Cell-free extracts from human polymorphonuclear neutrophils (PMN) inhibited rebound granulopoiesis in the bone marrow and spleen of mice pretreated with cyclophosphamide to remove endogenous PMN. Absolute numbers of granulocytemonocyte progenitor cells (CFU-C) and net endogenous colony-stimulating activity (CSA) production were found to be increased 3 days after cyclophosphamide in the bone mar...

Committed progenitor cells and primitive stem cells mediate early and sustained engraftment, respectively, after lethal irradiation and stem cell transplantation. Peripheral blood stem cells (PBSC) from unstimulated mice are deficient in both cell types. To study techniques to mobilize both progenitor cells and primitive stem cells from the marrow to the blood, we collected peripheral blood fro...

Monoacetyldiglycerides purified from deer antler, and identical synthetic compounds, have been shown to stimulate hematopoiesis. In the present study, we synthesized eight monoacetyldiglycerides, one of which, 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (3), was structurally identical to one of the naturally occurring monoacetyldiglycerides and showed the most potent stimulation of hematopoie...

The murine myeloma MOPC-315 secretes a paraprotein which binds dinitrophenylated compounds. Maturational subsets which mimic normal B-cell differentiation were shown to exist within this monoclonal neoplasm. The maturational subsets were defined by an in vivo stem cell activity (plasmacytoma colony-forming unit-spleen), DNA synthesis ([3H]thymidine incorporation), membrane-bound paraprotein, an...

The effects of a single dose (150 mg/kg) of 5-fluorouracil on mature erythroid and erythropoietic and multipotential in vitro precursor populations in the bone marrow and spleen and circulating biologically (erythroid colony forming unit [CFU-E] assay) and immunologically active (enzyme-linked immunosorbent assay) erythropoietin (Epo) are described. All mature erythroid (reticulocytes, erythroc...

Committed progenitor cells and primitive stem cells mediate early and sustained engraftment, respectively, after lethal irradiation and stem cell transplantation. Peripheral blood stem cells (PBSC) from unstimulated mice are deficient in both cell types. To study techniques to mobilize both progenitor cells and primitive stem cells from the marrow to the blood, we collected peripheral blood fro...

The murine myeloma MOPC-315 secretes a paraprotein which binds dinitrophenylated compounds. Maturational sub sets which mimic normal B-cell differentiation were shown to exist within this monoclonal neoplasm. The maturational sub sets were defined by an in vivo stem cell activity (plasmacytoma colony-forming unit-spleen), DMA synthesis ([3H]thymidine in corporation), membrane-bound paraprotein,...

the relationship between the way in which normal hemopoietic stem cells respond to irradiation alone or in the presence of bleomycin sulfate (blm-s) and actinomycin 0 (act-d) was investigated. single doses of blm-s at 0.3 mg/kg and act-o at 0.10 mg/kg body weight were injected intravenously 1-6 hours prior to whole body irradiation and treatment was repeated twice more with time intervals. when...

Antitumor activity of spleen cells from BALB/c mice bearing RL male 1 lymphoma was studied. In the Winn assay spleen cells of the tumor-bearing mice inhibited the growth of RL male 1 lymphoma. This antitumor activity of spleen cells was not detected by the in vitro cell-mediated cytotoxicity assay (4-h 51Cr release assay). The effector cells in spleen cells were T-cells which manifested asialo ...

We have developed a limiting-dilution assay of long-term repopulating hematopoietic stem cells in the mouse using a miniturized stroma-dependent bone marrow culture assay in vitro. The cells were overlaid on irradiated stromal layers in microtiter wells in a range of concentrations, and frequencies of cobblestone area-forming cells (CAFC) were calculated by employing Poisson statistics. The pro...