ISSN:0300-5526    

DOI:10.1159/000149674

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The amino acid composition (AAC) of the coat proteins (CPs) of 126 plant viruses or strains were analyzed by stepwise discriminant analysis. The criteria chosen for discrimination were: (i) the structure of virus particles (3 clusters); (ii) the mode of transmission of the viruses (6 clusters); and (iii) the grouping of viruses according to the classification of the International Committee on Taxonomy of Viruses (23 groups). Statistically significant correlations were obtained with different groups of discriminant amino acids. The results confirm that the AAC of the CPs contains all the information needed for a quantitative classification of plant viruses. These results and possible explanations of these clustering patterns are discussed.

ISSN:0300-5526    

DOI:10.1159/000149675

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The kinetics of Aleutian disease virus (ADV) replication in mink lymphocytes was followed by the analysis of virus-specific antigens, infectious virus, and viral DNA. Stimulation with pokeweed mitogen (PWM; 20 µg/ml) increased the synthesis of ADV DNA in cultivated cells of the B-cell fraction. Maximum virus titers [1065 fluorescence-forming units (FFU)&slash;ml] were achieved after incubating infected cells for 60 h at 32°. At this time, 10.4% of the cells in the B-cell-enriched fraction contained ADV-specific antigens and there was an average of 125 ADV genome equivalents per antigen-positive cell. ADV replication also was detected in T-cell-enriched fractions (with up to 1053 FFU/ml, 5.3% of cells were antigen-positive, with 20 ADV genome equivalents per antigen-positive cell), but was 10 times lower compared with ADV replication in the B-cell fractio

ISSN:0300-5526    

DOI:10.1159/000149676

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

To determine the role of T lymphocytes in adult mice infected with Junin virus, 60-day-old athymic (nu/nu) mice and their immunocompetent (nu/+) littermates were inoculated intracerebrally with 103 TCD50 of the XJ strain. None of them exhibited neurologic illness during a 6-month observation period, and mortality was 3% for nu/nu and 7% for nu/+ animals. The main features in infected nu/nu mice were: (i) high viral titers in brain, reaching a late peak (6.5 log/ml) 32 days postinoculation and persisting at least 6 months; (ii) low, late viremia appearing simultaneously with the viral peak in the central nervous system (CNS) and persisting up to 3 months after infection; (iii) absence of signs of neurologic disease or histologic lesions in brain and almost no mortality; and (iv) lack of detectable circulating antibodies either in IgM or in other immunoglobulins (Igs). Circulating anti-Junin antibodies were demonstrated in IgM and other Igs in immunocompetent mice, although no infectious virus or histologic lesions could be detected. These results show an important role for T lymphocytes in the clearence of Junin virus in the CNS, as demonstrated by viral persistence induced in adult athymic mice.

ISSN:0300-5526    

DOI:10.1159/000149677

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The percentage of suckling mice that developed paralysis after intracerebral Junin virus (XJ-JV pathogenic strain) inoculation (13.8%) consistently increased after 5 serial passages of virus-infected brain or spinal cord obtained from paralytic animals, reaching 37.9 and 45.7%, respectively. As expected, all paralytic mice exhibited an identical spinal cord histologic picture, with widespread JV antigen in spinal cord astrocytes and neurons, particularly the large motor neurons of the anterior horn. These findings strongly support the existence of a motor neurotropic viral particle subpopulation in parental XJ-JV stock.

ISSN:0300-5526    

DOI:10.1159/000149678

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Of the DNA synthesis inhibitors tested, novobiocin, nalidixic acid, coumermycin Al, mitomycin C, hydroxyurea, and bleomycin effectively inhibited Epstein-Barr virus (EBV)-related early antigen (EA) synthesis induced in human lymphoblastoid cells by 12-O-tetradecanoyl-phorbol-13-acetate and n-butyrate, but did not inhibit EA synthesis in cells superinfected with EBV. Inhibition of EA synthesis by treatment with novobiocin, nalidixic acid, or coumermycin Al paralleled that of total cellular DNA synthesis, whereas mitomycin C, hydroxyurea, and bleomycin prevented EA synthesis at higher concentrations than those required for DNA inhibition. Inhibition of EA and total RNA synthesis was not in parallel. The inhibition by novobiocin, nalidixic acid, bleomycin, and hydroxyurea was reversible. Our results suggest that DNA synthesis inhibitors prevent the synthesis of EA in a manner independent of their inhibitory effects on cellular DNA synthesis and that these inhibitors act on a common process of EBV genome activation by different inducing agents.

ISSN:0300-5526    

DOI:10.1159/000149679

出版商:S. Karger AG    

年代:1986

数据来源: Karger

ISSN:0300-5526    

DOI:10.1159/000149680

出版商:S. Karger AG    

年代:1986

数据来源: Karger

ISSN:0300-5526    

DOI:10.1159/000149681

出版商:S. Karger AG    

年代:1986

数据来源: Karger

ISSN:0300-5526    

DOI:10.1159/000149673

出版商:S. Karger AG    

年代:1986

数据来源: Karger