Some hospital workers at UPMC are planning to strike Thursday as part of a nationwide walk-out by fast-food and others workers for a $15-an-hour minimum wage. The Service Employees International Union Healthcare PA said in a news release Wednesday that an unspecified number of UPMC health care workers "from every Pittsburgh hospital and in every job type" would strike for union rights and against UPMC's tactics in fighting union representation. Fight For $15 will hold a series of strikes nationwide,…