Frieda Tataruch

Influence of environmental cadmium on testicular proliferation in roe deer

The influence of cadmium on spermatogenesis in roe deer was studied, comparing animals from areas with high (n = 37) and low (n = 23) cadmium exposure. Testes were evaluated during pre-rut (May) and rut (July/August). During these periods the cadmium accumulation (mg/kg kidney) in polluted regions averaged 3.41 and 3.52 in comparison with 1.61 and 1.81 in controls. Cadmium accumulation was positively correlated with testis weight during both seasons. In May the proliferation (units of tissue polypeptid specific antigen/g parenchyma) was lower in animals with higher cadmium (24.02 compared with 78.20; P < 0.01). During the rut, testicular proliferation and spermatozoa/g testis as well as apoptosis showed no significant changes with increased cadmium contamination. The results suggest delayed proliferation during the pre-rutting period in animals with high cadmium exposure, but other indications of effects on the testis were not significant.

Eine Methode zur quantitativen Bestimmung von Retinol im Blutserum mittels HPTLC

ZusammenfassungNach Enteiweißung des Serums mit Methanol wird das Retinol mit Petrolether extrahiert. Auf einer HPTLC-Platte erfolgt im Laufmittel Petrolether: Diethylether (1∶1) die dünnschichtchromatographische Auftrennung. Die quantitative Auswertung erfolgt durch Extinktionsmessung von Probe und Standard mit anschließendem Flächenvergleich der Peaks.SummaryAfter deproteination of the sample with methanol retinol is extracted by petroleum ether. Thin-layer chromatographic separation was performed on a HPTLC-plate in a mixture of petroleum ether and diethylether (1∶1). Quantitative determination was carried out measuring the absorbance of sample and standard spot, followed by calculation of peak areas.

Über die Raney-Nickel-Entschwefelung schwefelhaltiger cyclischer Dipeptide

Raney nickel desulfuration of 3.6-epidithio-l-prolyl-l-proline anhydride andcis-3.6-bis(ethylthio)-l-prolyl-l-proline anhydride yields racemiccis-prolyl-proline anhydride, whereas after the reaction of 3-ethylthio-l-prolyl-l-proline anhydride no inversion of configuration was observed.—During the action of Raney nickel on one asymmetric center the configuration is only retained if steric factors inhibit an inversion.