Ⅲ型中国株HCVE2/NS1基因与已知分离株的同源性比较

利用逆转录套式ＰＣＲ扩增Ⅲ型中国株ＨＣＶＥ２／ＮＳ１基因片段,将其克隆到ｐｃＤＮＡ３载体上．采用双脱氧链终止法测定插入片段的核苷酸序列．并与已知分离株的相应区域进行同源性比较．首次克隆出Ⅲ型中国株ＨＣＶＥ２／ＮＳ１基因（ＨＣ－Ｗ１４）,其核苷酸序列与Ⅲ型日本株ＨＣＶ（ＨＣ－Ｊ６）该区域同源性为８８．３７％,其推定的氨基酸同源性为８９．２９％．而与已知的非Ⅲ型株ＨＣＶ该区域相比,核苷酸及氨基酸的同源性均相对较低．Ⅲ型中国株ＨＣＶ与Ⅱ型中国株ＨＣＶ在Ｅ２／ＮＳ１区域有较大的变异,揭示研制我国的ＨＣＶ疫苗应该考虑这种基因型之间的变异性．     

戊型肝炎病毒中国XT—179株全基因组Cdna克隆及其核苷酸和氨基酸序列分析

本文报道对中国新疆东部一起戊型肝炎流行高峰期间,由ＨＥ患者烘便中分离到的型肝炎病毒中国ＸＴ－１７９株进行全基因ｃＤＮＡ克隆、核苷酸和氨基酸序列测定及分析结果。所阐明的ＨＥＶ－ＸＴ－１７９株基因组全序列由７１９４个核苷酸和３＇端的多聚腺嘌呤核苷酸尾组成。四种核苷酸的含量腺嘌呤（Ａ）为１７．０％,胞嘧啶（Ｃ）为３１．９％,鸟嘌呤（Ｇ）为２６．０,尿嘧啶（Ｕ）为２５．１％。Ｇ＋Ｃ含量为５７．９％。全基因     

番茄花叶病毒外壳蛋白基因及3′端非编码区的克隆、序列分析及其表达

根据已报道的番茄花叶病毒Ｌ株系（ＴｏＭＶＬ）序列人工合成引物,经ＲＴＰＣＲ扩增并克隆了我国番茄花叶病毒分离物（ＴｏＭＶＳ１）的外壳蛋白ＣＰ基因及３′端非编码区。序列测定结果表明,所得ｃＤＮＡ共长６８２个核苷酸,其中ＣＰ基因含４８０个核苷酸,编码１５８个氨基酸,３′端非编码区含２０２个核苷酸,其核苷酸序列与ＴｏＭＶＬ株系具有９９．５％的同源率。将该基因片段克隆到ｐＧＥＭＥＸ１载体中,转入Ｅ．ｃｏｌｉ后诱导表达,经Ｗｅｓｔｅｒｎｂｌｏｔ检测证明,该基因已在大肠杆菌中正确表达。这是我国首次报道ＴｏＭＶＣＰ基因序列。     

中国不同地区和人群HDV cDNA的筛选、克隆及抗原编码区基因异质性的分析

为研究我国不同地区不同人群中ＨＤＶ毒株的感染分子特征,从我国河南、内蒙、北京、四川、广西、西藏、新疆、辽宁、上海等地的ＨＤＶ健康携带者、慢性丁肝病人与重症肝炎病人中筛选获得１０余份ＨＤＶ－ＲＮＡ阳性血清。经逆转录一多聚酶链反应（ＲＴ－ＰＣＲ）交叉扩增获得ＨＤＶ抗原编码区的ｃＤＮＡ片段并克隆到ＰＧＥＭ－３Ｚｆ（－）或ＰＧＥＭ－Ｔ载体上,经序列分析研究其基因结构特点,结果表明：中国的ＨＤＶ毒株基因型均为Ⅰ型,但至少存在ⅠＡ、ⅠＢ两个亚型,ＨＤＶ毒株在不同地区间存在异质性,其中河南－１、－２、－３株及新疆株与台湾株同源性较高（核苷酸与氨基酸同源性分别大于９２．１％与８６．９％）．当为ⅠＡ型;内蒙－１、四川、广西、西藏－１、辽宁、北京株与美国－１株同源性较高（核苷酸与氨酸同源性分别大于９４．３％与８８．８％）,当为ⅠＢ亚型;上海株与意大利株的核昔酸同源性最高,为９８．１％。研究证明我国新疆、内蒙、西藏等地区抗ＨＤ阳性率比其他省市高并不是由于存在其他基因型所致。     

HGV广东株和香港株NS5区部分基因的克隆及序列分析

采用ＨＧＶＮＳ５特异的２对引物,对两个香港株和一个广东株ＨＧＶＲＮＡ进行逆转录套式ＰＣＲ扩增,ＰＣＲ产物克隆入ｐＵＣ１９,重组质粒转化ＤＨ５α和ＪＭ１０９菌株。ＰＣＲ和酶切法鉴定阳性克隆,双脱氧链末端终止法测定核苷酸序列并进行同源性分析。结果发现核苷酸变异呈散在分布,三株间核苷酸和氨基酸序列同源性分别为９３．３％～９４％及９７％～９９．２％,与已报道的中国株（ＣＮ）相比,则同源性分别为９０％～９１．２％和９４％～９６．３％,与美国株（ＰＮＦ２１６１及Ｒ１０２９１）相比,为８７．１％～８９．５％和９５．２％～９７％,而与西非株（ＧＢＶＣ）相比,则达９１．４％～９３．８％和９７％～９７．９％。提示ＨＧＶＮＳ５区核苷酸和氨基酸序列相对保守,不同ＨＧＶ株存在一定的地区差异。     

我国丙型肝炎病毒囊膜蛋白E2高变区1的序列特征

对２３例国内献血员、血透析及肝炎病人血清用反转录巢式ＰＣＲ技术扩增了ＨＣＶＲＮＡ囊膜蛋白２基因的ｃＤＮＡ片段,并进行了序列测定。结果表明２３例病人ＨＣＶＥ２／ＮＳ１Ｎ末端的核苷酸及氨基酸序列呈现多样性,高变区１（ＨＶＲ１）位于核苷酸第１４５９～１５５９位,氨基酸第３８４～４１０位;我国ＨＣＶ株ＨＶＲ１２７个氨基酸中有１５个位置氨基酸相对稳定,氨基酸组成与分布均与Ｓｅｋｉｙａ报道的１６６个ＨＣＶ株的不同。结果提示,研究我国ＨＣＶ株ＨＶＲ１的序列特征有助于ＨＣＶ的流行病学研究,对研制适用于我国的抗体诊断试剂盒及进行疫苗研究均有重要的意义。     

抗原捕获聚合酶链式反应（AC－PCR）直接分型检测单纯疱疹病毒

用抗单纯疱疹病毒（ＨＳＶ）型共同性ｇＣ和ｇＤ羊克隆抗体（ＭｃＡｂ）,包被即Ｅｐｐｅｎｄｏｒｆ管,捕捉ＨＳＶ,同时加入３个引物：一个是ＨＳＶ─１／ＨＳＶ─２型共同性上游引物,另两个分别是ＨＳＶ─１和ＨＳＶ─２型特异性下游引物。借此建立了能直接分型检测ＨＳＶ的抗原捕获聚合酶链式反应（ＡＣ─ＰＣＲ）。ＨＳＶ─１的扩增产物为４７７ｂｐ,ＨＳＶ─２的为３９９ｂｐ两型病毒经ＡＣ─ＰＣＲ扩增后产生分子量不同的ＤＮＡ片段,致使ＡＣ─ＰＣＲ能直接分型检测ＨＳＶ。ＨＳＶ─１和ＨＳＶ─２扩增产物的克隆和序列分析表明,本方法特异性好。用本法检测Ｂａｌｂ／ｃ幼鼠中枢神经系统ＨＳＶ感染的脑标本,进一步证实本方法不仅敏感、特异,而且分型准确。     

病毒性肝炎HAV，HBV，HCV，HDV和HEV重叠感染的研究

采用ＥＬＩＳＡ法检测了１０８例乙型肝炎病毒（ＨＢＶ）感染者血清中的五种肝炎病毒──甲型（ＨＡＶ）、乙型（ＨＢＶ）、丙型（ＨＣＶ）、丁型（ＨＤＶ）和成型（ＨＥＶ）肝炎病毒的标志物,并采用ＰＣＲ技术检测了患者血清ＨＢＶＤＮＡ、ＨＣＶＲＮＡ及ＨＤＶＲＮＡ。结果五种肝炎病毒重叠感染者３５例（３２．４％）,单纯ＨＢＶ感染者７３例（６７．６％）。ＨＢＶ、ＨＡＶＭ重感染率为４．６％,ＨＢＶ、ＨＣＶ二重感染率为９．２％,ＨＢＶ、ＨＤＶＭ重感染率为１４．８％,ＨＢＶ、ＨＥＶ二重感染率为１．９％,ＨＢＶ、ＨＣＶ和ＨＤＶ三重感     

菠菜磷酸丙糖转移蛋白在烟草中正义及反义表达及其对碳水化合物转运的影响

以菠菜（Ｓｐｉｎａｃｉａ ｏｌｅｒａｃｅａ Ｌ．）为材料,取幼叶分离ｍＲＮＡ,反转录合成ｃＤＮＡ,以ｃＤＮＡ第一链为模板,通过ＰＣＲ扩增,获得菠菜磷酸丙糖转移蛋白（Ｔｒｉｏｓｅ ｐｈｏｓｐｈａｔｅ ｔｒａｎｓｌｏｃａｔｏｒ,ＴＰＴ）ｃＤＨＡ目的片段。对其进行序列分析,结果表明,分离的目的片段核苷酸序列与文献报道相比同源率为９９．９％,只不１个碱基发生改变。将得到的菠菜ｔｐｔ ｃＤＮＡ与ＣａＭＶ３５     

HCV非结构蛋白(NS2/NS3)基因表达载体的构建及其一级结构分析

应用逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）技术,从ＨＣＶ感染者血清中扩增编码ＨＣＶ病毒蛋白酶的ＮＳ２－ＮＳ３ｃＤＮＡ片段,在其５′和３′端分别引入ＥｃｏＲⅠ和ＸｂａⅠ限制性内切酶位点,定向克隆至真核表达载体ｐｃＤＮＡ３,构建重组载体ｐｃＤＮＡ－ＮＳ２３,重组表达载体经限制性内切酶消化鉴定．用ＳＰ６和Ｔ７通用引物对目的基因片断进行序列分析．序列同源性分析结果表明,与ＨＣＶ－Ｊ、ＨＣ－Ｃ２有高度的同源性,与ＨＣＶ－１、ＨＣＶ－Ｊ６、ＨＣＶ－Ｊ８同源性差,提示所克隆的基因属ＨＣＶⅡ型．该区内重要的功能位点如Ｚｎ２＋依赖性金属蛋白酶催化中心、丝氨酸蛋白酶催化中心等均高度保守     

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.