platelet-derived growth factor
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an agent or element that contributes to the production of a result.
factor I see coagulation factors.
factor II see coagulation factors.
factor III see coagulation factors.
factor IV see coagulation factors.
factor V see coagulation factors.
factor VI see coagulation factors.
factor VII see coagulation factors.
factor VIII see coagulation factors.
factor IX see coagulation factors.
factor X see coagulation factors.
factor XI see coagulation factors.
factor XII see coagulation factors.
factor XIII see coagulation factors.
angiogenesis factor a substance that causes the growth of new blood vessels, found in tissues with high metabolic requirements such as cancers and the retina. It is also released by hypoxic macrophages at the edges or outer surface of a wound and initiates revascularization in wound healing.
antihemophilic factor (AHF)
2. a preparation of factor VIII administered intravenously for the prevention or treatment of hemorrhage in patients with hemophilia A and the treatment of von Willebrand disease, hypofibrinogenemia, and coagulation factor XIII deficiency. Included are preparations derived from human plasma (antihemophilic factor, cryoprecipitated antihemophilic factor) or porcine plasma (antihemophilic factor [porcine]) and those produced by recombinant technology antihemophilic factor [recombinant]).
antihemorrhagic factor vitamin K.
antinuclear factor (ANF) antinuclear antibody.
antirachitic factor vitamin D.
atrial natriuretic factor (ANF) a hormone produced in the cardiac atrium; an inhibitor of renin secretion and thus of the production of angiotensin, and a stimulator of aldosterone release. Its effect is increased excretion of water and sodium and a lowering of blood pressure.
factor B a complement component that participates in the alternative complement pathway.
blastogenic factor lymphocyte-transforming factor.
carative f's in the theory of human caring, a set of ten factors that offer a descriptive topology of interventions including (1) a humanistic-altruistic system of values; (2) faith-hope; (3) sensitivity to self and others; (4) a helping-trusting, human care relationship; (5) the expression of positive and negative feelings; (6) a creative problem-solving caring process; (7) transpersonal teaching and learning; (8) a supportive, protective, and/or corrective mental, physical, societal, and spiritual environment; (9) human needs assistance; and (10) existential-phenomenological-spiritual forces.
citrovorum factor folinic acid.
clotting f's coagulation factors.
C3 nephritic factor (C3 NeF) an autoantibody that stabilizes the alternative complement pathway C3 convertase, preventing its inactivation by factor h, resulting in complete consumption of plasma C3; it is found in the serum of many patients with type II membranoproliferative glomerulonephritis.
coagulation f's see coagulation factors.
colony-stimulating factor (CSF) any of a number of glycoproteins responsible for the proliferation, differentiation, and functional activation of hematopoietic progenitor cells; specific factors are named for the cell lines that they stimulate. Used to promote bone marrow proliferation in aplastic anemia, following cytotoxic chemotherapy, or following bone marrow transplantation. Types include granulocyte, granulocyte-macrophage, and macrophage colony-stimulating factors.
factor D a factor that when activated serves as a serine esterase in the alternative complement pathway.
decay accelerating factor (DAF) a protein of most blood as well as endothelial and epithelial cells, CD55 (see CD antigen); it protects the cell membranes from attack by autologous complement.
endothelial-derived relaxant factor (endothelial-derived relaxing factor) (endothelium-derived relaxing factor (EDRF)) nitric oxide.
extrinsic factor cyanocobalamin.
F factor (fertility factor) F plasmid.
Fitzgerald factor high-molecular-weight kininogen.
Fletcher factor prekallikrein.
granulocyte colony-stimulating factor (G-CSF) a colony-stimulating factor that stimulates production of neutrophils from precursor cells.
granulocyte-macrophage colony-stimulating factor (GM-CSF) a colony-stimulating factor that binds to stem cells and most myelocytes and stimulates their differentiation into granulocytes and macrophages.
growth factor any substance that promotes skeletal or somatic growth; usually a mineral, hormone, or vitamin.
factor H a complement system regulatory protein that inhibits the alternative pathway of complement activation.
hematopoietic growth f's a group of substances with the ability to support hematopoietic colony formation in vitro, including erythropoietin, interleukin-3, and colony-stimulating factors. All except erythropoietin stimulate mature cells, have overlapping capabilities to affect progenitor cells of several blood cell lines, and also affect cells outside the hematopoietic system.
histamine-releasing factor (HRF) a lymphokine, believed to be produced by macrophages and B lymphocytes, that induces the release of histamine by IgE-bound basophils. It occurs in late phase allergic reaction, six or more hours after contact with the antigen, in sensitive individuals.
homologous restriction factor (HRF) a regulatory protein that binds to the membrane attack complex in autologous cells, inhibiting the final stages of complement activation.
factor I a plasma enzyme that regulates both classical and alternative pathways of complement activation by inactivating their C3 convertases.
immunoglobulin-binding factor (IBF) a lymphokine having the ability to bind IgG complexed with antigen and prevent complement activation.
insulinlike growth f's (IGF) insulinlike substances in serum that do not react with insulin antibodies; they are growth hormone–dependent and possess all the growth-promoting properties of the somatomedins.
intensification factor in radiology, the comparative increase in light transmission when films are exposed in the presence of intensifying screens compared to that in the absence of screens.
intrinsic factor a glycoprotein secreted by the parietal cells of the gastric glands, necessary for the absorption of cyanocobalamin (vitamin B12). Its absence results in pernicious anemia.
LE factor an immunoglobulin that reacts with leukocyte nuclei, found in the serum in systemic lupus erythematosus.
lymph node permeability factor (LNPF) a substance from normal lymph nodes that produces vascular permeability.
lymphocyte mitogenic factor (LMF) (lymphocyte-transforming factor) a substance that is released by lymphocytes stimulated by specific antigen and causes nonstimulated lymphocytes to undergo blast transformation and cell division; called also blastogenic factor.
macrophage-activating factor (MAF) interferon-α.
macrophage colony-stimulating factor (M-CSF) a colony-stimulating factor secreted by macrophages, stimulated endothelial cells, and most tissues, that stimulates the production of macrophages from precursor cells and maintains the viability of mature macrophages in vitro.
macrophage chemotactic factor (MCF) a lymphokine that attracts macrophages to the invasion site.
macrophage-derived growth factor a substance released by macrophages below the surface of a wound that induces the proliferation of fibroblasts.
macrophage inhibition factor (macrophage inhibitory factor) migration inhibitory factor.
migration inhibition factor (migration inhibitory factor) a lymphokine that inhibits macrophage migration.
minification factor in radiology, the gain in light achieved by a reduction in size of the output phosphor from the input phosphor size.
osteoclast-activating factor (OAF) a lymphokine that stimulates bone resorption; it may be involved in the bone resorption associated with multiple myeloma and other hematologic neoplasms or inflammatory disorders such as rheumatoid arthritis and periodontal disease.
factor P properdin.
platelet f's see platelet factors.
platelet-activating factor (PAF) a substance released by basophils and mast cells in immediate hypersensitivity reactions, and by macrophages and neutrophils in other inflammatory reactions; it leads to bronchoconstriction, platelet aggregation, and release of vasoactive substances from platelets.
platelet-derived growth factor a substance contained in platelets and capable of inducing proliferation of vascular endothelial cells, vascular smooth muscle cells, fibroblasts, and glial cells; its action contributes to the repair of damaged vascular walls.
R factor R plasmid.
releasing f's factors elaborated in one structure (as in the hypothalamus) that effect the release of hormones from another structure (as from the anterior pituitary gland), including corticotropin-releasing factor, melanocyte-stimulating hormone–releasing factor, and prolactin-releasing factor. Applied to substances of unknown chemical structure, while substances of established chemical identity are called releasing hormones.
resistance factor R f.
Rh factor a type of agglutinogen found on some erythrocytes; see also rh factor.
rheumatoid factor (RF) antibodies directed against antigenic determinants on IgG molecules, found in the serum of about 80 per cent of patients with classic or definite rheumatoid arthritis; but in only about 20 per cent of patients with juvenile rheumatoid arthritis; rheumatoid factors may be IgM, IgG, or IgA antibodies, although serologic tests measure only IgM. Rheumatoid factors also occur in other connective tissue diseases and infectious diseases.
risk factor an agent or situation that is known to make an individual or population more susceptible to the development of a specific negative condition.
risk factor (omaha) an environmental, psychosocial, or physiologic event or health related behavior that increases the client's exposure or vulnerability to the development of a client problem; the nurse's knowledge base of risk factors is used to identify potential problem modifiers in the Problem Classification scheme of the omaha system.
sun protection factor (SPF) a numerical rating of the amount of protection afforded by a sunscreen; the higher the number, the more protection is provided.
tissue factor factor III, one of the coagulation factors.
transfer factor (TF) a factor occurring in sensitized lymphocytes that can transfer delayed hypersensitivity to a formerly nonreactive individual; see also transfer factor.
tumor necrosis factor (TNF) either of two lymphokines produced primarily by cells of the immune system, capable of causing in vivo hemorrhagic necrosis of certain tumor cells but not normal cells. They also destroy cells associated with the inflammatory response. They have been used as experimental anticancer agents but can also induce shock when bacterial endotoxins cause their release. Tumor necrosis factor α, formerly called cachectin, contains 157 amino acids and is produced by macrophages, eosinophils, and NK cells. Tumor necrosis factor β is lymphotoxin and contains 171 amino acids.
vascular endothelial growth factor (VEGF) (vascular permeability factor (VPF)) a peptide factor that stimulates the proliferation of cells of the endothelium of blood vessels; it promotes tissue vascularization and is important in blood vessel formation in tumors.
von Willebrand's factor (vWF) a glycoprotein synthesized in endothelial cells and megakaryocytes that circulates complexed to coagulation factor VIII. It is involved in adhesion of platelets to damaged epithelial surfaces and may participate in platelet aggregation. Deficiency results in the prolonged bleeding time seen in von Willebrand's disease.
plate·let-de·rived growth fac·tor (PDGF),
a factor in platelets that is mitogenic for cells at the site of a wound, for example, causing endothelial proliferation; cationic glycoprotein mitogen for fibroblasts, smooth muscle cells, and glial cells. Principal factor in serum required for the growth and proliferation of mesenchymal-derived cells in tissue culture.
plate·let-de·rived growth fac·tor(PDGF) (plātlĕt-dĕ-rīvd grōth faktŏr)
Factor that is mitogenic for cells at the site of a wound, e.g., causing endothelial proliferation.
platelet-derived growth factorOne of a range of substances in platelets that promote cell proliferation, cell migration and angiogenesis. Also involved in embryonic development.
platelet-derived growth factor; P-DGF growth factor liberated by platelet endoplasmic reticulum; stimulates macrophages during inflammation and fibroblasts during healing; it increases healing rate of chronic wounds (see becaplermin gel)
plate·let-de·rived growth fac·tor(PDGF) (plātlĕt-dĕ-rīvd grōth faktŏr)
Factor mitogenic for cells at wound site.
a small disk or platelike structure, the smallest of the formed elements in blood. Blood platelets (called also thrombocytes) are disk-shaped, non-nucleated blood elements with a very fragile membrane; they tend to adhere to uneven or damaged surfaces. They average about 250,000 per cubic millimeter of blood and are formed in the red bone marrow by fragmentation of megakaryocytes, the largest of the bone marrow cells. Platelet production is controlled by a hormone, thrombopoietin, and regulatory lymphocytes acting at the stem cell level. At any given time about one-third of the total blood platelets can be found in the spleen; the remaining two-thirds are in the circulating blood.
The functions of platelets are related to the clotting of blood. Because of their adhesion and aggregation capabilities platelets can occlude small breaks in blood vessels and prevent the escape of blood. Platelets which have adhered to exposed collagen in damaged vessels release ADP in milliseconds which in turn initiates the synthesis of thromboxane A2, a very potent prostaglandin which causes platelet aggregation and localized vasoconstriction. Fibrinogen, factors V and VIII, calcium ions, platelet phospholipid (PF-3), associated with the platelet membrane are also released. Substances contained within the platelet granules such as thromboglobulin, heparin neutralizing activity (PF-4) mitogens such as platelet derived growth factor, thrombospondin, ADP, serotonin and calcium ions are also released by aggregated platelets.
platelet-activating factor (PAF)
see platelet-activating factor.
the adherence of platelets to any area with damaged blood vessels; an important component of hemostasis.
the progressive accumulation of platelets, attracted by other platelets once adhesion begins. Thromboxane A2 causes irreversible platelet aggregation.
platelet aggregation test
a known platelet aggregating factor such as collagen, ADP or thrombin is added to a suspension of the platelets under test and the degree of aggregation measured by decrease in turbidity of the suspension.
may be performed directly (in a hemocytometer chamber) or indirectly (estimating from the stained blood smear by number per field or in comparison to the number of white blood cells), expressed as number of cells per liter of blood.
platelet-derived growth factor
one of three growth factors released by platelets which undergo the release reaction; the growth factors stimulate endothelial cell proliferation.
platelet distribution width (PDW)
an indication of variation in platelet size which can be a sign of active platelet release.
platelet factor 3 (PF-3) test, platelet release test
test the antiplatelet activity of serum; used to detect circulating antiplatelet antibodies. Antibody-antigen reactions involving platelets cause the release of PF-3 from platelets which in turn shortens the contact-activated clotting time of platelet-rich plasma (PRP).
factors important in hemostasis which are contained in or attached to the platelets: platelet factor 1 is adsorbed clotting factor V from the plasma; platelet factor 2 is an accelerator of the thrombin-fibrinogen reaction; platelet factor 3 is a phospholipid with potent procoagulant activity; platelet factor 4 is capable of inhibiting the activity of heparin (heparin neutralizing activity).
mean platelet volume (MPV)
elevated level is an indication of increased megakaryocyte shedding of platelets and decreased level is seen in thrombocytopenia.
platelet plug formation
see platelet aggregation (above).
platelet release reaction
measured by the degree of secondary ADP-mediated aggregation that occurs. This is assessed by the amount of PF-4, PF-3 or serotonin, etc. released.
tested by testing the adhesiveness of a suspension of the subject platelets to a glass bead column or standard size filter.
platelet rich plasma
plasma prepared by centrifugation to separate out red blood cells but not platelets for transfusion.
platelet storage-pool disease
an inherited autosomal thrombopathia in American foxhounds and cats characterized by a deficiency of platelet storage granules.
transfusion of fresh, nonchilled whole blood is the usual method of transfusing platelets to an animal with thrombocytopenia.