RADIOBIOLOGICAL STUDIES OF VACCINIA VIRUS AND ENCEPHALOMYOCARDITIS VIRUS
Studies of vaccinia virus and encephalomyocarditis virus (EMC) were carried out using 2 types of radiation, ultraviolet light (UV) and Co/sup 60/ gamma rays. The infectivity of both viruses was inactivated by UV according to single-hit kinetics; EMC was also inactivated in a single-hit manner by gamma rays. Vaccinia virus, on the other hand, exhibited a 2-component survival curve when irradiated with gamma rays. The possible reasons for this result are discussed. Infectious centers formed by infecting L60 cells with vaccinia virus or with EMC virus were irradiated at various times during the eclipse period of virus growth (the LuriaLatarjet experiment). When infectious centers of vaccinia virus were irradiated with UV the survival curves remained single-hit for the first 3 hours of the eclipse period, with slopes approximates 1/2 that of the survival curve for the free virus. Starting 4 hrs after infection the survival curves became multiple-hit, but the ultimate slopes remained parallel to the slopes of the survival curves of the early infectious centers. The infectious centers of vaccinia virus exhibited an initial sensitization to inactivation when irradiated with gamma rays. This initial sensitivity persisted for at least 3 hrs, after which time the infectious centers became progressively more resistant to inactivation by gamma rays. The survival curves remained more or less single-hit throughout the eclipse period. Studies with FUdR, an inhibitor of DNA synthesis, showed that the stabilization did not occur in the absence of viral DNA synthesis. Infectious centers of EMC virus became progressively more resistant to UV as virus growth progressed. The survival curves remained singlehit through the eclipse period. Possible interpretations of these results are discussed in the light of present knowledge of the growth of vaccinia and EMC virus. (Dissertation Abstr.)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-18-008192
- OSTI ID:
- 4099971
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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