MethotrexatePolyglutamic AcidAntirheumatic AgentsFolic Acid AntagonistsTetrahydrofolate DehydrogenaseArthritis, RheumatoidAminopterinAntimetabolites, AntineoplasticLeukemia L1210Reduced Folate Carrier ProteinWorkTrimetrexateFolic Acidgamma-Glutamyl HydrolaseDrug Therapy, CombinationLeucovorinTetrahydrofolatesAbortifacient Agents, NonsteroidalCyclophosphamideDrug ResistanceTreatment OutcomeAntineoplastic Combined Chemotherapy ProtocolsImmunosuppressive AgentsSulfasalazineVincristineDeoxyuridinePrecursor Cell Lymphoblastic Leukemia-LymphomaDrug Administration Schedule6-MercaptopurineDermatologic AgentsPregnancy, EctopicFluorouracilFormyltetrahydrofolatesFolate Receptors, GPI-AnchoredDoxorubicinDose-Response Relationship, DrugPhosphoribosylaminoimidazolecarboxamide FormyltransferaseOsteosarcomaInjections, SpinalPrednisoneCytarabineThymidylate SynthaseLeukemia, LymphoidHydroxychloroquineCentral Nervous System NeoplasmsPregnancy, TubalSarcoma 180Pteroylpolyglutamic AcidsIsoxazolesPsoriasisAsparaginaseBiological TransportGestational Trophoblastic DiseaseRemission InductionTime FactorsHydroxymethyl and Formyl TransferasesProbenecidMucositisWork Schedule ToleranceNucleotide DeaminasesCarcinoma, Ehrlich TumorAntibodies, MonoclonalWork Capacity EvaluationVinblastineDouble-Blind MethodCombined Modality TherapyArthritis, JuvenileArthritis, PsoriaticKineticsAdministration, OralTrophoblastic NeoplasmsReturn to WorkLeukemia L5178Severity of Illness IndexCisplatinBreast NeoplasmsHypoxanthinesAntineoplastic Agents