1. Bartholin Instituttet (K.J., K.B., L.R.S., M.W.), Kommunehospitalet, DK-1399 Copenhagen K, Denmark;
2. Department of Clinical Neuroscience (R.E.), Göteborg Universitet, Mölndal Hospital, S431-80 Sweden;
3. Kovler Viral Oncology Laboratory (M.B.), University of Chicago, Chicago, Illinois 60637