Dr. Matt Narrett of Ellicott City has been named executive vice president and chief medical officer of Erickson Retirement Communities, a geriatric health care company based in Baltimore.

Dr. Roy Thomas Smoot Jr. has joined Maryland General Hospital as chief medical officer. Smoot is a fellow in the American College of Surgeons.

Dr. Carol Greider, professor and director of molecular biology and genetics in the Johns Hopkins Institute of Basic Biomedical Sciences, has been awarded the 2007 Horwitz Prize along with two other researchers. The recipients are being honored for their work on telomeres, the structures capping the ends of chromosomes.