A New Definition of Virus

Security experts have not formally defined the distinction between viruses and normal programs. The paper takes user＇s intension as the criteria for malice, gives a formal definition of viruses that aim at stealing or destroying files, and proposes an algorithm to detect virus correctly. Compared with traditional definitions, this new definition is easy to understand, covers more malwares, adapts development of virus technology, and defines virus on the spot. The paper has also analyzed more than 250 real viruses and finds that they are all in the domain of the new definition, this implies that the new definition has great practical significance.     

Infectious foot-and-mouth disease virus derived from a cloned full-length cDNA of OH／CHA／99

The China foot-and-mouth virus (FMDV) isolate OH/CHA/99 was isolated from swine, which was unable to infect bovine thyroid cells in vitro or to cause typical disease in bovines following intradermal inoculation in the tongue. To enhance antigenicity, replication, maturation and pathogenicity studies of OH/CHA/99, an infectious fulllength cDNA clone, designated pBIFMDV, was prepared. The in vitro and in vivo biological properties of the virus derived from pBIFMDV were studied by analyzing antigenicity, plaque morphology and virulence in pigs. The results showed that the virus derived from pBIFMDV had the same biological properties as the parent strain OH/CHA/99; the fulllength infections cDNA clone, pBIFMDV, will be very useful in studies of the antigenicity, virulence, pathogenesis, maturation and replication of FMDV.     

Immunogenicity of recombinant fowl-pox virus co-expressing structural protein precursor P1-2A and proteinase 3C of FMDV

Two recombinant plasmids, pUTA2P1 and pUTAL3CP1, were constructed by inserting structural protein precursor P1-2A and proteinase 3C of foot-and-mouth disease virus (FMDV) into fowl-pox virus (FPV) recombinant vectors pUTA-2 and pUTA-16-LacZ respectively, and two recombinant FPVs (vUTA2P1 and vUTAL3CP1) screened by the RT-PCR, IFA assay and Western blotting assay were obtained successfully. Mice injected respectively with rFPVs were induced high level specific anti-FMDV antibodies, increasing of T subtypes, and higher cytotoxicities of splenocytes than those of control groups. These results indicated that a new method was used to construct a potential candidate vaccine of FMDV.     

AC2 and AC4 proteins of <Emphasis Type="Italic">Tomato yellow leaf curl China virus</Emphasis> and <Emphasis Type="Italic">Tobacco curly shoot virus</Emphasis> mediate suppression of RNA silencing

Tomato yellow leaf curl China virus Y10 isolate (TYLCCNV-Y10) alone could systemically infect host plants such as Nicotiana benthamiana without symptoms. In contrast, Tobacco curly shoot virus Y35 isolate (TbCSV-Y35) alone induces leaf curl symptoms in N. benthamiana. When inoculated into transgenic N. benthamiana plants expressing GFP gene (line 16c), TYLCCNV-Y10 neither reverses the established GFP silencing nor blocks the onset of GFP silencing. In contrast, TbCSV-Y35 can partially reverse the established GFP silencing and block the onset of GFP silencing in new leaves. In the patch co-infiltration assays, the AC2 and AC4 proteins of TYLCCNV-Y10 and TbCSV-Y35 could suppress local GFP silencing and delay systemic GFP silencing, suggesting that they are suppressors of RNA silencing. Comparison of the accumulation levels of GFP mRNA in the co-infiltration patches showed that Y10 AC2 and Y35 AC2 proteins had similar efficiency for suppression of RNA silencing. However, Y35 AC4 protein functioned as a stronger suppressor of RNA silencing than Y10 AC4 protein. There-fore, the pathogenicity difference between TbCSV-Y35 and TYLCCNV-Y10 may be related to the functional difference in their AC4 proteins.     

GFP标记的GDNF重组腺病毒载体的构建和体内外表达

通过构建绿色荧光蛋白(GFP)和胶质细胞源性神经营养因子(GDNF)共表达的腺病毒载体,讨论其在治疗脊髓和脑有关神经系统疾病的潜在应用价值,了解腺病毒载体在大鼠体内的分布及在体外分泌外源基因产物能力,并对其生物安全性作了初步考察,为GDNF重组腺病毒载体在临床和基础研究中的应用作了一定准备．     

对新型计算机病毒的认识

对传统型计算机病毒与新型计算机病毒的特点、传播途径等进行了总结和比较,重点介绍了3种最新的计算机病毒的特征及其危害性,它们分别是“苏珊”病毒、“笑脸”病毒和“9·11”计算机病毒。     

浅谈校园网络的安全

介绍了搞好校园网络安全的主要措施,包括加强网络监控、注意密码的安全、及时修补漏洞、设置共享时一定要设定访问密码等。     

Carboxymethytl Pachymaram Up-Regulates Dendritic Cell＇s Function in Hepatitis B Virus Transgenic Mice

The effect of carboxymethytl pachymaram (CMP) on the function of dendritic cells(DCs) derived from spleens of hepatitis B virus transgenic mice are studied in vitro. The phenotypes of DCs are tested by flow cytometry (FCM), cytokines measured by ELISA. The expression of DCs’ phenotypes in HBV transgenic mice are low (CD80⁺CD11c⁺:59.12±11.53 vs 9.60±4.53, p<0.01; CD80⁺ MHC-II⁺: 44.86±12.31 vs 9.80±5.72, p<0.01, normal mice vs HBV transgenic mice), the ability of DCs stimulating T lymphocytes proliferation decreases (0.37±0.11 vs 0.20±0.11, p<0.05, normal mice vs HBV transgenic mice), levels of IL-12 and IFN-γ decrease whereas the level of IL-10 increases; CMP can enhance DCs’ ability of stimulating T lymphocytes proliferation, facilitate the secretion of IL-12 and IFN-γ, inhibit the secretion of IL-10, thus up regulates DCs function. The results show a good prospective use of CMP on the treatment of chronic hepatitis B. Biography: HOU Anji (1963–), male, Ph.D. candidate, Associate professor, research direction: clinical virology.     

病毒的机理与防治

介绍了计算机病毒的概念与机理,分析了蠕虫病毒和特洛伊木马,提出了处理病毒及其威胁的办法,总结了一些安全措施。