(Portland, OR)  --  Portland police are looking for a missing 62-year-old man who has medical problems.  Authorities say Reginald Dean Lewis hasn't been seen since three o'clock yesterday afternoon after he went to the VA Hospital in Portland for an appointment.  Officials say Lewis's medical problems could be life-threatening if they aren't addressed.  Lewis is described as African-American, five-feet-seven, weighing 180 pounds, and was last seen wearing a dark-gray matching sweatsuit and may be wearing glasses.