VOA慢速英语2009年-SCIENCE IN THE NEWS - Aspirin Research Kee

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty¹.

VOICE TWO:

And I'm Faith Lapidus. This week, we will tell the story of aspirin².

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VOICE ONE:

People have known since ancient times that aspirin can reduce pain and high body temperature. But that is not all the drug can do. It has gained important new uses in recent years. Low amounts may help prevent health threats from stroke to heart attack. Recently, researchers reported that aspirin could help patients with one kind of cancer live longer.

At the same time, doctors warn that acid in aspirin can cause bleeding in the stomach and intestines⁴.

But there is promising⁵ evidence of a way to reduce the risk of bleeding. A newly reported British study suggests that taking another drug with a small amount of aspirin may help solve the problem. If that proves true, it would help thousands of people who are seeking to prevent life-threatening conditions.

VOICE TWO:

So, how did aspirin become so important? The story begins two thousand years ago with a willow⁶ tree. The Greek doctor Hippocrates advised his patients to chew on the bark and leaves of the willow.

The tree contains a chemical called salicin. In the eighteen hundreds, researchers discovered how to make salicylic acid from the chemical. In eighteen ninety-seven, a chemist named Felix Hoffmann at Friedrich Bayer and Company in Germany created acetyl salicylic acid.

Later, it became the active substance in a medicine that Bayer called aspirin. The "a" came from acetyl. The "spir" came from the spirea plant, which also produces salicin. And the "in"? That is a common way to end medicine names.

VOICE ONE:

In nineteen eighty-two, a British scientist shared the Nobel Prize in Medicine in part for discovering how aspirin works. Sir John Vane found that aspirin blocks the body from making natural substances called prostaglandins.

Prostaglandins have several effects on the body. Some cause pain and the expansion, or swelling⁷, of damaged tissue. Others protect the lining⁸ of the stomach and small intestine³.

Prostaglandins also make the heart, kidneys and blood vessels¹⁰ work well. But there is a problem. Aspirin works against all prostaglandins, good and bad.

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VOICE TWO:

Scientists learned how aspirin interferes¹² with an enzyme¹³. One form of this enzyme makes the prostaglandin that causes pain and swelling. Another form of the enzyme creates a protective effect. So aspirin can reduce pain and swelling in damaged tissues. But it can also harm the inside of the stomach and small intestine. Sometimes it can cause bleeding.

Aspirin competes with many other medicines for pain and fever these days. The competition includes acetaminophen, the active substance in products like Tylenol. Like the medicine ibuprofen, aspirin is an NSAID -- a non-steroidal anti-inflammatory drug.

VOICE ONE:

Many people take aspirin to reduce the risk of a heart attack or stroke from blood clots¹⁴. Clots can block the flow of blood to the heart or brain and cause a heart attack or stroke. Scientists say aspirin prevents blood cells called platelets from sticking together to form clots.

A California doctor named Lawrence Craven first noted¹⁵ this effect about sixty years ago. He observed unusual bleeding in children who chewed on an aspirin product to ease the pain after a common operation.

Doctor Craven believed that the bleeding took place because aspirin prevented blood from thickening. He thought that this effect might help prevent heart attacks caused by blood clots.

He examined the medical records of eight thousand aspirin users and found no heart attacks in this group. He invited other scientists to test his ideas. But it was years before large studies took place.

VOICE TWO:

Charles Hennekens of Harvard Medical School led one of the studies. In nineteen eighty-three, he began to study more than twenty-two thousand healthy male doctors over forty years of age. Half took an aspirin every other day. The others took what they thought was aspirin. It was only a placebo¹⁶, a harmless substance.

Five years later, Doctor Hennekens reported that those who took aspirin reduced their risk of a heart attack. But they had a higher risk of bleeding in the brain than the other doctors.

VOICE ONE:

More recently, a group of experts examined studies of aspirin at the request of federal health officials in the United States. The experts said people with an increased risk of a heart attack should take a low-strength aspirin every day.

Aspirin may help someone who is having a heart attack caused by a blockage¹⁷ in a blood vessel⁹. Aspirin thins the blood, so it may be able to flow past the blockage. But heart experts say people should seek emergency help immediately. They say an aspirin is no substitute for treatment.

VOICE TWO:

Studies also suggest that aspirin can help with cancer prevention and survival. Several studies have found that men who take NSAIDS have a decreased risk of prostate cancer. The prostate is part of the male reproductive system.

Researchers at the Mayo Clinic in Minnesota wanted to see how NSAIDs might affect prostates that are enlarged but not cancerous. They followed the health of two thousand five hundred men for twelve years. One-third were taking NSAIDs daily when they entered the study.

The researchers said these drugs may delay or stop development of an enlarged prostate. They said the risk of an enlarged prostate was fifty percent lower in the NSAID users than the other men. The risk of bladder problems was thirty-five percent lower.

VOICE ONE:

Another study found that aspirin blocks the formation of blood vessels that feed cancer growth. Researchers at Newcastle University in England explored a biological process that makes blood vessels grow.

The researchers studied how aspirin affects the cells found on the inner surface of blood vessels. They found that a small amount of aspirin suppressed the way the cells form tubes.

Studies have found that aspirin may help prevent cancers of the stomach, intestines and colon¹⁸. Research reported earlier this year told about people who had colorectal cancer. They found that aspirin users had an almost thirty percent lower risk of dying from their cancer. That was during an average of eleven years after the cancer was discovered.

VOICE TWO:

Aspirin does not help everything, however. It can cause problems. For example, it can interfere¹¹ with other medicines, although this is true of many drugs.

Also, some people should not take aspirin. People who take other blood thinners or have bleeding disorders¹⁹ are among this group. Pregnant women are usually told to avoid aspirin.

Research has shown a link between aspirin use and the disease Reye's Syndrome²⁰. Children's doctors say patients up to age nineteen should not take anything containing Salicylatic products when sick with high temperatures.

The National Reye's Syndrome Foundation warns about aspirin use, especially during the spread of influenza²¹. In the past, children have died or suffered permanent harm from Reye's Syndrome during widespread influenza attacks.

VOICE ONE:

People taking low-dose aspirin who fear stomach and intestinal²² ulcers²³ and bleeding had some good news a few months ago. The British medical journal "Lancet" published a study about the drug famotidine, also known as Pepcid. The study suggested that famotidine taken with low-dose aspirin may prevent ulcers. This break down of tissue can cause bleeding.

The patients took seventy-five to three hundred twenty-five milligrams of aspirin a day. After twelve weeks, three percent of those taking famotidine with the aspirin had stomach ulcers. But fifteen percent of those taking the placebo and aspirin had them. Upper intestinal ulcers were found in only one-half of one percent of the famotidine group. In the placebo group, seventeen percent had these ulcers.

VOICE TWO:

Still, medical experts say people should not take aspirin for disease prevention without first talking to a doctor.

There are risks, and researchers have reported that some people get little or no protection from aspirin. But research continues to give new life to one of the oldest and most widely used drugs in the world.

VOICE ONE:

This SCIENCE IN THE NEWS was written by George Grow and Jerilyn Watson. Our producer was Brianna Blake. I'm Bob Doughty.

VOICE TWO:

And I'm Faith Lapidus. Join us again next week for more news about science in Special English on the Voice of America.

1 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

2 aspirin   

n.阿司匹林

参考例句：

• The aspirin seems to quiet the headache.阿司匹林似乎使头痛减轻了。
• She went into a chemist's and bought some aspirin.她进了一家药店，买了些阿司匹林。

3 intestine   

adj.内部的；国内的；n.肠

参考例句：

• This vitamin is absorbed through the walls of the small intestine.这种维生素通过小肠壁被吸收。
• The service productivity is the function,including external efficiency,intestine efficiency and capacity efficiency.服务业的生产率是一个包含有外部效率、内部效率和能力效率的函数。

4 intestines   

n.肠( intestine的名词复数 )

参考例句：

• Perhaps the most serious problems occur in the stomach and intestines. 最严重的问题或许出现在胃和肠里。 来自辞典例句
• The traps of carnivorous plants function a little like the stomachs and small intestines of animals. 食肉植物的捕蝇器起着动物的胃和小肠的作用。 来自辞典例句

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 willow   

n.柳树

参考例句：

• The river was sparsely lined with willow trees.河边疏疏落落有几棵柳树。
• The willow's shadow falls on the lake.垂柳的影子倒映在湖面上。

7 swelling   

n.肿胀

参考例句：

• Use ice to reduce the swelling. 用冰敷消肿。
• There is a marked swelling of the lymph nodes. 淋巴结处有明显的肿块。

8 lining   

n.衬里，衬料

参考例句：

• The lining of my coat is torn.我的外套衬里破了。
• Moss makes an attractive lining to wire baskets.用苔藓垫在铁丝篮里很漂亮。

9 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。

10 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

11 interfere   

v.(in)干涉，干预；(with)妨碍，打扰

参考例句：

• If we interfere, it may do more harm than good.如果我们干预的话，可能弊多利少。
• When others interfere in the affair,it always makes troubles. 别人一卷入这一事件，棘手的事情就来了。

12 interferes   

vi. 妨碍，冲突，干涉

参考例句：

• The noise interferes with my work. 这噪音妨碍我的工作。
• That interferes with my plan. 那干扰了我的计划。

13 enzyme   

n.酵素，酶

参考例句：

• Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度，酶分子将会展开。
• An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。

14 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》

15 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

16 placebo   

n.安慰剂；宽慰话

参考例句：

• The placebo has been found to work with a lot of different cases.人们已发现安慰剂能在很多不同的病例中发挥作用。
• The placebo effect refers to all the observable behaviors caused by placebo.安慰剂效应是指由安慰剂所引起的可观察的行为。

17 blockage   

n.障碍物；封锁

参考例句：

• The logical treatment is to remove this blockage.合理的治疗方法就是清除堵塞物。
• If the blockage worked,they could retreat with dignity.如果封锁发生作用，他们可以体面地撤退。

18 colon   

n.冒号，结肠，直肠

参考例句：

• Here,too,the colon must be followed by a dash.这里也是一样，应当在冒号后加破折号。
• The colon is the locus of a large concentration of bacteria.结肠是大浓度的细菌所在地。

19 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》

20 syndrome   

n.综合病症；并存特性

参考例句：

• The Institute says that an unidentified virus is to blame for the syndrome. 该研究所表示,引起这种综合症的是一种尚未确认的病毒。
• Results indicated that 11 fetuses had Down syndrome. 结果表明有11个胎儿患有唐氏综合征。

21 influenza   

n.流行性感冒，流感

参考例句：

• They took steps to prevent the spread of influenza.他们采取措施
• Influenza is an infectious disease.流感是一种传染病。

22 intestinal   

adj.肠的；肠壁；肠道细菌

参考例句：

• A few other conditions are in high intestinal obstruction. 其它少数情况是高位肠梗阻。 来自辞典例句
• This complication has occasionally occurred following the use of intestinal antiseptics. 这种并发症偶而发生在使用肠道抗菌剂上。 来自辞典例句

23 ulcers   

n.溃疡( ulcer的名词复数 )；腐烂物；道德败坏；腐败

参考例句：

• Detachment of the dead cells produces erosions and ulcers. 死亡细胞的脱落，产生糜烂和溃疡。 来自辞典例句
• 75% of postbulbar ulcers occur proximal to the duodenal papilla. 75％的球后溃疡发生在十二指肠乳头近侧。 来自辞典例句