Virus In Hamsters Research Articles

Immunological identity of the group-specific antigen of hamster-specific C-type viruses and an indigenous hamster virus.

SUMMARY Antisera prepared in guinea-pigs against a purified internal virion antigen of a hamster-specific C-type virus reacted with an ether-stable antigen derived from several hamster-specific viruses and an indigenous hamster virus. Reactions of identity were obtained in immunodiffusion tests between all virus preparations while no reactions were obtained with uninfected cells and murine C-type virus preparations. Guinea-pig antiserum to the murine C-type virus gs antigen did not react with any of the hamster virus preparations. This pattern of specificity was maintained in complement-fixation tests. Based on these data and the envelope antigen identity of the hamster-specific sarcoma viruses established in the accompanying paper, these viruses, originally recovered from hamster tumours induced by murine sarcoma viruses, are considered to be pseudotype sarcoma viruses possessing the antigens of the indigenous hamster C-type virus and the sarcoma gene(s) of the original tumour inducing murine viruses. Our current preferred nomenclature for the hamster-specific viruses is based on these considerations.

Investigations on virus production in RSV mammalian tumours.

SUMMARY Six different Rous mammalian tumour lines were studied for the occurrence of virus specific antigens, the presence of the viral genome and the synthesis of infectious and non-infectious particles. Four Rous tumour lines were induced in stumice presumably free from latent murine leukemia virus (MLV), three of them by a cloned Schmidt-Ruppin strain of Rous sarcoma virus (sr-RSV) belonging to sub-group D, the fourth with an uncloned sr-RSV strain. In addition a Prague(P)-RSV induced mouse tumour line (RVP3) and an sr-RSV induced hamster tumour line (RSH) and sr-RSV induced chicken tumours were likewise investigated. In all mammalian lines, except for RVP3, avian leukosis group specific complementfixing antigen was found. Tumour specific transplantation antigen was demonstrated in all mammalian lines except RSH, whereas no infectious RSV could be detected in any of the mammalian tumours. Likewise electron microscopy revealed no virus particles in more than 9500 cell sections of RSV-stu tumours, but the viral genome was shown to be present by transfer of the tumour to chickens. In the RVP3 line virus particles were detected resembling typical murine leukemia virus while in the RSH line particles were found morphologically similar to the latent hamster virus described by Bernhard & Tournier (1964). The interpretation and significance of the findings are discussed.

Studies on the pathogenesis of parainfluenza type 3 virus infection in hamsters.

After intranasal inoculation of parainfluenza type 3 virus in hamsters, viral multiplication was detectable by infectivity titrations and immunofluorescent (FA) staining to have occurred in respiratory tissues as early as 24 hours following inoculation. Virus persisted in the respiratory epithelium up to the 6th day of infection. By FA staining, localization of viral antigen was seen in the cytoplasm of infected ciliated epithelial cells in the form of brilliant fluorescent granules of varying size.

Biological characteristics of primary tumors induced by polyoma virus in hamsters.

AbstractEleven primary subcutaneous tumors induced by polyoma virus in hamsters were analyzed for morphology, growth capacity in vitro, transplantability and karyology. In most cases, cultures prepared from these tumors grew for a few generations and then degenerated with loss of a majority of cells; from the few surviving cells, a population emerged that was able to grow indefinitely in vitro.The initial explanted population differed from that which emerged from the degenerative phase in its susceptibility to the toxic activity of 3,4‐benzo (a)pyrene and in its high MTD (median tumor dose) values (105–106 cells) when transplanted in adult hamsters. The MTD decreased to 102–103 cells with prolonged growth in vitro. Cultures derived from the transplanted tumors grew permanently in vitro and had low MTD values. All the tumors were aneuploid with a prevalent near‐diploid mode and remained so even after prolonged growth in vitro. No common karyotypic changes were observed, but in 4/8 tumors there was a chromosome marker longer than the X. The long chromosome of the various lines differed in the arm ratios. The occurrence of monosomy and trisomy of pairs ≠1 and ≠21 was not random in 4/8 primary tumors.A comparison with previous studies of hamster embryo cells infected in vitro with polyoma virus indicates that there is a strong parallelism in the biological properties and progression toward neoplasia between cell populations infected in vivoor in vitro by the virus.

STUDIES OF ONCOGENICITY OF ADENOVIRUS TYPE 7 VIRUS IN HAMSTERS.

SummaryAll of 3 strains of type 7 ade-novirus isolated in primary human embryonic kidney cell cultures from respiratory secretions of human subjects with acute respiratory illness proved oncogenic for newborn hamsters. The type 7 viruses were isolated and propagated in human embryonic cell cultures and were free of extraneous agents. Detailed information relative to the virology, oncology, pathology and immunology of the type 7 adenovirus-hamster tumor system is presented. The tumors appeared after a long latent period, were highly malignant, were readily transplantable and were free of detectable infectious virus. The cells in most of the tumors were sufficiently differentiated to permit a pathologic diagnosis of malignant lymphoma, or lymphosarcoma when evidence of invasiveness was present. A majority of tumors induced by the virus presented a specific complement-fixing antigen which reacted with sera from hamsters bearing homologous tumor.The authors are indebted to T. Beddow, W. Clark, P. Gosnell, B. ...

The Development of a Neurotropic Strain of Measles Virus in Hamsters and Mice

The study of measles virus in experimental animals has received considerable attention over the years. Early data (reviewed by Enders, 1940) were conflicting and poorly documented. The difficulty in much of the earlier work was the lack of a suitable means for demonstrating the presence of virus. The tissue culture studies of Enders and Peebles (1954) (and of many others since) provided the previously unavailable virus indicator system. In recent years experimental measles has been studied in the monkey (Taniguchi et al, 1954; Peebles et al, 1957), the dog (Ryszantseva, 1956; Moura and Warren, 1961), the mouse (Imagawa and Adams, 1958; Carlstrom, 1958), and the hamster (Burnstein et al, 1958; Waksman et al, 1962). Studies in rodents are of particular interest in that the site of infection is the central nervous system. The fact that measles virus can replicate in nervous tissue appears important since the pathogenetic mechanism of measles encephalomyelitis is still not understood.

ONCOGENIC EFFECT OF HUMAN ADENOVIRUS TYPE 12, IN MICE.

Undifferentiated malignant tumors were induced at the site of injection of human adenovirus type 12 into newborn mice of the C(3)H(f)/ G(8). strain, but not of the DBA(f), or A(f) strains. The tumors were grossly and histologically similar to those induced by this virus in hamsters, but appeared in a smaller percentage of injected mice than hamsters.

Quantitation and morphology of equine abortion virus in hamsters

Infection of hamsters with equine abortion virus results in a fulminating disease that terminates fatally in 18–21 hours. In the latter half of this infection, the plasma and extracts of liver tissue contain particles in large numbers that the authors believe are the virus elementary bodies. By electron microscopy, the particles are round with average diameter 170 mμ; many have a tail of about 50-mμ width and variable length up to 340 mμ. They first appear about 9 hours after infection and increase rapidly in number to 10 11 per gram in the terminal stages. The particles appear and increase in parallel with the infectious titer of the tissues involved. Their number is consistent with the frequency of their appearance in electron micrographs of thin tissue sections.

Influence of Cortisone and "Stress" upon Persistence and Multiplication of MEF1 Virus in Hamsters.

Influence of Cortisone and "Stress" upon Persistence and Multiplication of MEF1 Virus in Hamsters.

Studies on Chick-Embryo-Adapted-Rabies Virus

Summary After prolonged cultivation in the developing chick embryo the Flury strain of rabies virus lost its pathogenic properties for mice 14 days of age or older when injected intracerebrally. Suckling mice still remained fully susceptible. Dogs and rabbits were fully resistant to intracerebral inoculation of the virus, whereas rhesus monkeys were found to be almost as susceptible as baby mice. Results of titrations of the virus in hamsters and guinea-pigs indicated the virus preparation was not homogeneous. Experiments are described in which different segments of the viral population were separated and analyzed. The existence of different forms of virus in different stages of adaptation is discussed.

The Inter-Relation of Age, Immune Response, and Susceptibility to Mumps Virus in Hamsters

Summary Direct comparison of mumps virus growth and antibody response has been made in hamsters inoculated at various ages. Hamsters, of an age at which inoculation of virus does not cause apparent disease, produce antibody earlier and in relatively greater amounts than do younger hamsters in which the mumps virus causes a fatal encephalitis. Older hamsters are susceptible to mumps virus if the incubation period is shortened so that death occurs before high serum antibody levels are established.

Some observations on interference between neurotropic viruses.

Studies have been carried out on the interference phenomenon with certain neurotropic viruses in experimental animals. The primary object was to investigate claims that material containing human poliomyelitis virus interferes with the progress of the infection by the MM virus in hamsters, or the Lansing virus in mice. We have failed to find evidence that the inoculation of specimens known to contain human poliomyelitis virus interferes with the progress of MM or Lansing virus infections, and we do not believe that the interference phenomenon can be used in this way as a diagnostic test. In the course of this investigation, it was found that interference occurs when hamsters are inoculated cerebrally with lymphocytic choriomeningitis virus, and, four to seven days later, with the antigenically unrelated MM virus by the peritoneal route. A significant number of such treated animals are spared from developing paralysis due to the MM virus. Evidence was also obtained that under certain circumstances the inoculation of MM virus may lessen the severity of the illness due to lymphocytic choriomeningitis virus injected several days earlier.

Comparison of Newcastle Virus in Hamsters Exposed by Intracerebral Injection and Intranasal Instillation

Infected hamster brains from the 300th intracerebral passage and from the 4th intranasal passage titred lO-4.77, whereas infected brains from the 7th intranasal passage titred 10-3.66. Positive Newcastle chicken serum neutralized the virus from the 245th and 300th hamster passage, whereas normal chicken serum had no effect.