小麦黄花叶病毒的分离提纯及其血清学等特性

应用梯度离心和超速离心浓缩获得部分提纯的病毒制剂,产量约为7.45g/kg病叶提纯的病毒制剂的紫外吸收曲线呈典型的核蛋白吸收曲线,OD260/OD242和OD260/OD280的比值分别为1.24和1.38。病毒粒子呈线状,宽13—14nm,长度主要分布于250—300nm和550—700nm之间,1000nm以上的粒子也有检到。病毒外壳蛋白仅由一个分子量约为30Kd的亚基组成。在免疫电镜试验中、病毒粒子与日本WYMV抗血清发生强烈的血清学反应。新鲜病叶的超薄切片中可看到大量风轮体和膜状体。     

草莓伪温和黄边病毒的提纯技术研究

本研究比较了多种提纯方法,提出一个较理想的草莓伪温和黄边病毒（ＳＰＭＹＥＶ）提纯程序。病ＵＣ－４草莓叶经ＰＥＧ沉淀,蔗糖垫层差速离心,蔗糖密度梯度离心,可获得相当纯的病毒制剂。紫外检测呈典型的核蛋白吸收曲线,Ａ２６０ｎｍ／Ａ２８０ｎｍ＝１．２１,病毒得率为７－１０ｍｇ／ｋｇ病叶,病毒粒子电镜下观察,长６７０ｎｍ,宽１２～１３ｎｍ。     

温州蜜柑萎缩病毒提纯与抗血清制作及其应用

采用洋酸浆（Ｐｈｙｓａｌｉｓｆｏｒｉｄａｎａ）繁殖温州蜜柑萎缩病毒（ＳＤＶ）,改进提纯方法,经５％－２５％,酒石酸钾密度梯度离心获得的提纯制剂,在２２０－３００ｎｍ下呈单一吸收峰曲线,峰在２５９ｎｍ,谷在２３７ｎｍ,ＯＤ２５９／ＯＤ２３７＝１．６０,ＯＤ２５９／ＯＤ２８０＝１．７３,病毒得率约为１３ｍｇ／ｋｇ病叶,电镜观察各视野布满了直径约２６ｎｍ的球状病毒颗粒,病毒粒子外壳蛋白有两个组分,分子量     

大豆花叶病毒（SMV）抗原及抗血清制备

大豆花叶病毒（ＳＭＶ）汁液经正丁醇、氯仿混合液澄清，ＰＥＧ沉淀，差速离心提取病毒粗提液。再经琼脂糖凝胶层析柱纯化，得到病毒提纯液。电镜观察病毒粒子为线条状，长７３０－７５０ｎｍ，宽１３ｎｍ。提纯液用紫外分光光度计扫描，得到一条典型的核蛋白吸收曲线，同时以波长２６０ｎｍ的ＯＤ值计算病毒含量。用病毒提纯液免疫兔子，制得抗血清。通过回接试验在寄主植株显症，确认为大豆花叶病毒。     

侵染菠菜的芜菁花叶病毒鉴定

菠菜病毒分离物Ta-1可侵染甘蓝等8科25种植物,但不侵染心叶烟。病汁液和芜菁花叶病毒抗血清呈阳性反应。光学显微镜下观察到受病毒侵染的细胞内有不定形内含体。从超薄切片见到细胞质中有风轮状内含体存在。电镜观察其粒子形态为均一的线状病毒,大小为700—760×10—12.5nm。部分提纯病毒紫外吸收呈典型核蛋白吸收曲线。SDS—PAGE法测得病毒外壳蛋白亚基分子量为35,500。     

侵染半夏的两种病毒的分离纯化和初步鉴定

用自然感染的半夏（Ｐｉｎｅｌｌｉａｔｅｒｎａｔａ）为材料,经粗提纯后检查到一种线状病毒和一种球状病毒,用两种方法对担提纯样品中的病毒粒子进行了分离纯化。１０％－７０％连续甘油梯度８００００ｇ离心１５０分钟获得两条病毒带,经紫外吸收测定均为强的核蛋白吸收峰,病毒粒子检查分别为球状和线状病毒粒子,线状病毒经浓缩收集为均一成份．与芋花叶病毒（Ｄａｓｈｅｅｍｍｏｓａｉｃｖｉｒｕｓ,ＤＭＶ）抗体有强的阳性反应。粗提纯样品经０．８％琼脂糖凝胶电脉分离为一条蛋白带,该条带回收后经紫外吸收测定为核蛋白吸收峰,电镜下检查为均一的球状病毒,以ＴＭＶ为对照、醋酸铀（ＵＡＣ）负染后测得该球状病毒（ｐｉｎｅｌｌｉａｓｐｈｅｒｉｃａｌｖｉｒｕｓ１．ＰｓＶ－１）的大小为３１．７ｎｍ;戊二醛固定后磷钨酸（ＰＴＡ）负染测得ＰｓＶ—１的大小为３４．０ｎｍ。各组分经ＳＤＳ－聚丙烯酸胺凝焦电泳分析测得线状病毒和球状病毒的外壳蛋白分子量分别为２０ＫＤ和２８ＫＤ。初步确定线状病毒为ＤＭＶ．球状病毒ＰｓＶ—１为侵梁天南星科半夏的一种新病毒。     

黄地老虎颗粒体病毒的研究II. 包含体和病毒粒子的分离提纯与形态结构

本文介绍了AsGV-XJ包含体、病毒粒子的提纯方法及其形态结构。提纯的AsGV-XJ包含体在弱碱(0.05M Na2CO3,0.05M NaCl,pH10．8)中,20℃水解2小时,释放出完整的病毒粒子,再经超离心和10—70％蔗糖密度梯度离心可得提纯的病毒。完整的病毒粒子具有双层膜结构,平均大小为310×70nm,核衣壳平均大小为325×45nm。病毒沉降系数为1,400S。并对病毒的紫外吸收特性和保存过程中的形态变化进行了讨论。     

苜蓿花叶病毒提纯方法的改进*

用来自于白车根草（Trifolium repens）上的一个苜蓿花叶病毒分离物AMV－SY为材料,比较了3种以差速离心为主结合PEG沉淀和超速离心提纯病毒的方法,对提纯病毒进行紫外吸收测定、电镜检查和SDS－聚丙烯酰胺凝胶电泳检测的结果显示：以交替使用含有0.1mol/LEDTA和0.1mol/L MgSO4的磷酸缓冲液作为病毒悬浮介质的提纯程度最为理想,该方法提取苜蓿花叶病毒的得率为47.6mg/100g昆诺藜鲜病叶,该病毒分离物的外壳蛋白分子量为29kD。该方法的病毒得率较高、杂蛋白较少、病毒粒子完整,是比较理想的提纯方法。     

兔病毒性出血症(暂定名)的研究 Ⅱ.病毒的分离提纯、电镜观察及核酸性质

应用氯仿处理,聚乙二醇沉淀,差速及蔗糖梯度离心,可以获得部份提纯的兔病毒性出血症病毒制剂,制剂呈典型的病毒核蛋白紫外吸收曲线,最高吸收值在260nm,A260/280=1.3,电镜下病毒呈廿面体,大小约36nm,无外膜,用该制剂回接健康兔,能引起典型发病及死亡,用核糖核酸及脱氧核糖核酸酶处理,证明病毒核酸为DNA,病毒DNA的温度熔解曲线测定证明,DNA为双链,初步测定DNA的分子量约为13-15×10~(?)道尔顿。     

草莓伪温和黄边病毒提纯技术的研究

纯化的草莓伪温和黄边病毒(SPMYEV),小叶嫁接繁殖于指示植物草莓UC—4上,然后采样榨汁,结合聚乙二醇(PEG)沉淀,蔗糖垫底差速离心及连续性蔗糖密度梯度离心,能成功地将草莓伪温和黄边病毒提纯出来。经电镜观察为丝杆状病毒粒体,长×宽为650nm×12—13nm。提纯的病毒制剂,经紫外分光光度计测定,呈典型的核蛋白吸收曲线,其最大值位于263nm,最小值位于243nm。A260/A280=1.24,用冰醋酸分解病毒,提取衣壳蛋白,经SDS-聚丙烯酰胺凝胶电泳测定其分子量约37000道尔顿。     

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.