对虾白斑症病毒的分离纯化及形态结构观察

取患白斑症的濒死斑节对虾 (Penaeusmonodon)的表皮、鳃和胃 ,匀浆后通过蔗糖密度梯度离心和蔗糖垫层差速离心两种方案 ,提纯出WSSV ;两种方案比较 ,蔗糖垫层差速离心操作简便 ,不需使用超速离心机 ,所得病毒纯度较高 ,损失少 .负染观察发现 ,纯化的病毒核衣壳 2个末端结构不同 ,其中一端呈圆形 ,高约 2 1nm ,另一端较平 ,高约 15nm ;完整核衣壳的两个末端结构间的螺旋单位一般为 15圈 ,但也偶见个别较长的核衣壳 ,其螺旋单位数达 2 3圈 .     

斑节对虾白斑症的发病历程

目的：探讨对虾白斑症的病程及病症特点,方法：对健康斑节对虾进行人工感染,同时用套式ＰＣＲ检测感染后斑节对虾血液中病毒核酸的相对含量,结果：斑节对虾感染白斑症病毒后,依次表现出厌食,不活动、体色变红、甲壳出现白斑,反应迟钝直至侧卧死亡,濒死对虾的典型症状为空胃、红体、甲壳白斑、甲壳下水肿及甲壳易剥离;感染对虾出现拒食后,其血液中白斑症病毒（ＷＳＳＶ）ＤＮＡ的相对含量急剧增加。结论甲过同步不肿和甲壳易     

大麦黄花叶病抗性机理的初步研究

不同抗性的大麦品种（系）被黄花叶病毒侵染后,叶片中叶绿素,可溶性蛋白质,游离脯氨酸的含量有规律地变化,研究结果表明,感病后,大麦叶片内叶绿素,可溶性蛋白质含量下降,感病品种下降幅度大于抗性品种,而游离脯氨酸含量增加,抗性品种增加的幅度比幅度比感病品种大,同时发现,叶绿素,可溶性蛋白质,游离脯氨酸的含量与病情指数呈显著的负相关。     

Interaction of HIV-1 fusion peptide and its mutant with lipid membrane

HIV_WT and HIV_V2E represent the 23 amino acids fusion peptide of HIV-1 gp41 N terminus and its position 2 mutant (Val→Glu). We have studied the structure-function relationship of HIV_WT and HIV_V2E when they interact with acidic and neutral lipid membranes. The results show that HIV_WT and HIV_V2E have the same conformational characteristics and tendencies of conformational transition but definitely different functions: HIV_WT destabilizes membrane and induces fusion by adopting predominant α-helix conformation when interacting with acidic POPG membrane, its phenylalanine residues can penetrate into the hydrophobic core of POPG bilayer; HIV_V2E also adopts predominant α-helix when interacting with POPG membrane, but it cannot destabilize POPG membrane and induce fusion, the phenylalanine residues of it are located near the surface of POPG bilayer. HIV_WT and HIV_V2E both adopt predominant β-sheet conformation to interact with neutral POPC membrane, and cannot destabilize POPC membrane and induce fusion, the position of phenylalanine residues of both HIV_WT and HIV_V2E are close to the surface of POPC bilayer. These results demonstrate that the N terminal hydrophobicity of fusion peptide and the secondary structure when interacting with lipid membrane play important roles for fusion peptide exerting its function.     

体外快速筛选抗HIV药物的一种新方法

目的:介绍一种体外快速筛选抗H IV药物的新方法。方法:采用荧光染料钙荧光素(Cal-ce in-AM)标记H IV感染的慢性H9细胞(H9/H IV-1ⅢB)与不同稀释浓度的药物作用后,与靶细胞MT-2细胞混合培养,2 h后用荧光显微镜观察MT-2和H9/H IV-1ⅢB融合细胞的变化;孵育3 d后用MTT法检测药物对H IV感染细胞的保护作用和H IV-1p24抗原试剂盒检测药物作用后的细胞培养上清p24抗原含量的变化。结果:药物(双黄连粉针剂)能够抑制MT-2和H9/H IV-1ⅢB细胞融合(双黄连粉针剂抑制融合的EC50为3.18 mg/L,选择指数SI大于314.5);能够保护H IV感染细胞的死亡(EC50为10.59 mg/L,SI大于94.43)和减少H IV-1p24抗原的表达(EC50为23.29 mg/L,SI大于42.9)。结论:运用此方法4~6 h即可初步判断药物是否具有抗H IV的作用,此方法可简便直观,敏感快速进行抗H IV药物的筛选。     

Molecular mimicry in neurological disease: what is the evidence?

Autoimmune diseases are a leading cause of disability and are increasing in incidence in industrialized countries. How people develop autoimmune diseases is not completely understood, but is related to an interaction between genetic background, environmental agents, autoantigens and the immune response. Molecular mimicry continues to be an important hypothesis that explains how an infection with an environmental agent results in autoimmune disease of the nervous system and other target organs. Although molecular mimicry has yet to be unequivocally proven, in the past several years there has been a sharpening of its definition with better experimental data implicating it as a cause of neurological disease in humans. Received 9 July 2007; received after revision 15 November 2007; accepted 27 November 2007     

SV40 association with human malignancies and mechanisms of tumor immunity by large tumor antigen

SV40 was discovered as a contaminate of poliovirus vaccine lots distributed to millions of individuals in the United States between 1955 and 1963 while contaminated vaccine batches were later circulated worldwide. After SV40 was observed to cause in vitro animal and human cell transformations and in vivo tumor formations in animals, the search for a connection between the virus and human malignancies has continued to the present day. Different molecular methods have been used to detect SV40 gene products in a variety of human cancers, though SV40 causality in these tumor types has yet to be established. These data, however, are not without controversial issues related to inconclusive SV40 serological and epidemiological evidence alongside tools and methodologies that may contribute to false-positive results in human specimens. This review will also explore how vaccination against SV40 protein products may be used to help prevent and treat individuals with SV40-expressing cancers. Received 19 September 2006; received after revision 8 November 2006; accepted 13 December 2006     

基于数学模型的计算机病毒随机传播分析

计算机网络系统中有非健康的计算机(已感染计算机病毒)和健康的计算机(未感染计算机病毒),任何两台计算机之间的通信是随机的,当健康的和非健康的计算机通信时是否被感染上病毒也是随机的.如果通过实际数据或经验掌握了这些随机规律,那么我们就可以估计平均每天有多少计算机被感染病毒或者被感染的概率有多大,以及估计的准确性有多大.     

有限资源条件下网络病毒的阻断策略

分析了通过电子邮件途径传播的计算机病毒的特点,探讨了邮件病毒传播模型.在不同的感染率和恢复率条件下,通过变更感染源,分别采用不同的阻断策略.在中国教育网中对病毒的传播和控制进行了演化模拟,提出了在资源有限的条件下复杂网络控制病毒传播的有效策略.