Tokyo, April 23 (BridgeNews) - Japanese shares had opened higher in a positive reaction to news that former health and welfare minister Junichiro Koizumi was likely to win the LDP presidential election to replace Prime Minster Yoshiro Mori. However, the market soon gave up early gains on uncertainty over Koizumi's political measures and the new cabinet line-up, traders said. The Nikkei fell 0.7%, or 96.46 points to close the morning at 13,669.21.