摘要:

The progression of Junin virus infection was studied in congenitally athymic mice. Immunocompetent littermates were used as infected controls. As expected, the latter developed lethal encephalitis, with viremia and considerable viral replication in the brain. The mortality rate was almost 100%; the few surviving controls exhibited high serum neutralizing antibody levels and a total absence of virus in blood and brain. In contrast, nude mice did not contract the disease; all survived with persistent viremia and virus in brain, but no serum neutralizing antibodies were detected. These results confirm previous research on thymectomized mice and those treated with anti-lymphocyte serum and tend to support the important role of cellular immunity in the pathogenesis of this viral disease.

ISSN:0300-5526    

DOI:10.1159/000149330

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The kinetics of replication of lactate dehydrogenase-elevating virus (LDV) in age-dependent polioencephalomyelitis was studied in genetically susceptible (C58/J) and resistant (C57BL/6J) mice. The peripheral replication pattern (plasma concentration) for LDV was similar in both strains. However, the concentration of virus within the central nervous system was strikingly different. In nonsusceptible C57BL/6J mice, little or no virus was found within the central nervous system. In the lumbar cord of susceptible C58/J mice, an increase in the concentration of LDV began 5 days postinfection and continued during the preclinical stages of disease. A direct correlation was shown between the concentration of LDV in spinal cord and the appearance of motor neuron disease but not the degree of inflammatory reaction.

ISSN:0300-5526    

DOI:10.1159/000149331

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The role played by the gut juice of insects in the infective process of insect viruses was examined. Analysis of larval gut extract of Heliothis armigera by SDS-PAGE revealed protease activity associated with components of molecular weights 48,000 and 94,000. Proteases were found to be associated with occlusion bodies and virions of both nuclear polyhedrosis virus (NPV) and cytoplasmic polyhedrosis virus (CPV) infecting H. armigera. CPV occlusion bodies were dissolved by gut juice extract at pH 8.0, trypsin and chymotrypsin at pH 8.0, and carbonate-chloride solution at pH 10.5. Trypsin treatment was selective for occlusion bodies of CPV at pH 8.0, whereas solutions more alkaline than pH 10.0 without added enzymes were adequate to digest NPV occlusion bodies. This property was used to identify and separate the two types of viruses from a mixed infection. Gut extract proteases have characteristics similar to those of trypsin.

ISSN:0300-5526    

DOI:10.1159/000149332

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Using a guinea pig model of genital herpes simplex virus (HSV) type 2 infection, phosphonoformate treatment initiated after the onset of symptoms had a therapeutic effect on the outcome of disease. Severity of disease, viral shedding, and HSV-induced cellular changes in vaginal cytology were significantly reduced in drug-treated animals as compared to sham-treated animals, although virus was readily detected in the nervous system of animals from both groups. The percentage of animals harboring latent virus in their dorsal root ganglia was approximately the same in both drug-treated and sham-treated animals. No drug toxicity was found.

ISSN:0300-5526    

DOI:10.1159/000149333

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Membrane particles possessing receptor activity for influenza virions have been reconstituted following solubihzation of human erythrocyte membranes with octyl glucoside (OG) and fractionation on a DEAE-cellulose column. Fractions that eluted with 1.5 MNaCl yielded, after removal of OG, reconstituted membrane particles (RMP) which could bind virus and inhibit hemagglutination. RMP contained essentially two membrane proteins (glycophorin and a nonglycosylated protein of molecular weight 29,000), two phospholipids (sphingomyelin and phosphatidylcholine), cholesterol, and gangliosides. Incubation of influenza virus with RMP at 4° resulted in the formation of a virus-RMP complex (liposomes). The specificity of the receptor was demonstrated by inhibition of viral attachment when RMP were treated with neuraminidase or preincubated with rabbit anti-M or anti-N antiserum, suggesting that both the carbohydrates and peptide moiety may play a role in attachment. Calculations suggest that there are 6 × 103 JV-acetyl neuraminic acid residues per attached virion. This system provides a simple and gentle means of reconstituting membrane components to study receptor activit

ISSN:0300-5526    

DOI:10.1159/000149334

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The cytogenetic effect of two strains of Junin virus on bone marrow chromosomes of the guinea pig was studied. Animals infected with the attenuated strain XJ-CI3 showed no differences from control animals. Guinea pigs inoculated with the pathogenic strain XJ exhibited a significant increase of abnormal cells, chromatid breaks, and chromosome fragments. The clastogenic ability of the XJ strain is similar to the reported effect of other viruses, while the XJ-CI3 strain does not appear to be clastogenic.

ISSN:0300-5526    

DOI:10.1159/000149335

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Immunoprecipitation was used to study Epstein-Barr virus-specific polypeptide synthesis in Raji cells after chemical induction of the viral cycle. The results indicate that Raji cells fail to synthesize a few early and both late polypeptides. Comparison with P3HR-1 virus superinfection experiments at different MOIs indicates that some of these early polypeptides are required for virus DNA replication. The results are compatible with what is known about the complexity of viral DNA in Raji cells.

ISSN:0300-5526    

DOI:10.1159/000149336

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The possibility of complementation between herpesvirus papio (HVP) and Epstein-Barr virus (EBV) was investigated. Strain 594S-F9 of HVP, unlike strain P3HR-1 of EBV, is not capable of inducing virus antigen synthesis in the EBV genome-carrying, nonproducer lymphoma cell line Raji. The effects of dual infection with these viruses were studied. With untreated viruses, the percentage of cells positive for viral antigens was equal to or slightly less than that in cultures infected with P3HR-1 virus only. However, if UV-irradiated P3HR-1 virus was employed in the dual infection, the relative number of virus antigen-positive cells was enhanced over cultures infected with P3HR-1 virus alone. These results suggest functional complementation between EBV and HVP.

ISSN:0300-5526    

DOI:10.1159/000149337

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Human umbilical cord blood lymphocytes were immortalized by infection with Epstein-Barr virus (EBV) in the presence of various concentrations of dimethyl sulfoxide (DMSO). 13 continuous lymphoblastoid cell lines were established. DMSO did not affect the efficiency of transformation and establishment of these lines. After a period of 2 months in culture, the lines were tested for EBV production by lethal irradiation (6,000 rad) from a 60Co source and subsequent cocultivation with primary umbilical cord lymphocytes. Cell lines transformed in the presence of 2% DMSO yielded transforming activity in 46.6% of test cultures, compared with 9.5% for lines established without DMSO in the medium. These findings imply that a permanent change in the host/virus relationship resulted from a brief exposure (48 h) to DMSO at the time of transformation.

ISSN:0300-5526    

DOI:10.1159/000149338

出版商:S. Karger AG    

年代:1983

数据来源: Karger