The publisher of The Wall Street Journal filed suit this week to overturn a decades-long court order barring public access to a confidential Medicare database it says is essential to rooting out fraud and abuse in the government healthcare program. The American Medical Association, the doctors' trade group, successfully sued the government in 1979 to keep secret how much money individual doctors receive from Medicare, and the ruling still stands. The filing by Dow Jones & Co., in the U.S. District Court for the Middle District of Florida, comes after a series of articles in the Journal about abuses of the Medicare system. The articles were based on computerized Medicare records that represent part of the broader database at the center of the 1979 case.