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Testosterone represses ubiquitin ligases atrogin-1 and Murf-1 expression in an androgen-sensitive rat skeletal muscle in vivo

PIRES-OLIVEIRA, Marcelo; MARAGNO, Ana Leticia G. C.; PARREIRAS-E-SILVA, Lucas T.; CHIAVEGATTI, Tiago; GOMES, Marcelo D.; GODINHO, Rosely O.
Fonte: AMER PHYSIOLOGICAL SOC Publicador: AMER PHYSIOLOGICAL SOC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Pires-Oliveira M, Maragno AL, Parreiras-E-Silva LT, Chiavegatti T, Gomes MD, Godinho RO. Testosterone represses ubiquitin ligases atrogin-1 and Murf-1 expression in an androgen-sensitive rat skeletal muscle in vivo. J Appl Physiol 108: 266-273, 2010. First published November 19, 2009; doi:10.1152/japplphysiol.00490.2009.-Skeletal muscle atrophy induced by denervation and metabolic diseases has been associated with increased ubiquitin ligase expression. In the present study, we evaluate the influence of androgens on muscle ubiquitin ligases atrogin-1/MAFbx/FBXO32 and Murf-1/Trim63 expression and its correlation with maintenance of muscle mass by using the testosterone-dependent fast-twitch levator ani muscle (LA) from normal or castrated adult male Wistar rats. Gene expression was determined by qRT-PCR and/or immunoblotting. Castration induced progressive loss of LA mass (30% of control, 90 days) and an exponential decrease of LA cytoplasm-to-nucleus ratio (nuclear domain; 22% of control after 60 days). Testosterone deprivation induced a 31-fold increase in LA atrogin-1 mRNA and an 18-fold increase in Murf-1 mRNA detected after 2 and 7 days of castration, respectively. Acute (24 h) testosterone administration fully repressed atrogin-1 and Murf-1 mRNA expression to control levels. Atrogin-1 protein was also increased by castration up to 170% after 30 days. Testosterone administration for 7 days restored atrogin-1 protein to control levels. In addition to the well known stimulus of protein synthesis...

Contribuição do complexo enzimático NADPH oxidase na atrofia muscular de ratos infartados: influência do treinamento físico aeróbico; Contribution of NADPH oxidase enzyme complex in muscle atrophy of infarcted rats: role of aerobic exercise training

Bechara, Luiz Roberto Grassmann
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 04/12/2012 PT
Relevância na Pesquisa
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Em quadros mais avançados da insuficiência cardíaca (IC), além do comprometimento do miocárdio, observa-se uma importante perda de massa muscular esquelética, a qual contribui para o mau prognóstico e orbimortalidade dos pacientes. As espécies reativas de oxigênio (ROS) parecem estar diretamente envolvidas no desenvolvimento e progressão da atrofia muscular em doenças crônico-degenerativas. De fato, já é sabido que a IC está associada ao estresse oxidativo na musculatura esquelética, o qual parece contribuir para o catabolismo proteico culminando em atrofia muscular na síndrome, apesar desta relação de causa e efeito ainda ser pouco investigada. No entanto, as fontes envolvidas na produção exacerbada de ROS na musculatura esquelética em ratos com infarto do miocárdio ainda não foram caracterizadas. Como a NADPH oxidase é um complexo enzimático especializado em produzir ROS, e sabendo que esta família de enzimas pró-oxidantes é ativada for agentes pró-inflamatórios e alguns agonistas de receptores acoplados à proteína G que estão aumentados na IC, na primeira parte do projeto de pesquisa testou-se a hipótese de que as NADPH oxidases estariam hiperativadas nos músculos plantar e sóleo de ratos submetidos ao infarto do miocárdio...

Envolvimento da neuraminidase-1 na regeneração muscular; The role of neuraminidase-1 in muscle regeneration

Neves, Juliana de Carvalho
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/03/2014 PT
Relevância na Pesquisa
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A neuraminidase-1 (Neu1) participa da regulação do catabolismo de sialoglicoconjugados nos lisossomos. A deficiência congênita da Neu1 é a base da sialidose, doença neurossomática grave associada a deformidades osteoesqueléticas, hipotonia e fraqueza muscular. Camundongos com deficiência de Neu1 (Neu1-/-) desenvolvem uma forma atípica de degeneração muscular caracterizada por expansão da matriz extracelular (MEC), invasão das fibras musculares por fibroblastos, fragmentação do citoplasma, formação vacuolar e atrofia muscular. Apesar de a degeneração muscular estar bem caracterizada nestes animais, a miogênese ainda não havia sido estudada. O objetivo desta pesquisa foi avaliar o envolvimento da Neu1 no processo de regeneração muscular, após aplicação de cardiotoxina (CTX) em camundongos Neu1-/-, em comparação com controles normais. A CTX foi administrada no músculo tibial anterior direito e os animais foram eutanasiados por deslocamento cervical 1, 3, 5, 7, 10, 14, 21 e 28 dias após a lesão. Os músculos foram analisados através de histologia; medição da área transversa das fibras musculares centronucleadas; verificação do potencial proliferativo celular por quantificação de marcação de BrdU; imunoistoquímica para inflamação...

Differential morphofunctional characteristics and gene expression in fast and slow muscle of rats with monocrotaline-induced heart failure

Bertaglia, Raquel Santilone; Reissler, Joyce; Lopes, Francis Silva; Garrido Cavalcante, Walter Luiz; Carani, Fernanda Regina; Padovani, Carlos Roberto; Rodrigues, Sergio Augusto; Cigogna, Antonio Carlos; Carvalho, Robson Francisco; Henrique Fernandes, Ana
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 205-215
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Processo FAPESP: 09/51060-8; Heart failure (HF) is characterized by limited exercise tolerance, skeletal muscle atrophy, a shift toward fast muscle fiber, and myogenic regulatory factor (MRF) changes. Reactive oxygen species (ROS) also contribute to target organ damage in this syndrome. In this study, we investigated and compared morphofunctional characteristics and gene expression in Soleus (SOL-oxidative and slow twitching muscle) and in Extensor Digitorum Longus (EDL-glycolytic and fast twitching muscle) during HF. Two groups of rats were used: control (CT) and heart failure (HF), induced by a single injection of monocrotaline. MyoD and myogenin gene expression were determined by RT-qPCR, and MHC isoforms by SDS-PAGE; muscle fiber type frequency and cross sectional area (CSA) were analyzed by mATPase. A biochemical study was performed to determine lipid hydroperoxide (LH), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD); myography was used to determine amplitude, rise time, fall time, and fatigue resistance in both muscles. HF showed SOL and EDL muscle atrophy in all muscle fiber types; fiber frequency decreased in type IIC and muscle contraction fall time increased only in SOL muscle. Myogenin mRNA expression was lower in SOL and myoD decreased in HF EDL muscle. LH increased...

Differential MMP-2 and MMP-9 Activity and Collagen Distribution in Skeletal Muscle from pacu (Piaractus mesopotamicus) During Juvenile and Adult Growth Phases

Michelin, Aline Cristina; Justulin, Luis Antonio; Delella, Flávia Karina; Padovani, Carlos Roberto; Felisbino, Sergio Luis; Dal-Pai-Silva, Maeli
Fonte: Wiley-liss Publicador: Wiley-liss
Tipo: Artigo de Revista Científica Formato: 387-395
ENG
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Here, we evaluated collagen distribution and matrix metalloproteinases (MMPs) MMP-2 and MMP-9 activities in skeletal muscle of pacu (Piaractus mesopotamicus) during juvenile and adult growth phases. Muscle samples from juvenile and adult fishes were processed by histochemistry for collagen system fibers and for gelatin-zymography for MMP-2 and MMP-9 activities analysis. Picrosirius staining revealed a myosept, endomysium, and perimysium-like structures in both growth phases and muscle types, with increased areas of collagen fibers in adults, mainly in red muscle. Reticulin staining showed that reticular fibers in the endomysium-like structure were thinner and discontinuous in the red muscle fibers. The zymography revealed clear bands of the pro-MMP-9, active-MMP-9, intermediate-MMP-2, and active-MMP-2 forms in red and white muscle in both growth phases. MMP-2 activity was more intense in juvenile than adult muscle fibers. Comparing the red and white muscle types, MMP-2 activity was significantly higher in red muscle in adult phase only. The activity of MMP-9 forms was similar in juvenile red and white muscles and in the adult red muscle, without any activity in adult white muscle. In conclusion, our results show that, in pacu, the higher activities of MMP-2 and -9 are associated with the rapid muscle growth in juvenile age and in adult fish...

Histoenzymological and ultrastructural changes in lateral muscle fibers of Oreochromis niloticus (Teleostei: Cichlidae) after local injection of veratrine

Silva Freitas, Erika Maria; Dal Pai Silva, Maeli; Da Cruz-Höfling, Maria Alice
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 525-534
ENG
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The effects of veratrine have been investigated in mammalian, amphibian, and crustacean muscle, but not in fish. In this work, the action of veratrine was studied in the lateral muscle of the freshwater teleost Oreochromis niloticus after intramuscular injection. Histoenzymological typing and electron microscopy of muscle fibers before and 15, 30, and 60 min after veratrine injection (10 ng/kg fish) were used to indirectly assess the morphological changes and the oxidative and m-ATPase activities. In some cases, muscles were pretreated with tetrodotoxin to determine whether the ultrastructural changes were the result of Na+ channel activation by veratrine. Veratrine altered the metabolism of fibers mainly after 30 min. Oxidative fibers showed decreased NADH-TR activity, whereas that of glycolytic and oxidative-glycolytic type fibers increased. There was no change in the m-ATPase activity of the three fiber types, except at 60 min postveratrine, when a novel fiber type, which showed no reversal after acidic and alkaline preincubations, appeared. Ultrastructural damage involved sarcomeres, myofibrils, and mitochondria, but the T-tubules remained intact. Pretreatment with tetrodotoxin (1 ng/ml) prevented the ultrastructural changes caused by veratrine. These results show that in fish skeletal muscle veratrine produces some effects that are not seen in mammalian muscle.

Short periods of fasting followed by refeeding change the expression of muscle growth-related genes in juvenile Nile tilapia (Oreochromis niloticus)

Nebo, Caroline; Portella, Maria Célia; Carani, Fernanda Regina; de Almeida, Fernanda Losi Alves; Padovani, Carlos Roberto; Carvalho, Robson Francisco; Dal-Pai-Silva, Maeli
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 268-274
ENG
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Muscle growth mechanisms are controlled by molecular pathways that can be affected by fasting and refeeding. In this study, we hypothesized that short period of fasting followed by refeeding would change the expression of muscle growth-related genes in juvenile Nile tilapia (Oreochromis niloticus). The aim of this study was to analyze the expression of MyoD, myogenin and myostatin and the muscle growth characteristics in the white muscle of juvenile Nile tilapia during short period of fasting followed by refeeding. Juvenile fish were divided into three groups: (FC) control, feeding continuously for 42. days, (F5) 5. days of fasting and 37. days of refeeding, and (F10) 10. days of fasting and 32. days of refeeding. At days 5 (D5), 10 (D10), 20 (D20) and 42 (D42), fish (n = 14 per group) were anesthetized and euthanized for morphological, morphometric and gene expression analyses. During the refeeding, fasted fish gained weight continuously and, at the end of the experiment (D42), F5 showed total compensatory mass gain. After 5 and 10. days of fasting, a significant increase in the muscle fiber frequency (class 20) occurred in F5 and F10 compared to FC that showed a high muscle fiber frequency in class 40. At D42, the muscle fiber frequency in class 20 was higher in F5. After 5. days of fasting...

The effect of muscle fatigue on the last stride before stepping down a curb

Barbieri, Fabio Augusto; Lee, Yun-Ju; Gobbi, Lilian Teresa Bucken; Pijnappels, Mirjam; Van Dieën, Jaap H.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 542-546
ENG
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The stride before landing may be important during stepping down. The aim of this study was to analyze variability of the kinematics and muscle activity in the final stride before stepping down a curb, with and without ankle and knee muscle fatigue. Ten young participants walked at self-selected speed and stepped down a height difference (10-cm) in ongoing gait. Five trials were performed before and after a muscle fatigue protocol (one day: ankle muscle fatigue, another day: knee muscle fatigue). The analysis focused on the trailing leg during the last but one and the last step on the higher level. Kinematics and muscle activity were recorded. Fatigue increased variability of foot-step horizontal distance in the last step on the higher level of the trailing limb, as well as in the first steps on the lower level for both limbs. This appeared due to an increase in the range of motion of the knee joint after both fatigue protocols. Participants additionally showed an increased ankle and hip ROM and decreased knee ROM. Our results suggest a loss of control under fatigue reflected in a higher variability of trailing and leading limb-step horizontal distances, with compensatory changes to limit fatigue effects, such as a redistribution of movement over joints. © 2012 Elsevier B.V.

Efeito da reabilitação protetica removivel bucal na espessura muscular e força de mordida em crianças na dentição mista; Effect of the removable prosthetic rehabilitation on muscle thickness and bite force of children in the mixed dentition

Marcia Diaz Serra
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 22/02/2006 PT
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O objetivo deste estudo foi avaliar a força de mordida e a espessura dos músculos mastigatórios em 25 crianças com perda precoce de dentes decíduos posteriores antes e após reabilitação bucal com prótese parcial removível. Para tanto, o estudo é composto de três capítulos. No capítulo 1, intitulado Maximum bite force ? a review of the literature, realizou-se a revisão de literatura sobre força de mordida e discorreu-se sobre as variáveis influenciadoras. A revisão mostrou que a força de mordida tem sido amplamente avaliada e associada às variáveis morfológicas e funcionais do sistema mastigatório. No capítulo 2 intitulado A six-month evaluation of maximum bite force in wearing a removable dental prosthesis avaliou-se a força de mordida das crianças, e no capítulo 3, intitulado Masseter and temporalis muscle thickness of children wearing removable dental prosthesis ? a six-month evaluation avaliou-se a espessura dos músculos masseter e porção anterior temporal através da ultra-sonografia. Avaliou-se também as variáveis corporais, representadas por proporções faciais, peso e altura nos capítulos 2 e 3. A força de mordida foi obtida utilizando-se um transmissor constituído de um tubo de fibra reforçada...

Expressão dos fatores de regulação miogenica e de cadeia pesada da miosina no musculo estriado esquelitico da tilapia do Nilo (Oreochromis niloticus) durante o crecimento; Miogenic regulatory factors and myosin heavy chain expression in the striated skeletal muscle of the Nile tilapia (Oreochromis niloticus) during growth

Danilo Henrique Aguiar
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/03/2008 PT
Relevância na Pesquisa
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Nos peixes, o conhecimento dos fatores que controlam o crescimento muscular e a análise das proteínas miofibrilares, é importante para entender a dinâmica do crescimento, a plasticidade e as adaptações musculares, principalmente, em espécies com grande valor comercial como a tilápia do Nilo (Oreochromis niloticus). No presente estudo, utilizou-se a tilápia do Nilo em quatro estágios: alevinos de 35 dias (0.65g ± 0.08); juvenis de 60 dias (13.67g ± 1.35); adultos de 90 dias (73.18g ± 4.70) e adultos de 190 dias (349.76g ± 34.62). Em cada estágio, fragmentos musculares foram coletados e submetidos às seguintes análises: morfométrica, para caracterizar o crescimento muscular hiperplásico e hipertrófico no músculo branco; imunohistoquímica, para analisar a expressão dos fatores de regulação miogênica MyoD e miogenina e a expressão da proteína PCNA no músculo branco; histoquímica da ATPase miofibrilar (mATPase) e à eletroforese em gel de poliacrilamida ? duodecil sulfato de sódio (SDS-PAGE) para observar as características da mATPase e da cadeia pesada da miosina nos músculos branco e vermelho, respectivamente. Os resultados indicaram que a expressão de MyoD e miogenina foi similar em alevinos, juvenis e adultos de 90 dias...

Time-course changes of muscle protein synthesis associated with obesity-induced lipotoxicity

Masgrau, Aurélie; Mishellany-Dutour, Anne; Murakami, Hitoshi; Beaufrère, Anne-Marie; Walrand, Stéphane; Giraudet, Christophe; Migné, Carole; Gerbaix, Maude; Metz, Lore; Courteix, Daniel; Guillet, Christelle; Boirie, Yves
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
EN
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The object of the study was to investigate the sequential changes of protein synthesis in skeletal muscle during establishment of obesity, considering muscle typology. Adult Wistar rats were fed a standard diet for 16 weeks (C; n = 14), or a high-fat, high-sucrose diet for 16 (HF16; n = 14) or 24 weeks (HF24; n = 15). Body composition was measured using a dual-energy X-ray absorptiometry scanner. The fractional synthesis rates (FSRs) of muscle protein fractions were calculated in tibialis anterior (TA) and soleus muscles by incorporation of l-13C-valine in muscle protein. Muscle lipid and mitochondria contents were determined using histochemical analysis. Obesity occurred in an initial phase, from 1 to 16 weeks, with an increase in weight (P < 0.05), fat mass (P < 0.001), muscle mass (P < 0.001) and FSR in TA (actin: 5.3 ± 0.2 vs. 8.8 ± 0.5% day−1, C vs. HF16, P < 0.001) compared with standard diet. The second phase, from 16 to 24 weeks, was associated with a weight stabilization, a decrease in muscle mass (P < 0.05) and a decrease in FSR in TA (mitochondrial: 5.6 ± 0.2 vs. 4.2 ± 0.4% day−1, HF16 vs. HF24, P < 0.01) compared with HF16 group. Muscle lipid content was increased in TA in the second phase of obesity development (P < 0.001). Muscle mass...

Stem Cell-Based Strategies to Enhance Muscle Regeneration through Extrinsic and Intrinsic Regulators

Tan, Kah Yong
Fonte: Harvard University Publicador: Harvard University
Tipo: Thesis or Dissertation
EN_US
Relevância na Pesquisa
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Skeletal muscle has a remarkable capacity for regeneration, mediated by muscle stem cells that can self-renew or differentiate to form the mature myofibers of the tissue. Several human diseases are characterized by a loss of function and strength in skeletal muscle, with impairments in the ability to regenerate and consequent decreases in quality of life and increases in mortality. The work in this dissertation has focused on developing methods for combating muscle disease. This goal has been approached through attempts at cell replacement therapy - by generating muscle cells that can be engrafted in vivo. I also investigated the influence on regeneration of the skeletal muscle microenvironment (skeletal muscle-resident fibroblasts), and systemic environment (inflammation in myogenic and non-myogenic tissues), both of which were found to affect skeletal muscle stem cell behavior and the efficiency of myogenic regeneration. Ultimately, these studies identified novel factors that impair or improve skeletal muscle differentiation, and that offer the potential to modulate the process of muscle regeneration. In the process of investigating if induced pluripotent stem cells from skeletal muscle retain an epigenetic memory conducive to myogenic differentiation...

Remodelage du muscle lisse péribronchique dans l’inflammation respiratoire chronique

Leclère, Mathilde
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
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Le souffle chez les chevaux et l’asthme chez l’humain sont des maladies respiratoires qui partagent plusieurs caractéristiques, notamment des épisodes de bronchospasme et de détresse respiratoire dus à une inflammation pulmonaire inappropriée en réponse à une inhalation de substances antigéniques. Les manifestations cliniques incluent des efforts respiratoires augmentés, des sifflements et de la toux. Au niveau des voies respiratoires, on observe une augmentation du muscle lisse péribronchique, une fibrose sous épithéliale, une métaplasie/hyperplasie épithéliale et du mucus en quantité augmentée. L’augmentation du muscle lisse est particulièrement importante car elle n’affecte pas seulement le calibre basal des voies respiratoires, mais elle accentue l’obstruction respiratoire lors de bronchoconstriction. Ces changements sont regroupés sous le terme de « remodelage » et sont associés à un déclin accéléré de la fonction respiratoire chez les patients asthmatiques. Alors que les traitements actuels contrôlent efficacement le bronchospasme et relativement bien l’inflammation, leurs effets sur le remodelage sont mal connus. Dans le cadre de thèse, la réversibilité du remodelage musculaire péribronchique a été investiguée chez des chevaux atteints du souffle dans deux études longitudinales. Ces études...

Aquaporin-1 expression in visceral smooth muscle cells of female rat reproductive tract

Gannon, B. J.; Warnes, Graham Malcolm; Carati, C. J.; Verco, Christopher J.
Fonte: Journal of Smooth Muscle Research Publicador: Journal of Smooth Muscle Research
Tipo: Artigo de Revista Científica
Publicado em //2000 EN
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The aquaporins (AQ-s) are a group of intrinsic membrane proteins which facilitate movement of water across cell membranes ; their recent identification in the kidney has led to the reappraisal of the mechanisms and pathways of water movement across epithelia. Aquaporin-1, (CHIP-28) is reported distributed in cardiac myocytes and vascular smooth muscle cells of large arteries. A related protein, AQ-4, has been identified in the sarcolemma of skeletal muscle fibres. We report aquaporin expression in the cell membrane of smooth muscle cells of the rat genital tract ; fluorescence immunohistochemistry of rat uterine (fallopian) tube and vagina demonstrated AQ-1 in visceral smooth muscle of these tissues. In the uterine tube, AQ-1 labelling is most pronounced in the innermost longitudinal and the inner cells of the circular muscle layer and is absent from the outer longitudinal muscle layer of the myosalpinx. The possibility of a specific role for AQ-1 in tubal transport by altering the tubal luminal diameter during the estrus cycle is suggested.

Use of motor cortex stimulation to measure simultaneously the changes in dynamic muscle properties and voluntary activation in human muscles

Todd, G.; Taylor, J.; Butler, J.; Martin, P.; Gorman, R.; Gandevia, S.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
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Force responses to transcranial magnetic stimulation of motor cortex (TMS) during exercise provide information about voluntary activation and contractile properties of the muscle. Here, TMS-generated twitches and muscle relaxation during the TMS-evoked silent period were measured in fresh, heated, and fatigued muscle. Subjects performed isometric contractions of elbow flexors in two studies. Torque and EMG were recorded from elbow flexor and extensor muscles. One study (n = 6) measured muscle contraction times and relaxation rates during brief maximal and submaximal contractions in fresh and fatigued muscle. Another study (n = 7) aimed to 1) assess the reproducibility of muscle contractile properties during brief voluntary contractions in fresh muscle, 2) validate the technique for contractile properties in passively heated muscle, and 3) apply the technique to study contractile properties during sustained maximal voluntary contractions. In both studies, muscle contractile properties during voluntary contractions were compared with the resting twitch evoked by motor nerve stimulation. Measurement of muscle contractile properties during voluntary contractions is reproducible in fresh muscle and reveals faster and slower muscle relaxation rates in heated and fatigued muscle...

Regenerationsverhalten humaner Skelettmuskulatur bei neurogenen und myopathischen Muskelerkrankungen; Regeneration of human skeletal muscle in neurogenic and myopathic muscle diseases

Conzelmann, Sandra
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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36.36%
Für die Regeneration menschlicher Skelettmuskulatur sind die Satellitenzellen verantwortlich. Sie stellen eine ruhende Population an Zellen dar, die sich während der Myogenese von den Myoblasten trennt und ihre charakteristische Position an den Muskelfasern zwischen Plasma- und Basalmembran einnimmt. Nach Aktivierung kehren sie in den Zellzyklus zurück und sind in der Lage neue Muskelfasern zu bilden. In den vergangenen Jahren wurden zahlreiche Studien durchgeführt, die sich mit Aktivierung und Funktion dieser Zellen vorwiegend bei Tieren beschäftigten. Die Muskeltranskriptionsfaktoren der MyoD-Familie, vor allem MyoD1 und Myogenin, spielen in der Determinierungs- und Differenzierungsphase der aktivierten Satellitenzellen eine wichtige Rolle. Bisher ist noch wenig über Satellitenzellen in humaner Muskulatur bekannt. Diese Studie beschäftigte sich damit, unter Einbeziehung der tierexperimentell gewonnenen Ergebnisse, den Ablauf und die Stärke der Regeneration bei verschiedenen Erkrankungen zu vergleichen. Muskelbiopsien von vier Patienten, die an einer Muskeldystrophie vom Typ Duchenne (DMD) erkrankt sind, fünf Patienten mit anderen Muskeldystrophien (andere Dystrophien), elf Patienten, die an einer neurogenen Muskelatrophie leiden und vier Patienten ohne Hinweise auf eine Muskelerkrankung wurden untersucht. Immunhistochemische Färbungen der angefertigten Kryostatschnitte wurden auf die Häufigkeit angefärbter Zellen bzw. Zellkerne pro Muskelfaser ausgewertet. Die Gesamtzahl an Satellitenzellen wurde mit einem Antikörper gegen das Neural cell adhesion molecule (N-CAM) markiert. Aktivierte Zellen lassen sich mit Antikörpern gegen die Proteine MyoD1 und Myogenin nachweisen. Um neu gebildete Fasern zu kennzeichnen wurde jeweils ein Schnitt mit Hämatoxylin-Eosin (HE) gefärbt. Diese Fasern färben sich dabei...

Elektrogoniometrische Messungen der Gelenkkinetik an Kindern mit juveniler idiopathischer Arthritis - Erstellung eines biomechanischen Modells, Vergleich verschiedener Methoden zur Bestimmung der Muskelkraft; Electrogoniometric measurement of the joint kinetic of children with juvenile idiopathic arthritis - development of a biomechanical model, comparison of different methods for the measurement of muscle strength

Hansmann, Sandra
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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Bei Kindern mit juveniler idiopathischer Arthritis (JIA) entstehen durch die chronische Arthritis Schädigungen der Gelenke und deren Funktion. Im Rahmen der Arthritis, sowie der damit verbundenen Schonung kann es zu einer Abnahme der Muskelkraft kommen. Im Verlauf kann die Knochendichte abnehmen und eine sekundäre Osteoporose auftreten. Eine Kontrolle der Gelenkfunktion ist für die Beurteilung des Krankheitsverlaufes und Therapieerfolges bei Kindern mit JIA wünschenswert und wichtig. Die Elektrogoniometrie stellt ein einfaches, kostengünstiges Verfahren zur Beurteilung des Bewegungsumfanges von Gelenken dar. Sie erlaubt die Berechnung der Gelenkgeschwindigkeit und der Beschleunigung sowie der Muskeldrehmomente. Diese lassen Rückschlüsse auf die Kraft und indirekt auf die Knochenfestigkeit zu. Die vorliegende Arbeit beschäftigt sich mit der Möglichkeit der elektrogoniometrischen Messung der Muskeldrehmomente zur Beurteilung der Gelenkfunktion bei Kindern mit JIA. Zuerst werden Verfahren zur Erhebung der Extremitätenmassen überprüft, welche notwendig zur Berechnung von kinetischen Parametern sind. Das normale Wachstum von Kindern beeinflußt die Körperproportionen und die äußere Form der Segmente. Zusätzlich erschweren krankheitsbedingte Wachstumsverzögerungen und Deformitäten bei Kindern mit JIA die Bestimmung der Massen...

Avaliação da massa e força muscular em pacientes no pré e pós-transplante cardíaco; Evaluation of muscle mass and strength in patients in the pre and post heart transplant

Fernandes, Lenise Castelo Branco Camurça
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 15/09/2015 PT
Relevância na Pesquisa
36.39%
INTRODUÇÃO: Existem poucos estudos demonstrando que anormalidades musculares esqueléticas em pacientes com insuficiência cardíaca crônica persistem meses após o transplante cardíaco. No presente estudo, objetivamos avaliar massa muscular, e força muscular periférica e respiratória em pacientes no pré-transplante cardíaco, e no seguimento precoce (6 meses) e tardio (1,5 e 3 anos) pós-transplante cardíaco. Objetivamos verificar ainda a correlação entre força muscular periférica e respiratória em pacientes no pré e pós-transplante cardíaco. Comparamos, por fim, os dados de pacientes do pré-transplante cardíaco com um grupo controle de indivíduos saudáveis sem doença cardíaca. MÉTODOS: Tratou-se de estudo prospectivo do tipo coorte. Foram selecionados todos os pacientes em lista de espera para transplante cardíaco do Hospital de Messejana, do período de agosto de 2011 a março de 2013. Avaliamos idade, gênero, causas da insuficiência cardíaca, hipertensão, diabetes, tempo de espera na lista, tempo de internamento pós-transplante, tempo de ventilação mecânica, medida da força muscular respiratória, da força muscular periférica, da espessura do adutor do polegar, média bilateral da área de secção transversal do músculo psoas maior...

Tissue Engineering of a Differentiated Skeletal Muscle Construct with Controllable Structure and Function

Bian, Weining
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2011
Relevância na Pesquisa
36.36%

Transplantation of a functional engineered skeletal muscle substitute is a promising therapeutic option to repair irreversible muscle damage, and, on the other hand, functional muscle tissue constructs can serve as in vitro 3D tissue models that complement the conventional 2D cell cultures and animal models to advance our limited understanding of intrinsic myogenesis and muscle regeneration process. However, the engineering of skeletal muscle constructs with comparable contractile function to the native muscle is hampered by the lack of 1) effective and reproducible methods to form relatively large muscle constructs composed of viable, dense, aligned and matured myofibers, and 2) beneficial microenvironmental cues as well as physiological stimulations that favor the growth, differentiation and maturation of myogenic cells. Thus, in this thesis, I have developed a mesoscopic hydrogel molding approach to fabricate relatively large engineered muscle tissue networks with controllable thickness, pore dimensions, overall myofiber alignment and regional myofiber orientation. I then investigated the effect of variation in pore length on the force generation and passive properties of engineered muscle networks and the potential to improve the contractile function of engineered muscle networks with the treatment of a soluble neurotrophic factor...

Post-stroke muscle atrophy and intramuscular fat content in hemiparetic subjects

Ramsay, John W.
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
Relevância na Pesquisa
36.36%
Buchanan, Thomas S.; Stroke is a leading cause of long term disability in adults, affecting approximately 795,000 adults a year in the United States alone. Following stroke, muscle weakness contralateral to the brain lesion, or hemiparesis, is the most common impairment. Post-stroke hemiparesis is a concern clinically because it restricts many daily living tasks including reaching and grasping, stair-climbing, and most importantly, walking. Among many factors involved in post-stroke hemiparesis is muscle atrophy ??? a loss of muscle tissue resulting from immobilization, disuse, inactivation, or a combination thereof. Since muscle force is a function of muscle size, the amount of atrophy a post-stroke muscle undergoes is important in adequately describing any changes to its force-generating capability as a result of stroke. Few studies have measured muscle atrophy in post-stroke individuals, and none have attempted to quantify muscle atrophy for individual paretic and non-paretic muscle. In this thesis, Magnetic Resonance Imaging (MRI) and digital reconstruction software were used to measure muscle volumes for individual muscles as well as specific muscle groups in the hemiparetic lower extremity. All muscle volumes were adjusted to exclude non-contractile tissue content...