养殖贻贝中观察到一种球形病毒

用电镜负染方法在发病的贻贝内脏团、鳃、外套膜组织匀浆中观察到一种球形病毒粒子,其直径为80-200nm,具囊膜。上述组织超薄切片发现在其结缔组织细胞质中均存在该病毒粒子,带双层囊膜,有“封入体”结构,未见包涵体。在未发病的杂色蛤、香螺、牡蛎等内脏团中也观察到少量同种病毒粒子。用带病毒贻贝组织匀浆投喂和划伤感染不带病毒的绣凹螺,使之成为带病毒状态。采用蔗糖梯度离心法,25000r／min,离心3h,可于20％-30％蔗糖层间获得病毒沉淀带。     

皱纹盘鲍一种球形病毒的感染及其发生

在发病的皱纹盘鲍（HaliotisdiscushannaiIno）幼鲍的足、内脏团、外套膜的血细胞质内,发现一种直径为90～140um的球形病毒粒子,带双层囊膜,无包涵体。负染病毒粒子与超薄切片大小形态相同。用被病毒感染的患病幼鲍感染健康鲍获同样症状,死亡率为50％。并于人工感染死亡鲍鱼体内观察到同样病毒。     

鳜鱼病毒病原及细胞感染特性的研究

在患暴发流行性发病鳜鱼的脾、肾、肝、鳃组织细胞的超薄切片中观察到直径为120-150 nm的二十面体病毒粒子,其截面呈六角形,有囊膜.将病鱼内脏与10倍体积的PBS缓冲液制成组织匀浆液,过滤除菌后感染对数生长期的草鱼肾细胞.结果表明,该感染液在28 ℃条件下,培养36-48 h,生长旺盛的草鱼肾细胞开始出现CPE,5-7 d感染的单层细胞逐渐脱落死亡.该细胞病毒悬液具有感染性,可持续稳定地进行传代培养.感染细胞的病毒培养液,经差异离心纯化,负染制片,电镜下观察到大量的病毒粒子,对照培养物中未发现任何病毒颗粒.     

福州地区对虾白斑病病毒的超微结构

在福州地区分离到一种高致病性的白斑病病毒,该病毒仅存在于细胞质中,完整的病毒粒子有囊膜,一端略圆,一端稍尖,直径约为80～100 nm,囊膜与核衣壳之间的间隙约为20～25 nm.该病毒在细胞内不形成包含体,但有些可形成封入体.负染观察到的病毒核衣壳呈直杆状,但长度和直径相差较大,最长的病毒超过600 nm.这些特征与其它已报道的白斑病病毒有所不同,因此暂将它称为"对虾白斑病病毒福州分离株".     

棉铃虫核多角体病毒在中肠及其它组织中增殖过程的电镜观察

应用电子显微镜技术观察了核多角体病毒在棉铃虫体内的增殖方式。在中肠细胞内增殖的核衣壳极少被囊膜包围,也很少形成多角体。它们能大量地释放到体腔,迅速感染其他敏感组织。在其他敏感组织内增殖的核衣壳大部分被囊膜包围形成病毒粒子,且随机包涵在多角体中形成核多角体。     

棉铃虫核多角体病毒在中肠及其它组织中增殖过程的电镜观察

应用电子显微镜技术观察了多核角体病毒在棉铃虫体内的增殖方式,在中肠细胞内增殖的核衣极少被囊膜包围,也很少形成多角体。它们能大量地释放到体腔,迅速感染其他敏感组织,在其他敏感组织内增殖的核壳大部分被囊膜包围形成病毒粒子,且随机包涵体多角体中形成核多角体。     

福州地区对虾白斑病病毒的超微结构

在福州地区分离到一种高致病性的白斑病病毒 ,该病毒仅存在于细胞质中 ,完整的病毒粒子有囊膜 ,一端略圆 ,一端稍尖 ,直径约为 80～ 10 0nm ,囊膜与核衣壳之间的间隙约为 2 0～ 2 5nm。该病毒在细胞内不形成包含体 ,但有些可形成封入体。负染观察到的病毒核衣壳呈直杆状 ,但长度和直径相差较大 ,最长的病毒超过 6 0 0nm。这些特征与其它已报道的白斑病病毒有所不同 ,因此暂将它称为“对虾白斑病病毒福州分离株”。     

老虎感染猫传染性鼻—结膜炎病毒的研究

用猫肾传代细胞从发病虎的病料中分到了一株杯状病毒粒子样病毒。该病毒大小为３５～３９ｎｍ、无囊膜、在胞浆中病毒前体呈晶格状排列,抗乙醚、不能被５－ＩＵＤＲ所抑制,能被来源于标准疫苗的猫传染性鼻－结膜炎病毒（或杯状病毒Ｆｅｌｉｎｅ ｃａｌｉｃｉｖｉｒｕｓ,ＦＣＶ）抗血清所中和,人工感染猫出现典型的ＦＣＶ感染症状。ＲＴ－ＰＣＲ能扩增出与设计值相符的电泳带,ＰＣＲ产物直接测序结果与Ｇｅｎｅｂａｎｋ发表的Ｆ     

鳜鱼病毒病原及细胞感染特性的研究

在患暴发流行性发病鳜鱼的脾、肾、肝、鳃组织细胞的超薄切片中观察直径为１２０－１５０ｎｍ的二十面体病毒粒子,其截面呈六角形,有囊膜。将病鱼内脏及１０倍体积的ＰＢＳ缓冲液制成组织匀浆液,过滤除菌后感染对数生长期的草鱼肾细胞。结果表明,该感染液在２８℃条件下,培养３６－４８ｈ,生长旺盛的草鱼肾细胞开始出现ＣＰＥ,５－７ｄ感染的单层细胞逐渐脱落死亡。该细胞病毒悬液具有感染性,可持续稳定地进行传代培养。感染     

苜蓿丫纹夜蛾核型多角体病毒囊膜内核衣壳排列图式的电镜观察

核型多角体病毒有单核衣壳包埋型和多核衣壳包埋型之分,单核衣壳包埋型是在一个病毒囊膜内只包含一个核衣壳,而多核衣壳包埋型的特点是在一个病毒囊膜内包含有２个以上的核衣壳,由于多个核衣壳成束地被包装在同一个病毒囊膜内,又称病毒束［１,２］。Ｈｕｎｔｅｒ等表明在干果斑螟核型多角体病毒中,病毒囊膜内包含２～２３个核衣壳［３］。Ｆｒａｓｅｒ将苜蓿丫纹夜蛾核型多角体病毒接种于秋粘虫细胞系,超薄切片电镜观察,病毒囊膜内包含的核衣壳数变动于２～１７粒,但未研究其核衣壳在病毒囊膜内的排列结构［４］。本研究用苜蓿丫纹…     

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.