Study of Parathyroid Hormone Following Sequential Cord Blood Transplantation From an Unrelated Donor

Inclusion Criteria: * One of the following diagnoses: 1. Chronic myelogenous leukemia (CML) accelerated phase or second stable phase; individuals in the first chronic phase are eligible if they have resistance to imatinib 2. Myelodysplasia 3. Aplastic anemia that is not responding to immunosuppressive therapy 4. Myelofibrosis, either primary or secondary to polycythemia vera 5. Relapsed lymphoma or Hodgkin's disease 6. Stage III/IV chronic lymphocytic leukemia (CLL), relapsed after or refractory to at least one fludarabine containing regimen 7. Acute myelogenous leukemia (AML) or acute lymphoblastic leukemia (ALL) in complete remission (CR) 2 or greater, or CR 1 with high risk features * No prior autologous stem cell transplant * Eastern Cooperative Oncology Group (ECOG) performance status of less than 2 * Lack of 6/6 or 5/6 matched related donor OR lack of 10/10 matched unrelated donor OR no available donor in the appropriate time frame to perform a potentially curative stem cell transplant * Diffusing capacity of the lung for carbon monoxide (DLCO) greater than 50% of predicted value * Left ventricular ejection fraction (LVEF) greater than 50% of predicted value * Calcium levels less than 10.5 mg/dl * Phosphate levels greater than 1.6 mg/dl Exclusion Criteria: * Heart disease, as determined by symptomatic congestive heart failure, radionuclide ventriculogram (RVG), or echocardiogram-determined LVEF of less than 50%, active angina pectoris, or uncontrolled high blood pressure * Pulmonary disease, as determined by severe chronic obstructive lung disease, symptomatic restrictive lung disease, or corrected DLCO of less than 50% of predicted value * Kidney disease, as determined by serum creatinine levels greater than 2.0 mg/dl * Liver disease, as determined by serum bilirubin levels greater than 2.0 mg/dl (except in the case of Gilbert's syndrome or hemolytic anemia in which the bilirubin can be elevated greater than 2.0mg/dl), SGOT or SGPT greater than 3 times the upper limit of normal * Neurologic disease, as determined by symptomatic leukoencephalopathy, active central nervous system (CNS) cancer, or other neuropsychiatric abnormalities that may prevent transplantation (previous CNS cancer and presently in CR is acceptable) * HIV antibodies * Uncontrolled infection * Pregnant or breastfeeding