美国国家公共电台 NPR New Markers For Alzheimer's Disease Could Aid Diagnosis And Speed Up Drug Development

 

RACHEL MARTIN, HOST:

Alzheimer's disease starts to change the brain long before any symptoms appear. So scientists are developing tests to actually detect these changes, and the tests are making diagnoses more accurate and drug treatments more effective. NPR's Jon Hamilton reports.

JON HAMILTON, BYLINE¹: The tests are known as biomarkers, and the first one hit the market in 2012. It's a dye called Amyvid that reveals clumps² of a protein called amyloid. These amyloid plaques³ are a hallmark of Alzheimer's. And Dr. Howard Fillit says before Amyvid came along, diagnosing the disease involved a lot of guesswork.

HOWARD FILLIT: So this test, which I can now send a patient down the block to the radiology office, and within 24 hours with 98% certainty, I can tell people if they have Alzheimer's disease. And so that's a biomarker.

HAMILTON: The test is expensive, though, and requires a brain scan. Also amyloid plaques are just one of the brain changes associated with Alzheimer's. So the Alzheimer's Drug Discovery Foundation, where Fillit is chief science officer, has launched an effort to speed up the development of biomarkers for other brain changes. Fillit says one promising⁴ marker reveals the presence of toxic⁵ proteins known as tangles⁶.

FILLIT: The tangles represent the dying neurons, and the main component⁷ of the tangles is this molecule⁸ called tau.

HAMILTON: Brain imaging can show tau tangles in patients who've been injected with a special dye. And several drug companies are competing to get a version of the dye approved by the Food and Drug Administration. Fillit says an approved test for tau would make it easier to evaluate new Alzheimer's drugs.

FILLIT: This tau imaging is going to be very important, not only diagnostically, but also for use in clinical trials as a biomarker for monitoring the efficacy of many drugs.

HAMILTON: But there's more to Alzheimer's than amyloid and tau. Fillit says people can have both and still do pretty well until something else shows up in the brain - inflammation.

FILLIT: It's like having the highest sensitivity computer up there and throwing coffee on it.

HAMILTON: So researchers are working on biomarkers for inflammation. And Fillit says there's even a biomarker that indicates the health of synapses⁹, the connections between brain cells.

FILLIT: We're funding a clinical trial at a company that is going to use this biomarker as a measure of how well their drug is preserving synapses in the hippocampus of people with Alzheimer's disease.

HAMILTON: Most biomarkers still require people to receive brain scans costing thousands of dollars. But Fillit says future tests are likely to use a sample of spinal¹⁰ fluid or blood and cost far less. Maria Carrillo is chief science officer at the Alzheimer's Association, which is a recent NPR sponsor. She says all of the new biomarkers will have to be tried in different populations.

MARIA CARRILLO: What may represent as a biomarker in one population may not actually hold true in another, and this is - we've seen this in other diseases.

HAMILTON: Also, biomarkers still don't offer doctors a reliable way to assess a person's memory or thinking. Even so, Carrillo says the tests have the potential to make Alzheimer's more like other diseases.

CARRILLO: We don't treat today, you know, a heart attack after it happens. We treat high cholesterol¹¹ to reduce the risk of that heart attack.

HAMILTON: Because cholesterol is a biomarker for heart disease. And Carrillo says, someday, doctors may be able to detect and treat high amyloid or tau or inflammation in the brain.

CARRILLO: For the future, we hope that we might be able to use these biomarkers in order to stop or delay the memory changes from ever happening. Our goal is to prevent dementia.

HAMILTON: In other words, stop Alzheimer's before it starts. Jon Hamilton, NPR News.

(SOUNDBITE OF PHAELEH'S "RED LIGHT GREEN LIGHT")

1 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

2 clumps   

n.（树、灌木、植物等的）丛、簇( clump的名词复数 )；（土、泥等）团；块；笨重的脚步声v.（树、灌木、植物等的）丛、簇( clump的第三人称单数 )；（土、泥等）团；块；笨重的脚步声

参考例句：

• These plants quickly form dense clumps. 这些植物很快形成了浓密的树丛。 来自《简明英汉词典》
• The bulbs were over. All that remained of them were clumps of brown leaves. 这些鳞茎死了，剩下的只是一丛丛的黃叶子。 来自《简明英汉词典》

3 plaques   

（纪念性的）匾牌( plaque的名词复数 )； 纪念匾； 牙斑； 空斑

参考例句：

• Primary plaques were detectable in 16 to 20 hours. 在16到20小时内可查出原发溶斑。
• The gondoliers wore green and white livery and silver plaques on their chests. 船夫们穿着白绿两色的制服，胸前别着银质徽章。

4 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。

5 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

6 tangles   

（使）缠结， （使）乱作一团( tangle的第三人称单数 )

参考例句：

• Long hair tangles easily. 长头发容易打结。
• Tangles like this still interrupted their intercourse. 像这类纠缠不清的误会仍然妨碍着他们的交情。

7 component   

n.组成部分，成分，元件；adj.组成的，合成的

参考例句：

• Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。
• Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。

8 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

9 synapses   

n.（神经元的）突触( synapse的名词复数 )；染色体结合( synapsis的名词复数 )；联会；突触；（神经元的）触处

参考例句：

• Nerve cells communicate with one another at the synapses, where their membranes almost touch. 神经细胞在突触部位彼此沟通，在这里它们的膜几乎接触到一起了。 来自辞典例句
• Glutamatergic synapses are common excitatory chemical connections in mammalian central nervous system. 谷氨酸性突触是哺乳动物神经系统的主要兴奋性突触。 来自互联网

10 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。

11 cholesterol   

n.（U）胆固醇

参考例句：

• There is cholesterol in the cell of body.人体细胞里有胆固醇。
• They are determining the serum-protein and cholesterol levels.他们正在测定血清蛋白和胆固醇的浓度。