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51.
Oncostatin M (OSM) is a member of the IL-6 family cytokines that use gp130 as a common signal transducer and exhibits both growth stimulatory as well as growth inhibitory activity depending on the cells. To analyze the mechanism of OSM function, we isolated immediate early responsive genes upon OSM stimulation. Here we describe the novel OSM-inducible gene OIG37 that is related to MyD118 and GADD45. The MyD118 gene has been described as an immediate early gene induced by IL-6 in M1 monocytic cells, and GADD45 was identified as a gene induced by UV or gamma-ray irradiation. Both are considered to function in growth arrest and/or DNA repair. Although the expression of OIG37, MyD118, and GADD45 was rather ubiquitous, it was differentially regulated. As the gp130 mutant defective for activating the STAT3 pathway showed the reduced induction of OIG37 by cytokine stimulation and expression of dominant negative STAT3 inhibited the induction of OIG37 by OSM, STAT3 is involved in OIG37 induction by IL-6 family cytokines. To examine the function of OIG37, we expressed it in NIH3T3 and IL-3-dependent BaF3 cells and found that OIG37 suppressed cell growth without any evidence of apoptosis. Whereas both MyD118 and OIG37 suppressed cell growth in both cell lines, suppression by OIG37 was more efficient than by MyD118. Immunoprecipitation experiments indicated that OIG37 associates with p21, a cyclin-dependent kinase inhibitor, and proliferating cell nuclear antigen.  相似文献   
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Studies have shown that bone marrow cells have the potential to differentiate into a variety of cell types. Here we show that bone marrow cells can repopulate the epithelia of the human gastrointestinal tract. Epithelial cells of male donor origin were distributed in every part of the gastrointestinal tract of female bone marrow transplant recipients. Donor-derived epithelial cells substantially repopulated the gastrointestinal tract during epithelial regeneration after graft-versus-host disease or ulcer formation. Regeneration of gastrointestinal epithelia with donor-derived cells in humans shows a potential clinical application of bone marrow-derived cells for repairing severely damaged epithelia, not only in the gastrointestinal tract but also in other tissues.  相似文献   
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Several signaling cascades are activated during engagement of the erythropoietin receptor to mediate the biological effects of erythropoietin. The members of the insulin receptor substrate (IRS) family of proteins play a central role in signaling for various growth factor receptors and cytokines by acting as docking proteins for the SH2 domains of signaling elements, linking cytokine receptors to diverse downstream pathways. In the present study we provide evidence that the recently cloned IRS-related proteins, Gab1 and Gab2, of the Gab family of proteins, are rapidly phosphorylated on tyrosine during erythropoietin treatment of erythropoietin-responsive cells and provide docking sites for the engagement of the SHP2 phosphatase and the p85 subunit of the phosphatidylinositol 3'-kinase. Furthermore, our data show that Gab1 is the primary IRS-related protein activated by erythropoietin in primary erythroid progenitor cells. In studies to identify the erythropoietin receptor domains required for activation of Gab proteins, we found that tyrosines 425 and 367 in the cytoplasmic domain of the erythropoietin receptor are required for the phosphorylation of Gab2. Taken together, our data demonstrate that Gab proteins are engaged in erythropoietin signaling to mediate downstream activation of the SHP2 and phosphatidylinositol 3'-kinase pathways and possibly participate in the generation of the erythropoietin-induced mitogenic responses.  相似文献   
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A method for an enzymatic assay of histamine by using histamine oxidase from Arthrobacter globiformis in combination with amperometric determination of H2O2 is described. Histamine could be quantified at a level as low as 10(-7) M. The assay is adaptable to determine histamine in food samples including tuna fish with good sensitivity and selectivity.  相似文献   
57.
We have designed and synthesized a series of pyrazole derivatives as candidate retinoic acid receptor (RAR) agonists. One of them, 4-[5-(1, 5-diisopropyl-1H-3-pyrazolyl)-1H-2-pyrrolyl]benzoic acid (11b), which possesses a 2,5-disubstituted pyrrole moiety, showed selective transactivation activity for the RAR alpha receptor, and had highly potent cell-differentiating activity on HL-60 cells.  相似文献   
58.
Prodrug-oriented molecular design was attempted for the potent acyclic neonicotinoid insecticide, clothianidin (1-(2-chloro-5-thiazolylmethyl)-3-methyl-2-nitroguanidine). Molecules bearing a CH2COCH2 bridge linking the 1,3-NH ends of clothianidin or their acetals would possibly be hydrolyzed, regenerating the mother compounds. This strategy was used to prepare seven acetals of clothianidin-based molecules that combined 2-chloro-5-thiazolylmethyl, 6-chloro-3-pyridylmethyl or 3-tetrahydrofurfuryl with a nitroimine, cyanoimine or nitromethylene group. The key intermediate, 1,3-diamino-2,2-dimethoxypropane, was prepared from the dihydroxyacetone dimer in four steps. A selected acetal showed a characteristic nerve-impulse pattern for neonicotinoids on an excised American cockroach ganglion, although the neuroblocking activity was fairly low. Some acetals were highly insecticidal against the pea aphid at 0.8-20 ppm 7 days after a spray treatment, this being in a contrast to their far weaker activity by injection into American cockroaches. The biological results suggest that the intrinsic insecticidal activities of the acetals are weak, but would exhibit enhanced activity if hydrolyzed in an external environment.  相似文献   
59.
A human thiamine pyrophosphokinase cDNA clone (hTPK1) was isolated and sequenced. When the intact hTPK1 open reading frame was expressed as a histidine-tag fusion protein in Escherichia coli, marked enzyme activity was detected in the bacterial cells. The hTPK1 mRNA was widely expressed in various human tissues at a very low level, and the mRNA content in cultured fibroblasts was unaffected by the thiamine concentration of the medium. The chromosome localization of the hTPK1 gene was assigned to 7q34.  相似文献   
60.
Twenty-one patients with pituitary dwarfism were treated with methionine-free hGH (r-hGH) for 6 months with a dosage of 0.5 IU/kg/week. The height of newly treated patients (N = 14), increased from 2.4 to 5.0 cm during treatment, which corresponded to from 4.8 to 10.0 cm with a mean of 8.1 +/- 0.5 cm/year. In switched patients (N = 7), height increased from 2.2 to 3.8 cm during the treatment, which corresponded to 4.4-7.6 cm with a mean of 6.1 +/- 0.5 cm/year, which was similar to that observed in previous treatment with pituitary extracted hGH (p-hGH). Anti-hGH antibody was observed in two patients (9.5%) at the end of 6 months of treatment with a titer of 10. These data indicate that r-hGH has a growth promoting effect and low antigenicity.  相似文献   
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