Stocks little changed with eyes on Greece; oil off

By Rodrigo Campos NEW YORK (Reuters) - A Supreme Court ruling upholding tax subsidies boosted some U.S. healthcare stocks to fresh highs on Thursday, while key global equity markets were little changed following a proposal by Greece's creditors to avoid a Greek debt default. Greece's international creditors presented a cash-for-reform proposal to euro zone finance ministers in a showdown with Athens, after negotiations failed to yield a plan to avert a default. On Wall Street, hospital