Edmundo Chapadeiro

Contribuição ao estudo da anatomia patológica do megaesôfago chagásico

Estudo anatomopatologico sistematizado foi feito em 56 esofagos de chagasicos cronicos (17 com e 39 sem mega) e em 26 de nao chagasicos com as seguintes finalidades: 1) avaliar as variacoes de calibre e espessura da parede do orgao; 2) analisar qualitativa e quantitativamente o plexo mienterico, na tentativa de avaliar a eventual relacao entre suas lesoes e o aparecimento de megaesofago (ME); 3) estudar as lesoes das musculares procurando verificar sua contribuicao na genese da visceromegalia; 4) pesquisar formas amastigotas do T. cruzi e sua possivel relacao com o processo inflamatorio; 5) identificar as principais alteracoes da mucosa. Confirmou-se que as lesoes mais intensas localizavam-se na muscular propria e no plexo de Auerbach. Na primeira, as principais alteracoes foram miosite e fibrose e nos gânglios mientericos observou-se inflamacao e despopulacao neuronal, maior nos esofagos dos chagasicos com dilatacao em relacao aos sem dilatacao e destes em relacao aos controles. Entretanto, foram vistos esofagos de calibre normal, com intensa denervacao. Conclui-se que parecem ser multiplos os fatores que desencadeiam a esofagopatia, especialmente, o ME. A pesquisa de parasitas em oito esofagos com mega e em oito sem ME foi positiva somente em quatro casos, do primeiro grupo. As lesoes da mucosa e submucosa nao parecem participar do processo.

Anatomia patológica de corações de chagásicos assintomáticos falecidos de modo violento

Com finalidade de melhor conhecimento da forma indeterminada da doenca de Chagas os autores realizaram estudo anatomopatologico sistematizado de trinta coracoes de chagasicos assintomaticos falecidos de modo violento. Demonstram que nos portadores da forma em questao da tripanossomiase cruzi o coracao e acometido por lesoes da mesma natureza, porem de intensidade muito menor do que as observadas em chagasicos cronicos que falecem subitamente ou apos periodo variavel de insuficiencia cardiaca. Baseados em seus achados e em outros dados da literatura, concluem que a infeccao chagasica, sem inflamacao do coracao, se ocorre, e rara. Tecem ainda consideracoes a respeito do significado das lesoes observadas no sistema nervoso autonomo intracardiaco no sistema de conducao e sobre a genese formal da cardite chagasica cronica humana.

Morte súbita em área endêmica da doença de Chagas

A study of the frequency and eliology of sudden death in an area with endemic Chagas disease is reported. The proportion of cases is about the same as elsewhere in this country, where equivalent studies have been done. It is relatively low when compared with that of some other countries. Cardiovascular disease is the most frequent cause of sudden death in most countries. In our study chronic chagasic cardiomyopathy was the major cause of sudden death in people over 15 years of age.

Lesões cardíacas em ratos wistar inoculados com diferentes cepas do Trypanosoma cruzi

Wistar albino rats infected intraperitonially with different inocula of Y, 12SF and Colombian strains of Trypanosoma cruzi developed high parasitemia, which lowered by the end of the 6th week; mortality varied according with the strain and inoculum. Acute carditis like that occurring in the human, was found in all animals killed or dying spontaneously. The surviving rats were sacrificed in the 8th month of infection. They presented active chronic carditis involving especially the myocardium and the intracardiac nervous system. In most of the animals the myocardial inflammation was focal. In approximately 15% it was zonal or difuse with fibrosis associated with muscle cell hypertrophy. Recent and old thrombosis as well as left ventricular apical dilation occurred in about 20% of those animals. The authors confirm that the albino rat is susceptible to chagasic infection and conclude that it represents a useful model for the study of cardiac manifestations of the human disease.

Neuronal counting and parasympathetic dysfunction in the hearts of chronically Trypanosoma cruzi - infected rats

Ten male Wistar rats, chronically infected with Colombian, São Felipe (12SF) and Y strains of Trypanosoma cruzi and ten non-infected control animals were submitted to the bradycardia responsiveness test, an assessment of heart parasympathetic function, after phenylephrine injection. Six chagasic animals showed heart parasympathetic dysfunction characterized by reduction in the index of bradycardia baroreflex responsiveness, as compared with the control group. Microscopic examination of the atrial heart ganglia of chagasic rats showed ganglionitis, but no statistically significant reduction in the number of neurons.

Miocardite chagásica crônica humana: estudo quantitativo dos linfócitos CD4+ e dos CD8+ no exsudato inflamatório

Em cortes histologicos de fragmentos transmurais congelados da parede livre do ventriculo esquerdo, obtidos em necropsias de 10 chagasicos cronicos cardiopatas, foram contados os linfocitos CD4+ e os CD8+ do infiltrado miocardico. As celulas foram marcadas com anticorpos monoclonais, usando-se a tecnica estreptavidina-biotina. Contou-se: l)os linfocitos em todo o exsudato (LTE) e, separadamente, 2) os linfocitos que estavam em contato ou muito proximos das miocelulas (LCMPM). Foram considerados muito proximos aqueles linfocitos cujos nucleos distavam, dasmiocelulas, menos que seus proprios menores diâmetros nucleares. Os linfocitos CD8+foram mais numerosos do que os CD4+, principalmente entre os LCMPM. A relacao CD4/CD8 foi de 0,37 ± 0,20 entre os LTE, mas foi menor quando considerados apenas os LCMPM (0,23 ± 0,11). Dentre os LTE, 34 ± 11% dos CD8+ (contra 24 ± 12% dos CD4+) eram LCMPM. Todas essas diferencas foram estatisticamente significantes. Linfocitos das duas subpopulacoes foram vistos em intima relacao com miocelulas integras ou rotas, e naoforam observados parasitas nos cortes examinados. Estes achados concordam com a ideia de que a lesao dos miocardiocitos na forma cardiaca da doenca de Chagas humana e mediada principalmente por linfocitos T citotoxicos.

Prevalência de megas em necrópsias realizadas no triângulo mineiro no período de 1954 a 1988

One thousand seven hundred and eight chronic chagasic post-mortem examinations studied from a total of4690 autopsies perfomed at our Institution. Two hundred and seventy-three chagasic had megas. Megacolon was the most frequent, followed by megaesophagus. Megacolon associated with megaesophagus was, the third mostcommom finding. Our data are discussed and compared with the literature. Megacolon and megaesophagus were more prevalent in man, as shown by other workers. Higher parasitemia perhaps could explain this finding.

Clinical evolution and morbi-mortality in Chagas disease

The knowledge firstly achieved by CarlosChagas and his colleagues of the Instituto OswaldoCruz, increased with all those acquired to date, al-low us to outline the general scheme (modifiedfrom Dias & Coura 1997) of American trypanoso-miasis natural history (Figure).The knowledge of this natural history makesmore comprehensible the clinical evolution of thedisease, as it will be demonstrated by the reportersof the subject.The Chagas Disease Control Campaign, to-gether with other conditions, has contributed in adecisive way for the significant reduction of thenumber of new cases of the disease. Nevertheless,millions of chagasic individuals still live in ourcountry as well as in other ones of Latin America(Moncayo 1993, Schmunis 1997, Dias & Coura1997). Only this would be enough to justify theconcern with morbidity and mortality due to Ameri-can trypanosomiasis.In addition, the current data about morbidity(analyzed either by the number of individuals whoacquire the disease or by the number of cases inwhich trypanosomiasis has arisen), as well as thecoefficients or rates of mortality allow the under-standing of the severe medicosocial problems con-tinuously generated by the endemic.In the other hand, the prophylatic and thera-peutic measures can explain the significant reduc-tion of morbility and mortality rates in Chagas dis-ease (CD) acute phase in the last years, as it maybe confirmed by comparing Chagas references(1910, 1916) and Chagas and Villela (1922) withthose of Dias (1955), Ferreira (1986) and Dias andCoura (1997).In order to analyse the morbity and mortality inchronical CD, two facts must be initially remem-bered: first, in the chronic phase of American trypa-nosomiasis, the main lesions are situated in the heartand digestive tract; second, the digestive form ofthe disease was characterized only in the 50s(Rezende 1956). This last fact may explain the lackof references on digestive manifestations inchronical CD in the first half of century (Chagas1910, Chagas & Villela 1922), what reflects on com-parative analyses, specially regarding morbidity.In conclusion, it is clear since the beginning ofthe studies on CD that cardiac alterations are themain responsible for morbidity and mortality.Longitudinal studies as those carried out ini-tially in Bambui, State of Minas Gerais, Brazil, fol-lowed by other more recent ones as those ofMacedo (1973) and Dias (1982), allow us to con-clude that only half of the individuals infected withT. cruzi show, in the course of their lives, clinicalmanifestations of CD; among those, only about50% die as a direct or indirect result of the infec-tious course. Mortality is generally high amongchagasic individuals who develop chronic cardi-opathy, mainly when cardiac failure and/or severearrythmias occur. Grossly, it means that 25% ofthe chagasic individuals (which correspond to350,000 people in Brazil) are bound to die becauseof CD. The death official registry service in Brazilindicates that the mortality due to disease is about6,000 deaths/year, prone to decrease in the last de-cade. In Latin America, Moncayo (1993) evalu-ates that 45,000 yearly deaths are due to CD.In the micro-regions of major endemicity, thedeath rate due to CD among adult individuals mayreach 200 per 100,000 inhabitants or more. Theserates are surely underdimensioned since that a sig-nificative number of deaths due to chronicalchagasic cardiopathy are registered as either dueto non defined causes or lack of medical care ordue to other cardiopathies.Data from the World Bank in 1993 show theenormous social burden as a consequence of CD.This burden is significantly greater than that pro-duced by other tropical diseases prevalent in theAmericas. Malaria, schistosomiasis, leishmaniasis,filariasis, oncocercosis and leprosy produce all to-

Análise quantitativa de mastócitos e de granulócitos eosinófilos no miocárdio de ratos wistar cronicamente infectados pelo Trypanosoma cruzi. Contribuição ao conhecimento da fibrose miocárdia

Foi feito o estudo quantitativo de mastocitos e de granulocitos eosinofilos no miocardio de 40 ratos albinos Wistar. Trinta animais encontravam-se nafase tardia da infeccao (8o mes) produzida pelas cepas Sao Felipe, Y e Colombiana do Trypanosoma cruzi, e apresentavam graus variaveis de miocardite cronica; 10 ratos serviram como controles. Miocardite cronica fibrosante (fibrose) ocorreu em 40% dos animais infectados e detectou-se aumento do numero de mastocitos nos animais, chagasicos, o qual se associou a infeccao mas nao a fibrose miocardica. Nao se constatou aumento do numero de eosinofilos.

Sobre a reversão da fibrose hepática esquistossomótica após terapêutica específica. Estudo histológico

Biopsias cirurgicas de figado de portadores da forma hepatesplenica compensada da esquistossomose mansonica, previamente tratados com oxaminiquine (Mansil) e submetidos, posteriormente, a anastomose esplenorrenal, foram estudadas atraves de algumas tecnicas histologicas e imunohistoquimicas. Embora a pesquisa de vermes adultos, de ovos e/ou de granulomas fosse negativa, em todos os especimes examinados, a fibrose portal estava presente.