Caracterización de cepas Paraguayas de Trypanosoma Cruzi aislada de pacientes agudos de la enfermedad de Chagas / Characterization of paraguayan Trypanosoma Cruzi strains isolated from acute patients of Chagas disease / Annual Reports 1992

Six Trypanosoma Cruzi Paraguayan strains, isolated from accute chagasic patients, were studied by their behaviour in Bald/C mice, metacylogenesis, biometry of metaciclic froms and lectin agglutination. Early, intermediate and late parasitemic peaks were observed and the strains did not show high virulence. Metacyclogenesis capacity was not higher than 50 percent in all cases, and there were no big differences inthe biometry and lectin agglutination assays. Although previous schizodeme analysis of these strains showed rather homogeneous profiles, biological feautures were quite heterogeneous

Actividad tripanocida de productos naturales contra formas sanguineas tripomasrigotes de Trypanosoma Cruzi / Trypanocidal activity of natural products against blood Trypomastigote forms of Trypanosoma cruzi / Annual Reports 1991

Blood trnasfusion is the second most importnatmechanism of transmission of Chagas'disease in both endemic and non-endemic areas. In Latin America, more than 20,000 cases of transmission of the disease, trough blood transfusion, may be occurring. Gentian Violet is currently the only available trypanicidal agent used for treating blood before transfusion. The main disadvantages of this treatment are the time required to allow drug action before transfusion and the coloring of the blood. In vitro trypanocidal effect of plant extracts and that of pure compounds are assessed against trypomastigote blood forms of T. cruzi. The induction of sister chromatid exchange (SCE) in human lypocytes was performed to evaluate mutagenic effects of these compounds. Eight compounds had a high activity against blood forms of T. cruzi at a concentration of 250 mg/ml; namely, daphnandrine, limacine, pheantine, daphnoline and cocsuline. Plumbagin (a naphthoquinone) also showed high trypanicidal activity and has previously been recognized as a leismaniacidal, bactericidal and fungicidal, compound. Daphnoline showed low values for both LC50 (8mg/ml) and LC90 (50mg/ml) and was the only tested compound which did not induce sister chromatid exchange below 10 mg/ml. Therefore, deeper evaluations of these compounds should be considered

Caracterización biológica de un aislado paraguayo de Trupanosoma cruzi / Biological characterization of a paraguayan Trypanosoma cruzi strain / Annual Reports 1991

In order to establish the course of infection, virulence and pathogenicity, a Paraguayan Trypanosoma cruzi strain isolated from a 12 year old patient in 1989, Balb/c mice were inoculated, and the number of parasites were determined by direct parasitemia (micromethod). Pathogenicity were tested by performing tissue disections and direct microscopic observation. The virulence ranged from 9.10 sobre 4 to 6.10 sobre 5 parasites per ml. Peaks of parasitemia were observed between the days 12 and 14, and wide forms were predominant, but not in the peak days. An amastigote nest was found in intestinal muscle and cardiac tissue in only one mouse from the 12 studied