Chemotherapy Toxicity Reduction Via Urea Cycle Support

Inclusion Criteria: * We propose to study 144 patients undergoing allogeneic bone marrow transplantation or peripheral blood stem cell transplant over a 4 year period. * Patients of either sex and of any race or ethnic origin, older than age greater than or equal to13, and admitted to the Myelosuppression Unit (MSU) of Vanderbilt University Hospital or the VA Hospital to undergo bone marrow transplantation will be recruited for this study. Exclusion Criteria: * Patients will be excluded if pregnant (unlikely) or if informed consent cannot be obtained. * Because of the intrinsic toxicity of the treatment regimens, BMT is not usually offered to patients with severe underlying derangements in organ function. Nevertheless, other exclusions that will prevent entry of patients into the study include advanced renal or hepatic failure (serum creatinine \> 6mg/dl, serum bilirubin \>3.5 mg/dl), moribund patients, and patients whose primary physician is not committed to full support of the patient (i.e. "Do Not Resuscitate"). * Other exclusions will include patients enrolled in another experimental (interventional) protocol aimed at reducing transplant related complications during BMT, patients testing positive for HIV, those who have had previous BMT, and patients actively bleeding at the time of initiation of induction therapy. We will not exclude patients undergoing newer regimens of cytotoxic chemotherapy.