Spotlight on CYP4B1.

The mammalian cytochrome P450 monooxygenase CYP4B1 can bioactivate a wide range of xenobiotics, such as its defining/hallmark substrate 4-ipomeanol leading to tissue-specific toxicities. Similar to other members of the CYP4 family, CYP4B1 has the ability to hydroxylate fatty acids and fatty alcohols. Structural insights into the enigmatic role of CYP4B1 with functions in both, xenobiotic and endobiotic metabolism, as well as its unusual heme-binding characteristics are now possible by the recently solved crystal structures of native rabbit CYP4B1 and the p.E310A variant. Importantly, CYP4B1 does not play a major role in hepatic P450-catalyzed phase I drug metabolism due to its predominant extra-hepatic expression, mainly in the lung. In addition, no catalytic activity of human CYP4B1 has been observed owing to a unique substitution of an evolutionary strongly conserved proline 427 to serine. Nevertheless, association of CYP4B1 expression patterns with various cancers and potential roles in cancer development have been reported for the human enzyme. This review will summarize the current status of CYP4B1 research with a spotlight on its roles in the metabolism of endogenous and exogenous compounds, structural properties, and cancer association, as well as its potential application in suicide gene approaches for targeted cancer therapy.

The 'Fish Trader+' model: reducing female fish traders' vulnerability to HIV.

Analysis from research and practice in Africa shows that fishing communities are hardly reached by HIV-related services, education, and business services, partly because of the efforts and costs involved and a lack of good practice in reaching out to these often remote areas. At the same time, fish traders, especially women, travel regularly to remote fishing camps to purchase fish. Although female fish traders may be exposed to HIV, violence and abuse in their interactions and relationships with fishermen, economic necessity keeps them in this trade. Good health among fisherfolk is a basic mainstay of productive and sustainable fisheries, providing food and income to fishing communities and the nation at large. However, these benefits are severely at risk as per-capita fish supplies in several African countries are declining, and fisherfolk are among the populations most vulnerable to HIV and AIDS. Under the regional programme 'Fisheries and HIV/AIDS in Africa: Investing in sustainable solutions,' the WorldFish Center conducted a socioeconomic assessment in the Kafue Flats fishery in Zambia to identify factors related to HIV/AIDS vulnerability among people in the fishing communities, particularly female fish traders. The study identified a variety of factors, hence the 'Fish Trader+' model of intervention was developed to reduce female fish traders' vulnerability to HIV by building on their economic rationale through the formation of savings groups. This article outlines the implementation of the Fish Trader+ model in Zambia and examines its potential to empower female fish traders so as to reduce poverty and vulnerability to HIV in fishing communities.