Use of aerobic treadmill exercises on nerve regeneration after sciatic nerve injury in spontaneously hypertensive rats

Purpose: Various postoperative protocols have been proposed to improve outcomes and accelerate nerve regeneration. Recently, the use of physical exercise in a post-surgical neurorraphy procedure has shown good results when started early. We experimentally investigated the hypothesis that post-operative exercise speeds up results and improves clinical and morphologic parameters. Methods: Isogenic rats were randomly divided into four groups: 1 SHAM; 2 SHAM submitted to the exercise protocol (EP); 3 Grafting of the sciatic nerve; and 4 Grafting of the sciatic nerve associated with the EP. The EP was based on aerobic activities with a treadmill, with a progressive increase in time and intensity during 6 weeks. The results were evaluated by the sciatic functional index (SFI), morphometric and morphologic analysis of nerve distal to the lesion, and the number of spinal cord motor neurons, positive to the marker Fluoro-Gold (FG), captured retrogradely through neurorraphy. Results: Functional analysis (SFI) did not show a statistical difference between the group grafted with (­50.94) and without exercise (-65.79) after 90 days. The motoneurons count (Spinal cord histology) also showed no diference between these groups (834.5 × 833 respectively). Although functionally there is no difference between these groups, morphometric study showed a greater density (53.62) and larger fibers (7.762) in GRAFT group. When comparing both operated groups with both SHAM groups, all values were much lower. Conclusions: The experimental model that this aerobic treadmill exercises protocol did not modify nerve regeneration after sciatic nerve injury and repair with nerve graft.

Two-dimensional and three-dimensional techniques for determining the kinematic patterns for hindlimb obstacle avoidance during sheep locomotion / Técnicas bidimensionais e tridimensionais para determinar os padrões cinemáticos durante a ultrapassagem de obstáculos pelos membros pélvicosdurante a locomoção de ovinos

Analysis of locomotion is often used as a measure for impairment and recovery following experimental peripheral nerve injury. Compared to rodents, sheep offer several advantages for studying peripheral nerve regeneration. In the present study, we compared for the first time, two-dimensional (2D) and three-dimensional (3D) hindlimb kinematics during obstacle avoidance in the ovine model. This study obtained kinematic data to serve as a template for an objective assessment of the ankle joint motion in future studies of common peroneal nerve (CP) injury and repair in the ovine model. The strategy used by the sheep to bring the hindlimb over a moderately high obstacle, set to 10% of its hindlimb length, was pronounced knee, ankle and metatarsophalangeal flexion when approaching and clearing the obstacle. Despite the overall time course kinematic patterns about the hip, knee, ankle, and metatarsophalangeal were identical, we found significant differences between values of the 2D and 3D joint angular motion. Our results showed that the most apparent changes that occurred during the gait cycle were for the ankle (2D-measured STANCEmax: 157±2.4 degrees vs. 3D-measured STANCEmax: 151±1.2 degrees; P .05) and metatarsophalangeal joints (2D-measured STANCEmin: 151±2.2 degrees vs. 3D-measured STANCEmin: 162 ± 2.2 degrees; P .01 and 2D-measured TO: 163±4.9 degrees vs. 3D-measured TO: 177±1.4 degrees; P .05), whereas the hip and knee joints were much less affected. Data and techniques described here are useful for an objective assessment of altered gait after CP injury and repairin an ovine model.(AU)

A análise da locomoção é frequentemente usada como uma medida para avaliar a disfunção e sua recuperação após lesão nervosa periférica experimental. Quando comparadas com os roedores, as ovelhas oferecem várias características atrativas como modelo experimental para o estudo da regeneração nervosa periférica. Não existem estudos acerca dos resultados da locomoção após lesão e reparação do nervo periférico no modelo ovino. No presente estudo, realizámos e comparámos a cinemática bidimensional (2D) e, pela primeira vez, tridimensional (3D) do membro pélvico durante a ultrapassagem de obstáculos no modelo ovino. Este estudo teve como objetivo obter dados cinemáticos para servir de modelo para uma avaliação objetiva do movimento articular do tornozelo em estudos futuros de lesão e reparação do nervo fibular comum (FC) no modelo ovino. A estratégia usada pelas ovelhas para elevar o membro pélvico sobre um obstáculo com uma altura moderada, fixado em 10% do seu comprimento, caracteriza-se por uma flexão pronunciada do joelho, tornozelo e metatarso-falangeana ao se aproximar e ultrapassar o obstáculo. Apesar dos padrões cinemáticos do quadril, joelho, tornozelo e metatarso-falangeano terem sido idênticos, foram encontradas diferenças significativas entre os valores do movimento angular das articulações em 2D e 3D. Os nossos resultados mostram que as mudanças mais aparentes que ocorreram durante o ciclo da marcha foram nas articulações do tornozelo (em 2DSTANCEmax: 157±2.4 graus vs. em 3D STANCEmax: 151±1.2 graus; P .05) e metatarso-falangeana (em 2D STANCEmin: 151±2.2 graus vs. em 3D STANCEmin: 162 ± 2.2 graus; P .01 e em 2D TO: 163±4.9 graus vs. em 3D TO: 177±1.4 graus; P .05), enquanto as articulações do quadril e do joelho foram muito menos afetadas. É provável que os dados e técnicas descritas aqui sejam úteis para uma avaliação objetiva das alterações na marcha após lesão e reparação do PC no modelo ovino.(AU)

Mechanical properties of the sciatic nerve following combined transplantation of analytically extracted acellular allogeneic nerve and adipose-derived mesenchymal stem cells

Purpose To investigate the effects of Chemically Extracted Acellular Nerves (CEANs) when combined with Adipose-Derived mesenchymal Stem Cell (ADSC) transplantation on the repair of sciatic nerve defects in rabbits. Methods A total of 71 six-month-old Japanese rabbit were used in this study. Twenty rabbits served as sciatic nerve donors, while the other 51 rabbits were randomly divided into Autologous Nerve Transplantation Group (ANT, n=17), CEAN group (n=17) and CEAN-ADSCs group (n=17). In all these groups, the rabbits left sciatic nerves were injured before the experiment, and the uninjured sciatic nerves on their right side were used as the control (CON). Electrophysiological tests were carried out and sciatic nerves were prepared for histomorphology and stretch testing at 24 weeks post-transplant. Results There were significant differences between ANT and Con groups in amplitude (AMP): P=0.031; motor nerve conduction velocity (MNCV): P=0.029; Maximum stress: P=0.029; and Maximum strain P=0.027. There were also differences between the CEAN and CEAN+ADSCs groups in AMP: P=0.026, MNCV: P=0.024; Maximum stress: P=0.025 and Maximum strain: P=0.030. No significant differences in these parameters were observed when comparing the ANT and CEAN+SACN groups (MNCV: P=0.071) or the CEAN and ANT groups (Maximum stress: P=0.069; Maximum strain P=0.077). Conclusion Addition of ADSCs has a significant impact on the recovery of nerve function, morphology, and tensile mechanical properties following sciatic nerve injury.(AU)

Combination of heterologous fibrin sealant and bioengineered human embryonic stem cells to improve regeneration following autogenous sciatic nerve grafting repair

Background Peripheral nerve injury is a worldwide clinical problem, and the preferred surgical method for treating it is the end-to-end neurorrhaphy. When it is not possible due to a large nerve gap, autologous nerve grafting is used. However, these surgical techniques result in nerve regeneration at highly variable degrees. It is thus very important to seek complementary techniques to improve motor and sensory recovery. One promising approach could be cell therapy. Transplantation therapy with human embryonic stem cells (hESCs) is appealing because these cells are pluripotent and can differentiate into specialized cell types and have self-renewal ability. Therefore, the main objective of this study was to find conditions under which functional recovery is improved after sciatic nerve neurorrhaphy. We assumed that hESC, either alone or in combination with heterologous fibrin sealant scaffold, could be used to support regeneration in a mouse model of sciatic nerve injury and repair via autografting with end-to-end neurorrhaphy. Methods Five millimeters of the sciatic nerve of C57BL/6 J mice were transected off and rotated 180 degrees to simulate an injury, and then stumps were sutured. Next, we applied heterologous fibrin sealant and/or human embryonic stem cells genetically altered to overexpress fibroblast growth factor 2 (FGF2) at the site of the injury. The study was designed to include six experimental groups comprising neurorrhaphy (N), neurorrhaphy + heterologous fibrin sealant (N + F), neurorrhaphy + heterologous fibrin sealant + doxycycline (N + F + D), neurorrhaphy + heterologous fibrin sealant + wild-type hESC (N + F + W), neurorrhaphy + heterologous fibrin sealant + hESC off (N + F +T), and neurorrhaphy + heterologous fibrin sealant + hESC on via doxycycline (N + F + D + T). We evaluated the recovery rate using Catwalk and von Frey functional recovery tests, as well as immunohistochemistry analysis. Results The experiments indicated...

Combination of heterologous fibrin sealant and bioengineered human embryonic stem cells to improve regeneration following autogenous sciatic nerve grafting repair

Background Peripheral nerve injury is a worldwide clinical problem, and the preferred surgical method for treating it is the end-to-end neurorrhaphy. When it is not possible due to a large nerve gap, autologous nerve grafting is used. However, these surgical techniques result in nerve regeneration at highly variable degrees. It is thus very important to seek complementary techniques to improve motor and sensory recovery. One promising approach could be cell therapy. Transplantation therapy with human embryonic stem cells (hESCs) is appealing because these cells are pluripotent and can differentiate into specialized cell types and have self-renewal ability. Therefore, the main objective of this study was to find conditions under which functional recovery is improved after sciatic nerve neurorrhaphy. We assumed that hESC, either alone or in combination with heterologous fibrin sealant scaffold, could be used to support regeneration in a mouse model of sciatic nerve injury and repair via autografting with end-to-end neurorrhaphy. Methods Five millimeters of the sciatic nerve of C57BL/6 J mice were transected off and rotated 180 degrees to simulate an injury, and then stumps were sutured. Next, we applied heterologous fibrin sealant and/or human embryonic stem cells genetically altered to overexpress fibroblast growth factor 2 (FGF2) at the site of the injury. The study was designed to include six experimental groups comprising neurorrhaphy (N), neurorrhaphy + heterologous fibrin sealant (N + F), neurorrhaphy + heterologous fibrin sealant + doxycycline (N + F + D), neurorrhaphy + heterologous fibrin sealant + wild-type hESC (N + F + W), neurorrhaphy + heterologous fibrin sealant + hESC off (N + F +T), and neurorrhaphy + heterologous fibrin sealant + hESC on via doxycycline (N + F + D + T). We evaluated the recovery rate using Catwalk and von Frey functional recovery tests, as well as immunohistochemistry analysis. Results The experiments indicated...(AU)

Comparative study between standard and inside-out vein graft techniques on sciatic nerve repair of rats: muscular and functional analysis

Purpose: To compare the functional result of standart vein grafts and inside-out vein graft technique on sciatic nerve repair. Methods: We used 24 male Wistar rats divided into 4 groups: control group (CG), standard vein graft group (SVG), Inside-out vein graft group (IOVG) and denervated Group (DG). SVG, IOVG and DG underwent total section of the sciatic nerve, SVG and IOVG however underwent nerve repair surgery using a graft with normal jugular vein and inside-out jugular vein, respectively. Histological analysis of the soleus and Extensor Digitorum Longus (EDL), and Sciatic Functional Index were used to compare the results after 6 weeks. Results: Both grafts acted favorably in muscle recovery and improved functionality; They were similar in all parameters, however, in more points SVG achieved similar to the CG, in the other hand IOVG more times was similar to DG. Fact that makes the graft with normal vein the most viable option between the two options. Conclusion: Both types of grafts acted beneficially wherein the graft normal vein has proved to be the best option.(AU)

Inside-out and standard vein grafts associated with platelet-rich plasma (PRP) in sciatic nerve repair. A histomorphometric study

Purpose: To evaluated the tubulization technique with standard and inside-out vein, filled or not with platelet-rich plasma (PRP), in sciatic nerve repair. Methods: Seventy male Wistar rats were randomly divided into five groups: IOVNF (Inside-Out Vein with No Filling); IOVPRP (Inside-Out Vein filled with PRP); SVNF (Standard Vein with No Filling); SVPRP (Standard Vein filled with PRP); Sham (Control). The left external jugular vein was used as graft in a 10 mm nervous gap. Results: In the morphological analysis of all groups, myelinated nerve fibers with evident myelin sheath, neoformation of the epineurium and perineurium, organization of intraneural fascicles and blood vessels were observed. In the morphometry of the distal stump fibers, SVPRP group had the highest means regarding fiber diameter (3.63±0.42 m), axon diameter (2.37±0.31 m) and myelin sheath area (11.70±0.84 m2). IOVPRP group had the highest means regarding axon area (4.39±1.16 m2) and myelin sheath thickness (0.80±0.19 m). As for values of the fiber area, IOVNF group shows highest means (15.54±0.67 m2), but are still lower than the values of the Sham group. Conclusion: The graft filled with platelet-rich plasma, with use standard (SVPRP) or inside-out vein (IOVPRP), promoted the improvement in axonal regeneration on sciatic nerve injury.(AU)

Perineal herniorrhaphy in dogs - literature review / Herniorrafia perineal em cães revisão de literatura

Perineal hernia occurs more frequently in non-castrated maledogs aged over five years. Surgical techniques for pelvicdiaphragm repair are varied, and can be employed aloneor associated with others and include the standard suturetechnique, transposition of the internal obturator muscle,transposition of the superficial gluteal muscle, transposition ofthe semitendinosus muscle, repair with synthetic or biologicalimplants, colopexy, and cistopexia. Associated postoperativecomplications are injury of the sciatic or pudendal nerve, fecalor urinary incontinence, rectal prolapse, infection, wounddehiscence, and hernia recurrence. Since it is a disease with highrates of complications and recurrences, we decided to conductthis review covering general aspects and the main treatmenttechniques of the disorder.

A hérnia perineal ocorre com maior frequência em cães machosnão castrados com idade superior a cinco anos. As técnicas cirúrgicasde reparação do diafragma pélvico são diversas, sendoempregadas de forma isolada ou associadas e incluem técnica desutura padrão, transposição do músculo obturador interno, transposiçãodo músculo glúteo superficial, transposição do músculosemitendinoso, reparação com uso de implantes sintéticos ou biológicos,colopexia e cistopexia. As complicações pós-operatóriasassociadas são: lesão do nervo isquiático ou pudendo, incontinênciafecal ou urinária, prolapso retal, infecção, deiscência de suturae recidiva da hérnia. Por ser uma enfermidade que apresentaelevados índices de complicações e recidivas, decidiu-se realizara presente revisão abordando os aspectos gerais e as principaistécnicas de tratamento da referida afecção.

Perineal herniorrhaphy in dogs - literature review / Herniorrafia perineal em cães revisão de literatura

Perineal hernia occurs more frequently in non-castrated maledogs aged over five years. Surgical techniques for pelvicdiaphragm repair are varied, and can be employed aloneor associated with others and include the standard suturetechnique, transposition of the internal obturator muscle,transposition of the superficial gluteal muscle, transposition ofthe semitendinosus muscle, repair with synthetic or biologicalimplants, colopexy, and cistopexia. Associated postoperativecomplications are injury of the sciatic or pudendal nerve, fecalor urinary incontinence, rectal prolapse, infection, wounddehiscence, and hernia recurrence. Since it is a disease with highrates of complications and recurrences, we decided to conductthis review covering general aspects and the main treatmenttechniques of the disorder.(AU)

A hérnia perineal ocorre com maior frequência em cães machosnão castrados com idade superior a cinco anos. As técnicas cirúrgicasde reparação do diafragma pélvico são diversas, sendoempregadas de forma isolada ou associadas e incluem técnica desutura padrão, transposição do músculo obturador interno, transposiçãodo músculo glúteo superficial, transposição do músculosemitendinoso, reparação com uso de implantes sintéticos ou biológicos,colopexia e cistopexia. As complicações pós-operatóriasassociadas são: lesão do nervo isquiático ou pudendo, incontinênciafecal ou urinária, prolapso retal, infecção, deiscência de suturae recidiva da hérnia. Por ser uma enfermidade que apresentaelevados índices de complicações e recidivas, decidiu-se realizara presente revisão abordando os aspectos gerais e as principaistécnicas de tratamento da referida afecção.(AU)

CONDUTO DE ORIENTAÇÃO NERVOSA FUNCIONALIZADO COM CÉLULAS ESTROMAIS MESENQUIMAIS MULTIPOTENTES PROMOVE A REGENERAÇÃO DO NERVO ISQUIÁTICO EM RATOS

As lesões traumáticas do sistema nervoso periférico (SNP) são altamente debilitantes, levando a déficits sensório-motores a longo prazo. A regeneração nervosa depende de um microambiente permissivo para o crescimento axonal, associado a presença de moléculas solúveis bioativas. Neste sentido, o uso das células estromais mesenquimais multipotentes derivadas do tecido adiposo (AdMSC) em combinação com condutos de orientação nervosa (NGC) poderiam acarretar estratégias promissoras para a regeneração nervosa. Ratos Wistar foram submetidos a lesão crítica do nervo isquiático (12 mm de gap) e divididos em grupos experimentais: Sham (abordagem do nervo isquiático sem alterações), GA (técnica de autoenxerto), GPCL (tubulação com NGC vazio), GPCL+MSCc (tubulação com NGC + 106 AdMSC de cão embebidas em biopolímero de fibrina) e GPCL+MSCr (tubulação com NGC + 106 AdMSC de rato embebidas em biopolímero de fibrina). Os NGC de policaprolactona (PCL) foram fabricados por impressão 3D. As AdMSC de cão foram caracterizadas in vitro e foi avaliado o potencial neuroregenerativo após a estimulação com INF-y (BDNF, GDNF, HGF e IL-10). Foram avaliados o índice de funcionalidade do nervo isquiático e tibial durante 12 semanas in vivo. A análise da marcha e a eletroneuromiografia foram avaliadas nas semanas 8 e 12. Foi realizada a morfometria post-mortem nas semanas 8 e 12 após o reparo nervoso. Trinta dias após a lesão nos grupos GPCL+MSCc e Sham, foram analisadas a expressão de fatores neurotróficos (BDNF, GDNF e o receptor p75NTR) e a reatividade das células de Schwann (S-100 e neurofilamento) pela imunofluorescencia, e a expressão gênica na medula espinhal (BDNF, GDNF, HGF, IL-6 e IL-10). A estimulação com INF-y aumentou a expressão gênica de BDNF, GDNF, HGF e IL-10 nas AdMSC de cão. Os grupos GPCL+MSCc e GPCL+MSCr apresentaram recuperação motora e eletrofisiológica quando comparados ao grupo GPCL em 8 e 12 semanas. Porém, os valores não foram superiores ao autoenxerto. Os achados foram relacionados a presença de fibras mielinizadas, maior expressão de BDNF, GDNF e P75NTR no nervo isquiático e a up-regulation de BDNF, GDNF e HGF na medula espinhal. Foi observada tendência a maior reatividade das células de Schwann e ramificação axonal no nervo isquiático. A combinação de NGC impressos em 3D e funcionalizados com AdMSC de cão e de rato mostraram efeitos neuroprotetores. A associação de AdMSC e biopolímero de fibrina suportaram o microambiente trófico e estimularam o estado pró-regenerativo na lesão crítica do nervo isquiático em ratos.

Peripheral nervous injuries (PNS) are highly debilitating, leading to long-term motor and sensory deficits. Nerve regeneration depends of the permissive microenvironment for axonal growth associated to bioactive molecules. In this sense, the use of multipotent mesenchymal stromal cells adipose tissue derived (AdMSC) in combination with nerve guidance conduits (NGC) could be promising strategies for nerve regeneration. Wistar rats were submitted to critical sciatic nerve injury (12 mm gap) and divided into experimental groups: Sham, GA (autograft), GPCL (empty NGC), GPCL + MSCc (NGC + 106 plus canine AdMSC embedded in fibrin biopolymer), GPCL + MSCr (NGC + 106 plus rat AdMSC embedded in fibrin biopolymer). Polycaprolactone (PCL) NGC was manufactured by 3D printing. In vitro, regenerative potential was evaluated after INF- stimulation (BDNF, GDNF, HGF and IL-10). In vivo, were measure the sciatic ant tibial functional index for 12 weeks. Gait analysis and electroneuromyography were performed at 8 and 12 weeks. Post-mortem, morphometric analysis was made at 8 and 12 weeks after nerve repair. Thirty days after lesion in the GPLC+MSCc and Sham, were evaluated the expression of neurotrophins (BDNF, GDNF and p75NTR receptor), Schwann cells reactivity by immunofluorescence (S-100 and neurofilament) and gene expression in the spinal cord (BDNF, GDNF, HGF, IL-6 and IL-10). The stimulation with INF- increased gene expression on canine AdMSC in vitro for BDNF, GDNF, HGF and IL-10. The groups GPCL+MSCc and GPCL+MSCr showed functional motor and electrophysiological motor recovery when compared with the GPCL group at 8 and 12 weeks. However, the values were not superior to GA group. These findings were related to presence of myelinated fibers, increased of neurotrophins expression BDNF, GDNF and p75NTR on sciatic nerve and up-regulation of the BDNF, GDNF and HGF in the spinal cord. A trend towards greater reactivity of Schwann cells and axonal branching in the sciatic nerve were observed. The combination of NGC 3D-printing and functionalized with canine and rat AdMSC showed neuroprotective effects. The association of canine or rat AdMSC and fibrin biopolymer support trophic microenvironment and stimulate a pro-regenerative state in severe sciatic nerve injury in rats.

Combined polyglycolic acid tube and autografting versus autografting or polyglycolic acid tube alone. A comparative study of peripheral nerve regeneration in rats

PURPOSE: To compare sciatic nerve regeneration in rats using three different techniques of repair. METHODS: Fifteen isogonics rats were divided into three groups according to the method used to repair a 5-mm long defect created in the sciatic nerve: autogenous graft (Group A), polyglycolic acid tube (PGAt) (Group B), and of the association of PGAt with the graft (Group C). Histological analysis, regenerated myelinated axon number count and functional analysis were used to compare after six weeks. RESULTS: There was no difference in fiber diameter and degree of myelinization presented by Groups A, B and C. Group B presented the lowest number of regenerated axons. The groups did not display any significant functional difference after walking track analysis (p<0.05). CONCLUSION: No differences between the three groups in terms of functional recovery, although there were histological differences among them.(AU)

Avaliação clínica e histopatológica da cicatrização do nervo ciático de coelhos (Oryctolagus cuniculus) submetidos à neurotmese e neurorrafia periférica com duas técnicas, associado ao uso de implantes de quitosana.

Os processos traumáticos são de grande importância na medicina veterinária, sendo as maiores casuísticas de atendimentos na clínica cirúrgica de pequenos animais, e dentro desses traumas, o envolvimento de lesões ao sistema nervoso é de grande preocupação devido a sua integridade conectiva com todos os outros sistemas. As lesões aos nervos periféricos podem trazer danos irreparáveis e comprometimento grave de funções dos membros quando não corrigidas adequadamente, principalmente devido a sua limitada capacidade de reparação. A reparação nervosa é um desafio na medicina, devido a isso algumas áreas da biologia e engenharia de materiais vem trabalhando em conjunto, para desenvolver produtos que possam promover a reparação de tecidos de difícil cicatrização. O primeiro capítulo do presente trabalho teve como objetivo avaliar técnicas cirúrgicas utilizadas na reparação de nervo periférico, e no segundo capítulo foi comparada a associação de implante a base de quitosana com a técnica com melhor resultado. Foram estudados dez coelhos (Oryctolagus cuniculus da família Leporidae, linhagem Nova Zelândia), hígidos, com idade aproximada de doze meses e peso entre 2,0 kg e 3,5 kg, submetidos à secção total do nervo ciático. Foram realizadas avaliações clínico-neurológicas e histopatológicas para avaliar o retorno funcional do membro e a progressão da cicatrização nervosa.

Traumatic processes retain great importance in veterinary medicine, with the largest number of cases being attended at the surgical clinic of small animals; and within these processes the involvement of injuries to the nervous system is a great concern due to its connective integrity with all other systems. Peripheral nerve damage can cause irreparable damage and severe impairment of limb function when not properly corrected, mainly because of its limited repair capacity. Nerve repair is a challenge in medicine, and some areas of biology and engineering have been working together, such as materials engineering, to develop products that can promote difficult tissue repair. The first chapter of the present study aimed to evaluate surgical techniques used in the repair the peripheral nerve, in the second chapter the association of chitosan based implant with the best result technique was compared. Ten rabbits (Oryctolagus cuniculus of the Leporidae family, New Zealand line), healthy, aged approximately twelve months and weighing between 2.0 kg and 3.5 kg, submitted to the total sciatic nerve section were studied. Clinical- neurological and histopathological evaluations were performed to evaluate functional limb return and progression of nerve healing.

A Catuama e o bilobalide na regeneração nervosa periférica de ratos submetidos à secção do nervo isquiático / Catuama and bilobalide on peripheral nerve regeneration in rats following sciatic nerve section

A Catuama® é a associação de quatro extratos hidroalcoolicos obtidos de plantas brasileiras (Paullinia cupana, Trichilia catigua, Ptychopetalum olacoides e Zingiber officinale) com conhecida ação neuroprotetora, anti-inflamatória, antioxidante e antidepressiva. O bilobalide é um componente extraído das folhas do Ginkgo biloba, que tem comprovada ação neuroprotetora nos sistemas nervosos central e periférico. O presente estudo avaliou os efeitos da Catuama® e do bilobalide na regeneração nervosa periférica de ratos submetidos à secção do nervo isquiático. Foram utilizados 40 ratos com implante de tubo de silicone preenchido por colágeno líquido, deixando-se um intervalo entre os segmentos nervosos de 10mm. Os animais foram divididos em 4 grupos: o grupo controle (A); os grupos que receberam a Catuama® administrada por via oral nos primeiros 28 dias de pós-operatório, nas doses de 100 (B) e 400mg.kg-1 (C); e o grupo que recebeu o bilobalide na dose de 200µM (D), este, adicionado ao colágeno líquido utilizado no implante de silicone. Os animais foram avaliados na primeira, quinta e décima semanas de pós-operatório pelo teste de marcha. Na décima semana, foi realizada avaliação eletrofisiológica e análises quantitativa e qualitativa dos cortes histológicos de amostras do nervo isquiático e do músculo gastrocnêmio. Em todas as análises utilizadas observou-se excelente regeneração dos nervos, no entanto, não foi encontrada diferença significativa (P>0,05) entre os grupos experimentais e controle.(AU)

The Catuama® is composed of four Brazilian plants extracts (Paullinia cupana, Trichilia catigua, Ptychopetalum olacoides e Zingiber officinale). The Catuama® is known as having neuroprotector, anti-inflammatory, antioxidant and antidepressant effects. Bilobalide, extracted from leaves of Ginkgo biloba, is known by its neuroprotective effect in the central and peripheral nervous systems. The present study evaluates the effect of Catuama® and bilobalide on peripheral nerve regeneration in rats following a sciatic nerve section. Sciatic nerve of forty adult rats was transected with a 10-mm gap and the proximal and distal nerve stumps were fixed in a silicone tube filled with liquid collagen. The animals were divided into four groups: the control group (A), two groups treated with Catuama® by gavage along 28 days after the surgery in different doses of 100 (B) and 400mg.kg-1 (C) and the group using 200µM bilobalide (D) associated with the liquid collagen in the silicone tube. Evaluations were done by a walk test on the first, fifth and tenth week after the surgery. Electrophysiological stimulation and quantitative and qualitative histological analyses of the sciatic nerve and gastrocnemius muscle were also performed on the tenth week after the surgery. All groups showed good regeneration but no statistical difference was found between treatments and control groups (P>0.05).(AU)

Sciatic nerve regeneration in rats by a nerve conduit engineering with a membrane derived from natural latex / Regeneração do nervo ciático em ratos através de um conduto confeccionado com uma membrana de látex natural

PURPOSE: To evaluate the capacity of natural latex membrane to accelerate and improve the regeneration quality of the of rat sciatic nerves. METHODS: Forty male adult Wistar rats were used, anesthetized and operated to cut the sciatic nerve and receive an autograft or a conduit made with a membrane derived from natural latex (Hevea brasiliensis). Four or eight weeks after surgery, to investigate motor nerve recovery, we analyzed the neurological function by walking pattern (footprints analysis and computerized treadmill), electrophysiological evaluation and histological analysis of regenerated nerve (autologous nerve graft or tissue cables between the nerve stumps), and anterior tibial and gastrocnemius muscles. RESULTS: All functional and morphological analysis showed that the rats transplanted with latex conduit had a better neurological recovery than those operated with autologous nerve: quality of footprints, performance on treadmill (p<0.01), electrophysiological response (p<0.05), and quality of histological aspects on neural regeneration. CONCLUSION: The data reported showed behavioral and functional recovery in rats implanted with latex conduit for sciatic nerve repair, supporting a complete morphological and physiological regeneration of the nerve.(AU)

OBJETIVO: Avaliar a capacidade de uma membrana de látex natural em acelerar e melhorar a qualidade da regeneração do nervo ciático seccionado de ratos. MÉTODOS: Foram utilizados 40 ratos machos adultos da linhagem Wistar, anestesiados e operados com autoenxerto ou com interposição de um tubo confeccionado com uma membrana derivada do latex natural (Havea brasiliensis). Quatro ou oito semanas após a cirurgia, para investigar a recuperação motora do nervo, foram analisadas a função neurológica através do padrão da marcha (análise das pegadas e esteira computadorizada), avaliação eletrofisiológica e análise histológica do nervo regenerado (enxerto de nervo autólogo ou formação de nervo novo entre os cotos nervosos) e músculos gastrocnêmio e tibial anterior. RESULTADOS: Todas as análises morfológicas e funcionais demonstraram que os ratos transplantados com o conduto de látex tiveram recuperação melhor do que aqueles operados com nervo autólogo: qualidade das pegadas impressas, desempenho em esteira (p<0,01), resposta eletrofisiológica (p<0,05), e qualidade histológica da regeneração nervosa. CONCLUSÃO: Os dados apresentados demonstraram recuperação comportamental e funcional nos ratos implantados com o conduto de látex para a reparação do nervo ciático por meio de uma completa regeneração morfológica e fisiológica do nervo.(AU)

Nerve growth factor with fibrin glue in end-to-side nerve repair in rats / Fator de crescimento nervoso em cola de fibrina no reparo término-lateral de nervos em ratos

PURPOSE: To determine the effects of end-to-side nerve repair performed only with fibrin glue containing nerve growth in rats. METHODS: Seventy two Wistar rats were divided into six equal groups: group A was not submitted to nerve section; group B was submitted to nerve fibular section only. The others groups had the nerve fibular sectioned and then repaired in the lateral surface of an intact tibial nerve, with different procedures: group C: ETS with sutures; group D: ETS with sutures and NGF; group E: ETS with FG only; group F: ETS with FG containing NGF. The motor function was accompanied and the tibial muscle mass, the number and diameter of muscular fibers and regenerated axons were measured. RESULTS: All the analyzed variables did not show any differences among the four operated groups (p>0.05), which were statistically superior to group B (p<0.05), but inferior to group A (p>0.05). CONCLUSION: The end-to-side nerve repair presented the same recovery pattern, independent from the repair used, showing that the addition of nerve growth factor in fibrin glue was not enough for the results potentiating.(AU)

OBJETIVO: Determinar os efeitos do reparo nervoso término-lateral realizado apenas com cola de fibrina contendo fator de crescimento nervoso em ratos. MÉTODOS: Setenta e dois ratos Wistar foram distribuídos em seis grupos: A - não submetido à secção nervosa; B - secção do nervo fibular (sem reparo); Os outros grupos tiveram o nervo fibular seccionado e então reparado na superfície lateral do nervo tibial intacto, com diferentes procedimentos: C - RNTL com suturas; D - RNTL com suturas e FCN; E - RNTL apenas com CF; F - RNTL com CF contendo FCN. A função motora foi acompanhada e a massa do músculo tibial, o número e o diâmetro das fibras musculares e axônios regenerados foram medidos. RESULTADOS: Não houve diferença entre as variáveis avaliadas nos quatro grupos operados (p>0,05), os quais foram superiores ao grupo B (p<0,05), mas inferiores ao grupo A (p>0,05). CONCLUSÕES: O reparo nervoso término-lateral mostrou o mesmo padrão de recuperação, independente do tipo de reparo utilizado, evidenciando que a adição de fator de crescimento nervoso na cola de fibrina não foi suficiente para a potencialização dos resultados.(AU)

End-to-side nerve repair using fibrin glue in rats / Anastomose nervosa término-lateral usando cola de fibrina em ratos

Purpose: To evaluate axonal regeneration after end-to-side nerve repair with fibrin glue in rats. Methods: Forty-five Wistar rats were divided into three groups: group A (n=15), were not submitted to surgery (control group); group B (n=15) were submitted to fibular transection without repair; and group C (n=15), were submitted to fibular transection with end-to-side nerve anastomosis using fibrin glue, in the lateral surface of an intact tibial nerve. The three groups were submitted to walking track (30 and 90 days) and posterior morphometrical analysis (90 days). Results: The functional tests demonstrated that there was no difference in the walking track during the study in group A (p>0.05). The group B had walking pattern impairment in the two tests (p>0.05). The group C had walking pattern impairment in the first test, with important recovery in the second test (p<0.05). The morphometrical assessment revealed significantly higher number of regenerated mielinates axons in group C, compared to group B (p<0.05). Conclusion: The end-to-side nerve repair with fibrin glue shows axonal recovery, demonstrated through functional and morphometrical ways in rats.(AU)

Objetivo: Avaliar a regeneração axonal após anastomose nervosa término-lateral (ATL) usando cola de fibrina em ratos. Métodos: Quarenta e cinco ratos Wistar distribuídos em três grupos: os animais do grupo A (n=15) não foram submetidos à secção nervosa (grupo controle); os animais do grupo B (n=15) foram submetidos apenas à secção do nervo fibular, sem posterior anastomose; e os animais do grupo C (n=15) foram submetidos à secção do nervo fibular e à ATL com cola de fibrina no nervo tibial. Posteriormente, os animais foram submetidos a dois testes de marcha (30 e 90 dias) e à análise morfométrica (90 dias). Resultados: A análise estatística dos testes de marcha demonstrou que o grupo A não apresentou alteração no padrão de caminhada durante o estudo (p>0,05). O grupo B apresentou prejuízo motor no primeiro e no segundo teste (p>0,05). O grupo C apresentou um padrão de atrofia no primeiro teste, com recuperação da marcha no segundo teste (p<0,05). Na análise morfométrica, o grupo C apresentou regeneração axonal significativamente superior ao grupo B (p<0,05). Conclusão: A ATL realizada com cola de fibrina resultou em regeneração axonal no rato, demonstrada tanto histologicamente quanto funcionalmente.(AU)

Neurorrafia do ramo bucal dorsal do nervo facial em coelhos com proteção de segmento intestinal alógeno / Neurorrhaphy of the dorsal buccal branch of facial nerve in rabbits with protection o f allograft intestinal segment

Foram utilizados 18 coelhos, Nova Zelândia, machos, adultos, para avaliação clínica e histológica do reparo do ramo bucal dorsal do nervo facial, decorridos 15, 30 e 60 dias de pós-operatório (PO). Os animais foram distribuídos em dois grupos para secção e aproximação epineural do ramo bucal com fio náilon monofilamentoso 10-0. Nos animais do grupo I, o nervo foi revestido com proteção de segmento de jejuno alógeno conservado em glicerina a 98% e o grupo II apenas aplicação de sutura epineural. Nos coelhos dos dois grupos ocorreu retorno da movimentação do lábio superior a partir da oitava semana.Verificou-se infiltrados celulares e células gigantes com fibrose desorganizada e fibras colágenas do envoltório alógeno entremeadas ao tecido conjuntivo. Aos 15 e 30 dias de PO, os cotos distais deambos os grupos encontravam-se com degeneração walleriana e aos 60 dias, com fibras regeneradas. A reparação do ramo bucal dorsal do nervo facial com o segmento intestinal não foi significativamente diferente nos coelhos do controle, quanto à avaliação de recuperação funcional e histológica.(AU)

18 rabbits, New Zealand, males, adults were used for clinical and histological evaluation of repair dorsal buccal branch of facial nerve after 15, 30 and 60 days postoperatively (PO). The animals were divided into two groups for transection and 10-0 nylon monofilament epineural suture of buccal branch. In animals in Group I, the nerve was coated with protection of jejunum allograft preserved in glycerin 98% and in group II was applied epineural suture. Both groups occurred the return of movement of the upper lip from the eighth week. There was infiltrated cellular and giant cells with fibrosis unsystematic and collagen fibers of the allograft jejunum joing to the connective tissue. At 15 and 30 days of PO, the distal nerve stumps of both groups were found with degeneration wallerian and in 60 days, regenerated fibers. The repair of the dorsal buccal branch offacial nerve with the allograft wasnt significantly different between the control rabbits as to the assessment of histological and functional recovery.(AU)

Utilização de células-tronco autólogas de medula óssea na regeneração do nervo tibial de coelhos mediante técnica de tubulização com prótese de silicone

This study presents an experimental model of an acute deffect in a peripheral nerve to evaluate neural regeneration using a tubulization technique associated with the inoculation of autologous stem cells from bone marrow. A total of 12 New Zealand white rabbits underwent a bilateral dissection of the tibial nerve followed by repair with silicone tubulization. On the left tibial nerve of all animals, the tube was filled with autologous bone marrow-derived stem cells collected from the humerus. For control, using the same repair technique, the tubes were filled with a NaCl solution in the right tibial nerve. After 30 days of observation, the animals were euthanized and a histological evaluation of the collected nerve segments was performed by staining with hematoxylin-eosin, luxol fast blue, and toluidine blue. From the results it is possible to conclude that the transplanted autologous stem cells associated with the tubulization technique present an advantage in the peripheral nerve regeneration process.

Neste estudo é apresentado um modelo experimental de defeito agudo em nervo periférico para avaliação da regeneração nervosa mediante técnica de tubulização associada à inoculação de células-tronco autólogas de medula óssea. Foram utilizados 12 coelhos Nova Zelândia albinos, submetidos à secção bilateral e ao afastamento de 5mm do nervo tibial e posterior reparo mediante utilização de câmara de silicone. Internamente à prótese de tubulização do nervo tibial esquerdo em todos os animais, foram inoculadas células-tronco autólogas de medula óssea, coletadas a partir do úmero. Como grupo controle (nervo tibial direito), mediante aplicação da mesma técnica de reparo, solução de NaCl 0,9% foi administrada internamente à prótese. Após 30 dias de observação, os animais foram eutanasiados e foi realizada a avaliação histológica dos segmentos nervosos por meio das colorações de hematoxilina-eosina, luxol fast blue e azul de toluidina. Com os resultados, foi possível concluir que o transplante de células-tronco autólogas associado à técnica de tubulização apresenta vantagens no processo de regeneração nervosa periférica.

Utilização de células-tronco autólogas de medula óssea na regeneração do nervo tibial de coelhos mediante técnica de tubulização com prótese de silicone

This study presents an experimental model of an acute deffect in a peripheral nerve to evaluate neural regeneration using a tubulization technique associated with the inoculation of autologous stem cells from bone marrow. A total of 12 New Zealand white rabbits underwent a bilateral dissection of the tibial nerve followed by repair with silicone tubulization. On the left tibial nerve of all animals, the tube was filled with autologous bone marrow-derived stem cells collected from the humerus. For control, using the same repair technique, the tubes were filled with a NaCl solution in the right tibial nerve. After 30 days of observation, the animals were euthanized and a histological evaluation of the collected nerve segments was performed by staining with hematoxylin-eosin, luxol fast blue, and toluidine blue. From the results it is possible to conclude that the transplanted autologous stem cells associated with the tubulization technique present an advantage in the peripheral nerve regeneration process.

Neste estudo é apresentado um modelo experimental de defeito agudo em nervo periférico para avaliação da regeneração nervosa mediante técnica de tubulização associada à inoculação de células-tronco autólogas de medula óssea. Foram utilizados 12 coelhos Nova Zelândia albinos, submetidos à secção bilateral e ao afastamento de 5mm do nervo tibial e posterior reparo mediante utilização de câmara de silicone. Internamente à prótese de tubulização do nervo tibial esquerdo em todos os animais, foram inoculadas células-tronco autólogas de medula óssea, coletadas a partir do úmero. Como grupo controle (nervo tibial direito), mediante aplicação da mesma técnica de reparo, solução de NaCl 0,9% foi administrada internamente à prótese. Após 30 dias de observação, os animais foram eutanasiados e foi realizada a avaliação histológica dos segmentos nervosos por meio das colorações de hematoxilina-eosina, luxol fast blue e azul de toluidina. Com os resultados, foi possível concluir que o transplante de células-tronco autólogas associado à técnica de tubulização apresenta vantagens no processo de regeneração nervosa periférica.

Implante de tubo de silicone com e sem colágeno na regeneração de nervos em eqüinos

Surgical nerve repair in humans, dogs and laboratory animals is widely utilized for important clinical and experimental purposes. However, in horses there is scarce information. Neuroma and excessive conjunctive proliferation are reported. The aim of the present study was to add information about the repair process utilizing implant of silicone tubes with or without collagen in nerve regeneration of horses. Eight horses were allocated in two groups: GI-13 weeks and GII-26 weeks of observation. A complete section of the ulnar nerves (UNs) and of the lateral cutaneous branch of the 17th thoracic nerves (TNs), bilaterally, was followed by repair with silicone tubes alternately filled with (STC) or without collagen (ST), with a 5mm gap between stumps. Clinical evaluation was performed weekly, by cutaneous sensitivity testing of the region innervated by the respective operated nerves and physical examination of the thoracic limbs. No alterations were found in the locomotor apparatus. The first positive reactions to the cutaneous test occurred at the 9th week post-surgery. At the end of the observation period it was verified, grossly, that the nerves were involved by conjunctive tissue and the lumen of the tube was filled by a whitish tissue, in a cylindrical shape. The ends nerves were interconnected. Microscopically, myelinated axons and Schwann cells were present in the gap between the stumps. In the GII the number of myelinated fibers was greater. The distal nerve showed remyelination process. There was no presence of neuroma and the inflammatory process was limited to the perineural areas. It was concluded that the implant of silicone tubes results in regeneration of UNs and TNs of horses without formation of neuromas and that de addition of collagen promotes an increase in the number of myelinated fibers.

A reconstituição cirúrgica de nervos em humanos, em cães e em diversos animais de laboratório é bastante utilizada e tem indicações clínicas e experimentais importantes. No entanto, em eqüinos há poucas informações sobre esta prática. Há relatos sobre a excessiva proliferação de tecido conjuntivo e a formação de neuromas à neurorrafia experimental, mesmo quando se utilizam tubos de silicone para condução do crescimento axonal. O presente estudo teve o objetivo de acrescentar informações sobre o processo de reparação de nervos periféricos em eqüinos por meio de implante de tubo de silicone preenchido ou não com colágeno. Para tanto, foram utilizados oito eqüinos, alocados em dois grupos: GI-13 semanas e GII-26 semanas de observação. Foi realizada secção dos nervos ulnares (NUs) e dos ramos cutâneos laterais dos 17° nervos torácicos (NTs), bilateralmente, seguindo tubulização, realizada em cada animal, alternando-se tubos de silicone vazios (TS), em um dos antímeros, ou preenchidos com solução de colágeno (TSC), no contralateral, deixando-se um espaço de 5mm entre os cotos. Nenhuma alteração foi encontrada ao exame do aparelho locomotor e as primeiras reações positivas ao teste de sensibilidade cutânea nos NUs e NTs com TS e TSC foram observadas a partir da 9ª semana, em ambos os grupos. Ao final do período de observação, verificou-se, macroscopicamente, que os nervos encontravam-se envolvidos por tecido conjuntivo e o interior da câmara estava preenchido por tecido de coloração esbranquiçada, de forma cilíndrica, interligando os cotos proximal e distal. Microscopicamente, constatou-se a presença de axônios mielinizados interligando os cotos, as células de Schwann e o processo de remielinização do coto distal, principalmente no TSC. Em ambos os grupos, não houve formação de neuromas e o processo inflamatório limitou-se às áreas perineurais. Concluiu-se que o implante de tubo de silicone conduz à regeneração de NUs e NTs de eqüinos sem formação de neuromas e que a adição de colágeno promove aumento do número de fibras mielinizadas.