Cord Blood Stem Cell TransplantationTransplantation, HomologousHematopoietic Stem Cell TransplantationGraft vs Host DiseaseTransplantation ConditioningFetal BloodHematologic NeoplasmsGraft vs Leukemia EffectGraft SurvivalGraft vs Tumor EffectTransplantation, AutologousLeukemiaBone Marrow TransplantationSpinal CordTreatment OutcomeRetrospective StudiesRecurrenceTime FactorsAcute DiseaseSpinal Cord InjuriesTransplantation ChimeraSurvival RateIsoantigensT-LymphocytesFollow-Up StudiesHistocompatibility TestingLymphocyte Culture Test, MixedGraft Occlusion, VascularUmbilical CordTissue DonorsHistocompatibilityStem Cell TransplantationTransplantation, IsogeneicWhole-Body IrradiationRisk FactorsBlood BanksProspective StudiesAntigens, CD34Hematopoietic Stem CellsInfant, NewbornTransplantation ImmunologyGraft vs Host ReactionImmunosuppressive AgentsLymphocyte ActivationBusulfanMyeloablative AgonistsSkin TransplantationImmunosuppressionHLA AntigensMice, Inbred C57BLLymphocyte Depletion