The hundreds of medical marijuana dispensaries in Michigan are being advised to stay closed indefinitely, legal experts said Thursday in the wake of a major appeals court ruling. The ruling, handed down Wednesday, banned medical marijuana sales at a facility in Mount Pleasant. It prompted the estimated 400 to 500 dispensaries in Michigan to shut down and outraged the nearly 100,000 carriers of medical marijuana cards. “They have to stay closed until further notice,” said Paul Tylenda, a Grosse Pointe Park lawyer. “If they open, they are at risk of getting treated like criminals.” It is unclear when, if ever, any move will change the court’s interpretation of the 2008 medical marijuana law.