VOA标准英语2010年-New Stroke Treatment Shows Promise in

Researchers in California are showing some promising¹ results with a new approach to treating stroke. The scientists are focusing on getting undamaged parts of the brain to take over functions impaired² by the stroke.
In a stroke, a loss of blood supply — from a clot³, for example — can starve brain tissue of oxygen, and brain cells die.
Each part of the brain is hard-wired for certain functions. One part interprets vision, for example; another moves the left hand. But if undamaged regions can take over the role of the brain cells killed off in the stroke, then patients might regain⁴ lost functions.
Thomas Carmichael of the University of California Los Angeles explains that the brain can do that itself, in a limited way.
"The tissue around the damaged region can take over some of the function that was lost," he said in a telephone interview. "For example, if the region that was lost moved the arm, a portion of the brain that, say, normally moves the face — which is adjacent to the arm region — can take over some arm movement."Carmichael and his colleagues have been trying to figure out how to improve the process.
Using laboratory mice, the scientists induced a stroke in the animals' forelimbs.
"And the rest of the forelimb-movement area [of their brains] is supposed to kick into gear and take over function," Carmichael said. "And what we found is this tissue that was supposed to kick into gear was instead over-inhibited because it had an accumulation of this inhibitory molecule⁵, GABA."GABA helps regulate the body's muscle tone, but it also inhibits⁶ brain cells from taking on any new functions. So the researchers gave the mice drugs designed to counter the effect of GABA. The result was a significant gain of function in the forelimbs affected⁷ by the stroke. But the scientists found that timing⁸ was critical.
"And what we found is, you can give these chemicals beginning, in the mouse, three days after stroke. But if you give them earlier, you actually make the stroke worse."They got the best results when the treatment was continued for 30 days.
As Carmichael and his colleagues continue their research, one thing they'll be looking at is whether this kind of treatment would work for strokes affecting any part of the brain.
"We know that this therapy works in strokes that occur in the cortex — one part of the brain — as well as in the basal ganglia, a second part of the brain. And so far it looks like this therapy will work with strokes in many different parts of the brain," Carmichael said.
There's a long way to go before this stroke treatment is used to treat human patients. More animal tests are needed; and then, if all goes well, there will be human trials. The research by Thomas Carmichael and his colleagues was published online by the journal Nature.

1 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。

2 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》

3 clot   

n.凝块；v.使凝成块

参考例句：

• Platelets are one of the components required to make blood clot.血小板是血液凝固的必须成分之一。
• The patient's blood refused to clot.病人的血液无法凝结。

4 regain   

vt.重新获得，收复，恢复

参考例句：

• He is making a bid to regain his World No.1 ranking.他正为重登世界排名第一位而努力。
• The government is desperate to regain credibility with the public.政府急于重新获取公众的信任。

5 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。

6 inhibits   

阻止，抑制( inhibit的第三人称单数 )； 使拘束，使尴尬

参考例句：

• A small manufacturing sector inhibits growth in the economy. 制造业规模太小有碍经济增长。
• His bad English inhibits him from speaking freely. 他英语学得不好，这使他不能表达自如。

7 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。

8 timing   

n.时间安排，时间选择

参考例句：

• The timing of the meeting is not convenient.会议的时间安排不合适。
• The timing of our statement is very opportune.我们发表声明选择的时机很恰当。