Cord Blood Stem Cell TransplantationTransplantation, HomologousHematopoietic Stem Cell TransplantationGraft vs Host DiseaseTransplantation ConditioningFetal BloodHematologic NeoplasmsGraft vs Leukemia EffectGraft vs Tumor EffectLeukemiaTransplantation, AutologousBone Marrow TransplantationStem CellsSpinal CordTreatment OutcomeRetrospective StudiesRecurrenceStem Cell TransplantationHematopoietic Stem CellsAcute DiseaseSpinal Cord InjuriesTime FactorsTransplantation ChimeraSurvival RateGraft SurvivalT-LymphocytesIsoantigensLymphocyte Culture Test, MixedHistocompatibility TestingUmbilical CordTissue DonorsFollow-Up StudiesAntigens, CD34Whole-Body IrradiationHistocompatibilityBlood BanksRisk FactorsTransplantation, IsogeneicProspective StudiesInfant, NewbornBusulfanCells, CulturedLymphocyte ActivationMyeloablative AgonistsMice, Inbred C57BLPeripheral Blood Stem Cell TransplantationSkin TransplantationTransplantation ImmunologyFlow CytometryPlant StemsGraft vs Host ReactionLeukemia, Myeloid, AcuteGraft Rejection