Trypanosoma cruzi Presenilin-Like Transmembrane Aspartyl Protease: Characterization and Cellular Localization.

The increasing detection of infections of Trypanosoma cruzi, the etiological agent of Chagas disease, in non-endemic regions beyond Latin America has risen to be a major public health issue. With an impact in the millions of people, current treatments rely on antiquated drugs that produce severe side effects and are considered nearly ineffective for the chronic phase. The minimal progress in the development of new drugs highlights the need for advances in basic research on crucial biochemical pathways in T. cruzi to identify new targets. Here, we report on the T. cruzi presenilin-like transmembrane aspartyl enzyme, a protease of the aspartic class in a unique phylogenetic subgroup with T. vivax separate from protozoans. Computational analyses suggest it contains nine transmembrane domains and an active site with the characteristic PALP motif of the A22 family. Multiple linear B-cell epitopes were identified by SPOT-synthesis analysis with Chagasic patient sera. Two were chosen to generate rabbit antisera, whose signal was primarily localized to the flagellar pocket, intracellular vesicles, and endoplasmic reticulum in parasites by whole-cell immunofluorescence. The results suggest that the parasitic presenilin-like enzyme could have a role in the secretory pathway and serve as a target for the generation of new therapeutics specific to the T. cruzi.

DNA extraction of urinary bladder swabs collected from carbonized and decomposing corpses: Possible application in disaster victim identification.

A disaster is an unexpected event causing death or injury to many people. In such events, a large number of casualties may take place, exposing corpses to a harsh environment for days or months. DNA profiling is recognized as one of the primary methods for identifying mass disaster victims, especially when it involves decomposed or fragmented bodies. The objective of this study was to standardize the use of urinary bladder swabs as a source of DNA for the identification of decomposing and carbonized human bodies by Forensic Genetic techniques. Samples' DNA was extracted using both organic and Chelex® resin methods; quantified by qPCR and amplified with PowerPlex® Fusion System (Promega Corporation). The results of this study show that between the two methodologies used for DNA extraction, the organic method presented higher DNA yields in relation to the minimum acceptable for the amplification, while Chelex®, although not having a high yield, still allowed obtaining significant amounts of DNA for amplification. The use of bladder swabs has proven to be a viable source of DNA for human identification, since besides reproducible and reliable results, this type of sample allows a significant reduction in the time and cost required for analysis.

Leishmaniasis treatment--a challenge that remains: a review.

Leishmaniasis is a disease caused by flagellate protozoan Leishmania spp. and represents an emergent illness with high morbidity and mortality in the tropics and subtropics. Since the discovery of the first drugs for Leishmaniasis treatment (i.e., pentavalent antimonials), until the current days, the search for substances with antileishmanial activity, without toxic effects, and able to overcome the emergence of drug resistant strains still remains as the current goal. This article reports the development of new chemotherapies through the rational design of new drugs, the use of products derived from microorganisms and plants, and treatments related to immunity as new alternatives for the chemotherapy of leishmaniasis.