Search results for "Biophysic"

Fructose 2,6-bisphosphate and glycolytic flux in skeletal muscle of swimming frog

1990

AbstractGlycolytic flux in skeletal muscle is controlled by 6-phosphofructokinase but how this is achieved is controversial. Brief exercise (swimming) in frogs caused a dramatic increase in the phosphofructokinase activator, fructose 2,6-bisphosphate, in working muscle. The kinetics of phosphofructokinase suggest that in resting muscle, the enzyme is inhibited by ATP plus citrate and that the increase in fructose 2,6-bisphosphate is part of the mechanism to activate phosphofructokinase when exercise begins. When exercise was sustained, fructose 2,6-bisphosphate in muscle was decreased as was the rate of lactate accumulation. Glycolytic flux and the content of fructose 2,6-bisphosphate appea…

Epithelium-derived inhibition of [3H]acetylcholine release from the isolated guinea-pig trachea

1990

To investigate presynaptic, regulatory mechanisms on parasympathetic nerve fibres innervating the airways, the release of newly-synthesized [3H]acetylcholine from the isolated trachea was studied. Reverse phase HPLC followed by liquid scintillation spectrometry was used to separate and quantify the radioactive compounds choline, phosphorylcholine and acetylcholine in the incubation medium and the tissue. During the incubation of the tracheae with [3H]choline a significant synthesis of [3H]acetylcholine (35,000 dpm/preparation) and [3H]phosphorylcholine (500,000 dpm/preparation) occurred. In epithelium-deficient tracheae the formation of [3H]phosphorylcholine was enhanced, whereas the conten…

Feasibility of future epidemiological studies on possible health effects of mobile phone base stations.

2006

The increasing deployment of mobile communication base stations led to an increasing demand for epidemiological studies on possible health effects of radio frequency emissions. The methodological challenges of such studies have been critically evaluated by a panel of scientists in the fields of radiofrequency engineering/dosimetry and epidemiology. Strengths and weaknesses of previous studies have been identified. Dosimetric concepts and crucial aspects in exposure assessment were evaluated in terms of epidemiological studies on different types of outcomes. We conclude that in principle base station epidemiological studies are feasible. However, the exposure contributions from all relevant …

A systematic review of physical fitness, physiological demands and biomechanical performance in equestrian athletes

2012

This article presents a systematic review of the literature investigating physical fitness, physiological demands and biomechanical performance in equestrian athletes. Three databases (SportsDiscus, CAB abstracts and PubMed) were searched to identify the literature. The main search term of ‘horse-riding’ was combined with eleven specific keywords (‘fitness’, ‘physiology’, ‘biomechanics’, ‘equestrian’, ‘athlete’, ‘co-ordination’, ‘heart rate’, ‘oxygen consumption’ ‘kinematic’ ‘EMG’ and ‘skill’). Exclusion criteria were: conference proceedings, abstracts, theses, and non-peer reviewed articles. Subsequently, 15 peer-reviewed papers were identified and included within this review. The main re…

Kinematics of shoulder abduction in the scapular plane

1995

In this paper the kinematics of arm abduction in the scapular plane of 38 healthy experimental subjects is reported. The ratio of the glenohumoral and the scapulothoracic components of the motion were determined and the influence of the abduction speed and of the external load on it were investigated. The investigation of the effect of abduction speed involved all 38 subjects. Each of them performed one slow and one fast abduction. Statistical analysis showed that there were large differences between individuals, but that for any one individual the abduction process is essentially reproducible. For the one individual there is a strong, linear relationship between glenohumeral and scapulotho…

Biomechanical and histological evaluation of abdominal wall compliance with intraperitoneal onlay mesh implants in rabbits: A comparison of six diffe…

2012

Abstract Background An ideal prosthetic mesh for incisional hernia repair should mimic the anisotropic compliance of the abdominal wall, and at lower loads should exhibit higher distensibility without impairment of safety at higher loads. This study evaluated the biomechanical properties of six meshes in a rabbit model. Methods New Zealand white rabbits were used for this study. Two meshes of the same brand (Ethicon Physiomesh™, Bard Composix ® L/P, Gore Dualmesh ® , Bard Sepramesh ® , Ethicon Proceed ® or Parietex™ Composite) were implanted into each animal for assessment of intra-abdominal hernia repair, with a total of ten meshes per group. Twelve weeks after implantation, the abdominal …

Coronary artery and bypass flow measurement—basic methodology and current status

1998

Pitfalls in whole body MRI with diffusion weighted imaging performed on patients with lymphoma: What radiologists should know

2016

The technological advances in radiological imaging and the relevance of a diagnostic tool that may reduce radiation-induced long-term effects have led to a widespread use of whole body magnetic resonance imaging (WB-MRI) with diffusion weighted imaging for oncologic patients. A lot of studies demonstrated the feasibility and reliability of WB-MRI as an alternative technique for lymphoma staging and response assessment during and after treatment. In this paper, taking advantage of our 2years of experience using WB-MRI for lymphoma, we discuss the main pitfalls and artifacts radiologists should know examining a WB-MRI performed on this typology of patients in order to avoid images misinterpre…

Uneven modulation of the annexin 1 system in osteoblast-like cells by dexamethasone

2007

AbstractWe tested whether glucocorticoids modulated osteoblast expression of the annexin 1 system, including the ligand and two G-coupled receptors termed formyl-peptide receptor (FPR) and FPR-like-1 (FPRL-1). In Saos-2 cells, rapid up-regulation of FPR mRNA upon cell incubation with dexamethasone (0.01–1μM) was observed, with significant changes as early as 2h and a more marked response at 24h; annexin 1 and FPRL-1 mRNA changes were more subtle. At the protein level, dexamethasone provoked a rapid externalization of annexin 1 (maximal at 2h) followed by delayed time-dependent changes in the cell cytosol. Saos-2 cell surface expression of FPR or FPRL-1 could not be detected, even when dexam…

Reliability of isokinetic assessment of shoulder-rotator strength: a systematic review of the effect of position.

2011

Context:Isokinetic assessment of shoulder internal- (IR) and external-rotator (ER) strength is commonly used with many different postures (sitting, standing, or supine) and shoulder positions (frontal or scapular plane with 45° or 90° of abduction).Objective:To conduct a systematic review to determine the influence of position on the intersession reliability of the assessment of IR and ER isokinetic strength, to identify the most reliable position, and to determine which isokinetic variable appears to be most stable in intersession reliability.Evidence Acquisition:A systematic literature search through MEDLINE and Pascal Biomed databases was performed in October 2009. Criteria for inclusion…