缬草单萜氧化物对单个兔心室肌细胞钠通道的影响

利用全细胞膜片钳记录技术研究缬草单萜氧化物 (VMO)对兔单个心室肌细胞钠离子电流 (INa)的影响。结果 :30 μg/L和 6 0 μg/L的VMO使兔心室肌细胞INa峰值 (INamax)从 5 3.4 7± 5 .1 3pA/pF分别降至 4 0 .2 5± 4 .1 8pA/pF和 30 .89± 2 .95pA/pF(n =8,P <0 .0 5和P <0 .0 1 ) ,抑制率分别为 2 4 .7%和 4 1 .9% ;VMO使INa的电流 电压曲线上移 ,但不改变其激活电位、电位峰值和反转电位 ;VMO还减慢钠通道灭活后的恢复过程。结论 :VMO对INa具有浓度依赖性阻滞作用 ,这可能是其抗心律失常的重要机制之一。     

缬草单萜氧化物对兔单个心室肌细胞L-型钙电流的影响

利用全细胞膜片钳记录技术研究30μg/L和100μg/L缬草单萜氧化物(VMO)对兔单个心室肌细胞L型钙电流(ICaL)和动作电位的影响。结果:30μg/L和100μg/L的VMO使兔心室肌细胞ICaL峰值由6.04±0.59pA/pF分别减至3.99±0.31pA/pF和2.31±0.24pA/pF(n=8,P<0.01);VMO使ICaL的电流电压曲线上移,但不改变其激活电位、电位峰值和反转电位;VMO还使钙电流失活曲线左移。30μg/LVMO可使动作电位时程(APD)明显缩短,APD50和APD90分别缩短了50.3%和29.6%(n=16,P<0.05),而静息电位和动作电位幅值无明显改变。结论:VMO对LCaL具有浓度依赖性阻滞作用。这可能是其对心血管作用的重要机制之一。     

褪黑激素对大鼠体外供心延时保存效果的作用研究

目的:探讨褪黑激素对大鼠供心延时保存效果的作用。方法:将 64 只 Wistar大鼠随机分为对照组和实验组。对照组:供心单用St Thomas液4℃保存;实验组:用含褪黑激素(0.1 mmol/L)的St Thomas液4℃保存。分别于保存前及保存6,12,24 h后,取出供心,在改良的非循环式Langendorff Neely灌注模型上测定血流动力学指标。高效液相色谱法测心肌细胞线粒体ATP水平。原位末端标记法(TUNEL)检测细胞凋亡,计算心肌细胞凋亡指数(AI)。电镜观察心肌超微结构。结果:实验组左心功能恢复、心肌超微结构、线粒体 ATP水平等均明显优于对照组(P<0.01)。实验组各时间点心肌细胞 AI明显小于相应对照组(均 P<0.01)。结论:褪黑激素增补于供心保存液中可明显改善体外供心延时保存效果,机制可能与其减少心肌细胞凋亡有关。     

阿片预处理对兔供心保存的保护作用

目的　观察DADLE(D 丙 2 ,D 亮 5 脑啡肽 )预处理对兔供心的保存效果及保护机制。方法　 2 4只成年家兔随机分为A、B两组 ,每组 12只 ,供心原位心脏冷停液灌注 ,切取后用 4℃Krebs Henseleit(K H)保存液保存 4h。B组供心在获取前给予DADLE预处理。保存后行腹腔异位心脏移植术 ,观察供心功能恢复情况。 2h后处死受体动物 ,切除移植心脏 ,测心肌组织中活性氧含量及钠 钾ATP酶活性 ,电镜观察心肌超微结构改变。结果　B组和对照组相比有较好的心功能恢复 (P <0 0 5 ) ;B组钠 钾ATP酶活性好于A组 (P <0 0 5 ) ,活性氧含量明显高于A组 (P <0 0 0 1)。心肌超微结构损伤较A组轻。结论　阿片预处理结合低温对兔供心保存有明显的保护作用 ,其机制可能与其对线粒体结构保护良好及诱导自由基产生有关     

供肺保存的研究现状

供肺保存是肺移植领域中亟待解决的重大课题。近年来供肺保存的研究取得了一定的进展，本文从保存液、保存条件及辅助措施三方面予以总结。     

9例犬供心超长时间保存后行原位心脏移植体外循环的管理

目的总结9例犬供心超长时间保存后行原位心脏移植的体外循环管理经验。方法供体心脏以冷UW液（3例）或自制保存液（6例）灌注停跳、摘取心脏后保存24 h;在全麻下以标准法或双腔静脉法术式行犬原位心脏植入,体外循环均采用浅低温中流量、中度血液稀释法,以移植心脱离体外循环后,血流动力学稳定（窦性心律、心率≥90次/m in、平均动脉压≥90 mmHg,1 mmHg=0.133 kPa）4 h为手术成功。结果全组体外循环过程顺利,体外循环总时间（180±30）min,升主动脉阻断时间为（130±20）min,后并行时间（60±10）min,供心热缺血时间030 s、冷缺血时间（24±0.5）h。主动脉开放后,3例移植心自动复跳,4例移植心电击复跳,移植心复跳受者手术均成功。死亡2例为实验早期手术操作技巧不当所致。结论除良好的供心保护外,良好的体外循环管理亦是犬心脏移植成功的关键。     

供肺保存的研究现状

供肺保存是肺移植领域中亟待解决的重大课题。近年来供肺保存的研究取得了一定的进展,本文从保存液、保存条件及辅助措施三方面予以总结。     

犬温血持续灌注不停跳供心长时间保存效果观察

目的：观察犬温血持续灌注不停跳供心长时间保存的效果。方法成年犬7只,其中5只作为实验犬（供心1～5）,2只作为对照犬（供心6、7）。供心1～5采用温血持续灌注不停跳保存,供心6、7采用冷停跳灌注保存;计算供心保护6 h时的质量增长率,化学发光法检测供心血肌钙蛋白I（TnI）,检查供心左心室收缩舒张功能。结果供心1跳动2h后出现室颤终止实验,供心2～5跳动直至8h至实验结束。保护6h时,供心2～7质量增长率分别为10．00％、17．59％、7．94％、14．08％、22．00％、21．10％;供心6、7血TnI自2 h后较供心2～5显著升高（P均＜0．05）,供心2～5之间比较,差异没有统计学意义（P均＞0．05）;供心2～5左心室收缩及舒张功能随时间延长而下降,供心间比较,差异没有统计学意义（P均＞0．05）。结论犬温血持续灌注不停跳供心可较长时间保存。     

肺移植术的供肺保存研究现状

肺移植术是治疗终末期肺疾病的有效方法，而供肺的保存技术关系到肺移植术的成败。而且，这已成为近10年来肺移植研究的焦点。本文就肺移植术中供肺保存的相关问题作一综述。     

肝移植研究进展——肝移植供肝的获取和保存

肝移植手术的最关键一步是获取新鲜健康 ,动静脉及胆管管道完备 ,且经过保存后能恢复良好功能的供体肝脏。供肝的选择、切取、保存、修整技术对于移植术后移植肝的存活、功能恢复及术中术后并发症的发生有至关重要的影响。1　供体的选择供移植用的肝脏可来自活体或尸体。活体主要是指有血缘关系的亲属 ,仅用作部分肝移植的供体。活体肝脏移植成功率比尸体肝脏移植成功率高 ,存活时间长 ,它不仅可以提供健康的肝脏 ,而且具有遗传和免疫学方面的优点。尸体供肝要求肝热缺血时间不超过 30分钟 ,最好是有心跳的脑死亡尸体。绝大多数致命性脑外伤…     

The challenge of improving donor heart preservation

Heart transplantation has in recent years become the treatment of choice for end stage heart failure. However while the waiting list for transplantation is growing steadily, the donor pool is not increasing. Therefore, in order to meet demand, transplant programs are using older, "marginal donors" and accepting longer ischaemic times for their donor hearts. As donor organs are injured as a consequence of brain death, during the period of donor management, at organ harvest, preservation, implantation and reperfusion, expansion of acceptance criteria places a great burden on achieving optimal long-term outcomes. However, at each step in the process of transplantation strategies can be employed to reduce the injury suffered by the donor organs. In this review, we set out what steps can be taken to improve the quality of donor organs.     

Ischemic preconditioning and nicorandil pretreatment improve donor heart preservation.

The present study investigated the effects of ischemic preconditioning (IPC) and nicorandil pretreatment on myocardial storage in a donor heart preservation model. Isolated rat hearts were separated into groups: group 1, non-preconditioned control group; group 2, 2.5 min of normothermic ischemia followed by 15 min of normothermic Langendorff perfusion (one IPC cycle); and group 3, 2 cycles of IPC. All hearts were subsequently stored in University of Wisconsin solution at 4 degrees C for 2, 4 and 6h, and the concentrations of high-energy phosphate metabolites were measured for each time point. Heart function parameters (aortic flow, coronary flow and cardiac output) were measured when the heart was reperfused following the 2, 4 or 6 h of preservation. The effects of nicorandil, an ATP-sensitive potassium channel opener, on heart function following preservation were also evaluated. Nicorandil was injected intravenously before heart harvesting. The results showed that the energy status was well preserved in the IPC groups. The 2-cycle IPC group showed better recovery of heart function following preservation. Pretreatment with nicorandil also improved functional recovery of the heart following preservation. The present study showed that IPC of the rat heart resulted in improved myocardial energy metabolism and functional recovery after hypothermic preservation, and that nicorandil has potential for pharmacological preconditioning in heart preservation for transplantation.     

Effects of nitric oxide donor S-nitrosoglutathione on apoptosis of apheresis platelets

Objectives: The aim of this study is to investigate the effects of a Nitric oxide (NO) donor, S-nitrosoglutathione (GSNO), on apoptosis and the improvement of preservation quality in apheresis platelets.

Methods: A GSNO solution - to make the final GSNO concentration of 100?uM was added into fresh apheresis platelets, and the parameters associated with platelet morphology, metabolism, and apoptosis were dynamically monitored for seven days.

Results: The results showed that the NO level was remarkably higher during the whole storage stageafter GSNO injection. The number of depolarized platelets and platelets with phosphatidylserine valgus were significantly reduced in the GSNO group compared to that of the control group at some time point. The expression of Bcl-xL mRNA on day 5 of storage in the experimental group was significantly higher than that of the control group, but the expression of Bcl-xL protein was not significantly higher than that in the control group. In addition, Bak and Bax mRNA expression levels in the experimental group were significantly lower than those in the control group, but Bak and Bax protein expression levels were not statistically different. Meanwhile, caspase-3 activity was significantly inhibited.

Discussion and conclusion: These data suggest that the addition of a certain dose of GSNO as a NO donor during platelet storage could inhibit platelet apoptosis and reduce platelet storage lesion (PSL) to a certain extent.     

Coronary angiography utilization in the evaluation of a potential heart donor by age: a narrative review

Heart transplant is the gold standard treatment for patients with heart failure. The limitation to providing heart transplantation to patients suffering from end stage heart disease is the stable organ supply within the United States despite increasing demand. Transplant centers across the United States have begun to expand traditional cardiac donor selection metrics previously utilized. As a result, the use of extended criteria donors, such as older donors, those with longer ischemic times, and donors considered high risk has increased. Current guidelines suggest that coronary angiography be performed when evaluating a donor above the age of 45. Angiographic guidelines for evaluation of the donor heart are based specifically on age, with little evidence based guidance surrounding the use of angiography in a younger donor with comorbidities or increased risk behavior which may lead to premature coronary artery disease. Recently, we have seen an increase in younger heart donors, many of whom have succumbed due to drug overdose with ensuing high risk behaviors. Given the increased risk nature of these donors, consideration of performing coronary angiography is determined by clinical “gestalt” of the transplant center evaluating the heart for use, which may lead to underutilization of donor organs without evidence to support the practice. Here, we review the guidelines, literature, and controversy surrounding the use of coronary angiography in evaluating donor hearts for transplantation.     

阿托伐他汀对冠心病患者血清一氧化氮及一氧化氮合酶含量的影响

目的　观察阿托伐他汀对冠心病患者血清一氧化氮 (NO)及一氧化氮合酶 (NOS)含量水平的影响。方法　对用阿托伐他汀治疗的 79例冠心病患者依据是否合并高胆固醇血症分为两组 ,对其治疗前后血清 NO及 NOS含量水平进行对比分析。结果　不论是否合并高胆固醇血症的冠心病 ,阿托伐他汀均可升高其血清 NO及 NOS水平。结论　阿托伐他汀可通过调脂治疗抑制脂质的过氧化反应 ,保护血管内皮功能 ,但其保护内皮功能的作用不受患者是否存在高脂血症的影响 ,改善内皮功能 ,对冠心病的防治具有重要意义。     

诱导型一氧化氮合酶和解偶联蛋白-2对心肌缺血预适应的作用

目的 探讨诱导型一氧化氮合酶（inducible nitric oxide synthase,iNOS）和解偶联蛋白-2（uncoupling protein-2,UCP2）对大鼠心肌缺血预适应的保护机制。方法 结扎左冠状动脉复制大鼠心肌缺血再灌注模型。预适应组行3次缺血5min,再灌注10min的预处理,分别于预处理0,6,12,24和48h（分别为0,6,12,24和48h亚组）后行30min缺血及120min再灌注：对照组开胸后不结扎左冠状动脉,电镜观察心肌超微结构,据Rainio评分标准进行心肌超微结构损伤程度的半定量分析。采用Western Blot及比色法检测心肌UCP2活性及iNOS活性。结果 预适应各亚组UCP2活性均增高（P〈0．05）,0h亚组UCP2表达水平最高（P〈0．01）,24小时亚组和48小时亚组心肌iNOS活性显著升高（P〈0．05）。结论 UCP2和iNOS共同参与了大鼠心肌缺血预适应心肌保护作用。     

去甲肾上腺素预处理对大鼠供心热休克蛋白70、一氧化氮及一氧化氮合酶表达的影响

目的:探讨去甲肾上腺素预处理是否可诱导心肌热休克蛋白70(HSP70)的合成,并研究其对供心一氧化氮(NO)、一氧化氮合酶(NOS)的影响,探讨去甲肾上腺素预处理心肌保护作用机制。方法:Wistar大鼠18只,分为2组:对照组(C,n=9),腹腔注射0.9%氧化钠注射液0.5 mL,24 h后取离体心脏灌注(Histidine-tryptophan-ketoglutarte,HTK)心脏保护液,4℃保存3 h后建立Langendorff离体心脏灌注模型,灌注(Krebs-Henseleit,K-H)液2 h;实验组(E,n=9)腹腔注射重酒石酸去甲肾上腺素(溶于0.9%氯化钠液中)3.1μmol/kg(0.53 mg/kg),腹腔注射24 h后取离体心脏,处理方法同C组。测定心肌HSP70、NO、NOS的含量以及相关生化指标并做统计学处理比较。结果:HSP70含量E组较C组明显增高(P<0.01),NO、NOS的含量E组较C组明显增多(P<0.01),生化指标E组明显优于C组。结论:去甲肾上腺素预处理能诱导供心心肌组织HSP70、NO、NOS高表达,其对供心具有明显的保护效应,并且其促进心肌NO、NOS的表达,这可能是去甲肾上腺素预处理发挥供心保护作用的机制之一。