Glucose metabolism in rats submitted to skeletal muscle denervation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito analgésico de longa duração da dipirona sobre a hiperalgesia persistente induzida pela constrição do nervo ciático em ratos: participação do óxido nítrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metabolismo glicídico em ratos submetidos a desnervação do músculo esquelético e ao exercício de natação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Parâmetros da marcha em portadores de diabetes mellitus

O Diabetes mellitus é uma enfermidade crônica que leva a alterações sensitivas e motoras. Tais alterações comprometem o equilíbrio e a deambulação, predispondo seus portadores à ocorrência de quedas. Esta revisão teve por objetivo levantar, na literatura recente, estudos que visassem avaliar parâmetros da marcha e aspectos envolvidos com a deambulação. Para isso, foi realizada uma busca nas bases de dados MEDLINE, SciELO, LILACS e PEDro, cruzando as palavras-chave: Neuropatias Diabéticas x Marcha; Diabetes Mellitus x Marcha e Pé Diabético x Marcha. Após passarem pelos critérios de seleção, foram obtidos 15 artigos, os quais foram sintetizados e discutidos, sendo, portanto, incluídos nesta revisão. Ficou claro que a neuropatia diabética leva a déficits na amplitude do passo, velocidade e cadência da marcha em superfícies planas, sem mudanças bruscas de direção ou paradas, e déficits de equilíbrio e coordenação em aclives, declives e terrenos irregulares. Acarreta, também, aumento dos índices de pressão plantar e, devido à alteração de ativação do tríceps sural, dificuldade na fase de apoio terminal e pré-balanço. Assim, o próximo contato inicial ocorrerá de maneira inadequada, com o antepé e sem absorção de choques.

Caracterização de um modelo experimental de neuropatia em ratos diabéticos induzidos pela aloxana

Cem ratos norvégicus, machos, com aproximadamente 3 meses de idade foram distribuídos por sorteio em 2 grupos experimentais: Grupo Controle (GC): com 50 ratos sadios, não diabéticos e Grupo Diabético (GD): com 50 ratos diabéticos, induzidos pela aloxana, sem qualquer tratamento. Cada grupo foi dividido em 5 subgrupos com 10 ratos cada e sacrificados com 1, 3, 6, 9 e 12 meses de seguimento, respectivamente. Parâmetros clínicos (peso, ingestão hídrica e alimentar, e diurese) e laboratoriais (glicemia, glicose urinária e insulina) foram documentados em todos os momentos de avaliação. Um segmento do nervo ciático foi obtido de cada animal, em ambos os grupos, para estudo à MO. e ME. Alterações clínicas e laboratoriais significativas (P<0,01), compatíveis com diabetes grave, foram observadas em todos os animais do GD a partir do 4o dia após a indução. Ratos de ambos os grupos apresentaram alterações no número de fibras mielínicas e nos depósitos intraaxonais de glicogênio que não diferiram, estatisticamente, aos 1, 3 e 6 meses de seguimento. Entretanto, aos 9 e 12 meses, ratos do GD apresentaram diminuição significativa no número de fibras mielínicas, com aumento do número de fibras mielínicas de menor calibre, quando comparados com ratos do GC (P<0,05). Grânulos de glicogênio intraaxonais também foram mais acentuados em ratos do GD no 9o e 12o mês de seguimento. Não foram observadas diferenças na densidade de fibras amielínicas ou alterações ultraestruturais significativas entre os dois grupos, em relação aos espaços intraaxonais e endoneurais, bainhas de mielina e células de Schwann durante todo o estudo.

Estudo das relações anatômicas e suas variações entre o nervo ciático e o músculo piriforme

CONTEXTO: A síndrome do músculo piriforme pode ter como causa a passagem anormal do nervo ciático ou de uma de suas partes pelo ventre do músculo piriforme. OBJETIVO: Analisar as relações anatômicas e métricas entre o músculo piriforme e o nervo ciático, contribuindo com o conhecimento anátomo-clínico da região glútea. MÉTODO: Foram utilizados 20 cadáveres adultos de ambos os sexos. O nervo ciático e o músculo piriforme foram dissecados, medidos e fotodocumentados. RESULTADOS: Observou-se que 85% das 40 regiões glúteas apresentaram o nervo como tronco único, passando pela borda inferior do músculo piriforme, e 15% mostraram uma variação bilateral, caracterizada pela passagem do nervo fibular comum através do músculo piriforme. Os dados obtidos não revelaram diferenças estatisticamente significantes.

Effects of nandrolone decanoate on the neuromuscular junction of rats submitted to swimming

This study addressed the effects of nandrolone decanoate (ND) on contractile properties and muscle fiber characteristics of rats submitted to swimming. Male Wistar rats were grouped in sedentary (S), swimming (Sw), sedentary+ND (SND), and swimming+ND (SwND), six animals per group. ND (3 mg/kg) was injected (subcutaneously) 5 days/week, for 4 weeks. Swimming consisted of 60-min sessions (load 2%), 5 days/week, for 4 weeks. After this period, the sciatic nerve extensor digitorum longus (EDL) muscle was isolated for myographic recordings. Fatigue resistance was assessed by the percent (%) decline of 180 direct tetanic contractions (30 Hz). Safety margin of synaptic transmission was determined from the resistance to the blockade of indirectly evoked twitches (0.5 Hz) induced by pancuronium (5 to 9 x 10(-7) M). EDL muscles were also submitted to histological and histochemical analysis (haematoxylin-eosin (HE); nicotinamide adenine dinucleotide-tetrazolium reductase (NADH-TR)). Significant differences were detected by two-way ANOVA (p<0.05). ND did not change body mass, fatigue resistance or kinetic properties of indirect twitches in either sedentary or swimming rats. In contrast, ND reduced the safety margin of synaptic transmission in sedentary animals (SND=53.3+/-4.7% vs. S=75.7+/-2.0%), but did not affect the safety margin in the swimming rats (SwND=75.81+/-3.1% vs. Sw=71.0+/-4.0%). No significant difference in fiber type proportions or diameters was observed in EDL muscle of any experimental group. These results indicate that ND does not act as an ergogenic reinforcement in rats submitted to 4 weeks of swimming. on the other hand, this study revealed an important toxic effect of ND, that it reduces the safety margin of synaptic transmission in sedentary animals. Such an effect is masked when associated with physical exercise. (C) 2004 Elsevier B.V. All rights reserved.

Cauda equina syndrome after spinal tetracaine: Electromyographic evaluation-20 years follow-up

CAUDA equina syndrome (CES) has long been recognized as a rare complication of spinal anesthesia.(1) CES has been described after administration of spinal anesthetics with lidocaine(2) and bupivacaine.(3) In 1991,(4) CES was reported after continuous spinal anesthesia with 1% tetracaine. In 1980, at our university hospital, six adult female patients underwent perineal gynecologic surgery using a spinal anesthetic of 2 ml tetracaine, 1.2%, in 10% glucose. The concentration of the injected tetracaine was unknown by the anesthetists. In all cases, lumbar puncture was performed at the L3-L4 interspace with a disposable spinal needle while the patients were in the sitting position. CES was first diagnosed 72 h or later postoperatively; previous diagnosis was not possible because patients had an indwelling urethral catheter. The diagnosis of CES was confirmed in all patients. During the past year, after institutional approval and informed consent, clinical, magnetic resonance imaging, electromyographic examinations, and conduction studies were performed in three of the above patients. Examinations were not possible on the other three patients because one had recently died, another could not be located, and the third refused to participate. T1 and T2 magnetic resonance image readings were obtained with Gadolinium contrast from a 0.5 Tesla General Electric apparatus (General Electric, Tokyo, Japan). Bilateral sensory and motor conduction studies of the sciatic nerve branches were obtained using a two-channel Nihon-Kohden Neuropack 2 (Nihom-Kohden Corporation, Tokyo, Japan). Electromyography was performed in accordance with conventional techniques.(5,6)

Plant derived alkaloid (-)-cassine induces anti-inflammatory and anti-hyperalgesics effects in both acute and chronic inflammatory and neuropathic pain models

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The analgesic effect of crotoxin on neuropathic pain is mediated by central muscarinic receptors and 5-lipoxygenase-derived mediators

Crotoxin (CTX). a neurotoxin isolated from the venom of the South American rattlesnake Crotalus durissus terrificus. induces analgesia. In this study, we evaluated the antinociceptive effect of CTX in a model of neuropathic pain induced by rat sciatic nerve transection. Hyperalgesia was detected 2 h after nerve transection and persisted for 64 days. Immersion of proximal and distal nerve stumps in CTX solution (0.01 mM for 10 s), immediately after nerve transection, blocked hyperalgesia. The antinociceptive effect of CTX was long-lasting, since it was detected 2 h after treatment and persisted for 64 days. CTX also delayed, but did not block, neurectomy-induced neuroma formation. The effect of CTX was blocked by zileuton (100 mg/kg, p.o.) and atropine (10 mg/kg. i.p.), and reduced by yohimbine (2 mg/kg, i.p.) and methysergide (5 mg/kg, i.p.). on the other hand. indomethacin (4 mg/kg, i.v.). naloxone (1 mg/kg, i.p.). and N-methyl atropine (30 mg/kg, i.p.) did not interfere with the effect of CTX. These results indicate that CTX induces a long-lasting antinociceptive effect in neuropathic pain, which is mediated by activation of central muscarinic receptors and partially, by activation of alpha-adrenoceptors and 5-HT receptors. Eicosanoids derived from the lipoxygenase pathway modulate the action of crotoxin. (C) 2008 Elsevier B.V. All rights reserved.

Nerve grafts prevent paraplegic pressure ulcers

We present an optimistic neural solution to the depressing challenge of decubitus pressure ulcers in the paraplegic patient. This is a limited study of two paraplegic men followed for several years. Sural nerve grafts, performed end-to-side, successfully bridged the sciatic nerve to intercostal nerves with surprising benefits for both men.

Comparison of three systems of classification in predicting the outcome of diabetic foot ulcers in a Brazilian population

Objective: The aim was to compare there ulcer classification systems as predictors of the outcome of diabetic foot ulcers; the Wagner, the University of Texas (UT) and the size (area, depth), sepsis, arteriopathy, denervation system (S(AD)SAD) systems in specialist clinic in Brazil.Methods: Ulcer area, depth, appearance, infection and associated ischaemia and neuropathy were recorded in a consecutive series of 94 subjects. A novel score, the S(AD)SAD score, was derived from the sum of individual items of the S(AD)SAD system, and was evaluated. Follow-up was for at least 6 months. The primary outcome measure was the incidence of healing.Results: Mean age was 57.6 years; 57 (60.6%) were made. Forty-eight ulcers (51.1%) healed without surgery; 11 (12.2%) subjects underwent minor amputation. Significant differences in terms of healing were observed for depth (P = 0.002), infection (P = 0.006) and denervation (P = 0.002) using the S(AD)SAD system, for UT grade (P = 0.002) and stage (P = 0.032) and for Wagner grades (P = 0.002). Ulcers with an S(AD)SAD score of <= 9 (total possible 15) were 7.6 times more likely to heal than scores >= 10 (P < 0.001).Conclusions: All three systems predicted ulcer outcome. The S(AD)SAD score of ulcer severity could represent a useful addition to routine clinical practice. The association between outcome and ulcer depth confirms earlier reports. The association with infection was stronger than that reported from the centres in Europe or North America. The very strong association with neuropathy has only previously been observed in Tanzania. Studies designed to compare the outcome in different countries should adopt systems of classification, which are valid for the populations studied.

ESTUDO DO EFEITO DE GANGLIOSIDEOS EXOGENOS NA REGENERACAO NERVOSA APOS COMPRESSAO E NEURORRAFIA NO NERVO CIATICO DO RATO

The authors studied the possible inductive effect of exogenous gangliosides administrated intra-peritoneal and intra-muscular, in 33 rats, after compression and sutures of sciatic nerve. In the animals suffering compression of the sciatic nerve only, the myelin sheath was preserved with good regeneration of the nerve. There was no statistics difference between the two groups with or without the administration of gangliosides. In the group of rats where section of the sciatic nerve and suture were performed, neuroma of amputation as well as dense cicatricial tissue with inflammatory reaction of foreign body type was noted around the sutures. In conclusion, the formation of neuroma of amputation associated with severe inflammatory reaction had an important role in determining the regeneration of the nerve.

ASPECTOS ETIOLOGICOS DA HIPERNASALIDADE CONSEQUENTE A PARALISIA DE PALATO MOLE - RELATO DE 6 CASOS

The authors studied the main aspects of etiology of the palate paralysis in six children suffering from soft palate paralysis. They emphasized the importance of multidisciplinary approach in the management of patients with this disease. In the author's cases the most likely etiologies were: neuropathy post-viral epidemic parotitis, tumors localized in the posterior cerebral fossa and idiopathic. They concluded that it is extremely important in these patients a detailed otorhinolaryngologic, neurologic and fonoaudiologic examinations.

Distúrbios neurológicos em trabalhadores com baixos níveis de chumbo no sangue. I: Neuropatia periférica

This is a cross-sectional study with a randomized choice of individuals aiming at studying the validity of the Brazilian biological exposure limits applied to lead level in the blood (PbB) and delta-aminolevulinic acid in the urine (ALAU), which are 60 μg/dl and 10 mg/g.creat., respectively. For this purpose, twenty workers, whose PbB and ALAU values have been below these limits over the past two years, were selected at random at a battery production plant in the State of S. Paulo, Brazil. The workers were submitted to a peripheral nerve conduction study. The results were compared with those obtained for workers of a control group also chosen at random. The lead workers showed a decrease in the velocity conduction of the radial nerves. Comparing this group with a randomized control group, a significant difference was observed (p-value = 0.0067). The results suggest that the Brazilian biological exposure limits above should be rearranged.