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Neotropical stingrays have stingers at the base of the tail, which are used in self-defense and are covered with an epithelium containing mucous and venom glands. The stingray then sinks its stinger into the victim, causing an extremely painful wound, which can result in tissue necrosis. Medical treatment is based on the use of painkillers, anti-inflammatory drugs and antibiotics, as to date there is no specific antidote for this type of envenomation. Public health authorities should therefore plan measures aimed at the treatment and epidemiologic reporting of stingray envenomation so as to encourage, and provide a basis for, the relevant organs to implement measures to raise environmental awareness, train health professionals to treat victims of envenomation and undertake studies to produce specific serum therapies. [ABSTRACT FROM AUTHOR]

In this study, two mouse hyperimmune sera were produced, one using extract from the stinger of the stingray Potamotrygon motoro and the other using extract from the dorsal region of the same species and their cross-reactivity with extracts from the following species of stingrays from the Amazon basin was investigated using Western blot and dot ELISA: Paratrygon aiereba, Plesiotrygon iwamae, Potamotrygon orbignyi and Potamotrygon schroederi. The results show that the dorsal extract was as immunogenic as the stinger extract and induced high levels of antibodies, which reacted with homologous and heterologous antigens, indicating that both types of extract may be suitable for use in the production of antivenom to treat victims of envenomation by stingrays. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the impacts of metazoan parasites on hematological and biochemical parameters and relative condition factor of tambaqui (Colossoma macropomum ) farmed in northern Brazil. A total of 32 juvenile fish were captured from a commercial fish farm located in the municipality of Rio Preto da Eva, Amazonas state, Brazil. Parasite prevalence was 100% for Anacanthorus spathulatus, Mymarothecium boegeri and Notozothecium janauachensis, 100% for Neoechinorhynchus buttnerae and 53.13% for Dolops geayi. The greatest mean parasite intensity was found in acantocephalans followed by monogeneans and branchiuran crustaceans. A negative correlation was observed between abundance of N. buttnerae and hematocrit percentage, hemoglobin concentration, total thrombocyte count and glucose and between abundance of the monogenean and glucose concentration. Parasitic infections caused damage in tambaqui in terms of the observed hematological parameters that were characterized by hypochromic anemia and thrombocytopenia, which are important parameters to be used in parasitic diagnosis. This study is the first record of the occurrence of Dolops geayi in farmed tambaqui in the Amazon.

Purpose: To morphometrically quantify CD1a+ dentritic cells and DC-SIGN+ dendritic cells in HIV-positive patients with anal squamous intraepithelial neoplasia and to evaluate the effects of HIV infection, antiretroviral therapy and HPV infection on epithelial and subepithelial dendritic cells., Methods: A prospective study was performed to morphometrically analyze the relative volume of the dendritic cells and the relationship between anal intraepithelial neoplasia and cancer in HIV-positive patients from the Tropical Medicine Foundation of Amazonas, Brazil. All patients were submitted to biopsies of anorectal mucosa to perform a classic histopathological and immunohistochemical analysis, employing antibodies against CD1a and DC-SIGN for the morphometric quantification of dendritic cells., Results: HIV-negative patients displayed a CD1a DC density significantly higher than that of HIV-positives patients (3.75 versus 2.54) (p=0.018), and in patients with severe anal intraepithelial neoplasia had correlated between DC CD1a density with levels of CD4 + cells (p: 0.04) as well as the viral load of HIV-1 (p: 0.035). A not significant rise in the median density of CD1a+ DC was observed in the HIV positive/ HAART positive subgroup compared to the HIV positive/ HAART negative subgroup. The CD1a+ DC were also significantly increased in HIV-negative patients with anorectal condyloma (2.33 to 3.53; p=0.05), with an opposite effect in HIV-positive patients., Conclusions: Our data support an enhancement of the synergistic action caused by HIV-HPV co-infection on the anal epithelium, weakening the DC for its major role in immune surveillance. Notoriously in patients with severe anal intraepithelial neoplasia, the density of CD1a+ epithelial dendritic cells was influenced by the viral load of HIV-1. Our study describes for the first time the density of subepithelial DC-SIGN+ dendritic cells in patients with anal severe anal intraepithelial neoplasia and points to the possibility that a specific therapy for HIV induces the recovery of the density of epithelial DC.