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991.
992.
Impact of age,sex, and indexation method on MR left ventricular reference values in the framingham heart study offspring cohort
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993.
MR pulse wave velocity increases with age faster in the thoracic aorta than in the abdominal aorta
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995.
Banding the Right Ventricular Assist Device Outflow Conduit: Is It Really Necessary With Current Devices?
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Casey Lo Shaun Gregory Michael Stevens Deirdre Murphy Silvana Marasco 《Artificial organs》2015,39(12):1055-1061
Implantable left ventricular assist devices (LVADs) have been adapted clinically for right‐sided mechanical circulatory support (RVAD). Previous studies on RVAD support have established the benefits of outflow cannula restriction and rotational speed reduction, and recent literature has focused on assessing either the degree of outflow cannula restriction required to simulate left‐sided afterload, or the limitation of RVAD rotational speeds. Anecdotally, the utility of outflow cannula restriction has been questioned, with suggestion that banding may be unnecessary and may be replaced simply by varying the outflow conduit length. Furthermore, many patients have a high pulmonary vascular resistance (PVR) at the time of ventricular assist device (VAD) insertion that reduces with pulmonary vascular bed remodeling. It is therefore important to assess the potential changes in flow through an RVAD as PVR changes. In this in vitro study, we observed the use of dual HeartWare HVAD devices (HeartWare Inc., Framingham, MA, USA) in biventricular support (BiVAD) configuration. We assessed the pumps' ability to maintain hemodynamic stability with and without banding; and with varying outflow cannulae length (20, 40, and 60 cm). Increased length of the outflow conduit was found to produce significantly increased afterload to the device, but this was not found to be necessary to maintain the device within the manufacturer's recommended operational parameters under a simulated normal physiological setting of mild and severe right ventricular (RV) failure. We hypothesize that 40 cm of outflow conduit, laid down along the diaphragm and then up over the RV to reach the pulmonary trunk, will generate sufficient resistance to maintain normal pump function. 相似文献
996.
目的了解社区老年人积极老龄化现状,并分析其影响因素,为社区护理工作者开展健康促进工作,提高社区老年人的健康水平提供参考。方法采用一般问卷调查表、休闲态度量表和积极老龄化量表对衡阳市某国家级示范社区卫生服务中心275名老年人进行问卷调查。结果老年人休闲态度总分为(3.16±0.55)分,积极老龄化总分为(3.24±0.61)分。不同年龄、文化程度、居住情况、休闲类型和身体机能的社区老年人积极老龄化得分比较,差异有统计学意义(均P0.01);社区老年人休闲态度与积极老龄化呈正相关(均P0.01)。回归分析结果表明,身心健康和自我发展是影响积极老龄化的重要因素。结论社区老年人积极老龄化水平和休闲态度水平均待提高,社区护理工作者应采取措施提高社区老年人的休闲态度水平,促进其达到积极老龄化。 相似文献
997.
两肾一夹肾血管性高血压大鼠(2K1C-RHR)肾脏内的血管重构 总被引:1,自引:0,他引:1
目的 考察两肾一夹肾血管性高血压大鼠 (2K1C RHR)肾入球小动脉结构重构和弓形动脉 ,小叶间动脉的管壁成分重构。方法 用形态学和免疫组化方法考察 2K1C RHR肾入球小动脉的形态改变 ,弓形动脉及小叶间动脉的部分细胞外基质 ,包括胶原、层粘连蛋白、纤维连接蛋白的表达变化和血管平滑肌细胞肌动蛋白的表达改变 ,以观察肾小血管的重构。结果 2K1C RHR双肾入球小动脉均有重构 ,中膜增厚 ,管腔缩小 ,且未受夹侧管腔减小更明显 ;肾内肌型动脉的管壁成分改变明显 ,胶原积聚 ,Ⅲ型胶原、Ⅵ型胶原、纤维连接蛋白表达增加 ,层粘连蛋白和血管平滑肌细胞肌动蛋白表达减少。结论 2K1C RHR双肾入球小动脉发生明显重构 ,未受夹侧管腔缩小更为显著 ,重构更为突出 ;肾内弓形动脉和小叶间动脉也发生明显重构 ,其管壁成分明显变化 相似文献
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Nigel S. Cook Ian D. Chapman 《Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy》1993,7(Z3):555-563
Potassium channel opener's (KCOs) were originally thought of as nonselective smooth muscle relaxants. However, recent investigations in animal models of both peripheral vascular disease (PVD) and asthma have revealed interesting effects of these drugs at unexpectedly low doses. Hemodynamically, KCOs are interesting in PVD since they have little effect on blood supply to normally perfused skeletal muscle, but enhance perfusion to chronically ligated ischemic tissue. In animal PVD models, SDZ PCO-400 and cromakalim have been shown to improve recovery of muscle energy stores from ischemia or to preserve performance under conditions of ischemic contracture. Beneficial effects in rat PVD models were manifest at doses below those affecting systemic blood pressure and may be attributable to a selective dilatation of collateral vessels. With regard to the airways, the apparent efficacy of KCOs as antiasthmatic drugs seems not to be attributable solely to their bronchodilator activity. Although KCOs elicit no antiinflammatory effect in animal models, studies with SDZ PCO-400 in guinea pigs sensitized to antigen or treated with immune complexes have revealed that expression of airway hyperreactivity is significantly inhibited at drug doses exhibiting only modest bronchodilator activity. At least part of this action can be attributed to inhibition at the level of neural innervation of the airways, possibly through attenuation of nonadrenergic noncholinergic (NANC) transmission. Thus, based on results generated in animal models of asthma and PVD, clinical evaluation of the KCOs in these indications would seem warranted, with the hope that (due to their selective actions) beneficial therapeutic effects can be achieved at doses devoid of unwanted systemic actions. 相似文献