Cord Blood Stem Cell TransplantationTransplantation, HomologousHematopoietic Stem Cell TransplantationGraft vs Host DiseaseTransplantation ConditioningFetal BloodHematologic NeoplasmsGraft vs Leukemia EffectGraft vs Tumor EffectBone Marrow TransplantationTransplantation, AutologousLeukemiaTreatment OutcomeSpinal CordRetrospective StudiesGraft SurvivalRecurrenceTime FactorsTissue DonorsAcute DiseaseGraft RejectionKidney TransplantationSpinal Cord InjuriesTransplantation ChimeraHistocompatibility TestingSurvival RateImmunosuppressive AgentsT-LymphocytesIsoantigensFollow-Up StudiesHistocompatibilityLymphocyte Culture Test, MixedTransplantsRisk FactorsStem Cell TransplantationWhole-Body IrradiationUmbilical CordTransplantation, IsogeneicProspective StudiesTransplantation ImmunologyBlood BanksImmunosuppressionAntigens, CD34Hematopoietic Stem CellsInfant, NewbornCytomegalovirus InfectionsBusulfanHeart TransplantationSkin TransplantationHLA AntigensLymphocyte ActivationMyeloablative AgonistsTransplantationCyclosporineGraft vs Host ReactionMice, Inbred C57BLLeukemia, Myeloid, AcuteLymphocyte DepletionPeripheral Blood Stem Cell TransplantationChimerismAnemia, AplasticVidarabineMice, Inbred BALB CCells, Cultured