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101.
Tyrosine phosphorylation of specific proteins after mitogen stimulation of chicken embryo fibroblasts. 总被引:24,自引:7,他引:17 下载免费PDF全文
We found that stimulation of density-inhibited chicken embryo fibroblasts with serum, epidermal growth factor (EGF), platelet-derived growth factor, (PDGF), or multiplication-stimulating activity (MSA) leads to an increase in tyrosine phosphorylation of proteins in the region of Mr 40,000 (40K) to 42K. The increase in tyrosine phosphorylation after serum or EGF stimulation was transient, reaching a maximum at about 5 min and then declining. By fine-resolution analysis of proteins separated on sodium dodecyl sulfate-polyacrylamide gels, we found that after EGF stimulation, the major increase in phosphotyrosine content was in a 42K Mr protein, with a smaller increase in a 40K Mr protein. The increased phosphorylation in the 40K to 42K Mr region accounted for almost all of the increase in phosphotyrosine observed in these cells. These phosphotyrosine-containing proteins were different from the major phosphotyrosine-containing protein of Rous sarcoma virus-transformed chicken embryo fibroblasts, which migrates at an approximate Mr of 36K. Increased tyrosine phosphorylation of proteins of similar Mr was found in 3T3 cells treated with EGF, but not in NR-6 cells, which lack detectable EGF receptors. It is possible that the 40K to 42K Mr phosphotyrosine-containing proteins are involved in the integration of the biological response to a number of different growth factors. 相似文献
102.
Robert C. Corlett M.D. Boonlaw SribyattaDaniel R. Mishell Jr. M.D. Charles BallardRobert M. Nakamura Ph.D. Ian H. Thorneycroft 《Prostaglandins & other lipid mediators》1972
The abortifacient activity of prostaglandin F2α was investigated by placing one or two 50 mg tablets of prostaglandin F2α in THAM salt into the vagina of nine women less than 4 weeks pregnant at intervals of 2 to 4 hours for a 24 hour period. Serum levels of HCG, estradiol (E2), progesterone and 17α-hydroxyprogesterone were measured by radioimmunoassay prior to starting therapy and at frequent intervals thereafter for 48 hours. All but two patients had significant side-effects, mainly diarrhea and vomiting, indicating that systemic absorption took place. Although bleeding was induced in 8 of 9 women, only 3 had complete abortions. A D&C was performed on all patients 48 hours after starting therapy. A significant fall in HCG levels was noted only in the patients who aborted. Only 3 of the 9 women had significant changes in steroid levels. A fall in progesterone and 17α-hydroxyprogesterone occurred in the 3 women who aborted and took place following the fall in HCG. Estradiol levels remained in the same range in all subjects. These findings indicate that prostaglandin F2α when administered in this vehicle and this dosage is relatively ineffective as an abortifacient. When effective, its action would appear to be due to contractions of uterine muscle and not secondarily to luteolysis. 相似文献
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Modification of the growth of human mycoplasmas in tissue culture by infection with influenza virus and Japanese encephalitis (JE) virus 总被引:1,自引:0,他引:1
107.
Experimental bacillary dysentery in rabbits 总被引:1,自引:0,他引:1
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109.
Experimental thyroiditis in complement intact and deficient mice following injections of heterologous thyroglobulins without adjuvant 总被引:3,自引:0,他引:3
110.
Action mechanism of glucose oxidase of Aspergillus niger 总被引:1,自引:0,他引:1