Bone marrow transplantation for leukemia following a new busulfan and cyclophosphamide regimen

Busulfan 16 mg/kg and cyclophosphamide 120 mg/kg were used as conditioning prior to allogeneic marrow transplantation in 50 adult patients with acute nonlymphocytic leukemia (ANLL), acute lymphocytic leukemia (ALL), and chronic myelogenous leukemia (CML). A standard risk group of 20 patients included those with acute leukemia in remission and CML in chronic phase. A high-risk group of 30 patients included individuals with refractory acute leukemia, acute leukemia in relapse, acute leukemia following preleukemia, and CML in accelerated and blastic phase. Complete remission and sustained complete engraftment were achieved in all evaluable patients. The duration of aplasia was remarkably short (median of 8 days), resulting in a low infection rate during the period of neutropenia, a reduced need for blood product support, and a short length of hospital stay. Three-year actuarial relapse-free survival in both standard-risk (88.9% +/- 10.5%) and high- risk (50.5% +/- 9.6%) groups compares favorably with that reported with total body irradiation (TBI) containing regimens.     

Interferon-alpha alters spectrin organization in normal and leukemic human B lymphocytes

Interferon-alpha (IFN-alpha) regulates the growth, differentiation, and recirculation of normal and malignant B lymphocytes. In this report we examine the effects of IFN-alpha on the distribution of the cytoskeletal protein spectrin in peripheral blood B lymphocytes from normal donors and patients diagnosed with chronic lymphocytic leukemia (CLL) and hairy cell leukemia (HCL). Exposure of normal and leukemic B cells to IFN-alpha in vitro was shown by immunofluorescence microscopy to cause a dose-dependent increase in the percentage of cells containing discrete focal accumulations of spectrin, ie, a single large aggregate or cap-like structure near the plasma membrane. Although the magnitude of this effect was variable among individual patient samples, in some experiments IFN-alpha induced a fourfold increase in the percentage of leukemic B cells exhibiting focal accumulations of spectrin. Spectrin reorganization induced by IFN-alpha was abrogated by the protein synthesis inhibitor cycloheximide. In addition, IFN-alpha increased the total cellular content of spectrin in B-CLL cells by approximately twofold to fourfold. Finally, a role for protein kinase C in mediating the effects of IFN-alpha on spectrin's organization is implicated by studies in which calphostin C inhibited the IFN-induced focal accumulation of spectrin. Taken together, these studies suggest that the immunomodulatory activities of IFN-alpha in normal and malignant B cells involve a change in the organization of the spectrin- based cytoskeleton.     

A comparative study of the iron-clearing properties of desferrithiocin analogues with desferrioxamine B in a Cebus monkey model

A comparative study of the iron-clearing properties of subcutaneously administered desferrioxamine B (DFO) with those of orally administered desferrithiocin sodium salt (1), desmethyl desferrithiocin (2), desazadesmethyl desferrithiocin sodium salt (3), desazadesmethyl desferrithiocin pivaloyloxymethyl ester (4), and desazadesmethyl-5,5- dimethyl desferrithiocin (5) in an iron-loaded Cebus monkey model and a non-iron overloaded bile duct-cannulated rat model is presented. All six drugs, which performed well in rodent studies, demonstrated increased efficiency in the Cebus monkey model. When administered to rodents at a daily dosage of 384 mumol/kg over a period of 10 days, drug 1 demonstrated severe renal toxicity. whereas drugs 3, 4, and 5 exhibited severe gastrointestinal (GI) toxicity. Under the same experimental protocol, drug 2 did not show significant toxic side effects. In addition, to further evaluate the iron-clearing properties of analogue 2, a dose-response study was performed in the primates that showed that iron excretion increased in a dose-dependent fashion.