“…these are skin cells (Cochrum et al 1971, Levis & Miller 1972, Hirschberget al 1973, vascular endothelium (Hirschberg et al 1974 and spermatozoa (Levis et al 1974(Levis et al , 1975; in the dog, vascular endothelium (Vetto & Burger 1972) and kidney cells (Lifton et al 1977); in the rat, skin cells , kidney cells (Main et al 1975, Mashimo et al 1976), heart cells (Sakai et al 1977) and liver cells (Nishihira & Fujii 1972, Sakai et al 1978; and in the pig, kidney cells (Pawelec 1977) and liver cells .…”