Fuerza prensil y composición corporal en escolares colombianos. Estudio piloto

Introducción: Algunos estudios han encontrado relación entre exceso de peso y baja fuerza de prensión relativa. En países de ingresos socioeconómicos medianos y bajos hay pocas evidencias que evalúen la fuerza prensil y su relación con la composición corporal en población pediátrica. Objetivo: Evaluar la correlación entre la fuerza prensil y la composición corporal de escolares de Bucaramanga, Colombia. Materiales y métodos: Se realizó un estudio piloto de corte transversal, analítico, correlacional. Participaron niños en edad escolar de Bucaramanga, Colombia. Las principales variables dependientes fueron masa muscular, agua corporal total, proteínas (kg) y el porcentaje de grasa corporal. La variable independiente correspondió a la fuerza prensil. Se usó el coeficiente de correlación de Spearman para explorar la relación entre variables. Resultados: El promedio de la fuerza prensil en el total de la muestra fue de 13,8 ± 3,2 Newton. Se encontraron correlaciones positivas y estadísticamente significativas entre la fuerza prensil y la masa musculoesquelética (r = 0,73), agua corporal total (r = 0,73) y proteínas (r = 0,74). Discusión: Nuestros resultados son consistentes con evidencias previas que identifican a la fuerza prensil como un indicador de la composición corporal, específicamente en las variables de masa musculoesquelética y proteínas. Conclusión: Los niños en el tercil más alto de fuerza prensil presentan los terciles más altos de masa musculoesquelética, agua corporal total y proteínas.

Introduction: Some studies have found a relationship between excess weight and low relative grip strength. In countries with medium and low socioeconomic income, there is little evidence evaluating grip strength and its relationship with body composition in the pediatric population. Objective: To evaluate the correlation between grip strength and body composition of schoolchildren from Bucaramanga, Colombia. Materials and Methods: A cross-sectional, analytical, correlational pilot study was conducted. Schoolchildren from Bucaramanga, Colombia participated. The main dependent variables were muscle mass, total body water, protein (kg), and percentage of body fat. The independent variable corresponded to the prehensile force. Spearman's Correlation Coefficient was used to explore the relationship between variables. Results: The average prehensile force in the total sample was 13.8±3.2 Newton. Positive and statistically significant correlations were found between grip strength and musculoskeletal mass (r=0.73), total body water (r=0.73), and protein (r=0.74). Discussion: Our results are consistent with previous evidence that identifies grip strength as an indicator of body composition, specifically in the variables of musculoskeletal mass and protein. Conclusion: Children in the highest tertile of prehensile strength present the highest tertiles of skeletal muscle mass, total body water, and protein.

Effects of high-intensity gymnastics on skeletal muscle proteins / Efeitos da ginástica de alta intensidade sobre as proteínas musculares esqueléticas / Efectos de la gimnasia de alta intensidad en las proteínas musculares esqueléticas

ABSTRACT Introduction: Although the current method of muscle stretching in gymnastics teaching in colleges and universities can reduce sports fatigue, it has been shown to have little effect on the well-being of athletes because it requires a long recovery time from psychological fatigue. Progressive muscle relaxation training is a method that uses the basic principle of sympathetic nerve activity to reduce the impact of negative emotions psychologically and relieve fatigue physiologically, requiring a further study of its impact on muscle protein. Objective: Explore the effect of high-intensity gymnastics on skeletal muscle protein and study the progressive muscle relaxation training method post-workout adjustment. Methods: After three weeks of training, excluding the standard deviations in the experimental data caused by the athletes' irregular movements, the athletes' blood lactate content and heart rate were counted and recorded. The collected data were analyzed using Excel software to integrate and compare the data using the T-test method. Results: After exercise training, the skeletal muscle function indices of the subjects increased to different degrees. From the point of view of heart rate recovery efficiency, the rate of heart rate decline of progressive relaxation training was higher than that of the two groups, and the degree of fluctuation was lower than that of the two groups, indicating that the level of recovery in heart rate of progressive relaxation training was better. Conclusion: The action of the high-intensity gymnastics team has a good effect on improving the athletes' skeletal muscle and skeletal muscle proteins. Post-exercise conditioning training plays an important role in athletes' physical recovery. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: Embora o método de alongamento muscular atual no ensino de ginástica em faculdades e universidades consiga reduzir a fadiga esportiva, tem se mostrado pouco eficaz no bem-estar dos atletas por exigir grande tempo de recuperação da fadiga psicológica. O treinamento progressivo de relaxamento muscular é um método que usa o princípio básico da atividade nervosa simpática para reduzir o impacto das emoções negativas psicologicamente e aliviar a fadiga fisiologicamente, necessitando de mais estudos do seu impacto sobre a proteína muscular. Objetivo: Explorar o efeito da ginástica de alta intensidade sobre as proteínas musculares esqueléticas e estudar o método de treinamento progressivo de relaxamento muscular no ajuste pós-treino. Métodos: Após 3 semanas de treinamento, excluídos os desvios-padrão nos dados experimentais causados pelos movimentos irregulares dos atletas, foram contabilizados e registrados os conteúdos de lactato sanguíneo e frequência cardíaca dos atletas. Analisou-se os dados coletados, com o software Excel, para integrar e comparar os dados pelo método de teste-T. Resultados: Após o treinamento do exercício, os índices de função muscular esquelética dos sujeitos aumentaram em diferentes graus. Do ponto de vista da eficiência da recuperação da frequência cardíaca, a taxa de declínio da frequência cardíaca do treinamento de relaxamento progressivo foi maior do que a dos dois grupos, o grau de flutuação foi menor do que o dos dois grupos, indicando que o nível de recuperação na frequência cardíaca do treinamento de relaxamento progressivo foi melhor. Conclusão: A ação da equipe de ginástica de alta intensidade tem um bom efeito na melhoria do músculo esquelético e das proteínas musculares esqueléticas dos atletas. O treinamento de condicionamento pós-exercício desempenha um papel importante na recuperação física dos atletas. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: Aunque el método actual de elongación muscular en la enseñanza de la gimnasia en colegios y universidades consigue reducir la fatiga deportiva, se ha demostrado que tiene poco efecto en el bienestar de los atletas porque requiere un largo tiempo de recuperación de la fatiga psicológica. El entrenamiento de la relajación muscular progresiva es un método que utiliza el principio básico de la actividad nerviosa simpática para reducir el impacto de las emociones negativas desde el punto de vista psicológico y aliviar la fatiga desde el punto de vista fisiológico, lo que requiere un estudio más profundo de su impacto en la proteína muscular. Objetivo: Explorar el efecto de la gimnasia de alta intensidad sobre la proteína del músculo esquelético y estudiar el método de entrenamiento de relajación muscular progresiva en el ajuste posterior al entrenamiento. Métodos: Después de 3 semanas de entrenamiento, excluyendo las desviaciones estándar en los datos experimentales causadas por los movimientos irregulares de los atletas, se contó y registró el contenido de lactato en sangre y la frecuencia cardíaca de los atletas. Los datos recogidos se analizaron, con el programa informático Excel, para integrar y comparar los datos mediante el método de la prueba T. Resultados: Tras el entrenamiento con ejercicios, los índices de función del músculo esquelético de los sujetos aumentaron en diferentes grados. Desde el punto de vista de la eficacia de la recuperación de la frecuencia cardíaca, el índice de disminución de la frecuencia cardíaca del entrenamiento de relajación progresiva fue mayor que el de los dos grupos, el grado de fluctuación fue menor que el de los dos grupos, lo que indica que el nivel de recuperación de la frecuencia cardíaca del entrenamiento de relajación progresiva fue mejor. Conclusión: La acción del equipo de gimnasia de alta intensidad tiene un buen efecto en la mejora del músculo esquelético y de las proteínas del músculo esquelético de los atletas. El entrenamiento de acondicionamiento posterior al ejercicio desempeña un papel importante en la recuperación física de los deportistas. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Prenatal diagnosis and genetic etiology analysis of a fetus with nemaline myopathy / 中华围产医学杂志

We reported a fetus with limb abnormalities and abnormal ultrasound soft markers diagnosed with nemaline myopathy. A pregnant woman (G1P0) underwent amniocentesis at 18 +2 gestational weeks due to thickened nuchal translucency suggested by ultrasound at 13 +5 gestational weeks. Karyotyping and single nucleotide polymorphism array of the amniotic fluid cells showed no fetal abnormalities. However, ultrasonographic reexaminations at 23, 28, and 28 +1 weeks indicated limb abnormalities and thickened nuchal fold, and the pregnant woman chose to terminate the pregnancy at 29 +2 gestational weeks. Whole exome sequencing showed compound heterozygous mutations of c.602G>A (p.W201*) and c.1516A>C (p.T506P) in the KLHL40 gene inherited from the mother and the father, respectively, resulting in nemaline myopathy type 8.

Adaptações morfológicas musculares na espasticidadE: revisão da literatura / Muscular morphological adaptations of spasticity: literature review

Objetivos: O propósito deste artigo foi revisar as principais evidências dos efeitos da espasticidade sobre o tecido muscular.Fonte de dados: Foram consultados 35 artigos selecionados nas bases de dados PubMed e SciELO, a partir do ano de 1969. Os descritores utilizados no processo de busca foram spasticity, spastic, muscle architecture, muscle length, fascicle length, muscle histopathology, morphological changes, fiber type, sarcomere length, titin, stroke e cerebral palsy. A partir da análise dos títulos e resumos, foram selecionados 19 artigos que faziam menção a alterações estruturais musculares decorrentes de um quadro clínico positivo de espasticidade. As demais referências foram utilizadas para contextualizar e definir conceitos gerais necessários à introdução do tema.Síntese dos dados: Ocorrem diferentes tipos de adaptação da estrutura muscular em indivíduos com espasticidade quando comparados a indivíduos saudáveis. Essas alterações podem ocorrer tanto em nível macroscópico quanto microscópico. A espasticidade pode promover redução no comprimento e volume do ventre muscular, aumento do número de fibras do tipo I, redução de sarcômeros em série e aumento de tecido conjuntivo extracelular nos músculos espásticos.Conclusões: A espasticidade afeta o sistema muscular esquelético e impossibilita o desenvolvimento de funções motoras normais.

Aims: The purpose of this article was to review the main evidence of the effects of spasticity on muscle tissue.Source of data: We selected 35 articles in the databases PubMed and SciELO, from the year 1969. The key words used in the search process were spasticity, spastic, muscle architecture, muscle length, fascicle length, muscle histopathology, morphological changes, fiber type, sarcomere length, titin, stroke and cerebral palsy. From the analysis of titles and abstracts, 19 articles were selected, which made mention of muscle structural changes arising from a positive clinical spasticity. The other references were used to contextualize and to define general concepts necessary for introducing the topic.Summary of findings: Different types of adaptation of muscle structure occur in subjects with spasticity when compared to healthy subjects. These changes may occur at the macroscopic and at the microscopic level. Spasticity may reduce the length and volume of the muscle, increasing the number of type I fibers, reducing sarcomere number and increase extracellular tissue in spastic muscles.Conclusions: Spasticity affects the increasing system and prevents the development of normal motor functions.

An analysis of clinical features and pathology in 40 patients with dysferlinopathy / 中华神经科杂志

Objective To analyze retrospectively the clinical manifestations,features of the biopsy of skeletal muscle with histochemistry and immunohistochemistry staining of 40 patients with dysferlinopathy and investigate its clinical,pathological diagnostic value.Methods The clinical data,features of the biopsy of skeletal muscle with histochemistry,immunohistochemistry staining of 40 patients with dysferlinopathy were analyzed.Results Chronic progressive weakness and wasting were the general clinical manifestations.In our study,it was divided into three phenotypes according to the involved muscles of dysferlinopathy:27 cases with proximal muscle,12 cases with the gastrocenemius,1 case with the tibialis anterior muscle.The serum creatine kinase levels all had a rise in different degree (134-19 795 U/L).All the patients showed myogenic lesions in electrophysiologic study.12 patients underwent skeletal muscle MRI.Proximal muscle was involved in 4 cases ; gastrocnemius muscle was mainly involved in 7 cases ; and anterior tibial muscle initially was involved in 1 case.All 40 cases showed active muscle fiber degeneration,necrosis and regeneration on muscle pathology.Connective tissues were proliferated and inflammatory cells infiltrated in endomysium,perimysium and perivascular sites of 16 patients.Immunohistochemical staining with anti-dysferlin monoclonal antibody identified the deficiency of dvsferlin in the sarcolemma of 30 cases with dysferlinopathy,and dysferlin was severely reduced in 10 cases.Conclusion Progressive weakness and wasting of skeletal muscle are the clinical manifestations of dysferlinopathy.The early involved muscles determine the clinical phenotype of dysferlinopathy.High serum creatine kinase levels show that dysferlinopathy is a membrane protein null disease.Muscle MRI of lower limbs may reflect the involved muscles,which is essential for clinical phenotypes and selecting muscle biopsy.The pathological characters of dysferlinopathy are changes of muscular dystrophy.Inflammatory cellular infiltration is relatively common in biopsied muscles of many dysferlinopathy patients,and dysferlinopathy needs to be differentiated from inflammatory myopathies.The deficiency or severely decreased dysferlin on the sarcolemma in immunohistochemical staining with anti-dysferlin monoclonal antibody is an important information for diagnosing dysferlinoapthy.

Effects of Nitric Oxide Synthase Inhibitor on Hindlimb Muscles in Rats with Neuropathic Pain Induced by Unilateral Peripheral Nerve Injury

PURPOSE: The purpose of this study was to examine effects of nitric oxide synthase (NOS) inhibitor on muscle weight and myofibrillar protein content of affected and unaffected hindlimb muscles in rats with neuropathic pain induced by unilateral peripheral nerve injury. METHODS: Neuropathic pain was induced by ligation and cutting of the left L5 spinal nerve. Adult male Sprague-Dawley rats were randomly assigned to one of two groups: The NOSI group (n=19) had NOS inhibitor (L-NAME) injections daily for 14 days, and the Vehicle group (n=20) had vehicle injections daily for 14 days. Withdrawal threshold, body weight, food intake and activity were measured every day. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected from hindlimbs. Muscle weight and myofibrillar protein content of the dissected muscles were determined. RESULTS: The NOSI group showed significant increases as compared to the Vehicle group for body weight at 15 days, muscle weight and myofibrillar protein content of the unaffected soleus and gastrocnemius. The NOSI group demonstrated a higher pain threshold than the vehicle group. CONCLUSION: NOSI for 14 days attenuates unaffected soleus and gastrocnemius muscle atrophy in neuropathic pain model.

Identificação de isoformas miosínicas estruturais de músculo gastrocnêmio de ratos treinados e sedentários em gel bidimensional / Identification of isoforms of myosin structural gastrocnemius muscle of trained rats and sedentary two-dimensional gel

A biologia molecular e a fisiologia humana fornecem ferramentas pelas quais a atividade física pode ser avaliada em termos de atuação e interação no organismo, induzindo adaptações estruturais e funcionais. Desta forma, as proteínas musculares podem ser usadas como eventuais marcadores moleculares. Neste trabalho caracterizou-se a expressão de isoformas miosínicas, através da obtenção de um mapa eletroforético bidimensional, em músculo esquelético de ratos, em decorrência da realização de exercícios em esteira adaptada. Ratos Wistar machos foram divididos aleatoriamente em dois grupos: sedentário e exercício, mantidos em condições ideais. O grupo exercício foi submetido a sessões de treinamento, em dias alternados, 30 minutos por dia, durante 12 semanas, utilizando velocidades de 7 m/min a 20 m/min. O padrão eletroforético bidimensional com faixa de pI ácido, apresentou vários grupos protéicos como as miosinas, tropomiosinas, troponinas e a actina, identificados in silico. Dentro desses grupos, foi verificada a presença de algumas isoformas leves de miosina e uma isoforma lenta de troponina T. Os géis proteômicos mostram-se importantes na análise da composição muscular. As isoformas protéicas, especialmente as miosínicas, podem ser úteis na caracterização do exercício em termos de expressão de proteínas além de poder contribuir na avaliação do exercício físico.

Molecular biology and human physiology providing tools by which physical activity can be assessed in terms of action and interaction in the body, inducing structural and functional changes. Thus, muscle proteins can be used as potential molecular markers. This study characterized the expression of myosin isoforms, by a two-dimensional electrophoretic map, in skeletal muscle of rats, as a result of induced exercise in treadmill. Wistar male rats were divided randomly into two groups: sedentary and exercise, held in ideal conditions. The exercise group was subjected to sessions of training on alternate days, 30 minutes per day for 12 weeks, using speed of 7 m / min to 20 m / min. The electrophoretic two-dimensional standard on acid pI range, presented various protein groups such as myosin, tropomyosin, troponin and actin, identified in silico. Within these groups, there was the presence of some light isoforms of myosin and a slow isoform of troponin T. The proteomic gels become important in analysis of the skeletal muscle composition. The protein isoforms, especially myosin, may be useful in characterizing the exercise training in terms of expression of proteins and could help in evaluation of the exercise.

Clinical and pathological features of the 5 Limb-girdle muscular dystrophy 2A patients / 中华神经科杂志

Objective To investigate the clinical and molecular pathological features of limb-girdle muscular dystrophy 2A (LGMD2A) of Chinese patients. Methods Thirty cases of LGMD with excluding LGMD2B were included in this study. The muscle specimens were performed by a standard series methods of histochemistry, enzymohistochemistry, immunohistochemistry and Western blot. The clinical and molecular pathological features of LGMD2A were retrospective analyzed. Results Five cases with no or only trace expression of calpain-3 protein were diagnosed as calpainopathy (LGMD2A) by Western blot analysis. The age of onset of these 5 patients ranged from 10 to 45 years and the duration of the disease were about 2-10 years. Proximal muscles weakness and atrophy of lower limbs were predominantly involved. In all patients,symptoms progressed slowly. The ambulation could be retained for many years but running and jumping were impaired early. The serum creatine kinase level was elevated moderately to markedly. Electromyography showed myopathic patterns in all cases. Two siblings had similar symptoms indicating autosomai recessive inherited pattern. Pathologically, there was marked variation in fibre size and most small fibres were round. Some necrotic and regenerating fibers were seen. Fibres with centrally placed nuclei can be found frequently. No infiltrations of inflammatory cells were seen. Lobulated fibers were observed in 2 patients by NADH-TR stain. The expression of dystrophin, caveolin-3, α-, β-, γ- and δ-sarcoglycan protein were normally staining of 5 LGMD2A patients' specimens by immunohistochemistry. Two patients had reduced staining of dysferlin by immunohistochemistry study. Conclusions Clinical and pathological characteristics of our 5 LGMD2A patients are consistent with typical muscular dystrophy features reported in other countries. Identification of calpian-3 deletion by Western blot is essential for the diagnosis of calpainopathy.

Diagnosing limb-girdle muscular dystrophy type 2A by Western blot analysis / 中华神经科杂志

Objective To evaluate Western blot analysis in diagnosing limb-girdle muscular dystrophy type 2A (LGMD2A). Methods The clinical records including their pathological and biochemical results of 4 patients with LGMD type 2 were reviewed. Histochemical and immunohistochemical staining were performed on muscle biopsy specimens from the four patients. The expressions of dysferlin and calpain-3 in muscles were analyzed by Western biol. Results All 4 LGMD patients shared some common clinical features, such as dorsal muscular atrophy of lower limbs and remarkably elevated CK. The immunohistochemical results showed partial or complete deficiency of dysferlin staining in all 4 LGMD patients. However, Western blot revealed that the calpain-3 protein in the muscle of patient 1 was completely absent, who was later diagnosed with LGMD2A. The other 3 patients had complete dysferlin deficiency with reduced calpain-3 expression and they were confirmed to be LGMD2B. Conclusions Western blot analysis of calpain-3 and dysfcrlin can be used to differentiate LGMD2A which shows absence of calpain-3 from other LGMD types which show dysferlin deficiency. Western blot is an invaluable method in clinical diagnosis of LGMD2A.

Clinical significance of myasthenia gravis-related autoantibodies / 中华神经科杂志

Objective To investigate the clinical significance of myasthenia gravis (MG) associated autoantibodies.Methods Titin,ryanodine receptor (RyR)and acetylcholine receptor (AChR) antibodies were examined in the sera of 74 myasthenia gravies patients by ELISA.Results AChR,Titin, RyR antibodies were detected in 77.0% (57/74),39.2% (29/74) and 32.4% (24/74) of the MG patients,respectively.For thymoma MG,AChR,Titin and RyR antibodies were detected in 76.2% (16/21),71.4% (15/21) and 52.4% (11/21) respectively.For late onset MG,Titin and RyR antibodies were detected in 77.3% (17/22) and 50.0% (11/22) respectively.With respect to the modified Osserman classification,the positve rate for Titin and RyR antibodies is much higher in more severe patients (X~2= 16.094,P=0.001;X~2=11.226,P=0.011).Titin antibodies was significantly related with RyR antibodies (r=0.380,P=0.001).Conclusions Titin and RyR antibodies show high sensitivity for thymoma MG,and the combination of serological and radiological testing can increase both sensitivity and specificity in diagnosis of thymoma MG.The levels of the two antibodies may serve as important prognosis markers in MG.The induction of the immune response against Titin and RyR and the possible pathogenic effects of the two antibodies will be further studied.

Changes of expression of MLP mRNA and protein during the progression of left ventricular hypertrophy induced by chronic pressure overload in rats / 中国病理生理杂志

AIM: To study changes of expression of muscle LIM protein(MLP) mRNA and protein during the progression of left ventricular hypertrophy induced by coarctation of abdominal aorta in rats and to explore if there is disruption of cytoskeleton protein during hypertrophic growth in left ventricle. METHODS: Using a model of hypertrophy induced by coarctation of abdominal aorta(CAA) in male Wistar rats, hemodynamics, ventricular hypertrophic index, expression of MLP mRNA and protein were investigated in the experimental animals at 1, 4, 8, 16 weeks after operation and sham operation. RESULTS: Left ventricular shows significantly hypertrophy 4 weeks after operation ( P0.05 ). CONCLUSIONS: MLP changed at transcription level and there was no disruption of cytoskeleton during hypertrophic growth of left ventricle without sever heart failure. As the actin-base cytoskeleton protein, MLP plays a critical role in the maintenance of cardiac myocyte cytoskeleton and cardiac systolic function.

Effects of prolonged heavy load swimming and the Panaxadiol saponins on expression of ?-actin of quadriceps in rats / 中国病理生理杂志

AIM: To study the effects of 7 weeks prolonged haevy load swimming and Panaxadiol Saponins (PDS) on the expression of ?-actin in quadriceps muscle of thigh in rats. METHODS: After 7 weeks prolonged heavy load swimming training, the expression of ?-actin in quadriceps muscle of thigh was quantitatively examined by Northern blotting analysis in the condition with or without PDS treatment. RESULTS: The expression of ?-actin in rat quadriceps muscle of thigh in exercise+PDS group was significantly higher than that in sedentray control group and exercise+saline group at 24 th hour after intensive training. No statistical difference between exercise+androsan group and exercise+saline group was observed.CONCLUSION: PDS enhanced ?-actin expression in quadriceps muscle of thigh in rats.

Titin and Ryanodine receptor epitopes are expressed in thymoma with myasthenia gravis patients / 中华神经科杂志

Objective To study the significance of Titin-ab and Ryanodine receptor-ab (RyR-ab) in the myasthenia gravis (MG) patients and the expression of Titin and RyR epitopes in thymoma of myasthenia gravis.Methods Using ELISA methods,the titer of the Titin-ab,RyR-ab in the sera of 62 patients with MG,as well as 45 cases non-MG with other neurologic disorders and 50 case of normal controls were determined,and Titin and RyR were studied with immunohistochemistry stain in the 19 samples of thymic tissues from 9 cases of MG with thymoma (MGT),6 cases of MG with thymic hyperplasia (MGH), 2 cases of MG with thymic atrophy (MGA),and 2 cases of non-MG with thymic carcinoma (NMGTC). Results The positive rate of Titin-ab in MG was 35.5% (22/62),with the highest being 82.3% (14/17) in MGT group.The positive rate of RyR-ab was 24.2% (15/62),the highest being 76.5% (13/17) in MGT group.Titin receptor epitopes were expressed in the transmembrane and cytoplasm region of thymoma epithelial cells of 7 cases of MGT patients,and RyR epitopes in the transmembrane region of thymoma epithelial cells of 6 cases of MGT;but no Titin nor RyR epitopes was identified in controls and such thymic pathological patterns,as MGH,MGA,NMGTC.Conclusions Titin-ab and RyR-ab are mostly found in MGT patients;Titin and RyR epitopes are expressed in neoplasm epithelial cells of thymoma with myasthenia gravis;it's a result of autoimmunization of Titin and RyR epitopes irritated by Titin and RyR specific T cells activated by the change of pathogenic microenvionment inside the thymoma.

Effects of Food Protein Quality on Protein Metabolism of Skeletal Muscle in Young Rats / 第三军医大学学报

The experimental rats were fed with 5 test diets of different protein quality.RNA content and 3-methylhistidhie(3-MH) in urine were determined.The results showed that the RNA content of the skeletl muscle cells was significantly different in rais fed with different diet.A linear correlation between RNA content and amino acid score of food protein was perceived.Food with the higher protein quality,the more 3-MH in urine was excreted.A good correlation between excrstiou of 3-MH and Net Portein Utilization(NPU),an index reflecting protein quality,existed too.These suggested that protein quality regulates the balance between auabolism and catabolism,meaning the turnover of skeletal muscle proteinThe mechanism of strengthening anabolism,not reducing catabolism,can explain that high protein quality could improve growth of animals.