Health Highlights: Sept. 2, 2004 Here are some of the latest health and medical news developments, compiled by editors of HealthDay:    -----     Injuries Rampant in U.S., Study Says       Injuries kill 18 Americans each hour, a new government report says.       That figure translated into 157,000 people in 2001 alone, with no age group, gender, or race exempt, said the first national report for both fatal and nonfatal injuries released Thursday by the U.S...