Stromal

A critical step in radioprotection involves the IL-1 receptors. Monoclonal antibodies to the type 1 IL-1 receptor block IL-l-induced radioprotection (167). Although this receptor is not present on BM cells, it is present on fibroblasts, which suggests that the effects of IL-1 on stem cells maybe largely indirect and mediated by stromal cell activation (168). Anti-IL-1 receptor (type 1) also sensitizes normal mice to the effects of TBI, which suggests that endogenous IL-1 has an intrinsic radioprotective role. IL-6 induction by IL-1, but not CSF levels, is inhibited, which supports the concept that G-CSF and GM-CSF are insufficient by themselves at radioprotecting stem cells and indicates a contributory role for IL-6. Anti-IL-6 antibody blocks IL-1 and TNF-induced radioprotection and also decreases the intrinsic radioresistance of mice, as does anti-TNF- a (169). 

FIGURE 22.20 The molecular architecture of PSI. PsaA and PsaB constitute the reaction center dimer, an integral membrane complex P700 is located at the lumenal side of this dimer. PsaC, which bears Fe-S centers and Fb, and PsaD, the interaction site for ferre-doxin, are on the stromal side of the thylakoid membrane. PsaF, which provides the plasto-cyaiiin interaction site, is on the lumenal side. (Adapted from Golbeck, J. H., 1992. Amiual Review of Plant Physiology and. Plant Molecular Biology 43 293-324.)... 

As discussed in Section 22.7, illumination of chloroplasts leads to light-driven pumping of protons into the thylakoid lumen, which causes pH changes in both the stroma and the thylakoid lumen (Figure 22.27). The stromal pH rises, typically to pH 8. Because rubisco and rubisco activase are more active at pH 8, COg fixation is activated as stromal pH rises. Fructose-1,6-bisphosphatase, ribulose-5-phosphate kinase, and glyceraldehyde-3-phosphate dehydrogenase all have alkaline pH optima. Thus, their activities increase as a result of the light-induced pH increase in the stroma. 

Osteoblasts are the primary cells responsible for bone formation. They are derived from mesenchymal (stromal) cells that first differentiate into pre-osteoblasts and then into mature, bone matrix producing osteoblasts. Inactivated or resting osteoblasts become lining cells and thus a reservoir for bone forming cells to be activated at the next remodelling cycle. Osteoblasts trapped and embedded in the mineralised matrix are called osteocyts, and are important for many properties of living bone. 

An osteoblast is the cell forming new bone. Osteoblasts are derived from stromal bone marrow stem cells. 

S unitinib (Sutent ) Pfizer TKI VEGFR, PDGFR, KIT, FLT-3, RET 1 matinib-resistant KIT overexpressing unresectable or metastatic gastro-intestinal stromal tumor... 

An extract from the soluble stromal proteins of purified and intact spinach-leaf chloroplasts was prepared by lysis of the cells in buffer, centrifugation of the suspension of broken cells, and concentration of the supernatant with removal of insoluble material. This extract contained all of the enzymes involved in the condensation of the cyclic moieties of thiamine, thiazole, and pyramine. Thus, the synthesis of thiamine in this extract following the addition of pyramine and putative precursors was a proof that the system had the possibility of building the thiazole. It was found that L-tyrosine was the donor of the C-2 carbon atom of thiazole, as in E. coli. Also, as in E. coli cells, addition of 1 -deoxy-D-f/irco-pen-tulose permitted synthesis of the thiamine structure. The relevant enzymes were localized by gel filtration in a fraction covering the 50- to 350-kDa molecular-mass range. This fraction was able to catalyze the formation of the thiazole moiety of thiamine from 0.1 -mM 1-deoxy-D-t/ireo-pentulose at the rate of 220 pmol per mg of protein per hour, in the presence of ATP and Mg2+. 

EDI), and water to produce a group of biodegradable PU foams. The interconnected pores varied in size from 10 to 2 mm in diameter. Rabbit bone-marrow stromal cells cultured on the materials for up to 30 days formed multilayers of confluent cells and were phenotypically similar to those grown on tissue culture PS. It supported the adherence and proliferation of both bone-marrow stromal cells and chondrocytes in vitro. In subdermal implants the investigators found that the material showed infiltration of both vascular cells and connective tissue. 

E. (1978). The lymphatic spread of ovarian germinal and stromal tumors, Lymphology, 11, 22-26. 

Liu YJ Thymic stromal lymphopoietin and 0X40 ligand pathway in the initiation of dendritic cell-mediated allergic inflammation. J Allergy Clin Immunol 2007 120 238-246. 

Kato A, Favoreto S Jr, Avila PC, Schleimer RP TLR3- and Th2 cytokine-dependent production of thymic stromal lymphopoietin in human airway epithelial cells. J Immunol 2007 179 1080-1087. 

Malefyt R. Meng Q. Kay AB. Phipps S. Lee TH. Ying S Early production of thymic stromal lymphopoie-tin precedes infiltration of dendritic cells expressing its receptor in allergen-induced late phase cutaneous responses in atopic subjects. Allergy 2009 64 1014-1022. 

McArthur JC (2004) HIV dementia an evolving disease. J Neuroimmunol 157(l-2) 3-10 McArthur JC, Hoover DR, BaceUar H, MUler EN, Cohen BA, Becker JT, Graham NM, McArthur JH, Seines OA, Jacobson LP et al (1993) Dementia in AIDS patients incidence and risk factors. Multicenter AIDS Cohort Study. Neurology 43(ll) 2245-2252 McManus CM, liu JS, Hahn MT, Hua LL, Brosnan CE, Berman JW, Lee SC (2000) Differential induction of chemokines in human microgUa by type I and II interferons. GUa 29(3) 273-280 McQuibban GA, Butler GS, Gong JH, BendaU L, Power C, Clark-Lewis I, OveraU CM (2001) Matrix metaUoproteinase activity inactivates the CXC chemokine stromal ceU-derived factor-1. J Biol Chem 276(47) 43503 3508... 

McQuibban GA, Butler GS, Gong JH, Bendall L, Power C, Clark-Lewis I, Overall CM (2001) Matrix metalloproteinase activity inactivates the CXC chemokine stromal cell-derived factor-1. J Biol Chem 276 43503 3508... 

HIV strains are grouped according to the preferred site of replication. T-tropic viruses prefer replication in T lymphocytes and M-tropic viruses in macrophages. Use of chemokine receptors differs for each subgroup CXCR4 (or fusin, the receptor for stromal cell-derived factor [SDF-1]) for T-tropic viruses and CCR5 (the receptor... 

Aiuti A, Turchetto L, Cota M, Cipponi A, Brambilla A, Arcelloni C, Paroni R, Vicenzi E, Bordignon C, Poh G (1999) Human CD34(+) cells express CXCR4 and its ligand stromal cell-derived factor-1. Implications for infection by T-ceU tropic human immunodeficiency virus. Blood 94(l) 62-73... 

D Apuzzo M, Relink A, Loetscher M, Hoxie JA, Clark-Lewis I, Melchers F, Baggiolini M, Moser B (1997) The chemokine SDF-1, stromal cell-derived factor 1, attracts early stage B cell precursors via the chemokine receptor CXCR4. Eur J Immunol 27 1788-1793 Dawson VL, Dawson TM, Uhl GR, Snyder SH (1993) Human immunodeficiency virus type 1 coat protein neurotoxicity mediated by nitric oxide in primary cortical cultures. Proc Natl Acad Sci USA 90 3256-3259... 

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