1. From the Department of Biochemistry, University of Medicine and Dentistry of New Jersey–Rutgers Medical School, Piscataway, N.J., and the Department of Medical Biochemistry, University of Oulu, Oulu, Finland. Address reprint requests to Dr. Prockop at the Department of Biochemistry, University of Medicine and Dentistry of New Jersey–Rutgers Medical School, Piscataway, NJ 08854.