Effect of cytokine treatment (granulocyte colony-stimulating factor and stem cell factor) on hematopoiesis and the circulating pool of hematopoietic stem cells in mice.

The mobilization of hematopoietic stem cells (HSCs) into the peripheral blood of mice was induced by recombinant human granulocyte colony-stimulating factor (rhG-CSF) (250 microgram/kg/d) alone or combined with recombinant rat stem cell factor (rrSCF) (34 microgram/kg/d), injected subcutaneously (s.c.) once a day for 10 and 17 days.

[Study of hematopoietic stem cell pool maintenance in successive transplantations using a quantitative method of assessment].

The ability of transplantable hemopoietic stem cells (HSC) to maintain their pool was studied using successive bone marrow transplantations with quantitative evaluation of hemopoiesis restoring units (HRU) in each transfer. The number of injected HRU increased (3.6-48.

[Hematopoietic stem cells in mice during embryonic development preceding the establishment of liver hematopoiesis].

We studied the time course of appearance of CFUs (7-8 days old) in embryos of (C57B1/6 x CBA)F1 mice from the 8th day of embryonic development. Significant amounts of CFUs could be detected from the 10th day of development, initially in the body of the embryo from the stage of 30-33 pairs of somites, then in the yolk sac and still later, from the stage of about 40 pairs of somites, in liver anlage. CFUs could not be reliably detected until the 9th day of development either in the embryo itself or in the yolk sac.

[Quantitative determination of transplantable hemopoietic stem cells by limiting dilution method].

The concentration of hemopoiesis restoring units (HRU) in bone marrow of mice was assayed by using the limiting dilution method in transplantation to lethally irradiated mice. 7 to 12.7 HRU were found in 10(6) bone marrow cells of CBF1 mice and 19.