GastritisHelicobacter pyloriHelicobacter InfectionsGastritis, AtrophicGastric MucosaHelicobacterMetaplasiaPyloric AntrumStomach NeoplasmsStomachChronic DiseasePeptic UlcerStomach UlcerPepsinogen AUreaseGastroscopyHelicobacter heilmanniiDyspepsiaAchlorhydriaStomach DiseasesDuodenitisPepsinogen CBiopsyGastrinsGastritis, HypertrophicDuodenal UlcerAntigens, BacterialBile RefluxAmoxicillinGastric JuiceBacterial ProteinsAnti-Ulcer AgentsClarithromycinEndoscopy, GastrointestinalOmeprazoleCampylobacterHelicobacter felisPrecancerous ConditionsHelicobacter hepaticusAtrophyAntibodies, BacterialLymphoma, B-Cell, Marginal ZonePolymerase Chain ReactionMetronidazoleParietal Cells, GastricLewis Blood-Group SystemAnti-Bacterial AgentsCytotoxinsCampylobacter InfectionsPepsinogensBismuthAnemia, PerniciousDNA, BacterialGenotypeDrug Therapy, CombinationGastric Acid2-PyridinylmethylsulfinylbenzimidazolesPrevalenceDuodenumRisk FactorsImmunohistochemistryPostgastrectomy SyndromesImmunoglobulin GBreath TestsEndoscopyAcinonyxLansoprazoleAdenocarcinomaProton Pump InhibitorsMolecular Sequence DataProspective StudiesEndoscopy, Digestive SystemIntestinesRetrospective StudiesCase-Control StudiesGerbillinaeEnzyme-Linked Immunosorbent AssayAntacidsH(+)-K(+)-Exchanging ATPaseHyperplasiaImmunoglobulin AGastric FundusGastric Acidity DeterminationFollow-Up StudiesSensitivity and SpecificityTinidazoleGastrointestinal DiseasesMexicoDuodenogastric RefluxAutoimmune DiseasesGastroesophageal RefluxEsophagitisEpithelial CellsPolymorphism, GeneticSeverity of Illness IndexIntrinsic FactorRanitidine