GastritisGastritis, AtrophicHelicobacter pyloriGastric MucosaHelicobacter InfectionsMetaplasiaChronic DiseaseStomach NeoplasmsPyloric AntrumStomach UlcerStomachPeptic UlcerPepsinogen AAchlorhydriaGastroscopyDyspepsiaBiopsyDuodenitisDuodenal UlcerPepsinogen CStomach DiseasesGastrinsHelicobacter heilmanniiBile RefluxHelicobacterGastric JuiceUreasePrecancerous ConditionsAtrophyCampylobacterHelicobacter felisEndoscopy, GastrointestinalAntigens, BacterialGastritis, HypertrophicBacterial ProteinsLymphoma, B-Cell, Marginal ZoneAnti-Ulcer AgentsAmoxicillinCampylobacter InfectionsAntibodies, BacterialOmeprazoleClarithromycinPolymerase Chain ReactionLewis Blood-Group SystemCytotoxinsGenotypeImmunohistochemistryDuodenumAdenocarcinomaIntestinesHyperplasiaParietal Cells, GastricAnemia, PerniciousGene Rearrangement, B-Lymphocyte, Heavy ChainMexicoImmunoglobulin GDNA, BacterialPepsinogensImmunoglobulin AAnti-Bacterial AgentsPostgastrectomy SyndromesCase-Control StudiesRetrospective StudiesPrevalenceRisk FactorsInterleukin-1betaSensitivity and SpecificityFollow-Up StudiesPolymorphism, GeneticProspective StudiesDrug Therapy, CombinationEndoscopyEnzyme-Linked Immunosorbent AssaySeverity of Illness IndexAcinonyx