1. Department of Pathology, School of Medicine, University of North Carolina, Chapel Hill, N.C. 27514, and the Division of Laboratories and Research, Department of Health, State of New York, Albany, N.Y. 12203.
2. School of Medicine, University of North Carolina, Chapel Hill, N.C. 27514.
3. Department of Pathology, School of Medicine, University of North Carolina, Chapel Hill, NC. 27514.
4. Division of Laboratories and Research, Department of Health, State of New York, Albany, N.Y. 12203.