Radiological study of megacolon in trypanosoma cruzi infected rats / Estudo radiológico de megacólon em ratos infectados por trypanosoma cruzi

ABSTRACT Background: Researches on Chagas disease still use several animals and rats, due to size and susceptibility were preferred by many authors. Aim: To develop an experimental model of megacolon in rats inoculated with the strain Y of Trypanosoma cruzi. Methods: Thirty male Wistar rats were distributed in three groups inoculated with different inoculants: Group A: 600000, Group B: 1000000 and Group C: 1500000 blood trypomastigotes of T. cruzi. Animals were sedated intramuscularly at zero inoculation time (T0) and 60 days after inoculation (T60), to perform the barium enema in order to evaluate the dilatation of the different segments of colon in a comparative study of the measurements obtained, using a digital caliper. Evidence of infection was performed by blood smear collected from the animal's tail 18 days after inoculation with observation of blood forms. Results: Comparing the intestinal diameter of the inoculated animals with 60,0000 trypomastigotes in the T0 of infection with T60 days after the inoculation, significant dilatation was observed between the proximal, medial and distal segments (p<0.01), indicating the establishment of the megacolon model. In addition, comparing intestinal diameter between the different segments, with in the T0 of infection and the T60 after inoculation, significant alterations were observed (p<0.05). Conclusion: The proposed model was possible for in vivo studies of alterations due to infection by T. cruzi and functional alterations of the colon. In addition, the changes manifested in the colon are not directly proportional to the size of the inoculum, but to the time of infection that the animals were submitted, since the animals inoculated with 60,0000 blood forms were the ones which presented the most significant alterations.

RESUMO Racional: Pesquisas para doença de Chagas ainda utilizam diversos animais e o rato por seu tamanho e sua suscetibilidade foi o preferido por muitos pesquisadores. Objetivo: Desenvolver um modelo experimental de megacólon em ratos inoculados com a cepa Y de Trypanosoma cruzi. Métodos: Utilizou-se 30 ratos, machos, distribuídos em três grupos inoculados com diferentes inóculos: Grupo A: 600000, Grupo B: 1000000 e Grupo C: 1500000 tripomastigotas sanguíneos da cepa Y de T. cruzi. Os animais foram sedados via intramuscular no tempo zero de inoculação (T0) e aos 60 dias após a inoculação (T60) para realização de enema opaco para avaliação da dilatação dos diferentes segmentos do cólon em estudo comparativo das medidas obtidas, com o auxílio de um paquímetro digital. A comprovação da infecção foi realizada com esfregaço de sangue coletado a partir da cauda do animal 18 dias após a inoculação com observação das formas sanguíneas. Resultados: Ao comparar o diâmetro intestinal dos animais inoculados com 60.0000 formas tripomastigotas no T0 de infecção com T60 dias após a inoculação, observou-se dilatação significativa entre os segmentos proximal, medial e distal (p<0,01), indicando o estabelecimento do modelo de megacólon. Além disso, ao comparar o diâmetro intestinal entre os diferentes segmentos, dentro do T0 de infecção e do T60 após a inoculação, observou-se alterações significantes (p<0,05). Conclusões: O modelo proposto mostrou-se factível para estudos in vivo das alterações decorrentes da infecção pelo T. cruzi e alterações funcionais do cólon. Além disso, as alterações manifestadas no cólon não são diretamente proporcionais ao tamanho do inóculo, mas sim ao tempo de infecção que os animais foram submetidos, visto que os inoculados com 600000 formas sanguíneas foram as que mais apresentaram alterações significantes.

Myenteric plexus is differentially affected by infection with distinct Trypanosoma cruzi strains in Beagle dogs

Chagasic megaoesophagus and megacolon are characterised by motor abnormalities related to enteric nervous system lesions and their development seems to be related to geographic distribution of distinct Trypanosoma cruzi subpopulations. Beagle dogs were infected with Y or Berenice-78 (Be-78) T. cruzi strains and necropsied during the acute or chronic phase of experimental disease for post mortem histopathological evaluation of the oesophagus and colon. Both strains infected the oesophagus and colon and caused an inflammatory response during the acute phase. In the chronic phase, inflammatory process was observed exclusively in the Be-78 infected animals, possibly due to a parasitism persistent only in this group. Myenteric denervation occurred during the acute phase of infection for both strains, but persisted chronically only in Be-78 infected animals. Glial cell involvement occurred earlier in animals infected with the Y strain, while animals infected with the Be-78 strain showed reduced glial fibrillary acidic protein immunoreactive area of enteric glial cells in the chronic phase. These results suggest that although both strains cause lesions in the digestive tract, the Y strain is associated with early control of the lesion, while the Be-78 strain results in progressive gut lesions in this model.

Length and caliber of the rectosigmoid colon among patients with Chagas disease and controls from areas at different altitudes

Introduction In this study, we investigated radiological changes in the sigmoid colon in chagasic patients by comparing their colon lengths and caliber with those of non-chagasic living in the same region and non-chagasic living at high altitudes. Methods A total of 317 individuals were evaluated using clinical, serological and radiological methods and divided into three groups: 1) one hundred and nine non-chagasic individuals from Uberaba, Brazil; 2) sixty-one non-chagasic from Puno, Peru; 3) one hundred forty-seven chagasics examined in Uberaba, being 62 without megacolon (3A), 72 with megacolon (3B) and 13 with doubtful diagnosis of megacolon (3C). Results In group 2, the sigmoid colon had a significantly larger caliber (p=0.001) and the rectosigmoid colon was longer (p<0.001) than group 1. In subgroup 3A, the sigmoid colon (p<0.001) and rectum (p<0.001) had a significantly larger caliber and the rectosigmoid was longer (p<0.001) than that of the non-chagasic individuals. In subgroup 3B, the rectosigmoid was longer in all patients, and the caliber of the sigmoid was significantly larger than that of subjects in subgroups 3A and 3C (p<0.001). Conclusions Morphometric analysis confirms that Chagas disease may increase the caliber and length of the rectosigmoid. Our results suggest that altitude, ethnicity and diet may have influenced the size and length of the rectosigmoid of andean patients. .

Estudo radiológico do megacólon em área endêmica de doença de Chagas / Radiological study on megacolon cases in an endemic area for Chagas disease

INTRODUÇÃO: Foi realizado estudo radiológico do cólon em pacientes de zona endêmica da doença de Chagas usando-se a técnica do enema opaco simplificado de Ximenes e cols. MÉTODOS: Participaram 291 pacientes, com idade media de 48,8 (±12,5) anos, sendo 222 soropositivos para doença de Chagas. Fizeram radiografias na posição ântero-posterior, póstero-anterior e perfil lateral esquerdo, que foram analisadas por inspeção visual e medida do maior diâmetro em centímetros do reto e sigmoide. RESULTADOS: À inspeção visual, foi possível diagnosticar megacólon em 14 (6,3 por cento) pacientes chagásicos. A média do diâmetro da ampola retal dos chagásicos 6,3 (±1,0)cm foi semelhante a dos não-chagásicos 6,2 (±1,0)cm (p=0,391) e o diâmetro médio da alça sigmoide dos chagásicos 5 (±1,6)cm foi maior que o dos não chagásicos 4,4 (±0,8 )cm, (p=0,001). CONCLUSÕES: Excluindo-se os casos de megacólon evidente e de provável megacólon, a população chagásica continuou com o diâmetro médio do sigmoide significantemente maior (p=0,003) que a não chagásica.

INTRODUCTION: A radiological study on the colon of patients from an endemic Chagas disease zone was conducted using the simplified opaque enema technique of Ximenes et al. METHODS: The study involved 291 individuals with a mean age of 48.8(±12.5) years-old, of whom 222 were seropositive for Chagas disease. Anteroposterior, posteroanterior and left lateral view radiographs were analyzed by visual inspection and measurement of the largest rectal and sigmoid diameters. RESULTS: From the visual inspection, megacolon was diagnosed in 14 (6.3 percent) Chagas disease patients. The mean diameter of the rectal ampulla among the Chagas patients was 6.3 (±1.0)cm, similar to the measurement in non-Chagas individuals: 6.2 (±1.0) cm (p= 0.391). The mean sigmoid loop diameter in the Chagas patients was 5 (±1.6)cm, which was larger than among the non-Chagas individuals: 4.4 (±0.8)cm (p= 0.001). CONCLUSIONS: excluding the evident and probable megacolon cases, the Chagas disease population continued to present a significantly larger mean sigmoid diameter than that observed among non-Chagas individuals (p= 0.003).

Chagas' disease and ageing: the coexistence of other chronic diseases with Chagas' disease in elderly patients / Doença de Chagas e envelhecimento: a associação de outras enfermidades crônicas em pacientes idosos chagásicos

This study aimed to identify the main comorbidities in elderly chagasic patients treated in a reference service and identify possible associations between the clinical form of Chagas' disease and chronic diseases. Ninety patients aged 60 years-old or over were interviewed and their clinical diagnoses recorded. The study population profile was: women (55.6 percent); median age (67 years); married (51.1 percent); retired (73.3 percent); up to four years' education (64.4 percent); and earning less than two minimum wages (67.8 percent). The predominant forms of Chagas' disease were the cardiac (46.7 percent) and mixed forms (30 percent). There was a greater proportion of mild cardiac dysfunction (84.1 percent), frequently in association with megaesophagus. The mean number of concurrent diseases was 2.856 ± 1.845, and 33 percent of the patients had four or more comorbidities. The most frequent were systemic arterial hypertension (56.7 percent), osteoporosis (23.3 percent), osteoarthritis (21.2 percent) and dyslipidemia (20 percent). Positive correlations were verified between sex and comorbidities and between age group and comorbidities.

Este trabalho objetivou avaliar o perfil sociodemográfico e identificar as principais co-morbidades de idosos chagásicos, buscando associação entre forma clínica da doença de Chagas e enfermidades crônicas. Foi realizada entrevista e levantamento dos diagnósticos clínicos de 90 chagásicos com idade > 60 anos. Encontrou-se: mulheres (55,6 por cento), mediana de 67 anos, casados (51,1 por cento) e renda mensal inferior a dois salários-mínimos (67,8 por cento). A forma clínica predominante foi a cardíaca (46,7 por cento), seguida da mista (30 por cento). Houve maior proporção de cardiopatia leve (84,1 por cento), sendo frequente a associação com megaesôfago. Trinta e três por cento apresentavam quatro ou mais co-morbidades, dentre elas: hipertensão arterial (56,7 por cento), osteoporose (23,3 por cento), osteoartrite (21,2 por cento) e dislipidemia (20 por cento). Obteve-se correlação positiva entre gênero e co-morbidades, faixa etária e co-morbidades.

Paleoparasitology of Chagas disease: a review

One hundred years since the discovery of Chagas disease associated with Trypanosoma cruzi infection, growing attention has focused on understanding the evolution in parasite-human host interaction. This interest has featured studies and results from paleoparasitology, not only the description of lesions in mummified bodies, but also the recovery of genetic material from the parasite and the possibility of analyzing such material over time. The present study reviews the evidence of Chagas disease in organic remains excavated from archeological sites and discusses two findings in greater detail, both with lesions suggestive of chagasic megacolon and confirmed by molecular biology techniques. One of these sites is located in the United States, on the border between Texas and Mexico and the other in state of Minas Gerais, in the Brazilian cerrado (savannah). Dated prior to contact with Europeans, these results confirm that Chagas disease affected prehistoric human groups in other regions outside the Andean altiplanos and other transmission areas on the Pacific Coast, previously considered the origin of T. cruzi infection in the human host.

Pre-Columbian Chagas disease in Brazil: Trypanosoma cruzi I in the archaeological remains of a human in Peruaçu Valley, Minas Gerais, Brazil

We evaluated the presence and distribution of Trypanosoma cruzi DNA in a mummy presenting with megacolon that was dated as approximately 560 ± 40 years old. The mummy was from the Peruaçu Valley in the state of Minas Gerais, Brazil. All samples were positive for T. cruzi minicircle DNA, demonstrating the presence and broad dissemination of the parasite in this body. From one sample, a mini-exon gene fragment was recovered and characterized by sequencing and was found to belong to the T. cruzi I genotype. This finding suggests that T. cruzi I infected humans during the pre-Columbian times and that, in addition to T. cruzi infection, Chagas disease in Brazil most likely preceded European colonization.

O perfil dos portadores de doença de Chagas, com ênfase na forma digestiva, em hospital terciário de Ribeirão Preto, SP / Features of Chagas' disease patients with emphasis on digestive form, in a tertiary hospital of Ribeirão Preto, SP

Para caracterizar o perfil clínico e demográfico dos portadores da forma digestiva da doença de Chagas atualmente atendidos no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, foram revistos 377 prontuários de pacientes com resultado positivo para reação sorológica para a doença de Chagas atendidos entre janeiro de 2002 a março de 2003. A idade mediana dos pacientes era de 67 anos e 210 (56 por cento) eram mulheres. Megaesôfago e/ou megacólon chagásicos estavam presentes em 135 pacientes, dos quais, 59 por cento apresentavam cardiopatia. Para 49 por cento dos pacientes com doença digestiva, havia prescrição de pelo menos dois medicamentos para tratamento de doença cardiovascular. Em 66 pacientes, foram detectadas comorbidades crônicas. A população de portadores da forma digestiva da doença de Chagas do HCFMRP é majoritariamente geriátrica e apresenta freqüência elevada de doenças cardiovasculares, o que sugere risco elevado das modalidades de tratamento cirúrgico do megaesôfago e megacólon.