The U.S. Department of Justice has been asked to conduct an investigation into Chronicle stories detailing grand jury testimony in the baseball steroids case, the Chronicle reports. “Violations of grand jury secrecy rules will not be tolerated,” said Kevin Ryan, head of the U.S. attorney’s office in San Francisco. The request followed a Chronicle story Thursday revealing testimony by New York Yankee Jason Giambi that he had injected himself with human growth hormone during the 2003 baseball season and had begun using steroids at least two years before then.