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31.
Alan R. Gould 《Planta》1977,137(1):29-36
The effects of temperature on the cell cycle of Haplopappus gracilis suspension cultures were analysed by the fraction of labelled mitoses method. Sphase in these cultures shows a different temperature optimum as compared to optima derived for G2 and mitosis. G1 phase has a much lower Q10 than the other cell cycle phases and shows no temperature optimum between 22 and 34° C. These results are discussed in relation to a transition probability model of the cell cycle proposed by Smith and Martin (Proc. Natl. Acad. Sci. USA 70, 1263–1267, 1973), in which each cell has a time independent probability of initiating the transition into another round of DNA replication and division. The implications of such a model for cell cycle analysis are discussed and a tentative model for a probabilistic transition trigger is advanced.Abbreviations FLM
Fraction of labelled mitoses
- TB
Total B-phase 相似文献
32.
In a single-blind controlled clinical trial patients with optic neuritis caused by demyelination were given a single retrobulbar injection of triamcinolone. Though the treated group showed a trend towards more rapid recovery of vision than the controls, there was no significant difference in visual acuity, colour vision, or visual fields during the first six months after treatment. We conclude that routine use of corticosteroids is not justified in unilateral optic neuritis when vision in the other eye is good. Shortening the period of visual disability in bilateral disease or unilateral disease when vision in the other eye is poor, however, may be justifiable. 相似文献
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Dina Zand Jeffrey Hammer Robert Gould Richard Quarles 《Journal of neurochemistry》1991,57(3):1076-1079
The major 24- and 28-kDa glycoproteins in shark PNS and CNS myelin express high levels of the adhesion-associated HNK-1/L2 carbohydrate epitope. The 28-kDa protein, but not the 24-kDa protein, cross-reacts strongly with one of two anti-bovine P0 antisera not previously tested against fish myelin proteins. Shark PNS and CNS myelin also contains smaller amounts of high-molecular-weight HNK-1-positive proteins, including a prominent broad band in the 65-85-kDa range. Although myelin-associated glycoprotein (MAG) is well known to react with HNK-1 in some mammals, monoclonal and polyclonal anti-MAG antibodies did not react with the high-molecular-weight HNK-1-positive material in shark myelin, a result suggesting that it is not a MAG-like protein. The high expression of the HNK-1/L2 epitope in glycoproteins of shark myelin, including the major P0-related ones, suggests that this adhesion-related carbohydrate structure may have had an important role in the molecular evolution of the myelinating process. 相似文献
35.
Regulation of cdc2 activity in Schizosaccharomyces pombe: the role of phosphorylation. 总被引:9,自引:0,他引:9
The cdc2 protein kinase, first identified as a cell cycle gene required for transition into the S- and M-phases of budding and fission yeast, has been shown to act as a key component in the regulation of the eukaryotic cell cycle. The periodic activation of cdc2 kinase, which is required for entry into M-phase, is regulated by subunit association with cyclin B, the cdc25, wee1, mik1 gene products and differential phosphorylation of the cdc2 protein. Phosphorylation at Tyr 15 inhibits activation of the cdc2/cdc13 complex whereas phosphorylation of Thr 167 is required for kinase activity. 相似文献
36.
Expression of GLUT-4 and insulin receptor mRNAs was investigated in rat skeletal muscle by Northern hybridization. GLUT-4 mRNA was barely detectable in foetal muscle, was expressed at low levels by 1-8 days and at 2-3-fold higher levels during and after weaning (18-40 days). In contrast there was little change in insulin receptor mRNA levels prior to weaning and a reduction in mRNA abundance between 18 and 40 days. Weaning rats on to a diet rich in fat prevented the increase in GLUT-4 abundance seen between 15 and 29 days in animals weaned on a high-carbohydrate diet. 相似文献
37.
K. M. Dziegielewska W. M. Brown C. C. Gould N. Matthews J. E. C. Sedgwick N. R. Saunders 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1992,162(2):168-171
Summary Fetuin is a plasma protein present in high concentrations during fetal development in animals of the order Artiodactyla. Its role is not known. The human homologue of fetuin — 2HS glycoprotein — has been shown to be a negative acute phase protein in adult plasma. In the present study, the concentration of fetuin was measured in the serum of healthy cattle (Bovis bovis) and in animals with various injuries and inflammatory disorders. The levels were decreased by 30% in pregnancy but increased up to 10-fold in some trauma cases. A significant negative correlation between the concentrations of fetuin and albumin has also been found. Thus, fetuin appears to be a positive acute phase protein in cattle.Abbreviations 2HS
2HS glycoprotein
- AP
acute phase 相似文献
38.
L. Sawyer C.L. Jones A.M. Damas M.M. Harding R.O. Gould R.P. Ambler 《Journal of molecular biology》1981,153(3):831-835
The dihaem cytochrome c4 from Pseudomonas aeruginosa has been crystallized in space group P6522 with cell dimensions , and one molecule per asymmetric unit. Two heavy-atom derivatives, UO2(NO3)2 and K2Pt(NO2)4, which substitute at one and three sites, respectively, have allowed a low-resolution electron density map to be obtained. This shows clearly the two domains of the molecule. 相似文献
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