More About Alzheimer's Disease

Scientists havedeveloped skin tests that may be used in the future to identify people withAlzheimer's disease and may ultimately allow physicians to predict who is atrisk of

getting thisneurological（神经病学的）disorder.

The only currentmeans of diagnosing the disease in a living patient is a long and expensiveseries of tests that eliminate every other cause of dementia.

"Since AloisAlzheimer described the disease nearly a century ago,people have been trying tofind a way to accurately diagnose it in its early stages,"said Patricia

Grady,actingdirector of the National Institute of Neurological Disorders and Stroke in Bethesda,Maryland."Thisdiscovery,if confirmed,could prove a big step forward in our

efforts to deal withand understand the disease."

Alzheimer's is thesingle greatest cause of mental deterioration in older people,affecting between2.5 million and 4 million people in the United States alone.The devastating

disorder graduallydestroys memory and the ability to function,and eventually causes death.Thereis currently no known treatment for the disease.

Researchersdiscovered that the skin cells of Alzheimer’s patients have defects thatinterfere with their ability to regulate the flow of potassium in and out ofthe cells.The fact

that the celldefects are present in the skin suggests that Alzheimer's results fromphysiological changes throughout the body,and that dementia may be the firstnoticeable

effect of thesechanges as the defects affect the cells in the brain,scientists said.

The flow ofpotassium is especially critical in cells responsible for memory formation.Thescientists also found two other defects that affect the cells'supply of

calcium,anothercritical element.

One test developedby researches calls for growing skin cells in a laboratory culture and thentesting them with an electrical detector to determine if the microscopictunnels

that govern the flowof potassium are open.Open potassium channels create a unique electricalsignature.

A spokesman for theAlzheimer's Association said that if the validity of the diagnostic test can beproven it would be an important development,but he cautioned that other

promising tests forAlzheimer's have been disappointing.

Which of thefollowing statements about the Alzheimer's disease is NOT true?

A.It was so namedbecause Alois Alzheimer first described it.

B.It is the greatestcause of mental deterioration in older people.

C.It can graduallydestroy memory and eventually cause death.

D.There are manyways to deal with and cure the disease now.