Search results for " Colitis."

Induction of CD36 and thrombospondin-1 in macrophages by hypoxia-inducible factor 1 and its relevance in the inflammatory process.

2012

Inflammation is part of a complex biological response of vascular tissue to pathogens or damaged cells. First inflammatory cells attempt to remove the injurious stimuli and this is followed by a healing process mediated principally by phagocytosis of senescent cells. Hypoxia and p38-MAPK are associated with inflammation, and hypoxia inducible factor 1 (HIF-1) has been detected in inflamed tissues. We aimed to analyse the role of p38-MAPK and HIF-1 in the transcriptional regulation of CD36, a class B scavenger receptor, and its ligand thrombospondin (TSP-1) in macrophages and to evaluate the involvement of this pathway in phagocytosis of apoptotic neutrophils. We have also assessed HIF-1α, p…

Mast Cells Infiltrating Inflamed or Transformed Gut Alternatively Sustain Mucosal Healing or Tumor Growth.

2015

Abstract Mast cells (MC) are immune cells located next to the intestinal epithelium with regulatory function in maintaining the homeostasis of the mucosal barrier. We have investigated MC activities in colon inflammation and cancer in mice either wild-type (WT) or MC-deficient (KitW-sh) reconstituted or not with bone marrow-derived MCs. Colitis was chemically induced with dextran sodium sulfate (DSS). Tumors were induced by administering azoxymethane (AOM) intraperitoneally before DSS. Following DSS withdrawal, KitW-sh mice showed reduced weight gain and impaired tissue repair compared with their WT littermates or KitW-sh mice reconstituted with bone marrow-derived MCs. MCs were localized i…

QS159. Structural Adaptations Increase Mucosal Capillary Density in Prolonged Murine Colitis

2008

Autocatalytic cleavage of Clostridium difficile toxin B.

2007

Clostridium difficile, the causative agent of nosocomial antibiotic-associated diarrhoea and pseudomembranous colitis, possesses two main virulence factors: the large clostridial cytotoxins A and B. It has been proposed that toxin B is cleaved by a cytosolic factor of the eukaryotic target cell during its cellular uptake. Here we report that cleavage of not only toxin B, but also all other large clostridial cytotoxins, is an autocatalytic process dependent on host cytosolic inositolphosphate cofactors. A covalent inhibitor of aspartate proteases, 1,2-epoxy-3-(p-nitrophenoxy)propane, completely blocked toxin B function on cultured cells and was used to identify its catalytically active prote…

The Bile Acid Receptor GPBAR-1 (TGR5) Modulates Integrity of Intestinal Barrier and Immune Response to Experimental Colitis

2011

Background GP-BAR1, a member G protein coupled receptor superfamily, is a cell surface bile acid-activated receptor highly expressed in the ileum and colon. In monocytes, ligation of GP-BAR1 by secondary bile acids results in a cAMP-dependent attenuation of cytokine generation. Aims To investigate the role GP-BAR1 in regulating intestinal homeostasis and inflammation-driven immune dysfunction in rodent models of colitis. Methods Colitis was induced in wild type and GP-BAR1−/− mice by DSS and TNBS administration. Potential GP-BAR1 agonists were identified by in silico screening and computational docking studies. Results GP-BAR1−/− mice develop an abnormal morphology of colonic mucous cells a…

The Lung in Inflammatory Bowel Disease†

1993

Respiratory involvement in patients with inflammatory bowel disease (IBD) has been reported mainly since 1976. This form of involvement should clearly be separated from interstitial lung disease due to sulfasalazine or mesalamine, although the distinction may be difficult in some cases. We report the data of an ongoing Registry containing 33 cases (23 cases receiving no drug therapy) with ulcerative colitis or, less often, Crohn's disease, who developed varied bronchopulmonary problems. In several cases, the exact diagnosis and the relation of the bronchopulmonary disease to IBD had not been established for many years, thus delaying effective treatment with steroids. In most cases (28/33), …

Confocal laser endomicroscopy: technical status and current indications.

2006

Confocal laser endomicroscopy is a newly introduced endoscopic tool that makes it possible to carry out confocal microscopic examination of the mucosal layer during ongoing endoscopy. Different types of tissue and diseases can be diagnosed immediately, facilitating early diagnosis of gastrointestinal cancer. Analysis of the in vivo microarchitecture is helpful in targeting biopsies to relevant areas. In addition, subsurface imaging can unmask microscopic diseases - (microscopic colitis) or bacterial infection ( HELICOBACTER PYLORI), for example. Molecular imaging is becoming feasible, and this will shortly open the door to new indications in gastrointestinal endoscopy (e.g., in vivo recepto…

Advances in confocal laser endomicroscopy for the diagnosis of gastrointestinal diseases

2009

Confocal laser endomicroscopy (CLE) is a novel technique enabling in vivo microscopy of the human gastrointestinal mucosa. Cellular details even below the tissue surface can be visualized at high resolution during ongoing endoscopy.This review summarizes the current clinical data on the use of CLE in different disease states and discusses a perspective for future clinical and scientific application of CLE.Review on published literature and meeting abstracts.Confocal laser endomicroscopy covers a growing field of indications in both upper and lower gastrointestinal endoscopy and beyond. It has been shown to reliably predict the presence of neoplastic lesions and inflammatory changes of the g…

Chromoendoscopy: What Is Its True Value for Ulcerative Colitis Surveillance?

2010

Advanced imaging technologies are enabling targeted biopsies or endoscopic resections due to better visualization of the mucosal architecture. This new concept of ‘smart biopsies’ is in particular important for patients with higher risk for development cancer (e.g. ulcerative colitis) but can also be beneficial for screening purposes. This short review will focus on new imaging modalities like chromoendoscopy, digital chromoendoscopy, high-definition endoscopy and confocal laser endomicroscopy in the lower GI tract which will be crucial in the future to detect colorectal neoplasia earlier then before.

Pathogenesis of Crohn’s disease: Bug or no bug

2015

The possibility of an infectious origin in inflammatory bowel disease (IBD) has been postulated since the first description of Crohn’s disease (CD). Many observations implicate bacteria as a trigger for the development of CD: lesions occur in regions with higher bacterial concentrations; aphthous ulcers occur in Peyer’s patches; inflammation resolves when the fecal stream is diverted and is reactivated following reinfusion of bowel contents; severity of the disease is correlated with bacterial density in the mucosa; granulomas can contain bacteria; and susceptible mice raised in germ-free conditions develop inflammation when bacteria are introduced in the 1990’s, several studies sought to e…