Section I. Basic Bacteriology of H. pylori.- 1. In vivo models of gastric Helicobacter infections.- 2 H. pylori species heterogenicity.- 3 H. pylori urease.- 4 Basic bacteriology of H. pylori: H. pylori colonization factors.- Section II. Prevalence and Mechanisms of Spread of H. pylori.- 5 Epidemiology of H. pylori in Western countries.- 6 H. pylori in developing countries.- 7 Prevalence/disease correlates of H. pylori.- 8 Reinfection with H. pylori.-...