title: Resistant duodenal ulcers.
mesh_terms: D000328:Adult; D000368:Aged; D002927:Cimetidine / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004381:Duodenal Ulcer / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011899:Ranitidine / Q000627:therapeutic use*
chemical_list: D002927:Cimetidine; D011899:Ranitidine