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Strategies & Market Trends : Rande Is . . . HOME -- Ignore unavailable to you. Want to Upgrade?

To: JLS who wrote (32310)	8/17/2000 9:11:33 AM
From: johnsto1	Read Replies (1) \| Respond to of 57584

N.Y.Times...Genomics August 17, 2000 Brain Study Finds Early Signs of Alzheimer's By REUTERS -------------------------------------------------------------------------------- Related Article • Health: Aging Forum • Join a Discussion on Aging -------------------------------------------------------------------------------- OSTON -- Scientists have found fresh evidence that the brains of those destined to develop Alzheimer's disease are forced to work harder to perform various tasks long before any obvious symptoms of the memory-robbing disease appear, according to a new study. In tests on 30 volunteers ages 47 to 82, University of California at Los Angeles researcher Susan Bookheimer and her colleagues said they discovered that people whose genetic makeup includes APOE4, a snippet of DNA often found in people with Alzheimer's, utilize a larger portion of the brain to perform a given job than people with APOE3, the normal form. The study was published in Thursday's New England Journal of Medicine. "The average signal intensity detected by magnetic resonance imaging (MRI) was nearly twice as great among the carriers of the APOE4 allele as among carriers of the APOE3 allele," the researchers said. Volunteers who had trouble processing information also tended to have poorer memories when the group was retested two years later. Two of the volunteers in the APOE4 group were subsequently diagnosed with Alzheimer's. "We now know there are brain changes occurring early on" that predict mental deterioration, Bookheimer told Reuters in a telephone interview. "It gives us hope that we can narrow this down on an individual level and we can intervene," perhaps slowing or reversing the progress of the disease, Bookheimer added. If nothing else, the technique could lead to a better way of identifying drugs that slow the deterioration. Asked if a combination of MRI testing and genetic screening could provide an early-warning test for the disease, Bookheimer said, "Ultimately I hope so. But right now it's much more preliminary than that." In an accompanying editorial in the New England Journal of Medicine, Dr. Ingmar Skoog of Sahlgrenska University Hospital in Goteborg, Sweden, said the study "suggests that carriers of the APOE4 allele need to use more brain resources than do non-carriers to perform the same task." Bookheimer and her team were observing brains trying to overcompensate for the damage possibly caused by Alzheimer's, which affects 8 percent of people 65 and older. No Early Alzheimer's Test Seen The findings do not mean an early test for Alzheimer's is on the horizon, said Skoog, because the disease never develops in many people with the APOE4. Bookheimer agreed. "It's not a perfect predictor. We know there is more than one cause. But if you have the epsilon 4 allele, your risk of getting the disease is much greater." Everyone has two copies of APOE. Previous research has shown that people with two copies of APOE4 have a 91 percent chance of eventually developing Alzheimer's. The rate is 20 percent when people have two copies of APOE3 and 47 percent among those with one copy of each form, said Bookheimer. The APOE gene also affects when Alzheimer's appears. The average age of onset is 68 years in people with two copies of APOE4, 75 years with one copy, and 84 if they have no APOE4 genes. Bookheimer said the volunteers in the study have not been told whether they have the DNA that increases their risk of Alzheimer's. "Our human subjects insist that they not be told of their genetic status," she said. "It's not a perfect predictor, so it's not fair to do that."