二维斑点追踪技术评价低温兔左室纵向功能

目的:探讨应用二维斑点追踪技术评价低温条件下兔左心室纵向功能的价值。方法:30只新西兰兔随机分成对照组(n=10),低温组A(n=10),低温组B(n=10)。先行常规心脏数据测量,然后采用组织多普勒(TDI),之后应用斑点追踪成像(STI)中的获取基底段、中间段、心尖段及整体水平SL、SrLs.SrL E,SrL A及分层应变技术获取3个长轴切面心内膜下、中层和心外膜下心肌收缩期纵向峰值应变(SL)。结果:①与对照组相比,A组心内膜下心肌LS值的减低,差异有统计学意义(P<0.05),B组3层心肌SL值的减低明显,差异有统计学意义(P<0.01)②与对照组相比,A组大部分纵向应变及应变率减低(P<0.05);B组基底段、中间段、心尖段及整体水平SL,SrL S、SrLE、SrLA均减低(P<0.01)结论:随低温时间延长,左室壁3层心肌SL值受累程度不同,心内膜应变较心外膜更加敏感,二维班点追踪技术比LVEF及TDI更早发现左室功能减低。     

高钙预处理对未成熟心肌的保护作用机制

目的 探讨高钙预处理对未成熟心肌保护作用及其可能的机制。方法 采用Langendorff离体心脏灌注模型，24只新生日本长耳大白兔分为对照组（I／R），高钙预处理（HCP）组，多黏菌素B（PMB）组和5-hydroxydecanoate（5-HD）组4组，分别行不同的处理方法。以血流动力学指标、生化指标和心肌超微结构作为观察指标。结果 HCP组心功能恢复优于I／R、PMB和5-HD组（P〈0．05），心肌生化指标优于I／R、PMB和5-HD组（P〈0．01），心肌超微结构损伤较I／R、PMB和5-HD组明显减轻，各指标I／R、PMB和5-HD组间差异无统计学意义（P〉0．05）。结论 高Ca^2＋预处理对未成熟心肌具有明显的保护作用，其机制是可能是通过蛋白激酶C激活和线粒体ATP敏感性钾通道开放起作用。     

心肌和骨骼肌对低血钙不同反应性机理的初步研究

本实验采用枸椽酸钠等静脉输入复制家兔低血钙。实验动物血钙显著下降,同时出现骨骼肌抽搐和心肌收缩性下降。测定骨骼肌匀浆钙含量在低血钙前、后均比心肌匀浆高。认为这两种肌肉细胞内固有钙含量的差异,是低血钙时骨骼肌收缩亢进和心肌收缩性下降的原因之一,其次为神经肌肉的兴奋性改变。     

两种激光致心肌血管重建的组织学效应

目的；研究两种激光在心肌血管重建术（TMR）中的组织学效应。方法：实验犬随机分为2组：连续波CO2激光组（n=20）及调制Nd：YAG激光组（n=10），2组均经心外膜法行激光打孔，观察激光孔道的组织学改变。结果：CO2激光孔道周围出现明显的碳化带、凝固性坏死层及心肌变性层，经8周的修复，出现不同程度的微循环改建，尤以碳化程度轻的部位为著；而Nd：YAG激光孔道未见碳化物形成，凝固性坏死及心肌变性范围明显减小，术中并发症的发生均较CO2激光减轻。结论：Nd：YAG激光孔道的热损伤程度轻，有利于心肌内微循环改建，以改善心肌供血，且具有术中并发症少等优点。     

缺血预适应对缺血-再灌注心肌细胞的保护作用

目的观察缺血预处理（IPC）对心肺转流（CPB）中缺血-再灌注心肌损伤及心功能恢复的影响。方法将72只健康家猫随机均分为：单纯CPB组、缺血-再灌注组和IPC组。在猫CPB模型的基础上，测定猫心肌丙二醛（MDA）含量、血清乳酸脱氢酶（LDH）水平和心肌组织磷脂酶A2（PLA2）活性的变化，观察术中心功能的变化。结果IPC组CPB中的血清LDH浓度、心肌MDA含量和心肌组织PLA2活性均明显低于缺血-再灌注组，心脏复跳后各心功能指标的恢复明显优于缺血-再灌注组。结论IPC可减轻CPB中缺血-再灌注心肌细胞的损伤，有利于术后早期心功能的恢复。     

EPO预处理对培养心肌细胞缺氧/复氧损伤TNF-α表达的影响及机制

目的 观察促红细胞生成素（erythropoietin，EPO）预处理对培养心肌细胞缺氧复氧前后TNF-α表达的影响，并进一步研究其可能的NF-kB信号机制。方法采用培养乳鼠心肌细胞建立缺氧复氧损伤模型，分为对照组、EPO组[缺氧复氧前24h，培养液中加入终浓度10U/ml的重组人促红素（recombinant human erythropoietin，RHuEPO）]、EPO＋吡咯烷二硫氨基甲酸盐（PDTC）组（缺氧复氧前24h，加入终浓度10U／ml的RHuEPO和5μg/ml的PDTC）和PDTC组（缺氧复氧前24h，加入终浓度5μg/ml的PDTC）。分别于缺氧复氧损伤前后，以RT-PCR和western blot检测各组心肌细胞TNF-α基因表达变化，同时以EMSA检测各组心肌细胞NF-kB活性变化。结果缺氧复氧损伤前，各组心肌细胞TNF-α基因表达水平差异无统计学意义，均较弱。损伤后各组心肌细胞TNF-α基因表达水平较损伤前对照组显著升高（P〈0．01），而EPO组TNF-α基因表达水平低于其他各组（P〈0．01）。缺氧复氧损伤前EPO组NF-kB活性高于其他各组（P〈0．01），损伤后各组NF-kB活性显著高于损伤前对照组（P〈0．01），EPO组NF-kB活性低于其他各组（P〈0．01）。结论EPO预处理抑制缺氧复氧后心肌细胞TNF-α基因表达升高，可能与缺氧复氧后NF-kB活性升高被抑制有关。EPO预处理可能通过NF-kB活化的负反馈机制抑制缺氧复氧后心肌细胞NF-kB活性的升高。     

肺切除术影响围手术期右心功能

Objective To investigate the changes of perioperative right ventricular function after pulmonary resction. Methods 45 cases of pulmonary resection were divided into four groups.Group Ⅰwas wedge resection(n = 10), GroupⅡ was lobectomy(n = 19), Group Ⅲ was double lobectomy(n=7)and Group Ⅳ was pneumonectomy(n=9). The changes of CVP, PAMP, PEP/ET, Sa, VTIs, RVSP, Ea/Aa, and Tel were evaluated by traditional ultrasonic and tissue Doppler ultrasonic techniques at different time inter- vals (pre-operation, 5-7 days orland 1 month post-operation), Results Compared with the pre-operation CVP, the indexes of all groups have no significant changes post-operatively. Wedge resection didn' t obviously influence right cardiac after load and systolic function/diastolic function. No evidet changes detected in Tei pre-and post-operatively. However, the indexes (PAMP, RVSP and PEP/ET ratio) reflecting right cardiac afterload evidently increased at post-pneumonectomy or lobectomy group5- 7 days post-opera- tive. All these reflect the decrease of Tei, which was more obvious in pneumonectomy than in lobectomy group. Right cardiac after- load, systolic/diastolic function and Tel index recovered to pre-operative level 1 month post-operation in single lobectomy group. But the above indicators, especially the Tel, were still high in double lobectomy and pmeunonectomy groups 1 morth post-operation.Tei index is positively correlated with PAMP and is weakly correlated with PET/ET ratio and Ea/Aa ratio. Conclusion Pulmonary wedge resection doesn't evidently influence right cardiac function. However, right cardiac diastolic function evidently decreases temporarily at lobectomy group. The systolic function and diastolic funetions decrease after double-lobectomy and pneumonectomy and it's more evident in pneumonectomy group. Though the right cardiac afterloads of lobectomy, double lobectomy and pneumonectomy groupa all increase significantly post-operativlye, only the former recover to pre-operative level 1 month after surgery.     

米非司酮对妊娠中期胎儿心脏超微结构的影响

目的:探讨米非司酮对妊娠中期胎儿心脏超微结构的影响。方法:将计划引产孕妇随机分为两组:对照组(水囊组)10例,实验组(米非司酮+水囊)15例。实验组按孕龄分为实验Ⅰ组(10例,16~22周),实验Ⅱ组(5例,23~28周)。实验组口服米非司酮100mg,连服3天,行水囊引产,对照组只行水囊引产。胎儿娩出后取心肌组织进行样本制备,然后在电镜下观察组织的超微结构。结果:细胞肿胀、空化,细胞膜不完整,闰盘分离,部分细胞连接消失。细胞核多呈不规则形,核内染色质凝聚呈块状,部分细胞核空化,核周围可见脂褐素。大部分肌丝断裂,肌节结构消失,少数可辩残留肌节结构,其间可见少量核糖体,但各带结构不清。线粒体肿胀,高度空化,嵴断裂,细胞基质局部空化。毛细血管内皮细胞肿胀。心肌组织细胞的超微结构有改变,且孕龄越小,超微结构改变越明显。结论:米非司酮可以引发胎儿心脏的缺血缺氧性改变。     

Cytochrome c mRNA levels decrease in senescent rat heart.

The concentration of mitochondria decrease in the heart as rodents age from maturity to senescence. The reason for this change is not known. One purpose of the present study was to determine if cytochrome c mRNA, representative of proteins of the inner mitochondrial membrane, decreased in the hearts of Fischer 344 rats as they aged from 12 to 24 months. Twenty-two percent less cytochrome c mRNA existed per given quantity of extracted RNA from the heart in 24-month-old rats as compared with the 12-month-old group. No change in the quantities of cardiac -actin mRNA, Ca²⁺/calmodulin protein kinase II mRNA or 18S rRNA was noted between 12- und 24-month-old hearts. Thus, the decrease in cytochrome c mRNA suggests that decreased in mRNAs for proteins of the inner mitochondrial membrane could play some role in the diminished concentration of mitochondria that exists in the senescent heart.     

急性心肌缺血时红细胞变形性的变化及其机理

本实验观察了犬急性心肌缺血时体循环血与缺血区局部静脉血中红细胞变形性（ＲＣＤ）的变化。结果表明，阻断冠脉血流后高切变率下全血粘度（ηｂｈ）和红细胞刚性指数（ＥＲＩ）明显增高，而缺血区局部血液中此二者的变化明显大于体循环静脉血。事先切断内脏大神经，可使阻断冠脉后体循环血（而不是局部静脉血）的ηｂｈ和ＥＲＩ变化基本消失。缺血区局部血液ｐｈ和ｐＯ２明显降低，ｐＣＯ２明显增高，红细胞内ＡＴＰ含量减少和钙含