Edward Miller, M D, who has overseen a vast expansion of Johns Hopkins Medicine -- on Baltimore's east side and in countries around the world -- since taking over as dean and chief executive in 1997, said Thursday that he will retire next year. Miller, 68, has built a medical powerhouse, with six hospitals, including All Children's Hospital in Florida, several suburban health care and surgery centers, and more than 30 primary and specialty health care facilities -- many of which he helped bring into the fold. He has also established a network of partnerships with hospitals in Asia, the Middle East and Latin America. In one of its latest moves, Johns Hopkins Medicine signed an agreement in November to open the first private, four-year medical school and teaching hospital in Malaysia.