Doença de Chagas: anticorpos IgG, IgM e IgA contra antígenos de amastigota, tripomastigota e epimastigota de T. cruzi em formas agudas e em diferentes formas crônicas da doença

In an attempt to find a better T. cruzi antigen and possible immunological markers for the diagnosis of different clinical forms of Chagas' disease, amastigote and trypomastigote antigens obtained from immunosuppressed mice infected with T. cruzi (Y strain) were assessed in comparison with conventional epimastigote antigens. A total of 506 serum samples from patients with acute and with chronic (indeterminate, cardiac and digestive) forms, from nonchagasic infections, and from healthy individuals were assayed in immunofluorescence (IF) tests, to search for IgG, IgM and IgA antibodies. Amastigote proved to be the most convenient antigen for our purposes, providing higher relative efficiency indexes of 0.946, 0.871 and 0.914 for IgG, IgM and IgA IF tests, respectively. Anti-amastigote antibodies presented higher geometric mean titers (GMT) than anti-trypomastigote and anti-epimastigote. Anti-amastigote IgG antibodies were found in all forms of Chagas' disease, and predominantly IgA antibodies, in chronic digestive and in acute forms, as well as IgM antibodies, in latter forms. Thus, tests with amastigote antigen could be helpful for screening chagasic infections in blood banks. Practical and economical aspects in obtaining amastigotes as here described speak in favour of its use in developing countries, since those from other sources require more complex system of substruction, specialized personnel or equipment.Com o intúito de se aperfeiçoar o diagnóstico sorológico das diferentes formas clínicas da doença de Chagas, foram estudados antígenos de formas amastigota e tripomastigota, obtidas de camundongos imunossuprimidos infectados com cepa Y de T. cruzi, em comparação com o de epimastigota convencionalmente utilizado. Um total de 506 amostras de soro de pacientes chagásicos com formas aguda e crônicas (indeterminada, cardíaca e digestiva), de indivíduos com infecções não relacionadas e de indivíduos sadios foi analisado por reação de imunofluorescência, para detecção de anticorpos IgG, IgM e IgA. O antígeno de amastigota apresentou os mais altos índices de eficiência relativa em testes de IF IgG (0,946), IF IgM (0,871) e IF IgA (0,914), mostrando ser mais conveniente para a finalidade proposta. Anticorpos anti-amastigota apresentaram médias geométricas de títulos mais altas que anti-tripomastigota e anti-epimastigota. Anticorpos IgG anti-amastigota foram encontrados em todas as formas clínicas da doença de Chagas, e anticorpos IgA foram encontrados predominantemente em formas crônicas digestivas e em formas agudas, além de anticorpos IgM nestas últimas formas. Portanto, testes com antígeno amastigota poderiam ser úteis para a triagem de indivíduos chagásicos em bancos de sangue. Aspectos práticos e econômicos na obtenção de amastigotas, conforme descrito neste trabalho favorecem seu uso em países em desenvolvimento, já que o antígeno obtido por meio de outras fontes requer uma infraestrutura mais complexa, equipamentos e pessoal especializados

Neotropical freshwater fisheries : A dataset of occurrence and abundance of freshwater fishes in the Neotropics

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications