Tokyo stocks ended lower Thursday, as pockets of dip-buying eventually gave way to selling amid lingering concern over the U.S. economy and market volatility. The 225-issue Nikkei Stock Average ended down 258.47 points, or 0.74 percent, from Wednesday at 34,831.15. The broader Topix index finished 27.51 points, or 1.11 percent, lower at 2,461.70. On the top-tier Prime Market, decliners were led by nonferrous metal, metal product and bank shares. The U.S. dollar briefly fell to the mid-145 yen range in Tokyo as the Japanese currency was bought after a summary of opinions at the Bank of Japan’s …