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Biomedical subjects

H Liesen

Publications and source records attributed to H Liesen.

At least 19 recordsLinked to original sources
PubMed2001

Readiness potential in different states of physical activation and after ingestion of taurine and/or caffeine containing drinks.

To investigate the influence of taurine and caffeine containing drinks and physical stress on the cortical movement-preparation, the readiness potentials or "Bereitschaftspotentiale" (BPs), preceding voluntary self-placed pedalling movements, were examined after different states of exhaustion on an ergometer. 15 (13 right-handed) healthy men, aged between 22-30, participated in a randomised, cross over, double-blind, placebo controlled study. BPs were averaged out of artefact free EEG-segments from more than 90 triggered events, measured at 17 electrodes of the 10:20 system. With increasing effort the BPs were enlarged differently depending on the drink consumed. In placebo trials after exhaustive exercise premovement negative potential curves could be seen even in frontal areas. With caffeine the BPs increased after lower workload, achieving a level, which was reached in the placebo trials only after submaximal physical activation. Furthermore a significant shortening of premovement-brain-potentials in frontal and parietal regions could be seen in the caffeine trials at rest. Taurine admixture seems to inhibit this effects.

Adult↗
PubMed1999

Increased concentrations of interleukin 1-beta in whole blood cultures supernatants after 12 weeks of moderate endurance exercise.

The aim of the study was to investigate whether a regular moderate endurance exercise programme influenced the in vitro cytokine synthesis by stimulated whole blood cultures. To this end, eight healthy subjects exercised moderately by running for 3-5 h a week over a period of 12 weeks, whilst seven other healthy subjects served as the control group. The intensity of the exercise was determined by lactic acid concentrations in the blood which were maintained between 1.8 and 2.5 mmol x l(-1). Over the period of training the running velocity producing the 4 mmol x l(-1) lactic acid threshold increased from 2.86 (SD 0.83) m x s(-1) to 3.06+/-0.79 m x s(-1) (P < or = 0.008). Blood samples were taken at rest before and after the training programme. The following blood parameters were determined: leucocyte count, differential leucocyte count, lymphocyte subpopulations [CD14 positive (+)/CD45+, CD4+/ CD25+, CD8+, CD16+/CD122+]. Whole blood cultures were stimulated with lipopolysaccarides [interleukin (IL)-1 beta and IL-6] and staphylococcal enterotoxin B [IL-2, soluble interleukin 2 receptor (sIL2-R) and interferon (IFN)-gamma]. Cytokine concentrations in the supernatants were measured using an enzyme-linked immunosorbent assay. The white blood cell count, differential leucocyte count, lymphocyte subset distribution and the expression of the CD25 and CD122 antigen on lymphocytes were unchanged by training. After the training programme the IL-1 beta production changed significantly [1496 (SD 264) pg ml(-1) before, compared to 2127 (SD 672) pg ml(-1) after training, P < or = 0.008]. In the control group these parameters remained unchanged. With respect to changes in the values in both groups the syntheses of IL-1 beta (P < or = 0.023) and IL-6 (P < or = 0.021) were significantly higher after regular training. The syntheses of IL-2, sIL-2 and INF-gamma were not significantly influenced. Regular endurance exercise influenced the in vitro production of monocyte derived cytokines, while the effect of exercise on the cytokines synthesized by T-cells appeared to be of lesser importance.

Adult↗
PubMed1999

Increased training load and the beta-adrenergic-receptor system on human lymphocytes.

The influence of increased training on the sympathoadrenergic system was investigated. Moderately trained male subjects (n = 15) increased their training within 10 wk by 60%; eight of the subjects increased their training volume, and seven increased their training intensity. Before and after the training, an exhaustive treadmill exercise was carried out. Acute treadmill exercise increased beta-adrenergic receptor number on mononuclear lymphocytes, isoproternol-stimulated cAMP production, and plasma catecholamine concentration. The increase of receptor number can at least partially be explained by a changed lymphocyte composition at rest and after exercise. After training, the exercise-induced increase of beta-adrenergic receptor number was significantly blunted, and the exercise-induced increase of the isoproternol-stimulated cAMP production per beta-receptor was enhanced. Subjects who experienced increased symptoms of physical discomfort and/or mood changes showed an enhanced cAMP production after training. These findings point to an altered regulation of the receptor and postreceptor mechanisms as an effect of a 10-wk period of hard training.

Adrenergic beta-Agonists↗
PubMed1998

Effect of increasing running velocity on electroencephalogram in a field test.

This study was designed to measure the electroencephalogram (EEG) after exercise with increasing intensity. In a field test with increments in running velocity a 2-min EEG was recorded, together with blood lactate concentration and heart rate, after each stage. An individual protocol was used, with up to six stages of running to ensure comparability of exercise intensity among the subjects, in each of 19 athletes (17 men, 2 women) experienced in leisure-time running. The exercise consisted initially of three running stages of aerobic exercise intensity without blood lactate accumulation followed by stages with an increase of lactate concentration. The protocol of the field test led to a progressive increase in cortical activity directly after the stages without blood lactate accumulation mainly in the delta frequency band, followed by theta and alpha-1 frequency band, and less pronounced in the alpha-2 and in the beta frequency bands. After the stages with an onset and further increase of blood lactate accumulation significant decreases in the beta-2, beta-1 and alpha-1 frequency bands occurred predominantly in temporal (T3, T4, T5, and T6) and occipital (O1, and O2) electrode positions, indicating a stage-by-stage decrease of activity. This decrease may be explained by feed-back from working muscle, via afferents to the cortex from intero- and proprio-receptors and affective processes. This could suggest that through a higher running intensity indicated by an onset of blood lactate accumulation metabolic and mechanical changes led to alterations within the afferent systems influencing the level of cortical activity.

Adult↗
PubMed1997

[Sports and the immune system].

Acute exercise is followed by a mobilization of white blood cells, mainly induced by increased levels of catecholamines and cortisol. NK-cells react the most intensive, they can increase fivefold after intensive exercise. Additionally a weak acute-phase reaction occurs. Most of these changes normalize during twenty-four hours. Parameters of the humoral immune system may be different from the pre-exercise levels up to seventy-two hours. Repeated physical exercise, which is typical for sports, is followed only by small changes of immunologic parameters under conditions of rest. Epidemiological studies give clues that the rate of upper respiratory tract infections in athletes can be described by a j-shaped curve. Moderately active subjects have the lowest rate of infection. For this influence of exercise on health mainly functional changes seem to be important. Especially after excentric exercise immunological cells can be seen in the muscle tissue, which remove destructed tissue. Not very much is known about the role of the immune system in the regeneration of tendons and other bradytrophic tissues.

Cytokines↗
PubMed1997

Moderate and exhaustive endurance exercise influences the interferon-gamma levels in whole-blood culture supernatants.

The aim of this study was to investigate whether moderate or exhaustive endurance exercise influences cytokine levels in whole-blood culture supernatants after stimulation. Therefore, eight healthy subjects were first exposed to moderate exercise on a cycle ergometer for 30 min at 70% of their 4-mmol/l lactic acid (anaerobic) threshold, and 1 week later to exhaustion (for 90 min) at their anaerobic threshold. Blood samples were taken before, 30 min after and 24 h after each exercise bout. The following lymphocyte subpopulations were determined: CD14-positive(+)/CD45+, CD4+, CD8+, and CD16+. Cytokine levels in the supernatants were measured by enzyme-linked immunosorbent assay (ELISA). Production of interleukin (IL)-1beta, IL-6 and tumour necrosis factor (TNF)-alpha were induced with lipopolysaccharides (LPS), and that of IL-2 and interferon (IFN)-gamma with staphylococcal enterotoxin B (SEB) and phytohaemagglutinin (PHA). Cortisol levels were also determined by ELISA. The lymphocyte subset distribution was observed to be unchanged after moderate exercise. Thirty minutes after exhaustive exercise, the CD16+ count was found to be significantly lower, whereas 24 h later the CD4+ count was significantly higher than pre-exercise counts. Moderate exercise influenced the IFN-gamma production (PHA-stimulated), which increased significantly from 974 (391) pg/ml before exercise to 1450 (498) pg/ml 24 h later. Thirty minutes after exhaustive exercise the IFN-gamma level in the supernatants (SEB-stimulated) was significantly decreased (from 14470 (11840) pg/ml before exercise to 6000 (4950) pg/ml after exercise). The IL-1beta and TNF-alpha production per monocyte was also significantly reduced.

Adolescent↗
PubMed1996

Electroencephalogram activity, catecholamines, and lymphocyte subpopulations after resistance exercise and during regeneration.

We examined the effect in ten male sports students of 30-min resistance exercise followed by either 45-min regeneration with massage treatment on a massage bench or supine rest serving as control, on plasma catecholamine concentration, number and distribution of circulating white blood cells and central activity. Resistance exercise increased free plasma adrenaline (A) and noradrenaline (NA), whereas sulphoconjugated catecholamine concentration remained unchanged as determined by high performance liquid chromatography. Exercise induced leucocytosis and lymphocytosis measured by flow cytometry was predominantly manifested by an increase in the number of lymphocytes, monocytes, CD3+ cells, CD8+ cells and CD3- CD16/56+ cells. Computer-aided electroencephalography (EEG) revealed significant increases in absolute EEG band power. The increase was highest in alpha 2 with 51.6 (SD 40.2)% (P < 0.01), followed by beta 1 with 33.3 (SD 21.0)% (P < 0.01), alpha 1 with 31.9 (SD 25.2)% (P < 0.01), beta 2 with 30.8 (SD 26.7)% (P < 0.01), delta with 26.1 (SD 28.7)% (P < 0.05), and theta with 19.8 (SD 16.5)% (P < 0.01). All hormone and immunological variables returned to pre-exercise values 45 min after exercise with no differences between massage and control treatments. However, during regeneration differences in absolute EEG-band power were observed between massage and control treatments. In central (Cz, C3, C4) and fronto-lateral (F3, F4) electrode positions absolute beta 1 spectral power density was significantly lower during massage treatment than during control (Wilcoxon test: P < 0.01). Overall, these data demonstrated that an influence of massage treatment on deactivation characteristics could be observed in EEG measurements but not in plasma catecholamine concentration or blood lymphocytes, indicating that computer-aided topographical EEG may be a useful technique for studying activation and regeneration characteristics.

Adult↗
PubMed1996

The role of the spleen in the leucocytosis of exercise: consequences for physiology and pathophysiology.

Thirteen patients after splenectomy and 13 control subjects participated in the study. The splenectomy was caused in all cases by accidents, none of the participants had had hematological disorders. All of them exercised to exhaustion on a cycle ergometer, beginning with 1 Watt/kg body weight (b.w.) and increasing 0.5 W/kg b.w. every 5 min. Blood samples were taken before and immediately after exercise. The following lymphocyte subsets were determined: CD14+/CD45+, CD3+, CD20+/CD23+, CD4+/CD25+, CD8+, CD16+/CD56+/CD3-. Furthermore, sIL2-R, neopterin and IGG and IGM were measured. The control group exercised more intensively and reached significantly higher levels of lactic acid and catecholamines (adrenaline and noradrenaline). Under conditions of rest all white blood cell counts were higher in the patients group, levels of significance were reached by lymphocyte and B-cell count. B-cells also showed a significantly higher expression of the CD23 antigen. IGM, s-IL2-R and neopterin levels were not significantly different between the two groups. After exercise all cell counts increased significantly, between the two groups no significant differences were seen. We conclude that the pattern of white blood cell mobilization is unchanged after splenectomy, especially natural-killer cell (the subset most sensitive to catecholamines and exercise) mobilization is not impaired. Therefore the importance of the spleen as storage tissue for white blood cells seems to be low with reference to the exercise induced leucocytosis. The elevated expression of the CD23-antigen might indicate a higher activation level of the B-cell system.

Adult↗
PubMed1995

Catecholamines, lymphocyte subsets, and cyclic adenosine monophosphate production in mononuclear cells and CD4+ cells in response to submaximal resistance exercise.

We examined the effect of 30 min of submaximal resistance exercise on free and sulphoconjugated plasma catecholamine concentrations determined by high performance (-pressure) liquid chromatography separation, the distribution of circulating lymphocytes quantified by flow cytometry, and isoproterenol induced cyclic adenosine monophosphate (cAMP) production in mononuclear cells (MNL) and CD4+ cells. Venous blood samples were taken before, immediately after and 45 min after exercise. Resistance exercise increased free plasma adrenaline (A) and noradrenaline (NA) concentrations, whereas sulphoconjugated catecholamine concentrations remained unchanged. Exercise induced leucocytosis and lymphocytosis was predominantly manifested by an increase in the number of total lymphocytes, monocytes, CD3+, CD8+ cells and CD3- CD16/CD56+ cells. Redistribution resulted in a decrease in the CD4+:CD8+ ratio. The total number and distribution of lymphocytes returned to baseline after 45-min rest. An exercise-induced increase in the number of CD3- CD16/CD56+ cells was significantly correlated with the increase in plasma NA (r = 0.66; P = 0.035), indicating a NA dependent process of redistribution. The cAMP-production in MNL was significantly elevated after resistance exercise, when cells were stimulated with 1 mumol.1(-1) isoproterenol [pre-exercise 16.5 (SD 3.3); postexercise 21.6 (SD 9.8); 45 min postexercise 10.7 (SD 2.8)]. The cAMP production in CD4+ cells was not affected by exercise. Therefore, it is discussed whether redistribution is responsible for the exercise induced increase in cAMP production in MNL.

Adult↗
PubMed1994

Leucocytes, lymphocytes, activation parameters and cell adhesion molecules in middle-distance runners under different training conditions.

20 young male track and field runners (400 m-3000 m) with a 4 mmol/l lactic acid threshold of x = 4.97 +/- 0.35 m/s were tested after three different training periods: 1. at the end of a two month endurance training, practised nearly every day; 2. after a period of speed and strength training, which was specific with respect to their discipline, with anaerobic lactic energy production up to 15 mmol/l lactic acid; 3. during the competition period. The blood samples were taken at rest (4 p.m.) and 22 hrs after the last exercise. On the cell surface the antigens CD3+, CD20+CD23+, CD4+HLADR, CD4+CD25+, CD8+CD28+, CD4+CD45RO+, CD16+CD56+, CD54+ and in the blood serum the concentrations of s-IL-2-R, s-ICAM-1 were analysed. 13 students of physical education served as a control group. The main results were: Only at the end of the endurance training period (1) an increase of s-ICAM-1 was found, which may be interpreted as a protective mechanism against infections. Compared with the control group CD20+CD23+ antigen was constantly elevated and during the transition from the training to the competition period the CD4+CD45RO+ subset increased. These results may provide evidence for a connection to a susceptibility to allergic disease and to overtraining. Furthermore, an activation of the specific immune system was indicated by an elevation of the s-IL-2-R and an activation of the monocytic-phagocytic system was shown by increased levels of ICAM-1. The importance of these results for the training process and with regard to susceptibility to infections is discussed.

Adult↗
PubMed1991

Effect of a short maximal physical exercise on coagulation, fibrinolysis, and complement system.

In 11 healthy young subjects, the plasma concentrations of the thrombin-antithrombin III complex, fibrinopeptide A, tissue-plasminogen activator, complement fragments C3a and C4a, and histamine were measured before and after a graded maximal bicycle exercise test. The analyses were carried out 30 min before and immediately before exercise, immediately after exercise, and 30 and 60 min later. All post-exercise values were corrected for plasma volume changes, which were calculated from hematocrit and hemoglobin values. Immediately post-exercise, thrombin-antithrombin III, tissue-plasminogen activator, complement fragments C3a and C4a, and histamine were all significantly elevated (p less than 0.01), compared with the pre-exercise values; 30 and 60 min later the values normalized and significant differences from the pre-exercise values could no longer be measured. Fibrinopeptide A did not change significantly after exercise. The present results provide evidence for a simultaneous activation of coagulation, fibrinolysis, and complement system as well as for a release of histamine after a short maximal exercise.

Adult↗
PubMed1990

Sport activity and personality as elements in preventing cancer and coronary heart disease.

Results are reported for 3 groups of healthy male probands, 318 in each group, matched for age and personality type on the Personality-Stress Questionnaire. One group was actively engaged in sports, one had discontinued former sporting activities, and one group had never taken part in regular sports. Follow-up after 13 yr. showed lowest mortality in those actively engaged in sport, highest mortality in those who had given up sport, with those who had never been engaged in sport intermediate. Prophylactic behaviour therapy was shown to reduce mortality of those who had given up sport to a significant extent but not to affect degree of retinal sclerosis.

Adult↗
PubMed1990

Lymphocyte subsets during the first hours and days after a 2.5 h running test.

After a 2.5 h running test on eight healthy young males the lymphocyte subsets in peripheral blood were analyzed by flow cytometry. The analysis was carried out immediately post-exercise, after a 1 h and 3 h interval as well as a one day, a two day and five day interval. Lymphocyte subpopulations were also measured in five control subjects who did not exercise. Compared with the pre-exercise level the total lymphocyte and T-cell count was decreased 1 h and 3 h after the run and one and two days after exercise (p less than 0.01). The absolute number of monocytes and B-lymphocytes fell significantly (p less than 0.01) on the first and second day after exercise. No consistent change of helper-/suppressor-inducer T-lymphocytes (CD4+) and cytotoxic-suppressor T-cells (CD8+) cells was observed immediately after exercise. One and 3 h later, however, the absolute number of both cell types dropped below pre-exercise values (p less than 0.01). The decrease of the CD8+ cells was more pronounced, causing an increase of the CD4+ to CD8+ ratio (p less than 0.01). Among the CD4+ cells only the Leu 8+ subpopulation showed a relative increase 1 h after the exercise (p less than 0.01) while the Leu 8- population remained unaffected. 1 h and 3 h after the end of the run there was a significant fall of the absolute number and percentage of natural killer cells (Leu 7+) and cytotoxic T-cells (CD8+ Leu 7+) (p less than 0.01). These cells remained low during the first and second day after the exercise (p less than 0.01). In the control subjects the changes of cell counts for all cells examined were much smaller than in the runners. The results indicate that strenuous and prolonged exercise causes a delayed redistribution of lymphocyte subpopulations with a reduction of lymphocytes and particularly of natural killer and cytotoxic cells beginning 1 h after the exercise followed by a reduction of monocytes 24 h later. The percentage increase of CD4+ cells 1 h after the exercise could be explained by an increase of the CD4+ Leu 8+ subpopulation.

Adult↗
PubMed1986

Cardiovascular effects of extreme physical training.

After a short historical remark the development of athlete's heart in childhood is described. Within 2 years significant differences were observed between endurance-trained (swimming) and untrained girls and boys determined by X-ray and echocardiographical examinations. The limits of the physiological size in relation to body weight were not exceeded within 10 years of longitudinal studies. A second point deals with athlete's heart from physiological and clinical viewpoints. The largest healthy heart ever found in our examinations of athletes had a size of 1,700 ml. Sixteen years after stopping the active career it was reduced to 950 ml without a pathological finding. Questionable and pathological cases are described. A third chapter covers the blood supply of internal organs during exercise combined with air or oxygen breathing. In this connection liver, kidneys, heart, lungs, and brain have been investigated. The reduced blood supply of the liver and kidneys during intense exercise on the cycle ergometer was not influenced significantly by inspiration of oxygen. A significant blood volume increase of the lungs was noticed during incremental rates of work. Exercise augmented also blood flow of the brain in relation to the work rate (at 100 W a 27% increase in grey matter flow of the right hemisphere). A fourth chapter deals with new hormonal and neurohormonal aspects related to the cardiovascular system. Beta-endorphines remained unchanged at work rates below the anaerobic threshold but increased significantly during maximal rate of work. The opiate antagonist naloxone abolished the rise in body temperature seen during ergometer exercise. The serotonin antagonist ketanserin lowered the blood pressure and the arterial lactic acid level during an incremental exercise test, similar to the results with the dopamine agonist pergolide. The hormone cardiodilatin is produced in the atrial appendages, and it is a potent substance in the regulation of the cardiovascular system. The adaptive reaction of the sympathetic nerve fibres in the myocard revealed different directions: activation, degeneration, and regeneration. These findings correlated highly significantly with the total amount of catecholamines in the heart muscle.

Adult↗