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E Chapadeiro

Publications and source records attributed to E Chapadeiro.

At least 19 recordsLinked to original sources
PubMed2001

Trypanosoma cruzi: characterization of reinfection and search for tissue tropism in hamsters (Mesocricetus auratus).

Tissue tropism, the role of reinfection in the development of Chagas' disease, and the selection of subpopulations of Trypanosoma cruzi were evaluated in hamsters inoculated with the VIC strain of T. cruzi. Adult allogeneic male hamsters were inoculated once or reinoculated by the intraperitoneal route up to four times with 2000 blood trypomastigotes. Animals were studied by blood culture, histopathology, immunohistochemistry, and molecular techniques (PCR and low-stringency single specific primer-PCR). Homogeneity of the T. cruzi population observed in different tissues suggests that selective tropism of the VIC strain extends only to various muscle tissues in hamsters and that reinfection is not a factor in the development of the inflammatory processes, although it may aggravate it, possibly due to an increase in tissue parasitism, which might induce autoimmune mechanisms. Reinfection did not induce selection of subpopulations in the tissue or in the blood.

Animals↗
PubMed2001

Neuron count reevaluation in the myenteric plexus of chagasic megacolon after morphometric neuron analysis.

This study was made with the objective of reevaluating the colon denervation in chronic Chagas' disease. The diameters of neuron perikaryons of the myenteric plexus were measured on paraffin sections in a ring from the sigmoid in Chagas' disease patients, 17 with and 10 without megacolon and in 10 non-chagasic controls. All neurons were counted in ten en-echelon sections. Neuron hypertrophy only occurred in the group with megacolon, and the average increase in diameter was 69.3%. This could generate an error factor in the neuron count by increasing the probability of neurons being seen in a greater number of histological sections. The original result of the neuron count gave medians of 1264, 1961, and 2665 in the groups of chagasic patients with megacolon, without megacolon, and in the control, respectively. The denervation was greater than 55% in only seven megacolon cases (41.2%). After applying a correction factor, the median in the group with megacolon was 746, and the denervation was greater than 55% in 13 cases (76.5%). This occurrence demonstrates the need to apply a correction factor when the neuron count in chagasic megacolon is being evaluated and in the other pathologies where neuron hypertrophy may be found.

Adult↗
PubMed1998

Chagasic meningoencephalitis in the immunodeficient.

Based on their own experience and on the literature, the authors compare the brain pathology due to HIV+ associated Trypanosoma cruzi reactivated infection to that described for the natural history of the Chagas' disease (CD). The peculiar focal necrotizing chagasic meningoencephalitis (MECNF) which appears only in immunedeficient chagasics, especially when the deficiency is due HIV is a safe criterion for reactivation of CD. MECNF morphologic findings are unlike to those found either for some cases of acute phase CD or for chronic nervous form of CD.

AIDS-Related Opportunistic Infections↗
PubMed1995

Second recorded case of human infection by Echinococcus oligarthrus.

The paper reviews a previously published case of hydatid disease in the human heart of a Brazilian person who died of tetanus. Based on present knowledge about the distinguishing characteristics of Echinococcus granulosus, E. vogeli, and E. oligarthrus, it was recognized that the infection was due to E. oligarthrus, mainly based the morphologic features of the hooklets of the protoscolex. This is the second human infection due to E. oligarthrus and the first showing wall features of cysts. Therefore, some human infections of polycystic hydatid disease observed outside the range of the bush dog, the only definitive host of E. vogeli (Panama to Northern Argentina), may be due to E. oligarthrus rather than to E. vogeli.

Aged↗
PubMed1995

[Coronary arteriosclerosis and myocardial infarction in chronic Chagas' disease].

PURPOSE: To evaluate both the frequency of myocardial infarction and coronary atherosclerosis as well as the pathology of the later in necropsied chronic chagasic individuals. METHODS: Systematized gross and light microscopy were performed in hearts, especially at the three main coronary arteries. Eighty-nine hearts were studied, 35 chronic chagasics and 54 nonchagasics, all from males. Statistical tests were used for frequency analysis. RESULTS: Myocardial infarction occurred in 8.6% chagasics and in 7.4% nonchagasics. Coronary atherosclerosis was detected in 71.4% of chagasics and in 74.1% of nonchagasics. Its morphology was similar for both groups and indistinguishable from the classical descriptions of atherosclerosis. There were no cases showing lesions compatible with accelerated coronary atherosclerosis. CONCLUSION: The frequency of myocardial infarction and coronary atherosclerosis was the same for both chagasics and nonchagasic individuals. The morphological findings for the studied arteriopathy were identical for the two considered groups. However, it seems that the frequency of myocardial infarction is higher in chagasics with normal coronary arteries (with or without minimal atherosclerotic lesions), as compared with nonchagasics.

Adult↗
PubMed1993

Expression of major histocompatibility complex antigens and adhesion molecules in hearts of patients with chronic Chagas' disease.

We have previously reported that heart lesions in patients with chronic cardiac Chagas' disease are composed predominantly of granzyme A+, cytolytic CD8+ T lymphocytes. We now pursue this study in the immunopathology of chronic chagasic cardiomyopathy by investigation of the expression of HLA antigens, and adhesion molecules in the hearts of seven chagasic patients with cardiac disease, two asymptomatic chagasic patients, and seven normal controls. Comparative immunohistochemical analyses show that HLA-ABC antigen expression is enhanced on the myocardial cells of chagasic patients with chronic cardiomyopathy, suggesting a possible role for these cells as targets for the CD8+ cytolytic lymphocytes dominant in these lesions. The HLA-DR antigens are not observed on myocardial cells, but are consistently upregulated on the endothelial cells in the hearts of patients with chronic chagasic cardiomyopathy. Intercellular adhesion molecule is expressed by endothelial cells of both chagasic and nonchagasic individuals, but E-selectin was detected only on vessels of hearts from chagasic patients who had chronic cardiomyopathy. Most of the lymphocytes in these lesions express lymphocyte function antigen-1 (LFA-1), CD44, and very late antigen-4, and a few display weak expression of LFA-3. We propose that the expression of these adhesion molecules and major histocompatibility complex antigens by endothelial cells, myocardial cells, and lymphoid cells in these lesions contribute to the pathogenesis of chronic chagasic cardiomyopathy.

Adult↗
PubMed1992

Cardiac autonomic dysfunction and neuroganglionitis in a rat model of chronic Chagas' disease.

OBJECTIVE: The aim was to evaluate whether the cardiac parasympathetic function in a rat model of chronic Chagas' disease is impaired as in the human disease, and to correlate the functional state to histopathology of the intrinsic autonomic innervation of heart. METHODS: 70 male Wistar rats 8 months infected with strains Y (n = 22), São Felipe (n = 18), and Colombia (n = 30) of Trypanosoma cruzi, were compared with 20 age and sex matched non-infected controls. Baroreflex bradycardia was quantified after multiple bolus injections of phenylephrine (3 to 12 micrograms). For each rat studied a mean was obtained of the absolute and relative (delta %) ratio (index) between the maximum heart rate decrease and the maximum systolic blood pressure increase. RESULTS: For the relative index the means were smaller (p less than 0.05) in the Y [-0.52(SD 0.19)%], São Felipe [-0.45(0.28)%], and Colombia [-0.53(0.21%)] subgroups, as well as in the pooled chagasic group [-0.51(0.22)%], than in the control group [-0.64(0.13)%]. In 32% (7/22), 33% (6/18), and 20% (6/30) of rats infected with Y, São Felipe, and Colombia strains, respectively, and in 27% (19/70) of the pooled group rats, the index exceeded the control group mean by -2 SD. After atropinisation, a similar pronounced reduction (p less than 0.01) in the index was observed in all groups [-84(28)% to -95(17)%]; however, rats with depressed bradycardia showed a smaller (p less than 0.05) reduction in the relative index than control rats, at -70(34) v -92(16%). Inflammatory and degenerative lesions of the intrinsic cardiac innervation were observed in 87% of the rats with autonomic dysfunction. Rats with the lesions showed a mean relative index that was smaller than those without lesions, at -0.44(0.23) v -0.64(0.20)% (p less than 0.01), and also smaller than in the controls. CONCLUSIONS: Cardiac autonomic dysfunction expressed by reduced baroreflex bradycardia was detected in rats chronically infected with T cruzi, as in human Chagas' disease. The disturbance, shown for the first time in an animal model of chagasic infection, resulted primarily from impaired efferent parasympathetic activity caused by intrinsic neuroganglionar lesions.

Animals↗
PubMed1978

Post-mortem diagnosis of chronic Chagas's disease comparative evaluation of three serological tests on pericardial fluid.

In an attempt to improve the post-mortem diagnosis of Chagas's disease the authors performed haemagglutination tests (HAT), fluorescent Trypanosoma cruzi antibody tests (FAT), and complement fixation tests (CFT) on the pericardial fluid obtained at autopsy of 50 individuals with Chagas's heart disease, and 93 patients in whom this disease was not thought to be present. The results demonstrate that all three tests are efficient for the post-mortem diagnosis of Chagas's disease but suggest that their combined use would detect more cases than would one isolated reaction only.

Antibodies↗