PHILADELPHIA -- Any changes in your medications or allergies? Check. New health issues since your last visit? Check. And would you like to contribute a blood and DNA sample for a massive research project? That last question is now part of the electronic check-in process for patients at Penn Medicine clinics and hospitals, and it already is yielding promising clues in the study of disease. More than 260,000 people have signed up to participate in the project, called Penn Medicine BioBank, agreeing to have their samples stored in secure freezers set to negative 80 degrees Celsius. By cross-refer...