SALT LAKE CITY — Gene Fullmer, a former middleweight boxing champion and member of the International Boxing Hall of Fame whose 55 career victories included two wins over Sugar Ray Robinson, has died, his nephew said Tuesday. He was 83. Fullmer suffered from Alzheimer’s disease and dementia for years and died Monday while fighting a bacterial infection, his nephew Larry Fullmer said. Fullmer turned professional in 1951 and defeated Robinson in 1957 to win the middleweight title. Fullmer lost the title in a rematch with Robinson, but regained the vacated title in 1959 by beating Carmen Basilio and defended it seven times. He retired in 1963 with a 55-6-3 record. — Reuters