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981.
982.
To understand blood pressure is regulated, and how this regulation is disturbed in hypertension, we need to understand how blood volume is regulated and how the distribution of that volume across the vascular tree is regulated. Here we review the literature on blood volume regulation and how it is disturbed in the pre-diabetic and diabetic state. We also provide a comprehensive overview of vascular dysfunction, discussing the key mechanisms, mediators and pathways which are involved. In particular, we focus on the key concept of endothelial dysfunction and how this has shaped our understanding of hypertension.  相似文献   
983.
Cypher (sirolimus-eluting stent) and Taxus (paclitaxel-eluting stent) have been approved for use in percutaneous coronary intervention. Both of the stents have shown superiority over bare metal stents in reducing major adverse cardiac events, restenosis rates and target vessel revascularisation. Results of clinical trials with head-to-head comparison of Taxus and Cypher stents in patients with obstructive coronary artery diseases have recently been reported. This review compares the performance of Cypher and Taxus stents as noted in observational studies and clinical trials in various types of coronary artery lesions.  相似文献   
984.
In many parts of the world, shipping-related emissions have already exceeded or are expected to soon exceed those from land-based sources. Shipping emissions can be reduced substantially by using some of the same technologies being applied to land-based sources, including cleaner engines and fuels, exhaust control methods, and operational modifications. Various ports are testing the feasibility of these mechanisms with varying degrees of success. What is perhaps most greatly needed is expedited creation of better regulations at all levels, from the International Maritime Organization to port city authorities.  相似文献   
985.
The 5-aryl-1-(4-nitrophenyl)-3-oxo-1,4-pentadienyl pharmacophore was incorporated into four series of compounds 1-4. Compounds 1a-g comprised a cluster of 3-arylidene-1-(4-nitrophenylmethylene)-2-oxo-3,4-dihydro-1H-naphthalenes while the analogues 2a-g consisted of a group of 6-arylidene-2-(4-nitrophenylmethylene)cyclohexanones. Three other compounds prepared in this study were 1-(4-nitrophenylmethylene)-3-(3,4,5-trimethoxyphenylmethylene)-2-oxo-2,3-dihydro-1H-indene 3a as well as two 5-arylidene-2-(4-nitrophenylmethylene)cyclopentanones 4a,b. The compounds were evaluated against human Molt 4/C8 and CEM T-lymphocytes as well as murine L1210 cells. In general, the compounds in series 1 displayed marked cytotoxicity having IC50 values in the 1-5 microM range while the related cyclohexyl analogues in series 2 were slightly less potent (IC50 figures were mainly 5-10 microM). The relative locations of two aryl rings present in all four series were considered to contribute significantly to bioactivity and may have accounted for the virtual absence of cytotoxic properties in series 3 and 4. Most of the compounds were administered intraperitoneally to mice using doses up to and including 300 mg/kg. No mortalities were noted. The inhibiting effect of most of the compounds towards Helicobacter pylori is noteworthy. The modes of action of representative compounds include the induction of apoptosis while some compounds weakly inhibited tubulin polymerisation and human N-myristoyltransferase.  相似文献   
986.
987.
Protein kinases in general are known to be very flexible macromolecules. In this article, the conformational plasticity of the ATP binding site in cyclin dependent kinases is analyzed. Movement of the two lysine residues lining the ATP binding site are shown to play a major role in the conformational variability of the site. Linear models are developed to identify and quantify ligand properties that maximally influence the lysine side chain conformations. A few simple properties of the ligands are shown to account for more than 70% of the variation in the lysine conformations. The results are validated using test data and molecular simulation studies. Illustrative applications of the results of this analysis to finding the appropriate crystal structure for molecular docking and binding mode predictions of novel ligands are provided. This work provides a new approach to quantify ligand-induced conformational changes in the active sites of flexible proteins and to find the appropriate crystal structure for docking novel ligands.  相似文献   
988.
989.
To simulate the effects of acute psychological stress, the effects of stressful computer game in young adult subjects were assessed by various physiological, psychological and biochemical parameters. The results showed a significant increase in the physiological and psychological markers of stress. It is concluded from these results that computer game can be used as an acute laboratory psychological stressor for future studies on physiological effects of stress.  相似文献   
990.
The present study was conducted to observe the effect of graded mechanical stimuli on occurrence of oculocardiac reflex (OCR). The experiments were carried out in twenty albino rabbits of either sex weighing between 1-2 kg. Changes in heart rate and/or cardiac rhythm (oculocardiac reflex) were studied by applying traction with progressively increasing weights to medial rectus muscle. Mean threshold value of square wave mechanical stimulus just sufficient to produce oculocardiac reflex was found to be 19 +/- 8.52 g. As the traction weights were progressively increased, more and more decrease in heart rate was observed. It was concluded that once the threshold value of stimulus was reached, the oculocardiac reflex showed a graded response with progressively increasing traction weights.  相似文献   
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