Volume 115, Issue 3, Pages 642-648 (September 1998) Helicobacter pylori infection induces gastric cancer in Mongolian gerbils  Takeshi Watanabe, Mayumi Tada, Hirofumi Nagai, Satoshi Sasaki, Masafumi Nakao  Gastroenterology  Volume 115, Issue 3, Pages 642-648 (September 1998) DOI: 10.1016/S0016-5085(98)70143-X Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 1 (A) Active chronic gastritis observed in the pyloric region of Mongolian gerbils 6 weeks after H. pylori inoculation. (B) The gastritis is characterized by severe neutrophil and mononuclear cell infiltration in both the mucosa and submucosa. The normal mucosal architecture is almost completely lost and replaced by regenerative hyperplastic epithelium. The thickness of the mucosa increased remarkably compared with that of an uninfected animal (B) (H&E; original magnification 65×). Gastroenterology 1998 115, 642-648DOI: (10.1016/S0016-5085(98)70143-X) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 2 (A) Intestinal metaplasia observed near the ulcer in Mongolian gerbils 39 weeks after H. pylori inoculation. (B) The metaplastic glands are composed of columnar cells and a large number of goblet cells producing sialomucins (blue) and occasionally sulfomucins (gray) (H&E [A] and AB-HID [B]; original magnification 65× [A] and 130× [B]). Gastroenterology 1998 115, 642-648DOI: (10.1016/S0016-5085(98)70143-X) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 3 (A) Intestinal metaplasia observed in the pyloric region of Mongolian gerbils 52 weeks after H. pylori inoculation. (B) The metaplastic glands show complex branching and budding, and enlarged and vesicular nuclei with prominent nucleoli and stratification of nuclei are frequently recognized (H&E; original magnifications 50× [A] and 130× [B]). Gastroenterology 1998 115, 642-648DOI: (10.1016/S0016-5085(98)70143-X) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 4 (A) An adenocarcinoma observed in the pyloric region of a Mongolian gerbil 62 weeks after H. pylori inoculation. (B) The tumor has arisen in the area of intestinal metaplasia in the deep mucosa, and the direction of growth is downward. Penetration into the lamina muscularis and destruction of the original architecture can be observed. (C) Spreading into the serosa of the neoplastic glands is also noted, and these glands show nuclear pleomorphism. (D) The neoplastic glands are composed of intestinal-type epithelium, which contains goblet cells producing predominantly sialomucins (blue). Cystic dilatation of the neoplastic glands with an accumulation of mucus and extracellular mucus pools are frequently seen in the submucosa. (E) Immunohistochemically, almost all tumor cells express p53 protein (H&E; original magnifications 30× [A], 65× [B], 130× [C]; AB-HID, 130× [D]; p53, 130× [E]). Gastroenterology 1998 115, 642-648DOI: (10.1016/S0016-5085(98)70143-X) Copyright © 1998 American Gastroenterological Association Terms and Conditions