Multiple expression control mechanisms of peroxisome proliferator-activated receptors and their target genes.

The peroxisome proliferator-activated receptors (PPAR) alpha, beta/delta and gamma belong to the nuclear hormone receptor superfamily. As ligand-activated receptors, they form a functional transcriptional unit upon heterodimerization with retinoid X receptors (RXRs). PPARs are activated by fatty acids and their derivatives, whereas RXR is activated by 9-cis retinoic acid. This heterodimer binds to peroxisome proliferator response elements (PPRE) residing in target genes and stimulates their expression. Recent reports now indicate that PPARs and RXRs can function independently, in the absence of a hetero-partner, to modulate gene expression. Of importance, these non-canonical mechanisms underscore the impact of both cofactors and DNA on gene expression. Furthermore, these different mechanisms reveal the increasing repertoire of PPAR 'target' genes that now encompasses non-PPREs containing genes. It is also becoming apparent that understanding the regulation of PPAR expression and activity, can itself have a significant influence on how the expression of subgroups of target genes is studied and integrated in current knowledge.

Vectors control importance on leishmaniasis transmission

We reviewed the control of transmission of leishmaniasis regarding chemotherapy, reservoirs elimination, vaccination and insect control through the use of chemical insecticides. We also discussed complementary measures like monitoring traps, impregnated bednets and curtains, repelents, pheromones, biological control, etc. A cost comparison of insecticide interventions through the use of products belonging to the four main chemical groups was also alone, comparing together conventional formulations versus a slow-release insecticide developed by the Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro. We finally did recommendations on the situation that would justify an insecticide intervention to control sandflies.