Can sexual transmission support the enzootic cycle of Trypanosoma cruzi?

BACKGROUND Trypanosoma cruzi circulates in sylvatic habitats, mainly through blood-feeding triatomines, although other routes also contribute to its dispersion. Sexual transmission of T. cruzi is an understudied topic, especially among wild mammals. Because of the difficulties inherent to field work, experimentally infected mice are frequently used to evaluate the transmission of T. cruzi. OBJECTIVE This study aimed to evaluate the sexual transmission of T. cruzi in acutely infected mice. METHODS Male and female mice in the acute phase of Chagas disease were mated with naïve partners. Then, parasitological tests, immunohistochemistry, serological assays, and polymerase chain reaction (PCR) assays were used to detect infection. FINDINGS Parasitological analysis showed trypomastigotes in the blood of 20% of the naïve mice after mating with infected partners. Serological assays detected anti-T. cruzi antibodies in all naïve females mated with infected males and in 60% of naïve males mated with infected females. PCR showed T. cruzi nDNA bands for all naïve mice mated with infected partners. The possibility of sexual transmission was also confirmed by visualisation of amastigotes in the testes. MAIN CONCLUSIONS Our results demonstrate that sexual transmission of T. cruzi is an ordinary event that may contribute to maintenance of the parasite's enzootic cycle.

Can sexual transmission support the enzootic cycle of Trypanosoma cruzi?

BACKGROUND: Trypanosoma cruzi circulates in sylvatic habitats, mainly through blood-feeding triatomines, although other routes also contribute to its dispersion. Sexual transmission of T. cruzi is an understudied topic, especially among wild mammals. Because of the difficulties inherent to field work, experimentally infected mice are frequently used to evaluate the transmission of T. cruzi. OBJECTIVE: This study aimed to evaluate the sexual transmission of T. cruzi in acutely infected mice. METHODS: Male and female mice in the acute phase of Chagas disease were mated with naïve partners. Then, parasitological tests, immunohistochemistry, serological assays, and polymerase chain reaction (PCR) assays were used to detect infection. FINDINGS: Parasitological analysis showed trypomastigotes in the blood of 20% of the naïve mice after mating with infected partners. Serological assays detected anti-T. cruzi antibodies in all naïve females mated with infected males and in 60% of naïve males mated with infected females. PCR showed T. cruzi nDNA bands for all naïve mice mated with infected partners. The possibility of sexual transmission was also confirmed by visualisation of amastigotes in the testes. MAIN CONCLUSIONS: Our results demonstrate that sexual transmission of T. cruzi is an ordinary event that may contribute to maintenance of the parasite's enzootic cycle.

Sexual transmission of Trypanosoma cruzi in murine model.

Trypanosoma cruzi is mainly transmitted by blood-sucking triatomines, but other routes also have epidemiological importance, such as blood transfusion and congenital transmission. Although the possibility of sexual transmission of T. cruzi has been suggested since its discovery, few studies have been published on this subject. We investigated acquisition of T. cruzi by sexual intercourse in an experimental murine model. Male and female mice in the chronic phase of Chagas disease were mated with naive partners. Parasitological, serological and molecular tests demonstrated the parasites in tissues and blood of partners. These results confirm the sexual transmission of T. cruzi in mice.

Fatty liver disease in severe obese patients: diagnostic value of abdominal ultrasound.

AIM: To evaluate the sensitivity and specificity of abdominal ultrasound (US) for the diagnosis of hepatic steatosis in severe obese subjects and its relation to histological grade of steatosis. METHODS: A consecutive series of obese patients, who underwent bariatric surgery from October 2004 to May 2005, was selected. Ultrasonography was performed in all patients as part of routine preoperative time and an intraoperative wedge biopsy was obtained at the beginning of the bariatric surgery. The US and histological findings of steatosis were compared, considering histology as the gold standard. RESULTS: The study included 105 patients. The mean age was 37.2+/-10.6 years and 75.2% were female. The histological prevalence of steatosis was 89.5%. The sensitivity and specificity of US in the diagnosis of hepatic steatosis were, respectively, 64.9% (95% CI: 54.9-74.3) and 90.9% (95% CI: 57.1-99.5). The positive predictive value and negative predictive value were, respectively, 98.4% (95% CI: 90.2-99.9) and 23.3% (95% CI: 12.3-39.0). The presence of steatosis on US was associated to advanced grades of steatosis on histology (P=0.016). CONCLUSION: Preoperative abdominal US in our series has not shown to be an accurate method for the diagnosis of hepatic steatosis in severe obese patients. Until another non-invasive method demonstrates better sensitivity and specificity values, histological evaluation may be recommended to these patients undergoing bariatric surgery.

Preoperative upper gastrointestinal endoscopy in obese patients undergoing bariatric surgery: is it necessary?

BACKGROUND: Obesity has been shown to be an important risk factor for several gastrointestinal diseases. However, the indication for preoperative upper gastrointestinal endoscopy (UGE) for all patients before bariatric surgery is controversial. The aim of the present study was to evaluate the spectrum of gastrointestinal diseases detected during preoperative UGE in patients undergoing bariatric surgery and the relevance of this procedure. METHODS: A series of severely obese patients, who had undergone UGE before Roux-en-Y gastric bypass from October 2004 to May 2005 were consecutively enrolled in this study. The demographic and clinical data and endoscopic diagnoses were evaluated. Gastric biopsies were performed in elective patients according to the endoscopic findings. RESULTS: The study included 162 patients, 69.8% of whom were women. The mean age was 36.7 +/- 10.8 years. Abnormal findings were observed in 77.2% of patients. Esophagitis was present in 38.9%, gastritis in 51.2% (erosive gastritis in 49.3% and nonerosive gastritis in 50.7%), gastric ulcers in 1.9%, hiatal hernia, in 8.6%, gastric polyp in .6%, and duodenitis in 6.8% of patients. No patient had esophageal or gastric varices. Helicobacter pylori infection was investigated in 96 patients and was detected in 37.5%. Gastric biopsies were performed in 36 patients, with chronic inflammation found in 72.2%, inflammatory activity in 30.6%, and intestinal metaplasia in 11.1%. Glandular atrophy was not found in any patient. CONCLUSION: The results of our study have shown that the spectrum of gastrointestinal diseases observed in severely obese patients who underwent bariatric surgery is broad. Although this issue remains highly controversial, these findings suggest that systematic preoperative UGE and H. pylori testing should be performed in all patients scheduled to undergo bariatric surgery.

[Nonalcoholic fatty liver disease: clinical and histological characteristics in obese who underwent bariatric surgery]. / Doença hepática gordurosa não alcoólica: caractéristicas clínicas e histológicas em obesos graves submetidos à cirurgia bariátrica.

UNLABELLED: Obesity is an important risk factor of Nonalcoholic Fatty Liver Disease (NAFLD) and it has been considered a predictor of severity of this condition. However, in severe obese patients the spectrum of NAFLD is in discussion. AIM: To describe the clinical and histological characteristics of NAFLD in obese patients submitted to bariatric surgery. METHODOLOGY: The study included 141 severe obese (BMI > or = 35kg/m2) who underwent bariatric surgery from October 2004 to May 2005 had clinical and histological diagnosis of NAFLD. EXCLUSION CRITERIA: alcoholic intake more than 140 g/week, positive markers for other liver diseases. All patients were submitted to hepatic biopsy, as first procedure during the surgery. RESULTS: The mean age of the patients was of 37.3 +/- 11.1 years and 76.4% were female. BMI was greater than 40 kg/m2 in 77.7% of the cases. The frequency of metabolic syndrome was 51.9% (104). Elevated aminotransferases and hepatic steatosis on ultrasound were present in 29.5% (105) and 59.0% (105) respectively. Normal liver biopsy or unspecfic findings were found in 11.3% of the cases and NAFLD in 88.7%: isolated steatosis in 2.8%, steatohepatitis (NASH) in 85.1% (NASH and fibrosis in 76.6%) and cirrhosis in 0.7%. CONCLUSIONS: NAFLD in severe obese patients, in general, was asymptomatic and presented normal enzymes, liver function and ultrasound. However, it has a large histological spectrum and cases of steatohepatitis with fibrosis were more frequent. These results suggest that liver biopsy may be considered during the bariatric surgery to better diagnosis and prognosis of severe obese patients.

Doença hepática gordurosa não alcoólica: caractéristicas clínicas e histológicas em obesos graves submetidos à cirurgia bariátrica / Enfermedad del hígado graso no alcohólico: caracteristicas clínicas e histológicas en obesos sometidos a cirugía bariática / Nonalcoholic fatty liver disease: clinical and histological characteristics in obese who underwent bariatric surgery

Obesidade é considerada um importante fator de risco da Doença Hepática Gordurosa Não Alcoólica (DHGNA), e um significante índice de gravidade da doença. Essa condição vem despertando interesse no estudo de obesos que se submetem à cirurgia bariátrica. Objetivo: Avaliar características clínicas e histológicas da DHGNA nestes indivíduos. Metodologia: O estudo incluiu 141 obesos (IMC≥ 35 kg/m2) submetidos à cirurgia bariátrica de outubro/2004 a maio/2005 tiveram diagnóstico de DHGNA. Foram excluídos os indivíduos com história de ingestão alcoólica (≥ 140g/semana) e portadores de outras doenças hepáticas. Os pacientes foram estudados através de parâmetros clínicos e histológicos. A biópsia hepática foi o primeiro procedimento na cirurgia, e a DHGNA foi graduada em esteatose isolada, esteatohepatite (esteatose com balonização ou fibrose) e cirrose. Resultados: A média de idade dos pacientes foi de 37±11 anos, sendo 76,4% eram do gênero feminino. Obesidade grau III (IMC> 40 kg/m2) esteve presente em 77,7% (141) dos casos, e síndrome metabólica foi observada em 52% (104). Elevação de aminotransferases esteve presente em 30% (31/105) dos casos, e 59% (105) apresentavam esteatose na ultra-sonografia. A biópsia mostrou fígado normal ou alterações inespecíficas em 11,3% dos casos e DHGNA em 88,7%: esteatose em 2,8%, esteato-hepatite em 85,1% (esteato-hepatite com fibrose em 76,6%), e cirrose em 0,7%. Conclusões: Em obesos graves a DHGNA é em geral assintomática e pode não apresentar alterações bioquímicas e ultrassonográficas. Entretanto, apresenta um amplo espectro histológico, com maior freqüência de casos de esteato-hepatite com fibrose. Os resultados sugerem que a biópsia hepática deve ser considerada durante cirurgia bariátrica visando uma melhor orientação destes pacientes.

La obesidad es considerada un factor importante de riesgo para la esteato-hepatitis no alcohólica (EHNA) y es un índice de la gravedad de esta enfermedad. Objetivo: evaluar características clínicas e histológicas de la EHNA en estos pacientes. Metodología: el estudio evaluó 141 obesos (IMC >/= 35 kg/m2) durante la cirugía bariátrica entre octubre de 2004 y mayo de 2005. Los pacientes fueron estudiados através de parámetros clínicos e histológicos. Fueron excluidos los pacientes con historia de ingestión de alcohol (> 140 g/semana) y portadores de otras enfermedades hepáticas. La biopsia fue el primer acto quirúrgico y la EHNA fue graduada como la esteatosis, esteatohepatitis y cirrosis. Resultados: los pacientes presentaban una media de edad de 37±11 años, siendo 76,4% mujeres. Obesidad grado III (IMC>40kg/m2) estuvo presente en 77,7% de los casos, y síndrome metabólico fue observado en 52% (54/104). Aminotransferasas elevadas fue observada en 30% (31/105) de los casos, y 59% (62/105) presentaban esteatosis en la ecografía. La biopsia mostró hígado normal o alteraciones inespecíficas en 11,3% de los casos y EHNA en 88,7%: esteatosis aislada en 2,8%, esteato-hepatitis (EHNA) en 85,1% (EHNA y fibrosis en 76,6%) y cirrosis en 0,7%. Conclusiones: en los obesos graves la EHNA es en general asintomática, puede no presentar alteraciones bioquímicas y ecográficas, pero presenta un amplio espectro histológico, con mayor frecuencia de esteatohepatitis con fibrosis. Los resultados sugieren que la biopsia hepática debe ser considerada para los obesos que fueron sometidos a cirugía bariátrica para mejor orientación clínica y pronóstica.

Obesity is an important risk factor of Nonalcoholic Fatty Liver Disease (NAFLD) and it has been considered a predictor of severity of this condition. However, in severe obese patients the spectrum of NAFLD is in discussion. Aim: To describe the clinical and histological characteristics of NAFLD in obese patients submitted to bariatric surgery. Methodology: The study included 141 severe obese (BMI≥35kg/m2) who underwent bariatric surgery from October 2004 to May 2005 had clinical and histological diagnosis of NAFLD. Exclusion criteria: alcoholic intake more than 140g/week, positive markers for other liver diseases. All patients were submitted to hepatic biopsy, as first procedure during the surgery. Results: The mean age of the patients was of 37.3±11.1 years and 76.4% were female. BMI was greater than 40kg/m2 in 77.7% of the cases. The frequency of metabolic syndrome was 51.9% (104). Elevated aminotransferases and hepatic steatosis on ultrasound were present in 29.5% (105) and 59.0% (105) respectively. Normal liver biopsy or unspecific findings were found in 11.3% of the cases and NAFLD in 88.7%: isolated steatosis in 2.8%, steatohepatitis (NASH) in 85.1% (NASH and fibrosis in 76.6%) and cirrhosis in 0.7%. Conclusions: NAFLD in severe obese patients, in general, was asymptomatic and presented normal enzymes, liver function and ultrasound. However, it has a large histological spectrum and cases of steatohepatitis with fibrosis were more frequent. These results suggest that liver biopsy may be considered during the bariatric surgery to better diagnosis and prognosis of severe obese patients

Dissecção aguda de aorta / Acute dissection aorta

No presente trabalho, os autores fazem uma revisão bibliográfica sobre dissecção aguda de aorta, abordando entre outros aspectos, suas classificações e seu manejo clínico e cirúrgico