摘要:

Following SV40 infection of CV-1 monkey cells, cytosol thymidine (dT) kinase activity increased 4- to 10-fold. This enzyme was not significantly different from the cytosol dT kinase of uninfected cells with respect to mobility, isoelectric point, sedimentation coefficient, and phosphate donor specificity. Monkey mitochondria contain a distinctive dT kinase isozyme localized in the mitochondrial matrix. The distinctive mitochondrial isozyme had a higher electrophoretic mobility, lower isoelectric point, and smaller sedimentation coefficient than the cytosol dT kinase, and could utilize either ATP or UTP as phosphate donor; it did not increase after SV40 infection. Mitochondria also contained a cytosol-like dT kinase which was enhanced in infected cells. These findings suggest that SV40 infection derepresses the normal cytosol dT kinase of host cells.

ISSN:0300-5526    

DOI:10.1159/000149417

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Treatment of the isolated Sindbis virus envelope with proteolytic enzymes causes inactivation of the hemagglutinin (HA) but leaves the complement-fixing (CF) activity unaffected. Analysis by chromatography of the products of the trypsin digested envelope preparations (pre-labeled with different radioactive precursors) revealed: (1) the CF activity always separates as a single distinct peak; (2) the ‘glycopeptide’ part of the glycoprotein molecule separates as a homogeneous peak and has a molecular weight close to 14,000; (3) the CF activity is associated with the polypeptide, and not with the sugar part, of the glycoprotein molecule of the envelope. In spite of the low titer of HA in the trypsin-digest of the envelope, such preparations induce in rabbits the production of high-titer hemagglutination-inhibition antib

ISSN:0300-5526    

DOI:10.1159/000149418

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The kinetics of the hemolysis caused in human erythrocytes by Sendai virus is strongly dependent on the virus-to-erythrocyte ratio.Two processes appear to take place: a reversible one where the virus binds to the cell membrane, causes a lesion and eventually hemolysis, and is then slowly eluted in a still active form; and an irreversible one, possibly related to fusion of the viral envelope with the erythrocyte membrane, which results in the inactivation of the virus. The extent of hemolysis depends on the relative rates of the two processes, and the final number of lysed cells is approximately proportional to the logarithm of virus concentration. The kinetics of the process is sigmoid at high virus-to-erythrocyte ratios and hyperbolic under conditions where a virus particle causes the lysis of several cells before completion of the process.

ISSN:0300-5526    

DOI:10.1159/000149419

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The sedimentation analysis and polyacrylamide gel electrophoresis of RNA extracted from Lumbo and Tahyna viruses, which belong to the California group of the Bunyamwera supergroup of arboviruses, demonstrated the existence of three RNA species with molecular weights of 2.9 × 106, 2 × 106 and 0.5 × 106 daltons. In control experiments, the same extraction procedure failed to break down the 42S Sindbis virus RNA. The three RNA species cannot be denatured by heating or DMSO treatme

ISSN:0300-5526    

DOI:10.1159/000149420

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

An indirect hemagglutination (IHA) test with Congo and Crimean hemorrhagic fever (CHF) viruses employing sheep erythrocytes sensitized with immune γ-globulin was developed. The titer of the IHA test with sucrose acetone antigens of the virus reached 1:16,000–1:32,000; the reaction was specifically inhibited in the presence of immune sera and sera of CHF-convalescent patients. High sensitivity and specificity of the reaction recommend it for the serodiagnostics of C

ISSN:0300-5526    

DOI:10.1159/000149421

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The isolation of Sindbis virus from the blood of sentinel animals (chickens and ducks) in June and August was evidence for circulation of this virus in a biotope investigated in Western Slovakia. The vector of the virus may be the Culex pipiens or the Mansonia richiardii mosquito. Neutralizing antibodies against Čalovo and Ťahyňa viruses as well as Sindbis virus were found in the sera of sentinel anima

ISSN:0300-5526    

DOI:10.1159/000149422

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Three enzyme activities have been shown to be associated with the cytoplasmic polyhedrosis virus (CPV) of Bombyx mori: an RNA polymerase, a nucleotide phosphohydrolase (NTPase) and a nuclease. They all require Mg++ ions for optimum activity and have a similar pH and temperature optimum. The kinetics of inactivation of the three enzymes showed that the NTPase and the nuclease had similar stabilities whereas the RNA polymerase was rapidly inactivated. The nuclease and the polymerase are both ATP-dependent. We suggest that the three CPV enzyme activities are all associated with the one enzyme complex.

ISSN:0300-5526    

DOI:10.1159/000149423

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Seven different laboratory strains of SV40 were compared for their ability to induce SV40 tumor-specific transplantation antigen (TSTA) in BALB/c mice. Five different isolates of virus rescued from transformed cells of mouse, hamster and monkey origin were also analyzed. All the various virus isolates were found to induce a common TSTA.

ISSN:0300-5526    

DOI:10.1159/000149424

出版商:S. Karger AG    

年代:1973

数据来源: Karger

ISSN:0300-5526    

DOI:10.1159/000149425

出版商:S. Karger AG    

年代:1973

数据来源: Karger