As a growth factor

Derivatives. Scopoletin [92-61-5] (6-methoxyumbeUiferone) (38) occurs, for example, in Solanaceae as a growth factor in plants. Primin [15121 -94-5] (2-methoxy-6-pentyl-l,4-benzoquinone) is a skin irritant isolated from Primula ohconica. Versicolin [4389 4-0]... 

The bulk of the industrial supply of the calcium salt of (R)-pantothenic acid is used in food and feed enrichment. Food enrichment includes breakfast cereals, beverages, dietetic, and baby foods. Animal feed is fortified with calcium-(R)-pantothenate which functions as a growth factor. 

A wyo-Inositol, one of the isomers of 1,2,3,4,5,6-hexahydroxycyclohexane, acts as a growth factor in both animals and microorganisms. Draw the most stable chair conformation of myo-inositol. 

A cytokine, secreted by TH2-cells, stimulates B-cells in different stages of their development. It may act as a growth factor or as a differentiation factor, causing B-lymphocytes to switch antibody to IgE. In T-cells it causes differentiation into TH2-cells. 

The same is true of the thiazole acid 40. Although discovered as a growth factor, it is unable to sustain the growth of a thiazole-deficient mutant of E. coli in a liquid medium. It does not decarboxylate in water solution at pH 7. Phosphate 41 (Scheme 17) is also biologically inactive. In any case, if there is only one metabolic route to the thiazole of thiamine, the very structures of 39 and 40 show that they cannot both be intermediates. 

IFN-y also directly modulates the immune response by affecting growth, differentiation and function of both T- and B-lymphocytes. These effects are quite complex and are often influenced by additional cytokines. IFN-y acts as a growth factor in an autocrine manner for some T cell sub-populations, and it is capable of suppressing growth of other T cell types. It appears to have an inhibitory effect on development of immature B-lymphocyte populations, but it may support mature B cell survival. It can both up-regulate and down-regulate antibody production under various circumstances. 

IL-2 acts as a critical autocrine growth factor for T-cells, and the magnitude of the T-cell response is largely dependent upon the level of IL-2 produced. IL-2 also serves as a growth factor for activated B-lymphocytes. In addition to promoting proliferation of these cells, IL-2 (as well as some other interleukins) stimulates enhanced antibody production and secretion. In this way, it effectively potentates the humoral immune response. 

TGF-P was first described as a growth factor capable of inducing transformation of several fibroblast cell lines (hence the name TGFs). It is now recognized that TGF-P actually... 

Growth factor potential The possibility that epoetin alfa can act as a growth factor for any tumor type, particularly myeloid malignancies, cannot be excluded. Hypersensitivity reactions Skin rashes and urticaria are rare, mild, and transient. If an anaphylactoid reaction occurs, immediately discontinue the drug and initiate appropriate therapy. Refer to Management of Acute Hypersensitivity Reactions. Fertility Impairment In female rats treated IV with epoetin alfa, there was a trend for slightly increased fetal wastage at doses of 100 and 500 units/kg. 

Growth factor potential Darbepoetin alfa is a growth factor that primarily stimulates RBC production. The possibility that darbepoetin alfa can act as a growth factor for any tumor type, particularly myeloid malignancies, has not been evaluated. 

Clinical pharmacology Erythropoietin is instrumental in the production of red cells from the erythroid tissues in the bone marrow. The majority of this hormone is produced in the kidney in response to hypoxia, with an additional 10% to 15% of synthesis occurring in the hver. Erythropoietin functions as a growth factor, stimulating the mitotic activity of the erythroid progenitor cells and early precursor cells. Chronic renal failure patients often manifest the sequelae of renal dysfunction, including anemia. Anemia in cancer patients may be related to the disease itself or the effect of concomitantly administered chemotherapeutic agents. 

The ovary also produces inhibin and activin. These peptides consist of several combinations of and 3 subunits and are described in greater detail later. The oc3 dimer (inhibin) inhibits FSH secretion while the 33 dimer (activin) increases FSH secretion. Studies in primates indicate that inhibin has no direct effect on ovarian steroidogenesis but that activin modulates the response to LH and FSH. For example, simultaneous treatment with activin and human FSH enhances FSH stimulation of progesterone synthesis and aromatase activity in granulosa cells. When combined with LH, activin suppressed the LH-induced progesterone response by 50% but markedly enhanced basal and LH-stimulated aromatase activity. Activin may also act as a growth factor in other tissues. The physiologic roles of these modulators are not fully understood. 

Homologs of VR1 with a high threshold (> 52°C) for activation by noxious heat, or sensitivity to membrane stretch, provisionally termed vanilloid receptor-like protein (VRL-1) (Caterina et al., 1999) and stretch-inactivated channel (SIC) (Suzuki et al., 1999), respectively, have been identified. Neither channel is activated by vanilloid agonists (Caterina et al., 1999 Suzuki et al., 1999). A mouse ortholog of VRL-1 acts as a growth factor regulated channel (GRC) permeable to Ca2+ ions (Kanzaki et al., 1999). A splice variant of VR1 (VR.5 sv) that lacks the majority of the intracellular N-terminal domain is refractory to activation by vanilloid agonists, protons or noxious... 

In the early 1940s nutritional studies of young animals raised on diets lacking animal proteins and maintained out of contact with their own excreta (which contained vitamin B12) demonstrated the need for "animal protein factor" which was soon shown to be the same as vitamin B12. The animal feeding experiments also demonstrated that waste liquors from streptomyces fermentations used in production of antibiotics were extremely rich in vitamin B12. Later this vitamin was recognized as a growth factor for a strain of Lactobacillus lactis which responded with half-maximum growth to as little as 0.013 pg/l(10-nM). 

Several other cyclitols have been found capable of replacing mg/o-inositol as a growth factor for various microorganisms, but the observed activities are much lower than that of mi/o-inositol.98 The numerical values which are reported should in any case be regarded as tentative, in view of the fact that mt/o-inositol is a persistent impurity in many cyclitol preparations (see p. 157). 

Generally much less active, or totally inactive, both as a growth factor and in reversing the inhibition of albomycin—ferrimycin type antibiotics. Isolated from low-iron fermentations with 17. sphaerogena in yields of about 0.5 g/1. Also produced by U. maydis. Hydrolyzed by Pseudomonas FC—1 peptidase at N atom of first seryl residue (139). 

A main component of the linear ferrioxamine group (63). Reverses inhibition by ferrimycin antibiotics (148) and acts as a growth factor for Microbacterium lacticum (101). From Streptomyces pilosus (8). Also produced by species of Nocardia and Micromonospora, and by a number of species of Streptomyces (148). 

Antibiotic substance from Aspergillus flavus. Active as a growth factor for Arthrobacter sp. (23, 25). 

The possibility that Neupogen can act as a growth factor for any tumor type cannot be excluded... 

Vitamin B12, cyanocobalamin, is an important biologically active compound. It serves as a hematopoietic factor in mammals and as a growth factor for many microbial and animal species. Its markets are divided into pharmaceutical (96-98% pure) and animal feed (80% pure) applications. All vitamin B 2 is now made commercially by fermentation.50... 

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