Search results for " Muscle"
showing 10 items of 1495 documents
Oxidative stress leads to cholesterol accumulation in vascular smooth muscle cells.
1999
The transformation of macrophages and smooth muscle cells into foam cells by modified low-density lipoproteins (LDL) is one of the key events of atherogenesis. Effects of free radicals have mainly been studied in LDL, and other than toxicity, data dealing with direct action of free radicals on cells are scarce. This study focused on the direct effects of free radicals on cholesterol metabolism of smooth muscle cells. A free radical generator, azobis-amidinopropane dihydrochloride, was used, and conditions for a standardized oxidative stress were set up in vascular smooth muscle cells. After free radical action, the cells presented an accumulation of cholesterol that appeared to be the resul…
Potential role of the neuropeptide CGRP in the induction of differentiation of rat hepatic portal vein wall.
2005
The media of the rat hepatic portal vein is composed of an internal circular muscular layer (CL) and an external longitudinal muscular layer (LL). These two perpendicular layers differentiate progressively from mesenchymal cells within the first month after birth. In this paper, we studied the development of calcitonin gene-related peptide (CGRP) innervation during post-natal differentiation of the vessel. We show that CGRP innervation is already present around the vessel at birth in the future adventitia but far from the lumen of the vessel. Progressively, CGRP immunoreactive fibers reached first LL then CL. CL by itself become only innervated at day 14 after birth. This corresponds to the…
Insulin resistance aggravates atherosclerosis by reducing vascular smooth muscle cell survival and increasing CX3CL1/CX3CR1 axis.
2014
Aims Insulin resistance (IR) is a major risk factor for cardiovascular disease and atherosclerosis. Life-threatening acute events are mainly due to rupture of unstable plaques, and the role of vascular smooth muscle cells (VSMCs) in this process in IR, Type 2 diabetes mellitus, and metabolic syndrome (T2DM/MetS) has not been fully addressed. Therefore, the role of VSMC survival in the generation of unstable plaques in T2DM/MetS and the involvement of inflammatory mediators was investigated. Methods and results Defective insulin receptor substrate 2 (IRS2)-mediated signalling produced insulin-resistant VSMCs with reduced survival, migration, and higher apoptosis than control cells. Silencing…
Vascular effects of progesterone: Role of cellular calcium regulation
2001
Abstract —Vascular actions of progesterone have been reported, independently of estrogen, affecting both blood pressure and other aspects of the cardiovascular system. To study possible mechanisms underlying these effects, we examined the effects of P in vivo in intact rats and in vitro in isolated artery and vascular smooth muscle cell preparations. In anesthetized Sprague-Dawley rats , bolus intravenous injections of P (100 μg/kg) significantly decreased pressor responses to norepinephrine (0.3 μg/kg). In vitro, progesterone (10 −8 to 10 −5 mmol/L) produced a significant, dose-dependent relaxation of isolated helical strips, both of rat tail artery precontracted with KCl (60 mmol/L) or a…
Hydatid cyst in the vastus lateralis muscle: a case report
2017
Hydatidosis is a zoonotic disease; human infection occurs through the consumption of food and water contaminated with the eggs of parasites of the Echinococcus type. While the liver is the most common site of infection, involvement of the musculoskeletal system is extremely rare. In the context of musculoskeletal involvement, the spine is the most commonly infected site, while the muscles are rarely infected and account for approximately <1% of cases. It has been suggested that muscles provide an unsuitable environment for the parasite, because of the presence of lactic acid. The cysts appear as slow-growing masses of soft tissue, and signs of inflammation and fistulization often coexist. W…
Inspiratory and Lower-Limb Strength Importance in Mountain Ultramarathon Running. Sex Differences and Relationship with Performance
2020
The study was aimed at comparing lower-limb strength and respiratory parameters between male and female athletes and their interaction with performance in a 107 km mountain ultramarathon. Forty seven runners (29 males and 18 females
Dropped head as an unusual presenting sign of myasthenia gravis.
2007
Prominent or isolated weakness of cervical extensor muscles is a relatively rare clinical sign. Commonly, this is known as "dropped-head syndrome". This abnormal flexion of the head may occur in a variety of neuromuscular diseases and in a few non-neurological disorders as well. The case we describe concerns a 61-year-old woman with dropped-head syndrome as the unique complaint of myasthenia gravis.
Effects of strength and endurance training on thigh and leg muscle mass and composition in elderly women
1995
The effects of 18 wk of intensive strength and endurance training on knee extensor, knee flexor, and lower leg muscle mass and composition were studied in 76- to 78-yr-old women. Muscle cross-sectional area (CSA), lean tissue CSA, and relative proportion of fat were determined using computed tomography. The strength-trained women increased their total muscle lean tissue CSA of the thigh (1.5%; P = 0.035), quadriceps CSA (4.5%; P = 0.021), quadriceps lean tissue CSA (5.8%, P = 0.009), and mean Hounsfield unit of the lower leg muscles (11.2%; P = 0.035) compared with the changes that occurred in the control group during the experiment. The change in quadriceps lean tissue CSA because of the …
Quantitative ultrasonography of muscle: Detection of adaptations to training in elderly women
1996
Abstract Objective: To develop quantitative ultrasonography in studying the adaptation of quadriceps muscle mass and composition to short-term physical training and rehabilitation in elderly women. Design: Randomized control trial. Setting: Measurements in a research laboratory and training in a fitness center and sports hall. Participants: Forty-two women, aged 76 to 78 years, with no indications against intensive physical exercise, randomly assigned to strength ( n = 16), endurance ( n = 15), and control ( n = 11) groups. Twelve subjects from the strength, 12 from the endurance, and 11 from the control group completed the study. Intervention: Supervised physical training 3 times a week fo…
The significance of the triceps surae muscle action as a determinant in the biomechanical genesis of ski fall injuries
1985
In an epidemiologic study of 700 ski fall injuries YOUNG /1/ established a classification of the different fall modes involved. In more than 60 % of all falls that lead to an injury he found a forward bending motion of the body which is frequently coupled with a twisting of the body around the lower extremity. This clearly shows the importance of the forward motion component of the skier’s body in ski fall traumatology. The type of injury and its location depend on the action of the ski binding system. If the binding does not release in a ski fall, the fraction of injuries in the lower extremity amounts to nearly 100 %. If the binding does release, however, the injuries ocurring in this cas…