Helicobacter and gastrin stimulate Reg1 expression in gastric epithelial cells through distinct promoter elements.

The gastric pathogen Helicobacter pylori accelerates the progression to gastric cancer but the precise mechanisms that mediate carcinogenesis remain unidentified. We now describe how Helicobacter and gastrin stimulate the expression of a putative growth factor, Reg1, in primary gastric epithelial cells. RT-PCR and Western immunoblotting of human gastric corpus and antrum showed significantly increased Reg1alpha in H.

Serological assays for identification of human gastric colonization by Helicobacter pylori strains expressing VacA m1 or m2.

The Helicobacter pylori vacA gene encodes a secreted protein (VacA) that alters the function of gastric epithelial cells and T lymphocytes. H. pylori strains containing particular vacA alleles are associated with differential risk of disease.

Interleukin-1beta and interleukin-1 receptor antagonist gene polymorphisms and gastric cancer: a meta-analysis.

Background: Polymorphisms of interleukin-1B (IL1B) and its receptor antagonist (IL1RN) genes have been inconsistently associated with gastric cancer risk. We examined these associations by performing meta-analyses.

Materials And Methods: Twenty-five studies testing the association between IL1B and/or IL1RN gene polymorphisms and gastric cancer were examined: 14 studies of IL1B-511, 14 studies of IL1B-31, 8 studies of IL1B+3954, and 23 studies of IL1RN.

The role of decay-accelerating factor as a receptor for Helicobacter pylori and a mediator of gastric inflammation.

Persistent gastritis induced by Helicobacter pylori is the strongest known risk factor for peptic ulcer disease and distal gastric adenocarcinoma, a process for which adherence of H. pylori to gastric epithelial cells is critical. Decay-accelerating factor (DAF), a protein that protects epithelial cells from complement-mediated lysis, also functions as a receptor for several microbial pathogens.

Bacterial biota in reflux esophagitis and Barrett's esophagus.

Aim: To identify the bacterial flora in conditions such as Barrettos esophagus and reflux esophagitis to determine if they are similar to normal esophageal flora.

Methods: Using broad-range 16S rDNA PCR, esophageal biopsies were examined from 24 patients [9 with normal esophageal mucosa, 12 with gastroesophageal reflux disease (GERD), and 3 with Barrettos esophagus]. Two separate broad-range PCR reactions were performed for each patient, and the resulting products were cloned.

Interleukin-17 levels in Helicobacter pylori-infected gastric mucosa and pathologic sequelae of colonization.

Aim: To determine the role of interleukin (IL)-17 in gastric ulcerogenesis.

Methods: Thirty-six gastric ulcer (GU) patients and 29 non-ulcer (NU) patients were enrolled in this study. Mucosal biopsy samples were obtained from the gastric antrum and GU site during endoscopy.

Helicobacter infection and gastric neoplasia.

Chronic gastritis induced by Helicobacter pylori is the strongest known risk factor for adenocarcinoma of the distal stomach, yet only a minority of people who harbour this organism ever develop cancer. H. pylori isolates possess substantial genotypic diversity, which engenders differential host inflammatory responses that influence clinical outcome.

Local and systemic immune and inflammatory responses to Helicobacter pylori strains.

Colonization with Helicobacter pylori eventuates in varied clinical outcomes, which relate to both bacterial and host factors. Here we examine the relationships between cagA status, serum and gastric juice antibody responses, and gastric inflammation in dyspeptic patients. Serum, gastric juice, and gastric biopsy specimens were obtained from 89 patients undergoing endoscopy.

The role of persistence in Helicobacter pylori pathogenesis.

Purpose Of Review: Helicobacter pylori induces chronic gastritis and is the strongest known risk factor for peptic ulcer disease and distal gastric cancer, yet only a fraction of colonized individuals ever develop clinical disease. The aim of this article is to provide an overview of recent advances into mechanisms of H. pylori persistence and to incorporate these findings into our current understanding of H.

Inflammation in the genesis and perpetuation of cancer: summary and recommendations from a national cancer institute-sponsored meeting.

The Inflammation and Cancer Think Tank Meeting was organized by the National Cancer Institute with the purpose of identifying research advances, gaps, and opportunities for the study and clinical application of the role of inflammation on tumorigenesis. The format of this meeting consisted of brief presentations that focused on concepts, with extensive discussion periods to allow participants to identify issues and barriers limiting progress in this area. The strong relationship between inflammation and cancer in the gastrointestinal tract prompted several presentations that were focused on carcinogenesis within this organ system; however, many of the same immune mediators that influence esophageal, gastric, and colorectal carcinoma were also shown to influence inflammation-related malignancies at other anatomic sites.

Activation of beta-catenin by carcinogenic Helicobacter pylori.

Persistent gastritis induced by Helicobacter pylori is the strongest known risk factor for adenocarcinoma of the distal stomach, yet only a fraction of colonized persons ever develop gastric cancer. The H. pylori cytotoxin-associated gene (cag) pathogenicity island encodes a type IV secretion system that delivers the bacterial effector CagA into host cells after bacterial attachment, and cag+ strains augment gastric cancer risk.

Events at the host-microbial interface of the gastrointestinal tract IV. The pathogenesis of Helicobacter pylori persistence.

Long-term interactions between Helicobacter pylori and humans significantly increase the risk for peptic ulcer disease and noncardia gastric adenocarcinoma. The vast majority of infected persons remain persistently colonized unless a targeted antibiotic regimen is employed; thus regulation of inflammation by H. pylori is governed by levels of host-bacteria equilibria that are not found during cellular interactions with acute enteric pathogens.

Pathogenesis of Helicobacter pylori infection.

Helicobacter pylori induces chronic gastritis, the strongest known risk factor for peptic ulcer disease and distal gastric cancer, yet only a fraction of colonized individuals ever develop clinical disease. H. pylori isolates possess substantial genotypic diversity, which engenders differential host inflammatory responses that influence pathologic outcome.

Genomic Comparison of cag pathogenicity island (PAI)-positive and -negative Helicobacter pylori strains: identification of novel markers for cag PAI-positive strains.

In an analysis of Helicobacter pylori genomic DNA by macroarray methodology, genomic DNA from a panel of cag pathogenicity island (PAI)-negative H. pylori clinical isolates failed to hybridize with 27 genes located outside the cag PAI in a cag PAI-positive reference strain. PCR analyses confirmed that HP0217 (encoding a lipopolysaccharide biosynthetic protein) and HP1079 (encoding a protein of unknown function) were present significantly more frequently in cagA-positive strains than in cagA-negative strains.

Evidence for repatterning of the gastric fundic epithelium associated with Ménétrier's disease and TGFalpha overexpression.

Background & Aims: Increase of intramucosal transforming growth factor alpha (TGFalpha) levels in the gastric fundus leads to oxyntic atrophy and massive foveolar hyperplasia in both metallothionein (MT)-TGFalpha mice and patients with Ménétrier's disease. We have evaluated the hypothesis that increased levels of TGFalpha in the fundus induces an antral pattern of cell differentiation in fundic glands by studying Pdx1, a transcription factor whose expression normally is confined to the gastric antrum.

Methods: Induction of Pdx1 expression was evaluated in Pdx1(lacZ/+)/MT-TGFalpha bigenic mice treated with zinc.

Orchestration of aberrant epithelial signaling by Helicobacter pylori CagA.

Persistent colonization by Helicobacter pylori is the strongest risk factor for distal gastric adenocarcinoma, and H. pylori strains that harbor the cag pathogenicity island further augment cancer risk. The H.

Helicobacter pylori protein HP0222 belongs to Arc/MetJ family of transcriptional regulators.

Helicobacter pylori is a widespread human bacterial pathogen responsible for inducing gastric and duodenal ulcers and gastric cancers. To date, only 16 protein structures from this organism have been determined, and more than 30% of its 1500 protein functions remain unknown. We report the biochemical characterization, the tertiary structure determined by solution nuclear magnetic resonance (NMR) methods and the putative function of the previously uncharacterized protein HP0222 (JHP0208) from H.

Subproteomes of soluble and structure-bound Helicobacter pylori proteins analyzed by two-dimensional gel electrophoresis and mass spectrometry.

Helicobacter pylori is one of the most common bacterial pathogens and causes a variety of diseases, such as peptic ulcer or gastric cancer. Despite intensive study of this human pathogen in the last decades, knowledge about its membrane proteins and, in particular, those which are putative components of the type IV secretion system encoded by the cag pathogenicity island (PAI) remains limited. Our aim is to establish a dynamic two-dimensional electrophoresis-polyacrylamide gel electrophoresis (2-DE-PAGE) database with multiple subproteomes of H.

Novel 180- and 480-base-pair insertions in African and African-American strains of Helicobacter pylori.

Helicobacter pylori is a genetically diverse bacterial species that chronically infects human stomachs and sometimes causes severe gastroduodenal disease. Studies of polymorphic DNA sequences can suggest geographic origins of individual strains. Here, we describe a 180-bp insertion (ins180), which is just after the translation stop of a gene of unknown function, near the promoter of jhp0152-jhp0151 two-component signal transduction genes in strain J99, and absent from this site in strain 26695.

Prevention of colorectal cancer through the use of COX-2 selective inhibitors.

Colorectal cancer is a major cause of morbidity and mortality accounting for an estimated 550,000 deaths annually worldwide. Colonic neoplasia develops in a stepwise fashion progressing from normal mucosa to adenomatous polyps to carcinoma, a process that takes years, thereby providing a prime opportunity for intervention. Although early detection by fecal occult blood testing and sigmoidoscopy can decrease the risk of cancer-related death by 20-30%, most persons never undergo appropriate screening.