Tokyo stocks opened higher Tuesday on bargain-hunting following sharp declines the previous day, but the gains were limited by an overnight fall of the U.S. Dow Jones index. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average rose 88.15 points, or 0.22 percent, from Monday to 39,891.24. The broader Topix index was up 3.21 points, or 0.12 percent, at 2,724.43. On the top-tier Prime Market, gainers were led by insurance, iron and steel, and oil and coal product issues. At 9 a.m., the U.S. dollar fetched 151.58-59 yen compared with 151.59-69 yen in New York and 151.34-35 yen in…