EFFECTS OF VITAMIN C SUPPLEMENTATION ON THE CHRONIC PHASE OF CHAGAS DISEASE

Introduction: In order to examine the effectiveness of vitamin C (ascorbic acid) in combating the oxidative insult caused by Trypanosoma cruzi during the development of the chronic phase of Chagas disease, Swiss mice were infected intraperitoneally with 5.0 × 104 trypomastigotes of T. cruzi QM1strain. Methods: Mice were given supplements of two different doses of vitamin C for 180 days. Levels of lipid oxidation (as indicated by thiobarbituric acid reactive substances-TBARS), total peroxide, vitamin C, and reduced glutathione were measured in the plasma, TBARS, total peroxide and vitamin C were measured in the myocardium and histopathologic analysis was undertaken in heart, colon and skeletal muscle. Results: Animals that received a dose equivalent to 500 mg of vitamin C daily showed increased production of ROS in plasma and myocardium and a greater degree of inflammation and necrosis in skeletal muscles than those that received a lower dose or no vitamin C whatsoever. Conclusion: Although some research has shown the antioxidant effect of vitamin C, the results showed that animals subject to a 500 mg dose of vitamin C showed greater tissue damage in the chronic phase of Chagas disease, probably due to the paradoxical actions of the substance, which in this pathology, will have acted as a pro-oxidant or pro-inflammatory

Estudo comparativo entre o xenodiagnóstico artificial realizado imediatamente e quatro horas após a coleta de sangue Comparative study between artificial xenodiagnosis performed immediately and four hours after venous punch

Foi realizado xenodiagnóstico artificial, imediatamente e quatro horas após a coleta do sangue, em 63 pacientes, sendo 29 (46%) do sexo masculino e 34 (54%) do sexo feminino. A idade mínima foi 18 anos e a máxima 68, sendo a idade média 39 anos. Onze (17,5%) pacientes apresentaram resultados positivos, sendo 8 (12,7%) no exame imediato e 7 (11,1%) no exame 4 horas após. Os oito pacientes do exame imediato apresentaram 17 pools positivos e os sete do xenodiagnóstico de quatro horas mostraram 11 pools positivos (p =0,34). Quatro pacientes foram positivos exclusivamente no xenodiagnóstico imediato, três somente no exame de 4 horas e quatro positivos em ambos. Os dados autorizam realizar o xenodiagnóstico, até quatro horas após a extração do sangue, sem prejuízo no resultado do exame.<br>Artificial xenodiagnosis was performed immediately after blood venous punch and then four hours later on 63 patients; 29 (46%) were male and 34 (54%) female, mean age 39 years (range 18 to 68 years). Eleven (17.5%) patients presented positive exams, of which eight (12.7%) were from immediate xenodiagnosis and 7 (11.1%) xenodiagnosis fours hours after. Eight patients showed 17 positive pools from immediate xenodiagnosis and 7 patients with xenodiagnosis four hours later showed 11 positive pools (p = 0.34). Four patients were positive only on immediate xenodiagnosis, three only on xenodiagnosis 4 hours after and four were positive in both. The data demonstrate that xenodiagnosis can be performed up to four hours after blood collection without impairing the test results

Caracterização biológica, histopatológica e análise de ácido nucléico de uma cepa Trypanosoma cruzi da região de Marília, SP Biological and histopathological characterization together with nucleic acids analysis of a Trypanosoma cruzi strain from Marília, São Paulo State

Estudou-se o comportamento biológico e histopatológico de uma cepa genuínamente mariliense de Trypanosoma cruzi, isolada em 1997 através de xenodiagnóstico artificial. Vinte e cinco camundongos swiss foram infectados intraperitonealmente, sendo 11 utilizados para a realização da curva parasitêmica e observação da morfologia dos tripomastigotas e 14 foram sacrificados após o 17, 23, 30, 60 e 180 dias pós-infecção e coletados coração, esôfago, fígado, cólon, e músculo esquelético (fragmento da coxa direita) para análise histopatológica. Cultura em meio LIT foi realizada para análise de DNA. Os resultados mostraram predomínio de formas largas, baixa parasitemia com picos médios de 860 tripomastigotas/5mil de sangue ao redor do 20º dia de infecção. Nenhum camundongo morreu na fase aguda da infecção. Exame histopatológico mostrou poucos ninhos de amastigotas em coração, raros em músculo esquelético e cólon com discreto processo inflamatório. Comparada com a cepa Y, que foi isolada de uma paciente da mesma região, notamos diferentes características biológicas e comportamentais, porém a análise de DNA as coloca no mesmo grupo, demonstrando a proximidade dessas cepas.<br>The aim of this report was to study the biological and histopathological behavior of a Trypanosoma cruzi strain, which is found in the region of Marília. The strain was isolated in 1997, by artificial xenodiagnosis. Twenty-five swiss mice were intraperitoneally inoculated. Eleven were used for observation of parasitemia and trypomastigotes morphology and 14 were sacrificed after 17, 23, 30, 60 and 180 days post-infection. Heart, esophagus, liver, colon, and skeletal muscle (fragment of the right thigh) were collected for histopathological study. LIT culture medium was accomplished for DNA analysis. The results showed predominance of broad forms, low parasitemia with mean peaks of 860 trypomastigotes/5mul of blood of the 20th day of infection. No animal died in the acute phase of infection. Histopathological analysis showed several pseudocysts of amastigotes in heart, rare in skeletal muscle and colon with discreet inflammatory process. When Famema strain was compared with Y strain, which was isolated from a patient who lived in the same area, a distinct behaviour and biological characteristics were observed. However, DNA analysis placed them in same group, hence displaying the proximity of these strains