The Providers and Sta# of Medical Associates of Greater Boston. 307 West Central Street Wendy J. Parker, M.D. Natick, MA 01760 Deborah J. Riester, M.D. Telephone: 508-820-8383 Jo-Ann Suna,M.D. ... For Gateway Patient Portal Use (Online access to request appointments, refills, receive lab results, etc. For information how to sign-up, please ....