[1] Bayer Res Ctr, Dept Virol, Wuppertal, Germany
[2] Bayer Res Ctr, Chem, Wuppertal, Germany
[3] Bayer Res Ctr, Isotope Chem, Wuppertal, Germany
[4] Bayer Res Ctr, Preclin Pharmakokinet, Wuppertal, Germany
[5] Bayer Res Ctr, Toxicol, Wuppertal, Germany
[6] Bayer Res Ctr, Safety Pharmacol, Wuppertal, Germany
[7] Deutsch Krebsforschungszentrum, D-6900 Heidelberg, Germany
[8] Bayer Corp, Div Pharmaceut, West Haven, CT 06516 USA