title: Duodenal ulcer, gastric acid, and Helicobacter pylori.
mesh_terms: D004381:Duodenal Ulcer / Q000382:microbiology*; D005744:Gastric Acid / Q000378:metabolism; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori; D006801:Humans