舒芬太尼延迟性预处理对心肌缺血再灌注损伤及Caspase-3的影响

目的 探讨舒芬太尼延迟性预处理对大鼠心肌缺血再灌注损伤及Caspase-3表达的影响.方法 健康成年Wistar大鼠90只,随机均分为3组:假手术组(S组)、心肌缺血再灌注组(L/R组)、舒芬太尼组(SF组).每组又按再灌注时间30 min(T1)、60 min(T2)和120 min(T3)分为3个组,每组各10只.缺血再灌注24 h前,S组、I/R组输注生理盐水20ml,SF组输注含舒芬太尼5μg/kg生理盐水20ml.S组仅开胸,分离冠状动脉但不夹闭.I/R组、SF组采用夹闭左冠状动脉前降支40 min后再灌注的方法制备心肌缺血再灌注模型.分别于再灌注30、60、120 min处死实验动物.测定缺血再灌注各时相心肌肌钙蛋白I(cTnI)、Caspase-3含量、凋亡指数(AI),电镜下观察心肌超微结构.结果 缺血再灌注可导致cTnI、Caspase-3、AJ值升高,心肌超微结构发生病理学改变,舒芬太尼延迟性预处理可减弱上述改变(P<0.05).结论 舒芬太尼延迟性预处理可能通过调节Caspase-3表达抑制细胞凋亡,对大鼠缺血再灌注心肌产生保护作用.     

烟碱预先给药对心肌缺血再灌注大鼠心功能的影响

目的 评价烟碱预先给药对心肌缺血再灌注大鼠心功能的影响.方法 健康成年雄性SD大鼠60只,体重200 ～ 250 g,采用随机数字表法,将其分为3组(n=20)∶假手术组(S组)、心肌缺血再灌注组(IR组)和烟碱预先给药组(N组).S组丝线穿过冠状动脉前降支但不结扎；IR组采用丝线结扎左冠状动脉前降支30 min后再灌注120 min的方法制备大鼠心肌缺血再灌注模型.N组结扎前30 min,经右颈静脉注射烟碱400μg/kg,余操作同IR组,S组和IR组右颈静脉注射等量生理盐水.各组随机取10只大鼠于缺血前(T0)、缺血30 min(T1)和再灌注30 min(T2)、120 min(T3)时经生物机能实验系统记录左心室收缩压(LVSP)、左心室舒张压(LVDP)、左室内压上升/下降最大变化速率(±dp/dtmax)、HR和MAP.各组其余10只大鼠于再灌注60 min时采集右颈动脉血样,采用ELISA法测定血浆肌酸激酶同工酶(CK-MB)活性、心肌肌钙蛋白I(cTnI)和TNF-α浓度.结果 与S组比较,IR组T23时MAP和LVSP、T13时HR、LVDP和±dp/dtmax降低,血浆CK-MB活性、cTnI和TNF-α浓度升高,N组T1-2时LVDP、T1-3时HR和±dp/dtmax降低,血浆CK-MB活性、cTnI和TNF-α浓度升高(P＜0.05)；与IR组比较,N组T3时MAP、HR、LVSP、LVDP和±dp/dtmax升高,血浆CK-MB活性、cTnI和TNF-α浓度降低(P＜0.05).结论 烟碱预先给药通过激活胆碱能抗炎通路,抑制炎性反应,可显著减轻大鼠心肌缺血再灌注损伤,从而改善心功能.     

不同时点应用维拉帕米对心肌缺血再灌注损伤的保护作用

目的 观察不同时点应用维拉帕米(VP)对大鼠心肌缺血再灌注损伤的保护作用,并探讨其心肌保护的作用机制.方法 建立大鼠心肌缺血再灌注模型,将18只雄性SD大鼠随机分为3组,每组6只.Verapamil-1组于结扎前10 min开始泵入维拉帕米稀释液(0.25 mg/kg),Verapamil-2组于再灌前10 min开始泵入维拉帕米稀释液(0.25 mg/kg),IR组于结扎前10 min开始泵人生理盐水(2ml/kg).再灌注后60min处死大鼠.检测血清肌钙蛋白T(cTnT)含量、缺血区心肌组织Caspase-3表达水平;组织形态学分析心肌损伤程度.结果　Verapamil-1组血清cTnT含量、心肌组织Caspase-3表达量(4.60±1.12)ng/L,(39.51±5.01)%较IR组(7.70±1.31)ng/L,(51.10±5.30)%和Verapamil-2组(7.23±1.03)ng/L,(49.35±4.95)%明显降低,差异有统计学意义(P＜0.05);Verapamil-2组血清cTnT含量、心肌组织Caspase-3表达水平和IR组比较差异无统计学意义(P＞0.05);Verapamil-1组心肌组织形态学损伤程度较IR组和Verapamil-2明显降低,差异有统计学意义(P＜0.05);Verapamil-2组心肌组织形态学损伤程度和IR组比较差异无统计学意义(P＞0.05).结论　结扎前10 min开始给予维拉帕米对心肌缺血再灌注损伤有明显保护作用,再灌注前10 min开始给予维拉帕米对心肌缺血再灌注损伤无保护作用.

Abstract：

Objective To investigate the effect of verapamil administered at different time points on myocardial ischemia-reperfusion injury in rats, and explore the mechanism of myocardial protection.Methods The model of myocardial ischemia reperfusion in rats was established and 18 male SD rats were randomly divided into 3 groups,n =6 each. Verapamil dilution (0. 25 mg/kg) was pumped into verapamil1 group 10 min before ischemia, and verapamil dilution (0. 25 mg/kg) was pumped into verapamil-2 group 10 min before reperfusion. Normal saline (2 ml/kg) was pumped into IR group 10 min before ischemia.Rats were killed 60 min after reperfusion. The levels of serum cardiac Troponin T (cTnT) and the expression of myocardial Caspase-3 were evaluated. Histomorphological methods were used to analyze the extent of myocardial injury. Results The levels of serum cTnT and the expression of myocardial Caspase-3 in verapamil-1 group (4.60 ± 1.12) ng/L, (39.51 ±5.01)% were significantly lower than those in IR group (7. 70 ± 1.31 ) ng/L, (51.10 ±5. 30)% and verapamil-2 group (7. 23 ± 1.03) ng/L, (49. 35 ±4. 95 ) % ( P ＜ 0. 05 ). The levels of serum cTnT and the expression of myocardial Caspase-3 had no significant difference between verapamil-2 group and IR group (P ＞ 0. 05 ). The extent of myocardial injury in verapamil-1 group was significantly lower than that in IR group and verapamil-2 group (P ＜ 0. 05 ). The extent of myocardial injury had no significant difference between verapamil-2 group and IR group (P ＞0. 05). Conclusion Starting from 10 min before ischemia, verapamil has protective effects on myocardial ischemia/reperfusion injury. Starting from 10 min before reperfusion, verapamil does not provide protection on myocardial ischemia reperfusion injury.     

温血停搏液术终灌注对缺血再灌注心肌线粒体功能的影响

利用猫体外循环模型观察心肌缺血后温血停搏液再灌注对线粒体功能的影响。结果发现，心肌缺血６Ｏｍｉｎ时，线粒体功能呈现下降趋势，但与正常组相比，相差不显著。单纯再灌注组恢复正常血供６０ｍｉｎ后，线粒体功能进一步下降，同正常组或缺血组相比，相差非常显著。而温血停搏液再灌注可保护线粒体功能，同单纯再灌注组相比，两者相差显著表明心肌急性缺血后温血停搏液再灌注可减轻心肌线粒体再灌注损伤。     

异丙酚对急性心肌梗死大鼠心脏功能的影响

目的 观察异丙酚对急性心肌梗死大鼠血液动力学影响的量-效关系以及心肌梗死范围和心肌超微结构的变化。方法 将急性心肌梗死模型的大鼠随机分为5组（n=8）,对照组（Ⅰ）,其余大鼠分别持续静脉输注30（Ⅱ）、45（Ⅲ）、60（Ⅳ）、75（Ⅴ）mg·kg-1·h-1异丙酚30min。测定输注异丙酚30min血药浓度,观察血液动力学、心肌梗死范围和心肌超微结构的变化。结果 血药浓度为（3.4±0.9）～（12.9±2.4）μg/ml时,平均动脉压（MAP）、心率（HR）、左室收缩压（LVSP）、左室内压力变化最大速率（±dp/dtmax）、心肌耗氧指数（MOCI）均呈剂量依赖性下降（P<0.05）,左心室舒张末压（LVEDP）无明显变化（P>0.05）,心肌梗死面积为23.7％～29.2％（P>0.05）,心肌超微结构无显著性差异。结论 在血药浓度（3.4±0.9）～（12.9±2.4）μg/ml范围内,异丙酚对血液动力学及心收缩功能呈剂量依赖性抑制,对心肌梗死范围和心肌细胞超微结构无明显影响。     

The effect of sirolimus on sex hormone levels of male renal transplant recipients

BACKGROUND: It is unclear whether sirolimus, a newer immunosuppressive agent, widely used in renal transplantation, affects male sex hormone levels or sexual function. METHODS: Sex hormone profiles in male renal transplant recipients were obtained and compared between a sirolimus-treated group and a group not on sirolimus in a cross-sectional study. Both groups also completed a sexual dysfunction questionnaire. RESULTS: Sixty-six subjects were evaluated, 32 in the sirolimus group and 34 in the control group. Total testosterone level was significantly lower in the sirolimus group than the control group (393.3 +/- 188 vs. 537.4 +/-232 pg/mL; p = 0.08) while follicle stimulating hormone and luteinizing hormone levels were significantly higher in the sirolimus group (12.8 +/- 14 vs. 6.0 +/- 5, p = 0.013; 10.9 +/- 14 vs. 4.7 +/- 4, p = 0.018, respectively). There was a significant negative correlation between 24-h sirolimus trough and total testosterone levels (p < 0.03). By multiple regression analysis, use of sirolimus was independently associated with decreased total testosterone level. There was no significant difference in subjective sexual dysfunction as assessed by questionnaire scores between the two groups. There was no correlation between questionnaire scores and total testosterone level. CONCLUSION: Sirolimus is associated with decreased total testosterone levels in male renal transplant recipients. It is unclear whether sirolimus may affect other aspects of sexual function.     

MR T2 mapping成像评估介入栓塞法制备的急性心肌缺血模型心肌组织特征

目的探讨MR T2 mapping成像评估介入栓塞法制备的急性心肌缺血模型心肌组织特征的可行性。方法对15头健康成年贵州小型猪以介入栓塞法制备急性心肌缺血模型,测量并对比建模前后左心室心肌T2值。结果 13头建模成功,建模成功率86.67%(13/15)。建模前左心室心底、心中、心尖部心肌T2值总体差异无统计学意义(P=0.70);建模后总体差异有统计学意义(P0.01),心底部心肌T2值小于心中及心尖部(P均0.01),心中、心尖部差异无统计学意义(P0.05)。建模后心中、心尖部心肌T2值均大于建模前(P均0.01),建模前后心底部心肌T2值差异无统计学意义(P0.05)。结论采用介入栓塞法建立急性心肌缺血模型的成功率较高;利用MR T2 mapping成像可对模型心肌缺血水肿程度进行定量分析。     

A novel testosterone gel formulation normalizes androgen levels in hypogonadal men,with improvements in body composition and sexual function

OBJECTIVE: To compare the safety and efficacy of two doses of a new testosterone gel formulation (Testim Auxilium Pharmaceuticals, Inc., Norristown, PA, USA) to a permeation-enhanced testosterone patch (Andropatch), GlaxoSmithKline, UK) for treating men with confirmed low serum testosterone levels, and associated signs and symptoms of hypogonadism. PATIENTS AND METHODS: In all, 208 men were randomized and treated at 29 centres in Denmark, Germany, Netherlands, Sweden and the UK. The men were treated for 90 days, and the pharmacokinetics and treatment effectiveness of Testim at two doses (50 and 100 mg/day, delivering a daily dose of 5 and 10 mg testosterone, respectively) and Andropatch (2 x 2.5 mg patches, each delivering 2.5 mg testosterone and containing 12.2 mg of testosterone) were compared. Pharmacokinetic profiles were obtained, body composition measured, and mood and sexual function data recorded. RESULTS: Testim produced dose-dependent improvements in all pharmacokinetic variables compared with Andropatch. The mean increases from baseline to 90 days in testosterone were 12.41, 6.54 and 3.82 nmol/L for Testim 100 and 50 mg/day and the Andropatch, respectively. Both doses of Testim significantly improved positive and negative mood over baseline; Andropatch did not. All three treatments increased lean body mass, and the higher dose of Testim produced a significant decrease in percentage body fat. At all sample times both doses of Testim significantly improved sexual performance, sexual motivation, sexual desire and spontaneous erections. Andropatch provided insignificant improvements from baseline at all sample times for sexual desire, an inconsistent improvement in sexual motivation, but no effect on spontaneous erections. These results are similar to those previously reported for testosterone replacement therapy in hypogonadal men, suggesting that normalization of serum testosterone restores sexual function. However, the present data suggest that higher serum testosterone levels may further improve sexual function. Gel treatment was well tolerated, while patch treatment produced higher rates of application-site reactions and study discontinuation. CONCLUSION: The favourable pharmacokinetic profile and treatment outcome, combined with the enhanced tolerability of Testim, suggest that this new gel formulation is a safe and effective treatment in men with low serum testosterone levels and associated signs and symptoms of hypogonadism.     

盐酸戊乙奎醚后处理对心肌缺血-再灌注大鼠心功能的影响

目的探讨盐酸戊乙奎醚后处理对心肌缺血-再灌注(IR)大鼠心功能的影响。方法选择SPF级健康雄性Wistar大鼠32只,8周龄,体重220~250 g。将大鼠随机分为四组:假手术组(S组)、假手术+盐酸戊乙奎醚组(SP组)、IR组和IR+盐酸戊乙奎醚后处理组(IP组),每组8只。S组冠状动脉左前降支仅穿线不结扎,30 min后经尾静脉注射生理盐水1 mg/kg。SP组冠状动脉左前降支仅穿线不结扎,30 min后经尾静脉注射盐酸戊乙奎醚1 mg/kg。IR组冠状动脉左前降支穿线结扎30 min后,松开结扎线,再灌注3 h。于再灌注(松开结扎线)前即刻经尾静脉注射生理盐水1 mg/kg。IP组于再灌注前即刻经尾静脉注射盐酸戊乙奎醚1 mg/kg。于开胸前5 min、再灌注后3、6 h,采用经胸超声心动图监测大鼠左心室舒张末压(LVEDP)、左心室收缩末压(LVESP)、左心室射血分数(LVEF)、左心室缩短分数(LVFS),采用智能血压计监测大鼠尾动脉MAP,采用ELISA法检测血清肌钙蛋白T(cTnT)浓度。结果与开胸前5 min比较,再灌注后3、6 h IR组和IP组LVEDP明显升高,LVESP、LVEF、LVFS、MAP明显降低(P<0.05);再灌注后3、6 h S组、IR组和IP组血清cTnT浓度明显升高(P<0.05)。与再灌注后3 h比较,再灌注后6 h IR组LVEDP、血清cTnT浓度明显升高,LVESP、LVEF、LVFS、MAP明显降低(P<0.05)。与S组比较,再灌注后3、6 h IR组和IP组LVEDP、血清cTnT浓度明显升高,LVESP、LVEF、LVFS、MAP明显降低(P<0.05)。与IR组比较,再灌注后3、6 h IP组LVEDP、血清cTnT浓度明显降低,LVESP、LVEF、LVFS、MAP明显升高(P<0.05)。S组和SP组上述指标差异均无统计学意义。结论盐酸戊乙奎醚后处理能够维持血流动力学稳定,降低cTnT浓度,改善心肌缺血-再灌注大鼠的心功能。     

Intravenous transplantation of mesenchymal stem cells improves cardiac performance after acute myocardial ischemia in female rats

Mesenchymal stem cells (MSCs) are potential sources of cells for tissue repairing. However, little information is available regarding the therapeutic potency of intravenously transplanted MSCs for myocardial ischemia (MI). In the present study, MSCs were isolated from bone marrow of male rats and expanded in vitro. Three hours after ligation of left anterior descending artery, the transplanted group received an infusion of MSCs through the tail vein. At the same time, a coronary-ligated control group was injected with culture medium. Homing of MSCs to the heart was assessed by expression of the Y chromosome sry gene using fluorescent in situ hybridization (FISH). At 1 week or 8 weeks after transplantation, sry positive cells were present in cardiac tissue in the transplanted group, but not in the hearts of control group. Cardiomyocytes, smooth muscle cells, and endothelial cells that bore sry gene were identified in transplanted group at 8 weeks after transplantation. Ultrastructural observation revealed that a large number of capillary and some immature myocytes were found to survive in the ischemia region. MSCs transplantation also decreased LVEDP pressure and -dP/dt, but increased LVSP and +dP/dt. The cardiac infarct size was significantly smaller in transplanted group than in control group. Our data suggest that intravenously transplanted MSCs improve cardiac performance and promote the regeneration of blood vessels and cardiomyocytes.     

风湿性心脏瓣膜病患者心脏功能与肺功能关系的临床研究

目的 探讨风湿性心脏病患者心脏功能与肺功能的相互关系,以指导临床治疗。方法 对９８例风湿性心脏病患者术前,术后近期,术后远期的肺功能检查及运动前后血气检测,以及根据心脏功能级别,心胸比率大小进行临床对比。结果 随心脏功能的降低,心胸比率的增大,肺功能损害逐渐加４重,运动前动脉氧分压及血氧饱和度与心脏功能关系不大,而运动后氧分压多数较运动前降低,血氧饱和改变不大,术后近期肺功能改善不明显,术后远期随     

异丙酚预处理对大鼠离体心脏缺血再灌注时心肌线粒体的影响

目的 探讨异丙酚预处理对大鼠离体心脏缺血再灌注时心肌线粒体的影响.方法 成年雄性SD大鼠60只,体重250～300 g,随机分为5组(n=12):对照组(Con组)、缺血再灌注组(I/R)和不同浓度异丙酚组(P1组、P2组、P3组).采用Langendorpf离体心脏灌注模型,用K-H液平衡20 min后,Con组继续用K-H液灌注130 min;I/R组用K-H液灌注40 min,缺血30 min,再灌注60 min;P1组、P2组、P3组于缺血前分别用含50、100、150 μmol/L异丙酚的K-H液灌注10 min,再用K-H液冲洗10 min,该过程总共进行2次为预处理,预处理后各组处理均同I/R组.记录平衡20 min(基础值)、缺血前即刻、再灌注60 min的心率(HR)、左心室舒张末压(LVEDP)、左心室发展压(LVDP)、左心室压力上升及下降速率最大值(±dP/dtmax)、冠脉流量(CF).于再灌注60 min时测定心肌梗死面积以及线粒体电子传递链Ⅰ复合体活性.结果 与Con组比较,再灌注60 min时I/R组LVEDP升高,HR、LVDP、±dP/dtmax、CF均下降,P2组和P3组LVEDP升高,I/R组和P1组心肌梗死面积增大,I/R组、P1组、P2组和P3组线粒体电子传递链Ⅰ复合体活性降低(P＜0.05);与I/R组比较,P2组及P3组再灌注60 min时LVEDP降低,HR、LVDP、±dP/dtmax、CF均升高,P2组及P3组心肌梗死面积减小,P2组和P3组线粒体电子传递链复合体Ⅰ活性升高(P＜0.05).结论 100、150μmol/L异丙酚预处理通过增加心肌线粒体电子传递链复合体Ⅰ的活性,在一定程度上减轻大鼠心肌缺血再灌注损伤.     

Relationship between serum testosterone and sex hormone-binding globulin in adult men with intact or absent gonadal function

Serum levels of testosterone and sex hormone-binding globulin (SHBG) were determined in 80 apparently healthy men aged 25-85 years and in 23 patients with prostatic carcinoma (CAP) aged 60-75 years before and 6 months after orchidectomy. Serum levels of testosterone and SHBG were correlated positively in healthy men, in all subjects overall as well as within different age groups, and in CAP patients before, but not after, orchidectomy. These data are not consistent with the classical theory regarding SHBG regulation and also speak against an influence of SHBG binding on testosterone metabolism as a mechanism behind the observed positive association between testosterone levels and SHBG.     

Effects of acute isovolemic hemodilution and anesthesia on regional function in left ventricular myocardium with compromised coronary blood flow

The effects of progressive, isovolemic hemodilution using Dextran 70 and the effect of halothane (0.7, 0.9, 1.1, and 1.3% end-tidal, administered randomly at each level of hemodilution) on global cardiovascular and regional LV contractile functions were investigated in 24 dogs with induced critical constriction of the left anterior descending coronary artery (LAD). Two additional groups of six dogs each (with and without LAD stenosis) not undergoing hemodilution served as time controls. Regional LV contractile function was assessed by sonomicrometry in the flow-compromised apical LAD territory, as well as in three non-compromised LV areas supplied by the left circumflex coronary artery. Regional myocardial function was found to be stable throughout the study period of 4-5 h in both time control groups. Mean arterial and coronary perfusion pressures as well as LV dP/dtmin decreased (P < 0.01) during hemodilution. LV dP/dtmax remained unchanged, and heart rate and LVEDP increased slightly (P < 0.05). Systolic shortening (SS) in the LAD territory was unchanged at a hematocrit (HCT) of 33.5 +/- 0.3% (mean +/- s.e. mean), and decreased marginally at an HCT of 24.2 +/- 0.1% (SS of 17.4 +/- 1.0% as compared to 20.2 +/- 1.6% at critical constriction (CC), P < 0.05). No increase in post-systolic shortening (PSS) occurred in the compromised area. Severe LAD dysfunction was observed in the LAD territory at an HCT of 14.9 +/- 0.1%, as systolic shortening decreased (11.8 +/- 1.1%, P < 0.01 vs CC) and PSS increased (31.2 +/- 3.4%, P < 0.01 vs CC). The effects of hemodilution on global cardiovascular and regional myocardial functions were unaffected by halothane.(ABSTRACT TRUNCATED AT 250 WORDS)     

七氟醚预处理对急性心肌缺血再灌注损伤大鼠认知功能的影响

目的 探讨七氟醚预处理对急性心肌缺血再灌注损伤大鼠认知功能的影响.方法 健康SD大鼠60只,雌雄各半,体重300～350 g,随机分为4组:正常对照组(C组,n=6),假手术组(S组,n=18)仅挂线不结扎左冠状动脉;急性心肌缺血再灌注组(IR组,n=18)结扎左冠状动脉30 min后恢复再灌注;七氟醚预处理组(SP组,n=18)吸入七氟醚1.0 MAC 60 min,停止吸入七氟醚后60 min结扎左冠状动脉,缺血30 min后恢复再灌注.分别于左冠状动脉结扎前(T1)、缺血30 min(T2)及再灌注120 min(T3)时抽取股动脉血1 ml,测定血浆丙二醛(MDA)浓度和超氧化物歧化酶(SOD)活性.C组随机取3只大鼠,其余各组于再灌注1、3、7 d各随机取3只大鼠测定海马长时程增强(LTP),C组取另外3只大鼠,其余各组于上述时点随机取3只大鼠,测定海马肿瘤坏死因子α(TNF-α)、TNF-α mRNA、白细胞介素1β(IL-1β)、IL-1β mRNA、血红素氧合酶(HO)-1的表达水平.结果 与C组和S组比较,IR组和SP组LTP降低;与IR组比较,SP组LTP升高(P＜0.05).与C组比较,IR组和SP组HO-1、IL-1β mRNA、IL-1β、TNF-α mRNA表达上调;与S组比较,IR组和SP组IL-1β mRNA及IL-1β表达上调;与IR组比较,SP组TNF-α mRNA、HO-1、IL-1β mRNA及IL-1β表达下调,血浆MDA浓度降低,SOD活性升高(P＜0.05).结论 七氟醚预处理可改善急性心肌缺血再灌注损伤大鼠认知功能,其机制可能与下调TNF-α、IL-1β表达有关.     

Ro-54864对缺血/再灌注心肌功能和线粒体的保护作用

目的 利用Langendorff离体灌注模型探讨Ro-54864对缺血/再灌注心肌功能和线粒体的保护作用.方法 大鼠心脏上架平衡20min后,随机分为5组.假手术组:持续灌注115min;对照组:续灌10min,缺血25min,复灌60min;Ro(Ro-54864)组:缺血前灌注含0.1μmol/L Ro-54864的K-H液10 min;苍术苷(atractyloside,ATR)组:缺血前灌注含20 μmol/L苍术苷的K-H液10 min;ATR+Ro组:缺血前灌注含20 μmol/L苍术苷和0.1 μmol/L Ro-54864的K-H液10 min.分别在平衡20min、缺血前、复灌15 min、60 min记录左室力学指标.在复灌注末,用氯化三苯基四氮唑染色法(TTC)测定心肌梗死面积百分比;分离浆膜下线粒体,电镜下观察线粒体的形态和结构,并进行评分.结果 再灌注15 min后,Ro组的冠脉流量(CF)和血流动力学指标(LVDP,dp/dtmax,dp/dtmin)明显高于对照组和其它处理组,而ATR组的各指标低于对照组(P＜0.05).与对照组(41%±3%)比较,再灌注末期Ro组(28%±3%)心肌梗死面积明显减少(P＜0.05),而ATR组(51%±2%)的梗死面积明显增大(P＜0.05).Ro组(1.51±0.24)心肌线粒体损伤比对照组(2.21±0.27)明显减轻(P＜0.05),而ATR组(3.23±0.36)线粒体损伤较对照组严重(P＜0.05).ATR+Ro组的各项指标与对照组比较无统计学差异.结论 外周苯二氯(卓)受体(peripheral benzodi azepine receptor,PBR)激动剂Ro-54864能够明显减少缺血心肌的梗死面积,保护线粒体,增加冠脉流量,促进缺血心肌功能恢复.线粒体通透性转换孔开放剂苍术苷减弱Ro-54864的心肌保护作用.     

Effects of direct mechanical ventricular assistance on regional myocardial function in an animal model of acute heart failure

Direct mechanical ventricular assistance (DMVA) improves hemodynamics in failing hearts without complications associated with a blood/device interface. Epicardial Doppler displacement transducers provide exact measurements of tissue displacement and regional myocardial function (RMF). An in vivo porcine model of acute heart failure was used to examine the effects of DMVA on RMF, which have not been reported before. In 8 anesthetized pigs cardiac output (CO), left ventricular pressure (LVP), aortic blood pressure (BP), systolic contractility (dp/dt max), and systolic wall thickening fraction (WT%) were measured. A multichamber pump system (IMPS) surrounding the left ventricle was implanted and the measurements were repeated. Then acute heart failure was induced by beta-blockade, resulting in a decline of all measured parameters to more than 30% compared to baseline values. In the further course of the experiment, repeated measurements were taken at several intervals with and without DMVA by the implanted device. The IMPS implantation caused no significant hemodynamic changes. Under conditions of acute heart failure DMVA improved LVP (46 +/- 7 to 81 +/- 9 mm Hg), dp/dt max (532 +/- 207 to 744 +/- 361 mm Hg/s), CO (1.5 +/- 0.1 to 1.9 +/- 0.5 L/min) and WT% (19 +/- 7% to 32 +/- 8%). Left ventricular myocardium not directly assisted by external pressure application showed improved regional myocardial function during DMVA. We conclude that DMVA is capable of improving hemodynamics due to extrinsic compression. It also enhances the remaining myocardial function of the failing heart, which might lead to myocardial recovery. These synergistic effects are considered responsible for the high efficiency shown by the IMPS in previous investigations.     

Difficulties in measuring the effect of testosterone replacement therapy on muscle function in older men

Muscle wasting in older men may be related to androgen deficiency. We have assessed the effect of testosterone replacement therapy on muscle function in the upper and lower limbs of older (age > 60 years) men with blood testosterone levels < 14 nmol/L. Subjects (n = 7 per group) received testosterone enanthate 200 mg i.m. or placebo every 2 weeks in a double blind study over a 12-week period and underwent muscle testing every 4 weeks. A significant increase in blood levels of testosterone and a reduction in levels of sex hormone binding globulin occurred in the treatment group. Total body mass, haemoglobin and packed cell volume also increased significantly (p < 0.05). No improvements in handgrip strength, isometric strength of knee flexors and extensors or leg extensor power were seen in either group. Wide variability in all measures of muscle function were observed in these elderly men suggesting that very large study groups would be required to determine potential treatment benefits on muscle function.     

The effect of myocardial preservation technique on supraventricular tachycardia following aortic valve replacement

We studied 100 patients who underwent an isolated aortic valve replacement (AVR) between 1974 and 1991. The patients were divided into the following two groups and compared: group A, which consisted of 40 patients operated on before 1978 who underwent continuous left coronary perfusion with blood; and group B, which consisted of 60 patients operated on after 1979 in whom St. Thomas solution was used in combination with topical cardiac cooling. Moreover, we divided the group B patients into two subgroups: group Bl, who underwent AVR before 1986 during which we administered St. Thomas solution with ice slush every 30 min; and group B2, who had AVR after 1986 in which we used St. Thomas solution with a cold saline (4°C) solution and treated with a small amount of slushed ice every 15 min. The incidence of supraventricular tachycardias was 15% in group A, 50% in group BI, and 15% in group B2. The severity of preoperative New York Heart Association (NYHA) functional class, the type of valve lesions, cardiothoracic ratio, left ventricular function, aortic clamp time, bypass time, and use of drugs did not correlate with the incidence of supraventricular tachycardias in either group A or B. In group B2 patients, we paid a lot of attention to cooling the right atrium as well as the left ventricle by immersing the whole heart using a 4°C saline solution, which led to a remarkable reduction of the incidence of supraventricular tachycardia. This fact indicates that right atrial preservation is one of the most important factors for reducing the incidence of supraventricular tachycardia.