VOA慢速英语20060314b

SCIENCE IN THE NEWS - Parkinson's Disease: A Movement Disorder¹ and a Medical MysteryBy George Grow and Oliver Chanler

Broadcast: Tuesday, March 14, 2006

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VOICE ONE:

This is SCIENCE IN THE NEWS, in VOA Special English. I'm Bob Doughty².

VOICE TWO:

And I'm Faith Lapidus. Our subject this week is Parkinson's disease.

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VOICE ONE:

Muhammad Ali is known around the world as one of the great sports stars of the twentieth century. He needed great energy and power to became the world boxing champion.


Muhammad Ali and another celebrity³ with Parkinson's disease, actor Michael J. Fox, before the start of a Senate hearing on the disorder in 2002

As he grew older, though, he began to change. The energy and power began to disappear. His face lost its expressiveness⁴. His legs lost their speed.

Muhammad Ali is sixty-four now and long retired⁵ from boxing. Yet it was not age that changed him so much. It was Parkinson's disease.

VOICE TWO:

Parkinson's is a disease of the central nervous system. It is a progressive disorder. It gets worse over time.

The disease affects a small area of cells in the middle of the brain. This area is called the substantia nigra. The cells slowly lose their ability to produce a chemical called dopamine.

The decrease in the amount of dopamine can result in one or more of the general signs of Parkinson's disease.

These include shaking in the hands, arms and legs. They also include difficulty in moving or general slowness of movement. Another symptom is difficulty keeping balanced while walking or standing⁷.

Other signs in some people include decreased movement of the face. Victims might swallow less often than normal. And they might have difficulty forming words when they talk. Also, there can be emotional changes, like feeling depressed⁸ or worried.

VOICE ONE:

The disease is named after James Parkinson. He was a British doctor who first described this condition in eighteen seventeen. Doctor Parkinson did not know what caused it.

During the nineteen sixties, medical researchers discovered changes in the brains of people with the disease. These discoveries led to medicines to treat the effects. There is no cure, however, and no way that doctors know of to prevent it. And there is still mystery about the cause.

Parkinson's is found in all parts of the world. At least six million people have the disease. Most are older adults. But fifteen percent of patients develop the disease before they are fifty years old. Also, it affects men a little more often than women.

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VOICE TWO:

You are listening to SCIENCE IN THE NEWS in VOA Special English from Washington.

Most patients have what is called idiopathic Parkinson's disease. Idiopathic means the cause is unknown. People who develop the disease often want to link it to some cause they can identify. This might be an injury or a medical operation or extreme emotional stress.

Many doctors, however, reject this idea of a direct link to Parkinson's. The doctors point to other people who have similar experiences and do not develop the disease. Still, doctors say it is possible that such events might cause symptoms of Parkinson's to appear earlier than they would have.

VOICE ONE:

Some medicines used to treat other problems can cause movement disorders⁹ similar to Parkinson's disease. These include medicines used to treat older adults who see things that do not exist. And they include some drugs used to treat people suffering from extreme tension or from stomach problems.

Another disease that can cause movement problems and other effects like those of Parkinson's is encephalitis. In the early twentieth century, encephalitis spread to many parts of the world.

Many victims of the disease had symptoms similar to Parkinson's disease. This led to investigations¹⁰ into the possibility of a virus as a cause of Parkinson's. But scientists could not find evidence to support this theory.

VOICE TWO:

Another area of study is family genetics. There are some cases of many members of a family having the disease.

In two thousand four, scientists linked changes in a gene⁶ called PARK-eight to cases of Parkinson's disease in some families. They identified the gene in a study of five families with a history of the disease. The families lived in England and in the Basque area of Spain.

VOICE ONE:

Other research involves genes¹² that might increase the risk of Parkinson's disease in some ethnic¹³ groups. Two new studies looked for changes in a gene called LRRK-two as a cause of Parkinson's in Jews and North African Arabs.

Researchers in the United States led one of the studies. They tested the genes of one hundred twenty Ashkenazi Jews with Parkinson's disease. Ashkenazi Jews are those whose ancestors came from eastern Europe.

The study found changes in the LRRK-two gene in eighteen percent of the patients. That compares to just one percent of a healthy group. The rate was highest, thirty percent, among patients with a family history of Parkinson's.

VOICE TWO:

Researchers in France and Algeria carried out the other study. They tested the genes of fifty-nine North African Arabs with Parkinson's disease. They found the same genetic¹¹ changes in about forty percent of them, compared to three percent in a healthy group.

The New England Journal of Medicine published the results of both studies at the end of January.

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VOICE ONE:

Improved treatments to ease the symptoms of Parkinson's disease make it possible for many patients to live almost normal lives. People who have lost their ability to do many things might be able to regain¹⁴ some of their old abilities with treatment.

The most commonly used drug is levodopa. When it reaches the brain, levodopa is changed into dopamine, the chemical that is lacking in people with the disease.

Levodopa helps deal with the symptoms of Parkinson's. But it does not prevent more changes in the brain that are caused by the disease. It can also produce unwanted effects in some people.

These side effects include feeling sick to the stomach. To prevent this from happening, other substances can be combined with levodopa.

Other drugs used to treat Parkinson's disease act like dopamine. They produce reactions in the nerve cells in the brain.

Experts at the National Institutes of Health say an antiviral drug called amantadine also appears to reduce symptoms of the disease.

VOICE TWO:

Doctors sometimes perform operations to treat Parkinson's. Recently, the United States Food and Drug Administration approved an operation called deep brain stimulation¹⁵, or D.B.S. Doctors place small electrical devices into the brain. These are connected to a small piece of equipment called a pulse generator¹⁶.

Deep brain stimulation can reduce the need for levodopa and other drugs. It also helps to reduce symptoms such as shaking, slowness of movement and problems with walking.

VOICE ONE:

Another development in the treatment of Parkinson's disease is brain tissue transplants. This involves replacing tissue in areas connected to symptoms of the disease.

Early experiments used brain tissue from unborn babies. Doctors said the experiments appeared to have highly successful results. But the experiments became a subject of moral debate over the issue of ending unwanted pregnancies¹⁷.

Researchers have begun working with genetically¹⁸ changed cells and animal cells that can be made to produce dopamine.

Still, most doctors agree that such operations should be considered only after drugs fail to treat the signs of Parkinson's disease.

VOICE TWO:

The symptoms of Parkinson's differ from person to person. They also differ in their intensity¹⁹. Some people develop minor²⁰ effects. Others become severely²¹ disabled as the effects get worse.

Around the world, there are groups that provide education and support services for patients and their families. Last month, the World Parkinson Congress took place in Washington, D.C. More than two thousand people, from scientists to patients, gathered to discuss the latest progress and treatments.

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VOICE ONE:

SCIENCE IN THE NEWS was written by George Grow and Oliver Chanler. Cynthia Kirk was our producer. I'm Bob Doughty.

VOICE TWO:

And I'm Faith Lapidus. Read and listen to our programs at www.unsv.com. And we hope you join us again next week for more news about science in Special English on the Voice of America.

1 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

2 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。

3 celebrity   

n.名人，名流；著名，名声，名望

参考例句：

• Tom found himself something of a celebrity. 汤姆意识到自己已小有名气了。
• He haunted famous men, hoping to get celebrity for himself. 他常和名人在一起, 希望借此使自己获得名气。

4 expressiveness   

n.富有表现力

参考例句：

• His painting rose to a fresh expressiveness and revealed a shrewder insight. 他的画富有一种新的表达力，显示出更敏锐的洞察力。
• The audiences are impressed by the expressiveness of the actors. 演员们的丰富表情给观众留下了深刻的印象。

5 retired   

adj.隐退的，退休的，退役的

参考例句：

• The old man retired to the country for rest.这位老人下乡休息去了。
• Many retired people take up gardening as a hobby.许多退休的人都以从事园艺为嗜好。

6 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

7 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

8 depressed   

adj.沮丧的，抑郁的，不景气的，萧条的

参考例句：

• When he was depressed,he felt utterly divorced from reality.他心情沮丧时就感到完全脱离了现实。
• His mother was depressed by the sad news.这个坏消息使他的母亲意志消沉。

9 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》

10 investigations   

（正式的）调查( investigation的名词复数 )； 侦查； 科学研究； 学术研究

参考例句：

• His investigations were intensive and thorough but revealed nothing. 他进行了深入彻底的调查，但没有发现什么。
• He often sent them out to make investigations. 他常常派他们出去作调查。

11 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

12 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

13 ethnic   

adj.人种的，种族的，异教徒的

参考例句：

• This music would sound more ethnic if you played it in steel drums.如果你用钢鼓演奏，这首乐曲将更具民族特色。
• The plan is likely only to aggravate ethnic frictions.这一方案很有可能只会加剧种族冲突。

14 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。

15 stimulation   

n.刺激，激励，鼓舞

参考例句：

• The playgroup provides plenty of stimulation for the children.幼儿游戏组给孩子很多启发。
• You don't get any intellectual stimulation in this job.你不能从这份工作中获得任何智力启发。

16 generator   

n.发电机，发生器

参考例句：

• All the while the giant generator poured out its power.巨大的发电机一刻不停地发出电力。
• This is an alternating current generator.这是一台交流发电机。

17 pregnancies   

怀孕，妊娠( pregnancy的名词复数 )

参考例句：

• Since the wartime population needed replenishment, pregnancies were a good sign. 最后一桩倒不失为好现象，战时人口正该补充。
• She's had three pregnancies in four years. 她在四年中怀孕叁次。

18 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

19 intensity   

n.强烈，剧烈；强度；烈度

参考例句：

• I didn't realize the intensity of people's feelings on this issue.我没有意识到这一问题能引起群情激奋。
• The strike is growing in intensity.罢工日益加剧。

20 minor   

adj.较小(少)的，较次要的；n.辅修学科；vi.辅修

参考例句：

• The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
• I gave him a minor share of my wealth.我把小部分财产给了他。

21 severely   

adv.严格地；严厉地；非常恶劣地

参考例句：

• He was severely criticized and removed from his post.他受到了严厉的批评并且被撤了职。
• He is severely put down for his careless work.他因工作上的粗心大意而受到了严厉的批评。