The distribution and chemical coding of enteroendocrine cells in Trypanosoma cruzi-infected individuals with chagasic megacolon.

Chagas disease is caused by the parasite, Trypanosoma cruzi that causes chronic cardiac and digestive dysfunction. Megacolon, an irreversible dilation of the left colon, is the main feature of the gastrointestinal form of Chagas disease. Patients have severe constipation, a consequence of enteric neuron degeneration associated with chronic inflammation. Dysmotility, infection, neuronal loss and a chronic exacerbated inflammation, all observed in Chagas disease, can affect enteroendocrine cells (EEC) expression, which in turn, could influence the inflammatory process. In this study, we investigated the distribution and chemical coding of EEC in the dilated and non-dilated portion of T. cruzi-induced megacolon and in non-infected individuals (control colon). Using immunohistochemistry, EECs were identified by applying antibodies to chromogranin A (CgA), glucagon-like peptide 1 (GLP-1), 5-hydroxytryptamine (5-HT), peptide YY (PYY) and somatostatin (SST). Greater numbers of EEC expressing GLP-1 and SST occurred in the dilated portion compared to the non-dilated portion of the same patients with Chagas disease and in control colon, but numbers of 5-HT and PYY EEC were not significantly different. However, it was noticeable that EEC in which 5-HT and PYY were co-expressed were common in control colon, but were rare in the non-dilated and absent in the dilated portion of chagasic megacolon. An increase in the number of CgA immunoreactive EEC in chagasic patients reflected the increases in EEC numbers summarised above. Our data suggests that the denervation and associated chronic inflammation are accompanied by changes in the number and coding of EEC that could contribute to disorders of motility and defence in the chagasic megacolon.

Pediatric sigmoid volvulus due to Chagas disease.

Exposure and infections by Trypanosoma cruzi are the fourth cause of loss of potential life years between parasitic and infectious diseases. We describe the case of a 11-year-old patient with intestinal occlusion, surgically treated with intestinal volvulus, the surgical specimen is sent to histopathology reporting Chagasic megacolon. The age range of presentation is a challenge in the absence of nonspecific symptoms. There is no pediatric statistical data that define trypanosomiasis in a latent or chronic state and will be diagnosed in adult stages due to the physiopathological alterations that they will present.

La exposición y las infecciones por Trypanosoma cruzi ocupan el cuarto lugar entre las causas de pérdida de años de vida potenciales por enfermedades parasitarias e infecciosas. Se describe el caso de un niño de 11 años, con cuadro de oclusión intestinal, intervenido quirúrgicamente con datos de vólvulo intestinal. La pieza quirúrgica se envió a histopatología, que reportó megacolon chagásico. El rango de edad de presentación es un reto ante la falta de síntomas inespecíficos. No se cuenta con datos estadísticos pediátricos que definan la tripanosomiasis en estado latente o crónico, y estos niños serán diagnosticados en la etapa adulta por las alteraciones fisiopatológicas que presentarán.

5-HT3A serotonin receptor in the gastrointestinal tract: the link between immune system and enteric nervous system in the digestive form of Chagas disease.

Chagas disease is caused by Trypanosoma cruzi and remains one of the most neglected diseases in Latin America. One of its clinical forms is Chagas megacolon. Despite being known for more than half a century, detailed causes are still obscure. Recent evidence indicates a close relationship between the immune system and the enteric nervous system in the etiology of chagasic megacolon pathology. It is believed that low expression of the 5-HT3A serotonin receptor on lymphocytes could be linked to megacolon development. To test this hypothesis, this work investigated the distribution of CD4, CD8, and CD20 lymphocytes and their 5-HT3A receptor expression. The results demonstrated that Chagas patients without megacolon present a higher expression of the 5-HT3A receptor in all analyzed lymphocytes compared with Chagas patients with megacolon. These data suggest that the high expression of this receptor may lead to immunomodulation and prevent the development of Chagas megacolon.

RADIOLOGICAL STUDY OF MEGACOLON IN TRYPANOSOMA CRUZI INFECTED RATS.

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.

Mast Cells and Serotonin Synthesis Modulate Chagas Disease in the Colon: Clinical and Experimental Evidence.

BACKGROUND: Trypanosoma cruzi (T. cruzi) infects millions of Latin Americans each year and can induce chagasic megacolon. Little is known about how serotonin (5-HT) modulates this condition. Aim We investigated whether 5-HT synthesis alters T. cruzi infection in the colon. MATERIALS AND METHODS: Forty-eight paraffin-embedded samples from normal colon and chagasic megacolon were histopathologically analyzed (173/2009). Tryptophan hydroxylase 1 (Tph1) knockout (KO) mice and c-KitW-sh mice underwent T. cruzi infection together with their wild-type counterparts. Also, mice underwent different drug treatments (16.1.1064.60.3). RESULTS: In both humans and experimental mouse models, the serotonergic system was activated by T. cruzi infection (p < 0.05). While treating Tph1KO mice with 5-HT did not significantly increase parasitemia in the colon (p > 0.05), rescuing its synthesis promoted trypanosomiasis (p < 0.01). T. cruzi-related 5-HT release (p < 0.05) seemed not only to increase inflammatory signaling, but also to enlarge the pericryptal macrophage and mast cell populations (p < 0.01). Knocking out mast cells reduced trypanosomiasis (p < 0.01), although it did not further alter the neuroendocrine cell number and Tph1 expression (p > 0.05). Further experimentation revealed that pharmacologically inhibiting mast cell activity reduced colonic infection (p < 0.01). A similar finding was achieved when 5-HT synthesis was blocked in c-KitW-sh mice (p > 0.05). However, inhibiting mast cell activity in Tph1KO mice increased colonic trypanosomiasis (p < 0.01). CONCLUSION: We show that mast cells may modulate the T. cruzi-related increase of 5-HT synthesis in the intestinal colon.

Mast cell-nerve interaction in the colon of Trypanosoma cruzi-infected individuals with chagasic megacolon.

Chagas disease is an infection caused by the parasite Trypanosoma cruzi that affects millions of people worldwide and is endemic in Latin America. Megacolon is the most frequent complication of the digestive chronic form and happens due to lesions of the enteric nervous system. The neuronal lesions seem to initiate in the acute phase and persist during the chronic phase, albeit the mechanisms involved in this process are still debated. Among the cells of the immune system possibly involved in this pathological process is the mast cell (MC) due to its well-known role in the bi-directional communication between the immune and nervous systems. Using ultrastructural analysis, we found an increased number of degranulated MCs in close proximity to nerve fibers in infected patients when compared with uninfected controls. We also immunostained MCs for the two pro-inflammatory molecules tryptase and chymase, the first being also important in neuronal death. The number of MCs immunostained for tryptase or chymase was increased in patients with megacolon, whereas increased tryptase staining was additionally observed in patients without megacolon. Moreover, we detected the expression of the tryptase receptor PAR2 in neurons of the enteric nervous system, which correlated to the tryptase staining results. Altogether, the data presented herein point to the participation of MCs on the denervation process that occurs in the development of T. cruzi-induced megacolon.

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.

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. .

Interstitial cells of Cajal: crucial for the development of megacolon in human Chagas' disease?

AIM: Megacolon, chronic dilation of a colonic segment,is accompanied by extensive myenteric neuron loss. However, this fails to explain unequivocally the formation of megacolon. We aimed to study further enteric structures that are directly or indirectly involved in colonic motility. METHOD: From surgically removed megacolon segments of seven Chagasic patients, three sets of cryosections from oral, megacolonic and anal zones were immunohistochemically quadruple-stained for smooth-muscle actin (SMA), synaptophysin (SYN, for nerve fibres), S100 (glia) and c-Kit (interstitial cells of Cajal, ICCs). Values of area measurements were related to the appropriate muscle layer areas and these proportions were compared with those of seven non-Chagasic control patients. RESULTS: Whereas nerve and glia profile proportions did not mirror unequivocally the changes of Chagasic colon calibre (nondilation/dilation/nondilation), the proportions of SMA (i.e. muscle tissue density) and c-Kit (i.e. ICC density) did so: they decreased from the oral to the megacolonic segment but increased to the anal zones (muscle tissue density: control 68.3%, oral 54.3%, mega 42.1%, anal 47.6%; ICC-density: control 1.8%, oral 1.1%, mega 0.4, anal 0.8%). CONCLUSION: Of the parameters evaluated, muscle tissue and ICC densities may be involved in the formation of Chagasic megacolon, although the mechanism of destruction cannot be deduced.

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.

Chronic Chagas disease with cardiodigestive involvement and the TcVI infective form of Trypanosoma cruzi. A case report.

We report a patient with megacolon associated with TcVI infective lineage form of Trypanosoma cruzi. Although this megacolon was considered idiopathic, Chagas disease was suspected and diagnosed because of the concomitant cardiovascular involvement. Based on this case, we discuss the suitability of Chagas diagnosis in patients with tract motility involvement.

Reduced population of interstitial cells of Cajal in Chagasic megacolon.

BACKGROUND/AIMS: In Chagasic megacolon, there is a reduction in the population of interstitial cells of Cajal. It was aimed to evaluate density of Cajal cells in the resected colon of Chagasic patients compared to control patients and to verify possible association between preoperative and postoperative bowel function of megacolon patients and cell count. METHODOLOGY: Sixteen megacolon patients (12 female; mean age 54.4 (31-73)) were operated on. Pre- and postoperative evaluation using Cleveland clinic constipation score was undertaken. Resected colons were examined. Cajal cells were identified by immunohistochemistry (anti-CD117). The mean cell number was compared to resected colons from 16 patients (7 female; mean age 62.8 (23-84)) with non-obstructive sigmoid cancer. Association between pre- and postoperative constipation scores and cell count for megacolon patients was evaluated using the Pearson test (r). RESULTS: A reduced number of Cajal cells (per field: 2.84 (0-6.6) vs. 9.68 (4.3-13); p<0.001) were observed in the bowel of megacolon patients compared to cancer patients. No correlation between constipation score before (r=- 0.205; p=0.45) or after surgery (r=0.291; p=0.28) and cell count in megacolon was observed. CONCLUSIONS: Patients with megacolon display marked reduction of interstitial cells of Cajal. An association of constipation severity and Cajal cells depopulation was not demonstrated.

Long-term follow up of abdominal rectosigmoidectomy with posterior end-to-side stapled anastomosis for Chagas megacolon.

AIM: Chagas' disease is an endemic parasitosis found in Latin America. The disease affects different organs, such as heart, oesophagus, colon and rectum. Megacolon is the most frequent long-term complication, caused by damage to the myoenteric and submucous plexus, ultimately leading to a functional barrier to the faeces. Patients with severe constipation are managed surgically. The study aimed to analyse the 10-year minimum functional outcome after rectosigmoidectomy with posterior end-to-side anastomosis (RPESA). METHOD: A total of 21 of 46 patients were available for follow up. Patients underwent clinical, radiological and manometric evaluation, and the results were compared with preoperative parameters. RESULTS: Of the 21 patients evaluated, 81% (17) were female, with a mean age of 60.6 years. Good function was achieved in all patients, with significant improvement in defaecatory frequency (P < 0.0001), usage of enemas (P < 0.0001) and patient satisfaction. Barium enema also showed resolution of the colonic and rectal dilatation in 19 cases evaluated postoperatively. CONCLUSION: Minimal 10-year follow up of RPESA showed excellent functional results, with no recurrence of constipation.

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

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%) 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).