1.   Killing the adult ticks will interrupt the reproduction cycle, scientists said.

2.   The reverse transcriptase inhibitors work by blocking the action of an enzyme known as reverse transcriptase, used by HIV early in its reproduction cycle.

3.   They work by blocking the action of an enzyme known as reverse transcriptase, used by HIV early in its reproduction cycle.

4.   Called nucleoside analogs, they work by blocking a protein active in the early reproduction cycle of the virus, but the virus quickly develops resistance to their effect.

5.   Eventually, he said, a fish population becomes so short of spawners that mates are scarce and the whole reproduction cycle of a species is disrupted.

6.   Like the drug AZT, it acts in the early reproduction cycle of the AIDS virus.

7.   The drug is saquinavir, a compound that attacks the reproduction cycle of the AIDS virus in a way different from that of drugs now in use.