The effects of recombinant human macrophage colony-stimulating factor (rhCSF-1) in long-term marrow cultures (LTMC) established from normal bone marrow cells were examined. When added during the first 3 weeks of culture (every second day, at 15 ng/mL), rhCSF-1 strongly inhibited the growth of all hematopoietic progenitors analyzed (colony-forming unit-MIX [CFU-MIX], CFU-granulocyte macrophage [...

Thrombopoietin (TPO) is a hematopoietic growth factor that stimulates megakaryocytopoiesis and platelet production in vivo and promotes the development of identifiable megakaryocytes in vitro. We have developed a murine monoclonal antibody, BAH-1, raised against human megakaryocytic cells, which specifically recognizes the c-Mpl receptor and shows agonist activity by stimulating megakaryocytopo...

The WT1 tumor-suppressor gene is expressed by many forms of acute myeloid leukemia. Inhibition of this expression can lead to the differentiation and reduced growth of leukemia cells and cell lines, suggesting that WT1 participates in regulating the proliferation of leukemic cells. However, the role of WT1 in normal hematopoiesis is not well understood. To investigate this question, we have use...

Angiotensin I-converting enzyme (ACE) inhibitors can affect hematopoiesis by several mechanisms including inhibition of angiotensin II formation and increasing plasma concentrations of AcSDKP (acetyl-N-Ser-Asp-Lys-Pro), an ACE substrate and a negative regulator of hematopoiesis. We tested whether ACE inhibition could decrease the hematopoietic toxicity of lethal or sublethal irradiation protoco...

Purified recombinant (r) macrophage inflammatory proteins (MIPs) 1 alpha, 1 beta, and 2 were assessed for effects on murine (mu) and human (hu) marrow colony-forming unit-granulocyte-macrophage (CFU-GM) and burst-forming unit-erythroid (BFU-E) colonies. Recombinant MIP-1 alpha, -1 beta, and -2 enhanced muCFU-GM colonies above that stimulated with 10 to 100 U natural mu macrophage-colony-stimula...

Chronic myelogenous leukemia (CML) is a clonal disorder of the hematopoietic stem cell characterized by a chimeric BCR/ABL gene giving rise to a 210-kD fusion protein with dysregulated tyrosine kinase activity. We investigated the effect of genistein, a protein tyrosine kinase inhibitor, on the in vitro growth of CML and normal marrow-derived multi-potent (colony-forming unit-mix [CFU-Mix]), er...

BACKGROUND To describe Rituximab associated neutropenia (RAN), and to explore its underlying mechanism. CASE REPORT We describe three patients with RAN. The effect of patient's plasma on colony forming unit, Granulocyte-Monocyte (CFU-GM) was measured by the addition of plasma to the culture of a healthy bone-marrow. Repeated tests were performed after recovery of white count. In the leukopeni...

Nitric oxide (NO) is a reactive molecule with numerous physiologic and pathophysiologic roles affecting the nervous, cardiovascular, and immune systems. In previous work, we have demonstrated that NO inhibits the growth and induces the monocytic differentiation of cells of the HL-60 cell line. We have also demonstrated that NO inhibits the growth of acute nonlymphocytic leukemia cells freshly i...

Hematopoietic stem cell activity in inbred NZB and NZC mice has been determined by transplantation and endogenous spleen colony assays. Whereas NZB mice show normal colony-forming unit (CFU) activity in the transplantation assay, they show markedly elevated endogenous CFU. NZC mice also show this markedly elevated endogenous CFU activity, but in the transplantation assay show only about 5-10% o...

Bone marrow cells in suspension were separated into a number of fractions on the basis of cell size by sedimentation at unit gravity through gradients of fetal calf serum. The colony forming units (CFU) from the various fractions were tested for their self-renewal capacity using a double transplantation technique. The results indicate that the CFU in the fractions containing slowly sedimenting ...