1.   Arimidex, a nonsteroidal drug, blocks the enzyme the body needs to convert other hormones into estrogen.

2.   Both drugs block an enzyme, reverse transcriptase, that the virus needs to reproduce.

3.   But some researchers say a component of garlic may block enzymes associated with infection.

4.   For men who suffer from impotence, Viagra blocks an enzyme that breaks down a naturally occurring substance that causes erections, Sabanegh said.

5.   Glucosamine in its natural form stimulates cells that make cartilage, while chondroitin sulfate blocks enzymes that break down old cartilage.

6.   He realized that the drug just might be blocking an enzyme that kicks in and makes an erect penis go flaccid.

7.   In theory, it makes little sense that blocking this enzyme should prevent cancer.

8.   It may also block an enzyme that helps infections spread.

9.   Now drugs giant GlaxoSmithKline is looking for compounds to block the enzyme.

10.   Orlistat works in the gastrointestinal tract, blocking an enzyme that is needed to digest fat.