Cord Blood Stem Cell TransplantationFetal BloodHematopoietic Stem CellsHematopoietic Stem Cell TransplantationUmbilical CordTransplantation, HomologousAntigens, CD34Graft vs Host DiseaseTransplantation ConditioningHematologic NeoplasmsBlood BanksSpinal CordGraft vs Leukemia EffectStem CellsInfant, NewbornUmbilical VeinsLeukemiaUmbilical ArteriesTransplantation, AutologousBone Marrow TransplantationPregnancySpinal Cord InjuriesGraft vs Tumor EffectCells, CulturedTreatment OutcomeHematopoiesisCell DifferentiationHistocompatibility TestingStem Cell TransplantationTransplantation ChimeraRetrospective StudiesGraft SurvivalBone Marrow CellsColony-Forming Units AssayTime FactorsCell SeparationFlow CytometryCell LineageRecurrenceTissue DonorsMice, SCIDAntigens, CDMesenchymal Stromal CellsMaternal-Fetal ExchangeImmunophenotypingT-LymphocytesAcute DiseaseHematopoietic Stem Cell MobilizationMice, Inbred NODCell Culture TechniquesWhole-Body IrradiationMyeloablative AgonistsHistocompatibilityBlood PreservationAntigens, CD38ChimerismSurvival RateHematologic DiseasesMice, Inbred C57BLHLA AntigensStem Cell FactorBlood CellsCell ProliferationBusulfanCoculture TechniquesDonor SelectionUnrelated DonorsBlood Cell CountFetal Stem CellsFetusBone MarrowFollow-Up StudiesADP-ribosyl CyclasePlacentaProspective StudiesAnemia, AplasticHernia, UmbilicalIsoantigensGestational AgeBlood Transfusion, AutologousLymphocyte Culture Test, MixedVidarabineRisk FactorsLeukemia, Myeloid, AcuteAllograftsLymphocyte ActivationAntigens, CD45Nuchal CordLeukocytes, MononuclearTransplantation, HeterologousBlood DonorsSiblingsLymphocytesUrachal CystCell DivisionTransplantation, IsogeneicNAD+ NucleosidaseImmunosuppressive AgentsKiller Cells, NaturalPrecursor Cell Lymphoblastic Leukemia-Lymphoma