1. Neurosurgery, Rockville, Maryland, U.S.A.
2. Neurosurgery Department, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Rockville, Maryland, U.S.A.
3. Neurology Departments, University of Pennsylvania, Rockville, Maryland, U.S.A.
4. Laboratory of Metabolism and Molecular Biology, National Institute on Alcohol Abuse and Alcoholism, Rockville, Maryland, U.S.A.