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Cytopathic Protective Factor: its Production by Normal Uninfected Serum-free Cell Cultures

Naturevolume 192pages11011102 (1961) | Download Citation



AT the present time two well-defined systems of viral interference by cell products have been demonstrated in vitro. They are interferon1 and viral inhibitory factor2, the latter possibly being a variety of interferon. Both at least have in common the fact that they are produced in cell cultures infected with virus, active virus in the case of the latter, or inactivated where interferon is concerned. Other differences and similarities are discussed in a recent report by Ho and Enders3. It is well known that virus inhibitors are present in a variety of mammalian tissues and fluids4 and may be demonstrated either in vivo or in vitro.

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  1. 1

    Isaacs, A., and Lindemann, J., Proc. Roy. Soc., B, 147, 258 (1957).

  2. 2

    Ho, M., and Enders, J. F., Proc. U.S. Nat. Acad. Sci., 45, 385 (1959).

  3. 3

    Ho, M., and Enders, J. F., Virology, 9, 446 (1959).

  4. 4

    Tamm, I., and Horsfall, F. L., Proc. Soc. Exp. Biol. Med., 74, 108 (1950). McCrea, J. F., Biochem. J., 55, 132 (1953). Cohen, A., Lancet, 791 (1960). Low, R. J., and Baron, S., Science, 132, 622 (1960).

  5. 5

    Pumper, R. W., Science, 128, 363 (1958).

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    Pumper, R. W., Alfred, L. J., and Sackett, D. L., Nature, 185, 123 (1960).

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    Pumper, R. W., and Yamashiroya, H. M., Amer. J. Hyg., 72, 284 (1960).

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    Alfred, L. J., and Pumper, R. W., Proc. Soc. Exp. Biol. Med., 103, 688 (1960).

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  1. Department of Microbiology, College of Medicine, University of Illinois, Chicago



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