Search results for " Autonomic"
showing 10 items of 300 documents
Evaluation of esophagogastric junction relaxation by 4-second Integrated Relaxation Pressure in achalasia using High Resolution Manometry with water-…
2014
Background Relaxation of the esophagogastric junction (EGJ) is now evaluated calculating 4-second integrated relaxation pressure (4-s IRP) by high resolution manometry (HREPT). Solid-state catheters have been used to define abnormal values. Our aim was to evaluate 4-s IRP in esophageal achalasia using HREPT with perfused catheters. Methods From June 2009 to June 2013, 936 HREPT studies have been performed in our unit. Of these, 194 patients having treated achalasia were excluded. Control group was constituted by 695 patients without achalasia, and 47 patients with untreated achalasia constituted the study group. HREPT was performed with water-perfused catheters. To establish the cut-off val…
Circadian variations in antigen-specific proliferation of human T lymphocytes and correlation to cortisol production.
1995
Cortisol is a well-known immunosuppressant when used therapeutically. The present investigation was set out to study if diurnal variations in endogenous cortisol production are reflected by changes in proliferative responses of human lymphocytes to either a mitogen (phytohemagglutinin-A, PHA) or an antigen (tetanus toxoid, TT) stimulus. The study included eight healthy volunteers. Blood was withdrawn at 0200, 0600, 1000, and 1800h for preparation of lymphocytes and determination of cortisol in plasma. Isolated cells were incubated without (baseline activity) or with inclusion of either 1 micrograms PHA or 10 micrograms TT. Proliferation was measured by labelling with 3H-thymidine for 16 h o…
Acute stress impairs reward positivity effect in probabilistic learning
2019
Decision making based on feedback learning requires a series of cognitive processes, including estimating the probability of particular outcomes and modulating expectations between expected versus actual outcomes. It has been suggested that stress affects decision making and subsequent processing of feedback valence and magnitude. However, less is known about the effect of acute stress on reward expectancy. In the current study, participants performed a probabilistic learning task, in which they learned an association between response and feedback within different reward expectancy trials (30% and 70%) under the conditions of stress (threat of shock) and safety (no shock). We recorded event…
Scoring Criteria for Electrodermal Habituation: Further Research
1988
In the context of Levinson and Edelberg's critique of scoring criteria for electrodermal habituation, the present study examined the question of whether trials-to-habituation scores based on two no-response trials are superior to scores based on three no-response trials. Male students (N=120) performed two identical habituation experiments on two consecutive days and their skin conductance responses based on a short latency window of 1–3 s were analyzed. In each experiment subjects received 20 presentations of a 1000 Hz tone at 65dB. Results showed that three-trials scores were higher overall and that the distributions of three- and two-trials scores differed. On the other hand, the twoscor…
Effects of competition and its outcome on serum testosterone, cortisol and prolactin.
1999
In various species, competitive encounters influence hormonal responses in a different way depending on their outcome, victory or defeat. This study aimed to investigate the effects of sports competition and its outcome on hormonal response, comparing it with those displayed in situations involving non-effort and non-competitive effort. To this end, serum testosterone (T), cortisol (C) and prolactin (PRL) were measured in 26 judoists who participated in three sessions (control, judo fight and ergometry). The relationship between hormonal changes and psychological variables before and after the fight were also analysed. Our results showed a hormonal response to competition, which was especia…
Switching on the deep brain stimulation: effects on cardiovascular regulation and respiration.
2011
Abstract Background Objective of this study was to evaluate the acute cardiovascular and respiratory effects of switching on the deep brain stimulation in the follow up of nine Parkinson's disease patients with subthalamic nucleus stimulation and six cluster headache patients with posterior hypothalamic area stimulation. Methods Systolic and diastolic blood pressure, heart rate, and respiratory rate were monitored continuously during supine rest in both groups. Each patient was assessed in two conditions: resting supine with stimulator off and with stimulator on. Results In supine resting condition switching on the DBS induced no significant changes ( p > 0.05) in systolic and diastolic bl…
Experimental and methodological factors affecting test-retest reliability of amygdala BOLD responses.
2018
Previous studies reported poor to fair test-retest reliability of amygdala BOLD responses to emotional stimuli. However, these findings are very heterogeneous across and within studies. The present study sought to systematically examine experimental and methodological factors that contribute to this heterogeneity. Forty-six young subjects were scanned twice with a mean test-retest interval of 7 weeks. We compared amygdala reliability across three tasks: A face-matching task, passive viewing of emotional faces, and passive viewing of emotional scenes. We also explored whether extraction of physiological noise can affect the stability of amygdala responses. We assessed test-retest reliability…
Chemically and electrically induced sweating and flare reaction
2004
Both thin afferent (nociceptors) and efferent (sympathetic sudomotor) nerve fibers can be activated electrically and chemically, resulting in neurogenic erythema and sweating. These reactions have been used before to assess the impairment of sympathetic and nociceptor fibers in humans. In this study, electrically induced sweating and erythema were assessed simultaneously in the foot dorsum and thigh, and were compared to chemically induced activation. Reproducible intensity-response relations (stimulation intensities 0-30 mA, 1 Hz) were obtained from 32 subjects. The steepest increase of the sweat response was induced at lower intensities as compared to that of the erythema (18.3 mA vs. 25.…
Increased cortisol and decreased right ear advantage (REA) in dichotic listening following a negative mood induction.
2005
This study aimed to evaluate neuroendocrine responses and changes in perceptual asymmetry following an induced negative affect. Cortisol increasing in response to negative affect has been reported, while current brain models of emotion processing link negative affect to the right hemisphere. In this study, the Velten Mood Induction Procedure was used to generate neutral or negative affect in 44 healthy subjects. The PANAS scales were used to assess self-reported mood. A consonant-vowel dichotic listening (DL) test was applied after the neutral and negative affect inductions, and levels of salivary cortisol were determined by radioimmunoassay. For the negative affect condition, and congruent…
Computerized brain tomography measures compared with spontaneous and suppressed plasma cortisol levels in major depression.
1989
We determined brain density and ventricular measurements with computerized tomography (CT) in 33 depressed patients and compared the results with basal plasma cortisol and its suppressibility by dexamethasone. Mean plasma cortisol was positively related to elevated ventricular brain ratio (VBR). No association could be found between dexamethasone suppression test (DST) status and VBR or any other CT parameter. Elevated plasma cortisol levels and increased VBRs were positively correlated with total scores on the Brief Psychiatric Rating Scale, the Global Assessment Scale and the Bech-Rafaelsen Melancholia Scale, but they were not significantly correlated with total score on the Hamilton Anxi…