The research reported here was done with my medical collaborators at New England Medical Center, Shapur Naimi, M. G. Criscitiello, Stephen Pauker, Greg Larsen, and in earlier years of the project, Robert Jayes and Steven Kurzrok. They are responsible for the medical content of the program, although any mistakes in this paper are my own. The work reported here has been supported by National Institutes of Health grants R01 HL 33041 from the National Heart, Lung, and Blood Institute and R01 LM 04493 from the National Library of Medicine.