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Biomedical subjects

U Tewes

Publications and source records attributed to U Tewes.

11 recordsLinked to original sources
PubMed1999

[Ambulatory long-term rehabilitation of heart patients].

In Germany cardiac rehabilitation contains a comprehensive 3 to 4 week inpatient program. The aim of our study was to perform an outpatient long-term rehabilitation including intense exercise and behavior therapy. In this setting the health benefits could be increased over the first 6 months. Hundred and twelve patients (94 men and 18 women, age 55 +/- 11 years) after myocardial infarction (52%), bypass-surgery (37%), PTCA (23%), and others (15%) were included in the ongoing study. Cholesterol and LDL-cholesterol diminished significantly. HDL-cholesterol was increased significantly after 6 months. The endurance exercise capacity per rate-pressure-product was increased by 46% during the 6 months period. The intake of cholesterol could significantly be diminished from 307 +/- 25 to 258 +/- 19 mg per day. Five of 16 patients became free from smoking. The first results from the long-term outpatient program show that the time of intervention and also the intensity of the medical, exercise and the behavior therapy are important factors for a successful rehabilitation.

Adult↗
PubMed1996

Excavation of caries lesions induces transient decrease of total salivary immunoglobulin A concentration.

Salivary immunoglobulin A (IgA) secreted by salivary glands is the predominant humoral factor of the local immune system in the oral cavity. Epidemiological studies emphasize the importance of salivary IgA in the protection from infections and caries. This study investigated how excavation of caries lesions affects total salivary IgA concentration. Fifteen patients were assigned to two sessions: the first session consisted of the excavation of a caries lesion. Thirty min before, during, directly after, and 30 min after the excavation, patients were asked for saliva samples. One wk later, a control session was performed on the same patients at the same time of the day, consisting of a dental inspection without any drilling. Marked, transient decreases were observed in concentration and secretion rate of total salivary immunoglobulin A during and immediately after caries excavation. Thirty min after caries excavation, immunoglobulin A concentrations returned to baseline. No differences were found between sessions with regard to saliva flow and cortisol concentration. It was concluded that transient decreases of total salivary immunoglobulin A concentrations are induced by excavation of caries lesions.

Adult↗
PubMed1996

Time kinetics of the endocrine response to acute psychological stress.

A first-time parachute jump was chosen as a model to evaluate the endocrine response to acute psychological stress. In 43 inexperienced tandem parachutists, blood was drawn continuously from 2 h before to 1 h after the jump and analyzed at 10-min intervals for plasma concentrations of epinephrine (E), norepinephrine (NE), cortisol, GH, PRL, and TSH. In addition, heart rate was recorded throughout the experiment. There was a significant increase in heart rate and E concentrations during the jump itself. NE, cortisol, GH, PRL, and TSH peaked with a latency of 10-20 min. Apart from cortisol and TSH concentrations, which were still elevated 1 h after the stress event, plasma levels of the other endocrine variables normalized within 1 h following the jump. Statistically significant cross-correlations could be observed between E and NE (r = 0.60, no time lag) and between E and PRL (r = 0.58, 10-min time lag) only. Even in a very homogenous group of subjects and under well-controlled conditions, endocrine responses to acute psychological stress show considerable variations.

Adult↗
PubMed1995

Beta-endorphin, but not substance-P, is increased by acute stress in humans.

The role of neuropeptides in the psychoneuroendocrinological stress response is largely unknown. In this study the effect of acute psychological stress on beta-endorphin and substance-P plasma concentrations was investigated and further the effect of different anxiety levels or control attributions on beta-endorphin or substance-P levels were determined. Blood samples were obtained from 47 inexperienced tandem-parachutists 2 h before, immediately after, and 1 h after a parachute jump and plasma concentrations of beta-endorphin and substance-P were analysed. Anxiety levels and control attributions were assessed by psychometric scales. Whereas substance-P concentrations seemed to be unaffected by the jump stress, there was a transient but significant increase in beta-endorphin levels immediately after jumping. However, subjects higher in state-anxiety at the point of jumping (exit) displayed higher substance-P values at all three time points compared to the "low-anxiety" jumpers. In addition, stress-induced beta-endorphin secretion was dependent on subjective control attributions.

Adult↗
PubMed1993

Changes of natural killer cells during acute psychological stress.

Emotional stress is often followed by increased susceptibility to infections. One major role in the immediate immune response to infection is played by natural killer (NK) cells. This study was designed to establish whether acute psychological stress influences cellular immune functions and to elucidate the role of endocrine parameters as potent mediators of stress induced alterations of the immune system. Forty-five first-time tandem parachutists were examined continuously for their plasma concentrations of cortisol and catecholamines from 120 min before to 60 min after jumping. Lymphocyte subsets, NK activity, and ADCC were determined 2 hr before, immediately after, and 1 hr after jumping. There was a significant increase in sympathetic-adrenal hormones during (adrenaline, noradrenaline) and shortly after jumping (cortisol). Lymphocyte subsets and the functional capacity of NK cells revealed an increase immediately after jumping followed by a decrease significantly below starting values 1 hr later. These changes were significantly correlated to plasma concentrations of noradrenaline. Thus, quick mobilization of NK cells is suggested as one major mechanism for this effective adaptation of the immune system to stress situations.

Acute Disease↗
PubMed1993

Catecholamines induce alterations of distribution and activity of human natural killer (NK) cells.

Catecholamines have been suggested to be responsible for altered cellular immunity after stress. This study was performed to determine the effects of adrenaline and noradrenaline on lymphocyte subpopulations and NK cell functions. Subjects were given a subcutaneous injection of either NaCl, adrenaline (5 micrograms/kg), or noradrenaline (10 micrograms/kg). Catecholamine concentrations, subsets of peripheral blood lymphocytes, NK activity, and antibody-dependent cellular cytotoxicity (ADCC) were analyzed before (baseline) and 5, 15, 30, 60, and 120 min after injection. There were no differences between groups in the distribution of CD2+ and CD8+ lymphocytes over time. However, CD3+ and CD4+ T cells decreased significantly 5 to 60 min after injection of adrenaline. In contrast, NK cell numbers (CD16+, CD56+) increased significantly 5 min after injection of adrenaline and noradrenaline, reached the highest values 15 to 30 min postinjection, and subsequently declined to baseline values 60 (noradrenaline) and 120 (adrenaline) min, respectively, after injection. Similar alterations for NK activity and ADCC were observed after administration of both catecholamines. These data suggest that both sympathetic-adrenal hormones are similarly potent modulators of natural immunity and provide further evidence that catecholamines might be responsible for the observed alterations in immune functions after phases of acute stress.

Adult↗
PubMed1993

Psychophysiological, neuroendocrine and cellular immune reactions under psychological stress.

Emotional stress is often followed by increased susceptibility to infections. Natural killer (NK) cells play a major role in the immediate immune response controlling this susceptibility. In this study on 45 first-time parachutists, it is demonstrated that highly controlled psychological stress increased psychophysiological variables, enhanced the secretion of sympathetic-adrenal hormones and also led to a significant increase of NK cells and their cytotoxic activity followed by a decrease below starting values. This immunological alteration is correlated with the secretion of noradrenaline during the emotional strain. Quick mobilization of these cytotoxic effector cells is suggested as a major mechanism for the effective adaptation of the immune system to stress situations.

Adult↗
PubMed1992

Acute psychological stress increases plasma levels of cortisol, prolactin and TSH.

The effects of acute stress during a parachute jump on hormonal responses were studied in 12 experienced and 11 inexperienced military parachutists. Each subject performed two jumps. Prior to and immediately after each jump blood samples were drawn and analysed for plasma levels of cortisol, prolactin, thyrotropin (TSH), somatotropin (STH), and luteinizing hormone (LH). While there was a significant increase in cortisol, prolactin and TSH levels after both jumps, no alterations could be observed in STH and LH levels. Stress-induced hormonal responses were not affected by jump experience. There was also no association between the endocrine variables and anxiety scores.

Acute Disease↗
PubMed1992

Physiological arousal and perception of bodily state during parachute jumping.

Heart rate and respiration rate were recorded with a portable data recording system before and during a parachute jump in 36 male sport parachutists with differing degrees of experience. The recordings were analyzed at 12 psychologically relevant points in time along with the subjective ratings of physical arousal. Novice parachutists showed a higher degree of self-rated arousal during jumps. However, the two groups displayed nearly parallel curves for heart and respiration rates, differing significantly from each other only in the level of their respective heart rates. Furthermore, experienced jumpers seem to be better informed about their state of physiological arousal during the jump than are novice jumpers. These results do not confirm the proposed anxiety inhibition process, postulated by Epstein (1967).

Adolescent↗