Nikkei gains on Wall St rally, investors cautious ahead of earnings

* Nikkei up 0.7 pct, but still below previous day's high * Investors look to earning reports * Some buying low P/E names such as Bridgestone gain * Seibu Holdings open steady at IPO prices By Hideyuki Sano TOKYO, April 23 (Reuters) - Japanese stocks rose on Wednesday morning, spurred by Wall Street gains on solid earnings and merger activity, but buying was tempered as investors were wary of the looming local reporting season. The Nikkei rose 0.7 percent to 14,495.44, e