GastritisStomach UlcerHelicobacter pyloriGastric MucosaGastritis, AtrophicHelicobacter InfectionsDuodenal UlcerPeptic UlcerMetaplasiaChronic DiseaseStomachStomach NeoplasmsPyloric AntrumGastroscopyAnti-Ulcer AgentsPeptic Ulcer HemorrhageDyspepsiaStomach DiseasesGastric JuicePepsinogen AAchlorhydriaDuodenitisGastrinsBiopsyLeg UlcerPressure UlcerBile RefluxPepsinogen CAcetic AcidSkin UlcerUreaseHelicobacterEndoscopy, GastrointestinalOmeprazolePeptic Ulcer PerforationHelicobacter heilmanniiCimetidineAtrophyGastric AcidAntigens, BacterialPrecancerous ConditionsCampylobacterAmoxicillinHelicobacter felisGastritis, HypertrophicBacterial ProteinsClarithromycinLymphoma, B-Cell, Marginal ZoneSucralfateRanitidineAntibodies, BacterialPylorusCampylobacter InfectionsBuruli UlcerDuodenumPolymerase Chain ReactionHistamine H2 AntagonistsVagotomyGlycyrrhizaAnti-Inflammatory Agents, Non-SteroidalLewis Blood-Group SystemCytotoxinsFamotidineGenotypeWound HealingPostgastrectomy SyndromesImmunohistochemistryEndoscopyPepsinogensGastrointestinal HemorrhageIndomethacinGastroenterostomyAntacidsAnti-Bacterial AgentsGefarnateDrug Therapy, CombinationIntestinesGastrectomyEndoscopy, Digestive SystemAdenocarcinoma2-PyridinylmethylsulfinylbenzimidazolesRecurrenceMagnesium HydroxideGastrointestinal DiseasesParietal Cells, GastricBismuthDuodenoscopyProton Pump InhibitorsAnemia, PerniciousFollow-Up StudiesRisk FactorsImmunoglobulin GPrevalenceDuodenogastric RefluxUpper Gastrointestinal TractGastric Acidity DeterminationMexicoGene Rearrangement, B-Lymphocyte, Heavy ChainProspective StudiesLansoprazole