SARS冠状病毒的起源研究进展*

SARS冠状病毒(SARS—CoV)是一种新现病毒,可感染多种动物,果子狸是人类SARS—CoV重要的动物宿主之一,是已知较理想的实验动物模型。遗传因素在SARS-CoV的出现过程中起重要作用,它很可能是哺乳动物和鸟类冠状病毒之间重组产生的新物种,但发生基因重组不是SARS在人群中暴发的原因。     

马抗SARS-CoV免疫球蛋白制备的研究

用纯化灭活的SARS—CoV抗原免疫马匹,采集血浆加入S／D灭活／去除病毒,用硫酸铵盐析沉淀提取抗SARS—CoV IgG,再经胃酶切、柱超滤等工艺制备马抗SARS-CoV免疫球蛋白。研制的马抗SARS—CoV免疫球蛋白制品中和抗体效价达1：6400以上、F(ab’）2纯度在90％以上。建立了高效、稳定、效果好的马抗SARS—CoV免疫球蛋白生产工艺,为SARS的治疗和预防提供了可靠的保证,也为传统抗血清的更新换代提供了技术平台。     

SARS-CoV S蛋白基因的克隆及其与VSV-G融合表达载体的构建

为了解重症急性呼吸综合征冠状病毒(SARS—CoV)表面S蛋白的受体结合功能域及其在宿主细胞上的作用受体,应用PCR技术从SARS—CoV cDNA中克隆到S蛋白的全长基因,并构建了S蛋白与疱疹性口腔炎病毒胞膜蛋白(VSV—G)融合表达载体pVSV—G‘-SG,进而为制备含有SARS—CoVS蛋白膜外区的逆转录病毒假毒粒奠定了实验基础。     

SARS冠状病毒的Spike蛋白以及病毒的细胞侵入机制

严重急性呼吸系统综合征（SARS）是由SARS冠状病毒（SARS—CoV）引起的一种新型人类疾病,具有高致病性、高传染性、高死亡率的特点。Spike蛋白是冠状捅毒膜表面的糖蛋白突出,构成病毒的包膜子粒,在病毒与其受体结合、通过膜融合进入宿主细胞以及诱导机体产生中和性抗体的过程中发挥着重要的作用：目前利用Spike蛋白开发出的一些防治SARS的药物和疫苗在动物和体外实验中有良好的抗病毒作用。本文阐述了SARS—CoV Spike蛋白的结构与功能,为抗SARS药物及疫苗的研发提供一定的理论基础.     

严重急性呼吸综合征(SARS)冠状病毒S蛋白的鉴定与分析

利用293细胞对SARS病人样品进行病毒扩增,培养上清中病毒颗粒经过纯化后,利用蛋白质组学技术,对纯化得到的SARS冠状病毒颗粒蛋白进行初步分离与鉴定。其中质谱分析结果最终表明,分子量约150kD的蛋白质的氨基酸序列与SARS—CoV基因组所预测S蛋白质序列高度吻合,从而首次从蛋白质水平对SARS冠状病毒S蛋白的氨基酸序列进行了证实。     

特异性鸡卵黄免疫球蛋白（IgY）抗SARS-CoV作用的研究

制备了抗SARS CoVIgY ,探讨了该IgY中和SARS CoV的作用。灭活的SARS CoV免疫产蛋母鸡 ,水稀释法提取IgY。建立ELISA检测IgY结合SARS CoV的效价 ,采用病毒中和试验测定IgY的抗SARS CoV的作用。灭活SARS CoV免疫的母鸡可产生高效价的抗SARS CoVIgY ,该IgY中和SARS CoV的中和效价为 1∶5 12。因此 ,抗SARS CoVIgY可用于预防SARS CoV的感染及阻止SARS病毒的传播。     

SARS病毒基因组的多态性

对SARS病人粪便样本直接测序,得到SRAS—CoV BJ202全基因组序列（AY864806）。应用比较基因组研究方法对GenBank中公布的115株SARS—CoV基因组序列以及BJ202进行分析。以GZ02序列为参照,发现2个以上基因组中同时存在单核苷酸多态（SNP）位点共278个。多态位点在SARS—CoV基因组中呈偏态分布,大约一半突变位点（50．4％,140／278）发生在基因组3’末端1／3区域。编码Orf10-11、Orf3／4、E蛋白、M蛋白和S蛋白区域突变率较高。克隆并测序含有BJ202基因组12个多态位点的11个cDNA以及4个不含已知多态位点的cDNA片段（15个片段总长度为6．0kb）,结果显示：BJ202特有的3个多态位点（13804、1503l和20792）以及另外3个多态位点（26428、26477和27243）均检出两种不同核苷酸;位点18379虽在已公布的115株SARS—CoV基因组中未发现突变,实际上也是多态位点。14个克隆中有8个克隆该位点为A,6个克隆为G。全部116个SARS—CoV基因组中共有18种缺失类型和2种插入类型。大部分缺失发生在编码ORF9和ORF10-11区域（基因组序列27700—28000bp处）。以邻位连接法（Neighbor-Joining）构建了116株SARS—CoV系统发育树,BJ202与BJ01和LLJ-2004等SARS—CoV的亲缘关系较接近。     

肿瘤患者血清中SARS-CoV抗体阳性原因分析

探讨SARS冠状病毒(SARS—CoV)抗体在SARS病原学诊断中的特异性及其在肿瘤患血清中的假阳性问题。应用ELISA和荧光定量RT-PCR技术检测了111例正常对照和40例肿瘤患血清中SARS—CoV抗体的阳性率。在111例正常对照中,IgM抗体均阴性,IgG抗体的阳性率为3．6％(4／111);IgG抗体诊断SARS的特异性为96．4％,两种抗体同时阳性诊断SARS的特异性为100％。40例肿瘤患中,IgM抗体均阴性,IgG抗体阳性率17．5％(7／40)。经RT—PCR检测,上述肿瘤患阳性病例均为阴性。结果表明,同时测定SARS—CoV的两种抗体可降低诊断的假阳性率,提高诊断的特异性。用非纯化SARS—CoV抗原制备的ELISA试剂盒测定肿瘤患的SARS—CoV抗体,可能出现假阳性。在肿瘤患中出现假阳性的原因可能与包被的抗原有关。     

天然白细胞干扰素制品中亚型成份的研究

<正>cDNA研究证实自然界中存在的人α干扰素(IFN—α)有二十多个亚型。有几个亚型的cDNA已被分离,其中有的植入大肠杆菌以制备临床级重组IFN—α。从Namalwa细胞获得的IFN—α也进行了研究,并作为淋巴母瘤细胞的“天然干扰素”应用于临床。用仙台病毒刺激正常白细胞获得的天然IFN—α的几个亚型已纯化和分析。然而各亚型的特性和生物学功能尚不清楚。很有必要研究这些亚型在宿主防御机制中是否有除抗病毒活性外的特殊     

抗SARS药物设计的靶点--冠状病毒主蛋白酶

严重急性呼吸综合征(severe acute respiratory syndrome，SARS)由SARS冠状病毒(SARS—CoV)感染所引起。SARS—CoV主蛋白酶(M^pro)在冠状病毒复制及转录过程中起重要作用，因而成为直接抗SARS病毒药物设计的一个颇为诱人的靶标。SARS—CoVM^pro的三维结构的阐明、酶与抑制剂间结合方式的确认，为发现直接作用于M^pro的抗SARS药物设计提供了基础。     

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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV