NOS活性在大鼠不同脑区的研究

一氧化氮（NO）作为神经递质或调质已经确定。一氧化氮合酶（NOS）活性大鼠不同脑区的定位是本研究的重点。采用NADPHd酶组织化学方法,对大鼠海马、脑干内NOS的活性进行观察。结果显示：海马（CA1－CA3区）NOS为阳性（＋）、其中CA2为强阳性（＋＋＋）;非脑神经核（红核、黑质）为中等阳性（＋＋）;而脑神经核（动眼神经核、动眼神经副核、面神经核、展神经核）NOS为阳性（＋）;脑桥网状结构为阳性（＋）;缝核群为阳性（＋）;第三脑室和第四脑室脉络丛为阳性（＋）。     

甲醛炎性痛增强大鼠海马NOS表达和NO生成

目的：观察甲醛炎性痛过程中大鼠痛行为、海马一氧化氮合酶（NOS）活性及一氧化氮（NO）含量的变化以及变化的时程及区域特征。方法：采用辐射热甩尾法测定大鼠痛阈变化;采用NADPH—d组织化学法和硝酸还原酶法分别测定大鼠海马NOS表达和No含量。结果：皮下注射甲醛溶液后,大鼠出现伤害性感受反应及痛阈降低。注射甲醛后6h,海马CA1、CA2～3区及DG区NOS阳性细胞数目、阳性细胞染色深度均显著增加。海马NO含量亦显著增加;注射甲醛后12h时这些改变最为显著,48h时恢复至对照组水平。结论：甲醛炎性痛可诱导海马NOS活性增强及NO生成增多．这种改变可发生在海马各区．并具有一定的时程特征。     

鞘内注射MK-801对炎性痛大鼠海马NOS表达及NO含量的影响

目的：观察鞘内给予N-甲基-D-天门冬氨酸（NMDA）受体拮抗剂MK-801对足底注射甲醛诱导的自发痛反应和海马一氧化氮合酶（NOS）表达及一氧化氮（N0）含量的影响,探讨炎性痛诱导海马NO产生增多的机制。方法：通过观察舔足反射时间反映大鼠自发痛程度;采用NADPH—d组织化学法测定大鼠海马NOS表达;硝酸还原酶法测定海马组织NO含量。结果：足底注射甲醛后动物即出现舔、咬、摇动注射侧脚掌等自发痛相关表现,预先鞘内注射MK-801可使大鼠第二时相自发病程度显著降低,但对第一时相痛反应程度无明显影响。注射甲醛后12h时,海马CA1、CA2～3区及DG区NOS阳性细胞数目、阳性细胞染色深度均显著增加,海马组织NO含量显著增加;预先鞘内注射MK-801,可使甲醛炎性痛大鼠海马各区NOS阳性细胞数目明显减少,阳性细胞染色深度明显变浅,海马NO含量明显降低。结论：鞘内注射MK-801可逆转甲醛炎性痛诱导的海马NOS表达及NO产生的增加,表明甲醛炎性痛诱导的海马NO产生增加主要是由于伤害性信息传入所引起。     

锌对急性缺氧小鼠海马NOS和nNOS水平的影响

目的：观察锌对急性缺氧小鼠海马一氧化氮合酶（nitric oxide synthase,NOS）和神经元型一氧化氮合酶（neuronal NOS,nNOS）阳性神经元的影响,以探讨锌抗脑缺氧的作用机制。方法：复制小鼠急性缺氧模型,采用NADPH-d组织化学和nNOS免疫组织化学方法,研究给锌组和不给锌组急性缺氧小鼠海马各分区NOS和nNOS阳性神经元数量的变化。结果：给锌组比不给锌组小鼠缺氧耐受时间显著延长,差异有显著性（P〈0．05）;海马及其CA1区NOS和nNOS阳性神经元的数量明显减少,差异有显著性（P〈0．05）。结论：急性缺氧时锌通过减少海马NoS和nNOS水平而发挥其抗脑缺氧作用。     

海马NMDA受体和NOS在慢性应激性抑郁发生中的作用及其相互关系

运用慢性不可预见性温和应激（chronic unpredicted mild stress, CUMS）建立抑郁动物模型,通过海马内微量注射、动物行为学观察及免疫组织化学方法检测海马内一氧化氮合酶（nitric oxide synthase,NOS）表达的变化,探讨CUMS诱发抑郁与海马谷氨酸N-甲基-D-天冬氨酸（N-methyl-D-aspartic acid,NMDA）受体、一氧化氮合酶（nitric oxide synthase,NOS)的关系。结果发现：CUMS组大鼠表现出抑郁样行为变化,海马NOS表达显著升高;海马微量注射NMDA受体激动剂,动物行为学表现与CUMS组相同,NOS表达升高;海马微量注射非竞争性NMDA受体拮抗剂MK-801能明显改善应激引起的抑郁样行为表现,并降低海马NOS表达。这些结果表明慢性不可预见性应激可能使谷氨酸（glutamic acid,Glu）过量释放,NMDA受体过度激活,NOS高表达,NO过量产生,损伤海马神经元,导致抑郁发生。     

人参皂甙Rb3抗缺血低氧性脑损伤及其机制的研究

目的：利用整体动物、离体海马脑片、原代培养的海马神经细胞作为实验对象,研究人参皂甙Rb3抗缺血低氧性脑损伤作用及相关机制。方法：①在密闭三角烧瓶中观察小白鼠低氧存活时间。②在离体海马脑片上观察顺向群锋电位（OPS）的恢复率、恢复程度及低氧损伤电位（HIP）出现率。③低压舱作为全脑低氧模型,采用NADPH-d法,观察一氧化氮合酶（NOS）阳性细胞数、平均光密度值。④采用原代培养海马神经细胞低氧模型,观察神经细胞形态、乳酸脱氢酶（LDH）漏出率及总NOS、结构型一氧化氮舍酶（cNOS）、诱导型一氧化氮合酶（iNOS）活性。结果：①小白鼠低氧存活时间人参皂甙Rb3组较正常组明显延长,并具有剂量依赖性,以10mmol／L组最为显著。②人参皂甙Rb,对海马脑片缺血时CAl区诱发场电位的影响：对照组海马脑片模拟缺血时全部出现HIP,复氧供糖1h后OPS恢复率为0％,OPS恢复程度平均为缺血前的5,42％。使用人参皂甙Rb3后,HIP出现率明显下降,复氧供糖1h后OPS恢复率、OPS恢复程度均增加,以60μmol／L作用最为显著。③人参皂甙Rb3使海马CAI区锥体细胞层NOS阳性细胞数、平均光密度值下降。④人参皂甙Rb3能使细胞外液中LDH的漏出减少、总NOS、iNOS活性下降。结论：人参皂甙Rb,对缺血低氧性脑损伤有保护作用,并具有剂量依赖性,作用机制可能与降低低氧损伤时细胞膜通透性,减少NOS表达,抑制NOS的活性,尤其是诱导型NOS活性有关。     

大鼠中缝背核内一氧化氮合酶阳性原位触液神经元的观察

通过研究大鼠中缝背核内远位触液神经元与一氧化氮合酶（NOS）阳性神经元的关系。以探讨一氧化氮（NO）是否是触液神经元在脑-脑脊液之间的信息传递有关,选用霍乱毒素亚单位B标记的辣根过氧化物酶（CB-HRP）逆行追踪与还原型尼可酰胺腺嘌呤二核苷磷酸（NADPH）黄递酶反应,CB-HRP标记的神经元密集分布于中缝背核,可见CB-HRP/NADPH-d双重标记的神经元,中缝背核内一部分远位触液神经元存在NOS,这些神经元在脑-脑脊液之间的信息传递中起着很重要的作用。     

诱导型一氧化氮合酶介导β淀粉样蛋白在体神经毒性

目的：探讨一氧化氮合酶（NOS）及一氧化氮（NO）在β淀粉样蛋白（Aβ）神经毒性和Alzheimer病（AD）发病机制中的介导作用。方法：应用行为学及病理学方法,观察海马注射Aβ1－40对大鼠Y迷宫学习记忆的影响及对局部神经元的损伤作用;观察特异性诱导型一氧化氮合酶（iNOS)抑制剂胍氢酶（AG）及特异性神经元型一氧化氮合酶(nNOS)抑制剂7－硝基吲哚（7－NI）腹腔注射对海马内注射Aβ1－40神经毒性的干预,结果：海马注射Aβ1－40后,大鼠Y迷宫学习记忆能力及海马局部神经元明显受损,特异性iNOS抑制剂AG能够阻止Aβ1－40海马注射对大鼠学习记忆和局部神经元的损伤作用,而特异性nNOS抑制剂7－NI无此干预效应。结论：iNOS/NO参与了在体条件下对Aβ神经毒性的介导,在AD发病机制中具有重要作用。     

产前束缚应激子代大鼠海马神经颗粒素表达降低

神经颗粒素（neurogranin,NG）是脑特异性突触后蛋白,参与在学习记忆功能中起核心作用的信号转导通路及突触可塑性。本研究旨在探讨产前束缚应激对子代大鼠海马NG表达的影响。连续7d对孕晚期大鼠进行束缚应激,建立产前束缚应激模型,分为对照雌、雄组,应激雌、雄组。采用免疫组化方法观察NG在产前束缚应激子代大鼠海马不同亚区的分布特点;采用蛋白免疫印迹方法检测产前束缚应激子代大鼠海马NG蛋白的表达。结果显示：各组子代大鼠海马各区均有NG蛋白表达,CA1和CA3区表达高于齿状回（dentate gyrus,DG）;应激组雌、雄子代大鼠海马NG的表达明显低于对照组（P〈0．01）,应激组雌性子代比雄性子代减少更显著,对照组雌、雄子代之间无差异。免疫组化与蛋白免疫印迹方法所得结果一致。上述结果表明,NG在产前束缚应激子代大鼠海马表达降低,并且雌性比雄性降低明显,NG对产前束缚应激子代大鼠有差异性调制,NG表达减少可能与产前束缚应激子代大鼠学习记忆能力下降有关。     

围产期食物限制对子代成年大鼠海马CA1区突触可塑性的影响

围产期食物限制导致子代大鼠学习和记忆能力等的神经生物学变化,但其机制并不清楚。将成年Wistar雌性大鼠与雄性大鼠同笼,受孕后随机分为对照组 (n=9) 和食物限制组 (n=8) 。对照组母鼠在妊娠期和哺乳期自由进食和饮水,食物限制组母鼠从妊娠的第7天到子代大鼠出生后21天进行食物限制,食物限制量为对照组大鼠的50%。子代雄性大鼠成年后,通过Morris 水迷宫测试空间学习和记忆能力。之后,在海马CA1区在体记录场兴奋性突触后电位 (field excitatory postsynaptic potential,fEPSP),并采用免疫组织化学方法观察海马CA1区神经元型一氧化氮合酶 (nNOS) 阳性细胞密度的变化。结果表明,围产期食物限制降低了子代大鼠出生后第1、7、10、14和21天的体重,并减弱了成年子代大鼠的学习和记忆能力,海马CA1区fEPSP的斜率和nNOS阳性细胞的密度也明显降低。结果提示,围产期食物限制可能通过抑制NO的产生降低了海马突触可塑性,从而影响了子代大鼠的学习和记忆能力。     

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.