麦牙醇对大鼠不完全脑缺血再灌注损伤的实验研究

目的　研究麦芽醇 (Maltol,MT)对大鼠海马组织不完全性脑缺血再灌注损伤的保护作用。方法　Wistar大鼠双侧颈总动脉夹闭 30min,造成不完全脑缺血 ,松开动脉夹即为再灌注。 2 4只大鼠随机分为三组 :(1 )假手术对照组 (SOC) ,相同手术操作 ,但不夹闭动脉 ;(2 )缺血再灌注组 (IR) ,再灌注 1h ;(3)麦芽醇治疗组 (MT) ,夹闭动脉前后静脉注射 70 0 μmol·L- 1 麦芽醇生理盐水。 3组动物均于再灌注后测海马组织中的丙二醛 (MDA)值、超氧化物歧化酶 (SOD)和ATP酶活性。结果　缺血再灌注组MDA明显升高 (P <0 0 1 ) ,SOD、ATP酶活性明显降低 (P <0 0 1 ) ,MT能降低升高的MDA值 ,改善ATP酶活性 (P <0 0 1 )。但不能改善SOD活性。结论　麦芽醇能清除氧自由基 ,减少脂质过氧反应 ,改善ATP酶活性 ,从而减轻海马组织缺血再灌注损伤。     

基于脑小血管病临床脑血流特点构建并评估不完全性全脑缺血再灌注大鼠模型

目的:基于脑小血管病(CSVD)的脑血流特点构建和评估不完全性全脑缺血再灌注大鼠模型,以期为CSVD等缺血性脑血管疾病的基础研究提供理想的大鼠实验模型。方法:将126只雄性SD大鼠随机分为假手术(sham)组、轻损伤模型组(minor组)和重损伤模型组(serious组),每组42只。采用双侧颈总动脉夹闭-开放循环操作的方法,构建大鼠不完全性全脑缺血再灌注模型,激光散斑血流成像系统评估脑血流实时变化;于造模后2、24和72 h,评估造模动物存活率和动物行为学(平衡木实验,BBT)评分;于造模2、24和72 h取材,采用HE染色观察大鼠不同脑区组织病理形态改变;并运用非靶向代谢组学分析模型大鼠血浆和脑皮质区差异代谢物,评估模型损伤程度。结果:(1)与sham组比较,minor组和serious组大鼠总存活率平均值分别为83.2%和73.7%(P<0.05);(2)残存脑血流量平均值分别为56.3%和40.9%;(3)神经功能检查显示,与sham组比较,minor组和serious组造模后2、24和72 h的BBT评分均显著升高(P<0.05);(4)HE染色镜下可见广泛脑皮质...     

葛根素对脑缺血再灌注损伤保护机制的研究现状

葛根素(Puerarin)是临床上常用的中药注射剂,作为改善心脑血管循环的药物,广泛运用于治疗心肌梗塞和中风性疾病。近年来,对其在脑缺血再灌注损伤中所起的保护作用研究较多,本文主要就葛根素的脑保护机制作一综述。     

葛根素对大鼠局灶性脑缺血再灌注损伤后炎症反应的抑制作用

目的： 观察葛根素对大鼠局灶性脑缺血再灌注损伤后炎症反应的抑制作用并探讨其作用机制。方法: 采用大鼠大脑中动脉内栓线阻断法（MCAO）复制大鼠脑缺血再灌注损伤模型，于缺血开始及再灌注即刻由尾静脉注射葛根素18 mg·kg-1，缺血 2 h 再灌注 24 h 后取缺血侧脑组织，HE染色观察海马存活锥体细胞数，比色法测定脑组织MPO活性观察脑组织中性粒细胞浸润程度，Western blotting及RT-PCR法测定脑组织中ICAM-1 蛋白及mRNA表达情况及NF-κB p65亚基核转位情况。结果: 葛根素组缺血侧脑组织海马存活锥体细胞数明显高于缺血再灌注损伤组（P<0.01）， MPO活性明显低于缺血再灌注损伤组（P<0.01），ICAM-1 蛋白及mRNA表达较缺血再灌注损伤组明显减少（P<0.01），NF-κB p65蛋白亚基核转位明显少于缺血再灌注损伤组（P<0.01）。结论: 葛根素可减轻大鼠脑缺血再灌注损伤后炎症反应，这可能是其发挥脑保护作用的机制之一。     

双侧颈总动脉夹闭法构建脑缺血再灌注损伤模型的经验总结

双侧颈总动脉夹闭法因其操作简单、动物死亡率低、模型成功率高等优点正在受到广泛的应用,本文通过对原有的双侧颈总动脉夹闭法构建脑缺血再灌注损伤模型进行了一定的优化,并总结了一些成功的经验和体会,以期能为模型制作提供一定的参考。     

氯碘羟喹对脑缺血沙土鼠海马神经元的保护作用

目的研究金属螯合剂氯碘羟喹(Clioquinol,CQ)对沙土鼠全脑缺血再灌注后海马CA3区锥体细胞的保护作用。方法无创动脉夹夹持沙土鼠双侧颈总动脉制备脑缺血模型,腹腔注射CQ 3d,应用金属自显影技术检测CQ对沙土鼠海马游离锌离子的螯合作用,TUNEL和caspase-3原位杂交分析CQ对脑缺血沙土鼠海马神经元凋亡的影响。结果脑缺血CQ处理组沙土鼠海马金属自显影阳性反应明显低于脑缺血溶剂对照组,脑缺血CQ处理组沙土鼠海马TUNEL和caspase-3阳性细胞数量明显低于脑缺血溶剂对照组。结论 CQ对沙土鼠海马游离锌离子有明显的螯合作用,可能与其对脑缺血再灌注损伤的保护作用有关。     

大鼠脑缺血-再灌注损伤对脑微血管通透性的影响

目的 :探讨大鼠脑缺血 -再灌注后脑组织微血管通透性的变化规律 ,为进一步探讨脑缺血及再灌注损伤机制提供参考数据。方法 :应用荧光素钠 (分子量 3 86 ,Fl Na)和 FITC标记的右旋糖苷( FD4,分子量 40 0 0 )为荧光示踪剂 ,以单侧颈总动脉远心端及同侧颈静脉插管并连接二管造成颈总动脉向颈静脉的引流 ,同时用动脉夹夹闭对侧颈总动脉造成脑缺血模型。缺血 1h后松开动脉夹并中断引流造成再灌注模型。测量脑组织荧光强度反映脑微血管通透性的变化。结果 :单纯的脑缺血即可引起脑组织微血管通透性的增强 ,再灌注后对小分子量物质的通透性随再灌注时间的延长有增加的趋势 ,而对较大分子量物质的通透性基本维持在同一水平。结论 :即使是在再灌注损伤最严重时 ,脑微血管对较大分子量的物质通透仍不明显 ,说明血 -脑屏障的存在可以有效地防止有害物质通过微血管壁侵入脑组织 ,但一旦进入脑组织 ,将滞留于脑组织中不易清除。     

葛根素对大鼠后肢缺血再灌注损伤骨骼肌和周围神经的保护作用

目的 研究葛根素在大鼠后肢缺血再灌注损伤中对骨骼肌及周围神经的保护作用.方法 30只健康雌性SD大鼠按随机原则分为手术+葛根素组(P组)及手术 + 生理盐水组(N组)、假手术+生理盐水组(S组),术前1 h开始分别行腹腔注射药物.手术采用橡皮筋套圈阻断大鼠左后肢髂总动、静脉4 h再恢复血运,建立肢体缺血再灌注损伤的动物...     

脑缺血再灌注后小鼠海马神经前体细胞的增殖

目的:研究小鼠脑缺血再灌注后海马神经前体细胞的增殖。方法:采用无创微动脉夹夹闭小鼠双侧颈总动脉0·5h的方法制作脑缺血再灌注动物模型。分正常对照组、假手术组、实验组小鼠脑缺血再灌注后1、3、5、7、14、21、28d组,共7个时相点。各组小鼠于各时相点处死前注射5-溴脱氧尿苷嘧啶(BrdU)。处死后取出脑组织制备石蜡切片进行Nissl染色,BrdU免疫组织化学显色,观察脑组织缺血后的病理变化并比较缺血后不同时相点神经前体细胞增殖的差异。同时从小鼠心采血进行血气分析。结果:夹闭小鼠双侧颈总动脉的脑缺血再灌注模型可致PO2明显降低,PCO2明显升高,大脑皮质出现了缺血的形态学变化。小鼠海马BrdU 细胞在脑缺血再灌注后1d开始增加,7d达到高峰,28d恢复正常水平。结论:夹闭双侧颈总动脉是致小鼠脑缺血再灌注损伤的理想模型。小鼠脑缺血再灌注损伤能激活海马神经前体细胞的增殖,并在术后7d达峰值。     

尼古丁对大鼠局灶性脑缺血再灌注损伤的神经保护作用

目的:研究尼古丁对大鼠局灶性脑缺血再灌注损伤是否具有神经保护作用。方法:在大鼠大脑中动脉堵塞(MCAO)前30min给予腹腔注射尼古丁酒石酸盐溶液,观察局灶性脑缺血2h再灌注24h后,大鼠神经行为学评分及脑梗死容积的变化。结果:再灌注24h后,与单纯缺血再灌注组相比,给予尼古丁酒石酸盐溶液注射可以改善动物的神经行为学评分、减少脑梗死容积百分比(P0.05)。结论:尼古丁对大鼠局灶性脑缺血再灌注损伤具有神经保护作用。     

雷公藤甲素抗肿瘤血管新生的研究进展（英文）

雷公藤甲素(triptolide,TPL)是从中草药雷公藤中提取的一种有效活性物质,已被用来治疗多种疾病,包括系统性红斑狼疮,类风湿性关节炎,肾病综合征等,TPL甚至有很强的抑制肿瘤的活性。近些年的研究显示,TPL具有抗血管新生的能力,TPL不仅可以抑制肿瘤的增殖,诱导细胞的凋亡,还可以抑制肿瘤的转移,可以增加其它化疗药物的抗肿瘤活性。本综述将讨论TPL在抗肿瘤血管新生方面的研究进展,以及初步探讨其潜在的作用机制。     

Restoration of in vitro responses in platelets stored in plasma

Conventional platelet storage in a blood bank is up to 5 days at room temperature in plasma. We investigated the optimal medium for assessing the quality of stored platelets by comparing in vitro test responses after resuspension in autologous plasma prepared from platelet-rich plasma after 5 days of storage at room temperature, autologous plasma stored cell-free for 5 days at room temperature, or autologous plasma stored cell-free for 5 days at -20 degrees C. Five-day-old platelets were prepared from aliquots of the same unit and resuspended in I of the 3 plasma preparations. The platelet-plasma mixtures were monitored for changes in pH, mean platelet volume, hypotonic shock response, P-selection expression, and aggregation. There were statistically significant differences between platelets resuspended in original plasma and platelets resuspended in either plasma stored cell-free at room temperature or frozen, with regard to hypotonic shock response, agonist-induced aggregation, and P-selectin expression. Plasma stored with platelets for 5 days yielded inferior platelet function test responses when compared with plasma stored cell-free at room temperature or frozen. Therefore, for direct comparison of platelet responses following novel storage methods, the resuspending plasma should be stored under the same conditions as the control platelet unit.     

Changes in activity of neutral proteases in tissues of ground squirrels in the dynamics of hibernation

Total activities of neutral proteases in the cerebral, hepatic, and myocardial tissues of ground squirrel vary during hibernation: in autumn (before hibernation) activities of the enzymes in the brain and myocardium start increasing, while in the liver they do not change. A common feature for all tissues is minimum activity of active neutral proteases in the middle of hibernation month 1 bout, while the maximum activity is recorded before awakening. Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 146, No. 9, pp. 278–280, September, 2008     

Kinetics of decline of maternal measles virus-neutralizing antibodies in sera of infants in France in 2006

The optimal age for measles vaccination is an important health issue, since maternal antibodies may neutralize the vaccine antigen before a specific immune response develops, while delaying vaccination may increase the risk of complicated diseases in infants. However, measles vaccination impacts the duration of protection afforded by transplacental transfer of maternal antibodies: vaccination-induced maternal antibodies disappear faster than disease-induced antibodies. In order to maintain protection against measles in infants, it is important to monitor the dynamics of this phenomenon in vaccinated populations. To assess the current situation in France, a multicenter, prospective seroepidemiological study was conducted in seven French hospitals between October 2005 and January 2007. Maternal measles antibody concentrations from 348 infants 0 to 15 months old were measured using the plaque reduction neutralization assay. Geometric mean concentrations and the percentage of infants with maternal measles antibody concentrations above the protection threshold (≥120 mIU/ml) were assessed according to age. Results show that after more than 20 years of routine measles vaccination in France, maternal measles-neutralizing antibodies decrease dramatically in French infants by 6 months of age, from 1,740 mIU/ml for infants 0 to 1 month old to 223 mIU/ml for infants 5 to 6 months old, and that 90% of infants are not protected against measles after 6 months of age. Infant protection against measles could be optimized both by increasing herd immunity through an increased vaccine coverage and by lowering the age of routine vaccination from 12 to 9 months.