MethotrexateArthritis, RheumatoidArthritisArthritis, ExperimentalArthritis, InfectiousArthritis, JuvenileArthritis, PsoriaticArthritis, ReactivePolyglutamic AcidAntirheumatic AgentsJointsFolic Acid AntagonistsSynovial MembraneTetrahydrofolate DehydrogenaseSynovial FluidAminopterinAntimetabolites, AntineoplasticReduced Folate Carrier ProteinDrug Therapy, CombinationLeukemia L1210SulfasalazineTreatment OutcomeMice, Inbred DBARheumatoid FactorArthritis, GoutySynovitisTrimetrexateFolic AcidImmunosuppressive AgentsSeverity of Illness Indexgamma-Glutamyl HydrolaseLeucovorinTetrahydrofolatesBlood SedimentationDrug ResistanceCyclophosphamideAbortifacient Agents, NonsteroidalDrug Administration ScheduleOsteoarthritisPsoriasisArthrographyAntibodies, MonoclonalCollagen Type IIAntineoplastic Combined Chemotherapy ProtocolsTumor Necrosis Factor-alphaDeoxyuridineImmunoglobulin GPrecursor Cell Lymphoblastic Leukemia-LymphomaDermatologic AgentsVincristineIsoxazolesRats, Inbred LewRheumatic Diseases6-MercaptopurineReceptors, Tumor Necrosis FactorInjections, Intra-ArticularDose-Response Relationship, DrugPregnancy, EctopicRheumatologyAnti-Inflammatory AgentsFluorouracilFormyltetrahydrofolatesAutoantibodiesGold Sodium ThiomalateMetacarpophalangeal JointFolate Receptors, GPI-AnchoredPrednisoneTime FactorsPhosphoribosylaminoimidazolecarboxamide FormyltransferaseDouble-Blind MethodSpondylitis, AnkylosingDoxorubicinRemission InductionPrednisoloneOsteosarcomaInjections, SpinalCytarabineOrganogold CompoundsKnee JointThymidylate SynthaseLeukemia, LymphoidHydroxychloroquineCentral Nervous System NeoplasmsWrist JointPregnancy, TubalFollow-Up StudiesSarcoma 180Pteroylpolyglutamic AcidsGlucocorticoidsHydroxymethyl and Formyl TransferasesAdministration, OralDisease Models, AnimalAsparaginaseAutoimmune DiseasesProspective StudiesAntibodies, Monoclonal, HumanizedGestational Trophoblastic DiseaseBiological TransportCells, CulturedPeptides, Cyclic