الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
Hematopoietic growth factors (HGFs) are biological agents that maintain blood production by regulating the proliferation, differentiation, and maturation of the hematopoietic stem cells, study of hematopoietic stem cells is one of the most exciting and rapidly advancing disciplines in biomedicine today. Breakthrough discoveries in both the laboratory and clinic have sharply expanded the use and supply of life-saving stem cells. Key issues for tapping the potential of hematopoietic stem cells will be finding ways to safely and efficiently expand the numbers of transplantable human HSCs in vitro or in vivo. It will also be important to gain a better understanding of the fundamentals of how immune cells work in fighting infections, in causing transplant rejection, and in graft-versus-host disease as well as master the basics of HSC differentiation. Concomitant advances in gene therapy techniques and the understanding of cellular plasticity could make HSCs one of the most powerful tools for healing. HGFs play a significant role in the production of cells belonging to all three hematopoietic cell lineages, and a reduction in any of these cell lines results in neutropenia, anemia or thrombocytopenia so recombinant HGFs are attractive adjunct to reduce morbidity from chemotherapy regimens and their use has become widespread in pediatric oncology. Hematopoietic growth factors can be classified according to type of hematopoietic cell that stimulate: a)Clooney- stimulating factors: stimulate white blood cells as G-CSF, M-CSF, GM-CSF, IL-3, - PIXY321. b)Erythropoiesis stimulating factors: stimulate RBCs production as erythropoietin. c)Thrombopoietic stimulating factors: stimulate platelet production. The mechanism of action of HGFs is through interaction with specific receptors on target cells leading to signal transduction inside the target cell leading to production of its biological activity.