Nikkei ended slightly higher Thursday as investors were heartened by the Bank of Japan\'s upgraded assessment of the Japanese economy, as well as by firmer Asian stocks. The 225-issue Nikkei Stock Average ended up 55.98 points, or 0. 39 percent, from Wednesday at 14,472.58. The broader Topix index of all First Section issues on the Tokyo Stock Exchange was down 0.43 point, or 0.04 percent, at 1, 194.77. Gainers were led by real estate, mining and glass firms while decliners included paper, electric machinery and insurance issues. The turnover was about 2,230.5 billion yen (around 22.44 billion U.S. dollars).