A South-Central Los Angeles man who is accused of sexually assaulting a 26-year-old woman while both were patients at County-USC Medical Center's psychiatric ward pleaded not guilty to two counts of rape stemming from the alleged incident. Further investigation is being done to see whether Ben Jude Lezine, 31, who is believed to have acquired immune deficiency syndrome, also intended to kill his victim, Deputy Dist. Atty. Penny Schneider said. If prosecutors can establish "an express intent to kill," Lezine could be charged with attempted murder, Schneider said.