藏药对脑缺血大鼠海马CA3区锥体细胞超微结构的影响

采用夹闭大鼠双侧颈总动脉制作全脑缺血再灌流损伤动物模型,对比观察藏药五根散治疗前、后对其海马CA3区锥体细胞超微结构改变的影响.结果,未治疗组大鼠海马CA3区锥体细胞出现核膜内陷,核染色质分布不均且集聚成块状向核膜边集,胞质水肿,细胞器减少,粗面内质网扩张,核糖体脱失,线粒体膜轮廓不清,嵴断裂或空泡化,而治疗组大鼠海马CA3区锥体细胞超微结构大致正常.表明脑缺血后血供恢复期海马CA3区锥体细胞发生明显的超微结构改变,藏药五根散治疗可使海马病变向正常逆转,为藏药五根散防治脑血管病引起认知功能障碍后遗症提供了形态学依据.     

硝基苯染毒致小鼠脑的毒性作用

为探讨硝基苯染毒致小鼠脑的毒性作用,用灌胃的方法对试验小鼠进行了硝基苯染毒,染毒剂量分别为26、52、105 mg/kg,每日染毒1次,共30 d.于末次染毒后第2 d将小鼠脱颈椎处死,立即取出脑,检测SOD和GSH-Px活性和MDA含量,并对其显微及超微结构进行了观察.结果,硝基苯对小鼠脑有明显的毒性作用,主要表现为大脑血管间隙扩大,周围神经纤维疏松;小脑、海马区部分浦肯野氏细胞核固缩、核溶解,锥体细胞核固缩;神经细胞肿胀,线粒体明显肿胀,粗面内质网形态扩张;大部分胶质细胞电子密度增加,胞核变小、核固缩,胞质内细胞器明显减少;有些神经纤维脱髓鞘,神经微丝溶解;随着染毒剂量的加大,MDA含量逐渐升高,CAT和SOD活性不断显著降低.结果表明,硝基苯可以通过氧化应激和诱发细胞凋亡对小鼠脑组织造成损伤.     

人工感染鸡包涵体肝炎病毒的鸡胚病理学观察

用３２只１１日龄ＳＰＦ鸡胚，随机分组，分别接种禽腺病毒（ＡＡＶ）２、３、４、５、８型种毒和野毒ａ、ｂ株悬液０．２ｍｌ／只。对接种后２４小时以后死亡的胚和１８日龄时扑杀的全部鸡胚进行大体病理变化、病理组织学变化和超微结构病理变化观察。试验结果表明，试验各组的鸡胚均发育不良，表现为胚体瘦小，羽毛稀少，ＡＡＶ－２、３、４、５、８型和野毒ａ、ｂ株均能对鸡胚致病，主要病变均为坏死性肝炎，在肝细胞核内和胞浆中形成嗜碱性或嗜酸性包涵体；透射电镜观察，试验各组肝细胞中均可见到病毒颗粒，核内可见电子密度致密的病毒前体物质，病毒直径６０～７０ｎｍ，无囊膜。ＡＡＶ－３型和野毒ｂ株在细胞核、胞浆、线粒体病毒颗粒排列为晶格状，其它各型多为散在分布。肝细胞超微结构变化主要表现为线粒体、内质网、高尔基复合体扩张甚至破裂，核糖体脱失，核染色质边集、浓缩和溶解，核膜破裂而核崩解。     

宠物犬犬瘟热的病理组织学观察

采取未治愈的8例犬瘟热病犬的肺、肝、脾、脑等组织,石蜡包埋切片,HE染色,然后对切片进行了病理组织学观察.结果显示,肝细胞以及胆管上皮细胞中发现细胞浆包涵体,胃腺上皮细胞肿胀坏死,部分胞浆溶解呈空泡状,在少数腺上皮细胞内可见细胞浆包涵体,黏膜上皮细胞肿胀、脱落,杯状细胞增多,肺泡壁结构几乎消失,少数变性的支气管、细支气管上皮细胞内有核内包涵体,神经细胞肿胀变性.周围的毛细血管中有微血栓形成,脊髓灰质中神经细胞肿胀,染色质溶解,神经细胞周围水肿,脾淋巴细胞明显减少,淋巴小结不明显,有明显的萎缩,淋巴细胞减少.     

硝基苯对小鼠脾的毒性作用

为探讨硝基苯对小鼠脾的毒性作用,采用灌胃的方法对试验小鼠用硝基苯染毒,染毒剂量分别为26 mg/kg、52 mg/kg、105 mg/kg,每天染毒1次,共30 d.于末次染毒后第2 d将小鼠脱颈处死,立即取出脾检测抗氧化指标MDA、SOD、GSH-Px和T-AOC,并对其进行了显微和超微结构的观察.结果,随着染毒剂量的加大,MDA含量逐渐升高,SOD、GSH-Px酶活性和T-AOC逐渐降低;与油对照组相比,各剂量组均表现为差异极显著(P＜0.01);光镜下白髓数量减少,体积变小,生发中心不明显,高剂量组能见到少量的凋亡细胞;电镜下白髓区淋巴细胞染色质聚集,核周隙增宽,核边集现象增多,高剂量组可见个别细胞核膜破损,核内容物外溢.结果表明,硝基苯对脾具有明显的毒性作用,能够诱发机体氧化应激和脾淋巴细胞凋亡,氧化应激与细胞凋亡的发生存在一定关系.     

犬出血性肠炎病毒的形态学鉴定

对分离自以呕吐、便血为特征的病犬粪的病原,接种于原代乳猫肾细胞,不同培养时间采样进行电镜观察,结果表明感染细胞有明显微结构改变一细胞核异染色质趋边、核内包涵体形成,或聚集或分散的病毒样颗粒出现。经免疫电镜证实,细胞培养冻融液里的病毒颗粒为球形呈聚集状态,大小18～26nm,有空心及实心两种形态,考虑到该病毒的一些生物学特性,应为细小病毒科成员。     

高铜对雏鸡器官组织病理损害的研究

将420只1日龄艾维茵健雏,随机分为7组,分别饲以含铜量11 mg/kg的基础日粮和含铜量分别为100、200、300、400、500和600 mg/kg的6种高铜日粮6周,研究高铜对雏鸡的病理损害。结果显示,日粮含铜100和200 mg/kg对雏鸡有促生长作用。日粮铜水平达300 mg/kg以上时,对雏鸡器官组织造成不同程度的病理损伤,表现为肌胃角质层增厚呈黄褐色；肝呈浅黄色或深褐色,肝细胞脂肪变性；消化道上皮细胞变性坏死；免疫器官和肾、心脏、胰腺、大脑等器官的实质细胞肿胀；淋巴免疫器官体积缩小,淋巴细胞数量减少。超微结构观察发现,肝细胞胞浆和胞核内见有数量不等、大小不一的高电子密度的沉积物；凋亡的淋巴细胞染色质呈花瓣样、半月形或环形,聚集在核膜下。表明,肝、消化道和免疫器官是高铜损害的主要靶器官。     

催产素、加压素神经元在奶山羊下丘脑的分布

本文以硫代硫酸醛复红法(TAF)来显示催产素、加压素神经元的形态特征及其在奶山羊下丘脑中的分布。结果表明:这两种神经元均为多极神经元。胞体较大,呈圆形、梭形、梨形等形态,胞质中有丰富的分泌颗粒,它们集中分布在视上核(SON)和室旁核(PVN)中,有少量的神经元可分布在室周核、环状核、穹窿周核和交叉上核。个别的可出现在视前区、下丘脑前区、下丘脑外侧区、前联合核等部位。在一些主要分布的核团内还可见到大量的神经纤维和毛细血管,有的神经纤维内可明显地见到串珠状的分泌颗粒。神经元的突起及神经纤维有较明显地走向第三脑室和附近血管的趋势。因此,催产素和加压素有向脑室和血管释放的可能性。在细胞外还可见到较多的阳性颗粒,成堆分布,这些可能是催产素和加压素中的结合蛋白分离后被着色的结果,有待于进一步研究。     

猪伪狂犬病病毒变异株感染绵羊胚胎鼻甲上皮细胞的病毒形态发生和细胞超微结构观察

应用超薄切片和透射电子显微镜技术,研究猪伪狂犬病病毒(PRV)MQ18变异株感染绵羊胚胎鼻甲上皮细胞(OFTu)的病毒形态发生和超微结构变化。结果显示:病毒在细胞核内复制、增殖,形成核内包涵体,装配好的病毒通过核内膜获得初始囊膜,以出芽方式出核进入细胞质,在高尔基体区域进行加工修饰、二次获得囊膜后形成完整病毒粒子,以包裹有病毒粒子的空泡与细胞膜相互融合方式,将病毒释放到细胞外;细胞超微结构主要表现为细胞质内空泡增多,线粒体增生、肿大,空泡样变,粗面内质网扩张,高尔基体形态异常,细胞核染色质浓缩、边集,最后细胞破坏、裂解,可见细胞早期凋亡及自噬小体结构。本研究结果为阐明PRV的感染和致病机制提供了理论依据。     

17β-雌二醇对海马组织结构和GFAP表达的影响

为研究17β-雌二醇对脑的保护作用机制,以去卵巢大鼠为动物模型,采用甲苯胺蓝染色、免疫组织化学染色和透射电镜技术,观察了17β-雌二醇对海马组织结构和胶质纤维酸性蛋白表达的影响。结果显示:①与对照组、假手术组和去卵巢后补充雌激素组比较,在去卵巢组中,海马CA1～3区、齿状回神经元数量显著减少(P<0.05),CA4区神经元数量减少不显著(P>0.05);海马CA1～4区、齿状回星形胶质细胞数量增加不显著(P>0.05);海马CA1～4区、齿状回胶质纤维酸性蛋白表达增加,除CA4区与去卵巢后补充雌激素组之间无显著差异外(P>0.05),其余均差异显著(P<0.05);海马CA1区神经元、胶质细胞线粒体肿胀,神经元突触和突触囊泡减少,轴突变性;②与去卵巢组比较,去卵巢后补充雌激素组海马CA1～3区、齿状回神经元数量明显增加(P<0.05);海马CA1～4区、齿状回星形胶质细胞数量减少不显著(P>0.05);海马CA1～3区、齿状回胶质纤维酸性蛋白表达显著降低(P<0.05);保持了海马CA1区神经元和胶质细胞超微结构的正常。结果表明,17β-雌二醇能通过增加神经元数量,降低星形胶质细胞胶质纤维酸性蛋白表达,保持神经元和胶质细胞正常的超微结构,实现对海马的保护。     

中国—东盟建立对话关系20周年与中老关系

一、中国—东盟对话关系的成果中国—东盟对话关系可追述到1991年。1991年7月中国外交部长钱其琛作为马来西亚政府邀请的客人出席在吉隆坡举办的第二十四届东盟外长会议开幕式,中国对发展与东盟的互利合作关系表示出浓厚的兴趣。随着中国—东盟领导人会议于2003年10月在印度尼西亚巴厘岛举行并发表了     

世贸组织存在的问题及其发展前景

1 999年 1 2月 3日 ,举世瞩目的 WTO第三届部长级会议在美国西雅图无果而终 ,WTO因此遭到了成立 5年以来的最大挫折。“千年回合”受阻的直接原因是成员方在农业、反倾销、劳工标准和环保政策等议题上的巨大分歧 ,而分歧背后所反映出的问题更是发人深思。目前 ,WTO正面临着如何协调成员国之间利益关系的挑战 ,其宗旨的实现也有待于成员国各方的努力与呵护。     

Business as Usual

In the years since 9/11, there is no doubt that the emphasis of U.S. global strategy has been on counter-terrorism and the war in Iraq. During this period of time, the U.S. investment in strategic, political and military resources in the Middle East, Iraq, and the war on terror, which are the top priorities on the list of Bush＇s foreign policy, has been far greater than in any other fields. However, there are some in the U.S. who believe that China＇s rise has been much ignored by the U.S., due to the global war on terror （GWOT）, and that America should, in fact, be focusing more on China, not the Middle East. However, as we see it, China has by no means been ignored by the U.S., neither has China＇s rise been the result of U.S. ignorance.     

Sovereignty as Responsibility

This article examines the development of a new normative principle of international order, sovereignty as responsibility; its communitarian implications; and the ways in which the newly conceived responsibility of the “international community” to protect the people of states failing to live up to their responsibilities as defined by international norms can come to terms with the notion of democratic self-government.     

Terrorism as a strategy of insurgency

This essay describes terrorism as a mode of warfare and examines its unique characteristics, by comparing this method of struggle to other forms of violent conflict. It further emphasizes the role of terrorism as a strategy of insurgence and delineates the main strategic ideas by which terrorists have hoped to achieve their political objectives. The study evaluates terrorists’ success in obtaining political goals and the conditions which affect their ability to materialize their objectives.

The author concludes that the mode of struggle adopted by insurgents is dictated by circumstances rather than by choice, and that whenever possible, insurgents use concurrently a variety of strategies of struggle. Terrorism, which is the easiest form of insurgency, is practically always one of these modes.     

ESP as a means of communication

SUMMARY

Although the obstacles to communication and cooperation between the widely divergent groups in South Africa is formidable, there is a genuine desire to live together peacefully in our common fatherland.

Intercultural contact in the South African labour situation is a very complex phenomenon but is important because this is virtually the only area of South African society in which Black and White in particular, come into close contact with one another.

Typical intercultural problem areas in the organisation are: cultural differences, differing circumstances of life, system defects and grievances, high potential for conflict, and other communication stumbling blocks.

The essential conditions for intercultural communication are availability, willingness and purpose, to which the following aspects can be added: continuing communication; creation of common ground; adoption of the right attitude and creation of trust; visualisation of a common purpose; knowledge of the other, knowledge of the other's language; training; use of the right communication channels; knowing how to deal with trade unions, work committees, etc.; good supervision; consideration of unique needs and expectations; and other hints, most of which have basically to do with sensitivity and just good manners.

South Africans have to cope with unique challenges and therefore will have to envisage and develop an indigenous South African organisational style in which the best both cultures have to offer, are accommodated.     

广西经济现状和优势以及广西企业向东盟发展的策略

本文介绍广西的经济现状、优势,提出广西与东盟进行经济贸易合作的建议。