<prompt> H. Pylori causes all except:Peptic ulcerMaltomaCarcinoid tumorGastric CA  <response>: Ans. c Carcinoid tumorRef: Harrison 19th ed. 1039-1040 H.pylori is gram negative bacteria, non sporing, micro aerophilic, extra cellular bacteria. H.pylori releases urease enzyme which converts urea to ammonia and ammonia stimulates G cells of stomach which inturn stimulates parietal cells and cause secretion of Hcl a Hyperchlorydia. This acid travels into stomach duodenum a causes peptic ulcers . H.pylori is a type I carcinogen, which, if present in stomach for long term can cause cancer called MALTOMA Mucosa Associated Lymphoid Tumor,which is a B-type NHL.Also know MC site of duodenal ulcer in duodenum: D1 V If ulcer at Dl, D2, D3 a Zollinger Ellison Syndrome IOC for H. pylori: Urease test invasive procedure Urea breath test: test for eradication of infection S. Elisa: screening test for H.Pylori 