The New York Times is reporting an influential federal panel of medical advisers has recommended that the government allow pharmaceutical companies to begin conducting tests on prison inmates. The practice was all but stopped three decades ago after revelations of abuse. Until the early 1970’s, about 90 percent of all pharmaceutical products were tested on prison inmates. But such research diminished sharply in 1974 after revelations of abuse. At the Holmesburg prison in Philadelphia, inmates were paid hundreds of dollars a month to test items as varied as dandruff treatments and dioxins. They were exposed to radioactive, hallucinogenic and carcinogenic chemicals.