11.   Critics say the US government is too cautious about human AIDS vaccine experiments, preferring to concentrate on more test tube research first.

12.   Generally in approving a human experiment, the FDA is concerned about the risk to the participants.

13.   However, implementing the rules governing human experiments done with federal money is already immensely complicated.

14.   Hyman said he is taking steps to assure that the riskiest of the human experiments are scrutinized more closely.

15.   In recent years, more than just the number of human experiments has increased.

16.   Ironically, experts say, the debate over ethics in human experiments is occurring at a time when medical research is safer than it has ever been.

17.   Now the first tests from human experiments are coming in, and they show success as well, the researchers say.

18.   On Thursday, Duke officials met in Maryland with officials of the agency charged with overseeing the safety of patients in human experiments around the nation.

19.   Review boards vary in their willingness to approve human experiments.

20.   Seed dismissed the potential dangers to embryos or fetuses resulting from human cloning experiments.