We have evaluated the effect of filgrastim on proliferation and differentiation activity of granulopoietic cells in mice pretreated with methotrexate. Filgrastim was injected daily, from day 8 to 28 after cytotoxic agent administration. The granulopoiesis changes were measured by assessment of GM-CFU cells content, marrow and spleen granuloid cells pool as well as circulating neutrophils. In MT...

It was demonstrated previously that mice undergoing an inflammatory reaction induced by subcutaneous (SC) implantation of copper rods, produce humoral factors that initially enhance, but subsequently inhibit, diffusion chamber (DC) granulopoiesis. This provided evidence that granulopoiesis is under the control of both humoral stimulators and inhibitors. In order to test the granulopoietic regul...

Granulocyte colony-stimulating factor (G-CSF) is essential for the host response to bacterial infection by controlling neutrophil production in the bone marrow. The G-CSF receptor (G-CSFR) activates the Jak/STAT pathway, although little is understood about how these signals regulate basal and stress-induced granulopoiesis. We examined STAT3 function in granulocytes using a bone marrow condition...

Three different methods of measuring the proliferative capacity of transplanted mouse bone marrow were used to study the effects of preirradiation of the recipient. Recipient mice were exposed to 700 R and given graded numbers of syngeneic bone marrow. 7 days were allowed for proliferation of these cells, and then the granulocytic or erythrocytic progeny was measured. The former was determined ...

Human lactoferrin (LF) has been reported to inhibit in vitro granulopoiesis by means of decreasing colony-stimulating activity production by monocytes. We performed a series of experiments to determine if the reported experimental results could be replicated using highly purified murine LF and murine target cells. Three different types of experiments were performed. (1) Medium was conditioned b...

Neutropenia, frequently a side effect of chemo- and radiotherapy, increases susceptibility to microbial infections and is a life-threatening condition. For realistically predicting drug treatment effects on granulopoiesis, we have constructed a new mathematical model of granulopoiesis in the bone marrow and in the peripheral blood, featuring cell cycle phase transition and detailed granulocyte-...

Mice lacking granulocyte colony-stimulating factor (G-CSF) were generated by targeted disruption of the G-CSF gene in embryonal stem cells. G-CSF-deficient mice (genotype G-CSF-/-) are viable, fertile, and superficially healthy, but have a chronic neutropenia. Peripheral blood neutrophil levels were 20% to 30% of wild-type mice (genotype G-CSF+/+) and mice heterozygous for the null mutation had...

The JAK2V617F mutation is present in most patients with polycythemia vera (PV) and in some patients with essential thrombocythemia (ET) and myeloid metaplasia/myelofibrosis (MMM). We sought to investigate the relationship between granulocyte clonality and JAK2V617F allelic ratio. A total of 168 of 190 female patients were informative for a clonality assay at the HUMARA locus; 80% of MMM, 75% of...

The inhibitory effect by hairy cell conditioned medium (HCCM) on the growth of granulocyte and erythrocyte colony forming cells was studied in vitro. The percent inhibition of CFU-C formation by HCCM from four hairy cell leukemia (HCL) patients ranged from 36% to 76%, while no inhibition was observed with conditioned medium (CM) obtained from three B-cell chronic lymphocytic leukemia (B-CLL) pa...