Search results for "Muscle"
showing 10 items of 3397 documents
MUSCLE BIOENERGETIC ABNORMALITY IN MYOTONIC-DYSTROPHY - A SECONDARY MITOCHONDRIAL DISORDER
1993
International audience; Abstract: The thenar muscles and gastrocnemius of a patient with myotonic dystrophy were investigated, at rest, by phosphorus nuclear magnetic resonance spectroscopy. A decrease in phosphocreatine level and an increase in inorganic phosphate and phosphodiester levels were found in the gastrocnemius, which was clinically spared, whilst the thenar muscles, which were wasted and affected by myotonia, exhibited only an increased inorganic phosphate level and an elevated pH. These findings were comparable with those found in other muscular disorders, such as Duchenne's and Becker's dystrophies, as well as in limb girdle dystrophy. They suggested that the abnormalities obs…
Aberrant glycosylation of alpha-dystroglycan causes defective binding of laminin in the muscle of chicken muscular dystrophy.
2005
Dystroglycan is a central component of dystrophin-glycoprotein complex that links extracellular matrix and cytoskeleton in skeletal muscle. Although dystrophic chicken is well established as an animal model of human muscular dystrophy, the pathomechanism leading to muscular degeneration remains unknown. We show here that glycosylation and laminin-binding activity of alpha-dystroglycan (alpha-DG) are defective in dystrophic chicken. Extensive glycan structural analysis reveals that Galbeta1-3GalNAc and GalNAc residues are increased while Siaalpha2-3Gal structure is reduced in alpha-DG of dystrophic chicken. These results implicate aberrant glycosylation of alpha-DG in the pathogenesis of mus…
Duchenne Muscular Dystrophy (DMD): Should it be Considered a Systemic Disease?
2016
Duchenne muscular dystrophy (DMD) is an X-linked muscle disease characterized by progressive skeletal muscle loss and development of respiratory failure due to involvement of respiratory muscles. Similar to human DMD, the mdx mouse model lacks dystrophin but is characterized by relatively mild muscle injury, allowing testing the effects of mild endurance exercise training on dystrophic skeletal muscle. We were interested to study the effects of exercise training on airway cells in trained mdx mice by applying the same protocol previously tested in Swiss mice. We found that mdx mice showed little airway inflammation associated with training, but developed increasing apoptosis of airway cells…
Influence of Aerobic Exercise After Static Stretching on Flexibility and Strength in Plantar Flexor Muscles
2020
Aerobic exercise could improve stretch-induced strength deficits. However, mechanisms of the improvement were unclear. The purpose of the study was to examine the effects of aerobic exercise after static stretching (SS) on flexibility and isometric strength in ankle plantar-flexor muscles. Fifteen healthy males received two interventions after SS of their ankle plantar-flexor muscles for 5 min. One was aerobic exercise for 10-min on a cycling ergometer, and the other was a 10-min rest as a control. Range of motion (ROM) of ankle dorsiflexion, passive torque at terminal ROM, muscle-tendon unit (MTU) stiffness, muscle tendon junction displacement, peak torque of ankle plantarflexion, and the …
Effect of Training-Induced Changes in Achilles Tendon Stiffness on Muscle–Tendon Behavior During Landing
2018
During rapid deceleration of the body, tendons buffer part of the elongation of the muscle–tendon unit (MTU), enabling safe energy dissipation via eccentric muscle contraction. Yet, the influence of changes in tendon stiffness within the physiological range upon these lengthening contractions is unknown. This study aimed to examine the effect of training-induced stiffening of the Achilles tendon on triceps surae muscle–tendon behavior during a landing task. Twenty-one male subjects were assigned to either a 10-week resistance-training program consisting of single-leg isometric plantarflexion (n = 11) or to a non-training control group (n = 10). Before and after the training period, plantarf…
In vivo muscle mechanics during normal locomotion is dependent on movement amplitude and contraction intensity
2001
The effects of movement amplitude and contraction intensity on triceps surae and quadriceps femoris muscle function were studied during repetitive hopping. In vivo forces from Achilles and patellar tendons were recorded with the optic fibre technique from eight volunteers. The performances were filmed (200 Hz) to determine changes in muscle-tendon unit length and velocity. When hopping with a small amplitude (23° knee flexion during the ground contact phase), the Achilles tendon was primarily loaded whereas patellar tendon forces were greater in large-amplitude hopping (56° knee flexion). In spite of the different magnitudes of stretch in the quadriceps femoris muscle, the stretching veloci…
Association between Neck/Shoulder Pain and Trapezius Muscle Tenderness in Office Workers
2014
Background. Neck/shoulder pain is a common musculoskeletal disorder among adults. The pain is often assumed to be related to muscular tenderness rather than serious chronic disease. Aim. To determine the association between neck/shoulder pain intensity and trapezius muscle tenderness in office workers. Methods. 653 employees from two large office workplaces in Copenhagen, Denmark, replied to a questionnaire on health and working conditions (mean: age 43 years, body mass index 24 kg·m−2, computer use 90% of work time, 73% women). Respondents rated intensity of neck/shoulder pain during the previous three months on a scale of 0–10 and palpable tenderness of the upper trapezius muscle on a sca…
Identifying and Assessing Inter-Muscular Fat at the Distal Diaphyseal Femur Measured by Peripheral Quantitative Computed Tomography (pQCT)
2021
INTRODUCTION Inter/intramuscular fat can be assessed with peripheral Quantitative Computed Tomography (pQCT) and is of interest as an indicator of ‘muscle quality’. Typical pQCT scan sites (forearm, lower leg) have a low amount of inter/intramuscular fat, however distal diaphyseal femur scan sites with conspicuous inter/intramuscular fat have been identified as potentially more prudent scan sites, even in healthy adolescents. However, current state of the art analysis methods require labour-intensive manual segmentation of the scan. The purpose of the present study was to evaluate the reliability of a novel open source automated enclosing convex polygon approach (source code https://github.…
Combined effect of AAV-U7-induced dystrophin exon skipping and soluble activin Type IIB receptor in mdx mice.
2012
Adeno-associated virus (AAV)-U7-mediated skipping of dystrophin-exon-23 restores dystrophin expression and muscle function in the mdx mouse model of Duchenne muscular dystrophy. Soluble activin receptor IIB (sActRIIB-Fc) inhibits signaling of myostatin and homologous molecules and increases muscle mass and function of wild-type and mdx mice. We hypothesized that combined treatment with AAV-U7 and sActRIIB-Fc may synergistically improve mdx muscle function. Bioactivity of sActRIIB-Fc on skeletal muscle was first demonstrated in wild-type mice. In mdx mice we show that AAV-U7-mediated dystrophin restoration improved specific muscle force and resistance to eccentric contractions when applied a…
Acupuncture in the treatment of temporomandibular disorders, facial pain, and postural neuromuscular disorders. Presentation of a clinical case
2021
Abstract Background and objectives Temporomandibular disorders have a multifactorial etiology and involve the masticatory muscles, temporomandibular joint and associated structures. Therefore, different treatments are proposed and used. The aim of this paper is the use of acupuncture to treat temporomandibular disorders and associated symptoms. This article presents a clinical case study of a 39-year-old patient who presented temporomandibular disorders and headache of muscular origin. Results After 10 acupuncture sessions, the results were highly satisfactory, with complete relief of headache pain and absence of joint disorders. These results suggest the efficacy of acupuncture in the symp…