OSLO, Norway - Dr. D. Carleton Gajdusek, a Nobel Prize-winning American medical researcher who studied brain diseases and infections that lie dormant for years - such as mad-cow - before attacking the body, has died. He was 85.

His biographer, Dr. Robert Klitzman of Columbia University in New York, said Gajdusek was found dead Dec. 12. at a hotel in Tromsoe, Norway, where the laureate spent several months a year.

His research triumphs were marred by a child molestation case when, in 1997, he pleaded guilty to molesting a teenage boy, one of dozens of children he had brought from the Pacific islands to live with him in Middletown, Md. *

-Associated Press