Larger amounts of nitrite and nitrate-reducing bacteria in megaesophagus of Chagas' disease than in controls.

In the megaesophagus of Chagas' disease, chronic esophagitis is caused by stasis of swallowed food and saliva. In this environment, the overgrowth of aerobic and anaerobic bacteria, including nitrate-reducing bacteria, is observed. The reduction of nitrate into nitrite by the action of these bacteria has been associated with the formation of volatile nitrosamines in different situations of gastric bacterial overgrowth. We have hypothesized that this phenomenon could occur in the esophageal lumen of patients with megaesophagus. To evaluate the concentration of nitrite, the presence of volatile nitrosamines and the concentration of nitrate-reducing bacteria in the esophageal lumen of patients with non-advanced megaesophagus of Chagas' disease and in a group of patients without esophageal disease. Fifteen patients with non-advanced megaesophagus [megaesophagus group (MG)] and 15 patients without any esophageal disease [control group (CG)] were studied. Saliva samples were taken for nitrate and nitrite quantitative determination and esophageal stasis liquid samples were taken for nitrate and nitrite quantitative determination, volatile nitrosamines qualitative determination and reductive bacteria quantitative determination. MG and CG were equivalent in nitrate and nitrite saliva concentration and in nitrate esophageal concentration. Significant difference was found in nitrite (p = 0.003) and reductive bacteria concentration (p < 0.0001), both higher in MG. Volatile nitrosamines were identified in three MG patients and in none of the CG patients, but this was not significant (p = 0.113). There is a higher concentration of reductive bacteria in MG, responsible for the rise in nitrite concentration at the esophageal lumen and, eventually, for the formation of volatile nitrosamines.

An evaluation of gastric scintigraphy pre- and postpyloroduodenal peptic stenosis dilation.

BACKGROUND: The usual treatment of pyloroduodenal peptic stenosis has been mainly surgical, through pyloroplasty or gastric resection, with or without vagotomy. Since the first description of treatment for this peptic complication by endoscopic balloon dilation perfomed by Benjamin in 1982 [2], this procedure has become a therapeutic option in association with the medical treatment of peptic disease. The aim of this study is to evaluate the results involving clinical, endoscopic, and gastric emptying scintigraphy parameters. METHODS: Between August 1998 and February 2000, 20 patients with pyloroduodenal stenosis refractory to conservative treatment were treated at the Gastrointestinal Endoscopy Unit of the University of São Paulo Medical School. All patients who presented clinical manifestations of pyloroduodenal stenosis underwent upper gastrointestinal endoscopy to confirm peptic stenosis. Biopsy of the narrowing for the confirmation of a benign disease and gastric biopsy for Helicobacter pylori detection were performed. The treatment consisted of dilation of the stenosis with type TTS (Through The Scope) hydrostatic balloon under endoscopic control, treatment of Helicobacter pylori infection, and gastric acid suppression with oral administration of proton pump inhibitor. All patients, except one who was excluded from this study, were submitted to a clinical endoscopic assessment and gastric emptying evaluation by ingestion of (99m)Tc before and after the treatment. Endoscopic evaluation considered the diameter of the stenotic area before and after treatment. A scintigraphic study compared the time of gastric emptying before and after balloon dilation. RESULTS: Nineteen patients completed treatment by hydrostatic balloon dilation. Clinical symptoms such as bloating (p < 0.0001), epigastric pain (p = 0.0159), gastric stasis (p < 0.0001), and weight gain (p = 0.036) showed significant improvement. The diameter of the stenotic area increased significantly (p < 0.01) after the dilation treatment as well as a better gastric emptying of (99m)Tc (p < 0.0001). CONCLUSION: The dilation of the peptic pyloroduodenal stenosis using a hydrostatic balloon is a safe and effective procedure. The evaluation with gastric scintigraphy by ingestion of (99m)Tc is an effective method of assessment for the improvement of gastric function, because its results corresponded to the clinical improvement after endoscopic treatment.

Lower esophageal sphincter analysis using computerized manometry in patients with chagasic megaesophagus.

Due to the introduction of computer technology into manometry laboratories, three-dimensional manometric images of the lower esophageal sphincter can be constructed based on radially oriented pressures, a method termed 'computerized axial manometry.' Calculation of the sphincter pressure vector volume using this method is superior to standard manometric techniques in assessing lower esophageal sphincter function in patients with gastroesophageal reflux disease and idiopathic achalasia. Despite similarities between idiopathic achalasia and chagasic esophagopathy found using clinical, radiological, and manometric studies, controversy around lower esophageal sphincter pressure persists. The goal of this study was to analyze esophageal motor disorders in Chagas' megaesophagus using computerized axial manometry. Twenty patients with chagasic megaesophagus (5 men, 15 women, and average age 50.1 years, range 17-64) were prospectively studied. For three-dimensional imaging construction of the lower esophageal sphincter, a low-complacency perfusion system and an eight-channel manometry probe with four radial channels placed in the same level were used. For probe traction, the continuous pull-through technique was used. Results showed that the lower esophageal sphincter of patients with chagasic megaesophagus have significantly elevated pressure, length, asymmetry, and vector volumes compared to those of normal volunteers (P < 0.05). Aperistalsis of the esophageal body waves was observed in all patients and contraction amplitude was lower than that in normal patients. We conclude that patients with chagasic megaesophagus have hypertonic lower esophageal sphincter and aperistalsis of the esophageal body.

Congenital achalasia: facts and fantasies.

Achalasia, a poorly relaxing lower esophageal sphincter, produces a functional obstruction and the expected symptoms of dysphagia, regurgitation and eventually weight loss. The cause of achalasia remains largely unknown in Western countries, Chagas' disease being the most frequent etiology in Brazil. We report on two sets of monozygotic male twins with typical manifestations of achalasia. The majority of authors attribute a limited contribution unless achalasia is related to a multisystem disorder, like the triple-A or Allgrove's syndrome, an autosomal recessive disease characterized by the triad of adrenocorticotropic hormone (ACTH) resistant adrenal insufficiency, achalasia and alacrima. The four cases reported demonstrated the genetic influence of achalasia in patients without multisystem disorders. We believe that idiopathic achalasia is a syndrome with similar clinical, pathological, radiological and manometric evolution, but with a great variety of etiological agents, one of them being the congenital form.

Lipid peroxidation in bariatric candidates with nonalcoholic fatty liver disease (NAFLD) -- preliminary findings.

BACKGROUND: Pathogenesis of nonalcoholic fatty liver disease (NAFLD) remains incompletely known, and oxidative stress is one of the mechanisms incriminated. The aim of this study was to evaluate the role of liver oxidative stress in NAFLD affecting morbidly obese patients. METHODS: 39 consecutive patients with BMI >40 kg/m2 submitted to Roux-en-Y gastric bypass were enrolled, and wedge liver biopsy was obtained during operation. Oxidative stress was measured by concentration of hydroperoxides (CEOOH) in liver tissue. RESULTS: Female gender was dominant (89.7%) and median age was 43.6 +/- 11.1 years. Histology showed fatty liver in 92.3%, including 43.6% with nonalcoholic steatohepatitis (NASH), 48.7% with isolated steatosis and just 7.7% with normal liver. Liver cirrhosis was present in 11.7% of those with nonalcoholic steatohepatitis. Concentration of CEOOH was increased in the liver of patients with NASH when compared to isolated steatosis and normal liver (0.26+/- 0.17, 0.20+/- 0.01 and 0.14+/- 0.00 nmol/mg protein, respectively) (P < 0.01). Liver biochemical variables were normal in 92.3% of all cases, and no difference between NASH and isolated steatosis could be demonstrated. CONCLUSIONS: 1) Nonalcoholic steatosis, steatohepatitis and cirrhosis were identified in substantial numbers of morbidly obese patients; 2) Concentration of hydroperoxides was increased in steatohepatitis, consistent with a pathogenetic role for oxidative stress in this condition.

Is it feasible to reach the bypassed stomach after Roux-en-Y gastric bypass for morbid obesity? The use of the double-balloon enteroscope.

BACKGROUND AND STUDY AIMS: Endoscopic evaluation of the excluded stomach after Roux-en-Y gastric bypass surgery for morbid obesity is a challenge, and the pathological changes that take place in the bypassed stomach are unclear. A new double-balloon method of evaluating the bypassed stomach after Roux-en-Y gastric bypass surgery for morbid obesity is described here. PATIENTS AND METHODS: This new enteroscope uses two balloons, one attached to the tip of the endoscope and the other to the distal end of the soft overtube. The procedures were carried out in six patients using the retrograde route, through the end-to-side jejunal anastomosis via the duodenobiliopancreatic limb up to the bypassed stomach. RESULTS: The bypassed stomach was reached in five of six patients (83.3 %). An endoscopic appearance of atrophic gastritis was found in three patients, mild in two cases and severe in one case with intestinal metaplasia. Erosive and hemorrhagic gastritis was found in two patients. CONCLUSIONS: Endoscopic evaluation of the bypassed stomach via the retrograde route after Roux-en-Y gastric bypass for morbid obesity is feasible using the double-balloon enteroscope.

Gastrectomy with extended lymphadenectomy for primary treatment of gastric cancer.

BACKGROUND: The appropriate extent of lymph node clearance during gastrectomy for cancer remains controversial. METHODS: Medline, Embase, the Cochrane register and other databases were searched for studies reporting node dissection technique, 5 year survival and mortality after gastrectomy. Comparisons with systematic bias in treatment allocation and patients who received perioperative chemotherapy were excluded. Meta-analysis was performed separately for randomized and non-randomized comparisons. RESULTS: Two randomized and two non-randomized comparisons of limited (D1) versus extended (D2) node dissection and 11 reports of one dissection type were analysed. For D2 the randomised trials showed no overall survival benefit (Risk ratio (RR) = 0.95, 95 per cent c.i. 0.83-1.09) and an increased postoperative mortality (RR = 2.23, c.i. 1.45-3.45), apparently related to pancreatico-splenectomy and surgical inexperience. A trend towards survival benefit for D2 was observed for T3+ tumours (RR = 0.68, c.i. 0.42-1.10). Non-randomized comparisons found no survival benefit for D2 (RR = 0.92, c.i. 0.83-1.02), but decreased postoperative mortality (RR = 0.65, c.i. 0.45-0.93). Nine observational studies of D2 reported better results than two studies of D1 surgery, but in very different settings. CONCLUSIONS: Evidence for D2 dissection is inconclusive. No overall survival advantage has emerged, but some patients with intermediate stage disease may benefit. Excess operative mortality appears to be associated with pancreatico-splenectomy, low case volume and lack of specialist training.

Endoscopic ablation of Barrett's esophagus using argon plasma coagulation: a prospective study after fundoplication.

The aim of the prospective clinical study presented here is to test the effectiveness of a multimode approach consisting of argon plasma coagulation combined with laparoscopic fundoplication in the management of Barrett's esophagus. Argon plasma coagulation was performed in 19 patients with Barrett's esophagus who had previously undergone surgical antireflux treatment. The mean follow-up time was 17 months, ranging between 6 and 27 months. Squamous epithelium was completely restored in all patients. In 68.4% of cases two sessions were required. The most frequent complications were chest discomfort and retrosternal pain. In 11 patients the symptoms lasted 3 days and in six cases persisted for a longer period, requiring analgesic medication. Short-term dysphagia and odynophagia were observed in four patients.

Removal of a foreign body from the upper gastrointestinal tract with a flexible endoscope: a prospective study.

BACKGROUND AND STUDY AIMS: There have so far been no prospective studies on the value of flexible endoscopy for removing foreign bodies in the upper gastrointestinal tract. This study presents a clinical analysis of accidents with foreign bodies and prospectively evaluates the effectiveness of flexible endoscopy for removing them. PATIENTS AND METHODS: A total of 105 cases of foreign-body ingestion in the upper gastrointestinal tract were evaluated, 29 (27.6 %) in children and 76 (72.4 %) in adults. Thirty patients (28.5 %) had esophageal strictures. RESULTS: Thirty-nine of the foreign bodies (37.1 %) consisted of food and 66 (62.9 %) were not food-related. The success rate of foreign-body extraction using only a conventional flexible endoscope and accessories for treatment was 98.0 %, and with only a polypectomy snare and rat-toothed forceps it was 91.2 %. Complications at the moment of foreign-body removal occurred in nine patients (8.6 %); there was only one (1 %) esophageal perforation. The incidence of complications related to the duration of foreign-body impaction was six (10.5 %) with foreign bodies impacted for up to 24 h, 13 (52.0 %) for those impacted for 24-48 h, and three (60.0 %) for those impacted for 48-72 h ( P < 0.05). CONCLUSIONS: The flexible endoscope is an effective and safe device for removing foreign bodies from the upper gastrointestinal tract, with a high success rate using only the polypectomy snare and the rat-toothed forceps as accessories. If foreign-body impaction lasts for more than 24 h, there is a significant increase in the incidence of complications.

Severe protein-calorie malnutrition after bariatric procedures.

BACKGROUND: Serious nutritional complications after Roux-en-Y gastric bypass (RYGBP) are infrequent. In a retrospective study of patients operated during a 68-month period, malnutrition was investigated to analyze circumstances associated with nutritional failure. METHODS: In 236 consecutive RYGBPs, 11 patients with severe malnutrition were identified (4.7%) with age 45.1 +/- 10.6 years (10 females/1 male) and initial BMI 54.6 +/- 8.4 kg/m(2). RESULTS: In these 11 patients, the derangement was diagnosed 17.9 +/- 15.8 months after RYGBP, following defined events in 63.6% (gastric stenosis, associated diseases ) or mostly exaggeration of expected symptoms in 36.4% (vomiting without endoscopic abnormalities). BMI then was 31.4 +/- 8.6 kg/m(2) (42.5 +/- 9.9% total reduction, or 2.4 +/- 2.1% decrease/month), and serum albumin and hemoglobin were 24.0 +/- 8.2 g/L and 97.0 +/- 23.0 g/L respectively. Edema was present in 45.4% (5/11), hospitalization was required in 54.5% (6/11), and 18.2% (2/11) eventually died. CONCLUSIONS: Serious malnutrition was unusual but not exceedingly rare in this series. Exogenous precipitating factors were clearly identified in 63.6% of the patients. Careful clinical and nutritional follow-up is recommended to prevent these uncommon but potentially dangerous complications.

Complicaçöes clínicas e hemaológicas da greve de fome / Clinical and hemaologic complicaions of hunger strike

Antecedenes e objeivos - O jejum prolongado em pacienes näo obesos é uma situaçäo potencialmene crítica porém, há muitos anos, näo se documenta seu curso clínico em grandes grupos. Em uma casuística de oito pacientes que recusaram alimentaçäo por 43 dias, as desordens clínicas e hematológicas foram analisadas retrospectivamente. Métodos - As contagens hematológicas documentadas incluíram hemoglobina, leucócitos, linfócitos, eosinófilos e plaquetas. As complicaçöes foram classificadas como gastrointestinais, infecciosas, orodentais e miscelânea. Queixas pré-existentes ou recidivantes foram desconsideradas, computando-se apenas aberraçöes hematológicas e clínicas recém diagnosticadas. Resultados - O total de anormalidades por pacientes foi de 7,5 mais ou menos 1,8 (4-10), conforme enumerado. Hematológicas: Hb menor que 12 g/100 ml 8/8 (100 porcento), leucócitos menor que 4000/mm3 7/8 (87,5 porcento), linfócitos menor que 1000/mm3 7/8(87,5 porcento), plaquetas menor que 150.000/mm3 6/8 (75 porcento). Gastrointestinais: náuseas e vômitos 8/8 (100 porcento), diarréia 4/8 (50 porcento), dor abdominal 1/8 (12,5 porcento), gastrite hemorrágica 1/8 (12,5 porcento). Infecciosas: vias aéreas 1/8 (12,5 porcento), herpes simples 2/8 (25 porcento), herpes zoster 1/8 (12,5 porcento); Orodentais: gengivites hemorrágicas 6/8 (75 porcento), periodontite 2/8 (25 porcento); Miscelânea: brabdicardia e síncope 3/8 (37,5 porcento), erupçäo cutânea 2/8 (25 porcento), reduçäo da acuidade visual 1/8 (12,5 porcento). Conclusöes - 1) A depressäo hematológica afetou as principais linhagens celulares na maioria dos pacientes; 2)A labilidade cardiovascular foi responsável por episódios de brandicardia e hipotensäo; 3) As queixas gastrointestinais foram as mais freqüentes e em um caso (gastrite hemorrágica) atingiram moderada gravidade; 4) A ocorrência de problemas virais foi sugestiva de resposta imonológica diminuída; 5) A maioria das complicaçöes foi progressiva e foi diagnosticada ou se agravou na fase tardia do jejum.(au)

Gastroesophageal reflux disease: clinical, endoscopic, and intraluminal esophageal pH monitoring evaluation.

One hundred and twenty-two patients with gastroesophageal reflux disease were studied (90 with and 32 without esophagitis) with the objective of analyzing possible differences between those with and without esophagitis. Evaluation consisted of clinical interview, endoscopy of the high digestive tract, esophageal manometry, and pH monitoring. There was no significant difference between the groups in age, sex, or symptoms. The incidence of hiatal hernia was greater in the group with esophagitis. Although the frequency of motor changes was similar, the type of anomaly was different. The reflux pattern was very similar in both groups. Therefore, the concept of reflux disease, esophagitis, and pathological reflux still needs a broader definition for greater diagnostic precision and for comparing the results of different studies on the subject. Normal reflux (confirmed using pH esophageal monitoring) in 12.2% of patients with esophagitis suggests that other factors are implicated in the etiology of the disease besides those measured using this examination.

Refeeding procedures after 43 days of total fasting.

Refeeding syndrome encompasses fluid and electrolyte imbalances and metabolic, intestinal, and cardiorespiratory derangements associated with appreciable morbidity and mortality. Although refeeding syndrome has been well documented in concentration-camp subjects, and more recently during parenteral therapy of critically ill patients, little is known about the importance of refeeding syndrome during recovery from a hunger strike. Thus, we studied the response to a four-step dietary replenishment routine in eight hunger strikers who refused food for 43 d. In this retrospective, observational study, we assessed the safety and efficacy of the refeeding procedure and analyzed the clinical and nutritional course of the cohort during both starvation and refeeding, mainly on the basis of clinical as well as a few biochemical determinations. During starvation, average weight loss was about 18% and, with the exception of occasional oral vitamins and electrolytes, the subjects consumed only water. Available body-composition and biochemical profiles showed no clinically significant changes during starvation, but one-half of the group displayed spontaneous diarrhea at some time before refeeding. Stepwise nutritional replenishment lasted for 9 d, after which all patients tolerated a full, unrestricted diet. Only one episode of diarrhea occurred during this phase, and both clinical and biochemical indexes confirmed a favorable clinical course, without any manifestation of refeeding syndrome. In conclusion, we observed the following: 1) Hypophosphatemia and other micronutrient imbalances did not occur, nor was macronutrient intolerance detected. 2) Despite some episodes of diarrhea, nutritional replenishment was not associated with significant enteral dysfunction. 3) There was some fluid retention, but this was mild. 4) Acute-phase markers were abnormally elevated during the refeeding phase, without associated sepsis or inflammation.

[Doppler ultrasonography evaluation of paraumbilical vein and portal hypertension]. / Evaluation par échographie-Doppler de la veine para-ombilicale dans l'hypertension portale.

UNLABELLED: Portal hypertension is associated to the development of portosystemic collateral veins, particularly the paraumbilical vein. PURPOSE: To evaluate the biometric and hemodynamic characteristics of the portal vessels related to the presence of a patent paraumbilical vein, in the setting of portal hypertension secondary to hepatosplenic schistosomiasis. METHODS: 75 patients with portal hypertension secondary to hepatosplenic schistosomiasis were evaluated by Doppler US. The patients were studied based on the presence (group B) or not (Group A) of a patent paraumbilical vein. The diameter and blood flow velocity of the portal vessels and of the paraumbilical vein were recorded. RESULTS: The paraumbilical vein was detected in 17.33% of patients. The results showed an increase of the diameter of the main and left portal vessels whenever a patent paraumbilical vein was present (portal vein: A = 1.14 +/- 0.29 cm/B = 1.33 +/- 0.16 cm; left branch: A = 0.95 +/- 0.25 cm/B = 1.30 +/- 0.24 cm). The mean blood flow velocity was also increased in the portal trunk (A = 15.96 +/- 6.17 cm/sec/B = 19.82 +/- 6.26 cm/sec) and in the left portal branch (A = 14.77 +/- 4.29 cm/sec/B = 19.92 +/- 6.88 cm/sec). CONCLUSION: The presence of a patent paraumbilical vein is related to significant biometric and hemodynamic variations in the portal venous system, in the setting of portal hypertension secondary to hepatosplenic schistosomiasis.

Changes in body fluid and energy compartments during prolonged hunger strike.

UNLABELLED: Prolonged total food deprivation in non-obese adults is rare, and few studies have documented body composition changes in this setting. In a group of eight hunger strikers who refused alimentation for 43 days, water and energy compartments were estimated, aiming to assess the impact of progressive starvation. Measurements included body mass index (BMI), triceps skinfold (TSF), arm muscle circumference (AMC), and bioimpedance (BIA) determinations of water, fat, lean body mass (LBM), and total resistance. Indirect calorimetry was also performed in one occasion. The age of the group was 43.3+/-6.2 years (seven males, one female). Only water, intermittent vitamins and electrolytes were ingested, and average weight loss reached 17.9%. On the last two days of the fast (43rd-44th day) rapid intravenous fluid, electrolyte, and vitamin replenishment were provided before proceeding with realimentation. Body fat decreased approximately 60% (BIA and TSF), whereas BMI reduced only 18%. Initial fat was estimated by BIA as 52.2+/-5.4% of body weight, and even on the 43rd day it was still measured as 19.7+/-3.8% of weight. TSF findings were much lower and commensurate with other anthropometric results. Water was comparatively low with high total resistance, and these findings rapidly reversed upon the intravenous rapid hydration. At the end of the starvation period, BMI (21.5+/-2.6 kg/m2) and most anthropometric determinations were still acceptable, suggesting efficient energy and muscle conservation. CONCLUSIONS: 1) All compartments diminished during fasting, but body fat was by far the most affected; 2) Total water was low and total body resistance comparatively elevated, but these findings rapidly reversed upon rehydration; 3) Exaggerated fat percentage estimates from BIA tests and simultaneous increase in lean body mass estimates suggested that this method was inappropriate for assessing energy compartments in the studied population; 4) Patients were not morphologically malnourished after 43 days of fasting; however, the prognostic impact of other impairments was not considered in this analysis.

Ethnic differences in serum pepsinogen levels among Japanese and non-Japanese Brazilian gastric cancer patients and controls.

A low level of serum pepsinogen I (Pg I) is a risk factor for gastric cancer (GC); low levels of Pg I and the pepsinogen ratio (Pg I:Pg II) are correlated with chronic atrophic gastritis. We report serum Pg levels and compare the degree of association with GC among Japanese and non-Japanese Brazilians. Sera were cross-sectionally ascertained from 93 Japanese Brazilian patients category matched by age and sex with 110 controls, and 228 non-Japanese Brazilian patients individually matched by age and sex with one control. Among non-Japanese Brazilians, GC was associated with a Pg I level <30 ng/ml (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.7-3.8) and a Pg I:Pg II ratio < 3.0 (OR, 3.4; 95% CI, 2.2-5.3). However, among Japanese Brazilians, the association was present with a level of Pg I < 30 ng/ml (OR, 3.5; 95% CI, 1.9-6.3), and was weak with a Pg I:Pg II ratio < 3.0 (OR, 1.3; 95% CI, 0.73-2.4). Serum Pg I may be preferred to the Pg I:Pg II ratio to study the association between Pg and GC among Japanese Brazilians.

Intestinal intussusception and occlusion caused by small bowel polyps in the Peutz-Jeghers syndrome. Management by combined intraoperative enteroscopy and resection through minimal enterostomy: case report.

UNLABELLED: The Peutz-Jeghers syndrome is a hereditary disease that requires frequent endoscopic and surgical intervention, leading to secondary complications such as short bowel syndrome. CASE REPORT: This paper reports on a 15-year-old male patient with a family history of the disease, who underwent surgery for treatment of an intestinal occlusion due to a small intestine intussusception. DISCUSSION: An intra-operative fiberscopic procedure was included for the detection and treatment of numerous polyps distributed along the small intestine. Enterotomy was performed to treat only the larger polyps, therefore limiting the intestinal resection to smaller segments. The postoperative follow-up was uneventful. CONCLUSION: We point out the importance of conservative treatment for patients with this syndrome, especially those who will undergo repeated surgical interventions because of clinical manifestation while they are still young.

Megabladder in experimental Chagas disease: pathological features of the bladder wall.

Mega-organs, primarily in the digestive tract, are well known to occur in chronic Chagas disease. Acute experimental infection with Trypanosoma cruzi results in parasitism of a wide range of cells, tissues, and organs, including the urinary bladder. Infection of BALB/c mice with 100,000 bloodstream forms of the Y strain of T. cruzi induced acute infection with intense parasitism of all layers of the urinary bladder. Parasites were found in the mucosa, lamina propria, muscular, adventitial connective, and fat tissue. Desquamate epithelial cells with amastigotes in the bladder lumen were also found. After 60 days of infection, mice inoculated with 50 bloodstream forms developed dilated, thin-walled bladders that had inflammatory infiltrates and foci of fibrosis replacing areas of damaged muscular layer. These lesions result from direct damage to the muscle fibers by the T. cruzi, leading to myosites, muscle damage, and scarring. Direct damage of paraganglia cells secondary to parasitism, leading to dilatation, damage of muscle fibers, and scarring with replacement of muscular tissue with connective tissue, should also be considered as a cause of functional disturbance of the urinary bladder.