多巴酚胺和多巴胺在急性心肌梗塞时的对比

为了探明多巴酚胺和多巴胺对心血管之作用,将上述两种药物按10μg/kg/min的速度给两组清醒试验之犬分别于冠状动脉闭塞后开始40分钟输入直至24小时。对照组用5％右旋糖苷。在给药后之第一个30分钟内,多巴酚胺和多巴胺之在心排血量上,左室dp/dt与dp/dt/P上两组都有增高,而在心率,平均动脉血压和局部心肌血流上则无变化。24小时后,多巴酚胺组之心排血量和左室dp/dt与左室dp/dt/p则较对照组出     

肠淋巴液对休克大鼠心肌特性的影响

大鼠重度失血性休克30min后,左心室内压的最大上升速率( dp/dt max)和左心室收缩压(LVSP)都显著下降(P<0.01),而左心室舒张末压(LVEDP)却有所增高(P<0.05)。说明心肌的收缩功能和舒张功能均出现障碍,给少量淋巴液后(用量为0.5ml/100g体重)使休克时下降的左心室内压的最大上升速率和左心室收缩压显著回升(P<0.05),而增高的左心室舒张末压回落不明显,提示淋巴液可改善休克心肌的收缩功能障碍,但对低血容量情况下的心肌舒张功能无明显改善。     

单种群发生传染病的生物总数

主要运用微分方程的基础理论知识对具有这种数学模型dp/dt=ap-bp^2的生物发生传染病时的总数变化进行了研究，得到了生物发生传染病时的总数是随时间而周期性变化的规律。     

用“分数法”巧解整数应用题

有些整数应用题，用整数应用题的思路解比较难，看成分数应用题反而很简便。例１小明从家里步行去学校。如果每分钟走６０米，可以提前２分钟到校；如果每分钟走４０米，则迟到３分钟。小明家离学校多少米？［分析与解］每分钟走６０米，也就是每走１米需１６０分钟；每分钟走４０米，也就是每走１米需１４０分钟。前后两种走法，每走１米相差（１４０－１６０＝）１１２０分钟。由相差（２＋３＝）５分钟，可以求出走的米数是：５÷１１２０＝６００（米）。综合算式是：（２＋３）÷（１４０－１６０）＝６００（米）答：小明家离学校６０…     

太极拳运动对中老年人心脏舒张功能的影响

目的探讨太极拳运动对中老年人心脏收缩功能、心脏舒张功能、顺应性等方面的影响.方法采用多普勒超声心动图对参加二十四式简化太极拳锻炼3个月的33名中老年知识分子进行心脏收缩、舒张功能、顺应性等指标的测试分析.结果太极拳锻炼前后安静状态下心率(HR)、左室舒张早、晚期二尖瓣血流峰值流速E、A峰及E/A比值、左室射血分数(LVEF)、左室短径缩短率(%△D)、每搏输出量(SV)差异均有显著性(p<0.05),以反映左室顺应性的指标E/A改善为明显(0.98±0.18 vs 1.21±0.17 p<0.01).结论太极拳锻炼对中老年人心脏功能,尤其是对左室舒张功能、心脏顺应性有良好影响.     

有趣的“数字化”养生

搭脉数数法清晨醒来，赖床5分钟，让体内器官逐渐苏醒，恢复正常功能。调节好情绪后，便可平心静气地搭脉数数。先数一数每分钟脉动多少次，再感觉一下脉搏是否规则。脉搏可反映机体的状态。每天观察脉搏变化，是获取体内信息、实行自我监测的方法之一。     

复心汤对大鼠急性心肌缺血及左室舒张功能的保护作用

目的:本实验观察复心汤灌胃对大鼠心肌缺血模型的影响.方法:Wistar大鼠60只,雌雄各半,随机分成6组,每组10只.正常对照组:生理盐水灌胃;模型组:生理盐水灌胃;地奥心血康组:等效剂量地奥心血康灌胃(0.12g/kg/d);复心汤高剂量组:6倍等效剂量灌胃(81g/kg/d);复心汤中剂量组:3倍等效剂量灌胃(40.5g/kg/d);复心汤低剂量组:等效剂量灌胃(13.5g/kg/d).每日早晚各一次,连续7天.第8天除正常对照组外,其余各组于给药1小时后,用垂体后叶素(Pituitrinum,pit)制备心肌缺血模型.观察大鼠的心电图(ECG)、心肌组织乳酸脱氢酶(LDH)和肌酸激酶(CK)含量的改变、左室压力下降最大速率(?dp/dtmax)、左室舒张末压(LVEDP)的变化.结果:与模型组比较,复心汤各剂量组和地奥心血康组表现出显著对抗作用(P<0.05,P<0.01).与正常组比较,模型组大鼠CK及LDH活力显著升高,具有极显著性差异(P<0.001).结论:复心汤有治疗和预防心肌缺血的作用,对于心脏舒张功能的防治亦有明显的作用.     

自护知识竞赛题

一、填空（每空０－５分，共计１７分）１－国际通用的求救信号是使用、或，频率是每分钟次，停顿分钟后，重复同样信号。２－我们要熟记的几个特殊电话号码分别是、、等。３－每年的月日是国际禁毒日。４－１９９４年１２月份，中国新疆市发生了一次震惊中外的火灾，使名学生死亡，名师生烧伤。５－如在路上遇雷阵雨，要及时，不可急于。６－１９９３年５月２１日，北京门头沟某小学名学生因吃冰棍中毒，先后出现了、、、、等症状，严重的出现了喉头红肿、心律不齐、高烧、口鼻出血等症状，经９天抢救才脱险。７－扁豆中毒事件时有发生，人…     

“导练式教学”初探

导练式教学，就是在教师指导下，以学生训练为主的教学模式，其宗旨是彻底克服多年来“以教师讲析为主的教学模式”带来的学生课外作业繁重，课堂教学效率不高，学生语文成绩提高不快等老大难问题，从而有助于提高学生学习语文的能力，培养学生的创造力。导练式教学由教师提示讲述（5－10分钟），指导学生训练（25－30分钟），答疑拓展（10－15分钟）三个步获组成，每堂课教师占用的时间由过去的40分钟压缩为ZO分钟以内，学生活动的时间由过去的10分钟左右增加到30分钟以上（根据实际可稍做灵活变动）。这一教学改革体现为下列三个方面的更…     

川芎嗪对麻醉家兔缺血再灌注心肌的保护作用

目的:观察川芎嗪对家兔心肌缺血再灌注损伤的保护作用.方法:采用在体家兔冠状动脉阻断的缺血/复灌损伤模型,测定心肌梗死面积、血浆中乳酸脱氢酶(LDH)、肌酸激酶(CK)及天门冬酸氨基转移酶(AST)活性及各项心室力学指标.结果:与单纯缺血/复灌组相比,川芎嗪明显降低心脏缺血/复灌后的梗死面积和血浆中LDH、CK及AST含量,促进左室收缩压(LVSP)、最大左室收缩速率( dP/dtmax)和最大左室舒张速率(-dP/dtmax)的恢复.结论:川芎嗪预处理对家兔心肌缺血再灌注损伤有良好的保护作用.     

Respiratory face mask: a novel and cost-effective device for use during the application of myocardial ischemia in rats

To shorten operation time and improve survival rate of rats with myocardial ischemia or myocardial infarction, we use a novel device comprised of a face mask and a head/neck retainer in this study. We report the basic design of the novel respiratory face mask (RFM) and evaluate its performance in a rat model of myocardial ischemia. The device is cost-effective and easier to handle than other devices, such as tracheal intubation. Compared with conventional tracheal intubation, we found that RFM shortens operation time significantly while keeping blood indices normal; the mean operation time for rats in the mask group was (32±3) min, and that for the intubation group was (45±7) min (P<0.05). Moreover, the size and shape of the RFM can be changed according to the body weight of rats. In conclusion, RFM is an appropriate device for the establishment of myocardial infarction or ischemia-reperfusion in rats.     

Effects of sevoflurane preconditioning and postconditioning on rat myocardial stunning in ischemic reperfusion injury

Ischemic preconditioning and postconditioning distinctly attenuate ventricular arrhythmia after ischemia without affecting the severity of myocardial stunning. Therefore,we report the effects of sevoflurane preconditioning and postconditioning on stunned myocardium in isolated rat hearts. Isolated rat hearts were underwent 20 min of global ischemia and 40 min of reperfusion. After an equilibration period (20 min),the hearts in the preconditioning group were exposed to sevoflurane for 5 min and next washout ...     

Cardioprotective effects of anesthetic preconditioning in rats with ischemia-reperfusion injury: propofol versus isoflurane

Objective: We compare the cardioprotective effects of anesthetic preconditioning by propofol and/or isoflurane in rats with ischemia-reperfusion injury. Methods: Male adult Wistar rats were subjected to 60 min of anterior descending coronary artery occlusion followed by 120 min of reperfusion. Before the long ischemia, anesthetics were administered twice for 10 min followed by 5 min washout. Isoflurane was inhaled at I MAC (0.016) in I group, whereas propofol was inhaled intravenously at 37.5 mg/(kg.h) in P group. A combination ofisoflurane and propofol was administered simultaneously in I+P group. Results: In control (without anesthetic preconditioning, C group), remarkable myocardial infarction and apoptosis accompanied by an increased level of cardiac troponin T were noted 120 rain after ischemia-reperfusion. As compared to those of control group, I and P groups had comparable cardioprotection. In addition, I+P group shares with I and P groups the comparable cardioprotective effects in terms of myocardial infarction and cardiac troponin T elevation. Conclusion: A combination of isoflurane and propofol produced no ad-ditional cardioprotection.     

Sevoflurane postconditioning reduces myocardial reperfusion injury in rat isolated hearts via activation of PI3K/Akt signaling and modulation of Bcl-2 family proteins

Sevoflurane postconditioning reduces myocardial infarct size.The objective of this study was to examine the role of the phosphatidylinositol-3-kinase(PI3K)/Akt pathway in anesthetic postconditioning and to determine whether PI3K/Akt signaling modulates the expression of pro-and antiapoptotic proteins in sevoflurane postconditioning.Isolated and perfused rat hearts were prepared first,and then randomly assigned to the following groups:Sham-operation(Sham),ischemia/reperfusion(Con),sevoflurane postconditioning(SPC),Sham plus 100 nmol/L wortmannin(Sham+Wort),Con+Wort,SPC+Wort,and Con+dimethylsulphoxide(DMSO).Sevoflurane postconditioning was induced by administration of sevoflurane(2.5%,v/v) for 10 min from the onset of reperfusion.Left ventricular developed pressure(LVDP),left ventricular end-diastolic pressure(LVEDP),maximum increase in rate of LVDP(+dP/dt),maximum decrease in rate of LVDP(?dP/dt),heart rate(HR),and coronary flow(CF) were measured at baseline,R30 min(30 min of reperfusion),R60 min,R90 min,and R120 min.Creatine kinase(CK) and lactate dehydrogenase(LDH) were measured after 5 min and 10 min reperfusion.Infarct size was determined by triphenyltetrazolium chloride staining at the end of reperfusion.Total Akt and phosphorylated Akt(phospho-Akt),Bax,Bcl-2,Bad,and phospho-Bad were determined by Western blot analysis.Analysis of variance(ANOVA) and Student-Newman-Keuls' test were used to investigate the significance of differences between groups.The LVDP,±dP/dt,and CF were higher and LVEDP was lower in the SPC group than in the Con group at all points of reperfusion(P0.05).The SPC group had significantly reduced CK and LDH release and decreased infarct size compared with the Con group [(22.9±8)% vs.(42.4±9.4)%,respectively;P0.05].The SPC group also had increased the expression of phospho-Akt,Bcl-2,and phospho-Bad,and decreased the expression of Bax.Wortmannin abolished the cardioprotection of sevoflurane postconditioning.Sevoflurane postconditioning may protect the isolated rat heart.Activation of PI3K and modulation of the expression of pro-and antiapoptotic proteins may play an important role in sevoflurane-induced myocardial protection.     

Activation of Akt and cardioprotection against reperfusion injury are maximal with only five minutes of sevoflurane postconditioning in isolated rat hearts

It had been proved that administration of sevoflurane for the first two minutes of reperfusion effectively protects the heart against reperfusion injury in rats in vivo.Our aim was to investigate the duration of effective sevoflurane administration and its underlying mechanism in isolated rat hearts exposed to global ischemia/reperfusion(I/R) injury.Adult male Sprague-Dawley rats were randomly divided into six groups(n=12):a sham-operation group,an I/R group,and four sevoflurane postconditioning groups(S2,S5,S10,and S15).In the S2,S5,S10,and S15 groups,the duration times of sevoflurane administration were 2,5,10,and 15 min after the onset of reperfusion,respectively.The isolated rat hearts were mounted on the Langendorff system,and after a period of equilibrium were subjected to 40 min global ischemia and 120 min reperfusion.Left ventricular(LV) hemodynamic parameters were monitored throughout each experiment and the data at 30 min of equilibrium and 30,60,90,and 120 min of reperfusion were analyzed.Myocardial infarct size at the end of reperfusion(n=7 in each group) and the expression of myocardial phosphorylated Akt(p-Akt) after 15-min reperfusion were determined in a duplicate set of six groups of rat hearts(n=5 in each group).Compared with the I/R group,the S5,S10,and S15 groups had significantly improved left ventricular end-diastolic pressure(LVEDP),left ventricular developed pressure(LVDP),and the maximal rate of rise or fall of the LV pressure(±dP/dtmax),and decreased myocardial infarct size(P<0.05),but not the S2 group.After 15 min of reperfusion,the expression of p-Akt was markedly up-regulated in the S5,S10,and S15 groups compared with that in the I/R group(P<0.05),but not in the S2 group.Sevoflurane postconditioning for 5 min was sufficient to activate Akt and exert maximal cardioprotection against I/R injury in isolated rat hearts.     

穴位埋线对冠心病无症状心肌缺血、心肌缺血总负荷的影响

目的 :研究穴位埋线对无症状心肌缺血动态心电图的影响。方法 :以随机对照方法 ,观察治疗组 (穴位埋线 )和对照组 (普奈洛尔组 )对无症状心肌缺血的影响。结果 :两组治疗前后 ,在心肌缺血次数 ,心肌缺血持续时间 ,以及缺血总负荷方面有明显差异 ,P <0 .0 1,与对照组治疗后相比 ,无明显差异 ,P >0 .0 5。结论 :穴位埋线在改善无症状心肌缺血方面具肯定疗效。     

苦参碱对急性心衰猫心功能和血流动力学的影响

目的：研究苦参碱对急性心衰猫心功能和血流动力学的影响方法：以成巴比妥钠造成猫急性心衰模型,iv甘参碱20、40mg/kg,用多道生理记录仪和电磁流量计测定猫的心脏血流动力学参数．结果：苦参碱低、高剂量组均可使LVSP、±dp／dtmax、CO、CI、SI、LVWI显著增加,LVEDP、MAP、TPVR、HR显著下降;高剂量组作用强于低剂量组,给药后15min作用达峰值．结论：苦参碱对戊巴比妥钠诱发的心衰猫具有明显的正性肌力作用,负性频率作用,且能增强心脏舒缩功能,降低外周血管阻力,减轻心脏负荷．说明苦参碱有抗心衰作用．     

黄芪预处理对麻醉家兔心肌缺血再灌注损伤的保护作用

目的:观察黄芪预处理对家兔心肌缺血再灌注损伤的保护作用。方法:采用在体家兔冠状动脉阻断的缺血/复灌损伤模型,测定心肌梗死面积、血浆中乳酸脱氢酶(LDH)和肌酸激酶(CK)活性及各项心室力学指标。结果:与单纯缺血/复灌组相比,黄芪预处理明显降低心脏缺血/复灌后的梗死面积和血浆中LDH、CK含量,促进左室收缩压(LVSP)、最大左室收缩速率( dP/dtmax)和最大左室舒张速率(-dP/dtmax)的恢复。结论:黄芪预处理对麻醉家兔心肌缺血再灌注所致心肌损伤具有保护作用。     

缺血预适应与心肌细胞信号转导

心肌缺血预适应是指心脏短暂缺血后能耐受较长时间的缺血现象,是一种有效的心肌保护方法。心肌缺血预适应与细胞信号转导密切相关。细胞信号转导系统包括:触发物质、中介物质、效应物质并通过这三个方面介导心肌缺血预适应。本文就缺血预适应和心肌细胞信号转导作一综述。