棉铃虫单粒包埋型核型多角体病毒复制的研究：Ⅰ.细胞病理学和病毒…

本文报道了棉铃虫单粒包埋型核型多角体病毒在棉铃虫及棉铃虫蛹卵巢细胞系ＳＦＥ－ＨＡ－８２１２中的复制。ＨａＳＮＰＶ的复制和其他的核型多角体病毒大体相符,复制过程也可分为形成出芽型病毒与形成包埋型病毒这两个时相。研究了影响病毒在细胞中复制的诸因素,包括毒感染复数、细胞生长阶段等。在适宜的条件下平均每细胞可生产出芽型病毒１４ＰＦＵ,多角体２４个,生成的病毒具有感染力。这些表明ＳＦＥ－ＨＡ－８２１２细胞可     

中国本溪虹鳟一株弹状病毒的分离及初步研究

１９９０年４月,辽宁省本溪市虹鳟鱼种场的虹鳟稚鱼爆发大规模疾病,死亡率近１００％。取病鱼组织处理后接种于鱼类细胞,出现明显的细胞病变,测定细胞培养物中的病毒滴度,最高达１０￣（６．３）ＴＣＩＤ＿（５０／０．１ｍｌ）。感染病毒的细胞用１％营养琼脂糖覆盖后可形成０．５－１．５ｍｍ的蚀斑。分离到的病毒对氯仿敏感,不耐热、不耐酸,在细胞内复制的最适温度为１５℃。室内人工感染的虹鳟稚鱼能复制出与天然发病相同的症状。对感染病毒的细胞制成超薄切片,透射电镜观察,病毒长为１３１－１７３ｎｍ,平均１４８ｎｍ,直径为５８－９１ｎｍ,平均７１ｎｍ,形状为子弹状,表明是弹状病毒,有囊膜及纤突。采用挑斑法得到了纯化的病毒株,暂称之为传染性造血器官坏死症病毒中国本溪株ＩＨＮＶ－Ｂ。     

树Qu类—细小病毒的初步研究

从树Ｑｕ肾细胞培养物中分离出３株病毒,嗜在对数分裂期的ＴＬ细胞上复制,产生细胞病变和血凝素抗原,能凝集豚鼠和小鼠红细胞。交互血凝抑制实验表明３株病毒同属一个血清型。免疫酶染色显示抗原首先出现于细胞株,电镜观察负染标本病毒形态近似圆形和六角形,无胞膜,直径约３０ｎｍ。血清学检查大多数树Ｑｕ血清中含有该病毒抗体,证明是树Ｑｕ的一种潜在病毒。初步鉴定为类－细小病毒。     

044细胞病毒学

病毒感染细胞才能复制，其复制周期每一步都需利用大量细胞功能，如病毒利用宿主膜获得脂质外膜，DNA病毒（除痘病毒）复制需要利用细胞核酸。     

我国新分离虫媒病毒的初步鉴定

1990－1994年,从新疆地区的蚊、蜱和病人血清分离了多株病毒,为了明确这些病毒的分类地位,对其中的20株病毒进行了组织培养细胞感染实验和血清学检验,对部分毒株做了动物接种实验和理化性质鉴定。结果显示：20株病毒均可使BHK－21细胞病变（1－3天）,主要表现为细胞圆宿、聚集,融合,破碎,脱落等;致Vero细胞病变为2－4天;15株病毒致C6／36细胞病变（2－4天）,5株病毒对C6／36细胞连续观察7天未见细胞病变。11株病毒对乳鼠2－4天致死,对成年鼠2－5天致死。选取6株病毒进行理化性质鉴定,4株病毒（90260、91002、91004和91028）对5－氟脱氧尿苷耐受,对乙醚和酸敏感,提示为有膜RNA病毒;一株病毒（90265）对5－氟脱氧尿苷、乙醚和酸均敏感,提示为有膜DNA病毒;另一株病毒（9059）对5－氟脱氧尿苷耐受,对乙醚和酸也耐受,提示可能为无膜RNA肠道病毒。20株病毒中,17株病毒与甲病毒、乙型脑炎病毒和布尼亚病毒的特异性免疫腹水不反应,提示这些病毒中可能不存在甲病毒、黄病毒和布尼亚病毒;3株病毒（90260、91002和91004）只与甲病毒的特异性免疫腹水反应,与乙型脑炎病毒和布尼亚病毒的不反应,提示这三株病毒为甲病毒。     

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     

A型流感病毒持续感染细胞系来源的IVpi-189病毒生物学性状的初步研究

为明确E61-24-P15 A型重组流感病毒的第189代传代子病毒(IVpi-189)是否具备流感病毒温度敏感减毒活疫苗候选株的特点,将IVpi-189病毒感染MDCK细胞,并于不同培养温度条件下培养,观察其致细胞病变效应,病毒合成、释放情况,以及不同温度条件下病毒存活时间。结果显示32℃培养温度下,IVpi-189病毒具有等同于亲代野生病毒株的诱导细胞病变能力,而当培养温度上调至38℃,IVpi-189病毒致细胞病变效果出现缓慢且程度明显减轻。空斑形成单位实验发现IVpi-189病毒在38℃培养条件下增殖能力明显下降,其原因与病毒灭活速度及子病毒释放无关,但与感染细胞病毒合成能力下降有关。上述实验结果初步证实流感病毒持续感染细胞系来源的IVpi-189病毒具有温度敏感减毒活疫苗的生物学特性,在许可培养温度条件下具有良好的增殖能力,而在非许可培养温度下,病毒增殖活性受到明显抑制。本研究为流感病毒减毒活疫苗的开发研制提供实验佐证。     

草鱼出血病病毒的生长特性及高滴价培养

草鱼出血病病毒感染鱼肾(Clk)单层细胞后,产生明显的细胞病变,其繁殖周期为2—3天。病毒增殖的上升期在感染后的12—48小时。28℃下,当感染复数(Multiplicityof Infection简称MOI)为0.05PFU/cell时,病毒滴价可达1.78×10~(11)PFU/ml,不同温度(25℃、28℃、30℃)下通气培养,测定病毒滴价略有差异。感染病毒的细胞培养液经ELISA检测和电子显微镜观察均为阳性结果,并且能感染健康草鱼。     

宿主细胞骨架与内膜网络重构调控病毒复制

病毒性疾病的日益频繁暴发严重危害全球人类健康和经济发展.病毒感染的一个共同特征是重塑宿主细胞的膜结构和细胞骨架结构,形成用于病毒基因组复制的特化亚细胞结构,称为病毒工厂.不同的病毒可能会挟持不同的宿主细胞器进行膜修饰形成形态各异的复制工厂,包括病毒质体、小球体、双膜囊泡、管状体和细胞核病毒工厂.三种细胞骨架微丝、微管、中间丝形态在病毒复制过程中也会发生剧烈重塑,形成笼状结构包裹病毒工厂,包括肌动蛋白环、微管笼和中间丝笼.本文系统描述了病毒复制阶段病毒工厂的形成过程及细胞骨架组分和膜组分的形态学变化,重点阐述了三种细胞骨架及其相关蛋白在病毒工厂建立过程中的物质运输、物理支撑、和生化调控功能,简要介绍了相关研究技术手段,并讨论了病毒感染背景下病毒组分-细胞内膜-细胞骨架三者相互作用的重要性和未来研究方向.     

鹅源鸭瘟病毒和小鹅瘟病毒在同一宿主系统增殖的观察

本文首次报道了鹅源鸭瘟病毒(DPV—Ⅰ)和鸭胚化小鹅瘟病毒(GPV—Ⅰ)能同时在同一鸭胚内复制增殖,未发现干扰作用,在理论上说明某些不相关的两种病毒可在同一宿主增殖,实践上为利用同一鸭胚研制二联疫苗提供了依据。研究结果表明:1.DPV—Ⅰ和GPV—Ⅰ联合感染同一鸭胚后,其尿囊液在电镜下见两种病毒,DPV—Ⅰ呈园形或椭园形,有囊膜,直径为38—109nm,GPV-Ⅰ呈园形,无囊膜,直径为18—25nm;2.含毒尿囊液使鸭胚成纤维细胞(DEF)单层发生细胞病变作用(CPE),证实存在DPV-Ⅰ,而用小鹅瘟微量免疫扩散(MID)试验,又能检出GPV-Ⅰ抗原;3.含毒尿囊液免疫鹅的血清中存在抗两种病毒的(?)和抗体和GPV沉淀抗体;4.含毒尿囊液免疫的成鹅对DPV强毒攻击有相当免疫力,免疫鹅血清能中和GPV,使其失去对鸭胚的致病力;5.GPV-Ⅰ单独或与DPV-Ⅰ联合感染DEF单层后,均未见在细胞上复制。     

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.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.