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Biomedical subjects

K Scheuch

Publications and source records attributed to K Scheuch.

At least 19 recordsLinked to original sources
PubMed2004

Sympathetic and parasympathetic activation in heart rate variability in male hypertensive patients under mental stress.

Disturbed sympathetic and also parasympathetic activity of the autonomic nervous system points to pathological alterations in the cardiovascular system. Untreated hypertensive subjects were examined with respect to the question of whether an increase in sympathetic activity necessarily goes along with a reduction in parasympathetic activity, and whether 'delayed' recovery behaviour after mental stress could be an indicator of a disturbed cardiovascular function. In 20 male hypertensive (HT) and 20 normotensive (NT) subjects (control group), heart rate variability (HRV) was compared during rest and under mental stress. The testing procedure consisted of the following phases: habituation, arithmetic tasks without and with interference, recovery. HRV was analysed using the trigonometric regressive spectral analysis (TRS). Proceeding from the total variance (ms2), the weighted averaged frequency (Hz) and the variance parts (ms2) in the frequency bands 'low frequency' (LF-band: 0.04-0.15 Hz) and 'high frequency' (HF-band: 0.15-0.40 Hz) were explored. The variance part modulated by spontaneous breathing within the HF-band was assessed additionally. The variance part in the LF-band under mental stress was significantly increased in the HT group (P<0.01). Activity in the HF-band (without the respiration-dependent part) under mental stress did not differ between both groups, whereas the breathing-modulated part of variance in the HF-band was reduced in the HT subjects. During the recovery period in the HT group, the weighted averaged frequency was still elevated compared to baseline, and the variance part in the LF-band was increased, which may point to delayed recovery behaviour. In addition, by using a discriminant analysis 85% of all subjects were reclassified to the original groups, all HT subjects being assigned 'correctly'. Spectral variance parameters enable early discovery of altered cardiovascular regulation. Respiration influences variance in the HF-band in hypertensive subjects and should therefore be paid attention to. The variance part in the LF-band, weighted averaged frequency and the respiration-modulated variance in the HF-band turned out to be the most valid parameters for the differentiation between NT and HT subjects.

Adult↗
PubMed2001

Functional characterization of the human prion protein promoter in neuronal and endothelial cells.

Human prion diseases such as Creutzfeld-Jakob disease and kuru are of major medical and biological importance because of their fatal course, epidemic potential, and unique pathophysiology. Endogenous expression of the normal cellular prion protein (PrP(C)) is necessary for infection and prion replication. However, knowledge of human PrP(C) gene regulation is rudimentary. We therefore cloned1543 bp of the 5' untranslated and promoter region of the PrP gene. Using transient transfection assays, the full-length promoter and serial deletion mutants subcloned in a luciferase reporter vector were analyzed in neuronal (KELLY) and endothelial (EA.hy926) cell lines, which both express PrP(C) as shown by RT/PCR. Analysis of promoter constructs in KELLY cells indicated two activating regions at -131/-284 and -1303/-1543, relative to the 3'-terminal end of exon 1, and also two repressing elements at -254/-567 and -567/-909 in neuronal cells. In EA.hy926 cells, activating elements were identified at -131/-284 and -284/-567, and one repressing region was localized at -567/-909. In addition, transcriptional start sites were determined by 5'-RACE reaction and RNase protection assay, revealing one major transcriptional start site located at -47 (in KELLY cells), -53 (in human thalamus) and at about -55 (in EA.hy926 cells).

5' Untranslated Regions↗
PubMed2001

Occupational health and safety from communist to capitalist structures.

This article focuses on individual effects of the transformation from communist to capitalist structures in the system of occupational health and safety (OHS). Despite basic similarities among the communist nations the systems of OHS differed immensely. The political changes during transformation additionally contributed to varying opportunities for the development of OHS systems. Changes affecting the living and working conditions are significant and are demonstrated by the development of new work structures and work biographies. This is reflected in changed attitudes to demands and contents of work. No differences, however, were found between the employed and unemployed when asked about these issues. Conclusions for OHS in postcommunist states are drawn.

Capitalism↗
PubMed2001

Occupational medicine--its contribution to protection and promotion of health at work.

This article deals with the special demands on occupational medicine due to the changes of work and of tasks at workplaces. Conclusions for research in occupational medicine are drawn from these processes. They are discussed on the basis on an analysis of literature from the years 1980-1998. Focus of future research in the field of occupational medicine is developed by taking international tendencies, the interdisciplinary setting of occupational medicine, and the close relations between science and practice into consideration.

Health Promotion↗
PubMed2000

Peripheral and brachial blood pressure during standardized occupation-related tests in normotensive and mild hypertensive men and women.

We investigated the usefulness of peripheral blood pressure (BP) measurement in the assessment of strain in occupational physiology. Our hypothesis was that the brachial and peripheral BP reflect physiologically different events under various occupation-related demands in normotensive (NT) and hypertensive (HT) people. A group of 20 female and 20 male subjects with unmedicated mild hypertension that had been diagnosed by ambulatory blood pressure monitoring [awake time systolic/diastolic BP (BPs/BPd) 142.9 (SD 11.3)/86.4 (SD 6.2) mmHg] and 40 NT matched by age and sex [BPs/BPd 120.0 (SD 9.8)/75.6 (SD 5.9) mmHg] attended a laboratory session to undertake mental arithmetic tasks, a fingergrip test and submaximal cycle ergometry. Brachial and peripheral BP as well as heart rate were measured using a sphygmomanometer and an continuously automatic blood pressure measuring device on the finger, respectively. The peripheral BPs was higher than brachial BPs, BPd was similar for peripheral and brachial BP except during cycle ergometry. Associations between the levels of brachial and peripheral BP depended on demands and did not explain more than 42% of the common variance. The highest correlations between the two BP methods were observed during habituation, recovery and mental demands, and weak correlations during cycle ergometry. For peripheral BPs and BPd we found significant correlations in all phases of the test (r = 0.58 to 0.86, P < 0.001), also in ergometry (NT r = 0.62, P < 0.001, HT r = 0.53, P < 0.001), in contrast to the brachial BP. Peripheral BP differentiated the two BP groups (57.5%-72.5% correctly classified) which had been grouped by daily measurement of brachial BP, but brachial BP was superior in this respect with 65.0%-87.5% being correctly classified. These results supported the suggestion that the combined measurement of peripheral and brachial BP provides complementary information regarding physiological changes in NT and HT in different situations.

Adult↗
PubMed2000

Testing of fine motor skills in dental students.

Manual skills form only a part of the capabilities required of future dentists, but they are a very important component, which should be tested. With regard to the dental specialties, the present study tested specialty-independent fine motor skills. No objective, practical solution has been found up to now. 88 dental students and, as a control group, 23 medical students were examined in the longitudinal study. In the course of the analysis, 4 fine motor tests were carried out at the beginning of the 2nd and 6th semesters. The tests comprised the tremometer test, the tremometer test with a mirror, the 2-hand sinusoid test and archery using the Game Gear by SEGA. The test devices facilitate primarily the testing of components of accuracy of movements, indirect working methods, and eye-hand coordination. In the comparison of performances on test day A, the medical students' performance was noticeably better. As testing progressed, results showed stagnation in the performance of the medical students and a significant improvement in the performance of the dental students. That means that the test system can be used for a test over the course of study, but not as an initial test.

Aptitude Tests↗
PubMed1999

The trigonometric regressive spectral analysis--a method for mapping of beat-to-beat recorded cardiovascular parameters on to frequency domain in comparison with Fourier transformation.

Heart rate and peripheral blood pressure as physiological recorded vegetative parameters are very often rhythmically investigated with the Fourier Transformation (FT). In contrast to the original use of FT these parameters are still stochastic with overlaying rhythmical structures. The R-R intervals as independent variables of time are not equidistant. The mathematical structure for the spectral decomposition is critically analysed. The purpose of this article is the presentation of a mathematical method, considering both the statistical and rhythmical features of such time series. On the basis of trigonometric regressions, this method is presented to eliminate the equidistance problems, arising with the usage of FT, by a new mathematical approach. This method computes more precisely the spectral power especially in the VLF range (0.003-0.04 Hz) than FT, because this method of trigonometric regression does not perform a frequency quantization. This method has been used and successfully tested for the analysis of peripheral blood pressure and R-R intervals including an effective reduction of input data.

Adult↗
PubMed1999

Hypertriglyceridaemia in mild hypertension: impact on cardiovascular and hormonal reactivity under different stress tests.

OBJECTIVES: We investigated the significance of hypertriglyceridaemia (HTG) for associated components of the metabolic syndrome and stress reactivity in subjects with mild hypertension. METHODS: Seventeen asymptomatic subjects with mild hypertension assessed by 24-h blood pressure (BP) measurement plus HTG (TG >2.3 mmol/l) were recruited and compared with age- and sex-matched subjects with hypertension alone and healthy controls. Cardiovascular and hormonal stress reactivity were tested in a standardised programme consisting of 6 min mental stress, 3 min finger grip and a submaximal bicycle ergometry. RESULTS: The hypertensive patients with HTG exhibited significantly higher fasting insulin, uric acid and gamma-GT levels and lower HDL-cholesterol. The cardiovascular reactivity was similar in all three tests with respect to brachial and peripheral BP in the groups. Peripheral BP during the tests was found to be higher particularly in subjects with hypertension alone. The correlations between BP parameters were disturbed in hypertensives with HTG. Latter group showed significantly higher dopamine, noradrenaline, as well as ACTH levels and an increased ACTH/cortisol ratio. CONCLUSION: HTG in mild hypertension is indicative for insulin resistance accompanied by a modified vascular reactivity as well as elevated catecholamines and ACTH.

Adult↗
PubMed1998

Effects of different stress settings on cardiovascular parameters and their relationship to daily life blood pressure in normotensives, borderline hypertensives and hypertensives.

The aim of this study was to compare a traditional stress setting, consisting of two mental arithmetic tasks and two Stroop test modifications, and a stress setting of varying task demand and decision latitude according to Karasek's job strain model, with respect to their feasibility to elicit differences in cardiovascular reactivity and recovery in 20 normotensives, 20 borderline hypertensives, and 20 non-medicated hypertensives, carefully selected by means of World Health Organization criteria. In addition, the relationship between laboratory and everyday blood pressure was investigated. All subjects were tested under both stress settings in counterbalanced order. Blood pressure was recorded both intermittently from the brachial artery (Riva-Rocci) and continuously from the finger (Finapres). Heart rate and electrodermal activity were continuously measured as well. Furthermore, daily life blood pressure recorded by means of 24 h ambulatory monitoring during a normal working day served as criterion for the re-classification of the blood pressure groups by means of discriminant analysis using physiological recordings from baseline, test phases and rest phases. The groups did not show significant differences in their reactivity to the various mental stressors including the Karasek-model oriented ones but marked differences in their behaviour occurred during the 10 min of recovery following each stress setting. Both systolic and diastolic blood pressure in hypertensives failed to recover during this period. The results also showed the superiority of the Finapres method with respect to reflecting the dynamics of physiological recovery processes. None of the stress settings showed an advantage in predicting blood pressure in daily life. In general, the results question the validity of mental laboratory stressors for the prediction of cardiovascular changes in daily life but point to a possible role of recovery processes after stress in the development of essential hypertension.

Adult↗
PubMed1996

Leukocyte responsiveness to substances that activate the respiratory burst is not altered in borderline and essential hypertension.

Activated leukocytes have been implicated in the pathogenesis of hypertension and its complications. The present study investigated the activity stage of leukocytes for production of reactive oxygen species (ROS) in 17 normotensive controls and subjects with borderline (n = 17) or essential hypertension (n = 17) using different biological materials (whole blood and isolated polymorphonuclear leukocytes (PMNLs)), stimuli (zymosan and formyl-methionyl-leucyl-phenylalanine (FMLP)) and ROS detection assays (chemiluminescence, hydrogen peroxide and superoxide anion determination). Neither the capacity for extracellular generation of oxygen metabolites nor the production of ROS with an intracellular origin were significantly different in isolated PMNLs between controls and hypertensive subjects. There were no significant differences in the luminol-amplified zymosan- or FMLP-stimulated whole blood chemiluminescence response. In addition, the leukocyte count did not differ between the groups. The results suggest that circulating leukocytes of controls and hypertensives existed in a resting state in our experimental conditions. We did not find any evidence of enhanced basal leukocyte free radical activity in patients with mild or severe hypertension.

Adult↗
PubMed1993

[Prevalence of symptoms in selected diagnostic groups in teachers].

In the context of occupational medical screening, teachers in the age groups up to, and older than, 45, were examined under a standardized medical programme in 1987 (22,240) and in 1988 (25,934). The relative risk within these groups for various illnesses was compared with data from investigations with other workers also examined in the former German Democratic Republic (over 400,000 yearly). As was the case for other occupational groups, the most frequently occurring symptoms were related to the musculoskeletal and cardiovascular systems. Teachers in both age categories showed a higher risk for illnesses of the nervous system, especially psychic disturbances and neurosis, and kidney and bladder diseases; male teachers showed a higher risk for cardiovascular diseases, and female teachers for diseases of the respiratory system. Elevated relative risks were already apparent in the group up to 45 years; for diseases of the nervous system the risk increased even further in subjects in the older age category. The proportion of persons overweight was, among female teachers, markedly smaller than in other groups.

Adult↗
PubMed1993

[Promoting competence in training courses--"health sciences--public health" at the Dresden Medical Academy].

The postgraduate study "Gesundheitswissenschaften--Public Health" of the Medical Academy of Dresden was started at 1991. Reasons are given for the necessity of Public-Health education in the new Laender of the FRG. Basing on the previous experiences some examples are given for the development of public-health competence for students, teachers and a Medical Faculty. Some difficulties in the job market are discussed.

Clinical Competence↗
PubMed1990

[Significance of situational increase in blood pressure as a result of psychoneural stress relative to recovery for long-term stress sequelae].

3 regulation types of blood pressure under psychic load (examinations) depending on the level of blood pressure during examination and the recovery time were investigated with a complex programme before and after an examination period of 3 months. Only in the group with elevated blood pressure and delayed recovery time we have found after the period of 14 examinations and increased risk of fat metabolism (HDL-cholesterol, LDL/HDL), an elevated diastolic blood pressure and a decreased physical performance.

Adult↗
PubMed1990

[Behavior of biochemical stress reactions in real professional performance of teachers in relation to age and occupational ability].

In order to investigate the strain of teachers as persons with chiefly psychic load several hormonal parameters (ACTH, HGH, cortisol, catecholamines) and trace elements (zinc, copper) were measured at a teaching day as well as at a teaching-free day. The different influences of age and reduced professional performance on the concentrations of the biochemical parameters were shown. It seems that the variation of release of catecholamines is the most important parameter for the diagnostic of strain in such professional load.

Adult↗
PubMed1990

[Patterns of psychosocial stress factors and health criteria].

Derived from the principles of capacity and of need's realization in the load-strain-coping-concept a 5-cluster result with parameters of subjective health and psychosocial factors is demonstrated. These patterns reflect the different connections between health and the person-environment interaction. A high subjective professional load is connected with a poor health state only in a low professional performance and/or deficits of need's realization.

Adaptation, Psychological↗
PubMed1990

[Occupational medicine outpatient management of workers with responsibilities involving great psychological stress].

Some selected results from regular medical occupational fitness evaluations, the statistic of unfitness for work, the disablement of teachers and the occupational referred mortality were demonstrated in special consideration of workers with particular psychic load. From it conclusions were drawn for the development of methods for occupational medical fitness examinations and check ups, prophylactic and therapeutic programmes. The necessarity of scientific dealing with this problems was emphasized.

Adult↗
PubMed1989

[Occupational disability among teachers and its relation to subjective health status and professional performance].

The aim of this study was to examine the relationship between absenteeism and functional health state, action competence, realization of professional goals and essential needs as well as subjective strain in job and family and type A behaviour pattern. The results of discriminant analyses from a sample of 774 teachers (group 1; no sickness leave days, group 2: sickness leave days greater than 28) are discussed.

Absenteeism↗