These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Nucleus pulposus cells derived IGF-1 and MCP-1 enhance osteoclastogenesis and vertebrae disruption in lumbar disc herniation  

PubMed Central

Study design: Chronic strained lumbar disc herniation (LDH) cases were classified into bulging LDH, herniated LDH and prolapse LDH types according to imaging examination, and vertebrae disruptions were evaluated. Cytokines derived from the nucleus pulposus cells were detected, and their effects on osteoclastogenesis, as well as the mechanisms involved, were studied via an in vitro osteoclast differentiation system. Objective: To clarify the mechanisms of lumbar vertebrae resorption induced by lumbar herniation. Summary and background data: Chronic strained lumbar disc herniation induced vertebrae erosion exacerbates quality of patients’ life and clinical outcome. Although nucleus pulposus cells derived cytokines were reported to play an important role in this pathogenesis, the fundamental mechanisms underlying this process are still unclear. Methods: Chronic strained lumbar disc herniation patients were diagnosed with CT scan and T2-weighted magnetic resonance imaging. RNA was extracted from 192 surgical specimens of the herniated lumbar disc and 29 surgical excisions of the lumbar disc from spinal injury patients. The expressions of osteoclastogenesis related cytokines and chemokines were examined using real time PCR. Monocytes were induced into osteoclast with M-CSF and RANKL in vitro, while the IGF-1 and MCP-1 were added into the differentiation procedure in order to evaluate the effects and explore the molecular mechanisms. Results: Vertebrae erosion had a positive relationship with lumbar disc herniation severity types. In all of the osteoclastogenesis related cytokines, the IGF-1 and MCP-1 were the most highly expressed in the nucleus pulposus cells. IGF-1 enhances activation of NF-kB signaling directly, but MCP-1 upregulated the expression of RANK, so that enhanced cellular sensitivity to RANKL resulted in increasing osteoclastogenesis and activity. Conclusion: Lumbar herniation induced overexpression of IGF-1 and MCP-1 in nucleus pulposus cells aggravated vertebral erosions. Hence, this study suggests that targeting osteoclastogenesis related cytokines has potential clinical significance in the treatment of lumbar disc herniation patients.

Zhu, Zhongjiao; Huang, Peng; Chong, Yanxue; George, Suraj K; Wen, Bingtao; Han, Na; Liu, Zhiqiang; Kang, Lixin; Lin, Nie

2014-01-01

2

Osseous erosion by herniated nucleus pulposus mimicking intraspinal tumor: a case report  

PubMed Central

Erosion of spinal osseous structure, so-called scalloping, has been rarely reported associated with herniated nucleus pulposus (HNP). We report a rare case of HNP causing erosion of the spinal osseous structure (including lamina). The patient was an 81-year-old woman with 3-year history of low-back pain and left leg radiating pain. Muscle weakness of the left leg was also apparent. Computed tomography following myelography showed severe compression of the dural sac at the level of L3–L4; furthermore, erosion of the lamina, pedicle, and vertebral body was noted, indicating that the space-occupying mass was most probably a tumorous lesion. The mass also showed calcification inside. During the surgery, the mass was confirmed to be an HNP with calcification. Following resection, the pain disappeared. Surgeons should be aware of the possibility of scalloping of the vertebrae caused by HNP mimicking a tumorous lesion. PMID:21103903

Yoshioka, Shinji; Sakai, Toshinori; Tamura, Tatsuya; Kosaka, Hirofumi; Yasui, Natsuo

2010-01-01

3

Rheological characterization of the nucleus pulposus and dense collagen scaffolds intended for functional replacement  

Microsoft Academic Search

Lumbar discectomy is an effective therapy for neurological decompression in patients suffering from sciatica due to a herniated nucleus pulposus (NP). However, high numbers of patients suffering from persisting postoperative low back pain have resulted in many strategies targeting the regeneration of the NP. For successful regeneration, the stiffness of scaffolds is increasingly recognized as a potent mechanical cue for

J. L. Bron; G. H. Koenderink; V. Everts; T. H. Smit

2009-01-01

4

Composite hydrogels for nucleus pulposus tissue engineering  

Microsoft Academic Search

Tissue engineering offers a paradigm shift in the treatment of back pain. Engineered intervertebral discs could replace degenerated tissue and overcome the limitations of current treatments, which substantially alter the biomechanical properties of the spine. The centre of the disc, the nucleus pulposus, is an amorphous gel with a large bound water content and it can resist substantial compressive loads.

Daniel G. T. Strange; Michelle L. Oyen

5

Identification of novel nucleus pulposus markers  

PubMed Central

Mesenchymal stem-cell based therapies have been proposed as novel treatments for intervertebral disc degeneration, a prevalent and disabling condition associated with back pain. The development of these treatment strategies, however, has been hindered by the incomplete understanding of the human nucleus pulposus phenotype and by an inaccurate interpretation and translation of animal to human research. This review summarises recent work characterising the nucleus pulposus phenotype in different animal models and in humans and integrates their findings with the anatomical and physiological differences between these species. Understanding this phenotype is paramount to guarantee that implanted cells restore the native functions of the intervertebral disc. Cite this article: Bone Joint Res 2013;2:169–78. PMID:23958792

Rodrigues-Pinto, R.; Richardson, S. M.; Hoyland, J. A.

2013-01-01

6

Nucleus pulposus tissue engineering: a brief review  

Microsoft Academic Search

Symptomatic intervertebral disc degeneration is associated with several spinal diseases, which cause losses of life quality\\u000a and money. Tissue engineering provides a promising approach to recover the functionality of the degenerative intervertebral\\u000a disc. Most studies are directed toward nucleus pulposus (NP) tissue engineering because disc degeneration is believed to originate\\u000a in NP region, and considerable progress has been made in

Xinlin Yang; Xudong Li

2009-01-01

7

A Combinatorial Relative Mass Value Evaluation of Endogenous Bioactive Proteins in Three-Dimensional Cultured Nucleus Pulposus Cells of Herniated Intervertebral Discs: Identification of Potential Target Proteins for Gene Therapeutic Approaches  

PubMed Central

Painful degenerative disc diseases have been targeted by different biological treatment approaches. Nucleus pulposus (NP) cells play a central role in intervertebral disc (IVD) maintenance by orchestrating catabolic, anabolic and inflammatory factors that affect the extracellular matrix. IVD degeneration is associated with imbalances of these factors, resulting in a catabolic inflammatory metabolism. Therefore, accurate knowledge about their quantity and quality with regard to matrix synthesis is vital for a rational gene therapeutic approach. NP cells were isolated from 63 patients operated due to lumbar disc herniation (mean age 56 / range 29 - 84 years). Then, three-dimensional culture with low-glucose was completed in a collagen type I scaffold for four weeks. Subsequently cell proliferation evaluation was performed using 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide and intracellular concentration of 28 endogenously expressed anabolic, catabolic, inflammatory factors and relevant matrix proteins was determined by enzyme-linked immunosorbent assay. Specimen-related grades of degeneration were confirmed by preoperative magnetic resonance imaging. Independent from gender, age and grade of degeneration proliferation rates remained similar in all groups of NP cells. Progressive grades of degeneration, however, showed a significant influence on accumulation of selective groups of factors such as disintegrin and metalloproteinase with thrombospondin motifs 4 and 5, matrix metalloproteinase 3, metalloproteinase inhibitor 1 and 2, interleukin-1? and interleukin-1 receptor. Along with these changes, the key NP matrix proteins aggrecan and collagen II decreased significantly. The concentration of anabolic factors bone morphogenetic proteins 2, 4, 6 and 7, insulin-like growth factor 1, transforming growth factor beta 1 and 3, however, remained below the minimal detectable quantities. These findings indicate that progressive degenerative changes in NP may be problematic with regard to biologic treatment strategies. Hence, gene therapeutic interventions regulating relevant bioactive factors identified in this work might contribute to the development of regenerative treatment approaches for degenerative disc diseases. PMID:24278441

Mern, Demissew S.; Fontana, Johann; Beierfuß, Anja; Thomé, Claudius; Hegewald, Aldemar A.

2013-01-01

8

An injectable cross-linked scaffold for nucleus pulposus regeneration  

Microsoft Academic Search

Incorporation of scaffolds has long been recognized as a critical element in most tissue engineering strategies. However with regard to intervertebral disc tissue engineering, the use of a scaffold containing the principal extracellular matrix components of native disc tissue (i.e. collagen type II, aggrecan and hyaluronan) has not been investigated. In this study the behavior of bovine nucleus pulposus cells

Damien O. Halloran; Sibylle Grad; Martin Stoddart; Peter Dockery; Mauro Alini; Abhay S. Pandit

2008-01-01

9

Numerical analysis of the influence of nucleus pulposus removal on the biomechanical behavior of a lumbar motion segment.  

PubMed

Nucleus replacement was deemed to have therapeutic potential for patients with intervertebral disc herniation. However, whether a patient would benefit from nucleus replacement is technically unclear. This study aimed to investigate the influence of nucleus pulposus (NP) removal on the biomechanical behavior of a lumbar motion segment and to further explore a computational method of biomechanical characteristics of NP removal, which can evaluate the mechanical stability of pulposus replacement. We, respectively, reconstructed three types of models for a mildly herniated disc and three types of models for a severely herniated disc based on a L4-L5 segment finite element model with computed tomography image data from a healthy adult. First, the NP was removed from the herniated disc models, and the biomechanical behavior of NP removal was simulated. Second, the NP cavities were filled with an experimental material (Poisson's ratio = 0.3; elastic modulus = 3 MPa), and the biomechanical behavior of pulposus replacement was simulated. The simulations were carried out under the five loadings of axial compression, flexion, lateral bending, extension, and axial rotation. The changes of the four biomechanical characteristics, i.e. the rotation degree, the maximum stress in the annulus fibrosus (AF), joint facet contact forces, and the maximum disc deformation, were computed for all models. Experimental results showed that the rotation range, the maximum AF stress, and joint facet contact forces increased, and the maximum disc deformation decreased after NP removal, while they changed in the opposite way after the nucleus cavities were filled with the experimental material. PMID:24893132

Huang, Juying; Yan, Huagang; Jian, Fengzeng; Wang, Xingwen; Li, Haiyun

2015-11-01

10

Silk fibroin porous scaffolds for nucleus pulposus tissue engineering.  

PubMed

Intervertebral discs (IVDs) are structurally complex tissue that hold the vertebrae together and provide mobility to spine. The nucleus pulposus (NP) degeneration often results in degenerative IVD disease that is one of the most common causes of back and neck pain. Tissue engineered nucleus pulposus offers an alternative approach to regain the function of the degenerative IVD. The aim of this study is to determine the feasibility of porous silk fibroin (SF) scaffolds fabricated by paraffin-sphere-leaching methods with freeze-drying in the application of nucleus pulposus regeneration. The prepared scaffold possessed high porosity of 92.38±5.12% and pore size of 165.00±8.25?m as well as high pore interconnectivity and appropriate mechanical properties. Rabbit NP cells were seeded and cultured on the SF scaffolds. Scanning electron microscopy, histology, biochemical assays and mechanical tests revealed that the porous scaffolds could provide an appropriate microstructure and environment to support adhesion, proliferation and infiltration of NP cells in vitro as well as the generation of extracellular matrix. The NP cell-scaffold construction could be preliminarily formed after subcutaneously implanted in a nude mice model. In conclusion, The SF porous scaffold offers a potential candidate for tissue engineered NP tissue. PMID:24582244

Zeng, Chao; Yang, Qiang; Zhu, Meifeng; Du, Lilong; Zhang, Jiamin; Ma, Xinlong; Xu, Baoshan; Wang, Lianyong

2014-04-01

11

Development of injectable hydrogels for nucleus pulposus replacement  

NASA Astrophysics Data System (ADS)

Intervertebral disc degeneration has been reported as the underlying cause for 75% of cases of lower back pain and is marked by dehydration of the nucleus pulposus within the intervertebral disc. There have been many implant designs to replace the nucleus pulposus. Some researchers have proposed the replacement of the nucleus pulposus with hydrogel materials. The insertion of devices made from these materials further compromises the annulus of the disc. An ideal nucleus replacement could be injected into the disc space and form a solid in vivo. However, injectable replacements using curing elastomers and thermoplastic materials are not ideal because of the potentially harmful exothermic heat evolved from their reactions and the toxicity of the reactants used. We propose a hydrogel system that can be injected as a liquid at 25°C and solidified to yield a hydrogel within the intervertebral disc at 37°C. In aqueous solutions, these polymers have Lower Critical Solution Temperatures (LCST) between 25-37°C, making them unique candidate materials for this application. Poly(N-isopropylacrylamide) (PNIPAAm) is the most widely studied LCST polymer due to its drastic transition near body temperature. However, by itself, pure PNIPAAm forms a hydrogel that has low water content and can readily undergo plastic deformation. To increase the water content and impart elasticity to PNIPAAm hydrogels, grafted and branched hydrogel systems were created that incorporated the thermogelling PNIPAAm and hydrophilic poly(ethylene glycol) (PEG). In this research, the effects of polymer composition and monomer to initiator ratio, which controls polymer MW, on the in vitro swelling properties (mass, chemical, and compressive mechanical stability) of hydrogels formed from aqueous solutions of these polymers were evaluated. Immersion studies were also conducted in solutions to simulate the osmotic environment of the nucleus pulposus. The effects of repeated compression and unloading cycles on the water content and dimensional recovery of hydrogels made from three candidate polymer formulations were also determined. Unlike PNIPAAm and PEG grafted PNIPAAm hydrogels, PEG branched hydrogels have covalently linked networks. Addition of 7 mol% PEG branches to PNIPAAm resulted in a hydrogel with a higher water content and better elastic recovery than hydrogels made from pure PNIPAAm. PEG branched PNIPAAm hydrogels were shown to have mass, chemical, and compressive mechanical stability in vitro. Furthermore, these hydrogels showed superior dimensional recovery after compressive cycling than pure PNIPAAm and PEG grafted PNIPAAm hydrogels. The 7 mol% PEG branched PNIPAAm hydrogels have suitable swelling and mechanical properties to potentially serve as a nucleus pulposus replacement.

Thomas, Jonathan D.

12

Physical analysis of collagen-GAG composite scaffolds for nucleus pulposus tissue regeneration .  

E-print Network

??In this study biomaterial scaffolds for regeneration of nucleus pulposus were developed by freeze drying slurries with different proportions of collagen II (CII), chondroitin-6-sulfate (CS),… (more)

Simson, Jacob A

2008-01-01

13

Physical analysis of collagen-GAG composite scaffolds for nucleus pulposus tissue regeneration  

E-print Network

In this study biomaterial scaffolds for regeneration of nucleus pulposus were developed by freeze drying slurries with different proportions of collagen II (CII), chondroitin-6-sulfate (CS), and hyaluronic acid (HA). The ...

Simson, Jacob A

2008-01-01

14

Differentiation of mesenchymal stem cells into nucleus pulposus cells in vitro  

Microsoft Academic Search

Summary  To find a new source of seed cells for constructing tissue-engineered intervertebral disc, nucleus pulposus (NP) cells and\\u000a mesenchymal stem cells (MSCs) were isolated from New Zealand white rabbits. The nucleus pulposus cells population was fluorescence-laelled\\u000a and co-cultured with MSCs with or without direct contact. Morphological changes were observed every 12 h. Semi-quantitative\\u000a reverse transcriptase-polymerase chain reaction was performed to

Fenghua Tao; Feng Li; Guanghui Li; Feng Pan

2008-01-01

15

Atelocollagen for culture of human nucleus pulposus cells forming nucleus pulposus-like tissue in vitro: Influence on the proliferation and proteoglycan production of HNPSV-1 cells  

Microsoft Academic Search

Nucleus pulposus (NP) is responsible for maintaining function and structure of the disc. Scaffolds to culture disc cells three-dimensionally are emphasized in recent reports on development of a new method for treating disc degeneration using cell transplantation and tissue engineering. Among artificial scaffolds and cell carrying materials, Atelocollagen is a collagen gel that has an advantage in safety issues over

Daisuke Sakai; Joji Mochida; Toru Iwashina; Takuya Watanabe; Kaori Suyama; Kiyoshi Ando; Tomomitsu Hotta

2006-01-01

16

Injectable Laminin-Functionalized Hydrogel for Nucleus Pulposus Regeneration  

PubMed Central

Cell delivery to the pathological intervertebral disc (IVD) has significant therapeutic potential for enhancing IVD regeneration. The development of injectable biomaterials that retain delivered cells, promote cell survival, and maintain or promote an NP cell phenotype in vivo remains a significant challenge. Previous studies have demonstrated NP cell – laminin interactions in the nucleus pulposus (NP) region of the IVD that promote cell attachment and biosynthesis. These findings suggest that incorporating laminin ligands into carriers for cell delivery may be beneficial for promoting NP cell survival and phenotype. Here, an injectable, laminin-111 functionalized poly(ethylene glycol) (PEG-LM111) hydrogel was developed as a biomaterial carrier for cell delivery to the IVD. We evaluated the mechanical properties of the PEG-LM111 hydrogel, and its ability to retain delivered cells in the IVD space. Gelation occurred in approximately 20 minutes without an initiator, with dynamic shear moduli in the range of 0.9 – 1.4 kPa. Primary NP cell retention in cultured IVD explants was significantly higher over 14 days when cells were delivered within a PEG-LM111 carrier, as compared to cells in liquid suspension. Together, these results suggest this injectable laminin-functionalized biomaterial may be an easy to use carrier for delivering cells to the IVD. PMID:23849345

Francisco, Aubrey T.; Mancino, Robert J.; Bowles, Robby D.; Brunger, Jonathan M.; Tainter, David M.; Chen, Yi-Te; Richardson, William J; Guilak, Farshid; Setton, Lori A.

2013-01-01

17

Advanced glycation end products in degenerative nucleus pulposus with diabetes.  

PubMed

Diabetes mellitus (DM) has been clinically proved as a risk factor of disc degeneration, and the accumulation of advanced glycation end products (AGEs) is known to be potentially involved in diabetes. The purpose of this study is to investigate the effect of AGEs in the degeneration process of diabetic nucleus pulposus (NP) in rats and humans. Diabetic NP cells from rat coccygeal discs were treated with different concentrations of AGEs (0, 50, and 100?µg/ml) for 3 days, and mRNA expressions of MMP-2 and RAGE were measured by real-time RT-PCR. In addition, conditioned medium from NP cells was used to analyze protein expression of MMP-2 activity and ERK by gelatin zymography and Western blot. These experiments were repeated using human intervertebral disc samples. The immunohistochemical expression of AGEs was significantly increased in diabetic discs. In response to AGEs, an increase of MMP-2, RAGE, and ERK at both mRNA and protein expression levels was observed in diabetic NP cells. The findings suggest that AGEs and DM are associated with disc degeneration in both species. Hyperglycemia in diabetes enhances the accumulation of AGEs in the NP and triggers disc degeneration. PMID:24151186

Tsai, Tsung-Ting; Ho, Natalie Yi-Ju; Lin, Ying-Ting; Lai, Po-Liang; Fu, Tsai-Sheng; Niu, Chi-Chien; Chen, Lih-Huei; Chen, Wen-Jer; Pang, Jong-Hwei S

2014-02-01

18

TGF? Controls CCN3 Expression in Nucleus Pulposus Cells of the Intervertebral Disc  

PubMed Central

Objective To investigate TGF? regulation of CCN3 expression in cells of the nucleus pulposus. Methods Real Time RT-PCR and Western blot analysis was used to measure CCN3 expression in the nucleus pulposus. Transfections were used to measure the effect of Smad3, MAPKs and AP1 on TGF? mediated CCN3 promoter activity. Lentiviral knock down of Smad3 was performed to asses the role of Smad3 in CCN3 expression. Results CCN3 was expressed in embryonic and adult intervertebral discs. TGF? decreased CCN3 expression and suppressed its promoter activity in nucleus pulposus cells. DN-Smad3, Smad3-siRNA or DN-AP1 had little effect on TGF? suppression of CCN3 promoter activity. However, p38 and ERK inhibitors blocked suppression of CCN3 by TGF?, suggesting involvement of these signaling pathways in the regulation. Interestingly, overexpression of Smad3, in absence of TGF? increased CCN3 promoter activity. We validated the role of Smad3 in controlling CCN3 expression in Smad3 null mice and in nucleus pulposus cells transduced with lentiviral shSmad3. In terms of function, treatment with rCCN3 showed a dose dependent decrease in proliferation of nucleus pulposus cells. Moreover, CCN3 treated cells shows a decrease in aggrecan, versican, CCN2 as well as collagen type I expression. Conclusion The opposing effect of TGF? on CCN2 and CCN3 expression and suppression of CCN2 by CCN3 in nucleus pulposus cells furthers the paradigm that these CCN proteins form an interacting triad, possibly important in maintaining extracellular matrix homeostasis and cell number. PMID:21618206

Tran, Cassie M.; Smith, Harvey E.; Symes, Aviva; Rittié, Laure; Perbal, Bernard; Shapiro, Irving M.; Risbud, Makarand V.

2011-01-01

19

In vitro measurement of nucleus pulposus swelling pressure: A new technique for studies of spinal adaptation to gravity  

NASA Technical Reports Server (NTRS)

Swelling of the intervertebral disc nucleus pulposus is altered by posture and gravity. We have designed and tested a new osmometer for in vitro determination of nucleus pulposus swelling pressure. The functional principle of the osmometer involves compressing a sample of nucleus pulposus with nitrogen gas until saline pressure gradients across a 0.45 microns Millipore filter are eliminated. Swelling pressure of both pooled dog and pooled pig lumbar disc nucleus pulposus were measured on the new osmometer and compared to swelling pressures determined using the equilibrium dialysis technique. The osmometer measured swelling pressures comparable to those obtained by the dialysis technique. This osmometer provides a rapid, direct, and accurate measurement of swelling pressure of the nucleus pulposus.

Hargens, A. R.; Glover, M. G.; Mahmood, M. M.; Gott, S.; Garfin, S. R.; Ballard, R.; Murthy, G.; Brown, M. D.

1992-01-01

20

Identification of transglutaminase substrates from porcine nucleus pulposus as potential amplifiers in cross-linking cell scaffolds.  

PubMed

Nucleus pulposus from the porcine intervertebral disc was separated chromatographically to discover substrates of microbial transglutaminase. Highly purified proteins were prepared, among them type II collagen, the major protein of the nucleus pulposus. Determination of substrates was performed by transglutaminase-mediated incorporation of biotinylated probes displaying several glutamine and lysine donor proteins. Type II collagen was only labeled if smaller nucleus pulposus proteins were present. One of the modulating proteins was serotransferrin, a lysine donor substrate of bacterial transglutaminase. An additional substrate was the carboxy-terminal propeptide of type II collagen, chondrocalcin. Chondrocalcin, a regulator of type II collagen fibrillogenesis, occurs abundantly in juvenile cartilage and nucleus pulposus. Accordingly, the protein may be regarded as an excellent additive for the preparation of injectable stem cells in nucleus pulposus-like matrices cross-linked by microbial transglutaminase. PMID:23495872

Gebauer, Elke; Goßla, Elke; Kwas, Carolin; Salzig, Denise; Schmiermund, Alexandra; Czermak, Peter; Fuchsbauer, Hans-Lothar

2013-05-13

21

Inflammation Induces Irreversible Biophysical Changes in Isolated Nucleus Pulposus Cells  

PubMed Central

Intervertebral disc degeneration is accompanied by elevated levels of inflammatory cytokines that have been implicated in disease etiology and matrix degradation. While the effects of inflammatory stimulation on disc cell metabolism have been well-studied, their effects on cell biophysical properties have not been investigated. The hypothesis of this study is that inflammatory stimulation alters the biomechanical properties of isolated disc cells and volume responses to step osmotic loading. Cells from the nucleus pulposus (NP) of bovine discs were isolated and treated with either lipopolysaccharide (LPS), an inflammatory ligand, or with the recombinant cytokine TNF-? for 24 hours. We measured cellular volume regulation responses to osmotic loading either immediately after stimulation or after a 1 week recovery period from the inflammatory stimuli. Cells from each group were tested under step osmotic loading and the transient volume-response was captured via time-lapse microscopy. Volume-responses were analyzed using mixture theory framework to investigate two biomechanical properties of the cell, the intracellular water content and the hydraulic permeability. Intracellular water content did not vary between treatment groups, but hydraulic permeability increased significantly with inflammatory treatment. In the 1 week recovery group, hydraulic permeability remained elevated relative to the untreated recovery control. Cell radius was also significantly increased both after 24 hours of treatment and after 1 week recovery. A significant linear correlation was observed between hydraulic permeability and cell radius in untreated cells at 24 hours and at 1-week recovery, though not in the inflammatory stimulated groups at either time point. This loss of correlation between cell size and hydraulic permeability suggests that regulation of volume change is disrupted irreversibly due to inflammatory stimulation. Inflammatory treated cells exhibited altered F-actin cytoskeleton expression relative to untreated cells. We also found a significant decrease in the expression of aquaporin-1, the predominant water channel in disc NP cells, with inflammatory stimulation. To our knowledge, this is the first study providing evidence that inflammatory stimulation directly alters the mechanobiology of NP cells. The cellular biophysical changes observed in this study are coincident with documented changes in the extracellular matrix induced by inflammation, and may be important in disease etiology. PMID:24936787

Maidhof, Robert; Jacobsen, Timothy; Papatheodorou, Angelos; Chahine, Nadeen O.

2014-01-01

22

In situ label-free cell viability assessment of nucleus pulposus tissue.  

PubMed

Regenerative medicine approaches aiming at treating degenerating intervertebral discs, a major cause of back pain, are increasingly tested in ex-vivo disc explant models mimicking in-vivo conditions. For assessing the efficacy of regenerative therapies, cell viability is commonly measured requiring specific labels to stain cells. Here, we demonstrate and evaluate how cellular auto-fluorescence can be utilized to non-invasively assess viability in disc tissue in-situ using label-free two-photon microscopy. Live and dead bovine disc cells (0% and 100% cell viability) from the nucleus pulposus were seeded into collagen gels and auto-fluorescence was characterized. Subsequently, nucleus pulposus explants were cultured for 6 days in media with different glucose supplementation (0, 0.25, 0.5, and 1?g/L) to induce different degrees of cell death. Then, samples were split and viability was assessed using label-free two-photon microscopy and conventional staining. Results show that live and dead nucleus pulposus cells systematically emit auto-fluorescent light with distinct characteristics. Cell viability values obtained with label-free microscopy did not significantly differ from those acquired with staining. In summary, monitoring auto-fluorescence facilitates accurate cell viability assessment in nucleus tissue requiring no additional dyes. Thus, this technique may be suitable for pre-clinical testing of regenerative therapies in nucleus pulposus cultures. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:545-550, 2014. PMID:24391094

Dittmar, Roman; van Dijk, Bart G M; van Zandvoort, Marc A M J; Ito, Keita

2014-04-01

23

Current Developments in Tissue Engineering of Nucleus Pulposus for the Treatment of Intervertebral Disc Degeneration  

Microsoft Academic Search

The main cause for back pain is considered to be the degenerative changes in the intervertebral disc (IVD). Some evidence indicates that IVD degeneration originates from the nucleus pulposus (NP). The IVD does not possess self repair capacity. Current treatment options range from pain management to invasive procedures. The science of disc cell transplantation is still in its infancy. Advancement

Immanuel M. Sebastine; David J. Williams

2007-01-01

24

Formation of a nucleus pulposus-cartilage endplate construct in vitro  

Microsoft Academic Search

Intervertebral disc (IVD) degeneration is a common problem and treatment options for persistent symptomatic disease are limited. Tissue engineering is being explored for its ability to reconstitute the functional components of the IVD. The purpose of this study was to determine whether it was possible to form in vitro a triphasic construct consisting of nucleus pulposus (NP), cartilage endplate (CEP),

Darla J. Hamilton; Cheryle A. Séguin; Jian Wang; Robert M. Pilliar; Rita A. Kandel

2006-01-01

25

Tissue-Engineered Composites of Anulus Fibrosus and Nucleus Pulposus for Intervertebral Disc Replacement  

Microsoft Academic Search

Study Design. By the technique of tissue engineering, composite intervertebral disc implants were fabricated as novel materials for disc replacement, implanted into athy- mic mice, and removed at times up to 12 weeks. Objectives. The goal of this study was to construct com- posite intervertebral disc structures consisting of anulus fi- brosus cells and nucleus pulposus cells seeded on polygly-

Hirokazu Mizuno; Amit K. Roy; Charles A. Vacanti; Koji Kojima; Minoru Ueda; Lawrence J. Bonassar

2004-01-01

26

Rheological Characterization of Hyaluronic Acid Derivatives as Injectable Materials Toward Nucleus Pulposus Regeneration  

Microsoft Academic Search

Nucleus pulposus (NP) is the soft center of the intervertebral disc (IVD), able to resist compressive loads, while the annulus fibrosus withstands tension and gives mechanical strength.NP function may be altered as consequence of several pathologies or injury and when a damaged IVD does not properly play its role. In the past years, a great effort has been devoted to

Antonio Gloria; Assunta Borzacchiello; Filippo Causa; Luigi Ambrosio

2012-01-01

27

Differentiation of mesenchymal stem cells towards a nucleus pulposus-like phenotype utilizing simulated microgravity In vitro  

Microsoft Academic Search

Summary  Mesenchymal stem cells (MSCs) were induced into a nucleus pulposus-like phenotype utilizing simulated microgravity in vitro in order to establish a new cell-based tissue engineering treatment for intervertebral disc degeneration. For induction of\\u000a a nucleus pulposus-like phenotype, MSCs were cultured in simulated microgravity in a chemically defined medium supplemented\\u000a with 0 (experimental group) and 10 ng\\/mL (positive control group) of

Wei Luo; Wei Xiong; Min Qiu; Yongwei Lv; Yong Li; Feng Li

2011-01-01

28

Notochordal cell conditioned medium stimulates mesenchymal stem cell differentiation toward a young nucleus pulposus phenotype  

Microsoft Academic Search

Introduction  Mesenchymal stem cells (MSCs) offer promise for intervertebral disc (IVD) repair and regeneration because they are easily\\u000a isolated and expanded, and can differentiate into several mesenchymal tissues. Notochordal (NC) cells contribute to IVD development,\\u000a incorporate into the nucleus pulposus (NP), and stimulate mature disc cells. However, there have been no studies investigating\\u000a the effects of NC cells on adult stem

Casey L Korecki; Juan M Taboas; Rocky S Tuan; James C Iatridis

2010-01-01

29

Correlating Material Properties with Tissue Composition in Enzymatically Digested Bovine Annulus Fibrosus and Nucleus Pulposus Tissue  

Microsoft Academic Search

Aging and degeneration of the intervertebral disk are accompanied by decreases in water and proteoglycan contents, and structural\\u000a alterations. The aim of this study was to determine the impact of compositional changes on the material properties of intervertebral\\u000a disk tissues. Confined compression stress-relaxation experiments were applied to bovine caudal annulus fibrosus and nucleus\\u000a pulposus tissue specimens that were separated into

Delphine S. Perie; Jeff J. Maclean; Julia P. Owen; James C. Iatridis

2006-01-01

30

Fabrication of a Layered Microstructured Polymeric Microspheres as a Cell Carrier for Nucleus Pulposus Regeneration  

Microsoft Academic Search

This study aimed to investigate the feasibility of nanostructured 3D poly(lactide-co-glycolide) (PLGA) constructs, which are loaded with dexamethasone (DEX) and growth factor embedded hepaiin\\/poly(L-lysine) nanoparticles by a layer-by-layer system, to serve as an effective scaffold for nucleus pulposus (NP) tissue engineering. Our results demonstrated that the microsphere constructs were capable of simultaneously releasing basic fibroblast growth factor and DEX with

Chengzhen Liang; Hao Li; Chan Li; Zhiru Yang; Xiaopeng Zhou; Yiqing Tao; Yuxiang Xiao; Fangcai Li; Qixin Chen

2012-01-01

31

Effects of adenoviral vector expressing hIGF-1 on apoptosis in nucleus pulposus cells in vitro.  

PubMed

The excessive apoptosis of cells of the nucleus pulposus may plays an important role in intervertebral disc (IVD) degeneration. It has been shown that the pro-inflammatory cytokine tumour necrosis factor (TNF)-? can induce disc cell apoptosis. Insulin-like growth factor (IGF)-1 can promote nucleus pulposus cell proliferation; however, whether or not IGF-1 inhibits TNF-?-induced apoptosis in the nucleus pulposus has not yet been elucidated. In this study, our objective was to create a potentially therapeutic viral vector, which could be used to achieve the enforced expression of IGF-1 in rabbit nucleus pulposus cells. Furthermore, we investigated the ability of IGF-1 to reverse TNF-?-induced apoptosis in cells of the nucleus pulposus. Isolated nucleus pulposus cells were cultured to a confluent monolayer, digested with collagenase ? and purified using trypsin and differential adhesion methods. Nucleus pulposus cells were positively identified using type ? collagen immunohistochemistry. Following transfection with adenoviral vectors engineered to overexpress recombinant human IGF-1 (Ad-hIGF-1) or TNF-?, the cells were observed under a light microscope. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL) and flow cytometry (FCM) were used to assess the rate of apoptosis. The Ad-hIGF-1 viral vector was effectively transduced into the nucleus pulposus cells and increased IGF-1 expression as confirmed by RT-PCR and western blot analysis. In the TNF-?-treated group, a large number of apoptotic cells was observed that exhibited morphological changes associated with this form of cell death. Minimal apoptosis was observed in the Ad-hIGF-1-treated group and the control group showed no obvious signs of apoptosis. TUNEL assay revealed that the rate of apoptosis in the Ad-hIGF-1 group was significantly reduced compared with the TNF-?-treated group (P<0.01). This result was confirmed using FCM. The rate of apoptosis was also significantly increased in the TNF-?-exposed cells compared with the control group (P<0.01). Our findings strongly suggest that the adenoviral vector expressing hIGF-1 can successfully infect nucleus pulposus cells in vitro and effectively enhance the expression of IGF-1. In addition, IGF-1 reversed the TNF-? -induced apoptosis of nucleus pulposus cells. Thus, Ad-hIGF-1 may be useful in the development of clinical interventions for disc degeneration. PMID:24337543

Zhang, Chang-Chun; Cui, Guo-Peng; Hu, Jian-Guo; Xiao, Yu-Zhou; Zhou, Xin-She; Shao, Chen; Lin, Qinghua; Zhou, Jian-Sheng

2014-02-01

32

Functional compressive mechanics of a PVA/PVP nucleus pulposus replacement.  

PubMed

Emerging techniques as an alternative to the current treatments of lower back pain include nucleus replacement by an artificial material, which aims to relieve pain and restore the normal spinal motion. The compressive mechanical behavior of the PVA/PVP hydrogel nucleus implant was assessed in the present study. PVA/PVP hydrogels were made with various PVP concentrations. The hydrogels were loaded statically under unconfined and confined conditions. Hydrogels were tested dynamically up to 10 million cycles for a compression fatigue. Also, hydrogel nucleus implants with a line-to-line fit, were implanted in the human cadaveric intervertebral discs (IVD) to determine the compressional behavior of the implanted discs. Hydrogel samples exhibited typical non-linear response under both unconfined and confined compressions. Properties of the confinement ring dictated the observed response. Hydrogel moduli and polymer content were not different pre- and post-fatigues. Slight geometrical changes (mostly recoverable) were observed post-fatigue. In cadavers, hydrogels restored the compressive stiffness of the denucleated disc when compared with equivalent condition of the IVD. The results of this study demonstrate that PVA/PVP hydrogels may be viable as nucleus pulposus implants. Further studies under complex loading conditions are warranted to better assess its potential as a replacement to the degenerated nucleus pulposus. PMID:16115678

Joshi, Abhijeet; Fussell, Garland; Thomas, Jonathan; Hsuan, Andrew; Lowman, Anthony; Karduna, Andrew; Vresilovic, Ed; Marcolongo, Michele

2006-01-01

33

Utilization of stem cells in alginate for nucleus pulposus tissue engineering.  

PubMed

In a general view of anatomy, intervertebral disc is composed of three parts: annulus fibrosus (AF), nucleus pulposus (NP), and cartilage endplate (CEP). Recently, several types of stem cells were successfully isolated from these corresponding regions, but up to now, no research was performed about which kind of stem cells is the most efficient candidate for NP tissue engineering or for stem cell-based disc regeneration therapy. In this study, we compared the regenerative potentials of the above-mentioned three kinds of disc-derived stem cells with that of the classic bone marrow (BM)-mesenchymal stem cells (MSCs) in a rabbit disc degeneration model. By magnetic resonance imaging (MRI), X-ray, histology, etc. evaluations, we found that cartilage endplate-derived stem cells (CESCs) showed superior capacity compared with the annulus fibrosus-derived stem cells (AFSCs), nucleus pulposus-derived stem cells (NPSCs), and BM-MSCs (p<0.05); additionally, when comparing the CESC group with the normal control group, there existed no statistical difference in X-ray (p>0.05). Those results demonstrated that the CESC-seeded alginate construct performed the most powerful ability for NP regeneration, while AFSCs showed the most inferior potency, NPSCs and BM-MSCs had similar regenerative capacity and located in the middle. All in all, our study showed that CESCs might act as an efficient seed cell source for NP tissue engineering, which paved a new way for the biological solution of disc degeneration diseases. PMID:24102374

Wang, Hai; Zhou, Yue; Huang, Bo; Liu, Lan-Tao; Liu, Ming-Han; Wang, Jian; Li, Chang-Qing; Zhang, Zhen-Feng; Chu, Tong-Wei; Xiong, Cheng-Jie

2014-03-01

34

TNF-? and IL-1? Dependent Induction of CCL3 Expression by Nucleus Pulposus Cells Promotes Macrophage Migration through CCR1  

PubMed Central

Objective To investigate TNF-? and IL-1? regulation of CCL3 expression in nucleus pulposus (NP) cells and in macrophage migration. Methods qRT-PCR and immunohistochemistry were used to measure CCL3 expression in NP cells. Transfections were used to determine the role of NF-?B, C/EBP-? and MAPK on cytokine mediated CCL3 promoter activity. Effect of NP-conditioned medium on macrophage migration was measured using a transwell system. Results An increase in CCL3 expression and promoter activity was observed in NP cells after TNF-? or IL-1? treatment. Treatment of cells with NF-?B and MAPK inhibitors abolished the effect of the cytokines on CCL3 expression. The inductive effect of p65 and C/EBP-? on CCL3 promoter was confirmed through gain- and loss-of-function studies. Noteworthy, co-transfection of p50 completely blocked cytokine and p65 dependent induction. In contrast, c-Rel and RelB had little effect on promoter activity. Lentiviral transduction with Sh-p65 and Sh-Ikk? significantly decreased TNF-? dependent increase in CCL3 expression. Analysis of degenerate human NP tissues showed that CCL3, but not CCL4 expression correlated positively with the grade of tissue degeneration. Importantly, treatment of macrophages with conditioned medium of NP cells treated with TNF-? or IL-1? promoted their migration; pretreatment of macrophages with antagonist to CCR1, primary receptor for CCL3 and CCL4, blocked cytokine mediated migration. Conclusions By controlling the activation of MAPK, NF-?B and C/EBP? signaling, TNF-? and IL-1? modulate the expression of CCL3 in NP cells. The CCL3-CCR1 axis may play an important role in promoting macrophage infiltration in degenerate, herniated discs. PMID:23233369

Wang, Jianru; Tian, Ye; Phillips, Kate L.E.; Chiverton, Neil; Haddock, Gail; Bunning, Rowena A.; Cross, Alison K.; Shapiro, Irving M.; LeMaitre, Christine L.; Risbud, Makarand V.

2012-01-01

35

[Diagnostics and therapy of spinal disc herniation].  

PubMed

Degenerative processes in a movement segment of the vertebral column, which can potentially give rise to herniation of elements of the nucleus pulposus, are complex and of variable clinical and radiological dimensions; however the mere assumption that degenerative changes precede disc herniation remains a matter of debate. By definition, spinal disc herniation (SDH) refers to components of the gelatinous nucleus pulposus protruding beyond the dorsal level of the vertebral body margin through tears in the annulus fibrosus. Clinical presentation may include pain, paresis and sensory disturbances. Magnetic resonance imaging (MRI) is considered the gold standard in the diagnosis of SDH. In the majority of patients a conservative approach with physical therapy exercises and adequate analgesic and antiphlogistic medical treatment results in a substantial improvement of symptoms. PMID:25398570

Zimmer, A; Reith, W

2014-11-01

36

Understanding the native nucleus pulposus cell phenotype has important implications for intervertebral disc regeneration strategies.  

PubMed

Low back pain is a leading cause of morbidity in developed societies and is strongly linked to degeneration of the intervertebral disc. The central nucleus pulposus (NP) region is most severely affected during disc degeneration and, consequently, is a focus for novel cell-based regenerative strategies. However, in order to develop such techniques, it is essential to first understand the biology and phenotype of the NP cells intended for repair. Microarray studies have highlighted novel NP markers that will allow a more accurate identification of cells for implantation, and along with other studies, have also revealed the potential importance of a developmental or immature NP cell phenotype in disseminating the optimal cell type for use. Additionally, the degenerative intervertebral disc is a harsh native environment and the effects of this on cells intended for implantation have yet to be fully elucidated; this is crucial for clinical translation of tissue engineered cell-based therapies. PMID:23259807

Ludwinski, Francesca E; Gnanalingham, Kanna; Richardson, Stephen M; Hoyland, Judith A

2013-01-01

37

Chondroprotective supplementation promotes the mechanical properties of injectable scaffold for human nucleus pulposus tissue engineering.  

PubMed

A result of intervertebral disc (IVD) degeneration, the nucleus pulposus (NP) is no longer able to withstand applied load leading to pain and disability. The objective of this study is to fabricate a tissue-engineered injectable scaffold with chondroprotective supplementation in vitro to improve the mechanical properties of a degenerative NP. Tissue-engineered scaffolds were fabricated using different concentrations of alginate and calcium chloride and mechanically evaluated. Fabrication conditions were based on structural and mechanical resemblance to the native NP. Chondroprotective supplementation, glucosamine (GCSN) and chondroitin sulfate (CS), were added to scaffolds at concentrations of 0:0µg/mL (0:0-S), 125:100µg/mL (125:100-S), 250:200µg/mL (250:200-S), and 500:400µg/mL (500:400-S), GCSN and CS, respectively. Scaffolds were used to fabricate tissue-engineered constructs through encapsulation of human nucleus pulposus cells (HNPCs). The tissue-engineered constructs were collected at days 1, 14, and 28 for biochemical and biomechanical evaluations. Confocal microscopy showed HNPC viability and rounded morphology over the 28 day period. MTT analysis resulted in significant increases in cell proliferation for each group. Collagen type II ELISA quantification and compressive aggregate moduli (HA) showed increasing trends for both 250:200-S and the 500:400-S groups on Day 28 with significantly greater HA compared to 0:0-S group. Glycosaminoglycan and water content decreased for all groups. Results indicate the increased mechanical properties of the 250:200-S and the 500:400-S was due to production of a functional matrix. This study demonstrated potential for a chondroprotective supplemented injectable scaffold to restore biomechanical function of a degenerative disc through the production of a mechanically functional matrix. PMID:24055794

Foss, Berit L; Maxwell, Thomas W; Deng, Ying

2014-01-01

38

Reduced nucleus pulposus glycosaminoglycan content alters intervertebral disc dynamic viscoelastic mechanics.  

PubMed

The intervertebral disc functions over a range of dynamic loading regimes including axial loads applied across a spectrum of frequencies at varying compressive loads. Biochemical changes occurring in early degeneration, including reduced nucleus pulposus glycosaminoglycan content, may alter disc mechanical behavior and thus may contribute to the progression of degeneration. The objective of this study was to determine disc dynamic viscoelastic properties under several equilibrium loads and loading frequencies, and further, to determine how reduced nucleus glycosaminoglycan content alters dynamic mechanics. We hypothesized that (1) dynamic stiffness would be elevated with increasing equilibrium load and increasing frequency, (2) the disc would behave more elastically at higher frequencies, and finally, (3) dynamic stiffness would be reduced at low equilibrium loads under all frequencies due to nucleus glycosaminoglycan loss. We mechanically tested control and chondroitinase ABC injected rat lumbar motion segments at several equilibrium loads using oscillatory loading at frequencies ranging from 0.05 to 5Hz. The rat lumbar disc behaved non-linearly with higher dynamic stiffness at elevated compressive loads irrespective of frequency. Phase angle was not affected by equilibrium load, although it decreased as frequency was increased. Reduced glycosaminoglycan decreased dynamic stiffness at low loads but not at high equilibrium loads and led to increased phase angle at all loads and frequencies. The findings of this study demonstrate the effect of equilibrium load and loading frequencies on dynamic disc mechanics and indicate possible mechanical mechanisms through which disc degeneration can progress. PMID:19539936

Boxberger, John I; Orlansky, Amy S; Sen, Sounok; Elliott, Dawn M

2009-08-25

39

Application of nucleus pulposus to L5 dorsal root ganglion in rats enhances nociceptive dorsal horn neuronal windup.  

PubMed

Herniation of the nucleus pulposus (NP) from lumbar intervertebral discs commonly results in radiculopathic pain possibly through a neuroinflammatory response. NP sensitizes dorsal horn neuronal responses, but it is unknown whether this reflects a central or peripheral sensitization. To study central sensitization, we tested if NP enhances windup--the progressive increase in the response of a nociceptive spinal neuron to repeated electrical C-fiber stimulation--a phenomenon that may partly account for temporal summation of pain. Single-unit recordings were made from wide dynamic range (WDR; n = 36) or nociceptive-specific (NS; n = 8) L5 dorsal horn neurons in 44 isoflurane-anesthetized rats. Subcutaneous electrodes delivered electrical stimuli (20 pulses, 3 times the C-fiber threshold, 0.5 ms) to the receptive field on the hindpaw. Autologous NP was harvested from a tail disc and placed onto the L5 dorsal root ganglion after recording of baseline responses (n = 22). Controls had saline applied similarly (n = 22). Electrical stimulus trains (0.1, 0.3, and 1 Hz; 5-min interstimulus interval) were repeated every 30 min for 3-6 h after each treatment. The total number of evoked spikes (summed across all 20 stimuli) to 0.1 Hz was enhanced 3 h after NP, mainly in the after-discharge (AD) period (latency > 400 ms). Total responses to 0.3 and 1.0 Hz were also enhanced at > or = 60 min after NP in both the C-fiber (100- to 400-ms latency) and AD periods, whereas the absolute windup (C-fiber + AD - 20 times the initial response) increased at > or = 90 min after treatment. In saline controls, windup was not enhanced at any time after treatment for any stimulus frequency, although there was a trend toward enhancement at 0.3 Hz. These results are consistent with NP-induced central sensitization. Mechanical responses were not significantly enhanced after saline or NP treatment. We speculate that inflammatory agents released from (or recruited by) NP affect the dorsal root ganglion (and/or are transported to cord) to enhance primary afferent excitation of nociceptive dorsal horn neurons. PMID:15744012

Cuellar, J M; Montesano, P X; Antognini, J F; Carstens, E

2005-07-01

40

Co-culture of Adult Mesenchymal Stem Cells and Nucleus Pulposus Cells in Bilaminar Pellets for Intervertebral Disc Regeneration  

Microsoft Academic Search

BackgroundOur goal is to optimize stem cell-based tissue engineering strategies in the context of the intervertebral disc environment. We explored the benefits of co-culturing nucleus pulposus cells (NPC) and adult mesenchymal stem cells (MSC) using a novel spherical bilaminar pellet culture system where one cell type is enclosed in a sphere of the other cell type. Our 3D system provides

Aliza A. Allon; Richard A. Schneider; Jeffrey C. Lotz

2009-01-01

41

Material properties in unconfined compression of human nucleus pulposus, injectable hyaluronic acid-based hydrogels and tissue engineering scaffolds  

Microsoft Academic Search

Surgical treatment for lower back pain related to degenerative disc disease commonly includes discectomy and spinal fusion.\\u000a While surgical intervention may provide short-term pain relief, it results in altered biomechanics of the spine and may lead\\u000a to further degenerative changes in adjacent segments. One non-fusion technique currently being investigated is nucleus pulposus\\u000a (NP) support via either an injectable hydrogel or

Jordan M. Cloyd; Neil R. Malhotra; Lihui Weng; Weiliam Chen; Robert L. Mauck; Dawn M. Elliott

2007-01-01

42

Basement membrane molecule expression attendant to chondrogenesis by nucleus pulposus cells and mesenchymal stem cells.  

PubMed

Bone marrow-derived mesenchymal stem cells (MSCs) represent an autologous cell source for nucleus pulposus (NP) tissue engineering and regeneration. Although studies have demonstrated the ability of MSCs to differentiate to NP-like chondrocytic cells, few have comparatively studied the matrix synthesis and composition of the cartilaginous tissue formed in vitro from both cell types, particularly with respect to the expression of basement membrane (BM) molecules. The objective of this study was to evaluate chondrogenesis and expression of BM molecules, laminin and type IV collagen, in monolayer and in pellet cultures of caprine NP cells and MSCs. Both cell types demonstrated comparable levels of chondrogenesis, indicated by the percentage of chondrocytic cells, and the amounts of glycosaminoglycan and type II collagen. Laminin and type IV collagen were expressed intracellularly by NP cells and MSCs cultured in monolayer. During chondrogenesis in pellet cultures, the deposition of BM molecules in NP and MSC pellets followed an orderly spatiotemporal shift in pattern from a diffuse territorial and interterritorial distribution to a defined pericellular localization, as seen in normal adult NP. These results inform the use of MSCs for NP regeneration and suggest the possible involvement of certain BM molecules in chondrogenesis and cartilage regeneration. PMID:23508654

Toh, Wei Seong; Foldager, Casper Bindzus; Olsen, Bjorn Reino; Spector, Myron

2013-07-01

43

The effect of a cyclooxygenase 2 inhibitor on early degenerated human nucleus pulposus explants.  

PubMed

Study Design?Preclinical in vitro culture of human degenerated nucleus pulposus (NP) tissue. Objective?Cyclooxygenase 2 inhibitors (e.g., celecoxib) inhibit prostaglandin E2 (PGE2) production, and they have been shown to upregulate regeneration of articular cartilage. In this study, we developed an explant culture system for use with human tissue and tested the potential of celecoxib. Methods?NP explants were cultured with or without 1 ?M of celecoxib and were analyzed at days 0 and 7 for biochemical content (water, sulfated glycosaminoglycans, hydroxyproline, and DNA), gene expression (for disk matrix anabolic and catabolic markers), and PGE2 content. Results?Water and biochemical contents as well as gene expression remained close to native values after 1?week of culture. PGE2 levels were not increased in freshly harvested human NP tissue and thus were not reduced in treated tissues. Although no anabolic effects were observed at the dosage and culture duration used, no detrimental effects were observed and some specimens did respond by lowering PGE2. Conclusions?Human degenerated NP explants were successfully cultured in a close to in vivo environment for 1 week. Further research, especially dosage-response studies, is needed to understand the role of PGE2 in low back pain and the potential of celecoxib to treat painful disks. PMID:24494179

van Dijk, Bart; Potier, Esther; Licht, Ruud; Creemers, Laura; Ito, Keita

2014-02-01

44

Characterization and mechanical performance study of silk/PVA cryogels: towards nucleus pulposus tissue engineering.  

PubMed

Poly (vinyl) alcohol (PVA) cryogels are reported in the literature for application in nucleus pulposus (NP) replacement strategies. However, these studies are mainly limited to acellular approaches-in part due to the high hydrophilicity of PVA gels that renders cellular adhesion difficult. Silk is a versatile biomaterial with excellent biocompatibility. We hypothesize that the incorporation of silk with PVA will (i) improve the cell-hosting abilities of PVA cryogels and (ii) allow better tailoring of physical properties of the composite cryogels for an NP tissue engineering purpose. 5% (wt/vol) PVA is blended with 5% silk fibroin (wt/vol) to investigate the effect of silk?:?PVA ratios on the cryogels' physical properties. Results show that the addition of silk results in composite cryogels that are able to swell to more than 10 times its original dry weight and rehydrate to at least 70% of its original wet weight. Adding at least 20% silk significantly improves surface hydrophobicity and is correlated with an improvement in cell-hosting abilities. Cell-seeded cryogels also display an increment in compressive modulus and hoop stress values. In all, adding silk to PVA creates cryogels that can be potentially used as NP replacements. PMID:25329452

Neo, Puay Yong; Shi, Pujiang; Goh, James Cho-Hong; Toh, Siew Lok

2014-12-01

45

Biological performance of cell-encapsulated methacrylated gellan gum-based hydrogels for nucleus pulposus regeneration.  

PubMed

Limitations of current treatments for intervertebral disc (IVD) degeneration have promoted interest in the development of tissue-engineering approaches. Injectable hydrogels loaded with cells can be used as a substitute material for the inner IVD part, the nucleus pulposus (NP), and provide an opportunity for minimally invasive treatment of IVD degeneration. The NP is populated by chondrocyte-like cells; therefore, chondrocytes and mesenchymal stem cells (MSCs), stimulated to differentiate along the chondrogenic lineage, could be used to promote NP regeneration. In this study, the in vitro and in vivo response of human bone marrow-derived MSCs and nasal chondrocytes (NCs) to modified gellan gum-based hydrogels was investigated. Both ionic- (iGG-MA) and photo-crosslinked (phGG-MA) methacrylated gellan gum hydrogels show no cytotoxicity in extraction assays with MSCs and NCs. Furthermore, the materials do not induce pro-inflammatory responses in endothelial cells. Moreover, MSCs and NCs can be encapsulated into the hydrogels and remain viable for at least 2 weeks, although apoptosis is observed in phGG-MA. Importantly, encapsulated MSCs and NCs show signs of in vivo chondrogenesis in a subcutaneous implantation of iGG-MA. Altogether, the data endorse the potential use of modified gellan gum-based hydrogel as a suitable material in NP tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25370800

Tsaryk, Roman; Silva-Correia, Joana; Oliveira, Joaquim Miguel; Unger, Ronald E; Landes, Constantin; Brochhausen, Christoph; Ghanaati, Shahram; Reis, Rui L; Kirkpatrick, C James

2014-11-01

46

Modulating notochordal differentiation of human induced pluripotent stem cells using natural nucleus pulposus tissue matrix.  

PubMed

Human induced pluripotent stem cells (hiPSCs) can differentiate into notochordal cell (NC)-like cells when cultured in the presence of natural porcine nucleus pulposus (NP) tissue matrix. The method promises massive production of high-quality, functional cells to treat degenerative intervertebral discs (IVDs). Based on our previous work, we further examined the effect of cell-NP matrix contact and culture medium on the differentiation, and further assessed the functional differentiation ability of the generated NC-like. The study showed that direct contact between hiPSCs and NP matrix can promote the differentiation yield, whilst both the contact and non-contact cultures can generate functional NC-like cells. The generated NC-like cells are highly homogenous regarding the expression of notochordal marker genes. A culture medium containing a cocktail of growth factors (FGF, EGF, VEGF and IGF-1) also supported the notochordal differentiation in the presence of NP matrix. The NC-like cells showed excellent functional differentiation ability to generate NP-like tissue which was rich in aggrecan and collagen type II; and particularly, the proteoglycan to collagen content ratio was as high as 12.5-17.5 which represents a phenotype close to NP rather than hyaline cartilage. Collectively, the present study confirmed the effectiveness and flexibility of using natural NP tissue matrix to direct notochordal differentiation of hiPSCs, and the potential of using the generated NC-like cells for treating IVD degeneration. PMID:25054208

Liu, Yongxing; Rahaman, Mohamed N; Bal, B Sonny

2014-01-01

47

Modulating Notochordal Differentiation of Human Induced Pluripotent Stem Cells Using Natural Nucleus Pulposus Tissue Matrix  

PubMed Central

Human induced pluripotent stem cells (hiPSCs) can differentiate into notochordal cell (NC)-like cells when cultured in the presence of natural porcine nucleus pulposus (NP) tissue matrix. The method promises massive production of high-quality, functional cells to treat degenerative intervertebral discs (IVDs). Based on our previous work, we further examined the effect of cell-NP matrix contact and culture medium on the differentiation, and further assessed the functional differentiation ability of the generated NC-like. The study showed that direct contact between hiPSCs and NP matrix can promote the differentiation yield, whilst both the contact and non-contact cultures can generate functional NC-like cells. The generated NC-like cells are highly homogenous regarding the expression of notochordal marker genes. A culture medium containing a cocktail of growth factors (FGF, EGF, VEGF and IGF-1) also supported the notochordal differentiation in the presence of NP matrix. The NC-like cells showed excellent functional differentiation ability to generate NP-like tissue which was rich in aggrecan and collagen type II; and particularly, the proteoglycan to collagen content ratio was as high as 12.5–17.5 which represents a phenotype close to NP rather than hyaline cartilage. Collectively, the present study confirmed the effectiveness and flexibility of using natural NP tissue matrix to direct notochordal differentiation of hiPSCs, and the potential of using the generated NC-like cells for treating IVD degeneration. PMID:25054208

Liu, Yongxing; Rahaman, Mohamed N.; Bal, B. Sonny

2014-01-01

48

Augmentation and repair tissue formation of the nucleus pulposus after partial nucleotomy in a rabbit model.  

PubMed

Disc degeneration alters disc height and mechanics of the spinal column and is associated with lower back pain. In preclinical studies gel-like materials or resorbable polymer-based implants are frequently used to rebuild the nucleus pulposus, aiming at tissue regeneration and restoration of tissue function. To compare the outcome of tissue repair, freeze-dried resorbable polyglycolic acid-hyaluronan (PGA/HA) implants without any bioactive components or bioactivated fibrin (fibrin-serum) was used in a degenerated disc disease model in New Zealand white rabbits. Animals with partial nucleotomy only served as controls. The T2-weighted/fat suppression sequence signal intensity in the nuclear region of operated discs as assessed by magnet resonance imaging was reduced in operated compared to healthy discs, indicating loss of water and did not change from week 1 to month 6 after surgery. Quantification of histological and immunohistochemical staining indicated that the implantation of PGA/HA leads to significantly more repair tissue compared to nucleotomy only. Type II collagen content of the repair tissue formed after PGA/HA or fibrin-serum treatment is significantly increased compared to controls with nucleotomy only. The data indicate that intervertebral disc augmentation after nucleotomy has a positive effect on repair tissue formation and type II collagen deposition as shown in the rabbit model. PMID:25287887

Endres, M; Zenclussen, M L; Casalis, P A; Freymann, U; Gil Garcia, S; Krueger, J P; Thomale, U-W; Woiciechowsky, C; Kaps, C

2014-12-01

49

A Study on Dispersion and Rate of Fat Infiltration in the Lumbar Spine of Patients with Herniated Nucleus Polpusus  

PubMed Central

[Purpose] This study investigated the relationship between herniated nucleus pulposus (HNP) and fat infiltration of muscles around the spine by measuring body mass index (BMI) and fat infiltration of the muscles around the spine. [Subjects and Methods] Subjects were 82 people, both men and women they were divided into two groups, a normal group and a patient group who were suffering from serious HNP between L4 and L5. Of the anthropometric measurement, and fat infiltration muscles by measuring the cross-sectional area from the center of the disc to the muscle around the spine and the cross-sectional area of fat infiltration. [Results] Fat infiltration rate of each lumbar layer in the normal group was different L34–L45 and L45–L5S1, but not between L23–L34. Fat infiltration in the muscle between the normal group and patients with HNP was different in the layers and the difference was greatest in the L5–S1 layer. [Conclusion] We performed correlation analysis of BMI and the total fat infiltration rate in each group to find the relationship between obesity and fat infiltration in the lumbar spine. Fat infiltration increased, and normal people or patients with chronic back pain are considered to be exposed to other diseases as fat infiltration in the lumbar spine increases. PMID:24567672

Kong, Bong-jun; Lim, Jong-soo; Kim, Kyung

2014-01-01

50

Regulation of CCN2/CTGF Expression in the Nucleus Pulposus of the Intervertebral Disc: Role of Smad and AP1 Signaling  

PubMed Central

Objective To investigate TGF? regulation of CTGF expression in cells of the nucleus pulposus. Methods Real Time RT-PCR and Western blot analysis was used to measure CTGF expression in the nucleus pulposus. Transfections were used to measure the effect of Smad2/3/7 and AP1on TGF? mediated CTGF promoter activity. Results CTGF expression was lower in the neonatal disc compared with the skeletally mature rat disc. An increase in CTGF expression and promoter activity was observed in nucleus pulposus cells after TGF? treatment. Deletion analysis indicated that promoter constructs lacking smad and AP1 motifs were unresponsive to treatment. Analysis showed that full-length Smad3 and the Smad3-MH2 domain alone increased CTGF activity. Further evidence of Smad3 and AP1 involvement was seen when DN-Smad3, SiRNA-Smad3, smad7 and DN-AP1 suppressed TGF? mediated activation of the CTGF promoter. When either Smad3 or AP1 sites were mutated, CTGF promoter induction by TGF? was suppressed. We also observed a decrease in expression of CTGF in discs of Smad3 null mice compared to the wild type. Analysis of human nucleus pulposus indicated a trend of increasing CTGF and TGF? expression in the degenerate state. Conclusion TGF?, through Smad3 and AP1, serves as a positive regulator of CTGF expression in the nucleus pulposus. We propose that CTGF is a part of the limited reparative response of the degenerate disc. PMID:20222112

Tran, Cassie M.; Markova, Dessislava; Smith, Harvey E.; Susarla, Bala; Ponnappan, Ravi Kumar; Anderson, D Greg; Symes, Aviva; Shapiro, Irving M.; Risbud, Makarand V.

2011-01-01

51

Protective effect of carboxymethylated chitosan on hydrogen peroxide-induced apoptosis in nucleus pulposus cells.  

PubMed

Although the etiology of intervertebral disc degeneration is poorly understood, one approach to prevent this process may be to inhibit apoptosis. In the current study, the anti?apoptotic effects of carboxymethylated chitosan (CMCS) in nucleus pulposus (NP) cells were investigated with the aim to enhance disc cell survival. Rat NP cells were isolated and cultured in vitro, and hydrogen peroxide (H2O2) was used to build the NP cell apoptosis model. Cell viability was assessed with a cell counting kit?8 assay. The ratio of apoptotic cells was surveyed by annexin V?fluorescein isothiocyanate (FITC) and propidium iodide (PI) double staining analysis, and the morphology was observed by Hoechst 33342 staining. The mitochondrial membrane potential of NP cells was evaluated by rhodamine 123 fluorescence staining. Reverse transcription (RT)?quantitative polymerase chain reaction (qPCR) was performed to measure mRNA levels of inducible nitric oxide synthase (iNOS), caspase?3, B?cell lymphoma (Bcl)?2, type II collagen and aggrecan. Western blot analysis was performed to detect protein levels of iNOS and Bcl?2. The annexin V?FITC/PI and Hoechst 33342 staining results indicated that CMCS was able to prevent NP cells from apoptosis in a dose?dependent manner. Rhodamine 123 staining clarified that CMCS reduced the impairment of the mitochondrial membrane potential in H2O2?treated NP cells. Reduced caspase?3 and increased Bcl?2 activity were detected in CMCS?treated NP cells by RT?qPCR and western blot analysis. CMCS also promoted the proliferation and secretion of type II collagen and aggrecan in H2O2?treated NP cells. CMCS was indicated to be effective in preventing apoptotic cell death in vitro, demonstrating the potential advantages of this therapeutic approach in regulating disc degeneration. PMID:25394560

He, Bin; Tao, Haiying; Liu, Shiqing; Wei, Ailin

2015-03-01

52

Protective effect of carboxymethylated chitosan on hydrogen peroxide-induced apoptosis in nucleus pulposus cells  

PubMed Central

Although the etiology of intervertebral disc degeneration is poorly understood, one approach to prevent this process may be to inhibit apoptosis. In the current study, the anti-apoptotic effects of carboxymethylated chitosan (CMCS) in nucleus pulposus (NP) cells were investigated with the aim to enhance disc cell survival. Rat NP cells were isolated and cultured in vitro, and hydrogen peroxide (H2O2) was used to build the NP cell apoptosis model. Cell viability was assessed with a cell counting kit-8 assay. The ratio of apoptotic cells was surveyed by annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) double staining analysis, and the morphology was observed by Hoechst 33342 staining. The mitochondrial membrane potential of NP cells was evaluated by rhodamine 123 fluorescence staining. Reverse transcription (RT)-quantitative polymerase chain reaction (qPCR) was performed to measure mRNA levels of inducible nitric oxide synthase (iNOS), caspase-3, B-cell lymphoma (Bcl)-2, type II collagen and aggrecan. Western blot analysis was performed to detect protein levels of iNOS and Bcl-2. The annexin V-FITC/PI and Hoechst 33342 staining results indicated that CMCS was able to prevent NP cells from apoptosis in a dose-dependent manner. Rhodamine 123 staining clarified that CMCS reduced the impairment of the mitochondrial membrane potential in H2O2-treated NP cells. Reduced caspase-3 and increased Bcl-2 activity were detected in CMCS-treated NP cells by RT-qPCR and western blot analysis. CMCS also promoted the proliferation and secretion of type II collagen and aggrecan in H2O2-treated NP cells. CMCS was indicated to be effective in preventing apoptotic cell death in vitro, demonstrating the potential advantages of this therapeutic approach in regulating disc degeneration. PMID:25394560

HE, BIN; TAO, HAIYING; LIU, SHIQING; WEI, AILIN

2015-01-01

53

Silk-Fibrin/Hyaluronic Acid Composite Gels for Nucleus Pulposus Tissue Regeneration  

PubMed Central

Scaffold designs are critical for in vitro culture of tissue-engineered cartilage in three-dimensional environments to enhance cellular differentiation for tissue engineering and regenerative medicine. In the present study we demonstrated silk and fibrin/hyaluronic acid (HA) composite gels as scaffolds for nucleus pulposus (NP) cartilage formation, providing both biochemical support for NP outcomes as well as fostering the retention of size of the scaffold during culture due to the combined features of the two proteins. Passage two (P2) human chondrocytes cultured in 10% serum were encapsulated within silk-fibrin/HA gels. Five study groups with fibrin/HA gel culture (F/H) along with varying silk concentrations (2% silk gel only, fibrin/HA gel culture with 1% silk [F/H+1S], 1.5% silk [F/H+1.5S], and 2% silk [F/H+2S]) were cultured in serum-free chondrogenic defined media (CDM) for 4 weeks. Histological examination with alcian blue showed a defined chondrogenic area at 1 week in all groups that widened homogenously until 4 weeks. In particular, chondrogenic differentiation observed in the F/H+1.5S had no reduction in size throughout the culture period. The results of biochemical and molecular biological evaluations supported observations made during histological examination. Mechanical strength measurements showed that the silk mixed gels provided stronger mechanical properties for NP tissue than fibrin/HA composite gels in CDM. This effect could potentially be useful in the study of in vitro NP tissue engineering as well as for clinical implications for NP tissue regeneration. PMID:21736446

Park, Sang-Hyug; Cho, Hongsik; Gil, Eun Seok; Mandal, Biman B.; Min, Byoung-Hyun

2011-01-01

54

Regeneration of nucleus pulposus tissue in an ovine intervertebral disc degeneration model by cell-free resorbable polymer scaffolds.  

PubMed

Degeneration of intervertebral discs (IVDs) occurs frequently and is often associated with lower back pain. Recent treatment options are limited and treat the symptoms rather than regenerate the degenerated disc. Cell-free, freeze-dried resorbable polyglycolic acid (PGA)-hyaluronan implants were used in an ovine IVD degeneration model. The nucleus pulposus of the IVD was partially removed, endoscopically. PGA-hyaluronan implants were immersed in autologous sheep serum and implanted into the disc defect. Animals with nucleotomy only served as controls. The T2-weighted/fat suppression sequence signal intensity index of the operated discs, as assessed by magnetic resonance imaging (MRI), showed that implantation of the PGA-hyaluronan implant improved (p = 0.0066) the MRI signal compared to controls at 6 months after surgery. Histological analysis by haematoxylin and eosin and safranin O staining showed the ingrowth of cells with typical chondrocytic morphology, even cell distribution, and extracellular matrix rich in proteoglycan. Histomorphometric analyses confirmed that the implantation of the PGA-hyaluronan scaffolds improved (p = 0.027) the formation of regenerated tissue after nucleotomy. Disc heights remained stable in discs with nucleotomy only as well as after implantation of the implant. In conclusion, implantation of cell-free polymer-based implants after nucleotomy induces nucleus pulposus tissue regeneration and improves disc water content in the ovine model. PMID:22865642

Woiciechowsky, Christian; Abbushi, Alexander; Zenclussen, Maria L; Casalis, Pablo; Krüger, Jan Philipp; Freymann, Undine; Endres, Michaela; Kaps, Christian

2014-10-01

55

Novel immortal human cell lines reveal subpopulations in the nucleus pulposus  

PubMed Central

Introduction Relatively little is known about cellular subpopulations in the mature nucleus pulposus (NP). Detailed understanding of the ontogenetic, cellular and molecular characteristics of functional intervertebral disc (IVD) cell populations is pivotal to the successful development of cell replacement therapies and IVD regeneration. In this study, we aimed to investigate whether phenotypically distinct clonal cell lines representing different subpopulations in the human NP could be generated using immortalization strategies. Methods Nondegenerate healthy disc material (age range, 8 to 15 years) was obtained as surplus surgical material. Early passage NP monolayer cell cultures were initially characterized using a recently established NP marker set. NP cells were immortalized by simian virus 40 large T antigen (SV40LTag) and human telomerase reverse transcriptase expression. Immortalized cells were clonally expanded and characterized based on collagen type I, collagen type II, ?1 (COL2A1), and SRY-box 9 (SOX9) protein expression profiles, as well as on expression of a subset of established in vivo NP cell lineage markers. Results A total of 54 immortal clones were generated. Profiling of a set of novel NP markers (CD24, CA12, PAX1, PTN, FOXF1 and KRT19 mRNA) in a representative set of subclones substantiated successful immortalization of multiple cellular subpopulations from primary isolates and confirmed their NP origin and/or phenotype. We were able to identify two predominant clonal NP subtypes based on their morphological characteristics and their ability to induce SOX9 and COL2A1 under conventional differentiation conditions. In addition, cluster of differentiation 24 (CD24)–negative NP responder clones formed spheroid structures in various culture systems, suggesting the preservation of a more immature phenotype compared to CD24-positive nonresponder clones. Conclusions Here we report the generation of clonal NP cell lines from nondegenerate human IVD tissue and present a detailed characterization of NP cellular subpopulations. Differential cell surface marker expression and divergent responses to differentiation conditions suggest that the NP subtypes may correspond to distinct maturation stages and represent distinct NP cell subpopulations. Hence, we provide evidence that the immortalization strategy that we applied is capable of detecting cell heterogeneity in the NP. Our cell lines yield novel insights into NP biology and provide promising new tools for studies of IVD development, cell function and disease. PMID:24972717

2014-01-01

56

Normal and degenerated rabbit nucleus pulposus cells in in vitro cultures: A biological comparison.  

PubMed

This study examined the biological characteristics of normal and degenerated rabbit nucleus pulposus (NP) cells in vitro in order to provide seed cells for intervertebral disc (IVD) tissue engineering. A total of 8 adult New Zealand white rabbits underwent annulus puncture to establish models of intervertebral disc degeneration (IDD). Four weeks later, normal and degenerated NP cells were obtained. Cell morphology was observed by light and electron microscopy. Cell viability was measured by MTT assay. Cell cycle and expression of extracellular matrix (ECM)-related genes (aggrecan and type II collagen) were determined by using flow cytometry and RT-PCR respectively. The growth curve of normal NP cells showed that the cells at passage 4 tended to slowly grow on the fifth day of culture. The density of normal NP cells at passages 5 to 7 was significantly less than that of the first-passage cells 2 or 3 days after seeding (P<0.05). The degenerated NP cells at passage 3 showed slow growth at 4th day. After 5 passages, the degenerated NP cells assumed stagnant growth and the growth seemed to stop at passage 7. The MTT assay revealed that for both normal and degenerated NP cells, the absorbance (A) value at passages 4-7 was obviously decreased as compared with that at passage 1 (P<0.05). Cell cycle analysis showed that the proportion of normal NP cells at Gl phase was 65.4%±3.5%, significantly lower than that of degenerated NP cells at the same cell cycle phase with the value being 77.6%±4.8%. The degenerated NP cells were predominantly arrested at G1 phase and failed to enter S phase. The expression of type II collagen and aggrecan was significantly decreased with passaging. It was concluded that normal NP cells possessed good viability and proliferative capacity by the third passage, and they could secrete large amounts of ECM within this period. The normal NP cells may serve as seed cells for IVD tissue engineering. PMID:23592135

He, Bin; Wang, Yu-Huan; Yang, Jian; Peng, Fang-Liang; Li, Feng

2013-04-01

57

Establishment of a promising human nucleus pulposus cell line for intervertebral disc tissue engineering.  

PubMed

Low-back pain caused by intervertebral disc degeneration could be recovered by the regeneration of the nucleus pulposus (NP). This study aimed to establish a chondrogenic recovery model with promising a human NP (hNP) cell line, an immortalized hNP (ihNP), which could be a screening platform to identify regenerative drugs. The ihNP cells were created from primary human NP cells transfected with a retroviral vector-driven HPV16 E6/E7. Growth properties and characteristics of ihNP were evaluated by comparing with parental NP cells. Successful immortalization of ihNP cells stably expressed HPV 16 E6/E7 mRNA. The doubling time of ihNP was shortened to 53.16±2.63?h compared with parental hNP-P1. Cell cycle regulators, including p53, p21, and pRB were downregulated compared to parental hNP-P1. The in vivo neoplastic forming assay also demonstrated that the ihNP was nontumorigenic. After 25 generations of cell cultures, the ihNP cells, yet stably expressed chondrogenic genes, including (SOX9), type II collagen (Col II), aggrecan, decorin, biglycan, and versican. Higher expressions of chondrogenic proteins, including Col II, phosphorylated SOX9 (p-SOX9), and CD44 were also determined. Under the stressful inflammatory conditions induced by lipopolysaccharides (LPS), the regenerative and anti-inflammatory potentials of ihNP in two-dimensional culture with the presence of platelet-rich plasma (PRP) were evaluated by reverse transcriptase polymerase chain reaction. PRP showed significant effects on restoring diminished chondrogenic markers and deleterious inflammatory responses induced by LPS in ihNP. The therapeutic potentials of ihNP in three-dimensional neocartilage model could also be exerted by PRP using histological evaluation and immunological staining. Hence, the established ihNP cells can provide a chondrogenic recovery model as a regenerative drug screening tool for further regenerative drug discovery and development. PMID:23675702

Liu, Ming-Che; Chen, Wei-Hong; Wu, Ling-Chiao; Hsu, Wei-Che; Lo, Wen-Cheng; Yeh, Shauh-Der; Wang, Ming-Fu; Zeng, Rong; Deng, Win-Ping

2014-01-01

58

PKC? Signalling Activates ERK1/2, and Regulates Aggrecan, ADAMTS5, and miR377 Gene Expression in Human Nucleus Pulposus Cells  

PubMed Central

The protein kinase C (PKC) signaling, a major regulator of chondrocytic differentiation, has been also implicated in pathological extracellular matrix remodeling, and here we investigate the mechanism of PKC?-dependent regulation of the chondrocytic phenotype in human nucleus pulposus (NP) cells derived from herniated disks. NP cells from each donor were successfully propagated for 25+ culture passages, with remarkable tolerance to repeated freeze-and-thaw cycles throughout long-term culturing. More specifically, after an initial downregulation of COL2A1, a stable chondrocytic phenotype was attested by the levels of mRNA expression for aggrecan, biglycan, fibromodulin, and lumican, while higher expression of SOX-trio and Patched-1 witnessed further differentiation potential. NP cells in culture also exhibited a stable molecular profile of PKC isoforms: throughout patient samples and passages, mRNAs for PKC ?, ?, ?, ?, ?, ?, and µ were steadily detected, whereas ?, ?, and ? were not. Focusing on the signalling of PKC?, an isoform that may confer protection against degeneration, we found that activation with the PKC?-specific activator small peptide ??RACK led sequentially to a prolonged activation of ERK1/2, increased abundance of the early gene products ATF, CREB1, and Fos with concurrent silencing of transcription for Ki67, and increases in mRNA expression for aggrecan. More importantly, ??RACK induced upregulation of hsa-miR-377 expression, coupled to decreases in ADAMTS5 and cleaved aggrecan. Therefore, PKC? activation in late passage NP cells may represent a molecular basis for aggrecan availability, as part of an PKC?/ERK/CREB/AP-1-dependent transcriptional program that includes upregulation of both chondrogenic genes and microRNAs. Moreover, this pathway should be considered as a target for understanding the molecular mechanism of IVD degeneration and for therapeutic restoration of degenerated disks. PMID:24312401

Pneumaticos, Spiros G.; Tragas, Adamantios A.; Michalopoulos, Ioannis; Mangoura, Dimitra

2013-01-01

59

Recent advances in biological therapies for disc degeneration: tissue engineering of the annulus fibrosus, nucleus pulposus and whole intervertebral discs.  

PubMed

Advanced intervertebral disc (IVD) degeneration, a major cause of back pain in the United States, is treated using invasive surgical intervention which may cause further degeneration is the future. Because of the limitations of traditional solutions, tissue engineering therapies have become increasingly popular. IVDs have two distinct regions, the inner nucleus pulposus (NP) which is jelly-like and rich in glycosaminoglycans (GAGs) and the outer annulus fibrosus (AF) which is organized into highly collagenous lamellae. Tissue engineered scaffolds, as well as whole organ culture systems have been developed. These culture systems may help elucidate the initial causes of disc degeneration. To create an effective tissue engineered therapy, researchers have focused on designing materials that mimic the properties of these two regions to be used independently or in concert. The few in vivo studies show promise in retaining disc height and MRI T2 signal intensity, the gold standard in determining disc health. PMID:23773764

Hudson, Katherine D; Alimi, Marjan; Grunert, Peter; Härtl, Roger; Bonassar, Lawrence J

2013-10-01

60

Biological evaluation of human degenerated nucleus pulposus cells in functionalized self-assembling peptide nanofiber hydrogel scaffold.  

PubMed

Nucleus pulposus (NP) tissue engineering has been proposed as a novel biological treatment for early-stage intervertebral disc degeneration. In this study, a novel functional self-assembling peptide PKP was first designed by linking the short functional motif of bone morphogenetic protein-7 (BMP7) to the C-terminal of RADA16-I, and another new functional self-assembling peptide was obtained by mixing RKP with RADA16-I. Then, the biocompatibilities and bioactivities of RKP and RAD-RKP for human degenerated nucleus pulposus cells (hNPCs) were studied in vitro. Atomic force microscopy and scanning electron microscopy (SEM) confirmed that both RKP and RAD-RKP could self-assemble into three-dimensional (3D) nanofiber hydrogel scaffolds in a culture medium at 37°C. After the hNPCs were cultured in 3D scaffolds, both RKP and RAD-RKP exhibited reliable attachment and extremely low cytotoxicities (<14%), which were verified by SEM and cytotoxity assays, respectively. Our results also showed that the functional-based scaffolds could increase the proliferation and migration of hNPCs after 7 days compared with culture plates and pure RADA16-I. Quantitative real-time polymerase chain reaction demonstrated that the expressions of collagen II ?1, Sox-9, and aggrecan were upregulated, while collagen I ?1 was downregulated by functional-based scaffolds after 28 days. Furthermore, we also confirmed that RAD-RKP exhibited a higher hNPC proliferation, migration, and expression of Sox-9 and aggrecan compared with pure RKP. Therefore, the results of this study indicated that the BMP7 short motif-designed functional self-assembling peptide nanofiber hydrogels could be used as excellent scaffolds in NP tissue engineering, and RAD-RKP might have further potential application in human mild degenerated NP tissue regeneration. PMID:24450796

Tao, Hui; Zhang, Yan; Wang, Chao-Feng; Zhang, Chao; Wang, Xiu-Mei; Wang, De-Li; Bai, Xue-Dong; Wen, Tian-Yong; Xin, Hong-Kui; Wu, Jian-Hong; Liu, Yue; He, Qin; Ruan, Dike

2014-06-01

61

Variations in Gene and Protein Expression in Canine Chondrodystrophic Nucleus Pulposus Cells following Long-Term Three-Dimensional Culture  

PubMed Central

Intervertebral disc (IVD) degeneration greatly affects quality of life. The nucleus pulposus (NP) of chondrodystrophic dog breeds (CDBs) is similar to the human NP, because the cells disappear with age and are replaced by fibrochondrocyte-like cells. However, because IVD develops as early as within the first year of life, we used canines as a model to investigate in vitro the mechanisms underlying IVD degeneration. Specifically, we evaluated the potential of a three-dimensional (3D) culture of healthy NP as an in vitro model system to investigate the mechanisms of IVD degeneration. Agarose hydrogels were populated with healthy NP cells from beagles after performing magnetic resonance imaging, and mRNA expression profiles and pericellular extracellular matrix (ECM) protein distribution were determined. After 25 days of 3D culture, there was a tendency for redifferentiation into the native NP phenotype, and mRNA levels of Col2A1, COMP, and CK18 were not significantly different from those of freshly isolated cells. Our findings suggest that long-term 3D culture promoted chondrodystrophic NP redifferentiation through reconstruction of the pericellular microenvironment. Further, lipopolysaccharide (LPS) induced expression of TNF-?, MMP3, MMP13, VEGF, and PGES mRNA in the 3D cultures, creating a molecular milieu that mimics that of degenerated NP. These results suggest that this in vitro model represents a reliable and cost-effective tool for evaluating new therapies for disc degeneration. PMID:23658803

Iwata, Munetaka; Ochi, Hiroki; Asou, Yoshinori; Haro, Hirotaka; Aikawa, Takeshi; Harada, Yasuji; Nezu, Yoshinori; Yogo, Takuya; Tagawa, Masahiro; Hara, Yasushi

2013-01-01

62

Evaluation of platelet-rich plasma and hydrostatic pressure regarding cell differentiation in nucleus pulposus tissue engineering.  

PubMed

Generation of a biological nucleus pulposus (NP) replacement by tissue engineering appears to be a promising approach for the therapy of early stages of intervertebral disc degeneration. Thereby, autologous mesenchymal stem cells (MSCs) represent an attractive cell source compared to cells of the NP that are already altered in their phenotype due to degenerative processes. This study compares the influence of 3D pellet culture and alginate beads, as well as that of different media compositions, by the addition of human platelet-rich plasma (PRP) or transforming growth factor (TGF-?1 ) in interaction with hydrostatic pressure on chondrogenic differentiation of human MSCs compared to NP cells. We found that gene expression of the chondrogenic markers aggrecan, collagen type 2 and collagen type 1 and Sox9 was considerably lower in cells cultivated with PRP compared to TGF-?1 . Immunohistology confirmed this result at protein level in pellet culture. Additionally, the pellet culture system was found to be more suitable than alginate beads. A positive influence of hydrostatic pressure could only be shown for individual donors. In summary, in comparison to TGF-?1 , human PRP did not induce adequate chondrogenic differentiation for both culture systems and cell types used. The mixture of growth factors in PRP promoted proliferation rather than chondrogenic differentiation. Based on these results, an application of PRP in human NP tissue-engineering approaches cannot be recommended. PMID:22162329

Mietsch, Antje; Neidlinger-Wilke, Cornelia; Schrezenmeier, Hubert; Mauer, Uwe Max; Friemert, Benedikt; Wilke, Hans-Joachim; Ignatius, Anita

2013-03-01

63

Reconstruction of an in vitro niche for the transition from intervertebral disc development to nucleus pulposus regeneration.  

PubMed

The nucleus pulposus (NP) plays a prominent role in both the onset and progression of intervertebral disc degeneration. While autologous repair strategies have demonstrated some success, their in vitro culture system is outdated and insufficient for maintaining optimally functioning cells through the required extensive passaging. Consequently, the final population of cells may be unsuitable for the overwhelming task of repairing tissue in vivo and could result in subpar clinical outcomes. Recent work has identified synovium-derived stem cells (SDSCs) as a potentially important new candidate. This population of precursors can promote matrix regeneration and additionally restore the balance of catabolic and anabolic metabolism of surrounding cells. Another promising application is their ability to produce an extracellular matrix in vitro that can be modified via decellularization to produce a tissue-specific substrate for efficient cell expansion, while retaining chondrogenic potential. When combined with hypoxia, soluble factors, and other environmental regulators, the resultant complex microenvironment will more closely resemble the in vivo niche, which further improves the cell capacity, even after extensive passaging. In this review, the adaptive mechanisms NP cells utilize in vivo are considered for insight into what factors are important for constructing a tissue-specific in vitro niche. Evidence for the use of SDSCs for NP regeneration is also discussed. Many aspects of NP behavior are still unknown, which could lead to future work yielding key information on producing sufficient numbers of a high-quality NP-specific population that is able to regenerate deteriorated NP in vivo. PMID:23259403

Shoukry, Mark; Li, Jingting; Pei, Ming

2013-04-15

64

Enhancing human nucleus pulposus cells for biological treatment approaches of degenerative intervertebral disc diseases: a systematic review.  

PubMed

Intervertebral disc (IVD) degeneration has been described as an aberrant, cell-mediated, age- and genetics-dependent molecular degeneration process, which can be accelerated by nutritional, mechanical and toxic factors. Collective involvement of these factors can result in structural failures, which are often associated with pain. Current treatment approaches are restricted to symptomatic therapies, not addressing options of restoring structural or biological deterioration of the IVD as the underlying problem. Therapeutic potentials of IVD cell transplantation, biomaterials, inhibiting or activating bioactive factors, including gene-therapeutic approaches, have been shown in vitro or in small animal models. Since human degenerative IVD cells display distinctive features with regard to cell biology and regenerative potential, we attempted a systematic review, investigating the in vitro response of human nucleus pulposus cells to different stimuli. Therefore, we conducted an electronic database search on Medline through July 2011 to identify, compare and discuss publications concerning the effects of cell-cell stimulation, bioactive factors, biomaterials and combinations thereof in terms of cell isolation, proliferation, differentiation and matrix protein synthesis. This survey and discussion might serve as a source for designing future biological treatment strategies for the human IVD. Copyright © 2012 John Wiley & Sons, Ltd. PMID:22927290

Mern, Demissew Shenegelegn; Beierfuß, Anja; Thomé, Claudius; Hegewald, Aldemar Andres

2014-12-01

65

In situ forming hydrogels composed of oxidized high molecular weight hyaluronic acid and gelatin for nucleus pulposus regeneration.  

PubMed

Encapsulation of nucleus pulposus (NP) cells within in situ forming hydrogels is a novel biological treatment for early stage intervertebral disc degeneration. The procedure aims to prolong the life of the degenerating discs and to regenerate damaged tissue. In this study we developed an injectable oxidized hyaluronic acid-gelatin-adipic acid dihydrazide (oxi-HAG-ADH) hydrogel. High molecular weight (1900 kDa) hyaluronic acid was crosslinked with various concentrations of gelatin to synthesize the hydrogels and their viscoelastic properties were analyzed. Interactions between the hydrogels, NP cells, and the extracellular matrix (ECM) were also evaluated, as were the effects of the hydrogels on NP cell gene expression. The hydrogels possess several clinical advantages, including sterilizability, low viscosity for injection, and ease of use. The viscoelastic properties of the hydrogels were similar to native tissue, as reflected in the complex shear modulus (?11-14 kPa for hydrogels, 11.3 kPa for native NP). Cultured NP cells not only attached to the hydrogels but also survived, proliferated, and maintained their round morphology. Importantly, we found that hydrogels increased NP cell expression of several crucial ECM-related genes, such as COL2A1, AGN, SOX-9, and HIF-1A. PMID:23041783

Chen, Yu-Chun; Su, Wen-Yu; Yang, Shu-Hua; Gefen, Amit; Lin, Feng-Huei

2013-02-01

66

A new non-enzymatic method for isolating human intervertebral disc cells preserves the phenotype of nucleus pulposus cells.  

PubMed

Cells isolated from intervertebral disc (IVD) tissues of human surgical samples are one of potential sources for the IVD cellular therapy. The purpose of this study was to develop a new non-enzymatic method, "tissue incubation", for isolating human IVD cells. The IVD tissues of annulus fibrosus (AF) and nucleus pulposus (NP) were incubated separately in tissue culture flasks with culture medium. After 7-10 days incubation, cells were able to migrate out of IVD tissues and proliferate in vitro. After 3-4 weeks culture, expanded cells were harvested by trypsinization, and the remaining tissues were transferred to a new flask for another round of incubation. The molecular phenotype of IVD cells from juvenile and adult human samples was evaluated by both flow cytometry analysis and immunocytochemical staining for the expression of protein markers of NP cells (CD24, CD54, CD239, integrin ?6 and laminin ?5). Flow cytometry confirmed that both AF and NP cells of all ages positively expressed CD54 and integrin ?6, with higher expression levels in NP cells than in AF cells for the juvenile group sample. However, CD24 expression was only found in juvenile NP cells, and not in AF or older disc cells. Similar expression patterns for NP markers were also confirmed by immunocytochemistry. In summary, this new non-enzymatic tissue incubation method for cell isolation preserves molecular phenotypic markers of NP cells and may provide a valuable cell source for the study of NP regeneration strategies. PMID:24101443

Tang, Xinyan; Richardson, William J; Fitch, Robert D; Brown, Christopher R; Isaacs, Robert E; Chen, Jun

2014-12-01

67

Nucleus pulposus cells expressing hBMP7 can prevent the degeneration of allogenic IVD in a canine transplantation model.  

PubMed

We have previously explored the possibilities of allogenic intervertebral disc (IVD) curing disc degeneration disease in clinical practice. The results showed that the motion and stability of the spinal unit was preserved after transplantation of allogenic IVD in human beings at 5-year follow-up. However, mild degeneration was observed in the allogenic transplanted IVD cases. In this study, we construct the biological tissue engineering IVD by injecting the nucleus pulposus cells (NPCs) expressing human bone morphogenetic protein 7 (hBMP7) into cryopreserved IVD, and transplant the biological tissue engineering IVD into a beagle dog to investigate whether NPCs expressing hBMP7 could prevent the degeneration of the transplanted allogenic IVDs. At 24 weeks after transplantation, MRI scan showed that IVD allografts injected NPCs expressing hBMP7 have a slighter signs of degeneration than IVD allografts with NPCs or without NPCs. The range of motion of left-right rotation in the group without NPCs was bigger than that of two cells injection group. PKH-26-labeled cells were identified at IVD allograft. The study demonstrated that NPCs expressing hBMP7 could survive at least 24 weeks and prevent the degeneration of the transplanted IVD. This solution might have a potential role in preventing the IVD allograft degeneration in long time follow-up. PMID:23580474

Chaofeng, Wang; Chao, Zhang; Deli, Wang; Jianhong, Wu; Yan, Zhang; Cheng, Xu; Hongkui, Xin; Qing, He; Dike, Ruan

2013-09-01

68

Shh Signaling from the Nucleus Pulposus Is Required for the Postnatal Growth and Differentiation of the Mouse Intervertebral Disc  

PubMed Central

Intervertebral discs (IVD) are essential components of the vertebral column. They maintain separation, and provide shock absorbing buffers, between adjacent vertebrae, while also allowing movements between them. Each IVD consists of a central semi-liquid nucleus pulposus (NP) surrounded by a multi-layered fibrocartilagenous annulus fibrosus (AF). Although the IVDs grow and differentiate after birth along with the vertebral column, little is known about the mechanism of this. Understanding the signals that control normal IVD growth and differentiation would also provide potential therapies for degenerative disc disease, which is the major cause of lower back pain and affects a large proportion of the population. In this work, we show that during postnatal growth of the mouse, Sonic hedgehog (Shh) signaling from the NP cells controls many aspects of growth and differentiation of both the NP cells themselves and of the surrounding AF, and that it acts, at least partly, by regulating other signaling pathways in the NP and AF. Recent studies have shown that the NP cells arise from the embryonic notochord, which acts as a major signaling center in the embryo. This work shows that this notochord-derived tissue continues to carry out a major signaling function in the postnatal body and that the IVDs are signaling centers, in addition to their already known functions in the mechanics of vertebral column function. PMID:22558278

Dahia, Chitra Lekha; Mahoney, Eric; Wylie, Christopher

2012-01-01

69

Functional compressive mechanics of a PVA\\/PVP nucleus pulposus replacement  

Microsoft Academic Search

Emerging techniques as an alternative to the current treatments of lower back pain include nucleus replacement by an artificial material, which aims to relieve pain and restore the normal spinal motion. The compressive mechanical behavior of the PVA\\/PVP hydrogel nucleus implant was assessed in the present study.PVA\\/PVP hydrogels were made with various PVP concentrations. The hydrogels were loaded statically under

Abhijeet Joshi; Garland Fussell; Jonathan Thomas; Andrew Hsuan; Anthony Lowman; Andrew Karduna; Ed Vresilovic; Michele Marcolongo

2006-01-01

70

Loss of HIF-1? in the Notochord Results in Cell Death and Complete Disappearance of the Nucleus Pulposus  

PubMed Central

The intervertebral disc (IVD) is one of the largest avascular organs in vertebrates. The nucleus pulposus (NP), a highly hydrated and proteoglycan-enriched tissue, forms the inner portion of the IVD. The NP is surrounded by a multi-lamellar fibrocartilaginous structure, the annulus fibrosus (AF). This structure is covered superior and inferior side by cartilaginous endplates (CEP). The NP is a unique tissue within the IVD as it results from the differentiation of notochordal cells, whereas, AF and CEP derive from the sclerotome. The hypoxia inducible factor-1? (HIF-1?) is expressed in NP cells but its function in NP development and homeostasis is largely unknown. We thus conditionally deleted HIF-1? in notochordal cells and investigated how loss of this transcription factor impacts NP formation and homeostasis at E15.5, birth, 1 and 4 months of age, respectively. Histological analysis, cell lineage studies, and TUNEL assay were performed. Morphologic changes of the mutant NP cells were identified as early as E15.5, followed, postnatally, by the progressive disappearance and replacement of the NP with a novel tissue that resembles fibrocartilage. Notably, lineage studies and TUNEL assay unequivocally proved that NP cells did not transdifferentiate into chondrocyte-like cells but they rather underwent massive cell death, and were completely replaced by a cell population belonging to a lineage distinct from the notochordal one. Finally, to evaluate the functional consequences of HIF-1? deletion in the NP, biomechanical testing of mutant IVD was performed. Loss of the NP in mutant mice significantly reduced the IVD biomechanical properties by decreasing its ability to absorb mechanical stress. These findings are similar to the changes usually observed during human IVD degeneration. Our study thus demonstrates that HIF-1? is essential for NP development and homeostasis, and it raises the intriguing possibility that this transcription factor could be involved in IVD degeneration in humans. PMID:25338007

Robling, Alexander; Wilson, Tremika LeShan; Giaccia, Amato J.; Shapiro, Irving M.; Schipani, Ernestina; Risbud, Makarand V.

2014-01-01

71

Phenotypic stability, matrix elaboration and functional maturation of nucleus pulposus cells encapsulated in photocrosslinkable hyaluronic acid hydrogels.  

PubMed

Degradation of the nucleus pulposus (NP) is an early hallmark of intervertebral disc degeneration. The capacity for endogenous regeneration in the NP is limited due to the low cellularity and poor nutrient and vascular supply. Towards restoring the NP, a number of biomaterials have been explored for cell delivery. These materials must support the NP cell phenotype while promoting the elaboration of an NP-like extracellular matrix in the shortest possible time. Our previous work with chondrocytes and mesenchymal stem cells demonstrated that hydrogels based on hyaluronic acid (HA) are effective at promoting matrix production and the development of functional material properties. However, this material has not been evaluated in the context of NP cells. Therefore, to test this material for NP regeneration, bovine NP cells were encapsulated in 1%w/vol HA hydrogels at either a low seeding density (20×10(6)cellsml(-1)) or a high seeding density (60×10(6)cellsml(-1)), and constructs were cultured over an 8week period. These NP cell-laden HA hydrogels showed functional matrix accumulation, with increasing matrix content and mechanical properties with time in culture at both seeding densities. Furthermore, encapsulated cells showed NP-specific gene expression profiles that were significantly higher than expanded NP cells prior to encapsulation, suggesting a restoration of phenotype. Interestingly, these levels were higher at the lower seeding density compared to the higher seeding density. These findings support the use of HA-based hydrogels for NP tissue engineering and cellular therapies directed at restoration or replacement of the endogenous NP. PMID:25448344

Kim, Dong Hwa; Martin, John T; Elliott, Dawn M; Smith, Lachlan J; Mauck, Robert L

2015-01-15

72

Can notochordal cells promote bone marrow stromal cell potential for nucleus pulposus enrichment? A simplified in vitro system.  

PubMed

Bone marrow stromal cells (BMSCs) have shown promising potential to stop intervertebral disc degeneration in several animal models. In order to restore a healthy state, though, this potential should be further stimulated. Notochordal cells (NCs), influential in disc development, have been shown to stimulate BMSC differentiation, but it is unclear how this effect will translate in an environment where resident disc cells (nucleus pulposus cells [NPCs]) could also influence BMSCs. The goal of this study was, therefore, to evaluate the effects of NCs on BMSCs when cocultured with NPCs, in a simplified 3D in vitro system. Bovine BMSCs and NPCs were mixed (Mix) and seeded into alginate beads. Using culture inserts, the Mix was then cocultured with porcine NCs (alginate beads) and compared to coculture with empty beads or porcine skin fibroblasts (SFs, alginate beads). NPCs alone were also cocultured with NCs, and BMSCs alone cultured under chondrogenic conditions. The effects of coculture conditions on cell viability, matrix production (proteoglycan and collagen), and gene expression of disc markers (aggrecan, type II collagen, and SOX9) were assessed after 4 weeks of culture. The NC phenotype and gene expression profile were also analyzed. Coculture with NCs did not significantly influence cell viability, proteoglycan production, or disc marker gene expression of the Mix. When compared to NPCs, the Mix produced the same amount of proteoglycan and displayed a higher expression of disc marker, indicating a stimulation of the BMSCs (and/or NPCs) in the Mix. Additionally, during the 4 weeks of culture, the NC phenotype changed drastically (morphology, gene expression profile). These results show that NCs might not be as stimulatory for BMSCs in an NPC-rich environment, as believed from individual cultures. This absence of effects could be explained by a mild stimulation provided by (de)differentiating NCs and the costimulation of BMSCs and NPCs by each other. PMID:24873993

Potier, Esther; Ito, Keita

2014-12-01

73

Effects of nucleus pulposus cell-derived acellular matrix on the differentiation of mesenchymal stem cells.  

PubMed

Recent attempts to treat disc degeneration with mesenchymal stem cells (MSCs) showed encouraging results. Differentiating MSCs towards nucleus pulposus cell (NPC)-like lineages represents a speculative mechanism. Niche factors including hypoxia, growth factors and cell-cell interactions have been suggested but the matrix niche factor has not been studied. Our collagen microencapsulation provides a 3D model to study matrix niche as it enables the encapsulated cells to remodel the template matrix. We previously demonstrated the chondro-inductive role of of chondrocytes-derived matrix in MSCs and showed that NPCs maintained their phenotype and remodeled the template matrix of collagen microspheres into a glycosaminoglycan (GAG)-rich one. Here we aim to study the effects of NPC-derived matrix on MSC differentiation towards NPC-like lineages by firstly producing an NPC-derived matrix in collagen microspheres, secondly optimizing a decellularization protocol to discard NPCs yet retaining the matrix, thirdly repopulating the acellular NPC-derived matrix with MSCs and fourthly evaluating their phenotype. Finally, we injected these microspheres in a pilot rabbit disc degeneration model. Results showed that NPCs survived, maintained their phenotypic markers and produced GAGs. A decellularization protocol with maximal removal of the NPCs, minimal loss in major matrix components and partial retention of NPC-specific markers was identified. The resulting acellular matrix supported MSC survival and matrix production, and up-regulated the gene expression of NPC markers including type II collagen and glypican 3. Finally, injection of MSC in these microspheres in rabbit degenerative disc better maintained hydration level with more pronounced staining of GAGs and type II collagen than controls. PMID:23465833

Yuan, Minting; Yeung, Chiu Wai; Li, Yuk Yin; Diao, Huajia; Cheung, K M C; Chan, D; Cheah, K; Chan, Pui Barbara

2013-05-01

74

Injectable hydrogels with high fixed charge density and swelling pressure for nucleus pulposus repair: biomimetic glycosaminoglycan analogues.  

PubMed

The load-bearing biomechanical role of the intervertebral disc is governed by the composition and organization of its major macromolecular components, collagen and aggrecan. The major function of aggrecan is to maintain tissue hydration, and hence disc height, under the high loads imposed by muscle activity and body weight. Key to this role is the high negative fixed charge of its glycosaminoglycan side chains, which impart a high osmotic pressure to the tissue, thus regulating and maintaining tissue hydration and hence disc height under load. In degenerate discs, aggrecan degrades and is lost from the disc, particularly centrally from the nucleus pulposus. This loss of fixed charge results in reduced hydration and loss of disc height; such changes are closely associated with low back pain. The present authors developed biomimetic glycosaminoglycan analogues based on sulphonate-containing polymers. These biomimetics are deliverable via injection into the disc where they polymerize in situ, forming a non-degradable, nuclear "implant" aimed at restoring disc height to degenerate discs, thereby relieving back pain. In vitro, these glycosaminoglycan analogues possess appropriate fixed charge density, hydration and osmotic responsiveness, thereby displaying the capacity to restore disc height and function. Preliminary biomechanical tests using a degenerate explant model showed that the implant adapts to the space into which it is injected and restores stiffness. These hydrogels mimic the role taken by glycosaminoglycans in vivo and, unlike other hydrogels, provide an intrinsic swelling pressure, which can maintain disc hydration and height under the high and variable compressive loads encountered in vivo. PMID:24270091

Sivan, S S; Roberts, S; Urban, J P G; Menage, J; Bramhill, J; Campbell, D; Franklin, V J; Lydon, F; Merkher, Y; Maroudas, A; Tighe, B J

2014-03-01

75

Loss of HIF-1? in the notochord results in cell death and complete disappearance of the nucleus pulposus.  

PubMed

The intervertebral disc (IVD) is one of the largest avascular organs in vertebrates. The nucleus pulposus (NP), a highly hydrated and proteoglycan-enriched tissue, forms the inner portion of the IVD. The NP is surrounded by a multi-lamellar fibrocartilaginous structure, the annulus fibrosus (AF). This structure is covered superior and inferior side by cartilaginous endplates (CEP). The NP is a unique tissue within the IVD as it results from the differentiation of notochordal cells, whereas, AF and CEP derive from the sclerotome. The hypoxia inducible factor-1? (HIF-1?) is expressed in NP cells but its function in NP development and homeostasis is largely unknown. We thus conditionally deleted HIF-1? in notochordal cells and investigated how loss of this transcription factor impacts NP formation and homeostasis at E15.5, birth, 1 and 4 months of age, respectively. Histological analysis, cell lineage studies, and TUNEL assay were performed. Morphologic changes of the mutant NP cells were identified as early as E15.5, followed, postnatally, by the progressive disappearance and replacement of the NP with a novel tissue that resembles fibrocartilage. Notably, lineage studies and TUNEL assay unequivocally proved that NP cells did not transdifferentiate into chondrocyte-like cells but they rather underwent massive cell death, and were completely replaced by a cell population belonging to a lineage distinct from the notochordal one. Finally, to evaluate the functional consequences of HIF-1? deletion in the NP, biomechanical testing of mutant IVD was performed. Loss of the NP in mutant mice significantly reduced the IVD biomechanical properties by decreasing its ability to absorb mechanical stress. These findings are similar to the changes usually observed during human IVD degeneration. Our study thus demonstrates that HIF-1? is essential for NP development and homeostasis, and it raises the intriguing possibility that this transcription factor could be involved in IVD degeneration in humans. PMID:25338007

Merceron, Christophe; Mangiavini, Laura; Robling, Alexander; Wilson, Tremika LeShan; Giaccia, Amato J; Shapiro, Irving M; Schipani, Ernestina; Risbud, Makarand V

2014-01-01

76

Expression of Prolyl Hydroxylases (PHDs) Is Selectively Controlled by HIF-1 and HIF-2 Proteins in Nucleus Pulposus Cells of the Intervertebral Disc  

PubMed Central

Adaptive response to hypoxia in nucleus pulposus cells of the intervertebral disc is regulated by the hypoxia-inducible factors, HIF-1? and HIF-2?. Moreover, oxygen-dependent turnover of HIF-1? in these cells is controlled by the prolyl-4-hydroxylase domain (PHD) family of proteins. Whether HIF homologues control expression of PHDs and whether PHDs control hypoxia-inducible factor (HIF) turnover and/or activity under hypoxia is not known. Here, we show that in nucleus pulposus cells, hypoxia robustly induces PHD3 expression and, to a lesser extent, of PHD2 and PHD1. Reporter analysis shows that the hypoxic induction of the PHD2 promoter is HIF-1? dependent, whereas PHD3 promoter/enhancer activity is dependent on both HIF-1? and HIF-2?. Lentiviral delivery of HIF-1?, ShHIF-1?, and ShHIF-1? confirmed these observations. Noteworthy, HIF-1? maintains basal expression of PHD1 in hypoxia at the posttranscriptional level. Finally, loss of function studies using lentiviral transduction of ShPHDs clearly shows that even at 1% O2, PHD2 selectively degrades HIF-1?. In contrast, in hypoxia, PHD3 enhances HIF-1? transcriptional activity without affecting protein levels. To correlate these observations with disc disease, a condition characterized by tissue vascularization, we analyzed human tissues. Increased PHD1 mRNA expression but decreased PHD2 and PHD3 expression is observed in degenerate tissues. Interestingly, the hypoxic responsiveness of all the PHDs is maintained in isolated nucleus pulposus cells regardless of the disease state. We propose that PHD2 and PHD3 can be used as a biomarker of tissue oxygenation in the disc and that, as such, it may have important clinical implications. PMID:22451659

Fujita, Nobuyuki; Markova, Dessislava; Anderson, D. Greg; Chiba, Kazuhiro; Toyama, Yoshiaki; Shapiro, Irving M.; Risbud, Makarand V.

2012-01-01

77

Treatment of lumbar disc herniation by percutaneous laser disc decompression (PLDD) and modified PLDD  

NASA Astrophysics Data System (ADS)

Objective: To study the micro-invasive operative method and to compare the effect of treatment of PLDD and modified PLDD for Lumbar Disc Herniation. Method: Vaporized part of the nucleus pulposus in single or multiple point after acupuncture into lumbar disc, to reach the purpose of the decompression of the lumbar disc. Result: Among the 19 cases of the regular PLDD group, the excellent and good rate was 63.2%, and among the 40 cases of the modified PLDD group, the excellent and good rate was 82.5%. Conclusion: The modified PLDD has good effect on the treatment for lumbar disc herniation.

Chi, Xiao fei; Li, Hong zhi; Wu, Ru zhou; Sui, Yun xian

2005-07-01

78

THORACOLUMBAR INTRADURAL DISC HERNIATION IN EIGHT DOGS: CLINICAL, LOW-FIELD MAGNETIC RESONANCE IMAGING, AND COMPUTED TOMOGRAPHIC MYELOGRAPHY FINDINGS.  

PubMed

Intradural disc herniation is a rarely reported cause of neurologic deficits in dogs and few published studies have described comparative imaging characteristics. The purpose of this retrospective cross sectional study was to describe clinical and imaging findings in a group of dogs with confirmed thoracolumbar intradural disc herniation. Included dogs were referred to one of four clinics, had acute mono/paraparesis or paraplegia, had low field magnetic resonance imaging (MRI) and/or computed tomographic myelography, and were diagnosed with thoracolumbar intradural disc herniation during surgery. Eight dogs met inclusion criteria. The prevalence of thoracolumbar intradural disc herniation amongst the total population of dogs that developed a thoracolumbar intervertebral disc herniation and that were treated with a surgical procedure was 0.5%. Five dogs were examined using low-field MRI. Lesions that were suspected to be intervertebral disc herniations were observed; however, there were no specific findings indicating that the nucleus pulposus had penetrated into the subarachnoid space or into the spinal cord parenchyma. Thus, the dogs were misdiagnosed as having a conventional intervertebral disc herniation. An intradural extramedullary disc herniation (three cases) or intramedullary disc herniation (two cases) was confirmed during surgery. By using computed tomographic myelography (CTM) for the remaining three dogs, an intradural extramedullary mass surrounded by an accumulation of contrast medium was observed and confirmed during surgery. Findings from this small sample of eight dogs indicated that CTM may be more sensitive for diagnosing canine thoracolumbar intradural disc herniation than low-field MRI. PMID:25263808

Tamura, Shinji; Doi, Shoko; Tamura, Yumiko; Takahashi, Kuniaki; Enomoto, Hirokazu; Ozawa, Tsuyoshi; Uchida, Kazuyuki

2014-09-26

79

Expression of acid-sensing ion channels in nucleus pulposus cells of the human intervertebral disk is regulated by non-steroid anti-inflammatory drugs.  

PubMed

Non-steroid anti-inflammatory drugs (NSAIDs) are generally used in the treatment of inflammation and pain through cyclooxygenase (COX) inhibition. Mounting evidence has indicated additional COX-independent targets for NSAIDs including acid-sensing ion channels (ASICs) 1a and 3. However, detailed function and mechanism of ASICs still remain largely elusive. In this study, the impact of NSAIDs on ASICs in nucleus pulposus cells of the human intervertebral disk was investigated. Nucleus pulposus cells were isolated and cultured from protruded disk tissues of 40 patients. It was shown that ASIC1a and ASIC3 were expressed and functional in these cells by analyzing proton-gated currents after ASIC inhibition. We further investigated the neuroprotective capacity of ibuprofen (a COX inhibitor), psalmotoxin-1 (PcTX1, a tarantula toxin specific for homomeric ASIC1a), and amiloride (a classic inhibitor of the epithelial sodium channel ENaC/DEG family to which ASICs belong). PcTX1-containing venom has been shown to be comparable with amiloride in its neuroprotective features in rodent models of ischemia. Taken together, our data showed that amiloride, PcTX1, and ibuprofen decreased ASIC protein expression and thereby exerted protective effects from ASIC inhibition-mediated cell damage. PMID:25079679

Sun, Xue; Jin, Jun; Zhang, Ji-Gang; Qi, Lin; Braun, Frank Karl; Zhang, Xing-Ding; Xu, Feng

2014-09-01

80

Differential response of encapsulated nucleus pulposus and bone marrow stem cells in isolation and coculture in alginate and chitosan hydrogels.  

PubMed

Cell-based therapies may hold significant promise for the treatment of early stage degeneration of the intervertebral disc (IVD). Given their propensity to proliferate and ability to form multiple tissue types, mesenchymal stem cells (MSCs) have been proposed as a potential cell source to promote repair of the nucleus pulposus (NP). However, for any successful cell-based therapy, a carrier biomaterial may be essential for targeted delivery providing key biophysical and biochemical cues to facilitate differentiation of MSCs. Two widely used biomaterials for NP regeneration are chitosan and alginate. The primary objective of this study was to assess the influence of alginate and chitosan hydrogels on bone marrow stem cells (BM) and NP cells in isolation or in coculture. A secondary objective of this study was to investigate coculture seeding density effects of BM and NP cells and simultaneously explore which cell type is responsible for matrix formation in a cocultured environment. Porcine NP and BM cells were encapsulated in alginate and chitosan hydrogels separately at two seeding densities (4×10(6) and 8×10(6) cells/mL) or in coculture (1:1, 8×10(6) cells/mL). Constructs (diameter=5?mm, height=3?mm) were maintained under IVD-like conditions [low-glucose, low (5%) oxygen] with or without transforming growth factor-?3 (TGF-?3) supplementation for 21 days. Results demonstrated differential viability depending on hydrogel type. NP cells remained viable in both biomaterial types whereas BM viability was diminished in chitosan. Further, hydrogel type was found to regulate sulfated glycosaminoglycan (sGAG) and collagen accumulation. Specifically, alginate better supports sGAG accumulation and collagen type II deposition for both NP and BM cell types compared with chitosan. Having identified that alginate more readily supports cell viability and matrix accumulation, we further explored additional effects of seeding density ratios (NP:BM-1:1, 1:2) for coculture studies. Interestingly, in coculture conditions, the BM cell population declined in number while NP cells increased, indicating that MSCs may in fact be signaling NP cells to proliferate rather than contributing to matrix formation. These findings provide exciting new insights on the potential of MSCs for NP tissue regeneration strategies. PMID:25060596

Naqvi, Syeda Masooma; Buckley, Conor Timothy

2015-01-01

81

Notochordal cells protect nucleus pulposus cells from degradation and apoptosis: implications for the mechanisms of intervertebral disc degeneration  

PubMed Central

Introduction The relative resistance of non-chondrodystrophic (NCD) canines to degenerative disc disease (DDD) may be due to a combination of anabolic and anti-catabolic factors secreted by notochordal cells within the intervertebral disc (IVD) nucleus pulposus (NP). Factors known to induce DDD include interleukin-1 beta (IL-1ß) and/or Fas-Ligand (Fas-L). Therefore we evaluated the ability of notochordal cell conditioned medium (NCCM) to protect NP cells from IL-1ß and IL-1ß +FasL-mediated cell death and degeneration. Methods We cultured bovine NP cells with IL-1ß or IL-1ß+FasL under hypoxic serum-free conditions (3.5% O2) and treated the cells with either serum-free NCCM or basal medium (Advanced DMEM/F-12). We used flow cytometry to evaluate cell death and real-time (RT-)PCR to determine the gene expression of aggrecan, collagen 2, and link protein, mediators of matrix degradation ADAMTS-4 and MMP3, the matrix protection molecule TIMP1, the cluster of differentiation (CD)44 receptor, the inflammatory cytokine IL-6 and Ank. We then determined the expression of specific apoptotic pathways in bovine NP cells by characterizing the expression of activated caspases-3, -8 and -9 in the presence of IL-1ß+FasL when cultured with NCCM, conditioned medium obtained using bovine NP cells (BCCM), and basal medium all supplemented with 2% FBS. Results NCCM inhibits bovine NP cell death and apoptosis via suppression of activated caspase-9 and caspase-3/7. Furthermore, NCCM protects NP cells from the degradative effects of IL-1ß and IL-1ß+Fas-L by up-regulating the expression of anabolic/matrix protective genes (aggrecan, collagen type 2, CD44, link protein and TIMP-1) and down-regulating matrix degrading genes such as MMP-3. Expression of ADAMTS-4, which encodes a protein for aggrecan remodeling, is increased. NCCM also protects against IL-1+FasL-mediated down-regulation of Ank expression. Furthermore, NP cells treated with NCCM in the presence of IL-1ß+Fas-L down-regulate the expression of IL-6 by almost 50%. BCCM does not mediate cell death/apoptosis in target bovine NP cells. Conclusions Notochordal cell-secreted factors suppress NP cell death by inhibition of activated caspase-9 and -3/7 activity and by up-regulating genes contributing anabolic activity and matrix protection of the IVD NP. Harnessing the restorative powers of the notochordal cell could lead to novel cellular and molecular strategies in the treatment of DDD. PMID:22206702

2011-01-01

82

Differentiation of GFP-Bcl-2-engineered mesenchymal stem cells towards a nucleus pulposus-like phenotype under hypoxia in vitro.  

PubMed

Differentiation of bone marrow-derived mesenchymal stem cells (MSCs) into a nucleus pulposus-like phenotype under hypoxia has been proposed as a potential therapeutic approach for intervertebral disc degeneration. However, limited cell viability under hypoxic conditions has restricted MSC differentiation capacity and thus restricted its clinical application. In this study, we genetically modified MSCs with an anti-apoptotic GFP-Bcl-2 gene and evaluated cell survival and functional improvement under hypoxia in vitro. Rat bone marrow MSCs were transfected by lentiviral vectors with the GFP-Bcl-2 gene (GFP-Bcl-2-MSCs). Cell proliferation and apoptosis were assessed, and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) was carried out to evaluate phenotypic and biosynthetic activities. In addition, Alcian blue staining was used to detect the formation of sulfated glycosaminoglycans (GAGs) in the differentiated cells. We found that the Bcl-2 gene protected MSCs against apoptosis. We also observed that Bcl-2 over-expression reduced apoptosis by 40.61% in non-transfected MSCs and 38.43% in vector-MSCs to 18.33% in Bcl-2-MSCs. At 3days, the number of viable Bcl-2-MSCs was approximately two times higher than the number of MSCs or vector-MSCs under hypoxic conditions. RT-PCR showed higher expression of chondrocyte-related genes (Sox-9, aggrecan and type II collagen) in GFP-Bcl-2-MSCs cultured under hypoxia. The accumulation of proteoglycans in the pellet was 86% higher in GFP-Bcl-2-MSCs than in the control groups. Furthermore, the ratio of proteoglycans/collagen II in GFP-Bcl-2-MSCs was 6.2-fold higher compared to the MSC and vector-MSC groups, which denoted a nucleus pulposus-like differentiation phenotype. Our findings support the hypothesis that anti-apoptotic gene-modified MSCs can differentiate into cells with a nucleus pulposus-like phenotype in vitro, which may have value for the regeneration of intervertebral discs using cell transplantation therapy. PMID:23416353

Fang, Zhong; Yang, Qin; Luo, Wei; Li, Guang-hui; Xiao, Jun; Li, Feng; Xiong, Wei

2013-03-15

83

The role of extracellular matrix elasticity and composition in regulating the nucleus pulposus cell phenotype in the intervertebral disc: a narrative review.  

PubMed

Intervertebral disc (IVD) disorders are a major contributor to disability and societal health care costs. Nucleus pulposus (NP) cells of the IVD exhibit changes in both phenotype and morphology with aging-related IVD degeneration that may impact the onset and progression of IVD pathology. Studies have demonstrated that immature NP cell interactions with their extracellular matrix (ECM) may be key regulators of cellular phenotype, metabolism and morphology. The objective of this article is to review our recent experience with studies of NP cell-ECM interactions that reveal how ECM cues can be manipulated to promote an immature NP cell phenotype and morphology. Findings demonstrate the importance of a soft (<700 Pa), laminin-containing ECM in regulating healthy, immature NP cells. Knowledge of NP cell-ECM interactions can be used for development of tissue engineering or cell delivery strategies to treat IVD-related disorders. PMID:24390195

Hwang, Priscilla Y; Chen, Jun; Jing, Liufang; Hoffman, Brenton D; Setton, Lori A

2014-02-01

84

Dynamic compression and co-culture with nucleus pulposus cells promotes proliferation and differentiation of adipose-derived mesenchymal stem cells.  

PubMed

Adipose-derived stem cells (ASCs) are a set of multi potent stem cells potentially used in cartilage tissue engineering. We hypothesized that the effect of dynamic compression and co-culture with nucleus pulposus cells (NPCs) promotes ASC proliferation and chondrogenic differentiation. A controlled dynamic compression loading device was utilized to stimulate ASCs obtained from Sprague Dawley (SD) rats and identified by flow cytometry. The proliferation index was measured by carboxyfluorescein succinimidyl ester (CFSE) staining. Dynamic compression, as well as co-culture enhanced chondrogenic differentiation of ASCs as indicated by the expression of SOX-9, type-II collagen and aggrecan, which were measured by real-time PCR and Western blot. In our study, we found dynamic compression promoted the proliferation of ASCs and induced its differentiation into NP-like cells. Combination of dynamic compression and co-culture showed an additive effect on NP-like cell differentiation. PMID:24529753

Dai, Jun; Wang, Huan; Liu, Guo; Xu, Zhanjiang; Li, Feng; Fang, Huang

2014-03-21

85

The catabolic effect of TNF? on bovine nucleus pulposus intervertebral disc cells and the restraining role of glucosamine sulfate in the TNF?-mediated up-regulation of MMP-3.  

PubMed

Glucosamine is an endogenous amino monosaccharide naturally occurring in the cartilage. We have recently shown that glucosamine sulfate promotes the biosynthesis of glycosaminoglycans in intervertebral disc cells. Here we assessed the role of glucosamine sulfate in the response of bovine nucleus pulposus cell monolayers to TNF? that constitutes an early signal of disc degeneration. TNF? was not found to affect nucleus pulposus cells' viability, while it resulted in a ?2.5-fold increase of the intracellular ROS levels, a rapid transient phosphorylation of p38 MAPK and a ROS-dependent activation of JNKs. In addition, TNF? had a prominent inflammatory effect on nucleus pulposus cells by up-regulating MMP-3 expression that was reversed when inhibiting the kinase activity of p38 MAPK. Glucosamine sulfate also diminished the increased by TNF? MMP-3 mRNA levels, but this was unrelated to the p38 MAPK or ROS-mediated JNK activation. Even though the mode of action of glucosamine towards TNF? remains to be elucidated, to the best of our knowledge, this is the first report providing evidence for the protective role of glucosamine against this early mediator of disc degeneration that could support the potential usage of this molecule as a treatment for preventing disc degenerative disorders. PMID:25220975

Mavrogonatou, Eleni; Angelopoulou, Maria T; Kletsas, Dimitris

2014-12-01

86

Development and initial characterization of a chemically stabilized elastin-glycosaminoglycan-collagen composite shape-memory hydrogel for nucleus pulposus regeneration.  

PubMed

Nucleus pulposus (NP) is a resilient and hydrophilic tissue which plays a significant role in the biomechanical function of the intervertebral disc (IVD). Destruction of the NP extracellular matrix (ECM) is observed during the early stages of IVD degeneration. Herein, we describe the development and initial characterization of a novel biomaterial which attempts to recreate the resilient and hydrophilic nature of the NP via the construction of a chemically stabilized elastin-glycosaminoglycan-collagen (EGC) composite hydrogel. Results demonstrated that a resilient, hydrophilic hydrogel which displays a unique "shape-memory" sponge characteristic could be formed from a blend of soluble elastin aggregates, chondroitin-6-sulfate, hyaluronic acid and collagen following freeze-drying, stabilization with a carbodiimide and penta-galloyl glucose-based fixative, and subsequent partial degradation with glycosaminoglycan degrading enzymes. The resultant material exhibited the ability to restore its original dimensions and water content following multi-cycle mechanical compression and illustrated resistance to accelerated enzymatic degradation. Preliminary in vitro studies utilizing human adipose derived stem cells (hADSCs) demonstrated that the material was cytocompatible and supported differentiation towards an NP cell-like phenotype. In vivo biocompatibility studies illustrated host cell infiltration and evidence of active remodeling following 4 weeks of implantation. Feasibility studies demonstrated that the EGC hydrogel could be delivered via minimally invasive methods. PMID:24497431

Mercuri, Jeremy; Addington, Caroline; Pascal, Richard; Gill, Sanjitpal; Simionescu, Dan

2014-12-01

87

Native nucleus pulposus tissue matrix promotes notochordal differentiation of human induced pluripotent stem cells with potential for treating intervertebral disc degeneration.  

PubMed

Native porcine nucleus pulposus (NP) tissue harbors a number of notochordal cells (NCs). Whether the native NP matrix supports the homeostasis of notochordal cells is poorly understood. We hypothesized the NP matrix alone may contain sufficient regulatory factors and can serve as stimuli to generate notochordal cells (NCs) from human pluripotent stem cells. NCs are a promising cell sources for cell-based therapy to treat some types of intervertebral disc (IVD) degeneration. One major limitation of this emerging technique is the lack of available NCs as a potential therapeutic cell source. Human pluripotent stem cells derived from reprogramming or somatic cell nuclear transfer technique may yield stable and unlimited source for therapeutic use. We devised a new method to use porcine NP matrix to direct notochordal differentiation of human induced pluripotent stem cells (hiPSCs). The results showed that hiPSCs successfully differentiated into NC-like cells under the influence of devitalized porcine NP matrix. The NC-like cells expressed typical notochordal marker genes including brachyury (T), cytokeratin-8 (CK-8) and cytokeratin-18 (CK-18), and they displayed the ability to generate NP-like tissue in vitro, which was rich in aggrecan and collagen type II. These findings demonstrated the proof of concept for using native NP matrix to direct notochordal differentiation of hiPSCs. It provides a foundation for further understanding the biology of NCs, and eventually towards regenerative therapies for disc degeneration. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2014. PMID:24889905

Liu, Yongxing; Fu, Susan; Rahaman, Mohamed N; Mao, Jeremy J; Bal, B Sonny

2014-06-01

88

Characterization of injectable hydrogels based on poly(N-isopropylacrylamide)-g-chondroitin sulfate with adhesive properties for nucleus pulposus tissue engineering.  

PubMed

The goal of this work is to develop an injectable nucleus pulposus (NP) tissue engineering scaffold with the ability to form an adhesive interface with surrounding disc tissue. A family of in situ forming hydrogels based on poly(N-isopropylacrylamide)-graft-chondroitin sulfate (PNIPAAm-g-CS) were evaluated for their mechanical properties, bioadhesive strength, and cytocompatibility. It was shown experimentally and computationally with the Neo-hookean hyperelastic model that increasing the crosslink density and decreasing the CS concentration increased mechanical properties at 37 °C, generating several hydrogel formulations with unconfined compressive modulus values similar to what has been reported for the native NP. The adhesive tensile strength of PNIPAAm increased significantly with CS incorporation (p < 0.05), ranging from 0.4 to 1 kPa. Live/Dead and XTT assay results indicate that the copolymer is not cytotoxic to human embryonic kidney (HEK) 293 cells. Taken together, these data indicate the potential of PNIPAAm-g-CS to function as a scaffold for NP regeneration. PMID:23371764

Wiltsey, Craig; Kubinski, Pamela; Christiani, Thomas; Toomer, Katelynn; Sheehan, Joseph; Branda, Amanda; Kadlowec, Jennifer; Iftode, Cristina; Vernengo, Jennifer

2013-04-01

89

Defining the Phenotype of Young Healthy Nucleus Pulposus Cells: Recommendations of the Spine Research Interest Group at the 2014 Annual ORS Meeting.  

PubMed

Low back pain is a major physical and socioeconomic problem. Degeneration of the intervertebral disc and especially that of nucleus pulposus (NP) has been linked to low back pain. In spite of much research focusing on the NP, consensus among the research community is lacking in defining the NP cell phenotype. A consensus agreement will allow easier distinguishing of NP cells from annulus fibrosus (AF) cells and endplate chondrocytes, a better gauge of therapeutic success, and a better guidance of tissue-engineering-based regenerative strategies that attempt to replace lost NP tissue. Most importantly, a clear definition will further the understanding of physiology and function of NP cells, ultimately driving development of novel cell-based therapeutic modalities. The Spine Research Interest Group at the 2014 Annual ORS Meeting in New Orleans convened with the task of compiling a working definition of the NP cell phenotype with hope that a consensus statement will propel disc research forward into the future. Based on evaluation of recent studies describing characteristic NP markers and their physiologic relevance, we make the recommendation of the following healthy NP phenotypic markers: stabilized expression of HIF-1?, GLUT-1, aggrecan/collagen II ratio > 20, Shh, Brachyury, KRT18/19, CA12, and CD24. This article is protected by copyright. All rights reserved. PMID:25411088

Risbud, Makarand V; Schoepflin, Zachary R; Mwale, Fackson; Kandel, Rita A; Grad, Sibylle; Iatridis, James C; Sakai, Daisuke; Hoyland, Judith A

2014-11-20

90

Three-dimensional finite element modeling of pericellular matrix and cell mechanics in the nucleus pulposus of the intervertebral disk based on in situ morphology.  

PubMed

Nucleus pulposus (NP) cells of the intervertebral disk (IVD) have unique morphological characteristics and biologic responses to mechanical stimuli that may regulate maintenance and health of the IVD. NP cells reside as single cell, paired or multiple cells in a contiguous pericellular matrix (PCM), whose structure and properties may significantly influence cell and extracellular matrix mechanics. In this study, a computational model was developed to predict the stress-strain, fluid pressure and flow fields for cells and their surrounding PCM in the NP using three-dimensional (3D) finite element models based on the in situ morphology of cell-PCM regions of the mature rat NP, measured using confocal microscopy. Three-dimensional geometries of the extracellular matrix and representative cell-matrix units were used to construct 3D finite element models of the structures as isotropic and biphasic materials. In response to compressive strain of the extracellular matrix, NP cells and PCM regions were predicted to experience volumetric strains that were 1.9-3.7 and 1.4-2.1 times greater than the extracellular matrix, respectively. Volumetric and deviatoric strain concentrations were generally found at the cell/PCM interface, while von Mises stress concentrations were associated with the PCM/extracellular matrix interface. Cell-matrix units containing greater cell numbers were associated with higher peak cell strains and lower rates of fluid pressurization upon loading. These studies provide new model predictions for micromechanics of NP cells that can contribute to an understanding of mechanotransduction in the IVD and its changes with aging and degeneration. PMID:20376522

Cao, Li; Guilak, Farshid; Setton, Lori A

2011-02-01

91

In Vitro Characterization and In Vivo Behavior of Human Nucleus Pulposus and Annulus Fibrosus Cells in Clinical-Grade Fibrin and Collagen-Enriched Fibrin Gels.  

PubMed

The intervertebral disc (IVD) presents a limited self-repair ability and cell-based therapies have been suggested to prevent or treat IVD lesions. Fibrin-based scaffolds as cell carriers are promising candidates in IVD tissue engineering, thanks to their ability to be easily delivered into the defect and to adapt to the lesion shape, to support/retain the injected cells into the implantation site and to favor the production of a suitable extracellular matrix (ECM). We evaluated the in vitro and in vivo behavior of human nucleus pulposus (NP) and annulus fibrosus (AF) cells in a clinical-grade collagen-enriched fibrin that has never been tested before for orthopedic applications, comparing it with clinical-grade fibrin. The survival of IVD cells seeded within fibrin or collagen-enriched fibrin and the ECM synthesis were evaluated by biochemical, immunohistochemical, and transcriptional analyses, prior and after subcutaneous implantation of the gels in nude mice. After 28 days of implantation, NP and AF cells were still detectable within explants, produced tissue-specific ECM, and showed a higher content of glycosaminoglycans (GAGs) and type I and II collagen compared to gels before implantation. Both the fibrin gels, enriched or not with collagen, seemed to be suitable for the culture of AF cells, being able to support the homogeneous synthesis of type I collagen, characteristic of the native fibrocartilaginous AF tissue. Differently, fibrin alone was a more suitable matrix for NP culture, supporting the homogeneous deposition of GAGs and type II collagen. In conclusion, our results suggest to combine AF cells with fibrin, enriched or not with collagen, and NP cells with fibrin alone to maintain the typical features of these cell populations, indicating these clinical-grade materials as viable options in cell-based treatments for IVD lesions. PMID:25236589

Colombini, Alessandra; Lopa, Silvia; Ceriani, Cristina; Lovati, Arianna B; Croiset, Samantha J; Di Giancamillo, Alessia; Lombardi, Giovanni; Banfi, Giuseppe; Moretti, Matteo

2014-10-23

92

Insights into the Hallmarks of Human Nucleus Pulposus Cells with Particular Reference to Cell Viability, Phagocytic Potential and Long Process Formation  

PubMed Central

Objective: As a main cellular component within the disc, nucleus pulposus (NP) cells play important roles in disc physiology. However, little is known on the biologic hallmarks of human NP cells. Therefore, the present study aimed to address the features of human NP cells. Methods: Human NP samples were collected from normal cadavers, patients with scoliosis and disc degeneration as normal, disease control and degenerative NP, respectively. The NP samples were studied using transmission electron microscopy and TUNEL assay. Pre-digested NP samples were studied using flow cytometry with PI/Annexin V staining. Results: Both control and degenerative human NP consisted of mainly viable cells with a variety of morphology. Both necrosis and apoptosis were noted in human NP as forms of cell death with increased apoptosis in degenerative NP, which was further confirmed by the TUNEL assay. Phagocytic NP cells had the hallmarks of both stationary macrophages with lysosomes and NP cells with the endoplasmic reticulum. Annulus fibrosus cells have similar morphologic characteristics with NP cells in terms of cell nest, phagocytosis and intracellular organs. Moreover, NP cells with long processes existed in degenerative and scoliotic NP rather than normal NP. When cultured in glucose-free medium, NP cells developed long and thin processes. Conclusion: Human degenerative NP consists of primarily viable cells. We present direct and in vivo evidence that both human annulus fibrosus and NP cells have phagocytic potential. Moreover, NP cells with long processes exist in both scoliotic and degenerative NP with lack of glucose as one of the possible underlying mechanisms. PMID:24324357

Chen, Yu-Fei; Zhang, Yong-Zhao; Zhang, Wei-Lin; Luan, Guan-Nan; Liu, Zhi-Heng; Gao, Yang; Wan, Zhong-Yuan; Sun, Zhen; Zhu, Shu; Samartzis, Dino; Wang, Chun-Mei; Wang, Hai-Qiang; Luo, Zhuo-Jing

2013-01-01

93

Functional nucleus pulposus-like matrix assembly by human mesenchymal stromal cells is directed by macromer concentration in photocrosslinked carboxymethylcellulose hydrogels.  

PubMed

Intervertebral disc (IVD) degeneration is associated with several pathophysiologic changes of the IVD, including dehydration of the nucleus pulposus (NP). Tissue engineering strategies may be used to restore both biological and mechanical function of the IVD following removal of NP tissue during surgical intervention. Recently, photocrosslinked carboxymethylcellulose (CMC) hydrogels were shown to support chondrogenic, NP-like extracellular matrix (ECM) elaboration by human mesenchymal stromal cells (hMSCs) when supplemented with TGF-?3; however, mechanical properties of these constructs did not reach native values. Fabrication parameters (i.e., composition, crosslinking density) can influence the bulk mechanical properties of hydrogel scaffolds, as well as cellular behavior and differentiation patterns. The objective of this study was to evaluate the influence of CMC macromer concentration (1.5, 2.5 and 3.5 % weight/volume) on bulk hydrogel properties and NP-like matrix elaboration by hMSCs. The lowest macromer concentration of 1.5 % exhibited the highest gene expression levels of aggrecan and collagen II at day 7, corresponding with the largest accumulation of glycosaminoglycans and collagen II by day 42. The ECM elaboration in the 1.5 % constructs was more homogeneously distributed compared to primarily pericellular localization in 3.5 % gels. The 1.5 % gels also displayed significant improvements in mechanical functionality by day 42 compared to earlier time points, which was not seen in the other groups. The effects of macromer concentration on matrix accumulation and organization are likely attributed to quantifiable differences in polymer crosslinking density and diffusive properties between the various hydrogel formulations. Taken together, these results demonstrate that macromer concentration of CMC hydrogels can direct hMSC matrix elaboration, such that a lower polymer concentration allows for greater NP-like ECM assembly and improvement of mechanical properties over time. PMID:25092545

Gupta, Michelle S; Nicoll, Steven B

2014-11-01

94

In vitro characterization of a stem-cell-seeded triple-interpenetrating-network hydrogel for functional regeneration of the nucleus pulposus.  

PubMed

Intervertebral disc degeneration is implicated as a major cause of low-back pain. There is a pressing need for new regenerative therapies for disc degeneration that restore native tissue structure and mechanical function. To that end we investigated the therapeutic potential of an injectable, triple-interpenetrating-network hydrogel comprised of dextran, chitosan, and teleostean, for functional regeneration of the nucleus pulposus (NP) of the intervertebral disc in a series of biomechanical, cytotoxicity, and tissue engineering studies. Biomechanical properties were evaluated as a function of gelation time, with the hydrogel reaching ?90% of steady-state aggregate modulus within 10?h. Hydrogel mechanical properties evaluated in confined and unconfined compression were comparable to native human NP properties. To confirm containment within the disc under physiological loading, toluidine-blue-labeled hydrogel was injected into human cadaveric spine segments after creation of a nucleotomy defect, and the segments were subjected to 10,000 cycles of loading. Gross analysis demonstrated no implant extrusion, and further, that the hydrogel interdigitated well with native NP. Constructs were next surface-seeded with NP cells and cultured for 14 days, confirming lack of hydrogel cytotoxicity, with the hydrogel maintaining NP cell viability and promoting proliferation. Next, to evaluate the potential of the hydrogel to support cell-mediated matrix production, constructs were seeded with mesenchymal stem cells (MSCs) and cultured under prochondrogenic conditions for up to 42 days. Importantly, the hydrogel maintained MSC viability and promoted proliferation, as evidenced by increasing DNA content with culture duration. MSCs differentiated along a chondrogenic lineage, evidenced by upregulation of aggrecan and collagen II mRNA, and increased GAG and collagen content, and mechanical properties with increasing culture duration. Collectively, these results establish the therapeutic potential of this novel hydrogel for functional regeneration of the NP. Future work will confirm the ability of this hydrogel to normalize the mechanical stability of cadaveric human motion segments, and advance the material toward human translation using preclinical large-animal models. PMID:24410394

Smith, Lachlan J; Gorth, Deborah J; Showalter, Brent L; Chiaro, Joseph A; Beattie, Elizabeth E; Elliott, Dawn M; Mauck, Robert L; Chen, Weiliam; Malhotra, Neil R

2014-07-01

95

Three-dimensional hypoxic culture of human mesenchymal stem cells encapsulated in a photocurable, biodegradable polymer hydrogel: a potential injectable cellular product for nucleus pulposus regeneration.  

PubMed

Nucleus pulposus (NP) tissue damage can induce detrimental mechanical stresses and strains on the intervertebral disc, leading to disc degeneration. This study demonstrates the potential of a novel, photo-curable, injectable, synthetic polymer hydrogel (pHEMA-co-APMA grafted with polyamidoamine (PAA)) to encapsulate and differentiate human mesenchymal stem cells (hMSC) towards a NP phenotype under hypoxic conditions which could be used to restore NP tissue function and mechanical properties. Encapsulated hMSC cultured in media (hMSC and chondrogenic) displayed good cell viability up to day 14. The genotoxicity effects of ultraviolet (UV) on hMSC activity confirmed the acceptability of 2.5min of UV light exposure to cells. Cytotoxicity investigations revealed that hMSC cultured in media containing p(HEMA-co-APMA) grafted with PAA degradation product (10% and 20%v/v concentration) for 14days significantly decreased the initial hMSC adhesion ability and proliferation rate from 24hrs to day 14. Successful differentiation of encapsulated hMSC within hydrogels towards chondrogenesis was observed with elevated expression levels of aggrecan and collagen II when cultured in chondrogenic media under hypoxic conditions, in comparison with culture in hMSC media for 14days. Characterization of the mechanical properties revealed a significant decrease in stiffness and modulus values of cellular hydrogels in comparison with acellular hydrogels at both day 7 and day 14. These results demonstrate the potential use of an in vivo photo-curable injectable, synthetic hydrogel with encapsulated hMSC for application in the repair and regeneration of NP tissue. PMID:24793656

Kumar, Deepak; Gerges, Irini; Tamplenizza, Margherita; Lenardi, Cristina; Forsyth, Nicholas R; Liu, Yang

2014-08-01

96

Construction of collagen II\\/hyaluronate\\/chondroitin-6-sulfate tri-copolymer scaffold for nucleus pulposus tissue engineering and preliminary analysis of its physico-chemical properties and biocompatibility  

Microsoft Academic Search

To construct a novel scaffold for nucleus pulposus (NP) tissue engineering, The porous type II collagen (CII)\\/hyaluronate\\u000a (HyA)–chondroitin-6-sulfate (6-CS) scaffold was prepared using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS) cross-linking system. The physico-chemical properties and biocompatibility of CII\\/HyA–CS scaffolds\\u000a were evaluated. The results suggested CII\\/HyA–CS scaffolds have a highly porous structure (porosity: 94.8 ± 1.5%), high water-binding\\u000a capacity (79.2 ± 2.8%) and significantly improved mechanical

Chang-qing Li; Bo Huang; Gang Luo; Chuan-zhi Zhang; Ying Zhuang; Yue Zhou

2010-01-01

97

Proinflammatory Cytokine Expression Profile in Degenerated and Herniated Human Intervertebral Disc Tissues  

PubMed Central

Objective Prior reports document macrophage and lymphocyte infiltration with proinflammatory cytokine expression in pathologic intervertebral disc (IVD) tissues. Nevertheless, the role of the Th17 lymphocyte lineage in mediating disc disease remains uninvestigated. We undertook this study to evaluate the immunophenotype of pathologic IVD specimens, including interleukin-17 (IL-17) expression, from surgically obtained IVD tissue and from nondegenerated autopsy control tissue. Methods Surgical IVD tissues were procured from patients with degenerative disc disease (n = 25) or herniated IVDs (n = 12); nondegenerated autopsy control tissue was also obtained (n = 8) from the anulus fibrosus and nucleus pulposus regions. Immunohistochemistry was performed for cell surface antigens (CD68 for macrophages, CD4 for lymphocytes) and various cytokines, with differences in cellularity and target immunoreactivity scores analyzed between surgical tissue groups and between autopsy control tissue regions. Results Immunoreactivity for IL-4, IL-6, IL-12, and interferon-? (IFN?) was modest in surgical IVD tissue, although expression was higher in herniated IVD samples and virtually nonexistent in control samples. The Th17 lymphocyte product IL-17 was present in >70% of surgical tissue fields, and among control samples was detected rarely in anulus fibrosus regions and modestly in nucleus pulposus regions. Macrophages were prevalent in surgical tissues, particularly herniated IVD samples, and lymphocytes were expectedly scarce. Control tissue revealed lesser infiltration by macrophages and a near absence of lymphocytes. Conclusion Greater IFN? positivity, macrophage presence, and cellularity in herniated IVDs suggests a pattern of Th1 lymphocyte activation in this pathology. Remarkable pathologic IVD tissue expression of IL-17 is a novel finding that contrasts markedly with low levels of IL-17 in autopsy control tissue. These findings suggest involvement of Th17 lymphocytes in the pathomechanism of disc degeneration. PMID:20222111

Shamji, Mohammed F.; Setton, Lori A.; Jarvis, Wingrove; So, Stephen; Chen, Jun; Jing, Liufang; Bullock, Robert; Isaacs, Robert E.; Brown, Christopher; Richardson, William J.

2010-01-01

98

Smad3 Controls ?-1,3-Glucuronosyltransferase 1 Expression in Rat Nucleus Pulposus Cells: Implications of Dysregulated Expression in Disc Disease  

PubMed Central

Objective To study the regulation of expression of ?-1,3-glucuronosyltransferase 1 (GlcAT-1), an important regulator of glycosaminoglycan (GAG) synthesis, by Smad3 in nucleus pulposus (NP) cells. Methods GlcAT-1 expression was examined in rat NP and anulus fibrosus (AF) cells treated with transforming growth factor ? (TGF?). The effects of Smad signaling and Smad suppression on GlcAT-1 were examined in rat NP cells. GlcAT-1 expression was analyzed in the discs of Smad3-null mice and in degenerated human NP tissue. Results TGF? increased the expression of GlcAT-1 in rat NP but not rat AF cells. Suppression of GlcAT-1 promoter activity was evident with dominant-negative ALK-5 (DN-ALK-5). Cotransfection with Smad3 strongly induced promoter activity independent of TGF?. Bioinformatics analysis indicated the presence of several Smad binding sites in the promoter; deletion analysis showed that the region between ?274 and ?123 bp was required for Smad3 response. DN-Smad3, Smad 3 small interfering RNA, and Smad7 strongly suppressed basal as well as TGF?-induced promoter activity. Induction of promoter activity by Smad3 was significantly blocked by DN-Smad3; Smad7 had a very small effect. Lentiviral transduction of NP cells with short hairpin RNA Smad3 resulted in a decrease in GlcAT-1 expression and accumulation of GAG. Compared to wild-type mice, significantly lower expression of GlcAT-1 was seen in the discs of Smad3-null mice. Analysis of degenerated human NP tissue specimens showed no positive correlation between GlcAT-1 and TGF? expression. Moreover, isolated cells from degenerated human tissue showed a lack of induction of GlcAT-1 expression following TGF? treatment, suggesting an altered response. Conclusion Our findings demonstrate that in healthy NP cells, the TGF?–Smad3 axis serves as a regulator of GlcAT-1 expression. However, an altered responsiveness to TGF? during disc degeneration may compromise GAG synthesis. PMID:22674034

Wu, Qianghua; Wang, Jianru; Skubutyte, Renata; Kepler, Christopher K.; Huang, Zonggui; Anderson, D. Greg; Shapiro, Irving M.; Risbud, Makarand V.

2013-01-01

99

Review Article Effect of circumferential constraint on nucleus  

E-print Network

Review Article Effect of circumferential constraint on nucleus pulposus tissue in vitro Darla J could alter the mechanical forces imposed on the nucleus pulposus (NP) tissue. This could contribute,biochemicalcomposition,andmechanicalpropertiesofNPtissue. STUDY DESIGN: Nucleus pulposus cells were isolated from bovine caudal IVD and allowed to form tissue

Waldman, Stephen D.

100

Nucleus Implant Parameters Significantly Change the Compressive  

E-print Network

­6 . Nucleus replacement by a synthetic mate- rial or a tissue engineered structure may help to preserve the an.1115/1.1894369 Keywords: Lumbar Spine, Intervertebral Disc, Nucleus Pulposus, Hydrogel Nucleus Implant, Compressive the nucleus pulposus NP with the hydrogel im- plant. The hydrogel implant restored 88% of the compressive

Karduna, Andrew

101

Fluoroscopy assisted minimally invasive transplantation of allogenic mesenchymal stromal cells embedded in HyStem reduces the progression of nucleus pulposus degeneration in the damaged interverbal disc: a preliminary study in rabbits.  

PubMed

This study was conducted to develop a technique for minimally invasive and accurate delivery of stem cells to augment nucleus pulposus (NP) in damaged intervertebral discs (IVD). IVD damage was created in noncontiguous discs at L4-L5 level; rabbits (N = 12) were randomly divided into three groups: group I treated with MSCs in HyStem hydrogel, group II treated with HyStem alone, and group III received no intervention. MSCs and hydrogel were administered to the damaged disc under guidance of fluoroscopy. Augmentation of NP was assessed through histological and MRI T2 mapping of the NP after eight weeks of transplantation. T2 weighted signal intensity was higher in group I than in groups II and III (P < 0.05). Disc height index showed maximum disc height in group I compared to groups II and III. Histological score of the degenerative index was significantly (P < 0.05) lower in group I (8.6 ± 1.8) than that in groups II (11.6 ± 2.3) and III (18.0 ± 5.7). Immunohistochemistry staining for collagen type II and aggrecan staining were higher in group I as compared to other groups. Our results demonstrate that the minimally invasive administration of MSCs in hyaluronan hydrogel (HyStem) augments the repair of NP in damaged IVD. PMID:24983002

Subhan, Rifa Aquidah; Puvanan, Karunanithi; Murali, Malliga Raman; Raghavendran, Hanumantha Rao Balaji; Shani, Samuel; Abdullah, Basri Johan Jeet; Abbas, Azlina Amir; Mohamed, Jamal Azmi; Kamarul, Tunku

2014-01-01

102

Cytotoxic Effects of the Radiocontrast Agent Iotrolan and Anesthetic Agents Bupivacaine and Lidocaine in Three-Dimensional Cultures of Human Intervertebral Disc Nucleus Pulposus Cells: Identification of the Apoptotic Pathways  

PubMed Central

Background Discography and discoblock are imaging procedures used to diagnose discogenic low back pain. Although needle puncture of the intervertebral disc (IVD) itself induces disc degeneration, the agents used in these procedures may also have harmful effects on IVD cells. The purpose of this study was to analyze whether radiocontrast agents and local anesthetic agents have detrimental effects on human nucleus pulposus (NP) cells. Methods Healthy human NP cells were cultured for 7 days in three-dimensional (3D) cell–alginate bead composites, and were then exposed to clinically relevant doses of a radiocontrast agent (iotrolan) or local anesthetic (lidocaine or bupivacaine). Cell viability and apoptosis were measured by confocal microscopy and flow cytometry. On the basis of caspase expression profiles, the apoptotic pathways activated by the agents were identified by Western blot analysis. Results The radiocontrast agent iotrolan did not affect NP cell viability or induce apoptosis. In contrast, both the anesthetic agents significantly decreased cell viability and increased the apoptotic cell number in a time- and dose-dependent manner. After 120 min, 2% lidocaine and 0.5% bupivacaine decreased percent live cells to 13% and 10%, respectively (p<0.05). The number of apoptotic cells was doubled by increasing lidocaine dosage from 1% to 2% (23% and 42%) and bupivacaine from 0.25% to 0.50% (25% and 48%) (p<0.05). Western blot analysis revealed that both anesthetic agents upregulated cleaved caspase-3 and caspase-8, whereas only bupivacaine upregulated cleaved caspase-9. Conclusions/Significance The present study demonstrates that iotrolan does not affect the viability of healthy human NP cells. In contrast, the two anesthetic agents commonly used in discography or discoblock may cause extensive damage to IVDs by inducing apoptotic cell death. PMID:24642945

Iwasaki, Koji; Sudo, Hideki; Yamada, Katsuhisa; Ito, Manabu; Iwasaki, Norimasa

2014-01-01

103

Xylosyltransferase-1 Expression Is Refractory to Inhibition by the Inflammatory Cytokines Tumor Necrosis Factor ? and IL-1? in Nucleus Pulposus Cells: Novel Regulation by AP-1, Sp1, and Sp3.  

PubMed

We investigated whether expression of xylosyltransferase-1 (XT-1), a key enzyme in glycosaminoglycan biosynthesis, is responsive to disk degeneration and to inhibition by the inflammatory cytokines tumor necrosis factor ? and IL-1? in nucleus pulposus (NP) cells. Analysis of human NP tissues showed that XT-1 expression is unaffected by degeneration severity; XT-1 and Jun, Fos, and Sp1 mRNA were positively correlated. Cytokines failed to inhibit XT-1 promoter activity and expression. However, cytokines decreased activity of XT-1 promoters containing deletion and mutation of the -730/-723 bp AP-1 motif, prompting us to investigate the role of AP-1 and Sp1/Sp3 in the regulation of XT-1 in healthy NP cells. Overexpression and suppression of AP-1 modulated XT-1 promoter activity. Likewise, treatment with the Sp1 inhibitors WP631 and mithramycin A or cotransfection with the plasmid DN-Sp1 decreased XT-1 promoter activity. Inhibitors of AP-1 and Sp1 and stable knockdown of Sp1 and Sp3 resulted in decreased XT-1 expression in NP cells. Genomic chromatin immunoprecipitation analysis showed AP-1 binding to motifs located at -730/-723 bp and -684/-677 bp and Sp1 binding to -227/-217 bp and -124/-114 bp in XT-1 promoter. These results suggest that XT-1 expression is refractory to the disease process and to inhibition by inflammatory cytokines and that signaling through AP-1, Sp1, and Sp3 is important in the maintenance of XT-1 levels in NP cells. PMID:25476526

Ye, Wei; Zhou, Jie; Markova, Dessislava Z; Tian, Ye; Li, Jun; Anderson, D Greg; Shapiro, Irving M; Risbud, Makarand V

2015-02-01

104

A History of Lumbar Disc Herniation From Hippocrates to the 1990s.  

PubMed

In ancient times, a supernatural understanding of the syndrome of lumbar radiculopathy often involved demonic forces vexing the individual with often crippling pain. The ancient Greeks and Egyptians began to take a more naturalistic view and, critically, suspected a relationship between lumbar spinal pathology and leg symptoms. Relatively little then changed for those with sciatica until the classic works by Cotugno and Kocher arrived in the late 18th century. Early lumbar canal explorations were performed in the late 1800s and early 1900s by MacEwen, Horsley, Krause, Taylor, Dandy, and Cushing, among others. In these cases, when compressive pathologies were found and removed, the lesions typically were (mis-)identified as enchondromas or osteochondritis dissecans. To better understand the history, learn more about the first treatments of lumbar disc herniation, and evaluate the impact of the early influences on modern spine practice, searches of PubMed and Embase were performed using the search terms discectomy, medical history, lumbar spine surgery, herniated disc, herniated nucleus pulposus, sciatica, and lumbar radiculopathy. Additional sources were identified from the reference lists of the reviewed papers. Many older and ancient sources including De Ischiade Nervosa are available in English translations and were used. When full texts were not available, English abstracts were used. The first true, intentional discectomy surgery was performed by Mixter and Barr in 1932. Early on, a transdural approach was favored. In 1938, Love described the intralaminar, extradural approach. His technique, although modified with improved lighting, magnification, and retractors, remains a staple approach to disc herniations today. Other modalities such as chymopapain have been investigated. Some remain a part of the therapeutic armamentarium, whereas others have disappeared. By the 1970s, CT scanning after myelography markedly improved the clinical evaluation of patients with lumbar disc herniation. In this era, use of discectomy surgery increased rapidly. Even patients with very early symptoms were offered surgery. Later work, especially by Weber and Hakelius, showed that many patients with lumbar disc herniation would improve without surgical intervention. In the ensuing decades, the debate over operative indications and timing continued, reaching another pivotal moment with the 2006 publication of the initial results of Spine Patient Outcomes Research Trial. PMID:24752913

Truumees, Eeric

2014-04-22

105

Herniated Disk  

MedlinePLUS

... the jelly-like center of the disk to leak, irritating the nearby nerves. This can cause sciatica or back pain. Your doctor will diagnose a herniated disk with a physical exam and, sometimes, imaging tests. With treatment, most people recover. Treatments include rest, ...

106

Stem cell regeneration of the nucleus pulposus  

Microsoft Academic Search

Low back pain due to disc degeneration is one of the largest health problems faced in this nation when judged by lost work time and direct as well as indirect costs. Many experimental methods are being explored to treat or to reverse the effect of disc degeneration. This article reviews the strategy of a tissue engineering approach to disc regeneration.

Makarand V. Risbud; Irving M. Shapiro; Alexander R. Vaccaro; Todd J. Albert

2004-01-01

107

The clinical study of percutaneous disc decompression of treating herniation of cervical disc with Nd:YAG laser  

NASA Astrophysics Data System (ADS)

Objective: The possibility of PLDD (percutaneous laser disc decompression) and an ideal non-operative method which is long everlasting effect for PLDD was investigated. Methods: 159 patients of Cervical Disc Herniation with PLDD were studied. All the herniated discs were irradiated with 10­15J/S Nd:YAG laser quantum through optical-fiber under the supervision of C-arm X-ray. Results: All the patients were followed and reexamined CT or MRI after one to six months of PLDD. The result of cured (67.92%), excellent (24.53%), moderation (5.66%), non-effect (1.88%) was got. The excellent rate was 88.24%. The effective rate was 97.65%. Non-effective rate was 2.35%. Conclusion: When irradiated with Nd:YAG laser, the nucleus pulposus was vapouring, charring and coagulating. The volume and inner-pressure of the disc decreased. So the symptoms and signs improved. The main value of this methods were micro-damage, non-operation, no bleeding, no bone injury, good therapy effect, quick recovery, lesser pain, safety and excellent long everlasting effect. It is an ideal non-operative method of treating PLDD.

Zhang, Dianxue; Cheng, Hefu; Wang, Jindong

2005-07-01

108

Schmorl's nodes (intravertebral herniations of intervertebral disc tissue) in two historic British populations.  

PubMed Central

The herniation of the nucleus pulposus into the vertebral body produces ectopic deposit of disc material which are known as Schmorl's nodes. This prolapsed disc tissue leaves characteristic deformations on the surface of the vertebral body and hence the incidence of this lesion can be studied in skeletal remains. This report describes the occurrence of Schmorl's nodes in TV8-SV1 in two historic adult British populations, one from Aberdeen and the other from London. In the Aberdeen group, both males and females showed a high incidence rate and severity of Schmorl's nodes. In the London group, the males had a similarly high affliction whereas the females were nearly free of the condition. The lesion had no significant predilection for any one particular vertebral surface. However, in males in both localities, the frequency of Schmorl's nodes was significantly higher in the thoracic region than in the lumbosacral region. In contrast, both groups of females showed similar node frequency in these two zones. The majority of Schmorl's nodes were localised in the central and central-posterior regions of the vertebral surface. When nodes occurred on successive vertebral surfaces, they often formed sequences showing similar shape and position. The aetiology of Schmorl's nodes is unclear. Various hypothetical causal factors were appraised in relation to the findings of this study. It was suggested that anomalies in vascular and/or notochordal regression may be related to the development of the lesion. Images Fig. 2 Fig. 6 PMID:3323152

Saluja, G; Fitzpatrick, K; Bruce, M; Cross, J

1986-01-01

109

The Effect of Nucleus Implant Parameters on the Compressive Mechanics of the Lumbar Intervertebral Disc: A Finite  

E-print Network

Nucleus replacement by a polymeric material and by tissue engineering approaches are currently being tissues.17 The central core, the nucleus pulposus, is sur- rounded by the outer annulus fibrosus intervertebral disc was utilized for understanding nucleus pulposus implant mechanics. The model was used

Karduna, Andrew

110

Herniated Lumbar Disc  

MedlinePLUS

... 50. A herniated lumbar disc may also cause back pain, although back pain alone (without leg pain) can have many causes ... 90% success); surgery is less effective in relieving back pain. Nonsurgical treatment Your doctor may prescribe nonsurgical treatments ...

111

Percutaneous treatment of intervertebral disc herniation.  

PubMed

Interventional radiology plays a major role in the management of symptomatic intervertebral disc herniations. In the absence of significant pain relief with conservative treatment including oral pain killers and anti-inflammatory drugs, selective image-guided periradicular infiltrations are generally indicated. The precise control of needle positioning allows optimal distribution of steroids along the painful nerve root. After 6 weeks of failure of conservative treatment including periradicular infiltration, treatment aiming to decompress or remove the herniation is considered. Conventional open surgery offers suboptimal results and is associated with significant morbidity. To achieve minimally invasive discal decompression, different percutaneous techniques have been developed. Their principle is to remove a small volume of nucleus, which results in an important reduction of intradiscal pressure and subsequently reduction of pressure inside the disc herniation. However, only contained disc herniations determined by computed tomography or magnetic resonance are indicated for these techniques. Thermal techniques such as radiofrequency or laser nucleotomy seem to be more effective than purely mechanical nucleotomy; indeed, they achieve discal decompression but also thermal destruction of intradiscal nociceptors, which may play a major role in the physiopathology of discal pain. The techniques of image-guided spinal periradicular infiltration and percutaneous nucleotomy with laser and radiofrequency are presented with emphasis on their best indications. PMID:21629404

Buy, Xavier; Gangi, Afshin

2010-06-01

112

Cytokine expression in the epidural space: a model of non-compressive disc herniation-induced inflammation  

PubMed Central

Study Design Animal study Objective Development of an animal model for the study of biochemical changes that occur in the epidural space after intervertebral disc herniation. Summary of Background Data Although strong evidence for an inflammatory component exists, the biochemical processes underlying pain following disc herniation remain unknown. Methods Epidural lavage was performed in 48 rats after L5 dorsal root ganglion (DRG) exposure at baseline and 3, 6, or 24 hours after placement of autologous nucleus pulposus (NP) (N = 15), saline (N = 15), or NP + an interferon-gamma antibody (anti-IFN?; N = 18) directly onto the DRG. Multiplex assays quantifying interleukin (IL-)-1-?, IL-1?, IL-2, IL-4, IL-6, IL-10, TNF?, IFN? and GM-CSF were performed. NP (N = 7) was also analyzed for these cytokines by placing NP into saline and measuring the relative concentration. Results Cytokines measured low at baseline (0–100pg/ml) in all groups. Compared to saline, NP application caused IL-6 elevation, peaking at T=3hr, that was prevented by anti-IFN?. NP induced elevation of TNF?, peaking at T=24hr and was prevented by anti-IFN?. IFN? was elevated after NP at T=3hr and T=24hr. IL-1? was similar after saline versus NP. The concentrations of IL-1? and IL-10 were elevated at T=3hr, 6hr and 24hr in all groups without between-groups difference. The level of IL-4 peaked at T=3hr in the NP group and was different than saline and NP +anti-IFN? groups but the time effect was insignificant. There was no change for GM-CSF. The concentration of cytokines measured in normal NP was < 2pg/ml for all cytokines except TNF?. Conclusion In this model of acute non-compressive disc herniation, NP caused the elevation of epidural IL-6, TNF? and IFN?; all attenuated by IFN? blockade. IL-1? and IL-10 were both significantly elevated by saline alone and their response was not prevented by IFN? blockade. This model may prove useful for the study of the biochemical processes by which NP induces inflammation-induced nerve root irritation and radiculopathic pain. PMID:22648034

Cuellar, Jason M.; Borges, Paula M.; Cuéllar, Vanessa Gabrovsky; Yoo, Andrew; Scuderi, Gaetano J.; Yeomans, David C.

2012-01-01

113

Herniated Cervical Disc  

MedlinePLUS

... may be recommended if you have severe arm pain. These are injections of corticosteroid into the epidural space (the area ... muscles along the spine. While occasionally useful for pain control, trigger point injections do not help heal a herniated cervical disc. ...

114

Asymptomatic Transhiatal Pancreatic Herniation after Oesophagectomy  

PubMed Central

Transhiatal herniation of abdominal organs after oesophageal resection and reconstruction is rare and sparsely described in the literature. The commonest organ to herniate is the colon. Pancreatic herniation has been reported twice before. We report a case of postoesophagectomy transhiatal pancreatic herniation in an asymptomatic patient. PMID:25478403

Pal, Sujoy; Dash, Nihar Ranjan; Madhusudhan, KS; Srivastava, Deep Narayan

2014-01-01

115

Paraduodenal herniation: An internal herniation in a virgin abdomen  

PubMed Central

INTRODUCTION A paraduodenal hernia is an uncommon hernia that results from an abnormal rotation of the midgut. Commonly, these hernias are congenital in nature, and are reported to cause 1.5–5.8% of intestinal obstructions. These hernias occur when a part of the jejunum herniates through the posterior portion of the ligament of Treitz. Diagnosing these hernias preoperatively has been shown to be difficult, despite the studies that are available. Early diagnosis is imperative to the patient in order to avoid strangulation of the bowel, which is associated with a high mortality. PRESENTATION OF CASE In this case, we present a case of a left-sided paraduodenal hernia in a virgin abdomen in a 38-year-old African American male with a herniation of a loop of jejunum through a defect of the posterior portion of the ligament of Treitz. The patient also had a volvulized segment of the proximal jejunum, and part of this bowel was found to be ischemic. DISCUSSION Acute intestinal obstruction caused by a left paraduodenal hernia is a rare cause of intestinal obstruction. A literary search of PubMed between 1980 and 2012 indicated only 44 cases of intestinal obstruction secondary to a left paraduodenal hernia. CONCLUSION The patient underwent exploratory laparotomy, and the herniated bowel was found to be ischemic. The hernia was reduced, and the ischemic bowel resected. The defect was closed, and the patient had a non-complicated recovery. PMID:25437660

Kabbani, Dana; Salem, Ayman; Holloway, Daniel K.

2014-01-01

116

[A case of paraesophageal omental herniation].  

PubMed

A 48-year-old woman underwent routine chest roentgenography and a mass shadow was seen in the posterior mediastinum. CT, MRI and celiac arteriography were performed, and paraesophageal omental herniation was diagnosed. Paraesophageal omental herniation is uncommon, and there have been no reports cases with complications. Therefore, this case is being followed-up carefully. PMID:9611979

Saijo, Y; Honda, H; Nishigaki, Y; Noro, T

1998-01-01

117

[Spontaneous regression of symptomatic lumbar disc herniation].  

PubMed

Lumbar disc herniation is very common, sometimes leading to disability of the patient, and in a significant number of cases can only be solved with surgery. This paper reports a case with a large symptomatic disc herniation, which suffered spontaneous regression, and no surgery was necessary. The case is documented on serial MRI, consistent with the clinical improvement of the patient. PMID:22472931

Ribeiro, R Pimenta; Matos, R Milheiro; Vieira, A; Costa, J M; Proença, R; Pinto, R

2011-01-01

118

Assessing the Effect of Spaceflight on the Propensity for Astronauts to Develop Disk Herniation  

NASA Technical Reports Server (NTRS)

BACKGROUND: A previous study [1] reported that the instantaneous risk of developing a Herniated Nucleus Pulposus (HNP) was higher in astronauts who had flown at least one mission, as compared with those in the corps who had not yet flown. However, the study only analyzed time to HNP after the first mission (if any) and did not account for the possible effects of multiple missions. While many HNP's occurred well into astronauts' careers or in some cases years after retirement, the higher incidence of HNPs relatively soon after completion of space missions appears to indicate that spaceflight may lead to an increased risk of HNP. The purpose of this study was to support the Human System Risk Board assessment of back pain, evaluate the risk of injury due to dynamic loads, and update the previous dataset which contained events up to December 31, 2006. METHODS: Data was queried from the electronic medical record and provided by the Lifetime Surveillance of Astronaut Health. The data included all 330 United States astronauts from 1959 through February 2014. Cases were confirmed by Magnetic Resonance Imaging, Computerized Tomography, Myelography, operative findings, or through clinical confirmation with a neurologist or neurosurgeon. In this analysis, astronauts who had an HNP at selection into the corps or had an HNP diagnosis prior to their first flight were excluded. The statistical challenges in using the available data to separate effects of spaceflight from those associated with general astronaut training and lifestyle on propensity to develop HNPs are many. The primary outcome is reported date of first HNP (if any), which at best is only an approximation to the actual time of occurrence. To properly analyze this data with a survival analysis model, one must also know the "exposure" time - i.e. how long each astronaut has been at risk for developing an HNP. If an HNP is reported soon after a mission, is it mission caused or general? If the former, exposure time should be counted from the time of landing (assuming the risk of HNP occurring during a mission is zero). If the latter, exposure time should be counted from the time of selection; however we can't directly know which one to use. In our analysis we take both of these possibilities into account with a competing risks model, wherein two distinct stochastic processes are going on: TG = time to HNP (general) and TS = time to HNP (spaceflight). Under this type of model, whichever of these occurs first is what we observe; in other words we don't observe TG or TS, only min(TG, TS). Here, we parameterized the model in terms of separate Weibull hazard functions for each process and estimated all parameters using maximum likelihood. In addition, we allowed for a "cured fraction" - i.e. the possibility that some astronauts may never develop an HNP. RESULTS: Results will include a depiction of the competing hazard functions as well as a probability curve for the relative likelihood that an HNP reported at a given time after a mission is actually mission caused. Other factors, such as dwell time in microgravity and vehicle landing environment will be explored. An overall assessment as to whether spaceflight truly exacerbates HNP risk will be made.

Feiveson, A. H.; Mendez, C. M.; Somers, J. T.

2014-01-01

119

Spinal Neurofibroma Masquerading as a Herniated Disc  

PubMed Central

We present the only case in English medical literature of a spinal neurofibroma misdiagnosed as a herniated disc using magnetic resonance imaging (MRI). This case presented with typical symptoms and radiological findings of a herniated disc. Intraoperatively, an abnormality was noted at the S1 nerve root sleeve. Further exploration revealed a spinal neurofibroma which was completely resected, resulting in an improvement in the patient’s symptoms. Currently, there is heavy reliance on MRI as a highly sensitive and specific tool used in the diagnosis of herniated lumbar discs. Although there have been occasional reports of misdiagnoses using MRI, there are no reported cases of a spinal neurofibroma being misdiagnosed as a herniated lumbar disc. Despite great advances in radiological diagnostic imaging, surgical surprises do still occur. Ultimately, instinct is still essential in intraoperative surgical decisions. PMID:23275853

Lamki, Tariq; Ammirati, Mario

2012-01-01

120

Spontaneous cervical intradural disc herniation.  

PubMed

Cervical intradural disc herniation (IDH) is a rare condition with very few case reports in the literature. We report a 64-year-old man who presented with sudden onset neck pain and rapidly progressing weakness in the left upper and lower limb. There was no history of trauma. MRI of the cervical spine showed a C6-C7 disc prolapse, for which he underwent a C6-C7 discectomy and fusion with bone graft through an anterior cervical approach. To our knowledge, all patients with a cervical IDH reported in the literature have a traumatic etiology. To the best of our knowledge, we report the first patient with a spontaneous cervical IDH. PMID:24210799

Warade, Abhijit G; Misra, Basant K

2014-05-01

121

Herniated pancreatic body within a paraesophageal hernia  

PubMed Central

A hiatal hernia can be classified as one of four types according to the position of the gastroesophageal (GE) junction and the extent of herniated stomach. Type I, or sliding hernias, account for up to 95% of all hiatal hernias and occur when the GE junction migrates into the posterior mediastinum through the hiatus. Type II occurs when the fundus herniates through the hiatus alongside a normally positioned GE junction. Type III is a combination of types I and II hernias with a displaced GE junction as well as stomach protruding through the hiatus. Type IV paraesophageal hernias are the rarest of the hiatal hernias. Usually, colon or small bowel is herniated within the mediastinum along with the stomach. We present a case of a paraesophageal hernia with the mid-body of the pancreas as part of the hernia contents. PMID:21394323

Coughlin, Megan; Fanous, Medhat; Velanovich, Vic

2011-01-01

122

Paraplegia due to thoracic disc herniation.  

PubMed

Disc herniation at the thoracic the spine level is more common than generally thought. Localisation of pain may be vague and may erroneously point to cardiopulmonary, gastrointestinal, genito-urinary or even psychiatric disease. Magnetic resonance imaging is the investigation of choice, especially if spinal cord compression is suspected. PMID:9338030

Pal, B; Johnson, A

1997-07-01

123

SIRT1 protects against apoptosis by promoting autophagy in degenerative human disc nucleus pulposus cells  

PubMed Central

SIRT1 could protect degenerative human NP cells against apoptosis, and there were extensive and intimate connection between apoptosis and autophagy. Up to now, the role of autophagy in the process of human IVD degeneration is unclear. We sought to explore the relationship between autophagy and human IVD degeneration and to understand whether autophagy is involved in the protective effect of SIRT1 against apoptosis in NP cells. Our results showed that the autophagosomes number, the mRNA level of LC3 and Beclin-1, the protein expression of LC3-II/I and Beclin-1, decreased in NP from DDD. Resveratrol could increase the protein expression of LC3-II/I and Beclin-1, and reduce apoptosis in degenerative NP cells. In contrast, the protein levels of LC3-II/I and Beclin-1 were down-regulated and apoptosis level was significantly up-regulated in treatment with nicotinamide or SIRT1-siRNA transfection. Further analysis identified that the expression of cleaved Caspase3 and apoptosis incidence significantly increased with the pretreatment of bafilomycin A, whether resveratrol was added or not. These suggested that autophagy may play an important role in IVD degeneration, and SIRT1 protected degenerative human NP cells against apoptosis via promoting autophagy. These findings would aid in the development of novel therapeutic approaches for degenerative disc disease treatment. PMID:25503852

Jiang, Wei; Zhang, Xuemei; Hao, Jie; Shen, Jieliang; Fang, Ji; Dong, Wen; Wang, Dawu; Zhang, Xiaojun; Shui, Wei; Luo, Yi; Lin, Liangbo; Qiu, Quanhe; Liu, Bin; Hu, Zhenming

2014-01-01

124

SIRT1 protects against apoptosis by promoting autophagy in degenerative human disc nucleus pulposus cells.  

PubMed

SIRT1 could protect degenerative human NP cells against apoptosis, and there were extensive and intimate connection between apoptosis and autophagy. Up to now, the role of autophagy in the process of human IVD degeneration is unclear. We sought to explore the relationship between autophagy and human IVD degeneration and to understand whether autophagy is involved in the protective effect of SIRT1 against apoptosis in NP cells. Our results showed that the autophagosomes number, the mRNA level of LC3 and Beclin-1, the protein expression of LC3-II/I and Beclin-1, decreased in NP from DDD. Resveratrol could increase the protein expression of LC3-II/I and Beclin-1, and reduce apoptosis in degenerative NP cells. In contrast, the protein levels of LC3-II/I and Beclin-1 were down-regulated and apoptosis level was significantly up-regulated in treatment with nicotinamide or SIRT1-siRNA transfection. Further analysis identified that the expression of cleaved Caspase3 and apoptosis incidence significantly increased with the pretreatment of bafilomycin A, whether resveratrol was added or not. These suggested that autophagy may play an important role in IVD degeneration, and SIRT1 protected degenerative human NP cells against apoptosis via promoting autophagy. These findings would aid in the development of novel therapeutic approaches for degenerative disc disease treatment. PMID:25503852

Jiang, Wei; Zhang, Xuemei; Hao, Jie; Shen, Jieliang; Fang, Ji; Dong, Wen; Wang, Dawu; Zhang, Xiaojun; Shui, Wei; Luo, Yi; Lin, Liangbo; Qiu, Quanhe; Liu, Bin; Hu, Zhenming

2014-01-01

125

Characterization of novel photocrosslinked carboxymethylcellulose hydrogels for encapsulation of nucleus pulposus cells  

Microsoft Academic Search

Back pain is a significant clinical concern often associated with degeneration of the intervertebral disc (IVD). Tissue engineering strategies may provide a viable IVD replacement therapy; however, an ideal biomaterial scaffold has yet to be identified. One candidate material is carboxymethylcellulose (CMC), a water-soluble derivative of cellulose. In this study, 90 and 250kDa CMC polymers were modified with functional methacrylate

Anna T. Reza; Steven B. Nicoll

2010-01-01

126

Biologic Response of Degenerative Living Human Nucleus Pulposus Cells to Treatment with Cytokines  

PubMed Central

Purpose To investigate the molecular responses of various genes and proteins related to disc degeneration upon treatment with cytokines that affect disc-cell proliferation and phenotype in living human intervertebral discs (IVDs). Responsiveness to these cytokines according to the degree of disc degeneration was also evaluated. Materials and Methods The disc specimens were classified into two groups: group 1 (6 patients) showed mild degeneration of IVDs and group 2 (6 patients) exhibited severe degeneration of IVDs. Gene expression was analyzed after treatment with four cytokines: recombinant human bone morphogenic protein (rhBMP-2), transforming growth factor-? (TGF-?), interleukin-1? (IL-1?), and tumor necrosis factor-? (TNF-?). Molecular responses were assessed after exposure of cells from the IVD specimens to these cytokines via real-time polymerase chain reaction and immunofluorescence staining. Results mRNA gene expression was significantly greater for aggrecan, type I collagen, type II collagen, alkaline phosphatase, osteocalcin, and Sox9 in group 1 than mRNA gene expression in group 2, when the samples were not treated with cytokines. Analysis of mRNA levels for these molecules after morphogen treatment revealed significant increases in both groups, which were much higher in group 1 than in group 2. The average number of IVD cells that were immunofluorescence stained positive for alkaline phosphatase increased after treatment with rhBMP-2 and TGF-? in group 1. Conclusion The biologic responsiveness to treatment of rhBMP-2, TGF-?, TNF-?, and IL-1? in the degenerative living human IVD can be different according to the degree of degeneration of the IVD. PMID:25510775

Kim, Sang Hyun; Kim, Keung Nyun; Park, Jeong Yoon; Cho, Ki Hong; Chin, Dong Kyu; Kim, Keun Su; Cho, Yong Eun

2015-01-01

127

Herniation through the foramen of Winslow presenting as obstructive jaundice.  

PubMed

Herniation through the foramen of Winslow is a rare variety of paraduodenal hernia. We report a 19-month-old child with obstructive jaundice due to midgut herniation through the foramen of Winslow with associated volvulus. The herniation and volvulus were precipitated by intestinal malrotation. The patient underwent extraamniotic silo repair of exomphalos major in the neonatal period. Investigation for malrotation is recommended after extraamniotic closure of exomphalos. PMID:15902477

Antao, B; Hamill, J; Samuel, M; Hiorns, M; Pierro, A

2005-07-01

128

Cecal bascule herniation into the lesser sac  

PubMed Central

Cecal bascule is a rare cause of bowel obstruction in which a mobile cecum folds anteriorly and superiorly over the ascending colon. Herein, we present the first case of internal herniation of a cecal bascule into the lesser sac through the foramen of winslow, aiming at discussing radiological findings, differential diagnosis, and surgical management of this uncommon condition. A 75-year-old female presented to the emergency room with an 18-h history of sudden onset sharp, progressively worsening abdominal pain associated with vomiting. Physical exam revealed abdominal distention and epigastric tenderness while initial laboratory tests were unremarkable. Computed tomography of her abdomen and pelvis showed a loop of distended colon within lesser sac without signs of bowel ischemia or perforation. On exploratory laparotomy, a cecal bascule was found herniating into lesser sac via foramen of winslow. Upon reduction, the cecum appeared viable therefore a cecopexy was performed without bowel resection. Unlike cecal volvulus, cecal bascule consists of no axial rotation of the bowel with no mesenteric vascular compromise and therefore ischemia would only occur from intraluminal tension or extraluminal compression from the borders of foramen of winslow. The management of internal herniation of a cecal bascule is always surgical including anatomic resection or cecopexy. PMID:25516868

Makarawo, Tafadzwa; Macedo, Francisco Igor; Jacobs, Michael J

2014-01-01

129

Cecal bascule herniation into the lesser sac.  

PubMed

Cecal bascule is a rare cause of bowel obstruction in which a mobile cecum folds anteriorly and superiorly over the ascending colon. Herein, we present the first case of internal herniation of a cecal bascule into the lesser sac through the foramen of winslow, aiming at discussing radiological findings, differential diagnosis, and surgical management of this uncommon condition. A 75-year-old female presented to the emergency room with an 18-h history of sudden onset sharp, progressively worsening abdominal pain associated with vomiting. Physical exam revealed abdominal distention and epigastric tenderness while initial laboratory tests were unremarkable. Computed tomography of her abdomen and pelvis showed a loop of distended colon within lesser sac without signs of bowel ischemia or perforation. On exploratory laparotomy, a cecal bascule was found herniating into lesser sac via foramen of winslow. Upon reduction, the cecum appeared viable therefore a cecopexy was performed without bowel resection. Unlike cecal volvulus, cecal bascule consists of no axial rotation of the bowel with no mesenteric vascular compromise and therefore ischemia would only occur from intraluminal tension or extraluminal compression from the borders of foramen of winslow. The management of internal herniation of a cecal bascule is always surgical including anatomic resection or cecopexy. PMID:25516868

Makarawo, Tafadzwa; Macedo, Francisco Igor; Jacobs, Michael J

2014-12-16

130

Inguinal herniation of the bladder in an infant.  

PubMed

Inguinal herniation of the bladder is an uncommon finding with fewer than 200 cases reported in the literature. It is found most commonly in older, obese men with lower urinary tract symptoms. We report a case of inguinal herniation of the bladder in a premature infant. PMID:16672120

Manatt, Scott; Campbell, Jeffrey B; Ramji, Faridali; Kuhn, Ann; Frimberger, Dominic

2006-04-01

131

Nucleus implantation: the biomechanics of augmentation versus replacement with varying degrees of nucleotomy.  

PubMed

Nucleus pulposus replacement and augmentation has been proposed to restore disk mechanics in early stages of degeneration with the option of providing a minimally invasive procedure for pain relief to patients with an earlier stage of degeneration. The goal of this paper is to examine compressive stability of the intervertebral disk after either partial nucleus replacement or nuclear augmentation in the absence of denucleation. Thirteen human cadaver lumbar anterior column units were used to study the effects of denucleation and augmentation on the compressive mechanical behavior of the human intervertebral disk. Testing was performed in axial compression after incremental steps of partial denucleation and subsequent implantation of a synthetic hydrogel nucleus replacement. In a separate set of experiments, the disks were not denucleated but augmented with the same synthetic hydrogel nucleus replacement. Neutral zone, range of motion, and stiffness were measured. The results showed that compressive stabilization of the disk can be re-established with nucleus replacement even for partial denucleation. Augmentation of the disk resulted in an increase in disk height and intradiskal pressure that were linearly related to the volume of polymer implanted. Intervertebral disk instability, evidenced by increased neutral zone and ranges of motion, associated with degeneration can be restored by volume filling of the nucleus pulposus using the hydrogel device presented here. PMID:24599572

Cannella, Marco; Isaacs, Jessica L; Allen, Shanee; Orana, Argjenta; Vresilovic, Edward; Marcolongo, Michele

2014-05-01

132

Migratory intradural disk herniation and a strategy for intraoperative localization.  

PubMed

Study Design?Case report. Objective?Describe a case of intradural disk herniation and a method for intraoperative localization. Methods?Intradural disk herniations are uncommon but well described. The diagnosis of these lesions is often difficult, and sometimes they may be diagnosed only through an intradural exploration after an expected disk fragment cannot be located. We report the case of an intradural disk herniation with an additional diagnostic difficulty-a migrated intradural disk. Results?We present the first intraoperative imaging evidence of disk migration and propose a strategy to locate intradural disk fragments prior to durotomy. Conclusion?Intradural disk herniations should be suspected when intraoperative findings are not congruent with imaging findings. An intraoperative myelogram may be helpful. PMID:25648315

Daffner, Scott D; Sedney, Cara L; Rosen, Charles L

2015-02-01

133

Thoracic Disc Herniation Presenting with Transient Anterior Spinal Artery Syndrome  

PubMed Central

Summary This report is a clinical and radiologic correlation of anterior spinal arterial distribution ischemia with a thoracic disc herniation affecting the artery of Adamkiewicz. We could only find one other similar reported case. A 38-year-old woman developed sudden onset of severe back pain and radiculopathy, followed by rapidly evolving paraparesis. The neurological examination was consistent with a deficit caused by anterior spinal artery ischemia. MRI revealed T2 signal change in the thoracolumbar spinal cord and a laterally placed, non-calcified disc herniation. Selective spinal angiography performed 30 hours after onset revealed displacement of the left T9 radicular feeding artery by the disc herniation; at this time the artery was patent. The patient experienced some resolution of symptoms within the first 24 hours and was managed conservatively and made a significant recovery within two weeks. Appropriately located thoracic disc herniations can disturb the blood supply to the thoracolumbar spinal cord. PMID:20667212

Guest, J.D.; Griesdale, D.E.; Marotta, T.

2000-01-01

134

Intrathoracic omental herniation through the esophageal hiatus: a case report.  

PubMed

A case of paraesophageal omental herniation in a 74-year-old man is reported. Although computed tomography (CT) and magnetic resonance imaging (MRI) depicted a retrocardiac fatty mass that resembled omental herniation, residual concern remained regarding lipomatous tumor. Angiography provided decisive evidence of a mass containing omental vessels passing through the esophageal hiatus, which led to the final diagnosis. The patient underwent a strict course of observation, because he had no symptoms or abnormal physical or laboratory findings. Paraesophageal omental herniation mimics lipomatous tumors, such as lipoma or well-differentiated liposarcoma, extending to both sides of the diaphragm. Correct diagnosis of omental herniation requires the evidence of omental fat accompanied with omental vessels passing through the esophageal hiatus. Since angiography is an invasive diagnostic procedure, we would recommend dynamic MRI or reconstructed 3D MR angiography as alternatives to angiography. PMID:11837582

Kubota, K; Ohara, S; Yoshida, S; Nonami, Y; Takahashi, T

2001-01-01

135

Sacral perineural cyst accompanying disc herniation.  

PubMed

Although most of sacral perineural cysts are asymptomatic, some may produce symptoms. Specific radicular pain may be due to distortion, compression, or stretching of nerve root by a space occupying cyst. We report a rare case of S1 radiculopathy caused by sacral perineural cyst accompanying disc herniation. The patient underwent a microscopic discectomy at L5-S1 level. However, the patient's symptoms did not improved. The hypesthesia persisted, as did the right leg pain. Cyst-subarachnoid shunt was set to decompress nerve root and to equalize the cerebrospinal fluid pressure between the cephalad thecal sac and cyst. Immediately after surgery, the patient had no leg pain. After 6 months, the patient still remained free of leg pain. PMID:19352483

Ju, Chang Il; Shin, Ho; Kim, Seok Won; Kim, Hyeun Sung

2009-03-01

136

Inguinal herniation with hydrometra/mucometra in a poodle bitch.  

PubMed

A 5-year-old, sexually intact poodle bitch was presented with a 2-year history of inguinal mass. A tentative diagnosis of hydrometra/mucometra with inguinal herniation was made and ovariohysterectomy with hernia repair was performed. Both fluid-filled uterine horns, both broad ligaments, and the uterine body were observed to be herniated through the inguinal ring. On histopathology, marked edema and diffuse hemorrhage were diagnosed in the uterus. PMID:24155486

Sontas, B Hasan; Toydemir, F T Seval; Erdogan, Ozge; Sennazli, Gülbin; Ekici, Hayri

2013-09-01

137

Inguinal herniation with hydrometra/mucometra in a poodle bitch  

PubMed Central

A 5-year-old, sexually intact poodle bitch was presented with a 2-year history of inguinal mass. A tentative diagnosis of hydrometra/mucometra with inguinal herniation was made and ovariohysterectomy with hernia repair was performed. Both fluid-filled uterine horns, both broad ligaments, and the uterine body were observed to be herniated through the inguinal ring. On histopathology, marked edema and diffuse hemorrhage were diagnosed in the uterus. PMID:24155486

Sontas, B. Hasan; Toydemir, F.T. Seval; Erdogan, Özge; ?ennazli, Gülbin; Ekici, Hayri

2013-01-01

138

Idiopathic brain herniation. A report of two paediatric cases.  

PubMed

SUMMARY - 'Idiopathic' herniation of the brain is a rare entity previously reported in 13 cases. It may be incidentally encountered in neuroimaging studies acquired for various clinical indications. We herein describe two cases of idiopathic brain herniation that were incidentally diagnosed. A 12-year-old boy presented with a six-month history of daytime sleepiness and sudden spells of sleep. Herniation of the left inferior temporal gyrus was revealed in MRI acquired with the suspicion of epilepsy. His overnight polysomnogram and multiple sleep latency tests were compatible with the diagnosis of narcolepsy. The other case, a two-year-old girl, was transferred from an outside hospital due to partial seizures with the fever. Herniation of the precuneal gyrus was encountered in MRI acquired after controlling her seizures with the initiation of phenytoin. The brain herniations of both patients were considered to be inconsistent with their medical conditions, so that they were symptom-free with only medical treatment for following three and six months, respectively. This is a rare presentation of idiopathic brain herniation as an incidental finding that accompanied narcolepsy and epilepsy. Awareness of this entity would avoid excessive surgical and medical treatments. PMID:25260205

Koc, Gonca; Doganay, Selim; Bayram, Ayse Kacar; Gorkem, Sureyya Burcu; Dogan, Mehmet Sait; Per, Huseyin; Coskun, Abdulhakim

2014-10-01

139

Omental mesothelial cyst herniated to the thorax through the esophageal hiatus: a case report.  

PubMed

Both mesothelial cyst in the omentum and omental herniation through the esophageal hiatus without abdominal visceral involvement are rare. We report a case of omental mesothelial cyst herniated to the thorax through the esophageal hiatus. PMID:20871418

Lee, Eun Ju; Choi, Yo Won; Jeon, Seok Chol; Heo, Jeong-Nam; Park, Choong Ki; Paik, Seung Sam; Chung, Won Sang

2011-08-01

140

Outcome of symptomatic upper lumbar disc herniation.  

PubMed

"Upper" lumbar disc herniations (LDH) are different from the "lower" and possess increased chance of neural compromise and cauda equina syndrome that necessitates operative management despite of contradictory surgical outcome. We underwent the study to assess the clinical and functional outcome of symptomatic upper LDH surgery from July 2003 to June 2012 in BSMMU, Dhaka, Bangladesh. The records of 123 patients (age range, 30-69 years), 56 men and 67 women (mean 52 years) having upper lumbar discectomy were reviewed. The surgical time, intra-operative blood loss, self evaluated back pain and thigh and/or groin pain status [using Visual Analogue Score (VAS)] and the disability status [using Oswestry disability (ODI) questionnaire] was analyzed. Radiological stability (using Posner's criteria), functional outcome [using Japanese Orthopaedic Association (JOA) Score] and overall outcome (using MacNab`s criteria), was calculated. Chi-squared test and z-test using SPSS revealed mean operative time and mean blood loss had no significant (p>0.05) difference. Pain, sensory, motor and reflex status as well as VAS, ODI and all the components of JOA questionnaire had significant (p<0.05) improvement. In spite of intra-operative complications in 20.32% cases, overall satisfactory outcome was achieved in 83.74% cases. The postoperative complications (08.13%) could be managed conservatively. However, carefully decided surgical alternatives resulted in satisfactory clinical and functional outcome in upper LDH surgery. PMID:25481595

Awwal, M A; Ahsan, M K; Sakeb, N

2014-10-01

141

Omental herniation through the esophageal hiatus mimics mediastinal lipomatous tumor.  

PubMed

A 61-year-old man with a mediastinal abnormal mass on computed tomography is presented. Sagittal sections of magnetic resonance imaging (MRI) clearly indicated the continuity of the fatty mass from the abdomen to the thorax. The diagnosis was an omental herniation through the esophageal hiatus during the operation. First, we returned the omentum into the abdominal cavity, and then repaired the hiatus. The patient had an uneventful postoperative recovery. A herniation of the omentum through the esophageal hiatus is rare; this case is the tenth found in both English and Japanese literatures. The coronal and sagittal planes of MRI were useful in distinguishing the herniation of omentum through the esophageal hiatus from lipomatous tumor. It is our intention of raising awareness about the disease. PMID:15651406

Yunoki, Junji; Ohteki, Hitoshi; Naito, Kozo; Hisajima, Kazuhiro

2004-12-01

142

Omental herniation through the esophageal hiatus in a cat.  

PubMed

A four-year-old male cat was presented with regurgitation. Thoracic radiography and contrast radiogram showed a large oval mass and elevated esophagus. Exploratory thoracotomy showed omental herniation into the posterior mediastium through the esophageal hiatus. Because the mass of the omental herniation was so large, celiotomy through a paracostal incision was combined in order to return the omentum to its normal position. The diameter of the esophageal hiatus was approximately 1 cm but no fibrous adhesion was observed around the hiatus. Continuous 1-0 surgical sutures on the hiatus reduced the diameter of the hiatus. The cat made a successful postoperative recovery without complications. PMID:12520113

Mitsuoka, Kokori; Tanaka, Ryou; Nagashima, Yukiko; Hoshi, Katsuichiro; Matsumoto, Hirokazu; Yamane, Yoshihisa

2002-12-01

143

Investigation of nano-mechanical properties of annulus fibrosus using atomic force microscopy  

Microsoft Academic Search

We describe the use of atomic force microscopy (AFM) to investigate the nanomechanical properties of annulus fibrosus (AF)—the outer fibrous layer of an intervertebral disc (IVD) encapsulating the inner jelly-like mass known as the nucleus pulposus (NP). Disk disease, degenerated discs, slipped discs, and herniated discs are common terms often linked to back pain and are caused due to degeneration

Naama T. Lewis; Mohammad A. Hussain; Jeremy J. Mao

2008-01-01

144

Nucleus Research Inc. NucleusResearch.com  

E-print Network

Document K12 #12;2© 2010 Nucleus Research, Inc. Reproduction in whole or part without written permission. NucleusResearch.com August 2010 Document K12 program even though they were not in complianceNucleus Research Inc. NucleusResearch.com Corporate Headquarters Nucleus Research Inc. 100 State

145

Standards of Practice: Quality Assurance Guidelines for Percutaneous Treatments of Intervertebral Discs  

SciTech Connect

Percutaneous treatments are used in the therapy of small- to medium-sized hernias of intervertebral discs to reduce the intradiscal pressure in the nucleus and theoretically create space for the herniated fragment to implode inward, thus reducing pain and improving mobility and quality of life. These techniques involve the percutaneous removal of the nucleus pulposus by using a variety of chemical, thermal, or mechanical techniques and consist of removal of all or part of nucleus pulposus to induce more rapid healing of the abnormal lumbar disc. These guidelines are written to be used in quality improvement programs for assessing fluoroscopy- and/or computed tomography-guided percutaneous intervertebral disc ablative techniques.

Kelekis, Alexis D., E-mail: akelekis@med.uoa.gr; Filippiadis, Dimitris K., E-mail: dfilippiadis@yahoo.g [Attikon University Hospital, 2nd Radiology Department (Greece); Martin, Jean-Baptiste, E-mail: jbmartin@cird.c [Geneva University Hospital, Service d'Imagerie Medicale (Switzerland); Brountzos, Elias, E-mail: ebrountz@med.uoa.g [Attikon University Hospital, 2nd Radiology Department (Greece)

2010-10-15

146

Aetiology of Herniation of the Hindbrain in Craniosynostosis  

Microsoft Academic Search

The occurrence and extent of herniation of the hindbrain has been evaluated in a population of children with craniosynostosis by means of magnetic resonance imaging of the craniocervical junction. The role of intracranial pressure (ICP), posterior fossa size and hydrocephalus in the development of this deformity has also been assessed. Magnetic resonance imaging (Siemens Magnetom 1.5T) was reviewed in 27

Dominic N. P. Thompson; William Harkness; Barry M. Jones; Richard D. Hayward

1997-01-01

147

Herniation of calcified cervical intervertebral disk in children.  

PubMed

Childhood intervertebral disk calcification is a rare clinical entity and usually has a benign course, generally undergoing spontaneous resolution. However, rapid neurologic deterioration due to herniation, found in both of our cases of calcified cervical intervertebral disks, required urgent anterior discectomy and fusion, resulting in excellent recovery. PMID:1298105

Mohanty, S; Sutter, B; Mokry, M; Ascher, P W

1992-12-01

148

Minimally Invasive Oxygen-Ozone Therapy for Lumbar Disk Herniation  

Microsoft Academic Search

BACKGROUND AND PURPOSE: Oxygen-ozone therapy is a minimally invasive treatment for lumbar disk herniation that exploits the biochemical properties of a gas mixture of oxygen and ozone. We assessed the therapeutic outcome of oxygen-ozone therapy and compared the outcome of administering medical ozone alone with the outcome of medical ozone followed by injection of a corticosteroid and an anesthetic at

Cosma F. Andreula; Luigi Simonetti; Fabio de Santis; Raffaele Agati; Renata Ricci; Marco Leonardi

149

Degenerative Grade Affects the Responses of Human Nucleus Pulposus Cells to Link-N, CTGF, and TGF?3  

PubMed Central

Study Design Cells isolated from moderately and severely degenerated human intervertebral discs (IVDs) cultured in an alginate scaffold. Objective To compare the regenerative potential of moderately vs. severely degenerated cells using three pro-anabolic stimulants. Summary of Background Data Injection of soluble cell signaling factors has potential to slow the progression of IVD degeneration. While degenerative grade is thought to be an important factor in targeting therapeutic interventions it remains unknown whether cells in severely degenerated IVDs have impaired metabolic functions compared to lesser degenerative levels or if they are primarily influenced by the altered microenvironment. Methods NP cells were cultured in alginate for 21 days and treated with three different pro-anabolic stimulants: a growth factor/anti-inflammatory combination of TGF?3+Dex, or matricellular proteins CTGF or Link-N. They were assayed for metabolic activity, DNA content, glycosaminoglycan (GAG), and qRT-PCR gene profiling. Results Moderately degenerated cells responded to stimulation with increased proliferation, decreased IL-1?, MMP9 and COL1A1 expression, and upregulated HAS1 as compared to severely degenerated cells. TGF?R1 (ALK5) receptors were expressed at greater levels in moderately than severely degenerated cells. TGF?3+Dex had a notable stimulatory effect on moderately degenerated NP cells with increased anabolic gene expression, and decreased COL1A1 and ADAMTS5 gene expression. Link-N and CTGF had similar responses in all assays, and both treatments up-regulated IL-1? expression and had a more catabolic response than TGF?3+Dex, particularly in the more severely degenerated group. All groups, including different degenerative grades, produced similar amounts of GAG. Conclusion Pro-anabolic stimulants alone had limited capacity to overcome the catabolic and pro-inflammatory cytokine expression of severely degenerated NP cells and likely require additional anti-inflammatory treatments. Moderately degenerated NP cells had greater TGF? receptor 1 expression and better responded to anabolic stimulation. PMID:22907063

Abbott, Rosalyn D.; Purmessur, Devina; Monsey, Robert D.; Brigstock, David R.; Laudier, Damien M.; Iatridis, James C.

2012-01-01

150

Hemifacial hyperhidrosis associated with ipsilateral/contralateral cervical disc herniation myelopathy. Functional considerations on how compression pattern determines the laterality  

PubMed Central

Summary Sweating is an important mechanism for ensuring constant thermoregulation, but hyperhidrosis may be disturbing. We present five cases of hemifacial hyperhidrosis as a compensatory response to an/hypohidrosis caused by cervical disc herniation. All the patients complained of hemifacial hyperhidrosis, without anisocoria or blepharoptosis. Sweat function testing and thermography confirmed hyperhidrosis of hemifacial and adjacent areas. Neck MRI showed cervical disc herniation. Three of the patients had lateral compression with well-demarcated hypohidrosis below the hyperhidrosis on the same side as the cervical lesion. The rest had paramedian compression with poorly demarcated hyperhidrosis and hypohidrosis on the contralateral side. Although MRI showed no intraspinal pathological signal intensity, lateral dural compression might influence the circulation to the sudomotor pathway, and paramedian compression might influence the ipsilateral sulcal artery, which perfuses the sympathetic descending pathway and the intermediolateral nucleus. Sweat function testing and thermography should be performed to determine the focus of the hemifacial hyperhidrosis, and the myelopathy should be investigated on both sides. PMID:25014051

Iwase, Satoshi; Inukai, Yoko; Nishimura, Naoki; Sato, Maki; Sugenoya, Junichi

2014-01-01

151

Automatic diagnosis of lumbar disc herniation with shape and appearance features from MRI  

NASA Astrophysics Data System (ADS)

Intervertebral disc herniation is a major reason for lower back pain (LBP), which is the second most common neurological ailment in the United States. Automation of herniated disc diagnosis reduces the large burden on radiologists who have to diagnose hundreds of cases each day using clinical MRI. We present a method for automatic diagnosis of lumbar disc herniation using appearance and shape features. We jointly use the intensity signal for modeling the appearance of herniated disc and the active shape model for modeling the shape of herniated disc. We utilize a Gibbs distribution for classification of discs using appearance and shape features. We use 33 clinical MRI cases of the lumbar area for training and testing both appearance and shape models. We achieve over 91% accuracy in detection of herniation in a cross-validation experiment with specificity of 91% and sensitivity of 94%.

Alomari, Raja'S.; Corso, Jason J.; Chaudhary, Vipin; Dhillon, Gurmeet

2010-03-01

152

Use of Magnetic Resonance Imaging to Identify Outcome Predictors of Caudal Epidural Steroid Injections for Lower Lumbar Radicular Pain Caused by a Herniated Disc  

PubMed Central

Objective We used lumbar magnetic resonance image (MRI) findings to determine possible outcome predictors of a caudal epidural steroid injection (CESI) for radicular pain caused by a herniated lumbar disc (HLD). Methods Ninety-one patients with radicular pain whose MRI indicated a HLD were enrolled between September 2010 and July 2013. The CESIs were performed using ultrasound (US). A responder was defined as having complete relief or at least a 50% reduction of pain as assessed by the visual analog scale (VAS) and functional status on the Roland Morris Disability Questionnaire (RMDQ); responder (VAS n=61, RMDQ n=51), and non-responder (VAS n=30, RMDQ n=40). MRI findings were analyzed and compared between the two groups with regard to HLD level, HLD type (protrusion or exclusion), HLD zone (central, subarticular, foraminal, and extraforaminal), HLD volume (mild, moderate, or severe), relationship between HLD and nerve root (no contact, contact, displaced, or compressed), disc height loss (none, less than half, or more than half ), and disc degeneration grade (homogeneous disc structure or inhomogeneous disc structure-clear nucleus and height of intervertebral disc). Results A centrally located herniated disc was more common in the responder group than that in the non-responder group. Treatment of centrally located herniated discs showed satisfactory results. (VAS p=0.025, RMDQ p=0.040). Other factors, such as HLD level, HLD type, HLD volume, relationship to nerve root, disc height loss, and disc degeneration grade, were not critical. Conclusion The HLD zone was significant for pain reduction after CESI. A centrally located herniated disc was a predictor of a good clinical outcome.

Cha, Sung Oh; Jang, Chul Hoon; Hong, Jin Oh; Park, Joon Sang

2014-01-01

153

Percutaneous breast implant herniation: a rare complication of miliary TB.  

PubMed

We describe the case of a 46-year-old female patient treated for disseminated tuberculosis (TB) infection involving the lungs, urinary tract and skin. Following initiation of antituberculous therapy, the patient's right breast implant eroded through the overlying skin and was seen to be herniating through the resulting defect. The breast implant was removed under local anaesthetic and histological analysis of the resected tissue demonstrated granuloma formation consistent with periprosthetic TB. Wound healing following implant removal was poor and future breast augmentation surgery was only considered following completion of 12?months anti-TB treatment. This case constitutes the first report in the literature of percutaneous breast implant herniation resulting from periprosthetic infection with TB. A high index of suspicion is required to ensure early detection and timely management of TB and, in cases where periprosthetic pus aspirate is sterile, mycobacterial infection must be actively excluded. PMID:25568276

Dale, Adam P; Dedicoat, Martin J; Saleem, Tausif; Moran, Ed

2015-01-01

154

Congenital diaphragmatic hernia: delayed presentation with asymptomatic spleenic herniation.  

PubMed

Patients with congenital diaphragmatic hernia (CDH) usually present in the immediate neonatal period with respiratory distress. Presentation beyond the neonatal period has, however, been reported. We report a case of a 3-year-old child who presented with a six months history of respiratory symptoms and had been subjected to a variety of therapies like antibiotics, antitubercular medication and two attempts at putting an intercostal tube, as radiographs were suggestive of pleural effusion. This study highlights the importance of a high index of suspicion, relevance of thorough clinical examination and non-invasive diagnostic modalities along with an uncommon occurrence of asymptomatic spleenic herniation at such a later age. Spleenic herniation is rare outside neonatal period. PMID:11845935

Sehgal, Arvind; Chandra, Jagdish; Singh, Varinder; Dutta, A K; Bagga, Deepak

2002-01-01

155

Establishing the Effect of Vibration and Postural Constraint Loading on the Progression of Intervertebral Disc Herniation.  

E-print Network

??Intervertebral disc herniations have been indicated as a possible injury development pathway due to occupational vibration exposures in seated postures through epidemiological investigations. Little experimental… (more)

Yates, Justin

2009-01-01

156

Acute renal failure caused by bilateral ureteral herniation through the sciatic foramen.  

PubMed

Ureteral herniation is rare. Only a few cases of bilateral ureterosciatic herniation have been reported. We report the case of a 74-year-old woman with flank pain and acute renal failure. The initial ultrasound scan showed bilateral hydronephrosis. Follow-up computed tomography imaging demonstrated sciatic herniation of both ureters, causing bilateral hydronephrosis and hydroureter. The patient underwent bilateral retrograde ureterography and ureteral stent placement, with improvement in renal function to normal limits. Observation after stent removal demonstrated recurrent sciatic herniation of both ureters. Definitive surgical correction was performed by way of laparoscopic bilateral ureterolysis and sciatic notch hernia repair using mesh. PMID:23602799

Whyburn, James J; Alizadeh, Ahmadreza

2013-06-01

157

Herniation of the spinal cord 38 years after childhood trauma  

Microsoft Academic Search

We report an unusual post-traumatic spinal cord herniation, which became symptomatic 38 years after the trauma. A 44-year-old man presented with a 2-year history of increasing impotence, neuropathic bladder dysfunction and dissociated sensory loss below the level of T6. At the age of 6 years he had a severe blunt spinal injury with transient paraparesis. MRI revealed right lateral and

H. Urbach; B. Kaden; U. Pechstein; L. Solymosi

1996-01-01

158

Vitamin K deficiency bleeding presenting as impending brain herniation.  

PubMed

It is presently a universal practice to administer vitamin K at birth. Hence, the serious bleeding manifestations from vitamin K deficiency are nowadays very rare. We describe a case of late vitamin K deficiency bleeding presenting as intracranial hemorrhage with impending coning and the related review of literature. Such severe bleeding episodes due to vitamin K deficiency are associated with multiple cranial involvement and impending brain herniation is probably rare. PMID:21042512

Gopakumar, H; Sivji, R; Rajiv, P K

2010-01-01

159

Vitamin K deficiency bleeding presenting as impending brain herniation  

PubMed Central

It is presently a universal practice to administer vitamin K at birth. Hence, the serious bleeding manifestations from vitamin K deficiency are nowadays very rare. We describe a case of late vitamin K deficiency bleeding presenting as intracranial hemorrhage with impending coning and the related review of literature. Such severe bleeding episodes due to vitamin K deficiency are associated with multiple cranial involvement and impending brain herniation is probably rare. PMID:21042512

Gopakumar, H.; Sivji, R.; Rajiv, P. K.

2010-01-01

160

Cervical lung lobe herniation in dogs identified by fluoroscopy  

PubMed Central

This study aimed to determine the frequency of cervical lung lobe herniation (CLLH) in dogs evaluated fluoroscopically and to identify associated characteristics. Reports of diagnostic procedures and patient summaries from 2008 to 2010 were reviewed retrospectively. Signalment, body weight, duration of cough, presence of heart murmur and airway collapse, and radiographic findings were compared between dogs with and without CLLH. Of the 121 dogs that were examined, CLLH occurred in 85 (70%). The extra-thoracic trachea kinked during herniation in 33 (39%) dogs with CLLH. Collapse of the intra-thoracic trachea (assessed fluoroscopically or bronchoscopically) and collapse of major bronchi (assessed fluoroscopically) were strongly associated with CLLH. Although redundant dorsal tracheal membrane on radiographs was associated with CLLH, extra-thoracic tracheal collapse, assessed fluoroscopically or bronchoscopically, was not. No other associations were found. Cervical lung lobe herniation was present in most dogs evaluated during cough and was associated with intra-thoracic large airway collapse, but not duration of cough. PMID:24155415

Nafe, Laura A.; Robertson, Ian D.; Hawkins, Eleanor C.

2013-01-01

161

Recurrent wound dehiscence and small bowel herniation following Caesarean section in a woman with hidradenitis suppurativa.  

PubMed

Caesarean wound dehiscence that is severe enough to result in bowel herniation is exceptionally rare. This case describes a woman who experienced wound dehiscence following each of her two Caesarean sections, with bowel herniation present in the second case. The contribution of her comorbid hidradenitis suppurativa will be discussed. PMID:24876503

Fernando, Magage; Schultz, Meleesa J

2014-01-01

162

Plasma disc decompression for contained cervical disc herniation: a randomized, controlled trial  

PubMed Central

Prospective case series studies have shown that plasma disc decompression (PDD) using the COBLATION SpineWand device (ArthroCare Corporation, Austin, TX) is effective for decompressing the disc nucleus in symptomatic contained cervical disc herniations. This prospective, randomized controlled clinical trial was conducted to evaluate the clinical outcomes of percutaneous PDD as compared to conservative care (CC) through 1 year. Patients (n = 115) had neck/arm pain >50 on the visual analog scale (VAS) pain scale and had failed at least 30 days of failed CC. Patients were randomly assigned to receive either PDD (n = 62) or CC (n = 58). Clinical outcome was determined by VAS pain score, neck disability index (NDI) score, and SF-36 health survey, collected at 6 weeks, 3 months, 6 months, and 1 year. The PDD group had significantly lower VAS pain scores at all follow-up time points (PDD vs. CC: 6 weeks, ?46.87 ± 2.71 vs. ?15.26 ± 1.97; 3 months, ?53.16 ± 2.74 vs. ?30.45 ± 2.59; 6 months, ?56.22 ± 2.63 vs. ?40.26 ± 2.56; 1 year, ?65.73 ± 2.24 vs. ?36.45 ± 2.86; GEE, P < 0.0001). PDD patients also had significant NDI score improvement over baseline when compared to CC patients at the 6 weeks (PDD vs. CC: ?9.15 ± 1.06 vs. ?4.61 ± 0.53, P < 0.0001) and 1 year (PDD vs. CC: ?16.70 ± 0.29 vs. ?12.40 ± 1.26, P = 0.005) follow-ups. PDD patients showed statistically significant improvement over baseline in SF-36 physical component summary scores when compared to CC patients at 6 weeks and 1 year (PDD vs. CC: 8.86 + 8.04 vs. 4.24 ± 3.79, P = 0.0004; 17.64 ± 10.37 vs. 10.50 ± 10.6, P = 0.0003, respectively). In patients who had neck/arm pain due to a contained cervical disc herniation, PDD was associated with significantly better clinical outcomes than a CC regimen. At 1 year, CC patients appeared to suffer a “relapse, showing signs of decline in most measurements, whereas PDD patients showed continued stable improvement. PMID:19902277

Nardi, Pier Vittorio

2009-01-01

163

Biomaterials 27 (2006) 388396 The potential of chitosan-based gels containing intervertebral  

E-print Network

cells for nucleus pulposus supplementation Peter Roughleya,Ã?, Caroline Hoemannb , Eric Des of a functional extracellular matrix mimicking that of the nucleus pulposus (NP) was investigated. The specific encapsulation; Hydrogel; Intervertebral disc; Nucleus pulposus; Proteoglycan 1. Introduction The intervertebral

Buschmann, Michael

164

Herniation of uncus and parahippocampal gyrus: an accidental finding on magnetic resonance imaging of cerebrum.  

PubMed

Idiopathic herniation of uncus and parahippocampal gyrus into the ambient cistern is a very rare entity, which could be mistaken for other pathology such as tumor. To the best of our knowledge, two prior cases of this kind of herniation have been described. One of these cases was with associated symptomatology and other abnormalities, and the other was characterized as idiopathic. In this case report, we report a case of accidental finding of a herniation of uncus and parahippocampal gyrus into the ambient cistern, without any other accompanying abnormalities, well depicted by magnetic resonance imaging without further necessity for surgical brain intervention. PMID:25610616

Yavarian, Yousef; Bayat, Michael; Brøndum Frøkjær, Jens

2015-01-01

165

Herniation of uncus and parahippocampal gyrus: an accidental finding on magnetic resonance imaging of cerebrum  

PubMed Central

Idiopathic herniation of uncus and parahippocampal gyrus into the ambient cistern is a very rare entity, which could be mistaken for other pathology such as tumor. To the best of our knowledge, two prior cases of this kind of herniation have been described. One of these cases was with associated symptomatology and other abnormalities, and the other was characterized as idiopathic. In this case report, we report a case of accidental finding of a herniation of uncus and parahippocampal gyrus into the ambient cistern, without any other accompanying abnormalities, well depicted by magnetic resonance imaging without further necessity for surgical brain intervention. PMID:25610616

Bayat, Michael; Brøndum Frøkjær, Jens

2015-01-01

166

Histology of Herniations through the Body Wall and Cuticle of Zooplankton from the Laurentian Great Lakes  

E-print Network

Histology of Herniations through the Body Wall and Cuticle of Zooplankton from the Laurentian Great a histologic and cyto- logic analysis of the protrusions and found that they are composed of apparently

167

Percutaneous Thoracic Intervertebral Disc Nucleoplasty: Technical Notes from 3 Patients with Painful Thoracic Disc Herniations  

PubMed Central

Symptomatic thoracic disc herniation is an uncommon condition and early surgical approaches were associated with significant morbidity and even mortality. We are the first to describe the technique of percutaneous thoracic nucleoplasty in three patients with severe radicular pain due to thoracic disc herniation. Two of the patients experienced more than 75% pain relief and one patient experienced more than 50% pain relief. Post-procedural pain relief was maintained up to an average of 10 months after nucleoplasty. One patient with preoperative neurological signs improved postoperatively. There were no reported complications in all three patients. In view of the reduced morbidity and shorter operating time, thoracic intervertebral disc nucleoplasty can be considered in patients with pain due to thoracic disc herniation, with no calcification of the herniated disc, and in patients who may be otherwise be unfit for conventional surgery. PMID:21386942

Gültuna, Ismail; Riezebos, Patricia; Beems, Tjemme; Vissers, Kris C.

2011-01-01

168

Diaphragmatic Herniation through Prosthetic Material after Extrapleural Pneumonectomy: Be Aware of Tumor Recurrence  

PubMed Central

Extrapleural pneumonectomy (EPP) is indicated in selected group of patients with pleural mesothelioma. Diaphragmatic reconstruction represents a part of this complex operation. We present the case of a late diaphragmatic gastric herniation through prosthetic material after EPP. PMID:25360411

Pop, Daniel; Cohen, Charlotte; Schneck, Anne-Sophie; Nadeemy, Ahmad S.; Venissac, Nicolas; Mouroux, Jerome

2013-01-01

169

A Case of Spontaneous Temporomandibular Joint Herniation into the External Auditory Canal with Clicking Sound  

PubMed Central

A bony defect of the external auditory canal (EAC) and herniation of the temporomandibular joint (TMJ) can be caused by tumorous conditions, inflammation, trauma, and otologic procedures. Spontaneous TMJ herniation into the EAC can be caused by a congenital bony defect known as patent Huschke's foramen, which is a very rare condition. In our case, an objective clicking sound was produced when the patient opened his mouth. A protruding mass was found in the anterior wall of the EAC during mouth closing, and herniation of the TMJ was confirmed with computed tomography. Therefore, we thought the clicking sound of our case could have resulted from spontaneous TMJ herniation through the patent foramen of Huschke. PMID:24653913

Kim, Tae Hyun; Lee, Sun Kyu; Kim, Su Jin

2013-01-01

170

Case report: Complex retroperitoneal herniation after abdominoperineal resection  

PubMed Central

INTRODUCTION We describe the occurrence of a retroperitoneal hernia into the colonic mesentery after abdomoniperineal resection (APR) for rectal cancer. PRESENTATION OF CASE A 70 year old male presented with complete small bowel obstruction secondary to a complex retroperitoneal herniation. Operative repair was carried out with successful reduction of the hernia contents. DISCUSSION A review of the literature is reported concerning retroperitoneal hernia. This occurrence is rare in the adult. Management of the resultant pelvic space after APR is discussed. Closure of the pelvic peritoneum is helpful in avoiding this and other similar complications. CONCLUSION We believe this to be the first report of a small bowel obstruction secondary to this unusual hernia circumstance. Although rare, due vigilance and thorough imaging can lead to effective and timely management of this complication. PMID:22975445

Alkhoury, Fuad; Martin, Jeremiah

2012-01-01

171

Surgical vs Nonoperative Treatment for Lumbar Disk Herniation  

PubMed Central

Context Lumbar diskectomy is the most common surgical procedure performed for back and leg symptoms in US patients, but the efficacy of the procedure relative to nonoperative care remains controversial. Objective To assess the efficacy of surgery for lumbar intervertebral disk herniation. Design, Setting, and Patients The Spine Patient Outcomes Research Trial, a randomized clinical trial enrolling patients between March 2000 and November 2004 from 13 multidisciplinary spine clinics in 11 US states. Patients were 501 surgical candidates (mean age, 42 years; 42% women) with imaging-confirmed lumbar intervertebral disk herniation and persistent signs and symptoms of radiculopathy for at least 6 weeks. Interventions Standard open diskectomy vs nonoperative treatment individualized to the patient. Main Outcome Measures Primary outcomes were changes from baseline for the Medical Outcomes Study 36-item Short-Form Health Survey bodily pain and physical function scales and the modified Oswestry Disability Index (American Academy of Orthopaedic Surgeons MODEMS version) at 6 weeks, 3 months, 6 months, and 1 and 2 years from enrollment. Secondary outcomes included sciatica severity as measured by the Sciatica Bothersomeness Index, satisfaction with symptoms, self-reported improvement, and employment status. Results Adherence to assigned treatment was limited: 50% of patients assigned to surgery received surgery within 3 months of enrollment, while 30% of those assigned to nonoperative treatment received surgery in the same period. Intent-to-treat analyses demonstrated substantial improvements for all primary and secondary outcomes in both treatment groups. Between-group differences in improvements were consistently in favor of surgery for all periods but were small and not statistically significant for the primary outcomes. Conclusions Patients in both the surgery and the nonoperative treatment groups improved substantially over a 2-year period. Because of the large numbers of patients who crossed over in both directions, conclusions about the superiority or equivalence of the treatments are not warranted based on the intent-to-treat analysis. Trial Registration clinicaltrials.gov Identifier: NCT00000410 PMID:17119140

Weinstein, James N.; Tosteson, Tor D.; Lurie, Jon D.; Tosteson, Anna N. A.; Hanscom, Brett; Skinner, Jonathan S.; Abdu, William A.; Hilibrand, Alan S.; Boden, Scott D.; Deyo, Richard A.

2008-01-01

172

Gluteus maximus calcific tendonosis: a rare cause of sciatic pain.  

PubMed

Extraspinal causes of radicular pain are rare and are in danger of being overlooked. Here, we present a patient with pain radiating into the posterior thigh and lateral calf. Although initial differential diagnosis included lumbar herniated nucleus pulposus, further imaging revealed the presence of gluteus maximus calcific tendonosis. After physical therapy and a potent oral steroid regimen, the pain gradually resolved and the patient was able to return to full activity. PMID:25133622

Singh, Jaspal R; Yip, Kevin

2015-02-01

173

The Cochlear NucleusThe Cochlear Nucleus Maria E. Rubio  

E-print Network

are labelled with a DAPI counterstain. The scale bar is 200 µm. Caudal Cochlear Nucleus & Auditory Nerve Fibers Nucleus (VCN) The Core The granular cell domain (GCD; cap) Dorsal Cochlear Nucleus (DCN; layered) 1 domain (GCD; cap) Ventral Cochlear Nucleus (VCN): SubdivisionsVentral Cochlear Nucleus (VCN

Oliver, Douglas L.

174

Cellulite: from standing fat herniation to hypodermal stretch marks.  

PubMed

There are glaring discrepancies in the microanatomical descriptions of cellulite in the literature. We revisited this common skin condition in women with a microscopic examination of 39 autopsy specimens. A control group consisted of 4 women and 11 men showing no evidence of cellulite. The lumpy aspect of the dermohypodermal interface appeared to represent a gender-linked characteristic of the thighs and buttocks without being a specific sign of cellulite. Incipient cellulite identified by the mattress phenomenon was related to the presence of focally enlarged fibrosclerotic strands partitioning the subcutis. Such strands possibly serve as a physiologic buttress against fat herniation limiting the outpouching of fat lobules on pinching the skin. These structures might represent a reactive process to sustained hypodermal pressure caused by fat accumulation. Full-blown cellulite likely represents subjugation of the hypertrophic response when connective tissue is overcome by progressive fat accumulation. Histologic aspects reminiscent of stretch marks are identified within the hypodermal strands, resulting in clinical skin dimpling. PMID:10698214

Piérard, G E; Nizet, J L; Piérard-Franchimont, C

2000-02-01

175

Hemilaminoplasty for the treatment of lumbar disc herniation  

PubMed Central

The aim of this study was to evaluate the clinical outcome of the hemilaminoplasty technique for the treatment of lumbar disc herniation (LDH). Forty-three cases of single-level LDH underwent a discectomy and hemilaminoplasty procedure. The preoperative JOA score and VAS of lower back and leg pain were 10.4±1.3, 7.8±2.1, and 8.6±1.7, respectively. The Cobb angle of lumbar sagittal alignment was 10.1±2.0. Twenty-five patients who agreed to lumbar discectomy through fenestration were enrolled as the control group. The postoperative JOA score and VAS of low back and leg pain of the hemilaminoplasty group were 19.4±1.3, 1.4±0.4, and 2.1±0.5, respectively. The Cobb angle was 29.2±1.9 degrees. There was no epidural scar observed in any of the patients. The Cobb angle of the hemilaminoplasty group was higher than that of the control group (p?

Xinyu, Liu; Jianmin, Li; Liangtai, Gong

2008-01-01

176

Magnetic resonance imaging of the lumbar herniated disc in pregnancy.  

PubMed

Lumbosacral pain is a significant complaint in approximately one-half of all pregnancies. In 15%, the pain can be disabling. Although the mechanical and positional stresses of pregnancy have been cited as the primary source of this discomfort, in approximately 1:10,000 cases a herniated lumbar disc (HNP) can be identified as the proximal cause of pain. A 35-yr-old G4AB3PO patient presenting at 10 wk of pregnancy with severe incapacitating lumbar radiculopathy is described. Magnetic resonance imaging, selected by the patient as a diagnostic option, demonstrated a clinically suspected large midline HNP at the L5-S1 level. In the past, visualizing the presence of a HNP during pregnancy by either computerized axial tomography scan or myelography has exposed the fetus to ionizing radiation. However, magnetic resonance imaging now permits a more detailed evaluation without similar x-ray exposure. To date, no recognized biologic effect of MRI on the developing fetus has been reported. Although the long-term effects of an magnetic resonance imaging on the developing fetus have not been conclusively evaluated, its potential for accurate diagnosis and subsequent patient management, as well as planning the delivery, appears to outweigh any recognized hazard to the developing fetus. PMID:7873115

LaBan, M M; Viola, S; Williams, D A; Wang, A M

1995-01-01

177

Enucleation/partial nephrectomy for large mixed epithelial stromal tumor and herniating into the pelvicalyceal system  

PubMed Central

Objectives: Mixed Epithelial and Stromal Tumor of the kidney is an adult renal neoplasm. It is mostly benign in nature. Typically it is composed of a mixture of epithelial and mesenchymal components. We hereby report on the feasibility of performing partial nephrectomy/enucleation for Huge Mixed Epithelial Stromal Tumor of the kidney without sacrificing the involved renal unit even in the tumors herniating into the collecting system. Methods: Two female patients on long term hormonal therapy developed large enhancing multiloculated and septated renal masses. Kidney mass size was 18.5 cms in one patient and 11.5 in the second. In one patient, the mass was herniating into the collecting system. Both patients had enucleation/partial nephrectomy. Results: Enucleation and partial nephrectomy were successfully performed in both patients. In the patient with the mass herniating into the collecting system, the horns of the mass herniating into the collecting system were easily enucleated with repair of the collecting system and salvage of the involved renal unit. Post op pathology revealed MEST in both patients. There were no intraoperative or postoperative complications. Conclusions: Enucleation and partial nephrectomy for huge MEST is feasible. Mixed Epithelial Stromal Tumor herniating into the pelvicalyceal system may not warrant nephroureterectomy as previously reported. PMID:25371624

Kamel, Mohamed H.; Davis, Rodney; Cox, Roni M.; Cole, Adam; Eltahawy, Ehab

2014-01-01

178

Intrathoracic omental herniation through the esophageal hiatus: report of a case.  

PubMed

We report herein an extremely rare case of intrathoracic omental herniation through the esophageal hiatus. In fact, according to our review of the literature, only eight other cases have been reported, most of which were misdiagnosed as mediastinal lipoma after being identified as an intrathoracic mass. We report herein the ninth case of intrathoracic omental herniation through the esophageal hiatus. A 54-year-old obese woman was admitted to our hospital for investigation of a chest roentgenographic abnormality. She was asymptomatic, and her physical examination and laboratory data were all within normal limits. Her chest X-ray demonstrated a large, sharply-defined mass, and a computed tomography scan of the thorax indicated a large mediastinal mass with fat density. A thoracotomy was performed under the diagnosis of a mediastinal lipoma which revealed an encapsulated fatty mass, 10x7.5x6 cm in size, that proved to be an omental herniation through the esophageal hiatus. There was no herniation of the stomach or intestines into the thorax. The esophageal hiatus was repaired after the omental mass and hernia sac had been resected. This case report serves to demonstrate that whenever a mass of fat density is recognized in the lower thorax, an omental herniation should be borne in mind as a possible differential diagnosis. PMID:10211566

Kato, N; Iwasaki, H; Rino, Y; Imada, T; Amano, T; Kondo, J

1999-01-01

179

Co-occurrence of lumbar spondylolysis and lumbar disc herniation with lumbosacral nerve root anomaly  

PubMed Central

Lumbosacral nerve root anomalies are the leading cause of lumbar surgery failures. Although co-occurrence of lumbar spondylolysis and disc herniation is common, it is very rare to observe that a nerve root anomaly accompanies these lesions. A 49-year-old male patient presented with sudden-onset right leg pain. Examinations revealed L5/S1 lumbar spondylolysis and disc herniation. At preoperative period, he was also diagnosed with lumbosacral root anomaly. Following discectomy and root decompression, stabilization was performed. The complaints of the patient diagnosed with lumbosacral root anomaly at intraoperative period were improved at postoperative period. It should be remembered that in patients with lumbar disc herniation and spondylolysis, lumbar root anomalies may coexist when clinical and neurological picture is severe. Preoperative and perioperative assessments should be made meticulously to prevent neurological injury. PMID:25210343

Y?lmaz, Tevfik; Turan, Yahya; Gül?en, ?smail; Dalbayrak, Sedat

2014-01-01

180

Conservative management of recurrent lumbar disk herniation with epidural fibrosis: a case report  

PubMed Central

Objective A retrospective case report of a 24-year-old man with recurrent lumbar disk herniation and epidural fibrosis is presented. Recurrent lumbar disk herniation and epidural fibrosis are common complications following lumbar diskectomy. Clinical Features A 24-year-old patient had a history of lumbar diskectomy and new onset of low back pain and radiculopathy. Magnetic resonance imaging revealed recurrent herniation at L5/S1, left nerve root displacement, and epidural fibrosis. Intervention and Outcomes The patient received a course of chiropractic care including lumbar spinal manipulation and rehabilitation exercises with documented subjective and objective functional and symptomatic improvement. Conclusion This case report describes chiropractic management including spinal manipulative therapy and rehabilitation exercises and subsequent objective and subjective functional and symptomatic improvement. PMID:23843756

Welk, Aaron B.; Werdehausen, Destiny N.; Kettner, Norman W.

2012-01-01

181

A ventral incisional hernia with herniation of the left hepatic lobe and review of the literature.  

PubMed

Ventral incisional hernias with hepatic herniation are extremely rare. Only six cases have been reported so far in the literature. We report a case of a ventral incisional hernia with hepatic herniation along with a review of the literature. A 70-year-old female patient with a history of coronary artery bypass graft surgery 6?months earlier, was admitted to our hospital with symptoms of epigastric swelling and discomfort for 3?months. On examination, she had a mild tender 5?cm×5?cm epigastric lump and was diagnosed as ventral incisional hernia. Contrast-enhanced CT of the abdomen revealed a ventral hernia with herniation of omentum and left hepatic lobe. The patient underwent onlay mesh repair and is asymptomatic at 1-month follow-up. There is a need for evaluation of risk factors for this type of ventral incisional hernia and to recognise it as a special entity. PMID:25631758

Neelamraju Lakshmi, Harish; Saini, Devendra; Om, Prabha; Bagree, Rajendra

2015-01-01

182

Five and Ten Year Follow-up on Intradiscal Ozone Injection for Disc Herniation  

PubMed Central

Background Disc herniation is the most common cause for spinal surgery and many clinicians employ epidural steroid injections with limited success. Intradiscal injection of ozone gas has been used as an alternative to epidural steroids and surgical discectomy. Early results are positive but long-term data are limited. Methods One hundred and eight patients with confirmed contiguous disc herniation were treated with intradiscal injection of ozone in 2002-2003. One-hundred seven patients were available for telephone follow-up at 5 years. Sixty patients were available for a similar telephone follow-up at ten years. Patients were asked to describe their clinical outcome since the injection. Surgical events were documented. MRI images were reviewed to assess the reduction in disc herniation at six months. Results MRI films demonstrated a consistent reduction in the size of the disc herniation. Seventy-nine percent of patients had a reduction in herniation volume and the average reduction was 56%. There were 19 patients that ultimately had surgery and 12 of them occurred in the first six months after injection. One of these 12 was due to surgery at another level. Two surgeries involved an interspinous spacer indicated by stenosis or DDD. All other surgeries were discectomies. Of the patients that avoided surgery 82% were improved at 5 years and 88% were improved at 10 years. Other than subsequent surgeries, no spine-related complications were experienced. Conclusions/Level of Evidence We conclude that ozone is safe and effective in approximately 75% of patients with disc herniation and the benefit is maintained through ten years. This is a retrospective review and randomized trials are needed. Clinical Relevance Intradiscal ozone injection may enable patients to address their pain without multiple epidural injections and surgery. The benefit of ozone is durable and does not preclude future surgical options. The risk reward profile for this treatment is favorable. PMID:25694935

Buric, Josip; Rigobello, Luca; Hooper, David

2014-01-01

183

Prevalence and Severity of Preoperative Disabilities in Iranian Patients with Lumbar Disc Herniation  

PubMed Central

Background: Literature recommends that refractory cases with lumbar disc herniation and appropriate indications are better to be treated surgically, but do all the patients throughout the world consent to the surgery with a same disability and pain threshold? We aim to elucidate the prevalence and severity of disabilities and pain in Iranian patients with lumbar disc herniation who have consented to the surgery. Methods: In this case series study, we clinically evaluated 194 (81 female and 113 male) admitted patients with primary, simple, and stable L4-L5 or L5-S1 lumbar disc herniation who were undergoing surgical discectomy. The mean age of the patients was 38.3±11.2 (range: 18-76 years old). Disabilities were evaluated by the items of the Oswestry Disability Index (ODI) questionnaire and severity of pain by the Visual Analogue Scale (VAS). Chi-square test was used to compare the qualitative variables. Results: Severe disability (39.2%) and crippled (29.9%) were the two most common types of disabilities. Mean ODI score was 56.7±21.1 (range: 16-92). Total mean VAS in all patients was 6.1±1.9 (range: 0-10). Sex and level of disc herniation had no statistical effect on preoperative ODI and VAS. The scale of six was the most frequent scale of preoperative VAS in our patients. Conclusion: Iranian patients with lumbar disc herniation who consented to surgery have relatively severe pain or disability. These severities in pain or disabilities have no correlation with sex or level of disc herniation and are not equal with developed countries. PMID:25207293

Omidi-Kashani, Farzad; Hasankhani, Ebrahim Ghayem; Moghadam, Mohammad Hallaj; Esfandiari, Mohammad Sadegh

2013-01-01

184

Non traumatic liver herniation due to persistent cough mimicking a pulmonary mass  

PubMed Central

Background: Non traumatic liver herniation through a diaphragmatic defect is rare. Case Report: A 44 year old woman presented with lower lobe opacity at the right lung. Chest Computed tomography (CT) demonstrated a round tumor adjacent to the right diaphragm. Percutaneous needle biopsy revealed liver tissue. A small liver herniation through a diaphragmatic defect was detected in saggital and coronal CT views but no traumatic rupture of the diaphragm or endometriosis were documented. Conclusions: The patient suffered from gastroesophageal reflux disease and increased transdiaphragmatic pressure from paroxysmal cough due to aspirations may have provoked the diaphragmatic rupture. PMID:25031522

Pataka, A; Paspala, A; Sourla, E; Bagalas, V; Argyropoulou, P

2013-01-01

185

Sensitivity analysis of permeability parameters of bovine nucleus pulposus obtained through inverse fitting of the nonlinear biphasic equation: effect of sampling strategy  

Microsoft Academic Search

Permeability controls the fluid flow into and out of soft tissue, and plays an important role in maintaining the health status of such tissue. Accurate determination of the parameters that define permeability is important for the interpretation of models that incorporate such processes. This paper describes the determination of strain-dependent permeability parameters from the nonlinear biphasic equation from experimental data

Philip E. Riches

2011-01-01

186

Sensitivity analysis of permeability parameters of bovine nucleus pulposus obtained through inverse fitting of the nonlinear biphasic equation: effect of sampling strategy  

Microsoft Academic Search

Permeability controls the fluid flow into and out of soft tissue, and plays an important role in maintaining the health status of such tissue. Accurate determination of the parameters that define permeability is important for the interpretation of models that incorporate such processes. This paper describes the determination of strain-dependent permeability parameters from the nonlinear biphasic equation from experimental data

Philip E. Riches

2012-01-01

187

Lumbar Disc Herniation in a Patient With Congenital Vertebral Body Anomaly: A Case Report  

PubMed Central

Lumbar disc herniation is characterized with low back and leg pain resulting from the degenerated lumbar disc compressing the spinal nerve root. The etiology of degenerative spine is related to age, smoking, microtrauma, obesity, disorders of familial collagen structure, occupational and sports-related physical activity. However, disc herniations induced by congenital lumbar vertebral anomalies are rarely seen. Vertebral fusion defect is one of the causes of congenital anomalies. The pathogenesis of embryological corpus vertebral fusion anomaly is not fully known. In this paper, a 30-year-old patient who had the complaints of low back and right leg pain after falling from a height is presented. She had right L5-S1 disc herniation that had developed on the basis of S1 vertebra corpus fusion anomaly in Lumbar computed tomography. This case has been discussed in the light of literature based on evaluations of Lumbar Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). This case is unique in that it is the first case with development of lumbar disc herniation associated with S1 vertebral corpus fusion anomaly. Congenital malformations with unusual clinical presentation after trauma should be evaluated through advanced radiological imaging techniques. PMID:25620987

Atabey, Cem; Topuz, Ali Kivanc; Velio?lu, Murat; Demircan, Mehmet Nusret

2014-01-01

188

Diagnosis of Disc Herniation Based on Classifiers and Features Generated from Spine MR Images  

E-print Network

Diagnosis of Disc Herniation Based on Classifiers and Features Generated from Spine MR Images patients suffer from lumbar disorders and radiologists have to treat more patients reliably in a limited of diagnostic radiologists.3 Accordingly, the demand for computer-assisted image processing and analysis has

Chaudhary, Vipin

189

Airway obstruction caused by endotracheal tube cuff herniation during creation of tracheal stoma.  

PubMed

We report an unusual case of airway obstruction caused by herniation of endotracheal tube (ETT) cuff in a 62-year-old male who underwent surgery for hypopharyngeal carcinoma. During the procedure of creating a tracheal stoma, a new oral ETT was inserted by the surgical team to the lower portion of the trachea through the cut opening to replace the old for ventilation and prevention of soiling of the airway. Upon resumption of surgical manipulation, right endobronchial intubation was disclosed. The ETT cuff was therefore repositioned and reinflated, but airway obstruction persisted in spite of tube obstruction being ruled out by successfully passing a suction catheter through the ETT. After deflating the cuff the obstruction was resolved, and ventilation was eased. Thus the ETT was replaced with another new one and careful scrutiny made after the event revealed a herniating cuff due to manufacturing defect. It was conceivable that endobronchial intubation with over-inflation of the tube cuff may cause cuff herniation, particularly when surgical manipulation was active at the adjacency, in spite of the use of a modern tube with low-pressure high-volume cuff. Performing the "cuff deflation test" is the simple way to diagnose cuff herniation. Awareness of this condition, especially when anesthesiologists lose direct control of the airway during such procedures is important because undesirable complications can be prevented through quick decision and action. PMID:15869007

Kao, Ming-Chang; Yu, Ya-Sheng; Liu, Hsu-Tang; Tsai, Shen-Kou; Lin, Su-Man; Huang, Ying-Che

2005-03-01

190

Idiopathic Ventral Spinal Cord Herniation: An Increasingly Recognized Cause of Thoracic Myelopathy  

PubMed Central

Idiopathic spinal cord herniation (ISCH), where a segment of the spinal cord has herniated through a ventral defect in the dura, is a rarely encountered cause of thoracic myelopathy. The purpose of our study was to increase the clinical awareness of this condition by presenting our experience with seven consecutive cases treated in our department since 2005. All the patients developed pronounced spastic paraparesis or Brown-Séquard syndrome for several years (mean, 4.7 years) prior to diagnosis. MRI was consistent with a transdural spinal cord herniation in the mid-thoracic region in all the cases. The patients underwent surgical reduction of the herniated spinal cord and closure of the dural defect using an artificial dural patch. At follow-up, three patients experienced considerable clinical improvement, one had slight improvement, one had transient improvement, and two were unchanged. Two of the four patients with sphincter dysfunction regained sphincter control. MRI showed realignment of the spinal cord in all the patients. ISCH is probably a more common cause of thoracic myelopathy than previously recognized. The patients usually develop progressive myelopathy for several years before the correct diagnosis is made. Early diagnosis is important in order to treat the patients before the myelopathy has become advanced. PMID:25336997

Berg-Johnsen, Jon; Ilstad, Eivind; Kolstad, Frode; Züchner, Mark; Sundseth, Jarle

2014-01-01

191

Spontaneous Cervical Intradural Disc Herniation Associated with Ossification of Posterior Longitudinal Ligament  

PubMed Central

Intradural herniation of a cervical disc is rare; less than 35 cases have been reported to date. A 52-year-old man with preexisting ossification of posterior longitudinal ligament developed severe neck pain with Lt hemiparesis while asleep. Neurological exam was consistent with Brown-Séquard syndrome. Magnetic resonance images showed a C5-6 herniated disc that was adjacent to the ossified ligament and indenting the cord. The mass was surrounded by cerebrospinal fluid signal intensity margin, and caudally the ventral dura line appears divided into two, consistent with the “Y-sign” described by Sasaji et al. Cord edema were noted. Because of preexisting canal stenosis and spinal cord at risk, a laminoplasty was performed, followed by an anterior C6 corpectomy. Spot-weld type adhesions of the posterior longitudinal ligament to the dura was noted, along with a longitudinal tear in the dura. An intradural extra-arachnoid fragment of herniated disc was removed. Clinical exam at 6 months after surgery revealed normal muscle strength but persistent mild paresthesias. It is difficult to make a definite diagnosis of intradural herniation preoperatively; however, the clinical findings and radiographic signs mentioned above are suggestive and should alert the surgeon to look for an intradural fragment. PMID:25295205

Wang, Dachuan; Wang, Haifeng; Shen, Wun-Jer

2014-01-01

192

Lumbar disc herniation in a patient with congenital vertebral body anomaly: a case report.  

PubMed

Lumbar disc herniation is characterized with low back and leg pain resulting from the degenerated lumbar disc compressing the spinal nerve root. The etiology of degenerative spine is related to age, smoking, microtrauma, obesity, disorders of familial collagen structure, occupational and sports-related physical activity. However, disc herniations induced by congenital lumbar vertebral anomalies are rarely seen. Vertebral fusion defect is one of the causes of congenital anomalies. The pathogenesis of embryological corpus vertebral fusion anomaly is not fully known. In this paper, a 30-year-old patient who had the complaints of low back and right leg pain after falling from a height is presented. She had right L5-S1 disc herniation that had developed on the basis of S1 vertebra corpus fusion anomaly in Lumbar computed tomography. This case has been discussed in the light of literature based on evaluations of Lumbar Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). This case is unique in that it is the first case with development of lumbar disc herniation associated with S1 vertebral corpus fusion anomaly. Congenital malformations with unusual clinical presentation after trauma should be evaluated through advanced radiological imaging techniques. PMID:25620987

Atabey, Cem; Ero?lu, Ahmet; Topuz, Ali Kivanc; Velio?lu, Murat; Demircan, Mehmet Nusret

2014-12-01

193

Abnormal anatomy of inferior orbital fissure and herniation of buccal fat pad.  

PubMed

The anatomy of the inferior orbital fissure has been well studied, and its reported dimensions vary little. It is encountered during exploration of the orbital floor and when possible is not disturbed. We describe a case of herniation of buccal fat through the inferior orbital fissure that was found during exploration and repair of the orbital floor. PMID:25451070

Aldridge, T; Thomson, A; Ilankovan, V

2015-01-01

194

Single Lung Retransplantation for Graft Infarction due to Herniation of Heart  

PubMed Central

A young woman with terminal respiratory failure due to idiopathic pulmonary hypertension underwent bilateral lung transplantation. The postoperative course was complicated by herniation of the heart through over the cut pericardial edge on left side leading to left-sided graft infarction requiring pneumonectomy. Unable to wean off mechanical ventilation, patient required lobar transplantation on the left side. PMID:25360412

Mohite, Prashant N.; Sabashnikov, Anton; Rao, Praveen; Zych, Bartlomiej; Simon, André

2013-01-01

195

Clinical Features and Surgical Results of Cervical Myelopathy Caused by Soft Disc Herniation  

PubMed Central

Objective There are many causes of cervical myelopathy including trauma, degenerative conditions, tumors and demyelinating disorders. However, myelopathy caused by soft disc herniation might be seen rarely than the spondylosis caused by hard disc. Here, authors retrospectively analyzed the clinical features and results of cervical myelopathy caused by soft disc herniation. Methods From March 2010 to December 2010, 134 patients with degenerative cervical spinal disease were treated with anterior cervical discectomy and interbody fusion. Among them, 21 patients with cervical myelopathy secondary to cervical soft disc herniation were analyzed. Their clinical features, preoperative and, postoperative clinical results were evaluated by Nurick Grade and Japanese Orthopaedic Association scale (JOA) retrospectively. Preoperative clinical features including duration of myelopathy, pain intensity and postoperative clinical results including improvement rate of myelopathy and radiculopathy were retrospectively analyzed by Nurick Grade and JOA scale. We also evaluated correlation between the duration of symptom, type of the disc herniation, pain intensity and clinical outcome. Results Mean age was 49.7 and male was predominant. Gait disturbance with mild to moderate pain was most common symptom in clinical features. Severe pain was shown in only 9 cases, and the other 12 cases experienced mild to moderate pain. Mean duration of myelopathy was 1.18 month. The mean JOA scores were 11.22 before surgery and 14.2 after surgery. The mean Nurick grades were 2.78 before treatment and 1.67 after treatment. Neurologic status of mild or moderate pain group on preoperative state is worse than that of severe pain group. The patients with duration of myelopathy symptom (<1 month) showed lower clinical improvement rate than the patients with myelopathy over 1 month. Patients with median type of disc herniation showed poorer neurological status than those with paramedian type of herniation in preoperative state. Conclusion Authors reviewed the clinical features and surgical outcome of the cervical myelopathy secondary to cervical soft disc herniation. We presumed that patients of more than one month of symptom duration, mild to moderate initial symptom would be related with better postoperative improvement rate. PMID:24757475

Park, Sung Joo; Kim, Min Ki; Lee, Sung Ho; Oh, In Ho

2013-01-01

196

Chiropractic Management and Rehabilitation of a 38-Year-Old Male with an L5-S1 Disc Herniation  

PubMed Central

Abstract Objective To present a chiropractic treatment plan for a patient with lumbar disc herniation including radicular symptoms below the knee. Clinical Features A 38-year-old male experienced lumbar disc herniation with radicular symptoms to the lower extremities, below the knee. Etiology of this episode included a traumatic injury which was complicated by chronic degenerative joint and disc changes. Intervention and Outcome The treatment regime included chiropractic spinal manipulation, modalities and exercise rehabilitation. Specific rehabilitation exercises were used during various stages of healing in an attempt to stabilize a potential surgical case. Goals of care were to alleviate pain, increase function, and decrease peripheralization related to disc herniation in this case. The patient reached a level of functional biomechanical stability over 15 weeks. Conclusion This case demonstrates that with proper management, rehabilitation of a patient with disc herniation can be reached in a short duration of time. PMID:19674637

Hammer, Christopher J.

2004-01-01

197

[Value of computed tomography in the differential diagnosis of postoperative lumbar disc herniation recurrence and fibrotic changes].  

PubMed

Plain computed tomography scans and after intravenous contrast enhancement were used to investigate a group of 26 patients after an operation for lumbar disc herniation with signs of failed back surgery syndrome. The diagnosis of relapsing disc herniation was established in 12 patients. It was confirmed by surgery in 10, while massive epidural fibrosis was discovered in two. Own experience with the above method, which is considered by the authors the most reliable, is presented. PMID:7976673

Burval, S; Nekula, J; Vaverka, M; Velísková, J; Klaus, E

1993-01-01

198

A Novel Approach to the Surgical Treatment of Lumbar Disc Herniations: Indications of Simple Discectomy and Posterior Transpedicular Dynamic Stabilization Based on Carragee Classification  

PubMed Central

Surgery of lumbar disc herniation is still a problem since Mixter and Barr. Main trouble is dissatisfaction after the operation. Today there is a debate on surgical or conservative treatment despite spending great effort to provide patients with satisfaction. The main problem is segmental instability, and the minimally invasive approach via microscope or endoscope is not necessarily appropriate solution for all cases. Microsurgery or endoscopy would be appropriate for the treatment of Carragee type I and type III herniations. On the other hand in Carragee type II and type IV herniations that are prone to develop recurrent disc herniation and segmental instability, the minimal invasive techniques might be insufficient to achieve satisfactory results. The posterior transpedicular dynamic stabilization method might be a good solution to prevent or diminish the recurrent disc herniation and development of segmental instability. In this study we present our experience in the surgical treatment of disc herniations. PMID:23653862

Ozer, A. F.; Keskin, F.; Oktenoglu, T.; Suzer, T.; Ataker, Y.; Gomleksiz, C.; Sasani, M.

2013-01-01

199

Perforation of the Pregnant Uterus during Laparoscopy for Suspected Internal Herniation after Gastric Bypass  

PubMed Central

We report perforations of a pregnant uterus during laparoscopy for suspected internal herniation after gastric bypass at 24 weeks of gestation. Abdominal access and gas insufflation were achieved by the use of a 12 mm optic trocar. An additional 5 mm trocar was positioned. The perforations were handled by suturing following laparotomy and mobilisation of the high located uterus. The uterine fundus was located in the subcostal area. Internal herniation was not verified. A cesarean section was made 6 weeks later due to acute low abdominal pain. During delivery the uterus was found normal. At 5 months of age the child has developed normal and seems healthy. Optical trocars should be used with caution for abdominal access during laparoscopy in pregnancy. Open access should probably be preferred in most cases. Accidental perforations of the uterine cavity may be handled in selected cases with simple closure even following the use of large trocars under close postoperative surveillance throughout the pregnancy. PMID:25548693

Harsem, N. K.; Røstad, S.; Mathisen, L. C.; Jacobsen, A. F.

2014-01-01

200

Acute gastric incarceration from thoracic herniation in pregnancy following laparoscopic antireflux surgery  

PubMed Central

Diaphragmatic hernia is a rare complication in pregnancy which due to misdiagnosis or management delays may be life-threatening. We report a case of a woman in the third trimester of pregnancy who presented with sudden onset of severe epigastric and thoracic pain radiating to the back. Earlier in the index pregnancy, she had undergone laparoscopic antireflux surgery (ARS) for a hiatus hernia because of severe gastro-oesophageal reflux. Owing to increasing epigastric pain a CT scan was carried out which diagnosed wrap disruption with gastric herniation into the thoracic cavity and threatened incarceration. This is, to our knowledge, the first report of severe adverse outcome after ARS during pregnancy, with acute intrathoracic gastric herniation. We recommend the avoidance of ARS in pregnancy, and the need to advise women undergoing ARS of the postoperative risks if pregnancy occurs within a few years of ARS. PMID:23378556

Brygger, Louise; Fristrup, Claus Wilki; Harbo, Frederik Severin Gråe; Jørgensen, Jan Stener

2013-01-01

201

Surgical technique for idiopathic spinal cord herniation: the Hammock method. Technical note.  

PubMed

Idiopathic spinal cord herniation is a rare disease, and surgical treatment is recommended for patients with motor deficits or progressive neurological symptoms. Surgery is performed to release and reposition the tethered spinal cord. In terms of repositioning and prevention of reherniation, various procedures have been proposed; enlargement of the ventral dural defect, primary closure of the defect with sutures, and insertion of a ventral patch for duraplasty. We treated 3 patients with idiopathic spinal cord herniation, using a ventral patch for duraplasty with an expanded polytetrafluoroethylene pericardial membrane (the Hammock method), and all 3 cases had good clinical outcome. The specific important technical aspects are described and illustrated. If this procedure is performed meticulously under the microscope by following the specific techniques, the Hammock method is safer and more effective for prevention of reherniation than simple enlargement of the dural defect. PMID:22522340

Akutsu, Hiroyoshi; Takada, Tomoya; Nakai, Kei; Tsuda, Kyoji; Sakane, Masataka; Aita, Ikuo; Matsumura, Akira

2012-01-01

202

Treatment of the degenerated intervertebral disc; closure, repair and regeneration of the annulus fibrosus.  

PubMed

Degeneration of the intervertebral disc (IVD) and disc herniation are two causes of low back pain. The aetiology of these disorders is unknown, but tissue weakening, which primarily occurs due to inherited genetic factors, ageing, nutritional compromise and loading history, is the basic factor causing disc degeneration. Symptomatic disc herniation mainly causes radicular pain. Current treatments of intervertebral disc degeneration and low back pain are based on alleviating the symptoms and comprise administration of painkillers or surgical methods such as spinal fusion. None of these methods is completely successful. Current research focuses on regeneration of the IVD and particularly on regeneration of the nucleus pulposus. Less attention has been directed to the repair or regeneration of the annulus fibrosus, although this is the key to successful nucleus pulposus, and therewith IVD, repair. This review focuses on the importance of restoring the function of the annulus fibrosus, as well as on the repair, replacement or regeneration of the annulus fibrosus in combination with restoration of the function of the nucleus pulposus, to treat low back pain. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24616324

Sharifi, Shahriar; Bulstra, Sjoerd K; Grijpma, Dirk W; Kuijer, Roel

2014-02-25

203

Higher risk of dural tears and recurrent herniation with lumbar micro-endoscopic discectomy  

Microsoft Academic Search

Existing studies on micro-endoscopic lumbar discectomy report similar outcomes to those of open and microdiscectomy and conflicting\\u000a results on complications. We designed a randomised controlled trial to investigate the hypothesis of different outcomes and\\u000a complications obtainable with the three techniques. 240 patients aged 18–65 years affected by posterior lumbar disc herniation\\u000a and symptoms lasting over 6 weeks of conservative management were randomised

Marco Teli; Alessio Lovi; Marco Brayda-Bruno; Antonino Zagra; Andrea Corriero; Fabrizio Giudici; Leone Minoia

2010-01-01

204

Blunt traumatic pericardial rupture and cardiac herniation with a penetrating twist: two case reports  

PubMed Central

Background Blunt Traumatic Pericardial Rupture (BTPR) with resulting cardiac herniation following chest trauma is an unusual and often fatal condition. Although there has been a multitude of case reports of this condition in past literature, the recurring theme is that of a missed injury. Its occurrence in severe blunt trauma is in the order of 0.4%. It is an injury that frequently results in pre/early hospital death and diagnosis at autopsy, probably owing to a combination of diagnostic difficulties, lack of familiarity and associated polytrauma. Of the patients who survive to hospital attendance, the mortality rate is in the order of 57-64%. Methods We present two survivors of BTPR and cardiac herniation, one with a delayed penetrating cardiac injury secondary to rib fractures. With these two cases and literature review, we hope to provide a greater awareness of this injury Conclusion BTPR and cardiac herniation is a complex and often fatal injury that usually presents under the umbrella of polytrauma. Clinicians must maintain a high index of suspicion for BTPR but, even then, the diagnosis is fraught with difficulty. In blunt chest trauma, patients should be considered high risk for BTPR when presenting with: Cardiovascular instability with no obvious cause Prominent or displaced cardiac silhouette and asymmetrical large volume pneumopericardium Potentially, with increasing awareness of the injury and improved use and availability of imaging modalities, the survival rates will improve and cardiac Herniation could even be considered the 5th H of reversible causes of blunt traumatic PEA arrest. PMID:20003497

2009-01-01

205

Horner's syndrome secondary to intervertebral disc herniation at the level of T1-2.  

PubMed

A 54-year-old Caucasian woman presented with a 6?week history of periscapular pain and a T1 radiculopathy associated with Horner's syndrome. MRI of her cervicothoracic spine revealed an intervertebral disc herniation at the level of T1-2. During investigation she experienced some improvement in her symptoms and a conservative approach was pursued. At 6?months her pain and radiculopathy had resolved, and there was mild residual ptosis. PMID:24903729

Spacey, Kate; Zaidan, Ammar; Dannawi, Zaher; Khazim, Rabi; Khazim, R; Dannawi, Zaher; Dannawi, Z

2014-01-01

206

Spontaneous intradural disc herniation with focal distension of the subarachnoid space in a dog.  

PubMed

Myelo-computed tomography of a paraparetic 14-year-old dog revealed subarachnoid distension with an intradural filling defect above the T13-L1 disc space. T12-L1 hemilaminectomy followed by durotomy allowed removal of a large piece of degenerated disc material that compressed the spinal parenchyma. Full return to function was achieved 10 days post-surgery. The distension was likely secondary to the intradural herniation, and is a rare and distinct finding. PMID:23633713

Barnoon, Itai; Chai, Orit; Srugo, Itai; Peeri, Dana; Konstantin, Lilach; Brenner, Ori; Shamir, Merav H

2012-11-01

207

Bipolar duraplasty: a new technique for reducing transcranial cerebral herniation to allow for definitive cranioplasty.  

PubMed

Large, full-thickness calvarial defects cause increased brain tissue compliance, often resulting in transient, transcranial herniation in the setting of normotensive intracranial pressures. Cranioplasty serves to protect the cerebrum from external injury, provide an aesthetic contour, and alleviate neurological symptoms. Traditional options for management include head elevation, osmotic diuresis, mild hyperventilation, durotomy with closure following fluid evacuation, expansile cranioplasty, lobectomy, and procedure abortion with prolonged helmet therapy. Patients treated conservatively with helmet therapy commonly are noncompliant and sustain repeated minor trauma to unprotected cerebral contents. Furthermore, recent literature suggests that early cranioplasty may improve outcomes and reduce costs. The authors present a novel solution, bipolar duraplasty, which allows safe, transient reduction of normotensive parenchymal herniation using bipolar electrocautery. The dura of the herniated sac is cauterized using a low-set, bipolar current in a series of sagittal and coronal lines, resulting in immediate contraction and reduction allowing for definitive cranioplasty. This new method was used in a patient with a 30-cm(2) frontal bone defect following resection of a right falcine atypical meningioma. In this scenario, bipolar duraplasty was performed free of complication, and the patient has remained asymptomatic and greatly satisfied for 1 year since the procedure. This technique might facilitate earlier cranioplasty, could be applied to a wide range of patients, and may afford better neurological outcomes at a reduced cost. PMID:21854117

Gordon, Chad R; Swanson, Edward W; Westvik, Tormod; Yaremchuk, Michael J

2011-11-01

208

Evolution of the nucleus?  

PubMed Central

The nucleus represents a major evolutionary transition. As a consequence of separating translation from transcription many new functions arose, which likely contributed to the remarkable success of eukaryotic cells. Here we will consider what has recently emerged on the evolutionary histories of several key aspects of nuclear biology; the nuclear pore complex, the lamina, centrosomes and evidence for prokaryotic origins of relevant players. PMID:24508984

Devos, Damien P; Gräf, Ralph; Field, Mark C

2014-01-01

209

Radiographic Markers of Femoroacetabular Impingement: Correlation of Herniation Pit and Femoral Bump with a Positive Cross-Over Ratio  

PubMed Central

Introduction. The goal of this study was to research the association of femoral bumps and herniation pits with the overlap-ratio of the cross-over sign. Methods. Pelvic X-rays and CT-scans of 2925 patients with good assessment of the anterior and the posterior acetabular wall and absence of neutral pelvic tilt were enrolled in the investigation. Finally pelvic X-rays were assessed for the presence of a positive cross-over sign, and CT-scans for a femoral bump or a herniation pit. Additionally, if a positive cross-over sign was discovered, the overlap-ratio was calculated. Results. A femoral bump was found in 53.3% (n = 1559), and a herniation pit in 27.2% (n = 796) of all hips. The overlap-ratio correlated positively with the presence of a femoral bump, while a negative correlation between the overlap-ratio and the presence of a herniation pit was found. The latter was significantly more often combined with a femoral bump than without. Conclusions. We detected an increased prevalence of femoral bump with increasing overlap-ratios of the cross-over sign indicating a relation to biomechanical stress. The observed decreased prevalence of herniation pits with increasing overlap-ratios could be explained by reduced mechanical stress due to nontightened iliofemoral ligament in the presence of retroversion of the acetabulum. PMID:24876972

Scheyerer, Max J.; Copeland, Carol E.; Stromberg, Jeffrey; Ruckstuhl, Thomas; Werner, Clément M. L.

2014-01-01

210

Nuclear rainbow scattering and nucleus-nucleus potential  

E-print Network

Elastic scattering of alpha-particle and some tightly-bound light nuclei has shown the pattern of rainbow scattering at medium energies, which is due to the refraction of the incident wave by a strongly attractive nucleus-nucleus potential. This review gives an introduction to the physics of the nuclear rainbow based essentially on the optical model description of the elastic scattering. Since the realistic nucleus-nucleus optical potential (OP) is the key to explore this interesting process, an overview of the main methods used to determine the nucleus-nucleus OP is presented. The refractive rainbow-like structures observed in other quasi-elastic scattering reactions have also been discussed. Some evidences for the refractive effect in the elastic scattering of unstable nuclei are presented and perspectives for the future studies are discussed.

Dao T. Khoa; W. von Oertzen; H. G. Bohlen; S. Ohkubo

2006-12-21

211

Gatekeepers of the Nucleus  

NSDL National Science Digital Library

Nuclear pore complexes (NPCs) form the site for entry and exit from the nucleus. A convergence of studies have defined the physical framework for the nuclear transport mechanism. This includes definition of the soluble transport machinery required for protein and RNA movement, x-ray structure analysis of transport factors, definitive compositional analysis of yeast NPCs, and documentation of the relative steady state arrangement of NPC components within the portal. With this information, researchers are now in the exciting position to examine the dynamic interplay between shuttling transport factors and the static pore complex.

Susan Wente (Washington University School of Medicine;Department of Cell Biology and Physiology)

2000-05-26

212

Nucleus from String Theory  

E-print Network

In generic holographic QCD, we find that baryons are bound to form a nucleus, and that its radius obeys the empirically-known mass number (A) dependence r A^{1/3} for large A. Our result is robust, since we use only a generic property of D-brane actions in string theory. We also show that nucleons are bound completely in a finite volume. Furthermore, employing a concrete holographic model (derived by Hashimoto, Iizuka, and Yi, describing a multi-baryon system in the Sakai-Sugimoto model), the nuclear radius is evaluated as O(1) x A^{1/3} [fm], which is consistent with experiments.

Koji Hashimoto; Takeshi Morita

2011-03-29

213

The pathophysiology, classification, treatment, and prognosis of a spontaneous thoracic spinal cord herniation: A case study with literature review  

PubMed Central

Background: Spinal cord herniation was first described in 1974. It generally occurs in middle-aged adults in the thoracic spine. Symptoms typically include back pain and progressive paraparesis characterized by Brown-Séquard syndrome. Surgical reduction of the hernia improves the attendant symptoms and signs, even in patients with longstanding deficits. Case Description: A 66-year-old female with back pain for 7 years, accompanied by paresthesias and a progressive paraparesis, underwent a thoracic MRI which documented a ventral spinal cord herniation at the T4 level. Following a laminectomy, with reduction of the hernia and ventral dural repair, the patient improved. Conclusion: Herniation of the thoracic cord, documented on MR, may produce symptomatic paraparesis which may resolve following laminectomy with ventral dural repair.

De Souza, Rodrigo Becco; De Aguiar, Guilherme Brasileiro; Daniel, Jefferson Walter; Veiga, José Carlos Esteves

2014-01-01

214

Management of Chronic Pain of Cervical Disc Herniation and Radiculitis with Fluoroscopic Cervical Interlaminar Epidural Injections  

PubMed Central

Study Design: A randomized, double-blind, active controlled trial. Objective: To evaluate the effectiveness of cervical interlaminar epidural injections of local anesthetic with or without steroids in the management of chronic neck pain and upper extremity pain in patients with disc herniation and radiculitis. Summary of Background Data: Epidural injections in managing chronic neck and upper extremity pain are commonly employed interventions. However, their long-term effectiveness, indications, and medical necessity, of their use and their role in various pathologies responsible for persistent neck and upper extremity pain continue to be debated, even though, neck and upper extremity pain secondary to disc herniation and radiculitis, is described as the common indication. There is also paucity of high quality literature. Methods: One-hundred twenty patients were randomly assigned to one of 2 groups: Group I patients received cervical interlaminar epidural injections of local anesthetic (lidocaine 0.5%, 5 mL); Group II patients received 0.5% lidocaine, 4 mL, mixed with 1 mL of nonparticulate betamethasone. Primary outcome measure was ? 50 improvement in pain and function. Outcome assessments included Numeric Rating Scale (NRS), Oswestry Disability Index (ODI), opioid intake, employment, and changes in weight. Results: Significant pain relief and functional status improvement (? 50%) was demonstrated in 72% of patients who received local anesthetic only and 68% who received local anesthetic and steroids. In the successful group of participants, significant improvement was illustrated in 77% in local anesthetic group and 82% in local anesthetic with steroid group. Conclusions: Cervical interlaminar epidural injections with or without steroids may provide significant improvement in pain and function for patients with cervical disc herniation and radiculitis. PMID:22859902

Manchikanti, Laxmaiah; Cash, Kimberly A.; Pampati, Vidyasagar; Wargo, Bradley W.; Malla, Yogesh

2012-01-01

215

Meson multiplicity versus energy in relativistic nucleus-nucleus collisions  

NASA Technical Reports Server (NTRS)

A systematic study of meson multiplicity as a function of energy at energies up to 100 GeV/u in nucleus-nucleus collisions has been made, using cosmic-ray data in nuclear emulsion. The data are consistent with simple nucleon-nucleon superposition models. Multiplicity per interacting nucleon in AA collisions does not appear to differ significantly from pp collisions.

Atwater, T. W.; Freier, P. S.

1986-01-01

216

Electric quadrupole excitations in relativistic nucleus-nucleus collisions  

NASA Technical Reports Server (NTRS)

Calculations are presented for electric quadrupole excitations in relativistic nucleus-nucleus collisions. The theoretical results are compared to an extensive data set and it is found that electric quadrupole effects provide substantial corrections to cross sections, especially for heavier nuclei.

Norbury, John W.

1989-01-01

217

Traumatic Right Diaphragmatic Rupture Combined with Avulsion of the Right Kidney and Herniation of the Liver into the Thorax  

PubMed Central

Right-sided diaphragmatic rupture is less common and more difficult to diagnose than left-sided lesion. It is rarely combined with the herniation of the abdominal organs into the thorax. High level of suspicion is the key to early diagnosis, and a delay in diagnosis is implicated with a considerable risk of mortality and morbidity. We experienced a case of right-sided diaphragmatic rupture combined with complete avulsion of the right kidney and herniation of the liver into the thoracic cavity. PMID:22263130

Kim, Chong Wook; Park, Chong-Bin; Ahn, Jae Hong

2011-01-01

218

Spontaneous Spinal Cord Herniation: MR Imaging and Clinical Features in Six Cases  

Microsoft Academic Search

\\u000a Abstract\\u000a \\u000a \\u000a Background and Purpose:\\u000a   Spontaneous spinal cord herniation (SSCH) is a rare but important differential diagnosis of spinal cord disorder. The aim\\u000a of this study was to evaluate the topography and lesion pattern in six patients with SSCH by magnetic resonance imaging (MRI)\\u000a and their correlation with clinical symptoms.\\u000a \\u000a \\u000a \\u000a \\u000a Material and Methods:\\u000a   MRI was evaluated according to intramedullary hyperintense signal

Stella Blasel; Elke Hattingen; Horst Baas; Friedhelm Zanella; Stefan Weidauer

2008-01-01

219

Management of Cerebellar Tonsillar Herniation following Lumbar Puncture in Idiopathic Intracranial Hypertension  

PubMed Central

Lumbar puncture is performed routinely for diagnostic and therapeutic purposes in idiopathic intracranial hypertension, despite lumbar puncture being classically contraindicated in the setting of raised intracranial pressure. We report the case of a 30-year-old female with known idiopathic intracranial hypertension who had cerebellar tonsillar herniation following therapeutic lumbar puncture. Management followed guidelines regarding treatment of traumatic intracranial hypertension, including rescue decompressive craniectomy. We hypothesize that the changes in brain compliance that are thought to occur in the setting of idiopathic intracranial hypertension are protective against further neuronal injury due to axonal stretch following decompressive craniectomy.

Hoffman, Kenneth R.; Chan, Sean W.; Hughes, Andrew R.; Halcrow, Stephen J.

2015-01-01

220

Higher preoperative Oswestry Disability Index is associated with better surgical outcome in upper lumbar disc herniations  

Microsoft Academic Search

To evaluate the surgical outcome in terms of functional and subjective recovery, patients who needed discectomies at L1–L2,\\u000a L2–L3 and L3–L4 levels were compared with an age and sex-matched group of patients who required L4–L5 and L5–S1 discectomies.\\u000a We prospectively enrolled 50 consecutive patients, referred to our center, who had L1–L2, L2–L3 and L3–L4 herniations and\\u000a required surgical intervention. Likewise,

Hooshang Saberi; Arash Vatankhahan Isfahani

2008-01-01

221

A comparison of minimally invasive techniques in percutaneous treatment of lumbar herniated discs. A review.  

PubMed

Low back pain is the commonest spine disease causing absence from work in developed countries. Low back pain with classical irradiation along the course of the nerve root affected is more frequently due to disc disease. In 60-80% of patients with herniated disc, radicular symptoms disappear with conservative treatment after about six weeks, the remainder are treated surgically with a 2-6% of incidence of true recurrence of herniation post-intervention and with failed back surgery syndrome in 15% of cases. Recently minimally invasive techniques have developed as "alternative" treatments to surgical intervention. This review aimed to assess the pathogenesis of low back pain caused by lumbar disc hernia as a basis for action of minimally invasive techniques; to illustrate the techniques already used or currently in use, to compare them in technical guidance, indications and complications, exposing for each of them the inclusion/exclusion criteria in enrolling patients and the imaging guide technique of choice. Minimally invasive techniques can be a valuable alternative to traditional surgery with low cost, low risk of complications, easy feasibility, and in the event of failure they do not exclude subsequent surgery. PMID:24206960

Guarnieri, G; Vassallo, P; Pezzullo, M G; Laghi, F; Zeccolini, F; Ambrosanio, G; Galasso, R; Muto, M; Izzo, R

2009-03-23

222

Percutaneous endoscopic cervical discectomy for discogenic cervical headache due to soft disc herniation.  

PubMed

A discogenic cervical headache is a subtype of cervicogenic headache (CEH) that arises from a degenerative cervical disc abnormality. The purpose of this study was to evaluate the clinical outcome of percutaneous endoscopic cervical discectomy (PECD) for patients with chronic cervical headache due to soft cervical disc herniation. Seventeen patients underwent PECD for intractable headache. The inclusion criteria were soft disc herniation without segmental instability, proven by both local anesthesia and provocative discography for headache unresponsive to conservative treatment. The mean follow-up period was 37.6 months. Fifteen of the 17 patients (88.2%) showed successful outcomes based on the Macnab criteria. Pain scores on a visual analog scale (VAS) improved from a preoperative mean of 8.35 +/- 0.79 to 2.12 +/- 1.17, postoperatively (P < 0.01). The mean disc height decreased from 6.81 +/- 1.08 to 5.98 +/- 1.07 mm (P < 0.01). There was no newly developed segmental instability or spontaneous fusion on follow-up radiography. In conclusion, PECD appears to be effective for chronic severe discogenic cervical headache under strict inclusion criteria. PMID:16133482

Ahn, Y; Lee, S H; Chung, S E; Park, H S; Shin, S W

2005-12-01

223

Comparison of potential models of nucleus-nucleus bremsstrahlung  

NASA Astrophysics Data System (ADS)

At low photon energies, the potential models of nucleus-nucleus bremsstrahlung are based on electric transition multipole operators, which are derived either only from the nuclear current or only from the charge density by making the long-wavelength approximation and using the Siegert theorem. In the latter case, the bremsstrahlung matrix elements are divergent and some regularization techniques are used to obtain finite values for the bremsstrahlung cross sections. From an extension of the Siegert theorem, which is not based on the long-wavelength approximation, a new potential model of nucleus-nucleus bremsstrahlung is developed. Only convergent integrals are included in this approach. Formal links between bremsstrahlung cross sections obtained in these different models are made. Furthermore, three different ways to calculate the regularized matrix elements are discussed and criticized. Some prescriptions for a proper implementation of the regularization are deduced. A numerical comparison between the different models is done by applying them to the ? +? bremsstrahlung.

Dohet-Eraly, J.; Baye, D.

2014-09-01

224

Treatment of contained lumbar disc herniations using radiofrequency assisted micro-tubular decompression and nucleotomy: four year prospective study results  

PubMed Central

Background Patients with radiculopathy caused by contained disc herniations are less likely to have good outcomes following discectomy surgery than patients with disc herniations that are not contained. The author presents his 4-year results from a prospective trial regarding the efficacy and safety of a tubular transforaminal radiofrequency-assisted manual decompression and annulus modulation of contained disc herniations in 58 patients. Methods Fifty-eight patients with lumbar radiculopathy due to a contained disc herniation were enrolled in a prospective clinical study. Visual analog scores (VAS) for back pain and leg pain, quality of life assessment, Macnab criteria, and SF-12 were collected from patients before treatment, at 2-years and 4-years post-treatment. Results At 4 years, results were obtained from 47 (81%) of patients. Compared to mean pre- treatment assessments, mean 4-year VAS for back pain improved from 8.6 to 2.3 points, and mean VAS for leg pain improved from 7.8 to 2.3. Eighty-three percent of respondents reported that they were “satisfied” or “very satisifed” with their quality of life at 4-years as per SF-12. At 4 years, recurrence was noted in 3 (6.4%) of respondents and no complications were reported. Conclusions The 2-year and 4-year study results are nearly identical, suggesting durable benefit out to 4 years. These results also suggest that in carefully selected patients with sustained contained disc herniations who have failed conservative treatments, manual decompression combined with radiofrequency-assisted decompression and annulus modulation are very likely to have good outcomes 4 years post-treatment.

2014-01-01

225

Enhancing tissue repair in annulus fibrosus defects of the intervertebral disc: analysis of a bio-integrative annulus implant in an in-vivo ovine model.  

PubMed

Annulus fibrosus repair techniques for the intervertebral disc (IVD) address the unsolved problem of reherniation after IVD herniation and might facilitate the development of nucleus pulposus replacement techniques for IVD diseases. This study investigates the suitability of a bio-integrative annulus implant.Standardized box defects were applied to the annulus L3/4 and L4/5 of 16 sheep, followed by randomized insertion of the textile polyglycolic acid/polyvinylidene fluoride annulus implant in one of the defects. Explantation was conducted after 2, 6 and 12 weeks, followed by provocative pressure testing and histological analysis. At 2 weeks' follow-up, all specimens of the control defect group demonstrated uncontained herniated nucleus pulposus tissue in the annulus defects. For the treated specimens, the annulus implant consistently provided an effective barrier for herniating nucleus pulposus tissue, with no implant dislocation at all time-points. After 2 weeks, a homogeneous cell infiltration of the annulus implant was observed, leading to a progressive directional matrix build-up. Repair tissue thickness was significantly stronger with the annulus implant at all follow-ups (p < 0.01). No pronounced foreign body reaction and no difference in the amount of supra-annular scar tissue over the defect sites were observed. The implantation procedure inflicted annulus damage adjacent to the defect. At later time-points, however, no difference in comparison with the control defect group was evident. The investigated biointegrative annulus implant showed promising results with regard to biointegration, enhancement of repair tissue and function as a mechanical barrier in an ovine model. © 2013 The Authors. Journal of Tissue Engineering and Regenerative Medicine published by John Wiley & Sons, Ltd. PMID:24227682

Hegewald, Aldemar Andres; Medved, Fabian; Feng, Daxiong; Tsagogiorgas, Charalambos; Beierfuß, Anja; Schindler, Genevieve Ama Kyremaa; Trunk, Marcus; Kaps, Christian; Mern, Demissew Shenegelegn; Thomé, Claudius

2013-11-12

226

Comparative Evaluation of Oxygen-Ozone Therapy and Combined Use of Oxygen-Ozone Therapy with Percutaneous Intradiscal Radiofrequency Thermocoagulation for the Treatment of Lumbar Disc Herniation  

Microsoft Academic Search

AimTo compare the efficacy of oxygen-ozone therapy and the combined use of oxygen-ozone therapy with percutaneous intradiscal radiofrequency thermocoagulation (PIRFT) for the treatment of contained lumbar disc herniation.

Sujeet Gautam; V. Rastogi; Ankur Jain; A. P. Singh

2011-01-01

227

Repair, regenerative and supportive therapies of the annulus fibrosus: achievements and challenges  

PubMed Central

Lumbar discectomy is a very effective therapy for neurological decompression in patients suffering from sciatica due to hernia nuclei pulposus. However, high recurrence rates and persisting post-operative low back pain in these patients require serious attention. In the past decade, tissue engineering strategies have been developed mainly targeted to the regeneration of the nucleus pulposus (NP) of the intervertebral disc. Accompanying techniques that deal with the damaged annulus fibrous are now increasingly recognised as mandatory in order to prevent re-herniation to increase the potential of NP repair and to confine NP replacement therapies. In the current review, the requirements, achievements and challenges in this quickly emerging field of research are discussed. PMID:19104850

Bron, Johannes Leendert; Helder, Marco N.; Meisel, Hans-Jorg; Van Royen, Barend J.

2008-01-01

228

Co-existence of L5-S1 disc herniation and conus medullaris ependymoma  

PubMed Central

INTRODUCTION The lumbar disc herniations are seen very common than spinal ependymomas in the neurosurgery polyclinic routine. PRESENTATION OF CASE In our case, both pathologies were seen at the most frequently located levels compatible with the literature. Aim of this case report is, to remind once more that, different pathologies can be found at the same time in a single patient; differential diagnosis must be done very carefully. DISCUSSION The routine Computed Tomography (CT) imaging for low back pain can not show the conus medullaris pathology. Spinal tumors or other similar pathologies should be kept in mind for differential diagnosis. A good medical history and a good physical examination must be completed before the final diagnosis. CONCLUSION Viewing of spinal canal with Magnetic Resonance Imaging (MRI) will be useful for the patients who we intend to do disc surgery. PMID:25460457

Mino?lu, Mustafa; Akkol, ?smail; Özdemir, Nail; Y?ld?r?m, Levent

2014-01-01

229

The Influence of Obesity on the Outcome of Treatment of Lumbar Disc Herniation  

PubMed Central

Background: Questions remain as to the effect that obesity has on patients managed for symptomatic lumbar disc herniation. The purpose of this study was to determine if obesity affects outcomes following the treatment of symptomatic lumbar disc herniation. Methods: An as-treated analysis was performed on patients enrolled in the Spine Patient Outcomes Research Trial for the treatment of lumbar disc herniation. A comparison was made between patients with a body mass index of <30 kg/m2 (nonobese) (n = 854) and those with a body mass index of ?30 kg/m2 (obese) (n = 336). Baseline patient demographic and clinical characteristics were documented. Primary and secondary outcomes were measured at baseline and at regular follow-up time intervals up to four years. The difference in improvement from baseline between operative and nonoperative treatment was determined at each follow-up period for both groups. Results: At the time of the four-year follow-up evaluation, improvements over baseline in primary outcome measures were significantly less for obese patients as compared with nonobese patients in both the operative treatment group (Short Form-36 physical function, 37.3 compared with 47.7 points [p < 0.001], Short Form-36 bodily pain, 44.2 compared with 50.0 points [p = 0.005], and Oswestry Disability Index, ?33.7 compared with ?40.1 points [p < 0.001]) and the nonoperative treatment group (Short Form-36 physical function, 23.1 compared with 32.0 points [p < 0.001] and Oswestry Disability Index, ?21.4 compared with ?26.1 points [p < 0.001]). The one exception was that the change from baseline in terms of the Short Form-36 bodily pain score was statistically similar for obese and nonobese patients in the nonoperative treatment group (30.9 compared with 33.4 points [p = 0.39]). At the time of the four-year follow-up evaluation, when compared with nonobese patients who had been managed operatively, obese patients who had been managed operatively had significantly less improvement in the Sciatica Bothersomeness Index and the Low Back Pain Bothersomeness Index, but had no significant difference in patient satisfaction or self-rated improvement. In the present study, 77.5% of obese patients and 86.9% of nonobese patients who had been managed operatively were working a full or part-time job. No significant differences were observed in the secondary outcome measures between obese and nonobese patients who had been managed nonoperatively. The benefit of surgery over nonoperative treatment was not affected by body mass index. Conclusions: Obese patients realized less clinical benefit from both operative and nonoperative treatment of lumbar disc herniation. Surgery provided similar benefit over nonoperative treatment in obese and nonobese patients. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence. PMID:23192403

Rihn, Jeffrey A.; Kurd, Mark; Hilibrand, Alan S.; Lurie, Jon; Zhao, Wenyan; Albert, Todd; Weinstein, James

2013-01-01

230

Spondylocostal dysostosis with tetralogy of Fallot and herniation of the spleen through the diaphragm.  

PubMed

Spondylocostal dysostosis (SCD) is a very rare syndrome characterized by vertebral malformation and rib deformity. Some of the patients with SCD have other birth defects in the central nervous system, the genitourinary tract, diaphragm or heart and so forth. There have been reported SCD with complex congenital heart disease, such as pulmonary atresia, double outlet right ventricle, and d-transposition of great arteries. However, there have been no reported SCD patients with confirmed tetralogy of Fallot (TOF). Here, a patient with SCD having a very rare combination of rib defects on the right side and left-sided scoliosis, tetralogy of Fallot, and diaphragmatic spleen herniation, which had not been reported before, was described. PMID:24666313

Nagasawa, Hiroyuki; Koyama, Toshinari; Sasai, Hideo; Kohno, Yoshinori; Yamamoto, Yutaka; Kondo, Masashi; Sugawara, Masami; Terazawa, Daisuke; Miura, Ryosuke

2014-08-01

231

Acute paraplegia secondary to thoracic disc herniation of the adjacent segment following thoracolumbar fusion and instrumentation.  

PubMed

Proximal junctional disease is a well-recognized postoperative phenomenon in adults who are undergoing long thoracolumbar fusion and instrumentation, and is attributed to increased a junctional stress concentration. In general, the onset of symptoms in these patients is insidious and the disease progresses slowly. We report on a contrary case of rapidly progressing paraplegia secondary to acute disc herniation at the proximal adjacent segment after long posterior thoracolumbar fusion with cement augmentation at the upper instrumented vertebra and the supra-adjacent vertebra. The patient was treated with a discectomy through the costo-transverse approach combined with extension of the posterior instrumentation. The patient's neurological status improved markedly. Stress concentration at the proximal junction disc space may have caused accelerated disc degeneration which in turn lead to this complication. PMID:23508671

Badra, Mohammad Ibrahim; Assaker, Richard; Musharrafieh, Ramzi Sharif

2013-03-01

232

Dorsal Extradural Lumbar Disc Herniation Causing Cauda Equina Syndrome : A Case Report and Review of Literature  

PubMed Central

A 73-year-old male presented with a rare dorsally sequestrated lumbar disc herniation manifesting as severe radiating pain in both leg, progressively worsening weakness in both lower extremities, and urinary incontinence, suggesting cauda equina syndrome. Magnetic resonance imaging suggested the sequestrated disc fragment located in the extradural space at the L4-L5 level had surrounded and compressed the dural sac from the lateral to dorsal sides. A bilateral decompressive laminectomy was performed under an operating microscope. A large extruded disc was found to have migrated from the ventral aspect, around the thecal sac, and into the dorsal aspect, which compressed the sac to the right. After removal of the disc fragment, his sciatica was relieved and the patient felt strength of lower extremity improved. PMID:20379476

Lee, Sang-Ho; Arbatti, Nikhil J.

2010-01-01

233

Herniated Disk  

MedlinePLUS

... Yes, exercises can be helpful. Begin by stretching. Bend over forward and bend to the sides. Start these exercises after your ... back by reducing the pressure on your disk Bend your knees and hips when you lift something, ...

234

Herniated disk  

MedlinePLUS

... diet and exercise are very important for improving back pain. Physical therapy is important for nearly everyone with ... with treatment. But you may have long-term back pain even after treatment. It may take several months ...

235

Chiropractic/Rehabilitative Management of Post-Surgical Disc Herniation: A Retrospective Case Report  

PubMed Central

Abstract Objective To discuss management of postsurgical lumbar disc herniation using a program of chiropractic manipulation and an active rehabilitation program. Clinical Features The patient was a 54-year-old Caucasian male with a history of acute low back pain and left sciatic pain down the left posterior thigh and lateral calf and numbness in the dorsum of the left foot. Prior medical intervention included treatment with steroid anti-inflammatory drugs and lumbar microdiscectomy surgery, with incomplete resolution of his symptoms. The patient was unable to walk without pain or return to normal activities of daily living. He was antalgic in flexion. His lumbar range of motion was restricted in flexion and extension. He exhibited a positive straight leg raise and exhibited foot drop on the left. Intervention and Outcome The treatment plan and intervention consisted of patient education on proper posture and proper bending and lifting techniques. Rehabilitative exercise began in the office and progressed to home based therapy and exercises. He noticed a decrease in his signs and symptoms after seven visits. Active rehabilitation was continued with the goal of returning lumbar spinal extensor strength. He was released to home therapy and supportive chiropractic care with continued positive response. Conclusion Management of postsurgical lumbar disc herniation with chiropractic and active rehabilitation is discussed. Spinal deconditioning and a weakness of the lumbar spinal extensor muscles appeared to be related to the patient's symptoms. Patient education on proper posture, proper lifting techniques, core stabilization exercises, active strengthening exercise and chiropractic manipulation appeared effective in this case. PMID:19674632

Estadt, Gary M.

2004-01-01

236

Transport of the influenza virus genome from nucleus to nucleus.  

PubMed

The segmented genome of an influenza virus is encapsidated into ribonucleoprotein complexes (RNPs). Unusually among RNA viruses, influenza viruses replicate in the nucleus of an infected cell, and their RNPs must therefore recruit host factors to ensure transport across a number of cellular compartments during the course of an infection. Recent studies have shed new light on many of these processes, including the regulation of nuclear export, genome packaging, mechanisms of virion assembly and viral entry and, in particular, the identification of Rab11 on recycling endosomes as a key mediator of RNP transport and genome assembly. This review uses these recent gains in understanding to describe in detail the journey of an influenza A virus RNP from its synthesis in the nucleus through to its entry into the nucleus of a new host cell. PMID:24104053

Hutchinson, Edward C; Fodor, Ervin

2013-10-01

237

Is there any relationship between proinflammatory mediator levels in disc material and myelopathy with cervical disc herniation and spondylosis? A non-randomized, prospective clinical study  

PubMed Central

The proinflammatory mediator (PIM) levels were assessed in surgically removed samples of herniated cervical intervertebral discs. The objective of this study was to investigate if there is a correlation between the levels of PIMs in disc material and myelopathy associated with cervical intervertebral disc herniation and spondylosis. The role of proinflammatory mediators in the degeneration of intervertebral disc and the inflammatory effects of disc herniations on radicular pain has been previously published. However, the possible relationship between PIMs and myelopathy related to cervical disc herniation and spondylosis has not been investigated before. Thirty-two patients undergoing surgery for cervical disc herniation and spondylosis were investigated. Surgically obtained disc materials, stored at 70°C, were classified into two groups: cervical disc herniation alone or with myelopathy. Biochemical preparation and solid phase enzyme amplified sensitivity immunoassay (ELISIA) analysis of the samples were performed to assess the concentration of mediators in the samples. Very similar values of interleukin-6 were found in both groups whereas the concentrations of mediators were significantly higher in myelopathy group. This study has demonstrated that PIMs are involved in cervical intervertebral disc degeneration with higher concentrations in the samples associated with myelopathy. PMID:17476536

Asir, Alparslan; Cetinkal, Ahmet; Gedik, Nursal; Kutlay, Ahmet Murat; Çolak, Ahmet; Kurtar, Sedat; Simsek, Hakan

2007-01-01

238

SPINE Volume 29, Number 12, pp 12991307 2004, Lippincott Williams & Wilkins, Inc.  

E-print Network

Engineered Nucleus Pulposus Tissue Formed on a Porous Calcium Polyphosphate Substrate Cheryle A. Se´guin, MSc engineering approach. Objectives. To determine if a construct composed of nucleus pulposus tissue, MD* Study Design. This study describes the formation of nucleus pulposus tissue using a novel tissue

Waldman, Stephen D.

239

Cometary nucleus and active regions  

NASA Technical Reports Server (NTRS)

On the basis of the icy conglomerate model of cometary nuclei, various observations demonstrate the spotted nature of many or most nuclei, i.e., regions of unusual activity, either high or low. Rotation periods, spin axes and even precession of the axes are determined. The observational evidence for variations in activity over the surfaces of cometary nuclei are listed and discussed. On June 11 the comet IRAS-ARAKI-ALCOCK approached the Earth to a distance of 0.031 AU, the nearest since C/Lexell, 1770 I, providing a unique opportunity for near-nucleus observations. Preliminary analysis of these images establishes the spin axis of the nucleus, with an oblioquity to the orbit plane of approximately 50 deg, and a lag angle of sublimation approximately 35 deg from the solar meridian on the nucleus. Asymmetries of the inner coma suggests a crazy-quilt distribution of ices with differing volatility over the surface of the nucleus. The observations of Comet P/Homes 1892 III, exhibiting two 8-10 magnitude bursts, are carefully analyzed. The grazing encounter produced, besides the first great burst, an active area on the nucleus, which was rotating retrograde with a period of 16.3hr and inclination nearly 180 deg. After the first burst the total magnitude fell less than two magnitudes from November 7 to November 30 (barely naked eye) while the nuclear region remained diffuse or complex, rarely if ever showing a stellar appearance. The fading was much more rapid after the second burst. The grazing encounter distributed a volume of large chunks in the neighborhood of the nucleus, maintaining activity for weeks.

Whipple, F. L.

1984-01-01

240

Formin’ actin in the nucleus  

PubMed Central

Many if not most proteins can, under certain conditions, change cellular compartments, such as, for example, shuttling from the cytoplasm to the nucleus. Thus, many proteins may exert functions in various and very different subcellular locations, depending on the signaling context. A large amount of actin regulatory proteins has been detected in the mammalian cell nucleus, although their potential roles are much debated and are just beginning to emerge. Recently, members of the formin family of actin nucleators were also reported to dynamically localize to the nuclear environment. Here we discuss our findings that specific diaphanous-related formins can promote nuclear actin assembly in a signal-dependent manner. PMID:24637338

Baarlink, Christian; Grosse, Robert

2014-01-01

241

Hadronic Reaction Zones in Relativistic Nucleus-Nucleus Collisions  

NASA Astrophysics Data System (ADS)

On the basis of the proposed algorithm for calculation of the hadron reaction rates, the space-time structure of the relativistic nucleus-nucleus collisions is studied. The reaction zones and the reaction frequencies for various types of reactions are calculated for Alternating Gradient Synchrotron (AGS) and Super Proton Synchrotron (SPS) energies within the microscopic transport model. The relation of the reaction zones to the kinetic and chemical freeze-out processes is discussed. It is shown that the space-time freeze-out layer is most extended in time in the central region, while, especially for higher collision energies, the layer becomes very narrow at the sides. The parametrization of freeze-out hypersurface in the form of specific hyperbola of constant proper time was confirmed. The specific characteristic time moments of the fireball evolution are introduced. It is found that the time of the division of a reaction zone into two separate parts does not depend on the collision energy. Calculations of the hadronic reaction frequency show that the evolution of nucleus-nucleus collision can be divided into two hadronic stages.

Anchishkin, D.; Vovchenko, V.; Yezhov, S.

2013-06-01

242

Case report: The operation for the lumbar disk herniation just after cesarean delivery in the third trimester of pregnancy  

PubMed Central

INTRODUCTION Low back pain is common during pregnancy. However, the incidence of symptomatic lumbar disc herniation during pregnancy is very rare. We report a case of lumbar disc herniation underwent discectomy just after cesarean delivery in the third trimester of pregnancy. PRESENTATION OF CASE A 33-year-old woman presented at 32 weeks gestation. She had a low back pain and the left-sided leg pain below the knee. At 34 weeks gestation, she had severe weakness of the left extension halluces longus, left ankle dorsiflexion. MRI showed a large disc herniation at L4/5 expanded to the spinal canal more. The cesarean delivery was performed in the supine position. The patient was then turned to a prone position, and a left L4/5 discectomy was performed. But the day after surgery, she had a severe low back pain and the right leg pain below the knee. MRI showed a disc herniation at L4/5 on the right side of the spinal canal. At 6 days after the first surgery, a right L4/5 discectomy was performed. In the immediate postoperative period, the patient experienced complete relief of the right leg pain. DISCUSSION It is necessary to cooperate with a pediatrician, an obstetrician, and an anethesiologists. For obtaining the best outcome on mother and child, it is important to discuss in advance to be able to respond quickly for changeable situation. CONCLUSION It is necessary to conduct the operation under pregnancy in consideration of the great influence on mother and child. PMID:25437670

Ochi, Hironori; Ohno, Ryuichi; Kubota, Mitsuaki; Hanyu, Ryo; Sakai, Kensuke; Sugawara, Yu; Mukasa, Fumihiro; Kaneko, Kazuo

2014-01-01

243

Describing a new syndrome in L5-S1 disc herniation: Sexual and sphincter dysfunction without pain and muscle weakness  

PubMed Central

Context: Little seems to be known about the sexual dysfunction (SD) in lumbar intervertebral disc herniation. Aims: Investigation of sexual and sphincter dysfunction in patient with lumbar disc hernitions. Settings and Design: A retrospective analysis. Materials and Methods: Sexual and sphincter dysfunction in patients admitted with lumbar disc herniations between September 2012-March 2014. Statistical Analysis Used: Statistical analysis was performed using the Predictive Analytics SoftWare (PASW) Statistics 18.0 for Windows (Statistical Package for the Social Sciences, SPSS Inc., Chicago, Illinois). The statistical significance was set at P < 0.05. The Wilcoxon signed ranks test was used to evaluate the difference between patients. Results: Four patients with sexual and sphincter dysfunction were found, including two women and two men, aged between 20 and 52 years. All of them admitted without low back pain. In addition, on neurological examination, reflex and motor deficit were not found. However, almost all patients had perianal sensory deficit and sexual and sphincter dysfunction. Magnetic resonance imaging (MRI) of three patients displayed a large extruded disc fragment at L5-S1 level on the left side. In fourth patient, there were not prominent disc herniations. There was not statistically significant difference between pre-operative and post-operative sexual function, anal-urethral sphincter function, and perianal sensation score. A syndrome in L5-S1 disc herniation with sexual and sphincter dysfunction without pain and muscle weakness was noted. We think that it is crucial for neurosurgeons to early realise that paralysis of the sphincter and sexual dysfunction are possible in patients with lumbar L5-S1 disc disease. Conclusion: A syndrome with perianal sensory deficit, paralysis of the sphincter, and sexual dysfunction may occur in patients with lumbar L5-S1 disc disease. The improvement of perianal sensory deficit after surgery was counteracted by a trend toward disturbed sexual function. Further researches are needed to explore the extent of this problem.

Akca, Nezih; Ozdemir, Bulent; Kanat, Ayhan; Batcik, Osman Ersagun; Yazar, Ugur; Zorba, Orhan Unal

2014-01-01

244

Cervical Myelopathy Caused by Disc Herniation at the Segment of Existing Osteochondroma in a Patient with Hereditary Multiple Exostoses  

PubMed Central

Hereditary multiple exostoses (HME) is a benign hereditary disorder characterized by multiple osteochondromas. Osteochondroma appears occasionally in the spinal column as a part of HME. A 37-year-old man presented with a history of HME and cervical compressive myelopathy caused by intraspinal osteochondroma arising from the lamina of the C5 and disc herniation at the C5-6. He was treated by open-door laminoplasty at the C5 and C6 with excision of the tumor. The neurological symptoms were immediately relieved after surgery. Magnetic resonance images demonstrated a sufficient decompression of the spinal cord with a spontaneous regression of the herniated disc at one year after surgery. There was no recurrence of the tumor and no appearance of kyphosis and segmental instability of the cervical spine on postoperative imaging studies for three years after surgery. The patient could be successfully treated by laminoplasty with excision of the tumor and without removal of the herniated disc. PMID:25558330

Tarukado, Kiyoshi; Senba, Hideyuki; Kitamura, Takahiro; Komiya, Norihiro; Shidahara, Satoshi

2014-01-01

245

Intradural schwannoma complicated by lumbar disc herniation at the same level: A case report and review of the literature  

PubMed Central

Intradural tumours of the spine are usually benign and have a good prognosis, if they are diagnosed and removed early. Lumbar disc herniation is a common cause of chronic, acute, or recurrent lumbar radiculopathy. However, to date, there have been no reports of progressive neurological deficiencies due to the co-existence of two significant pathologies contributing to intradural and extradural compression. The current study reports the rare case of a patient with simultaneous extradural and intradural compression of the nerve root due to co-existent intervertebral disc herniation and an intradural schwannoma at the same level. A 71-year-old female suffering from lower back pain and radiating pain of the right lower extremities was admitted to Busan Korea Hospital (Busan, Korea). Magnetic resonance imaging revealed lumbar disc herniation at L4–5 and a mass occupying the intradural space at the same level of the compressed dural sac. Using the posterior approach, surgical excision of the two pathologies was performed. Pathological diagnosis confirmed schwannoma and the symptoms markedly improved. PMID:25013519

BAEK, SEUNG-WOOK; KIM, CHEOL; CHANG, HAN

2014-01-01

246

Cervical myelopathy caused by disc herniation at the segment of existing osteochondroma in a patient with hereditary multiple exostoses.  

PubMed

Hereditary multiple exostoses (HME) is a benign hereditary disorder characterized by multiple osteochondromas. Osteochondroma appears occasionally in the spinal column as a part of HME. A 37-year-old man presented with a history of HME and cervical compressive myelopathy caused by intraspinal osteochondroma arising from the lamina of the C5 and disc herniation at the C5-6. He was treated by open-door laminoplasty at the C5 and C6 with excision of the tumor. The neurological symptoms were immediately relieved after surgery. Magnetic resonance images demonstrated a sufficient decompression of the spinal cord with a spontaneous regression of the herniated disc at one year after surgery. There was no recurrence of the tumor and no appearance of kyphosis and segmental instability of the cervical spine on postoperative imaging studies for three years after surgery. The patient could be successfully treated by laminoplasty with excision of the tumor and without removal of the herniated disc. PMID:25558330

Ikuta, Ko; Tarukado, Kiyoshi; Senba, Hideyuki; Kitamura, Takahiro; Komiya, Norihiro; Shidahara, Satoshi

2014-12-01

247

Feasibility and Efficacy of Percutaneous Lateral Lumbar Discectomy in the Treatment of Patients with Lumbar Disc Herniation: A Preliminary Experience  

PubMed Central

Objective. This study was aimed at evaluating the effectiveness and safety of percutaneous lateral lumbar discectomy (PLLD) in treating patients with lumber disc herniation. Methods. A total of 183 patients with lumbar disc herniation were recruited to receive PLLD surgery from April 2006 to October 2011. All the adverse effects were recorded during the follow-up at 1, 3, 6, and 12 months after PLLD. The clinical outcomes were determined by visual analog scale and Japanese Orthopaedic Association score. Results. The surgery was performed successfully in all patients (102 males and 81 females aged from 21 to 66 years) with a mean 16.6-month follow-up (range from 26 to 65 months). No postoperative complications, including intestinal and vascular complications, nerve injuries, and postoperative infections, were associated with PLLD. At one month after surgery, visual analog scale (3.12±1.44 versus 6.76±2.31, P<0.05) was significantly lower than the baseline and was sustained until 24 months after surgery (3.25 ± 1.78 versus 6.76±2.31, P<0.05). Besides that, Japanese Orthopaedic Association score (25.25±3.21 versus 11.78±2.38, P<0.05) was increased when compared to the baseline. Conclusions. PLLD was a promising, mini-invasive, and effective treatment for lumber disc herniation.

Jiang, Wenjin; Sun, Bolin; Sheng, Qirui; Song, Xuepeng; Zheng, Yanbo; Wang, Ligang

2015-01-01

248

Pure traumatic upper cervical disc herniation causing spinal cord injury: a case report and review of literature  

PubMed Central

Abstract: One third of all spinal injuries involve cervical vertebrae, and the impact of injury to the cervical spinal cord is profound and requires systemic treatment. The role and timing of surgical decompression after an acute spinal cord injury (SCI) remains one of the most controversial topics pertaining to spinal surgery. Lack of controlled, prospective, multicenter clinical studies has contributed to confusion in optimal treatment methods for patients with injuries of the cervical spinal cord. Clinically, the question of whether surgical decompression improves motor recovery following SCI remains surrounded by controversy. Case: Two cases with a 32-year-old man who developed right -sided Brown-Séquard Syndrome Following a motor to car accident with the large right paramedian C3–C4 disc herniation, and ipsilateral spinal cord compression and a 30-year-old man with the syndrome of acute central cervical spinal cord injury with motor impairment involving only upper extremities due to central C2–C3 disc herniation following a pedestrian accident are reported. Discectomy and anterior cervical fusion with the polyetheretherketone (PEEK) cage were performed. A complete motor deficit recovery and a marked sensitive deficit improvement were obtained. The need for and timing of surgical decompression in post traumatic spinal cord injury is controversial. Surgery may expedite neurological recovery in some patients and may provide additional neurological recovery when clinical improvement has plateaued or worsened. In our patient a complete motor deficit recovery was observed. Keywords: Cervical, Disc herniation, Spinal cord injury

Sharifi, Guive; Mosavi, Seyed Ali; Shafieezad, Misagh; Asgari Nosari, Massoud

2012-01-01

249

Checkerboard Model of the Nucleus  

Microsoft Academic Search

The Checkerboard Model (CBM) is a new proposed model of the structure of the nucleus. This model assumes that the nucleons are oriented on a 2 dimensional plane patterned like a checkerboard. This model explains the strong nuclear force as being a combination of flux coupling along with the simultaneous near approach of quarks of opposite charge at the perimeters

Theodore Lach

2002-01-01

250

Transcalvarial brain herniation volume after decompressive craniectomy is the difference between two spherical caps.  

PubMed

Decompressive craniectomy (DC) is a surgical procedure used to relieve severely increased intracranial pressure (ICP) by removing a portion of the skull. Following DC, the brain expands through the skull defect created by DC, resulting in transcalvarial herniation (TCH). Traditionally, people measure only changes in the ICP but not in the intracranial volume (ICV), which is equivalent to the volume of TCH (VTCH), in patients undergoing DC. We constructed a simple model of the cerebral hemispheres, assuming the shape of the upper half of a sphere with a radius of 8cm. We hypothesized that the herniated brain following DC also conforms to the shape of a spherical cap. Considering that a circular piece of the skull with a radius of a was removed, VTCH is the volume difference between 2 spherical caps at the operated side and the corresponding non-operated side, which represents the pre-DC volume underneath the removed skull due to the bilateral symmetry of the skull and the brain. Subsequently, we hypothesized that the maximal extent of TCH depends on a because of the biomechanical limitations imposed by the inelastic scalp. The maximum value of VTCH is 365.0mL when a is 7.05cm and the height difference between the spherical caps (?h) at its maximum is 2.83cm. To facilitate rapid calculation of VTCH, we proposed a simplified estimation formula, VˆTCH=12A(2)?h, where A=2a. With the a value ranging between 0 and 7cm, the ratio between VˆTCH and VTCH ranges between 0.77 and 1.27, with different ?h values. For elliptical skull defects with base diameters of A and C, the formula changes to VˆTCH=12AC?h. If our hypothesis is correct, surgeons can accurately calculate VTCH after DC. Furthermore, this can facilitate volumetric comparisons between the effects of DCs in skulls of varying sizes, allowing quantitative comparisons between ICVs in addition to ICPs. PMID:25583637

Liao, Chun-Chih; Tsai, Yi-Hsin; Chen, Yi-Long; Huang, Ke-Chun; Chiang, I-Jen; Wong, Jau-Min; Xiao, Furen

2015-03-01

251

Operative management of lumbar disc herniation : the evolution of knowledge and surgical techniques in the last century.  

PubMed

Removal of a herniated disc with the use of the operative microscope was first performed by Yasargil (Adv Neurosurg. 4:81-2, 1977) in 1977. However, it began to be used more and more only in the late 1980s (McCulloch JA (1989) Principles of microsurgery for lumbar disc disease. Raven Press, New York). In the 1990s, many spinal surgeons abandoned conventional discectomy with naked-eye to pass to the routine practice of microdiscectomy. The merits of this technique are that it allows every type of disc herniation to be excised through a short approach to skin, fascia and muscles as well as a limited laminoarthrectomy. For these reasons, it has been, and still is, considered the "gold standard" of surgical treatment for lumbar disc herniation, and the method used by the vast majority of spinal surgeons. In the 1990s, the advent of MRI and the progressive increase in definition of this modality of imaging, as well as histopathologic and immunochemical studies of disc tissue and the analysis of the results of conservative treatments have considerably contributed to the knowledge of the natural evolution of a herniated disc. It was shown that disc herniation may decrease in size or disappear in a few weeks or months. Since the second half of the 1990s there has been a revival of percutaneous procedures. Some of these are similar to the percutaneous automated nucleotomy; other methods are represented by intradiscal injection of a mixture of "oxygen-ozone" (Alexandre A, Buric J, Paradiso R. et al. (2001) Intradiscal injection of oxygen ozone for the treatment of lumbar disc herniations: result at 5 years. 12th World Congress of Neurosurgery; 284-7), or laserdiscectomy performed under CT scan (Menchetti PPM. (2006) Laser Med Sci. 4:25-7). The really emerging procedure is that using an endoscope inserted into the disc through the intervertebral foramen to visualize the herniation and remove it manually using thin pituitary rongeurs, a radiofrequency probe or both (Chiu JC. (2004) Surg Technol Int. 13:276-86).Microdiscectomy is still the standard method of treatment due to its simplicity, low rate of complications and high percentage of satisfactory results, which exceed 90% in the largest series. Endoscopic transforaminal discectomy appears to be a reliable method, able to give similar results to microdiscectomy, provided the surgeon is expert enough in the technique, which implies a long learning curve in order to perform the operation effectively, with no complications. All the non-endoscopic percutaneous procedures now available can be used, but the patient must be clearly informed that while the procedure is simple and rapid, at least for the disc L4-L5 and those above (except for laserdiscectomy under CT, that can be easily performed also at L5-S1), their success rate ranges from 60 to 70% and that, in many cases, pain may decrease slowly and may take even several weeks to disappear. PMID:21107933

Postacchini, F; Postacchini, R

2011-01-01

252

Single nucleon emission in relativistic nucleus-nucleus reactions  

NASA Technical Reports Server (NTRS)

Significant discrepancies between theory and experiment have previously been noted for nucleon emission via electromagnetic processes in relativistic nucleus-nucleus collisions. The present work investigates the hypothesis that these discrepancies have arisen due to uncertainties about how to deduce the experimental electromagnetic cross section from the total measured cross section. An optical-model calculation of single neutron removal is added to electromagnetic cross sections and compared to the total experimental cross sections. Good agreement is found thereby resolving some of the earlier noted discrepancies. A detailed comparison to the recent work of Benesh, Cook, and Vary is made for both the impact parameter and the nuclear cross section. Good agreement is obtained giving an independent confirmation of the parameterized formulas developed by those authors.

Norbury, John W.; Townsend, Lawrence W.

1992-01-01

253

Dynamical nucleus-nucleus potential at short distances  

SciTech Connect

The dynamical nucleus-nucleus potentials for fusion reactions {sup 40}Ca+{sup 40}Ca, {sup 48}Ca+{sup 208}Pb, and {sup 126}Sn+{sup 130}Te are studied with the improved quantum molecular dynamics model together with the extended Thomas-Fermi approximation for the kinetic energies of nuclei. The obtained fusion barrier for {sup 40}Ca+{sup 40}Ca is in good agreement with the extracted fusion barrier from the measured fusion excitation function, and the depths of the fusion pockets are close to the results of time-dependent Hartree-Fock calculations. The energy dependence of the fusion barrier is also investigated. The fusion pocket becomes shallow for a heavy fusion system and almost disappears for heavy nearly symmetric systems, and the obtained potential at short distances is higher than the adiabatic potential.

Jiang Yongying; Wang Ning [Department of Physics, Guangxi Normal University, Guilin 541004 (China); Li Zhuxia [China Institute of Atomic Energy, Beijing 102413 (China); Scheid, Werner [Institute for Theoretical Physics, Justus-Liebig-University, D-35392 Giessen (Germany)

2010-04-15

254

Transverse Energy in nucleus-nucleus collisions: A review  

SciTech Connect

The status of Transverse Energy (E/sub T/) in relativistic nucleus-nucleus collisions at the Brookhaven AGS and the CERN SPS is reviewed. The definition of E/sub T/ and its physical significance are discussed. The basic techniques and limitations of the experimental measurements are presented. The acceptances of the major experiments to be discussed are shown, along with remarks about their idiosyncrasies. The data demonstrate that the nuclear geometry of colliding spheres primarily determines the shapes of the observed spectra. Careful account of the acceptances is crucial to comparing and interpreting results. It is concluded that nuclear stopping power is high, and that the amount of energy deposited into the interaction volume is increasing with beam energy even at SPS energies. The energy densities believed to be obtained at the SPS are close to the critical values predicted for the onset of a quark-gluon plasma. 25 refs., 8 figs.

Tincknell, M.

1988-11-15

255

Genetic mapping of a susceptibility locus for disc herniation and spastic paraplegia on 6q23.3-q24.1  

PubMed Central

It has been suggested that a genetic factor(s) or a familial predisposition may contribute to the clinical manifestations of disc herniation; moreover, no genetic linkage between spinal disc herniation and spastic paraplegia has ever been described. A family with consanguineous parents and four of eight sibs affected by multiple disc herniations and spastic paraplegia was clinically and genetically analysed. Surgery caused partial improvement in all of them. After the exclusion of type II collagen and vitamin D receptor genes and the recessive loci for HSPs, a genome wide search was performed with about 500 fluorescent markers. Positive lod score values were obtained for chromosome 6q22.31-q24.1, with evidence of three homozygous intervals. The maximum multipoint lod score of 3.28 was obtained in only one interval, between markers D6S1699 and D6S314. On the whole, a susceptibility locus for disc herniation and autosomal recessive spastic paraplegia was found on chromosome 6q23.3-q24.1. This is the first time that disc herniation and the associated neurological syndrome has been linked to a human chromosomal region. PMID:12070243

Zortea, M; Vettori, A; Trevisan, C; Bellini, S; Vazza, G; Armani, M; Simonati, A; Mostacciuolo, M

2002-01-01

256

Efficacy of Epidural Neuroplasty Versus Transforaminal Epidural Steroid Injection for the Radiating Pain Caused by a Herniated Lumbar Disc  

PubMed Central

Objective To compare the treatment effects of epidural neuroplasty (NP) and transforaminal epidural steroid injection (TFESI) for the radiating pain caused by herniated lumbar disc. Methods Thirty-two patients diagnosed with herniated lumbar disc through magnetic resonance imaging or computed tomography were included in this study. Fourteen patients received an epidural NP and eighteen patients had a TFESI. The visual analogue scale (VAS) and functional rating index (FRI) were measured before the treatment, and at 2 weeks, 4 weeks and 8 weeks after the treatment. Results In the epidural NP group, the mean values of the VAS before the treatment, and at 2 weeks, 4 weeks and 8 weeks after the treatment were 7.00±1.52, 4.29±1.20, 2.64±0.93, 1.43±0.51 and those of FRI were 23.57±3.84, 16.50±3.48, 11.43±2.44, 7.00±2.15. In the TFESI group, the mean values of the VAS before the treatment, and at 2 weeks, 4 weeks and 8 weeks after the treatment were 7.22±2.05, 4.28±1.67, 2.56±1.04, 1.33±0.49 and those of FRI were 22.00±6.64, 16.22±5.07, 11.56±4.18, 8.06±1.89. During the follow-up period, the values of VAS and FRI within each group were significantly reduced (p<0.05) after the treatment. But there were no significant differences between the two groups statistically. Conclusion Epidural NP and TFESI are equally effective treatments for the reduction of radiating pain and for improvement of function in patients with a herniated lumbar disc. We recommend that TFESI should be primarily applied to patients who need interventional spine treatment, because it is easier and more cost-effective than epidural NP. PMID:24466517

Kim, Hae Jong; Rim, Byeong Cheol; Lim, Jeong-Wook; Park, Noh Kyoung; Kang, Tae-Wook; Sohn, Min Kyun; Beom, Jaewon

2013-01-01

257

Fluoroscopic caudal epidural injections in managing chronic axial low back pain without disc herniation, radiculitis, or facet joint pain  

PubMed Central

Background Chronic low back pain without disc herniation is common. Various modalities of treatments are utilized in managing this condition, including epidural injections. However, there is continued debate on the effectiveness, indications, and medical necessity of any treatment modality utilized for managing axial or discogenic pain, including epidural injections. Methods A randomized, double-blind, actively controlled trial was conducted. The objective was to evaluate the ability to assess the effectiveness of caudal epidural injections of local anesthetic with or without steroids for managing chronic low back pain not caused by disc herniation, radiculitis, facet joints, or sacroiliac joints. A total of 120 patients were randomized to two groups; one group did not receive steroids (group 1) and the other group did (group 2). There were 60 patients in each group. The primary outcome measure was at least 50% improvement in Numeric Rating Scale and Oswestry Disability Index. Secondary outcome measures were employment status and opioid intake. These measures were assessed at 3, 6, 12, 18, and 24 months after treatment. Results Significant pain relief and functional status improvement (primary outcome) defined as a 50% or more reduction in scores from baseline, were observed in 54% of patients in group 1 and 60% of patients in group 2 at 24 months. In contrast, 84% of patients in group 1 and 73% in group 2 saw significant pain relief and functional status improvement in the successful groups at 24 months. Conclusion Caudal epidural injections of local anesthetic with or without steroids are effective in patients with chronic axial low back pain of discogenic origin without facet joint pain, disc herniation, and/or radiculitis. PMID:23091395

Manchikanti, Laxmaiah; Cash, Kimberly A; McManus, Carla D; Pampati, Vidyasagar

2012-01-01

258

Instrumented transforaminal lumbar interbody fusion in surgical treatment of recurrent disc herniation  

PubMed Central

Background: The incidence of recurrence in patients undergoing primary discectomy due to lumbar disc herniation (LDH), is regularly reported as 5-15%. In this study we aimed to evaluate surgical outcome of instrumented transforaminal lumbar interbody fusion (TLIF) in the patients suffering from recurrent LDH. Methods: We retrospectively studied 51 patients (30 female, 21 male) from August 2007 to October 2011. The mean age and follow-up of the patients was 46.4±14.8 (ranged; 29-77 years old) and 31.4±6.8 (ranged; 25-50 months), respectively. Clinical improvement was assessed by Oswestry Disability Index (ODI), visual analogue scale (VAS), and subjective satisfaction rate, while fusion was appraised radiologically. Data analysis was by one sample Kolmogorov-Smirnov, paired t, and Mann-Whitney tests. Results: Surgery could significantly improve mean leg and lumbar VAS and ODI from preoperative 7.4±2.5, 7.8±3.1, and 72.1±21.5 to postoperative 3.4±3.6, 3.5±2.6, and 27.5±18.0, respectively at the last follow-up visit. Subjective satisfaction rate was excellent in 24 patients (47.1%), good in 14 (27.5%), fair 11 (21.6%), and poor in two (3.9%). We had one patient with iatrogenic partial L5 nerve root injury and one with unknown late onset refractory postoperative back pain. Fusion rate was 100% and instrument failure was nil. Conclusion: In surgical treatment of the patients with recurrent LDH, bilaterally instrumented TLIF is a relatively safe and effective procedure and can be associated with least instrument failure and highest fusion rate while no postoperative bracing is also needed.

Omidi-Kashani, Farzad; Ghayem Hasankhani, Ebrahim; Noroozi, Hamid Reza

2014-01-01

259

A PHASED REHABILITATION PROTOCOL FOR ATHLETES WITH LUMBAR INTERVERTEBRAL DISC HERNIATION  

PubMed Central

Conservative non-surgical management of a herniated lumbar intervertebral disc (HLD) in athletes is a complex task due to the dramatic forces imparted on the spine during sport participation. The demands placed upon the athlete during rehabilitation and return to sport are unique not only from a sport specific perspective, but also regarding return to the sport strength and conditioning programs utilized for sport preparation. Many prescriptions fail to address postural and motor control faults specific to athletic development, which may prevent full return to sport after suffering a HLD or predispose the athlete to future exacerbations of a HLD. Strength exercises involving squatting, deadlifting, and Olympic power lifts are large components of the typical athlete's conditioning program, therefore some progressions are provided to address potential underlying problems in the athlete's technique that may have contributed to their HLD in the first place. The purpose of this clinical commentary is to propose a framework for rehabilitation that is built around the phases of healing of the disc. Phase I: Non-Rotational/Non-Flexion Phase (Acute Inflammatory Phase), Phase II: Counter rotation/Flexion Phase (Repair Phase), Phase III: Rotational Phase/Power development (Remodeling Phase), and Phase IV: Full return to sport. This clinical commentary provides a theoretical basis for these phases based on available literature as well as reviewing many popular current practice trends in the management of an HLD. The authors recognize the limits of any general exercise rehabilitation recommendation with regard to return to sport, as well as any general strength and conditioning program. It is vital that an individual assessment and prescription is made for every athlete which reviews and addresses movement in all planes of motion under all necessary extrinsic and intrinsic demands to that athlete. Level of Evidence: 5 PMID:24175134

VanGelder, Leonard H.; Vaughn, Daniel W.

2013-01-01

260

Transforaminal Epidural Clonidine versus Corticosteroid for Acute Lumbosacral Radiculopathy due to Intervertebral Disk Herniation  

PubMed Central

Study Design Randomized, double-blinded trial clinical trial. Objective To compare efficacies of 2 active therapies for chronic low back pain. Summary of Background Data Radicular pain may result from intervertebral disk herniation (IDH). Clonidine has demonstrated analgesic and antiinflammatory activity in animal studies of nerve injury. Extensive clinical experience supports neuraxial clonidine's safety. Methods Patients with ˜3 months of low back and leg pain due to IDH were randomized to transforaminal epidural (TFE) injection(s) of 2% lidocaine and either clonidine (200 or 400mcg) or triamcinolone (40mg). Patients received 1- 3 injections administered about 2 weeks apart. Patients, investigators and study coordinators were blinded to treatment. Primary outcome was 11-point Pain Intensity Numerical Rating Scale (PI-NRS) at 1 month. Other outcomes included Patient Global Impression of Change (PGIC), and functional measures. Results Thirty-three patients were screened and randomized. Twenty-six patients enrolled; 11 received clonidine and 15 triamcinolone. Both groups showed significant improvement in pain score at 2 weeks and 1 month compared to baseline (p< 0.05). The corticosteroid group showed additional functional improvement at 1 month relative to clonidine (p=0.022). There was no difference between groups for primary outcome. However, as target enrollment was not reached, we cannot say with confidence that the 2 treatments would be expected to result in similar short-term pain relief. Side-effects were common in both groups, but there were no serious complications. Conclusions Radicular pain due to IDH improved rapidly with TFE injection of either clonidine or triamcinolone. Corticosteroid resulted in greater functional improvement, with unclear differences in analgesia. Future studies will determine if clonidine is superior to placebo and of particular use in those at risk for corticosteroid complications. PMID:21192304

Burgher, Abram H.; Hoelzer, Bryan C.; Schroeder, Darrell R.; Wilson, Gregory A.; Huntoon, Marc A.

2010-01-01

261

Do preoperative fear avoidance model factors predict outcomes after lumbar disc herniation surgery? A systematic review  

PubMed Central

Background Lumbar disc herniation (LDH) surgery is usually recommended when conservative treatments fail to manage patients’ symptoms. However, many patients undergoing LDH surgery continue to report pain and disability. Preoperative psychological factors have shown to be predictive for postoperative outcomes. Our aim was to systematically review studies that prospectively examined the prognostic value of factors in the Fear Avoidance Model (FAM), including back pain, leg pain, catastrophizing, anxiety, fear-avoidance, depression, physical activity and disability, to predict postoperative outcomes in patients undergoing LDH surgery. Methods We performed a systematic literature review of prospective studies that measured any FAM factors preoperatively to predict postoperative outcomes for patients undergoing LDH surgery. Our search databases included PubMed, CINAHL, and PsycINFO. We assessed the quality of each included study using a certain quality assessment list. Degree of agreement between reviewers on quality assessment was examined. Results related to FAM factors in the included studies were summarized. Results Thirteen prospective studies met our inclusion criteria. Most studies were considered high quality. Heterogeneity was present between the included studies in many aspects. The most common FAM factors examinered were baseline pain, disability and depression. In, general, depression, fear-avoidance behaviors, passive pain coping, and anxiety FAM factors appeared to have negative influence on LDH surgical outcome. Baseline back pain and leg pain appeared to have differing prognostic value on LDH surgical outcomes. Conclusions FAM factors seem to influence LDH surgical outcomes. Patients with high levels of depression, anxiety and fear-avoidance behaviors are more likely to have poor outcomes following LDH surgery. Conversely, high levels of leg pain, but not back pain seem to be predictor for favorable LDH surgery outcome. More research is needed to determine the exact role of FAM factors on LDH surgical outcome and the value for screening for these factors. PMID:24237581

2013-01-01

262

Herniation Pits in Human Mummies: A CT Investigation in the Capuchin Catacombs of Palermo, Sicily  

PubMed Central

Herniation pits (HPs) of the femoral neck were first described in a radiological publication in 1982 as round to oval radiolucencies in the proximal superior quadrant of the femoral neck on anteroposterior radiographs of adults. In following early clinical publications, HPs were generally recognized as an incidental finding. In contrast, in current clinical literature they are mentioned in the context of femoroacetabular impingement (FAI) of the hip joint, which is known to cause osteoarthritis (OA). The significance of HPs in chronic skeletal disorders such as OA is still unclear, but they are discussed as a possible radiological indicator for FAI in a large part of clinical studies. In this paleoradiological study we examined a sample of mummies from the Capuchin Catacombs of Palermo, Sicily, by a mobile computed tomography (CT) scanner. Evaluation of the CT examinations revealed HPs in six out of 16 (37.5%) adult male mummies. The first aim of this study was to compare the characteristics of HPs shown in our mummy collection to the findings described in clinical literature. Thereby CT evaluation revealed that their osseous imaging characteristics are in accordance, consisting of round to oval subcortical lesions at the anterior femoral neck, clearly demarcated by a sclerotic margin. The second aim was to introduce HPs to the paleoradiological and paleopathological methodology as an entity that underwent a renaissance from an incidental finding to a possible radiological indicator of FAI in the clinical situation. As FAI plays an important role in the development of OA of the hip, which is a very common finding in human skeletal remains, HPs should always be considered in paleoradiological evaluation of hip joint diseases. PMID:22567164

Panzer, Stephanie; Piombino-Mascali, Dario; Zink, Albert R.

2012-01-01

263

Cytoarchitectonics of the human nucleus accumbens.  

PubMed

More than 400 publications per year deal with the Nucleus accumbens, however its morphological substrate and anatomical borders appear arbitrary. With a modified Nissi-technique applied to complete sets of thick serial, frontoparallel sections, it became possible to characterize the human Nucleus accumbens. In two series a clear delineation of its borders is documented. Along its rostro-caudal axis, the Nucleus accumbens shows morphological differences: the rostral Nucleus accumbens exhibits a higher cell-density and basophilia than Nucleus caudatus and Putamen; in caudal planes, the Nucleus accumbens dissolves into cell-clusters. A hitherto unrecognized supracommissural part of the Nucleus accumbens dorsal to the Commissura anterior is contiguous to the medial and lateral parts of the Nucleus interstitialis striae terminalis. The thickness of the hemispheric slices (approximately 600 micrometers) facilitated the topographical unravelling of the surrounding cell-islands. In accordance with Sanides (1957) these islands were referred to as Insulae terminales. Based on their topography and cellular structure, they were termed insulae terminales subputaminales (ltsp), Insulae terminales nuclei accumbentis (Itna), Insulae terminales supracommissurales (Itsc) and Insulae terminales olfactoriae mediales et laterales (Itom, Itol). The Insulae terminales form an almost complete envelope around the human Nucleus accumbens and could correspond to the neurochemically defined accumbal shell-region of the rat. Marked differences between medial and lateral insulae terminales olfactoriae permit a clear delineation between the human Nucleus accumbens and the lateral, rudimentary Tuberculum olfactorium: the basis for modifying the concept of a ventral striatum in man. PMID:8776506

Lauer, M; Heinsen, H

1996-01-01

264

a Unified Approach to Hadron-Hadron Hadron-Nucleus and Nucleus-Nucleus Collisions at High Energy  

Microsoft Academic Search

The problem of multiparticle production in high -energy hadron-hadron, hadron-nucleus and nucleus-nucleus collisions are studied systematically in the framework of the Geometrical Branching Model (GBM). The model is based on the geometrical properties of nucleons and the stochastic nature of the interaction among the soft partons. The eikonal formalism is used to relate the elastic and inelastic cross sections and

Xin-Nian Wang; Xinnian

1989-01-01

265

Retrotrapezoid nucleus in the rat.  

PubMed

The retrotrapezoid nucleus (RTN), recently described in the cat, is an anatomically identified cell group of the ventral medulla. It is of interest because of its possible role in the generation or control of breathing. The present investigation confirms the existence in the rat of an analogous cell group, as identified by retrograde transport of rhodamine microbeads from an injection site in the ventral respiratory group of the ventral medulla. Electrophysiological recordings from the region of RTN reveal individual units with respiratory related activity. These results support a possible role for the RTN in the control of breathing. PMID:2771161

Pearce, R A; Stornetta, R L; Guyenet, P G

1989-06-19

266

Nucleus morphology of Comet Halley  

NASA Technical Reports Server (NTRS)

Images obtained by the Halley multicolor camera were used to determine the projected size and shape of the nucleus. The location of the terminator and numerous surface features were determined. There is good correlation between the brightest surface features and the dust jets; however, many bright features are seen which are not associated with jets. Most of the observed features are circular and appear to be related to surface elevation. The angularity of the terminator gives an indication of the three-dimensional structure of the face which was observed.

Reitsema, H. J.; Delamere, W. A.; Huebner, W. F.; Keller, H. U.; Schmidt, W. K. H.; Wilhelm, K.; Schmidt, H. U.; Whipple, Fred L.

1986-01-01

267

Retrotrapezoid nucleus and central chemoreception.  

PubMed

The 'distributed chemoreception theory' attributes the central chemoreflex (the stimulation of breathing by CNS acidification) to the cumulative effects of pH on multiple classes of respiratory neurons as well as on their tonic sources of drive. Opinions differ as to how many classes of pH-sensitive neurons contribute to the central chemoreflex but the number of candidates is high and growing fast. The 'specialized chemoreceptor theory', endorsed here, attributes the chemoreflex to a limited number of specialized neurons. These neurons (the central chemoreceptors) would drive a respiratory pattern generator that is not or minimally activated by acidification. In this review we first describe the properties of the retrotrapezoid nucleus (RTN) and argue that this nucleus may contain the most important central chemoreceptors. Next, we subject the assumptions that underlie the distributed chemoreception theory to a critical analysis. We propose several explanations for the apparent contradiction between the two competing theories of central chemoreception. We attribute much of the current controversy to premature extrapolations of the effects of acidification on neurons recorded in vitro (chemosensitivity) and to a semantic confusion between chemosensitivity and chemoreception (the mechanism by which CO(2) or pH activates breathing in vivo). PMID:18308822

Guyenet, Patrice G; Stornetta, Ruth L; Bayliss, Douglas A

2008-04-15

268

Comet nucleus sample return mission  

NASA Technical Reports Server (NTRS)

A comet nucleus sample return mission in terms of its relevant science objectives, candidate mission concepts, key design/technology requirements, and programmatic issues is discussed. The primary objective was to collect a sample of undisturbed comet material from beneath the surface of an active comet and to preserve its chemical and, if possible, its physical integrity and return it to Earth in a minimally altered state. The secondary objectives are to: (1) characterize the comet to a level consistent with a rendezvous mission; (2) monitor the comet dynamics through perihelion and aphelion with a long lived lander; and (3) determine the subsurface properties of the nucleus in an area local to the sampled core. A set of candidate comets is discussed. The hazards which the spacecraft would encounter in the vicinity of the comet are also discussed. The encounter strategy, the sampling hardware, the thermal control of the pristine comet material during the return to Earth, and the flight performance of various spacecraft systems and the cost estimates of such a mission are presented.

1983-01-01

269

[Postpartum secondary cerebral venous sinus thrombosis with axial transtentorial and tonsillar herniation as a complication of intracranial hypotension syndrome after spinal anaesthesia].  

PubMed

We describe the case of a 28-year-old postpartum female patient who suffered from a secondary cerebral venous sinus thrombosis due to an intracranial hypotension syndrome with axial transtentorial and tonsillar herniation and the clinical signs of incarceration after spinal anaesthesia. PMID:25489758

Kraayvanger, L; Berlit, P

2014-12-01

270

Alcohol Effects on Paraventricular Hypothalamic Nucleus Morphometry  

Microsoft Academic Search

The morphometric effects of postnatal exposure to alcohol on the neurons of the paraventricular hypothalamic nucleus (PVN) have been studied in four different topographic subdivisions of the nucleus: rostral, intermediate medial, intermediate lateral and caudal. Male mice were exposed to alcohol during lactation and after weaning by addition of 20% of ethanol to the drinking water that was first ingested

M. Pérez-Delgado; M. G. Garcia-Garcia; E. Carmona-Calero; H. Pérez-González; A. Castañeyra-Perdomo; R. Ferres-Torres

1995-01-01

271

The nature of the cometary nucleus  

NASA Technical Reports Server (NTRS)

The basic properties of the cometary nucleus are reviewed. Consideration is given to the absence of depth differentiation, the icy conglomerate nature, the possible existence of a halo of icy grains around the nuclear region, the nucleus size and albedo, the mass, the rotation rate, and the chemical composition (elemental and molecular).

Delsemme, A. H.

1985-01-01

272

Acute spontaneous cervical disc herniation causing rapidly progressive myelopathy in a patient with comorbid ossified posterior longitudinal ligament: Case report and literature review  

PubMed Central

Background: Ossification of the posterior longitudinal ligament (OPLL) and cervical disc herniation are commonly encountered neurosurgical conditions. Here we present an unusual case of nontraumatic rapidly progressive myelopathy due to cervical disc herniation with comorbid OPLL and conduct a literature review focusing on the frequency and management of disc herniations with OPLL. Case Description: A 52-year-old healthy female presented with a 72-h history of rapid progression of dense quadriparesis with sensory deficits, with a precedent 4-week history of nontraumatic midline neck pain. Clinical examination revealed profound motor deficits below the C5 myotome. Spinal neuroimaging revealed OPLL (computed tomography [CT]) and a cervical disc herniation spanning from C4/5 to C5/6 with significant retrovertebral disease (magnetic resonance imaging [MRI]). Operative management involved an anterior cervical corpectomy and instrumented fusion, with removal of both the sequestered disc material and the locally compressive OPLL. The patient recovered full motor function and independent ambulation with no residual signs or symptoms of myelopathy at the time of discharge. Conclusion: This unique case of a spontaneous cervical disc herniation in the context of OPLL causing rapidly progressive myelopathy illustrates the complementarity of CT and MRI in diagnosing the underlying cause of a rapidly progressive neurologic deficit in the absence of antecedent trauma. Though the optimal surgical management of such pathology remains uncertain; in this case, the anterior approach was motivated by the significant retrovertebral ventrally compressive sequestrum, and provided for excellent neurologic outcome. This article also reviews the occurrence/management of such acute cervical discs with OPLL. PMID:25289163

Westwick, Harrison J.; Goldstein, Christina L.; Shamji, Mohammed F.

2014-01-01

273

Actomyosin contractility rotates the cell nucleus.  

PubMed

The cell nucleus functions amidst active cytoskeletal filaments, but its response to their contractile stresses is largely unexplored. We study the dynamics of the nuclei of single fibroblasts, with cell migration suppressed by plating onto micro-fabricated patterns. We find the nucleus undergoes noisy but coherent rotational motion. We account for this observation through a hydrodynamic approach, treating the nucleus as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active stresses. Lowering actin contractility selectively by introducing blebbistatin at low concentrations drastically reduced the speed and coherence of the angular motion of the nucleus. Time-lapse imaging of actin revealed a correlated hydrodynamic flow around the nucleus, with profile and magnitude consistent with the results of our theoretical approach. Coherent intracellular flows and consequent nuclear rotation thus appear to be an intrinsic property of cells. PMID:24445418

Kumar, Abhishek; Maitra, Ananyo; Sumit, Madhuresh; Ramaswamy, Sriram; Shivashankar, G V

2014-01-01

274

Actomyosin contractility rotates the cell nucleus  

PubMed Central

The cell nucleus functions amidst active cytoskeletal filaments, but its response to their contractile stresses is largely unexplored. We study the dynamics of the nuclei of single fibroblasts, with cell migration suppressed by plating onto micro-fabricated patterns. We find the nucleus undergoes noisy but coherent rotational motion. We account for this observation through a hydrodynamic approach, treating the nucleus as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active stresses. Lowering actin contractility selectively by introducing blebbistatin at low concentrations drastically reduced the speed and coherence of the angular motion of the nucleus. Time-lapse imaging of actin revealed a correlated hydrodynamic flow around the nucleus, with profile and magnitude consistent with the results of our theoretical approach. Coherent intracellular flows and consequent nuclear rotation thus appear to be an intrinsic property of cells. PMID:24445418

Kumar, Abhishek; Maitra, Ananyo; Sumit, Madhuresh; Ramaswamy, Sriram; Shivashankar, G. V.

2014-01-01

275

Long-Term Outcomes of Patients with Lumbar Disc Herniation Treated with Percutaneous Discectomy: Comparative Study with Microendoscopic Discectomy  

SciTech Connect

We assessed the long-term outcomes of patients with lumbar disc herniation treated with percutaneous lumbar discectomy (PLD) or microendoscopic discectomy (MED). A retrospective study was performed in consecutive patients with lumbar disc herniation treated with PLD (n = 129) or MED (n = 101) in a single hospital from January 2000 to March 2002. All patients were followed up with MacNab criteria and self-evaluation questionnaires comprising the Oswestry Disability Index and Medical Outcomes Study 36-Item Short-Form Health Survey. Several statistical methods were used for analyses of the data, and a p value of <0.05 was considered to be statistically significant. A total of 104 patients (80.62%) with PLD and 82 patients (81.19%) with MED were eligible for analyses, with a mean follow-up period of 6.64 {+-} 0.67 years and 6.42 {+-} 0.51 years, respectively. There were no significant differences between the two groups in age, number of lesions, major symptoms and physical signs, and radiological findings. According to the MacNab criteria, 75.96% in the PLD group and 84.15% in the MED group achieved excellent or good results, respectively, this was statistically significant (p = 0.0402). With the Oswestry Disability Index questionnaires, the average scores and minimal disability, respectively, were 6.97 and 71.15% in the PLD group and 4.89 and 79.27% in the MED group. Total average scores of Medical Outcomes Study 36-Item Short-Form Health Survey were 75.88 vs. 81.86 in PLD group vs. MED group (p = 0.0582). The cost and length of hospitalization were higher or longer in MED group, a statistically significant difference (both p < 0.0001). Long-term complications were observed in two patients (2.44%) in the MED group, no such complications were observed in the PLD group. Both PLD and MED show an acceptable long-term efficacy for treatment of lumbar disc herniation. Compared with MED patients, long-term satisfaction is slightly lower in the PLD patients; complications, hospitalization duration, and costs in PLD group are also lower.

Liu Wengui [Southeast University, Department of Radiology, Zhong-Da Hospital (China); Wu Xiaotao [Southeast University, Department of Orthopedics, Zhong-Da Hospital (China); Guo Jinhe [Southeast University, Department of Radiology, Zhong-Da Hospital (China); Zhuang Suyang [Southeast University, Department of Orthopedics, Zhong-Da Hospital (China); Teng Gaojun, E-mail: gjteng@vip.sina.co [Southeast University, Department of Radiology, Zhong-Da Hospital (China)

2010-08-15

276

The retrotrapezoid nucleus and breathing.  

PubMed

The retrotrapezoid nucleus (RTN) is located in the rostral medulla oblongata close to the ventral surface and consists of a bilateral cluster of glutamatergic neurons that are non-aminergic and express homeodomain transcription factor Phox2b throughout life. These neurons respond vigorously to increases in local pCO(2) via cell-autonomous and paracrine (glial) mechanisms and receive additional chemosensory information from the carotid bodies. RTN neurons exclusively innervate the regions of the brainstem that contain the respiratory pattern generator (RPG). Lesion or inhibition of RTN neurons largely attenuates the respiratory chemoreflex of adult rats whereas their activation increases respiratory rate, inspiratory amplitude and active expiration. Phox2b mutations that cause congenital central hypoventilation syndrome in humans prevent the development of RTN neurons in mice. Selective deletion of the RTN Phox2b-VGLUT2 neurons by genetic means in mice eliminates the respiratory chemoreflex in neonates.In short, RTN Phox2b-VGLUT2 neurons are a major nodal point of the CNS network that regulates pCO(2) via breathing and these cells are probable central chemoreceptors. PMID:23080151

Guyenet, Patrice G; Stornetta, Ruth L; Abbott, Stephen B G; Depuy, Seth D; Kanbar, Roy

2012-01-01

277

Laparoscopic management of a small bowel herniation from an ileal conduit: report of a case and review of the literature.  

PubMed

Bladder carcinoma can be treated with cystectomy and urinary diversion. Ileal conduit is a popular technique, originally performed with closure of all mesenteric and peritoneal defects to minimize internal herniation. Recent advances in laparoscopic and robotic techniques often leave these defects open. We present a case of a 75-year-old gentleman with a small bowel entrapment underneath an intraperitoneal ileal conduit and ureter causing obstruction. This internal hernia occurred 2 months after undergoing a DaVinci robotic-assisted laparoscopic cystoprostatectomy with an ileal conduit. Bowel obstruction is an important complication associated with the need for reoperation and patient mortality. Historical review shows a precedent for closure of the mesenteric defect, obliterating the peritoneal defect in the right lumbar gutter, and suturing the ileal conduit to the posterior peritoneum to prevent potential internal hernias. The literature involving ileal conduits is examined for consensus on the preferred method of treating these potential spaces. PMID:23579536

Coughlin, Lisa M; Orr, Dennis P

2013-04-01

278

Minimally invasive surgery for synchronous, same-level lumbar intradural-extramedullary neoplasm and acute disc herniation.  

PubMed

Schwannomas are the most common intradural-extramedullary spinal tumors, with an estimated incidence of 3 to 10 cases per 100,000 people. With continued advances in minimally invasive surgery (MIS) over recent years, MIS techniques have been utilized by spine surgeons in the resection of intradural spinal neoplasms with favorable surgical results and clinical outcomes. This video demonstrates a rare case of symptomatic, synchronous, same-level lumbar intradural-extramedullary neoplasm and acute disc herniation, both of which were successfully treated using a single MIS approach. Surgical pearls and nuances are discussed to better delineate technique and minimize potential complications. The video can be found here: http://youtu.be/78ibbicBRUk. PMID:25175577

Tan, Lee A; Kasliwal, Manish K; Wewel, Joshua; Fontes, Ricardo B V; O'Toole, John E

2014-09-01

279

The tertiary gustatory center in sunfishes is not nucleus glomerulosus.  

PubMed

Injection of horseradish peroxidase into the secondary gustatory nucleus of the green sunfish, Lepomis cyanellus, resulted in retrogradely filled neurons bilaterally in the viscerosensory column of the brainstem and in anterograde transport revealing ipsilateral terminal fields in the preglomerular tertiary gustatory nucleus, the nucleus of the torus lateralis and the central and periventricular nucleus of the inferior lobe. Thus, the glomerular nucleus of percomorph teleosts is not a tertiary gustatory center. It is proposed that the term 'nucleus glomerulosus' be reserved for the nucleus involved with vision and that the preglomerular subdivision involved in gustation be termed 'nucleus gustatorius tertius'. PMID:3362429

Wullimann, M F

1988-03-21

280

Does disk space degeneration according to Los Angeles and Modic scales have relation with recurrent disk herniation?  

PubMed Central

Background: After single disk herniation operation, about 5–20% recurrences may occur. Different etiology may affect the prevalence of recurrence. Disk degeneration according to Modic and Los Angles scales could affect recurrence rate. This study wants to show the relationship between disk space degeneration according to these scales on severity, time, and prevalence of disk herniation recurrence. Materials and Methods: Thirty-four patients presented with radicular pain (with or without back pain) and history of lumbar disk surgery was included in this prospective study. Pre- and postoperative T2-weighted sagittal magnetic resonance imaging (MRI) compared for Modic and Los Angeles disk degeneration grading, then, data analysis on SPSS (version 20) software, paired t-test, and others. Results: The result of study shows for first operation that grade (II) Los Angeles is the most common, but, for second procedure grade (IV) was less common and the mostly decreased (from 14.7 to 9.2%). In addition, Wilcoxon test shows no change of Los Angeles grading for both first and second surgery (P = 0.06). Whereas; based on Modic criteria grading was different from first operation, in other words, grade (I) (41.2%) in first operation was changed to 20.6% in second operation (P = 0.007). Conclusion: Our study showed that the Los Angeles criterion is more practical and useful for prediction of recurrence and in the patients with Los Angles grade III and IV and grade II and III on Modic scale, the chance of recurrence is less than patients with lower grades.

Abrishamkar, Saied; Mahmoudkhani, Mehdi; Aminmansour, Bahram; Mahabadi, Amir; Jafari, Shohreh

2014-01-01

281

The Surgical Treatment of Single Level Multi-Focal Subarticular and Paracentral and/or Far-Lateral Lumbar Disc Herniations: The Single Incision Full Endoscopic Approach  

PubMed Central

Background Surgery for same level multi-focal extruded lumbar disc herniations is technically challenging and the optimal method controversial. The subarticular disc herniation may pose the most challenging subtype requiring partial or complete facetectomy with or without fusion. The far-lateral disc herniation, often treated using a Wiltse approach, can also be difficult to access especially in the obese patient. When both the subarticular and far-lateral subtypes are simultaneously present at the same level with or without a paracentral disc herniation, a total facetectomy and interbody fusion (TLIF) or a total disc replacement (TDR) may be necessary. Endoscopic surgical techniques may reduce the need for these more invasive methods. Methods Fifteen patients (6 male and 9 female) who had same level multi-focal (subarticular as well as far-lateral and/or paracentral) extruded disc herniations underwent single incision unilateral endoscopic disc excision by the same surgeon at a single institution. Patients were prospectively followed for an average of 15.3 months (range 14-18 months) and outcomes were evaluated radiographically and clinically (Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI). Results The mean operative time was 52 minutes with minimal blood loss in all cases. Fourteen of the 15 patients were discharged to home on the day of their surgery. The mean ODI and leg VAS scores improved from 22.9 ± 3.2 to 12.9 ± 2.7 (p < 0.005), and from 8.6 ± 1.6 to 2.1 + 0.4 (p < 0.005), respectively. Conclusions After an average of 15.3 months of follow-up, the clinical and radiographic results of full endoscopic surgical treatment of single level multi-focal (subarticular as well as far-lateral and/or paracentral) disc herniations are excellent. This study is a case series with mid-term follow-up (Level IV). Clinical Relevance Foraminal and extra-foraminal full endoscopic decompression appears to offer a safe minimally invasive solution to a complex pathologic problem. PMID:25694941

Scott, David L.; Han, Xiao; Yacob, Alem

2014-01-01

282

Responses from electric stimulation of cochlear nucleus  

E-print Network

Cochlear nucleus (CN), the exclusive destination of the auditory nerve, is the gateway for all central processing of auditory information. The CN comprises three major subdivisions: anteroventral, posteroventral and dorsal ...

Suzuki, Ryuji, Ph. D. Massachusetts Institute of Technology

2010-01-01

283

Transport calculations of antiproton-nucleus interactions  

E-print Network

The Giessen Boltzmann-Uehling-Uhlenbeck transport model is extended and applied to the antiproton-nucleus interactions in a wide beam momentum range. The model calculations are compared with the experimental data on $\\bar p$-absorption cross sections on nuclei with an emphasis on extraction of the real part of an antiproton optical potential. The possibility of the cold compression of a nucleus by an antiproton in-flight is also considered.

A. B. Larionov; I. N. Mishustin; I. A. Pshenichnov; L. M. Satarov; W. Greiner

2010-01-15

284

Functional architecture in the cell nucleus.  

PubMed Central

The major functions of the cell nucleus, including transcription, pre-mRNA splicing and ribosome assembly, have been studied extensively by biochemical, genetic and molecular methods. An overwhelming amount of information about their molecular mechanisms is available. In stark contrast, very little is known about how these processes are integrated into the structural framework of the cell nucleus and how they are spatially and temporally co-ordinated within the three-dimensional confines of the nucleus. It is also largely unknown how nuclear architecture affects gene expression. In order to understand how genomes are organized, and how they function, the basic principles that govern nuclear architecture and function must be uncovered. Recent work combining molecular, biochemical and cell biological methods is beginning to shed light on how the nucleus functions and how genes are expressed in vivo. It has become clear that the nucleus contains distinct compartments and that many nuclear components are highly dynamic. Here we describe the major structural compartments of the cell nucleus and discuss their established and proposed functions. We summarize recent observations regarding the dynamic properties of chromatin, mRNA and nuclear proteins, and we consider the implications these findings have for the organization of nuclear processes and gene expression. Finally, we speculate that self-organization might play a substantial role in establishing and maintaining nuclear organization. PMID:11368755

Dundr, M; Misteli, T

2001-01-01

285

The tertiary gustatory center in sunfishes is not nucleus glomerulosus  

Microsoft Academic Search

Injection of horseradish peroxidase into the secondary gustatory nucleus of the green sunfish, Lepomis ~Tanellus, resulted in retrogradely filled neurons bilaterally in the viscerosensory column of the brainstem and in anterograde transport revealing ipsilateral terminal fields in the preglomerular tertiary gustatory nucleus, the nucleus of the torus lateralis and the central and periventricular nucleus of the inferior lobe. Thus, the

Mario F. Wullimann

1988-01-01

286

[Acute abdomen in children: a continuous challenge. Two cases report: Meckel's diverticulum with small bowel volvolus and internal herniation related to epiploic appendagitis mimicking acute appendicitis].  

PubMed

Acute abdomen is a continuous clinical challenge in pediatric age. The aim of our study is to describe two pediatric rare cases: the first case is a small bowel volvolus related to Meckel's diverticulum confused with an intestinal intussusception; the second an internal herniation related to epiploic appendagitis with intestinal obstruction mimic acute appendicitis in two years old children. We review the current literature. PMID:25004643

Gasparella, M; Ferro, M; Marzaro, M; Benetton, C; Zanatta, C; Zoppellaro, F; Gasparella, M

2014-01-01

287

Comparison of the Efficacy of Caudal, Interlaminar, and Transforaminal Epidural Injections in Managing Lumbar Disc Herniation: Is One Method Superior to the Other?  

PubMed Central

Background Epidural injections are performed utilizing 3 approaches in the lumbar spine: caudal, interlaminar, and transforaminal. The literature on the efficacy of epidural injections has been sporadic. There are few high-quality randomized trials performed under fluoroscopy in managing disc herniation that have a long-term follow-up and appropriate outcome parameters. There is also a lack of literature comparing the efficacy of these 3 approaches. Methods This manuscript analyzes data from 3 randomized controlled trials that assessed a total of 360 patients with lumbar disc herniation. There were 120 patients per trial either receiving local anesthetic alone (60 patients) or local anesthetic with steroids (60 patients). Results Analysis showed similar efficacy for caudal, interlaminar, and transforaminal approaches in managing chronic pain and disability from disc herniation. The analysis of caudal epidural injections showed the potential superiority of steroids compared with local anesthetic alone a 2-year follow-up, based on the average relief per procedure. In the interlaminar group, results were somewhat superior for pain relief in the steroid group at 6 months and functional status at 12 months. Interlaminar epidurals provided improvement in a significantly higher proportion of patients. The proportion of patients nonresponsive to initial injections was also lower in the group for local anesthetic with steroid in the interlaminar trial. Conclusions The results of this assessment show significant improvement in patients suffering from chronic lumbar disc herniation with 3 lumbar epidural approaches with local anesthetic alone, or using steroids with long-term follow-up of up to 2 years, in a contemporary interventional pain management setting. PMID:25589942

Singh, Vijay; Pampati, Vidyasagar; Falco, Frank JE; Hirsch, Joshua A.

2015-01-01

288

"Spontaneous" CSF Fistula due to Transtegmental Brain Herniation in Combination with Signs of Increased Intracranial Pressure and Petrous Bone Hyperpneumatization: An Illustrative Case Report.  

PubMed

Background and Importance?Transtegmental brain herniation into the petrous bone is a rare cause of rhinoliquorrhea. Our case presents a combination of several typical clinical and imaging findings illustrating the ongoing etiologic discussion of such cerebrospinal fluid (CSF) fistulas. Clinical Presentation?A 53-year-old man presented with nasal discharge after a strong effort to suppress coughing. Imaging revealed a transtegmental herniation of parts of the inferior temporal gyrus into the petrous bone and in addition a combination of signs of chronically increased intracranial pressure and a hyperpneumatization of the petrous bone. The fistula was closed by a middle cranial fossa approach. Conclusion?The case illustrates the two main predisposing factors for development of petrous bone CSF fistulas: increased intracranial pressure and thinning of the tegmental roof due to extensive development of air cells. Because the CSF leakage repair does not change the underlying cause, patients have to be informed about the possibility of developing increased intracranial pressure and recurrences of brain herniations at other sites. PMID:25485224

Rivera, Diones; Fermin-Delgado, Rafael; Stoeter, Peter

2014-12-01

289

Temperature measurement of quark-gluon plasma formed in high energy nucleus-nucleus collisions  

Microsoft Academic Search

We discuss lepton pair and real photon emission from quark-gluon plasma, which is very likely to be formed in high energy nucleus-nucleus collisions. Measurement of pair production crosssection will provide one with accurate information of the temperature of this plasma.

K. Kajantie; H. I. Miettinen

1981-01-01

290

Polarization of Lambda^0 hyperons in nucleus-nucleus collisions at high energies  

E-print Network

The measurement of Lambda^0 hyperons polarization in nucleus-nucleus collisions is considered as one of possible tools to study the phase transition. Fixed target and collider experiments are discussed for the case of Lambda^0's production from Au-Au central collisions at \\sqrt{s_{NN}} of several GeV.

V. P. Ladygin; A. P. Jerusalimov; N. B. Ladygina

2008-06-24

291

Interpretive monitoring in the caudate nucleus  

PubMed Central

In a dynamic environment an organism has to constantly adjust ongoing behavior to adapt to a given context. This process requires continuous monitoring of ongoing behavior to provide its meaningful interpretation. The caudate nucleus is known to have a role in behavioral monitoring, but the nature of these signals during dynamic behavior is still unclear. We recorded neuronal activity in the caudate nucleus in monkeys during categorization behavior that changed rapidly across contexts. We found that neuronal activity maintained representation of the identity and context of a recently categorized stimulus, as well as interpreted the behavioral meaningfulness of the maintained trace. The accuracy of this cognitive monitoring signal was highest for behavior for which subjects were prone to make errors. Thus, the caudate nucleus provides interpretive monitoring of ongoing behavior, which is necessary for contextually specific decisions to adapt to rapidly changing conditions. DOI: http://dx.doi.org/10.7554/eLife.03727.001 PMID:25415238

Yanike, Marianna; Ferrera, Vincent P

2014-01-01

292

Nucleus model for periodic Comet Tempel 2  

NASA Technical Reports Server (NTRS)

Observational data obtained primarily during 1988 are analyzed and synthesized to develop a comprehensive physical model for the nucleus of Periodic Comet Tempel 2, one of the best studied members of Jupiter's family of short-period comets. It is confirmed that a previous investigation provided reliable information on the comet's spin-axis orientation, which implies and obliquity of 54 degrees of the orbit plane to the equatorial plane and which appears to have varied little - if at all - with time. This conclusion is critical for fitting a triaxial ellipsoid to approximate the figure of the nucleus.

Sekanina, Zdenek

1991-01-01

293

Gene expression profile analysis of human mesenchymal stem cells from herniated and degenerated intervertebral discs reveals different expression of osteopontin.  

PubMed

Gene expression analysis provides an effective methodology to identify clinically relevant genes implicated in intervertebral disc (IVD) pathology. The analysis of gene profile in mesenchymal stem cells (MSCs) from human herniated IVD (H-IVD) and degenerated IVD (D-IVD) has not yet been investigated. We present in this study a characterization of MSCs isolated from clinically categorized H-IVD and D-IVD disc samples. H-IVD-MSCs and D-IVD-MSCs showed multipotent mesenchymal differentiation ability, expressing positivity for adipogenic, osteogenic, and chondrogenic markers with an immunophenotypical profile representative of MSCs. FACS analyses revealed a higher expression of CD44 in D-IVD-MSCs compared to H-IVD-MSCs. Gene expression profile revealed that most genes under investigation displayed large variations and were not significantly different in the two types of analyzed IVD-MSCs. Conversely, the gene expression of osteopontin (OPN), a protein involved in bone matrix mineralization and extracellular matrix destruction, was found markedly increased (more than 400-fold) in D-IVD-MSCs compared to H-IVD-MSCs. Moreover, the OPN protein expression was detectable only in D-IVD-MSCs, and its levels were directly related with D-IVD severity. These findings suggest that an abnormal expression of OPN in D-IVD-MSCs occurs and plays a pivotal role in the pathophysiological process of human disc degeneration. We speculate that the regulation of the OPN pathway might be a therapeutic target to counteract disc degeneration. PMID:25203751

Marfia, Giovanni; Navone, Stefania Elena; Di Vito, Clara; Tabano, Silvia; Giammattei, Lorenzo; Di Cristofori, Andrea; Gualtierotti, Roberta; Tremolada, Carlo; Zavanone, Mario; Caroli, Manuela; Torchia, Francesco; Miozzo, Monica; Rampini, Paolo; Riboni, Laura; Campanella, Rolando

2015-02-01

294

Oxygen-ozone therapy for herniated lumbar disc in patients with subacute partial motor weakness due to nerve root compression.  

PubMed

Intradiscal oxygen-ozone (O2-O3) chemonucleolysis is a well-known effective treatment for pain caused by protruding disc disease and nerve root compression due to bulging or herniated disc. The most widely used therapeutic combination is intradiscal injection of an O2-O3 mixture (chemonucleolysis), followed by periradicular injection of O2-O3, steroid and local anaesthetic to enhance the anti-inflammatory and analgesic effect. The treatment is designed to resolve pain and is administered to patients without motor weakness, whereas patients with acute paralysis caused by nerve root compression undergo surgery 24-48h after the onset of neurological deficit. This paper reports on the efficacy of O2-O3 chemonucleolysis associated with anti-inflammatory foraminal injection in 13 patients with low back pain and cruralgia, low back pain and sciatica and subacute partial motor weakness caused by nerve root compression unresponsive to medical treatment. All patients were managed in conjunction with our colleagues in the Neurosurgery Unit of Bellaria Hospital and the IRCCS Institute of Neurological Sciences, Bologna. The outcomes obtained are promising: 100% patients had a resolution of motor weakness, while 84.6% had complete pain relief. Our results demonstrate that O2-O3 therapy can be considered a valid treatment option for this category of patients. PMID:25363257

Dall'Olio, Massimo; Princiotta, Ciro; Cirillo, Luigi; Budai, Caterina; de Santis, Fabio; Bartolini, Stefano; Serchi, Elena; Leonardi, Marco

2014-10-31

295

Afferents to the Ventrolateral Preoptic Nucleus  

Microsoft Academic Search

Sleep is influenced by diverse factors such as circadian time, affective states, ambient temperature, pain, etc., but pathways mediating these influences are unknown. To identify pathways that may influence sleep, we examined afferents to the ventro- lateral preoptic nucleus (VLPO), an area critically implicated in promoting sleep. Injections of the retrograde tracer cholera toxin B subunit (CTB) into the VLPO

Thomas C. Chou; Alvhild A. Bjorkum; Stephanie E. Gaus; Jun Lu; Thomas E. Scammell; Clifford B. Saper

2002-01-01

296

Paraventricular nucleus, stress response, and cardiovascular disease  

Microsoft Academic Search

The paraventricular nucleus of the hypothalamus (PVN) is a complex effector structure that initiates endocrine and autonomic responses to stress. It receives inputs from visceral receptors, circulating hormones such as angiotensin II, and limbic circuits and contains neurons that release vasopressin, activate the adrenocortical axis, and activate preganglionic sympathetic or parasympathetic outflows. The neurochemical control of the different subgroups of

Eduardo E. Benarroch

2005-01-01

297

LSP-Nucleus Elastic Scattering Cross Sections  

E-print Network

We calculate LSP-nucleus elastic scattering cross sections using some representative input in the restricted SUSY parameter space. The coherent matrix elements are computed throughout the periodic table while the spin matrix elements for the proposed $^{207}Pb$ target which has a rather simple nuclear structure. The results are compared to those given from other cold dark matter detection targets.

J. D. Vergados; T. S. Kosmas

1997-01-02

298

Structure and Function in the Nucleus  

NSDL National Science Digital Library

Current evidence suggests that the nucleus has a distinct substructure, albeit one that is dynamic rather than a rigid framework. Viral infection, oncogene expression, and inherited human disorders can each cause profound and specific changes in nuclear organization. This review summarizes recent progress in understanding nuclear organization, highlighting in particular the dynamic aspects of nuclear structure.

Angus Lamond (University of Dundee;Department of Biochemistry); William Earnshaw (University of Edinburgh;Institute of Cell and Molecular Biology)

1998-04-24

299

Transport model of nucleon-nucleus reaction  

NASA Technical Reports Server (NTRS)

A simplified model of nucleon-nucleus reaction is developed and some of its properties are examined. Comparisons with proton production measured for targets of Al-27, Ni-58, Zr-90, and Bi-209 show some hope for developing an accurate model for these complex reactions. It is suggested that binding effects are the next step required for further development.

Wilson, J. W.; Townsend, L. W.; Cucinotta, F. A.

1986-01-01

300

Compound nucleus studies withy reverse kinematics  

SciTech Connect

Reverse kinematics reactions are used to demonstrate the compound nucleus origin of intermediate mass particles at low energies and the extension of the same mechanism at higher energies. No evidence has appeared in our energy range for liquid-vapor equilibrium or cold fragmentation mechanisms. 11 refs., 12 figs.

Moretto, L.G.

1985-06-01

301

The Retrotrapezoid Nucleus and Central Chemoreception  

Microsoft Academic Search

The functional role of retrotrapezoid nucleus (RTN) neurons as the central chemoreceptors and the potential implications of Phox2b expressed in these neurons will be discussed. RTN resides at the ventral medullary surface. RTN lesions reduce central respiratory chemoreception (CRC). RTN neurons are glutamatergic propriobulbar interneurons that selectively innervate the ventral respiratory column and other medullary regions essential to breathing. Their

Patrice G. Guyenet; Douglas A. Bayliss; Daniel K. Mulkey; Ruth L. Stornetta; Thiago S. Moreira; Ana T. Takakura

2008-01-01

302

Retrotrapezoid nucleus, respiratory chemosensitivity and breathing automaticity  

Microsoft Academic Search

Breathing automaticity and CO2 regulation are inseparable neural processes. The retrotrapezoid nucleus (RTN), a group of glutamatergic neurons that express the transcription factor Phox2b, may be a crucial nodal point through which breathing automaticity is regulated to maintain CO2 constant. This review updates the analysis presented in prior publications. Additional evidence that RTN neurons have central respiratory chemoreceptor properties is

Patrice G. Guyenet; Douglas A. Bayliss; Ruth L. Stornetta; Michal G. Fortuna; Stephen B. G. Abbott; Seth D. DePuy

2009-01-01

303

The Role of the Nucleus in Oxidation  

Microsoft Academic Search

Injury produces in the leaf-cells of the Indian Pipe (Monotropa uniflora) a darkening which is due to oxidation. The oxidation is much more rapid in the nucleus than in the cytoplasm and the facts indicate that this is also the case with the oxidation of the uninjured cell

W. J. V. Osterhout

1917-01-01

304

THE ROLE OF THE NUCLEUS IN OXIDATION.  

PubMed

Injury produces in the leaf-cells of the Indian Pipe (Monotropa uniflora) a darkening which is due to oxidation. The oxidation is much more rapid in the nucleus than in the cytoplasm and the facts indicate that this is also the case with the oxidation of the uninjured cell. PMID:17758977

Osterhout, W J

1917-10-12

305

Evaporation from a porous cometary nucleus  

NASA Astrophysics Data System (ADS)

In a porous cometary nucleus, ice sublimates from the volume of a surface layer rather than just from the upper boundary. Given a model for the porous medium, the equations of mass and heat transfer can be solved for any desired orbit. The temperature profile and the vapor flux as a function of depth in the upper layer of the nucleus may thus be obtained. Calculations are performed for a spherically symmetric icy nucleus in the orbit of Comet P/Halley, assuming different values of porosity and different models for the ice structure. The upper layer may be divided in two zones: in the uppermost zone, whose thickness ranges from 100 microns to about 1 mm, the vapor flux is directed outward, whereas in the lower zone, which is 1000 times thicker, the vapor flows in the opposite direction. The sublimation rate as a function of heliocentric distance depends strongly on the porosity of the nucleus and is little affected by other parameters related to the structure of the ice. This allows the determination of the porosity coefficient of a comet from observation of its water production rates at large heliocentric distances.

Mekler, Y.; Prialnik, D.; Podolak, M.

1990-06-01

306

Fusion cross sections for reactions involving medium & heavy nucleus-nucleus systems  

E-print Network

Existing data on near-barrier fusion excitation functions of medium and heavy nucleus-nucleus systems have been analyzed using a simple diffused barrier formula derived assuming the Gaussian shape of the barrier height distributions. Fusion cross section is obtained by folding the Gaussian barrier distribution with the classical expression for the fusion cross section for a fixed barrier. The energy dependence of the fusion cross section, thus obtained, provides good description to the existing data on near-barrier fusion and capture excitation functions for medium and heavy nucleus-nucleus systems. The fusion or capture cross section predictions are especially important for planning experiments for synthesizing new super-heavy elements.

Debasis Atta; D. N. Basu

2014-02-20

307

Fusion cross sections for reactions involving medium and heavy nucleus-nucleus systems  

NASA Astrophysics Data System (ADS)

Existing data on near-barrier fusion excitation functions of medium and heavy nucleus-nucleus systems have been analyzed by using a simple diffused-barrier formula derived assuming the Gaussian shape of the barrier-height distributions. The fusion cross section is obtained by folding the Gaussian barrier distribution with the classical expression for the fusion cross section for a fixed barrier. The energy dependence of the fusion cross section, thus obtained, provides good description to the existing data on near-barrier fusion and capture excitation functions for medium and heavy nucleus-nucleus systems. The theoretical values for the parameters of the barrier distribution are estimated which can be used for fusion or capture cross-section predictions that are especially important for planning experiments for synthesizing new superheavy elements.

Atta, Debasis; Basu, D. N.

2014-12-01

308

Ultrastructure of synaptic terminals in nucleus infundibularis and nucleus supraopticus of Passer domesticus  

Microsoft Academic Search

Axo-dendritic and axo-somatic synapses and complex axo-dendritic junctions from the nucleus infundibularis and nucleus supraopticus of Passer domesticus were studied in the electron microscope. A morphological asymmetry, represented by clustering of synaptic vesicles (of about 500 Å diameter) at the presynaptic membrane and a thickening of and subsynaptic web formation at the postsynaptic membrane, was observed in the axo-dendritic and

J. Priedkalns; A. Oksche

1969-01-01

309

Results on ultra-relativistic nucleus-nucleus interactions from balloon-borne emulsion chambers  

NASA Technical Reports Server (NTRS)

The results of balloon-borne emulsion-chamber measurements on high-energy cosmic-ray nuclei (Burnett et al., 1983) are summarized in tables and graphs and briefly characterized. Special consideration is given to seven nucleus-nucleus interaction events at energy in excess of 1 TeV/A with multiplicity greater than 400, and to Fe interactions (53 with CHO, 10 with emulsion, and 14 with Pb) at 20-60 GeV/A.

Burnett, T. H.; Dake, S.; Derrickson, J. H.; Fountain, W.; Meegan, C. A.; Takahashi, Y.; Watts, J. W.; Fuki, M.; Gregory, J. C.; Hayashi, T.

1985-01-01

310

Systematic investigation of scaled factorial cumulant moments for nucleus-nucleus interactions  

SciTech Connect

We use scaled factorial cumulant moments to analyze pseudorapidity fluctuations in nucleus-nucleus collisions. This approach is similar to the method of scaled factorial moments except that it removes the effects of lower-order correlations upon a given moment. Significant second-order cumulants and cumulant indices (slopes with respect to bin size) are found for all of the interactions studied. These indices are found to have an inverse dependence upon average pseudorapidity particle density.

Adamovich, M.I.; Aggarwal, M.M.; Alexandrov, Y.A.; Andreeva, N.P.; Anson, Z.V.; Arora, R.; Avetyan, F.A.; Badyal, S.K.; Basova, E.; Bazarov, I.K.; Bhalla, K.B.; Bhasin, A.; Bhatia, V.S.; Bogdanov, V.G.; Bubnov, V.I.; Burnett, T.H.; Cai, X.; Carshiev, D.A.; Chasnicov, I.Y.; Chernova, L.P.; Chernyavski, M.M.; Eligbaeva, G.Z.; Eremenko, L.E.; Gaitinov, A.S.; Ganssauge, E.R.; Garpman, S.; Gerassimov, S.G.; Grote, J.G.; Gulamov, K.G.; Gupta, S.K.; Gupta, V.K.; Heckman, H.H.; Huang, H.; Jacobsson, B.; Judek, B.; Kachroo, S.; Kalyachkina, G.S.; Kanygina, E.K.; Karabova, M.; Kharlamov, S.P.; Kitroo, S.; Koss, T.; Krasnov, S.A.; Kumar, V.; Lal, P.; Larionova, V.G.; Lepetan, V.N.; Liu, L.S.; Lokanathan, S.; Lord, J.J.; Lukicheva, N.S.; Luo, S.B.; Mangotra, L.K.; Marutyan, N.A.; Maslennikova, N.V.; Mittra, I.S.; Mookerjee, S.; Nasyrov, S.Z.; Navotny, V.S.; Nystrand, J.; Orlova, G.I.; Otterlund, I.; Palsania, H.; Peresadko, N.G.; Petrov, N.V.; Plyuschev, V.A.; Qian, W.Y.; Qin, Y.M.; Raniwala, R.; (The EMU01 Collaboration)

1993-05-01

311

Average transverse momentum and energy density in high-energy nucleus-nucleus collisions  

NASA Technical Reports Server (NTRS)

Emulsion chambers were used to measure the transverse momenta of photons or pi(0) mesons produced in high-energy cosmic-ray nucleus-nucleus collisions. A group of events having large average transverse momenta has been found which apparently exceeds the expected limiting values. Analysis of the events at early interaction times, of the order of 1 fm/c, indicates that the observed transverse momentum increases with both rapidity density and energy density.

Burnett, T. H.; Dake, S.; Fuki, M.; Gregory, J. C.; Hayashi, T.; Holynski, R.; Iwai, J.; Jones, W. V.; Jurak, A.; Lord, J. J.

1986-01-01

312

A combined biomaterial and cellular approach for annulus fibrosus rupture repair.  

PubMed

Recurrent intervertebral disc (IVD) herniation and degenerative disc disease have been identified as the most important factors contributing to persistent pain and disability after surgical discectomy. An annulus fibrosus (AF) closure device that provides immediate closure of the AF rupture, restores disc height, reduces further disc degeneration and enhances self-repair capacities is an unmet clinical need. In this study, a poly(trimethylene carbonate) (PTMC) scaffold seeded with human bone marrow derived mesenchymal stromal cells (MSCs) and covered with a poly(ester-urethane) (PU) membrane was assessed for AF rupture repair in a bovine organ culture annulotomy model under dynamic load for 14 days. PTMC scaffolds combined with the sutured PU membrane restored disc height of annulotomized discs and prevented herniation of nucleus pulposus (NP) tissue. Implanted MSCs showed an up-regulated gene expression of type V collagen, a potential AF marker, indicating in situ differentiation capability. Furthermore, MSCs delivered within PTMC scaffolds induced an up-regulation of anabolic gene expression and down-regulation of catabolic gene expression in adjacent native disc tissue. In conclusion, the combined biomaterial and cellular approach has the potential to hinder herniation of NP tissue, stabilize disc height, and positively modulate cell phenotype of native disc tissue. PMID:25542789

Pirvu, Tatiana; Blanquer, Sebastien B G; Benneker, Lorin M; Grijpma, Dirk W; Richards, Robert G; Alini, Mauro; Eglin, David; Grad, Sibylle; Li, Zhen

2015-02-01

313

Brackett Gamma Imaging of the Nucleus of M83  

Microsoft Academic Search

The gas-rich nucleus of barred spiral galaxy, M83, is a hotbed of star formation, with a total infrared luminosity of 4 X 109 Lo. We have observed the nucleus of M83 with the near infrared spectrometer, NIRSPEC, on Keck 2 to obtain high resolution Brgamma recombination line spectra of the nucleus. Simultaneous imaging with the SCAM camera in a broadband

L. P. Crosthwaite; J. L. Turner; S. C. Beck; D. S. Meier

2004-01-01

314

Inclusive quasielastic electron-nucleus scattering  

SciTech Connect

This paper presents a review on the field of inclusive quasielastic electron-nucleus scattering. It discusses the approach used to measure the data and includes a compilation of data available in numerical form. The theoretical approaches used to interpret the data are presented. A number of results obtained from the comparison between experiment and calculation are then reviewed. The analogies to, and differences from, other fields of physics exploiting quasielastic scattering from composite systems are pointed out.

Benhar, Omar; Day, Donal; Sick, Ingo [INFN, Sezione di Roma, I-00185 Roma (Italy) and Dipartimento di Fisica, Universita 'La Sapienza', I-00185 Roma (Italy); Department of Physics, University of Virginia, Charlottesville, Virginia 22903 (United States); Departement fuer Physik und Astronomie, Universitaet Basel, CH-4056 Basel (Switzerland)

2008-01-15

315

Spectrophotometry of comets. [cometary nucleus model  

NASA Technical Reports Server (NTRS)

Photoelectric spectrophotometric- and image tube equipped spectrographic-studies on comets are used to formulate a new model for the cometary nucleus that is physically similar to the icy-conglomerate. Absolute flux distributions of the principal spectral features for five comets of different compositions and heliocentric distances were evaluated. Comparison of visible and infrared brightnesses was used to calculate the optical albedos of observed particles.

Odell, C. R.

1974-01-01

316

Subthalamic nucleus stimulation in Parkinson's disease  

Microsoft Academic Search

The aim of the present study was to assess the efficacy and safety of chronic subthalamic nucleus deep-brain stimulation\\u000a (STN-DBS) in patients with Parkinson's disease (PD). 18 consecutive severely affected PD patients were included (mean age,\\u000a SD: 56.9±6 years; mean disease duration: 13.5±4.4 years). All the patients were evaluated clinically before and 6 months after\\u000a the surgical procedure using the

S. Thobois; P. Mertens; M. Guenot; M. Hermier; H. Mollion; M. Bouvard; G. Chazot; E. Broussolle; M. Sindou

2002-01-01

317

The Dusty Starburst Nucleus of M33  

Microsoft Academic Search

We have thoroughly characterized the ultraviolet to near-infrared (0.15-2.2 mum) spectral energy distribution (SED) of the central parsec of the M33 nucleus through new infrared photometry and optical\\/near-infrared spectroscopy, combined with ultraviolet\\/optical observations from the literature and the Hubble Space Telescope archive. The SED shows evidence for a significant level of attenuation, which we model through a Monte Carlo radiative

Karl D. Gordon; M. M. Hanson; Geoffrey C. Clayton; G. H. Rieke; K. A. Misselt

1999-01-01

318

Theoretical highlights of neutrino-nucleus interactions  

SciTech Connect

The recent theoretical developments in the field of neutrino-nucleus interactions in the few-GeV region are reviewed based on the presentations made at the NuInt09 Workshop. The topics of electron scattering and its connections with neutrino interactions, neutrino induced quasielastic scattering and pion production (coherent and incoherent) are covered, with special emphasis on the challenges that arise in the comparison with new experimental data.

Alvarez-Ruso, Luis [Centro de Fisica Computacional, Departamento de Fisica, Universidade de Coimbra (Portugal)

2010-03-30

319

Possible Mechanisms of Low Back Pain due to Whole-Body Vibration  

NASA Astrophysics Data System (ADS)

The investigators describe their multifaceted approach to the study of the relationship between whole-body vibration and low back pain.In vitroexperiments, using percutaneous pin-mounted accelerometers have shown that the natural frequency is at 4·5 Hz. The frequency response was affected by posture, seating, and seat-back inclination. The response appears to be largely determined by the rocking of the pelvis. Electromyographic studies have shown that muscle fatigue occurs under whole body vibration. After whole body vibration exposure the muscle response to a sudden load has greater latency. Vehicle driving may be a reason for low back pain or herniated nucleus pulposus. Prolonged seating exposure, coupled with the whole body vibration should be reduced for those recovering from these problems. Vibration attenuating seats, and correct ergonomic layout of the cabs may reduce the risks of recurrence.

Pope, M. H.; Wilder, D. G.; Magnusson, M.

1998-08-01

320

PTEN enters the nucleus by diffusion.  

PubMed

Despite much evidence for phosphatidylinositol phosphate (PIP)-triggered signaling pathways in the nucleus, there is little understanding of how the levels and activities of these proteins are regulated. As a first step to elucidating this problem, we determined whether phosphatase and tensin homolog deleted on chromosome 10 (PTEN) enters the nucleus by passive diffusion or active transport. We expressed various PTEN fusion proteins in tsBN2, HeLa, LNCaP, and U87MG cells and determined that the largest PTEN fusion proteins showed little or no nuclear localization. Because diffusion through nuclear pores is limited to proteins of 60,000 Da or less, this suggests that nuclear translocation of PTEN occurs via diffusion. We examined PTEN mutants, seeking to identify a nuclear localization signal (NLS) for PTEN. Mutation of K13 and R14 decreased nuclear localization, but these amino acids do not appear to be part of an NLS. We used fluorescence recovery after photobleaching (FRAP) to demonstrate that GFP-PTEN can passively pass through nuclear pores. Diffusion in the cytoplasm is retarded for the PTEN mutants that show reduced nuclear localization. We conclude that PTEN enters the nucleus by diffusion. In addition, sequestration of PTEN in the cytoplasm likely limits PTEN nuclear translocation. PMID:16088943

Liu, Fenghua; Wagner, Stefan; Campbell, Robert B; Nickerson, Jeffrey A; Schiffer, Celia A; Ross, Alonzo H

2005-10-01

321

A unified approach to hadron-hadron, hadron-nucleus and nucleus-nucleus collisions at high energy  

SciTech Connect

The problem of multiparticle production in high-energy hadron-hadron, hadron-nucleus and nucleus-nucleus collisions are studied systematically in the framework of the Geometrical Branching (GBM). The model is based on the geometrical properties of nucleons and the stochastic nature of the interaction among the soft partons. The eikonal formalism is used to relate the elastic and inelastic cross sections and AGK cutting rule is used in connection with the multiparticle production process. The stochastic process of Furry branching is employed to describe the proliferation and hadronization of partons which lead to the produced particles. The approach describes hh, hA and AA collisions in a unified formalism for c.m. energies less than 100 GeV. The result of multiplicity distribution of produced particles exhibits Koba-Nielsen-Olesen (KNO) scaling. The universality of KNO scaling breaks down due to the different geometrical sizes of the hadron and nuclei. For hA and AA collisions, the formalism of GBM allows the hadron to be broken (to h{prime}) by the first collision; indeed, it in the attention given to h{prime}h and h{prime}h{prime} collisions that distinguishes this work from other earlier investigations on the subject. All of the calculated results are in good agreement with experiments. A general Monte Carlo simulation of GBM for multiparticle production in hh, hA and AA collisions is also given. The particle productivity in particular is studied in detail and is contrasted from the case where quark-gluon plasma (QGP) is produced in the AA collisions. This work forms a definitive description of hadronic and nuclear collisions that can serve as a basis from which exotic features such as the formation of QGP can be recognized as signatures deviating from the normal background.

Wang, Xinnian.

1989-01-01

322

a Unified Approach to Hadron-Hadron Hadron-Nucleus and Nucleus-Nucleus Collisions at High Energy  

NASA Astrophysics Data System (ADS)

The problem of multiparticle production in high -energy hadron-hadron, hadron-nucleus and nucleus-nucleus collisions are studied systematically in the framework of the Geometrical Branching Model (GBM). The model is based on the geometrical properties of nucleons and the stochastic nature of the interaction among the soft partons. The eikonal formalism is used to relate the elastic and inelastic cross sections and AGK cutting rule is used in connection with the multiparticle production process. The stochastic process of Furry branching is employed to describe the proliferation and hadronization of partons which lead to the produced particles. The approach describes hh, hA and AA collisions in a unified formalism for c.m. energies less than 100 GeV. The result of multiplicity distribution of produced particles exhibits Koba-Nielsen-Olesen (KNO) scaling. The universality of KNO scaling breaks down due to the different geometrical sizes of the hadron and nuclei. For hA and AA collisions, the formalism of GBM allows the hadron to be broken (to h^') by the first collision; indeed, it is the attention given to h^'h and h ^'h^' collisions that distinguishes this work from other earlier investigations on the subject. All of the calculated results are in good agreement with experiments. A general Monte Carlo simulation of GBM for multiparticle production in hh, hA and AA collisions is also given. The particle productivity in particular is studied in detail and is contrasted from the case where quark-gluon plasma (QGP) is produced in the AA collisions. This work forms a definitive description of hadronic and nuclear collisions that can serve as a basis from which exotic features such as the formation of QGP can be recognized as signatures deviating from the normal background.

Wang, Xin-Nian

323

Effects of Acupuncture, Core-stability Exercises, and Treadmill Walking Exercises in Treating a Patient with Postsurgical Lumbar Disc Herniation: A Clinical Case Report.  

PubMed

The objective of this study is to investigate the effects of acupuncture, core-stability exercises, and treadmill 12-minute walking exercises in treating patients with postsurgical lumbar disc herniation. A 34-year-old woman with a history lumbar disc prolapse who had undergone lumbar disc surgery on two different occasions was treated using acupuncture, core-stability exercises, and treadmill walking exercises three times per week for 12 weeks. The outcome measures used in this study were pain intensity, spinal range of movement, and general health. After 12 weeks of treatment, the patient had made improvement in terms of pain, which was reduced from 9/10 to 1/10. In a similar vein, the patient's general health showed improvement of >100% after 12 weeks of treatment. Pre-treatment scores of spinal flexion and left-side flexion, which measured 20 cm and 12 cm, respectively, increased to 25 cm and 16 cm after 12 weeks of treatment. This study showed that acupuncture, core-stability exercises, and treadmill walking exercises were useful in relieving pain, increasing spinal range of movement, and improving the health of a patient with postsurgical lumbar disc herniation. PMID:25660445

Ganiyu, Sokunbi Oluwaleke; Gujba, Kachalla Fatimah

2015-02-01

324

Herniation of Duodenum into the Right Ventral Hepatic Peritoneal Cavity with Groove Formation at the Ventral Hepatic Surface in a 2-Week-Old Chicken  

PubMed Central

ABSTRACT Internal hernia in avian species is very rare. A necropsy of a 2-week-old SPF White Leghorn chicken revealed that a loop of the duodenum and part of the pancreas (4 × 2 × 1 cm) was protruding through the abnormal foramen (2.5 cm in diameter) in the right posthepatic septum into the right ventral hepatic peritoneal cavity. The herniated loop was located underneath the ventral hepatic surface, leaving a groove on the right hepatic lobe (2 × 1.5 × 0.4 cm). The part of the pancreas involved in the hernia was grossly enlarged. Microscopically, a zone of pressure atrophy of hepatic tissue was characterized by crowdedness of hepatocytes with pyknotic nuclei and faint eosinophilic cytoplasm and indistinct narrow sinusoids. The pancreas revealed hypertrophy of the acinar cells with an increase in the secretory granules and basophilic cytoplasm. This is the first report of duodenum herniation into the right ventral hepatic peritoneal cavity resulting in groove formation on the ventral hepatic surface in a 2-week-old chicken. PMID:23759688

HARIDY, Mohie; SASAKI, Jun; GORYO, Masanobu

2013-01-01

325

Nucleus-nucleus interactions between 20 and 65 GeV per nucleon  

SciTech Connect

A hybrid electronic-counter--emulsion-chamber instrument was exposed to high-energy cosmic rays on a balloon. The data on 105 nucleus-nucleus collisions in the energy range 20--65 GeV/nucleon and for incident nuclear charges 22less than or equal toZ/sub p/less than or equal to28 are presented. Inclusive characteristics of particle production on different targets (plastic, emulsion, and lead) are shown and compared with models based on the superposition of nucleon-nucleus interactions. Features of a subset of the more central collisions with plastic target and some characteristics of individual events with the highest multiplicity of produced particles are described.

Burnett, T.H.; Dake, S.; Derrickson, J.H.; Fountain, W.F.; Fuki, M.; Gregory, J.C.; Hayashi, T.; Hayashi, T.; Holynski, R.; Iwai, J.; and others

1987-02-01

326

Analysis of nucleus-nucleus collisions at high energies and Random Matrix Theory  

E-print Network

We propose a novel statistical approach to the analysis of experimental data obtained in nucleus-nucleus collisions at high energies which borrows from methods developed within the context of Random Matrix Theory. It is applied to the detection of correlations in momentum distributions of emitted particles. We find good agreement between the results obtained in this way and a standard analysis based on the method of effective mass spectra and two-pair correlation function often used in high energy physics. The method introduced here is free from unwanted background contributions.

R. G. Nazmitdinov; E. I. Shahaliev; M. K. Suleymanov; S. Tomsovic

2008-04-07

327

Pion and Kaon Lab Frame Differential Cross Sections for Intermediate Energy Nucleus-Nucleus Collisions  

NASA Technical Reports Server (NTRS)

Space radiation transport codes require accurate models for hadron production in intermediate energy nucleus-nucleus collisions. Codes require cross sections to be written in terms of lab frame variables and it is important to be able to verify models against experimental data in the lab frame. Several models are compared to lab frame data. It is found that models based on algebraic parameterizations are unable to describe intermediate energy differential cross section data. However, simple thermal model parameterizations, when appropriately transformed from the center of momentum to the lab frame, are able to account for the data.

Norbury, John W.; Blattnig, Steve R.

2008-01-01

328

The Dusty Starburst Nucleus of M33  

NASA Astrophysics Data System (ADS)

We have thoroughly characterized the ultraviolet to near-infrared (0.15-2.2 ?m) spectral energy distribution (SED) of the central parsec of the M33 nucleus through new infrared photometry and optical/near-infrared spectroscopy, combined with ultraviolet/optical observations from the literature and the Hubble Space Telescope archive. The SED shows evidence for a significant level of attenuation, which we model through a Monte Carlo radiative transfer code as a shell of clumpy Milky Way-type dust (?V~2+/-1). The discovery of Milky Way-type dust (with a strong 2175 Å bump) internal to the M33 nucleus is different from previous work, which has found SMC-like dust (no bump) near starburst regions. The amount by which dust can be processed may be related to the mass and age of the starburst as well as the extent to which the dust can shield itself. Our starburst models include the effects of this dust and can fit the SED if the nucleus was the site of a moderate (~108 Lsolar at 10 Myr) episode of coeval star formation about 70 Myr ago. This result is quite different from previous studies, which resorted to multiple stellar populations (between two and seven) attenuated by either no or very little internal dust. The M33 nuclear starburst is remarkably similar to an older version (70 versus 10 Myr) of the ultracompact starburst in the center of the Milky Way. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Gordon, Karl D.; Hanson, M. M.; Clayton, Geoffrey C.; Rieke, G. H.; Misselt, K. A.

1999-07-01

329

Comparative analysis of serum proteomes: Identification of proteins associated with sciatica due to lumbar intervertebral disc herniation  

PubMed Central

Lumbar intervertebral disc herniation (LDH) is one of the most common orthopedic conditions that can cause lower back pain and sciatica. However, the pathogenesis of LDH is poorly understood. The aim of the present study was to use proteomic analysis of blood samples to establish whether there are serum proteins associated with LDH, which may be useful in elucidating LDH pathogenesis. The ultimate aim was to develop a simple technique for the diagnosis of LDH based on the blood samples of patients with sciatica. The study used comparative analysis of serum proteomes associated with sciatica due to LDH. A total of 30 LDH patients with sciatica, receiving treatment between August and December 2007, were selected as the experimental group (or LDH group). A total of 2 ml of blood was obtained from each of the 30 patients in the LDH group and from 30 healthy volunteers, who constituted the control group. Two-dimensional electrophoresis of the blood samples was conducted, distinct protein spots were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and proteins associated with LDH were detected. An enzyme-linked immunosorbent assay (ELISA) was developed to screen for the LDH proteins and was tested on the sera of a second test and control group that included 10 patients with LDH and 10 healthy subjects, respectively. Based on signal intensity, the expression levels of 6 proteins on the dielectrophoretogram were found to be significantly associated with LDH. The identities of the LDH proteins were upregulated apolipoprotein-L1 (APO-L1) and two types of serum albumin precursors, and downregulated apolipoprotein M (APO-M), tetranectin (TN) and immunoglobulin light chain (IGL). Further ELISA experiments confirmed that there were increased serum levels of 4 out of the 6 proteins in patients with sciatica due to LDH, which was statistically different compared to the healthy subjects. In conclusion, these results suggest that serum APO-L1, TN, APO-M and IGL may serve as LDH biomarkers. PMID:25054013

XIE, PEIGEN; LIU, BIN; CHEN, RUIQIANG; YANG, BU; DONG, JIANWEN; RONG, LIMIN

2014-01-01

330

Dielectron Production in Proton-Nucleus Reactions  

E-print Network

PHYSICAL REVIEW C VOLUME 41, NUMBER 4 Dielectron production in proton-nucleus reactions APRIL 1990 L. Xiong, J. Q. Wu, Z. G. Wu, C. M. Ko, and J. H. Shi Cyclotron Institute, Center for Theoretical Physics and Physics Department, Texas Act...-nucleon inelastic scatterings with their masses be- ing determined according to the following probability dis- tribution R1355 1990 The American Physical Society R1356 L. XIONG, J. Q. WU, Z. G. WU, C. M. KO, AND J. H. SHI with invariant mass M can be evaluated...

Xiong, L.; Wu, J. Q.; Wu, Z. G.; Ko, Che Ming; Shi, J. H.

1990-01-01

331

Neutrino-nucleus scattering off 136Xe  

NASA Astrophysics Data System (ADS)

Background: Theoretical estimates of the cross sections for the neutrino-nucleus scattering off relevant nuclei for supernova neutrinos are essential for many applications in neutrino physics and astrophysics. The double-? -decaying nucleus 136Xe nucleus is used by the EXO Collaboration in the search for neutrinoless double-? decay. A ton-scale experiment based on 136Xe could also be used for studies of supernova neutrinos and/or solar neutrinos. Purpose: The purpose of the present work is, thus, to perform a study of the charged-current and neutral-current nuclear responses to supernova neutrinos for 136Xe . Method: The cross sections are computed by using the well-established framework for studies of semileptonic processes in nuclei introduced by O'Connell, Donnelly, and Walecka [Phys. Rev. C 6, 719 (1972), 10.1103/PhysRevC.6.719]. The nuclear wave functions of the initial and the final nuclear states for the neutral-current neutrino-nucleus scattering in 136Xe are computed by using the quasiparticle random-phase approximation (QRPA). Similarly, the pnQRPA is adopted to construct the initial and final nuclear states which are relevant for the charged-current reactions. The nuclear responses to supernova neutrinos are subsequently computed by folding the cross sections with appropriate energy spectra for the incoming neutrinos. Results: We present results for the cross sections of the charged-current and neutral-current neutrino and antineutrino scatterings off 136Xe . Nuclear responses to supernova neutrinos are also given. For the considered scenario for the neutrino mixing we have found that neutrino interactions with matter and so-called collective neutrino oscillations enhance significantly the neutrino and antineutrino flux-averaged cross sections. Conclusions: We have found that for the charged-current and neutral-current neutrino scatterings off 136Xe transitions mediated by the 1+ multipole are the most important ones. However, for the charged-current antineutrino channel 0+ and 1+ transitions are largely suppressed due to the large neutron excess. Transitions to 1- and 2- final nuclear states are thus relatively more important for the charged-current antineutrino scattering.

Ydrefors, E.; Suhonen, J.; Zhao, Y. M.

2015-01-01

332

Formation, structure, and evolution of boiling nucleus and interfacial tension between bulk liquid phase and nucleus  

Microsoft Academic Search

In this paper, the concept of the molecular free path is introduced to derive a criterion distinguishing active molecules from inactive molecules in liquid phase. A concept of the critical aggregation concentration (CAC) of active molecules is proposed to describe the physical configuration before the formation of a nucleus during vapor–liquid phase transition. All active molecules exist as monomers when

Xiao-Dong Wang; Xiao-Feng Peng; Yong Tian; Bu-Xuan Wang

2005-01-01

333

Effects of a chiral three-nucleon force on nucleus-nucleus scattering  

NASA Astrophysics Data System (ADS)

We investigate the effects of next-to-next-to leading order (NNLO) chiral three-nucleon force (3NF) on nucleus-nucleus elastic scattering, using a standard prescription based on the Brueckner-Hartree-Fock method and the g -matrix folding model. The g -matrix calculated in nuclear matter from the next-to-next-to-next-to leading order (N3LO) chiral two-nucleon forces (2NF) is close to that from the Bonn-B 2NF. Since the Melbourne group has already developed a practical g -matrix interaction by localizing the nonlocal g -matrix calculated from the Bonn-B 2NF, as this first attempt we consider the effects of chiral 3NF by modifying the local Melbourne g matrix according to the difference between the g matrices of the chiral 2NF and 2NF+3NF. For nucleus-nucleus elastic scattering, the 3NF corrections make the folding potential less attractive and more absorptive. The latter effect is due to the enhanced tensor correlations in triplet channels. These changes reduce the differential cross section at middle and large angles and improve the agreement with the experimental data for 16O-16O scattering at 70 MeV/nucleon and 12C-12C scattering at 85 MeV/nucleon.

Minomo, Kosho; Toyokawa, Masakazu; Kohno, Michio; Yahiro, Masanobu

2014-11-01

334

[A new approach to the biomechanics of the normal and pathologic lumbar disk using the finite element method].  

PubMed

The model was created based on the L2-L3 intervertebral disc considering it to be symmetrical on a longitudinal axis and a mid-transverse plane and could be subjected to a longitudinal load of 400 N in compression. The analysis of this two-dimensional problem by using the finite element program S.A.M.C.E.F. utilizes a quadrangular isoparametric and axi-symmetric element. The results took into account the vertical deflection and radial displacement of the nodal points and also the deformation diagram and stress distribution (Von Mises comparison) of the three regions studied: nucleus pulposus, annulus fibrosus and the end plate. This model has been applied to three pathological states: fissuring of the annulus and nucleus herniation, simulation of an enucleation, and a fracture of the central area of end plate with Schmörl's nodule formation. In each case, a deformation and a stress distribution modified relatively to those observed in normal discs were obtained. For instance, in the case of herniation the maximum stress equals 3.700 N/mm2 in comparison with 1.350 N/mm2 found in normal cases. This simplified model is one of the first which reproduces some pathological states of intervertebral discs and facilitates the understanding of the biomechanics of these states. PMID:2801092

Stan, S; Coulon, E; Mosora, F

1989-01-01

335

On M31's Double Nucleus  

NASA Technical Reports Server (NTRS)

The recent HST discovery of a double nucleus in M31 brings into prominence the question how long, a second core can survive within the nuclear regions of a galaxy. Physical conditions in the nuclear regions of a typical galaxy help a second core survive, so it can orbit for a long time. possibly for thousands of orbits. Given the nearly uniform mass density in a core, tidal forces within a core radius are compressive in all directions and help the core survive the buffeting it takes as it orbits near the center of the galaxy. We use numerical experiments to illustrate these physical principles. Our method allows the full power of the experiments to be concentrated on the nuclear regions. Spatial resolution of about 0.2 pc comfortably resolves detail within the 1.4 parsec core radius of the second, but brighter core (P1) in M31. We use these physical principles to discuss M31's double nucleus, but they apply to other galaxies as well. and in other astronomical situations such as dumbbell galaxies. galaxies orbiting near the center of a galaxy cluster, and subclustering in galaxy clusters. The experiments also illustrate that galaxy encounters and merging are quite sensitive to external tidal forces, such as those produced by the gravitational potential in a group or cluster of galaxies.

Miller, R. H.; Smith, B. F.; Cuzzi, Jeffrey (Technical Monitor)

1995-01-01

336

The median raphe nucleus in anxiety revisited.  

PubMed

Although the role of the median raphe nucleus (MRN) in the regulation of anxiety has received less attention than that of the dorsal raphe nucleus (DRN) there is substantial evidence supporting this function. Reported results with different animal models of anxiety in rats show that whereas inactivation of serotonergic neurons in the MRN causes anxiolysis, the stimulation of the same neurons is anxiogenic. In particular, studies using the elevated T-maze comparing serotonergic interventions in the MRN and in the DRN indicate that the former affect only the inhibitory avoidance task, which has been related to generalized anxiety. In contrast, similar operations in the DRN change both the inhibitory avoidance and the one-way escape task, the latter being representative of panic disorder. Simultaneous injections of 5-HT-acting drugs in the MRN and in the dorsal hippocampus (DH) suggest that the MRN-DH pathway mediates the regulatory function of the MRN in anxiety. Overall, the results discussed in this review point to a relevant role of the MRN in the regulation of anxiety, but not panic, through the 5-HT pathway that innervates the DH. PMID:23999409

Andrade, Telma Gcs; Zangrossi, Hélio; Graeff, Frederico G

2013-12-01

337

How dynein and microtubules rotate the nucleus.  

PubMed

In living cells, a fluctuating torque is exerted on the nuclear surface but the origin of the torque is unclear. In this study, we found that the nuclear rotation angle is directionally persistent on a time scale of tens of minutes, but rotationally diffusive on longer time scales. Rotation required the activity of the microtubule motor dynein. We formulated a model based on microtubules undergoing dynamic instability, with tensional forces between a stationary centrosome and the nuclear surface mediated by dynein. Model simulations suggest that the persistence in rotation angle is due to the transient asymmetric configuration of microtubules exerting a net torque in one direction until the configuration is again randomized by dynamic instability. The model predicts that the rotational magnitude must depend on the distance between the nucleus and the centrosome. To test this prediction, rotation was quantified in patterned cells in which the cell's centrosome was close to the projected nuclear centroid. Consistent with the prediction, the angular displacement was found to decrease in these cells relative to unpatterned cells. This work provides the first mechanistic explanation for how nuclear dynein interactions with discrete microtubules emanating from a stationary centrosome cause rotational torque on the nucleus. PMID:21792925

Wu, Jun; Lee, Kristen C; Dickinson, Richard B; Lele, Tanmay P

2011-10-01

338

Scaling properties of proton-nucleus total reaction cross sections  

E-print Network

We study the scaling properties of proton-nucleus total reaction cross sections for stable nuclei and propose an approximate expression in proportion to Z^{2/3}\\sigma_{pp}^{total} + N^{2/3} \\sigma_{pn}^{total}. Based on this expression, we can derive a relation that enables us to predict a total reaction cross section for any stable nucleus within 10% uncertainty at most, using the empirical value of the total reaction cross section of a given nucleus.

Badawy Abu-Ibrahim; Akihisa Kohama

2010-05-03

339

Organization of the disynaptic pathway from the anteroventral cochlear nucleus to the lateral superior olivary nucleus in the ferret  

Microsoft Academic Search

The medial nucleus of the trapezoid body (MNTB) is one of three major nuclei of the superior olivary complex and provides\\u000a an important inhibitory input from the contralateral ear to the lateral superior olivary nucleus (LSO) in the initial binaural\\u000a pathway for coding interaural intensity differences. The major input to the MNTB from the contralateral anteroventral cochlear\\u000a nucleus (AVCN) involves

C. K. Henkel; Mark L. Gabriele

1999-01-01

340

Glasgow Theses Service http://theses.gla.ac.uk/  

E-print Network

comprised of the nucleus pulposus and the annulus fibrosus. The nucleus pulposus is the gelatinous core for the Degree of Doctor of Philosophy School of Engineering University of Glasgow November 2012 #12;Declaration the supervision of Professor Chris Pearce and Dr. Lukasz Kaczmarczyk in the De- partment of Civil Engineering

Singer, Jeremy

341

Influence of the partonic Pauli blocking on the hadronic final state in relativistic nucleus-nucleus collisions  

SciTech Connect

A simple transport model for ultra-relativistic nucleus-nucleus collisions is proposed to investigate the effect of Pauli blocking, in the transition from the hadron phase to parton phase, on the hadronic final state. A boost invariant study of the Pauli blocking is implemented in the Monte Carlo simulation for the first time. It turns out that this partonic Pauli effect on the final hadron multiplicity in a nucleus-nucleus collision is negligible at SPS energy, around two percent at RHIC energy, but reaching ten percent at LHC energy. The higher reaction energy the stronger is the partonic Pauli effect.

Sa Benhao [China Institute of Atomic Energy, P.O. Box 275 (18), Beijing, 102413 (China); Laboratorio Nazionale del Sud, Istituto Nazionale Di Fisica Nucleare, Via S. Sofia 44, I-95123 Catania (Italy); Institute of Theoretical Physics, Academy Sciences, Beijing, 100080 (China); Bonasera, A. [Laboratorio Nazionale del Sud, Istituto Nazionale Di Fisica Nucleare, Via S. Sofia 44, I-95123 Catania (Italy)

2004-09-01

342

Investigation of high p$_{t}$ events in Nucleus-Nucleus collisions using the Hijing event generator  

E-print Network

In recent years lot of interest has been observed in the nucleus-nucleus collisions at RHIC energies in phenomena related to high $p_{t}$ physics \\cite{ref1}. The suppression of high $p_{t}$ particles and disappearance of back-to-back jets compared to the scaling with number of binary nucleon-nucleon collisions indicates that a nearly perfect liquid is produced in these collisions. Results on self shadowing of high $p_{t}$ events are presented using hadron multiplicity associated to high $p_{t}$ and unbiased events in nucleus-nucleus collisions \\cite{ref2} obtained from the hijing event generator.

Natasha Sharma; Madan M. Aggarwal

2009-10-29

343

Retrotrapezoid nucleus, respiratory chemosensitivity and breathing automaticity  

PubMed Central

SUMMARY Breathing automaticity and CO2 regulation are inseparable neural processes. The retrotrapezoid nucleus (RTN), a group of glutamatergic neurons that express the transcription factor Phox2b, may be a crucial nodal point through which breathing automaticity is regulated to maintain CO2 constant. This review updates the analysis presented in prior publications. Additional evidence that RTN neurons have central respiratory chemoreceptor properties is presented but this is only one of many factors that determine their activity. The RTN is also regulated by powerful inputs from the carotid bodies and, at least in the adult, by many other synaptic inputs. We also analyze how RTN neurons may control the activity of the downstream central respiratory pattern generator. Specifically, we review the evidence which suggests that RTN neurons a) innervate the entire ventral respiratory column, and b) control both inspiration and expiration. Finally, we argue that the RTN neurons are the adult form of the parafacial respiratory group in neonate rats. PMID:19712903

Guyenet, Patrice G.; Bayliss, Douglas A.; Stornetta, Ruth L.; Fortuna, Michal G.; Abbott, Stephen B.; Depuy, Seth D.

2009-01-01

344

Retrotrapezoid nucleus, respiratory chemosensitivity and breathing automaticity.  

PubMed

Breathing automaticity and CO(2) regulation are inseparable neural processes. The retrotrapezoid nucleus (RTN), a group of glutamatergic neurons that express the transcription factor Phox2b, may be a crucial nodal point through which breathing automaticity is regulated to maintain CO(2) constant. This review updates the analysis presented in prior publications. Additional evidence that RTN neurons have central respiratory chemoreceptor properties is presented, but this is only one of many factors that determine their activity. The RTN is also regulated by powerful inputs from the carotid bodies and, at least in the adult, by many other synaptic inputs. We also analyze how RTN neurons may control the activity of the downstream central respiratory pattern generator. Specifically, we review the evidence which suggests that RTN neurons (a) innervate the entire ventral respiratory column and (b) control both inspiration and expiration. Finally, we argue that the RTN neurons are the adult form of the parafacial respiratory group in neonate rats. PMID:19712903

Guyenet, Patrice G; Bayliss, Douglas A; Stornetta, Ruth L; Fortuna, Michal G; Abbott, Stephen B G; DePuy, Seth D

2009-08-31

345

Nucleon-nucleus potentials by IP inversion  

NASA Astrophysics Data System (ADS)

The iterative-perturbative (IP) inversion algorithm makes it possible to determine, essentially uniquely, the complex potential, including spin-orbit component, for spin half particles given the elastic scattering S-matrix S ij. The same algorithm can be applied to fixed energy and, in certain cases, fixed partial wave inversion. Moreover, it can be applied to the intermediate "mixed case". We briefly define the classes of cases which can be studied, outline the IP method itself, and then review a wide range of applications of the method which have led to the extraction of information concerning nucleon-nucleus potentials. We then briefly list heavy ion applications. Reference is given to the code IMAGO which embodies the IP algorithm, and which can be applied to a very wide range of inversion situations for nucleons as well as spinless heavy ions, including identical bosons.

Mackintosh, R. S.; Cooper, S. G.

346

Parity violation in the compound nucleus  

SciTech Connect

Parity violation in the compound nucleus is reviewed as an example of a wider class of phenomena: The breaking of a discrete symmetry by a weak interaction in a stochastic or chaotic quantum system. Generically, enhancement factors amplify the signal for symmetry breaking, and the stochastic properties allow the strength of the symmetry-breaking interaction to be inferred from that signal without the need to know the wave functions of individual states. We describe recent experiments on parity violation that have been undertaken in this spirit. The scattering of spin-polarized neutrons by medium-weight and heavy nuclei provides signals for parity violation at the percent level. The statistical analysis of the data yields values for the spreading width around 10{sup {minus}6}eV, in keeping with theoretical expectations. We discuss open problems and possible future directions. {copyright} {ital 1999} {ital The American Physical Society}

Mitchell, G.E. [North Carolina State University, Raleigh, North Carolina, 27695-8202 (United States)] [North Carolina State University, Raleigh, North Carolina, 27695-8202 (United States); [Triangle Universities Nuclear Laboratory, Durham, North Carolina, 27708-0308 (United States); Bowman, J.D. [Los Alamos National Laboratory, Los Alamos, New Mexico, 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico, 87545 (United States); Weidenmueller, H.A. [Max Planck Institut fuer Kernphysik, Heidelberg (Germany)] [Max Planck Institut fuer Kernphysik, Heidelberg (Germany)

1999-01-01

347

Delta-nucleus dynamics: proceedings of symposium  

SciTech Connect

The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta ..delta..(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe ..delta..-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented. (WHK)

Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P. (eds.)

1983-10-01

348

Percutaneous laser discectomy: experience and long term follow-up.  

PubMed

The classical microsurgical approach in the treatment of herniated nucleus pulposus (HNP) has been substituted over the years by endoscopical approach, in which it is possible to practice via endoscopy a laser thermo-discoplasty, and by percutaneous laser disc decompression and nucleotomy. Percutaneous laser disc decompression and nucleotomy have been performed worldwide in more than 40,000 cases of HNP. Because water is the major component of the intervertebral disc and in HNP pain is caused by disc protrusion pressing against the nerve root, a 980 nm Diode (Biolitec AG-Germany) laser introduced via a 21-G needle under X-ray or CT-scan guidance and local anesthesia, vaporizes a small amount of the nucleous pulposus shrinking the disc and relieving the pressure on the nerve root. A multicentric retrospective study with a mean follow-up of 6 years was performed on 900 patients suffering from relevant symptoms that had been therapy-resistant for 6 months on average before consulting our department. Evaluation included 585 (65%) males and 315 (35%) females. The average age of patients operated was 46 years (18-54). The success rate at a mean follow-up of 5 years (2-6 years) was about 70% with a very low complication rate. PMID:21107947

Menchetti, P P M; Canero, G; Bini, W

2011-01-01

349

An unusual cause for epigastric pain in pregnancy. Spontaneous uterine rupture with herniation of the amniotic sac in a 33-week primigravida.  

PubMed

A 29-year-old in vitro fertilisation patient presented at 33 weeks of gestation with abdominal pain. An abdominal ultrasound revealed a cystic lesion adjacent to the fundus. During caesarean section, a defect at the fundus was identified with herniation of the amniotic sac through this defect. There were no complications postoperatively and the patient made an unremarkable recovery. With at least one maternal death reported in the most recent confidential enquiry into maternal death, uterine rupture is an obstetric emergency and can have catastrophic outcomes. The incidence of uterine rupture as a result of previous perforation is unclear with little published data and few case reports. Cases of uterine rupture after perforation following hysteroscopic resection of fibroids, uterine septum are well published but the authors found no known previous cases related to laparoscopy. Counselling patients post perforation should include discussion regarding the management of future pregnancies and the risk of uterine rupture. PMID:24599426

Al-Kufaishi, Asmaa; Erasmus, Kim; Carr, David; Owen, Elizabeth

2014-01-01

350

The Effects of Stretching with Lumbar Traction on VAS and Oswestry Scales of Patients with Lumbar 4–5 Herniated Intervertebral Disc  

PubMed Central

[Purpose] This study investigated the effect of stretching with lumbar traction on VAS and Oswestry scale scores of lumbar 4–5 herniated intervertebral disc (HIVD) patients. [Subjects] We recruited 20 lumbar 4–5 HIVD patients. [Methods] We performed stretching with lumbar traction for lumbar 4–5 HIVD patients during 4 weeks. The VAS and Oswestry scales were measured before and 4 weeks after the intervention. [Results] The results showed a significant decrease in VAS scale scores for stretching with lumbar traction in lumbar 4–5 HIVD patients, from 18±1.29 to 2.1±1.35. The Oswestry scale scores also decreased significantly, from 20.35±2.01 to 3.5±2.84, after stretching with lumbar traction. [Conclusion] Thus, we suggest stretching with lumbar traction for lumbar 4–5 HIVD patients. PMID:25140094

Yang, Hae-sun; Yoo, Won-gyu

2014-01-01

351

Parabrachial nucleus involvement in multiple system atrophy?  

PubMed Central

Multiple system atrophy (MSA) is associated with respiratory dysfunction, including sleep apnea, respiratory dysrhythmia, and laryngeal stridor. Neurons of the parabrachial nucleus (PBN) control respiratory rhythmogenesis and airway resistance. Objectives The objective of this study is to determine whether there was involvement of putative respiratory regions of the PBN in MSA. Methods We examined the pons at autopsy in 10 cases with neuropathologically confirmed MSA and 8 age-matched controls. Sections obtained throughout the pons were processed for calcitonin-gene related peptide (CGRP) and Nissl staining to identify the lateral crescent of the lateral PBN (LPB) and the Kölliker-Fuse nucleus (K-F), which are involved in respiratory control. Cell counts were performed using stereology. Results There was loss of CGRP neurons in the PBN in MSA (total estimated cell counts for the external LPB cluster was 12,584 ± 1146 in controls and 5917 ± 389 in MSA, p < 0.0001); for the external medial PBN (MPB) cluster it was 15,081 ± 1758 in controls and 7842 ± 466 in MSA, p < 0.001. There was also neuronal loss in putative respiratory regions of the PBN, including the lateral crescent of the LPB (13,039 ± 1326 in controls and 4164 ± 872 in MSA, p < 0.0001); and K-F (5120 ± 495 in controls and 999 ± 308 in MSA, p < 0.0001). Conclusions There is involvement of both CGRP and putative respiratory cell groups in the PBN in MSA. Whereas the clinical implications of CGRP cell loss are still undetermined, involvement of the LPB and K-F may contribute to respiratory dysfunction in this disorder. PMID:23665165

Benarroch, E.E.; Schmeichel, A.M.; Low, P.A.; Parisi, J.E.

2014-01-01

352

Minimally invasive surgery with spotlight work channel system in the treatment of lumbar disc herniation: a retrospective study of 21 cases.  

PubMed

A group of lumbar discherniation cases was treated with posterior discectomy and decompression with Spotlight working channel. We retrospectively studied these patients. To study and analyze the clinical efficacy and technical features of discectomy which is carried out with the Spotlight channel technology. The development of the minimally invasive spine surgery technology promotes new instruments and materials. For minimally invasive spine surgery in channel technology, the newly launched DepuySpine working channel-Spotlight, which is a new generation of wide viewing angle, single-hole device for minimally invasive spine operations, has good prospects for clinical application. From March 2011 to March 2012, 21 patients who were diagnosed with lumbar disc herniation were treated with posterior discectomy and decompression with Spotlight working channel, then the lumbar and leg pain visual analogue scale (VAS) scores of before and after surgery and that of the follow-ups and the Oswestry Disability Index were analyzed. All patients were successfully operated, and also they received follow-ups for more than 1 year. The postoperative lumbar and leg pain VAS scores improved significantly compared with the preoperative ones (P < 0.05) and can effectively maintain (P > 0.05). The three time points of lumbar pain VAS were 7.80 ± 0.49, 1.51 ± 0.52 and 1.47 ± 0.59. The leg pain VAS were 7.53 ± 0.50, 1.58 ± 0.58 and 1.49 ± 0.67. During the follow-ups of the cases in this group, no case of disc herniation relapsed. Patients were satisfied with that. The Spotlight channel system is one of the surgical approaches to "minimally invasive spine technology with direct vision". It has a good range of surgical indications. It can be carried out flexibly and used widely, which means it will be easier for the surgeons to master. PMID:25129385

Xu, Haidong; Jia, Fengyu; Liu, Yanbin; Fu, Qiang

2015-01-01

353

Nonmonotonic Target Excitation Dependence of Pion Clans in Relativistic Nucleus-Nucleus Collisions  

NASA Astrophysics Data System (ADS)

Target excitation dependence of fluctuation of produced pions (i.e. classifying data of the fluctuation pattern on pions on the basis of the number of gray tracks) is studied for nucleus-nucleus collisions at different projectile energies. In each set the experimental multiplicity distribution is compared with the negative binomial distribution (NBD), which is found to describe the experimental distribution quite well. Target excitation dependence is studied in respect of the clan model parameters bar {n}c and bar {N}, which are extracted from the NBD fit parameters bar {n} and k. A detailed comparison between different interactions at the same energy and the same interactions at different energies is also drawn. A nonmonotonic dependence of D2/bar {n} on is revealed, which is also a characteristic of multiplicity fluctuations at RHIC data.

Ghosh, Dipak; Deb, Argha; Dutta, Srimonti

354

On the geometric nature of high energy nucleus-nucleus reaction cross sections  

NASA Technical Reports Server (NTRS)

Within the context of a high energy double-folding optical potential approximation to the exact nucleus-nucleus multiple-scattering series, eikonal scattering theory is used to investigate the validity of geometric reaction cross sections in relativistic heavy ion collisions. The potential used includes a finite range interaction and nuclear single-particle densities extracted from nuclear charge distributions by unfolding the finite proton charge distribution. Pauli correlation effects are also included in an approximate way. The sensitivity of the predictions to the assumed interaction, Pauli correlation approximation, and nuclear density distributions is investigated. These results are in agreement with early predictions concerning the geometric nature of relativistic heavy ion collisions and in disagreement with a recent analysis, utilizing the zero range approximation, which suggested otherwise. Reasons for the lack of agreement between the analyses are also presented. Finally, approximate applicability limits for geometric reaction cross sections are determined.

Townsend, L. W.; Wilson, J. W.; Bidasaria, H. B.

1982-01-01

355

Fluctuation analysis of relativistic nucleus-nucleus collisions in emulsion chambers  

NASA Technical Reports Server (NTRS)

An analytical technique was developed for identifying enhanced fluctuations in the angular distributions of secondary particles produced from relativistic nucleus-nucleus collisions. The method is applied under the assumption that the masses of the produced particles are small compared to their linear momenta. The importance of particles rests in the fact that enhanced fluctuations in the rapidity distributions is considered to be an experimental signal for the creation of the quark-gluon-plasma (QGP), a state of nuclear matter predicted from the quantum chromodynamics theory (QCD). In the approach, Monte Carlo simulations are employed that make use of a portable random member generator that allow the calculations to be performed on a desk-top computer. The method is illustrated with data taken from high altitude emulsion exposures and is immediately applicable to similar data from accelerator-based emulsion exposures.

Mcguire, Stephen C.

1988-01-01

356

Cerebellar interposed nucleus lesions suppress lymphocyte function in rats  

Microsoft Academic Search

We previously reported that the cerebellar fastigial nucleus, output nucleus of the spinocerebellum, modulates lymphocyte function. To further explore the role of the cerebellum in neuroimmunomodulation, we here lesioned bilaterally the cerebellar interposed nuclei (IN) of rats with kainic acid (KA) injections. On days 8, 16 and 32 after IN lesions, lymphocyte percentage in peripheral white blood cells was examined.

Yu-Ping Peng; Yi-Hua Qiu; Jian Qiu; Jian-Jun Wang

2006-01-01

357

COMMUNICATION Are Residues in a Protein Folding Nucleus  

E-print Network

COMMUNICATION Are Residues in a Protein Folding Nucleus Evolutionarily Conserved? Yan Yuan Tseng is the hallmark of life. It is important to understand how protein folding and evolution influence each other in protein folding nucleus as measured by experi- mental f-value and selection pressure as measured by v

Dai, Yang

358

The Confined Hydrogen Atom with a Moving Nucleus  

ERIC Educational Resources Information Center

We study the hydrogen atom confined to a spherical box with impenetrable walls but, unlike earlier pedagogical articles on the subject, we assume that the nucleus also moves. We obtain the ground-state energy approximately by means of first-order perturbation theory and show that it is greater than that for the case in which the nucleus is clamped…

Fernandez, Francisco M.

2010-01-01

359

GABA and glycine immunolabeling in the chicken tangential nucleus  

Microsoft Academic Search

In the vestibular nuclei, GABAergic and glycinergic neurons play important roles in signal processing for normal function, during development, and after peripheral vestibular lesions. The chicken tangential nucleus is a major avian vestibular nucleus, whose principal cells are projection neurons with axons transmitting signals to the oculomotor nuclei and\\/or cervical spinal cord. Antibodies against GABA, glycine and glutamate were applied

A. Popratiloff; K. D. Peusner

2011-01-01

360

Nucleon emission via electromagnetic excitation in relativistic nucleus-nucleus collisions: Reanalysis of the Weizsaecker-Williams method  

SciTech Connect

Previous analyses of the comparison of Weizsaecker-Williams theory to experiment for nucleon emission via electromagnetic excitations in nucleus-nucleus collisions have not been definitive because of different assumptions concerning the value of the minimum impact parameter. This situation is corrected by providing criteria that allow one to make definitive statements concerning agreement or disagreement between Weizsaescker-Williams theory and experiment.

Norbury, J.W. (Department of Physics, Rider College, Lawrenceville, New Jersey 08648 (US))

1989-12-01

361

Nucleon emission via electromagnetic excitation in relativistic nucleus-nucleus collisions: Re-analysis of the Weizsacker-Williams method  

NASA Technical Reports Server (NTRS)

Previous analyses of the comparison of Weizsacker-Williams (WW) theory to experiment for nucleon emission via electromagnetic (EM) excitations in nucleus-nucleus collisions were not definitive because of different assumptions concerning the value of the minimum impact parameter. This situation is corrected by providing criteria that allows definitive statements to be made concerning agreement or disagreement between WW theory and experiment.

Norbury, John W.

1989-01-01

362

Improved Partial Cross Section Calculations of Nucleus-Nucleus Reactions, for Cosmic-Ray Propagation in Materials  

NASA Astrophysics Data System (ADS)

The S-T semiempirical proton-nucleus cross section calculations have recently been improved(Silberberg R., Tsao C.H. and Barghouty A.F., to be published in "Towards the Millennium in Astrophysics" by the World Scientific Publication Co., Singapore, 1997) based on measurements of several groups. These are now being extended to nucleus-nucleus reactions, using scaling, supplemented by empirical factors. We have improved the charge-pick cross sections based on the work of Nilsen et al. (Nilsen B.S. et al. (1994), Phys. Rev. C50, 1065) We are also exploring the electromagnetic dissociation calculations by Norbury and Townsend(Norbury J.W. and Townsend L.W. (1993), Ap. J. Suppl. 86, 307), which have large cross sections for the removal of a few nucleons in heavy nucleus - heavy nucleus collisions.

Tsao, C. H.; Silberberg, R.; Barghouty, A. F.

1997-04-01

363

Inputs to the ventrolateral bed nucleus of the stria terminalis.  

PubMed

The ventrolateral bed nucleus of the stria terminalis (BSTvl) receives direct input from two specific subpopulations of neurons in the nucleus tractus solitarius (NTS). It is heavily innervated by aldosterone-sensitive NTS neurons, which are selectively activated by sodium depletion, and by the A2 noradrenergic neurons, which are activated by visceral and immune- and stress-related stimuli. Here, we used a retrograde neuronal tracer to identify other brain sites that innervate the BSTvl. Five general brain regions contained retrogradely labeled neurons: cerebral cortex (infralimbic and insular regions), rostral forebrain structures (subfornical organ, organum vasculosum of the lamina terminalis, taenia tecta, nucleus accumbens, lateral septum, endopiriform nucleus, dorsal BST, substantia innominata, and, most prominently the amygdala--primarily its basomedial and central subnuclei), thalamus (central medial, intermediodorsal, reuniens, and, most prominently the paraventricular thalamic nucleus), hypothalamus (medial preoptic area, perifornical, arcuate, dorsomedial, parasubthalamic, and posterior hypothalamic nuclei), and brainstem (periaqueductal gray matter, dorsal and central superior raphe nuclei, parabrachial nucleus, pre-locus coeruleus region, NTS, and A1 noradrenergic neurons in the caudal ventrolateral medulla). In the arcuate hypothalamic nucleus, some retrogradely labeled neurons contained either agouti-related peptide or cocaine/amphetamine-regulated transcript. Of the numerous retrogradely labeled neurons in the perifornical hypothalamic area, few contained melanin-concentrating hormone or orexin. In the brainstem, many retrogradely labeled neurons were either serotoninergic or catecholaminergic. In summary, the BSTvl receives inputs from a variety of brain sites implicated in hunger, salt and water intake, stress, arousal, and reward. PMID:18853414

Shin, Jung-Won; Geerling, Joel C; Loewy, Arthur D

2008-12-10

364

Ultrasonic evoked responses in rat cochlear nucleus  

PubMed Central

Numerous studies have reported auditory brainstem responses evoked by stimuli within the “normal” hearing range of rats, with maximum sensitivity peaking around 16 kHz. Yet rats also emit and respond to sounds in the ultrasonic (US) frequency range (30-100 kHz). However very few electrophysiological studies have recorded auditory brainstem responses using US stimuli, and none have exceeded 70 kHz. We report here short-latency (1-3 ms) evoked potentials recorded in rat cochlear nucleus (CN) to US stimuli ranging from 40-90 kHz. Robust responses were recorded in 33 of 36 CN recording sites to stimuli ranging from 40-60 kHz; and twenty-eight of these sites continued to yield well defined responses out to 90 kHz. Latencies systematically increased and overall amplitudes decreased with increasing US frequency. Amplitudes differed significantly in the three CN subnuclei, being largest in posterior-ventral (PVCN) and smallest in anterior-ventral (AVCN). The fact that well defined responses can be recorded to stimuli as high as 90 kHz significantly extends the recorded upper frequency range of neural activity in the brainstem auditory pathway of the rat. These evoked potential results agree with the well documented behavioral repertoire of rats in the US frequency range. PMID:17803975

Du, Yi; Ping, Junli; Li, Nanxin; Wu, Xihong; Li, Liang; Galbraith, Gary

2009-01-01

365

Comparing Realistic Subthalamic Nucleus Neuron Models  

NASA Astrophysics Data System (ADS)

The mechanism of action of clinically effective electrical high frequency stimulation is still under debate. However, recent evidence points at the specific activation of GABA-ergic ion channels. Using a computational approach, we analyze temporal properties of the spike trains emitted by biologically realistic neurons of the subthalamic nucleus (STN) as a function of GABA-ergic synaptic input conductances. Our contribution is based on a model proposed by Rubin and Terman and exhibits a wide variety of different firing patterns, silent, low spiking, moderate spiking and intense spiking activity. We observed that most of the cells in our network turn to silent mode when we increase the GABAA input conductance above the threshold of 3.75 mS/cm2. On the other hand, insignificant changes in firing activity are observed when the input conductance is low or close to zero. We thus reproduce Rubin's model with vanishing synaptic conductances. To quantitatively compare spike trains from the original model with the modified model at different conductance levels, we apply four different (dis)similarity measures between them. We observe that Mahalanobis distance, Victor-Purpura metric, and Interspike Interval distribution are sensitive to different firing regimes, whereas Mutual Information seems undiscriminative for these functional changes.

Njap, Felix; Claussen, Jens C.; Moser, Andreas; Hofmann, Ulrich G.

2011-06-01

366

Energy levels of the nucleus 166Ho  

NASA Astrophysics Data System (ADS)

The complete low energy two-particle spectrum arising from the coupling of the single-particle orbitals with summed energy (Ep+En) up to 750 keV, and from the coupling of all known proton orbitals up to 1.5 MeV with the ground state neutron, is calculated for the doubly odd deformed nucleus 166Ho. The bandhead energies, the Gallagher-Moszkowski splitting energies, and the nuclear moment of inertia parameters for deriving the rotational energies are calculated for a zero range residual interaction for each of the 34 possible bands for comparison with the available experimental results from radioactive decay, neutron capture, and particle transfer reaction studies wherein 21 bands have been postulated. Our calculations agree with the characterization of 11 of these bands. We further present evidence for selecting specific K? and/or configurations for the remaining 10 bands. Predicted location and character of 13 bands not observed so far are given. Identification of 3 of these bands with known levels is proposed.

Sood, P. C.; Sheline, R. K.; Ray, R. S.

1987-05-01

367

Pedunculopontine nucleus: functional organization and clinical implications.  

PubMed

The pedunculopontine tegmental nucleus (PPN) is a neurochemically and functionally heterogeneous structure that occupies a strategic position in the dorsal tegmentum of the midbrain and upper pons. The PPN contains cholinergic, ?-aminobutyric acid (GABA)ergic, and glutamatergic neurons; it receives direct input from the cerebral cortex, is reciprocally connected with the basal ganglia, and provides inputs to the thalamus and motor areas of the brainstem and spinal cord. Via these connections, the PPN is involved in mechanisms of cortical arousal and behavioral state control and participates in control of locomotion and muscle tone. The PPN is affected in Parkinson disease (PD) and atypical parkinsonian syndromes such as progressive supranuclear palsy (PSP) and multiple system atrophy (MSA). Involvement of the PPN may have an important role in gait impairment in these disorders. The development of PPN deep brain stimulation (DBS) for treatment of this disabling symptom has also provided some insight into the function of the PPN in humans. There have been several recent reviews on the PPN focused on its neurochemical organization and connectivity, physiology, involvement in parkinsonian syndromes, and as a target for DBS.(1-12.) PMID:23509047

Benarroch, Eduardo E

2013-03-19

368

Retrotrapezoid nucleus and parafacial respiratory group  

PubMed Central

The rat retrotrapezoid nucleus (RTN) contains about 2000 Phox2b-expressing glutamatergic neurons (ccRTN neurons; 800 in mice) with a well-understood developmental lineage. ccRTN neuron development fails in mice carrying a Phox2b mutation commonly present in the congenital central hypoventilation syndrome. In adulthood, ccRTN neurons regulate the breathing rate and intensity, and may regulate active expiration along with other neighboring respiratory neurons. Prenatally, ccRTN neurons form an autonomous oscillator (embryonic parafacial group, e-pF) that activates and possibly paces inspiration. The pacemaker properties of the ccRTN neurons probably vanish after birth to be replaced by synaptic drives. The neonatal parafacial respiratory group (pfRG) may represent a transitional phase during which ccRTN neurons lose their group pacemaker properties. ccRTN neurons are activated by acidification via an intrinsic mechanism or via ATP released by glia. In summary, throughout life, ccRTN neurons seem to be a critical hub for the regulation of CO2 via breathing. PMID:20188865

Guyenet, Patrice G.; Mulkey, Daniel K.

2010-01-01

369

Determination of electron-nucleus collision geometry with forward neutrons  

E-print Network

There are a large number of physics programs one can explore in electron-nucleus collisions at a future electron-ion collider. Collision geometry is very important in these studies, while the measurement for an event-by-event geometric control is rarely discussed in the prior deep inelastic scattering experiments off a nucleus. This paper seeks to provide some detailed studies on the potential of tagging collision geometries through forward neutron multiplicity measurements with a zero degree calorimeter. This type of geometry handle, if achieved, can be extremely beneficial in constraining nuclear effects for the electron-nucleus program at an electron-ion collider.

L. Zheng; E. C. Aschenauer; J. H. Lee

2014-07-30

370

Observation of the antimatter helium-4 nucleus  

SciTech Connect

High-energy nuclear collisions create an energy density similar to that of the Universe microseconds after the Big Bang; in both cases, matter and antimatter are formed with comparable abundance. However, the relatively short-lived expansion in nuclear collisions allows antimatter to decouple quickly from matter, and avoid annihilation. Thus, a high-energy accelerator of heavy nuclei provides an efficient means of producing and studying antimatter. The antimatter helium-4 nucleus ({sup 4}He), also known as the anti-{alpha} ({alpha}), consists of two antiprotons and two antineutrons (baryon number B = -4). It has not been observed previously, although the {alpha}-particle was identified a century ago by Rutherford and is present in cosmic radiation at the ten per cent level. Antimatter nuclei with B < -1 have been observed only as rare products of interactions at particle accelerators, where the rate of antinucleus production in high-energy collisions decreases by a factor of about 1,000 with each additional antinucleon. Here we report the observation of {sup 4}He, the heaviest observed antinucleus to date. In total, 18 {sup 4}He counts were detected at the STAR experiment at the Relativistic Heavy Ion Collider (RHIC) in 10{sup 9} recorded gold-on-gold (Au+Au) collisions at centre-of-mass energies of 200 GeV and 62 GeV per nucleon-nucleon pair. The yield is consistent with expectations from thermodynamic and coalescent nucleosynthesis models, providing an indication of the production rate of even heavier antimatter nuclei and a benchmark for possible future observations of {sup 4}He in cosmic radiation.

Agakishiev, H.; Tang, A.; et al. (STAR Collaboration)

2011-04-24

371

Observation of the antimatter helium-4 nucleus.  

PubMed

High-energy nuclear collisions create an energy density similar to that of the Universe microseconds after the Big Bang; in both cases, matter and antimatter are formed with comparable abundance. However, the relatively short-lived expansion in nuclear collisions allows antimatter to decouple quickly from matter, and avoid annihilation. Thus, a high-energy accelerator of heavy nuclei provides an efficient means of producing and studying antimatter. The antimatter helium-4 nucleus (4He), also known as the anti-? (?), consists of two antiprotons and two antineutrons (baryon number B = -4). It has not been observed previously, although the ?-particle was identified a century ago by Rutherford and is present in cosmic radiation at the ten per cent level. Antimatter nuclei with B?

2011-05-19

372

2D model of the Nucleus  

NASA Astrophysics Data System (ADS)

The CBM (model) of the nucleus has resulted in the prediction of two new quarks, an "up" quark of mass 237.31 MeV/c2 and a "dn" quark of mass 42.392 MeV/c2. These two new predicted quarks helped to determine that the masses of the quarks and leptons are all related by a geometric progression relationship. The mass of each quark or lepton is just the "geometric mean" of two related elementary particles, either in the same generation or in the same family. This numerology predicts the following masses for the electron family: 0.511000 (electron), 7.74 (predicted), 117.3, 1778.4 (tau), 26950.1 MeV. The geometric ratio of this progression is 15.154 (e to the power e). The mass of the tau in this theory agrees very well with accepted values. This theory suggests that all the "dn like" quarks have a mass of just 10X multiples of 4.24 MeV (the mass of the "d" quark). The first 3 "up like" quark masses are 38, 237.31 and 1500 MeV. This theory also predicts a new heavy generation with a lepton mass of 27 GeV, a "dn like" quark of 42.4 GeV, and an "up like" quark of 65 GeV. Significant evidence already exists for the existence of these new quarks, and lepton. Ref. Masses of the Sub-Nuclear Particles, nucl-th/ 0008026, @ http://xxx.lanl.gov. Infinite Energy, Vol 5, issue 30.

Lach, Theodore M.

2003-10-01

373

Glutamate Inputs to the Nucleus Accumbens: Does Source Matter?  

E-print Network

How the nucleus accumbens integrates information from multiple upstream regions has been a central question for decades. In this issue of Neuron, Britt et al. (2012) photostimulate glutamatergic axons from the amygdala, ...

Tye, Kay

374

Cloud condensation nucleus-sulfate mass relationship and cloud albedo  

NASA Technical Reports Server (NTRS)

Analysis of previously published, simultaneous measurements of cloud condensation nucleus number concentration and sulfate mass concentration suggest a nonlinear relationship between the two variables. This nonlinearity reduces the sensitivity of cloud albedo to changes in the sulfur cycle.

Hegg, Dean A.

1994-01-01

375

Comparison of active regions on the nucleus of Comet Halley  

NASA Technical Reports Server (NTRS)

The images of the nucleus of Comet Halley returned by the Giotto spacecraft reveal a number of active regions on the surface, one of which is near the expected location of the rotation axis. This feature is larger and brighter than other source regions, suggesting that the mechanism which drives this source is also different. At this active region near the rotation pole the Sun is circumpolar for a significant portion of the solar encounter. Continuous solar insolation causes heating of the nucleus to greater depths and results in the unique properties of this source region. For example, the dust scattering in the antisolar regions around the nucleus is less from the polar region than from the region at the sunward end of the nucleus, consistent with spotty ejection of dusty mantle from the sunward tip and widespread activity in the polar region.

Reitsema, H. J.; Delamere, W. A.; Whipple, F. L.

1987-01-01

376

Cytotoxicity of nucleus-targeting fluorescent gold nanoclusters  

NASA Astrophysics Data System (ADS)

Gold nanoclusters (AuNCs) with ultra small sizes and unique fluorescence properties have shown promising potential for imaging the nuclei of living cells. However, little is known regarding the potential cytotoxicity of AuNCs after they enter the cell nucleus. The aim of this study is to investigate whether and how nucleus-targeting AuNCs affect the normal functioning of cells. Highly stable, water-soluble and bright fluorescent Au25NCs (the core of each nanocluster is composed of 25 gold atoms) were synthesized. Specific targeting of Au25NCs to the cell nucleus was achieved by conjugating the TAT peptide to the Au25NCs. Cell viability, cell morphology, cell apoptosis/necrosis, reactive oxygen species (ROS) level and mitochondrial membrane potential examinations were performed on different cell lines exposed to the nucleus-targeting Au25NCs. We found that the nucleus-targeting Au25NCs caused cell apoptosis in a dose-dependent manner. A possible mechanism for the cytotoxicity of the nucleus-targeting Au25NCs was proposed as follows: the nucleus-targeting Au25NCs induce the production of ROS, resulting in the oxidative degradation of mitochondrial components, in turn leading to apoptosis via a mitochondrial damage pathway. This work facilitates a better understanding of the toxicity of AuNCs, especially nucleus-targeting AuNCs.Gold nanoclusters (AuNCs) with ultra small sizes and unique fluorescence properties have shown promising potential for imaging the nuclei of living cells. However, little is known regarding the potential cytotoxicity of AuNCs after they enter the cell nucleus. The aim of this study is to investigate whether and how nucleus-targeting AuNCs affect the normal functioning of cells. Highly stable, water-soluble and bright fluorescent Au25NCs (the core of each nanocluster is composed of 25 gold atoms) were synthesized. Specific targeting of Au25NCs to the cell nucleus was achieved by conjugating the TAT peptide to the Au25NCs. Cell viability, cell morphology, cell apoptosis/necrosis, reactive oxygen species (ROS) level and mitochondrial membrane potential examinations were performed on different cell lines exposed to the nucleus-targeting Au25NCs. We found that the nucleus-targeting Au25NCs caused cell apoptosis in a dose-dependent manner. A possible mechanism for the cytotoxicity of the nucleus-targeting Au25NCs was proposed as follows: the nucleus-targeting Au25NCs induce the production of ROS, resulting in the oxidative degradation of mitochondrial components, in turn leading to apoptosis via a mitochondrial damage pathway. This work facilitates a better understanding of the toxicity of AuNCs, especially nucleus-targeting AuNCs. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr04227a

Zhao, Jing-Ya; Cui, Ran; Zhang, Zhi-Ling; Zhang, Mingxi; Xie, Zhi-Xiong; Pang, Dai-Wen

2014-10-01

377

Semi-inclusive charged-current neutrino-nucleus reactions  

E-print Network

The general, universal formalism for semi-inclusive charged-current (anti)neutrino-nucleus reactions is given for studies of any hadronic system, namely, either nuclei or the nucleon itself. The detailed developments are ...

Van Orden, J.?W.

378

PLANT SCIENCE: Nibbling at the Plant Cell Nucleus  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. When plants recognize certain pathogens, an activated immune receptor moves to the nucleus where it affects transcription to initiate a successful response.

Jeffery L. Dangl (University of North Carolina;Department of Biology, the Curriculum in Genetics, and the Carolina Center for Genome Sciences)

2007-02-23

379

Deconvolving the Nucleus of Centaurus A Using Chandra PSF Library  

NASA Technical Reports Server (NTRS)

Centaurus A (NGC 5128) is a giant early-type galaxy containing the nearest (at 3.5 Mpc) radio-bright Active Galactic Nucleus (AGN). Cen A was observed with the High Resolution Camera (HRC) on the Chandra X-ray Observatory on several occasions since the launch in July 1999. The high-angular resolution (less than 0.5 arcsecond) Chandra/HRC images reveal X ray multi-scale structures in this object with unprecedented detail and clarity, including the bright nucleus believed to be associated with a supermassive black hole. We explored the spatial extent of the Cen A nucleus using deconvolution techniques on the full resolution Chandra images. Model point spread functions (PSFs) were derived from the standard Chandra raytrace PSF library as well as unresolved point sources observed with Chandra. The deconvolved images show that the Cen A nucleus is resolved and asymmetric. We discuss several possible causes of this extended emission and of the asymmetries.

Karovska, Margarita

2000-01-01

380

Nucleus management in manual small incision cataract surgery by phacosection  

PubMed Central

Nucleus management is critical in manual small incision cataract surgery (MSICS), as the integrity of the tunnel, endothelium and posterior capsule needs to be respected. Several techniques of nucleus management are in vogue, depending upon the specific technique of MSICS. Nucleus can be removed in toto or bisected or trisected into smaller segments. The pressure in the eye can be maintained at the desired level with the use of an anterior chamber maintainer or kept at atmospheric levels. In MSICS, unlike phacoemulsification, there is no need to limit the size of the tunnel or restrain the size of capsulorrhexis. Large well-structured tunnels and larger capsulorrhexis provide better control on the surgical maneuvers. Safety and simplicity of MSICS has made it extremely popular. The purpose of this article is to describe nucleus management by phacosection in MSICS. PMID:19075409

Ravindra, M S

2009-01-01

381

Statistical analysis of secondary particle distributions in relativistic nucleus-nucleus collisions  

NASA Technical Reports Server (NTRS)

The use is described of several statistical techniques to characterize structure in the angular distributions of secondary particles from nucleus-nucleus collisions in the energy range 24 to 61 GeV/nucleon. The objective of this work was to determine whether there are correlations between emitted particle intensity and angle that may be used to support the existence of the quark gluon plasma. The techniques include chi-square null hypothesis tests, the method of discrete Fourier transform analysis, and fluctuation analysis. We have also used the method of composite unit vectors to test for azimuthal asymmetry in a data set of 63 JACEE-3 events. Each method is presented in a manner that provides the reader with some practical detail regarding its application. Of those events with relatively high statistics, Fe approaches 0 at 55 GeV/nucleon was found to possess an azimuthal distribution with a highly non-random structure. No evidence of non-statistical fluctuations was found in the pseudo-rapidity distributions of the events studied. It is seen that the most effective application of these methods relies upon the availability of many events or single events that possess very high multiplicities.

Mcguire, Stephen C.

1987-01-01

382

GABA and glutamate mediate rapid neurotransmission from suprachiasmatic nucleus to hypothalamic paraventricular nucleus in rat.  

PubMed Central

1. Intracellular sharp electrode and whole-cell patch-clamp recording from characterized paraventricular nucleus (PVN) neurones in rat hypothalamic slices were used to study the synaptic mechanism and associated neurotransmitters that mediate their response to suprachiasmatic nucleus (SCN) stimulation. 2. Electrical stimulation restricted to SCN evoked short-latency inhibitory postsynaptic potentials (IPSPs) or combinations of IPSPs and excitatory postsynaptic potentials (EPSPs) in all (n = 59) PVN neurones tested. Type I neurones (n = 18) were magnocellular and a majority (13/18) demonstrated monosynaptic IPSPs that reversed polarity at the chloride equilibrium potential and were sensitive to bicuculline. 3. Type II (n = 10) and III parvocellular (n = 13), and unclassifiable neurones (n = 18) displayed combinations of IPSPs and EPSPs following similar stimuli applied to SCN. IPSP blockade with bicuculline uncovered SCN-evoked monosynaptic dual-component EPSPs that were sensitive to N-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonists. In addition, chemical microstimulation within SCN was associated with transient increases in spontaneous EPSPs recorded from these PVN neurones. 4. These data imply that the amino acids GABA and glutamate are important mediators of fast monosynaptic transmission from SCN to defined neurones in PVN, and are candidates for conveying circadian rhythmicity to PVN regulation of neuroendocrine and autonomic processes. PMID:8930841

Hermes, M L; Coderre, E M; Buijs, R M; Renaud, L P

1996-01-01

383

Negative binomial distribution for hadron-nucleus interactions  

NASA Astrophysics Data System (ADS)

Assuming the validity of the negative binomial distribution for hadron-nucleus interactions, the Singh-Uddin-Kamal relation between the two parameters k Aandn¯s of the distribution is derived and is found to be universally valid for proton-proton as well as proton-nucleus interactions at high energy. We further deduce the target-mass number dependence and the energy dependence of the parameter kA.

Singh, C. P.; Shyam, M.; Uddin, Saeed

1991-01-01

384

Surgical versus Non-Operative Treatment for Lumbar Disc Herniation: Eight-Year Results for the Spine Patient Outcomes Research Trial (SPORT)  

PubMed Central

Study Design Concurrent prospective randomized and observational cohort studies. Objective To assess the 8-year outcomes of surgery vs. non-operative care. Summary of Background Data Although randomized trials have demonstrated small short-term differences in favor of surgery, long-term outcomes comparing surgical to non-operative treatment remain controversial. Methods Surgical candidates with imaging-confirmed lumbar intervertebral disc herniation meeting SPORT eligibility criteria enrolled into prospective randomized (501 participants) and observational cohorts (743 participants) at 13 spine clinics in 11 US states. Interventions were standard open discectomy versus usual non-operative care. Main outcome measures were changes from baseline in the SF-36 Bodily Pain (BP) and Physical Function (PF) scales and the modified Oswestry Disability Index (ODI - AAOS/Modems version) assessed at 6 weeks, 3 and 6 months, and annually thereafter. Results Advantages were seen for surgery in intent-to-treat analyses for the randomized cohort for all primary and secondary outcomes other than work status; however, with extensive non-adherence to treatment assignment (49% patients assigned to non-operative therapy receiving surgery versus 60% of patients assigned to surgery) these observed effects were relatively small and not statistically significant for primary outcomes (BP, PF, ODI). Importantly, the overall comparison of secondary outcomes was significantly greater with surgery in the intent-to-treat analysis (sciatica bothersomeness [p > 0.005], satisfaction with symptoms [p > 0.013], and self-rated improvement [p > 0.013]) in long-term follow-up. An as-treated analysis showed clinically meaningful surgical treatment effects for primary outcome measures (mean change Surgery vs. Non-operative; treatment effect; 95% CI): BP (45.3 vs. 34.4; 10.9; 7.7 to 14); PF (42.2 vs. 31.5; 10.6; 7.7 to 13.5) and ODI (?36.2 vs. ?24.8; ?11.2; ?13.6 to ?9.1). Conclusion Carefully selected patients who underwent surgery for a lumbar disc herniation achieved greater improvement than non-operatively treated patients; there was little to no degradation of outcomes in either group (operative and non-operative) from 4 to 8 years. PMID:24153171

Lurie, Jon D.; Tosteson, Tor D.; Tosteson, Anna N. A.; Zhao, Wenyan; Morgan, Tamara S.; Abdu, William A.; Herkowitz, Harry; Weinstein, James N.

2014-01-01

385

Clinical application of a novel clinical scale for the pre-operative risk evaluation of cerebral herniation from traumatic epidural hematoma.  

PubMed

Secondary massive cerebral infarction (MCI), the predominant prognostic factor of cerebral herniation from epidural hematoma (EDH), determines a need for decompressive craniectomy. However, few predictive indices have focused on it. In this study, we tested the clinical feasibility and reliability of a novel pre-operative risk scoring system (EDH-MCI scale) in the guidance of surgical decision-making. The scale is comprised of 6 risk factors, including location and volume of hematoma, duration and extent of preoperative cerebral herniation, Glasgow Coma Scale score, and presence of preoperative shock, with a total score ranging from 0 to 18 points. Results suggest that the accuracy of the surgical modality adapted for initial hematoma-evacuation surgery of 65 patients whose surgical modality were guided by the EDH-MCI scale (prospective cohort, 2012.02-2014.01) were significantly improved (95.38% vs. 77.95%, P=0.002) compared with those of an independent set of 126 patients (retrospective cohort, 2007.01-2012.01) whose surgical modalities were decided empirically. The EDH-MCI scale exhibited a satisfactory predictive capacity for the development of secondary MCI and discriminative performance for patients who were at high risk and thus required radical surgical treatments. It is suggested that simple hematoma-evacuation craniotomy was sufficient for patients with low risk scores (<=9 points), whereas decompressive craniectomy in combination with duraplasty were necessary for those with high risk scores (>=13 points). In patients with borderline risk scores (10-12 points), those having one or more of unstable vital signs, coexistence of severe secondary brainstem injury, and irresponsiveness of dilated pupils to emergent burr-hole hematoma-drainage had a significantly increased incidence of posttraumatic MCI, which underlined a high priority for radical surgical treatments. In conclusion, this novel pre-operative risk evaluation scale is easy to use and has a satisfactory predictive capacity forthe development of secondary MCI, thereby providing an objective reference for surgical-decision making and postoperative medical care. PMID:25393339

Lin, Hong; Wang, Wen-Hao; Hu, Lianshui; Li, Jun; Luo, Fei; Lin, Junming; Huang, Wei; Zhang, Ming-Sheng; Zhang, Yuan; Hu, Kang; Zheng, Jian-Xian

2014-11-13

386

A FIBER APPARATUS IN THE NUCLEUS OF THE YEAST CELL  

PubMed Central

The structure and mode of division of the nucleus of budding yeast cells have been studied by phase-contrast microscopy during life and by ordinary microscopy after Helly fixation. The components of the nucleus were differentially stained by the Feulgen procedure, with Giemsa solution after hydrolysis, and with iron alum haematoxylin. New information was obtained in cells fixed in Helly's by directly staining them with 0.005% acid fuchsin in 1% acetic acid in water. Electron micrographs have been made of sections of cells that were first fixed with 3% glutaraldehyde, then divested of their walls with snail juice, and postfixed with osmium tetroxide. Light and electron microscopy have given concordant information about the organization of the yeast nucleus. A peripheral segment of the nucleus is occupied by relatively dense matter (the "peripheral cluster" of Mundkur) which is Feulgen negative. The greater part of the nucleus is filled with fine-grained Feulgen-positive matter of low density in which chromosomes could not be identified. Chromosomes become visible in this region under the light microscope at meiosis. In the chromatin lies a short fiber with strong affinity for acid fuchsin. The nucleus divides by elongation and constriction, and during this process the fiber becomes long and thin. Electron microscopy has resolved it into a bundle of dark-edged 150 to 180 A filaments which extends between "centriolar plaques" that are attached to the nuclear envelope. PMID:5331666

Robinow, C. F.; Marak, J.

1966-01-01

387

Effect of microgravity on the biomechanical properties of lumbar and caudal intervertebral discs in mice.  

PubMed

Prolonged exposure to microgravity has shown to have deleterious effects on the human spine, indicated by low back pain during spaceflight and increased incidence of post-spaceflight herniated nucleus pulposus. We examined the effect of microgravity on biomechanical properties of lumbar and caudal discs from mice having been on 15-day shuttle mission STS-131. Sixteen C57BL/C mice (spaceflight group, n=8; ground-based control group, n=8) were sacrificed immediately after spaceflight. Physiological disc height (PDH) was measured in situ, and compressive creep tests were performed to parameterize biomechanical properties into endplate permeability (k), nuclear swelling pressure strain dependence (D), and annular viscoelasticity (G). For caudal discs, the spaceflight group exhibited 32% lower PDH, 70% lower D and crept more compared to the control mice (p=0.03). For lumbar discs, neither PDH nor D was significantly different between murine groups. Initial modulus, osmotic pressure, k and G for lumbar and caudal discs did not appear influenced by microgravity (p>0.05). Decreases in both PDH and D suggest prolonged microgravity effectively diminished biomechanical properties of caudal discs. By contrast, differences were not noted for lumbar discs. This potentially deleterious interaction between prolonged weightlessness and differential ranges of motion along the spine may underlie the increased cervical versus lumbar disc herniation rates observed among astronauts. PMID:25085756

Bailey, Jeannie F; Hargens, Alan R; Cheng, Kevin K; Lotz, Jeffrey C

2014-09-22

388

[Surgery of lumbar disk hernia: historical perspective].  

PubMed

Although the clinical picture of discogenic sciatica is well known already in the ancient world, it is not until 1933 that WJ Mixter and JS Barr provide the correct pathogenetic interpretation and suggest surgery as the treatment of choice. The work of the American Authors was however based on the knowledge acquired during the previous centuries starting with Domenico Cotugno, who first suggested the neurogenic nature of sciatica (1764) and later with the neurologists of the french school Valleix, Lasègue, Dejerine, Sicard who elucidated the semeiology and debated in detail the etiopathogenesis of the condition. The german pathologists Schmorl and Andrae (1927-29) are to be credited for their contribution to the pathology of intervertebral disc, recognizing the frequency and degenerative (not neoplastic) nature of nucleus pulposus herniation. Surgery of disc herniation starts with Oppenheim and Krause (1909). Mixter and Barr used laminectomy and a transdural route although a more limited approach to the spinal canal had already been proposed by the italian Bonomo (1902), unknown to many. Love, of the Mayo Clinic (1937-39) introduced the extradural/interlaminar approach while Caspar and Yasargil (1977) applied the concepts of microsurgery to the procedure. The latest advances are represented by percutaneous and endoscopic techniques. PMID:9835099

Brunori, A; De Caro, G M; Giuffrè, R

1998-01-01

389

Vertebral morphology influences the development of Schmorl's nodes in the lower thoracic vertebrae.  

PubMed

Schmorl's nodes are the result of herniations of the nucleus pulposus into the adjacent vertebral body and are commonly identified in both clinical and archaeological contexts. The current study aims to identify aspects of vertebral shape that correlate with Schmorl's nodes. Two-dimensional statistical shape analysis was performed on digital images of the lower thoracic spine (T10-T12) of adult skeletons from the late medieval skeletal assemblages from Fishergate House, York, St. Mary Graces and East Smithfield Black Death cemeteries, London, and postmedieval Chelsea Old Church, London. Schmorl's nodes were scored on the basis of their location, depth, and size. Results indicate that there is a correlation between the shape of the posterior margin of the vertebral body and pedicles and the presence of Schmorl's nodes in the lower thoracic spine. The size of the vertebral body in males was also found to correlate with the lesions. Vertebral shape differences associated with the macroscopic characteristics of Schmorl's nodes, indicating severity of the lesion, were also analyzed. The shape of the pedicles and the posterior margin of the vertebral body, along with a larger vertebral body size in males, have a strong association with both the presence and severity of Schmorl's nodes. This suggests that shape and/or size of these vertebral components are predisposing to, or resulting in, vertically directed disc herniation. PMID:23097159

Plomp, Kimberly A; Roberts, Charlotte A; Viðarsdóttir, Una Strand

2012-12-01

390

Arcuate Nucleus Ablation Prevents Fasting-Induced Suppression of ProTRH mRNA in the Hypothalamic Paraventricular Nucleus  

Microsoft Academic Search

Fasting results in reduced thyroid hormone levels and inappropriately low or normal thyroid-stimulating hormone (TSH), partly attributed to central hypothyroidism due to suppression of pro TRH gene expression in the hypothalamic paraventricular nucleus. Recently, we demonstrated that the systemic administration of leptin to fasting animals restores plasma thyroxine (T4) and proTRH mRNA in the paraventricular nucleus to normal, suggesting that

Gabor Legradi; Charles H. Emerson; Rexford S. Ahima; William M. Rand; Jeffrey S. Flier; Ronald M. Lechan

1998-01-01

391

Subfornical organ and hypothalamic paraventricular nucleus connections with median preoptic nucleus neurons: an electrophysiological study in the rat  

Microsoft Academic Search

The role of pathways from the subfornical organ (SFO) to the hypothalamic paraventricular nucleus (PVN) through the median preoptic nucleus (MnPO) in regulating the activity of putative vasopressin (VP)-secreting neurons in the PVN was examined in urethane-anesthetized male rats. The activity of the majority (79%) of SFO neurons antidromically identified as projecting to the MnPO was excited by microiontophoretically (MIPh)

J. Tanaka; H. Saito; H. Kaba

1987-01-01

392

Cardiovascular responses to sciatic nerve stimulation are blocked by paratrigeminal nucleus lesion  

Microsoft Academic Search

The paratrigeminal nucleus (Pa5) receives primary sensory inputs from the vagus, glossopharyngeal, and trigeminal nerves and has efferent projections to the nucleus of the solitary tract (NTS), rostroventrolateral reticular nucleus (RVL), as well as to the nucleus ambiguus (Amb), lateral reticular (LRt), parabrachial (PB) and ventral posteromedial thalamic (VPM) nuclei, suggesting that it may play a significant role in cardiovascular

Yun-Guo Yu; Cristofer A Caous; Antonio C Balan; Giles A Rae; Charles J Lindsey

2002-01-01

393

Brackett Gamma Imaging of the Nucleus of M83  

NASA Astrophysics Data System (ADS)

The gas-rich nucleus of barred spiral galaxy, M83, is a hotbed of star formation, with a total infrared luminosity of 4 X 109 Lo. We have observed the nucleus of M83 with the near infrared spectrometer, NIRSPEC, on Keck 2 to obtain high resolution Br? recombination line spectra of the nucleus. Simultaneous imaging with the SCAM camera in a broadband K filter shows the position of the slit on the near-infrared galaxy. This allows us to map the nucleus with a continuum reference. The SCAM image shows a bright peak at the nucleus and a complex semi-circular arc of emission to the southwest. We stepped the 0.5'' X 24'' length slit in small declination increments to map a 20'' X 20'' region just west of the nucleus. Individual spectra were used to form a ra-dec-lambda cube and an integrated intensity map of Br? . A total of 1.1 X 10-16 W m-2 of Br? emission is detected in the map, in good agreement with previous low resolution observations (Turner, Ho, & Beck 1987, ApJ, 313, 644). This is not corrected for extinction within the molecular clouds in M83 or to the nebulae themselves and is therefore a lower limit to the true Br? flux. Extinction is estimated to be at least a magnitude in the near-IR as measured in larger (4'') beams (Turner et al.) The bulk of the Br? emission extends along the northern portion of the near-IR continuum semi-circle. Twenty percent of the total Br? emission comes from single a 3'' (FWHM) source located 5'' west of the near-IR nucleus. The complementary NIRSPEC Br? data we have obtained will eventually allow us to evaluate the near-IR extinction on subarcsecond sizescales and obtain an extinction-corrected estimate of the Lyman continuum rate and therefore the number of ionizing stars.

Crosthwaite, L. P.; Turner, J. L.; Beck, S. C.; Meier, D. S.

2004-12-01

394

GABAergic pump cells of solitary tract nucleus innervate retrotrapezoid nucleus chemoreceptors.  

PubMed

The retrotrapezoid nucleus (RTN) contains central respiratory chemoreceptors that are inhibited by activation of slowly adapting pulmonary stretch receptors (SARs). Here we examine whether RTN inhibition by lung inflation could be mediated by a direct projection from SAR second-order neurons (pump cells). Pump cells (n = 56 neurons, 13 rats) were recorded in the nucleus of solitary tract (NTS) of halothane-anesthetized rats with intact vagus nerves. Pump cells had discharges that coincided with lung inflation as monitored by the tracheal pressure. Their activity increased when end-expiratory pressure was raised and stopped instantly when ventilation was interrupted in expiration. Many pump cells could be antidromically activated from RTN (12/36). Nine of those were labeled with biotinamide. Of these nine cells, eight contained glutamic acid decarboxylase 67 (GAD67) mRNA and seven were found to reside in the lower half of the interstitial subnucleus of NTS (iNTS). Using the retrograde tracer cholera toxin-B, we confirmed that neurons located in or close to iNTS innervate RTN (two rats). Many such neurons contained GAD67 mRNA and a few contained glycine transporter2 (GLYT2) mRNA. Anterograde tract tracing with biotinylated dextranamide (four rats) applied to iNTS also confirmed that this region innervates RTN by a predominantly GABAergic projection. This work confirms that many rat NTS pump cells are located in and around the interstitial subnucleus at area postrema level. We demonstrate that a GABAergic subset of these pump cells innervates the RTN region. We conclude that these inhibitory neurons probably contact RTN chemoreceptors and mediate their inhibition by lung inflation. PMID:17460107

Takakura, Ana C; Moreira, Thiago S; West, Gavin H; Gwilt, Justin M; Colombari, Eduardo; Stornetta, Ruth L; Guyenet, Patrice G

2007-07-01

395

PREFACE: 11th International Conference on Nucleus-Nucleus Collisions (NN2012)  

NASA Astrophysics Data System (ADS)

The 11th International Conference on Nucleus-Nucleus Collisions (NN2012) was held from 27 May to 1 June 2012, in San Antonio, Texas, USA. It was jointly organized and hosted by The Cyclotron Institute at Texas A&M University, College Station and The Department of Physics and Astronomy at Texas A&M University-Commerce. Among the approximately 300 participants were a large number of graduate students and post-doctoral fellows. The Keynote Talk of the conference, 'The State of Affairs of Present and Future Nucleus-Nucleus Collision Science', was given by Dr Robert Tribble, University Distinguished Professor and Director of the TAMU Cyclotron Institute. During the conference a very well-received public lecture on neutrino astronomy, 'The ICEcube project', was given by Dr Francis Halzen, Hilldale and Gregory Breit Distinguished Professor at the University of Wisconsin, Madison. The Scientific program continued in the general spirit and intention of this conference series. As is typical of this conference a broad range of topics including fundamental areas of nuclear dynamics, structure, and applications were addressed in 42 plenary session talks, 150 parallel session talks, and 21 posters. The high quality of the work presented emphasized the vitality and relevance of the subject matter of this conference. Following the tradition, the NN2012 International Advisory Committee selected the host and site of the next conference in this series. The 12th International Conference on Nucleus-Nucleus Collisions (NN2015) will be held 21-26 June 2015 in Catania, Italy. It will be hosted by The INFN, Laboratori Nazionali del Sud, INFN, Catania and the Dipartimento di Fisica e Astronomia of the University of Catania. The NN2012 Proceedings contains the conference program and 165 articles organized into the following 10 sections 1. Heavy and Superheavy Elements 2. QCD and Hadron Physics 3. Relativistic Heavy-Ion Collisions 4. Nuclear Structure 5. Nuclear Energy and Applications of Nuclear Science and Technologies 6. Nuclear Reactions and Structure of Unstable Nuclei 7. Equation of State of Neutron-Rich Nuclear Matter, Clusters in Nuclei and Nuclear Reactions 8. Fusion and Fission 9. Nuclear Astrophysics 10. New Facilities and Detectors We would like to thank Texas A&M University and Texas A&M University-Commerce for their organizational support and for providing financial support for many students and postdocs and those who had special need. This support helped assure the success of NN2012. Special thanks also go to all members of the International Advisory Committee and the Local Organizing Committee (listed below) for their great work in advising upon, preparing and executing the NN2012 scientific program as well as the social events that all together made the NN2012 an enjoyable experience for both the participants and their companions. NN2012 International Advisory Committee N Auerbach (Israel) J Aysto (Finland) C Beck (France) S Cherubini (Italy) L Ferreira (Portugal) C Gagliardi (USA) S Gales (France) C Gale (Canada) W Gelletly (Great Britain) Paulo R S Gomes (Brazil) W Greiner (Germany) W Henning (USA) D Hinde (Australia) S Hofmann (Germany) M Hussein (Brazil) B Jacak (USA) S Kailas (India) W G Lynch (USA) Z Majka (Poland) L McLerran (USA) V Metag (Germany) K Morita (Japan) B Mueller (USA) D G Mueller (France) T Motobayashi (Japan) W Nazarewicz (USA) Y Oganessian (Russia) J Nolen (USA) E K Rehm (USA) N Rowley (France) B Sherrill (USA) J Schukraft (Switzerland) W Q Shen (China) A Stefanini (Italy) H Stoecker (Germany) A Szanto de Toledo (Brazil) U van Kolck (USA) W von Oertzen (Germany) M Wiescher (USA) N Xu (USA) N V Zamfir (Romania) W L Zhan (China) H Q Zhang (China) NN2012 Local Organizing Committee Marina Barbui Carlos Bertulani Robert Burch Jr Cheri Davis Cody Folden Kris Hagel John Hardy Bao-An Li (Co-Chair and Scientific Secretary) Joseph Natowitz (Co-Chair) Ralf Rapp Livius Trache Sherry Yennello Editors of NN2012 Proceedings Bao-An Li (Texas A&M University-Commerce) and Joseph Natowitz (Texas A&M Unive

Li, Bao-An; Natowitz, Joseph B.

2013-03-01

396

Gas Accretion in the M32 Nucleus: Past and Present  

NASA Astrophysics Data System (ADS)

Using adaptive optics assisted Gemini/NIFS data, I study the present and past gas accretion in the central 3'' of the M32 nucleus. From changes in the spectral slope and CO line depths near the center, I find evidence for unresolved dust emission resulting from black hole (BH) accretion. With a luminosity of ~2 × 1038 erg s-1, this dust emission appears to be the most luminous tracer of current BH accretion, 2 orders of magnitude more luminous than previously detected X-ray emission. These observations suggest that using high-resolution infrared data to search for dust emission may be an effective way to detect other nearby, low-luminosity BHs, such as those in globular clusters. I also examine the fossil evidence of gas accretion contained in the kinematics of the stars in the nucleus. The higher order moments (h3 and h4) of the line-of-sight velocity distribution show patterns that are remarkably similar to those seen on larger scales in elliptical galaxies and in gas-rich merger simulations. The kinematics suggests the presence of two components in the M32 nucleus, a dominant disk overlying a pressure supported component. I discuss possible formation scenarios for the M32 nucleus in the context of the kinematic data as well as previous stellar population studies. The kinematic measurements presented here are the highest quality available for the nucleus of M32, and may be useful for any future dynamical models of this benchmark system.

Seth, Anil C.

2010-12-01

397

Gas Accretion in the M32 Nucleus: Past & Present  

NASA Astrophysics Data System (ADS)

Using adaptive optics assisted Gemini/NIFS data, I study the present and past gas accretion in the central 3" of the M32 nucleus. From changes in the spectral slope and CO line depths near the center, I find evidence for unresolved dust emission resulting from BH accretion. With a luminosity of 2e38 ergs/s, this dust emission is the most luminous tracer of current BH accretion. These observations suggest that using high resolution infrared data to search for dust emission may be an effective way to detect other nearby, low luminosity BHs, such as those in globular clusters. I also examine the fossil evidence of gas accretion contained in the kinematics of the stars in the nucleus. The higher-order moments (h3 and h4) of the line-of-sight velocity distribution show patterns that are remarkably similar to those seen on larger scales in elliptical galaxies and in gas-rich merger simulations. The kinematics suggests the presence of two components in the M32 nucleus, a dominant disk overlying a pressure supported component. I suggest a scenario, in which the nuclear disk formed gradually from the stellar winds of stars in the bulge of M32, that may provide a good explanation of the observed kinematics, stellar populations and abundance gradients seen in the nucleus. The kinematic measurements presented here are the highest quality available for the nucleus of M32, and may be useful for any future dynamical models of this benchmark system.

Seth, Anil

2011-01-01

398

Actin nucleators in the nucleus: an emerging theme  

PubMed Central

Summary Actin is an integral component of the cytoskeleton, forming a plethora of macromolecular structures that mediate various cellular functions. The formation of such structures relies on the ability of actin monomers to associate into polymers, and this process is regulated by actin nucleation factors. These factors use monomeric actin pools at specific cellular locations, thereby permitting rapid actin filament formation when required. It has now been established that actin is also present in the nucleus, where it is implicated in chromatin remodelling and the regulation of eukaryotic gene transcription. Notably, the presence of typical actin filaments in the nucleus has not been demonstrated directly. However, studies in recent years have provided evidence for the nuclear localisation of actin nucleation factors that promote cytoplasmic actin polymerisation. Their localisation to the nucleus suggests that these proteins mediate collaboration between the cytoskeleton and the nucleus, which might be dependent on their ability to promote actin polymerisation. The nature of this cooperation remains enigmatic and it will be important to elucidate the physiological relevance of the link between cytoskeletal actin networks and nuclear events. This Commentary explores the current evidence for the nuclear roles of actin nucleation factors. Furthermore, the implication of actin-associated proteins in relaying exogenous signals to the nucleus, particularly in response to cellular stress, will be considered. PMID:22935654

Weston, Louise; Coutts, Amanda S.; La Thangue, Nicholas B.

2012-01-01

399

The M31 nucleus in the mid-infrared  

NASA Astrophysics Data System (ADS)

The central region of the Andromeda Galaxy (M31) is a complicated place, containing a massive but quiescent black hole, a multi-component nucleus, young stars, cold gas, and ionized gas among other ingredients. While this region has been extensively studied at radio, visible, and X-ray wavelengths, it has received relatively little attention in the mid-infrared. Mid-infrared observations constrain the dust properties of the nucleus and surrounding region. As part of a larger project to study the properties of PAH emission in M31, we obtained Spitzer low-resolution (R~100) spectroscopy of a 30x50 arcsec (114 x 190 pc) region containing the nucleus. We detected 10 micron silicate emission from a marginally resolved source at the center of the galaxy, consistent with emission from an unobscured but weak active nucleus. We also detected the 11.3 micron polycyclic aromatic hydrocarbon (PAH) emission feature, but not other PAH features, from a region about 15 arcsec north of the nucleus. We discuss these spectral features in comparison with those of other nearby low-luminosity AGN and the properties of the M31 supermassive black hole.

Barmby, Pauline; Hemachandra, Dimuthu; Peeters, Els; Willner, Steven P.; Ashby, Matthew; Smith, Howard Alan; Gordon, Karl D.; Smith, Denise A.; Fazio, Giovanni G.

2015-01-01

400

Near-nucleus optical observations of P/Halley  

NASA Technical Reports Server (NTRS)

The Near-Nucleus Studies Net of the International Halley Watch has obtained an extensive series of high resolution optical images of P/Halley during its most active phases in 1985-86 which may be useful in interpreting radio observations of Comet Halley. They often show coma structure resulting from anisotropic emission of dust and gas from the inhomogeneous nucleus. Images were obtained in broadband spectral regions to study dust coma morphology, and in medium to narrow spectral bands to isolate the principal emissions of CN, C3, C2, CO+ and H2O+. The goals and methods of near-nucleus studies are discussed and recent studies of 1910 images are briefly reviewed. The role of dust jets and cometary activity in P/Halley is discussed and several examples of anisotropic emission of dust during the current apparition are shown.

Larson, Stephen M.

1987-01-01

401

Chandra unveils a binary Active Galactic Nucleus in Mrk463  

E-print Network

We analyse Chandra, XMM-Newton and HST data of the double-nucleus Ultraluminous Infrared Galaxy (ULIRG), Mrk463. The Chandra detection of two luminous ($\\mathrm{L}_\\mathrm{2-10 keV}=1.5\\times10^{43}$ and $3.8\\times10^{42}$ erg cm$^{-2}$ s$^{-1}$), unresolved nuclei in Mrk~463 indicates that this galaxy hosts a binary AGN, with a projected separation of $\\simeq3.8$ kpc ($3.83\\pm0.01$ arcsec). While the East nucleus was already known to be a Seyfert 2 (and this is further confirmed by our Chandra detection of a neutral iron line), this is the first unambiguous evidence in favour of the AGN nature of the West nucleus. Mrk463 is therefore the clearest case so far for a binary AGN, after NGC6240.

Stefano Bianchi; Marco Chiaberge; Enrico Piconcelli; Matteo Guainazzi; Giorgio Matt

2008-02-06

402

Interrelation between KOSI experiments and comet nucleus sampling  

NASA Astrophysics Data System (ADS)

In situ observations of Comet Halley yielded information on the nucleus and its environment. The measurements are related to properties of and processes at the nucleus by theoretical modeling and by simulation experiments in the laboratory. The objective of the KOSI experiments at DLR is to study in detail processes which occur near the surface of ice-dust mixtures under irradiation by light, like heat transport into the sample, chemical fractionation of sample material, emission of gasses, and others. The KOSI experiments are carried out at the large space simulation chamber in Koeln. By providing an in-depth understanding of potential cometary process, the results from the KOSI experiments are relevant to any comet nucleus sample return mission.

Grun, E.

1991-04-01

403

Azimuthal harmonics of color fields in a high energy nucleus  

E-print Network

Recent experimental results have revealed a surprisingly rich structure of multiparticle azimuthal correlations in high energy proton-nucleus collisions. Final state collective effects can be responsible for many of the observed effects, but it has recently been argued that a part of these correlations are present already in the wavefunctions of the colliding particles. We evaluate the momentum space 2-particle cumulant azimuthal anisotropy coefficients v_n{2}, n=2,3,4 from fundamental representation Wilson line distributions describing the high energy nucleus. These would correspond to the flow coefficients in very forward proton nucleus scattering. We find significant differences beteen Wilson lines from the MV model and from JIMWLK evolution. The magnitude and transverse momentum dependence of the v_n{2} values suggest that the fluctuations present in the initial fields are a significant contribution to the observed anisotropies.

Lappi, T

2015-01-01

404

102Ru: A pivotal nucleus in the A˜100 region  

NASA Astrophysics Data System (ADS)

The nucleus 102Ru was studied with the GRID lifetime technique and an upper limit on the B(E2:23+?02+) of 21.6 W.u. was obtained. This nucleus is pivotal in the A˜100 region as it marks the boundary, in Z, between nuclei that do, and do not, become deformed with increasing neutron number, and, in N, between those that exhibit characteristics of a phase transition mediated by changes in subshell structure and those that do not. The measurements are discussed primarily in terms of vibrational structure.

Börner, H. G.; Casten, R. F.; Jentschel, M.; Mutti, P.; Urban, W.; Zamfir, N. V.

2011-10-01

405

Separable representation of proton-nucleus optical potentials  

NASA Astrophysics Data System (ADS)

Recently, a new approach for solving the three-body problem for (d,p) reactions in the Coulomb-distorted basis in momentum space was proposed. Important input quantities for such calculations are the scattering matrix elements for proton- (neutron-) nucleus scattering. We present a generalization of the the Ernst-Shakin-Thaler scheme in which a momentum space separable representation of proton-nucleus scattering matrix elements in the Coulomb basis can be calculated. The success of this method is demonstrated by comparing S -matrix elements and cross sections for proton scattering from 12C,48Ca , and 208Pb with the corresponding coordinate space calculations.

Hlophe, L.; Eremenko, V.; Elster, Ch.; Nunes, F. M.; Arbanas, G.; Escher, J. E.; Thompson, I. J.; Torus Collaboration

2014-12-01

406

Active polar region on the nucleus of Comet Halley  

NASA Technical Reports Server (NTRS)

The images of the nucleus of Comet Halley returned by the Giotto spacecraft reveal a number of active regions on the surface, one of which is near the expected location of the rotation pole. This feature is larger and brighter than other source regions, suggesting that the mechanism that drives this source is also different. At this active region near the rotation pole, the sun was circumpolar for a significant portion of the solar encounter. Continuous insolation heated the nucleus to greater depths than in other areas, producing the broad, active polar region.

Reitsema, H. J.; Delamere, W. A.; Whipple, F. L.

1989-01-01

407

Like attracts like: getting RNA processing together in the nucleus.  

PubMed

Structures visible within the eukaryotic nucleus have fascinated generations of biologists. Recent data show that these structures form in response to gene expression and are highly dynamic in living cells. RNA processing and assembly require many factors but the nucleus apparently lacks any active transport system to deliver these to the RNAs. Instead, processing factors move by diffusion but are concentrated by transient association with functionally related components. At sites of high activity this gives rise to visible structures, with components in dynamic equilibrium with the surrounding nucleoplasm. Processing factors are recruited from this pool by cooperative binding to RNA substrates. PMID:10827942

Lewis, J D; Tollervey, D

2000-05-26

408

Neutral current neutrino-nucleus interactions at high energies  

SciTech Connect

We present a QCD analysis of the neutral current (NC) neutrino-nucleus interaction at the small-x region using the color dipole formalism. This phenomenological approach is quite successful in describing experimental results in deep inelastic ep scattering and charged current neutrino-nucleus interactions at high energies. We present theoretical predictions for the relevant structure functions and the corresponding implications for the total NC neutrino cross section. It is shown that at small x, the NC boson-nucleon cross section should exhibit the geometric scaling property that has important consequences for ultrahigh energy neutrino phenomenology.

Gay Ducati, M. B.; Machado, M. M. [High Energy Physics Phenomenology Group, GFPAE, IF-UFRGS, Caixa Postal 15051, CEP 91501-970, Porto Alegre, Rio Grande do Sul (Brazil); Machado, M. V. T. [Centro de Ciencias Exatas e Tecnologicas, Universidade Federal do Pampa, Campus de Bage, Rua Carlos Barbosa, CEP 96400-970, Bage, Rio Grande do Sul (Brazil)

2009-04-01

409

Four-year follow-up results of transforaminal lumbar interbody fusion as revision surgery for recurrent lumbar disc herniation after conventional discectomy.  

PubMed

This study investigated the safety, effectiveness, and clinical and radiological outcomes of transforaminal lumbar interbody fusion (TLIF) for recurrent lumbar disc herniation (rLDH) following previous lumbar spine surgery. Seventy-three consecutive patients treated for rLDH between June 2005 and May 2012 were included in the study. The previous surgical procedures included percutaneous discectomy, discectomy with laminotomy, discectomy with unilateral laminectomy, and discectomy with bilateral laminectomy. The level of rLDH was L4-L5 in 51 patients, L5-S1 in 19 patients, and L3-L4 in three patients. All patients underwent reoperation using the TLIF technique. Outcomes were evaluated using the Oswestry disability index (ODI), visual analogue scale (VAS) scores for low back pain and leg pain, and the Japanese Orthopaedic Association (JOA) score, based on the results of physical examinations and questionnaires. The range of motion and disc height index of the operative segment were compared between preoperative and postoperative radiographs. The mean follow-up period was 4.1years. The VAS scores for low back pain and leg pain, ODI, and JOA score improved significantly between the preoperative and final follow-up evaluations. The mean recovery rate of the JOA score was 89.0%. The disc space height and stability at the fused level were significantly improved after surgery. The fusion rate at the final follow-up was 93.2%. There were no major complications. These results indicate that TLIF can be considered an effective, reliable, and safe alternative procedure for the treatment of rLDH. PMID:25443080

Li, Zhonghai; Tang, Jiaguang; Hou, Shuxun; Ren, Dongfeng; Li, Li; Lu, Xiang; Hou, Tiesheng

2015-02-01

410

Correlation between the prevalence of herniation pits and the alpha angle of the hip: computed tomography evaluation in healthy Chinese adults  

PubMed Central

Background Herniation pits (HPs) commonly develop over time at the femoral head–neck junction in adults, but their cause is still under debate. The purpose of study reported here was to investigate the correlation between the prevalence of HPs of the femoral neck and the alpha angle of the hips of healthy Chinese adults, by using computed tomography (CT). Methods Six hundred and seventy Chinese adults (representing 1145 hips) who had no known diseases affecting the proximal femur and had no symptoms of femoroacetabular impingement underwent a 64-slice CT scan for medical purposes that included the hip in the scan range. Their CT data were analyzed for the prevalence of HPs in the femoral necks and for hip alpha angles. Results The overall prevalence of femoral-neck HPs was 12.5% (143 of 1145 hips). The prevalence in the left versus right femoral necks was 12.1% (69 of 569 hips) versus 12.8% (74 of 576 hips). There was no statistically significant difference between the two sides (?2 = 0.136; p = 0.712). The prevalence of HPs was greater in men than in women (15.9% vs 7.7%; p < 0.01) and greater in adults older than 30 years than in adults younger than 30 years (?2= 14.547; p < 0.01). The alpha angles were greater in the 143 proximal femora with HPs than in the 1002 without pits (39.95° ± 6.01° vs 37.97° ± 5.14°; p < 0.01). Conclusions The prevalence of HPs of the femoral neck in healthy adults was 12.5%, and the prevalence was greater in men than in women. There is a correlation between the prevalence of HPs and the contour of the femoral head–neck junction. The formation of pits may be attributed to the combination of degeneration and morphologic variances in the femoral head–neck junction. PMID:24106774

2013-01-01

411

On the Structure of the Vowel Nucleus: Experimental Evidence.  

ERIC Educational Resources Information Center

A study of consonant-vowel linkages focused on the nature of the vowel boundaries with onset and codas. Subjects judged the status of various word pairs as possible exemplars of a particular manipulation they had been taught to listen for in model nonsense words. The models were of three distinct tasks: (1) a nucleus substitution task, to replace…

Derwing, Bruce R.; And Others

412

Neutral Carbon in the Nucleus of IC 342  

Microsoft Academic Search

We present observations of the neutral carbon 492 GHz emission line from the nucleus of the nearby spiral galaxy, IC 342. Spectra at eight positions were obtained with the Caltech Submillimeter Observatory (CSO). The average N(CI)\\/N(CO) ratio is similar to Milky Way disk values over most of the region sampled. The proximity of the gas to the nuclear starburst has

L. Crosthwaite; D. Meier; J. Turner; D. Benford

1998-01-01

413

TRANSPORT BETWEEN THE CELL NUCLEUS AND THE CYTOPLASM  

Microsoft Academic Search

? Abstract The compartmentation of eukaryotic cells requires all nuclear proteins to be imported from the cytoplasm, whereas, for example, transfer RNAs, messenger RNAs, and ribosomes are made in the nucleus and need to be exported to the cytoplasm. Nuclear import and export proceed through nuclear pore complexes and can occur along a great number of distinct pathways, many of

Dirk Gorlich; Ulrike Kutay

1999-01-01

414

The retrotrapezoid nucleus (RTN): local cytoarchitecture and afferent connections  

Microsoft Academic Search

The retrotrapezoid nucleus (RTN) provides a source of tonic drive to respiratory neurons and is one of many sites for central chemoreception. Here we evaluate in the rat the local neuronal cytoarchitecture in the RTN histologically 2–4 h after neurobiotin injection and the afferent connections to the RTN 24 h after injection. Our neurobiotin injections often overlapped the RTN and

Carlos Cream; Aihua Li; Eugene Nattie

2002-01-01

415

Breeding for Sustainable Milk From Nucleus Herds to Genomic Data  

E-print Network

Breeding for Sustainable Milk Production From Nucleus Herds to Genomic Data Helen Hansen Axelsson: SLU Service/Repro, Uppsala 2013 Cover: Helen Hansen Axelsson #12;Breeding for Sustainable Milk the environmental impact of milk production. The more specific objectives were to obtain new information about

416

Quantum properties of deformation modes of fissile-nucleus motion  

SciTech Connect

The intrinsic mechanisms that are responsible for the pumping of high values of the spins and relative orbital angular momenta of deformed and spherical primary fission fragments and which are induced by the connection between the quantum-mechanical uncertainty principle and the shape of a fissile nucleus are investigated.

Kadmensky, S. G., E-mail: kadmensky@phys.vsu.r [Voronezh State University (Russian Federation)

2008-07-15

417

Relativistic Bohr Model with Finite-Mass Nucleus  

Microsoft Academic Search

An elementary but rigorous treatment is given of the Bohr model of hydrogenlike atoms in which first-order corrections are made for both the finite mass of the nucleus and for the relativistic motion of the electron. Particular attention is paid to the approximations necessary to obtain the energy levels first given by Sommerfeld.

James T. Cushing

1970-01-01

418

Neurobiology of Disease Involvement of the Thalamic Parafascicular Nucleus in  

E-print Network

in patients with traumatic brain injuries (Schiff et al., 2007) and has therapeutic effects in severe, and often resistance to antiepileptic drugs. The parafascicular nucleus (PF) of the thalamus is involved studies showed that deep brain stimulation (DBS) of the CM/PF improves behavioral and motor processes

Paris-Sud XI, Université de

419

Behavioral/Systems/Cognitive Variations in Nucleus Accumbens Dopamine Associated  

E-print Network

and Sheehan, 1997), and oxytocin regulates dopamine-mediated behavioral effects of psychostimulants (Sarnyai behavior (Pedersen et al., 1994), and oxytocin stimulates dopamine release in some cell groups (YuanBehavioral/Systems/Cognitive Variations in Nucleus Accumbens Dopamine Associated with Individual

Champagne, Frances A.

420

Synaptic Arrangements in the Ventral Posterolateral Nucleus of the Squirrel  

Microsoft Academic Search

Because murine rodents have no complex synaptic arrangements in the ventral posterolateral nucleus (VPL), we sought to determine if the lack of complexity was a characteristic common to all rodents. We studied the synaptology of VPL in the fox squirrel, Sciurus niger, using electron microscopy. We found vesicle-containing dendrites and complex synaptic arrangements in the squirrel VPL. Therefore, the relative

J. Wells; B. C. Albright

1983-01-01

421

Comet 162P/Siding Spring: A Surprisingly Large Nucleus  

E-print Network

We present an analysis of thermal emission from comet 162P/Siding Spring (P/2004 TU12) measured during its discovery apparition in 2004 December. The comet showed no dust coma at this time, so we have sampled emission from the comet's nucleus. Observations using the Mid-Infrared Spectrometer and Imager (MIRSI) were performed at NASA's Infrared Telescope Facility, where the peak of the comet's spectral energy distribution was observed between 8 and 25 microns. In combination with the three near-IR spectra presented by Campins et al. (2006, Astron. J. 132, 1346) that show the Wien-law tail of the thermal emission, the data provide powerful constraints on surface properties of the nucleus. We find that the nucleus's effective radius is 6.0+/-0.8 km. This is one of the largest radii known among Jupiter-family comets, which is unusual considering that the comet was discovered only recently. Its geometric albedo is 0.059+/-0.023 in the H band, 0.037+/-0.014 in the R band, and 0.034+/-0.013 in the V band. We also find that the nucleus of 162P has little IR beaming, and this implies that the nucleus has low thermal inertia. Including all near-IR spectra yields a beaming parameter of 1.01+/-0.20. This result is in agreement with others showing that cometary nuclei have low thermal inertia and little IR beaming. If confirmed for many nuclei, the interpretation of radiometry may not be as problematic as feared.

Y. R. Fernandez; H. Campins; M. Kassis; C. W. Hergenrother; R. P. Binzel; J. Licandro; J. L. Hora; J. D. Adams

2006-08-17

422

A direct neuronal connection between the telencephalic nucleus robustus arcopallialis and the nucleus nervi hypoglossi, pars tracheosyringealis in Bengalese finches (Lonchura striata var. domestica).  

PubMed

Bird species with vocal learning possess a projection from the telencephalic nucleus to the nucleus nervi hypoglossi, pars tracheosyringealis (XIIts) in the medulla, where a final common pathway that controls the vocal organ, i.e., the synrinx, originates. The anatomical basis of this projection has not been well investigated in one species of songbird, the Bengalese finch (Lonch