The U.S. dollar gained against the Japanese yen today, passing the crucial 100-yen mark, rising to 101.55 in late New York trading . . . Dow Jones industrial average up 6.79 points, closing at 3,753.81 . . . N.Y.S.E.'s composite index rose 0.45 to 252.99 . . . NASDAQ stock gained 1.25 to 719.92 . . . American Stock Exchange up 1.26 to 441.60 . . . Gold lost $0.60 to $376.70 on the Commodity Exchange in New York . . . The 30-year Treasury bond closed with a yield of 7.52 percent, down from 7.54 late Friday.