运动心脏结构可复性的研究

为了进一步探讨运动心脏结构与功能的可复性问题及其与病理心脏的本质差异，通过实验动物模拟运动心脏，观察了停止运动训练8周后心脏重量和某些超微结构的变化，并应用激光扫描共聚焦显微镜与新一代钙荧光指示剂fluo－3／AM负载方法对。心肌活细胞内具有生物活性的游离钙的动态变化进行了研究。结果显示，经过12周耐力训练后，心肌活细胞内游离钙浓度静息值无显著性改变，心肌收缩时其游离钙浓度峰值较对照组显著增高11％（P＜0．05）；心肌细胞内心房特殊颗粒的体密度、面密度及数密度分别显著增高41％、12％及5％；心肌细胞线粒体体密度及其与肌原纤维比值分别显著增高60％和61％，线粒体内膜和嵴体积密度显著增高18％；心肌毛细血管与肌纤维的比值显著增高78％；心肌毛细血管腔体密度和面密度分别显著增高28％和13％。停止训练8周后，心肌收缩时其胞内游离钙浓度峰值较训练时显著降低14％（＜0．05）；心肌细胞内心房特殊颗粒的体密度显著降低25％；心肌细胞线粒体体密度及其与肌原纤维比值分别显著降低25％和36％，线粒体内膜和嵴体积密度显著降低11％；心肌毛细血管与肌纤维的比值分别显著降低29％。心肌毛细血管腔体密度和面密度分别显著降低14％和12％，基本恢复到正常对照水平。研究结果表明?

运动心脏重塑的发生与转归

为了进一步探讨运动心脏结构与功能的发生、转归及其与病理心脏的本质差异 ,作者通过动物实验模拟运动心脏 ,观察了经过 1 2周耐力训练及完全停止运动训练 8周后心脏重量和超微结构的变化 ,并应用激光扫描共聚焦显微镜与新一代钙荧光指示剂 Fluo- 3/ AM负载方法对心肌活细胞内具有生物活性的游离钙的动态变化进行了研究。结果表明 ,运动心脏超微结构和胞内钙产生了良好的适应性改变 ,心肌收缩时收缩结构钙可获得量增多 ,构成运动心脏心肌收缩性、氧化代谢及自分泌功能增强的重要细胞机制。完全停训后 ,运动心肌细胞内游离钙 ,心房特殊颗粒 ,心肌线粒体及毛细血管结构适应性改变的消退证实运动心脏结构与功能改变具有可恢复性 ,区别于病理心脏。

心力衰竭时大鼠心肌细胞肌浆网钙回摄的变化

目的:探讨心力衰竭时心肌细胞肌浆网钙回摄异常的机制。方法:结扎大鼠冠状动脉左前降支制备慢性心衰模型。4周后采用酶解法分离假手术组和心衰组大鼠心室肌细胞,利用激光扫描共聚焦显微镜检测心肌细胞肌浆网钙含量。采用western-blot技术检测心肌细胞肌浆网钙调蛋白SERCA2a、PLN、PP1的表达水平。结果:心衰组的大鼠心肌细胞荧光强度小于假手术组,并且心衰组大鼠心肌细胞咖啡因诱导的钙瞬变也低于假手术组;心衰组大鼠心SERCA2a表达水平降低,PP1的水平升高,PLN总体水平不变,但磷酸化的PLN水平降低。结论:钙泵表达量下降和钙泵活性降低是心力衰竭时心肌细胞肌浆网钙回摄减少的主要原因。

Finance Policy for Public Health Disease Prevention: Addressing the Number One Cause of Death in the Western World

Background: The lack of a finance policy to cover heart coronary artery disease CT imaging led to an epidemic of heart disease, the most common cause of death in the United States. The difficulty for many adults to pay $150 for CT heart imaging was the impetus for public health reform through legislative intervention. Methods: The key to finance policy reform was the organization of the medical environment involved in asymptomatic heart disease. Using the ecosystem paradigm for organizational alignment, the legislative goal was financing the $150 heart image to identify and medically prevent symptomatic heart disease, obviating future surgical costs of >$100,000. Results: Assisted by stakeholders for public health reform, a 3-year initiative to pass a legislative bill mandating health insurance coverage of $150 heart imaging was signed into law. Understanding the legislative process was necessary for successful advancement of public health and eliminating unnecessary costs of an established conservative ecosystem. Conclusions: Texas was the first state to achieve this legislative goal and New Mexico soon followed. If political environments, regardless of country following this road map of public health reform, a significant beneficial impact upon heart disease, its cost, and healthier public would result.

运动心脏结构与功能的发生与转归

为了进一步探讨运动心脏结构与功能的发生、转归及其与病理心脏的本质差异 ,本文通过动物实验模拟运动心脏 ,观察了经过 1 2周耐力训练及完全停止运动训练 8周后心脏重量和超微结构的变化 ,并应用激光扫描共聚焦显微镜与新一代钙荧光指示剂Fluo-3 /AM负载方法对心肌活动细胞内具有生物活性的游离钙的动态变化进行了研究。结果显示 :经过 1 2周耐力训练后 ,心肌活细胞内游离钙浓度静息值无显著性改变 ,心肌收缩时其游离钙浓度峰值较对照组显著增高 1 1 %(P <0 .0 5) ;心肌细胞内心房特殊颗粒的体密度、面密度及数密度分别显著增高 4 1 %、1 2 %及5%;心肌细胞线粒体体密度及其与肌原纤维比值分别显著增高 60 %和 61 %,线粒体内膜和嵴体积密度显著增高1 8%;心肌毛细血管与肌纤维的比值显著增高 78%;心肌毛细血管腔体密度和面密度分别显著增高 2 8%和 1 3 %。完全停止训练 8周后 ,心肌收缩时其胞内游离钙浓度峰值较训练时显著降低 1 4%(P <0 .0 5) ;心肌细胞内心房特殊颗粒的体密度显著降低 2 5%;心肌细胞线粒体体密度及其与肌原纤维比值分别显著降低 2 5%和 3 6%,线粒体内膜和嵴体积密度显著降低 1 1 %;心肌毛细血管与肌纤维的比值分别显著降低 2 9%。心肌毛细血管腔体密度和面密度分别显著降低 1 4%和 1

心力衰竭时心肌细胞肌浆网钙释放的变化

探讨慢性心力衰竭时心肌细胞肌浆网内钙离子释放的变化。方法：采用冠状动脉左前降支结扎法制备大鼠慢性心衰模型，酶解法分离成年大鼠心室肌细胞。用全细胞模式膜片钳技术和共聚焦显微镜钙成像技术同步实时记录心肌细胞的L_型钙电流以及胞质内的钙瞬变。结果：心衰组的钙诱导钙瞬变幅度小于对照组，并且心衰组的咖啡因诱导钙瞬变幅度也低于对照组。结论：心力衰竭的发生与心肌细胞内钙离子释放变化有着十分密切的关系。

细胞内游离钙在运动心脏重塑中的作用

本文建立了运动心脏的实验动物模型，应用激光扫描共聚焦显微镜与新一代钙荧光指示剂Ｆｌｕｏ－３／ＡＭ的方法，对心肌活细胞内具有生物活性的游离钙的动态变化进行了研究，以期了解运动心脏结构与功能重塑的细胞机制。结果显示：经过１２周耐力训练后，心肌细胞内游离钙浓度静息值无显著性改变，心肌收缩时其游离钙浓度峰值较对照组显著增高１１％（Ｐ＜０．０５）。停止训练８周后，心肌收缩时胞内游离钙浓度峰值较训练时显著降低１４％（Ｐ＜０．０５），恢复到正常对照水平。研究结果提示，运动心脏可保持细胞内钙稳态，心肌收缩时收缩结构钙可获得量增多，是运动心脏心肌收缩性增强的重要机制之一，同时，心肌细胞内游离钙的增多对于运动心脏肥大的发生也起重要的介导作用，而且，运动心肌细胞内游离钙的改变是一种可逆性变化。

Effect of angiotensin converting enzyme inhibitor on the calcium transients and calcium handling proteins in ventricular myocytes from rats with heart failure

Background Chronic heart failure (CHF) is associated with calcium transients and calcium handling proteins. Angiotensin converting enzyme (ACE) inhibitor has been demonstrated to have beneficial effect on CHF. Yet studies addressed to the relationship between ACE inhibitor and calcium transients in CHF are rare. The aim of this study was to investigate the influence of ACE inhibitor (perindopril) on the contractility and calcium transients and calcium handling proteins in ventricular myocytes from rats with experimental heart failure.Methods Male Wistar rats were randomized to heart failure group treated with perindopril (CHF-T, 3 mg·kg -1 ·d -1 ), heart failure group without treatment (CHF-C) and sham-operated group (PS). Heart failure was induced by abdominal aortic constriction. All groups were further followed up for 12 weeks. Left ventricular myocytes were then isolated. Single cell shortening fraction and [Ca 2+ ]_i were simultaneously measured by laser scanning confocal microscope under the field stimulation (1.0 Hz). Reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot were performed to evaluate the changes of mRNA and protein of Na +-Ca 2+ exchanger (NCX_1), sarcoplasmic reticulum Ca 2+ -ATPase (SERCA_2) and phospholamban (PLB).Results The fraction of cell shortening (FS%) and [Ca 2+ ]_ imax (nmol/L) were significantly reduced in group CHF-C compared with group PS (FS%: 7.51±1.15 vs 13.21±1.49;[Ca 2+ ]_ imax :330.85±50.05 vs 498.16±14.07; both P <0.01), and restored at least partially in CHF-T group. In CHF-C group, the left ventricular mRNA of NCX_1 and PLB were significantly upregulated in comparing with PS group (R_ NCX1/β-Actin : 0.51±0.12 vs 0.19±0.06, P <0.01; R_ PLB/β-Actin : 0.26±0.12 vs 0.20±0.08, P <0.05), while SERCA_2 mRNA was downregulated (0.48±0.10 vs 0.80±0.11, P <0.01). The mRNA levels of NCX_1 and SERCA_2 in CHF-T group were between the CHF-C and PS group, and the differences of the latter two groups were significant (all P <0.05). In CHF-C and CHF-T groups, the protein expression of NCX_1 were 1.141±0.047 and 1.074±0.081 times of that in PS group respectively (both P <0.05), and SERCA_2 protein levels were 0.803±0.100 and 0.893±0.084 times of that in PS group respectively (both P <0.05). The protein expression of NCX_1 and SERCA_2 in the CHF-C and CHF-T groups is significantly different (both P <0.05).ConclusionACE inhibitor could improve cardiac function of failing heart through directly enhancing the contractility of single cardiomyocyte, and these effects are probably mediated by its roles in preventing the deleterious changes of calcium transients and calcium handling proteins in CHF.

利用非门控胸部CT平扫数据行冠状动脉钙化积分评价的可行性分析

目的 探讨利用非门控胸部CT平扫数据评定冠状动脉钙化积分(coronary artery calcium scoring, CACS)的准确性、可行性。方法 选取临床需要同时做胸部CT平扫和冠状动脉CT血管造影(CTA)检查的患者(BMI≤25kg/m^(2))且CACS扫描时发现有冠状动脉钙化患者165例,采用标准的计算CACS的图像重建要求分别对两种扫描方法获得原始数据进行重建,然后对主动脉根部管腔CT值、标准差(SD)、图像信噪比(SNR)、冠状动脉钙化斑块(CAC)的最大CT值以及CAC的数量、体积与质量进行测量和对比,再分别计算每种扫描方法对应的Agatston(AS)积分,最后进行统计学处理。结果 两种不同扫描方法对主动脉根部管腔内CT值、SD、SNR、对比度噪声比(contrast-to-noise ratio, CNR)、CAC最大CT值、CAC的数量、体积、质量以及AS评分差异均有统计学意义(P<0.05)。胸部CT平扫相比CACS扫描,无论是对所有患者的危险分组还是对符合条件的部分患者的危险分层,均有低分组患者数量明显增多,高分组患者数量相对减少。其中52.35%的患者经胸部CT平扫时获得的危险分层情况与CACS扫描的分层情况一致,有40.94%的患者向下移动了一个层级,即危险分层被低估了一个层级。结论 利用非门控胸部CT平扫数据评价CACS还是有一定误差的,但考虑到这只是额外提供诊断信息,只要对结果判读时留意到这一差别还是有积极的指导意义。