21.   A German group, whose report appears today in the American Heart Association journal Circulation, represents the first published study showing new blood vessel growth in human hearts.

22.   Alarmed, the White House recently commissioned six teams of scientists to begin the first large-scale study of the area, hoping for a remission or cure.

23.   But according to the first studies of gender switching on the Internet, everyone probably has a pretty good idea of what kind of dog you are.

24.   But Auerbach and several colleagues took a huge leap forward with the first meticulous studies of damage in humans.

25.   But even as the first large-scale studies of benefits of genetically modified plants appear, more questions than answers remain.

26.   But no one had tested this hypothesis until September, when researchers completed the first study to compare breast cancer risk factors of lesbian and heterosexual women.

27.   But on Tuesday, the first published clinical study of leptin finds that the substance is not the weight loss panacea that obesity researchers had hoped for.

28.   But others said they were important because this was the first long-term study to link violent behavior and television watching by teen-agers and young adults.

29.   But the government is taking the issue seriously enough to solicit the first studies to validate crime-scene print identification and set standard procedures for examinations.

30.   But Tuesday, the first published clinical study of leptin finds that the substance is not the weight loss panacea that obesity researchers had hoped for.