Contents: Neurology Epidemiology Health Policy Research Briefs Bulletin Forum

NEUROLOGY Unmasking Elusive Enzyme Reveals Known Villain Dennis Selkoe (far right) and colleagues In recent years, two discoveries have set the field of Alzheimer's research abuzz: one, that a gene called presenilin underlies the most aggressive form of the disease, and two, that erosion of the mind probably starts with production of the peptide amyloid-beta (A-beta) by an elusive enzyme. Since these discoveries were made, scientists have focused on two apparently separate questions central to understanding the origin of the disease: what does the presenilin protein do? And what is this enzyme? FULL STORY EPIDEMIOLOGY: Cancer Risk May Be Higher for Young Smokers HEALTH POLICY: Use of Hormone Replacement Therapy Not Determined by Clinical Factors HMS has a new on-line magazine, WebWeekly, covering research, hospital-news releases, events in-depth, student life, and more. The URL is www.hms.harvard.edu/webweekly. Let us know what you think.