1413-6538 1413-6538 S1413-65382014000400591 /10.1590/S1413-65382014000400010 00 12 2014 00 12 2014 20 4 591 604

22 35 35 299-328 2 22 22 45-59 17 3 3 413-26 1 3-14 24 41 41 467-82 27 1 1 75-131 13 3 3 399-414