VOA慢速英语--脑疾病鉴定与预防进展

Progress Made in Identification, Prevention of Brain Diseases

Scientists are close to reaching a long-sought goal – a blood test to identify possible signs of Alzheimer’s and other diseases of the brain.

This comes as a recent large study shows healthy behavior can cut a person’s risk of developing such conditions, even if they have genes² that raise that risk.

At the Alzheimer’s Association International Conference on July 15, six research groups presented new results on several experimental tests. This included one that appears to be 88 percent accurate at identifying Alzheimer’s risk.

Doctors are hoping for something to use during regular exams that can measure most signs of brain-destroying diseases. They could make better decisions about which patients need additional testing. Current tools such as brain scans and spinal³ fluid tests are too costly⁴ or difficult to do during regular meetings with patients.

“We need something quicker … It doesn’t have to be perfect” to be useful, said Maria Carrillo, chief science officer for the Alzheimer’s Association.

Richard Hodes is director of the National Institute on Aging. He called the new results “very promising⁵.” He said blood tests soon will be used to choose and observe people for federally-supported studies.

“This has happened … far faster than any of us would have expected,” he told the Associated Press.

It cannot come too soon for patients like 66-year-old Tom Doyle. The former university professor from Chicago first experienced memory problems four years ago. He has had two spinal fluid tests since then.

First he was told he did not have Alzheimer’s. Later he was told that he did have it. Over time, doctors discovered Doyle suffered from different dementia-linked diseases — Lewy body and Parkinson’s.

“They probably could have diagnosed me years ago accurately⁶ if they had had a blood test,” said Doyle. He represents patients on the Alzheimer’s Association’s leadership team.

About 50 million people worldwide have the brain disease known as dementia. Alzheimer’s is the most common kind. There is no cure. Current medicines just temporarily ease its harmful effects. Many hoped-for treatments have failed. Doctors think past studies may have included people at too late a stage in the disease, when brain damage was already severe. The experts also say the research may have included too many people with problems other than Alzheimer’s.

A blood test — rather than subjective⁷ estimates of thinking skills — could get the right people into the right studies sooner.

One of the experimental blood tests measures unusual kinds of the protein that forms plaque⁸ in the brain. Plaque is a major sign of Alzheimer’s. Last year, Japanese researchers published a study of it. At the conference they gave results from additional testing on 201 people with Alzheimer’s or other types of dementia.

Akinori Nakamura is with the National Center for Geriatrics and Gerontology in Obu, Japan. He said the test correctly identified 92 percent of people who had Alzheimer’s and 85 percent who did not.

Another experimental test looks at neurofilament light, a protein that is a marker of nerve damage. Abdul Hye of King’s College London gave results of a study comparing blood levels in 2,300 people with several different brain diseases, including dementias, depression, Parkinson’s and multiple sclerosis. The study also included healthy people for comparison.

Eight of the diseases were linked to much higher levels of neurofilament light. The test cannot show which disorder⁹ someone might have. But it may help them rule out disorders¹⁰ in a patient.

Randall Bateman of Washington University School of Medicine in St. Louis also helped develop a blood test that measures the Alzheimer’s protein. His work is supported by the United States government and the Alzheimer’s Association.

“Everyone’s finding the same thing ... the results are remarkably¹¹ similar across countries, across techniques,” said Bateman. He estimates a test could be as close as three years away.

Recent progress in dealing¹² with conditions like Alzheimer’s has not been limited to treatment.

Researchers at the conference also presented a new study about prevention of these diseases. The study also appeared in the scientific publication the Journal of the American Medical Association.

It showed that people with high genetic¹³ risk and poor health habits were about three times more likely to develop dementia than those with low genetic risk and good habits. And, with any level of genetic risk, a good diet, regular exercise, limited alcohol use and no tobacco use made dementia less likely.

Elzbieta Kuzma and her team at the University of Exeter Medical School in England used the UK Biobank to study nearly 200,000 people age 60 or older with no signs of dementia. Subjects were identified as high, medium or low dementia risk based on genetic mutations. The study subjects were grouped also by lifestyle factors.

After about eight years of observation, 1.8 percent of those with high genetic risk and unhealthy behavior had developed dementia. A little over half of a percent of the people with low genetic risk and healthy habits had the disease.

John Haaga of the National Institute on Aging says the study results are good news.

“No one can guarantee you’ll escape this … disease” but clean living can improve your chances, Haaga said.

One limitation of the study is that researchers only had information on mutations affecting people of European ancestry¹⁴.

The results should ease fears that gene¹ mutations alone decide one’s brain health, said Rudy Tanzi, a genetics expert at Massachusetts General Hospital. Less than 5 percent of the mutations tied to Alzheimer’s are “fully penetrant,” meaning that they guarantee a person will get the disease, he said.

“That means that with 95 percent of the mutations, your lifestyle will make a difference,” Tanzi said. “Don’t be too worried about your genetics. Spend more time being mindful of living a healthy life.”

I’m Dorothy Gundy.

And I’m Pete Musto.

Words in This Story

accurate – adj. free from mistakes or errors

regular – adv. happening at times that are equally separated

scan(s) – n. the act or process of using a special machine to see the inside of something such as a part of the body

spinal – adj. of, relating to, or affecting the line of connected bones down the middle of the back

diagnose(d) – v. to recognize a disease or illness in someone

subjective – adj. based on feelings or opinions rather than facts

plaque – n. a change in brain tissue that occurs in Alzheimer's disease

habit(s) – n. a usual way of behaving

mutation(s) – n. a change in the genes of a plant or animal that causes physical characteristics that are different from what is normal

factor(s) – n. something that helps produce or influence a result

1 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

2 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

3 spinal   

adj.针的，尖刺的，尖刺状突起的；adj.脊骨的，脊髓的

参考例句：

• After three days in Japan,the spinal column becomes extraordinarily flexible.在日本三天，就已经使脊椎骨变得富有弹性了。
• Your spinal column is made up of 24 movable vertebrae.你的脊柱由24个活动的脊椎骨构成。

4 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

5 promising   

adj.有希望的，有前途的

参考例句：

• The results of the experiments are very promising.实验的结果充满了希望。
• We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。

6 accurately   

adv.准确地，精确地

参考例句：

• It is hard to hit the ball accurately.准确地击中球很难。
• Now scientists can forecast the weather accurately.现在科学家们能准确地预报天气。

7 subjective   

a.主观(上)的，个人的

参考例句：

• The way they interpreted their past was highly subjective. 他们解释其过去的方式太主观。
• A literary critic should not be too subjective in his approach. 文学评论家的看法不应太主观。

8 plaque   

n.饰板，匾，(医)血小板

参考例句：

• There is a commemorative plaque to the artist in the village hall.村公所里有一块纪念该艺术家的牌匾。
• Some Latin words were engraved on the plaque. 牌匾上刻着些拉丁文。

9 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

10 disorders   

n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调

参考例句：

• Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
• The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》

11 remarkably   

ad.不同寻常地，相当地

参考例句：

• I thought she was remarkably restrained in the circumstances. 我认为她在那种情况下非常克制。
• He made a remarkably swift recovery. 他康复得相当快。

12 dealing   

n.经商方法，待人态度

参考例句：

• This store has an excellent reputation for fair dealing.该商店因买卖公道而享有极高的声誉。
• His fair dealing earned our confidence.他的诚实的行为获得我们的信任。

13 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

14 ancestry   

n.祖先，家世

参考例句：

• Their ancestry settled the land in 1856.他们的祖辈1856年在这块土地上定居下来。
• He is an American of French ancestry.他是法国血统的美国人。