Decreased expression of cytochrome P450 protein in non-malignant colonic tissue of patients with colonic adenoma.

Background: Cytochrome P450 (CYP) enzymes in epithelial cells lining the alimentary tract play an important role in both the elimination and activation of (pro-)carcinogens. To estimate the role of cytochrome P450 in carcinogenesis of the colon, expression patterns and protein levels of four representative CYPs (CYP2C, CYP2E1, CYP3A4 and CYP3A5) were determined in colon mucosa of normal and adenomatous colonic tissue of patients with adenomas and disease-free controls.

Methods: Expression of CYP2C, CYP2E1, CYP3A4, and CYP3A5 in colon mucosa of normal and adenomatous colonic tissue of patients with adenoma and disease-free controls was determined by RT-PCR.

Distribution of cytochrome P450 2C, 2E1, 3A4, and 3A5 in human colon mucosa.

Background: Despite the fact that the alimentary tract is part of the body's first line of defense against orally ingested xenobiotica, little is known about the distribution and expression of cytochrome P450 (CYP) enzymes in human colon. Therefore, expression and protein levels of four representative CYPs (CYP2C(8), CYP2E1, CYP3A4, and CYP3A5) were determined in human colon mucosa biopsies obtained from ascending, descending and sigmoid colon.

Methods: Expression of CYP2C, CYP2E1, CYP3A4, and CYP3A5 mRNA in colon mucosa was determined by RT-PCR.

Acute but not chronic ethanol exposure impairs retinol oxidation in the small and large intestine of the rat.

Background And Aim: Ethanol has been shown to inhibit retinol oxidation at the level of alcohol dehydrogenase in liver and colon but not previously in the small intestine. In the present study we investigated how chronic alcohol feeding and acute ethanol exposure affects retinol dehydrogenase activity in the colon and small intestine of the rat.

Methods: Rats were fed ethanol in a liquid diet for six weeks.

Prevalence of small bowel bacterial overgrowth and its association with nutrition intake in nonhospitalized older adults.

Objectives: To determine the prevalence of small bowel bacterial overgrowth (SBBO) in older adults and to assess whether SBBO is associated with abdominal complaints and nutrient intake.

Design: Cross-sectional survey.

Setting: Eight senior residence sites in Stuttgart, Germany.

Phagocytosis and production of reactive oxygen species by peripheral blood phagocytes in patients with different stages of alcohol-induced liver disease: effect of acute exposure to low ethanol concentrations.

Background: In rodents, the development of alcoholic liver disease (ALD) after chronic alcohol feeding was shown to depend on the activity of enzymes that are necessary for production of reactive oxygen species (ROS) in phagocytes. The aim of this study was to determine the formation of ROS by resting and challenged phagocytes of patients with different stages of ALD in the presence of ethanol concentrations commonly found in the blood of alcohol abusers.

Patients And Methods: The release of ROS and the phagocytosis of bacteria by neutrophils and monocytes obtained from 60 patients, who were categorized in three groups due to the severity of ALD, were compared to that of 28 healthy controls.

Gastric alcohol dehydrogenase activity in man: influence of gender, age, alcohol consumption and smoking in a caucasian population.

Aims: The stomach is involved in first-pass metabolism of alcohol in humans. As conflicting data were published regarding the influence of age and gender on the activity of alcohol dehydrogenase (ADH) in human gastric mucosa, the present study aimed at the investigation of these and other potentially confounding factors (alcohol consumption, smoking, drug intake) on its activity in a Caucasian population.

Methods: ADH activity was assessed in endoscopic gastric biopsy specimens from 111 Caucasian subjects aged 20-80 years, of whom 51 were females.

Inhibition of retinol oxidation by ethanol in the rat liver and colon.

Background: Epidemiological evidence has been presented for an increased risk of development of colon cancer after chronic alcohol abuse. Alcohol is degraded by cytosolic alcohol dehydrogenases that also are capable of retinol oxidation. Inhibition of retinol oxidation to retinoic acid has been shown to occur in parallel with profound impairment of intracellular retinoid signal transduction and loss of cell differentiation control.

A diet high in fat and meat but low in dietary fibre increases the genotoxic potential of 'faecal water'.

To determine the effects of different diets on the genotoxicity of human faecal water, a diet rich in fat, meat and sugar but poor in vegetables and free of wholemeal products (diet 1) was consumed by seven healthy volunteers over a period of 12 days. One week after the end of this period, the volunteers started to consume a diet enriched with vegetables and wholemeal products but poor in fat and meat (diet 2) over a second period of 12 days. The genotoxic effect of faecal waters obtained after both diets was assessed with the single cell gel electrophoresis (Comet assay) using the human colon adenocarcinoma cell line HT29 clone 19a as a target.