Characterizing functional morphology and trophic niches in a neotropical Characiforms (Actinopterygii: Teleostei) assemblage in middle Munim River basin, Maranhão, Brazil.

Understanding how functionally similar species segregate resources to minimize competition is vital for predicting evolutionary factors and patterns of coexistence. We conducted a study in Mata de Itamacaoca, in the middle Munim River basin, Maranhão, northeastern Brazil, to characterize the functional morphology and trophic niches of five coexisting Characiform species in this area - including a recently described species, and to investigate whether their functional morphology is a key determinant of their trophic niches. Our analysis of functional morphology and diet, employing linear measurements to predict dietary specializations, showed that these species are predominantly generalist insectivores with a significant morphological overlap. This study underscores the influence of species' natural history on their ecological characteristics, contributing to more effective conservation strategies.

Some characteristics of the hyperreactivity to bacterial lipopolysaccharide induced in mice by Trypanosoma cruzi infection.

Mice infected with T. cruzi, Y strain, acquire a high level of susceptibility to the effects of bacterial gram-negative LPS. The LD50 of adult female SW mice to LPS from S. typhosa, decreases from 450 to 2,5 mcg 10-12 days after T. cruzi infection. This hyperreactivity to LPS induced by T. cruzi presents all the characteristics of that found in infection caused by many other agents. During the acute phase of experimental infection with T. cruzi Y strain, mice generally die with a hypovolemic shock very similar to that induced in uninfected animals injected with an adequate dose of bacterial endotoxin. There is evidence for and against the hypothesis that LPS absorbed from the intestinal tract may be involved in the mechanism of death of mice during the acute phase of T. cruzi infection.

Some characteristics of hyperreactivity to bacterial lipopolysaccharide induced in mice by Trypanosoma cruzi infection.

Camundongos infectados com a cepa Y do T.cruzi adquirem elevado grau de reatividade ao LPS de S. typhosa. A LD50 de camundongos SW, adultos, femeas, com peso em torno de 20g, decresce de 450 para 2,5 mcg ao fim de 10-12 dias de infeccao.Esta hiperatividade ao LPS induzida pelo T. cruzi apresenta todas as caracteristicas daquela encontrada nas infeccoes causadas por muitos outros agentes. Durante a fase aguda da infeccao experimental com T. cruzi, cepa Y, os camundongos geralmente morrem com choque hipovolemico muito semelhante ao ocasionado por dose adequada de endotoxina bacteriana. Ha evidencias a favor e contra a hipotese de que os LPS liberados do trato intestinal estejam envolvidos no mecanismos de morte do camundongo durante a fase aguda da infeccao pela cepa Y do T.cruzi

Imunologia da paracoccidiodomicose. / Immunology of paracoccidioidomycosis

Estudos imunologicos foram realizados em 16 pacientes adultos, de ambos os sexos, acometidos de paracoccidioidomicose. Dentre os achados mais importantes figuram os teores elevados de IgG, a baixa do 3o. componente do complemento, a presenca de anticorpos precipitantes e hemaglutinantes contra a paracoccidioidina, a presenca de complexos imunes circulantes, baixos teores de linfocitos T circulantes, teores normais de linfocitos T supressores e hiporreatividade dos linfocitos T a fitohemaglutinina e a paracoccidioidina.A histologia das reacoes cutaneas a paracoccidioidina acusou um aspecto semelhante ao da reacao de Arthus, com o maximo de intensidade do eritema em 24 horas, a presenca de vasculite e a infiltracao predominante por polimorfonucleares