Biomedical subjects

Ivo Ponocny

Publications and source records attributed to Ivo Ponocny.

4 recordsLinked to original sources

PubMed2005

Endurance exercise training in orthostatic intolerance: a randomized, controlled trial.

Orthostatic intolerance is a syndrome characterized by chronic orthostatic symptoms of light-headedness, fatigue, nausea, orthostatic tachycardia, and aggravated norepinephrine levels while standing. The aim of this study was to assess the protective effect of exercise endurance training on orthostatic symptoms and to examine its usefulness in the treatment of orthostatic intolerance. 2768 military recruits were screened for orthostatic intolerance by questionnaire. Tilt-table testing identified 36 cases of orthostatic intolerance out of the 2768 soldiers. Subsequently, 31 of these subjects with orthostatic intolerance entered a randomized, controlled trial. The patients were allocated randomly to either a "training" (3 months jogging) or a "control" group. The influence of exercise training on orthostatic intolerance was assessed by determination of questionnaire scores and tilt-table testing before and after intervention. After training, only 6 individuals of 16 still had orthostatic intolerance compared with 10 of 11 in the control group. The Fisher exact test showed a highly significant difference in diagnosis between the 2 groups (P=0.008) at the end of the study. Analysis of the questionnaire-score showed significant interaction between time and group (P=0.001). The trained subjects showed an improvement in the average symptom score from 1.79+/-0.4 to 1.04+/-0.4, whereas the control subjects showed no significant change in average symptom score (2.09+/-0.6 and 2.14+/-0.5, respectively). Our data demonstrate that endurance exercise training leads to an improvement of symptoms in the majority of patients with orthostatic intolerance. Therefore, we suggest that endurance training should be considered in the treatment of orthostatic intolerance patients.

Adult↗

PubMed2005

Digit ratio (2D:4D) in homosexual and heterosexual men from Austria.

Neurohormonal theories of sexual orientation emphasize the organizational effects of testosterone on the developing brain. A recent suggestion, that the ratio of the length of the 2nd and 4th digits (2D:4D) is negatively correlated with prenatal testosterone, has led to a number of studies of 2D:4D in homosexual and heterosexual men and women. The results have been mixed. In comparison to heterosexual men, mean 2D:4D in gay men has been reported to be hypermasculinized (lower 2D:4D), hypomasculinized (higher 2D:4D), or to show no significant difference. Here, we report mean 2D:4D in Austrian homosexual and heterosexual men. We found no significant difference between means for homosexual and heterosexual 2D:4D, with values for both falling between 0.96 to 0.97. There are now 6 reports of 2D:4D in heterosexual and homosexual men. Considering Caucasian men, the studies from the United States show low heterosexual mean 2D:4D, and homosexual mean 2D:4D is higher or similar to that of heterosexuals. The European studies show high heterosexual mean 2D:4D, and comparisons with homosexuals reveal the latter to have lower or similar mean 2D:4D to that of heterosexuals. We discuss these results in relation to the suggestion that mean 2D:4D in heterosexual men differs across populations but mean 2D:4D in homosexuals shows less geographical variation (the "uniform mean hypothesis"). It is concluded that more data are required to clarify whether or not there is a 2D:4D effect for sexual orientation in men.

Adult↗

PubMed2005

Influence of an insertion variant in the 5'UTR of the endothelin-1 gene on orthostatic intolerance.

BACKGROUND: Orthostatic intolerance is a multifactorial disease in which the genetic contribution is probably the result of a number of genes acting in combination. Recent work has shown that orthostatic intolerance is influenced by endothelial nitric oxide synthase gene polymorphisms. Since endothelin-1 (ET-1) is one of the most important vasoconstrictor peptides, a frequent adenine insertion polymorphism within the 5'-untranslated region (5'UTR), which is of functional importance for ET-1 expression, could influence orthostatic intolerance. The aim of this study was therefore to ascertain whether this frequent variant of the endothelin-1 gene influences the risk for orthostatic intolerance. METHODS: We studied 257 white patients (120 cases with orthostatic intolerance and 137 controls) for genotyping of the 5'UTR I variant. From this cohort, 111 patients and 99 control subjects underwent a tilt-table test or an upright posture study, including monitoring of blood pressure, heart rate, and plasma catecholamines, in the supine position and during 30 minutes of standing. Genotyping was performed in all participants. Chi tests of independence were used to test for associations between orthostatic intolerance and genotype. In addition, an association of the insertion polymorphism with hemodynamic variables (heart rate, supine and upright blood pressure) was ascertained using one-way analysis of variance. RESULTS: The 5'UTR I variant was significantly less common in patients with orthostatic intolerance (allele frequency 0.36 and 0.28, in controls and cases, respectively). Additionally, we found a significant decrease in the risk of orthostatic intolerance among people who were homozygous for the 5'UTR variant (I/I) compared with the wild-type variant (D/D) (odds ratio, 0.41; 95% confidence interval, 0.17 to 0.97; P = 0.04). No association between the 5'UTR variant and heart rate or blood pressure regardless of diagnosis was found. CONCLUSIONS: Our current results suggest that the hereditary adenine insertion variant in the 5'-UTR of the endothelin-1 gene is protective for orthostatic intolerance. The increased ET-1 protein expression that has been linked with the I variant might be associated with a more efficient hemodynamic response to standing. This is likely one of several common genetic loci that may represent modifiers of orthostatic intolerance phenotypes.

5' Untranslated Regions↗

PubMed2004

[The new German general threshold limit value for dust--pro and contra the adoption in Austria].

Since it has been realised that inhalation of inert dust is one of the important confounding variables for the development of chronic bronchitis, the threshold values for occupational exposure to these dusts needs to be further decreased. The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK-Commission) has set a new threshold (MAK-Value) for inert dusts (4 mg/m3 for inhalable dust, 1.5 mg/m3 for respirable dust) in 1997. This value is much lower than the threshold values currently used world-wide. The aim of the present article is to assess the scientific plausibility of the methodology (databases and statistics) used to set these new German MAK-Values, regarding their adoption in Austria. Although we believe that it is substantial to lower the MAK-Value for inert dust in order to prevent the development of chronic bronchitis as a consequence of occupational exposure to inert dusts, the applied methodology used by the German MAK-Commission in 1997 to set the new MAK-Values does not justify the reduction of the threshold limit value. A carefully designed study to establish an appropriate scientific basis for setting a new threshold value for inert dusts in the workplace should be carried out. Meanwhile, at least the currently internationally applied threshold values should be adopted in Austria.

Air Pollutants, Occupational↗