Helicobacter pyloriGastritisHelicobacter InfectionsHelicobacterGastritis, AtrophicGastric MucosaUreaseStomachPyloric AntrumPeptic UlcerStomach NeoplasmsDyspepsiaHelicobacter heilmanniiAmoxicillinGastroscopyClarithromycinMetronidazoleStomach DiseasesHelicobacter hepaticusAnti-Ulcer AgentsMetaplasiaOmeprazoleStomach UlcerBacterial ProteinsPepsinogen AGastritis, HypertrophicBismuthAntibodies, BacterialGastrinsBreath TestsDuodenal UlcerAchlorhydriaBiopsyAnti-Bacterial AgentsDuodenitisAntigens, BacterialPepsinogen CEndoscopy, GastrointestinalChild WelfareLansoprazolePylorusPepsinogensDrug Therapy, CombinationChronic DiseaseProton Pump InhibitorsParietal Cells, GastricDisabled ChildrenGastric JuiceChild BehaviorGastric AcidBile RefluxDNA, BacterialPolymerase Chain ReactionGerbillinaeCampylobacterTinidazoleLewis Blood-Group System2-PyridinylmethylsulfinylbenzimidazolesPrevalenceRanitidineUreaAntacidsHelicobacter felisLymphoma, B-Cell, Marginal ZonePrecancerous ConditionsEndoscopy, Digestive SystemEndoscopyCytotoxinsImmunoglobulin GMolecular Sequence DataFurazolidoneGastrointestinal DiseasesProspective StudiesAnemia, PerniciousGastroesophageal RefluxGastric MucinsChild Health ServicesGastric Acidity DeterminationEnzyme-Linked Immunosorbent AssayAcinonyxChild RearingCase-Control StudiesAtrophyEsophagitisTetracyclineAntitrichomonal AgentsChild, InstitutionalizedOrganometallic CompoundsFecesPenicillinsVirulenceSensitivity and SpecificityGastric FundusRisk FactorsVirulence FactorsBacterial AdhesionChild Behavior DisordersChild PsychologyTreatment OutcomeGenes, Bacterial