DEFAR - Departamento de Farmácia
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/530
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Item Heart autonomic innervation during the acute phase of the experimental American trypanosomiasis in the dog.(1998) Machado, Conceição Ribeiro da Silva; Caliari, Marcelo Vidigal; Lana, Marta de; Tafuri, Washington LuizHeart autonomic innervation was studied in dogs during the acute phase of the experimental infection with the Berenice-78 strain of Trypanosoma cruzi. A glyoxylic acid–induced fluorescence method for catecholamines and a thiocholine method for demonstrating acetylcholinesterase activity showed the sympathetic and the parasympathetic nerve fibers, respectively. At day 34 of infection, moderate-to-intense rarefaction of both cholinergic and noradrenergic nerve fibers occurred in the atria of all animals coincident with moderate to intense myocarditis. In the ventricles, sympathetic denervation was clearly present only when the inflammatory processes were moderate to intense. Preliminary results on the chronic phase indicate that normal autonomic innervation coexists with an incipient chronic fibrosing myocarditis.Item Immunohistochemical studies in acute and chronic canine chagasic cardiomyopathy.(2002) Caliari, Marcelo Vidigal; Lana, Marta de; Cajá, Rosângela Aparecida França; Carneiro, Cláudia Martins; Bahia, Maria Terezinha; Santos, César Augusto Bueno dos; Magalhães, Gustavo Albergaria; Sampaio, Ivan Barbosa Machado; Tafuri, Washington LuizA 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. As in human myocarditis, there was a predominance of T lymphocytes in the inflammatory infiltrate in all animals studied. In the dogs inoculated with strain Berenice 78 (Be78) and necropsied during the acute phase of infection, we found 58% caCD8+ and 42% caCD4+ T cells. In chronically infected animals, 53% of T cells were represented by caCD8+ and 47% were caCD4+ T cells. Since normal canine lymphoid organs are constituted by 70–80% caCD4+ T cells and 20–30% caCD8+ T cells our results indicate a higher proliferation of caCD8+ T cells in dogs inoculated with the Be78 strain. In chronic myocarditis induced by the Berenice 62 (Be62) strain, caCD8+ cells constituted 33% of the T cells and 67% were caCD4+ T cells, a proportion similar to that found in normal canine lymphoid organs. Since the Be78 strain induces greater loss of myocardiocytes than strain Be62, we believe that the caCD8+ T cells, among other factors, can be important in the genesis of these lesions. Amastigote nests and immunohistochemically labelled Trypanosoma cruzi antigen were not found in dogs necropsied during the chronic phase. The absence of the parasite in the myocardium suggests the involvement of otherItem Trypanosoma cruzi high infectivity in vitro is related to cardiac lesions during long-term infection in beagle dogs.(2007) Guedes, Paulo Marcos da Matta; Veloso, Vanja Maria; Caliari, Marcelo Vidigal; Carneiro, Cláudia Martins; Souza, Sheler Martins de; Lana, Marta de; Chiari, Egler; Bahia, Maria Terezinha; Galvão, Lúcia Maria da CunhaTrypanosoma cruzi is a hemoflagelate parasite associated with heart dysfunctions causing serious problems in Central and South America. Beagle dogs develop the symptoms of Chagas disease in humans, and could be an important experimental model for better understanding the immunopathogenic mechanisms involved in the chagasic infection. In the present study we investigated the relation among biological factors inherent to the parasite (trypomastigote polymorphism and in vitro infectivity) and immunoglobulin production, inflammation, and fibrosis in the heart of Beagle dogs infected with either T. cruzi Y or Berenice-78 strains. In vitro infectivity of Vero cells as well as the extension of cardiac lesions in infected Beagle was higher for Y strain when compared to Berenice-78 strain. These data suggested that in vitro infectivity assays may correlate with pathogenicity in vivo. In fact, animals infected with Y strain, which shows prevalence of slender forms and high infectivity in vitro, presented cardiomegaly, inflammation, and fibrosis in heart area. Concerning the immunoglobulin production, no statistically significant difference was observed for IgA, IgM or IgG levels among T. cruzi infected animals. However, IgA together IgM levels have shown to be a good marker for the acute phase of Chagas disease.