PEDF 5 inhibition in erectile dysfunction

Dehydroepiandrosterone (DHEA), an adrenal steroid in humans, shows a certain anticarcinogenic effect in rat liver when it is administered simultaneously with strong carcinogens such as N-nitrosomorpholine (NNM). On the other hand, DHEA is an hepatocarcinogen in the rat when administered at high doses for more than 18 months. The hepatocellular tumors arise from amphophilic cell foci and exhibit a well-differentiated pheno-type. Wlien administered subsequent to NNM, DHEA acts as a tumor promoter in rat liver. Preneoplastic lesions of the glycogenotic/basophilic cell lineage induced by NNM are modulated to amphophilic lesions by DHEA. Female animals are more sensitive than males in respect of the carcinogenic and tumor-enhancing effect of DHEA. The higher sensitivity in females may be due to higher blood levels of DHEA andlor different metabolism and elimination of the drug, as compared to males. DHEA markedly induces cytochrome P450IVA, particularly in the liver of male rats. This effect may explain the rapid metabolism and elimination of the substance and the lower carcinogenicity in males. Both preneoplastic amphophilic foci and neoplasms are characterized by a strong proliferation of mitochondria. DHEA also induces peroxisome proliferation and susceptibility to lipid peroxidation in both genders. Furthermore, DHEA causes a reduction in activity and expression of key enzymes of carbohydrate metabolism and of glycogen content in the liver, which may be related to modulation of hepatocarcinogenesis.     

In search of the mechanisms conducive to class differentials in educational choice: a mixed method research

This paper inquires into the mechanisms conducive to social class differentials in educational choice in Flanders (the Northern, Dutch‐speaking part of Belgium) using both quantitative data gathered from parents (N = 1339) and qualitative data gathered during two focus groups with pupils (N = 16). Unlike most of the previous studies, this study takes into consideration all three theoretical perspectives that have driven research on class differentials in educational choice so far, namely cultural reproduction theory, rational action theory and the notion of social capital. Logistic regression analysis shows that self‐selection does also occur in Flanders and that the effect of parental SES cannot be explained by a specific measure of cultural capital centred on knowledge of the educational system, nor by measures of social capital. What emerges most clearly from this study is that pupils' perception of their choice process is powerfully framed by deep‐rooted conceptions about the educational alternatives available to them. Furthermore, children's choices seem to be delimited by parents' opinions of which educational alternatives were acceptable, and which ones not. Our study calls for future research to take the wider context of decision‐making processes more explicitly into account.