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91.
G He J Hart OS Kim GL Szot CT Siegel JR Thistlethwaite KA Newell 《Canadian Metallurgical Quarterly》1999,67(1):131-137
Studies were performed to determine the effects of PTH and related compounds on phosphatidylcholine (PC) hydrolysis in UMR-106 cells and the pathway by which the PTH effects occurred. The responses were compared with those of phorbol 12,13-dibutyrate (PDBu). Both bovine PTH-(1-34) [bPTH-(1-34)] and PDBu stimulated PC hydrolysis within 10 min. Significant effects were elicited by concentrations of 0.3-1 nM bPTH-(1-34) and 5 nM PDBu. Dose-dependent increases were seen at higher concentrations of both compounds, however, the response to bPTH-(1-34) was reduced at 30 nM. Bovine or human PTH-(1-34) and human PTH-related peptide-(1-34) [hPTHrP-(1-34)] were equipotent in their effects, whereas bovine [Nle(8,18)Tyr34]PTH-(3-34) amide [bPTH-(3-34)] and hPTH-(1-31) amide [hPTH-(1-31)] were less potent than bPTH-(1-34). bPTH-(3-34) did not antagonize the effects of bPTH-(1-34). Down-regulation of protein kinase C isozymes by 24-h treatment with PDBu completely prevented the stimulatory effect of PDBu on PC hydrolysis, but did not significantly affect the stimulatory effect of bPTH-(1-34). Both bPTH-(1-34) and PDBu stimulated transphosphatidylation of PC, indicating a phospholipase D-stimulated mechanism. The results suggest that in the UMR-106 cell line PTH can stimulate activation of PLD by a mechanism other than through protein kinase C. 相似文献
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2007年早期开始,弹性纤维在许多方面已明显发出了下滑趋势信号,目前的全球金融危机可能加剧了这个问题。即使新的投资者相信他们可以替代现有的供应商,但也有必要研究严重的中期需求和供应的趋势,关注这种趋势同样不可回避全球经济形势中的当前问题,这样可使弹性纤维从当前状态更快地得到恢复。 相似文献
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[Correction Notice: An erratum for this article was reported in Vol 4(3) of Neuropsychology (see record 2010-01278-001). This article does not represent an attempt by the Division 40 Committee on Professional Affairs to define the specialty of clinical neuropsychology, and was not prepared at the request of the Division 40 Committee on Professional Affairs of the American Psychological Association. The publisher extends its apologies for any confusion this may have caused.] Presents an attempt by the Division 40 Committee on Professional Affairs of the American Psychological Association to define the specialty of clinical neuropsychology. The specialty should be defined for psychologists and consumers of psychological services (e.g., government agencies, insurance companies) so that all concerned can have a clearer sense of expectations of qualifications and standards of practice for this field. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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To submit personal problems to psychological analysis is no longer to imply that one is emotionally immature. Psychological intervention can be justified rather differently. Since achieving such a negative energy balance necessitates a change in one's behaviour, the behaviour modifier (of whatever psychological persuasion) does have a role to play. The negative energy balance proposition that I have suggested as the basic assumption for psychological intervention may be a sufficient argument for having psychologists involved in weight management; but with benefit of archival records of more than 15 years of an applied psychology of obesity, our contributors are able to delineate many complexities that are now seen to characterize the experience of fatness in children. Donna White discusses the implications for children of our using Stunkard's categorization of levels of obesity. Michael LeBow examines the evidence on the basic question of whether it is dangerous to be an obese child and then proceeds to consider whether it is dangerous to be treated for obesity. Erik Woody reviews the evidence on these and related issues and shows that much of our clinical lore about the obese child is in need of serious revision. And Coates and Thoreson (1981) will encourage us to return more often to a careful individual functional analysis as the basis for design of a client's weight management programme. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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BACKGROUND: In cardiac hypertrophy, ECG T-wave changes imply an abnormal sequence of ventricular repolarization. We investigated the hypothesis that this is due to changes in the normal regional differences in action potential duration. We assessed the contribution of potassium- and calcium-dependent currents to these differences. Both the altered sequence of ventricular repolarization and the underlying cellular mechanisms may contribute to the increased incidence of ventricular arrhythmias in hypertrophy. METHODS AND RESULTS: Rats received daily isoproterenol injections for 7 days. Myocytes were isolated from basal subendocardial (endo), basal midmyocardial (mid), and apical subepicardial (epi) regions of the left ventricular free wall. Action potentials were stimulated with patch pipettes at 37 degrees C. The ratio of heart weight to body weight and mean cell capacitance are increased by 22% and 18%, respectively, in hypertrophy compared with controls (P<.001). Normal regional differences in action potential duration at 25% repolarization (APD25) are reduced in hypertrophy (control: endo, 11.4+/-0.9 ms; mid, 8.2+/-0.9 ms; epi, 5.1+/-0.4 ms; hypertrophy: endo, 11.6+/-0.9 ms; mid, 10.4+/-0.8 ms; epi, 7.8+/-0.6 ms). The regional differences in APD25 are still present in 3 mmol/L 4-aminopyridine. Hypertrophy affects APD75 differently, depending on the region of origin of myocytes (ANOVA P<.05). APD75 is shortened in subendocardial myocytes but is prolonged in subepicardial myocytes (control: endo, 126+/-7 ms; epi, 96+/-10 ms; hypertrophy: endo, 91+/-6 ms; epi, 108+/-7 ms). These changes in APD75 are altered by intracellular calcium buffering. CONCLUSIONS: Normal regional differences in APD and the changes observed in hypertrophy are only partially explained by differences in I(tol). In hypertrophy, the normal endocardial/epicardial gradient in APD75 appears to be reversed. This may explain the T-wave inversion observed and will have implications for arrhythmogenesis. 相似文献
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