Growth factors induce the improved cardiac remodeling in autologous mesenchymal stem cell-implanted failing rat hearts

Therapeutically delivered mesenchymal stem cells (MSCs) improve ventricular remodeling. However,the mechanism underlying MSC cardiac remodeling has not been clearly determined. Congestive heart failure (CHF) was induced in rats by cauterization of the left ventricular free wall. MSCs were cultured from autologous bone marrow and injected into the border zone and the remote myocardium 5 d after injury. Ten weeks later,when compared with sham operation,CHF significantly increased nucleus mitotic index,capilla...     

心衰康煎液对实验心衰大鼠左心室内压的影响

目的 :观察中药复方心衰康煎液抗心衰的作用。方法 :取 4 0只成年Wistar大鼠 ,利用腹腔注射盐酸阿霉素的方法 ,连续 6周 ,复制心衰大鼠模型 ,再用心衰康煎液连续治疗 2 8d。利用北京微信达设计制造的Pclab实验记录分析系统观察和分析各组大鼠左心室内压、心电图 ,并观察心肌细胞的病理变化。结果 :心衰康煎液大、小剂量组和模型对照组比较左心室收缩内压显著性升高 (P <0 .0 1) ,病理学观察可见大、小剂量组心肌细胞的变性坏死均有明显减轻。结论 :心衰康煎液可减轻阿霉素对心肌的毒性作用 ,可明显改善心衰大鼠的心功能 ,表明该方有良好的抗心衰作用。     

Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study

In this study, the effects of cardiac fibroblast proliferation on cardiac electric excitation conduction and mechanical contraction were investigated using a proposed integrated myocardial-fibroblastic electromechanical model. At the cellular level, models of the human ventricular myocyte and fibroblast were modified to incorporate a model of cardiac mechanical contraction and cooperativity mechanisms. Cellular electromechanical coupling was realized with a calcium buffer. At the tissue level, electrical excitation conduction was coupled to an elastic mechanics model in which the finite difference method (FDM) was used to solve electrical excitation equations, and the finite element method (FEM) was used to solve mechanics equations. The electromechanical properties of the proposed integrated model were investigated in one or two dimensions under normal and ischemic pathological conditions. Fibroblast proliferation slowed wave propagation, induced a conduction block, decreased strains in the fibroblast proliferous tissue, and increased dispersions in depolarization, repolarization, and action potential duration (APD). It also distorted the wave-front, leading to the initiation and maintenance of re-entry, and resulted in a sustained contraction in the proliferous areas. This study demonstrated the important role that fibroblast proliferation plays in modulating cardiac electromechanical behaviour and which should be considered in planning future heart-modeling studies.     

慢性肺源性心脏病合并冠心病27例临床分析

目的探讨肺源性心脏病合并冠心病的临床特点、心电图变化及转归。方法对27例肺心病合并冠心病患者临床资料进行回顾性分析。结果临床上多表现为不典型性心绞痛、夜间阵发性呼吸困难、胸闷及心悸;心电图示持续性缺血ST-T改变、Ⅱ-Ⅲ度房室传导阻滞,心界向左或左下扩大,心电轴不偏或左偏。结论慢性肺源性心脏病合并冠心病症状、体征相互掩盖,病情复杂,容易误诊和漏诊,所以明确诊断尤为重要。     

Later competence and adaptation in infants who survive severe heart defects

A model of risk potential for developmental outcome was created based on cardiac, medical, surgical, and family-stress factors in 31 children with transposition of the great arteries who had undergone reparative open heart surgery utilizing cardiopulmonary bypass during infancy. Impact of these potential risk factors was assessed by 4 current neurologic measures (neurologic anatomic abnormalities, functional impairment, electroencephalograph [EEG], and Pattern Visual Evoked Potential [PVEP]) and 4 psychologic measures (IQ, achievement, perceptual-motor function, and behavior). Results indicated that adverse developmental outcome was significantly associated with the following medical risk variables: failure of palliative surgery to alleviate hypoxia, prolonged hypoxia, growth failure, congestive heart failure, absence of ameliorating shunting heart defects, stroke, and CNS infection; and two psychosocial moderator variables: socioeconomic status and current life stress. Analysis of a "cumulative risk score" indicated significantly higher risk scores in children with abnormal EEGs, PVEPs, and neurologic examinations. The cumulative risk score highly correlated with composite neurologic outcome (r = .62), IQ (r = -.66), achievement (r = -.60), and perceptual-motor function (r = -.48). While overall outcome was favorable for children with TGA who experienced a single risk event, outcome was compromised if multiple risk factors occurred.     

基于树莓派的实时心脏病辅助诊断

依据心电图特征参数R峰面积与S峰面积比,对正常、异常心电图进行快速二分类以提高心电分类效率和准确率。通过MIT-BIH数据库统计分析,正常心电图R峰面积与S峰面积比远大于异常心电图中的面积比值。在QRS波群检测中,改进QRS波群起止点检测算法,将移动窗口积分法、距离最大值法与斜率突变法3种方法加权平均结果作为QRS起止点最终检测结果,弥补单一算法的不足,提高起止点检测精确度,为面积比计算及后续心脏病辅助诊断提供可靠前提。基于低功耗、便携的树莓派平台实现算法,以树莓派Raspbian系统自带的Python为工具,构建了一个便携、实时的心电辅助诊断平台。     

心喘灵(xc-1)抗心律失常的实验研究

心喘灵(xc-1)能明显对抗乌头硷,BaCl_2和结扎左冠状动脉前降支诱发大鼠的室性心率失常,并能降低大鼠再灌注诱发的心律失常。xc-1能降低离体大鼠右心房的自发频率。对大鼠心电图实验,证明 xc-1有负性频率怍用,负性传导作用,负性自律性、负性频率、负性传导作用可能是 xc-1抗心率失常作用的药理基础。     

急性肾功能衰竭家兔心肌损伤的体液机制

目的：观察急性肾功能衰竭（ARF）家兔心肌匀浆自由基、一氧化氮的变化，探讨心肌损伤的体液机制。方法：60只家兔均分为四组（n=15）。ARF模型1组：皮下注射1％HgCl2（1．3ml／kg．bw）；ARF模型2组：肌肉注射50％甘油（10ml／kg．bw）；以等量生理盐水代替HgCl2和甘油作为对照1、2组。24h后，所有动物颈总动脉放血备检，并选择固定位置。制备10％心肌匀浆。经Aeroset型全自动生化分析仪测定血清反映肾功能的生化指标。检测心肌匀浆丙二醛（MDA）、超氧化物歧化酶（SOD）、一氧化氮（NO）及其合酶（NOS）的变化。结果：与相应对照组比较，ARF模型1、2组心匀浆SOD活性下降、MDA含量升高（P〈0．05），ARF模型1、2组心匀浆NO含量增强、NOS及iNOS活性增强（P〈0．05～0．01）。结论：ARF家兔心肌损伤的机制与自由基损伤及NO升高有关。     

镁对心脏活动的影响

镁在机体内起重要作用,它与三磷酸腺苷等形成复合物而激活许多重要的酶,从而调节糖与蛋白质代谢．缺镁常引起细胞内失钾,并使细胞的氧化磷酸化作用受影响．镁对神经肌肉系统有一定抑制作用．在心血管系统中,镁可影响心肌收缩力、血压、心传导功能与心律,特别是对心律和心电图的影响更为明显．     

三七注射液对家兔坐骨神经动作电位传导与兴奋性影响的研究

目的：研究三七注射液对家兔坐骨神经动作电位传导与兴奋性的影响。方法：观察并比较家兔坐骨神经干动作电位传导速度与传导衰减时间。结果：三七注射液对家兔坐骨神经干动作电位传导速度有明显的提高（P〈0．05）,对家兔坐骨神经干动作电位传导衰减时间有明显的延缓（P〈0．05）。结论：三七注射液可以明显地提高家兔坐骨神经干动作电位传导速度和延缓动作电位传导衰减时间而提高神经纤维的兴奋性,对家兔周围神经纤维具有保护与修复作用,对周围神经功能具有良好的支持作用。     

重组人脑利钠肽治疗急性心力衰竭的疗效观察

目的：探讨在监测血清脑钠肽水平下,短期使用注射用重组人脑利钠肽治疗急性心力衰竭或慢性心力衰竭急性发作的临床效果。方法：48例急性心力衰竭患者根据是否使用注射用重组人脑利钠肽分为常规组和注射用重组人脑利钠肽组,对比两组治疗的临床效果和超声心动图情况,并监测BNP水平。结果：治疗7d后,注射用重组人脑利钠肽组临床有效率明显好于常规组（81．7％vs61．6％,P〈0．05）,左室射血分数明显高于常规组（51±6）％vs（46±5）％,（P〈0．01）,且血清脑钠肽水平明显降低（498±209）pg／mL vs（642±318）pg／mL,（P〈0．01）,血清脑钠肽下降水平和左室射血分数提高水平差异有统计学意义（P〈0．05）,有效者治疗后左室射血分数提高及血清脑钠肽下降均强于无效者（P〈0．01）。结论：在血清脑钠肽指导下短期应用注射用重组人脑利钠肽有助于改善急性心力衰竭患者的临床症状和心功能。     

Early association of electrocardiogram alteration with infarct size and cardiac function after myocardial infarction

Objective: Myocardial infarction (MI) is the main cause of heart failure, but the relationship between the extent of MI and cardiac function has not been clearly determined. The present study was undertaken to investigate early changes in the electrocardiogram associated with infarct size and cardiac function after MI. Methods: MI was induced by ligating the left anterior descending coronary artery in rats. Electrocardiograms, echocardiographs and hemodynamic parameters were assessed and myocardial infarct size was measured from mid-transverse sections stained with Masson's trichrome. Results: The sum of pathological Q wave amplitudes was strongly correlated with myocardial infarct size (r = 0.920, P < 0.0001), left ventricular ejection fraction (r = (0.868, P < 0.0001) and left ventricular end diastolic pressure (r = 0.835, P < 0.0004). Furthermore, there was close relationship between MI size and cardiac function as assessed by left ventricular ejection fraction (r = (0.913, P < 0.0001) and left ventricular end diastolic pressure (r = 0.893, P < 0.0001). Conclusion: The sum of pathological Q wave amplitudes after MI can be used to estimate the extent of MI as well as cardiac function.     

基于IT建设与组织学习的商业银行风险控制系统研究

银行业在本质上是一种风险管理的行业,风险控制活动是我国商业银行的根本性管理活动。IT建设是我国商业银行的一项长期战略,组织学习是我国商业银行的一项前沿性管理行为,共同促进了我国商业银行风险控制能力的提高。通过对IT建设和组织学习在商业银行风险控制功能上的经验性分析,揭示了基于IT建设和组织学习为导向的我国商业银行的风险控制机理,为增强我国商业银行的风险控制功能并提高IT建设和组织学习的成效提供了有效的理论借鉴。     

老年高血压患者监护治牙安全评估及临床对策

观察在心电监护下局麻治疗急性牙髓炎,对老年高血压患者的影响,为其安全治疗提供参考。监测522名老年高血压患者在急性牙髓炎治疗前后及过程中的血压、心率等变化,将测量结果进行分析。患者血压在麻醉即刻及术中比治疗前明显升高(P<0.05),其中收缩压较舒张压变化更为明显。心率在麻醉即刻及治疗中均明显高于治疗前(P<0.05)。病情稳定的老年高血压患者可在心电监护下治牙,Ⅱ、Ⅲ级高血压,可据情况,静脉给药控制性降压,避免高血压危象的发生,严格掌握老年高血压患者治牙适应症,可明显降低治疗中并发症发生的风险,可提高老年高血压患者治牙的安全系数。     

基于CNN与GRU降噪自编码的心电信号分类方法

心电图是一种用来监测心脏活动的标准测试。心电图能够体现心脏异常,包括心律失常,心律失常是心律异常的通称。同一类型的心律失常在同一患者不同阶段的心电信号存在一定差异,不同患者同一类型的心律失常心电信号差异会更大,这对人工判断是一大挑战。提出一种基于降噪自编码的CNN与GRU结合的心电图分类方法,从公共数据库（MIT-BIH）中提取原始心电信号集中进行实验。该集合人为扩大到平均5类心跳实例,并过滤掉高频噪声。该方法对室上（S）和心室搏动（V）的准确率分别为99.49%、99.43%,灵敏度分别为90.55%、96.65%,精确率分别为91.04%、95.46%。结果表明,该模型与目前先进水平在性能上有较大提高,具有良好的可扩展性。     

Upper bound solution of supporting pressure for a shallow square tunnel based on the Hoek-Brown failure criterion

To analyze the stability of a shallow square tunnel, a new curved failure mechanism, representing the mechanical characteristics and collapsing form of this type of tunnel, is constructed. Based on the upper bound theorem of limit analysis and the Hoek-Brown nonlinear failure criterion, the supporting pressure derived from the virtual work rate equation is regarded as an objective function to achieve optimal calculation. By employing variational calculation to optimize the objective function, an upper bound solution for the supporting pressure and the collapsing block shape of a shallow square tunnel are obtained. To evaluate the validity of the failure mechanism proposed in this paper, the solutions computed by the curved failure mechanism are compared with the results calculated by the linear multiple blocks failure mechanism when the Hoek-Brown nonlinear failure criterion is converted into the Mohr-Coulomb linear criterion. The influences of rock mass parameters on the supporting pressure and collapsing block shape are discussed.     

对524例教工体检心电图的分析

为探讨教工心电图异常发生率与年龄及职业的关系,该文分析了作者所在学校的524例教工体检心电图,结果表明:心电图异常发生率随教工年龄增长而升高,ST-T改变发生率教师组显著高于机关干部、工人组(P<0.05)。     

基于奇异值分解熵的心率变异性分析

Assessing the dynamics of heart rate fluctuations can provide valuable information about heart status. In this study, regularity of heart rate variability （HRV） of heart failure patients and healthy persons using the concept of singular value decomposition entropy （SvdEn） is analyzed. SvdEn is calculated from the time series using normalized singular values. The advantage of this method is its simplicity and fast computation. It enables analysis of very short and non-stationary data sets. The results show that SvdEn of patients with congestive heart failure （CHF） shows a low value （SvdEn： 0.056±0.006, p 〈 0.01） which can be completely separated from healthy subjects. In addition, differences of SvdEn values between day and night are found for the healthy groups. SvdEn decreases with age. The lower the SvdEn values, the higher the risk of heart disease. Moreover, SvdEn is associated with the energy of heart rhythm. The results show that using SvdEn for discriminating HRV in different physiological states for clinical applications is feasible and simple.     

Review:Cell therapy in congestive heart failure

Congestive heart failure (CHF) has emerged as a major worldwide epidemic and its main causes seem to be the aging of the population and the survival of patients with post-myocardial infarction. Cardiomyocyte dropout (necrosis and apoptosis) plays a critical role in the progress of CHF; thus treatment of CHF by exogenous cell implantation will be a promising medical approach. In the acute phase of cardiac damage cardiac stem cells (CSCs) within the heart divide symmetrically and/or asym-metrically in response to the change of heart homeostasis, and at the same time homing of bone marrow stem cells (BMCs) to injured area is thought to occur, which not only reconstitutes CSC population to normal levels but also repairs the heart by dif-ferentiation into cardiac tissue. So far, basic studies by using potential sources such as BMCs and CSCs to treat animal CHF have shown improved ventricular remodelling and heart function. Recently, however, a few of randomized, double-blind, pla-cebo-controlled clinical trials demonstrated mixed results in heart failure with BMC therapy during acute myocardial infarction.     

Effects of CS preexposure on inhibition of delay

Two experiments examined the effects of preexposure to a stimulus on the subsequent acquisition of conditioned suppression by rats. Variations in the level of suppression within conditioning trials were noted so thatinhibition of delay (taken here to mean less suppression at the beginning of a trial than at the end) could be detected. Inhibition of delay was observed both during the acquisition of suppression and (in Experiment 1) when suppression began to wane with continued postasymptotic training. Preexposure to the to-be-conditioned stimulus retarded acquisition of suppression and slowed the appearance of inhibition of delay both in acquisition and (in Experiment 1) in postasymptotic performance. Experiment 2 demonstrated that inhibition of delay was attenuated during conditioning that followed preexposure in which the stimulus was paired with a weak reinforcer. These results provide no support for the suggestion that preexposure to a stimulus retards later conditioning because it allows the subject to acquire information about stimulus duration that in turn fosters the development of inhibition of delay. Rather, they are compatible with the suggestion that preexposure causes the stimulus to lose associability.