GastritisHelicobacter pyloriHelicobacter InfectionsGastric MucosaPyloric AntrumGastritis, AtrophicBiopsyHelicobacterStomachUreaseDyspepsiaStomach NeoplasmsGastroscopyMetaplasiaOmeprazolePeptic UlcerDuodenal UlcerClarithromycinAmoxicillinMetronidazoleGastric Acidity DeterminationGastrinsAnti-Ulcer AgentsBacterial ProteinsGastric JuiceStomach DiseasesStomach UlcerBismuthAntigens, BacterialPepsinogen ABreath TestsHelicobacter heilmanniiAnti-Bacterial AgentsAntibodies, BacterialChronic DiseaseHelicobacter hepaticusLansoprazoleLymphocytosis2-PyridinylmethylsulfinylbenzimidazolesDuodenitisProton Pump InhibitorsDrug Therapy, CombinationEndoscopy, GastrointestinalPepsinogen CTinidazoleLewis Blood-Group SystemAchlorhydriaGastritis, HypertrophicPepsinogensGerbillinaeRanitidineUreaDNA, BacterialGastric AcidPolymerase Chain ReactionImmunohistochemistryFurazolidoneParietal Cells, GastricCytotoxinsAntacidsLymphoma, B-Cell, Marginal ZoneMolecular Sequence DataEndoscopy, Digestive SystemTetracyclineImmunoglobulin GAntitrichomonal AgentsHelicobacter felisPylorusCampylobacterEndoscopy