Search results for "contraction"
showing 10 items of 1092 documents
Effect of histamine and histamine analogues on human isolated myometrial strips.
1992
1. The effect of histamine and histamine H1- and H2-receptor agonists on isolated myometrium strips of premenopausal women has been examined. The effect of acetylcholine was also determined. 2. Histamine, 2-pyridylethylamine, 4-methylhistamine and acetylcholine, but not dimaprit, produced a concentration-related contractile response in human isolated myometrial strips. Histamine also produced a further contraction in human isolated myometrial strips precontracted with KCl (55 mM). 3. The contractile response to histamine was antagonized by the histamine H1-receptor antagonist, clemizole (0.1 microM) but was potentiated by the histamine H2-receptor antagonist, ranitidine (10 microM). Clemizo…
Effects of muscular exercise on erythrocyte adenosine triphosphate concentration in patients with insulin-dependent diabetes mellitus.
1987
Type I diabetes mellitus represents a metabolic disorder in which intracellular glycolytic pathway is inhibited by insulin deficiency, with the subsequent decreased availability of energetic substrates such as ATP. Some aspects of the energetic metabolism in response to an intensive demand (muscular exercise) were investigated, in a group of 10 ketotic diabetic patients, by measuring erythrocyte adenosine triphosphate (ATP) and blood glucose, free fatty acids (FFA) and lactate levels. In the diabetic subjects, in comparison with normal subjects, the decreased levels of erythrocyte ATP at rest did not increase after exercise, while the increased levels of FFA at rest did not diminish after e…
Impaired muscle strength in female adolescents and young adults surviving leukemia in childhood
1993
Background. With the improving cure rate in childhood malignancies, increasing interest has been focused on long-term survivors. To evaluate late sequelae of childhood leukemia, the muscle strength of 43 young female survivors was investigated and compared with that of 69 healthy age-matched women. The patients had been off therapy for 1 to 19 years. Methods. The anthropometric characteristics measured were height and weight, and body mass index was calculated. The maximal isometric strengths for elbow flexion, knee extension, and hand grip were measured on a special dynamometer chair. Dynamic muscular endurance was measured by pushup and situp tests. Results. The mean height of the patient…
Importance of Patella, Quadriceps Forces, and Depthwise Cartilage Structure on Knee Joint Motion and Cartilage Response During Gait
2015
In finite-element (FE) models of the knee joint, patella is often omitted. We investigated the importance of patella and quadriceps forces on the knee joint motion by creating an FE model of the subject's knee. In addition, depthwise strains and stresses in patellar cartilage with different tissue properties were determined. An FE model was created from subject's magnetic resonance images. Knee rotations, moments, and translational forces during gait were recorded in a motion laboratory and used as an input for the model. Three material models were implemented into the patellar cartilage: (1) homogeneous model, (2) inhomogeneous (arcadelike fibrils), and (3) random fibrils at the superficia…
Muscle Inactivity and Activity Patterns after Sedentary-Time Targeted Randomized Controlled Trial
2014
Purpose: Interventions targeting sedentary time are needed. We used detailed EMG recordings to study the short-term effectiveness of simple sedentary time-targeted tailored counseling on the total physical activity spectrum. Methods: This cluster randomized controlled trial was conducted between 2011 and 2013 (InPact, ISRCTN28668090), and short-term effectiveness of counseling is reported in the present study. A total of 133 office workers volunteered to participate, from which muscle activity data were analyzed from 48 (intervention, n = 24; control, n = 24). After a lecture, face-to-face tailored counseling was used to set contractually binding goals regarding breaking up sitting periods …
Caffeine Increases Strength and Power Performance in Resistance-trained Females During Early Follicular Phase
2020
The effects of 4 mg·kg−1caffeine ingestion on strength and power were investigated for the first time, in resistance-trained females during the early follicular phase utilizing a randomized, double-blind, placebo-controlled, crossover design. Fifteen females (29.8 ± 4.0 years, 63.8 ± 5.5 kg [mean ± SD]) ingested caffeine or placebo 60 minutes before completing a test battery separated by 72 hours. One-repetition maximum (1RM), repetitions to failure (RTF) at 60% of 1RM, was assessed in the squat and bench press. Maximal voluntary contraction torque (MVC) and rate of force development (RFD) were measured during isometric knee extensions, while utilizing interpolated twitch technique to measu…
Kardiale MRT : Änderungen der normalisierten myokardialen Gadolinium-Anreicherung über die Zeit nach Kontrastmittelinjektion in Patienten mit akuter …
2011
PURPOSE An increased normalized gadolinium accumulation (NGA) in the myocardium during early washout has been used for the diagnosis of acute myocarditis (AM). Due to the fact that the pharmacokinetics of contrast agents are complex, time-related changes in NGA after contrast injection are likely. Because knowledge about time-related changes of NGA may improve the diagnostic accuracy of MR, our study aimed to estimate the time course of NGA after contrast injection in patients as well as in healthy volunteers. MATERIALS AND METHODS An ECG-triggered inversion recovery SSFP sequence with incrementally increasing inversion times was repetitively acquired over the 15 minutes after injection of …
Bronchial reactivity and intracellular magnesium: a possible mechanism for the bronchodilating effects of magnesium in asthma
1998
1.Increased bronchial smooth muscle contractility with consequent bronchial hyperreactivity are characteristic physiopathological events of asthma. Since magnesium intervenes in calcium transport mechanisms and intracellular phosphorylation reactions, it constitutes an important determinant of the contraction/relaxation state of bronchial smooth muscle. In the present study we investigated the relationship between bronchial reactivity, assessed by methacholine-provocation test, and magnesium concentrations both at extracellular and intracellular levels measured by spectrophotometry. Twenty-two patients with mild-to-moderate asthma and 38 non-asthmatic subjects with allergic rhinitis (24 all…
The Effect of Nitrazepam on Manual Skill, Grip Strength, and Reaction Time with Special Reference to Subjective Evaluation of Effects on Sleep
1978
The effects of 5 and 10 mg oral nitrazepam doses on manual skills, grip strength, and reaction time 8 hours after ingestion of the drugs were studied in 34 healthy female volunteers aged 19-22 years. 5 mg nitrazepam caused a slight but insignificant decrease in psychomotor skills. With 10 mg psychomotor skills were influenced significantly. Grip strength and reaction time were not influenced either by the 5 or 10 mg doses. The investigators corroborate the value of the established effects of nitrazepam as a hypnotic, but recommend that caution should be excercised in prescribing the drug as a hypnotic (especially in doses exceeding 5 mg) to work-aged subjects as there is a risk of significa…
Cross-sectional study of quadriceps properties and postural stability in patients with chronic stroke and limited vs. non-limited community ambulatio…
2019
Background: Changes in the paretic-side metabolism post-stroke and quadriceps muscle mechanical properties favour muscle wasting, affecting postural instability and walking impairment. Further clar...