GastritisGastritis, AtrophicHelicobacter pyloriGastric MucosaHelicobacter InfectionsPyloric AntrumGastritis, HypertrophicMetaplasiaDNA DamageStomachGastroscopyPepsinogen AStomach NeoplasmsAchlorhydriaBile RefluxStomach UlcerGastrinsPeptic UlcerPepsinogen CStomach DiseasesDuodenal UlcerChronic DiseaseHelicobacter felisHelicobacter heilmanniiParietal Cells, GastricDuodenitisAnemia, PerniciousDyspepsiaBiopsyHelicobacterUreasePepsinogensGastric JuicePostgastrectomy SyndromesPrecancerous ConditionsEndoscopy, GastrointestinalAtrophyCampylobacterAcinonyxEndoscopyAnti-Ulcer AgentsAntigens, BacterialGastric AcidH(+)-K(+)-Exchanging ATPaseAmoxicillinAutoimmune DiseasesOmeprazoleDuodenogastric RefluxGastric FundusAntibodies, BacterialEndoscopy, Digestive SystemGastroenterostomyIntrinsic FactorBacterial ProteinsGastric Acidity DeterminationBismuthThymectomyCampylobacter InfectionsEsophagitisAntacidsLymphocytosisGastrointestinal DiseasesGastroesophageal RefluxGerbillinaeGastrin-Secreting Cells