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Stefanakis, Manos. "Biomechanics of intervertebral disc pain". Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.556723.
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'Background: Back pain is strongly (but variably) associated with degeneration of intervertebral discs. Mechanical loading has long been considered one of the causes of disc pathology and pain, but its precise role is poorly understood. In particular the spatial relation between load distribution inside the disc, the disc matrix changes as a result of load and their relationship with pain has not been researched. Methods: Distribution of compressive stress inside intervertebral discs from all regions of the spine was studied using stress profilometry in cadaveric motion segments. Matrix pathological changes were studied using simple histology and light microscopy in two groups of surgically removed discs: 'painful' discs from patients undergoing surgery for suspected discogenic pain, and 'control' discs from patients undergoing surgery for scoliosis or spondylolisthesis reduction. Ingrowth of nerves and blood vessels into the annulus was studied by immunohistochemistry with an endothelial and a general neuronal marker. Stress reduction inside annulus fissures were investigated using stress profilometry. Proteoglycan reduction within annulus fissures was studied by means of a novel, semi-quantitative method involving simple histology and image analysis. Although semi-quantitative, the technique had great spatial resolution and allowed integration with the results from the mechanical experiments. Results: High stress concentrations were localised in the middle annulus and increased with disc degeneration. Associated stress gradients appeared early in the degeneration process and were not diminished in late stage degeneration when substantial compressive loading is transferred to the neural arch. Nerve and blood vessel ingrowth increased with degeneration, but were confined to the outermost 4mm of the annulus. Other cellular changes such as apoptosis, cellular infiltration and proliferation were mostly confined to the annulus. Annulus fissures were found to represent focal regions of low proteoglycan content, and also of low compressive stress, especially when the nucleus was also decompressed. Conclusions: Results suggest that high stress gradients play an important role in progressive annulus disruption, and that annulus fissures provide a microenvironment that is mechanically and chemically conducive to the ingrowth of nerves and blood vessels. Co-localisation of nerves, blood vessels and stress concentrations in the middle-outer annulus suggest that this is the most likely site of discogenic pain. Pain is associated with annulus disruption and the attempted healing rather than age-related degenerative changes in the nucleus.
2
Lemos, Felipe Fernandes [UNESP]. "Influência da desidratação no comportamento mecânico do disco intervertebral lombar". Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/105330.
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A desidratação do núcleo pulposo que, juntamente com o anulus fibroso, compõe o disco intervertebral, participa do processo de degeneração da coluna vertebral. Torna-se importante entender como este processo de desidratação e a consequente alteração das propriedades mecânicas influenciam na biomecânica dessa articulação. O principal objetivo deste estudo é analisar a influência da desidratação no coeficiente de amortecimento viscoso e como esta variação pode alterar o comportamento mecânico do disco intervertebral lombar. Este estudo é composto de duas etapas: na primeira, o coeficiente de amortecimento viscoso foi obtido experimentalmente de unidades funcionais de colunas lombares suínas antes e após o processo de desidratação das mesmas; na segunda, foi simulado em modelo computacional a resposta harmônica, utilizando-se dados da literatura e do coeficiente de amortecimento viscoso, analisando as diferenças entre uma simulação com o disco intervertebral hidratado e desidratado. O coeficiente de amortecimento viscoso hidratado (4,7) e desidratado (2,7) apresentou diferença estatisticamente significante (p<0,001). Na simulação computacional podese evidenciar uma menor influência da variação do coeficiente de amortecimento viscoso quando analisado de forma isolada do que quando analisado em conjunto com variações nos dados referentes à rigidez, principalmente nas frequências de ressonância e nas amplitudes de pressão intradiscal e deformação do disco intervertebral. Concluiu-se que discos intervertebrais desidratados respondem de forma diferente à vibração, o que pode contribuir para os processos lesivos da coluna vertebral
The dehydration of the nucleus pulposus which, with the anulus fibrosus, composes the intervertebral disc, participates in the process of degeneration of the spine. It is important to understand how this process and the consequent alteration of dehydration of the mechanical properties influence the biomechanics of this joint. The aim of this study is to analyze the influence of dehydration in the viscous damping coefficient and how this variation can change the mechanical behavior of lumbar intervertebral disc. This study consists of two stages: first, the viscous damping coefficient was obtained experimentally in functional units of porcine lumbar spine before and after the dehydration process of them; second, an harmonic response was simulated in a computer model, using literature data and the viscous damping coefficient, analyzing the differences between a simulation with the hydrated and dehydrated intervertebral disc. The hydrated (4.7) and dehydrated (2.7) viscous damping coefficient showed a statistically significant difference (p <0.001). In the computer simulation, a lower influence of variation of the viscous damping coefficient can be detected when analyzed separately than when analyzed together with variation on stiffness data, especially in the resonance frequencies and in the amplitudes of the intradiscal pressure and deformation of the intervertebral disc. We conclude that dehydrated intervertebral discs respond differently to vibration, what can contribute to the damaging processes of the spine
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González, Guitiérrez Ramiro Arturo. "Biomechanical study of intervertebral disc degeneration". Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/76781.
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Degeneration and age affect the biomechanics of the intervertebral disc, by reducing its stiffness, flexibility and shock absorption capacities against daily movement and spinal load. The biomechanical characterization of intervertebral discs is achieved by conducting mechanical testing to vertebra-disc-vertebra segments and applying axial, shear, bend and torsion loads, statically or dynamically, with load magnitudes corresponding to the physiological range. However, traditional testing does not give a view of the load and deformation states of the disc components: nucleus pulposus, annulus fibrosus and endplate. Thus, the internal state of stress and strains of the disc can only be predicted by numerical methods, one of which is the finite element method. The objective of this thesis was, to study the biomechanics of degenerated intervertebral discs to load conditions in compression, bending and torsion, by using mechanical testing and a finite element model of disc degeneration, based on magnetic resonance imaging (MRI). Therefore, lumbar discs obtained from cadavers corresponding to spinal levels L2-L3 and L4-L5 with mild to severe degeneration were used. Intervertebral osteochondrosis and spondylosis deformans were identified, being the disc space collapse, the most striking feature. Next, all discs were tested to static and dynamic load conditions, the results gained corresponded to the disc stiffness (in compression, bending and torsion), stress relaxation and dynamic response. Of these, the stiffness response was used to validate the disc model. The testing results suggest that discs with advanced degeneration over discs with mild degeneration are, less rigid in compression, less stiffer under bending and torsion, showed less radial bulge, and reduce their viscoelastic and damping properties. This study shows that degeneration has an impact on the disc biomechanical properties which can jeopardize normal functionality. Development of one finite element model of disc degeneration started by choosing a MRI of a L2-L3 disc. Segmentation of vertebra bone and disc materials followed, and were based on pixel brightness and radiology fundamentals, then a finite element mesh was created to account for the disc irregular shape. The disc materials were modeled as hyperelastic and the bone materials were modeled as orthotropic and isotropic. Adjustment of material properties was based on integrity of the annulus fibrosus, giving a stiffness value matching that of a mild degeneration disc. Then, validation of the model was performed, and included a study of the distributions of stress and strain under loads of compression, bending and torsion. The results from all load simulations show that the disc undergoes large deformations. In contrast, the vertebrae are subjected to higher stress but with negligible deformations. In compression, the model predicted formation of symmetrical disc bulge which agree with the testing behavior. The nucleus pulposus showed to be the principal load carrier with negative principal stresses and strains. In bending and torsion, the annulus fibrosus showed to be the principal load carrier with large symmetrical principal strains and stresses for the former loading and large shearing for the latter. The study showed the importance of soft tissue deformation, mostly noticed in advanced degeneration. In contrast, the higher stresses in the vertebra over those of the intervertebral disc showed the relevance of bone predisposition to fracture. Such kind of studies, should contribute to the understanding of the biomechanics of the intervertebral disc.La degeneración y edad afectan la biomecánica del disco intervertebral, reduciendo la capacidad de rigidez, flexibilidad y atenuación de impactos, contra el movimiento y carga del raquis. La caracterización biomecánica del disco se realiza con ensayos mecánicos a segmentos de vértebra-disco-vértebra y aplicando cargas axiales, cortantes, flexión y torsión, estáticas ó dinámicas, con magnitudes de carga según el intervalo fisiológico. Sin embargo, las pruebas tradicionales no dan una visión de los estados de carga y deformación de los componentes del disco: núcleo pulposo, anillo fibroso y placa terminal. Por lo tanto, el estado interno de esfuerzos y deformaciones del disco, solo puede ser predicho con métodos numéricos, uno de los cuales es el método de elemento finito. El objetivo de esta tesis fue, estudiar la biomecánica de discos intervertebrales degenerados a las condiciones de carga en compresión, flexión y torsión, mediante el uso de ensayos mecánicos y de un modelo de elementos finitos de la degeneración de disco, basado en imágenes con resonancia magnética (MRI). Por lo tanto, se usaron discos lumbares L2-L3 y L4-L5 obtenidos de cadáveres, con degeneración leve a severa. Se identificó osteocondrosis intervertebral y espondilosis deformante, siendo el colapso del espacio intervertebral el aspecto más relevante. Luego, todos los discos fueron ensayados a condiciones de carga estática y dinámica, y los resultados correspondieron a la rigidez del disco (a compresión, flexión y torsión), a la relajación de tensiones y a la respuesta dinámica. De éstos, la rigidez fue usada para validar el modelo de disco. Los resultados de los ensayos sugieren que los discos con degeneración avanzada sobre aquellos con degeneración leve son, menos rigidos a compresión, menos rigidos a flexión y torsión, presentan menor protuberancia radial, y reducen sus propiedades viscoelásticas y de amortiguamiento. El estudio muestra que la degeneración impacta las propiedades biomecánicas del disco, poniendo en riesgo la funcionalidad normal. El desarollo de un modelo de elementos finitos de la degeneración de disco inició eligiendo una secuencia de resonancia magnética de un disco L2-L3. La segmentación de los materiales del disco y de las vértebras se realizó basado en intensidad de brillo del pixel y en fundamentos de radiología, y se creó una malla de elementos finitos correspondiente a la forma irregular del disco. Los materiales del disco se modelaron como hiperelásticos y los tejidos óseos se modelaron como materiales ortotrópicos e isotrópicos. El ajuste de propiedades de los materiales fue basado en la integridad del anillo fibroso, y dio una rigidez correspondiente a la de un disco con degeneración leve. Luego, se realizó la validación del modelo, e incluyó un estudio de las distribuciones de esfuerzo y deformación a las condiciones de carga en compresión, flexión y torsión. Los resultados de todas las simulaciones de carga mostraron que el disco es sometido a grandes deformaciones. En contraste, las vértebras fueron sometidas a mayores esfuerzos pero con deformaciones insignificantes. En compresión, el modelo predijo la formación de una protuberancia radial simétrica, en concordancia con la experimentación. El núcleo pulposo mostró ser el portador principal de carga, con tensiones y deformaciones principales negativas. En flexión y torsión, el anillo fibroso mostró ser el portador principal de carga, con grandes deformaciones y tensiones principales simétricas para la primera carga, y con grandes tensiones cortantes para la segunda carga. El estudio mostró la importancia de las deformaciones de los tejidos blandos, principalmente notados en la degeneración avanzada. Por el contrario, las tensiones mayores en los cuerpos vertebrales sobre aquellas del disco intervertebral mostraron la relevancia de la predisposición a las fracturas óseas. Este tipo de estudio debe contribuir a la comprensión de la biomecánica del disco intervertebral.
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Osti, Orso L. "Annular tears and intervertebral disc degeneration /". Title page, contents and abstract only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09pho85.pdf.
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Liu, Jane J. "Proteoglycans of the human intervertebral disc". Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68204.
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The composition and heterogeneity of human intervertebral disc proteoglycans from different aged individuals were investigated. (1) The glycosaminoglycan content in the nucleus pulposus was greater than that in the annulus fibrosus at all ages. Glycosaminoglycan content increased from the infant to the young adult, and then decreased from the young to the mature adult. (2) Disc contained a higher content of hyaluronate than articular cartilage at all ages. (3) Proteolytically modified LP3 was predominant in the disc. (4) Very low link protein concentrations were observed in adult disc proteoglycan preparations and adult disc extracts analysed by SDS/PAGE and immunoblotting suggesting a deficiency in link protein content. In contrast, radioimmunoassay of disc extracts suggests no deficiency in link protein content. (5) The existence of extremely fragmented link protein in adult disc is postulated to reconcile the results of the two analytic methods. (6) Non-proteoglycan forms of biglycan and decorin are present in the disc. The difference between the two non-proteoglycan forms of biglycan appears to be due to different N-linked oligosaccharide substitution rather than proteolysis.
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Naish, Claudia Martha. "Ultrasound imaging of the intervertebral disc". Thesis, University of Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288301.
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Molinari, Michael B. "Mechanical fractionation of the intervertebral disc". Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:7385c54f-a3d0-4467-aca4-c7a9b8686982.
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Chronic lower back pain is a major public health problem, with direct and indirect economic costs comparable to those of heart disease, depression and diabetes. In many cases this pain derives from degeneration of the intervertebral disc (IVD), a fibrous, avascular tissue that sits between the vertebrae in the spinal column. A novel treatment approach for this ‘discogenic’ pain is the injection of a hydrogel that hybridises in situ and restores the normal biomechanical function of the disc. While a number of promising materials are currently under development, existing approaches to removing degenerate material from the disc prior to injection are invasive and compromise the structural integrity of the disc. Mechanical fractionation of the tissue using acoustic cavitation generated by high intensity focussed ultrasound (HIFU) has the potential to be non-invasive, and to enhance the effectiveness of the procedure by preserving the outer regions of the disc. The primary goal of this thesis is to investigate the feasibility of this approach. The acoustic properties of the disc were first measured using a modified scanning acoustic microscope. The outer region of the disc, the annulus fibrosus (AF) was found to be highly attenuative compared to the central nucleus pulposus (NP). These measured properties were then used in a simplified two-dimensional model to simulate the shape of the acoustic pressure field within the disc. A configuration using two confocal spherically focussed 0.5 MHz single-element transducers was able to produce a tightly focused field suitable for use in the IVD. As preliminary experiments suggested that high pressure amplitudes were required to initiate cavitation inside the disc, the use of exogenous nuclei to lower this threshold was investigated. A novel class of solid sonosensitive nanoparticles (SNPs) suitable for use in the IVD were developed and characterised. These SNPs comprise a layer of hydrophobic silica particles deposited onto a polystyrene core, and are thought to trap small gas pockets in surface crevices. Coated particles were found to reduce the cavitation threshold significantly in both water and blood, from some 2.0 - 2.5 MPa at 1.067 MHz to below 1.0 MPa. The particles were also found to provide repeatable initiation of cavitation activity during prolonged or repeated exposures, and to exhibit good storage stability, suggesting that they they may be appropriate for use within the IVD. Finally, a combined therapy and monitoring system was designed, built and validated. The system comprised two confocal 0.5 MHz spherically focussed HIFU transducers with central openings, each co-axially aligned with either a single element passive cavitation detector or a 64-element array that could be used for both active and passive imaging. The system was found to be capable of initiating inertial cavitation in the disc at pressures as low as 2.5MPa in the presence of sonosensitive nanoparticles. Use of the array in active mode enables creation of a B-mode image that provides anatomical information on the boundaries of the IVD, whist the same array could be used for passive mapping of acoustic emissions arising fromthe HIFU focus during therapy. Two different exposure regimes were found to be capable of producing sizeable perforations within the NP without significantly damaging the AF, and preliminary investigations were carried out into themechanism of damage. The location and extent of cavitation as seen on passive maps acquired during treatment was found to coincide with the regions of NP fractionation. This confirms that passive acoustic mapping can provide the real-time treatment monitoring necessary to ensure both safety and efficacy of ultrasonic IVD fractionation. Prior to clinical application, a significant amount of further development is required to further validate non-invasive disc fractionation by HIFU and the subsequent steps for minimally invasive disc replacement using injectable hydrogels. The present work has nonetheless demonstrated for the first time that minimally invasive removal of degenerate disc tissue is feasible trough the combined use of sonosensitive nanoparticles and a relatively low-cost therapeutic ultrasound system that provides simultaneous anatomical imaging and real-time treatment monitoring by passive acoustic mapping.
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Luxmoore, Bethany Jane. "Computational simulation of the intervertebral disc". Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/4685/.
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The intervertebral disc is a complex structure unlike any other in the human body. The capability to withstand high loads and deformations in six degrees of freedom is facilitated by the unique soft tissue structures. However, the mechanical behaviour of these tissues is not well understood. The aim of this project was to investigate methods of deriving structural information about the tissues of the intervertebral disc for application in computational simulation, with particular focus on the mechanical function of the annulus fibrosis and how the behaviour of this tissue is governed by its substructures. Magnetic resonance imaging techniques were assessed for potential to inform specimen specific models of the disc. Imaging sequences were developed and validated to image in vitro disc samples in unloaded and compressed states. These images captured the lamellar structure of the annulus in three dimensions to a level of detail not previously published. The image data facilitated the development of a novel method of specimen specific model construction, as well as providing experimental deformation data, against which the models were directly validated. Sensitivity analyses on both generalised and specimen specific models illustrated the influence of interlamellar interaction representation on the gross mechanics of the disc models. The models were adapted to illustrate the effects of tissue degeneration and intervention on disc mechanics Interlamellar interactions and tissue level mechanics were further investigated by developing specimen specific models of disc tissue samples based on microscopy data. Novel methods were developed to implement qualitative histological data into finite element analyses of annulus tissue samples. Interlamellar interactions were shown to provide a strong bond between lamellae. The parameters and variables involved in the mechanical system of the disc pose major challenges for experimental investigation. This study has successfully laid the ground work to negotiate these challenges using a computational approach
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Jim, Jin-to. "Genetics and molecular characterization of degenerative disc disease". Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B35720189.
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Chan, Kit-ying, i 陳潔瑩. "Development of whole disc organ culture system and acellular disc scaffold for intervertebral disc engineering". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45600077.
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Jim, Bernice. "Early developments of an intervertebral disc model using bovine coccygeal discs". Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110397.
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Degeneration of the lumbar disc, which frequently leads to low back pain, is an age related disease that often diminishes a patient's quality of life. Despite the continued efforts of research in this area, biological understanding of the disease remains unclear. The treatment strategies are few, with the gold standard being fusion of the motion segment, which permanently prevents any motion at the treated level of the spine. Although there are several new treatments available that attempt to recover some mechanical function of the motion segment, such as arthroplasty, they all remain unsatisfactory in doing so. The biggest challenge that researchers face in this area is the lack of tools to increase the understanding of disc degeneration etiology in order to develop better treatment strategies. The long-term goal of the research conducted in this thesis is to develop an in-vitro intervertebral disc organ culture model using bovine coccygeal discs as an experimental platform to advance disc degeneration understanding and treatment.This thesis begins with the development of a culture environment for the in-vitro culture model and ends with early work on the biological validation of a cultured bovine coccygeal tissue model. A comprehensive introductory chapter, with information reviewing current research in the area, is included to help readers to familiarize themselves with the topic. This is followed by a description, in technical terms, of the in-vitro organ culture system that was developed and its validation and application towards the development of the organ culture. To follow is the largest contribution, presentation of a new harvest method to isolate intervertebral disc tissue for culturing. The results of the investigation provide insight on the nutritional and mechanical aspects of the disc preserved in an in-vitro organ culture. Experimental studies are developed and analysis methods are considered, determining the best method to validate an in-vitro organ culture model. Preliminary investigations to establish culturing up to two weeks is presented, as well as the beginnings of an induced injury model.The early works in the development of a bovine in-vitro organ culture model that is presented in this thesis research will hopefully mark the beginning of a useful tool to further understand intervertebral disc degeneration and more importantly become a platform to develop and test new treatment strategies. The text aims to provide a reference source for researchers, orthopaedic surgeons, and orthopaedic manufacturers, stimulating further advances in disc degeneration understanding and treatment.Debuts d'un modèle de culture d'organe appliqué au disque intervertébral avec tissu coccygien bovin.}La dégénération des disques lombaires, qui conduit fréquemment à la lombalgie, est une affection liée au vieillissement qui diminue souvent la qualité de vie du patient. Malgré une recherche continue dans ce domaine, la compréhension biologique de cette maladie demeure limitée. Il existe peu de stratégies de traitement, la référence dans ce domaine étant la fusion d'un segment articulaire, qui empêche tout mouvement du niveau traité de la colonne vertébrale de manière permanente. Bien qu'il existe quelques nouveaux traitements qui permettent de récupérer une partie des fonctions, telle que l'arthroplastie, ceux-ci n'ont mené à rien de concluant. Le plus gros challenge que les chercheurs affrontent dans ce domaine est le manque d'outils qui augmenteraient la compréhension de l'étiologie de la dégénération du disque, ceci afin de développer de meilleures stratégies de traitement. Le but à long terme de la recherche conduite dans cette thèse est de développer un modèle in vitro de culture de disque utilisant des disques bovins coccygien comme plateforme expérimentale pour améliorer la compréhension et le traitement de la dégénération de disque.Cette thèse commence avec le développement d'un environnement de culture pour le modèle in vitro et se termine avec une validation biologique du tissu coccygien bovin cultivé. Un chapitre d'introduction passant en revue les informations concernant la recherche actuelle dans ce domaine aidera les lecteurs à se familiariser avec ce domaine. Ce chapitre est suivi d'une description, en termes techniques, du système de culture in vitro qui été développé, sa validation et son application pour le développement de la culture d'organe. S'ensuit une investigation des différentes méthodes de récolte proposées et évaluées pour isoler le tissue de disque intervertébral utilisé pour la culture. Les résultats de cette investigation apportent des informations sur les aspects mécaniques et nutritionnels d'un disque préservé dans une culture d'organe in vitro. Des études expérimentales sont développées et des méthodes d'analyses sont considérées, afin de déterminer la meilleure méthode pour valider le modèle de culture d'organes in vitro. Une investigation préliminaire examinant les effets de la simulation mécaniques dans une expérience de culture de deux semaines et validant les conditions de culture est présentée ainsi que les débuts d'un modèle avec lésions.Le modèle bovin de culture d'organe in vitro présenté dans cette recherche de thèse marque les débuts d'un outil utile pour mieux comprendre la dégénération du disque intervertébral et avant tout pour développer et tester des nouvelles stratégies de traitement. Le texte apportera une source de référence pour les chercheurs, les chirurgies et les entreprises orthopédiques, et encouragera des avancées dans le traitement et la compréhension de la dégénération du disque.
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Lemos, Felipe Fernandes. "Influência da desidratação no comportamento mecânico do disco intervertebral lombar /". Guaratinguetá : [s.n.], 2011. http://hdl.handle.net/11449/105330.
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Resumo: A desidratação do núcleo pulposo que, juntamente com o anulus fibroso, compõe o disco intervertebral, participa do processo de degeneração da coluna vertebral. Torna-se importante entender como este processo de desidratação e a consequente alteração das propriedades mecânicas influenciam na biomecânica dessa articulação. O principal objetivo deste estudo é analisar a influência da desidratação no coeficiente de amortecimento viscoso e como esta variação pode alterar o comportamento mecânico do disco intervertebral lombar. Este estudo é composto de duas etapas: na primeira, o coeficiente de amortecimento viscoso foi obtido experimentalmente de unidades funcionais de colunas lombares suínas antes e após o processo de desidratação das mesmas; na segunda, foi simulado em modelo computacional a resposta harmônica, utilizando-se dados da literatura e do coeficiente de amortecimento viscoso, analisando as diferenças entre uma simulação com o disco intervertebral hidratado e desidratado. O coeficiente de amortecimento viscoso hidratado (4,7) e desidratado (2,7) apresentou diferença estatisticamente significante (p<0,001). Na simulação computacional podese evidenciar uma menor influência da variação do coeficiente de amortecimento viscoso quando analisado de forma isolada do que quando analisado em conjunto com variações nos dados referentes à rigidez, principalmente nas frequências de ressonância e nas amplitudes de pressão intradiscal e deformação do disco intervertebral. Concluiu-se que discos intervertebrais desidratados respondem de forma diferente à vibração, o que pode contribuir para os processos lesivos da coluna vertebralAbstract: The dehydration of the nucleus pulposus which, with the anulus fibrosus, composes the intervertebral disc, participates in the process of degeneration of the spine. It is important to understand how this process and the consequent alteration of dehydration of the mechanical properties influence the biomechanics of this joint. The aim of this study is to analyze the influence of dehydration in the viscous damping coefficient and how this variation can change the mechanical behavior of lumbar intervertebral disc. This study consists of two stages: first, the viscous damping coefficient was obtained experimentally in functional units of porcine lumbar spine before and after the dehydration process of them; second, an harmonic response was simulated in a computer model, using literature data and the viscous damping coefficient, analyzing the differences between a simulation with the hydrated and dehydrated intervertebral disc. The hydrated (4.7) and dehydrated (2.7) viscous damping coefficient showed a statistically significant difference (p <0.001). In the computer simulation, a lower influence of variation of the viscous damping coefficient can be detected when analyzed separately than when analyzed together with variation on stiffness data, especially in the resonance frequencies and in the amplitudes of the intradiscal pressure and deformation of the intervertebral disc. We conclude that dehydrated intervertebral discs respond differently to vibration, what can contribute to the damaging processes of the spine
Orientador: José Elias Tomazini
Coorientador: Mauro Hugo Mathias
Banca: Fernando de Azevedo Silva
Banca: José Geraldo Trani Brandão
Banca: Valdeci Donizete Gonçalves
Banca: Magda Francisca Gonçalves Rocha
Doutor
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Kelempisioti, A. (Anthi). "Genetic risk factors for intervertebral disc degeneration". Doctoral thesis, Oulun yliopisto, 2016. http://urn.fi/urn:isbn:9789526211350.
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Abstract Low back pain (LBP) is the leading cause of years lived with disabilities worldwide. Intervertebral disc (IVD) degeneration is a strong contributing factor to LBP. Recent studies have shown that genetic determinants contribute markedly to IVD degeneration but knowledge about the actual genes involved as well as their roles is still limited. The aim of this thesis work was to study genetic factors that may predispose to IVD degeneration. Using both family and case-control association study designs, variants in five genes showed association with IVD degeneration on magnetic resonance imaging (MRI) in a population-based sample and among patients with sciatica due to lumbar disc herniation (LDH). We performed a candidate gene association study of the known variants implicated in IVD degeneration in a Finnish cohort of 538 young individuals with a moderate degree of lumbar IVD degeneration on MRI. We were able to confirm the associations of variants in the IL6, SKT, and CILP genes, which provides further evidence for true associations. Based on our earlier linkage study in Finnish sciatica families, we performed a candidate gene analysis and identified IL17F as a potential candidate gene. To the best of our knowledge this is the first study to observe an association between this gene and discogenic sciatica. Both IL-6 and IL-17 are pro-inflammatory cytokines with elevated expression levels in herniated tissues, which suggest a role in IVD degeneration. Study of the role of genes coding for inflammatory mediators is of interest as it may contribute to the understanding of the overall inflammatory response of the disc. In addition, we reported on the involvement of SKT in the etiology of lumbar disc herniation (LDH) both in Japanese and Finnish case-control samples. Experimental studies in mice have shown that Skt homozygous mutants exhibit disc abnormalities resulting in a kinky tale phenotype. We hypothesized that the human homolog SKT could have long-term importance in the onset of IVD degeneration by making the discs more vulnerable. Finally, through linkage studies and in the subsequent association analyses, the role of CHST3 as a novel risk factor for IVD degeneration was identified. CHST3 encodes an enzyme that catalyzes the sulfation of chondroitin, and mutations in this gene are associated with spondylepiphyseal dysplasia and humerospinal dysostosis. In our study, we identified this gene using genome –wide linkage based on data from a Southern Chinese family and speculated that mild CHST3 reduction caused by the reported susceptibility SNP could result in disc degeneration in adults in conjunction with other risk factors. This thesis provides new information about the genetic background of IVD degeneration and new insights into the etiology of the disease. The specific roles of these genes in the IVD function and pathogenesis of sciatica are not clear however, and need to be elucidatedTiivistelmä Alaselkäkipu on yksi yleisimmistä sairauksista ja johtava syy työkyvyttömyyteen. Välilevyrappeuma myötävaikuttaa merkittävästi alaselän kipuun. Vaikka aiemmat tutkimukset ovat osoittaneet, että perintötekijöillä on vahva osuus välilevyrappeumaan, altistavat geenit ja niiden rooli tunnetaan huonosti. Tämän tutkimuksen tavoitteena oli arvioida tiettyjen perintötekijöiden osuutta välilevyrappeumassa ja tunnistaa taudille altistava geeni perheaineistossa aiemmin havaitulta kromosomialueelta. Aineistoina tutkimuksessa olivat perheaineistot sekä laajat potilas-kontrolliaineistot suomalaisesta ja aasialaisista väestöistä. Tutkimuksessa osoitimme, että perimän vaihtelut viidessä tutkitussa geenissä altistivat erilaisille välilevyrappeuman taudin muodoille. Tutkimus, jossa analysoimme aiemmin tunnistettuja alttiusgeenejä, vahvisti IL6, SKT ja CILP geenien vaihteluiden osuuden taudin alttiustekijöinä. Tutkimusaineistona oli pohjoissuomalainen syntymäkohortti, jossa välilevyrappeuma oli määritetty magneettikuvauksella (MRI). Suomalaisessa perheaineistossa tehdyn kokogenomin laajuisen kartoituksen pohjalta analysoimme IL17F geenin mahdollisena uutena alttiusgeeninä oireiselle välilevytaudille. Kahdesta geenin variantista koostuva haplotyyppi assosioitui tautiin merkitsevästi. Lisäksi osoitimme, että SKT-geenin tietty muutos altistaa välilevyn pullistumille sekä japanilaisessa että suomalaisessa potilasaineistossa. Hiirikokeissa on havainnoitu, että SKT-geenin homotsygootti mutaatio johtaa välilevy-poikkeamaan, joka edelleen aiheuttaa hiiren poikkeavan häntäilmiasun-. Hypoteesimme oli, että ihmisen SKT -geeni voi myötävaikuttaa välilevypullistuman kehittymiseen altistamalla välilevyt rappeumalle. Edelleen, laajassa usean populaation aineiston käsittävässä tutkimuksessa osoitimme CHST3-geenin muutoksen altistavan välilevyrappeumalle. Peittyvästi periytyvät muutokset tässä geenissä aiheuttavat perinnöllisiä harvinaisia luusairauksia. Tämä väitöstutkimus tarjoaa uutta tietoa välilevyrappeuman geneettisestä taustasta ja auttaa taudin syiden tutkintaa. Geenien rooli välilevyn toiminnassa ja muutosten vaikutus taudin kulkuun vaativat kuitenkin vielä lisätutkimuksia
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Hristova, Gergana. "Calcification in Intervertebral Disc Degeneration and Scoliosis". Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=86948.
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In degenerative and scoliotic intervertebral discs (IVD), calcification is a pathological process that may lead to impairment of the nutrient supply and a disturbance in disc metabolism. However, the process of calcification in disc degeneration and scoliosis is not well understood. The purpose of this study was to assess the calcification markers in IVD of patients with degenerative disc disease and adolescent idiopathic scoliosis. For this purpose, 34 IVDs from 16 adult patients with degenerative disc disease and 25 IVDs from 9 adolescent patients with adolescent idiopathic scoliosis were obtained after surgery or autopsy. The concave and the convex parts of the scoliotic discs were analyzed separately. Von Kossa staining was performed to visualize calcium deposits, while type X collagen expression, which is associated with endochondral ossification, was measured by immunohistochemistry and Western blot. Alkaline phosphatase (ALP) activity and calcium and inorganic phosphate (Pi) concentrations were used as markers of the calcification process. Results showed the presence of calcium deposits and type X collagen only in degenerative and scoliotic intervertebral discs, but not in control discs. Results also demonstrated a large individual variability in ALP activity and calcium and Pi concentrations in degenerative and scoliotic discs. Moreover, the level of the calcification markers was consistently higher in degenerative and scoliotic discs than in control discs. The results suggest that disc degeneration in adults involves mineral deposition and that mineralization in adolescent idiopathic scoliosis discs might reflect an ongoing premature degenerative process.Dans les disques intervertébraux (DIV) dégénérés et de scoliose, la calcification est un processus pathologique qui peut mener à une diminution de l'apport nutritif et à un débalancement du métabolisme. Cependant, le processus de calcification de ces disques est très peu connu. Le but de la présente étude était d'évaluer le potentiel de calcification des DIVs de patients avec une maladie dégénérative des disques (MDD) ou avec une scoliose idiopathique chez l'adolescent (SIA). Pour ce faire 34 DIVs provenant de 16 adultes avec MDD et 25 DIVs de 9 patients avec SIA ont été obtenus après chirurgie ou autopsie. Les côtés convexe et concaves des disques scoliotiques on été analysés séparément. Une coloration de Von Kossa a été faite afin de visualiser les dépôts de calcium alors que l'expression du collagène de type X, associé à l'ossification endochondrale, a été mesurée par immunohistochimie et par buvardage de type Western. L'activité de la phosphatase alcaline (PA) ainsi que les concentrations de calcium et de phosphate inorganique (Pi) ont servi d'indicateurs du potentiel de calcification. Les résultats montrent la présence de dépôts de calcium et de collagène de type X uniquement dans les DIVs des patients ayant une MDD ou une SIA, mais non dans les disques témoins. Les résultats montrent également une grande variabilité individuelle de l'activité de la PA ainsi que des concentrations de calcium et de Pi. De plus, les niveaux de ces marqueurs du potentiel de calcification était plus élevés dans les disques dégénérés et scoliotiques que dans les disques témoins. Les résultats suggèrent que la dégénération du disque intervertébral adulte est associée à une déposition de minéraux et que la minéralisation du disque scoliotique pourrait refléter un processus de dégénération prématurée.
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Lam, Ka-lok Stephen, i 林家樂. "Biomechanics of the intervertebral disc allograft transplantation". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43773904.
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Johnson, Scott. "Scanning acoustic microscopy of the intervertebral disc". Thesis, University of Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393922.
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Fahmy, Amr. "Measuring the pressure of the intervertebral disc". Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/361604/.
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Spinal musculoskeletal conditions are an economical burden; in the United States alone, the annual cost of these conditions is estimated to be $254 billion. These conditions are also a social burden; in the United States, for example, musculoskeletal problem is the number one reason for a visit to a physician. Most of these conditions are caused by degenerative changes in the vertebral column. Such degenerations are, often, the result of long-term changes in the intervertebral disc pressure. To date, the standard methodology to measure this pressure suffers from being invasive, which prevents it from being widely applicable. Thus, developing a validated, non-invasive method for measuring the intervertebral disc pressure can be a valuable diagnostic tool. An ideal, non-invasive, solution to measure the pressure of the intervertebral disc would be to use MRI scanners; they are safe and widely available. To date, however, there have been no studies to validate, or invalidate, this proposal. Thus, the main goal of the dissertation is to provide the corner stone for studying this proposal. To this end, the proposed approach consists of three steps: (1) measuring the pressure within the intervertebral disc, (2) obtaining an MR image for the same disc, and (3) comparing the two and finding whether a link exists between them. This dissertation contributes towards the first step by developing, and validating, a layout suitable for in-vitro application to spinal motion segments.
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Lam, Ka-lok Stephen. "Biomechanics of the intervertebral disc allograft transplantation". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43773904.
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Ho, Wai-hung Daniel. "Genetic study of lumber disc degeneration". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42841215.
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Bibby, Susan R. S. "Cell metabolism and viability in the intervertebral disc". Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249331.
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Jackson, Alicia R. "Transport and Metabolism of Glucose in Intervertebral Disc". Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/479.
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Low back pain is a major social and economic dilemma in the United States. Despite its high impact, the origins of low back remain unclear. Nonetheless, degenerative changes to the intervertebral discs (IVD) of the spine have been implicated as a possible source leading to pain. Poor nutritional supply to the IVD is believed to play a primary role in the pathophysiology of disc degeneration. Since the disc is avascular, vital nutrients, such as glucose, must be supplied by surrounding blood vessels. However, the transport and metabolic properties of glucose in the IVD have not been fully delineated. This knowledge is necessary in order to elucidate the nutrition-related mechanisms of disc degeneration. Therefore, in this dissertation, experimental and theoretical methods are used to investigate the transport and metabolism of glucose in the intervertebral disc. Strain-dependent and anisotropic (i.e., direction-dependent) transport of glucose in human annulus fibrosus (AF) was investigated using custom apparatuses. Results indicate that diffusivity and partitioning of glucose in human AF decreases with increasing compressive strain. Furthermore, diffusivity of glucose is anisotropic, being lower in the radial direction than the axial or circumferential directions at all strain levels. Transport of glucose in human AF was also found to diminish with increasing disc degeneration. A new method was developed to measure the rate of glucose consumption by IVD cells; this method was then validated with porcine AF and nucleus pulposus (NP) cells at varying levels of oxygen tension. Results show a positive Pasteur effect, with the glucose consumption rate by AF and NP cells increasing at low levels of oxygen. Moreover, results indicate that the rate of consumption of glucose by NP cells is significantly higher than that by AF cells. A new, three-dimensional finite element model of the IVD was developed in order to theoretically predict nutrient distributions in the disc. This model incorporated anatomical disc geometry, nutrient transport coupled to cellular metabolism, and mechanical loading conditions. The model was used to investigate the effects of endplate calcification and in vivo loading conditions on glucose distributions in the disc. Both calcification and compressive loading resulted in diminished glucose concentrations in the tissue. The model was also used to analyze the effects of degeneration and compression on cell viability in IVD by incorporating viability criteria. Our model could predict cell death in degenerated tissue, and compressive loading augmented this effect. The model prediction can be used to supplement experimental results, and may also serve as a useful tool in developing new strategies for the treatment of disc degeneration. The findings of this dissertation greatly enhance the knowledge of glucose transport and metabolism in the intervertebral disc. Given that glucose is a critical nutrient for disc cell survival, this knowledge can provide important insight into nutritional pathways and mechanisms in the IVD, as well as related disc degeneration.
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Walters, Rebecca. "Lumbar intervertebral disc infection pathology, prevention and treatment /". Click here to access, 2006. http://thesis.library.adelaide.edu.au/public/adt-SUA20061011.164644/index.html.
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Thesis (Ph.D.) -- University of Adelaide, School of Medical Sciences, Discipline of Pathology, 2006.Includes author's previously published papers. "March 2006" Includes bibliographical references. Also available in a print form.
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Hudgins, Robert Garryl. "Development and characterization of a prosthetic intervertebral disc". Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/20675.
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Pockert, Aneta Joanna. "Aggrecanolytic ADAMTS Expression in Human Intervertebral Disc Degeneration". Thesis, University of Manchester, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492880.
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Low Back Pain (LBP) affects 60-80% of the population at some point in their lives with approximately 10% of sufferers being chronically disabled. Degeneration of the intervertebral disc (DIVD) has been identified as one of the main causes of LBP.
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Chan, Chun-wai, i 陳春慧. "In-vitro study of the cryopreserved intervertebral disc". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41290380.
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Lim, Foon Lian. "Role of cadherin 2 in the intervertebral disc". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hdl.handle.net/10722/198869.
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Intervertebral disc (IVD) degeneration could lead to many serious complications including low back pain and disc herniation. However, the mechanism of disc degeneration is not fully understood, hindering the development of the therapeutics to cure this disease. The integrity of the nucleus pulposus (NP), which is derived from the notochord and situated in the core of the IVD, has long been implicated in the function and homeostasis of the IVD. Previous puncture-induced disc degeneration mouse model showed segregation of NP cell mass during the early stage of disc degeneration, indicating that an alteration in the cell adhesion molecule activities is involved in this process. By microarray analysis, our group have revealed specific expression of Cdh2 gene, encoding cadherin 2/N-cadherin, a subtype of cadherins in the NP cells, suggesting a regulatory role of cadherin 2 in the IVD. Cadherins are single transmembrane glycoproteins mediating calcium-dependent intercellular adhesions. Cadherin 2 is involved in chondrogenesis and skeletogenesis, suggesting that it is important in skeletal development and function.
This study hypothesized that cadherin 2 is required in the normal IVD development and homeostasis. The purposes of this project is firstly to fully characterize changes in cadherin 2 expression in the normal and degenerative discs in rodent and human, and secondly to examine the effect of loss of function of cadherin 2 on IVD homeostasis by functional blocking of the protein in the rodent NP and conditional knock out of cadherin 2 from the murine NP.
The rodent adult NP is similar to human fetal NP, where cadherin 2 is homogeneously expressed in the cell membranes of the notochordal (NC) cells, suggesting that cadherin 2 is a potential NC cell marker. The rodent degenerative NP is similar to human adult NP, where down-regulation of cadherin 2 is observed, the NC cells are replaced by small round cells, and the cell-cell contact is lost. Blocking cadherin 2 function in the rodent NP and conditional knock out of cadherin 2 in the notochord and consequently the NP will lead to transformation of NC cells into small cells, loss of cell-cell contact and a change in the extracellular matrix (ECM), suggesting that cadherin 2 is important in the maintenance of the phenotype and intercellular adhesion of the NC cells.
In conclusion, this study indicates that cadherin 2 is mainly expressed in the NC cells of the NP and serves as a potential NC cell marker. It plays a regulatory role in the IVD homeostasis through the maintenance of the NC cell phenotype by intercellular adhesions. This study contributes to the knowledge about the role of cadherin 2 in the disc homeostasis and the early mechanism of disc degeneration, and this would help in developing a therapeutic method to intervene or even reverse the disease process of disc degeneration.published_or_final_version
Orthopaedics and Traumatology
Doctoral
Doctor of Philosophy
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Palfrey, Rachel Melanie. "The anatomy and microcirculation of the intervertebral disc". Thesis, University of Exeter, 2013. http://hdl.handle.net/10871/16138.
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Low back pain is a costly financial and loss of productivity societal issue. Although its aetiology is unclear, it has been associated with the intervertebral disc and its degeneration which has been thought to be caused in part by poor nutrition. In this thesis the caudal disc of skeletally mature equines is utilised as an animal model. Techniques such as x-ray, light imaging, histology and magnetic resonance imaging were employed to investigate the vascular and structural anatomy of the disc and its surroundings and the uptake of tracers within the disc tissue. A detailed study of the anatomy revealed similarities with the human disc. The equine disc consists of two distinct structural areas; a nucleus and annulus. The surrounding vascularisation is similar; a main anteriorly positioned artery, the median caudal artery splits and encircles the centre of the vertebral body providing nutrition to the vertebral body. Smaller vessels anastomose over the surface of the vertebral body. Within the vertebral body the vessels end in capillary terminations at the edge of the vertebral cartilage endplate. As in humans these terminations were seen to vary along the endplate with shape and density; the capillaries are densest and larger in the area next to the nucleus. The cartilage endplate itself was found to have a variable width; of between 0.16 mm and 0.33 mm being widest at the nucleus. The annulus was seen to consist of lamellar rings which had high collagen content. A marked difference between equines and humans found was the number and width of lamellae present; equines were found to have on average 5 lamellae with a width range of 140 10 1110 microns. The shape of the discs was also found to be different with equines having almost circular coccygeal discs which have a concave superior and inferior surface. The nucleus of the disc, unlike current literature was found to have local order. An important contribution to knowledge which this thesis has made is data collected on diffusion time and partition coefficient on many regions within the disc. It was found that to reach equilibrium it took up to 22 hours in the outer anterior annulus but only 5 ½ hours in the central nucleus. Diffusion was found to be fastest with the neutral ring-shaped molecule Gadovist and slowest in the positive ion, manganese. Partition coefficients between the tracers were also found to vary. The highest partition coefficient was 6 in the central nucleus with manganese and the lowest was 0.5 with Magnevist at 0.5 in the nucleus area. This information will be useful in aiding drug delivery clinically and performing contrast enhanced imaging for pathology detection.
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Chan, Chun-wai. "In-vitro study of the cryopreserved intervertebral disc". Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41290380.
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Moore, Robert James. "Vascularization of the intervertebral disc in pathological conditions /". Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phm8233.pdf.
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Wang, Shaobai. "In vivo lumbar spine biomechanics : vertebral kinematics, intervertebral disc deformation, and disc loads". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/70430.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references.
Knowledge of lumbar spine biomechanics in living human subjects is fundamental for understanding mechanisms of spinal injury and pathology, for improvement of corresponding clinical treatments, and for design of spinal prosthesis. However, due to the complicated spine anatomy and loading conditions as well as high risks in these direct measurements, it has been a challenge to determine the in vivo biomechanics of the lumbar spine. To address this problem, the overall objective of this thesis was to develop and implement a dual fluoroscopic imaging system to non-invasively study human lumbar spine biomechanics. In line with this objective, the first goal was to quantify the ability of the dual fluoroscopic imaging system to determine vertebral kinematics. The second goal was to implement this technique to investigate spinal motion in both healthy subjects and patients with pathology. The third goal was to explore the feasibility of using kinematic data obtained from this system as boundary conditions in finite element analysis to calculate the physiological loads on the intervertebral disc. The system was shown to be accurate and repeatable in determining the vertebral kinematics in all degrees of freedom. For the first time, six degree-of-freedom motion of different structures of the spine, such as the vertebral body, intervertebral disc, facet joint and spinous process were measured in vivo in both healthy subjects and subjects with pathology during functional activities. In general, the group of subjects with pathology showed a significantly abnormal kinematic response during various physiological functional activities. Preliminary studies have shown the applicability and high accuracy of finite element modeling to calculate disc loads using in vivo vertebral kinematics as displacement boundary conditions.
by Shaobai Wang.
Ph.D.
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Chokhandre, Snehal K. "A Biomechanical Comparison Between a Biological Intervertebral Disc and Synthetic Intervertebral Disc Implants Under Complex Loading: An In Vitro Study". University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1187022568.
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Jim, Jin-to, i 詹展韜. "Genetics and molecular characterization of degenerative disc disease". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B35720189.
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Baumhardt, Raquel. "TRATAMENTO CLÍNICO DE CÃES COM DIAGNÓSTICO PRESUNTIVO DE DOENÇA DO DISCO INTERVERTEBRAL". Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/10201.
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Conselho Nacional de Desenvolvimento Científico e TecnológicoIntervertebral disc disease (IVD) is a common pathology in clinical neurology of dogs, representing 45.8% of neurological cases treated at Veterinary Hospital of the Universidade Federal de Santa Maria. The most affected segments are the thoracolumbar (T3-L3) and cranial cervical (C1-C5) of the spinal cord. The clinical sign occurs due a combination of the compressive effect of the disc material and the injury of impact on spinal cord, probably due to an extrusion. A clinical sign varies according to the affected segment of the spinal cord and the severity of the injury. It could be presented only by spinal hyperesthesia, whereas more severe injuries can lead to tetra / paraplegia with no nociception (deep pain) caudal to the lesion. Clinical management for IVD is generally indicated for dogs with hyperesthesia with or without minimal neurological deficits and consists of absolute rest in cage between four to six weeks. Surgery is the treatment of choice for dogs with severe neurological deficits (not ambulatory tetraparesis, tetraplegia, paraplegia with or without nociception in less than 48 hours) in dogs with unsuccessful of clinical management, or dog that have recurrence of disease. In contrast to the numerous studies evaluating the efficacy of surgical treatment in dogs with thoracolumbar and cervical IVD, studies demonstrating the effectiveness of conservative treatment are rare. The aim of this study was to identify dogs with presumptive diagnosis of thoracolumbar and cervical IVD who underwent clinical management and evaluate the response to therapy; and to analyze the effect of age, gender, duration of clinical signs, neurological degree and therapy, as prognostic factors in clinical outcome of the patient. Five hundred six neurological records were used to identify affected dogs (n = 379 thoracolumbar; n = 127 cervical), and was selected those patients with presumptive diagnosis of IVD submitted to clinical management as a first option. The outcome was satisfactory in 73.3% of cases of thoracolumbar IVD, and 92.7% of cases of cervical IVD, demonstrating that clinical management (cage rest, anti-inflammatory and analgesic opioid administration) is effective, especially in milder disease. Conservative treatment has a substantial rate of recurrence and neurological signs may be more severe than the first clinical presentation. The gender, age and duration of clinical signs has no prognostic effect on clinical outcomes of patients IVD of thoracolumbar and cervical, in the sample of the study.
A doença do disco intervertebral (DDIV) é uma afecção frequente na clínica neurológica de cães, representando 45,8% dos casos neurológicos atendidos pelo Serviço de Neurologia do Hospital Veterinário Universitário da Universidade Federal de Santa Maria. Os locais mais acometidos pela doença são os segmentos toracolombar (T3-L3) e cervical cranial (C1-C5) da medula espinhal. A manifestação clínica ocorre devido a uma combinação do efeito compressivo do material de disco e da lesão de impacto na medula espinhal, decorrente principalmente da extrusão do disco e varia de acordo com o segmento da medula espinhal afetado e da severidade da lesão. Pode ser evidenciada apenas por hiperestesia espinhal, enquanto as lesões mais graves podem levar a tetra/paraplegia com ausência da nocicepção (dor profunda) caudal a lesão. O tratamento clínico para DDIV geralmente é indicado para cães com hiperpatia associada ou não a mínimas deficiências neurológicas e consiste em repouso absoluto em gaiola entre quatro a seis semanas. Já a cirurgia é o tratamento de eleição para cães com deficiências neurológicas graves (tetraparesia não ambulatória, tetraplegia, paraplegia com ou sem nocicepção em menos de 48 horas), em cães refratários ao tratamento clínico, ou que apresentem recidiva da doença. Em contraste com os inúmeros estudos avaliando a eficácia do tratamento cirúrgico em cães com DDIV toracolombar e cervical, estudos demonstrando a eficácia do tratamento conservativo são escassos na literatura. Diante desses fatores, o objetivo desse estudo foi identificar cães com diagnóstico presuntivo de DDIV toracolombar e cervical que foram submetidos ao tratamento clínico e avaliar a resposta à terapia instituída; além de avaliar a relação da idade, do gênero, da duração dos sinais clínicos e do tratamento de acordo com o grau neurológico como fatores prognósticos na evolução clínica desses pacientes. Foram analisados 506 registros neurológicos (n=379 toracolombar; n=127 cervical), e selecionados aqueles pacientes com diagnóstico presuntivo de DDIV submetidos ao tratamento clínico como primeira opção. A evolução clínica foi satisfatória em 73,3% dos casos de DDIV toracolombar, e 92,7% dos casos de DDIV cervical, demonstrando que o tratamento clínico com repouso absoluto, administração de anti-inflamatórios e analgésicos opióides é efetivo, principalmente em graus mais leves da doença. O tratamento conservativo apresenta um índice considerável de recidiva, cujos sinais neurológicos poderão ser mais graves do que a primeira apresentação clínica. O gênero, a idade e a duração dos sinais clínicos não apresentam efeito prognóstico na evolução clínica dos pacientes de DDIV toracolombar e cervical, na amostra estudada.
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Travascio, Francesco. "Modeling Molecular Transport and Binding Interactions in Intervertebral Disc". Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_dissertations/322.
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Low back pain represents a significant concern in the United States, with 70% of individuals experiencing symptoms at some point in their lifetime. Although the specific cause of low back pain remains unclear, symptoms have been strongly associated with degeneration of the intervertebral disc. Insufficient nutritional supply to the disc is believed to be a major mechanism for tissue degeneration. Understanding nutrients' transport in intervertebral disc is crucial to elucidate the mechanisms of disc degeneration, and to develop strategies for tissue repair (in vivo), and tissue engineering (in vitro). Transport in intervertebral disc is complex and involves a series of electromechanical, chemical and biological coupled events. Despite of the large amount of studies performed in the past, transport phenomena in the disc are still poorly understood. This is partly due to the limited number of available experimental techniques for investigating transport properties, and the paucity of theoretical or numerical methods for systematically predicting the mechanisms of solute transport in intervertebral disc. In this dissertation, a theoretical and experimental approach was taken in order to investigate the mechanisms of solute transport and binding interactions in intervertebral disc. New imaging techniques were developed for the experimental determination of diffusive and binding parameters in biological tissues. The techniques are based on the principle of fluorescence recovery after photobleaching, and allow the determination of the anisotropic diffusion tensor, and the rates of binding and unbinding of a solute to the extracellular matrix of a biological tissue. When applied to the characterization of transport properties of intervertebral disc, these methods allowed the establishment of a relationship between solute anisotropic and inhomogeneous diffusivity and the unique morphology of human lumbar annulus fibrosus. A mixture theory for charged hydrated soft tissues was presented as a framework for theoretical investigations on solute transport and binding interactions in cartilaginous tissues. Based on this theoretical framework and on experimental observations, a finite element model was developed to predict solute diffusive-convective-reactive transport in cartilaginous tissues. The numerical model was applied to simulate the effect of mechanical loading on solute transport and binding interactions in cartilage explants and intervertebral disc.
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Antoniou, John. "Quantitative biochemical changes in the human lumbar intervertebral disc". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0028/NQ50103.pdf.
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Vignollet, Julien. "Computational strategies toward the modelling of the intervertebral disc". Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3774/.
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Lumbar back pain has considerable socio-economical impacts, motivating a recently increasing interest from the research community. Yet, mechanisms triggering pain are not fully understood and this considerably hinders the development of efficient treatments and therapies. The objective of this thesis is to participate to the general understanding of the biomechanics of the spine through the development of computational strategies for the intervertebral disc. The intervertebral disc is a complex structure mainly comprised of the nucleus pulposus and the annulus fibrosus. The nucleus pulposus is the gelatinous core of the disc, which consists of a charged and hydrated extra-cellular matrix and an ionised interstitial fluid. It is enclosed in the annulus fibrosus which is formed by concentric layers of aligned collagen fibre sheets, oriented in an alternating fashion. A biphasic swelling model has been derived using mixture theory for soft, hydrated and charged tissues in order to capture the salient characteristics of the disc's behaviour. The model fully couples the solid matrix under finite deformations with the ionised interstitial fluid. The nucleus is assumed to behave isotropically while the effects of the collagen fibres in the annulus fibrosus are accounted for with a transversely isotropic model. The fixed negative charges of the proteoglycans, which induce an osmotic pressure responsible for the swelling capabilities of the disc, are constitutively modelled under the simplifying Lanir hypothesis. A Newton-Raphson solver was specifically built to solve the resulting nonlinear system of equations, together with a verification procedure to ensure successful implementation of the code. This was first reduced to the one dimensional case in order to demonstrate the appropriateness of the biphasic swelling model. The three dimensional model exhibited numerical instabilities, manifesting in the form of non-physical oscillations in the pressure field near boundaries, when loads and free-draining boundary conditions are simultaneously applied. As an alternative to considerable mesh refinement, these spurious instabilities have been addressed using a Galerkin Least-Square formulation, which has been extended for finite deformations. The performance and limitations of the GLS framework, which drastically reduces the pressure discrepancies and prevents the oscillations from propagating through the continuum, are demonstrated on numerical examples. Finally, the current state of the model's development is assessed, and recommendations for further improvements are proposed.
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Ho, Grace, i 何秀慧. "Intervertebral disc regeneration by use of autologous mesenchymal stemcells". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B31541616.
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Lam, To-kam, i 林吐金. "Fate of notochord descendent cells in the intervertebral disc". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B50567160.
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Alexander, Lyndsay Ann. "The effect of position on the lumbar intervertebral disc". Thesis, Robert Gordon University, 2014. http://hdl.handle.net/10059/1020.
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This thesis comprises three phases with a combined aim which was to investigate the effect of position on the lumbar intervertebral disc (IVD). The effect of position on the lumbar IVD in asymptomatic subjects and subjects with discogenic low back pain (DLBP) was explored using positional Magnetic Resonance Imaging (pMRI). Convenience samples of 11 asymptomatic and 34 DLBP subjects were recruited to have sagittal and axial pMRI scans performed in sitting (Neutral, Flexed and Extended), standing and lying (Supine and Prone extension) positions. The sagittal plane migration of the nucleus pulposus (NP) of each lumbar IVD in each position was measured from the sagittal and axial pMRI scans. Within and between group inferential analysis was performed using nonparametric tests. Both the asymptomatic and DLBP subjects’ demonstrated that position had statistically significant effects on the sagittal plane NP migration. Both groups demonstrated significantly greater posterior sagittal plane NP migration in Neutral and Flexed sitting positions compared to the other positions. However, between group comparisons identified that the asymptomatic subjects also demonstrated significantly greater posterior sagittal plane NP migration than the DLBP subjects. This pattern was more common in the upper lumbar IVDs (L1/2 and L2/3) between positions and less common in the lower IVDs (L4/5 and L5/S1) between positions. New knowledge regarding the behaviour of the lumbar IVD emerged from this research. The differences detected between the asymptomatic and DLBP subjects suggest that some current theories regarding DLBP may be incorrect. The results also support imaging of DLBP subjects in sitting positions as opposed to current supine positions. Although the limitations of the study reduce generalisation of the results, the implications for clinical practice, imaging and suggestions for further research from this work are important to improve understanding and conservative management of DLBP.
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Lee, Tsz Yan Juliana. "Technique and method development for intervertebral disc (IVD) research". Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/43799.
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Intervertebral disc (IVD) degeneration is one of the major causes of low back pain. The direct and indirect cost of managing back pain posts heavy socioeconomic burden to the society. Improved technologies and techniques together with well documented experiments will benefit the research field by saving effort in doing the optimization in every laboratory and avoiding experiment failure due to incomplete understanding of the procedures. These can accelerate scientific discovery, reduce the sacrifice of animals and enable a more effective use of funding. Nucleus pulposus (NP) is the central part of IVD. Differences in matrix compositions in human NP clinical samples demand different cell isolation protocols for optimal results but there is no clear guide about this to date. Sub-optimal protocols may result in low cell yield, limited reliability of results or even failure of experiments. We experimented different isolation protocols to study different parameters involved and suggested some rules for cell isolation in three main applications: RNA extraction for phenotyping, cell isolation for cell culture, and characterization by flow cytometry. In addition, instead of extracting RNA from isolated cells, extraction of RNA from tissues directly may avoid the change of RNA levels during the cell isolation process. However, extraction of RNA directly from human and large animal IVD tissue is technically challenging due to its tough nature, low cell-to-matrix ratio and high proteoglycan content. Thus we developed a method for RNA extraction from bovine disc tissues by integrating the use of cryosectioning, additional phase separation and high salt precipitation into conventional guanidinium thiocyanate based method. With this method, RNA could be extracted from the NP tissue directly but the concentration was low. A shift toward 270 nm was observed in its UV spectrum which was due to phenol contamination. This caused an overestimation of RNA concentration. Hence we developed a computational method based on UV spectra for correcting the overestimated concentrations of RNA contaminated with phenol. The accuracy of concentration increased substantially with the use of the correction formula. Mesenchymal stem cells (MSCs) have great potential in IVD engineering and hence we studied the isolation and culturing of MSCs from different sources. Effect of cell shape was reported for MSCs but not for NP cells. Micropatterning can be used to pattern cells into different shapes and arrangements. Therefore, we optimized the preparation of bovine NP cell micropatterns and also investigated the preparation of cell micropatterns for confocal microscopy. Besides, we developed methods to study the gene expression of cells on patterns by RT-qPCR with and without prior selection of cells of interest by laser capture microdissection (LCM). In short, different methods related to IVD research were developed and optimized. With improved methods together with a better understanding of the underlying rationale, researchers can save time and cost in their experiments and reduce experiment failure rate. This will help to accelerate researches. New methods also enable studies which were not feasible in the past.
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Wan, Simon. "Self-assembling peptide hydrogel for intervertebral disc tissue engineering". Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/selfassembling-peptide-hydrogel-for-intervertebral-disc-tissue-engineering(1f931e1e-6b9b-49a7-bd30-2572ff0338fa).html.
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The intervertebral disc (IVD), situated between adjoining vertebrae, consists of the gelatinous nucleus pulposus (NP) in the centre surrounded by the tougher annulus fibrosus (AF). Its main roles are to distribute loads and to act as joints. With aging, degenerative disc disease (DDD) occurs due to an imbalance in anabolic and catabolic events in the IVD, which results in a loss of function. Lower back pain (LBP) affects 84% of people at some point in their lifetime and is strongly associated with DDD. Current LBP treatments have limited long term efficacy and are symptomatic rather than curative. Cell-based therapies are regarded to hold great potential for the treatment of DDD as it has been hypothesised that they could regenerate the damaged tissue and alleviate LBP. A number of natural and synthetic biomaterials have been investigated as NP tissue engineering scaffolds with varying results. In this study, a self assembling peptide hydrogel (SAPH) was investigated for its potential as a cell carrier and/or scaffold for NP tissue engineering. SAPHs display the advantages of natural polymer hydrogels such as biocompatibility and biodegradability whilst combining the advantages of synthetic materials such as controlled structural and mechanical propertiesCharacterisation determined that the SAPH nanofibrous architecture had features that were of similar scale to extracellular matrix (ECM) components of the human NP. The mechanical properties of the SAPH could be optimised to closely match the native tissue. The system could shear thin and self-heal making the system ideally suited to delivery via minimally invasive procedure. The three dimensional (3D) culture of bovine NP cells (bNPCs) in the SAPH demonstrated that the NP phenotype could be restored after de-differentiation during monolayer culture. Gene expression results demonstrated that ‘traditional’ and ‘novel’ NP markers were highly expressed throughout in vitro culture. Cell viability was high, cell population remained stable and bNPCs adopted the characteristic rounded morphology of native NPCs. Finally, type II collagen and aggrecan, the main ECM components of the NP, were deposited with increasing production over culture period. Growth differentiation factor 6 (GDF-6) has been identified as the most promising current growth factor for inducing discogenic differentiation from human bone marrow mesenchymal stem cell (h-BMMSCs). After samples were stimulated with GDF-6, gene expression results confirmed that a NP-like phenotype could be induced with high expression of ‘traditional’ and ‘novel’ NP markers. Cell viability was high, cell population remained stable and NP associated ECM components were deposited with cells displaying a rounded morphology. Interestingly, when h-BMMSCs were cultured without GDF-6, it was strongly suggested that spontaneous discogenic differentiation occurred after culture in the SAPHs as ‘traditional’ and ‘novel’ NP markers were highly expressed, morphology was comparable to native NPCs and type II collagen and aggrecan were deposited extracellularly. If these findings were accurate then this is the first study to demonstrate that a NP-like phenotype could be induced from MSCs without use of an exogenous growth factor or a discogenic bioactive motif. Despite exciting and novel results, further work is required to confirm the potential of SAPHs for NP tissue engineering scaffolds.
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Ross, Edward R. S. "Stiffness : a key mechanical factor in normal, degenerate and artificial lumbar intervertebral discs". Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/3213.
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This thesis describes the development of artificial disc technology for the replacement of intervertebral discs in the human lumbar spine. The clinical problem is back pain. There may be a relationship between certain forms of back pain and disc degeneration. The mechanical properties of human intervertebral discs are examined in detail. The genetic basis of disc degeneration is presented. The hypothesis is that such degeneration leads to a loss of normal stiffness in the segments affected leading to abnormal mechanical behaviour which in turn leads to pain. The evidence for this is presented. The development of surgical solutions to relieve back pain, from fusion through first generation mechanical artificial discs to elastomeric designs, is traced. The author‘s personal contributions to this area of knowledge are set out. The appreciation of the requirement for a restoration of physiological stiffness is argued throughout, showing where fusion and first generation discs have not met the clinical aim of pain relief, because they have not restored physiological stiffness. The path to an elastomeric, viscoelastic, polyhydrocarbon, rubber solution in the form of the “Freedom“ disc has filled 17 years of the author‘s academic pursuits. It will be shown that this technology may represent a possible solution to the clinical problem. Failure is part of all new advancement and this too is presented, to show how that has influenced thinking, producing original ideas to overcome these failures. Providing lessons are learned from these failures then our patients in the future will benefit.
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Baptista, Josemberg da Silva. "Análise do envelhecimento e degeneração de discos intervertebrais humanos cervicais e lombares". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-07022014-142752/.
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INTRODUÇÃO: A degeneração do disco intervertebral (DIV) é um processo crônico e apontado como o maior causador de cervicalgia e lombalgia. Esse processo geralmente conta com a degradação da matriz extracelular, expressão de citocinas inflamatórias e fatores angiogênicos e axonogênicos. Entretanto, muito pouco se sabe sobre esse processo em DIVs assintomáticos durante o envelhecimento, principalmente no segmento cervical. O objetivo desse estudo foi de delinear o perfil de moléculas relacionadas à degeneração discal em DIVs cervicais e lombares. MÉTODOS: Discos intervertebrais humanos cervicais e lombares (C4-C6 e L4-S1) foram coletados em autópsia de 30 indivíduos presumivelmente assintomáticos e divididos em grupos jovem (GJ < 35 anos, n=60) e idoso (GI > 65 anos, n=60). O nível de degeneração foi constatado pela escala de Thompson, e foi correlacionado com a detecção imuno-histoquímica das moléculas de MMP-1, -2, -3, TIMP-1, IL-1beta, TNF-alfa, VEGF, NGF-beta e BDNF. RESULTADOS: Todos os DIVs mostraram algum grau de degeneração, embora mais acentuadas no GI. As moléculas empenhadas no estudo foram identificadas em ambos grupos. A detecção imuno-histoquímica foi prevalente no citoplasma das células nativas do DIV e na região de interseção entre a placa vertebral e o arranjo fibro-colágeno. O envelhecimento propiciou, no disco cervical, maior expressão de MMP-2, -3, VEGF, NGF-beta e BDNF, enquanto que no disco lombar, a maior expressão foi de MMP-1, -2 -3, TIMP-1, TNF-alfa, VEGF e NGF-beta. DISCUSSÃO: O envelhecimento de DIVs cervicais e lombares caracterizou-se por exibir um processo catabólico e extensivo remodelamento da matriz extracelular, os quais podem ser interpretados como eventos que antecipam a doença degenerativa discal. Esse processo é capaz de levar a angiogênese e axonogênese de modo a ampliar o metabolismo aeróbio do DIV e captar informação nociceptiva como forma de defesa, uma vez que até nos discos lombares de indivíduos jovens essa última característica pôde ser observada. Discos assintomáticos também exibem moléculas relacionadas à doença degenerativa discal e talvez a inibição de parte dessas possa resultar em terapia preventivaINTRODUCTION: Degeneration of the intervertebral disc (DIV) is a chronic process that pointed as a major cause of neck and low back pain. This process generally includes an extracellular matrix degradation, expression of inflammatory cytokines, angiogenesis and axonogenesis factors. However, there is a little known about this process in asymptomatic DIVs during aging, especially in the cervical region. The aim of this study was to delineate the profile of molecules related to disc degeneration in the cervical and lumbar discs. METHODS: Human cervical and lumbar intervertebral discs (C4-C6 e L4-S1) were harvested at autopsy from 30 asymptomatic individuals, and divided according to age with young (GJ < 35 years old, n=60) and elderly (GI > 65 years old, n=60) groups. Gross degeneration was graded according to the Thompson scale and this was correlated to the immunohistochemical detection of molecules of MMP-1, -2, -3, TIMP-1, IL-1beta, TNF-alfa, VEGF, NGF-beta e BDNF. RESULTS: Discs from GJ were significantly less degenerated than those of GI. The molecules involved in the study were identified in both groups. The immunohistochemical detection was prevalent in the cytoplasm of native disc cells and the region between the vertebral plate and fibrous collagen arrangement (intersection). Aging provided in cervical disc, increased expression of MMP-2, -3, VEGF, NGF and BDNF-beta, whereas in the lumbar disc the highest expression of MMP-1, -2, -3, TIMP-1, TNF-alfa, VEGF and NGF-beta was seen. DISCUSSION: The aging of cervical and lumbar DIV was marked by catabolic process and a extensive remodeling on extracellular matrix which can be interpreted as a predict event of the degenerative disc disease. This process can lead to angiogenesis and axonogenesis in order to expand the aerobic metabolism of the DIV and get nociceptive information as a defense, since even in the lumbar discs of young individuals this last feature can be observed. Asymptomatic discs also exhibit molecules related to degenerative disc disease and perhaps the inhibition some of these can result in preventive therapy
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Ho, Wai-hung Daniel, i 何偉雄. "Genetic study of lumber disc degeneration". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42841215.
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Hoschouer, Clifford Jason. "Material Analysis of the Intervertebral Disc and the use of Flexible Bodies in Disc Modeling". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1321974899.
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Casa, Nara Lígia Leão. "Associação entre polimorfismos na região VNTR do gene aggrecan e a hérnia de disco lombar". Universidade Federal de Goiás, 2015. http://repositorio.bc.ufg.br/tede/handle/tede/6830.
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Introduction: Lumbar disc herniation (LDH) is the most common diagnosis among the degenerative changes in the lumbar spine and it can lead to functional limitations. Although several studies have shown a positive association between polymorphisms in the aggrecan gene and LDH, results are conflicting and vary across populations. Until now, such studies have not been carried out in Brazil. An understanding of this association can help in the prevention and intervention processes in patients with LDH. Objective: Investigate the association between polymorphisms in the aggrecan gene and LDH. Methods: This is a Case-Control study, paired by gender and age. A total of 119 male and female individuals from Goiania (Brazil) participated in the study; 39 individuals in the Case Group (CaG) and 80 in the Control Group (CtG). For each individual, sociodemographic and clinical data were collected as well as blood samples for genetic analysis. DNA was isolated and genotyped at the variable number of tandem repeats (VNTR) region of the aggrecan gene using polymerase chain reaction. Results: Both groups were homogeneous for socio-demographic, anthropometric, and life style variables. The sum of allele sizes at the VNTR region of the aggrecan gene were significantly lower in individuals with LDH, with allele A22 showing significantly higher frequency in this group. Comparison of allele size distribution indicated that shorter alleles (i.e., A13-A25) were more frequent in individuals with LDH, whereas alleles with a higher number of repeats were more frequent among healthy individuals. It should be noted, however, that differences were not significant. The most frequent alleles in both groups were A28, A27 and A29, respectively. Genotype A26/A26 was the most common among individuals in the CaG. Conclusions: An association between short alleles and LDH was observed in this study. This finding is in agreement with other reports in the literature, corroborating the hypothesis that individuals with shorter alleles have an aggrecan gene with fewer repeats. Therefore, a smaller number of chondroitin sulfate chains bind to the aggrecan in the intervertebral disc, leading to a decrease in its physiological function of hydration of the intervertebral disc, and thus to an increase in LDH susceptibility.
Introdução: A hérnia de disco lombar (HDL) é um diagnóstico frequente dentre as alterações degenerativas da coluna lombar e causa limitações funcionais importantes. Alguns estudos apontam para uma associação positiva entre polimorfismos no gene aggrecan e a HDL, porém os resultados ainda são conflitantes e variam entre as populações, não havendo pesquisas sobre o tema na população brasileira até o momento. Compreender essa associação pode auxiliar na prevenção e intervenção junto às pessoas com HDL. Objetivo: Investigar a associação entre polimorfismos no gene aggrecan com a hérnia de disco lombar. Métodos: Estudo caso-controle, pareado em quinquênio por idade e sexo. Participaram do estudo 119 pessoas de ambos os sexos, domiciliadas em Goiânia (Brasil), sendo 39 no Grupo Caso (Ca) e 80 no Controle (Ct). Foram coletados dados sociodemográficos e clínicos e amostras de sangue periférico; o DNA foi isolado para posterior genotipagem do número variável de repetições em Tandem (VNTR) do gene aggrecan (ACAN) através de PCR convencional. Resultados: Os grupos mostraram-se homogêneos quanto às variáveis sociodemográficas, antropométricas e hábitos de vida. O escore alélico do VNTR do gene aggrecan foi significativamente menor nos voluntários com HDL; o alelo A22 mostrou-se significativamente mais prevalente nesse mesmo grupo; no grupo Ca houve maior frequência dos alelos pequenos A13 - A25, enquanto no Ct maior frequência dos alelos grandes, porém, sem diferença estatisticamente significativa; em ambos os grupos os alelos mais frequentes foram A28, A27 e A29, respectivamente; o genótipo A26/A26 foi significativamente mais comum no Grupo Ca. Conclusões: Houve associação entre alelos pequenos com a HDL nos adultos pesquisados e compatibilidade com a literatura internacional, corroborando a hipótese de que indivíduos que possuem alelos pequenos possuem um aggrecan com menor número de repetições. Portanto, um número menor de cadeias de sulfato de condroitina se ligam no aggrecan do disco intervertebral, o que resulta na diminuição da sua função fisiológica de hidratação do disco e, consequentemente, aumenta a susceptibilidade individual à HDL.
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Ho, Grace. "Intervertebral disc regeneration by use of autologous mesenchymal stem cells". Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B31541616.
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Fernando, Hanan Nirosha. "Mechanical Loading Affects the Energy Metabolism of Intervertebral Disc Cells". Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_theses/286.
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Back pain is the second most common neurological ailment in the United States and the leading cause of pain and disability. More than 80% of the total US population experiences back-pain during their life time and the annual back pain related healthcare costs exceed 100 billion dollars. While the exact cause of low back pain (LBP) is still unknown, degeneration of the intervertebral disc (IVD) has been suggested as a primary contributor. IVD is the largest avascular tissue in the human body and it is composed of three integrated tissues (annulus fibrosus - AF, nucleus pulposus - NP and cartilaginous end plate - CEP). IVD functions as a shock-absorber during motion and provides flexibility to motion of the spine. Maintaining IVD tissue integrity is an energy demanding process. Studies have shown that mechanical loading affects cellular biosynthesis of IVD tissue and may also promote IVD degeneration. However the path to this effect is still unknown. We propose a link between mechanical loading and cell energy production which contributes to altered cellular biosynthesis. Thus, we investigated the effects of mechanical loading on IVD cell energy metabolism under various mechanical loading regimes. Porcine AF and NP cells were isolated and seeded in 2% agarose at a 5,000,000 cells/mL cell density. A custom made bioreactor was used to conduct compression experiments. The experiment groups were: 15% static compression; 30% static compression; 0.1, 1 and 2 Hz dynamic compression at 15% strain magnitude. Experiment duration was 4 hr. ATP concentration in cell-agarose construct and culture media were measured using Luciferin-luciferase method to evaluate ATP production and ATP release from cells respectively. Lactate concentration in media was measured using lactate dehydrogenase enzymatic assay. Nitrite (stable metabolite of nitric oxide - NO) concentration in media was measured by Greiss Assay. DNA content per sample was measured using fluorometric assay. DNA content per sample was used as an internal control; all compressed samples were then normalized to unstrained control group. ATP production of AF cells was up regulated by static and dynamic mechanical loading. Data suggests that AF cell response to mechanical loading is primarily loading amplitude dependent. NP cells exhibited an increased ATP production at 1 Hz dynamic loading but remained comparable to control samples at other tested conditions. AF cells produced an increase in NO production at 1-, 2 Hz dynamic loading. NO production of NP cells was up regulated by mechanical loading at all tested conditions. ATP release was up regulated at higher frequencies in AF cells. In addition to higher frequencies (1 Hz and 2 Hz) NP cell ATP release was also up regulated by 30% static compression. Thus, this study clearly illustrates that mechanical loading affects IVD cell energy production.
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Houben, Gerard Boudewijn. "Swelling and compression of intervertebral disc tissue model and experiment /". [Maastricht : Maastricht : Universiteit Maastricht] ; University Library, Maastricht University [Host], 1996. http://arno.unimaas.nl/show.cgi?fid=6705.
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Dimitri, Helene Karen. "The influence of compensation on recovery following intervertebral disc surgery /". Title page, contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09HS/09hsd5826.pdf.
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