摘要:

6/94 virus, isolated originally from a multiple sclerosis (MS) patient, was compared antigenically with related parainfluenza type 1 strains. These included two Sendai strains of mouse and two Sendai strains of reported human origin as well as the HA2 strain. By standard hemagglutination inhibition (HI) or hemadsorption neutralization (HAD-N) tests or by the complement-fixation (CF) cross-block titration test for detecting surface antigens, 6/94 virus and the Sendai virus strains were indistinguishable from each other but distinct from the HA2 strain. By the kinetic HI test, however, 6/94 virus could be readily differentiated from the Sendai viruses isolated from mice and more closely resembled those recovered from man.

ISSN:0300-5526    

DOI:10.1159/000149875

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The in vivo properties of four host range temperature-sensitive (ts) mutants of herpes simplex virus type 2 (HSV-2) were correlated with known in vitro characteristics. Mutants and parental virus were inoculated into newborn and weanling mice and weanling hamsters by intracranial and subcutaneous routes, and into weanling rabbits by corneal scarification. In all cases the pattern of attenuation of mutants in vivo correlated with their stability in vitro at 39°. The most attenuated mutant (mutant 69) was also the most consistent in its inability to induce cytopathic effects (CPE) in vitro or to replicate under nonpermissive conditions. Conversely, the most virulent mutant (mutant 41) was the least stable under nonpermissive conditions

ISSN:0300-5526    

DOI:10.1159/000149876

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Limited tryptic digestion of p30 antigen (the major internal viral protein) of type C viruses isolated from hamster, rat, and gibbon ape yielded a polypeptide fragment with a molecular weight of approximately 10,000 daltons. Some antigenic determinants with interspecies specificity were retained on these polypeptides, which in serological tests cross-reacted with antibody produced previously against a similar fragment obtained from mouse p30. Exhaustive trypsinization resulted in further fragmentation with concomitant loss of serologic activity. The results suggest that all mammalian type C virus p30s have an antigenically related polypeptide core which is not readily digested by trypsin.

ISSN:0300-5526    

DOI:10.1159/000149877

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

When viral envelope antigens (VEAs) and virus-associated cell surface antigens (CSAs) are used as markers of type C viruses, more heterogeneity of virus populations can be demonstrated than by using host range alone. In the present study, four CSAs (PCI, X.l, GCSA, and MEV-SA1) and three VEAs (xVEA, xl-VEA, and sub-gsVEA) were used as markers of virus populations present in various sublines of the BALB/c embryonic fibroblast BALB/3T3 clone A31 line. Of four spontaneously transformed sublines, two released N-tropic endogenous type C viruses spontaneously after long-term culture and each had distinct antigenic patterns. Treatment with 5-bromodeoxyuridine (BrdU) resulted in the detection of X-tropic viruses in all four sublines. The expression of these X-tropic viruses was associated with two different antigenic patterns. When the clonal rabbit corneal SIRC cell line was infected with the X-tropic viruses obtained after BrdU treatment, the cells acquired detectable amounts of only one of the antigenic markers.

ISSN:0300-5526    

DOI:10.1159/000149878

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Primary tumors induced in newborn hamsters by simian adenovirus SA7 were investigated in transfection experiments. Infectious DNA-protein complexes were readily detected in both the supernatant and pellet fractions obtained by a modified Hirt extraction procedure; DEAE-dextran was required for infectivity to become manifest. Infectivity could be abolished by exposure to DNase, but it was unaffected by SA7-specific antiserum or RNase, and only partially inactivated by trypsin treatment. SA7 tumor cells serially passaged either in tissue culture or in hamsters yielded infectious DNA complexes much less frequently and appeared to evolve into nonyielder cell lines. When large numbers of cells were lysed, intact virus could be recovered from all the primary tumors and from some of the subcultured cell lines. There was a correlation between the persistence of complete virus and the presence of infectious DNA-protein complexes. When the tumor cells carried very small amounts of intact virus, infectious DNA complexes could still be detected; when virus could no longer be detected in the tumor cells, infectious DNA complexes could no longer be found. The results suggest that a portion of the infectious DNA moieties exists as viral DNA-protein complexes in the tumor cells.

ISSN:0300-5526    

DOI:10.1159/000149879

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A study of an outbreak of tick-borne encephalitis (TBE) in a natural focus of this infection at Závada village (Slovakia) led to the conclusion that apparently the epidemic was caused by consumption of fresh sheep cheese and infection of persons occurred by the alimentary route. To our knowledge, this is the first record of this source of infection in man

ISSN:0300-5526    

DOI:10.1159/000149880

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Primary ovarian and hemocyte tissue cultures prepared from Estigmene acrea larvae were infected with Amsacta moorei entomopoxvirus. Infection of cultures was achieved with either purified virus or virus-containing culture medium from infected cultures. Virus replication and formation of virus-containing inclusions (VCI) were similar to that normally observed in vivo except that fewer virions appeared to be occluded in VCI.

ISSN:0300-5526    

DOI:10.1159/000149881

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Optimum conditions for in vitro RNA synthesis by the entomopoxvirus from Amsacta moorei, except for a temperature optimum of 26°, were similar to those reported for vaccinia. Incorporation of 3H-ATP in the presence of CTP, GTP and UTP was significantly inhibited by actinomycin D; incorporation of 3H-ATP alone was not. The products formed by incorporation of 3H-ATP alone or with the three other nucleotides contained polyadenylic acid sequences. The sedimentation coefficient of the 3H-ATP-labeled product formed in the presence of CTP, GTP and UTP was reduced from 8–23S to 3–5S after RNase treatment. The product formed from 3H-ATP alone had an apparent sedimentation value of

ISSN:0300-5526    

DOI:10.1159/000149882

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:0300-5526    

DOI:10.1159/000149883

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:0300-5526    

DOI:10.1159/000149884

出版商:S. Karger AG    

年代:1975

数据来源: Karger