Biomedical subjects

V Hanf

Publications and source records attributed to V Hanf.

39 records · Page 3Linked to original sources

PubMedDate not supplied

Validation and application of a rapid in vitro assay for assessing the estrogenic potency of halogenated phenolic chemicals.

The E-Screen assay serves as an in vitro tool for the detection of estrogenic activity of chemicals and extracts of environmental samples. Based on the induction of proliferation in human estrogen receptor-positive MCF-7 breast cancer cells we could substantially simplify the assay. As one important step of validation we applied the modified assay for testing nine known xenoestrogens. We could confirm the results of other groups assuring the reproducibility of the E-Screen assay. The results provide evidence that the E-Screen assay is suitable for determination of estradiol equivalency factors (EEFs) for environmental estrogens to rank their estrogenic potency relative to the natural estrogen 17 beta-estradiol. Further, we used the optimized proliferation test to screen nine halogenated phenolic compounds for their possible estrogenic potency. Three widely applied chemicals expressed a weak receptor-mediated estrogenic activity: the flame retardant Tetrabromo-Bisphenol-A, the disinfectant 4-chloro-3-methylphenol, and the herbicide educt 4-chloro-2-methylphenol. Their estrogenic potencies were five to six orders of magnitude lower than that of 17 beta-estradiol.

Biological Assay↗

PubMedDate not supplied

Input/output balance of estrogenic active compounds in a major municipal sewage plant in Germany.

24 h samples of untreated and treated wastewater were taken in parallel from a modern municipal sewage plant in southern Germany in March and June 1998. After solid phase extraction, total estrogenic activity was quantitatively measured with a miniaturized E-screen assay and the levels of nine estrogenic phenolic chemicals analyzed by HRGC/LRMS. 17Beta-estradiol equivalent concentrations (EEQ) were 58 and 70 ng/l in the influent and 6 ng/l in the effluent, indicating that the load of estrogenic activity of the wastewater was reduced by about 90% in the sewage plant. Less than 3% of the estrogenic activity was found in the sludge. 4-t-octylphenol, 4-nonylphenol, bisphenol A, 2-hydroxybiphenyl, and 4-chloro-3-methylphenol were detected in the untreated wastewater at levels from 0.13 to 3.6 microg/l. 4-t-octylphenol, 4-nonylphenol, and bisphenol A were present in the effluent at concentrations from 0.16 to 0.36 microg/l, 2-hydroxybiphenyl and 4-chloro-3-methylphenol were not detectable. The contribution of the quantified levels of phenolic xenoestrogens to total estrogenic activity in the sewage was 0.7-4.3%.

Benzhydryl Compounds↗

PubMedDate not supplied

Release of anti-PAF activity from PAF-binding human ovarian cancer cells in culture.

The human ovarian cancer cell line EFO-27 in culture spontaneously produced anti-PAF activity, which eluted from HPLC in the range of synthetic PAF. The activity therefore appears to be due to an antagonistic PAF-analogue. It was detected by a suppressed PAF-induced platelet aggregation in vitro. EFO-27 cells were found to be able to bind synthetic PAF with saturable binding kinetics. This binding led to reduced cell proliferation. The production of anti-PAF activity by EFO-27 cells resembles an autocrine growth regulation in the light of recent findings that other malignant transformed cell lines produce PAF-like activity in vitro if stimulated appropriately.

Cell Division↗