739 
THE PAROTID TUMOR (POLYOMA) VIRUS 
Isolation of Infections DNA from Shope Rabbit Papilloma 
and from SV 40 
Ito reported (1960) isolation of infectious DNA from Shope rabbit 
papilloma, a virus belonging to the same group as the parotid tumor, i.e. 
polyoma, virus. Furthermore, Ito also observed (1961) that the Shope 
rabbit papilloma DNA conserves its infectivity after heating to 100°C for 
30 minutes. In this respect, therefore, the Shope papilloma DNA is also 
similar to the polyoma DNA. Isolation of infectious DNA from SV 40 has 
also been reported (Boiron et al., 1962. Gerber, 1962). 
# * # 
Attempts to transmit neoplasms with nucleic acid preparations isolated 
from oncogenic viruses are obviously of considerable interest. They are 
still, however, in a preliminary phase. Additional studies are needed to 
clarify this fundamental problem. At least in some of the experiments thus 
far performed, the possible presence of live residual virus particles in 
presumably purified nucleic acid extracts has not yet been entirely elimin- 
ated. Furthermore, many of such purified nucleic acid extracts have at 
best only a very slight oncogenic potency. 
REFERENCES 
Anderson, S. G., Hemagglutination by animal viruses. Chapter III, pp. 21-50, in 
vol. 3 “Animal Viruses.” The Viruses. Edited by F. M. Burnet and W. M. 
Stanley. Academic Press, New York and London, 1959. 
Andrewes, C. H., and Horstmann, D. M., The susceptibility of viruses to ethyl 
ether. J. Gen. Microbiol., 3: 290-297, 1949. 
Ashbel, R., Development of tumors in hamsters and rats following the injection 
of mycobacteria. Pubbl. Staz. Zool. Napoli, 28: 12-31, 1956. 
Atanasiu, P., A propos du virus du polyome. pp. 319-322 in: Symposion fiber 
Fragen der Carcinogenese, Berlin (December 11—16, 1959). Akademie-Verlag, 
Berlin, 1960. 
Atanasiu, P., Orth, G., Rebiere, J.-P., Boiron, M., and Paoletti, C., Production 
de tumeurs chez le Hamster par inoculation d’acide desoxyribonucl6ique 
extrait de cultures de tissus infectees par le virus du polyome. Compt. Rend. 
Acad. Sci. (Paris), 254 : 4228-4230, 1962. 
Axelrad, A. A., McCulloch, E. A., Howatson, A. F., Ham, A. W., and Simino- 
VITCH, L., Induction of tumors in Syrian hamsters by a cytopathogenic virus 
derived from a C3H mouse mammary tumor. J. Nati Cancer Inst., 24: 1095- 
1111, 1960. 
Banfield, W. G., Dawe, C. J., and Brindley, D. C., Intracellular and extra- 
cellular particles in tissue cultures inoculated with parotid-tumor agent 
(polyoma virus). J. Nat. Cancer Inst., 23: 1123-1135, 1959. 
Bauer, A., and Constantin, T., Multiplication du virus de Shope dans les cellules 
en culture. Etude au microscope ^lectronique. Conipt. Rend. Soc. Biol., 150: 
246-249, 1956. 
[Appendix C — 156] 
