电针预处理通过上调Peroxiredoxin 6减轻大鼠脑缺血再灌注损伤

目的:探讨Peroxiredoxin 6(Prx 6)在电针预处理诱导的SD大鼠脑缺血耐受中的作用。方法:健康雄性SD大鼠80只,随机分为4组:假手术组(Sham组,n=16)、单纯电针组(Electro acupuncture组,EA组,n=16)、局灶性脑缺血再灌注组[通过大脑中动脉栓塞制作脑缺血再灌注(middle cerebral artery occlusion,MCAO)模型,MCAO组,n=32],其中2、6、12、24、48 h各4只和电针预处理组(EA+MCAO组,n=16)。通过梗死容积及神经功能评分(Garcia评分)评价脑损伤程度;通过Western Blot检测Prx 6在脑缺血再灌注后的表达水平;通过Western Blot和免疫组织化学染色法检测电针预处理对Prx 6表达的影响。结果:与MCAO组相比,EA+MCAO组梗死容积减少,神经功能评分显著改善(P0.05);与Sham组相比,Prx 6在MCAO模型后再灌注24 h时表达最高(P0.05);与Sham组相比,再灌注后24 h时MCAO组Prx 6表达水平升高(P0.05);与MCAO组相比,再灌注后24 h时EA+MCAO组Prx 6的表达水平进一步升高(P0.05)。结论:电针预处理通过促进缺血再灌注后Prx 6的表达升高而发挥脑保护作用。     

电针预处理大鼠百会穴对脑缺血保护作用及HIF-1α相关机制的研究

目的:旨在证实电针预处理百会穴对脑缺血损伤的保护作用及HIF-1α的相关机制。方法:将雄性SD大鼠80只随机分为5组(n=16):假手术组(Sham),对照组(CON),电针预处理组(EA),HIF-1α抑制剂组(2ME2)和电针预处理+HIF-1α抑制剂组(EA+2ME2)。CON组、2ME2组、EA组及EA+2ME2组动物均建立大脑中动脉阻闭模型(MCAO),Sham组动物仅接受同前手术操作;EA组及EA+2ME2组大鼠接受连续5 d电针刺激后24 h建立MCAO模型;2ME2组及EA+2ME2组动物分别于MCAO模型制备前30 min腹腔注射16 mg/kg的2ME2。缺血再灌注后24 h,各组随机抽取8只动物处死,行TUNEL染色检测神经元凋亡,Western Blot检测缺血半暗带中Bcl2/Bax的表达;缺血再灌注后72 h,各组另8只动物接受神经功能学评分后行磁共振成像(MRI)检查,随后处死行TTC染色检测脑梗死容积。结果:EA组脑梗死容积百分比显著低于CON组(P0.05);与CON组比较,EA组神经功能评分显著改善(P0.05),而2ME2可以显著降低EA+2ME2组神经功能评分(P0.05)。与CON组比较,EA组神经功能评分显著改善(P0.05),而2ME2可以显著降低EA+2ME2组神经功能评分(P0.05)。而CON组及EA+2ME2组中TUNEL阳性细胞显著多于EA组(P0.05)。与EA组比较,CON组及EA+2ME2组中Bcl-2蛋白表达显著降低(P0.05),而CON组中Bax蛋白表达显著增加(P0.05)。结论:电针预处理百会穴对脑缺血再灌注损伤具有明显的保护作用,其机制可能是HIF-1α抑制缺血后神经凋亡、上调凋亡抑制蛋白Bcl-2表达、下调促凋亡蛋白Bax表达,达到脑缺血保护的作用。     

电针预处理对MCAO大鼠模型血脑屏障和MMP-9的影响

目的:探讨电针(EA)预处理对大鼠脑缺血再灌注后血脑屏障(BBB)通透性及脑内基质金属蛋白酶-9(MMP-9)表达的影响。方法:96只成年雄性SD大鼠随机分为假手术(Sham)组、单纯电针(EA)组、缺血(MCAO)组及电针预处理(EA+MCAO)组,每组24只。使用线栓法制作大鼠大脑中动脉阻塞(MCAO)模型,缺血120 min再灌注48 h后处死取脑。分别采用干湿重法测定各组动物脑水含量,伊文斯蓝(EB)法检测血脑屏障通透性,Western Blot检测紧密连接蛋白(TJP)及MMP-9表达水平,同时明胶酶谱法检测MMP-9活性。结果:与Sham组相比,MCAO组大鼠脑水含量及EB含量增多(P0.05),缺血侧脑组织TJP水平下降(P0.05),MMP-9表达及活性明显升高(P0.05);与MCAO组大鼠比较,EA+MCAO组脑水含量及EB含量减少(P0.05),缺血侧脑组织TJP水平升高(P0.05),同时MMP-9表达及活性显著降低(P0.05)。结论:电针预处理通过抑制缺血后脑内MMP-9的表达及活性,维持BBB完整性,有效改善脑缺血后的脑水肿症状。     

大鼠脑缺血再灌注损伤后极化的小胶质细胞排斥性导向分子A的表达变化

目的 探讨大鼠大脑中动脉缺血再灌注损伤后极化的小胶质细胞排斥性导向分子A（RGMa）的表达变化。 方法 取雄性SD大鼠30只,随机分成对照组,缺血再灌注损伤7 d、14 d模型组（I/R）,采用线栓法制作大鼠大脑中动脉缺血再灌注损伤模型(tMCAO);Real-time PCR检测M1、M2型小胶质细胞标记分子白细胞介素-1β（IL-1β）、诱导性一氧化氮合酶（iNOS）、精氨酸酶1（Arg-1）及CD206 mRNA的表达;免疫荧光检测缺血区小胶质细胞RGMa的表达;体外培养小胶质细胞,分别用M1或M2型小胶质细胞的诱导物脂多糖（LPS）或IL-4诱导24 h后,利用Real-time PCR检测M1、M2型小胶质细胞标记分子IL-1β、iNOS、Arg-1、CD206 mRNA的表达;Western blotting检测M1、M2型小胶质细胞上RGMa的表达。 结果 缺血再灌注损伤后7 d、14 d,M1、M2型小胶质细胞的标记分子表达增加。缺血后7 d、14 d激活的小胶质细胞上RGMa大量表达。RGMa在体外培养的LPS诱导极化的M1型小胶质细胞和IL-4诱导极化的M2型小胶质细胞上表达均显著增加。 结论 大鼠大脑中动脉缺血再灌注损伤后,RGMa在缺血区M1型和M2型极化的小胶质细胞上均大量表达,RGMa可能在小胶质细胞激活极化过程中发挥重要作用。RGMa可能是缺血性脑卒中治疗的新靶点。     

TREM2通过激活Th17细胞调节神经免疫炎症并保护局灶性脑缺血再灌注损伤北大核心CSCD

目的:探讨髓细胞触发受体2(TREM2)调节局灶性脑缺血再灌注损伤和神经免疫炎症的作用和机制。方法:对小鼠的大脑行中动脉闭塞术(MCAO)以建立局灶性缺血再灌注损伤模型,分为假手术组(sham组)和MCAO组(n=6)。小干扰RNA(siRNA)构建TREM2的沉默质粒(TREM2 siRNA组),构建TREM2过表达质粒(pcDNA-TREM2组),以及各自的阴性对照(CON siRNA)组和pcDNA组分别感染MCAO小鼠。采用IL-17抑制剂苏金单抗(SEC)联合pcDNA-TREM2处理MCAO组(MCAO+pcDNA-TREM2+SEC组)。qPCR和Western blot检测TNF-α、IL-1β、IL-17和TREM2表达;免疫荧光法检测脑部TREM2定位;TTC染色评价脑损伤程度;流式细胞术检测Th17细胞比例。结果:TREM2表达于小胶质细胞,且MCAO组TREM2表达均增加(P<0.05)。沉默TREM2诱导神经元细胞凋亡(F=206.971,P=0.001)、梗死体积和神经功能障碍评分升高(均P<0.05),TNF-α和IL-1β的mRNA水平升高,IL-10降低(均P<0.05)。过表达TREM2导致TNF-α、IL-1β表达降低,而IL-10和IL-17表达及Th17阳性细胞比例升高(均P<0.05)。与MCAO+pcDNA-TREM2组比较,MCAO+pcDNA-TREM2+SEC组的Th17细胞比例降低、神经元百分比降低,脑损伤程度增加,TNF-α、IL-1β表达升高,IL-10和IL-17表达降低(均P<0.05)。结论:过表达TREM2可通过激活Th17细胞并抑制神经炎症从而保护局灶性脑缺血再灌注损伤。     

白细胞介素-11在小鼠脑缺血再灌注损伤中的保护作用及其机制

目的探讨白细胞介素-11(interleukin-11,IL-11)在小鼠脑缺血再灌注损伤中的保护作用及机制研究。方法选择SPF级C57BL/6雄性小鼠60只,随机分成为对照组、模型组和IL-11组,每组各20只,通过线栓法构建脑缺血再灌注损伤。应用TTC染色检测脑组织梗死面积,采用Longa评分法评估各组小鼠的神经功能,检测并计算各组小鼠的脑组织含水量。应用Western blot法检测脑组织诱导型一氧化氮合酶(iNOS)、IL-1β、CD206和精氨酸酶(Arginase)-1蛋白表达水平。应用酶联免疫吸附(ELISA)法检测IL-1、IL-6、IL-10和肿瘤坏死因子(TNF)-α水平。免疫荧光双染检测IL-11对小胶质细胞分化的影响。结果与对照组比较,模型组小鼠脑组织梗死面积、含水量和Longa评分均显著升高(均P<0.05);与模型组比较,IL-11组小鼠脑组织梗死面积、含水量和Longa评分均显著减低(均P<0.05);与对照组比较,模型组小鼠M1型小胶质细胞数量明显升高(均P<0.05);与模型组比较,IL-11组小鼠M1型小胶质细胞数量降低,M2型小胶质细胞数量升高(均P<0.05);与对照组比较,模型组小鼠M1型小胶质细胞标记物iNOS和IL-1β表达升高(均P<0.05);与模型组比较,IL-11组小鼠M1型小胶质细胞标记物iNOS和IL-1β表达降低,M2型小胶质细胞标记物CD206和Arginase-1表达升高(均P<0.05);与对照组比较,模型组小鼠脑组织IL1、IL-6、TNF-α水平明显升高,IL-10水平明显降低(均P<0.05);与模型组比较,IL-11组小鼠脑组织IL-1、IL-6和TNF-α水平明显降低,IL-10水平明显升高(P<0.05)。结论IL-11促进小胶质细胞由促炎表型M1型向抗炎表型M2型转化,降低脑组织炎症,发挥脑缺血保护作用。     

小胶质细胞在大鼠暂时性局灶脑缺血再灌注后脑损伤区活化反应的初步研究

目的:探讨暂时性局灶脑缺血后小胶质细胞的反应规律,进一步探讨小胶质细胞在脑缺血损伤中的作用。方法:采用线栓法建立大鼠大脑中动脉阻塞(middle cerebral artery occlusion,MCAO)再灌注模型,应用组织学、免疫组化染色及免疫荧光双标技术,观察大脑中动脉阻塞30 min,再灌注0.5、3、6 h以及1、3、7、14 d和28 d后脑组织的损伤情况,小胶质细胞的形态学和数量变化。结果:组织学观察结果显示:MACO30 min再灌注0.5 h后,梗死区出现神经元肿胀,脑水肿;再灌注3 h和6 h,脑水肿加重,部分神经元出现核固缩,对侧脑组织也出现水肿。脑水肿和神经元固缩在再灌注1 d时最重。再灌注3 d开始,脑水肿程度逐渐减弱,缺血区浸润的小胶质细胞增多。再灌注7 d时,缺血灶小胶质细胞浸润最明显,伴胶质结节形成,再灌注14 d,胶质瘢痕逐渐减小。再灌注28 d,大多数动物梗死区仅存少量小胶质细胞,个别未能修复的坏死灶液化并形成囊腔。免疫组化和免疫荧光双标记结果显示:假手术组小胶质细胞的胞体小,突起细长柔和。脑缺血30 min再灌注0.5 h可见小胶质细胞的体积增大,突起少而短。缺血再灌注6 h,小胶质细胞的胞体增大,突起减少或消失。再灌注1 d和3 d,小胶质细胞的数量明显多于假手术组(P0.05)。再灌注7 d,细胞数量增加达到高峰。再灌注14 d以后,小胶质细胞的数量进一步减少,再灌注28 d后小胶质细胞的数量少于再灌注7 d,但仍多于假手术组和缺血再灌注3 d(P0.05)。结论:暂时性局灶脑缺血能够引起小胶质细胞活化和增生,经历损伤性、反应性、效应性和恢复性变化四个阶段。小胶质细胞在脑缺血损伤组织的清除和损伤修复等方面发挥重要作用。     

大蒜素抑制小胶质细胞活化在脑缺血再灌注模型中发挥抗炎效应的研究

目的在大鼠脑缺血再灌注模型中研究大蒜素抑制中枢神经系统参与免疫调节的小胶质细胞活化以及小胶质细胞释放炎症因子的效应。方法采用大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)的神经炎症模型缺血30 min后再灌注,用Western blot技术检测缺血皮质区在第1天和第3天小胶质细胞活化情况和白介素1-β(IL-1β)的表达水平变化,缺血再灌注模型脑室注射大蒜素后用Western blot和实时荧光定量PCR技术检测小胶质细胞标记物IBA-1和IL-1β的蛋白及mRNA表达水平的变化。离体实验中,用大蒜素预处理BV2细胞后再进行氧糖剥夺处理(oxygen glucose deprivation,OGD),观察IL-1β的蛋白和mRNA水平的变化。结果大鼠缺血再灌注模型中,缺血皮质区的小胶质细胞活化水平在第1、3天显著升高,IL-1β表达水平显著上升(P0.05);大蒜素处理后,缺血皮质区的小胶质细胞的活化水平显著下降(P0.05),IL-1β的蛋白表达以及mRNA水平显著下调(P0.05)。对BV2细胞用大蒜素预处理再进行OGD处理后,IL-1β的蛋白表达和mRNA水平显著下降(P0.05)。结论在脑缺血再灌注模型中,大蒜素可能通过抑制小胶质细胞活化以及抑制小胶质细胞释放IL-1β等细胞因子发挥抗炎作用。     

依达拉奉对脑缺血大鼠大脑皮质Notch-1表达的影响

目的:探讨依达拉奉对脑缺血大鼠大脑皮质Notch-1表达的影响。方法:应用微创开颅法复制大鼠大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)模型。将SD大鼠随机分为假手术组(Sham组)、模型组(MCAO组)和依达拉奉组(E组)。应用TTC染色测定大鼠MCAO后梗死体积,免疫组化单标、荧光双标、Realtime PCR和Western Blot技术检测大鼠MCAO后不同时间点大脑皮质Notch-1的表达变化。结果:(1)TTC染色显示依达拉奉治疗组大鼠脑缺血梗死区域明显缩小,梗死体积与MCAO组比较有显著差异(P0.05);(2)免疫组化单标染色显示Sham组大鼠大脑皮层未见Notch-1阳性细胞表达,MCAO组于1 d、3 d及7 d在缺血半暗区可见大量Notch-1阳性细胞,依达拉奉可减少大鼠大脑皮层Notch-1阳性细胞数(P0.05);(3)荧光双标染色显示缺血半暗区见大量呈激活状态的小胶质细胞和Notch-1阳性细胞,小胶质细胞有Notch-1表达,依达拉奉可降低Notch-1在小胶质细胞中的表达;(4)RT-PCR和Western Blot结果显示依达拉奉可明显降低MCAO大鼠Notch-1的mRNA和蛋白表达(P0.05)。结论:大鼠脑缺血后小胶质细胞大量激活并表达Notch-1信号;依达拉奉可能通过Notch-1信号通路抑制小胶质细胞的激活,对缺血后脑组织发挥保护作用。     

川芎嗪对大鼠脑缺血再灌注损伤后GFAP表达和脑组织水肿的影响

探讨川芎嗪对大鼠脑缺血再灌注损伤后星形胶质细胞表达胶质原纤维酸性蛋白(GFAP)以及对脑组织含水量的影响。将70只SD大鼠随机分为3组:脑缺血后1、3、5、7、10d模型组(n=30,每个时间点用6只)、川芎嗪预处理组(n=30,每个时间点用6只)和假手术组(n=10,每个时间点用2只)。采用线栓法制作大鼠局灶性脑缺血再灌注模型(MCAO),应用免疫组化法观察星形胶质细胞GFAP的表达,干湿重法测定脑组织的含水量。结果显示:川芎嗪预处理组大鼠各时间点海马CA1区的GFAP阳性细胞数量显著增多,与缺血模型组比较均有显著性差异(P<0.05)。缺血再灌注后脑组织含水量持续性增加,到3d达到最高峰,5d时仍较高,以后逐渐降低;川芎嗪组各时间点的脑组织含水量均低于缺血模型组(P<0.05)。上述研究结果提示川芎嗪可引起星形胶质细胞活化、保护神经元、减轻脑水肿,具有防治脑缺血再灌注损伤的作用。     

Development in in vitro toxicology

There are three principal pressures driving the development of in vitro toxicology: (1) the need for more efficient testing systems to cope with the large number of xenobiotics currently being developed; (2) public pressure to reduce animal experimentation; and (3) a need for a better understanding of the mechanisms of toxicity. Within this, in vitro toxicology is focused on local, systemic, and target-organ toxicity. It is becoming increasingly apparent that a step or decision-tree approach using input of a variety of experimental data (physicochemical properties, biokinetics, cytotoxicity) provides the most efficient system for predicting toxicity. Examples of the use of in vitro toxicity systems for prediction of systemic toxicity and target-organ (liver) toxicity are presented.Originally presented at ECCP 93.     

Seasonal variations in acute toxoplasmosis in pregnant women in Slovenia

Between December 1999 and December 2004, 40 081 pregnant women were examined for toxoplasmosis with Toxo-IgG, Toxo-IgM enzyme immunoassay. Women with positive results were then retested with the Toxo-IgG avidity assay for recent toxoplasmosis. Recent acute toxoplasmosis in pregnant women was found to be significantly more frequent (p < 0.01) during winter than summer. The incidence of acute toxoplasmosis during winter-spring was also significantly more frequent (p < 0.025) than summer-autumn. This phenomenon should be taken into account when formulating preventive measures for toxoplasmosis, especially for pregnant women.     

Age-related changes in polyamines in memory-associated brain structures in rats

Polyamines putrescine, spermidine and spermine are positively charged aliphatic amines and have important roles in maintaining normal cellular function, regulating neurotransmitter receptors and modulating learning and memory. Recent evidence suggests a role of putrescine in hippocampal neurogenesis, that is significantly impaired during aging. The present study measured the polyamine levels in memory-related brain structures in 24- (aged), 12- (middle-aged) and 4- (young) month-old rats using liquid chromatography/mass spectrometry and high performance liquid chromatography. In the hippocampus, the putrescine levels were significantly decreased in the CA1 and dentate gyrus, and increased in the CA2/3 with age. Significant age-related increases in the spermidine levels were found in the CA1 and CA2/3. There was no difference between groups in spermine in any sub-regions examined. In the parahippocampal region, increased putrescine level with age was observed in the entorhinal cortex, and age did not alter the spermidine levels. The spermine level was significantly decreased in the perirhinal cortex and increased in the postrhinal cortex with age. In the prefrontal cortex, there was age-related decrease in putrescine, and the spermidine and spermine levels were significantly increased with age. This study, for the first time, demonstrates age-related region-specific changes in polyamines in memory-associated structures, suggesting that polyamine system dysfunction may potentially contribute to aged-related impairments in hippocampal neurogenesis and learning and memory.     

休克过程中肾上腺髓质素变化的研究进展

Adrenomedullin (AM) is a new peptidergic regulator of vascular function. AM serves as a hormone, which has many biological properties, plays an important role in the many pathophysiological processes, especially shock. This review will highlight the structure, biological properties of AM and the relationship between AM and shock.     

Secular change in menarche in women in Madrid

The age at menarche was estimated by recollection in 1617 women between the ages of 18 and 60 in Madrid and a nearby suburb, Pinto. The population of Pinto is working-class and the Madrid group, taken from residential neighbourhoods , belongs to the upper middle class. In both groups we found a diminution in average age at menarche, from 14.04 to 13.02 years in Madrid and from 14.55 to 13.16 years from about 1935 to about 1965 in Pinto. These changes have been more intense in the group which is less well-off economically, where living conditions have varied much more drastically.     

Uteroglobin in the developing rabbit conceptus in vivo and in vitro

Summary Uteroglobin (UGL) was measured in day- 4 to day-10 rabbit conceptuses by a competitive ELISA. Levels in blastocyst fluid, tissues, coverings and in the early fetus were determined separately. The total amount of UGL increased from 18.4 ng to 6.8 g per conceptus. The UGL content of individual day-6 blastocysts was studied in vitro. Culturing was carried out up to 60 h in Ham's F10 medium with polyvinylpyrrolidone as macromolecular component, with and without progesterone, and with progesterone plus estradiol. UGL was determined in the blastocyst fluids, tissues with coverings and in the culture media. After labelling with [³⁵S]-methionine, protein patterns of total blastocysts and of culture media were analysed by two-dimensional gel electrophoresis and fluorography. The morphology of cultured blastocysts was examined by electron microscopy. During 60 h of culture, the blastocysts expanded in diameter by 84%, and released 19% of their initial UGL content into the medium, independent of the hormonal substitution. Neither de novo synthesis, nor degradation of UGL was found: the protein remained unlabelled in fluorography, and its total quantity was not significantly different from that of non-cultured controls. Trophoblast, endoderm and embryoblast cells showed well preserved cell organelles and intercellular junctions, while the morphological differentiation of the germ layer was inhibited.