An improved plasma culture system is described for the production of erythrocytic colonies by mammalian adult hemopoietic cells in vitro under the influence of erythropoietin. The concentration of fetal calf serum in the medium used for dilution of the cells was critical for erythrocytic colony formation when low numbers of cells were plated. Optimal concentrations were found for plasma, fetal ...

Pluripotent hemopoietic stem cells (PHSC) 1 are operationally defined by their ability to generate all of the cellular components of the lymphohemopoietic system while retaining the capacity for extensive self-replication. The existence of PHSC has been documented by the in vivo spleen colony-forming unit (CFU-S) assay (1) and by cell tracer studies (2, 3). The major obstacles to the isolation ...

A VARIETY OF METHODS have been used to investigate the properties of the stem cell#{176} compartment.’#{176} The spleen colony method introduced by Till and McCullocW measures the production of hematopoietic colonies after injection of syngeneic bone marrow into irradiated recipient mice. These colonies appear to be the progeny of single cells’0 which are able to differentiate to form either gr...

We investigated the mechanism by which granulocyte-macrophage colony-stimulating factor (GM-CSF) lowers plasma cholesterol levels. Recombinant human GM-CSF (rhGM-CSF) was administered to normal and Watanabe heritable hyperlipidemic (WHHL) rabbits. Treatment with rhGM-CSF reduced the levels of cholesterol and triglyceride in these animals. In vitro colony assay for hematopoietic progenitors indi...

A VARIETY OF METHODS have been used to investigate the properties of the stem cell#{176} compartment.’#{176} The spleen colony method introduced by Till and McCullocW measures the production of hematopoietic colonies after injection of syngeneic bone marrow into irradiated recipient mice. These colonies appear to be the progeny of single cells’0 which are able to differentiate to form either gr...

Spleen cell production of granulocyte-macrophage colony stimulating activity (CSA) and colony forming capacity (CFU-GM) from 59 patients with Hodgkin's and non-Hodgkin's lymphoma, acute (AML) and chronic myeloid leukemia (CML), and control subjects was quantified to evaluate local cellular potential for modulating splenic granulocytopoiesis. Mononuclear spleen cell conditioned media stimulated ...

Injection of lipopolysaccharide (LPS) into mice was followed by a rapid elevation of colony-stimulating factor (CSF) in the serum. A second, challenging injection of LPS given 3 to 4 days later failed to induce elevated levels of CSF in the serum. Such mice tolerant to LPS were used as an experimental tool to identify the CSF-producing cells which respond to LPS. We observed that generation of ...