U.S. consumer prices gain slightly; underlying inflation tame

WASHINGTON (Reuters) - U.S. consumer prices rose slightly in December even as households paid more for healthcare, and monthly underlying inflation slowed, supporting the Federal Reserve's desire to keep interest rates unchanged at least through this year.The weak inflation report from the Labor Department on Tuesday came on the heels of data last week showing a moderation in job growth in December. Economists said these developments were flagging a sharp slowdown in domestic demand. Though the..