ISSN:0300-5526    

DOI:10.1159/000149190

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Although human cytomegalovirus does not induce detectable increases in the levels of bromodeoxycytidine kinase activity in infected cells, bromodeoxycytidine acts as an antiviral agent for the replication of two strains of human cytomegalovirus.

ISSN:0300-5526    

DOI:10.1159/000149191

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The inhibition of herpes simplex virus type 1 (HSV-1) plaque formation by acycloguanosine (ACG) was assayed in human fetal lung fibroblasts (HL), cell lines from human cervical carcinoma, rabbit cornea, and human rhabdomyosarcoma, and three green monkey kidney cell lines. The ACG concentration giving 50% plaque reduction (PR50) of HSV-1 was lowest in HL. In two green monkey kidney cell lines, HSV-1 plaque formation was relatively insensitive to ACG, with PRso of 25 and 60 µM, respectively. In the other cells, HSV-1 showed an intermediate sensitivity to ACG. Also, HSV-2 was more sensitive to ACG in HL than in monkey kidney cells. HSV-1 plaque reduction on HL cells was studied as a function of increasing virus MOI with a constant concentration of ACG. An increased MOI decreased the sensitivity to ACG. The sensitivity of cytomegalovirus (CMV), strain Ad. 169, and four fresh CMV isolates to ACG was studied in HL cells. At low MOIs, three of the five CMV strains were somewhat sensitive to ACG, PRso values ranging from 60 to 450 µM ACG. At high MOIs none of the virus strains were sensitive. ACG at concentrations of 200 µM or less did not significantly affect host cell DNA synthesis, as measured by 3H-thymidine incorporation. In cell culture, the inhibition of herpesviruses by ACG appears to be complex, depending on the type of virus, virus concentration, type of host cells, and condition of the cel

ISSN:0300-5526    

DOI:10.1159/000149192

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The Holland strain of anatid herpesvirus (AHV) was 2- to 10-fold more efficiently plaqued under liquid medium or semisolid medium containing methylcellulose than in media containing agar, agarose, or Nobel agar. Virus adsorption was complete in 45 min, with the maximum virus titers obtained under liquid medium at 48 h postinfection. The AHV dose-response curve was linear. Pekin duck embryo cultures were more efficient than CCL-141 in plaque response and gave the maximum virus yield per cell. Virus titers were independent of avian cell passage number (to 6), fetal or newborn calf sera (to 10% v/v), and the presence of polyions during adsorption. The host range included cells from several species of Anseriformes and Galliformes.

ISSN:0300-5526    

DOI:10.1159/000149193

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Rat (3Y1) cells transformed by wild-type adenovirus type 12 or the temperature-sensitive mutant ts401 with an active function required for transformation maintenance were exposed at the permissive (36°) or nonpermissive (40°) temperature to cytochalasin B (CB). At 40°, the ts401 -transformed cells, but not the wild-type transformants, exhibited, at least partially, the untransformed 3Y1 cell phenotype; most of the cells became bi- and trinucleated and DNA synthesis was inhibited. At 36°, both groups of cells became highly multinucleated, and there was no apparent inhibition of DNA synthesis by CB. These characteristics were exhibited also by the wild-type transformants at 40°. These findings provide additional evidence that an active 401 gene function is required for maintenance of the adenovirus-transformed cell pheno

ISSN:0300-5526    

DOI:10.1159/000149194

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The immunoperoxidase technique was employed to localize, at the ultrastructural level, protein Pr76 (a precursor of the ‘gag’ gene protein of avian leukemia and sarcoma viruses) in chick embryo cells infected with RSV-RAV-2 virus. The protein was confined to free and membrane-bound ribosomes. This was often particularly conspicuous in the peri-nuclear region. No staining was found in the ergastoplasmic cisternae, in the Golgi apparatus, or in the nucleus. This pattern of localization is compatible with previous studies where the protein was searched for in various cell subfracti

ISSN:0300-5526    

DOI:10.1159/000149195

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The virion polypeptides of the Tupaia (tree shrew) adenovirus were analyzed by SDS-polyacrylamide slab gel electrophoresis and by isoelectric focusing. The viral proteins from either nonradioactive or 35S-methionine-labeled virions formed distinct patterns of at least 15 polypeptides which were different from those of known human and animal adenoviruses. Two-dimensional analyses revealed the presence of 18 discernible polypeptides.

ISSN:0300-5526    

DOI:10.1159/000149196

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Competition radioimmunoassays for the 27,000 molecular weight (p27) major internal protein and the low-molecular-weight 10,000–12,000 (p10–12) polypeptides of the primate type-D retroviruses, Mason-Pfizer virus (MPV) and langur virus (LV), were established. Type-D isolates from various primate and human tumor cells were examined in both these assays. There were no detectable immunological differences between MPV and two type-D retroviruses previously reported to be isolated from human cell lines (HeLa and AO). Type-D retroviruses isolated from human T9 and J96 cells (cell lines derived from human leukemic cells), however, were clearly distinguishable from both MPV and LV in their respective p10–12 radioimmunoassays. These assays thus demonstrate that type-D retroviruses isolated from some human cells may differ immunologically from morphologically similar viruses isolated from nonhuman pri

ISSN:0300-5526    

DOI:10.1159/000149197

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Healthy common marmosets from two separate colonies, one in England and one in France, were found to have antibodies cross-reacting with Epstein-Barr virus structural antigens (EBV-VCA). All seropositive animals were at least 2 years old. Experimental EBV infection of marmosets of different ages led to seroconversion of inoculated weanlings. Adult animals either developed antibody for the first time or showed an increase in their existing titers. Both control and infected animals developed a progressive interstitial nephritis. The lymphocytic infiltration was more extensive, diffuse and immature in appearance in inoculated animals, but no definite evidence of lymphoproliferative disease or lymphoma was found.

ISSN:0300-5526    

DOI:10.1159/000149198

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The RNAs from four tobamoviruses [tobacco mosaic virus (TMV) vulgare, TMV dahlemense, TMV U2, and the cowpea strain of TMV (CCTMV)] were translated in a cell-free ribosome system from reticulocytes. Among the translation products found were two poly-peptides with molecular weights of 170,000 and 120,000 which were produced by all the viral RNAs tested. These two polypeptides comigrated with the corresponding virus-specific proteins synthesized in tobacco protoplasts infected with any of the four tobamoviruses. A 30,000 molecular weight protein was encoded by all four RNAs. However, this protein was synthesized in different amounts and differed slightly in size for each virus. When TMV vulgare or dahlemense RNAs were used as templates, this protein was one of the major translation products, whereas trace amounts were produced in the presence of U2 or CcTMV RNA. Only the CcTMV RNA directed the in vitro synthesis of a protein which had about the same electrophoretic mobility as coat protein.

ISSN:0300-5526    

DOI:10.1159/000149199

出版商:S. Karger AG    

年代:1980

数据来源: Karger