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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Insights para simplificação de terapia celular na lesão de nervo isquiático em camundongos / Cell therapy on sciatic nerve injury: insights on simplification

Nicolielo, Renato Luiz Cursino, 1971- 24 August 2018 (has links)
Orientador: Marcus Alexandre Finzi Corat / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T17:01:17Z (GMT). No. of bitstreams: 1 Nicolielo_RenatoLuizCursino_D.pdf: 3694566 bytes, checksum: 9d48540bdf4e330a06198c2b7816ad32 (MD5) Previous issue date: 2014 / Resumo: As lesões traumáticas de nervos periféricos têm sido objeto de numerosos estudos que tentam compreender os processos de reparação pós-lesão. Apesar dos avanços nas técnicas cirúrgicas, os resultados funcionais têm sido bastante decepcionantes, ao que se refere ao intervalo de tempo entre lesão e tratamento. Para tratamento rápido e eficaz de lesões nervosas, a terapia celular torna-se uma possibilidade no aumento do sucesso de reparo do nervo. Propõe-se então avaliar a eficácia da terapia celular, sobre os níveis de melhora funcional dos camundongos com o nervo isquiático lesionado e tratado com células progenitoras GFP da medula óssea em comparação com seus controles. No presente trabalho utilizou-se camundongos C57BL/6-HETGFP/J/Unib geneticamente modificados como doadores de células progenitoras GFP ("green fluoresent protein") da medula óssea que foram usadas no tratamento via sistêmica em camundongos C57BL/6/J/Unib não marcados com GFP submetidos a esmagamento do nervo isquiático. Estes animais foram analisados quanto sua performance funcional, migração celular, imunohistoquímica de proteínas p75NTR e neurofilamento e contagem axonal em imagens de microscopia eletrônica. Através dos resultados obtidos verificou-se que houve uma significativa melhora funcional do grupo tratado de 224,9% quando comparado com o grupo controle, principalmente no início do processo de recuperação. Estes valores de melhora funcional coincidiram com a grande quantidade de células GFP, maior quantidade de axônios mielinizados e menor quantidade de axônios degeneradas encontradas no sitio da lesão, além do aumento de imunorreatividade da proteína p75NTR, envolvida no processo de regeneração nervosa. Tudo isto vem a demonstrar a eficiência da terapia celular utilizada com células progenitoras da medula óssea, com uma purificação não especifica, tornando-a viável para uma terapia celular sistêmica rápida, simples e eficaz sendo assim uma possibilidade terapêutica para lesões de nervo / Abstract: Traumatic injuries of peripheral nerves have been the subject of numerous studies that attempt to understand the processes of repair after injury. Despite advances in surgical techniques, the functional results have been very disappointing to depend on the time interval between injury and treatment. For fast and effective treatment of nerve lesions, cell therapy becomes a possibility in increasing the success of nerve repair. So it is proposed to evaluate the efficacy of cell therapy on levels of functional improvement of mice with injured ischiatic nerve and treated with GFP progenitor cells of bone marrow as compared with their controls. In this study we used mices C57BL/6-HETGFP/J/Unib genetically modified as donors of stem cells GFP ("green fluoresent protein") of bone marrow that were used in the treatment via systemic of mice C57BL/6/J/Unib not marked with GFP underwent sciatic nerve crush. These animals were analyzed for their functional performance, cell migration, immunohistochemistry of p75NTR protein and neurofilament and axonal counts in electron microscope images. From the results obtained it was verified that there was a significant functional improvement in the treated group 224.9% when compared with the control group, mainly at the start of the recovery process. These values of functional improvement have coincided with the large amount of GFP cells, largest amount of myelinated axons and smallest amount of degenerate axons found at the site of injury axons, in addition to the increase of immunoreactivity of the protein of p75NTR involved in nerve regeneration process. All this is to demonstrate the efficiency of cell therapy used in bone marrow progenitor cells with a non-specific purification, making it feasible for a quick, simple and effective systemic cell therapy becoming this way a therapeutic possibility for nerve injured / Doutorado / Clinica Medica / Doutor em Clínica Médica
22

Functional and histomorphometric evaluation of median nerve lesion in wistar rats treated with GM1 = Avaliação funcional e histomorfométrica da lesão de nervo mediano em ratos wistar tratados com GM1 / Avaliação funcional e histomorfométrica da lesão de nervo mediano em ratos wistar tratados com GM1

Oliveira Filho, Osvaldo Mendes de, 1964- 26 August 2018 (has links)
Orientador: William Dias Belangero / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T07:47:22Z (GMT). No. of bitstreams: 1 OliveiraFilho_OsvaldoMendesde_D.pdf: 2509545 bytes, checksum: 6effb16e1eedd8b6d33c41daea640b76 (MD5) Previous issue date: 2014 / Resumo: O objetivo deste trabalho foi comparar através da avaliação funcional pelo grasping test e análise histomorfométrica o tratamento da lesão do nervo mediano em ratos de linhagem Wistar através da microneurorrafia tradicional com a microneurorrafia associada à administração do monossialogangliosídeo (GM1) e avaliar especificamente se o GM1 melhora a regeneração axonal do nervo mediano e a função da musculatura por ele inervado. Material e Método: Foram empregados 32 ratos machos de linhagem Wistar. Destes, foram selecionados aleatoriamente 10 animais, grupo 0, para obtenção da força de preensão média em ratos normais, antes do procedimento cirúrgico. Esses animais foram reintegrados aos grupos. Foram criados o grupo I, com 10 animais, em que foi feita ressecção de 5 mm do nervo mediano do membro anterior direito e não foi submetido a nenhum tratamento. Nos outros grupos foi produzida uma lesão transversa do nervo mediano proximalmente ao epicôndilo medial criando-se os grupos II, tratados com microneurorrafia epineural externa e o grupo III, tratado com a microneurorrafia epineural externa associada à administração intraperitoneal de GM1. A cirurgia foi realizada imediatamente após a lesão e a técnica utilizada foi a sutura término-terminal. Foi realizada análise funcional semanal durante seis semanas através do teste de preensão da musculatura flexora dos dedos, que é específico para avaliar a ação do nervo mediano. Após esse período, os animais foram submetidos a eutanásia. As porções proximal e distal dos nervos foram coradas com azul de toluidina a 1% e realizada a análise histológica. Pela análise morfométrica obteve-se o número e diâmetro dos axônios nos cotos proximais e distais, criando-se uma nova fórmula com inclusão tanto do número como do diâmetro dos axônios para a avaliação da regeneração nervosa. Resultados: Os valores médios da força de preensão exercida pelos ratos do grupo 0 foram comparados aos animais dos grupos II e III através da análise de variância (ANOVA one way). Para a comparação dos valores médios da força realizada pelos ratos do grupo II e III foi feito o teste de Wilkoxon. Do ponto de vista funcional, o grupo III imprimiu uma maior força média com erro menor que 5% e realizou o teste de preensão mais precocemente. O grupo tratado com o GM1 apresentou um número 28% maior de axônios regenerados no segmento distal, com padrão histológico mais organizado e homogêneo e uma diferença significativa no diâmetro médio dos mesmos. Conclusão: Pode-se afirmar com erro menor que 5% que os grupos II (microneurorrafia) e III (microneurorrafia e GM1) apresentaram diferenças em relação à recuperação funcional, tendo o grupo III reagido melhor ao teste de preensão. O padrão histológico do grupo III apresentou maior grau de mielinização, tendo-se observado maior diâmetro médio nos axônios dos cotos distais (p=0,0056). Há um significativo indicio (p=0,0536) de que a utilização do GM1 nas cirurgias dos nervos periféricos melhora o padrão de regeneração axonal. Palavras Chaves: GM1, nervo mediano, regeneração axonal, ratos Wistar, avaliação funcional, morfometria / Abstract: Summary OBJECTIVES: The objective of this study was to compare the treatment of nerve median injuries in Wistar rats submitted to traditional microneurorraphy with the treatment that combined microneurorraphy and monossialoganglioside (GM1) administration while also specifically evaluating if GM1 promotes an increase in median nerve axonal regeneration, thus improving the function of the muscles in its territory of innervation. This comparison was done through functional evaluation measured by the grasping test and histomorphometric analysis. MATERIAL AND METHODS: Experiments were performed in thirty-two Wistar rats. Among them, 10 were randomly selected (group 0) to determine the average grasping strength in normal rats. These animals were then reunited with the others. There were three groups: group I (control group), submitted to a 5 mm lesion in the median nerve of the right forelimb and no treatment. Group II, submitted to lesion of the median nerve proximal to the medial epicondyle, treated with external epineural microneurorraphy, and group III, submitted to the same lesion and treated with external epineural microneurorraphy associated with intraperitoneal administration of GM1. Surgery was undertaken immediately after the damage to the nerve and end-to-end suture was used. Functional analysis through the grasping test of the flexor muscles of the fingers was assessed weekly; this test is specific to evaluate the action of the median nerve. In this experimental model, the animal is lifted by the tail and is stimulated to grasp a bar with its paw; the bar is located on the top of a conventional digital balance. While grasping the bar with its paw, the rat continued to be held by the tail until it releases the bar and the number on the scale is registered. After the functional evaluation the animals were euthanized. The proximal and distal portions of the nerves were colored with 1% toluidine blue dye. After the histologic exam, morphometric analysis was done by counting the number and diameter of the axons in the proximal and distal stumps. A new formula was designed including the number and diameter of the axons to evaluate nerve regeneration. RESULTS: The mean values of grasping strength exerted by rats in group I (control), were compared with group II (only microneurorraphy) and group III (microneurorraphy and GM1) through the analysis of variance (ANOVA one way). To compare the mean values of the strength sustained by rats in groups II and III, the Wilkoxon test was applied. From the functional perspective, the group that received GM1 performed the grasping test earlier, exerting a greater mean strength (error inferior to 5%). The microscopic analysis demonstrated that the group treated with GM1 showed a higher number of regenerated axons better organized and homogenous. And also that this group had a slightly thicker myelin sheath. There was a significant difference in the mean diameter of the axons of the distal segment and a number 28% higher of regenerated axons in the group treated with GM1. CONCLUSIONS: The authors can state with error inferior to 5% that the groups II and III showed differences in relation to functional recovery, group III performing better when submitted to the grasping test. Histological pattern of the group that received GM1 showed a higher degree of myelination. It was observed a greater mean diameter in the axons of distal stumps (p=0,0056). There is a significant indication (p=0,0536) that the use of GM1 in peripheral nerve surgery improves the pattern of axonal regeneration. Key Words: GM1, median nerve, axonal regeneration, Wistar rats, functional evaluation, morphometry / Doutorado / Medicina Interna / Doutor em Ciências Médicas
23

Development of a Z-Stack Projection Imaging Protocol for a Nerve Allograft

Selvam, Selvaanish 31 August 2018 (has links)
No description available.
24

Use of a novel peripheral nerve conduit to support sciatic nerve regeneration in an animal model

Lan Chun Yang, Timothy 06 1900 (has links)
Introduction : Les conduits nerveux synthétiques représentent une alternative chirurgicale aux autogreffes dans la réparation des traumatismes aux nerfs périphériques. Afin d’améliorer la régénération nerveuse périphérique, plusieurs biomatériels, tels que la multicouche polyélectrolyte de soie (MPE), et modèles ont été étudiés. Dans le cadre de ma maitrise, nos objectifs de recherche sont d’établir si la MPE de soie permet d’améliorer la régénération nerveuse périphérique in vivo et si notre nouveau modèle de conduit (« jelly roll ») peut mener à une meilleure régénération du nerf sciatique chez le rat que le modèle de conduit creux. Méthodes : Dans cette étude, une technique chirurgicale in vivo de lacération et de réparation du nerf sciatique chez le rat fut utilisé. Cinq conditions expérimentales de conduits (autogreffe, conduit creux avec et sans MPE de soie et « jelly roll » avec et sans MPE de soie) furent implantées (n= 2 rats par condition). Après 4 semaines, les conduits furent récupérés et marqués par immunohistochimie avec le neurofilament et la protéine basique de la myéline (MBP). La performance de chaque conduit fut évaluée par sa capacité à supporter l’excroissance axonale à travers le long du conduit et à travers la largeur de ce dernier à divers endroits. Résultats : Chaque condition expérimentale a supporté une régénération axonale avec différents degrés de succès. Globalement, l’autogreffe a supporté une plus longue croissance de fibres. De plus, la surface de fibres obtenue était plus large que les autres conditions. Les conduits avec la MPE de soie ont eu une performance similaire à leurs homologues sans soie. De plus, le modèle de conduit creux a mené à une meilleure régénération axonale que le modèle du « jelly roll ». Conclusion : L’autogreffe demeure le meilleur conduit pour supporter la régénération nerveuse périphérique. Les conduits avec la MPE de soie peuvent supporter une régénération nerveuse similaire aux conduits sans soie tandis que le modèle de « jelly roll » a généré des performances inférieures au modèle de conduit creux. / Background: Synthetic nerve conduits constitute alternative surgical options to autografts in the repair of peripheral nerve injuries. Silk polyelectrolyte multilayer (PEM) as a biomaterial and novel conduit designs have been proposed to improve peripheral nerve regeneration. In my master’s project, my objective is to assess whether silk PEM can improve peripheral nerve regeneration in vivo and to assess whether our novel conduit design (“jelly roll”) can better support rat sciatic nerve regeneration than a hollow conduit design. Methods: In this study, an in vivo rat model of sciatic nerve laceration and repair was used. Five experimental conduit conditions (autograft, hollow conduit with and without silk PEM, and jelly roll with and without silk PEM) were implanted (n=2 rats per condition). After 4 weeks, the conduits were harvested and immuno-stained for neurofilament and myelin basic protein (MBP). Conduit performance was assessed by its ability to support axonal outgrowth throughout the conduit’s length and at various locations along its width. Results: Each condition supported axonal regeneration at varying levels of success. Overall, the autograft group outperformed all other groups by supporting the longest and widest occupying regenerating fibers. Conduits with silk PEM performed similarly to conduits without silk PEM. In addition, the hollow conduit design demonstrated better regenerative outcomes than the jelly roll design. Conclusion: The autograft remains the superior conduit to support peripheral nerve regeneration. Conduits with silk PEM support nerve regeneration in the same capacity as non silk-coated conduits while the jelly roll design underperformed in comparison to the hollow conduit design.

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