Navegando por Palavras-chave "músculo esquelético"
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- ItemSomente MetadadadosAnálise histomorfométrica da fibra muscular esquelética de pacientes suscetíveis à hipertermia maligna(Universidade Federal de São Paulo (UNIFESP), 2015-02-28) Santos, Joilson Moura dos [UNIFESP]; Silva, Helga Cristina Almeida da Silva [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Introduction: Malignant Hyperthermia (MH) is a skeletal muscle disease characterized by hypermetabolism after administration of inhaled anesthetics and depolarizing muscle relaxants, which may progress to irreversible shock and death. Pathological examination of muscle fiber using histomorphometry can be an additional tool for the assessment of patients susceptible to MH, when analyzed in association with the different phenotypes that are part of the clinical presentation of susceptibility to MH. Objectives: Analyzing the histological aspect and histomorphometry of skeletal muscle fibers in patients susceptible to MH, and determining a potential correlation with clinical changes as atrophy or muscle hypertrophy. Casuistic and methods: 97 subjects, with a history suggestive of susceptibility to MH and tested for MH with muscle in vitro contracture test (IVCT) between 2004 and 2012 were analyzed for demographic characteristics, laboratory and clinical findings, histopathology with histochemistry and morphometry in their skeletal muscle biopsy. Results: The data analyzed were from patients in their forties with predominance of women (52), whites (72) and personal or family history of MH (73). Signs of motor unit syndrome were present in 17 patients and muscular hypertrophy in 24. The IVCT was positive for susceptibility to MH in 60% of the study sample. Those tested positive were mainly males and showed increased creatine kinase with three of them (5%) showing incidental cores. Among the six patients with family history of myopathy with cores, two had IVCT positive for susceptibility to MH. From the two patients with personal history of myopathy with cores, one had IVCT positive for susceptibility to MH. Qualitative histological analysis revealed that none of the changes found were significantly more frequent among those susceptible to MH, however, atrophic fibers were more frequent in individuals tested negative for MH susceptibility. Regarding quantitative analysis, although no significant difference was found between susceptible and non-susceptible individuals to MH concerning the percent of type I or II muscle fibers, the proportion of type I fibers were positively correlated with muscle hypertrophy determined in physical examination. The hypertrophy of muscle fibers was more frequent in women susceptible to MH than in those not susceptible. Furthermore, in the female group hypertrophy of muscle fibers correlated with the syndrome of motor unit (SMU), creatine kinase, coefficient of variability and centralization nuclear. In females, increased cross sectional area of both type-I and type-II muscle fibers correlated with increased CK. On the other hand, SMU and centralization nuclear correlated with increased cross sectional area of the fiber subtype II only, whereas the coefficient of variability correlated with increased cross sectional area of the fiber subtype I in females. Conclusions: Qualitative histological analysis did not identify any changes that were present more frequently in the group susceptible to MH, which did not allow for establishing a myopathy directly associated with MH. However, atrophic fibers were more frequent in individuals not susceptible to the HM, suggesting the existence of undiagnosed myopathies that could have led to atypical reactions during anesthesia. Concerning patients with a personal or family history of myopathy with cores, susceptibility to MH should necessarily be investigated using IVCT. Quantitative analysis of muscle fiber revealed relevant data for understanding the impact of MH, such as the correlation between clinical muscle hypertrophy and the proportion of type-I fibers in patients susceptible to MH, and the presence of hypertrophy of muscle fibers in women susceptible to MH, This increased cross-sectional area in women susceptible to MH correlated with serum CK levels, SMU, coefficient of variability and nuclear centralization.
- ItemAcesso aberto (Open Access)Efeito da desnutrição protéica pré e pós-natal sobre a morfologia, a diferenciação e o metabolismo do tecido muscular estriado esquelético em ratos(Sociedade Brasileira de Pediatria, 2008-06-01) Alves, Alessandra Pires [UNIFESP]; Dâmaso, Ana Raimunda [UNIFESP]; Dal Pai, Vitalino; Universidade Federal de São Paulo (UNIFESP); Universidade do Oeste Paulista Departamento de HistologiaOBJECTIVE: To study the contractile properties, metabolism and morphological characteristics of muscles submitted to prenatal and postnatal protein malnutrition. METHODS: Animals were distributed into two groups: Control, normoprotein diet (CG; n = 15; 5/5/5), and Malnourished, hypoprotein diet (MG; n = 15; 5/5/5), and examined on the 7th, 14th, and 28th days of the experiment. Total body mass, weight, and the contractile properties and morphology of the anterior tibial muscle were assessed. Several 8 µm-thick tissue samples were taken from 7, 14, and 28 day old rats and stained with HE or subjected to NADH-TR or m-ATPase (pH = 4.4) techniques. RESULTS: Body and muscle weight were lower in the malnourished group. On the 7th day of malnutrition, muscle samples exhibited fibers with smaller diameter, higher polymorphism and higher endomysial conjunctive tissue content. Histochemical methods were unable to precisely determine the types of fiber present. On the 14th day, there were smaller muscle fibers, more polymorphism, many of them with central nuclei and moderate endomysial conjunctive tissue content. With reference to contractile properties, the m-ATPase reaction identified both slow and fast fibers. The NADH-TR reaction revealed the following types of fiber: slow oxidative (SO), fast oxidative glycolytic (FOG) and fast glycolytic (FG). On the 28th day smaller, bunched muscle fibers varying shapes. All three types of fiber exhibited unclear recognition limits with respect to contraction and metabolism. CONCLUSION: Our experimental results suggest that, in addition to the reduction in numbers of fibers, malnutrition retards the differentiation of the morphological, metabolic, and contractile characteristics of skeletal muscle fibers in growing rats.
- ItemAcesso aberto (Open Access)Expression of a cell death marker (clusterin) in muscle target fibers(Academia Brasileira de Neurologia - ABNEURO, 1993-09-01) Oliveira, Acary Souza Bulle [UNIFESP]; Corbo, Massimo; Duigou, Greg; Gabbai, Alberto Alain [UNIFESP]; Hays, Arthur P.; Universidade Federal de São Paulo (UNIFESP); Columbia University College of Physicians and Surgeons Department of NeurosurgeryWe report, for the first time, the expression of immunoractivity to clusterin in skeletal muscle. Clusterin, a protein probably related to the process of programmed cell death (apoptosis), was specifically very highly expressed in target fibers. All target fibers found in 50 muscle biopsy samples from a variety of neuromuscular disorders expressed a high concentration of clusterin in the middle of the targets. Clusterin was not expressed in any targetoid fibers or cores. Acute denervation, where targets are mostly seen, may be the beginning of apoptosis. Hence our findings support the concept that targets are harbingers of acute denervation.
- ItemAcesso aberto (Open Access)Isquemia e reperfusão de músculo sóleo de ratos sob ação da pentoxifilina(Sociedade Brasileira de Angiologia e de Cirurgia Vascular (SBACV), 2007-03-01) Brasileiro, José Lacerda; Fagundes, Djalma José [UNIFESP]; Miiji, Luciana Odashiro Nakao; Oshima, Celina Tizuko Fujiyama [UNIFESP]; Teruya, Roberto; Marks, Guido; Inouye, Celso Massaschi; Santos, Maldonat Azambuja; SBACV; Universidade Federal de Mato Grosso do Sul Hospital Universitário; Universidade Federal de São Paulo (UNIFESP); UFMS; UFMS Departamento de Clínica Cirúrgica; UFMS Hospital Universitário Comissão de Residência MédicaBACKGROUND: Reperfusion of the skeletal muscle worsens existing lesions during ischemia, since the production of reactive oxygen species, associated with intense participation of neutrophils, increases the inflammatory reaction that induces tissue changes. OBJECTIVE: To evaluate the morphological and immunohistochemical changes of the skeletal (soleus) muscle of rats submitted to ischemia and reperfusion with pentoxifylline. METHODS: Sixty rats were submitted to ischemia of the pelvic limb for 6 hours induced by clamping the left common iliac artery. After ischemia, group A animals (n = 30) were observed for 4 hours and group B animals (n = 30) for 24 hours. Six animals constituted the sham group. Pentoxifylline was applied only in the reperfusion period A2 (n = 10) and B2 (n = 10), and in ischemia and reperfusion periods in A3 (n = 10) and B3 (n = 10). The soleus muscle was evaluated by histological (fiber disruption, leukocyte infiltrate, necrosis) and immunohistochemical (apoptosis through caspase-3 expression) analysis. The non-parametric tests Kruskal-Wallis and Mann-Whitney (p < 0.05) were applied. RESULTS: The changes were more intense in group B1, with fiber disruption mean scores of 2.16±0.14; neutrophilic infiltrate of 2.05±0.10; and caspase-3 expression in the perivascular area of 4.30±0.79; and less intense in group A3, with means of 0.76±0.16; 0.92±0.10; 0.67±0,15, respectively (p < 0.05). Caspase-3 was more expressive in group B1 in the perivascular area, with mean of 4.30±0.79 when compared with group B1 in the perinuclear area, with mean of 0.91±0.32 (p < 0.05) CONCLUSIONS: The lesions were more intense when observation time was longer after reperfusion, and pentoxifylline attenuated these lesions, above all when used in the beginning of ischemia and reperfusion phases.
- ItemAcesso aberto (Open Access)Novos mecanismos pelos quais o exercício físico melhora a resistência à insulina no músculo esquelético(Sociedade Brasileira de Endocrinologia e Metabologia, 2009-06-01) Pauli, José Rodrigo [UNIFESP]; Cintra, Dennys Esper; Souza, Claudio Teodoro De; Ropelle, Eduardo Rochette; Universidade Federal de São Paulo (UNIFESP); Universidade Estadual de Campinas (UNICAMP); Universidade do Extremo Sul Catarinense Laboratório de Fisiologia e Bioquímica do ExercícioInsulin resistance of skeletal muscle glucose transport is a key-defect for the development of impaired glucose tolerance and type 2 diabetes. However, it is known that both an acute bout of exercise and chronic endurance exercise training can bring beneficial effects on insulin action in insulin-resistant states. However, little is currently known about the molecular effects of acute exercise on muscle insulin signaling in the post-exercise state in insulin-resistant organisms. This review provides new insight into the mechanism through which acute exercise restores insulin sensitivity, highlighting an important role for inflammatory proteins and S-nitrosation in the regulation of insulin signaling proteins in skeletal muscle.
- ItemAcesso aberto (Open Access)Paralisia periódica: estudo anátomo-patológico do músculo esquelético de 14 pacientes(Academia Brasileira de Neurologia - ABNEURO, 1994-03-01) Tengan, Célia Harumi [UNIFESP]; Oliveira, Acary Souza Bulle [UNIFESP]; Morita, Maria Da Penha Ananias [UNIFESP]; Kiyomoto, Beatriz Hitomi [UNIFESP]; Schmidt, Beny [UNIFESP]; Gabbai, Alberto Alain [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Periodic paralysis is a rare disease, characterized by transient weakness associated with abnormal levels of serum potassium. Muscle biopsy may show a wide range of abnormalities, vacuoles being more specifically linked to the disease. We analysed 17 muscle biopsies from 14 patients with periodic paralysis (14 hypokalemic, 2 hyperkalemic). All of them showed at least one histological abnormality. Fourteen specimens showed vacuoles that were peripheral, single, frequent and preferentially found in type I fibers. Frequency or severity of attacks did not correlate with the presence of vacuoles but those were more easily found in patients with long term disease. Ten biopsies showed tubular aggregates, specially on the patients with frequent crises or long term disease. A second biopsy was done in three patients and in two we observed a worsening of the histopathologic picture. One patient manifested interictal weakness with evident myopathic changes on the muscle biopsy. Nonspecific changes were found in variable degrees in 15 biopsies. Our study shows that vacuoles and tubular aggregates are frequent changes in periodic paralysis and therefore helpful for the diagnosis. Important myopathic findings in the muscle biopsy suggest a permanent myopathy which probably develops after severe crises or long term disease.