So telomere-related research isn't the only avenue Effros and her colleagues are exploring. They have also discovered that a certain molecule called CD28 disappears from the surface of T-cells when they reach replicative senescence. This happens not only in cell culture, but also in T-cells isolated from the blood of elderly people (as well as younger people infected with the virus that causes AIDS). CD28 is unique  to T-cells,    and a signal from CD28 is essential if the cell is to mount a defense against a foreign invader, such as the flu virus. Effros believes that this finding could be developed into a test for "immunological age"; by measuring the proportion of T-cells that no longer have CD28 on their surface, Effros hopes to determine which of us are more at risk for infections. She has recently been granted a patent for this novel approach.

 

The Hidden Destroyer

 

lzheimer's disease is one of the scourges of old age, a mysterious malady with no known cause, seemingly lying in wait to strike down the unsuspecting elderly. Even worse, there's no good test to diagnose the disease in its early stages. And early diagnosis is vital. "There is no cure currently," acknowledges Gary Small, professor of psychiatry and biobehavioral sciences and director of the UCLA Center on Aging. "But there are two drugs available for Alzheimer's, and there are several others that will soon be approved that have some effect on many patients. They can be equivalent to delaying progression of the disease for six months to a year." A relatively small step forward? Yes. But one that could have enormous consequences, since by some estimates, Alzheimer's disease strikes up to 10 percent of everyone older than 65 and 47 percent Photograph by KLAUS SCHOENWIESE  of everyone older than 85. Moreover, in the U.S. it is estimated that the direct and indirect costs of Alzheimer's approaches a staggering $100 billion annually. And these costs are expected to soar as the mass of baby boomers reaches old age. Early detection of the disease could not only extend the quality of life for millions, but save billions of dollars. Small has devoted his professional life to solving the riddle of Alzheimer's. A graduate of UCLA, he received his M.D. from the University of Southern California in 1977 and completed his residency at Massachusetts General Hospital. He returned to UCLA in 1981 on a fellowship and was soon appointed assistant professor of psychiatry and biobehavioral sciences. Recently confirmed director of the Center on Aging, Small has continued to focus his research on refining the diagnostic accuracy for all major forms of geriatric psychopathology, especially Alzheimer's disease. His hope is to facilitate anti-dementia treatments in patients at risk long before brain damage develops. Supported by the National Institute of Mental Health, the National Institute on Aging, the Alzheimer's Association, Montgomery Street Foundation and the Fran and Ray Stark Foundation Fund for Alzheimer's Disease Research, Small and his colleagues are taking several approaches to the early detection of Alzheimer's, all using modern brain-imaging techniques. All also take into account one of the most exciting recent findings about the cause of Alzheimer's disease: the discovery by former Duke University researcher Allen D. Roses and his colleagues that people with Alzheimer's are much more likely to have inherited a certain gene