Answer: The organism generally does not directly invade the epithelial cells but indirectly makes the gastric mucosa more vulnerable to acid peptic damage by disrupting the mucous layer, liberating a variety of enzymes and toxins, and adhering to and altering the gastric epithelium. In addition, the host immune response to H. pylori incites an inflammatory [...]

Answer: The organism lives within or beneath the gastric mucous layer, somewhat protected from stomach acid. H. pylori has potent urease activity, which hydrolyzes urea to ammonia and bicarbonate and increases its resistance to the stomach’s low pH environment. H. pylori recognizes and binds to specific receptors expressed by gastric epithelial cells and, therefore, is [...]

Answer: H. pylori is a spiral-shaped, gram-negative bacterium, 0.5 microns in width and 2-6.5 microns in length. It is distinguished by its multiple sheathed, unipolar flagella and potent urease activity; urease accounts for more than 1% of the organism’s protein weight. Its shape and flagella allow penetration of and movement through the gastric mucus layer [...]

Answer: Patients chronically infected with H. pylori frequently develop gastric and duodenal ulcer disease, especially the latter. Although less common, B-cell lymphoma and adenocarcinoma of the stomach are also associated with chronic gastritis due to H. pylori. Antral-predominant corpus sparing chronic gastritis due to H. pylori is more often associated with duodenal ulcer. Gastritis involving [...]

Answer: Lymphocytic gastritis (LG) is a special form of gastritis, which is characterized by the accumulation of intraepithelial lymphocytes (IELs) containing cytotoxic granules in the surface and foveolar epithelium. The number of IELs in normal gastric mucosa is between 3 and 8 per 100 epithelial cells; a minimal number of 30 IELs per 100 epithelial [...]

Answer: Ménétrier’s disease differs from the other forms of chronic gastritis in that it is not associated with any significant degree of mucosal inflammation. The disease is seen usually in middle-aged adults. They often present with weight loss, diarrhea, and hypoproteinemic edema. Low acid secretion, loss of parietal cell mass, and protein-losing gastropathy are typical [...]

Answer: Granulomatous and eosinophilic gastritis probably do not exist as diseases isolated to the stomach. They are more often associated with other systemic diseases. Granulomatous gastritis, when it involves the stomach, is usually part of the spectrum of Crohn’s disease. Because the antrum is the portion of the stomach most often involved with this disease, [...]