GastritisHelicobacter pyloriHelicobacter InfectionsGastritis, AtrophicGastric MucosaHelicobacterMetaplasiaPyloric AntrumStomach NeoplasmsStomachChronic DiseasePeptic UlcerStomach UlcerPepsinogen AUreaseGastroscopyHelicobacter heilmanniiDyspepsiaAchlorhydriaStomach DiseasesDuodenitisBiopsyPepsinogen CGastrinsIncidenceDuodenal UlcerGastritis, HypertrophicAntigens, BacterialBile RefluxAmoxicillinGastric JuiceBacterial ProteinsAnti-Ulcer AgentsClarithromycinEndoscopy, GastrointestinalOmeprazoleCampylobacterPrecancerous ConditionsHelicobacter felisHelicobacter hepaticusAtrophyAntibodies, BacterialLymphoma, B-Cell, Marginal ZonePolymerase Chain ReactionMetronidazoleParietal Cells, GastricAnti-Bacterial AgentsLewis Blood-Group SystemCampylobacter InfectionsRisk FactorsCytotoxinsPepsinogensBismuthGenotypeAnemia, PerniciousDNA, BacterialDrug Therapy, CombinationPrevalenceRetrospective StudiesProspective StudiesGastric Acid2-PyridinylmethylsulfinylbenzimidazolesImmunohistochemistryDuodenumImmunoglobulin GPostgastrectomy SyndromesAdenocarcinomaEndoscopyFollow-Up StudiesBreath TestsAcinonyxLansoprazoleCase-Control StudiesProton Pump InhibitorsMolecular Sequence DataEndoscopy, Digestive SystemIntestinesEnzyme-Linked Immunosorbent AssayGerbillinaeHyperplasiaAntacidsTime FactorsH(+)-K(+)-Exchanging ATPaseImmunoglobulin ASensitivity and SpecificityGastric Acidity DeterminationGastric FundusTreatment OutcomeGastrointestinal DiseasesMexicoSeverity of Illness IndexTinidazoleAutoimmune DiseasesDuodenogastric RefluxGastroesophageal RefluxPolymorphism, GeneticEsophagitisEpithelial CellsIntrinsic FactorRanitidine