B. F. Elswood (1) and R. B. Stricker (2)(*)
(1) University of California, San Francisco, CA 94143, and
(2) California Pacific Medical Center, San Francisco, CA 94120
(*) Corresponding author
Submitted January 3, 1992, accepted February 2, 1993.
Reprinted from Research in Virology, vol. 144, 1993, pp. 175-177.