Cord Blood Stem Cell TransplantationFetal BloodGraft vs Host DiseaseTransplantation ConditioningHistocompatibility TestingUnrelated DonorsHematologic NeoplasmsUmbilical CordBlood BanksTransplantation, HomologousHematopoietic Stem Cell TransplantationTissue DonorsTransplantation ChimeraGraft SurvivalMyeloablative AgonistsHistocompatibilityTransplantsChimerismHematologic DiseasesVolvariellaHLA AntigensLeukemiaVidarabineBlood DonorsTreatment OutcomeAnemia, Aplastic