高血糖通过氧化损伤加重局灶性脑缺血再灌注神经元损伤

目的:探讨在高血糖加重脑缺血再灌注损伤中神经元氧化损伤的作用及机制。方法:将SD大鼠分为正常血糖脑缺血再灌注组(正常血糖组)、糖尿病高血糖脑缺血再灌注组(糖尿病组)以及假手术对照组(假手术组),通过线栓大脑中动脉制备局灶性脑缺血再灌注损伤模型,于再灌注后1,7和14 d分别进行组织学、8羟基脱氧鸟苷(8-hydroxy-2’deoxyguanosine,8-OHdG)免疫组织化学、NeuN和8-OHdG免疫荧光双标记,对比观察各组神经元的氧化损伤。结果:正常血糖组再灌注1 d脑组织出现明显水肿,糖尿病组较正常血糖组有所加重,出现较多的固缩神经元;再灌注7 d正常血糖组神经元固缩和脑水肿明显减少,糖尿病组仍可见少数神经元固缩和脑水肿;再灌注14 d正常血糖组神经元固缩和脑水肿消失,胶质细胞增加,糖尿病组可见轻度脑水肿。免疫组化和免疫荧光双标记提示,再灌注1 d,正常血糖组及糖尿病组8-OHdG阳性细胞和阳性神经元数量均明显增加,高血糖组8-OHdG阳性细胞数量和阳性神经元均明显高于正常血糖组(P0.05)。再灌注7 d和14 d 8-OHdG免疫阳性细胞阳性神经元明显减少,但仍多于假手术组(P0.05)。结论:糖尿病高血糖加重脑缺血再灌注损伤,神经元的氧化损伤是高血糖加重脑缺血再灌注损伤的重要方式之一。     

高血糖经抑制磷酸化腺苷酸活化蛋白激酶加重脑缺血再灌注损伤

目的:探讨磷酸化的腺苷酸活化蛋白激酶(p-AMPK)在高血糖加重脑缺血再灌注损伤中的作用。方法:通过注射链脲佐菌素制备糖尿病高血糖模型,线栓法制备大脑中动脉阻塞(MCAO)再灌注模型;分为假手术组(sham组),正常血糖脑缺血再灌注24 h组(NM I/R 24 h组)、72 h组(NM I/R 72 h组),高血糖脑缺血再灌注24 h组(HM I/R 24 h组)以及72 h组(HM I/R 72 h组),采用组织学、免疫组织化学及免疫印迹等方法,比较观察脑组织的损伤及p-AMPK的表达。结果:NM I/R 24 h组、NM I/R 72 h组大鼠均可见神经功能缺失的表现,HM组大鼠神经功能缺失评分明显高于NM组。NM I/R 24 h组梗死区脑组织疏松水肿,神经元固缩;HM组大鼠脑组织疏松水肿及固缩神经元较NM组大鼠明显增加;与NM I/R 72 h组比较,HM组大鼠仍存在脑组织疏松水肿,较多固缩神经元。免疫组织化学显色和免疫印迹结果可见,I/R 24 h和I/R 72 h,HM组p-AMPK相对蛋白量明显低于NM组。p-AMPK定位观察可见,p-AMPK与神经元共表达,但不与星形胶质细胞共表达。结论:糖尿病高血糖加重大鼠局灶性脑缺血再灌注损伤,可能与神经元磷酸化腺苷酸活化蛋白激酶减少有关。     

肢体远程缺血后处理促进局灶性脑缺血再灌注大鼠皮质区热休克蛋白70的表达

目的　观察肢体远程缺血后处理（LRIP）对局灶性脑缺血再灌注损伤大鼠皮质梗死区周围神经元、血管内皮细胞以及星形胶质细胞热休克蛋白70（Hsp70）的表达变化,探讨LRIP发挥脑保护作用的可能分子机制。方法　健康成年SD大鼠,随机分为假手术组（sham）、局灶性脑缺血再灌注模型组（I/R）、LRIP组。实验采用线栓法建立局灶性大脑中动脉脑缺血(1h)再灌注模型(MCAO),大鼠脑缺血再灌注即刻行双下肢股动脉橡皮筋结扎10min,放松10min,重复3次建立LRIP组模型。于再灌注1d、3d分别断头取脑,Zea longa评分作为判断MCAO模型成功的标准,Garcia神经行为学评分方法检测大鼠神经损伤程度,TTC检测脑梗死体积,Western blotting检测Hsp70蛋白表达含量, 免疫组织化学和免疫荧光技术,用于检测皮质梗死区周围Hsp70阳性表达细胞的数目、部位以及类型。结果　应用LRIP后,LRIP组与I/R组比较,神经行为学评分明显增加（P<0.05）、脑梗死体积显著降低（P<0.05）,Hsp70蛋白表达明显增加,其中1d组无统计学意义（P>0.05）,3d组有显著统计学意义（P<0.01）,Hsp70阳性表达主要在梗死区周围神经元、血管内皮细胞和星形胶质细胞突起。结论　LRIP可明显改善脑缺血后神经行为学功能、降低脑梗死体积,根据本实验结果我们推测此作用可能与LRIP上调皮质梗死区周围神经元、血管内皮细胞和星形胶质细胞Hsp70表达有关。     

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。     

大鼠局灶性脑缺血再灌注病灶及周围区PAI-1表达

目的:探讨大鼠局灶性脑缺血再灌注后病灶及周围区Ⅰ型纤溶酶原激活物抑制剂(PAI-1)的表达与脑微血管结构改变的关系。方法:采用光镜、电镜、免疫组织化学、Westernblot等技术,观察大鼠局灶性脑缺血再灌注不同时期病灶及周围区脑微血管结构改变及PAI-1表达。结果:大鼠局灶性脑缺血再灌注6h、3d组病灶及周围区脑微血管外间隙水肿及出血,脑微血管基底膜大量破坏,同时再灌注6h、1d组PAI-1表达低于正常对照组,密度值分别为0.16±0.43和0.33±0.61,与对照组(2.19±1.03)差异显著(P＜0.05)。再灌注后期7d组、14d组脑微血管内皮细胞增生,同时PAI-1表达增加,密度值分别为9.48±1.76和8.61±1.35,明显高于对照组(P＜0.01)。结论:大鼠局灶性脑缺血再灌注病灶及周围区脑水肿及出血以6h至3d最严重。PAI-1表达降低可能是导致脑微血管基底膜破坏的原因之一。再灌注后期PAI-1表达增加可能参与脑微血管的再生。     

局灶脑缺血再灌注区脑微血管基底膜损害及uPA、uPAmRNA表达的实验研究

目的:探讨脑缺血再灌注区脑微血管结构损害特征及发生机制。方法:应用光镜、透射电镜、免疫组织化学、原位分子杂交等技术,观察易卒中型肾血管型高血压大鼠局灶脑缺血2h再灌注6h至7d,再灌注区脑微血管结构改变、尿激酶型纤溶酶原激活物(uPA)表达。结果:局灶脑缺血再灌注区的脑水肿加重及并发出血以再灌注12h至3d最为严重,脑微血管基底膜溶解、缺损。同时使基底膜及细胞外间质降解的主要酶类uPA及uPAmRNA表达增加,以再灌注12h至3d达高峰。结论:脑缺血再灌注区脑微血管基底膜破坏是导致再灌注后脑水肿、出血的主要病理基础,内皮细胞、胶质细胞uPA表达的增加可能是引起微血管基底膜及细胞外间质损害的主要机制之一。     

大鼠星形胶质细胞在高血糖脑缺血再灌注损伤中的变化

目的:探讨星形胶质细胞在高血糖脑缺血再灌注损伤中的变化规律。方法:采用链脲佐菌素(STZ)诱导Ⅰ型糖尿病高血糖大鼠模型,通过双侧颈总动脉夹闭联合股动脉放血法建立全脑缺血再灌注模型,应用组织学、免疫荧光、组织化学及Western Blot方法,对比观察糖尿病高血糖脑缺血再灌注组(简称糖尿病组)与正常血糖脑缺血再灌注组(简称正常血糖组)在脑缺血15 min、再灌注1 h和6 h大脑额叶皮质区神经元、星形胶质细胞组织学变化及GFAP的表达。结果:正常血糖组再灌注1 h脑组织出现轻度水肿;再灌注6 h脑水肿加重,出现神经元固缩;再灌注1 h,糖尿病组病变与正常血糖组基本相同,再灌注6 h脑水肿加重,固缩神经元进一步增加。再灌注1 h和6 h,糖尿病组Nissl体平均光密度值明显低于正常血糖组(P<0.05)。脑组织GFAP免疫荧光检查可见,再灌注6 h正常血糖组GFAP免疫阳性细胞明显增加。糖尿病组再灌注1 h和6 h,出现GFAP阳性星形胶质细胞数目增加(P<0.05),胞体显著增大,突起增长、增粗。Western Blot结果可见,糖尿病组GFAP的表达明显高于正常血糖组。结论:糖尿病高血糖脑缺血再灌注能够加重神经元损伤,星形胶质细胞出现更明显的数量增加和GFAP表达。     

人参皂甙Rd对成年大鼠脑梗死后新生血管生长的影响

目的:研究人参皂甙Rd(Ginsenoside Rd,GSRd)对成年大鼠脑梗死后新生血管生长的影响并探讨其可能机制。方法:96只成年雄性Sprague-Dawley大鼠,体质量280~300 g,采用线栓法阻断右侧大脑中动脉制作局灶性短暂性大脑中动脉栓塞模型(focal transient middle cerebral artery occlusion,MCAO)。随机分为4组:sham、sham+GSRd、MCAO对照组、MCAO+GSRd治疗组,每组24只,术后7 d和14 d使用RECA-1单克隆抗体免疫组化法标记血管内皮细胞,计算缺血梗死区周围微血管密度和分支点,Western Blot方法测定脑缺血皮层血管内皮生长因子(vascular endothelial growth factor,VEGF)和缺氧诱导因子-1α(hypoxia-inducible factor 1 alpha,HIF-1α)的蛋白表达水平。结果:(1)免疫组化结果显示:MCAO损伤7、14 d时,GSRd治疗组梗死区周围微血管密度分别为755.3±65.5/mm2和790.8±53.9/mm2,较单纯手术组(589.7±28.9/mm2和636.7±22.6/mm2)比较,均显著增多(P<0.001);而GSRd治疗组周围微血管分支点在7、14 d时分别为341.7±40.4/mm2和363.5±39.7/mm2,亦比单纯手术组(197.2±26.6/mm2和276.0±42.9/mm2)显著增多(P<0.001);(2)Western Blot结果显示:GSRd治疗组的VEGF及HIF-1α表达量显著高于单纯手术组和假手术组(P<0.05)。结论:人参皂甙Rd显著促进大鼠脑梗死区血管生长,其机制可能与增强脑梗死后VEGF、HIF-1α的表达相关。     

红景天苷对局灶性脑缺血再灌注大鼠神经生长相关蛋白的影响

目的研究红景天苷对局灶性脑缺血/再灌注损伤(I/R)后神经生长蛋白(GAP-43)表达的影响。并探讨其可能的机制。方法Wistar大鼠随机分为假手术组、I/R模型组和红景天苷组,采用线栓法制造大鼠大脑中动脉阻塞/再灌注(MCAO/R)模型,MCAO2h后恢复再灌注。用免疫组化方法检测再灌注后1d、3d、7d、14d、21d的与个时间点GAP-43的表达。结果红景天苷明显减小梗死灶范围,梗死灶周围皮质神经元损伤明显减轻。假手术组中枢神经系统GAP-43表达较少,I/R组GAP-43阳性表达,在术后1d开始增高,3d表达最强,高水平维持到7d,14d明显降低,但未降至正常水平。红景天苷组各个时间点GAP-43阳性表达强度均显著高于I/R对照组(P<0.05)。结论红景天苷能提高脑缺血/再灌注后GAP-43的表达,促进轴突生长,易化脑缺血再灌注损伤后神经可塑性。     

rhAng-1通过PKCα/MLC通路影响局灶性脑缺血再灌注大鼠血脑屏障通透性

目的研究重组人血管生成素1(rhAng-1)对局灶性脑缺血再灌注大鼠血脑屏障内皮细胞骨架的影响。方法大鼠随机分8组:(1)假手术组;(2)缺血组;(3-5)生理盐水+缺血再灌注12h/48h/7d组;(6-8)Ang-1+缺血再灌注12h/48h/7d组。用伊文思兰渗透性实验检测血脑屏障通透性;Westernblot法检测微血管内皮细胞PKCα和p-MLC的表达。结果 Ang-1可明显降低局灶性脑缺血再灌注大鼠血脑屏障通透性,可使脑微血管内皮细胞PKCα和p-MLC表达水平减少。结论 Ang-1降低血脑屏障通透性与降低PKCα/MLC通路表达相关。     

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.     

Intestinal helminthiasis in school children in Haiti in 2002

A survey on intestinal helminths in school children was conducted in Haiti in 2002. This first nationwide study involving the entire country was stratified by department according to urban and rural zones using the cluster method. Focusing on elementary school children (n=5792; age range 3 to 20 years), it involved 26 urban and 49 rural schools randomly selected. Stools were preserved in formalin and examined by the Ritchie technique. Thirty-four per cent of stools (1981/5792) tested positive for intestinal helminths with the following parasites identified: Ascaris lumbricoides (27.3%), Trichuris trichiura (7.3%), Necator americanus (3.8%), Hymenolepsis nana (2%), Taenia sp. (0.3%) and Strongyloides stercoralis (0.2%). The helminth prevalence was higher in rural (38.4%) compared to urban areas (30%). There was no significant difference in prevalence by sex and age. The importance of geohelminths changed from one department to another with the highest prevalence found in the Southern department of Grande Anse (73.7%) and the lowest prevalence in the Center department (20.6%). Five out of the country's nine departments had a similar prevalence varying from 25.5% to 28.2%. Intestinal helminthic polyparasitism was observed in a percentage of infested school children comprise between 3.4% and 28.6% according in relation to the geographical area. A program to fight against geohelminths in school children should be initiated as a public health priority. Albendazole is the drug of choice. Frequency of drug distribution should be based on the prevalence of geohelminths in each department.     

Experience in adult population in dengue outbreak in Delhi

A dengue outbreak has recently hit the Indian capital. We studied the clinical profile of adult patients. Five hundred and sixty patients of dengue infection were admitted in a specially created ward according to the criteria laid down by WHO. Haematemesis (28.28%), epistaxis (26.78%) and malena (14.28%) were some of the common presentations. Similarly lymphadenopathy, especially cervical (30.89%), palatal rashes (26.96%) and hepatomegaly (23.75%) were the most commonly encountered findings on physical examination. Most of the cases were of dengue fever with haemorrhage and only 2.5% cases were classified under dengue haemorrhagic fever or dengue shock syndrome. The average hospital stay was 3.4 days but only 9.8 hours in the eleven patients who died, suggesting their late arrival in preterminal situation giving little time for resuscitation. Thrombocytopenia was not a feature and only 12.85% patients had platelet count less than 70,000/cmm. Most of the patients who were admitted with thrombocytopenia, showed normalization in their platelet counts in next few days. Serological examination demonstrated evidence of recent dengue infection in 41.17% patients. Few patients required blood or platelet concentrate transfusion. Eleven patients died, three due to DIC, one of intracranial haemorrhage and seven due to massive gastric haemorrhage. Rest of the patients recovered completely. Thus we can conclude that recent outbreak in Delhi was of dengue fever with haemorrhage and mortality was very low in patients who came early to the hospital.     

Changes in the hypothalamic nuclei in in experimental allergy

Summary In rabbits subjected to prolonged sensitization and in which the Arthus phenomenon was induced there was a marked reaction of the hypothalamic nuclei. Staining by Gomori's method indicated a cellular swelling, loss of granules, and protoplasmic vacuolization in the supraoptic nucleus. There was a considerable increase in the size of the cross-sectional area of the cells. The same effects were much less well shown in the paraventricular nucleus. These results show that marked signs of increased neurosecretion developed in the animals at the height of the Arthus phenomenon.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten Éksperimental'noi biologii i Meditsiny, Vol. 55, No. 4, pp. 110–113, April, 1963.     

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.