VOA慢速英语2009年-Health Report - Battling a Stroke, and the

This is the VOA Special English Health Report.

Strokes are a major cause of death and disability. A stroke is a loss of blood flow in the brain. There are two kinds. An ischemic stroke happens when a blood vessel¹ in the brain gets blocked. A hemorrhagic, or bleeding, stroke happens when a blood vessel breaks.

People are more likely to die from a bleeding stroke. But ischemic strokes are more common, and doctors may be able to treat them.

A drug called tPA can break up blood clots². But traditional guidelines³ say not to use tPA if more than three hours have passed after the first signs of a stroke.

There is a risk that giving a patient a strong blood thinner during a stroke can cause bleeding inside the brain. The longer the wait, experts say, the more likely that the risks of treatment will outweigh⁴ the benefits.

But recent findings have suggested that tPA may be effective in saving brain tissue even if three to four and a half hours have passed.

Some studies have failed to produce clear evidence to support treatment after three hours. But scientists reported that the evidence was stronger when they combined the results of the four major studies done so far. The new findings appeared in the journal Stroke.

The researchers said tPA improved the chances of a successful result by thirty-one percent and produced no change in the death rate.

Maarten Lansberg at the Stanford University medical school in California worked with scientists from Belgium and Germany. One of them worked for a company that makes tPA for use in Europe. The United States National Institutes of Health paid for the study.

If you think someone is having a stroke, you should seek help immediately. The warning signs usually appear suddenly. These include trouble walking, weakness especially on one side of the body, difficulty seeing and difficulty speaking.

Yet people who seem healthy can suffer a stroke without even knowing it. A study published in Stroke last year involved about two thousand people with an average age of sixty-two. Brain imaging showed that nearly eleven percent of them had suffered what is known as a silent stroke.

The researchers reported a link between silent strokes and a condition called atrial fibrillation. This is the most common cause of abnormal⁵ heartbeat in older adults. Other risk factors for a silent stroke are high blood pressure, heart disease, diabetes⁶ and tobacco use.

And that's the VOA Special English Health Report. For more health news, go to voaspecialenglish.com. I'm Steve Ember.

1 vessel   

n.船舶；容器，器皿；管，导管，血管

参考例句：

• The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
• You should put the water into a vessel.你应该把水装入容器中。

2 clots   

n.凝块( clot的名词复数 )；血块；蠢人；傻瓜v.凝固( clot的第三人称单数 )

参考例句：

• When you cut yourself, blood clots and forms a scab. 你割破了，血会凝固、结痂。 来自《简明英汉词典》
• Milk clots when it turns sour. 奶变酸就凝块。 来自《现代英汉综合大词典》

3 guidelines   

n.指导方针，准则

参考例句：

• The government has drawn up guidelines on the treatment of the mentally ill. 政府制订了对待精神病人的指导方针。
• Planners seem a little uncomfortable with the current government guidelines. 规划师似乎不太接受现行的政府指道方针。

4 outweigh   

vt.比...更重，...更重要

参考例句：

• The merits of your plan outweigh the defects.你制定的计划其优点胜过缺点。
• One's merits outweigh one's short-comings.功大于过。

5 abnormal   

adj.反常的，不正常的，不规则的

参考例句：

• This warm weather is abnormal for February.二月里这种温暖的天气不太正常。
• That is simply abnormal.那简直是反常的。

6 diabetes   

n.糖尿病

参考例句：

• In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。
• Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。