O cão como modelo experimental para o estudo da história natural da doença de Chagas

Tafuri, Washington Luiz; Lana, Marta de; Chiari, Égler; Caliari, Marcelo Vidigal; Bambirra, Eduardo Alves; Rios-Leite, V.H.

doi:10.1590/s0037-86821988000200010

Cited by 11 publications

(4 citation statements)

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“…Therefore, the possibility of the existence of a reservoir of T. cruzi in host tissues that may act as a source of periodic discharge parasite, would be very important for the study of the pathogenesis of Chagas' disease. Examining this possibility in human chronic Chagas' disease, Teixeira et al an anatomoclinical pattern similar to that observed in human beings (Lana et al, 1992;Lana et al, 1988;Tafuri et al, 1988) and thus it may be considered a Parasite, 1994, 1, 397-400…”

Section: Introductionmentioning

confidence: 77%

Immunocytochemical study of tissue parasitism of dog adrenal glands in experimental chagas' disease

et al. 1994

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Section: Introductionmentioning

confidence: 77%

Immunocytochemical study of tissue parasitism of dog adrenal glands in experimental chagas' disease

et al. 1994

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“…We have demonstrated that acute and chronic phases of Chagas' disease are easily reproduced in the dog, and are very similar to what happens in humans [16,17,31]. Based on this experimental Chagas' disease model, we decided to perform for the first time the immunohistochemical characterisation of caCD8 + and caCD4 + T cells present in inflammatory infiltrate of acute and chronic canine chagasic cardiomyopathy.…”

Section: Introductionmentioning

confidence: 86%

Immunohistochemical studies in acute and chronic canine chagasic cardiomyopathy

et al. 2001

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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. 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 other mechanisms in the genesis of the inflammatory process.

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“…From the anatomopathological point of view the most important fact of this model is that it reproduces the fibrosing chronic chagasic cardiopathy in a manner very similar to that observed in humans. Since it is hard to reproduce that condition in other experimental models, our group has been developing this line of research since 1982 10,19,20,30 . According to our experience, the inflammatory process installed in the myocardium of the dog occurs in systematized and/or diffuse foci, reaching systematically the whole heart, and specially the atria.…”

Section: Introductionmentioning

confidence: 99%

Quantitative analysis of cardiac lesions in chronic canine chagasic cardiomyopathy

Caliari

Machado

Lana

et al. 2002

Rev. Inst. Med. trop. S. Paulo

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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. In the atrial myocardium of dogs infected with Be78 and Be62 cardiac muscle represented 34 and 50%, fibrosis 28 and 32% and adipose tissue 38 and 18%, respectively. The fibrosis observed was both diffuse and focal and mostly intrafascicular, either partially or completely interrupting the path of muscle bundles. Such histological alterations probably contributed to the appearance of electrocardiographic disturbances verified in 10 out 11 dogs which are also common in human chronic chagasic cardiopathy. Fibrosis was the most important microscopic occurrence found since it produces rearrangements of collagen fibers in relation to myocardiocytes which causes changes in anatomical physiognomy and mechanical behavior of the myocardium. These abnormalities can contribute to the appearance of cardiac malfunction, arrythmias and congestive cardiac insufficiency as observed in two of the analyzed dogs. Strain Be78 caused destruction of atrial cardiac muscle higher than that induced by strain Be62.

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O cão como modelo experimental para o estudo da história natural da doença de Chagas

Cited by 11 publications

References 0 publications

Immunocytochemical study of tissue parasitism of dog adrenal glands in experimental chagas' disease

Immunocytochemical study of tissue parasitism of dog adrenal glands in experimental chagas' disease

Immunohistochemical studies in acute and chronic canine chagasic cardiomyopathy

Quantitative analysis of cardiac lesions in chronic canine chagasic cardiomyopathy

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