GLOBAL MARKETS- Bank tests comfort investors but growth worries persist

* Investors return to risk after ECB health checks* European shares reverse gains on weak Ifo data* Italy&aposs Monte Paschi drags down bank share index* Brazil markets set for losses after Rousseff election win* Russian stocks rebound, rating downgrade avertedBy John GeddieLONDON, Oct 27 (Reuters) - Low-rated government bond yields dropped and the euro edged tentatively higher on Monday as the re