Search results for "skeletal muscle"

The prognostic value of skeletal muscle index on clinical and survival outcomes after cytoreduction and HIPEC for peritoneal metastases from colorect…

2021

BACKGROUND Cytoreductive surgery (CRS) and hypertermic intraperitoneal chemotherapy (HIPEC) represent the most effective strategy to manage peritoneal metastases (PM). This systematic review and meta-analysis aimed to assess the impact of body composition on clinical outcomes in patients with PM. METHODS A systematic literature search was performed using Medline, Web of Science and EMBASE databases from inception to the 20st August 2020. Data were independently extracted by 3 authors. Newcastle-Ottawa Scale was used to assess quality and risk of bias of studies. Pooled analyses were performed using Mantel-Haenszel method to estimate overall effect size with mean differences or odd ratios (O…

Regulation of type IV collagen gene expression and degradation in fast and slow muscles during dexamethasone treatment and exercise.

2003

Glucocorticoids have anti-anabolic effects on many tissues and can cause muscle atrophy. However, their effects on type IV collagen gene expression and degradation in skeletal muscle have not been studied previously. Rats were treated daily with dexamethasone or saline. Half the groups of experimental and control animals were also subjected to daily endurance or uphill running exercise to determine the possible preventive effects of exercise. After an experimental period of 3 or 10 days, the extensor digitorum longus, soleus and tibialis anterior muscles were studied. Dexamethasone treatment for 10 days reduced muscle weight and type IV collagen mRNA abundance in all muscles. Gene expressio…

A versatile model of steady state O2 supply to tissue. Application to skeletal muscle

1990

A model of combined convective and diffusive O2 transport to tissue is suggested which allows for the calculation of PO2 distributions in a cuboid tissue region with arbitrary microvascular geometries and blood flows. Carrier-facilitated O2 diffusion in the erythrocytes and in the tissue and red blood cell reaction kinetics are considered. The model is based on analytical descriptions of the PO2 fields of single erythrocytes surrounded by carrier-free layers in an infinite three-dimensional space containing an O2 carrier such as myoglobin. These PO2 fields are overlaid to obtain a solution of the differential equation of diffusion in respiring tissue. The model has been applied to a situati…

Physical activity and health: Musculoskeletal issues

2007

Sarcopenia and osteoporosis, the complications of the age-related deterioration of the musculoskeletal system, result in increased risk of fracture, disability and death in old age. Consequently, the structure and function of skeletal muscle and bone and their adaptability are essential aspects of overall health, functional capacity and mobility during the whole lifespan. There is convincing clinical evidence that progressive resistance exercise training improves the properties of skeletal muscle in men and women across the age spectrum, thus providing a high reserve capacity for coping with the functional demands of physical tasks. Regarding bones, exercise is most effective during growth,…

Anti-Hypotensive Treatment and Endothelin Blockade Synergistically Antagonize Exercise Fatigue in Rats under Simulated High Altitude

2013

Rapid ascent to high altitude causes illness and fatigue, and there is a demand for effective acute treatments to alleviate such effects. We hypothesized that increased oxygen delivery to the tissue using a combination of a hypertensive agent and an endothelin receptor A antagonist drugs would limit exercise-induced fatigue at simulated high altitude. Our data showed that the combination of 0.1 mg/kg ambrisentan with either 20 mg/kg ephedrine or 10 mg/kg methylphenidate significantly improved exercise duration in rats at simulated altitude of 4,267 m, whereas the individual compounds did not. In normoxic, anesthetized rats, ephedrine alone and in combination with ambrisentan increased heart…

2020

Skeletal muscle atrophy is characterized by a decrease in muscle fiber size as a result of a decreased protein synthesis, which leads to degradation of contractile muscle fibers. It can occur after denervation and immobilization, and glucocorticoids (GCs) may also increase protein breakdown contributing to the loss of muscle mass and myofibrillar proteins. GCs are already used in vitro to induce atrophic conditions, but until now no studies with primary human skeletal muscle existed. Therefore, this study deals with the effects of the GC dexamethasone (dex) on primary human myoblasts and myotubes. After incubation with 1, 10, and 100 µM dex for 48 and 72 h, gene and protein expression analy…

Role of nitric oxide and nitric oxide synthases in experimental models of denervation and reinnervation.

2001

Nitric oxide (NO) is a short-living free molecule synthesized by three different isoforms of nitric oxide synthases (NOS)—neuronal NOS, endothelial NOS, and inducible NOS—associated with neuromuscular transmission, muscle contractility, mitochondrial respiration, and carbohydrate metabolism in skeletal muscle. Neuronal NOS is constitutively expressed at the muscle fiber sarcolemma linked to the dystrophin-glycoprotein complex and concentrated at the neuromuscular endplate. There is increasing evidence that altered expression of neuronal NOS plays a role in muscle fiber damage in neuromuscular diseases such as dystrophinopathies and denervating disorders. Although there have been some previo…

Sonographische Verlaufskontrolle nach experimenteller Muskeldenervierung

2008

AIM: To describe sonographical results following acute, experimental muscle denervation. METHOD: Denervation of the supraspinatus and infraspinatus muscles was performed in 28 New Zealand white rabbits by segmental resection of the suprascapular nerve. The changes in the sonographic image of the muscles were follow up and documented at short intervals over 2 months. RESULTS: The sonographically detectable changes following denervation follow a definite pattern. In addition to the reduction in muscle diameter, sonographical signs of denervation include an increase of echodensity and an inhomogeneity of echotexture that appeared on day 14 after injury and became more prominent at larger inter…

Morphology of Skeletal Muscle

2013

Skeletal muscle makes up the largest organ of the body, by both volume and weight, comprising more than 40 %. More than 500 diseases concern muscle tissue, the majority of which originate in muscle, others secondarily affect the muscle, foremost by denervation. The functional and structural dependence of skeletal muscle on innervation—that is, the peripheral and central nervous systems—renders muscle tissue unique and adds a dimension to the nosology, more obviously than in other organs. Therefore, diseases affecting muscle are also termed neuromuscular diseases. Within the nosological spectrum of the muscle parenchyma, which encompasses hereditary and acquired conditions, muscular dystroph…

STUDIES ON NORMAL AND DENERVATED SKELETAL MUSCLE CHROMATIN

1980

Publisher Summary This chapter presents studies on normal and denervated skeletal muscle chromatin. It has been reported that the inhibitors of RNA and protein synthesis can prevent the appearance of some biochemical modifications of muscle, generally induced by denervation. This observation suggests that the gene expression of muscle fiber is under motoneuron control. On the other hand, it is well known that in eukaryotic cells exists a close relationship between chromatin properties and the gene expression. In a study, some properties of normal and 7-days denervated muscle chromatin were investigated to establish whether the changes in protein metabolism in denervated skeletal muscle are …