Recombinant human stem cell factor (SCF) is homologous with recombinant rat SCF (rrSCF) and is a ligand for c-kit. We determined the influence of SCF on hematopoiesis in vitro and in vivo in baboons. In vitro, SCF alone stimulated little growth of hematopoietic colony-forming cells from baboon marrow, but did increase the number of colonies formed in response to erythropoietin (Epo), interleuki...

In order to study a previously described genetic difference manifested in stem cell kinetics of specific mouse strains, effects of this putative gene, stk, were measured on growth and expansion of stem and progenitor cell populations ex vivo. Bone marrow cells from each of two inbred mouse strains, C57BL/6J and DBA/2J, were placed into separate bioreactor cultures perfused continuously with gro...

Sublethally irradiated mice were administered with scorpion venom peptides (SVP) or with PBS in the saline control group, 3 days before and 7 consecutive days after irradiation. Hematopoietic recovery was assessed by bone marrow (BM) cell proliferation index (PI) and colony forming unit-granulocyte/macrophage (CFU-GM), spleen weight index (SI) and thymus weight index (TI), colony-forming unit-s...

We investigated how in vivo effects of single hematopoietic cytokines change if given in combination for a prolonged time. Mice were treated with every combination of recombinant human (rh) erythropoietin (EPO), rh granulocyte colony-stimulating factor (G-CSF), recombinant rat (rr) stem cell factor (SCF), and rh interleukin (IL)-11 by continuous infusion over 7 days (full factorial design with ...

The in vitro growth of early (burst-forming unit-megakaryocyte [BFU-meg]) and late (colony-forming unit-megakaryocyte [CFU-meg]) megakaryocyte progenitors was investigated in midtrimester human fetal blood and compared with adult bone marrow. Most of the experiments were performed in a serum-free fibrin-clot assay, using purified hematopoietic progenitor (CD34+) cells. High BFU-meg and CFU-meg ...

We have identified a novel regulatory erythroid kinase (REDK) that is homologous to a family of dual-specificity kinases. The yeast homolog of REDK negatively regulates cell division, suggesting a similar function for REDK, which is primarily localized in the nucleus. REDK is present in hematopoietic tissues, such as bone marrow and fetal liver, but the RNA is expressed at significant levels on...

The influence of in utero low-dose ionizing radiation exposure on murine hemopoietic embryogenesis was investigated. In vitro assays such as micro plasma-clot cultures and doublelayer soft agar cultures served as sensitive biodosimeters to determine erythropoietic and granulopoietic injuries. Day-10-5, HA/ICR, pregnant mice were irradiated with 0, 50, 100, 150,200, or 300 rads, and day-14-5 fet...

Although it has been demonstrated that lymphokine-activated killer (LAK) cells kill tumor cells in a selective way without being toxic to a variety of normal cells, contradictory results exist about the possible toxicity of natural killer (NK) and LAK cells for hematopoietic progenitor cells. Therefore, the cytolytic activity and growth inhibitory effects of LAK cells on normal bone marrow prog...

BACKGROUND Use of protective footwear before entering the intensive care units is enforced with the assumption that it lowers the incidence of bacterial floor colonization. The present study was carried out to find the efficacy of protective footwear on bacterial floor colonization. METHODS The study was carried out in the intensive care unit of a tertiary care hospital. The study was divided...

We examined the effects of activin A on the proliferation and differentiation of immature hematopoietic progenitors prepared from peripheral blood (PB) using methylcellulose and liquid-suspension culture. In a kinetic analysis, colony formation by PB granulocyte-macrophage colony-forming unit (CFU-GM) was delayed in a dose-dependent manner by the addition of activin A only when stimulated with ...