Grandes perdas de tecido neural não permitem a reparação por meio de anastomose primária. Nesses casos, a auto-enxertia de nervo é considerado o melhor tratamento. A despeito de um tratamento cirúrgico adequado, déficits funcionais são observados e melhoras quanto à recuperação funcional e diminuição das seqüelas são desejáveis. Várias são as técnicas que almejaram esse propósito. A interposição de condutores tubulares, como ponte entre os cotos proximal e distal do nervo seccionado, apresenta-se como uma técnica alternativa que oferece vantagens teóricas. A veia é um material estudado como possível condutor tubular avaliado experimentalmente e em casos clínicos. Estudos recentes têm dado importância na utilização de transplantes de tecidos armazenados em banco de tecidos. O glicerol é utilizado para preservação de tecidos, tendo sido relatado seu uso em nervos e vasos. Entretanto, não há relatos da utilização de veias preservadas em glicerol como substituto de enxerto de nervo. O objetivo deste trabalho foi comparar, em ratos, o grau de regeneração neural, utilizando análise histológica e análise funcional, obtida com a interposição de enxerto autógeno de nervo, veia autógena, veia autógena preservada em glicerol e veia alógena preservada em glicerol. Com técnica microcirúrgica, foram criados defeitos de 5 mm do nervo fibular de ratos da raça Lewis. Os animais foram divididos em quatro grupos de seis, de acordo com o tratamento empregado para correção do defeito: nos animais do Grupo A (grupo controle), foi realizado o reposicionamento do fragmento de nervo retirado (auto-enxerto); nos animais do Grupo B, foi interposto um segmento de 1 cm de veia jugular externa autógena; nos animais do Grupo C, foi interposto a veia jugular externa autógena preservada em glicerol a 98% a 4ºC por sete dias; no Grupo D os animais doadores foram ratos da raça Sprague-Dawley que tiveram a veia jugular externa preservada em glicerol de forma igual ao Grupo C e utilizadas para reconstrução do defeito neural em ratos da raça Lewis, sendo considerado um enxerto alógeno preservado em glicerol. Os animais foram sacrificados após seis semanas para realização dos estudos histológicos. Para a avaliação da recuperação funcional foram estudados os padrões de deambulação dos ratos (\"walking track analysis\") no pós-operatório imediato, 3 e 6 semanas de pós-operatório. O grupo controle (auto-enxerto) apresentou resultados histológicos semelhantes aos grupos de veias preservadas em glicerol (autógena e alógena), entretanto apresentou uma maior reação tecidual perineural e maior presença de escape axonal se comparada a todos os grupos. A utilização de veia autógena sem preservação demonstrou padrão histológico com maior neoangiogênese e áreas de rarefação axonal com presença de tecido conectivo no estroma neoformado. O padrão histológico foi semelhante nos demais grupos. O grupo que utilizou veia autógena (sem glicerol) apresentou menor recuperação funcional quando comparado com os demais grupos para 3 e 6 semanas. O resultado funcional foi estatisticamente semelhante entre os grupos de veias preservadas (autógena e alógena) e o auto-enxerto. / Great losses of neural tissue cannot be repaired by primary conventional suturing. In such cases, nerve autografting is considered to be the treatment of choice. In spite of adequate surgical treatment, functional deficits occur. Also, improvement in functional recuperation and decrease in sequelae are expected. There are many techniques aiming at this purpose. The interposition of tubular conduits, as a bridge between the ends of a sectioned nerve, among these the vein graft, is an alternative technique which offers theoretical advantages. The vein is a studied material as possible evaluated tubular conductor experimentally and in clinical cases. Recent studies have given importance in the use of tissues transplants stored in banks. Glycerol is used for tissue preservation, having been told to its use in nerves and vessels. However, it does not have studies of the use of glycerol reserved veins in as substitute of nerve graft. The purpose of this study was to compare, in rats, the neural regeneration degree, using histological analysis and functional analysis, obtained after interposition of a nerve graft, autogenous vein, autogenous vein preserved in glycerol and allograft vein preserved in glycerol. A 5 mm neural gap in the fibular nerve of rats (Lewis breed) has been created under microsurgical techinique. Four groups of six animals each have been divided according to the treatment employed: Group A - control group: replacement of the fibular nerve itself (autograft); Group B - a 1omm segment of external jugular vein was interposed; Group C - a preserved external jugular vein in glycerol 98% per 7 days was interposed in the fibular nerve gap; Group D - external jugular vein preserved in glycerol of Sprague-Dawley rats had been used equal form to group C in Lewis rats. The animals had been sacrificed after 6 weeks for accomplishment of the histological studies. The functional walking track analysis was performed after in the pre-op, and in the pos-op (immediately, 3 and 6 weeks). The control group (autograft) presented similar histological results to the groups of glycerol preserved veins (autogenous vein and allograft vein), however it presented a bigger perineural tecidual reaction and bigger presence of escape axonal if compared with all the groups. The use of autogenous vein without preservation demonstrated histological results with greater neoangiogenesis and presence of connective tissue inside the neo-formed stroma. Histological pattern was similar to other studied groups. The group that used autogenous vein (without glycerol) presented little functional recovery for 3 and 6 weeks. No statistical difference was seen between groups A (autograft) and groups C and C(preserved veins) in the degree of functional recovery.

A dor neuropática após lesão da medula espinal é uma condição complexa que responde mal aos tratamentos convencionais. O transplante de células representa uma terapia promissora; no entanto, o tipo de célula ideal em termos de potencial neurogênico e eficácia contra a dor permanecem controversos. Assim, o objetivo do presente estudo foi avaliar a capacidade de células tronco neurais fetais (CTNf) em aliviar a dor crônica e, secundariamente, avaliar os efeitos na recuperação motora. Com este propósito, inicialmente foi realizado um piloto para definir o melhor modelo animal, no qual ratos Wistar foram submetidos à lesão medular traumática de intensidade leve ou moderada (altura do pêndulo 12,5mm e 25mm, respectivamente) utilizando o NYU Impactor. Os resultados indicaram que a lesão medular de intensidade moderada é um bom modelo para o estudo da dor neuropática central, pois, além de apresentar um déficit motor e um quadro álgico mais acentuado que os animais submetidos à lesão leve, os animais se mantiveram estáveis ao longo do estudo. Ademais, alterações sensoriais foram observadas desde os primeiros dias após a lesão e permaneceram por pelo menos oito semanas, viabilizando o objetivo do trabalho. Em vista do resultado do piloto, ratos Wistar foram submetidos à lesão medular de intensidade moderada; sete dias após a lesão medular iniciou-se a imunossupressão com ciclosporina, e dez dias após a lesão os animais receberam injeções intra-espinais de meio de cultivo (grupo sham) ou de CTNf extraídas das vesículas telencefálicas (grupo VT) ou da região ponto-bulbar ventral (grupo BV) de embriões E14 da mesma espécie. As avaliações sensitivas e motoras foram realizadas durante oito semanas. Posteriormente, as medulas espinais foram processadas para imunofluorescência e as CTNf transplantadas foram quantificadas por estereologia. Os resultados mostraram uma melhora da hiperalgesia térmica no grupo VT após a quinta semana de transplante (p < 0,001) e no grupo BV após a quarta semana (p < 0,001). Além disso, a alodínia mecânica melhorou nos grupos VT e BV na 8ª semana (VT p < 0,05 e BV p < 0,01 comparados com sham). Nenhuma recuperação motora significativa foi observada nos grupos tratados em relação ao grupo sham. A análise estereológica mostrou que ~70% das células VT e BV diferenciaram-se em neurônios NeuN+, com alta proporção de células encefalinérgicas e GABAérgicas no grupo VT (44% e 42%, respectivamente) e encefalinérgicas e serotoninérgicas no grupo BV (50% e 47%, respectivamente). Nosso estudo sugere que os precursores neuronais oriundos das VT e BV, uma vez implantados na medula espinal lesada, maturam em diferentes subtipos neuronais, principalmente GABAérgicos, serotoninérgicos e encefalinérgicos, e ambos precursores foram capazes de aliviar a dor, apesar de não haver recuperação motora significativa / Neuropathic pain after spinal cord injury (SCI) is a complex condition which responds poorly to usual treatments. Cell transplantation represents a promising therapy; nevertheless, the ideal cell type in terms of neurogenic potential and effectiveness against pain remains largely controversial. Thus, the objective of the present study was to evaluate the ability of fetal neural stem cells (fNSC) to relieve chronic pain and, secondarily, to evaluate the effects on motor recovery. For this purpose, a pilot was initially designed to define the best animal model; accordingly, Wistar rats were submitted to traumatic spinal cord injury of mild or moderate intensity (pendulum height 12.5mm and 25mm, respectively) using the NYU Impactor. The results indicated that spinal cord injury of moderate intensity is a good model for the study of central neuropathic pain, because in addition to a motor function deficit and painful sensation more pronounced than the animals submitted to mild injury, the animals remained stable throughout the study. Additionally, sensitive deficits were observed from the first days after the injury and lasted eight weeks, enabling the objective of the work. Based on the pilot result, Wistar rats were submitted to moderate spinal cord injury; seven days after spinal cord injury, immunosuppression with cyclosporine was initiated; ten days after injury the animals received intra-spinal injections of culture medium (sham group) or fNSC extracted from the telencephalic vesicles (TV group) or from the ventral medulla (VM group) of E14 embryos of the same species. Behavioral and pain assessment were performed weekly during eight weeks. Thereafter, spinal cords were processed for immunofluorescence, and transplanted fetal cells were quantified by stereology. The results showed improvement of thermal hyperalgesia in TV group after the fifth week of transplantation (p < 0.001) and in VM group after the fourth week (p < 0.001). Moreover, mechanical allodynia improved in both TV and VM groups at the 8th week (TV p < 0.05 and VM p < 0.01 compared to sham). No significant motor recovery was observed in TV and VM groups when compared to sham group. Stereological analyses showed that ~70% of TV and VM cells differentiated into NeuN+ neurons, with high proportion of enkephalinergic and GABAergic cells in the TV group (44% and 42%, respectively) and enkephalinergic and Serotoninergic cells in the VM group (50% and 47%, respectively). Our study suggests that neuronal precursors from the TV and VM, once implanted into the injured spinal cord, maturate into different neuronal subtypes, mainly GABAergic, serotoninergic, and enkephalinergic, and both precursors were able to alleviate pain, despite no significant motor recovery

A auto-enxertia de nervo é considerado o melhor tratamento para a restauração de grandes perdas de nervo periférico. Mesmo com o tratamento cirúrgico adequado, déficits funcionais são observados e melhoras quanto à recuperação funcional e diminuição das seqüelas são desejáveis. Várias são as técnicas que almejaram esse propósito. A interposição de condutores tubulares, como ponte entre os cotos proximal e distal do nervo seccionado, apresenta-se como uma técnica alternativa que oferece vantagens teóricas. A veia é um material estudado como possível condutor tubular avaliado experimentalmente e em casos clínicos. Estudos recentes têm dado importância na utilização de transplantes de tecidos armazenados em banco de tecidos. O glicerol é utilizado para preservação de tecidos, tendo sido relatado seu uso em nervos e vasos. Entretanto, não há relatos da utilização de veias preservadas em glicerol como substituto de enxerto de nervo. O objetivo deste trabalho foi comparar, em ratos, o grau de regeneração neural, utilizando análise histológica qualitativa e quantitativa e a recuperação funcional, obtida com a interposição de enxerto autógeno de nervo, veia autógena, veia autógena preservada em glicerol e veia alógena preservada em glicerol. Com técnica microcirúrgica, foram criados defeitos de 5 mm do nervo fibular de ratos da raça Lewis. Os animais foram divididos em quatro grupos de seis, de acordo com o tratamento empregado para correção do defeito: nos animais do Grupo A (grupo controle), foi realizado o reposicionamento do fragmento de nervo retirado (auto- enxerto); nos animais do Grupo B, foi interposto um segmento de 1 cm de veia jugular externa autógena; nos animais do Grupo C, foi interposto a veia jugular externa autógena preservada em glicerol a 98% a 4ºC por sete dias; no Grupo D os animais doadores foram ratos da raça Sprague-Dawley que tiveram a veia jugular externa preservada em glicerol de forma igual ao Grupo C e utilizadas para reconstrução do defeito neural em ratos da raça Lewis, sendo considerado um enxerto alógeno preservado em glicerol. Os animais foram sacrificados após seis semanas para realização dos estudos histológicos. Para a avaliação da recuperação funcional foram estudados os padrões de deambulação dos ratos (walking track analysis)no pós-operatório imediato, 3 e 6 semanas de pós-operatório. O grupo controle (auto-enxerto) apresentou resultados histológicos semelhantes aos grupos de veias preservadas em glicerol (autógena e alógena), entretanto apresentou uma maior reação tecidual perineural e maior presença de escape axonal se comparada a todos os grupos. A utilização de veia autógena sem preservação demonstrou padrão histológico com maior neoangiogênese e áreas de rarefação axonal com presença de tecido conectivo no estroma neoformado. O padrão histológico foi semelhante nos demais grupos. A análise histológica quantitativa demonstrou estatisticamente menor concentração de axônios regenerados no grupo B (veia autógena) do que a dos demais grupos. O grupo que utilizou veia autógena (sem glicerol) apresentou menor recuperação funcional quando comparado com os demais grupos para 3 e 6 semanas. O resultado funcional foi estatisticamente semelhante entre os grupos de veias preservadas (autógena e alógena) e o auto-enxerto / Nerve autografting is considered the best treatment for the restoration of great losses of peripheral nerve. In spite of adequate surgical treatment, functional deficits occur. Also, improvement in functional recuperation and decrease in sequelae are expected. There are many techniques aiming at this purpose. The interposition of tubular conduits, as a bridge between the ends of a sectioned nerve, among these the vein graft, is an alternative technique which offers theoretical advantages. The vein is a studied material as possible evaluated tubular conductor experimentally and in clinical cases. Recent studies have given importance in the use of tissues transplants stored in banks. Glycerol is used for tissue preservation, having been told to its use in nerves and vessels. However, it does not have studies of the use of glycerol reserved veins in as substitute of nerve graft. The purpose of this study was to compare, in rats, the neural regeneration degree, using qualitative and quantitative histological analysis and functional recovery, obtained after interposition of a nerve graft, autogenous vein, autogenous vein preserved in glycerol and allograft vein preserved in glycerol. A 5 mm neural gap in the fibular nerve of rats (Lewis breed) has been created under microsurgical techinique. Four groups of six animals each have been divided according to the treatment employed: Group A Î control group: replacement of the fibular nerve itself (autograft); Group B Î a 1omm segment of external jugular vein was interposed; Group C Î a preserved external jugular vein in glycerol 98% per 7 days was interposed in the fibular nerve gap; Group D - external jugular vein preserved in glycerol of Sprague-Dawley rats had been used equal form to group C in Lewis rats. The animals had been sacrificed after 6 weeks for accomplishment of the histological studies. The functional walking track analysis was performed after in the pre-op, and in the pos-op (immediately, 3 and 6 weeks). The control group (autograft) presented similar histological results to the groups of glycerol preserved veins (autogenous vein and allograft vein), however it presented a bigger perineural tecidual reaction and bigger presence of escape axonal if compared with all the groups. The use of autogenous vein without preservation demonstrated histological results with greater neoangiogenesis and presence of connective tissue inside the neo- formed stroma. Histological pattern was similar to other studied groups. Quantitative histological analysis showed statistically lower concentration of regenerated axons in group B (autogenous vein) than the other groups.The group that used autogenous vein (without glycerol) presented little functional recovery for 3 and 6 weeks. No statistical difference was seen between groups A (autograft) and groups C and C (preserved veins) in the degree of functional recovery

A dor neuropática após lesão da medula espinal é uma condição complexa que responde mal aos tratamentos convencionais. O transplante de células representa uma terapia promissora; no entanto, o tipo de célula ideal em termos de potencial neurogênico e eficácia contra a dor permanecem controversos. Assim, o objetivo do presente estudo foi avaliar a capacidade de células tronco neurais fetais (CTNf) em aliviar a dor crônica e, secundariamente, avaliar os efeitos na recuperação motora. Com este propósito, inicialmente foi realizado um piloto para definir o melhor modelo animal, no qual ratos Wistar foram submetidos à lesão medular traumática de intensidade leve ou moderada (altura do pêndulo 12,5mm e 25mm, respectivamente) utilizando o NYU Impactor. Os resultados indicaram que a lesão medular de intensidade moderada é um bom modelo para o estudo da dor neuropática central, pois, além de apresentar um déficit motor e um quadro álgico mais acentuado que os animais submetidos à lesão leve, os animais se mantiveram estáveis ao longo do estudo. Ademais, alterações sensoriais foram observadas desde os primeiros dias após a lesão e permaneceram por pelo menos oito semanas, viabilizando o objetivo do trabalho. Em vista do resultado do piloto, ratos Wistar foram submetidos à lesão medular de intensidade moderada; sete dias após a lesão medular iniciou-se a imunossupressão com ciclosporina, e dez dias após a lesão os animais receberam injeções intra-espinais de meio de cultivo (grupo sham) ou de CTNf extraídas das vesículas telencefálicas (grupo VT) ou da região ponto-bulbar ventral (grupo BV) de embriões E14 da mesma espécie. As avaliações sensitivas e motoras foram realizadas durante oito semanas. Posteriormente, as medulas espinais foram processadas para imunofluorescência e as CTNf transplantadas foram quantificadas por estereologia. Os resultados mostraram uma melhora da hiperalgesia térmica no grupo VT após a quinta semana de transplante (p < 0,001) e no grupo BV após a quarta semana (p < 0,001). Além disso, a alodínia mecânica melhorou nos grupos VT e BV na 8ª semana (VT p < 0,05 e BV p < 0,01 comparados com sham). Nenhuma recuperação motora significativa foi observada nos grupos tratados em relação ao grupo sham. A análise estereológica mostrou que ~70% das células VT e BV diferenciaram-se em neurônios NeuN+, com alta proporção de células encefalinérgicas e GABAérgicas no grupo VT (44% e 42%, respectivamente) e encefalinérgicas e serotoninérgicas no grupo BV (50% e 47%, respectivamente). Nosso estudo sugere que os precursores neuronais oriundos das VT e BV, uma vez implantados na medula espinal lesada, maturam em diferentes subtipos neuronais, principalmente GABAérgicos, serotoninérgicos e encefalinérgicos, e ambos precursores foram capazes de aliviar a dor, apesar de não haver recuperação motora significativa / Neuropathic pain after spinal cord injury (SCI) is a complex condition which responds poorly to usual treatments. Cell transplantation represents a promising therapy; nevertheless, the ideal cell type in terms of neurogenic potential and effectiveness against pain remains largely controversial. Thus, the objective of the present study was to evaluate the ability of fetal neural stem cells (fNSC) to relieve chronic pain and, secondarily, to evaluate the effects on motor recovery. For this purpose, a pilot was initially designed to define the best animal model; accordingly, Wistar rats were submitted to traumatic spinal cord injury of mild or moderate intensity (pendulum height 12.5mm and 25mm, respectively) using the NYU Impactor. The results indicated that spinal cord injury of moderate intensity is a good model for the study of central neuropathic pain, because in addition to a motor function deficit and painful sensation more pronounced than the animals submitted to mild injury, the animals remained stable throughout the study. Additionally, sensitive deficits were observed from the first days after the injury and lasted eight weeks, enabling the objective of the work. Based on the pilot result, Wistar rats were submitted to moderate spinal cord injury; seven days after spinal cord injury, immunosuppression with cyclosporine was initiated; ten days after injury the animals received intra-spinal injections of culture medium (sham group) or fNSC extracted from the telencephalic vesicles (TV group) or from the ventral medulla (VM group) of E14 embryos of the same species. Behavioral and pain assessment were performed weekly during eight weeks. Thereafter, spinal cords were processed for immunofluorescence, and transplanted fetal cells were quantified by stereology. The results showed improvement of thermal hyperalgesia in TV group after the fifth week of transplantation (p < 0.001) and in VM group after the fourth week (p < 0.001). Moreover, mechanical allodynia improved in both TV and VM groups at the 8th week (TV p < 0.05 and VM p < 0.01 compared to sham). No significant motor recovery was observed in TV and VM groups when compared to sham group. Stereological analyses showed that ~70% of TV and VM cells differentiated into NeuN+ neurons, with high proportion of enkephalinergic and GABAergic cells in the TV group (44% and 42%, respectively) and enkephalinergic and Serotoninergic cells in the VM group (50% and 47%, respectively). Our study suggests that neuronal precursors from the TV and VM, once implanted into the injured spinal cord, maturate into different neuronal subtypes, mainly GABAergic, serotoninergic, and enkephalinergic, and both precursors were able to alleviate pain, despite no significant motor recovery

研究目的：脊髓損傷是中樞神經系統的嚴重創傷，致殘率高。脊髓損傷後的再生修復一直是當前醫學的難題。迄今為止，脊髓損傷依然缺乏一種有效地治療方法。既往研究證明，胰島素樣生長因子-1對鼠和兔脊髓損傷有保護作用，為了進一步把這些發現應用到臨床方面，我們採用與人類生理更相近的豬只作為實驗動物，構建與臨床相似的脊髓損傷動物模型，并以此為基礎，系統性研究胰島素樣生長因子-1的脊髓保護作用，評估該治療的功效。 / 研究方法：以運動誘發電位為指導，通過直接壓迫和牽拉造成脊髓損傷。18頭猪只隨機分為3組：胰島素樣生長因子-1治療組、生長激素治療組及生理鹽水對照組。脊髓損傷后1小時、24小時及48小時經鞘內注射給藥。于術後第1天、第3天及第21天收集腦脊液檢測胰島素樣生長因子-1和生長激素濃度。連續21天使用修正的 Tarlov 評分標準對動物的運動功能進行評估。第21天處死動物並取材，檢測脊髓中NeuN, GFAP, caspase-3 的活性，并通過TUNEL染色觀察細胞凋亡情況，比較各組之間有無差別。 / 研究結果：通過這種方法建立的脊髓損傷動物模型穩定可靠，各組之間無明顯差異。鞘內給藥24小時及48小時后，腦脊液中胰島素樣生長因子-1和生長激素濃度明顯升高，術後21天檢測，其濃度恢復至基礎值。胰島素樣生長因子-1治療組的運動功能的恢復優於其它各組。與生理鹽水對照組比較，胰島素樣生長因子-1治療組可以明顯提高脊髓損傷后神經元的存活數量，抑制星形膠質細胞增生，減少細胞凋亡。而生長激素治療組僅抑制星形膠質細胞增生，其它方面與生理鹽水對照組無明顯差別。 / 結論：胰島素樣生長因子-1通過提高神經元存活數量，抑制星形膠質細胞增生，以及減少細胞凋亡促進脊髓損傷的恢復。 / Objective: Spinal cord injury is a devastating condition that leads to long-term disabilities. Currently, there is no effective treatment that minimizes spinal cord damage or enhances neurological recovery. Recent studies in rats or rabbits suggested that neurologic recovery after spinal cord injury could be improved with the administration of neurotropic hormones, such as insulin-like growth factor-1 (IGF-1). In order to apply such bench-side discovery to clinical practice, we conducted a study in a higher animal model, akin to human physiology, to evaluate the effectiveness of intrathecal injections of IGF-1to improve neurological recovery in a porcine model of acute traumatic spinal cord injury. / Methods: Traumatic spinal cord injury model was produced by controlled compression and distraction of the exposed T12 segment of the spinal cord. Eighteen pigs were randomly assigned to receive intrathecal injections of either IGF-1, growth hormone or saline at 1, 24 and 48 hours after spinal cord injury. Locomotor function was assessed daily using the validated modified Tarlov’s scale for 21 days. Spinal cord segments were then harvested and the survival of neurons, reactive astrogliosis and apoptosis were determined using neuronal-specific nuclear protein (NeuN), glial fibrillary acidic protein (GFAP), cleaved caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assays. / Results: Intrathecal injections of IGF-1 and growth hormone significantly increase the concentrations of the neurotropic hormones in the cerebrospinal fluid after injury (p < 0.01). These concentrations returned to baseline by 21 days after drug delivery. Motor deficits on the first day after injury were comparable between animals in the treatment and control groups. By the end of the third week, neurologic recovery was better in animals receiving IGF-1 treatment (p < 0.05). Immunohistological and western blot studies of the injured segments of spinal cord showed that treatment with both IGF-1 and growth hormone prevented reactive astrogliosis (p < 0.05) while only IGF-1 improved the survival of mature neurons (p < 0.05). IGF-1 also inhibited apoptosis after spinal cord injury (p < 0.05). / Conclusions: In our clinically relevant model of traumatic spinal cord injury in pigs, intrathecal injection of IGF-1 demonstrated beneficial effects on neurological and histological recovery. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wang, Qinzhou. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 105-122). / Abstract also in Chinese. / Declaration of origination --- p.I / Abstract --- p.II / Acknowledgements --- p.VI / Table of Contents --- p.VIII / List of Tables --- p.XII / List of Figures --- p.XIII / Abbreviations --- p.XVIII / Chapter Part 1 --- Spinal Cord Injury: A Review --- p.1 / Chapter Chapter 1-1 --- Acute Spinal Cord Injury: Epidemiology, Socioeconomic Impact --- p.2 / Chapter 1.1.1 --- Epidemiology of Spinal Cord Injury --- p.2 / Chapter 1.1.2 --- Socioeconomic Impact of Acute Spinal Cord Injury --- p.5 / Chapter Chapter 1-2 --- Mechanisms of Spinal Cord Injury --- p.6 / Chapter Chapter 1-3 --- Putative Treatments for Spinal Cord Injury --- p.8 / Chapter 1.3.1 --- Methylprednisolone --- p.8 / Chapter 1.3.2 --- Stem Cell Therapy --- p.11 / Chapter 1.3.3 --- Riluzole --- p.11 / Chapter 1.3.4 --- Other Pharmacological Therapies for Spinal Cord Injury --- p.12 / Chapter Chapter 1-4 --- Insulin-like Growth Factor-1 for the Treatment of Spinal Cord Injury --- p.13 / Chapter Chapter 1-5 --- Summary --- p.17 / Chapter Part 2 --- Insulin-like Growth Factor-1 and Growth Hormone for Spinal Cord Injury --- p.18 / Chapter Chapter 2-1 --- Hypothesis and Objectives --- p.19 / Chapter Chapter 2-2 --- Establishment of Animal Models for Acute Spinal Cord Injury --- p.22 / Chapter 2.2.1 --- Introduction --- p.22 / Chapter 2.2.2 --- Experimental Animals --- p.22 / Chapter 2.2.3 --- Anesthesia --- p.23 / Chapter 2.2.4 --- Transcranial Electrical Motor Evoked Potential --- p.26 / Chapter 2.2.5 --- Surgery --- p.28 / Chapter 2.2.6 --- Statistics --- p.34 / Chapter 2.2.7 --- Results --- p.34 / Chapter 2.2.8 --- Discussion --- p.38 / Chapter Chapter 2-3 --- Optimal Stimulation Protocols for Transcranial Electrical Motor Evoked Potential. --- p.42 / Chapter 2.3.1 --- Introduction --- p.42 / Chapter 2.3.2 --- Methods --- p.42 / Chapter 2.3.2.1 --- Experimental Animals and Anesthesia --- p.42 / Chapter 2.3.2.2 --- Transcranial Electrical Motor Evoked Potential Recording --- p.44 / Chapter 2.3.2.3 --- Stimulation Protocol --- p.44 / Chapter 2.3.3 --- Analyses --- p.44 / Chapter 2.3.4 --- Results --- p.45 / Chapter 2.3.5 --- Discussion --- p.52 / Chapter Chapter 2-4 --- Evaluation of the Efficacy of Insulin-like Growth Factor-1 and Growth Hormone in a Porcine Model --- p.54 / Chapter 2.4.1 --- Introduction --- p.54 / Chapter 2.4.2 --- Materials and Methods --- p.54 / Chapter 2.4.2.1 --- Study Design --- p.54 / Chapter 2.4.2.2 --- Intrathecal Injection and Collection of Cerebrospinal Fluid --- p.58 / Chapter 2.4.2.3 --- Measurements --- p.58 / Chapter 2.4.2.3.1 --- Clinical Evaluation --- p.58 / Chapter 2.4.2.3.2 --- Biochemical Assessments --- p.58 / Chapter 2.4.2.3.3 --- Spinal Cord Section, Histological and Immunochemical Staining --- p.63 / Chapter 2.4.2.3.4 --- Western Blot --- p.69 / Chapter 2.4.3 --- Statistical Analysis and Sample Size Calculation --- p.72 / Chapter 2.4.3.1 --- General Analysis --- p.72 / Chapter 2.4.3.2 --- Sample Size --- p.72 / Chapter 2.4.4 --- Results --- p.73 / Chapter 2.4.4.1 --- Changes of TceMEP --- p.73 / Chapter 2.4.4.2 --- Motor Deficit after Spinal Cord Injury at Baseline --- p.75 / Chapter 2.4.4.3 --- Insulin-like Growth Factor-1 and Growth Hormone in Cerebrospinal Fluid --- p.77 / Chapter 2.4.4.4 --- Clinical Assessment --- p.80 / Chapter 2.4.4.5 --- Demyelination, Neuron Survival and Astrocyte Reaction --- p.85 / Chapter 2.4.4.6 --- Apoptosis --- p.89 / Chapter 2.4.5 --- Discussion --- p.93 / Chapter 2.4.5.1 --- Principal Findings --- p.93 / Chapter 2.4.5.2 --- Insulin-like Growth Factor-1 and Neuroprotection after Spinal Cord Injury --- p.93 / Chapter 2.4.5.3 --- Growth Hormone and Neuroprotection after Spinal Cord Injury --- p.95 / Chapter 2.4.5.4 --- Strengths and Limitations of Our Study --- p.96 / Chapter 2.4.5.5 --- Summary --- p.97 / Chapter Part 3 --- Summary and Future Directions --- p.99 / Chapter Chapter 3-1 --- Summary --- p.100 / Chapter Chapter 3-2 --- Future Directions --- p.103 / Chapter Part 4 --- References and appendixes --- p.104 / References --- p.105 / Appendixes --- p.123

In response to high and rising amputation rates, significant advances have been made in the field of prosthetic limb design. Unfortunately, there exists a lag in the neural interfacing technology required to provide an adequate link between the nervous system and this emerging generation of advanced prosthetic devices. Novel approaches to peripheral nerve interfacing are required to establish the stable, high channel count connections necessary to provide natural, thought driven control of an external prosthesis. Here, a tissue engineering-based approach has been used to create a device capable of interfacing with a regenerated portion of amputated nerve. As part of this work, a nerve guidance channel design, in which small amounts of interior scaffolding material could be precisely positioned, was evaluated. Guidance channels containing a single thin-film sheet of aligned scaffolding were shown to support robust functional nerve regeneration across extended injury gaps by minimally supplementing natural repair mechanisms. Significantly, these "thin-film enhanced nerve guidance channels" also provided the capability to guide the course of axons regenerating from a cut nerve. This capability to control axonal growth was next leveraged to create "regenerative scaffold electrodes (RSEs)" able to interface with axons regenerating from an amputated nerve. In the RSE design, low-profile arrays of interfacing electrodes were embedded within layers of aligned scaffolding material, such that regenerating axons were topographically guided by the scaffolding through the device and directly across the embedded electrodes. Chronically implanted RSEs were successfully used to record evoked neural activity from amputated nerves in an animal model. These results demonstrate that the use of topographic cues within a nerve guidance channel might offer the potential to influence the course of nerve regeneration to the advantage of a peripheral nerve interface suitable for limb amputees.

[Truncated abstract] There is limited intrinsic potential for repair in the adult human central nervous system (CNS). Dysfunction resulting from CNS injury is persistent and requires prolonged medical treatment and rehabilitation. The retina and optic nerve are CNSderived, and adult retinal ganglion cells (RGCs) and their axons are often used as a model in which to study the mechanisms associated with injury, neuroprotection and regeneration. In this study I investigated the effects of a variety of strategies on promoting RGC survival and axonal regeneration after optic nerve injury, including the use of reconstructed chimeric peripheral nerve (PN) grafts, gene therapy, and intraocular application of pharmacological agents and other factors . . . C3 transferase is an enzyme derived from Clostridium botulinum that inactivates Rho GTPase. Because SC myelin contains MAG and PN also contains CSPGs, I tested the effects of intraocular injection of a modified form of C3 (C3-11), provided by Dr Lisa McKerracher (CONFIDENTIAL data, under IP agreement with Bioaxone Therapeutic, Montreal) on RGC axonal regeneration into PN autografts. My results showed that there was significantly more RGC survival and axonal regeneration in PN autografts after repeated intraocular injection of C3. I also tested whether intraocular injections of CPT-cAMP and/or CNTF can act in concert with the C3 to further increase RGC survival and/or regeneration. Results showed that the effect of C3 and CPT-cAMP plus CNTF were synergistic and partially additive. The use of combination therapies therefore offers the best hope for robust and substantial regeneration. The overall results from my PhD project will help determine how best to reconstruct nerve pathways and use pharmacological interventions in the clinical treatment of CNS injury, hopefully leading to improved functional outcomes after neurotrauma.

Diss. (sammanfattning) Umeå : Umeå universitet, 2010.

INTRODUÇÃO: A reparação das lesões de nervos periféricos com perda extensa de substância, onde a sutura direta não é viável, ainda apresenta nos dias atuais resultados variáveis e dependentes de diversos fatores. O tratamento mais comumente utilizado nestes casos é a auto-enxertia de nervos, com sacrifício de um nervo de outra região do corpo, procedimento que, entretanto, pode trazer algumas dificuldades e consequências. Desta forma, a busca por novas técnicas, como a possibilidade de utilização de nervos preservados em baixas temperaturas, representa um avanço inestimável no campo da reparação de lesões nervosas. OBJETIVO: O objetivo deste estudo foi realizar avaliações funcionais, eletrofisiológicas e histomorfométricas que permitam comparar a regeneração nervosa autógena em enxerto convencional versus enxerto preservado a frio, em modelo experimental de ratos, após denervação a fresco ou conservação de um segmento do nervo em baixa temperatura por 14 dias e por 50 dias. MÉTODOS: Foram utilizados 20 ratos Wistar de peso e idades aproximadamente iguais, divididos em quatro grupos de cinco animais. Os grupos 1 e 3 serviram de controle respectivamente para os grupos 2 e 4, utilizando enxertia de nervo convencional por 14 dias (grupo 1) e por 50 dias (grupo 3). O grupo 2 utilizou enxertia de nervo preservado a 4 graus Celsius em solução Celsior® por 14 dias, enquanto o grupo 4 foi submetido à preservação a frio na mesma solução por 50 dias. Foram realizadas análises funcionais da marcha, análises de potenciais evocados e análises histomorfométricas dos animais em diversos momentos. As análises funcionais utilizaram uma aparelhagem própria para estudo da marcha em pequenos animais de experimentação, denominada catWalk®, que fornece medidas estáticas e dinâmicas da marcha, com parâmetros como a pressão em relação à pata contralateral e a área máxima da impressão plantar do animal, tendo sido captados os dados antes do procedimento de retirada do enxerto e após a realização da enxertia, neste último caso com avaliações quinzenais até que tenham sido completados 60 dias de pós- operatório. As análises de potenciais evocados motores analisaram a latência e a amplitude dos estímulos nervosos e foram realizadas 60 dias após os procedimentos de enxertia. As análises microscópicas observaram a contagem de axônios mielinizados e a área destas fibras nervosas nas regiões proximal e distal aos reparos, aos 60 dias após os procedimentos, comparando também as relações entre a região distal e proximal de cada um destes parâmetros através dos índices de regeneração e mudança de área. RESULTADOS: A enxertia com nervo preservado a frio por 14 dias apresentou resultado funcional semelhante ao seu grupo controle na análise da área máxima de contato e da pressão máxima de contato da pata operada em todas as avaliações. Já a conservação do enxerto a frio por 50 dias resultou em superioridade funcional em todos as avaliações em relação a seu grupo controle. Os estudos eletrofisiológicos mostraram cada grupo de enxertia preservada a frio com resultados similares a seu grupo controle, tanto em relação à latência, quanto à amplitude nos dois músculos avaliados. As análises histomorfométricas resultaram em índices de regeneração e de mudança de área semelhantes na comparação entre os grupos 60 dias após os procedimentos de enxertia. CONCLUSÕES: A conservação a frio do enxerto de nervo durante 14 dias e durante 50 dias apresentou resultados funcionais da regeneração iguais ou superiores aos enxertos convencionais e resultados eletrofisiológicos e histológicos semelhantes aos respectivos grupos controle de enxertos convencionais, demonstrando um futuro promissor para a utilização clínica de enxertos preservados a frio em um \"banco de nervos\" / INTRODUCTION: The repair of peripheral nerve injuries with extensive loss of substance, where direct suture is not feasible, at the present time still has variable results and dependence on many factors. The treatment most commonly used in these cases is the nerve autograft, with sacrifice of a nerve from another region of the body. This procedure, however, can sometimes lead to some difficulties and consequences. Therefore, the search for new techniques such as the possibility of using cold preserved nerves, is a great advancement in the field of repairing nerve damage. OBJECTIVE: The purpose of this study was to perform functional, electrophysiological and histomorphometric evaluations to compare conventional autografts versus cold-preserved autografts of the sciatic nerves of rats, after fresh denervation or conservation of a nerve segment at low temperature for 14 days and 50 days. METHODS: 20 Wistar rats of approximately equal ages and weight were divided into 4 groups of 5 animals. Groups 1 and 3 were treated with a conventional nerve graft after denervation for 14 days and 50 days, respectively; they served as controls for groups 2 and 4, which were treated with cold-preserved nerve grafts immersed in a Celsior® solution at 4 degrees Celsius for 14 and 50 days, respectively. Functional gait analysis, evoked potential analysis and histomorphometric analysis of the animals were performed at different times. Functional analysis used equipment for gait study in small animal experiments, called catWalk®, which provides static and dynamic measurements, with parameters such as pressure relative to contralateral paw and the maximum area of the footprint of the animal, and these data were captured before the graft withdrawal procedure and after grafting, in this latter case the functional analysis was made every 15 days until they had been completed 60 days after surgery. The motor evoked potential analysis examined the latency and amplitude of nerve stimuli and was made 60 days after the grafting procedures. The microscopic analysis measured myelinated axons and the area of these nerve fibers in the proximal and distal regions to the repair sites at the end of 60 days after the procedures, also comparing the relationship between the distal and proximal regions of each of these parameters through the regeneration and area change rates. RESULTS: Cold preservation of nerve graft for 14 days showed functional results similar to those of its control group for the maximum contact area and for the maximum pressure intensity of the operated paw in all evaluations. Cold preservation of nerve graft for 50 days resulted in functional superiority in all assessments compared with its control group. Cold preservation of nerve graft for 14 days and 50 days showed electrophysiological results similar to those of their respective control groups, both in terms of latency, as to the amplitude in the two muscles evaluated. Histomorphometric analysis showed similar regeneration and area change rates for all the groups 60 days after the grafting procedures. CONCLUSIONS: The cold preservation of nerve grafts for 14 days and 50 days showed similar or superior functional results and similar electrophysiological and histological results compared with their respective conventional graft control groups, indicating a promising future for the clinical utilization of cold preserved grafts in a \"nerve bank\"

INTRODUÇÃO: As lesões traumáticas graves do nervo facial, relativamente frequentes no cotidiano do otorrinolaringologista, mesmo que reparadas com as melhores técnicas microcirúrgicas, apresentam recuperação funcional extremamente limitada acarretando grande impacto na motricidade facial e, consequentemente, na qualidade de vida dos pacientes. OBJETIVOS: Avaliar a recuperação funcional (eletroneuromiografia), histológica (quantitativa e qualitativa) e imunohistoquímica do ramo mandibular do nervo facial de ratos obtidas após autoenxerto combinado a transplante de células-tronco multipotentes de polpa dentária indiferenciadas (CTPD). Seguiu-se comparação com os resultados anteriormente obtidos pelos mesmos pesquisadores e utilizando mesma técnica cirúrgica após transplante de células-tronco de medula óssea indiferenciadas (CTMOi) e diferenciadas em Schwann-like (CTMOd). Realizou-se autoenxerto no ramo mandibular do nervo facial de ratos para reparo de GAP de 5mm provocado por duas neurotmeses sequenciais, reimplantação do próprio fragmento retirado, sendo o mesmo envolvido por tubo de ácido poliglicólico (Grupo A) e preenchido com gel acelular de lâmina basal purificada, com transplante de CTPD (grupo B). Após seis semanas, os animais foram sacrificados e as análises realizadas. RESULTADOS: Observou-se que, seis semanas após a cirurgia, os animais do grupo tratado com células-tronco apresentaram valores médios de amplitude do potencial de ação muscular composto (PAMC) (CTPD 3,79±1,74mV; CTMOd 2,7±0,53mV; CTMOi 1,81±0,77mV) estatisticamente superiores ao grupo controle (0,75±0,46mV, p < 0,001). Os diâmetros axonais médios, também, foram significativamente maiores nos grupos tratados com células-tronco (CTPD 3,04±0,49?m; CTMOd 3,5±0,16?m; CTMOi 3,15±0,32?m) do que no grupo controle (2,13±0,07?m), com valor de p < 0,001. A densidade axonal foi estatisticamente superior no grupo controle (0,021±0,003axônios/um2) quando comparada aos grupos tratados (CTPD 0,014±0,004 axônios/um2; CTMOd 0,017±0,003axônios/?m2; CTMOi 0,015±0,002axônios/um2, p=0,004).Ao ensaio de imunofluorescência, no grupo tratado com CTPD, observou-se células positivas para lamina humana A/C e para S100, evidenciando, assim, a presença de células humanas com fenótipo de Schwann no segmento distal do nervo analisado. No grupo tratado com CTMOi houve marcação em beta-galactosidade, mas não em S100, confirmando a presença de células exógenas, porém não diferenciadas em Schwann. Já no grupo tratado com CTMOd demonstrou a presença de células exógenas com fenótipo de Schwann ao observar a comarcação pelos marcadores beta-galactosidase e S100, mantendo, assim, o mesmo fenótipo do observado in vitro. CONCLUSÃO: Conclui-se que, segundo critérios funcionais e histológicos, a regeneração do ramo mandibular do nervo facial de ratos foi superior quando associada ao transplante de CTPD comparativamente ao controle. O grupo tratado com CTPD apresentou melhores resultados funcionais e parâmetros histológicos similares aos obtidos com CTMOi e CTMOd. Nos três grupos tratados com células-tronco, as células exógenas foram observadas após 6 semanas de experimento, com evidência de integração ao tecido neural e evidência de diferenciação in vivo para o fenótipo de Schwann apenas no grupo tratado com CTPD / INTRODUCTION: Traumatic lesions of the facial nerve, relatively frequent of the daily routine of the otorhinolaryngologist, even if when repaired with the best microsurgical techniques, have limited functional recovery causing great impact on facial motricity, consequently, on patients\' quality of life. OBJECTIVES: The purpose of this study was to evaluate the functional and histological recovery (quantitative and qualitative) and immunohistochemistry of the mandibular branch of the facial nerve of rats obtained after autograft combined with transplantation of multipotent undifferentiated dental pulp stem cells (DPSC). We compared the results obtained previously by the same researchers and using the same surgical technique after transplantation of undifferentiated bone marrow stem cells (uBMSC) and differentiated to Schwann cell-like (dBMSC). METHODS: A 5mm gap in the mandibular branch of the facial nerve was perfomed by two sequencial neurotmesis, followed by autograft with reimplantation of the removed fragment itself, tubulization with a polyglycolic acid tube (Group A) and transplantation with DPSC (group B). After six weeks, the animals were sacrificed and analyzes performed. RESULTS: Six weeks after surgery, the animals in the stem cells group had mean values of the amplitude of the compound muscle action potential (CMAP) (DPSC 3.79±1.74mV; dBMSC 2.7±0,53mV; uBMSC 1.81±0.77mV) statistically higher than the control group (0.75±0.46mV, p < 0.001). Medium axon diameters were also significantly higher in the stem cells treated groups (DPSC 3.04±0.49um, dBMSC 3.5±0.16um, uBMSC 3.15± 0.32um) than in the control group (2.13±0.07um), with a value of p < 0.001. The axonal density was statistically higher in the control group (0.021±0.003axons/um2) when compared to the treated groups (DPSC 0.014±0.004 axons/?m2, dBMSC 0.017±0.003 axons/?m2, uBMSC 0.015±0.002 axons/um2, p=0.004). In the immunofluorescence assay, cells positive for human laminA/C and for S100 were observed in the DPSC-treated group, thus evidencing the presence of human cells with Schwann cells phenotype in the distal segment of the nerve analyzed. In the group treated with uBMSC there was beta- galactosidase, but not in S100, confirming the presence of exogenous but undifferentiated cells. In the group treated with dBMSC, the presence of exogenous cells with Schwann cells phenotype was observed by observing the comarcation by beta-galactosidase and S100 markers, thus maintaining the same phenotype as that observed in vitro. CONCLUSION: According to functional and histological criteria, the regeneration of the mandibular branch of the facial nerve of rats was superior when associated with the DPSC transplant compared to the control. The DPSC treated group had better functional results and histological parameters similar to those obtained with uBMSC and dBMSC. In the stem cells-treated groups, exogenous cells were observed after 6 weeks of experiment with evidence of neural tissue integration and evidence of in vivo differentiation for the Schwann cells phenotype only in the DPSC-treated group