VOA标准英语2011--MRI Sees Brain Atrophy Years Before Alzh

MRI Sees Brain Atrophy¹ Years Before Alzheimer's Symptoms

Memory loss and mental confusion are the first overt² signs of Alzheimer's Disease, an incurable³ and fatal brain ailment⁴.
But scientists are starting to find evidence of the disease long before symptoms appear. In the latest research, MRI scans show telltale signs in the brain a decade before memory and thinking are affected⁵.
The pace of research aimed at understanding and preventing or treating Alzheimer's has been frustratingly⁶ slow.
A number of medicines have reached the market in recent years, but at best they only slow the progression of the disease.
Some researchers think that drugs may be more effective if they're given sooner, before symptoms become apparent.
A researcher at Harvard Medical School, Bradford Dickerson, is exploring an imaging technique that can identify characteristics of the brain that might signal the mental decline to come years later.
"So we wanted to test MRI, which is something that we think would potentially be more accessible to people if we end up needing to screen large groups of older subjects for these kinds of changes," Dickerson says.
In a new study, Dickerson and his colleagues studied a group of men and women starting when they were in their 70s. At the outset, they were given standard tests, and all of them showed normal memory and mental function. They also got an MRI scan of the brain.
Around 10 years later, the participants - now in their 80s - were again tested, and now about one out of four showed symptoms of Alzheimer's.
Going back to the MRI results from a decade or so earlier, the researchers found differences between the group who still had normal memory and those who were cognitively⁷ impaired⁸, differences in Alzheimer's-related parts of the brain.
"And it turned out that those areas of the brain were, in subtle ways, smaller in the people who were cognitively normal but over the next eight years or so eventually developed Alzheimer's dementia than the same areas in the brains of people who remained cognitively normal over that period of time."
For now, this is just a research finding, but Dickerson sees a time in the not-too-distant future when doctors will tell people of a certain age with no symptoms that it's time to get tested for Alzheimer's.
"I believe that at some point in the next decade or so, we're going to see tests being proposed to be used as screening tools, sort of like colonoscopies are used," Dickerson says. "So that once you get past a certain age, you would undergo this screening test. And I think this MRI method has at least some plausibility⁹ to be one of those kinds of screening tools."
And the hope is that drugs in use now or yet to be developed will make a significant difference when taken before memory and mental function begin to decline.

1 atrophy   

n./v.萎缩，虚脱，衰退

参考例句：

• Patients exercised their atrophied limbs in the swimming pool.病人们在泳池里锻炼萎缩的四肢。
• Many hoped he would renew the country's atrophied political system.很多人都期望他能使该国萎靡的政治体系振作起来。

2 overt   

adj.公开的，明显的，公然的

参考例句：

• His opponent's intention is quite overt.他的对手的意图很明显。
• We should learn to fight with enemy in an overt and covert way.我们应学会同敌人做公开和隐蔽的斗争。

3 incurable   

adj.不能医治的，不能矫正的，无救的；n.不治的病人，无救的人

参考例句：

• All three babies were born with an incurable heart condition.三个婴儿都有不可治瘉的先天性心脏病。
• He has an incurable and widespread nepotism.他们有不可救药的，到处蔓延的裙带主义。

4 ailment   

n.疾病，小病

参考例句：

• I don't have even the slightest ailment.我什么毛病也没有。
• He got timely treatment for his ailment.他的病得到了及时治疗。

5 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

6 frustratingly   

参考例句：

• Some programs set this limit too close, resulting in frustratingly temperamental scroll behavior. 一些程序将这种限制设置得太窄，导致滚屏的行为变幻无常，令人沮丧。 来自About Face 3交互设计精髓
• But the process is frustratingly slow. 但这过程慢得让人郁闷。 来自互联网

7 cognitively   

参考例句：

• Cognitively,man,the subject of cognition,must classify and categorize the objects. 从认知学角度来看 ，作为认知主体的人对于认知对象必须进行分类和范畴化。 来自互联网
• Cognitively, reference can be studied along with information processing of human mind. 从认知的角度看，要研究人类思维的信息处理过程。 来自互联网

8 impaired   

adj.受损的；出毛病的；有（身体或智力）缺陷的v.损害，削弱( impair的过去式和过去分词 )

参考例句：

• Much reading has impaired his vision. 大量读书损害了他的视力。 来自《现代汉英综合大词典》
• His hearing is somewhat impaired. 他的听觉已受到一定程度的损害。 来自《现代汉英综合大词典》

9 plausibility   

n. 似有道理, 能言善辩

参考例句：

• We can add further plausibility to the above argument. 我们可以在上述论据之外，再进一步增添一个合理的论据。
• Let us consider the charges she faces, and the legal plausibility of those charges. 让我们考虑一下她面临的指控以及这些指控在法律上的可信性。