Insulin-like growth factor-1 protects ischemic murine myocardium from ischemia/reperfusion associated injury

Introduction  

Ischemia/reperfusion occurs in myocardial infarction, cardiac dysfunction during sepsis, cardiac transplantation and coronary artery bypass grafting, and results in injury to the myocardium. Although reperfusion injury is related to the nature and duration of ischemia, it is also a separate entity that may jeopardize viable cells and ultimately may impair cardiac performance once ischemia is resolved and the organ heals.     

急性脑血管病患者心肌酶谱监测及临床意义研究

目的 探讨急性脑血管病患者心肌酶谱的变化及其临床意义.方法 选择2005年1月-2007年1月期间住院就诊的80例急性脑血管病患者为病例组,同期健康体检人群80例为对照组.病例组于入院1,7,14 d,对照组于体检当日抽血检测各项心肌酶.结果 ①脑出血组与脑梗死组各指标均高于对照组,但脑出血与脑梗死组各指标差异无统计学意义(P＞0.05);有意识障碍组各指标均高于无意识障碍组(P＜0.05);②好转组各指标均低于恶化组(P＜0.05);③好转组第1,7,14 d各指标的水平呈逐渐下降趋势(P＜0.05).结论 急性脑血管病存在心肌酶谱水平的升高,并且心肌酶谱的监测对于病情、预后、治疗情况判断均具有重要的意义.     

硝酸甘油介入99mTc-MIBI+门控心肌断层显像在心肌干细胞移植中的临床应用研究

[目的]探讨硝酸甘油(NG)介入99mTc-MIBI 门控心肌活力显像在冠心病心梗后病变区心肌细胞是否成活及梗塞灶在干细胞移植治疗后的疗效.[方法]对16例冠心病移植前和移植后的心肌活力 门控心肌断层显像,对心肌灌注活力评分,左室射血分数、移植前移植后心肌梗死区摄取比值测定、心肌灌注缺损指数的观测比较.[结果]干细胞移植后心肌灌注活力评分从57.1%增加到84.2%,左室射血分数从42.1±3.6增加到50.2±2.7、移植前移植后心肌梗死区摄取比值测定22.4±7.3增加到39.7±9.7、心肌灌注缺损指数10.9±2.3减少到8.0±2.5.[结论]心肌活力 门控心肌断层显像, 对临床决策冠心病心肌梗死后是否进行干细胞移植和移植后是否成功提供了较有价值的手段和客观依据.     

幼兔心肌缺血再灌注损伤中生化指标变化的研究

目的 观察幼兔未成熟心肌缺血再灌注损伤后生化指标的变化及异丙酚对损伤的影响.方法 取日本大耳幼兔24只(日龄21-28d)随机分为3组(n=8):缺血再灌注组(A组)、异丙酚预处理组(B组)和对照组(C组).A、B组以结扎冠状动脉前降支制作在体兔心肌缺血再灌注损伤动物模型,B组缺血前给予异丙酚;再灌注120 min时抽动脉血测血清一氧化氮(NO)浓度、一氧化氮合酶(NOS)活性、丙二醛(MDA)浓度、超氧化物歧化酶(SOD)活性和同型半胱氨酸(Hcy)浓度.结果 与C组比较,A组血清MDA及Hcy浓度显著增高(P＜0.05),NOS活性显著降低(P＜0.05),SOD活性降低但无显著性意义;B组血清SOD活性、NO浓度升高(P＜0.05);与A组比较,B组血清NO浓度、SOD及NOS活性增高,MDA、Hcy浓度下降(P＜0.05).结论 异丙酚对实验性幼兔心肌缺血再灌注损伤有保护作用,可能与异丙酚抗氧化作用、激活NOS、增加NO浓度以及减轻Hcy堆积等机制有关.     

穴位电刺激预处理对超负荷训练后大鼠心肌细胞自噬的影响

目的:观察穴位电刺激预处理对长期超负荷训练后大鼠心肌细胞过度自噬的影响,进一步探讨穴位电刺激预处理保护运动心脏的作用机制。方法:根据超负荷概念建立超负荷训练动物模型,取15只雄性SD大鼠随机均分成对照组、超负荷训练组和穴位电刺激预处理组。对照组不予任何处理,超负荷训练组和穴位电刺激预处理组进行8周游泳训练。穴位电刺激预处理组每次训练前进行穴位电刺激,20 min/次,取穴相当于内关和足三里。训练结束24 h内取材,运用透射电镜观察大鼠心肌细胞自噬和凋亡情况。结果:超负荷训练组大鼠心肌细胞线粒体聚集、嵴断裂、空泡化,肌浆网扩张,核膜皱缩、核固缩、核仁消失,染色质聚集、边聚,凋亡小体、自噬体和自噬溶酶体大量生成;与超负荷训练组相比,穴位电刺激预处理组心肌线粒体聚集、嵴断裂、空泡化及核膜皱缩、染色质聚集、边聚等表现明显减轻,同时凋亡小体、自噬体和自噬溶酶体生成显著减少。结论:超负荷训练使大鼠心肌细胞出现过度凋亡和过度自噬,穴位电刺激预处理可以通过减轻心肌细胞凋亡程度、抑制其过度自噬实现保护心脏结构的目的。     

高功率微波辐射对小鼠心肌氧化应激及ATPase的影响

目的观察高功率微波辐射(high power microwave radiation,HPM)对小鼠心肌氧化应激及ATPase活性的影响。方法雄性ICR小鼠32只,随机分为4组(n=8):假照组、微波辐射10 min组、微波辐射20 min组、微波辐射30 min组。采用S波段,平均表面功率为10 mW/cm2微波;照射时间分别为0,10,20,30 min/次,每周2次,共2周。末次辐射完毕,立即处死小鼠,取心脏、冰冷生理盐水冲洗后,加入匀浆液制作匀浆。采用试剂盒测定超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化物酶(GSH-px)活性、总抗氧化能力(T-AOC)、谷胱甘肽(GSH)及丙二醛(MDA)的含量以及Na+K+-ATPase和Ca2+Mg2+-AT-Pase活性。结果微波辐射后,与假照组比,微波辐射20 min组和微波辐射30 min组SOD活性降低(P<0.05)、GSH-px活性增加(P<0.05);而微波辐射20 min组GSH含量明显增加(P<0.01);微波辐射30 min组Ca2+Mg2+-ATPase活性明显降低(P<0.01),其他指标变化无明显统计学差异。结论微波辐射可能引起小鼠心脏氧化应激平衡状态以及Ca2+转运的改变。     

Doppler tissue imaging of the heart in secondary amyloidosis

Secondary amyloidosis (SA) affects cardiac texture and function by interstitial fibrosis. Doppler tissue imaging (DTI) may quantify heart function through the assessment of myocardial velocities. Echocardiographic findings of early cardiac amyloidosis (CA) without heart failure (HF) caused by SA were determined both by standard methods and DTI. It was then determined whether DTI is superior to conventional echocardiography in documenting early CA due to SA. Twenty-five patients with SA who had CA without HF (group 1) were compared with 25 healthy control subjects (group 2). After standard echocardiography, systolic (s), early (e) and late diastolic (a) velocities of interventricular septum, anterolateral, and anterior and inferior walls were measured from mitral annulus by DTI. The averages were called (s_mean), (e_mean), and (a_mean), respectively. Fractional shortening (FS) and ejection fraction (EF) values of groups 1 and 2 were similar. Standard Doppler echocardiographic values were not typical for a specific diastolic abnormality. The (s_mean) and (e_mean) for group 1 were lower but (a_mean) was higher compared with group 2 (all P < .05). The group 1 (e_mean/a_mean) was lower (P < .0001) and (E/e_mean) was higher (P=.003) than in group 2 (both P < .05). (E/e_mean) and (E/e_{lateral wall}) ratios were positively correlated (r=0.74, P < .05). In patients with early CA due to SA without HF, by DTI, (s_mean) and (e_mean) velocities decrease and (a_mean) velocity increases. These may be markers of subclinical CA of SA when standard echocardiography is not informative. (E/e_mean) ratio may be an alternative index to (E/_{elateral wall}).     

自体骨髓单个核细胞移植治疗风湿性心脏病可行性研究

目的观察自体骨髓单个核细胞（BMMNCs）心肌内移植对风湿性心脏病患者心功能的影响，探讨其临床实用性。方法选取以左室扩大为主的风湿性心脏病患者5例，瓣膜置换手术当日采取髂骨骨髓20ml，同上法获得自体BMMNCs悬液备用。瓣膜置换完毕，于特定局部心肌内注入上述细胞悬液，分别于术前、术后1周及术后3个月行门控核素心血池显像（MGBP）检查，评价患者心功能及局部心肌舒缩能力，同时监测围手术期心电图及各项实验室指标。结果患者围手术期均未发现明显不良反应，术后3＋71反映左室收缩功能的各项指标显著升高，左室8个分区局部射血分数（rEF）亦明显升高，尤以S3～S6为著。结论自体BMMNCs心肌内移植方法简便、可靠，进一步的严格对照、多中心、随机双盲的大样本临床实验可以进行。     

Contrast echocardiography in the diagnosis of myocardial stunning

The identification of viable myocardium within dysfunctional myocardium has important clinical implications. By using a microvascular tracer, myocardial contrast echocardiography may have the potential for prediction of myocardial viability in the acute and subacute phases of myocardial infarction. In the case presented, the normal myocardial perfusion observed after intravenous injection of the contrast agent, combined with severe wall motion abnormality following prolonged chest pain, suggested myocardial stunning. This was confirmed by normal coronary angiography and by restoration of normal left ventricular function at 1-month follow-up echocardiography.     

电磁脉冲照射前后大鼠心肌超声背向散射参数变化的研究

目的探讨电磁脉冲照射前、后SD大鼠心肌组织超声背向散射参数变化特点。方法40只二级雄性SD大鼠,单盲法随机分为辐照组和对照组,辐照组给以相应参数的电磁脉冲（EMP）照射,对照组给以假照射。分别于照射前、照射后24 h采集大鼠胸骨旁左室短轴射频图像,并测量感兴趣区心肌背向散射积分（IBS）值、心腔内血池IBS值,计算出标准化心肌背向散射积分（IBS%）,两时间点采集图像后每组各活杀10只大鼠,取心肌组织行透射电镜观察。结果EMP照射后大鼠心肌细胞水肿,细胞器改变。与对照组比较,辐照组照射24 h后左室前后壁IBS%均显著降低（P<0.01）;后壁IBS值减低（P<0.05）。辐照组前、后壁IBS及IBS%均显著降低。结论SD大鼠EMP照射后心肌IBS%值较照射前降低,IBS值有不同程度改变,提示EMP照射后心肌组织的病理学改变。