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More About Alzheimer' s Disease
Scientists have developed skin tests that may be used in the future to identify people with Alzheimer's
disease and may ultimately allow physicians to predict who is at risk of getting this neurological
（神经病学的）disorder.
The only current means of diagnosing the disease in a living patient is a long and expensive series of
tests that eliminate every other cause of dementia.
"Since Alois Alzheimer described the disease nearly a century ago,people have been trying to find a
way to accurately diagnose it in its early stages,"said Patricia Grady,acting director of the National Institute
of Neurological Disorders and Stroke in Bethesda,Maryland."This discovery,if confirmed,could prove a big
step forward in our efforts to deal with and understand the disease."
Alzheimer's is the single greatest cause of mental deterioration in older people,affecting between 2.5
million and 4 million people in the United States alone.The devastating disorder gradually destroys memory and
the ability to function,and eventually causes death. There is currently no known treatment for the disease.
Researchers discovered that the skin cells of Alzheimer's patients have defects that interfere with their
ability to regulate the flow of potassium in and out of the cells.The fact that the cell defects are present in the
skin suggests that Alzheimer's results from physiological changes throughout the body,and that dementia may
be the first noticeable effect of these changes as the defects affect the cells in the brain,scientists said.
The flow of potassium is especially critical in cells responsible for memory formation.The scientists also
found two other defects that affect the cells' supply of calcium,another critical element.
One test developed by researches calls for growing skin cells in a laboratory culture and then testing
them with an electrical detector to determine if the microscopic tunnels that govern the flow of potassium are
open.Open potassium channels create a unique electrical signature.
A spokesman for the Alzheimer's Association said that if the validity of the diagnostic test can be
proven it would be an important development,but he cautioned that other promising tests for Alzheimer's
have been disappointing.
The passage indicates that Alzheimer's is a disease________.
A:common to people,old and young
B:not costly to be cured
C:easy to be handled
D:not easy to be diagnosed