Search results for "skeletal muscle"

Régulation des défenses antioxydantes dans la prévention du déconditionnement musculaire

2019

Musculoskeletal system plays a key role in organism’s well functioning and is responsible for a large variety of functions such as posture, locomotion, balance, and activities of daily life. The quality of the skeletal muscle is therefore capital to maintain quality of life and, in the long term, survival. Hypoactivity and aging are two situations that cause skeletal muscle deconditioning, therefore sharing common characteristics: loss of muscle strength, muscular atrophy and MyHC redistribution, as well as IMAT accumulation. To date, there is plenty of evidence supporting a causative link between oxidative stress phenomenon and muscle deconditioning. The two studies exposed in this thesis …

Differential influence of peripheral and systemic sex steroids on skeletal muscle quality in pre- and postmenopausal women

2011

Aging is associated with gradual decline of skeletal muscle strength and mass often leading to diminished muscle quality. This phenomenon is known as sarcopenia and affects about 30% of the over 60-year-old population. Androgens act as anabolic agents regulating muscle mass and improving muscle performance. The role of female sex steroids as well as the ability of skeletal muscle tissue to locally produce sex steroids has been less extensively studied. We show that despite the extensive systemic deficit of sex steroid hormones in postmenopausal compared to premenopausal women, the hormone content of skeletal muscle does not follow the same trend. In contrast to the systemic levels, muscle t…

Global gene expression profiles in skeletal muscle of monozygotic female twins discordant for hormone replacement therapy

2010

Summary Aging is accompanied by inexorable loss of muscle tissue. One of the underlying causes for this is the massive change in the hormonal milieu of the body. The role of a female sex steroid – estrogen – in these processes is frequently neglected, although the rapid decline in its production coincides with a steep deterioration in muscle performance. We recruited 54- to 62-year-old monozygotic female twin pairs discordant for postmenopausal hormone replacement therapy (HRT, n = 11 pairs; HRT use 7.3 ± 3.7 years) from the Finnish Twin Cohort to investigate the association of long-term, estrogen-based HRT with skeletal muscle transcriptome. Pathway analysis of muscle transcript profiles r…

Effect of Prolonged Physical Training on the Development of Connective Tissues in Growing Mice

1975

A rapid progress has taken place in the field of connective tissue chemistry during recent years. The structure and metabolism of collagen, elastin, glycosaminoglycans and pro-. teoglycans of different connective tissues have been extensively investigated. One of the main observations has been that large differences exist between various connective tissues [12]. For example, four different forms of collagen have been identified. The collagens in bone, cartilage, skin and basement membrane have either different amino acid composition in the a-chains or contain one or two similar a-chains in the triple helix. The scope of the connective tissue research has been extended also to skeletal muscl…

Importance of sarcopenia parameter changes after living donor liver transplantation

2017

The systemic role of muscle tissue is strengthened by the large system of hormones, chemokines and other mediators that constitute a dense network of communication between the skeletal muscle and the liver (1,2). This, associated with the evidence of a progressive malnutrition and depletion of muscle mass in end-stage liver disease (ESLD) patients, has led many to study the role of sarcopenia and its systemic effects in this setting, and to identify it as critical risk factor for post- liver transplantation (LT) mortality (3-5). Englesbe and colleagues found a direct correlation between central sarcopenia, measured by computerized tomography (CT), the total area of the psoas muscle (psoas a…

2021

Introduction (Neo-)adjuvant chemotherapy for breast cancer has a deleterious impact on muscle tissue resulting in reduced cardiorespiratory fitness, skeletal muscle mass and function. Physical exercise during treatment may counteract some of these negative effects. However, the effects of resistance training (RT) alone have never been explored. The present study aims to investigate if heavy-load RT during (neo-)adjuvant chemotherapy counteracts deleterious effects on skeletal muscle in women diagnosed with breast cancer. We hypothesize that (neo-)adjuvant treatment with chemotherapy will reduce muscle fiber size, impair mitochondrial function, and increase indicators of cellular stress and …

Muscle Biopsy; Processing and Evaluation

2014

Muscle biopsy is a diagnostic procedure to recognize myopathological lesions in skeletal muscle. It may be an open surgical procedure or performed by needle biopsy. The muscle biopsy ought to target a myopathologically affected muscle, chosen by clinical features and/or myoimaging. Preparative techniques entail histology, electron microscopy, enzyme histochemistry, and immunohistochemistry, but it is essential to leave additional tissue for possible subsequent biochemical and molecular investigations. The backbone of light microscopic, diagnostic studies is unfixed frozen muscle tissue with cross-sectioned muscle fibers. Correct archiving of biopsied muscle tissue for future diagnostic and …

Biomaterials and bioactive molecules to drive differentiation in striated muscle tissue engineering

2015

International audience; The generation of engineered tissues and organs has entered into the clinical practice in response to the chronic lack of organ donors. In particular, for the skeletal and cardiac muscles the translational potential of tissue engineering approaches has clearly been shown, even though the construction of these tissues lags behind others given the hierarchical, highly organized architecture of striated muscles. Failure of the cardiac tissue leads to cardiovascular diseases, which are the leading cause of death in the developed world (Di Felice et al., 2014). On the other hand, there are many clinical cases where the loss of skeletal muscle due to a traumatic injury, an…

G.P.199

2014

Our group has recently derived skeletal muscle from dermis-derived cells, by using an extracellular matrix that recreates the myogenic niche. After one week of differentiation, we observed isolated, twitching myotubes followed by spontaneous contractions of the entire tissue-engineered muscle construct. In vitro engineered myofibers expressed canonical markers, ultrastructure and electrophysiological characteristics of skeletal muscle. Interestingly, after one-month engineered muscle constructs showed progressive degradation of the myofibers concomitant with fatty infiltration, paralleling the natural course of muscular degeneration. However, we do not yet know how dermis-resident precursor…

Retraction: Alcohol consumption and hormonal alterations related to muscle hypertrophy: a review

2014

Detrimental effects of acute and chronic alcohol (ethanol) consumption on human physiology are well documented in the literature. These adversely influence neural, metabolic, cardiovascular, and thermoregulatory functions. However, the side effects of ethanol consumption on hormonal fluctuations and subsequent related skeletal muscle alterations have received less attention and as such are not entirely understood. The focus of this review is to identify the side effects of ethanol consumption on the major hormones related to muscle metabolism and clarify how the hormonal profiles are altered by such consumption.