Beth Israel Deaconess Physician Organization (BIDPO) has executed an 8,442 s/f lease at 400 Blue Hill Dr., relocating from Renaissance Park. Senior vice president Kristin Blount and associate William Lynch of Colliers Meredith & Grew represented BIDPO.  First vice president Nathanael Kessler of CB Richard Ellis - New England represented the landlord Cornerstone Corp.    Built in 1980, 400 Blue Hill Dr. is a three-story, 100,000 s/f office building. The building is near the University Ave./Rte. 128 interchange. "After reviewing various Boston and suburban options, 400 Blue Hill Dr. was the best solution for BIDPO" said Lynch.