Melatonin protects N2a against ischemia/reperfusion injury through autophagy enhancement

Researches have shown that melatonin is neuroprotectant in ischemia/reperfusion-mediated injury.Although melatonin is known as an effective antioxidant,the mechanism of the protection cannot be explained merely by antioxidation.This study was devoted to explore other existing mechanisms by investigating whether melatonin protects ischemia/reperfusion-injured neurons through elevating autophagy,since autophagy has been frequently suggested to play a crucial role in neuron survival.To find it out,an ischemia/...     

缺血性脑卒中病人院前发病过程应对轨迹的质性研究

目的 明确缺血性脑卒中病人和家属院前发病的应对过程,解明其应对规律和影响因素,为构建全面的脑卒中院前干预方案提供科学依据.方法 通过半结构式访谈收集10例个案资料,运用扎根理论研究方法进行资料分析.结果 缺血性脑卒中病人和家属院前发病过程经历了四个阶段,即识别阶段、反应阶段、警觉阶段和行动阶段.结论 健康教育人员应当结合缺血性脑卒中病人和家属院前应对的整个过程,构建全面的、综合性的干预措施.     

PI3K/AKT/Bcl-2通路在吡格列酮保护缺血再灌注损伤心肌细胞中作用的研究

目的 研究吡格列酮对缺血再灌注损伤心肌细胞的保护作用机制中PI3K/AKT/Bcl-2信号通路的作用.方法 取Wistar大鼠乳鼠心室肌细胞进行体外培养,缺氧、复氧各3 h后建立缺血再灌注损伤细胞模型.采用免疫细胞化学染色法检测细胞内Bcl-2蛋白含量,采用Western-bloting检测细胞内Bcl-2蛋白表达水平.结果 免疫细胞化学染色法及Western-bloting结果均显示：与Ⅰ组比较,P组Bcl-2表达明显增加（P〈0.05）;与P组比较,P＋Ly组Bcl-2表达明显减少（P〈0.05）.结论 吡格列酮减轻心肌缺血再灌注损伤保护机制与其激活PI3K/AKT/ Bcl-2信号通路有关.     

Surveillance study for creating the national clinical database relating to ECG-gated myocardial perfusion SPECT of asymptomatic ischemic heart disease in patients with type-2 diabetes mellitus: J-ACCESS 2 study design

Objective Diabetes mellitus is an independent risk factor for acute myocardial infarction. Thus, a surveillance study was conducted as part of studies to create a national database related to electrocardiogram (ECG)-gated myocardial perfusion single-photon emission computed tomography (SPECT) of ischemic heart disease. Methods Single-photon emission computed tomography was conducted in patients with type 2 diabetes mellitus and their prognoses will be followed for 3 years, stratified by patients’ clinical background and SPECT findings. Results A total of 513 patients from 50 institutions were enrolled in this study, 297 of whom were men (age 66.2 ± 0.4 years, mean ± SEM) and 261 women (age 67.8 ± 0.5 years). They have a history of retinopathy (25.3%), neuropathy (19.9%), cerebrovascular disorder, chronic obstructive pulmonary disease, and photocoagulation. Major risk factors for present disease were hypertension (82.3%) and hyperlipidemia (79.7%). In 244 patients (129 men and 115 women), body mass index (BMI) was 25 or more. Fifty-two of them (10.1%) underwent coronary angiography; of these, 26 (50.0%) had no coronary artery lesions with 75% or more stenosis, and only 1 (1.9%) had a left main trunk with 50% or more stenosis. An overwhelming majority of patients (94.3%) underwent SPECT imaging by a 1-day stress-followed-by-rest procedure. Stress procedure was exercise in most (70.8%) patients, followed by dipyridamole infusion in 14.6%, adenosine infusion in 6.6%, and adenosine triphosphate infusion in 5.7%. Endpoint of stress examination was most often fatigue in lower limbs (40.7%), followed by completion of pharmacological stress protocol (28.7%), and achievement of target heart rate (26.3%). The largest number of patients (198, 38.6%) received ^99mTc-tetrofosmin at an initial dosage of 200–300 MBq (mean 331 ± 3 MBq) followed by a second dosage of 700–800 MBq (mean 748 ± 8 MBq). Among them, 491 (95.7%) received some kind of therapeutic drug: hypoglycemic drugs were used by the largest number (83.2%), followed by hypotensive (66.7%), hypolipidemic (40.7%), and antiplatelet drugs (27.7%), vasodilators (5.5%), and antioxidants and others (2.3%). Conclusions This study was designed to clarify the correlation between coronary artery disease and diabetes mellitus as its risk factor based on the clinical and imaging findings. Patient enrollment was closed on September 30, 2005, and follow-up is now under way.     

“预处理”策略对Ⅱ型糖尿病患者围术期心肌保护作用的研究进展

糖尿病是心血管疾患的独立危险因素,糖尿病患者发生急性心肌梗死后的病死率明显升高.缺血预处理（IPC）、缺血后处理（IPOST）、远端肢体/组织预处理（RIC）以及麻醉药物预处理（APC）等“预处理”策略,已被证明在非糖尿病患者能够发挥明显的心肌保护作用,近年有研究认为,在Ⅱ型糖尿病患者其心肌保护作用被减弱或者消失.现就“预处理”技术对Ⅱ型糖尿病患者缺血性心肌损害的保护作用及其机制的研究进展予以综述.     

天香丹对大鼠心肌缺血再灌注损伤的保护作用研究

目的:探讨天香丹冲剂预处理对大鼠急性心肌缺血再灌注损伤的保护作用。方法:Wistar大鼠40只,随机分为正常对照组(不做任何处理)、实验对照组(生理盐水灌胃)以及天香丹低、高剂量组(天香丹分别为0.38g/250g体重、1.5g/250g体重,灌胃10d),实验对照组和天香丹低、高剂量组手术致心肌缺血,检测复灌后各组心电图ST段的变化、左室内压上升和下降最大速率(±dp/dtmax),复灌结束后颈动脉取血并切取心脏,心脏切片后0.1%TTC染色,检测心肌梗死范围及各组血清中谷胱甘肽过氧化物酶(GSH-Px)的活性和丙二醛(MDA)含量。结果:与实验对照组相比,天香丹高剂量组心肌梗死面积减小较为显著,ST段回落明显(P<0.05~0.01),±dp/dtmax明显升高,GSH-Px的活性明显增强,MDA含量降低(P<0.01);天香丹低剂量组GSH-Px活性和MDA含量没有明显变化。结论:天香丹冲剂预处理对大鼠心肌缺血再灌注损伤有一定的保护作用。     

丹参对高原大鼠肝缺血再灌注损伤的保护作用

目的:探讨丹参(SM)对大鼠缺血再灌注(IR)肝细胞凋亡和凋亡抑制基因bcl-2表达的影响。方法:用TUNEL法观察IR后的肝细胞凋亡,并用免疫组织化学法检测相关基因表达变化;以丹参注射液干预IR的大鼠模型,观察了丹参对IR后肝细胞凋亡的作用,并与平原对照比较。结果:IR后肝细胞有典型的凋亡特征,与丹参组比较肝细胞的凋亡率有明显差异(P<0.01)。IR组bcl-2表达下调,而丹参组的表达量明显增加(P<0.01)。上述基因表达变化与病理改变一致,但与平原比较,高原较平原重。结论:丹参能减少大鼠IR肝细胞凋亡,并能上调IR肝细胞凋亡抑制基因的蛋白表达。后者可能是丹参抑制IR肝细胞凋亡的机制之一。     

益气活血法对缺血再灌注损伤血瘀证兔心肌细胞间黏附分子-1表达的影响

目的研究益气活血法对心肌缺血再灌注损伤(IRI)血瘀证兔心肌细胞间黏附分子-1(ICAM-1)蛋白表达影响,以探讨其对心肌IRI保护作用机制。方法建立血瘀证兔IRI模型,以加味丹参饮对该模型进行干预,采用放免法检测各组炎症因子(TNFa和IL-2)水平变化,免疫组化法观察心肌ICAM-1蛋白表达。结果IRI组TNFa、IL-2水平明显升高,ICAM-1蛋白表达显著增高,与空白组比较差异具有统计学意义(P<0.01);加味丹参饮组可以对抗TNFaI、L-2水平升高,降低ICAM-1蛋白表达,与IRI组比较差异具有统计学意义(P<0.05或P<0.01)。结论益气活血法可以降低IRI心肌ICAM-1蛋白表达,对抗炎症因子水平,这可能是其保护心肌IRI作用机制之一。     

补阳还五汤对全脑缺血再灌注不同时点大鼠皮质神经细胞谷氨酸受体2表达的影响

目的 研究补阳还五汤抗全脑缺血后再灌注损伤的分子机制.方法 将SD大鼠随机分为3组,即正常组、模型组和药物组(补阳还五汤预干预),模型组和药物组再分别设置2、12、24、48、72 h五个观察时间点.连续给药5 d后,采用改良的Pulsinelli四血管闭塞法复制全脑缺血大鼠模型,再灌注后2、12、24、48、72 h分别检测各组大鼠皮质神经细胞谷氨酸受体2(glutamate receptor 2,GluR2)的表达水平.结果 与正常组比较,再灌注各时点模型组大鼠大脑皮质神经细胞GluR2表达水平显著降低(P<0.01);与模型组比较,再灌注各时点药物组GluR2表达水平显著升高(P<0.01);与再灌注2 h比较,再灌注12、24、48、72 h药物组GluR2表达水平显著升高(P<0.01).结论 补阳还五汤可预防大鼠脑缺血再灌注引起的GluR2表达减少,且在再灌注2 h后这种抑制作用更强.