An historical perspective on how advances in microscopic imaging contributed to understanding the Leishmania Spp. and Trypanosoma cruzi host-parasite relationship.

The literature has identified complex aspects of intracellular host-parasite relationships, which require systematic, nonreductionist approaches and spatial/temporal information. Increasing and integrating temporal and spatial dimensions in host cell imaging have contributed to elucidating several conceptual gaps in the biology of intracellular parasites. To access and investigate complex and emergent dynamic events, it is mandatory to follow them in the context of living cells and organs, constructing scientific images with integrated high quality spatiotemporal data. This review discusses examples of how advances in microscopy have challenged established conceptual models of the intracellular life cycles of Leishmania spp. and Trypanosoma cruzi protozoan parasites.

Assessment of cytokine values in serum by RT-PCR in HIV-1 infected individuals with and without highly active anti-retroviral therapy (HAART)

A cross-sectional study was performed on HIV-1 infected individuals with or without antiretroviral treatment (ARV) in the AIDS Day Hospital, Botucatu Medical School, UNESP. Between August 2004 and October 2005, 73 HIV-1 infected individuals were divided into three groups: infected individuals with or without AIDS who had never received ARV (G1 = 15); patients on HAART that had had plasma HIV-1 RNA viral load (VL) equal to or greater than 50 copies/mL (G2 = 27); and patients on HAART with undetectable VL for at least the past six months (G3 = 31). There was also an additional group that comprised blood donors without any sign of the disease and with negative HIV serum tests (G4 = 20), which was the control group. Serum cytokine levels (values in pg/mL) were measured by enzyme-linked immunosorbent assay (ELISA) and specific mRNA expression by reverse transcription polymerase chain reaction (RT-PCR). Both techniques were performed on the four groups for TNF-á, IL-2, INF-ã, IL-4 and IL-10. All patients were submitted to VL determination and CD4+ and CD8+T lymphocyte counts. The analysis of the results revealed a significant comparison among groups for both methods and an association between the latter (> 80% r² > 0.80). There was only one exception, in control individuals for IL-2 by ELISA. The cytokine profiles, in both methods, for the three patient groups, were mature Th-0. The behaviors of IL-2 and INF-ã required emphasis due to consequent expression of dominant Th profile. Both methods showed low IL-2 and high mean values of INF-ã in the three groups. Several authors have recently drawn attention to the substantial apoptosis of infected and non-infected CD4+T cells, mainly during primary infection, persisting only in those with INF-ã phenotype producer and not IL-2. HIV infected individuals submitted to HAART are expected to produce IL-2 in an attempt to present Th-1 profile, but in most cases this did not occur.(AU)