Growth factors hematopoietic

IL-6 CD4" T-lymphocytes (TH2 subset). T- and B-lymphocytic growth factor, hematopoietic growth... 

Vascular endothelial growth factor. This cytokine is a non-hematopoietic growth factor. Hematopoietic growth factors, such as erythropoietin (EPO), are also regarded as cytokines they are all polypeptides and may... 

Cytokines, eg, interferons, interleukins, tumor necrosis factor (TNF), and certain growth factors, could have antitumor activity directiy, or may modulate cellular mechanisms of antitumor activity (2). Cytokines may be used to influence the proliferation and differentiation of T-ceUs, B-ceUs, macrophage—monocyte, myeloid, or other hematopoietic cells. Alternatively, the induction of interferon release may represent an important approach for synthetic—medicinal chemistry, to search for effective antiinflammatory and antifibrotic agents. Inducers of interferon release may also be useful for lepromatous leprosy and chronic granulomatous disease. The potential cytokine and cytokine-related therapeutic approaches to treatment of disease are summarized in Table 4. A combination of cytokines is a feasible modaUty for treatment of immunologically related diseases however, there are dangers inherent in such an approach, as shown by the induction of lethal disserninated intravascular coagulation in mice adrninistered TNF-a and IFN-y. 

Cytokine receptors are a group of structurally related receptors, which couple to the JAK-STAT pathway. Cytokine receptors function as homodimers or heterooligomers. They are divided into two main subclasses, class I, which contains receptors for a variety of hematopoietic growth factors and interleukins and class II, which contains receptors for interferons and interleukins 10, 20/24 and 22. 

Inhibition of hematopoietic growth factors Imatinib (Glivec ) is applied to treat chronic myeloid leukemia in Philadelphia-chromosome positive patients. In these patients, translocation of parts of chromosomes 9 and 22 results in the expression of a fusion protein with increased tyrosine kinase activity, called Bcr-Abl. Imatinib is a small Mw inhibitor selective for the tyrosine kinase activity of Bcr-Abl. Thereby, it inhibits the Bcr-Abl induced cell cycle progression and the uncontrolled proliferation of tumor cells. 

Hematopoietic (blood) cells transport oxygen and carbon dioxide, contribute to host immunity, and facilitate blood clotting [1], A complex, interrelated, and multistep process, called hematopoiesis, controls the production as well as the development of specific marrow cells from immature precursor cells to functional mature blood cells. This well-regulated process also allows for replacement of cells lost through daily physiologic activities. The proliferation of precursor cells, the maturation of these into mature cells, and the survival of hematopoietic cells require the presence of specific growth factors. 

All mature blood cells arise from primitive hematopoietic cells in the bone marrow, the pluripotent stem cells. Approximately 0.1% of the nucleated cells of the bone marrow are pluripotent stem cells and approximately 5% of these cells may be actively cycling at any one time. The stem cell pool maintains itself through a process of asymmetrical cell division when a stem cell divides, one daughter cell remains a stem cell and the other becomes a committed colony-forming cell (CFC). The proliferation and differentiation of CFCs are controlled by hematopoietic growth factors. The hematopoietic growth factors stimulate cell division, differentiation and maturation, and convert the dividing cells into a population of terminally differentiated functional cells. 

Hematopoietic Growth Factors. Figure 1 Schema of hematopoiesis, including some of the growth factors that influence the production of blood cells. 

SCF (recombinant product ancestim) is an early-acting hematopoietic growth factor that stimulates the proliferation of primitive hematopoietic and nonhema-topoietic cells [7]. In vitro, SCF has minimal effect on hematopoietic and nonhematopoietic progenitor cells, but it synergistically increases the activity of other hematopoietic growth factors, such as G-CSF, GM-CSF, and EPO. SCF stimulates the generation of dendritic cells in vitro and mast cells in vivo. 

The use of recombinant hematopoietic growth factors (i.e., the commercially available forms of the native products) has been evaluated in many disorders affecting all types of blood cells. Recombinant human hematopoietic growth factors are identified as rHu. Not all uses discussed have received regulatory approval in all countries. 

When hematopoietic growth factors are used clinically, they can be associated with adverse effects. Very often patients who require hematopoietic growth factors are quite ill with their disease (i.e., cancer or kidney failure) or from their treatment (i.e., chemotherapy) and it is difficult to determine if a recombinant growth factor is responsible for a given side effect. Both rHuG-CSF and rHuGM-CSF are associated with mild-to-moderate... 

The recombinant hematopoietic growth factors have had a significant impact on the treatment of cancer, including prevention of serious infections and anemia. 

A cytokine, secreted by TH2-cells and mast cells, stimulates B-cell growth, acts as hematopoietic factor for growth factor eosinophils, and extends the life span of eosinophils. 

Anticoagulants Hematopoietic Growth Factors Antiplatelet Drugs... 

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