Gastric MucosaHelicobacter pyloriGastritisHelicobacter InfectionsPyloric AntrumStomach UlcerStomach NeoplasmsParietal Cells, GastricHelicobacter heilmanniiStomachBiopsyIntestinal MucosaBacterial ProteinsIsoenzymesImmunohistochemistryMouth MucosaStomach DiseasesGastric JuiceMetaplasiaNasal MucosaGastric AcidChoristomaGastritis, AtrophicGastrinsGastric MucinsPepsinogensAnti-Ulcer AgentsH(+)-K(+)-Exchanging ATPaseGastroscopyHelicobacterHydrochloric AcidMucous MembraneGastric FundusPentagastrinDuodenumPrecancerous Conditions