Technicians carve out nickel-size sections from the brain stem medulla.
They chill them, bake them and treat them with a series of chemicals. While more than 180,000 cases of mad cow disease have been diagnosed in Great Britain since 1984, no case has been detected yet in the United States. That may be luck. It may be because of that moat known as the Atlantic Ocean. Still, scientists note that what was for years just a British disaster has in recent months sent panic across Europe.