J-D Schulzke

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BACKGROUND Epithelial barrier function is impaired in Crohn's disease. AIM To define the underlying cellular mechanisms with special attention to tight junctions. METHODS Biopsy specimens from the sigmoid colon of patients with mild to moderately active or inactive Crohn's disease were studied in Ussing chambers, and barrier function was determined by(More)
Occludin is an integral membrane protein with four transmembrane domains that is exclusively localized at tight junction (TJ) strands. Here, we describe the generation and analysis of mice carrying a null mutation in the occludin gene. Occludin -/- mice were born with no gross phenotype in the expected Mendelian ratios, but they showed significant postnatal(More)
HT-29, an undifferentiated human colon cell line, is known to differentiate when cultured without glucose. This study aimed to characterize ion transport in the clone HT-29/B6, which was selected from HT-29 cells differentiated by glucose-free culture. HT-29/B6 cells seeded onto filter membranes grew as polarized monolayers, mainly consisting of(More)
BACKGROUND & AIMS Mechanisms of diarrhea in ulcerative colitis (UC) are still unknown. Functional and structural characterization of epithelial barrier and transport properties in ulcerative colitis (UC) was performed. METHODS Inflamed sigmoid colon epithelium from UC patients was studied by alternating current impedance analysis to determine the pure(More)
BACKGROUND AND AIMS Impairment of the gastrointestinal mucosal barrier contributes to progression of HIV infection. The purpose of this study was to investigate the effect of highly active antiretroviral therapy (HAART) on the HIV-induced intestinal barrier defect and to identify underlying mechanisms. METHODS Epithelial barrier function was characterised(More)
BACKGROUND Norovirus infection is the most frequent cause of infectious diarrhoea in the western world. This study aimed to characterise functionally and histomorphologically the diseased duodenum in human biopsies. METHODS Norovirus infection was diagnosed by the Kaplan criteria and confirmed by PCR of stool samples. Duodenal biopsies were obtained(More)
Cytokines are supposed to be mediators in diarrhoeal diseases. The aim of this study is to characterize the effect of tumor necrosis factor-alpha (TNFalpha) on epithelial barrier function in the colonic epithelial cell line HT-29/B6. Active ion transport and barrier function were measured as short-circuit current and transepithelial electrical resistance(More)
Current opinion assumes epithelial integrity during spontaneous apoptotic cell death. We measured, for the first time, the local conductances associated with apoptoses and show leaks of up to 280 nS (mean 48 +/- 19 nS) in human intestinal epithelium. The results disprove the dogma that isolated cell apoptosis occurs without affecting the epithelial cell(More)
BACKGROUND & AIMS In ulcerative colitis (UC), the epithelial barrier is impaired by erosion/ulcer-type lesions and epithelial apoptosis causing local leaks, and generalized tight junction alterations increasing the basal permeability. We quantified the contribution of these mechanisms to the increased colonic ion permeability. METHODS Sigmoid colon was(More)
BACKGROUND & AIMS Abdominal symptoms in the absence of mucosal abnormalities are features of both the irritable bowel syndrome (IBS) and latent/potential celiac disease (cd). To identify a possible subgroup of IBS patients with latent/potential cd, surrogate markers of cd were investigated in IBS patients. METHODS IBS patients suffering from diarrhea (n =(More)