KPC-rg1抗H1N1流感病毒活性研究初探

为了研究肉桂提取物KPC-rg1对H1N1流感病毒的抗病毒活性.本研究以C57BL/6近交系小鼠为研究对象,并将小鼠分为3组,分别是健康空白组、对照组和实验组,分别对应给予磷酸缓冲盐(PBS)溶液、H1N1流感病毒溶液和H1N1流感病毒+KPC-rg1混合溶液,饲养28 d,观察实验过程中各组小鼠的存活率,通过红细胞凝集抑制实验(HI)分析KPC-rg1抗H1N1流感病毒的血凝抑制效价,并采用逆转录-聚合酶链反应(RT-PCR)方法定量检测病毒载量.与健康空白组相比,对照组小鼠接受H1N1病毒攻击后,体质量急剧下降,并在第3天出现死亡,而实验组小鼠给药后2 d内体质量略微下降,之后恢复到正常增长水平,且无小鼠死亡;小鼠感染28 d后,对照组和实验组小鼠血清中均检测出高滴度的血凝抑制效价(128 HAV);病毒攻击后3 d,对照组和实验组小鼠肺部病毒载量均达到1×10~7 copies/50 mg(1 IU≈5.6 copies);实验终点所有攻毒存活小鼠的肺组织病毒均得到了有效的清除.由此可知,KPC-rg1可有效地灭活H1N1流感病毒,对小鼠有显著的保护预防作用;被灭活的病毒保留了完整的抗原性,形成"原位固化灭活"效应;KPC-rg1可促使小鼠产生强烈的免疫应答反应,使机体产生高滴度的抗病毒抗体.     

乙型流感病毒在不同胚龄鸡胚中适宜孵育条件的研究

为了找出乙型流感病毒毒株在不同胚龄鸡胚中适宜孵育条件,提升血凝滴度,从而为产业化生产人用3价流感疫苗提高产能,主要采用血凝法检定收获尿囊液,分析试验血凝滴度数据,得出结论:乙型流感病毒毒株接种于10 d胚龄鸡胚,其孵育温度为35℃,孵育时间72 h最理想;孵育温度和时间对乙型流感病毒的血凝滴度有影响,同时鸡胚胚龄与其的血凝滴度和收获尿囊液量也有明显的关联。     

海洋活性物质C03抑菌及抗流感病毒的作用

活性物质CO3是从海洋分离出一种相对分子质量小于5000的抑菌肽，该物质对金黄色葡萄球菌(26001)等多种传染细菌及流感病毒鼠肺适应株FM1，表现出具有较好的抑菌及抗病毒作用，可望开发一种抗菌及抗病毒海洋新药。     

姜黄素体外抗流感病毒H1N1、H3N2实验研究

目的：观察姜黄素提取物体外对流感病毒H1N1、H3N2的抑制作用。方法：用狗肾细胞（MDCK）观察姜黄素体外对A型流感病毒H1N1亚型、A型流感病毒H3N2亚型病毒的直接杀灭作用。结果：姜黄素最大无毒浓度为12．5g／L,对H1N1有效抑制浓度为6．25g／L,对H3N2有效抑制浓度为1．56g／L。结论：姜黄素提取物确有明显的抗H1N1、H3N2复制作用。     

中药复方板蓝根颗粒抗柯萨奇B_4病毒作用的实验研究

采用中药复方板蓝根颗粒进行了体外抗柯萨奇病毒B4(CVB4)的研究,通过观察病毒引起的细胞病变效应(CPE)、MTT法检测细胞活性,作为考核药物抗病毒作用.结果表明:中药复方板蓝根颗粒对CVB4无直接灭活作用,但能抑制CVB4在Hep-2细胞内的的生物合成和阻止CVB4的吸附,其半数抑制浓度(IC50)分别为1129.00和1130.44μg/mL,治疗指数(TI)均为2.78.在100～1600μg/mL范围内复方板蓝根颗粒与CVB4抑制率呈明显的量效关系(P<0.01),在1600μg/mL时能抑制CVB4在Hep-2细胞内的增殖>50%.研究表明中药复方板蓝根颗粒能有效地抑制CVB4在Hep-2细胞中的增殖,其抗病毒作用发生在阻断病毒吸附细胞和抑制病毒进入细胞之后的复制增殖.     

人参皂苷粉、银杏叶提取物对鸡胚绒毛尿囊膜血管新生的作用

为探讨人参皂苷粉和银杏叶提取物对鸡胚绒毛尿囊膜血管新生的影响,取孵育9天的种蛋,通过暴露鸡胚绒毛尿囊膜来建立模型,28只存活的鸡胚随机分为4组,包含两组空白载体的对照,一组加人参皂苷粉水溶液,一组加含银杏叶提取物药膜,作用3天后,观察分析鸡胚绒毛尿囊膜上血管生长的变化.结果显示:人参皂苷粉组,血管数量明显增多,但血管直径变细,颜色变淡;银杏叶提取物组,血管数量显著增多,血管颜色加深.研究发现:人参皂苷粉既能促进血管生成,又能抑制血管生成,总体表现为抑制;银杏叶提取物能够明显的促进血管的新生.     

H5N1亚型禽流感毒株A/Duck/HuBei/3/2005的分子特征及致病性研究

采用分子生物学方法,对1株2005年从湖北省某县分离获得的禽流感病毒株(A/Duck/HuBei/3/2005)进行全基因组序列测定.序列分析显示,该分离株为H5N1亚型.HA蛋白在HA1和HA2连接处,含有连续多碱性氨基酸模体(-RRKKR-).根据进化分析结果,分离株A/Duck/HuBei/3/2005的7个基因来源于2004～2005年湖南地区流行株(CK/HN/999/05,DK/HN303/04),但是PA基因片段发生了重排,来源于野禽.动物实验显示DK/HB/3/05对鸡和鸭均具有高致病性;对小鼠有较低致病性.     

Prediction of a common neutralizing epitope of H5N1 avian influenza virus by in silico molecular docking

The H5N1 avian influenza virus (AIV) has widely spread in Asia, Europe and Africa, making a large amount of economic loss. Recently, our research group has screened a common neutralizing mono- clonal antibody named 8H5, which can neutralize almost all H5 subtype AIV ever isolated so far. Obvi- ously, this monoclonal antibody would benefit for research and development of the universal AIV vac- cine and design of the drug against H5N1 AIV in high mutation rate. In this study, the homology mod- eling was applied to generate the 3D structure of 8H5 Fab fragment, and "canonical structure" method was used to define the specified loop conformation of CDR regions. The model was subjected to en- ergy minimization in cvff force field with Discovery module in Insight II program. The resulting model has correct stereochemistry as gauged from the Ramachandran plot calculation and good 3D-structure compatibility as assessed by interaction energy analysis, solvent accessible surface (SAS) analysis, and Profiles-3D approach. Furthermore, the 8H5 Fab model was subjected to docking with three H5 subtype hemagglutinin (HA) structures deposited in PDB (ID No: 1jsm, 2ibx and 2fk0) respectively. The result indicates that the three docked complexes share a common binding interface, but differ in bind- ing angle related with HA structure similarity between viral subtypes. In the light of the three HA inter- faces with structural homology analysis, the common neutralizing epitope on HA recognized by 8H5 consists of 9 incontinuous amino acid residues: Asp68, Asn72, Glu112, Lys113, Ile114, Pro118, Ser120, Tyr137, Tyr252 (numbered as for 1jsm sequence). The primary purpose of the present work is to provide some insight into structure and binding details of a common neutralizing epitope of H5N1 AIV, thereby aiding in the structure-based design of universal AIV vaccines and anti-virus therapeutic drugs.     

Prediction of a common neutralizing epitope of H5N1 avian influenza virus by in silico molecular docking

The H5N1 avian influenza virus （AIV） has widely spread in Asia, Europe and Africa, making a large amount of economic loss. Recently, our research group has screened a common neutralizing mono-clonal antibody named 8H5, which can neutralize almost all H5 subtype AIV ever isolated so far. Obviously, this monoclonal antibody would benefit for research and development of the universal AIV vac-cine and design of the drug against H5N1 AIV in high mutation rate. In this study, the homology modeling was applied to generate the 3D structure of 8H5 Fab fragment, and ＂canonical structure＂ method was used to define the specified loop conformation of CDR regions. The model was subjected to energy minimization in cvff force field with Discovery module in Insight II program. The resulting model has correct stereochemistry as gauged from the Ramachandran plot calculation and good 3D-structure compatibility as assessed by interaction energy analysis, solvent accessible surface （SAS） analysis, and Profiles-3D approach. Furthermore, the 8H5 Fab model was subjected to docking with three H5 subtype hemagglutinin （HA） structures deposited in PDB （ID No： ljsm, 2ibx and 2fk0） respectively. The result indicates that the three docked complexes share a common binding interface, but differ in binding angle related with HA structure similarity between viral subtypes. In the light of the three HA inter-faces with structural homology analysis, the common neutralizing epitope on HA recognized by 8H5 consists of 9 incontinuous amino acid residues： Asp^58, Asn^72, Glu^112, Lys^113, lie^114, Pro^118, Ser^120, Tyr^137, Tyr^252 （numbered as for ljsm sequence）. The primary purpose of the present work is to provide some insight into structure and binding details of a common neutralizing epitope of H5N1 AIV, thereby aiding in the structure-based design of universal AIV vaccines and anti-virus therapeutic drugs.     

ZnONPs增敏流动注射化学发光法检测雨水中的H2O2

基于ZnO纳米颗粒(ZnO nanoparticles,ZnO NPs)增敏luminol-H_2O_2化学发光,结合流动注射技术,研究建立一种简单、快速、灵敏地测定雨水中微量H_2O_2的方法。考察pH,ZnO NPs、luminol和H_2O_2浓度对化学发光的影响。在优化条件下,H_2O_2浓度在0.06~20μmol/L范围内,H_2O_2浓度的对数(lg c)和化学发光峰面积的对数(lg A)具有良好的线性关系,检出限(LOD)为0.016μmol/L(3σ)。将此方法应用于雨水中微量H_2O_2的测定,回收率为95%~102%,RSD(n=11)为2.41%。     

A/PR8/34(H1N1)NA基因包装信号对H5N1流感疫苗株NIBRG-14产量的影响

NIBRG-14是采用"6+2"策略制备的一株H5N1灭活疫苗株,其表面抗原HA和NA基因来自于A/Vietnam/1194/2004(H5N1,VN1194),内部基因来自于A/Puerto Rico/8/34(H1N1,PR8),已有研究表明该疫苗株在鸡胚中的产量不佳.本研究发现,在PR8背景下,VN1194NA基因被包装入重组病毒中的效率仅为正常包装量的38%～68%,因此有一部分重组病毒为不含有NAvRNA的缺陷型病毒粒子.本研究通过在VN1194NA基因完整编码区(CDS)的5′和3′两端嵌合PR8NA基因包装信号序列(vRNA3′末端41bp,5′末端67bp)的方法,使重组病毒中NAvRNA的包装效率得到完全恢复,并且病毒在鸡胚的生长滴度提高了10倍,血凝素HA含量提高了约2·7倍,从而为H5N1流感疫苗株的研制提供了新的思考方向.     

Reduction of 1-3 mm iron ore by H2 in a fluidized bed

The reduction of 1-3 mm fine powder of iron ore by H₂ was conducted in a lab-fabricated kg class high temperature fluidized bed. The results show that the differential pressure in the fluidized bed, which has small fluctuation with time, increases with the increase of gas flowing velocity. The utilization ratio of gas decreases when the reaction lasts longer time indicating that the reaction is faster at the beginning of reduction and becomes slower in the latter process. The higher the reaction temperature is, the higher the utilization ratio of gas is, but the difference of utilization ratio among the different temperatures becomes smaller with time. The utilization ratio of gas and the metallization ratio can reach 9% and 84% respectively at 750℃ for 20 min, which shows the reduction reaction by H₂ is very fast. The increase of metallization ratio with gas velocity performs quite good linearity, which shows that a higher velocity of reducing gas can be used to improve the productivity of the reactor when H₂ is used as reducing gas. With the increase of charge height, the metallization ratio decreases, but the utilization ratio of gas increases. The reaction temperature can be reduced to 700-750℃ from 800-850℃ when H₂ is used as reducing gas.