Search results for "Muscle"
showing 10 items of 3397 documents
Comparative study of the rat uterine smooth muscle relaxant activity of three bisbenzyltetrahydroisoquinolines with tetrandrine
1993
Abstract The relaxant activity of three bisbenzyltetrahydroisoquinolines—obaberine, popisonine and lindoldhamine—was examined in rat isolated uterus and their inhibitory potencies were compared with that of tetrandrine. All alkaloids tested relaxed KCl-depolarized rat uterus and totally or partially inhibited oxytocin-induced rhythmic contractions. The degree of methylation of the free phenolic hydroxy groups and the loss of one diarylether bridge influence the potency of relaxant action of these alkaloids. Only alkaloids with absolute configuration 1R,1′S or 1R1′R acted intracellularly, promoting relaxation of contractile responses induced by oxytocin or vanadate in a Ca2+-free medium.
P.10.18 Common data elements for muscle biopsy reporting
2013
Physicians commonly utilize the muscle biopsy to assist in the diagnosis of neuromuscular diseases. However, there is no current standard for evaluating or reporting on findings, and the resulting variability can impede accurate diagnoses and limit the utility of the muscle biopsy as a tool for clinical care, research, and stratifying patients for clinical trials. The National Institutes of Neurological Disorders and Stroke (NINDS) recently launched a Common Data Element (CDE) in an effort to standardize neuromuscular data collected in clinical reports. For this study, the authors adapted the NINDS Muscle Biopsy CDE to generate a form for prospective muscle biopsy reporting (CDE-R). This fo…
Electrically induced torque decrease reflects more than muscle fatigue
2014
The aim of the study was to compare the fatigue induced by different electrical stimulation (ES) protocols. The triceps surae muscle of 8 healthy subjects was fatigued with 4 protocols (30 Hz-500 μs, 30 Hz-1 ms, 100 Hz-1 ms, and 100 Hz-500 μs), composed of 60 trains (4 s on-6 s off), delivered at an intensity evoking 30% of maximal voluntary contraction (MVC). Fatigue was quantified by ES and MVC torque decreases. The amplitude of the twitch delivered at the intensity and pulse width used in each fatiguing protocol (twitch at Istim ) was analyzed. All parameters decreased significantly after all protocols. The ES torque decrease correlated positively with the twitch decrease elicited at Ist…
Effects of electrical stimulation pattern on quadriceps isometric force and fatigue in individuals with spinal cord injury
2015
Introduction Variable frequency trains (VFT) or train combinations have been suggested as useful strategies to offset the rapid fatigue induced by constant frequency trains (CFT) during electrical stimulation. However, most studies have been of short duration with limited functional application in those with spinal cord injury (SCI). We therefore tested force and fatigue in response to VFT, CFT, and combined patterns in strength training-like conditions (6-s contractions). Methods Ten SCI individuals underwent either CFT or VFT patterns until target torque was no longer produced and then switched immediately to the other pattern. Results Target torque was reached more times when VFT was use…
Assessment of skeletal muscle fatigue of road maintenance workers based on heart rate monitoring and myotonometry
2006
Abstract Objective This research work is dedicated to occupational health problems caused by ergonomic risks. The research object was road building industry, where workers have to work very intensively, have long work hours, are working in forced/constrained work postures and overstrain during the work specific parts of their bodies. The aim of this study was to evaluate the work heaviness degree and to estimate the muscle fatigue of workers after one week work cycle. The study group consisted of 10 road construction and maintenance workers and 10 pavers aged between 20 and 60 years. Methods Physical load were analyzed by measuring heart rate (HR), work postures (OWAS) and perceived exertio…
The cardinal exercise stopper: Muscle fatigue, muscle pain or perception of effort?
2018
The capacity to sustain high-intensity aerobic exercise is essential for endurance performance. Therefore, it is important to understand what is the factor limiting time to exhaustion (TTE) in healthy and fit adults. In Study 1, maximal voluntary cycling power (MVCP) was measured in 11 volunteers before and immediately after a high-intensity TTE test on cycle ergometer. Cadence was 60 rpm in both the MVCP and TTE tests. Despite a 35% loss in MVCP, power produced during the final MVCP test (mean ± SD 469 ± 111 W) was significantly higher than the power required by the TTE test (269 ± 55 W) (P < 0.001). In Study 2, 12 participants performed a cold pressor test (CPT) to the limit of tolerance …
Sarcopenia and Covid-19: A New Entity?
2021
As the world comes into terms with the persistent existence of the coronavirus disease 19 (COVID-19) pandemic, the scientific and medical communities have started shifting their attention to the long-term side effects of the disease. Specialists have acknowledged that numerous COVID-19 survivors, especially those who suffered severe complications and endured prolonged bedrest, may require continuous monitoring and rehabilitative care. In this chapter, the authors discuss factors that may predispose individuals to acute sarcopenia secondary to COVID-19 infection or sarcopenic obesity secondary to altered diet and physical activity from prolonged confinement. Challenges in nutrition are highl…
Traditional vs daily undulling periodization in strength and local muscle endurance gains on trained men
2018
The aim of this study was to investigate the impact of different periodization models on strength and local muscle endurance. Twenty trained men (25.45 ± 2.984 years, 75.34 ± 6.05 kg, 177.25 ± 4.92 cm, 23.96 ± 1.64 kg . m-2) were randomly assigned in two groups: undulling periodization (UPG) and traditional periodization group (TPG), respectively. All the subjects performed one repetition maximum (1-RM) strength test and a local muscle endurance test (60% of 1-RM to failure) before, during and after experimental period. The UPG executed 30 workout sessions with daily modifications regarding intensity, volume and rest period length. The TGP was divided into 3 phases (10 workout sessions in e…
Neurodegenerative changes are prevented by Erythropoietin in the pmn model of motoneuron degeneration
2014
Motoneuron diseases are fatal neurodegenerative disorders characterized by a progressive loss of motoneurons, muscle weakness and premature death. The progressive motor neuronopathy (pmn) mutant mouse has been considered a good model for the autosomal recessive childhood form of spinal muscular atrophy (SMA). Here, we investigated the therapeutic potential of Erythropoietin (Epo) on this mutant mouse. Symptomatic or pre-symptomatic treatment with Epo significantly prolongs lifespan by 84.6% or 87.2% respectively. Epo preserves muscle strength and significantly attenuates behavioural motor deficits of mutant pmn mice. Histological and metabolic changes in the spinal cord evaluated by immunoh…
M-cadherin and its sisters in development of striated muscle
1999
Cadherins are calcium-dependent, transmembrane intercellular adhesion proteins with morphoregulatory functions in the development and maintenance of tissues. In the development of striated muscle, the expression and function of mainly M-, N-, and R-cadherin has been studied so far. While these three cadherins are expressed in skeletal muscle cells, of these only N-cadherin is expressed in cardiac muscle. In this review, M-, N-, and R-cadherin are discussed as important players in the terminal differentiation and possibly also in the commitment of skeletal muscle cells. Furthermore, reports are described which evaluate the essential role of N-cadherin in the formation of heart tissue.