Date: Fri 23-Apr-1999

Publication: Hea

Author: CURT

Quick Words:

Enzyme-Alzheimer's-Monitor

Full Text:

HEALTH MONITOR: Scientists Hunt Key Enzyme For Alzheimer's

By Jeff Donn

Associated Press

In what could be a key step in finding a treatment for Alzheimer's,

researchers reported today that they have found an enzyme that activates the

mind-robbing disease afflicting some four million Americans.

One of the researchers, Dr Dennis Selkoe, a neurologist at Brigham and Women's

Hospital in Boston, said scientists are "very much on the road" to a

treatment. He said drugs designed to block the enzyme could enter clinical

trials within three years.

But some scientists questioned whether the research team had identified the

actual enzyme or one that simply works in concert with it.

"The case is far from nailed either way," said John Hardy of the Mayo Clinic.

Alzheimer's patients are known to have toxic plaques, or buildups, of amyloid

beta proteins in their brains.

Selkoe, Michael Wolfe at the University of Tennessee and others found evidence

suggesting that a previously known brain substance called presenilin is the

enzyme that controls production of amyloid beta proteins. Scientists

previously believed presenilin played a role in Alzheimer's.

Dr Sam Gandy, a New York University cell biologist who works with amyloid

proteins, said the study published in the journal Nature offers "very exciting

and persuasive evidence."

But he cautioned that the enzyme and the chemical on which it operates must be

purified and allowed to interact alone to be certain other unseen chemicals

are not involved.

Researchers also warned that presenilin may regulate other processes, such as

the immune system, meaning that Alzheimer's drugs designed to inhibit

presenilin could carry unwanted side effects.