Molecular phylogeny and species delimitation of the genus Schizodon (Characiformes, Anostomidae).

The genus Schizodon is part of a group of headstanders and relatives (Family Anostomidae) that are widespread and ecologically important fishes in South American rivers. Schizodon includes 15 nominal species but their taxonomy has been challenging due to paucity of decisive characters to diagnose species. We present new molecular data to assess species boundaries or molecular operational taxonomic units (MOTUs), and to infer phylogenetic relationships among species.

Toxic hepatopathy in sheep associated with the ingestion of the legume Tephrosia cinerea.

A disease known as water belly (barriga d'água), characterized by chronic progressive ascites, affects sheep in the semiarid region of northeastern Brazil. The objectives of this investigation were to study the disease and to determine its cause. Only sheep grazing for long periods in pastures where Tephrosia cinerea represents 80% to 100% of the available forage are affected.

Quantitative analysis of cardiac lesions in chronic canine chagasic cardiomyopathy.

Lesions observed in chronic chagasic cardiopathy frequently produce electrocardiographic alterations and affect cardiac function. Through a computerized morphometrical analysis we quantified the areas occupied by cardiac muscle, connective and adipose tissues in the right atrium of dogs experimentally infected with Trypanosoma cruzi. All of the infected dogs showed chronic myocarditis with variable reduction levels of cardiac muscle, fibrosis and adipose tissue replacement.

Immunohistochemical studies in acute and chronic canine chagasic cardiomyopathy.

A major characteristic of Chagas' disease is a myocarditis constituted primarily of mononuclear cells, both during the acute and chronic phases of the disease. Using monoclonal antibodies and image analyses we have quantified canine CD8(+) T cells (caCD8(+) T cells), canine CD4(+) T cells (caCD4(+) T cells) and neutrophils in canine chagasic myocardiopathy induced by two strains isolated from the first human clinical case of Chagas' disease. We also evaluated the influence of tissue parasitism in the genesis of chronic myocarditis through immunohistochemistry.