H2S对兔左心室心肌细胞电生理特性的影响

目的:探讨硫化氢(H2S)对兔左心室心肌细胞电生理特性的影响.方法:用标准微电极细胞内记录技术,观测硫化氢对兔左心室心肌细胞电生理特性的影响.观测指标:静息电位(resting potential,RP)、超射值(over-shoot,OS)、动作电位幅值(amplitude of action po-tential,APA)、0相最大除极速率(maximal rate of depolarization,Vmax)、复极20%、50%和90%时间(20%、50%and 90% of duration of action potential,APD20、APD50and APD90)及复极化平均速度(average rate of repolarization).结果:(1)用50μmol/L NaHS 灌流时,和正常对照组相比,APD50、APD90缩短(P＜0.01),复极化平均速度增快(P<0.05).(2)100μmol/L NaHS与对照组比较,APD50、APD90缩短(P＜0.01),复极化平均速度增快(P<0.05).和50μmol/L NaHS相比APD50缩短(P＜0.01)、APD90缩短(P＜0.05)、复极化平均速度增快(P<0.05).(3)200μmol/L NaHS、400μmol/L、1 000μmol/L NaHS可浓度依赖性的使 APA、RP、OS减小(P<0.01),APD20、APD50、APD90缩短(P＜0.01),复极化平均速度增快(P<0.01).结论:H2S可浓度依赖性的影响兔左心室心肌细胞电生理特性.     

Elevated high sensitive C-reactive protein and apelin levels after percutaneous coronary intervention and drug-eluting stent implantation

Objective:Percutaneous coronary intervention(PCI) triggers an acute inflammatory response,while sirolimus is known to have anti-inflammatory properties;the inflammatory system response to PCI after sirolimus-eluting stent placement remains unclear.The purpose of this study is to determine the changes in high sensitive C-reactive protein(hs-CRP) and apelin after PCI procedure and drug-eluting stent implantation in patients with and without reduced left ventricular systolic function.Methods:Forty-eight consecutive patients undergoing PCI at the Beijing Anzhen Hospital between July and September 2006 were recruited.Sirolimus-eluting stents were employed in all patients.Blood samples were drawn immediately before and 24 h after the procedure.Plasma hs-CRP and apelin levels were determined by enzyme immunoassay.Results:Paired t-test revealed a significant increase in both hs-CRP and apelin post-procedure(P=0.006 and P0.0001,respectively).Patients with reduced left ventricular ejection fraction(LVEF) had significantly lower baseline apelin levels compared to those with normal ventricular function [(46.8±10.8) vs.(72.0±8.4) pg/ml,P0.001].However,apelin increased to a level similar to the level of those with normal left ventricular systolic function 24 h after the PCI procedure [(86.7±11.6) vs.(85.1±6.1) pg/ml,P=0.72].Conclusions:hs-CRP and apelin levels increased after PCI and sirolimus-eluting stent implantation.Patients with impaired left ventricular systolic function had significantly lower baseline apelin levels,which increased significantly after PCI.     

高血压大鼠与正常大鼠左室流出道动作电位的分析

目的:为了研究高血压大鼠左室流出道电位的变化。方法:利用大鼠的离体心脏,采用常规玻璃微电极细胞内记录方法。观察静息电位(RP)、0相去极幅度(APA)、0相最大除极速度(Vmax)、复极时程(APD)以及复极50％(APD_(50))和复极90％(APD_(90))的时间。结果:高血压大鼠左室流出道诱发电位APD、APD_(50)、APD_(90)都明显高于正常同龄大鼠(P<0.01)。结论:高血压大鼠左室流出道动作电位复极时程延长。     

短期力量训练对少年左室收缩功能的影响

24名初二男生随机分成力量训练组和对照组,经12周低强度力量训练后的超声心动图的每搏量(SV),每分输出量(CO)、心指数(COI)、射血分数(EF％)在负荷状态下与12周前有明显增加,且有统计学意义(P<0.01),同时在同级负荷时与对照组有统计学意义的差异(P<0.05)而左室后壁厚度(PWT)、室间膈未见明显变化。表明短期力量训练可提高少年左室收缩功能,而低强度力和量训练不引起心室壁增厚,提示心肌肥大对训练刺激具有强度依赖性。     

木兰拳对中老年心血管系统机能影响的研究

本文运用遥测心率及血压测定的方法，研究了30名木兰拳爱好者同一练内容，不同练习时间心血管机能的变化情况，研究表明，在单个套路练习过程中，心率升高的幅度不大，两路，三路连续练习下来，最大主率也稳定在120次／分钟，只是本人最大心率的75％，运动后即刻收缩压高于运动前，舒张压低于运动前，在恢复期内，收，舒压下降，到恢复期第5分钟时，各次练习的收，舒压均低于运动前水平。本文认为，木兰拳是一种中等强度运动，只要合理控制运动量，坚持锻炼，能够有效提高中老年心血管系统机能。     

Streptomycin inhibits electrophysiological changes induced by stretching of chronically infarcted rat hearts

Objective

To investigate stretch-induced electrophysiological changes in chronically infarcted hearts and the effect of streptomycin (SM) on these changes in vivo.

Methods

Sixty Wistar rats were divided randomly into four groups: a control group (n=15), an SM group (n=15), a myocardial infarction (MI) group (n=15), and an MI+SM group (n=15). Chronic MI was obtained by ligating the left anterior descending branch (LAD) of rat hearts for eight weeks. The in vivo blockade of stretch-activated ion channels (SACs) was achieved by intramuscular injection of SM (180 mg/(kg·d)) for seven days after operation. The hearts were stretched for 5 s by occlusion of the aortic arch. Suction electrodes were placed on the anterior wall of left ventricle to record the monophasic action potential (MAP). The effect of stretching was examined by assessing the 90% monophasic action potential duration (MAPD₉₀), premature ventricular beats (PVBs), and ventricular tachycardia (VT).

Results

The MAPD₉₀ decreased during stretching in both the control (from (50.27±5.61) ms to (46.27±4.51) ms, P<0.05) and MI groups (from (65.47±6.38) ms to (57.47±5.76 ms), P<0.01). SM inhibited the decrease in MAPD₉₀ during inflation ((46.27±4.51) ms vs. (49.53±3.52) ms, P<0.05 in normal hearts; (57.47±5.76) ms vs. (61.87±5.33) ms, P<0.05 in MI hearts). The occurrence of PVBs and VT in the MI group increased compared with that in the control group (PVB: 7.93±1.66 vs. 1.80±0.86, P<0.01; VT: 7 vs. 1, P<0.05). SM decreased the occurrence of PVBs in both normal and MI hearts (0.93±0.59 vs. 1.80±0.86 in normal hearts, P<0.05; 5.40±1.18 vs. 7.93±1.66 in MI hearts, P<0.01).

Conclusions

Stretch-induced MAPD₉₀ changes and arrhythmias were observed in chronically infarcted myocardium. The use of SM in vivo decreased the incidence of PVBs but not of VT. This suggests that SACs may be involved in mechanoelectric feedback (MEF), but that there might be other mechanisms involved in causing VT in chronic MI.     

肾上腺素对离体豚鼠左心室流出道组织自律性电活动的影响

目的:观察肾上腺素(E)对离体豚鼠左心室流出道组织自发慢反应电位的影响.方法:采用标准玻璃微电极细胞内记录技术,观察E对离体豚鼠左心室流出道组织自发慢反应电位的影响.观测指标有:最大舒张电位(MDP),动作电位幅度(APA),0期最大除极速度(Vmax),4期自动除极速度(VDD),自发放电频率(RPF),复极50%和90%时间(APD50、APD90).结果:用100μmol/L E灌流,豚鼠左心室流出道自律组织动作电位APA明显增大(P<0.01),Vmax明显增快(P<0.05),MDP显著增大(P<0.05),APD90显著缩短(P<0.01);RPF明显增快(P<0.01),VDD明显加快(P<0.05).结论:E对左心室流出道组织自律细胞有兴奋作用.     

Postconditioning of sevoflurane and propofol is associated with mitochondrial permeability transition pore

Background: Sevoflurane and propofol are effective cardioprotective anaesthetic agents, though the cardioprotection of propofol has not been shown in humans. Their roles and underlying mechanisms in anesthetic postconditioning are unclear.Mitochondrial permeability transition pore (MPTP) opening is a major cause of ischemia-reperfusion injury. Here we investigated sevoflurane- and propofol-induced postconditioning and their relationship with MPTP. Methods: Isolated perfused rat hearts were exposed to 40 min of ischemia followed by 1 h of reperfusion. During the first 15 min of reperfusion, hearts were treated with either control buffer (CTRL group) or buffer containing 20 μmol/L atractyloside (ATR group), 3% (v/v) sevoflurane (SPC group),50 μmol/L propofol (PPC group), or the combination of atractyloside with respective anesthetics (SPC ATR and PPC ATR groups). Infarct size was determined by dividing the total necrotic area of the left ventricle by the total left ventricular slice area (percent necrotic area). Results: Hearts treated with sevoflurane or propofol showed significantly better recovery of coronary flow,end-diastolic pressures, left ventricular developed pressure and derivatives compared with controls. Sevoflurane resulted in more protective alteration of hemodynamics at most time point of reperfusion than propofol. These improvements were paralleled with the reduction of lactate dehydrogenase release and the decrease of infarct size (SPC vs CTRL: (17.48±2.70)% vs (48.47±6.03)%,P＜0.05; PPC vs CTRL: (35.60±2.10)% vs (48.47±6.03)%, P＜0.05). SPC group had less infarct size than PPC group (SPC vs PPC:(17.48±2.70)% vs (35.60±2.10)%, P＜0.05). Atractyloside coadministration attenuated or completely blocked the cardioprotective effect of postconditioning of sevoflurane and propofol. Conclusion: Postconditioning of sevoflurane and propofol has cardioprotective effect against ischemia-reperfusion injury of heart, which is associated with inhibition of MPTP opening. Compared to propofol, sevoflurane provides superior protection of functional recovery and infarct size.     

Comparison study of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography

Objectives: To directly compare the quality of harmonic imaging (HI) and fundamental imaging (FI) in fetal echocardiography and to determine any differences in image quality between the two modalities. Methods: Fetal echocardiograms were performed with the use of FI and HI in 58 fetuses, image quality and visualization of left and right atria, left and right ventricles, mitral and tricuspid valves, aortic and pulmonary valves, left and right ventricular outflow tracts were evaluated and compared between FI and HI. Results: Mean HI scores were higher than mean FI scores (2.73±0.43 vs 2.16±0.69, P<0.001)for all the cardiovascular structures evaluated. Compared with FI, HI improved the image quality and visualization of fetal cardiac structures in subjects with both good (2.73±0.43 vs 2.88±0.32, P<0.001) and suboptimal (1.65±0.41 vs 2.58±0.47, P<0.001) echocardiographic windows. The interobserver correlation coefficient for the grading scores was 0.74 (P<0.001). Conclusions: harmonic imaging enhances and improves the image quality of fetal echocardiography; and has important potential role in cardiac imaging in the fetus.     

Study on the serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) in patients with Helicobacter pylori Infection

Objective: To evaluate the interaction between serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) and Helicobacter pylori (H. pylori) infection in patients with chronic gastritis and peptic ulcer. Methods: The serum levels of sICAM-1 in 205 patients with chronic gastric diseases were detected by ELISA method and the status of H. pylori was determined by histologic examination, RUT, 14C - UBT, and serology. The sera obtained from 18 healthy volunteers served as controls. Results: The serum levels of sICAM-1 were significantly higher in patients with H. pylori positive than those of H. pylori negative (889.43±32.52 ng/ml vs. 747.07±30.45 ng/ml, P<0.05). The serum levels of sICAM-1 in patients with mild, moderate and severe infection of H. pylori were 841.68±72.36 ng/ml, 905.43±37.59 ng/ml and 1012.54±49.34 ng/ml,respectively (P<0.05). The serum levels of sICAM-1 proved to be significantly correlated with the density of H. pylori colonization in gastric mucosa (rs =0.316, P<0.001). The serum levels of sICAM-1 in patients with chronic gastritis and peptic ulcer were significantly higher than those in healthy controls (P<0.05). Conclusions: These results indicated that H. pylori infection up-regulates the expression of sICAM-1.     

Clinical investigation of surgery for intermittent exotropia

Objective: To investigate the time and postoperative binocular vision of strabismus surgery for children with intermittent exotropia (X (T)). Methods: A retrospective investigation was conducted in 80 child patients with intermittent exotropia. Pre- and postoperative angles of deviation fixating at near (33cm) and distant targets (6m) were measured with the prolonged alternate cover testing. The binocular function was assessed with synoptophore. Twenty-one patients took the postoperative synoptophore exercise. Results: (1) A week after surgery, 96.2% of the 80 patients had binocular normotopia, while a year after surgery, 91.3% of the 80 patients had binocular normotopia; (2) Preoperatively, 58 patients had near stereoacuity, while postoperatively, 72 patients achieved near stereoacuity (P<0.05); (3) Preoperatively, 64 patients had Grade I for the synoptophore evaluation and postoperatively, 76 patients achieved Grade I. Meanwhile, 55 patients had Grade Ⅱpreoperatively and 72 achieved Grade Ⅱ postoperatively. For Grade Ⅲ, there were 49 patients preoperatively and 64 patients postoperatively (P<0.05); (4) Patients of 5～8 years old had a significantly better recovery rate of binocular vision than those of 9～18 years old (P<0.05); (5)Patients taking postoperative synoptophore exercise had a better binocular vision than those taking no exercise (P<0.05). Conclusions: (1) Strabismus surgery can help to preserve or restore the binocular vision for intermittent exotropia; (2) Receiving the surgery at young ages may develop better postoperative binocular vision; (3) The postoperative synoptophore exercise can help to restore the binocular vision.     

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。     

Long-term inhibition of Na+/H+ exchange attenuates cardiac remodeling after myocardial infarction in rats

Objective: In addition to pH regulation, Na⁺/H⁺ exchange (NHE) has been shown to facilitate cell growth and proliferation. However, the effects of long-term inhibition of Na⁺/H⁺ exchange on cardiac structural and functional remodeling post myocardial infarction (MI) are still controversial. The present study was therefore carried out to further investigate the effects of long-term treatment with cariporide, a specific inhibitor of NHE-1, on cardiac remodeling after MI in rats; Methods: Male Wistar rats that underwent coronary ligation were randomly selected for cariporide treatment starting 6 h after induction of MI or no treatment. Treatment was continued up to 6 weeks post MI, after which, the arterial, venous and left ventricular catheters were chronically implanted. Twenty-four h later, after hemodynamic signals were recorded in conscious rats, they were sacrificed and hearts were taken out for morphological examinations; Results: Cariporide treatment decreased the heart weight and heart weight to body weight ratio (bothP<0.05), decreased left ventricular end-diastolic pressure (P<0.001), improved myocardial contractility (dP/dt _max) (P<0.05) and tended to increase the survival of treated rats compared to that of untreated infarct rats; Conclusion: The results of the present study indicate that the long-term inhibition of NHE with cariporide can attenuate cardiac structural remodeling and improve left ventricular dysfunction in infarcted rats, and suggest that Na⁺/H⁺ exchange inhibition could be an effective therapeutic strategy for myocardial infarction-induced heart failure.     

肠淋巴液对大鼠心室肌细胞内动作电位的影响

淋巴液使太鼠心室肌细胞动作电位APD_(90)、APD_(50)显著延长,这种作用可被Ca~(2 )阻断剂阻断,而对动作电位RP、SP_0D、APA无明显影响。提示:淋巴液可直接作用于心肌细胞,增加心肌收缩力,提高心脏泵血功能。     

自制P300/CNV刺激器与诱发电位仪配套建立正常人P300/CNV数据库

测试自行研制的P300/CNV事件相关电位刺激器与普通诱发电位仪(Neuropack 2 MEB-7102K,日本光电公司)配套系统的性能,建立本实验室不同年龄、性别正常人P300、CNV数据库。通过70例正常人P300、CNV检测,分析潜伏期、波幅、反应时和波形。实验结果显示,P300潜伏期随年龄增长而延长,50~55龄段延长更明显,各年龄段间方差分析具有统计学意义(P<0.001)。年龄与P300潜伏期Pearson相关系数为r=0.399(P=0.001),回归系数为1.367(P=0.001)。不同年龄段CNV的指令后负变(PINV)时程和反应时均有显著统计意义(P=0.031;0.048)。结果显示,P300潜伏期、CNV的PINV时程和反应时均随着年龄增长而延长;女性P300、CNV波幅均高于男性;同一受试者前后测得波形具有较好的重复性;部分患者波形变异明显;自制的P300/CNV刺激器与普通诱发电位仪配套使用性能稳定,重复性好,测试结果与有关报道基本相符。     

文化传统对教育信息化的影响

化传统对教育信息化有着重大的影响，表现在物质、制度、观念三个层面，且三个层面对教育信息化的影响叶递增关系。     

Efficacy of amiodarone and lidocaine for preventing ventricular fibrillation after aortic cross-clamp release in open heart surgery: a meta-analysis of randomized controlled trials

Objective

The relative preventative efficacy of amiodarone and lidocaine for ventricular fibrillation (VF) after release of an aortic cross-clamp (ACC) during open heart surgery has not been determined. This meta-analysis was designed to systematically evaluate the influence of amiodarone, lidocaine, or placebo on the incidence of VF after ACC.

Methods

Prospective randomized controlled trials (RCTs) that compared the VF-preventative effects of amiodarone with lidocaine, or amiodarone or lidocaine with placebo were included. PubMed, EMBASE, and the Cochrane Library were searched for relevant RCTs. Fixed or randomized effect models were applied according to the heterogeneity of the data from the selected studies.

Results

We included eight RCTs in the analysis. Pooled results suggested that the preventative effects of amiodarone and lidocaine were comparable (relative risk (RR)=1.12, 95% confidence interval (CI): 0.70 to 1.80, P=0.63), but both were superior to the placebo (amiodarone, RR=0.71, 95% CI: 0.51 to 1.00, P=0.05; lidocaine, RR=0.63, 95% CI: 0.46 to 0.88, P=0.006). The percentage of patients requiring electric defibrillation counter shocks (DCSs) did not differ significantly among patients administered amiodarone (RR=0.21, 95% CI: 0.04 to 1.19, P=0.08), lidocaine (RR=2.44, 95% CI: 0.13 to 44.02, P=0.55), or the placebo (RR=0.56, 95% CI: 0.25 to 1.25, P=0.16).

Conclusions

Amiodarone and lidocaine are comparably effective in preventing VF after ACC, but the percentage of patients who subsequently require DCSs does not differ among those administered amiodarone, lidocaine, or placebo.

     

人参皂苷化学修饰物PM1抗肿瘤活性的研究

[目的]人参皂苷化学修饰物PM1是人参皂苷酶代谢产物M1与棕榈酸发生酯化反应形成的脂肪酸类酯化合物,通过对PM1进行药理学观察,确定其是否具有抗肿瘤活性.[方法]采用移植肿瘤动物模型,以生理盐水组、环磷酰胺组作对照,对小鼠腹腔注射进行药理学观察.[结果]PM1对小鼠肝移植肿瘤(HepA)的抑制作用与对照组比较有显著差异(P<0.001),肿瘤抑制率为49.92%.PM1对胃移植肿瘤(MFC)的抑制作用与对照组比较有显著差异(P<0.001),肿瘤抑制率为49.96%.[结论]PM1对小鼠肝肿瘤(HepA)、胃肿瘤(MFC)有明显的抑制作用.     

螺内酯对老年人重度心力衰竭的疗效观察

目的 :探讨小剂量醛固酮拮抗剂螺内酯治疗老年人重度慢性充血性心力衰竭 (CHF)疗效和安全性。方法 :采用多中心、随机、单盲、安慰剂对照、平行组试验。入选老年重度CHF患者 15 2例 ,随机分为螺内酯组 (A组 )和对照组 (B组 ) ,均予标准三联抗心衰治疗 ,A组联用螺内酯 (2 0～ 4 0mg/d) ,B组联用与螺内酯外观相同的淀粉安慰剂。治疗前和治疗后 2周、4周、8周分别进行心功能 (NYHA)分级评估 ,心电图、超声心动图、血常规、生化等检查 ,并进行对照。结果 :治疗 8周后A、B两组心功能分级、无创心排量指标均显著改善 (P <0 .0 5 ) ;与B组比较 ,A组改善更显著 (P <0 .0 5 )。无肝、肾功能损害及血脂、血糖升高 ,未见高血钾症 ,毒副作用少。结论 :应用螺内酯治疗老年人重度CHF疗效肯定、可靠、安全性好、值得推广。     

大鼠实验性胃溃疡期间大脑皮层SS免疫组织化学和原位杂交组织化学研究

目的 观察大鼠实验性胃溃疡期间大脑皮层生长抑素免疫反应(SS-ir)和SSmRNA神经元的变化。方法 免疫细化PAP法;地高辛标记反意SScRNA探针mRNA原位杂交组化法。结果 正常大鼠SS-ir神经元广泛分布于大脑皮层。溃疡术后1d,大脑皮层纹状皮质区各层SS-ir神经元减少,但可见大量串珠样SS强阳性纤维,溃疡组SS-ir神经元数与盐水组相比无差异;术后4d,溃疡组大脑皮层纹状皮质区各层SS-ir神经元密集、数量明显增多,与盐水组、正常组相比均有差异(P<0.05,P<0.01或P<0.001)。术后10和23d,以上核区SS-ir神经元数仍高于盐水组和正常组(P<0.01,P<0.001)。术后4d,溃疡组大脑皮层SSmRNA神经元数量明显多于盐水组(P<0.001)。结论 大鼠实验性胃溃疡时期,大脑皮层SS-ir和SSmRNA神经元可能参与了胃溃疡自愈过程的调节。