Juvenile pityriasis rubra pilaris: report of 28 cases in Taiwan.

PubMed

Yang, Chao-Chun; Shih, I-Hsin; Lin, Wan-Lung; Yu, Yi-Sheng; Chiu, Hsien-Ching; Huang, Po-Han; Cheng, Yu-Wen; Lee, Julia Yu-Yun; Chen, WenChieh

2008-12-01

Pityriasis rubra pilaris (PRP) is a papulosquamous dermatosis uncommon in juveniles. Large-scale studies are limited, especially from Asian countries. We sought to analyze the clinical manifestations of juvenile PRP in Taiwanese patients and compare them with reported series in the literature. The diagnosis of juvenile PRP was made based on clinical-histopathologic correlation. The therapeutic response and disease course were followed up by re-examination of the patients or by telephone. A total of 47 patients were identified, with histopathologic confirmation of the clinical diagnosis of juvenile PRP in 28 cases. A preponderance of Griffiths' type IV PRP (85.7%) rather than type III PRP (14.3%) was found. Palmoplantar hyperkeratosis appeared to be a cardinal feature. In patients with type IV PRP, skin lesions in areas other than the elbows/knees and palms/soles were common. Treatment with systemic acitretin in 6 patients failed to effect a dose- or time-dependent improvement. In contrast with other studies, two thirds of our patients with type III and IV juvenile PRP had a protracted course lasting more than 3 years. This study was a retrospective review. Patient compliance with treatment was frequently poor. Type IV juvenile PRP predominated but our cases showed a wider distribution of skin lesions than is typically described. When children present with an acute onset of diffuse palmoplantar hyperkeratosis, a diagnosis of juvenile PRP should be considered. Because of the divergent clinical manifestations of juvenile PRP in different populations, there is a need to modify and re-evaluate classification systems based on regional differences.

Molecular dissection of step 2 catalysis of yeast pre-mRNA splicing investigated in a purified system

PubMed Central

Ohrt, Thomas; Odenwälder, Peter; Dannenberg, Julia; Prior, Mira; Warkocki, Zbigniew; Schmitzová, Jana; Karaduman, Ramazan; Gregor, Ingo; Enderlein, Jörg; Fabrizio, Patrizia; Lührmann, Reinhard

2013-01-01

Step 2 catalysis of pre-mRNA splicing entails the excision of the intron and ligation of the 5′ and 3′ exons. The tasks of the splicing factors Prp16, Slu7, Prp18, and Prp22 in the formation of the step 2 active site of the spliceosome and in exon ligation, and the timing of their recruitment, remain poorly understood. Using a purified yeast in vitro splicing system, we show that only the DEAH-box ATPase Prp16 is required for formation of a functional step 2 active site and for exon ligation. Efficient docking of the 3′ splice site (3′SS) to the active site requires only Slu7/Prp18 but not Prp22. Spliceosome remodeling by Prp16 appears to be subtle as only the step 1 factor Cwc25 is dissociated prior to step 2 catalysis, with its release dependent on docking of the 3′SS to the active site and Prp16 action. We show by fluorescence cross-correlation spectroscopy that Slu7/Prp18 and Prp16 bind early to distinct, low-affinity binding sites on the step-1-activated B* spliceosome, which are subsequently converted into high-affinity sites. Our results shed new light on the factor requirements for step 2 catalysis and the dynamics of step 1 and 2 factors during the catalytic steps of splicing. PMID:23685439

The use of autologous platelet-rich plasma in the orthopedic setting.

PubMed

Cohn, Claudia S; Lockhart, Evelyn; McCullough, J Jeffrey

2015-07-01

Autologous platelet-rich plasma (aPRP) is widely used with orthopedic patients to help treat injuries to tendons, cartilage, ligaments, and muscle. A comprehensive review of the literature was conducted to evaluate aPRP's efficacy and compare available methods. In addition, the production and administration of aPRP were explored. A literature search was performed. Randomized controlled clinical trials (RCTs) in orthopedic procedures on adult patients were included and assessed for methodologic quality. The main outcomes were pain relief, increase in function, structural integrity, and "healing" based on various validated scales. Twelve RCTs and one controlled cohort were included (four lateral epicondylitis, two chronic Achilles tendinopathy, two anterior cruciate ligament injury, and five rotator cuff injuries). Four trials reported some benefit from aPRP versus controls while eight trials found no benefit from aPRP applications versus control. One study had too many patients withdraw from the control arm for acceptable data interpretation. All protocols used a different aPRP formulation or method of delivery or application. Despite its popularity, there are no standardized criteria that define aPRP. Different techniques yield wide variability in terms of platelet count and concentration. These variations make it difficult to compare clinical trials that use aPRP or draw conclusions concerning its clinical efficacy in orthopedic procedures. Blood bankers have experience in the production of standardized blood components. This expertise may be used to develop and implement protocols for the production and administration of aPRP, as well as quality control measures. © 2015 AABB.

Utilization of Platelet-Rich Plasma for Musculoskeletal Injuries

PubMed Central

Zhang, Joanne Y.; Fabricant, Peter D.; Ishmael, Chad R.; Wang, Jeffrey C.; Petrigliano, Frank A.; Jones, Kristofer J.

2016-01-01

Background: Platelet-rich plasma (PRP) has emerged as a popular biologic treatment for musculoskeletal injuries and conditions. Despite numerous investigations on the efficacy of PRP therapy, current utilization of this treatment within the United States is not widely known. Purpose: To investigate the national utilization of PRP, including the incidence and conditions for which it is used in the clinical setting, and to determine the current charges associated with this treatment. Study Design: Descriptive epidemiology study. Methods: Using a national database (PearlDiver) of private insurance billing records, we conducted a comprehensive search using Current Procedural Terminology (CPT) codes to identify patients who received PRP injections over a 2-year period (2010-2011). Associated International Classification of Diseases, 9th Revision (ICD-9) codes were identified to determine the specific conditions the injection was used to treat. The aggregate patient data were analyzed by yearly quarter, practice setting, geographic region, and demographics. PRP therapy charges were calculated and reported as per-patient average charges (PPACs). Results: A total of 2571 patients who received PRP injections were identified; 51% were male and 75% were older than 35 years. The overall incidence ranged from 5.9 to 7.9 per 1000 patients over the study period. PRP was most commonly administered in hospitals (39%) and ambulatory surgical centers (37%) compared with in private offices (26%). The most common conditions treated were knee meniscus/plica disorders, followed by unspecified shoulder conditions, rotator cuff injuries, epicondylitis, and plantar fasciitis. Further evaluation revealed that 25% of all patients received injections for cartilage-related conditions, 25% meniscus, 25% unspecified, 12% tendon, 8% glenoid labrum, and 5% ligament. The PPAC for PRP treatment was US$1755 per injection. Conclusion: Despite a lack of consensus regarding PRP indications and efficacy, we observed widespread application of this treatment for a myriad of musculoskeletal injuries. Most treated patients were older than 35 years, and the most commonly treated conditions included cartilage and meniscus disorders. Given the current controversy surrounding this treatment, further studies are necessary to guide clinicians on the value of this therapy for each clinical diagnosis. PMID:28210648

Utilization of Platelet-Rich Plasma for Musculoskeletal Injuries: An Analysis of Current Treatment Trends in the United States.

PubMed

Zhang, Joanne Y; Fabricant, Peter D; Ishmael, Chad R; Wang, Jeffrey C; Petrigliano, Frank A; Jones, Kristofer J

2016-12-01

Platelet-rich plasma (PRP) has emerged as a popular biologic treatment for musculoskeletal injuries and conditions. Despite numerous investigations on the efficacy of PRP therapy, current utilization of this treatment within the United States is not widely known. To investigate the national utilization of PRP, including the incidence and conditions for which it is used in the clinical setting, and to determine the current charges associated with this treatment. Descriptive epidemiology study. Using a national database (PearlDiver) of private insurance billing records, we conducted a comprehensive search using Current Procedural Terminology (CPT) codes to identify patients who received PRP injections over a 2-year period (2010-2011). Associated International Classification of Diseases, 9th Revision (ICD-9) codes were identified to determine the specific conditions the injection was used to treat. The aggregate patient data were analyzed by yearly quarter, practice setting, geographic region, and demographics. PRP therapy charges were calculated and reported as per-patient average charges (PPACs). A total of 2571 patients who received PRP injections were identified; 51% were male and 75% were older than 35 years. The overall incidence ranged from 5.9 to 7.9 per 1000 patients over the study period. PRP was most commonly administered in hospitals (39%) and ambulatory surgical centers (37%) compared with in private offices (26%). The most common conditions treated were knee meniscus/plica disorders, followed by unspecified shoulder conditions, rotator cuff injuries, epicondylitis, and plantar fasciitis. Further evaluation revealed that 25% of all patients received injections for cartilage-related conditions, 25% meniscus, 25% unspecified, 12% tendon, 8% glenoid labrum, and 5% ligament. The PPAC for PRP treatment was US$1755 per injection. Despite a lack of consensus regarding PRP indications and efficacy, we observed widespread application of this treatment for a myriad of musculoskeletal injuries. Most treated patients were older than 35 years, and the most commonly treated conditions included cartilage and meniscus disorders. Given the current controversy surrounding this treatment, further studies are necessary to guide clinicians on the value of this therapy for each clinical diagnosis.

Substrate-assisted mechanism of RNP disruption by the spliceosomal Brr2 RNA helicase

PubMed Central

Theuser, Matthias; Höbartner, Claudia; Wahl, Markus C.; Santos, Karine F.

2016-01-01

The Brr2 RNA helicase disrupts the U4/U6 di-small nuclear RNA–protein complex (di-snRNP) during spliceosome activation via ATP-driven translocation on the U4 snRNA strand. However, it is unclear how bound proteins influence U4/U6 unwinding, which regions of the U4/U6 duplex the helicase actively unwinds, and whether U4/U6 components are released as individual molecules or as subcomplexes. Here, we set up a recombinant Brr2-mediated U4/U6 di-snRNP disruption system, showing that sequential addition of the U4/U6 proteins small nuclear ribonucleoprotein-associated protein 1 (Snu13), pre-mRNA processing factor 31 (Prp31), and Prp3 to U4/U6 di-snRNA leads to a stepwise decrease of Brr2-mediated U4/U6 unwinding, but that unwinding is largely restored by a Brr2 cofactor, the C-terminal Jab1/MPN domain of the Prp8 protein. Brr2-mediated U4/U6 unwinding was strongly inhibited by mutations in U4/U6 di-snRNAs that diminish the ability of U6 snRNA to adopt an alternative conformation but leave the number and kind of U4/U6 base pairs unchanged. Irrespective of the presence of the cofactor, the helicase segregated a Prp3-Prp31-Snu13-U4/U6 RNP into an intact Prp31-Snu13-U4 snRNA particle, free Prp3, and free U6 snRNA. Together, these observations suggest that Brr2 translocates only a limited distance on the U4 snRNA strand and does not actively release RNA-bound proteins. Unwinding is then completed by the partially displaced U6 snRNA adopting an alternative conformation, which leads to dismantling of the Prp3-binding site on U4/U6 di-snRNA but leaves the Prp31- and Snu13-binding sites on U4 snRNA unaffected. In this fashion, Brr2 can activate the spliceosome by stripping U6 snRNA of all precatalytic binding partners, while minimizing logistic requirements for U4/U6 di-snRNP reassembly after splicing. PMID:27354531

Normal platelet function in platelet concentrates requires non-platelet cells: a comparative in vitro evaluation of leucocyte-rich (type 1a) and leucocyte-poor (type 3b) platelet concentrates

PubMed Central

Parrish, William R; Roides, Breana; Hwang, Julia; Mafilios, Michael; Story, Brooks; Bhattacharyya, Samir

2016-01-01

Background Therapeutic success of platelet-rich plasma (PRP) may vary based on the composition and preparation method. The objective of this study was to evaluate the cellular components of platelet concentrates produced by a leucocyte-rich (LR-PRP) and a leucocyte-poor PRP systems (LP-PRP). Methods Parameters evaluated included platelet recovery, platelet concentration, red blood cell (RBC) and white blood cell (WBC) composition, platelet growth factor release and stimulation of human tendon cell proliferation in vitro. Results Platelet recoveries were 52% for LP-PRP and 89% for LR-PRP. LR-PRP demonstrated greater reproducibility with a 4.2% coefficient of variation (CV) compared with 19.4% for LP-PRP (p<0.001). LR-PRP demonstrated a greater increase in platelet concentration (7.9-fold) than LP-PRP (2.2-fold; p<0.001). LP-PRP showed 5.0-fold reductions in WBCs, while LR-PRP showed a 4.0-fold increase (p<0.001). LP-PRP reduced RBCs to a haematocrit of 0.25, while LR-PRP reduced haematocrit to 11.8. LP-PRP did not coagulate robustly on reactivation with CaCl2, and released significantly lower levels of epidermal growth factor (EGF) and transforming growth factor β1 (TGF-β1) than whole blood (p<0.03). LP-PRP also did not stimulate tendon cell proliferation greater than whole blood. In contrast, LR-PRP showed increases in each growth factor on activation with CaCl2 (p<0.01) and stimulated greater proliferation (p<0.05) compared with whole blood. Forced activation of LP-PRP with exogenous thrombin rescued the coagulation deficiency and induced greater growth factor release than comparable whole blood (p<0.03). Conclusions These data suggest that non-platelet cellular components in platelet concentrates are important for proper platelet function, including thrombin generation, growth factor release and clot retraction. PMID:27900155

Normal platelet function in platelet concentrates requires non-platelet cells: a comparative in vitro evaluation of leucocyte-rich (type 1a) and leucocyte-poor (type 3b) platelet concentrates.

PubMed

Parrish, William R; Roides, Breana; Hwang, Julia; Mafilios, Michael; Story, Brooks; Bhattacharyya, Samir

2016-01-01

Therapeutic success of platelet-rich plasma (PRP) may vary based on the composition and preparation method. The objective of this study was to evaluate the cellular components of platelet concentrates produced by a leucocyte-rich (LR-PRP) and a leucocyte-poor PRP systems (LP-PRP). Parameters evaluated included platelet recovery, platelet concentration, red blood cell (RBC) and white blood cell (WBC) composition, platelet growth factor release and stimulation of human tendon cell proliferation in vitro. Platelet recoveries were 52% for LP-PRP and 89% for LR-PRP. LR-PRP demonstrated greater reproducibility with a 4.2% coefficient of variation (CV) compared with 19.4% for LP-PRP (p<0.001). LR-PRP demonstrated a greater increase in platelet concentration (7.9-fold) than LP-PRP (2.2-fold; p<0.001). LP-PRP showed 5.0-fold reductions in WBCs, while LR-PRP showed a 4.0-fold increase (p<0.001). LP-PRP reduced RBCs to a haematocrit of 0.25, while LR-PRP reduced haematocrit to 11.8. LP-PRP did not coagulate robustly on reactivation with CaCl 2 , and released significantly lower levels of epidermal growth factor (EGF) and transforming growth factor β1 (TGF-β1) than whole blood (p<0.03). LP-PRP also did not stimulate tendon cell proliferation greater than whole blood. In contrast, LR-PRP showed increases in each growth factor on activation with CaCl 2 (p<0.01) and stimulated greater proliferation (p<0.05) compared with whole blood. Forced activation of LP-PRP with exogenous thrombin rescued the coagulation deficiency and induced greater growth factor release than comparable whole blood (p<0.03). These data suggest that non-platelet cellular components in platelet concentrates are important for proper platelet function, including thrombin generation, growth factor release and clot retraction.

Platelet collection efficiencies of three different platelet-rich plasma preparation systems.

PubMed

Aydin, Fatma; Pancar Yuksel, Esra; Albayrak, Davut

2015-06-01

Different systems have been used for the preparation of platelet-rich plasma (PRP), but platelet collection efficiencies of these systems are not clear. To evaluate the platelet collection efficiencies of three different PRP preparation systems. Blood samples were obtained from the same 16 volunteers for each system. The samples were centrifuged and PRP was prepared by three systems. The ratio of the total number of platelets in PRP to the total number of platelets of the venous blood sample of the patient expressed in percentage was named as platelet collection efficiency and calculated for each system. Mean platelet collection efficiencies were 66.6 (min: 56.9, max: 76.9), 58.3 (min: 27.3, max: 102.8), 50.8 (min: 27.2, max: 73) for top and bottom bag system, system using citrated tube, and the system using tube with Ficoll and cell extraction kit, respectively. Statistically significant difference was found only between the platelet collection efficiencies of systems using the tube with ficoll and cell extraction kit and the top and bottom bag system (p = 0.002). All three systems could be used for PRP preparation, but top and bottom bag system offers a slight advantage over the system using Ficoll and cell extraction kit regarding the platelet collection efficiency.

Prion potency in stem cells biology.

PubMed

Lopes, Marilene H; Santos, Tiago G

2012-01-01

Prion protein (PrP) can be considered a pivotal molecule because it interacts with several partners to perform a diverse range of critical biological functions that might differ in embryonic and adult cells. In recent years, there have been major advances in elucidating the putative role of PrP in the basic biology of stem cells in many different systems. Here, we review the evidence indicating that PrP is a key molecule involved in driving different aspects of the potency of embryonic and tissue-specific stem cells in self-perpetuation and differentiation in many cell types. It has been shown that PrP is involved in stem cell self-renewal, controlling pluripotency gene expression, proliferation, and neural and cardiomyocyte differentiation. PrP also has essential roles in distinct processes that regulate tissue-specific stem cell biology in nervous and hematopoietic systems and during muscle regeneration. Results from our own investigations have shown that PrP is able to modulate self-renewal and proliferation in neural stem cells, processes that are enhanced by PrP interactions with stress inducible protein 1 (STI1). Thus, the available data reveal the influence of PrP in acting upon the maintenance of pluripotent status or the differentiation of stem cells from the early embryogenesis through adulthood.

Isolation and Characterization of a Novel Pathogenesis-Related Protein Gene (GmPRP) with Induced Expression in Soybean (Glycine max) during Infection with Phytophthora sojae

PubMed Central

Jiang, Liangyu; Wu, Junjiang; Fan, Sujie; Li, Wenbin; Dong, Lidong; Cheng, Qun; Xu, Pengfei; Zhang, Shuzhen

2015-01-01

Pathogenesis-related proteins (PR proteins) play crucial roles in the plant defense system. A novel PRP gene was isolated from highly resistant soybean infected with Phytophthora sojae (P. sojae) and was named GmPRP (GenBank accession number: KM506762). The amino acid sequences of GmPRP showed identities of 74%, 73%, 72% and 69% with PRP proteins from Vitis vinifera, Populus trichocarpa, Citrus sinensis and Theobroma cacao, respectively. Quantitative real-time reverse transcription PCR (qRT-PCR) data showed that the expression of GmPRP was highest in roots, followed by the stems and leaves. GmPRP expression was upregulated in soybean leaves infected with P. sojae. Similarly, GmPRP expression also responded to defense/stress signaling molecules, including salicylic acid (SA), ethylene (ET), abscisic acid (ABA) and jasmonic acid (JA). GmPRP was localized in the cell plasma membrane and cytoplasm. Recombinant GmPRP protein exhibited ribonuclease activity and significant inhibition of hyphal growth of P. sojae 1 in vitro. Overexpression of the GmPRP gene in T2 transgenic tobacco and T2 soybean plants resulted in enhanced resistance to Phytophthora nicotianae (P. nicotianae) and P. sojae race 1, respectively. These results indicated that the GmPRP protein played an important role in the defense of soybean against P. sojae infection. PMID:26114301

The Properties of 3 Different Plasma Formulations and Their Effects on Tendinopathic Cells.

PubMed

Rubio-Azpeitia, Eva; Bilbao, Ane M; Sánchez, Pello; Delgado, Diego; Andia, Isabel

2016-08-01

Tendinopathies are attributed to failure of the healing process and inadequate tissue remodeling. Plasma injections can trigger regenerative responses by modifying the molecular microenvironment. To examine the differences in the mitotic, chemotactic, anabolic, and inflammatory effects between leukocyte- and platelet-rich plasma (L-PRP), platelet-rich plasma (PRP), and platelet-poor plasma (PPP). Controlled laboratory study. Tendinopathic cells were cultured in 3-dimensional (3D) hydrogels formed using PPP, PRP, and L-PRP. Cell migration was evaluated using a μ-Slide chemotaxis chamber with video microscopy. Proliferation was assessed using XTT assays. Expression of genes associated with matrix turnover, including type 1 collagen (COL1A1), COL3A1, aggrecan, decorin, fibronectin, matrix metalloproteinase 1 (MMP-1), MMP-3, A Disintegrin-Like And Metalloprotease With Thrombospondin Type 1 Motif proteins 4 (ADAMTS-4), and ADAMTS-5, was assessed using real-time reverse-transcription polymerase chain reaction. Secreted inflammatory proteins, including interleukin (IL)-1β, IL-6, IL-8, monocyte chemotactic protein 1 (MCP-1), and regulated on activation, normal T cell expressed and secreted (RANTES), as well as vascular endothelial growth factor (VEGF) and connective tissue growth factor (CTGF), were quantified using enzyme-linked immunosorbent assay. Tendinopathic cells migrate at a higher velocity along L-PRP and PRP than along PPP gradients. PRP and L-PRP promote hypercellularity. PPP and PRP showed more pronounced anabolic properties, as demonstrated by enhanced COL1A1 and COL3A1 and reduced MMP-1 expression. Decorin, fibronectin, and aggrecan were downregulated in L-PRP compared with PPP and PRP. L-PRP and PRP were shown to be more proinflammatory than PPP in terms of IL-6 secretion, but cells in PPP showed MCP-1(high) phenotype. CTGF secretion was significantly reduced in L-PRP compared with PPP and PRP. The main advantages of L-PRP and PRP use, compared with PPP, include their stronger chemotactic and proliferative properties. While PPP and PRP stimulate matrix anabolism, L-PRP is more proinflammatory. Emphasis should be placed on the temporal needs and biological characteristics of injured tendons, and plasma formulations need to be tailored accordingly. Versatile systems allowing the preparation of different plasma formulations, such as PPP, PRP, or L-PRP, can help refine clinical applications by taking advantage of their different biological properties. © 2016 The Author(s).

An endogenous reference gene of common and durum wheat for detection of genetically modified wheat.

PubMed

Imai, Shinjiro; Tanaka, Keiko; Nishitsuji, Yasuyuki; Kikuchi, Yosuke; Matsuoka, Yasuyuki; Arami, Shin-Ichiro; Sato, Megumi; Haraguchi, Hiroyuki; Kurimoto, Youichi; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi

2012-01-01

To develop a method for detecting GM wheat that may be marketed in the near future, we evaluated the proline-rich protein (PRP) gene as an endogenous reference gene of common wheat (Triticum aestivum L.) and durum wheat (Triticum durum L.). Real-time PCR analysis showed that only DNA of wheat was amplified and no amplification product was observed for phylogenetically related cereals, indicating that the PRP detection system is specific to wheat. The intensities of the amplification products and Ct values among all wheat samples used in this study were very similar, with no nonspecific or additional amplification, indicating that the PRP detection system has high sequence stability. The limit of detection was estimated at 5 haploid genome copies. The PRP region was demonstrated to be present as a single or double copy in the common wheat haploid genome. Furthermore, the PRP detection system showed a highly linear relationship between Ct values and the amount of plasmid DNA, indicating that an appropriate calibration curve could be constructed for quantitative detection of GM wheat. All these results indicate that the PRP gene is a suitable endogenous reference gene for PCR-based detection of GM wheat.

Quantitating PrP polymorphisms present in prions from heterozygous scrapie-infected sheep

USDA-ARS?s Scientific Manuscript database

Scrapie is a prion (PrPSc) disease of sheep. The incubation period of sheep scrapie is strongly influenced by polymorphisms at positions 136, 154, and 171 of a sheep’s normal cellular prion protein (PrPC). Chymotrypsin was used to digest sheep recombinant PrP to identify a set of characteristic pept...

Platelet-Rich Plasma Therapy for Knee Joint Problems: Review of the Literature, Current Practice and Legal Perspectives in Korea

PubMed Central

Park, Yong-Geun; Han, Seung Beom; Song, Sang Jun; Kim, Tae Jin

2012-01-01

Platelet-rich plasma (PRP) is a concentrate extract of platelets from autologous blood, and represents a possible treatment option for the stimulation and acceleration of soft-tissue healing and regeneration in orthopedics. Currently, the availability of devices for outpatient preparation and delivery contributes to the increase in the clinical use of PRP therapy in practical setting of orthopedic fields. However, there is still paucity of scientific evidence in the literature to prove efficacy of PRP therapy for the treatment of ligament or tendon problems around the knee joint. Moreover, strong evidence from well-designed clinical trials to support the PRP therapy for osteoarthritis of the knee joint is yet scanty in the literature. Scientific studies need to be performed to assess clinical indications, efficacy, and safety of PRP, and this will require high powered randomized controlled trials. Nonetheless, some hospitals exaggeratedly advertise PRP procedures as the ultimate treatment and a novel technology with abundant scientific evidence for the treatment of knee problems. As a matter of fact, PRP protocols are currently approved only for use in clinical trials and research, and are not allowed for treatment purpose by any institutions in Korea. At present, clinical use of PRP therapy for ligament or tendon problems or osteoarthritis of knee joint is defined as illegal medical practice, regardless of whether it is performed as a sole procedure or as a part of prolotherapy, because the safety and validity are not yet approved by the Ministry of Health and Welfare and Health Insurance Review and Assessment Service. Practicing physicians should remember that injection of PRP to patients by imposing medical charge is still illegal as per the current medical law in Korea. PMID:22708106

PARot--assessing platelet-rich plasma plus arthroscopic subacromial decompression in the treatment of rotator cuff tendinopathy: study protocol for a randomized controlled trial.

PubMed

Carr, Andrew; Cooper, Cushla; Murphy, Richard; Watkins, Bridget; Wheway, Kim; Rombach, Ines; Beard, David

2013-06-11

Platelet-rich plasma (PRP) is an autologous platelet concentrate. It is prepared by separating the platelet fraction of whole blood from patients and mixing it with an agent to activate the platelets. In a clinical setting, PRP may be reapplied to the patient to improve and hasten the healing of tissue. The therapeutic effect is based on the presence of growth factors stored in the platelets. Current evidence in orthopedics shows that PRP applications can be used to accelerate bone and soft tissue regeneration following tendon injuries and arthroplasty. Outcomes include decreased inflammation, reduced blood loss and post-treatment pain relief. Recent shoulder research indicates there is poor vascularization present in the area around tendinopathies and this possibly prevents full healing capacity post surgery (Am J Sports Med36(6):1171-1178, 2008). Although it is becoming popular in other areas of orthopedics there is little evidence regarding the use of PRP for shoulder pathologies. The application of PRP may help to revascularize the area and consequently promote tendon healing. Such evidence highlights an opportunity to explore the efficacy of PRP use during arthroscopic shoulder surgery for rotator cuff pathologies. PARot is a single center, blinded superiority-type randomized controlled trial assessing the clinical outcomes of PRP applications in patients who undergo shoulder surgery for rotator cuff disease. Patients will be randomized to one of the following treatment groups: arthroscopic subacromial decompression surgery or arthroscopic subacromial decompression surgery with application of PRP. Current Controlled Trials: ISRCTN10464365.

In search of a consensus terminology in the field of platelet concentrates for surgical use: platelet-rich plasma (PRP), platelet-rich fibrin (PRF), fibrin gel polymerization and leukocytes.

PubMed

Dohan Ehrenfest, David M; Bielecki, Tomasz; Mishra, Allan; Borzini, Piero; Inchingolo, Francesco; Sammartino, Gilberto; Rasmusson, Lars; Everts, Peter A

2012-06-01

In the field of platelet concentrates for surgical use, most products are termed Platelet-Rich Plasma (PRP). Unfortunately, this term is very general and incomplete, leading to many confusions in the scientific database. In this article, a panel of experts discusses this issue and proposes an accurate and simple terminology system for platelet concentrates for surgical use. Four main categories of products can be easily defined, depending on their leukocyte content and fibrin architecture: Pure Platelet-Rich Plasma (P-PRP), such as cell separator PRP, Vivostat PRF or Anitua's PRGF; Leukocyteand Platelet-Rich Plasma (L-PRP), such as Curasan, Regen, Plateltex, SmartPReP, PCCS, Magellan, Angel or GPS PRP; Pure Plaletet-Rich Fibrin (P-PRF), such as Fibrinet; and Leukocyte- and Platelet-Rich Fibrin (L-PRF), such as Choukroun's PRF. P-PRP and L-PRP refer to the unactivated liquid form of these products, their activated versions being respectively named P-PRP gels and L-PRP gels. The purpose of this search for a terminology consensus is to plead for a more serious characterization of these products. Researchers have to be aware of the complex nature of these living biomaterials, in order to avoid misunderstandings and erroneous conclusions. Understanding the biomaterials or believing in the magic of growth factors ? From this choice depends the future of the field.

Platelet rich plasma for treatment of nonhealing diabetic foot ulcers: a case report.

PubMed

Mehrannia, Masoud; Vaezi, Mitra; Yousefshahi, Fardin; Rouhipour, Nahid

2014-02-01

Diabetic foot ulcers are one of the most important causes of lower limb amputations worldwide. The conventional treatments of diabetic foot ulcers are costly and often require patients to be hospitalized for long periods of time, thus representing a huge burden on any health care system. The use of autologous platelet-rich plasma (PRP), which is rich in multiple growth factors, may bear some similarities to the natural wound healing process. Nonetheless, few studies on human subjects have so far addressed the efficacy of PRP as a novel and minimally invasive treatment. Today, there is only 1 approved and available system to separate PRP from a patient's own blood in order to be used in diabetic ulcers. This system incorporates bovine thrombin for activation of PRP gel and may be applied by many healthcare providers without the need for extensive special training. In this report, a patient with extensive diabetic foot ulcers, non-responsive to other treatment modalities, was successfully treated by PRP. Copyright © 2014 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Bone marrow concentrate and platelet-rich plasma differ in cell distribution and interleukin 1 receptor antagonist protein concentration.

PubMed

Cassano, Jennifer M; Kennedy, John G; Ross, Keir A; Fraser, Ethan J; Goodale, Margaret B; Fortier, Lisa A

2018-01-01

Bone marrow concentrate (BMC) and platelet-rich plasma (PRP) are used extensively in regenerative medicine. The aim of this study was to determine differences in the cellular composition and cytokine concentrations of BMC and PRP and to compare two commercial BMC systems in the same patient cohort. Patients (29) undergoing orthopaedic surgery were enrolled. Bone marrow aspirate (BMA) was processed to generate BMC from two commercial systems (BMC-A and BMC-B). Blood was obtained to make PRP utilizing the same system as BMC-A. Bone marrow-derived samples were cultured to measure colony-forming units, and flow cytometry was performed to assess mesenchymal stem cell (MSC) markers. Cellular concentrations were assessed for all samples. Catabolic cytokines and growth factors important for cartilage repair were measured using multiplex ELISA. Colony-forming units were increased in both BMCs compared to BMA (p < 0.0001). Surface markers were consistent with MSCs. Platelet counts were not significantly different between BMC-A and PRP, but there were differences in leucocyte concentrations. TGF-β1 and PDGF were not different between BMC-A and PRP. IL-1ra concentrations were greater (p = 0.0018) in BMC-A samples (13,432 pg/mL) than in PRP (588 pg/mL). The IL-1ra/IL-1β ratio in all BMC samples was above the value reported to inhibit IL-1β. The bioactive factors examined in this study have differing clinical effects on musculoskeletal tissue. Differences in the cellular and cytokine composition between PRP and BMC and between BMC systems should be taken into consideration by the clinician when choosing a biologic for therapeutic application. Clinical, Level II.

Experience with the Pascal® photocoagulator: An analysis of over 1200 laser procedures with regard to parameter refinement

PubMed Central

Sheth, Saumil; Lanzetta, Paolo; Veritti, Daniele; Zucchiatti, Ilaria; Savorgnani, Carola; Bandello, Francesco

2011-01-01

Aim: To systematically refine and recommend parameter settings of spot size, power, and treatment duration using the Pascal® photocoagulator, a multi-spot, semi-automated, short-duration laser system. Materials and Methods: A retrospective consecutive series with 752 Caucasian eyes and 1242 laser procedures over two years were grouped into, (1) 374 macular focal / grid photocoagulation (FP), (2), 666 panretinal photocoagulation (PRP), and (3) 202 barrage photocoagulation (BP). Parameters for power, duration, spot number, and spot size were recorded for every group. Results: Power parameters for all groups showed a non-gaussian distribution; FP group, median 190 mW, range 100 – 950 mW, and PRP group, median 800 mW, range 100 – 2000 mW. On subgroup comparison, for similar spot size, as treatment duration decreased, the power required increased, albeit in a much lesser proportion than that given by energy = power × time. Most frequently used patterns were single spot (89% of cases) in FP, 5 × 5 box (72%) in PRP, and 2 × 2 box (78%) in BP. Spot diameters as high as ≈ 700 μm on retina were given in the PRP group. Single session PRP was attempted in six eyes with a median spot count of 3500. Conclusion: Overall, due to the small duration of its pulse, the Pascal® photocoagulator tends to use higher powers, although much lower cumulative energies, than those used in a conventional laser. The consequent lesser heat dissipation, especially lateral, can allow one to use relatively larger spot sizes and give more closely spaced burns, without incurring significant side effects. PMID:21350276

Does Intra-articular Platelet-Rich Plasma Injection Provide Clinically Superior Outcomes Compared With Other Therapies in the Treatment of Knee Osteoarthritis? A Systematic Review of Overlapping Meta-analyses.

PubMed

Campbell, Kirk A; Saltzman, Bryan M; Mascarenhas, Randy; Khair, M Michael; Verma, Nikhil N; Bach, Bernard R; Cole, Brian J

2015-11-01

The aims of this study were (1) to perform a systematic review of meta-analyses evaluating platelet-rich plasma (PRP) injection in the treatment of knee joint cartilage degenerative pathology, (2) to provide a framework for analysis and interpretation of the best available evidence to provide recommendations for use (or lack thereof) of PRP in the setting of knee osteoarthritis (OA), and (3) to identify literature gaps where continued investigation would be suggested. Literature searches were performed for meta-analyses examining use of PRP versus corticosteroids, hyaluronic acid, oral nonsteroidal anti-inflammatory drugs, or placebo. Clinical data were extracted, and meta-analysis quality was assessed. The Jadad algorithm was applied to determine meta-analyses that provided the highest level of evidence. Three meta-analyses met the eligibility criteria and ranged in quality from Level II to Level IV evidence. All studies compared outcomes of treatment with intra-articular platelet-rich plasma (IA-PRP) versus control (intra-articular hyaluronic acid or intra-articular placebo). Use of PRP led to significant improvements in patient outcomes at 6 months after injection, and these improvements were seen starting at 2 months and were maintained for up to 12 months. It is unclear if the use of multiple PRP injections, the double-spinning technique, or activating agents leads to better outcomes. Patients with less radiographic evidence of arthritis benefit more from PRP treatment. The use of multiple PRP injections may increase the risk of self-limited local adverse reactions. After application of the Jadad algorithm, 3 concordant high-quality meta-analyses were selected and all showed that IA-PRP provided clinically relevant improvements in pain and function compared with the control treatment. IA-PRP is a viable treatment for knee OA and has the potential to lead to symptomatic relief for up to 12 months. There appears to be an increased risk of local adverse reactions after multiple PRP injections. IA-PRP offers better symptomatic relief to patients with early knee degenerative changes, and its use should be considered in patients with knee OA. Level IV, systematic review of Level II through IV studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Effects of Platelet-Rich Plasma and Indomethacin on Biomechanics of Rotator Cuff Repair.

PubMed

Meadows, Molly C; Levy, David M; Ferry, Christopher M; Gardner, Thomas R; Teratani, Takeshi; Ahmad, Christopher S

We conducted a study to determine if platelet-rich plasma (PRP) enhances the strength of rotator cuff repair (RCR) and if concomitant use of nonsteroidal anti-inflammatory drugs (NSAIDs) affects PRP efficacy. We also wanted to determine the optimal centrifugation protocol for making PRP from rats. This study used 48 rats, 14 in a centrifugation protocol and 34 in an operative protocol. Six syngeneic rats from the operative group were used as PRP blood donors; the other 28 operative rats underwent bilateral RCRs. The Autologous Conditioned Plasma system (Arthrex) was used to prepare leukocyte-poor PRP. One shoulder was randomized to an intratendinous PRP injection, and the other received normal saline. Each rat was also randomly placed on a postoperative diet, either a regular diet or an indomethacin-enhanced diet. After rats were euthanized at 3 weeks, specimens were dissected to isolate the supraspinatus tendon at its humeral attachment, which was subjected to biomechanical testing. PRP prepared with a protocol of 5 minutes × 1300 revolutions per minute had the highest platelet index. Mean (SD) energy to failure was significantly higher (P = .03) in tendons treated with PRP, 11.7 (7.3) N-mm, than in tendons treated with saline, 8.7 (4.6) N-mm. Both groups (PRP, saline) showed no significant differences between tendons treated with NSAIDs and those not treated with NSAIDs. Intraoperative application of PRP enhances energy to failure after RCR in rats. There were no differences in biomechanical strength with NSAID use and no interactions between PRP and NSAID use.

Analysis of Platelet-Rich Plasma Extraction

PubMed Central

Fitzpatrick, Jane; Bulsara, Max K.; McCrory, Paul Robert; Richardson, Martin D.; Zheng, Ming Hao

2017-01-01

Background: Platelet-rich plasma (PRP) has been extensively used as a treatment in tissue healing in tendinopathy, muscle injury, and osteoarthritis. However, there is variation in methods of extraction, and this produces different types of PRP. Purpose: To determine the composition of PRP obtained from 4 commercial separation kits, which would allow assessment of current classification systems used in cross-study comparisons. Study Design: Controlled laboratory study. Methods: Three normal adults each donated 181 mL of whole blood, some of which served as a control and the remainder of which was processed through 4 PRP separation kits: GPS III (Biomet Biologics), Smart-Prep2 (Harvest Terumo), Magellan (Arteriocyte Medical Systems), and ACP (Device Technologies). The resultant PRP was tested for platelet count, red blood cell count, and white blood cell count, including differential in a commercial pathology laboratory. Glucose and pH measurements were obtained from a blood gas autoanalyzer machine. Results: Three kits taking samples from the “buffy coat layer” were found to have greater concentrations of platelets (3-6 times baseline), while 1 kit taking samples from plasma was found to have platelet concentrations of only 1.5 times baseline. The same 3 kits produced an increased concentration of white blood cells (3-6 times baseline); these consisted of neutrophils, leukocytes, and monocytes. This represents high concentrations of platelets and white blood cells. A small drop in pH was thought to relate to the citrate used in the sample preparation. Interestingly, an unexpected increase in glucose concentrations, with 3 to 6 times greater than baseline levels, was found in all samples. Conclusion: This study reveals the variation of blood components, including platelets, red blood cells, leukocytes, pH, and glucose in PRP extractions. The high concentrations of cells are important, as the white blood cell count in PRP samples has frequently been ignored, being considered insignificant. The lack of standardization of PRP preparation for clinical use has contributed at least in part to the varying clinical efficacy in PRP use. Clinical Relevance: The variation of platelet and other blood component concentrations between commercial PRP kits may affect clinical treatment outcomes. There is a need for standardization of PRP for clinical use. PMID:28210651

Therapeutic Effect of Platelet-Rich Plasma in Rat Spinal Cord Injuries

PubMed Central

Chen, Nan-Fu; Sung, Chun-Sung; Wen, Zhi-Hong; Chen, Chun-Hong; Feng, Chien-Wei; Hung, Han-Chun; Yang, San-Nan; Tsui, Kuan-Hao; Chen, Wu-Fu

2018-01-01

Platelet-rich plasma (PRP) is prepared by centrifuging fresh blood in an anticoagulant state, and harvesting the platelet-rich portion or condensing platelets. Studies have consistently demonstrated that PRP concentrates are an abundant source of growth factors, such as platelet-derived growth factor (PDGF), transforming growth factor β (TGF-β), insulin-like growth factor 1 (IGF-1), and epithelial growth factor (EGF). The complex mechanisms underlying spinal cord injury (SCI) diminish intrinsic repair and neuronal regeneration. Several studies have suggested that growth factor-promoted axonal regeneration can occur for an extended period after injury. More importantly, the delivery of exogenous growth factors contained in PRP, such as EGF, IGF-1, and TGF-β, has neurotrophic effects on central nervous system (CNS) injuries and neurodegenerative diseases. However, only a few studies have investigated the effects of PRP on CNS injuries or neurodegenerative diseases. According to our review of relevant literature, no study has investigated the effect of intrathecal (i.t.) PRP injection into the injured spinal cord and activation of intrinsic mechanisms. In the present study, we directly injected i.t. PRP into rat spinal cords and examined the effects of PRP on normal and injured spinal cords. In rats with normal spinal cords, PRP induced microglia and astrocyte activation and PDGF-B and ICAM-1 expression. In rats with SCIs, i.t. PRP enhanced the locomotor recovery and spared white matter, promoted angiogenesis and neuronal regeneration, and modulated blood vessel size. Furthermore, a sustained treatment (a bolus of PRP followed by a 1/3 dose of initial PRP concentration) exerted more favorable therapeutic effects than a single dose of PRP. Our findings suggest by i.t. PRP stimulate angiogenesis, enhancing neuronal regeneration after SCI in rats. Although PRP induces minor inflammation in normal and injured spinal cords, it has many advantages. It is an autologous, biocompatible, nontoxic material that does not result in a major immune response. In addition, based on its safety and ease of preparation, we hypothesize that PRP is a promising therapeutic agent for SCI. PMID:29740270

Does platelet-rich plasma accelerate recovery after rotator cuff repair? A prospective cohort study.

PubMed

Jo, Chris Hyunchul; Kim, Ji Eun; Yoon, Kang Sup; Lee, Ji Ho; Kang, Seung Baik; Lee, Jae Hyup; Han, Hyuk Soo; Rhee, Seung Hwan; Shin, Sue

2011-10-01

Platelet-rich plasma (PRP) has been recently used to enhance and accelerate the healing of musculoskeletal injuries and diseases, but evidence is still lacking, especially on its effects after rotator cuff repair. Platelet-rich plasma accelerates recovery after arthroscopic rotator cuff repair in pain relief, functional outcome, overall satisfaction, and enhanced structural integrity of repaired tendon. Cohort study; Level of evidence, 2. Forty-two patients with full-thickness rotator cuff tears were included. Patients were informed about the use of PRP before surgery and decided themselves whether to have PRP placed at the time of surgery. Nineteen patients underwent arthroscopic rotator cuff repair with PRP and 23 without. Platelet-rich plasma was prepared via plateletpheresis and applied in the form of a gel threaded to a suture and placed at the interface between tendon and bone. Outcomes were assessed preoperatively and at 3, 6, 12, and finally at a minimum of 16 months after surgery (at an average of 19.7 ± 1.9 months) with respect to pain, range of motion, strength, and overall satisfaction, and with respect to functional scores as determined using the following scoring systems: the American Shoulder and Elbow Surgeon (ASES) system, the Constant system, the University of California at Los Angeles (UCLA) system, the Disabilities of the Arm, Shoulder and Hand (DASH) system, the Simple Shoulder Test (SST) system, and the Shoulder Pain and Disability Index (SPADI) system. At a minimum of 9 months after surgery, repaired tendon structural integrities were assessed by magnetic resonance imaging. Platelet-rich plasma gel application to arthroscopic rotator cuff repairs did not accelerate recovery with respect to pain, range of motion, strength, functional scores, or overall satisfaction as compared with conventional repair at any time point. Whereas magnetic resonance imaging demonstrated a retear rate of 26.7% in the PRP group and 41.2% in the conventional group, there was no statistical significance between the groups (P = .388). The results suggest that PRP application during arthroscopic rotator cuff repair did not clearly demonstrate accelerated recovery clinically or anatomically except for an improvement in internal rotation. Nevertheless, as the study may have been underpowered to detect clinically important differences in the structural integrity, additional investigations, including the optimization of PRP preparation and a larger randomized study powered for healing rate, are necessary to further determine the effect of PRP.

Application of Platelet-Rich Plasma to Disorders of the Knee Joint

PubMed Central

Mandelbaum, Bert R.; McIlwraith, C. Wayne

2013-01-01

Importance. The promising therapeutic potential and regenerative properties of platelet-rich plasma (PRP) have rapidly led to its widespread clinical use in musculoskeletal injury and disease. Although the basic scientific rationale surrounding PRP products is compelling, the clinical application has outpaced the research. Objective. The purpose of this article is to examine the current concepts around the basic science of PRP application, different preparation systems, and clinical application of PRP in disorders in the knee. Evidence Acquisition. A systematic search of PubMed for studies that evaluated the basic science, preparation and clinical application of platelet concentrates was performed. The search used terms, including platelet-rich plasma or PRP preparation, activation, use in the knee, cartilage, ligament, and meniscus. Studies found in the initial search and related studies were reviewed. Results. A comprehensive review of the literature supports the potential use of PRP both nonoperatively and intraoperatively, but highlights the absence of large clinical studies and the lack of standardization between method, product, and clinical efficacy. Conclusions and Relevance. In addition to the call for more randomized, controlled clinical studies to assess the clinical effect of PRP, at this point, it is necessary to investigate PRP product composition and eventually have the ability to tailor the therapeutic product for specific indications. PMID:26069674

Portable Radiation Package (PRP) Instrument Handbook

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reynolds, R Michael

The Portable Radiation Package (PRP) was developed to provide basic radiation information in locations such as ships at sea where proper exposure is remote and difficult, the platform is in motion, and azimuth alignment is not fixed. Development of the PRP began at Brookhaven National Laboratory (BNL) in the mid-1990s and versions of it were deployed on ships in the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Nauru-99 project. The PRP was deployed on ships in support of the National Aeronautics and Space Administration (NASA) Sensor Intercomparison for Marine Biological and Interdisciplinary Ocean Studies (SIMBIOS)more » program. Over the years the measurements have remained the same while the post-processing data analysis, especially for the FRSR, has evolved. This document describes the next-generation Portable Radiation Package (PRP2) that was developed for the DOE ARM Facility, under contract no. 9F-31462 from Argonne National Laboratory (ANL). The PRP2 has the same scientific principles that were well validated in prior studies, but has upgraded electronic hardware. The PRP2 approach is completely modular, both in hardware and software. Each sensor input is treated as a separate serial stream into the data collection computer. In this way the operator has complete access to each component of the system for purposes of error checking, calibration, and maintenance. The resulting system is more reliable, easier to install in complex situations, and more amenable to upgrade.« less

Does the Use of Platelet-Rich Plasma at the Time of Surgery Improve Clinical Outcomes in Arthroscopic Rotator Cuff Repair When Compared With Control Cohorts? A Systematic Review of Meta-analyses.

PubMed

Saltzman, Bryan M; Jain, Akshay; Campbell, Kirk A; Mascarenhas, Randy; Romeo, Anthony A; Verma, Nikhil N; Cole, Brian J

2016-05-01

The aims of the study were as follows: (1) to perform a systematic review of meta-analyses evaluating platelet-rich plasma (PRP) use at the time of arthroscopic rotator cuff repair surgery and to determine its effect on retear rates and clinical outcomes; (2) to provide a framework for the analysis and interpretation of the best currently available evidence; and (3) to identify gaps within the literature where suggestions for continued investigational efforts would be valid. Literature searches were performed to identify meta-analyses examining arthroscopic rotator cuff repairs augmented with PRP versus control (no PRP). Clinical data were extracted and meta-analysis quality was assessed using the Quality of Reporting of Meta-analyses and Oxman-Guyatt scales. Seven meta-analyses met inclusion and exclusion criteria. All were considered as being of similar quality with Quality of Reporting of Meta-analyses scores >15 and Oxman scores of 7. A total of 3,193 overlapping patients treated were included with mean follow-up from 12 to 31 months. When compared with control patients, use of PRP at the time of rotator cuff repair did not result in significantly lower overall retear rates or improved clinical outcome scores. The following postoperative functional scores comparing PRP versus control were reported: Constant (no significant difference demonstrated with PRP use in 5 of 6 reporting meta-analyses), University of California - Los Angeles (no difference, 6 of 6), American Shoulder and Elbow Society (no difference, 4 of 4), and Simple Shoulder Test (no difference, 3 of 5). Subgroup analysis performed by 3 meta-analyses showed evidence of improved outcomes with solid PRP matrix versus liquid, small- and/or medium-sized versus large and/or massive tears, PRP application at the tendon-bone interface versus over tendon, and in the setting of double-row versus single-row rotator cuff. The current highest level of evidence suggests that PRP use at the time of arthroscopic rotator cuff repair does not universally improve retear rates or affect clinical outcome scores. However, the effects of PRP use on retear rates trend toward beneficial outcomes if evaluated in the context of the following specific variables: use of a solid PRP matrix; application of PRP at the tendon-bone interface; in double-row repairs; and with small- and/or medium-sized rotator cuff tears. Level III, systematic review of Level II and III studies. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Interactive videogame as rehabilitation tool of patients with chronic respiratory diseases: preliminary results of a feasibility study.

PubMed

Mazzoleni, Stefano; Montagnani, Giulia; Vagheggini, Guido; Buono, Lorenzo; Moretti, Francesca; Dario, Paolo; Ambrosino, Nicolino

2014-10-01

To evaluate the effectiveness of an interactive videogame (IV) system in addition to a supervised pulmonary rehabilitation programme (PRP) in patients with chronic respiratory diseases. Randomised Controlled Trial comparing standard PRP (20 patients, control group: CG), and PRP + sessions of interactive videogame-aided exercises (20 patients, experimental group: EG). Lung and respiratory muscle function, arterial blood gases, exercise capacity, dyspnoea, health status and health-related quality of life (HRQL) and emotional response were measured before and after PRP. A questionnaire on acceptability of the PRP was administered. Exercise capacity, dyspnoea and HRQL significantly improved in both groups after the PRP, whereas the EG showed a greater improvement in six-minute walk test and transitional dyspnoea index than the CG. No difference in psychological status or acceptability of PRP was observed between the two groups. The addition of IV training was more effective for improving some parameters of exercise tolerance and dyspnoea, although did not result in better psychological status nor it was better accepted than the standard PRP in patients with chronic respiratory diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Molecular-level insights of early-stage prion protein aggregation on mica and gold surface determined by AFM imaging and molecular simulation.

PubMed

Lou, Zhichao; Wang, Bin; Guo, Cunlan; Wang, Kun; Zhang, Haiqian; Xu, Bingqian

2015-11-01

By in situ time-lapse AFM, we investigated early-stage aggregates of PrP formed at low concentration (100 ng/mL) on mica and Au(111) surfaces in acetate buffer (pH 4.5). Remarkably different PrP assemblies were observed. Oligomeric structures of PrP aggregates were observed on mica surface, which was in sharp contrast to the multi-layer PrP aggregates yielding parallel linear patterns observed Au(111) surface. Combining molecular dynamics and docking simulations, PrP monomers, dimers and trimers were revealed as the basic units of the observed aggregates. Besides, the mechanisms of the observed PrP aggregations and the corresponding molecular-substrate and intermolecular interactions were suggested. These interactions involved gold-sulfur interaction, electrostatic interaction, hydrophobic interaction, and hydrogen binding interaction. In contrast, the PrP aggregates observed in pH 7.2 PBS buffer demonstrated similar large ball-like structures on both mica and Au(111) surfaces. The results indicate that the pH of a solution and the surface of the system can have strong effects on supramolecular assemblies of prion proteins. This study provides in-depth understanding on the structural and mechanistic nature of PrP aggregation, and can be used to study the aggregation mechanisms of other proteins with similar misfolding properties. Copyright © 2015 Elsevier B.V. All rights reserved.

Alteration of microcirculation is a hallmark of very early systemic sclerosis patients: a laser speckle contrast analysis.

PubMed

Della Rossa, Alessandra; Cazzato, Massimiliano; d'Ascanio, Anna; Tavoni, Antonio; Bencivelli, Walter; Pepe, Pasquale; Mosca, Marta; Baldini, Chiara; Rossi, Marco; Bombardieri, Stefano

2013-01-01

To investigate blood flow and microvascular reactivity by laser speckle perfusion imager (Perimed, Jarfalla) in consecutive patients affected by Raynaud's phenomenon at baseline and following dynamic stimulations. Skin blood flow in the dorsum of the hand was measured at baseline and after cold test and post-occlusive hyperemia test in 56 consecutive subjects affected by Raynaud's phenomenon (RP), 20 primary (PRP) and 36 secondary to systemic sclerosis (SSc). Twenty healthy subjects (HS) were studied as controls. After cold test, SSc had a significant reduction of blood flow (-58%) as compared to HS (-19%) (p=0.01). Recovery time was significantly higher in SSc (58 minutes) as compared to HS (18 minutes) and PRP (19 minutes) (p=0.006 and 0.0016, respectively). Peak flow after ischaemic test was significantly reduced in SSc (+237%) as compared to PRP (+485%) (p=0.0068). Post-ischaemic hyperemic area under the curve (AUC) was blunted in SSc (79U/sec) compared to PRP (167 U/sec) (p=0.0126). Proximal distal gradient was noticed in 74% of HS, 45% of PRP and 36% of SSc (p=0.01). Homogeneous pattern of flux distribution was significantly different between HS (95%), PRP (80%), and SSc (16%) (p<0.0001). Among SSc patients, a significant difference in ischaemic challenge was shown between patients with early-SSc versus patients with definite-SSc. Our preliminary results indicate a clearcut alteration of the dynamic of microcirculation in SSc-RP as compared to PRP and HS. Among SSc patients, early-SSc is a separate entity as compared to established disease.

PARot – assessing platelet-rich plasma plus arthroscopic subacromial decompression in the treatment of rotator cuff tendinopathy: study protocol for a randomized controlled trial

PubMed Central

2013-01-01

Background Platelet-rich plasma (PRP) is an autologous platelet concentrate. It is prepared by separating the platelet fraction of whole blood from patients and mixing it with an agent to activate the platelets. In a clinical setting, PRP may be reapplied to the patient to improve and hasten the healing of tissue. The therapeutic effect is based on the presence of growth factors stored in the platelets. Current evidence in orthopedics shows that PRP applications can be used to accelerate bone and soft tissue regeneration following tendon injuries and arthroplasty. Outcomes include decreased inflammation, reduced blood loss and post-treatment pain relief. Recent shoulder research indicates there is poor vascularization present in the area around tendinopathies and this possibly prevents full healing capacity post surgery (Am J Sports Med36(6):1171–1178, 2008). Although it is becoming popular in other areas of orthopedics there is little evidence regarding the use of PRP for shoulder pathologies. The application of PRP may help to revascularize the area and consequently promote tendon healing. Such evidence highlights an opportunity to explore the efficacy of PRP use during arthroscopic shoulder surgery for rotator cuff pathologies. Methods/Design PARot is a single center, blinded superiority-type randomized controlled trial assessing the clinical outcomes of PRP applications in patients who undergo shoulder surgery for rotator cuff disease. Patients will be randomized to one of the following treatment groups: arthroscopic subacromial decompression surgery or arthroscopic subacromial decompression surgery with application of PRP. The study will run for 3 years and aims to randomize 40 patients. Recruitment will be for 24 months with final follow-up at 1 year post surgery. The third year will also involve collation and analysis of the data. This study will be funded through the NIHR Biomedical Research Unit at the Oxford University Hospitals NHS Trust. Trial registration Current Controlled Trials: ISRCTN10464365 PMID:23758981

Platelet-Rich Plasma-Loaded Poly(d,l-lactide)-Poly(ethylene glycol)-Poly(d,l-lactide) Hydrogel Dressing Promotes Full-Thickness Skin Wound Healing in a Rodent Model

PubMed Central

Qiu, Manle; Chen, Daoyun; Shen, Chaoyong; Shen, Ji; Zhao, Huakun; He, Yaohua

2016-01-01

Traditional therapeutic methods for skin wounds have many disadvantages, and new wound dressings that can facilitate the healing process are thus urgently needed. Platelet-rich plasma (PRP) contains multiple growth factors (GFs) and shows a significant capacity to heal soft tissue wounds. However, these GFs have a short half-life and deactivate rapidly; we therefore need a sustained delivery system to overcome this shortcoming. In this study, poly(d,l-lactide)-poly(ethylene glycol)-poly(d,l-lactide) (PDLLA-PEG-PDLLA: PLEL) hydrogel was successfully created as delivery vehicle for PRP GFs and was evaluated systematically. PLEL hydrogel was injectable at room temperature and exhibited a smart thermosensitive in situ gel-formation behavior at body temperature. In vitro cell culture showed PRP-loaded PLEL hydrogel (PRP/PLEL) had little cytotoxicity, and promoted EaHy926 proliferation, migration and tube formation; the factor release assay additionally indicated that PLEL realized the controlled release of PRP GFs for as long as 14 days. When employed to treat rodents’ full-thickness skin defects, PRP/PLEL showed a significantly better ability to raise the number of both newly formed and mature blood vessels compared to the control, PLEL and PRP groups. Furthermore, the PRP/PLEL-treated group displayed faster wound closure, better reepithelialization and collagen formation. Taken together, PRP/PLEL provides a promising strategy for promoting angiogenesis and skin wound healing, which extends the potential of this dressing for clinical application. PMID:27347938

Angiogenic effect of platelet-rich plasma combined with gelatin hydrogel granules injected into murine subcutis.

PubMed

Kakudo, Natsuko; Morimoto, Naoki; Ogawa, Takeshi; Hihara, Masakatsu; Notodihardjo, Priscilla Valentin; Matsui, Makoto; Tabata, Yasuhiko; Kusumoto, Kenji

2017-07-01

Platelet-rich plasma (PRP), which contains highly concentrated platelets, is produced by centrifuging whole blood. It is a safe and readily available source of a wide range of growth factors necessary for angiogenesis. Gelatin hydrogel granules have been designed and prepared for the controlled release of many growth factors. The angiogenic effect of human PRP was examined in vitro, and the effect of its subcutaneous injection with gelatin hydrogel granules into murine subcutis was evaluated. Human PRP was prepared using a double-spin method. The concentration of growth factors and the platelet count were examined in PRP and in vitro, and the angiogenic activity of human umbilical vein endothelial cells (HUVECs) in co-culture with human dermal fibroblast cells (NHDFs) in the presence and absence of PRP was evaluated. Then, in vivo, PRP, either free or with gelatin hydrogel granules, was injected subcutaneously into tiebacks on mice. Using a microscope and Kurabo angiogenesis image analyser software, the area containing newly formed capillaries was evaluated histologically and the microvascular network score was calculated. PRP was shown to contain high concentrations of PDGF, VEGF and TGFβ and had an angiogenic effect on the co-culture system. PRP with gelatin hydrogel granules significantly enlarged the area containing newly formed capillaries and promoted the microvascular network in murine subcutaneous tissue. PRP encapsulated in gelatin hydrogel microspheres shows promise for enhancing angiogenic effects in murine subcutis and could represent a potential therapeutic combination for the treatment of ischaemic disorders. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

LPS-induced systemic inflammation reveals an immunomodulatory role for the prion protein at the blood-brain interface.

PubMed

Salvesen, Ø; Reiten, M R; Espenes, A; Bakkebø, M K; Tranulis, M A; Ersdal, C

2017-05-22

The cellular prion protein (PrP C ) is an evolutionary conserved protein abundantly expressed not only in the central nervous system but also peripherally including the immune system. A line of Norwegian dairy goats naturally devoid of PrP C (PRNP Ter/Ter ) provides a novel model for studying PrP C physiology. In order to explore putative roles for PrP C in acute inflammatory responses, we performed a lipopolysaccharide (LPS, Escherichia coli O26:B6) challenge of 16 goats (8 PRNP +/+ and 8 PRNP Ter/Ter ) and included 10 saline-treated controls (5 of each PRNP genotype). Clinical examinations were performed continuously, and blood samples were collected throughout the trial. Genome-wide transcription profiles of the choroid plexus, which is at the blood-brain interface, and the hippocampus were analyzed by RNA sequencing, and the same tissues were histologically evaluated. All LPS-treated goats displayed clinical signs of sickness behavior, which were of significantly (p < 0.01) longer duration in animals without PrP C . In the choroid plexus, a substantial alteration of the transcriptome and activation of Iba1-positive cells were observed. This response included genotype-dependent differential expression of several genes associated with the immune response, such as ISG15, CXCL12, CXCL14, and acute phase proteins, among others. Activation of cytokine-responsive genes was skewed towards a more profound type I interferon response, and a less obvious type II response, in PrP C -deficient goats. The magnitude of gene expression in response to LPS was smaller in the hippocampus than in the choroid plexus. Resting state expression profiles revealed a few differences between the PRNP genotypes. Our data suggest that PrP C acts as a modulator of certain pathways of innate immunity signaling, particularly downstream of interferons, and probably contributes to protection of vulnerable tissues against inflammatory damage.

Goats without Prion Protein Display Enhanced Proinflammatory Pulmonary Signaling and Extracellular Matrix Remodeling upon Systemic Lipopolysaccharide Challenge.

PubMed

Salvesen, Øyvind; Reiten, Malin R; Kamstra, Jorke H; Bakkebø, Maren K; Espenes, Arild; Tranulis, Michael A; Ersdal, Cecilie

2017-01-01

A naturally occurring mutation in the PRNP gene of Norwegian dairy goats terminates synthesis of the cellular prion protein (PrP C ), rendering homozygous goats ( PRNP Ter/Ter ) devoid of the protein. Although PrP C has been extensively studied, particularly in the central nervous system, the biological role of PrP C remains incompletely understood. Here, we examined whether loss of PrP C affects the initial stage of lipopolysaccharide (LPS)-induced acute lung injury (ALI). Acute pulmonary inflammation was induced by intravenous injection of LPS ( Escherichia coli O26:B6) in 16 goats (8 PRNP Ter/Ter and 8 PRNP +/+ ). A control group of 10 goats (5 PRNP Ter/Ter and 5 PRNP +/+ ) received sterile saline. Systemic LPS challenge induced sepsis-like clinical signs including tachypnea and respiratory distress. Microscopic examination of lungs revealed multifocal areas with alveolar hemorrhages, edema, neutrophil infiltration, and higher numbers of alveolar macrophages, with no significant differences between PRNP genotypes. A total of 432 ( PRNP +/+ ) and 596 ( PRNP Ter/Ter ) genes were differentially expressed compared with the saline control of the matching genotype. When assigned to gene ontology categories, biological processes involved in remodeling of the extracellular matrix (ECM), were exclusively enriched in PrP C -deficient goats. These genes included a range of collagen-encoding genes, and proteases such as matrix metalloproteinases ( MMP1, MMP2, MMP14, ADAM15 ) and cathepsins. Several proinflammatory upstream regulators (TNF-α, interleukin-1β, IFN-γ) showed increased activation scores in goats devoid of PrP C . In conclusion, LPS challenge induced marked alterations in the lung tissue transcriptome that corresponded with histopathological and clinical findings in both genotypes. The increased activation of upstream inflammatory regulators and enrichment of ECM components could reflect increased inflammation in the absence of PrP C . Further studies are required to elucidate whether these alterations may affect the later reparative phase of ALI.

Effects of three blood derived products on equine corneal cells, an in vitro study.

PubMed

Rushton, J O; Kammergruber, E; Tichy, A; Egerbacher, M; Nell, B; Gabner, S

2018-05-01

Despite advances in therapy of corneal ulcerative diseases in horses, a vast number of cases require surgical intervention, due to poor response to treatment. Topical application of serum has been used for many years, based on its anticollagenolytic properties and the presence of growth factors promoting corneal wound healing. However, although other blood derived products i.e. platelet rich plasma (PRP), plasma rich in growth factors (PRGF) have been widely used in equine orthopaedics and in human ophthalmology, no reports of the effects of these blood derived products exist in equine ophthalmology. To determine in vitro effects of PRGF and PRP on equine corneal cells compared with serum. Prospective controlled cohort study. Blood from 35 healthy horses was used to produce serum, PRGF (Endoret ® ), and PRP (E-PET™). Limbal- and stromal cells were isolated from healthy corneas of six horses and treated with 20% serum, 20% PRGF or 20% PRP. Proliferation rates and migration capacity were analysed in single cell cultures as well as co-culture systems. Cell proliferation increased with PRP treatment, remained constant in PRGF treated cells, and declined upon serum treatment over a period of 48 h. Migration capacity was significantly enhanced with PRP treatment, compared with PRGF treatment. Intact leucocytes, mainly eosinophils, were only detected in PRP. Due to the study design use of autologous blood products on corneal cells was not possible. The results demonstrate beneficial effects of PRP on proliferation as well as migration capacity of equine corneal cells in vitro. In vivo studies are warranted to determine further beneficial effects of PRP in horses with corneal ulcers. © 2017 EVJ Ltd.

Platelet-Rich Plasma in Bone Regeneration: Engineering the Delivery for Improved Clinical Efficacy

PubMed Central

Rodriguez, Isaac A.; Growney Kalaf, Emily A.; Bowlin, Gary L.; Sell, Scott A.

2014-01-01

Human bone is a tissue with a fairly remarkable inherent capacity for regeneration; however, this regenerative capacity has its limitations, and defects larger than a critical size lack the ability to spontaneously heal. As such, the development and clinical translation of effective bone regeneration modalities are paramount. One regenerative medicine approach that is beginning to gain momentum in the clinical setting is the use of platelet-rich plasma (PRP). PRP therapy is essentially a method for concentrating platelets and their intrinsic growth factors to stimulate and accelerate a healing response. While PRP has shown some efficacy in both in vitro and in vivo scenarios, to date its use and delivery have not been optimized for bone regeneration. Issues remain with the effective delivery of the platelet-derived growth factors to a localized site of injury, the activation and temporal release of the growth factors, and the rate of growth factor clearance. This review will briefly describe the physiological principles behind PRP use and then discuss how engineering its method of delivery may ultimately impact its ability to successfully translate to widespread clinical use. PMID:25050347

The mechanism of monomer transfer between two structurally distinct PrP oligomers

PubMed Central

Armiento, Aurora; Martin, Davy; Lepejova, Nad’a

2017-01-01

In mammals, Prion pathology refers to a class of infectious neuropathologies whose mechanism is based on the self-perpetuation of structural information stored in the pathological conformer. The characterisation of the PrP folding landscape has revealed the existence of a plethora of pathways conducing to the formation of structurally different assemblies with different biological properties. However, the biochemical interconnection between these diverse assemblies remains unclear. The PrP oligomerisation process leads to the formation of neurotoxic and soluble assemblies called O1 oligomers with a high size heterodispersity. By combining the measurements in time of size distribution and average size with kinetic models and data assimilation, we revealed the existence of at least two structurally distinct sets of assemblies, termed Oa and Ob, forming O1 assemblies. We propose a kinetic model representing the main processes in prion aggregation pathway: polymerisation, depolymerisation, and disintegration. The two groups interact by exchanging monomers through a disintegration process that increases the size of Oa. Our observations suggest that PrP oligomers constitute a highly dynamic population. PMID:28746342

The mechanism of monomer transfer between two structurally distinct PrP oligomers.

PubMed

Armiento, Aurora; Moireau, Philippe; Martin, Davy; Lepejova, Nad'a; Doumic, Marie; Rezaei, Human

2017-01-01

In mammals, Prion pathology refers to a class of infectious neuropathologies whose mechanism is based on the self-perpetuation of structural information stored in the pathological conformer. The characterisation of the PrP folding landscape has revealed the existence of a plethora of pathways conducing to the formation of structurally different assemblies with different biological properties. However, the biochemical interconnection between these diverse assemblies remains unclear. The PrP oligomerisation process leads to the formation of neurotoxic and soluble assemblies called O1 oligomers with a high size heterodispersity. By combining the measurements in time of size distribution and average size with kinetic models and data assimilation, we revealed the existence of at least two structurally distinct sets of assemblies, termed Oa and Ob, forming O1 assemblies. We propose a kinetic model representing the main processes in prion aggregation pathway: polymerisation, depolymerisation, and disintegration. The two groups interact by exchanging monomers through a disintegration process that increases the size of Oa. Our observations suggest that PrP oligomers constitute a highly dynamic population.

Pathogenic prion protein fragment (PrP106-126) promotes human immunodeficiency virus type-1 infection in peripheral blood monocyte-derived macrophages.

PubMed

Bacot, Silvia M; Feldman, Gerald M; Yamada, Kenneth M; Dhawan, Subhash

2015-02-01

Transfusion of blood and blood products contaminated with the pathogenic form of prion protein Prp(sc), thought to be the causative agent of variant a Creutzfeldt-Jakob disease (vCJD), may result in serious consequences in recipients with a compromised immune system, for example, as seen in HIV-1 infection. In the present study, we demonstrate that treatment of peripheral blood monocyte-derived macrophages (MDM) with PrP106-126, a synthetic domain of PrP(sc) that has intrinsic functional activities related to the full-length protein, markedly increased their susceptibility to HIV-1 infection, induced cytokine secretion, and enhanced their migratory behavior in response to N-formyl-l-methionyl-l-leucyl-l-phenylalanine (fMLP). Live-cell imaging of MDM cultured in the presence of PrP106-126 showed large cell clusters indicative of cellular activation. Tyrosine kinase inhibitor STI-571, protein kinase C inhibitor K252B, and cyclin-dependent kinase inhibitor olomoucine attenuated PrP106-126-induced altered MDM functions. These findings delineate a previously undefined functional role of PrP106-126-mediated host cell response in promoting HIV-1 pathogenesis. Published by Elsevier Inc.

Truncated forms of the prion protein PrP demonstrate the need for complexity in prion structure.

PubMed

Wan, William; Stöhr, Jan; Kendall, Amy; Stubbs, Gerald

2015-01-01

Self-propagation of aberrant protein folds is the defining characteristic of prions. Knowing the structural basis of self-propagation is essential to understanding prions and their related diseases. Prion rods are amyloid fibrils, but not all amyloids are prions. Prions have been remarkably intractable to structural studies, so many investigators have preferred to work with peptide fragments, particularly in the case of the mammalian prion protein PrP. We compared the structures of a number of fragments of PrP by X-ray fiber diffraction, and found that although all of the peptides adopted amyloid conformations, only the larger fragments adopted conformations that modeled the complexity of self-propagating prions, and even these fragments did not always adopt the PrP structure. It appears that the relatively complex structure of the prion form of PrP is not accessible to short model peptides, and that self-propagation may be tied to a level of structural complexity unobtainable in simple model systems. The larger fragments of PrP, however, are useful to illustrate the phenomenon of deformed templating (heterogeneous seeding), which has important biological consequences.

Truncated forms of the prion protein PrP demonstrate the need for complexity in prion structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wan, William; Stöhr, Jan; Kendall, Amy

2015-09-01

Self-propagation of aberrant protein folds is the defining characteristic of prions. Knowing the structural basis of self-propagation is essential to understanding prions and their related diseases. Prion rods are amyloid fibrils, but not all amyloids are prions. Prions have been remarkably intractable to structural studies, so many investigators have preferred to work with peptide fragments, particularly in the case of the mammalian prion protein PrP. We compared the structures of a number of fragments of PrP by X-ray fiber diffraction, and found that although all of the peptides adopted amyloid conformations, only the larger fragments adopted conformations that modeled themore » complexity of self-propagating prions, and even these fragments did not always adopt the PrP structure. It appears that the relatively complex structure of the prion form of PrP is not accessible to short model peptides, and that self-propagation may be tied to a level of structural complexity unobtainable in simple model systems. The larger fragments of PrP, however, are useful to illustrate the phenomenon of deformed templating (heterogeneous seeding), which has important biological consequences.« less

Mechanical and Controlled PRP Injections in Patients Affected by Androgenetic Alopecia.

PubMed

Gentile, Pietro; Garcovich, Simone; Scioli, Maria Giovanna; Bielli, Alessandra; Orlandi, Augusto; Cervelli, Valerio

2018-01-27

23 patients (18 male and 5 female) aged 21-70 years who displayed male pattern hair loss (MPHL) in Stage 1 to Stage 5 as determined by the Norwood-Hamilton classification scale, and female pattern hair loss (FPHL) in Stage 1 to Stage 2 as determined by the Ludwig classification scale, were treated with non-activated autologous platelet-rich plasma (A-PRP). Autologous blood (55 mL) was harvested using sodium citrate as an anticoagulant. A-PRP (23 mL) was produced for all cases using a closed system according to the transfusion service protocol. Following centrifugation (260 x g for 10 min) the A-PRP was inserted in a laser light selector device, and after the centrifugation, 9 mL of A-PRP was collected. The scalp of the patients affected by androgenetic alopecia (AGA) was divided into four areas (frontal, parietal, vertex, and occipital); local anesthesia was not performed. Interfollicular A-PRP injections (0.2 mL x cm 2 ) were performed by controlled and mechanical injections scheduled at a depth of 5 mm using a medical injector gun. Treatment sessions were performed with a 30-day interval. For each patient, three treatment sessions were performed. PRP was injected in the androgen-related areas of scalp affected by hair loss. Placebo (normal saline solution) was loaded in another syringe (10 mL) and injected on the adjacent side in a similar fashion.

Identification of Alprenolol Hydrochloride as an Anti-prion Compound Using Surface Plasmon Resonance Imaging.

PubMed

Miyazaki, Yukiko; Ishikawa, Takeshi; Kamatari, Yuji O; Nakagaki, Takehiro; Takatsuki, Hanae; Ishibashi, Daisuke; Kuwata, Kazuo; Nishida, Noriyuki; Atarashi, Ryuichiro

2018-04-27

Prion diseases are transmissible neurodegenerative disorders of humans and animals, which are characterized by the aggregation of abnormal prion protein (PrP Sc ) in the central nervous system. Although several small compounds that bind to normal PrP (PrP C ) have been shown to inhibit structural conversion of the protein, an effective therapy for human prion disease remains to be established. In this study, we screened 1200 existing drugs approved by the US Food and Drug Administration (FDA) for anti-prion activity using surface plasmon resonance imaging (SPRi). Of these drugs, 31 showed strong binding activity to recombinant human PrP, and three of these reduced the accumulation of PrP Sc in prion-infected cells. One of the active compounds, alprenolol hydrochloride, which is used clinically as a β-adrenergic blocker for hypertension, also reduced the accumulation of PrP Sc in the brains of prion-infected mice at the middle stage of the disease when the drug was administered orally with their daily water from the day after infection. Docking simulation analysis suggested that alprenolol hydrochloride fitted into the hotspot within mouse PrP C , which is known as the most fragile structure within the protein. These findings provide evidence that SPRi is useful in identifying effective drug candidates for neurodegenerative diseases caused by abnormal protein aggregation, such as prion diseases.

Pre-mRNA Processing Factor Prp18 Is a Stimulatory Factor of Influenza Virus RNA Synthesis and Possesses Nucleoprotein Chaperone Activity.

PubMed

Minakuchi, M; Sugiyama, K; Kato, Y; Naito, T; Okuwaki, M; Kawaguchi, A; Nagata, K

2017-02-01

The genome of influenza virus (viral RNA [vRNA]) is associated with the nucleoprotein (NP) and viral RNA-dependent RNA polymerases and forms helical viral ribonucleoprotein (vRNP) complexes. The NP-vRNA complex is the biologically active template for RNA synthesis by the viral polymerase. Previously, we identified human pre-mRNA processing factor 18 (Prp18) as a stimulatory factor for viral RNA synthesis using a Saccharomyces cerevisiae replicon system and a single-gene deletion library of Saccharomyces cerevisiae (T. Naito, Y. Kiyasu, K. Sugiyama, A. Kimura, R. Nakano, A. Matsukage, and K. Nagata, Proc Natl Acad Sci USA, 104:18235-18240, 2007, https://doi.org/10.1073/pnas.0705856104). In infected Prp18 knockdown (KD) cells, the synthesis of vRNA, cRNA, and viral mRNAs was reduced. Prp18 was found to stimulate in vitro viral RNA synthesis through its interaction with NP. Analyses using in vitro RNA synthesis reactions revealed that Prp18 dissociates newly synthesized RNA from the template after the early elongation step to stimulate the elongation reaction. We found that Prp18 functions as a chaperone for NP to facilitate the formation of NP-RNA complexes. Based on these results, it is suggested that Prp18 accelerates influenza virus RNA synthesis as an NP chaperone for the processive elongation reaction. Templates for viral RNA synthesis of negative-stranded RNA viruses are not naked RNA but rather RNA encapsidated by viral nucleocapsid proteins forming vRNP complexes. However, viral basic proteins tend to aggregate under physiological ionic strength without chaperones. We identified the pre-mRNA processing factor Prp18 as a stimulatory factor for influenza virus RNA synthesis. We found that one of the targets of Prp18 is NP. Prp18 facilitates the elongation reaction of viral polymerases by preventing the deleterious annealing of newly synthesized RNA to the template. Prp18 functions as a chaperone for NP to stimulate the formation of NP-RNA complexes. Based on these results, we propose that Prp18 may be required to maintain the structural integrity of vRNP for processive template reading. Copyright © 2017 American Society for Microbiology.

Modification of Pulsed Electric Field Conditions Results in Distinct Activation Profiles of Platelet-Rich Plasma.

PubMed

Frelinger, Andrew L; Gerrits, Anja J; Garner, Allen L; Torres, Andrew S; Caiafa, Antonio; Morton, Christine A; Berny-Lang, Michelle A; Carmichael, Sabrina L; Neculaes, V Bogdan; Michelson, Alan D

2016-01-01

Activated autologous platelet-rich plasma (PRP) used in therapeutic wound healing applications is poorly characterized and standardized. Using pulsed electric fields (PEF) to activate platelets may reduce variability and eliminate complications associated with the use of bovine thrombin. We previously reported that exposing PRP to sub-microsecond duration, high electric field (SMHEF) pulses generates a greater number of platelet-derived microparticles, increased expression of prothrombotic platelet surfaces, and differential release of growth factors compared to thrombin. Moreover, the platelet releasate produced by SMHEF pulses induced greater cell proliferation than plasma. To determine whether sub-microsecond duration, low electric field (SMLEF) bipolar pulses results in differential activation of PRP compared to SMHEF, with respect to profiles of activation markers, growth factor release, and cell proliferation capacity. PRP activation by SMLEF bipolar pulses was compared to SMHEF pulses and bovine thrombin. PRP was prepared using the Harvest SmartPreP2 System from acid citrate dextrose anticoagulated healthy donor blood. PEF activation by either SMHEF or SMLEF pulses was performed using a standard electroporation cuvette preloaded with CaCl2 and a prototype instrument designed to take into account the electrical properties of PRP. Flow cytometry was used to assess platelet surface P-selectin expression, and annexin V binding. Platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), endothelial growth factor (EGF) and platelet factor 4 (PF4), and were measured by ELISA. The ability of supernatants to stimulate proliferation of human epithelial cells in culture was also evaluated. Controls included vehicle-treated, unactivated PRP and PRP with 10 mM CaCl2 activated with 1 U/mL bovine thrombin. PRP activated with SMLEF bipolar pulses or thrombin had similar light scatter profiles, consistent with the presence of platelet-derived microparticles, platelets, and platelet aggregates whereas SMHEF pulses primarily resulted in platelet-derived microparticles. Microparticles and platelets in PRP activated with SMLEF bipolar pulses had significantly lower annexin V-positivity than those following SMHEF activation. In contrast, the % P-selectin positivity and surface P-selectin expression (MFI) for platelets and microparticles in SMLEF bipolar pulse activated PRP was significantly higher than that in SMHEF-activated PRP, but not significantly different from that produced by thrombin activation. Higher levels of EGF were observed following either SMLEF bipolar pulses or SMHEF pulses of PRP than after bovine thrombin activation while VEGF, PDGF, and PF4 levels were similar with all three activating conditions. Cell proliferation was significantly increased by releasates of both SMLEF bipolar pulse and SMHEF pulse activated PRP compared to plasma alone. PEF activation of PRP at bipolar low vs. monopolar high field strength results in differential platelet-derived microparticle production and activation of platelet surface procoagulant markers while inducing similar release of growth factors and similar capacity to induce cell proliferation. Stimulation of PRP with SMLEF bipolar pulses is gentler than SMHEF pulses, resulting in less platelet microparticle generation but with overall activation levels similar to that obtained with thrombin. These results suggest that PEF provides the means to alter, in a controlled fashion, PRP properties thereby enabling evaluation of their effects on wound healing and clinical outcomes.

Oil Spill Cleanup

NASA Technical Reports Server (NTRS)

1994-01-01

Petroleum Remediation Product (PRP) is a new way of cleaning up oil spills. It consists of thousands of microcapsules, tiny balls of beeswax with hollow centers, containing live microorganisms and nutrients to sustain them. As oil flows through the microcapsule's shell, it is consumed and digested by the microorganisms. Pressure buildup causes the PRP to explode and the enzymes, carbon dioxide and water are released into the BioBoom used in conjunction with PRP, preventing contaminated water from spreading. The system incorporates technology originally developed at the Jet Propulsion Laboratory and Marshall Space Flight Center.

Protective Effect of Platelet Rich Plasma on Experimental Ischemia/Reperfusion Injury in Rat Ovary.

PubMed

Bakacak, Murat; Bostanci, Mehmet Suhha; İnanc, Fatma; Yaylali, Asli; Serin, Salih; Attar, Rukset; Yildirim, Gazi; Yildirim, Ozge Kizilkale

2016-01-01

Ovarian torsion is a common cause of local ischemic damage, reduced follicular activity and infertility. Platelet-rich plasma (PRP) contains growth factors with demonstrated cytoprotective properties; so we evaluated PRP efficacy in a rat ischemia/reperfusion (I/R) model. Sixty adult female Sprague-Dawley albino rats were randomly assigned to 6 groups of 8 animals each: Sham, Ischemia, I/R, Sham + PRP, I + PRP and I/R + PRP; and the remaining 12 used to prepare PRP. Ischemia groups were subjected to bilateral adnexal torsion for 3 h, while I/R and I/R + PRP groups received subsequent detorsion for 3 h. Intraperitoneal PRP was administered 30 min prior to ischemia (Ischemia + PRP) or reperfusion (I/R + PRP). Total oxidant status (TOS), oxidative stress index (OSI) and total ovarian histopathological scores were higher in Ischemia and I/R groups than in the Sham group (p < 0.05). PRP decreased mean TOS, OSI and histopathological scores in I + PRP and I/R + PRP groups compared to the corresponding Ischemia and I/R groups (p < 0.001). There was a strong correlation between total histopathological score and OSI (r = 0.877, p < 0.001). Peritoneal vascular endothelial growth factor was significantly higher in PRP-treated groups than corresponding untreated groups (p < 0.05). PRP is effective for the prevention of ischemia and reperfusion damage in rat ovary. © 2015 S. Karger AG, Basel.

Mechanism of Unfolding of Human Prion Protein.

PubMed

Singh, Reman K; Chamachi, Neharika G; Chakrabarty, Suman; Mukherjee, Arnab

2017-01-26

Misfolding and aggregation of prion proteins are associated with several neurodegenerative diseases. Therefore, understanding the mechanism of the misfolding process is of enormous interest in the scientific community. It has been speculated and widely discussed that the native cellular prion protein (PrP C ) form needs to undergo substantial unfolding to a more stable PrP C* state, which may further oligomerize into the toxic scrapie (PrP Sc ) form. Here, we have studied the mechanism of the unfolding of the human prion protein (huPrP) using a set of extensive well-tempered metadynamics simulations. Through multiple microsecond-long metadynamics simulations, we find several possible unfolding pathways. We show that each pathway leads to an unfolded state of lower free energy than the native state. Thus, our study may point to the signature of a PrP C* form that corresponds to a global minimum on the conformational free-energy landscape. Moreover, we find that these global minima states do not involve an increased β-sheet content, as was assumed to be a signature of PrP Sc formation in previous simulation studies. We have further analyzed the origin of metastability of the PrP C form through free-energy surfaces of the chopped helical segments to show that the helices, particularly H2 and H3 of the prion protein, have the tendency to form either a random coil or a β-structure. Therefore, the secondary structural elements of the prion protein are only weakly stabilized by tertiary contacts and solvation forces so that relatively weak perturbations induced by temperature, pressure, pH, and so forth can lead to substantial unfolding with characteristics of intrinsically disordered proteins.

Immunogenicity and safety of a fully liquid aluminum phosphate adjuvanted Haemophilus influenzae type b PRP-CRM197-conjugate vaccine in healthy Japanese children: A phase III, randomized, observer-blind, multicenter, parallel-group study.

PubMed

Togashi, Takehiro; Mitsuya, Nodoka; Kogawara, Osamu; Sumino, Shuji; Takanami, Yohei; Sugizaki, Kayoko

2016-08-31

Broad use of monovalent Haemophilus influenzae type b (Hib) conjugate vaccines based on the capsular polysaccharide polyribosyl-ribitol phosphate (PRP), has significantly reduced invasive Hib disease burden in children worldwide, particularly in children aged <1year. In Japan, PRP conjugated to tetanus toxoid (PRP-T) vaccine has been widely used since the initiation of public funding programs followed by a routine vaccination designation in 2013. We compared the immunogenicity and safety of PRP conjugated to a non-toxic diphtheria toxin mutant (PRP-CRM197) vaccine with the PRP-T vaccine when administered subcutaneously to healthy Japanese children in a phase III study. Additionally, we evaluated the immunogenicity and safety profiles of a diphtheria-tetanus acellular pertussis (DTaP) combination vaccine when concomitantly administered with either PRP-CRM197 or PRP-T vaccines. The primary endpoint was the "long-term seroprotection rate", defined as the group proportion with anti-PRP antibody titers ⩾1.0μg/mL, after the primary series. Long-term seroprotection rates were 99.3% in the PRP-CRM197 group and 95.6% in the PRP-T group. The intergroup difference (PRP-CRM197 group - PRP-T group) was 3.7% (95% confidence interval: 0.099-7.336), demonstrating that PRP-CRM197 vaccine was non-inferior to PRP-T vaccine (p<0.0001). Furthermore, the "short-term seroprotection rate" (anti-PRP antibody titer ⩾0.15μg/mL) before booster vaccination was higher in the PRP-CRM197 group than in PRP-T. Concomitant administration of PRP-CRM197 vaccine with DTaP vaccine showed no differences in terms of immunogenicity compared with concomitant vaccination with PRP-T vaccine and DTaP vaccine. Although CRM197 vaccine had higher local reactogenicity, overall, both Hib vaccines had acceptable safety and tolerability profiles. The immunogenicity of PRP-CRM197 vaccine administered subcutaneously as a three-dose primary series in children followed by a booster vaccination 1year after the primary series induced protective levels of Hib antibodies with no safety or tolerability concerns. Registered on ClinicalTrials.gov: NCT01379846. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Platelet-rich plasma inhibits the apoptosis of highly adipogenic homogeneous preadipocytes in an in vitro culture system.

PubMed

Fukaya, Yoshitaka; Kuroda, Masayuki; Aoyagi, Yasuyuki; Asada, Sakiyo; Kubota, Yoshitaka; Okamoto, Yoshitaka; Nakayama, Toshinori; Saito, Yasushi; Satoh, Kaneshige; Bujo, Hideaki

2012-05-31

Auto-transplantation of adipose tissue is commonly used for the treatment of tissue defects in plastic surgery. The survival of the transplanted adipose tissue is not always constant, and one of reasons is the accelerated apoptosis of the implanted preadipocytes. We have recently established highly homogeneous preadipocytes, named ccdPAs. The aim of the current study was to evaluate the regulation of the potency of platelet-rich plasma (PRP) on the apoptosis of ccdPAs in vitro. PRP stimulated the proliferation of the preadipocytes in a dose-dependent manner, and the stimulatory activity of 2% PRP was significantly higher than that of 2% FBS or 2% platelet-poor plasma (PPP). The presence of 2% PRP significantly inhibited serum starvation- or TNF-α/cycloheximide-induced apoptosis in comparison to 2% FBS or 2% PPP. DAPK1 and Bcl-2-interacting mediator of cell death (BIM) mRNAs were reduced in the preadipocytes cultured with 2% PRP in comparison to those cultured in 2% FBS. The gene expression levels were significantly higher in cells cultured without serum in comparison to cells cultured with 2% FBS, and the levels in the cells with 2% PRP were reduced to 5-10% of those in the cells without serum. These results indicated that ccdPAs exhibit anti- apoptotic activities, in addition to increased proliferation, when cultured in 2% PRP in comparison to the same concentration of FBS, and that this was accompanied with reduced levels of DAPK1 and BIM mRNA expression in in vitro culture. PRP may improve the outcome of transplantation of adipose tissue by enhancing the anti-apoptotic activities of the implanted preadipocytes.

A systematic review of the use of platelet-rich plasma in sports medicine as a new treatment for tendon and ligament injuries.

PubMed

Taylor, Drew W; Petrera, Massimo; Hendry, Mike; Theodoropoulos, John S

2011-07-01

To evaluate, through a systematic review of the current literature, the evidence-based outcomes of the use of platelet-rich plasma (PRP) for the treatment of tendon and ligament injuries. A search of English-language articles was performed in PubMed and EMBASE using keywords "PRP," "platelet plasma," and "platelet concentrate" combined with "tendon" and then "ligament" independently. The search was conducted through September 2010. Search was limited to in vivo studies. Nonhuman studies were excluded. Tissue engineering strategies, which included a combination of PRP with additional cell types (bone marrow), were also excluded. Articles with all levels of evidence were included. Thirteen of 32 retrieved articles respected the inclusion criteria. The authors reviewed and tabulated data according to the year of study and journal, study type and level of evidence, patient demographics, method of PRP preparation, site of application, and outcomes. The selected studies focused on the application of PRP in the treatment of patellar and elbow tendinosis, Achilles tendon injuries, rotator cuff repair, and anterior cruciate ligament (ACL) reconstruction. Seven studies demonstrated favorable outcomes in tendinopathies in terms of improved pain and functional scores. In 3 studies on the use of PRP in ACL reconstruction, no statistically significant differences were seen with regard to clinical outcomes, tunnel widening, and graft integration. One study examined the systemic effects after the local PRP application for patellar and elbow tendinosis. Presently, PRP use in tendon and ligament injuries has several potential advantages, including faster recovery and, possibly, a reduction in recurrence, with no adverse reactions described. However, only 3 randomized clinical trials have been conducted.

Efficacy of platelet-rich plasma in arthroscopic repair of full-thickness rotator cuff tears: a meta-analysis.

PubMed

Cai, You-zhi; Zhang, Chi; Lin, Xiang-jin

2015-12-01

The use of platelet-rich plasma (PRP) is an innovative clinical therapy, especially in arthroscopic rotator cuff repair. The purpose of this study was to compare the clinical improvement and tendon-to-bone healing with and without PRP therapy in arthroscopic rotator cuff repair. A systematic search was done in the major medical databases to evaluate the studies using PRP therapy (PRP+) or with no PRP (PRP-) for the treatment of patients with rotator cuff tears. We reviewed clinical scores such as the Constant score, the American Shoulder and Elbow Surgeons score, the University of California at Los Angeles (UCLA) Shoulder Rating Scale, the Simple Shoulder Test, and the failure-to-heal rate by magnetic resonance imaging between PRP+ and PRP- groups. Five studies included in this review were used for a meta-analysis based on data availability. There were no statistically significant differences between PRP+ and PRP- groups for overall outcome scores (P > .05). However, the PRP+ group exhibited better healing rates postoperatively than the PRP- group (P = .03) in small/moderate full-thickness tears. The use of PRP therapy in full-thickness rotator cuff repairs showed no statistically significant difference compared with no PRP therapy in clinical outcome scores, but the failure-to-heal rate was significantly decreased when PRP was used for treatment of small-to-moderately sized tears. PRP therapy may improve tendon-to-bone healing in patients with small or moderate rotator cuff tears. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Short term storage stability at room temperature of two different platelet-rich plasma preparations from equine donors and potential impact on growth factor concentrations.

PubMed

Hauschild, Gregor; Geburek, Florian; Gosheger, Georg; Eveslage, Maria; Serrano, Daniela; Streitbürger, Arne; Johannlükens, Sara; Menzel, Dirk; Mischke, Reinhard

2017-01-05

The increasing interest in platelet-rich plasma (PRP) based therapies is as yet accompanied by inconsistent information regarding nearly all aspects of handling and application. Among these storage stability of processed platelet-rich products may be the basis for a more flexible application mode. The objective of this study was (1) to estimate the storage stability of growth factors platelet derived growth factor BB (PDGF-BB) and transforming growth factor ß1 (TGF-ß1) in both, a single-step softspin centrifugation-based pure-PRP (P-PRP, ACP®), and a gravity filtration system-based leukocyte-rich-PRP (L-PRP, E-PET), over a six hours time span after preparation at room temperature and (2) to identify possible factors influencing these growth factor concentrations in an equine model. Growth factor concentrations remained stable over the entire investigation period in L-PRP as well as P-PRP preparations revealing a mean of 3569 pg/ml PDGF-BB for E-PET and means of 1276 pg/ml PDGF-BB and 5086 pg/ml TGF-ß1 for ACP®. Pearson correlations yielded no significant impact of whole blood platelet (PLT), white blood cell (WBC) and red blood cell (RBC) counts on resulting cytokine values. In case of ACP® no significant dependencies between PLT, WBC and RBC counts of the processed platelet-rich product and resulting cytokine content occurred with exception of TGF-ß1 concentrations showing a strong correlation with the WBC content. PDGF-BB content of E-PET preparations showed a strong positive correlation with PLT and a strong negative with WBC of these preparations but not with RBC. L-PRP ad modum E-PET and P-PRP ad modum ACP® are applicable over at least a six hours time span at room temperature without loss of growth factor content. Based on the results of this study factors influencing the resulting growth factor concentrations still remain questionable. Additional studies implicating a further standardization of preparation protocols are necessary to identify consistent impact on cytokine content after PRP processing.

Unique inflammatory RNA profiles of microglia in Creutzfeldt-Jakob disease

NASA Astrophysics Data System (ADS)

Baker, Christopher A.; Manuelidis, Laura

2003-01-01

Previous studies in Creutzfeldt-Jakob disease (CJD) have shown that myeloid cells in the periphery as well as derivative microglial cells in the brain are infectious. Microglia can show an activated phenotype before prion protein (PrP) pathology is detectable in brain, and isolated infectious microglia contain very little PrP. To find whether a set of inflammatory genes are significantly induced or suppressed with infection, we analyzed RNA from isolated microglia with relevant cDNA arrays, and identified 30 transcripts not previously examined in any transmissible spongiform encephalopathy. This CJD expression profile contrasted with that of uninfected microglia exposed to prototypic inflammatory stimuli such as lipopolysaccharide and IFN-, as well as PrP amyloid. These findings underscore inflammatory pathways evoked by the infectious agent in brain. Transcript profiles unique for CJD microglia and other myeloid cells provide opportunities for more sensitive preclinical diagnoses of infectious and noninfectious neurodegenerative diseases.

Cell bricks-enriched platelet-rich plasma gel for injectable cartilage engineering - an in vivo experiment in nude mice.

PubMed

Zhu, Jun; Cai, Bolei; Ma, Qin; Chen, Fulin; Wu, Wei

2013-10-01

Clinical application of platelet-rich plasma (PRP)-based injectable tissue engineering is limited by weak mechanical properties and a rapid fibrinolytic rate. We proposed a new strategy, a cell bricks-stabilized PRP injectable system, to engineer and regenerate cartilage with stable morphology and structure in vivo. Chondrocytes from the auricular cartilage of rabbits were isolated and cultured to form cell bricks (fragmented cell sheet) or cell expansions. Fifteen nude mice were divided evenly (n = 5) into cells-PRP (C-P), cell bricks-PRP (CB-P) and cell bricks-cells-PRP (CB-C-P) groups. Cells, cell bricks or a cell bricks/cells mixture were suspended in PRP and were injected subcutaneously in animals. After 8 weeks, all the constructs were replaced by white resilient tissue; however, specimens from the CB-P and CB-C-P groups were well maintained in shape, while the C-P group appeared distorted, with a compressed outline. Histologically, all groups presented lacuna-like structures, glycosaminoglycan-enriched matrices and positive immunostaining of collagen type II. Different from the uniform structure presented in CB-C-P samples, CB-P presented interrupted, island-like chondrogenesis and contracted structure; fibrous interruption was shown in the C-P group. The highest percentage of matrix was presented in CB-C-P samples. Collagen and sGAG quantification confirmed that the CB-C-P constructs had statistically higher amounts than the C-P and CB-P groups; statistical differences were also found among the groups in terms of biomechanical properties and gene expression. We concluded that cell bricks-enriched PRP gel sufficiently enhanced the morphological stability of the constructs, maintained chondrocyte phenotypes and favoured chondrogenesis in vivo, which suggests that such an injectable, completely biological system is a suitable cell carrier for cell-based cartilage repair. Copyright © 2012 John Wiley & Sons, Ltd.

Flow Cytometric Detection of PrPSc in Neurons and Glial Cells from Prion-Infected Mouse Brains.

PubMed

Yamasaki, Takeshi; Suzuki, Akio; Hasebe, Rie; Horiuchi, Motohiro

2018-01-01

In prion diseases, an abnormal isoform of prion protein (PrP Sc ) accumulates in neurons, astrocytes, and microglia in the brains of animals affected by prions. Detailed analyses of PrP Sc -positive neurons and glial cells are required to clarify their pathophysiological roles in the disease. Here, we report a novel method for the detection of PrP Sc in neurons and glial cells from the brains of prion-infected mice by flow cytometry using PrP Sc -specific staining with monoclonal antibody (MAb) 132. The combination of PrP Sc staining and immunolabeling of neural cell markers clearly distinguished neurons, astrocytes, and microglia that were positive for PrP Sc from those that were PrP Sc negative. The flow cytometric analysis of PrP Sc revealed the appearance of PrP Sc -positive neurons, astrocytes, and microglia at 60 days after intracerebral prion inoculation, suggesting the presence of PrP Sc in the glial cells, as well as in neurons, from an early stage of infection. Moreover, the kinetic analysis of PrP Sc revealed a continuous increase in the proportion of PrP Sc -positive cells for all cell types with disease progression. Finally, we applied this method to isolate neurons, astrocytes, and microglia positive for PrP Sc from a prion-infected mouse brain by florescence-activated cell sorting. The method described here enables comprehensive analyses specific to PrP Sc -positive neurons, astrocytes, and microglia that will contribute to the understanding of the pathophysiological roles of neurons and glial cells in PrP Sc -associated pathogenesis. IMPORTANCE Although formation of PrP Sc in neurons is associated closely with neurodegeneration in prion diseases, the mechanism of neurodegeneration is not understood completely. On the other hand, recent studies proposed the important roles of glial cells in PrP Sc -associated pathogenesis, such as the intracerebral spread of PrP Sc and clearance of PrP Sc from the brain. Despite the great need for detailed analyses of PrP Sc -positive neurons and glial cells, methods available for cell type-specific analysis of PrP Sc have been limited thus far to microscopic observations. Here, we have established a novel high-throughput method for flow cytometric detection of PrP Sc in cells with more accurate quantitative performance. By applying this method, we succeeded in isolating PrP Sc -positive cells from the prion-infected mouse brains via fluorescence-activated cell sorting. This allows us to perform further detailed analysis specific to PrP Sc -positive neurons and glial cells for the clarification of pathological changes in neurons and pathophysiological roles of glial cells. Copyright © 2017 American Society for Microbiology.

The Use of Platelet-Rich and Platelet-Poor Plasma to Enhance Differentiation of Skeletal Myoblasts: Implications for the Use of Autologous Blood Products for Muscle Regeneration.

PubMed

Miroshnychenko, Olga; Chang, Wen-Teh; Dragoo, Jason L

2017-03-01

Platelet-rich plasma (PRP) has been used to augment tissue repair and regeneration after musculoskeletal injury. However, there is increasing clinical evidence that PRP does not show a consistent clinical effect. Purpose/Hypothesis: This study aimed to compare the effects of the following non-neutrophil-containing (leukocyte-poor) plasma fractions on human skeletal muscle myoblast (HSMM) differentiation: (1) PRP, (2) modified PRP (Mod-PRP), in which transforming growth factor β1 (TGF-β1) and myostatin (MSTN) were depleted, and (3) platelet-poor plasma (PPP). The hypothesis was that leukocyte-poor PRP would lead to myoblast proliferation (not differentiation), whereas certain modifications of PRP preparations would increase myoblast differentiation, which is necessary for skeletal muscle regeneration. Controlled laboratory study. Blood from 7 human donors was individually processed to simultaneously create leukocyte-poor fractions: PRP, Mod-PRP, PPP, and secondarily spun PRP and Mod-PRP (PRP ss and Mod-PRP ss , respectively). Mod-PRP was produced by removing TGF-β1 and MSTN from PRP using antibodies attached to sterile beads, while a second-stage centrifugal spin of PRP was performed to remove platelets. The biologics were individually added to cell culture groups. Analysis for induction into myoblast differentiation pathways included Western blot analysis, reverse-transcription polymerase chain reaction, and immunohistochemistry, as well as confocal microscopy to assess polynucleated myotubule formation. HSMMs cultured with PRP showed an increase in proliferation but no evidence of differentiation. Western blot analysis confirmed that MSTN and TGF-β1 could be decreased in Mod-PRP using antibody-coated beads, but this modification mildly improved myoblast differentiation. However, cell culture with PPP, PRP ss , and Mod-PRP ss led to a decreased proliferation rate but a significant induction of myoblast differentiation verified by increased multinucleated myotubule formation and myosin heavy chain expression (mean 8-fold change in mRNA level; P < .05), which was comparable with 2% horse serum, the positive control. PPP and leukocyte-poor PRP preparations subjected to a second spin to remove the platelets led to induction of myoblast cells into the muscle differentiation pathway, whereas unmodified leukocyte-poor PRP led to myoblast proliferation. These results indicate that traditionally formulated PRP may not be appropriate to induce muscle regeneration. Laboratory evidence suggests that PPP or non-neutrophil-containing PRP ss , subjected to an additional spin to remove platelets, should be used to stimulate myoblast differentiation, which is necessary for skeletal muscle regeneration. Clinical studies will be required to confirm the effect of these biologics on muscle regeneration.

Genetic variation of the prion protein gene (PRNP) in alpaca (Vicugna pacos)

USDA-ARS?s Scientific Manuscript database

Transmissible spongiform encephalopathies (TSE) are caused by accumulation of a misfolded form of the prion protein (PrP). The normal cellular isoform of PrP is produced by the prion gene (PRNP) and is highly expressed in the central nervous system. Currently, there is an absence of information rega...

FgPrp4 Kinase Is Important for Spliceosome B-Complex Activation and Splicing Efficiency in Fusarium graminearum

PubMed Central

Jiang, Cong; Li, Yang; Li, Chaohui; Liu, Huiquan; Kang, Zhensheng; Xu, Jin-Rong

2016-01-01

PRP4 encodes the only kinase among the spliceosome components. Although it is an essential gene in the fission yeast and other eukaryotic organisms, the Fgprp4 mutant was viable in the wheat scab fungus Fusarium graminearum. Deletion of FgPRP4 did not block intron splicing but affected intron splicing efficiency in over 60% of the F. graminearum genes. The Fgprp4 mutant had severe growth defects and produced spontaneous suppressors that were recovered in growth rate. Suppressor mutations were identified in the PRP6, PRP31, BRR2, and PRP8 orthologs in nine suppressor strains by sequencing analysis with candidate tri-snRNP component genes. The Q86K mutation in FgMSL1 was identified by whole genome sequencing in suppressor mutant S3. Whereas two of the suppressor mutations in FgBrr2 and FgPrp8 were similar to those characterized in their orthologs in yeasts, suppressor mutations in Prp6 and Prp31 orthologs or FgMSL1 have not been reported. Interestingly, four and two suppressor mutations identified in FgPrp6 and FgPrp31, respectively, all are near the conserved Prp4-phosphorylation sites, suggesting that these mutations may have similar effects with phosphorylation by Prp4 kinase. In FgPrp31, the non-sense mutation at R464 resulted in the truncation of the C-terminal 130 aa region that contains all the conserved Prp4-phosphorylation sites. Deletion analysis showed that the N-terminal 310-aa rich in SR residues plays a critical role in the localization and functions of FgPrp4. We also conducted phosphoproteomics analysis with FgPrp4 and identified S289 as the phosphorylation site that is essential for its functions. These results indicated that FgPrp4 is critical for splicing efficiency but not essential for intron splicing, and FgPrp4 may regulate pre-mRNA splicing by phosphorylation of other components of the tri-snRNP although itself may be activated by phosphorylation at S289. PMID:27058959

Short-Term Storage of Platelet-Rich Plasma at Room Temperature Does Not Affect Growth Factor or Catabolic Cytokine Concentration.

PubMed

Wilson, Brooke H; Cole, Brian J; Goodale, Margaret B; Fortier, Lisa A

2018-04-01

The aim of this study was to provide clinical recommendations about the use of platelet-rich plasma (PRP) that was subjected to short-term storage at room temperature. We determined bioactive growth factor and cytokine concentrations as indicators of platelet and white blood cell degranulation in blood and PRP. Additionally, this study sought to validate the use of manual, direct smear analysis as an alternative to automated methods for platelet quantification in PRP. Blood was used to generate low-leukocyte PRP (Llo PRP) or high-leukocyte PRP (Lhi PRP). Blood was either processed immediately or kept at room temperature for 2 or 4 hours prior to generation of PRP, which was then held at room temperature for 0, 1, 2, or 4 hours. Subsequently, bioactive transforming growth factor beta-1 and matrix metalloproteinase-9 were measured by ELISA (enzyme-linked immunosorbent assay). Manual and automated platelet counts were performed on all blood and PRP samples. There were no differences in growth factor or cytokine concentration when blood or Llo PRP or Lhi PRP was retained at room temperature for up to 4 hours. Manual, direct smear analysis for platelet quantification was not different from the use of automated machine counting for PRP samples, but in the starting blood samples, manual platelet counts were significantly higher than those generated using automated technology. When there is a delay of up to 4 hours in the generation of PRP from blood or in the application of PRP to the patient, bioactive growth factor and cytokine concentrations remain stable in both blood and PRP. A manual direct counting method is a simple, cost-effective, and valid method to measure the contents of the PRP product being delivered to the patient.

Pathways of Prion Spread during Early Chronic Wasting Disease in Deer.

PubMed

Hoover, Clare E; Davenport, Kristen A; Henderson, Davin M; Denkers, Nathaniel D; Mathiason, Candace K; Soto, Claudio; Zabel, Mark D; Hoover, Edward A

2017-05-15

Among prion infections, two scenarios of prion spread are generally observed: (i) early lymphoid tissue replication or (ii) direct neuroinvasion without substantial antecedent lymphoid amplification. In nature, cervids are infected with chronic wasting disease (CWD) prions by oral and nasal mucosal exposure, and studies of early CWD pathogenesis have implicated pharyngeal lymphoid tissue as the earliest sites of prion accumulation. However, knowledge of chronological events in prion spread during early infection remains incomplete. To investigate this knowledge gap in early CWD pathogenesis, we exposed white-tailed deer to CWD prions by mucosal routes and performed serial necropsies to assess PrP CWD tissue distribution by real-time quaking-induced conversion (RT-QuIC) and tyramide signal amplification immunohistochemistry (TSA-IHC). Although PrP CWD was not detected by either method in the initial days (1 and 3) postexposure, we observed PrP CWD seeding activity and follicular immunoreactivity in oropharyngeal lymphoid tissues at 1 and 2 months postexposure (MPE). At 3 MPE, PrP CWD replication had expanded to all systemic lymphoid tissues. By 4 MPE, the PrP CWD burden in all lymphoid tissues had increased and approached levels observed in terminal disease, yet there was no evidence of nervous system invasion. These results indicate the first site of CWD prion entry is in the oropharynx, and the initial phase of prion amplification occurs in the oropharyngeal lymphoid tissues followed by rapid dissemination to systemic lymphoid tissues. This lymphoid replication phase appears to precede neuroinvasion. IMPORTANCE Chronic wasting disease (CWD) is a universally fatal transmissible spongiform encephalopathy affecting cervids, and natural infection occurs through oral and nasal mucosal exposure to infectious prions. Terminal disease is characterized by PrP CWD accumulation in the brain and lymphoid tissues of affected animals. However, the initial sites of prion accumulation and pathways of prion spread during early CWD infection remain unknown. To investigate the chronological events of early prion pathogenesis, we exposed deer to CWD prions and monitored the tissue distribution of PrP CWD over the first 4 months of infection. We show CWD uptake occurs in the oropharynx with initial prion replication in the draining oropharyngeal lymphoid tissues, rapidly followed by dissemination to systemic lymphoid tissues without evidence of neuroinvasion. These data highlight the two phases of CWD infection: a robust prion amplification in systemic lymphoid tissues prior to neuroinvasion and establishment of a carrier state. Copyright © 2017 American Society for Microbiology.

Comparative outcomes of open-wedge high tibial osteotomy with platelet-rich plasma alone or in combination with mesenchymal stem cell treatment: a prospective study.

PubMed

Koh, Yong-Gon; Kwon, Oh-Ryong; Kim, Yong-Sang; Choi, Yun-Jin

2014-11-01

This study compared the clinical results and second-look arthroscopic findings of patients undergoing open-wedge high tibial osteotomy (HTO) for varus deformity, with or without mesenchymal stem cell (MSC) therapy. This prospective, comparative observational study was designed to evaluate the effectiveness of MSC therapy. The patients were divided into 2 groups: HTO with platelet-rich plasma (PRP) injection only (n = 23) or HTO in conjunction with MSC therapy and PRP injection (n = 21). Prospective evaluations of both groups were performed using the Lysholm score, Knee Injury and Osteoarthritis Outcome Score (KOOS), and a visual analog scale (VAS) score for pain. Second-look arthroscopy was carried out in all patients at the time of metal removal. The patients in the MSC-PRP group showed significantly greater improvements in the KOOS subscales for pain (PRP only, 74.0 ± 5.7; MSC-PRP, 81.2 ± 6.9; P < .001) and symptoms (PRP only, 75.4 ± 8.5; MSC-PRP, 82.8 ± 7.2; P = .006) relative to the PRP-only group. Although the mean Lysholm score was similarly improved in both groups (PRP only, 80.6 ± 13.5; MSC-PRP, 84.7 ± 16.2; P = .357), the MSC-PRP group showed a significantly greater improvement in the VAS pain score (PRP only, 16.2 ± 4.6; MSC-PRP, 10.2 ± 5.7; P < .001). There were no differences in the preoperative (PRP only, varus 2.8° ± 1.7°; MSC-PRP, varus 3.4° ± 3.0°; P = .719) and postoperative (PRP only, valgus 9.8° ± 2.4°; MSC-PRP, valgus 8.7° ± 2.3°; P = .678) femorotibial angles or weight-bearing lines between the groups. Arthroscopic evaluation, at plate removal, showed that partial or even fibrocartilage coverage was achieved in 50% of the MSC-PRP group patients but in only 10% of the patients in the PRP-only group (P < .001). MSC therapy, in conjunction with HTO, mildly improved cartilage healing and showed good clinical results in some KOOS subscores and the VAS pain score compared with PRP only. Level II, prospective comparative study. Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Epithelial and endothelial expression of the green fluorescent protein reporter gene under the control of bovine prion protein (PrP) gene regulatory sequences in transgenic mice

NASA Astrophysics Data System (ADS)

Lemaire-Vieille, Catherine; Schulze, Tobias; Podevin-Dimster, Valérie; Follet, Jérome; Bailly, Yannick; Blanquet-Grossard, Françoise; Decavel, Jean-Pierre; Heinen, Ernst; Cesbron, Jean-Yves

2000-05-01

The expression of the cellular form of the prion protein (PrPc) gene is required for prion replication and neuroinvasion in transmissible spongiform encephalopathies. The identification of the cell types expressing PrPc is necessary to understanding how the agent replicates and spreads from peripheral sites to the central nervous system. To determine the nature of the cell types expressing PrPc, a green fluorescent protein reporter gene was expressed in transgenic mice under the control of 6.9 kb of the bovine PrP gene regulatory sequences. It was shown that the bovine PrP gene is expressed as two populations of mRNA differing by alternative splicing of one 115-bp 5' untranslated exon in 17 different bovine tissues. The analysis of transgenic mice showed reporter gene expression in some cells that have been identified as expressing PrP, such as cerebellar Purkinje cells, lymphocytes, and keratinocytes. In addition, expression of green fluorescent protein was observed in the plexus of the enteric nervous system and in a restricted subset of cells not yet clearly identified as expressing PrP: the epithelial cells of the thymic medullary and the endothelial cells of both the mucosal capillaries of the intestine and the renal capillaries. These data provide valuable information on the distribution of PrPc at the cellular level and argue for roles of the epithelial and endothelial cells in the spread of infection from the periphery to the brain. Moreover, the transgenic mice described in this paper provide a model that will allow for the study of the transcriptional activity of the PrP gene promoter in response to scrapie infection.

Comparison of point-of-care methods for preparation of platelet concentrate (platelet-rich plasma).

PubMed

Weibrich, Gernot; Kleis, Wilfried K G; Streckbein, Philipp; Moergel, Maximilian; Hitzler, Walter E; Hafner, Gerd

2012-01-01

This study analyzed the concentrations of platelets and growth factors in platelet-rich plasma (PRP), which are likely to depend on the method used for its production. The cellular composition and growth factor content of platelet concentrates (platelet-rich plasma) produced by six different procedures were quantitatively analyzed and compared. Platelet and leukocyte counts were determined on an automatic cell counter, and analysis of growth factors was performed using enzyme-linked immunosorbent assay. The principal differences between the analyzed PRP production methods (blood bank method of intermittent flow centrifuge system/platelet apheresis and by the five point-of-care methods) and the resulting platelet concentrates were evaluated with regard to resulting platelet, leukocyte, and growth factor levels. The platelet counts in both whole blood and PRP were generally higher in women than in men; no differences were observed with regard to age. Statistical analysis of platelet-derived growth factor AB (PDGF-AB) and transforming growth factor β1 (TGF-β1) showed no differences with regard to age or gender. Platelet counts and TGF-β1 concentration correlated closely, as did platelet counts and PDGF-AB levels. There were only rare correlations between leukocyte counts and PDGF-AB levels, but comparison of leukocyte counts and PDGF-AB levels demonstrated certain parallel tendencies. TGF-β1 levels derive in substantial part from platelets and emphasize the role of leukocytes, in addition to that of platelets, as a source of growth factors in PRP. All methods of producing PRP showed high variability in platelet counts and growth factor levels. The highest growth factor levels were found in the PRP prepared using the Platelet Concentrate Collection System manufactured by Biomet 3i.

Effects of the A117V mutation on the folding and aggregation of palindromic sequences (PrP113-120) in prion: insights from replica exchange molecular dynamics simulations.

PubMed

Ning, Lulu; Wang, Qianqian; Zheng, Yang; Liu, Huanxiang; Yao, Xiaojun

2015-02-01

The palindromic region AGAAAAGA (PrP113-120) in prion is highly amyloidogenic and very critical in the structural conversion of cellular prion protein to its pathogenetic form. In this region, there is an important point mutation A117V, which is closely related to the occurrence of Gerstmann-Straussler-Scheinker Syndrome. However, the detailed knowledge about the effects of the A117V mutation on the folding and aggregation of the palindromic sequences is still lacking. To investigate the impacts of A117V mutation on the earliest steps along the PrP113-120 aggregation pathway, replica exchange molecular dynamics simulations of the monomer, 2- and 4-peptide systems of PrP113-120 and its A117V mutant were carried out. The simulations of monomers indicate that both WT and the A117V mutated PrP113-120 are mostly random coils with helical structures transiently populated. Differently, the A117V mutation enhances the intrinsic disorder of PrP113-120. The simulations of 2- and 4-peptide systems of the two species show that the A117V mutation increases the sheet contents and the populations of oligomers, which may be attributed to the enhancement of inter-peptide backbone hydrogen bonding interactions and side chain hydrophobic interactions. Overall, the study provides structural insights into the impacts of the A117V mutation on the folding and assembly of the palindromic sequences, which might be helpful to elucidate the mechanism underlying prion disease and the origin of the Gerstmann-Straussler-Scheinker Syndrome.

Automated structure and flow measurement - a promising tool in nailfold capillaroscopy.

PubMed

Berks, Michael; Dinsdale, Graham; Murray, Andrea; Moore, Tonia; Manning, Joanne; Taylor, Chris; Herrick, Ariane L

2018-07-01

Despite increasing interest in nailfold capillaroscopy, objective measures of capillary structure and blood flow have been little studied. We aimed to test the hypothesis that structural measurements, capillary flow, and a combined measure have the predictive power to separate patients with systemic sclerosis (SSc) from those with primary Raynaud's phenomenon (PRP) and healthy controls (HC). 50 patients with SSc, 12 with PRP, and 50 HC were imaged using a novel capillaroscopy system that generates high-quality nailfold images and provides fully-automated measurements of capillary structure and blood flow (capillary density, mean width, maximum width, shape score, derangement and mean flow velocity). Population statistics summarise the differences between the three groups. Areas under ROC curves (A Z ) were used to measure classification accuracy when assigning individuals to SSc and HC/PRP groups. Statistically significant differences in group means were found between patients with SSc and both HC and patients with PRP, for all measurements, e.g. mean width (μm) ± SE: 15.0 ± 0.71, 12.7 ± 0.74 and 11.8 ± 0.23 for SSc, PRP and HC respectively. Combining the five structural measurements gave better classification (A Z  = 0.919 ± 0.026) than the best single measurement (mean width, A Z  = 0.874 ± 0.043), whilst adding flow further improved classification (A Z  = 0.930 ± 0.024). Structural and blood flow measurements are both able to distinguish patients with SSc from those with PRP/HC. Importantly, these hold promise as clinical trial outcome measures for treatments aimed at improving finger blood flow or microvascular remodelling. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Prion protein modulates glucose homeostasis by altering intracellular iron.

PubMed

Ashok, Ajay; Singh, Neena

2018-04-26

The prion protein (PrP C ), a mainly neuronal protein, is known to modulate glucose homeostasis in mouse models. We explored the underlying mechanism in mouse models and the human pancreatic β-cell line 1.1B4. We report expression of PrP C on mouse pancreatic β-cells, where it promoted uptake of iron through divalent-metal-transporters. Accordingly, pancreatic iron stores in PrP knockout mice (PrP -/- ) were significantly lower than wild type (PrP +/+ ) controls. Silencing of PrP C in 1.1B4 cells resulted in significant depletion of intracellular (IC) iron, and remarkably, upregulation of glucose transporter GLUT2 and insulin. Iron overloading, on the other hand, resulted in downregulation of GLUT2 and insulin in a PrP C -dependent manner. Similar observations were noted in the brain, liver, and neuroretina of iron overloaded PrP +/+ but not PrP -/- mice, indicating PrP C -mediated modulation of insulin and glucose homeostasis through iron. Peripheral challenge with glucose and insulin revealed blunting of the response in iron-overloaded PrP +/+ relative to PrP -/- mice, suggesting that PrP C -mediated modulation of IC iron influences both secretion and sensitivity of peripheral organs to insulin. These observations have implications for Alzheimer's disease and diabetic retinopathy, known complications of type-2-diabetes associated with brain and ocular iron-dyshomeostasis.

Close Vicinity of PrP Expressing Cells (FDC) with Noradrenergic Fibers in Healthy Sheep Spleen

PubMed Central

Lezmi, S.; Hunsmann, G.; Baron, T.

2001-01-01

In naturally and experimentally occurring scrapie in sheep, prions invade the immune system and replicate in lymphoid organs. Here we analysed immunohistochemically, in seven spleens of 6-month-old healthy sheep, the nature of the cells expressing prion protein (PrP) potentially supporting prion replication, as well as their relationship with autonomic innervation. PrP was identified using either RB1 rabbit antiserum or 4F2 monoclonal antibody directed against AA 108–123 portion of the bovine and AA 79–92 of human prion protein respectively. Using double labelling analysis, we demonstrated that PrPc is expressed by follicular dendritic cells using a specific monoclonal antibody (CNA42). We also showed the close vicinity of these PrP expressing cells with noradrenergic fibers, using a polyclonal tyrosine hydroxylase antibody. Our results may help the study of the cellular requirements for the possible neuroinvasion from the spleen. PMID:11785673

Comparison of the Efficacy of Homologous and Autologous Platelet-Rich Plasma (PRP) for Treating Androgenic Alopecia.

PubMed

Ince, Bilsev; Yildirim, Mehmet Emin Cem; Dadaci, Mehmet; Avunduk, Mustafa Cihat; Savaci, Nedim

2018-02-01

Androgenetic alopecia (AGA), the most common cause of hair loss in both sexes, accounts for 95% of all cases of hair loss. Although the literature has suggested that both nonactivated (n-PRP) and activated autologous (a-PRP) PRP can be used to treat AGA, we did not find any study investigating the use of homologous PRP (h-PRP) for this purpose. Also, to the best of our knowledge, there are no studies comparing the efficacy of h-PRP, a-PRP, or n-PRP on AGA therapy. The aim of this study was to compare the increase in hair density, average number of platelets, complications, preparation, and duration of application in the treatment of AGA using a-PRP, n-PRP, and h-PRP. Between 2014 and 2015, we studied male patients who had experienced increased hair loss in the last year. Patients were divided into three groups: Group 1 received n-PRP, Group 2 received active PRP, and Group 3 received h-PRP. For Group 1, PRP was prepared by a single centrifugation prepared from the patient's own blood. For Group 2, the PRP was prepared from the patient's own blood, but a second centrifugation was applied for platelet activation with calcium chloride. For Group 3, the PRP was prepared from pooled platelets with the same blood group as the patient from the blood center. PRP was injected at 1, 2, and 6 months. The hair density (n/cm 2 ) of each patient before and after injection was calculated. Each patient was assigned a fixed evaluation point at the time of application to calculate hair density. At 2, 6, and 12 months after the first treatment, the increase in hair density was calculated as 11.2, 26.1, and 32.4%, respectively, in Group 1; 8.1, 12.5, and 20.8%, respectively, in Group 2; and 16.09, 36.41, and 41.76%, respectively, in Group 3. The increase in hair density was statistically significantly greater in Group 1 than in Group 2 and more so in Group 3 than in both groups among all controls (p < 0.05). The efficacy of both PRPs was determined in AGA treatment in our study. However, it was determined statistically that the increase in hair density with h-PRP was greater than with autologous PRP groups. We believe that h-PRP therapy can be used in patients with AGA presenting with hair loss. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The positive effects of different platelet-rich plasma methods on human muscle, bone, and tendon cells.

PubMed

Mazzocca, Augustus D; McCarthy, Mary Beth R; Chowaniec, David M; Dugdale, Evan M; Hansen, Derek; Cote, Mark P; Bradley, James P; Romeo, Anthony A; Arciero, Robert A; Beitzel, Knut

2012-08-01

Clinical application of platelet-rich plasma (PRP) in the realm of orthopaedic sports medicine has yielded variable results. Differences in separation methods and variability of the individual may contribute to these variable results. To compare the effects of different PRP separation methods on human bone, muscle, and tendon cells in an in vitro model. Controlled laboratory study. Blood collected from 8 participants (mean ± SD age 31.6 ± 10.9 years) was used to obtain PRP preparations. Three different PRP separation methods were used: a single-spin process yielding a lower platelet concentration (PRP(LP)), a single-spin process yielding high platelet and white blood cell concentrations (PRP(HP)), and a double-spin that produces a higher platelet concentration and lower white blood cell concentration (PRP(DS)). Human bone, muscle, and tendon cells obtained from discarded tissue samples during shoulder surgery were placed into culture and treated with the 3 PRP preparations, control media (2% fetal bovine serum [FBS] and 10% FBS), and native blood. Radioactive thymidine assays were obtained to examine cell proliferation, and testing with enzyme-linked immunosorbent assay was used to determine growth factor concentrations. Addition of PRP(LP) to osteocytes, myocytes, and tenocytes significantly increased cell proliferation (P ≤ .05) compared with the controls. Adding PRP(DS) to osteoblasts and tenocytes increased cell proliferation significantly (P ≤ .05), but no significance was shown for its addition to myocytes. The addition of PRP(HP) significantly increased cell proliferation compared with the controls only when added to tenocytes (P ≤ .05). Osteoblasts: Proliferation was significantly increased by addition of PRP(LP) compared with all controls (2% FBS, 10% FBS, native blood) (P ≤ .05). Addition of PRP(DS) led to significantly increased proliferation compared with all controls, native blood, and PRP(HP) (P ≤ .05). Proliferation was significantly less when PRP(HP) was added compared with PRP(DS) (P ≤ .05). Myocytes: Proliferation was significantly increased by addition of PRP(LP) compared with native blood (P ≤ .05). Adding PRP(HP) or PRP(DS) to myocytes showed no significant increase in proliferation compared with the controls or the other separations. Tenocytes: Proliferation was significantly increased by addition of PRP(LP) compared with all controls (2% FBS, 10% FBS, native blood) (P ≤ .05). Addition of PRP(DS) showed a significant increase compared with the controls and native blood. For tenocytes, there was a significant increase (P ≤ .05) seen when PRP(HP) was added compared with the controls and native blood but not compared with the other separations. The primary findings of this study suggest the application of different PRP separations may result in a potential beneficial effect on the clinically relevant target cells in vitro. However, it is unclear which platelet concentration or PRP preparation may be optimal for the treatment of various cell types. In addition, a "more is better" theory for the use of higher platelet concentrations cannot be supported. This study was not intended to prove efficacy but to provide a platform for future research to be built upon. The utilization of different PRP separations may result in a potentially beneficial effect on the clinically relevant target cells in vitro, but it is unclear which platelet concentration or PRP preparation may be optimal for the treatment of various cell types.

Prion Protein Devoid of the Octapeptide Repeat Region Delays Bovine Spongiform Encephalopathy Pathogenesis in Mice.

PubMed

Hara, Hideyuki; Miyata, Hironori; Das, Nandita Rani; Chida, Junji; Yoshimochi, Tatenobu; Uchiyama, Keiji; Watanabe, Hitomi; Kondoh, Gen; Yokoyama, Takashi; Sakaguchi, Suehiro

2018-01-01

Conformational conversion of the cellular isoform of prion protein, PrP C , into the abnormally folded, amyloidogenic isoform, PrP Sc , is a key pathogenic event in prion diseases, including Creutzfeldt-Jakob disease in humans and scrapie and bovine spongiform encephalopathy (BSE) in animals. We previously reported that the octapeptide repeat (OR) region could be dispensable for converting PrP C into PrP Sc after infection with RML prions. We demonstrated that mice transgenically expressing mouse PrP with deletion of the OR region on the PrP knockout background, designated Tg(PrPΔOR)/ Prnp 0 / 0 mice, did not show reduced susceptibility to RML scrapie prions, with abundant accumulation of PrP Sc ΔOR in their brains. We show here that Tg(PrPΔOR)/ Prnp 0 / 0 mice were highly resistant to BSE prions, developing the disease with markedly elongated incubation times after infection with BSE prions. The conversion of PrPΔOR into PrP Sc ΔOR was markedly delayed in their brains. These results suggest that the OR region may have a crucial role in the conversion of PrP C into PrP Sc after infection with BSE prions. However, Tg(PrPΔOR)/ Prnp 0 / 0 mice remained susceptible to RML and 22L scrapie prions, developing the disease without elongated incubation times after infection with RML and 22L prions. PrP Sc ΔOR accumulated only slightly less in the brains of RML- or 22L-infected Tg(PrPΔOR)/ Prnp 0 / 0 mice than PrP Sc in control wild-type mice. Taken together, these results indicate that the OR region of PrP C could play a differential role in the pathogenesis of BSE prions and RML or 22L scrapie prions. IMPORTANCE Structure-function relationship studies of PrP C conformational conversion into PrP Sc are worthwhile to understand the mechanism of the conversion of PrP C into PrP Sc We show here that, by inoculating Tg(PrPΔOR)/ Prnp 0 / 0 mice with the three different strains of RML, 22L, and BSE prions, the OR region could play a differential role in the conversion of PrP C into PrP Sc after infection with RML or 22L scrapie prions and BSE prions. PrPΔOR was efficiently converted into PrP Sc ΔOR after infection with RML and 22L prions. However, the conversion of PrPΔOR into PrP Sc ΔOR was markedly delayed after infection with BSE prions. Further investigation into the role of the OR region in the conversion of PrP C into PrP Sc after infection with BSE prions might be helpful for understanding the pathogenesis of BSE prions. Copyright © 2017 American Society for Microbiology.

Idiopathic Brainstem Neuronal Chromatolysis (IBNC): a novel prion protein related disorder of cattle?

PubMed Central

Jeffrey, Martin; Perez, Belinda Baquero; Martin, Stuart; Terry, Linda; González, Lorenzo

2008-01-01

Background The epidemic form of Bovine Spongiform Encephalopathy (BSE) is generally considered to have been caused by a single prion strain but at least two strain variants of cattle prion disorders have recently been recognized. An additional neurodegenerative condition, idiopathic brainstem neuronal chromatolysis and hippocampal sclerosis (IBNC), a rare neurological disease of adult cattle, was also recognised in a sub-set of cattle submitted under the BSE Orders in which lesions of BSE were absent. Between the years of 1988 and 1991 IBNC occurred in Scotland with an incidence of 7 cases per 100,000 beef suckler cows over the age of 6 years. Results When the brains of 15 IBNC cases were each tested by immunohistochemistry, all showed abnormal labelling for prion protein (PrP). Immunohistological labelling for PrP was also present in the retina of a single case available for examination. The pattern of PrP labelling in brain is distinct from that seen in other ruminant prion diseases and is absent from brains with other inflammatory conditions and from normal control brains. Brains of IBNC cattle do not reveal abnormal PrP isoforms when tested by the commercial BioRad or Idexx test kits and do not reveal PrPres when tested by Western blotting using stringent proteinase digestion methods. However, some weakly protease resistant isoforms of PrP may be detected when tissues are examined using mild proteinase digestion techniques. Conclusion The study shows that a distinctive neurological disorder of cattle, which has some clinical similarities to BSE, is associated with abnormal PrP labelling in brain but the pathology and biochemistry of IBNC are distinct from BSE. The study is important either because it raises the possibility of a significant increase in the scope of prion disease or because it demonstrates that widespread and consistent PrP alterations may not be confined to prion diseases. Further studies, including transmission experiments, are needed to establish whether IBNC is a condition in which prion protein is abnormally regulated or it is yet a further example of an infectious cattle prion disease. PMID:18826563

Implicit hype? Representations of platelet rich plasma in the news media.

PubMed

Rachul, Christen; Rasko, John E J; Caulfield, Timothy

2017-01-01

Platelet Rich Plasma (PRP) has gained popularity in recent years for treating sports-related injuries and the news media frequently reports on elite athletes' and celebrities' use of PRP. We conducted a content analysis of newspaper coverage of PRP in Australia, Canada, Ireland, New Zealand, United Kingdom, and the United States. Findings show that news media coverage of PRP appears most frequently in sports-related stories, and in relation to elite athletes use of PRP. PRP injections are largely portrayed as a routine treatment for sports-related injuries and newspaper articles rarely discuss the limitations or efficacy of PRP. We argue that while news media coverage of PRP exhibits very few common hallmarks of hype, its portrayal as a routine treatment used by elite athletes and celebrities creates an implicit hype. This implicit hype can contribute to public misunderstandings of the efficacy of PRP.

Implicit hype? Representations of platelet rich plasma in the news media

PubMed Central

2017-01-01

Platelet Rich Plasma (PRP) has gained popularity in recent years for treating sports-related injuries and the news media frequently reports on elite athletes’ and celebrities’ use of PRP. We conducted a content analysis of newspaper coverage of PRP in Australia, Canada, Ireland, New Zealand, United Kingdom, and the United States. Findings show that news media coverage of PRP appears most frequently in sports-related stories, and in relation to elite athletes use of PRP. PRP injections are largely portrayed as a routine treatment for sports-related injuries and newspaper articles rarely discuss the limitations or efficacy of PRP. We argue that while news media coverage of PRP exhibits very few common hallmarks of hype, its portrayal as a routine treatment used by elite athletes and celebrities creates an implicit hype. This implicit hype can contribute to public misunderstandings of the efficacy of PRP. PMID:28792974

Platelet-Rich Plasma Promotes Axon Regeneration, Wound Healing, and Pain Reduction: Fact or Fiction.

PubMed

Kuffler, Damien P

2015-10-01

Platelet-rich plasma (PRP) has been tested in vitro, in animal models, and clinically for its efficacy in enhancing the rate of wound healing, reducing pain associated with injuries, and promoting axon regeneration. Although extensive data indicate that PRP-released factors induce these effects, the claims are often weakened because many studies were not rigorous or controlled, the data were limited, and other studies yielded contrary results. Critical to assessing whether PRP is effective are the large number of variables in these studies, including the method of PRP preparation, which influences the composition of PRP; type of application; type of wounds; target tissues; and diverse animal models and clinical studies. All these variables raise the question of whether one can anticipate consistent influences and raise the possibility that most of the results are correct under the circumstances where PRP was tested. This review examines evidence on the potential influences of PRP and whether PRP-released factors could induce the reported influences and concludes that the preponderance of evidence suggests that PRP has the capacity to induce all the claimed influences, although this position cannot be definitively argued. Well-defined and rigorously controlled studies of the potential influences of PRP are required in which PRP is isolated and applied using consistent techniques, protocols, and models. Finally, it is concluded that, because of the purported benefits of PRP administration and the lack of adverse events, further animal and clinical studies should be performed to explore the potential influences of PRP.

Ranibizumab Plus Panretinal Photocoagulation versus Panretinal Photocoagulation Alone for High-Risk Proliferative Diabetic Retinopathy (PROTEUS Study).

PubMed

Figueira, João; Fletcher, Emily; Massin, Pascale; Silva, Rufino; Bandello, Francesco; Midena, Edoardo; Varano, Monica; Sivaprasad, Sobha; Eleftheriadis, Haralabos; Menon, Geeta; Amaro, Miguel; Ayello Scheer, Sarah; Creuzot-Garcher, Catherine; Nascimento, João; Alves, Dalila; Nunes, Sandrina; Lobo, Conceição; Cunha-Vaz, José

2018-05-01

Comparison of the efficacy of ranibizumab (RBZ) 0.5 mg intravitreal injections plus panretinal photocoagulation (PRP) versus PRP alone in the regression of the neovascularization (NV) area in subjects with high-risk proliferative diabetic retinopathy (HR-PDR) over a 12-month period. Prospective, randomized, multicenter, open-label, phase II/III study. Eighty-seven participants (aged ≥18 years) with type 1/2 diabetes and HR-PDR (mean age, 55.2 years; 37% were female). Participants were randomized (1:1) to receive RBZ+PRP (n = 41) or PRP monotherapy (n = 46). The RBZ+PRP group received 3 monthly RBZ injections along with standard PRP. The PRP monotherapy group received standard PRP between day 1 and month 2; thereafter, re-treatments in both groups were at the investigators' discretion. The primary outcome was regression of NV total, on the disc (NVD) plus elsewhere (NVE), defined as any decrease in the area of NV from the baseline to month 12. Secondary outcomes included best-corrected visual acuity (BCVA) changes from baseline to month 12, time to complete NV regression, recurrence of NV, macular retinal thickness changes from baseline to month 12, need for treatment for diabetic macular edema, need for vitrectomy because of occurrence of vitreous hemorrhage, tractional retinal detachment or other complications of DR, and adverse events (AEs) related to treatments. Seventy-seven participants (88.5%) completed the study. Overall baseline demographics were similar for both groups, except for age. At month 12, 92.7% of participants in the RBZ+PRP group presented NV total reduction versus 70.5% of the PRP monotherapy participants (P = 0.009). The number of participants with NVD and NVE reductions was higher with RBZ+PRP (93.3% and 91.4%, respectively) versus PRP (68.8% and 73.7%, respectively), significant only for NVE (P = 0.048). Complete NV total regression was observed in 43.9% in the RBZ+PRP group versus 25.0% in the PRP monotherapy group (P = 0.066). At month 12, the mean BCVA was 75.2 letters (20/32) in the RBZ+PRP group versus 69.2 letters (20/40) in the PRP monotherapy group (P = 0.104). In the RBZ+PRP group, the mean number of PRP treatments over month 12 was 3.5±1.3, whereas in the PRP monotherapy group, it was 4.6±1.5 (P = 0.001). No deaths or unexpected AEs were reported. Treatment with RBZ+PRP was more effective than PRP monotherapy for NV regression in HR-PDR participants over 12 months. Copyright © 2018 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Effects of Platelet-Rich Plasma With Concomitant Use of a Corticosteroid on Tenocytes From Degenerative Rotator Cuff Tears in Interleukin 1β-Induced Tendinopathic Conditions.

PubMed

Jo, Chris Hyunchul; Lee, Seung Yeon; Yoon, Kang Sup; Shin, Sue

2017-04-01

A corticosteroid injection is commonly used to treat tendinopathy, but it has been associated with negative effects on tendon homeostasis. Platelet-rich plasma (PRP) is known to have proliferative and anabolic effects as well as cytoprotective effects against corticosteroids on tenocytes. However, the combined effects of a corticosteroid and PRP on the anti-inflammatory, matrix synthesis, and cytoprotective potential of tenocytes in conditions simulating tendinopathy have not been investigated. To assess the effects of PRP on tenocytes from degenerative rotator cuff tears with the concomitant use of a corticosteroid in interleukin 1β (IL-1β)-induced tendinopathic conditions. Controlled laboratory study. Tenocytes were enzymatically isolated and cultured from patients with degenerative rotator cuff tears. PRP was prepared using a plateletpheresis system, and growth factor concentrations were measured. To evaluate the gene expression of proinflammatory and anti-inflammatory cytokines, enzymes and their inhibitors, and matrix molecules, cells were cultured with 1 ng/mL IL-1β, 1 μM dexamethasone, and 10% (vol/vol) platelet-poor plasma (PPP) and PRP of 200, 1000, and 4000 × 10 3 /μL; quantitative real-time reverse transcriptase polymerase chain reaction was also performed. Western blotting was performed to investigate the protein synthesis of degradative enzymes and their inhibitors. Cell viability, apoptosis, and senescence assays were also conducted. PRP did not interfere with the anti-inflammatory effects of dexamethasone on tenocytes pretreated with IL-1β, but it increased the synthesis of tissue inhibitor of metalloproteinase (TIMP)-1 and -3. Meanwhile, PRP did not induce anti-inflammatory cytokines that had been suppressed with a corticosteroid. It did increase the type I/III collagen ratio mainly through the suppression of type III collagen expression. PRP reversed the decreased viability, increased apoptosis, and induced senescence with IL-1β and a corticosteroid. This study shows that the addition of PRP does not interfere with the anti-inflammatory effects of a corticosteroid on IL-1β-treated tenocytes from degenerative rotator cuff tears but that it does avoid the deleterious side effects of a corticosteroid. PRP can be clinically useful with a corticosteroid as a treatment for tendinopathy.

Effects of Calcium Sulfate Combined with Platelet-rich Plasma on Restoration of Long Bone Defect in Rabbits

PubMed Central

Chen, Hua; Ji, Xin-Ran; Zhang, Qun; Tian, Xue-Zhong; Zhang, Bo-Xun; Tang, Pei-Fu

2016-01-01

Background: The treatment for long bone defects has been a hot topic in the field of regenerative medicine. This study aimed to evaluate the therapeutic effects of calcium sulfate (CS) combined with platelet-rich plasma (PRP) on long bone defect restoration. Methods: A radial bone defect model was constructed through an osteotomy using New Zealand rabbits. The rabbits were randomly divided into four groups (n = 10 in each group): a CS combined with PRP (CS-PRP) group, a CS group, a PRP group, and a positive (recombinant human bone morphogenetic protein-2) control group. PRP was prepared from autologous blood using a two-step centrifugation process. CS-PRP was obtained by mixing hemihydrate CS with PRP. Radiographs and histologic micrographs were generated. The percentage of bone regenerated bone area in each rabbit was calculated at 10 weeks. One-way analysis of variance was performed in this study. Results: The radiographs and histologic micrographs showed bone restoration in the CS-PRP and positive control groups, while nonunion was observed in the CS and PRP groups. The percentages of bone regenerated bone area in the CS-PRP (84.60 ± 2.87%) and positive control (52.21 ± 4.53%) groups were significantly greater than those in the CS group (12.34 ± 2.17%) and PRP group (16.52 ± 4.22%) (P < 0.001). In addition, the bone strength of CS-PRP group (43.10 ± 4.10%) was significantly greater than that of the CS group (20.10 ± 3.70%) or PRP group (25.10 ± 2.10%) (P < 0.001). Conclusion: CS-PRP functions as an effective treatment for long bone defects through stimulating bone regeneration and enhancing new bone strength. PMID:26904990

Pain responses of Pascal 20 ms multi-spot and 100 ms single-spot panretinal photocoagulation: Manchester Pascal Study, MAPASS report 2.

PubMed

Muqit, M M K; Marcellino, G R; Gray, J C B; McLauchlan, R; Henson, D B; Young, L B; Patton, N; Charles, S J; Turner, G S; Stanga, P E

2010-11-01

To evaluate pain responses following Pascal 20 ms multi-spot and 100 ms single-spot panretinal photocoagulation (PRP). Single-centre randomised clinical trial. 40 eyes of 24 patients with treatment-naive proliferative diabetic retinopathy randomised to 20 and 100 ms PRP under topical 0.4% oxybuprocaine. A masked grader used a pain questionnaire within 1 h (numerical pain score (NPS)) and 1 month after treatment (numerical headache score (NHS)). Primary outcome measure was NPS immediately post-PRP. Secondary outcome measures were mean NHS scores and levels of photophobia reported within 4 weeks of primary PRP. Mean laser fluence was significantly lower using 20 ms PRP (4.8 J/cm²) compared to 100 ms PRP (11.8 J/cm²); p < 0.001). Mean NPS scores for treatment were 2.4 (2.3) (mild) for 20 ms PRP group compared to 4.9 (3.3) (moderate) in 100 ms PRP group-a significant difference (95% CI 4.3 to 0.68; p = 0.006). Mean NHS score within 1 month was 1.5 (2.7) in 20 ms PRP group compared to 3.2 (3.5) in the 100 ms PRP group (p < 0.05). The median duration of photophobia after 20 ms PRP was 3 h, and significantly less compared to 100 ms PRP after which 72 h of photophobia was reported (p < 0.001). Multi-spot 20 ms PRP was associated with significantly lower levels of anxiety, headache, pain and photophobia compared to 100 ms single-spot PRP treatment. Possible reasons include lower fluence, shorter-pulse duration, and spatial summation of laser nociception with multi-spot Pascal technique.

Positive effect of an autologous platelet concentrate in lateral epicondylitis in a double-blind randomized controlled trial: platelet-rich plasma versus corticosteroid injection with a 1-year follow-up.

PubMed

Peerbooms, Joost C; Sluimer, Jordi; Bruijn, Daniël J; Gosens, Taco

2010-02-01

Platelet-rich plasma (PRP) has shown to be a general stimulation for repair. Purpose To determine the effectiveness of PRP compared with corticosteroid injections in patients with chronic lateral epicondylitis. Randomized controlled trial; Level of evidence, 1. The trial was conducted in 2 teaching hospitals in the Netherlands. One hundred patients with chronic lateral epicondylitis were randomly assigned in the PRP group (n = 51) or the corticosteroid group (n = 49). A central computer system carried out randomization and allocation to the trial group. Patients were randomized to receive either a corticosteroid injection or an autologous platelet concentrate injection through a peppering technique. The primary analysis included visual analog scores and DASH Outcome Measure scores (DASH: Disabilities of the Arm, Shoulder, and Hand). Successful treatment was defined as more than a 25% reduction in visual analog score or DASH score without a reintervention after 1 year. The results showed that, according to the visual analog scores, 24 of the 49 patients (49%) in the corticosteroid group and 37 of the 51 patients (73%) in the PRP group were successful, which was significantly different (P <.001). Furthermore, according to the DASH scores, 25 of the 49 patients (51%) in the corticosteroid group and 37 of the 51 patients (73%) in the PRP group were successful, which was also significantly different (P = .005). The corticosteroid group was better initially and then declined, whereas the PRP group progressively improved. Treatment of patients with chronic lateral epicondylitis with PRP reduces pain and significantly increases function, exceeding the effect of corticosteroid injection. Future decisions for application of the PRP for lateral epicondylitis should be confirmed by further follow-up from this trial and should take into account possible costs and harms as well as benefits.

Antiplatelet Agents Can Promote Two-Peaked Thrombin Generation in Platelet Rich Plasma: Mechanism and Possible Applications

PubMed Central

Tarandovskiy, Ivan D.; Artemenko, Elena O.; Panteleev, Mikhail A.; Sinauridze, Elena I.; Ataullakhanov, Fazoil I.

2013-01-01

Background Thrombin generation assay is a convenient and widely used method for analysis of the blood coagulation system status. Thrombin generation curve (TGC) is usually bell-shaped with a single peak, but there are exceptions. In particular, TGC in platelet-rich plasma (PRP) can sometimes have two peaks. Objective We sought to understand the mechanism underlying the occurrence of two peaks in the PRP thrombin generation curve. Methods Tissue factor-induced thrombin generation in PRP and platelet-poor plasma (PPP) was monitored using continuous measurement of the hydrolysis rate of the thrombin-specific fluorogenic substrate Z-Gly-Gly-Arg-AMC. Expression of phosphatidylserine (PS) and CD62P on the surface of activated platelets was measured by flow cytometry using corresponding fluorescently labeled markers. Results The addition of the P2Y12 receptor antagonist MeS-AMP (160 µM), 83 nM prostaglandin E1 (PGE1), or 1.6% DMSO to PRP caused the appearance of two peaks in the TGC. The PS exposure after thrombin activation on washed platelets in a suspension supplemented with DMSO, PGE1 or MeS-AMP was delayed, which could indicate mechanism of the second peak formation. Supplementation of PRP with 1.6% DMSO plus 830 nM PGE1 mediated the disappearance of the second peak and decreased the amplitude of the first peak. Increasing the platelet concentration in the PRP promoted the consolidation of the two peaks into one. Conclusions Procoagulant tenase and prothrombinase complexes in PRP assemble on phospholipid surfaces containing PS of two types - plasma lipoproteins and the surface of activated platelets. Thrombin generation in the PRP can be two-peaked. The second peak appears in the presence of platelet antagonists as a result of delayed PS expression on platelets, which leads to delayed assembly of the membrane-dependent procoagulant complexes and a second wave of thrombin generation. PMID:23405196

Ongoing positive effect of platelet-rich plasma versus corticosteroid injection in lateral epicondylitis: a double-blind randomized controlled trial with 2-year follow-up.

PubMed

Gosens, Taco; Peerbooms, Joost C; van Laar, Wilbert; den Oudsten, Brenda L

2011-06-01

Platelet-rich plasma (PRP) has been shown to be a general stimulation for repair and 1-year results showed promising success percentages. This trial was undertaken to determine the effectiveness of PRP compared with corticosteroid injections in patients with chronic lateral epicondylitis with a 2-year follow-up. Randomized controlled trial; Level of evidence, 1. The trial was conducted in 2 Dutch teaching hospitals. One hundred patients with chronic lateral epicondylitis were randomly assigned to a leukocyte-enriched PRP group (n = 51) or the corticosteroid group (n = 49). Randomization and allocation to the trial group were carried out by a central computer system. Patients received either a corticosteroid injection or an autologous platelet concentrate injection through a peppering needling technique. The primary analysis included visual analog scale (VAS) pain scores and Disabilities of the Arm, Shoulder and Hand (DASH) outcome scores. The PRP group was more often successfully treated than the corticosteroid group (P < .0001). Success was defined as a reduction of 25% on VAS or DASH scores without a reintervention after 2 years. When baseline VAS and DASH scores were compared with the scores at 2-year follow-up, both groups significantly improved across time (intention-to-treat principle). However, the DASH scores of the corticosteroid group returned to baseline levels, while those of the PRP group significantly improved (as-treated principle). There were no complications related to the use of PRP. Treatment of patients with chronic lateral epicondylitis with PRP reduces pain and increases function significantly, exceeding the effect of corticosteroid injection even after a follow-up of 2 years. Future decisions for application of PRP for lateral epicondylitis should be confirmed by further follow-up from this trial and should take into account possible costs and harms as well as benefits.

The effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative peritoneal adhesion formation in rats.

PubMed

Makarchian, Hamid Reza; Kasraianfard, Amir; Ghaderzadeh, Pezhman; Javadi, Seyed Mohammad Reza; Ghorbanpoor, Manoochehr

2017-01-01

To assess the effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative adhesion in animal models. Sixty males Albino Wistar rats aged 5 to 6 weeks were classified into five groups receiving none, heparin, PRP, silver nanoparticles, PRP plus silver nanoparticles intraperitoneally. After 2 weeks, the animals underwent laparotomy and the damaged site was assessed for peritoneal adhesions severity. The mean severity scores were 2.5 ± 0.9, 2.16 ± 0.7, 1.5 ± 0.5, 2.66 ± 0.88, and 2.25 ± 0.62 in the control, heparin, PRP, silver and PRP plus silver groups, respectively with significant intergroup difference (p = 0.004). The highest effective material for preventing adhesion formation was PRP followed by heparin and PRP plus silver. Moreover, compared to the controls, only use of PRP was significantly effective, in terms of adhesion severity (p = 0.01) . Platelet-rich plasma alone may have the highest efficacy for preventing postoperative peritoneal adhesions in comparison with heparin, silver nanoparticles and PRP plus silver nanoparticles.

DNA damage induces down-regulation of Prp19 via impairing Prp19 stability in hepatocellular carcinoma cells.

PubMed

Yin, Jie; Zhang, Yi-An; Liu, Tao-Tao; Zhu, Ji-Min; Shen, Xi-Zhong

2014-01-01

Pre-mRNA processing factor 19 (Prp19) activates pre-mRNA spliceosome and also mediates DNA damage response. Prp19 overexpression in cells with functional p53 leads to decreased apoptosis and increases cell survival after DNA damage. Here we showed that in hepatocellular carcinoma (HCC) cells with inactive p53 or functional p53, Prp19 was down-regulated due to the impaired stability under chemotherapeutic drug treatment. Silencing Prp19 expression enhanced apoptosis of HCC cells with or without chemotherapeutic drug treatment. Furthermore high level of Prp19 may inhibit chemotherapeutic drugs induced apoptosis in hepatocellular carcinoma cells through modulating myeloid leukemia cell differentiation 1 expression. These results indicated that targeting Prp19 may potentiate pro-apoptotic effect of chemotherapeutic agents on HCC.

Peer norm guesses and self-reported attitudes towards performance-related pay.

PubMed

Georgantzis, Nikolaos; Vasileiou, Efi; Kotzaivazoglou, Iordanis

2017-01-01

Due to a variety of reasons, people see themselves differently from how they see others. This basic asymmetry has broad consequences. It leads people to judge themselves and their own behavior differently from how they judge others and others' behavior. This research, first, studies the perceptions and attitudes of Greek Public Sector employees towards the introduction of Performance-Related Pay (PRP) systems trying to reveal whether there is a divergence between individual attitudes and guesses on peers' attitudes. Secondly, it is investigated whether divergence between own self-reported and peer norm guesses could mediate the acceptance of the aforementioned implementation once job status has been controlled for. This study uses a unique questionnaire of 520 observations which was designed to address the questions outlined in the preceding lines. Our econometric results indicate that workers have heterogeneous attitudes and hold heterogeneous beliefs on others' expectations regarding a successful implementation of PRP. Specifically, individual perceptions are less skeptical towards PRP than are beliefs on others' attitudes. Additionally, we found that managers are significantly more optimistic than lower rank employees regarding the expected success of PRP systems in their jobs. However, they both expect their peers to be more negative than they themselves are.

Peer norm guesses and self-reported attitudes towards performance-related pay

PubMed Central

Vasileiou, Efi; Kotzaivazoglou, Iordanis

2017-01-01

Due to a variety of reasons, people see themselves differently from how they see others. This basic asymmetry has broad consequences. It leads people to judge themselves and their own behavior differently from how they judge others and others’ behavior. This research, first, studies the perceptions and attitudes of Greek Public Sector employees towards the introduction of Performance-Related Pay (PRP) systems trying to reveal whether there is a divergence between individual attitudes and guesses on peers’ attitudes. Secondly, it is investigated whether divergence between own self-reported and peer norm guesses could mediate the acceptance of the aforementioned implementation once job status has been controlled for. This study uses a unique questionnaire of 520 observations which was designed to address the questions outlined in the preceding lines. Our econometric results indicate that workers have heterogeneous attitudes and hold heterogeneous beliefs on others’ expectations regarding a successful implementation of PRP. Specifically, individual perceptions are less skeptical towards PRP than are beliefs on others’ attitudes. Additionally, we found that managers are significantly more optimistic than lower rank employees regarding the expected success of PRP systems in their jobs. However, they both expect their peers to be more negative than they themselves are. PMID:28414737

Platelet-Rich Plasma Preparation Types Show Impact on Chondrogenic Differentiation, Migration, and Proliferation of Human Subchondral Mesenchymal Progenitor Cells.

PubMed

Kreuz, Peter Cornelius; Krüger, Jan Philipp; Metzlaff, Sebastian; Freymann, Undine; Endres, Michaela; Pruss, Axel; Petersen, Wolf; Kaps, Christian

2015-10-01

To evaluate the chondrogenic potential of platelet concentrates on human subchondral mesenchymal progenitor cells (MPCs) as assessed by histomorphometric analysis of proteoglycans and type II collagen. Furthermore, the migratory and proliferative effect of platelet concentrates were assessed. Platelet-rich plasma (PRP) was prepared using preparation kits (Autologous Conditioned Plasma [ACP] Kit [Arthrex, Naples, FL]; Regen ACR-C Kit [Regen Lab, Le Mont-Sur-Lausanne, Switzerland]; and Dr.PRP Kit [Rmedica, Seoul, Republic of Korea]) by apheresis (PRP-A) and by centrifugation (PRP-C). In contrast to clinical application, freeze-and-thaw cycles were subsequently performed to activate platelets and to prevent medium coagulation by residual fibrinogen in vitro. MPCs were harvested from the cortico-spongious bone of femoral heads. Chondrogenic differentiation of MPCs was induced in high-density pellet cultures and evaluated by histochemical staining of typical cartilage matrix components. Migration of MPCs was assessed using a chemotaxis assay, and proliferation activity was measured by DNA content. MPCs cultured in the presence of 5% ACP, Regen, or Dr.PRP formed fibrous tissue, whereas MPCs stimulated with 5% PRP-A or PRP-C developed compact and dense cartilaginous tissue rich in type II collagen and proteoglycans. All platelet concentrates significantly (ACP, P = .00041; Regen, P = .00029; Dr.PRP, P = .00051; PRP-A, P < .0001; and PRP-C, P < .0001) stimulated migration of MPCs. All platelet concentrates but one (Dr.PRP, P = .63) showed a proliferative effect on MPCs, as shown by significant increases (ACP, P = .027; Regen, P = .0029; PRP-A, P = .00021; and PRP-C, P = .00069) in DNA content. Platelet concentrates obtained by different preparation methods exhibit different potentials to stimulate chondrogenic differentiation, migration, and proliferation of MPCs. Platelet concentrates obtained by commercially available preparation kits failed to induce chondrogenic differentiation of MPCs, whereas highly standardized PRP preparations did induce such differentiation. These findings suggest differing outcomes with PRP treatment in stem cell-based cartilage repair. Our findings may help to explain the variability of results in studies examining the use of PRP clinically. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Intradiscal Injection of Autologous Platelet-Rich Plasma Releasate to Treat Discogenic Low Back Pain: A Preliminary Clinical Trial.

PubMed

Akeda, Koji; Ohishi, Kohshi; Masuda, Koichi; Bae, Won C; Takegami, Norihiko; Yamada, Junichi; Nakamura, Tomoki; Sakakibara, Toshihiko; Kasai, Yuichi; Sudo, Akihiro

2017-06-01

Preliminary clinical trial. To determine the safety and initial efficacy of intradiscal injection of autologous platelet-rich plasma (PRP) releasate in patients with discogenic low back pain. PRP, which is comprised of autologous growth factors and cytokines, has been widely used in the clinical setting for tissue regeneration and repair. PRP has been shown in vitro and in vivo to potentially stimulate intervertebral disc matrix metabolism. Inclusion criteria for this study included chronic low back pain without leg pain for more than 3 months; one or more lumbar discs (L3/L4 to L5/S1) with evidence of degeneration, as indicated via magnetic resonance imaging (MRI); and at least one symptomatic disc, confirmed using standardized provocative discography. PRP releasate, isolated from clotted PRP, was injected into the center of the nucleus pulposus. Outcome measures included the use of a visual analog scale (VAS) and the Roland-Morris Disability Questionnaire (RDQ), as well as X-ray and MRI (T2-quantification). Data were analyzed from 14 patients (8 men and 6 women; mean age, 33.8 years). The average follow-up period was 10 months. Following treatment, no patient experienced adverse events or significant narrowing of disc height. The mean pain scores before treatment (VAS, 7.5±1.3; RDQ, 12.6±4.1) were significantly decreased at one month, and this was generally sustained throughout the observation period (6 months after treatment: VAS, 3.2±2.4, RDQ; 3.6±4.5 and 12 months: VAS, 2.9±2.8; RDQ, 2.8±3.9; p <0.01, respectively). The mean T2 values did not significantly change after treatment. We demonstrated that intradiscal injection of autologous PRP releasate in patients with low back pain was safe, with no adverse events observed during follow-up. Future randomized controlled clinical studies should be performed to systematically evaluate the effects of this therapy.

Quantification of platelets and platelet derived growth factors from platelet-rich-plasma (PRP) prepared at different centrifugal force (g) and time.

PubMed

Arora, Satyam; Doda, Veena; Kotwal, Urvershi; Dogra, Mitu

2016-02-01

Platelet derived biomaterials represent a key source of cytokines and growth factors extensively used for tissue regeneration; wound healing and tissue repair. Our study was to quantify platelets and growth factors released by PRP when prepared at different centrifugal force (g) and time. Our study was approved by the institutional ethical committee. One hundred millilitres of whole blood (WB) was collected in bag with CPDA as the anticoagulant(AC); (14 mL for 100 mL WB ratio). Nine aliquots of 10 mL each were made from the bag and set of three aliquots were made a group. PRP was prepared at varying centrifugal force (group A: -110 g, group B: -208 g & group C: -440 g) & time (1: -5 min, 2: -10 min & 3: -20 min). Contents of each PRP prepared were analysed. Commercial sandwich ELISA kits were used to quantify the concentrations of CD62P (Diaclone SAS; France), Platelet derived growth factors-AB (Qayee-Bio; China), transforming growth factor-β1 (DRG; Germany) and vascular endothelial growth factor (Boster Immuno Leader; USA) released in each PRP prepared. Eight volunteers were enrolled in the study (24-30 years). The baseline blood counts of all the volunteers were comparable (p ≥ 0.05). Mean ± SD of platelet yield of all nine groups ranged from 17.2 ± 4.2% to 78.7 ± 5.7%. Each PRP was activated with calcified thromboplastin to quantify the growth factors released by them. Significantly higher (p < 0.05) transforming growth factor-β1 and vascular endothelial growth factor were released compared to the baseline. Our study highlights the variation in both force (g) and time results in changes at cellular level and growth factor concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of 4-week multi-strain probiotic administration on resting-state functional connectivity in healthy volunteers.

PubMed

Bagga, Deepika; Aigner, Christoph Stefan; Reichert, Johanna Louise; Cecchetto, Cinzia; Fischmeister, Florian Ph S; Holzer, Peter; Moissl-Eichinger, Christine; Schöpf, Veronika

2018-05-30

Experimental investigations in rodents have contributed significantly to our current understanding of the potential importance of the gut microbiome and brain interactions for neurotransmitter expression, neurodevelopment, and behaviour. However, clinical evidence to support such interactions is still scarce. The present study used a double-blind, randomized, pre- and post-intervention assessment design to investigate the effects of a 4-week multi-strain probiotic administration on whole-brain functional and structural connectivity in healthy volunteers. Forty-five healthy volunteers were recruited for this study and were divided equally into three groups (PRP: probiotic, PLP: placebo, and CON: control). All the participants underwent resting-state functional MRI and diffusion MRI brain scans twice during the course of study, at the beginning (time point 1) and after 4 weeks (time point 2). MRI data were acquired using a 3T whole-body MR system (Magnetom Skyra, Siemens, Germany). Functional connectivity (FC) changes were observed in the default mode network (DMN), salience network (SN), and middle and superior frontal gyrus network (MFGN) in the PRP group as compared to the PLP and CON groups. PRP group showed a significant decrease in FC in MFGN (in frontal pole and frontal medial cortex) and in DMN (in frontal lobe) as compared to CON and PLP groups, respectively. Further, significant increase in FC in SN (in cingulate gyrus and precuneus cortex) was also observed in PRP group as compared to CON group. The significance threshold was set to p < 0.05 FWE corrected. No significant structural differences were observed between the three groups. This work provides new insights into the role of a multi-strain probiotic administration in modulating the behaviour, which is reflected as changes in the FC in healthy volunteers. This study motivates future investigations into the role of probiotics in context of major depression and stress disorders.

HGF Mediates the Anti-inflammatory Effects of PRP on Injured Tendons

PubMed Central

Zhang, Jianying; Middleton, Kellie K.; Fu, Freddie H.; Im, Hee-Jeong; Wang, James H-C.

2013-01-01

Platelet-rich plasma (PRP) containing hepatocyte growth factor (HGF) and other growth factors are widely used in orthopaedic/sports medicine to repair injured tendons. While PRP treatment is reported to decrease pain in patients with tendon injury, the mechanism of this effect is not clear. Tendon pain is often associated with tendon inflammation, and HGF is known to protect tissues from inflammatory damages. Therefore, we hypothesized that HGF in PRP causes the anti-inflammatory effects. To test this hypothesis, we performed in vitro experiments on rabbit tendon cells and in vivo experiments on a mouse Achilles tendon injury model. We found that addition of PRP or HGF decreased gene expression of COX-1, COX-2, and mPGES-1, induced by the treatment of tendon cells in vitro with IL-1β. Further, the treatment of tendon cell cultures with HGF antibodies reduced the suppressive effects of PRP or HGF on IL-1β-induced COX-1, COX-2, and mPGES-1 gene expressions. Treatment with PRP or HGF almost completely blocked the cellular production of PGE2 and the expression of COX proteins. Finally, injection of PRP or HGF into wounded mouse Achilles tendons in vivo decreased PGE2 production in the tendinous tissues. Injection of platelet-poor plasma (PPP) however, did not reduce PGE2 levels in the wounded tendons, but the injection of HGF antibody inhibited the effects of PRP and HGF. Further, injection of PRP or HGF also decreased COX-1 and COX-2 proteins. These results indicate that PRP exerts anti-inflammatory effects on injured tendons through HGF. This study provides basic scientific evidence to support the use of PRP to treat injured tendons because PRP can reduce inflammation and thereby reduce the associated pain caused by high levels of PGE2. PMID:23840657

Postinjury Exercise and Platelet-Rich Plasma Therapies Improve Skeletal Muscle Healing in Rats But Are Not Synergistic When Combined.

PubMed

Contreras-Muñoz, Paola; Torrella, Joan Ramon; Serres, Xavier; Rizo-Roca, David; De la Varga, Meritxell; Viscor, Ginés; Martínez-Ibáñez, Vicente; Peiró, José Luis; Järvinen, Tero A H; Rodas, Gil; Marotta, Mario

2017-07-01

Skeletal muscle injuries are the most common sports-related injury and a major concern in sports medicine. The effect of platelet-rich plasma (PRP) injections on muscle healing is still poorly understood, and current data are inconclusive. To evaluate the effects of an ultrasound-guided intramuscular PRP injection, administered 24 hours after injury, and/or posttraumatic daily exercise training for 2 weeks on skeletal muscle healing in a recently established rat model of skeletal muscle injury that highly mimics the muscle trauma seen in human athletes. Controlled laboratory study. A total of 40 rats were assigned to 5 groups. Injured rats (medial gastrocnemius injury) received a single PRP injection (PRP group), daily exercise training (Exer group), or a combination of a single PRP injection and daily exercise training (PRP-Exer group). Untreated and intramuscular saline-injected animals were used as controls. Muscle force was determined 2 weeks after muscle injury, and muscles were harvested and evaluated by means of histological assessment and immunofluorescence microscopy. Both PRP (exhibiting 4.8-fold higher platelet concentration than whole blood) and exercise training improved muscle strength (maximum tetanus force, TetF) in approximately 18%, 20%, and 30% of rats in the PRP, PRP-Exer, and Exer groups, respectively. Specific markers of muscle regeneration (developmental myosin heavy chain, dMHC) and scar formation (collagen I) demonstrated the beneficial effect of the tested therapies in accelerating the muscle healing process in rats. PRP and exercise treatments stimulated the growth of newly formed regenerating muscle fibers (1.5-, 2-, and 2.5-fold increase in myofiber cross-sectional area in PRP, PRP-Exer, and Exer groups, respectively) and reduced scar formation in injured skeletal muscle (20%, 34%, and 41% of reduction in PRP, PRP-Exer, and Exer groups, respectively). Exercise-treated muscles (PRP-Exer and Exer groups) had significantly reduced percentage of dMHC-positive regenerating fibers (35% and 47% decrease in dMHC expression, respectively), indicating that exercise therapies accelerated the muscle healing process witnessed by the more rapid replacement of the embryonic-developmental myosin isoform by mature muscle myosin isoforms. Intramuscular PRP injection and, especially, treadmill exercise improve histological outcome and force recovery of the injured skeletal muscle in a rat injury model that imitates sports-related muscle injuries in athletes. However, there was not a synergistic effect when both treatments were combined, suggesting that PRP does not add any beneficial effect to exercise-based therapy in the treatment of injured skeletal muscle. This study demonstrates the efficacy of an early active rehabilitation protocol or single intramuscular PRP injection on muscle recovery. The data also reveal that the outcome of the early active rehabilitation is adversely affected by the PRP injection when the two therapies are combined, and this could explain why PRP therapies have failed in randomized clinical trials where the athletes have adhered to postinjection rehabilitation protocols based on the principle of early, active mobilization.

Biochemical Characterization of Prions.

PubMed

Fiorini, Michele; Bongianni, Matilde; Monaco, Salvatore; Zanusso, Gianluigi

2017-01-01

Prion disease or transmissible spongiform encephalopathies are characterized by the presence of the abnormal form of the prion protein (PrP Sc ). The pathological and transmissible properties of PrP Sc are enciphered in its secondary and tertiary structures. Since it's well established that different strains of prions are linked to different conformations of PrP Sc , biochemical characterization of prions seems a preliminary but reliable approach to detect, analyze, and compare prion strains. Experimental biochemical procedures might be helpful in distinguishing PrP Sc physicochemical properties and include resistance to proteinase K (PK) digestion, insolubility in nonionic detergents, PK-resistance under denaturing conditions and sedimentation properties in sucrose gradients. This biochemical approach has been extensively applied in human prion disorders and subsequently expanded for PrP Sc characterization in animals. In particular, in sporadic Creutzfedlt-Jakob disease (sCJD) PrP Sc is characterized by two main glycotypes conventionally named Type 1 and Type 2, based on the apparent gel migration at 21 and 19kDa of the PrP Sc PK-resistant fragment. An additional PrP Sc type was identified in sCJD characterized by an unglycosylated dominant glycoform pattern and in 2010 a variably protease-sensitive prionopathy (VPSPr) was reported showing a PrP Sc with an electrophoretic ladder like pattern. Additionally, the presence of PrP Sc truncated fragments completes the electrophoretic characterization of different prion strains. By two-dimensional (2D) electrophoretic analysis additional PrP Sc pattern was identified, since this procedure provides information about the isoelectric point and the different peptides length related to PK cleavage, as well as to glycosylation extent or GPI anchor presence. We here provide and extensive review on PrP Sc biochemical analysis in human and animal prion disorders. Further, we show that PrP Sc glycotypes observed in CJD share similarities with PrP Sc in bovine spongiform encephalopathy forms (BSE). © 2017 Elsevier Inc. All rights reserved.

Pinelliae Rhizoma Praeparatum Involved in the Regulation of Bile Acids Metabolism in Hepatic Injury.

PubMed

Guo, Shun; Zhang, Song; Liu, Linna; Yang, Peng; Dang, Xueliang; Wei, Huamei; Hu, Na; Shi, Lei; Zhang, Yan

2018-06-01

Pinelliae Rhizoma Praeparatum (PRP) as traditional Chinese medicine had been used for hepatic diseases in combinative forms. However, the effect of PRP was not clear when used alone. So to explore the hepatoprotective/hepatotoxin of PRP is necessary. The activities of PRP were investigated in acetaminophen-induced hepatic injury mice. Liver function markers, hepatic oxidative stress markers were evaluated. Bile acids metabolic transports and nuclear factor erythroid 2-related factor 2 (Nrf2) were detected. As a drug for the treatment of liver diseases, PRP slightly restored the parameters towards normal in model mice only in low dosage, and also had no antioxidant activity and regulate Nrf2. Cholestasis was significantly elevated in model mice when pretreatment with routine or high dosage of PRP, but had no effect on normal mice. Bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2) in model mice were markedly increased when pretreatment with low dose PRP, but significantly decreased when pretreatment in routine or high dosage. Mrp3 was significantly induced in model mice after pretreatment of PRP. But the adjustment effect to bile acids transporters by PRP was not significant in normal mice. These results reveal that PRP has the different effects on bile acids transporter in hepatic injury mice, and therefore, the dosage of PRP need to be paid attention to when it is used in clinical hepatic injury.

Autologous platelet-rich plasma: a potential therapeutic tool for promoting hair growth.

PubMed

Li, Zheng Jun; Choi, Hye-In; Choi, Dae-Kyoung; Sohn, Kyung-Cheol; Im, Myung; Seo, Young-Joon; Lee, Young-Ho; Lee, Jeung-Hoon; Lee, Young

2012-07-01

Recently, autologous platelet-rich plasma (PRP) has attracted attention in various medical fields, including plastic and orthopedic surgery and dermatology, for its ability to promote wound healing. PRP has been tested during facelift and hair transplantation to reduce swelling and pain and to increase hair density. To investigate the effects of PRP on hair growth using in vivo and in vitro models. PRP was prepared using the double-spin method and applied to dermal papilla (DP) cells. The proliferative effect of activated PRP on DP cells was measured. To understand the mechanisms of activated PRP on hair growth, we evaluated signaling pathways. In an in vivo study, mice received subcutaneous injections of activated PRP, and their results were compared with control mice. Activated PRP increased the proliferation of DP cells and stimulated extracellular signal-regulated kinase (ERK) and Akt signaling. Fibroblast growth factor 7 (FGF-7) and beta-catenin, which are potent stimuli for hair growth, were upregulated in DP cells. The injection of mice with activated PRP induced faster telogen-to-anagen transition than was seen on control mice. Although few studies tested the effects of activated PRP on hair growth, this research provides support for possible clinical application of autologous PRP and its secretory factors for promotion of hair growth. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

Chitosan inhibits platelet-mediated clot retraction, increases platelet-derived growth factor release, and increases residence time and bioactivity of platelet-rich plasma in vivo.

PubMed

Deprés-Tremblay, Gabrielle; Chevrier, Anik; Tran-Khanh, Nicolas; Nelea, Monica; Buschmann, Michael D

2017-11-10

Platelet-rich plasma (PRP) has been used to treat different orthopedic conditions, however, the clinical benefits of using PRP remain uncertain. Chitosan (CS)-PRP implants have been shown to improve meniscus, rotator cuff and cartilage repair in pre-clinical models. The purpose of this current study was to investigate in vitro and in vivo mechanisms of action of CS-PRP implants. Freeze-dried formulations containing 1% (w/v) CS (80% degree of deacetylation and number average molar mass 38 kDa), 1% (w/v) trehalose as a lyoprotectant and 42.2 mM calcium chloride as a clot activator were solubilized in PRP. Gravimetric measurements and molecular/cellular imaging studies revealed that clot retraction is inhibited in CS-PRP hybrid clots through physical coating of platelets, blood cells and fibrin strands by chitosan, which interferes with platelet aggregation and platelet-mediated clot retraction. Flow cytometry and ELISA assays revealed that platelets are activated and granules secreted in CS-PRP hybrid clots and that cumulative release of platelet-derived growth factor (PDGF-AB) and epidermal growth factor is higher from CS-PRP hybrid clots compared to PRP clots in vitro. Finally, CS-PRP implants resided for up to 6 weeks in a subcutaneous implantation model and induced cell recruitment and granulation tissue synthesis, confirming greater residency and bioactivity compared to PRP in vivo.

Platelet-rich plasma, low-level laser therapy, or their combination promotes periodontal regeneration in fenestration defects: a preliminary in vivo study.

PubMed

Nagata, Maria J H; de Campos, Natália; Messora, Michel R; Pola, Natália M; Santinoni, Carolina S; Bomfim, Suely R M; Fucini, Stephen E; Ervolino, Edilson; de Almeida, Juliano M; Theodoro, Letícia H; Garcia, Valdir G

2014-06-01

This study histomorphometrically analyzes the influence of platelet-rich plasma (PRP), low-level laser therapy (LLLT), or their combination on the healing of periodontal fenestration defects (PFDs) in rats. PFDs were surgically created in the mandibles of 80 rats. The animals were randomly divided into four groups: 1) C (control) and 2) PRP, defects were filled with blood clot or PRP, respectively; 3) LLLT and 4) PRP/LLLT, defects received laser irradiation, were filled with blood clot or PRP, respectively, and then irradiated again. Animals were euthanized at either 10 or 30 days post-surgery. Percentage of new bone (NB), density of newly formed bone (DNB), new cementum (NC), and extension of remaining defect (ERD) were histomorphometrically evaluated. Data were statistically analyzed (analysis of variance; Tukey test, P <0.05). At 10 days, group PRP presented ERD significantly lower than group C. At 30 days, group PRP presented NB and DNB significantly greater than group C. Groups LLLT, PRP, and PRP/LLLT showed significant NC formation at 30 days, with collagen fibers inserted obliquely or perpendicularly to the root surface. NC formation was not observed in any group C specimen. LLLT, PRP, or their combination all promoted NC formation with a functional periodontal ligament. The combination PRP/LLLT did not show additional positive effects compared to the use of either therapy alone.

Does Platelet-Rich Plasma Freeze-Thawing Influence Growth Factor Release and Their Effects on Chondrocytes and Synoviocytes?

PubMed Central

Cavallo, Carola; Cenacchi, Annarita; Facchini, Andrea; Grigolo, Brunella; Kon, Elizaveta; Mariani, Erminia; Pratelli, Loredana; Marcacci, Maurilio

2014-01-01

PRP cryopreservation remains a controversial point. Our purpose was to investigate the effect of freezing/thawing on PRP molecule release, and its effects on the metabolism of chondrocytes and synoviocytes. PRP was prepared from 10 volunteers, and a half volume underwent one freezing/thawing cycle. IL-1β, HGF, PDGF AB/BB, TGF-β1, and VEGF were assayed 1 hour and 7 days after activation. Culture media of chondrocytes and synoviocytes were supplemented with fresh or frozen PRP, and, at 7 days, proliferation, gene expression, and secreted proteins levels were evaluated. Results showed that in the freeze-thawed PRP the immediate and delayed molecule releases were similar or slightly lower than those in fresh PRP. TGF-β1 and PDGF AB/BB concentrations were significantly reduced after freezing both at 1 hour and at 7 days, whereas HGF concentration was significantly lower in frozen PRP at 7 days. In fresh PRP IL-1β and HGF concentrations underwent a significant further increase after 7 days. Similar gene expression was found in chondrocytes cultured with both PRPs, whereas in synoviocytes HGF gene expression was higher in frozen PRP. PRP cryopreservation is a safe procedure, which sufficiently preserves PRP quality and its ability to induce proliferation and the production of ECM components in chondrocytes and synoviocytes. PMID:25136613

Intra-articular laser treatment plus Platelet Rich Plasma (PRP) significantly reduces pain in many patients who had failed prior PRP treatment

NASA Astrophysics Data System (ADS)

Prodromos, Chadwick C.; Finkle, Susan; Dawes, Alexander; Dizon, Angelo

2018-02-01

INTRODUCTION: In our practice Platelet Rich Plasma (PRP) injections effectively reduce pain in most but not all arthritic patients. However, for patients who fail PRP treatment, no good alternative currently exists except total joint replacement surgery. Low level laser therapy (LLLT) on the surface of the skin has not been helpful for arthritis patients in our experience. However, we hypothesized that intra-articular laser treatment would be an effective augmentation to PRP injection and would increase its efficacy in patients who had failed prior PRP injection alone. METHODS: We offered Intra-articular Low Level Laser Therapy (IAL) treatment in conjunction with repeat PRP injection to patients who had received no benefit from PRP injection alone at our center. They were the treatment group. They were not charged for PRP or IAL. They also served as a historical control group since they had all had failed PRP treatment alone. 28 patients (30 joints) accepted treatment after informed consent. 22 knees, 4 hips, 2 shoulder glenohumeral joints and 1 first carpo-metacarpal (1st CMC) joint were treated RESULTS: All patients were followed up at 1 month and no adverse events were seen from the treatment. At 6 months post treatment 46% of patients had good outcomes, and at 1 year 17% still showed improvement after treatment. 11 patients failed treatment and went on to joint replacement. DISCUSSION: A single treatment of IAL with PRP salvaged 46% of patients who had failed PRP treatment alone, allowing avoidance of surgery and good pain control.

Abscisic Acid- and Stress-Induced Highly Proline-Rich Glycoproteins Regulate Root Growth in Rice1[W][OPEN

PubMed Central

Tseng, I-Chieh; Hong, Chwan-Yang; Yu, Su-May; Ho, Tuan-Hua David

2013-01-01

In the root of rice (Oryza sativa), abscisic acid (ABA) treatment, salinity, or water deficit stress induces the expression of a family of four genes, REPETITIVE PROLINE-RICH PROTEIN (RePRP). These genes encode two subclasses of novel proline-rich glycoproteins with highly repetitive PX1PX2 motifs, RePRP1 and RePRP2. RePRP orthologs exist only in monocotyledonous plants, and their functions are virtually unknown. Rice RePRPs are heavily glycosylated with arabinose and glucose on multiple hydroxyproline residues. They are significantly different from arabinogalactan proteins that have glycan chains composed of arabinose and galactose. Transient and stable expressions of RePRP-green fluorescent protein reveal that a fraction of this protein is localized to the plasma membrane. In rice roots, ABA treatment increases RePRP expression preferentially in the elongation zone. Overexpression of RePRP in transgenic rice reduces root cell elongation in the absence of ABA, similar to the effect of ABA on wild-type roots. Conversely, simultaneous knockdown of the expression of RePRP1 and RePRP2 reduces the root sensitivity to ABA, indicating that RePRP proteins play an essential role in ABA/stress regulation of root growth and development. Moreover, rice RePRPs specifically interact with a polysaccharide, arabinogalactan, in a dosage-dependent manner. It is suggested that RePRP1 and RePRP2 are functionally redundant suppressors of root cell expansion and probably act through interactions with cell wall components near the plasma membrane. PMID:23886623

Combination of platelet-rich plasma within periodontal ligament stem cell sheets enhances cell differentiation and matrix production.

PubMed

Xu, Qiu; Li, Bei; Yuan, Lin; Dong, Zhiwei; Zhang, Hao; Wang, Han; Sun, Jin; Ge, Song; Jin, Yan

2017-03-01

The longstanding goal of periodontal therapy is to regenerate periodontal tissues. Although platelet-rich plasma (PRP) has been gaining increasing popularity for use in the orofacial region, whether PRP is useful for periodontal regeneration is still unknown. The purpose of this study was to determine whether a mixture of periodontal ligament stem cell (PDLSC) sheets and PRP promoted bone regeneration, one of the most important measurement indices of periodontal tissue regenerative capability in vitro and in vivo. In this study, we evaluated the effects of different doses of PRP on the differentiation of human PDLSCs. Then cell sheet formation, extracellular matrix deposition and osteogenic gene expression in response to different doses of PRP treatment during sheet grafting was investigated. Furthermore, we implanted PDLSC sheets treated with 1% PRP subcutaneously into immunocompromised mice to evaluate their bone-regenerative capability. The results revealed that 1% PRP significantly enhanced the osteogenic differentiation of PDLSCs. Based on the production of extracellular matrix proteins, the results of scanning electron microscopy and the expression of the osteogenic genes ALP, Runx2, Col-1 and OCN, the provision of 1% PRP for PDLSC sheets was the most effective PRP administration mode for cell sheet formation. The results of in vivo transplantation showed that 1% PRP-mediated PDLSC sheets exhibited better periodontal tissue regenerative capability than those obtained without PRP intervention. These data suggest that a suitable concentration of PRP stimulation may enhance extracellular matrix production and positively affect cell behaviour in PDLSC sheets. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Effects of the breed, sex and age on cellular content and growth factor release from equine pure-platelet rich plasma and pure-platelet rich gel.

PubMed

Giraldo, Carlos E; López, Catalina; Álvarez, María E; Samudio, Ismael J; Prades, Marta; Carmona, Jorge U

2013-02-12

There is no information on the effects of the breed, gender and age on the cellular content and growth factor (GF) release from equine pure-platelet rich plasma (P-PRP) and pure-platelet rich gel (P-PRG). The objectives of this study were: 1) to compare the cellular composition of P-PRP with whole blood and platelet poor plasma (PPP); 2) to compare the concentration of transforming GF beta 1 (TGF-β1) and platelet derived GF isoform BB (PDGF-BB) between P-PRP treated with non-ionic detergent (P-PRP+NID), P-PRG (activated with calcium gluconate -CG-), PPP+NID, PPP gel (PPG), and plasma and; 3) to evaluate and to correlate the effect of the breed, gender and age on the cellular and GF concentration for each blood component. Forty adult horses, 20 Argentinean Creole Horses (ACH) and, 20 Colombian Creole Horses (CCH) were included. Data were analyzed by parametric (i.e.: t-test, one way ANOVA) and non parametric (Kruskal-Wallis test, Wilcoxon test) tests. Correlation analysis was also performed by using the Spearman and Pearson tests. A p ≤ 0.05 was set as significant for all tests. All the blood components were compared for platelet (PLT), leukocyte (WBC), TGF-β1 and PDGF-BB concentrations. The effect of the breed, gender and age on these variables was analyzed. A P ≤ 0.05 was accepted as significant for all the tests. PLT counts were 1.8 and 0.6 times higher in P-PRP than in whole blood and PPP, respectively; WBC counts were 0.5 and 0.1 times lower in P-PRP, in comparison with whole blood and PPP, respectively. TGF-β1 and PDGF-BB concentrations were 2.3 and 262 times higher, respectively, in P-PRG than in plasma, and 0.59 and 0.48 times higher, respectively, in P-PRG than in PPG. P-PRG derived from CCH females or young horses presented significantly (P < 0.001) higher PDGF-BB concentrations than P-PRG derived from ACH males or older horses. Our results indicated that P-PRP obtained by a manual method was affected by intrinsic factors such as the breed, gender and age. Equine practitioners should be aware that cellular and GF release from P-PRP/P-PRG could change according with the intrinsic variables associated with a patient in particular.

PRP Treatment Efficacy for Tendinopathy: A Review of Basic Science Studies

PubMed Central

2016-01-01

Platelet-Rich Plasma (PRP) has been widely used in orthopaedic surgery and sport medicine to treat tendon injuries. However, the efficacy of PRP treatment for tendinopathy is controversial. This paper focuses on reviewing the basic science studies on PRP performed under well-controlled conditions. Both in vitro and in vivo studies describe PRP's anabolic and anti-inflammatory effects on tendons. While some clinical trials support these findings, others refute them. In this review, we discuss the effectiveness of PRP to treat tendon injuries with evidence presented in basic science studies and the potential reasons for the controversial results in clinical trials. Finally, we comment on the approaches that may be required to improve the efficacy of PRP treatment for tendinopathy. PMID:27610386

Mandibular Third Molar Extraction Wound Healing With and Without Platelet Rich Plasma: A Comparative Prospective Study.

PubMed

Dutta, Shubha Ranjan; Singh, Purnima; Passi, Deepak; Patter, Pradeep

2015-09-01

To evaluate the efficacy of autologous platelet rich plasma (PRP) in regeneration of bone and to assess clinical compatibility of the material in mandibular third molar extraction socket. To compare the healing of mandibular third molar extraction wounds with and without PRP. Group A consists of the 30 patients where PRP will be placed in the extraction socket before closure of the socket. Group B consists of 30 patients who will be the control group where the extraction sockets will be closed without any intra socket medicaments. The patients would be allocated to the groups randomly. Soft tissue healing was better in study site compared to control site. The result of the study shows rapid bone regeneration in the extraction socket treated with PRP when compared with the socket without PRP. Evaluation for bone blending and trabecular bone formation started earlier in PRP site compared to control, non PRP site. Also there was less postoperative discomfort on the PRP treated side. Autologous PRP is biocompatible and has significant improved soft tissue healing, bone regeneration and increase in bone density in extraction sockets.

PRP19 Transforms into a Sensor of RPA-ssDNA after DNA Damage and Drives ATR Activation via a Ubiquitin-Mediated Circuitry

PubMed Central

Maréchal, Alexandre; Wu, Ching-Shyi; Yazinski, Stephanie A.; Nguyen, Hai Dang; Liu, Shizhou; Jiménez, Amanda E.; Jin, Jianping; Zou, Lee

2014-01-01

Summary PRP19 is a ubiquitin ligase involved in pre-mRNA splicing and the DNA damage response (DDR). While the role for PRP19 in splicing is well characterized, its role in the DDR remains elusive. Through a proteomic screen for proteins that interact with RPA-coated single-stranded DNA (RPA-ssDNA), we identified PRP19 as a sensor of DNA damage. PRP19 binds RPA directly and localizes to DNA damage sites via RPA, promoting RPA ubiquitylation in a DNA damage-induced manner. PRP19 facilitates the accumulation of ATRIP, the regulatory partner of the ATR kinase, at DNA damage sites. Depletion of PRP19 compromised the phosphorylation of ATR substrates, the recovery of stalled replication forks, and the progression of replication forks on damaged DNA. Importantly, PRP19 mutants that cannot bind RPA or function as an E3 ligase failed to support the ATR response, revealing that PRP19 drives ATR activation by acting as an RPA-ssDNA-sensing ubiquitin ligase during the DDR. PMID:24332808

Commercial Separation Systems Designed for Preparation of Platelet-Rich Plasma Yield Differences in Cellular Composition.

PubMed

Degen, Ryan M; Bernard, Johnathan A; Oliver, Kristin S; Dines, Joshua S

2017-02-01

The role of platelet-rich plasma (PRP) in the treatment of sport-related injuries is unclear, largely due to the heterogeneity of clinical results. This may relate to compositional differences in PRP from different separation systems. This study aims to compare the composition of PRP produced with five different commercially available systems, focusing on cellular concentrations and pH. Seven donors (41 ± 12 years) provided blood for PRP preparation using five systems (Arthrex Angel, Emcyte Genesis CS, Arteriocyte Magellan, Harvest SmartPrep, and Biomet GPS III). Post processing, cellular composition was measured including platelets (PLT), white blood cells (WBC), neutrophils (NE), and red blood cells (RBC), as well as pH. Platelet concentration and capture efficiency were similar between systems, except the Angel 7% preparation had a greater concentration than Genesis CS (2310 ± 524 vs. 1129 ± 264 k/μL). WBC concentration was variable between systems; however, significant differences were only found between the Angel 2% and GPS III preparations (11.0 ± 4.5, 27.3 ± 7.1 k/μL). NE concentration was significantly lower in the Angel 2% and 7% preparations compared with GPS III (0.6 ± 0.6 and 1.8 ± 1.3 k/μL vs. 9.4 ± 7.0 k/μL). RBC concentration was highest in SmartPrep (3.2 ± 0.6 M/μL) and Genesis CS systems (3.1 ± 0.6 M/μL) compared with all other systems (≤1.1 ± 1.2 M/μL). Finally, pH was significantly lower with the SmartPrep system (6.95 ± 0.06) compared with all others (≥7.26 ± 0.06). Aside from platelet concentration and capture efficiency, significant compositional differences were identified between preparation systems. Caution should be employed when interpreting clinical results of studies utilizing PRP, as the role of compositional differences and their effect on outcome are unknown. Further study is necessary to determine the clinical significance of these differences.

Crystal Structure of the C-terminal Domain of Splicing Factor Prp8 Carrying Retinitis Pigmentosa Mutants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang,L.; Shen, J.; Guarnieri, M.

2007-01-01

Prp8 is a critical pre-mRNA splicing factor. Prp8 is proposed to help form and stabilize the spliceosome catalytic core and to be an important regulator of spliceosome activation. Mutations in human Prp8 (hPrp8) cause a severe form of the genetic disorder retinitis pigmentosa, RP13. Understanding the molecular mechanism of Prp8's function in pre-mRNA splicing and RP13 has been hindered by its large size (over 2000 amino acids) and remarkably low-sequence similarity with other proteins. Here we present the crystal structure of the C-terminal domain (the last 273 residues) of Caenorhabditis elegans Prp8 (cPrp8). The core of the C-terminal domain ismore » an / structure that forms the MPN (Mpr1, Pad1 N-terminal) fold but without Zn{sup 2+} coordination. We propose that the C-terminal domain is a protein interaction domain instead of a Zn{sup 2+}-dependent metalloenzyme as proposed for some MPN proteins. Mapping of RP13 mutants on the Prp8 structure suggests that these residues constitute a binding surface between Prp8 and other partner(s), and the disruption of this interaction provides a plausible molecular mechanism for RP13.« less

The role of the unusual threonine string in the conversion of prion protein.

PubMed

Abskharon, Romany; Wang, Fei; Vander Stel, Kayla J; Sinniah, Kumar; Ma, Jiyan

2016-12-16

The conversion of normal prion protein (PrP) into pathogenic PrP conformers is central to prion disease, but the mechanism remains unclear. The α-helix 2 of PrP contains a string of four threonines, which is unusual due to the high propensity of threonine to form β-sheets. This structural feature was proposed as the basis for initiating PrP conversion, but experimental results have been conflicting. We studied the role of the threonine string on PrP conversion by analyzing mouse Prnp a and Prnp b polymorphism that contains a polymorphic residue at the beginning of the threonine string, and PrP mutants in which threonine 191 was replaced by valine, alanine, or proline. The PMCA (protein misfolding cyclic amplification) assay was able to recapitulate the in vivo transmission barrier between PrP a and PrP b . Relative to PMCA, the amyloid fibril growth assay is less restrictive, but it did reflect certain properties of in vivo prion transmission. Our results suggest a plausible theory explaining the apparently contradictory results in the role of the threonine string in PrP conversion and provide novel insights into the complicated relationship among PrP stability, seeded conformational change, and prion structure, which is critical for understanding the molecular basis of prion infectivity.

Contingent capture of visual-spatial attention depends on capacity-limited central mechanisms: evidence from human electrophysiology and the psychological refractory period.

PubMed

Brisson, Benoit; Leblanc, Emilie; Jolicoeur, Pierre

2009-02-01

It has recently been demonstrated that a lateralized distractor that matches the individual's top-down control settings elicits an N2pc wave, an electrophysiological index of the focus of visual-spatial attention, indicating that contingent capture has a visual-spatial locus. Here, we investigated whether contingent capture required capacity-limited central resources by incorporating a contingent capture task as the second task of a psychological refractory period (PRP) dual-task paradigm. The N2pc was used to monitor where observers were attending while they performed concurrent central processing known to cause the PRP effect. The N2pc elicited by the lateralized distractor that matched the top-down control settings was attenuated in high concurrent central load conditions, indicating that although involuntary, the deployment of visual-spatial attention occurring during contingent capture depends on capacity-limited central resources.

A Midterm Evaluation of Postoperative Platelet-Rich Plasma Injections on Arthroscopic Supraspinatus Repair: A Randomized Controlled Trial.

PubMed

Ebert, Jay R; Wang, Allan; Smith, Anne; Nairn, Robert; Breidahl, William; Zheng, Ming Hao; Ackland, Timothy

2017-11-01

Platelet-rich plasma (PRP) has been applied as an adjunct to rotator cuff repair to improve tendon-bone healing and potentially reduce the incidence of subsequent tendon retears. To investigate whether the midterm clinical and radiographic outcomes of arthroscopic supraspinatus repair are enhanced after repeated postoperative applications of PRP. Randomized controlled trial; Level of evidence, 1. A total of 60 patients (30 control; 30 PRP) were initially randomized to receive 2 ultrasound-guided injections of PRP to the tendon repair site at 7 and 14 days after double-row arthroscopic supraspinatus repair or not. A total of 55 patients (91.7%) underwent a clinical review and magnetic resonance imaging (MRI) at a mean of 3.5 years after surgery (range, 36-51 months). Patient-reported outcome measures (PROMs) included the Constant score, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire, Oxford Shoulder Score (OSS), and visual analog scale (VAS) for pain. Global rating of change (GRC) scale and patient satisfaction scores were evaluated. Structural integrity of the surgical repair was assessed via MRI using the Sugaya classification system. At the midterm review, there was no difference between the groups for any of the PROMs. No differences between the groups were demonstrated for the subjective and range of motion subscales of the Constant score, although a significantly higher Constant strength subscale score was observed in the PRP group (3.3 points; 95% CI, 1.0-5.7; P = .006). There was no evidence for any group differences in MRI scores or retear rates, with 66.7% of PRP patients and 64.3% of control patients rated as Sugaya grade 1. Two control patients had symptomatic retears (both full thickness) within the first 16 weeks after surgery compared with 2 PRP patients, who suffered symptomatic retears (both partial thickness) between 16 weeks and a mean 3.5-year follow-up. Significant postoperative clinical improvements and high levels of patient satisfaction were observed in patients at the midterm review after supraspinatus repair. While pain-free, maximal abduction strength was greater in the midterm after PRP treatment, repeated applications of PRP delivered at 7 and 14 days after surgery provided no additional benefit to tendon integrity.

Platelet-rich plasma therapy - future or trend?

PubMed Central

2012-01-01

Chronic complex musculoskeletal injuries that are slow to heal pose challenges to physicians and researchers alike. Orthobiologics is a relatively newer science that involves application of naturally found materials from biological sources (for example, cell-based therapies), and offers exciting new possibilities to promote and accelerate bone and soft tissue healing. Platelet-rich plasma (PRP) is an orthobiologic that has recently gained popularity as an adjuvant treatment for musculoskeletal injuries. It is a volume of fractionated plasma from the patient's own blood that contains platelet concentrate. The platelets contain alpha granules that are rich in several growth factors, such as platelet-derived growth factor, transforming growth factor-β, insulin-like growth factor, vascular endothelial growth factor and epidermal growth factor, which play key roles in tissue repair mechanisms. PRP has found application in diverse surgical fields to enhance bone and soft-tissue healing by placing supra-physiological concentrations of autologous platelets at the site of tissue damage. The relative ease of preparation, applicability in the clinical setting, favorable safety profile and possible beneficial outcome make PRP a promising therapeutic approach for future regenerative treatments. However, there is a large knowledge gap in our understanding of PRPs mechanism of action, which has raised skepticism regarding its potential efficacy and use. Thus, the aim of this review is to describe the various factors proposed to contribute to the biological activity of PRP, and the published pre-clinical and clinical evidence to support it. Additionally, we describe the current techniques and technology for PRP preparation, and review the present shortcomings of this therapy that will need to be overcome if it is to gain broad acceptance. PMID:22894643

Factors before enrolment are associated with being removed from a Pharmacy-only Refill Programme at a large urban HIV/AIDS clinic, Uganda.

PubMed

Nakiwogga-Muwanga, A; Katabira, E; Kiragga, A; Kambugu, A; Nakibuuka-Lubwama, E; Manabe, Y C; Alamo, S T; Colebunders, R

2014-02-01

A Pharmacy-only Refill Programme (PRP) a type of task shifting in which stable HIV-positive patients are managed through pharmacy-only visits instead of physician visits. We performed a study to identify factors for being removed from the PRP in order to establish better referral criteria. The study was performed at the Infectious Disease Clinic (IDC) in Kampala, Uganda. We selected a random sample of 588 patients from 2431 patients on antiretroviral therapy referred to the PRP at least 12 months before commencement of the PRP evaluation. We compared the characteristics of patients who during 12 months of follow-up were removed from the PRP with those who continued to be followed up. Data were abstracted from the IDC data base, the pharmacy register and the patient clinical notes. Of 588 patients, 106 (18%) were removed from the PRP. In multivariate analysis, less than 100% self-reported adherence to antiretroviral therapy, missing at least one scheduled appointment in the six months before referral to the PRP and being on a lopinavir/ritonavir-containing regimen were independently associated with being removed from the PRP. Criteria for referring patients to a PRP should focus on antiretroviral therapy adherence and appointment keeping. Patients on a lopinavir/ritonavir-containing regimen should not be targeted for a PRP. On the other hand a PRP is an efficient strategy that targets stable adherent patients in clinics with high patient load.

Effect of two different preparations of platelet-rich plasma on synoviocytes.

PubMed

Assirelli, Elisa; Filardo, Giuseppe; Mariani, Erminia; Kon, Elizaveta; Roffi, Alice; Vaccaro, Franca; Marcacci, Maurilio; Facchini, Andrea; Pulsatelli, Lia

2015-09-01

To analyse the modifications induced by two different platelet-rich plasma (PRP) preparations on osteoarthritis (OA) synoviocytes, by documenting changes in gene expression of factors involved in joint physiopathology. OA synoviocytes were cultured for 7 days in medium with different concentrations of either P-PRP (a pure platelet concentrate without leucocytes but with a limited number of platelets), L-PRP (a higher platelet concentrate containing leucocytes) or platelet-poor plasma (PPP). Gene expression of interleukin (IL)-1beta, IL-6, IL-8/CXCL8, tumour necrosis factor alpha, IL-10, IL-4, IL-13, metalloproteinase-13, tissue inhibitor of metalloproteinase (TIMP)-1, (TIMP)-3, (TIMP)-4, vascular endothelial growth factor, transforming growth factor beta1, fibroblast growth factor (FGF)-2, hepatocyte growth factor (HGF), hyaluronic acid (HA) synthases (HAS)-1, (HAS)-2, and (HAS)-3 was analysed by RT-PCR. HA production was determined in culture supernatants by ELISA. IL-1β, IL-8 and FGF-2 were significantly induced by L-PRP compared to both P-PRP and PPP; HGF was down-modulated by L-PRP versus both P-PRP and PPP, and an inverse dose-response influence was shown for all preparations. Expression level of TIMP-4 was lower in the presence of L-PRP compared with P-PRP. HA production and HAS gene expression did not seem to be modulated by PRP. L-PRP is able to sustain the up-regulation of proinflammatory factors, (IL-1beta, IL-8 and FGF-2), together with a down-modulation of HGF and TIMP-4 expression, two factors that have been recognized as anti-catabolic mediators in cartilage, thus supporting the need to further optimize the PRP preparations to be applied in clinical practice.

Advantages of Pure Platelet-Rich Plasma Compared with Leukocyte- and Platelet-Rich Plasma in Treating Rabbit Knee Osteoarthritis

PubMed Central

Yin, Wen-Jing; Xu, Hai-Tao; Sheng, Jia-Gen; An, Zhi-Quan; Guo, Shang-Chun; Xie, Xue-Tao; Zhang, Chang-Qing

2016-01-01

Background Concentrated leukocytes in leukocyte- and platelet-rich plasma (L-PRP) may deliver increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage. However, to date no relevant studies have substantiated that in vivo. Material/Methods Autologous L-PRP and pure platelet-rich plasma (P-PRP) were prepared, measured for componential composition, and injected intra-articularly after 4, 5, and 6 weeks post-anterior cruciate ligament transection. Caffeic acid phenethyl ester (CAPE) was injected intraperitoneally to inhibit NF-κB activation. All rabbits were sacrificed after 8 weeks postoperative. Enzyme-linked immunosorbent assays were performed to determine interleukin 1β (IL-1β) and prostaglandin E2 (PGE2) concentrations in the synovial fluid, Indian ink staining was performed for gross morphological assessment, and hematoxylin and eosin staining and toluidine blue staining were performed for histological assessment. Results Compared with L-PRP, P-PRP injections achieved better outcomes regarding the prevention of cartilage destruction, preservation of cartilaginous matrix, and reduction of IL-1β and PGE2 concentrations. CAPE injections reversed the increased IL-1β and PGE2 concentrations in the synovial fluid after L-PRP injections and improved the outcome of L-PRP injections to a level similar to P-PRP injections, while they had no influence on the therapeutic efficacy of P-PRP injections. Conclusions Concentrated leukocytes in L-PRP may release increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage, and finally, result in a inferior efficacy of L-PRP to P-PRP for the treatment of osteoarthritis. PMID:27086145

Advantages of Pure Platelet-Rich Plasma Compared with Leukocyte- and Platelet-Rich Plasma in Treating Rabbit Knee Osteoarthritis.

PubMed

Yin, Wen-Jing; Xu, Hai-Tao; Sheng, Jia-Gen; An, Zhi-Quan; Guo, Shang-Chun; Xie, Xue-Tao; Zhang, Chang-Qing

2016-04-17

BACKGROUND Concentrated leukocytes in leukocyte- and platelet-rich plasma (L-PRP) may deliver increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage. However, to date no relevant studies have substantiated that in vivo. MATERIAL AND METHODS Autologous L-PRP and pure platelet-rich plasma (P-PRP) were prepared, measured for componential composition, and injected intra-articularly after 4, 5, and 6 weeks post-anterior cruciate ligament transection. Caffeic acid phenethyl ester (CAPE) was injected intraperitoneally to inhibit NF-κB activation. All rabbits were sacrificed after 8 weeks postoperative. Enzyme-linked immunosorbent assays were performed to determine interleukin 1β (IL-1β) and prostaglandin E2 (PGE2) concentrations in the synovial fluid, Indian ink staining was performed for gross morphological assessment, and hematoxylin and eosin staining and toluidine blue staining were performed for histological assessment. RESULTS Compared with L-PRP, P-PRP injections achieved better outcomes regarding the prevention of cartilage destruction, preservation of cartilaginous matrix, and reduction of IL-1β and PGE2 concentrations. CAPE injections reversed the increased IL-1β and PGE2 concentrations in the synovial fluid after L-PRP injections and improved the outcome of L-PRP injections to a level similar to P-PRP injections, while they had no influence on the therapeutic efficacy of P-PRP injections. CONCLUSIONS Concentrated leukocytes in L-PRP may release increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage, and finally, result in a inferior efficacy of L-PRP to P-PRP for the treatment of osteoarthritis.

Polysaccharide of radix pseudostellariae improves chronic fatigue syndrome induced by poly I:C in mice.

PubMed

Sheng, Rong; Xu, Xianxiang; Tang, Qin; Bian, Difei; Li, Ying; Qian, Cheng; He, Xin; Gao, Xinghua; Pan, Rong; Wang, Chong; Luo, Yubin; Xia, Yufeng; Dai, Yue

2011-01-01

Radix Pseudostellariae is used as a tonic drug in traditional Chinese medicine with immunomodulating and anti-fatigue activities, and the polysaccharide is considered as the main active component. The purpose of this study is to examine the effect of the polysaccharide isolated from Radix Pseudostellariae (PRP) on mouse chronic fatigue syndrome (CFS) induced by intraperitoneal injection of polyriboinosinic:polyribocytidylic acid (poly I:C), a double-stranded synthetic RNA. It has shown that the fatigue symptom of mice lasted at least 1 week as evaluated by forced swimming time. PRP (100, 200, 400 mg kg(-1)), orally administered 3 days before poly I:C injection, showed dose-dependent anti-fatigue effects. In addition, poly I:C led to evident alternations in neuroendocrine and immune systems of mice, such as reduced spontaneous activity and learning ability, declined serum level of corticosterone, increased weight indexes and T lymphocyte numbers in thymuses and spleens, and increased CD4(+)/CD8(+) ratio but decreased proliferation ability of T lymphocytes in spleens. PRP alleviated the abnormalities caused by poly I:C, and restored the function of hosts to normal conditions. The findings suggest that PRP is beneficial to CFS, and the underlying mechanisms of action involve neuroendocrine and immune systems.

Coarse-grained modeling of proline rich protein 1 (PRP-1) in bulk solution and adsorbed to a negatively charged surface.

PubMed

Skepö, Marie; Linse, Per; Arnebrant, Thomas

2006-06-22

Structural properties of the acidic proline rich protein PRP-1 of salivary origin in bulk solution and adsorbed onto a negatively charged surface have been studied by Monte Carlo simulations. A simple model system with focus on electrostatic interactions and short-ranged attractions among the uncharged amino acids has been used. In addition to PRP-1, some mutants were considered to assess the role of the interactions in the systems. Contrary to polyelectrolytes, the protein has a compact structure in salt-free bulk solutions, whereas at high salt concentration the protein becomes more extended. The protein adsorbs to a negatively charged surface, although its net charge is negative. The adsorbed protein displays an extended structure, which becomes more compact upon addition of salt. Hence, the conformational response upon salt addition in the adsorbed state is the opposite as compared to that in bulk solution. The conformational behavior of PRP-1 in bulk solution and at charged surfaces as well as its propensity to adsorb to surfaces with the same net charge are rationalized by the block polyampholytic character of the protein. The presence of a triad of positively charged amino acids in the C-terminal was found to be important for the adsorption of the protein.

Matrix metalloproteinase content and activity in low-platelet, low-leukocyte and high-platelet, high-leukocyte platelet rich plasma (PRP) and the biologic response to PRP by human ligament fibroblasts.

PubMed

Pifer, Matthew A; Maerz, Tristan; Baker, Kevin C; Anderson, Kyle

2014-05-01

Recent work has shown the presence of catabolic cytokines in platelet-rich plasma (PRP), but little is known about endogenous catabolic proteases such as matrix metalloproteinases (MMPs). Hypothesis/ To quantify MMP content in 2 commercially available PRP preparation systems: Arthrex Double Syringe System autologous conditioned plasma (ACP) and Biomet GPS (GPS). The hypothesis was that MMPs are actively secreted from PRP immediately after preparation. Controlled laboratory study. PRP was prepared using either ACP (low platelet, low leukocyte) or GPS (high platelet, high leukocyte). MMP-2, MMP-3, and MMP-9 concentrations were measured using multiplex enzyme-linked immunosorbent assays for up to 6 days in 2 donors, and MMP activity was measured in 3 donors using kinetic activity kits able to detect the enzymatic cleavage of a fluorogenic peptide. Human ligament fibroblasts were cultured and exposed to both ACP and GPS from 1 donor each. MMP-2, -3, and -9 concentrations were assayed in culture media at 24 and 48 hours after exposure. GPS exhibited higher total MMP-2, -3, and -9 concentrations for up to 144 hours of release, while ACP had higher platelet-normalized MMP-2 and MMP-3 concentrations. GPS had significantly higher total and endogenous MMP-2 activity (P = .004 and .014, respectively), MMP-3 activity (P = .020 and .015, respectively), and MMP-9 activity (P = .004 and .002, respectively) compared with ACP. Once normalized to platelet count, differences in MMP activity were not significant between ACP and GPS. Compared with controls, cells stimulated with interleukin-1 beta (IL-1β) and treated with ACP showed significantly higher fold changes of MMP-2 (P = .001) and MMP-3 (P = .003) concentrations at 24 hours than did cells treated with GPS. Total MMP-9 content was higher in the media of GPS-treated, IL-1β-stimulated cells compared with ACP-treated cells (P = .001). At 48 hours, IL-1β-stimulated cells treated with GPS exhibited higher fold changes of MMP-2 concentration (P = .002) compared with controls, but no difference in MMP-3 concentration was found. At 48 hours, there was a significantly higher concentration of MMP-9 in the cell culture media of ACP-treated cells compared with GPS-treated cells (P = .003). PRP prepared as both ACP and GPS contains MMP-2, -3, and -9, which is released over a period of at least 6 days. Furthermore, a large proportion of these MMPs are in their active form, and MMP activity is dependent on platelet count within the PRP preparation. Once exposed to ligament fibroblasts, both ACP and GPS cause the fibroblasts to release MMPs, most notably 24 hours after PRP exposure, and this release is dependent on prior IL-1β stimulation. The results of this study demonstrate that PRP therapy delivers ng/mL-range concentrations of catabolic proteases, which could perpetuate inflammation and inhibit tissue healing.

Epidemiology, Treatment Efficacy, and Anxiety Aspects of Music Students Affected by Playing-Related Pain: A Retrospective Evaluation with Follow-up.

PubMed

Ioannou, Christos I; Hafer, Julia; Lee, André; Altenmüller, Eckart

2018-03-01

Playing-related pain (PRP) is a common problem among music students. We retrospectively assessed epidemiological factors that contributed to the manifestation of PRP and evaluated the efficacy of treatment methods used by affected music students. The long-term course of PRP symptoms was also examined, along with current (today) levels of trait anxieties. Demographic and epidemiological data of 186 music students who visited the musicians' outpatient clinic over a 5-year period were retrieved. Of these students, 122 had been diagnosed with PRP and were invited to participate (response rate 61.5%) in a follow-up online survey to: a) estimate the long-term course of their PRP symptoms, b) assess the efficacy of treatment methods they used, and c) assess their current trait anxiety (general and performance-related) using two standardized psychodiagnostic questionnaires. Two-thirds of music students who sought medical care were affected by PRP, with most being affected during their first year of studies, and with 69% having acute rather than chronic pain. The sudden increase in practice time was the main triggering factor for PRP (but not for non-PRP-related problems). Concerning the course of PRP, almost all students recovered or improved significantly. Students reported that "active" treatment methods (e.g., physical activities) were more effective than "passive" methods (e.g., oral medications). Psychodiagnostic questionnaires indicated that about 40% of PRP-affected students currently had increased levels of trait anxieties (music and non-music related), possibly warranting further medical assistance. PRP in music students occurs mainly at the beginning of their studies and has a good prognosis, although recovery may be lengthy. It is necessary to provide students with early information about PRP and about the multidimensional treatment framework that allows for individualized care of PRP in affected music students.

Platelet-rich plasma can replace fetal bovine serum in human meniscus cell cultures.

PubMed

Gonzales, Veronica K; de Mulder, Eric L W; de Boer, Trix; Hannink, Gerjon; van Tienen, Tony G; van Heerde, Waander L; Buma, Pieter

2013-11-01

Concerns over fetal bovine serum (FBS) limit the clinical application of cultured tissue-engineered constructs. Therefore, we investigated if platelet-rich plasma (PRP) can fully replace FBS for meniscus tissue engineering purposes. Human PRP and platelet-poor plasma (PPP) were isolated from three healthy adult donors. Human meniscal fibrochondrocytes (MFCs) were isolated from resected tissue after a partial meniscectomy on a young patient. Passage-4 MFCs were cultured in monolayer for 24 h, and 3 and 7 days. Six different culture media were used containing different amounts of either PRP or PPP and compared to a medium containing 10% FBS. dsDNA was quantified, and gene expression levels of collagen types I and II and aggrecan were measured at different time points with quantitative polymerase chain reaction in the cultured MFCs. After 7 days, the dsDNA quantity was significantly higher in MFCs cultured in 10% and 20% PRP compared to the other PRP and PPP conditions, but equal to 10% FBS. Collagen type I expression was lower in MFCs cultured with medium containing 5% PRP, 10% and 20% PPP compared to FBS. When medium with 10% PRP or 20% PRP was used, expressions were not significantly different from medium containing 10% FBS. Collagen type II expression was absent in all medium conditions. Aggrecan expression did not show differences between the different media used. However, after 7 days a higher aggrecan expression was measured in most culture conditions, except for 5% PRP, which was similar compared to FBS. Statistical significance was found between donors at various time points in DNA quantification and gene expression, but the same donors were not statistically different in all conditions. At 7 days cell cultured with 10% PRP and 20% PRP showed a higher density, with large areas of clusters, compared to other conditions. In an MFC culture medium, FBS can be replaced by 10% PRP or 20% PRP without altering proliferation and gene expression of human MFCs.

Bone Marrow Aspirate Concentrate versus Platelet Rich Plasma to Enhance Osseous Integration Potential for Osteochondral Allografts.

PubMed

Stoker, Aaron M; Baumann, Charles A; Stannard, James P; Cook, James L

2018-04-01

Fresh osteochondral allograft (OCA) transplantation is an attractive treatment option for symptomatic articular cartilage lesions in young, healthy patients. Since a lack of OCA bone integration can be a cause of treatment failure, methods for speeding and enhancing OCA bone integration to mitigate this potential complication are highly desirable. This study sought to determine and compare the potential of bone marrow aspirate concentrate (BMC) and leukoreduced platelet rich plasma (PRP) to repopulate the osseous portion of an OCA with cells and deliver osteogenic proteins. It was hypothesized that BMC would have significantly higher colony forming units (CFUs)/mL and seed the osseous portion of OCA with more cells than PRP. Finally, we hypothesized that the media of BMC and PRP treated OCAs would have significantly higher concentrations of osteogenic proteins compared with negative control OCAs. Cylindrical OCAs ( n  = 36) created from tissue stored for 21 days were treated with BMC ( n  = 12) or PRP ( n  = 12) obtained for 6 dogs, or left untreated as a negative control ( n  = 12). After treatment, OCAs were cultured for 7 or 14 days. Media were collected for analysis of osteogenic biomarker concentration. Samples of each BMC and PRP were tested for CFU concentration. On day 7 or 14, the grafts were assessed for cell surface adhesion and penetration using fluorescent microscopy. Significant differences in CFU and media biomarker concentration between the groups were determined using one-way analysis of variance (ANOVA) and Tukey's post-hoc test with the significance set at p  < 0.05. Only OCAs saturated with BMC had viable cells detectable on the osseous portion of the allografts at day 7 and 14 of culture. BMC samples had a significantly higher ( p  = 0.029) CFU/mL compared with PRP samples. At day 3 and/or 7 of culture, the concentration of several osteogenic proteins was significantly higher in both BMC and PRP samples. Autogenous BMC can be used to deliver both a cell population and osteogenic proteins that may improve healing of the osseous portion of the OCA clinically. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Recent Advances in Fractional Laser Resurfacing: New Paradigm in Optimal Parameters and Post-Treatment Wound Care

PubMed Central

Hsiao, Francis C.; Bock, Gerald N.; Eisen, Daniel B.

2012-01-01

Background Laser plays an increasingly prominent role in skin rejuvenation. The advent of fractional photothermolysis revolutionizes its application. Microcolumns of skin are focally injured, leaving intervening normal skin to facilitate rapid wound healing and orderly tissue remodeling. The Problem Even with the popularity of fractional laser devices, we still have limited knowledge about the ideal treatment parameters and postlaser wound care. Basic/Clinical Science Advances Many clinicians believe that higher microbream energy in fractional laser devices results in better clinical outcome. Two recent studies argue against this assumption. One article demonstrates that lower fluence can induce comparable molecular changes with fewer side effects. Another study corroborates this by showing that lower-density settings produce similar clinical outcome in scar remodeling as higher-density ones, but with fewer side effects. To shed light on the optimal post-treatment wound care regimen from fractional ablative resurfacing, another paper shows that platelet-rich plasma (PRP) can reduce transepidermal water loss and skin color changes within 1 month after treatment. Clinical Care Relevance For fractional nonablative resurfacing, lower settings in fluence or density may produce similar dermal remodeling as higher settings and with a better side-effect profile. Moreover, autologous PRP appears to expedite wound healing after fractional ablative resurfacing. Conclusion Lower microbeam energy in fractional laser resurfacing produces similar molecular changes and clinical outcome with fewer side effects. The findings might portend a shift in the paradigm of treatment parameters. Autologous PRP can facilitate better wound healing, albeit modestly. Long-term follow-ups and larger studies are necessary to confirm these findings. PMID:24527307

The inhibition of functional expression of calcium channels by prion protein demonstrates competition with α2δ for GPI-anchoring pathways

PubMed Central

Alvarez-Laviada, Anita; Kadurin, Ivan; Senatore, Assunta; Chiesa, Roberto; Dolphin, Annette C.

2013-01-01

It has been shown recently that PrP (prion protein) and the calcium channel auxiliary α2δ subunits interact in neurons and expression systems [Senatore, Colleoni, Verderio, Restelli, Morini, Condliffe, Bertani, Mantovani, Canovi, Micotti, Forloni, Dolphin, Matteoli, Gobbi and Chiesa (2012) Neuron 74, 300–313]. In the present study we examined whether there was an effect of PrP on calcium currents. We have shown that when PrP is co-expressed with calcium channels formed from CaV2.1/β and α2δ-1 or α2δ-2, there is a consistent decrease in calcium current density. This reduction was absent when a PrP construct was used lacking its GPI (glycosylphosphatidylinositol) anchor. We have reported previously that α2δ subunits are able to form GPI-anchored proteins [Davies, Kadurin, Alvarez-Laviada, Douglas, Nieto-Rostro, Bauer, Pratt and Dolphin (2010) Proc. Natl. Acad. Sci. U.S.A. 107, 1654–1659] and show further evidence in the present paper. We have characterized recently a C-terminally truncated α2δ-1 construct, α2δ-1ΔC, and found that, despite loss of its membrane anchor, it still shows a partial ability to increase calcium currents [Kadurin, Alvarez-Laviada, Ng, Walker-Gray, D’Arco, Fadel, Pratt and Dolphin (2012) J. Biol. Chem. 1287, 33554–33566]. We now find that PrP does not inhibit CaV2.1/β currents formed with α2δ-1ΔC, rather than α2δ-1. It is possible that PrP and α2δ-1 compete for GPI-anchor intermediates or trafficking pathways, or that interaction between PrP and α2δ-1 requires association in cholesterol-rich membrane microdomains. Our additional finding that CaV2.1/β1b/α2δ-1 currents were inhibited by GPI–GFP, but not cytosolic GFP, indicates that competition for limited GPI-anchor intermediates or trafficking pathways may be involved in PrP suppression of α2δ subunit function. PMID:24329154

Clot lysis time in platelet-rich plasma: method assessment, comparison with assays in platelet-free and platelet-poor plasmas, and response to tranexamic acid.

PubMed

Panes, Olga; Padilla, Oslando; Matus, Valeria; Sáez, Claudia G; Berkovits, Alejandro; Pereira, Jaime; Mezzano, Diego

2012-01-01

Fibrinolysis dysfunctions cause bleeding or predisposition to thrombosis. Platelets contain several factors of the fibrinolytic system, which could up or down regulate this process. However, the temporal relationship and relative contributions of plasma and platelet components in clot lysis are mostly unknown. We developed a clot lysis time (CLT) assay in platelet-rich plasma (PRP-CLT, with and without stimulation) and compared it to a similar one in platelet-free plasma (PFP) and to another previously reported test in platelet-poor plasma (PPP). We also studied the differential effects of a single dose of tranexamic acid (TXA) on these tests in healthy subjects. PFP- and PPP-CLT were significantly shorter than PRP-CLT, and the three assays were highly correlated (p < 0.0001). PFP- and PPP-, but more significantly PRP-CLT, were positively correlated with age and plasma PAI-1, von Willebrand factor, fibrinogen, LDL-cholesterol, and triglycerides (p < 0.001). All these CLT assays had no significant correlations with platelet aggregation/secretion, platelet counts, and pro-coagulant tests to explore factor X activation by platelets, PRP clotting time, and thrombin generation in PRP. Among all the studied variables, PFP-CLT was independently associated with plasma PAI-1, LDL-cholesterol, and triglycerides and, additionally, stimulated PRP-CLT was also independently associated with plasma fibrinogen. A single 1 g dose of TXA strikingly prolonged all three CLTs, but in contrast to the results without the drug, the lysis times were substantially shorter in non-stimulated or stimulated PRP than in PFP and PPP. This standardized PRP-CLT may become a useful tool to study the role of platelets in clot resistance and lysis. Our results suggest that initially, the platelets enmeshed in the clot slow down the fibrinolysis process. However, the increased clot resistance to lysis induced by TXA is overcome earlier in platelet-rich clots than in PFP or PPP clots. This is likely explained by the display of platelet pro-fibrinolytic effects. Focused research is needed to disclose the mechanisms for the relationship between CLT and plasma cholesterol and its potential pathophysiologic and clinical relevance.

CHOROIDAL THICKNESS CHANGES IN PROLIFERATIVE DIABETIC RETINOPATHY TREATED WITH PANRETINAL PHOTOCOAGULATION VERSUS PANRETINAL PHOTOCOAGULATION WITH INTRAVITREAL BEVACIZUMAB.

PubMed

Roohipoor, Ramak; Sharifian, Elaheh; Ghassemi, Fariba; Riazi-Esfahani, Mohammad; Karkhaneh, Reza; Fard, Masoud Aghsaei; Zarei, Mohammad; Modjtahedi, Bobeck S; Moghimi, Sasan

2016-10-01

To compare choroidal thickness (CT) and retinal thickness (RT) between eyes with proliferative diabetic retinopathy treated with panretinal photocoagulation (PRP) or PRP with intravitreal bevacizumab (PRP + IVB). Thirty-three patients with proliferative diabetic retinopathy were randomized to have one eye treated with PRP and the other with PRP + IVB. Change in CT was compared with baseline using enhanced depth imaging-optical coherence tomography at baseline and Months 1, 3, 6, and 10 after treatment. Change in RT was similarly assessed using spectral domain optical coherence tomography. Changes in both CT and RT were assessed in all nine macular areas as defined by Early Treatment Diabetic Retinopathy Study subfields. The PRP + IVB group had a significant decrease in subfoveal CT at 3 and 10 months (323.9 ± 62 μm at baseline vs. 320.7 ± 64.8 μm at Month 3 [P = 0.024] and 304.7 ± 65.6 μm at Month 10 [P = 0.003]). Subfoveal CT significantly decreased at 10 months compared with baseline in the PRP group (320.8 ± 57.7 at baseline to 297 ± 66.3 μm at 10 months, P = 0.01). Subfoveal CT was not significantly different between the 2 groups at 10 months. The best-corrected visual acuity did not change after treatment in the two groups, and there was no correlation between BCVA and CT changes (r = 0.222, P = 0.37 in the PRP group and r = 0.387, P = 0.12 in the PRP + IVB group). Significant increases in RT were seen in the PRP + IVB group at 6 months and in the PRP group at Months 1, 3, 6, and 10. A correlation between changes in CT and RT was only seen in the PRP group at 10 months after treatment. Eyes with proliferative diabetic retinopathy treated with PRP + IVB and PRP both had significant reduction in CT at 10 months; however, the eyes that were also treated with IVB also underwent an earlier but transient reduction at 3 months. Patients treated with IVB underwent less increase in RT.

Preparing Platelet-Rich Plasma with Whole Blood Harvested Intraoperatively During Spinal Fusion.

PubMed

Shen, Bin; Zhang, Zheng; Zhou, Ning-Feng; Huang, Yu-Feng; Bao, Yu-Jie; Wu, De-Sheng; Zhang, Ya-Dong

2017-07-22

BACKGROUND Platelet-rich plasma (PRP) has gained growing popularity in use in spinal fusion procedures in the last decade. Substantial intraoperative blood loss is frequently accompanied with spinal fusion, and it is unknown whether blood harvested intraoperatively qualifies for PRP preparation. MATERIAL AND METHODS Whole blood was harvested intraoperatively and venous blood was collected by venipuncture. Then, we investigated the platelet concentrations in whole blood and PRP, the concentration of growth factors in PRP, and the effects of PRP on the proliferation and viability of human bone marrow-derived mesenchymal stem cells (HBMSCs). RESULTS Our results revealed that intraoperatively harvested whole blood and whole blood collected by venipuncture were similar in platelet concentration. In addition, PRP formulations prepared from both kinds of whole blood were similar in concentration of platelet and growth factors. Additional analysis showed that the similar concentrations of growth factors resulted from the similar platelet concentrations of whole blood and PRP between the two groups. Moreover, these two kinds of PRP formulations had similar effects on promoting cell proliferation and enhancing cell viability. CONCLUSIONS Therefore, intraoperatively harvested whole blood may be a potential option for preparing PRP spinal fusion.

PRP19 transforms into a sensor of RPA-ssDNA after DNA damage and drives ATR activation via a ubiquitin-mediated circuitry.

PubMed

Maréchal, Alexandre; Li, Ju-Mei; Ji, Xiao Ye; Wu, Ching-Shyi; Yazinski, Stephanie A; Nguyen, Hai Dang; Liu, Shizhou; Jiménez, Amanda E; Jin, Jianping; Zou, Lee

2014-01-23

PRP19 is a ubiquitin ligase involved in pre-mRNA splicing and the DNA damage response (DDR). Although the role for PRP19 in splicing is well characterized, its role in the DDR remains elusive. Through a proteomic screen for proteins that interact with RPA-coated single-stranded DNA (RPA-ssDNA), we identified PRP19 as a sensor of DNA damage. PRP19 directly binds RPA and localizes to DNA damage sites via RPA, promoting RPA ubiquitylation in a DNA-damage-induced manner. PRP19 facilitates the accumulation of ATRIP, the regulatory partner of the ataxia telangiectasia mutated and Rad3-related (ATR) kinase, at DNA damage sites. Depletion of PRP19 compromised the phosphorylation of ATR substrates, recovery of stalled replication forks, and progression of replication forks on damaged DNA. Importantly, PRP19 mutants that cannot bind RPA or function as an E3 ligase failed to support the ATR response, revealing that PRP19 drives ATR activation by acting as an RPA-ssDNA-sensing ubiquitin ligase during the DDR. Copyright © 2014 Elsevier Inc. All rights reserved.

Genetic Studies of the Prp17 Gene of Saccharomyces Cerevisiae: A Domain Essential for Function Maps to a Nonconserved Region of the Protein

PubMed Central

Seshadri, V.; Vaidya, V. C.; Vijayraghavan, U.

1996-01-01

The PRP17 gene product is required for the second step of pre-mRNA splicing reactions. The C-terminal half of this protein bears four repeat units with homology to the β transducin repeat. Missense mutations in three temperature-sensitive prp17 mutants map to a region in the N-terminal half of the protein. We have generated, in vitro, 11 missense alleles at the β transducin repeat units and find that only one affects function in vivo. A phenotypically silent missense allele at the fourth repeat unit enhances the slow-growing phenotype conferred by an allele at the third repeat, suggesting an interaction between these domains. Although many missense mutations in highly conserved amino acids lack phenotypic effects, deletion analysis suggests an essential role for these units. Only mutations in the N-terminal nonconserved domain of PRP17 are synthetically lethal in combination with mutations in PRP16 and PRP18, two other gene products required for the second splicing reaction. A mutually allele-specific interaction between prp17 and snr7, with mutations in U5 snRNA, was observed. We therefore suggest that the functional region of Prp17p that interacts with Prp18p, Prp16p, and U5 snRNA is in the N terminal region of the protein. PMID:8722761

Freeze-Dried Platelet-Rich Plasma Accelerates Bone Union with Adequate Rigidity in Posterolateral Lumbar Fusion Surgery Model in Rats

NASA Astrophysics Data System (ADS)

Shiga, Yasuhiro; Orita, Sumihisa; Kubota, Go; Kamoda, Hiroto; Yamashita, Masaomi; Matsuura, Yusuke; Yamauchi, Kazuyo; Eguchi, Yawara; Suzuki, Miyako; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Fujimoto, Kazuki; Abe, Koki; Kanamoto, Hirohito; Inoue, Masahiro; Kinoshita, Hideyuki; Aoki, Yasuchika; Toyone, Tomoaki; Furuya, Takeo; Koda, Masao; Takahashi, Kazuhisa; Ohtori, Seiji

2016-11-01

Fresh platelet-rich plasma (PRP) accelerates bone union in rat model. However, fresh PRP has a short half-life. We suggested freeze-dried PRP (FD-PRP) prepared in advance and investigated its efficacy in vivo. Spinal posterolateral fusion was performed on 8-week-old male Sprague-Dawley rats divided into six groups based on the graft materials (n = 10 per group): sham control, artificial bone (A hydroxyapatite-collagen composite) -alone, autologous bone, artificial bone + fresh-PRP, artificial bone + FD-PRP preserved 8 weeks, and artificial bone + human recombinant bone morphogenetic protein 2 (BMP) as a positive control. At 4 and 8 weeks after the surgery, we investigated their bone union-related characteristics including amount of bone formation, histological characteristics of trabecular bone at remodeling site, and biomechanical strength on 3-point bending. Comparable radiological bone union was confirmed at 4 weeks after surgery in 80% of the FD-PRP groups, which was earlier than in other groups (p < 0.05). Histologically, the trabecular bone had thinner and more branches in the FD-PRP. Moreover, the biomechanical strength was comparable to that of autologous bone. FD-PRP accelerated bone union at a rate comparable to that of fresh PRP and BMP by remodeling the bone with thinner, more tangled, and rigid trabecular bone.

Freeze-Dried Platelet-Rich Plasma Accelerates Bone Union with Adequate Rigidity in Posterolateral Lumbar Fusion Surgery Model in Rats

PubMed Central

Shiga, Yasuhiro; Orita, Sumihisa; Kubota, Go; Kamoda, Hiroto; Yamashita, Masaomi; Matsuura, Yusuke; Yamauchi, Kazuyo; Eguchi, Yawara; Suzuki, Miyako; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Fujimoto, Kazuki; Abe, Koki; Kanamoto, Hirohito; Inoue, Masahiro; Kinoshita, Hideyuki; Aoki, Yasuchika; Toyone, Tomoaki; Furuya, Takeo; Koda, Masao; Takahashi, Kazuhisa; Ohtori, Seiji

2016-01-01

Fresh platelet-rich plasma (PRP) accelerates bone union in rat model. However, fresh PRP has a short half-life. We suggested freeze-dried PRP (FD-PRP) prepared in advance and investigated its efficacy in vivo. Spinal posterolateral fusion was performed on 8-week-old male Sprague-Dawley rats divided into six groups based on the graft materials (n = 10 per group): sham control, artificial bone (A hydroxyapatite–collagen composite) –alone, autologous bone, artificial bone + fresh-PRP, artificial bone + FD-PRP preserved 8 weeks, and artificial bone + human recombinant bone morphogenetic protein 2 (BMP) as a positive control. At 4 and 8 weeks after the surgery, we investigated their bone union–related characteristics including amount of bone formation, histological characteristics of trabecular bone at remodeling site, and biomechanical strength on 3-point bending. Comparable radiological bone union was confirmed at 4 weeks after surgery in 80% of the FD-PRP groups, which was earlier than in other groups (p < 0.05). Histologically, the trabecular bone had thinner and more branches in the FD-PRP. Moreover, the biomechanical strength was comparable to that of autologous bone. FD-PRP accelerated bone union at a rate comparable to that of fresh PRP and BMP by remodeling the bone with thinner, more tangled, and rigid trabecular bone. PMID:27833116

Comparison of collagen matrix treatment impregnated with platelet rich plasma vs bone marrow.

PubMed

Minamimura, Ai; Ichioka, Shigeru; Sano, Hitomi; Sekiya, Naomi

2014-02-01

This study has reported the efficacy of an autologous bone marrow-impregnated collagen matrix experimentally and clinically. Then, it reflected that platelet rich plasma (PRP) was as good a source of growth factors as bone marrow and available in a less invasive procedure. This study aimed to compare the efficacy of a PRP-impregnated collagen matrix with that of a bone marrow-impregnated collagen matrix by quantifying wound size and capillary density using genetically diabetic db/db mice. Bone marrow cells were obtained from femurs of ddy mice. Then, a small amount of collagen matrix was immersed in bone marrow suspension. This is called a bone marrow-impregnated collagen matrix. PRP was obtained from healthy human blood and a small amount of collagen matrix was immersed in PRP. This is called a PRP-impregnated collagen matrix. A bone marrow-impregnated collagen matrix and PRP-impregnated collagen matrix were applied to excisional skin wounds on a genetically healing-impaired mouse (n = 6) and wounds were evaluated 6 days after the procedure. Wounds were divided into two groups: PRP (n = 6), in which a PRP-impregnated collagen matrix was applied; and bone marrow (n = 6), in which collagen immersed in a bone marrow suspension was applied. There was no significant difference between the PRP and bone-marrow groups in the rate of vascular density increase or wound size decrease. The present study suggested that the PRP-impregnated collagen matrix promotes repair processes at least as strongly as the bone marrow-impregnated collagen matrix. Given lower invasiveness, the PRP-impregnated collagen matrix would have advantages in clinical use.

Structural and functional analysis of the human spliceosomal DEAD-box helicase Prp28

DOE Office of Scientific and Technical Information (OSTI.GOV)

Möhlmann, Sina; Mathew, Rebecca; Neumann, Piotr

The crystal structure of the helicase domain of the human spliceosomal DEAD-box protein Prp28 was solved by SAD. The binding of ADP and ATP by Prp28 was studied biochemically and analysed with regard to the crystal structure. The DEAD-box protein Prp28 is essential for pre-mRNA splicing as it plays a key role in the formation of an active spliceosome. Prp28 participates in the release of the U1 snRNP from the 5′-splice site during association of the U5·U4/U6 tri-snRNP, which is a crucial step in the transition from a pre-catalytic spliceosome to an activated spliceosome. Here, it is demonstrated that themore » purified helicase domain of human Prp28 (hPrp28ΔN) binds ADP, whereas binding of ATP and ATPase activity could not be detected. ATP binding could not be observed for purified full-length hPrp28 either, but within an assembled spliceosomal complex hPrp28 gains ATP-binding activity. In order to understand the structural basis for the ATP-binding deficiency of isolated hPrp28, the crystal structure of hPrp28ΔN was determined at 2.0 Å resolution. In the crystal the helicase domain adopts a wide-open conformation, as the two RecA-like domains are extraordinarily displaced from the productive ATPase conformation. Binding of ATP is hindered by a closed conformation of the P-loop, which occupies the space required for the γ-phosphate of ATP.« less

Cell Biology Approaches to Studying Prion Diseases.

PubMed

Priola, Suzette A

2017-01-01

During the course of prion infection, the normally soluble and protease-sensitive mammalian prion protein (PrP C ) is refolded into an insoluble, partially protease-resistant, and infectious form called PrP Sc . The conformational conversion of PrP C to PrP Sc is a critical event during prion infection and is essential for the production of prion infectivity. This chapter briefly summarizes the ways in which cell biological approaches have enhanced our understanding of how PrP contributes to different aspects of prion pathogenesis.

Platelet rich plasma, stromal vascular fraction and autologous conditioned serum in treatment of knee osteoarthritis.

PubMed

Fotouhi, Ali; Maleki, Arash; Dolati, Sanam; Aghebati-Maleki, Ali; Aghebati-Maleki, Leili

2018-08-01

Osteoarthritis (OA) is a multifactorial chronic disease, causing several problems on patients, hygiene and community care systems. Conventional therapies, such as non-pharmacological mediations, systemic drug treatment and intra-articular therapies are applying previously; however, controlling and management approaches of the disease mainly remain insufficient. Injections of intra-articular therapies directly into the joint evade conservative obstacles to joint entry, rise bioavailability and minor systemic toxicity. Current progresses in osteoarthritis management have designed better diversity of treatment approaches. Innovative treatments, such as autologous blood products and mesenchymal stem cells, are in progress. Platelet-rich plasma (PRP) is one of the several novel therapeutic approaches that stay to progress in the field of orthopedic medicine. Stromal vascular fraction (SVF) comprises a lesser amount of mesenchymal stem cells and is a treatment for OA and cartilage damage. Based on novel opinions, an innovative therapy by autologous conditioned serum (ACS) from the whole blood was settled. The inoculation of ACS into tissues has revealed clinical efficacy for the treatment of osteoarthritis and muscle injuries. Here, we make available historical perspective of PRP, SVF, and ACS and the other existing researches on using PRP, SVF and ACS for the treatment of knee OA. In conclusion, in current years, OA stem cell therapy has rapidly progressed, with optimistic consequences in animals and human studies. Additionally, PRP, SVF and ASC injection seem to be accompanied with numerous favorable results for treatment of patients with OA. Copyright © 2018. Published by Elsevier Masson SAS.

Augmenting tendon and ligament repair with platelet-rich plasma (PRP)

PubMed Central

Yuan, Ting; Zhang, Chang-Qing; Wang, James H-C.

2013-01-01

Summary Tendon and ligament injuries (TLI) commonly occur in athletes and non-athletes alike, and remarkably debilitate patients’ athletic and personal abilities. Current clinical treatments, such as reconstruction surgeries, do not adequately heal these injuries and often result in the formation of scar tissue that is prone to re-injury. Platelet-rich plasma (PRP) is a widely used alternative option that is also safe because of its autologous nature. PRP contains a number of growth factors that are responsible for its potential to heal TLIs effectively. In this review, we provide a comprehensive report on PRP. While basic science studies in general indicate the potential of PRP to treat TLIs effectively, a review of existing literature on the clinical use of PRP for the treatment of TLIs indicates a lack of consensus due to varied treatment outcomes. This suggests that current PRP treatment protocols for TLIs may not be optimal, and that not all TLIs may be effectively treated with PRP. Certainly, additional basic science studies are needed to develop optimal treatment protocols and determine those TLI conditions that can be treated effectively. PMID:24367773

A phosphorylation-and-ubiquitylation circuitry driving ATR activation and homologous recombination

PubMed Central

Dubois, Jean-Christophe; Yates, Maïlyn; Gaudreau-Lapierre, Antoine; Clément, Geneviève; Cappadocia, Laurent; Gaudreau, Luc

2017-01-01

Abstract RPA-coated single-stranded DNA (RPA–ssDNA), a nucleoprotein structure induced by DNA damage, promotes ATR activation and homologous recombination (HR). RPA is hyper-phosphorylated and ubiquitylated after DNA damage. The ubiquitylation of RPA by PRP19 and RFWD3 facilitates ATR activation and HR, but how it is stimulated by DNA damage is still unclear. Here, we show that RFWD3 binds RPA constitutively, whereas PRP19 recognizes RPA after DNA damage. The recruitment of PRP19 by RPA depends on PIKK-mediated RPA phosphorylation and a positively charged pocket in PRP19. An RPA32 mutant lacking phosphorylation sites fails to recruit PRP19 and support RPA ubiquitylation. PRP19 mutants unable to bind RPA or lacking ubiquitin ligase activity also fail to support RPA ubiquitylation and HR. These results suggest that RPA phosphorylation enhances the recruitment of PRP19 to RPA–ssDNA and stimulates RPA ubiquitylation through a process requiring both PRP19 and RFWD3, thereby triggering a phosphorylation-ubiquitylation circuitry that promotes ATR activation and HR. PMID:28666352

Considerations for the use of platelet-rich plasma in orthopedics.

PubMed

McCarrel, Taralyn M; Mall, Nathan A; Lee, Andrew S; Cole, Brian J; Butty, Davietta C; Fortier, Lisa A

2014-08-01

The use of platelet-rich plasma (PRP) is expanding to numerous medical fields, including orthopedic surgery and sports medicine. The popularity of this new treatment option has prompted a rapid increase in research endeavors; however, the differences in application technique and the composition of PRP have made it difficult to compare results or make any firm conclusions regarding efficacy. The purpose of this article is twofold. First, to recommend details that should be provided in basic science and clinical PRP studies to allow meaningful comparisons between studies which may lead to a better understanding of efficacy. Second, to provide an understanding of the different PRP preparations and their clinical relevance. There are biochemical rationales for the use of PRP because it addresses several aspects of the healing process, including cell proliferation and tissue matrix regeneration, inflammation, nociception, infection, and hemostasis, all of which will be addressed. Given the current understanding of the importance the composition of PRP plays in tissue regeneration, it is likely that our future understanding of PRP will dictate 'customizing' the PRP preparation to the specific pathology of interest. The potential complications following PRP use are minor, and thus it appears to be a safe treatment option with a variety of potentially beneficial effects to injured musculoskeletal tissues.

Can platelet-rich plasma (PRP) improve bone healing? A comparison between the theory and experimental outcomes.

PubMed

Malhotra, Angad; Pelletier, Matthew H; Yu, Yan; Walsh, William R

2013-02-01

The increased concentration of platelets within platelet-rich plasma (PRP) provides a vehicle to deliver supra-physiologic concentrations of growth factors to an injury site, possibly accelerating or otherwise improving connective tissue regeneration. This potential benefit has led to the application of PRP in several applications; however, inconsistent results have limited widespread adoption in bone healing. This review provides a core understanding of the bone healing mechanisms, and corresponds this to the factors present in PRP. In addition, the current state of the art of PRP preparation, the key aspects that may influence its effectiveness, and treatment outcomes as they relate specifically to bone defect healing are presented. Although PRP does have a sound scientific basis, its use for bone healing appears only beneficial when used in combination with osteoconductive scaffolds; however, neither allograft nor autograft appear to be appropriate carriers. Aggressive processing techniques and very high concentrations of PRP may not improve healing outcomes. Moreover, many other variables exist in PRP preparation and use that influence its efficacy; the effect of these variables should be understood when considering PRP use. This review includes the essentials of what has been established, what is currently missing in the literature, and recommendations for future directions.

Effects of different concentrations of Platelet-rich Plasma and Platelet-Poor Plasma on vitality and differentiation of autologous Adipose tissue-derived stem cells.

PubMed

Felthaus, Oliver; Prantl, Lukas; Skaff-Schwarze, Mona; Klein, Silvan; Anker, Alexandra; Ranieri, Marco; Kuehlmann, Britta

2017-01-01

Autologous fat grafts and adipose-derived stem cells (ASCs) can be used to treat soft tissue defects. However, the results are inconsistent and sometimes comprise tissue resorption and necrosis. This might be due to insufficient vascularization. Platelet-rich plasma (PRP) is a source of concentrated autologous platelets. The growth factors and cytokines released by platelets can facilitate angiogenesis. The simultaneous use of PRP might improve the regeneration potential of fat grafts. The optimal ratio has yet to be elucidated. A byproduct of PRP preparation is platelet-poor plasma (PPP). In this study we investigated the influence of different concentrations of PRP on the vitality and differentiation of ASCs. We processed whole blood with the Arthrex Angel centrifuge and isolated ASCs from the same donor. We tested the effects of different PRP and PPP concentrations on the vitality using resazurin assays and the differentiation of ASCs using oil-red staining. Both cell vitality and adipogenic differentiation increase to a concentration of 10% to 20% PRP. With a PRP concentration of 30% cell vitality and differentiation decrease. Both PRP and PPP can be used to expand ASCs without xenogeneic additives in cell culture. A PRP concentration above 20% has inhibitory effects.

Bioactivity of freeze-dried platelet-rich plasma in an adsorbed form on a biodegradable polymer material.

PubMed

Nakajima, Yu; Kawase, Tomoyuki; Kobayashi, Mito; Okuda, Kazuhiro; Wolff, Larry F; Yoshie, Hiromasa

2012-01-01

Owing to the necessity for the immediate preparation from patients' blood, autologous platelet-rich plasma (PRP) limits its clinical applicability. To address this concern and respond to emergency care and other unpredictable uses, we have developed a freeze-dried PRP in an adsorbed form on a biodegradable polymer material (Polyglactin 910). On the polymer filaments of PRP mesh, which was prepared by coating the polymer mesh with human fresh PRP and subsequent freeze-drying, platelets were incorporated, and related growth factors were preserved at high levels. This new PRP mesh preparation significantly and reproducibly stimulated the proliferation of human periodontal ligament cells in vitro and neovascularization in a chorioallantoic membrane assay. A full-thickness skin defect model in a diabetic mouse demonstrated the PRP mesh, although prepared from human blood, substantially facilitated angiogenesis, granulation tissue formation, and re-epithelialization without inducing severe inflammation in vivo. These data demonstrate that our new PRP mesh preparation functions as a bioactive material to facilitate tissue repair/regeneration. Therefore, we suggest that this bioactive material, composed of allogeneic PRP, could be clinically used as a promising alternative in emergency care or at times when autologous PRP is not prepared immediately before application.

Prp43p Is a DEAH-Box Spliceosome Disassembly Factor Essential for Ribosome Biogenesis

PubMed Central

Combs, D. Joshua; Nagel, Roland J.; Ares, Manuel; Stevens, Scott W.

2006-01-01

The known function of the DEXH/D-box protein Prp43p is the removal of the U2, U5, and U6 snRNPs from the postsplicing lariat-intron ribonucleoprotein complex. We demonstrate that affinity-purified Prp43p-associated material includes the expected spliceosomal components; however, we also identify several preribosomal complexes that are specifically purified with Prp43p. Conditional prp43 mutant alleles confer a 35S pre-rRNA processing defect, with subsequent depletion of 27S and 20S precursors. Upon a shift to a nonpermissive temperature, both large and small-ribosomal-subunit proteins accumulate in the nucleolus of prp43 mutants. Pulse-chase analysis demonstrates delayed kinetics of 35S, 27S, and 20S pre-rRNA processing with turnover of these intermediates. Microarray analysis of pre-mRNA splicing defects in prp43 mutants shows a very mild effect, similar to that of nonessential pre-mRNA splicing factors. Prp43p is the first DEXH/D-box protein shown to function in both RNA polymerase I and polymerase II transcript metabolism. Its essential function is in its newly characterized role in ribosome biogenesis of both ribosomal subunits, positioning Prp43p to regulate both pre-mRNA splicing and ribosome biogenesis. PMID:16382144

Cellular Prion Protein Combined with Galectin-3 and -6 Affects the Infectivity Titer of an Endogenous Retrovirus Assayed in Hippocampal Neuronal Cells

PubMed Central

Shin, Hae-Young; Goto, Joy J.; Carp, Richard I.; Choi, Eun-Kyoung; Kim, Yong-Sun

2016-01-01

Prion diseases are infectious and fatal neurodegenerative diseases which require the cellular prion protein, PrPC, for development of diseases. The current study shows that the PrPC augments infectivity and plaque formation of a mouse endogenous retrovirus, MuLV. We have established four neuronal cell lines expressing mouse PrPC, PrP+/+; two express wild type PrPC (MoPrPwild) and the other two express mutant PrPC (MoPrPmut). Infection of neuronal cells from various PrP+/+ and PrP-/- (MoPrPKO) lines with MuLV yielded at least three times as many plaques in PrP+/+ than in PrP-/-. Furthermore, among the four PrP+/+ lines, one mutant line, P101L, had at least 2.5 times as many plaques as the other three PrP+/+ lines. Plaques in P101L were four times larger than those in other PrP+/+ lines. Colocalization of PrP and CAgag was seen in MuLV-infected PrP+/+ cells. In the PrP-MuLV interaction, the involvement of galectin-3 and -6 was observed by immunoprecipitation with antibody to PrPC. These results suggest that PrPC combined with galectin-3 and -6 can act as a receptor for MuLV. P101L, the disease form of mutant PrPC results suggest the genetic mutant form of PrPC may be more susceptible to viral infection. PMID:27936017

Membrane Disruption Mechanism of a Prion Peptide (106-126) Investigated by Atomic Force Microscopy, Raman and Electron Paramagnetic Resonance Spectroscopy.

PubMed

Pan, Jianjun; Sahoo, Prasana K; Dalzini, Annalisa; Hayati, Zahra; Aryal, Chinta M; Teng, Peng; Cai, Jianfeng; Rodriguez Gutierrez, Humberto; Song, Likai

2017-05-18

A fragment of the human prion protein spanning residues 106-126 (PrP106-126) recapitulates many essential properties of the disease-causing protein such as amyloidogenicity and cytotoxicity. PrP106-126 has an amphipathic characteristic that resembles many antimicrobial peptides (AMPs). Therefore, the toxic effect of PrP106-126 could arise from a direct association of monomeric peptides with the membrane matrix. Several experimental approaches are employed to scrutinize the impacts of monomeric PrP106-126 on model lipid membranes. Porous defects in planar bilayers are observed by using solution atomic force microscopy. Adding cholesterol does not impede defect formation. A force spectroscopy experiment shows that PrP106-126 reduces Young's modulus of planar lipid bilayers. We use Raman microspectroscopy to study the effect of PrP106-126 on lipid atomic vibrational dynamics. For phosphatidylcholine lipids, PrP106-126 disorders the intrachain conformation, while the interchain interaction is not altered; for phosphatidylethanolamine lipids, PrP106-126 increases the interchain interaction, while the intrachain conformational order remains similar. We explain the observed differences by considering different modes of peptide insertion. Finally, electron paramagnetic resonance spectroscopy shows that PrP106-126 progressively decreases the orientational order of lipid acyl chains in magnetically aligned bicelles. Together, our experimental data support the proposition that monomeric PrP106-126 can disrupt lipid membranes by using similar mechanisms found in AMPs.

Membrane Disruption Mechanism of a Prion Peptide (106-126) Investigated by Atomic Force Microscopy, Raman and Electron Paramagnetic Resonance Spectroscopy

PubMed Central

Pan, Jianjun; Sahoo, Prasana K.; Dalzini, Annalisa; Hayati, Zahra; Aryal, Chinta M.; Teng, Peng; Cai, Jianfeng; Gutierrez, Humberto Rodriguez; Song, Likai

2018-01-01

A fragment of the human prion protein spanning residues 106-126 (PrP106-126) recapitulates many essential properties of the disease-causing protein such as amyloidogenicity and cytotoxicity. PrP106-126 has an amphipathic characteristic that resembles many antimicrobial peptides (AMPs). Therefore, the toxic effect of PrP106-126 could arise from a direct association of monomeric peptides with membrane matrix. Several experimental approaches are employed to scrutinize the impacts of monomeric PrP106-126 on model lipid membranes. Porous defects in planar bilayers are observed by using solution atomic force microscopy. Adding cholesterol does not impede defect formation. Force spectroscopy experiment shows that PrP106-126 reduces Young’s modulus of planar lipid bilayers. We use Raman microspectroscopy to study the effect of PrP106-126 on lipid vibrational dynamics. For phosphatidylcholine lipids, PrP106-126 disorders the intra-chain conformation, while the inter-chain interaction is not altered; for phosphatidylethanolamine lipids, PrP106-126 increases the inter-chain interaction, while the intra-chain conformational order remains similar. We explain the observed differences by considering different modes of peptide insertion. Finally, electron paramagnetic resonance spectroscopy shows that PrP106-126 progressively decreases the orientational order of lipid acyl chains in magnetically aligned bicelles. Together, our experimental data support the proposition that monomeric PrP106-126 can disrupt lipid membranes by using similar mechanisms found in AMPs. PMID:28459565

Characterization of barley Prp1 gene and its expression during seed development and under abiotic stress.

PubMed

Jiang, Qian-Tao; Liu, Tao; Ma, Jian; Wei, Yu-Ming; Lu, Zhen-Xiang; Lan, Xiu-Jin; Dai, Shou-Fen; Zheng, You-Liang

2011-10-01

The pre-mRNA processing (Prp1) gene encodes a spliceosomal protein. It was firstly identified in fission yeast and plays a regular role during spliceosome activation and cell cycle. Plant Prp1 genes have only been identified from rice, Sorghum and Arabidopsis thaliana. In this study, we reported the identification and isolation of a novel Prp1 gene from barley, and further explored its expressional pattern by using real-time quantitative RTPCR, promoter prediction and analysis of microarray data. The putative barley Prp1 protein has a similar primary structure features to those of other known Prp1 protein in this family. The results of amino acid comparison indicated that Prp1 protein of barley and other plant species has a highly conserved 30 termnal region while their 50 sequences greatly varied. The results of expressional analysis revealed that the expression level of barley Prp1 gene is always stable in different vegetative tissues, except it is up-regulated at the mid- and late stages of seed development or under the condition of cold stress. This kind of expressional pattern for barley Prp1 is also supported by our results of comparison of microarray data from barley, rice and Arabidopsis. For the molecular mechanism of its expressional pattern, we conclude that the expression of Prp1 gene may be up-regulated by the increase of pre-mRNAs and not be constitutive or ubiquitous.

Combination of herbal extracts and platelet-rich plasma induced dermal papilla cell proliferation: involvement of ERK and Akt pathways.

PubMed

Rastegar, Hosein; Ahmadi Ashtiani, Hamidreza; Aghaei, Mahmoud; Ehsani, Amirohushang; Barikbin, Behrooz

2013-06-01

Recently, platelet-rich plasma (PRP) has attracted attention in various medical fields, including plastic surgery, treatment for problematic wounds, and dermatology. Specifically, PRP has been tested during hair transplantation to reduce swelling and pain and to increase hair density. We examined the effects of PRP and herbal extracts combination in order to identify potential stimulants of hair growth. PRP was prepared using the double-spin method and applied to dermal papilla cells (DPCs). MTT viability test and BrdU cell proliferation assay were used to study the effect of herbal extracts and PRP on proliferation of DPCs. To understand the mechanisms of herbal extracts and PRP involved in the regulation of hair growth, we evaluated signaling pathways and measured the expressions of ERK and Akt, by Western blot. Combination of herbal extracts and PRP was found to induce significant proliferation of human DPCs at concentrations ranging from 1.5% to 4.5%. The present study shows that herbal extracts and PRP affect the expressions of extracellular signal-regulated kinase (ERK) and Akt in DPCs. In this study, we have shown that combination of herbal extracts and PRP plays an active role in promoting the proliferation of human dermal papilla (DP) cells via the regulation of ERK and Akt proteins, and this may be applicable to the future development of herbal extracts and PRP combination therapeutics to enhance hair growth. © 2013 Wiley Periodicals, Inc.

Platelet-Rich Plasma Injection With Arthroscopic Acromioplasty for Chronic Rotator Cuff Tendinopathy: A Randomized Controlled Trial.

PubMed

Carr, Andrew J; Murphy, Richard; Dakin, Stephanie G; Rombach, Ines; Wheway, Kim; Watkins, Bridget; Franklin, Sarah L

2015-12-01

Platelet-rich plasma (PRP) has been proposed to augment tendon healing through improving tissue structure during the initial repair phase. To investigate both the clinical and tissue effects of the coapplication of PRP injection with arthroscopic acromioplasty (AA) in patients with chronic rotator cuff tendinopathy. Randomized controlled trial; Level of evidence, 1. The study comprised 60 randomized patients diagnosed with rotator cuff tendinopathy (55% women) aged between 35 and 75 years. Patients were randomized to AA alone or in combination with an injection of autologous PRP into the subacromial bursa (AA + PRP). Efficacy of treatment was assessed by analysis of patient-reported outcomes up to 2 years after treatment (Oxford Shoulder Score [OSS]) and by analysis of tendon biopsy specimens taken 12 weeks after treatment. There was no significant difference in the OSS between AA alone and AA + PRP at any time point in the study. From 12 weeks onward, there was a significant increase in the OSS for both groups compared with their baseline scores (P < .001). Bonar scoring determined no significant change in tissue structure with the coapplication of PRP compared with surgery alone. The number of blood vessels and tendon cellularity were significantly decreased in tissue biopsy specimens taken from PRP-treated patients. The expression of p53-positive apoptotic cells increased after AA + PRP but decreased after AA alone. Arthroscopic acromioplasty significantly improves long-term clinical outcomes up to 2 years. The coapplication of PRP did not affect clinical outcomes. PRP significantly alters the tissue characteristics in tendons after surgery with reduced cellularity and vascularity and increased levels of apoptosis. The coapplication of PRP did not improve clinical outcomes and may have potential deleterious effects on healing tendons. ISRCTN 10464365. © 2015 The Author(s).

Effect of activated autologous platelet-rich plasma on proliferation and osteogenic differentiation of human adipose-derived stem cells in vitro

PubMed Central

Xu, Fang-Tian; Li, Hong-Mian; Yin, Qing-Shui; Liang, Zhi-Jie; Huang, Min-Hong; Chi, Guang-Yi; Huang, Lu; Liu, Da-Lie; Nan, Hua

2015-01-01

To investigate whether activated autologous platelet-rich plasma (PRP) can promote proliferation and osteogenic differentiation of human adipose-derived stem cells (hASCs) in vitro. hASCs were isolated from lipo-aspirates, and characterized by specific cell markers and multilineage differentiation capacity after culturing to the 3rd passage. PRP was collected and activated from human peripheral blood of the same patient. Cultured hASCs were treated with normal osteogenic inductive media alone (group A, control) or osteogenic inductive media plus 5%, 10%, 20%, 40%PRP (group B, C, D, E, respectively). Cell proliferation was assessed by CCK-8 assay. mRNA expression of osteogenic marker genes including alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OCN) and core binding factor alpha 1 (Cbfa1) were determined by Real-Time Quantitative PCR Analysis (qPCR). Data revealed that different concentrations of activated autologous PRP significantly promoted hASCs growth in the proliferation phase compared to the without PRP group and resulted in a dose-response relationship. At 7-d and 14-d time point of the osteogenic induced stage, ALP activity in PRP groups gradually increased with the increasing of concentrations of PRP and showed that dose-response relationship. At 21-d time point of the osteogenic induced stage, PRP groups make much more mineralization and mRNA relative expression of ALP, OPN, OCN and Cbfa1 than that without PRP groups and show that dose-response relationship. This study indicated that different concentrations of activated autologous PRP can promote cell proliferation at earlier stage and promote osteogenic differentiation at later stage of hASCs in vitro. Moreover, it displayed a dose-dependent effect of activated autologous PRP on cell proliferation and osteogenic differentiation of hASCs in vitro. PMID:25901195

Improved fat graft survival by different volume fractions of platelet-rich plasma and adipose-derived stem cells.

PubMed

Li, Feng; Guo, Weihua; Li, Kun; Yu, Mei; Tang, Wei; Wang, Hang; Tian, Weidong

2015-03-01

The success of soft-tissue augmentation is offset by the low survival rates of grafted fat tissue. Research shows that adipose-derived stem cells (ASCs) and platelet-rich plasma (PRP) are beneficial to tissue healing. To evaluate the long-term effects of different volume fractions of PRP combined with ASCs on fat graft. ASCs were isolated from human fat tissue, and PRP was obtained from human blood. Cell count kit-8 and real-time polymerase chain reaction (PCR) were used to evaluate the influence of PRP (0%, 10%, 20%, and 30%; volume/volume [v/v]) in medium on ASC proliferation and adipogenic differentiation, respectively. A novel lipoinjection consisting of granular fat, PRP, and ASCs was subcutaneously transplanted into nude mice. The grafts were volumetrically and histologically evaluated 10, 30, 60, and 90 days after transplantation. The addition of PRP improved ASC proliferation. Expression of adipogenic-related genes, peroxisome proliferator-activated receptor-γ, lipoprotein lipase, and adipophilin were up-regulated in PRP-induced ASCs. Compared with other groups, granular fat grafts formed with 20% (v/v) and 30% (v/v) PRP significantly improved residual volumes. More intact adipocytes and capillary formation, but less vacuolization, were observed in the 20% (v/v) and 30% (v/v) PRP groups at 30, 60, and 90 days. However, no significant difference was observed between the 20% (v/v) and 30% (v/v) PRP groups in retaining fat grafts and improving histology. Fat grafting with 20% (v/v) PRP and ASCs constitutes an appropriate transplantation strategy for improving graft survival and provides a potential approach for soft-tissue restoration in plastic and reconstructive surgery. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

Splicing Factor Prp8 Interacts With NES(AR) and Regulates Androgen Receptor in Prostate Cancer Cells.

PubMed

Wang, Dan; Nguyen, Minh M; Masoodi, Khalid Z; Singh, Prabhpreet; Jing, Yifeng; O'Malley, Katherine; Dar, Javid A; Dhir, Rajiv; Wang, Zhou

2015-12-01

Androgen receptor (AR) plays a pivotal role in the development of primary as well as advanced castration-resistant prostate cancer. Previous work in our lab identified a novel nuclear export signal (NES) (NES(AR)) in AR ligand-binding domain essential for AR nucleocytoplasmic trafficking. By characterizing the localization of green fluorescence protein (GFP)-tagged NES(AR), we designed and executed a yeast mutagenesis screen and isolated 7 yeast mutants that failed to display the NES(AR) export function. One of those mutants was identified as the splicing factor pre-mRNA processing factor 8 (Prp8). We further showed that Prp8 could regulate NES(AR) function using short hairpin RNA knockdown of Prp8 coupled with a rapamycin export assay in mammalian cells and knockdown of Prp8 could induce nuclear accumulation of GFP-tagged AR in PC3 cells. Prp8 expression was decreased in castration-resistant LuCaP35 xenograft tumors as compared with androgen-sensitive xenografts. Laser capture microdissection and quantitative PCR showed Prp8 mRNA levels were decreased in human prostate cancer specimens with high Gleason scores. In prostate cancer cells, coimmunoprecipitation and deletion mutagenesis revealed a physical interaction between Prp8 and AR mainly mediated by NES(AR). Luciferase assay with prostate specific antigen promoter-driven reporter demonstrated that Prp8 regulated AR transcription activity in prostate cancer cells. Interestingly, Prp8 knockdown also increased polyubiquitination of endogenous AR. This may be 1 possible mechanism by which it modulates AR activity. These results show that Prp8 is a novel AR cofactor that interacts with NES(AR) and regulates AR function in prostate cancer cells.

Ionic mechanisms of action of prion protein fragment PrP(106-126) in rat basal forebrain neurons.

PubMed

Alier, Kwai; Li, Zongming; Mactavish, David; Westaway, David; Jhamandas, Jack H

2010-08-01

Prion diseases are neurodegenerative disorders that are characterized by the presence of the misfolded prion protein (PrP). Neurotoxicity in these diseases may result from prion-induced modulation of ion channel function, changes in neuronal excitability, and consequent disruption of cellular homeostasis. We therefore examined PrP effects on a suite of potassium (K(+)) conductances that govern excitability of basal forebrain neurons. Our study examined the effects of a PrP fragment [PrP(106-126), 50 nM] on rat neurons using the patch clamp technique. In this paradigm, PrP(106-126) peptide, but not the "scrambled" sequence of PrP(106-126), evoked a reduction of whole-cell outward currents in a voltage range between -30 and +30 mV. Reduction of whole-cell outward currents was significantly attenuated in Ca(2+)-free external media and also in the presence of iberiotoxin, a blocker of calcium-activated potassium conductance. PrP(106-126) application also evoked a depression of the delayed rectifier (I(K)) and transient outward (I(A)) potassium currents. By using single cell RT-PCR, we identified the presence of two neuronal chemical phenotypes, GABAergic and cholinergic, in cells from which we recorded. Furthermore, cholinergic and GABAergic neurons were shown to express K(v)4.2 channels. Our data establish that the central region of PrP, defined by the PrP(106-126) peptide used at nanomolar concentrations, induces a reduction of specific K(+) channel conductances in basal forebrain neurons. These findings suggest novel links between PrP signalling partners inferred from genetic experiments, K(+) channels, and PrP-mediated neurotoxicity.

A randomized controlled experimental study of the efficacy of platelet-rich plasma and hyaluronic acid for the prevention of adhesion formation in a rat uterine horn model.

PubMed

Oz, Murat; Cetinkaya, Nilufer; Bas, Sevda; Korkmaz, Elmas; Ozgu, Emre; Terzioglu, Gokay Serdar; Buyukkagnici, Umran; Akbay, Serap; Caydere, Muzaffer; Gungor, Tayfun

2016-09-01

Platelet-rich plasma (PRP) has been known to possess an efficacy in tissue regeneration. The aim of this study was to determine the role of PRP on post-operative adhesion formation in an experimental rat study. Thirty Sprague-Dawley rats were randomly divided into control, hyaluronic acid, and PRP treatment groups and operated on for uterine horn adhesion modeling. Blood was collected to produce a PRP with platelet counts of 688 × 10(3)/μL, and 1 ml of either hyaluronic acid gel or PRP was administered over the standard lesions, while the control group received no medication. The evaluation of post-operative adhesions was done on the 30th post-operative day. The location, extent, type, and tenacity of adhesions as well as total adhesion scores, tissue inflammation, fibrosis and transforming growth factor-1beta (TGF-1β) expressions were evaluated. The total adhesion score was significantly lower in the PRP group (3.2 ± 1.5) compared with the hyaluronic acid (5.0 ± 1.3) and control (8.1 ± 1.7) groups. The extent of the adhesions was significantly lower in the PRP group. There was no significant difference in the type and tenacity of adhesions between the hyaluronic acid and the PRP group. The level of inflammation was significantly higher in the control group than the others, while there was no difference between the PRP and hyaluronic acid groups. TGF-1β expression was significantly lesser in the PRP group than the control and hyaluronic acid groups. PRP is more effective than hyaluronic acid treatment in preventing post-operative adhesion formation in an experimental rat uterine horn adhesion model.

Elevated levels of maternal anti-tetanus toxin antibodies do not suppress the immune response to a Haemophilus influenzae type b polyribosylphosphate-tetanus toxoid conjugate vaccine.

PubMed Central

Panpitpat, C.; Thisyakorn, U.; Chotpitayasunondh, T.; Fürer, E.; Que, J. U.; Hasler, T.; Cryz, S. J.

2000-01-01

Reported are the effects of elevated levels of anti-tetanus antibodies on the safety and immune response to a Haemophilus influenzae type b polyribosylphosphate (PRP)-tetanus toxoid conjugate (PRP-T) vaccine. A group of Thai infants (n = 177) born to women immunized against tetanus during pregnancy were vaccinated with either a combined diphtheria-tetanus-pertussis (DTP) PRP-T vaccine or DTP and a PRP-conjugate vaccine using Neisseria meningitidis group B outer-membrane proteins as a carrier (PedVax HIB). Although most infants possessed high titres (> 1 IU/ml) of anti-tetanus antibodies, the DTP-PRP-T combined vaccine engendered an excellent antibody response to all vaccine components. In both vaccine groups > 98% of infants attained anti-PRP antibody titres > or = 0.15 microgram/ml. The geometric mean anti-PRP antibody titres were 5.41 micrograms/ml and 2.1 micrograms/ml for infants immunized with three doses of PRP-T versus two doses of PedVax HIB vaccines, respectively (P < 0.005). Similarly, the proportion of infants who achieved titres > or = 1 microgram/ml was higher in the PRP-T group (87.8%) than in the group immunized with PedVax HIB (74.2%) (P = 0.036). A subgroup analysis showed that there was no significant difference in the anti-PRP antibody response for infants exhibiting either < 1 IU of anti-tetanus antibody per millilitre or > or = 1 IU/ml at baseline. These finding indicate that pre-existing anti-carrier antibody does not diminish the immune response to the PRP moiety. All infants possessed protective levels of anti-D and anti-T antibody levels after immunization. PMID:10812736

The Composite of Bone Marrow Concentrate and PRP as an Alternative to Autologous Bone Grafting

PubMed Central

Hakimi, Mohssen; Grassmann, Jan-Peter; Betsch, Marcel; Schneppendahl, Johannes; Gehrmann, Sebastian; Hakimi, Ahmad-Reza; Kröpil, Patric; Sager, Martin; Herten, Monika; Wild, Michael; Windolf, Joachim; Jungbluth, Pascal

2014-01-01

One possible alternative to the application of autologous bone grafts represents the use of autologous bone marrow concentrate (BMC). The purpose of our study was to evaluate the potency of autologous platelet-rich plasma (PRP) in combination with BMC. In 32 mini-pigs a metaphyseal critical-size defect was surgically created at the proximal tibia. The animals were allocated to four treatment groups of eight animals each (1. BMC+CPG group, 2. BMC+CPG+PRP group, 3. autograft group, 4. CPG group). In the BMC+CPG group the defect was filled with autologous BMC in combination with calcium phosphate granules (CPG), whereas in the BMC+CPG+PRP group the defect was filled with the composite of autologous BMC, CPG and autologous PRP. In the autograft group the defect was filled with autologous cancellous graft, whereas in the CPG group the defect was filled with CPG solely. After 6 weeks radiological and histomorphometrical analysis showed significantly more new bone formation in the BMC+CPG+PRP group compared to the BMC+CPG group and the CPG group. There were no significant differences between the BMC+CPG+PRP group and the autograft group. In the PRP platelets were enriched significantly about 4.7-fold compared to native blood. In BMC the count of mononuclear cells increased significantly (3.5-fold) compared to the bone marrow aspirate. This study demonstrates that the composite of BMC+CPG+PRP leads to a significantly higher bone regeneration of critical-size defects at the proximal tibia in mini-pigs than the use of BMC+CPG without PRP. Furthermore, within the limits of the present study the composite BMC+CPG+PRP represents a comparable alternative to autologous bone grafting. PMID:24950251

Intraarticular injection autologous platelet-rich plasma and bone marrow concentrate in a goat osteoarthritis model.

PubMed

Wang, Zhen; Zhai, Chenjun; Fei, Hao; Hu, Junzheng; Cui, Weiding; Wang, Zhen; Li, Zeng; Fan, Weimin

2018-02-21

To evaluate the effects of intraarticular injections of autologous platelet-rich plasma (PRP) or bone marrow concentrate (BMC) on osteoarthritis (OA), 24 adult goats were equally divided into control (Ctrl), saline (NS), PRP, and BMC groups, and OA was induced by surgery in NS, PRP, and BMC groups. Autologous PRP and BMC were obtained from whole blood and bone marrow aspirates, respectively. The data revealed, platelets were increased in BMC by 1.8-fold, monocytes by 5.6-fold, TGF-β1 by 7.7-fold, and IGF-1 by 3.6-fold (p < 0.05), and platelets were increased in PRP by 2.9-fold, and TGF-β1 by 3.3-fold (p < 0.05). From the sixth week post-operation, saline, PRP, and BMC were administered by intraarticular injection once every 4 weeks, three consecutive times. After the animals were sacrificed, inflammatory cytokines in the synovial fluid was measured, and bone and cartilage degeneration progression was observed by macroscopy, histology, and immunohistochemistry. Compared with the NS group, the level of inflammatory cytokines was reduced in the PRP and BMC groups (p < 0.05). Histologically, delayed cartilage degeneration and higher levels of extracellular matrix (ECM) were observed in both PRP and BMC treated groups (p < 0.05). Furthermore, the BMC group showed greater cartilage protection and less ECM loss than the PRP group (p < 0.05). In summary, this study showed that intraarticular injection of autologous PRP and BMC has therapeutic efficacy in a goat osteoarthritis model, with the greater benefit in terms of cartilage protection being observed in the BMC-treated group than PRP. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

An in vitro evaluation of the anti-inflammatory effects of platelet-rich plasma, ketorolac, and methylprednisolone.

PubMed

Mazzocca, Augustus D; McCarthy, Mary Beth R; Intravia, Jessica; Beitzel, Knut; Apostolakos, John; Cote, Mark P; Bradley, James; Arciero, Robert A

2013-04-01

The purpose of this study was to quantify the extent of the anti-inflammatory effect of platelet-rich plasma (PRP) in a controlled in vitro environment. Through the stimulation of human umbilical vein endothelial cells with inflammatory cytokines (tumor necrosis factor α and interferon γ), cell adhesion molecule expression (E-selectin, vascular cell adhesion molecule, and human leukocyte antigen DR) and PRP's anti-inflammatory effect can be measured. PRP was produced from 3 individuals using a single-spin (PRPLP) process. Treatment groups include negative (unstimulated) controls, positive (stimulated) controls, ketorolac tromethamine, methylprednisolone, PRP, ketorolac-PRP, and methylprednisolone-PRP. A fluorescence assay of the cellular inflammation markers was measured by the BioTek Synergy HT plate reader (BioTek Instruments, Winooski, VT) at 0, 1, 2, and 5 days. At days 2 and 5, methylprednisolone treatment showed a 2.1- to 5.8-fold reduction (P < .05) in inflammation markers over PRP. In addition, PRP and ketorolac showed a 1.4- to 2.5-fold reduction (P < .05) in cellular inflammation markers over the control. There was no statistically significant difference between ketorolac and PRP. Although PRP and ketorolac reduced cellular inflammation markers (E-selectin, vascular cell adhesion molecule, and human leukocyte antigen DR) compared with control, neither caused as great a reduction as methylprednisolone. Although PRP and ketorolac did not produce as significant a reduction in cellular inflammation markers as methylprednisolone, they reduced cellular inflammation compared with the control. These agents may have clinical application as injectable anti-inflammatory medications. Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Effects of intravitreal injection of ranibizumab on choroidal structure and blood flow in eyes with diabetic macular edema.

PubMed

Okamoto, Masahiro; Yamashita, Mariko; Ogata, Nahoko

2018-05-01

To determine the effects of an intravitreal injection of ranibizumab (IVR) on the choroidal structure and blood flow in eyes with diabetic macular edema (DME). Twenty-eight consecutive patients with DME who received an IVR and 20 non-diabetic, age-matched controls were followed for 1 month. The eyes with DME were divided into those with prior panretinal photocoagulation (PRP, n = 16) and those without prior PRP (no-PRP, n = 12). The enhanced depth imaging optical coherence tomography (EDI-OCT) scans and Niblack's image binarization were performed to determine the choroidal structure. The choroidal blood flow was determined by laser speckle flowgraphy. The subfoveal choroidal thickness at the baseline was significantly thicker in the no-PRP group than in the PRP-treated group. After IVR, the best-corrected visual acuity (BCVA) and central retinal thickness in eyes with DME were significantly improved compared to the baseline values. There were significant differences in the choroidal thickness, total choroidal area, and choroidal vascularity index between the groups after IVR. Choroidal vascular index and choroidal blood flow were significantly reduced only in the no-PRP group and not in the PRP-treated group. In addition, the correlation between the central retinal thickness and the choroidal blood flow was significant in the no-PRP group (r = 0.47, P < 0.05). A single IVR will reduce the central retinal thickness and improve the BCVA in eyes with DME in both the no-PRP and PRP-treated group. IVR affected the choroidal vasculature and blood flow significantly, and a significant correlation was found between the central retinal thickness and the choroidal blood flow in eyes without PRP.

Platelet-rich plasma use in anterior cruciate ligament surgery: systematic review of the literature.

PubMed

Figueroa, David; Figueroa, Francisco; Calvo, Rafael; Vaisman, Alex; Ahumada, Ximena; Arellano, Sergio

2015-05-01

To systematically review the current literature for evidence that would substantiate the use of platelet-rich plasma (PRP) in the treatment of anterior cruciate ligament (ACL) ruptures. We performed a systematic search in PubMed and Embase of studies written in the English and Spanish languages that compared the use of PRP with a control group in patients with ACL injuries assessing graft-to-bone healing, graft maturation, and/or clinical outcomes and were randomized controlled trials or prospective cohort studies. Eleven studies fulfilled the inclusion criteria, comprising 516 patients (266 ACL reconstructions using PRP and 250 ACL reconstructions without PRP). Six studies reported a statistically significant difference (4 studies) or tendency toward faster graft maturation in the platelet group (2 studies). One study found no differences. Regarding tunnel healing/widening, 1 study showed faster healing in the PRP group and 5 studies showed no differences between the 2 groups. Considering clinical outcomes, 1 study showed better clinical outcomes with PRP use and 5 studies showed no benefits with the use of PRP. Concerning ACL graft maturation, there is promising evidence that the addition of PRP could be a synergic factor in acquiring maturity more quickly than grafts with no PRP, with the clinical implication of this remaining unclear. Regarding tunnel healing, it appears that there is not an improvement with the addition of PRP. There is no proof that clinical outcomes of ACL surgery are enhanced by the use of PRP. Level III, systematic review of Level I through III studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Platelet-rich plasma and platelet gel preparation using Plateltex.

PubMed

Mazzucco, L; Balbo, V; Cattana, E; Borzini, P

2008-04-01

The platelet gel is made by embedding concentrate platelets within a semisolid (gel) network of polymerized fibrin. It is believed that this blood component will be used more and more in the treatment of several clinical conditions and as an adjunctive material in tissue engineering. Several systems are available to produce platelet-rich plasma (PRP) for topical therapy. Recently, a new system became commercially available, Plateltex. Here we report the technical performance of this system in comparison with the performance of other commercially available systems: PRGF, PRP-Landesber, Curasan, PCCS, Harvest, Vivostat, Regen and Fibrinet. Both the PRP and the gel were prepared according to the manufacturer's directions. The blood samples of 20 donors were used. The yield, the efficiency, and the amount of platelet-derived growth factor AB (PDGF-AB), transforming growth factor beta, vascular endothelial growth factor and fibroblast growth factor were measured in the resulting PRP. The feature of the batroxobin-induced gelation was evaluated. The yield, the collection efficiency and the growth factor content of Plateltex were comparable to those of most of the other available systems. The gelation time was not dependent on the fibrinogen concentration; however, it was strongly influenced by the contact surface area of the container where the clotting reaction took place (P < 0.0001). Plateltex provided platelet recovery, collection efficiency and PDGF-AB availability close to those provided by other systems marketed with the same intended use. Batroxobin, the enzyme provided to induce gelation, acts differently from thrombin, which is used by most other systems. Platelets treated with thrombin become activated; they release their growth factors quickly. Furthermore, thrombin-platelet interaction is a physiological mechanism that hastens the clot-retraction rate. On the contrary, platelets treated with batroxobin do not become activated; they are passively entrapped within the fibrin network, and their growth factor release occurs slowly. In these conditions, the clot retraction takes longer to occur. According to these differences between thrombin and batroxobin, it is expected that batroxobin-induced PRP activation will tailor slow release of the platelet content, thus, providing longer in loco availability of trophic factors. In selected clinical conditions, this durable anabolic factor availability might be preferable to quick thrombin-induced growth factor release.

Pilot randomised clinical trial of Pascal TargETEd Retinal versus variable fluence PANretinal 20 ms laser in diabetic retinopathy: PETER PAN study.

PubMed

Muqit, Mahiul M K; Young, Lorna B; McKenzie, Rod; John, Binu; Marcellino, George R; Henson, David B; Turner, George S; Stanga, Paulo E

2013-02-01

To investigate the short-term effects of high-density 20-ms laser on macular thickness using Pascal-targeted retinal photocoagulation (TRP) and reduced fluence/minimally-traumatic panretinal photocoagulation (MT-PRP) compared to standard-intensity PRP (SI-PRP) in proliferative diabetic retinopathy (PDR). Prospective randomised clinical trial. Treatment-naive PDR was treated with single-session 20-ms Pascal 2500 burns photocoagulation randomised to one of three treatment arms (TRP:MT-PRP:SI-PRP). Primary outcome measure was change in central retinal thickness (CRT) on OCT. Secondary outcomes at 4 and 12 weeks post-laser included: OCT peripapillary nerve fibre layer (NFL) thickness; PDR disease regression on Optos angiography; SITA-Std visual fields (VF); and, visual acuity (VA). 30 eyes of 24 patients were studied, ten eyes/arm. At 12 weeks, there were significant reductions in CRT after TRP (9.6 µm; 95% CI, 1.84 to 17.36; p=0.021) and MT-PRP (17.1 µm; 95% CI, 11 to 23.2; p=0.001), versus SI-PRP (+5.9 µm; 95% CI, -6.75 to 18.55; p=0.32). PDR regression was similar between groups (TRP 70%; MT-PRP 70%; SI-PRP 90%; κ=0.76). No significant changes in VA and NFL thickness developed between groups. The VF mean deviation scores increased significantly in all groups at 12 weeks ([TRP, +0.70dB; 95% CI, 0.07 to 1.48; p=0.07], [MT-PRP, +0.63dB; 95% CI, 0.12 to 1.15; p=0.02], [SI-PRP, +1.0dB; 95% CI, 0.19 to 1.74; p=0.02]). There were no laser-related ocular complications. This pilot study reports that high-density 20-ms Pascal TRP and MT-PRP using 2500 burns did not produce increased macular thickness or any ocular adverse events during the short-term.

Stimulation of the Superficial Zone Protein and Lubrication in the Articular Cartilage by Human Platelet-Rich Plasma

PubMed Central

Sakata, Ryosuke; McNary, Sean M.; Miyatake, Kazumasa; Lee, Cassandra A.; Van den Bogaerde, James M.; Marder, Richard A.; Reddi, A. Hari

2016-01-01

Background Platelet-rich plasma (PRP) contains high concentrations of autologous growth factors that originate from platelets. Intra-articular injections of PRP have the potential to ameliorate the symptoms of osteoarthritis in the knee. Superficial zone protein (SZP) is a boundary lubricant in articular cartilage and plays an important role in reducing friction and wear and therefore is critical in cartilage homeostasis. Purpose To determine if PRP influences the production of SZP from human joint-derived cells and to evaluate the lubricating properties of PRP on normal bovine articular cartilage. Study Design Controlled laboratory study. Methods Cells were isolated from articular cartilage, synovium, and the anterior cruciate ligament (ACL) from 12 patients undergoing ACL reconstruction. The concentrations of SZP in PRP and culture media were measured by enzyme-linked immunosorbent assay. Cellular proliferation was quantified by determination of cell numbers. The lubrication properties of PRP from healthy volunteers on bovine articular cartilage were investigated using a pin-on-disk tribometer. Results In general, PRP stimulated proliferation in cells derived from articular cartilage, synovium, and ACL. It also significantly enhanced SZP secretion from synovium- and cartilage-derived cells. An unexpected finding was the presence of SZP in PRP (2.89 ± 1.23 µg/mL before activation and 3.02 ± 1.32 µg/mL after activation). In addition, under boundary mode conditions consisting of high loads and low sliding speeds, nonactivated and thrombin-activated PRP decreased the friction coefficient (μ = 0.012 and μ = 0.015, respectively) compared with saline (μ = 0.047, P < 0.004) and high molecular weight hyaluronan (μ = 0.080, P < 0.006). The friction coefficient of the cartilage with PRP was on par with that of synovial fluid. Conclusion PRP significantly stimulates cell proliferation and SZP secretion by articular cartilage and synovium of the human knee joint. Furthermore, PRP contains endogenous SZP and, in a functional bioassay, lubricates bovine articular cartilage explants. Clinical Relevance These findings provide evidence to explain the biochemical and biomechanical mechanisms underlying the efficacy of PRP treatment for osteoarthritis or damage in the knee joint. PMID:25813869

Familial CJD Associated PrP Mutants within Transmembrane Region Induced Ctm-PrP Retention in ER and Triggered Apoptosis by ER Stress in SH-SY5Y Cells

PubMed Central

Wang, Xin; Shi, Qi; Xu, Kun; Gao, Chen; Chen, Cao; Li, Xiao-Li; Wang, Gui-Rong; Tian, Chan; Han, Jun; Dong, Xiao-Ping

2011-01-01

Background Genetic prion diseases are linked to point and inserted mutations in the prion protein (PrP) gene that are presumed to favor conversion of the cellular isoform of PrP (PrPC) to the pathogenic one (PrPSc). The pathogenic mechanisms and the subcellular sites of the conversion are not completely understood. Here we introduce several PRNP gene mutations (such as, PrP-KDEL, PrP-3AV, PrP-A117V, PrP-G114V, PrP-P102L and PrP-E200K) into the cultured cells in order to explore the pathogenic mechanism of familial prion disease. Methodology/Principal Findings To address the roles of aberrant retention of PrP in endoplasmic reticulum (ER), the recombinant plasmids expressing full-length human PrP tailed with an ER signal peptide at the COOH-terminal (PrP-KDEL) and PrP with three amino acids exchange in transmembrane region (PrP-3AV) were constructed. In the preparations of transient transfections, 18-kD COOH-terminal proteolytic resistant fragments (Ctm-PrP) were detected in the cells expressing PrP-KDEL and PrP-3AV. Analyses of the cell viabilities in the presences of tunicamycin and brefeldin A revealed that expressions of PrP-KDEL and PrP-3AV sensitized the transfected cells to ER stress stimuli. Western blots and RT-PCR identified the clear alternations of ER stress associated events in the cells expressing PrP-KDEL and PrP-3AV that induced ER mediated apoptosis by CHOP and capase-12 apoptosis pathway. Moreover, several familial CJD related PrP mutants were transiently introduced into the cultured cells. Only the mutants within the transmembrane region (G114V and A117V) induced the formation of Ctm-PrP and caused the ER stress, while the mutants outside the transmembrane region (P102L and E200K) failed. Conclusions/Significance The data indicate that the retention of PrP in ER through formation of Ctm-PrP results in ER stress and cell apoptosis. The cytopathic activities caused by different familial CJD associated PrP mutants may vary, among them the mutants within the transmembrane region undergo an ER-stress mediated cell apoptosis. PMID:21298055

Effect of arthrocentesis plus platelet-rich plasma and platelet-rich plasma alone in the treatment of temporomandibular joint osteoarthritis: A retrospective matched cohort study (A STROBE-compliant article).

PubMed

Lin, Shang-Lun; Tsai, Chiang-Chin; Wu, Shang-Liang; Ko, Shun-Yao; Chiang, Wei-Fan; Yang, Jung Wu

2018-04-01

Although the research on using platelet-rich plasma (PRP) for temporomandibular joint osteoarthritis (TMJ-OA) has advanced, no unified standards exist for determining the joint use of arthrocentesis and the injection dose and frequency of PRP. This study aimed to compare the efficacy of 2 TMJ-OA treatment approaches, arthrocentesis plus platelet-rich plasma (A+PRP) and PRP alone, and attempted to provide another potential treatment option with a single injection of 2 mL of high-concentration and high-purity PRP.This retrospective matched cohort study enrolled 208 patients who were treated for temporomandibular disorders (TMDs) in the Department of Oral and Maxillofacial Surgery of Tainan Sin-Lau Hospital between August of 2013 and January of 2016, from which 90 patients were selected for the final analysis. The predictor variables were treatment outcome indicators, including joint crepitus sounds, TMD-associated headache, jaw range of motion <6 mm, myofascial pain with referral, temporomandibular joint (TMJ) arthralgia, pain when chewing most foods, and maximum assisted opening (MAO). The data were analyzed using χ tests, t tests, and multiple regression analyses.Among the 90 patients, 30 were assigned into the A+PRP group, and 60 were included in the PRP group. A matching method was used to ensure no statistically significant differences in the categorical and continuous variables between the 2 groups. After treatment, both the A+PRP and PRP groups showed improvements in TMJ-OA. The 2 treatment groups did not show statistically significant differences in the symptom improvement rates of joint crepitus sounds, reparative remodeling, and TMJ arthralgia. However, compared with PRP alone, the A+PRP treatment demonstrated superior performance in improving TMD-associated headache, jaw range of motion <6 mm, myofascial pain with referral, and pain when chewing most foods.Both A+PRP and PRP treatments can effectively improve multiple symptoms of TMJ-OA. Based on the results from this study, we recommend a single injection with 2 mL of high-concentration and high-purity PRP for TMJ-OA treatment. For patients with TMJ-OA accompanied by other clinical symptoms, including TMD-associated headache, jaw range of motion <6 mm, myofascial pain with referral, and pain when chewing most foods, a treatment approach using arthrocentesis prior to a PRP injection can achieve a higher efficacy.

Isolation of an essential Schizosaccharomyces pombe gene, prp31+, that links splicing and meiosis

PubMed Central

Bishop, Danielle T.; McDonald, W. Hayes; Gould, Kathleen L.; Forsburg, Susan L.

2000-01-01

We carried out a screen for mutants that arrest prior to premeiotic S phase. One of the strains we isolated contains a temperature-sensitive allele mutation in the fission yeast prp31+ gene. The prp31-E1 mutant is defective in vegetative cell growth and in meiotic progression. It is synthetically lethal with prp6 and displays a pre-mRNA splicing defect at the restrictive temperature. We cloned the wild-type gene by complementation of the temperature-sensitive mutant phenotype. Prp31p is closely related to human and budding yeast PRP31 homologs and is likely to function as a general splicing factor in both vegetative growth and sexual differentiation. PMID:10871341

Does platelet-rich plasma deserve a role in the treatment of tendinopathy?

PubMed

Nourissat, Geoffroy; Ornetti, Paul; Berenbaum, Francis; Sellam, Jérémie; Richette, Pascal; Chevalier, Xavier

2015-07-01

Although tendinopathies constitute a heterogeneous group of conditions, they are often treated by similar combinations of local and systemic symptomatic interventions. The vast number of causes, pathophysiological mechanisms, and histological changes that characterizes tendinopathies may explain that the standard treatment fails in some patients. Platelet-rich plasma (PRP), which contains a host of soluble mediators including growth factors, has been suggested as a second-line treatment for refractory tendinopathy, with the goal of expediting tendon healing or remodeling. Here, we report a systematic literature review of basic research data from humans and animals that support the clinical use of PRP in tendinopathies and of clinical studies in the most common tendinopathies (elbow, knee, shoulder, and Achilles tendon). Our objective is to clarify the role for this new injectable treatment, which is garnering increasing attention. The level of evidence remains low, as few well-designed randomized controlled trials have been published. The available scientific evidence does not warrant the use of PRP for the first-line treatment of tendinopathy. PRP therapy may deserve consideration in specific tendinopathy subtypes, after failure of ultrasound-guided corticosteroid injections. Nevertheless, further studies are needed to define these potential indications and the optimal treatment protocols. A key point is that the complexity of the tendon healing process cannot be replicated simply by injecting a subset of growth factors, whose effects may occur in opposite directions over time. Topics not discussed in this review are the regulatory framework for PRP therapy, PRP nomenclature, and precautions for use, which are described in a previous article (Does platelet-rich plasma have a role in the treatment of osteoarthritis, Ornetti P, et al. [1]). Copyright © 2015 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

Activation of platelet-rich plasma using soluble type I collagen.

PubMed

Fufa, Duretti; Shealy, Blake; Jacobson, May; Kevy, Sherwin; Murray, Martha M

2008-04-01

Platelet-rich plasma (PRP) has recently been found to be a useful delivery system for growth factors important to oral tissue healing. But application of PRP in a liquid form to a wound site within the oral cavity can be complicated by significant loss of the PRP into the surrounding oral space unless gelation through the clotting mechanism is accomplished. Gelation is currently accomplished using bovine thrombin; however, rare but serious complications of this method have led to the search for alternative clotting mechanisms, including the use of soluble collagen as a clotting activator. In this work, our hypothesis was that soluble type I collagen would be as effective as bovine thrombin in causing clotting of the PRP and stimulating growth factor release from the platelets and granulocytes. PRP from human donors was clotted using type I collagen or bovine thrombin. Clot retraction was determined by measuring clot diameters over time. The release of platelet-derived growth factor (PDGF)-AB, transforming growth factor (TGF)-beta1, and vascular endothelial growth factor (VEGF) from both types of clots was measured over 10 days using enzyme-linked immunosorbent assasy. Clots formed using type I collagen exhibited far less retraction than those formed with bovine thrombin. Bovine thrombin and type I collagen stimulated similar release of PDGF-AB and VEGF between 1 and 10 days; however, thrombin activation resulted in a greater release of TGF-beta1 during the first 5 days after activation. The use of type I collagen to activate clotting of PRP may be a safe and effective alternative to bovine thrombin. The use of collagen results in less clot retraction and equal release of PDGF-AB and VEGF compared with currently available methods of clot activation.

ACTIVATION OF PLATELET-RICH PLASMA USING SOLUBLE TYPE I COLLAGEN

PubMed Central

Fufa, Duretti; Shealy, Blake; Jacobson, May; Kevy, Sherwin; Murray, Martha M.

2008-01-01

PURPOSE Platelet-rich plasma (PRP) has recently been found to be a useful delivery system for growth factors important in oral tissue healing. However, application of PRP in a liquid form to a wound site within the oral cavity can be complicated by significant loss of the PRP into the surrounding oral space unless gelation via the clotting mechanism is accomplished. Gelation is currently accomplished using bovine thrombin; however, rare but serious complications of this method have led to the search for alternative clotting mechanisms, including the use of soluble collagen as a clotting activator. In this paper, our hypothesis was that soluble Type I collagen would be as effective as bovine thrombin in causing clotting of the PRP and of stimulating growth factor release from the platelets and granulocytes. MATERIALS AND METHODS PRP from human donors was clotted using Type I collagen or bovine thrombin. Clot retraction was determined by measuring clot diameters over time. The release of PDGF-AB, TGF-β1 and VEGF from both types of clots was measured over 10 days using ELISA. RESULTS Clots formed using Type I collagen had far less retraction than those formed with bovine thrombin. Bovine thrombin and Type I collagen stimulated similar release of PDGF-AB and VEGF between 1 and 10 days; however, thrombin activation resulted in a greater release of TGF-β1 during the first five days after activation. CONCLUSIONS The use of Type I collagen to activate clotting of PRP may be a safe and effective alternative to bovine thrombin. The use of collagen results in less clot retraction and equal release of PDGF-AB and VEGF when compared to currently available methods of clot activation. PMID:18355591

Platelet-rich plasma stimulated by pulse electric fields: Platelet activation, procoagulant markers, growth factor release and cell proliferation.

PubMed

Frelinger, A L; Torres, A S; Caiafa, A; Morton, C A; Berny-Lang, M A; Gerrits, A J; Carmichael, S L; Neculaes, V B; Michelson, A D

2016-01-01

Therapeutic use of activated platelet-rich plasma (PRP) has been explored for wound healing, hemostasis and antimicrobial wound applications. Pulse electric field (PEF) stimulation may provide more consistent platelet activation and avoid complications associated with the addition of bovine thrombin, the current state of the art ex vivo activator of therapeutic PRP. The aim of this study was to compare the ability of PEF, bovine thrombin and thrombin receptor activating peptide (TRAP) to activate human PRP, release growth factors and induce cell proliferation in vitro. Human PRP was prepared in the Harvest SmartPreP2 System and treated with vehicle, PEF, bovine thrombin, TRAP or Triton X-100. Platelet activation and procoagulant markers and microparticle generation were measured by flow cytometry. Released growth factors were measured by ELISA. The releasates were tested for their ability to stimulate proliferation of human epithelial cells in culture. PEF produced more platelet-derived microparticles, P-selectin-positive particles and procoagulant annexin V-positive particles than bovine thrombin or TRAP. These differences were associated with higher levels of released epidermal growth factor after PEF than after bovine thrombin or TRAP but similar levels of platelet-derived, vascular-endothelial, and basic fibroblast growth factors, and platelet factor 4. Supernatant from PEF-treated platelets significantly increased cell proliferation compared to plasma. In conclusion, PEF treatment of fresh PRP results in generation of microparticles, exposure of prothrombotic platelet surfaces, differential release of growth factors compared to bovine thrombin and TRAP and significant cell proliferation. These results, together with PEF's inherent advantages, suggest that PEF may be a superior alternative to bovine thrombin activation of PRP for therapeutic applications.

Molecular Dynamics Study on the Photothermal Actuation of a Glassy Photoresponsive Polymer Reinforced with Gold Nanoparticles with Size Effect.

PubMed

Choi, Joonmyung; Chung, Hayoung; Yun, Jung-Hoon; Cho, Maenghyo

2016-09-14

We investigated the optical and thermal actuation behavior of densely cross-linked photoresponsive polymer (PRP) and polymer nanocomposites containing gold nanoparticles (PRP/Au) using all-atom molecular dynamics (MD) simulations. The modeled molecular structures contain a large number of photoreactive mesogens with linear orientation. Flexible side chains are interconnected through covalent bonds under periodic boundary conditions. A switchable dihedral potential was applied on a diazene moiety to describe the photochemical trans-to-cis isomerization. To quantify the photoinduced molecular reorientation and its effect on the macroscopic actuation of the neat PRP and PRP/Au materials, we characterized the photostrain and other material properties including elastic stiffness and thermal stability according to the photoisomerization ratio of the reactive groups. We particularly examined the effect of nanoparticle size on the photothermal actuation by varying the diameter of the nanofiller (10-20 Å) under the same volume fraction of 1.62%. The results indicated that the insertion of the gold nanoparticles enlarges the photostrain of the material while enhancing its mechanical stiffness and thermal stability. When the diameter of the nanoparticle reaches a size similar to or smaller than the length of the mesogen, the interfacial energy between the nanofiller and the surrounding polymer matrix does not significantly affect the alignment of the mesogens, but rather the adsorption energy at the interface generates a stable interphase layer. Hence, these improvements were more effective as the size of the gold nanoparticle decreased. The present findings suggest a wider analysis of the nanofiller-reinforced PRP composites and could be a guide for the mechanical design of the PRP actuator system.

[Adjusting Platelet Counts for Platelet Aggregation Tests].

PubMed

Ling, Li-Qin; Yang, Xin-Chun; Chen, Hao; Liu, Chao-Nan; Chen, Si; Jiang, Hong; Jin, Ya-Xiong; Zhou, Jing

2018-03-01

To explore a better method to adjust platelet counts for light transmission aggregometry (LTA). Blood samples from 36 healthy participants aged from 18 to 50 yr. were collected.Platelet-rich plasma (PRP) was diluted using platelet-poor plasma (PPP) and physiological saline (PS),respectively,in a ratio of 1.5,2,2.5 and 3 times. Platelet aggregation was induced by adenosine diphosphate (ADP),arachidonic acid (ARA),collagen (COL), epinephrine (EPI),or ristocetin (RIS). The maximal aggregation rates (MAs) of different approaches were compared. We also compared the MAs induced by RIS between PRP-obtained-PPP and whole blood-obtained-PPP (2 100× g, 5 min). Compared with the original PRP,the MAs induced by ADP,ARA,and EPI decreased in PPP-adjusted PRP (significant at 2-3 times dilution ratio, P <0.05),but not in PS-adjusted PRP ( P >0.05). The MA induced by RIS decreased in PS-adjusted PRP (significant at all dilution ratios, P <0.05),but not in PPP-adjusted PRP ( P >0.05). No changes in the MA induced by COL were found in PS-adjusted PRP and PPP-adjusted PRP ( P >0.05). Whole blood-obtained-PPP (2 100× g, 5 min) had the same MA induced by ristocetin compared with PRP-obtained-PPP ( P >0.05). PS is recommended for adjusting platelets counts for platelet aggregation induced by ADP,ARA,COL and EPI. Whole blood-obtained-PPP (2 100 × g, 5 min) is recommended for RIS-induced aggregation as a matter of convenience. Copyright© by Editorial Board of Journal of Sichuan University (Medical Science Edition).

Curcumin Induces Apoptosis in Human Colorectal Carcinoma (HCT-15) Cells by Regulating Expression of Prp4 and p53

PubMed Central

Shehzad, Adeeb; Lee, Jaetae; Huh, Tae-Lin; Lee, Young Sup

2013-01-01

Curcumin (diferuloylmethane), the yellow pigment of turmeric, is one of the most commonly used and extensively studied phytochemicals due to its pleiotropic effects in several human cancers. In the current study, the therapeutic efficacy of curcumin was investigated in human colorectal carcinoma HCT-15 cells. Curcumin inhibited HCT-15 cells proliferation and induced apoptosis in a dose- and time-dependent manner. Hoechst 33342 and DCFHDA staining revealed morphological and biochemical features of apoptosis as well as ROS generation in HCT-15 cells treated with 30 and 50 μM curcumin. Over-expression of pre-mRNA processing factor 4B (Prp4B) and p53 mutations have been reported as hallmarks of cancer cells. Western blot analysis revealed that curcumin treatment activated caspase-3 and decreased expression of p53 and Prp4B in a time-dependent manner. Transfection of HCT-15 cells with Prp4B clone perturbed the growth inhibition induced by 30 μM curcumin. Fractionation of cells revealed increased accumulation of Prp4B in the nucleus, following its translocation from the cytoplasm. To further evaluate the underlying mechanism and survival effect of Prp4B, we generated siRNA-Prp4B HCT15 clones. Knockdown of Prp4B with siRNA diminished the protective effects of Prp4B against curcumin-induced apoptosis. These results suggest a possible underlying molecular mechanism in which Prp4B over-expression and activity are closely associated with the survival and regulation of apoptotic events in human colon cancer HCT-15 cells. PMID:23686430

Basic characteristics of plasma rich in growth factors (PRGF): blood cell components and biological effects.

PubMed

Nishiyama, Kazuhiko; Okudera, Toshimitsu; Watanabe, Taisuke; Isobe, Kazushige; Suzuki, Masashi; Masuki, Hideo; Okudera, Hajime; Uematsu, Kohya; Nakata, Koh; Kawase, Tomoyuki

2016-11-01

Platelet-rich plasma (PRP) is widely used in regenerative medicine because of its high concentrations of various growth factors and platelets. However, the distribution of blood cell components has not been investigated in either PRP or other PRP derivatives. In this study, we focused on plasma rich in growth factors (PRGF), a PRP derivative, and analyzed the distributions of platelets and white blood cells (WBCs). Peripheral blood samples were collected from healthy volunteers ( N  = 14) and centrifuged to prepare PRGF and PRP. Blood cells were counted using an automated hematology analyzer. The effects of PRP and PRGF preparations on cell proliferation were determined using human periosteal cells. In the PRGF preparations, both red blood cells and WBCs were almost completely eliminated, and platelets were concentrated by 2.84-fold, whereas in the PRP preparations, both platelets and WBCs were similarly concentrated by 8.79- and 5.51-fold, respectively. Platelet counts in the PRGF preparations were positively correlated with platelet counts in the whole blood samples, while the platelet concentration rate was negatively correlated with red blood cell counts in the whole blood samples. In contrast, platelet counts and concentration rates in the PRP preparations were significantly influenced by WBC counts in whole blood samples. The PRP preparations, but not the PRGF preparations, significantly suppressed cell growth at higher doses in vitro. Therefore, these results suggest that PRGF preparations can clearly be distinguished from PRP preparations by both inclusion of WBCs and dose-dependent stimulation of periosteal cell proliferation in vitro.

Basic characteristics of plasma rich in growth factors (PRGF): blood cell components and biological effects

PubMed Central

Nishiyama, Kazuhiko; Okudera, Toshimitsu; Watanabe, Taisuke; Isobe, Kazushige; Suzuki, Masashi; Masuki, Hideo; Okudera, Hajime; Uematsu, Kohya; Nakata, Koh

2016-01-01

Abstract Platelet‐rich plasma (PRP) is widely used in regenerative medicine because of its high concentrations of various growth factors and platelets. However, the distribution of blood cell components has not been investigated in either PRP or other PRP derivatives. In this study, we focused on plasma rich in growth factors (PRGF), a PRP derivative, and analyzed the distributions of platelets and white blood cells (WBCs). Peripheral blood samples were collected from healthy volunteers (N = 14) and centrifuged to prepare PRGF and PRP. Blood cells were counted using an automated hematology analyzer. The effects of PRP and PRGF preparations on cell proliferation were determined using human periosteal cells. In the PRGF preparations, both red blood cells and WBCs were almost completely eliminated, and platelets were concentrated by 2.84‐fold, whereas in the PRP preparations, both platelets and WBCs were similarly concentrated by 8.79‐ and 5.51‐fold, respectively. Platelet counts in the PRGF preparations were positively correlated with platelet counts in the whole blood samples, while the platelet concentration rate was negatively correlated with red blood cell counts in the whole blood samples. In contrast, platelet counts and concentration rates in the PRP preparations were significantly influenced by WBC counts in whole blood samples. The PRP preparations, but not the PRGF preparations, significantly suppressed cell growth at higher doses in vitro. Therefore, these results suggest that PRGF preparations can clearly be distinguished from PRP preparations by both inclusion of WBCs and dose‐dependent stimulation of periosteal cell proliferation in vitro. PMID:29744155

The Splicing ATPase Prp43p Is a Component of Multiple Preribosomal Particles

PubMed Central

Lebaron, Simon; Froment, Carine; Fromont-Racine, Micheline; Rain, Jean-Christophe; Monsarrat, Bernard; Caizergues-Ferrer, Michèle; Henry, Yves

2005-01-01

Prp43p is a putative helicase of the DEAH family which is required for the release of the lariat intron from the spliceosome. Prp43p could also play a role in ribosome synthesis, since it accumulates in the nucleolus. Consistent with this hypothesis, we find that depletion of Prp43p leads to accumulation of 35S pre-rRNA and strongly reduces levels of all downstream pre-rRNA processing intermediates. As a result, the steady-state levels of mature rRNAs are greatly diminished following Prp43p depletion. We present data arguing that such effects are unlikely to be solely due to splicing defects. Moreover, we demonstrate by a combination of a comprehensive two-hybrid screen, tandem-affinity purification followed by mass spectrometry, and Northern analyses that Prp43p is associated with 90S, pre-60S, and pre-40S ribosomal particles. Prp43p seems preferentially associated with Pfa1p, a novel specific component of pre-40S ribosomal particles. In addition, Prp43p interacts with components of the RNA polymerase I (Pol I) transcription machinery and with mature 18S and 25S rRNAs. Hence, Prp43p might be delivered to nascent 90S ribosomal particles during pre-rRNA transcription and remain associated with preribosomal particles until their final maturation steps in the cytoplasm. Our data also suggest that the ATPase activity of Prp43p is required for early steps of pre-rRNA processing and normal accumulation of mature rRNAs. PMID:16227579

Platelet-rich plasma-containing fragmin-protamine micro-nanoparticles promote epithelialization and angiogenesis in split-thickness skin graft donor sites.

PubMed

Takabayashi, Yuki; Ishihara, Masayuki; Sumi, Yuki; Takikawa, Makoto; Nakamura, Shingo; Kiyosawa, Tomoharu

2015-01-01

Platelet-rich plasma (PRP) contains multiple growth factors, and fragmin-protamine micro-nanoparticles (F-P M-NPs) significantly enhance and stabilize growth factors. The purpose of this study was to evaluate the effects of PRP-containing F-P M-NPs (PRP&F-P M-NPs) on wound repair in split-thickness skin graft (STSG-) donor sites (DS). A total of 56 inbred male rats were anesthetized and split-thickness skin graft donor site (STSG-DS) were created with a Padgett dermatome. PRP&F-P M-NPs, F-P M-NPs, PRP, and saline (control) were then intradermally injected evenly into the STSG-DSs. On 3, 4, 5, 7, and 10 d after creation of STSG-DS, skin sample sections were stained with hematoxylin and eosin to evaluate reepithelialization and angiogenesis. Treatment of STSG-DS with PRP&F-P M-NPs effectively promoted epithelialization and new vessel formation compared with those treated with PRP, F-P M-NPs, and control (saline). The intradermal injection of PRP&F-P M-NPs promotes epithelialization and angiogenesis in STSG-DS wounds. Copyright © 2015 Elsevier Inc. All rights reserved.

Improving bone repair of femoral and radial defects in rabbit by incorporating PRP into PLGA/CPC composite scaffold with unidirectional pore structure.

PubMed

He, Fupo; Chen, Yan; Li, Jiyan; Lin, Bomiao; Ouyang, Yi; Yu, Bo; Xia, Yuanyou; Yu, Bo; Ye, Jiandong

2015-04-01

In this study, a platelet-rich plasma poly(lactic-co-glycolic acid) (PRP-PLGA)/calcium phosphate cement (CPC) composite scaffold was prepared by incorporating PRP into PLGA/CPC scaffold with unidirectional pore structure, which was fabricated by the unidirectional freeze casting of CPC slurry and the following infiltration of PLGA. The results from in vitro cell experiments and in vivo implantation in femoral defects manifested that incorporation of PRP into PLGA/CPC scaffold improved in vitro cell response (cell attachment, proliferation, and differentiation), and markedly boosted bone formation, angiogenesis and material degradation. The incorporation of PRP into scaffold showed more outstanding improvement in osteogenesis as the scaffolds were used to repair the segmental radial defects, especially at the early stage. The new bone tissues grew along the unidirectional lamellar pores of scaffold. At 12 weeks postimplantation, the segmental radial defects treated with PRP-PLGA/CPC scaffold had almost recuperated, whereas treated with the scaffold without PRP was far from healed. Taken together, the PRP-PLGA/CPC scaffold with unidirectional pore structure is a promising candidate to repair bone defects at various sites. © 2014 Wiley Periodicals, Inc.

Effect of autologous platelet-rich plasma application on cutaneous wound healing in dogs.

PubMed

Jee, Cho-Hee; Eom, Na-Young; Jang, Hyo-Mi; Jung, Hae-Won; Choi, Eul-Soo; Won, Jin-Hee; Hong, Il-Hwa; Kang, Byeong-Teck; Jeong, Dong Wook; Jung, Dong-In

2016-03-01

This study was conducted to identify the effectiveness of platelet-rich plasma (PRP) and efficacy of intralesional injection as a method of application to acute cutaneous wounds in dogs. Healthy adult beagles (n = 3) were used in this study. Autologous PRP was separated from anticoagulant treated whole blood in three dogs. Cutaneous wounds were created and then treated by intralesional injection of PRP in the experimental group, while they were treated with saline in the control group on days 0, 2 and 4. The healing process was evaluated by gross examination throughout the experimental period and histologic examination on day 7, 14 and 21. In PRP treated wounds, the mean diameter was smaller and the wound closure rate was higher than in the control. Histological study revealed that PRP treated wounds showed more granulation formation and angiogenesis on day 7, and faster epithelialization, more granulation formation and collagen deposition were observed on day 14 than in control wounds. On day 21, collagen deposition and epithelialization were enhanced in PRP treated groups. Overall, PRP application showed beneficial effects in wound healing, and intralesional injection was useful for application of PRP and could be a good therapeutic option for wound management in dogs.

Platelet-rich plasma for bone healing and regeneration.

PubMed

Oryan, Ahmad; Alidadi, Soodeh; Moshiri, Ali

2016-01-01

Successful healing of large bone defects (LBDs) is a complicated phenomenon because the body's natural ability often fails to effectively repair the LBDs. New modalities should be utilized to increase the quality and accelerate bone healing. Platelet concentrates in different forms can be considered an attractive option for such purpose. Platelets as a natural source of growth factors, cytokines, and other micro and macromolecules are hypothesized to improve bone healing. This review has covered important concepts regarding platelet-rich plasma (PRP) including mechanisms of action, preparation protocols and their differences, and factors affecting the PRP efficacy during bone healing. In addition, the most recent studies in different levels which evaluated the role of PRP on bone repair has been reviewed and discussed to clarify the controversies and conflicts, and to illustrate a future prospective and directions for orthopedic surgeons to overcome current limitations and difficulties. As the efficacy of PRP is dependent on various factors, the outcome of PRP therapy is variable and unpredictable in orthopedic patients. Therefore, it is still too soon to suggest PRP as the first line treatment option in complicated bone injuries such as LBDs and nonunions. However, combination of PRP with natural and synthetic biomaterials can enhance the effectiveness of PRP.

Effect of platelet-rich plasma on fibrocartilage, cartilage, and bone repair in temporomandibular joint.

PubMed

Kütük, Nükhet; Baş, Burcu; Soylu, Emrah; Gönen, Zeynep Burçin; Yilmaz, Canay; Balcioğlu, Esra; Özdamar, Saim; Alkan, Alper

2014-02-01

The purpose of the present study was to explore the potential use of platelet-rich-plasma (PRP) in the treatment of temporomandibular joint osteoarthritis (TMJ-OA). Surgical defects were created bilaterally on the condylar fibrocartilage, hyaline cartilage, and bone to induce an osteoarthritic TMJ in rabbits. PRP was applied to the right joints of the rabbits (PRP group), and the left joints received physiologic saline (control group). After 4 weeks, the rabbits were sacrificed for histologic and scanning electron microscopy (SEM) examinations. The data were analyzed statistically. The new bone regeneration was significantly greater in the PRP group (P < .011). Although the regeneration of the fibrocartilage and hyaline cartilage was greater in the PRP group, no statistically significant difference was found between the 2 groups. SEM showed better ultrastructural architecture of the collagen fibrils in the PRP group. PRP might enhance the regeneration of bone in TMJ-OA. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

USP15 regulates dynamic protein–protein interactions of the spliceosome through deubiquitination of PRP31

PubMed Central

Das, Tanuza; Park, Joon Kyu; Park, Jinyoung; Kim, Eunji; Rape, Michael

2017-01-01

Abstract Post-translational modifications contribute to the spliceosome dynamics by facilitating the physical rearrangements of the spliceosome. Here, we report USP15, a deubiquitinating enzyme, as a regulator of protein–protein interactions for the spliceosome dynamics. We show that PRP31, a component of U4 snRNP, is modified with K63-linked ubiquitin chains by the PRP19 complex and deubiquitinated by USP15 and its substrate targeting factor SART3. USP15SART3 makes a complex with USP4 and this ternary complex serves as a platform to deubiquitinate PRP31 and PRP3. The ubiquitination and deubiquitination status of PRP31 regulates its interaction with the U5 snRNP component PRP8, which is required for the efficient splicing of chromosome segregation related genes, probably by stabilizing the U4/U6.U5 tri-snRNP complex. Collectively, our data suggest that USP15 plays a key role in the regulation of dynamic protein–protein interactions of the spliceosome. PMID:28088760

The Prp19 WD40 Domain Contains a Conserved Protein Interaction Region Essential for its Function

PubMed Central

Vander Kooi, Craig W.; Ren, Liping; Xu, Ping; Ohi, Melanie D.; Gould, Kathleen L.; Chazin, Walter J.

2010-01-01

Summary Prp19 is a member of the WD40-repeat family of E3 ubiquitin ligases and a conserved eukaryotic RNA splicing factor essential for activation and stabilization of the spliceosome. To understand the role of the WD40 repeat domain of Prp19 we have determined its structure using X-ray crystallography. The domain has a distorted seven bladed WD40 architecture with significant asymmetry due to irregular packing of blades one and seven into the core of the WD40 domain. Structure-based mutagenesis identified a highly conserved surface centered around blade five that is required for the physical interaction between Prp19 and Cwc2, another essential splicing factor. This region is found to be required for Prp19 function and yeast viability. Experiments in vitro and in vivo demonstrate that two molecules of Cwc2 bind to the Prp19 tetramer. These coupled structural and functional studies provide a model for the functional architecture of Prp19. PMID:20462492

Production of a soluble recombinant prion protein fused to blue fluorescent protein without refolding or detergents in Escherichia coli cells.

PubMed

Arii, Yasuhiro; Yamaguchi, Hidenori; Fukuoka, Shin-Ichi

2007-10-01

The physiological function of prion proteins (PrP) remains unclear. To investigate the physiological relevance of PrP, we constructed a fusion protein of PrP with enhanced blue fluorescent protein (PrP-EBFP) to quantify the interaction of PrP with other molecules. Production of soluble PrP-EBFP was achieved by lowering the expression temperature in Escherichia coli (E. coli) cells to 15 degrees C. Soluble PrP-EBFP was purified on cation exchange and heparin-affinity columns to yield high purity protein. This is the first report of the preparation of soluble recombinant PrP without refolding following solubilization using denaturants or disruption using detergents. To confirm the integrity of PrP-EBFP, anisotropy was estimated under physiological conditions in the presence of heparin, which interacts with PrP. The dissociation constant was determined to be 0.88+/-0.07 microM. PrP-EBFP should be useful in the quantification of PrP interactions with other molecules.

[The study of anticoagulants selection in platelet-rich plasma preparation].

PubMed

Hua, Lei; Lai, Gui; Zhenjun, Liu; Guie, Ma

2015-07-01

To investigate the effect of the anticoagulants on PRP quality, so as to clarify the appropriate anticoagulant used in PRP production. The microstructure change of platelets collected via heparin, citrate, acid citrate dextrose (ACD) and citrate-theophylline-adenosine-dipyridamole ( CTAD) was observed by TEM following time course. The extent of spontaneous activation of platelets in four groups was detected by measuring sP-selectin in plasma. The TGF-β1 release amount of activated PRP of four groups was measured. CTAD is superior to other anticoagulants in maintaining the integrity of platelet structures for a long time and preventing platelet spontaneous activation. ACD slightly surpassed heparin and citrate in above two aspects. ACD-PRP and CTAD-PRP released significantly more TGF-β1 compared with heparin and citrate. The PRP quality and biological effects were strongly associated with the type of Anticoagulants. ACD and CTAD are optimal anticoagulants in PRP production for they can maintain platelet viability at a high level.

Increased infectivity of anchorless mouse scrapie prions in transgenic mice overexpressing human prion protein.

PubMed

Race, Brent; Phillips, Katie; Meade-White, Kimberly; Striebel, James; Chesebro, Bruce

2015-06-01

Prion protein (PrP) is found in all mammals, mostly as a glycoprotein anchored to the plasma membrane by a C-terminal glycosylphosphatidylinositol (GPI) linkage. Following prion infection, host protease-sensitive prion protein (PrPsen or PrPC) is converted into an abnormal, disease-associated, protease-resistant form (PrPres). Biochemical characteristics, such as the PrP amino acid sequence, and posttranslational modifications, such as glycosylation and GPI anchoring, can affect the transmissibility of prions as well as the biochemical properties of the PrPres generated. Previous in vivo studies on the effects of GPI anchoring on prion infectivity have not examined cross-species transmission. In this study, we tested the effect of lack of GPI anchoring on a species barrier model using mice expressing human PrP. In this model, anchorless 22L prions derived from tg44 mice were more infectious than 22L prions derived from C57BL/10 mice when tested in tg66 transgenic mice, which expressed wild-type anchored human PrP at 8- to 16-fold above normal. Thus, the lack of the GPI anchor on the PrPres from tg44 mice appeared to reduce the effect of the mouse-human PrP species barrier. In contrast, neither source of prions induced disease in tgRM transgenic mice, which expressed human PrP at 2- to 4-fold above normal. Prion protein (PrP) is found in all mammals, usually attached to cells by an anchor molecule called GPI. Following prion infection, PrP is converted into a disease-associated form (PrPres). While most prion diseases are species specific, this finding is not consistent, and species barriers differ in strength. The amino acid sequence of PrP varies among species, and this variability affects prion species barriers. However, other PrP modifications, including glycosylation and GPI anchoring, may also influence cross-species infectivity. We studied the effect of PrP GPI anchoring using a mouse-to-human species barrier model. Experiments showed that prions produced by mice expressing only anchorless PrP were more infectious than prions produced in mice expressing anchored PrP. Thus, the lack of the GPI anchor on prions reduced the effect of the mouse-human species barrier. Our results suggest that prion diseases that produce higher levels of anchorless PrP may pose an increased risk for cross-species infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Molecular Dynamics Simulation Study on the Binding and Stabilization Mechanism of Antiprion Compounds to the "Hot Spot" Region of PrPC.

PubMed

Zhou, Shuangyan; Liu, Xuewei; An, Xiaoli; Yao, Xiaojun; Liu, Huanxiang

2017-11-15

Structural transitions in the prion protein from the cellular form, PrP C , into the pathological isoform, PrP Sc , are regarded as the main cause of the transmissible spongiform encephalopathies, also known as prion diseases. Hence, discovering and designing effective antiprion drugs that can inhibit PrP C to PrP Sc conversion is regarded as a promising way to cure prion disease. Among several strategies to inhibit PrP C to PrP Sc conversion, stabilizing the native PrP C via specific binding is believed to be one of the valuable approaches and many antiprion compounds have been reported based on this strategy. However, the detailed mechanism to stabilize the native PrP C is still unknown. As such, to unravel the stabilizing mechanism of these compounds to PrP C is valuable for the further design and discovery of antiprion compounds. In this study, by molecular dynamics simulation method, we investigated the stabilizing mechanism of several antiprion compounds on PrP C that were previously reported to have specific binding to the "hot spot" region of PrP C . Our simulation results reveal that the stabilization mechanism of specific binding compounds can be summarized as (I) to stabilize both the flexible C-terminal of α2 and the hydrophobic core, such as BMD42-29 and GN8; (II) to stabilize the hydrophobic core, such as J1 and GJP49; (III) to stabilize the overall structure of PrP C by high binding affinity, as NPR-056. In addition, as indicated by the H-bond analysis and decomposition analysis of binding free energy, the residues N159 and Q160 play an important role in the specific binding of the studied compounds and all these compounds interact with PrP C in a similar way with the key interacting residues L130 in the β1 strand, P158, N159, Q160, etc. in the α1-β2 loop, and H187, T190, T191, etc. in the α2 C-terminus although the compounds have large structural difference. As a whole, our obtained results can provide some insights into the specific binding mechanism of main antiprion compounds to the "hot spot" region of PrP C at the molecular level and also provide guidance for effective antiprion drug design in the future.

Allografts with autogenous platelet-rich plasma for tibial defect reconstruction: a rabbit study.

PubMed

Nather, Aziz; Wong, Keng Lin; David, Vikram; Pereira, Barry P

2012-12-01

To evaluate the effect of autogenous platelet-rich plasma (PRP) for fresh-frozen allografts in tibial defect reconstruction in rabbits. 40 adult New Zealand white rabbits underwent tibial defect reconstruction with autografts (n=12), allografts without PRP (n=12), or allografts with PRP (n=12) and were observed for 12, 16, and 24 weeks (4 for each period). Tibias of the remaining 4 rabbits were used as donor allografts, and the remaining allografts were procured from recipient rabbits. A 1.5- cm cortical segment of the tibia was osteotomised, and then fixed with a 9-hole mini-compression plate and 2 cerclage wires. Allografts were stripped off the periosteum and soft tissues and medullary contents, and then stored in a freezer at -80 ºC. All allografts were deep frozen for at least 4 weeks before transplantation. 7 ml of whole blood was drawn to prepare 1 ml of PRP. The PRP was then mixed with 1.0 ml of human thrombin to form a platelet gel. The PRP gel was then packed into the medullary canal of the allograft and applied on the cortical surface before tibial defect reconstruction. Rabbits were sacrificed at 12, 16, and 24 weeks. The specimens were assessed for bone union at host-graft junctions and for bone resorption, new bone formation, callus encasement, and viable osteocyte counts. There were 4 specimens in each group at each observation period. Osteoid bridging the gap at host-graft junctions was noted in all specimens in the autograft and allograft-with-PRP groups at week 12 and in the allograft-without-PRP group at week 24. Bone union in allografts without PRP was delayed. All indices for biological incorporation (resorption index, new bone formation index, callus encasement index, and viable osteocyte count) were significantly greater in the autograft than allograft-without-PRP groups, except for the resorption index at week 24, whereas the differences were not significant between the autograft and allograft-with-PRP groups. The differences between the 2 allograft groups were usually not significant, except for the resorption index. PRP-augmented allografts behaved similarly to autografts for tibial defect reconstruction in rabbits. PRP increased bone union and bone resorption.

CD36 Participates in PrP106–126-Induced Activation of Microglia

PubMed Central

Tan, Rongrong; Shi, Fushan; Lu, Yun; Zhang, Siming; Yin, Xiaomin; Zhou, Xiangmei; Zhao, Deming

2012-01-01

Microglial activation is a characteristic feature of the pathogenesis of prion diseases. The molecular mechanisms that underlie prion-induced microglial activation are not very well understood. In the present study, we investigated the role of the class B scavenger receptor CD36 in microglial activation induced by neurotoxic prion protein (PrP) fragment 106–126 (PrP106–126). We first examined the time course of CD36 mRNA expression upon exposure to PrP106–126 in BV2 microglia. We then analyzed different parameters of microglial activation in PrP106–126-treated cells in the presence or not of anti-CD36 monoclonal antibody (mAb). The cells were first incubated for 1 h with CD36 monoclonal antibody to block the CD36 receptor, and were then treated with neurotoxic prion peptides PrP106–126. The results showed that PrP106–126 treatment led to a rapid yet transitory increase in the mRNA expression of CD36, upregulated mRNA and protein levels of proinflammatory cytokines (IL-1β, IL-6 and TNF-α), increased iNOS expression and nitric oxide (NO) production, stimulated the activation of NF-κB and caspase-1, and elevated Fyn activity. The blockade of CD36 had no effect on PrP106–126-stimulated NF-κB activation and TNF-α protein release, abrogated the PrP106–126-induced iNOS stimulation, downregulated IL-1β and IL-6 expression at both mRNA and protein levels as well as TNF-α mRNA expression, decreased NO production and Fyn phosphorylation, reduced caspase-1 cleavage induced by moderate PrP106–126 –treatment, but had no effect on caspase-1 activation after treatment with a high concentration of PrP106–126. Together, these results suggest that CD36 is involved in PrP106–126-induced microglial activation and that the participation of CD36 in the interaction between PrP106–126 and microglia may be mediated by Src tyrosine kinases. Our findings provide new insights into the mechanisms underlying the activation of microglia by neurotoxic prion peptides and open perspectives for new therapeutic strategies for prion diseases by modulation of CD36 signaling. PMID:22292032

Efficacy of Intra-articular Platelet-Rich Plasma Injections in Knee Osteoarthritis: A Systematic Review.

PubMed

Meheux, Carlos J; McCulloch, Patrick C; Lintner, David M; Varner, Kevin E; Harris, Joshua D

2016-03-01

To determine (1) whether platelet-rich plasma (PRP) injection significantly improves validated patient-reported outcomes in patients with symptomatic knee osteoarthritis (OA) at 6 and 12 months postinjection, (2) differences in outcomes between PRP and corticosteroid injections or viscosupplementation or placebo injections at 6 and 12 months postinjection, and (3) similarities and differences in outcomes based on the PRP formulations used in the analyzed studies. PubMed, Cochrane Central Register of Controlled Trials, SCOPUS, and Sport Discus were searched for English-language, level I evidence, human in vivo studies on the treatment of symptomatic knee OA with intra-articular PRP compared with other options, with a minimum of 6 months of follow-up. A quality assessment of all articles was performed using the Modified Coleman Methodology Score (average, 83.3/100), and outcomes were analyzed using 2-proportion z-tests. Six articles (739 patients, 817 knees, 39% males, mean age of 59.9 years, with 38 weeks average follow-up) were analyzed. All studies met minimal clinical important difference criteria and showed significant improvements in statistical and clinical outcomes, including pain, physical function, and stiffness, with PRP. All but one study showed significant differences in clinical outcomes between PRP and hyaluronic acid (HA) or PRP and placebo in pain and function. Average pretreatment Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were 52.36 and 52.05 for the PRP and HA groups, respectively (P = .420). Mean post-treatment WOMAC scores for PRP were significantly better than for HA at 3 to 6 months (28.5 and 43.4, respectively; P = .0008) and at 6 to 12 months (22.8 and 38.1, respectively; P = .0062). None of the included studies used corticosteroids. In patients with symptomatic knee OA, PRP injection results in significant clinical improvements up to 12 months postinjection. Clinical outcomes and WOMAC scores are significantly better after PRP versus HA at 3 to 12 months postinjection. There is limited evidence for comparing leukocyte-rich versus leukocyte-poor PRP or PRP versus steroids in this study. Level I, systematic review of Level I studies. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses.

PubMed

Zhang, J; Yuan, T; Zheng, N; Zhou, Y; Hogan, M V; Wang, J H-C

2017-04-01

After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP). Wounds created in rat ATEs were given three different treatments: kartogenin platelet-rich plasma (KGN-PRP); PRP; or saline (control), followed by histological and immunochemical analyses, and mechanical testing of the rat ATEs after three months of healing. Histological analysis showed well organised arrangement of collagen fibres and proteoglycan formation in the wounded ATEs in the KGN-PRP group. Furthermore, immunohistochemical analysis revealed fibrocartilage formation in the KGN-PRP-treated ATEs, evidenced by the presence of both collagen I and II in the healed ATE. Larger positively stained collagen III areas were found in both PRP and saline groups than those in the KGN-PRP group. Chondrocyte-related genes, SOX9 and collagen II, and tenocyte-related genes, collagen I and scleraxis (SCX), were also upregulated by KGN-PRP. Moreover, mechanical testing results showed higher ultimate tensile strength in the KGN-PRP group than in the saline control group. In contrast, PRP treatment appeared to have healed the injured ATE but induced no apparent formation of fibrocartilage. The saline-treated group showed poor healing without fibrocartilage tissue formation in the ATEs. Our results show that injection of KGN-PRP induces fibrocartilage formation in the wounded rat ATEs. Hence, KGN-PRP may be a clinically relevant, biological approach to regenerate injured enthesis effectively. Cite this article: J. Zhang, T. Yuan, N. Zheng, Y. Zhou, M. V. Hogan, J. H-C. Wang. The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses. Bone Joint Res 2017;6:231-244. DOI: 10.1302/2046-3758.64.BJR-2017-0268.R1. © 2017 Wang et al.

Platelet-rich plasma (PRP) in dental and oral surgery: from the wound healing to bone regeneration

PubMed Central

2013-01-01

Platelet-rich plasma (PRP) is a new approach to tissue regeneration and it is becoming a valuable adjunct to promote healing in many procedures in dental and oral surgery, especially in aging patients. PRP derives from the centrifugation of the patient's own blood and it contains growth factors that influence wound healing, thereby playing an important role in tissue repairing mechanisms. The use of PRP in surgical practice could have beneficial outcomes, reducing bleeding and enhancing soft tissue healing and bone regeneration. Studies conducted on humans have yielded promising results regarding the application of PRP to many dental and oral surgical procedures (i.e. tooth extractions, periodontal surgery, implant surgery). The use of PRP has also been proposed in the management of bisphosphonate-related osteonecrosis of the jaw (BRONJ) with the aim of enhancing wound healing and bone maturation. The aims of this narrative review are: i) to describe the different uses of PRP in dental surgery (tooth extractions and periodontal surgery) and oral surgery (soft tissues and bone tissue surgery, implant surgery and BRONJ surgery); and ii) to discuss its efficacy, efficiency and risk/benefit ratio. This review suggests that the use of PRP in the alveolar socket after tooth extractions is certainly capable of improving soft tissue healing and positively influencing bone regeneration but the latter effect seems to decrease a few days after the extraction. PRP has produced better results in periodontal therapy in association with other materials than when it is used alone. Promising results have also been obtained in implant surgery, when PRP was used in isolation as a coating material. The combination of necrotic bone curettage and PRP application seem to be encouraging for the treatment of refractory BRONJ, as it has proven successful outcomes with minimal invasivity. Since PRP is free from potential risks for patients, not difficult to obtain and use, it can be employed as a valid adjunct in many procedures in oral and dental surgery. However, further RCTs are required to support this evidence. PMID:23763951

Platelet-rich plasma (PRP) in dental and oral surgery: from the wound healing to bone regeneration.

PubMed

Albanese, Antonino; Licata, Maria E; Polizzi, Bianca; Campisi, Giuseppina

2013-06-13

Platelet-rich plasma (PRP) is a new approach to tissue regeneration and it is becoming a valuable adjunct to promote healing in many procedures in dental and oral surgery, especially in aging patients. PRP derives from the centrifugation of the patient's own blood and it contains growth factors that influence wound healing, thereby playing an important role in tissue repairing mechanisms. The use of PRP in surgical practice could have beneficial outcomes, reducing bleeding and enhancing soft tissue healing and bone regeneration. Studies conducted on humans have yielded promising results regarding the application of PRP to many dental and oral surgical procedures (i.e. tooth extractions, periodontal surgery, implant surgery). The use of PRP has also been proposed in the management of bisphosphonate-related osteonecrosis of the jaw (BRONJ) with the aim of enhancing wound healing and bone maturation. The aims of this narrative review are: i) to describe the different uses of PRP in dental surgery (tooth extractions and periodontal surgery) and oral surgery (soft tissues and bone tissue surgery, implant surgery and BRONJ surgery); and ii) to discuss its efficacy, efficiency and risk/benefit ratio. This review suggests that the use of PRP in the alveolar socket after tooth extractions is certainly capable of improving soft tissue healing and positively influencing bone regeneration but the latter effect seems to decrease a few days after the extraction. PRP has produced better results in periodontal therapy in association with other materials than when it is used alone. Promising results have also been obtained in implant surgery, when PRP was used in isolation as a coating material. The combination of necrotic bone curettage and PRP application seem to be encouraging for the treatment of refractory BRONJ, as it has proven successful outcomes with minimal invasivity. Since PRP is free from potential risks for patients, not difficult to obtain and use, it can be employed as a valid adjunct in many procedures in oral and dental surgery. However, further RCTs are required to support this evidence.

A Randomized Controlled Study of a Fully Liquid DTaP-IPV-HB-PRP-T Hexavalent Vaccine for Primary and Booster Vaccinations of Healthy Infants and Toddlers in Latin America.

PubMed

López, Pío; Arguedas Mohs, Adriano; Abdelnour Vásquez, Arturo; Consuelo-Miranda, Maria; Feroldi, Emmanuel; Noriega, Fernando; Jordanov, Emilia; B Chir, Siham; Zambrano, Betzana

2017-11-01

Hexavalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus-hepatitis B-Haemophilus influenzae type b (DTaP-IPV-HB-PRP-T)-containing vaccines are increasingly the standard of care. This study evaluated the primary series (NCT01177722) and booster (NCT01444781) of a fully liquid DTaP-IPV-HB-PRP-T vaccine in Latin America. Infants (N = 1375) received hepatitis B vaccine at birth and were randomized to one of 3 batches of the investigational DTaP-IPV-HB-PRP-T or licensed control vaccine (DTaP-HB-IPV//PRP-T) at 2-4 to 6 months of age, coadministered with 7-valent pneumococcal conjugate vaccine (PCV7) (2-4-6 months) and rotavirus vaccine (2-4 months). A booster of either DTaP-IPV-HB-PRP-T or control was given at 12-24 months, coadministered with PCV7. Immunogenicity was assessed by validated assays and safety from parental reports. Primary series seroprotection and vaccine response rates were equivalent for DTaP-IPV-HB-PRP-T batches. For pooled batches, noninferiority to the control vaccine was demonstrated for each antigen. There were no descriptive differences in antibody persistence or booster response between DTaP-IPV-HB-PRP-T and the control. The booster responses to either vaccine following DTaP-IPV-HB-PRP-T primary series or to DTaP-IPV-HB-PRP-T following a control vaccine primary series were similar. The anti-aP component (filamentous hemagglutinin [FHA] and pertussis toxin [PT]) vaccine response and anti-Haemophilus influenzae type b (PRP) series seroprotection (≥0.15 µg/mL) rates were ≥73.0% after 2 primary series doses. Antipyretics had no effect on the immune response, and an extra (oral) polio vaccination had no effect on the antipolio booster response. Responses to PCV7 and rotavirus vaccine were similar for each coadministration. There were no safety concerns observed with any vaccine. These results confirm the suitability of the fully liquid DTaP-IPV-HB-PRP-T vaccine for primary and booster vaccination of infants.

The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses

PubMed Central

Zhang, J.; Yuan, T.; Zheng, N.; Zhou, Y.; Hogan, M. V.

2017-01-01

Objectives After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP). Methods Wounds created in rat ATEs were given three different treatments: kartogenin platelet-rich plasma (KGN-PRP); PRP; or saline (control), followed by histological and immunochemical analyses, and mechanical testing of the rat ATEs after three months of healing. Results Histological analysis showed well organised arrangement of collagen fibres and proteoglycan formation in the wounded ATEs in the KGN-PRP group. Furthermore, immunohistochemical analysis revealed fibrocartilage formation in the KGN-PRP-treated ATEs, evidenced by the presence of both collagen I and II in the healed ATE. Larger positively stained collagen III areas were found in both PRP and saline groups than those in the KGN-PRP group. Chondrocyte-related genes, SOX9 and collagen II, and tenocyte-related genes, collagen I and scleraxis (SCX), were also upregulated by KGN-PRP. Moreover, mechanical testing results showed higher ultimate tensile strength in the KGN-PRP group than in the saline control group. In contrast, PRP treatment appeared to have healed the injured ATE but induced no apparent formation of fibrocartilage. The saline-treated group showed poor healing without fibrocartilage tissue formation in the ATEs. Conclusions Our results show that injection of KGN-PRP induces fibrocartilage formation in the wounded rat ATEs. Hence, KGN-PRP may be a clinically relevant, biological approach to regenerate injured enthesis effectively. Cite this article: J. Zhang, T. Yuan, N. Zheng, Y. Zhou, M. V. Hogan, J. H-C. Wang. The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses. Bone Joint Res 2017;6:231–244. DOI: 10.1302/2046-3758.64.BJR-2017-0268.R1. PMID:28450316

Effect of Bone Marrow Aspirate Concentrate-Platelet-Rich Plasma on Tendon-Derived Stem Cells and Rotator Cuff Tendon Tear

PubMed Central

Kim, Sun Jeong; Song, Da Hyun; Park, Jong Wook; Park, Silvia; Kim, Sang Jun

2017-01-01

Bone marrow aspirate concentrates (BMACs) and platelet-rich plasma (PRP) are good sources to control the differentiation of tendon-derived stem cells (TDSCs), but there has been no study about the effect of the BMAC–PRP complex on TDSCs and tendinopathy. The aim of this study was to investigate the effect of BMAC–PRP on the TDSCs and to find the therapeutic effect of BMAC–PRP on the rotator cuff tendon tear. The chondrogenic and osteogenic potential of TDSCs decreased, but the adipogenic potential of TDSCs revealed no significant difference when they were cocultured with BMAC–PRP. Cell proliferation was significantly greater in TDSCs cocultured with BMAC–PRP than in TDSCs. The degree of wound closure (percentage) was different between TDSCs and TDSCs with BMAC–PRP. There was no significant difference in expression of collagen type I and type III in immunocytochemical staining in the presence of BMAC–PRP. Initial visual analog scale (VAS) score was 5.8±1.9, which changed to 5.0±2.3 at 3 weeks and 2.8±2.3 at 3 months after the BMAC–PRP injection (p<0.01). The American Shoulder Elbow Surgeon score changed from 39.4±13.0 at baseline to 52.9±22.9 at 3 weeks and 71.8±19.7 at 3 months after the injection (p<0.01). The initial torn area of the rotator cuff tendon was 30.2±24.5 mm2, and this area was reduced to 22.5±18.9 mm2 at 3 months, but the change was not significant (p > 0.05). The data indicate that BMAC–PRP enhances the proliferation and migration of TDSCs and prevents the aberrant chondrogenic and osteogenic differentiation of TDSCs, which might provide a mechanistic basis for the therapeutic benefits of BMAC–PRP for rotator cuff tendon tear. PMID:28105983

Does application of moderately concentrated platelet-rich plasma improve clinical and structural outcome after arthroscopic repair of medium-sized to large rotator cuff tear? A randomized controlled trial.

PubMed

Pandey, Vivek; Bandi, Atul; Madi, Sandesh; Agarwal, Lipisha; Acharya, Kiran K V; Maddukuri, Satish; Sambhaji, Charudutt; Willems, W Jaap

2016-08-01

Platelet-rich plasma (PRP) has the potential to improve tendon-bone healing. The evidence is still controversial as to whether PRP application after repair of medium-sized to large cuff tears leads to superior structural and clinical outcome, especially after single-row repair. In a randomized study, 102 patients (PRP group, 52 patients; control group, 50 patients) with medium-sized and large degenerative posterosuperior tears were included for arthroscopic repair with a minimum follow-up of 2 years. Patients were evaluated with clinical scores (visual analog scale score, Constant-Murley score, University of California-Los Angeles score, and American Shoulder and Elbow Surgeons score) and ultrasound to assess retear and vascularity pattern of the cuff. Visual analog scale scores were significantly lower in the PRP group than in controls at 1 month, 3 months, and 6 months but not later. Constant-Murley scores were significantly better in the PRP group compared with controls at 12 and 24 months, whereas University of California-Los Angeles scores were significantly higher in the PRP group at 6 and 12 months (P < .05). The American Shoulder and Elbow Surgeons score in both groups was comparable at all the times. At 24 months, retear in the PRP group (n = 2; 3.8%) was significantly lower than in the control group (n = 10; 20%; P = .01). The retear difference was significant only for large tears (PRP:control group, 1:6; P = .03). Doppler ultrasound examination showed significant vascularity in the PRP group repair site at 3 months postoperatively (P < .05) and in peribursal tissue until 12 months. Application of moderately concentrated PRP improves clinical and structural outcome in large cuff tears. PRP also enhances vascularity around the repair site in the early phase. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

An In Vitro Investigation of Platelet-Rich Plasma-Gel as a Cell and Growth Factor Delivery Vehicle for Tissue Engineering

PubMed Central

Jalowiec, Jagoda M.; D'Este, Matteo; Bara, Jennifer Jane; Denom, Jessica; Menzel, Ursula; Alini, Mauro; Herrmann, Marietta

2016-01-01

Platelet-rich plasma (PRP) has been used for different applications in human and veterinary medicine. Many studies have shown promising therapeutic effects of PRP; however, there are still many controversies regarding its composition, properties, and clinical efficacy. The aim of this study was to evaluate the influence of different platelet concentrations on the rheological properties and growth factor (GF) release profile of PRP-gels. In addition, the viability of incorporated bone marrow-derived human mesenchymal stem cells (MSCs) was investigated. PRP (containing 1000 × 103, 2000 × 103, and 10,000 × 103 platelets/μL) was prepared from human platelet concentrates. Platelet activation and gelification were achieved by addition of human thrombin. Viscoelastic properties of PRP-gels were evaluated by rheological studies. The release of GFs and inflammatory proteins was measured using a membrane-based protein array and enzyme-linked immunosorbent assay. MSC viability and proliferation in PRP-gels were assessed over 7 days by cell viability staining. Cell proliferation was examined using DNA quantification. Regardless of the platelet content, all tested PRP-gels showed effective cross-linking. A positive correlation between protein release and the platelet concentration was observed at all time points. Among the detected proteins, the chemokine CCL5 was the most abundant. The greatest release appeared within the first 4 h after gelification. MSCs could be successfully cultured in PRP-gels over 7 days, with the highest cell viability and DNA content found in PRP-gels with 1000 × 103 platelets/μL. The results of this study suggest that PRP-gels represent a suitable carrier for both cell and GF delivery for tissue engineering. Notably, a platelet concentration of 1000 × 103 platelets/μL appeared to provide the most favorable environment for MSCs. Thus, the platelet concentration is an important consideration for the clinical application of PRP-gels. PMID:26467221

Platelet-Rich Plasma in the Animal Long-Bone Model: An Analysis of Basic Science Evidence.

PubMed

Gianakos, Arianna; Zambrana, Lester; Savage-Elliott, Ian; Lane, Joseph M; Kennedy, John G

2015-12-01

Platelet-rich plasma (PRP) has been suggested as an adjunct to aid in long-bone healing. The purpose of this study was to systematically review the basic science in vivo evidence for the use of PRP in the treatment of bone pathology. The PubMed/MEDLINE and EMBASE databases were screened using the following search criteria: "(Platelet-rich plasma OR PRP OR autologous conditioned plasma OR ACP) AND (bone OR osteocytes OR osteogenesis OR nonunion OR delayed union)." Studies were included if they fulfilled the following criteria: (1) studied the effect of PRP or a similar concentrated platelet product, defined as a blood product with platelet concentration elevated to higher than baseline; (2) established a control with which to compare PRP; (3) were published in a peer-reviewed journal; and (4) looked specifically at animal long-bone models. All review articles and clinical studies, including randomized controlled trials and case series, were excluded from the review. Studies examining the effects of PRP on bones of animals with confounding pathology were excluded. In studies that contained additional treatment variables, only the portion of the experiment that compared PRP directly with the control were evaluated. Data were then extracted with a standardized table. The search yielded 29 articles for inclusion. Seventy-two percent of the studies reported platelet concentrations. Eighty-nine percent of studies reported significant improvement in earlier bone healing on histologic/histomorphometric assessment. One hundred percent showed significant increase in bone formation on radiographs in the PRP group. Eighty percent of studies reported a significant increase in bone area on microcomputed tomography. One hundred percent of studies showed a higher torsional stiffness for the PRP-treated defects. In the in vivo studies evaluated, PRP confers several beneficial effects on animal long-bone models. Proof of concept for PRP as a biologic adjunct in long-bone models has been determined. Copyright 2015, SLACK Incorporated.

Crystal structure, mutational analysis and RNA-dependent ATPase activity of the yeast DEAD-box pre-mRNA splicing factor Prp28

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacewicz, Agata; Schwer, Beate; Smith, Paul

Yeast Prp28 is a DEAD-box pre-mRNA splicing factor implicated in displacing U1 snRNP from the 5' splice site. Here we report that the 588-aa Prp28 protein consists of a trypsin-sensitive 126-aa N-terminal segment (of which aa 1–89 are dispensable for Prp28 function in vivo) fused to a trypsin-resistant C-terminal catalytic domain. Purified recombinant Prp28 and Prp28-(127–588) have an intrinsic RNA-dependent ATPase activity, albeit with a low turnover number. The crystal structure of Prp28-(127–588) comprises two RecA-like domains splayed widely apart. AMPPNP•Mg 2+ is engaged by the proximal domain, with proper and specific contacts from Phe194 and Gln201 (Q motif) tomore » the adenine nucleobase. The triphosphate moiety of AMPPNP•Mg 2+ is not poised for catalysis in the open domain conformation. Guided by the Prp28•AMPPNP structure, and that of the Drosophila Vasa•AMPPNP•Mg 2+•RNA complex, we targeted 20 positions in Prp28 for alanine scanning. ATP-site components Asp341 and Glu342 (motif II) and Arg527 and Arg530 (motif VI) and RNA-site constituent Arg476 (motif Va) are essential for Prp28 activity in vivo. Synthetic lethality of double-alanine mutations highlighted functionally redundant contacts in the ATP-binding (Phe194-Gln201, Gln201-Asp502) and RNA-binding (Arg264-Arg320) sites. As a result, overexpression of defective ATP-site mutants, but not defective RNA-site mutants, elicited severe dominant-negative growth defects.« less

Combined use of bone marrow-derived mesenchymal stromal cells (BM-MSCs) and platelet rich plasma (PRP) stimulates proliferation and differentiation of myoblasts in vitro: new therapeutic perspectives for skeletal muscle repair/regeneration.

PubMed

Sassoli, Chiara; Vallone, Larissa; Tani, Alessia; Chellini, Flaminia; Nosi, Daniele; Zecchi-Orlandini, Sandra

2018-06-01

Satellite cell-mediated skeletal muscle repair/regeneration is compromised in cases of extended damage. Bone marrow mesenchymal stromal cells (BM-MSCs) hold promise for muscle healing but some criticisms hamper their clinical application, including the need to avoid animal serum contamination for expansion and the scarce survival after transplant. In this context, platelet-rich plasma (PRP) could offer advantages. Here, we compare the effects of PRP or standard culture media on C2C12 myoblast, satellite cell and BM-MSC viability, survival, proliferation and myogenic differentiation and evaluate PRP/BM-MSC combination effects in promoting myogenic differentiation. PRP induced an increase of mitochondrial activity and Ki67 expression comparable or even greater than that elicited by standard media and promoted AKT signaling activation in myoblasts and BM-MSCs and Notch-1 pathway activation in BM-MSCs. It stimulated MyoD, myogenin, α-sarcomeric actin and MMP-2 expression in myoblasts and satellite cell activation. Notably, PRP/BM-MSC combination was more effective than PRP alone. We found that BM-MSCs influenced myoblast responses through a paracrine activation of AKT signaling, contributing to shed light on BM-MSC action mechanisms. Our results suggest that PRP represents a good serum substitute for BM-MSC manipulation in vitro and could be beneficial towards transplanted cells in vivo. Moreover, it might influence muscle resident progenitors' fate, thus favoring the endogenous repair/regeneration mechanisms. Finally, within the limitations of an in vitro experimentation, this study provides an experimental background for considering the PRP/BM-MSC combination as a potential therapeutic tool for skeletal muscle damage, combining the beneficial effects of BM-MSCs and PRP on muscle tissue, while potentiating BM-MSC functionality.

The effects of platelet apheresis on blood saving and coagulation in bilateral total hip replacement: A prospective study on 60 patients.

PubMed

Qu, Zhijun; Wang, Geng; Xu, Chengshi; Zhang, Dazhi; Qu, Xiangdong; Zhou, Haibin; Ma, Jun

2016-10-01

Preoperative platelet rich plasma (PRP) harvest has been used in cardiopulmonary surgery for more than 10 years. There is no previous study dealing with PRP in bilateral total hip replacement. This study was to investigate the effects of PRP on blood saving and blood coagulation function in patients with bilateral total hip replacement. A prospective, randomized, clinical trial was conducted. Sixty patients were enrolled, including 30 patients undergoing PRP in the PRP group and 30 controls. The surgery time, total transfusion volume, blood loss, allogenic blood transfusion, autologous blood transfusion, urine volume, drainage volume, some blood parameters (including Fibrinogen, D-dimer, Prothrombin time, international normalizedratio, activated partial thromboplastin time, Platelet, Haemoglobin B), thrombelastogram (TEG) and blood-gas parameters were studied in the perioperative stage. The measurement data were analyzed statistically. There was no statistical difference between the two groups in baseline characteristics, surgery time, total transfusion volume, blood loss, autologous blood transfusion, etc. Allogenic blood transfusion in the PRP group was less than the control group with statistical difference (p = 0.024). Fibrinogen in the PRP group was higher than the control group (p = 0.008). Among the TEG indicators, activated clotting time and coagulation time K in the PRP group were less than the control group. Clotting rate and maximum amplitude in the PRP group were higher. The blood-gas parameters presented no statistical difference. The results suggested that PRP probably played a positive role in blood coagulation function as well as blood saving in patients with bilateral total hip replacement. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Kartogenin with PRP promotes the formation of fibrocartilage zone in the tendon-bone interface.

PubMed

Zhou, Yiqin; Zhang, Jianying; Yang, Jinsong; Narava, Manoj; Zhao, Guangyi; Yuan, Ting; Wu, Haishan; Zheng, Nigel; Hogan, MaCalus V; Wang, James H-C

2017-12-01

Treatment of tendon-bone junction injuries is a challenge because tendon-bone interface often heals poorly and the fibrocartilage zone, which reduces stress concentration, at the interface is not formed. In this study, we used a compound called kartogenin (KGN) with platelet-rich plasma (PRP) to induce the formation of fibrocartilage zone in a rat tendon graft-bone tunnel model. The experimental rats received KGN-PRP or PRP injections in the tendon graft-bone tunnel interface. The control group received saline. After 4, 8 and 12 weeks, Safranin O staining of the tendon graft-bone tunnels revealed abundant proteoglycans in the KGN-PRP group indicating the formation of cartilage-like transition zone. Immunohistochemical and immuno-fluorescence staining revealed collagen types I (Col-I) and II (Col-II) in the newly formed fibrocartilage zone. Both fibrocartilage zone formation and maturation were healing time dependent. In contrast, the PRP and saline control groups had no cartilage-like tissues and minimal Col-I and Col-II staining. Some gaps were also present in the saline control group. Finally, pull-out strength in the KGN-PRP-treated group at 8 weeks was 1.4-fold higher than the PRP-treated group and 1.6-fold higher than the saline control group. These findings indicate that KGN, with PRP as a carrier, promotes the formation of fibrocartilage zone between the tendon graft and bone interface. Thus, KGN-PRP may be used as a convenient cell-free therapy in clinics to promote fibrocartilage zone formation in rotator calf repair and anterior cruciate ligament reconstruction, thereby enhancing the mechanical strength of the tendon-bone interface and hence the clinical outcome of these procedures. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Crystal structure, mutational analysis and RNA-dependent ATPase activity of the yeast DEAD-box pre-mRNA splicing factor Prp28

DOE PAGES

Jacewicz, Agata; Schwer, Beate; Smith, Paul; ...

2014-10-10

Yeast Prp28 is a DEAD-box pre-mRNA splicing factor implicated in displacing U1 snRNP from the 5' splice site. Here we report that the 588-aa Prp28 protein consists of a trypsin-sensitive 126-aa N-terminal segment (of which aa 1–89 are dispensable for Prp28 function in vivo) fused to a trypsin-resistant C-terminal catalytic domain. Purified recombinant Prp28 and Prp28-(127–588) have an intrinsic RNA-dependent ATPase activity, albeit with a low turnover number. The crystal structure of Prp28-(127–588) comprises two RecA-like domains splayed widely apart. AMPPNP•Mg 2+ is engaged by the proximal domain, with proper and specific contacts from Phe194 and Gln201 (Q motif) tomore » the adenine nucleobase. The triphosphate moiety of AMPPNP•Mg 2+ is not poised for catalysis in the open domain conformation. Guided by the Prp28•AMPPNP structure, and that of the Drosophila Vasa•AMPPNP•Mg 2+•RNA complex, we targeted 20 positions in Prp28 for alanine scanning. ATP-site components Asp341 and Glu342 (motif II) and Arg527 and Arg530 (motif VI) and RNA-site constituent Arg476 (motif Va) are essential for Prp28 activity in vivo. Synthetic lethality of double-alanine mutations highlighted functionally redundant contacts in the ATP-binding (Phe194-Gln201, Gln201-Asp502) and RNA-binding (Arg264-Arg320) sites. As a result, overexpression of defective ATP-site mutants, but not defective RNA-site mutants, elicited severe dominant-negative growth defects.« less

Evaluation of subcutaneous infiltration of autologous platelet-rich plasma on skin-wound healing in dogs

PubMed Central

Farghali, Haithem A.; AbdElKader, Naglaa A.; Khattab, Marwa S.

2017-01-01

Platelet-rich plasma (PRP) is known to be rich in growth factors and cytokines, which are crucial to the healing process. This study investigate the effect of subcutaneous (S/C) infiltration of autologous PRP at the wound boundaries on wound epithelization and contraction. Five adult male mongrel dogs were used. Bilateral acute full thickness skin wounds (3 cm diameter) were created on the thorax symmetrically. Right side wounds were subcutaneously infiltrated with activated PRP at day 0 and then every week for three consecutive weeks. The left wound was left as control. Wound contraction and epithelization were clinically evaluated. Expression of collagen type I (COLI) A2, (COLIA2),histopathology and immunohistochemical (IHC) staining of COLI α1 (COLIA1) were performed on skin biopsies at first, second and third weeks. The catalase activity, malondialdehyde (MDA) concentration and matrix metalloproteinase (MMP) 9 (MMP-9) activity were assessed in wound fluid samples. All data were analysed statistically. The epithelization percent significantly increased in the PRP-treated wound at week 3. Collagen was well organized in the PRP-treated wounds compared with control wounds at week 3. The COLIA2 expression and intensity of COLIA1 significantly increased in PRP-treated wounds. MDA concentration was significantly decreased in PRP-treated wound at week 3. The catalase activity exhibited no difference between PRP treated and untreated wounds. The activity of MMP-9 reached its peak at the second week and was significantly high in the PRP-treated group. S/C infiltration of autologous PRP at the wound margins enhances the wound epithelization and reduces the scar tissue formation. PMID:28246352

Evaluation of subcutaneous infiltration of autologous platelet-rich plasma on skin-wound healing in dogs.

PubMed

Farghali, Haithem A; AbdElKader, Naglaa A; Khattab, Marwa S; AbuBakr, Huda O

2017-04-28

Platelet-rich plasma (PRP) is known to be rich in growth factors and cytokines, which are crucial to the healing process. This study investigate the effect of subcutaneous (S/C) infiltration of autologous PRP at the wound boundaries on wound epithelization and contraction. Five adult male mongrel dogs were used. Bilateral acute full thickness skin wounds (3 cm diameter) were created on the thorax symmetrically. Right side wounds were subcutaneously infiltrated with activated PRP at day 0 and then every week for three consecutive weeks. The left wound was left as control. Wound contraction and epithelization were clinically evaluated. Expression of collagen type I (COLI) A2, (COLIA2),histopathology and immunohistochemical (IHC) staining of COLI α1 (COLIA1) were performed on skin biopsies at first, second and third weeks. The catalase activity, malondialdehyde (MDA) concentration and matrix metalloproteinase (MMP) 9 (MMP-9) activity were assessed in wound fluid samples. All data were analysed statistically. The epithelization percent significantly increased in the PRP-treated wound at week 3. Collagen was well organized in the PRP-treated wounds compared with control wounds at week 3. The COLIA2 expression and intensity of COLIA1 significantly increased in PRP-treated wounds. MDA concentration was significantly decreased in PRP-treated wound at week 3. The catalase activity exhibited no difference between PRP treated and untreated wounds. The activity of MMP-9 reached its peak at the second week and was significantly high in the PRP-treated group. S/C infiltration of autologous PRP at the wound margins enhances the wound epithelization and reduces the scar tissue formation. © 2017 The Author(s).

Platelet-rich plasma injection in the treatment of frozen shoulder: A randomized controlled trial with 6-month follow-up
.

PubMed

Lin, Junhong

2018-06-22

Platelet-rich plasma (PRP) has been utilized in the treatment of chronic injuries. The current study aimed to evaluate the efficiency of PRP in the treatment of frozen shoulder compared to procaine. 60 patients with frozen shoulder were randomly divided into two groups. The PRP group was injected with 2 mL prepared PRP, while in the control group procaine was used. The stretching and formal strengthening exercises were carried out in both groups during the 6-month follow-up. Visual analog scale (VAS) score was used to assess the subjective pain intensity of the patients. The general shoulder assessment instruments (University of California at Los Angeles (UCLA) shoulder scale) was applied to measure the shoulder function of the patients. The evaluation was performed before treatment and 1 week, 1 month, 3 months, and 6 months after the first injection. The efficiency of PRP was superior to and longer than procaine. VAS scores were both declined in PRP and control group after 1 week, 1 month, and 3 months of first injection. By contrast, it was elevated was elevated in the control group while continued to decline in PRP group. The UCLA scores were almost linearly improved in the PRP group, while the UCLA scores decreased to a lower level at the final follow-up visit compared to that post 3 months in the control group. PRP and procaine were effective in treating frozen shoulder. PRP was more effective and had a more prolonged efficiency than the procaine control. Nevertheless, the definite conclusion should come from further large-scale clinical trials.
.

Collaborative study on saccharide quantification of the Haemophilus influenzae type b component in liquid vaccine presentations.

PubMed

Rosskopf, U; Daas, A; Terao, E; von Hunolstein, C

2017-01-01

Before release onto the market, it must be demonstrated that the total and free polysaccharide (poly ribosyl-ribitol-phosphate, PRP) content of Haemophilus influenzae type b (Hib) vaccine complies with requirements. However, manufacturers use different methods to assay PRP content: a national control laboratory must establish and validate the relevant manufacturer methodology before using it to determine PRP content. An international study was organised by the World Health Organization (WHO), in collaboration with the Biological Standardisation Programme (BSP) of the Council of Europe/European Directorate for the Quality of Medicines & HealthCare (EDQM) and of the European Union Commission, to verify the suitability of a single method for determining PRP content in liquid pentavalent vaccines (DTwP-HepB-Hib) containing a whole-cell pertussis component. It consists of HCl hydrolysis followed by chromatographic separation and quantification of ribitol on a CarboPac MA1 column using high-performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD). The unconjugated, free, PRP is separated from the total PRP using C4 solid-phase extraction cartridges (SPE C4). Ten quality control laboratories performed two independent analyses applying the proposed analytical test protocol to five vaccine samples, including a vaccine lot with sub-potent PRP content and very high free PRP content. Both WHO PRP standard and ribitol reference standard were included as calibrating standards. A significant bias between WHO PRP standard and ribitol reference standard was observed. Study results showed that the proposed analytical method is, in principle, suitable for the intended use provided that a validation is performed as usually expected from quality control laboratories.

PRP for Degenerative Cartilage Disease: A Systematic Review of Clinical Studies

PubMed Central

Laver, Lior; Marom, Niv; Dnyanesh, Lad; Mei-Dan, Omer; Espregueira-Mendes, João; Gobbi, Alberto

2016-01-01

Objective: To explore the utilization of platelet-rich plasma (PRP) for degenerative cartilage processes and evaluate whether there is sufficient evidence to better define its potential effects. Design: Systematic literature reviews were conducted in PubMed/MEDLINE and Cochrane electronic databases till May 2015, using the keywords “platelet-rich plasma OR PRP OR autologous conditioned plasma OR ACP AND cartilage OR chondrocyte OR chondrogenesis OR osteoarthritis (OA) OR arthritis.” Results: The final result yielded 29 articles. Twenty-six studies examined PRP administration for knee OA and 3 involved PRP administration for hip OA. The results included 9 prospective randomized controlled trials (RCTs) (8 knee and 1 hip), 4 prospective comparative studies, 14 case series, and 2 retrospective comparative studies. Hyaluronic acid (HA) was used as a control in 11 studies (7 RCTs, 2 prospective comparative studies, and 2 retrospective cohort). Overall, all RCTs reported on improved symptoms compared to baseline scores. Only 2 RCTs—one for knee and one for hip—did not report significant superiority of PRP compared to the control group (HA). Nine out of 11 HA controlled studies showed significant better results in the PRP groups. A trend toward better results for PRP injections in patients with early knee OA and young age was observed; however, lack of uniformity was evident in terms of indications, inclusion criteria, and pathology definitions in the different studies. Conclusion: Current clinical evidence supports the benefit in PRP treatment for knee and hip OA, proven to temporarily relieve pain and improve function of the involved joint with superior results compared with several alternative treatments. Further research to establish the optimal preparation protocol and characteristics of PRP injections for OA is needed. PMID:28317389

Transition-metal prion protein attachment: Competition with copper

NASA Astrophysics Data System (ADS)

Hodak, Miroslav; Bernholc, Jerry

2012-02-01

Prion protein, PrP, is a protein capable of binding copper ions in multiple modes depending on their concentration. Misfolded PrP is implicated in a group of neurodegenerative diseases, which include ``mad cow disease'' and its human form, variant Creutzfeld-Jacob disease. An increasing amount of evidence suggests that attachment of non-copper metal ions to PrP triggers transformations to abnormal forms similar to those observed in prion diseases. In this work, we use hybrid Kohn-Sham/orbital-free density functional theory simulations to investigate copper replacement by other transition metals that bind to PrP, including zinc, iron and manganese. We consider all known copper binding modes in the N-terminal domain of PrP. Our calculations identify modes most susceptible to copper replacement and reveal metals that can successfully compete with copper for attachment to PrP.

Effects of pH and aggregation in the human prion conversion into scrapie form: a study using molecular dynamics with excited normal modes.

PubMed

Lima, Angelica Nakagawa; de Oliveira, Ronaldo Junio; Braz, Antônio Sérgio Kimus; de Souza Costa, Maurício Garcia; Perahia, David; Scott, Luis Paulo Barbour

2018-03-15

There are two different prion conformations: (1) the cellular natural (PrP C ) and (2) the scrapie (PrP Sc ), an infectious form that tends to aggregate under specific conditions. PrP C and PrP Sc are widely different regarding secondary and tertiary structures. PrP Sc contains more and longer β-strands compared to PrP C . The lack of solved PrP Sc structures precludes a proper understanding of the mechanisms related to the transition between cellular and scrapie forms, as well as the aggregation process. In order to investigate the conformational transition between PrP C and PrP Sc , we applied MDeNM (molecular dynamics with excited normal modes), an enhanced sampling simulation technique that has been recently developed to probe large structural changes. These simulations yielded new structural rearrangements of the cellular prion that would have been difficult to obtain with standard MD simulations. We observed an increase in β-sheet formation under low pH (≤ 4) and upon oligomerization, whose relevance was discussed on the basis of the energy landscape theory for protein folding. The characterization of intermediate structures corresponding to transition states allowed us to propose a conversion model from the cellular to the scrapie prion, which possibly ignites the fibril formation. This model can assist the design of new drugs to prevent neurological disorders related to the prion aggregation mechanism.

Autologous leukocyte-reduced platelet-rich plasma therapy for Achilles tendinopathy induced by collagenase in a rabbit model

PubMed Central

González, Juan C.; López, Catalina; Álvarez, María E.; Pérez, Jorge E.; Carmona, Jorge U.

2016-01-01

Leukocyte-reduced platelet-rich plasma (LR-PRP) is a therapy for tendinopathy of the Achilles tendon (TAT); however, there is scarce information regarding LR-PRP effects in rabbit models of TAT. We compared, at 4 and 12 weeks (w), the LR-PRP and placebo (PBS) effects on ultrasonography, histology and relative gene expression of collagen types I (COL1A1) and III (COL3A1) and vascular endothelial growth factor (VEGF) in 24 rabbits with TAT induced by collagenase. The rabbits (treated with both treatments) were euthanatised after either 4 or 12 w. A healthy group (HG (n = 6)) was included. At 4 and 12 w, the LR-PRP group had a no statistically different histology score to the HG. At w 4, the COL1A1 expression was significantly higher in the LR-PRP group when compared to HG, and the expression of COL3A1from both LR-PRP and PBS-treated tendons was significantly higher when compared to the HG. At w 12, the expression of COL3A1 remained significantly higher in the PBS group in comparison to the LR-PRP group and the HG. At w 4, the LR-PRP group presented a significantly higher expression of VEGF when compared to the PBS group and the HG. In conclusion, LR-PRP treatment showed regenerative properties in rabbits with TAT. PMID:26781753

Platelet-rich plasma versus steroid injection for subacromial impingement syndrome.

PubMed

Say, F; Gurler, D; Bulbul, M

2016-04-01

To compare the 6-week and 6-month outcome in 60 patients who received a single-dose injection of platelet-rich plasma (PRP) or steroid for subacromial impingement syndrome (SIS). 22 men and 38 women (mean age, 49.7 years) opted to receive a single-dose injection of PRP (n=30) or steroid (n=30) for SIS that had not responded to conservative treatment for >3 months. The PRP or a mixture of 1 ml 40 mg methylprednisolone and 8 ml prilocaine was administered via a dorsolateral approach through the interval just beneath the dorsal acromial edge. Both groups were instructed to perform standard rotator cuff stretching and strengthening exercises for 6 weeks. The use of non-steroid anti-inflammatory drugs was prohibited. Patients were evaluated before and 6 weeks and 6 months after treatment using the Constant score, visual analogue scale (VAS) for pain, and range of motion (ROM) of the shoulder. No local or systemic complication occurred. Improvement in the Constant score and VAS for pain at week 6 and month 6 was significantly better following steroid than PRP injection. The difference in the Constant score was greater than the mean clinically important difference of 10.4. Nonetheless, the 2 groups were comparable for improvement in ROM of the shoulder. Steroid injection was more effective than PRP injection for treatment of SIS in terms of the Constant score and VAS for pain at 6 weeks and 6 months.

Comparison between Conventional Mechanical Fixation and Use of Autologous Platelet Rich Plasma (PRP) in Wound Beds Prior to Resurfacing with Split Thickness Skin Graft.

PubMed

P Waiker, Veena; Shivalingappa, Shanthakumar

2015-01-01

Platelet rich plasma is known for its hemostatic, adhesive and healing properties in view of the multiple growth factors released from the platelets to the site of wound. The primary objective of this study was to use autologous platelet rich plasma (PRP) in wound beds for anchorage of skin grafts instead of conventional methods like sutures, staplers or glue. In a single center based randomized controlled prospective study of nine months duration, 200 patients with wounds were divided into two equal groups. Autologous PRP was applied on wound beds in PRP group and conventional methods like staples/sutures used to anchor the skin grafts in a control group. Instant graft adherence to wound bed was statistically significant in the PRP group. Time of first post-graft inspection was delayed, and hematoma, graft edema, discharge from graft site, frequency of dressings and duration of stay in plastic surgery unit were significantly less in the PRP group. Autologous PRP ensured instant skin graft adherence to wound bed in comparison to conventional methods of anchorage. Hence, we recommend the use of autologous PRP routinely on wounds prior to resurfacing to ensure the benefits of early healing.

Activation of platelet-rich plasma using thrombin receptor agonist peptide.

PubMed

Landesberg, Regina; Burke, Andrea; Pinsky, David; Katz, Ronald; Vo, Jennifer; Eisig, Sidney B; Lu, Helen H

2005-04-01

This study proposes an alternative preparation method of platelet-rich plasma (PRP). Specifically, we compare the use of thrombin receptor agonist peptide-6 (TRAP) and bovine thrombin as a clotting agent in the preparation of PRP. PRP was prepared by centrifugation and clotted with thrombin or TRAP. In vitro clotting times were monitored as a function of TRAP concentration, and clot retraction was determined by measuring clot diameter over time. Following the optimization of TRAP concentration, experiments were repeated with the addition of several commercially available bone substitutes. The release of PRP-relevant growth factors as a function of PRP preparation was also determined. The most rapid polymerization of PRP takes place with the addition of thrombin, followed by TRAP/Allogro (Ceramed, Lakewood, CO), TRAP/BioGlass (Mo-Sci, Rolla, MN), TRAP/BioOss (Osteohealth, Shirley, NY), and TRAP alone. Thrombin caused considerable clot retraction (43%), whereas TRAP alone resulted in only 15% retraction. TRAP/Allogro, TRAP/BioOss, and TRAP/BioGlass all exhibited minimal retraction (8%). The use of TRAP to activate clot formation in the preparation of PRP may be a safe alternative to bovine thrombin. It results in an excellent working time and significantly less clot retraction than the currently available methods of PRP production.

Loss of prion protein is associated with the development of insulin resistance and obesity.

PubMed

de Brito, Giovanna; Lupinacci, Fernanda C; Beraldo, Flávio H; Santos, Tiago G; Roffé, Martín; Lopes, Marilene H; de Lima, Vladmir C; Martins, Vilma R; Hajj, Glaucia N

2017-08-17

Prion protein (PrP C ) was initially described due to its involvement in transmissible spongiform encephalopathies. It was subsequently demonstrated to be a cell surface molecule involved in many physiological processes, such as vesicle trafficking. Here, we investigated the roles of PrP C in the response to insulin and obesity development. Two independent PrP C knockout (KO) and one PrP C overexpressing (TG20) mouse models were fed high-fat diets, and the development of insulin resistance and obesity was monitored. PrP C KO mice fed high-fat diets presented all of the symptoms associated with the development of insulin resistance: hyperglycemia, hyperinsulinemia, and obesity. Conversely, TG20 animals fed high-fat diets showed reduced weight and insulin resistance. Accordingly, the expression of peroxisome proliferator-activated receptor gamma (PPARγ) was reduced in PrP C KO mice and increased in TG20 animals. PrP C KO cells also presented reduced glucose uptake upon insulin stimulation, due to reduced translocation of the glucose transporter Glut4. Thus, our results suggest that PrP C reflects susceptibility to the development of insulin resistance and metabolic syndrome. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Application of platelet-rich plasma and platelet-rich fibrin in fat grafting: basic science and literature review.

PubMed

Liao, Han-Tsung; Marra, Kacey G; Rubin, J Peter

2014-08-01

Due to the natural properties of fat, fat grafting remains a popular procedure for soft tissue volume augmentation and reconstruction. However, clinical outcome varies and is technique dependent. Platelet-rich plasma (PRP) contains α-granules, from which multiple growth factors such as platelet-derived growth factor, transforming growth factor-β, vascular endothelial growth factor, and epidermal growth factor can be released after activation. In recent years, the scope of PRP therapies has extended from bone regeneration, wound healing, and healing of musculoskeletal injuries, to enhancement of fat graft survival. In this review, we focus on the definition of PRP, the different PRP preparation and activation methods, and growth factor concentrations. In addition, we discuss possible mechanisms for the role of PRP in fat grafting by reviewing in vitro studies with adipose-derived stem cells, preadipocytes, and adipocytes, and preclinical and clinical research. We also review platelet-rich fibrin, a so-called second generation PRP, and its slow-releasing biology and effects on fat grafts compared to PRP in both animal and clinical research. Finally, we provide a general foundation on which to critically evaluate earlier studies, discuss the limitations of previous research, and direct plans for future experiments to improve the optimal effects of PRP in fat grafting.

The influence of environmental variables on platelet concentration in horse platelet-rich plasma.

PubMed

Rinnovati, Riccardo; Romagnoli, Noemi; Gentilini, Fabio; Lambertini, Carlotta; Spadari, Alessandro

2016-07-04

Platelet-rich plasma (PRP) commonly refers to blood products which contain a higher platelet (PLT) concentration as compared to normal plasma. Autologous PRP has been shown to be safe and effective in promoting the natural processes of soft tissue healing or reconstruction in humans and horses. Variability in PLT concentration has been observed in practice between PRP preparations from different patients or from the same individual under different conditions. A change in PLT concentration could modify PRP efficacy in routine applications. The aim of this study was to test the influence of environmental, individual and agonistic variables on the PLT concentration of PRP in horses. Six healthy Standardbred mares were exposed to six different variables with a one-week washout period between variables, and PRP was subsequently obtained from each horse. The variables were time of withdrawal during the day (morning/evening), hydration status (overhydration/dehydration) treatment with anti-inflammatory drugs and training periods on a treadmill. The platelet concentration was significantly higher in horses treated with a non-steroidal anti-inflammatory drug (P = 0.03). The leukocyte concentration increased 2-9 fold with respect to whole blood in the PRP which was obtained after exposure to all the variable considered. Environmental variation in platelet concentration should be taken into consideration during PRP preparation.

Retrospective view of primary Raynaud's phenomenon in childhood.

PubMed

Turan, Enes; Kilic, Sara Sebnem

2018-02-06

Primary Raynaud's phenomenon (PRP) manifests as episodes of transient spasms of peripheral blood vessels. To elucidate the clinical clues and laboratory characteristics will facilitate the identification of PRP. A retrospective data collection of clinical and laboratory characteristics of 58 children with PRP was performed between January 2007 and December 2016. A positive ANA test at lower titers <1:100 was detected in 24.1% of the patients. There was a significant relationship between presence of ANA positivity and migraine in female patients with PRP (p=0.01; p=0.020 respectively). The most common accompanying disorder was migraine which was detected in 37.9% of all patients with PRP. Hemoglobin and serum ferritin levels were significantly lower in PRP patients with migraine (p=0.045; p<0.05, respectively). Additionally, the mean platelet volume (MPV) measurements were significantly higher in patients with migraine compared to those without migraine (p=0.045; p<0.05 respectively). There is limited data concerning childhood PRP. For the first time we showed a high frequency of migraine in childhood PRP. Anemia and high MPV could be the underlying triggering factors of these two episodic diseases. Copyright © 2018 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

Effect of autologous platelet-rich plasma application on cutaneous wound healing in dogs

PubMed Central

Jee, Cho-Hee; Eom, Na-Young; Jang, Hyo-Mi; Jung, Hae-Won; Choi, Eul-Soo; Won, Jin-Hee; Hong, Il-Hwa; Kang, Byeong-Teck

2016-01-01

This study was conducted to identify the effectiveness of platelet-rich plasma (PRP) and efficacy of intralesional injection as a method of application to acute cutaneous wounds in dogs. Healthy adult beagles (n = 3) were used in this study. Autologous PRP was separated from anticoagulant treated whole blood in three dogs. Cutaneous wounds were created and then treated by intralesional injection of PRP in the experimental group, while they were treated with saline in the control group on days 0, 2 and 4. The healing process was evaluated by gross examination throughout the experimental period and histologic examination on day 7, 14 and 21. In PRP treated wounds, the mean diameter was smaller and the wound closure rate was higher than in the control. Histological study revealed that PRP treated wounds showed more granulation formation and angiogenesis on day 7, and faster epithelialization, more granulation formation and collagen deposition were observed on day 14 than in control wounds. On day 21, collagen deposition and epithelialization were enhanced in PRP treated groups. Overall, PRP application showed beneficial effects in wound healing, and intralesional injection was useful for application of PRP and could be a good therapeutic option for wound management in dogs. PMID:27051343

Multiple protein–protein interactions converging on the Prp38 protein during activation of the human spliceosome

PubMed Central

Schütze, Tonio; Ulrich, Alexander K.C.; Apelt, Luise; Will, Cindy L.; Bartlick, Natascha; Seeger, Martin; Weber, Gert; Lührmann, Reinhard; Stelzl, Ulrich; Wahl, Markus C.

2016-01-01

Spliceosomal Prp38 proteins contain a conserved amino-terminal domain, but only higher eukaryotic orthologs also harbor a carboxy-terminal RS domain, a hallmark of splicing regulatory SR proteins. We show by crystal structure analysis that the amino-terminal domain of human Prp38 is organized around three pairs of antiparallel α-helices and lacks similarities to RNA-binding domains found in canonical SR proteins. Instead, yeast two-hybrid analyses suggest that the amino-terminal domain is a versatile protein–protein interaction hub that possibly binds 12 other spliceosomal proteins, most of which are recruited at the same stage as Prp38. By quantitative, alanine surface-scanning two-hybrid screens and biochemical analyses we delineated four distinct interfaces on the Prp38 amino-terminal domain. In vitro interaction assays using recombinant proteins showed that Prp38 can bind at least two proteins simultaneously via two different interfaces. Addition of excess Prp38 amino-terminal domain to in vitro splicing assays, but not of an interaction-deficient mutant, stalled splicing at a precatalytic stage. Our results show that human Prp38 is an unusual SR protein, whose amino-terminal domain is a multi-interface protein–protein interaction platform that might organize the relative positioning of other proteins during splicing. PMID:26673105

Effect of Leukocyte-Rich and Platelet-Rich Plasma on Healing of a Horizontal Medial Meniscus Tear in a Rabbit Model

PubMed Central

Shin, Kyun Ho; Lee, Haseok; Kang, Seonghyun; Ko, You-Jin; Lee, Seung-Yup; Park, Jung-Ho; Bae, Ji-Hoon

2015-01-01

There are limited reports on the effect of platelet-rich plasma (PRP) on meniscus healing. The purpose of this study was to investigate the effect of leukocyte-rich PRP (L-PRP) on potential healing of the horizontal medial meniscus tears in a rabbit model. A horizontal medial meniscus tear was created in both knees of nine skeletally mature adult rabbits. Left or right knees were randomly assigned to a L-PRP group, or a control group. 0.5 mL of L-PRP from 10 mL of each rabbit's whole blood was prepared and injected into the horizontal tears in a L-PRP group. None was applied to the horizontal tears in a control group. The histological assessment of meniscus healing was performed at two, four, and six weeks after surgery. We found that there were no significant differences of quantitative histologic scoring between two groups at 2, 4, and 6 weeks after surgery (p > 0.05). This study failed to show the positive effect of single injection of L-PRP on enhancing healing of the horizontal medial meniscus tears in a rabbit model. Single injection of L-PRP into horizontal meniscus tears may not effectively enhance healing of horizontal medial meniscus tears. PMID:26180783

Insights into intragenic and extragenic effectors of prion propagation using chimeric prion proteins

PubMed Central

Kalastavadi, Tejas; Tank, Elizabeth MH

2008-01-01

The study of fungal prion proteins affords remarkable opportunities to elucidate both intragenic and extragenic effectors of prion propagation. The yeast prion protein Sup35 and the self-perpetuating [PSI+] prion state is one of the best characterized fungal prions. While there is little sequence homology among known prion proteins, one region of striking similarity exists between Sup35p and the mammalian prion protein PrP. This region is comprised of roughly five octapeptide repeats of similar composition. The expansion of the repeat region in PrP is associated with inherited prion diseases. In order to learn more about the effects of PrP repeat expansions on the structural properties of a protein that undergoes a similar transition to a self-perpetuating aggregate, we generated chimeric Sup35-PrP proteins. Using both in vivo and in vitro systems we described the effect of repeat length on protein misfolding, aggregation, amyloid formation and amyloid stability. We found that repeat expansions in the chimeric prion proteins increase the propensity to initiate prion propagation and enhance the formation of amyloid fibers without significantly altering fiber stability. PMID:19098443

Different Molecular Mechanisms Mediate Direct or Glia-Dependent Prion Protein Fragment 90-231 Neurotoxic Effects in Cerebellar Granule Neurons.

PubMed

Thellung, Stefano; Gatta, Elena; Pellistri, Francesca; Villa, Valentina; Corsaro, Alessandro; Nizzari, Mario; Robello, Mauro; Florio, Tullio

2017-10-01

Glia over-stimulation associates with amyloid deposition contributing to the progression of central nervous system neurodegenerative disorders. Here we analyze the molecular mechanisms mediating microglia-dependent neurotoxicity induced by prion protein (PrP)90-231, an amyloidogenic polypeptide corresponding to the protease-resistant portion of the pathological prion protein scrapie (PrP Sc ). PrP90-231 neurotoxicity is enhanced by the presence of microglia within neuronal culture, and associated to a rapid neuronal [Ca ++ ] i increase. Indeed, while in "pure" cerebellar granule neuron cultures, PrP90-231 causes a delayed intracellular Ca ++ entry mediated by the activation of NMDA receptors; when neuron and glia are co-cultured, a transient increase of [Ca ++ ] i occurs within seconds after treatment in both granule neurons and glial cells, then followed by a delayed and sustained [Ca ++ ] i raise, associated with the induction of the expression of inducible nitric oxide synthase and phagocytic NADPH oxidase. [Ca ++ ] i fast increase in neurons is dependent on the activation of multiple pathways since it is not only inhibited by the blockade of voltage-gated channel activity and NMDA receptors but also prevented by the inhibition of nitric oxide and PGE 2 release from glial cells. Thus, Ca ++ homeostasis alteration, directly induced by PrP90-231 in cerebellar granule cells, requires the activation of NMDA receptors, but is greatly enhanced by soluble molecules released by activated glia. In glia-enriched cerebellar granule cultures, the activation of inducible nitric oxide (iNOS) and NADPH oxidase represents the main mechanism of toxicity since their pharmacological inhibition prevented PrP90-231 neurotoxicity, whereas NMDA blockade by D(-)-2-amino-5-phosphonopentanoic acid is ineffective; conversely, in pure cerebellar granule cultures, NMDA blockade but not iNOS inhibition strongly reduced PrP90-231 neurotoxicity. These data indicate that amyloidogenic peptides induce neurotoxic signals via both direct neuron interaction and glia activation through different mechanisms responsible of calcium homeostasis disruption in neurons and potentiating each other: the activation of excitotoxic pathways via NMDA receptors and the release of radical species that establish an oxidative milieu.

Intra-articular Hyaluronic Acid (HA) and Platelet Rich Plasma (PRP) injection versus Hyaluronic acid (HA) injection alone in Patients with Grade III and IV Knee Osteoarthritis (OA): A Retrospective Study on Functional Outcome.

PubMed

Saturveithan, C; Premganesh, G; Fakhrizzaki, S; Mahathir, M; Karuna, K; Rauf, K; William, H; Akmal, H; Sivapathasundaram, N; Jaspreet, K

2016-07-01

Introduction: Intra-articular hyaluronic acid (HA) is widely utilized in the treatment of knee osteoarthritis whereas platelet rich plasma (PRP) enhances the regeneration of articular cartilage. This study analyses the efficacy of HA and PRP in grade III and IV knee osteoarthritis. Methodology: This is a cross sectional study with retrospective review of 64 patients (101 knees) which includes 56 knees injected with HA+ PRP, and 45 knees with HA only. Results: During the post six months International Knee Documentation Committee (IKDC) evaluation, HA+PRP group showed marked improvement of 24.33 compared to 12.15 in HA group. Decrement in visual analogue score (VAS) in HA+PRP was 1.9 compared to 0.8 in HA group. Conclusion: We propose intra-articular HA and PRP injections as an optional treatment modality in Grade III and IV knee osteoarthritis in terms of functional outcome and pain control for up to six months when arthroplasty is not an option.

Intra-articular Hyaluronic Acid (HA) and Platelet Rich Plasma (PRP) injection versus Hyaluronic acid (HA) injection alone in Patients with Grade III and IV Knee Osteoarthritis (OA): A Retrospective Study on Functional Outcome

PubMed Central

Premganesh, G; Fakhrizzaki, S; Mahathir, M; Karuna, K; Rauf, K; William, H; Akmal, H; Sivapathasundaram, N; Jaspreet, K

2016-01-01

Introduction: Intra-articular hyaluronic acid (HA) is widely utilized in the treatment of knee osteoarthritis whereas platelet rich plasma (PRP) enhances the regeneration of articular cartilage. This study analyses the efficacy of HA and PRP in grade III and IV knee osteoarthritis. Methodology: This is a cross sectional study with retrospective review of 64 patients (101 knees) which includes 56 knees injected with HA+ PRP, and 45 knees with HA only. Results: During the post six months International Knee Documentation Committee (IKDC) evaluation, HA+PRP group showed marked improvement of 24.33 compared to 12.15 in HA group. Decrement in visual analogue score (VAS) in HA+PRP was 1.9 compared to 0.8 in HA group. Conclusion: We propose intra-articular HA and PRP injections as an optional treatment modality in Grade III and IV knee osteoarthritis in terms of functional outcome and pain control for up to six months when arthroplasty is not an option. PMID:28435559

Platelet Rich Plasma and Hyaluronic Acid Blend for the Treatment of Osteoarthritis: Rheological and Biological Evaluation

PubMed Central

Russo, Fabrizio; D’Este, Matteo; Vadalà, Gianluca; Cattani, Caterina; Papalia, Rocco; Alini, Mauro; Denaro, Vincenzo

2016-01-01

Introduction Osteoarthritis (OA) is the most common musculoskeletal disease. Current treatments for OA are mainly symptomatic and inadequate since none results in restoration of fully functional cartilage. Hyaluronic Acid (HA) intra-articular injections are widely accepted for the treatment of pain associated to OA. The goal of HA viscosupplementation is to reduce pain and improve viscoelasticity of synovial fluid. Platelet-rich plasma (PRP) has been also employed to treat OA to possibly induce cartilage regeneration. The combination of HA and PRP could supply many advantages for tissue repair. Indeed, it conjugates HA viscosupplementation with PRP regenerative properties. The aim of this study was to evaluate the rheological and biological properties of different HA compositions in combination with PRP in order to identify (i) the viscoelastic features of the HA-PRP blends, (ii) their biological effect on osteoarthritic chondrocytes and (iii) HA formulations suitable for use in combination with PRP. Materials and Methods HA/PRP blends have been obtained mixing human PRP and three different HA at different concentrations: 1) Sinovial, 0.8% (SN); 2) Sinovial Forte 1.6% (SF); 3) Sinovial HL 3.2% (HL); 4) Hyalubrix 1.5% (HX). Combinations of phosphate buffered saline (PBS) and the four HA types were used as control. Rheological measurements were performed on an Anton PaarMCR-302 rheometer. Amplitude sweep, frequency sweep and rotational measurements were performed and viscoelastic properties were evaluated. The rheological data were validated performing the tests in presence of Bovine Serum Albumin (BSA) up to ultra-physiological concentration (7%). Primary osteoarthritic chondrocytes were cultured in vitro with the HA and PRP blends in the culture medium for one week. Cell viability, proliferation and glycosaminoglycan (GAG) content were assessed. Results PRP addition to HA leads to a decrease of viscoelastic shear moduli and increase of the crossover point, due to a pure dilution effect. For viscosupplements with HA concentration below 1% the viscoelasticity is mostly lost. Results were validated also in presence of proteins, which in synovial fluid are more abundant than HA. Chondrocytes proliferated overtime in all different culture conditions. The proliferation rate was higher in chondrocytes cultured in the media containing PRP compared to the cultures with different HA alone. GAG content was significantly higher in chondrocytes cultured in PRP and HL blend. Discussion We investigated the rheological and biological properties of four different HA concentrations when combined with PRP giving insights on viscoelastic and biological properties of a promising approach for future OA therapy. Our data demonstrate that PRP addition is not detrimental to the viscosupplementation effect of HA. Viscosupplements containing low HA concentration are not indicated for combination with PRP, as the viscoelastic properties are lost. Although having the same rheological behavior of SF and HX, HL was superior in stimulating extracellular matrix production in vitro. PMID:27310019

Biodegradable electrospun nanofibers coated with platelet-rich plasma for cell adhesion and proliferation

PubMed Central

Díaz-Gómez, Luis; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Silva, Maite; Dominguez, Fernando; Sheikh, Faheem A.; Cantu, Travis; Desai, Raj; Garcia, Vanessa L.; Macossay, Javier

2014-01-01

Biodegradable electrospun poly(ε-caprolactone) (PCL) scaffolds were coated with platelet-rich plasma (PRP) to improve cell adhesion and proliferation. PRP was obtained from human buffy coat, and tested on human adipose-derived mesenchymal stem cells (MSC) to confirm cell proliferation and cytocompatibility. Then, PRP was adsorbed on the PCL scaffolds via lyophilization, which resulted in uniform sponge-like coating of 2.85 (s.d. 0.14) mg/mg. The scaffolds were evaluated regarding mechanical properties (Young’s modulus, tensile stress and tensile strain), sustained release of total protein and growth factors (PDGF-BB, TGF-β1 and VEGF), and hemocompatibility. MSC seeded on the PRP-PCL nanofibers showed an increased adhesion and proliferation compared to pristine PCL fibers. Moreover, the adsorbed PRP enabled angiogenesis features observed as neovascularization in a chicken chorioallantoic membrane (CAM) model. Overall, these results suggest that PRP-PCL scaffolds hold promise for tissue regeneration applications. PMID:24857481

Amyloid-β Peptide Induces Prion Protein Amyloid Formation: Evidence for Its Widespread Amyloidogenic Effect.

PubMed

Honda, Ryo

2018-04-12

Transmissible spongiform encephalopathy is associated with misfolding of prion protein (PrP) into an amyloid β-rich aggregate. Previous studies have indicated that PrP interacts with Alzheimer's disease amyloid-β peptide (Aβ), but it remains elusive how this interaction impacts on the misfolding of PrP. This study presents the first in vitro evidence that Aβ induces PrP-amyloid formation at submicromolar concentrations. Interestingly, systematic mutagenesis of PrP revealed that Aβ requires no specific amino acid sequences in PrP, and induces the misfolding of other unrelated proteins (insulin and lysozyme) into amyloid fibrils in a manner analogous to PrP. This unanticipated nonspecific amyloidogenic effect of Aβ indicates that this peptide might be involved in widespread protein aggregation, regardless of the amino acid sequences of target proteins, and exacerbate the pathology of many neurodegenerative diseases. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Melanin or a Melanin-Like Substance Interacts with the N-Terminal Portion of Prion Protein and Inhibits Abnormal Prion Protein Formation in Prion-Infected Cells.

PubMed

Hamanaka, Taichi; Nishizawa, Keiko; Sakasegawa, Yuji; Oguma, Ayumi; Teruya, Kenta; Kurahashi, Hiroshi; Hara, Hideyuki; Sakaguchi, Suehiro; Doh-Ura, Katsumi

2017-03-15

Prion diseases are progressive fatal neurodegenerative illnesses caused by the accumulation of transmissible abnormal prion protein (PrP). To find treatments for prion diseases, we searched for substances from natural resources that inhibit abnormal PrP formation in prion-infected cells. We found that high-molecular-weight components from insect cuticle extracts reduced abnormal PrP levels. The chemical nature of these components was consistent with that of melanin. In fact, synthetic melanin produced from tyrosine or 3-hydroxy-l-tyrosine inhibited abnormal PrP formation. Melanin did not modify cellular or cell surface PrP levels, nor did it modify lipid raft or cellular cholesterol levels. Neither did it enhance autophagy or lysosomal function. Melanin was capable of interacting with PrP at two N-terminal domains. Specifically, it strongly interacted with the PrP region of amino acids 23 to 50 including a positively charged amino acid cluster and weakly interacted with the PrP octarepeat peptide region of residues 51 to 90. However, the in vitro and in vivo data were inconsistent with those of prion-infected cells. Abnormal PrP formation in protein misfolding cyclic amplification was not inhibited by melanin. Survival after prion infection was not significantly altered in albino mice or exogenously melanin-injected mice compared with that of control mice. These data suggest that melanin, a main determinant of skin color, is not likely to modify prion disease pathogenesis, even though racial differences in the incidence of human prion diseases have been reported. Thus, the findings identify an interaction between melanin and the N terminus of PrP, but the pathophysiological roles of the PrP-melanin interaction remain unclear. IMPORTANCE The N-terminal region of PrP is reportedly important for neuroprotection, neurotoxicity, and abnormal PrP formation, as this region is bound by many factors, such as metal ions, lipids, nucleic acids, antiprion compounds, and several proteins, including abnormal PrP in prion disease and the Aβ oligomer in Alzheimer's disease. In the present study, melanin, a main determinant of skin color, was newly found to interact with this N-terminal region and inhibits abnormal PrP formation in prion-infected cells. However, the data for prion infection in mice lacking melanin production suggest that melanin is not associated with the prion disease mechanism, although the incidence of prion disease is reportedly much higher in white people than in black people. Thus, the roles of the PrP-melanin interaction remain to be further elucidated, but melanin might be a useful competitive tool for evaluating the functions of other ligands at the N-terminal region. Copyright © 2017 American Society for Microbiology.

Melanin or a Melanin-Like Substance Interacts with the N-Terminal Portion of Prion Protein and Inhibits Abnormal Prion Protein Formation in Prion-Infected Cells

PubMed Central

Hamanaka, Taichi; Nishizawa, Keiko; Sakasegawa, Yuji; Oguma, Ayumi; Teruya, Kenta; Kurahashi, Hiroshi; Hara, Hideyuki; Sakaguchi, Suehiro

2017-01-01

ABSTRACT Prion diseases are progressive fatal neurodegenerative illnesses caused by the accumulation of transmissible abnormal prion protein (PrP). To find treatments for prion diseases, we searched for substances from natural resources that inhibit abnormal PrP formation in prion-infected cells. We found that high-molecular-weight components from insect cuticle extracts reduced abnormal PrP levels. The chemical nature of these components was consistent with that of melanin. In fact, synthetic melanin produced from tyrosine or 3-hydroxy-l-tyrosine inhibited abnormal PrP formation. Melanin did not modify cellular or cell surface PrP levels, nor did it modify lipid raft or cellular cholesterol levels. Neither did it enhance autophagy or lysosomal function. Melanin was capable of interacting with PrP at two N-terminal domains. Specifically, it strongly interacted with the PrP region of amino acids 23 to 50 including a positively charged amino acid cluster and weakly interacted with the PrP octarepeat peptide region of residues 51 to 90. However, the in vitro and in vivo data were inconsistent with those of prion-infected cells. Abnormal PrP formation in protein misfolding cyclic amplification was not inhibited by melanin. Survival after prion infection was not significantly altered in albino mice or exogenously melanin-injected mice compared with that of control mice. These data suggest that melanin, a main determinant of skin color, is not likely to modify prion disease pathogenesis, even though racial differences in the incidence of human prion diseases have been reported. Thus, the findings identify an interaction between melanin and the N terminus of PrP, but the pathophysiological roles of the PrP-melanin interaction remain unclear. IMPORTANCE The N-terminal region of PrP is reportedly important for neuroprotection, neurotoxicity, and abnormal PrP formation, as this region is bound by many factors, such as metal ions, lipids, nucleic acids, antiprion compounds, and several proteins, including abnormal PrP in prion disease and the Aβ oligomer in Alzheimer's disease. In the present study, melanin, a main determinant of skin color, was newly found to interact with this N-terminal region and inhibits abnormal PrP formation in prion-infected cells. However, the data for prion infection in mice lacking melanin production suggest that melanin is not associated with the prion disease mechanism, although the incidence of prion disease is reportedly much higher in white people than in black people. Thus, the roles of the PrP-melanin interaction remain to be further elucidated, but melanin might be a useful competitive tool for evaluating the functions of other ligands at the N-terminal region. PMID:28077650

A single dose of platelet-rich plasma improves the organization and strength of a surgically repaired rotator cuff tendon in rats.

PubMed

Dolkart, Oleg; Chechik, Ofir; Zarfati, Yaron; Brosh, Tamar; Alhajajra, Fadi; Maman, Eran

2014-09-01

Rotator cuff tear (RCT) is a common cause of pain and disability among adults. Platelet-rich plasma (PRP) is a fraction of whole blood containing concentrated growth factors and proteins important for tissue healing. This study aimed at investigating the effects of local autologous PRP injection on repaired rotator cuff (RC) tendon repair in rats. Following experimental RCT and suturing, 44 Wistar rats were randomly allocated into two groups: (1) RC repair only (controls); (2) RC repair + PRP administration-shoulders were treated with intra-articular PRP immediately after the repair. Animals were killed after 3 weeks and tendon, were tested biomechanically in tension (12 rats/group). The remaining tendons (10 rats/group) were stained using hematoxylin and eosin and Picro-sirius Red. Histological analysis evaluated the cellular aspects of the repair tissue. PRP administration following experimental RC tear and suture resulted in a significantly higher maximal load (p < 0.001) and stiffness (p < 0.005) as compared to non-treated animals. Bonar score of PRP-treated tendons was significantly better (p = 0.018) than the control group. Collagen birefringence was significantly higher in PRP shoulders (p = 0.002), indicating improved organization. Vascularity scores were similar in both groups. Application of a single dose autologous PRP in adjunct to surgical repair resultes in improved tendon-to-bone healing, assessed by histological and biomechanical testing in a rat model of acute RCT, when tested at 3 weeks compared to controls. Further studies will be essential to determine the role of PRP in clinical practice.

Direct and indirect effects of a combination of adipose-derived stem cells and platelet-rich plasma on bone regeneration.

PubMed

Tajima, Satoshi; Tobita, Morikuni; Orbay, Hakan; Hyakusoku, Hiko; Mizuno, Hiroshi

2015-03-01

A key goal for successful bone regeneration is to bridge a bone defect using healing procedures that are stable and durable. Adipose-derived stem cells (ASCs) have the potential to differentiate into bone. Meanwhile, platelet-rich plasma (PRP) is an interesting biological means to repair tissue by inducing chemotactic, proliferative, and anabolic cellular responses. This study evaluated bone regeneration using a combination of ASCs and PRP in a rat calvarial defect model. ASCs were isolated from inguinal fat pads of F344 inbred rats, while PRP was prepared from these rats. ASCs were cultured in control medium supplemented with 10% fetal bovine serum or 5% PRP in vitro. After 1 week, levels of growth factors including insulin-like growth factor-1, transforming growth factor-β1, hepatocyte growth factor, and vascular endothelial growth factor in the culture supernatant were measured by enzyme-linked immunosorbent assays. Moreover, the ASC/PRP admixture was transplanted into the rat calvarial defect. Microcomputed tomography, histological, and immunohistochemical (osteopontin and osteocalcin) analyses were performed at 4 and 8 weeks after transplantation. The in vitro study showed that the levels of growth factors secreted by ASCs were significantly increased by the addition of PRP. Transplantation of the ASC/PRP admixture had dramatic effects on bone regeneration overtime in comparison with rats that received other transplants. Furthermore, some ASCs directly differentiated into osteogenic cells in vivo. These findings suggest that the combination of ASCs and PRP has augmentative effects on bone regeneration. The ASC/PRP admixture may be a promising source for the clinical treatment of cranial defects.

Effect of intralesional platelet-rich plasma (PRP) treatment on clinical and ultrasonographic parameters in equine naturally occurring superficial digital flexor tendinopathies - a randomized prospective controlled clinical trial.

PubMed

Geburek, Florian; Gaus, Moritz; van Schie, Hans T M; Rohn, Karl; Stadler, Peter M

2016-09-07

Regenerative and anti-inflammatory effects on tendinopathies have been attributed to blood-derived biologicals. To date the evidence for the efficacy of autologous platelet-rich plasma (PRP) treatment of naturally occurring equine tendinopathies is limited. The purpose of this placebo-controlled clinical trial was to describe the effect of a single treatment of equine superficial digital flexor tendon (SDFT) disease with PRP on clinical and ultrasonographic parameters. Twenty horses with naturally occurring tendinopathies of forelimb SDFTs were randomly assigned to the PRP-treated group (n = 10) or control group (n = 10) after clinical and ultrasonographic examination. The SDFTs received an intralesional treatment with autologous PRP or were injected with saline, respectively (day 0). All horses participated in a standardized exercise programme and were re-examined clinically, with B-mode ultrasonography (5 times at regular intervals) and ultrasound tissue characterization (week 12 and 24 after treatment) until week 24. Long-term performance was estimated via telephone inquiry. Compared to day 0, lameness decreased significantly by week 8 after treatment with PRP and by week 12 in the control group. Ultrasonographically there was no difference in the summarized cross sectional area between the groups at any time point. Ultrasound tissue characterization showed that echo types representing disorganized matrix decreased significantly throughout the observation period in the PRP-treated group. Echo type II, representing discontinuous fascicles, not yet aligned into lines of stress was significantly higher 24 weeks after PRP treatment. Eighty percent of the PRP treated horses reached their previous or a higher level of performance after 12 months compared to 50 % in the CG. After 24 months these proportions were 60 % and 50 %, respectively. A single intralesional treatment with PRP up to 8 weeks after onset of clinical signs of tendinopathy contributes to an earlier reduction of lameness compared to saline treatment and to an advanced organization of repair tissue as the fibrillar matrix is getting organized into fascicles while remodelling continues. Long term, PRP treatment has the potential to increase the number of horses reaching their previous level of performance. Earlier treatment of tendinopathy with PRP should be considered to enhance these effects.

Outcomes after Intravitreal Bevacizumab versus Laser Photocoagulation for Retinopathy of Prematurity: A 5-Year Retrospective Analysis

PubMed Central

Hwang, Christopher K.; Hubbard, G. Baker; Hutchinson, Amy K.; Lambert, Scott R.

2014-01-01

Purpose To determine the relative effectiveness, major complications, and refractive errors associated with intravitreal bevacizumab (IVB) versus panretinal photocoagulation (PRP) to treat Type 1 retinopathy of prematurity (ROP). Subjects Consecutive infants with Type 1 ROP who received either IVB or PRP between January 2008 and December 2012 and had at least six months of follow-up. Design Retrospective case series. Methods The data from infants treated with either IVB or PRP for Type 1 ROP between January 2008 and December 2012 were recorded from two medical centers in Atlanta, Georgia. Main Outcome Measures Recurrence rate, complication rate, refractive error. Results A total of 54 eyes (28 patients) with Type 1 ROP were evaluated: 22 eyes (11 patients) received IVB, and 32 eyes (17 patients) received PRP. Among the 22 eyes treated with IVB, 16 eyes had Zone I ROP and 6 eyes had posterior Zone II ROP. The number of Zone I and Zone II ROP eyes treated with PRP were 5 and 27 eyes, respectively. Mean gestational age, birth weight, postmenstrual age at the initial treatment, and follow-up period for the infants receiving IVB were 24.2 weeks, 668.1 grams, 35.1 weeks, and 21.7 weeks, respectively, and for the infants receiving PRP were 24.8, 701.4 grams, 36.1 weeks, and 34.5 weeks, respectively. ROP recurred in 3/22 (14%) IVB-treated eyes and in 1/32 (3%) PRP-treated eyes. None of IVB-treated eyes progressed to retinal detachment or developed macular ectopia. Only one eye went on to retinal detachment and five eyes developed macular ectopia in PRP-treated eyes. Mean spherical equivalent and postgestational age at the last refraction for IVB-treated eyes were −2.4 D and 22.4 months, respectively, and for PRP-treated eyes were −5.3 D and 37.1 months, respectively. Mean spherical equivalent for Zone I ROP eyes treated with IVB and PRP were −3.7 D and −10.1 D, respectively, and for Zone II ROP eyes were 0.6 D and −4.7 D, respectively. Conclusions Both IVB and PRP are effective treatment options for Type 1 ROP with low complication rates. Zone I ROP was associated with high minus refractive errors in eyes treated with either IVB or PRP. PMID:25687024

Different lasers and techniques for proliferative diabetic retinopathy.

PubMed

Moutray, Tanya; Evans, Jennifer R; Lois, Noemi; Armstrong, David J; Peto, Tunde; Azuara-Blanco, Augusto

2018-03-15

Diabetic retinopathy (DR) is a chronic progressive disease of the retinal microvasculature associated with prolonged hyperglycaemia. Proliferative DR (PDR) is a sight-threatening complication of DR and is characterised by the development of abnormal new vessels in the retina, optic nerve head or anterior segment of the eye. Argon laser photocoagulation has been the gold standard for the treatment of PDR for many years, using regimens evaluated by the Early Treatment of Diabetic Retinopathy Study (ETDRS). Over the years, there have been modifications of the technique and introduction of new laser technologies. To assess the effects of different types of laser, other than argon laser, and different laser protocols, other than those established by the ETDRS, for the treatment of PDR. We compared different wavelengths; power and pulse duration; pattern, number and location of burns versus standard argon laser undertaken as specified by the ETDRS. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 5); Ovid MEDLINE; Ovid Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov and the ICTRP. The date of the search was 8 June 2017. We included randomised controlled trials (RCTs) of pan-retinal photocoagulation (PRP) using standard argon laser for treatment of PDR compared with any other laser modality. We excluded studies of lasers that are not in common use, such as the xenon arc, ruby or Krypton laser. We followed Cochrane guidelines and graded the certainty of evidence using the GRADE approach. We identified 11 studies from Europe (6), the USA (2), the Middle East (1) and Asia (2). Five studies compared different types of laser to argon: Nd:YAG (2 studies) or diode (3 studies). Other studies compared modifications to the standard argon laser PRP technique. The studies were poorly reported and we judged all to be at high risk of bias in at least one domain. The sample size varied from 20 to 270 eyes but the majority included 50 participants or fewer.Nd:YAG versus argon laser (2 studies): very low-certainty evidence on vision loss, vision gain, progression and regression of PDR, pain during laser treatment and adverse effects.Diode versus argon laser (3 studies): very-low certainty evidence on vision loss, vision gain, progression and regression of PDR and adverse effects; moderate-certainty evidence that diode laser was more painful (risk ratio (RR) troublesome pain during laser treatment (RR 3.12, 95% CI 2.16 to 4.51; eyes = 202; studies = 3; I 2 = 0%).0.5 second versus 0.1 second exposure (1 study): low-certainty evidence of lower chance of vision loss with 0.5 second compared with 0.1 second exposure but estimates were imprecise and compatible with no difference or an increased chance of vision loss (RR 0.42, 95% CI 0.08 to 2.04, 44 eyes, 1 RCT); low-certainty evidence that people treated with 0.5 second exposure were more likely to gain vision (RR 2.22, 95% CI 0.68 to 7.28, 44 eyes, 1 RCT) but again the estimates were imprecise . People given 0.5 second exposure were more likely to have regression of PDR compared with 0.1 second laser PRP again with imprecise estimate (RR 1.17, 95% CI 0.92 to 1.48, 32 eyes, 1 RCT). There was very low-certainty evidence on progression of PDR and adverse effects.'Light intensity' PRP versus classic PRP (1 study): vision loss or gain was not reported but the mean difference in logMAR acuity at 1 year was -0.09 logMAR (95% CI -0.22 to 0.04, 65 eyes, 1 RCT); and low-certainty evidence that fewer patients had pain during light PRP compared with classic PRP with an imprecise estimate compatible with increased or decreased pain (RR 0.23, 95% CI 0.03 to 1.93, 65 eyes, 1 RCT).'Mild scatter' (laser pattern limited to 400 to 600 laser burns in one sitting) PRP versus standard 'full' scatter PRP (1 study): very low-certainty evidence on vision and visual field loss. No information on adverse effects.'Central' (a more central PRP in addition to mid-peripheral PRP) versus 'peripheral' standard PRP (1 study): low-certainty evidence that people treated with central PRP were more likely to lose 15 or more letters of BCVA compared with peripheral laser PRP (RR 3.00, 95% CI 0.67 to 13.46, 50 eyes, 1 RCT); and less likely to gain 15 or more letters (RR 0.25, 95% CI 0.03 to 2.08) with imprecise estimates compatible with increased or decreased risk.'Centre sparing' PRP (argon laser distribution limited to 3 disc diameters from the upper temporal and lower margin of the fovea) versus standard 'full scatter' PRP (1 study): low-certainty evidence that people treated with 'centre sparing' PRP were less likely to lose 15 or more ETDRS letters of BCVA compared with 'full scatter' PRP (RR 0.67, 95% CI 0.30 to 1.50, 53 eyes). Low-certainty evidence of similar risk of regression of PDR between groups (RR 0.96, 95% CI 0.73 to 1.27, 53 eyes). Adverse events were not reported.'Extended targeted' PRP (to include the equator and any capillary non-perfusion areas between the vascular arcades) versus standard PRP (1 study): low-certainty evidence that people in the extended group had similar or slightly reduced chance of loss of 15 or more letters of BCVA compared with the standard PRP group (RR 0.94, 95% CI 0.70 to 1.28, 270 eyes). Low-certainty evidence that people in the extended group had a similar or slightly increased chance of regression of PDR compared with the standard PRP group (RR 1.11, 95% CI 0.95 to 1.31, 270 eyes). Very low-certainty information on adverse effects. Modern laser techniques and modalities have been developed to treat PDR. However there is limited evidence available with respect to the efficacy and safety of alternative laser systems or strategies compared with the standard argon laser as described in ETDRS.

Chronic wasting disease prion infection of differentiated neurospheres.

PubMed

Iwamaru, Yoshifumi; Mathiason, Candace K; Telling, Glenn C; Hoover, Edward A

2017-07-04

A possible strategy to develop more diverse cell culture systems permissive to infection with naturally occurring prions is to exploit culture of neurospheres from transgenic mice expressing the normal prion protein (PrP) of the native host species. Accordingly, we developed differentiated neurosphere cultures from the cervid PrP-expressing mice to investigate whether this in vitro system would support replication of non-adapted cervid-origin chronic wasting disease (CWD) prions. Here we report the successful amplification of disease-associated PrP in differentiated neurosphere cultures within 3 weeks after exposure to CWD prions from both white-tailed deer or elk. This neurosphere culture system provides a new in vitro tool that can be used to assess non-adapted CWD prion propagation and transmission.

Multiple protein-protein interactions converging on the Prp38 protein during activation of the human spliceosome.

PubMed

Schütze, Tonio; Ulrich, Alexander K C; Apelt, Luise; Will, Cindy L; Bartlick, Natascha; Seeger, Martin; Weber, Gert; Lührmann, Reinhard; Stelzl, Ulrich; Wahl, Markus C

2016-02-01

Spliceosomal Prp38 proteins contain a conserved amino-terminal domain, but only higher eukaryotic orthologs also harbor a carboxy-terminal RS domain, a hallmark of splicing regulatory SR proteins. We show by crystal structure analysis that the amino-terminal domain of human Prp38 is organized around three pairs of antiparallel α-helices and lacks similarities to RNA-binding domains found in canonical SR proteins. Instead, yeast two-hybrid analyses suggest that the amino-terminal domain is a versatile protein-protein interaction hub that possibly binds 12 other spliceosomal proteins, most of which are recruited at the same stage as Prp38. By quantitative, alanine surface-scanning two-hybrid screens and biochemical analyses we delineated four distinct interfaces on the Prp38 amino-terminal domain. In vitro interaction assays using recombinant proteins showed that Prp38 can bind at least two proteins simultaneously via two different interfaces. Addition of excess Prp38 amino-terminal domain to in vitro splicing assays, but not of an interaction-deficient mutant, stalled splicing at a precatalytic stage. Our results show that human Prp38 is an unusual SR protein, whose amino-terminal domain is a multi-interface protein-protein interaction platform that might organize the relative positioning of other proteins during splicing. © 2016 Schütze et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Prion Protein Does Not Confer Resistance to Hippocampus-Derived Zpl Cells against the Toxic Effects of Cu2+, Mn2+, Zn2+ and Co2+ Not Supporting a General Protective Role for PrP in Transition Metal Induced Toxicity

PubMed Central

Cingaram, Pradeep Kumar Reddy; Nyeste, Antal; Dondapati, Divya Teja; Fodor, Elfrieda; Welker, Ervin

2015-01-01

The interactions of transition metals with the prion protein (PrP) are well-documented and characterized, however, there is no consensus on their role in either the physiology of PrP or PrP-related neurodegenerative disorders. PrP has been reported to protect cells from the toxic stimuli of metals. By employing a cell viability assay, we examined the effects of various concentrations of Cu2+, Zn2+, Mn2+, and Co2+ on Zpl (Prnp -/-) and ZW (Prnp +/+) hippocampus-derived mouse neuronal cells. Prnp -/- Zpl cells were more sensitive to all four metals than PrP-expressing Zw cells. However, when we introduced PrP or only the empty vector into Zpl cells, we could not discern any protective effect associated with the presence of PrP. This observation was further corroborated when assessing the toxic effect of metals by propidium-iodide staining and fluorescence activated cell sorting analysis. Thus, our results on this mouse cell culture model do not seem to support a strong protective role for PrP against transition metal toxicity and also emphasize the necessity of extreme care when comparing cells derived from PrP knock-out and wild type mice. PMID:26426582

Pigeonpea Hybrid-Proline-Rich Protein (CcHyPRP) Confers Biotic and Abiotic Stress Tolerance in Transgenic Rice

PubMed Central

Mellacheruvu, Sunitha; Tamirisa, Srinath; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

2016-01-01

In this study, we report the overexpression of Cajanus cajan hybrid-proline-rich protein encoding gene (CcHyPRP) in rice which resulted in increased tolerance to both abiotic and biotic stresses. Compared to the control plants, the transgenic rice lines, expressing CcHyPRP, exhibited high-level tolerance against major abiotic stresses, viz., drought, salinity, and heat, as evidenced by increased biomass, chlorophyll content, survival rate, root, and shoot growth. Further, transgenic rice lines showed increased panicle size and grain number compared to the control plants under different stress conditions. The CcHyPRP transgenics, as compared to the control, revealed enhanced activities of catalase and superoxide dismutase (SOD) enzymes and reduced malondialdehyde (MDA) levels. Expression pattern of CcHyPRP::GFP fusion-protein confirmed its predominant localization in cell walls. Moreover, the CcHyPRP transgenics, as compared to the control, exhibited increased resistance to the fungal pathogen Magnaporthe grisea which causes blast disease in rice. Higher levels of bZIP and endochitinase transcripts as well as endochitinase activity were observed in transgenic rice compared to the control plants. The overall results demonstrate the intrinsic role of CcHyPRP in conferring multiple stress tolerance at the whole-plant level. The multipotent CcHyPRP seems promising as a prime candidate gene to fortify crop plants for enhanced tolerance/resistance to different stress factors. PMID:26834756

Enhanced Sternal Healing via Platelet-Rich Plasma and Biodegradable Gelatin Hydrogel.

PubMed

Shibata, Masafumi; Takagi, Gen; Kudo, Mitsuhiro; Kurita, Jiro; Kawamoto, Yoko; Miyagi, Yasuo; Kanazashi, Mikimoto; Sakatani, Takashi; Naito, Zenya; Tabata, Yasuhiko; Miyamoto, Masaaki; Nitta, Takashi

2018-05-16

Platelet-rich plasma (PRP) contains numerous growth factors and promotes bone fracture healing. The aim of this study was to evaluate the effectiveness of the controlled release of PRP from biodegradable gelatin hydrogel for promoting healing in a rabbit ischemic sternal model. PRP was prepared from the whole blood of a Japanese white rabbit. Sixteen rabbits were randomized into four groups (each n = 4) and all underwent median sternotomy and bilateral internal thoracic artery removal. Before the sternum was closed, the following solutions were applied between the sternum incisions in three of the groups: 30 mg of gelatin hydrogel incorporating 300 μL of phosphate-buffered saline, 300 μL of a solution form of PRP, or 30 mg of gelatin hydrogel incorporating 300 μL of PRP (PRP+Gel). The fourth group acted as a control. Sternal healing was evaluated by histology and micro-computed tomography 7 days after the intervention. The PRP+Gel group showed a significantly higher proportion of fibrosis within the fracture area (an indicator of sternal healing) than the other groups and a significantly higher mean intensity of osteocalcin. These results indicate that the controlled release of PRP from locally applied gelatin hydrogel was markedly effective in enhancing sternal healing in the early postoperative period. This novel therapy could potentially help prevent complications such as deep sternal wound infection and could result in early postoperative ambulation after median sternotomy.

Effect of Bone Marrow Aspirate Concentrate-Platelet-Rich Plasma on Tendon-Derived Stem Cells and Rotator Cuff Tendon Tear.

PubMed

Kim, Sun Jeong; Song, Da Hyun; Park, Jong Wook; Park, Silvia; Kim, Sang Jun

2017-05-09

Bone marrow aspirate concentrates (BMACs) and platelet-rich plasma (PRP) are good sources to control the differentiation of tendon-derived stem cells (TDSCs), but there has been no study about the effect of the BMAC-PRP complex on TDSCs and tendinopathy. The aim of this study was to investigate the effect of BMAC-PRP on the TDSCs and to find the therapeutic effect of BMAC-PRP on the rotator cuff tendon tear. The chondrogenic and osteogenic potential of TDSCs decreased, but the adipogenic potential of TDSCs revealed no significant difference when they were cocultured with BMAC-PRP. Cell proliferation was significantly greater in TDSCs cocultured with BMAC-PRP than in TDSCs. The degree of wound closure (percentage) was different between TDSCs and TDSCs with BMAC-PRP. There was no significant difference in expression of collagen type I and type III in immunocytochemical staining in the presence of BMAC-PRP. Initial visual analog scale (VAS) score was 5.8 ± 1.9, which changed to 5.0 ± 2.3 at 3 weeks and 2.8 ± 2.3 at 3 months after the BMAC-PRP injection (p < 0.01). The American Shoulder Elbow Surgeon score changed from 39.4 ± 13.0 at baseline to 52.9 ± 22.9 at 3 weeks and 71.8 ± 19.7 at 3 months after the injection (p < 0.01). The initial torn area of the rotator cuff tendon was 30.2 ± 24.5 mm2, and this area was reduced to 22.5 ± 18.9 mm2 at 3 months, but the change was not significant (p > 0.05). The data indicate that BMAC-PRP enhances the proliferation and migration of TDSCs and prevents the aberrant chondrogenic and osteogenic differentiation of TDSCs, which might provide a mechanistic basis for the therapeutic benefits of BMAC-PRP for rotator cuff tendon tear.

Platelet-rich plasma for arthroscopic repair of large to massive rotator cuff tears: a randomized, single-blind, parallel-group trial.

PubMed

Jo, Chris Hyunchul; Shin, Ji Sun; Lee, Young Gil; Shin, Won Hyoung; Kim, Hyang; Lee, Seung Yeon; Yoon, Kang Sup; Shin, Sue

2013-10-01

Platelet-rich plasma (PRP) is expected to have a biological augmentation potential in the healing of various diseases and injuries, including rotator cuff tears. However, few evaluations have been performed specifically for large to massive tears. To assess the efficacy of PRP augmentation in patients undergoing arthroscopic repair for large to massive rotator cuff tears. Randomized controlled trial; Level of evidence, 1. A total of 48 patients scheduled for arthroscopic repair of large to massive rotator cuff tears were randomly assigned to receive either PRP-augmented (PRP group) or conventional treatment (conventional group). In the PRP group, 3 PRP gels (3 × 3 mL) were applied to each patient between the torn end and the greater tuberosity. The primary outcome measure was the retear rate assessed by magnetic resonance imaging (MRI) or computed tomographic arthrography (CTA) at a minimum of 9 months after surgery. Secondary outcome measures included pain, range of motion, muscle strength, overall satisfaction, functional scores, and the change in cross-sectional area (CSA) of the supraspinatus. The retear rate of the PRP group (20.0%) was significantly lower than that of the conventional group (55.6%) (P = .023). Clinical outcomes showed no statistical difference between the 2 groups (all P > .05) except for the overall function (P = .043). The change in 1-year postoperative and immediately postoperative CSA was significantly different between the 2 groups: -15.54 ± 94.34 mm² in the PRP group versus -85.62 ± 103.57 mm² in the conventional group (P = .047). The application of PRP for large to massive rotator cuff repairs significantly improved structural outcomes, as evidenced by a decreased retear rate and increased CSA of the supraspinatus compared with repairs without PRP augmentation. While there was no significant difference in clinical outcomes except the overall shoulder function after 1-year follow-up, better structural outcomes in the PRP group might suggest improved clinical outcomes at longer term follow-up.

The Biomechanical and Histologic Effects of Platelet-Rich Plasma on Rat Rotator Cuff Repairs

PubMed Central

Beck, Jennifer; Evans, Douglas; Tonino, Pietro M.; Yong, Sherri; Callaci, John J.

2013-01-01

Background Rotator cuff tears are common injuries that are often treated with surgical repair. Because of the high concentration of growth factors within platelets, platelet-rich plasma (PRP) has the potential to enhance healing in rotator cuff repairs. Hypothesis Platelet-rich plasma would alter the biomechanical and histologic properties of rotator cuff repair during an acute injury response. Study Design Controlled laboratory study. Methods Platelet-rich plasma was produced from inbred donor rats. A tendon-from-bone supraspinatus tear was created surgically and an immediate transosseous repair performed. The control group underwent repair only. The PRP group underwent a repair with PRP augmentation. Rats in each group were sacrificed at 7, 14, and 21 days. The surgically repaired tendons underwent biomechanical testing, including failure load, stiffness, failure strain, and stress relaxation characteristics. Histological analysis evaluated the cellular characteristics of the repair tissue. Results At 7- and 21-day periods, augmentation with PRP showed statistically significant effects on the biomechanical properties of the repaired rat supraspinatus tear, but failure load was not increased at the 7-, 14-, or 21-day periods (P = .688, .209, and .477, respectively). The control group had significantly higher stiffness at 21 days (P = .006). The control group had higher failure strain at 7 days (P = .02), whereas the PRP group had higher failure strain at 21 days (P = .008). Histologically, the PRP group showed increased fibroblastic response and vascular proliferation at each time point. At 21 days, the collagen fibers in the PRP group were oriented in a more linear fashion toward the tendon footprint. Conclusion In this controlled, rat model study, PRP altered the tissue properties of the supraspinatus tendon without affecting the construct’s failure load. Clinical Relevance The decreased tendon tissue stiffness acutely and failure to enhance tendon-to-bone healing of repairs should be considered before augmenting rotator cuff repairs with PRP. Further studies will be necessary to determine the role of PRP in clinical practice. PMID:22822177

Platelet-Rich Plasma Versus Tretinoin in Treatment of Striae Distensae: A Comparative Study.

PubMed

Gamil, Hend D; Ibrahim, Samia A; Ebrahim, Howyda M; Albalat, Waleed

2018-05-01

Striae distensae (SD) are dermal scars associated with atrophy of the epidermis. To evaluate the effect and safety of intralesional injection of platelet-rich plasma (PRP) versus topical tretinoin 0.05% in treatment of SD. Thirty patients (27 females and 3 males) had bilateral striae distensae were enrolled in this study. In every patient, half of the selected striae were treated with PRP intralesional injection. The other half was treated by topical tretinoin. Skin biopsies were taken from both sides before and after the treatment. Digital photographs were taken at the baseline and at the end of follow-up period. Clinical improvement was evaluated by 2 blind dermatologists in addition to the patient's satisfaction rating. There was statistically significant improvement in the SD treated with PRP and topical tretinoin cream. The improvement was more in the SD treated with PRP injections (p = .015). Patient's satisfaction showed that the improvement was more in the PRP-treated side (p = .003). Collagen and elastic fibers in the dermis were increased in all biopsies after treatment. PRP injection and topical tretinoin are safe for the treatment of SD, but PRP is more effective and it gives better therapeutic response than tretinoin.

The use of platelet-rich plasma to treat chronic tendinopathies: A technical analysis.

PubMed

Kaux, Jean-François; Emonds-Alt, Thibault

2018-05-01

Platelet-rich plasma (PRP) is blood plasma with a high concentration of autologous platelets which constitute an immense reservoir of growth factors. The clinical use of PRP is widespread in various medical applications. Although highly popular with athletes, the use of PRP for the treatment of tendinopathies remains scientifically controversial, particularly due to the diversity of products that go by the name of "PRP." To optimize its use, it is important to look at the various stages of obtaining PRP. In this literature review, we take a closer look at eight parameters which may influence the quality of PRP: 1) anticoagulants used to preserve the best platelet function, 2) the speed of centrifugation used to extract the platelets, 3) the platelet concentrations obtained, 4) the impact of the concentration of red and while blood cells on PRP actions, 5) platelet activators encouraging platelet degranulation and, hence, the release of growth factors, and 6) the use or nonuse of local anesthetics when carrying out infiltration. In addition to these parameters, it may be interesting to analyze other variables such as 7) the use of ultrasound guidance during the injection with a view to determining the influence they have on potential recovery.

PRP For the Treatment of Cartilage Pathology

PubMed Central

Kon, Elizaveta; Filardo, Giuseppe; Di Matteo, Berardo; Marcacci, Maurilio

2013-01-01

In recent years biological strategies are being more widely used to treat cartilage lesions. One of the most exploited novel treatments is Platelet-rich Plasma (PRP), whose high content of growth factors is supposed to determine a regenerative stimulus to cartilaginous tissue. Despite many promising in vitro and in vivo studies, when discussing clinical application a clear indication for the use of PRP cannot be assessed. There are initial encouraging clinical data, but only a few randomized controlled trials have been published, so it is not possible to fully endorse this kind of approach for the treatment of cartilage pathology. Furthermore, study comparison is very difficult due to the great variability in PRP preparation methods, cell content and concentration, storage modalities, activation methods and even application protocols. These factors partially explain the lack of high quality controlled trials up to now. This paper discusses the main aspects concerning the basic biology of PRP, the principal sources of variability, and summarizes the available literature on PRP use, both in surgical and conservative treatments. Based on current evidence, PRP treatment should only be indicated for low-grade cartilage degeneration and in case of failure of more traditional conservative approaches. PMID:23730375

PubMed

Walder, P; Paša, L; Pavliska, L

2017-01-01

PURPOSE OF THE STUDY The aim of the study was to evaluate the safety and efficacy of the application of platelet- and leukocyte-rich plasma (L-PRP) in the treatment of lateral humeral epicondyle (ERH) as compared to the administration of corticosteroid therapy. MATERIAL AND METHODS It was a prospective, double-blind and randomized clinical trial. It included a total of 25 cases of ERH in 23 patients aged 18 to 60 years. They were divided into two arms: L-PRP arm with 10 cases and corticosteroid arm with 15 cases. The therapy of L-PRP group: first application: 3 ml of native L-PRP without activation, second application: after 6 weeks, 3 ml of thawed L-PRP. Therapy of the corticosteroid arm patients: first and second application (both after 6 weeks) of 3.5 mg of Betamethasonum. The follow-up period was 12 months. The safety evaluation was carried out based on the number of adverse events. The efficacy was evaluated using the DASH score and the Visual Analogue Scale (VAS). The time series outcomes were analysed statistically by percentile graphs and repeated measures ANOVA. RESULTS The ascertained values of blood elements in the received L-PRP as against the original blood were the following: platelets around 400%, white blood cells around 200%, red blood cells around 30%. The differences in individual subpopulations of white blood cells: neutrophils 74%, lymphocytes 424%, monocytes 385%, eosinophils 43%, basophils 337%. The product was classified as L-PRP group based on the POSEIDO classification. Safety evaluation: both the groups reported no adverse and also no serious adverse events. One patient withdrew from the corticosteroid group on the grounds of a subjective feeling of treatment failure. Efficacy evaluation: for both the general DASH score and Work Module a statistically better effect of L-PRP was proven in the first 6 months at p < 0.05. For the general DASH score, the L-PRP group reported a decrease of difficulties from approximately 50% to 20% on DASH score and in the corticosteroid group the difficulties returned to more or less the initial value. In the Work Module, the L-PRP group showed a decline in difficulties from approximately 46% to 18% and the corticosteroid group from approximately 43% only to 38%. The Sports and Music Module was evaluated by percentile graphs only. The VAS assessment proved that an effect was achieved only after the administration of the first dose of L-PRP and corticosteroid, with a more significant effect reported in L-PRP. The overall statistical evaluation using the VAS showed no difference between these two therapies at the level of significance of p<0.05 (p = 0.08). DISCUSSION The product used by us was classified as a L-PRP subcategory. The application of the native and subsequently frozen L-PRP is rare as compared to the corticosteroid therapy. CONCLUSIONS According to our results, the application of L-PRP is suitable to treat lateral humeral epicondyle. The benefits can be foreseen in the form of a better functional score, whereas the analgesic effect equals the effect of corticosteroid. A slightly additive effect was seen in the thawed second dose. Key words: platelet- and leucocyte-rich plasma, epicondylitis radialis humeri.

Use of autologous platelet rich plasma to treat gingival recession in esthetic periodontal surgery

PubMed Central

Naik, Archana R.; Ramesh, Alampalli V.; Dwarkanath, C. D.; Naik, Madhukeshwara S.; Chinnappa, A. B.

2013-01-01

Background: Multiple approaches have been used to replace lost, damaged or diseased gingival tissues. Coronally advanced flap (CAF) and the use of guided tissue regeneration are among the successfully used surgical techniques to treat gingival recession. Platelet rich plasma (PRP), containing autologous growth factors, has been shown to promote soft-tissue healing. Therefore, the purpose of this study was to evaluate the efficacy of PRP in combination with CAF in the treatment of gingival recession. Materials and Methods: A total of 15 systemically healthy patients with buccal Miller's class I and class II gingival recession in cuspids or premolars participated in the study. CAF procedure was performed and PRP with collagen sponge was placed over the defect. Clinical parameters such as recession depth, recession width, surface area, width of keratinized gingival (KG), clinical attachment level (CAL), probing depth, plaque index and gingival index were evaluated at 3, 6 and 9 months post-surgery. The percentage of root coverage was calculated. Results: The results of this study suggest that the CAF procedure provides a predictable and simple technique in the treatment of localized Class I and Class II gingival recession. The additional application of PRP does significantly increase the width of KG and gain in clinical attachment. Conclusion: CAF procedure is a predictable and simple technique in the treatment of gingival recession and the additional application of PRP does significantly increase the width of KG and gain in CAL. The long-term benefits following surgical treatment of such defects needs to be determined further. PMID:24049336

Effect of PR interval prolongation on long-term outcomes in patients with left bundle branch block vs non-left bundle branch block morphologies undergoing cardiac resynchronization therapy.

PubMed

Rickard, John; Karim, Mohammad; Baranowski, Bryan; Cantillon, Daniel; Spragg, David; Tang, W H Wilson; Niebauer, Mark; Grimm, Richard; Trulock, Kevin; Wilkoff, Bruce; Varma, Niraj

2017-10-01

Although the influence of QRS duration (QRSd) and/or bundle branch block morphology on outcomes of cardiac resynchronization therapy (CRT) have been well studied, the effect of PR interval remains uncertain. The purpose of this study was to evaluate the impact of PR prolongation (PRp) before CRT on long-term outcomes, specifically taking into account bundle branch block morphology and QRSd. We extracted clinical data on consecutive patients undergoing CRT. Multivariate models were constructed to analyze the effect of PRp (≥200 ms) on the combined endpoint of death, heart transplant, or left ventricular assist device. Kaplan-Meier curves were constructed stratifying patients based on bundle branch block and QRSd (dichotomized by 150 ms). Of the 472 patients who met inclusion criteria, 197 (41.7%) had PR interval ≥200 ms. During follow-up (mean 5.1 ± 2.6 years) there were 214 endpoints, of which 109 (23.1%) occurred in patients with PRp. In multivariate analysis, PRp was independently associated with worsened outcomes (hazard ratio 1.34, 95% confidence interval 1.01-1.77, P = .04). When stratified by bundle branch block morphology, PRp was significantly associated with worsened outcomes (log-rank P <.001) in patients with LBBB but not in those with non-LBBB (log-rank P = .55). Among patients with LBBB, stratified by QRSd, patients without PRp had improved outcomes compared to those with PRp independent of QRSd (log-rank P <.001). PRp is an independent predictor of impaired long-term outcome after CRT among patients with LBBB but not in non-LBBB patients. Notably, among LBBB patients, PRp is a more important predictor than QRSd in assessing long-term outcomes. Copyright © 2017. Published by Elsevier Inc.

Combination of platelet rich plasma in fractional carbon dioxide laser treatment increased clinical efficacy of for acne scar by enhancement of collagen production and modulation of laser-induced inflammation.

PubMed

Min, Seonguk; Yoon, Ji Young; Park, Seon Yong; Moon, Jungyoon; Kwon, Hyuck Hoon; Suh, Dae Hun

2018-04-01

Platelet-rich plasma (PRP) which contains large amounts of growth factors has been tried to enhance therapeutic efficacy of laser treatment for acne scar with unknown underlying mechanism. The present study was conducted to investigate the molecular mechanism of increased clinical efficacy of PRP when combined with fractional laser treatment for treating acne scars. Subjects with mild to moderate acne scars were treated with two sessions of fractional CO 2 laser therapy given with and without co-administration of PRP. Skin biopsy specimens were obtained at baseline, 1, 3, 7, and 28 days for investigation of molecular profiles associated with skin changes produced by laser plus PRP treatment. The PRP treatment increased clinical efficacy with decreased severity of adverse effects such as erythema, swelling and oozing. Productions of TGFβ1 and TGFβ3 proteins were more highly elevated on the PRP-treated side of the face compared to the control side at day 28. Furthermore, PRP-treated side showed significant increase of c-myc, TIMP, and HGF expression. Experimental fibroblast culture model was also used. PRP administration after laser irradiation increased expressions of p-Akt, TGFβ1, TGFβ3, β-catenin, collagen 1, and collagen 3 in both dose-dependent and time dependent manners in fibroblast. Moreover, we acquired clinical and histological data through randomized control clinical trial. Taken together with human study results combined with the data from cell experiments we suggest that PRP treatment increased fibrogenetic molecules induced by fractional CO 2 laser, which have association with clinical effect. Lasers Surg. Med. 50:302-310, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Overexpression of PLK3 Mediates the Degradation of Abnormal Prion Proteins Dependent on Chaperone-Mediated Autophagy.

PubMed

Wang, Hui; Tian, Chan; Sun, Jing; Chen, Li-Na; Lv, Yan; Yang, Xiao-Dong; Xiao, Kang; Wang, Jing; Chen, Cao; Shi, Qi; Shao, Qi-Xiang; Dong, Xiao-Ping

2017-08-01

Polo-like kinase 3 (PLK3) is the main cause of cell cycle reentry-related neuronal apoptosis which has been implicated in the pathogenesis of prion diseases. Previous work also showed the regulatory activity of exogenous PLK3 on the degradation of PrP (prion protein) mutants and pathogenic PrP Sc ; however, the precise mechanisms remain unknown. In this study, we identified that the overexpression of PLK3-mediated degradation of PrP mutant and PrP Sc was repressed by lysosome rather than by proteasomal and macroautophagy inhibitors. Core components of chaperone-mediated autophagy (CMA) effectors, lysosome-associated membrane protein type 2A (LAMP2a), and heat shock cognate protein 70 (Hsc70) are markedly decreased in the HEK293T cells expressing PrP mutant and scrapie-infected cell line SMB-S15. Meanwhile, PrP mutant showed ability to interact with LAMP2a and Hsc70. Overexpression of PLK3 sufficiently increased the cellular levels of LAMP2a and Hsc70, accompanying with declining the accumulations of PrP mutant and PrP Sc . The kinase domain (KD) of PLK3 was responsible for elevating LAMP2a and Hsc70. Knockdown of endogenous PLK3 enhanced the activity of macroautophagy in the cultured cells. Moreover, time-dependent reductions of LAMP2a and Hsc70 were also observed in the brain tissues of hamster-adapted scrapie agent 263K-infected hamsters, indicating an impairment of CMA during prion infection. Those data indicate that the overexpression of PLK3-mediated degradation of abnormal PrP is largely dependent on CMA pathway.

The role of PRP and adipose tissue-derived keratinocytes on burn wound healing in diabetic rats

PubMed Central

Hosseini Mansoub, Navid; Gürdal, Mehmet; Karadadaş, Elif; Kabadayi, Hilal; Vatansever, Seda; Ercan, Gulinnaz

2018-01-01

Introduction: Diabetic burn wounds and ulcers are significant complications of diabetic patients. The aim of this study is to investigate the use of platelet rich-plasma (PRP) and/or keratinocyte-like cells (KLCs) in diabetic thermal wound rat model and to evaluate EGF, FGF-2, TGF-β1, COL1α2, MCP-1 and VEGF-α as wound healing markers at gene expression level. Method: In this study, we used adipose tissue as the source of mesenchymal stem cells (MSCs) and differentiated MSCs into KLCs. KLCs were characterized and transferred to the burn areas on the dorsum of streptozotocine (STZ)-induced diabetic rats. We prepared PRP from rat blood and evaluated its effect alone or in combination with KLCs. On 3rd, 7th, 10th and 14th days after treatment, wound areas were measured and biopsy samples were excised from the wound areas of the KLCs and/or PRP-treated and untreated diabetic rats to analyze gene expression levels of wound healing markers by qPCR. Results: We observed that, wound contraction started earlier in the PRP and/or KLCs-treated groups in comparison to the control group. However, PRP and KLCs when applied in combination showed additive affect in wound healing. In all groups treated with KLCs and/or PRP, the gene expression levels of evaluated growth factors and COL1α2 increased, while MCP-1 levels decreased when compared to the untreated diabetic rats. In addition, the most prominent difference in qPCR results belongs to combined PRP and KLCs-treated group. Conclusion: We demonstrated that applying PRP and KLCs in combination has a greater potential for treatment of diabetic burn wounds. PMID:29713597

Comparative evaluation of platelet-rich plasma and guided tissue regeneration membrane in the healing of apicomarginal defects: a clinical study.

PubMed

Goyal, Bhawna; Tewari, Sanjay; Duhan, Jigyasa; Sehgal, P K

2011-06-01

The aim of the study was to compare the healing responses of platelet-rich plasma (PRP), PRP + a collagen sponge, and a collagen membrane used as guided tissue regeneration (GTR) materials for the treatment of apicomarginal defects. Thirty patients with suppurative chronic apical periodontitis and apicomarginal communication were selected and allocated randomly into three groups according to the barrier technique to be used during periradicular surgery: the collagen membrane group, the PRP group, and the PRP + collagen sponge group. Clinical and radiographic measurements were determined at baseline and every 3 months after surgery up to 1 year. Cases were defined as healed when no clinical signs or symptoms were present, and radiographs showed complete or incomplete (scar tissue) healing of previous radiolucencies. The PRP and PRP + collagen sponge groups depicted 83.33% and 88.89% healing, respectively, in terms of combined clinical-radiographic healing as compared with 80% in the collagen membrane group. All the three treatments showed highly significant (P < .05) reductions in the periodontal pocket depth (PD), the clinical attachment level (CAL), the gingival margin position (GMP), the size of the periapical lesion, the percentage reduction of the periapical rarefactions, and periapical healing. No significant differences between the three groups were evident for these parameters (P > .05). GTR applied to apicomarginal defects using PRP or PRP + collagen sponge lead to similar enhancements of the clinical outcome of periradicular surgery in terms of periapical healing, gain of periodontal support, PD reduction, and PRP may be an alternative treatment for GTR membrane in the treatment of apicomarginal defects. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Platelet-rich plasma enhances the integration of bioengineered cartilage with native tissue in an in vitro model.

PubMed

Sermer, Corey; Kandel, Rita; Anderson, Jesse; Hurtig, Mark; Theodoropoulos, John

2018-02-01

Current therapies for cartilage repair can be limited by an inability of the repair tissue to integrate with host tissue. Thus, there is interest in developing approaches to enhance integration. We have previously shown that platelet-rich plasma (PRP) improves cartilage tissue formation. This raised the question as to whether PRP could promote cartilage integration. Chondrocytes were isolated from cartilage harvested from bovine joints, seeded on a porous bone substitute and grown in vitro to form an osteochondral-like implant. After 7 days, the biphasic construct was soaked in PRP for 30 min before implantation into the core of a donut-shaped biphasic explant of native cartilage and bone. Controls were not soaked in PRP. The implant-explant construct was cultured for 2-4 weeks. PRP-soaked bioengineered implants integrated with host tissue in 73% of samples, whereas controls only integrated in 19% of samples. The integration strength, as determined by a push-out test, was significantly increased in the PRP-soaked implant group (219 ± 35.4 kPa) compared with controls (72.0 ± 28.5 kPa). This correlated with an increase in glycosaminoglycan and collagen accumulation in the region of integration in the PRP-treated implant group, compared with untreated controls. Immunohistochemical studies revealed that the integration zone contained collagen type II and aggrecan. The cells at the zone of integration in the PRP-soaked group had a 3.5-fold increase in matrix metalloproteinase-13 gene expression compared with controls. These results suggest that PRP-soaked bioengineered cartilage implants may be a better approach for cartilage repair due to enhanced integration. Copyright © 2017 John Wiley & Sons, Ltd.

The application of PRP combined with TCP in repairing avascular necrosis of the femoral head after femoral neck fracture in rabbit.

PubMed

Zhang, X-L; Wang, Y-M; Chu, K; Wang, Z-H; Liu, Y-H; Jiang, L-H; Chen, X; Zhou, Z-Y; Yin, G

2018-02-01

In view of the high occurrence of avascular necrosis of the femoral head (ANFH) after femoral neck fracture and the difficulties in the treatment, our work aimed to explore the effects of platelet-rich plasma (PRP) combined with tri-calcium phosphate (TCP) on the repair of ANFH after femoral neck fracture and to provide reference for clinical treatment. Thirty New Zealand white rabbits were randomly divided into control group, TCP group, and PRP+TCP group. The rabbit ANFH model was established and femoral head tissues were collected. HE staining was used for histological observation. Image analysis and statistical analysis were used to calculate the New Bone Area fraction (NBA %). The levels of bone morphogenetic protein (BMP)-7, transforming growth factor (TGF)-β1, basic fibroblast growth factor (bFGF), interleukin (IL)-6 and tumor necrosis factor (TNF)-a in serum were detected by Enzyme-Linked ImmunoSorbent Assay (ELISA). The new bone area of TCP group was significantly lower than that of PRP+TCP group (p<0.05). Compared with the control group, the levels of BMP-7, TGF-β1 and bFGF were significantly increased in both TCP and PRP+TCP groups (p<0.05), and the increase in PRP+TCP group was higher than that in TCP group. TCP and PRP+TCP can both significantly reduce the content of IL-6 and TNF-a (p<0.05); however, higher decrease was found in PRP+TCP group compared with the TCP group at 8 weeks after injection. PRP combined with TCP, which can promote new bone formation and inhibit inflammatory response, showed higher efficiency in repairing ANFH than internal fixation alone.

Evaluation of the Effects of Platelet-Rich Plasma (PRP) Therapy Involved in the Healing of Sports-Related Soft Tissue Injuries

PubMed Central

Middleton, Kellie K.; Barro, Victor; Muller, Bart; Terada, Satosha; Fu, Freddie H.

2012-01-01

Abstract Musculoskeletal injuries are the most common cause of severe long-term pain and physical disability, and affect hundreds of millions of people around the world. One of the most popular methods used to biologically enhance healing in the fields of orthopaedic surgery and sports medicine includes the use of autologous blood products, namely, platelet rich plasma (PRP). PRP is an autologous concentration of human platelets to supra-physiologic levels. At baseline levels, platelets function as a natural reservoir for growth factors including platelet-derived growth factor (PDGF), epidermal growth factor (EGF), transforming growth factor-beta 1 (TGF-β1), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (FGF), hepatocyte growth factor (HGF), and insulin-like growth factor (IGF-I). PRP is commonly used in orthopaedic practice to augment healing in sports-related injuries of skeletal muscle, tendons, and ligaments. Despite its pervasive use, the clinical efficacy of PrP therapy and varying mechanisms of action have yet to be established. Basic science research has revealed that PRP exerts is effects through many downstream events secondary to release of growth factors and other bioactive factors from its alpha granules. These effects may vary depending on the location of injury and the concentration of important growth factors involved in various soft tissue healing responses. This review focuses on the effects of PrP and its associated bioactive factors as elucidated in basic science research. Current findings in PRP basic science research, which have shed light on its proposed mechanisms of action, have opened doors for future areas of PrP research. PMID:23576936

Effects of platelet rich plasma and chondrocyte co-culture on MSC chondrogenesis, hypertrophy and pathological responses

PubMed Central

Ramezanifard, Rouhallah; Kabiri, Mahboubeh; Hanaee Ahvaz, Hana

2017-01-01

Regarding the inadequate healing capability of cartilage tissue, cell-based therapy is making the future of cartilage repair and regeneration. Mesenchymal stem cells (MSC) have shown great promise in cartilage regeneration. However, a yet-unresolved issue is the emergence of hypertrophic and pathologic markers during in vitro MSC chondrogenesis. Articular chondrocytes (AC) can suppress the undesired hypertrophy when co-cultured with MSC. On the other hand, platelet rich plasma (PRP), is considered potentially effective for cartilage repair and in-vitro chondrogenesis. We thus aimed to harness chondro-promotive effects of PRP and hypertrophic-suppressive effects of AC:MSC co-culture to achieve a more functional cartilage neo-tissue. We used PRP or conventional-differentiation chondrogenic media (ConvDiff) in MSC mono-cultures and AC:MSC co-cultures. We assessed gene expression of chondrogenic and hypertrophic markers using real-time RT-PCR and immunostaining. Alkaline-phosphatase activity (ALP) and calcium content of the pellets were quantified. We also measured VEGF and TNF-α secretion via ELISA. We showed PRP had higher chondrogenic potential (in mRNA and protein level) and hypertrophic-suppressive effects than Conv-Diff (mRNA level). Co-culturing reduced ALP while PRP increased calcium deposition. In all four groups, TNF-α was down-regulated compared to MSC controls, with co-cultures receiving ConvDiff media secreting the least. Meanwhile, the only group with increased VEGF secretion was PRP-mono-cultures. We observed synergistic effects for PRP and AC:MSC co-culture in enhancing chondrogenesis. Inclusion of AC reduced hypertrophic markers and angiogenic potential in PRP groups. We thus propose that combination of PRP and co-culture would favor chondrogenesis while alleviate but not totally eradicate undesired hypertrophic and pathologic responses. PMID:28900383

Progression through the spliceosome cycle requires Prp38p function for U4/U6 snRNA dissociation.

PubMed Central

Xie, J; Beickman, K; Otte, E; Rymond, B C

1998-01-01

The elaborate and energy-intensive spliceosome assembly pathway belies the seemingly simple chemistry of pre-mRNA splicing. Prp38p was previously identified as a protein required in vivo and in vitro for the first pre-mRNA cleavage reaction catalyzed by the spliceosome. Here we show that Prp38p is a unique component of the U4/U6.U5 tri-small nuclear ribonucleoprotein (snRNP) particle and is necessary for an essential step late in spliceosome maturation. Without Prp38p activity spliceosomes form, but arrest in a catalytically impaired state. Functional spliceosomes shed U4 snRNA before 5' splice-site cleavage. In contrast, Prp38p-defective spliceosomes retain U4 snRNA bound to its U6 snRNA base-pairing partner. Prp38p is the first tri-snRNP-specific protein shown to be dispensable for assembly, but required for conformational changes which lead to catalytic activation of the spliceosome. PMID:9582287

Ex vivo mammalian prions are formed of paired double helical prion protein fibrils.

PubMed

Terry, Cassandra; Wenborn, Adam; Gros, Nathalie; Sells, Jessica; Joiner, Susan; Hosszu, Laszlo L P; Tattum, M Howard; Panico, Silvia; Clare, Daniel K; Collinge, John; Saibil, Helen R; Wadsworth, Jonathan D F

2016-05-01

Mammalian prions are hypothesized to be fibrillar or amyloid forms of prion protein (PrP), but structures observed to date have not been definitively correlated with infectivity and the three-dimensional structure of infectious prions has remained obscure. Recently, we developed novel methods to obtain exceptionally pure preparations of prions from mouse brain and showed that pathogenic PrP in these high-titre preparations is assembled into rod-like assemblies. Here, we have used precise cell culture-based prion infectivity assays to define the physical relationship between the PrP rods and prion infectivity and have used electron tomography to define their architecture. We show that infectious PrP rods isolated from multiple prion strains have a common hierarchical assembly comprising twisted pairs of short fibres with repeating substructure. The architecture of the PrP rods provides a new structural basis for understanding prion infectivity and can explain the inability to systematically generate high-titre synthetic prions from recombinant PrP. © 2016 The Authors.

Cellular mechanisms responsible for cell-to-cell spreading of prions.

PubMed

Vilette, Didier; Courte, Josquin; Peyrin, Jean Michel; Coudert, Laurent; Schaeffer, Laurent; Andréoletti, Olivier; Leblanc, Pascal

2018-05-14

Prions are infectious agents that cause fatal neurodegenerative diseases. Current evidence indicates that they are essentially composed of an abnormally folded protein (PrP Sc ). These abnormal aggregated PrP Sc species multiply in infected cells by recruiting and converting the host PrP C protein into new PrP Sc . How prions move from cell to cell and progressively spread across the infected tissue is of crucial importance and may provide experimental opportunity to delay the progression of the disease. In infected cells, different mechanisms have been identified, including release of infectious extracellular vesicles and intercellular transfer of PrP Sc -containing organelles through tunneling nanotubes. These findings should allow manipulation of the intracellular trafficking events targeting PrP Sc in these particular subcellular compartments to experimentally address the relative contribution of these mechanisms to in vivo prion pathogenesis. In addition, such information may prompt further experimental strategies to decipher the causal roles of protein misfolding and aggregation in other human neurodegenerative diseases.

Analysis of yeast prp20 mutations and functional complementation by the human homologue RCC1, a protein involved in the control of chromosome condensation.

PubMed

Fleischmann, M; Clark, M W; Forrester, W; Wickens, M; Nishimoto, T; Aebi, M

1991-07-01

Mutations in the PRP20 gene of yeast show a pleiotropic phenotype, in which both mRNA metabolism and nuclear structure are affected. srm1 mutants, defective in the same gene, influence the signal transduction pathway for the pheromone response. The yeast PRP20/SRM1 protein is highly homologous to the RCC1 protein of man, hamster and frog. In mammalian cells, this protein is a negative regulator for initiation of chromosome condensation. We report the analysis of two, independently isolated, recessive temperature-sensitive prp20 mutants. They have identical G to A transitions, leading to the alteration of a highly conserved glycine residue to glutamic acid. By immunofluorescence microscopy the PRP20 protein was localized in the nucleus. Expression of the RCC1 protein can complement the temperature-sensitive phenotype of prp20 mutants, demonstrating the functional similarity of the yeast and mammalian proteins.

Platelet rich plasma promotes skeletal muscle cell migration in association with up-regulation of FAK, paxillin, and F-Actin formation.

PubMed

Tsai, Wen-Chung; Yu, Tung-Yang; Lin, Li-Ping; Lin, Mioa-Sui; Tsai, Ting-Ta; Pang, Jong-Hwei S

2017-11-01

Platelet rich plasma (PRP) contains various cytokines and growth factors which may be beneficial to the healing process of injured muscle. The aim of this study was to investigate the effect and molecular mechanism of PRP on migration of skeletal muscle cells. Skeletal muscle cells intrinsic to Sprague-Dawley rats were treated with PRP. The cell migration was evaluated by transwell filter migration assay and electric cell-substrate impedance sensing. The spreading of cells was evaluated microscopically. The formation of filamentous actin (F-actin) cytoskeleton was assessed by immunofluorescence staining. The protein expressions of paxillin and focal adhesion kinase (FAK) were assessed by Western blot analysis. Transfection of paxillin small-interfering RNA (siRNAs) to muscle cells was performed to validate the role of paxillin in PRP-mediated promotion of cell migration. Dose-dependently PRP promotes migration of and spreading and muscle cells. Protein expressions of paxillin and FAK were up-regulated dose-dependently. F-actin formation was also enhanced by PRP treatment. Furthermore, the knockdown of paxillin expression impaired the effect of PRP to promote cell migration. It was concluded that PRP promoting migration of muscle cells is associated with up-regulation of proteins expression of paxillin and FAK as well as increasing F-actin formation. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2506-2512, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Biologic response of human anterior cruciate ligamentocytes on collagen-patches to platelet-rich plasma formulations with and without leucocytes.

PubMed

Krismer, Anna M; Cabra, Romina S; May, Rahel D; Frauchiger, Daniela A; Kohl, Sandro; Ahmad, Sufian S; Gantenbein, Benjamin

2017-12-01

Due to the poor self-healing capacities of the anterior cruciate ligament, previous primary repair attempts have failed. To enhance biologic healing, platelet rich plasma and collagen scaffold have shown promise in animal models. Platelet rich plasma (PRP) is already used in several clinical applications although outcomes are quite debated. The purpose of this study was to examine the effects of different PRP formulations during 21 days: With leucocytes and pure PRP on human anterior cruciate ligament-derived ligamentocytes grown on collagen patches in 3D cell cultures in vitro. Three experimental groups were formed: 2.5% leucocyte rich PRP, 2.5% pure PRP, 20% leucocyte rich PRP, a negative control, and a positive control. Cell proliferation, cell phenotype on mRNA transcript level, and extracellular matrix production (total collagen and glycosaminoglycan content) were evaluated. DNA content and metabolic cell activity increased significantly in all groups on day 21 compared to day 7, except in the negative control. No changes in extracellular matrix production were detected. Different catabolic genes were induced depending on the concentration of leucocyte rich PRP. PRP with and without leucocytes treated anterior cruciate ligamentocytes significantly increased cell proliferation but not extracellular matrix production. However, the specific activation of different catabolic genes was dependent on the relative content of leucocytes. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2733-2739, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Evaluation of a group cognitive-behavioral depression prevention program for young adolescents: a randomized effectiveness trial.

PubMed

Gillham, Jane E; Reivich, Karen J; Brunwasser, Steven M; Freres, Derek R; Chajon, Norma D; Kash-Macdonald, V Megan; Chaplin, Tara M; Abenavoli, Rachel M; Matlin, Samantha L; Gallop, Robert J; Seligman, Martin E P

2012-01-01

Depression is a common psychological problem in adolescence. Recent research suggests that group cognitive-behavioral interventions can reduce and prevent symptoms of depression in youth. Few studies have tested the effectiveness of such interventions when delivered by school teachers and counselors (as opposed to research team staff). We evaluated the effectiveness of the Penn Resiliency Program for adolescents (PRP-A), a school-based group intervention that targets cognitive behavioral risk factors for depression. We randomly assigned 408 middle school students (ages 10-15) to one of three conditions: PRP-A, PRP-AP (in which adolescents participated in PRP-A and parents were invited to attend a parent intervention component), or a school-as-usual control. Adolescents completed measures of depression and anxiety symptoms, cognitive style, and coping at baseline, immediately after the intervention, and at 6-month follow-up. PRP-A reduced depression symptoms relative to the school as usual control. Baseline levels of hopelessness moderated intervention effects. Among participants with average and high levels of hopelessness, PRP (A and AP) significantly improved depression symptoms, anxiety symptoms, hopelessness, and active coping relative to control. Among participants with low baseline hopelessness, we found no intervention effects. PRP-AP was not more effective than PRP-A alone. We found no intervention effects on clinical levels of depression or anxiety. These findings suggest that cognitive-behavioral interventions can be beneficial when delivered by school teachers and counselors. These interventions may be most helpful to students with elevated hopelessness.

Study of a Two-Step Centrifugation Protocol for Concentrating Cells and Growth Factors in Bovine Platelet-Rich Plasma

PubMed Central

Gutiérrez, Claudia M.; López, Catalina

2017-01-01

There is a lack of information about the methods used for bovine platelet-rich plasma (PRP)/platelet-rich gel (PRG) procurement, including information on platelet (PLT), white blood cell (WBC) in PRP, and growth factor release from PRG supernatants. The aims of this study were to compare and to correlate the PLT, WBC, transforming growth factor beta-1 (TGF-β1), and platelet-derived growth factor BB (PDGF-BB) concentrations in bovine whole blood, plasma, and four PRP layers and their respective PRG supernatants: A and B (obtained by a single centrifugation tube method at 720g/5 min) and C and D (obtained by a double centrifugation tube method, by using two centrifugation episodes at 720g/5 min). PLT and WBC counts were significantly higher in PRP-C, followed by whole blood, PRP-A, PRP-B, and PRP-D. TGF-β1 concentrations were significantly higher in PRG-B supernatants and its correspondent PRP-B lysate when compared to the other PRG supernatants and plasma. Supernatants from PRG-A, PRG-B, and PRG-D had equivalent TGF-β1 concentrations. PDGF-BB concentrations were not statistically different between the hemoderivatives. Significant Pearson correlations were noted between PLT counts and WBC counts (0.8) and between PLT counts and PLT distribution width (0.6). Further studies should be performed to assess the potential clinical applications of these PRPs. PMID:29214094

The prion protein has RNA binding and chaperoning properties characteristic of nucleocapsid protein NCP7 of HIV-1.

PubMed

Gabus, C; Derrington, E; Leblanc, P; Chnaiderman, J; Dormont, D; Swietnicki, W; Morillas, M; Surewicz, W K; Marc, D; Nandi, P; Darlix, J L

2001-06-01

Transmissible spongiform encephalopathies are fatal neurodegenerative diseases associated with the accumulation of a protease-resistant form of the prion protein (PrP). Although PrP is conserved in vertebrates, its function remains to be identified. In vitro PrP binds large nucleic acids causing the formation of nucleoprotein complexes resembling human immunodeficiency virus type 1 (HIV-1) nucleocapsid-RNA complexes and in vivo MuLV replication accelerates the scrapie infectious process, suggesting possible interactions between retroviruses and PrP. Retroviruses, including HIV-1 encode a major nucleic acid binding protein (NC protein) found within the virus where 2000 NC protein molecules coat the dimeric genome. NC is required in virus assembly and infection to chaperone RNA dimerization and packaging and in proviral DNA synthesis by reverse transcriptase (RT). In HIV-1, 5'-leader RNA/NC interactions appear to control these viral processes. This prompted us to compare and contrast the interactions of human and ovine PrP and HIV-1 NCp7 with HIV-1 5'-leader RNA. Results show that PrP has properties characteristic of NCp7 with respect to viral RNA dimerization and proviral DNA synthesis by RT. The NC-like properties of huPrP map to the N-terminal region of huPrP. Interestingly, PrP localizes in the membrane and cytoplasm of PrP-expressing cells. These findings suggest that PrP is a multifunctional protein possibly participating in nucleic acid metabolism.

Genetic and physical interactions between factors involved in both cell cycle progression and pre-mRNA splicing in Saccharomyces cerevisiae.

PubMed Central

Ben-Yehuda, S; Dix, I; Russell, C S; McGarvey, M; Beggs, J D; Kupiec, M

2000-01-01

The PRP17/CDC40 gene of Saccharomyces cerevisiae functions in two different cellular processes: pre-mRNA splicing and cell cycle progression. The Prp17/Cdc40 protein participates in the second step of the splicing reaction and, in addition, prp17/cdc40 mutant cells held at the restrictive temperature arrest in the G2 phase of the cell cycle. Here we describe the identification of nine genes that, when mutated, show synthetic lethality with the prp17/cdc40Delta allele. Six of these encode known splicing factors: Prp8p, Slu7p, Prp16p, Prp22p, Slt11p, and U2 snRNA. The other three, SYF1, SYF2, and SYF3, represent genes also involved in cell cycle progression and in pre-mRNA splicing. Syf1p and Syf3p are highly conserved proteins containing several copies of a repeated motif, which we term RTPR. This newly defined motif is shared by proteins involved in RNA processing and represents a subfamily of the known TPR (tetratricopeptide repeat) motif. Using two-hybrid interaction screens and biochemical analysis, we show that the SYF gene products interact with each other and with four other proteins: Isy1p, Cef1p, Prp22p, and Ntc20p. We discuss the role played by these proteins in splicing and cell cycle progression. PMID:11102353

Genetic and physical interactions between factors involved in both cell cycle progression and pre-mRNA splicing in Saccharomyces cerevisiae.

PubMed

Ben-Yehuda, S; Dix, I; Russell, C S; McGarvey, M; Beggs, J D; Kupiec, M

2000-12-01

The PRP17/CDC40 gene of Saccharomyces cerevisiae functions in two different cellular processes: pre-mRNA splicing and cell cycle progression. The Prp17/Cdc40 protein participates in the second step of the splicing reaction and, in addition, prp17/cdc40 mutant cells held at the restrictive temperature arrest in the G2 phase of the cell cycle. Here we describe the identification of nine genes that, when mutated, show synthetic lethality with the prp17/cdc40Delta allele. Six of these encode known splicing factors: Prp8p, Slu7p, Prp16p, Prp22p, Slt11p, and U2 snRNA. The other three, SYF1, SYF2, and SYF3, represent genes also involved in cell cycle progression and in pre-mRNA splicing. Syf1p and Syf3p are highly conserved proteins containing several copies of a repeated motif, which we term RTPR. This newly defined motif is shared by proteins involved in RNA processing and represents a subfamily of the known TPR (tetratricopeptide repeat) motif. Using two-hybrid interaction screens and biochemical analysis, we show that the SYF gene products interact with each other and with four other proteins: Isy1p, Cef1p, Prp22p, and Ntc20p. We discuss the role played by these proteins in splicing and cell cycle progression.

Site-Specific Targeting of Platelet-Rich Plasma via Superparamagnetic Nanoparticles

PubMed Central

Talaie, Tara; Pratt, Stephen J.P.; Vanegas, Camilo; Xu, Su; Henn, R. Frank; Yarowsky, Paul; Lovering, Richard M.

2015-01-01

Background: Muscle strains are one of the most common injuries treated by physicians. Standard conservative therapy for acute muscle strains usually involves short-term rest, ice, and nonsteroidal anti-inflammatory medications, but there is no clear consensus regarding treatments to accelerate recovery. Recently, clinical use of platelet-rich plasma (PRP) has gained momentum as an option for therapy and is appealing for many reasons, most notably because it provides growth factors in physiological proportions and it is autologous, safe, easily accessible, and potentially beneficial. Local delivery of PRP to injured muscles can hasten recovery of function. However, specific targeting of PRP to sites of tissue damage in vivo is a major challenge that can limit its efficacy. Hypothesis: Location of PRP delivery can be monitored and controlled in vivo with noninvasive tools. Study Design: Controlled laboratory study. Methods: Superparamagnetic iron oxide nanoparticles (SPIONs) can be visualized by both magnetic resonance imaging (MRI) (in vivo) and fluorescence microscopy (after tissue harvesting). PRP was labeled with SPIONs and administered by intramuscular injections of SPION-containing platelets. MRI was used to monitor the ability to manipulate and retain the location of PRP in vivo by placement of an external magnet. Platelets were isolated from whole blood and incubated with SPIONs. Following SPION incubation with PRP, a magnetic field was used to manipulate platelet location in culture dishes. In vivo, the tibialis anterior (TA) muscles of anesthetized Sprague-Dawley rats were injected with SPION-containing platelets, and MRI was used to track platelet position with and without a magnet worn over the TA muscles for 4 days. Results: The method used to isolate PRP yielded a high concentration (almost 4-fold increase) of platelets. In vitro experiments showed that the platelets successfully took up SPIONs and then rapidly responded to an applied magnetic field. Platelets without SPIONs did not respond to the magnetic field. In vivo experiments showed that the SPION-containing platelets can be noninvasively maintained at a specific site with the application of a magnetic field. Conclusion: PRP may be a useful product in the clinical treatment of muscle injuries, but one problem with using it as a therapeutic tool is retaining PRP at the site of injury. This study proposes a potential solution, with findings that support this method at the cell, whole muscle, and in vivo levels. Controlling the location of PRP will allow the clustering of PRP to enrich the target area with growth factors and will prevent loss of platelets over time at the site of injury. PMID:25664326

The Relationship between High Flow Nasal Cannula Flow Rate and Effort of Breathing in Children.

PubMed

Weiler, Thomas; Kamerkar, Asavari; Hotz, Justin; Ross, Patrick A; Newth, Christopher J L; Khemani, Robinder G

2017-10-01

To use an objective metric of effort of breathing to determine optimal high flow nasal cannula (HFNC) flow rates in children <3 years of age. Single-center prospective trial in a 24-bed pediatric intensive care unit of children <3 years of age on HFNC. We measured the percent change in pressure∙rate product (PRP) (an objective measure of effort of breathing) as a function of weight-indexed flow rates of 0.5, 1.0, 1.5, and 2.0 L/kg/minute. For a subgroup of patients, 2 different HFNC delivery systems (Fisher & Paykel [Auckland, New Zealand] and Vapotherm [Exeter, New Hampshire]) were compared. Twenty-one patients (49 titration episodes) were studied. The most common diagnoses were bronchiolitis and pneumonia. Overall, there was a significant difference in the percent change in PRP from baseline (of 0.5 L/kg/minute) with increasing flow rates for the entire cohort (P < .001) with largest change at 2.0 L/kg/min (-21%). Subgroup analyses showed no significant difference in percent change in PRP from baseline when comparing the 2 different HFNC delivery systems (P = .12). Patients ≤8 kg experienced a larger percent change in PRP as HFNC flow rates were increased (P = .001) than patients >8 kg. The optimal HFNC flow rate to reduce effort of breathing in infants and young children is approximately 1.5-2.0 L/kg/minute with more benefit seen in children ≤8 kg. Copyright © 2017 Elsevier Inc. All rights reserved.

Mammalian prions: tolerance to sequence changes-how far?

PubMed

Salamat, Muhammad Khalid; Munoz-Montesino, Carola; Moudjou, Mohammed; Rezaei, Human; Laude, Hubert; Béringue, Vincent; Dron, Michel

2013-01-01

Upon prion infection, abnormal prion protein (PrP (Sc) ) self-perpetuate by conformational conversion of α-helix-rich PrP (C) into β sheet enriched form, leading to formation and deposition of PrP (Sc) aggregates in affected brains. However the process remains poorly understood at the molecular level and the regions of PrP critical for conversion are still debated. Minimal amino acid substitutions can impair prion replication at many places in PrP. Conversely, we recently showed that bona fide prions could be generated after introduction of eight and up to 16 additional amino acids in the H2-H3 inter-helix loop of PrP. Prion replication also accommodated the insertions of an octapeptide at different places in the last turns of H2. This reverse genetic approach reveals an unexpected tolerance of prions to substantial sequence changes in the protease-resistant part which is associated with infectivity. It also demonstrates that conversion does not require the presence of a specific sequence in the middle of the H2-H3 area. We discuss the implications of our findings according to different structural models proposed for PrP (Sc) and questioned the postulated existence of an N- or C-terminal prion domain in the protease-resistant region.

Soluble Aβ aggregates can inhibit prion propagation.

PubMed

Sarell, Claire J; Quarterman, Emma; Yip, Daniel C-M; Terry, Cassandra; Nicoll, Andrew J; Wadsworth, Jonathan D F; Farrow, Mark A; Walsh, Dominic M; Collinge, John

2017-11-01

Mammalian prions cause lethal neurodegenerative diseases such as Creutzfeldt-Jakob disease (CJD) and consist of multi-chain assemblies of misfolded cellular prion protein (PrP C ). Ligands that bind to PrP C can inhibit prion propagation and neurotoxicity. Extensive prior work established that certain soluble assemblies of the Alzheimer's disease (AD)-associated amyloid β-protein (Aβ) can tightly bind to PrP C , and that this interaction may be relevant to their toxicity in AD. Here, we investigated whether such soluble Aβ assemblies might, conversely, have an inhibitory effect on prion propagation. Using cellular models of prion infection and propagation and distinct Aβ preparations, we found that the form of Aβ assemblies which most avidly bound to PrP in vitro also inhibited prion infection and propagation. By contrast, forms of Aβ which exhibit little or no binding to PrP were unable to attenuate prion propagation. These data suggest that soluble aggregates of Aβ can compete with prions for binding to PrP C and emphasize the bidirectional nature of the interplay between Aβ and PrP C in Alzheimer's and prion diseases. Such inhibitory effects of Aβ on prion propagation may contribute to the apparent fall-off in the incidence of sporadic CJD at advanced age where cerebral Aβ deposition is common. © 2017 The Authors.

The use of platelet-rich plasma to augment conservative and surgical treatment of hip and pelvic disorders

PubMed Central

Kraeutler, Matthew J.; Garabekyan, Tigran; Mei-Dan, Omer

2016-01-01

Summary Background In recent years, platelet-rich plasma (PRP) has gained popularity within the orthopaedic community as a treatment modality to enhance tissue healing. Purpose This review aims to concisely present the current indications for PRP injections in the treatment of hip and pelvic pathologies and to describe some novel applications for PRP which have not yet been reported in the literature. Methods We reviewed the literature on the non-operative and operative indications for PRP in the treatment of hip and pelvic pathologies. Conclusions With regard to hip and pelvic pathologies, PRP injections are used most commonly as a non-operative intervention, and have been described in the literature to treat osteoarthritis of the hip joint as well as tendinopathy of the hamstrings, adductor longus, and gluteus medius. In contrast, most of the surgical applications of PRP for the hip are novel, with few reported studies in the literature. Because of the increasing awareness of PRP’s beneficial effects on musculoskeletal healing and thus the growing number of indications for its use, this review also describes some novel applications for PRP, including osteitis pubis, post-microfracture of the hip, tears of the rectus femoris, and avulsion of the sartorius muscle. Level of evidence V. PMID:28066748

Effect of diabetic retinopathy and panretinal photocoagulation on retinal nerve fiber layer and optic nerve appearance.

PubMed

Lim, Michele C; Tanimoto, Suzana A; Furlani, Bruno A; Lum, Brent; Pinto, Luciano M; Eliason, David; Prata, Tiago S; Brandt, James D; Morse, Lawrence S; Park, Susanna S; Melo, Luiz A S

2009-07-01

To determine if panretinal photocoagulation (PRP) alters retinal nerve fiber layer (RNFL) thickness and optic nerve appearance. Patients with diabetes who did and did not undergo PRP and nondiabetic control subjects were enrolled in a prospective study. Participants underwent optical coherence tomography of the peripapillary retina and optic nerve. Stereoscopic optic nerve photographs were graded in a masked fashion. Ninety-four eyes of 48 healthy individuals, 89 eyes of 55 diabetic patients who did not undergo PRP, and 37 eyes of 24 subjects with diabetes who underwent PRP were included in this study. Eyes that had been treated with PRP had thinner peripapillary RNFL compared with the other groups; this was statistically significantly different in the inferior (P = .004) and nasal (P = .003) regions. Optic nerve cupping did not increase with severity of disease classification, but the proportion of optic nerves graded as suspicious for glaucoma or as having nonglaucomatous optic neuropathy did (P = .008). These grading categories were associated with thinner RNFL measurements. Diabetic eyes that have been treated with PRP have thinner RNFL than nondiabetic eyes. Optic nerves in eyes treated with PRP are more likely to be graded as abnormal, but their appearance is not necessarily glaucomatous and may be related to thinning of the RNFL.

Prion disease susceptibility is affected by β-structure folding propensity and local side-chain interactions in PrP

PubMed Central

Khan, M. Qasim; Sweeting, Braden; Mulligan, Vikram Khipple; Arslan, Pharhad Eli; Cashman, Neil R.; Pai, Emil F.; Chakrabartty, Avijit

2010-01-01

Prion diseases occur when the normally α-helical prion protein (PrP) converts to a pathological β-structured state with prion infectivity (PrPSc). Exposure to PrPSc from other mammals can catalyze this conversion. Evidence from experimental and accidental transmission of prions suggests that mammals vary in their prion disease susceptibility: Hamsters and mice show relatively high susceptibility, whereas rabbits, horses, and dogs show low susceptibility. Using a novel approach to quantify conformational states of PrP by circular dichroism (CD), we find that prion susceptibility tracks with the intrinsic propensity of mammalian PrP to convert from the native, α-helical state to a cytotoxic β-structured state, which exists in a monomer–octamer equilibrium. It has been controversial whether β-structured monomers exist at acidic pH; sedimentation equilibrium and dual-wavelength CD evidence is presented for an equilibrium between a β-structured monomer and octamer in some acidic pH conditions. Our X-ray crystallographic structure of rabbit PrP has identified a key helix-capping motif implicated in the low prion disease susceptibility of rabbits. Removal of this capping motif increases the β-structure folding propensity of rabbit PrP to match that of PrP from mouse, a species more susceptible to prion disease. PMID:21041683

Prion disease susceptibility is affected by beta-structure folding propensity and local side-chain interactions in PrP.

PubMed

Khan, M Qasim; Sweeting, Braden; Mulligan, Vikram Khipple; Arslan, Pharhad Eli; Cashman, Neil R; Pai, Emil F; Chakrabartty, Avijit

2010-11-16

Prion diseases occur when the normally α-helical prion protein (PrP) converts to a pathological β-structured state with prion infectivity (PrP(Sc)). Exposure to PrP(Sc) from other mammals can catalyze this conversion. Evidence from experimental and accidental transmission of prions suggests that mammals vary in their prion disease susceptibility: Hamsters and mice show relatively high susceptibility, whereas rabbits, horses, and dogs show low susceptibility. Using a novel approach to quantify conformational states of PrP by circular dichroism (CD), we find that prion susceptibility tracks with the intrinsic propensity of mammalian PrP to convert from the native, α-helical state to a cytotoxic β-structured state, which exists in a monomer-octamer equilibrium. It has been controversial whether β-structured monomers exist at acidic pH; sedimentation equilibrium and dual-wavelength CD evidence is presented for an equilibrium between a β-structured monomer and octamer in some acidic pH conditions. Our X-ray crystallographic structure of rabbit PrP has identified a key helix-capping motif implicated in the low prion disease susceptibility of rabbits. Removal of this capping motif increases the β-structure folding propensity of rabbit PrP to match that of PrP from mouse, a species more susceptible to prion disease.

Platelet-rich plasma for arthroscopic repair of medium to large rotator cuff tears: a randomized controlled trial.

PubMed

Jo, Chris Hyunchul; Shin, Ji Sun; Shin, Won Hyoung; Lee, Seung Yeon; Yoon, Kang Sup; Shin, Sue

2015-09-01

Two main questions about the use of platelet-rich plasma (PRP) for regeneration purposes are its effect on the speed of healing and the quality of healing. Despite recent numerous studies, evidence is still lacking in this area, especially in a representative patient population with medium to large rotator cuff tears. To assess the efficacy of PRP augmentation on the speed and quality of healing in patients undergoing arthroscopic repair for medium to large rotator cuff tears. Randomized controlled trial; Level of evidence, 1. A total of 74 patients scheduled for arthroscopic repair of medium to large rotator cuff tears were randomly assigned to undergo either PRP-augmented repair (PRP group) or conventional repair (conventional group). In the PRP group, 3 PRP gels (3 × 3 mL) were applied to each patient between the torn end and the greater tuberosity. The primary outcome was the Constant score at 3 months after surgery. Secondary outcome measures included the visual analog scale (VAS) for pain, range of motion (ROM), muscle strength, overall satisfaction and function, functional scores, retear rate, and change in the cross-sectional area (CSA) of the supraspinatus muscle. There was no difference between the 2 groups in the Constant score at 3 months (P > .05). The 2 groups had similar results on the VAS for pain, ROM, muscle strength, overall satisfaction and function, and other functional scores (all P > .05) except for the VAS for worst pain (P = .043). The retear rate of the PRP group (3.0%) was significantly lower than that of the conventional group (20.0%) (P = .032). The change in 1-year postoperative and immediately postoperative CSAs was significantly different between the 2 groups: -36.76 ± 45.31 mm(2) in the PRP group versus -67.47 ± 47.26 mm(2) in the conventional group (P = .014). Compared with repairs without PRP augmentation, the current PRP preparation and application methods for medium to large rotator cuff repairs significantly improved the quality, as evidenced by a decreased retear rate and increased CSA of the supraspinatus, but not the speed of healing. However, further studies may be needed to investigate the effects of PRP on the speed of healing without risking the quality. © 2015 The Author(s).

Platelet-rich plasma in orthopedic therapy: a comparative systematic review of clinical and experimental data in equine and human musculoskeletal lesions.

PubMed

Brossi, Patrícia M; Moreira, Juliana J; Machado, Thaís S L; Baccarin, Raquel Y A

2015-04-22

This systematic review aimed to present and critically appraise the available information on the efficacy of platelet rich plasma (PRP) in equine and human orthopedic therapeutics and to verify the influence of study design and methodology on the assumption of PRP's efficacy. We searched Medline, PubMed, Embase, Bireme and Google Scholar without restrictions until July 2013. Randomized trials, human cohort clinical studies or case series with a control group on the use of PRP in tendons, ligaments or articular lesions were included. Equine clinical studies on the same topics were included independently of their design. Experimental studies relevant to the clarification of PRP's effects and mechanisms of action in tissues of interest, conducted in any animal species, were selected. This review included 123 studies. PRP's beneficial effects were observed in 46.7% of the clinical studies, while the absence of positive effects was observed in 43.3%. Among experimental studies, 73% yielded positive results, and 7.9% yielded negative results. The most frequent flaws in the clinical trials' designs were the lack of a true placebo group, poor product characterization, insufficient blinding, small sampling, short follow-up periods, and adoption of poor outcome measures. The methods employed for PRP preparation and administration and the selected outcome measures varied greatly. Poor study design was a common feature of equine clinical trials. From studies in which PRP had beneficial effects, 67.8% had an overall high risk of bias. From the studies in which PRP failed to exhibit beneficial effects, 67.8% had an overall low risk of bias. Most experimental studies revealed positive effects of PRP. Although the majority of equine clinical studies yielded positive results, the human clinical trials' results failed to corroborate these findings. In both species, beneficial results were more frequently observed in studies with a high risk of bias. The use of PRP in musculoskeletal lesions, although safe and promising, has still not shown strong evidence in clinical scenarios.

The effect of corticosteroid versus platelet-rich plasma injection therapies for the management of lateral epicondylitis: A systematic review

PubMed Central

Ben-Nafa, Walid; Munro, Wendy

2018-01-01

Introduction: Lateral epicondylitis is a common musculoskeletal disorder of the upper limb. Corticosteroid injection has been widely used as a major mode of treatment. However, better understanding of the pathophysiology of the disease led to a major change in treating the disease, with new options including platelet-rich plasma (PRP) are currently used. Objectives/research aim: To systematically evaluate the effect of corticosteroid versus PRP injections for the treatment of LE. Hypothesis: PRP injections provide longer-term therapeutic effect and less rate of complications compared to corticosteroid injection. Level of evidence: Level 2 evidence (4 included studies are of level 1 evidence, 1 study of level 2 evidence). Design: Systematic Review (according to PRISMA guidelines). Methods: Eleven databases used to search for relevant primary studies comparing the effects of corticosteroid and PRP injections for the treatment of LE. Quality appraisal of studies performed using Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0, CASP Randomised Controlled Trial Checklist, and SIGN Methodology Checklist 2. Results: 732 papers were identified. Five randomised controlled trials (250 Patients) met the inclusion criteria. Clinical findings: Corticosteroid injections provided rapid symptomatic improvement with maximum effect at 6/8/8 weeks before symptoms recurrence, whereas PRP showed slower ongoing improvements up to 24/52/104 weeks(3 studies). Corticosteroid showed more rapid symptomatic improvement of symptoms compared to PRP up to the study end-point of 3 months(1 study). Comparable therapeutic effects of corticosteroid and PRP were observed at 6 weeks(1 study). Ultrasonographic Findings: (1) Doppler activity decreased more significantly in patients who received corticosteroid compared to PRP. (2) Reduced tendon thickness and more patients with cortical erosion noted in corticosteroid group whereas increased tendon thickness and less number of patients with common extensor tendon tears noted in PRP group. (3) Fewer patients reported Probe-induced tenderness and oedema in the common extensor tendon in both corticosteroid and PRP groups (2 studies). Conclusion: Corticosteroid injections provide rapid therapeutic effect in the short-term with recurrence of symptoms afterwards, compared to the relatively slower but longer-term effect of platelet-rich plasma. PMID:29561260

Optimisation of a double-centrifugation method for preparation of canine platelet-rich plasma.

PubMed

Shin, Hyeok-Soo; Woo, Heung-Myong; Kang, Byung-Jae

2017-06-26

Platelet-rich plasma (PRP) has been expected for regenerative medicine because of its growth factors. However, there is considerable variability in the recovery and yield of platelets and the concentration of growth factors in PRP preparations. The aim of this study was to identify optimal relative centrifugal force and spin time for the preparation of PRP from canine blood using a double-centrifugation tube method. Whole blood samples were collected in citrate blood collection tubes from 12 healthy beagles. For the first centrifugation step, 10 different run conditions were compared to determine which condition produced optimal recovery of platelets. Once the optimal condition was identified, platelet-containing plasma prepared using that condition was subjected to a second centrifugation to pellet platelets. For the second centrifugation, 12 different run conditions were compared to identify the centrifugal force and spin time to produce maximal pellet recovery and concentration increase. Growth factor levels were estimated by using ELISA to measure platelet-derived growth factor-BB (PDGF-BB) concentrations in optimised CaCl 2 -activated platelet fractions. The highest platelet recovery rate and yield were obtained by first centrifuging whole blood at 1000 g for 5 min and then centrifuging the recovered platelet-enriched plasma at 1500 g for 15 min. This protocol recovered 80% of platelets from whole blood and increased platelet concentration six-fold and produced the highest concentration of PDGF-BB in activated fractions. We have described an optimised double-centrifugation tube method for the preparation of PRP from canine blood. This optimised method does not require particularly expensive equipment or high technical ability and can readily be carried out in a veterinary clinical setting.

Platelet-Rich Plasma Treatment With Physical Therapy in Chronic Partial Supraspinatus Tears.

PubMed

Ilhanli, Ilker; Guder, Necip; Gul, Murat

2015-09-01

Despite the insufficient evidence, due to potential contribution to the improvement, platelet-rich plasma (PRP) is emerging as a promising method. The aim of this study was to assess the effectiveness of PRP injection in partial supraspinatus tears by comparing with physical therapy (PT). Seventy patients with chronic partial supraspinatus tears in magnetic resonance imaging were randomized into two groups; PRP (n = 35) and PT (n = 35). Before the treatment, at the end of the treatment and at the 12th month after the end of the treatment, range of motion (ROM), visual analog scale (VAS) for pain, Disabilities of Arm, Shoulder and Hand questionnaire (DASH), Neer's, Hawkins' and drop arm tests and Beck Depression Inventory were investigated. Statistical analysis was made for 62 subjects (PRP group, n = 30; PT group, n = 32). There were no differences between the groups according to demographic data. At the 12th month after the end of the treatment, significant improvement in ROM was detected in both groups, pain was reduced significantly in both groups and improvement of the DASH score was observed in both groups. At all the evaluation steps, increases in ROM degrees were significantly higher in the PT group than the PRP group. For VAS in activity and in rest, after the treatment, improvement was higher in the PT group than the PRP group. However, improvement of the DASH score of the PRP group was significantly better than the PT group. When we compared with PT, PRP seemed to be a well-tolerated application which showed promising results in patients with chronic partial supraspinatus tears.

Evaluation of a group cognitive-behavioral depression prevention program for young adolescents: A randomized effectiveness trial

PubMed Central

Gillham, Jane E.; Reivich, Karen J.; Brunwasser, Steven M.; Freres, Derek R.; Chajon, Norma D.; Megan Kash-MacDonald, V.; Chaplin, Tara M.; Abenavoli, Rachel M.; Matlin, Samantha L.; Gallop, Robert J.; Seligman, Martin E.P.

2015-01-01

Objective Depression is a common psychological problem in adolescence. Recent research suggests that group cognitive-behavioral interventions can reduce and prevent symptoms of depression in youth. Few studies have tested the effectiveness of such interventions when delivered by school teachers and counselors (as opposed to research team staff). Method We evaluated the effectiveness of the Penn Resiliency Program for adolescents (PRP-A), a school-based group intervention that targets cognitive behavioral risk factors for depression. We randomly assigned 408 middle school students (ages 10-15) to one of three conditions: PRP-A, PRP-AP (in which adolescents participated in PRP-A and parents were invited to attend a parent intervention component), or a school-as-usual control. Adolescents completed measures of depression and anxiety symptoms, cognitive style, and coping at baseline, immediately after the intervention, and at 6-month follow-up. Results PRP-A reduced depression symptoms relative to the school as usual control. Baseline levels of hopelessness moderated intervention effects. Among participants with average and high levels of hopelessness, PRP (A and AP) significantly improved depression symptoms, anxiety symptoms, hopelessness, and active coping relative to control. Among participants with low baseline hopelessness, we found no intervention effects. PRP-AP was not more effective than PRP-A alone. We found no intervention effects on clinical levels of depression or anxiety. Conclusion These findings suggest that cognitive-behavioral interventions can be beneficial when delivered by school teachers and counselors. These interventions may be most helpful to students with elevated hopelessness. PMID:22889296

Effects of washed platelets vs platelet-rich plasma on the proliferation and mineralization of rat dental pulp cells.

PubMed

Zhang, L; Xie, Y H; Lin, B R

2015-08-14

We examined the effects of washed platelets (WPLTs) and platelet-rich plasma (PRP) on the proliferation and mineralization of rat dental pulp cells. Rat dental pulp cells were separated, cultured, and identified. Medium containing 1, 10, 100, or 500 mL/L PRP or WPLTs was added to 4th generation cells. The MTS method was used to determine cell proliferation. Alizarin red staining was used to observe the formation of mineralized nodules after cell mineralization and induction for 10 and 20 days under different culture conditions, and the areas of the mineralized nodules formed 20 days after induction were computed. The addition of 1, 10, and 100 mL/L WPLTs or PRP significantly promoted rat dental pulp cell proliferation (P < 0.05) whereas 500 mL/L WPLTs or PRP had no significant effect (P > 0.05). Under the same concentrations, no significant differences on cell proliferation were observed between WPLT and PRP treatments (P > 0.05 in all groups). After 10 days mineralization and culture, the 100 and 500 mL/L WPLT and PRP group positive nodule rates were significantly higher than those of the low concentration and the control groups (P < 0.05). After 20 days, the areas of the mineralized nodules formed in the 100 and 500 mL/L WPLT and PRP groups were significantly larger than those in the control group (P < 0.05). These results demonstrate that both WPLTs and PRP are equally able to significantly promote the proliferation and calcification of rat dental pulp cells under a certain range of concentrations.

Histologic Evaluation of Osseous Regeneration Following Combination Therapy With Platelet-Rich Plasma and Bio-Oss in a Rat Calvarial Critical-Size Defect Model.

PubMed

DeNicolo, Philip J; Guyton, M Kelly; Cuenin, Michael F; Hokett, Steven D; Sharawy, Mohamed; Borke, James; McPherson, James C

2015-10-01

Platelet-rich plasma (PRP) is an autogenous source of growth factors shown to facilitate human bone growth. Bio-Oss, an osteoconductive xenograft, is used clinically to regenerate periodontal defects, restore dental alveolar ridges, and facilitate sinus-lift procedures. The purpose of this study was to analyze whether a combination of PRP and Bio-Oss would enhance bone regeneration better than either material alone. PRP and/or Bio-Oss were administered in an 8-mm critical-size defect (CSD) rat calvarial model of bone defect between 2 polytetrafluoroethylene membranes to prevent soft tissue incursion. Eight weeks after the induction of the CSD, histologic sections were stained with hematoxylin and eosin stain and analyzed via light microscopy. Qualitative analyses revealed new bone regeneration in all 4 groups. The Bio-Oss and PRP plus Bio-Oss groups demonstrated greater areas of closure in the defects than the control or PRP-only groups because of the space-maintaining ability of Bio-Oss. The groups grafted with Bio-Oss showed close contact with new bone growth throughout the defects, suggesting a stronger graft. The use of PRP alone or in combination with Bio-Oss, however, did not appear to enhance osseous regeneration at 8 weeks. Areas grafted with Bio-Oss demonstrated greater space-maintaining capacity than controls, and PRP was an effective vehicle for placement of the Bio-Oss. However, at 8 weeks this study was unable to demonstrate a significant advantage of using PRP plus Bio-Oss over using Bio-Oss alone.

Could single nucleotide polymorphisms influence on the efficacy of platelet-rich plasma in the treatment of sport injuries?

PubMed Central

Pruna, Ricard; Til, Lluis; Artells, Rosa

2014-01-01

Summary Platelet-rich plasma (PRP) is a new powerful biological tool in sports medicine, when used to treat tendon, ligament and muscle injuries. PRP is a fraction of autologous whole blood containing an increased number of platelets and a wide variety of cytokines that can improve and accelerate the healing of various tissues. An analysis of the literature shows promising pre-clinical results for PRP treatment, but there is a lack of solid clinical proof to support its use in sports medicine, and in fact, clinical findings on individual responses to PRP treatment are contradictory. These contradictions may be due to interindividual differences in the presence of single nucleotide polymorphisms (SNPs) in genes related to PRPs and/or their receptors. These SNPs can determine a greater or lesser response to this treatment and consequently a shorter or longer recovery time. We have focused our attention in the study of genes related to PRP with the aim to develope a genetic profile that will identify the individuals and injuries most likely to benefit from PRP treatment. PMID:24932449

A single amino acid (Asp159) from the dog prion protein suppresses the toxicity of the mouse prion protein in Drosophila

PubMed Central

Sanchez-Garcia, J; Jensen, K; Zhang, Y; Rincon-Limas, DE; Fernandez-Funez, P

2016-01-01

Misfolding of the prion protein (PrP) is the key step in the transmission of spongiform pathologies in humans and several animals. Although PrP is highly conserved in mammals, a few changes in the sequence of endogenous PrP are proposed to confer protection to dogs, which were highly exposed to prion during the mad-cow epidemics. D159 is a unique amino acid found in PrP from dogs and other canines that was shown to alter surface charge, but its functional relevance has never been tested in vivo. Here, we show in transgenic Drosophila that introducing the N159D substitution on mouse PrP decreases its turnover. Additionally, mouse PrP-N159D demonstrates no toxicity and accumulates no pathogenic conformations, suggesting that a single D159 substitution is sufficient to prevent PrP conformational change and pathogenesis. Understanding the mechanisms mediating the protective activity of D159 is likely to lessen the burden of prion diseases in humans and domestic animals. PMID:27477054

Enzymatic characteristics of an ApaH-like phosphatase, PrpA, and a diadenosine tetraphosphate hydrolase, ApaH, from Myxococcus xanthus.

PubMed

Sasaki, Masashi; Takegawa, Kaoru; Kimura, Yoshio

2014-09-17

We characterized the activities of the Myxococcus xanthus ApaH-like phosphatases PrpA and ApaH, which share homologies with both phosphoprotein phosphatases and diadenosine tetraphosphate (Ap4A) hydrolases. PrpA exhibited a phosphatase activity towards p-nitrophenyl phosphate (pNPP), tyrosine phosphopeptide and tyrosine-phosphorylated protein, and a weak hydrolase activity towards ApnA and ATP. In the presence of Mn(2+), PrpA hydrolyzed Ap4A into AMP and ATP, whereas in the presence of Co(2+) PrpA hydrolyzed Ap4A into two molecules of ADP. ApaH exhibited high phosphatase activity towards pNPP, and hydrolase activity towards ApnA and ATP. Mn(2+) was required for ApaH-mediated pNPP dephosphorylation and ATP hydrolysis, whereas Co(2+) was required for ApnA hydrolysis. Thus, PrpA and ApaH may function mainly as a tyrosine protein phosphatase and an ApnA hydrolase, respectively. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Current concept for the use of PRP in arthroscopic surgery.

PubMed

Nourissat, G; Mainard, D; Kelberine, F

2013-12-01

PRP is commonly used in sports medicine and because it is supposed to increase healing capacities of damaged tissues, it is expected to be increase efficiency or god clinical outcomes when added to arthroscopic surgical procedure. The current review of literature explores the evidence-based medicine supporting the use of PRP in three arthroscopic related disorders. Regarding cartilage lesions of the knee, many studies are exploring several aspect of cartilage lesion treatment. It appears that PRP, in some protocols with specific concentration, should be more efficient than current therapies in the treatment of early stages of knee OA, but only in the field of rheumatology or sport medicine, not when used during surgery. PRP have been used in ACL reconstruction, no benefit has been reported in any study regarding clinical or radiological outcomes. In shoulder cuff disorder, to date, no clinical benefit nor increased healing rate have been clearly reported. Thus, in 2013, it is clear that there is no evidence base medicine data supporting the use of PRP in arthroscopic surgery. Copyright © 2013. Published by Elsevier Masson SAS.

PRP Augmentation for ACL Reconstruction

PubMed Central

Di Matteo, Berardo; Kon, Elizaveta; Marcacci, Maurilio

2015-01-01

Current research is investigating new methods to enhance tissue healing to speed up recovery time and decrease the risk of failure in Anterior Cruciate Ligament (ACL) reconstructive surgery. Biological augmentation is one of the most exploited strategies, in particular the application of Platelet Rich Plasma (PRP). Aim of the present paper is to systematically review all the preclinical and clinical papers dealing with the application of PRP as a biological enhancer during ACL reconstructive surgery. Thirty-two studies were included in the present review. The analysis of the preclinical evidence revealed that PRP was able to improve the healing potential of the tendinous graft both in terms of histological and biomechanical performance. Looking at the available clinical evidence, results were not univocal. PRP administration proved to be a safe procedure and there were some evidences that it could favor the donor site healing in case of ACL reconstruction with patellar tendon graft and positively contribute to graft maturation over time, whereas the majority of the papers did not show beneficial effects in terms of bony tunnels/graft area integration. Furthermore, PRP augmentation did not provide superior functional results at short term evaluation. PMID:26064903

Clinical Applications of Platelet-Rich Plasma in Patellar Tendinopathy

PubMed Central

Jeong, D. U.; Lee, C.-R.; Lee, J. H.; Pak, J.; Kang, L.-W.; Jeong, B. C.

2014-01-01

Platelet-rich plasma (PRP), a blood derivative with high concentrations of platelets, has been found to have high levels of autologous growth factors (GFs), such as transforming growth factor-β (TGF-β), platelet-derived growth factor (PDGF), fibroblastic growth factor (FGF), vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF). These GFs and other biological active proteins of PRP can promote tissue healing through the regulation of fibrosis and angiogenesis. Moreover, PRP is considered to be safe due to its autologous nature and long-term usage without any reported major complications. Therefore, PRP therapy could be an option in treating overused tendon damage such as chronic tendinopathy. Here, we present a systematic review highlighting the clinical effectiveness of PRP injection therapy in patellar tendinopathy, which is a major cause of athletes to retire from their respective careers. PMID:25136568

The Prion Concept and Synthetic Prions.

PubMed

Legname, Giuseppe; Moda, Fabio

2017-01-01

Transmissible spongiform encephalopathies or prion diseases are a group of fatal neurodegenerative diseases caused by unconventional infectious agents, known as prions (PrP Sc ). Prions derive from a conformational conversion of the normally folded prion protein (PrP C ), which acquires pathological and infectious features. Moreover, PrP Sc is able to transmit the pathological conformation to PrP C through a mechanism that is still not well understood. The generation of synthetic prions, which behave like natural prions, is of fundamental importance to study the process of PrP C conversion and to assess the efficacy of therapeutic strategies to interfere with this process. Moreover, the ability of synthetic prions to induce pathology in animals confirms that the pathological properties of the prion strains are all enciphered in abnormal conformations, characterizing these infectious agents. © 2017 Elsevier Inc. All rights reserved.

PRP5: a helicase-like protein required for mRNA splicing in yeast.

PubMed Central

Dalbadie-McFarland, G; Abelson, J

1990-01-01

A 96-kDa protein predicted by the DNA sequence of the Saccharomyces cerevisiae PRP5 gene contains a domain that bears a striking resemblance to a family of RNA helicases characterized by the conserved amino acid sequence Asp-Glu-Ala-Asp (D-E-A-D). Previous work indicated that the product of the PRP5 gene is required for splicing and that spliceosome assembly does not occur in its absence. However, its precise role in splicing and the nature of its biochemical activity remained unknown. To examine the role of PRP5 in splicing, we cloned the gene by complementation of a temperature-sensitive mutation and determined its DNA sequence. We discuss here the possible roles for an RNA helicase in splicing and for the activity of the PRP5 protein. Images PMID:2349233

Post-mortem immunodiagnosis of scrapie and bovine spongiform encephalopathy.

PubMed

Farquhar, C F; Somerville, R A; Ritchie, L A

1989-01-01

Two polyclonal antisera were raised in rabbits against the scrapie-associated fibril protein (PrP) prepared from sheep and mice which were terminally infected with experimental scrapie. The anti-mouse PrP serum identifies the proteins of scrapie-associated fibrils (SAF) from all the host species studied (mouse, hamster, sheep and goat) and bovine spongiform encephalopathy (BSE) fibrils from cow. The anti-sheep PrP serum displays species restricted immunoreactivity. While it identifies several PrP polypeptides from terminally affected sheep, goat and cow material, only the highest molecular weight band is recognised from hamster and there is no detection of mouse PrP. The use of these antisera in routine laboratory testing at post mortem provides a highly sensitive test for scrapie and BSE and may allow the identification of infected animals prior to the onset of clinical signs.

Combination of platelet-rich plasma with degradable bioactive borate glass for segmental bone defect repair.

PubMed

Zhang, Ya-Dong; Wang, Gang; Sun, Yan; Zhang, Chang-Qing

2011-02-01

Porous scaffold biomaterials may offer a clinical alternative to bone grafts; however, scaffolds alone are typically insufficient to heal large bone defects. Numerous studies have demonstrated that osteoinductive growth factor significantly improves bone repair. In this study, a strategy combining degradable bioactive borate glass (BG) scaffolds with platelet-rich plasma (PRP) was tested. The bone defect was filled with BG alone, BG combined with autologous PRP or left empty. Bone formation was analyzed at 4, 8 and 12 weeks using both histology and radiology. The PRP treated group yielded better bone formation than the pure BG scaffold as determined by both histology and microcomputer tomography after 12 weeks. In conclusion, PRP improved bone healing in a diaphyseal rabbit model on BG. The combination of PRP and BG may be an effective approach to repair critical defects.

The effect of platelet-rich plasma on clinical outcomes in lateral epicondylitis.

PubMed

Ahmad, Zafar; Brooks, Roger; Kang, Sertaz-Niel; Weaver, Holly; Nunney, Ian; Tytherleigh-Strong, Graham; Rushton, Neil

2013-11-01

To evaluate the evidence for application of platelet-rich plasma (PRP) in lateral epicondylitis. We carried out a systematic review of the current evidence on the effects of PRP in lateral epicondylitis on clinical outcomes. We performed a comprehensive search of the PubMed, Medline, Cochrane, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Embase databases using various combinations of the commercial names of each PRP preparation and "lateral epicondylitis" (with its associated terms), looking specifically at human studies. Data validity was assessed and collected on clinical outcome. Nine studies met the inclusion criteria, of which 5 were randomized controlled trials. Two cohort studies showed that PRP improved clinical satisfaction scores. One case-control study showed that PRP yielded a significantly greater improvement in symptoms compared with bupivacaine. Two randomized controlled trials compared the effect of injections of PRP and blood. Only 1 of the studies noted a significant difference at the 6-week time point. Three randomized controlled trials compared corticosteroids with PRP. Two of the smaller trials, which had follow-up periods of 6 weeks and 3 months, showed no significant difference between treatment groups. The largest randomized controlled trial found that PRP had significant benefit compared with corticosteroids with regard to pain and Disabilities of the Arm, Shoulder and Hand scores at 1- and 2-year time points. This review highlights the limited but evolving evidence for the use of PRP in lateral epicondylitis; however, further research is required to understand the concentration and preparation that facilitate the best clinical outcome. Characterizing the timing of the intervention would optimize the health economics behind the decision to treat for the patient and health care provider. Level III, systematic review of Level I to III studies. Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Lumbar Intradiskal Platelet-Rich Plasma (PRP) Injections: A Prospective, Double-Blind, Randomized Controlled Study.

PubMed

Tuakli-Wosornu, Yetsa A; Terry, Alon; Boachie-Adjei, Kwadwo; Harrison, Julian R; Gribbin, Caitlin K; LaSalle, Elizabeth E; Nguyen, Joseph T; Solomon, Jennifer L; Lutz, Gregory E

2016-01-01

To determine whether single injections of autologous platelet-rich plasma (PRP) into symptomatic degenerative intervertebral disks will improve participant-reported pain and function. Prospective, double-blind, randomized controlled study. Outpatient physiatric spine practice. Adults with chronic (≥6 months), moderate-to-severe lumbar diskogenic pain that was unresponsive to conservative treatment. Participants were randomized to receive intradiskal PRP or contrast agent after provocative diskography. Data on pain, physical function, and participant satisfaction were collected at 1 week, 4 weeks, 8 weeks, 6 months, and 1 year. Participants in the control group who did not improve at 8 weeks were offered the option to receive PRP and subsequently followed. Functional Rating Index (FRI), Numeric Rating Scale (NRS) for pain, the pain and physical function domains of the 36-item Short Form Health Survey, and the modified North American Spine Society (NASS) Outcome Questionnaire were used. Forty-seven participants (29 in the treatment group, 18 in the control group) were analyzed by an independent observer with a 92% follow-up rate. Over 8 weeks of follow-up, there were statistically significant improvements in participants who received intradiskal PRP with regards to pain (NRS Best Pain) (P = .02), function (FRI) (P = .03), and patient satisfaction (NASS Outcome Questionnaire) (P = .01) compared with controls. No adverse events of disk space infection, neurologic injury, or progressive herniation were reported following the injection of PRP. Participants who received intradiskal PRP showed significant improvements in FRI, NRS Best Pain, and NASS patient satisfaction scores over 8 weeks compared with controls. Those who received PRP maintained significant improvements in FRI scores through at least 1 year of follow-up. Although these results are promising, further studies are needed to define the subset of participants most likely to respond to biologic intradiskal treatment and the ideal cellular characteristics of the intradiskal PRP injectate. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Platelet rich plasma versus corticosteroid injection for plantar fasciitis: A comparative study.

PubMed

Jain, Kowshik; Murphy, Philip N; Clough, Timothy M

2015-12-01

Intractable plantar fasciitis can be a difficult condition to treat. Early results of platelet rich plasma (PRP) injection have been promising. We compared PRP to traditional cortisone injection in the treatment of chronic cases of plantar fasciitis resistant to traditional nonoperative management. The aim of the study was to compare the efficacy of PRP to that of Steroid at 3, 6 and 12 months after injection. 60 heels with intractable plantar fasciitis who had failed conservative treatment were randomised to receive either PRP or Steroid injection. All patients were assessed with the Roles-Maudsley (RM) Score, Visual Analogue Score (VAS) for pain and the American Orthopaedic Foot and Ankle Society (AOFAS) score. Data was collected prospectively on the cohort, pre-treatment, at 3, 6 and 12 months post injection and the results were compared. Pre-injection, the two groups were well matched with no statistically significant difference. At 3 months, all three outcome scores had significantly improved from their pretreatment level in both groups. The scores in the Steroid arm were marginally better than in the PRP arm, but this difference was not statistically significant. At 6 months, there was no statistically significant difference between the two groups, though there was a trend for the PRP scores to become better than the Steroid scores. At 12 months, the RM, VAS and AOFAS scores in the PRP arm (1.9, 3.3 and 88.5) were significantly better than the Steroid arm (2.6, 5.3 and 75) with P values of .013, .028 and .033, respectively. PRP is as effective as Steroid injection at achieving symptom relief at 3 and 6 months after injection, for the treatment of plantar fasciitis, but unlike Steroid, its effect does not wear off with time. At 12 months, PRP is significantly more effective than Steroid, making it better and more durable than cortisone injection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biologic injections for osteoarthritis and articular cartilage damage: can we modify disease?

PubMed

Shi, Weilong J; Tjoumakaris, Fotios P; Lendner, Mayan; Freedman, Kevin B

2017-09-01

The purpose of the present investigation is to conduct a systematic review of the literature to review the clinical results of platelet rich plasma (PRP) and mesenchymal stem cell treatments (MSC) (biologics) for articular cartilage lesions and osteoarthritis of the knee. A search of the PubMed, EMBASE, and Cochrane databases was performed to identify studies involving biologic therapy for osteoarthritis or osteochondral defects. Only Level I-III clinical trials with at least 3-month follow-up were included. Outcome data was gathered on any patient-completed surveys, 2nd look arthroscopy, follow-up imaging, biopsy/histology results, and any adverse effects of treatment. Thirty-three articles met our inclusion criteria. There was a total of 21 PRP studies in the study. All PRP studies showed clinical improvement with PRP therapies in outcomes surveys measuring patient satisfaction, pain, and function. Two studies reported no significant difference in improvement compared to hyaluronic acid (HA). Similarly, the 7/9 MSC studies showed improvement. One study found BM-MSC implantation was not significantly superior to matrix assisted chondrocyte implantation (MACI), while one reported peripheral blood stem cells (PBSC) did not significantly improve outcomes over HA. Of the three studies looking at a combination of MSC/PRP, two found MSC/PRP combination did not improve outcomes compared to MSC or PRP therapy alone. The one PRP study that had a 2nd look arthroscopy reported increases cartilage regeneration with PRP. All 8 MSC studies with follow-up MRI and all 7 MSC studies with 2nd look arthroscopy showed improvement in cartilage regeneration in terms of coverage, fill of the defect, and/or firmness of the new cartilage. Current data suggests that, of the two treatments, MSC provides more significant disease modifying effect; however, further research needs to be done to compare these two treatments and determine if there is a synergetic effect when combined.

Management of refractory pityriasis rubra pilaris: challenges and solutions

PubMed Central

Moretta, Gaia; De Luca, Erika V; Di Stefani, Alessandro

2017-01-01

Pityriasis rubra pilaris (PRP) is a rare chronic inflammatory papulosquamous skin disease. Its clinical presentation and evolution is very variable. The most frequent clinical features are follicular papules, progressing to yellow-orange erythroderma with round small areas of normal skin and the well-demarcated palmoplantar keratoderma. Actually, six different types of PRP have been described based on clinical characteristics, age of onset, and prognosis. The pathogenesis is still unknown, and treatment can be challenging. Available treatments are mainly based on case reports or case series of clinical experience because no controlled randomized trials have never been performed because of the rarity of the condition. Traditional systemic treatment consists in retinoids, which are actually considered as first-line therapy, but refractory cases that do not respond or relapse after drug interruption do exist. In recent years, numerous reports have demonstrated the efficacy of new agents such as biological drugs. This article is an overview on available therapeutic options, in particular for refractory forms of PRP. PMID:29184428

Increasing platelet concentrations in leukocyte-reduced platelet-rich plasma decrease collagen gene synthesis in tendons.

PubMed

Boswell, Stacie G; Schnabel, Lauren V; Mohammed, Hussni O; Sundman, Emily A; Minas, Tom; Fortier, Lisa A

2014-01-01

Platelet-rich plasma (PRP) is used for the treatment of tendinopathy. There are numerous PRP preparations, and the optimal combination of platelets and leukocytes is not known. Within leukocyte-reduced PRP (lrPRP), there is a plateau effect of platelet concentration, with increasing platelet concentrations being detrimental to extracellular matrix synthesis. Controlled laboratory study. Different formulations of lrPRP with respect to the platelet:leukocyte ratio were generated from venous blood of 8 horses. Explants of the superficial digital flexor tendon were cultured in lrPRP products for 96 hours. Platelet-derived growth factor-BB (PDGF-BB), tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), and interleukin-1β (IL-1β) concentrations were determined in the media by enzyme-linked immunosorbent assay. Gene expression in tendon tissue for collagen type I and III (COL1A1 and COL3A1, respectively), matrix metalloproteinase-3 and -13 (MMP-3 and MMP-13, respectively), cartilage oligomeric matrix protein (COMP), and IL-1β was determined. Data were divided into 3 groups of lrPRP based on the ratio of platelets:leukocytes and evaluated to determine the effect of platelet concentration. Complete blood counts verified leukocyte reduction and platelet enrichment in all PRP preparations. In the lrPRP preparation, the anabolic growth factors PDGF-BB and TGF-β1 were increased with increasing platelet concentrations, and the catabolic cytokine IL-1β was decreased with increasing platelet concentrations. Increasing the platelet concentration resulted in a significant reduction in COL1A1 and COL3A1 synthesis in tendons. Increasing the platelet concentration within lrPRP preparations results in the delivery of more anabolic growth factors and less proinflammatory cytokines, but the biological effect on tendons is diminished metabolism as indicated by a decrease in the synthesis of both COL1A1 and COL3A1. Together, this information suggests that minimizing leukocytes in PRP is more important than maximizing platelet numbers with respect to decreasing inflammation and enhancing matrix gene synthesis. This study suggests that reducing leukocytes to minimize catabolic signaling appears to be more important than increasing platelets in an effort to maximize anabolic signaling. Further, a maximum biological threshold of benefit was demonstrated with regard to the number of platelets beyond which further increases in platelet concentration did not result in further anabolic upregulation. In vivo investigations documenting the use of platelets for the treatment of tendinopathy are justified as well as further in vitro characterization of the ideal PRP product for the treatment of tendinopathy and other musculoskeletal applications.

Use of a Cyclooxygenase-2 Inhibitor Does Not Inhibit Platelet Activation or Growth Factor Release From Platelet-Rich Plasma.

PubMed

Ludwig, Hilary C; Birdwhistell, Kate E; Brainard, Benjamin M; Franklin, Samuel P

2017-12-01

It remains unestablished whether use of cyclooxygenase (COX)-2 inhibitors impairs platelet activation and anabolic growth factor release from platelets in platelet-rich plasma (PRP). The purpose of this study was to assess the effects of a COX-2 inhibitor on platelet activation and anabolic growth factor release from canine PRP when using a clinically applicable PRP activator and to determine whether a 3-day washout would be sufficient to abrogate any COX-2 inhibitor-related impairment on platelet function. Controlled laboratory study. Ten healthy dogs underwent blood collection and PRP preparation. Dogs were then administered a COX-2 inhibitor for 7 days, after which PRP preparation was repeated. The COX-2 inhibitor was continued for 4 more days and PRP preparation performed a third time, 3 days after discontinuation of the COX-2 inhibitor. Immediately after PRP preparation, the PRP was divided into 4 aliquots: 2 unactivated and 2 activated using human γ-thrombin (HGT). One activated and 1 unactivated sample were assessed using flow cytometry for platelet expression of CD62P and platelet-bound fibrinogen using the canine activated platelet-1 (CAP1) antibody. The 2 remaining samples were centrifuged and the supernatant assayed for transforming growth factor-β1 (TGF-β1), platelet-derived growth factor-BB (PDGF-BB), and thromboxane B2 (TXB2) concentrations. Differences in platelet activation and TGF-β1, PDGF-BB, and TXB2 concentrations over the 3 study weeks were evaluated using a 1-way repeated-measures ANOVA, and comparisons between activated and unactivated samples within a study week were assessed with paired t tests. There were no statistically significant ( P > .05) effects of the COX-2 inhibitor on percentage of platelets positive for CD62P or CAP1 or on concentrations of TGF-β1, PDGF-BB, or TXB2. All unactivated samples had low levels of activation or growth factor concentrations and significantly ( P < .05) greater activation and growth factor concentrations in HGT-activated samples. This COX-2 inhibitor did not impair platelet activation, growth factor release, or TXB2 production in this canine PRP when using HGT as an activator. Studies are warranted to determine whether COX-2 inhibitors affect platelet activation and growth factor release from human PRPs. These results suggest that there is no need to withhold a COX-2 inhibitor before PRP preparation, particularly if thrombin is going to be used to activate the PRP. This is clinically relevant information because many patients who are candidates for PRP therapy for treatment of musculoskeletal injury are also using COX-2 inhibitors.

A serum and platelet-rich plasma serotonin assay using liquid chromatography tandem mass spectrometry for monitoring of neuroendocrine tumor patients.

PubMed

Korse, Catharina M; Buning-Kager, Johanna C G M; Linders, Theodora C; Heijboer, Annemieke C; van den Broek, Daan; Tesselaar, Margot E T; van Tellingen, Olaf; van Rossum, Huub H

2017-06-01

Serotonin is used for the diagnosis and follow-up of neuroendocrine tumors (NET). We describe the analytical and clinical validation of a liquid chromatography tandem mass spectrometry (LC-MS/MS) based serotonin assay for serum and platelet-rich plasma (PRP). An LC-MS/MS based method for serum and PRP serotonin was validated by determination of assay imprecision, carry-over, linearity, interference, recovery, sample stability and a matrix/method comparison of serum and PRP serotonin was made with whole blood serotonin. Furthermore, upper limits of normal were determined and serotonin concentrations of healthy individuals, 14 NET patients without evidence of disease and 51 NET patients with evidence of disease were compared. For serum and PRP fractions, total assay imprecision was <5%. All correlation coefficients were 0.98 and the serum and platelet-rich serotonin upper limit of normal were 5.5nmol/10 9 platelet and 5.1nmol/10 9 platelet, respectively. NET patients with confirmed evidence of disease had significantly higher serum and PRP serotonin levels when compared to NET patients without evidence of disease and healthy volunteers. LC-MS/MS based serum and PRP serotonin assays were developed with suitable analytical characteristics. Furthermore, serum and PRP serotonin was found to be useful for monitoring NET patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Collagen IX is required for the integrity of collagen II fibrils and the regulation of vascular plexus formation in Zebrafish caudal fins

PubMed Central

Huang, Cheng-chen; Wang, Tai-Chuan; Lin, Bo-Hung; Wang, Yi-Wen; Johnson, Stephen L.; Yu, John

2013-01-01

Capillary plexuses form during both vasculogenesis and angiogenesis and are remodeled into mature vessel types and patterns which are delicately orchestrated with the sizes and shapes of other tissues and organs. We isolated a zebrafish mutation named prp (for persistent plexus) that causes persistent formation of vascular plexuses in the caudal fins and consequent mispatterning of bony fin rays and the fin shape. Detailed analyses revealed that the prp mutation causes a significant reduction in the size and dramatic structural defects in collagen II-rich extracellular matrices called actinotrichia of both embryonic finfolds and adult fins. prp was mapped to chromosome 19 and found to encode the zebrafish collagen9α1 (col9α1) gene which is abundantly expressed in developing finfolds. A point mutation resulting in a leucine-to-histidine change was detected in the thrombospondin domain of the col9α1 gene in prp. Morpholino-mediated knockdown of col9α1 phenocopied the prp small-finfold phenotype in wild-type embryos, and an injection of plasmids containing the col9α1 cDNA into prp embryos locally restored the finfold size. Furthermore, we found that osteoblasts in prp mutants were mispatterned apparently following the abnormal vascular plexus pattern, demonstrating that blood vessels play an important role in the patterning of bony rays in zebrafish caudal fins. PMID:19501583

Collagen IX is required for the integrity of collagen II fibrils and the regulation of vascular plexus formation in zebrafish caudal fins.

PubMed

Huang, Cheng-chen; Wang, Tai-Chuan; Lin, Bo-Hung; Wang, Yi-Wen; Johnson, Stephen L; Yu, John

2009-08-15

Capillary plexuses form during both vasculogenesis and angiogenesis and are remodeled into mature vessel types and patterns which are delicately orchestrated with the sizes and shapes of other tissues and organs. We isolated a zebrafish mutation named prp (for persistent plexus) that causes persistent formation of vascular plexuses in the caudal fins and consequent mispatterning of bony fin rays and the fin shape. Detailed analyses revealed that the prp mutation causes a significant reduction in the size and dramatic structural defects in collagen II-rich extracellular matrices called actinotrichia of both embryonic finfolds and adult fins. prp was mapped to chromosome 19 and found to encode the zebrafish collagen9alpha1 (col9alpha1) gene which is abundantly expressed in developing finfolds. A point mutation resulting in a leucine-to-histidine change was detected in the thrombospondin domain of the col9alpha1 gene in prp. Morpholino-mediated knockdown of col9alpha1 phenocopied the prp small-finfold phenotype in wild-type embryos, and an injection of plasmids containing the col9alpha1 cDNA into prp embryos locally restored the finfold size. Furthermore, we found that osteoblasts in prp mutants were mispatterned apparently following the abnormal vascular plexus pattern, demonstrating that blood vessels play an important role in the patterning of bony rays in zebrafish caudal fins.

Infectious prions and proteinopathies.

PubMed

Barron, Rona M

2017-01-02

Transmissible spongiform encephalopathies (TSEs) are caused by an infectious agent that is thought to consist of only misfolded and aggregated prion protein (PrP). Unlike conventional micro-organisms, the agent spreads and propagates by binding to and converting normal host PrP into the abnormal conformer, increasing the infectious titre. Synthetic prions, composed of refolded fibrillar forms of recombinant PrP (rec-PrP) have been generated to address whether PrP aggregates alone are indeed infectious prions. In several reports, the development of TSE disease has been described following inoculation and passage of rec-PrP fibrils in transgenic mice and hamsters. However in studies described here we show that inoculation of rec-PrP fibrils does not always cause clinical TSE disease or increased infectious titre, but can seed the formation of PrP amyloid plaques in PrP-P101L knock-in transgenic mice (101LL). These data are reminiscent of the "prion-like" spread of misfolded protein in other models of neurodegenerative disease following inoculation of transgenic mice with pre-formed amyloid seeds. Protein misfolding, even when the protein is PrP, does not inevitably lead to the development of an infectious TSE disease. It is possible that most in vivo and in vitro produced misfolded PrP is not infectious and that only a specific subpopulation is associated with infectivity and neurotoxicity.

In Vitro Studies on the Degradability, Bioactivity, and Cell Differentiation of PRP/AZ31B Mg Alloys Composite Scaffold.

PubMed

Zou, Jian; Shi, Zhongmin; Xu, Hongwei; Li, Xiaolin

2017-01-01

In recent years, more and more methods have been developed to improve the bioactivity of the biodegradable materials in bone tissue regeneration. In present study, we used rat mesenchymal stem cells (rMSCs) to evaluate the outcomes of Mg alloys (AZ31B, Magnesium, and Aluminum) and Platelet-rich plasma (PRP)/Mg alloys on rMSCs biocompatibility and osteogenic differentiation. Water absorption experiments indicated that both bare AZ31B and PRP/AZ31B were capable of absorbing large amounts of water. But the water absorption ratio for PRP/AZ31B was significantly higher than that for bare AZ31B. The degradability experiments implied that both samples degraded at same speed. rMSCs on the surface of AZ31B distributed more and better than those on the AZ31B scaffold. In ALP activity experiment, the activity of rMSCs on the PRP/AZ31B was markedly higher than that on the AZ31B scaffolds on the 7th day and 14th day. qRT-PCR also showed that OPN and OCN were expressed in both samples. OPN and OCN expression in PRP/AZ31B sample were higher than those in bare AZ31B samples. In summary, the in vitro study implied that AZ31B combined with PRP could remarkably improve cell seeding, attachment, proliferation, and differentiation.

Effect of Platelet Rich Plasma Combined with Chitosan Biodegradable Film on Full-Thickness Wound Healing in Rat Model

PubMed Central

Mohammadi, Rahim; Mehrtash, Moein; Mehrtash, Moeid; Hassani, Nava; Hassanpour, Ali

2016-01-01

Objective: To assess the effects of platelet rich plasma (PRP) with chitosan biodegradable film on full thickness wound healing in rat. Methods: This was an experimental study being performed in 2015 during a 4-month period. Twenty-four male white Wistar rats were divided into four groups of 12 rats each, randomly: Control group (SHAM) with creation of wounds and no treatment, PRP group with creation of wounds and application of one milliliter PRP, Chitosan group (CHIT) with dressing the wound with chitosan and CHIT/PRP group with application of one mL PRPand dressing the wound with chitosan. The wounds were created by cutting healthy skin.Wound size was measured on 6, 9, 12, 15, 18 and 21 post surgery and was compared between groups. Results: Reduction in wound area, hydroxyproline contents and biomechanical parametersindicated there was significant difference (p=0.001) between group CHIT/PRP and other groups. Biomechanical testing was performed on day 9 post surgery in incisional model. Quantitative histological studies and mean rank of the qualitative studies demonstrated that there was significant difference (p<0.001) between group CHIT/PRP and other groups. Conclusion: PRP with chitosan have beneficial effects on wounds repair and could be suggested for treating various types of wounds in animals and human being. PMID:27162924

Platelet-Rich Plasma, Especially When Combined with a TGF-β Inhibitor Promotes Proliferation, Viability and Myogenic Differentiation of Myoblasts In Vitro

PubMed Central

Kelc, Robi; Trapecar, Martin; Gradisnik, Lidija; Rupnik, Marjan Slak; Vogrin, Matjaz

2015-01-01

Regeneration of skeletal muscle after injury is limited by scar formation, slow healing time and a high recurrence rate. A therapy based on platelet-rich plasma (PRP) has become a promising lead for tendon and ligament injuries in recent years, however concerns have been raised that PRP-derived TGF-β could contribute to fibrotic remodelling in skeletal muscle after injury. Due to the lack of scientific grounds for a PRP -based muscle regeneration therapy, we have designed a study using human myogenic progenitors and evaluated the potential of PRP alone and in combination with decorin (a TGF-β inhibitor), to alter myoblast proliferation, metabolic activity, cytokine profile and expression of myogenic regulatory factors (MRFs). Advanced imaging multicolor single-cell analysis enabled us to create a valuable picture on the ratio of quiescent, activated and terminally committed myoblasts in treated versus control cell populations. Finally high-resolution confocal microscopy validated the potential of PRP and decorin to stimulate the formation of polynucleated myotubules. PRP was shown to down-regulate fibrotic cytokines, increase cell viability and proliferation, enhance the expression of MRFs, and contribute to a significant myogenic shift during differentiation. When combined with decorin further synergistc effects were identified. These results suggest that PRP could not only prevent fibrosis but could also stimulate muscle commitment, especially when combined with a TGF-β inhibitor. PMID:25679956

Increasing platelet concentration in platelet-rich plasma inhibits anterior cruciate ligament cell function in three-dimensional culture.

PubMed

Yoshida, Ryu; Cheng, Mingyu; Murray, Martha M

2014-02-01

Tissue engineering is one new strategy being developed to treat ACL ruptures. One such approach is bio-enhanced ACL repair, where a suture repair is supplemented with a bio-active scaffold containing platelets. However, the optimal concentration of platelets to stimulate ACL healing is not known. We hypothesized that increasing platelet concentrations in the scaffold would enhance critical cell behaviors. Porcine ACL fibroblasts were obtained from explant culture and suspended in platelet poor plasma (PPP), 1× platelet-rich plasma (PRP), 3× PRP, 5× PRP, or phosphate buffered saline (PBS). The cell suspensions were cultured in a 3D collagen scaffold. Cellular metabolism (MTT assay), apoptosis (TUNEL assay), and gene expression for type I and type III collagen were measured. 1× PRP significantly outperformed 5× PRP in all parameters studied: Type I and III collagen gene expression, apoptosis prevention, and cell metabolism stimulation. ACL fibroblasts cultured with 1× PRP had the highest type I and type III collagen gene expression. 1× PRP and PPP groups had the highest cell metabolism and lowest apoptosis rates. Concentration of platelets had significant effects on the behavior of ACL fibroblasts; thus, it is an important parameter that should be specified in clinical or basic science studies. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Evaluation of 3D-Printed Polycaprolactone Scaffolds Coated with Freeze-Dried Platelet-Rich Plasma for Bone Regeneration.

PubMed

Li, Junda; Chen, Meilin; Wei, Xiaoying; Hao, Yishan; Wang, Jinming

2017-07-19

Three-dimensional printing is one of the most promising techniques for the manufacturing of scaffolds for bone tissue engineering. However, a pure scaffold is limited by its biological properties. Platelet-rich plasma (PRP) has been shown to have the potential to improve the osteogenic effect. In this study, we improved the biological properties of scaffolds by coating 3D-printed polycaprolactone (PCL) scaffolds with freeze-dried and traditionally prepared PRP, and we evaluated these scaffolds through in vitro and in vivo experiments. In vitro, we evaluated the interaction between dental pulp stem cells (DPSCs) and the scaffolds by measuring cell proliferation, alkaline phosphatase (ALP) activity, and osteogenic differentiation. The results showed that freeze-dried PRP significantly enhanced ALP activity and the mRNA expression levels of osteogenic genes (ALP, RUNX2 (runt-related gene-2), OCN (osteocalcin), OPN (osteopontin)) of DPSCs ( p < 0.05). In vivo, 5 mm calvarial defects were created, and the PRP-PCL scaffolds were implanted. The data showed that compared with traditional PRP-PCL scaffolds or bare PCL scaffolds, the freeze-dried PRP-PCL scaffolds induced significantly greater bone formation ( p < 0.05). All these data suggest that coating 3D-printed PCL scaffolds with freeze-dried PRP can promote greater osteogenic differentiation of DPSCs and induce more bone formation, which may have great potential in future clinical applications.

A systematic review of the effects of platelet rich plasma on outcomes for patients with knee osteoarthritis and following total knee arthroplasty.

PubMed

Muchedzi, Tendai Aswad; Roberts, Simon B

2017-09-21

Platelet rich plasma (PRP) has been suggested to be effective in the management of knee osteoarthritis. Review of current literature reveals conflicting evidence regarding the benefits of PRP in treating knee OA. Preclinical evidence supports the use of PRP injections to promote a favorable environment for joint tissue healing, targeting not only cartilage but also synovial and meniscal tissues which has a positive effect on delaying the progression of OA. Growth factors found in platelet granules are postulated to influence outcomes in knee OA and after total knee arthroplasty (TKA). A systematic review of studies investigating the use of PRP in knee osteoarthritis and following TKA, was performed by searching the following databases for randomised clinical trials and pseudo-randomised clinical and comparative trials comparing the use of PRP to treat knee osteoarthritis and following TKA: MedLine, EMBASE, Science Direct, PubMed, and the Cochrane Library. The primary outcomes were patient reported measures including pain (visual analog scale (VAS)), quality of life scores, and knee function. A total of 2328 participants were analyzed across 17 included studies and pooled results showed a statistically significant reduction in pain in favor of PRP following TKA but not in non-surgical management of knee OA (P < 0.0001 and 0.13 respectively). No clinical benefit of PRP was found on quality of life and knee function (P = 0.07 and 0.05) following TKA, although a statistical improvement in knee function was demonstrated in patients with knee OA after PRP injection (P < 0.0001). There was no statistically significant clinical benefit of PRP on secondary outcomes including wound scores and length of hospital stay (p = 0.33 and 0.31, respectively). There was no statistically significant difference in respect to blood loss and overall symptoms in favor of PRP compared to control group following TKA (p = 0.37). This systematic review demonstrated no long-term statistically significant improvement in patient validated outcomes and secondary outcomes both in patients with knee OA or following TKA for OA. However PRP has been shown to have short to medium-term benefits in pain control after TKA and activities of daily living in patients with OA. Copyright © 2017 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Effects of pulsed electromagnetic fields and platelet rich plasma in preventing osteoclastogenesis in an in vitro model of osteolysis.

PubMed

Tschon, Matilde; Veronesi, Francesca; Contartese, Deyanira; Sartori, Maria; Martini, Lucia; Vincenzi, Fabrizio; Ravani, Annalisa; Varani, Katia; Fini, Milena

2018-03-01

Osteolysis is the main limiting cause for the survival of an orthopedic prosthesis and is accompanied by an enhancement in osteoclastogenesis and inflammation, due by wear debris formation. Unfortunately therapeutic treatments, besides revision surgery, are not available. The aim of the present study was to evaluate the effects of Pulsed Electro Magnetic Fields (PEMFs) and platelet rich plasma (PRP), alone or in combination, in an in vitro model of osteolysis. Rats peripheral blood mononuclear cells were cultured on Ultra High Molecular Weight Polyethylene particles and divided into four groups of treatments: (1) PEMF stimulation (12 hr/day, 2.5 mT, 75 Hz, 1.3 ms pulse duration); (2) 10% PRP; (3) combination of PEMFs, and PRP; (4) no treatment. Treatments were performed for 3 days and cell viability, osteoclast number, expression of genes related to osteoclastogenesis and inflammation and production of pro-inflammatory cytokines were assessed up to 14 days. PEMF stimulation exerted best results because it increased cell viability at early time points and counteracted osteoclastogenesis at 14 days. On the contrary, PRP increased osteoclastogenesis and reduced cell viability in comparison to PEMFs alone. The combination of PEMFs and PRP increased cell viability over time and reduced osteoclastogenesis in comparison to PRP alone. However, these positive results did not exceed the level achieved by PEMF alone. At longer time points PEMF could not counteract osteoclastogenesis increased by PRP. Regarding inflammation, all treatments maintained the production of pro-inflammatory cytokines at low level, although PRP increased the level of interleukin 1 beta. © 2017 Wiley Periodicals, Inc.

Platelet-rich plasma affects bacterial growth in vitro.

PubMed

Mariani, Erminia; Filardo, Giuseppe; Canella, Valentina; Berlingeri, Andrea; Bielli, Alessandra; Cattini, Luca; Landini, Maria Paola; Kon, Elizaveta; Marcacci, Maurilio; Facchini, Andrea

2014-09-01

Platelet-rich plasma (PRP), a blood derivative rich in platelets, is a relatively new technique used in tissue regeneration and engineering. The increased quantity of platelets makes this formulation of considerable value for their role in tissue healing and microbicidal activity. This activity was investigated against five of the most important strains involved in nosocomial infections (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Streptococcus faecalis) to understand the prophylactic role of pure (P)-PRP. Microbicidal proteins released from activated P-PRP platelets were also determined. The microbicidal activity of P-PRP and platelet-poor plasma (PPP) was evaluated on different concentrations of the five bacterial strains incubated for 1, 2, 4 and 18 h and plated on agar for 18-24 h. P-PRP and PPP-released microbicidal proteins were evaluated by means of multiplex bead-based immunoassays. P-PRP and PPP inhibited bacterial growth for up to 2 h of incubation. The effect of P-PRP was significantly higher than that of PPP, mainly at the low seeding concentrations and/or shorter incubation times, depending on the bacterial strain. Chemokine (C-C motif) ligand-3, chemokine (C-C motif) ligand-5 and chemokine (C-X-C motif) ligand-1 were the molecules mostly related to Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus faecalis inhibition. Escherichia coli and Klebsiella pneumoniae were less influenced. The present results show that P-PRP might supply an early protection against bacterial contaminations during surgical interventions because the inhibitory activity is already evident from the first hour of treatment, which suggests that physiological molecules supplied in loco might be important in the time frame needed for the activation of the innate immune response. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Toll like receptors TLR1/2, TLR6 and MUC5B as binding interaction partners with cytostatic proline rich polypeptide 1 in human chondrosarcoma.

PubMed

Galoian, Karina; Abrahamyan, Silva; Chailyan, Gor; Qureshi, Amir; Patel, Parthik; Metser, Gil; Moran, Alexandra; Sahakyan, Inesa; Tumasyan, Narine; Lee, Albert; Davtyan, Tigran; Chailyan, Samvel; Galoyan, Armen

2018-01-01

Metastatic chondrosarcoma is a bone malignancy not responsive to conventional therapies; new approaches and therapies are urgently needed. We have previously reported that mTORC1 inhibitor, antitumorigenic cytostatic proline rich polypeptide 1 (PRP-1), galarmin caused a significant upregulation of tumor suppressors including TET1/2 and SOCS3 (known to be involved in inflammatory processes), downregulation of oncoproteins and embryonic stem cell marker miR-302C and its targets Nanog, c-Myc and Bmi-1 in human chondrosarcoma. To understand better the mechanism of PRP-1 action it was very important to identify the receptor it binds to. Nuclear pathway receptor and GPCR assays indicated that PRP-1 receptors are not G protein coupled, neither do they belong to family of nuclear or orphan receptors. In the present study, we have demonstrated that PRP-1 binding interacting partners belong to innate immunity pattern recognition toll like receptors TLR1/2 and TLR6 and gel forming secreted mucin MUC5B. MUC5B was identified as PRP-1 receptor in human chondrosarcoma JJ012 cell line using Ligand-receptor capture technology. Toll like receptors TLR1/2 and TLR6 were identified as binding interaction partners with PRP-1 by western blot analysis in human chondrosarcoma JJ012 cell line lysates. Immunocytochemistry experiments confirmed the finding and indicated the localization of PRP-1 receptors in the tumor nucleus predominantly. TLR1/2, TLR6 and MUC5B were downregulated in human chondrosarcoma and upregulated in dose-response manner upon PRP-1 treatment. Experimental data indicated that in this cellular context the mentioned receptors had tumor suppressive function.

Platelet-Rich Plasma Treatment With Physical Therapy in Chronic Partial Supraspinatus Tears

PubMed Central

Ilhanli, Ilker; Guder, Necip; Gul, Murat

2015-01-01

Background: Despite the insufficient evidence, due to potential contribution to the improvement, platelet-rich plasma (PRP) is emerging as a promising method. Objectives: The aim of this study was to assess the effectiveness of PRP injection in partial supraspinatus tears by comparing with physical therapy (PT). Patients and Methods: Seventy patients with chronic partial supraspinatus tears in magnetic resonance imaging were randomized into two groups; PRP (n = 35) and PT (n = 35). Before the treatment, at the end of the treatment and at the 12th month after the end of the treatment, range of motion (ROM), visual analog scale (VAS) for pain, Disabilities of Arm, Shoulder and Hand questionnaire (DASH), Neer’s, Hawkins’ and drop arm tests and Beck Depression Inventory were investigated. Results: Statistical analysis was made for 62 subjects (PRP group, n = 30; PT group, n = 32). There were no differences between the groups according to demographic data. At the 12th month after the end of the treatment, significant improvement in ROM was detected in both groups, pain was reduced significantly in both groups and improvement of the DASH score was observed in both groups. At all the evaluation steps, increases in ROM degrees were significantly higher in the PT group than the PRP group. For VAS in activity and in rest, after the treatment, improvement was higher in the PT group than the PRP group. However, improvement of the DASH score of the PRP group was significantly better than the PT group. Conclusions: When we compared with PT, PRP seemed to be a well-tolerated application which showed promising results in patients with chronic partial supraspinatus tears. PMID:26473076

In vivo clinical and radiological effects of platelet-rich plasma on interstitial supraspinatus lesion: Case series.

PubMed

Lädermann, A; Zumstein, M A; Kolo, F C; Grosclaude, M; Koglin, L; Schwitzguebel, A J P

2016-12-01

Rotator cuff tear (RCT) is a frequent condition of clinical relevance that can be managed with a symptomatic conservative treatment, but surgery is often needed. Biological components like leukocytes and platelet rich plasma (L-PRP) could represent an alternative curative method for interstitial RCT. It has been hypothesized that an ultrasound guided L-PRP injection in supraspinatus interstitial RCT could induce radiological healing. A prospective case series including 25 patients was performed in order to assess the effect of L-PRP infiltration into supraspinatus interstitial RCTs. Primary outcome was tear size change determined by magnetic resonance imaging arthrogram (MRA) before and 6 months after L-PRP infiltration. Secondary outcomes were Constant score, SANE score, and pain visual analog scale (VAS) after L-PRP infiltration. Tear volume diminution was statistically significant (P=.007), and a >50% tear volume diminution was observed in 15 patients. A statistically significant improvement of Constant score (P<.001), SANE score (P=.001), and VAS (P<.001) was observed. In 21 patients, Constant score improvement reached the minimal clinical important difference of 10.4 points. We observed a statistically significant and clinically relevant effect on RCT size and clinical parameters after L-PRP infiltration. Such an important improvement of supraspinatus interstitial RCT with conservative management is uncommon, therefore intratendinous L-PRP infiltrations could have been beneficial. This encouraging result could pave the way for future randomized studies in order to formally determinate whether L-PRP infiltrations are a possible alternative to surgical treatment of interstitial RCT. Prospective observational study; Level of evidence II. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Toll like receptors TLR1/2, TLR6 and MUC5B as binding interaction partners with cytostatic proline rich polypeptide 1 in human chondrosarcoma

PubMed Central

Galoian, Karina; Abrahamyan, Silva; Chailyan, Gor; Qureshi, Amir; Patel, Parthik; Metser, Gil; Moran, Alexandra; Sahakyan, Inesa; Tumasyan, Narine; Lee, Albert; Davtyan, Tigran; Chailyan, Samvel; Galoyan, Armen

2018-01-01

Metastatic chondrosarcoma is a bone malignancy not responsive to conventional therapies; new approaches and therapies are urgently needed. We have previously reported that mTORC1 inhibitor, antitumorigenic cytostatic proline rich polypeptide 1 (PRP-1), galarmin caused a significant upregulation of tumor suppressors including TET1/2 and SOCS3 (known to be involved in inflammatory processes), downregulation of oncoproteins and embryonic stem cell marker miR-302C and its targets Nanog, c-Myc and Bmi-1 in human chondrosarcoma. To understand better the mechanism of PRP-1 action it was very important to identify the receptor it binds to. Nuclear pathway receptor and GPCR assays indicated that PRP-1 receptors are not G protein coupled, neither do they belong to family of nuclear or orphan receptors. In the present study, we have demonstrated that PRP-1 binding interacting partners belong to innate immunity pattern recognition toll like receptors TLR1/2 and TLR6 and gel forming secreted mucin MUC5B. MUC5B was identified as PRP-1 receptor in human chondrosarcoma JJ012 cell line using Ligand-receptor capture technology. Toll like receptors TLR1/2 and TLR6 were identified as binding interaction partners with PRP-1 by western blot analysis in human chondrosarcoma JJ012 cell line lysates. Immunocytochemistry experiments confirmed the finding and indicated the localization of PRP-1 receptors in the tumor nucleus predominantly. TLR1/2, TLR6 and MUC5B were downregulated in human chondrosarcoma and upregulated in dose-response manner upon PRP-1 treatment. Experimental data indicated that in this cellular context the mentioned receptors had tumor suppressive function. PMID:29138803

Prevalence of periradicular periodontitis in a Scottish subpopulation found on CBCT images.

PubMed

Dutta, A; Smith-Jack, F; Saunders, W P

2014-09-01

To investigate the prevalence of periradicular periodontitis (PRP) using cone-beam computed tomography (CBCT) scans in a retrospective cross-sectional epidemiological study in a Scottish subpopulation. Of the 319 CBCT scans performed at Dundee Dental Hospital between November 2009 and July 2012, 245 dentate scans of patients over 18 years of age were included and 3595 teeth examined. Odds ratios were calculated, and the association between root filling and posts with PRP was determined. Radiological signs of PRP were detected in 209 teeth (5.8%) in 96 patients (male = 53, female = 43) of which 145 (69.4%) were measurable and 64 (30.6%) appeared as periapical widening. Most lesions were seen in the 46-55-year age group and in maxillary anterior teeth (35.4%); 47.4% (n = 81) of the total root filled teeth (n = 171) had PRP. Of the root filled teeth with lesions, approximately half (50.6%) had an inadequate root filling. Teeth with crowns, but not root filled, accounted for 17.7% of PRP. Periapical changes were detected on a high proportion of teeth with post-retained crowns (70.7%). The presence of a root filling was significantly associated with PRP (z = 17.689 P < 0.0001; odds ratio 16.36 < 23.17 < 32.83, 95% CI) and the presence of a post (z = 10.901 P < 0.0001; odds ratio 21.36 < 41.8021 < 81.78, 95% CI). The prevalence of PRP in a Scottish subpopulation was 5.8%. The presence of a root filling or a post-retained crown was significantly associated with the presence of PRP as determined by CBCT scans. The prevalence of periradicular disease in root filled teeth remains high in the Scottish population. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Ultrasound-Guided Intratendinous Injections With Platelet-Rich Plasma or Autologous Whole Blood for Treatment of Proximal Hamstring Tendinopathy: A Double-Blind Randomized Controlled Trial.

PubMed

Davenport, Kathleen L; Campos, Jose Santiago; Nguyen, Joseph; Saboeiro, Gregory; Adler, Ronald S; Moley, Peter J

2015-08-01

To compare the effects of ultrasound-guided platelet-rich plasma (PRP) and whole blood (WB) injections in patients with chronic hamstring tendinopathy. In a prospective double-blind randomized controlled trial, PRP or WB was injected under ultrasound guidance into the proximal hamstring tendon in a cohort of patients with clinically suspected hamstring tendinosis. Questionnaires were administered before injection and 2, 6, and 12 weeks and 6 months after injection. Pain and function outcomes were measured via the Modified Harris Hip Score (MHHS), Hip Outcome Scores for activities of daily living (ADL) and sport-specific function, and International Hip Outcome Tool 33 (IHOT-33). Diagnostic ultrasound was used to compare preinjection and 6-month postinjection tendon appearances. The WB group showed greater improvements in pain and function over the PRP group before 12 weeks, whereas the PRP group showed improved outcomes over WB at 6 months. None of these between-group outcome measures, except 6-week IHOT-33, showed statistical significance. Comparing preinjection and 6-month scores, the PRP group showed significant improvements in ADL (P = .018) and IHOT-33 (P = .28) scores, whereas the WB group showed no significant improvements from baseline. The WB group showed significantly decreased pain with 15-minute sitting (P= .008) at 6 months. Ultrasound imaging showed no significant differences between PRP and WB group tendon appearances. Both PRP and WB groups showed improvements in all outcome measures at 6 months. The PRP group showed significant improvements in 6-month ADL and IHOT-33 scores. The WB group reached significance in 15-minute sitting pain. No significant between-group differences were observed at any time point. © 2015 by the American Institute of Ultrasound in Medicine.

Expansion of the octarepeat domain alters the misfolding pathway but not the folding pathway of the prion protein.

PubMed

Leliveld, S Rutger; Stitz, Lothar; Korth, Carsten

2008-06-10

A misfolded conformation of the prion protein (PrP), PrP (Sc), is the essential component of prions, the infectious agents that cause transmissible neurodegenerative diseases. Insertional mutations that lead to an increase in the number of octarepeats (ORs) in PrP are linked to familial human prion disease. In this study, we investigated how expansion of the OR domain causes PrP to favor a prion-like conformation. Therefore, we compared the conformational and aggregation modulating properties of wild-type versus expanded OR domains, either as a fusion construct with the protein G B1 domain (GB1-OR) or as an integral part of full-length mouse PrP (MoPrP). Using circular dichroism spectroscopy, we first demonstrated that ORs are not unfolded but exist as an ensemble of three distinct conformers: polyproline helix-like, beta-turn, and "Trp-related". Domain expansion had little effect on the conformation of GB1-OR fusion proteins. When part of MoPrP however, OR domain expansion changed PrP's folding landscape, not by hampering the production of native alpha-helical monomers but by greatly reducing the propensity to form amyloid and by altering the assembly of misfolded, beta-rich aggregates. These features may relate to subtle pH-dependent conformational differences between wild-type and mutant monomers. In conclusion, we propose that PrP insertional mutations are pathogenic because they enhance specific misfolding pathways of PrP rather than by undermining native folding. This idea was supported by a trial bioassay in transgenic mice overexpressing wild-type MoPrP, where intracerebral injection of recombinant MoPrP with an expanded OR domain but not wild-type MoPrP caused prion disease.

Markedly Increased Susceptibility to Natural Sheep Scrapie of Transgenic Mice Expressing Ovine PrP

PubMed Central

Vilotte, Jean-Luc; Soulier, Solange; Essalmani, Rachid; Stinnakre, Marie-George; Vaiman, Daniel; Lepourry, Laurence; Da Silva, Jose Costa; Besnard, Nathalie; Dawson, Mike; Buschmann, Anne; Groschup, Martin; Petit, Stephanie; Madelaine, Marie-Francoise; Rakatobe, Sabine; Le Dur, Annick; Vilette, Didier; Laude, Hubert

2001-01-01

The susceptibility of sheep to scrapie is known to involve, as a major determinant, the nature of the prion protein (PrP) allele, with the VRQ allele conferring the highest susceptibility to the disease. Transgenic mice expressing in their brains three different ovine PrPVRQ-encoding transgenes under an endogenous PrP-deficient genetic background were established. Nine transgenic (tgOv) lines were selected and challenged with two scrapie field isolates derived from VRQ-homozygous affected sheep. All inoculated mice developed neurological signs associated with a transmissible spongiform encephalopathy (TSE) disease and accumulated a protease-resistant form of PrP (PrPres) in their brains. The incubation duration appeared to be inversely related to the PrP steady-state level in the brain, irrespective of the transgene construct. The survival time for animals from the line expressing the highest level of PrP was reduced by at least 1 year compared to those of two groups of conventional mice. With one isolate, the duration of incubation was as short as 2 months, which is comparable to that observed for the rodent TSE models with the briefest survival times. No survival time reduction was observed upon subpassaging of either isolate, suggesting no need for adaptation of the agent to its new host. Overexpression of the transgene was found not to be required for transmission to be accelerated compared to that observed with wild-type mice. Conversely, transgenic mice overexpressing murine PrP were found to be less susceptible than tgOv lines expressing ovine PrP at physiological levels. These data argue that ovine PrPVRQ provided a better substrate for sheep prion replication than did mouse PrP. Altogether, these tgOv mice could be an improved model for experimental studies on natural sheep scrapie. PMID:11390599

A conceptual study on the formulation of a permeable reactive pavement with activated carbon additives for controlling the fate of non-point source environmental organic contaminants.

PubMed

Huang, Shengyi; Liang, Chenju

2018-02-01

To take advantage of the road pavement network where non-point source (NPS) pollution such as benzene, toluene, ethyl-benzene, and xylene (BTEX) from vehicle traffic exhaust via wet and dry atmospheric deposition occurs, the asphalt pavement may be used as a media to control the NPS pollution. An experiment to prepare an adsorptive porous reactive pavement (PRP) was initiated to explore the potential to reduce environmental NPS vehicle pollution. The PRP was prepared and studied as follows: various activated carbons (AC) were initially screened to determine if they were suitable as an additive in the porous asphalt mixture; various mixtures of a selected AC were incorporated with the design of porous asphalt concrete (PAC) to produce PRP, and the PRP formulations were tested to ensure that they comply with the required specifications; qualified specimens were subsequently tested to determine their adsorption capacity for BTEX in aqueous solution, as compared to conventional PAC. The PRP08 and PRP16 samples, named for the design formulations of 0.8% and 1.6% of AC (by wt. in the formulation), exhibited low asphalt drain-down and low abrasion loss and also met all regulated specifications. The BTEX adsorption capacity measurements of PRP08 and PRP16 were 33-46%, 36-51%, 20-22%, and 6-8% respectively, higher than those obtained from PACs. Based on the test results, PRPs showed good physical performance and adsorption and may be considered as a potential method for controlling the transport of NPS vehicle pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Platelet‑rich plasma promotes the migration and invasion of synovial fibroblasts in patients with rheumatoid arthritis.

PubMed

Yan, Shanshan; Yang, Binzhou; Shang, Chen; Ma, Zhongshuang; Tang, Zizheng; Liu, Guiping; Shen, Weigan; Zhang, Yu

2016-09-01

Platelet-rich plasma (PRP) is blood plasma that has been enriched with platelets, and the number of platelets is correlated with rheumatoid activity. PRP is a concentrated source of autologous platelets, and contains several different growth factors and cytokines, including platelet‑derived growth factor, transforming growth factor‑β and insulin‑like growth factor‑1, which stimulate healing of bone and soft tissue. Rheumatoid arthritis (RA) is characterized by synovial hyperplasia, cell activation, articular inflammation and invasion of the synovium into the adjacent bone and cartilage. The adhesion of fibroblast‑like synoviocytes (FLSs) onto the extracellular matrix (ECM), migration and invasion are important for the erosion and destruction of the articular cartilage of patients with RA. The aim of the present study was to investigate the effects of PRP on the adhesion, migration and invasion of RA‑FLSs. Scratch and Transwell migration assays determined that PRP at a concentration of 2 and 5% significantly enhanced the migration ability of RA‑FLSs. Treatment of RA‑FLSs with 2 and 5% PRP promoted the adhesion and invasion of the cells. Additionally, the immunofluorescence assay revealed that PRP induced a decrease in the number of centrally located stress fibers and led to an increase in the formation of filopodia and lamellipodia in the detectable leading edge protrusions in RA‑FLSs. In addition, reverse transcription‑quantitative polymerase chain reaction and western blot analysis determined that PRP upregulated the protein and mRNA expression levels of matrix metalloproteinase‑1 (MMP‑1). In conclusion, the promotion of RA‑FLS cell migration, invasion and adhesion on the ECM by PRP may be modulated through the upregulation of MMP‑1 expression and the induction of actin cytoskeletal reorganization.

Preparation and testing of a Haemophilus influenzae Type b/Hepatitis B surface antigen conjugate vaccine.

PubMed

An, So Jung; Woo, Joo Sung; Chae, Myung Hwa; Kothari, Sudeep; Carbis, Rodney

2015-03-24

The majority of conjugate vaccines focus on inducing an antibody response to the polysaccharide antigen and the carrier protein is present primarily to induce a T-cell dependent response. In this study conjugates consisting of poly(ribosylribitolphosphate) (PRP) purified from Haemophilus influenzae Type b bound to Hepatitis B virus surface antigen (HBsAg) virus like particles were prepared with the aim of inducing an antibody response to not only the PRP but also the HBsAg. A conjugate consisting of PRP bound to HBsAg via an adipic acid dihydrazide (ADH) spacer induced strong IgG antibodies to both the PRP and HBsAg. When conjugation was performed without the ADH spacer the induction of an anti-PRP response was equivalent to that seen by conjugate with the ADH spacer, however, a negligible anti-HBsAg response was induced. For comparison, PRP was conjugated to diphtheria toxoid (DT) and Vi polysaccharide purified from Salmonella Typhi conjugated to HBsAg both using an ADH spacer. The PRPAH-DT conjugate induced strong anti-PRP and anti-DT responses, the Vi-AHHBsAg conjugate induced a good anti-HBsAg response but not as strong as that induced by the PRPAH-HBsAg conjugate. This study demonstrated that in mice it was possible to induce robust antibody responses to both polysaccharide and carrier protein provided the conjugate has certain physico-chemical properties. A PRPAH-HBsAg conjugate with the capacity to induce anti-PRP and anti-HBsAg responses could be incorporated into a multivalent pediatric vaccine and simplify formulation of such a vaccine. Copyright © 2015 Elsevier Ltd. All rights reserved.

Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review.

PubMed

Delimont, Nicole M; Rosenkranz, Sara K; Haub, Mark D; Lindshield, Brian L

2017-01-01

Tannins are often cited for antinutritional effects, including chelation of non-heme iron. Despite this, studies exploring non-heme iron bioavailability inhibition with long-term consumption have reported mixed results. Salivary proline-rich proteins (PRPs) may mediate tannin-antinutritional effects on non-heme iron bioavailability. To review evidence regarding biochemical binding mechanisms and affinity states between PRPs and tannins, as well as effects of PRPs on non-heme iron bioavailability with tannin consumption in vivo. Narrative systematic review and meta-analysis. Common themes in biochemical modeling and affinity studies were collated for summary and synthesis; data were extracted from in vivo experiments for meta-analysis. Thirty-two studies were included in analysis. Common themes that positively influenced tannin-PRP binding included specificity of tannin-PRP binding, PRP and tannin stereochemistry. Hydrolyzable tannins have different affinities than condensed tannins when binding to PRPs. In vivo, hepatic iron stores and non-heme iron absorption are not significantly affected by tannin consumption ( d  = -0.64-1.84; -2.7-0.13 respectively), and PRP expression may increase non-heme iron bioavailability with tannin consumption. In vitro modeling suggests that tannins favor PRP binding over iron chelation throughout digestion. Hydrolyzable tannins are not representative of tannin impact on non-heme iron bioavailability in food tannins because of their unique structural properties and PRP affinities. With tannin consumption, PRP production is increased, and may be an initial line of defense against tannin-non-heme iron chelation in vivo . More research is needed to compare competitive binding of tannin-PRP to tannin-non-heme iron complexes, and elucidate PRPs' role in adaption to non-heme iron bioavailability in vivo.

Platelet-Rich Plasma Injection in Burn Scar Areas Alleviates Neuropathic Scar Pain

PubMed Central

Huang, Shu-Hung; Wu, Sheng-Hua; Lee, Su-Shin; Lin, Yun-Nan; Chai, Chee-Yin; Lai, Chung-Sheng; Wang, Hui-Min David

2018-01-01

Objective: No effective treatments have yet been developed for burn-induced neuropathic pain. Platelet-rich plasma (PRP) has been reported to ameliorate various types of inflammation pain. However, the effect of PRP on burn-induced neuropathic pain is unclear. Methods: Burn-induced neuropathic pain Sprague-Dawley rat model was confirmed using a mechanical response test 4 weeks after the burn injuries were sustained, following which PRP was injected in the scar area. The rats were divided into four groups (n = 6) as following: Group A, Sham; Group B, Sham + PRP; Group C, Burn; and Group D, Burn + PRP. Four weeks after the PRP injection, the animals were subjected to behavior tests and then sacrificed; specimens were collected for inflammation tests, Masson's trichrome stain and chromosome 10 (PTEN) in the injured skin; and PTEN, phosphorylated mammalian target of rapamycin (p-mTOR), p38, nuclear factor κB (NFκB), chemokine (CC motif) ligand 2 (CCL2), and CCL2 cognate receptor (CCR2) in spinal cord dorsal horns through immunohistochemistry and immunofluorescence staining. Results: PRP significantly alleviated allodynia in burn-induced neuropathic pain 4 weeks after treatment, and PTEN expression in the skin and spinal cord were significantly increased in group D compared with the group C. p-PTEN, p-mTOR, and CCL2 expression in neuron cells; p-p38 and p-NFκB expression in microglia; and p-JNK and p-NFκB activation in spinal astrocytes decreased significantly in the group D compared with the group C. Conclusions: PRP is effective in treating burn-induced neuropathic pain and may be used in clinical practice. PMID:29483815

Approaches to and Treatment Strategies for Playing-Related Pain Problems Among Czech Instrumental Music Students: An Epidemiological Study.

PubMed

Ioannou, Christos I; Altenmüller, Eckart

2015-09-01

The current study examined the severity of playing-related pain (PRP) problems among music students at the Prague State Conservatoire, as well as the various treatment methods used by these students and how they approach and deal with these phenomena while studying. In total, 180 instrumental students participated and completed a paper questionnaire. Of these, 88.9% reported that they had experienced PRP at least once in their lives, with 12.6% experiencing pain every time they play. The onset of PRP seemed to coincide with the transition period on entry to the conservatoire and was associated with the increase in hours of practice. Specific body regions associated with playing each particular instrument were most frequently affected, with females being more susceptible than males to the development of PRP. An alarming 35% of the affected students tended not to seek help at all, whereas those who did tended to seek advice first from their instrument tutor and second from medical doctors. Most students who visited doctors reported that medical treatments only partially helped them to overcome PRP problems. The most frequent treatment methods used were resting, gel or creams, and physical exercises. Students believed that inappropriate posture played a key role in the development of their PRP problems. Finally, students indicated a willingness to be aware of and educated about PRP issues during their studies. Further exploration of PRP problems among student musicians is warranted. Better understanding of differing attitudes toward, use of, and efficiency of various treatment methods after the occurrence of PRPs will provide additional insight for prevention and treatment.

Periodontal tissue regeneration by combined implantation of adipose tissue-derived stem cells and platelet-rich plasma in a canine model.

PubMed

Tobita, Morikuni; Uysal, Cagri A; Guo, Xin; Hyakusoku, Hiko; Mizuno, Hiroshi

2013-12-01

One goal of periodontal therapy is to regenerate periodontal tissues. Stem cells, growth factors and scaffolds and biomaterials are vital for the restoration of the architecture and function of complex tissues. Adipose tissue-derived stem cells (ASCs) are an ideal population of stem cells for practical regenerative medicine. In addition, platelet-rich plasma (PRP) can be useful for its ability to stimulate tissue regeneration. PRP contains various growth factors and may be useful as a cell carrier in stem cell therapies. The purpose of this study was to determine whether a mixture of ASCs and PRP promoted periodontal tissue regeneration in a canine model. Autologous ASCs and PRP were implanted into areas with periodontal tissue defects. Periodontal tissue defects that received PRP alone or non-implantation were also examined. Histologic, immunohistologic and x-ray studies were performed 1 or 2 months after implantation. The amount of newly formed bone and the scale of newly formed cementum in the region of the periodontal tissue defect were analyzed on tissue sections. The areas of newly formed bone and cementum were greater 2 months after implantation of ASCs and PRP than at 1 month after implantation, and the radiopacity in the region of the periodontal tissue defect increased markedly by 2 months after implantation. The ASCs and PRP group exhibited periodontal tissue with the correct architecture, including alveolar bone, cementum-like structures and periodontal ligament-like structures, by 2 months after implantation. These findings suggest that a combination of autologous ASCs and PRP promotes periodontal tissue regeneration that develops the appropriate architecture for this complex tissue. Copyright © 2013 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Platelet-rich plasma in tendon-related disorders: results and indications.

PubMed

Filardo, Giuseppe; Di Matteo, Berardo; Kon, Elizaveta; Merli, Giulia; Marcacci, Maurilio

2016-09-24

Platelet-rich plasma (PRP) is currently the most exploited strategy in the clinical practice to provide a regenerative stimulus for tendon healing. The aim of the present study was to systematically review the available evidence on the treatment of the main tendon disorders where PRP is currently applied. A systematic review of the literature was performed on the use of PRP as a treatment for tendinopathies focusing on the following sites: Achilles tendon, patellar tendon, rotator cuff tendons, and lateral elbow tendons. The following inclusion criteria for relevant articles were used: clinical trials written in English language up to 21 June 2016 on the use of PRP in the conservative or surgical treatment of the aforementioned tendinopathies. The research identified the following clinical trials dealing with the application of PRP in the selected tendons: 19 papers on patellar tendon (6 being RCTs: 4 dealing with PRP conservative application and 2 surgical), 24 papers on Achilles tendon (4 RCTs: 3 conservative and 1 surgical), 29 on lateral elbow tendons (17 RCTs, all conservative), and 32 on rotator cuff (22 RCTs: 18 surgical and 3 conservative). Patellar tendons seem to benefit from PRP injections, whereas in the Achilles tendon, PRP application is not indicated neither as a conservative approach nor as a surgical augmentation. Lateral elbow tendinopathy showed an improvement in most of the high-level studies, but the lack of proven superiority with respect to the more simple whole-blood injections still questions its use in the clinical practice. With regard to rotator cuff pathology, the vast majority of surgical RCTs documented a lack of beneficial effects, whereas there is still inconclusive evidence concerning its conservative application in rotator cuff disorders. Systematic review of level I-IV trials, Level IV.

Effect of platelet-rich plasma on polypropylene meshes implanted in the rabbit vagina: histological analysis.

PubMed

Parizzi, Natália Gomes; Rubini, Oscar Ávila; Almeida, Silvio Henrique Maia de; Ireno, Lais Caetano; Tashiro, Roger Mitio; Carvalho, Victor Hugo Tolotto de

2017-01-01

The polypropylene mesh (PPM) is used in many surgical interventions because of its good incorporation and accessibility. However, potential mesh-related complications are common. Platelet-rich plasma (PRP) improves the healing of wounds and is inexpensive. Thus, the purpose of this study was to analyze the effect of the PRP-gel coating of a PPM on inflammation, production of collagen, and smooth muscle in the rabbit vagina. The intervention consisted of a 1.5cm incision and divulsion of the vaginal mucosa for the implantation of a PRP-coated PPM. The PRP-coated mesh was implanted in 15 rabbits, and in the second group, the same implant was used without the PRP coating. In the sham group, the intervention consisted of the incision, divulsion, and suture. The rabbits were euthanized at 7, 30 and 90 days, and full-thickness sagittal sections of the posterior vaginal wall and rectum were scored. The inflammatory infiltrate was evaluated using hematoxylin and eosin staining. The Sirius Red stain was used to examine deposition of collagen I and III, and Masson's trichrome staining was used to visualize the smooth muscle. The group with PRP-coated meshes had a lower inflammatory infiltrate count at 30 days. Deposition of collagen III increased with the use of PRP-coating at 90 days. The area of inflammatory infiltrate was significantly increased in the group without the PRP-coated mesh at 30 days but not in the group with the PRPcoated mesh, indicating a less intense inflammatory response. In addition, a significant increase in collagen III occurred at 90 days. Copyright® by the International Brazilian Journal of Urology.

A Meta-Analytic Review of the Penn Resiliency Program’s Effect on Depressive Symptoms

PubMed Central

Brunwasser, Steven M.; Gillham, Jane E.; Kim, Eric S.

2015-01-01

Objectives The purpose of this review was to evaluate whether the Penn Resiliency Program (PRP), a group cognitive-behavioral intervention, is effective in targeting depressive symptoms in youth. Data sources We identified 17 controlled evaluations of PRP (N = 2498) measuring depressive symptoms via an online search of PsycInfo, Medline, ERIC, and ProQuest Dissertations and Theses, and by requesting data from PRP researchers. Review methods We combined effect sizes (ESs; Glass’s d), using random effects models at post-intervention and two follow-up assessments. Results PRP participants reported fewer depressive symptoms at post-intervention and both follow-up assessments compared to youth receiving no intervention, with ESs ranging from 0.11 to 0.21. Limited data show no evidence that PRP is superior to active control conditions. Subgroup analyses showed that PRP’s effects were significant at 1 or more follow-up assessments among studies using both targeted and universal approaches, when group leaders were research team members and community providers, among participants with both low and elevated baseline symptoms, and among boys and girls. Preliminary analyses suggest that PRP’s effects on depressive disorders may be smaller than those reported in a larger meta-analysis of depression prevention programs for older adolescents and adults. Conclusion We found evidence that PRP significantly reduces depressive symptoms through at least 1 year post-intervention. Future PRP research should examine whether PRP’s effects on depressive symptoms lead to clinically meaningful benefits for its participants, whether the program is cost-effective, whether CBT skills mediate program effects, and whether PRP is effective when delivered under real-world conditions. PMID:19968381

Decomposing Sources of Response Slowing in the PRP Paradigm

ERIC Educational Resources Information Center

Jentzsch, Ines; Leuthold, Hartmut; Ulrich, Rolf

2007-01-01

The mechanism underlying the reaction time (RT2) slowing to the 2nd of 2 successively presented stimuli (S1 and S2) in the psychological refractory period paradigm was investigated. Stimulus onset synchrony (SOA) between S1 and S2, contrast of S2, and Task 2 set-level compatibility was manipulated. Specifically, the authors used a…

PrPC Undergoes Basal to Apical Transcytosis in Polarized Epithelial MDCK Cells

PubMed Central

Arkhipenko, Alexander; Syan, Sylvie; Victoria, Guiliana Soraya

2016-01-01

The Prion Protein (PrP) is an ubiquitously expressed glycosylated membrane protein attached to the external leaflet of the plasma membrane via a glycosylphosphatidylinositol anchor (GPI). While the misfolded PrPSc scrapie isoform is the infectious agent of prion disease, the cellular isoform (PrPC) is an enigmatic protein with unclear function. Of interest, PrP localization in polarized MDCK cells is controversial and its mechanism of trafficking is not clear. Here we investigated PrP traffic in MDCK cells polarized on filters and in three-dimensional MDCK cysts, a more physiological model of polarized epithelia. We found that, unlike other GPI-anchored proteins (GPI-APs), PrP undergoes basolateral-to-apical transcytosis in fully polarized MDCK cells. Following this event full-length PrP and its cleavage fragments are segregated in different domains of the plasma membrane in polarized cells in both 2D and 3D cultures. PMID:27389581

Classification of platelet concentrates: from pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF).

PubMed

Dohan Ehrenfest, David M; Rasmusson, Lars; Albrektsson, Tomas

2009-03-01

The topical use of platelet concentrates is recent and its efficiency remains controversial. Several techniques for platelet concentrates are available; however, their applications have been confusing because each method leads to a different product with different biology and potential uses. Here, we present classification of the different platelet concentrates into four categories, depending on their leucocyte and fibrin content: pure platelet-rich plasma (P-PRP), such as cell separator PRP, Vivostat PRF or Anitua's PRGF; leucocyte- and platelet-rich plasma (L-PRP), such as Curasan, Regen, Plateltex, SmartPReP, PCCS, Magellan or GPS PRP; pure plaletet-rich fibrin (P-PRF), such as Fibrinet; and leucocyte- and platelet-rich fibrin (L-PRF), such as Choukroun's PRF. This classification should help to elucidate successes and failures that have occurred so far, as well as providing an objective approach for the further development of these techniques.

Intradiscal platelet-rich plasma (PRP) injections for discogenic low back pain: an update.

PubMed

Monfett, Michael; Harrison, Julian; Boachie-Adjei, Kwadwo; Lutz, Gregory

2016-06-01

The aim of this article is to provide an overview of clinical and translational research on intradiscal platelet-rich plasma (PRP) as a minimally invasive treatment for discogenic low back pain. A literature review of in vitro, in vivo, and clinical studies was performed. There is strong in vitro evidence that supports the use of intradiscal PRP for discogenic low back pain. There are also promising findings in select preclinical animal studies. A clinical study of 29 participants who underwent intradiscal PRP injections for discogenic low back pain found statistically and clinically significant improvements in pain and function through two years of follow-up. Intradiscal PRP is a safe and a possibly effective treatment for discogenic low back pain. Future studies are warranted to determine the best candidates for this treatment, what the optimal injectate is and what relationships exist between patient-reported outcomes and radiological findings.

Contributions for classification of platelet rich plasma - proposal of a new classification: MARSPILL.

PubMed

Lana, Jose Fabio Santos Duarte; Purita, Joseph; Paulus, Christian; Huber, Stephany Cares; Rodrigues, Bruno Lima; Rodrigues, Ana Amélia; Santana, Maria Helena; Madureira, João Lopo; Malheiros Luzo, Ângela Cristina; Belangero, William Dias; Annichino-Bizzacchi, Joyce Maria

2017-07-01

Platelet-rich plasma (PRP) has emerged as a significant therapy used in medical conditions with heterogeneous results. There are some important classifications to try to standardize the PRP procedure. The aim of this report is to describe PRP contents studying celular and molecular components, and also propose a new classification for PRP. The main focus is on mononuclear cells, which comprise progenitor cells and monocytes. In addition, there are important variables related to PRP application incorporated in this study, which are the harvest method, activation, red blood cells, number of spins, image guidance, leukocytes number and light activation. The other focus is the discussion about progenitor cells presence on peripherial blood which are interesting due to neovasculogenesis and proliferation. The function of monocytes (in tissue-macrophages) are discussed here and also its plasticity, a potential property for regenerative medicine treatments.

The use of autologous blood-derived growth factors in bone regeneration

PubMed Central

Civinini, Roberto; Macera, Armando; Nistri, Lorenzo; Redl, Birgit; Innocenti, Massimo

2011-01-01

Platelet-rich plasma (PRP) is defined as a portion of the plasma fraction of autologous blood having platelet concentrations above baseline. When activated the platelets release growth factors that play an essential role in bone healing such as Platelet-derived Growth Factor, Transforming Growth Factor-β, Vascular Endothelial Growth Factor and others. Multiple basic science and in vivo animal studies agree that PRP has a role in the stimulation of the healing cascade in ligament, tendon, muscle cartilage and in bone regeneration in the last years PRP had a widespread diffusion in the treatment of soft tissue and bone healing. The purpose of this review is to describe the biological properties of platelets and its factors, the methods used for producing PRP, to provide a background on the underlying basic science and an overview of evidence based medicine on clinical application of PRP in bone healing. PMID:22461800

The Clinical Efficacy of Autologous Platelet-Rich Plasma Combined with Ultra-Pulsed Fractional CO2 Laser Therapy for Facial Rejuvenation

PubMed Central

Hui, Qiang; Chang, Peng; Guo, Bingyu; Zhang, Yu

2017-01-01

Abstract Ultra-pulsed fractional CO2 laser is an efficient, precise, and safe therapeutic intervention for skin refreshing, although accompanied with prolonged edema and erythema. In recent years, autologous platelet-rich plasma (PRP) has been proven to promote wound and soft tissue healing and collagen regeneration. To investigate whether the combination of PRP and ultra-pulsed fractional CO2 laser had a synergistic effect on therapy for facial rejuvenation. Totally, 13 facial aging females were treated with ultra-pulsed fractional CO2 laser. One side of the face was randomly selected as experimental group and injected with PRP, the other side acted as the control group and was injected with physiological saline at the same dose. Comprehensive assessment of clinical efficacy was performed by satisfaction scores, dermatologists' double-blind evaluation and the VISIA skin analysis system. After treatment for 3 months, subjective scores of facial wrinkles, skin texture, and skin elasticity were higher than that in the control group. Similarly, improvement of skin wrinkles, texture, and tightness in the experimental group was better compared with the control group. Additionally, the total duration of erythema, edema, and crusting was decreased, in the experimental group compared with the control group. PRP combined with ultra-pulsed fractional CO2 laser had a synergistic effect on facial rejuvenation, shortening duration of side effects, and promoting better therapeutic effect. PMID:27222038

Treatment of chronic non-healing ulcers using autologous platelet rich plasma: a case series.

PubMed

Suthar, Manish; Gupta, Saniya; Bukhari, Suhail; Ponemone, Venkatesh

2017-02-27

Non-healing ulcers are a major health problem worldwide and have great impact at personal, professional and social levels, with high cost in terms of human and material resources. Recalcitrant non-healing ulcers are inevitable and detrimental to the lower limb and are a major cause of non-traumatic lower limb amputations. Application of autologous Platelet Rich Plasma (PRP) has been a major breakthrough for the treatment of non-healing and diabetic foot ulcers, as it is an easy and cost-effective method, and provides the necessary growth factors that enhance tissue healing. PRP is a conglomeration of thrombocytes, cytokines and various growth factors which are secreted by α-granules of platelets that augment the rate of natural healing process with decrease in time. The purpose of this case series was to evaluate the safety and efficacy of autologous platelet rich plasma for the treatment of chronic non-healing ulcers on the lower extremity. Autologous PRP was prepared from whole blood utilizing a rapid, intraoperative point-of-care system that works on the principle of density gradient centrifugation. Twenty Four (24) patients with non-healing ulcers of different etiologies, who met the inclusion criteria, were treated with single dose of subcutaneous PRP injections along with topical application of PRP gel under compassionate use. The mean age of the treated patients was 62.5 ± 13.53 years and they were followed-up for a period of 24 weeks. All the patients showed signs of wound healing with reduction in wound size, and the mean time duration to ulcer healing was 8.2 weeks. Also, an average five fold increase in the platelet concentrate was observed in the final PRP product obtained using the rapid point-of-care device, and the average platelet dose administered to the patients was 70.10 × 10 8 . This case series has demonstrated the potential safety and efficacy of autologous platelet rich plasma for the treatment of chronic non-healing ulcers. NCT03026855 , Registered 4 January 2017 'Retrospectively'.

Participation in Research Program: A Novel Course in Undergraduate Education of Life Science

ERIC Educational Resources Information Center

Zhou, Xuanwei; Lin, Juan; Yin, Yizhou; Sun, Xiaofen; Tang, Kexuan

2007-01-01

A novel course, "Participation in Research Program (PRP)" in life sciences is open for 1st to 3rd year undergraduates. PRP introduces the principles of a variety of biological methods and techniques and also offers an opportunity to explore some specific knowledge in more detail prior to thesis research. In addition, the PRP introduces some…

Polymorphisms and variants in the prion protein sequence of European moose (Alces alces), reindeer (Rangifer tarandus), roe deer (Capreolus capreolus) and fallow deer (Dama dama) in Scandinavia

PubMed Central

Wik, Lotta; Mikko, Sofia; Klingeborn, Mikael; Stéen, Margareta; Simonsson, Magnus; Linné, Tommy

2012-01-01

The prion protein (PrP) sequence of European moose, reindeer, roe deer and fallow deer in Scandinavia has high homology to the PrP sequence of North American cervids. Variants in the European moose PrP sequence were found at amino acid position 109 as K or Q. The 109Q variant is unique in the PrP sequence of vertebrates. During the 1980s a wasting syndrome in Swedish moose, Moose Wasting Syndrome (MWS), was described. SNP analysis demonstrated a difference in the observed genotype proportions of the heterozygous Q/K and homozygous Q/Q variants in the MWS animals compared with the healthy animals. In MWS moose the allele frequencies for 109K and 109Q were 0.73 and 0.27, respectively, and for healthy animals 0.69 and 0.31. Both alleles were seen as heterozygotes and homozygotes. In reindeer, PrP sequence variation was demonstrated at codon 176 as D or N and codon 225 as S or Y. The PrP sequences in roe deer and fallow deer were identical with published GenBank sequences. PMID:22441661

Better dual-task processing in simultaneous interpreters

PubMed Central

Strobach, Tilo; Becker, Maxi; Schubert, Torsten; Kühn, Simone

2015-01-01

Simultaneous interpreting (SI) is a highly complex activity and requires the performance and coordination of multiple, simultaneous tasks: analysis and understanding of the discourse in a first language, reformulating linguistic material, storing of intermediate processing steps, and language production in a second language among others. It is, however, an open issue whether persons with experience in SI possess superior skills in coordination of multiple tasks and whether they are able to transfer these skills to lab-based dual-task situations. Within the present study, we set out to explore whether interpreting experience is associated with related higher-order executive functioning in the context of dual-task situations of the Psychological Refractory Period (PRP) type. In this PRP situation, we found faster reactions times in participants with experience in simultaneous interpretation in contrast to control participants without such experience. Thus, simultaneous interpreters possess superior skills in coordination of multiple tasks in lab-based dual-task situations. PMID:26528232

Viral and bacterial septicaemic infections modulate the expression of PACAP splicing variants and VIP/PACAP receptors in brown trout immune organs.

PubMed

Gorgoglione, Bartolomeo; Carpio, Yamila; Secombes, Christopher J; Taylor, Nick G H; Lugo, Juana María; Estrada, Mario Pablo

2015-12-01

Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) and PACAP-Related Peptide (PRP) are structurally similar peptides encoded in the same transcripts. Their transcription has been detected not only in the brain but also in a wide range of peripheral tissues, even including organs of the immune system. PACAP exerts pleiotropic activities through G-protein coupled membrane receptors: the PACAP-specific PAC-1 and the VPAC-1 and VPAC-2 receptors that exhibit similar affinities for the Vasoactive Intestinal Peptide (VIP) and PACAP. Recent findings added PACAP and its receptors to the growing list of mediators that allow cross-talk between the nervous, endocrine and immune systems in fish. In this study the expression of genes encoding for PACAP and PRP, as well as VIP/PACAP receptors was studied in laboratory-reared brown trout (Salmo trutta) after septicaemic infections. Respectively Viral Haemorrhagic Septicaemia Virus (VHSV-Ia) or the Gram-negative bacterium Yersinia ruckeri (ser. O1 - biot. 2) were used in infection challenges. Kidney and spleen, the teleost main lymphopoietic organs, were sampled during the first two weeks post-infection. RT-qPCR analysis assessed specific pathogens burden and gene expression levels. PACAP and PRP transcription in each organ was positively correlated to the respective pathogen burden, assessed targeting the VHSV-glycoprotein or Y. ruckeri 16S rRNA. Results showed as the transcription of PACAP splicing variants and VIP/PACAP receptors is modulated in these organs during an acute viral and bacterial septicaemic infections in brown trout. These gene expression results provide clues as to how the PACAP system is modulated in fish, confirming an involvement during active immune responses elicited by both viral and bacterial aetiological agents. However, further experimental evidence is still required to fully elucidate and characterize the role of PACAP and PRP for an efficient immune response against pathogens. Copyright © 2015 Elsevier Ltd. All rights reserved.

A light-regulated type I pilus contributes to Acinetobacter baumannii biofilm, motility and virulence functions.

PubMed

Wood, Cecily R; Ohneck, Emily J; Edelmann, Richard E; Actis, Luis A

2018-06-11

Transcriptional analyses of A. baumannii ATCC 17978 showed that the expression of A1S_2091 was enhanced in cells cultured in darkness at 24°C through a process that depended on the BlsA photoreceptor. Disruption of A1S_2091, a component of the A1S_2088-A1S_2091 polycistronic operon predicted to code for a type I chaperone/usher pilus assembly system, abolished surface motility and pellicle formation but significantly enhanced biofilm formation on plastic by bacteria cultured under darkness. Based on these observations, the A1S_2088-A1S_2091 operon was named the p hoto- r egulated p ilus ABCD ( prpABCD ) operon, with A1S_2091 coding for the PrpA pilin subunit. Unexpectedly, the comparative analyses of ATCC 17978 and prpA isogenic mutant cells cultured at 37°C showed the expression of light-regulated biofilm biogenesis and motility functions under a temperature condition that drastically affects BlsA production and its light sensing activity. These assays also suggest that 17978 cells produce alternative light-regulated adhesins and/or pili systems that enhance bacterial adhesion and biofilm formation both at 24°C and 37°C on plastic as well as on the surface of polarized A549 alveolar epithelial cells, where formation of bacterial filaments and cell chains was significantly enhanced. The inactivation of prpA also resulted in a significant reduction in virulence when tested using the Galleria mellonella virulence model. All these observations provide strong evidence showing the capacity of A. baumannii to sense light and interact with biotic and abiotic surfaces using undetermined alternative sensing and regulatory systems as well as alternative adherence and motility cellular functions that allow this pathogen to persist in different ecological niches. Copyright © 2018 American Society for Microbiology.

A B lymphocyte mitogen is a Brucella abortus virulence factor required for persistent infection

PubMed Central

Spera, Juan Manuel; Ugalde, Juan Esteban; Mucci, Juan; Comerci, Diego J.; Ugalde, Rodolfo Augusto

2006-01-01

Microbial pathogens with the ability to establish chronic infections have evolved strategies to actively modulate the host immune response. Brucellosis is a disease caused by a Gram-negative intracellular pathogen that if not treated during the initial phase of the infection becomes chronic as the bacteria persist for the lifespan of the host. How this pathogen and others achieve this action is a largely unanswered question. We report here the identification of a Brucella abortus gene (prpA) directly involved in the immune modulation of the host. PrpA belongs to the proline-racemase family and elicits a B lymphocyte polyclonal activation that depends on the integrity of its proline-racemase catalytic site. Stimulation of splenocytes with PrpA also results in IL-10 secretion. Construction of a B. abortus-prpA mutant allowed us to assess the contribution of PrpA to the infection process. Mice infected with B. abortus induced an early and transient nonresponsive status of splenocytes to both Escherichia coli LPS and ConA. This phenomenon was not observed when mice were infected with a B. abortus-prpA mutant. Moreover, the B. abortus-prpA mutant had a reduced capacity to establish a chronic infection in mice. We propose that an early and transient nonresponsive immune condition of the host mediated by this B cell polyclonal activator is required for establishing a successful chronic infection by Brucella. PMID:17053080

Reduction of pain via platelet-rich plasma in split-thickness skin graft donor sites: a series of matched pairs

PubMed Central

Miller, John D.; Rankin, Timothy M.; Hua, Natalie T.; Ontiveros, Tina; Giovinco, Nicholas A.; Mills, Joseph L.; Armstrong, David G.

2015-01-01

In the past decade, autologous platelet-rich plasma (PRP) therapy has seen increasingly widespread integration into medical specialties. PRP application is known to accelerate wound epithelialization rates, and may also reduce postoperative wound site pain. Recently, we observed an increase in patient satisfaction following PRP gel (Angel, Cytomedix, Rockville, MD) application to split-thickness skin graft (STSG) donor sites. We assessed all patients known to our university-based hospital service who underwent multiple STSGs up to the year 2014, with at least one treated with topical PRP. Based on these criteria, five patients aged 48.4±17.6 (80% male) were identified who could serve as their own control, with mean time of 4.4±5.1 years between operations. In both therapies, initial dressing changes occurred on postoperative day (POD) 7, with donor site pain measured by Likert visual pain scale. Paired t-tests compared the size and thickness of harvested skin graft and patient pain level, and STSG thickness and surface area were comparable between control and PRP interventions (p>0.05 for all). Donor site pain was reduced from an average of 7.2 (±2.6) to 3 (±3.7), an average reduction in pain of 4.2 (standard error 1.1, p=0.0098) following PRP use. Based on these results, the authors suggest PRP as a beneficial adjunct for reducing donor site pain following STSG harvest. PMID:25623477

Effects of Platelet-Rich Plasma (PRP) on a Model of Renal Ischemia-Reperfusion in Rats.

PubMed

Martín-Solé, Oriol; Rodó, Joan; García-Aparicio, Lluís; Blanch, Josep; Cusí, Victoria; Albert, Asteria

2016-01-01

Renal ischemia-reperfusion injury is a major cause of acute renal failure, causing renal cell death, a permanent decrease of renal blood flow, organ dysfunction and chronic kidney disease. Platelet-rich plasma (PRP) is an autologous product rich in growth factors, and therefore able to promote tissue regeneration and angiogenesis. This product has proven its efficacy in multiple studies, but has not yet been tested on kidney tissue. The aim of this work is to evaluate whether the application of PRP to rat kidneys undergoing ischemia-reperfusion reduces mid-term kidney damage. A total of 30 monorrenal Sprague-Dawley male rats underwent renal ischemia-reperfusion for 45 minutes. During ischemia, PRP (PRP Group, n = 15) or saline solution (SALINE Group, n = 15) was administered by subcapsular renal injection. Control kidneys were the contralateral organs removed immediately before the start of ischemia in the remaining kidneys. Survival, body weight, renal blood flow on Doppler ultrasound, kidney weight, kidney volume, blood biochemistry and histopathology were determined for all subjects and kidneys, as applicable. Correlations between these variables were searched for. The PRP Group showed significantly worse kidney blood flow (p = 0.045) and more histopathological damage (p<0.0001). Correlations were found between body weight, kidney volume, kidney weight, renal blood flow, histology, and serum levels of creatinine and urea. Our study provides the first evidence that treatment with PRP results in the deterioration of the kidney's response to ischemia-reperfusion injury.

Effects of Platelet-Rich Plasma (PRP) on a Model of Renal Ischemia-Reperfusion in Rats

PubMed Central

Martín-Solé, Oriol; Rodó, Joan; García-Aparicio, Lluís; Blanch, Josep; Cusí, Victoria; Albert, Asteria

2016-01-01

Renal ischemia-reperfusion injury is a major cause of acute renal failure, causing renal cell death, a permanent decrease of renal blood flow, organ dysfunction and chronic kidney disease. Platelet-rich plasma (PRP) is an autologous product rich in growth factors, and therefore able to promote tissue regeneration and angiogenesis. This product has proven its efficacy in multiple studies, but has not yet been tested on kidney tissue. The aim of this work is to evaluate whether the application of PRP to rat kidneys undergoing ischemia-reperfusion reduces mid-term kidney damage. A total of 30 monorrenal Sprague-Dawley male rats underwent renal ischemia-reperfusion for 45 minutes. During ischemia, PRP (PRP Group, n = 15) or saline solution (SALINE Group, n = 15) was administered by subcapsular renal injection. Control kidneys were the contralateral organs removed immediately before the start of ischemia in the remaining kidneys. Survival, body weight, renal blood flow on Doppler ultrasound, kidney weight, kidney volume, blood biochemistry and histopathology were determined for all subjects and kidneys, as applicable. Correlations between these variables were searched for. The PRP Group showed significantly worse kidney blood flow (p = 0.045) and more histopathological damage (p<0.0001). Correlations were found between body weight, kidney volume, kidney weight, renal blood flow, histology, and serum levels of creatinine and urea. Our study provides the first evidence that treatment with PRP results in the deterioration of the kidney’s response to ischemia-reperfusion injury. PMID:27551718

A systematic investigation of production of synthetic prions from recombinant prion protein.

PubMed

Schmidt, Christian; Fizet, Jeremie; Properzi, Francesca; Batchelor, Mark; Sandberg, Malin K; Edgeworth, Julie A; Afran, Louise; Ho, Sammy; Badhan, Anjna; Klier, Steffi; Linehan, Jacqueline M; Brandner, Sebastian; Hosszu, Laszlo L P; Tattum, M Howard; Jat, Parmjit; Clarke, Anthony R; Klöhn, Peter C; Wadsworth, Jonathan D F; Jackson, Graham S; Collinge, John

2015-12-01

According to the protein-only hypothesis, infectious mammalian prions, which exist as distinct strains with discrete biological properties, consist of multichain assemblies of misfolded cellular prion protein (PrP). A critical test would be to produce prion strains synthetically from defined components. Crucially, high-titre 'synthetic' prions could then be used to determine the structural basis of infectivity and strain diversity at the atomic level. While there have been multiple reports of production of prions from bacterially expressed recombinant PrP using various methods, systematic production of high-titre material in a form suitable for structural analysis remains a key goal. Here, we report a novel high-throughput strategy for exploring a matrix of conditions, additives and potential cofactors that might generate high-titre prions from recombinant mouse PrP, with screening for infectivity using a sensitive automated cell-based bioassay. Overall, approximately 20,000 unique conditions were examined. While some resulted in apparently infected cell cultures, this was transient and not reproducible. We also adapted published methods that reported production of synthetic prions from recombinant hamster PrP, but again did not find evidence of significant infectious titre when using recombinant mouse PrP as substrate. Collectively, our findings are consistent with the formation of prion infectivity from recombinant mouse PrP being a rare stochastic event and we conclude that systematic generation of prions from recombinant PrP may only become possible once the detailed structure of authentic ex vivo prions is solved. © 2015 The Authors.

A systematic investigation of production of synthetic prions from recombinant prion protein

PubMed Central

Schmidt, Christian; Fizet, Jeremie; Properzi, Francesca; Batchelor, Mark; Sandberg, Malin K.; Edgeworth, Julie A.; Afran, Louise; Ho, Sammy; Badhan, Anjna; Klier, Steffi; Linehan, Jacqueline M.; Brandner, Sebastian; Hosszu, Laszlo L. P.; Tattum, M. Howard; Jat, Parmjit; Clarke, Anthony R.; Klöhn, Peter C.; Wadsworth, Jonathan D. F.; Jackson, Graham S.; Collinge, John

2015-01-01

According to the protein-only hypothesis, infectious mammalian prions, which exist as distinct strains with discrete biological properties, consist of multichain assemblies of misfolded cellular prion protein (PrP). A critical test would be to produce prion strains synthetically from defined components. Crucially, high-titre ‘synthetic' prions could then be used to determine the structural basis of infectivity and strain diversity at the atomic level. While there have been multiple reports of production of prions from bacterially expressed recombinant PrP using various methods, systematic production of high-titre material in a form suitable for structural analysis remains a key goal. Here, we report a novel high-throughput strategy for exploring a matrix of conditions, additives and potential cofactors that might generate high-titre prions from recombinant mouse PrP, with screening for infectivity using a sensitive automated cell-based bioassay. Overall, approximately 20 000 unique conditions were examined. While some resulted in apparently infected cell cultures, this was transient and not reproducible. We also adapted published methods that reported production of synthetic prions from recombinant hamster PrP, but again did not find evidence of significant infectious titre when using recombinant mouse PrP as substrate. Collectively, our findings are consistent with the formation of prion infectivity from recombinant mouse PrP being a rare stochastic event and we conclude that systematic generation of prions from recombinant PrP may only become possible once the detailed structure of authentic ex vivo prions is solved. PMID:26631378

A Systematic Review of Autologous Platelet-Rich Plasma and Fat Graft Preparation Methods.

PubMed

Luck, Joshua; Smith, Oliver J; Mosahebi, Afshin

2017-12-01

The addition of platelet-rich plasma (PRP) to adipose tissue may improve fat graft survival, although graft retention rates vary markedly between studies. To what extent this outcome heterogeneity reflects differing methodological factors remains unknown. This systematic review aims to synthesize and critically review methodological approaches to autologous PRP and fat cotransplantation in both human and animal studies. In accordance with PRISMA guidelines, Ovid MEDLINE, Scopus, and Cochrane Library databases were searched from inception to April 2017. Data were extracted from all in vivo studies involving autologous PRP and fat cotransplantation. A secondary aim was to assess reporting of technical detail; authors were not contacted to provide missing data. From 335 articles, 23 studies were included in the qualitative synthesis. Some 21 were performed in humans and 2 in rabbits. Six studies were randomized control trials; the remainder reported on observational data. Methods of PRP extraction and activation varied markedly between studies. Fat graft preparation was comparatively more consistent. Methods of PRP and fat mixing differed significantly, especially with regards to relative volume/volume ratios. Our study represents the first systematic review of methodological factors in autologous PRP and fat cotransplantation. It demonstrates that technical factors in graft preparation and administration vary significantly between in vivo studies. Such methodological heterogeneity may explain observed differences in experimental and clinical outcomes. Reporting of key procedural information is inconsistent and often inadequate. These issues make meaningful evaluation of the PRP-enhanced fat grafting literature difficult and may limit its translation into clinical practice.

Nerve Growth Factor Increases mRNA Levels for the Prion Protein and the β -amyloid Protein Precursor in Developing Hamster Brain

NASA Astrophysics Data System (ADS)

Mobley, William C.; Neve, Rachael L.; Prusiner, Stanley B.; McKinley, Michael P.

1988-12-01

Deposition of amyloid filaments serves as a pathologic hallmark for some neurodegenerative disorders. The prion protein (PrP) is found in amyloid of animals with scrapie and humans with Creutzfeldt-Jakob disease; the β protein is present in amyloid deposits in Alzheimer disease and Down syndrome patients. These two proteins are derived from precursors that in the brain are expressed primarily in neurons and are membrane bound. We found that gene expression for PrP and the β -protein precursor (β -PP) is regulated in developing hamster brain. Specific brain regions showed distinct patterns of ontogenesis for PrP and β -PP mRNAs. The increases in PrP and β -PP mRNAs in developing basal forebrain coincided with an increase in choline acetyltransferase activity, raising the possibility that these markers might be coordinately controlled in cholinergic neurons and regulated by nerve growth factor (NGF). Injections of NGF into the brains of neonatal hamsters increased both PrP and β -PP mRNA levels. Increased PrP and β -PP mRNA levels induced by NGF were confined to regions that contain NGF-responsive cholinergic neurons and were accompanied by elevations in choline acetyltransferase. It remains to be established whether or not exogenous NGF acts to increase PrP and β -PP gene expression selectively in forebrain cholinergic neurons in the developing hamster and endogenous NGF regulates expression of these genes.

Effect of platelet-rich plasma on patients after blepharoplasty surgery.

PubMed

Parra, Fidelina; Morales-Rome, David Enrique; Campos-Rodríguez, Rafael; Cruz-Hernández, Teresita Rocío; Drago-Serrano, Maria Elisa

2018-04-01

To evaluate the effect of platelet-rich plasma (PRP) treatment on patients after blepharoplasty surgery. After undergoing blepharoplasty, 20 patients were randomly divided into two groups (n = 10 each). One was treated with autologous PRP and the other was not given any post-surgery treatment (basal group). Autologous PRP application was performed intradermically 24 h, 1 month, and 2 months post-surgery, and the outcome of the applications was assessed 1, 2, and 3 months post-surgery. The postoperative wound was assessed on a patient and observer scar assessment scale (POSAS) by patients and by an unblinded clinical observer. Statistical comparison between the two groups was analyzed by using the Mann-Whitney unpaired, two-tailed test. Significant differences were considered with P ≤ 0.05. Patient-reported data indicate that compared to the basal group, the PRP group showed no significant differences regarding pain, itching, or color, but had better values for stiffness and thickness (months 1 and 2) as well as scar irregularity (month 1). Data reported by the clinical observer showed that in comparison with the basal group, the PRP group showed no differences in vascularization or pigmentation, but had lower (better) scores regarding thickness, relief, and pliability (at all assessment times). The total assessment values from patients and the observer were significantly better for the PRP than the basal group. Autologous PRP treatment enhanced some parameters associated with healing properties, suggesting a potential therapeutic value after blepharoplasty surgery.

Evaluation of the efficacy of platelet-rich plasma and platelet-rich fibrin in alveolar defects after removal of impacted bilateral mandibular third molars

PubMed Central

Doiphode, Amol M.; Hegde, Prashanth; Mahindra, Uma; Santhosh Kumar, S. M.; Tenglikar, Pavan D.; Tripathi, Vivek

2016-01-01

Aim and Objectives: This study attempted the evaluation of the efficacy of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) in alveolar defects after removal of bilateral mandibular third molars. Materials and Methods: A total of 30 patients reporting to Department of Oral and Maxillofacial Surgery and having bilateral mandibular third molar impaction in both male and female aged between 18 and 30 years were included in this study. PRF and PRP were placed in extraction site and recalled at 2nd, 4th, and 6th month postoperatively. Data were statistically analyzed using IBM SPSS software for Windows, version 19.0. IBM Corp., Armonk, NY, USA. Results: This study showed decreased probing depth in PRF group compared to PRP and control one. This signifies a better soft tissue healing of extraction sockets with PRF as compared to the PRP and the control group and increase in the bone density highlights the use of PRP and PRF certainly as a valid method in inducing hard tissue regeneration. Conclusion: This study indicates a definite improvement in the periodontal health distal to second molar after third molar surgery in cases treated with PRF as compared to the PRP group and control group. Hence, PRP and PRF can be incorporated as an adjunct to promote wound healing and osseous regeneration in mandibular third molar extraction sites. PMID:27195227

Soluble polymorphic bank vole prion proteins induced by co-expression of quiescin sulfhydryl oxidase in E. coli and their aggregation behaviors.

PubMed

Abskharon, Romany; Dang, Johnny; Elfarash, Ameer; Wang, Zerui; Shen, Pingping; Zou, Lewis S; Hassan, Sedky; Wang, Fei; Fujioka, Hisashi; Steyaert, Jan; Mulaj, Mentor; Surewicz, Witold K; Castilla, Joaquín; Wohlkonig, Alexandre; Zou, Wen-Quan

2017-10-04

The infectious prion protein (PrP Sc or prion) is derived from its cellular form (PrP C ) through a conformational transition in animal and human prion diseases. Studies have shown that the interspecies conversion of PrP C to PrP Sc is largely swayed by species barriers, which is mainly deciphered by the sequence and conformation of the proteins among species. However, the bank vole PrP C (BVPrP) is highly susceptible to PrP Sc from different species. Transgenic mice expressing BVPrP with the polymorphic isoleucine (109I) but methionine (109M) at residue 109 spontaneously develop prion disease. To explore the mechanism underlying the unique susceptibility and convertibility, we generated soluble BVPrP by co-expression of BVPrP with Quiescin sulfhydryl oxidase (QSOX) in Escherichia coli. Interestingly, rBVPrP-109M and rBVPrP-109I exhibited distinct seeded aggregation pathways and aggregate morphologies upon seeding of mouse recombinant PrP fibrils, as monitored by thioflavin T fluorescence and electron microscopy. Moreover, they displayed different aggregation behaviors induced by seeding of hamster and mouse prion strains under real-time quaking-induced conversion. Our results suggest that QSOX facilitates the formation of soluble prion protein and provide further evidence that the polymorphism at residue 109 of QSOX-induced BVPrP may be a determinant in mediating its distinct convertibility and susceptibility.

The Patient Research Partner Network Matures: A Report from the GRAPPA 2017 Annual Meeting.

PubMed

Goel, Niti; O'Sullivan, Denis; de Wit, Maarten; Lindsay, Chris A; Bertheussen, Heidi; Latella, John; Chau, Jeffrey; MacDonald, Roland; Grieb, Suzanne; Steinkoenig, Ingrid; Campbell, Willemina

2018-06-01

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) has reached the third of 5 stages of organizational maturity regarding incorporating patient research partners (PRP) into psoriatic arthritis (PsA) and psoriasis research and educational efforts. Herein, we report the involvement of PRP at the GRAPPA 2017 annual meeting and plans for future PRP engagement.

Effects of an injectable platelet-rich fibrin on osteoblast behavior and bone tissue formation in comparison to platelet-rich plasma.

PubMed

Wang, Xuzhu; Zhang, Yufeng; Choukroun, Joseph; Ghanaati, Shahram; Miron, Richard J

2018-01-01

Platelet-rich plasma (PRP) has been utilized for many years as a regenerative agent capable of inducing vascularization of various tissues using blood-derived growth factors. Despite this, drawbacks mostly related to the additional use of anti-coagulants found in PRP have been shown to inhibit the wound healing process. For these reasons, a novel platelet concentrate has recently been developed with no additives by utilizing lower centrifugation speeds. The purpose of this study was therefore to investigate osteoblast behavior of this novel therapy (injectable-platelet-rich fibrin; i-PRF, 100% natural with no additives) when compared to traditional PRP. Human primary osteoblasts were cultured with either i-PRF or PRP and compared to control tissue culture plastic. A live/dead assay, migration assay as well as a cell adhesion/proliferation assay were investigated. Furthermore, osteoblast differentiation was assessed by alkaline phosphatase (ALP), alizarin red and osteocalcin staining, as well as real-time PCR for genes encoding Runx2, ALP, collagen1 and osteocalcin. The results showed that all cells had high survival rates throughout the entire study period irrespective of culture-conditions. While PRP induced a significant 2-fold increase in osteoblast migration, i-PRF demonstrated a 3-fold increase in migration when compared to control tissue-culture plastic and PRP. While no differences were observed for cell attachment, i-PRF induced a significantly higher proliferation rate at three and five days when compared to PRP. Furthermore, i-PRF induced significantly greater ALP staining at 7 days and alizarin red staining at 14 days. A significant increase in mRNA levels of ALP, Runx2 and osteocalcin, as well as immunofluorescent staining of osteocalcin was also observed in the i-PRF group when compared to PRP. In conclusion, the results from the present study favored the use of the naturally-formulated i-PRF when compared to traditional PRP with anti-coagulants. Further investigation into the direct role of fibrin and leukocytes contained within i-PRF are therefore warranted to better elucidate their positive role in i-PRF on tissue wound healing.

Platelet rich plasma (PRP) induces chondroprotection via increasing autophagy, anti-inflammatory markers, and decreasing apoptosis in human osteoarthritic cartilage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moussa, Mayssam, E-mail: Moussa-mayssam@hotmail.com; Lajeunesse, Daniel, E-mail: daniel.lajeunesse@umontreal.ca; Hilal, George, E-mail: George2266@gmail.com

Objectives: Autophagy constitutes a defense mechanism to overcome aging and apoptosis in osteoarthritic cartilage. Several cytokines and transcription factors are linked to autophagy and play an important role in the degradative cascade in osteoarthritis (OA). Cell therapy such as platelet rich plasma (PRP) has recently emerged as a promising therapeutic tool for many diseases including OA. However, its mechanism of action on improving cartilage repair remains to be determined. The purpose of this study is to investigate the effect of PRP on osteoarthritic chondrocytes and to elucidate the mechanism by which PRP contributes to cartilage regeneration. Methods: Osteoarthritic chondrocytes weremore » co-cultured with an increasing concentration of PRP obtained from healthy donors. The effect of PRP on the proliferation of chondrocytes was performed using cell counting and WST8 proliferation assays. Autophagy, apoptosis and intracellular level of IL-4, IL-10, and IL-13 were determined using flow cytometry analyses. Autophagy markers BECLIN and LC3II were also determined using quantitative polymerase chain reaction (qPCR). qPCR and ELISA were used to measure the expression of ADAMDTS-5, MMP3, MMP13, TIMP-1–2–3, aggregan, Collagen type 2, TGF-β, Cox-2, Il-6, FOXO1, FOXO3, and HIF-1 in tissues and co-cultured media. Results: PRP increased significantly the proliferation of chondrocytes, decreased apoptosis and increased autophagy and its markers along with its regulators FOXO1, FOXO3 and HIF-1 in osteoarthritic chondrocytes. Furthermore, PRP caused a dose-dependent significant decrease in MMP3, MMP13, and ADAMTS-5, IL-6 and COX-2 while increasing TGF-β, aggregan, and collagen type 2, TIMPs and intracellular IL-4, IL-10, IL-13. Conclusion: These results suggest that PRP could be a potential therapeutic tool for the treatment of OA. - Highlights: • Platelet Rich Plasma is suggested as a new treatment for osteoarthritis. • The proposed therapeutic effect is chondroprotection. • Chondroprotection is assumed via two major mechanisms:1-by increasing the major players in cartilage protection as as autophagy 2-by decreasing the markers of cartilage degradation such as MMPs.« less

Glycosylphosphatidylinositol Anchor Modification Machinery Deficiency Is Responsible for the Formation of Pro-Prion Protein (PrP) in BxPC-3 Protein and Increases Cancer Cell Motility*

PubMed Central

Yang, Liheng; Gao, Zhenxing; Hu, Lipeng; Wu, Guiru; Yang, Xiaowen; Zhang, Lihua; Zhu, Ying; Wong, Boon-Seng; Xin, Wei; Sy, Man-Sun; Li, Chaoyang

2016-01-01

The normal cellular prion protein (PrP) is a glycosylphosphatidylinositol (GPI)-anchored cell surface glycoprotein. However, in pancreatic ductal adenocarcinoma cell lines, such as BxPC-3, PrP exists as a pro-PrP retaining its glycosylphosphatidylinositol (GPI) peptide signaling sequence. Here, we report the identification of another pancreatic ductal adenocarcinoma cell line, AsPC-1, which expresses a mature GPI-anchored PrP. Comparison of the 24 genes involved in the GPI anchor modification pathway between AsPC-1 and BxPC-3 revealed 15 of the 24 genes, including PGAP1 and PIG-F, were down-regulated in the latter cells. We also identified six missense mutations in DPM2, PIG-C, PIG-N, and PIG-P alongside eight silent mutations. When BxPC-3 cells were fused with Chinese hamster ovary (CHO) cells, which lack endogenous PrP, pro-PrP was successfully converted into mature GPI-anchored PrP. Expression of the individual gene, such as PGAP1, PIG-F, or PIG-C, into BxPC-3 cells does not result in phosphoinositide-specific phospholipase C sensitivity of PrP. However, when PIG-F but not PIG-P is expressed in PGAP1-expressing BxPC-3 cells, PrP on the surface of the cells becomes phosphoinositide-specific phospholipase C-sensitive. Thus, low expression of PIG-F and PGAP1 is the major factor contributing to the accumulation of pro-PrP. More importantly, BxPC-3 cells expressing GPI-anchored PrP migrate much slower than BxPC-3 cells bearing pro-PrP. In addition, GPI-anchored PrP-bearing AsPC-1 cells also migrate slower than pro-PrP bearing BxPC-3 cells, although both cells express filamin A. “Knocking out” PRNP in BxPC-3 cell drastically reduces its migration. Collectively, these results show that multiple gene irregularity in BxPC-3 cells is responsible for the formation of pro-PrP, and binding of pro-PrP to filamin A contributes to enhanced tumor cell motility. PMID:26683373

Effects of subtenon-injected autologous platelet-rich plasma on visual functions in eyes with retinitis pigmentosa: preliminary clinical results.

PubMed

Arslan, Umut; Özmert, Emin; Demirel, Sibel; Örnek, Firdevs; Şermet, Figen

2018-05-01

One of the main reasons for apoptosis and dormant cell phases in degenerative retinal diseases such as retinitis pigmentosa (RP) is growth factor withdrawal in the cellular microenvironment. Growth factors and neurotrophins can significantly slow down retinal degeneration and cell death in animal models. One possible source of autologous growth factors is platelet-rich plasma. The purpose of this study was to determine if subtenon injections of autologous platelet-rich plasma (aPRP) can have beneficial effects on visual function in RP patients by reactivating dormant photoreceptors. This prospective open-label clinical trial, conducted between September 2016 and February 2017, involved 71 eyes belonging to 48 RP patients with various degrees of narrowed visual field. Forty-nine eyes belonging to 37 patients were injected with aPRP. A comparison group was made up of 11 patients who had symmetrical bilateral narrowed visual field (VF) of both eyes. Among these 11 patients, one eye was injected with aPRP, while the other eye was injected with autologous platelet-poor plasma (aPPP) to serve as a control. The total duration of the study was 9 weeks: the aPRP or aPPP subtenon injections were applied three times, with 3-week intervals between injections, and the patients were followed for three more weeks after the third injection. Visual acuity (VA) tests were conducted on all patients, and VF, microperimetry (MP), and multifocal electroretinography (mfERG) tests were conducted on suitable patients to evaluate the visual function changes before and after the aPRP or aPPP injections. The best-corrected visual acuity values in the ETDRS chart improved by 11.6 letters (from 70 to 81.6 letters) in 19 of 48 eyes following aPRP application; this result, however, was not statistically significant (p = 0.056). Following aPRP injections in 48 eyes, the mean deviation of the VF values improved from - 25.3 to - 23.1 dB (p = 0.0001). Results regarding the mfERG P1 amplitudes improved in ring 1 from 24.4 to 38.5 nv/deg 2 (p = 0.0001), in ring 2 from 6.7 to 9.3 nv/deg 2 (p = 0.0301), and in ring 3 from 3.5 to 4.5 nv/deg 2 (p = 0.0329). The mfERG P1 implicit times improved in ring 1 from 40.0 to 34.4 ms (p = 0.01), in ring 2 from 42.5 to 33.2 ms (p = 0.01), and in ring 3 from 42.1 to 37.9 ms (p = 0.04). The mfERG N1 amplitudes improved in ring 1 from 0.18 to 0.25 nv/deg 2 (p = 0.011) and in ring 2 from 0.05 to 0.08 nv/deg 2 (p = 0.014). The mfERG N1 implicit time also improved in ring 1 from 18.9 to 16.2 ms (p = 0.040) and in ring 2 from 20.9 to 15.5 ms (p = 0.002). No improvement was seen in the 11 control eyes into which aPPP was injected. In the 23 RP patients with macular involvement, the MP average threshold values improved with aPRP injections from 15.0 to 16.4 dB (p = 0.0001). No ocular or systemic adverse events related to the injections or aPRP were observed during the follow-up period. Preliminary clinical results are encouraging in terms of statistically significant improvements in VF, mfERG values, and MP. The subtenon injection of aPRP seems to be a therapeutic option for treatment and might lead to positive results in the vision of RP patients. Long-term results regarding adverse events are unknown. There have not been any serious adverse events and any ophthalmic or systemic side effects for 1 year follow-up. Further studies with long-term follow-up are needed to determine the duration of efficacy and the frequency of application.

Generating Bona Fide Mammalian Prions with Internal Deletions.

PubMed

Munoz-Montesino, Carola; Sizun, Christina; Moudjou, Mohammed; Herzog, Laetitia; Reine, Fabienne; Chapuis, Jérôme; Ciric, Danica; Igel-Egalon, Angelique; Laude, Hubert; Béringue, Vincent; Rezaei, Human; Dron, Michel

2016-08-01

Mammalian prions are PrP proteins with altered structures causing transmissible fatal neurodegenerative diseases. They are self-perpetuating through formation of beta-sheet-rich assemblies that seed conformational change of cellular PrP. Pathological PrP usually forms an insoluble protease-resistant core exhibiting beta-sheet structures but no more alpha-helical content, loosing the three alpha-helices contained in the correctly folded PrP. The lack of a high-resolution prion structure makes it difficult to understand the dynamics of conversion and to identify elements of the protein involved in this process. To determine whether completeness of residues within the protease-resistant domain is required for prions, we performed serial deletions in the helix H2 C terminus of ovine PrP, since this region has previously shown some tolerance to sequence changes without preventing prion replication. Deletions of either four or five residues essentially preserved the overall PrP structure and mutant PrP expressed in RK13 cells were efficiently converted into bona fide prions upon challenge by three different prion strains. Remarkably, deletions in PrP facilitated the replication of two strains that otherwise do not replicate in this cellular context. Prions with internal deletion were self-propagating and de novo infectious for naive homologous and wild-type PrP-expressing cells. Moreover, they caused transmissible spongiform encephalopathies in mice, with similar biochemical signatures and neuropathologies other than the original strains. Prion convertibility and transfer of strain-specific information are thus preserved despite shortening of an alpha-helix in PrP and removal of residues within prions. These findings provide new insights into sequence/structure/infectivity relationship for prions. Prions are misfolded PrP proteins that convert the normal protein into a replicate of their own abnormal form. They are responsible for invariably fatal neurodegenerative disorders. Other aggregation-prone proteins appear to have a prion-like mode of expansion in brains, such as in Alzheimer's or Parkinson's diseases. To date, the resolution of prion structure remains elusive. Thus, to genetically define the landscape of regions critical for prion conversion, we tested the effect of short deletions. We found that, surprisingly, removal of a portion of PrP, the C terminus of alpha-helix H2, did not hamper prion formation but generated infectious agents with an internal deletion that showed characteristics essentially similar to those of original infecting strains. Thus, we demonstrate that completeness of the residues inside prions is not necessary for maintaining infectivity and the main strain-specific information, while reporting one of the few if not the only bona fide prions with an internal deletion. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Generating Bona Fide Mammalian Prions with Internal Deletions

PubMed Central

Munoz-Montesino, Carola; Sizun, Christina; Moudjou, Mohammed; Herzog, Laetitia; Reine, Fabienne; Chapuis, Jérôme; Ciric, Danica; Igel-Egalon, Angelique; Laude, Hubert; Béringue, Vincent; Rezaei, Human

2016-01-01

ABSTRACT Mammalian prions are PrP proteins with altered structures causing transmissible fatal neurodegenerative diseases. They are self-perpetuating through formation of beta-sheet-rich assemblies that seed conformational change of cellular PrP. Pathological PrP usually forms an insoluble protease-resistant core exhibiting beta-sheet structures but no more alpha-helical content, loosing the three alpha-helices contained in the correctly folded PrP. The lack of a high-resolution prion structure makes it difficult to understand the dynamics of conversion and to identify elements of the protein involved in this process. To determine whether completeness of residues within the protease-resistant domain is required for prions, we performed serial deletions in the helix H2 C terminus of ovine PrP, since this region has previously shown some tolerance to sequence changes without preventing prion replication. Deletions of either four or five residues essentially preserved the overall PrP structure and mutant PrP expressed in RK13 cells were efficiently converted into bona fide prions upon challenge by three different prion strains. Remarkably, deletions in PrP facilitated the replication of two strains that otherwise do not replicate in this cellular context. Prions with internal deletion were self-propagating and de novo infectious for naive homologous and wild-type PrP-expressing cells. Moreover, they caused transmissible spongiform encephalopathies in mice, with similar biochemical signatures and neuropathologies other than the original strains. Prion convertibility and transfer of strain-specific information are thus preserved despite shortening of an alpha-helix in PrP and removal of residues within prions. These findings provide new insights into sequence/structure/infectivity relationship for prions. IMPORTANCE Prions are misfolded PrP proteins that convert the normal protein into a replicate of their own abnormal form. They are responsible for invariably fatal neurodegenerative disorders. Other aggregation-prone proteins appear to have a prion-like mode of expansion in brains, such as in Alzheimer's or Parkinson's diseases. To date, the resolution of prion structure remains elusive. Thus, to genetically define the landscape of regions critical for prion conversion, we tested the effect of short deletions. We found that, surprisingly, removal of a portion of PrP, the C terminus of alpha-helix H2, did not hamper prion formation but generated infectious agents with an internal deletion that showed characteristics essentially similar to those of original infecting strains. Thus, we demonstrate that completeness of the residues inside prions is not necessary for maintaining infectivity and the main strain-specific information, while reporting one of the few if not the only bona fide prions with an internal deletion. PMID:27226369

Does Pure Platelet-Rich Plasma Affect Postoperative Clinical Outcomes After Arthroscopic Rotator Cuff Repair? A Randomized Controlled Trial.

PubMed

Flury, Matthias; Rickenbacher, Dominik; Schwyzer, Hans-Kaspar; Jung, Christian; Schneider, Marco M; Stahnke, Katharina; Goldhahn, Jörg; Audigé, Laurent

2016-08-01

The exact role of platelet-rich plasma (PRP) in rotator cuff tendon reconstruction remains unclear. This study investigated whether an intraoperative pure PRP injection, compared with a local anesthetic injection, improves patient-reported outcomes at 3 and 6 months after arthroscopic rotator cuff repair. The hypothesis was that pure PRP improves patient-reported outcomes (Oxford Shoulder Score [OSS]) at 3 and 6 months after surgery and has the same pain-reducing effect compared with a postoperative subacromial local anesthetic (ropivacaine) injection. Randomized controlled trial; Level of evidence, 1. Between January 2011 and November 2012, a total of 120 patients who underwent arthroscopic double-row repair of a supraspinatus tendon rupture were randomized to receive either pure PRP by an injection at the footprint (PRP group; n = 60) or ropivacaine injected in the subacromial region (control group; n = 60). Seventy-eight percent of patients had other concomitant tears. All patients, surgeons, and follow-up investigators were blinded. Clinical parameters and various outcome scores (Constant-Murley shoulder score; OSS; patient American Shoulder and Elbow Surgeons score; quick Disabilities of the Arm, Shoulder and Hand score; EuroQol 5 dimensions) were documented preoperatively and at 3, 6, and 24 months postoperatively. The repair integrity was assessed by magnetic resonance imaging or ultrasound at 24 months. Furthermore, a pain diary was completed within the first 10 postoperative days, and adverse events were recorded. Group outcome differences were analyzed using t tests, Fisher exact tests, and mixed models. The final follow-up rate was 91%. An associated tear of the subscapularis tendon was diagnosed in 23% of PRP-treated patients and 36% of control patients. Three months after surgery, the mean (±SD) OSS was 32.9 ± 8.6 in PRP-treated patients and 30.7 ± 10.0 in control patients (P = .221). No significant differences were noted for other outcome parameters as well as at 6 and 24 months postoperatively. Smoking was a significant effect modifier. Pain for both groups decreased from postoperative day 1 to 10 without any significant group difference (P = .864). Six (12.2%) and 11 (20.8%) patients were diagnosed with a recurrent supraspinatus tendon defect in the PRP and control groups, respectively (P = .295). Twenty-two (40.7%) and 18 (30.5%) PRP-treated and control patients, respectively, experienced a local adverse event within 24 months (P = .325). Patients treated with pure PRP showed no significantly improved function at 3, 6, and 24 months after arthroscopic repair compared with control patients receiving ropivacaine; however, a similar pain reduction was documented in both groups. The negative influence of smoking on the effect of pure PRP requires further investigation. NCT01266226 (ClinicalTrials.gov). © 2016 The Author(s).

Platelet-rich plasma injections: an emerging therapy for chronic discogenic low back pain.

PubMed

Mohammed, Suja; Yu, James

2018-03-01

Autologous platelet-rich plasma (PRP) injections have been investigated in recent years as an emerging therapy for various musculoskeletal conditions, including lumbar degenerative disc disease. Although PRP has received increasing attention from medical science experts, comprehensive clinical reports of its efficacy are limited to those treating knee osteoarthritis and epicondylitis. Use of PRP is gaining popularity in the area of degenerative disc disease, but there is a clear need for reliable clinical evidence of its applications and effectiveness. In this article, we review the current literature on PRP therapy and its potential use in the treatment of chronic discogenic low back pain, with a focus on evidence from clinical trials.

A conformational switch in PRP8 mediates metal ion coordination that promotes pre-mRNA exon ligation

PubMed Central

Schellenberg, Matthew J.; Wu, Tao; Ritchie, Dustin B.; Fica, Sebastian; Staley, Jonathan P.; Atta, Karim A.; LaPointe, Paul; MacMillan, Andrew M.

2013-01-01

SUMMARY Splicing of pre-mRNAs in eukaryotes is catalyzed by the spliceosome a large RNA–protein metalloenzyme. The catalytic center of the spliceosome involves a structure comprised of the U2 and U6 snRNAs and includes a metal bound by U6 snRNA. The precise architecture of the splicesome active site however, including the question of whether it includes protein components, remains unresolved. A wealth of evidence places the protein PRP8 at the heart of the spliceosome through assembly and catalysis. Here we provide evidence that the RNase H domain of PRP8 undergoes a conformational switch between the two steps of splicing rationalizing yeast prp8 alleles promoting either the first or second step. We also show that this switch unmasks a metal-binding site involved in the second step. Together these data establish that PRP8 is a metalloprotein that promotes exon ligation within the spliceosome. PMID:23686287

School-based prevention of depressive symptoms: A randomized controlled study of the effectiveness and specificity of the Penn Resiliency Program.

PubMed

Gillham, Jane E; Reivich, Karen J; Freres, Derek R; Chaplin, Tara M; Shatté, Andrew J; Samuels, Barbra; Elkon, Andrea G L; Litzinger, Samantha; Lascher, Marisa; Gallop, Robert; Seligman, Martin E P

2007-02-01

The authors investigated the effectiveness and specificity of the Penn Resiliency Program (PRP; J. E. Gillham, L. H. Jaycox, K. J. Reivich, M. E. P. Seligman, & T. Silver, 1990), a cognitive-behavioral depression prevention program. Children (N = 697) from 3 middle schools were randomly assigned to PRP, Control (CON), or the Penn Enhancement Program (PEP; K. J. Reivich, 1996; A. J. Shatté, 1997), an alternate intervention that controls for nonspecific intervention ingredients. Children's depressive symptoms were assessed through 3 years of follow-up. There was no intervention effect on average levels of depressive symptoms in the full sample. Findings varied by school. In 2 schools, PRP significantly reduced depressive symptoms across the follow-up relative to both CON and PEP. In the 3rd school, PRP did not prevent depressive symptoms. The authors discuss the findings in relation to previous research on PRP and the dissemination of prevention programs. Copyright 2007 APA, all rights reserved.

School-Based Prevention of Depressive Symptoms: A Randomized Controlled Study of the Effectiveness and Specificity of the Penn Resiliency Program

PubMed Central

Gillham, Jane E.; Reivich, Karen J.; Freres, Derek R.; Chaplin, Tara M.; Shatté, Andrew J.; Samuels, Barbra; Elkon, Andrea G. L.; Litzinger, Samantha; Lascher, Marisa; Gallop, Robert; Seligman, Martin E. P.

2015-01-01

The authors investigated the effectiveness and specificity of the Penn Resiliency Program (PRP; J. E. Gillham, L. H. Jaycox, K. J. Reivich, M. E. P. Seligman, & T. Silver, 1990), a cognitive–behavioral depression prevention program. Children (N = 697) from 3 middle schools were randomly assigned to PRP, Control (CON), or the Penn Enhancement Program (PEP; K. J. Reivich, 1996; A. J. Shatté, 1997), an alternate intervention that controls for nonspecific intervention ingredients. Children’s depressive symptoms were assessed through 3 years of follow-up. There was no intervention effect on average levels of depressive symptoms in the full sample. Findings varied by school. In 2 schools, PRP significantly reduced depressive symptoms across the follow-up relative to both CON and PEP. In the 3rd school, PRP did not prevent depressive symptoms. The authors discuss the findings in relation to previous research on PRP and the dissemination of prevention programs. PMID:17295559

Leukocyte Inclusion within a Platelet Rich Plasma-Derived Fibrin Scaffold Stimulates a More Pro-Inflammatory Environment and Alters Fibrin Properties

PubMed Central

Anitua, Eduardo; Zalduendo, Mar; Troya, María; Padilla, Sabino; Orive, Gorka

2015-01-01

One of the main differences among platelet-rich plasma (PRP) products is the inclusion of leukocytes that may affect the biological efficacy of these autologous preparations. The purpose of this study was to evaluate whether the addition of leukocytes modified the morphological, biomechanical and biological properties of PRP under normal and inflammatory conditions. The release of pro-inflammatory cytokines from plasma rich in growth factors (PRGF) and leukocyte-platelet rich plasma (L-PRP) scaffolds was determined by enzyme-linked immunosorbent assay (ELISA) and was significantly increased under an inflammatory condition when leukocytes were included in the PRP. Fibroblasts and osteoblasts treated with L-PRP, under an inflammatory situation, underwent a greater activation of NFĸB pathway, proliferated significantly less and secreted a higher concentration of pro-inflammatory cytokines. These cellular events were assessed through Western blot and fluorimetric and ELISA methods, respectively. Therefore, the inclusion of leukocytes induced significantly higher pro-inflammatory conditions. PMID:25823008

Antimicrobial effect of platelet-rich plasma and platelet-rich fibrin.

PubMed

Badade, Pallavi S; Mahale, Swapna A; Panjwani, Alisha A; Vaidya, Prutha D; Warang, Ayushya D

2016-01-01

Platelet concentrates have been extensively used in a variety of medical fields to promote soft- and hard-tissue regeneration. The significance behind their use lies in the abundance of growth factors (GFs) in platelets α-granules that promote wound healing. Other than releasing a pool of GFs upon activation, platelets also have many features that indicate their role in the anti-infective host defense. The aim of this study is to evaluate the antimicrobial activities of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) against periodontal disease-associated bacteria. Blood samples were obtained from ten adult male patients. PRP and PRF were procured using centrifugation. The antimicrobial activity of PRP and PRF was evaluated by microbial culturing using bacterial strains of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. P. gingivalis and A. actinomycetemcomitans were inhibited by PRP but not by PRF. PRP is a potentially useful substance in the fight against periodontal pathogens. This might represent a valuable property in adjunct to the enhancement of tissue regeneration.

Platelet-rich plasma (PRP) for knee disorders

PubMed Central

Shahid, Mohammad; Kundra, Rik

2017-01-01

Platelet-rich plasma (PRP) is an autologous blood product with platelet concentrations above baseline values. The process involves the extraction of blood from the patient which is then centrifuged to obtain a concentrated suspension of platelets by plasmapheresis. It then undergoes a two-stage centrifugation process to separate the solid and liquid components of the anticoagulated blood. PRP owes its therapeutic use to the growth factors released by the platelets which are claimed to possess multiple regenerative properties. In the knee, PRP has been used in patients with articular cartilage pathology, ligamentous and meniscal injuries. There is a growing body of evidence to support its use in selected indications and this review looks at the most recent evidence. We also look at the current UK National Institute of Health & Clinical Excellence (NICE) guidelines with respect to osteoarthritis and the use of PRP in the knee. Cite this article: EFORT Open Rev 2017;2:28–34. DOI: 10.1302/2058-5241.2.160004. PMID:28607768

Effect of autologous platelet-rich plasma on the chondrogenic differentiation of rabbit adipose-derived stem cells in vitro

PubMed Central

TANG, XIAO-BO; DONG, PEI-LONG; WANG, JIAN; ZHOU, HAI-YANG; ZHANG, HAI-XIANG; WANG, SHAN-ZHENG

2015-01-01

This study aimed to isolate rabbit adipose-derived stem cells (ADSCs) and explore the potential of platelet-rich plasma (PRP) in the chondrogenic differentiation of ADSCs, thereby potentially providing a new approach for the repair and regeneration of cartilage injury. Rabbit ADSCs were isolated and characterized by induction towards adipogenic, osteogenic and chondrogenic lineages in vitro. The isolated ADSCs were also cultured with or without 10% PRP. Immunofluorescence staining, toluidine blue staining and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to detect type II collagen (Col II) and aggrecan (AGC) expression. Col II immunofluorescence staining and toluidine blue staining indicated that following induction by autologous PRP, ADSCs manifested Col II and AGC expression. The expression of Col II and AGC mRNA was significantly upregulated in the PRP-treated cells when compared with that in control cells. Autologous PRP produced by laboratory centrifugation was able to promote the chondrogenic differentiation of rabbit ADSCs in vitro. PMID:26622340

An evidence-based evaluation on the use of platelet rich plasma in orthopedics – a review of the literature

PubMed Central

Hussain, Nasir; Johal, Herman; Bhandari, Mohit

2017-01-01

Within orthopedics, the use of platelet-rich plasma (PRP) has been rapidly increasing in popularity, however, its true effectiveness has yet to be fully established. Several studies find that injecting PRP to the site of injury does not provide any significant benefit with respect to clinical outcomes; however, many others report the contrary. Due to the conflicting evidence and multiple meta-analyses conducted on the topic, a literature review of high-quality evidence on the use of PRP for common orthopaedic conditions was performed. Thus far, the evidence appears to suggest that PRP may provide some benefit in patients who present with knee osteoarthritis or lateral epicondylitis. On the other hand, evidence appears to be inconsistent or shows a minimal benefit for PRP usage in rotator cuff repair, patellar and Achilles tendinopathies, hamstring injuries, anterior cruciate ligament (ACL) repair, and medial epicondylitis. There is limited confidence in the conclusions from the published meta-analyses due to issues with statistical pooling, and limited subgroup analyses exploring the substantial heterogeneity across studies. Evidence-based clinicians considering the use of PRP in their patients with musculoskeletal injuries should be weary that the literature appears to be inconsistent and thus far, inconclusive. PMID:28990574

Multimodal fluorescence microscopy of prion strain specific PrP deposits stained by thiophene-based amyloid ligands.

PubMed

Magnusson, Karin; Simon, Rozalyn; Sjölander, Daniel; Sigurdson, Christina J; Hammarström, Per; Nilsson, K Peter R

2014-01-01

The disease-associated prion protein (PrP) forms aggregates which vary in structural conformation yet share an identical primary sequence. These variations in PrP conformation are believed to manifest in prion strains exhibiting distinctly different periods of disease incubation as well as regionally specific aggregate deposition within the brain. The anionic luminescent conjugated polythiophene (LCP), polythiophene acetic acid (PTAA) has previously been used to distinguish PrP deposits associated with distinct mouse adapted strains via distinct fluorescence emission profiles from the dye. Here, we employed PTAA and 3 structurally related chemically defined luminescent conjugated oligothiophenes (LCOs) to stain brain tissue sections from mice inoculated with 2 distinct prion strains. Our results showed that in addition to emission spectra, excitation, and fluorescence lifetime imaging microscopy (FLIM) can fruitfully be assessed for optical distinction of PrP deposits associated with distinct prion strains. Our findings support the theory that alterations in LCP/LCO fluorescence are due to distinct conformational restriction of the thiophene backbone upon interaction with PrP aggregates associated with distinct prion strains. We foresee that LCP and LCO staining in combination with multimodal fluorescence microscopy might aid in detecting structural differences among discrete protein aggregates and in linking protein conformational features with disease phenotypes for a variety of neurodegenerative proteinopathies.

Multimodal fluorescence microscopy of prion strain specific PrP deposits stained by thiophene-based amyloid ligands

PubMed Central

Magnusson, Karin; Simon, Rozalyn; Sjölander, Daniel; Sigurdson, Christina J; Hammarström, Per; Nilsson, K Peter R

2014-01-01

The disease-associated prion protein (PrP) forms aggregates which vary in structural conformation yet share an identical primary sequence. These variations in PrP conformation are believed to manifest in prion strains exhibiting distinctly different periods of disease incubation as well as regionally specific aggregate deposition within the brain. The anionic luminescent conjugated polythiophene (LCP), polythiophene acetic acid (PTAA) has previously been used to distinguish PrP deposits associated with distinct mouse adapted strains via distinct fluorescence emission profiles from the dye. Here, we employed PTAA and 3 structurally related chemically defined luminescent conjugated oligothiophenes (LCOs) to stain brain tissue sections from mice inoculated with 2 distinct prion strains. Our results showed that in addition to emission spectra, excitation, and fluorescence lifetime imaging microscopy (FLIM) can fruitfully be assessed for optical distinction of PrP deposits associated with distinct prion strains. Our findings support the theory that alterations in LCP/LCO fluorescence are due to distinct conformational restriction of the thiophene backbone upon interaction with PrP aggregates associated with distinct prion strains. We foresee that LCP and LCO staining in combination with multimodal fluorescence microscopy might aid in detecting structural differences among discrete protein aggregates and in linking protein conformational features with disease phenotypes for a variety of neurodegenerative proteinopathies. PMID:25495506

Platelet-rich plasma for regeneration of neural feedback pathways around dental implants: a concise review and outlook on future possibilities

PubMed Central

Huang, Yan; Bornstein, Michael M; Lambrichts, Ivo; Yu, Hai-Yang; Politis, Constantinus; Jacobs, Reinhilde

2017-01-01

Along with the development of new materials, advanced medical imaging and surgical techniques, osseointegrated dental implants are considered a successful and constantly evolving treatment modality for the replacement of missing teeth in patients with complete or partial edentulism. The importance of restoring the peripheral neural feedback pathway and thus repairing the lack of periodontal mechanoreceptors after tooth extraction has been highlighted in the literature. Nevertheless, regenerating the nerve fibers and reconstructing the neural feedback pathways around osseointegrated implants remain a challenge. Recent studies have provided evidence that platelet-rich plasma (PRP) therapy is a promising treatment for musculoskeletal injuries. Because of its high biological safety, convenience and usability, PRP therapy has gradually gained popularity in the clinical field. Although much remains to be learned, the growth factors from PRP might play key roles in peripheral nerve repair mechanisms. This review presents known growth factors contributing to the biological efficacy of PRP and illustrates basic and (pre-)clinical evidence regarding the use of PRP and its relevant products in peripheral nerve regeneration. In addition, the potential of local application of PRP for structural and functional recovery of injured peripheral nerves around dental implants is discussed. PMID:28282030

Antimicrobial activity of platelet-rich plasma and other plasma preparations against periodontal pathogens.

PubMed

Yang, Li-Chiu; Hu, Suh-Woan; Yan, Min; Yang, Jaw-Ji; Tsou, Sing-Hua; Lin, Yuh-Yih

2015-02-01

In addition to releasing a pool of growth factors during activation, platelets have many features that indicate their role in the anti-infective host defense. The antimicrobial activities of platelet-rich plasma (PRP) and related plasma preparations against periodontal disease-associated bacteria were evaluated. Four distinct plasma fractions were extracted in the formulation used commonly in dentistry and were tested for their antibacterial properties against three periodontal bacteria: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. The minimum inhibitory concentration of each plasma preparation was determined, and in vitro time-kill assays were used to detect their abilities to inhibit bacterial growth. Bacterial adhesion interference and the susceptibility of bacterial adherence by these plasma preparations were also conducted. All plasma preparations can inhibit bacterial growth, with PRP showing the superior activity. Bacterial growth inhibition by PRP occurred in the first 24 hours after application in the time-kill assay. PRP interfered with P. gingivalis and A. actinomycetemcomitans attachment and enhanced exfoliation of attached P. gingivalis but had no influences on F. nucleatum bacterial adherence. PRP expressed antibacterial properties, which may be attributed to platelets possessing additional antimicrobial molecules. The application of PRP on periodontal surgical sites is advisable because of its regenerative potential and its antibacterial effects.

CEF1/CDC5 alleles modulate transitions between catalytic conformations of the spliceosome

PubMed Central

Query, Charles C.; Konarska, Maria M.

2012-01-01

Conformational change within the spliceosome is required between the first and second catalytic steps of pre-mRNA splicing. A prior genetic screen for suppressors of an intron mutant that stalls between the two steps yielded both prp8 and non-prp8 alleles that suppressed second-step splicing defects. We have now identified the strongest non-prp8 suppressors as alleles of the NTC (Prp19 complex) component, CEF1. These cef1 alleles generally suppress second-step defects caused by a variety of intron mutations, mutations in U6 snRNA, or deletion of the second-step protein factor Prp17, and they can activate alternative 3′ splice sites. Genetic and functional interactions between cef1 and prp8 alleles suggest that they modulate the same event(s) in the first-to-second-step transition, most likely by stabilization of the second-step spliceosome; in contrast, alleles of U6 snRNA that also alter this transition modulate a distinct event, most likely by stabilization of the first-step spliceosome. These results implicate a myb-like domain of Cef1/CDC5 in interactions that modulate conformational states of the spliceosome and suggest that alteration of these events affects splice site use, resulting in alternative splicing-like patterns in yeast. PMID:22408182

Platelet-rich plasma injection is more effective than hyaluronic acid in the treatment of knee osteoarthritis.

PubMed

Say, F; Gürler, D; Yener, K; Bülbül, M; Malkoc, M

2013-01-01

There is increasing use of platelet-rich plasma (PRP) in orthopaedics as it is a simple, cheap and minimally invasive technique. This study aimed to compare the effects of the use of PRP and hyaluronic acid (HA) injections in the knee of patients diagnosed with and being followed-up for degenerative arthritis. This prospective study included 90 patients with complaints of knee pain with findings of mild or moderate degenerative arthritis. In the PRP group (n=45), one intra-articular injection was applied and in the HA group (n=45), three doses of intra-articular injection were applied. Clinical evaluation was made by Knee Injury and Osteoarthritis Outcome Score (KOOS) and a visual pain scale. No severe adverse events was observed. Statistically significant better results in the KOOS score and visual pain scale was determined in PRP group than HA group at 3 months and 6 months follow up. The cost of the application for the PRP group was lower than that of the HA group. The results of this study have shown the application of single dose PRP to be a safe, effective and low-cost method for treating OA. However, further studies are required for a more clear result.

A naturally occurring variant of the human prion protein completely prevents prion disease.

PubMed

Asante, Emmanuel A; Smidak, Michelle; Grimshaw, Andrew; Houghton, Richard; Tomlinson, Andrew; Jeelani, Asif; Jakubcova, Tatiana; Hamdan, Shyma; Richard-Londt, Angela; Linehan, Jacqueline M; Brandner, Sebastian; Alpers, Michael; Whitfield, Jerome; Mead, Simon; Wadsworth, Jonathan D F; Collinge, John

2015-06-25

Mammalian prions, transmissible agents causing lethal neurodegenerative diseases, are composed of assemblies of misfolded cellular prion protein (PrP). A novel PrP variant, G127V, was under positive evolutionary selection during the epidemic of kuru--an acquired prion disease epidemic of the Fore population in Papua New Guinea--and appeared to provide strong protection against disease in the heterozygous state. Here we have investigated the protective role of this variant and its interaction with the common, worldwide M129V PrP polymorphism. V127 was seen exclusively on a M129 PRNP allele. We demonstrate that transgenic mice expressing both variant and wild-type human PrP are completely resistant to both kuru and classical Creutzfeldt-Jakob disease (CJD) prions (which are closely similar) but can be infected with variant CJD prions, a human prion strain resulting from exposure to bovine spongiform encephalopathy prions to which the Fore were not exposed. Notably, mice expressing only PrP V127 were completely resistant to all prion strains, demonstrating a different molecular mechanism to M129V, which provides its relative protection against classical CJD and kuru in the heterozygous state. Indeed, this single amino acid substitution (G→V) at a residue invariant in vertebrate evolution is as protective as deletion of the protein. Further study in transgenic mice expressing different ratios of variant and wild-type PrP indicates that not only is PrP V127 completely refractory to prion conversion but acts as a potent dose-dependent inhibitor of wild-type prion propagation.

A Systematic Review of Autologous Platelet-Rich Plasma and Fat Graft Preparation Methods

PubMed Central

Smith, Oliver J.; Mosahebi, Afshin

2017-01-01

Background: The addition of platelet-rich plasma (PRP) to adipose tissue may improve fat graft survival, although graft retention rates vary markedly between studies. To what extent this outcome heterogeneity reflects differing methodological factors remains unknown. This systematic review aims to synthesize and critically review methodological approaches to autologous PRP and fat cotransplantation in both human and animal studies. Methods: In accordance with PRISMA guidelines, Ovid MEDLINE, Scopus, and Cochrane Library databases were searched from inception to April 2017. Data were extracted from all in vivo studies involving autologous PRP and fat cotransplantation. A secondary aim was to assess reporting of technical detail; authors were not contacted to provide missing data. Results: From 335 articles, 23 studies were included in the qualitative synthesis. Some 21 were performed in humans and 2 in rabbits. Six studies were randomized control trials; the remainder reported on observational data. Methods of PRP extraction and activation varied markedly between studies. Fat graft preparation was comparatively more consistent. Methods of PRP and fat mixing differed significantly, especially with regards to relative volume/volume ratios. Conclusions: Our study represents the first systematic review of methodological factors in autologous PRP and fat cotransplantation. It demonstrates that technical factors in graft preparation and administration vary significantly between in vivo studies. Such methodological heterogeneity may explain observed differences in experimental and clinical outcomes. Reporting of key procedural information is inconsistent and often inadequate. These issues make meaningful evaluation of the PRP-enhanced fat grafting literature difficult and may limit its translation into clinical practice. PMID:29632775

Comparative effectiveness of platelet-rich plasma injections for treating knee joint cartilage degenerative pathology: a systematic review and meta-analysis.

PubMed

Chang, Ke-Vin; Hung, Chen-Yu; Aliwarga, Fanny; Wang, Tyng-Guey; Han, Der-Sheng; Chen, Wen-Shiang

2014-03-01

To explore the effectiveness of platelet-rich plasma (PRP) in treating cartilage degenerative pathology in knee joints. Electronic databases, including PubMed and Scopus, were searched from the earliest record to September 2013. We included single-arm prospective studies, quasi-experimental studies, and randomized controlled trials that used PRP to treat knee chondral degenerative lesions. Eight single-arm studies, 3 quasi-experimental studies, and 5 randomized controlled trials were identified, comprising 1543 participants. We determined effect sizes for the selected studies by extracting changes in functional scales after the interventions and compared the PRP group pooled values with the pretreatment baseline and the groups receiving placebo or hyaluronic acid (HA) injections. PRP injections in patients with knee degenerative pathology showed continual efficacy for 12 months compared with their pretreatment condition. The effectiveness of PRP was likely better and more prolonged than that of HA. Injection doses ≤2, the use of a single-spinning approach, and lack of additional activators led to an uncertainty in the treatment effects. Patients with lower degrees of cartilage degeneration achieved superior outcomes as opposed to those affected by advanced osteoarthritis. PRP application improves function from basal evaluations in patients with knee joint cartilage degenerative pathology and tends to be more effective than HA administration. Discrepancy in the degenerative severity modifies the treatment responses, leading to participants with lower degrees of degeneration benefiting more from PRP injections. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The Efficacy of Platelet-Rich Plasma in the Treatment of Rib Fractures.

PubMed

Gunay, Samil; Candan, Huseyin; Yılmaz, Rahsan; Eser, Irfan; Aydoğmus, Umit

2017-10-01

Background  Rib fracture is the most common result of thoracic traumas. Intrapulmonary shunt, alveolar capillary membrane damage, intra-alveolar hemorrhage, and hypoxia may develop following rib fractures. Therefore, prompt treatment is important. The aim of this experimental study was to analyze the effects of platelet-rich plasma (PRP) on rib fractures to secure a speedier and more efficient treatment method. Materials and Methods  The study involved 18 New Zealand white rabbits, randomly divided into three groups as Group 1, the sham group with no surgical intervention; Group 2, the control group in which simple rib fractures were applied and no treatment; and Group 3, in which rib fractures were applied and then PRP treatment was administered. Results  The mean recovery plate thickness measurements were found to be statistically significantly higher in the PRP group compared with the other groups ( p  < 0.005). A thicker fibrotic cell proliferation and the formation of many capillaries were observed around the growth plate in the PRP group compared with the other groups. These structures were lesser in the control group compared with the PRP group and at the lowest level in the sham group. Larger and distinct callus formation was observed and a new intramedullary field in the PRP group. Conclusions  PRP is a reliable and effective autologous product with minimal side effects, which can be considered as an alternative treatment in patients with rib fractures and used easily in pseudoarthrosis, surgical fracture, or flail chest. Georg Thieme Verlag KG Stuttgart · New York.

Influence of calcium salts and bovine thrombin on growth factor release from equine platelet-rich gel supernatants.

PubMed

Giraldo, Carlos E; Álvarez, María E; Carmona, Jorge U

2017-01-16

To compare five activation methods in equine platelet-rich plasma (PRP) by determination of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor beta 1 (TGF-β1) concentrations in platelet-rich gel (PRG) supernatants. Platelet-rich plasma from 20 horses was activated by calcium chloride (CC), calcium gluconate (CG), bovine thrombin (BT), and their combinations, BTCC and BTCG. Both growth factor concentrations in PRG supernatants were measured by ELISA and compared with plasma and platelet lysates (PL) over time. Growth factor concentrations were significantly lower in plasma and higher for all PRG supernatants. Platelet lysates contained a significantly lower concentration of PDGF-BB than PRG supernatants and a significantly higher concentration of TGF-β1 than PRG supernatants. Clots from PRP activated with sodium salts were more stable over time and had significant growth factor release, whereas CC produced gross salt deposition. Significant correlations were noticed for platelet with leukocyte concentrations in PRP (r s : 0.76), platelet counts in PRP with TGF-β1 concentrations in PRG supernatants (r s : 0.86), platelet counts in PRP with PDGF-BB concentrations in PRG supernatants (r s : 0.78), leukocyte counts in PRP with TGF-β1 concentrations in PRG supernatants (r s : 0.76), and PDGF-BB concentrations with activating substances (r s : 0.72). Calcium gluconate was the better substance to induce PRP activation. It induced growth factor release free from calcium precipitates in the clots. Use of BT alone or combined with calcium salts was not advantageous for growth factor release.

Evaluation of two platelet-rich plasma processing methods and two platelet-activation techniques for use in llamas and alpacas.

PubMed

Semevolos, Stacy A; Youngblood, Cori D; Grissom, Stephanie K; Gorman, M Elena; Larson, Maureen K

2016-11-01

OBJECTIVE To evaluate 2 processing methods (commercial kit vs conical tube centrifugation) for preparing platelet rich plasma (PRP) for use in llamas and alpacas. SAMPLES Blood samples (30 mL each) aseptically collected from 6 healthy llamas and 6 healthy alpacas. PROCEDURES PRP was prepared from blood samples by use of a commercial kit and by double-step conical tube centrifugation. A CBC was performed for blood and PRP samples. Platelets in PRP samples were activated by means of a freeze-thaw method with or without 23mM CaCl 2 , and concentrations of platelet-derived growth factor-BB and transforming growth factor-β 1 were measured. Values were compared between processing methods and camelid species. RESULTS Blood CBC values for llamas and alpacas were similar. The commercial kit yielded a significantly greater degree of platelet enrichment (mean increase, 8.5 fold vs 2.8 fold) and WBC enrichment (mean increase, 3.7 fold vs 1.9 fold) than did conical tube centrifugation. Llamas had a significantly greater degree of platelet enrichment than alpacas by either processing method. No difference in WBC enrichment was identified between species. Concentrations of both growth factors were significantly greater in PRP samples obtained by use of the commercial kit versus those obtained by conical tube centrifugation. CONCLUSIONS AND CLINICAL RELEVANCE For blood samples from camelids, the commercial kit yielded a PRP product with a higher platelet and WBC concentration than achieved by conical tube centrifugation. Optimal PRP platelet and WBC concentrations for various applications need to be determined for llamas and alpacas.

Assessment of canine autologous platelet-rich plasma produced with a commercial centrifugation and platelet recovery kit.

PubMed

Frye, Chris W; Enders, Andrew; Brooks, Marjory B; Struble, Angela M; Wakshlag, Joseph J

2016-01-01

To characterize the cellular composition (platelets, erythrocytes, and leukocytes) and confirm reproducibility of platelet enrichment, as well as determine the platelet activation status in the final product of a commercial platelet-rich plasma kit using canine blood. Venous blood from 20 sedated client-owned dogs was used to prepare platelet-rich plasma (PRP) from a commercial kit. Complete blood counts were performed to determine erythrocyte, leukocyte, and platelet numbers in both whole blood (WB) and resultant PRP. The WB and PRP samples from jugular (fast collection) and cephalic (slow collection) venipuncture were also compared. P-selectin externalization was measured in WB and PRP samples from 15 of 20 dogs. This commercial kit produced an average percent recovery in platelets of 64.7 ± 17.4; erythrocytes of 3.7 ± 0.8, and leukocytes of 31.6 ± 10.0. Neutrophil, monocyte, and lymphocyte percent recovery was 19.6 ± 7.2, 44.89 ± 19.8, and 57.5 ± 10.6, respectively. The recovery of platelets from jugular venipuncture (59.7 ± 13.6%) was lower than from cephalic recovery (68.8 ± 19.1%). The mean percent P-Selectin externalization for WB, PRP, and PRP with thrombin was 25.5 ± 30.9, 4.5 ± 6.4, and 90.6 ± 4.4 respectively. Cellular reproducibility of this kit was confirmed and platelets were concentrated within autologous serum. Additionally, measurements of P-selectin externalization showed that platelets are inactive in PRP unless stimulated to degranulate.

14 CFR 1214.504 - Screening requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 1214.504 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Mission... persons who are certified under the PRP will have unescorted access to mission critical space systems... regulation provides for unescorted access to mission critical space systems areas, it does not preclude the...

14 CFR 1214.504 - Screening requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 1214.504 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Mission... persons who are certified under the PRP will have unescorted access to mission critical space systems... regulation provides for unescorted access to mission critical space systems areas, it does not preclude the...

14 CFR 1214.504 - Screening requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 1214.504 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Mission... persons who are certified under the PRP will have unescorted access to mission critical space systems... regulation provides for unescorted access to mission critical space systems areas, it does not preclude the...

Copper Coordination in the Full-Length, Recombinant Prion Protein†

PubMed Central

Burns, Colin S.; Aronoff-Spencer, Eliah; Legname, Giuseppe; Prusiner, Stanley B.; Antholine, William E.; Gerfen, Gary J.; Peisach, Jack; Millhauser, Glenn L.

2010-01-01

The prion protein (PrP) binds divalent copper at physiologically relevant conditions and is believed to participate in copper regulation or act as a copper-dependent enzyme. Ongoing studies aim at determining the molecular features of the copper binding sites. The emerging consensus is that most copper binds in the octarepeat domain, which is composed of four or more copies of the fundamental sequence PHGGGWGQ. Previous work from our laboratory using PrP-derived peptides, in conjunction with EPR and X-ray crystallography, demonstrated that the HGGGW segment constitutes the fundamental binding unit in the octarepeat domain [Burns et al. (2002) Biochemistry 41, 3991–4001; Aronoff-Spencer et al. (2000) Biochemistry 39, 13760–13771]. Copper coordination arises from the His imidazole and sequential deprotonated glycine amides. In this present work, recombinant, full-length Syrian hamster PrP is investigated using EPR methodologies. Four copper ions are taken up in the octarepeat domain, which supports previous findings. However, quantification studies reveal a fifth binding site in the flexible region between the octarepeats and the PrP globular C-terminal domain. A series of PrP peptide constructs show that this site involves His96 in the PrP(92–96) segment GGGTH. Further examination by X-band EPR, S-band EPR, and electron spin–echo envelope spectroscopy, demonstrates coordination by the His96 imidazole and the glycine preceding the threonine. The copper affinity for this type of binding site is highly pH dependent, and EPR studies here show that recombinant PrP loses its affinity for copper below pH 6.0. These studies seem to provide a complete profile of the copper binding sites in PrP and support the hypothesis that PrP function is related to its ability to bind copper in a pH-dependent fashion. PMID:12779334

Platelet-rich plasma versus autologous blood versus steroid injection in lateral epicondylitis: systematic review and network meta-analysis.

PubMed

Arirachakaran, Alisara; Sukthuayat, Amnat; Sisayanarane, Thaworn; Laoratanavoraphong, Sorawut; Kanchanatawan, Wichan; Kongtharvonskul, Jatupon

2016-06-01

Clinical outcomes between the use of platelet-rich plasma (PRP), autologous blood (AB) and corticosteroid (CS) injection in lateral epicondylitis are still controversial. A systematic review and network meta-analysis of randomized controlled trials was conducted with the aim of comparing relevant clinical outcomes between the use of PRP, AB and CS injection. Medline and Scopus databases were searched from inception to January 2015. A network meta-analysis was performed by applying weight regression for continuous outcomes and a mixed-effect Poisson regression for dichotomous outcomes. Ten of 374 identified studies were eligible. When compared to CS, AB injection showed significantly improved effects with unstandardized mean differences (UMD) in pain visual analog scale (VAS), Disabilities of Arm Shoulder and Hand (DASH), Patient-Related Tennis Elbow Evaluation (PRTEE) score and pressure pain threshold (PPT) of -2.5 (95 % confidence interval, -3.5, -1.5), -25.5 (-33.8, -17.2), -5.3 (-9.1, -1.6) and 9.9 (5.6, 14.2), respectively. PRP injections also showed significantly improved VAS and DASH scores when compared with CS. PRP showed significantly better VAS with UMD when compared to AB injection. AB injection has a higher risk of adverse effects, with a relative risk of 1.78 (1.00, 3.17), when compared to CS. The network meta-analysis suggested no statistically significant difference in multiple active treatment comparisons of VAS, DASH and PRTEE when comparing PRP and AB injections. However, AB injection had improved DASH score and PPT when compared with PRP injection. In terms of adverse effects, AB injection had a higher risk than PRP injection. This network meta-analysis provided additional information that PRP injection can improve pain and lower the risk of complications, whereas AB injection can improve pain, disabilities scores and pressure pain threshold but has a higher risk of complications. Level I evidence.

Associations between lamb survival and prion protein genotype: analysis of data for ten sheep breeds in Great Britain

PubMed Central

Gubbins, Simon; Cook, Charlotte J; Hyder, Kieran; Boulton, Kay; Davis, Carol; Thomas, Eurion; Haresign, Will; Bishop, Stephen C; Villanueva, Beatriz; Eglin, Rachel D

2009-01-01

Background Selective breeding programmes, based on prion protein (PrP) genotype, have been introduced throughout the European Union to reduce the risk of sheep transmissible spongiform encephalopathies (TSEs). These programmes could have negative consequences on other important traits, such as fitness and production traits, if the PrP gene has pleiotropic effects or is in linkage disequilibrium with genes affecting these traits. This paper presents the results of an investigation into associations between lamb survival and PrP genotype in ten mainstream sheep breeds in Great Britain (GB). In addition, the reasons for lamb deaths were examined in order to identify any associations between these and PrP genotype. Results Survival times from birth to weaning were analysed for over 38000 lambs (2427 dead and 36096 live lambs) from 128 flocks using Cox proportional hazard models for each breed, including additive animal genetic effects. No significant associations between PrP genotype and lamb survival were identified, except in the Charollais breed for which there was a higher risk of mortality in lambs of the ARR/VRQ genotype compared with those of the ARR/ARR genotype. Significant effects of birth weight, litter size, sex, age of dam and year of birth on survival were also identified. For all breeds the reasons for death changed significantly with age; however, no significant associations between reason for death and PrP genotype were found for any of the breeds. Conclusion This study found no evidence to suggest that a selective breeding programme based on PrP genotype will have a detrimental effect on lamb survival. The only significant effect of PrP genotype identified was likely to be of little consequence because an increased risk of mortality was associated with a genotype that is selected against in current breeding strategies. PMID:19159456

Temporal growth factor release from platelet-rich plasma, trehalose lyophilized platelets, and bone marrow aspirate and their effect on tendon and ligament gene expression.

PubMed

McCarrel, Taralyn; Fortier, Lisa

2009-08-01

Platelet-rich plasma (PRP) has generated substantial interest for tendon and ligament regeneration because of the high concentrations of growth factors in platelet alpha-granules. This study compared the temporal release of growth factors from bone marrow aspirate (BMA), PRP, and lyophilized platelet product (PP), and measured their effects on tendon and ligament gene expression. Blood and BMA were collected and processed to yield PRP and plasma. Flexor digitorum superficialis tendon (FDS) and suspensory ligament (SL) explants were cultured in 10% plasma in DMEM (control), BMA, PRP, or PP. TGF-beta1 and PDGF-BB concentrations were determined at 0, 24, and 96 h of culture using ELISA. Quantitative RT-PCR for collagen types I and III (COL1A1, COL3A1), cartilage oligomeric matrix protein (COMP), decorin, and matrix metalloproteinases-3 and 13 (MMP-3, MMP-13) was performed. TGF-beta1 and PDGF-BB concentrations were highest in PRP and PP. Growth factor quantity was unchanged in BMA, increased in PRP, and decreased in PP over 4 days. TGF-beta1 and platelet concentrations were positively correlated. Lyophilized PP and PRP resulted in increased COL1A1:COL3A1 ratio, increased COMP, and decreased MMP-13 expression. BMA resulted in decreased COMP and increased MMP-3 and MMP-13 gene expression. Platelet concentration was positively correlated with COL1A1, ratio of COL1A1:COL3A1, and COMP, and negatively correlated with COL3A1, MMP-13, and MMP-3. White blood cell concentration was positively correlated with COL3A1, MMP3, and MMP13, and negatively correlated with a ratio of COL1A1:COL3A1, COMP, and decorin. These findings support further in vivo investigation of PRP and PP for treatment of tendonitis and desmitis. Copyright 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Platelet-rich plasma for the treatment of bone defects: from pre-clinical rational to evidence in the clinical practice. A systematic review.

PubMed

Roffi, Alice; Di Matteo, Berardo; Krishnakumar, Gopal Shankar; Kon, Elizaveta; Filardo, Giuseppe

2017-02-01

The treatment of large bone defects represents a significant challenge for orthopaedic surgeons. In recent years, biologic agents have also been used to further improve bone healing. Among these, platelet-rich plasma (PRP) is the most exploited strategy. The aim of the present study was to systematically review the available literature to identify: 1) preclinical in-vivo results supporting the rational of PRP use for bone healing; 2) evidence from the clinical practice on the actual clinical benefit of PRP for the treatment of fractures and complications such as delayed unions and non-unions. A systematic review of the literature was performed on the application of PRP in bone healing, using the following inclusion criteria: pre-clinical and clinical reports of any level of evidence, written in English language, published in the last 20 years (1996-2016), on the use of PRP to stimulate long-bone defect treatment, with focus on fracture and delayed/non-unions healing. The search in the Pubmed database identified 64 articles eligible for inclusion: 45 were preclinical in-vivo studies and 19 were clinical studies. Despite the fact that the overall pre-clinical results seem to support the benefit of PRP in 91.1 % of the studies, a more in depth analysis underlined a lower success rate, with a positive outcome of 84.4 % in terms of histological analysis, and even lower values considering radiological and biomechanical results (75.0 % and 72.7 % positive outcome respectively). This was also mirrored in the clinical literature, where the real benefit of PRP use to treat fractures and non-unions is still under debate. Overall, the available literature presents major limitations in terms of low quality and extreme heterogeneity, which hamper the possibility to optimize PRP treatment and translate it into a real clinical benefit despite positive preclinical findings on its biological potential to favour bone healing.

Platelet-rich plasma in rotator cuff repair: a prospective randomized study.

PubMed

Malavolta, Eduardo Angeli; Gracitelli, Mauro Emilio Conforto; Ferreira Neto, Arnaldo Amado; Assunção, Jorge Henrique; Bordalo-Rodrigues, Marcelo; de Camargo, Olavo Pires

2014-10-01

Although platelet-rich plasma (PRP) has been used in rotator cuff repair, most authors have been unable to report the advantages of this method in clinical trials. The use of PRP promotes better functional and structural results in arthroscopic rotator cuff repair. Randomized controlled trial; Level of evidence, 1. This was a prospective, randomized, double-blind study with 2 groups of 27 patients each (PRP group and control group). Complete supraspinatus tears with retraction of less than 3 cm were subjected to arthroscopic single-row repair; at the end of the surgical procedure, liquid PRP prepared by apheresis was given to the patients in the PRP group with autologous thrombin. The outcomes were assessed by the University of California at Los Angeles (UCLA) and Constant scales, visual analog scale (VAS) for pain, and magnetic resonance imaging (MRI) before and 3, 6, 12, and 24 months after surgery. The significance level was 5%. The 2 groups of patients exhibited significant clinical improvement (P < .001). Between the preoperative assessment and 24-month follow-up, the mean UCLA score increased from 13.63 ± 3.639 to 32.70 ± 3.635 and from 13.93 ± 4.649 to 32.44 ± 4.318 in the control and PRP groups, respectively (P = .916). The mean Constant score increased from 47.37 ± 11.088 to 85.15 ± 9.879 in the control group and from 46.96 ± 11.937 to 84.78 ± 14.048 in the PRP group (P = .498). The mean VAS score varied from 7.00 ± 1.939 and 6.67 ± 1.617 before surgery to 1.15 ± 1.916 and 0.96 ± 2.244 at the 24-month assessment in the control and PRP groups, respectively (P = .418). The only difference was in the mean UCLA score at 12 months, with 30.04 ± 4.528 in the control group and 32.30 ± 3.506 in the PRP group (P = .046). The control group exhibited 1 case of a complete retear and 4 partial retears, and the PRP group exhibited 2 cases of partial retears (P = .42). Platelet-rich plasma prepared by apheresis and applied in the liquid state with thrombin did not promote better clinical results at 24-month follow-up. Given the numbers available for analysis, the retear rate also did not change. © 2014 The Author(s).

Functional interactions of nucleocapsid protein of feline immunodeficiency virus and cellular prion protein with the viral RNA.

PubMed

Moscardini, Mila; Pistello, Mauro; Bendinelli, M; Ficheux, Damien; Miller, Jennifer T; Gabus, Caroline; Le Grice, Stuart F J; Surewicz, Witold K; Darlix, Jean-Luc

2002-04-19

All lentiviruses and oncoretroviruses examined so far encode a major nucleic-acid binding protein (nucleocapsid or NC* protein), approximately 2500 molecules of which coat the dimeric RNA genome. Studies on HIV-1 and MoMuLV using in vitro model systems and in vivo have shown that NC protein is required to chaperone viral RNA dimerization and packaging during virus assembly, and proviral DNA synthesis by reverse transcriptase (RT) during infection. The human cellular prion protein (PrP), thought to be the major component of the agent causing transmissible spongiform encephalopathies (TSE), was recently found to possess a strong affinity for nucleic acids and to exhibit chaperone properties very similar to HIV-1 NC protein in the HIV-1 context in vitro. Tight binding of PrP to nucleic acids is proposed to participate directly in the prion disease process. To extend our understanding of lentiviruses and of the unexpected nucleic acid chaperone properties of the human prion protein, we set up an in vitro system to investigate replication of the feline immunodeficiency virus (FIV), which is functionally and phylogenetically distant from HIV-1. The results show that in the FIV model system, NC protein chaperones viral RNA dimerization, primer tRNA(Lys,3) annealing to the genomic primer-binding site (PBS) and minus strand DNA synthesis by the homologous FIV RT. FIV NC protein is able to trigger specific viral DNA synthesis by inhibiting self-priming of reverse transcription. The human prion protein was found to mimic the properties of FIV NC with respect to primer tRNA annealing to the viral RNA and chaperoning minus strand DNA synthesis. Copyright 2002 Elsevier Science Ltd.

Caprine PrP variants harboring Asp-146, His-154 and Gln-211 alleles display reduced convertibility upon interaction with pathogenic murine prion protein in scrapie infected cells.

PubMed

Kanata, Eirini; Arsenakis, Minas; Sklaviadis, Theodoros

2016-09-02

Scrapie, the prion disease of sheep and goats, is a devastating malady of small ruminants. Due to its infectious nature, epidemic outbreaks may occur in flocks/herds consisting of highly susceptible animals. Field studies identified scrapie-protective caprine PrP variants, harboring specific single amino acid changes (Met-142, Arg-143, Asp-146, Ser-146, His-154, Gln-211 and Lys-222). Their effects are under further evaluation, and aim to determine the most protective allele. We assessed some of these variants (Asp-146, His-154, Gln-211 and Lys-222), after their exogenous expression as murine-caprine chimeras in a scrapie- infected murine cell line. We report that exogenously expressed PrPs undergo conformational conversion upon interaction with the endogenous pathological murine prion protein (PrP SC ), which results in the detection of goat-specific and partially PK-resistant moieties. These moieties display a PK-resistance pattern distinct from the one detected in natural goat scrapie cases. Within this cellular model, distinct conformational conversion potentials were assigned to the tested variants. Molecules carrying the Asp-146, His-154 and Gln-211 alleles showed significantly lower conversion levels compared to wild type, confirming their protective effects against scrapie. Although we utilized a heterologous conversion system, this is to our knowledge, the first study of caprine PrP variants in a cellular context of scrapie, that confirms the protective effects of some of the studied alleles.

2015-2018 Regional Prevention Plan of Lombardy (Northern Italy) and sedentary prevention: a cross-sectional strategy to develop evidence-based programmes.

PubMed

Coppola, Liliana; Ripamonti, Ennio; Cereda, Danilo; Gelmi, Giusi; Pirrone, Lucia; Rebecchi, Andrea

2016-01-01

Cross-sector, life-course, and setting approaches are identified in the 2015-2018 Regional Prevention Plan (PRP) of Lombardy Region (Northern Italy) as valuable strategies to ensure the efficacy and sustainable prevention of the non-communicable disease (NCDs). The involvement of non-health sectors in health promotion activities represents a suitable strategy to affect on social, economic, and political determinants and to change environmental factors that could cause NCDs. A dialogue among communities, urban planning, and prevention know-how is a prerequisite to develop a system of policies suitable to promote healthy lifestyle in general and, specifically, active lifestyles. The 2015-2018 Lombardy PRP pursues its aims of health promotion and behavioural risk factors for NCDs prevention through programmes that implement their own setting networks (Health Promoting Schools - SPS; Workplace Health Promotion - WHP) and develop new networks. Sedentary lifestyle prevention and active lifestyle promotion are performed through the approach promoted by the Healthy Cities Programme (WHO), encouraging two main processes: 1. creating integrated capacity-building among health and social prevention services, academic research, and local stakeholders on different urban planning and design issues; 2. promoting community empowerment through active citizens participation. Through this process, Lombardy Region aims to orient its services developing evidence-based programmes and enhancing advocacy and mediating capacity skills in order to create a profitable partnership with non-health sectors. This paper reports the main impact data: 26,000 children that reach school by foot thanks to walking buses, 57% of 145 companies joining WHP are involved in promoting physical activity, 18,891 citizens who attend local walking groups.

Correlation between Infectivity and Disease Associated Prion Protein in the Nervous System and Selected Edible Tissues of Naturally Affected Scrapie Sheep

PubMed Central

Chianini, Francesca; Cosseddu, Gian Mario; Steele, Philip; Hamilton, Scott; Hawthorn, Jeremy; Síso, Sílvia; Pang, Yvonne; Finlayson, Jeanie; Eaton, Samantha L.; Reid, Hugh W.; Dagleish, Mark P.; Di Bari, Michele Angelo; D’Agostino, Claudia; Agrimi, Umberto; Terry, Linda; Nonno, Romolo

2015-01-01

The transmissible spongiform encephalopathies (TSEs) or prion diseases are a group of fatal neurodegenerative disorders characterised by the accumulation of a pathological form of a host protein known as prion protein (PrP). The validation of abnormal PrP detection techniques is fundamental to allow the use of high-throughput laboratory based tests, avoiding the limitations of bioassays. We used scrapie, a prototype TSE, to examine the relationship between infectivity and laboratory based diagnostic tools. The data may help to optimise strategies to prevent exposure of humans to small ruminant TSE material via the food chain. Abnormal PrP distribution/accumulation was assessed by immunohistochemistry (IHC), Western blot (WB) and ELISA in samples from four animals. In addition, infectivity was detected using a sensitive bank vole bioassay with selected samples from two of the four sheep and protein misfolding cyclic amplification using bank vole brain as substrate (vPMCA) was also carried out in selected samples from one animal. Lymph nodes, oculomotor muscles, sciatic nerve and kidney were positive by IHC, WB and ELISA, although at levels 100–1000 fold lower than the brain, and contained detectable infectivity by bioassay. Tissues not infectious by bioassay were also negative by all laboratory tests including PMCA. Although discrepancies were observed in tissues with very low levels of abnormal PrP, there was an overall good correlation between IHC, WB, ELISA and bioassay results. Most importantly, there was a good correlation between the detection of abnormal PrP in tissues using laboratory tests and the levels of infectivity even when the titre was low. These findings provide useful information for risk modellers and represent a first step toward the validation of laboratory tests used to quantify prion infectivity, which would greatly aid TSE risk assessment policies. PMID:25807559

Clinical and structural outcomes after arthroscopic repair of full-thickness rotator cuff tears with and without platelet-rich product supplementation: a meta-analysis and meta-regression.

PubMed

Warth, Ryan J; Dornan, Grant J; James, Evan W; Horan, Marilee P; Millett, Peter J

2015-02-01

The purpose of this study was to perform a systematic review, meta-analysis, and meta-regression of all Level I and Level II studies comparing the clinical or structural outcomes, or both, after rotator cuff repair with and without platelet-rich product (PRP) supplementation. A literature search of the PubMed and EMBASE databases was performed to identify all Level I or II studies comparing the clinical or structural outcomes, or both, after arthroscopic repair of full-thickness rotator cuff tears with (PRP+ group) and without (PRP- group) PRP supplementation. Data included outcome scores (American Shoulder and Elbow Surgeons [ASES], University of California Los Angeles [UCLA], Constant, Simple Shoulder Test [SST] and visual analog scale [VAS] scores) and retears diagnosed with imaging studies. Meta-analyses compared preoperative, postoperative, and gain in outcome scores and relative risk ratios for retears. Meta-regression compared the effect of PRP treatment on outcome scores and retear rates according to 6 covariates. Minimum effect sizes that were detectable with 80% power were also calculated for each study. Eleven studies were included in this review and a maximum of 8 studies were used for meta-analyses according to data availability. There were no statistically significant differences between the PRP+ and PRP- groups for overall outcome scores or retear rates (P > .05). Overall gain in the Constant score was decreased when liquid PRP was injected over the tendon surface compared with PRP application at the tendon-bone interface (-6.88 points v +0.78 points, respectively; P = .046); however, this difference did not reach the previously reported minimum clinically important difference (MCID) for Constant scores. When the initial tear size was greater than 3 cm in anterior-posterior length, the PRP+ group exhibited decreased retear rates after double-row repairs when compared with the PRP- group (25.9% v 57.1%, respectively; P = .046). Sensitivity power analyses revealed that most included studies were only powered to detect large differences in outcome scores between groups. There were no statistically significant differences in overall gain in outcome scores or retear rates between treatment groups. Gain in Constant scores was significantly increased when PRPs were applied at the tendon-bone interface when compared with application over the top of the repaired tendon. Retear rates were significantly decreased when PRPs were used for the treatment of tears greater than 3 cm in anterior-posterior length using a double-row technique. Most of the included studies were only powered to detect large differences in outcome scores between treatment groups. In addition, an increased risk for selection, performance, and attrition biases was found. Level II, meta-analysis of Level I and Level II studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Effect of High-Volume Injection, Platelet-Rich Plasma, and Sham Treatment in Chronic Midportion Achilles Tendinopathy: A Randomized Double-Blinded Prospective Study.

PubMed

Boesen, Anders Ploug; Hansen, Rudi; Boesen, Morten Ilum; Malliaras, Peter; Langberg, Henning

2017-07-01

Injection therapies are often considered alongside exercise for chronic midportion Achilles tendinopathy (AT), although evidence of their efficacy is sparse. To determine whether eccentric training in combination with high-volume injection (HVI) or platelet-rich plasma (PRP) injections improves outcomes in AT. Randomized controlled trial; Level of evidence, 1. A total of 60 men (age, 18-59 years) with chronic (>3 months) AT were included and followed for 6 months (n = 57). All participants performed eccentric training combined with either (1) one HVI (steroid, saline, and local anesthetic), (2) four PRP injections each 14 days apart, or (3) placebo (a few drops of saline under the skin). Randomization was stratified for age, function, and symptom severity (Victorian Institute of Sports Assessment-Achilles [VISA-A]). Outcomes included function and symptoms (VISA-A), self-reported tendon pain during activity (visual analog pain scale [VAS]), tendon thickness and intratendinous vascularity (ultrasonographic imaging and Doppler signal), and muscle function (heel-rise test). Outcomes were assessed at baseline and at 6, 12, and 24 weeks of follow-up. VISA-A scores improved in all groups at all time points ( P < .05), with greater improvement in the HVI group (mean ± SEM, 6 weeks = 27 ± 3 points; 12 weeks = 29 ± 4 points) versus PRP (6 weeks = 14 ± 4; 12 weeks = 15 ± 3) and placebo (6 weeks = 10 ± 3; 12 weeks = 11 ± 3) at 6 and 12 weeks ( P < .01) and in the HVI (22 ± 5) and PRP (20 ± 5) groups versus placebo (9 ± 3) at 24 weeks ( P < .01). VAS scores improved in all groups at all time points ( P < .05), with greater decrease in HVI (6 weeks = 49 ± 4 mm; 12 weeks = 45 ± 6 mm; 24 weeks = 34 ± 6 mm) and PRP (6 weeks = 37 ± 7 mm; 12 weeks = 41 ± 7 mm; 24 weeks = 37 ± 6 mm) versus placebo (6 weeks = 23 ± 6 mm; 12 weeks = 30 ± 5 mm; 24 weeks = 18 ± 6 mm) at all time points ( P < .05) and in HVI versus PRP at 6 weeks ( P < .05). Tendon thickness showed a significant decrease only in HVI and PRP groups during the intervention, and this was greater in the HVI versus PRP and placebo groups at 6 and 12 weeks ( P < .05) and in the HVI and PRP groups versus the placebo group at 24 weeks ( P < .05). Muscle function improved in the entire cohort with no difference between the groups. Treatment with HVI or PRP in combination with eccentric training in chronic AT seems more effective in reducing pain, improving activity level, and reducing tendon thickness and intratendinous vascularity than eccentric training alone. HVI may be more effective in improving outcomes of chronic AT than PRP in the short term. Registration: NCT02417987 ( ClinicalTrials.gov identifier).

[Antibacterial effect of autologous platelet-rich gel derived from health volunteers in vitro].

PubMed

Yang, Yanzhi; Liu, Hengchuan; Liu, Guanjian; Ran, Xingwu

2010-05-01

The use of autologous platelet-rich gel (APG) is a relatively new technology and a promising treatment method for infections, which is currently being used by a variety of surgical specialties. The mechanism of antibacterial effect of APG is not yet fully discovered. Subsequent evidence suggests that platelets have multiple functional attributes in antimicrobial host defense (including the capacity to generate antimicrobial oxygen metabolites and the antimicrobial peptides) and interact directly with microorganisms, contribute to clearance of pathogens from the blood. To investigate the bacteriostasis of APG against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa in vitro. Platelet-rich plasma (PRP) and platelet-poor plasma (PPP) were obtained from whole blood of 17 healthy donors. APG was prepared by mixing PRP with bovine thrombin in a 10% calcium gluconate solution or bovine thrombin in a 10% calcium gluconate solution and apocynin (APG-APO). Antibacterial effects of APG, PRP, and APG-APO on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were evaluated by bacteriostasis assay. The culture results showed apparent decrease in the number of Staphylococcus aureus for both APG and APG-APO, which was maximal at first 4 hours and lasted to 24 hours and 8 hours, respectively; showing significant difference (P < 0.05) when compared APG with PRP and PPP, however no significant difference at first 8 hours (P > 0.05) and significant difference at 12 and 24 hours (P < 0.05) when compared APG with APG-APO; showing significant difference at first 4 hours (P < 0.05), no significant difference at 6, 8, 12, and 24 hours when compared APG-APO with PRP and PPP (P > 0.05). The bacteriostasis rates of APG and APG-APO were 27.36%-52.97% and 18.82%-51.52% against Escherichia coli, respectively; showing no significant difference (P > 0.05) when compared with PRP. The bacteriostasis rates of APG and APG-APO were less than 35% against Pseudomonas aeruginosa, showing no significant difference (P > 0.05) when compared with PRP; the bacteriostasis rates of PRP were less than 15% against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. APG may have potential bacteriostatic effect against Staphylococcus aureus by platelet mediating. Either APG or APG-APO has no obvious bacteriostatic effect against Escherichia coli or Pseudomonas aeruginosa. PRP has no antibacterial activity against Staphylococcus aureus, Escherichia coli or Pseudomonas aeruginosa.

In Vitro Approach To Identify Key Amino Acids in Low Susceptibility of Rabbit Prion Protein to Misfolding

PubMed Central

Eraña, Hasier; Fernández-Borges, Natalia; Elezgarai, Saioa R.; Harrathi, Chafik; Charco, Jorge M.; Chianini, Francesca; Dagleish, Mark P.; Ortega, Gabriel; Millet, Óscar

2017-01-01

ABSTRACT Prion diseases, or transmissible spongiform encephalopathies (TSEs), are a group of rare progressive neurodegenerative disorders caused by an abnormally folded prion protein (PrPSc). This is capable of transforming the normal cellular prion protein (PrPC) into new infectious PrPSc. Interspecies prion transmissibility studies performed by experimental challenge and the outbreak of bovine spongiform encephalopathy that occurred in the late 1980s and 1990s showed that while some species (sheep, mice, and cats) are readily susceptible to TSEs, others are apparently resistant (rabbits, dogs, and horses) to the same agent. To study the mechanisms of low susceptibility to TSEs of certain species, the mouse-rabbit transmission barrier was used as a model. To identify which specific amino acid residues determine high or low susceptibility to PrPSc propagation, protein misfolding cyclic amplification (PMCA), which mimics PrPC-to-PrPSc conversion with accelerated kinetics, was used. This allowed amino acid substitutions in rabbit PrP and accurate analysis of misfolding propensities. Wild-type rabbit recombinant PrP could not be misfolded into a protease-resistant self-propagating isoform in vitro despite seeding with at least 12 different infectious prions from diverse origins. Therefore, rabbit recombinant PrP mutants were designed to contain every single amino acid substitution that distinguishes rabbit recombinant PrP from mouse recombinant PrP. Key amino acid residue substitutions were identified that make rabbit recombinant PrP susceptible to misfolding, and using these, protease-resistant misfolded recombinant rabbit PrP was generated. Additional studies characterized the mechanisms by which these critical amino acid residue substitutions increased the misfolding susceptibility of rabbit PrP. IMPORTANCE Prion disorders are invariably fatal, untreatable diseases typically associated with long incubation periods and characteristic spongiform changes associated with neuronal loss in the brain. Development of any treatment or preventative measure is dependent upon a detailed understanding of the pathogenesis of these diseases, and understanding the mechanism by which certain species appear to be resistant to TSEs is critical. Rabbits are highly resistant to naturally acquired TSEs, and even under experimental conditions, induction of clinical disease is not easy. Using recombinant rabbit PrP as a model, this study describes critical molecular determinants that confer this high resistance to transmissible spongiform encephalopathies. PMID:28978705

Sustained transfer of knowledge to practice in long-term care: facilitators and barriers of a mental health learning initiative.

PubMed

Stolee, Paul; McAiney, Carrie A; Hillier, Loretta M; Harris, Diane; Hamilton, Pam; Kessler, Linda; Madsen, Victoria; Le Clair, J Kenneth

2009-01-01

This article explores facilitators and barriers to the impact and sustainability of a learning initiative to increase capacity of long-term care (LTC) homes to manage the mental health needs of older persons, through development of in-house Psychogeriatric Resource Persons (PRPs). Twenty interviews were conducted with LTC staff. Management support, particularly designation of time for PRP activities, development of PRP teams, and supportive learning strategies were significant factors affecting sustained knowledge transfer. Continuing education that is provided and evaluated on an ongoing basis, secures management commitment, is integrated within a broader system strategy, and provides on-the-job support has the greatest potential to affect care.

A shared cortical bottleneck underlying Attentional Blink and Psychological Refractory Period.

PubMed

Marti, Sébastien; Sigman, Mariano; Dehaene, Stanislas

2012-02-01

Doing two things at once is difficult. When two tasks have to be performed within a short interval, the second is sharply delayed, an effect called the Psychological Refractory Period (PRP). Similarly, when two successive visual targets are briefly flashed, people may fail to detect the second target (Attentional Blink or AB). Although AB and PRP are typically studied in very different paradigms, a recent detailed neuromimetic model suggests that both might arise from the same serial stage during which stimuli gain access to consciousness and, as a result, can be arbitrarily routed to any other appropriate processor. Here, in agreement with this model, we demonstrate that AB and PRP can be obtained on alternate trials of the same cross-modal paradigm and result from limitations in the same brain mechanisms. We asked participants to respond as fast as possible to an auditory target T1 and then to a visual target T2 embedded in a series of distractors, while brain activity was recorded with magneto-encephalography (MEG). For identical stimuli, we observed a mixture of blinked trials, where T2 was entirely missed, and PRP trials, where T2 processing was delayed. MEG recordings showed that PRP and blinked trials underwent identical sensory processing in visual occipito-temporal cortices, even including the non-conscious separation of targets from distractors. However, late activations in frontal cortex (>350 ms), strongly influenced by the speed of task-1 execution, were delayed in PRP trials and absent in blinked trials. Our findings suggest that PRP and AB arise from similar cortical stages, can occur with the same exact stimuli, and are merely distinguished by trial-by-trial fluctuations in task processing. Copyright © 2011 Elsevier Inc. All rights reserved.

Platelet-rich plasma for chronic lateral epicondylitis: is one injection sufficient?

PubMed

Glanzmann, Michael C; Audigé, Laurent

2015-12-01

Chronic lateral epicondylitis is generally treated using nonsurgical methods including physiotherapy and infiltrations of cortisone or platelet-rich plasma (PRP). The latter is known for its simple application as well as associated low risk of adverse events, which lend to its widespread use in treating various musculoskeletal conditions. There is limited evidence on the effectiveness of PRP injections to optimally treat chronic lateral epicondylitis. This study explored the effectiveness of single or repeated injections for patients with symptoms that spanned 6 months or more and were unresponsive to alternate conservative measures. Patients with chronic lateral epicondylitis received PRP injections in 4-week intervals that were complemented with standardized physical therapy. Patient-reported outcomes based on the patient-rated elbow evaluation (PREE), quick disabilities of the arm, shoulder and hand (qDASH), and EuroQol (five dimensions) 3-level version (EQ5D3L) questionnaires were documented at each visit including 6 months after the first injection. These outcomes were compared between patients receiving 1 vs. 2 or 3 PRP injections. Sixty-two patients received one (n = 36) or more (n = 26) PRP injections. The mean baseline to 6-month follow-up scores of the PREE and qDASH questionnaires improved significantly from 54.0 to 23.0 and 50.3 to 20.7, respectively. The mean baseline EQ5D3L-visual analogue scale score improved from 62.5 to 82.9 by 6 months post-injection. These outcomes did not significantly differ between the patients who received varying numbers of injections. Patients with chronic lateral epicondylitis reported significant pain relief and gain in function as well as quality of life 6 months after localized PRP treatment. A single PRP injection may be sufficient.

Excitotoxicity through NMDA receptors mediates cerebellar granule neuron apoptosis induced by prion protein 90-231 fragment.

PubMed

Thellung, Stefano; Gatta, Elena; Pellistri, Francesca; Corsaro, Alessandro; Villa, Valentina; Vassalli, Massimo; Robello, Mauro; Florio, Tullio

2013-05-01

Prion diseases recognize, as a unique molecular trait, the misfolding of CNS-enriched prion protein (PrP(C)) into an aberrant isoform (PrP(Sc)). In this work, we characterize the in vitro toxicity of amino-terminally truncated recombinant PrP fragment (amino acids 90-231, PrP90-231), on rat cerebellar granule neurons (CGN), focusing on glutamatergic receptor activation and Ca(2+) homeostasis impairment. This recombinant fragment assumes a toxic conformation (PrP90-231(TOX)) after controlled thermal denaturation (1 h at 53 °C) acquiring structural characteristics identified in PrP(Sc) (enrichment in β-structures, increased hydrophobicity, partial resistance to proteinase K, and aggregation in amyloid fibrils). By annexin-V binding assay, and evaluation of the percentage of fragmented and condensed nuclei, we show that treatment with PrP90-231(TOX), used in pre-fibrillar aggregation state, induces CGN apoptosis. This effect was associated with a delayed, but sustained elevation of [Ca(2+)]i. Both CGN apoptosis and [Ca(2+)]i increase were not observed using PrP90-231 in PrP(C)-like conformation. PrP90-231(TOX) effects were significantly reduced in the presence of ionotropic glutamate receptor antagonists. In particular, CGN apoptosis and [Ca(2+)]i increase were largely reduced, although not fully abolished, by pre-treatment with the NMDA antagonists APV and memantine, while the AMPA antagonist CNQX produced a lower, although still significant, effect. In conclusion, we report that CGN apoptosis induced by PrP90-231(TOX) correlates with a sustained elevation of [Ca(2+)]i mediated by the activation of NMDA and AMPA receptors.

Treatment of Acute Vocal Fold Injury With Platelet-Rich Plasma.

PubMed

Cobden, Serap Bulut; Oztürk, Kayhan; Duman, Selcuk; Esen, Hasan; Aktan, Tahsin Murad; Avunduk, Mustafa Cihat; Elsurer, Cagdas

2016-11-01

Platelet-rich plasma (PRP) is a reliable and has low side-effect profile and has beneficial effects on wound healing. Its investigatory effects on wound-healing process were shown on various tissues. The aim of the present study was to evaluate effectiveness of PRP application on scar tissue of acute vocal fold injury. Twenty-four Wistar rats were used in the study. The entire layer of the lamina propria down to the thyroarytenoid muscle of 10 subjects was unilaterally injured by with a microscissor. Gelfoam-absorbed PRP was applied on the injured area for 10 minutes. Control group consisted of rats unilaterally injured using a microscissor, and gelfoam with normal saline was applied on the injured area. Following sacrifice, the larynxes were carefully dissected and removed for histopathologic examination. After excised larynx experiments, serial sections were prepared from vocal fold. Hematoxylin eosin and immunohistochemical staining were done for epithelial growth factor receptor (EGFR), fibroblast growth factor receptor (FGFR1), and vascular endothelial growth factor (VEGF) staining for histopathologic examinations. There was not a significant difference between the two groups for lymphocyte. Although collagen and VEGF were higher in the study group, there was not a significant difference between the groups (P > 0.05). There was a significant difference between control and study groups for EGFR and FGFR1(P < 0.05). PRP has beneficial effects on wound healing. PRP accelerates epithelization of injured rat vocal folds by inducing EGFR secretion. PRP is an autogenous, reliable, low side-effect profile, easily harvested material. PRP may be useful to prevent scar formation. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Comparison of the platelet-rich plasma and buffy coat protocols for preparation of canine platelet concentrates.

PubMed

Hoareau, Guillaume L; Jandrey, Karl E; Burges, Julie; Bremer, Daphne; Tablin, Fern

2014-12-01

Platelet (PLT) concentrates (PC) can be produced via the buffy coat (BC) or platelet-rich plasma (PRP) protocols. The 2 methods have not been compared with canine blood. The aims of the study were to compare the PLT, WBC, and RBC concentrations, in vitro PLT function, and markers of platelet storage lesion (PSL) in canine PC generated by 2 different protocols, and determine microbial growth throughout storage. PC from 8 healthy donor dogs were produced using 2 standard protocols, PRP and BC. PLT, WBC, and RBC counts, optical aggregometry assays, and PSL markers (pH, pCO2 , HCO3 , lactate and glucose concentrations, and LDH activity) were determined on storage days 0, 1, 3, 5, and 7. Aerobic and anaerobic bacterial cultures were also performed. Mean PLT counts were comparable between protocols and remained stable throughout storage up to day 7, while median WBC and RBC counts on day 0 were significantly higher in the BC-PC group (17,800 WBCs/μL; 195,000 RBCs/μL) than in the PRP-PC group (200 WBCs/μL; 10,000 RBCs/μL) (P = .012). In PRP-PC aggregometry, the median slope and amplitude in response to γ-thrombin and convulxin (+ ADP) were significantly decreased, and virtually absent in BC-PC during storage. PSL markers (lactate, LDH activity) were higher in BC-PC. Aerobic bacterial growth was observed in 2 PRP-PC and 1 BC-PC. This in vitro study suggests that PRP-PC had lesser WBC and RBC contamination and superior PLT function compared with BC-PC. In vivo studies are required to address safety and efficacy of PRP-PC. © 2014 American Society for Veterinary Clinical Pathology.

An evaluation of platelet-rich plasma without thrombin activation with or without anorganic bone mineral in the treatment of human periodontal intrabony defects.

PubMed

Rodrigues, Silvia V; Acharya, Anirudh B; Thakur, Srinath L

2011-01-01

The efficacy of platelet-rich plasma (PRP) in periodontal regeneration is not well understood and the definite clinical viability of blood derived platelets lacks clarity. Also, the use of thrombin for platelet activation is disputed. Hence, the purpose of this study was to evaluate the efficacy of blood derived platelets without thrombin activation, alone or in combination with bovine anorganic bone mineral (ABM), in the treatment of human periodontal intrabony defects. PRP was prepared using a simple tabletop centrifuge and activated using calcium chloride without the addition of thrombin. This PRP was used alone (in Group A) and in combination with bovine ABM (in Group B) in the treatment of human periodontal angular defects. Both the control and the test groups showed definite improvement in clinical parameters. On comparison, however, there was a statistically significant improvement in the probing pocket depths and relative attachment level in Group B over Group A at 3 and 6 months intervals, whereas at the end of 9 months this difference was not statistically significant. There was no statistically significant difference between the groups with respect to the relative defect depth. Within the limitations of this study and the type of PRP used, i.e. without thrombin mediated activation, it can be concluded that both PRP and PRP combined with bovine ABM results in significant clinical improvement. Albeit statistically insignificant, there is a preponderance of better clinical results with the addition of ABM to PRP. Further studies need to be carried out on a larger sample size to confirm the results of the present study.

Effects of the Pathogenic Mutation A117V and the Protective Mutation H111S on the Folding and Aggregation of PrP106-126: Insights from Replica Exchange Molecular Dynamics Simulations.

PubMed

Ning, Lulu; Pan, Dabo; Zhang, Yan; Wang, Shaopeng; Liu, Huanxiang; Yao, Xiaojun

2015-01-01

The fragment 106-126 of prion protein exhibits similar properties to full-length prion. Experiments have shown that the A117V mutation enhances the aggregation of PrP106-126, while the H111S mutation abolishes the assembly. However, the mechanism of the change in the aggregation behavior of PrP106-126 upon the two mutations is not fully understood. In this study, replica exchange molecular dynamics simulations were performed to investigate the conformational ensemble of the WT PrP106-126 and its two mutants A117V and H111S. The obtained results indicate that the three species are all intrinsically disordered but they have distinct morphological differences. The A117V mutant has a higher propensity to form β-hairpin structures than the WT, while the H111S mutant has a higher population of helical structures. Furthermore, the A117V mutation increases the hydrophobic solvent accessible surface areas of PrP106-126 and the H111S mutation reduces the exposure of hydrophobic residues. It can be concluded that the difference in populations of β-hairpin structures and the change of hydrophobic solvent accessible areas may induce the different aggregation behaviors of the A117V and the H111S mutated PrP106-126. Understanding why the two mutations have contrary effects on the aggregation of PrP106-126 is very meaningful for further elucidation of the mechanism underlying aggregation and design of inhibitor against aggregation process.

Effects of the Pathogenic Mutation A117V and the Protective Mutation H111S on the Folding and Aggregation of PrP106-126: Insights from Replica Exchange Molecular Dynamics Simulations

PubMed Central

Ning, Lulu; Pan, Dabo; Zhang, Yan; Wang, Shaopeng; Liu, Huanxiang; Yao, Xiaojun

2015-01-01

The fragment 106-126 of prion protein exhibits similar properties to full-length prion. Experiments have shown that the A117V mutation enhances the aggregation of PrP106-126, while the H111S mutation abolishes the assembly. However, the mechanism of the change in the aggregation behavior of PrP106-126 upon the two mutations is not fully understood. In this study, replica exchange molecular dynamics simulations were performed to investigate the conformational ensemble of the WT PrP106-126 and its two mutants A117V and H111S. The obtained results indicate that the three species are all intrinsically disordered but they have distinct morphological differences. The A117V mutant has a higher propensity to form β-hairpin structures than the WT, while the H111S mutant has a higher population of helical structures. Furthermore, the A117V mutation increases the hydrophobic solvent accessible surface areas of PrP106-126 and the H111S mutation reduces the exposure of hydrophobic residues. It can be concluded that the difference in populations of β-hairpin structures and the change of hydrophobic solvent accessible areas may induce the different aggregation behaviors of the A117V and the H111S mutated PrP106-126. Understanding why the two mutations have contrary effects on the aggregation of PrP106-126 is very meaningful for further elucidation of the mechanism underlying aggregation and design of inhibitor against aggregation process. PMID:25993001

Pooled thrombin-activated platelet-rich plasma: a substitute for fetal bovine serum in the engineering of osteogenic/vasculogenic grafts.

PubMed

Tchang, Laurent A; Pippenger, Benjamin E; Todorov, Atanas; Wolf, Francine; Burger, Maximilian G; Jaquiery, Claude; Bieback, Karen; Martin, Ivan; Schaefer, Dirk J; Scherberich, Arnaud

2017-05-01

The use of fetal bovine serum (FBS) as a culture medium supplement in cell therapy and clinical tissue engineering is challenged by immunological concerns and the risk of disease transmission. Here we tested whether human, thrombin-activated, pooled, platelet-rich plasma (tPRP) can be substituted for FBS in the engineering of osteogenic and vasculogenic grafts, using cells from the stromal vascular fraction (SVF) of human adipose tissue. SVF cells were cultured under perfusion flow into porous hydroxyapatite scaffolds for 5 days, with the medium supplemented with either 10% tPRP or 10% FBS and implanted in an ectopic mouse model. Following in vitro culture, as compared to FBS, the use of tPRP did not modify the fraction of clonogenic cells or the different cell phenotypes, but increased by 1.9-fold the total number of cells. After 8 weeks in vivo, bone tissue was formed more reproducibly and in higher amounts (3.7-fold increase) in constructs cultured with tPRP. Staining for human-specific ALU sequences and for the human isoforms of CD31/CD34 revealed the human origin of the bone, the formation of blood vessels by human vascular progenitors and a higher density of human cells in implants cultured with tPRP. In summary, tPRP supports higher efficiency of bone formation by SVF cells than FBS, likely by enhancing cell expansion in vitro while maintaining vasculogenic properties. The use of tPRP may facilitate the clinical translation of osteogenic grafts with intrinsic capacity for vascularization, based on the use of adipose-derived cells. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

A small molecule modulator of prion protein increases human mesenchymal stem cell lifespan, ex vivo expansion, and engraftment to bone marrow in NOD/SCID mice.

PubMed

Mohanty, Sindhu T; Cairney, Claire J; Chantry, Andrew D; Madan, Sanjeev; Fernandes, James A; Howe, Steven J; Moore, Harry D; Thompson, Mark J; Chen, Beining; Thrasher, Adrian; Keith, W Nicol; Bellantuono, Ilaria

2012-06-01

Human mesenchymal stem cells (hMSCs) have been shown to have potential in regenerative approaches in bone and blood. Most protocols rely on their in vitro expansion prior to clinical use. However, several groups including our own have shown that hMSCs lose proliferation and differentiation ability with serial passage in culture, limiting their clinical applications. Cellular prion protein (PrP) has been shown to enhance proliferation and promote self-renewal of hematopoietic, mammary gland, and neural stem cells. Here we show, for the first time, that expression of PrP decreased in hMSC following ex vivo expansion. When PrP expression was knocked down, hMSC showed significant reduction in proliferation and differentiation. In contrast, hMSC expanded in the presence of small molecule 3/689, a modulator of PrP expression, showed retention of PrP expression with ex vivo expansion and extended lifespan up to 10 population doublings. Moreover, cultures produced a 300-fold increase in the number of cells generated. These cells showed a 10-fold increase in engraftment levels in bone marrow 5 weeks post-transplant. hMSC treated with 3/689 showed enhanced protection from DNA damage and enhanced cell cycle progression, in line with data obtained by gene expression profiling. Moreover, upregulation of superoxide dismutase-2 (SOD2) was also observed in hMSC expanded in the presence of 3/689. The increase in SOD2 was dependent on PrP expression and suggests increased scavenging of reactive oxygen species as mechanism of action. These data point to PrP as a good target for chemical intervention in stem cell regenerative medicine. Copyright © 2012 AlphaMed Press.

Greater Trochanteric Pain Syndrome: Percutaneous Tendon Fenestration Versus Platelet-Rich Plasma Injection for Treatment of Gluteal Tendinosis.

PubMed

Jacobson, Jon A; Yablon, Corrie M; Henning, P Troy; Kazmers, Irene S; Urquhart, Andrew; Hallstrom, Brian; Bedi, Asheesh; Parameswaran, Aishwarya

2016-11-01

The purpose of this study was to compare ultrasound-guided percutaneous tendon fenestration to platelet-rich plasma (PRP) injection for treatment of greater trochanteric pain syndrome. After Institutional Review Board approval was obtained, patients with symptoms of greater trochanteric pain syndrome and ultrasound findings of gluteal tendinosis or a partial tear (<50% depth) were blinded and treated with ultrasound-guided fenestration or autologous PRP injection of the abnormal tendon. Pain scores were recorded at baseline, week 1, and week 2 after treatment. Retrospective clinic record review assessed patient symptoms. The study group consisted of 30 patients (24 female), of whom 50% were treated with fenestration and 50% were treated with PRP. The gluteus medius was treated in 73% and 67% in the fenestration and PRP groups, respectively. Tendinosis was present in all patients. In the fenestration group, mean pain scores were 32.4 at baseline, 16.8 at time point 1, and 15.2 at time point 2. In the PRP group, mean pain scores were 31.4 at baseline, 25.5 at time point 1, and 19.4 at time point 2. Retrospective follow-up showed significant pain score improvement from baseline to time points 1 and 2 (P< .0001) but no difference between treatment groups (P= .1623). There was 71% and 79% improvement at 92 days (mean) in the fenestration and PRP groups, respectively, with no significant difference between the treatments (P >.99). Our study shows that both ultrasound-guided tendon fenestration and PRP injection are effective for treatment of gluteal tendinosis, showing symptom improvement in both treatment groups. © 2016 by the American Institute of Ultrasound in Medicine.

[Autogenous platelet-rich plasma gel with acellular xenogeneic dermal matrix for treatment of deep II degree burns].

PubMed

Hao, Tianzhi; Zhu, Jingmin; Hu, Wenbo; Zhang, Hua; Gao, Zhenhui; Wen, Xuehui; Zhou, Zhi; Lu, Gang; Liu, Jingjie; Li, Wen

2010-06-01

To investigate the effectiveness of autogenous platelet-rich plasma (PRP) gel with acellular xenogeneic dermal matrix in the treatment of deep II degree burns. From January 2007 to December 2009, 30 cases of deep II degree burns were treated. There were 19 males and 11 females with an average age of 42.5 years (range, 32-57 years). The burn area was 10% to 48% of total body surface area. The time from burn to hospitalization was 30 minutes to 8 hours. All patients were treated with tangential excision surgery, one side of the wounds were covered with autogenous PRP gel and acellular xenogeneic dermal matrix (PRP group), the other side of the wounds were covered with acellular xenogeneic dermal matrix only (control group). The healing rate, healing time, infection condition, and scar formation were observed. At 7 days after operation, the infection rate in PRP group (6.7%, 2/30) was significantly lower than that in control group (16.7%, 5/30, P < 0.05). The healing times were (18 +/- 4) days and (22 +/- 4) days respectively in PRP group and control group, showing significant difference (P < 0.05). The healing rates at 14 days and 21 days were 75% +/- 7% and 88% +/- 5% in PRP group, were 62% +/- 15% and 73% +/- 7% in control group, showing significant difference (P < 0.05). RPR group was superior to control group in elasticity, color, appearance, softness, scar formation, and healing quality. Autogenous PRP gel with acellular xenogeneic dermal matrix can accelerate the wound healing of deep II degree burns as well as alleviate the scar proliferation.

Structural basis for dual roles of Aar2p in U5 snRNP assembly

PubMed Central

Weber, Gert; Cristão, Vanessa F.; Santos, Karine F.; Jovin, Sina Mozaffari; Heroven, Anna C.; Holton, Nicole; Lührmann, Reinhard; Beggs, Jean D.; Wahl, Markus C.

2013-01-01

Yeast U5 small nuclear ribonucleoprotein particle (snRNP) is assembled via a cytoplasmic precursor that contains the U5-specific Prp8 protein but lacks the U5-specific Brr2 helicase. Instead, pre-U5 snRNP includes the Aar2 protein not found in mature U5 snRNP or spliceosomes. Aar2p and Brr2p bind competitively to a C-terminal region of Prp8p that comprises consecutive RNase H-like and Jab1/MPN-like domains. To elucidate the molecular basis for this competition, we determined the crystal structure of Aar2p in complex with the Prp8p RNase H and Jab1/MPN domains. Aar2p binds on one side of the RNase H domain and extends its C terminus to the other side, where the Jab1/MPN domain is docked onto a composite Aar2p–RNase H platform. Known Brr2p interaction sites of the Jab1/MPN domain remain available, suggesting that Aar2p-mediated compaction of the Prp8p domains sterically interferes with Brr2p binding. Moreover, Aar2p occupies known RNA-binding sites of the RNase H domain, and Aar2p interferes with binding of U4/U6 di-snRNA to the Prp8p C-terminal region. Structural and functional analyses of phospho-mimetic mutations reveal how phosphorylation reduces affinity of Aar2p for Prp8p and allows Brr2p and U4/U6 binding. Our results show how Aar2p regulates both protein and RNA binding to Prp8p during U5 snRNP assembly. PMID:23442228

Biologic agents for anterior cruciate ligament healing: A systematic review

PubMed Central

Di Matteo, Berardo; Loibl, Markus; Andriolo, Luca; Filardo, Giuseppe; Zellner, Johannes; Koch, Matthias; Angele, Peter

2016-01-01

AIM To systematically review the currently available literature concerning the application of biologic agents such as platelet-rich plasma (PRP) and stem cells to promote anterior cruciate ligament (ACL) healing. METHODS A systematic review of the literature was performed on the use of biologic agents (i.e., PRP or stem cells) to favor ACL healing during reconstruction or repair. The following inclusion criteria for relevant articles were used: Clinical reports of any level of evidence, written in English language, on the use of PRP or stem cells during ACL reconstruction/repair. Exclusion criteria were articles written in other languages, reviews, or studies analyzing other applications of PRP/stem cells in knee surgery not related to promoting ACL healing. RESULTS The database search identified 394 records that were screened. A total of 23 studies were included in the final analysis: In one paper stem cells were applied for ACL healing, in one paper there was a concomitant application of PRP and stem cells, whereas in the remaining 21 papers PRP was used. Based on the ACL injury pattern, two papers investigated biologic agents in ACL partial tears whereas 21 papers in ACL reconstruction. Looking at the quality of the available literature, 17 out of 21 studies dealing with ACL reconstruction were randomized controlled trials. Both studies on ACL repair were case series. CONCLUSION There is a paucity of clinical trials investigating the role of stem cells in promoting ACL healing both in case of partial and complete tears. The role of PRP is still controversial and the only advantage emerging from the literature is related to a better graft maturation over time, without documenting beneficial effects in terms of clinical outcome, bone-graft integration and prevention of bony tunnel enlargement. PMID:27672573

Polymorphism analysis of prion protein gene in 11 Pakistani goat breeds

PubMed Central

Hassan, Mohammad Farooque; Khan, Sher Hayat; Babar, Masroor Ellahi; Yang, Lifeng; Ali, Tariq; Khan, Jamal Muhammad; Shah, Syed Zahid Ali; Zhou, Xiangmei; Hussain, Tanveer; Zhu, Ting; Hussain, Tariq; Zhao, Deming

2016-01-01

ABSTRACT The association between caprine PrP gene polymorphisms and its susceptibility to scrapie has been investigated in current years. As the ORF of the PrP gene is extremely erratic in different breeds of goats, we studied the PrP gene polymorphisms in 80 goats which belong to 11 Pakistani indigenous goat breeds from all provinces of Pakistan. A total of 6 distinct polymorphic sites (one novel) with amino acid substitutions were identified in the PrP gene which includes 126 (A -> G), 304 (G -> T), 379 (A -> G), 414 (C -> T), 428 (A -> G) and 718 (C -> T). The locus c.428 was found highly polymorphic in all breeds as compare to other loci. On the basis of these PrP variants NJ phylogenetic tree was constructed through MEGA6.1 which showed that all goat breeds along with domestic sheep and Mauflon sheep appeared as in one clade and sharing its most recent common ancestors (MRCA) with deer species while Protein analysis has shown that these polymorphisms can lead to varied primary, secondary and tertiary structure of protein. Based on these polymorphic variants, genetic distance, multidimensional scaling plot and principal component analyses revealed the clear picture regarding greater number of substitutions in cattle PrP regions as compared to the small ruminant species. In particular these findings may pinpoint the fundamental control over the scrapie in Capra hircus on genetic basis. PMID:27388702

Assessment of the efficacy and safety of single platelet-rich plasma injection on different types and grades of facial wrinkles.

PubMed

Elnehrawy, Naema Y; Ibrahim, Zeinab A; Eltoukhy, Azza M; Nagy, Hala M

2017-03-01

Platelet-rich plasma (PRP) is considered as a growing modality for tissue regeneration and a developing research area for clinicians and researchers. PRP injection treatment provides supraphysiological concentrations of growth factors that may help in accelerated tissue remodeling and regeneration. To evaluate the efficacy and safety of single autologous PRP intradermal injection for treatment of facial wrinkles and for facial rejuvenation. A total of 20 subjects with different types of facial wrinkles were included in this study. All subjects received single PRP intradermal injection and were clinically assessed before and after treatment for a period of 8 weeks using Wrinkle Severity Rating Scale (WSRS), Skin Homogeneity and Texture (SHnT) Scale, Physician Assessment Scale, and Subject Satisfaction Scale. The mean value of WSRS reduced from 2.90 ± 0.91 before treatment to 2.10 ± 0.79 after 8 weeks of treatment. The most significant results were with younger subjects that have mild and moderate wrinkles of the nasolabial folds (NLFs). Fourteen of seventeen subjects with NLFs showed more than 25% improvement in their appearance. Side effects of PRP treatment were minimal to mild and with excellent tolerability. Single PRP intradermal injection is well tolerated and capable of rejuvenating the face and producing a significant correction of wrinkles especially the NLFs. © 2016 Wiley Periodicals, Inc.

Tissue Engineering for Rotator Cuff Repair: An Evidence-Based Systematic Review

PubMed Central

Maffulli, Nicola; Longo, Umile Giuseppe; Loppini, Mattia; Berton, Alessandra; Spiezia, Filippo; Denaro, Vincenzo

2012-01-01

The purpose of this systematic review was to address the treatment of rotator cuff tears by applying tissue engineering approaches to improve tendon healing, specifically platelet rich plasma (PRP) augmentation, stem cells, and scaffolds. Our systematic search was performed using the combination of the following terms: “rotator cuff”, “shoulder”, “PRP”, “platelet rich plasma”, “stemcells”, “scaffold”, “growth factors”, and “tissue engineering”. No level I or II studies were found on the use of scaffolds and stem cells for rotator cuff repair. Three studies compared rotator cuff repair with or without PRP augmentation. All authors performed arthroscopic rotator cuff repair with different techniques of suture anchor fixation and different PRP augmentation. The three studies found no difference in clinical rating scales and functional outcomes between PRP and control groups. Only one study showed clinical statistically significant difference between the two groups at the 3-month follow up. Any statistically significant difference in the rates of tendon rerupture between the control group and the PRP group was found using the magnetic resonance imaging. The current literature on tissue engineering application for rotator cuff repair is scanty. Comparative studies included in this review suggest that PRP augmented repair of a rotator cuff does not yield improved functional and clinical outcome compared with non-augmented repair at a medium and long-term followup. PMID:25098365

Superoxide dismutase activity of Cu-bound prion protein

NASA Astrophysics Data System (ADS)

Hodak, Miroslav; Lu, Wenchang; Bernholc, Jerry

2009-03-01

Misfolding of the prion protein, PrP, has been linked to a group of neurodegenerative diseases, including the mad cow disease in cattle and the Creutzfeldt-Jakob disease in humans. The normal function of PrP is still unknown, but it was found that the PrP can efficiently bind Cu(II) ions. Early experiments suggested that Cu-PrP complex possesses significant superoxide dismutase (SOD) activity, but later experiments failed to confirm it and at present this issue remains unresolved. Using a recently developed hybrid DFT/DFT method, which combines Kohn-Sham DFT for the solute and its first solvation shells with orbital-free DFT for the remainder of the solvent, we have investigated SOD activity of PrP. The PrP is capable of incorporating Cu(II) ions in several binding modes and our calculations find that each mode has a different SOD activity. The highest activity found is comparable to those of well-known SOD proteins, suggesting that the conflicting experimental results may be due to different bindings of Cu(II) in those experiments.

A stretch of residues within the protease-resistant core is not necessary for prion structure and infectivity.

PubMed

Munoz-Montesino, Carola; Sizun, Christina; Moudjou, Mohammed; Herzog, Laetitia; Reine, Fabienne; Igel-Egalon, Angelique; Barbereau, Clément; Chapuis, Jérôme; Ciric, Danica; Laude, Hubert; Béringue, Vincent; Rezaei, Human; Dron, Michel

2017-01-02

Mapping out regions of PrP influencing prion conversion remains a challenging issue complicated by the lack of prion structure. The portion of PrP associated with infectivity contains the α-helical domain of the correctly folded protein and turns into a β-sheet-rich insoluble core in prions. Deletions performed so far inside this segment essentially prevented the conversion. Recently we found that deletion of the last C-terminal residues of the helix H2 was fully compatible with prion conversion in the RK13-ovPrP cell culture model, using 3 different infecting strains. This was in agreement with preservation of the overall PrP C structure even after removal of up to one-third of this helix. Prions with internal deletion were infectious for cells and mice expressing the wild-type PrP and they retained prion strain-specific characteristics. We thus identified a piece of the prion domain that is neither necessary for the conformational transition of PrP C nor for the formation of a stable prion structure.

The pathological prion protein forms ionic conductance in lipid bilayer.

PubMed

Paulis, Daniele; Maras, Bruno; Schininà, M Eugenia; di Francesco, Laura; Principe, Serena; Galeno, Roberta; Abdel-Haq, Hanin; Cardone, Franco; Florio, Tullio; Pocchiari, Maurizio; Mazzanti, Michele

2011-08-01

Transmissible spongiform encephalopathies (TSEs) are neurodegenerative pathologies characterized by the accumulation of amyloid fibrils mainly composed of the pathological isoform of the prion protein (PrP(TSE)). PrP(TSE) pre-amyloid fibrils are supposed to induce neurodegenerative lesions possibly through the alteration of membrane permeability. The effect of PrP(TSE) on cellular membranes has been modeled in vitro by synthetic peptides that are, however, only partially representative of PrP(TSE) isoforms found in vivo. In the present work we show that a synthetic membrane exposed to PrP27-30 extracted from TSE-infected hamster brains changes its permeability because of the formation of molecular pores that alter the conductance of the synthetic lipid bilayer. Synthetic membrane challenged with the recombinant prion peptide PrP90-231 shows a much lower conductance. Elevation of calcium ion concentration not only increases the current amplitude due to the action of both PrP27-30 and PrP90-231 on the membrane, but also amplifies the interaction of PrP90-231 with the lipid bilayer. Copyright © 2011 Elsevier B.V. All rights reserved.

An Investigation of the Hypotheses for Formation of the Platy-Ridged Terrain in Elysium Planitia, Mars

NASA Astrophysics Data System (ADS)

Yue, Z.; Gou, S.; Michael, G.; Di, K.; Xie, H.; Gong, H.; Shao, Y.

2017-07-01

The origin of the platy-ridged-polygonized (PRP) terrains on Martian surface has long been debated. The terrain has generally been classified as water, pack ice, or basalt lava related flow. The crater counting results of the PRP terrains suggest they are geologically very young; therefore, they are significant in understanding the recent evolution of Mars. This work evaluated the current hypotheses through detailed analysis of the distribution and microtopographies with the High Resolution Imaging Science Experiment (HiRISE) images for the PRP terrains in Elysium Planitia, Mars. Quantitative measurements and statistics of the typical features of the PRP terrains were also made. In addition, we also found an analog site in Tarim Basin in Xinjiang, China. Our results suggest that mud flow is responsible for the formation of the PRP terrains on the Mars surface, although the hypothesis of low-viscosity basalt lava floods cannot be completely excluded. This finding implies that a regional environment suitable for liquid water may have existed in recent geologic time, which has great importance for future Mars scientific exploration.

A study to compare the efficacy of corticosteroid therapy with platelet-rich plasma therapy in recalcitrant plantar fasciitis: a preliminary report.

PubMed

Shetty, Vijay D; Dhillon, Mandeep; Hegde, Chintan; Jagtap, Prajyot; Shetty, Suvin

2014-03-01

Plantar fasciitis is one of the commonest, and most frustrating, foot ailments seen in a regular orthopaedic clinic. There are a number of modalities available to treat this condition, of which corticosteroid injection is, perhaps, the most popular. However, recent years have seen an increased interest in the use of platelet-rich plasma (PRP) injections in various clinical situations such as plantar fasciitis. We undertook a prospective non-randomized study to compare the efficacy of traditional corticosteroid injection (Steroid group) to PRP injection (PRP group), in a cohort of patients. We studied both groups of patients before and after the injections using Visual Analogue Score (VAS), the Foot & Ankle Disability Index (FADI) and American Foot and Ankle Score (AFAS). Our study confirms that there is significant clinical improvement in PRP group at three months after the injection. The use of PRP injection can be an attractive alternative in the treatment of disabling, recalcitrant plantar fasciitis. Cohort study. Level 3. Copyright © 2013 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Prion protein is essential for diabetic retinopathy-associated neovascularization.

PubMed

Zhu, Lingyan; Xu, Jixiong; Liu, Ying; Gong, Tian; Liu, Jianying; Huang, Qiong; Fischbach, Shane; Zou, Wenquan; Xiao, Xiangwei

2018-05-30

Diabetic retinopathy (DR), a major complication of diabetes caused by vascular damage and pathological proliferation of retinal vessels, often progresses to vision loss. Vascular endothelial growth factor (VEGF) signaling plays a pivotal role in the development of DR, but the exact underlying molecular mechanisms remain ill-defined. Cellular prion protein (PrP c ) is a surface protein expressed by vascular endothelial cells, and the increased expression of PrP c is associated with physiological and pathological vascularization. Nevertheless, a role for PrP c in the development of DR has not been appreciated. Here, we addressed this question. We found that the development of streptozocin (STZ)-induced DR, but not the STZ-induced hyperglycemia/diabetes itself, was significantly attenuated in PrP c -KO mice, compared to control wildtype (WT) mice, evident by measurement of retinal vascular leakage, retinal neovascularization, a retinopathy score and visual acuity assessment. Moreover, the attenuation of DR severity seemingly resulted from attenuation of retinal neovascularization via VEGF/ras/rac signaling. Together, our study suggests a previously unappreciated role for PrP c in the development of DR.

PRP: The Proven Solution for Cleaning Up Oil Spills

NASA Technical Reports Server (NTRS)

2006-01-01

The basic technology behind PRP is thousands of microcapsules, tiny balls of beeswax with hollow centers. Water cannot penetrate the microcapsule s cell, but oil is absorbed right into the beeswax spheres as they float on the water s surface. This way, the contaminants, chemical compounds that originally come from crude oil such as fuels, motor oils, or petroleum hydrocarbons, are caught before they settle. PRP works well as a loose powder for cleaning up contaminants in lakes and other ecologically fragile areas. The powder can be spread over a contaminated body of water or soil, and it will absorb contaminants, contain them in isolation, and dispose of them safely. In water, it is important that PRP floats and keeps the oil on the surface, because, even if oil exposure is not immediately lethal, it can cause long-term harm if allowed to settle. Bottom-dwelling fish exposed to compounds released after oil spills may develop liver disease, in addition to reproductive and growth problems. This use of PRP is especially effective for environmental cleanup in sensitive areas like coral reefs and mangroves.

A Highly Toxic Cellular Prion Protein Induces a Novel, Nonapoptotic Form of Neuronal Death

PubMed Central

Christensen, Heather M.; Dikranian, Krikor; Li, Aimin; Baysac, Kathleen C.; Walls, Ken C.; Olney, John W.; Roth, Kevin A.; Harris, David A.

2010-01-01

Several different deletions within the N-terminal tail of the prion protein (PrP) induce massive neuronal death when expressed in transgenic mice. This toxicity is dose-dependently suppressed by coexpression of full-length PrP, suggesting that it results from subversion of a normal physiological activity of cellular PrP. We performed a combined biochemical and morphological analysis of Tg(ΔCR) mice, which express PrP carrying a 21-aa deletion (residues 105-125) within a highly conserved region of the protein. Death of cerebellar granule neurons in Tg(ΔCR) mice is not accompanied by activation of either caspase-3 or caspase-8 or by increased levels of the autophagy marker, LC3-II. In electron micrographs, degenerating granule neurons displayed a unique morphology characterized by heterogeneous condensation of the nuclear matrix without formation of discrete chromatin masses typical of neuronal apoptosis. Our data demonstrate that perturbations in PrP functional activity induce a novel, nonapoptotic, nonautophagic form of neuronal death whose morphological features are reminiscent of those associated with excitotoxic stress. PMID:20472884

Amyloid-β nanotubes are associated with prion protein-dependent synaptotoxicity

PubMed Central

Nicoll, Andrew J.; Panico, Silvia; Freir, Darragh B.; Wright, Daniel; Terry, Cassandra; Risse, Emmanuel; Herron, Caroline E.; O’Malley, Tiernan; Wadsworth, Jonathan D. F.; Farrow, Mark A.; Walsh, Dominic M.; Saibil, Helen R.; Collinge, John

2013-01-01

Growing evidence suggests water-soluble, non-fibrillar forms of amyloid-β protein (Aβ) have important roles in Alzheimer’s disease with toxicities mimicked by synthetic Aβ1–42. However, no defined toxic structures acting via specific receptors have been identified and roles of proposed receptors, such as prion protein (PrP), remain controversial. Here we quantify binding to PrP of Aβ1–42 after different durations of aggregation. We show PrP-binding and PrP-dependent inhibition of long-term potentiation (LTP) correlate with the presence of protofibrils. Globular oligomers bind less avidly to PrP and do not inhibit LTP, whereas fibrils inhibit LTP in a PrP-independent manner. That only certain transient Aβ assemblies cause PrP-dependent toxicity explains conflicting reports regarding the involvement of PrP in Aβ-induced impairments. We show that these protofibrils contain a defined nanotubular structure with a previously unidentified triple helical conformation. Blocking the formation of Aβ nanotubes or their interaction with PrP might have a role in treatment of Alzheimer’s disease. PMID:24022506

14 CFR § 1214.504 - Screening requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... § 1214.504 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Mission... persons who are certified under the PRP will have unescorted access to mission critical space systems... regulation provides for unescorted access to mission critical space systems areas, it does not preclude the...

The Effect of Platelet-Rich Plasma in Hair Regrowth: A Randomized Placebo-Controlled Trial.

PubMed

Gentile, Pietro; Garcovich, Simone; Bielli, Alessandra; Scioli, Maria Giovanna; Orlandi, Augusto; Cervelli, Valerio

2015-11-01

Platelet-rich plasma (PRP) has emerged as a new treatment modality in regenerative plastic surgery, and preliminary evidence suggests that it might have a beneficial role in hair regrowth. Here, we report the results of a randomized, evaluator-blinded, placebo-controlled, half-head group study to compare, with the aid of computerized trichograms, hair regrowth with PRP versus placebo. The safety and clinical efficacy of autologous PRP injections for pattern hair loss were investigated. PRP, prepared from a small volume of blood, was injected on half of the selected patients' scalps with pattern hair loss. The other half was treated with placebo. Three treatments were administered to each patient at 30-day intervals. The endpoints were hair regrowth, hair dystrophy as measured by dermoscopy, burning or itching sensation, and cell proliferation as measured by Ki67 evaluation. Patients were followed for 2 years. Of the 23 patients enrolled, 3 were excluded. At the end of the 3 treatment cycles, the patients presented clinical improvement in the mean number of hairs, with a mean increase of 33.6 hairs in the target area, and a mean increase in total hair density of 45.9 hairs per cm² compared with baseline values. No side effects were noted during treatment. Microscopic evaluation showed the increase of epidermis thickness and of the number of hair follicles 2 weeks after the last PRP treatment compared with baseline value (p < .05). We also observed an increase of Ki67(+) keratinocytes in the epidermis and of hair follicular bulge cells, and a slight increase of small blood vessels around hair follicles in the treated skin compared with baseline (p < .05). Relapse of androgenic alopecia was not evaluated in all patients until 12 months after the last treatment. After 12 months, 4 patients reported progressive hair loss; this was more evident 16 months after the last treatment. Those four patients were re-treated. Our data clearly highlight the positive effects of PRP injections on male pattern hair loss and absence of major side effects. PRP may serve as a safe and effective treatment option against hair loss; more extensive controlled studies are needed. Platelet-rich plasma (PRP) has emerged as a new treatment modality in regenerative plastic surgery, and preliminary evidence suggests that it might have a beneficial role in hair regrowth. Here, the results of a randomized, placebo-controlled, half-head group study to compare the hair regrowth with PRP versus placebo are reported. Hair regrowth was quantified by a blinded evaluator using computerized trichograms. The safety and clinical efficacy of autologous PRP injections for pattern hair loss were investigated. Of the 23 patients enrolled, 3 were excluded. At the end of the 3 treatment cycles, the patients presented clinical improvement in the mean number of hairs, with a mean increase of 33.6 hairs in the target area and a mean increase in total hair density of 45.9 hairs per cm² compared with baseline values. No side effects were noted during treatment. The data clearly highlight the positive effects of PRP injections on male pattern hair loss and absence of major side effects. PRP may serve as a safe and effective treatment option against hair loss; more extensive controlled studies are needed. ©AlphaMed Press.

Platelet-rich plasma to treat experimentally-induced skin wounds in animals: A systematic review and meta-analysis.

PubMed

Tambella, Adolfo Maria; Attili, Anna Rita; Dupré, Gilles; Cantalamessa, Andrea; Martin, Stefano; Cuteri, Vincenzo; Marcazzan, Sabrina; Del Fabbro, Massimo

2018-01-01

The objective of the study was to review current literature to determine whether the topical application of platelet-rich plasma (PRP) promotes healing in experimentally-induced full-thickness skin wounds in animals. The hypothesis was that the adjunct of PRP has a positive effect on wound healing. An electronic search was carried out on the following databases: Web of Science, Cochrane Library, PubMed, Research Gate, Cochrane Wounds Group, Veterinary Information Network. No publication date nor language restrictions were applied. Randomised and not randomised controlled clinical trials comparing PRP with placebo or with other treatments were included. The reduction of open wound area in PRP-treated (test) wounds compared to control wounds was the primary outcome. Secondary outcomes were healing time and number of healed cases in test group compared to control. The following effect sizes were calculated: the Hedges' g for continuous variables; the odds ratio for binary data. Eighteen controlled clinical trials were included in the qualitative and quantitative synthesis, with a total of 661 wounds. All studies were published in the period 2007-2016. Eight studies were carried out on rodent/lagomorph mammals and 10 on non-rodent/lagomorph mammals. In all included studies, control wounds underwent placebo or were left untreated. The PRP group showed a better healing performance than the control group in each outcome. The effect size was statistically significant considering the primary outcome and the overall aggregation of the three outcomes. The effect size, although in favour of the treatment with PRP, was not significant considering the healing time and the number of healings. The overall heterogeneity was mild or moderate. Five studies reported a high risk of selection bias. The publication bias was always mild or absent. The results support the hypothesis of the positive effects of the PRP when compared to control groups in the treatment of experimentally-induced full-thickness skin wounds in animals. PRP can therefore be considered an effective adjunctive therapy in stimulating second intention healing of acute wounds in healthy animals.

Use of Platelet-Rich Plasma in Intra-Articular Knee Injections for Osteoarthritis: A Systematic Review.

PubMed

Lai, Lawrence P; Stitik, Todd P; Foye, Patrick M; Georgy, John S; Patibanda, Varun; Chen, Boqing

2015-06-01

To systematically analyze the literature on the use of platelet-rich plasma (PRP) for intra-articular injections of the knee and its efficacy in the treatment of knee osteoarthritis (OA). Systematic literature reviews were conducted in PubMed, Embase, and CINAHL (ie, Cumulative Index to Nursing and Allied Health Literature) on October 30, 2013, using the keywords "platelet-rich plasma" and "knee" and "osteoarthritis." Inclusion criteria included (1) studies with human subjects, (2) prospective clinical studies (including either clinical trials or observational studies), and (3) full-text articles published in English. Exclusion criteria were: (1) animal studies; (2) retrospective studies; (3) patients with previous surgical intervention with total knee arthroplasty or reconstruction of the anterior cruciate ligaments; and (4) articles not published in English A total of 319 abstracts and titles were reviewed (60 from PubMed, 250 from Embase, and 9 from CINAHL). A total of 8 relevant journal articles were identified, all of which were published between 2010 and 2013. One-half of the studies were prospective observational studies that included only PRP treatment; the rest were prospective comparative studies including both PRP and controls-2 were randomized controlled trials. Of the 4 comparative studies, 3 compared PRP with hyaluronic acid, which was considered as a commonly used effective treatment for knee OA; the other one used saline injection (ie, placebo) as the control. Although most of the analyses suffered from small sample size and was thus inconclusive, the findings consistently indicated that PRP might have better outcomes in patients with a lesser degree of degeneration and in younger patients. PRP intra-articular injections of the knee may be an effective alternative treatment for knee OA. However, current studies are at best inconclusive regarding the efficacy of the PRP treatment. A large, multicenter randomized trial study is needed to further assess the efficacy of PRP treatment for patients with knee OA. Copyright © 2015 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Comparison of the effects of platelet-rich or growth factor-rich plasma on intestinal anastomosis healing in pigs.

PubMed

Giusto, Gessica; Vercelli, Cristina; Iussich, Selina; Tursi, Massimiliano; Perona, Giovanni; Gandini, Marco

2017-06-19

The use of autologous platelet-rich plasma (PRP) and plasma rich in growth factors (PRGF) has been proposed for the treatment of several acute and chronic syndromes, such as corneal epithelial defects and dry eye syndrome, gum bleeding during oral surgery, and in orthopaedic surgery. We hypothesized that PRGF, rather than PRP, could be more effective because of its intrinsic characteristics in promoting the healing of intestinal anastomosis. The purpose of the present study was to evaluate and compare the effects of PRP and PRGF on various parameters of anastomotic healing in a swine model. Eight female pigs were randomly assigned to two groups and subjected to hand sewn jeujuno-jejunal appositional extramucosal anastomoses. For each animal, a total of six anastomoses were performed: two were considered controls and received no treatment, while the remaining four anastomoses were treated with PRP or PRGF of which both were prepared at a platelet concentration that was respectively 3.4-fold and 2.81-fold higher than the original platelet count. In each animal, either PRP or PRGF was used as a treatment, to avoid interference among products. Animals were euthanized after 8 days and the anastomoses were evaluated and compared for the presence of adhesions, anastomotic leakage, bursting pressure, and histological appearance. The concentration of platelets in PRP was 3.41-fold higher (range, 3.20-4.24) that the concentration in whole blood, while the concentration in PRGF was 2.81-fold higher (range, 2.89-4.88). The results obtained from the present study highlighted that there are no differences between anastomotic samples treated with either PRP or PRGF preparations, except for a significant increase in epithelization of the intestinal mucosa at the anastomotic site in the PRGF group. Both PRP and PRGF suspensions should be considered a safe strategy and represent a relatively low-cost technology that is flexible enough to be applied in several therapeutic fields. No true benefit could be proven in our study compared to the no treatment following anastomoses formation, with the exception of enhanced epithelization of the mucosa in the PRGF group.

Platelet-rich plasma preparation for regenerative medicine: optimization and quantification of cytokines and growth factors.

PubMed

Amable, Paola Romina; Carias, Rosana Bizon Vieira; Teixeira, Marcus Vinicius Telles; da Cruz Pacheco, Italo; Corrêa do Amaral, Ronaldo José Farias; Granjeiro, José Mauro; Borojevic, Radovan

2013-06-07

Platelet-rich plasma (PRP) is nowadays widely applied in different clinical scenarios, such as orthopedics, ophthalmology and healing therapies, as a growth factor pool for improving tissue regeneration. Studies into its clinical efficiency are not conclusive and one of the main reasons for this is that different PRP preparations are used, eliciting different responses that cannot be compared. Platelet quantification and the growth factor content definition must be defined in order to understand molecular mechanisms behind PRP regenerative strength. Standardization of PRP preparations is thus urgently needed. PRP was prepared by centrifugation varying the relative centrifugal force, temperature, and time. Having quantified platelet recovery and yield, the two-step procedure that rendered the highest output was chosen and further analyzed. Cytokine content was determined in different fractions obtained throughout the whole centrifugation procedure. Our method showed reproducibility when applied to different blood donors. We recovered 46.9 to 69.5% of total initial platelets and the procedure resulted in a 5.4-fold to 7.3-fold increase in platelet concentration (1.4 × 10(6) to 1.9 × 10(6) platelets/μl). Platelets were highly purified, because only <0.3% from the initial red blood cells and leukocytes was present in the final PRP preparation. We also quantified growth factors, cytokines and chemokines secreted by the concentrated platelets after activation with calcium and calcium/thrombin. High concentrations of platelet-derived growth factor, endothelial growth factor and transforming growth factor (TGF) were secreted, together with the anti-inflammatory and proinflammatory cytokines interleukin (IL)-4, IL-8, IL-13, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-α. No cytokines were secreted before platelet activation. TGF-β3 and IFNγ were not detected in any studied fraction. Clots obtained after platelet coagulation retained a high concentration of several growth factors, including platelet-derived growth factor and TGF. Our study resulted in a consistent PRP preparation method that yielded a cytokine and growth factor pool from different donors with high reproducibility. These findings support the use of PRP in therapies aiming for tissue regeneration, and its content characterization will allow us to understand and improve the clinical outcomes.

Platelet-rich plasma to treat experimentally-induced skin wounds in animals: A systematic review and meta-analysis

PubMed Central

Attili, Anna Rita; Dupré, Gilles; Cantalamessa, Andrea; Martin, Stefano; Cuteri, Vincenzo; Marcazzan, Sabrina; Del Fabbro, Massimo

2018-01-01

The objective of the study was to review current literature to determine whether the topical application of platelet-rich plasma (PRP) promotes healing in experimentally-induced full-thickness skin wounds in animals. The hypothesis was that the adjunct of PRP has a positive effect on wound healing. An electronic search was carried out on the following databases: Web of Science, Cochrane Library, PubMed, Research Gate, Cochrane Wounds Group, Veterinary Information Network. No publication date nor language restrictions were applied. Randomised and not randomised controlled clinical trials comparing PRP with placebo or with other treatments were included. The reduction of open wound area in PRP-treated (test) wounds compared to control wounds was the primary outcome. Secondary outcomes were healing time and number of healed cases in test group compared to control. The following effect sizes were calculated: the Hedges’ g for continuous variables; the odds ratio for binary data. Eighteen controlled clinical trials were included in the qualitative and quantitative synthesis, with a total of 661 wounds. All studies were published in the period 2007–2016. Eight studies were carried out on rodent/lagomorph mammals and 10 on non-rodent/lagomorph mammals. In all included studies, control wounds underwent placebo or were left untreated. The PRP group showed a better healing performance than the control group in each outcome. The effect size was statistically significant considering the primary outcome and the overall aggregation of the three outcomes. The effect size, although in favour of the treatment with PRP, was not significant considering the healing time and the number of healings. The overall heterogeneity was mild or moderate. Five studies reported a high risk of selection bias. The publication bias was always mild or absent. The results support the hypothesis of the positive effects of the PRP when compared to control groups in the treatment of experimentally-induced full-thickness skin wounds in animals. PRP can therefore be considered an effective adjunctive therapy in stimulating second intention healing of acute wounds in healthy animals. PMID:29324848

Effect of Intraoperative Platelet-Rich Plasma Treatment on Postoperative Donor Site Knee Pain in Patellar Tendon Autograft Anterior Cruciate Ligament Reconstruction: A Double-Blind Randomized Controlled Trial.

PubMed

Walters, Brian L; Porter, David A; Hobart, Sarah J; Bedford, Benjamin B; Hogan, Daniel E; McHugh, Malachy M; Klein, Devon A; Harousseau, Kendall; Nicholas, Stephen J

2018-05-01

Donor site morbidity in the form of anterior knee pain is a frequent complication after bone-patellar tendon-bone (BPTB) autograft anterior cruciate ligament (ACL) reconstruction. Hypothesis/Purpose: The purpose was to examine the effect of the intraoperative administration of platelet-rich plasma (PRP) on postoperative kneeling pain. It was hypothesized that PRP treatment would reduce knee pain. Randomized controlled trial; Level of evidence, 2. Fifty patients (mean ± SD age, 30 ± 12 years) undergoing BPTB ACL autograft reconstruction were randomized to the PRP (n = 27) or sham (n = 23) treatment. In either case, 10 mL of venous blood was drawn before the induction of anesthesia and either discarded (sham) or processed (PRP) for preparation of a PRP gel to be later mixed with donor site bone chips and inserted into the patellar defect. At 12 weeks, 6 months, 1 year, and 2 years after surgery, patients completed International Knee Documentation Committee (IKDC) forms and visual analog scale pain scores for activities of daily living and kneeling. Healing indices at the donor site were assessed by routine noncontrast magnetic resonance imaging (MRI) at 6 months. Mixed-model analysis of variance was used to assess the effect of PRP on patient symptoms and MRI indices of donor site healing, as measured by the width of the donor site defect. Kneeling pain, pain with activities of daily living, and IKDC scores were not different between treatment groups at any of the time intervals ( P = .08-.83). Kneeling pain improved from 12 weeks to 6 months and from 1 to 2 years ( P < .05). IKDC scores improved substantially from 12 weeks to 6 months ( P < .001) and continued to improve to 2 years (PRP, 86 ± 19; sham, 89 ± 10). MRI indices of donor site healing were not different between treatment groups ( P = .53-.90). Whether randomized to receive PRP in their patellar defect or not, patients continued to have similar levels of kneeling pain and patellar defect sizes after autograft BPTB ACL reconstruction. Registration: NCT01765712 ( ClinicalTrials.gov identifier).

Novel nuclear magnetic resonance techniques for studying biological molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laws, David Douglas

2000-06-01

Over the fifty-five year history of Nuclear Magnetic Resonance (NMR), considerable progress has been made in the development of techniques for studying the structure, function, and dynamics of biological molecules. The majority of this research has involved the development of multi-dimensional NMR experiments for studying molecules in solution, although in recent years a number of groups have begun to explore NMR methods for studying biological systems in the solid-state. Despite this new effort, a need still exists for the development of techniques that improve sensitivity, maximize information, and take advantage of all the NMR interactions available in biological molecules. Inmore » this dissertation, a variety of novel NMR techniques for studying biomolecules are discussed. A method for determining backbone (Φ/Ψ) dihedral angles by comparing experimentally determined 13C a, chemical-shift anisotropies with theoretical calculations is presented, along with a brief description of the theory behind chemical-shift computation in proteins and peptides. The utility of the Spin-Polarization Induced Nuclear Overhauser Effect (SPINOE) to selectively enhance NMR signals in solution is examined in a variety of systems, as are methods for extracting structural information from cross-relaxation rates that can be measured in SPINOE experiments. Techniques for the production of supercritical and liquid laser-polarized xenon are discussed, as well as the prospects for using optically pumped xenon as a polarizing solvent. In addition, a detailed study of the structure of PrP 89-143 is presented. PrP 89-143 is a 54 residue fragment of the prion proteins which, upon mutation and aggregation, can induce prion diseases in transgenic mice. Whereas the structure of the wild-type PrP 89-143 is a generally unstructured mixture of α-helical and β-sheet conformers in the solid state, the aggregates formed from the PrP 89-143 mutants appear to be mostly β-sheet.« less

Prion Propagation in Cells Expressing PrP Glycosylation Mutants ▿

PubMed Central

Salamat, Muhammad K.; Dron, Michel; Chapuis, Jérôme; Langevin, Christelle; Laude, Hubert

2011-01-01

Infection by prions involves conversion of a host-encoded cell surface protein (PrPC) to a disease-related isoform (PrPSc). PrPC carries two glycosylation sites variably occupied by complex N-glycans, which have been suggested by previous studies to influence the susceptibility to these diseases and to determine characteristics of prion strains. We used the Rov cell system, which is susceptible to sheep prions, to generate a series of PrPC glycosylation mutants with mutations at one or both attachment sites. We examined their subcellular trafficking and ability to convert into PrPSc and to sustain stable prion propagation in the absence of wild-type PrP. The susceptibility to infection of mutants monoglycosylated at either site differed dramatically depending on the amino acid substitution. Aglycosylated double mutants showed overaccumulation in the Golgi compartment and failed to be infected. Introduction of an ectopic glycosylation site near the N terminus fully restored cell surface expression of PrP but not convertibility into PrPSc, while PrPC with three glycosylation sites conferred cell permissiveness to infection similarly to the wild type. In contrast, predominantly aglycosylated molecules with nonmutated N-glycosylation sequons, produced in cells expressing glycosylphosphatidylinositol-anchorless PrPC, were able to form infectious PrPSc. Together our findings suggest that glycosylation is important for efficient trafficking of anchored PrP to the cell surface and sustained prion propagation. However, properly trafficked glycosylation mutants were not necessarily prone to conversion, thus making it difficult in such studies to discern whether the amino acid changes or glycan chain removal most influences the permissiveness to prion infection. PMID:21248032

Comparing different preparation methods to study human fibrin fibers and platelets using TEM.

PubMed

Buys, Antoinette V; Pretorius, Etheresia

2012-06-01

For the study of cellular ultrastructure, the sample needs to be stabilized by fixation, with the ultimate aim to preserve the native tissue organization and to protect the tissue against later stages of preparation. Chemical and freezing fixation are most used, and chemical fixation employs agents that permeate tissues and cells by diffusion and covalently bind with their major biochemical constituents to fix them. Most widely used chemical fixatives are aldehydes, e.g., formaldehyde and glutaraldehyde, which are noncoagulating, crosslinking agents. Cryofixation methods for ultrastructural studies are also popular, and high-pressure freezing immobilizes all cell constituents and arrests biological activity by removing the thermal energy from the system. In the current research, we used platelet-rich plasma (PRP) to study expansive fibrin fibers and platelet ultrastructure to compare the two fixation techniques. We also used thrombin and calcium chloride as a clotting agent to determine the technique most suitable for the formation of extensive fibrin networks. Chemically fixated fibrin fibers were more compact and condensed and also showed a banding pattern on longitudinal sections. High-pressure frozen samples were more dispersed while platelets fixated showed better preserved cellular membranes and organelle structure. PRP coagulated by addition of CaCl(2) showed blood platelets that are noticeably more activated compared with PRP; however, with thrombin, a sharp ultrastructure was seen. We conclude that PRP mixed with thrombin, and freeze substituted, is the most suitable method for the study of extensive fibrin fibers as well as platelets. Copyright © 2011 Wiley Periodicals, Inc.

Clinical Results of Platelet-Rich Plasma for Partial Thickness Rotator Cuff Tears: A Case Series.

PubMed

Zafarani, Zohreh; Mirzaee, Fateme; Guity, Mohamadreza; Aslani, Hamidreza

2017-09-01

Partial thickness rotator cuff tears (PTRCTs) are a common pathology among shoulder disorders in people over 50 years. Treatment of PTRCTs remains controversial. Most studies on the treatment of PTRCTs have explained surgical techniques or outcomes; few studies have centralized on the conservative and new management of PTRCTs, like treatment with Platelet-rich plasma (PRP). These case series study have been conducted on Platelet-rich plasma (PRP) injection, as a concentrated source of cytokines that can stimulate healing of soft tissue. PRP injection showed positive effect on improving PTRCTs complains. This method improved pain, function, DASH score and shoulder joint range motion in. Because of PRP products are safe and easy to prepare and apply, and also according to improving patient's condition, this method can be used to treat PTRCTs.

Platelet gel: a new therapeutic tool with great potential

PubMed Central

Piccin, Andrea; Di Pierro, Angela M.; Canzian, Lucia; Primerano, Marco; Corvetta, Daisy; Negri, Giovanni; Mazzoleni, Guido; Gastl, Günther; Steurer, Michael; Gentilini, Ivo; Eisendle, Klaus; Fontanella, Fabrizio

2017-01-01

Chronic wounds, such as diabetic foot ulcers, represent a serious clinical problem for patients and clinicians. Management of these wounds has a strong economic impact worldwide. Complications resulting from injuries are a frequent cause of morbidity and mortality. Chronic wounds lead to infections, painful dressings and prolonged hospitalisation. This results in poor patient Quality of Life and in high healthcare costs. Platelet concentrates (PC) are defined as autologous or allogeneic platelet derivatives with a platelet concentration higher than baseline. PC are widely used in different areas of Regenerative Medicine in order to enhance wound healing processes; they include platelet-rich plasma (PRP), platelet gel (PG), platelet-rich fibrin (PRF), serum eye drops (E-S), and PRP eye drops (E-PRP). This review highlights the use of platelet-rich plasma (PRP) and platelet gel (PG) preparation for clinical use. PMID:27483482

Ocular pulse amplitude after panretinal photocoagulation in normotensive eyes with proliferative diabetic retinopathy.

PubMed

Bozic, Marija M; Karadzic, Jelena B; Kovacevic, Igor M; Marjanovic, Ivan S

2017-06-26

To assess the effect of panretinal laser photocoagulation on ocular pulse amplitude (OPA) in normotensive eyes with proliferative diabetic retinopathy. Prospectively, we performed unilateral argon laser panretinal photocoagulation (PRP) in 30 patients with diabetes mellitus type II and previously untreated bilateral proliferative diabetic retinopathy. Before and 7 and 30 days after the treatment, OPA was measured using dynamic contour tonometer. Compared with the untreated contralateral eyes, laser photocoagulation led to a reduction of OPA. Ocular pulse amplitude did not significantly differ in photocoagulated eyes 7 days after the treatment, but there was a significant difference in OPA 30 days after the treatment. The decrease in OPA values was 15% 7 days after PRP and 40% 30 days after PRP. Ocular pulse amplitude reduction after PRP indirectly informs us about choriocapillary closure, already reported in previous studies.

Functional and conformational properties of phaseolin (Phaseolus vulgris L.) and kidney bean protein isolate: a comparative study.

PubMed

Yin, Shou-Wei; Tang, Chuan-He; Wen, Qi-Biao; Yang, Xiao-Quan

2010-03-15

Kidney bean (Phaseolus vulgris L.) seed is an underutilised plant protein source with good potential to be applied in the food industry. Phaseolin (also named G1 globulin) represents about 50 g kg(-1) of total storage protein in the seed. The aim of the present study was to characterise physicochemical, functional and conformational properties of phaseolin, and to compare these properties with those of kidney bean protein isolate (KPI). Compared with kidney bean protein isolate (KPI), the acid-extracted phaseolin-rich protein product (PRP) had much lower protein recovery of 320 g kg(-1) (dry weight basis) but higher phaseolin purity (over 950 g kg(-1)). PRP contained much lower sulfhydryl (SH) and disulfide bond contents than KPI. Differential scanning calorimetry analyses showed that the phaseolin in PRP was less denatured than in KPI. Thermal analyses in the presence or absence of dithiothreitol, in combination with SH and SS content analyses showed the contributions of SS to the thermal stability of KPI. The analyses of near-UV circular dichroism and intrinsic fluorescence spectra indicated more compacted tertiary conformation of the proteins in PRP than in KPI. PRP exhibited much better protein solubility, emulsifying activity index, and gel-forming ability than KPI. The relatively poor functional properties of KPI may be associated with protein denaturation/unfolding, with subsequent protein aggregation. The results presented here suggest the potential for acid-extracted PRP to be applied in food formulations, in view of its functional properties.

Development of a Porcine Delayed Wound-Healing Model and Its Use in Testing a Novel Cell-Based Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hadad, Ivan, E-mail: ihadad@iupui.ed; Johnstone, Brian H.; Brabham, Jeffrey G.

2010-11-01

Purpose: A delayed full-thickness wound-healing model was developed and used for examining the capacity of adipose-derived stem cells (ASCs), either alone or in platelet-rich fibrin gels, to promote healing. Methods and Materials: Four pigs received electron beam radiation to the dorsal skin surface. Five weeks after radiation, subcutaneous fat was harvested from nonirradiated areas and processed to yield ASCs. Two weeks later, 28 to 30 full-thickness 1.5-cm{sup 2} wounds were made in irradiated and nonirradiated skin. Wounds were treated with either saline solution, ASCs in saline solution, platelet-rich plasma (PRP) fibrin gel, ASCs in PRP, or non-autologous green fluorescence protein-labeledmore » ASCs. Results: The single radiation dose produced a significant loss of dermal microvasculature density (75%) by 7 weeks. There was a significant difference in the rate of healing between irradiated and nonirradiated skin treated with saline solution. The ASCs in PRP-treated wounds exhibited a significant 11.2% improvement in wound healing compared with saline solution. Enhancement was dependent on the combination of ASCs and PRP, because neither ASCs nor PRP alone had an effect. Conclusions: We have created a model that simulates the clinically relevant late radiation effects of delayed wound healing. Using this model, we showed that a combination of ASCs and PRP improves the healing rates of perfusion-depleted tissues, possibly through enhancing local levels of growth factors.« less

Intracellular accumulation of a mild-denatured monomer of the human PrP fragment 90-231, as possible mechanism of its neurotoxic effects.

PubMed

Chiovitti, Katia; Corsaro, Alessandro; Thellung, Stefano; Villa, Valentina; Paludi, Domenico; D'Arrigo, Cristina; Russo, Claudio; Perico, Angelo; Ianieri, Adriana; Di Cola, Domenico; Vergara, Alberto; Aceto, Antonio; Florio, Tullio

2007-12-01

Because of high tendency of the prion protein (PrP) to aggregate, the exact PrP isoform responsible for prion diseases as well as the pathological mechanism that it activates remains still controversial. In this study, we show that a pre-fibrillar, monomeric or small oligomeric conformation of the human PrP fragment 90-231 (hPrP90-231), rather than soluble or fibrillar large aggregates, represents the neurotoxic species. In particular, we demonstrate that monomeric mild-denatured hPrP90-231 (incubated for 1 h at 53 degrees C) induces SH-SY5Y neuroblastoma cell death, while, when structured in large aggregates, it is ineffective. Using spectroscopic and cellular techniques we demonstrate that this toxic conformer is characterized by a high exposure of hydrophobic regions that favors the intracellular accumulation of the protein. Inside the cells hPrP90-231 is mainly compartmentalized into the lysosomes where it may trigger pro-apoptotic 'cell death' signals. The PrP toxic conformation, which we have obtained inducing a controlled in vitro conformational change of the protein, might mimic mild-unfolding events occurring in vivo, in the presence of specific mutations, oxidative reactions or proteolysis. Thus, in light of this model, we propose that novel therapeutic strategies, designed to inhibit the interaction of the toxic PrP with the plasmamembrane, could be beneficial to prevent the formation of intracellular neurotoxic aggregates and ultimately the neuronal death.

Comparative Analysis of Cellular and Growth Factor Composition in Bone Marrow Aspirate Concentrate and Platelet-Rich Plasma.

PubMed

Sugaya, Hisashi; Yoshioka, Tomokazu; Kato, Toshiki; Taniguchi, Yu; Kumagai, Hiroshi; Hyodo, Kojiro; Ohneda, Osamu; Yamazaki, Masashi; Mishima, Hajime

2018-01-01

The purpose of this study was to quantify the stem cell and growth factor (GF) contents in the bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP) prepared from whole blood using a protocol established in our laboratory. We examined 10 patients with osteonecrosis of the femoral head who were treated by autologous BMAC transplantation at our hospital between January 2015 and June 2015. We quantified CD34+ and CD31-CD45-CD90+CD105+ cells in BMAC and PRP by flow cytometry. Additionally, we measured various GFs, that is, basic fibroblast growth factor (b-FGF), platelet-derived growth factor-BB (PDGF-BB), vascular endothelial growth factor (VEGF), transforming growth factor- β 1 (TGF- β 1), and bone morphogenetic protein-2 (BMP-2) in BMAC and PRP using enzyme-linked immunosorbent assays and statistical analyses. CD34+ and CD31-45-90+105+ cells accounted for approximately 1.9% and 0.03% of cells in BMAC and no cells in PRP. The concentration of b-FGF was higher in BMAC than in PRP ( P < 0.001), whereas no significant differences in the levels of PDGF-BB, VEGF, TGF- β 1, and BMP-2 were observed between the two types of sample. BMAC had an average of 1.9% CD34+ and 0.03% CD31-45-90+105+ cells and higher levels of b-FGF than those of PRP.

A ZIP6-ZIP10 heteromer controls NCAM1 phosphorylation and integration into focal adhesion complexes during epithelial-to-mesenchymal transition.

PubMed

Brethour, Dylan; Mehrabian, Mohadeseh; Williams, Declan; Wang, Xinzhu; Ghodrati, Farinaz; Ehsani, Sepehr; Rubie, Elizabeth A; Woodgett, James R; Sevalle, Jean; Xi, Zhengrui; Rogaeva, Ekaterina; Schmitt-Ulms, Gerold

2017-01-18

The prion protein (PrP) evolved from the subbranch of ZIP metal ion transporters comprising ZIPs 5, 6 and 10, raising the prospect that the study of these ZIPs may reveal insights relevant for understanding the function of PrP. Building on data which suggested PrP and ZIP6 are critical during epithelial-to-mesenchymal transition (EMT), we investigated ZIP6 in an EMT paradigm using ZIP6 knockout cells, mass spectrometry and bioinformatic methods. Reminiscent of PrP, ZIP6 levels are five-fold upregulated during EMT and the protein forms a complex with NCAM1. ZIP6 also interacts with ZIP10 and the two ZIP transporters exhibit interdependency during their expression. ZIP6 contributes to the integration of NCAM1 in focal adhesion complexes but, unlike cells lacking PrP, ZIP6 deficiency does not abolish polysialylation of NCAM1. Instead, ZIP6 mediates phosphorylation of NCAM1 on a cluster of cytosolic acceptor sites. Substrate consensus motif features and in vitro phosphorylation data point toward GSK3 as the kinase responsible, and interface mapping experiments identified histidine-rich cytoplasmic loops within the ZIP6/ZIP10 heteromer as a novel scaffold for GSK3 binding. Our data suggests that PrP and ZIP6 inherited the ability to interact with NCAM1 from their common ZIP ancestors but have since diverged to control distinct posttranslational modifications of NCAM1.

Preparation of a new composite combining strengthened β-tricalcium phosphate with platelet-rich plasma as a potential scaffold for the repair of bone defects

PubMed Central

WANG, CHENGGONG; ZHONG, DA; ZHOU, XING; YIN, KE; LIAO, QIANDE; KONG, LINGYU; LIU, ANSONG

2014-01-01

β-tricalcium phosphate (β-TCP) and platelet-rich plasma (PRP) are commonly used in bone tissue engineering. In the present study, a new composite combining strengthened β-TCP and PRP was prepared and its morphological and mechanical properties were investigated by scanning electron microscopy (SEM) and material testing. The biocompatibility was evaluated by measuring the adhesion rate and cytotoxicity of bone marrow stromal cells (BMSCs). The strengthened β-TCP/PRP composite had an appearance like the fungus Boletus kermesinus with the PRP gel distributed on the surface of the micropores. The maximum load and load intensity were 945.6±86.4 N and 13.1±0.5 MPa, which were significantly higher than those of β-TCP (110.1±14.3 N and 1.6±0.2 MPa; P<0.05). The BMSC adhesion rate on the strengthened β-TCP/PRP composite was >96% after 24 h, with a cell cytotoxicity value of zero. SEM micrographs revealed that following seeding of BMSCs onto the composite in high-glucose Dulbecco’s modified Eagle’s medium culture for two weeks, the cells grew well and exhibited fusiform, spherical and polygonal morphologies, as well as pseudopodial connections. The strengthened β-TCP/PRP composite has the potential to be used as a scaffold in bone tissue engineering due to its effective biocompatibility and mechanical properties. PMID:25187800

Platelet-rich plasma, plasma rich in growth factors and simvastatin in the regeneration and repair of alveolar bone.

PubMed

Rivera, César; Monsalve, Francisco; Salas, Juan; Morán, Andrea; Suazo, Iván

2013-12-01

Platelet preparations promote bone regeneration by inducing cell migration, proliferation and differentiation in the area of the injury, which are essential processes for regeneration. In addition, several studies have indicated that simvastatin (SIMV), widely used for the treatment of hypercholesterolemia, stimulates osteogenesis. The objective of this study was to evaluate the effects of treatment with either platelet-rich plasma (PRP) or plasma rich in growth factors (PRGF) in combination with SIMV in the regeneration and repair of alveolar bone. The jaws of Sprague Dawley rats (n=18) were subjected to rotary instrument-induced bone damage (BD). Animals were divided into six groups: BD/H 2 O (n=3), distilled water without the drug and alveolar bone damage; BD/H 2 O/PRP (n=3), BD and PRP; BD/H 2 O/PRGF (n=3), BD and PRGF; BD/SIMV (n=3), BD and water with SIMV; BD/SIMV/PRP (n=3), BD, PRP and SIMV; and BD/SIMV/PRGF (n=3), BD, PRGF and SIMV. Conventional histological analysis (hematoxylin and eosin staining) revealed that the BD/SIMV group showed indicators for mature bone tissue, while the BD/SIMV/PRP and BD/SIMV/PRGF groups showed the coexistence of indicators for mature and immature bone tissue, with no statistical differences between the platelet preparations. Simvastatin did not improve the effect of platelet-rich plasma and plasma rich in growth factors. It was not possible to determine which platelet preparation produced superior effects.

Platelet-rich plasma, plasma rich in growth factors and simvastatin in the regeneration and repair of alveolar bone

PubMed Central

RIVERA, CÉSAR; MONSALVE, FRANCISCO; SALAS, JUAN; MORÁN, ANDREA; SUAZO, IVÁN

2013-01-01

Platelet preparations promote bone regeneration by inducing cell migration, proliferation and differentiation in the area of the injury, which are essential processes for regeneration. In addition, several studies have indicated that simvastatin (SIMV), widely used for the treatment of hypercholesterolemia, stimulates osteogenesis. The objective of this study was to evaluate the effects of treatment with either platelet-rich plasma (PRP) or plasma rich in growth factors (PRGF) in combination with SIMV in the regeneration and repair of alveolar bone. The jaws of Sprague Dawley rats (n=18) were subjected to rotary instrument-induced bone damage (BD). Animals were divided into six groups: BD/H2O (n=3), distilled water without the drug and alveolar bone damage; BD/H2O/PRP (n=3), BD and PRP; BD/H2O/PRGF (n=3), BD and PRGF; BD/SIMV (n=3), BD and water with SIMV; BD/SIMV/PRP (n=3), BD, PRP and SIMV; and BD/SIMV/PRGF (n=3), BD, PRGF and SIMV. Conventional histological analysis (hematoxylin and eosin staining) revealed that the BD/SIMV group showed indicators for mature bone tissue, while the BD/SIMV/PRP and BD/SIMV/PRGF groups showed the coexistence of indicators for mature and immature bone tissue, with no statistical differences between the platelet preparations. Simvastatin did not improve the effect of platelet-rich plasma and plasma rich in growth factors. It was not possible to determine which platelet preparation produced superior effects. PMID:24250728

Systematic review of the efficacy of fat grafting and platelet-rich plasma for wound healing.

PubMed

Smith, Oliver J; Kanapathy, Muholan; Khajuria, Ankur; Prokopenko, Max; Hachach-Haram, Nadine; Mann, Haroon; Mosahebi, Ash

2018-05-09

Adipose-derived stem cells found in fat grafts may have significant healing properties. When fat is combined with autologous platelet-rich plasma (PRP), there may be enhanced healing effects due to the pro-angiogenic and anti-inflammatory effects of PRP. This study aimed to evaluate the current evidence on fat grafting in combination with PRP for wound healing to establish the efficacy of this technique. A comprehensive search in the MEDLINE, EMBASE, CENTRAL, Science Citation Index, and Google Scholar databases (to March 2017) was conducted to identify studies on fat grafting and PRP for wound healing. Case series of less than 3 cases and studies only describing harvest technique were excluded. The database identified 571 articles, of which 3 articles that used a combination of fat and PRP for wound healing (1 RCT and 2 case series) were included in this review. A total of 69 wounds in 64 patients were treated with an average wound size of 36.32cm 2 . Of these, 67% of wounds achieved complete healing. When reported, the mean time to healing was 7.5 weeks for those who underwent a single treatment. There were no significant complications in any patients. The combination of fat grafting and PRP may achieve adequate wound healing with relatively quick wound healing time compared with standard wound management options. However, evidence is extremely limited, and further studies are required to evaluate its efficacy for wound healing. © 2018 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

The Effects of Platelet-Rich Plasma on Bone Marrow Stromal Cell Transplants for Tendon Healing In Vitro

PubMed Central

Morizaki, Yutaka; Zhao, Chunfeng; An, Kai-Nan; Amadio, Peter C.

2010-01-01

Purpose In this study we investigated the effect of platelet-rich plasma (PRP) and bone-marrow derived stromal cell (BMSC)-seeded interposition in an in vitro canine tendon repair model. Methods Bone marrow, peripheral blood, and tendons were harvested from mixed breed dogs. BMSC were cultured and passaged from adherent cells of bone marrow suspension. PRP was purified from peripheral blood using a commercial kit. 192 flexor digitorum profundus tendons were used for the study. Tendons repaired with a simple suture were used as a control group. In treatment groups, a collagen gel patch was interposed at the tendon repair site prior to suture. There were three treatment groups according to the type of collagen patch; a patch with PRP, a patch with BMSC, and a patch with PRP and BMSC. The repaired tendons were evaluated by biomechanical testing and by histological survey after 2 and 4 weeks in tissue culture. To evaluate viability, cells were labeled with PKH26 and surveyed under confocal microscopy after culture. Results The maximum breaking strength and stiffness of the healing tendons with the BMSC-seeded PRP patch was significantly higher than the healing tendons without a patch or with a cell-seeded patch (p<0.02). Viable BMSC were present at both 2 and 4 weeks. Conclusions PRP enhanced the effect of BMSC-seeded collagen gel interposition in this in vitro model. Based on these results we now plan to investigate this effect in vivo. PMID:20951509

Forced swimming test and fluoxetine treatment: in vivo evidence that peripheral 5-HT in rat platelet-rich plasma mirrors cerebral extracellular 5-HT levels, whilst 5-HT in isolated platelets mirrors neuronal 5-HT changes.

PubMed

Bianchi, M; Moser, C; Lazzarini, C; Vecchiato, E; Crespi, F

2002-03-01

Low levels of central serotonin (5-HT) have been related to the state of depression, and 5-HT is the major target of the newer antidepressant drugs such as selective serotonin reuptake inhibitors (SSRIs). Neurons and platelets display structural and functional similarities, so that the latter have been proposed as a peripheral model of central functions. In particular, in blood more than 99% of 5-HT is contained in platelets, so that one could consider changes in 5-HT levels in platelets as a mirror of changes in central 5-HT. Here, this hypothesis has been studied via the analysis of the influence of: (1) the forced swimming test (FST, which has been proved to be of utility to predict the clinical efficacy of antidepressants in rodents) and (2) treatment with the SSRI fluoxetine upon 5-HT levels monitored in brain regions and in peripheral platelets by means of electrochemical in vivo and ex vivo measurements. The results obtained confirm that the FST increases immobility; furthermore they show a parallel and significant decrease in cerebral (brain homogenate) and peripheral (in platelet-rich plasma, PRP) voltammetric 5-HT levels following the FST in naive rats. In addition, subchronic treatment with fluoxetine was followed by a significant increase in 5-HT levels in PRP, while the same SSRI treatment performed within the FST resulted in a decrease in the 5-HT levels in PRP. However, this decrease was inferior to that observed without SSRI treatment. These data suggest that there is an inverse relationship between immobility and the levels of 5-HT in PRP and that these peripheral 5-HT levels are sensitive to: (1) the FST, (2) the treatment with fluoxetine and (3) the combination of both treatments, i.e. SSRI + FST. It has been reported that SSRI treatment at first inhibits the 5-HT transporter in brain, resulting in increased extracellular 5-HT, while following sustained SSRI treatments decreased intracellular levels of central 5-HT were observed. Accordingly, the present data show that the initial block of 5-HT reuptake is revealed by the selective increase in 5-HT levels (extracellular content) measured in PRP (not in insulated platelets, IPs) the 1st day of fluoxetine treatment. The initial action of this SSRI upon the 5-HT transporter in brain has also been confirmed by in vivo voltammetric data showing selective increase in the serotonergic signal following local injection of fluoxetine into the brain region studied. Successively, the major effect monitored is a decrease in 5-HT levels, which is more evident in IPs than in PRP. However, it is known that following 2 weeks treatment with an SSRI, 5-HT autoreceptors are desensitized and the serotonin synthesis is restored, together with the intracellular 5-HT levels. The present data showing that the levels of 5-HT in IPs tend to return to control values 12 days after the beginning of chronic fluoxetine treatment suggest that 5-HT levels in IPs (intracellular environment) mirror the influence of SSRI treatment upon the central 5-HT system. On the other hand, at day 12 of the chronic fluoxetine treatment, 5-HT content remains low in PRP. Similarly, low levels of 5-HT have been monitored in brain homogenate of rats chronically treated with fluoxetine. This would support the similarity between PRP preparation and brain homogenate as in both cases cells are disrupted by sample preparation. In conclusion this work supports the literature in proposing platelets as a peripheral model of central functions. In particular, the present data support the idea that peripheral 5-HT platelet levels can reflect the state of the central 5-HT system in conditions of depression. Furthermore, the main outcome of this study is that PRP may mirror central extracellular 5-HT levels, whilst IPs mirror neuronal 5-HT changes.

Platelet-rich-plasmapheresis for minimising peri-operative allogeneic blood transfusion.

PubMed

Carless, Paul A; Rubens, Fraser D; Anthony, Danielle M; O'Connell, Dianne; Henry, David A

2011-03-16

Concerns regarding the safety of transfused blood have generated considerable enthusiasm for the use of technologies intended to reduce the use of allogeneic blood (blood from an unrelated donor). Platelet-rich plasmapheresis (PRP) offers an alternative approach to blood conservation. To examine the evidence for the efficacy of PRP in reducing peri-operative allogeneic red blood cell (RBC) transfusion, and the evidence for any effect on clinical outcomes such as mortality and re-operation rates. We identified studies by searching MEDLINE (1950 to 2009), EMBASE (1980 to 2009), The Cochrane Library (Issue 1, 2009), the Internet (to March 2009) and the reference lists of published articles, reports, and reviews. Controlled parallel group trials in which adult patients, scheduled for non-urgent surgery, were randomised to PRP, or to a control group which did not receive the intervention. Primary outcomes measured were: the number of patients exposed to allogeneic RBC transfusion, and the amount of RBC transfused. Other outcomes measured were: the number of patients exposed to allogeneic platelet transfusions, fresh frozen plasma, and cryoprecipitate, blood loss, re-operation for bleeding, post-operative complications (thrombosis), mortality, and length of hospital stay. Treatment effects were pooled using a random-effects model. Trial quality was assessed using criteria proposed by Schulz et al (Schulz 1995). Twenty-two trials of PRP were identified that reported data for the number of patients exposed to allogeneic RBC transfusion. These trials evaluated a total of 1589 patients. The relative risk (RR) of exposure to allogeneic blood transfusion in those patients randomised to PRP was 0.73 (95%CI 0.59 to 0.90), equating to a relative risk reduction (RRR) of 27% and a risk difference (RD) of 19% (95%CI 10% to 29%). However, significant heterogeneity of treatment effect was observed (p < 0.00001; I² = 79%). When the four trials by Boldt are excluded, the RR is 0.76 (95% CI 0.62 to 0.93). On average, PRP did not significantly reduce the total volume of RBC transfused (weighted mean difference [WMD] -0.69, 95%CI -1.93 to 0.56 units). Trials provided inadequate data regarding the impact of PRP on morbidity, mortality, and hospital length of stay. Trials were generally small and of poor methodological quality. Although the results suggest that PRP is effective in reducing allogeneic RBC transfusion in adult patients undergoing elective surgery, there was considerable heterogeneity of treatment effects and the trials were of poor methodological quality. The available studies provided inadequate data for firm conclusions to be drawn regarding the impact of PRP on clinically important endpoints.

Platelet-rich plasma for rotator cuff repair.

PubMed

Barber, F Alan

2013-12-01

Rotator cuff tears are a common cause of shoulder pain and disability. Because they combine both traumatic and degenerative elements, the surgical repair can be challenging. Even after surgical intervention, tendon residual defects or "retears" often develop. Risk factors for tendon "retears" include patient age, number of tendons involved, tear size, and smoking. Platelet-rich plasma (PRP) is a supraphysiological concentration of platelets, which may be able to positively augment rotator cuff tendon healing. Not all PRPs are the same and those containing higher leukocyte levels may be detrimental to tendon healing. Thrombin activation triggers an immediate release of growth factors from the PRP and may actually inhibit some parts of the healing response. As yet, the clinical data does not conclusively prove a benefit from PRP, but discernment is required in evaluating the published results. As different PRPs may act differently and the results may be dose dependent requiring more PRP to achieve a beneficial threshold. How success is measured (clinical outcomes vs. intact cuff tendons) and how long the patients are followed are also critical items. Currently, the PRP fibrin matrix version holds the greatest promise for improving clinical success after rotator cuff tendon repair.

Melatonin-mediated β-catenin activation protects neuron cells against prion protein-induced neurotoxicity.

PubMed

Jeong, Jae-Kyo; Lee, Ju-Hee; Moon, Ji-Hong; Lee, You-Jin; Park, Sang-Youel

2014-11-01

Activation of β-catenin in neurons regulates mitochondrial function and protects against protein misfolding disorders, including Alzheimer's disease and Huntington's disease. Melatonin, a natural secretory product of the pineal gland, exerts neuroprotective effects through the activation of β-catenin. In this study, melatonin increased β-catenin protein expression and activation in human neuroblastoma cell lines SH-SY5Y cells. Melatonin also inhibited PrP (106-126)-induced neurotoxicity and the inhibition attenuated by treatment of β-catenin inhibitor ICG-001. Activation of β-catenin blocked PrP (106-126)-mediated downregulation of anti-apoptotic protein survivin and Bcl-2. Reduction of mitochondrial membrane potential, translocation of Bax, and cytochrome c release which induced by PrP (106-126) treatment were inhibited by β-catenin activation, which contributed to prevented PrP (106-126)-induced neuronal cell death. In conclusion, β-catenin activation by melatonin prevented PrP (106-126)-induced neuronal cell death through regulating anti-apoptotic proteins and mitochondrial pathways. These results also suggest the therapeutic value of Wnt/β-catenin signaling in prion-related disorders as influenced by melatonin. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Spontaneous generation of rapidly transmissible prions in transgenic mice expressing wild-type bank vole prion protein.

PubMed

Watts, Joel C; Giles, Kurt; Stöhr, Jan; Oehler, Abby; Bhardwaj, Sumita; Grillo, Sunny K; Patel, Smita; DeArmond, Stephen J; Prusiner, Stanley B

2012-02-28

Currently, there are no animal models of the most common human prion disorder, sporadic Creutzfeldt-Jakob disease (CJD), in which prions are formed spontaneously from wild-type (WT) prion protein (PrP). Interestingly, bank voles (BV) exhibit an unprecedented promiscuity for diverse prion isolates, arguing that bank vole PrP (BVPrP) may be inherently prone to adopting misfolded conformations. Therefore, we constructed transgenic (Tg) mice expressing WT BVPrP. Tg(BVPrP) mice developed spontaneous CNS dysfunction between 108 and 340 d of age and recapitulated the hallmarks of prion disease, including spongiform degeneration, pronounced astrogliosis, and deposition of alternatively folded PrP in the brain. Brain homogenates of ill Tg(BVPrP) mice transmitted disease to Tg(BVPrP) mice in ∼35 d, to Tg mice overexpressing mouse PrP in under 100 d, and to WT mice in ∼185 d. Our studies demonstrate experimentally that WT PrP can spontaneously form infectious prions in vivo. Thus, Tg(BVPrP) mice may be useful for studying the spontaneous formation of prions, and thus may provide insight into the etiology of sporadic CJD.

Does platelet-rich plasma have a favorable effect in the early stages of steroid-associated femoral head osteonecrosis in a rabbit model?

PubMed

Karakaplan, Mustafa; Gülabi, Deniz; Topgül, Haldun; Elmalı, Nurzat

2017-08-01

This study aims to investigate the effect of platelet-rich plasma (PRP) on femoral head osteonecrosis and compare it with bone marrow injection and core decompression. A total of 30 healthy, adult, male New Zealand white rabbits (mean weight 2.25±0.15 kg; range 2.0 to 2.5 kg) were used in the study. To create experimental osteonecrosis in all rabbits, 40 mg/kg methylprednisolone acetate was applied intramuscularly. Rabbits were randomly allocated into three groups with 10 rabbits in each: drilling group, PRP group, and bone marrow group. The non-drilled hips of the drilling group were identified as the control group. Rate of necrotic bone was lower in the PRP group compared to other groups. Highest rate of necrotic bone was detected in the control group. New bone formation rate was higher in the PRP group compared to other groups. Lowest new bone formation rate was determined in the control group. Inflammatory reaction rate was higher in the PRP group compared to other groups. Platelet-rich plasma injection may play a positive role in the treatment of steroid-associated osteonecrosis in a rabbit model.

Comparison of different procedures to prepare platelet-rich plasma for studies of platelet aggregation by light transmission aggregometry.

PubMed

Femia, Eti Alessandra; Pugliano, Mariateresa; Podda, Gianmarco; Cattaneo, Marco

2012-01-01

Light transmission aggregometry (LTA), the gold standard for the study of patients with defects of platelet function, is a poorly standardized technique. The guidelines that have been produced so far are largely based on consensus of experts, due to the absence of studies directly comparing different procedures. Therefore, ad hoc studies are needed to gather scientific evidence on how to choose the most appropriate procedures for LTA measurement. In this study, we aimed at evaluating the most appropriate conditions for preparing samples of platelet-rich plasma (PRP) for studies of platelet aggregation by LTA. Citrate-anticoagulated blood from 32 individuals was centrifuged at 150, 200, 250 or 300×g at room temperature for 10 min. Red blood cells contamination was highest in PRP prepared at 150×g; mean platelet volume (MPV) was lowest in PRP prepared at 300×g. The extent of platelet aggregation measured by LTA was lower and more variable in PRP prepared at 300×g. Therefore, centrifugation of blood at 200×g or 250×g for 10 min appears to be the best condition for preparing PRP for LTA studies.

At-Home Application of Autologous Platelet Rich Plasma as Treatment for Pressure Sore and Related Anemia.

PubMed

Tendas, Andrea; Niscola, Pasquale; Giovannini, Marco; Costa, Adriana; Venditti, Daniela; Volta, Laura; Malandruccolo, Luigi; Sabbadini, Stefania; Lasorella, Rosa; Fabritiis, Paolo de; Cassetta, Rita; Perrotti, Alessio P

2017-01-01

Pressure sores are a major complication in the bed-ridden older patient. In this report, we present the case of platelet rich plasma (PRP) application for the treatment of a pressure sore in an 88-year-old female affected by transfusion-dependent chronic inflammatory disease anemia associated with the congenital and inherited condition of thalassemic trait carrier. A weekly application schedule was planned athome, given the patient's debilitation and her decreased performance status as well as personal and family difficulties to go as outpatients at our treatment center. After 9 PRP applications, a remarkable sore improvement was achieved so that PRP was discontinued; nevertheless, sore rapidly improved until the full resolution and the complete closing after 4 months from the start of PRP treatment. Noteworthy, transfusion support was interrupted and a significant recovery and a sustained stabilization of hemoglobin (Hb) level at 1 year after ulcer healing were observed. The present case suggests that PRP application, performed athome in our case, is a feasible and effective treatment for pressure sores and related complications. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Single-Spot Yellow Laser Versus Conventional Green Laser on Panretinal Photocoagulation: Patient Pain Scores and Preferences.

PubMed

González-Saldivar, Gerardo; Rojas-Juárez, Sergio; Espinosa-Soto, Itzel; Sánchez-Ramos, Jorge; Jaurieta-Hinojosa, Noel; Ramírez-Estudillo, Abel

2017-11-01

Panretinal photocoagulation (PRP) is the mainstay therapy for proliferative diabetic retinopathy. Pain during and after its application is a complication that affects patients' therapeutic adherence. This study aimed to compare pain perception and patient preference for the 577-nm yellow laser (YL-577) (LIGHTL as 577; LIGHTMED, San Clemente, CA) and the conventional 532-nm green laser (GL-532) (Purepoint Laser; Alcon, Fort Worth, TX) with PRP. A total of 92 patient eyes with proliferative diabetic retinopathy treated with PRP were randomly assigned to receive both GL-532 and YL-577 (184 eyes) - one on each eye, with the order of application randomized, as well. Afterward, verbal rapid answer and visual analogue scale (VAS) scores for pain perception and patient preference were evaluated. VAS score was 7 ± 2 for the GL-532 group compared to 5 ± 3 in the YL-577 group (P = .001). Overall, 75% of the patients preferred YL-577 therapy if they were to receive a second PRP session. The use of YL-577 as an alternative approach for PRP reduces pain perception and is preferred by patients. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:902-905.]. Copyright 2017, SLACK Incorporated.

Effects of platelet rich plasma on fascial healing in rats with fecal peritonitis

PubMed

Girgin, Mustafa; Binnetoglu, Kenan; Duman, Kazim; Kanat, Burhan Hakan; Cetinkaya, Ziya; Ayten, Refik; Ilhan, Yavuz Selim; Ilhan, Necip; Seker, Ibrahim; Timurkaan, Necati

2016-05-01

To evaluate the effects of platelet rich plasma (PRP) on the healing of fascia wherein peritonitis has been created. Twenty eight Wistar Albino rats were divided into four groups. Only a primary fascial repair following laparotomy was performed on Group 1, a primary fascial repair performed and PRP treatment applied following laparotomy on Group 2, and a fecal peritonitis created following laparotomy and a primary fascial repair carried out on Group 3. A fecal peritonitis was created following laparotomy and primary fascial repair and PRP treatment on the fascia was carried out on Group 4. TNF-α was found to be significantly lower in the control group (Group 1). It was detected at the highest level in the group in which fecal peritonitis was created and PRP applied (Group 4). TGF-β was determined as being significantly higher only in Group 4. Histopathologically, the differences between the groups in terms of cell infiltration and collagen deposition were not found to be significant. When platelet rich plasma was given histologically and biochemicaly as wound healing parameters cellular infiltration, collagen accumulation, and tissue hydroxyiproline levels were not increased but neovascularization, fibroblast activation and TNF Alfa levels were increased and PRP accelerated wound healing.

Editorial Commentary: Platelet-Rich Plasma: Fountain of Youth, Cart Before the Horse, or Both?

PubMed

Salzler, Matthew J

2018-05-01

Platelet-rich plasma (PRP) injections have gained widespread popularity for the treatment of many orthopaedic conditions including osteoarthritis of the knee. Despite its increasing usage, there is comparatively little evidence regarding the mechanisms of action and relative roles of the multiple growth factors contained within PRP. That said, although future research will clarify the issue, current evidence suggests that PRP is safe and, for the treatment of knee osteoarthritis, effective. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Platelet-rich plasma supplementation in arthroscopic repair of full-thickness rotator cuff tears: a randomized clinical trial.

PubMed

D'Ambrosi, R; Palumbo, F; Paronzini, A; Ragone, V; Facchini, R M

2016-12-01

Results on the effectiveness of PRP supplementation in arthroscopic rotator cuff repair are conflicting, making it difficult to draw definitive conclusions. This was a prospective, randomized, and double-blind study with two groups of 20 patients each (PRP group and control group). Degenerative supraspinatus full-thickness tears grade C2-C3 were subjected to arthroscopic repair; PRP supplementation was given to patients in the PRP group. The outcomes were assessed by DASH, Constant scales, and ultrasound before and 6 months after surgery. Pain measured by VAS was evaluated preoperatively and 7 and 30 days after surgery. The two groups did not differ significantly by age, sex, and dominance of the affected side. In all surgical procedures, a long head of the biceps tenotomy and single-row repair were performed. The preoperative VAS was 5.6 ± 2.4 in PRP group and 6.4 ± 1.5 in the control group (p > 0.05). The group supplemented with PRP reported a VAS significantly better in the first week (2.5 ± 1.9 vs 5.3 ± 2.1, p < 0.05) and during the first month after surgery (1.5 ± 1.0 vs 3.2 ± 1.7, p < 0.05) compared to the control group. The preoperative Constant and DASH scores were 39.95 ± 12 and 51 ± 15.2, respectively, in the PRP group and 41 ± 11 (p > 0.05) and 45 ± 12.6 (p > 0.05) in the control group. The average Constant score improved significantly after 6 months to 81 ± 11.2 (p < 0.05) in the PRP group and 78.5 ± 9 (p < 0.05) in the control group. No differences were noted between the two groups (p > 0.05). The DASH score after 6 months was 17.4 ± 8 (p < 0.05) for the treatment group (the PRP group) and 21 ± 8.4 (p < 0.05) for the control group. No statistically significant differences were found as regards the DASH score in the two groups after 6 months (p > 0.05). The two groups showed no differences in the ultrasound evaluation after 6 months either. No re-ruptures occurred in either group. PRP leads to a reduction in pain during a short-term follow-up. Pain reduction allows for a more rapid recovery of mobilization and improvement in functionality. Randomized controlled trial, Level of evidence, 1.

Platelet-rich plasma-induced feedback inhibition of activin A/follistatin signaling: A mechanism for tumor-low risk skin rejuvenation in irradiated rats.

PubMed

Omar, Nesreen Nabil; Rashed, Rasha R; El-Hazek, Rania M; El-Sabbagh, Walaa A; Rashed, Engy R; El-Ghazaly, Mona A

2018-03-01

Platelet-rich plasma (PRP) is a source of natural growth factors and is emerging as a treatment modality to mitigate radiotherapy- induced adverse effects. Activin A (ACTA) is a member of the transforming growth factor-β (TGF-β) superfamily, which has been shown to modulate the inflammatory response and macrophages polarization between different phenotypes. The aim of this study is to determine the value of PRP in preventing radiation-induced malignancies in light of the cross-talk between PRP and activin A type II receptors (ActR-IIA)/follistatin (FST) signaling pathways where the inflammatory responses at 2 different time points were evaluated. Male albino rats were exposed to radiation and given PRP over the course of 6 days. Rats were sacrificed on day 7 or day 28 post radiation. Quantitative real-time reverse transcriptase polymerase chain reaction (QRT-PCR) and western-blot showed that after 7 days of administrating of PRP, ActR-IIA/FST signaling was markedly induced and was associated with the expressions of inflammatory, natural killer and M1 macrophages markers, TNF-α, IL-1β, IFN-γ and IL-12. By contrast, on day 28 of PRP administration, ActR-IIA/FST signaling and the expressions of proinflammatory cytokines were downregulated in parallel with inducing M2 macrophages phenotype as indicated by arginase-1, IL-10 and dectin-1. The suppression of inflammation and induction of M2 macrophages phenotype in response to PRP administration were found significantly linked to ActR-IIA/FST signaling downregulation. Furthermore, the specific M2 macrophage subtype was found to express dectin-1 receptors which have high affinity for tumor cells thereby is expected to reduce the potential for developing tumors after radiotherapy. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of bone marrow aspirate concentrate and platelet-rich plasma on patients with partial tear of the rotator cuff tendon.

PubMed

Kim, Sang Jun; Kim, Eun Kyung; Kim, Sun Jeong; Song, Da Hyun

2018-01-03

We compared the clinical course of rotator cuff tears between rotator cuff exercise and bone marrow aspirate concentration (BMAC)-platelet rich plasma (PRP) injection to identify the therapeutic effects of BMAC-PRP on partial tear of the rotator cuff tendon. Twenty-four patients with partial tear of the rotator cuff tendon participated in this study. Twelve patients underwent extraction of BMACs and PRP and received the injection of BMAC-PRP at the tear site under ultrasound guidance. Twelve patients in the control group were asked to perform the rotator cuff exercise for 3 months. Visual analog scale (VAS) and manual muscle test (MMT) scores of the supraspinatus muscle were measured, and the American Shoulder and Elbow Surgeons (ASES) score was recorded before, 3 weeks, and 3 months after injection. Tear size was measured by the greatest longitudinal tear length. The change in the VAS differed between groups at 3 months (P = 0.039) but not at 3 weeks (P = 0.147). The ASES scores in the BMAC-PRP group changed from 39.4 ± 13.0 to 54.5 ± 11.5 at 3 weeks and 74.1 ± 8.5 at 3 months while those in the control group changed from 45.9 ± 12.4 to 56.3 ± 12.3 at 3 weeks (P = 0.712) and 62.2 ± 12.2 at 3 months (P = 0.011). The tear size decreased at 3 weeks or 3 months after the BMAC-PRP injection but was not significantly different from that in the control group. BMAC-PRP improved pain and shoulder function in patients with partial tear of the rotator cuff tendon. The patients were registered in the institutional board registry of Samsung Medical Center (registry number 2014-07-173 ).

Prion Strain Characterization of a Novel Subtype of Creutzfeldt-Jakob Disease.

PubMed

Galeno, Roberta; Di Bari, Michele Angelo; Nonno, Romolo; Cardone, Franco; Sbriccoli, Marco; Graziano, Silvia; Ingrosso, Loredana; Fiorini, Michele; Valanzano, Angelina; Pasini, Giulia; Poleggi, Anna; Vinci, Ramona; Ladogana, Anna; Puopolo, Maria; Monaco, Salvatore; Agrimi, Umberto; Zanusso, Gianluigi; Pocchiari, Maurizio

2017-06-01

In 2007, we reported a patient with an atypical form of Creutzfeldt-Jakob disease (CJD) heterozygous for methionine-valine (MV) at codon 129 who showed a novel pathological prion protein (PrP TSE ) conformation with an atypical glycoform (AG) profile and intraneuronal PrP deposition. In the present study, we further characterize the conformational properties of this pathological prion protein (PrP TSE MV AG ), showing that PrP TSE MV AG is composed of multiple conformers with biochemical properties distinct from those of PrP TSE type 1 and type 2 of MV sporadic CJD (sCJD). Experimental transmission of CJD-MV AG to bank voles and gene-targeted transgenic mice carrying the human prion protein gene (TgHu mice) showed unique transmission rates, survival times, neuropathological changes, PrP TSE deposition patterns, and PrP TSE glycotypes that are distinct from those of sCJD-MV1 and sCJD-MV2. These biochemical and experimental data suggest the presence of a novel prion strain in CJD-MV AG IMPORTANCE Sporadic Creutzfeldt-Jakob disease is caused by the misfolding of the cellular prion protein, which assumes two different major conformations (type 1 and type 2) and, together with the methionine/valine polymorphic codon 129 of the prion protein gene, contribute to the occurrence of distinct clinical-pathological phenotypes. Inoculation in laboratory rodents of brain tissues from the six possible combinations of pathological prion protein types with codon 129 genotypes results in the identification of 3 or 4 strains of prions. We report on the identification of a novel strain of Creutzfeldt-Jakob disease isolated from a patient who carried an abnormally glycosylated pathological prion protein. This novel strain has unique biochemical characteristics, does not transmit to humanized transgenic mice, and shows exclusive transmission properties in bank voles. The identification of a novel human prion strain improves our understanding of the pathogenesis of the disease and of possible mechanisms of prion transmission. Copyright © 2017 American Society for Microbiology.

Safety and Efficacy of Intra-articular Injection of Platelet-Rich Plasma in Patients With Ankle Osteoarthritis.

PubMed

Fukawa, Taisuke; Yamaguchi, Satoshi; Akatsu, Yorikazu; Yamamoto, Yohei; Akagi, Ryuichiro; Sasho, Takahisa

2017-06-01

An intra-articular injection of platelet-rich plasma (PRP) may be an effective treatment for osteoarthritis (OA). However, its efficacy in ankle OA has not been investigated yet. The purpose of this study was to assess the safety and efficacy of an intra-articular injection of PRP in patients with ankle OA during a 24-week period. Twenty ankles of 20 patients with varus-type ankle OA who received intra-articular injections of PRP were evaluated. PRP was extracted from whole blood by using the double-spin technique. Three injections of 2-mL PRP were administered to the ankle at an interval of 2 weeks under ultrasonographic guidance. Adverse events and efficacy were assessed at 4, 12, and 24 weeks after the last injection. Clinical outcomes were assessed by using the visual analog scale (VAS) for pain, the Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot scale, and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q). No serious adverse effects were observed during the follow-up period. The VAS and JSSF scale scores significantly decreased from baseline to 4, 12, and 24 weeks after treatment ( P < .001). The mean score in the pain-related subscale of the SAFE-Q significantly improved from baseline to 12 weeks after treatment ( P = .04). Overall, the amount of pain reduction was maximal at 12 weeks after the last injection, and the effect was reduced at 24 weeks. The patients with late-stage OA had worse scores in all outcomes than those with early-stage OA. Intra-articular injections of PRP resulted in no serious adverse effects and significantly reduced pain in the patients with ankle OA. PRP treatment can be safe and effective and may be an option in the treatment of ankle OA. Level IV, case series.

Eccentric Training for Tendon Healing After Acute Lesion: A Rat Model.

PubMed

Kaux, Jean-François; Libertiaux, Vincent; Leprince, Pierre; Fillet, Marianne; Denoel, Vincent; Wyss, Clémence; Lecut, Christelle; Gothot, André; Le Goff, Caroline; Croisier, Jean-Louis; Crielaard, Jean-Michel; Drion, Pierre

2017-05-01

The tendon is a dynamic entity that remodels permanently. Platelet-rich plasma (PRP) injection has been shown to have a beneficial effect on tendon healing after lesion in rats. Furthermore, eccentric exercise seems to improve the mechanical quality of the tendon. A combination of PRP injection and eccentric training might be more effective than either treatment alone. Controlled laboratory study. Adult male rats were anesthetized, an incision was performed in the middle of their left patellar tendon and an injection of physiological fluid (PF) or homologous PRP was randomly made at the lesion level. The rats were then divided into 2 groups: the eccentric group, undergoing eccentric training 3 times a week, and the untrained group, without any training. Thus, 4 groups were compared. After 5 weeks, the tendons were removed and their ultimate tensile strength and energy were measured. Tendons were frozen for proteomic analyses when all biomechanical tests were completed. Statistical analysis was performed with linear mixed effect models. No significant difference was found between the treatments using PF injection or PRP injection alone. However, the value of the ultimate tensile force at rupture was increased by 4.5 N (108% of control, P = .006) when eccentric training was performed. An intragroup analysis revealed that eccentric training significantly improved the ultimate force values for the PRP group. Proteomic analysis revealed that eccentric training led to an increase in abundance of several cytoskeletal proteins in the PF group, while a decrease in abundance of enzymes of the glycolytic pathway occurred in the PRP-treated groups, indicating that this treatment might redirect the exercise-driven metabolic plasticity of the tendon. Eccentric training altered the metabolic plasticity of tendon and led to an improvement of injured tendon resistance regardless of the treatment injected (PF or PRP). This study demonstrates the necessity of eccentric rehabilitation and training in cases of tendon lesion regardless of the treatment carried out.

Absence of Evidence for a Causal Link between Bovine Spongiform Encephalopathy Strain Variant L-BSE and Known Forms of Sporadic Creutzfeldt-Jakob Disease in Human PrP Transgenic Mice.

PubMed

Jaumain, Emilie; Quadrio, Isabelle; Herzog, Laetitia; Reine, Fabienne; Rezaei, Human; Andréoletti, Olivier; Laude, Hubert; Perret-Liaudet, Armand; Haïk, Stéphane; Béringue, Vincent

2016-12-01

Prions are proteinaceous pathogens responsible for subacute spongiform encephalopathies in animals and humans. The prions responsible for bovine spongiform encephalopathy (BSE) are zoonotic agents, causing variant Creutzfeldt-Jakob disease (CJD) in humans. The transfer of prions between species is limited by a species barrier, which is thought to reflect structural incompatibilities between the host cellular prion protein (PrP C ) and the infecting pathological PrP assemblies (PrP Sc ) constituting the prion. A BSE strain variant, designated L-BSE and responsible for atypical, supposedly spontaneous forms of prion diseases in aged cattle, demonstrates zoonotic potential, as evidenced by its capacity to propagate more easily than classical BSE in transgenic mice expressing human PrP C and in nonhuman primates. In humanized mice, L-BSE propagates without any apparent species barrier and shares similar biochemical PrP Sc signatures with the CJD subtype designated MM2-cortical, thus opening the possibility that certain CJD cases classified as sporadic may actually originate from L-type BSE cross-transmission. To address this issue, we compared the biological properties of L-BSE and those of a panel of CJD subtypes representative of the human prion strain diversity using standard strain-typing criteria in human PrP transgenic mice. We found no evidence that L-BSE causes a known form of sporadic CJD. Since the quasi-extinction of classical BSE, atypical BSE forms are the sole BSE variants circulating in cattle worldwide. They are observed in rare cases of old cattle, making them difficult to detect. Extrapolation of our results suggests that L-BSE may propagate in humans as an unrecognized form of CJD, and we urge both the continued utilization of precautionary measures to eliminate these agents from the human food chain and active surveillance for CJD phenotypes in the general population. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

The effect of platelet-rich plasma on the repair of muscle injuries in rats☆

PubMed Central

Quarteiro, Marcelo Luiz; Tognini, João Ricardo Filgueiras; de Oliveira, Everton Lucas Flores; Silveira, Izabelli

2015-01-01

Objective The need for therapeutic options for muscle injuries, which are increasingly frequent among sports practitioners, was the motivation for this experimental study, which had the aim of evaluating the histological effects of platelet-rich plasma (PRP) on repairs to muscle tissues of rats. Methods PRP was obtained by means of double centrifugation of blood from five animals. In 30 rats, an injury was produced in the middle third of the belly of the gastrocnemius muscle of each hind limb. These injuries did not receive any treatment in six rats (12 legs). In 24 rats, 0.9% physiological serum was injected into the injury in the left leg and PRP into the injury in the right leg. Samples from the treated and untreated tissue were evaluated histologically 7 and 21 days after the procedures. Results The quantity of collagen in the injuries treated with PRP was significantly lower than that in the other injuries, in the evaluation made 7 days after the procedure, but it became equal to the other groups in the evaluation done on the 21st day. There was a significant increase (p < 0.001) in the quantity of collagen from the 7th to the 21st day in the injuries treated with PRP, but this was not seen in the injuries treated using other methods. The inflammatory process was shown to be more intense in the injuries treated with PRP than in the injuries of the other treatment groups, in the evaluation done 7 days after the procedure. However, the morphological aspects of these injuries were seen to be similar to those of the untreated injuries, 21 days after the procedure. Conclusion PRP promoted complete tissue restitution between the 7th and 21st days in experimental muscle injuries. PMID:26535207

Effect of acoustic parameters on the cavitation behavior of SonoVue microbubbles induced by pulsed ultrasound.

PubMed

Lin, Yutong; Lin, Lizhou; Cheng, Mouwen; Jin, Lifang; Du, Lianfang; Han, Tao; Xu, Lin; Yu, Alfred C H; Qin, Peng

2017-03-01

SonoVue microbubbles could serve as artificial nuclei for ultrasound-triggered stable and inertial cavitation, resulting in beneficial biological effects for future therapeutic applications. To optimize and control the use of the cavitation of SonoVue bubbles in therapy while ensuring safety, it is important to comprehensively understand the relationship between the acoustic parameters and the cavitation behavior of the SonoVue bubbles. An agarose-gel tissue phantom was fabricated to hold the SonoVue bubble suspension. 1-MHz transmitting transducer calibrated by a hydrophone was used to trigger the cavitation of SonoVue bubbles under different ultrasonic parameters (i.e., peak rarefactional pressure (PRP), pulse repetition frequency (PRF), and pulse duration (PD)). Another 7.5-MHz focused transducer was employed to passively receive acoustic signals from the exposed bubbles. The ultraharmonics and broadband intensities in the acoustic emission spectra were measured to quantify the extent of stable and inertial cavitation of SonoVue bubbles, respectively. We found that the onset of both stable and inertial cavitation exhibited a strong dependence on the PRP and PD and a relatively weak dependence on the PRF. Approximate 0.25MPa PRP with more than 20μs PD was considered to be necessary for ultraharmonics emission of SonoVue bubbles, and obvious broadband signals started to appear when the PRP exceeded 0.40MPa. Moreover, the doses of stable and inertial cavitation varied with the PRP. The stable cavitation dose initially increased with increasing PRP, and then decreased rapidly after 0.5MPa. By contrast, the inertial cavitation dose continuously increased with increasing PRP. Finally, the doses of both stable and inertial cavitation were positively correlated with PRF and PD. These results could provide instructive information for optimizing future therapeutic applications of SonoVue bubbles. Copyright © 2016 Elsevier B.V. All rights reserved.

Exploratory clinical trial of combination wound therapy with a gelatin sheet and platelet-rich plasma in patients with chronic skin ulcers: study protocol.

PubMed

Morimoto, Naoki; Kakudo, Natsuko; Matsui, Makoto; Ogura, Tsunetaka; Hara, Tomoya; Suzuki, Kenji; Yamamoto, Masaya; Tabata, Yasuhiko; Kusumoto, Kenji

2015-05-11

Chronic skin ulcers, such as diabetic ulcers, venous leg ulcers and pressure ulcers, are intractable and increasing in prevalence, representing a costly problem in healthcare. We developed a combination therapy with a gelatin sheet, capable of providing sustained release of platelet-rich plasma (PRP). The objective of this study is to investigate the safety and efficacy of autologous PRP covered with a hydrocolloid dressing and PRP covered with a gelatin sheet in the treatment of chronic skin ulcers. Thirty patients with chronic skin ulcers who have not healed with conventional therapy for at least 1 month are being recruited. The patients will receive PRP after debridement, and the wounds will be covered with a hydrocolloid dressing or gelatin sheet. The efficacy will be evaluated according to the time from the beginning of PRP application to secondary healing or the day on which wound closure is achieved with a relatively simple surgical procedure, such as skin grafting or suturing. All patients will be followed up until 6 weeks after application to observe adverse events related to the application of PRP and the dressings. This study was designed to address and compare the safety and efficacy of PRP covered with a hydrocolloid dressing versus a gelatin sheet. If successful, this combination therapy may be an alternative to bioengineered skin substitutes containing living cells and lead to substantial progress in the management of chronic skin ulcers. The study protocol was approved by the Institutional Review Board of Kansai Medical University (KMU Number 0649-1, 4 August 2014: V.1.0). The findings of this trial will be disseminated through peer-reviewed journals, and national and international scientific meetings as well as to the patients. UMIN000015689. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Cooperative binding modes of Cu(II) in prion protein

NASA Astrophysics Data System (ADS)

Hodak, Miroslav; Chisnell, Robin; Lu, Wenchang; Bernholc, Jerry

2007-03-01

The misfolding of the prion protein, PrP, is responsible for a group of neurodegenerative diseases including mad cow disease and Creutzfeldt-Jakob disease. It is known that the PrP can efficiently bind copper ions; four high-affinity binding sites located in the octarepeat region of PrP are now well known. Recent experiments suggest that at low copper concentrations new binding modes, in which one copper ion is shared between two or more binding sites, are possible. Using our hybrid Thomas-Fermi/DFT computational scheme, which is well suited for simulations of biomolecules in solution, we investigate the geometries and energetics of two, three and four binding sites cooperatively binding one copper ion. These geometries are then used as inputs for classical molecular dynamics simulations. We find that copper binding affects the secondary structure of the PrP and that it stabilizes the unstructured (unfolded) part of the protein.

Characterization of PhPRP1, a histidine domain arabinogalactan protein from Petunia hybrida pistils.

PubMed

Twomey, Megan C; Brooks, Jenna K; Corey, Jillaine M; Singh-Cundy, Anu

2013-10-15

An arabinogalactan protein, PhPRP1, was purified from Petunia hybrida pistils and shown to be orthologous to TTS-1 and TTS-2 from Nicotiana tabacum and NaTTS from Nicotiana alata. Sequence comparisons among these proteins, and CaPRP1 from Capsicum annuum, reveal a conserved histidine-rich domain and two hypervariable domains. Immunoblots show that TTS-1 and PhPRP1 are also expressed in vegetative tissues of tobacco and petunia respectively. In contrast to the molecular mass heterogeneity displayed by the pistil proteins, the different isoforms found in seedlings, roots, and leaves each has a discrete size (37, 80, 160, and 200 kDa) on SDS-PAGE gels. On the basis of their chemistry, distinctive domain architecture, and the unique pattern of expression, we have named this group of proteins HD-AGPs (histidine domain-arabinogalactan proteins). Copyright © 2013 Elsevier GmbH. All rights reserved.

Relationship between naturally occurring human mucosal and serum antibody to the capsular polysaccharide of Haemophilus influenzae type b.

PubMed

Pichichero, M E; Insel, R A

1982-08-01

The prevalence of natural mucosal antibody to the capsular polysaccharide (polyribosylribitolphosphate [PRP]) of Haemophilus influenzae type b in adults at multiple secretory sites and the relationship between natural serum and mucosal antibodies with respect to their amount and fine binding specificity were examined. All of 16 lactating women had antibody to PRP in serum and mammary samples; 11 of 14 studied had nasal antibody and 12 of 14 had salivary antibody. The amount of serum antibody to PRP in an individual positively correlated with the amount of mucosal antibody at each of the three secretory sites examined, and the antibody amount between certain secretions were also positively correlated. Antibody to PRP that is cross-reactive with Escherichia coli K100 or Streptococcus pneumoniae type 6 capsular polysaccharides was detected in the secretions of seven and one subjects, respectively, but the amount was not correlated with serum cross-reactive antibody.

The clinical evaluation of platelet-rich plasma on free gingival graft's donor site wound healing.

PubMed

Samani, Mahmoud Khosravi; Saberi, Bardia Vadiati; Ali Tabatabaei, S M; Moghadam, Mahdjoube Goldani

2017-01-01

It has been proved that platelet-rich plasma (PRP) can promote wound healing. In this way, PRP can be advantageous in periodontal plastic surgeries, free gingival graft (FGG) being one such surgery. In this randomized split-mouth controlled trial, 10 patients who needed bilateral FGG were selected, and two donor sites were randomly assigned to experience either natural healing or healing-assisted with PRP. The outcome was assessed based on the comparison of the extent of wound closure, Manchester scale, Landry healing scale, visual analog scale, and tissue thickness between the study groups at different time intervals. Repeated measurements of analysis of variance and paired t -test were used. Statistical significance was P ≤ 0.05. Significant differences between the study groups and also across different time intervals were seen in all parameters except for the changes in tissue thickness. PRP accelerates the healing process of wounds and reduces the healing time.

Susceptibility to Dental Caries and the Salivary Proline-Rich Proteins

PubMed Central

Levine, Martin

2011-01-01

Early childhood caries affects 28% of children aged 2–6 in the US and is not decreasing. There is a well-recognized need to identify susceptible children at birth. Caries-free adults neutralize bacterial acids in dental biofilms better than adults with severe caries. Saliva contains acidic and basic proline-rich proteins (PRPs) which attach to oral streptococci. The PRPs are encoded within a small region of chromosome 12. An acidic PRP allele (Db) protects Caucasian children from caries but is more common in African Americans. Some basic PRP allelic phenotypes have a three-fold greater frequency in caries-free adults than in those with severe caries. Early childhood caries may associate with an absence of certain basic PRP alleles which bind oral streptococci, neutralize biofilm acids, and are in linkage disequilibrium with Db in Caucasians. The encoding of basic PRP alleles is updated and a new technology for genotyping them is described. PMID:22190937