The Influence of Interleukin-4 on Ligament Healing

PubMed Central

Chamberlain, Connie S; Leiferman, Ellen M; Frisch, Kayt E; Wang, Sijian; Yang, Xipei; Brickson, Stacey L; Vanderby, Ray

2011-01-01

Despite a complex cascade of cellular events to reconstruct the damaged extracellular matrix, ligament healing results in a mechanically inferior scarred ligament. During normal healing, granulation tissue expands into any residual normal ligamentous tissue (creeping substitution), resulting in a larger region of healing, greater mechanical compromise, and an inefficient repair process. To control creeping substitution and possibly enhance the repair process, the anti-inflammatory cytokine, interleukin-4 (IL-4) was administered to rats prior to and after rupture of their medial collateral ligaments. In vitro experiments demonstrated a time-dependent effect on fibroblast proliferation after interleukin-4 treatment. In vivo treatments with interleukin-4 (100 ng/ml i.v.) for 5 days resulted in decreased wound size and type III collagen and increased type I procollagen, indicating a more regenerative early healing in response to the interleukin-4 treatment. However, continued treatment of interleukin-4 to day 11 antagonized this early benefit and slowed healing. Together, these results suggest that interleukin-4 influences the macrophages and T-lymphocytes but also stimulates fibroblasts associated with the proliferative phase of healing in a dose-, cell-, and time-dependent manner. Although treatment significantly influenced healing in the first week after injury, interleukin-4 alone was unable to maintain this early regenerative response. PMID:21518087

The suitability of human adipose-derived stem cells for the engineering of ligament tissue.

PubMed

Eagan, Michael J; Zuk, Patricia A; Zhao, Ke-Wei; Bluth, Benjamin E; Brinkmann, Elyse J; Wu, Benjamin M; McAllister, David R

2012-10-01

Rupture of the anterior cruciate ligament (ACL) is the one of the most common sports-related injuries. With its poor healing capacity, surgical reconstruction using either autografts or allografts is currently required to restore function. However, serious complications are associated with graft reconstructions and the number of such reconstructions has steadily risen over the years, necessitating the search for an alternative approach to ACL repair. Such an approach may likely be tissue engineering. Recent engineering approaches using ligament-derived fibroblasts have been promising, but the slow growth rate of such fibroblasts in vitro may limit their practical application. More promising results are being achieved using bone marrow mesenchymal stem cells (MSCs). The adipose-derived stem cell (ASC) is often proposed as an alternative choice to the MSC and, as such, may be a suitable stem cell for ligament engineering. However, the use of ASCs in ligament engineering still remains relatively unexplored. Therefore, in this study, the potential use of human ASCs in ligament tissue engineering was initially explored by examining their ability to express several ligament markers under growth factor treatment. ASC populations treated for up to 4 weeks with TGFβ1 or IGF1 did not show any significant and consistent upregulation in the expression of collagen types 1 and 3, tenascin C and scleraxis. While treatment with EGF or bFGF resulted in increased tenascin C expression, increased expression of collagens 1 and 3 were never observed. Therefore, simple in vitro treatment of human ASC populations with growth factors may not stimulate their ligament differentiative potential. Copyright © 2011 John Wiley & Sons, Ltd.

Cytokeratin expression of engrafted three-dimensional culture tissues using epithelial cells derived from porcine periodontal ligaments.

PubMed

Yamada, Rie; Kitajima, Kayoko; Arai, Kyoko; Igarashi, Masaru

2014-09-01

This study investigated the differentiation and proliferation of epithelial cells derived from periodontal ligaments after three-dimensional culture using collagen gel with fibroblasts in vitro and in vivo. Epithelial cells and fibroblasts were derived from porcine periodontal ligaments. Epithelial cells were labeled using a fluorescent red membrane marker (PKH-26GL) and were seeded onto collagen gel with fibroblasts, followed by incubation in an air-liquid interface for 7 days. Three-dimensional cultures were grafted onto the backs of nude mice and removed at 1, 7, and 14 days after surgery (in vivo model). Unfixed sections (5 μm) were used to detect the presence of red fluorescent cells. Paraffin sections were analyzed histologically and immunohistochemically. Specimens were compared with three-dimensional culture tissues at 8, 14 and 21 days (in vitro model). Grafted three-dimensional cultures formed a stratified epithelial structure similar to skin in vivo. Epithelial cells were sequenced in basal-layer-like structures at 14 days in vivo. Immunohistochemical findings showed that the expression of cytokeratin was detected in the epithelial layer in in vitro and in vivo models. Ck8 + 18 + 19 was expressed in the upper epithelial layer in the in vitro model at 14 and 21 days, but not in vivo. Involucrin was expressed in the certified layers in vitro at 14 days, but not in vivo. Laminin was detected at the dermo-epidermal junction in vivo at 7 and 14 days, but not in vitro. These results suggest that differentiation of three-dimensional culture tissues differs in vivo and in vitro. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Matrix metalloproteinase inhibition reduces contraction by dupuytren fibroblasts.

PubMed

Townley, William A; Cambrey, Alison D; Khaw, Peng T; Grobbelaar, Adriaan O

2008-11-01

Dupuytren's disease is a common fibroproliferative condition of the hand characterized by fibrotic lesions (nodules and cords), leading to disability through progressive digital contracture. Although the etiology of the disease is poorly understood, recent evidence suggests that abnormal matrix metalloproteinase (MMP) activity may play a role in cell-mediated collagen contraction and tissue scarring. The aim of this study was to investigate the efficacy of ilomastat, a broad-spectrum MMP inhibitor, in an in vitro model of Dupuytren fibroblast-mediated contraction. Nodule-derived and cord-derived fibroblasts were isolated from Dupuytren patients; carpal ligament-derived fibroblasts acted as control. Stress-release fibroblast-populated collagen lattices (FPCLs) were used as a model of contraction. FPCLs were allowed to develop mechanical stress (48 hours) during treatment with ilomastat (0-100 micromol/L), released, and allowed to contract over a 48-hour period. Contraction was estimated by measuring lattice area compared with untreated cells or treatment with a control peptide. MMP-1, MMP-2, and MT1-MMP levels were assessed by zymography, Western blotting, and enzyme-linked immunosorbent assay. Nodule-derived fibroblasts contracted lattices (69% +/- 2) to a greater extent than did cord-derived (55% +/- 3) or carpal ligament-derived (55% +/- 1) fibroblasts. Exposure to ilomastat led to significant inhibition of lattice contraction by all fibroblasts, although a reduction in lattice contraction by nodule-derived fibroblasts was most prominent (84% +/- 8). In addition, treatment with ilomastat led to a concomitant suppression of MMP-1 and MMP-2 activity, whereas MT1-MMP activity was found to be upregulated. Our results demonstrate that inhibition of MMP activity results in a reduction in extracellular matrix contraction by Dupuytren fibroblasts and suggest that MMP activity may be a critical target in preventing recurrent contracture caused by this disease.

Protein kinase-A-dependent osteoprotegerin production on interleukin-1 stimulation in human gingival fibroblasts is distinct from periodontal ligament fibroblasts

PubMed Central

Hormdee, D; Nagasawa, T; Kiji, M; Yashiro, R; Kobayashi, H; Koshy, G; Noguchi, K; Nitta, H; Ishikawa, I

2005-01-01

Periodontitis, a chronic inflammatory disease, is characterized by increased expression of interleukin (IL)-1 and other inflammatory mediators resulting in extensive osteoclast formation and bone loss. Expression of receptor activator of nuclear factor kappa B ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG), by osteoblasts is important to regulate osteoclast differentiation. The aim of the present study was to investigate the regulatory effects of IL-1 on RANKL and OPG production by mesenchymal fibroblasts in periodontal tissue. Human gingival fibroblasts (HGF) and periodontal ligament fibroblasts (PDL) were stimulated with IL-1α with or without protein synthesis inhibitor cycloheximide (CHX), protein kinase A (PKA) inhibitors, protein kinase C (PKC) inhibitors and prostaglandin E2 (PGE2) inhibitor. In some experiments, the cultured cells were directly stimulated with either PKA or PKC activators. In HGF, IL-1α-stimulated OPG mRNA expression was high and could be reduced by CHX. PKA inhibitor completely abrogated IL-1α-induced OPG mRNA expression and OPG production. Endogenous PGE2 further enhanced IL-1α-induced OPG production in HGF. In PDL, RANKL mRNA expression was greatly augmented by IL-1α. IL-1α induced OPG mRNA expression and protein production. PKC inhibitor partially reduced IL-1α-induced OPG production and PKC activator enhanced OPG production in PDL. The IL-1α-stimulated OPG mRNA expression in HGF was greater than PDL. These results provide new evidence for the possible osteoclastogenesis-inhibitory function of HGF through PKA activity pathway. PDL utilized PKC for OPG production. Thus, we emphasize that HGF and PDL have different characteristics of host defence mechanism against inflammatory process. PMID:16297161

The attachment of V79 and human periodontal ligament fibroblasts on periodontally involved root surfaces following treatment with EDTA, citric acid, or tetracycline HCL: an SEM in vitro study.

PubMed

Chandra, R Viswa; Jagetia, Ganesh Chandra; Bhat, K Mahalinga

2006-02-15

The present in vitro study has been designed to establish and compare the effects of citric acid, EDTA, and tetracycline HCl on human periodontally diseased roots on the structure, attachment, and orientation of V79 (primary Chinese hamster lung fibroblasts) cells and human periodontal ligament fibroblasts (HPDL). Commercially available V79 cells and HPDL derived from healthy human third molars were used in this study. These fibroblasts were left in solution for seven days in order to attain confluence. Forty single-rooted teeth were obtained from patients diagnosed with periodontitis. The crown part was removed under constant irrigation and the root was split vertically into two equal halves, thus, yielding 80 specimens. Following scaling and root planing, the specimens were washed with phosphate buffered saline (PBS) and kept in 50 microg/ml gentamycin sulphate solution for 24 hours. The root pieces were then treated as follows: citric acid at pH 1, 24% EDTA, or with a 10% solution of tetracycline HCl and were then placed in V79 fibroblast cultures and HPDL cultures. The specimens were harvested after four weeks and were fixed in 2.5% glutaraldehyde in PBS before preparation for scanning electron microscopy (SEM). The behavior of V79 cells was similar to that of human periodontal ligament cells on root conditioned surfaces. V79 and HPDL showed a healthy morphology on root surfaces treated with citric acid and EDTA and a relatively unhealthy appearance on root surfaces treated with tetracycline HCl and distilled water (control group). The results suggest the use of citric acid and EDTA as root conditioning agents favorably affects the migration, attachment, and morphology of fibroblasts on human root surfaces, which may play a significant role in periodontal healing and regeneration.

Cytotoxicity evaluation of sodium alendronate on cultured human periodontal ligament fibroblasts.

PubMed

Correia, Vera de Fátima Padrão; Caldeira, Celso L; Marques, Márcia Martins

2006-12-01

External root resorption processes are usually associated with dental trauma, mainly avulsion and intrusion. In such cases endodontic therapy aims to prevent this process by using medications that can inhibit osteoclastic activity, such as bisphosphonates. However, these drugs must be biocompatible to the periapical tissues. The aim of this study was to analyze the cytotoxicity of a bisphosphonate (sodium alendronate) on human periodontal ligament fibroblasts (PDL cells). Cells were plated in a density of 1 x 10(3) cells per dish. The experimental groups were GI (control) no sodium alendronate, and GII, GIII, and GIV with sodium alendronate at the concentrations of 10(-5), 10(-6), and 10(-7) M, respectively. The experimental times were 1, 6, 12, and 24 h (short-term) for viability and 2, 4, 6, and 8 days (long-term) for cell survival. Data in triplicate were statistically analyzed. Cultures treated with the highest alendronate concentration (GII) showed cell viability percentages significantly lower (P < 0.01) than those of the other groups (GI, GIII, and GIV), at 12 and 24 h. Cell growth on GII and GIII groups was similar. GII presented smaller growth than the other groups (P < 0.05). We concluded that sodium alendronate, on direct contact with human periodontal ligament fibroblasts, is cytotoxic in concentrations higher than of 10(-6) M.

Combined effects of tumor necrosis factor-α and interleukin-1β on lysyl oxidase and matrix metalloproteinase expression in human knee synovial fibroblasts in vitro

PubMed Central

Zhang, Yanjun; Jiang, Jiahuan; Xie, Jing; Xu, Chunming; Wang, Chunli; Yin, Lin; Yang, Li; Sung, Kuo-Li Paul

2017-01-01

Previous studies have demonstrated that inflammatory cytokines are associated with matrix metalloproteinases (MMPs) and/or lysyl oxidases (LOXs) produced by anterior cruciate ligament (ACL) fibroblasts, which may contribute to the poor healing ability of the ACL. To evaluate whether the synovium also participates in ACL healing, the inflammatory microenvironment of the knee joint cavity was mimicked following ACL injury, and the combined effects of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) on the expression of MMPs and LOXs in synovial fibroblasts were studied. Cell viability was evaluated using trypan blue staining in the presence of TNF-α and IL-1β, and the expression of LOXs and MMPs was measured by reverse transcription-quantitative polymerase chain reaction. MMP-2 activity was also measured by zymography. The results indicated that the combined effects of TNF-α and IL-1β inhibited LOX expression, while promoting MMP-1, −2 and −3 expression and MMP-2 activity in synovial fibroblasts. These changes may impede healing by altering the balance between the degradative and biosynthetic arms of the ligament tissue remodeling process. Collectively, the present results suggest that the poor healing ability of cruciate ligaments may be due to the sensitivity of the synovium to inflammatory factors. Therefore, the synovium potentially serves a key regulatory role in the joint cavity microenvironment and in the healing process of the ACL, and thus should be considered as a therapeutic target to aid in the treatment of patients with ACL trauma. PMID:29285051

A simple combined floating and anchored collagen gel for enhancing mechanical strength of culture system.

PubMed

Harada, Ichiro; Kim, Sung-Gon; Cho, Chong Su; Kurosawa, Hisashi; Akaike, Toshihiro

2007-01-01

In this study, a simple combined method consisting of floating and anchored collagen gel in a ligament or tendon equivalent culture system was used to produce the oriented fibrils in fibroblast-populated collagen matrices (FPCMs) during the remodeling and contraction of the collagen gel. Orientation of the collagen fibrils along single axis occurred over the whole area of the floating section and most of the fibroblasts were elongated and aligned along the oriented collagen fibrils, whereas no significant orientation of fibrils was observed in normally contracted FPCMs by the floating method. Higher elasticity and enhanced mechanical strength were obtained using our simple method compared with normally contracted floating FPCMs. The Young's modulus and the breaking point of the FPCMs were dependent on the initial cell densities. This simple method will be applied as a convenient bioreactor to study cellular processes of the fibroblasts in the tissues with highly oriented fibrils such as ligaments or tendons. (c) 2006 Wiley Periodicals, Inc.

Ligament Tissue Engineering Using a Novel Porous Polycaprolactone Fumarate Scaffold and Adipose Tissue-Derived Mesenchymal Stem Cells Grown in Platelet Lysate.

PubMed

Wagner, Eric R; Bravo, Dalibel; Dadsetan, Mahrokh; Riester, Scott M; Chase, Steven; Westendorf, Jennifer J; Dietz, Allan B; van Wijnen, Andre J; Yaszemski, Michael J; Kakar, Sanjeev

2015-11-01

Surgical reconstruction of intra-articular ligament injuries is hampered by the poor regenerative potential of the tissue. We hypothesized that a novel composite polymer "neoligament" seeded with progenitor cells and growth factors would be effective in regenerating native ligamentous tissue. We synthesized a fumarate-derivative of polycaprolactone fumarate (PCLF) to create macro-porous scaffolds to allow cell-cell communication and nutrient flow. Clinical grade human adipose tissue-derived human mesenchymal stem cells (AMSCs) were cultured in 5% human platelet lysate (PL) and seeded on scaffolds using a dynamic bioreactor. Cell growth, viability, and differentiation were examined using metabolic assays and immunostaining for ligament-related markers (e.g., glycosaminoglycans [GAGs], alkaline phosphatase [ALP], collagens, and tenascin-C). AMSCs seeded on three-dimensional (3D) PCLF scaffolds remain viable for at least 2 weeks with proliferating cells filling the pores. AMSC proliferation rates increased in PL compared to fetal bovine serum (FBS) (p < 0.05). Cells had a low baseline expression of ALP and GAG, but increased expression of total collagen when induced by the ligament and tenogenic growth factor fibroblast growth factor 2 (FGF-2), especially when cultured in the presence of PL (p < 0.01) instead of FBS (p < 0.05). FGF-2 and PL also significantly increased immunostaining of tenascin-C and collagen at 2 and 4 weeks compared with human fibroblasts. Our results demonstrate that AMSCs proliferate and eventually produce a collagen-rich extracellular matrix on porous PCLF scaffolds. This novel scaffold has potential in stem cell engineering and ligament regeneration.

Mineralization Induction of Gingival Fibroblasts and Construction of a Sandwich Tissue-Engineered Complex for Repairing Periodontal Defects

PubMed Central

Wu, Mingxuan; Zhang, Yanning; Liu, Huijuan; Dong, Fusheng

2018-01-01

Background The ideal healing technique for periodontal tissue defects would involve the functional regeneration of the alveolar bone, cementum, and periodontal ligament, with new periodontal attachment formation. In this study, gingival fibroblasts were induced and a “sandwich” tissue-engineered complex (a tissue-engineered periodontal membrane between 2 tissue-engineered mineralized membranes) was constructed to repair periodontal defects. We evaluated the effects of gingival fibroblasts used as seed cells on the repair of periodontal defects and periodontal regeneration. Material/Methods Primitively cultured gingival fibroblasts were seeded bilaterally on Bio-Gide collagen membrane (a tissue-engineered periodontal membrane) or unilaterally on small intestinal submucosa segments, and their mineralization was induced. A tissue-engineered sandwich was constructed, comprising the tissue-engineered periodontal membrane flanked by 2 mineralized membranes. Periodontal defects in premolar regions of Beagles were repaired using the tissue-engineered sandwich or periodontal membranes. Periodontal reconstruction was compared to normal and trauma controls 10 or 20 days postoperatively. Results Periodontal defects were completely repaired by the sandwich tissue-engineered complex, with intact new alveolar bone and cementum, and a new periodontal ligament, 10 days postoperatively. Conclusions The sandwich tissue-engineered complex can achieve ideal periodontal reconstruction rapidly. PMID:29470454

Anterior cruciate ligament- and hamstring tendon-derived cells: in vitro differential properties of cells involved in ACL reconstruction.

PubMed

Ghebes, Corina Adriana; Kelder, Cindy; Schot, Thomas; Renard, Auke J; Pakvis, Dean F M; Fernandes, Hugo; Saris, Daniel B

2017-04-01

Anterior cruciate ligament (ACL) reconstruction involves the replacement of the torn ligament with a new graft, often a hamstring tendon (HT). Described as similar, the ACL and HT have intrinsic differences related to their distinct anatomical locations. From a cellular perspective, identifying these differences represents a step forward in the search for new cues that enhance recovery after the reconstruction. The purpose of this study was to characterize the phenotype and multilineage potential of ACL- and HT-derived cells. ACL- and HT-derived cells were isolated from tissue harvest from patients undergoing total knee arthroplasty (TKA) or ACL reconstruction. In total, three ACL and three HT donors were investigated. Cell morphology, self-renewal potential (CFU-F), surface marker profiling, expression of tendon/ligament-related markers (PCR) and multilineage potential were analysed for both cell types; both had fibroblast-like morphology and low self-renewal potential. No differences in the expression of tendon/ligament-related genes or a selected set of surface markers were observed between the two cell types. However, differences in their multilineage potential were observed: while ACL-derived cells showed a high potential to differentiate into chondrocytes and adipocytes, but not osteoblasts, HT-derived cells showed poor potential to form adipocytes, chondrocytes and osteoblasts. Our results demonstrated that HT-derived cells have low multilineage potential compared to ACL-derived cells, further highlighting the need for extrinsic signals to fully restore the function of the ACL upon reconstruction. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Pentadecapeptide BPC 157 enhances the growth hormone receptor expression in tendon fibroblasts.

PubMed

Chang, Chung-Hsun; Tsai, Wen-Chung; Hsu, Ya-Hui; Pang, Jong-Hwei Su

2014-11-19

BPC 157, a pentadecapeptide derived from human gastric juice, has been demonstrated to promote the healing of different tissues, including skin, muscle, bone, ligament and tendon in many animal studies. However, the underlying mechanism has not been fully clarified. The present study aimed to explore the effect of BPC 157 on tendon fibroblasts isolated from Achilles tendon of male Sprague-Dawley rat. From the result of cDNA microarray analysis, growth hormone receptor was revealed as one of the most abundantly up-regulated genes in tendon fibroblasts by BPC 157. BPC 157 dose- and time-dependently increased the expression of growth hormone receptor in tendon fibroblasts at both the mRNA and protein levels as measured by RT/real-time PCR and Western blot, respectively. The addition of growth hormone to BPC 157-treated tendon fibroblasts dose- and time-dependently increased the cell proliferation as determined by MTT assay and PCNA expression by RT/real-time PCR. Janus kinase 2, the downstream signal pathway of growth hormone receptor, was activated time-dependently by stimulating the BPC 157-treated tendon fibroblasts with growth hormone. In conclusion, the BPC 157-induced increase of growth hormone receptor in tendon fibroblasts may potentiate the proliferation-promoting effect of growth hormone and contribute to the healing of tendon.

Ligament Tissue Engineering Using a Novel Porous Polycaprolactone Fumarate Scaffold and Adipose Tissue-Derived Mesenchymal Stem Cells Grown in Platelet Lysate

PubMed Central

Wagner, Eric R.; Bravo, Dalibel; Dadsetan, Mahrokh; Riester, Scott M.; Chase, Steven; Westendorf, Jennifer J.; Dietz, Allan B.; van Wijnen, Andre J.; Yaszemski, Michael J.

2015-01-01

Purpose: Surgical reconstruction of intra-articular ligament injuries is hampered by the poor regenerative potential of the tissue. We hypothesized that a novel composite polymer “neoligament” seeded with progenitor cells and growth factors would be effective in regenerating native ligamentous tissue. Methods: We synthesized a fumarate-derivative of polycaprolactone fumarate (PCLF) to create macro-porous scaffolds to allow cell–cell communication and nutrient flow. Clinical grade human adipose tissue-derived human mesenchymal stem cells (AMSCs) were cultured in 5% human platelet lysate (PL) and seeded on scaffolds using a dynamic bioreactor. Cell growth, viability, and differentiation were examined using metabolic assays and immunostaining for ligament-related markers (e.g., glycosaminoglycans [GAGs], alkaline phosphatase [ALP], collagens, and tenascin-C). Results: AMSCs seeded on three-dimensional (3D) PCLF scaffolds remain viable for at least 2 weeks with proliferating cells filling the pores. AMSC proliferation rates increased in PL compared to fetal bovine serum (FBS) (p < 0.05). Cells had a low baseline expression of ALP and GAG, but increased expression of total collagen when induced by the ligament and tenogenic growth factor fibroblast growth factor 2 (FGF-2), especially when cultured in the presence of PL (p < 0.01) instead of FBS (p < 0.05). FGF-2 and PL also significantly increased immunostaining of tenascin-C and collagen at 2 and 4 weeks compared with human fibroblasts. Summary: Our results demonstrate that AMSCs proliferate and eventually produce a collagen-rich extracellular matrix on porous PCLF scaffolds. This novel scaffold has potential in stem cell engineering and ligament regeneration. PMID:26413793

A Biofilm Pocket Model to Evaluate Different Non-Surgical Periodontal Treatment Modalities in Terms of Biofilm Removal and Reformation, Surface Alterations and Attachment of Periodontal Ligament Fibroblasts

PubMed Central

Hägi, Tobias T.; Klemensberger, Sabrina; Bereiter, Riccarda; Nietzsche, Sandor; Cosgarea, Raluca; Flury, Simon; Lussi, Adrian; Sculean, Anton; Eick, Sigrun

2015-01-01

Background and Aim There is a lack of suitable in vitro models to evaluate various treatment modalities intending to remove subgingival bacterial biofilm. Consequently, the aims of this in vitro-study were: a) to establish a pocket model enabling mechanical removal of biofilm and b) to evaluate repeated non-surgical periodontal treatment with respect to biofilm removal and reformation, surface alterations, tooth hard-substance-loss, and attachment of periodontal ligament (PDL) fibroblasts. Material and Methods Standardized human dentin specimens were colonized by multi-species biofilms for 3.5 days and subsequently placed into artificially created pockets. Non-surgical periodontal treatment was performed as follows: a) hand-instrumentation with curettes (CUR), b) ultrasonication (US), c) subgingival air-polishing using erythritol (EAP) and d) subgingival air-polishing using erythritol combined with chlorhexidine digluconate (EAP-CHX). The reduction and recolonization of bacterial counts, surface roughness (Ra and Rz), the caused tooth substance-loss (thickness) as well as the attachment of PDL fibroblasts were evaluated and statistically analyzed by means of ANOVA with Post-Hoc LSD. Results After 5 treatments, bacterial reduction in biofilms was highest when applying EAP-CHX (4 log10). The lowest reduction was found after CUR (2 log10). Additionally, substance-loss was the highest when using CUR (128±40 µm) in comparison with US (14±12 µm), EAP (6±7 µm) and EAP-CHX (11±10) µm). Surface was roughened when using CUR and US. Surfaces exposed to US and to EAP attracted the highest numbers of PDL fibroblasts. Conclusion The established biofilm model simulating a periodontal pocket combined with interchangeable placements of test specimens with multi-species biofilms enables the evaluation of different non-surgical treatment modalities on biofilm removal and surface alterations. Compared to hand instrumentation the application of ultrasonication and of air-polishing with erythritol prevents from substance-loss and results in a smooth surface with nearly no residual biofilm that promotes the reattachment of PDL fibroblasts. PMID:26121365

A Biofilm Pocket Model to Evaluate Different Non-Surgical Periodontal Treatment Modalities in Terms of Biofilm Removal and Reformation, Surface Alterations and Attachment of Periodontal Ligament Fibroblasts.

PubMed

Hägi, Tobias T; Klemensberger, Sabrina; Bereiter, Riccarda; Nietzsche, Sandor; Cosgarea, Raluca; Flury, Simon; Lussi, Adrian; Sculean, Anton; Eick, Sigrun

2015-01-01

There is a lack of suitable in vitro models to evaluate various treatment modalities intending to remove subgingival bacterial biofilm. Consequently, the aims of this in vitro-study were: a) to establish a pocket model enabling mechanical removal of biofilm and b) to evaluate repeated non-surgical periodontal treatment with respect to biofilm removal and reformation, surface alterations, tooth hard-substance-loss, and attachment of periodontal ligament (PDL) fibroblasts. Standardized human dentin specimens were colonized by multi-species biofilms for 3.5 days and subsequently placed into artificially created pockets. Non-surgical periodontal treatment was performed as follows: a) hand-instrumentation with curettes (CUR), b) ultrasonication (US), c) subgingival air-polishing using erythritol (EAP) and d) subgingival air-polishing using erythritol combined with chlorhexidine digluconate (EAP-CHX). The reduction and recolonization of bacterial counts, surface roughness (Ra and Rz), the caused tooth substance-loss (thickness) as well as the attachment of PDL fibroblasts were evaluated and statistically analyzed by means of ANOVA with Post-Hoc LSD. After 5 treatments, bacterial reduction in biofilms was highest when applying EAP-CHX (4 log10). The lowest reduction was found after CUR (2 log10). Additionally, substance-loss was the highest when using CUR (128±40 µm) in comparison with US (14±12 µm), EAP (6±7 µm) and EAP-CHX (11±10) µm). Surface was roughened when using CUR and US. Surfaces exposed to US and to EAP attracted the highest numbers of PDL fibroblasts. The established biofilm model simulating a periodontal pocket combined with interchangeable placements of test specimens with multi-species biofilms enables the evaluation of different non-surgical treatment modalities on biofilm removal and surface alterations. Compared to hand instrumentation the application of ultrasonication and of air-polishing with erythritol prevents from substance-loss and results in a smooth surface with nearly no residual biofilm that promotes the reattachment of PDL fibroblasts.

In vitro evaluation of surface roughness, adhesion of periodontal ligament fibroblasts, and Streptococcus gordonii following root instrumentation with Gracey curettes and subsequent polishing with diamond-coated curettes.

PubMed

Eick, Sigrun; Bender, Philip; Flury, Simon; Lussi, Adrian; Sculean, Anton

2013-03-01

The objective of the study was to evaluate the efficacy of an additional usage of a diamond-coated curette on surface roughness, adhesion of periodontal ligament (PDL) fibroblasts, and of Streptococcus gordonii in vitro. Test specimens were prepared from extracted teeth and exposed to instrumentation with conventional Gracey curettes with or without additional use of diamond-coated curettes. Surface roughness (Ra and Rz) was measured before and following treatment. In addition, the adhesion of PDL fibroblasts for 72 h and adhesion of S. gordonii ATCC 10558 for 2 h have been determined. Instrumentation with conventional Gracey curettes reduced surface roughness (median Ra before: 0.36 μm/after: 0.25 μm; p < 0.001; median Rz before: 2.34 μm/after: 1.61 μm; p < 0.001). The subsequent instrumentation with the diamond-coated curettes resulted in a median Ra of 0.31 μm/Rz of 2.06 μm (no significance in comparison to controls). The number of attached PDL fibroblasts did not change following scaling with Gracey curettes. The additional instrumentation with the diamond-coated curettes resulted in a two-fold increase in the number of attached PDL fibroblasts but not in the numbers of adhered bacteria. Treatment of root surfaces with conventional Gracey curettes followed by subsequent polishing with diamond-coated curettes may result in a root surface which provides favorable conditions for the attachment of PDL fibroblasts without enhancing microbial adhesion. The improved attachment of PDL fibroblasts and the limited microbial adhesion on root surfaces treated with scaling with conventional Gracey curettes followed by subsequent polishing with diamond-coated curettes may favor periodontal wound healing.

Curcumin targets fibroblast–tumor cell interactions in oral squamous cell carcinoma

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

Dudás, József, E-mail: jozsef.dudas@i-med.ac.at; Fullár, Alexandra, E-mail: fullarsz@gmail.com; 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Üllői út 26, 1085 Budapest

Co-culture of periodontal ligament fibroblasts (PDLs) and SCC-25 oral squamous carcinoma cells (OSCC) results in conversion of PDLs into carcinoma-associated fibroblasts (CAFs) and induces epithelial-to mesenchymal transition (EMT) of OSCC tumor cells. We hypothesized that Curcumin targets this dynamic mutual interaction between CAFs and tumor cells. Normal and 2 μM Curcumin-treated co-culture were performed for 4 days, followed by analysis of tumor cell invasivity, mRNA/protein expression of EMT-markers and mediators, activity measure of matrix metalloproteinase 9 (MMP-9), and western blot analysis of signal transduction in tumor cells and fibroblasts. In Curcumin-treated co-culture, in tumor cells, the levels of nuclear factormore » κB (NFκBα) and early response kinase (ERK)—decreased, in fibroblasts, integrin αv protein synthesis decreased compared to corresponding cells in normal co-culture. The signal modulatory changes induced by Curcumin caused decreased release of EMT-mediators in CAFs and reversal of EMT in tumor cells, which was associated with decreased invasion. These data confirm the palliative potential of Curcumin in clinical application. - Graphical abstract: Co-culture of periodontal ligament fibroblasts (PDLs) and SCC-25 oral squamous carcinoma cells (OSCC) results in conversion of PDLs into carcinoma-associated fibroblasts (CAFs) and induces epithelial-to mesenchymal transition (EMT) of tumor cells. Curcumin targets this dynamic mutual interaction between CAFs and tumor cells by inhibiting the production of EMT mediators in CAFs and by modification of intracellular signaling in tumor cells. This causes less invasivity and reversal of EMT in tumor cells. Highlights: ► Curcumin targets tumor–fibroblast interaction in head and neck cancer. ► Curcumin suppresses mediators of epithelial–mesenchymal transition. ► Curcumin decreases the invasivity of tumor cells.« less

The role of mechanical loading in ligament tissue engineering.

PubMed

Benhardt, Hugh A; Cosgriff-Hernandez, Elizabeth M

2009-12-01

Tissue-engineered ligaments have received growing interest as a promising alternative for ligament reconstruction when traditional transplants are unavailable or fail. Mechanical stimulation was recently identified as a critical component in engineering load-bearing tissues. It is well established that living tissue responds to altered loads through endogenous changes in cellular behavior, tissue organization, and bulk mechanical properties. Without the appropriate biomechanical cues, new tissue formation lacks the necessary collagenous organization and alignment for sufficient load-bearing capacity. Therefore, tissue engineers utilize mechanical conditioning to guide tissue remodeling and improve the performance of ligament grafts. This review provides a comparative analysis of the response of ligament and tendon fibroblasts to mechanical loading in current bioreactor studies. The differential effect of mechanical stimulation on cellular processes such as protease production, matrix protein synthesis, and cell proliferation is examined in the context of tissue engineering design.

Effects of chitosan-coated fibers as a scaffold for three-dimensional cultures of rabbit fibroblasts for ligament tissue engineering.

PubMed

Sarukawa, Junichiro; Takahashi, Masaaki; Abe, Masashi; Suzuki, Daisuke; Tokura, Seiichi; Furuike, Tetsuya; Tamura, Hiroshi

2011-01-01

Material selection in tissue-engineering scaffolds is one of the primary factors defining cellular response and matrix formation. In this study, we fabricated chitosan-coated poly(lactic acid) (PLA) fiber scaffolds to test our hypothesis that PLA fibers coated with chitosan highly promoted cell supporting properties compared to those without chitosan. Both PLA fibers (PLA group) and chitosan-coated PLA fibers (PLA-chitosan group) were fabricated for this study. Anterior cruciate ligament (ACL) fibroblasts were isolated from Japanese white rabbits and cultured on scaffolds consisting of each type of fiber. The effects of cell adhesivity, proliferation, and synthesis of the extracellular matrix (ECM) for each fiber were analyzed by cell counting, hydroxyproline assay, scanning electron microscopy and quantitative RT-PCR. Cell adhesivity, proliferation, hydroxyproline content and the expression of type-I collagen mRNA were significantly higher in the PLA-chitosan group than in the PLA group. Scanning electron microscopic observation showed that fibroblasts proliferated with a high level of ECM synthesis around the cells. Chitosan coating improved ACL fibroblast adhesion and proliferation, and had a positive effect on matrix production. Thus, the advantages of chitosan-coated PLA fibers show them to be a suitable biomaterial for ACL tissue-engineering scaffolds.

Design and characterization of a biodegradable composite scaffold for ligament tissue engineering.

PubMed

Hayami, James W S; Surrao, Denver C; Waldman, Stephen D; Amsden, Brian G

2010-03-15

Herein we report on the development and characterization of a biodegradable composite scaffold for ligament tissue engineering based on the fundamental morphological features of the native ligament. An aligned fibrous component was used to mimic the fibrous collagen network and a hydrogel component to mimic the proteoglycan-water matrix of the ligament. The composite scaffold was constructed from cell-adherent, base-etched, electrospun poly(epsilon-caprolactone-co-D,L-lactide) (PCLDLLA) fibers embedded in a noncell-adherent photocrosslinked N-methacrylated glycol chitosan (MGC) hydrogel seeded with primary ligament fibroblasts. Base etching improved cellular adhesion to the PCLDLLA material. Cells within the MGC hydrogel remained viable (72 +/- 4%) during the 4-week culture period. Immunohistochemistry staining revealed ligament ECM markers collagen type I, collagen type III, and decorin organizing and accumulating along the PCLDLLA fibers within the composite scaffolds. On the basis of these results, it was determined that the composite scaffold design was a viable alternative to the current approaches used for ligament tissue engineering and merits further study. (c) 2009 Wiley Periodicals, Inc.

Cell-based and biomaterial approaches to connective tissue repair

NASA Astrophysics Data System (ADS)

Stalling, Simone Suzette

Connective tissue injuries of skin, tendon and ligament, heal by a reparative process in adults, filling the wound site with fibrotic, disorganized scar tissue that poorly reflects normal tissue architecture or function. Conversely, fetal skin and tendon have been shown to heal scarlessly. Complete regeneration is not intrinsically ubiquitous to all fetal tissues; fetal diaphragmatic and gastrointestinal injuries form scars. In vivo studies suggest that the presence of fetal fibroblasts is essential for scarless healing. In the orthopaedic setting, adult anterior cruciate ligament (ACL) heals poorly; however, little is known about the regenerative capacity of fetal ACL or fetal ACL fibroblasts. We characterized in vitro wound healing properties of fetal and adult ACL fibroblasts demonstrating that fetal ACL fibroblasts migrate faster and elaborate greater quantities of type I collagen, suggesting the healing potential of the fetal ACL may not be intrinsically poor. Similar to fetal ACL fibroblasts, fetal dermal fibroblasts also exhibit robust cellular properties. We investigated the age-dependent effects of dermal fibroblasts on tendon-to-bone healing in rat supraspinatus tendon injuries, a reparative injury model. We hypothesized delivery of fetal dermal fibroblasts would increase tissue organization and mechanical properties in comparison to adult dermal fibroblasts. However, at 1 and 8 weeks, the presence of dermal fibroblasts, either adult or fetal, had no significant effect on tissue histology or mechanical properties. There was a decreasing trend in cross-sectional area of repaired tendons treated with fetal dermal fibroblasts in comparison to adult, but this finding was not significant in comparison to controls. Finally, we synthesized a novel polysaccharide, methacrylated methylcellulose (MA-MC), and fabricated hydrogels using a well-established photopolymerization technique. We characterized the physical and mechanical properties of MA-MC hydrogels in vitro as well as in a subcutaneous mouse model. Stable MA-MC hydrogels, of varying weight percentages, demonstrated tunable swelling and mechanical properties in the absence of cytotoxic degradation products. In vivo, 6wt% MA-MC hydrogels maintained their shape and mechanical integrity while eliciting a minimal inflammatory response; highly desirable properties for soft tissue reconstruction. These cellulose-based photopolymerizable hydrogels can be further optimized for drug delivery and tissue engineering applications to enhance wound repair.

Combined use of bFGF and GDF-5 enhances the healing of medial collateral ligament injury

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

Saiga, Kenta; Furumatsu, Takayuki, E-mail: matino@md.okayama-u.ac.jp; Yoshida, Aki

Research highlights: {yields} bFGF/GDF-5 treatment increases cellular proliferation and migration of MCL fibroblasts. {yields} bFGF/GDF-5 hydrogels stimulate the healing of MCL injury in vivo. {yields} bFGF/GDF-5 hydrogels stimulate Col1a1 expression and type I collagen synthesis. {yields} Combined use of bFGF/GDF-5 enhances MCL healing. -- Abstract: Basic fibroblast growth factor (bFGF) and growth and differentiation factor (GDF)-5 stimulate the healing of medial collateral ligament (MCL) injury. However, the effect of isolated and combined use of bFGF/GDF-5 remains still unclear. We investigated cellular proliferation and migration responding to bFGF/GDF-5 using rabbit MCL fibroblasts. Rabbit MCL injury was treated by bFGF and/or GDF-5more » with peptide hydrogels. Gene expression and deposition of collagens in healing tissues were evaluated. bFGF/GDF-5 treatment additively enhanced cell proliferation and migration. bFGF/GDF-5 hydrogels stimulated Col1a1 expression without increasing Col3a1 expression. Combined use of bFGF/GDF-5 stimulated type I collagen deposition and the reorganization of fiber alignment, and induced better morphology of fibroblasts in healing MCLs. Our study indicates that combined use of bFGF/GDF-5 might enhance MCL healing by increasing proliferation and migration of MCL fibroblasts, and by regulating collagen synthesis and connective fiber alignment.« less

Comparison of potentials between stem cells isolated from human anterior cruciate ligament and bone marrow for ligament tissue engineering.

PubMed

Cheng, Ming-Te; Liu, Chien-Lin; Chen, Tain-Hsiung; Lee, Oscar K

2010-07-01

We have previously isolated and identified stem cells from human anterior cruciate ligament (ACL). The purpose of this study was to evaluate the differences in proliferation, differentiation, and extracellular matrix (ECM) formation abilities between bone marrow stem cells (BMSCs) and ACL-derived stem cells (LSCs) from the same donors when cultured with different growth factors, including basic fibroblast growth factor (bFGF), epidermal growth factor, and transforming growth factor-beta 1 (TGF-beta1). Ligament tissues and bone marrow aspirate were obtained from patients undergoing total knee arthroplasty and ACL reconstruction surgeries. Proliferation, colony formation, and population doubling capacity as well as multilineage differentiation potentials of LSCs and BMSCs were compared. Gene expression and ECM production for ligament engineering were also evaluated. It was found that BMSCs possessed better osteogenic differentiation potential than LSCs, while similar adipogenic and chondrogenic differentiation abilities were observed. Proliferation rates of both LSCs and BMSCs were enhanced by bFGF and TGF-beta1. TGF-beta1 treatment significantly increased the expression of type I collagen, type III collagen, fibronectin, and alpha-smooth muscle actin in LSCs, but TGF-beta1 only upregulated type I collagen and tenascin-c in BMSCs. Protein quantification further confirmed the results of differential gene expression and suggested that LSCs and BMSCs increase ECM production upon TGF-beta1 treatment. In summary, in comparison with BMSCs, LSCs proliferate faster and maintain an undifferentiated state with bFGF treatment, whereas under TGF-beta1 treatment, LSCs upregulate major tendinous gene expression and produce a robust amount of ligament ECM protein, making LSCs a potential cell source in future applications of ACL tissue engineering.

Human periodontal ligament fibroblasts synthesize C-reactive protein and Th-related cytokines in response to interleukin (IL)-6 trans-signalling.

PubMed

Hernández-Caldera, A; Vernal, R; Paredes, R; Veloso-Matta, P; Astorga, J; Hernández, M

2018-06-01

To characterize the potential of human periodontal ligament fibroblasts (HPLF) to synthesize CRP and Th-related cytokines in response to IL-6 in periodontal health and apical inflammation. Primary HPLF stimulated with IL-6, soluble(s) IL-6 receptor (R) and controls were assayed for CRP, Th1, Th2, Th17 and Treg-related cytokines by quantitative real-time PCR and ELISA, respectively. IL-6R mRNA expression and its soluble protein levels were screened in HPLF cultures, and ex vivo samples of healthy periodontal ligaments (n = 5) and apical lesions (n = 13). Data were analysed with ANOVA or unpaired t-test. 0.5 ng mL -1 IL-6 plus 1 ng mL -1 of its soluble receptor (sIL-6R) for 24 h was effective in inducing CRP production. IL-6 alone had a mild dose-dependent effect; co-stimulation with sIL-6R significantly enhanced this effect, whereas it was completely abolished by the addition of IL-6R blocking antibody (P < 0.05). Similarly, higher mRNA expression and protein levels of Th1, Th17 and partially Treg-related cytokines were found for IL-6 combined with its soluble receptor versus the nonstimulated group and IL-6R antibody (P < 0.05). IL-6R mRNA expression was slightly induced by IL-6 compared to THP-1 cells, but sILR-6 protein could not be detected in HPLF. High sIL-6R levels were detected in apical lesions and were immunolocalized to mononuclear inflammatory cells and proliferating epithelium. IL-6 trans-signalling induced Th1 and Th17-related cytokines and represents an extra-hepatic mechanism for PCR synthesis in human periodontal ligament fibroblasts, contributing to explain the bone-destructive phenotype of apical lesions and eventually its systemic complications. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Cigarette smoke extract induces select matrix metalloproteinases and integrin expression in periodontal ligament fibroblasts.

PubMed

Bulmanski, Zachary; Brady, Matthew; Stoute, Diana; Lallier, Thomas E

2012-06-01

The periodontal ligament (PDL) is the connective tissue that anchors the cementum of the teeth to the alveolar bone. PDL fibroblasts are responsible for the production of collagen and remodeling of the PDL. Periodontal disease is increased among smokers in both incidence and severity. This study examines the direct effect of smoking on PDL fibroblasts and their production of various matrix components and remodeling enzymes. PDL cells were plated for 1 day and then treated with various concentrations of cigarette smoke extract (CSE). Survival of PDL cells was quantified after exposure to CSE, and their ability to contract three-dimensional collagen gels was examined. Changes in transcript expression after CSE treatment was compared using reverse transcription-polymerase chain reaction analysis for matrix metalloproteinases (MMPs), collagens, and integrins. Treatment with CSE-induced cell death at concentrations of ≥5%. PDL-cell-induced collagen gel contraction was reduced at concentrations of 1.5% CSE. Treatment with CSE selectively increased the expression of collagen Vα3 and decreased collagen XIα1. CSE increased the expression of MMP1 and MMP3 and, to a lesser extent, MMP2 and MMP8. CSE also increased the expression of integrins α1, α2, and α10 (collagen receptors) and α9 (a tenascin receptor). This study shows that cigarette smoking has local effects on the cells of the PDL. CSE reduced survival of PDL cells and their ability to contract collagen matrices. CSE also altered the expression of molecules known to provide the structural integrity of the ligament by altering collagen synthesis and remodeling as well as cell adhesion.

PLA-poloxamer/poloxamine copolymers for ligament tissue engineering: sound macromolecular design for degradable scaffolds and MSC differentiation.

PubMed

Leroy, Adrien; Nottelet, Benjamin; Bony, Claire; Pinese, Coline; Charlot, Benoît; Garric, Xavier; Noël, Danièle; Coudane, Jean

2015-04-01

The treatment of anterior cruciate ligament (ACL) failures remains a current clinical challenge. The present study aims at providing suitable degradable scaffolds for ligament tissue engineering. First, we focus on the design and the evaluation of poly(lactide)/poloxamer or poly(lactide)/poloxamine multiblock copolymers selected and developed to have suitable degradation and mechanical properties to match ACL repair. In the second part, it is shown that the copolymers can be processed in the form of microfibers and scaffolds consisting of a combination of twisted/braided fibers to further modulate the mechanical properties and prepare scaffold prototypes suitable for ligament application. Finally, after assessment of their cytocompatibility, the polymer scaffolds are associated with mesenchymal stem cells (MSCs). MSC differentiation toward a ligament fibroblast phenotype is promoted by a dual stimulation including an inductive culture medium and cyclic mechanical loads. RT-qPCR analyses confirm the potential of our scaffolds and MSCs for ACL regeneration with upregulation of some differentiation markers including Scleraxis, Tenascin-C and Tenomodulin.

Periodontal healing by periodontal ligament cell sheets in a teeth replantation model.

PubMed

Zhou, Yefang; Li, Yusheng; Mao, Ling; Peng, Hao

2012-02-01

Successful transplantation of avulsed teeth is to restore the attachment and regenerate the periodontal support. Different strategies have been applied in treatment from modification of teeth storage, antibiotic usage to peridontium tissue replacement. We developed a novel periodontal ligament cell-sheet delivery system to apply on delayed replanted teeth in promoting periodontal healing in a canine model. Autologous periodontal ligament (PDL) fibroblasts were isolated from extracted premolars of beagle dog. The cell-sheets were fabricated using normal culture dish after stimulation of extracellular matrix formation. Teeth were surgically extracted and attached soft tissues were removed. After root canal treatment, the root of teeth were wrapped by the PDL cell-sheets and replanted back to prior socket accordingly whilst teeth without cell sheets as a control. Eight weeks after surgery, the animals were sacrificed and decalcified specimens were prepared. Regeneration of periodontal tissue was evaluated through histology assay. Multi-layered PDL cell-sheet could be attached on tooth root and most cells on sheet-tooth constructs were viable before replantation. Minimum clinical signs of inflammation were observed in experiment. PDL cell-sheets group show significant higher occurrence of favourable healing (88.4%) than control group with low healing (5.3%). Periodontal ligament and cememtum tissue regeneration was observed in the experimental group, and the regenerated tissues showed high collagen type III, type I and fibronectin expression. The periodontal ligament cell-sheets fabricated through normal cell culture dish has a potential for regeneration of periodontal ligament and may become a novel therapy for avulsed teeth replantation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Biological effects of a semiconductor diode laser on human periodontal ligament fibroblasts

PubMed Central

Choi, Eun-Jeong; Yim, Ju-Young; Koo, Ki-Tae; Seol, Yang-Jo; Lee, Yong-Moo; Ku, Young; Rhyu, In-Chul; Chung, Chong-Pyoung

2010-01-01

Purpose It has been reported that low-level semiconductor diode lasers could enhance the wound healing process. The periodontal ligament is crucial for maintaining the tooth and surrounding tissues in periodontal wound healing. While low-level semiconductor diode lasers have been used in low-level laser therapy, there have been few reports on their effects on periodontal ligament fibroblasts (PDLFs). We performed this study to investigate the biological effects of semiconductor diode lasers on human PDLFs. Methods Human PDLFs were cultured and irradiated with a gallium-aluminum-arsenate (GaAlAs) semiconductor diode laser of which the wavelength was 810 nm. The power output was fixed at 500 mW in the continuous wave mode with various energy fluencies, which were 1.97, 3.94, and 5.91 J/cm2. A culture of PDLFs without laser irradiation was regarded as a control. Then, cells were additionally incubated in 72 hours for MTS assay and an alkaline phosphatase (ALPase) activity test. At 48 hours post-laser irradiation, western blot analysis was performed to determine extracellular signal-regulated kinase (ERK) activity. ANOVA was used to assess the significance level of the differences among groups (P<0.05). Results At all energy fluencies of laser irradiation, PDLFs proliferation gradually increased for 72 hours without any significant differences compared with the control over the entire period taken together. However, an increment of cell proliferation significantly greater than in the control occurred between 24 and 48 hours at laser irradiation settings of 1.97 and 3.94 J/cm2 (P<0.05). The highest ALPase activity was found at 48 and 72 hours post-laser irradiation with 3.94 J/cm2 energy fluency (P<0.05). The phosphorylated ERK level was more prominent at 3.94 J/cm2 energy fluency than in the control. Conclusions The present study demonstrated that the GaAlAs semiconductor diode laser promoted proliferation and differentiation of human PDLFs. PMID:20607054

Knee Ligament Injury and the Clinical Application of Tissue Engineering Techniques: A Systematic Review.

PubMed

Riley, Thomas C; Mafi, Reza; Mafi, Pouya; Khan, Wasim S

2018-02-23

The incidence of knee ligament injury is increasing and represents a significant cost to healthcare providers. Current interventions include tissue grafts, suture repair and non-surgical management. These techniques have demonstrated good patient outcomes but have been associated graft rejection, infection, long term immobilization and reduced joint function. The limitations of traditional management strategies have prompted research into tissue engineering of knee ligaments. This paper aims to evaluate whether tissue engineering of knee ligaments offers a viable alternative in the clinical management of knee ligament injuries. A search of existing literature was performed using OVID Medline, Embase, AMED, PubMed and Google Scholar, and a manual review of citations identified within these papers. Silk, polymer and extracellular matrix based scaffolds can all improve graft healing and collagen production. Fibroblasts and stem cells demonstrate compatibility with scaffolds, and have been shown to increase organized collagen production. These effects can be augmented using growth factors and extracellular matrix derivatives. Animal studies have shown tissue engineered ligaments can provide the biomechanical characteristics required for effective treatment of knee ligament injuries. There is a growing clinical demand for a tissue engineered alternative to traditional management strategies. Currently, there is limited consensus regarding material selection for use in tissue engineered ligaments. Further research is required to optimize tissue engineered ligament production before clinical application. Controlled clinical trials comparing the use of tissue engineered ligaments and traditional management in patients with knee ligament injury could determine whether they can provide a cost-effective alternative. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Oxidative stress induced by Porphyromonas gingivalis lysate and nicotine in human periodontal ligament fibroblasts.

PubMed

Nguyen, Thuy Thu; Huynh, Nam Nhat-Cong; Seubbuk, Sujiwan; Nilmoje, Thanapoj; Wanasuntronwong, Aree; Surarit, Rudee

2018-06-29

Porphyromonas gingivalis (P. gingivalis) and nicotine have been implicated as a major pathogen in the development and progression of periodontitis. One of the possible mechanism is via the oxidative stress of human periodontal ligament fibroblasts (PDLF) which lead to the damage of cell viability and function. This study aimed to investigate oxidative stress (OS) levels in the cultured media of human PDLF under the induction of P. gingivalis lysate and nicotine. Primary PDLF was cultured in growth media under P. gingivalis or/and nicotine treatment in different concentrations for 2 and 24 h. Following incubation, oxidative stress molecules malondialdehyde (MDA) and oxidized guanine species (Ox-GS) from the cell cultured supernatant were determined by spectrophotometric assay and ELISA, respectively. DCFDA and superoxide assays were performed to verify the production of ROS and intracellular superoxide radical under various stimuli. As a result, at both 2 and 24 h, Ox-GS and MDA levels in the medium of cells treated with different concentrations of P. gingivalis lysate and nicotine, either separately or in combination, were significantly different from the negative controls in a dose- and time-dependent manner. Interestingly, except MDA levels in P. gingivalis lysate at 20 µg/ml, MDA levels in all other tested conditions were found as same as one in the positive controls after 24 h. ROS and superoxide production were enhanced under P. gingivalis and/or nicotine stimulation. Therefore, OS biomarkers were generated by PDLF upon treatment with periodontal pathogens and nicotine which could elucidate a potential local mechanism of periodontal disease etiology via superoxide mediation.

Regeneration of the anterior cruciate ligament: Current strategies in tissue engineering

PubMed Central

Nau, Thomas; Teuschl, Andreas

2015-01-01

Recent advancements in the field of musculoskeletal tissue engineering have raised an increasing interest in the regeneration of the anterior cruciate ligament (ACL). It is the aim of this article to review the current research efforts and highlight promising tissue engineering strategies. The four main components of tissue engineering also apply in several ACL regeneration research efforts. Scaffolds from biological materials, biodegradable polymers and composite materials are used. The main cell sources are mesenchymal stem cells and ACL fibroblasts. In addition, growth factors and mechanical stimuli are applied. So far, the regenerated ACL constructs have been tested in a few animal studies and the results are encouraging. The different strategies, from in vitro ACL regeneration in bioreactor systems to bio-enhanced repair and regeneration, are under constant development. We expect considerable progress in the near future that will result in a realistic option for ACL surgery soon. PMID:25621217

Dielectrophoretic spectra of single cells determined by feedback-controlled levitation.

PubMed Central

Kaler, K V; Jones, T B

1990-01-01

In this paper we have utilized the principle of dielectrophoresis (DEP) to develop an apparatus to stably levitate single biological cells using a digital feedback control scheme. Using this apparatus, the positive DEP spectra of both Canola plant protoplast and ligament fibroblast cells have been measured over a wide range of frequencies (1 kHz to 50 MHz) and suspending medium conductivities (11-800 muS/cm). The experimental data thus obtained have been interpreted in terms of a simple spherical cell model. Furthermore, utilizing such a model, we have shown that various cellular parameters of interest can be readily obtained from the measured DEP levitation spectrum. Specifically, the effective membrane capacitance of single cells has been determined. Values of 0.47 +/- 0.03 muF/cm2 for Canola protoplasts and 1.52 +/- 0.26 muF/cm2 for ligament fibroblasts thus obtained are consistent with those determined by other existing electrical methods. Images FIGURE A1 PMID:2317544

Investigation of the Cell Surface Proteome of Human Periodontal Ligament Stem Cells

PubMed Central

Xiong, Jimin; Menicanin, Danijela; Marino, Victor

2016-01-01

The present study examined the cell surface proteome of human periodontal ligament stem cells (PDLSC) compared to human fibroblasts. Cell surface proteins were prelabelled with CyDye before processing to extract the membrane lysates, which were separated using 2D electrophoresis. Selected differentially expressed protein “spots” were identified using Mass spectrometry. Four proteins were selected for validation: CD73, CD90, Annexin A2, and sphingosine kinase 1 previously associated with mesenchymal stem cells. Flow cytometric analysis found that CD73 and CD90 were highly expressed by human PDLSC and gingival fibroblasts but not by keratinocytes, indicating that these antigens could be used as potential markers for distinguishing between mesenchymal cells and epithelial cell populations. Annexin A2 was also found to be expressed at low copy number on the cell surface of human PDLSC and gingival fibroblasts, while human keratinocytes lacked any cell surface expression of Annexin A2. In contrast, sphingosine kinase 1 expression was detected in all the cell types examined using immunocytochemical analysis. These proteomic studies form the foundation to further define the cell surface protein expression profile of PDLSC in order to better characterise this cell population and help develop novel strategies for the purification of this stem cell population. PMID:27579043

Investigation of the Cell Surface Proteome of Human Periodontal Ligament Stem Cells.

PubMed

Xiong, Jimin; Menicanin, Danijela; Zilm, Peter S; Marino, Victor; Bartold, P Mark; Gronthos, Stan

2016-01-01

The present study examined the cell surface proteome of human periodontal ligament stem cells (PDLSC) compared to human fibroblasts. Cell surface proteins were prelabelled with CyDye before processing to extract the membrane lysates, which were separated using 2D electrophoresis. Selected differentially expressed protein "spots" were identified using Mass spectrometry. Four proteins were selected for validation: CD73, CD90, Annexin A2, and sphingosine kinase 1 previously associated with mesenchymal stem cells. Flow cytometric analysis found that CD73 and CD90 were highly expressed by human PDLSC and gingival fibroblasts but not by keratinocytes, indicating that these antigens could be used as potential markers for distinguishing between mesenchymal cells and epithelial cell populations. Annexin A2 was also found to be expressed at low copy number on the cell surface of human PDLSC and gingival fibroblasts, while human keratinocytes lacked any cell surface expression of Annexin A2. In contrast, sphingosine kinase 1 expression was detected in all the cell types examined using immunocytochemical analysis. These proteomic studies form the foundation to further define the cell surface protein expression profile of PDLSC in order to better characterise this cell population and help develop novel strategies for the purification of this stem cell population.

Local application of periodontal ligament stromal cells promotes soft tissue regeneration.

PubMed

Baik, H S; Park, J; Lee, K J; Chung, C

2014-09-01

To test the potential stimulatory effect of local application of periodontal ligament (PDL) stromal cells on soft tissue regeneration. Fluorescently labeled PDL cells outgrown from extracted human premolars or phosphate-buffered saline were locally injected to the cutaneous wounds created on mice. Soft tissue regeneration was evaluated for 14 days using photographs and histomorphometry. PDL cell engraftment was tracked with confocal microscopy. To detect the paracrine effect of the PDL cells on soft tissue regeneration, PDL cell-conditioned medium (CM) was evaluated for the concentration of secretory factors, transforming growth factor-beta 1 (TGFβ1). The effect of PDL CM on the proliferation and migration of dermal fibroblast and keratinocyte was tested using MTT assay and migration assay. The application of PDL cells significantly promoted soft tissue regeneration compared with the application of PBS. Self-replicating PDL cells were engrafted into the hair follicles of the host tissue. Dermal fibroblast proliferation and keratinocyte migration were significantly enhanced by the treatment with PDL CM. Physiologically significant amount of TGFβ1 was secreted from PDL cells into the CM. Local injection of PDL cells promoted soft tissue regeneration in part by the enhancement of fibroblast proliferation and keratinocyte migration through a paracrine mechanism. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

In vitro comparison of human fibroblasts from intact and ruptured ACL for use in tissue engineering.

PubMed

Brune, T; Borel, A; Gilbert, T W; Franceschi, J P; Badylak, S F; Sommer, P

2007-12-17

The present study compares fibroblasts extracted from intact and ruptured human anterior cruciate ligaments (ACL) for creation of a tissue engineered ACL-construct, made of porcine small intestinal submucosal extracellular matrix (SIS-ECM) seeded with these ACL cells. The comparison is based on histological, immunohistochemical and RT-PCR analyses. Differences were observed between cells in a ruptured ACL (rACL) and cells in an intact ACL (iACL), particularly with regard to the expression of integrin subunits and smooth muscle actin (SMA). Despite these differences in the cell source, both cell populations behaved similarly when seeded on an SIS-ECM scaffold, with similar cell morphology, connective tissue organization and composition, SMA and integrin expression. This study shows the usefulness of naturally occurring scaffolds such as SIS-ECM for the study of cell behaviour in vitro, and illustrates the possibility to use autologous cells extracted from ruptured ACL biopsies as a source for tissue engineered ACL constructs.

In vitro study on silk fibroin textile structure for anterior cruciate ligament regeneration.

PubMed

Farè, Silvia; Torricelli, Paola; Giavaresi, Gianluca; Bertoldi, Serena; Alessandrino, Antonio; Villa, Tomaso; Fini, Milena; Tanzi, Maria Cristina; Freddi, Giuliano

2013-10-01

A novel hierarchical textile structure made of silk fibroin from Bombyx mori capable of matching the mechanical performance requirements of anterior cruciate ligament (ACL) and in vitro cell ingrowth is described. This sericin-free, Silk Fibroin Knitted Sheath with Braided Core (SF-KSBC) structure was fabricated using available textile technologies. Micro-CT analysis confirmed that the core was highly porous and had a higher degree of interconnectivity than that observed for the sheath. The in vivo cell colonization of the scaffolds is thus expected to penetrate even the internal parts of the structure. Tensile mechanical tests demonstrated a maximum load of 1212.4±56.4 N (under hydrated conditions), confirming the scaffold's suitability for ACL reconstruction. The absence of cytotoxic substances in the extracts of the SF-KSBC structure in culture medium was verified by in vitro tests with L929 fibroblasts. In terms of extracellular matrix production, Human Periodontal Ligament Fibroblasts (HPdLFs) cultured in direct contact with SF-KSBC, compared to control samples, demonstrated an increased secretion of aggrecan (PG) and fibronectin (FBN) at 3 and 7 days of culture, and no change in IL-6 and TNF-α secretion. Altogether, the outcomes of this investigation confirm the significant utility of this novel scaffold for ACL tissue regeneration. Copyright © 2013 Elsevier B.V. All rights reserved.

[EXPERIMENTAL RESEARCH OF DIFFERENTIATION OF HUMAN AMNIOTIC MESENCHYMAL STEM CELLS INTO LIGAMENT CELLS IN VITRO].

PubMed

Jin, Ying; Li, Yuwan; Zhang, Chenghao; Wu, Shuhong; Cheng, Daixiong; Liu, Yi

2016-02-01

To discuss whether human amniotic mesenchymal stem cells (hAMSCs) possesses the characteristic of mesenchymal stem cells, and could differentiate into ligament cells in vitro after induction. The hAMSCs were separated through enzyme digestion, and the phenotypic characteristics of hAMSCs were tested through flow cytometry. The cells at passage 3 were cultured with L-DMEM/F12 medium containing transforming growth factor beta1 (TGF-beta1) + basic fibroblast growth factor (bFGF) (group A), containing hyaluronic acid (HA) (group B), containing TGF-beta1+bFGF+HA (group C), and simple L-DMEM/F12 medium (group D) as control group. The morphology changes of cells in each group were observed by inverted phase contrast microscope at 21 days after induction; the cellular activities and proliferation were examined by sulforhodamine (SRB) colorimetric method; and specific mRNA and protein expressions of ligament including collagen type I, collagen type III, and tenascin C (TNC) were measured by real-time fluorescence quantitative PCR and immunohistochemical staining. The flow cytometry result indicated that hAMSCs expressed mesenchymal stem cell phenotype. After 21 days of induction, the cells in groups A, B, and C grew like spindle-shaped fibroblasts under inverted phase contrast microscope, and cells showed single shape, obvious directivity, and compact arrangement in group C. The SRB result indicated that the cells in each group reached the peak of growth curve at 6 days; the cellular activities of groups A, B, and C were significantly higher than that of group D at 6 days after induction. Also, the immunohistochemical staining results showed that no expressions of TNC were detected in 4 groups at 7 days; expressions of collagen type I in groups A, B, and C were significantly higher than that in group D at 7, 14, and 21 days (P<0.001); the expressions of collagen type III in groups A, B, and C were significantly higher than that in group D at 14 and 21 days (P<0.001). There was an increasing tendency with time in collagen type I of group B, in collagen type III and TNC of groups A and C, showing significant difference among different time points (P<0.001). The real-time fluorescence quantitative PCR results revealed that the mRNA expressions of collagen type I and TNC in group C were significantly higher than those in groups A and B (P<0.05), and the mRNA expression of collagen type III in group B were significantly higher than that in groups A and C at 21 days (P<0.05). The mRNA expressions of collagen type I and TNC in groups A and C and mRNA expression of collagen type III in group C had an increasing tendency with time, showing significant difference among different time points (P<0.001). The hAMSCs possesses the characteristics of mesenchymal stem cells and excellent proliferation capacity. After in vitro induction, the expressions of ligament specific genes can be up-regulated and the synthesis of ligament specific proteins can be also strengthened. As a result, it can be used as one of ligament tissue engineering seed cell sources.

In vitro characterization of self-assembled anterior cruciate ligament cell spheroids for ligament tissue engineering.

PubMed

Hoyer, M; Meier, C; Breier, A; Hahner, J; Heinrich, G; Drechsel, N; Meyer, M; Rentsch, C; Garbe, L-A; Ertel, W; Lohan, A; Schulze-Tanzil, G

2015-03-01

Tissue engineering of an anterior cruciate ligament (ACL) implant with functional enthesis requires site-directed seeding of different cell types on the same scaffold. Therefore, we studied the suitability of self-assembled three-dimensional spheroids generated by lapine ACL ligament fibroblasts for directed scaffold colonization. The spheroids were characterized in vitro during 14 days in static and 7 days in dynamic culture. Size maintenance of self-assembled spheroids, the vitality, the morphology and the expression pattern of the cells were monitored. Additionally, we analyzed the total sulfated glycosaminoglycan, collagen contents and the expression of the ligament components type I collagen, decorin and tenascin C on protein and for COL1A1, DCN and TNMD on gene level in the spheroids. Subsequently, the cell colonization of polylactide-co-caprolactone [P(LA-CL)] and polydioxanone (PDS) polymer scaffolds was assessed in response to a directed, spheroid-based seeding technique. ACL cells were able to self-assemble spheroids and survive over 14 days. The spheroids decreased in size but not in cellularity depending on the culture time and maintained or even increased their differentiation state. The area of P[LA-CL] scaffolds, colonized after 14 days by the cells of one spheroid, was in average 4.57 ± 2.3 mm(2). Scaffolds consisting of the polymer P[LA-CL] were more suitable for colonization by spheroids than PDS embroideries. We conclude that ACL cell spheroids are suitable as site-directed seeding strategy for scaffolds in ACL tissue engineering approaches and recommend the use of freshly assembled spheroids for scaffold colonization, due to their balanced proliferation and differentiation.

Exposure to transforming growth factor-β1 after basic fibroblast growth factor promotes the fibroblastic differentiation of human periodontal ligament stem/progenitor cell lines.

PubMed

Kono, Kiyomi; Maeda, Hidefumi; Fujii, Shinsuke; Tomokiyo, Atsushi; Yamamoto, Naohide; Wada, Naohisa; Monnouchi, Satoshi; Teramatsu, Yoko; Hamano, Sayuri; Koori, Katsuaki; Akamine, Akifumi

2013-05-01

Basic fibroblast growth factor (bFGF) is a cytokine that promotes the regeneration of the periodontium, the specialized tissues supporting the teeth. bFGF, does not, however, induce the synthesis of smooth muscle actin alpha 2 (ACTA2), type I collagen (COL1), or COL3, which are principal molecules in periodontal ligament (PDL) tissue, a component of the periodontium. We have suggested the feasibility of using transforming growth factor-β1 (TGFβ1) to induce fibroblastic differentiation of PDL stem/progenitor cells (PDLSCs). Here, we investigated the effect of the subsequent application of TGFβ1 after bFGF (bFGF/TGFβ1) on the differentiation of PDLSCs into fibroblastic cells. We first confirmed the expression of bFGF and TGFβ1 in rat PDL tissue and primary human PDL cells. Receptors for both bFGF and TGFβ1 were expressed in the human PDLSC lines 1-11 and 1-17. Exposure to bFGF for 2 days promoted vascular endothelial growth factor gene and protein expression in both cell lines and down-regulated the expression of ACTA2, COL1, and COL3 mRNA in both cell lines and the gene fibrillin 1 (FBN1) in cell line 1-11 alone. Furthermore, bFGF stimulated cell proliferation of these cell lines and significantly increased the number of cells in phase G2/M in the cell lines. Exposure to TGFβ1 for 2 days induced gene expression of ACTA2 and COL1 in both cell lines and FBN1 in cell line 1-11 alone. BFGF/TGFβ1 treatment significantly up-regulated ACTA2, COL1, and FBN1 expression as compared with the group treated with bFGF alone or the untreated control. This method might thus be useful for accelerating the generation and regeneration of functional periodontium.

Estrogen inhibits lysyl oxidase and decreases mechanical function in engineered ligaments.

PubMed

Lee, Cassandra A; Lee-Barthel, Ann; Marquino, Louise; Sandoval, Natalie; Marcotte, George R; Baar, Keith

2015-05-15

Women are more likely to suffer an anterior cruciate ligament (ACL) rupture than men, and the incidence of ACL rupture in women rises with increasing estrogen levels. We used an engineered ligament model to determine how an acute rise in estrogen decreases the mechanical properties of ligaments. Using fibroblasts isolated from human ACLs from male or female donors, we engineered ligaments and determined that ligaments made from female ACL cells had more collagen and were equal in strength to those made from male ACL cells. We then treated engineered ligaments for 14 days with low (5 pg/ml), medium (50 pg/ml), or high (500 pg/ml) estrogen, corresponding to the range of in vivo serum estrogen concentrations and found that collagen within the grafts increased without a commensurate increase in mechanical strength. Mimicking the menstrual cycle, with 12 days of low estrogen followed by 2 days of physiologically high estrogen, resulted in a decrease in engineered ligament mechanical function with no change in the amount of collagen in the graft. The decrease in mechanical stiffness corresponded with a 61.7 and 76.9% decrease in the activity of collagen cross-linker lysyl oxidase with 24 and 48 h of high estrogen, respectively. Similarly, grafts treated with the lysyl oxidase inhibitor β-aminoproprionitrile (BAPN) for 24 h showed a significant decrease in ligament mechanical strength [control (CON) = 1.58 ± 0.06 N; BAPN = 1.06 ± 0.13 N] and stiffness (CON = 7.7 ± 0.46 MPa; BAPN = 6.1 ± 0.71 MPa) without changing overall collagen levels (CON = 396 ± 11.5 μg; BAPN = 382 ± 11.6 μg). Together, these data suggest that the rise in estrogen during the follicular phase decreases lysyl oxidase activity in our engineered ligament model and if this occurs in vivo may decrease the stiffness of ligaments and contribute to the elevated rate of ACL rupture in women. Copyright © 2015 the American Physiological Society.

Functional efficacy of human recombinant FGF-2s tagged with (His)6 and (His-Asn)6 at the N- and C-termini in human gingival fibroblast and periodontal ligament-derived cells.

PubMed

Lee, Ji-Hye; Lee, Ji-Eun; Kang, Kyung-Jung; Jang, Young-Joo

2017-07-01

Fibroblast growth factor (FGF) is a multifunctional growth factor that induces cell proliferation, survival, migration, and differentiation in various cell types and tissues. With these biological functions, FGF-2 has been evaluated for clinical use in the regeneration of damaged tissues. The expression of hFGF-2 in Escherichia coli and a purification system using the immobilized metal affinity chromatography (IMAC) is well established to generate a continuous supply of FGF-2. Although hexa-histidine tag (H 6 ) is commonly used for IMAC purification, hexa-histidine-asparagine tag (HN 6 ) is also efficient for purification as it is easily exposed on the surface of the protein. In this study, four different tagging constructs of hFGF-2 based on tag positions and types (H 6 -FGF2, FGF2-H 6 , HN 6 -FGF2, and FGF2-HN 6 ) were designed and expressed under the inducible T7 expression system in E. coli. The experimental conditions of expression and purification of each recombinant protein were optimized. The effective dosages of the recombinant proteins were determined based on the increase of cell proliferation in human gingival fibroblast. ED50s of H 6 -FGF2, FGF2-H 6 , HN 6 -FGF2, and FGF2-HN 6 were determined (4.42 ng/ml, 3.55 ng/ml, 3.54 ng/ml, and 4.14 ng/ml, respectively) and found to be comparable to commercial FGF-2 (3.67 ng/ml). All the recombinant hFGF-2s inhibit the osteogenic induction and mineralization in human periodontal ligament-derived cells. Our data suggested that biological activities of the recombinant hFGF-2 are irrelevant to types and positions of tags, but may have an influence on the expression efficiency and solubility. Copyright © 2017 Elsevier Inc. All rights reserved.

Characterization of mesenchymal stem cells from human dental pulp, preapical follicle and periodontal ligament.

PubMed

Navabazam, Ali Reza; Sadeghian Nodoshan, Fatemeh; Sheikhha, Mohammad Hasan; Miresmaeili, Sayyed Mohsen; Soleimani, Mehrdad; Fesahat, Farzaneh

2013-03-01

Human dental stem cells have high proliferative potential for self-renewal that is important to the regenerative capacity of the tissue. Objective : The aim was to isolate human dental pulp stem cells (DPSC), periodontal ligament stem cells (PDLSC) and periapical follicle stem cells (PAFSC) for their potential role in tissue regeneration. In this experimental study, the postnatal stem cells were isolated from dental pulp, preapical follicle and periodontal ligament .The cells were stained for different stem cell markers by immunocytochemistry. To investigate the mesenchymal nature of cells, differentiation potential along osteoblastic and adipogenic lineages and gene expression profile were performed. For proliferation potential assay, Brdu staining and growth curve tests were performed. Finally, all three cell types were compared together regarding their proliferation, differentiation and displaying phenotype. The isolated cell populations have similar fibroblastic like morphology and expressed all examined cell surface molecule markers. These cells were capable of differentiating into osteocyte with different capability and adipocyte with the same rate. PAFSCs showed more significant proliferation rate than others. Reverse transcriptase PCR (RT-PCR) for nanog, oct4, Alkaline phosphatase (ALP) and glyceraldehydes-3-phosphate dehydrogenease (GADPH) as control gene showed strong positive expression of these genes in all three isolated cell types. PDLSCs, DPSCs and PAFSCs exist in various tissues of the teeth and can use as a source of mesenchymal stem cells for developing bioengineered organs and also in craniomaxillofacial reconstruction with varying efficiency in differentiation and proliferation.

Mechanical stretch increases CCN2/CTGF expression in anterior cruciate ligament-derived cells

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

Miyake, Yoshiaki; Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama; Furumatsu, Takayuki, E-mail: matino@md.okayama-u.ac.jp

Highlights: {yields} CCN2/CTGF localizes to the ligament-to-bone interface, but is not to the midsubstance region of human anterior cruciate ligament (ACL). {yields} Mechanical stretch induces higher increase of CCN2/CTGF gene expression and protein secretion in ACL interface cells compared with ACL midsubstance cells. {yields} CCN2/CTGF treatment stimulates the proliferation of ACL interface cells. -- Abstract: Anterior cruciate ligament (ACL)-to-bone interface serves to minimize the stress concentrations that would arise between two different tissues. Mechanical stretch plays an important role in maintaining cell-specific features by inducing CCN family 2/connective tissue growth factor (CCN2/CTGF). We previously reported that cyclic tensile strain (CTS)more » stimulates {alpha}1(I) collagen (COL1A1) expression in human ACL-derived cells. However, the biological function and stress-related response of CCN2/CTGF were still unclear in ACL fibroblasts. In the present study, CCN2/CTGF was observed in ACL-to-bone interface, but was not in the midsubstance region by immunohistochemical analyses. CTS treatments induced higher increase of CCN2/CTGF expression and secretion in interface cells compared with midsubstance cells. COL1A1 expression was not influenced by CCN2/CTGF treatment in interface cells despite CCN2/CTGF stimulated COL1A1 expression in midsubstance cells. However, CCN2/CTGF stimulated the proliferation of interface cells. Our results suggest that distinct biological function of stretch-induced CCN2/CTGF might regulate region-specific phenotypes of ACL-derived cells.« less

Viability of human periodontal ligament fibroblasts in milk, Hank's balanced salt solution and coconut water as storage media.

PubMed

Souza, B D M; Lückemeyer, D D; Reyes-Carmona, J F; Felippe, W T; Simões, C M O; Felippe, M C S

2011-02-01

To evaluate the effectiveness of various storage media at 5 °C for maintaining the viability of human periodontal ligament fibroblasts (PDLF). Plates with PDLF were soaked in recently prepared Hank's balanced salt solution (HBSS), skimmed milk, whole milk, Save-A-Tooth(®) system's HBSS (Save), natural coconut water, industrialized coconut water or tap water (negative control) at 5 °C for 3, 6, 24, 48, 72, 96 and 120 h. Minimum essential medium (MEM) at 37 °C served as the positive control. PDL cell viability was determined by MTT assay. Data were statistically analysed by Kruskal-Wallis test complemented by the Scheffé test (α=5%). The greatest number of viable cells was observed for MEM. Skimmed and whole milk, followed by natural coconut water and HBSS, were the most effective media in maintaining cell viability (P<0.05). From 24 to 120 h, Save, industrialized coconut water and tap water were the worst storage media. Skimmed and whole milk had the greatest capacity to maintain PDLF viability when compared with natural coconut water, HBSS, Save, industrialized coconut water and tap water. © 2010 International Endodontic Journal.

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.

Sequential growth factor application in bone marrow stromal cell ligament engineering.

PubMed

Moreau, Jodie E; Chen, Jingsong; Horan, Rebecca L; Kaplan, David L; Altman, Gregory H

2005-01-01

In vitro bone marrow stromal cell (BMSC) growth may be enhanced through culture medium supplementation, mimicking the biochemical environment in which cells optimally proliferate and differentiate. We hypothesize that the sequential administration of growth factors to first proliferate and then differentiate BMSCs cultured on silk fiber matrices will support the enhanced development of ligament tissue in vitro. Confluent second passage (P2) BMSCs obtained from purified bone marrow aspirates were seeded on RGD-modified silk matrices. Seeded matrices were divided into three groups for 5 days of static culture, with medium supplement of basic fibroblast growth factor (B) (1 ng/mL), epidermal growth factor (E; 1 ng/mL), or growth factor-free control (C). After day 5, medium supplementation was changed to transforming growth factor-beta1 (T; 5 ng/mL) or C for an additional 9 days of culture. Real-time RT-PCR, SEM, MTT, histology, and ELISA for collagen type I of all sample groups were performed. Results indicated that BT supported the greatest cell ingrowth after 14 days of culture in addition to the greatest cumulative collagen type I expression measured by ELISA. Sequential growth factor application promoted significant increases in collagen type I transcript expression from day 5 of culture to day 14, for five of six groups tested. All T-supplemented samples surpassed their respective control samples in both cell ingrowth and collagen deposition. All samples supported spindle-shaped, fibroblast cell morphology, aligning with the direction of silk fibers. These findings indicate significant in vitro ligament development after only 14 days of culture when using a sequential growth factor approach.

From mini-invasive to non-invasive treatment using monopolar radiofrequency: the next orthopaedic frontier.

PubMed

Whipple, Terry L

2009-10-01

Tendinopathy arises from a failed tendon healing process. Current non-invasive therapeutic alternatives are anti-inflammatory in nature, and outcomes are unpredictable. The benefit of invasive alternatives resides in the induction of the healing response. A new technology that uses non-invasive monopolar capacitive coupled radiofrequency has demonstrated the ability to raise temperatures in tendons and ligaments above 50 degrees C, the threshold for collagen modulation, tissue shrinkage and recruitment of macrophages, fibroblasts, and heat shock protein factors, without damaging the overlying structures, resulting in activation of the wound healing response. Monopolar capacitive-coupled radiofrequency offers a new non-invasive choice for tendinopathies and sprained ligaments. It does not interfere with subsequent surgical procedures should they become necessary.

Solitary Fibrous Tumor in the Round Ligament of the Liver: A Fortunate Intraoperative Discovery

PubMed Central

Beyer, Laura; Delpero, Jean-Robert; Chetaille, Bruno; Sarran, Anthony; Perrot, Delphine; Moureau-Zabotto, Laurence; Guiramand, Jérôme; Bertucci, François

2012-01-01

Solitary fibrous tumors (SFTs) are mesenchymal neoplasms of fibroblastic origin, most commonly found in the pleura. Numerous extrathoracic locations have been reported during the last 2 decades. Herein, we report the first case of an SFT in the round ligament of the liver. A 46-year-old Caucasian man presented with a 12-month history of abdominal pain. An ultrasonography-guided microbiopsy first revealed a desmoid tumor. After failure of first- and second-line medical treatments (celecoxib and tamoxifen, then imatinib), histological reexamination was suspicious for a low-grade sarcoma. MRI was also suspicious for a malignant process. Hence, surgery was decided. Laparotomy found a huge and well-limited tumor that, unexpectedly, was appended to the round ligament of the liver and free from any other intra-abdominal contact. The tumor was easily removed. Excision was monobloc and macroscopically complete. Histological analysis diagnosed an SFT arising from the round ligament of the liver. No adjuvant treatment was given. Ten months after surgery, the patient is alive without any signs or symptoms of relapse. This is the first report of SFT arising from the round ligament of the liver. It illustrates the difficulty in diagnosing such tumors. Whilst diagnosis of SFT is rare, it should be kept in mind to allow early diagnosis and complete surgical resection, which provide the best chance for recovery. PMID:22666211

Solitary fibrous tumor in the round ligament of the liver: a fortunate intraoperative discovery.

PubMed

Beyer, Laura; Delpero, Jean-Robert; Chetaille, Bruno; Sarran, Anthony; Perrot, Delphine; Moureau-Zabotto, Laurence; Guiramand, Jérôme; Bertucci, François

2012-01-01

Solitary fibrous tumors (SFTs) are mesenchymal neoplasms of fibroblastic origin, most commonly found in the pleura. Numerous extrathoracic locations have been reported during the last 2 decades. Herein, we report the first case of an SFT in the round ligament of the liver. A 46-year-old Caucasian man presented with a 12-month history of abdominal pain. An ultrasonography-guided microbiopsy first revealed a desmoid tumor. After failure of first- and second-line medical treatments (celecoxib and tamoxifen, then imatinib), histological reexamination was suspicious for a low-grade sarcoma. MRI was also suspicious for a malignant process. Hence, surgery was decided. Laparotomy found a huge and well-limited tumor that, unexpectedly, was appended to the round ligament of the liver and free from any other intra-abdominal contact. The tumor was easily removed. Excision was monobloc and macroscopically complete. Histological analysis diagnosed an SFT arising from the round ligament of the liver. No adjuvant treatment was given. Ten months after surgery, the patient is alive without any signs or symptoms of relapse. This is the first report of SFT arising from the round ligament of the liver. It illustrates the difficulty in diagnosing such tumors. Whilst diagnosis of SFT is rare, it should be kept in mind to allow early diagnosis and complete surgical resection, which provide the best chance for recovery.

Integration of 3D Printed and Micropatterned Polycaprolactone Scaffolds for Guidance of Oriented Collagenous Tissue Formation In Vivo.

PubMed

Pilipchuk, Sophia P; Monje, Alberto; Jiao, Yizu; Hao, Jie; Kruger, Laura; Flanagan, Colleen L; Hollister, Scott J; Giannobile, William V

2016-03-01

Scaffold design incorporating multiscale cues for clinically relevant, aligned tissue regeneration has potential to improve structural and functional integrity of multitissue interfaces. The objective of this preclinical study is to develop poly(ε-caprolactone) (PCL) scaffolds with mesoscale and microscale architectural cues specific to human ligament progenitor cells and assess their ability to form aligned bone-ligament-cementum complexes in vivo. PCL scaffolds are designed to integrate a 3D printed bone region with a micropatterned PCL thin film consisting of grooved pillars. The patterned film region is seeded with human ligament cells, fibroblasts transduced with bone morphogenetic protein-7 genes seeded within the bone region, and a tooth dentin segment positioned on the ligament region prior to subcutaneous implantation into a murine model. Results indicate increased tissue alignment in vivo using micropatterned PCL films, compared to random-porous PCL. At week 6, 30 μm groove depth significantly enhances oriented collagen fiber thickness, overall cell alignment, and nuclear elongation relative to 10 μm groove depth. This study demonstrates for the first time that scaffolds with combined hierarchical mesoscale and microscale features can align cells in vivo for oral tissue repair with potential for improving the regenerative response of other bone-ligament complexes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Migration and Differentiation of GFP-transplanted Bone Marrow-derived Cells into Experimentally Induced Periodontal Polyp in Mice.

PubMed

Matsuda, Saeka; Shoumura, Masahito; Osuga, Naoto; Tsujigiwa, Hidetsugu; Nakano, Keisuke; Okafuji, Norimasa; Ochiai, Takanaga; Hasegawa, Hiromasa; Kawakami, Toshiyuki

2016-01-01

Perforation of floor of the dental pulp is often encountered during root canal treatment in routine clinical practice of dental caries. If perforation were large, granulation tissue would grow to form periodontal polyp. Granulation tissue consists of proliferating cells however their origin is not clear. It was shown that the cells in granulation tissue are mainly from migration of undifferentiated mesenchymal cells of the bone marrow. Hence, this study utilized GFP bone marrow transplantation mouse model. The floor of the pulp chamber in maxillary first molar was perforated using ½ dental round bur. Morphological assessment was carried out by micro CT and microscopy and GFP cell mechanism was further assessed by immunohistochemistry using double fluorescent staining with GFP-S100A4; GFP-Runx2 and GFP-CD31. Results of micro CT revealed alveolar bone resorption and widening of periodontal ligament. Histopathological examination showed proliferation of fibroblasts with some round cells and blood vessels in the granulation tissue. At 2 weeks, the outermost layer of the granulation tissue was lined by squamous cells with distinct intercellular bridges. At 4 weeks, the granulation tissue became larger than the perforation and the outermost layer was lined by relatively typical stratified squamous epithelium. Double immunofluorescent staining of GFP and Runx2 revealed that both proteins were expressed in spindle-shaped cells. Double immunofluorescent staining of GFP and CD31 revealed that both proteins were expressed in vascular endothelial cells in morphologically distinct vessels. The results suggest that fibroblasts, periodontal ligament fibroblasts and blood vessels in granulation tissue were derived from transplanted-bone marrow cells. Thus, essential growth of granulation tissue in periodontal polyp was caused by the migration of undifferentiated mesenchymal cells derived from bone marrow, which differentiated into fibroblasts and later on differentiated into other cells in response to injury.

Fibroblast Viability after Storage at 20 °C in Milk, Hank's Balanced Salt Solution and Coconut Water.

PubMed

Souza, Beatriz Dulcineia Mendes de; Alves, Ana Maria Hecke; Santos, Luciane Geanini Pena Dos; Simões, Claudia Maria de Oliveira; Felippe, Wilson Tadeu; Felippe, Mara Cristina Santos

2016-01-01

The objective of this study was to evaluate the effectiveness of various storage media at 20 °C in maintaining the viability of human periodontal ligament fibroblasts (HPLF) over time. HPLF were maintained at 20 °C in skim milk (SM), whole milk (WM), freshly prepared Hank's balanced salt solution (HBSS), Save-A-Tooth(r), natural coconut water (NCW), coconut water industrialized (ICW) and tap water (negative control) for 3, 6, 24, 48, 72, 96 and 120 h. Cells maintained in Minimal Essential Medium (MEM-37) at 37 °C served as a positive control. Cell viability was determined by MTT assay. Statistical analysis was performed by Kruskal-Wallis test and Scheffe test (α = 5%). From 24 h, NCW was significantly better in maintaining cell viability than all other tested storage media (p<0.05). SM and WM were significantly better than HBSS for up to 72 h. Save-A-Tooth(r) and ICW were the worst conservation storage media. In conclusion, the effectiveness of the tested storage media to maintain the viability of the periodontal ligament cells was as follows, in a descending order: NCW > MEM-37> SM and IM> HBSS> ICW > Save-A-Tooth(r)> tap water.

Different expression profiles of the lysyl oxidases and matrix metalloproteinases in human ACL fibroblasts after co-culture with synovial cells.

PubMed

Wang, Chunli; Xu, Chunming; Chen, Rongfu; Yang, Li; Sung, Kl Paul

2018-02-12

Purposes The anterior cruciate ligament (ACL) has poor functional healing response. The synovial tissue surrounding ACL ligament might be a major regulator of the microenvironment in the joint cavity after ACL injury, thus affecting the repair process. Using transwell co-culture, this study explored the direct influence of human synovial cells (HSCs) on ACL fibroblasts (ACLfs) by characterizing the differential expression of the lysyl oxidase family (LOXs) and matrix metalloproteinases (MMP-1, -2, -3), which facilitate extracellular matrix (ECM) repair and degradation, respectively. Methods The mRNA expression levels of LOXs and MMP-1, -2, -3 were analyzed by semi-quantitative PCR and quantitative real-time PCR. The protein expression levels of LOXs and MMP-1, -2, -3 were detected by western blot. Results We found that co-culture resulted in an increase in the mRNAs of LOXs in normal ACLfs and differentially regulated the expression of MMPs. Then we applied 12% mechanical stretch on ACLfs to induce injury and found the mRNA expression levels of LOXs in injured ACLfs were decreased in the co-culture group relative to the mono-culture group. Conversely, the mRNA expression levels of MMPs in injured ACLfs were promoted in the co-culture group compared with the mono-culture group. At translational level, we found that LOXs were lower while MMPs were highly expressed in the co-culture group compared to the mono-culture group. Conclusions The co-culture of ACLfs and HSCs, which mimicked the cell-to-cell contact in a micro-environment, could contribute to protein modulators for wound healing, inferring the potential reason for the poor self-healing of injured ACL.

Mechanomimetic hydrogels for vocal fold lamina propria regeneration.

PubMed

Kutty, Jaishankar K; Webb, Ken

2009-01-01

Vocal fold injury commonly leads to reduced vocal quality due to scarring-induced alterations in matrix composition and tissue biomechanics. The long-term hypothesis motivating our work is that rapid restoration of phonation and the associated dynamic mechanical environment will reduce scarring and promote regenerative healing. Toward this end, the objective of this study was to develop mechanomimetic, degradable hydrogels approximating the viscoelastic properties of the vocal ligament and mucosa that may be photopolymerized in situ to restore structural integrity to vocal fold tissues. The tensile and rheological properties of hydrogels (targeting the vocal ligament and mucosa, respectively) were varied as a function of macromer concentration. PEG diacrylate-based hydrogels exhibited linear stress-strain response and elastic modulus consistent with the properties of the vocal ligament at low strains (0-15%), but did not replicate the non-linear behavior observed in native tissue at higher strains. Methacrylated hyaluronic acid hydrogels displayed dynamic viscosity consistent with native vocal mucosa, while elastic shear moduli values were several-fold higher. Cell culture studies indicated that both hydrogels supported spreading, proliferation and collagen/proteoglycan matrix deposition by encapsulated fibroblasts throughout the 3D network.

An ultrastructural study of calcitonin gene-related peptide-immunoreactive nerve fibers innervating the rat posterior longitudinal ligament. A morphologic basis for their possible efferent actions.

PubMed

Imai, S; Konttinen, Y T; Tokunaga, Y; Maeda, T; Hukuda, S; Santavirta, S

1997-09-01

The present study investigated ultrastructural characteristics of calcitonin gene-related peptide-immunoreactive nerve fibers in the posterior longitudinal ligament of the rat lumbar spine. To provide a morphologic basis for assessment of the afferent and, in particular, efferent functions of calcitonin gene-related peptide immunoreactive nerves in the posterior longitudinal ligament and their eventual role in degenerative spondylarthropathies and low back pain. Previous studies using light-microscopic localization of sensory neuronal markers such as calcitonin gene-related peptide have reported the presence of sensory fibers in the supporting structures of the vertebral column. Meanwhile, accumulating research data have suggested efferent properties for calcitonin gene-related peptide, i.e., a trophic action that alters the intrinsic properties of target cells not through transient action of synaptic transmission, but through long-lasting signal transmission by the secreted neuropeptides. To verify such trophic, paracrine actions of the calcitonin gene-related peptide-containing fibers in the posterior longitudinal ligament, however, ultrastructural details of the terminals and their spatial relationship to their eventual target structures have to be elucidated. Rat posterior longitudinal ligaments were stained immunohistochemically for calcitonin gene-related peptide. Light-microscopic analysis of the semithin sections facilitated subsequent electron microscopy of specific sites of the posterior longitudinal ligament to determine ultrastructural details and nerve fiber-target relationships. The rat lumbar posterior longitudinal ligament was found to be innervated by two distinctive calcitonin gene-related peptide immunoreactive nerve networks. In immunoelectronmicroscopy, the fibers of the deep network had numerous free nerve endings, whereas those of the superficial network showed spatial associations with other non-calcitonin gene-related peptide immunoreactive components of the network. In both systems, naked axons not covered by the Schwann cells made close spatial contact with smooth muscle cells: of blood vessels and resident posterior longitudinal ligament fibroblasts. The ultrastructural characteristics of the innervation of the rat posterior longitudinal ligament would be compatible not only with a nociceptive function, but also with neuromodulatory, vasoregulatory, and trophic functions, as has already been established in some visceral organs.

Different effects of 25-kDa amelogenin on the proliferation, attachment and migration of various periodontal cells

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

Li, Xiting; Shu, Rong, E-mail: shurong123@hotmail.com; Liu, Dali

Previous studies have assumed that amelogenin is responsible for the therapeutic effect of the enamel matrix derivative (EMD) in periodontal tissue healing and regeneration. However, it is difficult to confirm this hypothesis because both the EMD and the amelogenins are complex mixtures of multiple proteins. Further adding to the difficulties is the fact that periodontal tissue regeneration involves various types of cells and a sequence of associated cellular events including the attachment, migration and proliferation of various cells. In this study, we investigated the potential effect of a 25-kDa recombinant porcine amelogenin (rPAm) on primarily cultured periodontal ligament fibroblasts (PDLF),more » gingival fibroblasts (GF) and gingival epithelial cells (GEC). The cells were treated with 25-kDa recombinant porcine amelogenin at a concentration of 10 {mu}g/mL. We found that rPAm significantly promoted the proliferation and migration of PDLF, but not their adhesion. Similarly, the proliferation and adhesion of GF were significantly enhanced by treatment with rPAm, while migration was greatly inhibited. Interestingly, this recombinant protein inhibited the growth rate, cell adhesion and migration of GEC. These data suggest that rPAm may play an essential role in periodontal regeneration through the activation of periodontal fibroblasts and inhibition of the cellular behaviors of gingival epithelial cells.« less

Mechanical stretch increases CCN2/CTGF expression in anterior cruciate ligament-derived cells.

PubMed

Miyake, Yoshiaki; Furumatsu, Takayuki; Kubota, Satoshi; Kawata, Kazumi; Ozaki, Toshifumi; Takigawa, Masaharu

2011-06-03

Anterior cruciate ligament (ACL)-to-bone interface serves to minimize the stress concentrations that would arise between two different tissues. Mechanical stretch plays an important role in maintaining cell-specific features by inducing CCN family 2/connective tissue growth factor (CCN2/CTGF). We previously reported that cyclic tensile strain (CTS) stimulates α1(I) collagen (COL1A1) expression in human ACL-derived cells. However, the biological function and stress-related response of CCN2/CTGF were still unclear in ACL fibroblasts. In the present study, CCN2/CTGF was observed in ACL-to-bone interface, but was not in the midsubstance region by immunohistochemical analyses. CTS treatments induced higher increase of CCN2/CTGF expression and secretion in interface cells compared with midsubstance cells. COL1A1 expression was not influenced by CCN2/CTGF treatment in interface cells despite CCN2/CTGF stimulated COL1A1 expression in midsubstance cells. However, CCN2/CTGF stimulated the proliferation of interface cells. Our results suggest that distinct biological function of stretch-induced CCN2/CTGF might regulate region-specific phenotypes of ACL-derived cells. Copyright © 2011 Elsevier Inc. All rights reserved.

A collagen and elastic network in the wing of the bat.

PubMed

Holbrook, K A; Odland, G F

1978-05-01

Bundles of collagen fibrils, elastic fibres and fibroblasts are organized into a network that lies in the plane of a large portion of the bat wing. By ultrastructural (TEM and SEM) and biochemical analyses it was found that individual bundles of the net are similar to elastic ligaments. Although elastic fibres predominate, they are integrated and aligned in parallel with small bundles of collagen. A reticulum of fibroblasts, joined by focal junctions, forms a cellular framework throughout each bundle. Because of the unique features of the fibre bundles of the bat's wing, in particular their accessibility, and the parallel alignment of the collagen fibrils and elastic fibres in each easily isolatable fibre bundle, they should prove a most valuable model for connective tissue studies, particularly for the study of collagen-elastin interactions.

Generation of functional hepatocyte-like cells from human deciduous periodontal ligament stem cells.

PubMed

Vasanthan, Punitha; Jayaraman, Pukana; Kunasekaran, Wijenthiran; Lawrence, Anthony; Gnanasegaran, Nareshwaran; Govindasamy, Vijayendran; Musa, Sabri; Kasim, Noor Hayaty Abu

2016-08-01

Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases.

Generation of functional hepatocyte-like cells from human deciduous periodontal ligament stem cells

NASA Astrophysics Data System (ADS)

Vasanthan, Punitha; Jayaraman, Pukana; Kunasekaran, Wijenthiran; Lawrence, Anthony; Gnanasegaran, Nareshwaran; Govindasamy, Vijayendran; Musa, Sabri; Kasim, Noor Hayaty Abu

2016-08-01

Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases.

The Cytolethal Distending Toxin Induces Receptor Activator of NF-κB Ligand Expression in Human Gingival Fibroblasts and Periodontal Ligament Cells

PubMed Central

Belibasakis, G. N.; Johansson, A.; Wang, Y.; Chen, C.; Kalfas, S.; Lerner, U. H.

2005-01-01

Actinobacillus actinomycetemcomitans is associated with localized aggressive periodontitis, a disease characterized by rapid loss of the alveolar bone surrounding the teeth. Receptor activator of NF-κB Ligand (RANKL) and osteoprotegerin (OPG) are two molecules that regulate osteoclast formation and bone resorption. RANKL induces osteoclast differentiation and activation, whereas OPG blocks this process by acting as a decoy receptor for RANKL. The purpose of this study was to investigate the effect of A. actinomycetemcomitans on the expression of RANKL and OPG in human gingival fibroblasts and periodontal ligament cells. RANKL mRNA expression was induced in both cell types challenged by A. actinomycetemcomitans extract, whereas OPG mRNA expression remained unaffected. Cell surface RANKL protein was also induced by A. actinomycetemcomitans, whereas there was no change in OPG protein secretion. A cytolethal distending toxin (Cdt) gene-knockout strain of A. actinomycetemcomitans did not induce RANKL expression, in contrast to its wild-type strain. Purified Cdt from Haemophilus ducreyi alone, or in combination with extract from the A. actinomycetemcomitans cdt mutant strain, induced RANKL expression. Pretreatment of A. actinomycetemcomitans wild-type extract with Cdt antiserum abolished RANKL expression. In conclusion, A. actinomycetemcomitans induces RANKL expression in periodontal connective tissue cells. Cdt is crucial for this induction and may therefore be involved in the pathological bone resorption during the process of localized aggressive periodontitis. PMID:15618171

Induced Pluripotent Stem (iPS) Cells in Dentistry: A Review

PubMed Central

Malhotra, Neeraj

2016-01-01

iPS cells are derived from somatic cells via transduction and expression of selective transcription factors. Both viral-integrating (like retroviral) and non-integrating (like, mRNA or protein-based) techniques are available for the production of iPS cells. In the field of dentistry, iPS cells have been derived from stem cells of apical papilla, dental pulp stem cells, and stem cells from exfoliated deciduous teeth, gingival and periodontal ligament fibroblasts, and buccal mucosa fibroblasts. iPS cells have the potential to differentiate into all derivatives of the 3 primary germ layers i.e. ectoderm, endoderm, and mesoderm. They are autogeneically accessible, and can produce patient-specific or disease-specific cell lines without the issue of ethical controversy. They have been successfully tested to produce mesenchymal stem cells-like cells, neural crest-like cells, ameloblasts-like cells, odontoblasts-like cells, and osteoprogenitor cells. These cells can aid in regeneration of periodontal ligament, alveolar bone, cementum, dentin-pulp complex, as well as possible Biotooth formation. However certain key issues like, epigenetic memory of iPS cells, viral-transduction, tumorgenesis and teratoma formation need to be overcome, before they can be successfully used in clinical practice. The article discusses the sources, pros and cons, and current applications of iPS cells in dentistry with an emphasis on encountered challenges and their solutions. PMID:27572712

Platelets and Plasma Proteins Are Both Required to Stimulate Collagen Gene Expression by Anterior Cruciate Ligament Cells in Three-Dimensional Culture

PubMed Central

Cheng, Mingyu; Wang, Hao; Yoshida, Ryu

2010-01-01

Collagen–platelet (PL)-rich plasma composites have shown in vivo potential to stimulate anterior cruciate ligament (ACL) healing at early time points in large animal models. However, little is known about the cellular mechanisms by which the plasma component of these composites may stimulate healing. We hypothesized that the components of PL-rich plasma (PRP), namely the PLs and PL-poor plasma (PPP), would independently significantly influence ACL cell viability and metabolic activity, including collagen gene expression. To test this hypothesis, ACL cells were cultured in a collagen type I hydrogel with PLs, PPP, or the combination of the two (PRP) for 14 days. The inclusion of PLs, PPP, and PRP all significantly reduced the rate of cell apoptosis and enhanced the metabolic activity of fibroblasts in the collagen hydrogel. PLs promoted fibroblast-mediated collagen scaffold contraction, whereas PPP inhibited this contraction. PPP and PRP both promoted cell elongation and the formation of wavy fibrous structure in the scaffolds. The addition of only PLs or only plasma proteins did not significantly enhance gene expression of collagen types I and III but the combination, as PRP, did. Our findings suggest that the addition of both PLs and plasma proteins to collagen hydrogel may be useful in stimulating ACL healing by enhancing ACL cell viability, metabolic activity, and collagen synthesis. PMID:19958169

Angiotensin II Type 1 Receptor Knockdown Impairs Interleukin-1β-Induced Cytokines in Human Periodontal Fibroblasts.

PubMed

Gabriele, Lilian Gobbo; Morandini, Ana Carolina; Dionísio, Thiago José; Santos, Carlos Ferreira

2017-01-01

The renin-angiotensin (Ang) system (RAS) has been reported as an important modulator of inflammatory and immune responses. Evidence suggests an alternative Ang 1-7/Mas receptor axis as counter-regulatory to the classic RAS Ang II/Ang II Type 1 (AT1) receptor axis. It is known that periodontal pathogens elicit host-derived immune response due to release of cytokines such as interleukin (IL)-1β, and fibroblasts are among the most numerous sentinel cells that contribute to this production. The aim of this study is to determine whether AT1 receptor (AT1R) contributes to production of inflammatory cytokines that are important for periodontal pathogenesis using primary human gingival fibroblasts (HGFs) and human periodontal ligament fibroblasts (HPLFs) stimulated with IL-1β. Through RNA interference or pharmacologic inhibition using AT1R antagonist losartan, HGF and HPLF were stimulated by IL-1β for 3 (messenger RNA [mRNA]) or 24 (protein) hours. IL-1β upregulated mRNA expression of AT1R, IL-1β, IL-6, IL-8, tumor necrosis factor-alpha, and osteoprotegerin (OPG) in HGF and HPLF. AT1R knockdown impaired IL-1β-induced IL-6 and IL-8 secretion in cultured HGF and HPLF. AT1R silencing also increased OPG gene expression in HGF only. Pharmacologic inhibition of AT1R through losartan modulated mRNA transcription of IL-6 and IL-8 in HPLF but not in HGF. In contrast, IL-1β-induced secretion of IL-6 and IL-8 was not influenced by losartan in HGF or HPLF. These results suggest that AT1R knockdown and AT1R pharmacologic blockade by losartan may differently control balance of inflammatory cytokines, such as IL-6 and IL-8, in primary human periodontal fibroblasts.

Histologic anatomy of the lesser metatarsophalangeal joint plantar plate.

PubMed

Gregg, J; Marks, P; Silberstein, M; Schneider, T; Kerr, J

2007-03-01

The plantar plate is the fibrocartilaginous structure that supports the ball of the foot, withstanding considerable compressive and tensile forces. This study describes the morphology of the plantar plate in order to understand its function and the pathologic disorders associated with it. Eight lesser metatarsophalangeal joint plantar plates from three soft-embalmed cadavers (74-92 years, two males, one female), and eight lesser metatarsophalangeal joint plantar plates from a fresh cadaver (19-year-old male) were obtained for histology assessment. Paraffin sections (10 microm) in the longitudinal and transverse planes were analyzed with bright-field and polarized light microscopy. The central plantar plate collagen bundles run in the longitudinal plane with varying degrees of undulation. The plantar plate borders run transversely and merge with collateral ligaments and the deep transverse intermetatarsal ligament. Bright-field microscopic evaluation shows the plantar aspect of the plantar plate becomes ligament-like the further distally it tapers, containing fewer chondrocytes, and a greater abundance of fibroblasts. The enthesis reveals longitudinal and interwoven collagen bundles entering the proximal phalanx with multiple interdigitations. Longer interdigitations centrally compared to the dorsal and plantar aspects suggest that the central fibers experience the greatest loads.

Electrospun microcrimped fibers with nonlinear mechanical properties enhance ligament fibroblast phenotype.

PubMed

Grace Chao, Pen-hsiu; Hsu, Hsiang-Yi; Tseng, Hsiao-Yun

2014-09-01

Fiber structure and order greatly impact the mechanical behavior of fibrous materials. In biological tissues, the nonlinear mechanics of fibrous scaffolds contribute to the functionality of the material. The nonlinear mechanical properties of the wavy structure (crimp) in collagen allow tissue flexibility while preventing over-extension. A number of approaches have tried to recreate this complex mechanical functionality. We generated microcrimped fibers by briefly heating electrospun parallel fibers over the glass transition temperature or by ethanol treatment. The crimp structure is similar to those of collagen fibers found in native aorta, intestines, or ligaments. Using poly-L-lactic acid fibers, we demonstrated that the bulk materials exhibit changed stress-strain behaviors with a significant increase in the toe region in correlation to the degree of crimp, similar to those observed in collagenous tissues. In addition to mimicking the stress-strain behavior of biological tissues, the microcrimped fibers are instructive in cell morphology and promote ligament phenotypic gene expression. This effect can be further enhanced by dynamic tensile loading, a physiological perturbation in vivo. This rapid and economical approach for microcrimped fiber production provides an accessible platform to study structure-function relationships and a novel functional scaffold for tissue engineering and cell mechanobiology studies.

Synergistic cytotoxic action of vitamin C and vitamin K3.

PubMed

Zhang, W; Negoro, T; Satoh, K; Jiang, Y; Hashimoto, K; Kikuchi, H; Nishikawa, H; Miyata, T; Yamamoto, Y; Nakano, K; Yasumoto, E; Nakayachi, T; Mineno, K; Satoh, T; Sakagami, H

2001-01-01

We investigated the combination effect of sodium ascorbate (vitamin C) and menadione (vitamin K3) on the viability of various cultured cells. Human oral squamous cell carcinoma (HSC-2, HSC-3) and human promyelocytic leukemia (HL-60) cells were more sensitive to these vitamins as compared to normal cells (human gingival fibroblast HGF, human periodontal ligament fibroblast HPLF, human pulp cell HPC). The combination of vitamin C and vitamin K3 produced synergistic cytotoxicity against all these 6 cell lines. Treatment with vitamin C or vitamin K3, or their combination, induced internucleosomal DNA fragmentation only in HL-60 cells, but not in the oral tumor cell lines (HSC-2, HSC-3, HSG). ESR spectroscopy showed that vitamins C and K3 produce radicals under alkaline conditions and that the combination of these two vitamins synergistically enhanced their respective radical intensities.

Effect of fiber diameter and orientation on fibroblast morphology and proliferation on electrospun poly(D,L-lactic-co-glycolic acid) meshes.

PubMed

Bashur, Chris A; Dahlgren, Linda A; Goldstein, Aaron S

2006-11-01

Engineered ligament tissues are promising materials for the repair of tears and ruptures, but require the development of biomaterial scaffolds that not only support physiologically relevant loads, but also possess architectures capable of orienting cell adhesion and extracellular matrix deposition. Based on evidence that micron-scale topographic features induce cell orientation through a contact guidance phenomenon, we postulate that oriented micron-scale fiber meshes-formed by the electrospinning process-can regulate cell morphology. To test this, fused fiber meshes of poly(d,l-lactic-co-glycolic acid) (PLGA) were electrospun onto rigid supports under conditions that produced mean fiber diameters of 0.14-3.6 microm, and angular standard deviations of 31-60 degrees . Analysis of the morphology of adherent NIH 3T3 fibroblasts indicated that projected cell area and aspect ratio increased systematically with both increasing fiber diameter and degree of fiber orientation. Importantly, cell morphology on 3.6 microm fibers was similar to that on spincoated PLGA films. Finally, cell densities on electrospun meshes were not significantly different from spincoated PLGA, indicating that cell proliferation is not sensitive to fiber diameter or orientation.

Differentiating zones at periodontal ligament-bone and periodontal ligament-cementum entheses.

PubMed

Lee, J-H; Pryce, B A; Schweitzer, R; Ryder, M I; Ho, S P

2015-12-01

The structural and functional integrity of bone-periodontal ligament (PDL)-cementum complex stems from the load-bearing attachment sites (entheses) between soft (PDL) and hard (bone, cementum) tissues. These attachment sites are responsible for the maintenance of a bone-PDL-cementum complex biomechanical function. The objective was to investigate changes in spatiotemporal expression of key biomolecules in developing and functionally active entheses. Multilabeling technique was performed on hemimandibles of 3 wk and 3 mo-old scleraxis-GFP transgenic mice for CD146, CD31, NG2, osterix and bone sialoprotein. Regions of dominant stretch within the PDL were evaluated by identifying directionality of collagen fibrils, PDL fibroblasts and PDL cell cytoskeleton. CD146+ cells adjacent to CD31+ vasculature were identified at PDL-bone enthesis. NG2+ cells were located at coronal bone-PDL and apical cementum-PDL entheses in the 3-wk-old group, but at 3 mo, NG2 was positive at the entheses of the apical region and alveolar crest. NG2 and osterix were colocalized at the osteoid and cementoid regions of the PDL-bone and PDL-cementum entheses. Bone sialoprotein was prominent at the apical region of 3-wk-old mice. The directionality of collagen fibers, fibroblasts and their cytoskeleton overlapped, except in the apical region of 3 wk. Colocalization of biomolecules at zones of the PDL adjacent to attachment sites may be essential for the formation of precementum and osteoid interfaces at a load-bearing bone-PDL-tooth fibrous joint. Biophysical cues resulting from development and function can regulate recruitment and differentiation of stem cells potentially from a vascular origin toward osteo- and cemento-blastic lineages at the PDL-bone and PDL-cementum entheses. Investigating the coupled effect of biophysical and biochemical stimuli leading to cell differentiation at the functional attachment sites is critical for developing regeneration strategies to enable functional reconstruction of the periodontal complex. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of diode low-level lasers on fibroblasts derived from human periodontal tissue: a systematic review of in vitro studies.

PubMed

Ren, Chong; McGrath, Colman; Jin, Lijian; Zhang, Chengfei; Yang, Yanqi

2016-09-01

This study aimed to systematically assess the parameter-specific effects of the diode low-level laser on human gingival fibroblasts (HGFs) and human periodontal ligament fibroblasts (HPDLFs). An extensive search was performed in major electronic databases including PubMed (1997), EMBASE (1947) and Web of Science (1956) and supplemented by hand search of reference lists and relevant laser journals for cell culture studies investigating the effect of diode low-level lasers on HGFs and HPDLFs published from January 1995 to December 2015. A total of 21 studies were included after screening 324 independent records, amongst which eight targeted HPDLFs and 13 focussed on HGFs. The diode low-level laser showed positive effects on promoting fibroblast proliferation and osteogenic differentiation and modulating cellular inflammation via changes in gene expression and the release of growth factors, bone-remodelling markers or inflammatory mediators in a parameter-dependent manner. Repeated irradiations with wavelengths in the red and near-infrared range and at an energy density below 16 J/cm(2) elicited favourable responses. However, considerable variations and weaknesses in the study designs and laser protocols limited the interstudy comparison and clinical transition. Current evidence showed that diode low-level lasers with adequate parameters stimulated the proliferation and modulated the inflammation of fibroblasts derived from human periodontal tissue. However, further in vitro studies with better designs and more appropriate study models and laser parameters are anticipated to provide sound evidence for clinical studies and practice.

Bone morphogenetic protein 7 (BMP-7) influences tendon-bone integration in vitro.

PubMed

Schwarting, Tim; Lechler, Philipp; Struewer, Johannes; Ambrock, Marius; Frangen, Thomas Manfred; Ruchholtz, Steffen; Ziring, Ewgeni; Frink, Michael

2015-01-01

Successful graft ingrowth following reconstruction of the anterior cruciate ligament is governed by complex biological processes at the tendon-bone interface. The aim of this study was to investigate in an in vitro study the effects of bone morphogenetic protein 7 (BMP-7) on tendon-bone integration. To study the biological effects of BMP-7 on the process of tendon-bone-integration, two independent in vitro models were used. The first model involved the mono- and coculture of bovine tendon specimens and primary bovine osteoblasts with and without BMP-7 exposure. The second model comprised the mono- and coculture of primary bovine osteoblasts and fibroblasts. Alkaline phosphatase (ALP), lactate dehydrogenase (LDH), lactate and osteocalcin (OCN) were analyzed by ELISA. Histological analysis and electron microscopy of the tendon specimens were performed. In both models, positive effects of BMP-7 on ALP enzyme activity were observed (p<0.001). Additionally, similar results were noted for LDH activity and lactate concentration. BMP-7 stimulation led to a significant increase in OCN expression. Whereas the effects of BMP-7 on tendon monoculture peaked during an early phase of the experiment (p<0.001), the cocultures showed a maximal increase during the later stages (p<0.001). The histological analysis showed a stimulating effect of BMP-7 on extracellular matrix formation. Organized ossification zones and calcium carbonate-like structures were only observed in the BMP-stimulated cell cultures. This study showed the positive effects of BMP-7 on the biological process of tendon-bone integration in vitro. Histological signs of improved mineralization were paralleled by increased rates of osteoblast-specific protein levels in primary bovine osteoblasts and fibroblasts. Our findings indicated a role for BMP-7 as an adjuvant therapeutic agent in the treatment of ligamentous injuries, and they emphasized the importance of the transdifferentiation process of tendinous fibroblasts at the tendon-bone interface.

[EFFECT OF RECOMBINANT ADENOVIRUS-BONE MORPHOGENETIC PROTEIN 12 TRANSFECTION ON DIFFERENTIATION OF PERIPHERAL BLOOD MESENCHYMAL STEM CELLS INTO TENDON/LIGAMENT CELLS].

PubMed

Fu, Weili; Chen, Gang; Tang, Xin; Li, Qi; Ll, Jian

2015-04-01

To research the effect of recombinant adenovirus-bone morphogenetic protein 12 (Ad-BMP-12) transfection on the differentiation of peripheral blood mesenchymal stem cells (MSCs) into tendon/ligament cells. Peripheral blood MSCs were isolated from New Zealand rabbits (3-4 months old) and cultured in vitro until passage 3. The recombinant adenoviral vector system was prepared using AdEasy system, then transfected into MSCs at passage 3 (transfected group); untransfected MSCs served as control (untransfected group). The morphological characteristics and growth of transfected cells were observed under inverted phase contrast microscope. The transfection efficiency and green fluorescent protein (GFP) expression were detected by flow cytometry (FCM) and fluorescence microscopy. After cultured for 14 days in vitro, the expressions of tendon/ligament-specific markers were determined by immunohistochemistry and real-time fluorescent quantitative PCR. GFP expression could be observed in peripheral blood MSCs at 8 hours after transfection. At 24 hours after transfection, the cells had clear morphology and grew slowly under inverted phase contrast microscope and almost all expressed GFP at the same field under fluorescence microscopy. FCM analysis showed that the transfection efficiency of the transfected group was 99.57%, while it was 2.46% in the untransfected group. The immunohistochemistry showed that the expression of collagen type I gradually increased with culture time in vitro. Real-time fluorescent quantitative PCR results showed that the mRNA expressions of the tendon/ligament-specific genes (Tenomodulin, Tenascin-C, and Decorin) in the transfected group were significantly higher than those in untransfected group (0.061+/- 0.013 vs. 0.004 +/- 0.002, t = -7.700, P=0.031; 0.029 +/- 0.008 vs. 0.003 +/- 0.001, t = -5.741, P=0.020; 0.679 +/- 0.067 vs. 0.142 +/- 0.024, t = -12.998, P=0.000). Ad-BMP-12 can significantly promote differentiation of peripheral blood MSCs into tendon/ligament fibroblasts and enhance the expressions of tendon/ligament-specific phenotypic differentiation, which would provide the evidence for peripheral blood MSCs applied for tendon/ligament regeneration.

Tissue-engineered collateral ligament composite allografts for scapholunate ligament reconstruction: an experimental study.

PubMed

Endress, Ryan; Woon, Colin Y L; Farnebo, Simon J; Behn, Anthony; Bronstein, Joel; Pham, Hung; Yan, Xinrui; Gambhir, Sanjiv S; Chang, James

2012-08-01

In patients with chronic scapholunate (SL) dissociation or dynamic instability, ligament repair is often not possible, and surgical reconstruction is indicated. The ideal graft ligament would recreate both anatomical and biomechanical properties of the dorsal scapholunate ligament (dorsal SLIL). The finger proximal interphalangeal joint (PIP joint) collateral ligament could possibly be a substitute ligament. We harvested human PIP joint collateral ligaments and SL ligaments from 15 cadaveric limbs. We recorded ligament length, width, and thickness, and measured the biomechanical properties (ultimate load, stiffness, and displacement to failure) of native dorsal SLIL, untreated collateral ligaments, decellularized collateral ligaments, and SL repairs with bone-collateral ligament-bone composite collateral ligament grafts. As proof of concept, we then reseeded decellularized bone-collateral ligament-bone composite grafts with green fluorescent protein-labeled adipo-derived mesenchymal stem cells and evaluated them histologically. There was no difference in ultimate load, stiffness, and displacement to failure among native dorsal SLIL, untreated and decellularized collateral ligaments, and SL repairs with tissue-engineered collateral ligament grafts. With pair-matched untreated and decellularized scaffolds, there was no difference in ultimate load or stiffness. However, decellularized ligaments revealed lower displacement to failure compared with untreated ligaments. There was no difference in displacement between decellularized ligaments and native dorsal SLIL. We successfully decellularized grafts with recently described techniques, and they could be similarly reseeded. Proximal interphalangeal joint collateral ligament-based bone-collateral ligament-bone composite allografts had biomechanical properties similar to those of native dorsal SLIL. Decellularization did not adversely affect material properties. These tissue-engineered grafts may offer surgeons another option for reconstruction of chronic SL instability. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Effects of Shock Waves on Expression of IL-6, IL-8, MCP-1, and TNF-α Expression by Human Periodontal Ligament Fibroblasts: An In Vitro Study

PubMed Central

Cai, Zhiyu; Falkensammer, Frank; Andrukhov, Oleh; Chen, Jiang; Mittermayr, Rainer; Rausch-Fan, Xiaohui

2016-01-01

Background Extracorporeal shock wave therapy (ESWT) can modulate cell behavior through mechanical information transduction. Human periodontal ligament fibroblasts (hPDLF) are sensible to mechanical stimulus and can express pro-inflammatory molecules in response. The aim of this study was to evaluate the impacts of shock waves on interleukin-6 (IL-6), interleukin-8 (IL-8), monocyte chemotactic protein 1 (MCP-1), and tumor necrosis factor-alpha (TNF-α) expression by hPDLF. Material/Methods After being treated by shock waves with different parameters (100–500 times, 0.05–0.19 mJ/mm2), cell viability was tested using CCK-8. IL-6, IL-8, MCP-1, and TNF-α gene expression was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and IL-6 and IL-8 protein was measured by enzyme-linked immunosorbent assay (ELISA) at different time points. Results Shock waves with the parameters used in this study had no significant effects on the viability of hPDLF. A statistical inhibition of IL-6, IL-8, MCP-1, and TNF-α expression during the first few hours was observed (P<0.05). Expression of IL-8 was significantly elevated in the group receiving the most pulses of shock wave (500 times) after 4 h (P<0.05). At 8 h and 24 h, all treated groups demonstrated significantly enhanced IL-6 expression (P<0.05). TNF-α expression in the groups receiving more shock pulses (300, 500 times) or the highest energy shock treatment (0.19 mJ/mm2) was statistically decreased (P<0.05) at 24 h. Conclusions Under the condition of this study, a shock wave with energy density no higher than 0.19 mJ/mm2 and pulses no more than 500 times elicited no negative effects on cell viability of hPDLF. After a uniform initial inhibition impact on expression of inflammatory mediators, a shock wave could cause dose-related up-regulation of IL-6 and IL-8 and down-regulation of TNF-α. PMID:26994898

Biocompatibility of polyhydroxyalkanoate as a potential material for ligament and tendon scaffold material.

PubMed

Rathbone, S; Furrer, P; Lübben, J; Zinn, M; Cartmell, S

2010-06-15

There is a strong need for new biodegradable materials that are suitable for scaffolds in tissue engineering of tendons and ligaments. In many cases, quick degradation rates are favorable, however, with respect to ligament and tendon replacement, slowly degrading polymers are clearly favored. Prime candidates are members of the large class of polyhydroxyalkanoates (PHAs), which are thermoplastic/elastomeric biopolyesters that are slowly degraded by surface erosion. Moreover, their physico-mechanical properties can be tailored during biosynthesis in bacteria or by chemical modifications. They may be spun into fibers, coated on surfaces or be part of composites. This study has investigated the biocompatability of seven different thermoplastic or elastomeric PHAs using L929 murine fibroblast cells. Cell viability and proliferation over 7 days was analyzed with live/dead staining and a picogreen assay. In addition, extracellular matrix production was measured with the hydroxyproline assay after 14 days. It was found that cell attachment to the PHA film ranged from 85-99% after 7 days. Three PHA films (PHBV (92/8), PHOUE-POSS and PHUE-O3) supported similar cell viability in comparison to the controls performed on tissue culture plastic (polystyrene), whereas the biomaterials (PHUA, PHUE, PHB and PHOUE) showed fewer viable cells than in controls. PHB, PHUE-O3, and PHBV with a water contact angle below 85 degrees supported a similar amount of collagen production in comparison to the tissue culture plastic controls. PHUA, PHUE, PHOUE, and PHOUE-POSS showed a decrease in collagen production in comparison to the controls after 14 days. Overall, PHB, PHBV, and PHUE-O3 demonstrated good performance with regards to potential use as a tissue-engineering scaffold. (c) 2009 Wiley Periodicals, Inc.

Nano/micro hybrid scaffold of PCL or P3HB nanofibers combined with silk fibroin for tendon and ligament tissue engineering.

PubMed

Naghashzargar, Elham; Farè, Silvia; Catto, Valentina; Bertoldi, Serena; Semnani, Dariush; Karbasi, Saeed; Tanzi, Maria Cristina

2015-07-04

A novel biodegradable nano/micro hybrid structure was obtained by electrospinning P3HB or PCL nanofibers onto a twisted silk fibroin (SF) structure, with the aim of fabricating a suitable scaffold for tendon and ligament tissue engineering. The electrospinning (ES) processing parameters for P3HB and PCL were optimized on 2D samples, and applied to produce two different nano/micro hybrid constructs (SF/ES-PCL and SF/ES-P3HB).Morphological, chemico-physical and mechanical properties of the novel hybrid scaffolds were evaluated by SEM, ATR FT-IR, DSC, tensile and thermodynamic mechanical tests. The results demonstrated that the nanofibers were tightly wrapped around the silk filaments, and the crystallinity of the SF twisted yarns was not influenced by the presence of the electrospun polymers. The slightly higher mechanical properties of the hybrid constructs confirmed an increase of internal forces due to the interaction between nano and micro components. Cell culture tests with L929 fibroblasts, in the presence of the sample eluates or in direct contact with the hybrid structures, showed no cytotoxic effects and a good level of cytocompatibility of the nano/micro hybrid structures in term of cell viability, particularly at day 1. Cell viability onto the nano/micro hybrid structures decreased from the first to the third day of culture when compared with the control culture plastic, but appeared to be higher when compared with the uncoated SF yarns. Although additional in vitro and in vivo tests are needed, the original fabrication method here described appears promising for scaffolds suitable for tendon and ligament tissue engineering.

Human periodontal fibroblasts viability stored in Custodiol® , coconut water and propolis. An ex vivo study.

PubMed

Awawdeh, Lama; Haimour, Rana Naman; Al-Jundi, Suhad Hussein; Al-Qaoud, Khaled

2018-04-17

Successful replantation of an avulsed tooth depends on the regeneration of periodontal ligament (PDL) attachment which is affected by the transport medium, dry time and storage time. Various storage media have been studied but the search for the optimum storage medium is still needed to determine the ideal material and storage time to maintain PDL cells. The aim of this study was to determine the ability of Custodiol ® , coconut water from different stages of maturity and propolis as storage media for avulsed teeth by evaluating the viability of PDL cells for different time intervals. PDL cultures were subjected to Cutodiol ® , immature, half mature, and mature coconut water, and different concentrations of propolis in DMEM. Culture plates with the tested media were incubated for 1, 2, 6, 24, 48, 72 and 168 h. PDL fibroblast cell viability was assessed by MTT assay. Coconut water showed significantly higher viability of cells than other groups at 6 h with half mature coconut water being superior. Propolis at 6.25 mg/mL in DMEM resulted in 138% viable PDL and it was able to preserve PDL cells for up to 168 h. Half mature and mature coconut water are superior storage media if replantation of avulsed teeth is within 6 h. Propolis in DMEM could be a potential storage media for prolonged storage intervals up to 48 h. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Functional Role of HSP47 in the Periodontal Ligament Subjected to Occlusal Overload in Mice.

PubMed

Mimura, Hiroaki; Takaya, Tatsuo; Matsuda, Saeka; Nakano, Keisuke; Muraoka, Rina; Tomida, Mihoko; Okafuji, Norimasa; Fujii, Takeo; Kawakami, Toshiyuki

2016-01-01

We carried out an experiment to induce traumatic occlusion in mice periodontal tissue and analyzed the expression of HSP47. Continuous traumatic occlusion resulted to damage and remodeling of periodontal ligament as well as increase in osteoclasts and bone resorption. Four days after traumatic occlusion, osteoclasts did not increase but Howship's lacunae became enlarged. That is, the persistent occlusal overload can destroy collagen fibers in the periodontal ligament. This was evident by the increased in HSP47 expression with the occlusal overload. HSP47 is maintained in fibroblasts for repair of damaged collagen fibers. On the other hand, osteoclasts continue to increase although the load was released. The osteoclasts that appeared on the alveolar bone surface were likely due to sustained activity. The increase in osteoclasts was estimated to occur after load application at day 4. HSP47 continued to increase until day 6 in experiment 2 but then reduced at day 10. Therefore, HSP47 appears after a period of certain activities to repair damaged collagen fibers, and the activity was returned to a state of equilibrium at day 30 with significantly diminished expression. Thus, the results suggest that HSP47 is actively involved in homeostasis of periodontal tissue subjected to occlusal overload.

Molecular cloning, expression and immunolocalization of a novel human cementum-derived protein (CP-23).

PubMed

Alvarez-Pérez, Marco Antonio; Narayanan, Sampath; Zeichner-David, Margarita; Rodríguez Carmona, Bruno; Arzate, Higinio

2006-03-01

Cementum is a unique mineralized connective tissue that covers the root surfaces of the teeth. The cementum is critical for appropriate maturation of the periodontium, both during development as well as that associated with regeneration of periodontal tissues, IU; however, one major impediment to understand the molecular mechanisms that regulate periodontal regeneration is the lack of cementum markers. Here we report on the identification and characterization of one such differentially human expressed gene, termed "cementum protein-23" (CP-23) that appears to be periodontal ligament and cementum-specific. We screened human cementum tumor-derived cDNA libraries by transient expression in COS-7 cells and "panning" with a rabbit polyclonal antibody against a cementoblastoma conditioned media-derived protein (CP). One isolated cDNA, CP-23, was expressed in E. coli and polyclonal antibodies against the recombinant human CP-23 were produced. Expression of CP-23 protein by cells of the periodontium was examined by Northern blot and in situ hybridization. Expression of CP-23 transcripts in human cementoblastoma-derived cells, periodontal ligament cells, human gingival fibroblasts and alveolar bone-derived cells was determined by RT-PCR. Our results show that we have isolated a 1374-bp human cDNA containing an open reading frame that encodes a polypeptide with 247 amino acid residues, with a predicted molecular mass of 25.9 kDa that represents CP species. The recombinant human CP-23 protein cross-reacted with antibodies against CP and type X collagen. Immunoscreening of human periodontal tissues revealed that CP-23 gene product is localized to the cementoid matrix of cementum and cementoblasts throughout the entire surface of the root, cell subpopulations of the periodontal ligament as well as cells located paravascularly to the blood vessels into the periodontal ligament. Furthermore, 98% of putative cementoblasts and 15% of periodontal ligament cells cultured in vitro expressed CP-23 gene product. Cementoblastoma cells and periodontal ligament cells contained a 5.0 kb CP-23 mRNA. In situ hybridization showed strong expression of CP-23 mRNA on cementoblast, cell subpopulations of the periodontal ligament and cells located around blood vessels into the periodontal ligament. Our results demonstrate that CP-23 represents a novel, tissue-specific-gene product being expressed by periodontal ligament subpopulations and cementoblasts. These findings offer the possibility to determine the cellular and molecular events that regulate the cementogenesis process during root development. Furthermore, it might provide new venues for the design of translational studies aimed at achieving predictable new cementogenesis and regeneration of the periodontal tissues.

Test of Surfactant-Based Dermal Wound Cleansers on Sulfur Mustard-Exposed Human Keratinocytes in an In Vitro Wound Healing Model

DTIC Science & Technology

2008-11-01

21. Chuang AH, Runner R, Lapp C , Bhatt B, McPherson, III, JC. The effect of Pluronic F-68 on wound healing of periodontal ligament fibroblasts in low alcohol conditions. Ga J Sci 2005; 63:74. ...PAGES 19a. NAME OF RESPONSIBLE PERSON Claudia L. Henemyre-Harris a. REPORT UNCLASSIFIED b. ABSTRACT UNCLASSIFIED c . THIS PAGE UNCLASSIFIED...8217-dichlorodiethyl sulfide) reacts with nucleophilic sites such as DNA, proteins , and membrane components, and several mechanisms for damage have been suggested.1

Tumor-produced, active Interleukin-1 {beta} regulates gene expression in carcinoma-associated fibroblasts

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

Dudas, Jozsef, E-mail: Jozsef.Dudas@i-med.ac.at; Fullar, Alexandra, E-mail: fullarsz@gmail.com; 1st Institute of Pathology and Experimental Cancer Research, Semmelweis University, Ulloei ut 26, H-1085 Budapest

2011-09-10

Recently we described a co-culture model of periodontal ligament (PDL) fibroblasts and SCC-25 lingual squamous carcinoma cells, which resulted in conversion of normal fibroblasts into carcinoma-associated fibroblasts (CAFs), and in epithelial-mesenchymal transition (EMT) of SCC-25 cells. We have found a constitutive high interleukin-1{beta} (IL1-{beta}) expression in SCC-25 cells in normal and in co-cultured conditions. In our hypothesis a constitutive IL1-{beta} expression in SCC-25 regulates gene expression in fibroblasts during co-culture. Co-cultures were performed between PDL fibroblasts and SCC-25 cells with and without dexamethasone (DEX) treatment; IL1-{beta} processing was investigated in SCC-25 cells, tumor cells and PDL fibroblasts were treated withmore » IL1-{beta}. IL1-{beta} signaling was investigated by western blot and immunocytochemistry. IL1-{beta}-regulated genes were analyzed by real-time qPCR. SCC-25 cells produced 16 kD active IL1-{beta}, its receptor was upregulated in PDL fibroblasts during co-culture, which induced phosphorylation of interleukin-1 receptor-associated kinase-1 (IRAK-1), and nuclear translocalization of NF{kappa}B{alpha}. Several genes, including interferon regulatory factor 1 (IRF1) interleukin-6 (IL-6) and prostaglandin-endoperoxide synthase 2 (COX-2) were induced in CAFs during co-culture. The most enhanced induction was found for IL-6 and COX-2. Treatment of PDL fibroblasts with IL1-{beta} reproduced a time- and dose-dependent upregulation of IL1-receptor, IL-6 and COX-2. A further proof was achieved by DEX inhibition for IL1-{beta}-stimulated IL-6 and COX-2 gene expression. Constitutive expression of IL1-{beta} in the tumor cells leads to IL1-{beta}-stimulated gene expression changes in tumor-associated fibroblasts, which are involved in tumor progression. -- Graphical abstract: SCC-25 cells produce active, processed IL1-{beta}. PDL fibroblasts possess receptor for IL1-{beta}, and its expression is increased 4.56-times in the presence of SCC-25 tumor cells. IL1-{beta} receptor expression in fibroblasts, especially in CAFs represents a major option in coordination of fibroblast and tumor behavior. A key event in IL1-{beta} signaling, the phosphorylation of IRAK1, occurred in co-cultured fibroblasts, which has lead to nuclear translocation of NF{kappa}B{alpha}, and finally to induction of several genes, including BDNF, IRF1, IL-6 and COX-2. The most enhanced induction was found for IL-6 and COX-2.« less

In vitro reconstruction of human junctional and sulcular epithelium

PubMed Central

Dabija-Wolter, G; Bakken, V; Cimpan, M R; Johannessen, A C; Costea, D E

2013-01-01

BACKGROUND The aim of this study was to develop and characterize standardized in vitro three-dimensional organotypic models of human junctional epithelium (JE) and sulcular epithelium (SE). METHODS Organotypic models were constructed by growing human normal gingival keratinocytes on top of collagen matrices populated with gingival fibroblasts (GF) or periodontal ligament fibroblasts (PLF). Tissues obtained were harvested at different time points and assessed for epithelial morphology, proliferation (Ki67), expression of JE-specific markers (ODAM and FDC-SP), cytokeratins (CK), transglutaminase, filaggrin, and basement membrane proteins (collagen IV and laminin1). RESULTS The epithelial component in 3- and 5-day organotypics showed limited differentiation and expressed Ki-67, ODAM, FDC-SP, CK 8, 13, 16, 19, and transglutaminase in a similar fashion to control JE samples. PLF supported better than GF expression of CK19 and suprabasal proliferation, although statistically significant only at day 5. Basement membrane proteins started to be deposited only from day 5. The rate of proliferating cells as well as the percentage of CK19-expressing cells decreased significantly in 7- and 9-day cultures. Day 7 organotypics presented higher number of epithelial cell layers, proliferating cells in suprabasal layers, and CK expression pattern similar to SE. CONCLUSION Both time in culture and fibroblast type had impact on epithelial phenotype. Five-day cultures with PLF are suggested as JE models, 7-day cultures with PLF or GF as SE models, while 9-day cultures with GF as gingival epithelium (GE) models. Such standard, reproducible models represent useful tools to study periodontal bacteria–host interactions in vitro. PMID:22947066

Generation of stem cell-based bioartificial anterior cruciate ligament (ACL) grafts for effective ACL rupture repair.

PubMed

Kouroupis, Dimitrios; Kyrkou, Athena; Triantafyllidi, Eleni; Katsimpoulas, Michalis; Chalepakis, George; Goussia, Anna; Georgoulis, Anastasios; Murphy, Carol; Fotsis, Theodore

2016-09-01

In the present study, we combined stem cell technology with a non-absorbable biomaterial for the reconstruction of the ruptured ACL. Towards this purpose, multipotential stromal cells derived either from subcutaneous human adipose tissue (hAT-MSCs) or from induced pluripotent stem cells (iPSCs) generated from human foreskin fibroblasts (hiPSC-MSCs) were cultured on the biomaterial for 21days in vitro to generate a 3D bioartifical ACL graft. Stem cell differentiation towards bone and ligament at the ends and central part of the biomaterial was selectively induced using either BMP-2/FGF-2 or TGF-β/FGF-2 combinations, respectively. The bioartificial ACL graft was subsequently implanted in a swine ACL rupture model in place of the surgically removed normal ACL. Four months post-implantation, the tissue engineered ACL graft generated an ACL-like tissue exhibiting morphological and biochemical characteristics resembling those of normal ACL. Copyright © 2016 Helmholtz Zentrum München. Published by Elsevier B.V. All rights reserved.

The effects of plasma rich in growth factors (PRGF-Endoret) on healing of medial collateral ligament of the knee.

PubMed

Yoshioka, Tomokazu; Kanamori, Akihiro; Washio, Toshikatsu; Aoto, Katsuya; Uemura, Kenta; Sakane, Masataka; Ochiai, Naoyuki

2013-08-01

Platelet-rich plasma (PRP) has been increasingly used in sports-related injuries for therapeutic applications. However, there are numerous manufacturing procedures and treatment protocols of PRP use, which make difficult to assess its real efficacy for tissue healing. This study addressed to evaluate the therapeutic effects of locally delivered plasma rich in growth factors (PRGF-Endoret) on the early healing of medial collateral ligament (MCL) in rabbit knees. Thirty-one Japanese white rabbits were subjected to a mop-end tear in the MCL of the left knee. PRGF-Endoret was prepared using Anitua's technique. Two groups were set up. In 17 knees, prepared 1.0 ml of PRGF-Endoret after clotting was applied on the tear site, while in 14 knees the tear site was untreated serving as a control. Quantitative aspects of PRGF-Endoret, the concentration of platelets, leukocytes and erythrocytes and therapeutic growth factors such as PDGF-BB and TGF-β1 were measured. Rabbits were sacrificed at 3 and 6 weeks after the operation and histological and biomechanical evaluation were performed. No leukocytes were measured and certain amount of growth factors such as PDGF-BB and TGF-β1 were confirmed in the PRGF-Endoret. PRGF-Endoret stimulated proliferation of fibroblasts and neovascularization, and induced statistically better structural properties in repaired MCL. Our findings provide evidence that local administration of PRGF-Endoret promotes early steps in ligament healing and the repair of structural properties in a rabbit model. PRGF-Endoret would be a useful product in clinical treatment of ligament injuries.

Histological analysis of the structural composition of ankle ligaments.

PubMed

Rein, Susanne; Hagert, Elisabet; Schneiders, Wolfgang; Fieguth, Armin; Zwipp, Hans

2015-02-01

Various ankle ligaments have different structural composition. The aim of this study was to analyze the morphological structure of ankle ligaments to further understand their function in ankle stability. One hundred forty ligaments from 10 fresh-frozen cadaver ankle joints were dissected: the calcaneofibular, anterior, and posterior talofibular ligaments; the inferior extensor retinaculum, the talocalcaneal oblique ligament, the canalis tarsi ligament; the deltoid ligament; and the anterior tibiofibular ligament. Hematoxylin-eosin and Elastica van Gieson stains were used for determination of tissue morphology. Three different morphological compositions were identified: dense, mixed, and interlaced compositions. Densely packed ligaments, characterized by parallel bundles of collagen, were primarily seen in the lateral region, the canalis tarsi, and the anterior tibiofibular ligaments. Ligaments with mixed tight and loose parallel bundles of collagenous connective tissue were mainly found in the inferior extensor retinaculum and talocalcaneal oblique ligament. Densely packed and fiber-rich interlacing collagen was primarily seen in the areas of ligament insertion into bone of the deltoid ligament. Ligaments of the lateral region, the canalis tarsi, and the anterior tibiofibular ligaments have tightly packed, parallel collagen bundles and thus can resist high tensile forces. The mixed tight and loose, parallel oriented collagenous connective tissue of the inferior extensor retinaculum and the talocalcaneal oblique ligament support the dynamic positioning of the foot on the ground. The interlacing collagen bundles seen at the insertion of the deltoid ligament suggest that these insertion areas are susceptible to tension in a multitude of directions. The morphology and mechanical properties of ankle ligaments may provide an understanding of their response to the loads to which they are subjected. © The Author(s) 2015.

Anterior Cruciate Ligament Reconstruction in a Rabbit Model Using Silk-Collagen Scaffold and Comparison with Autograft

PubMed Central

Bi, Fanggang; Shi, Zhongli; Liu, An; Guo, Peng; Yan, Shigui

2015-01-01

The objective of the present study was to perform an in vivo assessment of a novel silk-collagen scaffold for anterior cruciate ligament (ACL) reconstruction. First, a silk-collagen scaffold was fabricated by combining sericin-extracted knitted silk fibroin mesh and type I collagen to mimic the components of the ligament. Scaffolds were electron-beam sterilized and rolled up to replace the ACL in 20 rabbits in the scaffold group, and autologous semitendinosus tendons were used to reconstruct the ACL in the autograft control group. At 4 and 16 weeks after surgery, grafts were retrieved and analyzed for neoligament regeneration and tendon-bone healing. To evaluate neoligament regeneration, H&E and immunohistochemical staining was performed, and to assess tendon-bone healing, micro-CT, biomechanical test, H&E and Russell-Movat pentachrome staining were performed. Cell infiltration increased over time in the scaffold group, and abundant fibroblast-like cells were found in the core of the scaffold graft at 16 weeks postoperatively. Tenascin-C was strongly positive in newly regenerated tissue at 4 and 16 weeks postoperatively in the scaffold group, similar to observations in the autograft group. Compared with the autograft group, tendon-bone healing was better in the scaffold group with trabecular bone growth into the scaffold. The results indicate that the silk-collagen scaffold has considerable potential for clinical application. PMID:25938408

Interleukin Expression after Injury and the Effects of Interleukin-1 Receptor Antagonist

PubMed Central

Chamberlain, Connie S.; Leiferman, Ellen M.; Frisch, Kayt E.; Brickson, Stacey L.; Murphy, William L.; Baer, Geoffrey S.; Vanderby, Ray

2013-01-01

Ligament healing follows a series of complex coordinated events involving various cell types, cytokines, as well as other factors, producing a mechanically inferior tissue more scar-like than native tissue. Macrophages provide an ongoing source of cytokines to modulate inflammatory cell adhesion and migration as well as fibroblast proliferation. Studying interleukins inherent to ligament healing during peak macrophage activation and angiogenesis may elucidate inflammatory mediators involved in subsequent scar formation. Herein, we used a rat healing model assayed after surgical transection of their medial collateral ligaments (MCLs). On days 3 and 7 post-injury, ligaments were collected and used for microarray analysis. Of the 12 significantly modified interleukins, components of the interleukin-1 family were significantly up-regulated. We therefore examined the influence of interleukin-1 receptor antagonist (IL-1Ra) on MCL healing. Transected rat MCLs received PBS or IL-1Ra at the time of surgery. Inhibition of IL-1 activation decreased pro-inflammatory cytokines (IL-1α, IL-1β, IL-12, IL-2, and IFN-γ), myofibroblasts, and proliferating cells, as well as increased anti-inflammatory cytokines (IL-10), endothelial cells/blood vessel lumen, M2 macrophages, and granulation tissue size without compromising the mechanical properties. These results support the concept that IL-1Ra modulates MCL-localized granulation tissue components and cytokine production to create a transient environment that is less inflammatory. Overall, IL-1Ra may have therapeutic potential early in the healing cascade by stimulating the M2 macrophages and altering the granulation tissue components. However, the single dose of IL-1Ra used in this study was insufficient to maintain the more regenerative early response. Due to the transient influence on most of the healing components tested, IL-1Ra may have greater therapeutic potential with sustained delivery. PMID:23936523

Engineering an in vitro model of a functional ligament from bone to bone.

PubMed

Paxton, Jennifer Z; Grover, Liam M; Baar, Keith

2010-11-01

For musculoskeletal tissues that transmit loads during movement, the interfaces between tissues are essential to minimizing injury. Therefore, the reproduction of functional interfaces within engineered musculoskeletal tissues is critical to the successful transfer of the technology to the clinic. The goal of this work was to rapidly engineer ligament equivalents in vitro that contained both the soft tissue sinew and a hard tissue bone mimetic. This goal was achieved using cast brushite (CaHPO(4)·2H(2)O) anchors to mimic bone and a fibrin gel embedded with fibroblasts to create the sinew. The constructs formed within 7 days. Fourteen days after seeding, the interface between the brushite and sinew could withstand a stress of 9.51 ± 1.7  kPa before failure and the sinew reached a Young's modulus value of 0.16 ± 0.03  MPa. Treatment with ascorbic acid and proline increased the collagen content of the sinew (from 1.34% ± 0.2% to 8.34% ± 0.37%), strength of the interface (29.24 ± 6  kPa), and modulus of the sinew (2.69 ± 0.25  MPa). Adding transforming growth factor-β resulted in a further increase in collagen (11.25% ± 0.39%), interface strength (42 ± 8  kPa), and sinew modulus (5.46 ± 0.68  MPa). Both scanning electron and Raman microscopy suggested that the interface between the brushite and sinew mimics the in vivo tidemark at the enthesis. This work describes a major step toward the development of tissue-engineered ligaments for the repair of ligament ruptures in humans.

Comparative transcriptional analysis of three human ligaments with distinct biomechanical properties

PubMed Central

Lorda-Diez, Carlos I; Canga-Villegas, Ana; Cerezal, Luis; Plaza, Santiago; Hurlé, Juan M; García-Porrero, Juan A; Montero, Juan A

2013-01-01

One major aim of regenerative medicine targeting the musculoskeletal system is to provide complementary and/or alternative therapeutic approaches to current surgical therapies, often involving the removal and prosthetic substitution of damaged tissues such as ligaments. For these approaches to be successful, detailed information regarding the cellular and molecular composition of different musculoskeletal tissues is required. Ligaments have often been considered homogeneous tissues with common biomechanical properties. However, advances in tissue engineering research have highlighted the functional relevance of the organisational and compositional differences between ligament types, especially in those with higher risks of injury. The aim of this study was to provide information concerning the relative expression levels of a subset of key genes (including extracellular matrix components, transcription factors and growth factors) that confer functional identity to ligaments. We compared the transcriptomes of three representative human ligaments subjected to different biomechanical demands: the anterior cruciate ligament (ACL); the ligamentum teres of the hip (LT); and the iliofemoral ligament (IL). We revealed significant differences in the expression of type I collagen, elastin, fibromodulin, biglycan, transforming growth factor β1, transforming growth interacting factor 1, hypoxia-inducible factor 1-alpha and transforming growth factor β-induced gene between the IL and the other two ligaments. Thus, considerable molecular heterogeneity can exist between anatomically distinct ligaments with differing biomechanical demands. However, the LT and ACL were found to show remarkable molecular homology, suggesting common functional properties. This finding provides experimental support for the proposed role of the LT as a hip joint stabiliser in humans. PMID:24128114

Conditioned Medium from Periodontal Ligament Stem Cells Enhances Periodontal Regeneration.

PubMed

Nagata, Mizuki; Iwasaki, Kengo; Akazawa, Keiko; Komaki, Motohiro; Yokoyama, Naoki; Izumi, Yuichi; Morita, Ikuo

2017-05-01

Periodontal disease is one of the most common infectious diseases in adults and is characterized by the destruction of tooth-supporting tissues. Mesenchymal stem cells (MSCs) comprise the mesoderm-originating stem cell population, which has been studied and used for cell therapy. However, because of the lower rate of cell survival after MSC transplantation in various disease models, paracrine functions of MSCs have been receiving increased attention as a regenerative mechanism. The aim of this study was to investigate the regenerative potential of transplanted conditioned medium (CM) obtained from cultured periodontal ligament stem cells (PDLSCs), the adult stem cell population in tooth-supporting tissues, using a rat periodontal defect model. Cell-free CM was collected from PDLSCs and fibroblasts, using ultrafiltration and transplanted into surgically created periodontal defects. Protein content of CM was examined by antibody arrays. Formation of new periodontal tissues was analyzed using microcomputed tomography and histological sections. PDLSC-CM transplantation enhanced periodontal tissue regeneration in a concentration-dependent manner, whereas fibroblast-CM did not show any regenerative function. Proteomic analysis revealed that extracellular matrix proteins, enzymes, angiogenic factors, growth factors and cytokines were contained in PDLSC-CM. Furthermore, PDLSC-CM transplantation resulted in the decreased mRNA level of tumor necrosis factor-α (TNF-α) in healing periodontal tissues. In addition, we found that PDLSC-CM suppressed the mRNA level of TNF-α in the monocyte/macrophage cell line, RAW cells, stimulated with IFN-γ. Our findings suggested that PDLSC-CM enhanced periodontal regeneration by suppressing the inflammatory response through TNF-α production, and transplantation of PDLSC-CM could be a novel approach for periodontal regenerative therapy.

Angiogenic Capacity of Periodontal Ligament Stem Cells Pretreated with Deferoxamine and/or Fibroblast Growth Factor-2

PubMed Central

Ratajczak, Jessica; Hilkens, Petra; Gervois, Pascal; Wolfs, Esther; Jacobs, Reinhilde; Lambrichts, Ivo; Bronckaers, Annelies

2016-01-01

Periodontal ligament stem cells (PDLSCs) represent a good source of multipotent cells for cell-based therapies in regenerative medicine. The success rate of these treatments is severely dependent on the establishment of adequate vasculature in order to provide oxygen and nutrients to the transplanted cells. Pharmacological preconditioning of stem cells has been proposed as a promising method to augment their therapeutic efficacy. In this study, the aim was to improve the intrinsic angiogenic properties of PDLSCs by in vitro pretreatment with deferoxamine (DFX; 100μM), fibroblast growth factor-2 (FGF-2; 10ng/mL) or both substances combined. An antibody array revealed the differential expression of several proteins, including vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). ELISA data confirmed a 1.5 to 1.8-fold increase in VEGF for all tested conditions. Moreover, 48 hours after the removal of DFX, VEGF levels remained elevated (1.8-fold) compared to control conditions. FGF-2 and combination treatment resulted in a 5.4 to 13.1-fold increase in PlGF secretion, whereas DFX treatment had no effect. Furthermore, both PDLSCs as pretreated PDLSCs induced endothelial migration. Despite the significant elevated VEGF levels of pretreated PDLSCs, the induced endothelial migration was not higher by pretreated PDLSCs. We find that the observed induced endothelial cell motility was not dependent on VEGF, since blocking the VEGFR1-3 with Axitinib (0.5nM) did not inhibit endothelial motility towards PDLSCs. Taken together, this study provides evidence that preconditioning with DFX and/or FGF-2 significantly improves the angiogenic secretome of PDLSCs, in particular VEGF and PlGF secretion. However, our data suggest that VEGF is not the only player when it comes to influencing endothelial behavior by the PDLSCs. PMID:27936076

Conditioned Medium from Periodontal Ligament Stem Cells Enhances Periodontal Regeneration

PubMed Central

Nagata, Mizuki; Akazawa, Keiko; Komaki, Motohiro; Yokoyama, Naoki; Izumi, Yuichi; Morita, Ikuo

2017-01-01

Periodontal disease is one of the most common infectious diseases in adults and is characterized by the destruction of tooth-supporting tissues. Mesenchymal stem cells (MSCs) comprise the mesoderm-originating stem cell population, which has been studied and used for cell therapy. However, because of the lower rate of cell survival after MSC transplantation in various disease models, paracrine functions of MSCs have been receiving increased attention as a regenerative mechanism. The aim of this study was to investigate the regenerative potential of transplanted conditioned medium (CM) obtained from cultured periodontal ligament stem cells (PDLSCs), the adult stem cell population in tooth-supporting tissues, using a rat periodontal defect model. Cell-free CM was collected from PDLSCs and fibroblasts, using ultrafiltration and transplanted into surgically created periodontal defects. Protein content of CM was examined by antibody arrays. Formation of new periodontal tissues was analyzed using microcomputed tomography and histological sections. PDLSC-CM transplantation enhanced periodontal tissue regeneration in a concentration-dependent manner, whereas fibroblast-CM did not show any regenerative function. Proteomic analysis revealed that extracellular matrix proteins, enzymes, angiogenic factors, growth factors and cytokines were contained in PDLSC-CM. Furthermore, PDLSC-CM transplantation resulted in the decreased mRNA level of tumor necrosis factor-α (TNF-α) in healing periodontal tissues. In addition, we found that PDLSC-CM suppressed the mRNA level of TNF-α in the monocyte/macrophage cell line, RAW cells, stimulated with IFN-γ. Our findings suggested that PDLSC-CM enhanced periodontal regeneration by suppressing the inflammatory response through TNF-α production, and transplantation of PDLSC-CM could be a novel approach for periodontal regenerative therapy. PMID:28027709

Effect of temperature and seven storage media on human periodontal ligament fibroblast viability.

PubMed

de Souza, Beatriz Dulcineia Mendes; Bortoluzzi, Eduardo Antunes; Reyes-Carmona, Jessie; Dos Santos, Luciane Geanini Pena; Simões, Claudia Maria de Oliveira; Felippe, Wilson Tadeu; Felippe, Mara Cristina Santos

2017-04-01

Natural resources, such as coconut water, propolis, and egg whites, have been examined as possible storage media for avulsed teeth. However, there is a lack of research focused on the efficacy of these three products together compared with Hank's balanced salt solution and milk. The aim of this study was to evaluate the capacity of seven storage media to maintain the viability of human periodontal ligament fibroblasts (PDLFs). PDLFs were kept at 5°C and 20°C, in skimmed milk (SMilk), whole milk (WMilk), recently prepared Hank's balanced salt solution (HBSS), Save-A-Tooth ® system's HBSS (Save), natural coconut water (Coconut), Propolis, and egg white (Egg) for 3, 6, 24, 48, 72, 96, and 120 h, through the analysis of tetrazolium salt-based colorimetric (MTT) assay. At 5°C, SMilk and WMilk were better than HBSS in maintaining cell viability, from 24 h onward. At 20°C, HBSS was the best storage medium at 96 and 120 h. At both temperatures, from 6 h onward, Coconut, Propolis and Egg were less effective than SMilk, WMilk, and HBSS. In general, the performance of Coconut, Propolis and Egg were not influenced by storage temperature. However, the lowest temperature undermined the effectiveness of HBSS from 24 h and favored SMilk and WMilk, from 96 and 48 h onward, respectively. Save and water were the worst storage media. SMilk was the best storage medium, followed by WMilk and HBSS. Coconut, Propolis, and Egg can be indicated for the conservation of PDLF up to 3 h. The lower temperature (5°C) undermined the effectiveness of HBSS and favored SMilk and WMilk. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Genistein regulates the IL-1 beta induced activation of MAPKs in human periodontal ligament cells through G protein-coupled receptor 30.

PubMed

Luo, Li-Jun; Liu, Feng; Lin, Zhi-Kai; Xie, Yu-Feng; Xu, Jia-Li; Tong, Qing-Chun; Shu, Rong

2012-06-01

Periodontal ligament (PDL) cells are fibroblasts that play key roles in tissue integrity, periodontal inflammation and tissue regeneration in the periodontium. The periodontal tissue destruction in periodontitis is mediated by host tissue-produced inflammatory cytokines, including interleukin-1β (IL-1β). Here, we report the expression of G protein-coupled receptor 30 (GPR30, also known as G protein-coupled estrogen receptor 1 GPER) in human PDL cells and its regulation by IL-1β. IL-1β-induced GPR30 expression in human PDL cells leads to the activation of multiple signaling pathways, including MAPK, NF-κB and PI3K. In contrast, genistein, an estrogen receptor ligand, postpones the activation of MAPKs induced by IL-1β. Moreover, the inhibition of GPR30 by G15, a GPR30-specific antagonist, eliminates this delay. Thus, genistein plays a role in the regulation of MAPK activation via GPR30, and GPR30 represents a novel target regulated by steroid hormones in PDL cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Preliminary investigation of airgap electrospun silk-fibroin-based structures for ligament analogue engineering.

PubMed

Sell, S A; McClure, M J; Ayres, C E; Simpson, D G; Bowlin, G L

2011-01-01

The process of electrospinning has proven to be highly beneficial for use in a number of tissue-engineering applications due to its ease of use, flexibility and tailorable properties. There have been many publications on the creation of aligned fibrous structures created through various forms of electrospinning, most involving the use of a metal target rotating at high speeds. This work focuses on the use of a variation known as airgap electrospinning, which does not use a metal collecting target but rather a pair of grounded electrodes equidistant from the charged polymer solution to create highly aligned 3D structures. This study involved a preliminary investigation and comparison of traditionally and airgap electrospun silk-fibroin-based ligament constructs. Structures were characterized with SEM and alignment FFT, and underwent porosity, permeability, and mechanical anisotropy evaluation. Preliminary cell culture with human dermal fibroblasts was performed to determine the degree of cellular orientation and penetration. Results showed airgap electrospun structures to be anisotropic with significantly increased porosity and cellular penetration compared to their traditionally electrospun counterparts.

Sonography of the anterior oblique ligament of the trapeziometacarpal joint: a study of cadavers and asymptomatic volunteers.

PubMed

Chiavaras, Mary M; Harish, Srinivasan; Oomen, Glen; Popowich, Terry; Wainman, Bruce; Bain, James R

2010-12-01

The purpose of this study was to evaluate the ability of ultrasound to identify and characterize the anterior oblique ligament of the thumb in cadavers and asymptomatic volunteers. The anterior oblique ligaments of four cadaveric hands were imaged with a high-resolution transducer. The ligaments were then injected with 0.1% methylene blue using ultrasound guidance. To confirm identification of the ligament, the base of the thumb was immediately dissected, revealing the exact location of the dye. The bilateral ligaments in 40 asymptomatic adult volunteers were imaged. Surgical dissection confirmed injection of methylene blue into all cadaveric ligaments. The proximal attachment of the anterior oblique ligament was well defined in all the hands, and the distal attachment was well defined in 94% of the hands. The mean thickness of the anterior oblique ligament at the metacarpal attachment (0.7 mm), midportion (0.98 mm), and trapezial attachment (0.65 mm) did not differ significantly with respect to sex, right and left side, or hand dominance and was weakly correlated with weight, height, body mass index, and age. The length of the ligament was statistically significantly different between the dominant (10.6 mm) and nondominant (9.6 mm) hands. The volar metacarpal translation with palmar abduction stress did not differ significantly between the dominant (0.7 mm) and nondominant (0.8 mm) hands. There was no association between the degree of translation and the biologic characteristics (weight, height, body mass index, and age). High-resolution ultrasound can be used to identify and measure the thickness of the anterior oblique ligament. Dynamic ultrasound imaging can depict volar translation of the metacarpal, which may facilitate diagnosis of ligamentous injury.

A Quantitative Study of the Relationship between the Distribution of Different Types of Collagen and the Mechanical Behavior of Rabbit Medial Collateral Ligaments

PubMed Central

Wan, Chao; Hao, Zhixiu; Wen, Shizhu; Leng, Huijie

2014-01-01

The mechanical properties of ligaments are key contributors to the stability and function of musculoskeletal joints. Ligaments are generally composed of ground substance, collagen (mainly type I and III collagen), and minimal elastin fibers. However, no consensus has been reached about whether the distribution of different types of collagen correlates with the mechanical behaviors of ligaments. The main objective of this study was to determine whether the collagen type distribution is correlated with the mechanical properties of ligaments. Using axial tensile tests and picrosirius red staining-polarization observations, the mechanical behaviors and the ratios of the various types of collagen were investigated for twenty-four rabbit medial collateral ligaments from twenty-four rabbits of different ages, respectively. One-way analysis of variance was used in the comparison of the Young's modulus in the linear region of the stress-strain curves and the ratios of type I and III collagen for the specimens (the mid-substance specimens of the ligaments) with different ages. A multiple linear regression was performed using the collagen contents (the ratios of type I and III collagen) and the Young's modulus of the specimens. During the maturation of the ligaments, the type I collagen content increased, and the type III collagen content decreased. A significant and strong correlation () was identified by multiple linear regression between the collagen contents (i.e., the ratios of type I and type III collagen) and the mechanical properties of the specimens. The collagen content of ligaments might provide a new perspective for evaluating the linear modulus of global stress-strain curves for ligaments and open a new door for studying the mechanical behaviors and functions of connective tissues. PMID:25062068

A quantitative study of the relationship between the distribution of different types of collagen and the mechanical behavior of rabbit medial collateral ligaments.

PubMed

Wan, Chao; Hao, Zhixiu; Wen, Shizhu; Leng, Huijie

2014-01-01

The mechanical properties of ligaments are key contributors to the stability and function of musculoskeletal joints. Ligaments are generally composed of ground substance, collagen (mainly type I and III collagen), and minimal elastin fibers. However, no consensus has been reached about whether the distribution of different types of collagen correlates with the mechanical behaviors of ligaments. The main objective of this study was to determine whether the collagen type distribution is correlated with the mechanical properties of ligaments. Using axial tensile tests and picrosirius red staining-polarization observations, the mechanical behaviors and the ratios of the various types of collagen were investigated for twenty-four rabbit medial collateral ligaments from twenty-four rabbits of different ages, respectively. One-way analysis of variance was used in the comparison of the Young's modulus in the linear region of the stress-strain curves and the ratios of type I and III collagen for the specimens (the mid-substance specimens of the ligaments) with different ages. A multiple linear regression was performed using the collagen contents (the ratios of type I and III collagen) and the Young's modulus of the specimens. During the maturation of the ligaments, the type I collagen content increased, and the type III collagen content decreased. A significant and strong correlation (R2 = 0.839, P < 0.05) was identified by multiple linear regression between the collagen contents (i.e., the ratios of type I and type III collagen) and the mechanical properties of the specimens. The collagen content of ligaments might provide a new perspective for evaluating the linear modulus of global stress-strain curves for ligaments and open a new door for studying the mechanical behaviors and functions of connective tissues.

Thoracolumbar spinal ligaments exhibit negative and transverse pre-strain.

PubMed

Robertson, Daniel J; Von Forell, Gregory A; Alsup, Jeremy; Bowden, Anton E

2013-07-01

The present work represents the first reported bi-axial spinal ligament pre-strain data for the thoracic and lumbar spine. Ligament pre-strain (in-situ strain) is known to significantly alter joint biomechanics. However, there is currently a lack of comprehensive data with regards to spinal ligament pre-strain. The current work determined the pre-strain of 71 spinal ligaments (30 anterior longitudinal ligaments, 27 supraspinous ligaments and 14 interspinous ligaments). The interspinous ligament and the anterior longitudinal ligament exhibited bi-axial pre-strain distributions, demonstrating they are not uniaxial structures. The supraspinous ligament frequently exhibited large amounts of negative pre-strain or laxity suggesting it makes no mechanical contribution to spinal stability near the neutral posture. Upon implementing multi-axial pre-strain results into a finite element model of the lumbar spine, large differences in spinal biomechanics were observed. These results demonstrate the necessity of accounting for ligament pre-strain in biomechanical models. In addition, the authors present a unique experimental method for obtaining ligament pre-strain that presents a number of advantages when compared to standard techniques. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of Different Angles of the Traction Table on Lumbar Spine Ligaments: A Finite Element Study.

PubMed

Farajpour, Hekmat; Jamshidi, Nima

2017-12-01

The traction bed is a noninvasive device for treating lower back pain caused by herniated intervertebral discs. In this study, we investigated the impact of the traction bed on the lower back as a means of increasing the disc height and creating a gap between facet joints. Computed tomography (CT) images were obtained from a female volunteer and a three-dimensional (3D) model was created using software package MIMICs 17.0. Afterwards, the 3D model was analyzed in an analytical software (Abaqus 6.14). The study was conducted under the following traction loads: 25%, 45%, 55%, and 85% of the whole body weight in different angles. Results indicated that the loading angle in the L3-4 area had 36.8%, 57.4%, 55.32%, 49.8%, and 52.15% effect on the anterior longitudinal ligament, posterior longitudinal ligament, intertransverse ligament, interspinous ligament, and supraspinous ligament, respectively. The respective values for the L4-5 area were 32.3%, 10.6%, 53.4%, 56.58%, and 57.35%. Also, the body weight had 63.2%, 42.6%, 44.68%, 50.2%, and 47.85% effect on the anterior longitudinal ligament, posterior longitudinal ligament, intertransverse ligament, interspinous ligament, and supraspinous ligament, respectively. The respective values for the L4-5 area were 67.7%, 89.4%, 46.6%, 43.42% and 42.65%. The authenticity of results was checked by comparing with the experimental data. The results show that traction beds are highly effective for disc movement and lower back pain relief. Also, an optimal angle for traction can be obtained in a 3D model analysis using CT or magnetic resonance imaging images. The optimal angle would be different for different patients and thus should be determined based on the decreased height of the intervertebral disc, weight and height of patients.

Analysis of radiopacity, pH and cytotoxicity of a new bioceramic material.

PubMed

Souza, Letícia Chaves de; Yadlapati, Mamatha; Dorn, Samuel O; Silva, Renato; Letra, Ariadne

2015-01-01

RetroMTA® is a new hydraulic bioceramic indicated for pulp capping, perforations or root resorption repair, apexification and apical surgery. The aim of this study was to compare the radiopacity, pH variation and cytotoxicity of this material to ProRoot® MTA. Mixed cements were exposed to a digital x-ray along with an aluminum stepwedge for the radiopacity assay. pH values were verified after incubation period of 3, 24, 48, 72 and 168 hours. The cytotoxicity of each cement was tested on human periodontal ligament fibroblasts using a multiparametric assay. Data analysis was performed using ANOVA and Tukey'spost hoc in GraphPad Prism. ProRoot® MTA had higher radiopacity than RetroMTA®(p<0.001). No significant differences were observed for the pH of the materials throughout experimental periods (p>0.05) although pH levels of both materials reduced over time. Both ProRoot® MTA and RetroMTA® allowed for significantly higher cell viability when compared with the positive control (p<0.001). No statistical difference was observed between ProRoot® MTA and RetroMTA® cytotoxicity level in all test parameters, except for the ProRoot® MTA 48-hour extract media in the NR assay (p<0.05). The current study provides new data about the physicochemical and biological properties of Retro® MTA concerning radiopacity, pH and cytotoxic effects on human periodontal ligaments cells. Based on our findings, RetroMTA® meets the radiopacity requirements standardized by ANSI/ADA number 572, and similar pH values and biocompatibility to ProRoot® MTA. Further studies should be performed to evaluate additional properties of this new material.

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.

Synthesis of mono Mannich bases of 2-(4-hydroxybenzylidene)-2,3-dihydroinden-1-one and evaluation of their cytotoxicities.

PubMed

Tugrak, Mehtap; Yamali, Cem; Sakagami, Hiroshi; Gul, Halise Inci

2016-10-01

Chalcones and Mannich bases are a group of compounds known for their cytotoxicities. In this study restricted chalcone analogue, compound 2-(4-hydroxybenzylidene)-2,3-dihydroinden-1-one MT1, was used as a starting compound to synthesize new mono Mannich bases since Mannich bases may induce more cytotoxicity than chalcone analogue that they are derived from by producing additional alkylating center for cellular thiols. In this study, cyclic and acyclic amines were used to synthesize Mannich bases. All compounds were tested against Ca9-22 (gingival carcinoma), HSC-2, HSC-3 and HSC-4 (oral squamous cell carcinoma) as tumour cell lines and HGF (gingival fibroblasts), HPC (pulp cells) and HPLF (periodontal ligament fibroblasts) human normal oral cells as non tumour cell lines. Cytotoxicity, selectivity index (SI) values and potency selectivity expression (PSE) values expressed as a percentage were determined for the compounds. According to data obtained, the compound MT8 with the highest PSE value bearing N-methylpiperazine moiety seems to be a good candidate to develop new cytotoxic compounds and is suited for further investigation.

Morphology of the dorsal and lateral calcaneocuboid ligaments.

PubMed

Dorn-Lange, Nadja V; Nauck, Tanja; Lohrer, Heinz; Arentz, Sabine; Konerding, Moritz A

2008-09-01

The dorsolateral calcaneocuboid ligaments have different configurations. In the literature they are only described as either the dorsal or lateral calcaneocuboid ligament. However, recent reconstructive surgical techniques may benefit from a better understanding of the anatomy. The aims of this study were to classify the morphology and attachments of the dorso-lateral calcaneocuboid ligaments and to determine their dimensions. The dorso-lateral aspects of the calcaneocuboid joint of 30 cadaver feet were dissected to expose the associated ligaments. Further, we evaluated possible bony landmarks of the calcaneus that could imply which shape or course the ligament would have in a specific individual. Our findings showed a wide variety of configurations in shape, number, and attachment sites. A constant dorsal ligament and an additional narrower lateral ligament was detectable in half of the cases. The majority of the dorso-lateral calcaneocuboid ligament-complex had an upward course and fanning out from proximal to distal. No bony predictor for the ligaments' shape or course was found. The dorso-lateral ligament-complex of the calcaneocuboid joint revealed a wide variety of configurations. Better understanding of the anatomy of these ligaments may aid in the anatomic reconstruction of these ligaments.

Arthroscopic suture anchor repair of the lateral ligament ankle complex: a cadaveric study.

PubMed

Giza, Eric; Shin, Edward C; Wong, Stephanie E; Acevedo, Jorge I; Mangone, Peter G; Olson, Kirstina; Anderson, Matthew J

2013-11-01

Operative treatment of mechanical ankle instability is indicated for patients with multiple sprains and continued episodes of instability. Open repair of the lateral ankle ligaments involves exposure of the attenuated ligaments and advancement back to their anatomic insertions on the fibula using bone tunnels or suture implants. Open and arthroscopic fixation are equal in strength to failure for anatomic Broström repair. Controlled laboratory study. Seven matched pairs of human cadaveric ankle specimens were randomized into 2 groups of anatomic Broström repair: open or arthroscopic. The calcaneofibular ligament and anterior talofibular ligament were excised from their origin on the fibula. In the open repair group, 2 suture anchors were used to reattach the ligaments to their anatomic origins. In the arthroscopic repair group, identical suture anchors were used for repair via an arthroscopic technique. The ligaments were cyclically loaded 20 times and then tested to failure. Torque to failure, degrees to failure, initial stiffness, and working stiffness were measured. A matched-pair analysis was performed. Power analysis of 0.8 demonstrated that 7 pairs needed to show a difference of 30%, with a 15% standard error at a significance level of α = .05. There was no difference in the degrees to failure, torque to failure, or stiffness for the repaired ligament complex. Nine of 14 specimens failed at the suture anchor. There is no statistical difference in strength or stiffness of a traditional open repair as compared with an arthroscopic anatomic repair of the lateral ligaments of the ankle. An arthroscopic technique can be considered for lateral ligament stabilization in patients with mild to moderate mechanical instability.

Regenerative effect of basic fibroblast growth factor on periodontal healing in two-wall intrabony defects in dogs.

PubMed

Shirakata, Yoshinori; Taniyama, Katsuyoshi; Yoshimoto, Takehiko; Miyamoto, Motoharu; Takeuchi, Naoshi; Matsuyama, Takashi; Noguchi, Kazuyuki

2010-04-01

The aim of the present study was to evaluate the effect of a basic fibroblast growth factor (bFGF) candidate treatment on periodontal healing in two-wall intrabony defects in dogs. Two-wall intrabony defects (5 x 5 x 5 mm) were created surgically on the distal and mesial sides of bilateral mandibular second and fourth premolars in four Beagle dogs. bFGF, enamel matrix derivative (EMD) and platelet-derived growth factor with beta-tricalcium phosphate (PDGF/beta-TCP) treatments, and sham-surgery (OFD) were rotated among the four defects in each animal, EMD and PDGF/beta-TCP serving as benchmark controls. The animals were euthanized for radiographic and histologic evaluation at 8 weeks. Bone formation was significantly greater in the bFGF group (4.11 +/- 0.77 mm) than in the EMD (3.32 +/- 0.71 mm; p<0.05) and OFD (3.09 +/- 0.52 mm; p<0.01) groups. The EMD (4.59 +/- 1.19 mm) and PDGF/beta-TCP (4.66 +/- 0.7 mm) groups exhibited significantly greater cementum regeneration with periodontal ligament-like tissue than the OFD group (2.96 +/- 0.69 mm; p<0.01). No significant differences were observed between the bFGF and the PDGF/beta-TCP groups in any of the histometric parameters. The candidate bFGF treatment supported periodontal regeneration comparable with that of established benchmarks: EMD and PDGF/beta-TCP.

Cytotoxicity, interaction with dentine and efficacy on multispecies biofilms of a modified salt solution intended for endodontic disinfection in a new in vitro biofilm model.

PubMed

van der Waal, S V; Scheres, N; de Soet, J J; Wesselink, P R; Crielaard, W

2015-02-01

To investigate the cytotoxicity of a modified salt solution (MSS) and evaluate the antimicrobial properties of MSS on in vitro biofilm models. In a metabolic assay, fibroblasts derived from periodontal ligaments (PDL) of human extracted teeth were cultured and challenged with MSS or controls. Then, in active attachment biofilm models, the efficacy of MSS in the presence of dentine powder and in eliminating mature biofilms was investigated. In the dentine assay, a biofilm of Enterococcus faecalis was employed. For the final assay, microorganisms were retrieved from infected root canals and cultured to produce biofilms. After the treatments with MSS or the controls, the biofilms were collected, serially diluted and plated. The colony-forming units were counted. One-way anova was used to analyse the differences between the groups. A P < 0.05 was considered significant. The PDL fibroblasts remained metabolically active after challenges with MSS. Dentine powder did not alter the efficacy of MSS (P > 0.05). In endodontic biofilms, the culturable bacteria were equally reduced by MSS, 2% chlorhexidine (CHX) or 2% sodium hypochlorite (NaOCl) (P > 0.05). Modified salt solution is noncytotoxic in vitro and has good antimicrobial properties equal to CHX and NaOCl. Although the results are promising, ex vivo and in vivo studies are needed before its use as an interappointment root canal dressing can be considered. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

The broad ligament: a review of its anatomy and development in different species and hormonal environments.

PubMed

Miller, Anne; Hong, Matthew K-H; Hutson, John M

2004-04-01

The broad ligament is a double fold of peritoneum forming a mesentery for the human female genital tract. We investigated the anatomy of the broad ligament in different species and its hormonal regulation to determine if it had a role in gonadal positioning. The medical and veterinary literature was reviewed for descriptions of broad ligament anatomy and development. In addition, four adult female rats were dissected to compare the macroscopic anatomy of the broad ligament with any homologous structures in the male (n = 2). Detailed review was made of human males with persistent Müllerian duct syndrome (PMDS) and of bovine freemartin calves to determine the effect of abnormal hormonal environments on broad ligament development. Human and veterinary texts show variable broad ligament development between species, most being consistent with the size and shape of the uterus and uterine tubes. The broad ligament in adult female rats is a simple peritoneal fold and is homologous with the mesentery of the testis and vas deferens in males. Patients with PMDS and bovine freemartins have a broad ligament with intermediate anatomy. In PMDS the broad ligament is elongated and narrow, and not attached to the pelvic wall. The broad ligament is the mesentery of the genital ducts, and its anatomy varies with the degree of Müllerian duct fusion. The absence of a human male homologue is unusual, as the genital mesentery persists in male rodents. Apparent lack of a male homologue in the human may relate to obliteration of the processus vaginalis. The variable development of the broad ligament in pathological conditions is consistent with a role for steroid hormones in its development. Copyright 2004 Wiley-Liss, Inc.

Tensile properties of the transverse carpal ligament and carpal tunnel complex.

PubMed

Ugbolue, Ukadike C; Gislason, Magnus K; Carter, Mark; Fogg, Quentin A; Riches, Philip E; Rowe, Philip J

2015-08-01

A new sophisticated method that uses video analysis techniques together with a Maillon Rapide Delta to determine the tensile properties of the transverse carpal ligament-carpal tunnel complex has been developed. Six embalmed cadaveric specimens amputated at the mid-forearm and aged (mean (SD)): 82 (6.29) years were tested. The six hands were from three males (four hands) and one female (two hands). Using trigonometry and geometry the elongation and strain of the transverse carpal ligament and carpal arch were calculated. The cross-sectional area of the transverse carpal ligament was determined. Tensile properties of the transverse carpal ligament-carpal tunnel complex and Load-Displacement data were also obtained. Descriptive statistics, one-way ANOVA together with a post-hoc analysis (Tukey) and t-tests were incorporated. A transverse carpal ligament-carpal tunnel complex novel testing method has been developed. The results suggest that there were no significant differences between the original transverse carpal ligament width and transverse carpal ligament at peak elongation (P=0.108). There were significant differences between the original carpal arch width and carpal arch width at peak elongation (P=0.002). The transverse carpal ligament failed either at the mid-substance or at their bony attachments. At maximum deformation the peak load and maximum transverse carpal ligament displacements ranged from 285.74N to 1369.66N and 7.09mm to 18.55mm respectively. The transverse carpal ligament cross-sectional area mean (SD) was 27.21 (3.41)mm(2). Using this method the results provide useful biomechanical information and data about the tensile properties of the transverse carpal ligament-carpal tunnel complex. Copyright © 2015 Elsevier Ltd. All rights reserved.

Whiplash causes increased laxity of cervical capsular ligament

PubMed Central

Ivancic, Paul C.; Ito, Shigeki; Tominaga, Yasuhiro; Rubin, Wolfgang; Coe, Marcus P.; Ndu, Anthony B.; Carlson, Erik J.; Panjabi, Manohar M.

2009-01-01

Background Previous clinical studies have identified the cervical facet joint, including the capsular ligaments, as sources of pain in whiplash patients. The goal of this study was to determine whether whiplash caused increased capsular ligament laxity by applying quasi-static loading to whiplash-exposed and control capsular ligaments. Methods A total of 66 capsular ligament specimens (C2/3 to C7/T1) were prepared from 12 cervical spines (6 whiplash-exposed and 6 control). The whiplash-exposed spines had been previously rear impacted at a maximum peak T1 horizontal acceleration of 8 g. Capsular ligaments were elongated at 1 mm/s in increments of 0.05 mm until a tensile force of 5 N was achieved and subsequently returned to neutral position. Four pre-conditioning cycles were performed and data from the load phase of the fifth cycle were used for subsequent analyses. Ligament elongation was computed at tensile forces of 0, 0.25, 0.5, 0.75, 1.0, 2.5, and 5.0 N. Two factor, non-repeated measures ANOVA (P<0.05) was performed to determine significant differences in the average ligament elongation at tensile forces of 0 and 5 N between the whiplash-exposed and control groups and between spinal levels. Findings Average elongation of the whiplash-exposed capsular ligaments was significantly greater than that of the control ligaments at tensile forces of 0 and 5 N. No significant differences between spinal levels were observed. Interpretation Capsular ligament injuries, in the form of increased laxity, may be one component perpetuating chronic pain and clinical instability in whiplash patients. PMID:17959284

Composition of Mineral Produced by Dental Mesenchymal Stem Cells

PubMed Central

Volponi, A.A.; Gentleman, E.; Fatscher, R.; Pang, Y.W.Y.; Gentleman, M.M.; Sharpe, P.T.

2015-01-01

Mesenchymal stem cells isolated from different dental tissues have been described to have osteogenic/odontogenic-like differentiation capacity, but little attention has been paid to the biochemical composition of the material that each produces. Here, we used Raman spectroscopy to analyze the mineralized materials produced in vitro by different dental cell populations, and we compared them with the biochemical composition of native dental tissues. We show that different dental stem cell populations produce materials that differ in their mineral and matrix composition and that these differ from those of native dental tissues. In vitro, BCMP (bone chip mass population), SCAP (stem cells from apical papilla), and SHED (stem cells from human-exfoliated deciduous teeth) cells produce a more highly mineralized matrix when compared with that produced by PDL (periodontal ligament), DPA (dental pulp adult), and GF (gingival fibroblast) cells. Principal component analyses of Raman spectra further demonstrated that the crystallinity and carbonate substitution environments in the material produced by each cell type varied, with DPA cells, for example, producing a more carbonate-substituted mineral and with SCAP, SHED, and GF cells creating a less crystalline material when compared with other dental stem cells and native tissues. These variations in mineral composition reveal intrinsic differences in the various cell populations, which may in turn affect their specific clinical applications. PMID:26253190

Gross and histologic evaluation of hepatogastric ligaments in clinically normal dogs and dogs with gastric dilatation-volvulus.

PubMed

Hall, J A; Willer, R L; Seim, H B; Powers, B E

1995-12-01

OBJECTIVE--To investigate any potential structural differences in hepatogastric ligaments between clinically normal dogs and dogs with gastric dilatation-volvulus (GDV). DESIGN--Case-control study. ANIMALS--Hepatogastric ligaments were examined in 13 large-breed control dogs and in 13 large-breed dogs referred for surgical treatment of GDV. PROCEDURE--Measurements and biopsies of hepatogastric ligaments were performed at the time of surgery, circumcostal gastropexy, for correction of GDV. Serial sections from each ligament were stained with H&E, Masson's trichrome, and elastin stains to assess morphology, including smooth muscle, collagen, and elastic fiber contents. RESULTS--There were no differences observed by light microscopy in incidence or degree of histopathologic alterations between the 2 groups of dogs. The lengths of hepatogastric ligaments in GDV-affected dogs, however, were significantly longer than those of control dogs (GDV-affected dogs, 7.0 [5.0 to 9.5] cm median [range]; control dogs, 5.0 [3.0 to 7.5] cm median [range]; P = 0.01). CONCLUSIONS--Causality can not be inferred from this study. It is not known whether the ligaments were lengthened as a result of GDV or whether the lengthened ligaments predisposed dogs to GDV. CLINICAL RELEVANCE--This finding may reflect increased laxity of the supporting hepatogastric ligament in the right quadrant of the abdomen. An elongated ligament may permit increased stomach mobility and predispose dogs to partial or complete gastric volvulus.

Extracellular Matrix from Periodontal Ligament Cells Could Induce the Differentiation of Induced Pluripotent Stem Cells to Periodontal Ligament Stem Cell-Like Cells.

PubMed

Hamano, Sayuri; Tomokiyo, Atsushi; Hasegawa, Daigaku; Yoshida, Shinichiro; Sugii, Hideki; Mitarai, Hiromi; Fujino, Shoko; Wada, Naohisa; Maeda, Hidefumi

2018-01-15

The periodontal ligament (PDL) plays an important role in anchoring teeth in the bone socket. Damage to the PDL, such as after severe inflammation, can be treated with a therapeutic strategy that uses stem cells derived from PDL tissue (PDLSCs), a strategy that has received intense scrutiny over the past decade. However, there is an insufficient number of PDLSCs within the PDL for treating such damage. Therefore, we sought to induce the differentiation of induced pluripotent stem (iPS) cells into PDLSCs as an initial step toward PDL therapy. To this end, we first induced iPS cells into neural crest (NC)-like cells. We then captured the p75 neurotrophic receptor-positive cells (iPS-NC cells) and cultured them on an extracellular matrix (ECM) produced by human PDL cells (iPS-NC-PDL cells). These iPS-NC-PDL cells showed reduced expression of embryonic stem cell and NC cell markers as compared with iPS and iPS-NC cells, and enrichment of mesenchymal stem cell markers. The cells also had a higher proliferative capacity, multipotency, and elevated expression of PDL-related markers than iPS-NC cells cultured on fibronectin and laminin (iPS-NC-FL cells) or ECM produced by human skin fibroblast cells (iPS-NC-SF cells). Overall, we present a culture method to produce high number of PDLSC-like cells from iPS cells as a first step toward a strategy for PDL regeneration.

Exploring the in vitro and in vivo compatibility of PLA, PLA/GNP and PLA/CNT-COOH biodegradable nanocomposites: Prospects for tendon and ligament applications.

PubMed

Correia Pinto, Viviana; Costa-Almeida, Raquel; Rodrigues, Ilda; Guardão, Luísa; Soares, Raquel; Miranda Guedes, Rui

2017-08-01

Anterior cruciate ligament (ACL) reconstructive surgeries are the most frequent orthopedic procedures in the knee. Currently, existing strategies fail in completely restoring tissue functionality and have a high failure rate associated, presenting a compelling argument towards the development of novel materials envisioning ACL reinforcement. Tendons and ligaments, in general, have a strong demand in terms of biomechanical features of developed constructs. We have previously developed polylactic acid (PLA)-based biodegradable films reinforced either with graphene nanoplatelets (PLA/GNP) or with carboxyl-functionalized carbon nanotubes (PLA/CNT-COOH). In the present study, we comparatively assessed the biological performance of PLA, PLA/GNP, and PLA/CNT-COOH by seeding human dermal fibroblasts (HFF-1) and studying cell viability and proliferation. In vivo tests were also performed by subcutaneous implantation in 6-week-old C57Bl/6 mice. Results showed that all formulations studied herein did not elicit cytotoxic responses in seeded HFF-1, supporting cell proliferation up to 3 days in culture. Moreover, animal studies indicated no physiological signs of severe inflammatory response after 1 and 2 weeks after implantation. Taken together, our results present a preliminary assessment on the compatibility of PLA reinforced with GNP and CNT-COOH nanofillers, highlighting the potential use of these carbon-based nanofillers for the fabrication of reinforced synthetic polymer-based structures for ACL reinforcement. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2182-2190, 2017. © 2017 Wiley Periodicals, Inc.

Craniocervical junction in dogs revisited--new ligaments and confirmed presence of enthesis fibrocartilage.

PubMed

Kupczynska, M; Wieladek, A; Janczyk, P

2012-06-01

The study was performed to investigate and to describe features of gross and microscopic morphology of craniocervical junction (CCJ) in dogs. Seventy mature dogs (38 females, 32 males) of different body weight, representing small, medium and large breeds of dolicho-, mesati-, and brachycephalic morphotype were dissected. Morphological details were localised using an operating microscope with integrated video channel. Occurrence and distribution of fibrocartilage in the ligaments from 10 dogs was analysed histologically. Three new pairs of ligaments were described and named: dorsal ligaments of atlas, cranial internal collateral ligaments of atlas, and caudal internal collateral ligaments of atlas. Several new findings in the course of the known ligaments were found relating to breed and body weight. For the first time enthesis fibrocartilage was identified in ligaments of CCJ in dogs. Sesamoidal fibrocartilage was identified in the transversal ligament of atlas in large dogs. The findings are discussed for clinical importance. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparison of the biomechanical properties of rottweiler and racing greyhound cranial cruciate ligaments.

PubMed

Wingfield, C; Amis, A A; Stead, A C; Law, H T

2000-07-01

An in vitro study of rottweiler and racing greyhound cranial cruciate ligaments revealed that the rottweiler ligaments had a significantly greater cross-sectional area at their distal attachments. Mechanical testing showed that the ultimate load related to body mass was significantly higher in the extended racing greyhound stifle during cranial tibial loading to failure, as were linear stiffness, tensile strength and tangent modulus. During ligament axis loading to failure, the only significant difference in structural and mechanical properties recorded between the two breeds was a greater ultimate strain for the greyhound ligament with the stifle joint flexed. Energy absorbed by the ligament complex at failure during cranial tibial loading was twice that for ligament axis loading for both breeds. The clinical significance is that the rottweiler cranial cruciate ligament is more vulnerable to damage as it requires half the load per unit body mass that the greyhound requires to cause a rupture.

The in situ force in the calcaneofibular ligament and the contribution of this ligament to ankle joint stability.

PubMed

Kobayashi, Takuma; Yamakawa, Satoshi; Watanabe, Kota; Kimura, Kei; Suzuki, Daisuke; Otsubo, Hidenori; Teramoto, Atsushi; Fujimiya, Mineko; Fujie, Hiromichi; Yamashita, Toshihiko

2016-12-01

Numerous biomechanical studies of the lateral ankle ligaments have been reported; however, the isolated function of the calcaneofibular ligament has not been clarified. We hypothesize that the calcaneofibular ligament would stabilize the ankle joint complex under multidirectional loading, and that the in situ force in the calcaneofibular ligament would change in each flexed position. Using seven fresh frozen cadaveric lower extremities, the motions and forces of the intact ankle under multidirectional loading were recorded using a 6-degree-of-freedom robotic system. On repeating these intact ankle joint complex motions after the calcaneofibular ligament transection, the in situ force in the calcaneofibular ligament and the contribution of the calcaneofibular ligament to ankle joint complex stability were calculated. Finally, the motions of the calcaneofibular ligament-transected ankle joint complex were recorded. Under an inversion load, significant increases of inversion angle were observed in all the flexed positions following calcaneofibular ligament transection, and the calcaneofibular ligament accounted for 50%-70% of ankle joint complex stability during inversion. The in situ forces in the calcaneofibular ligament under an anterior force, inversion moment, and external rotation moment were larger in the dorsiflexed position than in the plantarflexed position. The calcaneofibular ligament plays a role in stabilizing the ankle joint complex to multidirectional loads and the role differs with load directions. The in situ force of the calcaneofibular ligament is larger at the dorsiflexed position. This ligament provides the primary restraint to the inversion ankle stability. Copyright © 2016 Elsevier Ltd. All rights reserved.

Loading rate effect on mechanical properties of cervical spine ligaments.

PubMed

Trajkovski, Ana; Omerovic, Senad; Krasna, Simon; Prebil, Ivan

2014-01-01

Mechanical properties of cervical spine ligaments are of great importance for an accurate finite element model when analyzing the injury mechanism. However, there is still little experimental data in literature regarding fresh human cervical spine ligaments under physiological conditions. The focus of the present study is placed on three cervical spine ligaments that stabilize the spine and protect the spinal cord: the anterior longitudinal ligament, the posterior longitudinal ligament and the ligamentum flavum. The ligaments were tested within 24-48 hours after death, under two different loading rates. An increase trend in failure load, failure stress, stiffness and modulus was observed, but proved not to be significant for all ligament types. The loading rate had the highest impact on failure forces for all three ligaments (a 39.1% average increase was found). The observed increase trend, compared to the existing increase trends reported in literature, indicates the importance of carefully applying the existing experimental data, especially when creating scaling factors. A better understanding of the loading rate effect on ligaments properties would enable better case-specific human modelling.

Effects of TiO2 nano glass ionomer cements against normal and cancer oral cells.

PubMed

Garcia-Contreras, Rene; Scougall-Vilchis, Rogelio J; Contreras-Bulnes, Rosalia; Kanda, Yumiko; Nakajima, Hiroshi; Sakagami, Hiroshi

2014-01-01

Incorporation of nanoparticles (NPs) into the glass ionomer cements (GICs) is known to improve their mechanical and antibacterial properties. The present study aimed to investigate the possible cytotoxicity and pro-inflammation effect of three different powdered GICs (base, core build and restorative) prepared with and without titanium dioxide (TiO2) nanoparticles. Each GIC was blended with TiO2 nanopowder, anatase phase, particle size <25 nm at 3% and 5% (w/w), and the GIC blocks of cements were prepared in a metal mold. The GICs/TiO2 nanoparticles cements were smashed up with a mortar and pestle to a fine powder, and then subjected to the sterilization by autoclaving. Human oral squamous cell carcinoma cell lines (HCS-2, HSC-3, HSC-4, Ca9-22) and human normal oral cells [gingival fibroblast (HGF), pulp (HPC) and periodontal ligament fibroblast (HPLF)] were incubated with different concentrations of GICs in the presence or absence of TiO2 nanoparticles, and the viable cell number was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Prostaglandin E2 was quantified by enzyme-linked immunosorbent assay (ELISA). Changes in fine cell structure were assessed by transmission electron microscopy. Cancer cells exhibited moderate cytotoxicity after 48 h of incubation, regardless of the type of GIC and the presence or absence of TiO2 NPs. GICs induced much lower cytotoxicity against normal cells, but induced prostaglandin E2 production, in a synergistic wanner with interleukin-1β. The present study shows acceptable to moderate biocompatibility of GICs impregnated with TiO2 nanoparticles, as well as its pro-inflammatory effects at higher concentrations. Copyright © 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Alterations of the transverse ligament: an MRI study comparing patients with acute whiplash and matched control subjects.

PubMed

Ulbrich, Erika Jasmin; Eigenheer, Sandra; Boesch, Chris; Hodler, Juerg; Busato, André; Schraner, Christian; Anderson, Suzanne E; Bonel, Harald; Zimmermann, Heinz; Sturzenegger, Matthias

2011-10-01

The objective of our study was to evaluate whether there is injury to the transverse ligament of the atlas in patients with acute whiplash. Ninety patients with an acute (< 48 hours) symptomatic whiplash-associated injury and 90 healthy age- and sex-matched asymptomatic control subjects (mean age of patients and control subjects, 36 years) were included. The maximal sagittal thickness of the transverse ligament was measured on midsagittal T1 volumetric interpolated breath-hold examination (VIBE) images and transverse reformatted VIBE images. The signal intensity of the transverse ligament was measured on transverse STIR images and on transverse reformatted T1 VIBE images before and after IV administration of gadoterate. Contrast between the transverse ligament and CSF and alterations of contrast after gadoterate injection were calculated. Patients had a minimally thicker transverse ligament (posttraumatic swelling) than control subjects, and the difference in thickness was significant in men only (p = 0.03). In patients, a significant signal alteration of the transverse ligament (p = 0.03) was seen on STIR (posttraumatic edema) and native VIBE sequences. The contrast between the transverse ligament and the CSF on VIBE images was significantly (p = 0.005) lower in patients than in control subjects. With the application of a contrast agent, the contrast difference between the transverse ligament and CSF in patients and control subjects was less pronounced (p = 0.038). There was no abnormal uptake of contrast agent by the transverse ligament or CSF. The results of our study indicate possible involvement of the transverse ligament in whiplash injury. Although MRI may be helpful to study injury-related changes of anatomic structures in cohorts, it is not suited for individual diagnosis because the alterations are too small.

Is it possible to re-establish pre-operative patellar kinematics using a ligament-balanced technique in total knee arthroplasty? A cadaveric investigation.

PubMed

Keshmiri, Armin; Springorum, Hans; Baier, Clemens; Zeman, Florian; Grifka, Joachim; Maderbacher, Günther

2015-03-01

Several authors emphasise that the appearance of patellar maltracking after total knee arthroplasty (TKA) is caused by rotational malalignment of the femoral and tibial components. Ligament-balanced femoral component rotation was not found to be associated with abnormal postoperative patellar position. We hypothesised that a ligament-balanced technique in TKA has the ability to best re-establish patellar kinematics. In ten cadaveric knees TKA was performed assessing femoral rotation in ligament-balanced and different femoral and tibial component rotation alignments. Patellar kinematics after different component rotations were analysed using a commercial computer navigation system. Ligament-balanced femoral rotation showed the best re-establishment of patellar kinematics after TKA compared to the healthy pre-operative knee. In contrast to tibial component rotation, femoral component rotation had a major impact on patellofemoral kinematics. This investigation suggests that a ligament-balanced technique in TKA is most likely to re-establish natural patellofemoral kinematics. Tibial component rotation did not influence patellar kinematics.

Effects of concomitant use of fibroblast growth factor (FGF)-2 with beta-tricalcium phosphate ({beta}-TCP) on the beagle dog 1-wall periodontal defect model

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

Anzai, Jun, E-mail: anzai_jun@kaken.co.jp; Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871; Kitamura, Masahiro, E-mail: kitamura@dent.osaka-u.ac.jp

Research highlights: {yields} Concomitant use of FGF-2 and {beta}-TCP (an osteo-conductive scaffold) significantly promotes periodontal regeneration in the severe periodontitis model (1-wall defect model) of beagle dog. {yields} FGF-2 enhanced new bone formation via {beta}-TCP at the defects. {yields} In particular, FGF-2 dramatically regenerated new periodontal ligament and cementum formations at the defects, that is one of the most important healing outcomes during the process of periodontal regeneration. {yields} Epithelial downgrowth (undesirable wound healing) was decreased by administration of FGF-2. {yields} This manuscript indicates for the first time that concomitant use of FGF-2 and {beta}-TCP is efficacious in regenerating periodontalmore » tissue following severe destruction of the tissue by progression of periodontitis. -- Abstract: The effects of concomitant use of fibroblast growth factor-2 (FGF-2) and beta-tricalcium phosphate ({beta}-TCP) on periodontal regeneration were investigated in the beagle dog 1-wall periodontal defect model. One-wall periodontal defects were created in the mesial portion of both sides of the mandibular first molars, and 0.3% FGF-2 plus {beta}-TCP or {beta}-TCP alone was administered. Radiographic evaluation was performed at 0, 3, and 6 weeks. At 6 weeks, the periodontium with the defect site was removed and histologically analyzed. Radiographic findings showed that co-administration of FGF-2 significantly increased bone mineral contents of the defect sites compared with {beta}-TCP alone. Histologic analysis revealed that the length of the regenerated periodontal ligament, the cementum, distance to the junctional epithelium, new bone height, and area of newly formed bone were significantly increased in the FGF-2 group. No abnormal inflammatory response or ankylosis was observed in either group. These findings indicate the efficacy of concomitant use of FGF-2 and {beta}-TCP as an osteoconductive material for periodontal regeneration following severe destruction by progressive periodontitis.« less

2015 Young Investigator Award Winner: Cervical Nerve Root Displacement and Strain During Upper Limb Neural Tension Testing: Part 2: Role of Foraminal Ligaments in the Cervical Spine.

PubMed

Lohman, Chelsea M; Gilbert, Kerry K; Sobczak, Stéphane; Brismée, Jean-Michel; James, C Roger; Day, Miles; Smith, Michael P; Taylor, LesLee; Dugailly, Pierre-Michel; Pendergrass, Timothy; Sizer, Phillip J

2015-06-01

A cross-sectional cadaveric examination of the mechanical effect of foraminal ligaments on cervical nerve root displacement and strain. To determine the role of foraminal ligaments by examining differences in cervical nerve root displacement and strain during upper limb neural tension testing (ULNTT) before and after selective cutting of foraminal ligaments. Although investigators have determined that lumbar spine foraminal ligaments limit displacement and strain of lumbosacral nerve roots, similar studies have not been conducted to prove that it is true for the cervical region. Because the size, shape, and orientation of cervical spine foraminal ligaments are similar to those in the lumbar spine, it is hypothesized that foraminal ligaments in the cervical spine will function in a similar fashion. Radiolucent markers were implanted into cervical nerve roots C5-C8 of 9 unembalmed cadavers. Posteroanterior fluoroscopic images were captured at resting and upper limb neural tension testing positioning before and after selective cutting of foraminal ligaments. Selective cutting of foraminal ligaments resulted in significant increases in inferolateral displacement (average, 2.94 mm [ligaments intact]-3.87 mm [ligaments cut], P < 0.05) and strain (average, 9.33% [ligaments intact]-16.31% [ligaments cut], P < 0.03) of cervical nerve roots C5-C8 during upper limb neural tension testing. Foraminal ligaments in the cervical spine limited cervical nerve root displacement and strain during upper limb neural tension testing. Foraminal ligaments seem to have a protective role, reducing displacement and strain to cervical nerve roots during tension events. 2.

Numerical damage models using a structural approach: application in bones and ligaments

NASA Astrophysics Data System (ADS)

Arnoux, P. J.; Bonnoit, J.; Chabrand, P.; Jean, M.; Pithioux, M.

2002-01-01

The purpose of the present study was to apply knowledge of structural properties to perform numerical simulations with models of bones and knee ligaments exposed to dynamic tensile loading leading to tissue damage. Compact bones and knee ligaments exhibit the same geometrical pattern in their different levels of structural hierarchy from the tropocollagen molecule to the fibre. Nevertheless, their mechanical behaviours differ considerably at the fibril level. These differences are due to the contribution of the joints in the microfibril-fibril-fibre assembly and to the mechanical properties of the structural components. Two finite element models of the fibrous bone and ligament structure were used to describe damage in terms of elastoplastic laws or joint decohesion processes.

Mechanical stability of the subtalar joint after lateral ligament sectioning and ankle brace application: a biomechanical experimental study.

PubMed

Kamiya, Tomoaki; Kura, Hideji; Suzuki, Daisuke; Uchiyama, Eiichi; Fujimiya, Mineko; Yamashita, Toshihiko

2009-12-01

The roles of each ligament supporting the subtalar joint have not been clarified despite several biomechanical studies. The effects of ankle braces on subtalar instability have not been shown. The ankle brace has a partial effect on restricting excessive motion of the subtalar joint. Controlled laboratory study. Ten normal fresh-frozen cadaveric specimens were used. The angular motions of the talus were measured via a magnetic tracking system. The specimens were tested while inversion and eversion forces, as well as internal and external rotation torques, were applied. The calcaneofibular ligament, cervical ligament, and interosseous talocalcaneal ligament were sectioned sequentially, and the roles of each ligament, as well as the stabilizing effects of the ankle brace, were examined. Complete sectioning of the ligaments increased the angle between the talus and calcaneus in the frontal plane to 51.7 degrees + or - 11.8 degrees compared with 35.7 degrees + or - 6.0 degrees in the intact state when inversion force was applied. There was a statistically significant difference in the angles between complete sectioning of the ligaments and after application of the brace (34.1 degrees + or - 7.3 degrees ) when inversion force was applied. On the other hand, significant differences in subtalar rotation were not found between complete sectioning of the ligaments and application of the brace when internal and external rotational torques were applied. The ankle brace limited inversion of the subtalar joint, but it did not restrict motion after application of internal or external rotational torques. In cases of severe ankle sprains involving the calcaneofibular ligament, cervical ligament, and interosseous talocalcaneal ligament injuries, application of an ankle brace might be less effective in limiting internal-external rotational instabilities than in cases of inversion instabilities in the subtalar joint. An improvement in the design of the brace is needed to restore better rotational stability in the subtalar joint.

[Ganglions of the wrist: proposals for topographical systematization and natural history].

PubMed

Kuhlmann, J-N; Luboinski, J; Baux, S; Mimoun, M

2003-06-01

We looked for the anatomic origin and mechanism of constitution of the so-called "ganglions" of the wrist. Fifty-nine formations considered to be synovial ganglions were dissected and removed according to the same protocol by the same surgeon. Eleven were re-examined by a pathologist. All ganglions were extra-articular but had intra- and extra-capsular components. The extra-capsular part was the clinically palpable main cyst. The intra-capsular part was composed of the cystic stalk and its base of implantation. An intra-capsular stalk was present in 58 cases. The stalk was situated between the joint synovium and the capsula which it perforated at a weak point between two ligaments, forming a collar before expanding outwardly. Based on our findings, we propose a topographical systematization and natural history of ganglions of the wrist. The stalk's implantation base was always located on bone and found in the intermediate area of Colomniati and Soubbotine, which lies outside the articular cartilage between the synovium and the ligamentous capsula. This area is exposed to mechanical stress initiating histological degenerative lesions, particularly mucoid degeneration. At the radiocarpal joint, the stalk's base of implantation was located at the distal end of the lateral dorsal or volar edge of the lunate bone or at the corresponding part of the scaphoid. The collar of the proximal ganglions was situated between the dorsal radiocarpal and transverse scaphotriquetral ligament. The collar of distal dorsal ganglions was situated between the transverse scaphotriquetral and the trapezotriquetral ligament. The collar of the lateral ganglions was situated between the lateral collateral and the transverse ligament. The collar of the volar ganglions was situated between the stylocarpal ligament and the radiolunotriquetral ligament, or between the different stylocarpal ligaments. At the level of the scaphotrapezal joint, the stalk's base of implantation was located near the collateral edge of the distal surface of the joint with the collar between the distal scaphoidal ligaments. The palmar cysts exhibited a collar between the stylocarpal ligaments and the radiolunotriquetral ligament or between the different stylocarpal ligaments. At pathology examination, the lesions were not found to be different from those observed in other connective tissues exposed to overuse or repeated microtrauma (sports, occupational exposure). Anatomic conditions inside the joint capsula excluded extension of the mucoid degeneration transversally. The only issue was through the capsula, allowing the mucus enclosed in the connective tissue fibers to form the main cyst. Knowledge of these different processes enabled a topographical systematization useful for complete surgical or arthroscopic removal of the ganglion. Complete resection would prevent recurrence.

In vivo Length Change Patterns of the Medial and Lateral Collateral Ligaments along the Flexion Path of the Knee

PubMed Central

Hosseini, Ali; Qi, Wei; Tsai, Tsung-Yuan; Liu, Yujie; Rubash, Harry; Li, Guoan

2014-01-01

Purpose The knowledge of the function of the collateral ligaments – i.e., superficial medial collateral ligament (sMCL), deep medial collateral ligament (dMCL) and lateral collateral ligament (LCL) – in the entire range of knee flexion is important for soft tissue balance during total knee arthroplasty. The objective of this study was to investigate the length changes of different portions (anterior, middle and posterior) of the sMCL, dMCL and LCL during in vivo weightbearing flexion from full extension to maximal knee flexion. Methods Using a dual fluoroscopic imaging system eight healthy knees were imaged while performing a lunge from full extension to maximal flexion. The length changes of each portion of the collateral ligaments were measured along the flexion path of the knee. Results All anterior portions of the collateral ligaments were shown to have increasing length with flexion except that of the sMCL which showed a reduction in length at high flexion. The middle portions showed minimal change in lengths except that of the sMCL which showed a consistent reduction in length with flexion. All posterior portions showed reduction in lengths with flexion. Conclusions These data indicated that every portion of the ligaments may play important roles in knee stability at different knee flexion range. The soft tissue releasing during TKA may need to consider the function of the ligament portions along the entire flexion path including maximum flexion. PMID:25239504

Macroscopic and microscopic analysis of the thumb carpometacarpal ligaments: a cadaveric study of ligament anatomy and histology.

PubMed

Ladd, Amy L; Lee, Julia; Hagert, Elisabet

2012-08-15

Stability and mobility represent the paradoxical demands of the human thumb carpometacarpal joint, yet the structural origin of each functional demand is poorly defined. As many as sixteen and as few as four ligaments have been described as primary stabilizers, but controversy exists as to which ligaments are most important. We hypothesized that a comparative macroscopic and microscopic analysis of the ligaments of the thumb carpometacarpal joint would further define their role in joint stability. Thirty cadaveric hands (ten fresh-frozen and twenty embalmed) from nineteen cadavers (eight female and eleven male; average age at the time of death, seventy-six years) were dissected, and the supporting ligaments of the thumb carpometacarpal joint were identified. Ligament width, length, and thickness were recorded for morphometric analysis and were compared with use of the Student t test. The dorsal and volar ligaments were excised from the fresh-frozen specimens and were stained with use of a triple-staining immunofluorescent technique and underwent semiquantitative analysis of sensory innervation; half of these specimens were additionally analyzed for histomorphometric data. Mixed-effects linear regression was used to estimate differences between ligaments. Seven principal ligaments of the thumb carpometacarpal joint were identified: three dorsal deltoid-shaped ligaments (dorsal radial, dorsal central, posterior oblique), two volar ligaments (anterior oblique and ulnar collateral), and two ulnar ligaments (dorsal trapeziometacarpal and intermetacarpal). The dorsal ligaments were significantly thicker (p < 0.001) than the volar ligaments, with a significantly greater cellularity and greater sensory innervation compared with the anterior oblique ligament (p < 0.001). The anterior oblique ligament was consistently a thin structure with a histologic appearance of capsular tissue with low cellularity. The dorsal deltoid ligament complex is uniformly stout and robust; this ligament complex is the thickest morphometrically, has the highest cellularity histologically, and shows the greatest degree of sensory nerve endings. The hypocellular anterior oblique ligament is thin, is variable in its location, and is more structurally consistent with a capsular structure than a proper ligament.

MR imaging of knees having isolated and combined ligament injuries.

PubMed

Rubin, D A; Kettering, J M; Towers, J D; Britton, C A

1998-05-01

Although clinical evaluation and MR imaging both accurately reveal injuries in knees with isolated ligament tears, physical examination becomes progressively less reliable when multiple lesions exist. We investigated the accuracy of MR imaging of knees having varying degrees and numbers of ligament injuries. We prospectively interpreted the MR images of 340 consecutive injured knees and compared these interpretations with the results of subsequent arthroscopy or open surgery, which served as the gold standard. Our interpretations of MR images focused on five soft-tissue supporting structures (the two cruciate ligaments, the two collateral ligaments, and the patellar tendon) and the two menisci. Patients were divided into three groups: no ligament injuries, single ligament injuries, and multiple ligament injuries. Using MR imaging, we found overall sensitivity and specificity for diagnosing ligament tears to be 94% and 99%, respectively, when no or one ligament was torn and 88% and 84%, respectively, when two or more supporting structures were torn. The difference in specificity was statistically significant (p < .0001). Sensitivity for diagnosing meniscal tears decreased as the number of injured structures increased, but the relationship achieved statistical significance (p = .001) only for the medial meniscus. For all categories of injury, MR imaging was more accurate than clinical evaluation, statistics for which were taken from the orthopedic literature. In knees with multiple ligament injuries, the diagnostic specificity of MR imaging for ligament tears decreases, as does the sensitivity for medial meniscal tears.

Tissues from equine cadaver ligaments up to 72 hours of post-mortem: a promising reservoir of stem cells.

PubMed

Shikh Alsook, Mohamad Khir; Gabriel, Annick; Piret, Joëlle; Waroux, Olivier; Tonus, Céline; Connan, Delphine; Baise, Etienne; Antoine, Nadine

2015-12-18

Mesenchymal stem cells (MSCs) harvested from cadaveric tissues represent a promising approach for regenerative medicine. To date, no study has investigated whether viable MSCs could survive in cadaveric tissues from tendon or ligament up to 72 hours of post-mortem. The purpose of the present work was to find out if viable MSCs could survive in cadaveric tissues from adult equine ligaments up to 72 hours of post-mortem, and to assess their ability (i) to remain in an undifferentiated state and (ii) to divide and proliferate in the absence of any specific stimulus. MSCs were isolated from equine cadaver (EC) suspensory ligaments within 48-72 hours of post-mortem. They were evaluated for viability, proliferation, capacity for tri-lineage differentiation, expression of cell surface markers (CD90, CD105, CD73, CD45), pluripotent transcription factor (OCT-4), stage-specific embryonic antigen-1 (SSEA-1), neuron-specific class III beta-tubulin (TUJ-1), and glial fibrillary acidic protein (GFAP). As well, they were characterized by transmission electron microscope (TEM). EC-MSCs were successfully isolated and maintained for 20 passages with high cell viability and proliferation. Phase contrast microscopy revealed that cells with fibroblast-like appearance were predominant in the culture. Differentiation assays proved that EC-MSCs are able to differentiate towards mesodermal lineages (osteogenic, adipogenic, chondrogenic). Flow cytometry analysis demonstrated that EC-MSCs expressed CD90, CD105, and CD73, while being negative for the leukocyte common antigen CD45. Immunofluorescence analysis showed a high percentage of positive cells for OCT-4 and SSEA-1. Surprisingly, in absence of any stimuli, some adherent cells closely resembling neuronal and glial morphology were also observed. Interestingly, our results revealed that approximately 15 % of the cell populations were TUJ-1 positive, whereas GFAP expression was detected in only a few cells. Furthermore, TEM analysis confirmed the stemness of EC-MSCs and identified some cells with a typical neuronal morphology. Our findings raise the prospect that the tissues harvested from equine ligaments up to 72 hours of post-mortem represent an available reservoir of specific stem cells. EC-MSCs could be a promising alternative source for tissue engineering and stem cell therapy in equine medicine.

Effect of posterior cruciate ligament rupture on the radial displacement of lateral meniscus.

PubMed

Lei, Pengfei; Sun, Rongxin; Hu, Yihe; Li, Kanghua; Liao, Zhan

2015-06-01

The relationship between lateral meniscus tear and posterior cruciate ligament injury is not well understood. The present study aims to investigate and assess the effect of posterior cruciate ligament rupture on lateral meniscus radial displacement at different flexion angles under static loading conditions. Twelve fresh human cadaveric knee specimens were divided into four groups such as posterior cruciate ligament intact, anterolateral band rupture, posteromedial band rupture and posterior cruciate ligament complete rupture groups, according to the purpose and order of testing. Radial displacement of lateral meniscus was measured under different loads (200-1000N) at 0°, 30°, 60°, and 90° of knee flexion. Compared with posterior cruciate ligament intact group, the displacement values of lateral meniscus in anterolateral band rupture group increased at 0° flexion with 600N, 800N, and 1000N and at 30°, 60° and 90° flexion under all loading conditions. Posteromedial band rupture group exhibited higher displacement at 0° flexion under all loading conditions, at 30° and 60° flexion with 600, 800N and 1000N, and at 90° flexion with 400N, 600N, 800N, and 1000N than the posterior cruciate ligament intact group. The posterior cruciate ligament complete rupture group had a higher displacement value of lateral medial meniscus at 0°, 30°, 60° and 90° flexion under all loading conditions, as compared to the posterior cruciate ligament intact group. The study concludes that partial and complete rupture of the posterior cruciate ligament can trigger the increase of radial displacement on lateral meniscus. Copyright © 2015 Elsevier Ltd. All rights reserved.

Imaging of the anterior cruciate ligament

PubMed Central

Ng, Wing Hung Alex; Griffith, James Francis; Hung, Esther Hiu Yee; Paunipagar, Bhawan; Law, Billy Kan Yip; Yung, Patrick Shu Hang

2011-01-01

The anterior cruciate ligament (ACL) is an important structure in maintaining the normal biomechanics of the knee and is the most commonly injured knee ligament. However, the oblique course of the ACL within the intercondylar fossa limits the visualization and assessment of the pathology of the ligament. This pictorial essay provides a comprehensive and illustrative review of the anatomy and biomechanics as well as updated information on different modalities of radiological investigation of ACL, particularly magnetic resonance imaging. PMID:22474639

Bioactivities of anastasia black (Russian sweet pepper).

PubMed

Shirataki, Yoshiaki; Kawase, Masami; Sakagami, Hiroshi; Nakashima, Hideki; Tani, Satoru; Tanaka, Toru; Sohara, Yoshitaka; Schelz, Zsuzsanna; Molnar, Joseph; Motohashi, Noboru

2005-01-01

Anastasia Black (Russian sweet pepper) of Capsicum annuum L. var. angulosum Mill. (Solanaceae) was successively extracted with hexane, acetone, methanol and 70% methanol, and the extracts were further separated into a total of twenty-three fractions by silica gel or octadecylsilane (ODS; C18) column chromatography. These extracts and fractions were investigated for their cytotoxicity, anti-human immunodeficiency virus (HIV), anti-Helicobacter pylori (H. pylori), urease inhibition and multidrug resistance (MDR) reversal activity. Some fractions of hexane and acetone extracts showed higher cytotoxic activity against three human oral tumor cell lines (squamous cell carcinoma HSC-2, HSC-3, submandibular gland carcinoma HSG) than against three normal human oral cells (gingival fibroblast HGF, pulp cell HPC, periodontal ligament fibroblast HPLF), suggesting a tumor-specific cytotoxic activity. No fractions displayed anti-HIV activity, but some hydrophobic fractions showed higher anti-H. pylori activity, urease inhibition activity and MDR reversal activity. The higher MDR activity of these fractions against MDR gene-transfected L5178 mouse lymphoma T cells may possibly be due to their higher content of carotene or polyphenol. These data suggest that Anastasia Black should be further investigated as a potent supplement for cancer chemotherapy.

Auto-transplanted mesenchymal stromal cell fate in periodontal tissue of beagle dogs.

PubMed

Wei, Na; Gong, Ping; Liao, Dapeng; Yang, Xingmei; Li, Xiaoyu; Liu, Yurong; Yuan, Quan; Tan, Zhen

2010-07-01

Mesenchymal stromal cells (MSC) possess multilineage differentiation potential and characteristics of self-renewal. It has been reported that MSC can acquire characteristics of cells in the periodontal ligament (PDL) in vitro. Moreover, the transplantation of MSC has been shown to be a promising strategy for treating periodontal defects. However, little is known about the fate of MSC in periodontal tissue in vivo. The aim of this study was to trace the paths of MSC after transplantation into periodontal tissues in vivo. MSC labeled with bromodeoxyuridine (BrdU) were transplanted into periodontal defects of beagle dogs. Six weeks after surgery, the animals were killed and decalcified specimens were prepared. Migration and differentiation of MSC were detected by single/double immunohistochemistry and a combination of immunohistochemistry and in situ hybridization. BrdU-labeled MSC were observed distributing into periodontal tissue that included alveolar bone, PDL, cementum and blood vessels and expressing surface markers typical of osteoblasts and fibroblasts. Cumulatively, our data suggest that MSC migrate throughout periodontal tissue and differentiate into osteoblasts and fibroblasts after transplantation into periodontal defects at 6 weeks in vivo, and have the potential to regenerate periodontal tissue.

Posterior cruciate ligament: anatomy, biomechanics, and outcomes.

PubMed

Voos, James E; Mauro, Craig S; Wente, Todd; Warren, Russell F; Wickiewicz, Thomas L

2012-01-01

The optimal treatment of posterior cruciate ligament ruptures remains controversial despite numerous recent basic science advances on the topic. The current literature on the anatomy, biomechanics, and clinical outcomes of posterior cruciate ligament reconstruction is reviewed. Recent studies have quantified the anatomic location and biomechanical contribution of each of the 2 posterior cruciate ligament bundles on tunnel placement and knee kinematics during reconstruction. Additional laboratory and cadaveric studies have suggested double-bundle reconstructions of the posterior cruciate ligament may better restore normal knee kinematics than single-bundle reconstructions although clinical outcomes have not revealed such a difference. Tibial inlay posterior cruciate ligament reconstructions (either open or arthroscopic) are preferred by many authors to avoid the "killer turn" and graft laxity with cyclic loading. Posterior cruciate ligament reconstruction improves subjective patient outcomes and return to sport although stability and knee kinematics may not return to normal.

[Fabrication and in vivo implantation of ligament-bone composite scaffolds based on three-dimensional printing technique].

PubMed

Zhang, Wenyou; He, Jiankang; Li, Xiang; Liu, Yaxiong; Bian, Weiguo; Li, Dichen; Jin, Zhongmin

2014-03-01

To solve the fixation problem between ligament grafts and host bones in ligament reconstruction surgery by using ligament-bone composite scaffolds to repair the ligaments, to explore the fabrication method for ligament-bone composite scaffolds based on three-dimensional (3-D) printing technique, and to investigate their mechanical and biological properties in animal experiments. The model of bone scaffolds was designed using CAD software, and the corresponding negative mould was created by boolean operation. 3-D printing techinique was employed to fabricate resin mold. Ceramic bone scaffolds were obtained by casting the ceramic slurry in the resin mould and sintering the dried ceramics-resin composites. Ligament scaffolds were obtained by weaving degummed silk fibers, and then assembled with bone scaffolds and bone anchors. The resultant ligament-bone composite scaffolds were implanted into 10 porcine left anterior cruciate ligament rupture models at the age of 4 months. Mechanical testing and histological examination were performed at 3 months postoperatively, and natural anterior cruciate ligaments of the right sides served as control. Biomechanical testing showed that the natural anterior cruciate ligament of control group can withstand maximum tensile force of (1 384 +/- 181) N and dynamic creep of (0.74 +/- 0.21) mm, while the regenerated ligament-bone scaffolds of experimental group can withstand maximum tensile force of (370 +/- 103) N and dynamic creep of (1.48 +/- 0.49) mm, showing significant differences (t = 11.617, P = 0.000; t = 2.991, P = 0.020). In experimental group, histological examination showed that new bone formed in bone scaffolds. A hierarchical transition structure regenerated between ligament-bone scaffolds and the host bones, which was similar to the structural organizations of natural ligament-bone interface. Ligament-bone composite scaffolds based on 3-D printing technique facilitates the regeneration of biomimetic ligament-bone interface. It is expected to achieve physical fixation between ligament grafts and host bone.

Biaxial quantification of deep layer transverse carpal ligament elastic properties by sex and region.

PubMed

Mathers, Bryan; Agur, Anne; Oliver, Michele; Gordon, Karen

2016-12-01

The transverse carpal ligament is a major component of the carpal tunnel and is an important structure in the etiology of carpal tunnel syndrome. The current study aimed to quantify biaxial elastic moduli of the transverse carpal ligament and compare differences between sex and region (Radial and Ulnar). Biaxial testing of radial and ulnar samples from twenty-two (thirteen male, nine female) human fresh frozen cadaveric transverse carpal ligaments was performed. Elastic moduli and stiffness were calculated and compared. Biaxial elastic moduli of the transverse carpal ligament ranged from 0.76MPa to 3.38MPa, varying based on region (radial and ulnar), testing direction (medial-lateral and proximal-distal) and sex. Biaxial elastic moduli were significantly larger in the medial-lateral direction than the proximal-distal direction (P<0.001). Moduli were significantly larger ulnarly than radially (P=0.001). No significant differences due to gender were noted. The regional variations in biaxial elastic moduli of the transverse carpal ligament may help improve non-invasive treatment methods for carpal tunnel syndrome, specifically manipulative therapy. The smaller biaxial elastic moduli found in the radial region suggests that manipulative therapy should be focused on the radial aspect of the transverse carpal ligament. The trend where female transverse carpal ligaments had larger stiffness in the ulnar location than males suggests that that the increased prevalence of carpal tunnel syndrome in women may be related to an increased stiffness of the transverse carpal ligament, however further work is warranted to evaluate this trend. Copyright © 2016 Elsevier Ltd. All rights reserved.

Numerical model for healthy and injured ankle ligaments.

PubMed

Forestiero, Antonella; Carniel, Emanuele Luigi; Fontanella, Chiara Giulia; Natali, Arturo Nicola

2017-06-01

The aim of this work is to provide a computational tool for the investigation of ankle mechanics under different loading conditions. The attention is focused on the biomechanical role of ankle ligaments that are fundamental for joints stability. A finite element model of the human foot is developed starting from Computed Tomography and Magnetic Resonance Imaging, using particular attention to the definition of ankle ligaments. A refined fiber-reinforced visco-hyperelastic constitutive model is assumed to characterize the mechanical response of ligaments. Numerical analyses that interpret anterior drawer and the talar tilt tests reported in literature are performed. The numerical results are in agreement with the range of values obtained by experimental tests confirming the accuracy of the procedure adopted. The increase of the ankle range of motion after some ligaments rupture is also evaluated, leading to the capability of the numerical models to interpret the damage conditions. The developed computational model provides a tool for the investigation of foot and ankle functionality in terms of stress-strain of the tissues and in terms of ankle motion, considering different types of damage to ankle ligaments.

Decellularized Versus Fresh-Frozen Allografts in Anterior Cruciate Ligament Reconstruction: An In Vitro Study in a Rabbit Model.

PubMed

Dong, Shikui; Huangfu, Xiaoqiao; Xie, Guoming; Zhang, Yang; Shen, Peng; Li, Xiaoxi; Qi, Jin; Zhao, Jinzhong

2015-08-01

The common fresh-frozen allografts that are used for anterior cruciate ligament (ACL) reconstructions behave slower during the remodeling process and produce weaker tendon-bone integrations than do autografts. Decellularization of allogenic tendons results in a clean and porous collagen scaffold with low antigenicity and high compatibility, which may be more suitable for ACL reconstructions. Allograft decellularization will result in a tissue structure with suitable mechanical characteristics for ACL reconstruction, thereby promoting graft remodeling and enhancing tendon-bone healing. Controlled laboratory study. Decellularized allograft tissues were prepared with a pH-modified decellularization process and evaluated for their biocompatibility and biomechanical character in vitro. Eighty New Zealand White rabbits were divided into 2 groups, with 40 in each group, to receive ACL reconstruction with either fresh-frozen (common) allografts or decellularized allografts on both knees. At 2, 4, 8, and 12 weeks postoperatively, the rabbits were euthanized for biomechanical testing, micro-computed tomography analysis, and histologic analysis. The pH-modified decellularized allograft tissues kept excellent biocompatibility and biomechanical character during the in vitro study. Biomechanical testing indicated that the decellularized allograft had significantly higher ultimate load (P = .02) and stiffness (P = .01) levels than the common allograft at 12 weeks, and there was no significant difference between the 2 groups at any other time point. The micro-CT evaluation determined significantly higher bone mineral density (P < .01) in the decellularized allograft group than that in the common allograft group at 12 weeks, but no difference between the 2 groups was observed at any other time point. Regarding bone volume/total volume, there was no difference between the 2 groups at any time point. Fibroblast ingrowths, vascular formation, and connective tissue formation in the tendon-bone interface were better in the decellularized group within 8 weeks. New bone formation was more common in the decellularized allograft group. The collagen birefringence was restored more quickly in the decellularized allograft group than in the common allograft group at all time points. The use of pH-modified decellularized allografts compared with the common allografts resulted in better cellularity, vascularity, collagen matrix remolding, new bone formation around the graft, enhanced tendon-bone healing, and higher ultimate failure load and stiffness of the graft after ACL reconstruction in the rabbit model. The pH-modified decellularized allograft may be a better graft option than the common fresh-frozen allograft for knee ligament reconstructions. © 2015 The Author(s).

Stem cells derived from tooth periodontal ligament enhance functional angiogenesis by endothelial cells.

PubMed

Yeasmin, Shamima; Ceccarelli, Jacob; Vigen, Marina; Carrion, Bita; Putnam, Andrew J; Tarle, Susan A; Kaigler, Darnell

2014-04-01

In regenerative medicine approaches involving cell therapy, selection of the appropriate cell type is important in that the cells must directly (differentiation) or indirectly (trophic effects) participate in the regenerative response. Regardless of the mode of action of the cells, angiogenesis underlies the success of these approaches. Stem cells derived from tooth tissues, specifically the periodontal ligament of teeth (periodontal ligament stem cells [PDLSCs]), have recently been identified as a good source of multipotent cells for cell therapies. PDLSCs have demonstrated properties similar to mesenchymal stem cells (MSCs), yet, unlike MSCs, their vascular potential has not been previously demonstrated. Thus, the aim of this study was to determine if PDLSCs could modulate angiogenesis. In comparison to MSCs and stem cells derived from tooth pulp tissues (SHEDs), we first determined if PDLSCs released soluble proangiogenic factors with the capacity to induce vessel formation by endothelial cells (ECs). Next, the ability of PDLSCs to modulate angiogenesis was examined through their cotransplantation with ECs in subcutaneous sites of immunocompromised mice. Finally, the stability of the PDLSC-mediated vasculature was determined through evaluation of the maturity and functionality of the vessels formed following PDLSC transplantation. It was determined that PDLSCs produced appreciable levels of vascular endothelial growth factor and basic fibroblast growth factor-2, and additionally, were able to initiate in vitro angiogenesis of ECs comparable to MSC- and SHED-mediated angiogenesis. In vivo cotransplantation of ECs with PDLSCs significantly (>50% increase) enhanced the number of blood vessels formed relative to transplantation of ECs alone. Finally, vessels formed following PDLSC cotransplantation were more mature and less permeable than those formed after transplantation of EC alone. These data demonstrate for the first time that PDLSCs have vascular potential, which could make them a very attractive cell population for utilization in regenerative cell therapies.

Instrument-assisted cross-fiber massage accelerates knee ligament healing.

PubMed

Loghmani, M Terry; Warden, Stuart J

2009-07-01

Controlled laboratory study. To investigate the effects of instrument-assisted cross-fiber massage (IACFM) on tissue-level healing of knee medial collateral ligament (MCL) injuries. Ligament injuries are common and significant clinical problems for which there are few established interventions. IACFM represents an intervention that may mediate tissue-level healing following ligament injury. Bilateral knee MCL injuries were created in 51 rodents, while 7 rodents were maintained as ligament-intact, control animals. IACFM was commenced 1 week following injury and introduced 3 sessions per week for 1 minute per session. IACFM was introduced unilaterally (IACFM-treated), with the contralateral, injured MCL serving as an internal control (nontreated). Thirty-one injured animals received 9 ACFM treatments, while the remaining 20 injured animals received 30 treatments. Ligament biomechanical properties and morphology were assessed at either 4 or 12 weeks postinjury. IACFM-treated ligaments were 43.1% stronger (P<.05), 39.7% stiffer (P<.01), and could absorb 57.1% more energy before failure (P<.05) than contralateral, injured, nontreated ligaments at 4 weeks postinjury. On histological and scanning electron microscopy assessment, IACFM-treated ligaments appeared to have improved collagen fiber bundle formation and orientation within the scar region than nontreated ligaments. There were minimal differences between IACFM-treated and contralateral, nontreated ligaments at 12 weeks postinjury, although IACFM-treated ligaments were 15.4% stiffer (P<.05). IACFM-accelerated ligament healing, possibly via favorable effects on collagen formation and organization, but had minimal effect on the final outcome of healing. These findings are clinically interesting, as there are few established interventions for ligament injuries, and IACFM is a simple and practical therapy technique. J Orthop Sports Phys Ther 2009;39(7):506-514, Epub 24 February 2009. doi:10.2519/jospt.2009.2997.

The effect of anterior longitudinal ligament resection on lordosis correction during minimally invasive lateral lumbar interbody fusion: Biomechanical and radiographic feasibility of an integrated spacer/plate interbody reconstruction device.

PubMed

Kim, Choll; Harris, Jonathan A; Muzumdar, Aditya; Khalil, Saif; Sclafani, Joseph A; Raiszadeh, Kamshad; Bucklen, Brandon S

2017-03-01

Lateral lumbar interbody fusion is powerful for correcting degenerative conditions, yet sagittal correction remains limited by anterior longitudinal ligament tethering. Although lordosis has been restored via ligament release, biomechanical consequences remain unknown. Investigators examined radiographic and biomechanical of ligament release for restoration of lumbar lordosis. Six fresh-frozen human cadaveric spines (L3-S1) were tested: (Miller et al., 1988) intact; (Battie et al., 1995) 8mm spacer with intact anterior longitudinal ligament; (Cho et al., 2013) 8mm spacer without intact ligament following ligament resection; (Galbusera et al., 2013) 13mm lateral lumbar interbody fusion; (Goldstein et al., 2001) integrated 13mm spacer. Focal lordosis and range of motion were assessed by applying pure moments in flexion-extension, lateral bending, and axial rotation. Cadaveric radiographs showed significant improvement in lordosis correction following ligament resection (P<0.05). The 8mm spacer with ligament construct provided greatest stability relative to intact (P>0.05) but did little to restore lordosis. Ligament release significantly destabilized the spine relative to intact in all modes and 8mm with ligament in lateral bending and axial rotation (P<0.05). Integrated lateral lumbar interbody fusion following ligament resection did not significantly differ from intact or from 8mm with ligament in all testing modes (P>0.05). Lordosis corrected by lateral lumbar interbody fusion can be improved by anterior longitudinal ligament resection, but significant construct instability and potential implant migration/dislodgment may result. This study shows that an added integrated lateral fixation system can significantly improve construct stability. Long-term multicenter studies are needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of Artificial Ligaments with Different Porous Structures on the Migration of BMSCs

PubMed Central

Wang, Chun-Hui; Hou, Wei; Yan, Ming; Guo, Zhong-shang; Wu, Qi; Bi, Long; Han, Yi-Sheng

2015-01-01

Polyethylene terephthalate- (PET-) based artificial ligaments (PET-ALs) are commonly used in anterior cruciate ligament (ACL) reconstruction surgery. The effects of different porous structures on the migration of bone marrow mesenchymal stem cells (BMSCs) on artificial ligaments and the underlying mechanisms are unclear. In this study, a cell migration model was utilized to observe the migration of BMSCs on PET-ALs with different porous structures. A rabbit extra-articular graft-to-bone healing model was applied to investigate the in vivo effects of four types of PET-ALs, and a mechanical test and histological observation were performed at 4 weeks and 12 weeks. The BMSC migration area of the 5A group was significantly larger than that of the other three groups. The migration of BMSCs in the 5A group was abolished by blocking the RhoA/ROCK signaling pathway with Y27632. The in vivo study demonstrated that implantation of 5A significantly improved osseointegration. Our study explicitly demonstrates that the migration ability of BMSCs can be regulated by varying the porous structures of the artificial ligaments and suggests that this regulation is related to the RhoA/ROCK signaling pathway. Artificial ligaments prepared using a proper knitting method and line density may exhibit improved biocompatibility and clinical performance. PMID:26106429

The transcription factor mohawk homeobox regulates homeostasis of the periodontal ligament.

PubMed

Koda, Naoki; Sato, Tempei; Shinohara, Masahiro; Ichinose, Shizuko; Ito, Yoshiaki; Nakamichi, Ryo; Kayama, Tomohiro; Kataoka, Kensuke; Suzuki, Hidetsugu; Moriyama, Keiji; Asahara, Hiroshi

2017-01-15

The periodontal ligament (PDL), which connects the teeth to the alveolar bone, is essential for periodontal tissue homeostasis. Although the significance of the PDL is recognized, molecular mechanisms underlying PDL function are not well known. We report that mohawk homeobox (Mkx), a tendon-specific transcription factor, regulates PDL homeostasis by preventing its degeneration. Mkx is expressed in the mouse PDL at the age of 10 weeks and expression remained at similar levels at 12 months. In Mkx -/- mice, age-dependent expansion of the PDL at the maxillary first molar (M1) furcation area was observed. Transmission electron microscopy (TEM) revealed that Mkx -/- mice presented collagen fibril degeneration in PDL with age, while the collagen fibril diameter gradually increased in Mkx +/+ mice. PDL cells lost their shape in Mkx -/- mice, suggesting changes in PDL properties. Microarray and quantitative polymerase chain reaction (qPCR) analyses of Mkx -/- PDL revealed an increase in osteogenic gene expression and no change in PDL- and inflammatory-related gene expression. Additionally, COL1A1 and COL1A2 were upregulated in Mkx-overexpressing human PDL fibroblasts, whereas osteogenic genes were downregulated. Our results indicate that Mkx prevents PDL degeneration by regulating osteogenesis. © 2017. Published by The Company of Biologists Ltd.

Regulatory role of periodontal ligament fibroblasts for innate immune cell function and differentiation.

PubMed

Konermann, Anna; Stabenow, Dirk; Knolle, Percy A; Held, Stefanie A E; Deschner, James; Jäger, Andreas

2012-10-01

Innate immunity is crucial for an effective host defense against pathogenic microorganisms in periodontal tissues. As periodontal ligament (PDL) cells synthesize immunomodulatory cytokines, the aim of this in vitro study was to investigate whether these cells can interact with innate immune cells. Resting and inflammatory primed (IL-1β, TNF-α, HMGB1) human PDL cells were co-cultured with human monocyte-derived dendritic cells or macrophages. Migration, phenotypic maturation and modulation of phagocytosis of Porphyromonas gingivalis by immune cells were investigated upon co-culture with PDL cells and/or their released soluble factors. PDL cells interacted with immune cells under both non-inflammatory and inflammatory conditions. Immune cell migration was significantly enhanced by co-culture with PDL cells, which also affected their phenotypic maturation both through cell-cell contact and through released soluble mediators. The dendritic cell maturation markers CD83 and CD86 were upregulated as much as both 'alternatively activated' M2 macrophage maturation markers CD23 and CD163. In contrast, the 'classically activated' M1 macrophage maturation marker CD64 was downregulated. Finally, PDL cells significantly enhanced the phagocytosis of Porphyromonas gingivalis by immune cells. Our experiments revealed that PDL cells are not only structural elements of the periodontium, but actively influence immune responses by interaction with innate immune cells.

Biomimetic poly(lactide) based fibrous scaffolds for ligament tissue engineering.

PubMed

Surrao, Denver C; Waldman, Stephen D; Amsden, Brian G

2012-11-01

The aim of this study was to fabricate a fibrous scaffold that closely resembled the micro-structural architecture and mechanical properties of collagen fibres found in the anterior cruciate ligament (ACL). To achieve this aim, fibrous scaffolds were made by electrospinning L-lactide based polymers. L-Lactide was chosen primarily due to its demonstrated biocompatibility, biodegradability and high modulus. The electrospun fibres were collected in tension on a rotating wire mandrel. Upon treating these fibres in a heated aqueous environment, they possessed a crimp-like pattern having a wavelength and amplitude similar to that of native ACL collagen. Of the polymer fibre scaffolds studied, those made from poly(L-lactide-co-D,L-lactide) PLDLA exhibited the highest modulus and were also the most resilient to in vitro hydrolytic degradation, undergoing a slight decrease in modulus compared to the other polymeric fibres over a 6 month period. Bovine fibroblasts seeded on the wavy, crimp-like PLDLA fibres attached, proliferated and deposited extracellular matrix (ECM) molecules on the surface of the fibrous scaffold. In addition, the deposited ECM exhibited bundle formation that resembled the fascicles found in native ACL. These findings demonstrate the importance of replicating the geometric microenvironment in developing effective tissue engineering scaffolds. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Surgical versus functional treatment for acute ruptures of the lateral ligament complex of the ankle in young men: a randomized controlled trial.

PubMed

Pihlajamäki, Harri; Hietaniemi, Kalevi; Paavola, Mika; Visuri, Tuomo; Mattila, Ville M

2010-10-20

Some have recommended surgical treatment of Grade-III lateral ligament injuries in very active individuals with high functional demands on the ankle. The purpose of this study was to establish whether surgery provides better long-term results than functional treatment for acute ruptures of the lateral ligaments of the ankle. Physically active Finnish men (mean age, 20.4 years) with an acute Grade-III lateral ligament rupture of the ankle were randomly allocated to surgical (n = 25) or functional (n = 26) treatment. Ligament injury was confirmed with stress radiographs. Surgical treatment comprised suture repair of the injured ligament(s) within the first week after injury. A below-the-knee plaster cast was worn for six weeks with full weight-bearing. Functional treatment consisted of the use of an Aircast ankle brace for three weeks. The main outcome measures included final follow-up examinations, calculation of an ankle score, stress radiographs, and magnetic resonance imaging scans. Fifteen (60%) of twenty-five surgically treated patients and eighteen (69%) of twenty-six functionally treated patients returned for long-term follow-up (mean duration, fourteen years). All patients in both groups had recovered their preinjury activity level and reported that they could walk and run normally. The prevalence of reinjury was one of fifteen in the surgical group and seven of eighteen in the functional treatment group (risk difference: 32%; 95% confidence interval: 6% to 58%). The mean ankle score did not differ significantly between the groups (mean difference: 8.3 points; 95% confidence interval: -0.03 to 16.6 points). Stress radiographs revealed no difference between groups with regard to the mean anterior drawer (-1 mm in the surgical group and 0 mm in the functional treatment group; mean difference: 0.7 mm; 95% confidence interval: -1.4 to 2.7 mm) or mean tilt angle (0° in both groups; mean difference: 0.1°; 95% confidence interval: -3.2° to 3.5°). Grade-II osteoarthritis was observed on magnetic resonance images of four of the fifteen surgically treated patients and in none of the eighteen functionally treated patients (risk difference: 27%; 95% confidence interval: 4% to 49%). These findings indicate that, in terms of recovery of the preinjury activity level, the long-term results of surgical treatment of acute lateral ligament rupture of the ankle correspond with those of functional treatment. Although surgery appeared to decrease the prevalence of reinjury of the lateral ligaments, there may be an increased risk for the subsequent development of osteoarthritis.

Composition of Mineral Produced by Dental Mesenchymal Stem Cells.

PubMed

Volponi, A A; Gentleman, E; Fatscher, R; Pang, Y W Y; Gentleman, M M; Sharpe, P T

2015-11-01

Mesenchymal stem cells isolated from different dental tissues have been described to have osteogenic/odontogenic-like differentiation capacity, but little attention has been paid to the biochemical composition of the material that each produces. Here, we used Raman spectroscopy to analyze the mineralized materials produced in vitro by different dental cell populations, and we compared them with the biochemical composition of native dental tissues. We show that different dental stem cell populations produce materials that differ in their mineral and matrix composition and that these differ from those of native dental tissues. In vitro, BCMP (bone chip mass population), SCAP (stem cells from apical papilla), and SHED (stem cells from human-exfoliated deciduous teeth) cells produce a more highly mineralized matrix when compared with that produced by PDL (periodontal ligament), DPA (dental pulp adult), and GF (gingival fibroblast) cells. Principal component analyses of Raman spectra further demonstrated that the crystallinity and carbonate substitution environments in the material produced by each cell type varied, with DPA cells, for example, producing a more carbonate-substituted mineral and with SCAP, SHED, and GF cells creating a less crystalline material when compared with other dental stem cells and native tissues. These variations in mineral composition reveal intrinsic differences in the various cell populations, which may in turn affect their specific clinical applications. © International & American Associations for Dental Research 2015.

Papillary fibroblasts differentiate into reticular fibroblasts after prolonged in vitro culture.

PubMed

Janson, David; Saintigny, Gaëlle; Mahé, Christian; El Ghalbzouri, Abdoelwaheb

2013-01-01

The dermis can be divided into two morphologically different layers: the papillary and reticular dermis. Fibroblasts isolated from these layers behave differently when cultured in vitro. During skin ageing, the papillary dermis decreases in volume. Based on the functional differences in vitro, it is hypothesized that the loss of papillary fibroblasts contributes to skin ageing. In this study, we aimed to mimic certain aspects of skin ageing by using high-passage cultures of reticular and papillary fibroblasts and investigated the effect of these cells on skin morphogenesis in reconstructed human skin equivalents. Skin equivalents generated with reticular fibroblasts showed a reduced terminal differentiation and fewer proliferating basal keratinocytes. Aged in vitro papillary fibroblasts had increased expression of biomarkers specific to reticular fibroblasts. The phenotype and morphology of skin equivalents generated with high-passage papillary fibroblasts resembled that of reticular fibroblasts. This demonstrates that papillary fibroblasts can differentiate into reticular fibroblasts in vitro. Therefore, we hypothesize that papillary fibroblasts represent an undifferentiated phenotype, while reticular fibroblasts represent a more differentiated population. The differentiation process could be a new target for anti-skin-ageing strategies. © 2013 John Wiley & Sons A/S.

The preservative effect of Thai propolis extract on the viability of human periodontal ligament cells.

PubMed

Prueksakorn, Attaporn; Puasiri, Subin; Ruangsri, Supanigar; Makeudom, Anupong; Sastraruji, Thanapat; Krisanaprakornkit, Suttichai; Chailertvanitkul, Pattama

2016-12-01

Tooth avulsion causes an injury to the periodontal ligament (PDL). The success of tooth replantation depends on the quantity and quality of PDL cells. The aim of this study was to examine the preservative and proliferative effects of Thai propolis extract, previously shown to exert anti-inflammatory and antioxidant activities, on human PDL cells. Ninety-six premolars were left to air dry for 30 min and stored in Hank's balanced salt solution (HBSS), milk, or various concentrations of propolis extract from 0.25 to 10 mg ml -1 for 3 h. PDL cells were isolated by collagenase and trypsin digestion, and their viability was determined by a trypan blue dye exclusion assay. PDL tissues were also scraped off the root surface and cultured to determine cell growth and morphology. The alamarBlue ® and BrdU assays were performed to determine the cytotoxic and proliferative effects of the extract on cultured PDL cells, respectively. A non-toxic dose of 2.5 mg ml -1 of propolis extract yielded the greatest percentage of cell viability (78.84 ± 3.34%), which was significantly higher than those of the other concentrations (P < 0.001). Nevertheless, this percentage was not significantly different from that of HBSS (80.14 ± 2.44%; P = 1.00), but was significantly higher than that of milk (71.27 ± 2.79%; P < 0.001). The cells grown from PDL explants looked like fibroblasts. However, 2.5 mg ml -1 of the extract did not induce PDL cell proliferation. Thai propolis extract at 2.5 mg ml -1 appears to be the most effective dose for preserving the viability of PDL cells, and this was comparable to HBSS. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cytotoxicity and Initial Biocompatibility of Endodontic Biomaterials (MTA and Biodentine™) Used as Root-End Filling Materials.

PubMed

Escobar-García, Diana María; Aguirre-López, Eva; Méndez-González, Verónica; Pozos-Guillén, Amaury

2016-01-01

Objective. The aim of this study was to evaluate the cytotoxicity and cellular adhesion of Mineral Trioxide Aggregate (MTA) and Biodentine (BD) on periodontal ligament fibroblasts (PDL). Methods. PDL cells were obtained from nonerupted third molars and cultured; MTS cellular profusion test was carried out in two groups: MTA and BD, with respective controls at different time periods. Also, the LIVE/DEAD assay was performed at 24 h. For evaluation of cellular adhesion, immunocytochemistry was conducted to discern the expression of Integrin β1 and Vinculin at 12 h and 24 h. Statistical analysis was performed by the Kruskal-Wallis and Mann-Whitney U tests. Results. MTA and BD exhibited living cells up to 7 days. More expressions of Integrin β1 and Vinculin were demonstrated in the control group, followed by BD and MTA, which also showed cellular loss and morphological changes. There was a significant difference in the experimental groups cultured for 5 and 7 days compared with the control, but there was no significant statistical difference between both cements. Conclusions. Neither material was cytotoxic during the time evaluated. There was an increase of cell adhesion through the expression of focal contacts observed in the case of BD, followed by MTA, but not significantly.

Ligament of Barkow of the craniocervical junction: its anatomy and potential clinical and functional significance.

PubMed

Tubbs, R Shane; Dixon, Joshua; Loukas, Marios; Shoja, Mohammadali M; Cohen-Gadol, Aaron A

2010-06-01

Knowledge of the anatomy of the ligaments that unite the head with the neck is important to the clinician who treats patients with lesions in this region. Although the anatomy and function of these ligaments have been well described, those of the Barkow ligament (BL) have yet to be studied. Via an anterior approach, 13 unembalmed adult cadavers underwent dissection of the craniocervical junction with special attention to the presence, anatomy, and function of the BL. The BL was found in 92.3% of specimens. The attachment of each ligament onto the medial aspect of the occipital condyle was consistent and just anterior to the attachment of the alar ligaments. In 75% of specimens, there was some connection between the BL and the anterior atlantooccipital membrane. Connections between other adjacent ligamentous structures were not identified. The average width, length, and thickness of the BL were 4, 2.5, and 3.5 mm, respectively. With ranges of motion of the craniocervical junction, only extension of the atlantooccipital joint produced tension in the BL. The mean tension to failure of the ligament was 28 N. Statistical analysis revealed no significant difference in width, length, and thickness of the ligaments based on sex. The BL was found in all but 1 of our specimens. This ligament appears to resist extension of the atlantooccipital joint and may be synergistic with the anterior atlantooccipital membrane. Interestingly, the function of this ligament as found in this study relies on the integrity of the transverse ligament. Knowledge of this ligament may aid in further understanding craniocervical stability and help in differentiating normal from pathological tissue using imaging modalities.

Strain Distribution in the Anterior Inferior Tibiofibular Ligament, Posterior Inferior Tibiofibular Ligament, and Interosseous Membrane Using Digital Image Correlation.

PubMed

Xu, Daorong; Wang, Yibei; Jiang, Chunyu; Fu, Maoqing; Li, Shiqi; Qian, Lei; Sun, Peidong; Ouyang, Jun

2018-05-01

Ligament repair and augmentation techniques can stabilize syndesmosis injuries. However, little is known about the mechanical behavior of syndesmotic ligaments. The aim of this study was to analyze full-field strain, strain trend under foot rotation, and subregional strain differences of the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), and interosseous membrane (IOM). Eleven fresh-frozen lower limbs were dissected to expose the AITFL, PITFL, and IOM. The foot underwent rotation from 0° to 25° internal and 35° external, with 3 ankle positions (neutral, 15° dorsiflexion, and 25° plantarflexion) and a vertical load of 430 N. Ligament strain was recorded using digital image correlation. The mean strain on the AITFL with 35° external rotation was greater in the proximal portion compared with distal portion in the neutral position ( P = .009) and dorsiflexion ( P = .003). The mean strain in the tibial insertion and midsubstance near tibial insertion were greater when compared with other regions ( P = .018 and P = .009). The subregions of mean strain in the PITFL and IOM groups were not significantly different. The strain trend of AITFL, PITFL, and IOM showed common transformation, just when the foot was externally rotated. The findings of this study show that a significantly high strain was observed on the proximal part and the midsubstance near the Chaput tubercle of the AITFL when the ankle was externally rotated. All 3 ligaments resisted the torque in the syndesmosis by external rotation of the foot. This study allows for better understanding of the mechanical behavior of the syndesmosis ligaments, which could influence the repair technique and AITFL augmentation techniques.

Addition of autologous mesenchymal stem cells to whole blood for bioenhanced ACL repair has no benefit in the porcine model.

PubMed

Proffen, Benedikt L; Vavken, Patrick; Haslauer, Carla M; Fleming, Braden C; Harris, Chad E; Machan, Jason T; Murray, Martha M

2015-02-01

Coculture of mesenchymal stem cells (MSCs) from the retropatellar fat pad and peripheral blood has been shown to stimulate anterior cruciate ligament (ACL) fibroblast proliferation and collagen production in vitro. Current techniques of bioenhanced ACL repair in animal studies involve adding a biologic scaffold, in this case an extracellular matrix-based scaffold saturated with autologous whole blood, to a simple suture repair of the ligament. Whether the enrichment of whole blood with MSCs would further improve the in vivo results of bioenhanced ACL repair was investigated. The addition of MSCs derived from adipose tissue or peripheral blood to the blood-extracellular matrix composite, which is used in bioenhanced ACL repair to stimulate healing, would improve the biomechanical properties of a bioenhanced ACL repair after 15 weeks of healing. Controlled laboratory study. Twenty-four adolescent Yucatan mini-pigs underwent ACL transection followed by (1) bioenhanced ACL repair, (2) bioenhanced ACL repair with the addition of autologous adipose-derived MSCs, and (3) bioenhanced ACL repair with the addition of autologous peripheral blood derived MSCs. After 15 weeks of healing, the structural properties of the ACL (yield load, failure load, and linear stiffness) were measured. Cell and vascular density were measured in the repaired ACL via histology, and its tissue structure was qualitatively evaluated using the advanced Ligament Maturity Index. After 15 weeks of healing, there were no significant improvements in the biomechanical or histological properties with the addition of adipose-derived MSCs. The only significant change with the addition of peripheral blood MSCs was an increase in knee anteroposterior laxity when measured at 30° of flexion. These findings suggest that the addition of adipose or peripheral blood MSCs to whole blood before saturation of an extracellular matrix carrier with the blood did not improve the functional results of bioenhanced ACL repair after 15 weeks of healing in the pig model. Whole blood represents a practical biologic additive to ligament repair, and any other additive (including stem cells) should be demonstrated to be superior to this baseline before clinical use is considered. © 2014 The Author(s).

Influence of the thickness of the transverse carpal ligament in carpal tunnel syndrome.

PubMed

Bartolomé-Villar, A; Pastor-Valero, T; Fuentes-Sanz, A; Varillas-Delgado, D; García-de Lucas, F

To determine if the thickness of the transverse carpal ligament measured by T2 axial magnetic resonance imaging actually influences the onset of carpal tunnel syndrome. 94 patients between January 2015 and June 2016, of whom 28 had carpal tunnel syndrome, underwent magnetic resonance imaging, 37 with discomfort in different carpus regions without symptoms of carpal tunnel and 29 healthy subjects. Two observers performed 3 measurements in 3 different levels, and in the 3 groups of patients. No statistically significant differences in transverse carpal ligament thickness measurements between the carpal tunnel syndrome group and the group without carpal tunnel involvement became apparent, but statistical differences between the control group and the carpal tunnel syndrome group, and between the control group and the group without involvement of the carpal tunnel were observed. In both these groups, the thickness of the transverse ligament was higher than in the control group. An increase in the thickness of the transverse ligament in was found in this study in subjects with involvement of carpal tunnel syndrome as evidenced by numerous studies in the literature. There is no certain causative factor, but rather a set of facts that make onset of the syndrome possible in a specific group of patients. Carpal tunnel syndrome is multifactorial. The thickness of the transverse ligament does not directly affect the onset of symptoms. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Characterization and cytotoxicity of ions released from stainless steel and nickel-titanium orthodontic alloys.

PubMed

Eliades, Theodore; Pratsinis, Harris; Kletsas, Dimitris; Eliades, George; Makou, Margarita

2004-01-01

The purpose of this study was to qualitatively and quantitatively characterize the substances released from orthodontic brackets and nickel-titanium wires and to comparatively assess the cytotoxicity of the ions released from these orthodontic alloys. Two full sets of stainless steel brackets of 20 brackets each (weight 2.1 g) and 2 groups of 0.018 x 0.025 Ni-Ti archwires of 10 wires each (weight 2.0 g) were immersed in 0.9% saline solution for a month. The immersion media were analyzed with inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and the ionic content was statistically analyzed with 1-way analysis of variance (ANOVA). Human periodontal ligament fibroblasts and gingival fibroblasts were exposed to various concentrations of the 2 immersion media; nickel chloride was used as a positive control for comparison purposes. The cytotoxic or cytostatic activity of the media was investigated with the MTT and the DNA synthesis assays. The results of the cytotoxicity assay were analyzed with 2-way ANOVA and the Tukey test with solution and concentration variants as discriminating variables (alpha=0.05). The results indicated no ionic release for the nickel-titanium alloy aging solution, whereas measurable nickel and traces of chromium were found in the stainless steel bracket-aging medium. Concentrations of the nickel chloride solution greater then 2 mM were found to reduce by more than 50% the viability and DNA synthesis of fibroblasts; however, neither orthodontic materials-derived media had any effect on the survival and DNA synthesis of either cells.

Immunohistochemical Mapping of Sensory Nerve Endings in the Human Triangular Fibrocartilage Complex.

PubMed

Rein, Susanne; Semisch, Manuel; Garcia-Elias, Marc; Lluch, Alex; Zwipp, Hans; Hagert, Elisabet

2015-10-01

The triangular fibrocartilage complex is the main stabilizer of the distal radioulnar joint. While static joint stability is constituted by osseous and ligamentous integrity, the dynamic aspects of joint stability chiefly concern proprioceptive control of the compressive and directional muscular forces acting on the joint. Therefore, an investigation of the pattern and types of sensory nerve endings gives more insight in dynamic distal radioulnar joint stability. We aimed to (1) analyze the general distribution of sensory nerve endings and blood vessels; (2) examine interstructural distribution of sensory nerve endings and blood vessels; (3) compare the number and types of mechanoreceptors in each part; and (4) analyze intrastructural distribution of nerve endings at different tissue depth. The subsheath of the extensor carpi ulnaris tendon sheath, the ulnocarpal meniscoid, the articular disc, the dorsal and volar radioulnar ligaments, and the ulnolunate and ulnotriquetral ligaments were dissected from 11 human cadaver wrists. Sensory nerve endings were counted in five levels per specimen as total cell amount/cm(2) after staining with low-affinity neurotrophin receptor p75, protein gene product 9.5, and S-100 protein and thereafter classified according to Freeman and Wyke. All types of sensory corpuscles were found in the various structures of the triangular fibrocartilage complex with the exception of the ulnolunate ligament, which contained only Golgi-like endings, free nerve endings, and unclassifiable corpuscles. The articular disc had only free nerve endings. Furthermore, free nerve endings were the predominant sensory nerve ending (median, 72.6/cm(2); range, 0-469.4/cm(2)) and more prevalent than all other types of mechanoreceptors: Ruffini (median, 0; range, 0-5.6/cm(2); difference of medians, 72.6; p < 0.001), Pacini (median, 0; range, 0-3.8/cm(2); difference of medians, 72.6; p < 0.001), Golgi-like (median, 0; range, 0-2.1/cm(2); difference of medians, 72.6; p < 0.001), and unclassifiable corpuscles (median, 0; range, 0-2.5/cm(2); difference of medians, 72.6; p < 0.001). The articular disc contained fewer free nerve endings (median, 1.8; range, 0-17.8/cm(2)) and fewer blood vessels (median, 29.8; range, 0-112.2/cm(2); difference of medians: 255.9) than all other structures of the triangular fibrocartilage complex (p ≤ 0.001, respectively) except the ulnolunate ligament. More blood vessels were seen in the volar radioulnar ligament (median, 363.62; range, 117.8-871.8/cm(2)) compared with the ulnolunate ligament (median, 107.7; range, 15.9-410.3/cm(2); difference of medians: 255.91; p = 0.002) and the dorsal radioulnar ligament (median, 116.2; range, 53.9-185.1/cm(2); difference of medians: 247.47; p = 0.001). Free nerve endings were obtained in each structure more often than all other types of sensory nerve endings (p < 0.001, respectively). The intrastructural analysis revealed no differences in mechanoreceptor distribution in all investigated specimens with the numbers available, showing a homogenous distribution of proprioceptive qualities in all seven parts of the triangular fibrocartilage complex. Nociception has a primary proprioceptive role in the neuromuscular stability of the distal radioulnar joint. The articular disc and ulnolunate ligament rarely are innervated, which implies mainly mechanical functions, whereas all other structures have pronounced proprioceptive qualities, prerequisite for dynamic joint stability. Lesions of the volar and dorsal radioulnar ligaments have immense consequences not only for mechanical but also for dynamic stability of the distal radioulnar joint, and surgical reconstruction in instances of radioulnar ligament injury is important.

Comparison of complete distal release of the medial collateral ligament and medial epicondylar osteotomy during ligament balancing in varus knee total knee arthroplasty.

PubMed

Sim, Jae Ang; Lee, Yong Seuk; Kwak, Ji Hoon; Yang, Sang Hoon; Kim, Kwang Hui; Lee, Beom Koo

2013-12-01

During ligament balancing for severe medial contracture in varus knee total knee arthroplasty (TKA), complete distal release of the medial collateral ligament (MCL) or a medial epicondylar osteotomy can be necessary if a large amount of correction is needed. This study retrospectively reviewed 9 cases of complete distal release of the MCL and 11 cases of medial epicondylar osteotomy which were used to correct severe medial contracture. The mean follow-up periods were 46.5 months (range, 36 to 78 months) and 39.8 months (range, 32 to 65 months), respectively. There were no significant differences in the clinical results between the two groups. However, the valgus stress radiograph revealed significant differences in medial instability. In complete distal release of the MCL, some stability was obtained by repair and bracing but the medial instability could not be removed completely. Medial epicondylar osteotomy for a varus deformity in TKA could provide constant medial stability and be a useful ligament balancing technique.

Elastin in the human intervertebral disk. A histological and biochemical study comparing it with elastin in the human yellow ligament.

PubMed

Mikawa, Y; Hamagami, H; Shikata, J; Yamamuro, T

1986-01-01

The elastic fiber and elastin in the human yellow ligament and intervertebral disk were studied histologically and biochemically. The elastic fiber in the human intervertebral disk, which until now had not been clearly identified microscopically, was observed clearly. We found the distribution of the elastic fiber in the intervertebral disk to be very sparse and irregular, and its diameter was small, being about one-tenth of that found in the yellow ligament. The elastin contents of the yellow ligament and intervertebral disk were 46.7% +/- 0.9% and 1.7% +/- 0.2% respectively (mean +/- SE) of the total dry weight. The amino acid composition of elastin in the yellow ligament is similar to that of other tissue, as reported in the literature; however, that found in the intervertebral disk is significantly different. It would appear, therefore, that the elastin in the intervertebral disk is of a different type from that found elsewhere.

PT-12, a putative ras-activated proliferation-dependent gene, is expressed in patellar tendon and not in anterior cruciate ligament.

PubMed

Goomer, R S; Maris, T; Ostrander, R; Amiel, D

1999-09-01

We describe a gene (PT-12) that is expressed in the patellar tendon and not in the anterior cruciate ligament. We used a recently developed polymerase chain reaction-based subtractive cDNA analysis to discover genes that are overexpressed in the patellar tendon but not expressed in the anterior cruciate ligament; the long-term objective was to find genes that are central to the self-repair of the patellar tendon, in contrast with the inability of the anterior cruciate ligament to launch a repair response following injury. PT-12 is a homologue of human S2 or mouse LLRep3 ribosomal genes, which are known to be overexpressed in highly proliferating cells. This study opens a new vista to the development of techniques and reagents to study the differences between two periarticular tissues (i.e., the patellar tendon and anterior cruciate ligament) that differ primarily in their ability to self-repair.

Trends in Materials Science for Ligament Reconstruction.

PubMed

Sava, Oana Roxana; Sava, Daniel Florin; Radulescu, Marius; Albu, Madalina Georgiana; Ficai, Denisa; Veloz-Castillo, Maria Fernanda; Mendez-Rojas, Miguel Angel; Ficai, Anton

2017-01-01

The number of ligament injuries increases every year and concomitantly the need for materials or systems that can reconstruct the ligament. Limitations imposed by autografts and allografts in ligament reconstruction together with the advances in materials science and biology have attracted a lot of interest for developing systems and materials for ligament replacement or reconstruction. This review intends to synthesize the major steps taken in the development of polymer-based materials for anterior cruciate ligament, their advantages and drawbacks and the results of different in vitro and in vivo tests. Until present, there is no successful polymer system for ligament reconstruction implanted in humans. The developing field of synthetic polymers for ligament reconstruction still has a lot of potential. In addition, several nano-structured materials, made of nanofibers or in the form of ceramic/polymeric nanocomposites, are attracting the interest of several groups due to their potential use as engineered scaffolds that mimic the native environment of cells, increasing the chances for tissue regeneration. Here, we review the last 15 years of literature in order to obtain a better understanding on the state-of-the-art that includes the usage of nano- and poly-meric materials for ligament reconstruction, and to draw perspectives on the future development of the field. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

[Rehabilitation after anterior cruciate ligament suturing].

PubMed

Andrtová, M; Chlupatá, I

1994-01-01

The authors discuss problems of rehabilitation after suture of the anterior cruciate ligament where frequently errors are committed and where inadequate rehabilitation may cause damage to the patient. Different periods of rehabilitation after LCA sutures are discussed and suitable methods of exercise for different periods are recommended.

Specialisation of extracellular matrix for function in tendons and ligaments

PubMed Central

Birch, Helen L.; Thorpe, Chavaunne T.; Rumian, Adam P.

2013-01-01

Summary Tendons and ligaments are similar structures in terms of their composition, organisation and mechanical properties. The distinction between them stems from their anatomical location; tendons form a link between muscle and bone while ligaments link bones to bones. A range of overlapping functions can be assigned to tendon and ligaments and each structure has specific mechanical properties which appear to be suited for particular in vivo function. The extracellular matrix in tendon and ligament varies in accordance with function, providing appropriate mechanical properties. The most useful framework in which to consider extracellular matrix differences therefore is that of function rather than anatomical location. In this review we discuss what is known about the relationship between functional requirements, structural properties from molecular to gross level, cellular gene expression and matrix turnover. The relevance of this information is considered by reviewing clinical aspects of tendon and ligament repair and reconstructive procedures. PMID:23885341

The ligaments of the canine hip joint revisited.

PubMed

Casteleyn, C; den Ouden, I; Coopman, F; Verhoeven, G; Van Cruchten, S; Van Ginneken, C; Van Ryssen, B; Simoens, P

2015-12-01

Numerous conventional anatomical textbooks describe the canine hip joint, but many contradictions, in particular regarding the ligament of the femoral head, are present. This paper presents a brief overview of the different literature descriptions. These are compared with own observations that have resulted in a revised description of the anatomy of the ligament of the femoral head in the dog. To this purpose, the hip joints of 41 dogs, euthanized for reasons not related to this study and devoid of lesions related to hip joint pathology, were examined. It was observed that the ligament of the femoral head is not a single structure that attaches only to the acetabular fossa, as generally accepted, but it also connects to the transverse acetabular ligament and is complemented by a strong accessory ligament that courses in caudal direction to attach in the elongation of the acetabular notch that extends on the cranioventral surface of the body of the ischium. The description of this accessory ligament in conventional anatomical handbooks is incomplete. This description of the accessory ligament of the femoral head could support the research unravelling the etiopathogenesis of hip instability. © 2014 Blackwell Verlag GmbH.

Substance P and Calcitonin gene-related peptide expression in human periodontal ligament after root canal preparation with Reciproc Blue, WaveOne Gold, XP EndoShaper and hand files.

PubMed

Caviedes-Bucheli, J; Rios-Osorio, N; Rey-Rojas, M; Laguna-Rivero, F; Azuero-Holguin, M M; Diaz, L E; Curtidor, H; Castaneda-Ramirez, J J; Munoz, H R

2018-05-17

To quantify Substance P (SP) and Calcitonin gene-related peptide (CGRP) expression in healthy human periodontal ligament from premolars after root canal preparation with Reciproc Blue, WaveOne Gold, XP EndoShaper and hand files. A total of 50 human periodontal ligament samples were obtained from healthy mandibular premolars where extraction was indicated for orthodontic reasons. Prior to extraction, 40 of these premolars were equally divided into four groups, and root canals were prepared using four different systems: Reciproc Blue, WaveOne Gold, XP EndoShaper and a hand instrumentation technique. The remaining 10 healthy premolars were extracted without treatment and served as a negative control group. All periodontal ligament samples were processed, and SP and CGRP were measured by radioimmunoassay. The Kruskal-Wallis test was used to establish significant differences between groups and LSD post hoc comparisons were also performed. Greater SP and CGRP values were found in the hand instrumentation group, followed by the XP EndoShaper, WaveOne Gold and the Reciproc groups. The lower SP and CGRP values were for the healthy periodontal ligament group. The Kruskal-Wallis test revealed significant differences between groups (P < 0.05). Post hoc Least Significant Difference (LSD) tests revealed significant differences (P < 0.05) in SP and CGRP expression between all the comparisons except for the Reciproc Blue and WaveOne Gold group (P > 0.05). All the root canal preparation techniques tested increased SP and CGRP expression in human periodontal ligament, with hand files and XP EndoShaper instruments being associated with greater neuropeptide release compared to Reciproc Blue and WaveOne Gold files. © 2018 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Does C₁ fracture displacement correlate with transverse ligament integrity?

PubMed

Radcliff, Kristen E; Sonagli, Marcos A; Rodrigues, Luciano M; Sidhu, Gursukhman S; Albert, Todd J; Vaccaro, Alexander R

2013-05-01

The Rule of Spence states that displacement of the C₁ lateral masses by >6.9-8.1 mm suggests loss of transverse ligament integrity. The purpose of this study was to establish the thresholds of C₁ displacement on CT scans that correspond to transverse ligament disruption. Over four years, consecutive patients with acute C₁ fractures with at least three fracture lines were analyzed. CT measurements and MRI were assessed by blinded observers for bony displacement in the axial (internal and external lateral mass separation), coronal and sagittal planes and transverse ligament integrity. Eighteen patients were studied. Mean CT bony measurements were as follows: internal border lateral mass separation (ILM) 23.3 ± 3.4 mm, external border lateral mass separation (ELM) 50.3 ± 4.3 mm, total C₁ lateral mass overhang over the C₂ superior process (LMO) 5.4 ± 1.3 mm. Twelve patients were identified as having intact transverse ligament and six had transverse ligament disruption. There was no difference in mean normalized ILM, ELM, or LMO between patients with or without transverse ligament integrity (P > 0.05). There was no correlation between bony displacement and transverse ligament integrity. CT scans post-injury may not show the position of maximal displacement. If there is clinical concern about a possible transverse ligament injury, MRI should be performed. © 2013 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

Sex-Based Differences of Medial Collateral Ligament and Anterior Cruciate Ligament Strains With Cadaveric Impact Simulations.

PubMed

Schilaty, Nathan D; Bates, Nathaniel A; Nagelli, Christopher V; Krych, Aaron J; Hewett, Timothy E

2018-04-01

Female patients sustain noncontact knee ligament injuries at a greater rate compared with their male counterparts. The cause of these differences in the injury rate and the movements that load the ligaments until failure are still under dispute in the literature. This study was designed to determine differences in anterior cruciate ligament (ACL) and medial collateral ligament (MCL) strains between male and female cadaveric specimens during a simulated athletic task. The primary hypothesis tested was that female limbs would demonstrate significantly greater ACL strain compared with male limbs under similar loading conditions. A secondary hypothesis was that MCL strain would not differ between sexes. Controlled laboratory study. Motion analysis of 67 athletes performing a drop vertical jump was conducted. Kinetic data were used to categorize injury risk according to tertiles, and these values were input into a cadaveric impact simulator to assess ligamentous strain during a simulated landing task. Uniaxial and multiaxial load cells and differential variable reluctance transducer strain sensors were utilized to collect mechanical data for analysis. Conditions of external loads applied to the cadaveric limbs (knee abduction moment, anterior tibial shear, and internal tibial rotation) were varied and randomized. Data were analyzed using 1-way analysis of variance (ANOVA), 2-way repeated-measures ANOVA, and the Fisher exact test. There were no significant differences ( P = .184) in maximum ACL strain between male (13.2% ± 8.1%) and female (16.7% ± 8.3%) specimens. Two-way ANOVA demonstrated that across all controlled external load conditions, female specimens consistently attained at least 3.5% increased maximum ACL strain compared with male specimens ( F 1,100 = 4.188, P = .043); however, when normalized to initial contact, no significant difference was found. There were no significant differences in MCL strain between sexes for similar parameters. When compared with baseline, female specimens exhibited greater values of ACL strain at maximum, initial contact, and after impact (33, 66, and 100 milliseconds, respectively) than male specimens during similar loading conditions, with a maximum strain difference of at least 3.5%. During these same loading conditions, there were no differences in MCL loading between sexes, and only a minimal increase of MCL loading occurred during the impact forces. Our results indicate that female patients are at an increased risk for ACL strain across all similar conditions compared with male patients. These data demonstrate that female specimens, when loaded similarly to male specimens, experience additional strain on the ACL. As the mechanical environment was similar for both sexes with these simulations, the greater ACL strain of female specimens must be attributed to ligament biology, anatomic differences, or muscular stiffness.

Biomechanical evaluation of native acromioclavicular joint ligaments and two reconstruction techniques in the presence of the sternoclavicular joint: A cadaver study.

PubMed

Masionis, Povilas; Šatkauskas, Igoris; Mikelevičius, Vytautas; Ryliškis, Sigitas; Bučinskas, Vytautas; Griškevičius, Julius; Martin Oliva, Xavier; Monzó Planella, Mariano; Porvaneckas, Narūnas; Uvarovas, Valentinas

2017-01-01

Where is over 100 reconstruction techniques described for acromioclavicular (AC) joint reconstruction. Although, it is not clear whether the presence of the sternoclavicular (SC) joint influences the biomechanical properties of native AC ligaments and reconstruction techniques. The purpose of the present study was to investigate the biomechanical properties of native AC joint ligaments and two reconstruction techniques in cadavers with the SC joint still present. We tested eight fresh-frozen cadaver hemithoraces for superior translation (70 N load) and translation increment after 1000 cycles (loading from 20 to 70 N) in a controlled laboratory study. There were three testing groups created: native ligaments, the single coracoclavicular loop (SCL) technique, and the two coracoclavicular loops (TCL) technique. Superior translation was measured after static loading. Translation increment was calculated as the difference between superior translation after cyclic and static loading. Native AC ligaments showed significantly lower translation than the SCL ( p = 0.023) and TCL ( p = 0.046) groups. The SCL had a significantly lower translation increment than native AC ligaments ( p = 0.028). There was no significant difference between reconstruction techniques in terms of translation ( p = 0.865) and translation increment ( p = 0.113). Native AC joint ligaments had better static properties than both reconstruction techniques and worse dynamic biomechanical properties than the SCL technique. The SCL technique appeared to be more secure than the TCL technique. The presence of the SC joint did not have an observable influence on test results.

Does a balance deficit persist in Australian Football players with previous lower limb ligament injury?

PubMed

Hrysomallis, C; McLaughlin, P; Goodman, C

2005-03-01

A history of lower limb ligament injury is a commonly-cited risk factor for another similar injury. During the acute phase of injury, there is a balancing skill deficit in the injured limb. It has been unclear as to whether this deficit persists in the medium-to-long term for previously injured Australian footballers, contributing to the risk of re-injury. This study compared the balance ability of footballers with and without previous lower limb ligament injury and, for previously injured players, the balance ability of the previously injured limb to the opposite uninjured limb. A total of 216 players from 6 teams from the Australian Football League were tested. The balance task comprised stepping on to a foam mat on top of a force plate and maintaining one-legged balance. The subjects were divided into 4 groups based on their injury history: all ankle injuries to only one limb, recent ankle injuries to only one limb (within the last 12 months), knee ligament injury only to one limb, and no previous ankle or knee ligament injury. Statistical analysis revealed that there was no significant difference between the balance scores of any of the previously injured players and those with no previous lower limb ligament injury. There was no significant difference between the balance score of the previously injured limb with the opposite uninjured limb. It appears that a balance deficit does not persist in Australian Football players with previous lower limb ligament injury.

Different roles of the medial and lateral hamstrings in unloading the anterior cruciate ligament.

PubMed

Guelich, David R; Xu, Dali; Koh, Jason L; Nuber, Gordon W; Zhang, Li-Qun

2016-01-01

Anterior cruciate ligament injuries are closely associated with excessive loading and motion about the off axes of the knee, i.e. tibial rotation and knee varus/valgus. However, it is not clear about the 3-D mechanical actions of the lateral and medial hamstring muscles and their differences in loading the ACL. The purpose of this study was to investigate the change in anterior cruciate ligament strain induced by loading the lateral and medial hamstrings individually. Seven cadaveric knees were investigated using a custom testing apparatus allowing for six degree-of-freedom tibiofemoral motion induced by individual muscle loading. With major muscles crossing the knee loaded moderately, the medial and lateral hamstrings were loaded independently to 200N along their lines of actions at 0°, 30°, 60° and 90° of knee flexion. The induced strain of the anterior cruciate ligament was measured using a differential variable reluctance transducer. Tibiofemoral kinematics was monitored using a six degrees-of-freedom knee goniometer. Loading the lateral hamstrings induced significantly more anterior cruciate ligament strain reduction (mean 0.764 [SD 0.63] %) than loading the medial hamstrings (mean 0.007 [0.2] %), (P=0.001 and effect size=0.837) across the knee flexion angles. The lateral and medial hamstrings have significantly different effects on anterior cruciate ligament loadings. More effective rehabilitation and training strategies may be developed to strengthen the lateral and medial hamstrings selectively and differentially to reduce anterior cruciate ligament injury and improve post-injury rehabilitation. The lateral and medial hamstrings can potentially be strengthened selectively and differentially as a more focused rehabilitation approach to reduce ACL injury and improve post-injury rehabilitation. Different ACL reconstruction procedures with some of them involving the medial hamstrings can be compared to each other for their effect on ACL loading. Copyright © 2015 Elsevier B.V. All rights reserved.

Biomechanical consequences of a posterior root tear of the lateral meniscus: stabilizing effect of the meniscofemoral ligament.

PubMed

Forkel, Philipp; Herbort, Mirco; Schulze, Martin; Rosenbaum, Dieter; Kirstein, Lars; Raschke, Michael; Petersen, Wolf

2013-05-01

The purpose of this study was to evaluate the effects of different types of lateral meniscus root tears in terms of tibiofemoral contact stress. Ten porcine knees each underwent five different testing conditions with the menisci intact, a simulated lateral posterior root tear with and without cutting the meniscofemoral ligament and with an artificial tear of the posterior root of the medial meniscus. Biomechanical testing was performed at 30° of flexion with an axial load of 100 N. A pressure sensor (st Sensor Type S2042, Novel, Munich) was used to measure the tibiofemoral contact area and the tibiofemoral contact pressure. Data were analyzed to assess the differences in contact area and tibiofemoral peak contact pressure among the five meniscal conditions. There was no significant difference in mean contact pressure between the state with the menisci intact and an isolated posterior root tear of the lateral meniscus. In case of a root tear and a tear of the meniscofemoral ligament, the contact area decreased in comparison with the intact state of the menisci. After additional cutting of the meniscofemoral ligament, the tibiofemoral contact pressure was significantly higher in comparison with the intact state and the avulsion injury. In the medial compartment, joint compression forces were significantly increased in comparison with the intact state after cutting the posterior root of the medial meniscus (P < 0.05). The consequence of a medial meniscus root tear is well known and was verified by this analysis. The results of the present study show that the biomechanical consequences of a lateral meniscus root tear depend on the state of the meniscofemoral ligament. An increase in tibiofemoral contact pressure is only to be expected in combined injuries of the meniscus root and the meniscofemoral ligaments. Posterior lateral meniscus root tear might have a better prognosis in terms of the development of osteoarthritis when the meniscofemoral ligament is intact.

Comparative anatomy and biomechanical properties of atlantoaxial ligaments in equine, bovine, and canine cadaveric specimens.

PubMed

Forterre, Franck; Stoffel, Michael H; Koch, Christoph; Precht, Christina; Waschk, Maja; Bürki, Alexander

2017-05-22

Atlantoaxial instability has been reported in humans, dogs, equids and ruminants. The functional role of the atlantoaxial ligaments has only been described rudimentarily in equids and ruminants. The goal of the present cadaveric study was to compare the anatomy between the different species and to comparatively assess the role of the stabilizing ligaments of the atlantoaxial joint under sagittal shear loading in canine, equine, and bovine cervical spines. Three equine, bovine, and canine cadaveric specimens were investigated. Biomechanical testing was performed using a purpose built shear-testing device driven by a uniaxial servo-hydraulic testing machine. Three cycles in a dorsoventral direction with a constant quasi-static velocity of 0.2 mm/s up to a limiting force of 50 N (canine) or 250 N (bovine, equine), respectively, were performed for each specimen tested. Load and linear displacement were measured by the displacement sensor and load cell of the testing system at a sampling rate of 20 Hz. Tests were performed and the range of motion determined with both intact and transected atlantoaxial ligaments. The range of motion was significantly increased after transection of the ligaments only in the canine specimens. The bovine atlantoaxial joint was biomechanically more stable than in equids. Species-specific anatomical and biomechanical differences of the atlantoaxial ligaments in canines, equids, and bovines were detected. The significance of these differences and their impact on the pathogenesis of atlantoaxial subluxations and subsequent treatment remain open questions.

Can Intraoperative Sensors Determine the "Target" Ligament Balance? Early Outcomes in Total Knee Arthroplasty.

PubMed

Meneghini, Robert M; Ziemba-Davis, Mary M; Lovro, Luke R; Ireland, Phillip H; Damer, Brent M

2016-10-01

The optimal "target" ligament balance for each patient undergoing total knee arthroplasty (TKA) remains unknown. The study purpose was to determine if patient outcomes are affected by intraoperative ligament balance measured with force-sensing implant trials and if an optimal "target" balance exists. A multicenter, retrospective study reviewed consecutive TKAs performed by 3 surgeons. TKA's were performed with standard surgical techniques and ligament releases. After final implants were made, sensor-embedded smart tibial trials were inserted, and compartment forces recorded throughout the range of motion. Clinical outcome measures were obtained preoperatively and at 4 months. Statistical analysis correlated ligament balance with clinical outcomes. One hundred eighty-nine consecutive TKAs were analyzed. Patients were grouped by average medial and lateral compartment force differences. Twenty-nine TKAs (15%) were balanced within 15 lbs and 53 (28%) were "balanced" greater than 75 lbs. Greater improvement in University of California Los Angeles activity level was associated with a mediolateral force difference <60 lbs. (P = .006). Knee Society objective, function, and satisfaction scores, and self-reported health state were unrelated to mediolateral balance in the knee. Intraoperative force-sensing has potential in providing real-time objective data to optimize TKA outcomes. These data support some early outcomes may improve by balancing TKAs within 60 lbs difference. Close follow-up is warranted to determine if gait pattern adaptations affect longer term outcomes with greater or less ligament "imbalance." Copyright © 2016 Elsevier Inc. All rights reserved.

In vivo and 3-dimensional functional anatomy of the anterior bundle of the medial collateral ligament of the elbow.

PubMed

Miyake, Junichi; Moritomo, Hisao; Masatomi, Takashi; Kataoka, Toshiyuki; Murase, Tsuyoshi; Yoshikawa, Hideki; Sugamoto, Kazuomi

2012-08-01

Although the anterior bundle of the medial collateral ligament (AMCL) is a critical stabilizer of the elbow joint, little information exists on in vivo and 3-dimensional functional anatomy of the AMCL. The purposes of this study were to investigate in vivo changes in the length of the AMCL during elbow flexion and to clarify the 3-dimensional functional anatomy of the AMCL. We created 3-dimensional models of the AMCL and bones from computed tomography data of 4 healthy elbows in 5 different elbow positions. The AMCL was subdivided into 9 ligaments. We calculated changes in lengths of ligaments during flexion and related ligament origins to the axis of rotation of the elbow joint. There were 4 uniquely configured isometric ligaments, where their origins aligned broadly along the course of the axis of rotation in the coronal plane. The medially originating ligaments inserted on the posterior portion of the tubercle of the coronoid process, whereas the laterally originating ligaments inserted on its anterior portion. There were 5 non-isometric ligaments, 3 of which had origins proximal to the axis and became taut only in extension and the other 2 having origins distal to the axis and becoming taut only in flexion. Isometric ligaments within the AMCL do not originate from a narrow area; rather, they originate from a broader area that extends more medially in the coronal plane than previously thought, which explains how the AMCL reconciles isometricity and robustness. The proximal and distal ligaments act as checkreins that work only at the limits of elbow motion. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Anterior Cruciate Ligament Biomechanics During Robotic and Mechanical Simulations of Physiologic and Clinical Motion Tasks: A Systematic Review and Meta-Analysis

PubMed Central

Bates, Nathaniel A.; Myer, Gregory D.; Shearn, Jason T.; Hewett, Timothy E.

2014-01-01

Investigators use in vitro joint simulations to invasively study the biomechanical behaviors of the anterior cruciate ligament. The aims of these simulations are to replicate physiologic conditions, but multiple mechanisms can be used to drive in vitro motions, which may influence biomechanical outcomes. The objective of this review was to examine, summarize, and compare biomechanical evidence related to anterior cruciate ligament function from in vitro simulations of knee motion. A systematic review was conducted (2004 to 2013) in Scopus, PubMed/Medline, and SPORTDiscus to identify peer-reviewed studies that reported kinematic and kinetic outcomes from in vitro simulations of physiologic or clinical tasks at the knee. Inclusion criteria for relevant studies were articles published in English that reported on whole-ligament anterior cruciate ligament mechanics during the in vitro simulation of physiologic or clinical motions on cadaveric knees that were unaltered outside of the anterior-cruciate-ligament-intact, -deficient, and -reconstructed conditions. A meta-analysis was performed to synthesize biomechanical differences between the anterior-cruciate-ligament-intact and reconstructed conditions. 77 studies met our inclusion/exclusion criteria and were reviewed. Combined joint rotations have the greatest impact on anterior cruciate ligament loads, but the magnitude by which individual kinematic degrees of freedom contribute to ligament loading during in vitro simulations is technique-dependent. Biomechanical data collected in prospective, longitudinal studies corresponds better with robotic-manipulator simulations than mechanical-impact simulations. Robotic simulation indicated that the ability to restore intact anterior cruciate ligament mechanics with anterior cruciate ligament reconstructions was dependent on loading condition and degree of freedom examined. PMID:25547070

[Clinical auxiliary diagnosis value of high frequency ultrasonographic measurements of the thickness of transverse carpal ligaments in carpal tunnel syndrome patients].

PubMed

Xu, L; Chen, F M; Wang, L; Zhang, P X; Jiang, X R

2016-04-18

To evaluate the meaning and value of high-frequency ultrasound in the diagnosis of carpal tunnel syndrome (CTS). In this study, 48 patients (unilateral hand) with CTS were analyzed. The thickness of transverse carpal ligaments at the pisiform bone was measured using high-frequency ultrasound. Open carpal tunnel release procedure was performed in the 48 CTS patients, and the thickness of transverse carpal ligaments at the hamate hook bone measured using vernier caliper under direct vision. The accuracy of thickness of transverse carpal ligaments was evaluated using high-frequency ultrasound. high-frequency ultrasound measurement of thickness of transverse carpal ligaments at the hamate hook bone and pisiform bone, and determination of the diagnostic threshold measurement index using receiver operating characteristic (ROC) curve, sensitivity and specificity were performed and the correlation between the thickness of transverse carpal ligaments and nerve conduction study (NCS) analyzed. The thickness of transverse carpal ligaments in the CTS patients were (0.42±0.08) cm (high-frequency ultrasound) and (0.41±0.06) cm (operation) at hamate hook bone, and there was no significant difference between the two ways (t=0.672, P>0.05). The optimal cut-off value of the transverse carpal ligaments at hamate hook bone was 0.385 cm, the sensitivity 0.775, and the specificity 0.788. The optimal cut-off value of the transverse carpal ligaments at the pisiform bone was 0.315 cm, the sensitivity 0.950, and the specificity 1.000. The transverse carpal ligaments thickness and wrist-index finger sensory nerve conduction velocity (SCV), wrist-middle finger SCV showed a negative correlation. High frequency ultrasound measurements of thickness of transverse carpal ligaments is a valuable method for the diagnosis of CTS.

Accuracy of low-field magnetic resonance imaging versus radiography for guiding injection of equine distal interphalangeal joint collateral ligaments.

PubMed

Lamb, Megan M; Barrett, Jennifer G; White, Nathaniel A; Werre, Stephen R

2014-01-01

Desmopathy of the distal interphalangeal joint collateral ligament is a common cause of lameness in the horse and carries a variable prognosis for soundness. Intralesional treatment has been proposed for improving outcome; however, limited reports describe methods for injecting this ligament. The purpose of this study was to compare accuracy of low-field magnetic resonance imaging (MRI) vs. radiography for injecting the collateral ligament of the distal interphalangeal joint. Equine cadaver digit pairs (n = 10) were divided by random assignment to injection of the ligament by either technique. An observer unaware of injection technique determined injection success based on postinjection MRI and/or gross sections acquired from the proximal, middle, and distal portions of the ligament. McNemar's test was performed to determine statistical difference between injection techniques, the number of injection attempts, and injection of the medial or lateral collateral ligament. Magnetic resonance imaging guided injection was successful more frequently than radiographic-guided injection based on postinjection MRI (24 of 30 vs. 9 of 30; P = 0.0006) and gross sections (26 of 30 vs. 13 of 30; P = 0.0008). At each level of the ligament (proximal, middle, and distal), MRI-guided injection resulted in more successful injections than radiographic guidance. Statistical significance occurred at the proximal aspect of the collateral ligament based on postinjection MRI (P = 0.0143) and the middle portion of the ligament based on gross sections (P = 0.0253). Findings supported future testing of standing, low-field MRI as a technique for delivering intralesional regenerative therapy in live horses with desmopathy of these collateral ligaments. © 2013 American College of Veterinary Radiology.

Morphological and radiological study of ossified superior transverse scapular ligament as potential risk factor of suprascapular nerve entrapment.

PubMed

Polguj, Michał; Sibiński, Marcin; Grzegorzewski, Andrzej; Waszczykowski, Michał; Majos, Agata; Topol, Mirosław

2014-01-01

The suprascapular notch is covered superiorly by the superior transverse scapular ligament. This region is the most common place of suprascapular nerve entrapment formation. The study was performed on 812 specimens: 86 dry scapulae, 104 formalin-fixed cadaveric shoulders, and 622 computer topography scans of scapulae. In the cases with completely ossified superior transverse scapular ligament, the following measurements were performed: proximal and distal width of the bony bridge, middle transverse and vertical diameter of the suprascapular foramen, and area of the suprascapular foramen. An ossified superior transverse scapular ligament was observed more often in men and in the right scapula. The mean age of the subjects with a completely ossified superior transverse scapular ligament was found to be similar than in those without ossification. The ossified band-shaped type of superior transverse scapular ligament was more common than the fan-shaped type and reduced the space below the ligament to a significantly greater degree. The ossified band-shaped type should be taken into consideration as a potential risk factor in the formation of suprascapular nerve entrapment. It could explain the comparable frequency of neuropathy in various populations throughout the world despite the significant differences between them in occurrence of ossified superior transverse scapular ligament.

Quantitative Comparison of the Microscopic Anatomy of the Human ACL Femoral and Tibial Entheses

PubMed Central

Beaulieu, Mélanie L.; Carey, Grace E.; Schlecht, Stephen H.; Wojtys, Edward M.; Ashton-Miller, James A.

2015-01-01

The femoral enthesis of the human anterior cruciate ligament (ACL) is known to be more susceptible to injury than the tibial enthesis. To determine whether anatomic differences might help explain this difference, we quantified the microscopic appearance of both entheses in 15 unembalmed knee specimens using light microscopy, toluidine blue stain and image analysis. The amount of calcified fibrocartilage and uncalcified fibrocartilage, and the ligament entheseal attachment angle were then compared between the femoral and tibial entheses via linear mixed-effects models. The results showed marked differences in anatomy between the two entheses. The femoral enthesis exhibited a 3.9-fold more acute ligament attachment angle than the tibial enthesis (p < 0.001), a 43% greater calcified fibrocartilage tissue area (p < 0.001), and a 226% greater uncalcified fibrocartilage depth (p < 0.001), with the latter differences being particularly pronounced in the central region. We conclude that the ACL femoral enthesis has more fibrocartilage and a more acute ligament attachment angle than the tibial enthesis, which provides insight into why it is more vulnerable to failure. PMID:26134706

Tri-Layered Nanocomposite Hydrogel Scaffold for the Concurrent Regeneration of Cementum, Periodontal Ligament, and Alveolar Bone.

PubMed

Sowmya, S; Mony, Ullas; Jayachandran, P; Reshma, S; Kumar, R Arun; Arzate, H; Nair, Shantikumar V; Jayakumar, R

2017-04-01

A tri-layered scaffolding approach is adopted for the complete and concurrent regeneration of hard tissues-cementum and alveolar bone-and soft tissue-the periodontal ligament (PDL)-at a periodontal defect site. The porous tri-layered nanocomposite hydrogel scaffold is composed of chitin-poly(lactic-co-glycolic acid) (PLGA)/nanobioactive glass ceramic (nBGC)/cementum protein 1 as the cementum layer, chitin-PLGA/fibroblast growth factor 2 as the PDL layer, and chitin-PLGA/nBGC/platelet-rich plasma derived growth factors as the alveolar bone layer. The tri-layered nanocomposite hydrogel scaffold is cytocompatible and favored cementogenic, fibrogenic, and osteogenic differentiation of human dental follicle stem cells. In vivo, tri-layered nanocomposite hydrogel scaffold with/without growth factors is implanted into rabbit maxillary periodontal defects and compared with the controls at 1 and 3 months postoperatively. The tri-layered nanocomposite hydrogel scaffold with growth factors demonstrates complete defect closure and healing with new cancellous-like tissue formation on microcomputed tomography analysis. Histological and immunohistochemical analyses further confirm the formation of new cementum, fibrous PDL, and alveolar bone with well-defined bony trabeculae in comparison to the other three groups. In conclusion, the tri-layered nanocomposite hydrogel scaffold with growth factors can serve as an alternative regenerative approach to achieve simultaneous and complete periodontal regeneration. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gravity loading induces adenosine triphosphate release and phosphorylation of extracellular signal-regulated kinases in human periodontal ligament cells.

PubMed

Ito, Mai; Arakawa, Toshiya; Okayama, Miki; Shitara, Akiko; Mizoguchi, Itaru; Takuma, Taishin

2014-11-01

The periodontal ligament (PDL) receives mechanical stress (MS) from dental occlusion or orthodontic tooth movement. Mechanical stress is thought to be a trigger for remodeling of the PDL and alveolar bone, although its signaling mechanism is still unclear. So we investigated the effect of MS on adenosine triphosphate (ATP) release and extracellular signal-regulated kinases (ERK) phosphorylation in PDL cells. Mechanical stress was applied to human PDL cells as centrifugation-mediated gravity loading. Apyrase, Ca(2+)-free medium and purinergic receptor agonists and antagonists were utilized to analyze the contribution of purinergic receptors to ERK phosphorylation. Gravity loading and ATP increased ERK phosphorylation by 5 and 2.5 times, respectively. Gravity loading induced ATP release from PDL cells by tenfold. Apyrase and suramin diminished ERK phosphorylation induced by both gravity loading and ATP. Under Ca(2+)-free conditions the phosphorylation by gravity loading was partially decreased, whereas ATP-induced phosphorylation was unaffected. Receptors P2Y4 and P2Y6 were prominently expressed in the PDL cells. Gravity loading induced ATP release and ERK phosphorylation in PDL fibroblasts, and ATP signaling via P2Y receptors was partially involved in this phosphorylation, which in turn would enhance gene expression for the remodeling of PDL tissue during orthodontic tooth movement. © 2013 Wiley Publishing Asia Pty Ltd.

Bilayered construct for simultaneous regeneration of alveolar bone and periodontal ligament.

PubMed

Nivedhitha Sundaram, M; Sowmya, S; Deepthi, S; Bumgardener, Joel D; Jayakumar, R

2016-05-01

Periodontitis is an inflammatory disease that causes destruction of tooth-supporting tissues and if left untreated leads to tooth loss. Current treatments have shown limited potential for simultaneous regeneration of the tooth-supporting tissues. To recreate the complex architecture of the periodontium, we developed a bilayered construct consisting of poly(caprolactone) (PCL) multiscale electrospun membrane (to mimic and regenerate periodontal ligament, PDL) and a chitosan/2wt % CaSO4 scaffold (to mimic and regenerate alveolar bone). Scanning electron microscopy results showed the porous nature of the scaffold and formation of beadless electrospun multiscale fibers. The fiber diameter of microfiber and nanofibers was in the range of 10 ± 3 µm and 377 ± 3 nm, respectively. The bilayered construct showed better protein adsorption compared to the control. Osteoblastic differentiation of human dental follicle stem cells (hDFCs) on chitosan/2wt % CaSO4 scaffold showed maximum alkaline phosphatase at seventh day followed by a decline thereafter when compared to chitosan control scaffold. Fibroblastic differentiation of hDFCs was confirmed by the expression of PLAP-1 and COL-1 proteins which were more prominent on PCL multiscale membrane in comparison to control membranes. Overall these results show that the developed bilayered construct might serve as a good candidate for the simultaneous regeneration of the alveolar bone and PDL. © 2015 Wiley Periodicals, Inc.

Do Tibial Plateau Fractures Worsen Outcomes of Knee Ligament Injuries? A Matched Cohort Analysis

PubMed Central

Cinque, Mark E.; Godin, Jonathan A.; Moatshe, Gilbert; Chahla, Jorge; Kruckeberg, Bradley M.; Pogorzelski, Jonas; LaPrade, Robert F.

2017-01-01

Background: Tibial plateau fractures account for a small portion of all fractures; however, these fractures can pose a surgical challenge when occurring concomitantly with ligament injuries. Purpose/Hypothesis: The purpose of this study was to compare 2-year outcomes of soft tissue reconstruction with or without a concomitant tibial plateau fracture and open reduction internal fixation. We hypothesized that patients with a concomitant tibial plateau fracture at the time of soft tissue surgery would have inferior outcomes compared with patients without an associated tibial plateau fracture. Study Design: Cohort study; Level of evidence, 3. Methods: Forty patients were included in this study: 8 in the fracture group and 32 in the matched control group. Inclusion criteria for the fracture group included patients who were at least 18 years old at the time of surgery and sustained a tibial plateau fracture and a concomitant injury of the anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament, or fibular collateral ligament in isolation or any combination of cruciate or collateral ligaments and who subsequently underwent isolated or combined ligament reconstruction. Patients were excluded if they underwent prior ipsilateral knee surgery, sustained additional bony injuries, or sustained an isolated extra-articular ligament injury at the time of injury. Each patient with a fracture was matched with 4 patients from a control group who had no evidence of a tibial plateau fracture but underwent the same soft tissue reconstruction procedure. Results: Patients in the fracture group improved significantly from preoperatively to postoperatively with respect to Short Form–12 (P < .05) and Western Ontario and McMaster Universities Osteoarthritis Index total scores (P < .05). The Lysholm (P = .075) and Tegner scores (P = .086) also improved, although this was not statistically significant. Patients in the control group improved significantly from preoperatively to postoperatively across all measured scores. A comparison of the postoperative results between the 2 groups showed no statistically significant difference. Conclusion: The presence of a tibial plateau fracture in conjunction with a ligamentous knee injury did not have a negative effect on postoperative patient-reported outcomes. Patient-reported outcome scores after surgery in both the fracture and control groups improved beyond the minimally clinically important difference, indicating that the presence of a fracture did not detract from the outcomes observed in patients without fractures undergoing concomitant ligament reconstruction. PMID:28840154

Reduced functional loads alter the physical characteristics of the bone-periodontal ligament-cementum complex.

PubMed

Niver, E L; Leong, N; Greene, J; Curtis, D; Ryder, M I; Ho, S P

2011-12-01

Adaptive properties of the bone-periodontal ligament-tooth complex have been identified by changing the magnitude of functional loads using small-scale animal models, such as rodents. Reported adaptive responses as a result of lower loads due to softer diet include decreased muscle development, change in structure-function relationship of the cranium, narrowed periodontal ligament space, and changes in the mineral level of the cortical bone and alveolar jaw bone and in the glycosaminoglycans of the alveolar bone. However, the adaptive role of the dynamic bone-periodontal ligament-cementum complex to prolonged reduced loads has not been fully explained to date, especially with regard to concurrent adaptations of bone, periodontal ligament and cementum. Therefore, in the present study, using a rat model, the temporal effect of reduced functional loads on physical characteristics, such as morphology and mechanical properties and the mineral profiles of the bone-periodontal ligament-cementum complex was investigated. Two groups of 6-wk-old male Sprague-Dawley rats were fed nutritionally identical food with a stiffness range of 127-158 N/mm for hard pellet or 0.3-0.5 N/mm for soft powder forms. Spatio-temporal adaptation of the bone-periodontal ligament-cementum complex was identified by mapping changes in the following: (i) periodontal ligament collagen orientation and birefringence using polarized light microscopy, bone and cementum adaptation using histochemistry, and bone and cementum morphology using micro-X-ray computed tomography; (ii) mineral profiles of the periodontal ligament-cementum and periodontal ligament-bone interfaces by X-ray attenuation; and (iii) microhardness of bone and cementum by microindentation of specimens at ages 6, 8, 12 and 15 wk. Reduced functional loads over prolonged time resulted in the following adaptations: (i) altered periodontal ligament orientation and decreased periodontal ligament collagen birefringence, indicating decreased periodontal ligament turnover rate and decreased apical cementum resorption; (ii) a gradual increase in X-ray attenuation, owing to mineral differences, at the periodontal ligament-bone and periodontal ligament-cementum interfaces, without significant differences in the gradients for either group; (iii) significantly (p < 0.05) lower microhardness of alveolar bone (0.93 ± 0.16 GPa) and secondary cementum (0.803 ± 0.13 GPa) compared with the higher load group insert bone = (1.10 ± 0.17 and cementum = 0.940 ± 0.15 GPa, respectively) at 15 wk, indicating a temporal effect of loads on the local mineralization of bone and cementum. Based on the results from this study, the effect of reduced functional loads for a prolonged time could differentially affect morphology, mechanical properties and mineral variations of the local load-bearing sites in the bone-periodontal ligament-cementum complex. These observed local changes in turn could help to explain the overall biomechanical function and adaptations of the tooth-bone joint. From a clinical translation perspective, our study provides an insight into modulation of load on the complex for improved tooth function during periodontal disease and/or orthodontic and prosthodontic treatments. © 2011 John Wiley & Sons A/S.

Proteomic differences between native and tissue‐engineered tendon and ligament

PubMed Central

Tew, Simon R.; Peffers, Mandy; Canty‐Laird, Elizabeth G.; Comerford, Eithne

2016-01-01

Tendons and ligaments (T/Ls) play key roles in the musculoskeletal system, but they are susceptible to traumatic or age‐related rupture, leading to severe morbidity as well as increased susceptibility to degenerative joint diseases such as osteoarthritis. Tissue engineering represents an attractive therapeutic approach to treating T/L injury but it is hampered by our poor understanding of the defining characteristics of the two tissues. The present study aimed to determine differences in the proteomic profile between native T/Ls and tissue engineered (TE) T/L constructs. The canine long digital extensor tendon and anterior cruciate ligament were analyzed along with 3D TE fibrin‐based constructs created from their cells. Native tendon and ligament differed in their content of key structural proteins, with the ligament being more abundant in fibrocartilaginous proteins. 3D T/L TE constructs contained less extracellular matrix (ECM) proteins and had a greater proportion of cellular‐associated proteins than native tissue, corresponding to their low collagen and high DNA content. Constructs were able to recapitulate native T/L tissue characteristics particularly with regard to ECM proteins. However, 3D T/L TE constructs had similar ECM and cellular protein compositions indicating that cell source may not be an important factor for T/L tissue engineering. PMID:27080496

Fibroblast growth factor 8 is expressed at higher levels in lactating human breast and in breast cancer.

PubMed

Zammit, C; Coope, R; Gomm, J J; Shousha, S; Johnston, C L; Coombes, R C

2002-04-08

Fibroblast growth factor 8 can transform NIH3T3 cells and its expression has been found to be associated with breast and prostate cancer. Following our finding that fibroblast growth factor 8 mRNA expression is increased in breast cancer, we have undertaken an immunohistochemistry study of fibroblast growth factor 8 expression in a series of human breast tissues and other normal tissues. Our findings confirm increased expression of fibroblast growth factor 8 in malignant breast tissue but also show significant fibroblast growth factor 8 expression in non-malignant breast epithelial cells. No significant difference in fibroblast growth factor 8 expression was found between different grades of ductal carcinoma, lobular carcinoma and ductal carcinoma in-situ or cancer of different oestrogen receptor, progesterone receptor or nodal status. The highest levels of fibroblast growth factor 8 expression were found in lactating breast tissues and fibroblast growth factor 8 was also detected in human milk. A survey of other normal tissues showed that fibroblast growth factor 8 is expressed in the proliferative cells of the dermis and epithelial cells in colon, ovary fallopian tube and uterus. Fibroblast growth factor 8 appears to be expressed in several organs in man and appears to have an importance in lactation.

Influence of disruption of the acromioclavicular and coracoclavicular ligaments on glenohumeral motion: a kinematic evaluation.

PubMed

Walley, Kempland C; Haghpanah, Babak; Hingsammer, Andreas; Harlow, Ethan R; Vaziri, Ashkan; DeAngelis, Joseph P; Nazarian, Ara; Ramappa, Arun J

2016-11-17

Changes to the integrity of the acromioclavicular (AC) joint impact scapulothoracic and clavicular kinematics. AC ligaments provide anterior-posterior stability, while the coracoclavicular (CC) ligaments provide superior-inferior stability and a restraint to scapular internal rotation. The purpose of this cadaveric study was to describe the effect of sequential AC and CC sectioning on glenohumeral (GH) kinematics during abduction (ABD) of the arm. We hypothesized that complete AC ligament insult would result in altered GH translation in the anterior-posterior plane during abduction, while subsequent sectioning of both CC ligaments would result in an increasing inferior shift in GH translation. Six cadaveric shoulders were studied to evaluate the impact of sequential sectioning of AC and CC ligaments on GH kinematics throughout an abduction motion in the coronal plane. Following an examination of the baseline, uninjured kinematics, the AC ligaments were then sectioned sequentially: (1) Anterior, (2) Inferior, (3) Posterior, and (4) Superior. Continued sectioning of CC ligamentous structures followed: the (5) trapezoid and then the (6) conoid ligaments. For each group, the GH translation and the area under the curve (AUC) were measured during abduction using an intact cadaveric shoulder. Total translation was calculated for each condition between ABD 30° and ABD 150° using the distance formula, and a univariate analysis was used to compare total translation for each axis during the different conditions. GH kinematics were not altered following sequential resection of the AC ligaments. Disruption of the trapezoid resulted in significant anterior and lateral displacement of the center of GH rotation. Sectioning the conoid ligament further increased the inferior shift in GH displacement. A combined injury of the AC and CC ligaments significantly alters GH kinematics during abduction. Type III AC separations, result in a significant change in the shoulder's motion and may warrant surgical reconstruction to restore normal function.

Change in collateral ligament length and tibiofemoral movement following joint line variation in TKA.

PubMed

Lin, Kun-Jhih; Wei, Hung-Wen; Huang, Chang-Hung; Liu, Yu-Liang; Chen, Wen-Chuan; McClean, Colin Joseph; Cheng, Cheng-Kung

2016-08-01

The primary intent of total knee arthroplasty is the restoration of normal knee kinematics, with ligamentous constraint being a key influential factor. Displacement of the joint line may lead to alterations in ligament attachment sites relative to knee flexion axis and variance of ligamentous constraints on tibiofemoral movement. This study aimed to investigate collaterals strains and tibiofemoral kinematics with different joint line levels. A previously validated knee model was employed to analyse the change in length of the collateral ligaments and tibiofemoral motion during knee flexion. The models shifted the joint line by 3 and 5 mm both proximally and distally from the anatomical level. The data were captured from full extension to flexion 135°. The elevated joint line revealed a relative increase in distance between ligament attachments for both collateral ligaments in comparison with the anatomical model. Also, tibiofemoral movement decreased with an elevation in the joint line. Conversely, lowering the joint line led to a significant decrease in distance between ligament attachments, but greater tibiofemoral motion. Elevation of the joint line would strengthen the capacity of collateral ligaments for knee motion constraint, whereas a distally shifted joint line might have the advantage of improving tibiofemoral movement by slackening the collaterals. It implies that surgeons can appropriately change the joint line position in accordance with patient's requirement or collateral tensions. A lowered joint line level may improve knee kinematics, whereas joint line elevation could be useful to maintain knee stability. V.

The Integral System

PubMed Central

2011-01-01

The Integral System is a total care management system based on the Integral Theory which states ‘prolapse and symptoms of urinary stress, urge, abnormal bowel & bladder emptying, and some forms of pelvic pain, mainly arise, for different reasons, from laxity in the vagina or its supporting ligaments, a result of altered connective tissue’. Normal function The organs are suspended by ligaments against which muscles contract to open or close the their outlet tubes, urethra and anus. These ligaments fall naturally into a three-zone zone classification, anterior, middle, and posterior. Dysfunction Damaged ligaments weaken the force of muscle contraction, causing prolapse and abnormal bladder and bowel symptoms Diagnosis A pictorial diagnostic algorithm relates specific symptoms to damaged ligaments in each zone. Treatment In mild cases, new pelvic floor muscle exercises based on a squatting principle strengthen the natural closure muscles and their ligamentous insertions, thereby improving the symptoms predicted by the Theory. With more severe cases, polypropylene tapes applied through “keyhole” incision using special instruments reinforce the damaged ligaments, restoring structure and function. Problems that can be potentially addressed by application of the Integral System Urinary stress incontinenceUrinary urge incontinenceAbnormal bladder emptyingFacal incontinence and “obstructed evacuation” (“constipation”)Pelvic pain, and some types of vulvodynia and interstitial cystitisOrgan prolapse Conclusions Organ prolapse and symptoms are related, and both are mainly caused by laxity in the four main suspensory ligaments and perineal body. Restoration of ligament/fascial length and tension is required to restore anatomy and function. PMID:24578877

Gait perturbation response in chronic anterior cruciate ligament deficiency and repair.

PubMed

Ferber, Reed; Osternig, Louis R; Woollacott, Marjorie H; Wasielewski, Noah J; Lee, Ji Hang

2003-02-01

To determine how chronic anterior cruciate ligament deficient and surgically repaired subjects react to unexpected forward perturbations during gait as compared to healthy controls. Gait testing of 10 chronic anterior cruciate ligament deficient subjects prior to and three months following reconstructive surgery, and 10 uninjured controls. The ability of an anterior cruciate ligament injured individual to react and maintain equilibrium during gait perturbations is critical for the prevention of reinjury. No studies have investigated how these individuals respond to unexpected perturbations during normal gait. An unexpected forward perturbation was induced upon heel strike using a force plate capable of translational movement. Prior to surgery, the anterior cruciate ligament subjects exhibited a greater knee extensor moment in response to the perturbation compared to healthy controls. Following surgery, the anterior cruciate ligament injured subjects exhibited a static knee position and a sustained knee extensor moment throughout stance in response to the perturbation as compared to controls. These data suggest that chronic anterior cruciate ligament deficient subjects rely heavily on knee extensor musculature to prevent collapse in response to an unexpected perturbation. This same reactive response was more pronounced 3 months following surgery. The results suggest that, prior to and following surgery, chronic anterior cruciate ligament injured subjects respond differently than healthy controls to an unexpected perturbation during gait. Anterior cruciate ligament injured or repaired subjects do not reduce or avoid vigorous contraction of the quadriceps muscles when responding to gait perturbations.

An update on the constitutive relation of ligament tissues with the effects of collagen types.

PubMed

Wan, Chao; Hao, Zhixiu; Tong, Lingying; Lin, Jianhao; Li, Zhichang; Wen, Shizhu

2015-10-01

The musculoskeletal ligament is a kind of multiscale composite material with collagen fibers embedded in a ground matrix. As the major constituent in ligaments to bear external loads, collagens are composed mainly of two collagen contents with different mechanical properties, i.e., types I and III collagen. The constitutive relation of ligaments plays a critical role in the stability and normal function of human joints. However, collagen types have not been distinguished in the previous constitutive relations. In this paper a constitutive relation for ligament tissues was modified based on the previous constitutive relation by considering the effects of collagen types. Both the collagen contents and the mechanical properties of sixteen ligament specimens from four cadaveric human knee joints were measured for determining their material coefficients in the constitutive relation. The mechanical behaviors of ligaments were obtained from both the uniaxial tensile and simple shear tests. A linear regression between joint kinematic results from in vitro and in silico experiments was made to validate the accuracy of this constitutive relation. The high correlation coefficient (R(2)=0.93) and significance (P<0.0001) of the regression equation revealed that this modified constitutive relation of ligaments was accurate to be used in studying joint biomechanics. Another finite element analysis with collagen contents changing demonstrated that the effect of variations in collagen ratios on both joint kinematics and ligament biomechanics could be simulated by this constitutive relation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Addition of lateral bending range of motion measurement to standard sagittal measurement to improve diagnosis sensitivity of ligamentous injury in the human lower cervical spine.

PubMed

Leahy, P Devin; Puttlitz, Christian M

2016-01-01

This study examined the cervical spine range of motion (ROM) resulting from whiplash-type hyperextension and hyperflexion type ligamentous injuries, and sought to improve the accuracy of specific diagnosis of these injuries. The study was accomplished by measurement of ROM throughout axial rotation, lateral bending, and flexion and extension, using a validated finite element model of the cervical spine that was modified to simulate hyperextension and/or hyperflexion injuries. It was found that the kinematic difference between hyperextension and hyperflexion injuries was minimal throughout the combined flexion and extension ROM measurement that is commonly used for clinical diagnosis of cervical ligamentous injury. However, the two injuries demonstrated substantially different ROM under axial rotation and lateral bending. It is recommended that other bending axes beyond flexion and extension are incorporated into clinical diagnosis of cervical ligamentous injury.

Varus alignment leads to increased forces in the anterior cruciate ligament.

PubMed

van de Pol, Gerrit Jan; Arnold, Markus P; Verdonschot, Nico; van Kampen, Albert

2009-03-01

Varus thrust of the knee is a dynamic increase of an often preexisting varus angle and it is suspected to be a major reason for failure of anterior cruciate ligament reconstructions. However, it is not known if a direct relationship exists between varus thrust and forces in the anterior cruciate ligament. Forces in the anterior cruciate ligament increase with increasing varus alignment, and consequently an anterior cruciate ligament deficiency in a varus-aligned leg leads to more lateral tibiofemoral joint opening. Controlled laboratory study. Six human cadaver legs were axially loaded with 3 different weightbearing lines--a neutral weightbearing line, a weightbearing line that passes through the middle of the medial tibial plateau (50% varus), and a line passing the edge of the medial tibial plateau (100% varus)--that were used to create a varus moment. The resulting lateral tibiofemoral joint opening and corresponding anterior cruciate ligament tension were measured. The tests were repeated with and without the anterior cruciate ligament in place. In the neutral aligned legs, there was no apparent lateral joint opening, and no anterior cruciate ligament tension change was noted. The lateral joint opening increased when the weightbearing line increased from 0% to 50% to 100%. The lateral joint opening was significantly higher in 10 degrees of knee flexion compared with knee extension. In the 100% varus weightbearing line, the anterior cruciate ligament tension was significantly higher (53.9 N) compared with neutral (31 N) or the 50% weightbearing line (37.9 N). A thrust could only be observed in the 100% weightbearing line tests. In the absence of an anterior cruciate ligament, there was more lateral joint opening, although this was only significant in the 100% weightbearing line. There is a direct relationship between varus alignment and anterior cruciate ligament tension. In the absence of an anterior cruciate ligament, the amount of lateral opening tends to increase. With increasing lateral opening, a thrust can sometimes be experimentally observed. A varus alignment in an anterior cruciate ligament-deficient knee does not necessarily lead to a varus thrust and therefore does not always need operative varus alignment correction. However, in an unstable anterior cruciate ligament-deficient knee with a varus thrust, it might be safer to perform a high valgus tibial osteotomy to minimize the risk of an anterior cruciate ligament reconstruction failure.

A Review on Biomechanics of Anterior Cruciate Ligament and Materials for Reconstruction

PubMed Central

Marieswaran, M.; Jain, Ishita; Garg, Bhavuk; Sharma, Vijay

2018-01-01

The anterior cruciate ligament is one of the six ligaments in the human knee joint that provides stability during articulations. It is relatively prone to acute and chronic injuries as compared to other ligaments. Repair and self-healing of an injured anterior cruciate ligament are time-consuming processes. For personnel resuming an active sports life, surgical repair or replacement is essential. Untreated anterior cruciate ligament tear results frequently in osteoarthritis. Therefore, understanding of the biomechanics of injury and properties of the native ligament is crucial. An abridged summary of the prominent literature with a focus on key topics on kinematics and kinetics of the knee joint and various loads acting on the anterior cruciate ligament as a function of flexion angle is presented here with an emphasis on the gaps. Briefly, we also review mechanical characterization composition and anatomy of the anterior cruciate ligament as well as graft materials used for replacement/reconstruction surgeries. The key conclusions of this review are as follows: (a) the highest shear forces on the anterior cruciate ligament occur during hyperextension/low flexion angles of the knee joint; (b) the characterization of the anterior cruciate ligament at variable strain rates is critical to model a viscoelastic behavior; however, studies on human anterior cruciate ligament on variable strain rates are yet to be reported; (c) a significant disparity on maximum stress/strain pattern of the anterior cruciate ligament was observed in the earlier works; (d) nearly all synthetic grafts have been recalled from the market; and (e) bridge-enhanced repair developed by Murray is a promising technique for anterior cruciate ligament reconstruction, currently in clinical trials. It is important to note that full extension of the knee is not feasible in the case of most animals and hence the loading pattern of human ACL is different from animal models. Many of the published reviews on the ACL focus largely on animal ACL than human ACL. Further, this review article summarizes the issues with autografts and synthetic grafts used so far. Autografts (patellar tendon and hamstring tendon) remains the gold standard as nearly all synthetic grafts introduced for clinical use have been withdrawn from the market. The mechanical strength during the ligamentization of autografts is also highlighted in this work. PMID:29861784

Biomechanical cadaveric comparison of patellar ligament suture protected by a steel cable versus a synthetic cable.

PubMed

Bouget, P; Breque, C; Beranger, J S; Faure, J P; Khiami, F; Vendeuvre, T

2017-12-01

Purpose and hypothesis: Patellar ligament rupture is a rare disabling pathology requiring a surgical ligament suture protected by a frame. The gold standard is the steel cable, but its rigidity and the necessity of a surgical re-intervention for its removal render it unsatisfactory. The objective of this paper is to quantify the mechanical protection provided by the terylene® in comparison with steel. Twenty-four knees of 12 fresh frozen cadaveric subjects were divided into 2 homogeneous groups (terylene and steel) of 12 knees (mean age = 69.3 years). Proximal ligament repair was performed according to a three-tunnel transosseous reinsertion technique. Mechanical tests were performed in flexion to simulate movement of the knee. The interligament gap and the amplitude angulation of the knee were measured by a system of extensometer and optical goniometer. Mechanical analysis permitted calculation of flexion amplitude for a ligament gap of 1 and 2 mm taking as initial angle the adjusting angle of pretension of the protection frame. Study of deformations of frames was performed. Statistical analysis was performed with a Wilcoxon Mann Whitney test. There is no significant difference in protection of the ligament suture between the "terylene" and "steel" groups. Mean flexion amplitudes (mΔF) show no significant differences between the 2 groups for a distension of the suture of 1 mm (m ΔF terylene1 = 4.74 °; mΔF steel1 = 5.91°; p = 0.198) and 2 mm (mΔF terylene2 = 8.71°; mΔF steel2 = 10.41°; p = 0.114). Elastic deformation of terylene was significantly greater than that of steel (p = 0.0004). Suture protection of the patellar ligament by a terylene wire is not significantly different from that provided by steel frame. The elastic properties of terylene and absence of a need for re intervention to secure its removal lead us towards its use in acute ruptures of the patellar ligament. The main limits involve the properties of the chain extenders with no contraction/muscle shortening and partial dehydration of tendons and ligaments and the mean age of 69.3 years. Level 5.

Collateral ligament strains during knee joint laxity evaluation before and after TKA.

PubMed

Delport, Hendrik; Labey, Luc; De Corte, Ronny; Innocenti, Bernardo; Vander Sloten, Jos; Bellemans, Johan

2013-08-01

Passive knee stability is provided by the soft tissue envelope. There is consensus among orthopedic surgeons that good outcome in Total Knee Arthroplasty requires equal tension in the medial/lateral compartment of the knee joint, as well as equal tension in the flexion/extension gap. The purpose of this study was to quantify the ligament laxity in the normal non-arthritic knee before and after Posterior-Stabilized Total Knee Arthroplasty. We hypothesized that the Medial/Lateral Collateral Ligament shows minimal changes in length when measured directly by extensometers in the native human knee during varus/valgus laxity testing. We also hypothesized that due to differences in material properties and surface geometry, native laxity is difficult to reconstruct using a Posterior-Stabilized Total Knee. Six specimens were used to perform this in vitro cadaver test using extensometers to provide numerical values for laxity and varus-valgus tilting in the frontal plane. This study enabled a precise measurement of varus-valgus laxity as compared with the clinical assessment. The strains in both ligaments in the replaced knee were different from those in the native knee. Both ligaments were stretched in extension, in flexion the Medial Collateral Ligament tends to relax and the Lateral Collateral Ligament remains tight. As material properties and surface geometry of the replaced knee add stiffness to the joint, we recommend to avoid overstuffing the joint, when using this type of Posterior-Stabilized Total Knee Arthroplasty, in order to obtain varus/valgus laxity close to the native joint. Copyright © 2013 Elsevier Ltd. All rights reserved.

Development of a subject-specific model to predict the forces in the knee ligaments at high flexion angles.

PubMed

Yang, Zhaochun; Wickwire, Alexis C; Debski, Richard E

2010-11-01

Recent clinical evidence has suggested that tasks performed in kneeling or squatting postures place the knee at a higher risk for injury because loads across the knee might overload the ligaments. The objective of this study was to develop a subject-specific model of the knee that is kinematically driven to predict the forces in the major ligaments at high flexion angles. The geometry of the femur, tibia, and fibula and the load-elongation curves representing the structural properties of the ACL, PCL, LCL, and MCL served as inputs to the model, which represented each ligament as a nonlinear elastic spring. To drive the model, kinematic data was obtained while loads were applied to the same cadaveric knee at four flexion angles. The force in each ligament during the recorded kinematic data allowed an optimization procedure to determine the location of the ligament attachment sites on each bone and their reference lengths. The optimization procedure could successfully minimize the differences between the experimental and predicted forces only when the kinematics at 90°, 120°, and 140° of flexion were utilized. This finding suggests that the ligaments at the knee function differently at high-flexion angles compared to low flexion angles and separate models must be used to examine each range of motion. In the future, the novel experimental and computational methodology will be used to construct additional models and additional knee kinematics will be input to help elucidate mechanisms of injury during tasks performed in kneeling or squatting postures.

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

Carmona-Rodriguez, Bruno; Alvarez-Perez, Marco Antonio; Narayanan, A. Sampath

We recently presented evidence showing that a human cementoblastoma-derived protein, named Cementum Protein 1 (CEMP1) may play a role as a local regulator of cementoblast differentiation and cementum-matrix mineralization. This protein was shown to be expressed by cementoblasts and progenitor cells localized in the periodontal ligament. In this study we demonstrate that transfection of CEMP1 into human gingival fibroblasts (HGF) induces mineralization and expression of bone and cementum-matrix proteins. The transfected HGF cells had higher alkaline phosphatase activity and proliferation rate and they expressed genes for alkaline phosphatase, bone sialoprotein, osteocalcin, osteopontin, the transcription factor Runx2/Cbfa1, and cementum attachment proteinmore » (CAP). They also produced biological-type hydroxyapatite. These findings indicate that the CEMP1 might participate in differentiation and mineralization of nonosteogenic cells, and that it might have a potential function in cementum and bone formation.« less

Functional tissue engineering of ligament healing

PubMed Central

2010-01-01

Ligaments and tendons are dense connective tissues that are important in transmitting forces and facilitate joint articulation in the musculoskeletal system. Their injury frequency is high especially for those that are functional important, like the anterior cruciate ligament (ACL) and medial collateral ligament (MCL) of the knee as well as the glenohumeral ligaments and the rotator cuff tendons of the shoulder. Because the healing responses are different in these ligaments and tendons after injury, the consequences and treatments are tissue- and site-specific. In this review, we will elaborate on the injuries of the knee ligaments as well as using functional tissue engineering (FTE) approaches to improve their healing. Specifically, the ACL of knee has limited capability to heal, and results of non-surgical management of its midsubstance rupture have been poor. Consequently, surgical reconstruction of the ACL is regularly performed to gain knee stability. However, the long-term results are not satisfactory besides the numerous complications accompanied with the surgeries. With the rapid development of FTE, there is a renewed interest in revisiting ACL healing. Approaches such as using growth factors, stem cells and scaffolds have been widely investigated. In this article, the biology of normal and healing ligaments is first reviewed, followed by a discussion on the issues related to the treatment of ACL injuries. Afterwards, current promising FTE methods are presented for the treatment of ligament injuries, including the use of growth factors, gene delivery, and cell therapy with a particular emphasis on the use of ECM bioscaffolds. The challenging areas are listed in the future direction that suggests where collection of energy could be placed in order to restore the injured ligaments and tendons structurally and functionally. PMID:20492676

Growth characteristics of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies.

PubMed

Miller, C B; Wilson, D A; Keegan, K G; Kreeger, J M; Adelstein, E H; Ganjam, V K

2000-01-01

To determine if there is a difference in in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. To determine the effects of a corticosteroid and monokine on in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. Growth of fibroblasts from tissues harvested from the trunk and limb were compared from horse and pony samples grown in control media and control media with triamcinolone or monokine added. Dermal and subcutaneous tissue from 22 horses and 17 ponies of various ages and breeds. Fibroblast growth was assessed by tritiated thymidine uptake using standard cell culture techniques. The effect of a monokine or triamcinolone plus control media were compared with control media for fibroblast growth. Fibroblast growth from tissues isolated from the horse limb was significantly less than growth from the horse trunk and the limb and trunk of ponies. Monokine was more effective than triamcinolone in suppressing fibroblast growth from tissues isolated from the trunk and limb in both horses and ponies. There are growth differences in fibroblasts isolated from the limb of horses compared with those isolated from the trunk and from the limb and trunk of ponies. The difference in fibroblast growth from tissues isolated from the trunk and limb of horses and ponies may provide evidence for the difference reported in the healing characteristics of limb wounds in horses and ponies. Influencing fibroblast growth may provide a key to controlling the development of exuberant granulation tissue in horses and ponies.

Stem Cells Derived from Tooth Periodontal Ligament Enhance Functional Angiogenesis by Endothelial Cells

PubMed Central

Yeasmin, Shamima; Ceccarelli, Jacob; Vigen, Marina; Carrion, Bita; Putnam, Andrew J.; Tarle, Susan A.

2014-01-01

In regenerative medicine approaches involving cell therapy, selection of the appropriate cell type is important in that the cells must directly (differentiation) or indirectly (trophic effects) participate in the regenerative response. Regardless of the mode of action of the cells, angiogenesis underlies the success of these approaches. Stem cells derived from tooth tissues, specifically the periodontal ligament of teeth (periodontal ligament stem cells [PDLSCs]), have recently been identified as a good source of multipotent cells for cell therapies. PDLSCs have demonstrated properties similar to mesenchymal stem cells (MSCs), yet, unlike MSCs, their vascular potential has not been previously demonstrated. Thus, the aim of this study was to determine if PDLSCs could modulate angiogenesis. In comparison to MSCs and stem cells derived from tooth pulp tissues (SHEDs), we first determined if PDLSCs released soluble proangiogenic factors with the capacity to induce vessel formation by endothelial cells (ECs). Next, the ability of PDLSCs to modulate angiogenesis was examined through their cotransplantation with ECs in subcutaneous sites of immunocompromised mice. Finally, the stability of the PDLSC-mediated vasculature was determined through evaluation of the maturity and functionality of the vessels formed following PDLSC transplantation. It was determined that PDLSCs produced appreciable levels of vascular endothelial growth factor and basic fibroblast growth factor-2, and additionally, were able to initiate in vitro angiogenesis of ECs comparable to MSC- and SHED-mediated angiogenesis. In vivo cotransplantation of ECs with PDLSCs significantly (>50% increase) enhanced the number of blood vessels formed relative to transplantation of ECs alone. Finally, vessels formed following PDLSC cotransplantation were more mature and less permeable than those formed after transplantation of EC alone. These data demonstrate for the first time that PDLSCs have vascular potential, which could make them a very attractive cell population for utilization in regenerative cell therapies. PMID:24147894

The transverse ligament as a landmark for tibial sagittal insertions of the anterior cruciate ligament: a cadaveric study.

PubMed

Kongcharoensombat, Wirat; Ochi, Mitsuo; Abouheif, Mohamed; Adachi, Nobuo; Ohkawa, Shingo; Kamei, Goki; Okuhara, Atushi; Shibuya, Hoyatoshi; Niimoto, Takuya; Nakasa, Tomoyuki; Nakamae, Atsuo; Deie, Masataka

2011-10-01

The purpose of this study was to determine the relation between the position of the transverse ligament, the anterior edge of the anterior cruciate ligament (ACL) tibial footprint, and the center of the ACL tibial insertion. We used arthroscopy for localization of the anatomic landmarks, followed by insertions of guide pins under direct visualization, and then the position of these guide pins was checked on plain lateral radiographs. The transverse ligament and the anterior aspect of the ACL tibial footprint were identified by arthroscopy in 20 unpaired cadaveric knees (10 left and 10 right). Guide pins were inserted with tibial ACL adapter drill guides under direct observation at the transverse ligament, the anterior aspect of the tibial footprint, and the center of tibial insertion of the ACL. Then, plain lateral radiographs of specimens were taken. The Amis and Jakob line was used to define the attachment of the ACL tibial insertion and the transverse ligament. A sagittal percentage of the location of the insertion point was determined and calculated from the anterior margin of the tibia in the anteroposterior direction. The transverse ligament averaged 21.20% ± 4.1%, the anterior edge of the ACL tibial insertion averaged 21.60% ± 4.0%, and the center of the ACL tibial insertion averaged 40.30% ± 4.8%. There were similar percent variations between the transverse ligament and the anterior edge of the ACL tibial insertion, with no significant difference between them (P = .38). Intraobserver and interobserver reliability was high, with small standard errors of measurement. This study shows that the transverse ligament coincides with the anterior edge of the ACL tibial footprint in the sagittal plane. The transverse ligament can be considered as a new landmark for tibial tunnel positioning during anatomic ACL reconstruction. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Addition of Autologous Mesenchymal Stem Cells to Whole Blood for Bio-Enhanced ACL Repair has No Benefit in the Porcine Model

PubMed Central

Proffen, Benedikt L.; Vavken, Patrick; Haslauer, Carla M.; Fleming, Braden C.; Harris, Chad E.; Machan, Jason T.; Murray, Martha M.

2015-01-01

Background Co-culture of mesenchymal stem cells (MSCs) from the retropatellar fat pad and peripheral blood has been shown to stimulate anterior cruciate ligament (ACL) fibroblast proliferation and collagen production in vitro. Current techniques of bio-enhanced ACL repair in animal studies involve adding a biologic scaffold, in this case an extracellular matrix based scaffold saturated with autologous whole blood, to a simple suture repair of the ligament. Whether the enrichment of whole blood with MSCs would further improve the in vivo results of bio-enhanced ACL repair was investigated. Hypothesis/Purpose The hypothesis was that the addition of MSCs derived from adipose tissue or peripheral blood to the blood-extracellular matrix composite, which is used in bio-enhanced ACL repair to stimulate healing, would improve the biomechanical properties of a bio-enhanced ACL repair after 15 weeks of healing. Study Design Controlled laboratory study. Methods Twenty-four adolescent Yucatan mini-pigs underwent ACL transection followed by: 1) bio-enhanced ACL repair, 2) bio-enhanced ACL repair with the addition of autologous adipose-derived MSCs and 3) bio-enhanced ACL repair with the addition of autologous peripheral blood derived MSCs. After fifteen weeks of healing, structural properties of the ACL (yield & failure load, linear stiffness) were measured. Cell and vascular density were measured in the repaired ACL via histology, and its tissue structure was qualitatively evaluated using the Advanced Ligament Maturity Index. Results After fifteen weeks of healing, there were no significant improvements in the biomechanical or histological properties with the addition of adipose-derived MSCs. The only significant change with the addition of peripheral blood MSCs was an increase in knee anteroposterior (AP) laxity when measured at 30 degrees of flexion. Conclusions These findings suggest that the addition of adipose or peripheral blood MSCs to whole blood prior to saturation of an extracellular matrix carrier with the blood did not improve the functional results of bio-enhanced ACL repair after 15 weeks of healing in the pig model. Clinical Relevance Whole blood represents a practical biologic additive to ligament repair, and any other additive (including stem cells) should be demonstrated to be superior to this baseline before clinical use is considered. PMID:25549633

Quantitative comparison of the microscopic anatomy of the human ACL femoral and tibial entheses.

PubMed

Beaulieu, Mélanie L; Carey, Grace E; Schlecht, Stephen H; Wojtys, Edward M; Ashton-Miller, James A

2015-12-01

The femoral enthesis of the human anterior cruciate ligament (ACL) is known to be more susceptible to injury than the tibial enthesis. To determine whether anatomic differences might help explain this difference, we quantified the microscopic appearance of both entheses in 15 unembalmed knee specimens using light microscopy, toluidine blue stain and image analysis. The amount of calcified fibrocartilage and uncalcified fibrocartilage, and the ligament entheseal attachment angle were then compared between the femoral and tibial entheses via linear mixed-effects models. The results showed marked differences in anatomy between the two entheses. The femoral enthesis exhibited a 3.9-fold more acute ligament attachment angle than the tibial enthesis (p<0.001), a 43% greater calcified fibrocartilage tissue area (p<0.001), and a 226% greater uncalcified fibrocartilage depth (p<0.001), with the latter differences being particularly pronounced in the central region. We conclude that the ACL femoral enthesis has more fibrocartilage and a more acute ligament attachment angle than the tibial enthesis, which provides insight into why it is more vulnerable to failure. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Lateral ligament repair and reconstruction restore neither contact mechanics of the ankle joint nor motion patterns of the hindfoot.

PubMed

Prisk, Victor R; Imhauser, Carl W; O'Loughlin, Padhraig F; Kennedy, John G

2010-10-20

Ankle sprains may damage both the lateral ligaments of the hindfoot and the osteochondral tissue of the ankle joint. When nonoperative treatment fails, operative approaches are indicated to restore both native motion patterns at the hindfoot and ankle joint contact mechanics. The goal of the present study was to determine the effect of lateral ligament injury, repair, and reconstruction on ankle joint contact mechanics and hindfoot motion patterns. Eight cadaveric specimens were tested with use of robotic technology to apply combined compressive (200-N) and inversion (4.5-Nm) loads to the hindfoot at 0° and 20° of plantar flexion. Contact mechanics at the ankle joint were simultaneously measured. A repeated-measures experiment was designed with use of the intact condition as control, with the other conditions including sectioned anterior talofibular and calcaneofibular ligaments, the Broström and Broström-Gould repairs, and graft reconstruction. Ligament sectioning decreased contact area and caused a medial and anterior shift in the center of pressure with inversion loads relative to those with the intact condition. There were no significant differences in inversion or coupled axial rotation with inversion between the Broström repair and the intact condition; however, medial translation of the center of pressure remained elevated after the Broström repair relative to the intact condition. The Gould modification of the Broström procedure provided additional support to the hindfoot relative to the Broström repair, reducing inversion and axial rotation with inversion beyond that of intact ligaments. There were no significant differences in center-of-pressure excursion patterns between the Broström-Gould repair and the intact ligament condition, but this repair increased contact area beyond that with the ligaments intact. Graft reconstruction more closely restored inversion motion than did the Broström-Gould repair at 20° of plantar flexion but limited coupled axial rotation. Graft reconstruction also increased contact areas beyond the lateral ligament-deficient conditions but altered center-of-pressure excursion patterns relative to the intact condition. No lateral ankle ligament reconstruction completely restored native contact mechanics of the ankle joint and hindfoot motion patterns.

A quantitative comparison of morphological and histological characteristics of collagen in the rabbit medial collateral ligament.

PubMed

Wan, Chao; Hao, Zhixiu; Wen, Shizhu

2013-12-01

Collagen fiber is one of the critical factors in determining mechanical properties of ligaments and both the morphological and histological characteristics of collagen have been widely studied. However, there was still no consensus about whether the morphological characteristics of collagen correlated with its histological characteristics in physiological ligaments. Rabbit medial collateral ligaments (MCLs) were measured under a transmission electron microscope and a polarized light microscope plus picrosirius red-staining to obtain the distributions of collagen fibril diameters and types at different anatomical sites of rabbit MCLs, respectively. The correlation between the fibril diameter and type was determined by a correlation analysis. The collagen fibril diameters at the different anatomical sites had different distributions (unimodal or bimodal) and mean fibril diameters were found to increase significantly from the anterior part to the posterior part (P=0.0482) as well as from the proximal to the distal sections (P=0.0208). Type I collagen in the core portion of MCLs was significantly less than at the other four peripheral areas (P<0.005) but no significant variation was found in each respective portion (P>0.05). The low coefficient in the correlation analysis (r=0.3759) demonstrated collagen fibril diameters had no correlation with collagen types. This may provide a new view of collagen types in studying the mechanical behavior of ligaments. Copyright © 2013 Elsevier GmbH. All rights reserved.

Proteomic differences between native and tissue-engineered tendon and ligament.

PubMed

Kharaz, Yalda A; Tew, Simon R; Peffers, Mandy; Canty-Laird, Elizabeth G; Comerford, Eithne

2016-05-01

Tendons and ligaments (T/Ls) play key roles in the musculoskeletal system, but they are susceptible to traumatic or age-related rupture, leading to severe morbidity as well as increased susceptibility to degenerative joint diseases such as osteoarthritis. Tissue engineering represents an attractive therapeutic approach to treating T/L injury but it is hampered by our poor understanding of the defining characteristics of the two tissues. The present study aimed to determine differences in the proteomic profile between native T/Ls and tissue engineered (TE) T/L constructs. The canine long digital extensor tendon and anterior cruciate ligament were analyzed along with 3D TE fibrin-based constructs created from their cells. Native tendon and ligament differed in their content of key structural proteins, with the ligament being more abundant in fibrocartilaginous proteins. 3D T/L TE constructs contained less extracellular matrix (ECM) proteins and had a greater proportion of cellular-associated proteins than native tissue, corresponding to their low collagen and high DNA content. Constructs were able to recapitulate native T/L tissue characteristics particularly with regard to ECM proteins. However, 3D T/L TE constructs had similar ECM and cellular protein compositions indicating that cell source may not be an important factor for T/L tissue engineering. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lateral Ligament Repair and Reconstruction Restore Neither Contact Mechanics of the Ankle Joint nor Motion Patterns of the Hindfoot

PubMed Central

Prisk, Victor R.; Imhauser, Carl W.; O'Loughlin, Padhraig F.; Kennedy, John G.

2010-01-01

Background: Ankle sprains may damage both the lateral ligaments of the hindfoot and the osteochondral tissue of the ankle joint. When nonoperative treatment fails, operative approaches are indicated to restore both native motion patterns at the hindfoot and ankle joint contact mechanics. The goal of the present study was to determine the effect of lateral ligament injury, repair, and reconstruction on ankle joint contact mechanics and hindfoot motion patterns. Methods: Eight cadaveric specimens were tested with use of robotic technology to apply combined compressive (200-N) and inversion (4.5-Nm) loads to the hindfoot at 0° and 20° of plantar flexion. Contact mechanics at the ankle joint were simultaneously measured. A repeated-measures experiment was designed with use of the intact condition as control, with the other conditions including sectioned anterior talofibular and calcaneofibular ligaments, the Broström and Broström-Gould repairs, and graft reconstruction. Results: Ligament sectioning decreased contact area and caused a medial and anterior shift in the center of pressure with inversion loads relative to those with the intact condition. There were no significant differences in inversion or coupled axial rotation with inversion between the Broström repair and the intact condition; however, medial translation of the center of pressure remained elevated after the Broström repair relative to the intact condition. The Gould modification of the Broström procedure provided additional support to the hindfoot relative to the Broström repair, reducing inversion and axial rotation with inversion beyond that of intact ligaments. There were no significant differences in center-of-pressure excursion patterns between the Broström-Gould repair and the intact ligament condition, but this repair increased contact area beyond that with the ligaments intact. Graft reconstruction more closely restored inversion motion than did the Broström-Gould repair at 20° of plantar flexion but limited coupled axial rotation. Graft reconstruction also increased contact areas beyond the lateral ligament-deficient conditions but altered center-of-pressure excursion patterns relative to the intact condition. Conclusions: No lateral ankle ligament reconstruction completely restored native contact mechanics of the ankle joint and hindfoot motion patterns. Clinical Relevance: Our results provide a rationale for conducting long-term, prospective, comparative, in vivo studies to assess the impact of altered mechanics following lateral ligament injury, and its nonoperative and operative treatment, on the development of ankle osteoarthritis. PMID:20962188

Evaluation of the thickness of the medial ulnar collateral ligament in junior high and high school baseball players.

PubMed

Nagamoto, Hideaki; Yamamoto, Nobuyuki; Kurokawa, Daisuke; Takahashi, Hiroyuki; Muraki, Takayuki; Tanaka, Minoru; Koike, Yoichi; Sano, Hirotaka; Itoi, Eiji

2015-07-01

Thickening of the medial ulnar collateral ligament in the throwing arm of adult baseball players is a well-known phenomenon. However, onset of the thickening is unclear among young baseball players. The purpose of this study was to evaluate the thickness of the medial ulnar collateral ligament in junior high and high school baseball players. Seventy-one uninjured and asymptomatic junior high and high school baseball players were included in the study. Participants underwent physical examination after completing a questionnaire, followed by ultrasonographic evaluation. The thickness of the medial ulnar collateral ligament was measured bilaterally. The thickness of the throwing and non-throwing sides in high school and junior high school baseball players, and within each group, was compared and statistically analyzed. The medial ulnar collateral ligament in the throwing arm of high school baseball players was thicker than that in the non-throwing arm (5.5 vs. 4.4 mm), although no significant difference was seen in junior high school baseball players. High school baseball players showed a significantly thicker medial ulnar collateral ligament in the throwing arm than junior high school baseball players. Thickening of the medial ulnar collateral ligament in the throwing arm of asymptomatic and uninjured baseball players may begin by the time the players reach high school.

Biomechanical study using fuzzy systems to quantify collagen fiber recruitment and predict creep of the rabbit medial collateral ligament.

PubMed

Ali, A F; Taha, M M Reda; Thornton, G M; Shrive, N G; Frank, C B

2005-06-01

In normal daily activities, ligaments are subjected to repeated loads, and respond to this environment with creep and fatigue. While progressive recruitment of the collagen fibers is responsible for the toe region of the ligament stress-strain curve, recruitment also represents an elegant feature to help ligaments resist creep. The use of artificial intelligence techniques in computational modeling allows a large number of parameters and their interactions to be incorporated beyond the capacity of classical mathematical models. The objective of the work described here is to demonstrate a tool for modeling creep of the rabbit medial collateral ligament that can incorporate the different parameters while quantifying the effect of collagen fiber recruitment during creep. An intelligent algorithm was developed to predict ligament creep. The modeling is performed in two steps: first, the ill-defined fiber recruitment is quantified using the fuzzy logic. Second, this fiber recruitment is incorporated along with creep stress and creep time to model creep using an adaptive neurofuzzy inference system. The model was trained and tested using an experimental database including creep tests and crimp image analysis. The model confirms that quantification of fiber recruitment is important for accurate prediction of ligament creep behavior at physiological loads.

Tuning ligament shape in dealloyed nanoporous tin and the impact of nanoscale morphology on its applications in Na-ion alloy battery anodes

NASA Astrophysics Data System (ADS)

Detsi, Eric; Petrissans, Xavier; Yan, Yan; Cook, John B.; Deng, Ziling; Liang, Yu-Lun; Dunn, Bruce; Tolbert, Sarah H.

2018-05-01

Control over the morphology of nanostructured materials is of primary importance in structure-property relationship studies. Although the size of ligaments and pores in dealloyed nanoporous metals can be controlled by thermal and/or (electro)chemical treatments, tuning the shape of those ligaments is much harder. In the present work, we use corroding media with different reactivity to effectively tailor the ligament shape in nanoporous tin (NP-Sn) during dealloying by free corrosion. NP-Sn architectures with nanowire and granular ligament shapes were made by controlling the pH of the corroding solution, and thus the rate of Sn oxidation relative to the etching rate of the sacrificial component. The standard nanowire structure was formed under acidic conditions where oxidation was slow, but a hierarchical granular structure was formed when fusion of the Sn nanocrystals was inhibited by surface oxidation. To demonstrate the advantages of this architectural control, these two materials systems were investigated as electrodes for Na-ion battery anodes. Similar initial Na storage capacities of ˜500 and 550 mAh/g were achieved in the nanowire and granular materials, respectively, but the cycle life of the two materials was quite different. NP-Sn with a granular ligament shape showed enhanced stability with a capacity retention of ˜55 % over 95 cycles at a specific current of 40 mA/g. By contrast, NP-Sn with a nanowire ligament shape showed very fast capacity fading within the first 10 cycles. This work thus demonstrates the dramatic impact of the nanoscale morphology on the electrochemical performance of nanoporous materials and highlights the need for both shape and size control in dealloyed nanoporous metals.

Influence of the position of the foot on MRI signal in the deep digital flexor tendon and collateral ligaments of the distal interphalangeal joint in the standing horse.

PubMed

Spriet, M; Zwingenberger, A

2009-05-01

Hyperintense signal is sometimes observed in ligaments and tendons of the equine foot on standing magnetic resonance examination without associated changes in size and shape. In such cases, the presence of a true lesion or an artifact should be considered. A change in position of a ligament or tendon relative to the magnetic field can induce increased signal intensity due to the magic angle effect. To assess if positional rotation of the foot in the solar plane could be responsible for artifactual changes in signal intensity in the collateral ligaments of the distal interphalangeal joint and in the deep digital flexor tendon. Six isolated equine feet were imaged with a standing equine magnetic resonance system in 9 different positions with different degrees of rotation in the solar plane. Rotation of the limb induced a linear hyperintense signal on all feet at the palmar aspect of one of the lobes of the deep digital flexor tendon and at the dorsal aspect of the other lobe. Changes in signal intensity in the collateral ligaments of the distal interphalangeal joint occurred with rotation of the limb only in those feet where mediolateral hoof imbalance was present. The position and conformation of the foot influence the signal intensity in the deep digital flexor tendon and in the collateral ligaments of the distal interphalangeal joint. The significance of increased signal intensity in the deep digital flexor tendon and in the collateral ligaments of the distal interphalangeal joint should be interpreted with regard to the position and the conformation of the foot.

Systematic Quantification of Stabilizing Effects of Subtalar Joint Soft-Tissue Constraints in a Novel Cadaveric Model.

PubMed

Pellegrini, Manuel J; Glisson, Richard R; Wurm, Markus; Ousema, Paul H; Romash, Michael M; Nunley, James A; Easley, Mark E

2016-05-18

Distinguishing between ankle instability and subtalar joint instability is challenging because the contributions of the subtalar joint's soft-tissue constraints are poorly understood. This study quantified the effects on joint stability of systematic sectioning of these constraints followed by application of torsional and drawer loads simulating a manual clinical examination. Subtalar joint motion in response to carefully controlled inversion, eversion, internal rotation, and external rotation moments and multidirectional drawer forces was quantified in fresh-frozen cadaver limbs. Sequential measurements were obtained under axial load approximating a non-weight-bearing clinical setting with the foot in neutral, 10° of dorsiflexion, and 10° and 20° of plantar flexion. The contributions of the components of the inferior extensor retinaculum were documented after incremental sectioning. The calcaneofibular, cervical, and interosseous talocalcaneal ligaments were then sectioned sequentially, in two different orders, to produce five different ligament-insufficiency scenarios. Incremental detachment of the components of the inferior extensor retinaculum had no effect on subtalar motion independent of foot position. Regardless of the subsequent ligament-sectioning order, significant motion increases relative to the intact condition occurred only after transection of the calcaneofibular ligament. Sectioning of this ligament produced increased inversion and external rotation, which was most evident with the foot dorsiflexed. Calcaneofibular ligament disruption results in increases in subtalar inversion and external rotation that might be detectable during a manual examination. Insufficiency of other subtalar joint constraints may result in motion increases that are too subtle to be perceptible. If calcaneofibular ligament insufficiency is established, its reconstruction or repair should receive priority over that of other ankle or subtalar periarticular soft-tissue structures. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

The biomechanical influence of the deltotrapezoid fascia on horizontal and vertical acromioclavicular joint stability.

PubMed

Pastor, M F; Averbeck, A K; Welke, B; Smith, T; Claassen, L; Wellmann, M

2016-04-01

Many studies have investigated the biomechanical influence of the acromioclavicular (AC) and coracoclavicular (CC) ligaments on the stability of the acromioclavicular joint (ACJ). It has been shown that augmentation of the CC ligaments alone can result in residual horizontal instability. Our hypothesis was that the DTF would have a significant stabilizing effect on horizontal ACJ stability. In a biomechanical in vitro study a sequential injury of the ACJ was created on eight shoulders from full body, which were placed in an upright sitting position. The translation and rotation of the clavicle were measured in relation to the acromion using an optical navigation system in various states during thoracic-humeral elevation, abduction, and horizontal adduction. The three states were: an intact shoulder, complete sectioning of the AC ligaments, and a circular lesion of the DTF. Compared to the intact state we found a significant increase in anterior rotation of the clavicle of 1.11° (p = 0.012) and a tendency in lateral translation of 2.71 mm (p = 0.017) in relation to the acromion, with a combined lesion of AC ligaments and DTF. No significant differences were found between the intact state and the isolated dissected AC ligaments as well in adduction as elevation. A combined lesion of the AC ligaments and the DTF resulted in a quantitatively small but significant increase in anterior rotation and a tendency in lateral translation of the clavicle in relation to the acromion. These differences were quantitatively small, so that the clinical relevance of the stabilization effect of combined AC ligaments and DTF injuries is questionable.

A Comparison of 2 Tibial Inserts of Different Constraint for Cruciate-Retaining Primary Total Knee Arthroplasty: An Additional Tool for Balancing the Posterior Cruciate Ligament.

PubMed

Emerson, Roger H; Barrington, John W; Olugbode, Seun A; Alnachoukati, Omar K

2016-02-01

Frequently, a normal posterior-cruciate ligament (PCL) is removed at the surgeon's discretion, converting the normal 4-ligament knee to a 2-ligament knee, thus eliminating the need to balance all 4 ligaments. The development of modular tibial components has led to the availability of differing polyethylene inserts that permit adjustment to the flexion gap independent of the extension gap, permitting PCL balancing not previously available. The purpose of this study is to analyze a specific cruciate-retaining (CR) prosthesis which has 2 polyethylene inserts intended for CR knee use. Between February 2004 and February 2013, the senior author (R.H.E.) has performed 930 total knee arthroplasties using the CR flat insert and 424 knees using the CR lipped insert. The inserts were selected during surgery, based on the assessed tension and function of the PCL. The patients were followed up as part of a prospective total joint program with the Knee Society clinical scoring, range of motion, complications, revisions, preoperative coronal deformity, gender, body mass index, and status of the anterior-cruciate ligament intraoperatively. The average Knee Score was 92.4 for the flat group and 92.1 for the lipped group. Average knee flexion was 116.2° for the flat group and 114.4° for the lipped group (P=.2). Average knee extension (flexion deformity) was 2.1° for the flat group and 0.9° for the lipped group The results reported here show that clinical outcomes and survivorship were no different for either insert option, leading to indirect evidence that appropriate soft tissue balance had been achieved. Published by Elsevier Inc.

Triphasic scaffolds for the regeneration of the bone-ligament interface.

PubMed

Criscenti, G; Longoni, A; Di Luca, A; De Maria, C; van Blitterswijk, C A; Vozzi, G; Moroni, L

2016-01-29

A triphasic scaffold (TPS) for the regeneration of the bone-ligament interface was fabricated combining a 3D fiber deposited polycaprolactone structure and a polylactic co-glycolic acid electrospun. The scaffold presented a gradient of physical and mechanical properties which elicited different biological responses from human mesenchymal stem cells. Biological test were performed on the whole TPS and on scaffolds comprised of each single part of the TPS, considered as the controls. The TPS showed an increase of the metabolic activity with culturing time that seemed to be an average of the controls at each time point. The importance of differentiation media for bone and ligament regeneration was further investigated. Metabolic activity analysis on the different areas of the TPS showed a similar trend after 7 days in both differentiation media. Total alkaline phosphatase (ALP) activity analysis showed a statistically higher activity of the TPS in mineralization medium compared to the controls. A different glycosaminoglycans amount between the TPS and its controls was detected, displaying a similar trend with respect to ALP activity. Results clearly indicated that the integration of electrospinning and additive manufacturing represents a promising approach for the fabrication of scaffolds for the regeneration of tissue interfaces, such as the bone-to-ligament one, because it allows mimicking the structural environment combining different biomaterials at different scales.

Anticipatory effects on anterior cruciate ligament loading during sidestep cutting.

PubMed

Weinhandl, Joshua T; Earl-Boehm, Jennifer E; Ebersole, Kyle T; Huddleston, Wendy E; Armstrong, Brian S R; O'Connor, Kristian M

2013-07-01

A key to understanding potential anterior cruciate ligament injury mechanisms is to determine joint loading characteristics associated with an injury-causing event. However, direct measurement of anterior cruciate ligament loading during athletic tasks is invasive. Thus, previous research has been unable to study the association between neuromuscular variables and anterior cruciate ligament loading. Therefore, the purpose of this study was to determine the influence of movement anticipation on anterior cruciate ligament loading using a musculoskeletal modeling approach. Twenty healthy recreationally active females were recruited to perform anticipated and unanticipated sidestep cutting. Three-dimensional kinematics and kinetics of the right leg were calculated. Muscle, joint and anterior cruciate ligament forces were then estimated using a musculoskeletal model. Dependent t-tests were conducted to investigate differences between the two cutting conditions. ACL loading significantly increased during unanticipated sidestep cutting (p<0.05). This increase was primarily due to a significant increase in the sagittal plane ACL loading, which contributed 62% of the total loading. Frontal plane ACL loading contributed 26% and transverse plane ACL loading contributed 12%. These results suggest that anterior cruciate ligament loading resulted from a multifaceted interaction of the sagittal plane shear forces (i.e., quadriceps, hamstrings, and tibiofemoral), as well as the frontal and transverse plane knee moments. Additionally, the results of this study confirm the hypothesis in the current literature that unanticipated movements such as sidestep cutting increase anterior cruciate ligament loading. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhanced Medial Collateral Ligament Healing using Mesenchymal Stem Cells: Dosage Effects on Cellular Response and Cytokine Profile

PubMed Central

Saether, Erin E.; Chamberlain, Connie S.; Leiferman, Ellen M.; Kondratko-Mittnacht, Jaclyn R.; Li, Wan Ju; Brickson, Stacey L.; Vanderby, Ray

2013-01-01

Mesenchymal stem cells (MSCs) have potential therapeutic applications for musculoskeletal injuries due to their ability to differentiate into several tissue cell types and modulate immune and inflammatory responses. These immune-modulatory properties were examined in vivo during early stage rat medial collateral ligament healing. Two different cell doses (low dose 1×106 or high dose 4×106 MSCs) were administered at the time of injury and compared with normal ligament healing at days 5 and 14 post-injury. At both times, the high dose MSC group demonstrated a significant decrease in M2 macrophages compared to controls. At day 14, fewer M1 macrophages were detected in the low dose group compared to the high dose group. These results, along with significant changes in procollagen I, proliferating cells, and endothelialization suggest that MSCs can alter the cellular response during healing in a dose-dependent manner. The higher dose ligaments also had increased expression of several pro-inflammatory cytokines at day 5 (IL-1β, IFNγ, IL-2) and increased expression of IL-12 at day 14. Mechanical testing at day 14 revealed increased failure strength and stiffness in low dose ligaments compared to controls. Based on these improved mechanical properties, MSCs enhanced functional healing when applied at a lower dose. Different doses of MSCs uniquely affected the cellular response and cytokine expression in healing ligaments. Interestingly, the lower dose of cells proved to be most effective in improving functional properties. PMID:24174129

Experimental and Computational Investigation of Viscoelasticity of Native and Engineered Ligament and Tendon

NASA Astrophysics Data System (ADS)

Ma, J.; Narayanan, H.; Garikipati, K.; Grosh, K.; Arruda, E. M.

The important mechanisms by which soft collagenous tissues such as ligament and tendon respond to mechanical deformation include non-linear elasticity, viscoelasticity and poroelasticity. These contributions to the mechanical response are modulated by the content and morphology of structural proteins such as type I collagen and elastin, other molecules such as glycosaminoglycans, and fluid. Our ligament and tendon constructs, engineered from either primary cells or bone marrow stromal cells and their autogenous matricies, exhibit histological and mechanical characteristics of native tissues of different levels of maturity. In order to establish whether the constructs have optimal mechanical function for implantation and utility for regenerative medicine, constitutive relationships for the constructs and native tissues at different developmental levels must be established. A micromechanical model incorporating viscoelastic collagen and non-linear elastic elastin is used to describe the non-linear viscoelastic response of our homogeneous engineered constructs in vitro. This model is incorporated within a finite element framework to examine the heterogeneity of the mechanical responses of native ligament and tendon.

Induction of non-apoptotic cell death by morphinone in human promyelocytic leukemia HL-60 cells.

PubMed

Takeuchi, Risa; Hoshijima, Hiroshi; Nagasaka, Hiroshi; Chowdhury, Shahead Ali; Kikuchi, Hirotaka; Kanda, Yumiko; Kunii, Shiro; Kawase, Masami; Sakagami, Hiroshi

2006-01-01

As previously suggested, codeinone (oxidation product of codeine) induces non-apoptotic cell death, characterized by marginal caspase activation and the lack of DNA fragmentation in HL-60 human promyelocytic leukemia cells, which was inhibited by N-acetyl-L-cysteine. Whether, morphinone, an oxidative metabolite of morphine, also induced a similar type of cell death in HL-60 cells was investigated. Morphinone showed slightly higher cytotoxic activity against human tumor cell lines (oral squamous cell carcinoma HSC-2, HSC-3, HSC-4, NA, Ca9-22, promyelocytic leukemia HL-60, cervical carcinoma HeLa) than against normal oral human cells (gingival fibroblast HGF, pulp cells HPC, periodontal ligament fibroblast HPLF). Morphinone also induced an almost undetectable level of internucleosomal DNA fragmentation in the HL-60 cells. Morphinone did not activate caspase-8 or -9 in these cells. Morphinone dose-dependently activated caspase-3 in both HL-60 and HSC-2 cell lines, but to a much lesser extent than actinomycin D. Electron microscopy demonstrated that morphinone induced mitochondrial shrinkage, vacuolization and production of autophagosome and the loss of cell surface microvilli, without destruction of cell surface and nuclear membranes in the HL-60 cells. The autophagy inhibitor 3-methyladenine (0.3-10 mM) slightly inhibited the morphinone-induced cytotoxicity, when corrected for its own cytotoxicity. These data suggest that morphinone induces non-apoptotic cell death in HL-60 cells.

Psychological Stress Delays Periodontitis Healing in Rats: The Involvement of Basic Fibroblast Growth Factor

PubMed Central

Zhao, Ya-Juan; Li, Qiang; Cheng, Bai-Xiang; Zhang, Min; Chen, Yong-Jin

2012-01-01

Objective. To evaluate the effects of psychological stress on periodontitis healing in rats and the contribution of basic fibroblast growth factor (bFGF) expression to the healing process. Methods. Ninety-six rats were randomly distributed into control group, periodontitis group, and periodontitis plus stress group. Then, the rats were sacrificed at baseline and week(s) 1, 2, and 4. The periodontitis healing condition was assessed, and the expression of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and bFGF were tested by immunohistochemistry. Results. The stressed rats showed reduced body weight gain, behavioral changes, and increased serum corticosterone and ACTH levels (P < 0.05). The surface of inflammatory infiltrate, alveolar bone loss, attachment loss, and expression of IL-1β and TNF-α in the stress group were higher than those in the periodontitis group at weeks 2 and 4 (P < 0.05). Rats with experimental periodontitis showed decreased bFGF expression (P < 0.05), and the recovery of bFGF expression in the stress group was slower than that in the periodontitis group (P < 0.05). Negative correlations between inflammatory cytokines and bFGF were detected. Conclusion. Psychological stress could delay periodontitis healing in rats, which may be partly mediated by downregulation of the expression of bFGF in the periodontal ligament. PMID:23326020

E-cigarettes and flavorings induce inflammatory and pro-senescence responses in oral epithelial cells and periodontal fibroblasts.

PubMed

Sundar, Isaac K; Javed, Fawad; Romanos, Georgios E; Rahman, Irfan

2016-11-22

Electronic-cigarettes (e-cigs) represent a significant and increasing proportion of tobacco product consumption, which may pose an oral health concern. Oxidative/carbonyl stress via protein carbonylation is an important factor in causing inflammation and DNA damage. This results in stress-induced premature senescence (a state of irreversible growth arrest which re-enforces chronic inflammation) in gingival epithelium, which may contribute to the pathogenesis of oral diseases. We show that e-cigs with flavorings cause increased oxidative/carbonyl stress and inflammatory cytokine release in human periodontal ligament fibroblasts, Human Gingival Epithelium Progenitors pooled (HGEPp), and epigingival 3D epithelium. We further show increased levels of prostaglandin-E2 and cycloxygenase-2 are associated with upregulation of the receptor for advanced glycation end products (RAGE) by e-cig exposure-mediated carbonyl stress in gingival epithelium/tissue. Further, e-cigs cause increased oxidative/carbonyl and inflammatory responses, and DNA damage along with histone deacetylase 2 (HDAC2) reduction via RAGE-dependent mechanisms in gingival epithelium. A greater response is elicited by flavored e-cigs. Increased oxidative stress, pro-inflammatory and pro-senescence responses (DNA damage and HDAC2 reduction) can result in dysregulated repair due to proinflammatory and pro-senescence responses in periodontal cells. These data highlight the pathologic role of e-cig aerosol and its flavoring to cells and tissues of the oral cavity in compromised oral health.

The fibroblast surface markers FAP, anti-fibroblast, and FSP are expressed by cells of epithelial origin and may be altered during epithelial-to-mesenchymal transition.

PubMed

Kahounová, Zuzana; Kurfürstová, Daniela; Bouchal, Jan; Kharaishvili, Gvantsa; Navrátil, Jiří; Remšík, Ján; Šimečková, Šárka; Študent, Vladimír; Kozubík, Alois; Souček, Karel

2017-04-06

The identification of fibroblasts and cancer-associated fibroblasts from human cancer tissue using surface markers is difficult, especially because the markers used currently are usually not expressed solely by fibroblasts, and the identification of fibroblast-specific surface molecules is still under investigation. It was aimed to compare three commercially available antibodies in the detection of different surface epitopes of fibroblasts (anti-fibroblast, fibroblast activation protein α, and fibroblast surface protein). The specificity of their expression, employing fibroblast cell lines and tumor-derived fibroblasts from breast and prostate tissues was investigated. Both the established fibroblast cell line HFF-1 and ex vivo primary fibroblasts isolated from breast and prostate cancer tissues expressed the tested surface markers to different degrees. Surprisingly, those markers were expressed also by permanent cell lines of epithelial origin, both benign and cancer-derived (breast-cell lines MCF 10A, HMLE and prostate-cell lines BPH-1, DU 145, and PC-3). The expression of fibroblast activation protein α increased on the surface of previously described models of epithelial cells undergoing epithelial-to-mesenchymal transition in response to treatment with TGF-β1. To prove the co-expression of the fibroblast markers on cells of epithelial origin, we used freshly dissociated human prostate and breast cancer tissues. The results confirmed the co-expression of anti-fibroblast and fibroblast surface protein on CD31/CD45-negative/EpCAM-positive epithelial cells. In summary, our data support the findings that the tested fibroblast markers are not fibroblast specific and may be expressed also by cells of epithelial origin (e.g., cells undergoing EMT). Therefore, the expression of these markers should be interpreted with caution, and the combination of several epitopes for both positive (anti-fibroblast or fibroblast activation protein α) and negative (EpCAM) identification of fibroblasts from breast and prostate tumor tissues is advised. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

Strength of bone tunnel versus suture anchor and push-lock construct in Broström repair.

PubMed

Giza, Eric; Nathe, Ryan; Nathe, Tyler; Anderson, Matthew; Campanelli, Valentina

2012-06-01

Operative treatment of mechanical ankle instability is indicated for patients who have had multiple sprains and have continued episodes of instability despite bracing and rehabilitation. Anatomic reconstruction has been shown to have improved outcomes and return to sport as compared with nonanatomic reconstruction. The use of 2 suture anchors and a push-lock anchor is equal to 2 bone tunnels in strength to failure for anatomic Broström repair. Controlled laboratory study. In 7 matched pairs of human cadaver ankles, the calcaneofibular ligament (CFL) and anterior talofibular ligament (ATFL) were incised from their origin on the fibula. A No. 2 Fiberwire suture was placed into the CFL and a separate suture into the ATFL in a running Krackow fashion with a total of 4 locking loops. In 1 ankle of the matched pair, the ligaments were repaired to their anatomic insertion with bone tunnels. In the other, 2 suture anchors were used to reattach the ligaments to their anatomic origins, and a push-lock was used proximally to reinforce these suture anchors. The ligaments were cyclically loaded 20 times and then tested to failure. Torque to failure, degrees to failure, and stiffness were measured. The authors performed a matched pair analysis. An a priori power analysis of 0.8 demonstrated 6 pairs were needed to show a difference of 30% with a 15% standard error at a significance level of .05. There was no difference in the degrees to failure, torque to failure, and stiffness. A post hoc power analysis of torque to failure showed a power of .89 with 7 samples. Power for initial stiffness was .97 with 7 samples. Eleven of 14 specimens failed at either the suture anchor or the bone tunnel. There is no statistical difference in strength or stiffness for a suture anchor and push-lock construct as compared with a bone tunnel construct for an anatomic repair of the lateral ligaments of the ankle. The use of suture anchors in lateral ligament stabilization allows for a smaller incision, less surgical dissection, and improved surgical efficiency. It is up to the discretion of the performing surgeon based on preference, ease of use, operative time, and cost profile to choose either of these constructs for anatomic repair of the lateral ligaments of the ankle. The suture repair at the ligament was significantly strong enough such that the majority of ankles failed at the bone interface.

Elevated extracellular calcium increases expression of bone morphogenetic protein-2 gene via a calcium channel and ERK pathway in human dental pulp cells

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

Tada, Hiroyuki; Nemoto, Eiji, E-mail: e-nemoto@umin.ac.jp; Kanaya, Sousuke

Dental pulp cells, which have been shown to share phenotypical features with osteoblasts, are capable of differentiating into odontoblast-like cells and generating a dentin-like mineral structure. Elevated extracellular Ca{sup 2+}Ca{sub o}{sup 2+} has been implicated in osteogenesis by stimulating the proliferation and differentiation of osteoblasts; however, the role of Ca{sub o}{sup 2+} signaling in odontogenesis remains unclear. We found that elevated Ca{sub o}{sup 2+} increases bone morphogenetic protein (BMP)-2 gene expression in human dental pulp cells. The increase was modulated not only at a transcriptional level but also at a post-transcriptional level, because treatment with Ca{sup 2+} increased the stabilitymore » of BMP-2 mRNA in the presence of actinomycin D, an inhibitor of transcription. A similar increase in BMP-2 mRNA level was observed in other human mesenchymal cells from oral tissue; periodontal ligament cells and gingival fibroblasts. However, the latter cells exhibited considerably lower expression of BMP-2 mRNA compared with dental pulp cells and periodontal ligament cells. The BMP-2 increase was markedly inhibited by pretreatment with an extracellular signal-regulated kinase (ERK) inhibitor, PD98059, and partially inhibited by the L-type Ca{sup 2+} channels inhibitor, nifedipine. However, pretreatment with nifedipine had no effect on ERK1/2 phosphorylation triggered by Ca{sup 2+}, suggesting that the Ca{sup 2+} influx from Ca{sup 2+} channels may operate independently of ERK signaling. Dental pulp cells do not express the transcript of Ca{sup 2+}-sensing receptors (CaSR) and only respond slightly to other cations such as Sr{sup 2+} and spermine, suggesting that dental pulp cells respond to Ca{sub o}{sup 2+} to increase BMP-2 mRNA expression in a manner different from CaSR and rather specific for Ca{sub o}{sup 2+} among cations.« less

The Effect of An Angiogenic Cytokine on Orthodontically Induced Inflammatory Root Resorption

PubMed Central

Seifi, Massoud; Lotfi, Ali; Badiee, Mohammad Reza; Abdolazimi, Zahra; Amdjadi, Parisa; Bargrizan, Majid

2016-01-01

Objective Orthodontically induced inflammatory root resorption (OIIRR) is an undesirable sequel of tooth movement after sterile necrosis that takes place in periodontal ligament due to blockage of blood vessels following exertion of orthodontic force. This study sought to assess the effect of an angiogenic cytokine on OIIRR in rat model. Materials and Methods In this experimental animal study, 50 rats were randomly divided into 5 groups of 10 each: E10, E100 and E1000 receiving an injection of 10, 100 and 1000 ng of basic fibroblast growth factor (bFGF), respectively, positive control group (CP) receiving an orthodontic appliance and injection of phosphate buffered saline (PBS) and the negative control group (CN) receiving only the anesthetic agent. A nickel titanium coil spring was placed between the first molar and the incisor on the right side of maxilla. Twenty-one days later, the rats were sacrificed. Histopathological sections were made to assess the number and area of resorption lacunae, number of blood vessels, osteoclasts and Howship’s lacunae. Data were statistically analyzed using ANOVA and Tukey’s honest significant difference (HSD) test. Results Number of resorption lacunae and area of resorption lacunae in E1000 (0.97 ± 0.80 and 1. 27 ± 0.01×10-3, respectively) were significantly lower than in CP (4.17 ± 0.90 and 2.77 ± 0.01×10-3, respectively, P=0.000). Number of blood vessels, osteoclasts and Howship’s lacunae were significantly higher in E1000 compared to CP (P<0.05). Conclusion Tooth movement as the outcome of bone remodeling is concomitant with the formation of sterile necrosis in the periodontal ligament following blocked blood supply. Thus, bFGF can significantly decrease the risk of root resorption by providing more oxygen and angiogenesis. PMID:27551674

Differential effect of extracellular matrix derived from papillary and reticular fibroblasts on epidermal development in vitro.

PubMed

Janson, David; Rietveld, Marion; Mahé, Christian; Saintigny, Gaëlle; El Ghalbzouri, Abdoelwaheb

2017-06-01

Papillary and reticular fibroblasts have different effects on keratinocyte proliferation and differentiation. The aim of this study was to investigate whether these effects are caused by differential secretion of soluble factors or by differential generation of extracellular matrix from papillary and reticular fibroblasts. To study the effect of soluble factors, keratinocyte monolayer cultures were grown in papillary or reticular fibroblast-conditioned medium. To study the effect of extracellular matrix, keratinocytes were grown on papillary or reticular-derived matrix. Conditioned medium from papillary or reticular fibroblasts did not differentially affect keratinocyte viability or epidermal development. However, keratinocyte viability was increased when grown on matrix derived from papillary, compared with reticular, fibroblasts. In addition, the longevity of the epidermis was increased when cultured on papillary fibroblast-derived matrix skin equivalents compared with reticular-derived matrix skin equivalents. The findings indicate that the matrix secreted by papillary and reticular fibroblasts is the main causal factor to account for the differences in keratinocyte growth and viability observed in our study. Differences in response to soluble factors between both populations were less significant. Matrix components specific to the papillary dermis may account for the preferential growth of keratinocytes on papillary dermis.

Effects of biomaterial-derived fibroblast conditioned medium on the α-amylase expression of parotid gland acinar cells.

PubMed

Chou, Ya-Shuan; Young, Tai-Horng; Lou, Pei-Jen

2015-11-01

Salivary gland cells are surrounded by a complex stromal environment, in which fibroblasts are the main cells in proximity to the gland cells. In this study, the interaction between parotid gland acinar cells (PGACs), fibroblasts, and biomaterials was investigated. We prepared different biomaterials, including chitosan, polyvinyl alcohol (PVA), poly (ethylene-co-vinyl alcohol) (EVAL), polyvinylidene fluoride (PVDF), and tissue culture polystyrene (TCPS) to culture fibroblasts and then collect their conditioned media to culture PGACs. We observed no difference in AQP3, AQP5, and E-cadherin expression among different fibroblast conditioned medium treatments. Interestingly, α-amylase expression was obviously enhanced in PGACs cultured in the presence of conditioned medium from fibroblasts cultured on PVDF. Higher neurotrophin-4 (NT-4) expression was observed in PVDF-derived fibroblast conditioned medium using a growth factor protein array assay. In addition, directly adding NT-4 into the culture medium significantly promoted α-amylase expression by PGACs. Finally, nestin and βIII-tubulin expression by fibroblasts cultured on PVDF was also enhanced. Together, these results suggest that PVDF could promote α-amylase expression by PGACs via the NT-4 produced by fibroblasts. To date, there is no effective therapy for patients with dry mouth with persistent salivary hypofunction. The study made use of different biomaterials to culture fibroblasts and then collect their conditioned media to culture PGACs. It was found that the effect of fibroblast conditioned medium from PVDF on the α-amylase expression of PGACs was obviously enhanced and higher neurotrophin-4 (NT-4) expression was found in PVDF-derived fibroblast conditioned medium. In addition, directly adding NT-4 into the culture medium significantly promoted the expression of α-amylase by PGACs and the expression of nestin and βIII-tubulin of fibroblasts after being cultured on PVDF was enhanced. Therefore, the present study represents the first description of the role of NT-4 in the expression of α-amylase of PGACs and the role of PVDF in the reprogramming fibroblasts into neural progenitor-like cells, indicating that PVDF could promote the expression of α-amylase by PGACs via the NT-4 produced by fibroblasts. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Gingival Fibroblasts Display Reduced Adhesion and Spreading on Extracellular Matrix: A Possible Basis for Scarless Tissue Repair?

PubMed Central

Guo, Fen; Carter, David E.; Mukhopadhyay, Anuradha; Leask, Andrew

2011-01-01

Unlike skin, oral gingiva do not scar in response to injury. The basis of this difference is likely to be revealed by comparing the responses of dermal and gingival fibroblasts to fibrogenic stimuli. Previously, we showed that, compared to dermal fibroblasts, gingival fibroblasts are less responsive to the potent pro-fibrotic cytokine TGFβ, due to a reduced production of endothelin-1 (ET-1). In this report, we show that, compared to dermal fibroblasts, human gingival fibroblasts show reduced expression of pro-adhesive mRNAs and proteins including integrins α2 and α4 and focal adhesion kinase (FAK). Consistent with these observations, gingival fibroblasts are less able to adhere to and spread on both fibronectin and type I collagen. Moreover, the enhanced production of ET-1 mRNA and protein in dermal fibroblasts is reduced by the FAK/src inhibitor PP2. Given our previous observations suggesting that fibrotic fibroblasts display elevated adhesive properties, our data suggest that scarring potential may be based, at least in part, on differences in adhesive properties among fibroblasts resident in connective tissue. Controlling adhesive properties may be of benefit in controlling scarring in response to tissue injury. PMID:22073262

Repair of acute injuries of the lateral ligament complex of the ankle by suture anchors

PubMed Central

Liu, Xiang-Fei; Fang, Yang; Cao, Zhong-Hua; Li, Guang-Feng; Yang, Guo-Qing

2015-01-01

Objective: The objective of this study was to investigate the clinical curative effect of stage I repair of acute injuries of the lateral ligament complex of the ankle by the application of suture anchors. Methods: We retrospectively analyzed 18 cases of III degree acute injuries of the lateral ligament complex of the ankle. Results: There were statistically significant differences in preoperative and last follow-up VAS pain scores and AOFAS ankle hind-foot function scores. The X-ray talus displacement values in the anterior drawer test and pressure anteroposterior X-ray talar tilt in the ankle talar tilt test also showed statistically significant differences. Complications occurred in 2 patients, incision surface infection in one, and postoperative lateral dorsal skin numbness in one. All these cases were cured after symptomatic treatment. At the last follow-up all patients’ ankle joint activity recovered to their preinjury function levels. Conclusion: The application of suture anchors for small incision stage I repair of the lateral collateral ligament of ankle joint degree III injury, can effectively restored the stability of ankle joint, and prevent the occurrence of chronic ankle instability complications. It is effective and feasible for the treatment of ankle joint lateral collateral ligament injuries. PMID:26885144

Ultrasound of the coracoacromial ligament in asymptomatic volunteers and patients with shoulder impingement.

PubMed

Dietrich, Tobias J; Jonczy, Maciej; Buck, Florian M; Sutter, Reto; Puskas, Gabor J; Pfirrmann, Christian Wa

2016-08-01

The coracoacromial ligament is part of the coracoacromial arch, which is considered to be involved in shoulder impingement. To compare the coracoacromial ligament on ultrasound in asymptomatic volunteers and in patients with subacromial shoulder impingement. Twenty-nine asymptomatic volunteers (mean age, 35.5 years) and 29 patients (mean age, 49.9 years) with shoulder impingement, diagnosed by experienced shoulder surgeons, were prospectively included. Two radiologists obtained and analyzed ultrasound images of the coracoacromial ligament in the longitudinal axis. The ligament thickness was 1.4 ± 0.2 mm at its midportion, 1.8 ± 0.4 mm at the coracoid, and 2.1 ± 0.6 mm at the acromion in asymptomatic volunteers compared with 1.3 ± 0.2 mm, 1.9 ± 0.5 mm, and 1.9 ± 0.5 mm in impingement patients for observer 1. The ligament length was 30.6 ± 2.4 mm in asymptomatic volunteers compared with 30.4 ± 3.6 mm in impingement patients for observer 1. An anteriorly convex shape of the superficial contour of the coracoacromial ligament was significantly more frequent in impingement patients compared with asymptomatic volunteers for both observers (observer 1: 10% (3/29) versus 45% (13/29), P value <0.01; observer 2: 10% (3/29) versus 38% (11/29), P value <0.03). The comparison of the remaining parameters of the coracoacromial ligament, such as the thickness, length, echogenicity, and fibrillation did not reveal significant differences between volunteers and patients. While thickness or length of the coracoacromial ligament were similar in volunteers and patients with shoulder impingement, an anteriorly convex shape of the superficial contour of the coracoacromial ligament was significantly more frequent in impingement patients compared with asymptomatic volunteers. © The Foundation Acta Radiologica 2015.

Magnetic resonance imaging of the alar and transverse ligaments in acute whiplash-associated disorders 1 and 2: a cross-sectional controlled study.

PubMed

Vetti, Nils; Kråkenes, Jostein; Damsgaard, Eivind; Rørvik, Jarle; Gilhus, Nils Erik; Espeland, Ansgar

2011-03-15

Cross-sectional. To describe alar- and transverse-ligament magnetic resonance imaging (MRI) high-signal changes in acute whiplash-associated disorders (WAD) grades 1 and 2 in relation to the severity and mechanics of trauma, and to compare them with controls. The alar and transverse ligaments are important stabilizers at the craniovertebral junction. Acute injury of these ligaments should be detected as high-signal changes on high-resolution MRI. In the study, 114 consecutive acute WAD 1-2 patients and 157 noninjured controls underwent upper-neck high-resolution MRI, using proton-weighted sequences and Short Tau Inversion Recovery (STIR). Two blinded radiologists independently graded high-signal changes 0 to 3 on proton images and assessed ligament high-signal intensity on STIR. Image quality was evaluated as good, reduced, or poor (not interpretable). Multiple logistic regression was used for both within- and between-groups analyses. All proton and STIR images were interpretable. Interobserver agreement for grades 2 to 3 versus grades 0 to 1 changes was moderate to good (κ = 0.71 alar; and 0.54 transverse). MRI showed grades 2 to 3 alar ligament changes in 40 (35.1%) and grades 2 to 3 transverse ligament changes in 27 (23.7%) of the patients. Such changes were related to contemporary head injury (P = 0.041 alar), neck pain (P = 0.042 transverse), and sex (P = 0.033 transverse) but did not differ between patients and controls (P = 0.433 alar; and 0.254 transverse). STIR ligament signal intensity, higher than bone marrow, was found in only three patients and one control. This first study on high-resolution MRI of craniovertebral ligaments in acute WAD 1-2 indicates that such trauma does not induce high-signal changes. Follow-up studies are needed to find out whether pretraumatic high-signal changes imply reduced ligament strength and can predict chronic WAD.

Evaluation of Transsyndesmotic Fixation and Primary Deltoid Ligament Repair in Ankle Fractures With Suspected Combined Deltoid Ligament Injury.

PubMed

Wu, Kai; Lin, Jian; Huang, Jianhua; Wang, Qiugen

2018-04-13

The present prospective study examined the utility of the intraoperative tap test/technique for distal tibiofibular syndesmosis in the diagnosis of deltoid ligament rupture and compared the outcomes of transsyndesmotic fixation to deltoid ligament repair with suture anchor. This diagnostic technique was performed in 59 ankle fractures with suspected deltoid ligament injury. The width of the medial clear space of 59 cases was evaluated to assess the sensitivity and specificity. Those with deltoid ligament rupture were randomly assigned to 2 groups and treated with deltoid ligament repair with a suture anchor or with syndesmosis screw fixation. All the patients were assessed with the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, short-form 36-item questionnaire (SF-36), and visual analog scale (VAS). The tap test was positive in 53 cases. However, surgical exploration demonstrated that 51 cases (86.4%) had a combined deltoid ligament injury and fracture. The sensitivity and specificity of the tap test was 100.0% and 75.0%, respectively. Finally, 26 cases (96.3%) in the syndesmosis screw group and 22 (91.7%) in the deltoid repair group were followed up. No statistically significant differences were found in the AOFAS ankle-hindfoot scale score, SF-36 score, or VAS score between the 2 groups. The malreduction rate in the syndesmosis screw group was 34.6% and that in the deltoid repair group was 9.09%. The tap test is an intraoperative diagnostic method to use to evaluate for deltoid ligament injury. Deltoid ligament repair with a suture anchor had good functional and radiologic outcomes comparable to those with syndesmotic screw fixation but has a lower malreduction rate. We did not encounter the issue of internal fixation failure or implant removal. Copyright © 2017 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Spiral ligament and stria vascularis changes in cochlear otosclerosis: effect on hearing level.

PubMed

Doherty, Joni K; Linthicum, Fred H

2004-07-01

To investigate the effect of changes within the spiral ligament and stria vascularis on hearing in cochlear otosclerosis, we examined spiral ligament hyalinization, stria vascularis atrophy, and sensory hearing loss in cochlear otosclerosis and described changes in ion transport molecule expression. Retrospective. Tertiary referral center. Thirty-two cochleae from 24 temporal bone donors with histologic evidence of cochlear otosclerosis, including spiral ligament hyalinization. Audiography. Measurements of spiral ligament width, stria vascularis, and bone-conduction thresholds were compared by the amount of hyalinization. Expression of the ion transport molecules Na,K-ATPase, connexin 26, and carbonic anhydrase II were assessed by immunohistochemical techniques. Hyalinization most often involved the posterior basal turn (88%) and the posterior middle turn (27%). Spiral ligament hyalinization correlated significantly with stria vascularis atrophy in the posterior middle turn of the cochlea (rho = -0.63, p < 0.01). There was a trend toward a significant association in the posterior basal turn (rho = -0.31, p < 0.08). Bone-conduction thresholds at 2,000 and 4,000 Hz were significantly associated with the amount of stria vascularis atrophy (rho = -0.44, -0.40, p < 0.05). In addition, we observed decreased immunostaining for both carbonic anhydrase II with Type I fibrocytes and Na,K-ATPase with stria vascularis and Type II and Type IV fibrocytes of the spiral ligament in cochlear otosclerosis sections compared with normal cochlea. Na,K-ATPase staining within the stria vascularis was further decreased in the presence of spiral ligament hyalinization. No significant differences were seen with connexin 26 immunostaining. However, immunostaining results were somewhat inconsistent. These data suggest that spiral ligament structure and function are essential for stria vascularis survival. In addition, dampened expression of ion transport molecules within the spiral ligament and stria vascularis may disrupt potassium ion recycling, resulting in loss of endocochlear potential and sensory hearing loss.

Determination of the normal arthroscopic anatomy of the femoropatellar and cranial femorotibial joints of cattle.

PubMed

Nichols, Sylvain; Anderson, David E

2014-03-01

The arthroscopic approach and anatomy of the bovine femoropatellar and femorotibial joints are described. A 4-mm diameter, 15-cm long arthroscope with a 30° forward angle view was used. The structures viewed were recorded according to the position of the arthroscope within the joint. The femoropatellar joint was best accessed via a lateral approach, between the middle and lateral patellar ligaments. The axial portion of the medial femorotibial joint was viewed from a medial approach between the middle and medial patellar ligaments and the abaxial portion was viewed from a lateral approach between the middle and the lateral patellar ligaments. The axial portion of the lateral femorotibial joint was viewed from a lateral approach between the middle and the lateral patellar ligaments and the abaxial portion was viewed from a medial approach between the middle and medial patellar ligaments. The results of this study provide guidelines regarding the location of arthroscopic portals to evaluate precisely different areas of the stifle in cattle.

Determination of the normal arthroscopic anatomy of the femoropatellar and cranial femorotibial joints of cattle

PubMed Central

Nichols, Sylvain; Anderson, David E.

2014-01-01

The arthroscopic approach and anatomy of the bovine femoropatellar and femorotibial joints are described. A 4-mm diameter, 15-cm long arthroscope with a 30° forward angle view was used. The structures viewed were recorded according to the position of the arthroscope within the joint. The femoropatellar joint was best accessed via a lateral approach, between the middle and lateral patellar ligaments. The axial portion of the medial femorotibial joint was viewed from a medial approach between the middle and medial patellar ligaments and the abaxial portion was viewed from a lateral approach between the middle and the lateral patellar ligaments. The axial portion of the lateral femorotibial joint was viewed from a lateral approach between the middle and the lateral patellar ligaments and the abaxial portion was viewed from a medial approach between the middle and medial patellar ligaments. The results of this study provide guidelines regarding the location of arthroscopic portals to evaluate precisely different areas of the stifle in cattle. PMID:24587506

The influence of the mechanical behaviour of the middle ear ligaments: a finite element analysis.

PubMed

Gentil, F; Parente, M; Martins, P; Garbe, C; Jorge, R N; Ferreira, A; Tavares, João Manuel R S

2011-01-01

The interest in computer modelling of biomechanical systems, mainly by using the finite element method (FEM), has been increasing, in particular for analysis of the mechanical behaviour of the human ear. In this work, a finite element model of the middle ear was developed to study the dynamic structural response to harmonic vibrations for distinct sound pressure levels applied on the eardrum. The model includes different ligaments and muscle tendons with elastic and hyperelastic behaviour for these supportive structures. Additionally, the nonlinear behaviour of the ligaments and muscle tendons was investigated, as they are the connection between ossicles by contact formulation. Harmonic responses of the umbo and stapes footplate displacements, between 100 Hz and 10 kHz, were obtained and compared with previously published work. The stress state of ligaments (superior, lateral, and anterior of malleus and superior and posterior of incus) was analysed, with the focus on balance of the supportive structures of the middle ear, as ligaments make the link between the ossicular chain and the walls of the tympanic cavity. The results obtained in this work highlight the importance of using hyperelastic models to simulate the mechanical behaviour for the ligaments and tendons.

Restoration of horizontal stability in complete acromioclavicular joint separations: surgical technique and preliminary results.

PubMed

Li, Haoqing; Wang, Chuanshun; Wang, Jiandong; Wu, Kai; Hang, Donghua

2013-11-13

Our purpose was to investigate the clinical efficacy of arthroscope-assisted acromioclavicular ligament reconstruction in combination with double endobutton coracoclavicular ligament reconstruction for the treatment of complete acromioclavicular joint dislocation. During the period from February 2010 to October 2012, ten patients with Rockwood types IV and V acromioclavicular joint dislocation were hospitalized and nine were treated with acromioclavicular ligament reconstruction combined with double endobutton of coracoclavicular ligament reconstruction. The improvement in shoulder functions was assessed using a Constant score and visual analog scale (VAS) system. The mean follow-up period was 33.6 ± 5.4 months. The mean Constant scores improved from 25.2 ± 6.6 preoperatively to 92.4 ± 6.5 postoperatively, while the mean VAS score decreased from 5.9 ± 1.4 to 1.2 ± 0.9; significant differences were observed. The final follow-up revealed that excellent outcomes were achieved in eight patients and good outcome in two patients. Arthroscope-assisted acromioclavicular ligament reconstruction in combination with double endobutton of coracoclavicular ligament reconstruction is an effective approach for treatment of acute complete acromioclavicular joint dislocation.

Restoration of horizontal stability in complete acromioclavicular joint separations: surgical technique and preliminary results

PubMed Central

2013-01-01

Background Our purpose was to investigate the clinical efficacy of arthroscope-assisted acromioclavicular ligament reconstruction in combination with double endobutton coracoclavicular ligament reconstruction for the treatment of complete acromioclavicular joint dislocation. Methods During the period from February 2010 to October 2012, ten patients with Rockwood types IV and V acromioclavicular joint dislocation were hospitalized and nine were treated with acromioclavicular ligament reconstruction combined with double endobutton of coracoclavicular ligament reconstruction. The improvement in shoulder functions was assessed using a Constant score and visual analog scale (VAS) system. Results The mean follow-up period was 33.6 ± 5.4 months. The mean Constant scores improved from 25.2 ± 6.6 preoperatively to 92.4 ± 6.5 postoperatively, while the mean VAS score decreased from 5.9 ± 1.4 to 1.2 ± 0.9; significant differences were observed. The final follow-up revealed that excellent outcomes were achieved in eight patients and good outcome in two patients. Conclusion Arthroscope-assisted acromioclavicular ligament reconstruction in combination with double endobutton of coracoclavicular ligament reconstruction is an effective approach for treatment of acute complete acromioclavicular joint dislocation. PMID:24225119

The effect of epidermal growth factor on neonatal incisor differentiation in the mouse.

PubMed

Topham, R T; Chiego, D J; Gattone, V H; Hinton, D A; Klein, R M

1987-12-01

The effect of epidermal growth factor (EGF) on cellular differentiation of the neonatal mouse mandibular incisor was examined autoradiographically using tritiated thymidine ([3H]TDR) and tritiated proline ([3H]PRO). On days 0 (day of birth), 1, and 2, EGF was administered (3 micrograms/g body wt) sc to neonates. Mice were killed on Days 1, 4, 7, 10, and 13 after birth and were injected with either [3H]TDR or [3H]PRO 1 hr before death. [3H]TDR was used to analyze cell proliferation in eight cell types in the developing mouse incisor including upper (lingual) and lower (buccal) pulpal fibroblasts, preodontoblasts, inner and outer enamel epithelial cells (IEE and OEE), stratum intermedium (SI), stellate reticulum (SR), and periodontal ligament (PDL) fibroblasts. [3H]PRO was used to analyze protein synthesis in ameloblasts, and their secretion products (enamel and dentin), as well as PDL fibroblasts. The selected EGF injection scheme elicited acceleration of incisor eruption with minimal growth retardation. At Day 1, the upper and lower pulp, preodontoblasts, SI, and SR showed a significant decrease in labeling index (LI) 24 hr after a single EGF injection. After multiple injections (Days 0, 1, 2), two LI patterns were observed. In lower pulp, preodontoblasts, IEE, SI, SR, and OEE, a posteruptive change in LI was observed. In contrast, the upper pulp and PDL regions demonstrated a direct temporal relationship with eruption. Autoradiographic analysis with [3H]PRO indicated that EGF treatment caused significant increases in grain counts per unit area in ameloblast, odontoblast, and PDL regions studied. Significant differences were found in all four regions studied (ameloblasts, enamel, odontoblasts, dentin) at the 45-microns-tall ameloblast level as well as ameloblasts and odontoblasts at the 30-microns level at 13 days of age. The PDL demonstrated significant differences at all locations studied (base, 30 microns, 45 microns,) in 4-, 7-, and 13-day-old mice. Morphologically, EGF-treated groups demonstrated premature differentiation of ameloblasts and odontoblasts at the light microscopic level. The data indicate that EGF alters DNA and protein synthesis as well as differentiation patterns during the eruption process. While EGF affects both DNA and protein synthesis, the alteration of differentiation may be secondary to mitogenic effects on proliferative compartments. In order to determine the cellular target for EGF within the newborn mouse incisor, in vivo 125I-EGF binding was analyzed autoradiographically.(ABSTRACT TRUNCATED AT 400 WORDS)

A comparative study on the breakup of Newtonian and viscoelastic liquid films

NASA Astrophysics Data System (ADS)

Qian, Lijuan; Song, Shaobo; Jiang, Lisha; Li, Xiaolu; Lin, Jianzhong

2018-05-01

The breakup of viscoelastic liquid films are investigated experimentally and analytically. The breakup phenomena of viscoelastic liquid film are recorded by the time resolved high speed camera. Video images reveal the difference behavior of liquid bubble breakup for Newtonian and viscoelastic liquid. For the Newtonian liquid, cylindrical ligaments are stretched into droplets with large distributions of drop size. For the viscoelastic liquid, the pinch-off point is located on the liquid connections to the nozzle and finally the main part of the ligament no longer elongates. Furthermore, a dispersion relation based on the stability analysis is involved to predict the ligament length and drop mean size after breakup for liquid film. The calculated ligament length is validated by the measured drop mean size at higher air-to-liquid mass flow ratio.

Alteration of Skin Properties with Autologous Dermal Fibroblasts

PubMed Central

Thangapazham, Rajesh L.; Darling, Thomas N.; Meyerle, Jon

2014-01-01

Dermal fibroblasts are mesenchymal cells found between the skin epidermis and subcutaneous tissue. They are primarily responsible for synthesizing collagen and glycosaminoglycans; components of extracellular matrix supporting the structural integrity of the skin. Dermal fibroblasts play a pivotal role in cutaneous wound healing and skin repair. Preclinical studies suggest wider applications of dermal fibroblasts ranging from skin based indications to non-skin tissue regeneration in tendon repair. One clinical application for autologous dermal fibroblasts has been approved by the Food and Drug Administration (FDA) while others are in preclinical development or various stages of regulatory approval. In this context, we outline the role of fibroblasts in wound healing and discuss recent advances and the current development pipeline for cellular therapies using autologous dermal fibroblasts. The microanatomic and phenotypic differences of fibroblasts occupying particular locations within the skin are reviewed, emphasizing the therapeutic relevance of attributes exhibited by subpopulations of fibroblasts. Special focus is provided to fibroblast characteristics that define regional differences in skin, including the thick and hairless skin of the palms and soles as compared to hair-bearing skin. This regional specificity and functional identity of fibroblasts provides another platform for developing regional skin applications such as the induction of hair follicles in bald scalp or alteration of the phenotype of stump skin in amputees to better support their prosthetic devices. PMID:24828202

Fibrogenic Lung Injury Induces Non-Cell-Autonomous Fibroblast Invasion.

PubMed

Ahluwalia, Neil; Grasberger, Paula E; Mugo, Brian M; Feghali-Bostwick, Carol; Pardo, Annie; Selman, Moisés; Lagares, David; Tager, Andrew M

2016-06-01

Pathologic accumulation of fibroblasts in pulmonary fibrosis appears to depend on their invasion through basement membranes and extracellular matrices. Fibroblasts from the fibrotic lungs of patients with idiopathic pulmonary fibrosis (IPF) have been demonstrated to acquire a phenotype characterized by increased cell-autonomous invasion. Here, we investigated whether fibroblast invasion is further stimulated by soluble mediators induced by lung injury. We found that bronchoalveolar lavage fluids from bleomycin-challenged mice or patients with IPF contain mediators that dramatically increase the matrix invasion of primary lung fibroblasts. Further characterization of this non-cell-autonomous fibroblast invasion suggested that the mediators driving this process are produced locally after lung injury and are preferentially produced by fibrogenic (e.g., bleomycin-induced) rather than nonfibrogenic (e.g., LPS-induced) lung injury. Comparison of invasion and migration induced by a series of fibroblast-active mediators indicated that these two forms of fibroblast movement are directed by distinct sets of stimuli. Finally, knockdown of multiple different membrane receptors, including platelet-derived growth factor receptor-β, lysophosphatidic acid 1, epidermal growth factor receptor, and fibroblast growth factor receptor 2, mitigated the non-cell-autonomous fibroblast invasion induced by bronchoalveolar lavage from bleomycin-injured mice, suggesting that multiple different mediators drive fibroblast invasion in pulmonary fibrosis. The magnitude of this mediator-driven fibroblast invasion suggests that its inhibition could be a novel therapeutic strategy for pulmonary fibrosis. Further elaboration of the molecular mechanisms that drive non-cell-autonomous fibroblast invasion consequently may provide a rich set of novel drug targets for the treatment of IPF and other fibrotic lung diseases.

Training for Women's Basketball: A Biomechanical Emphasis for Preventing Anterior Cruciate Ligament Injury.

ERIC Educational Resources Information Center

Pettitt, Robert W.; Bryson, Erin R.

2002-01-01

Summarizes proposed variables linked with higher incidences of anterior cruciate ligament tears in females and the biomechanical aspects of the lower extremity during the performance of common basketball skills, focusing on gender differences in knee joint stability and neuromuscular control, biomechanical aspects of lower extremity skills in…

Interrelation of creep and relaxation: a modeling approach for ligaments.

PubMed

Lakes, R S; Vanderby, R

1999-12-01

Experimental data (Thornton et al., 1997) show that relaxation proceeds more rapidly (a greater slope on a log-log scale) than creep in ligament, a fact not explained by linear viscoelasticity. An interrelation between creep and relaxation is therefore developed for ligaments based on a single-integral nonlinear superposition model. This interrelation differs from the convolution relation obtained by Laplace transforms for linear materials. We demonstrate via continuum concepts of nonlinear viscoelasticity that such a difference in rate between creep and relaxation phenomenologically occurs when the nonlinearity is of a strain-stiffening type, i.e., the stress-strain curve is concave up as observed in ligament. We also show that it is inconsistent to assume a Fung-type constitutive law (Fung, 1972) for both creep and relaxation. Using the published data of Thornton et al. (1997), the nonlinear interrelation developed herein predicts creep behavior from relaxation data well (R > or = 0.998). Although data are limited and the causal mechanisms associated with viscoelastic tissue behavior are complex, continuum concepts demonstrated here appear capable of interrelating creep and relaxation with fidelity.

Parameters of Microcirculation in the Broad Ligament of the Uterus in Wistar Rats after Injection of Autologous Biomedical Cell Product.

PubMed

Dergacheva, T I; Lykov, A P; Shurlygina, A V; Starkova, E V; Poveshchenko, O V; Bondarenko, N A; Kim, I I; Tenditnik, M V; Borodin, Yu I; Konenkov, V I

2015-10-01

We studied the effects of autologous biomedical cell product (bone marrow multipotent mesenchymal stromal cells and their conditioned media) on the parameters of the microcirculatory bed in the broad ligament of the uterus of normal Wistar rats were studied. The parameters of microcirculation and lymph drainage in the broad ligament changed in opposite directions in response to injection of autologous biomedical cell product via different routes. This fact should be taken into consideration when prescribing cell therapy for inflammatory degenerative processes in the pelvic organs.

The attachment of collagenous ligament to stereom in primary spines of the sea-urchin, Eucidaris tribuloides.

PubMed

Smith, D S; Del Castillo, J; Morales, M; Luke, B

1990-01-01

The similar proximal and distal attachments to the stereom of primary spine ligament in the echinoid Eucidaris tribuloides are described, from thin sections and SEM studies on frozen and fractured spine articulations and ligaments from decalcified material. The orthogonal structure of the general stereom is modified on the attachment zones where bundles of collagen cylinders enter approximately hexagonally arranged channels. Straps of collagen extend in parallel series between adjacent bundles via regularly placed ports and collagen loops rather than non-striated 'tendons' pass over skeletal trabeculae. The regular pattern of collagen straps is most evident on the proximal and distal attachment zones. Mechanical features of the non-adhesive mode of attachment are considered, together with similarities and differences between insertion of muscle cells and mutable collagenous tissue (ligament) in echinoderms.

Anterior Tibial Translation in Collegiate Athletes with Normal Anterior Cruciate Ligament Integrity

PubMed Central

Rosene, John M.; Fogarty, Tracey D.

1999-01-01

Objective: To examine differences in anterior tibial translation (ATT) among sports, sex, and leg dominance in collegiate athletes with normal anterior cruciate ligament integrity. Design and Setting: Subjects from various athletic teams were measured for ATT in right and left knees. Subjects: Sixty subjects were measured for ATT with a KT-1000 knee arthrometer. Measurements: Statistical analyses were computed for each sex and included a 2 × 3 × 4 mixed-factorial analysis of variance (ANOVA) for anterior cruciate ligament displacement, right and left sides, and force and sport. A 2 × 2 × 3 mixed-factorial ANOVA was computed to compare means for sex and force. A 2 × 3 mixed-factorial ANOVA was computed to compare sex differences across 3 forces. Results: For males and females, no significant interactions were found among leg, force, and sport for mean ATT, for leg and sport or leg and force, or for translation values between dominant and nondominant legs. Males had a significant interaction for force and sport, and a significant difference was found for side of body, since the right side had less translation than the left side. Females had greater ATT than males at all forces. Conclusions: Sex differences exist for ATT, and differences in ATT exist among sports for both sexes. Differences between the right and left sides of the body should be expected when making comparisons of ligamentous laxity. ImagesFigure 2.Figure 3.Figure 5. PMID:16558565

Cervical extraforaminal ligaments: an anatomical study.

PubMed

Arslan, Mehmet; Açar, Halil İbrahim; Cömert, Ayhan

2017-12-01

The purpose of this study was to elucidate the anatomy and clinical importance of extraforaminal ligaments in the cervical region. This study was performed on eight embalmed cadavers. The existence and types of extraforaminal ligaments were identified. The morphology, quantity, origin, insertion, and orientation of the extraforaminal ligaments in the cervical region were observed. Extraforaminal ligaments could be divided into two types: transforaminal ligaments and radiating ligaments. It was observed that during their course, transforaminal ligaments cross the intervertebral foramen ventrally. They usually originate from the anteroinferior margin of the anterior tubercle of the cranial transverse process and insert into the superior margin of the anterior tubercle of the caudal transverse process. The dorsal aspect of the transforaminal ligaments adhere loosely to the spinal nerve sheath. The length, width and thickness of these ligaments increased from the cranial to the caudal direction. A single intervertebral foramen contained at least one transforaminal ligament. A total of 98 ligaments in 96 intervertebral foramina were found. The spinal nerves were extraforaminally attached to neighboring anterior and posterior tubercle of the cervical transverse process by the radiating ligaments. The radiating ligaments consisted of the ventral superior, ventral, ventral inferior, dorsal superior and dorsal inferior radiating ligaments. Radiating ligaments originated from the adjacent transverse processes and inserted into the nerve root sheath. The spinal nerve was held like the hub of a wheel by a series of radiating ligaments. The dorsal ligaments were the thickest. From C2-3 to C6-7 at the cervical spine, radiating ligaments were observed. They developed particularly at the level of the C5-C6 intervertebral foramen. This anatomic study may provide a better understanding of the relationship of the extraforaminal ligaments to the cervical nerve root.

Minimal effect of patella eversion on ligament balancing in cruciate-retaining total knee arthroplasty.

PubMed

Aunan, Eirik; Kibsgård, Thomas; Röhrl, Stephan M

2017-03-01

The effect of patellar eversion on ligament laxity measurements is still unclear. The purpose of this study was to investigate the influence of patellar eversion on medial and lateral ligament laxity measurements performed intra-operatively in total knee arthroplasty (TKA). A total of 49 knees (27 female) with mean age 70 years (42-83) and mean body mass index of 28.5 were operated consecutively with a cruciate-retaining prosthesis. Medial and lateral ligament laxity in extension and in 90° of flexion was measured with the spatula-method intra-operatively after implantation of the prosthetic components with the patella everted and thereafter with the patella repositioned. The corresponding changes in gap height and inclination were calculated. A statistically significant increase of 0.6 mm (p < 0.001) in ligament laxity (condylar lift-off) laterally in flexion was found with the patella repositioned compared to everted. No differences were found in extension or medially in flexion. Correspondingly, the flexion gap increased by 0.4 mm (p < 0.001) and the flexion gap inclination increased by 0.6° (p = 0.002) when the patella was repositioned. Earlier research has shown that ligament laxity must be at least 1-2 mm to cause inferior function after TKA. In the current study, we found that the effect of patellar eversion on ligament laxity measurements is too small to be considered clinically relevant. PROSPECTIVE STUDY EVALUATING THE EFFECT OF PATIENT CHARACTERISTICS: Level II.

[Analysis of stress in periodontal ligament of the maxillary first molar on distal movement by nonlinear finite element method].

PubMed

Dong, Jing; Zhang, Zhe-chen; Zhou, Guo-liang

2015-06-01

To analyze the stress distribution in periodontal ligament of maxillary first molar during distal movement with nonlinear finite element analysis, and to compare it with the result of linear finite element analysis, consequently to provide biomechanical evidence for clinical application. The 3-D finite element model including a maxillary first molar, periodontal ligament, alveolar bone, cancellous bone, cortical bone and a buccal tube was built up by using Mimics, Geomagic, ProE and Ansys Workbench. The material of periodontal ligament was set as nonlinear material and linear elastic material, respectively. Loads of different combinations were applied to simulate the clinical situation of distalizing the maxillary first molar. There were channels of low stress in peak distribution of Von Mises equivalent stress and compressive stress of periodontal ligament in nonlinear finite element model. The peak of Von Mises equivalent stress was lower when it was satisfied that Mt/F minus Mr/F approximately equals 2. The peak of compressive stress was lower when it was satisfied that Mt/F was approximately equal to Mr/F. The relative stress of periodontal ligament was higher and violent in linear finite element model and there were no channels of low stress in peak distribution. There are channels in which stress of periodontal ligament is lower. The condition of low stress should be satisfied by applied M/F during the course of distalizing the maxillary first molar.

[Changes in pelvic organ mobility and ligamentous laxity during pregnancy and postpartum. Review of literature and prospects].

PubMed

Gachon, B; Desseauve, D; Fradet, L; Decatoire, A; Lacouture, P; Pierre, F; Fritel, X

2016-06-01

The role of pregnancy in pelvic floor disorders occurrence remains poorly known. It might exist a link between changes in ligamentous laxity and changes in pelvic organ mobility during this period. Our objective was to conduct a non-systematic review of literature about changes in pelvic organ mobility as well as in ligamentous laxity during pregnancy and postpartum. From the PubMed, Medline, Cochrane Library and Web of Science database we have selected works which pertains clinical assessment of pelvic organ mobility (pelvic organ prolapse quantification), ultrasound assessment of levator hiatus and urethral mobility, ligamentous laxity assessment during pregnancy and postpartum. Clinical assessments performed in these works show an increase of pelvic organ mobility and perineal distension during pregnancy followed by a recovery phase during postpartum. Pelvic floor imaging shows an increase of levator hiatus area and urethral mobility during pregnancy then a recovery phase in postpartum. Different authors also report an increase of ligamentous laxity (upper and lower limbs) during pregnancy followed by a decrease phase in postpartum. Pelvic organ mobility, ligamentous laxity, levator hiatus and urethral mobility change in a similarly way during pregnancy (increase of mobility or distension) and postpartum (recovery). 3. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

* Fabrication and Characterization of Biphasic Silk Fibroin Scaffolds for Tendon/Ligament-to-Bone Tissue Engineering.

PubMed

Font Tellado, Sònia; Bonani, Walter; Balmayor, Elizabeth R; Foehr, Peter; Motta, Antonella; Migliaresi, Claudio; van Griensven, Martijn

2017-08-01

Tissue engineering is an attractive strategy for tendon/ligament-to-bone interface repair. The structure and extracellular matrix composition of the interface are complex and allow for a gradual mechanical stress transfer between tendons/ligaments and bone. Thus, scaffolds mimicking the structural features of the native interface may be able to better support functional tissue regeneration. In this study, we fabricated biphasic silk fibroin scaffolds designed to mimic the gradient in collagen molecule alignment present at the interface. The scaffolds had two different pore alignments: anisotropic at the tendon/ligament side and isotropic at the bone side. Total porosity ranged from 50% to 80% and the majority of pores (80-90%) were <100-300 μm. Young's modulus varied from 689 to 1322 kPa depending on the type of construct. In addition, human adipose-derived mesenchymal stem cells were cultured on the scaffolds to evaluate the effect of pore morphology on cell proliferation and gene expression. Biphasic scaffolds supported cell attachment and influenced cytoskeleton organization depending on pore alignment. In addition, the gene expression of tendon/ligament, enthesis, and cartilage markers significantly changed depending on pore alignment in each region of the scaffolds. In conclusion, the biphasic scaffolds fabricated in this study show promising features for tendon/ligament-to-bone tissue engineering.

Dermal fibroblasts from acute inflamed atopic dermatitis lesions display increased eotaxin/CCL11 responsiveness to interleukin-4 stimulation.

PubMed

Gahr, N; Fölster-Holst, R; Weichenthal, M; Christophers, E; Schröder, J-M; Bartels, J

2011-03-01

The presence of eosinophils and/or eosinophil-derived products in the dermis is characteristic for involved skin of patients with atopic dermatitis and contributes to the observed tissue injury. CCL11 is a potent chemoattractant and activator of human eosinophils and interleukin (IL)-4 is a potent inducer of CCL11 expression in dermal fibroblasts. As increased fibroblast CCL11 expression may explain eosinophilic infiltration of involved skin areas in atopic dermatitis, we asked whether dermal fibroblasts from atopic patients differ from fibroblasts of healthy individuals in their ability to express CCL11. We compared IL-4-induced CCL11 mRNA expression using reverse transcription-polymerase chain reaction from cultured dermal fibroblasts derived from biopsies of chronic lesional and acute lesional atopic skin as well as from skin biopsies derived from normal skin of healthy donors. Considerable variability in IL-4-induced relative CCL11 mRNA expression was detected in fibroblasts derived from biopsies of different individuals. The lowest median IL-4 concentration inducing half maximal CCL11 mRNA expression (EC(50)) was found in fibroblasts derived from acute inflamed atopic lesions. Inducibility of CCL11 in dermal fibroblasts upon stimulation with Th2 cytokines explains the tissue eosinophilia observed in the presence of Th2 cytokines and the localization of eosinophils to the dermis. Decreased EC(50) values of IL-4-induced CCL11 expression in fibroblasts from acute inflamed atopic skin lesions indicates increased IL-4 responsiveness in these lesions and further substantiates the special role for IL-4-induced dermal fibroblast CCL11 expression in acute lesions. Variable CCL11 expression in fibroblasts from different patients with atopic dermatitis indicates heterogeneity of factors determining atopic phenotype in atopic dermatitis. © 2011 The Authors. BJD © 2011 British Association of Dermatologists.

Mastication and the Postorbital Ligament: Dynamic Strain in Soft Tissues

PubMed Central

Herring, Susan W.; Rafferty, Katherine L.; Liu, Zi Jun; Lemme, Michael

2011-01-01

Although the FEED database focuses on muscle activity patterns, it is equally suitable for other physiological recording and especially for synthesizing different types of information. The present contribution addresses the interaction between muscle activity and ligamentary stretch during mastication. The postorbital ligament is the thickened edge of a septum dividing the orbital contents from the temporal fossa and is continuous with the temporal fascia. As a tensile element, this fascial complex could support the zygomatic arch against the pull of the masseter muscle. An ossified postorbital bar has evolved repeatedly in mammals, enabling resistance to compression and shear in addition to tension. Although such ossification clearly reinforces the skull against muscle pull, the most accepted explanation is that it helps isolate the orbital contents from contractions of the temporalis muscle. However, it has never been demonstrated that the contraction of jaw muscles deforms the unossified ligament. We examined linear deformation of the postorbital ligament in minipigs, Sus scrofa, along with electromyography of the jaw muscles and an assessment of changes in pressure and shape in the temporalis. During chewing, the ligament elongated (average 0.9%, maximum 2.8%) in synchrony with the contraction of the elevator muscles of the jaw. Although the temporalis bulged outward and created substantial pressure against the braincase, the superficial fibers usually retracted caudally, away from the postorbital ligament. In anesthetized animals, stimulating either the temporalis or the masseter muscle in isolation usually elongated the ligament (average 0.4–0.7%). These results confirm that contraction of the masticatory muscles can potentially distort the orbital contents and further suggest that the postorbital ligament does function as a tension member resisting the pull of the masseter on the zygomatic arch. PMID:21593142

[Extracellular signal-regulated kinase signaling pathway regulates the endothelial differentiation of periodontal ligament stem cells].

PubMed

Zhu, Hong; Luo, Lankun; Wang, Ying; Tan, Jun; Xue, Peng; Wang, Qintao

2016-03-01

To investigate the effect of extracellular signal-regulated kinase (ERK) signaling pathway on the endothelial differentiation of periodontal ligament stem cells (PDLSC). Human PDLSC was cultured in the medium with vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) to induce endothelial differentiation. Endothelial inducing cells was incubated with U0126, a specific p-ERK1/2 inhibitor. PDLSC from one person were randomly divided into four groups: control group, endothelial induced group, endothelial induced+DMSO group and endothelial induced+U0126 group. The protein expression of the p-EKR1/2 was analyzed by Western blotting at 0, 1, 3, 6 and 12 hours during endonthelial induction. The mRNA expressions of CD31, VE-cadherin, and VEGF were detected by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) after a 7-day induction. The proportion of CD31(+) to VE-cadherin(+) cells was identified by flow cytometry, and the ability of capillary-like tubes formation was detected by Matrigel assay after a 14-day induction. The measurement data were statistically analyzed. Phosphorylated ERK1/2 protein level in PDLSC was increased to 1.24±0.12 and 1.03±0.24 at 1 h and 3 h respectively, during the endothelial induction (P<0.01). The mRNA expressions of CD31 and VEGF in induced+U0126 group were decreased to 0.09±0.18 and 0.49±0.17, which were both significantly different with those in induced group (P<0.05). The proportion of CD31(+) to VE-cadherin(+) cells of induced+U0126 group were decreased to 5.22±0.85 and 3.56±0.87, which were both significantly different with those in induced group (P<0.05). In Matrigel assay, the branching points, tube number and tube length were decreased to 7.0±2.7, 33.5±6.4, and (15 951.0±758.1) pixels, which were all significantly different with those in induced group (P<0.05). The endothelial differentiation of PDLSC is positively regulated by ERK signaling pathway. Inhibition of ERK1/2 phosphorylation could suppress endothelial differentiation of PDLSC.

Revision ulnar collateral ligament reconstruction using a suspension button fixation technique.

PubMed

Lee, Gregory H; Limpisvasti, Orr; Park, Maxwell C; McGarry, Michelle H; Yocum, Lewis A; Lee, Thay Q

2010-03-01

Revision ulnar collateral ligament reconstruction remains a challenging problem. The objective of this study was to biomechanically evaluate an ulnar collateral ligament reconstruction technique using a suspension button fixation technique that can be used even in the case of ulnar cortical bone loss. An ulnar suspension fixation technique for ulnar collateral ligament reconstruction can restore elbow kinematics and demonstrate failure strength comparable to that of currently available techniques. Controlled laboratory study. Nine pairs of cadaveric elbows were dissected free of soft tissue and potted. After simulating ulnar cortical bone loss, ulnar collateral ligament reconstruction was performed in 1 elbow of each pair using palmaris longus autograft and a 30-mm RetroButton suspended from the far (lateralmost) ulnar cortex. A docking technique was used for humeral fixation of the graft. Elbow valgus angle was quantified using a Microscribe 3DLX digitizer at multiple elbow flexion angles. Valgus angle was measured with the ulnar collateral ligament intact, transected, and reconstructed. In addition, load-to-failure testing was performed in 1 elbow of each pair. Release of the ulnar collateral ligament caused a significant increase in valgus angle at each flexion angle tested (P < .002). Reconstructed elbows demonstrated no significant differences in valgus angle from the intact elbow at all flexion angles tested. Load-to-failure tests showed that reconstructed elbows had an ultimate torque (10.3 + or - 5.7 N x m) significantly less than intact elbows (26.4 + or - 10.6 N x m) (P = .001). Ulnar collateral ligament reconstruction using a suspension button fixation technique reliably restored elbow kinematics to the intact state. Load-to-failure testing demonstrated comparable fixation strength to several historic controls of primary reconstruction techniques despite the simulated ulnar cortical bone loss. Ulnar collateral ligament reconstruction using a suspension button fixation technique can be considered in the case of ulnar cortical bone loss in a primary or revision setting.

Ligament flow during drop-on-demand inkjet printing of bioink containing living cells

NASA Astrophysics Data System (ADS)

Zhang, Mengyun; Krishnamoorthy, Srikumar; Song, Hongtao; Zhang, Zhengyi; Xu, Changxue

2017-03-01

Organ printing utilizes tissue spheroids or filaments as building blocks to fabricate three-dimensional (3D) functional tissues and organs based on a layer-by-layer manufacturing mechanism. These fabricated tissues and organs are envisioned as alternatives to replace the damaged human tissues and organs, which is emerging as a promising solution to solve the organ donor shortage problem being faced all over the world. Inkjetting, one of the key technologies in organ printing, has been widely developed because of its moderate fabrication cost, good process controllability, and scale-up potentials. There are several key steps towards inkjet-based organ printing: generation of droplets from bioink, fabrication of 3D cellular structures, and post-printing tissue fusion and maturation. The droplet formation process is the first step, affecting the overall feasibility of the envisioned organ printing technology. This paper focuses on the ligament flow of the droplet formation process during inkjet printing of bioink containing living cells and its corresponding effect on post-printing cell viability and cell distribution. It is found that (1) two types of ligament flow are observed: at 30 V (Type I), the ligament flow has two different directions at the locations near the nozzle orifice and the forming droplet; at 60 V (Type II), the ligament flow directions are the same at both locations; (2) compared to Type II, fewer cells are ejected into the primary droplets in Type I, because some cells move back into the nozzle driven by the ligament flow in the positive z direction; and (3) cell viability in both Type I and Type II is around 90% without a significant difference. The resulting knowledge will benefit precise control of printing dynamics during inkjet printing of viscoelastic bioink for 3D biofabrication applications.

Action Mechanism of Fibroblast Growth Factor-2 (FGF-2) in the Promotion of Periodontal Regeneration in Beagle Dogs

PubMed Central

Nagayasu-Tanaka, Toshie; Anzai, Jun; Takaki, Shu; Shiraishi, Noriko; Terashima, Akio; Asano, Taiji; Nozaki, Takenori; Kitamura, Masahiro; Murakami, Shinya

2015-01-01

Fibroblast growth factor-2 (FGF-2) enhances the formation of new alveolar bone, cementum, and periodontal ligament (PDL) in periodontal defect models. However, the mechanism through which FGF-2 acts in periodontal regeneration in vivo has not been fully clarified yet. To reveal the action mechanism, the formation of regenerated tissue and gene expression at the early phase were analyzed in a beagle dog 3-wall periodontal defect model. FGF-2 (0.3%) or the vehicle (hydroxypropyl cellulose) only were topically applied to the defect in FGF-2 and control groups, respectively. Then, the amount of regenerated tissues and the number of proliferating cells at 3, 7, 14, and 28 days and the number of blood vessels at 7 days were quantitated histologically. Additionally, the expression of osteogenic genes in the regenerated tissue was evaluated by real-time PCR at 7 and 14 days. Compared with the control, cell proliferation around the existing bone and PDL, connective tissue formation on the root surface, and new bone formation in the defect at 7 days were significantly promoted by FGF-2. Additionally, the number of blood vessels at 7 days was increased by FGF-2 treatment. At 28 days, new cementum and PDL were extended by FGF-2. Moreover, FGF-2 increased the expression of bone morphogenetic protein 2 (BMP-2) and osteoblast differentiation markers (osterix, alkaline phosphatase, and osteocalcin) in the regenerated tissue. We revealed the facilitatory mechanisms of FGF-2 in periodontal regeneration in vivo. First, the proliferation of fibroblastic cells derived from bone marrow and PDL was accelerated and enhanced by FGF-2. Second, angiogenesis was enhanced by FGF-2 treatment. Finally, osteoblastic differentiation and bone formation, at least in part due to BMP-2 production, were rapidly induced by FGF-2. Therefore, these multifaceted effects of FGF-2 promote new tissue formation at the early regeneration phase, leading to enhanced formation of new bone, cementum, and PDL. PMID:26120833

A Comparison of Degradable Synthetic Polymer Fibers for Anterior Cruciate Ligament Reconstruction

PubMed Central

Tovar, Nick; Bourke, Sharon; Jaffe, Michael; Murthy, N. Sanjeeva; Kohn, Joachim; Gatt, Charles; Dunn, Michael G.

2009-01-01

We compared mechanical properties, degradation rates, and cellular compatibilities of two synthetic polymer fibers potentially useful as ACL reconstruction scaffolds: poly(desaminotyrosyl-tyrosine dodecyl dodecanedioate)(12,10), p(DTD DD) and poly(L-lactic acid), PLLA. The yield stress of ethylene oxide (ETO) sterilized wet fibers was 150 ± 22 MPa and 87 ± 12 MPa for p(DTD DD) and PLLA, respectively, with moduli of 1.7 ± 0.1 MPa and 4.4 ± 0.43 MPa. Strength and molecular weight retention were determined after incubation under physiological conditions at varying times. After 64 weeks strength decreased to 20 and 37% of the initial sterile fiber values and MW decreased to 41% and 36% of the initial values for p(DTD DD) and PLLA, respectively. ETO sterilization had no significant effect on mechanical properties. Differences in mechanical behavior may be due to the semicrystalline nature of PLLA and the small degree of crystallinity induced by mesogenic ordering in p(DTD DD) suggested by DSC analysis. Fibroblast growth was similar on 50-fiber scaffolds of both polymers through 16 days in vitro. These data suggest that p(DTD DD) fibers, with higher strength, lower stiffness, favorable degradation rate and cellular compatibility, may be a superior alternative to PLLA fibers for development of ACL reconstruction scaffolds. PMID:19623532

Cellular dysfunction in the diabetic fibroblast: impairment in migration, vascular endothelial growth factor production, and response to hypoxia.

PubMed

Lerman, Oren Z; Galiano, Robert D; Armour, Mary; Levine, Jamie P; Gurtner, Geoffrey C

2003-01-01

Although it is known that systemic diseases such as diabetes result in impaired wound healing, the mechanism for this impairment is not understood. Because fibroblasts are essential for wound repair, we compared the in vitro behavior of fibroblasts cultured from diabetic, leptin receptor-deficient (db/db) mice with wild-type fibroblasts from mice of the same genetic background in processes important during tissue repair. Adult diabetic mouse fibroblast migration exhibited a 75% reduction in migration compared to normal fibroblasts (P < 0.001) and was not significantly stimulated by hypoxia (1% O(2)), whereas wild-type fibroblast migration was up-regulated nearly twofold in hypoxic conditions (P < 0.05). Diabetic fibroblasts produced twice the amount of pro-matrix metalloproteinase-9 as normal fibroblasts, as measured by both gelatin zymography and enzyme-linked immunosorbent assay (P < 0.05). Adult diabetic fibroblasts exhibited a sevenfold impairment in vascular endothelial growth factor (VEGF) production (4.5 +/- 1.3 pg/ml versus 34.8 +/- 3.3 pg/ml, P < 0.001) compared to wild-type fibroblasts. Moreover, wild-type fibroblast production of VEGF increased threefold in response to hypoxia, whereas diabetic fibroblast production of VEGF was not up-regulated in hypoxic conditions (P < 0.001). To address the question whether these differences resulted from chronic hyperglycemia or absence of the leptin receptor, fibroblasts were harvested from newborn db/db mice before the onset of diabetes (4 to 5 weeks old). These fibroblasts showed no impairments in VEGF production under basal or hypoxic conditions, confirming that the results from db/db fibroblasts in mature mice resulted from the diabetic state and were not because of alterations in the leptin-leptin receptor axis. Markers of cellular viability including proliferation and senescence were not significantly different between diabetic and wild-type fibroblasts. We conclude that, in vitro, diabetic fibroblasts show selective impairments in discrete cellular processes critical for tissue repair including cellular migration, VEGF production, and the response to hypoxia. The VEGF abnormalities developed concurrently with the onset of hyperglycemia and were not seen in normoglycemic, leptin receptor-deficient db/db mice. These observations support a role for fibroblast dysfunction in the impaired wound healing observed in human diabetics, and also suggest a mechanism for the poor clinical outcomes that occur after ischemic injury in diabetic patients.

Cellular Dysfunction in the Diabetic Fibroblast

PubMed Central

Lerman, Oren Z.; Galiano, Robert D.; Armour, Mary; Levine, Jamie P.; Gurtner, Geoffrey C.

2003-01-01

Although it is known that systemic diseases such as diabetes result in impaired wound healing, the mechanism for this impairment is not understood. Because fibroblasts are essential for wound repair, we compared the in vitro behavior of fibroblasts cultured from diabetic, leptin receptor-deficient (db/db) mice with wild-type fibroblasts from mice of the same genetic background in processes important during tissue repair. Adult diabetic mouse fibroblast migration exhibited a 75% reduction in migration compared to normal fibroblasts (P < 0.001) and was not significantly stimulated by hypoxia (1% O2), whereas wild-type fibroblast migration was up-regulated nearly twofold in hypoxic conditions (P < 0.05). Diabetic fibroblasts produced twice the amount of pro-matrix metalloproteinase-9 as normal fibroblasts, as measured by both gelatin zymography and enzyme-linked immunosorbent assay (P < 0.05). Adult diabetic fibroblasts exhibited a sevenfold impairment in vascular endothelial growth factor (VEGF) production (4.5 ± 1.3 pg/ml versus 34.8 ± 3.3 pg/ml, P < 0.001) compared to wild-type fibroblasts. Moreover, wild-type fibroblast production of VEGF increased threefold in response to hypoxia, whereas diabetic fibroblast production of VEGF was not up-regulated in hypoxic conditions (P < 0.001). To address the question whether these differences resulted from chronic hyperglycemia or absence of the leptin receptor, fibroblasts were harvested from newborn db/db mice before the onset of diabetes (4 to 5 weeks old). These fibroblasts showed no impairments in VEGF production under basal or hypoxic conditions, confirming that the results from db/db fibroblasts in mature mice resulted from the diabetic state and were not because of alterations in the leptin-leptin receptor axis. Markers of cellular viability including proliferation and senescence were not significantly different between diabetic and wild-type fibroblasts. We conclude that, in vitro, diabetic fibroblasts show selective impairments in discrete cellular processes critical for tissue repair including cellular migration, VEGF production, and the response to hypoxia. The VEGF abnormalities developed concurrently with the onset of hyperglycemia and were not seen in normoglycemic, leptin receptor-deficient db/db mice. These observations support a role for fibroblast dysfunction in the impaired wound healing observed in human diabetics, and also suggest a mechanism for the poor clinical outcomes that occur after ischemic injury in diabetic patients. PMID:12507913

Anterolateral Ligament of the Knee Shows Variable Anatomy in Pediatric Specimens.

PubMed

Shea, Kevin G; Milewski, Matthew D; Cannamela, Peter C; Ganley, Theodore J; Fabricant, Peter D; Terhune, Elizabeth B; Styhl, Alexandra C; Anderson, Allen F; Polousky, John D

2017-06-01

Anterior cruciate ligament (ACL) reconstruction failure rates are highest in youth athletes. The role of the anterolateral ligament in rotational knee stability is of increasing interest, and several centers are exploring combined ACL and anterolateral ligament reconstruction for these young patients. Literature on the anterolateral ligament of the knee is sparse in regard to the pediatric population. A single study on specimens younger than age 5 years demonstrated the presence of the anterolateral ligament in only one of eight specimens; therefore, much about the prevalence and anatomy of the anterolateral ligament in pediatric specimens remains unknown. We sought to (1) investigate the presence or absence of the anterolateral ligament in prepubescent anatomic specimens; (2) describe the anatomic relationship of the anterolateral ligament to the lateral collateral ligament; and (3) describe the anatomic relationship between the anterolateral ligament and the physis. Fourteen skeletally immature knee specimens (median age, 8 years; range, 7-11 years) were dissected (12 male, two female specimens). The posterolateral structures were identified in all specimens, including the lateral collateral ligament and popliteus tendon. The presence or absence of the anterolateral ligament was documented in each specimen, along with origin, insertion, and dimensions, when applicable. The relationship of the anterolateral ligament origin to the lateral collateral ligament origin was recorded. The anterolateral ligament was identified in nine of 14 specimens. The tibial attachment point was consistently located in the same region on the proximal tibia, between the fibular head and Gerdy's tubercle; however, the femoral origin of the anterolateral ligament showed considerable variation with respect to the lateral collateral ligament origin. The median femoral origin of the anterolateral ligament was 10 mm (first interquartile 6 mm, third interquartile 13) distal to the distal femoral physis, whereas its median insertion was 9 mm (first interquartile 5 mm, third interquartile 11 mm) proximal to the proximal tibial physis. The frequency of the anterolateral ligament in pediatric specimens we observed was much lower than other studies on adult specimens; future studies might further investigate the prevalence, development, and functional role of the anterolateral ligament of the knee. This study expands our understanding of the anterolateral ligament and provides important anatomic information to surgeons considering anterolateral ligament reconstruction concomitantly with primary or revision ACL reconstruction in pediatric athletes.

Filamin A regulates the organization and remodeling of the pericellular collagen matrix.

PubMed

Mezawa, Masaru; Pinto, Vanessa I; Kazembe, Mwayi P; Lee, Wilson S; McCulloch, Christopher A

2016-10-01

Extracellular matrix remodeling by cell adhesion-related processes is critical for proliferation and tissue homeostasis, but how adhesions and the cytoskeleton interact to organize the pericellular matrix (PCM) is not understood. We examined the role of the actin-binding protein, filamin A (FLNa), in pericellular collagen remodeling. Compared with wild-type (WT), mice with fibroblast-specific deletion of FLNa exhibited higher density but reduced organization of collagen fibers after increased loading of the periodontal ligament for 2 wk. In cultured fibroblasts, FLNa knockdown (KD) did not affect collagen mRNA, but after 24 h of culture, FLNa WT cells exhibited ∼2-fold higher cell-surface collagen KD cells and 13-fold higher levels of activated β1 integrins. In FLNa WT cells, there was 3-fold more colocalization of talin with pericellular cleaved collagen than in FLNa KD cells. MMP-9 mRNA and protein expression were >2-fold higher in FLNa KD cells than in WT cells. Cathepsin B, which is necessary for intracellular collagen digestion, was >3-fold higher in FLNa WT cells than in KD cells. FLNa WT cells exhibited 2-fold more collagen phagocytosis than KD cells, which involved the FLNa actin-binding domain. Evidently, FLNa regulates PCM remodeling through its effects on degradation pathways that affect the abundance and organization of collagen.-Mezawa, M., Pinto, V. I., Kazembe, M. P., Lee, W. S., McCulloch, C. A. Filamin A regulates the organization and remodeling of the pericellular collagen matrix. © FASEB.

In vitro models for evaluation of periodontal wound healing/regeneration.

PubMed

Weinreb, Miron; Nemcovsky, Carlos E

2015-06-01

Periodontal wound healing and regeneration are highly complex processes, involving cells, matrices, molecules and genes that must be properly choreographed and orchestrated. As we attempt to understand and influence these clinical entities, we need experimental models to mimic the various aspects of human wound healing and regeneration. In vivo animal models that simulate clinical situations of humans can be costly and cumbersome. In vitro models have been devised to dissect wound healing/regeneration processes into discrete, analyzable steps. For soft tissue (e.g. gingival) healing, in vitro models range from simple culture of cells grown in monolayers and exposed to biological modulators or physical effectors and materials, to models in which cells are 'injured' by scraping and subsequently the 'wound' is filled with new or migrating cells, to three-dimensional models of epithelial-mesenchymal recombination or tissue explants. The cells employed are gingival keratinocytes, fibroblasts or endothelial cells, and their proliferation, migration, attachment, differentiation, survival, gene expression, matrix production or capillary formation are measured. Studies of periodontal regeneration also include periodontal ligament fibroblasts or progenitors, osteoblasts or osteoprogenitors, and cementoblasts. Regeneration models measure cellular proliferation, attachment and migration, as well as gene expression, transfer and differentiation into a mineralizing phenotype and biomineralization. Only by integrating data from models on all levels (i.e. a single cell to the whole organism) can various critical aspects of periodontal wound healing/regeneration be fully evaluated. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Re-evaluation of tumor-specific cytotoxicity of mitomycin C, bleomycin and peplomycin.

PubMed

Sasaki, Masahiro; Okamura, Masahiko; Ideo, Atsushi; Shimada, Jun; Suzuki, Fumika; Ishihara, Mariko; Kikuchi, Hirotaka; Kanda, Yumiko; Kunii, Shiro; Sakagami, Hiroshi

2006-01-01

Three antitumor antibiotics, mitomycin C, bleomycin sulfate and peplomycin sulfate, were compared for their tumor-specific cytotoxicity, using human oral squamous cell lines (HSC-2, HSC-3, HSC-4, Ca9-22 and NA), human promyelocytic leukemic cell line HL-60 and human normal oral cell types (gingival fibroblast HGF, pulp cell HPC and periodontal ligament fibroblast HPLF). Among these three compounds, mitomycin C showed the highest tumor-specificity, due to its higher cytotoxic activity against human oral tumor cell lines than bleomycin and peplomycin. However, there was considerable variation of drug sensitivity among the six tumor cell lines. Mitomycin C induced internucleosomal DNA fragmentation and caspase-3, -8 and -9 activation in HL-60 cells only after 24 h. On the other hand, mitomycin C induced no clear-cut DNA fragmentation in HCS-2 cells, although it activated caspase-3, -8 and -9 to a slightly higher extent. Western blot analysis demonstrated that mitomycin C did not induce any apparent change in the intracellular concentration of anti-apoptotic protein (Bcl-2) and pro-apoptotic proteins (Bax, Bad). Electron microscopy of mitomycin C-treated HL-60 cells showed intact mitochondria (as regards to integrity and size) and cell surface microvilli, without production of an apoptotic body or autophagosome, at an early stage after treatment. The present study suggests the incomplete induction of apoptosis or the induction of another type of cell death by mitomycin C treatment.

Recombinant human basic fibroblast growth factor (bFGF) stimulates periodontal regeneration in class II furcation defects created in beagle dogs.

PubMed

Murakami, S; Takayama, S; Kitamura, M; Shimabukuro, Y; Yanagi, K; Ikezawa, K; Saho, T; Nozaki, T; Okada, H

2003-02-01

Several growth factors (or cytokines) have been recently investigated for their use as potential therapeutics for periodontal tissue regeneration. The objective of this study was to evaluate periodontal tissue regeneration, including new bone and cementum formation, following topical application of recombinant basic fibroblast growth factor (bFGF, FGF-2) to furcation class II defects. Twelve furcation class II bone defects were surgically created in six beagle dogs, then recombinant bFGF (30 micro g/site) + gelatinous carrier was topically applied to the bony defects. Six weeks after application, periodontal regeneration was analyzed. In all sites where bFGF was applied, periodontal ligament formation with new cementum deposits and new bone formation was observed histomorphometrically, in amounts greater than in the control sites. Basic FGF-applied sites exhibited significant regeneration as represented by the new bone formation rate (NBR) (83.6 +/- 14.3%), new trabecular bone formation rate (NTBR) (44.1 +/- 9.5%), and new cementum formation rate (NCR) (97.0 +/- 7.5%). In contrast, in the carrier-only sites, the NBR, NTBR, and NCR were 35.4 +/- 8.9%, 16.6 +/- 6.2%, and 37.2 +/- 15.1%, respectively. Moreover, no instances of epithelial down growth, ankylosis, or root resorption were observed in the bFGF-applied sites examined. The present results indicate that topical application of bFGF can enhance considerable periodontal regeneration in artificially created furcation class II bone defects of beagle dogs.

Cranial cruciate stability in the rottweiler and racing greyhound: an in vitro study.

PubMed

Wingfield, C; Amis, A A; Stead, A C; Law, H T

2000-05-01

An in vitro biomechanical study of cadaver stifles from rottweilers and racing greyhounds was undertaken to evaluate the contribution of the cranial cruciate ligament to stifle joint stability. This was performed at differing stifle joint angles, first with the joint capsules and ligaments intact and then with all structures removed except for the cranial cruciate ligament. Craniocaudal laxity increased in both breeds as stifle flexion increased. The rottweiler stifle showed greater craniocaudal joint laxity than the racing greyhound at all joint angles between 150 degrees and 110 degrees, but the actual increases in joint laxity between these joint angles were similar for both breeds. Tibial rotation during craniocaudal loading of the stifle increased craniocaudal laxity in both breeds during joint flexion. The relative contribution of the cranial cruciate ligament to cranial stability of the stifle joint increased as the joint flexed and was similar in both breeds.

Sheet, ligament and droplet formation in swirling primary atomization

NASA Astrophysics Data System (ADS)

Shao, Changxiao; Luo, Kun; Chai, Min; Fan, Jianren

2018-04-01

We report direct numerical simulations of swirling liquid atomization to understand the physical mechanism underlying the sheet breakup of a non-turbulent liquid swirling jet which lacks in-depth investigation. The volume-of-fluid (VOF) method coupled with adapted mesh refinement (AMR) technique in GERRIS code is employed in the present simulation. The mechanisms of sheet, ligament and droplet formation are investigated. It is observed that the olive-shape sheet structure is similar to the experimental result qualitatively. The numerical results show that surface tension, pressure difference and swirling effect contribute to the contraction and extension of liquid sheet. The ligament formation is partially at the sheet rim or attributed to the extension of liquid hole. Especially, the movement of hairpin vortex exerts by an anti-radial direction force to the sheet surface and leads to the sheet thinness. In addition, droplet formation is attributed to breakup of ligament and central sheet.

Anterolateral ligament anatomy: a comparative anatomical study.

PubMed

Ingham, Sheila Jean McNeill; de Carvalho, Rogerio Teixeira; Martins, Cesar A Q; Lertwanich, Pisit; Abdalla, Rene Jorge; Smolinski, Patrick; Lovejoy, C Owen; Fu, Freddie H

2017-04-01

Some anatomical studies have indicated that the anterolateral ligament (ALL) of the knee is distinct ligamentous structure in humans. The purpose of this study is to compare the lateral anatomy of the knee among human and various animal specimens. Fifty-eight fresh-frozen knee specimens, from 24 different animal species, were used for this anatomical study. The same researchers dissected all the specimens in this study, and dissections were performed in a careful and standardized manner. An ALL was not found in any of the 58 knees dissected. Another interesting finding in this study is that some primate species (the prosimians: the red and black and white lemurs) have two LCLs. The clinical relevance of this study is the lack of isolation of the ALL as a unique structure in animal species. Therefore, precaution is recommended before assessing the need for surgery to reconstruct the ALL as a singular ligament.

Recent Developments in the Treatment of Ankle and Subtalar Instability

PubMed Central

Sugimoto, Kazuya

2017-01-01

It was nearly a centenary ago that severe ankle sprain was recognized as an injury of the ankle ligament(s). With the recent technological advances and tools in imaging and surgical procedures, the management of ankle sprains - including subtalar injuries - has drastically improved. The repair or reconstruction of ankle ligaments is getting more anatomical and less invasive than previously. More specifically, ligamentous reconstruction with tendon graft has been the gold standard in the management of severely damaged ligament, however, it does not reproduce the original ultrastructure of the ankle ligaments. The anatomical ligament structure of a ligament comprises a ligament with enthesis at both ends and the structure should also exhibit proprioceptive function. To date, it remains impossible to reconstruct a functionally intact and anatomical ligament. Cooperation of the regenerative medicine and surgical technology in expected to improve reconstructions of the ankle ligament, however, we need more time to develop a technology in reproducing the ideal ligament complex. PMID:28979582

A comparative study of skin cell activities in collagen and fibrin constructs.

PubMed

Law, Jia Xian; Musa, Faiza; Ruszymah, Bt Hj Idrus; El Haj, Alicia J; Yang, Ying

2016-09-01

Collagen and fibrin are widely used in tissue engineering due to their excellent biocompatibility and bioactivities that support in vivo tissue formation. These two hydrogels naturally present in different wound healing stages with different regulatory effects on cells, and both of them are mechanically weak in the reconstructed hydrogels. We conducted a comparative study by the growth of rat dermal fibroblasts or dermal fibroblasts and epidermal keratinocytes together in collagen and fibrin constructs respectively with and without the reinforcement of electrospun poly(lactic acid) nanofiber mesh. Cell proliferation, gel contraction and elastic modulus of the constructs were measured on the same gels at multiple time points during the 22 day culturing period using multiple non-destructive techniques. The results demonstrated considerably different cellular activities within the two types of constructs. Co-culturing keratinocytes with fibroblasts in the collagen constructs reduced the fibroblast proliferation, collagen contraction and mechanical strength at late culture point regardless of the presence of nanofibers. Co-culturing keratinocytes with fibroblasts in the fibrin constructs promoted fibroblast proliferation but exerted no influence on fibrin contraction and mechanical strength. The presence of nanofibers in the collagen and fibrin constructs played a favorable role on the fibroblast proliferation when keratinocytes were absent. Thus, this study exhibited new evidence of the strong cross-talk between keratinocytes and fibroblasts, which can be used to control fibroblast proliferation and construct contraction. This cross-talk activity is extracellular matrix-dependent in terms of the fibrous network morphology, density and strength. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Artificial Ligaments: Promise or Panacea?

ERIC Educational Resources Information Center

Lubell, Adele

1987-01-01

The Food and Drug Administration has approved a prosthetic ligament for limited use in persons with damaged anterior cruciate ligaments (ACL). This article addresses ligament repair, ACL tears, current treatment, development of the Gore-Tex artificial ligament, other artificial ligaments in process, and arguments for and against their use.…

Different fibroblast subpopulations of the eye: a therapeutic target to prevent postoperative fibrosis in glaucoma therapy.

PubMed

Stahnke, Thomas; Löbler, Marian; Kastner, Christian; Stachs, Oliver; Wree, Andreas; Sternberg, Katrin; Schmitz, Klaus-Peter; Guthoff, Rudolf

2012-07-01

The aim of this study is the characterization of fibroblasts mainly responsible for fibrosis processes associated with trabeculectomy or microstent implantation for glaucoma therapy. Therefore we isolated human primary fibroblasts from choroidea, sclera, Tenon capsule, and orbital fat tissues. These fibroblast subpopulations were analysed in vitro for expression of the extracellular matrix components which are responsible for postoperative scarring in glaucoma therapy. For scarring the proteins of the collagen family are predominant and so we focused on the expression of collagen I, collagen III and collagen VI in every fibroblast subpopulation. Also, the extracellular matrix protein fibronectin which crosslinks collagen fibres or other extracellular matrix components and cell surfaces, was analyzed. Collagen I, III and VI were prominent in every fibroblast subpopulation. The highest amounts of collagen III were found in hCF and hOF, whereas the signal in hSF and hTF was negligible. Additionally, there is a link between scarring processes and proliferating potential of fibroblasts, in case of microstent implantation triggered through the infiltration of inflammatory cells. Thus we analyzed fibroblast subpopulations for the presence of TGF-β1 which is one of the most important cytokines involved in proliferation processes. TGF-β1 was prominent in all fibroblast subpopulations with lowest expression in hCF cultures. To prevent postoperative fibroblast proliferation we analyzed in vitro the proliferation-inhibitors paclitaxel and mitomycin C which are potential candidates in drug eluting drainage systems on ocular fibroblast subpopulations. These inhibitors arrest fibroblast proliferation and viability, being, however, not very specific and have a cytotoxic potential also on healthy tissues surrounding the microstent outflow area. Significant differences in protein synthesis of fibroblasts subpopulations which could be specific targets for inhibition may help to find out fibroblast specific inhibitors to prevent postoperative scarring and could prevent patients from secondary surgery after microstent implantation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hip joint biomechanics in those with and without post-traumatic knee osteoarthritis after anterior cruciate ligament injury.

PubMed

Wellsandt, E; Zeni, J A; Axe, M J; Snyder-Mackler, L

2017-12-01

Anterior cruciate ligament injury results in altered kinematics and kinetics in the knee and hip joints that persist despite surgical reconstruction and rehabilitation. Abnormal movement patterns and a history of osteoarthritis are risk factors for articular cartilage degeneration in additional joints. The purpose of this study was to determine if hip joint biomechanics early after anterior cruciate ligament injury and reconstruction differ between patients with and without post-traumatic knee osteoarthritis 5years after reconstruction. The study's rationale was that individuals who develop knee osteoarthritis after anterior cruciate ligament injury may also demonstrate large alterations in hip joint biomechanics. Nineteen athletes with anterior cruciate ligament injury completed standard gait analysis before (baseline) and after (post-training) extended pre-operative rehabilitation and at 6months, 1year, and 2years after reconstruction. Weightbearing knee radiographs were completed 5years after reconstruction to identify medial compartment osteoarthritis. Five of 19 patients had knee osteoarthritis at 5years after anterior cruciate ligament reconstruction. Patients with knee osteoarthritis at 5years walked with smaller sagittal plane hip angles (P: 0.043) and lower sagittal (P: 0.021) and frontal plane (P: 0.042) external hip moments in the injured limb before and after reconstruction compared to those without knee osteoarthritis. The current findings suggest hip joint biomechanics may be altered in patients who develop post-traumatic knee osteoarthritis. Further study is needed to confirm whether the risk of non-traumatic hip pathology is increased after anterior cruciate ligament injury and if hip joint biomechanics influence its development. Copyright © 2017 Elsevier Ltd. All rights reserved.

Results of lateral ankle ligament repair surgery in one hundred and nineteen patients: do surgical method and arthroscopy timing matter?

PubMed

Araoye, Ibukunoluwa; De Cesar Netto, Cesar; Cone, Brent; Hudson, Parke; Sahranavard, Bahman; Shah, Ashish

2017-11-01

Ankle sprains are the most common athletic injury. One of five chronic lateral ankle instability patients will require surgery, making operative outcomes crucial. The purpose of this study is to determine if operative method influences failure and complication rates in chronic lateral ankle ligament repair surgery. We retrospectively reviewed 119 cases (118 patients) of lateral ankle ligament surgery between 2006 and 2016. Patient charts and operative reports were examined for demographics, use and timing of ankle arthroscopy, ligament fixation method, type of surgical incision, presence of calcaneofibular ligament repair, and operative technique. Impact of operative methods on failure (one-year minimum follow-up) and complication outcomes was explored using Chi-square test of independence (or Fisher's exact test). Statistical significance was set at p less than .05. Mean age at surgery was 40 (range, 18-73) years. Mean follow-up was 51 (range, 12-260) weeks. Failure rate was 8.4% (10/89 cases) while complication rate was 17.6% (21/119). Failure rate did not differ significantly between any data subgroups (p > .05). Single stage arthroscopy was associated with a significantly lower complication rate (11%, 4/37) than double-stage arthroscopy (47%, 9/19) (p < .01) as was suture anchor ligament fixation (9%, 6/67) compared to direct suture ligament fixation (29%, 15/52) (p < .01). Failure rate was not impacted by any of the studied variables. Use of suture anchors and concurrent ankle arthroscopy may be favourable options to achieve fewer complications in chronic lateral ankle instability repair surgery.

Acute inversion injury of the ankle: magnetic resonance imaging and clinical outcomes.

PubMed

Tochigi, Y; Yoshinaga, K; Wada, Y; Moriya, H

1998-11-01

This study was undertaken to compare the clinical and magnetic resonance imaging results of 24 patients who had sustained ligament injuries after acute inversion injury of the ankle. On magnetic resonance imaging, the following lesions were detected: anterior talofibular ligament tear in 23 patients, calcaneofibular ligament lesion in 15, posterior talofibular ligament lesion in 11, interosseous talocalcaneal ligament lesion in 13, cervical ligament lesion in 12, and deltoid ligament lesion in 8. Compared with the clinical outcome at the follow-up study, there was a statistically significant relationship between interosseous talocalcaneal ligament lesion and each of giving way, pain, and limitation of ankle motion; between cervical ligament lesion and both giving way and pain; and between deltoid ligament lesion and giving way (P < 0.05).

Isolation and characterization of multipotent human periodontal ligament stem cells.

PubMed

Gay, I C; Chen, S; MacDougall, M

2007-08-01

Periodontal ligament (PDL) repair is thought to involve mesenchymal progenitor cells capable of forming fibroblasts, osteoblasts and cementoblasts. However, full characterization of PDL stem cell (SC) populations has not been achieved. To isolate and characterize PDLSC and assess their capability to differentiate into bone, cartilage and adipose tissue. Human PDL cells were stained for STRO-1, FACS sorted and expanded in culture. Human bone marrow SC (BMSC) served as a positive control. PDLSC and BMSC were cultured using standard conditions conducive for osteogenic, chondrogenic and adipogenic differentiation. Osteogenic induction was assayed using alizarine red S staining and expression of alkaline phosphatase (ALP) and bone sialoprotein (BSP). Adipogenic induction was assayed using Oil Red O staining and the expression of PPAR gamma 2 (early) and LPL (late) adipogenic markers. Chondrogenic induction was assayed by collagen type II expression and toluidine blue staining. Human PDL tissue contains about 27% STRO-1 positive cells with 3% strongly positive. In osteogenic cultures ALP was observed by day-7 in BMSC and day-14 in PDLSC. BSP expression was detectable by day-7; with more intense staining in PDLSC cultures. In adipogenic cultures both cell populations showed positive Oil Red O staining by day-25 with PPAR gamma 2 and LPL expression. By day-21, both BMSC and PDLSC chondrogenic induced cultures expressed collagen type II and glycosaminoglycans. The PDL contains SC that have the potential to differentiate into osteoblasts, chondrocytes and adipocytes, comparable with previously characterized BMSC. This adult PDLSC population can be utilized for potential therapeutic procedures related to PDL regeneration.

Immunomodulatory properties of human periodontal ligament stem cells.

PubMed

Wada, Naohisa; Menicanin, Danijela; Shi, Songtao; Bartold, P Mark; Gronthos, Stan

2009-06-01

Tissue engineering utilizing periodontal ligament stem cells (PDLSCs) has recently been proposed for the development of new periodontal regenerative therapies. Although the use of autologous PDLSC transplantation eliminates the potential of a significant host immune response against the donor cells, it is often difficult to generate enough PDLSCs from one donor source due to the variation of stem cell potential between donors and disease state of each patient. In this study, we examined the immunomodulatory properties of PDLSCs as candidates for new allogeneic stem cell-based therapies. Human PDLSCs displayed cell surface marker characteristics and differentiation potential similar to bone marrow stromal stem cells (BMSSCs) and dental pulp stem cells (DPSCs). PDLSCs, BMSSCs, and DPSCs inhibited peripheral blood mononuclear cell (PBMNC) proliferation stimulated with mitogen or in an allogeneic mixed lymphocyte reaction (MLR). Interestingly, gingival fibroblasts (GFs) also suppressed allogeneic PBMNC proliferation under both assay conditions. PDLSCs, BMSSCs, DPSCs, and GFs exhibited non-cell contact dependent suppression of PBMNC proliferation in co-cultures using transwells. Furthermore, conditioned media (CM) derived from each cell type pretreated with IFN-gamma partially suppressed PBMNC proliferation when compared to CMs without IFN-gamma stimulation. In all of these mesenchymal cell types cultured with activated PBMNCs, the expression of TGF-beta1, hepatocyte growth factor (HGF) and indoleamine 2, 3-dioxygenase (IDO) was upregulated while IDO expression was upregulated following stimulation with IFN-gamma. These results suggest that PDLSCs, BMSSCs, DPSCs, and GFs possess immunosuppressive properties mediated, in part, by soluble factors, produced by activated PBMNCs. J. Cell. Physiol. 219: 667-676, 2009. (c) 2009 Wiley-Liss, Inc.

INFLUENCE OF DIFFERENT LEVELS OF SPORTS ACTIVITIES ON THE QUALITY OF LIFE AFTER THE RECONSTRUCTION OF ANTERIOR CRUCIATE LIGAMENT.

PubMed

Ninković, Srđan; Avramov, Snežana; Harhaji, Vladimir; Obradović, Mirko; Vranješ, Miodrag; Milankov, Miroslav

2015-01-01

The goal of this study was to examine the nature and presence of influence of different levels of sports activity on the life quality of the patients a year after the reconstruction of anterior cruciate ligament. The study included 185 patients operated at the Department of Orthopedic Surgery and Traumatology of the Clinical Centre of Vojvodina, who were followed for twelve months. Data were collected using the modified Knee Injury and Osteoarthritis Outcome Score questionnaire which included the Lysholm scale. This study included 146 male and 39 female subjects. The reconstruction of anterior cruciate ligament was equally successful in both gender groups. In relation to different types of sports activity, there were no differences in the overall life quality measured by the questionnaire and its subscales, regardless of the level (professional or recreational). However, regarding the level of sports activities, there were differences among the subjects engaged in sports activities at the national level as compared with those going in for sports activities at the recreational level, and particularly in comparison with physically inactive population. A significant correlation was not found by examining the aforementioned relationship between sports activities. This study has shown that the overall life quality a year after the reconstruction of the anterior cruciate ligament does not differ in relation to either the gender of the subjects or the type of sports activity, while the level of sports activity does have some influence on the quality of life. Professional athletes have proved to train significantly more intensively after this reconstruction than those going in for sports recreationally.

Quantitative Mapping of Matrix Content and Distribution across the Ligament-to-Bone Insertion

PubMed Central

Spalazzi, Jeffrey P.; Boskey, Adele L.; Pleshko, Nancy; Lu, Helen H.

2013-01-01

The interface between bone and connective tissues such as the Anterior Cruciate Ligament (ACL) constitutes a complex transition traversing multiple tissue regions, including non-calcified and calcified fibrocartilage, which integrates and enables load transfer between otherwise structurally and functionally distinct tissue types. The objective of this study was to investigate region-dependent changes in collagen, proteoglycan and mineral distribution, as well as collagen orientation, across the ligament-to-bone insertion site using Fourier transform infrared spectroscopic imaging (FTIR-I). Insertion site-related differences in matrix content were also evaluated by comparing tibial and femoral entheses. Both region- and site-related changes were observed. Collagen content was higher in the ligament and bone regions, while decreasing across the fibrocartilage interface. Moreover, interfacial collagen fibrils were aligned parallel to the ligament-bone interface near the ligament region, assuming a more random orientation through the bulk of the interface. Proteoglycan content was uniform on average across the insertion, while its distribution was relatively less variable at the tibial compared to the femoral insertion. Mineral was only detected in the calcified interface region, and its content increased exponentially across the mineralized fibrocartilage region toward bone. In addition to new insights into matrix composition and organization across the complex multi-tissue junction, findings from this study provide critical benchmarks for the regeneration of soft tissue-to-bone interfaces and integrative soft tissue repair. PMID:24019964

Age estimation using the radiographic visibility of the periodontal ligament in lower third molars in a Portuguese population.

PubMed

Sequeira, Catarina-Dourado; Teixeira, Alexandra; Caldas, Inês-Morais; Afonso, Américo; Pérez-Mongiovi, Daniel

2014-12-01

The mineralization of third molars has been used repeatedly as a method of forensic age estimation. However, this procedure is of little use beyond age 18, especially to determinate if an individual is older than 21 years of age; thus, the development of new approaches is essential. The visibility of the periodontal ligament has been suggested for this purpose. The aim of this work was to determine the usefulness of this methodology in a Portuguese population. Periodontal ligament visibility was assessed in the lower third molars, using a sample of 487 orthopantomograms, 228 of which belonging to females and 259 to males, from a Portuguese population aged 17 to 31 years. A classification of four stages based on the visual phenomenon of disappearance of the periodontal ligament of fully mineralized third molars was used. For each stage, median, variance, minimal and maximal age were assessed. The relationship between age and stage of periodontal ligament had a statistical significance for both sexes. In this population, stage 3 can be used to state that a male person is over 21 years-old; for females, another marker should be used. This technique can be useful for determining age over 21, particularly in males. Differences between studies are evident, suggesting that specific population standards should be used when applying this technique. Key words:Forensic sciences, forensic odontology, age estimation, third molar, periodontal ligament.

Evaluation of the resolving potency of a novel reconstruction filter on periodontal ligament space with dental cone-beam CT: a quantitative phantom study

NASA Astrophysics Data System (ADS)

Houno, Yuuki; Hishikawa, Toshimitsu; Gotoh, Ken-ichi; Naitoh, Munetaka; Ariji, Eiichiro; Kodera, Yoshie

2014-03-01

Diagnosis of the alveolar bone condition is important for the treatment planning of periodontal disease. Especially the determination of periodontal ligament space is the most important remark because it represents the periodontal tissue support for tooth retention. However, owing to the image blur of the current cone-beam CT (CBCT) imaging technique, the periodontal ligament space is difficult to visualize. In this study, we developed an original periodontal ligament phantom (PLP) and evaluated the image quality of simulated periodontal ligament space using a novel reconstruction filter for CBCT that emphasized high frequency component. PLP was composed from two resin blocks of different materials, the bone equivalent block and the dentine equivalent block. They were assembled to make continuously changing space from 0.0 to 1.0 millimeter that mimics periodontal ligament space. PLP was placed in water and the image was obtained by using Alphard-3030 dental cone-beam CT (Asahi Roentgen Industry Co., Ltd.). Then we reconstructed the projection data with a novel reconstruction filter. The axial images were compared with conventional reconstructed images. In novel filter reconstruction images, 0.4 millimeter of the space width was steadily detected by calculation of pixel value, on the other hand 0.6 millimeter was in conventional images. With our method, the resolving potency of conebeam CT images was improved.

Wear Behavior of an Unstable Knee: Stabilization via Implant Design?

PubMed Central

Reinders, Jörn; Kretzer, Jan Philippe

2014-01-01

Background. Wear-related failures and instabilities are frequent failure mechanisms of total knee replacements. High-conforming designs may provide additional stability for the joint. This study analyzes the effects of a ligamentous insufficiency on the stability and the wear behavior of a high-conforming knee design. Methods. Two simulator wear tests were performed on a high-conforming total knee replacement design. In the first, a ligamentous-stable knee replacement with a sacrificed anterior cruciate ligament was simulated. In the second, a ligamentous-unstable knee with additionally insufficient posterior cruciate ligament and medial collateral ligament was simulated. Wear was determined gravimetrically and wear particles were analyzed. Implant kinematics was recorded during simulation. Results. Significantly higher wear rates (P ≤ 0.001) were observed for the unstable knee (14.58 ± 0.56 mg/106 cycles) compared to the stable knee (7.97 ± 0.87 mg/106 cycles). A higher number of wear particles with only small differences in wear particle characteristics were observed. Under unstable knee conditions, kinematics increased significantly for translations and rotations (P ≤ 0.01). This increase was mainly attributed to higher tibial posterior translation and internal rotations. Conclusion. Higher kinematics under unstable test conditions is a result of insufficient stabilization via implant design. Due to the higher kinematics, increased wear was observed in this study. PMID:25276820

Topographical relations between the posterior cricothyroid ligament and the inferior laryngeal nerve.

PubMed

Reidenbach, M M

1995-01-01

The posterior cricothyroid ligament and its topographic relation to the inferior laryngeal nerve were studied in 54 human adult male and female larynges. Fourteen specimens were impregnated with curable polymers and cut into 600-800 microns sections along different planes. Forty formalin-fixed hemi-larynges were dissected and various measurements were made. The posterior cricothyroid ligament provides a dorsal strengthening for the joint capsule of the cricothyroid joint. Its fibers spread in a fan-like manner from a small area of origin at the cricoid cartilage to a more extended area of attachment at the inferior thyroid cornu. The ligament consists of one (7.5%) to four (12.5%), in most cases of three (45.0%) or two (35.0%), individual parts oriented from mediocranial to latero-caudal. The inferior laryngeal nerve courses immediately dorsal to the ligament. In 60% it is covered by fibers of the posterior cricoarytenoid muscle, in the remaining 40% it is not. In this latter topographic situation there is almost no soft tissue interposed between the nerve and the hypopharynx. Therefore, the nerve may be exposed to pressure forces exerted from dorsally. It may be pushed against the unyielding posterior cricothyroid ligament and suffer functional or structural impairment. Probably, this mechanism may explain some of the laryngeal nerve lesions described in the literature after insertion of gastric tubes.

Quantitative investigation of ligament strains during physical tests for sacroiliac joint pain using finite element analysis.

PubMed

Kim, Yoon Hyuk; Yao, Zhidong; Kim, Kyungsoo; Park, Won Man

2014-06-01

It may be assumed that the stability is affected when some ligaments are injured or loosened, and this joint instability causes sacroiliac joint pain. Several physical examinations have been used to diagnose sacroiliac pain and to isolate the source of the pain. However, more quantitative and objective information may be necessary to identify unstable or injured ligaments during these tests due to the lack of understanding of the quantitative relationship between the physical tests and the biomechanical parameters that may be related to pains in the sacroiliac joint and the surrounding ligaments. In this study, a three-dimensional finite element model of the sacroiliac joint was developed and the biomechanical conditions for six typical physical tests such as the compression test, distraction test, sacral apex pressure test, thigh thrust test, Patrick's test, and Gaenslen's test were modelled. The sacroiliac joint contact pressure and ligament strain were investigated for each test. The values of contact pressure and the combination of most highly strained ligaments differed markedly among the tests. Therefore, these findings in combination with the physical tests would be helpful to identify the pain source and to understand the pain mechanism. Moreover, the technology provided in this study might be a useful tool to evaluate the physical tests, to improve the present test protocols, or to develop a new physical test protocol. Copyright © 2013 Elsevier Ltd. All rights reserved.

MRI of injury to the lateral collateral ligamentous complex of the ankle.

PubMed

Cardone, B W; Erickson, S J; Den Hartog, B D; Carrera, G F

1993-01-01

We retrospectively evaluated the lateral collateral ligamentous complex of 43 patients who had complained of ankle pain following ankle sprain. The MR signs of ligamentous abnormality included discontinuity or absence, increased signal within the ligament, and ligamentous irregularity or waviness with normal thickness and signal intensity. Using these criteria, 30 anterior talofibular, 20 calcaneofibular, and no posterior talofibular ligament injuries were diagnosed. Compared with surgery (nine patients), MRI demonstrated six of seven anterior talofibular ligament injuries and six of six calcaneofibular ligament injuries. Magnetic resonance showed ligamentous abnormalities in 12 of 23 cases with normal stress radiography. Magnetic resonance imaging provides useful information for the evaluation of patients presenting with chronic pain after ankle sprain.

Refinements in modeling the passive properties of laryngeal soft tissue.

PubMed

Hunter, Eric J; Titze, Ingo R

2007-07-01

The nonlinear viscoelastic passive properties of three canine intrinsic laryngeal muscles, the lateral cricoarytenoid (LCA), the posterior cricoarytenoid (PCA), and the interarytenoid (IA), were fit to the parameters of a modified Kelvin model. These properties were compared with those of the thyroarytenoid (TA) and cricothyroid (CT) muscles, as well as previously unpublished viscoelastic characteristics of the human vocal ligament. Passive parameters of the modified Kelvin model were summarized for the vocal ligament, mucosa, and all five laryngeal muscles. Results suggest that the LCA, PCA, and IA muscles are functionally different from the TA and CT muscles in their load-bearing capacity. Furthermore, the LCA, PCA, and IA have a much larger stress-strain hysteresis effect than has been previously reported for the TA and CT or the vocal ligament. The variation in this effect suggests that the connective tissue within the TA and CT muscles is somehow similar to the vocal ligament but different from the LCA, PCA, or IA muscles. Further demonstrating the potential significance of grouping tissues in the laryngeal system by functional groups in the laryngeal system was the unique finding that, over their working elongation range, the LCA and PCA were nearly as exponentially stiff as the vocal ligament. This paper was written in conjunction with an online technical report (http://www.ncvs.org/ncvs/library/tech) in which comprehensive muscle data and sensitivity analysis, as well as downloadable data files and computer scripts, are made available.

Acromioclavicular joint reconstruction using the LockDown synthetic implant: a study with cadavers.

PubMed

Taranu, R; Rushton, P R P; Serrano-Pedraza, I; Holder, L; Wallace, W A; Candal-Couto, J J

2015-12-01

Dislocation of the acromioclavicular joint is a relatively common injury and a number of surgical interventions have been described for its treatment. Recently, a synthetic ligament device has become available and been successfully used, however, like other non-native solutions, a compromise must be reached when choosing non-anatomical locations for their placement. This cadaveric study aimed to assess the effect of different clavicular anchorage points for the Lockdown device on the reduction of acromioclavicular joint dislocations, and suggest an optimal location. We also assessed whether further stability is provided using a coracoacromial ligament transfer (a modified Neviaser technique). The acromioclavicular joint was exposed on seven fresh-frozen cadaveric shoulders. The joint was reconstructed using the Lockdown implant using four different clavicular anchorage points and reduction was measured. The coracoacromial ligament was then transferred to the lateral end of the clavicle, and the joint re-assessed. If the Lockdown ligament was secured at the level of the conoid tubercle, the acromioclavicular joint could be reduced anatomically in all cases. If placed medial or 2 cm lateral, the joint was irreducible. If the Lockdown was placed 1 cm lateral to the conoid tubercle, the joint could be reduced with difficulty in four cases. Correct placement of the Lockdown device is crucial to allow anatomical joint reduction. Even when the Lockdown was placed over the conoid tubercle, anterior clavicle displacement remained but this could be controlled using a coracoacromial ligament transfer. ©2015 The British Editorial Society of Bone & Joint Surgery.

Modification of Distal Tibiofibular Relationship After a Mild Syndesmotic Injury.

PubMed

Nault, Marie-Lyne; Gascon, Laurence; Hébert-Davies, Jonah; Leduc, Stéphane; Laflamme, G Yves; Kramer, Dennis

2017-04-01

The hypothesis of this study is that a sprain or tear of 1 or more of the 3 syndesmotic ligaments will result in a significant change in the osseous anatomy relationship when comparing injured to uninjured syndesmosis. Our secondary objective was to determine whether injuries to the syndesmosis as diagnosed on magnetic resonance imaging (MRI) could be found using static imaging. This is a descriptive radiological study of ankle MRI reports over a 12-year period, from 2 different institutions, and divided in two groups: normal and injured syndesmotic ligaments. A series of 6 lengths and 2 angles were measured on MRI axial views that describe the rotation, lateral, and anteroposterior translational relation between the distal tibia and fibula. Parameters from injured and uninjured ankles were compared using Student's t-test. Fifty uninjured syndesmosis were compared to 64 injured syndesmoses. The majority of syndesmosis injuries concerned either an anterior inferior tibiofibular ligament sprain or tear. There was a significant difference in the anatomic position of the tibia and the fibula between injured and uninjured syndesmosis. The anterior inferior tibiofibular ligament is the most commonly injured ligament in the syndesmosis in sports injury and results in subtle variations in the syndesmotic anatomy, which plain radiographs cannot assess. Because of the previously validated computed tomography scan measurement, this study demonstrates a potential to identify syndesmotic injury on other more accessible imaging modalities, such as computed tomography scan, by using a well-defined measurement system. Diagnostic, Level III : Retrospective, Radiologic Study.

Anterior Cruciate Ligament Strain In Vivo: A Systematic Review.

PubMed

Luque-Seron, Juan Antonio; Medina-Porqueres, Ivan

2016-09-01

Distinct exercises have been proposed for knee rehabilitation after anterior cruciate ligament (ACL) reconstruction. There is a need to understand ACL strain behavior during different rehabilitation exercises to protect the graft from excessive strain that could interfere with its healing process. To critically review studies that directly measured normal ACL strain in vivo during different movements, conditions, or exercises to gain insight into which of them may produce more strain on the ligament or the ligament graft in the case of reconstructed knees. A literature search of PubMed, CINAHL, SPORTDiscus, and PEDro databases was conducted. Keywords included anterior cruciate ligament, strain, stress, deformation, transducer, rehabilitation, rehabilitation exercise, physical therapy, and physiotherapy. Inclusion criteria were (1) peer-reviewed studies published in English or Spanish, (2) research conducted on adult human subjects with normal ACLs and healthy knees, and (3) ACL strain directly measured during different movements, conditions, or exercises by using a transducer. Systematic review. Level 4. Specific data were abstracted from the selected studies, including isometric quadriceps and hamstrings activity, active and passive flexion-extension of the knee, closed kinetic chain exercises, and application of joint compressive load. A total of 10 studies met all criteria and were included in the final analysis. The strain values produced by closed kinetic chain and open kinetic chain exercises were similar. However, closed kinetic chain exercises appear to attenuate the strain increase that occurs in open kinetic chain exercises when increasing resistance. These data may be relevant to develop rehabilitation exercises or programs that do not endanger the healing ACL graft and to provide a basis for future clinical trials. © 2016 The Author(s).

Biological Differences between Hanwoo longissimus dorsi and semimembranosus Muscles in Collagen Synthesis of Fibroblasts.

PubMed

Subramaniyan, Sivakumar Allur; Hwang, Inho

2017-01-01

Variations in physical toughness between muscles and animals are a function of growth rate and extend of collagen type I and III. The current study was designed to investigate the ability of growth rate, collagen concentration, collagen synthesizing and degrading genes on two different fibroblast cells derived from Hanwoo m. longissimus dorsi (LD) and semimembranosus (SM) muscles. Fibroblast cell survival time was determined for understanding about the characteristics of proliferation rate between the two fibroblasts. We examined the collagen concentration and protein expression of collagen type I and III between the two fibroblasts. The mRNA expression of collagen synthesis and collagen degrading genes to elucidate the molecular mechanisms on toughness and tenderness through collagen production between the two fibroblast cells. From our results the growth rate, collagen content and protein expression of collagen type I and III were significantly higher in SM than LD muscle fibroblast. The mRNA expressions of collagen synthesized genes were increased whereas the collagen degrading genes were decreased in SM than LD muscle. Results from confocal microscopical investigation showed increased fluorescence of collagen type I and III appearing stronger in SM than LD muscle fibroblast. These results implied that the locomotion muscle had higher fibroblast growth rate, leads to produce more collagen, and cause tougher than positional muscle. This in vitro study mirrored that background toughness of various muscles in live animal is likely associated with fibroblast growth pattern, collagen synthesis and its gene expression.

Ligament Mediated Fragmentation of Viscoelastic Liquids

NASA Astrophysics Data System (ADS)

Keshavarz, Bavand; Houze, Eric C.; Moore, John R.; Koerner, Michael R.; McKinley, Gareth H.

2016-10-01

The breakup and atomization of complex fluids can be markedly different than the analogous processes in a simple Newtonian fluid. Atomization of paint, combustion of fuels containing antimisting agents, as well as physiological processes such as sneezing are common examples in which the atomized liquid contains synthetic or biological macromolecules that result in viscoelastic fluid characteristics. Here, we investigate the ligament-mediated fragmentation dynamics of viscoelastic fluids in three different canonical flows. The size distributions measured in each viscoelastic fragmentation process show a systematic broadening from the Newtonian solvent. In each case, the droplet sizes are well described by Gamma distributions which correspond to a fragmentation-coalescence scenario. We use a prototypical axial step strain experiment together with high-speed video imaging to show that this broadening results from the pronounced change in the corrugated shape of viscoelastic ligaments as they separate from the liquid core. These corrugations saturate in amplitude and the measured distributions for viscoelastic liquids in each process are given by a universal probability density function, corresponding to a Gamma distribution with nmin=4 . The breadth of this size distribution for viscoelastic filaments is shown to be constrained by a geometrical limit which can not be exceeded in ligament-mediated fragmentation phenomena.

Ligament Mediated Fragmentation of Viscoelastic Liquids.

PubMed

Keshavarz, Bavand; Houze, Eric C; Moore, John R; Koerner, Michael R; McKinley, Gareth H

2016-10-07

The breakup and atomization of complex fluids can be markedly different than the analogous processes in a simple Newtonian fluid. Atomization of paint, combustion of fuels containing antimisting agents, as well as physiological processes such as sneezing are common examples in which the atomized liquid contains synthetic or biological macromolecules that result in viscoelastic fluid characteristics. Here, we investigate the ligament-mediated fragmentation dynamics of viscoelastic fluids in three different canonical flows. The size distributions measured in each viscoelastic fragmentation process show a systematic broadening from the Newtonian solvent. In each case, the droplet sizes are well described by Gamma distributions which correspond to a fragmentation-coalescence scenario. We use a prototypical axial step strain experiment together with high-speed video imaging to show that this broadening results from the pronounced change in the corrugated shape of viscoelastic ligaments as they separate from the liquid core. These corrugations saturate in amplitude and the measured distributions for viscoelastic liquids in each process are given by a universal probability density function, corresponding to a Gamma distribution with n_{min}=4. The breadth of this size distribution for viscoelastic filaments is shown to be constrained by a geometrical limit which can not be exceeded in ligament-mediated fragmentation phenomena.

Usefulness of oblique axial scan in magnetic resonance imaging evaluation of anterior talofibular ligament in ankle sprain.

PubMed

Kim, Jin-su; Moon, Yong-ju; Choi, Yun Sun; Park, Young Uk; Park, Seung Min; Lee, Kyung Tai

2012-01-01

The purpose of the present study was to clarify the usefulness of the oblique axial scan parallel to the course of the anterior talofibular ligament in magnetic resonance imaging of the anterior talofibular ligament in patients with chronic ankle instability. We evaluated this anterior talofibular ligament view and routine axial magnetic resonance imaging planes of 115 ankles. We diagnosed the grade of the anterior talofibular ligament injury and confirmed full-length views of the anterior talofibular ligament. Associated lesions were also checked. The subjective diagnostic convenience of associated problems was determined. The full-length view of the anterior talofibular ligament was checked in 85 (73.9%) patients in the routine axial view and 112 (97.4%) patients in the anterior talofibular ligament view. The grade of injury increased in the anterior talofibular ligament view in 26 (22.6%) patients compared with the routine axial view. There were 64 associated injuries. The anterior inferior tibiofibular ligament, posterior inferior tibiofibular ligament, and posterior tibialis tendinitis were more easily diagnosed on the routine axial view than on the anterior talofibular ligament view. An additional anterior talofibular ligament view is useful in the evaluation of the anterior talofibular ligament in patients with chronic ankle instability. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Anatomy of Alar Ligament Part III: Biomechanical Study.

PubMed

Iwanaga, Joe; Sardi, Juan P; Laws, Tyler; Chapman, Jens R; Oskouian, Rod J; Tubbs, R Shane

2017-11-01

Four layers of ligamentous stabilizers comprise the craniocervical junction, and the second layer is composed of apical and paired alar ligaments. The purpose of this study is to establish the tensile strength of the alar ligaments for better understanding the implications that can arise from trauma and other pathologies in the craniocervical region. Nineteen sides from 10 fresh frozen adult cadaveric Caucasian heads were used in this study. The specimens were derived from 6 males and 4 females, and the age of the cadavers at death ranged from 67-90 years old. To measure the tensile strength, a tensile testing machine (M2-200, Mark-10 Corporation, Copiague, New York, USA) was used in this study. The force (N) necessary until failure for all alar ligaments ranged from 87-346 N with a mean of 186.9 ± 69.7 N. There was a significant difference when comparing tensile strength between males and females. Further studies will be necessary to determine their importance as secondary stabilizers and measure their ability to support similar forces when subject to rotation and lateral bending forces, as well as with flexion-extension. Copyright © 2017 Elsevier Inc. All rights reserved.

Biomechanical properties of interosseous proximal carpal row ligaments.

PubMed

Nikolopoulos, Fotios; Apergis, Emmanuel; Kefalas, Vassilios; Zoubos, Aristides; Soucacos, Panayiotis; Papagelopoulos, Panayiotis

2011-05-01

The Scapholunate (S-L) and Lunotriquetrum (L-Tr) ligaments have been extensively studied in the literature. A wide range of measurements has been reported for ultimate load and stiffness with different mechanical protocols. In this study, we examined the mechanical properties of both ligaments harvested from the same wrist. Fifteen fresh cadaver wrists were used to harvest eight S-L and four L-Tr. Testing was performed in quasi-static loading in a well defined direction for each ligament system. The ultimate load for S-L was 68-210 N with a mean value of 147 ± 54 N and a stiffness of 35.7 ± 9.6 N/mm. For L-Tr the ultimate load was 122-179 N with a mean value of 150 ± 24 N and a stiffness of 192 ± 60 N/mm. The two ligaments had nearly the same ultimate load, but the L-Tr had a higher stiffness (p = 0.05). These findings could be useful to assess the appropriate autologous autografts for reconstruction of the S-L and L-Tr. Copyright © 2010 Orthopaedic Research Society.

Cultured Human Fibroblast Biostimulation Using a 940 nm Diode Laser

PubMed Central

Illescas-Montes, Rebeca; Melguizo-Rodríguez, Lucía; Manzano-Moreno, Francisco Javier; García-Martínez, Olga; Ruiz, Concepción

2017-01-01

Background: Fibroblasts are the main cells involved in regeneration during wound healing. The objective was to determine the effect of 940 nm diode laser on cultured human fibroblasts using different irradiation regimens. Methods: The CCD-1064Sk human epithelial fibroblast cell line was treated with a 940 nm diode laser at different energy doses (power: 0.2–1 W and energy density: 1–7 J/cm2) using different transmission modes (continuous or pulsed). The effect on cell growth at 24 and 72 h post-treatment was examined by measuring the proliferative capacity, the impact on the cell cycle, and the effect on cell differentiation. Results: fibroblast proliferative capacity was increased at 24 and 72 h post-treatment as a function of the energy dose. The greatest increase was observed with a power of 0.2 or 0.5 W and energy density between 1 and 4 J/cm2; no difference was observed between continuous and pulsed modes. There were no significant differences in cell cycle between treated groups and controls. α-actin expression was increased by treatment, indicating enhanced cell differentiation. Conclusion: The 940 nm diode laser has biostimulating effects on fibroblasts, stimulating proliferative capacity and cell differentiation without altering the cell cycle. Further researches are necessary to explore its potential clinical usefulness in wound healing. PMID:28773152

Phenotypic differences between oral and skin fibroblasts in wound contraction and growth factor expression.

PubMed

Shannon, Diane B; McKeown, Scott T W; Lundy, Fionnuala T; Irwin, Chris R

2006-01-01

Wounds of the oral mucosa heal in an accelerated fashion with reduced scarring compared with cutaneous wounds. The differences in healing outcome between oral mucosa and skin could be because of phenotypic differences between the respective fibroblast populations. This study compared paired mucosal and dermal fibroblasts in terms of collagen gel contraction, alpha-smooth muscle actin expression (alpha-SMA), and production of the epithelial growth factors: keratinocyte growth factor (KGF) and hepatocyte growth factor/scatter factor (HGF). The effects of transforming growth factor -beta1 and -beta3 on each parameter were also determined. Gel contraction in floating collagen lattices was determined over a 7-day period. alpha-SMA expression by fibroblasts was determined by Western blotting. KGF and HGF expression were determined by an enzyme-linked immunosorbent assay. Oral fibroblasts induced accelerated collagen gel contraction, yet surprisingly expressed lower levels of alpha-SMA. Oral cells also produced significantly greater levels of both KGF and HGF than their dermal counterparts. Transforming growth factor-beta1 and -beta3, over the concentration range of 0.1-10 ng/mL, had similar effects on cell function, stimulating both gel contraction and alpha-SMA production, but inhibiting KGF and HGF production by both cell types. These data indicate phenotypic differences between oral and dermal fibroblasts that may well contribute to the differences in healing outcome between these two tissues.

Isokinetic evaluation of internal/external tibial rotation strength after the use of hamstring tendons for anterior cruciate ligament reconstruction.

PubMed

Armour, Tanya; Forwell, Lorie; Litchfield, Robert; Kirkley, Alexandra; Amendola, Ned; Fowler, Peter J

2004-01-01

Evaluation of the knee after an anterior cruciate ligament reconstruction with the use of the semitendinosus and gracilis (hamstring) autografts has primarily focused on flexion and extension strength. The semitendinosus and gracilis muscles contribute to internal tibial rotation, and it has been suggested that harvest of these tendons for the purpose of an anterior cruciate ligament reconstruction contributes to internal tibial rotation weakness. Internal tibial rotation strength may be affected by the semitendinosus and gracilis harvest after anterior cruciate ligament reconstruction. Prospective evaluation of internal and external tibial rotation strength. Inclusion criteria for subjects (N = 30): unilateral anterior cruciate ligament reconstruction at least 2 years previously, a stable anterior cruciate ligament (<5-mm side-to-side difference) at time of testing confirmed by surgeon and KT-1000 arthrometer, no history of knee problems after initial knee reconstruction, a normal contralateral knee, and the ability to comply with the testing protocol. In an attempt to minimize unwanted subtalar joint motion, subjects were immobilized using an ankle brace and tested at angular velocities of 60 degrees /s, 120 degrees /s, and 180 degrees /s at a knee flexion angle of 90 degrees . The mean peak torque measurements for internal rotation strength of the operative limb (60 degrees /s, 17.4 +/- 4.5 ft-lb; 120 degrees /s, 13.9 +/- 3.3 ft-lb; 180 degrees /s, 11.6 +/- 3.0 ft-lb) were statistically different compared to the nonoperated limb (60 degrees /s, 20.5 +/- 4.7 ft-lb; 120 degrees /s, 15.9 +/- 3.8 ft-lb; 180 degrees /s, 13.4 +/- 3.8 ft-lb) at 60 degrees /s (P = .012), 120 degrees /s (P = .036), and 180 degrees /s (P = .045). The nonoperative limb demonstrated greater strength at all speeds. The mean torque measurements for external rotation were statistically similar when compared to the nonoperated limb at all angular velocities. We have shown through our study that patients who undergo surgical intervention to repair a torn anterior cruciate ligament with the use of autogenous hamstring tendons demonstrate with weaker internal tibial rotation postoperatively at 2 years when compared to the contralateral limb.

Subfailure injury of the rabbit anterior cruciate ligament.

PubMed

Panjabi, M M; Yoldas, E; Oxland, T R; Crisco, J J

1996-03-01

Ligamentous injuries range in severity from a simple sprain to a complete rupture. Although sprains occur more frequently than complete failures, only a few studies have investigated the phenomena of these subfailure injuries. The purpose of our study was to document the changes in the load-deformation curve until the failure point, after the ligament has been subjected to an 80% subfailure stretch. Thirteen paired fresh rabbit bone-anterior cruciate ligament-bone preparations were used. One of the pairs (control) was stretched until failure; the other (experimental) was first stretched to 80% of the failure deformation of the control and then stretched to failure. Comparisons were made between the load-deformation curves of the experimental and control specimens. The nonlinear load-deformation curves were characterized by eight parameters: failure load (Ffail), failure deformation (Dfail), energy until failure (Efail), deformations measured at 5, 10, 25, and 50% of the failure load (D5, D10, D25, and D50, respectively), and stiffness measured at 50% of the failure force (K50). There were no significant differences in the values for Ffail, Dfail, and Efail between the experimental and control ligaments (p > 0.33). In contrast, the deformation values were all larger for the experimental than the control ligaments (p > 0.01). The deformations D5, D10, D25, and D50 (mean +/- SD) for the control were 0.36 +/- 0.13, 0.49 +/- 0.23, 0.81 +/- 0.35, and 1.23 +/- 0.41 mm. The corresponding deformations for the experimental ligaments were, respectively, 209, 186, 153, and 130% of the control values. K50 was also greater for the experimental ligament (125.0 +/- 41.7 N/mm compared with 108.7 +/- 31.4 N/mm, p < 0.03). These findings indicate that even though the strength of the ligament did not change due to a subfailure injury, the shape of the load-displacement curve, especially at low loads, was significantly altered. Under the dynamic in vivo loading conditions of daily living, this may result in increased joint laxity, additional loads being applied to other joint structures, and, with time, to joint problems.

Anatomic and Histological Investigation of the Anterolateral Capsular Complex in the Fetal Knee.

PubMed

Sabzevari, Soheil; Rahnemai-Azar, Amir Ata; Albers, Marcio; Linde, Monica; Smolinski, Patrick; Fu, Freddie H

2017-05-01

There is currently disagreement with regard to the presence of a distinct ligament in the anterolateral capsular complex of the knee and its role in the pivot-shift mechanism and rotatory laxity of the knee. To investigate the anatomic and histological properties of the anterolateral capsular complex of the fetal knee to determine whether there exists a distinct ligamentous structure running from the lateral femoral epicondyle inserting into the anterolateral tibia. Descriptive laboratory study. Twenty-one unpaired, fresh fetal lower limbs, gestational age 18 to 22 weeks, were used for anatomic investigation. Two experienced orthopaedic surgeons performed the anatomic dissection using loupes (magnification ×3.5). Attention was focused on the anterolateral and lateral structures of the knee. After the skin and superficial fascia were removed, the iliotibial band was carefully separated from underlying structures. The anterolateral capsule was then examined under internal and external rotation and varus-valgus manual loading and at different knee flexion angles for the presence of any ligamentous structures. Eight additional unpaired, fetal lower limbs, gestational age 11 to 23 weeks, were used for histological analysis. This study was not able to prove the presence of a distinct capsular or extracapsular ligamentous structure in the anterolateral capsular complex area. The presence of the fibular collateral ligament, a distal attachment of the biceps femoris, the entire lateral capsule, the iliotibial band, and the popliteus tendon in the anterolateral and lateral area of the knee was confirmed in all the samples. Histological analysis of the anterolateral capsule revealed a loose, hypocellular connective tissue with less organized collagen fibers compared with ligament and tendinous structures. The main finding of this study was that the presence of a distinct ligamentous structure in the anterolateral complex is not supported from a developmental point of view, while all other anatomic structures were present. The inability to prove the existence of a distinct ligamentous structure, called the anterolateral ligament, in the anterolateral knee capsule may indicate that the other components of the anterolateral complex, such as the lateral capsule, the iliotibial band, and its capsule-osseous layer, are more important for knee rotatory stability.

Profibrotic Phenotype of Conjunctival Fibroblasts from Mucous Membrane Pemphigoid

PubMed Central

Saw, Valerie P.J.; Schmidt, Enno; Offiah, Ifeoma; Galatowicz, Grazyna; Zillikens, Detlef; Dart, John K.G.; Calder, Virginia L.; Daniels, Julie T.

2011-01-01

Ocular mucous membrane pemphigoid is an immunobullous disease in which excessive conjunctival fibrosis causes blindness, and the pathogenesis of scarring is incompletely understood. To establish whether profibrotic fibroblasts with an altered phenotype exist in ocular mucous membrane pemphigoid, we compared the functional characteristics of pemphigoid conjunctival fibroblasts to normal conjunctival fibroblasts with respect to cell division; migration; collagen contraction; matrix metalloproteinase, secretion of collagen and chemokines; and myofibroblast differentiation. We found that pemphigoid fibroblasts showed increased cell division (P = 0.01), increased migration in serum-free medium (72 ± 18 migrated cells versus 33 ± 11, P = 0.04), increased collagen contraction in the presence of 10 ng/ml tumor necrosis factor-α, increased collagen type I secretion (P = 0.03), increased secretion of matrix metalloproteinase-3 (P = 0.03), and increased secretion of eotaxin in response to interleukin-13 (P = 0.04). Differences between pemphigoid and normal conjunctival fibroblasts with respect to collagen contraction and MMP secretion in the presence of interleukin-13 were also observed. Together, these findings indicate that pemphigoid conjunctival fibroblasts have a profibrotic phenotype that is maintained in vitro. No differences between pemphigoid fibroblasts obtained from acutely inflamed versus clinically uninflamed conjunctiva were observed. Developing effective antifibrotic therapies will require understanding of the mechanisms that both induce and maintain the profibrotic phenotype. PMID:21224056

Electromechanical delay of the knee flexor muscles is impaired after harvesting hamstring tendons for anterior cruciate ligament reconstruction.

PubMed

Ristanis, Stavros; Tsepis, Elias; Giotis, Dimitrios; Stergiou, Nicholas; Cerulli, Guiliano; Georgoulis, Anastasios D

2009-11-01

Changes in electromechanical delay during muscle activation are expected when there are substantial alterations in the structural properties of the musculotendinous tissue. In anterior cruciate ligament reconstruction, specific tendons are being harvested for grafts. Thus, there is an associated scar tissue development at the tendon that may affect the corresponding electromechanical delay. This study was conducted to investigate whether harvesting of semitendinosus and gracilis tendons for anterior cruciate ligament reconstruction will affect the electromechanical delay of the knee flexors. Case-control study; Level of evidence, 3. The authors evaluated 12 patients with anterior cruciate ligament reconstruction with a semitendinosus and gracilis autograft, 2 years after the reconstruction, and 12 healthy controls. Each participant performed 4 maximally explosive isometric contractions with a 1-minute break between contractions. The surface electromyographic activity of the biceps femoris and the semitendinosus was recorded from both legs during the contractions. The statistical comparisons revealed significant increases of the electromechanical delay of the anterior cruciate ligament-reconstructed knee for both investigated muscles. Specifically, the electromechanical delay values were increased for both the biceps femoris (P = .029) and the semitendinosus (P = .005) of the reconstructed knee when compared with the intact knee. Comparing the anterior cruciate ligament-reconstructed knee against healthy controls revealed similar significant differences for both muscles (semitendinosus, P = .011; biceps femoris, P = .024). The results showed that harvesting the semitendinosus and gracilis tendons for anterior cruciate ligament reconstruction significantly increased the electromechanical delay of the knee flexors. Increased hamstring electromechanical delay might impair knee safety and performance by modifying the transfer time of muscle tension to the tibia and therefore affecting muscle response during sudden movements in athletic activities. However, further investigation is required to identify whether the increased electromechanical delay of the hamstrings can actually influence optimal sports performance and increase the risk for knee injury in athletes with anterior cruciate ligament reconstructions.

In vitro and in vivo assessment of oral autologous artificial connective tissue characteristics that influence its performance as a graft.

PubMed

Fontanilla, Marta Raquel; Espinosa, Lady Giovanna

2012-09-01

Several studies have evaluated proteins secreted by fibroblasts comprising skin substitutes, finding that they are secreted in combinations and concentrations that promote wound healing. However, assessment of proteins secreted by oral fibroblasts forming a part of oral substitutes is scarce. In our previous work, collagen type-I scaffolds (CSs) and autologous artificial connective tissue (AACT) were produced and implanted in rabbit oral lesions, evidencing that AACT outperforms CS. The present work determined the secreted factor profile of AACT in the time of grafting as well as that of the AACT embedded in the clot. It also evaluated the proliferation and viability of AACT fibroblasts to establish the dwell time of these cells in the grafted area. Finally, it assessed whether CS, AACT, and clot-embedded AACT increase fibroblast recruitment induced by a fibrin clot, because the cell migratory response has been associated with the wound-healing outcome. We found that some of the factors secreted by AACT fibroblasts are significantly different from those secreted by clot-embedded AACT fibroblasts. Also, that the profile of proteins secreted by AACT fibroblasts and clot-embedded AACT fibroblasts is different from already reported protein secretion profiles of other engineered tissues used in treating oral mucosa wounds. It was also found that AACT fibroblasts are viable when grafted and remain in the treated area for almost 2 weeks, and that the migratory response of fibroblasts to tissue-substitute stimulus is significantly less than the migratory response induced by the clot alone. Overall, data suggest that AACT secretion of proteins is modulated by three-dimensionality and environment factors. This bioactivity and the fact that AACT does not increase fibroblast migration can be held accountable for AACT's good performance as a graft.

Morphologic and biomechanical comparison of spinous processes and ligaments from scoliotic and kyphotic patients.

PubMed

Beaubien, Brian P; Freeman, Andrew L; Buttermann, Glenn R

2016-01-25

The spinous processes and supraspinous and interspinous ligaments (SSL and ISL, respectively) limit flexion and may relate to spinal curvature. Spinous process angles and mechanical properties of explanted human thoracic posterior SSL/ISL complexes were compared for scoliosis (n=14) vs. kyphosis (n=8) patients. The median thoracic coronal Cobb angle for scoliosis patients was 48°, and sagittal angles for kyphosis patients was 78°. Spinous processes were gripped and four strain steps of 4% were applied and held. Percent relaxation was calculated over each step, equilibrium load data were fit to an exponential equation, and a Kelvin model was fit to the load from all four curves. Failure testing was also performed. Median ligament complex dimensions from scoliosis and kyphosis patients were, respectively: ISL width=16.5mm and 16.0mm; SSL width=4.3mm and 3.8mm; ISL+SSL area=17.2mm and 25.7mm; these differences were not significant. Significant differences did exist in terms of spinous process angle vs. spine axis (47° for scoliosis and 32° for kyphosis) and SSL thickness (2.1mm for scoliosis and 3.0mm for kyphosis). Fourth-step median relaxation was 42% for scoliosis and 49% for kyphosis. Median linear region stiffness was 42N/mm for scoliosis and 51N/mm for kyphosis. Median failure load was 191N for scoliotic and 175N for kyphotic ligaments. Differences in loading, relaxation, viscoelastic and failure parameters were not statistically significant, except for a trend for greater initial rate of relaxation (T1) for scoliosis ligaments. However, we found significant morphological differences related to the spinous processes, which suggests a need for future biomechanical studies related to the musculoskeletal aspects of spinal alignment and posture. Copyright © 2015 Elsevier Ltd. All rights reserved.

MRI appearance of surgically proven abnormal accessory anterior-inferior tibiofibular ligament (Bassett's ligament).

PubMed

Subhas, Naveen; Vinson, Emily N; Cothran, R Lee; Santangelo, James R; Nunley, James A; Helms, Clyde A

2008-01-01

A thickened accessory anterior-inferior tibiofibular ligament (Bassett's ligament) of the ankle can be a cause of ankle impingement. Its imaging appearance is not well described. The purpose of this study was to determine if the ligament could be identified on magnetic resonance imaging (MRI), to determine associated abnormalities, and to determine if MRI could be used to differentiate normal from abnormal. Eighteen patients with a preoperative ankle MRI and an abnormal Bassett's ligament reported at surgery were found retrospectively. A separate cohort of 18 patients was selected as a control population. The presence of Bassett's ligament and its thickness were noted. The integrity and appearance of the lateral ankle ligaments, talar dome cartilage, and anterolateral gutter were also noted. In 34 of the 36 cases (94%), Bassett's ligament was identified on MRI. The ligament was seen in all three imaging planes and most frequently in the axial plane. The mean thickness of the ligament in the surgically abnormal cases was 2.37 mm, compared with 1.87 mm in the control with a p value=0.015 (t test). Nine of the 18 abnormal cases (50%) had talar dome cartilage lesions as a result of contact with the ligament at surgery, with only 3 cases of high-grade defects seen on MRI. Fourteen of the 18 abnormal cases (78%) had of synovitis or scarring in the lateral gutter at surgery, with only 5 cases with scarring seen on MRI. The anterior-inferior tibiofibular ligament was abnormal or torn in 8 of the 18 abnormal cases (44%) by MRI and confirmed in only 3 cases at surgery. Bassett's ligament can be routinely identified on MRI and was significantly thicker in patients who had it resected at surgery. An abnormal Bassett's ligament is often present in the setting of a normal anterior-inferior tibiofibular ligament. The cartilage abnormalities and synovitis associated with an abnormal Bassett's ligament are poorly detected by conventional MRI.

Gross, Arthroscopic, and Radiographic Anatomies of the Anterior Cruciate Ligament: Foundations for Anterior Cruciate Ligament Surgery.

PubMed

Irarrázaval, Sebastián; Albers, Marcio; Chao, Tom; Fu, Freddie H

2017-01-01

The anterior cruciate ligament (ACL) is one of the more studied structures in the knee joint. It is not a tubular structure, but is much narrower in its midsubstance and broader at its ends, producing an hourglass shape. The ACL is composed of 2 functional bundles, the anteromedial and posterolateral bundles, that are named for their location of insertion on the anterior surface of the tibial plateau. Although the relative contribution in terms of total cross-sectional area of the ACL has been noted to be equal in regards to each bundle, dynamically these bundles demonstrate different properties for knee function. Copyright © 2016 Elsevier Inc. All rights reserved.

A visco-hyperelastic constitutive model for human spine ligaments.

PubMed

Jiang, Yugang; Wang, Yu; Peng, Xiongqi

2015-03-01

Human spine ligaments show a highly non-linear, strain rate dependent biomechanical behavior under tensile tests. A visco-hyperelastic fiber-reinforced constitutive model was accordingly developed for human ligaments, in which the energy density function is decomposed into two parts. The first part represents the elastic strain energy stored in the soft tissue, and the second part denotes the energy dissipated due to its inherent viscous characteristics. The model is applied to various human spinal ligaments including the anterior and posterior longitudinal ligaments, ligamentum flavum, capsular ligament, and interspinous ligament. Material parameters for each type of ligament were obtained by curve-fitting with corresponding experimental data available in the literature. The results indicate that the model presented here can properly characterize the visco-hyperelastic biomechanical behavior of human spine ligaments.

The transverse occipital ligament: anatomy and potential functional significance.

PubMed

Tubbs, R Shane; Griessenauer, Christoph J; McDaniel, Jenny Gober; Burns, Amanda M; Kumbla, Anjali; Cohen-Gadol, Aaron A

2010-03-01

Knowledge of the anatomy of ligaments that bind the craniocervical junction is important for treating patients with lesions of this region. Although the anatomy and function of these ligaments have been well described, those of the transverse occipital ligament (TOL) have remained enigmatic. To describe the anatomy and functions of the transverse occipital ligament. Via a posterior approach, 9 cadaveric specimens underwent dissection of the craniocervical junction with special attention to the presence and anatomy of the TOL. The TOL was identified in 77.8% of the specimens. The ligament was found to be rectangular with fibers running horizontally between the lateral aspects of the foramen magnum. The attachment of each ligament near the occipital condyle was consistent, and each ligament was found superior to the transverse portion of the cruciform ligament and inserted just posterior to the lateral attachment sites of the alar ligaments. The average width, length, and thickness of the TOL was 0.34, 1.94, and 0.13 cm, respectively. The TOL in some specimens also had connections to the alar and transverse ligaments. The TOL was found in the majority of our specimens. The possible functions of this ligament when attached to the alar ligaments include providing additional support to these structures in stabilizing lateral bending, flexion, and axial rotation of the head. Knowledge of this ligament may aid in further understanding craniocervical stability and help in differentiating normal from pathology via imaging modalities.

Surgical anatomy of retaining ligaments in the periorbital area.

PubMed

Hwang, Kun; Nam, Yong Seok; Kim, Dae Joong; Han, Seung Ho

2008-05-01

The aim of this study was to elucidate an anatomic detail of ligamentous attachments in the periorbital areas of Korean cadavers. Sixty-one hemifaces of 35 Korean adult cadavers (age range, 43-101 years; 23 men and 9 women) were used. Fifty-five specimens were dissected, 12 used for tension measurement, and 6 for histologic study. Definite retaining ligaments were found in 42 (76.4%) of 55 dissected hemifaces. We named the retaining ligaments attached to the bony orbit periorbital ligament (PL). Periorbital ligament was in the medial and lateral orbital area. Medial PL (MPL) was curvilinear shaped and between an angle of +23.4 and -23.1 degrees on the horizontal at a midpupillary line. Lateral PL (LPL) was crescent shape and between an angle of +39.1 and -42.1 degrees. The MPL was vertical along the medical orbital rim just outer to the orbital septum. The width of MPL was 0.8 mm, and vertical length was 22.1 mm. The crescent-shaped LPL was located a few millimeters (up to 4 mm) lateral to the lateral orbital rim. The maximum width of LPL was 6.9 mm, and vertical length was 28.2 mm. The breaking strength of the LPL (14.2+/-11.1 N) was significantly higher (P=0.016) than that of the central lower eyelid (5.1+/-2.5 N). The breaking strength of the MPL (8.4+/-3.0 N) was also significantly higher (P=0.013) than that of the central lower eyelid. However, there was no significant difference between LPL and MPL (P=0.055). Knowledge of the retaining ligaments is conducive to performing the midfacial rejuvenating surgery.

Immunomodulatory Properties of Induced Pluripotent Stem Cell-Derived Mesenchymal Cells.

PubMed

Ng, Jia; Hynes, Kim; White, Gregory; Sivanathan, Kisha Nandini; Vandyke, Kate; Bartold, Peter Mark; Gronthos, Stan

2016-12-01

MSC-like populations derived from induced pluripotent stem cells (iPSC-MSC) serve as an alternative stem cell source due to their high proliferative capacity. In this study, we assessed the immunomodulatory potential of iPSC-MSC generated from periodontal ligament (PDL) and gingival (GF) tissue. The iPSC-MSC lines exhibited a similar level of suppression of mitogen-stimulated peripheral blood mononuclear cells (PBMNC) proliferation compared to their respective parental fibroblast populations in vitro. Moreover, iPSC-MSC demonstrated the ability to suppress T-cells effector cells, Th1/Th2/Th17 populations, and increase levels of Treg cells. In order to investigate the mechanisms involved, expression of common MSC-derived soluble factors known to supress lymphocyte proliferation were assessed in iPSC-MSC cultured with PBMNC with direct cell-cell contact or separated in transwells. Real-time PCR analysis of factors known to be involved in MSC mediated immune regulation, found a general trend of elevated IDO1 and IL6 transcript levels in iPSC-MSC lines and their respective primary cells co-cultured with activated PBMNC, with a wide range of gene expression levels between the different mesenchymal cell types. The results suggest that different iPSC-MSC may be useful as a potential alternative source of cells for future clinical use in therapeutic applications because of their potent immunosuppressive properties. J. Cell. Biochem. 117: 2844-2853, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Measuring alignment of loading fixture

DOEpatents

Scavone, Donald W.

1989-01-01

An apparatus and method for measuring the alignment of a clevis and pin type loading fixture for compact tension specimens include a pair of substantially identical flat loading ligaments. Each loading ligament has two apertures for the reception of a respective pin of the loading fixture and a thickness less than one-half of a width of the clevis opening. The pair of loading ligaments are mounted in the clevis openings at respective sides thereof. The loading ligaments are then loaded by the pins of the loading fixture and the strain in each loading ligament is measured. By comparing the relative strain of each loading ligament, the alignment of the loading fixture is determined. Preferably, a suitable strain gage device is located at each longitudinal edge of a respective loading ligament equidistant from the two apertures in order to determine the strain thereat and hence the strain of each ligament. The loading ligaments are made substantially identical by jig grinding the loading ligaments as a matched set. Each loading ligament can also be individually calibrated prior to the measurement.

Fibroblast heterogeneity: implications for human disease.

PubMed

Lynch, Magnus D; Watt, Fiona M

2018-01-02

Fibroblasts synthesize the extracellular matrix of connective tissue and play an essential role in maintaining the structural integrity of most tissues. Researchers have long suspected that fibroblasts exhibit functional specialization according to their organ of origin, body site, and spatial location. In recent years, a number of approaches have revealed the existence of fibroblast subtypes in mice. Here, we discuss fibroblast heterogeneity with a focus on the mammalian dermis, which has proven an accessible and tractable system for the dissection of these relationships. We begin by considering differences in fibroblast identity according to anatomical site of origin. Subsequently, we discuss new results relating to the existence of multiple fibroblast subtypes within the mouse dermis. We consider the developmental origin of fibroblasts and how this influences heterogeneity and lineage restriction. We discuss the mechanisms by which fibroblast heterogeneity arises, including intrinsic specification by transcriptional regulatory networks and epigenetic factors in combination with extrinsic effects of the spatial context within tissue. Finally, we discuss how fibroblast heterogeneity may provide insights into pathological states including wound healing, fibrotic diseases, and aging. Our evolving understanding suggests that ex vivo expansion or in vivo inhibition of specific fibroblast subtypes may have important therapeutic applications.

Anatomy of the ankle ligaments: a pictorial essay.

PubMed

Golanó, Pau; Vega, Jordi; de Leeuw, Peter A J; Malagelada, Francesc; Manzanares, M Cristina; Götzens, Víctor; van Dijk, C Niek

2016-04-01

Understanding the anatomy of the ankle ligaments is important for correct diagnosis and treatment. Ankle ligament injury is the most frequent cause of acute ankle pain. Chronic ankle pain often finds its cause in laxity of one of the ankle ligaments. In this pictorial essay, the ligaments around the ankle are grouped, depending on their anatomic orientation, and each of the ankle ligaments is discussed in detail.

Kinematic analysis of anterior cruciate ligament reconstruction in total knee arthroplasty

PubMed Central

Liu, Hua-Wei; Ni, Ming; Zhang, Guo-Qiang; Li, Xiang; Chen, Hui; Zhang, Qiang; Chai, Wei; Zhou, Yong-Gang; Chen, Ji-Ying; Liu, Yu-Liang; Cheng, Cheng-Kung; Wang, Yan

2016-01-01

Background: This study aims to retain normal knee kinematics after knee replacement surgeries by reconstructing anterior cruciate ligament during total knee arthroplasty. Method: We use computational simulation tools to establish four dynamic knee models, including normal knee model, posterior cruciate ligament retaining knee model, posterior cruciate ligament substituting knee model, and anterior cruciate ligament reconstructing knee model. Our proposed method utilizes magnetic resonance images to reconstruct solid bones and attachments of ligaments, and assemble femoral and tibial components according representative literatures and operational specifications. Dynamic data of axial tibial rotation and femoral translation from full-extension to 135 were measured for analyzing the motion of knee models. Findings: The computational simulation results show that comparing with the posterior cruciate ligament retained knee model and the posterior cruciate ligament substituted knee model, reconstructing anterior cruciate ligament improves the posterior movement of the lateral condyle, medial condyle and tibial internal rotation through a full range of flexion. The maximum posterior translations of the lateral condyle, medial condyle and tibial internal rotation of the anterior cruciate ligament reconstructed knee are 15.3 mm, 4.6 mm and 20.6 at 135 of flexion. Interpretation: Reconstructing anterior cruciate ligament in total knee arthroplasty has been approved to be an more efficient way of maintaining normal knee kinematics comparing to posterior cruciate ligament retained and posterior cruciate ligament substituted total knee arthroplasty. PMID:27347334

A review of ultrasonographic methods for the assessment of the anterior cruciate ligament in patients with knee instability – diagnostics using a posterior approach

PubMed Central

Kielar, Maciej

2016-01-01

Aim The purpose of the study was to improve the ultrasonographic assessment of the anterior cruciate ligament by an inclusion of a dynamic element. The proposed functional modification aims to restore normal posterior cruciate ligament tension, which is associated with a visible change in the ligament shape. This method reduces the risk of an error resulting from subjectively assessing the shape of the posterior cruciate ligament. It should be also emphasized that the method combined with other ultrasound anterior cruciate ligament assessment techniques helps increase diagnostic accuracy. Methods Ultrasonography is used as an adjunctive technique in the diagnosis of anterior cruciate ligament injury. The paper presents a sonographic technique for the assessment of suspected anterior cruciate ligament insufficiency supplemented by the use of a dynamic examination. This technique can be recommended as an additional procedure in routine ultrasound diagnostics of anterior cruciate ligament injuries. Results Supplementing routine ultrasonography with the dynamic assessment of posterior cruciate ligament shape changes in patients with suspected anterior cruciate ligament injury reduces the risk of subjective errors and increases diagnostic accuracy. This is important especially in cases of minor anterior knee instability and bilateral anterior knee instability. Conclusions An assessment of changes in posterior cruciate ligament using a dynamic ultrasound examination effectively complements routine sonographic diagnostic techniques for anterior cruciate ligament insufficiency. PMID:27679732

Anatomical considerations on the discomalleolar ligament

PubMed Central

RODRÍGUEZ-VÁZQUEZ, J. F.; MÉRIDA-VELASCO, J. R.; MÉRIDA-VELASCO, J. A.; JIMÉNEZ-COLLADO, J.

1998-01-01

A study was carried out on the discomalleolar ligament by dissection of adult human cadavers. The ligament corresponds to the most internal portion of the superior lamina of the temporomandibular joint capsule. It extends from the posterointernal portion of the temporomandibular joint disc, penetrates the petrotympanic fissure and reaches the malleus of the middle ear. Because of its morphology and anatomical arrangement the discomalleolar ligament should be considered as an intrinsic ligament of the temporomandibular joint and distinguished from the tympanic portion of the sphenomandibular ligament (anterior ligament of the malleus). PMID:9723988

The role of the medial ligaments in lateral stabilization of the ankle joint: an in vitro study.

PubMed

Ziai, Pejman; Benca, Emir; Skrbensky, Gobert V; Wenzel, Florian; Auffarth, Alexander; Krpo, Selma; Windhager, Reinhard; Buchhorn, Tomas

2015-07-01

The deltoid ligament complex is known as medial stabilizer in the ankle against pronation/eversion. Lateral dual-ligament laxity often results in chronic ankle instability with recurring ankle sprain trauma. The goal of this study is to examine the lateral stabilizing role of the deltoid ligament complex against supination/inversion in case of existing lateral ligament instability. A torsion simulation was performed on 12 fresh human lower leg cadaver specimens in a loading frame and a specially designed mounting platform. The preset torsion between tibia and calcaneus was primarily set at 30° of internal rotation on specimen in plantar flexion and hindfoot inversion. The measured variable was the resisting torque recorded around mechanical tibial axis, which ensures stability in ankle sprain trauma. The first series of measurements were performed on healthy specimens and the following after transecting structures in following order: anterior talofibular ligament (ATFL) in combination with calcaneofibular ligament (CFL), followed by anterior tibiotalar ligament and posterior tibiotalar ligament and finally tibiocalcaneal ligament (TCL). The combined lateral ATFL and CFL instability showed a decrease in the resisting torque, which ensures stability in ankle sprain trauma. Only a transection of TCL (superficial layer of deltoid ligament complex) with existing lateral dual-ligament instability results in a significant decrease in torque (p<0.0001). The goal of the study was to provide the orthopaedic and/or trauma surgeon with quantitative data that may be referred to the substantial stabilizing effect of TCL against supination/inversion in the ankle joint in case of repetitive sprain trauma at a present lateral ligament lesion. Diagnostics of and treatment for lateral ligament instability need to consider the deltoid ligament complex,especially TCL in clinical routine.

Spray-painted human fibronectin coating as an effective strategy to enhance graft ligamentization of a polyethylene terephthalate artificial ligament.

PubMed

Li, Hong; Chen, Chen; Ge, Yunsheng; Chen, Shiyi

2014-05-01

To enhance graft ligamentization after anterior cruciate ligament (ACL) reconstruction, human fibronectin (FN) was coated on polyethylene terephthalate (PET) ligaments by spray painting. The FN-coated PET ligaments were investigated in vitro using rat mesenchymal stromal cells (MSCs). MSCs cultured on FN-coated grafts resulted in similar cell densities and amounts of proliferating cells with control grafts without coating. The FN-coated group not only gave rise to MSC-derived collagen-like tissues but also enhanced the expression of collagen-I gene. Furthermore, rat ACL reconstruction models were used to evaluate the effect of the FN coating in vivo. The FN coating significantly promoted new ligament tissue regeneration into the graft fibers. In conclusion, sprayed FN coating had a positive effect to enhance graft ligamentization of PET artificial ligament.

The Influence of Joint Distraction Force on the Soft-Tissue Balance Using Modified Gap-Balancing Technique in Posterior-Stabilized Total Knee Arthroplasty.

PubMed

Nagai, Kanto; Muratsu, Hirotsugu; Takeoka, Yoshiki; Tsubosaka, Masanori; Kuroda, Ryosuke; Matsumoto, Tomoyuki

2017-10-01

During modified gap-balancing technique, there is no consensus on the best method for obtaining appropriate soft-tissue balance and determining the femoral component rotation. Sixty-five varus osteoarthritic patients underwent primary posterior-stabilized total knee arthroplasty using modified gap-balancing technique. The influence of joint distraction force on the soft-tissue balance measurement during the modified gap-balancing technique was evaluated with Offset Repo-Tensor between the osteotomized surfaces at extension, and between femoral posterior condyles and tibial osteotomized surface at flexion of the knee before the resection of femoral posterior condyles. The joint center gap (millimeters) and varus ligament balance (°) were measured under 20, 40, and 60 pounds of joint distraction forces, and the differences in these values at extension and flexion (the value at flexion minus the value at extension) were also calculated. The differences in joint center gap (-6.7, -6.8, and -6.9 mm for 20, 40, and 60 pounds, respectively) and varus ligament balance (3.5°, 3.8°, and 3.8°) at extension and flexion were not significantly different among different joint distraction forces, although the joint center gap and varus ligament balance significantly increased stepwise at extension and flexion as the joint distraction force increased. The difference in joint center gap and varus ligament balance at extension and flexion were consistent even among the different joint distraction forces. This novel index would be useful for the determination of femoral component rotation during the modified gap-balancing technique. Copyright © 2017 Elsevier Inc. All rights reserved.

Neck ligament strength is decreased following whiplash trauma

PubMed Central

Tominaga, Yasuhiro; Ndu, Anthony B; Coe, Marcus P; Valenson, Arnold J; Ivancic, Paul C; Ito, Shigeki; Rubin, Wolfgang; Panjabi, Manohar M

2006-01-01

Background Previous clinical studies have documented successful neck pain relief in whiplash patients using nerve block and radiofrequency ablation of facet joint afferents, including capsular ligament nerves. No previous study has documented injuries to the neck ligaments as determined by altered dynamic mechanical properties due to whiplash. The goal of the present study was to determine the dynamic mechanical properties of whiplash-exposed human cervical spine ligaments. Additionally, the present data were compared to previously reported control data. The ligaments included the anterior and posterior longitudinal, capsular, and interspinous and supraspinous ligaments, middle-third disc, and ligamentum flavum. Methods A total of 98 bone-ligament-bone specimens (C2–C3 to C7-T1) were prepared from six cervical spines following 3.5, 5, 6.5, and 8 g rear impacts and pre- and post-impact flexibility testing. The specimens were elongated to failure at a peak rate of 725 (SD 95) mm/s. Failure force, elongation, and energy absorbed, as well as stiffness were determined. The mechanical properties were statistically compared among ligaments, and to the control data (significance level: P < 0.05; trend: P < 0.1). The average physiological ligament elongation was determined using a mathematical model. Results For all whiplash-exposed ligaments, the average failure elongation exceeded the average physiological elongation. The highest average failure force of 204.6 N was observed in the ligamentum flavum, significantly greater than in middle-third disc and interspinous and supraspinous ligaments. The highest average failure elongation of 4.9 mm was observed in the interspinous and supraspinous ligaments, significantly greater than in the anterior longitudinal ligament, middle-third disc, and ligamentum flavum. The average energy absorbed ranged from 0.04 J by the middle-third disc to 0.44 J by the capsular ligament. The ligamentum flavum was the stiffest ligament, while the interspinous and supraspinous ligaments were most flexible. The whiplash-exposed ligaments had significantly lower (P = 0.036) failure force, 149.4 vs. 186.0 N, and a trend (P = 0.078) towards less energy absorption capacity, 308.6 vs. 397.0 J, as compared to the control data. Conclusion The present decreases in neck ligament strength due to whiplash provide support for the ligament-injury hypothesis of whiplash syndrome. PMID:17184536

Extrinsic wrist ligaments: prevalence of injury by magnetic resonance imaging and association with intrinsic ligament tears.

PubMed

Taneja, Atul K; Bredella, Miriam A; Chang, Connie Y; Joseph Simeone, F; Kattapuram, Susan V; Torriani, Martin

2013-01-01

The objective of this study was to determine the prevalence of extrinsic wrist ligament injury by magnetic resonance imaging and its association with intrinsic ligament tears. We reviewed conventional magnetic resonance images performed over a 5-year period from adult patients in the setting of wrist trauma. Two musculoskeletal radiologists examined the integrity of wrist ligaments and presence of bone abnormalities. In a cohort of 75 subjects, extrinsic ligament injury was present in 75%, with radiolunotriquetral being most frequently affected (45%). Intrinsic ligament injury was present in 60%. Almost half of subjects had combined intrinsic and extrinsic ligament injury. Bone abnormalities were seen in 69%. The rate of extrinsic injury was higher in subjects with bone injury (P = 0.008). There is high prevalence of extrinsic ligament injury in the setting of wrist trauma, especially in the presence of bone abnormalities, with combined injury of intrinsic and extrinsic ligaments in about half of cases.

Comparison of fibroblast cell regeneration in three different concentrations of Wharton’s Jelly mesenchymal stem cells conditioned medium (WJMSCs-CM)

NASA Astrophysics Data System (ADS)

Untoro, E. G.; Asrianti, D.; Usman, M.; Meidyawati, R.; Margono, A.

2017-08-01

Wharton’s Jelly-derived mesenchymal stem cells (WJMSCs) have gained interest as an alternative source of stem cells for regenerative medicine. Although many studies have characterized Wharton’s Jelly biologically, the effects of different concentrations in a cultured medium have not yet been compared. Damaged fibroblasts, the primary components of irreversible dental pulpitis, irreversibly impair the ability to regenerate and lead to the disruption of extracellular matrix. This study was performed to evaluate the potency of three WJMSCs-CM concentrations in improving serum-starved fibroblasts. Fibroblasts were cultivated in five passages, and divided into four groups. The first group (the control group) consisted of fibroblast cells that had been treated using starvation methods. The other groups (the treatment groups) were treated with various concentration of WJMSCs-CM (50%, 25% and 12.5%). Proliferative ability was evaluated using a cell count method and analyzed with a one-way ANOVA. Cultivation of serum-starved fibroblasts produced significantly higher cell counts in 12.5% WJMSCs-CM compared to the 50% group. It can be concluded that 12.5% WJMSCs-CM is the most efficient concentration for fibroblast proliferation.

Functional anatomy of the lateral collateral ligament of the elbow.

PubMed

Hackl, M; Bercher, M; Wegmann, K; Müller, L P; Dargel, J

2016-07-01

The aim of this study was to analyze the functional anatomy of the lateral collateral ligament complex (LCLC) and the surrounding forearm extensors. Using 81 human cadaveric upper extremities, the anatomy of the forearm extensors-especially the anconeus, supinator and extensor carpi ulnaris (ECU)-was analyzed. After removal of aforementioned extensors the functional anatomy of the LCLC was analyzed. The origin of the LCLC was evaluated for isometry. The insertion types of the lateral ulnar collateral ligament (LUCL) were analyzed and classified. The ECU runs parallel to the RCL to dynamically preserve varus stability. The supinator and anconeus muscle fibers coalesce with the LCLC and lengthen during pronation. The anconeus fibers run parallel to the LUCL in full flexion. The LCLC consists of the annular ligament (AL) and the isometric radial collateral ligament (RCL). During elbow flexion, its posterior branches (LUCL) tighten while the anterior branches loosen. When performing a pivot shift test, the loosened LUCL fibers do not fully tighten in full extension. The LUCL inserts along with the AL at the supinator crest. Three different insertion types could be observed. The LUCL represents the posterior branch of the RCL rather than a distinct ligament. It is non-isometric and lengthens during elbow flexion. The RCL was found to be of vital importance for neutralization of posterolateral rotatory forces. Pronation of the forearm actively stabilizes the elbow joint as the supinator, anconeus and biceps muscle work in unison to increase posterolateral rotatory stability.

Value of ultrasonography for detecting chronic injury of the lateral ligaments of the ankle joint compared with ultrasonography findings.

PubMed

Cheng, Y; Cai, Y; Wang, Y

2014-01-01

The aim of this study was to assess the accuracy of ultrasonography in the diagnosis of chronic lateral ankle ligament injury. A total of 120 ankles in 120 patients with a clinical suspicion of chronic ankle ligament injury were examined by ultrasonography by using a 5- to 17-MHz linear array transducer before surgery. The results of ultrasonography were compared with the operative findings. There were 18 sprains and 24 partial and 52 complete tears of the anterior talofibular ligament (ATFL); 26 sprains, 27 partial and 12 complete tears of the calcaneofibular ligament (CFL); and 1 complete tear of the posterior talofibular ligament (PTFL) at arthroscopy and operation. Compared with operative findings, the sensitivity, specificity and accuracy of ultrasonography were 98.9%, 96.2% and 84.2%, respectively, for injury of the ATFL and 93.8%, 90.9% and 83.3%, respectively, for injury of the CFL. The PTFL tear was identified by ultrasonography. The accuracy of identification between acute-on-chronic and subacute-chronic patients did not differ. The accuracies of diagnosing three grades of ATFL injuries were almost the same as those of diagnosing CFL injuries. Ultrasonography provides useful information for the evaluation of patients presenting with chronic pain after ankle sprain. Intraoperative findings are the reference standard. We demonstrated that ultrasonography was highly sensitive and specific in detecting chronic lateral ligments injury of the ankle joint.

Value of ultrasonography for detecting chronic injury of the lateral ligaments of the ankle joint compared with ultrasonography findings

PubMed Central

Cheng, Y; Cai, Y

2014-01-01

Objective: The aim of this study was to assess the accuracy of ultrasonography in the diagnosis of chronic lateral ankle ligament injury. Methods: A total of 120 ankles in 120 patients with a clinical suspicion of chronic ankle ligament injury were examined by ultrasonography by using a 5- to 17-MHz linear array transducer before surgery. The results of ultrasonography were compared with the operative findings. Results: There were 18 sprains and 24 partial and 52 complete tears of the anterior talofibular ligament (ATFL); 26 sprains, 27 partial and 12 complete tears of the calcaneofibular ligament (CFL); and 1 complete tear of the posterior talofibular ligament (PTFL) at arthroscopy and operation. Compared with operative findings, the sensitivity, specificity and accuracy of ultrasonography were 98.9%, 96.2% and 84.2%, respectively, for injury of the ATFL and 93.8%, 90.9% and 83.3%, respectively, for injury of the CFL. The PTFL tear was identified by ultrasonography. The accuracy of identification between acute-on-chronic and subacute–chronic patients did not differ. The accuracies of diagnosing three grades of ATFL injuries were almost the same as those of diagnosing CFL injuries. Conclusion: Ultrasonography provides useful information for the evaluation of patients presenting with chronic pain after ankle sprain. Advances in knowledge: Intraoperative findings are the reference standard. We demonstrated that ultrasonography was highly sensitive and specific in detecting chronic lateral ligments injury of the ankle joint. PMID:24352708

Variability in attachment of the coracoacromial ligament in relation with its morphology.

PubMed

Alraddadi, Abdulrahman; Alashkham, Abduelmenem; Lamb, Clare; Soames, Roger

2017-12-01

The coracoacromial ligament (CAL) presents with variable morphology and plays a significant role in the development of subacromial impingement syndrome. Sectioning the CAL has been suggested to relieve impingement of the rotator cuff. The aim of the current study was to investigate the CAL attachment in relation with ligament morphology. The CAL was investigated in 220 cadaveric shoulders from 58 males and 59 females, with a median age of 82 years (range 53-102 years). CALs were classified according to three factors: (1) number of bands present; (2) shape; and (3) attachment to the acromial and coracoid processes. 35 (16%) CALs had a single band, 84 (38%) two bands, and 101 (46%) three or more bands. CAL shape was either broadband (14: 6%), quadrangular (21: 10%), Y-shaped (84: 38%), or multiple-banded (101: 46%). More ligaments were attached to the medial aspect of the acromion (60%) and medial end of the coracoid (75%) than those restricted to the anterior edge of the acromion (40%) and posterior aspect of the coracoid (25%). Multiple-banded ligaments attached significantly more medially at the acromion and coracoid processes, while single band ligament attachments were restricted to the anterior edge of the acromion and posterior aspect of the coracoid process. The CAL has variable morphology and attachments with interconnections to different structures around the shoulder. CALs with a medial acromial attachment may narrow the subacromial space leading to further shoulder impingement.

The improvement of postural control in patients with mechanical ankle instability after lateral ankle ligaments reconstruction.

PubMed

Li, Hong-Yun; Zheng, Jie-Jiao; Zhang, Jian; Cai, Ye-Hua; Hua, Ying-Hui; Chen, Shi-Yi

2016-04-01

Lateral ankle sprain is the most common injury. A previous study demonstrated that patients with mechanical ankle instability suffered deficits in postural control, indicating that structural damage of the lateral ankle ligaments may produce a balance deficit. The purpose of this study was to confirm that lateral ligaments reconstruction could improve postural control in patients with mechanical ankle instability. A total of 15 patients were included in the study. Each patient had a history of an ankle sprain with persistent symptoms of ankle instability and a positive anterior drawer test and had been treated nonoperatively for at least 3 months. All patients were diagnosed with lateral ankle ligaments tear by ultrasonography and magnetic resonance imaging. They underwent arthroscopic debridement and open lateral ankle ligaments reconstruction with a modified Broström procedure. One day before and 6 months after the operation, all of the participants underwent single-limb postural sway tests. The anterior drawer test and the American Orthopedic Foot and Ankle Society scale score were used to evaluate the clinical results in these patients. At 6 months after the operation, with the patients' eyes closed, there was significantly decreased postural sway in the anteroposterior direction, the circumferential area, and the total path length on the operated ankles compared with those measurements before the operation. With eyes open, however, no difference was found in postural sway before and after the operation. Postural control was improved by reconstructing the lateral ligaments. IV.

Anatomy of the ankle ligaments: a pictorial essay

PubMed Central

Vega, Jordi; de Leeuw, Peter A. J.; Malagelada, Francesc; Manzanares, M. Cristina; Götzens, Víctor; van Dijk, C. Niek

2010-01-01

Understanding the anatomy of the ankle ligaments is important for correct diagnosis and treatment. Ankle ligament injury is the most frequent cause of acute ankle pain. Chronic ankle pain often finds its cause in laxity of one of the ankle ligaments. In this pictorial essay, the ligaments around the ankle are grouped, depending on their anatomic orientation, and each of the ankle ligaments is discussed in detail. PMID:20309522

Spatiotemporally Controlled Microchannels of Periodontal Mimic Scaffolds

PubMed Central

Park, C.H.; Kim, K.H.; Rios, H.F.; Lee, Y.M.; Giannobile, W.V.; Seol, Y.J.

2014-01-01

Physiologic bioengineering of the oral, dental, and craniofacial complex requires optimized geometric organizations of fibrous connective tissues. A computer-designed, fiber-guiding scaffold has been developed to promote tooth-supporting periodontal tissue regeneration and functional restoration despite limited printing resolution for the manufacture of submicron-scaled features. Here, we demonstrate the use of directional freeze-casting techniques to control pore directional angulations and create mimicked topographies to alveolar crest, horizontal, oblique, and apical fibers of natural periodontal ligaments. For the differing anatomic positions, the gelatin displayed varying patterns of ice growth, determined via internal pore architectures. Regardless of the freezing coordinates, the longitudinal pore arrangements resulted in submicron-scaled diameters (~50 µm), along with corresponding high biomaterial porosity (~90%). Furthermore, the horizontal + coronal ((x→−y→) freezing orientation facilitated the creation of similar structures to major fibers in the periodontal ligament interface. This periodontal tissue-mimicking microenvironment is a potential tissue platform for the generation of naturally oriented ligamentous tissues consistent with periodontal ligament neogenesis. PMID:25216511

Effect of Microstructural Parameters on the Relative Densities of Metal Foams

NASA Technical Reports Server (NTRS)

Raj, S. V.; Kerr, Jacob A.

2010-01-01

A detailed quantitative microstructural analyses of primarily open cell FeCrAlY and 314 stainless steel metal foams with different relative densities and pores per inch (p.p.i.) were undertaken in the present investigation to determine the effect of microstructural parameters on the relative densities of metal foams. Several elements of the microstructure, such as longitudinal and transverse cell sizes, cell areas and perimeters, ligament dimensions, cell shapes and volume fractions of closed and open cells, were measured. The cross-sections of the foam ligaments showed a large number of shrinkage cavities, and their circularity factors and average sizes were determined. The volume fractions of closed cells increased linearly with increasing relative density. In contrast, the volume fractions of the open cells and ligaments decreased with increasing relative density. The relative densities and p.p.i. were not significantly dependent on cell size, cell perimeter and ligament dimensions within the limits of experimental scatter. A phenomenological model is proposed to rationalize the present microstructural observations.

The effect of platelet-derived growth factors on knee stability after anterior cruciate ligament reconstruction: a prospective randomized clinical study.

PubMed

Vogrin, Matjaz; Rupreht, Mitja; Crnjac, Anton; Dinevski, Dejan; Krajnc, Zmago; Recnik, Gregor

2010-05-01

Arthroscopic reconstruction is a standard surgical procedure in cases of symptomatic knee instability due to rupture of the anterior cruciate ligament. Bone-tendon-bone and hamstring tendon grafts are both in use for anterior cruciate ligament reconstruction. There are no significant differences between the two types of graft in relation to function scores, but there is a difference in anteroposterior stability when measured on the KT-2000 arthrometer: knee joints after reconstruction with bone-tendon-bone autografts are more stable than those reconstructed with hamstring tendon autografts. To improve knee stability after anterior cruciate ligament reconstruction with a hamstring graft and use of platelet-derived growth factors. Platelet-leukocyte gel was produced from platelet-leukocyte-rich plasma prepared from a unit of whole blood in an autologous platelet separator. The gel was applied locally, after hamstring graft placement. Fifty patients were included in the study: 25 in the platelet gel group, 25 in a control group. We evaluated anteroposterior knee stability with the KT-2000 arthrometer before surgery and at 3 and 6 months after surgery. Patients treated with the gel demonstrated significantly better anteroposterior knee stability than patients in the control group. The calculated improvements in knee stability at 6 months were 1.3 +/- 1.8 mm in the control group and 3.1 +/- 2.5 mm in the platelet gel group (P = 0.011). Platelet-leukocyte gel, applied locally, can improve knee stability in surgery for reconstruction of the anterior cruciate ligament.

Ankle ligament healing after an acute ankle sprain: an evidence-based approach.

PubMed

Hubbard, Tricia J; Hicks-Little, Charlie A

2008-01-01

To perform a systematic review to determine the healing time of the lateral ankle ligaments after an acute ankle sprain. We identified English-language research studies from 1964 to 2007 by searching MEDLINE, Physiotherapy Evidence Database (PEDro), SportDiscus, and CINAHL using the terms ankle sprain, ankle rehabilitation, ankle injury, ligament healing, and immobilization. We selected studies that described randomized, controlled clinical trials measuring ligament laxity either objectively or subjectively immediately after injury and at least 1 more time after injury. Two reviewers independently scored the 7 studies that met the inclusion criteria. Because of differences in study designs, a meta-analysis could not be performed. Effect sizes and confidence intervals could be calculated only for 1 study. The percentages of subjective and objective instability were calculated for the remaining studies. Ankle laxity improved over a period of 6 weeks to 1 year. One author showed stress talar tilt values of 16.10 +/- 8.8 degrees immediately after injury and 3.4 +/- 3.6 degrees at 3 months after injury. In 2 articles, the authors reported that positive anterior drawer tests were still present in 3% to 31% of participants at 6 months after injury. Additionally, feelings of instability affected 7% to 42% of participants up to 1 year after injury. In the studies that we examined, it took at least 6 weeks to 3 months before ligament healing occurred. However, at 6 weeks to 1 year after injury, a large percentage of participants still had objective mechanical laxity and subjective ankle instability. Direct comparison among articles is difficult because of differences in methods. More research focusing on more reliable methods of measuring ankle laxity is needed so that clinicians can know how long ligament healing takes after injury. This knowledge will help clinicians to make better decisions during rehabilitation and for return to play.

Interactions between COL5A1 Gene and Risk of the Anterior Cruciate Ligament Rupture.

PubMed

Lulińska-Kuklik, Ewelina; Rahim, Masouda; Domańska-Senderowska, Daria; Ficek, Krzysztof; Michałowska-Sawczyn, Monika; Moska, Waldemar; Kaczmarczyk, Mariusz; Brzeziański, Michał; Brzeziańska-Lasota, Ewa; Cięszczyk, Paweł; September, Alison V

2018-06-01

Collagen alpha-1(V) chain, encoded by the COL5A1 gene, plays a crucial role in abundant fibrillar collagens supporting many tissues in the body containing type I collagen and appears to regulate the association between heterotypic fibers composed of both type I and type V collagen occurring among others in muscles, tendons and ligaments. Taking this fact into consideration we decided to examine the association between COL5A1 rs12722 and rs13946 polymorphisms, individually and as inferred haplotypes, with anterior cruciate ligament rupture risk (ACLR) in professional soccer players. A total of 134 male professional soccer players with surgically diagnosed primary anterior cruciate ligament ruptures and 211 apparently healthy male professional soccer players, who were without any self-reported history of ligament or tendon injury, were included in the study. Both the cases and the healthy controls were recruited from the same soccer teams, of a similar age category, and had a comparable level of exposure to anterior cruciate ligament injury. Genomic DNA was extracted from oral epithelial cells using GenElute Mammalian Genomic DNA MiniprepKit. All samples were genotyped for the rs12722 and rs13946 polymorphisms using a Rotor-Gene realtime polymerase chain reaction. Statistically significant differences in the genotype frequencies for the COL5A1 rs13946 polymorphisms in dominant modes of inheritance occurred (p = 0.039). Statistically significant differences were documented only in the dominant model under the representation tendency of the C-C haplotype in the ACLR group compared to controls (p = 0.038). Our results suggest that variation in the COL5A1 gene may be one of the non-modifiable factors associated with the ACL injury in professional soccer players. The C-C rs12722-rs13946 haplotype provides a protective effect against the ACL tear.

A History of Anterior Cruciate Ligament Reconstruction at the National Football League Combine Results in Inferior Early National Football League Career Participation.

PubMed

Provencher, Matthew T; Bradley, James P; Chahla, Jorge; Sanchez, Anthony; Beaulieu-Jones, Brendin R; Arner, Justin W; Kennedy, Nicholas I; Sanchez, George; Kennedy, Mitchell I; Moatshe, Gilbert; Cinque, Mark E; LaPrade, Robert F

2018-05-19

To evaluate whether players with a history of an anterior cruciate ligament reconstruction (ACLR) before the National Football League (NFL) Combine played or started fewer games and/or participated in fewer eligible snaps compared with NFL Combine participants without a history of knee injury or surgery. We performed a retrospective review of all players who participated in the NFL Combine between 2009 and 2015 and who had a history of an ACLR. NFL Combine participants were included if they had a previous ACLR or combined anterior cruciate ligament (ACL) injury and nonoperatively managed medial collateral ligament injury. The number of games started, number of games played, draft number, overall draft pick, and snap percentage for each position were determined. The mean value of each outcome metric was compared between case and control players. We identified 110 players who had an ACL injury (n = 76) or a combined ACL and medial collateral ligament injury (n = 34). Players in the ACLR group had a significantly worse mean draft pick number (difference of 30.2, P = .002) and mean draft round (difference of 0.8, P = .019) versus controls. Compared with control players, players in the ACLR group started and played significantly fewer games in both season 1 (difference of 2.7 games started, P < .001; difference of 2.7 games played, P < .001) and season 2 (difference of 7.4 games started, P < .001; difference of 3.0 games played, P = .003) and had a significantly lower snap percentage in both season 1 (difference of 23.1%, P < .001) and season 2 (difference of 24.0%, P < .001). Athletes at the NFL Combine who previously underwent an ACLR had significantly lower early-career NFL player metrics, including fewer games started, fewer games played, and a lower snap percentage, than uninjured controls. Defensive linemen, defensive backs, and linebackers were the 3 most affected positions. Players with a prior ACLR and combined meniscal-chondral pathology had significantly lower numbers of games started and games played in seasons 1 and 2 and a significantly lower season 2 snap percentage. Level III, case-control study. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

[Prevention and repair of patellar ligament injury in total knee arthroplasty].

PubMed

Bian, Yanyan; Weng, Xisheng

2013-09-01

To review the progress in the prevention and repair of patellar ligament injury in total knee Recent literature about the prevention and repair of patellar ligament injury in total knee arthroplasty arthroplasty. was reviewed and analyzed. Increased exposure can prevent the patellar ligament injury, and treatments of acute patellar ligament rupture can be obtained by simple repair, reconstruction with allograft materials or artificial materials, and auxiliary strengthening. Patellar ligament injury in total knee arthroplasty should not be ignored. Active prevention and repair of patellar ligament injury can obtain better function of knee joint.

Biomechanical implications of lumbar spinal ligament transection.

PubMed

Von Forell, Gregory A; Bowden, Anton E

2014-11-01

Many lumbar spine surgeries either intentionally or inadvertently damage or transect spinal ligaments. The purpose of this work was to quantify the previously unknown biomechanical consequences of isolated spinal ligament transection on the remaining spinal ligaments (stress transfer), vertebrae (bone remodelling stimulus) and intervertebral discs (disc pressure) of the lumbar spine. A finite element model of the full lumbar spine was developed and validated against experimental data and tested in the primary modes of spinal motion in the intact condition. Once a ligament was removed, stress increased in the remaining spinal ligaments and changes occurred in vertebral strain energy, but disc pressure remained similar. All major biomechanical changes occurred at the same spinal level as the transected ligament, with minor changes at adjacent levels. This work demonstrates that iatrogenic damage to spinal ligaments disturbs the load sharing within the spinal ligament network and may induce significant clinically relevant changes in the spinal motion segment.

An attachment-based description of the medial collateral and spring ligament complexes.

PubMed

Cromeens, Barrett P; Kirchhoff, Claire A; Patterson, Rita M; Motley, Travis; Stewart, Donald; Fisher, Cara; Reeves, Rustin E

2015-06-01

Anatomy of the medial collateral and spring ligament complexes has been the cause of confusion. The anatomic description is highly dependent on the source studied and little agreement exists between texts. In addition, inconsistent nomenclature has been used to describe the components. This study attempted to clarify confusion through the creation of a 3D ligament map using attachment-based dissection. Nine fresh foot and ankle specimens were observed. The medial collateral ligament and spring ligament complexes were dissected using their attachment sites as a guide to define individual components. Each component's perimeter and thickness was measured and each bony attachment was mapped using a microscribe 3D digitizer. Five components were identified contributing to the ligament complexes of interest: the tibiocalcaneonavicular, superficial posterior tibiotalar, deep posterior tibiotalar, deep anterior tibiotalar, and inferoplantar longitudinal ligaments. The largest component by total attachment area was the tibiocalcaneonavicular ligament followed by the deep posterior tibiotalar ligament. The largest ligament surface area of attachment to the tibia and talus was the deep posterior tibiotalar ligament. The largest attachment to the navicular and calcaneus was the tibiocalcaneonavicular ligament, which appeared to function in holding these bones in proximity while supporting the head of the talus. By defining complex components by their attachment sites, a novel, more functional and reproducible description of the medial collateral and spring ligament complexes was created. The linear measurements and 3D maps may prove useful when attempting more anatomically accurate reconstructions. © The Author(s) 2015.

Medial collateral ligament injuries and subsequent load on the anterior cruciate ligament: a biomechanical evaluation in a cadaveric model.

PubMed

Battaglia, Michael J; Lenhoff, Mark W; Ehteshami, John R; Lyman, Stephen; Provencher, Matthew T; Wickiewicz, Thomas L; Warren, Russell F

2009-02-01

Numerous studies have documented the effect of complete medial collateral ligament injury on anterior cruciate ligament loads; few have addressed how partial medial collateral ligament disruption affects knee kinematics. To determine knee kinematics and subsequent change in anterior cruciate ligament load in a partial and complete medial collateral ligament injury model. Controlled laboratory study. Ten human cadaveric knees were sequentially tested by a robot with the medial collateral ligament intact, in a partial injury model, and in a complete injury model with a universal force-moment sensor measuring system. Tibial translation, rotation, and anterior cruciate ligament load were measured under 3 conditions: anterior load (125 N), valgus load (10 N x m), and internal-external rotation torque (4 N x m; all at 0 degrees and 30 degrees of flexion). Anterior and posterior translation did not statistically increase with a partial or complete medial collateral ligament injury at 0 degrees and 30 degrees of flexion. In response to a 125 N anterior load, at 0 degrees , the anterior cruciate ligament load increased 8.7% (from 99.5 to 108.2 N; P = .006) in the partial injury and 18.3% (117.7 N; P < .001) in the complete injury; at 30 degrees , anterior cruciate ligament load was increased 12.3% (from 101.7 to 114.2 N; P = .001) in the partial injury and 20.6% (122.7 N; P < .001) in the complete injury. In response to valgus torque (10 N x m) at 30 degrees , anterior cruciate ligament load was increased 55.3% (30.4 to 47.2 N; P = .044) in the partial injury model and 185% (86.8 N; P = .001) in the complete injury model. In response to internal rotation torque (4 N.m) at 30 degrees , anterior cruciate ligament load was increased 29.3% (27.6 to 35.7 N; P = .001) in the partial injury model and 65.2% (45.6 N; P < .001) in the complete injury model. The amount of internal rotation at 30 degrees of flexion was significantly increased in the complete injury model (22.8 degrees ) versus the intact state (19.5 degrees ; P < .001). Partial and complete medial collateral ligament tears significantly increased the load on the anterior cruciate ligament. In a partial tear, the resultant load on the anterior cruciate ligament was increased at 30 degrees of flexion and with valgus load and internal rotation torque. Patients may need to be protected from valgus and internal rotation forces after anterior cruciate ligament reconstruction in the setting of a concomitant partial medial collateral ligament tear. This information may help clinicians understand the importance of partial injuries of the medial collateral ligament with a combined anterior cruciate ligament injury complex.

A co-culture system with three different primary human cell populations reveals that biomaterials and MSC modulate macrophage-driven fibroblast recruitment.

PubMed

Caires, Hugo R; Barros da Silva, Patrícia; Barbosa, Mário A; Almeida, Catarina R

2018-03-01

The biological response to implanted biomaterials is a complex and highly coordinated phenomenon involving many different cell types that interact within 3D microenvironments. Here, we increased the complexity of a 3D platform to include at least 3 cell types that play a role in the host response upon scaffold implantation. With this system, it was possible to address how immune responses triggered by 3D biomaterials mediate recruitment of stromal cells that promote tissue regeneration, mesenchymal stromal/stem cells (MSC), or a foreign body response, fibroblasts. Primary human macrophages yielded the highest fibroblast recruitment when interacting with chitosan scaffolds but not polylactic acid. Interestingly, when there were MSC and fibroblasts in the same environment, macrophages in chitosan scaffolds again promoted a significant increase on fibroblast recruitment, but not of MSC. However, macrophages that were firstly allowed to interact with MSC within the scaffolds were no longer able to recruit fibroblasts. This study illustrates the potential to use different scaffolds to regulate the dynamics of recruitment of proregenerative or fibrotic cell types through immunomodulation. Overall, this work strengths the idea that ex vivo predictive systems need to consider the different players involved in the biological response to biomaterials and that timing of arrival of specific cell types will affect the outcome. Copyright © 2017 John Wiley & Sons, Ltd.

Rotational and translational stability of different methods for direct acromioclavicular ligament repair in anatomic acromioclavicular joint reconstruction.

PubMed

Beitzel, Knut; Obopilwe, Elifho; Apostolakos, John; Cote, Mark P; Russell, Ryan P; Charette, Ryan; Singh, Hardeep; Arciero, Robert A; Imhoff, Andreas B; Mazzocca, Augustus D

2014-09-01

Many reconstructions of acromioclavicular (AC) joint dislocations have focused on the coracoclavicular (CC) ligaments and neglected the functional contribution of the AC ligaments and the deltotrapezial fascia. To compare the modifications of previously published methods for direct AC reconstruction in addition to a CC reconstruction. The hypothesis was that there would be significant differences within the variations of surgical reconstructions. Controlled laboratory study. A total of 24 cadaveric shoulders were tested with a servohydraulic testing system. Two digitizing cameras evaluated the 3-dimensional movement. All reconstructions were based on a CC reconstruction using 2 clavicle tunnels and a tendon graft. The following techniques were used to reconstruct the AC ligaments: a graft was shuttled underneath the AC joint back from anterior and again sutured to the acromial side of the joint (group 1), a graft was fixed intramedullary in the acromion and distal clavicle (group 2), a graft was passed over the acromion and into an acromial tunnel (group 3), and a FiberTape was fixed in a cruciate configuration (group 4). Anterior, posterior, and superior translation, as well as anterior and posterior rotation, were tested. Group 1 showed significantly less posterior translation compared with the 3 other groups (P < .05) but did not show significant differences compared with the native joint. Groups 3 and 4 demonstrated significantly more posterior translation than the native joint. Group 1 showed significantly less anterior translation compared with groups 2 and 3. Group 3 demonstrated significantly more anterior translation than the native joint. Group 1 demonstrated significantly less superior translation compared with the other groups and with the native joint. The AC joint of group 1 was pulled apart less compared with all other reconstructions. Only group 1 reproduced the native joint for the anterior rotation at the posterior marker. Group 4 showed significantly increased distances for all 3 measure points when the clavicle was rotated posteriorly. Reconstruction of the AC ligament by direct wrapping and suturing of the remaining graft around the AC joint (group 1) was the most stable method and was the only one to show anterior rotation comparable with the native joint. In contrast, the transacromial technique (group 3) showed the most translation and rotation. An anatomic repair should address both the CC ligaments and the AC ligaments to control the optimal physiologic function (translation and rotation). © 2014 The Author(s).

Development and validation of a computational model to study the effect of foot constraint on ankle injury due to external rotation.

PubMed

Wei, Feng; Hunley, Stanley C; Powell, John W; Haut, Roger C

2011-02-01

Recent studies, using two different manners of foot constraint, potted and taped, document altered failure characteristics in the human cadaver ankle under controlled external rotation of the foot. The posterior talofibular ligament (PTaFL) was commonly injured when the foot was constrained in potting material, while the frequency of deltoid ligament injury was higher for the taped foot. In this study an existing multibody computational modeling approach was validated to include the influence of foot constraint, determine the kinematics of the joint under external foot rotation, and consequently obtain strains in various ligaments. It was hypothesized that the location of ankle injury due to excessive levels of external foot rotation is a function of foot constraint. The results from this model simulation supported this hypothesis and helped to explain the mechanisms of injury in the cadaver experiments. An excessive external foot rotation might generate a PTaFL injury for a rigid foot constraint, and an anterior deltoid ligament injury for a pliant foot constraint. The computational models may be further developed and modified to simulate the human response for different shoe designs, as well as on various athletic shoe-surface interfaces, so as to provide a computational basis for optimizing athletic performance with minimal injury risk.

Atlas Fractures and Atlas Osteosynthesis: A Comprehensive Narrative Review.

PubMed

Kandziora, Frank; Chapman, Jens R; Vaccaro, Alexander R; Schroeder, Gregory D; Scholz, Matti

2017-09-01

Most atlas fractures are the result of compression forces. They are often combined with fractures of the axis and especially with the odontoid process. Multiple classification systems for atlas fractures have been described. For an adequate diagnosis, a computed tomography is mandatory. To distinguish between stable and unstable atlas injury, it is necessary to evaluate the integrity of the transverse atlantal ligament (TAL) by magnetic resonance imaging and to classify the TAL lesion. Studies comparing conservative and operative management of unstable atlas fractures are unfortunately not available in the literature; neither are studies comparing different operative treatment strategies. Hence all treatment recommendations are based on low level evidence. Most of atlas fractures are stable and will be successfully managed by immobilization in a soft/hard collar. Unstable atlas fractures may be treated conservatively by halo-fixation, but nowadays more and more surgeons prefer surgery because of the potential discomfort and complications of halo-traction. Atlas fractures with a midsubstance ligamentous disruption of TAL or severe bony ligamentous avulsion can be treated by a C1/2 fusion. Unstable atlas fractures with moderate bony ligamentous avulsion may be treated by atlas osteosynthesis. Although the evidence for the different treatment strategies of atlas fractures is low, atlas osteosynthesis has the potential to change treatment philosophies. The reasons for this are described in this review.

Cell plasticity in wound healing: paracrine factors of M1/ M2 polarized macrophages influence the phenotypical state of dermal fibroblasts

PubMed Central

2013-01-01

Background Macrophages and fibroblasts are two major players in tissue repair and fibrosis. Despite the relevance of macrophages and fibroblasts in tissue homeostasis, remarkably little is known whether macrophages are able to influence the properties of fibroblasts. Here we investigated the role of paracrine factors secreted by classically activated (M1) and alternatively activated (M2) human macrophages on human dermal fibroblasts (HDFs). Results HDFs stimulated with paracrine factors from M1 macrophages showed a 10 to > 100-fold increase in the expression of the inflammatory cytokines IL6, CCL2 and CCL7 and the matrix metalloproteinases MMP1 and MMP3. This indicates that factors produced by M1 macrophages induce a fibroblast phenotype with pro-inflammatory and extracellular matrix (ECM) degrading properties. HDFs stimulated with paracrine factors secreted by M2 macrophages displayed an increased proliferation rate. Interestingly, the M1-activated pro-inflammatory fibroblasts downregulated, after exposure to paracrine factors produced by M2 macrophages or non-conditioned media, the inflammatory markers as well as MMPs and upregulated their collagen production. Conclusions Paracrine factors of M1 or M2 polarized macrophages induced different phenotypes of HDFs and the HDF phenotypes can in turn be reversed, pointing to a high dynamic plasticity of fibroblasts in the different phases of tissue repair. PMID:23601247

Enhanced Keratinocyte Proliferation and Migration in Co-culture with Fibroblasts

PubMed Central

Wang, Zhenxiang; Wang, Ying; Farhangfar, Farhang; Zimmer, Monica; Zhang, Yongxin

2012-01-01

Wound healing is primarily controlled by the proliferation and migration of keratinocytes and fibroblasts as well as the complex interactions between these two cell types. To investigate the interactions between keratinocytes and fibroblasts and the effects of direct cell-to-cell contact on the proliferation and migration of keratinocytes, keratinocytes and fibroblasts were stained with different fluorescence dyes and co-cultured with or without transwells. During the early stage (first 5 days) of the culture, the keratinocytes in contact with fibroblasts proliferated significantly faster than those not in contact with fibroblasts, but in the late stage (11th to 15th day), keratinocyte growth slowed down in all cultures unless EGF was added. In addition, keratinocyte migration was enhanced in co-cultures with fibroblasts in direct contact, but not in the transwells. Furthermore, the effects of the fibroblasts on keratinocyte migration and growth at early culture stage correlated with heparin-binding EGF-like growth factor (HB-EGF), IL-1α and TGF-β1 levels in the cultures where the cells were grown in direct contact. These effects were inhibited by anti-HB-EGF, anti-IL-1α and anti-TGF-β1 antibodies and anti-HB-EGF showed the greatest inhibition. Co-culture of keratinocytes and IL-1α and TGF-β1 siRNA-transfected fibroblasts exhibited a significant reduction in HB-EGF production and keratinocyte proliferation. These results suggest that contact with fibroblasts stimulates the migration and proliferation of keratinocytes during wound healing, and that HB-EGF plays a central role in this process and can be up-regulated by IL-1α and TGF-β1, which also regulate keratinocyte proliferation differently during the early and late stage. PMID:22911722

Effects of different feeder layers on culture of bovine embryonic stem cell-like cells in vitro.

PubMed

Cong, Shan; Cao, Guifang; Liu, Dongjun

2014-12-01

To find a suitable feeder layer is important for successful culture conditions of bovine embryonic stem cell-like cells. In this study, expression of pluripotency-related genes OCT4, SOX2 and NANOG in bovine embryonic stem cell-like cells on mouse embryonic fibroblast feeder layers at 1-5 passages were monitored in order to identify the possible reason that bovine embryonic stem cell-like cells could not continue growth and passage. Here, we developed two novel feeder layers, mixed embryonic fibroblast feeder layers of mouse and bovine embryonic fibroblast at different ratios and sources including mouse fibroblast cell lines. The bovine embryonic stem cell-like cells generated in our study displayed typical stem cell morphology and expressed specific markers such as OCT4, stage-specific embryonic antigen 1 and 4, alkaline phosphatase, SOX2, and NANOG mRNA levels. When feeder layers and cell growth factors were removed, the bovine embryonic stem cell-like cells formed embryoid bodies in a suspension culture. Furthermore, we compared the expression of the pluripotent markers during bovine embryonic stem cell-like cell in culture on mixed embryonic fibroblast feeder layers, including mouse fibroblast cell lines feeder layers and mouse embryonic fibroblast feeder layers by real-time quantitative polymerase chain reaction. Results suggested that mixed embryonic fibroblast and sources including mouse fibroblast cell lines feeder layers were more suitable for long-term culture and growth of bovine embryonic stem cell-like cells than mouse embryonic fibroblast feeder layers. The findings may provide useful experimental data for the establishment of an appropriate culture system for bovine embryonic stem cell lines.

Anatomic deltoid ligament repair with anchor-to-post suture reinforcement: technique tip.

PubMed

Lack, William; Phisitkul, Phinit; Femino, John E

2012-01-01

The deltoid ligament is the primary ligamentous stabilizer of the ankle joint. Both superficial and deep components of the ligament can be disrupted with a rotational ankle fracture, chronic ankle instability, or in late stage adult acquired flatfoot deformity. The role of deltoid ligament repair in these conditions has been limited and its contribution to arthritis is largely unknown. Neglect of the deltoid ligament in the treatment of ankle injuries may be due to difficulties in diagnosis and lack of an effective method for repair. Most acute repair techniques address the superficial deltoid ligament with direct end-to-end repair, fixation through bone tunnels, or suture anchor repair of avulsion injuries. Deep deltoid ligament repair has been described using direct end-to-end repair with sutures, as well as by autograft and allograft tendon reconstruction utilizing various techniques. Newer tenodesis techniques have been described for late reconstruction of both deep and superficial components in patients with stage 4 adult acquired flatfoot deformity. We describe a technique that provides anatomic ligament-to-bone repair of the superficial and deep bundles of the deltoid ligament while reducing the talus toward the medial malleolar facet of the tibiotalar joint with anchor-to-post reinforcement of the ligamentous repair. This technique may protect and allow the horizontally oriented fibers of the deep deltoid ligament to heal with the appropriate resting length while providing immediate stability of the construct.

A two-layer composite model of the vocal fold lamina propria for fundamental frequency regulation.

PubMed

Zhang, Kai; Siegmund, Thomas; Chan, Roger W

2007-08-01

The mechanical properties of the vocal fold lamina propria, including the vocal fold cover and the vocal ligament, play an important role in regulating the fundamental frequency of human phonation. This study examines the equilibrium hyperelastic tensile deformation behavior of cover and ligament specimens isolated from excised human larynges. Ogden's hyperelastic model is used to characterize the tensile stress-stretch behaviors at equilibrium. Several statistically significant differences in the mechanical response differentiating cover and ligament, as well as gender are found. Fundamental frequencies are predicted from a string model and a beam model, both accounting for the cover and the ligament. The beam model predicts nonzero F(0) for the unstretched state of the vocal fold. It is demonstrated that bending stiffness significantly contributes to the predicted F(0), with the ligament contributing to a higher F(0), especially in females. Despite the availability of only a small data set, the model predicts an age dependence of F(0) in males in agreement with experimental findings. Accounting for two mechanisms of fundamental frequency regulation--vocal fold posturing (stretching) and extended clamping--brings predicted F(0) close to the lower bound of the human phonatory range. Advantages and limitations of the current model are discussed.

Fixation and detachment of superior and anterior malleolar ligaments in human middle ear: Experiment and modeling

PubMed Central

Dai, Chenkai; Cheng, Tao; Wood, Mark W.; Gan, Rong Z.

2007-01-01

The aim of this study is to investigate the function of the superior malleolar ligament (SML) and the anterior malleolar ligament (AML) in human middle ear for sound transmission through simulations of fixation and detachment of these ligaments in human temporal bones and a finite element (FE) ear model. Two laser vibrometers were used to measure the vibrations of the tympanic membrane (TM) and stapes footplate. A 3-D FE ear model was used to predict the transfer function of the middle ear with ligament fixation and detachment. The results demonstrate that fixations and detachments of the SML and AML had different effects on TM and stapes footplate movements. Fixation of the SML resulted in a reduction of displacement of the TM (umbo) and the footplate at low frequencies (f < 1000 Hz), but also caused a shift of displacement peak to higher frequencies. Fixation of both SML and AML caused a reduction of 15 dB at umbo or stapes at low frequencies. Detachment of the SML had almost no effect on TM and footplate mobility, but AML detachment had a minor effect on TM and footplate movement. The FE model was able to predict the effects of SML and AML fixation and detachment. PMID:17517484

Electron Beam Sterilization Does Not Have a Detrimental Effect on the Ability of Extracellular Matrix Scaffolds to Support In Vivo Ligament Healing

PubMed Central

Proffen, Benedikt L.; Perrone, Gabriel S.; Fleming, Braden C.; Sieker, Jakob T.; Kramer, Joshua; Hawes, Michael L.; Badger, Gary J.; Murray, Martha M.

2015-01-01

Purpose Extra-cellular matrix (ECM) scaffolds have been used to enhance anterior cruciate ligament (ACL) repair in large animal models. To translate this technology to clinical care, identifying a method, which effectively sterilizes the material without significantly impairing in vivo function, is desirable. Methods 16 Yorkshire pigs underwent ACL transection and were randomly assigned to bridge-enhanced ACL repair – primary suture repair of the ACL with addition of autologous blood soaked ECM scaffold - with either 1) an aseptically processed ECM scaffold, or 2) an electron beam irradiated ECM scaffold. Primary outcome measures included sterility of the scaffold and biomechanical properties of the scaffold itself and the repaired ligament at eight weeks after surgery. Results Scaffolds treated with 15kGy electron beam irradiation had no bacterial or fungal growth noted, while aseptically processed scaffolds had bacterial growth in all tested samples. The mean biomechanical properties of the scaffold and healing ligament were lower in the electron beam group; however, differences were not statistically significant. Conclusions Electron beam irradiation was able to effectively sterilize the scaffolds. In addition, this technique had only a minimal impact on the in vivo function of the scaffolds when used for ligament healing in the porcine model. PMID:25676876

Interleukin-1β Attenuates Myofibroblast Formation and Extracellular Matrix Production in Dermal and Lung Fibroblasts Exposed to Transforming Growth Factor-β1

PubMed Central

Mia, Masum M.; Boersema, Miriam; Bank, Ruud A.

2014-01-01

One of the most potent pro-fibrotic cytokines is transforming growth factor (TGFβ). TGFβ is involved in the activation of fibroblasts into myofibroblasts, resulting in the hallmark of fibrosis: the pathological accumulation of collagen. Interleukin-1β (IL1β) can influence the severity of fibrosis, however much less is known about the direct effects on fibroblasts. Using lung and dermal fibroblasts, we have investigated the effects of IL1β, TGFβ1, and IL1β in combination with TGFβ1 on myofibroblast formation, collagen synthesis and collagen modification (including prolyl hydroxylase, lysyl hydroxylase and lysyl oxidase), and matrix metalloproteinases (MMPs). We found that IL1β alone has no obvious pro-fibrotic effect on fibroblasts. However, IL1β is able to inhibit the TGFβ1-induced myofibroblast formation as well as collagen synthesis. Glioma-associated oncogene homolog 1 (GLI1), the Hedgehog transcription factor that is involved in the transformation of fibroblasts into myofibroblasts is upregulated by TGFβ1. The addition of IL1β reduced the expression of GLI1 and thereby also indirectly inhibits myofibroblast formation. Other potentially anti-fibrotic effects of IL1β that were observed are the increased levels of MMP1, −2, −9 and −14 produced by fibroblasts exposed to TGFβ1/IL1β in comparison with fibroblasts exposed to TGFβ1 alone. In addition, IL1β decreased the TGFβ1-induced upregulation of lysyl oxidase, an enzyme involved in collagen cross-linking. Furthermore, we found that lung and dermal fibroblasts do not always behave identically towards IL1β. Suppression of COL1A1 by IL1β in the presence of TGFβ1 is more pronounced in lung fibroblasts compared to dermal fibroblasts, whereas a higher upregulation of MMP1 is seen in dermal fibroblasts. The role of IL1β in fibrosis should be reconsidered, and the differences in phenotypical properties of fibroblasts derived from different organs should be taken into account in future anti-fibrotic treatment regimes. PMID:24622053

Effects of laser immunotherapy on tumor microenvironment

NASA Astrophysics Data System (ADS)

Acquaviva, Joseph T.; Wood, Ethan W.; Hasanjee, Aamr; Chen, Wei R.; Vaughan, Melville B.

2014-02-01

The microenvironments of tumors are involved in a complex and reciprocal dialog with surrounding cancer cells. Any novel treatment must consider the impact of the therapy on the microenvironment. Recently, clinical trials with laser immunotherapy (LIT) have proven to effectively treat patients with late-stage, metastatic breast cancer and melanoma. LIT is the synergistic combination of phototherapy (laser irradiation) and immunological stimulation. One prominent cell type found in the tumor stroma is the fibroblast. Fibroblast cells can secrete different growth factors and extracellular matrix modifying molecules. Furthermore, fibroblast cells found in the tumor stroma often express alpha smooth muscle actin. These particular fibroblasts are coined cancer-associated fibroblast cells (CAFs). CAFs are known to facilitate the malignant progression of tumors. A collagen lattice assay with human fibroblast cells is used to elucidate the effects LIT has on the microenvironment of tumors. Changes in the contraction of the lattice, the differentiation of the fibroblast cells, as well as the proliferation of the fibroblast cells will be determined.

Inflammatory responses of stromal fibroblasts to inflammatory epithelial cells are involved in the pathogenesis of bovine mastitis.

PubMed

Zhang, Wenyao; Li, Xuezhong; Xu, Tong; Ma, Mengru; Zhang, Yong; Gao, Ming-Qing

2016-11-15

Hypernomic secretion of epithelial cytokines has several effects on stromal cells. The contributions of inflammatory epithelial cells to stromal fibroblasts in bovine mammary glands with mastitis remain poorly understood. Here, we established an inflammatory epithelial cell model of bovine mastitis with gram-negative lipopolysaccharide (LPS) and gram-positive lipoteichoic acid (LTA) bacterial cell wall components. We characterized immune responses of mammary stromal fibroblasts induced by inflammatory epithelial cells. Our results showed that inflammatory epithelial cells affected stromal fibroblast characteristics by increasing inflammatory mediator expression, elevating extracellular matrix protein deposition, decreasing proliferation capacity, and enhancing migration ability. The changes in stromal fibroblast proliferation and migration abilities were mediated by signal molecules, such as WNT signal pathway components. LPS- and LTA-induced inflammatory epithelial cells triggered different immune responses in stromal fibroblasts. Thus, in mastitis, bovine mammary gland stromal fibroblasts were affected by inflammatory epithelial cells and displayed inflammation-specific changes, suggesting that fibroblasts play crucial roles in bovine mastitis. Copyright © 2016 Elsevier Inc. All rights reserved.

Lipopolysaccharide-regulated production of bone sialoprotein and interleukin-8 in human periodontal ligament fibroblasts: the role of toll-like receptors 2 and 4 and the MAPK pathway.

PubMed

Zhang, Y; Li, X

2015-04-01

Lipopolysaccharide (LPS) on the cell wall of periodontal pathogens is a major mediator of the inflammatory response and can enhance alveolar bone resorption in periodontitis. Bone sialoprotein is an early marker of osteoblast differentiation. The proinflammatory cytokine, interleukin-8 (IL-8), induces osteoclast differentiation, maturation and maintenance of bone resorption activity. However, the effects of LPS from periodontal pathogens on the expression of bone sialoprotein and IL-8 in human osteoblasts and the mechanism of periodontal bone metabolism regulation are rather unclear. The objectives of this study were to determine the effects of Porphyromonas gingivalis LPS on the production of bone sialoprotein and IL-8 in human periodontal ligament fibroblasts (hPDLFs), and to investigate whether toll-like receptor (TLR) 2, TLR4 and MAPKs pathways are involved in the regulation of production of bone sialoprotein and IL-8 by P. gingivalis LPS. The third-generation of hPDLFs were cultured with mineralization-inducing culture medium. After hPDLFs were treated with P. gingivalis LPS, bone sialoprotein and IL-8 mRNA expression were detected using Real time PCR. Then hPDLFs were transiently transfected with siTLR2 or siTLR4 (20 nm) or inhibited by MAPK signaling pathways inhibitors, and then bone sialoprotein and IL-8 mRNA and protein expression were also detected using Real time PCR and western blotting. Treatments with 0.01 and 0.1 mg/L of P. gingivalis LPS for 8 h up-regulated bone sialoprotein mRNA expression, whereas 10 and 100 mg/L of P. gingivalis LPS induced a significant decrease in the expression of bone sialoprotein mRNA. In contrast, IL8 mRNA levels were increased significantly by 10 mg/L of P. gingivalis LPS. Interestingly, small interfering RNA (siRNA) knock down of the TLR2 and ERK1/2 inhibitor, PD98059, abolished the effects of P. gingivalis LPS on the bone sialoprotein mRNA level, whereas siRNA knock down of the TLR2 and p38 MAPK inhibitor, SB203580, blocked the effect of P. gingivalis LPS on IL-8 in hPDLFs. This study suggests that in hPDLFs, P. gingivalis LPS suppresses bone sialoprotein and enhances IL-8 gene and protein expression via TLR2 and ERK1/2 or the p38 MAPK signaling pathway, respectively. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Quantitative Structure-Cytotoxicity Relationship of Oleoylamides.

PubMed

Sakagami, Hiroshi; Uesawa, Yoshihiro; Ishihara, Mariko; Kagaya, Hajime; Kanamoto, Taisei; Terakubo, Shigemi; Nakashima, Hideki; Takao, Koichi; Sugita, Yoshiaki

2015-10-01

Eighteen oleoylamides were subjected to quantitative structure-activity relationship analysis based on their cytotoxicity, tumor selectivity and anti-HIV activity, in order to assess their biological activities. Cytotoxicity against four human oral squamous cell carcinoma (OSCC) cell lines and five human oral normal cells (gingival fibroblast, periodontal ligament fibroblast, pulp cell, oral keratinocyte, primary gingival epithelial cells) was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Tumor-selectivity (TS) was evaluated by the ratio of the mean 50% cytotoxic concentration (CC50) against normal human oral cells to that against OSCC cell lines. Potency-selectivity expression (PSE) was determined by the ratio of TS to CC50 against OSCC. Anti-HIV activity was evaluated by the ratio of CC50 to the concentration leading to 50% cytoprotection from HIV infection (EC50). Physicochemical, structural and quantum-chemical parameters were calculated based on the conformations optimized by the LowModeMD method. Among 18 derivatives, compounds 8: with a catechol group) and 18: with a (2-pyridyl)amino group) had the highest TS. On the other hand, doxorubicin and 5-fluorouracil (5-FU) were more highly cytotoxic to normal epithelial cells, displaying unexpectedly lower TS and PSE values. None of the compounds had anti-HIV activity. Among 330 chemical descriptors, 75, 73 and 19 descriptors significantly correlated to the cytotoxicity to normal and tumor cells, and TS, respectively. Multivariate statistics with chemical descriptors for molecular polarization and hydrophobicity may be useful for the evaluation of cytotoxicity and TS of oleoylamides. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Zoledronic acid and alendronate sodium and the implications in orthodontic movement.

PubMed

Franzoni, J S; Soares, F M P; Zaniboni, E; Vedovello Filho, M; Santamaria, M P; Dos Santos, G M T; Esquisatto, M A M; Felonato, M; Mendonca, F A S; Franzini, C M; Santamaria, M

2017-08-01

To evaluate orthodontic tooth movement (OTM) in rats treated with two types of bisphosphonates (BPs), alendronate sodium (A) and zoledronic acid (Z). In all, 15 male Wistar rats were randomly divided into three groups. Group OTM+A: orthodontic tooth movement and subcutaneous administration of alendronate sodium (2.5 mg/kg); Group OTM+Z: orthodontic tooth movement and subcutaneous administration of zoledronic acid (0.02 mg/kg), and Group OTM: orthodontic tooth movement and subcutaneous injection of saline. The BPs were administered once a day during 25 days before OTM started and during 10 days of OTM. The left upper first molar was moved with a stainless-steel closed coil spring which delivered an initial force of 0.4N. OTM was measured with a digital caliper comparing the moved and the contralateral side. The histomorphometric analysis counted the number of osteoclasts, inflammatory cells, blood vessels and fibroblasts (n/10 4  m 2 ) in periodontal ligament (PDL) of the distobuccal root. A reduction of 58.3% of OTM was found in Group OTM+A and 99.6% in Group OTM+Z, when compared with Group OTM. There was a significant decrease of osteoclasts and inflammatory cells in BP-treated groups. Blood vessels and fibroblastic cells decreased mainly in Group OTM+Z. Alendronate sodium and zoledronic acid have similar effects on the periodontal tissue during orthodontic treatment in rats. Especially, zoledronic acid can affect orthodontic tooth movement. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of titanium surface topography on morphology and in vitro activity of human gingival fibroblasts.

PubMed

Ramaglia, L; Capece, G; Di Spigna, G; Bruno, M P; Buonocore, N; Postiglione, L

2013-01-01

The aim of the present study was to evaluate in vitro the biological behavior of human gingival fibroblasts cultured on two different titanium surfaces. Titanium test disks were prepared with a machined, relatively smooth (S) surface or a rough surface (O) obtained by a double acid etching procedure. Primary cultures of human gingival fibroblasts were plated on the experimental titanium disks and cultured up to 14 days. Titanium disk surfaces were analysed by scanning electron microscopy (SEM). Cell proliferation and a quantitative analysis by ELISA in situ of ECM components as CoI, FN and TN were performed. Results have shown different effects of titanium surface microtopography on cell expression and differentiation. At 96 hours of culture on experimental surfaces human gingival fibroblasts displayed a favourable cell attachment and proliferation on both surfaces although showing some differences. Both the relatively smooth and the etched surfaces interacted actively with in vitro cultures of human gingival fibroblasts, promoting cell proliferation and differentiation. Results suggested that the microtopography of a double acid-etched rough surface may induce a greater Co I and FN production, thus conditioning in vivo the biological behaviour of human gingival fibroblasts during the process of peri-implant soft tissue healing.

Experimental strength of restorations with fibre posts at different stages, with and without using a simulated ligament.

PubMed

Pérez-González, A; González-Lluch, C; Sancho-Bru, J L; Rodríguez-Cervantes, P J; Barjau-Escribano, A; Forner-Navarro, L

2012-03-01

The aim of this study was to analyse the strength and failure mode of teeth restored with fibre posts under retention and flexural-compressive loads at different stages of the restoration and to analyse whether including a simulated ligament in the experimental setup has any effect on the strength or the failure mode. Thirty human maxillary central incisors were distributed in three different groups to be restored with simulation of different restoration stages (1: only post, 2: post and core, 3: post-core and crown), using Rebilda fibre posts. The specimens were inserted in resin blocks and loaded by means of a universal testing machine until failure under tension (stage 1) and 50º flexion (stages 2-3). Half the specimens in each group were restored using a simulated ligament between root dentine and resin block and the other half did not use this element. Failure in stage 1 always occurred at the post-dentine interface, with a mean failure load of 191·2 N. Failure in stage 2 was located mainly in the core or coronal dentine (mean failure load of 505·9 N). Failure in stage 3 was observed in the coronal dentine (mean failure load 397·4 N). Failure loads registered were greater than expected masticatory loads. Fracture modes were mostly reparable, thus indicating that this post is clinically valid at the different stages of restoration studied. The inclusion of the simulated ligament in the experimental system did not show a statistically significant effect on the failure load or the failure mode. © 2011 Blackwell Publishing Ltd.

Investigation of irradiation by different nonablative lasers on primary cultured skin fibroblasts.

PubMed

Weng, Y; Dang, Y; Ye, X; Liu, N; Zhang, Z; Ren, Q

2011-08-01

A variety of lasers with different wavelengths and biological effects are widely used for nonablative skin rejuvenation, but the underlying mechanisms have not been fully investigated. To investigate the effects of irradiation by different nonablative lasers on collagen synthesis and the antioxidant status of cultured fibroblasts to identify a possible mechanism for laser photorejuvenation. Cultured skin fibroblasts were irradiated with three different lasers: 532 nm potassium-titanyl phosphate (KTP), 1064 nm Q-switched neodymium:yttrium-aluminium-garnet (Nd:Yag) and 1064 nm long-pulse Nd:YAG, and production of collagen and changes in lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were assayed. Irradiation by all three lasers led to a marked increase in collagen production. Two major antioxidant enzymes, SOD and GSH, were significantly increased, whereas MDA was markedly reduced after laser irradiation. No change in LDH activity was found between nonirradiated and irradiated fibroblasts. This study indicates that the increased collagen synthesis by fibroblasts after laser treatment may be partly due to improved antioxidant capacity, which reduces oxidative stress and thus stimulates new collagen production. © The Author(s). CED © 2011 British Association of Dermatologists.

Quantifying the Nonlinear, Anisotropic Material Response of Spinal Ligaments

NASA Astrophysics Data System (ADS)

Robertson, Daniel J.

Spinal ligaments may be a significant source of chronic back pain, yet they are often disregarded by the clinical community due to a lack of information with regards to their material response, and innervation characteristics. The purpose of this dissertation was to characterize the material response of spinal ligaments and to review their innervation characteristics. Review of relevant literature revealed that all of the major spinal ligaments are innervated. They cause painful sensations when irritated and provide reflexive control of the deep spinal musculature. As such, including the neurologic implications of iatrogenic ligament damage in the evaluation of surgical procedures aimed at relieving back pain will likely result in more effective long-term solutions. The material response of spinal ligaments has not previously been fully quantified due to limitations associated with standard soft tissue testing techniques. The present work presents and validates a novel testing methodology capable of overcoming these limitations. In particular, the anisotropic, inhomogeneous material constitutive properties of the human supraspinous ligament are quantified and methods for determining the response of the other spinal ligaments are presented. In addition, a method for determining the anisotropic, inhomogeneous pre-strain distribution of the spinal ligaments is presented. The multi-axial pre-strain distributions of the human anterior longitudinal ligament, ligamentum flavum and supraspinous ligament were determined using this methodology. Results from this work clearly demonstrate that spinal ligaments are not uniaxial structures, and that finite element models which account for pre-strain and incorporate ligament's complex material properties may provide increased fidelity to the in vivo condition.

Combined medial and lateral anatomic ligament reconstruction for chronic rotational instability of the ankle.

PubMed

Buchhorn, Tomas; Sabeti-Aschraf, Manuel; Dlaska, Constantin E; Wenzel, Florian; Graf, Alexandra; Ziai, Pejman

2011-12-01

This study aimed to extend knowledge on the arthroscopic evaluation of the unstable ankle joint and the outcome of ligament reconstruction on rotational instability. In contrast to previous studies, we investigated the combined repair of lateral and medial ligaments. Ninety-six patients underwent medial and lateral ligament reconstruction between 2006 and 2008, 81 of whom, with a mean age of 31.9 (range, 14 to 44) years, completed the 12-month followup and were therefore included in this study (Table 1). Clinical, radiographic, and concomitant arthroscopic examination was performed prior to the ligament stabilization. Postoperative followup included clinical and radiographic evaluation after 3, 6, and 12 months. Arthroscopy showed a lesion of the anterior fibulotalar ligament (AFTL), calcaneofibular ligament (CFL), and tibiocalcanear ligament (TCL) (Deep part of deltoid ligament complex) in 67 patients. An avulsion of the proximal insertion point of the ATTL was additionally found in 14 cases. Clinical results 3 months after surgery showed a significant increase in the AOFAS-Hindfoot Score as well as a significant decrease of the Visual Analogue-Scale for pain (VAS) (p < 0.0001). This outcome persisted at the 12-month examination. Rotational instability of the ankle joint in most cases has an injury of the lateral ligaments and a component of the deltoid, the TCL, but rarely with a combined lesion of the TCL and the anterior tibiotalar ligament (ATTL) (Superficial part of deltoid ligament complex). The combined lateral and medial ligament reconstruction with an anchor technique had a good clinical outcome with high patient satisfaction with few complications.

Isolation and Characterization of Human Mesenchymal Stem Cells From Facet Joints and Interspinous Ligaments.

PubMed

Kristjánsson, Baldur; Limthongkul, Worawat; Yingsakmongkol, Wicharn; Thantiworasit, Pattarawat; Jirathanathornnukul, Napaphat; Honsawek, Sittisak

2016-01-01

A descriptive in vitro study on isolation and differentiation of human mesenchymal stem cells (MSCs) derived from the facet joints and interspinous ligaments. To isolate cells from the facet joints and interspinous ligaments and investigate their surface marker profile and differentiation potentials. Lumbar spinal canal stenosis and ossification of the posterior longitudinal ligament are progressive conditions characterized by the hypertrophy and ossification of ligaments and joints within the spinal canal. MSCs are believed to play a role in the advancement of these diseases and the existence of MSCs has been demonstrated within the ligamentum flavum and posterior longitudinal ligament. The aim of this study was to investigate whether these cells could also be found within facet joints and interspinous ligaments. Samples were harvested from 10 patients undergoing spinal surgery. The MSCs from facet joints and interspinous ligaments were isolated using direct tissue explant technique. Cell surface antigen profilings were performed via flow cytometry. Their lineage differentiation potentials were analyzed. The facet joints and interspinous ligaments-derived MSCs have the tri-lineage potential to be differentiated into osteogenic, adipogenic, and chondrogenic cells under appropriate inductions. Flow cytometry analysis revealed both cell lines expressed MSCs markers. Both facet joints and interspinous ligaments-derived MSCs expressed marker genes for osteoblasts, adipocytes, and chondrocytes. The facet joints and interspinous ligaments may provide alternative sources of MSCs for tissue engineering applications. The facet joints and interspinous ligaments-derived MSCs are part of the microenvironment of the human ligaments of the spinal column and might play a crucial role in the development and progression of degenerative spine conditions.

Induction and repair of radiation-induced DNA double-strand breaks in human fibroblasts are not affected by terminal differentiation.

PubMed

Brammer, Ingo; Herskind, Carsten; Haase, Oliver; Rodemann, H Peter; Dikomey, Ekkehard

2004-02-03

It was studied for human skin fibroblasts, whether the induction or repair of DNA double-strand breaks (dsb) depend on the differentiation status. These studies were performed (a) with a fibroblast strain (HSF1) kept in progenitor state (mitotic fibroblasts, MF) or triggered to premature terminal differentiation (postmitotic fibrocytes, PMF) by exposure to mitomycin C or (b) with 20 fibroblast strains differing intrinsically in their differentiation status. The differentiation status was quantified by determining the fraction of postmitotic fibrocytes by light microscopy. DNA dsb were measured by constant-field gel electrophoresis, and the fraction of apoptotic cells by comet assay. MF and PMF cultures of HSF1 cells were irradiated with X-ray doses up to 160 Gy, and dsb were measured either immediately after irradiation or after a repair incubation of 4 or 24 h. There were a difference neither in the number of initial nor residual dsb. PMF cultures, however, showed a slightly higher number of dsb already present in non-irradiated cells, which was measured to result from a small fraction of 5% apoptotic cells. The 20 analysed fibroblast strains showed a substantial variation in the fraction of postmitotic fibrocytes (9-51%) as well as in the number of dsb remaining at 24 h after irradiation (1.9-4.9%), but there was no correlation between these two parameters. These data demonstrate that for fibroblasts the terminal differentiation has an effect neither on the induction nor the repair of radiation-induced dsb. This result indicates that the variation in dsb-repair capacity previously observed for fibroblast strains and which was considered to be the main cause for the variation in the cellular radiosensitivity, cannot be ascribed to differences in the differentiation status.

Fibroblast-matrix interplay: Nintedanib and pirfenidone modulate the effect of IPF fibroblast-conditioned matrix on normal fibroblast phenotype.

PubMed

Epstein Shochet, Gali; Wollin, Lutz; Shitrit, David

2018-03-12

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with poor prognosis. Activated fibroblasts are the key effector cells in fibrosis, producing excessive amounts of collagen and extracellular matrix (ECM) proteins. Whether the ECM conditioned by IPF fibroblasts determines the phenotype of naïve fibroblasts is difficult to explore. IPF-derived primary fibroblasts were cultured on Matrigel and then cleared using ammonium hydroxide, creating an IPF-conditioned matrix (CM). Normal fibroblast CM served as control. Normal fibroblasts were cultured on both types of CM, and cell count, cell distribution and markers of myofibroblast differentiation; transforming growth factor beta (TGFβ) signalling; and ECM expression were assessed. The effects of the anti-fibrotic drugs nintedanib and pirfenidone at physiologically relevant concentrations were also explored. Normal fibroblasts cultured on IPF-CM arranged in large aggregates as a result of increased proliferation and migration. Moreover, increased levels of pSmad3, pSTAT3 (phospho signal transducer and activator of transcription 3), alpha smooth muscle actin (αSMA) and Collagen1a were found, suggesting a differentiation towards a myofibroblast-like phenotype. SB505124 (10 μmol/L) partially reversed these alterations, suggesting a TGFβ contribution. Furthermore, nintedanib at 100 nmol/L and, to a lesser extent, pirfenidone at 100 μmol/L prevented the IPF-CM-induced fibroblast phenotype alterations, suggesting an attenuation of the ECM-fibroblast interplay. IPF fibroblasts alter the ECM, thus creating a CM that further propagates an IPF-like phenotype in normal fibroblasts. This assay demonstrated differences in drug activities for approved IPF drugs at clinically relevant concentrations. Thus, the matrix-fibroblast phenotype interplay might be a relevant assay to explore drug candidates for IPF treatment. © 2018 Asian Pacific Society of Respirology.

Age-related disruption of autophagy in dermal fibroblasts modulates extracellular matrix components

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

Tashiro, Kanae; Division of Pharmaceutical Cell Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka; Shishido, Mayumi

2014-01-03

Highlights: •Autophagosomes accumulate in aged dermal fibroblasts. •Autophagic degradation is impaired in aged dermal fibroblasts. •Autophagy disruption affects extracellular matrix components in dermal fibroblasts. -- Abstract: Autophagy is an intracellular degradative system that is believed to be involved in the aging process. The contribution of autophagy to age-related changes in the human skin is unclear. In this study, we examined the relationship between autophagy and skin aging. Transmission electron microscopy and immunofluorescence microscopy analyses of skin tissue and cultured dermal fibroblasts derived from women of different ages revealed an increase in the number of nascent double-membrane autophagosomes with age. Westernmore » blot analysis showed that the amount of LC3-II, a form associated with autophagic vacuolar membranes, was significantly increased in aged dermal fibroblasts compared with that in young dermal fibroblasts. Aged dermal fibroblasts were minimally affected by inhibition of autophagic activity. Although lipofuscin autofluorescence was elevated in aged dermal fibroblasts, the expression of Beclin-1 and Atg5—genes essential for autophagosome formation—was similar between young and aged dermal fibroblasts, suggesting that the increase of autophagosomes in aged dermal fibroblasts was due to impaired autophagic flux rather than an increase in autophagosome formation. Treatment of young dermal fibroblasts with lysosomal protease inhibitors, which mimic the condition of aged dermal fibroblasts with reduced autophagic activity, altered the fibroblast content of type I procollagen, hyaluronan and elastin, and caused a breakdown of collagen fibrils. Collectively, these findings suggest that the autophagy pathway is impaired in aged dermal fibroblasts, which leads to deterioration of dermal integrity and skin fragility.« less

Aspirin Enhances Osteogenic Potential of Periodontal Ligament Stem Cells (PDLSCs) and Modulates the Expression Profile of Growth Factor-Associated Genes in PDLSCs.

PubMed

Abd Rahman, Fazliny; Mohd Ali, Johari; Abdullah, Mariam; Abu Kasim, Noor Hayaty; Musa, Sabri

2016-07-01

This study investigates the effects of aspirin (ASA) on the proliferative capacity, osteogenic potential, and expression of growth factor-associated genes in periodontal ligament stem cells (PDLSCs). Mesenchymal stem cells (MSCs) from PDL tissue were isolated from human premolars (n = 3). The MSCs' identity was confirmed by immunophenotyping and trilineage differentiation assays. Cell proliferation activity was assessed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Polymerase chain reaction array was used to profile the expression of 84 growth factor-associated genes. Pathway analysis was used to identify the biologic functions and canonic pathways activated by ASA treatment. The osteogenic potential was evaluated through mineralization assay. ASA at 1,000 μM enhances osteogenic potential of PDLSCs. Using a fold change (FC) of 2.0 as a threshold value, the gene expression analyses indicated that 19 genes were differentially expressed, which includes 12 upregulated and seven downregulated genes. Fibroblast growth factor 9 (FGF9), vascular endothelial growth factor A (VEGFA), interleukin-2, bone morphogenetic protein-10, VEGFC, and 2 (FGF2) were markedly upregulated (FC range, 6 to 15), whereas pleotropin, FGF5, brain-derived neurotrophic factor, and Dickkopf WNT signaling pathway inhibitor 1 were markedly downregulated (FC 32). Of the 84 growth factor-associated genes screened, 35 showed high cycle threshold values (≥35). ASA modulates the expression of growth factor-associated genes and enhances osteogenic potential in PDLSCs. ASA upregulated the expression of genes that could activate biologic functions and canonic pathways related to cell proliferation, human embryonic stem cell pluripotency, tissue regeneration, and differentiation. These findings suggest that ASA enhances PDLSC function and may be useful in regenerative dentistry applications, particularly in the areas of periodontal health and regeneration.

Use of Rat Mature Adipocyte-Derived Dedifferentiated Fat Cells as a Cell Source for Periodontal Tissue Regeneration

PubMed Central

Akita, Daisuke; Kano, Koichiro; Saito-Tamura, Yoko; Mashimo, Takayuki; Sato-Shionome, Momoko; Tsurumachi, Niina; Yamanaka, Katsuyuki; Kaneko, Tadashi; Toriumi, Taku; Arai, Yoshinori; Tsukimura, Naoki; Matsumoto, Taro; Ishigami, Tomohiko; Isokawa, Keitaro; Honda, Masaki

2016-01-01

Lipid-free fibroblast-like cells, known as dedifferentiated fat (DFAT) cells, can be generated from mature adipocytes with a large single lipid droplet. DFAT cells can re-establish their active proliferation ability and can transdifferentiate into various cell types under appropriate culture conditions. The first objective of this study was to compare the multilineage differentiation potential of DFAT cells with that of adipose-derived stem cells (ASCs) on mesenchymal stem cells. We obtained DFAT cells and ASCs from inbred rats and found that rat DFAT cells possess higher osteogenic differentiation potential than rat ASCs. On the other hand, DFAT cells show similar adipogenic differentiation, and chondrogenic differentiation potential in comparison with ASCs. The second objective of this study was to assess the regenerative potential of DFAT cells combined with novel solid scaffolds composed of PLGA (Poly d, l-lactic-co-glycolic acid) on periodontal tissue, and to compare this with the regenerative potential of ASCs combined with PLGA scaffolds. Cultured DFAT cells and ASCs were seeded onto PLGA scaffolds (DFAT/PLGA and ASCs/PLGA) and transplanted into periodontal fenestration defects in rat mandible. Micro computed tomography analysis revealed a significantly higher amount of bone regeneration in the DFAT/PLGA group compared with that of ASCs/PLGA and PLGA-alone groups at 2, 3, and 5 weeks after transplantation. Similarly, histomorphometric analysis showed that DFAT/PLGA groups had significantly greater width of cementum, periodontal ligament and alveolar bone than ASCs/PLGA and PLGA-alone groups. In addition, transplanted fluorescent-labeled DFAT cells were observed in the periodontal ligament beside the newly formed bone and cementum. These findings suggest that DFAT cells have a greater potential for enhancing periodontal tissue regeneration than ASCs. Therefore, DFAT cells are a promising cell source for periodontium regeneration. PMID:26941649

A comparative study of effect of autograft compared with allograft anterior cruciate ligament reconstruction on expressions of LOXs and MMPs

PubMed Central

Wang, Wei-Ming; Ma, Xiao-Jun; Huang, Shi-Bo; Ren, Liu-Bao

2017-01-01

The present study aimed to compare the effect of autograft or allograft anterior cruciate ligament (ACL) reconstruction on the expressions of lipoxygenases (LOXs) and matrix metalloproteinases (MMPs) in a New Zealand white rabbit model. New Zealand white rabbits were divided randomly into control, sham, autograft and allograft groups. At the 4th and 8th week after operation, biomechanical testing was performed to measure the primary length, cross-sectional area, maximum tensile load and stiffness of ACL, and HE staining was used to observe cell morphology and fibre alignment of ACL. At the 2nd, 4th and 8th week after operation, quantitative real-time PCR (qRT-PCR), Western blotting and immunohistochemistry were applied to detect LOXs and MMPs expressions, and expressions of adenomatous polyposis coli (APC)/Wnt signalling pathway-related proteins. At the 4th and 8th week after operation, the maximum tensile load and stiffness were higher in the autograft group than in the allograft group, and the values at the 8th week were higher than those at the 4th week after operation. The fibroblast proliferation in the allograft group was more significant than that in the autograft group. Compared with the control group, LOXs and MMPs expressions and the positive expression rates of LOXs and MMPs proteins were elevated, and the values in the allograft group were higher than those in the autograft group at all time points. At 8th week after operation, compared with the autograft group, Wnt expression was higher and APC expression was lower in the allograft group. Autograft and allograft ACL reconstruction can promote LOXs and MMPs expressions by activating the APC/Wnt signalling pathway. PMID:28275205

Stable Versus Unstable Grade II High Ankle Sprains: A Prospective Study Predicting the Need for Surgical Stabilization and Time to Return to Sports.

PubMed

Calder, James D; Bamford, Richard; Petrie, Aviva; McCollum, Graham A

2016-04-01

To investigate grade II syndesmosis injuries in athletes and identify factors important in differentiating stable from dynamically unstable ankle sprains and those associated with a longer time to return to sports. Sixty-four athletes with an isolated syndesmosis injury (without fracture) were prospectively assessed, with a mean follow-up period of 37 months (range, 24 to 66 months). Those with an associated deltoid ligament injury or osteochondral lesion were included. Those whose injuries were considered stable (grade IIa) were treated conservatively with a boot and rehabilitation. Those whose injuries were clinically unstable underwent arthroscopy, and if instability was confirmed (grade IIb), the syndesmosis was stabilized. Clinical and magnetic resonance imaging assessments of injury to individual ligaments were recorded, along with time to return to play. A power analysis estimated that each group would need 28 patients. All athletes returned to the same level of professional sport. The 28 patients with grade IIa injuries returned at a mean of 45 days (range, 23 to 63 days) compared with 64 days (range, 27 to 104 days) for those with grade IIb injuries (P < .0001). There was a highly significant relationship between clinical and magnetic resonance imaging assessments of ligament injury (anterior tibiofibular ligament [ATFL], anterior-inferior tibiofibular ligament [AITFL], and deltoid ligament, P < .0001). Instability was 9.5 times as likely with a positive squeeze test and 11 times as likely with a deltoid injury. Combined injury to the anterior-inferior tibiofibular ligament and deltoid ligament was associated with a delay in return to sports. Concomitant injury to the ATFL indicated a different mechanism of injury-the syndesmosis is less likely to be unstable and is associated with an earlier return to sports. A positive squeeze test and injury to the ATFL and deltoid ligament are important factors in differentiating stable from dynamically unstable grade II injuries and may be used to identify which athletes may benefit from early arthroscopic assessment and stabilization. They may also be important in predicting the time frame for athletes' expected return to play. Level II, prospective comparative study. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Ligamentous Injuries and the Risk of Associated Tissue Damage in Acute Ankle Sprains in Athletes: A Cross-sectional MRI Study.

PubMed

Roemer, Frank W; Jomaah, Nabil; Niu, Jingbo; Almusa, Emad; Roger, Bernard; D'Hooghe, Pieter; Geertsema, Celeste; Tol, Johannes L; Khan, Karim; Guermazi, Ali

2014-07-01

Ankle joint injuries are extremely common sports injuries, with the anterior talofibular ligament involved in the majority of ankle sprains. There have been only a few large magnetic resonance imaging (MRI) studies on associated structural injuries after ankle sprains. To describe the injury pattern in athletes who were referred to MRI for the assessment of an acute ankle sprain and to assess the risk of associated traumatic tissue damage including lateral and syndesmotic ligament involvement. Cross-sectional study; Level of evidence, 3. A total of 261 ankle MRI scans of athletes with acute ankle sprains were evaluated for: lateral and syndesmotic ligament injury; concomitant injuries to the deltoid and spring ligaments and sinus tarsi; peroneal, flexor, and extensor retinacula and tendons; traumatic and nontraumatic osteochondral and osseous changes; and joint effusion. Patients were on average 22.5 years old, and the average time from injury to MRI was 5.7 days. Six exclusive injury patterns were defined based on lateral and syndesmotic ligament involvement. The risk for associated injuries was assessed by logistic regression using ankles with no or only low-grade lateral ligament injuries and no syndesmotic ligament damage as the reference. With regard to the injury pattern, there were 103 ankles (39.5%) with complete anterior talofibular ligament disruption and no syndesmotic injury, and 53 ankles (20.3%) had a syndesmotic injury with or without lateral ligament damage. Acute osteochondral lesions of the lateral talar dome were seen in 20 ankles (7.7%). The percentage of chronic lateral osteochondral lesions was 1.1%. The risk for talar bone contusions increased more than 3-fold for ankles with complete lateral ligament ruptures (adjusted odds ratio [aOR], 3.43; 95% CI, 1.72-6.85) but not for ankles with syndesmotic involvement. The risk for associated deltoid ligament injuries increased for ankles with complete lateral ligament injuries (aOR, 4.04; 95% CI, 1.99-8.22) compared with patients with no or only low-grade lateral ligament injuries. About 20% of athletes referred for MRI after suffering an acute ankle sprain had evidence of a syndesmotic injury regardless of lateral ligament involvement, while more than half had evidence of any lateral ligament injury without syndesmotic involvement. Concomitant talar osseous and deltoid ligament injuries are common. © 2014 The Author(s).

The effect of polystyrene sodium sulfonate grafting on polyethylene terephthalate artificial ligaments on in vitro mineralisation and in vivo bone tissue integration

PubMed Central

Vaquette, Cédryck; Viateau, Véronique; Guérard, Sandra; Anagnostou, Fani; Manassero, Mathieu; Castner, David G.; Migonney, Véronique

2013-01-01

This study investigates the impact of polystyrene sodium sulfonate (PolyNaSS) grafting onto the osseointegration of a polyethylene terephthalate artificial ligament (Ligament Advanced Reinforcement System, LARS™) used for Anterior Cruciate Ligament (ACL). The performance of grafted and non-grafted ligaments was assessed in vitro by culturing human osteoblasts under osteogenic induction and this demonstrated that the surface modification was capable of up-regulating the secretion of ALP and induced higher level of mineralisation as measured 6 weeks post-seeding by Micro-Computed Tomography. Grafted and non-grafted LARS™ were subsequently implanted in an ovine model for ACL reconstruction and the ligament-to-bone interface was evaluated by histology and biomechanical testing 3 and 12 months post-implantation. The grafted ligaments exhibited more frequent direct ligament-to-bone contact and bone formation in the core of the ligament at the later time point than the nongrafted specimens, the grafting also significantly reduced the fibrous encapsulation of the ligament 12 months post-implantation. However, this improved osseo-integration was not translated into a significant increase in the biomechanical pull-out loads. These results provide evidences that PolyNaSS grafting improved the osseo-integration of the artificial ligament within the bone tunnels. This might positively influence the outcome of the surgical reconstructions, as higher ligament stability is believed to limit micro-movement and therefore permits earlier and enhanced healing. PMID:23790438

Reduced step length reduces knee joint contact forces during running following anterior cruciate ligament reconstruction but does not alter inter-limb asymmetry.

PubMed

Bowersock, Collin D; Willy, Richard W; DeVita, Paul; Willson, John D

2017-03-01

Anterior cruciate ligament reconstruction is associated with early onset knee osteoarthritis. Running is a typical activity following this surgery, but elevated knee joint contact forces are thought to contribute to osteoarthritis degenerative processes. It is therefore clinically relevant to identify interventions to reduce contact forces during running among individuals after anterior cruciate ligament reconstruction. The primary purpose of this study was to evaluate the effect of reducing step length during running on patellofemoral and tibiofemoral joint contact forces among people with a history of anterior cruciate ligament reconstruction. Inter limb knee joint contact force differences during running were also examined. 18 individuals at an average of 54.8months after unilateral anterior cruciate ligament reconstruction ran in 3 step length conditions (preferred, -5%, -10%). Bilateral patellofemoral, tibiofemoral, and medial tibiofemoral compartment peak force, loading rate, impulse, and impulse per kilometer were evaluated between step length conditions and limbs using separate 2 factor analyses of variance. Reducing step length 5% decreased patellofemoral, tibiofemoral, and medial tibiofemoral compartment peak force, impulse, and impulse per kilometer bilaterally. A 10% step length reduction further decreased peak forces and force impulses, but did not further reduce force impulses per kilometer. Tibiofemoral joint impulse, impulse per kilometer, and patellofemoral joint loading rate were lower in the previously injured limb compared to the contralateral limb. Running with a shorter step length is a feasible clinical intervention to reduce knee joint contact forces during running among people with a history of anterior cruciate ligament reconstruction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Does the tibial remnant of the anterior cruciate ligament promote ligamentization?

PubMed

Lee, Byung Ill; Kim, Byoung Min; Kho, Duk Hwan; Kwon, Sai Won; Kim, Hyeung June; Hwang, Hyun Ryong

2016-12-01

The purpose of this study was to clarify the difference in ligamentization between the remnant-preserving (RP) and remnant-sacrificing (RS) techniques in anterior cruciate ligament (ACL) reconstruction using magnetic resonance imaging (MRI). A retrospective comparative study was carried out on 98 patients undergoing ACL reconstruction using either an RP (n=56) or RS (n=42) technique. MRI was performed at one of four time points postoperatively, and the signal intensity of the ACL graft was analyzed using the signal to noise quotient (SNQ) ratio and inter-bundle high signal intensity, along with an analysis of the survival rate of remnant tissue. The mean SNQ ratio of grafted tendons in the RP group was significantly higher than that seen in the RS group in the proximal and middle regions two to four months after surgery (P<0.05) and was significantly lower than that seen in the RS group in all regions at 12 -18months (P<0.05). The inter-bundle high signal intensity was observed more frequently in the RP group (73.7%) at two to four months. Tibial remnants were observed on postoperative MRI regardless of when MRI was conducted. The ACL graft of the RP group showed higher signal intensity in the early stage and lower signal intensity in the late stage compared to that of the RS group. The ligamentization of grafts in the RP group proceeded more quickly. Preserving the remnant in ACL reconstruction appears to have a positive effect on ligamentization. Copyright © 2016 Elsevier B.V. All rights reserved.

Evidence for colonization and destruction of hinge ligaments in cultured juvenile Pacific oysters (Crassostrea gigas) by cytophaga-like bacteria.

PubMed Central

Dungan, C F; Elston, R A; Schiewe, M H

1989-01-01

Several strains of cytophaga-like gliding bacteria (CLB) were isolated as numerically dominant or codominant components of bacterial populations associated with proteinaceous hinge ligaments of cultured juvenile Pacific oysters, Crassostrea gigas. These bacteria were morphologically similar to long, flexible bacilli occurring within degenerative lesions in oyster hinge ligaments. Among bacteria isolated from hinge ligaments, only CLB strains were capable of sustained growth with hinge ligament matrix as the sole source of organic carbon and nitrogen. In vitro incubation of cuboidal portions of ligament resilium with ligament CLB resulted in bacterial proliferation on the surfaces and penetration deep into ligament matrices. Bacterial proliferation was accompanied by loss of resilium structural and mechanical integrity, including complete liquefaction, at incubation temperatures between 10 and 20 degrees C. The morphological, distributional, and degradative characteristics of CLB isolated from oyster hinge ligaments provide compelling, albeit indirect, evidence that CLB are the agents of a degenerative disease affecting juvenile cultured oysters. The motility, metabolic, and hydrolytic characteristics of hinge ligament CLB and the low moles percent G + C values (32.4 to 32.9) determined for three representative strains indicate that they are marine Cytophaga spp. Images PMID:2757377

Evidence for colonization and destruction of hinge ligaments in cultured juvenile Pacific oysters (Crassostrea gigas) by cytophaga-like bacteria.

PubMed

Dungan, C F; Elston, R A; Schiewe, M H

1989-05-01

Several strains of cytophaga-like gliding bacteria (CLB) were isolated as numerically dominant or codominant components of bacterial populations associated with proteinaceous hinge ligaments of cultured juvenile Pacific oysters, Crassostrea gigas. These bacteria were morphologically similar to long, flexible bacilli occurring within degenerative lesions in oyster hinge ligaments. Among bacteria isolated from hinge ligaments, only CLB strains were capable of sustained growth with hinge ligament matrix as the sole source of organic carbon and nitrogen. In vitro incubation of cuboidal portions of ligament resilium with ligament CLB resulted in bacterial proliferation on the surfaces and penetration deep into ligament matrices. Bacterial proliferation was accompanied by loss of resilium structural and mechanical integrity, including complete liquefaction, at incubation temperatures between 10 and 20 degrees C. The morphological, distributional, and degradative characteristics of CLB isolated from oyster hinge ligaments provide compelling, albeit indirect, evidence that CLB are the agents of a degenerative disease affecting juvenile cultured oysters. The motility, metabolic, and hydrolytic characteristics of hinge ligament CLB and the low moles percent G + C values (32.4 to 32.9) determined for three representative strains indicate that they are marine Cytophaga spp.

Combined Spring and Deltoid Ligament Repair in Adult-Acquired Flatfoot.

PubMed

Nery, Caio; Lemos, André Vitor Kerber C; Raduan, Fernando; Mansur, Nacime Salomão B; Baumfeld, Daniel

2018-04-01

Adult-acquired flatfoot deformity (AAFD) is usually due to a combination of mechanical failure of the osteoligamentous complex that maintains the medial longitudinal arch of the foot and attenuation or complete tear of the posterior tibial tendon. Magnetic resonance imaging studies in patients with flatfoot deformities have reported the posterior tibial tendon to be pathologic in up to 100% of patients, the spring ligament in up to 87%, and the deltoid ligament in 33%. Many studies in the literature describe reconstruction of the spring ligament or the deltoid ligament associated with AAFD, but there is no study in which both (spring and deltoid) ligaments are reconstructed at the same time. We describe a novel technique to reconstruct the deltoid ligament and the spring ligament at the same time. We described the technique and evaluated 10 consecutive patients with AAFD and insufficient ankle and midfoot ligaments. We found no postoperative complications, stiffness, or loss of correction. We present a novel technique to reconstruct the failed deltoid and spring ligament during flatfoot correction. It is unique in that it uses internal brace augmentation with FiberTape ® to help and protect the soft tissue healing. Level IV, retrospective case series.

Development of Tissue-Engineered Ligaments: Elastin Promotes Regeneration of the Rabbit Medial Collateral Ligament.

PubMed

Hirukawa, Masaki; Katayama, Shingo; Sato, Tatsuya; Yamada, Masayoshi; Kageyama, Satoshi; Unno, Hironori; Suzuki, Yoshiaki; Miura, Yoshihiro; Shiratsuchi, Eri; Hasegawa, Masahiro; Miyamoto, Keiichi; Horiuchi, Takashi

2017-12-21

When ligaments are injured, reconstructive surgery is sometimes required to restore function. Methods of reconstructive surgery include transplantation of an artificial ligament and autotransplantation of a tendon. However, these methods have limitations related to the strength of the bone-ligament insertion and biocompatibility of the transplanted tissue after surgery. Therefore, it is necessary to develop new reconstruction methods and pursue the development of artificial ligaments. Elastin is a major component of elastic fibers and ligaments. However, the role of elastin in ligament regeneration has not been described. Here, we developed a rabbit model of a medial collateral ligament (MCL) rupture and treated animal knees with exogenous elastin [100 µg/(0.5 mL·week)] for 6 or 12 weeks. Elastin treatment increased gene expression and protein content of collagen and elastin (gene expression, 6-fold and 42-fold, respectively; protein content, 1.6-fold and 1.9-fold, respectively), and also increased the elastic modulus of MCL increased with elastin treatment (2-fold) compared with the controls. Our data suggest that elastin is involved in the regeneration of damaged ligaments. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Regional fibrocartilage variations in human anterior cruciate ligament tibial insertion: a histological three-dimensional reconstruction.

PubMed

Dai, Can; Guo, Lin; Yang, Liu; Wu, Yi; Gou, Jingyue; Li, Bangchun

2015-02-01

We studied anterior cruciate ligament (ACL) tibial insertion architecture in humans and investigated regional differences that could suggest unequal force transmission from ligament to bone. ACL tibial insertions were processed histologically. With Photoshop software, digital images taken from the histological slides were collaged, contour lines were drawn, and different gray values were filled based on the structure. The data were exported to Amira software for three-dimensional reconstruction. The uncalcified fibrocartilage (UF) layer was divided into three regions: lateral, medial and posterior according to the architecture. The UF zone was significantly thicker laterally than medially or posteriorly (p < 0.05). Similarly, the calcified fibrocartilage (CF) thickness was significantly greater in the lateral part of the enthesis compared to the medial and posterior parts (p < 0.05). The UF quantity (more UF laterally) corresponding to the CF quantity (more CF laterally) at the ACL tibial insertion provides further evidence suggesting that the load transferred from the ACL to the tibia was greater laterally than medially and posteriorly.

Surface modification of nano-silica on the ligament advanced reinforcement system for accelerated bone formation: primary human osteoblasts testing in vitro and animal testing in vivo

NASA Astrophysics Data System (ADS)

Li, Mengmeng; Wang, Shiwen; Jiang, Jia; Sun, Jiashu; Li, Yuzhuo; Huang, Deyong; Long, Yun-Ze; Zheng, Wenfu; Chen, Shiyi; Jiang, Xingyu

2015-04-01

The Ligament Advanced Reinforcement System (LARS) has been considered as a promising graft for ligament reconstruction. To improve its biocompatibility and effectiveness on new bone formation, we modified the surface of a polyethylene terephthalate (PET) ligament with nanoscale silica using atom transfer radical polymerization (ATRP) and silica polymerization. The modified ligament is tested by both in vitro and in vivo experiments. Human osteoblast testing in vitro exhibits an ~21% higher value in cell viability for silica-modified grafts compared with original grafts. Animal testing in vivo shows that there is new formed bone in the case of a nanoscale silica-coated ligament. These results demonstrate that our approach for nanoscale silica surface modification on LARS could be potentially applied for ligament reconstruction.The Ligament Advanced Reinforcement System (LARS) has been considered as a promising graft for ligament reconstruction. To improve its biocompatibility and effectiveness on new bone formation, we modified the surface of a polyethylene terephthalate (PET) ligament with nanoscale silica using atom transfer radical polymerization (ATRP) and silica polymerization. The modified ligament is tested by both in vitro and in vivo experiments. Human osteoblast testing in vitro exhibits an ~21% higher value in cell viability for silica-modified grafts compared with original grafts. Animal testing in vivo shows that there is new formed bone in the case of a nanoscale silica-coated ligament. These results demonstrate that our approach for nanoscale silica surface modification on LARS could be potentially applied for ligament reconstruction. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr01439e

[Treatment of complete acromioclavicular joint dislocation with transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament].

PubMed

Dong, Wen-Wei; Shi, Zeng-Yuan; Liu, Zheng-Xin; Mao, Hai-Jiao

2015-04-01

To explore the operation methods and clinical effects of transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament in treating complete acromioclavicular joint dislocation. From January 2006 to June 2012,26 patients with acute complete acromioclavicular joint dislocation underwent surgery. Transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament, additional clavical hoot plate and Kirschner wires fixation, were performed in all the patients. Among the patients, 18 patients were male and 8 patients were female, with an average age of 36.7 years old (ranged from 25 to 51 years). The duration from injury to operation was from 3 to 12 days with an average of 5 days. According to the Rockwood classification, 4 cases were grade III and 22 cases were grade V . Clinical manifestation included local swelling, tenderness with snapping, limitation of shoulder joint motion. In preoperative bilateral shoulder joint X-rays, the injured coracoclavicular distance was (16.2 ± 5.0) mm which was significantly wider than that of uninjured sides (7.6 ± 1.0) mm. Clinical results were evaluated according to X-rays and Constant-Murley score. All incisions obtained primary healing after operation without complication of infection, internal fixation breakage, redislocation. All the patients were followed up from 12 to 30 months with an average of 18 months. Kirschner wires and internal fixation plate were removed at 1 month and 8-10 months after operation, respectively. At final follow-up, the motion of shoulder joint recovered to normal and a no pain joint was obtained. According to Constant-Murley score, 24 cases got excellent results and 2 cases good. There was no significant difference after operation between the injured coracoclavicular distance and the uninjured contralateral side [(7.7 ± 1.2) mm vs (7.6 ± 1.0) mm), P > 0.05]. Transfer of the medial half of the coracoacromial ligament to reconstruct the coracoclavicular ligament, additional fixation using hook plate and Kirschner wires is the effective surgical method in treating complete acute acromioclavicular joint dislocation.

Meniscal tears missed on MR imaging: relationship to meniscal tear patterns and anterior cruciate ligament tears.

PubMed

De Smet, A A; Graf, B K

1994-04-01

MR imaging of the knee is a valuable technique for diagnosing meniscal tears, but some tears found at arthroscopy are not shown on MR imaging. The purpose of this study was to determine whether or not tears were more frequently missed in the presence of an anterior cruciate ligament tear or when tears had certain locations or configurations. We reviewed the original MR reports and surgical records of 400 patients who had both an MR examination and arthroscopy of the knee. Using chi 2 analysis, we examined how the sensitivity for detecting meniscal tears varied with the presence of a tear of the anterior cruciate ligament, with the location of the tear within the meniscus, and among six configurations of meniscal tears. We also studied whether sensitivity decreased with an increasing delay between MR examination and arthroscopy. In the presence of a tear of the anterior cruciate ligament, the sensitivity decreased from 0.97 to 0.88 (p = .016) for medial meniscal tears and from 0.94 to 0.69 (p = .0005) for lateral tears. The overall sensitivity for lateral meniscal tears was significantly less for posterior (p = .001) and peripheral (p = .005) tears than for other tear locations or configurations. The sensitivities did not significantly differ between tear locations and configurations in the medial meniscus or with an increasing delay until arthroscopy. Patients with a torn anterior cruciate ligament were more likely to have peripheral tears of the medial meniscus (p = .00004) and posterior (p = .0004) and peripheral (p = .04) tears of the lateral meniscus. Because of their location and configuration, meniscal tears associated with an anterior cruciate ligament injury are more difficult to detect on MR images than are tears in knees with an intact ligament. If a tear of the anterior cruciate ligament is detected, special attention should be given to the subtle peripheral tears that may be present in either meniscus, but most commonly in the posterior horn of the lateral meniscus. These tears are especially difficult to detect on MR images.

An Intact Anterior Cruciate Ligament at the Time of Posterior Cruciate Ligament-Retaining Total Knee Arthroplasty Was Associated With Reduced Patient Satisfaction and Inferior Pain and Stair Function.

PubMed

Jacobs, Cale A; Christensen, Christian P; Karthikeyan, Tharun

2016-08-01

Patients with an intact anterior cruciate ligament (ACL) at the time of ACL-sacrificing total knee arthroplasty (TKA) have been suggested to have inferior outcomes compared with those with a dysfunctional ACL. However, to date, no published clinical studies have evaluated the potential link between the condition of the ACL at the time of posterior cruciate ligament-retaining TKA and postoperative pain, function, and satisfaction. As such, the purpose of this study was to compare subjective function, movement-elicited pain, pain at rest, and patient satisfaction between those with an intact or dysfunctional ACL. We identified 562 posterior cruciate ligament-retaining TKAs with complete intraoperative and postoperative data. Patients were categorized based on the condition of the ACL at the time of TKA as either being intact or dysfunctional (absent or lax). Knee Society Function Scores, movement-elicited pain, pain at rest, and patient satisfaction were then compared between groups. At mean follow-up of 5.1 years, a significantly lower proportion of patients in the intact group were satisfied with their operation (intact: 391/453 [86.3%] vs dysfunctional: 102/109 [93.6%], P = .0496). Inspection of the individual activities revealed that the groups did not differ in walking ability or pain when walking; however, the intact group reported significantly reduced ability to navigate stairs with greater pain during that activity. The lack of difference in pain at rest between groups suggests that pain and functional impairments during more demanding activities such as navigating stairs may be associated with the lost function of the ACL rather than by altered central pain processing. Copyright © 2016 Elsevier Inc. All rights reserved.

[Effect of epidermal growth factor and testosterone on androgen receptor activation in urethral plate fibroblasts in hypospadias].

PubMed

Lin, Junshan; Xie, Cheng; Chen, Ruiqing; Li, Dumiao

2016-05-01

To investigate androgen receptor (AR) expression and the effect of epidermal growth factor (EGF) and testosterone on AR expression level.
 EGF or different concentrations of testosterone were incubated with the primary urethral plate fibroblasts from patients with hypospadias. The levels of AR expression in the fibroblasts were detected by immunocytochemical assays and graphical analysis.
 There was no significant difference in AR activation under physiological concentrations (3×10(-8) mol/L) of testosterone between the control and the distal hypospadias group (P>0.05). However, there was a significant decrease in AR activation in the proximal hypospadias group compared to that in the control group (P<0.001). Under the concentration of 3×10(-6) mol/L, the effects of testosterone on AR activation were dramatically different in the three groups (control group>distal hypospadias group>proximal hypospadias group, P<0.001). AR activation level in the group of proximal hypospadias was improved most obviously when EGF and physiological concentration of testosterone were employed in the urethral plate fibroblasts from hypospadias patients (P<0.001), and it was improved more in the distal hypospadias group than that in the control group (P=0.02).
 AR expression and activation in the urethral plate fibroblasts from hypospadias patients are abnormal. EGF can be used to improve AR activation in fibroblasts from different types of hypospadias, especially in the proximal type.

Aetiology and pathogenesis of cranial cruciate ligament rupture in cats by histological examination.

PubMed

Wessely, Marlis; Reese, Sven; Schnabl-Feichter, Eva

2017-06-01

Objectives The aim of this study was to examine histologically intact and ruptured cranial cruciate ligaments in cats, in order to evaluate whether degeneration is a prerequisite for rupture. Methods We performed a histological examination of 50 intact and 19 ruptured cranial cruciate ligaments in cadaver or client-owned cats, respectively, using light microscopy. Cats with stifle pathology were further divided into five age groups in order to investigate the relationship of changes in the ligament with lifespan. Cats with ruptured cranial cruciate ligaments were divided into two groups according to medical history (with presumed history of trauma or without any known history of trauma) in order to investigate the relationship of ligament rupture with a traumatic event. Data from 200 healthy cats were selected randomly and reviewed to make a statistical comparison of cats with and without cranial cruciate ligament rupture (reference group). Results On histological examination, the intact cranial cruciate ligaments showed basic parallel arrangement of the collagen fibres, with no relation to age. While cats of a more advanced age showed fibrocartilage in the middle of the cranial cruciate ligament - a likely physiological reaction to compression forces over the lifespan - degenerative changes within the fibrocartilage were absent in all cases, regardless of age or rupture status. Cats suffering from cranial cruciate ligament rupture without history of trauma were significantly older than cats in the reference group. Conclusions and relevance This study showed that differentiation of fibrocartilage in the middle of the cranial cruciate ligament is likely a physiological reaction to compressive forces and not a degenerative change associated with greater risk of rupture in advanced age. This finding in cats is distinct from the known decrease in differentiation of fibrocartilage in dogs with cranial cruciate ligament rupture. Furthermore, the histological examination of cats revealed no other signs of degeneration in the cranial cruciate ligaments. Thus, degeneration is likely not an aetiological factor for cranial cruciate ligament rupture in cats.

Ligament-induced sacral fractures of the pelvis are possible.

PubMed

Steinke, Hanno; Hammer, Niels; Lingslebe, Uwe; Höch, Andreas; Klink, Thomas; Böhme, Jörg

2014-07-01

Pelvic ring stability is maintained passively by both the osseous and the ligamentous apparatus. Therapeutic approaches focus mainly on fracture patterns, so ligaments are often neglected. When they rupture along with the bone after pelvic ring fractures, disrupting stability, ligaments need to be considered during reconstruction and rehabilitation. Our aim was to determine the influence of ligaments on open-book injury using two experimental models with body donors. Mechanisms of bone avulsion related to open-book injury were investigated. Open-book injuries were induced in human pelves and subsequently investigated by anatomical dissection and endoscopy. The findings were compared to CT and MRI scans of open-book injuries. Relevant structures were further analyzed using plastinated cross-sections of the posterior pelvic ring. A fragment of the distal sacrum was observed, related to open-book injury. Two ligaments were found to be responsible for this avulsion phenomenon: the caudal portion of the anterior sacroiliac ligament and another ligament running along the ventral surface of the third sacral vertebra. The sacral fragment remained attached to the coxal bone by this second ligament after open-book injury. These results were validated using plastination and the structures were identified. Pelvic ligaments are probably involved in sacral avulsion caused by lateral traction. Therefore, ligaments should to be taken into account in diagnosis of open-book injury and subsequent therapy. Copyright © 2014 Wiley Periodicals, Inc.

A stress MRI of the shoulder for evaluation of ligamentous stabilizers in acute and chronic acromioclavicular joint instabilities.

PubMed

Izadpanah, Kaywan; Winterer, Jan; Vicari, Marco; Jaeger, Martin; Maier, Dirk; Eisebraun, Leonie; Ute Will, Jutta; Kotter, Elmar; Langer, Mathias; Südkamp, Norbert P; Hennig, Jürgen; Weigel, Mathias

2013-06-01

To show the feasibility of a stress magnetic resonance imaging (MRI) as a new method for simultaneous evaluation of the morphology and the functional integrity of the acromioclavicular joint (ACJ) ligamentous stabilizers. MRI of four volunteers, 10 patients with acute, and six with chronic ACJ injuries was performed using a 0.25 T open MRI scanner. A 2D-proton-density and a 3D-gradient-echo sequence at rest and under 6.5 kg shoulder traction were performed. Comparative measurements of the coracoclavicular and the acromioclavicular distance were performed. Additionally, the conoid and trapezoid ligament lengths were measured with multiplanar reconstructions. MRI at rest correctly identified tears of the coracoclavicular and the acromioclavicular ligaments in eight patients suffering acute ACJ injuries. Stress application helped to distinguish between partial and complete coracoclavicular ligament tears in two cases. Insufficiency of the ACJ ligaments was present in all acute and chronic ACJ injuries. Stress application in chronic ACJ ligaments revealed isolated insufficiency of the conoid ligament in three cases and of the trapezoid ligament in one case. Combined insufficiency was present in two cases. Stress MRI facilitates simultaneous acquisition of morphologic and functional information of the ACJ stabilizers. In acute ACJ injuries it helps to distinguish between partial and complete ligament tears. In chronic ACJ injuries it provides functional information of the ligament regrinds. Copyright © 2012 Wiley Periodicals, Inc.

Arthroscopic and magnetic resonance image appearance and reconstruction of the anterior talofibular ligament in cases of apparent functional ankle instability.

PubMed

Takao, Masato; Innami, Ken; Matsushita, Takashi; Uchio, Yuji; Ochi, Mitsuo

2008-08-01

Many patients report feeling functional ankle instability, despite having no clinically demonstrable lateral instability. Some patients who experience functional instability of the ankle have substantial abnormalities of the anterior talofibular ligament despite having apparently normal lateral laxity in clinical examination. Case series; Level of evidence, 4. Fourteen patients who had functional ankle instability after sprain, despite having no clinically demonstrable lateral instability, were included in this study. All subjects underwent standard stress radiography, magnetic resonance imaging, and ankle arthroscopy. These patients were treated with anatomical reconstruction of the anterior talofibular ligament. Arthroscopic assessment revealed 3 cases with no ligamentous structure with scar tissue, 9 cases with partial ligament tears and scar tissue on the disrupted anterior talofibular ligament fiber, and 2 cases of abnormal course of the ligament at the fibular or talar attachment. Magnetic resonance imaging revealed the following: 5 cases of discontinuity of the anterior talofibular ligament, 2 cases of narrowing of the anterior talofibular ligament, 4 cases of high-intensity lesion in the anterior talofibular ligament, and 3 normal cases. The mean American Orthopaedic Foot and Ankle Society Ankle Hindfoot scale score was 66.2 +/- 3.2 points at preoperation and 92.3 +/- 4.4 points 2 years after surgery. All patients in this study with functional ankle instability, despite their having no demonstrable abnormal lateral laxity, had morphologic ligamentous abnormality on arthroscopic assessment.

Ankle Arthroscopic Reconstruction of Lateral Ligaments (Ankle Anti-ROLL)

PubMed Central

Takao, Masato; Glazebrook, Mark; Stone, James; Guillo, Stéphane

2015-01-01

Ankle instability is a condition that often requires surgery to stabilize the ankle joint that will improve pain and function if nonoperative treatments fail. Ankle stabilization surgery may be performed as a repair in which the native existing anterior talofibular ligament or calcaneofibular ligament (or both) is imbricated or reattached. Alternatively, when native ankle ligaments are insufficient for repair, a reconstruction of the ligaments may be performed in which an autologous or allograft tendon is used to reconstruct the anterior talofibular ligament or calcaneofibular ligament (or both). Currently, ankle stabilization surgery is most commonly performed through an open incision, but arthroscopic ankle stabilization using repair techniques has been described and is being used more often. We present our technique for anatomic ankle arthroscopic reconstruction of the lateral ligaments (anti-ROLL) performed in an all–inside-out manner that is likely safe for patients and minimally invasive. PMID:26900560

[Calcaneo-fibular ligament surgery for chronic lateral instability of the upper ankle : Broström technique with modification by Wille. Video article].

PubMed

Kosiol, J; Wille, M; Putzer, D; Biedermann, R

2015-11-01

An acute ligament rupture of the lateral ligament complex of the ankle joint is treated without surgery. Treatment failure may lead to a chronically unstable situation of the ankle joint, in which case surgery is an effective procedure for stabilizing the ruptured ligaments. Anatomical reconstruction is the best operative technique if the ligament tissue is of good quality. In our video we demonstrate a new possibility for the positioning of an anchor to tighten the calcaneo-fibular ligament. Modified Broström repairs are described in the literature in which the calcaneo-fibular ligament is released and reattached to the fibula to tighten it. We present the option to release the ligament at the calcaneus and reattach it using a suture anchor. This offers the advantage of preventing the possible dislocation of the peroneal tendons.

Lipopolysaccharide and hypoxia significantly alters interleukin-8 and macrophage chemoattractant protein-1 production by human fibroblasts but not fibrosis related factors.

PubMed

Eleftheriadis, T; Liakopoulos, V; Lawson, B; Antoniadi, G; Stefanidis, I; Galaktidou, G

2011-07-01

Besides extracellular matrix production, fibroblasts are able to produce various cytokines. Their ubiquitous position makes fibroblasts appropriate cells for sensing various noxious stimuli and for attracting immune cells in the affected area. In the present study the effect of lipopolysaccharide (LPS) and cobalt chloride (CoCl(2)) on the above fibroblasts functions were evaluated in primary human skin fibroblasts cultures. Collagen, matrix metalloproteinase-1, tissue inhibitor of metalloproteinases-1, transforming growth factor-β1, interleukin-8 (IL-8) and macrophage chemoattractant protein-1 (MCP-1) were measured in fibroblasts culture supernatants. Fibroblasts proliferation and viability were assessed as well. Hypoxia inducible factor-1α and the phosphorylated p65 portion of NF-κB were assessed in fibroblasts protein extracts. LPS and CoCl(2) had a minor effect on fibrosis related factors in human primary fibroblasts, possibly due to the absence of interplay with other cell types in the used experimental system. On the contrary both LPS and CoCl(2) increased significantly IL-8. LPS also increased considerably MCP-1, but CoCl(2) decreased it. Thus LPS and CoCl(2) induce a sentinel, nevertheless not identical, phenotype in primary human fibroblasts. The last disparity could result in different body response to infectious or hypoxic noxious stimuli.

Multiple functions of gingival and mucoperiosteal fibroblasts in oral wound healing and repair.

PubMed

Chiquet, Matthias; Katsaros, Christos; Kletsas, Dimitris

2015-06-01

Fibroblasts are cells of mesenchymal origin. They are responsible for the production of most extracellular matrix in connective tissues and are essential for wound healing and repair. In recent years, it has become clear that fibroblasts from different tissues have various distinct traits. Moreover, wounds in the oral cavity heal under very special environmental conditions compared with skin wounds. Here, we reviewed the current literature on the various interconnected functions of gingival and mucoperiosteal fibroblasts during the repair of oral wounds. The MEDLINE database was searched with the following terms: (gingival OR mucoperiosteal) AND fibroblast AND (wound healing OR repair). The data gathered were used to compare oral fibroblasts with fibroblasts from other tissues in terms of their regulation and function during wound healing. Specifically, we sought answers to the following questions: (i) what is the role of oral fibroblasts in the inflammatory response in acute wounds; (ii) how do growth factors control the function of oral fibroblasts during wound healing; (iii) how do oral fibroblasts produce, remodel and interact with extracellular matrix in healing wounds; (iv) how do oral fibroblasts respond to mechanical stress; and (v) how does aging affect the fetal-like responses and functions of oral fibroblasts? The current state of research indicates that oral fibroblasts possess unique characteristics and tightly controlled specific functions in wound healing and repair. This information is essential for developing new strategies to control the intraoral wound-healing processes of the individual patient. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of human umbilical cord blood-derived mesenchymal stem cells with healthy fibroblasts on wound-healing activity of diabetic fibroblasts.

PubMed

Jung, Jae-A; Yoon, Young-Don; Lee, Hyup-Woo; Kang, So-Ra; Han, Seung-Kyu

2018-02-01

Various types of skin substitutes composed of fibroblasts and/or keratinocytes have been used for the treatment of diabetic ulcers. However, the effects have generally not been very dramatic. Recently, human umbilical cord blood-derived mesenchymal stromal cells (hUCB-MSCs) have been commercialised for cartilage repair as a first cell therapy product using allogeneic stem cells. In a previous pilot study, we reported that hUCB-MSCs have a superior wound-healing capability compared with fibroblasts. The present study was designed to compare the treatment effect of hUCB-MSCs with that of fibroblasts on the diabetic wound healing in vitro. Diabetic fibroblasts were cocultured with healthy fibroblasts or hUCB-MSCs. Five groups were evaluated: group I, diabetic fibroblasts without coculture; groups II and III, diabetic fibroblasts cocultured with healthy fibroblasts or hUCB-MSCs; and groups IV and V, no cell cocultured with healthy fibroblasts or hUCB-MSCs. After a 3-day incubation, cell proliferation, collagen synthesis levels and glycosaminoglycan levels, which are the major contributing factors in wound healing, were measured. As a result, a hUCB-MSC-treated group showed higher cell proliferation, collagen synthesis and glycosaminoglycan level than a fibroblast-treated group. In particular, there were significant statistical differences in collagen synthesis and glycosaminoglycan levels (P = 0·029 and P = 0·019, respectively). In conclusion, these results demonstrate that hUCB-MSCs may have a superior effect to fibroblasts in stimulating diabetic wound healing. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Characterization and role of the immune response during ligament healing

NASA Astrophysics Data System (ADS)

Chamberlain, Connie S.

Scar formation of ligaments after rupture remains a great challenge. Ligament healing involves a complex, coordinated series of events that form a neo-ligament, which is more disorganized and fibrotic in character than the native tissue. The repair process may extend from months to years, and the injured ligament never fully recovers its original mechanical properties. With little intrinsic healing potential, ruptures of the anterior cruciate ligament (ACL) are usually reconstructed. The "healed" tissues, however, do not regenerate native tissues or recapitulate their mechanical function. ACL grafts often lengthen (incidents range from 40-100%) and their strength can drop by ˜50% after remodeling. Reconstructed knees are often less stable and fail to restore normal joint kinematics. Our overall goal is to improve healing, making ligaments more regenerative. The first 2 studies characterized ligament healing in a spatial and temporal manner over 28 days. The experiments demonstrated creeping substitution and the potential role of the immune system to control the repair and/or regenerative process. From these studies, macrophages were identified as significant players during healing. Macrophages paralleled creeping substitution, were abundant within the healing ligament, and potentially played a destructive role via matrix phagocytosis. The role of macrophages during early ligament healing was then evaluated using liposome-encapsulated clodronate to inhibit phagocytosing macrophages. Clodronate attenuated the early infiltration of macrophages, resulting in delayed structural and functional healing. Macrophage re-infiltration into the wound resulted in continued ligament healing. These results suggested that early inhibition of phagocytosing macrophages is detrimental to ligament healing. The final experiment evaluated the effects of interleukin-4 on ligament healing. Interleukin-4 (IL-4) is reported to stimulate the Th2 lymphocyte/M2 macrophage pathway, reducing inflammation and stimulating remodeling. IL-4 dose- and time-dependently stimulated early ligament regeneration but was unable to maintain the response during later healing. In summary, this work demonstrated the association between the immune cells and ligament healing, indicating a potential for obtaining a more regenerative response by modulating the immune response in a time, dose, and spatial manner.

The Epidemiology of Deltoid Ligament Sprains in 25 National Collegiate Athletic Association Sports, 2009–2010 Through 2014–2015 Academic Years

PubMed Central

Kopec, Thomas J.; Hibberd, Elizabeth E.; Roos, Karen G.; Djoko, Aristarque; Dompier, Thomas P.; Kerr, Zachary Y.

2017-01-01

Context: Deltoid ligament sprains among collegiate student-athletes have not been extensively investigated. Research regarding the mechanisms, participation-restriction time, and recurrence of deltoid ligament sprains in collegiate student-athletes is lacking. Objective: To describe the epidemiology of deltoid ligament sprains in 25 National Collegiate Athletic Association championship sports. Design: Descriptive epidemiology study. Setting: National Collegiate Athletic Association Injury Surveillance Program. Main Outcome Measure(s): We analyzed deltoid ligament sprains recorded in the Injury Surveillance Program for the 2009–2010 through 2014–2015 academic years. Deltoid ligament sprain injury rates, rate ratios, and injury proportion ratios with 95% confidence intervals (CIs) were reported. Results: During the study period, 380 deltoid ligament sprains were reported, resulting in a combined injury rate of 0.79/10 000 athlete-exposures (AEs; 95% CI = 0.71, 0.87). Most deltoid ligament sprains occurred in practices (54.2%, n = 206). However, the competition injury rate was higher than the practice injury rate (rate ratio = 3.74; 95% CI = 3.06, 4.57). The highest deltoid ligament sprain rates were in women's gymnastics (2.30/10 000 AEs; 95% CI = 1.05, 3.55), men's soccer (1.73/10 000 AEs; 95% CI = 1.14, 2.32), women's soccer (1.61/10 000 AEs; 95% CI = 1.13, 2.09), and men's football (1.40/10 000 AEs; 95% CI = 1.18, 1.62). Nearly half of all deltoid ligament sprains (49.7%, n = 189) were due to player contact, and 39.5% (n = 150) were non–time-loss injuries (ie, participation restricted for less than 24 hours). Only 8.2% (n = 31) of deltoid ligament sprains were recurrent. Conclusions: The highest deltoid ligament sprain rates were in women's gymnastics, men's and women's soccer, and men's football. However, the rate for women's gymnastics was imprecise (ie, the CI was wide), highlighting the need for further surveillance of deltoid ligament sprains in the sport. Most deltoid ligament sprains were due to player contact. Future researchers should assess interventions that may prevent deltoid ligament sprains. PMID:28318315

In Vitro Effects of Pirfenidone on Cardiac Fibroblasts: Proliferation, Myofibroblast Differentiation, Migration and Cytokine Secretion

PubMed Central

Shi, Qiang; Liu, Xiaoyan; Bai, Yuanyuan; Cui, Chuanjue; Li, Jun; Li, Yishi; Hu, Shengshou; Wei, Yingjie

2011-01-01

Cardiac fibroblasts (CFs) are the primary cell type responsible for cardiac fibrosis during pathological myocardial remodeling. Several studies have illustrated that pirfenidone (5-methyl-1-phenyl-2-[1H]-pyridone) attenuates cardiac fibrosis in different animal models. However, the effects of pirfenidone on cardiac fibroblast behavior have not been examined. In this study, we investigated whether pirfenidone directly modulates cardiac fibroblast behavior that is important in myocardial remodeling such as proliferation, myofibroblast differentiation, migration and cytokine secretion. Fibroblasts were isolated from neonatal rat hearts and bioassays were performed to determine the effects of pirfenidone on fibroblast function. We demonstrated that treatment of CFs with pirfenidone resulted in decreased proliferation, and attenuated fibroblast α-smooth muscle actin expression and collagen contractility. Boyden chamber assay illustrated that pirfenidone inhibited fibroblast migration ability, probably by decreasing the ratio of matrix metalloproteinase-9 to tissue inhibitor of metalloproteinase-1. Furthermore, pirfenidone attenuated the synthesis and secretion of transforming growth factor-β1 but elevated that of interleukin-10. These direct and pleiotropic effects of pirfenidone on cardiac fibroblasts point to its potential use in the treatment of adverse myocardial remodeling. PMID:22132230

The Effects of Generalized Joint Laxity on Risk of Anterior Cruciate Ligament Injury in Young Female Athletes

PubMed Central

Myer, Gregory D.; Ford, Kevin R.; Paterno, Mark V.; Nick, Todd G.; Hewett, Timothy E.

2012-01-01

Background Women who participate in high-risk sports suffer anterior cruciate ligament injury at a 4- to 6-fold greater rate than men. Purpose To prospectively determine if female athletes with decreased passive knee joint restraint (greater joint laxity) and greater side-to-side differences in knee laxity would be at increased risk of anterior cruciate ligament injury. Study Design Case control study; Level of evidence, 3. Methods From 1558 female soccer and basketball players who were prospectively screened, 19 went on to tear their anterior cruciate ligaments. Four height- and mass-matched control subjects were selected from the uninjured screened athletes for comparison with each of the 19 injured subjects, making a total of 95 subjects (19 injured; 76 uninjured). Generalized joint-laxity tests and anterior-posterior tibiofemoral translation were quantified using the CompuKT knee arthrometer. A multivariable logistic regression model was constructed to determine predictors of anterior cruciate ligament injury status from recorded laxity measures. Results A multivariable logistic regression model (chi-square = 18.6; P = .002) used the independent variables laxity measures of knee hyperextension (P = .02), wrist and thumb to forearm opposition (P = .80), fifth-finger hyperextension >90° (P = .71), side-to-side differences in anterior-posterior tibiofemoral translation (P = .002), and prior knee injury (P = .22) to predict anterior cruciate ligament–injury status. The validated C statistic, or validated area under the receiver operating characteristic curve, was 0.72. For every 1.3-mm increase in side-to-side differences in anterior-posterior knee displacement, the odds of anterior cruciate ligament–injured status increased 4-fold (95% confidence interval, 1.68–9.69). A positive measure of knee hyperextension increased the odds of anterior cruciate ligament–injured status 5-fold (95% confidence interval, 1.24–18.44). Conclusion The current results indicate that increased knee-laxity measures may contribute to increased risk of anterior cruciate ligament injury. The methods to quantify knee joint laxity in this report may be used in conjunction with measures of neuromuscular control of the knee joint to identify high-risk female athletes with high accuracy. Once high-risk female athletes are identified, they may be targeted to the appropriate interventions to reduce injury risk. PMID:18326833

Association of polymorphisms rs1800012 in COL1A1 with sports-related tendon and ligament injuries: a meta-analysis

PubMed Central

Wang, Chunguang; Li, Hao; Chen, Kang; Wu, Bing; Liu, Haifeng

2017-01-01

It has been reported that the single nucleotide polymorphism (SNP) rs1800012 in COL1A1 might be associated with the susceptibility to sports-related tendon and ligament injuries such as ACL injuries, Achilles tendon injuries, shoulder dislocations and tennis elbow. But the data from different studies have been conflicting. Here we attempted to systematically summarize and clarify the association between the SNP and sports-related tendon and ligament injuries risk. Six eligible studies including 933 cases and 1,381 controls were acquired from PubMed, Web Of Science and Cochrane library databases. Significant association was identified in homozygote model (TT versus GG: OR=0.17, 95%CI 0.08-0.35, PH=0.00) and recessive model (TT versus GT/GG: OR=0.21, 95%CI 0.10-0.44, PH=0.00). Our results indicated that COL1A1 rs1800012 polymorphism may be associated with the reduced risk of sports-related tendon or ligament injuries, especially in ACL injuries, and that rare TT may played as a protective role. PMID:28206959

Endoscopic Excision of Supracondylar Humeral Spur for Decompression of the Median Nerve and Brachial Artery.

PubMed

Bain, Gregory; Gupta, Prince; Phadnis, Joideep; Singhi, Prahalad K

2016-02-01

The humeral supracondylar process and Struthers ligament comprise a relatively rare but well-known anatomic variant. They are usually asymptomatic but may produce clinical symptoms related to compression of the median nerve or brachial artery below the ligament. Previously, surgery has been performed with an open ligament release and supracondylar process excision. This article reports on the use of endoscopic findings and the method of ligament release and process excision. Endoscopy is a minimally invasive technique that provides excellent visualization and enables the surgeon to perform dissection with magnification and precision. It allows the surgeon to introduce open surgical techniques into the depths of the wound in a controlled manner. Because of the dead space created, there is a risk of hematoma formation. Many of the concepts used in open surgery are now being used for endoscopic surgery, and vice versa. The barriers and differences among endoscopic, arthroscopic, and open procedures are being broken down. We report another endoscopic technique, which is part of the ongoing evolution of musculoskeletal surgery.

Proteomic Analysis of Human Tendon and Ligament: Solubilization and Analysis of Insoluble Extracellular Matrix in Connective Tissues.

PubMed

Sato, Nori; Taniguchi, Takako; Goda, Yuichiro; Kosaka, Hirofumi; Higashino, Kosaku; Sakai, Toshinori; Katoh, Shinsuke; Yasui, Natsuo; Sairyo, Koichi; Taniguchi, Hisaaki

2016-12-02

Connective tissues such as tendon, ligament and cartilage are mostly composed of extracellular matrix (ECM). These tissues are insoluble, mainly due to the highly cross-linked ECM proteins such as collagens. Difficulties obtaining suitable samples for mass spectrometric analysis render the application of modern proteomic technologies difficult. Complete solubilization of them would not only elucidate protein composition of normal tissues but also reveal pathophysiology of pathological tissues. Here we report complete solubilization of human Achilles tendon and yellow ligament, which is achieved by chemical digestion combined with successive protease treatment including elastase. The digestion mixture was subjected to liquid chromatography-mass spectrometry. The low specificity of elastase was overcome by accurate mass analysis achieved using FT-ICR-MS. In addition to the detailed proteome of both tissues, we also quantitatively determine the major protein composition of samples, by measuring peak area of some characteristic peptides detected in tissue samples and in purified proteins. As a result, differences between human Achilles tendon and yellow ligament were elucidated at molecular level.

Morphologic and functional features of the canine cruciate ligaments.

PubMed

de Rooster, Hilde; de Bruin, Tanya; van Bree, Henri

2006-12-01

To review the gross, microscopic, and functional anatomy of the cranial cruciate ligament (CCL) in dogs. Literature review. Reports of the anatomy and function of the cruciate ligaments in dogs were retrieved by search of the 1975-2005 PubMed database. The CCL has an important biomechanical function resisting cranial drawer, hyperextension, and internal rotation and acts to fine tune and guide the stifle through its rolling and sliding motion. It has a complex architecture, and distinct geographic regions within the ligament have different functional roles depending on the angle and loading conditions. Collagen type I is the main component of the extracellular matrix; the fibrils have a crimped structure. The cruciate ligaments are almost completely covered by synovium, protecting them from synovial fluid. Cruciate blood supply is mainly of soft tissue origin. The intraligamentous network is relatively limited whereas the core of the middle third of the CCL is even less well vascularized. Neurohistologic studies are very limited in the dog. Various mechanoreceptors and proprioceptive receptors have been identified within the substance of the cruciate ligaments. CCL structural characteristics play an important part in its complex behaviour with the crimped pattern of the collagen fibrils being an important determinant of its biomechanical properties. In contrast to reports of managing CCL rupture, there are few reports describing the microanatomy and neurovascular morphology of the cruciate ligaments. Cruciate disease is likely multi-factorial. Improved understanding of CCL degradation leading to CCL rupture is critical to development of new diagnostic tests for cruciate disease in dogs. Appropriate intervention during the early stages of disease process might preserve CCL structural properties by preventing further collagen degradation. Accurate knowledge of functional and fiber bundle anatomy is imperative for reconstruction and restoration of normal stifle joint physiology. Reconstructive goals should alleviate existing instability and mimic normal kinematics. Knowledge of the exact function of the CCL in the neuromuscular control around the stifle joint could possibly explain osteoarthritis progression after CCL damage.

Effect of the Distal Femoral Joint Line on Ligament Tensions in Flexion with Cruciate-Retaining Total Knee Prostheses.

PubMed

Narayanan, Rajkishen; Lenz, Nathaniel; Werner, Jordan Alexander; Cross, Michael B; Hughes, Dean; Laster, Scott; Schwarzkopf, Ran

2018-04-13

Proper ligament tension in knee flexion within cruciate-retaining (CR) total knee arthroplasty has long been associated with clinical success; however, traditional balancing principles have assumed that the distal femoral joint line (DFJL) affects only extension. The purpose of this study was to determine the effect DFJL may have on ligament strains and tibiofemoral kinematics of CR knee designs in flexion. A computational analysis was performed using a musculoskeletal modeling system for two different knee implants, the high-flex CR (HFCR) and guided-motion CR (GMCR). Tibiofemoral kinematics and ligament strain were measured at 90-degree knee flexion while the implants' DFJL was incrementally shifted proximally. Femoral implant position and kinematics were used to determine the femur's anteroposterior position relative to the tibia. The change in the femoral medial condyle position relative to the tibia was 0.33 mm and 0.53 mm more anterior per each 1-mm elevation of the DFJL for HFCR and GMCR, respectively. The change in the lateral condyle position was 0.20 mm more anterior and 0.06 mm more posterior for HFCR and GMCR, respectively. The strain in the lateral and medial collateral ligaments changed minimally with elevation of the DFJL. In both implants, strain increased in the anterior lateral and posterior medial bundles of the posterior collateral ligament with elevation of the DFJL, whereas strain decreased in the iliotibial band and iliotibial patellar band. Our findings suggest that DFJL affects ligament tension at 90-degree knee flexion and therefore flexion balance for CR implants. Elevating the DFJL to address tight extension space in a CR knee while flexion space is well balanced could result in increased flexion tension especially when the flexion-extension mismatch is large. To achieve balanced flexion and extension, the amount of DFJL elevation may need to be reduced. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Reference Values for the Marx Activity Rating Scale in a Young Athletic Population: History of Knee Ligament Injury Is Associated With Higher Scores.

PubMed

Cameron, Kenneth L; Peck, Karen Y; Thompson, Brandon S; Svoboda, Steven J; Owens, Brett D; Marshall, Stephen W

2015-01-01

Activity-related patient-reported outcome measures are an important component of assessment after knee ligament injury in young and physically active patients; however, normative data for most activity scales are limited. To present reference values by sex for the Marx Activity Rating Scale (MARS) within a young and physically active population while accounting for knee ligament injury history and sex. Cross-sectional study. Level 2. All incoming freshman entering a US Service Academy in June of 2011 were recruited to participate in this study. MARS was administered to 1169 incoming freshmen (203 women) who consented to participate within the first week of matriculation. All subjects were deemed healthy and medically fit for military service on admission. Subjects also completed a baseline questionnaire that asked for basic demographic information and injury history. We calculated means with standard deviations, medians with interquartile ranges, and percentiles for ordinal and continuous variables, and frequencies and proportions for dichotomous variables. We also compared median scores by sex and history of knee ligament injury using the Kruskal-Wallis test. MARS was the primary outcome of interest. The median MARS score was significantly higher for men when compared with women (χ(2) = 13.22, df = 1, P < 0.001) with no prior history of knee ligament injury. In contrast, there was no significant difference in median MARS scores between men and women (χ(2) = 0.47, df = 1, P = 0.493) who reported a history of injury. Overall, median MARS scores were significantly higher among those who reported a history of knee ligament injury when compared with those who did not (χ(2) = 9.06, df = 1, P = 0.003). Assessing activity as a patient-reported outcome after knee ligament injury is important, and reference values for these instruments need to account for the influence of prior injury and sex. © 2015 The Author(s).

Regional structural characteristics of bovine periodontal ligament samples and their suitability for biomechanical tests.

PubMed

Bosshardt, Dieter D; Bergomi, Marzio; Vaglio, Giovanna; Wiskott, Anselm

2008-03-01

Mechanical testing of the periodontal ligament requires a practical experimental model. Bovine teeth are advantageous in terms of size and availability, but information is lacking as to the anatomy and histology of their periodontium. The aim of this study, therefore, was to characterize the anatomy and histology of the attachment apparatus in fully erupted bovine mandibular first molars. A total of 13 teeth were processed for the production of undecalcified ground sections and decalcified semi-thin sections, for NaOH maceration, and for polarized light microscopy. Histomorphometric measurements relevant to the mechanical behavior of the periodontal ligament included width, number, size and area fraction of blood vessels and fractal analysis of the two hard-soft tissue interfaces. The histological and histomorphometric analyses were performed at four different root depths and at six circumferential locations around the distal and mesial roots. The variety of techniques applied provided a comprehensive view of the tissue architecture of the bovine periodontal ligament. Marked regional variations were observed in width, surface geometry of the two bordering hard tissues (cementum and alveolar bone), structural organization of the principal periodontal ligament connective tissue fibers, size, number and numerical density of blood vessels in the periodontal ligament. No predictable pattern was observed, except for a statistically significant increase in the area fraction of blood vessels from apical to coronal. The periodontal ligament width was up to three times wider in bovine teeth than in human teeth. The fractal analyses were in agreement with the histological observations showing frequent signs of remodeling activity in the alveolar bone - a finding which may be related to the magnitude and direction of occlusal forces in ruminants. Although samples from the apical root portion are not suitable for biomechanical testing, all other levels in the buccal and lingual aspects of the mesial and distal roots may be considered. The bucco-mesial aspect of the distal root appears to be the most suitable location.

Preventive lateral ligament tester (PLLT): a novel method to evaluate mechanical properties of lateral ankle joint ligaments in the intact ankle.

PubMed

Best, Raymond; Böhle, Caroline; Mauch, Frieder; Brüggemann, Peter G

2016-04-01

To construct and evaluate an ankle arthrometer that registers inversion joint deflection at standardized inversion loads and that, moreover, allows conclusions about the mechanical strain of intact ankle joint ligaments at these loads. Twelve healthy ankles and 12 lower limb cadaver specimens were tested in a self-developed measuring device monitoring passive ankle inversion movement (Inv-ROM) at standardized application of inversion loads of 5, 10 and 15 N. To adjust in vivo and in vitro conditions, the muscular inactivity of the evertor muscles was assured by EMG in vivo. Preliminary, test-retest and trial-to-trial reliabilities were tested in vivo. To detect lateral ligament strain, the cadaveric calcaneofibular ligament was instrumented with a buckle transducer. After post-test harvesting of the ligament with its bony attachments, previously obtained resistance strain gauge results were then transferred to tensile loads, mounting the specimens with their buckle transducers into a hydraulic material testing machine. ICC reliability considering the Inv-ROM and torsional stiffness varied between 0.80 and 0.90. Inv-ROM ranged from 15.3° (±7.3°) at 5 N to 28.3° (±7.6) at 15 N. The different tests revealed a CFL tensile load of 31.9 (±14.0) N at 5 N, 51.0 (±15.8) at 10 N and 75.4 (±21.3) N at 15 N inversion load. A highly reliable arthrometer was constructed allowing not only the accurate detection of passive joint deflections at standardized inversion loads but also reveals some objective conclusions of the intact CFL properties in correlation with the individual inversion deflections. The detection of individual joint deflections at predefined loads in correlation with the knowledge of tensile ligament loads in the future could enable more individual preventive measures, e.g., in high-level athletes.

To be Stiff or to be Soft-the Dilemma of the Echinoid Tooth Ligament. II. Mechanical Properties.

PubMed

Birenheide, R; Tsuchi, A; Motokawa, T

1996-04-01

The teeth of sea urchins are connected to jaws by means of ligaments. Their sliding along the jaw during continuous growth requires a pliant ligament, whereas scraping on rocks for feeding requires a stiff ligament for firm support. We investigated the mechanical properties of the tooth ligament of Diadema setosum to clarify how sea urchins solve this dilemma. In creep tests a load of 30 g caused a shift of the tooth that continued until the tooth was pulled out of the jaw. The creep curve had three phases: an initial phase of high creep rate, a long phase of constant creep rate, and a final phase of accelerating creep rate. The ligaments had a shear viscosity of about 550 MPa {middot} s. Viscosity increased reversibly after stimulation with seawater containing a high concentration of potassium ions or acetylcholine. Frozen and rethawed ligaments did not show an increase of viscosity after stimulation. The data indicate that sea urchins can change the stiffness of their tooth ligaments through nervous control. We suggest that the tooth ligament is a catch connective tissue.

[Application of silk-based tissue engineering scaffold for tendon / ligament regeneration].

PubMed

Hu, Yejun; Le, Huihui; Jin, Zhangchu; Chen, Xiao; Yin, Zi; Shen, Weiliang; Ouyang, Hongwei

2016-03-01

Tendon/ligament injury is one of the most common impairments in sports medicine. The traditional treatments of damaged tissue repair are unsatisfactory, especially for athletes, due to lack of donor and immune rejection. The strategy of tissue engineering may break through these limitations, and bring new hopes to tendon/ligament repair, even regeneration. Silk is a kind of natural biomaterials, which has good biocompatibility, wide range of mechanical properties and tunable physical structures; so it could be applied as tendon/ligament tissue engineering scaffolds. The silk-based scaffold has robust mechanical properties; combined with other biological ingredients, it could increase the surface area, promote more cell adhesion and improve the biocompatibility. The potential clinical application of silk-based scaffold has been confirmed by in vivo studies on tendon/ligament repairing, such as anterior cruciate ligament, medial collateral ligament, achilles tendon and rotator cuff. To develop novel biomechanically stable and host integrated tissue engineered tendon/ligament needs more further micro and macro studies, combined with product development and clinical application, which will give new hope to patients with tendon/ligament injury.

Effect of mitomycin C on keloid fibroblasts: an in vitro study.

PubMed

Simman, Richard; Alani, Hashim; Williams, Frances

2003-01-01

Keloids are the result of aberrant wound healing of human skin after dermal injury. Therapeutic options include excision followed by radiation therapy, steroid injection, and compression with silicone sheets among others. Local invasion and recurrence after excision has provoked interest in treating keloids as neoplasms. The purpose of this study was to determine the effect of mitomycin C (MMC) on keloid fibroblasts. Keloid fibroblasts obtained from five different patients were exposed to MMC. A control group of normal and keloid cells was treated with phosphate buffered saline only. Contrast microscopy showed a decrease of fibroblast density during the 3 weeks after exposure for normal and keloid fibroblasts relative to untreated fibroblasts. This was confirmed by total cell counts ( = 0.1) and measurement of DNA synthesis. By the third week, there was a recovery in DNA synthesis and increased cell count for some of the treated fibroblasts. We concluded that at an appropriate concentration, MMC shows proliferation of keloid fibroblasts in vitro for a period of 3 weeks. This agent may be considered in clinical trials after surgical excision of keloids.

Cell cycle synchronization and analysis of apoptosis-related gene in skin fibroblasts from domestic cat (Felis silvestris catus) and kodkod (Leopardus guigna).

PubMed

Veraguas, D; Gallegos, P F; Castro, F O; Rodriguez-Alvarez, L

2017-10-01

The kodkod population is in constant decrease and the somatic cell nuclear transfer (SCNT) might help to preserve the genetic pool of this species. The cell cycle synchronization of donor cells plays a crucial role in SCNT. The objective of this research was to evaluate two different methods for quiescence induction, serum starvation (SS) and contact inhibition (CI), both for 1, 3 and 5 days, on skin fibroblast from domestic cat and kodkod. Flow cytometry analysis revealed that in domestic cat, SS and CI, both at 3 and 5 days, increased the percentage of fibroblasts in G0/G1 compared to growing cells (GC) (p < .05). In kodkod, only SS for 3 and 5 days and CI for 1 and 3 days increased the percentage of fibroblasts in G0/G1 compared to GC (p < .05). Viability analysis by differential staining revealed that SS for 5 days decreased the proportion of live fibroblasts in domestic cat and kodkod (p < .05). Regarding gene expression analysis, in domestic cat fibroblasts, no differences were found in the BAX/BCL2 ratio in SS and CI (both at 1, 3 and 5 days) compared to GC. In kodkod fibroblasts, BAX/BCL2 ratio was increased in CI at 3 and 5 days compared to SS at 3 and 5 days (p < .05). In conclusion, in kodkod fibroblasts SS for 5 days and CI after 3 days might have a negative impact on cellular viability. According to these results, we suggest SS for 3 days for cell cycle synchronization in kodkod fibroblasts. © 2017 Blackwell Verlag GmbH.

Altered physiological functions and ion currents in atrial fibroblasts from patients with chronic atrial fibrillation.

PubMed

Poulet, Claire; Künzel, Stephan; Büttner, Edgar; Lindner, Diana; Westermann, Dirk; Ravens, Ursula

2016-02-01

The contribution of human atrial fibroblasts to cardiac physiology and pathophysiology is poorly understood. Fibroblasts may contribute to arrhythmogenesis through fibrosis, or by directly altering electrical activity in cardiomyocytes. The objective of our study was to uncover phenotypic differences between cells from patients in sinus rhythm (SR) and chronic atrial fibrillation (AF), with special emphasis on electrophysiological properties. We isolated fibroblasts from human right atrial tissue for patch-clamp experiments, proliferation, migration, and differentiation assays, and gene expression profiling. In culture, proliferation and migration of AF fibroblasts were strongly impaired but differentiation into myofibroblasts was increased. This was associated with a higher number of AF fibroblasts expressing functional Nav1.5 channels. Strikingly Na(+) currents were considerably larger in AF cells. Blocking Na(+) channels in culture with tetrodotoxin did not affect proliferation, migration, or differentiation in neither SR nor AF cells. While freshly isolated fibroblasts showed mostly weak rectifier currents, fibroblasts in culture developed outward rectifier K(+) currents of similar amplitude between the SR and AF groups. Adding the K(+) channel blockers tetraethylammonium and 4-aminopyridin in culture reduced current amplitude and inhibited proliferation in the SR group only. Analysis of gene expression revealed significant differences between SR and AF in genes encoding for ion channels, collagen, growth factors, connexins, and cadherins. In conclusion, this study shows that under AF conditions atrial fibroblasts undergo phenotypic changes that are revealed in culture. Future experiments should be performed in situ to understand the nature of those changes and whether they affect cardiac electrical activity. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Abscisic acid ameliorates the systemic sclerosis fibroblast phenotype in vitro

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

Bruzzone, Santina, E-mail: santina.bruzzone@unige.it; Centre of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV 9, 16132 Genova; Advanced Biotechnology Center, Largo Rosanna Benzi 10, 16132 Genova

Highlights: Black-Right-Pointing-Pointer ABA is an endogenous hormone in humans, regulating different cell responses. Black-Right-Pointing-Pointer ABA reverts some of the functions altered in SSc fibroblasts to a normal phenotype. Black-Right-Pointing-Pointer UV-B irradiation increases ABA content in SSc cultures. Black-Right-Pointing-Pointer SSc fibroblasts could benefit from exposure to ABA and/or to UV-B. -- Abstract: The phytohormone abscisic acid (ABA) has been recently identified as an endogenous hormone in humans, regulating different cell functions, including inflammatory processes, insulin release and glucose uptake. Systemic sclerosis (SSc) is a chronic inflammatory disease resulting in fibrosis of skin and internal organs. In this study, we investigated themore » effect of exogenous ABA on fibroblasts obtained from healthy subjects and from SSc patients. Migration of control fibroblasts induced by ABA was comparable to that induced by transforming growth factor-{beta} (TGF-{beta}). Conversely, migration toward ABA, but not toward TGF-{beta}, was impaired in SSc fibroblasts. In addition, ABA increased cell proliferation in fibroblasts from SSc patients, but not from healthy subjects. Most importantly, presence of ABA significantly decreased collagen deposition by SSc fibroblasts, at the same time increasing matrix metalloproteinase-1 activity and decreasing the expression level of tissue inhibitor of metalloproteinase (TIMP-1). Thus, exogenously added ABA appeared to revert some of the functions altered in SSc fibroblasts to a normal phenotype. Interestingly, ABA levels in plasma from SSc patients were found to be significantly lower than in healthy subjects. UV-B irradiation induced an almost 3-fold increase in ABA content in SSc cultures. Altogether, these results suggest that the fibrotic skin lesions in SSc patients could benefit from exposure to high(er) ABA levels.« less

Preclinical safety studies on autologous cultured human skin fibroblast transplantation.

PubMed

Zeng, Wei; Zhang, Shuying; Liu, Dai; Chai, Mi; Wang, Jiaqi; Zhao, Yuming

2014-01-01

Recently, FDA approved the clinical use of autologous fibroblasts (LAVIV™) for the improvement of nasolabial fold wrinkles in adults. The use of autologous fibroblasts for the augmentation of dermal and subcutaneous defects represents a potentially exciting natural alternative to the use of other filler materials for its long-term corrective ability and absence of allergic adverse effects proved by clinical application. However, compared to the clinical evidence, preclinical studies are far from enough. In this study, human skin-derived fibroblasts were cultured and expanded for both in vitro and in vivo observations. In vitro, the subcultured fibroblasts were divided into two groups. One set of cells underwent cell cycle and karyotype analysis at passages 5 and 10. The second group of cells was cocultured in medium with different concentrations of human skin extract D for the measurement of collagen concentration and cell count. In vivo, the subcultured fibroblasts were injected into nude mice subcutaneously. Biopsies were taken for morphology observation and specific collagen staining at 1, 2, and 3 months after injection. The results in vitro showed no significant differences in cell cycle distribution between passages 5 and 10. Cell proliferation and secretion were inhibited as the concentration of extract D increased. In vivo, the fibroblasts were remarkably denser on the experimental side with no dysplastic cells. Mitotic cells were easily observed at the end of the first month but were rare at the end of the third month. Type III collagen was detected at the end of the first month, while collagen type I was positive at the end of the second month. The content of both collagens increased as time passed. The above results indicated that the use of the autologous fibroblasts was safe, providing a basic support for clinical use of fibroblasts.

Rapid diagnosis of sensitivity to ultraviolet light in fibroblasts from dermatologic disorders, with particular reference to xeroderma pigmentosum

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

Cleaver, J.E.; Thomas, G.H.

1988-04-01

A rapid and simple method for determining the sensitivity of human fibroblasts to ultraviolet light is described. As an alternative to the colony formation assay, this method can be used for the rapid diagnosis of ultraviolet light sensitivity in fibroblasts from photosensitive disorders. The method is based on growth of small numbers of cells in 1-cm wells of culture trays for 4 or more days after irradiation and determination of cell survival by the incorporation of (/sup 3/H)hypoxanthine. D37 values (the dose at which 37% of the control level of incorporation remains) obtained from this procedure showed the same relativemore » sensitivity of normal and xeroderma pigmentosum fibroblasts as was obtained by colony formation. Untransformed and SV40-transformed fibroblasts, which have different growth rates and different responses to high cell densities, gave different D37 values by this assay in culture trays as compared with colony formation. Comparison of relative sensitivities to irradiation should therefore be made only between cell types with similar growth characteristics. The similar sensitivity of normal and xeroderma pigmentosum cells to mitomycin C was also determined by this culture tray method. By increasing cell density at the beginning of the experiments, a greater capacity of group C compared with group D fibroblasts for recovery from potentially lethal damage was also detected.« less

[Enhancement of wound healing by taspine and its effect on fibroblast].

PubMed

Dong, Yalin; He, Langchong; Chen, Fang

2005-07-01

To study the effect of taspine on enhancement of skin wound healing and its effect on fibroblast proliferation and autocrine. The plerosis effect of taspine on experimental skin wound was observed in vivo. Different concentrations of taspine were added in vitro and MTT technique was applied to observe its effect on fibroblast proliferation, the levels of transforming growth factor-beta1 (TGF-13P) and epidermal growth factor (EGF) were determined by ELISA. In vivo, exo-applied taspine 300 microg and 150 microg accelerated the recovery of skin wound. In vitro, 0.50-0.4 microg/ml taspine could increase autocrine of TGF-beta1and EGF by fibroblast, but it showed no effect on L929 fibroblast proliferation. Taspine enhances wound healing by increasing the autocrine of TGF-beta1 and EGF by fibroblast.

A mathematical model of forces in the knee under isometric quadriceps contractions.

PubMed

Huss, R A; Holstein, H; O'Connor, J J

2000-02-01

To predict the knee's response to isometric quadriceps contractions against a fixed tibial restraint.Design. Mathematical modelling of the human knee joint. Isometric quadriceps contraction is commonly used for leg muscle strengthening following ligament injury or reconstruction. It is desirable to know the ligament forces induced but direct measurement is difficult. The model, previously applied to the Lachmann or 'drawer' tests, combines an extensible fibre-array representation of the cruciate ligaments with a compressible 'thin-layer' representation of the cartilage. The model allows the knee configuration and force system to be calculated, given flexion angle, restraint position and loading. Inclusion of cartilage deformation increases relative tibio-femoral translation and decreases the ligament forces generated. For each restraint position, a range of flexion angles is found in which no ligament force is required, as opposed to a single flexion angle in the case of incompressible cartilage layers. Knee geometry and ligament elasticity are found to be the most important factors governing the joint's response to isometric quadriceps contractions, but cartilage deformation is found to be more important than in the Lachmann test. Estimation of knee ligament forces is important when devising exercise regimes following ligament injury or reconstruction. The finding of a 'neutral zone' of zero ligament force may have implications for rehabilitation of the ligament-injured knee.

Acute torn meniscus combined with acute cruciate ligament injury. Second look arthroscopy after 3-month conservative treatment.

PubMed

Ihara, H; Miwa, M; Takayanagi, K; Nakayama, A

1994-10-01

The purpose of this study was to evaluate arthroscopically the natural healing of an acute torn meniscus combined with an acute cruciate ligament injury treated nonoperatively. There were 30 lateral and 10 medial meniscus tears associated with 25 acute anterior cruciate ligament and 7 posterior cruciate ligament injuries in 32 patients. There was more than 1 tear on some menisci for a total of 51 tear sites. Injuries to the menisci and ligaments were allowed to heal without surgery, but were given protective mobilization immediately in order to stimulate stress oriented healing of injured collagen fibers and promote circulation of synovial fluid to the meniscus and ligament. A Kyuro knee brace with a coil spring traction system was used to add adequate but not excessive stress to the associated injured cruciate ligament. All knees were examined and arthroscoped before and after a 3-month treatment period. Results indicated that 69% of the lateral menisci healed completely and 18% healed partially, whereas 58% of the medial menisci healed completely and none healed partially. Twenty of 25 anterior cruciate ligaments and 3 of 7 posterior cruciate ligaments healed satisfactorily. This study indicated that acute tears of the meniscus, even when they occur in association with a cruciate ligament injury, can heal morphologically with nonsurgical treatment.

Altered chloride metabolism in cultured cystic fibrosis skin fibroblasts

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

Mattes, P.M.; Maloney, P.C.; Littlefield, J.W.

1987-05-01

An abnormal regulation of chloride permeability has been described for epithelial cells from patients with cystic fibrosis (CF). To learn more about the biochemical basis of this inherited disease, the authors have studied chloride metabolism in cultured CF fibroblasts by comparing the efflux of /sup 36/Cl/sup -/ from matched pairs of CF and normal fibroblasts. The rate constants describing /sup 36/Cl/sup -/ efflux did not differ between the two cell types, but in each of the four pairs tested the amount of /sup 36/Cl/sup -/ contained within CF cells was consistently reduced, by 25-30%, relative to normal cells. Comparisons ofmore » cell water content and /sup 22/Na/sup +/ efflux showed no differences between the two cell types, suggesting that overall intracellular chloride concentration is lower than normal in CF fibroblasts. Such data suggest that the CF gene defect is expressed in skin fibroblasts and that this defect may alter the regulation of intracellular Cl/sup -/ concentration, perhaps through changes in Cl/sup -/ permeability.« less

Outgrowth of fibroblast cells from goat skin explants in three different culture media and the establishment of cell lines.

PubMed

Singh, Mahipal; Sharma, Anil K

2011-02-01

Three different commercially available media, known to support human and porcine-specific fibroblast cultures, were tested for their growth potential on goat skin explants. Although outgrowth of fibroblasts was observed in all media tested, irrespective of breed, porcine-specific media exhibited higher rate of growth. Using this media, three fibroblast cell lines (GSF289, GSF737, and GSF2010) from ear skin explants of normal healthy dairy goats of Kiko and Saanen breed were successfully established in culture. Liquid nitrogen stocks of these frozen cells had a viability rate of 96.2% in in vitro cultures. These cells were morphologically indistinguishable from the cell stocks prior to freezing. Analysis of the growth of a fifth passage culture revealed an 'S' shaped growth curve with a population doubling time of 25 h. The cell lines were found negative for microbial, fungal, and mycoplasma contaminations. These goat skin fibroblast lines and the simple method of their isolation and freezing with high rate of viability will provide additional tools to study molecular mechanisms that regulate fibroblast function and for genetic manipulation of small ruminants.

Gonioscopy in the dog: inter-examiner variability and the search for a grading scheme.

PubMed

Oliver, J A C; Cottrell, B C; Newton, J R; Mellersh, C S

2017-11-01

To investigate inter-examiner variability in gonioscopic evaluation of pectinate ligament abnormality in dogs and to assess level of inter-examiner agreement for four different gonioscopy grading schemes. Two examiners performed gonioscopy in 98 eyes of 49 Welsh springer spaniel dogs and estimated the percentage circumference of iridocorneal angle affected by pectinate ligament abnormality to the nearest 5%. Percentage scores assigned to each eye by the two examiners were compared. Inter-examiner agreement was assessed following assignment of the percentage scores to each of four grading schemes by Cohen's kappa statistic. There was a strong positive correlation between the results of the two examiners (R=0·91). In general, Examiner 1 scored individual eyes higher than Examiner 2, especially for eyes in which both examiners diagnosed pectinate ligament abnormality. A "good" level of agreement could only be achieved with a gonioscopy grading scheme of no more than three categories and with a relatively large intermediate bandwidth (κ=0·68). A three-tiered grading scheme might represent an improvement on hereditary eye disease schemes which simply classify dogs to be either "affected" or "unaffected" for pectinate ligament abnormality. However, the large intermediate bandwidth of this scheme would only allow for the additional detection of those dogs with marked progression of pectinate ligament abnormality which would be considered most at risk of primary closed-angle glaucoma. © 2017 British Small Animal Veterinary Association.

Posterior medial meniscus root ligament lesions: MRI classification and associated findings.

PubMed

Choi, Ja-Young; Chang, Eric Y; Cunha, Guilherme M; Tafur, Monica; Statum, Sheronda; Chung, Christine B

2014-12-01

The purposes of this study were to determine the prevalence of altered MRI appearances of "posterior medial meniscus root ligament (PMMRL)" lesions, introduce a classification of lesion types, and report associated findings. We retrospectively reviewed 419 knee MRI studies to identify the presence of PMMRL lesions. Classification was established on the basis of lesions encountered. The medial compartment was assessed for medial meniscal tears in the meniscus proper, medial meniscal extrusion, insertional PMMRL osseous changes, regional synovitis, osteoarthritis, insufficiency fracture, and cruciate ligament abnormality. PMMRL abnormalities occurred in 28.6% (120/419) of the studies: degeneration, 14.3% (60/419) and tear, 14.3% (60/419). Our classification system included degeneration and tearing. Tearing was categorized as partial or complete with delineation of the point of failure as entheseal, midsubstance, or junction to meniscus. Of all tears, 93.3% (56/60) occurred at the meniscal junction. Univariate analysis revealed significant differences between the knees with and without PMMRL lesions in age, medial meniscal tear, medial meniscal extrusion, insertional PMMRL osseous change, regional synovitis, osteoarthritis, insufficiency fracture (p=0.017), and cruciate ligament degeneration (p<0.001). PMMRL lesions are commonly detected in symptomatic patients. We have introduced an MRI classification system. PMMRL lesions are significantly associated with age, medial meniscal tears, medial meniscal extrusion, insertional PMMRL osseous change, regional synovitis, osteoarthritis, insufficiency fracture, and cruciate ligament degeneration.

[Case-control study on transverse carpal ligament resection for the prevention of delayed carpal tunnel syndrome after distal radius fracture].

PubMed

Wang, Yan-jie; Wang, Shi-gang; Miao, Shu-juan; Su, Xia

2011-06-01

To investigate the effects of open reduction by palm side for the distal radius fracture and T shape plate internal fixation with simultaneous anterior transverse carpal ligament resection for the prevention of delayed carpal tunnel syndrome after operation. From March 2000 to March 2007, 32 patients (8 males and 24 females, ranging in age from 46 to 66 years) with distal radius fracture were treated with open reduction by palm side and T shape plate internal fixation with simultaneous anterior transverse carpal ligament resection; while 30 patients (7 males and 23 females,ranging in age from 45 to 65 years) only with open reduction by palm side and T shape plate internal fixation. The incidences of delayed carpal tunnel syndrome between the two groups were compared. Among 32 patients treated with open reduction by palm side and T shape plate internal fixation with anterior transverse carpal ligament resection, 3 patients had delayed carpal tunnel syndrome; while in 30 patients treated with open reduction by palm side and T shape plate internal fixation, 10 patients had delayed carpal tunnel syndrome. There was significant statistically difference (P < 0.05%). Simultaneous anterior transverse carpal ligament resection can effectively prevent the delayed carpal tunnel syndrome occurrence for the distal radius fracture with open reduction by palm side.

The spinoglenoid ligament. Anatomy, morphology, and histological findings.

PubMed

Plancher, Kevin D; Peterson, Robert K; Johnston, Jack C; Luke, Timothy A

2005-02-01

Dysfunction of the distal branch of the suprascapular nerve has been reported in athletes involved in throwing or overhead sports. The consistent presence of a dynamic anatomic structure, the spinoglenoid ligament, overlying the nerve in the spinoglenoid notch may be a contributing factor to the dysfunction of this nerve. The purpose of this study was to report the anatomy, morphology, and histological characteristics of the spinoglenoid ligament. The spinoglenoid ligaments of fifty-eight fresh-frozen cadaver shoulders were dissected to evaluate their anatomic dimensions, histological characteristics, and relationship to the suprascapular nerve, the posterior part of the capsule, and the glenoid rim. The spinoglenoid ligament was harvested, with its insertions on the scapular spine and on the capsule and glenoid left intact, for the histological analysis. Dissection revealed that a spinoglenoid ligament was present in all specimens. The ligament was found to form an irregular quadrangular shape. On gross examination, the deep fibers of the ligament extended from the lateral aspect of the scapular spine to the posterior part of the glenoid and the superficial fibers blended with the posterior aspect of the shoulder capsule. Histological sections demonstrated Sharpey fibers inserting into bone at the scapular spine and blending with the posterior aspect of the shoulder capsule to insert into the posterior surface of the glenoid, findings that confirmed the ligamentous nature of this structure. This study revealed the presence of the spinoglenoid ligament in all of the shoulders that were examined, with some variation in the size of the ligament.

A real-time computational model for estimating kinematics of ankle ligaments.

PubMed

Zhang, Mingming; Davies, T Claire; Zhang, Yanxin; Xie, Sheng Quan

2016-01-01

An accurate assessment of ankle ligament kinematics is crucial in understanding the injury mechanisms and can help to improve the treatment of an injured ankle, especially when used in conjunction with robot-assisted therapy. A number of computational models have been developed and validated for assessing the kinematics of ankle ligaments. However, few of them can do real-time assessment to allow for an input into robotic rehabilitation programs. An ankle computational model was proposed and validated to quantify the kinematics of ankle ligaments as the foot moves in real-time. This model consists of three bone segments with three rotational degrees of freedom (DOFs) and 12 ankle ligaments. This model uses inputs for three position variables that can be measured from sensors in many ankle robotic devices that detect postures within the foot-ankle environment and outputs the kinematics of ankle ligaments. Validation of this model in terms of ligament length and strain was conducted by comparing it with published data on cadaver anatomy and magnetic resonance imaging. The model based on ligament lengths and strains is in concurrence with those from the published studies but is sensitive to ligament attachment positions. This ankle computational model has the potential to be used in robot-assisted therapy for real-time assessment of ligament kinematics. The results provide information regarding the quantification of kinematics associated with ankle ligaments related to the disability level and can be used for optimizing the robotic training trajectory.

Treatment of Medial Malleolus or Pure Deltoid Ligament Injury in Patients with Supination-External Rotation Type IV Ankle Fractures.

PubMed

Wang, Xu; Zhang, Chao; Yin, Jian-Wen; Wang, Chen; Huang, Jia-Zhang; Ma, Xin; Wang, Cheng-Wei; Wang, Xue

2017-02-01

To investigate the effect of internal fixation on postoperative ankle function in patients with supination-external rotation type IV ankle fractures, including medial malleolus fractures and deltoid ligament injury. Between January 2012 and June 2014, patients with medial structure injuries were enrolled in this study and assigned to the medial malleolus fracture group or the deltoid ligament group. The surgical procedures for the two groups were documented. The follow-up endpoint was the time point when the steel plate or screw was removed from the lateral ankle. The Olerud-Molander ankle scoring system was used to assess ankle function. A total of 84 patients with supination-external rotation type IV ankle fractures had complete medical records and were included in this study. The average age of the patients was 44.16 years (range, 15-75). The patient sample included 39 males and 45 females. Overall, 49 patients (19 males and 30 females) suffered a medial malleolus fracture. The average age of these patients was 40.20 years (range, 15-75). Patients with a posterior malleolar fracture fragment >25% of the articular surface accounted for 81.6% (40 patients) of these patients. Overall, 35 patients (20 males and 15 females) experienced a deltoid ligament injury. The average age of these patients was 44.21 years (range, 17-73). Patients with a posterior malleolar fracture fragment >25% of the articular surface accounted for 11.5% (four patients) of these patients. Open reduction was performed in patients with medial malleolus fractures, and two 4.0-mm cannulated screws were used to fixate the posterior malleolus and the medial malleolus. The suture-anchor technique was used to repair the ligaments in patients with deltoid ligament injuries. The follow-up endpoint was the time point when the steel plate and screws were removed from the lateral ankle in patients. The average follow-up period was 13.4 months (range, 11-17). The Olerud-Molander ankle scoring system was used to assess postoperative ankle function. The average score for the patients in the medial malleolus fracture group was 90.3 points (range, 85-95). The average score for the patients in the deltoid ligament injury group was 87.7 points (range, 80-95). No significant differences were found in the scores between the two groups. Medial malleolus fracture and deltoid ligament injury are two different presentations of supination-external rotation type IV ankle fractures. Anatomic reduction of the articular surface concurrent with restoration of ankle stability can achieve favorable results for these two injuries. © 2017 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

Bioreactor design for tendon/ligament engineering.

PubMed

Wang, Tao; Gardiner, Bruce S; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B; Wang, Allan; Xu, Jiake; Smith, David W; Lloyd, David G; Zheng, Ming H

2013-04-01

Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a suitable culture environment, which mimics the dynamics of the in vivo environment for tendon/ligament maturation. For clinical settings, bioreactors also have the advantages of less-contamination risk, high reproducibility of cell propagation by minimizing manual operation, and a consistent end product. In this review, we identify the key components, design preferences, and criteria that are required for the development of an ideal bioreactor for engineering tendons and ligaments.

Bioreactor Design for Tendon/Ligament Engineering

PubMed Central

Wang, Tao; Gardiner, Bruce S.; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B.; Wang, Allan; Xu, Jiake

2013-01-01

Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a suitable culture environment, which mimics the dynamics of the in vivo environment for tendon/ligament maturation. For clinical settings, bioreactors also have the advantages of less-contamination risk, high reproducibility of cell propagation by minimizing manual operation, and a consistent end product. In this review, we identify the key components, design preferences, and criteria that are required for the development of an ideal bioreactor for engineering tendons and ligaments. PMID:23072472

A comparison of human and porcine acellularized dermis: interactions with human fibroblasts in vitro.

PubMed

Armour, Alexis D; Fish, Joel S; Woodhouse, Kimberly A; Semple, John L

2006-03-01

Dermal substitutes derived from xenograft materials require elaborate processing at a considerable cost. Acellularized porcine dermis is a readily available material associated with minimal immunogenicity. The objective of this study was to evaluate acellularized pig dermis as a scaffold for human fibroblasts. In vitro methods were used to evaluate fibroblast adherence, proliferation, and migration on pig acellularized dermal matrix. Acellular human dermis was used as a control. Pig acellularized dermal matrix was found to be inferior to human acellularized dermal matrix as a scaffold for human fibroblasts. Significantly more samples of human acellularized dermal matrix (83 percent, n = 24; p < 0.05) demonstrated fibroblast infiltration below the cell-seeded surface than pig acellularized dermal matrix (31 percent, n = 49). Significantly more (p < 0.05) fibroblasts infiltrated below the surface of human acellularized dermal matrix (mean, 1072 +/- 80 cells per section; n = 16 samples) than pig acellularized dermal matrix (mean, 301 +/- 48 cells per section; n = 16 samples). Fibroblasts migrated significantly less (p < 0.05) distance from the cell-seeded pig acellularized dermal matrix surface than in the human acellularized dermal matrix (78.8 percent versus 38.3 percent cells within 150 mum from the surface, respectively; n = 5). Fibroblasts proliferated more rapidly (p < 0.05) on pig acellularized dermal matrix (n = 9) than on the human acellularized dermal matrix (7.4-fold increase in cell number versus 1.8-fold increase, respectively; n = 9 for human acellularized dermal matrix). There was no difference between the two materials with respect to fibroblast adherence (8120 versus 7436 average adherent cells per section, for pig and human acellularized dermal matrix, respectively; n = 20 in each group; p > 0.05). Preliminary findings suggest that substantial differences may exist between human fibroblast behavior in cell-matrix interactions of porcine and human acellularized dermis.

Lateral clavicle fracture with coracoclavicular ligament injury: a biomechanical study of 4 different repair techniques.

PubMed

Alaee, Farhang; Apostolakos, John; Singh, Hardeep; Holwein, Christian; Diermeier, Theresa; Cote, Mark P; Beitzel, Knut; Imhoff, Andreas B; Mazzocca, Augustus D; Voss, Andreas

2017-07-01

To investigate the biomechanical performance of four different methods used for coracoclavicular (CC) ligament reconstruction in a lateral clavicle fracture repair. Native displacement, translation, and rotation at the acromioclavicular joint of 24 fresh-frozen cadaveric shoulders were tested. A reproducible fracture in the lateral third of the clavicle was created by dissecting both CC ligaments. Each specimen was then repaired with plate fixation of the fracture and the following CC repair technique: (1) Cortical button. (2) Suture anchor and plate button. (3) Suture anchor no plate button, and (4) Suture around coracoid. All reconstructed specimens were then re-tested for displacement, translation, and load to failure, and compared to their native results. Groups 1 and 3 were investigated for rotational load. There was no difference in load to failure between the repaired groups (p: ns). Group 1 showed less superior and anterior translations (p < 0.05). Group 2 showed significantly less superior translation (p = 0.003), but no significance with anterior and posterior translations to the native joint. Group 3 showed less superior and posterior translations (p = 0.005 and p = 0.039). Anterior and posterior translations were increased in group 4 (p < 0.05). The biomechanical analyses did not show any significance in load to failure or displacement after cyclic loading among the study groups. All repairs were effective in preventing superior translation. Groups 1 and 2 demonstrated increased horizontal stability compared to the native state. All 4 methods are clinically viable options for CC ligament repair.

Lipoma of round ligament on the intraperitoneal portion (abdominal site): a case report.

PubMed

Ozdemır, Ozhan; Sarı, Mustafa Erkan; Sakar, Vefa Selimova; Nebıoglu, Mehriban; Atalay, Cemal Resat

2017-09-01

Primary tumors of round ligament are rare, and when found are typically leiomyomas. Endometrioma, and mesothelial cysts are the benign lesions recognized as involving the round ligament. We report a case of lipoma of the round ligament in a 48-year-old premenopausal woman. Round ligament lipoma on the intraperitoneal portion (abdominal site) is very rare and it should be kept in the differential diagnosis of ovarian and abdominal masses.

[Acute injuries of lateral ankle joint ligaments].

PubMed

Lacko, M; Sidor, Z; Stolfa, S; Cellár, R; Vasko, G

2010-08-01

Acute injuries of the lateral ankle ligaments are one of the most common form of injury involving the musculoskeletal apparatus. Treatment usually range from cast immobilisation or acute surgical repair to functional rehabilitation. The aim of our study was to evaluate the incidence of different grades of acute injuries of lateral ligaments of the ankle joint in our patients group and to compare the results of non surgical versus surgical treatment of third grade injuries. 3148 patients were treated for acute lateral ankle sprain in a period of 5 years at our department. Each patient had stress X-ray of the ankle for evaluation of instability at the first visit. From the 234 patients with third grade injury, 39 were enrolled in our study with non surgical treatment and 18 with surgical treatment. Each group was divided regarding to the age in two subgroups. Functional outcome was evaluated 12 and 24 months after injury with AOFAS clinical rating scale and Sports Ankle Rating System--Single Assessment Numeric Evaluation. Statistical analysis was done with Pearson's Chi quadrate test with P < 0.05. First grade injury was present in 62%, second grade in 31% and only 7% of the patients had third grade injury of the lateral ankle ligaments. Further only third grade injuries were studied. Statistically significant better results were seen in patients under the age of 25, in the patient group with surgical treatment compared to patients over 25 years of age. Also statistically significant better results were seen in patient with surgical treatment to non surgical treatment in each age group. No significant difference was observed in the non surgical treatment group regarding to age. Although the injuries of the ankle ligaments belong to the most common injuries of the musculoskeletal system, there is no consensus in the treatment of such disorders. Our experiences and the results of our study show, that surgical treatment in indicated cases provides better results in residual pain and instability of the ankle joint after acute injury of the lateral ankle ligaments.;

Comparison of reaction forces on the anterior cruciate and anterolateral ligaments during internal rotation and anterior drawer forces at different flexion angles of the knee joint.

PubMed

Uğur, Levent

2017-12-01

Having a complicated anatomy, the knee joint has been further detailed and a new formation defined, the anterolateral ligament (ALL), in recent studies. While the importance of this ligament, which previously was associated with Segond fractures, was explained via clinical, radiologic and biomechanical studies, and basically, is thought to be a fixator structures for the tibia against internal rotation stress. Although in recent studies efficient surgical treatment was applied to patients who underwent anterior cruciate ligament (ACL) operation, some patients having a positive pivot test highlights the clinical importance of the ALL. The aim of this study is to evaluate reaction forces of different flexion angles on the tibia during internal rotation and anterior drawer tests on both the ALL and ACL, and to examine theimportance of this ligament in knee biomechanics by a finite element analysis method. In this study, normal anatomy knee joint was modelled using Computed Tomography images from lower extremity length in DICOM format. 0°, 15°,30°,45°,60°,75° and 90° angles of flexion were applied, respectively, to these models and reaction force vectors formed on both ligaments were examined separately and as total vector and size by applying internal rotation and anterior drawer forces on each model. Non-linear analysis was conducted using ANSYS (version 17) with the same limit conditions applied to all models. After all models were examined, in general when comparing reaction forces, those on the ACL were found to be higher. However, when vectoral directions were examined, forces on ALL increased with increased flexion ratio and internal rotation momentum. Beyond 30° flexion, the tensile force on the ALL is increased and compressive overload on the ACL occurs. The ALL plays an important role in stability, especially against internal rotation forces, and an increased knee joint flexion ratio increases the stability contribution ratio. In particular, at 30° and higher angles, ACL reflects an antagonist effect and contributes to knee joint stability for rotational and mediolateral transposition. Copyright © 2017 John Wiley & Sons, Ltd.

Modification and Utilization of Nanoporous Gold for Loading and Release of Drugs

NASA Astrophysics Data System (ADS)

Al-badri, Ibtisam

Nanoporous gold (np-Au) is a sponge-like structure of gold, which can be created by removing the less noble element from the precursor alloy, most typically silver or copper, using different chemical or electrochemical methods. It consists of interconnected ligaments and gaps between the ligaments, whose width can range from a few nanometers to a few hundreds of nanometers, creating a high surface area-to-volume ratio. Due to its many important properties (e.g., conductivity, high surface area-to-volume ratio, plasmonic response, biocompatibility, chemically inertness, and physically robustness), np-Au is suitable for different types of applications, including as a transducer for biosensors, in catalysis, for biomolecule separation, as a substrate for enzyme immobilization, and in drug delivery. The widths of the ligaments and gaps of np-Au can be easily tuned by varying conditions during the pre- or post-production process, for example, time kept in an acid bath and post-annealing (e.g. thermal, chemical, and electrochemical), depending on the requirement of the study. Thermal annealing is a commonly used process for tuning the ligaments and pore size of np-Au. However, the effects of thermal annealing on modification of ligaments and gaps sizes are not completely understood and more research needs to be done. Herein, we have explored the effect of annealing time and thickness of the np-Au sample on modification of ligaments and gaps. Furthermore, we used the electroless plating method to cover the pores or gaps partially on the surface without modifying the interior of np-Au. As-prepared np-Au was then studied as a platform for molecular loading and releasing kinetics for the possible use in drug delivery. We have found that simply applying the electroless deposition for 1 to 5 min can drastically decrease the rate of release of the molecules, and flow cell-based loading is the preferred way to load the molecules inside np-Au compared to the static method. The structure of the np-Au monoliths before and after the modification was characterized using Energy-Dispersive X-ray Spectroscopy (EDS) and scanning electron microscopy (SEM), whereas the molecular loading and releasing studies were performed using UV-Vis spectrophotometer.

An accuracy evaluation of clinical, arthrometric, and stress-sonographic acute ankle instability examinations.

PubMed

Wiebking, Ulrich; Pacha, Tarek Omar; Jagodzinski, Michael

2015-03-01

Ankle sprain injuries, often due to lateral ligamentous injury, are the most common sports traumatology conditions. Correct diagnoses require an understanding of the assessment tools with a high degree of diagnostic accuracy. Obviously, there are still no clear consensuses or standard methods to differentiate between a ligament tear and an ankle sprain. In addition to clinical assessments, stress sonography, arthrometer and other methods are often performed simultaneously. These methods are often costly, however, and their accuracy is controversial. The aim of this study was to investigate three different measurement tools that can be used after a lateral ligament lesion of the ankle with injury of the anterior talofibular ligament to determine their diagnostic accuracy. Thirty patients were recruited for this study. The mean patient age was 35±14 years. There were 15 patients with a ligamentous rupture and 15 patients with an ankle sprain. We quantified two devices and one clinical assessment by which we calculated the sensitivity and specifity: Stress sonography according to Hoffmann, an arthrometer to investigate the 100N talar drawer and maximum manual testing and the clinical assessment of the anterior drawer test. A high resolution sonography was used as the gold standard. The ultrasound-assisted gadgetry according to Hoffmann, with a 3mm cut-off value, displayed a sensitivity of 0.27 and a specificity of 0.87. Using a 3.95mm cut-off value, the arthrometer displayed a sensitivity of 0.8 and a specificity of 0.4. The clinical investigation sensitivities and specificities were 0.93 and 0.67, respectively. Different assessment methods for ankle rupture diagnoses are suggested in the literature; however, these methods lack reliable data to set investigation standards. Clinical examination under adequate analgesia seems to remains the most reliable tool to investigate ligamentous ankle lesions. Further clinical studies with higher case numbers are necessary, however, to evaluate these findings and to measure the reliability. Copyright © 2014 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Wrist kinetics after luno-triquetral dissociation: the changes in moment arms of the flexor carpi ulnaris tendon.

PubMed

Tang, Jin Bo; Xie, Ren Gou; Yu, Xiao Wei; Chen, Feng

2002-11-01

Wrist biomechanics after luno-triquetral (LT) dissociation is important for understanding the clinical sequelae of the disease and for determining its treatment options. The LT interosseous ligament plays an important role in stabilizing the joint and damage to the ligament would be expected to significantly increase moment arms of tendon of the flexor carpi ulnaris (FCU), the principal ulnar wrist flexor. We investigated the changes in moment arms of FCU tendon after various amounts of sectioning of the ligaments proven to be associated with LT dissociation. In six fresh frozen cadaveric upper extremities, excursions of the FCU tendon were recorded simultaneously with wrist joint angulation during wrist flexion-extension and radioulnar deviation. Tendon excursions were measured in intact wrists, in wrists with sectioning of the dorsal portion of the LT interosseous ligament, in wrists with sectioning of the entire LT interosseous ligament, and finally in wrists with further sectioning of the dorsal radiotriquetral and intercarpal ligaments. Moment arms of the tendon were calculated from tendon excursions and joint motion angulations and expressed as percentage changes from those in the intact wrist. During wrist flexion-extension, moment arms of the FCU tendon after sectioning of the entire LT interosseous ligament and after sectioning of the two capsular ligaments were 112 +/- 7% and 114 +/- 8%, respectively; these values were significantly greater than those in the intact wrist. During radioulnar deviation, the moment arms were 114 +/- 11% after sectioning of the dorsal portion of the LT interosseous ligament, 134 +/- 15% after sectioning of the entire ligament, and 153 +/- 18% after sectioning of the capsular ligaments, again being significantly greater than the normal wrist. Increase in moment arms of the FCU tendon after loss of integrity of the LT interosseous ligament and dorsal capsular ligaments may contribute to clinical sequelae of LT dissociation and difficulty in treating this disorder.

ACL/MCL transection affects knee ligament insertion distance of healing and intact ligaments during gait in the Ovine model.

PubMed

Tapper, Janet E; Funakoshi, Yusei; Hariu, Mitsuhiro; Marchuk, Linda; Thornton, Gail M; Ronsky, Janet L; Zernicke, Ron; Shrive, Nigel G; Frank, Cyril B

2009-08-25

The objective of this study was to assess the impact of combined transection of the anterior cruciate and medial collateral ligaments on the intact and healing ligaments in the ovine stifle joint. In vivo 3D stifle joint kinematics were measured in eight sheep during treadmill walking (accuracy: 0.4+/-0.4mm, 0.4+/-0.4 degrees ). Kinematics were measured with the joint intact and at 2, 4, 8, 12, 16 and 20 weeks after either surgical ligament transection (n=5) or sham surgery without transection (n=3). After sacrifice at 20 weeks, the 3D subject-specific bone and ligament geometry were digitized, and the 3D distances between insertions (DBI) of ligaments during the dynamic in vivo motion were calculated. Anterior cruciate ligament/medial collateral ligament (ACL/MCL) transection resulted in changes in the DBI of not only the transected ACL, but also the intact lateral collateral ligament (LCL) and posterior cruciate ligament (PCL), while the DBI of the transected MCL was not significantly changed. Increases in the maximal ACL DBI (2 week: +4.2mm, 20 week: +5.7mm) caused increases in the range of ACL DBI (2 week: 3.6mm, 20 week: +3.8mm) and the ACL apparent strain (2 week: +18.9%, 20 week: +24.0%). Decreases in the minimal PCL DBI (2 week: -3.2mm, 20 week: -4.3mm) resulted in increases in the range of PCL DBI (2 week: +2.7mm, 20 week: +3.2mm). Decreases in the maximal LCL DBI (2 week: -1.0mm, 20 week: -2.0mm) caused decreased LCL apparent strain (2 week: -3.4%, 20 week: -6.9%). Changes in the mechanical environment of these ligaments may play a significant role in the biological changes observed in these ligaments.

Dynamic high-resolution ultrasound of intrinsic and extrinsic ligaments of the wrist: How to make it simple.

PubMed

Gitto, Salvatore; Messina, Carmelo; Mauri, Giovanni; Aliprandi, Alberto; Sardanelli, Francesco; Sconfienza, Luca Maria

2017-02-01

Wrist ligaments are crucial structures for the maintenance of carpal stability. They are classified into extrinsic ligaments, connecting the carpus with the forearm bones or distal radioulnar ligaments, and intrinsic ligaments, entirely situated within the carpus. Lesions of intrinsic and extrinsic ligaments of the wrist have been demonstrated to occur largely, mostly in patients with history of trauma and carpal instability, or rheumatoid arthritis. Ultrasound allows for rapid, cost-effective, non-invasive and dynamic evaluation of the wrist, and may represent a valuable diagnostic tool. Although promising results have been published, ultrasound of wrist ligaments is not performed in routine clinical practice, maybe due to its technical feasibility regarded as quite complex. This review article aims to enlighten readers about the normal sonographic appearance of intrinsic and extrinsic carpal ligaments, and describe a systematic approach for their sonographic assessment with detailed anatomic landmarks, dynamic manoeuvres and scanning technique. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Prospectively identified deficits in sagittal plane hip-ankle coordination in female athletes who sustain a second anterior cruciate ligament injury after anterior cruciate ligament reconstruction and return to sport.

PubMed

Paterno, Mark V; Kiefer, Adam W; Bonnette, Scott; Riley, Michael A; Schmitt, Laura C; Ford, Kevin R; Myer, Gregory D; Shockley, Kevin; Hewett, Timothy E

2015-12-01

Athletes who return to sport after anterior cruciate ligament reconstruction are at increased risk of future ACL injury. Altered coordination of lower extremity motion may increase this risk. The purpose of this study was to prospectively determine if altered lower extremity coordination patterns exist in athletes who go on to sustain a 2nd anterior cruciate ligament injury. Sixty-one female athletes who were cleared to return to sport after anterior cruciate ligament reconstruction were included. Hip-ankle coordination was assessed prior to return to sport with a dynamic postural coordination task. Within 12 months, 14 patients sustained a 2nd ACL injury. Fourteen matched subjects were selected for comparative analysis. Cross-recurrence quantification analysis characterized hip-ankle coordination patterns. A group × target speed (slow vs. fast) × leg (involved vs. uninvolved) analysis of variance was used to identify differences. A main effect of group (P = 0.02) indicated that the single injury group exhibited more stable hip-ankle coordination [166.2 (18.9)] compared to the 2nd injury group [108.4 (10.1)]. A leg × group interaction was also observed (P = .04). The affected leg of the single injury group exhibited more stable coordination [M = 187.1 (23.3)] compared to the affected leg of the 2nd injury group [M = 110.13 (9.8)], P = 0.03. Hip-ankle coordination was altered in female athletes who sustained a 2nd anterior cruciate ligament injury after return to sport. Failure to coordinate lower extremity movement in the absence of normal knee proprioception may place the knee at risk. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prospectively Identified Deficits in Sagittal Plane Hip-Ankle Coordination in Female Athletes who Sustain a Second Anterior Cruciate Ligament Injury after Anterior Cruciate Ligament Reconstruction and Return to Sport

PubMed Central

Paterno, Mark V.; Kiefer, Adam W.; Bonnette, Scott; Riley, Michael A.; Schmitt, Laura C.; Ford, Kevin R.; Myer, Gregory D.; Shockley, Kevin; Hewett, Timothy E.

2015-01-01

Background Athletes who return to sport after anterior cruciate ligament reconstruction are at increased risk of future ACL injury. Altered coordination of lower extremity motion may increase this risk. The purpose of this study was to prospectively determine if altered lower extremity coordination patterns exist in athletes who go on to sustain a 2nd anterior cruciate ligament injury. Methods Sixty-one female athletes who were medically cleared to return to sport after anterior cruciate ligament reconstruction were included. Hip-ankle coordination was assessed prior to return to sport with a dynamic postural coordination task. Within 12 months, 14 patients sustained a 2nd ACL injury. Fourteen matched subjects were selected for comparative analysis. Cross-recurrence quantification analysis characterized hip-ankle coordination patterns. A group × target speed (slow vs. fast) × leg (involved vs. uninvolved) analysis of variance was used to identify coordination differences. Findings A main effect of group (p = 0.02) indicated that the single injury group exhibited more stable hip-ankle coordination [166.2 (18.9)] compared to the 2nd injury group [108.4 (10.1)]. A leg × group interaction was also observed (p = .04). The affected leg of the single injury group exhibited more stable coordination [M = 187.1 (23.3)] compared to the affected leg of the 2nd injury group [M = 110.13 (9.8)], p = 0.03. Interpretation Hip-ankle coordination was altered in female athletes who sustained a 2nd anterior cruciate ligament injury after return to sport. Failure to coordinate lower extremity movement in the absence of normal knee proprioception may place the knee at high-risk. PMID:26416200

The association between lower extremity energy absorption and biomechanical factors related to anterior cruciate ligament injury.

PubMed

Norcross, Marc F; Blackburn, J Troy; Goerger, Benjamin M; Padua, Darin A

2010-12-01

Greater total energy absorption by the lower extremity musculature during landing may reduce stresses placed on capsuloligamentous tissues with differences in joint contributions to energy absorption potentially affecting anterior cruciate ligament injury risk. However, the relationships between energy absorption and prospectively identified biomechanical factors associated with non-contact anterior cruciate ligament injury have yet to be demonstrated. Sagittal plane total, hip, knee and ankle energy absorption, and peak vertical ground reaction force, anterior tibial shear force, knee flexion and knee valgus angles, and internal hip extension and knee varus moments were measured in 27 individuals (14 females, 13 males) performing double leg jump landings. Correlation coefficients assessed the relationships between energy absorption during three time intervals (initial impact phase, terminal phase, and total landing) and biomechanical factors related to anterior cruciate ligament injury. More favorable values of biomechanical factors related to non-contact anterior cruciate ligament injury were associated with: 1) Lesser total (R(2)=0.178-0.558), hip (R(2)=0.229-0.651) and ankle (R(2)=0.280), but greater knee (R(2)=0.147) energy absorption during the initial impact phase; 2) Greater total (R(2)=0.170-0.845), hip (R(2)=0.599), knee (R(2)=0.236-0.834), and ankle (R(2)=0.276) energy absorption during the terminal phase of landing; and 3) Greater knee (R(2)=0.158-0.709), but lesser hip (R(2)=0.309) and ankle (R(2)=0.210-0.319) energy absorption during the total landing period. These results suggest that biomechanical factors related to anterior cruciate ligament injury are influenced by both the magnitude and timing of lower extremity energy absorption during landing. Copyright © 2010 Elsevier Ltd. All rights reserved.

Local delivery of controlled-release simvastatin to improve the biocompatibility of polyethylene terephthalate artificial ligaments for reconstruction of the anterior cruciate ligament.

PubMed

Zhang, Peng; Han, Fei; Li, Yunxia; Chen, Jiwu; Chen, Tianwu; Zhi, Yunlong; Jiang, Jia; Lin, Chao; Chen, Shiyi; Zhao, Peng

2016-01-01

The Ligament Advanced Reinforcement System has recently been widely used as the primary graft of choice in anterior cruciate ligament (ACL) reconstruction. But the biological graft-bone healing still remains a problem. Previous studies have shown that simvastatin (SIM) stimulates bone formation. The objective of this study was to investigate whether surface coating with collagen containing low-dose SIM microsphere could enhance the surface biocompatibility of polyethylene terephthalate (PET) artificial ligaments to accelerate graft-to-bone healing. The in vitro studies demonstrated that bone marrow stromal cells on the collagen-coated PET scaffolds (COL/PET) and simvastatin/collagen-coated PET scaffolds (SIM/COL/PET) proliferated vigorously. Compared with the PET group and the COL/PET group, SIM could induce bone marrow stromal cells' osteoblastic differentiation, high alkaline phosphatase activity, more mineralization deposition, and more expression of osteoblast-related genes, such as osteocalcin, runt-related transcription factor 2, bone morphogenetic protein-2, and vascular endothelial growth factor, in the SIM/COL/PET group. In vivo, rabbits received ACL reconstruction with different scaffolds. Histological analysis demonstrated that graft-bone healing was significantly greater with angiogenesis and osteogenesis in the SIM/COL/PET group than the other groups. In addition, biomechanical testing at the eighth week demonstrated a significant increase in the ultimate failure load and stiffness in the SIM/COL/PET group. The low dose of SIM-sustained release from SIM/COL/PET promoted the graft-bone healing via its effect on both angiogenesis and osteogenesis. This study suggested that collagen containing low-dose SIM microsphere coating on the surface of PET artificial ligaments could be potentially applied for ACL reconstruction.

Effect of botulinum toxin type A on transforming growth factor beta1 in fibroblasts derived from hypertrophic scar: a preliminary report.

PubMed

Xiao, Zhibo; Zhang, Fengmin; Lin, Weibin; Zhang, Miaobo; Liu, Ying

2010-08-01

Hypertrophic scar is a common dermal disease. Numerous treatments are currently available but they do not always yield excellent therapeutic results. Hence, alternatives are needed. Recent basic and clinical research has shown that botulinum toxin type A (BTXA) has antihypertrophic scar properties but the molecular mechanism for this action is unknown. The aim of this study was to explore the effect of BTXA on transforming growth factor beta1 (TGF-beta1) in fibroblasts derived from hypertrophic scar and further elucidate its actual mechanism. Fibroblasts were isolated from tissue specimens of hypertrophic scar. Fibroblasts were treated with BTXA and the difference in proliferation between treated and nontreated cells was analyzed through the MTT method from the first to the fifth day after treatment. Proteins of TGF-beta1 were checked using ELISA in fibroblasts with BTXA and without BTXA from the first to the fifth day. The growth of the fibroblast treated with BTXA was obviously slower than that of the fibroblast without BTXA treatment (p < 0.01), which showed that BTXA effectively inhibited the growth of fibroblasts. Proteins of TGF-beta1 between fibroblasts with BTXA and fibroblasts without BTXA are statistically significant (p < 0.01). These results suggest that BTXA effectively inhibited the growth of fibroblasts derived from hypertrophic scar and in turn caused a decrease in TGF-beta1 protein, indicating that BTXA-based therapies for hypertrophic scar are promising and worth investigating further.

The Orientation and Variation of the Acromioclavicular Ligament: An Anatomic Study.

PubMed

Nakazawa, Masataka; Nimura, Akimoto; Mochizuki, Tomoyuki; Koizumi, Masahiro; Sato, Tatsuo; Akita, Keiichi

2016-10-01

Several biomechanical studies have shown that the acromioclavicular (AC) ligament prevents posterior translation of the clavicle in the horizontal plane. In anatomy textbooks, however, the AC ligament is illustrated as running straight across the AC joint surface. The AC ligament does not run straight across the joint surface, and the configuration of the AC ligament may vary. Descriptive laboratory study. We used 16 pairs of shoulder girdles in this study. After identifying the AC ligament, we macroscopically investigated the orientation and attachment of the ligament and measured the angle between the ligament and the line perpendicular to the AC joint surface by using a digital goniometer. In addition, the AC joint inclination angle was measured, and the Spearman rank correlation coefficient between the joint inclination and the ligament angle was calculated. Finally, we sought to classify the AC ligament based on its configuration. Of the 16 pairs of specimens, 3 pairs of shoulders were histologically examined. The AC ligament was divided into 2 parts: a bundle at the superoposterior (SP) part and a bundle at the anteroinferior (AI) part of the joint. The well-developed SP bundle was consistent and ran obliquely at an average ± SD 30° ± 6° in relation to the AC joint surface, from the anterior part of the acromion to the posterior part of the distal clavicle. The joint inclination was 70° ± 12°, and a negative moderate correlation was found between the joint inclination and the ligament angle (P = .02, r = -0.46). In comparison, the AI bundle was thin and narrow, and it could be categorized into 3 types according to its various configurations. The AC ligament could be separated into the SP bundle and the AI bundle. The SP bundle ran posteriorly toward the distal clavicle from the acromion at an average angle of 30° to the joint surface. Anatomic reconstruction, based on the current findings in combination with findings regarding the coracoclavicular ligament, could facilitate improved outcome in the treatment of AC joint disruption. © 2016 The Author(s).

Rupture of the meniscofibular ligament

PubMed Central

2010-01-01

The meniscofibular ligament is an anatomically defined ligament of the knee in humans. However, there are no data regarding the prognosis following injury to this ligament. Our case was a 42-year-old man who presented at our clinic with pain of the lateral side of his left knee. MRI of his left knee revealed the rupture of the meniscofibular ligament. The mechanism of injury was consistent with anatomical and mechanical studies of the meniscofibular ligament. The patient was treated conservatively for 1 year, but his pain did not resolve completely. A case series of patients with the same injury is required to establish an effective treatment for this rare injury. PMID:20478075

Hematoma of the falciform ligament: a rare cause of acute abdomen.

PubMed

Sari, Serkan; Ersöz, Feyzullah; Güneş, Mehmet Emin; Paşaoğlu, Esra; Arikan, Soykan

2011-01-01

Hematoma or abscess of the liver ligaments is extremely rare, and hematoma of the falciform ligament has been sporadically reported. We report the case of a 70-year-old female who presented with a three-day history of right upper quadrant abdominal pain, fever and nausea. With a preoperative diagnosis of probable perforated acalculous cholecystitis, the patient underwent emergency surgery. Hematoma of the falciform ligament was found. Wide excision of the falciform ligament including the hematoma with abscess was performed. Although pathology of the falciform ligament is rare, it should be included in the differential diagnosis of acute abdomen, especially in the case of antiaggregant drug usage.

Ultrasonographic assessment of the proximal digital annular ligament in the equine forelimb.

PubMed

Dik, K J; Boroffka, S; Stolk, P

1994-01-01

Ultrasonography was used with 6 normal cadaver forelimbs of Dutch Warmblood horses to delineate the ultrasonographic anatomy of the palmar pastern region, with emphasis on the proximal digital annular ligament. Using a 5.5 MHz sector scanner, the thin proximal digital annular ligament was not visible on offset sonograms. Only if the digital sheath in the normal limb was distended was the distal border of this ligament outlined. In all normal limbs the palmarodistal thickness of the combined skin-proximal digital annular ligament layer in the mid-pastern region was 2 mm. The flexor tendons and distal sesamoidean ligaments were easily identified as hyperechoic structures. Distension of the digital sheath in the normal limbs clearly outlined the anechoic digital sheath pouches. In 4 lame horses ultrasonography aided the diagnosis of functional proximal digital annular ligament constriction. In all 4 diseased forelimbs ultrasonography demonstrated thickening of the skin-proximal digital annular ligament layer and distension of the digital sheath. In one of these limbs the distended digital sheath was also thickened. The flexor tendons and distal sesamoidean ligaments were normal. There was no radiographic evidence of additional bone or joint lesions.

What's new in the functional anatomy of pelvic organ prolapse?

PubMed

DeLancey, John O L

2016-10-01

Provide an evidence-based review of pelvic floor functional anatomy related to pelvic organ prolapse. Pelvic organ support depends on interactions between the levator ani muscle and pelvic connective tissues. Muscle failure exposes the vaginal wall to a pressure differential producing abnormal tension on the attachments of the pelvic organs to the pelvic sidewall. Birth-induced injury to the pubococcygeal portion of the levator ani muscle is seen in 55% of women with prolapse and 16% of women with normal support. Failure of the lateral connective tissue attachments between the uterus and vagina to the pelvic wall (cardinal, uterosacral, and paravaginal) are strongly related with prolapse (effect sizes ∼2.5) and are also highly correlated with one another (r ∼ 0.85). Small differences exist with prolapse in factors involving the vaginal wall length and width (effect sizes ∼1). The primary difference in ligament properties between women with and without prolapse is found in ligament length. Only minor differences in ligament stiffness are seen. Pelvic organ prolapse occurs because of injury to the levator ani muscles and failure of the lateral connections between the pelvic organs to the pelvic sidewall. Abnormalities of the vaginal wall fascial tissues may play a minor role.

Inefficient reprogramming of fibroblasts into cardiomyocytes using Gata4, Mef2c, Tbx5

PubMed Central

Chen, J.X.; Krane, M.; Deutsch, M. A.; Wang, L.; Rav-Acha, M.; Gregoire, S.; Engels, M. C.; Rajarajan, K.; Karra, R.; Abel, E. D.; Wu, J. C.; Milan, D.; Wu, S. M.

2012-01-01

Rationale Direct reprogramming of fibroblasts into cardiomyocytes is a novel strategy for cardiac regeneration. However, the key determinants involved in this process are unknown. Objective To assess the efficiency of direct fibroblast reprogramming via viral overexpression of GATA4, Mef2c, and Tbx5 (GMT). Methods and Results We induced GMT overexpression in murine tail tip fibroblasts (TTFs) and cardiac fibroblasts (CFs) from multiple lines of transgenic mice carrying different cardiomyocyte lineage reporters. We found that the induction of GMT overexpression in TTFs and CFs is inefficient at inducing molecular and electrophysiological phenotypes of mature cardiomyocytes. In addition, transplantation of GMT infected CFs into injured mouse hearts resulted in decreased cell survival with minimal induction of cardiomyocyte genes. Conclusions Significant challenges remain in our ability to convert fibroblasts into cardiomyocyte-like cells and a greater understanding of cardiovascular epigenetics is needed to increase the translational potential of this strategy. PMID:22581928

Surface modification of nano-silica on the ligament advanced reinforcement system for accelerated bone formation: primary human osteoblasts testing in vitro and animal testing in vivo.

PubMed

Li, Mengmeng; Wang, Shiwen; Jiang, Jia; Sun, Jiashu; Li, Yuzhuo; Huang, Deyong; Long, Yun-Ze; Zheng, Wenfu; Chen, Shiyi; Jiang, Xingyu

2015-05-07

The Ligament Advanced Reinforcement System (LARS) has been considered as a promising graft for ligament reconstruction. To improve its biocompatibility and effectiveness on new bone formation, we modified the surface of a polyethylene terephthalate (PET) ligament with nanoscale silica using atom transfer radical polymerization (ATRP) and silica polymerization. The modified ligament is tested by both in vitro and in vivo experiments. Human osteoblast testing in vitro exhibits an ∼21% higher value in cell viability for silica-modified grafts compared with original grafts. Animal testing in vivo shows that there is new formed bone in the case of a nanoscale silica-coated ligament. These results demonstrate that our approach for nanoscale silica surface modification on LARS could be potentially applied for ligament reconstruction.

The anatomy of the coracohumeral ligament and its relation to the subscapularis muscle.

PubMed

Arai, Ryuzo; Nimura, Akimoto; Yamaguchi, Kumiko; Yoshimura, Hideya; Sugaya, Hiroyuki; Saji, Takahiko; Matsuda, Shuichi; Akita, Keiichi

2014-10-01

Only a few reports describe the extension of the coracohumeral ligament to the subscapularis muscle. The purposes of this study were to histo-anatomically examine the structure between the ligament and subscapularis and to discuss the function of the ligament. Nineteen intact embalmed shoulders were used. In 9 shoulders, the expansion of the ligament was anatomically observed, and in 6 of these 9, the muscular tissue of the supraspinatus and subscapularis was removed to carefully examine the attachments to the tendons of these muscles. Five shoulders were frozen and sagittally sectioned into 3-mm-thick slices. After observation, histologic analysis was performed on 3 of these shoulders. In the remaining 5 shoulders, the coracoid process was harvested to investigate the ligament origin. The coracohumeral ligament originated from the horizontal limb and base of the coracoid process and enveloped the cranial part of the subscapularis muscle. The superficial layer of the ligament covered a broad area of the anterior surface of the muscle. Laterally, it protruded between the long head of the biceps tendon and subscapularis and attached to the tendinous floor, which extended from the subscapularis insertion. Histologically, the ligament consisted of irregular and sparse fibers abundant in type III collagen. The coracohumeral ligament envelops the whole subscapularis muscle and insertion and seems to function as a kind of holder for the subscapularis and supraspinatus muscles. The ligament is composed of irregular and sparse fibers and contains relatively rich type III collagen, which would suggest flexibility. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Pelvic belt effects on sacroiliac joint ligaments: a computational approach to understand therapeutic effects of pelvic belts.

PubMed

Sichting, Freddy; Rossol, Jerome; Soisson, Odette; Klima, Stefan; Milani, Thomas; Hammer, Niels

2014-01-01

The sacroiliac joint is a widely described source of low back pain. Therapeutic approaches to relieve pain include the application of pelvic belts. However, the effects of pelvic belts on sacroiliac joint ligaments as potential pain generators are mostly unknown. The aim of our study was to analyze the influence of pelvic belts on ligament load by means of a computer model. Experimental computer study using a finite element method. A computer model of the human pelvis was created, comprising bones, ligaments, and cartilage. Detailed geometries, material properties of ligaments, and in-vivo pressure distribution patterns of a pelvic belt were implemented. The effects of pelvic belts on ligament strain were computed in the double-leg stance. Pelvic belts increase sacroiliac joint motion around the sagittal axis but decrease motion around the transverse axis. With pelvic belt application, most of the strained sacroiliac joint ligaments were relieved, especially the sacrospinous, sacrotuberous, and the interosseous sacroiliac ligaments. Sacroiliac joint motion and ligament strains were minute. These results agree with validation data from other studies. Assigning homogenous and linear material properties and excluding muscle forces are clear simplifications of the complex reality. Pelvic belts alter sacroiliac joint motion and provide partial relief of ligament strain that is subjectively marked, although minimal in absolute terms. These findings confirm theories that besides being mechanical stabilizers, the sacroiliac joint ligaments are likely involved in neuromuscular feedback mechanisms. The results from our computer model help with unraveling the therapeutic mechanisms of pelvic belts.

Mechanical tensile properties of the anterolateral ligament.

PubMed

Zens, Martin; Feucht, Matthias J; Ruhhammer, Johannes; Bernstein, Anke; Mayr, Hermann O; Südkamp, Norbert P; Woias, Peter; Niemeyer, Philipp

2015-12-01

In a noticeable percentage of patients anterolateral rotational instabilities (ALRI) remain after an isolated ACL reconstruction. Those instabilities may occur due to an insufficiently directed damage of anterolateral structures that is often associated with ACL ruptures. Recent publications describe an anatomical structure, termed the anterolateral ligament (ALL), and suggest that this ligament plays a significant role in the pathogenesis of ALRI of the knee joint. However, only limited knowledge about the biomechanical characteristics and tensile properties of the anterolateral ligament exists. The anterolateral ligament was dissected in four fresh-frozen human cadaveric specimens and all surrounding tissue removed. The initial length of the anterolateral ligament was measured using a digital caliper. Tensile tests with load to failure were performed using a materials testing machine. The explanted anterolateral ligaments were histologically examined to measure the cross-sectional area. The mean ultimate load to failure of the anterolateral ligament was 49.90 N (± 14.62 N) and the mean ultimate strain was 35.96% (± 4.47%). The mean length of the ligament was 33.08 mm (± 2.24) and the mean cross-sectional area was 1.54 m m (2) (± 0.48 m m (2)). Including the areal measurements the maximum tension was calculated to be 32.78 [Formula: see text] (± 4.04 [Formula: see text]). The anterolateral ligament is an anatomical structure with tensile properties that are considerably weaker compared to other peripheral structures of the knee. Knowledge of the anterolateral ligament's tensile strengths may help to better understand its function and with graft choices for reconstruction procedures.

The effects of sectioning the spring ligament on rearfoot stability and posterior tibial tendon efficiency.

PubMed

Jennings, Meagan M; Christensen, Jeffery C

2008-01-01

Posterior tibial tendon insufficiency has been implicated as a cause of adult acquired flatfoot. Multiple theories are debated as to whether or not a flatfoot deformity develops secondary to insufficiency of the posterior tibial tendon or of the ligamentous structures such as the spring ligament complex. This cadaveric study was undertaken in an attempt to determine the effect that sectioning the spring ligament complex has on foot stability, and whether engagement of the posterior tibial tendon would be able to compensate for the loss of the spring ligament complex. A 3-dimensional kinematic system and a custom-loading frame were used to quantify rotation about the talus, navicular, and calcaneus in 5 cadaveric specimens, before and after sectioning the spring ligament complex, while incremental tension was applied to the posterior tibial tendon. This study demonstrated that sectioning the spring ligament complex created instability in the foot for which the posterior tibial tendon was unable to compensate. Sectioning the spring ligament complex also produced significant changes in talar, navicular, and calcaneal rotations. During simulated midstance, the navicular plantarflexed, adducted, and everted; the talar head plantarflexed, adducted, and inverted; and the calcaneus plantarflexed, abducted, and everted, after sectioning the spring ligament complex. The results of this study indicate that the spring ligament complex is the major stabilizer of the arch during midstance and that the posterior tibial tendon is incapable of fully accommodating for its insufficiency, suggesting that the spring ligament complex should be evaluated and, if indicated, repaired in flatfoot reconstruction. 5.

Effect of culture complex of BMSCs and sodium hydroxide- and GRGDSPC-treated PET on the reconstruction of injured anterior cruciate ligament in a rabbit model

PubMed Central

Huang, Jianming; Chen, Fengrong; Jian, Guojian; Ye, Zhiyang; Wang, Zimin; Liu, Haoyuan; Kang, Yifan

2015-01-01

Ligament reconstruction is an effective therapy for anterior cruciate ligament (ACL) rupture. Polyethylene terephthalate (PET) artificial ligaments have recently gained popularity in clinical ACL reconstruction for its advantage in the improvement of keen function. However, the application of PET in clinical treatment is limited by its poor bioactivity and biocompatibility. Recently, bone marrow-derived mesenchymal stem cells (BMSCs) have been widely studied in regenerative medical therapy due to their multi-lineage differentiation. Previous study also indicated that BMSCs may promote the healing of tendon-bone interface of injured ligament. We speculate that BMSCs may enhance the curative effect of PET artificial ligament on the tendon-bone-healing in ligament reconstruction. In this study, the PET materials were first modified with sodium hydroxide hydrolysis and GRGDSPC peptide which was able to improve its bioactivity and biocompatibility. Then, the effects of modified PET materials on the adhesion, proliferation and differentiation of BMSCs were examined. The in vitro co-culture of BMSCs and modified PET showed the modified PET promoted the adhesion, proliferation and differentiation of BMSCs. Further, the effect of culture complex of BMSCs and modified PET artificial ligament co-culture system on the injured ligament reconstruction was investigated in vivo. Results showed not only better growth and differentiation of BMSCs but also satisfactory healing of the injured ligament was observed after implantation of this culture complex into the injured ligament of rabbits. Our study provides a brand-new solution for ACL reconstruction. PMID:26221227

A method to characterize average cervical spine ligament response based on raw data sets for implementation into injury biomechanics models.

PubMed

Mattucci, Stephen F E; Cronin, Duane S

2015-01-01

Experimental testing on cervical spine ligaments provides important data for advanced numerical modeling and injury prediction; however, accurate characterization of individual ligament response and determination of average mechanical properties for specific ligaments has not been adequately addressed in the literature. Existing methods are limited by a number of arbitrary choices made during the curve fits that often misrepresent the characteristic shape response of the ligaments, which is important for incorporation into numerical models to produce a biofidelic response. A method was developed to represent the mechanical properties of individual ligaments using a piece-wise curve fit with first derivative continuity between adjacent regions. The method was applied to published data for cervical spine ligaments and preserved the shape response (toe, linear, and traumatic regions) up to failure, for strain rates of 0.5s(-1), 20s(-1), and 150-250s(-1), to determine the average force-displacement curves. Individual ligament coefficients of determination were 0.989 to 1.000 demonstrating excellent fit. This study produced a novel method in which a set of experimental ligament material property data exhibiting scatter was fit using a characteristic curve approach with a toe, linear, and traumatic region, as often observed in ligaments and tendons, and could be applied to other biological material data with a similar characteristic shape. The resultant average cervical spine ligament curves provide an accurate representation of the raw test data and the expected material property effects corresponding to varying deformation rates. Copyright © 2014 Elsevier Ltd. All rights reserved.

Identification of different subsets of lung cells using Raman microspectroscopy and whole cell nucleus isolation.

PubMed

Pijanka, Jacek K; Stone, Nicholas; Rutter, Abigail V; Forsyth, Nicholas; Sockalingum, Ganesh D; Yang, Ying; Sulé-Suso, Josep

2013-09-07

Raman spectroscopy has been widely used to study its possible clinical application in cancer diagnosis. However, in order to make it into clinical practice, it is important that this technique is able not only to identify cancer cells from their normal counterparts, but also from the array of cells present in human tissues. To this purpose, we used Raman spectroscopy to assess whether this technique was able to differentiate not only between lung cancer cells and lung epithelial cells but also from lung fibroblasts. Furthermore, we studied whether the differences were due to cell lineage (epithelial versus fibroblast) or to different proliferative characteristics of cells, and where in the cell compartment these differences might reside. To answer these questions we studied cell cytoplasm, cell nucleus and isolated whole cell nuclei. Our data suggests that Raman spectroscopy can differentiate between lung cancer, lung epithelial cells and lung fibroblasts. More important, it can also differentiate between 2 cells from the same lineage (fibroblast) but with one of them rendered immortal and with an increased proliferative activity. Finally, it seems that the main spectral differences reside in the cell nucleus and that the study of isolated nuclei strengthens the differences between cells.

Regulation of HGF and SDF-1 expression by oral fibroblasts--implications for invasion of oral cancer.

PubMed

Daly, Aisling J; McIlreavey, Leanne; Irwin, Chris R

2008-07-01

Invasion and metastasis of oral squamous cell carcinoma (OSCC) is dependent on signals received from stromal fibroblasts present in the surrounding connective tissue. The aim of this study was to investigate the regulation of expression of two important signaling molecules--HGF and SDF-1--by both stromal fibroblasts and their 'activated' form, myofibroblasts, and to determine the role of these two factors in stimulating OSCC cell invasion in vitro. Fibroblasts and myofibroblasts produced similar levels of HGF and SDF-1. IL-1alpha and OSCC cell conditioned medium both stimulated HGF and SDF-1 expression, while TGF-beta(1) inhibited production of each factor. Myofibroblast-derived conditioned medium stimulated OSCC cell invasion through matrigel. Blocking antibodies to both HGF and SDF-1 reduced the level of invasion. In fibroblast-free organotypic raft cultures, addition of HGF and SDF-1 stimulated OSCC cell invasion into the underlying collagen gel, although the pattern of invasion differed from that induced by fibroblasts. Fibroblast-derived HGF and SDF-1 appear to play central roles in the reciprocal interactions between OSCC cells and underlying stromal fibroblasts leading to the local invasion of oral cancer.

Key Regulatory Role of Dermal Fibroblasts in Pigmentation as Demonstrated Using a Reconstructed Skin Model: Impact of Photo-Aging

PubMed Central

Duval, Christine; Cohen, Catherine; Chagnoleau, Corinne; Flouret, Virginie; Bourreau, Emilie; Bernerd, Françoise

2014-01-01

To study cutaneous pigmentation in a physiological context, we have previously developed a functional pigmented reconstructed skin model composed of a melanocyte-containing epidermis grown on a dermal equivalent comprising living fibroblasts. The present studies, using the same model, aimed to demonstrate that dermal fibroblasts influence skin pigmentation up to the macroscopic level. The proof of principle was performed with pigmented skins differing only in the fibroblast component. First, the in vitro system was reconstructed with or without fibroblasts in order to test the global influence of the presence of this cell type. We then assessed the impact of the origin of the fibroblast strain on the degree of pigmentation using fetal versus adult fibroblasts. In both experiments, impressive variation in skin pigmentation at the macroscopic level was observed and confirmed by quantitative parameters related to skin color, melanin content and melanocyte numbers. These data confirmed the responsiveness of the model and demonstrated that dermal fibroblasts do indeed impact the degree of skin pigmentation. We then hypothesized that a physiological state associated with pigmentary alterations such as photo-aging could be linked to dermal fibroblasts modifications that accumulate over time. Pigmentation of skin reconstructed using young unexposed fibroblasts (n = 3) was compared to that of tissues containing natural photo-aged fibroblasts (n = 3) which express a senescent phenotype. A stimulation of pigmentation in the presence of the natural photo-aged fibroblasts was revealed by a significant increase in the skin color (decrease in Luminance) and an increase in both epidermal melanin content and melanogenic gene expression, thus confirming our hypothesis. Altogether, these data demonstrate that the level of pigmentation of the skin model is influenced by dermal fibroblasts and that natural photo-aged fibroblasts can contribute to the hyperpigmentation that is associated with photo-aging. PMID:25490395

What to Do with the Spring Ligament.

PubMed

Steginsky, Brian; Vora, Anand

2017-09-01

The spring ligament complex is an important static restraint of the medial longitudinal arch of the foot and its failure has been associated with progressive flatfoot deformity. Reconstruction of the spring ligament complex is most appropriate in stage II posterior tibial tendon dysfunction, before severe peritalar subluxation and rigid deformity develops. Although an understanding of the spring ligament complex and its contribution to medial arch stability has grown, there is no unanimously accepted surgical technique that has consistently demonstrated satisfactory outcomes. This article reviews the pathoanatomy of the spring ligament complex and the role of spring ligament reconstruction in acquired flatfoot deformity, and highlights current research. Copyright © 2017 Elsevier Inc. All rights reserved.

Ideal orthodontic alignment load relationships based on periodontal ligament stress.

PubMed

Viecilli, R F; Burstone, C J

2015-04-01

To test the hypothesis that periodontal ligament (PDL) stress relationships that yield resistance numbers representing load proportions between different teeth depend on alignment load type. Finite element models of all teeth, except the third molars, were produced. Four different types of loads were applied, and the third principal stresses of different teeth in standardized areas of most compression were calculated. Based on these results, resistance numbers, representing the load proportions for each tooth derived from PDL stress, were determined. The third principal stress values for typical alignment loads in the areas of most stress were very different for different load types for each tooth. Differences in resistance numbers between teeth also varied with different loads. Resistance numbers, that is, load proportion numbers between teeth to achieve similar stress at the compressive PDL zone, depend on the type of applied load. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Influence of thermofixation on artificial ACL ligament dimensional and mechanical properties

NASA Astrophysics Data System (ADS)

Ben Abdessalem, S.; Jedda, H.; Skhiri, S.; Karray, S.; Dahmen, J.; Boughamoura, H.

2005-11-01

The anterior cruciate ligament (ACL) is the major articular ligamentous structure of the knee, it functions as a joint stabilizer. When ruptured, the natural ACL ligament can be replaced by a textile synthetic ligament such as a braid, knitted cord, or woven cord. Theses structures are composed of biocompatible materials such as polyester or Gore-Tex filaments. The success of an ACL replacement is widely linked to its mechanical and dimensional properties such as tensile strength, dimensional stability and resistance to abrasion. We introduced an additional treatment in the manufacturing of textile ACL ligaments based on the thermofixation of the textile structure by using textile industry stabilization techniques. Boiling water, saturated vapor and dry heat have been tested to stabilize a braided ligament made of Dacron polyester. The application of these three techniques led to shrinkage and an increase of breaking strength of the textile structure.

The in vitro viability and growth of fibroblasts cultured in the presence of different bone grafting materials (NanoBone and Straumann Bone Ceramic).

PubMed

Kauschke, E; Rumpel, E; Fanghänel, J; Bayerlein, T; Gedrange, T; Proff, P

2006-02-01

Different clinical applications, including dentistry, are making increasing demands on bone grafting material. In the present study we have analysed the viability, proliferation and growth characteristics of fibroblasts cultured in vitro together with two different bone grafting materials, NanoBone and Straumann Bone Ceramic, over a period of 24 and 28 days respectively. Viability was measured at least every 72 hours by using the alamarBlue assay, a test that measures quantitatively cell proliferation and viability but does not require cell fixation or extraction. After one week of culture fibroblast viability was as high as in controls for both grafting materials and remained high (> 90%) for the duration of the experiment. Cell growth was evaluated microscopically. Scanning electron microscopy revealed a dense fibroblast growth at the surface of both bone grafting materials after three weeks of in vitro culture. Generally, our in vitro analyses contribute to further insights into cell - scaffold interactions.

Wound-healing potential of human umbilical cord blood-derived mesenchymal stromal cells in vitro--a pilot study.

PubMed

You, Hi-Jin; Namgoong, Sik; Han, Seung-Kyu; Jeong, Seong-Ho; Dhong, Eun-Sang; Kim, Woo-Kyung

2015-11-01

Our previous studies demonstrated that human bone marrow-derived mesenchymal stromal cells have great potential for wound healing. However, it is difficult to clinically utilize cultured stem cells. Recently, human umbilical cord blood-derived mesenchymal stromal cells (hUCB-MSCs) have been commercialized for cartilage repair as a first cell therapy product that uses allogeneic stem cells. Should hUCB-MSCs have a superior effect on wound healing as compared with fibroblasts, which are the main cell source in current cell therapy products for wound healing, they may possibly replace fibroblasts. The purpose of this in vitro study was to compare the wound-healing activity of hUCB-MSCs with that of fibroblasts. This study was particularly designed to compare the effect of hUCB-MSCs on diabetic wound healing with those of allogeneic and autologous fibroblasts. Healthy (n = 5) and diabetic (n = 5) fibroblasts were used as the representatives of allogeneic and autologous fibroblasts for diabetic patients in the control group. Human UCB-MSCs (n = 5) were used in the experimental group. Cell proliferation, collagen synthesis and growth factor (basic fibroblast growth factor, vascular endothelial growth factor and transforming growth factor-β) production were compared among the three cell groups. Human UCB-MSCs produced significantly higher amounts of vascular endothelial growth factor and basic fibroblast growth factor when compared with both fibroblast groups. Human UCB-MSCs were superior to diabetic fibroblasts but not to healthy fibroblasts in collagen synthesis. There were no significant differences in cell proliferation and transforming growth factor-β production. Human UCB-MSCs may have greater capacity for diabetic wound healing than allogeneic or autologous fibroblasts, especially in angiogenesis. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Replacement of the anterior cruciate ligament with a bone-ligament-bone anterior cruciate ligament allograft in dogs.

PubMed

Vasseur, P B; Rodrigo, J J; Stevenson, S; Clark, G; Sharkey, N

1987-06-01

Acute replacement of the canine anterior cruciate ligament (ACL) with a frozen, bone-ligament-bone anterior cruciate ligament preparation was studied using biochemical, immunologic, and biomechanical testing methods. Nine dogs were used for the study, six dogs received allografts and three received autografts. No tissue antigen matching was performed. All nine dogs were killed nine months after surgery. Necropsy examination revealed that the ACL was not present in three joints (one autograft, two allografts). The two autograft and four allograft ligaments available for mechanical testing sustained mean maximum loads that were 10% and 14%, respectively, of the mean maximum loads sustained by the contralateral ACL. Autoradiography indicated that cellular activity was more pronounced in the autograft specimens. Hydroxyproline uptake was 200% and 45% of normal in the autograft and allograft ligaments, respectively. Both autograft and allograft specimens were producing Type I collagen at the time of killing. Antidonor dog leukocyte antigen (DLA) antibody was detected in the synovial fluid taken at the time of killing from six of six dogs that received allografts and in zero of three dogs that received autografts.

Inducing bioactivity of dental ceramic/bioactive glass composites by Nd:YAG laser.

PubMed

Beketova, Anastasia; Poulakis, Nikolaos; Bakopoulou, Athina; Zorba, Triantafillia; Papadopoulou, Lambrini; Christofilos, Dimitrios; Kantiranis, Nikolaos; Zachariadis, George A; Kontonasaki, Eleana; Kourouklis, Gerasimos A; Paraskevopoulos, Konstantinos M; Koidis, Petros

2016-11-01

Aims of this study were to investigate the optimal conditions of laser irradiation of a novel Bioactive Glass/Dental Ceramic-BP67 composite for acceleration of hydroxyapatite-HA formation and to assess cellular responses on the precipitated HA region. BP67 (Bioactive Glass: 33.3%, Dental Ceramic: 66.7%) was fabricated by the sol-gel method. A laser assisted biomimetic-LAB process was applied to BP67 sintered specimens immersed in 1.5-times concentrated simulated body fluid-1.5×-SBF. The effect of various energy densities of pulsed nanosecond Nd-YAG (1064nm) laser and irradiation exposure times (30min, 1 and 3h) were evaluated for HA precipitation. The HA film was characterized by FTIR, XRD, SEM and micro Raman techniques. ICP-AES was used for revealing changes in chemical composition of the 1.5×-SBF during irradiation. Cell viability and morphological characteristics of periodontal ligament fibroblasts-PDLFs, human gingival fibroblasts-HGFs and SAOS-2 osteoblasts on the HA surface were evaluated by MTT assays and SEM. At optimal energy fluence of 1.52J/cm 2 and irradiation time for 3h followed by immersion in 1.5×-SBF at 60°C, a dense HA layer was formed on laser-irradiated BP67 within 7 days. The resulting HA film was tightly bonded to the underlying substrate and had mineral composition similar to cementum. MTT assay showed a consistent reduction of cell proliferation on the HA layer in comparison to conventional control ceramic and BP67 for all 3 cell lines studied. These findings suggest LAB is an effective method for acceleration of HA formation on materials with low bioactivity, while cellular responses need further investigation. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Generation and periodontal differentiation of human gingival fibroblasts-derived integration-free induced pluripotent stem cells

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

Yin, Xiaohui; Peking University Stem Cell Research Center and Department of Cell Biology, School of Basic Medical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191; Li, Yang

Induced pluripotent stem cells (iPSCs) have been recognized as a promising cell source for periodontal tissue regeneration. However, the conventional virus-based reprogramming approach is associated with a high risk of genetic mutation and limits their therapeutic utility. Here, we successfully generated iPSCs from readily accessible human gingival fibroblasts (hGFs) through an integration-free and feeder-free approach via delivery of reprogramming factors of Oct4, Sox2, Klf4, L-myc, Lin28 and TP53 shRNA with episomal plasmid vectors. The iPSCs presented similar morphology and proliferation characteristics as embryonic stem cells (ESCs), and expressed pluripotent markers including Oct4, Tra181, Nanog and SSEA-4. Additionally, these cells maintainedmore » a normal karyotype and showed decreased CpG methylation ratio in the promoter regions of Oct4 and Nanog. In vivo teratoma formation assay revealed the development of tissues representative of three germ layers, confirming the acquisition of pluripotency. Furthermore, treatment of the iPSCs in vitro with enamel matrix derivative (EMD) or growth/differentiation factor-5 (GDF-5) significantly up-regulated the expression of periodontal tissue markers associated with bone, periodontal ligament and cementum respectively. Taken together, our data demonstrate that hGFs are a valuable cell source for generating integration-free iPSCs, which could be sequentially induced toward periodontal cells under the treatment of EMD and GDF-5. - Highlights: • Integration-free iPSCs are successfully generated from hGFs via an episomal approach. • EMD promotes differentiation of the hGFs-derived iPSCs toward periodontal cells. • GDF-5 promotes differentiation of the hGFs-derived iPSCs toward periodontal cells. • hGFs-derived iPSCs could be a promising cell source for periodontal regeneration.« less

Synthesis and Cytotoxic Activities of Difluoro-Dimethoxy Chalcones.

PubMed

Yamali, Cem; Gul, Halise Inci; Ozgun, Dilan Ozmen; Sakagam, Hiroshi; Umemura, Naoki; Kazaz, Cavit; Gul, Mustafa

2017-01-01

Although anticancer chemotherapeutics are available in markets, side effects related to the drugs in clinical use lead to researchers to investigate new drug candidates which are more safe, potent and selective than others. Chalcones are popular with their anticancer activities with the several reported mechanisms including inhibition of angiogenesis, inhibition of tubulin polymerization, and induction of apoptosis etc. This study was focused on to synthesize of 1-(2,4/2,6-difluorophenyl)-3-(2,3/2,4/2,5/3,4- dimethoxyphenyl)-2-propen-1-ones (1-8) and investigate their cytotoxic properties with possible mechanism of action. The compounds were synthesized by Claisen-Schmidt condensation. The chemical structures were confirmed by 1H NMR, 13C NMR, DEPT, COSY, HMQC, HMBC, 19F NMR and HRMS. In vitro cytotoxic effects of the compounds against human tumour cell lines [gingival carcinoma (Ca9-22), oral squamous cell carcinoma (HSC-2)] and human normal oral cells [gingival fibroblasts (HGF), periodontal ligament fibroblasts (HPLF)] were evaluated via MTT test. All compounds had higher cytotoxicity than reference compound 5-Fluorouracil (5-FU). The compounds 3-7 had higher potency selectivity expression values (PSE) than 5-FU and PSE values of the compounds were over 100. All chalcone derivatives seem good candidates for further studies according to very remarkable and high PSE values. It was clearly demonstrated that compound 7 can induce early apoptosis at a concentration of 10 µM and dose-dependent late apoptosis starting at 10 µM. Compound 7 induced cleavage of the apoptosis marker PARP. The results indicate that new chalcones reported here can promote apoptosis in human tumour cell lines. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Investigation of whiplash injuries in the upper cervical spine using a detailed neck model.

PubMed

Fice, Jason B; Cronin, Duane S

2012-04-05

Whiplash injuries continue to have significant societal cost; however, the mechanism and location of whiplash injury is still under investigation. Recently, the upper cervical spine ligaments, particularly the alar ligament, have been identified as a potential whiplash injury location. In this study, a detailed and validated explicit finite element model of a 50th percentile male cervical spine in a seated posture was used to investigate upper cervical spine response and the potential for whiplash injury resulting from vehicle crash scenarios. This model was previously validated at the segment and whole spine levels for both kinematics and soft tissue strains in frontal and rear impact scenarios. The model predicted increasing upper cervical spine ligament strain with increasing impact severity. Considering all upper cervical spine ligaments, the distractions in the apical and alar ligaments were the largest relative to their failure strains, in agreement with the clinical findings. The model predicted the potential for injury to the apical ligament for 15.2 g frontal or 11.7 g rear impacts, and to the alar ligament for a 20.7 g frontal or 14.4 g rear impact based on the ligament distractions. Future studies should consider the effect of initial occupant position on ligament distraction. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hindlimb unloading alters ligament healing

NASA Technical Reports Server (NTRS)

Provenzano, Paolo P.; Martinez, Daniel A.; Grindeland, Richard E.; Dwyer, Kelley W.; Turner, Joanne; Vailas, Arthur C.; Vanderby, Ray Jr

2003-01-01

We investigated the hypothesis that hindlimb unloading inhibits healing in fibrous connective tissue such as ligament. Male rats were assigned to 3- and 7-wk treatment groups with three subgroups each: sham control, ambulatory healing, and hindlimb-suspended healing. Ambulatory and suspended animals underwent surgical rupture of their medial collateral ligaments, whereas sham surgeries were performed on control animals. After 3 or 7 wk, mechanical and/or morphological properties were measured in ligament, muscle, and bone. During mechanical testing, most suspended ligaments failed in the scar region, indicating the greatest impairment was to ligament and not to bone-ligament insertion. Ligament testing revealed significant reductions in maximum force, ultimate stress, elastic modulus, and low-load properties in suspended animals. In addition, femoral mineral density, femoral strength, gastrocnemius mass, and tibialis anterior mass were significantly reduced. Microscopy revealed abnormal scar formation and cell distribution in suspended ligaments with extracellular matrix discontinuities and voids between misaligned, but well-formed, collagen fiber bundles. Hence, stress levels from ambulation appear unnecessary for formation of fiber bundles yet required for collagen to form structurally competent continuous fibers. Results support our hypothesis that hindlimb unloading impairs healing of fibrous connective tissue. In addition, this study provides compelling morphological evidence explaining the altered structure-function relationship in load-deprived healing connective tissue.

What does the transverse carpal ligament contribute to carpal stability?

PubMed

Vanhees, Matthias; Verstreken, Frederik; van Riet, Roger

2015-02-01

Background The transverse carpal ligament is well known for its involvement in carpal tunnel syndrome, and sectioning of this ligament remains the definite treatment for this pathology. Some authors believe that the transverse carpal ligament is an important stabilizer of the carpal arch, whereas others do not consider it to be significant. Several studies have been performed, both in vivo and in in vitro. Sectioning of the transverse carpal ligament does not seem to have any effect on the width of the carpal arch in the unloaded condition. However, patients will load the arch during their activities of daily living. Materials and Methods A cadaveric study was done with distraction of the carpal bones before and after sectioning the transverse carpal ligament. Results With the transverse carpal ligament intact, the carpal arch is mobile, with distraction leading up to 50% widening of the arch. Sectioning of the transverse carpal ligament resulted in a significant widening of the carpal arch by a further 30%. Conclusions Loading of the carpal arch after sectioning of the transeverse carapal ligament leads to a significant increase in intracarpal mobility. This will inevitably influence carpal kinematics in the patient and might be responsible for some complications after simple carpal tunnel releases, such as pillar pain, palmar tenderness, and loss of grip strength.

Arthroscopic procedures and therapeutic results of anatomical reconstruction of the coracoclavicular ligaments for acromioclavicular Joint dislocation.

PubMed

Takase, K; Yamamoto, K

2016-09-01

Surgical treatment is recommended for type 5 acromioclavicular joint dislocation on Rockwood's classification. We believe that anatomic repair of the coracoclavicular ligaments best restores the function of the acromioclavicular joint. We attempted to correctly reconstruct the anatomy of the coracoclavicular ligaments under arthroscopy, and describe the minimally invasive arthroscopic procedure. There were 22 patients; mean age at surgery, 38.1 years. Mean time to surgery was 13.2 days. Mean follow-up was 3 years 2 months. The palmaris longus tendon was excised from the ipsilateral side to replace the conoid ligament, while artificial ligament was used for reconstructing the trapezoid ligament. Both ligament reconstructions were performed arthroscopically. No temporary fixation of the acromioclavicular joint was performed. On postoperative radiographic evaluation, 4 patients showed subluxation and 2 showed dislocation of the acromioclavicular joint; the other 16 patients had maintained reduction at the final consultation. MR images 1year after surgery clearly revealed the reconstructed ligaments in 19 patients. Only 1 patient showed osteoarthritis of the acromioclavicular joint. Although it requires resection of the ipsilateral palmaris longus for grafting, we believe that anatomic reconstruction of both coracoclavicular ligaments best restores the function of the acromioclavicular joint. 4. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Features extraction in anterior and posterior cruciate ligaments analysis.

PubMed

Zarychta, P

2015-12-01

The main aim of this research is finding the feature vectors of the anterior and posterior cruciate ligaments (ACL and PCL). These feature vectors have to clearly define the ligaments structure and make it easier to diagnose them. Extraction of feature vectors is obtained by analysis of both anterior and posterior cruciate ligaments. This procedure is performed after the extraction process of both ligaments. In the first stage in order to reduce the area of analysis a region of interest including cruciate ligaments (CL) is outlined in order to reduce the area of analysis. In this case, the fuzzy C-means algorithm with median modification helping to reduce blurred edges has been implemented. After finding the region of interest (ROI), the fuzzy connectedness procedure is performed. This procedure permits to extract the anterior and posterior cruciate ligament structures. In the last stage, on the basis of the extracted anterior and posterior cruciate ligament structures, 3-dimensional models of the anterior and posterior cruciate ligament are built and the feature vectors created. This methodology has been implemented in MATLAB and tested on clinical T1-weighted magnetic resonance imaging (MRI) slices of the knee joint. The 3D display is based on the Visualization Toolkit (VTK). Copyright © 2015 Elsevier Ltd. All rights reserved.

Diversity of Interstitial Lung Fibroblasts Is Regulated by Platelet-Derived Growth Factor Receptor α Kinase Activity.

PubMed

Green, Jenna; Endale, Mehari; Auer, Herbert; Perl, Anne-Karina T

2016-04-01

Epithelial-mesenchymal cell interactions and factors that control normal lung development are key players in lung injury, repair, and fibrosis. A number of studies have investigated the roles and sources of epithelial progenitors during lung regeneration; such information, however, is limited in lung fibroblasts. Thus, understanding the origin, phenotype, and roles of fibroblast progenitors in lung development, repair, and regeneration helps address these limitations. Using a combination of platelet-derived growth factor receptor α-green fluorescent protein (PDGFRα-GFP) reporter mice, microarray, real-time polymerase chain reaction, flow cytometry, and immunofluorescence, we characterized two distinct interstitial resident fibroblasts, myo- and matrix fibroblasts, and identified a role for PDGFRα kinase activity in regulating their activation during lung regeneration. Transcriptional profiling of the two populations revealed a myo- and matrix fibroblast gene signature. Differences in proliferation, smooth muscle actin induction, and lipid content in the two subpopulations of PDGFRα-expressing fibroblasts during alveolar regeneration were observed. Although CD140α(+)CD29(+) cells behaved as myofibroblasts, CD140α(+)CD34(+) appeared as matrix and/or lipofibroblasts. Gain or loss of PDGFRα kinase activity using the inhibitor nilotinib and a dominant-active PDGFRα-D842V mutation revealed that PDGFRα was important for matrix fibroblast differentiation. We demonstrated that PDGFRα signaling promotes alveolar septation by regulating fibroblast activation and matrix fibroblast differentiation, whereas myofibroblast differentiation was largely PDGFRα independent. These studies provide evidence for the phenotypic and functional diversity as well as the extent of specificity of interstitial resident fibroblasts differentiation during regeneration after partial pneumonectomy.

Diversity of Interstitial Lung Fibroblasts Is Regulated by Platelet-Derived Growth Factor Receptor α Kinase Activity

PubMed Central

Green, Jenna; Endale, Mehari; Auer, Herbert

2016-01-01

Epithelial–mesenchymal cell interactions and factors that control normal lung development are key players in lung injury, repair, and fibrosis. A number of studies have investigated the roles and sources of epithelial progenitors during lung regeneration; such information, however, is limited in lung fibroblasts. Thus, understanding the origin, phenotype, and roles of fibroblast progenitors in lung development, repair, and regeneration helps address these limitations. Using a combination of platelet-derived growth factor receptor α–green fluorescent protein (PDGFRα-GFP) reporter mice, microarray, real-time polymerase chain reaction, flow cytometry, and immunofluorescence, we characterized two distinct interstitial resident fibroblasts, myo- and matrix fibroblasts, and identified a role for PDGFRα kinase activity in regulating their activation during lung regeneration. Transcriptional profiling of the two populations revealed a myo- and matrix fibroblast gene signature. Differences in proliferation, smooth muscle actin induction, and lipid content in the two subpopulations of PDGFRα-expressing fibroblasts during alveolar regeneration were observed. Although CD140α+CD29+ cells behaved as myofibroblasts, CD140α+CD34+ appeared as matrix and/or lipofibroblasts. Gain or loss of PDGFRα kinase activity using the inhibitor nilotinib and a dominant-active PDGFRα-D842V mutation revealed that PDGFRα was important for matrix fibroblast differentiation. We demonstrated that PDGFRα signaling promotes alveolar septation by regulating fibroblast activation and matrix fibroblast differentiation, whereas myofibroblast differentiation was largely PDGFRα independent. These studies provide evidence for the phenotypic and functional diversity as well as the extent of specificity of interstitial resident fibroblasts differentiation during regeneration after partial pneumonectomy. PMID:26414960

The use of synthetic ligaments in the design of an enhanced stability total knee joint replacement.

PubMed

Stokes, Michael D; Greene, Brendan C; Pietrykowski, Luke W; Gambon, Taylor M; Bales, Caroline E; DesJardins, John D

2018-03-01

Current total knee replacement designs work to address clinically desired knee stability and range of motion through a balance of retained anatomy and added implant geometry. However, simplified implant geometries such as bearing surfaces, posts, and cams are often used to replace complex ligamentous constraints that are sacrificed during most total knee replacement procedures. This article evaluates a novel total knee replacement design that incorporates synthetic ligaments to enhance the stability of the total knee replacement system. It was hypothesized that by incorporating artificial cruciate ligaments into a total knee replacement design at specific locations and lengths, the stability of the total knee replacement could be significantly altered while maintaining active ranges of motion. The ligament attachment mechanisms used in the design were evaluated using a tensile test, and determined to have a safety factor of three with respect to expected ligamentous loading in vivo. Following initial computational modeling of possible ligament orientations, a physical prototype was constructed to verify the function of the design by performing anterior/posterior drawer tests under physiologic load. Synthetic ligament configurations were found to increase total knee replacement stability up to 94% compared to the no-ligament case, while maintaining total knee replacement flexion range of motion between 0° and 120°, indicating that a total knee replacement that incorporates synthetic ligaments with calibrated location and lengths should be able to significantly enhance and control the kinematic performance of a total knee replacement system.

A framework for parametric modeling of ankle ligaments to determine the in situ response under gross foot motion.

PubMed

Nie, Bingbing; Panzer, Matthew Brian; Mane, Adwait; Mait, Alexander Ritz; Donlon, John-Paul; Forman, Jason Lee; Kent, Richard Wesley

2016-09-01

Ligament sprains account for a majority of injuries to the foot and ankle complex, but ligament properties have not been understood well due to the difficulties in replicating the complex geometry, in situ stress state, and non-uniformity of the strain. For a full investigation of the injury mechanism, it is essential to build up a foot and ankle model validated at the level of bony kinematics and ligament properties. This study developed a framework to parameterize the ligament response for determining the in situ stress state and heterogeneous force-elongation characteristics using a finite element ankle model. Nine major ankle ligaments and the interosseous membrane were modeled as discrete elements corresponding functionally to the ligamentous microstructure of collagen fibers and having parameterized toe region and stiffness at the fiber level. The range of the design variables in the ligament model was determined from existing experimental data. Sensitivity of the bony kinematics to each variable was investigated by design of experiment. The results highlighted the critical role of the length of the toe region of the ligamentous fibers on the bony kinematics with the cumulative influence of more than 95%, while the fiber stiffness was statistically insignificant with an influence of less than 1% under the given variable range and loading conditions. With the flexibility of variable adjustment and high computational efficiency, the presented ankle model was generic in nature so as to maximize its applicability to capture the individual ligament behaviors in future studies.

Fiber-based modeling of in situ ankle ligaments with consideration of progressive failure.

PubMed

Nie, Bingbing; Forman, Jason L; Panzer, Matthew B; Mait, Alexander R; Donlon, John-Paul; Kent, Richard W

2017-08-16

Ligament sprains account for a majority of injuries to the foot and ankle complex among athletic populations. The infeasibility of measuring the in situ response and load paths of individual ligaments has precluded a complete characterization of their mechanical behavior via experiment. In the present study a fiber-based modeling approach of in situ ankle ligaments was developed and validated for determining the heterogeneous force-elongation characteristics and the consequent injury patterns. Nine major ankle ligaments were modeled as bundles of discrete elements, corresponding functionally to the structure of collagen fibers. To incorporate the progressive nature of ligamentous injury, the limit strain at the occurrence of fiber failure was described by a distribution function ranging from 12% to 18% along the width of the insertion site. The model was validated by comparing the structural kinetic and kinematic response obtained experimentally and computationally under well-controlled foot rotations. The simulation results replicated the 6 degree-of-freedom bony motion and ligamentous injuries and, by implication, the in situ deformations of the ligaments. Gross stiffness of the whole ligament derived from the fibers was comparable to existing experimental data. The present modeling approach provides a biomechanically realistic, interpretable and computationally efficient way to characterize the in situ ligament slack, sequential and heterogeneous uncrimping of collagen fascicles and failure propagation as the external load is applied. Applications of this model include functional ankle joint mechanics, injury prevention and countermeasure design for athletes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dermis, acellular dermal matrix, and fibroblasts from different layers of pig skin exhibit different profibrotic characteristics: evidence from in vivo study

PubMed Central

Zuo, Yanhai; Lu, Shuliang

2017-01-01

To explore the profibrotic characteristics of the autografted dermis, acellular dermal matrix, and dermal fibroblasts from superficial/deep layers of pig skin, 93 wounds were established on the dorsa of 7 pigs. 72 wounds autografted with the superficial/deep dermis and acellular dermal matrix served as the superficial/deep dermis and acellular dermal matrix group, respectively, and were sampled at 2, 4, and 8 weeks post-wounding. 21 wounds autografted with/without superficial/deep dermal fibroblasts served as the superficial/deep dermal fibroblast group and the control group, respectively, and were sampled at 2 weeks post-wounding. The hematoxylin and eosin staining showed that the wounded skin thicknesses in the deep dermis group (superficial acellular dermal matrix group) were significantly greater than those in the superficial dermis group (deep acellular dermal matrix group) at each time point, the thickness of the cutting plane in the deep dermal fibroblast group was significantly greater than that in the superficial dermal fibroblast group and the control group. The western blots showed that the α-smooth muscle actin expression in the deep dermis group (superficial acellular dermal matrix group) was significantly greater than that in the superficial dermis group (deep acellular dermal matrix group) at each time point. In summary, the deep dermis and dermal fibroblasts exhibited more profibrotic characteristics than the superficial ones, on the contrary, the deep acellular dermal matrix exhibited less profibrotic characteristics than the superficial one. PMID:28423561

Blue light-irradiated human keloid fibroblasts: an in vitro study

NASA Astrophysics Data System (ADS)

Magni, Giada; Rossi, Francesca; Tatini, Francesca; Pini, Roberto; Coppi, Elisabetta; Cherchi, Federica; Fusco, Irene; Pugliese, Anna Maria; Pedata, Felicita; Fraccalvieri, Marco; Gasperini, Stefano; Pavone, Francesco S.; Tripodi, Cristina; Alfieri, Domenico; Targetti, Lorenzo

2018-02-01

Blue LED light irradiation is currently under investigation because of its effect in wound healing improvement. In this context, several mechanisms of action are likely to occur at the same time, consistently with the presence of different light absorbers within the skin. In our previous studies we observed the wound healing in superficial abrasions in an in vivo murine model. The results evidenced that both inflammatory infiltrate and myofibroblasts activity increase after irradiation. In this study we focused on evaluating the consequences of light absorption in fibroblasts from human cells culture: they play a key role in wound healing, both in physiological conditions and in pathological ones, such as keloid scarring. In particular we used keloids fibroblasts as a new target in order to investigate a possible metabolic or cellular mechanism correlation. Human keloid tissues were excised during standard surgery and immediately underwent primary cell culture extraction. Fibroblasts were allowed to grow in the appropriate conditions and then exposed to blue light. A metabolic colorimetric test (WST-8) was then performed. The tests evidenced an effect in mitochondrial activity, which could be modulated by the duration of the treatment. Electrophysiology pointed out a different behavior of irradiated fibroblasts. In conclusion, the Blue LED light affects the metabolic activity of fibroblasts and thus the cellular proliferation rate. No specific effect was found on keloid fibroblasts, thus indicating a very basic intracellular component, such as cytochromes, being the target of the treatment.