下调PTEN基因对偏头痛大鼠三叉神经节CREB的调节作用

本研究利用RNAi重组腺病毒(AdR-siPTEN)下调偏头痛大鼠三叉神经节的PTEN(phosphatase and tensin homolog deleted on chromosome ten)基因,探讨其对偏头痛大鼠行为学的影响,以及经Akt(serine-threonine kinase)信号途径对CREB(cAMP responseelement-binding protein)的调控情况。实验采用健康雄性SD大鼠,随机分为假手术组(Sham)、硝酸甘油模型组(GTN)、Ad-RFP非特异siRNA处理空载体对照组(Vehicle+GTN)、AdR-siPTEN下调组(AdR-siPTEN+GTN)。用AdR-siPTEN重组腺病毒对大鼠进行预处理,然后通过硝酸甘油(glyceryl trinitrate,GTN)法建立大鼠偏头痛模型,进行大鼠挠头和爬笼次数的检测,并用RT-PCR和Western-blot法进行相关基因的mRNA和蛋白检测。结果表明,当PTEN基因表达下调时,有效缓解了偏头痛导致的挠头和爬笼行为,并激活Akt信号途径,增加其下游作用因子CREB的表达,进而可能经"PTEN/Akt/CREB"信号通路影响神经突触可塑性,参与了偏头痛的发病机制。     

从临床到基础：硝酸甘油实验性偏头痛大鼠模型信度和效度评价

具有良好信度和效度的动物模型是从实验室到临床转译研究成功的保证,为进一步应用硝酸甘油（glycerol trinitrate,GTN）偏头痛大鼠模型,对其信度和效度进行评价。效度包括表面效度、建构效度、标准关联效度。衡量表面效度的标准是症状同源性。GTN偏头痛大鼠模型行为学表现与人类偏头痛有一定的相似性。建构效度主要指动物模型对理论假说的解释度,GTN模型复制了偏头痛的神经源性炎症及痛觉增敏,具有较好的建构效度。标准关联效度即预测效度主要表现为药理学反应及其在临床的干预实验。GTN模型对典型抗偏头痛药物麦角胺的反应较敏感,但是该模型的预测力效度仍未有效建立。GTN偏头痛大鼠在不同的地区、不同的实验室均已成功复制,表明其有较好的信度。     

归辛颗粒对偏头痛大鼠行为症状及血浆中CGRP含量的影响

目的:研究归辛颗粒(GXG)对硝酸甘油诱发的实验性偏头痛大鼠行为症状及颈静脉血浆中降钙素基因相关肽(CGRP)含量的影响并探讨其可能的作用机制。方法:采用SD大鼠,GXG以大、中、小三个剂量灌胃给药7d后,皮下注射硝酸甘油诱发大鼠偏头痛模型,观察各组大鼠行为学差异并采用放射免疫法测定其颈静脉血浆中CGRP含量的变化。结果:GXG可显著改善大鼠的行为症状,颈静脉血浆中CGRP含量明显低于模型组,与模型组比较差异有统计学意义(P<0.05或P<0.01)。结论:GXG可能通过调节偏头痛大鼠血浆中CGRP的水平,改善脑血管舒缩功能障碍,起到减轻偏头痛的作用。     

大鼠偏头痛模型的制作改进及评判指标选择

目的:对现有硝酸甘油型大鼠偏头痛模型不均一稳定缺点予以改进,探究更为合理、有效模型建立方法和特征指标。方法:采用雄性SD大鼠,分别使用硝酸甘油无水乙醇注射液和硝酸甘油混悬液,按照12 mg/kg、10 mg/kg、8 mg/kg剂量造模并观察记录其行为学变化。用ELISA法检测模型血清和脑组织5-HT变化,确定较为合理、可靠且均一的改良硝酸甘油偏头痛模型。结果:成功复制大鼠体偏头痛模型。使用硝酸甘油混悬液,皮下注射用量为10 mg/kg时模型效果较均一,造模后20~60 min之间有显著的行为学变化,出现抖身现象,并以倦怠结束。结论:与现有的偏头痛模型比较,最显著的改进之处在于使用硝酸甘油混悬液,延长了模型标志性行为动作的持续时间,以特定时间段内出现明确的行为变化作为观察指标,避免了剂型剂量和个体差异带来的模型效果差异,从而提高了模型的均一性。     

肢体缺血-再灌注大鼠脑组织iNOS基因表达的半定量检测

目的检测大鼠肢体缺血-再灌注后脑组织iNOS基因表达的变化.方法SD大鼠,随机分为肢体缺血-再灌注(I-R)组、肢体单纯缺血(I)组及正常对照(N)组,通过夹闭腹主动脉末端4?h,或/和开放2～24?h,复制I、I-R组动物模型,半定量RT-PCR方法检测脑组织iNOSmRNA表达的变化,免疫组化染色法观测脑组织内iNOS及过氧亚硝基阴离子(ONOO-)的硝基化产物硝基酪氨酸(NT)的生成与分布.结果N组脑组织iNOSmRNA未检出,I组及I-R组脑组织iNOSmRNA均有表达,再灌注2?h,iNOSmRNA表达量显著升高(P<0.01,vsN组),再灌注6?h达到高峰,随后下降,24?h仍有少量表达;I及I-R组脑组织均有iNOS阳性细胞,I-R组见于大脑皮层各区、海马、尾状核,I组仅见于皮层后肢区及尾状核.I-R组脑组织可见弥散分布的NT阳性神经元,I组偶见NT阳性神经元.结论大鼠肢体缺血-再灌后脑组织iNOS基因表达显著增强,且有时相变化特征.     

川芎嗪对脑缺血再灌注皮质神经元生存素表达的影响

目的探讨川芎嗪对脑缺血再灌注皮质神经元生存素表达的影响。方法大鼠60只分为正常对照组、假手术组、模型组、川芎嗪治疗1组(小剂量)和治疗2组(大剂量)。采用Bannister s颈动脉血引流法复制大鼠脑缺血再灌注动物模型并用腹腔注射川芎嗪治疗。缺血90min后,再灌注2h、24h和72h分别处死大鼠。脑组织4%多聚甲醛固定,石蜡切片;SP免疫组织化学染色。结果正常对照组survivin阴性,假手术组偶见阳性细胞,模型组大脑皮质出现较多的survivin阳性神经元,治疗1、2组在2h、24h、72h组survivin阳性细胞数密度增高,着色深(灰度值低);明显高于模型组。结论川芎嗪对脑缺血再灌注神经元中生存素表达有上调作用,并有量效关系和时相变化。     

Fos蛋白在脑挫伤皮质和海马中表达的研究

目的探讨脑挫裂伤后Fos因蛋白在皮质和海马中表达的变化.方法取成年大鼠45只分为正常对照组、实验对照组和模型组.用Feemey's自由落体法将其中32只复制脑挫伤动物模型;脑挫伤后30min、1h、2h、4h、8h、12h、24h和48h,分别取脑;石蜡切片,免疫组织化学染色.结果正常对照组脑内无Fos阳性细胞;实验对照组局部皮质有Fos微弱表达;模型组脑挫伤侧皮质和海马有Fos阳性表达.30min后已有阳性细胞;2～4h达高峰,阳性细胞多,而且着色较深,8～24h逐渐减弱,48h则不见阳性细胞.结论脑创伤可以导致伤侧皮质和海马c-fos基因蛋白过表达,而且各时间段表达强度不同,观察c-fos基因表达强度,可以作为临床提示脑部受伤时间的参考指标.     

蒺藜皂苷对动脉粥样硬化大鼠动脉壁ICAM-1、VCAM-1、PPARα、PPARγ基因表达的影响

观察全草蒺藜皂苷（tribu saponin from Tribulus terrestris,STT）对实验性动脉粥样硬化（atherosclerosis,AS）大鼠动脉壁中ICAM-1、VCAM-1、PPARα和PPARγ基因表达的影响,以探讨STT抗AS的机制。应用高脂饲料饮食配合注射维生素D,建立SD大鼠AS模型,并设立正常组、模型组、辛伐他汀组和蒺藜皂苷低、中、高剂量组。采用半定量RT-PCR的方法检测各组动物动脉壁中ICAM-1、VCAM-1、PPARα和PPARγ基因的表达,分析造模及各给药大鼠ICAM-1、VCAM-1、PPARα和PPARγ基因表达的变化。与正常组相比,模型组ICAM-1和VCAM-1基因的表达量明显增加（P〈0．01）,而PPARα和PPARγ基因的表达量明显降低（P〈0．01）;与模型组相比,辛伐他汀及各STT药均能降低ICAM-1和VCAM-1基因的表达量（P〈0．01～P〈0．05）,并能增加PPARα和PPARγ基因的表达量（P〈0．01）。提示STT能下调实验性AS大鼠动脉壁ICAM-1和VCAM-1基因的表达及上调PPARα和PPARγ基因表达,这可能是STT抗AS的作用机制之一。     

MK801对大鼠肢体缺血/再灌注致脑组织发生细胞凋亡的影响

目的:探讨肢体缺血/再灌注(LI/R)后,脑组织损伤的发生及MK801的影响。方法:采用文献[4]方法复制大鼠肢体缺血再灌损伤模型,给予MK801处理,观察各组动物脑组织中丙二醛(MDA)含量的变化,TUNEL法检测细胞凋亡情况,免疫组化和Western印迹法检测凋亡相关因子Bcl-2、细胞色素C(cytoC)、Caspase-3表达的变化。结果:大鼠LI/R后,脑组织中MDA含量升高,中脑红核区有大量胞浆呈棕色的Bcl-2、cytoC、Caspase-3蛋白阳性细胞分布,且细胞凋亡明显增加。MK801干预组与LI/R组相比MDA含量显著下降,Bcl-2、cytoC、Caspase-3蛋白表达降低,差异显著,且细胞凋亡相应降低。结论:凋亡相关因素Bcl-2、cytoC、Caspase-3变化介导的细胞凋亡参与大鼠LI/R后所致脑损伤过程。减弱谷氨酸兴奋性毒性作用及氧自由基损伤、影响凋亡相关基因表达可能是MK801脑保护的机制之一。     

多发性脑栓塞对脑功能的影响

实验性多发性脑栓塞是在动物身上模拟出人类多处脑组织缺血造成病理及病理生理改变的动物模型。目前虽已建立了多种脑缺血动物模型,但国内外尚无多发性脑栓塞对大鼠脑功能影响的报道。本研究利用大鼠多发性脑栓塞模型,观察多发性脑栓塞后清醒大鼠的学习、记忆、神经症状和脑组织结构改变。1 材料与方法1.1 模型的制备 参考Kaneko等报道的方法加以改进。(1)取同种大鼠无菌自然干燥血凝块,研碎后经20μm筛孔     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.