The effect of the aerobic training on morphological and histochemical characteristics of tibial anterior muscle in rats fed with high fat diet

The aim of this study was to investigate the effect of high fat diet and different frequencies of swimming programs in the tibial anterior muscle in male Wistar rats. In conclusion, the aerobic training during two days/week and five days/week caused injuries in muscle fibers and the high fat diet did not cause statically significant results compared to normal diet.

El objetivo de este estudio fue investigar el efecto de dietas ricas en grasas y diferentes frecuencias de natación, en el músculo tibial anterior, de ratas machos Wistar. El entrenamiento aeróbico, durante dos y cinco días por semana, causó lesiones en las fibras musculares y la dieta alta en grasa, no produjo resultados estadísticamente significativos, en comparación con la dieta normal.

Fixação de enxerto cutâneo em malha de espessura total com sutura ou cola de fibrina / Fixation of full-thickness mesh skin using suture or fibrin glue

Avaliou-se a influência da cola de fibrina, derivada do veneno de serpente, na fixação e integração de enxerto de pele. Foram utilizados nove cães, sem raça definida, com peso médio de 15kg. Foi induzida ferida de 4I4cm de área, na face crânio-proximal dos antebraços direito e esquerdo. Um enxerto de espessura total foi colhido da região torácica e expandido por meio de expansor de pele. No membro direito o enxerto foi estabilizado no leito receptor por meio de pontos isolados simples; no esquerdo foi fixado pela aplicação de cola de fibrina e oito pontos de sutura. O sítio doador foi fechado empregando-se retalho cutâneo bipediculado. As bandagens do leito receptor foram oclusivas e não aderentes e aplicou-se pomada de neomicina com bacitracina. A troca de bandagens ocorreu diariamente até o sétimo dia de pós-operatório e, posteriormente, a cada três dias. A área de sobrevivência do enxerto foi obtida pela subtração das áreas não viáveis e total medidas com fotomicroscópio Nikon conectado a um sistema de análise de imagem KS-300 aos três, sete, 15 e 30 dias de pós-operatório. Para a avaliação microscópica, a área do enxerto foi colhida em três animais aos sete, 15 e 30 dias de pós-operatório. Não houve diferença entre momentos de avaliação e técnicas de fixação quanto à área de enxerto viável. Os enxertos fixados com cola apresentaram estágio de reparação mais avançado em todos os momentos. Concluiu-se que a cola de fibrina derivada do veneno de serpente tem moderado poder adesivo e, pela análise microscópica, favorece a integração do enxerto cutâneo em malha de espessura total.

Morphological aspects of muscle regeneration in the Nile tilapia (Oreochromis niloticus).

The aim of our study was to analyze the morphological events in the skeletal muscle of the Nile tilapia (Oreochromis niloticus) after a traumatic lesion. Thirty-two fish were used, on which a small longitudinal incision was made in the muscle. The fish were sacrificed after 7, 14, 21, and 42 days and muscle samples were collected from the lesion and processed for morphological analysis. Muscle regeneration in the tilapia occurred gradually through the analyzed period, possibly due to the proliferation and differentiation of myosatellite cells, which were more morphologically evident 7 and 14 days after lesion.

Muscle growth in Nile tilapia (Oreochromis niloticus): histochemical, ultrastructural and morphometric study.

Muscle growth in Nile tilapia (Oreochromis niloticus) was studied focusing on histochemical, ultrastructural, and morphometric characteristics of muscle fibers. Based on body length (cm), we studied four groups: G1=1.36+/-0.09, G2=3.38+/-0.44, G3=8.90+/-1.47, and G4=28.30+/-3.29 (mean+/-S.D.). All groups showed intense reaction to NADH-TR in subdermal fibers and weak or no reaction in deep layer fibers. In G3 and G4, an intermediate layer was also observed with fibers presenting weak reaction; in G4, groups of fibers with intense reaction were observed in the subdermal region. The myosin ATPase (m-ATPase) activities were acid-stable and alkali-labile in subdermal fibers; most deep layer fibers were alkali-stable and acid-labile. Intermediate fibers were acid-labile and alkali-stable. Two fiber populations were observed near deep muscle layer: one large presenting weak acid- and alkali-stable and the other small alkali-stable. During growth, muscle fiber hypertrophy was more evident in intermediate and white fibers for G3 and G4. However, in these groups, the presence of fiber diameters < or =21 microm suggested that there is still substantial fiber recruitment, confirmed by ultrastructural study, but hypertrophy is the main mechanism contributing to increase in muscular mass.

Morphological, histochemical and morphometric study of the myotomal muscle tissue of the pacu (Piaractus mesopotamicus Holmberg 1887: Serrasalminae, Characidae, Teleostei).

Histochemical, ultrastructural and morphometric methods were used to study growth patterns of red, pink and white muscle fibres and their relation to body weight and total length in the fast-growing freshwater fish Piaractus mesopotamicus Holmberg. The correlations amongst body weight, body length and diameter of red, pink and white fibres were low. From 10-15 to 40-50 cm, body weight increased 102.7 times, while the diameter of each type of fibre increased by factors of 0.94, 0.74 and 0.70, respectively. Muscle fibres revealed different morphological and histochemical stages of maturation. The frequencies of < 20 microns fibres of red, pink and white muscle tissue in the youngest and oldest classes were 64.5 and 11.0, 38.2 and 7.7 and 24.0 and 1.4%, respectively. In 30-40 cm fish, the frequency of < 20 microns fibres in the red and pink tissue was 24.5 and 25.5%, while in the white tissue it was 11.5%. During sexual maturity (40-50 cm), the recruitment of < 20 microns fibres in white muscle was 1.4%. Muscle fibres of this species showed continuous growth by both hyperplastic and hypertrophic mechanisms, and hyperplasia was particularly active in the juvenile phase.

Histochemical study of muscle fiber types in Synbranchus marmoratus bloch, 1795.

The myotomal muscle of Synbranchus marmoratus was investigated using histochemical and immunohistochemical reactions. This musculature is composed of a superficial red compartment, uniformly distributed around the trunk circumferentially and also in the lateral line. The red compartment fibers are small in diameter and have an oxidative metabolism, a high rate of glycogen and a negative reaction to alkaline and acid myofibrillar ATPase (mATPase). The white muscle forms the bulk of the muscle mass. Its fibers are large in diameter and have a glycolytic metabolism, a negative reaction to glycogen, a strong reaction to alkaline mATPase and a negative reaction to acid mATPase. Between these two compartments there is an intermediate layer of fibers presenting a mosaic metabolism pattern with a high rate of glycogen. These fibers stained moderately for alkaline and acid m-ATPase. Several clusters of red muscles were observed inside the white muscle. Each cluster is composed of three fiber types, with a predominance of red and intermediate fibers. Reactivity to anti-MHC BA-D5 was positive only in the intermediate fibers. Reactivity to anti-MHC SC-71 was negative in all fiber types.

Doenças do neurônio motor dos eqüinos: relato dos primeiros casos na América do Sul / Equine motor neuron disease: report on the first cases in South America

Foram realizados estudos dos casos de 6 eqüinos de raças e idades diferentes, apresentando um quadro clínico caracterizado principalmente por emagrecimento progressivo, atrofia e fraqueza muscular generalizada, fasciculaçöes e tremores musculares, alternância constante de apoio dos membros posteriores, deslocamento do apoio dos membros anteriores caudalmente e dos membros posteriores cranialmente, decúbito lateral prolongado e morte. A confirmaçäo do diagnóstico ocorreu mediante exames histopatológicos da medula espinhal, observando-se uma degeneraçäo e perda dos neurônios localizados no corno ventral do H medular, sendo a lesäo mais grave na regiäo das intumescências cervical e lombar. As biópsias musculares revelaram alteraçöes neuromusculares caracterizadas por atrofia neurogênica, complementando o diagnóstico de doença do neurônio motor. A atrofia e fraqueza muscular progressiva, assim como a degeneraçäo dos neurônios motores, säo similares àquelas descritas em humanos com esclerose lateral amiotrófica esporádica ou doença de Lou Gehrig's

[Experimental study of progressive facial hemiatrophy: effects of cervical sympathectomy in animals]. / Etude expérimentale de l'hémiatrophie faciale progressive: effets de la sympathectomie cervicale chez l'animal.

Progressive facial hemiatrophy (Romberg's syndrome) is of unknown cause and uncertain pathogenesis. The main pathogenetic hypotheses are: sympathetic system alterations, localized scleroderma, trigeminal changes, possibly of genetic origin. To test the hypothesis of sympathetic system alterations, we designed an experimental model with ablation of the superior cervical sympathetic ganglion in rabbits, cats and dogs. All the animals were operated upon when 30 days old and were examined monthly for 1 year. During this period localized alopecia, corneal ulceration, keratitis, strabismus, enophthalmos, ocular atrophy, hemifacial atrophy and slight bone atrophy on the side of the sympathectomy were observed. Thus, cervical sympathectomy reproduces in animals the principal clinical alterations of Romberg's syndrome. Our data suggest that the sympathetic system is involved in the pathogenesis of this syndrome.