Search results for "physiologic"
showing 10 items of 2593 documents
Effect of intravenous flecainide on atrial vulnerability in man.
1985
Sixteen patients were investigated by means of programmed atrial stimulation at 2 different driving rates: 100/min and 120/min. All patients had an increased atrial vulnerability at both driving rates. After the administration of intravenous flecainide (1 mg/kg bodyweight as a bolus, followed by the same amount infused over a period of 20 minutes), the increased vulnerability was abolished in 11 and 9 patients, respectively. In the remaining patients the rate of induced atrial tachyarrhythmia decreased. These findings correlate with a significant prolongation of the effective refractory period of the right atrium and a corresponding significant shortening of its relative refractory period. …
Early detection of the risk of developing psychiatric disorders: a study of 461 Chinese university students under chronic stress
2019
Chronic stress, a characteristic of modern time, has a significant impact on general health. In the context of psychiatric disorders, insufficient coping behavior under chronic stress has been linked to higher rates of (1) depressive symptoms among subjects of the general population, (2) relapse among patients under treatment for clinical depression, and (3) negative symptoms among subjects with an elevated vulnerability to psychosis. In this normative study we assessed basic coping behavior among 461 Chinese freshman university students along with their consumption behavior and general health in terms of regular exercises, physical health, psychosomatic disturbances, and mental health. The…
MRI and neurophysiology in vestibular paroxysmia: contradiction and correlation
2013
Background Vestibular paroxysmia (VP) is defined as neurovascular compression (NVC) syndrome of the eighth cranial nerve (N.VIII). The aim was to assess the sensitivity and specificity of MRI and the significance of audiovestibular testing in the diagnosis of VP. Methods 20 VP patients and, for control, 20 subjects with trigeminal neuralgia (TN) were included and underwent MRI (constructive interference in steady-state, time-of-flight MR angiography) for detection of a NVC between N.VIII and vessels. All VP patients received detailed audiovestibular testing. Results A NVC of N.VIII could be detected in all VP patients rendering a sensitivity of 100% and a specificity of 65% for the diagnosi…
Neuromuscular and physiological variables evolve independently when running immediately after cycling
2015
International audience; During the early period of running after cycling, EMG patterns of the leg are modified in only some highly trained triathletes. The majority of studies have analysed muscle EMG patterns at arbitrary, predetermined time points. The purpose of this study was to examine changes to EMG patterns of the lower limb at physiologically determined times during the cycle-run transition period to better investigate neuromuscular adaptations. Six highly trained triathletes completed a 10 min isolated run (IR), 30 min of rest, then a 20 min cycling procedure, before a 10 min transition run (C-R). Surface EMG activity of eight lower limb muscles was recorded, normalised and quantif…
Glutathione levels in blood from ataxia telangiectasia patients suggest in vivo adaptive mechanisms to oxidative stress
2007
Objective: To evaluate an in vivo pro-oxidant state in patients with ataxia telangiectasia (AT). Methods: A set of oxidative stress endpoints were measured in 9 AT homozygotes, 16 AT heterozygotes (parents) and 83 controls (grouped in age ranges as for patients and parents, respectively). The following analytes were measured: (a) leukocyte 8-hydroxy-2-deoxyguanosine (8-OHdG); (b) blood glutathione (GSSG and GSH); and (c) plasma levels of glyoxal (Glx) and methylglyoxal (MGlx). Results: AT patients displayed a significant decrease in blood GSSG (p=0.012) and in MGlx plasma concentrations (P=0.012). A nonsignificant decrease in the GSSG:GSH ratio (p = 0.1) and a non-significant increase in 8-…
Torsional eye movement responses to monaural and binaural galvanic vestibular stimulation: side-to-side asymmetries.
2003
Vestibular stimulation by head accelerations always involves multisensory activation of the vestibular, somatosensory, and visual systems. Over the past few years, galvanic vestibular stimulation (GVS) has become increasingly popular for testing vestibular function for clinical and research purposes. Although GVS provides a nonphysiological stimulation, it is more selective than natural head accelerations and is thus an attractive tool for such tests. Eye movement responses elicited by GVS mainly consist of torsional and horizontal components, as first described by Hitzig in 1871. Animal experiments have shown that GVS increases the vestibular afferent spike frequency at the cathodal site a…
Effects of prolonged hypertrophic resistance training on acute endocrine responses in young and older men.
2015
The present study investigated changes in acute serum hormone responses to a resistance exercise bout following a prolonged period of hypertrophic resistance training in young (YM) and older men (OM). Subjects performed a 5 × 10RM leg press exercise protocol before and after 20 weeks of hypertrophic resistance training. In YM, the acute responses in growth hormone were greater compared with before training (p < .05), and cortisol concentration did not increase after training. Endocrine responses in OM were similar before and after training. Greater acute growth hormone responses after training were associated with larger gains in lean mass in the entire subject group (r = .596, p = .019)…
Decline in motor prediction in elderly subjects: right versus left arm differences in mentally simulated motor actions.
2008
This study investigates the effects of age upon the temporal features of executed and imagined movements performed with the dominant (D; right) and nondominant (ND; left) arms. Thirty right-handed subjects were divided into two groups: (i) the young group (n=15; mean age: 22.5+/-2.5 years) and (ii) the elderly group (n=15; mean age: 70.2+/-2.2 years). The motor task, involving arm pointing movements among four pairs of targets (.5cm, 1cm, 1.5cm and 2cm), imposed strong spatiotemporal constraints. During overt performance, young and elderly subjects modulated movement duration according to the size of targets, despite the fact that movement speed decreased with age as well as in the left arm…
Subjective, behavioral, and physiological responses to the rubber hand illusion do not vary with age in the adult phase.
2018
[EN] The Rubber Hand Illusion (RHI) is a perceptual illusion that enables integration of artificial limbs into the body representation through combined multisensory integration. Most previous studies investigating the RHI have involved young healthy adults within a very narrow age range (typically 20-30 years old). The purpose of this paper was to determine the influence of age on the RHI. The RHI was performed on 93 healthy adults classified into three groups of age (20-35 years old, N = 41; 36-60 years old, N = 28; and 61-80 years old, N = 24), and its effects were measured with subjective (Embodiment of Rubber Hand Questionnaire), behavioral (proprioceptive drift), and physiological (cha…
Effects of amino acids supplement on physiological adaptations to resistance training.
2009
KRAEMER, W. J., D. L. HATFIELD, J. S. VOLEK, M. S. FRAGALA, J. L. VINGREN, J. M. ANDERSON, B. A. SPIERING, G. A. THOMAS, J. Y. HO, E. E. QUANN, M. IZQUIERDO, K. HAKKINEN, and C. M. MARESH. Effects of Amino Acids Supplement on Physiological Adaptations to Resistance Training. Med. Sci. Sports Exerc., Vol. 41, No. 5, pp. 1111-1121, 2009. Introduction: Previous research has demonstrated that ingestion of essential amino acids and their metabolites induce anabolic effects with the potential to augment gains in lean body mass and strength after resistance exercise training. Purpose: The purpose of the present study was to examine the effects of an essential amino acid-based formula (Muscle Armor…