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Biomedical subjects

P Benes

Publications and source records attributed to P Benes.

At least 55 records · Page 3Linked to original sources
PubMed1982

Steroid hormone receptors in human melanoma.

Human melanomas were investigated for the presence of high-affinity estrogen-, gestagen-, and glucocorticoid-binding proteins. A statistically significant difference was found for mean estrogen receptor (ER) concentrations in melanomas of male versus female origin: female origin 37.6 (0-107) fmol/mg protein, male origin 3.9 (0-8.3) fmol/mg protein. No significant difference between sexes was found for gestragen receptors: 41.5 (0-194) fmol/mg protein for melanomas of female origin versus 99 (0-362) fmol/mg protein for male. Sucrose density gradient analyses revealed specific binding for both receptor types in the 4-5 S region as well as in the 8 S region. The binding affinities were in the same order of magnitude as reported for receptors found in typical steroid target organs. No significant difference in receptor values depending on sex was found for the glucocorticoid receptor: 19.2 (0-43) fmol/mg protein.

Centrifugation, Density Gradient↗
PubMed1981

[Psoriasis and haemodialysis: changes in plasma hormone concentration as a possible therapeutic mechanism (author's transl)].

Free dehydroepiandrosterone (DHEA), DHEA sulphate, testosterone, LH and FSH were measured in plasma from 67 patients with renal disease before and after haemodialysis or haemofiltration. Plasma concentration of the steroid hormones was lower in patients with renal failure than in normal controls, while that of the gonadotrophic hormones was elevated. After haemodialysis or haemofiltration DHEA sulphate level in plasma decreased, free DHEA increased significantly reaching almost the initial value of the control group. There was no change in concentration of the other steroid and gonadotrophic hormones. The likely mechanism is that haemodialysis removes DHEA deficiency in patients with psoriasis which is assumed to be an aetiopathogenetic factor in the disease.

Dehydroepiandrosterone↗
PubMed1981

[Pruritus and bile acids. Determination of sulfalithoglycocholate and glycocholate in suction blister fluid and in serum (author's transl)].

Until now is not clear, whether bile acids play a role in hepatogenic pruritus in patients with cholestasis. A correlation between serum levels and itching does not exist, and therefore an accumulation of bile acids in the skin was made responsible for the etiology of pruritus. However, this could not be proved in skin homogenisates whereas bile acids were found accumulated in the surface lipids of the skin. For this reason, the investigations presented here deal with the determination of glycocholate and sulfalithoglycocholate in suction blister fluid and in serum. The levels of these bile acids were remarkably lower in the fluid of the subepidermally located blisters than in the serum. No significant difference was found between the group of patients with pruritus and cholestasis and the group without cholestasis. These results show that an accumulation of bile acids in the skin does not exist. A correlation between bile acids in the skin and pruritus cannot be proved.

Adult↗
PubMed1981

[Effects of long-term use of mesterolone on different urine metabolites in andrological patients (author's transl)].

We studied whether long-term use of mesterolone (12 weeks and longer) changed the pattern of steroid metabolites in urine from male subjects. We noticed an increase in dehydroepiandrosterone (DHEA) levels from 211-4 +/- 130.5 ug/die to 9943.8 +/- 6564.7 ug/die in the urine of all subjects tested. This increase was significant. After mesterolone administration was discontinued, DHEA levels decreased to their initial value. DHEA levels showed the smallest increase in those subjects having high plasma FSH levels. Perhaps the delta 4 pathway of testosterone synthesis may be preferred in these three subjects. We suppose that mesterolone has a blocking effect on the delta 5 pathway of testosterone synthesis. DHEA from the DHEA-pool can be used for testosterone synthesis and mesterolone seems to block some enzymes in the synthetic pathway. We were not able to detect a decrease in plasma testosterone levels during mesterolone use because of technical problems. Moreover, our patients told us that they felt ill after discontinuing mesterolone use; it may be possible that there is a psychotropic DHEA-effect during mesterolone use.

Adult↗
PubMed1980

[Radioimmunoassay of dehydroepiandrosterone and 5-androsten-3 beta, 17 beta-diol (author's transl)].

A radioimmunological method is described for the determination of dehydroepiandrosterone and 5-androsten-3 beta, 17 beta-diol in plasma. Interfering cross-reactions of the antiserum of 5-androsten-3 beta, 17 beta-diol with testosterone and pregnenolone make it necessary to separate the steroids by thin-layer chromatography before their final determination. With respect to sensitivity, this method is superior to the commonly used photometric and gas-chromatographic analytical procedures. For both steroids the limits of detection are about 170 fmol.

Androstenediol↗
PubMed1980

[Dehydroepiandrosterone deficiency in psoriasis. Hypothesis on the etiopathogenesis of this disease].

In patients with psoriasis in extra- and intracellular deficiency of dehydroepiandrosterone can be demonstrated which leads to an activation of the pentose-phosphate cycle. This dehydroepiandrosterone deficiency is caused by an increased intracellular activity of 17 beta-hydroxysteroid-dehydrogenase. This results in an increased formation of the reduction product androstendiol, which is unable to inhibit the glucose-6-phosphate dehydrogenase, the keye enzyme of the pentose-phosphate cycle. In addition, a decreased penetration of the steroid through the membrane of erythrocytes is demonstrable, by which the intracellular deficiency of dehydroepiandrosterone is still augmented. The effects of this dehydroepiandrosterone deficiency are changes in the humoral regulation of events in growth and proliferation in patients with psoriasis.

17-Hydroxysteroid Dehydrogenases↗
PubMed1979

The absorption of benzoyl peroxide from leg ulcers.

Absorption and clinical efficacy of a preparation containing 20% benzoyl peroxide were studied in 20 patients with leg ulcers of varying etiology. Benzoic acid formed from benzoyl peroxide on penetration through the skin cannot be demonstrated in the plasma until three days after commencing application at the earliest. This indicates a building up of deposits of benzoyl peroxide in the skin. The plasma benzoic acid levels in all patients amounted to less than 5 mumol/l and is therefore toxicologically inoffensive. Clinically, the known therapeutic effects of benzoyl peroxide were confirmed. Neither sensitization nor allergic reactions were found in the 20 patients taking part in this study.

Absorption↗
PubMed1975

Interaction between dehydroepiandrosterone, glucose-6-phosphate dehydrogenase, and cyclic adenosine-3',5'-monophosphate in neoplastic and normal human mammary tissue.

When total DHEA, G-6-PDH activity, and c-AMP were determined in human neoplastic mammary tissue and corresponding normal tissue the G-6-PDH activity in the former tissue greatly exceeded that found in normal tissue. On the other hand, a remarkable decrease of total DHEA and c-AMP could be detected in cancer tissue, hinting at the participation of DHEA in the intracellular regulation of G-6-PDH and c-AMP levels.

Breast↗