Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032
Received April 12, 2000. Revision received October 9, 2000. Accepted October 18, 2000.
Address all correspondence and requests for reprints to: Dr. Elizabeth Shane, Department of Medicine, Columbia University College of Physicians and Surgeons, 630 West 168th Street, New York, New York 10032
