title: A statistical analysis of perforated gastric and duodenal ulcers in Japan during the past 40 years.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D004381:Duodenal Ulcer / Q000150:complications*; D005260:Female; D005767:Gastrointestinal Diseases / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D010439:Peptic Ulcer Perforation / Q000453:epidemiology* / Q000601:surgery; D011183:Postoperative Complications / Q000209:etiology; D013276:Stomach Ulcer / Q000150:complications*