Gastric infection with Helicobacter pylori activates a mucosal inflammatory response by mononuclear cells and neutrophils that includes expression of cytokines interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor alpha, and IL-8. In this study, we analyzed the IL-8 response of human gastric cancer cell lines (Kato III, AGS, and MKN28) to H. pylori infection in vitro. IL-8 mRNA expression...

background :   vaculating cytotoxic a ( vaca ) gene is one of the multiple helicobacter pylori genotypes that produce a cytotoxin protein (vaca).this gene is a major cause of chronic peptic ulcers and gastric cancer. the aim of this study was to determine the correlation between vaca gene with peptic ulcer disease (pud) and non-ulcer dyspepsia (nud).   methods :    this was a case control study...

Helicobacter pylori VacA is a secreted protein toxin that forms channels in lipid bilayers and induces multiple structural and functional alterations in eukaryotic cells. A unique hydrophobic segment at the amino terminus of VacA contains three tandem repeats of a GxxxG motif that is characteristic of transmembrane dimerization sequences. To examine functional properties of this region, we expr...

In this study, we describe the ultrastructural changes associated with acid activation of Helicobacter pylori vacuolating cytotoxin (VacA). Purified VacA molecules imaged by deep-etch electron microscopy form approximately 30-nm hexagonal "flowers," each composed of an approximately 15-nm central ring surrounded by six approximately 6-nm globular "petals." Upon exposure to acidic pH, these olig...

objective: helicobacter pylori is a major etiological agent in gastro-duodenal disorders, and has spread in the world. the prevalence of infection with h. pylori is more than 80% in some populations, but only 10% to 20% of them are infected with this organism. also infection with this pathogen is associated with peptic ulcer disease (pud), gastritis (g), duodenitis (du), and non-ulcer dyspepsi...

Polarized epithelial monolayers of Madin-Darby canine kidney (MDCK) cells were used to study the pathogenicity of Helicobater pylori, with an emphasis on the effect of VacA. The adherence of H. pylori to MDCK monolayers resulted in a decrease in trans-epithelial resistance (TER) across the cell monolayer. Isogenic vacA mutants did not lower the TER, demonstrating that the effect is strictly lin...

Platelets were activated under the infection with H. pylori in human and mice. We investigated the role of VacA, an exotoxin released by H. pylori in this context. Acid-activated VacA, but not heated VacA, induced platelet CD62P expression. However, VacA reacted with none of the alleged VacA receptors present on platelet membranes. We therefore analyzed VacA associated proteins obtained through...