SARS病毒NS-1株稳定性及培养条件的研究

用SARS病毒NS-1株接种Vero细胞,37℃培养,于培养1、2、3、4d收获病毒液,分别置-70℃冻融和4℃释放,于不同时期取样进行病毒滴定。结果显示,SARS病毒NS-1株各代次培养特性和形态学变化完全相同,有较好的抗原特异性,病毒滴度稳定,4℃保存125d,滴度下降2．25lgCCID50／ml,-70℃保存6个月,滴度未见明显下降。SARS病毒NS-1株未经冻融或释放,1d收获的病毒滴度比2、3、4d收获的病毒滴度低,经冻融或释放,1、2、3、4d收获的病毒滴度无明显区别,病毒收获时的病毒滴度与形态学变化成正相关。不同接种条件收获的病毒液,病毒滴度无明显区别。SARS NS-1株有较好的遗传稳定性和保存稳定性,培养2d,4℃释放收获病毒液,细胞悬液与病毒混合接种更简单,易操作,更适合疫苗规模生产。     

同批次细胞基质收获甲肝和麻疹病毒制备联合疫苗的方法

采用同一批次细胞基质收获甲肝和麻疹病毒.应用甲肝L-A-1株和麻疹D3T11株,间隔3周先后感染同一批次人胚肺二倍体细胞2BS株,待两种病毒同时达到增殖高峰期时收获病毒液(以下简称HAM).对HAM分别进行病毒滴定、特异性检查、猴体安全性和免疫效果试验.结果显示,HAM的甲肝和麻疹病毒滴度与同批单价甲肝和麻疹疫苗病毒滴度,差异均无显著意义.该方法用于制备甲肝-麻疹联合疫苗,省时省力,操作简便,并可显著降低疫苗生产成本.     

狂犬病病毒Vero细胞适应株的建立及其应用于疫苗生产的可行性探讨

将狂犬病病毒７ａＧ固定毒适应于Ｖｅｒｏ细胞,建立了稳定的ＶＲＧ适应株。病毒滴度可达７．６９ｌｏｇＬＤ５０／ｍｌ,病毒最适增殖时间５—７天,最适种毒比例１：１０￣３。应用转瓶培养Ｖｅｒｏ细胞增殖病毒,收获病毒液经β—丙内脂灭活,超离浓缩制备疫苗,效力试验结果（ＮＩＨ法）较原制疫苗成倍增高,且都大于２．５ＩＵ／２ｍｌ,表明ＶＲＧ适应株可应用于制备Ｖｅｒｏ细胞狂犬病疫苗。     

呼吸道合胞病毒Long株的培养及应用

建立可稳定收获高滴度RSVLong株病毒的培养方法 ,所获得的RSVLong株病毒液用于RSV抗体ELISA检测。RSVLong株病毒 33℃传至 4代后 ,病毒滴度升高 ,出现典型的细胞病变。以RSVLong株病毒液作抗原所建立的ELISA试剂盒能检测出RSV特异性抗体。     

病毒感染复数对狂犬病毒PM株增殖的影响

目的探讨不同感染复数(Multiplicity of infection,MOI)的狂犬病毒PM株在人二倍体细胞(2BS株)中增殖的影响,确定感染复数。方法将狂犬病毒PM株按照MOI 0.01、0.02、0.05、0.10、0.15、0.20接种至2BS细胞中,用显微镜观察接种病毒后细胞的形态变化;培养3~5 d后,第一次收获病毒液;更换培养液继续培养3~4 d后,进行第二次收获。采用小鼠脑内滴定法测定狂犬病毒滴度,通过NIH法测定灭活病毒液的效价。结果当MOI为0.05~0.10时,细胞圆缩30%~40%,细胞能维持较好的生长形态,可收获病毒,病毒收获液的滴度较高(5.0lg LD50/m L),且灭活后病毒液的效价较高(4.0IU/m L)。结论确定狂犬病毒PM株在人二倍体2BS细胞增殖的适宜MOI,为人用狂犬病疫苗生产工艺的优化提供了依据。     

生物反应器培养轮状病毒基因重配株Ls条件的优化

目的轮状病毒基因重配株Ls(G3型)在生物反应器微载体培养Vero细胞条件的优化。方法采用3 L生物反应器微载体培养Vero细胞,观察Ls株在不同病毒感染复数(0.001、0.002、0.010、0.040 MOI)、不同温度(34.5℃和35.5℃)、不同病毒收获时间(24和48 h)对病毒增殖的影响。根据病毒滴度和收获量筛选出最适MOI、培养温度及病毒的收获时间。结果以0.002 MOI接种Vero细胞,温度为34.5℃培养病毒,滴度最高达7.50 lg CCID50/m L;48 h可连续收获4次病毒液,且收获总量及病毒滴度均高于24 h。结论通过对Ls株在生物反应器微载体Vero细胞培养条件的优化,获得的病毒液滴度高及连续培养多次收获量增加的有效方法,为进一步规模化培养奠定了基础。     

森林脑炎病毒疫苗株的全基因组序列分析

实验设计针对森林脑炎病毒的特异性引物,以被森林脑炎疫苗株病毒感染的鼠脑组织中提取的总RNA为模板,用PCR方法分段逆转录合成、扩增序列并测序,应用DNASTAR软件比较分析。结果表明,该病毒疫苗株的全基因组由10782个核苷酸组成,编码3414个氨基酸。森林脑炎疫苗株病毒全基因序列的测定,为研究该病毒疫苗株的生物学特性提供了分子基础。     

森林脑炎疫苗的研究进展

森林脑炎是严重危害人类健康的中枢神经系统急性病毒性传染病,在欧洲森林脑炎为一种地方病也是最重要的由节肢动物传播的病毒性传染病,成为主要的公共卫生问题。森林脑炎在我国存在有三大疫区、六个自然疫源地,其中东北疫区最为严重。森林脑炎为我国法定的由生物因素引起的职业病之一。美国CDC将森林脑炎病毒列为C类病毒类生物武器,并优先发展疫苗。预防森林脑炎病毒感染和流行以及抵御病毒类生物武器的袭击最有效的方法就是接种森林脑炎疫苗,森林脑炎疫苗在预防森林脑炎发病过程中发挥着重要作用,本文将森林脑炎疫苗研究现状和疫苗的免疫预防效果作以概述。     

应用生物反应器建立人用冻干狂犬病疫苗(Vero细胞)生产工艺的研究

应用15L生物反应器,采用片状载体对Vero细胞进行高密度培养、制备高毒力滴度的狂犬病毒收获液,经纯化后生产人用冻干狂犬病疫苗。采用15L生物反应器对培养方法(批次培养和连续灌流培养)进行试验,收获高毒力滴度的狂犬病毒收获液并制备人用冻干狂犬病疫苗。结果表明:Vero细胞在接种狂犬病毒后可以连续收获病毒液达到25d以上,冻干狂犬病疫苗的效价可以达到5.54IU/剂。本工艺可以用于进行大规模的人用冻干狂犬疫苗的生产。     

麻疹疫苗生产用毒株沪191增殖的动力学研究

通过延长麻疹病毒生产中感染的基质细胞培养时间并连续收获病毒,获得麻疹病毒生产的动力学曲线;通过工艺放大阶段的病毒增殖动力学研究,提高麻疹病毒产量。采用直接接种和间接接种法,接种不同感染量(MOI)的病毒,将转瓶培养单次收获改为转瓶培养多次收获,滴定整个培养期间每次收获液的病毒滴度,观察感染的细胞培养维持状况并计算病毒产量。结果表明,直接接种病毒培养期为20~25d,共收获病毒14~17次;间接接种病毒培养期24d,共收获病毒29次。通过延长感染细胞培养时间和连续收获病毒,获得病毒繁殖的动力学曲线。通过麻疹毒株的增殖动力学研究获得了麻疹疫苗生产毒株沪191增殖动力学相关参数。     

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.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

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.