VOA慢速英语 SCIENCE IN THE NEWS - Parkinson's Disease: A Movemen

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Barbara Klein.

VOICE TWO:

And I'm Bob Doughty¹. Today we tell about the latest research and treatments for Parkinson's disease.

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VOICE ONE:
　
In some patients, doctors place electrical devices into the brain to reduce the effects of Parkinson's disease

Parkinson's is a disease of the central nervous system. It is a progressive disorder². 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 general signs of Parkinson's disease. These include shaking of the hands, arms and legs. They also include difficulty moving or keeping balanced while walking or standing⁴. Also, there may be emotional changes, like feeling depressed⁵ or worried. The symptoms of Parkinson's differ from person to person. They also differ in their intensity⁶.

VOICE TWO:

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 of the disease. There is no cure for Parkinson's and no way to prevent it. And doctors still are not sure about the cause.

Parkinson's affects more than four million people around the world. It affects more than one million people in North America. Most are older adults.

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VOICE ONE:

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 something they can identify. This might be a medical operation or extreme emotional tension.

Yet many doctors reject this idea of a direct link to Parkinson's. They 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.

Studies have found a link between the disease and some chemical products. Last year, an American study showed such a link between Parkinson's and pesticides⁸, like those used for killing⁹ insects. The study compared three hundred nineteen Parkinson's patients to more than two hundred family members.

VOICE TWO:

Two years ago, a European study showed a link between pesticide⁷ use and Parkinson's. This study also found that serious head injuries also increased a person's risk. Scientists at Aberdeen University in Scotland collected information about more than nine hundred people with Parkinson's or similar conditions. They compared this group to almost two thousand people without the disorder. All the people were asked about their use of pesticides, chemical fluids and metals like iron. The researchers also collected information about family history of the disease and head injuries.

Farm workers and others who said they often used pesticides had a forty-one percent greater risk of Parkinson's than other people. The disease was also two and one-half times more common among people who had been knocked unconscious more than once in their lives. These people temporarily lost consciousness after suffering a blow to the head.

VOICE ONE:

Another area of study is family genetics. There are examples of members of a family having the disease. The National Institutes of Health in the United States says about fifteen percent of people with Parkinson's have a family history of the disease. But most cases involve people with no such family history.

A few years ago, researchers completed what they called the first large map to show genetic¹⁰ links with Parkinson's disease. The map identifies changes in genes¹¹ that may increase the risk in some people.

VOICE TWO:

Recently, a gene³-testing company announced plans for a large genetic study of Parkinson's patients. The company, 23andme, was the idea of Ann Wojcicki.

She is the wife of Sergey Brin, who helped create the Internet search engine Google. He has a gene that increases his risk of developing Parkinson's. His mother has the disease. The company is working with two not-for-profit groups. They hope to collect DNA¹² from ten thousand Parkinson's patients. The goal is to search for common genes that may cause the disease.

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VOICE ONE:

There is no cure for Parkinson's disease. But improved treatments to ease the effects of the disease make it possible for many patients to live almost normal lives. People who have lost their ability to do many things are sometimes able to regain¹³ some of these abilities with treatment.

The most commonly used drug is levodopa. The National Institutes of Health says levodopa is a chemical found naturally in plants and animals. When it reaches the brain, levodopa is changed into dopamine, the chemical that is lacking in people with the disease.

VOICE TWO:

Levodopa helps ease the symptoms of Parkinson's. But it does not prevent more changes in the brain that are caused by the disease. Long-term use can produce unwanted effects in some people. These side effects include feeling sick to the stomach.

To prevent this from happening, levodopa can be combined with other substances, like carbidopa. The National Institutes of Health says carbidopa delays the changes in levodopa until it reaches the brain.

Other drugs used to treat Parkinson's disease act like dopamine. They produce reactions in the nerve cells in the brain. They can be given alone or in combination with levodopa. Many of the possible side effects are similar to those linked with the use of levodopa. They include sleepiness, feeling sick or having bad dreams.

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VOICE ONE:

An operation called deep-brain stimulation¹⁴ also is used to treat Parkinson's disease. Doctors place small electrical devices deep in the brain. The devices are connected to a piece of equipment called a pulse generator¹⁵.

Deep brain stimulation can reduce the need for levodopa and other drugs. It also helps to reduce symptoms such as shaking and slowness of movement. Recently, a report in Science magazine showed how deep-brain stimulation works. It found that the treatment affects neural¹⁶ wires called axons.

The researchers were from Stanford University in California. They used light-sensitive molecules¹⁷ to turn on and off nerve cells in the deep brain structure of mice. Nothing happened when they turned on the light in cells in an area of the brain called the subthalamic nucleus¹⁸. But bursts of electricity on the axons improved movement in the animals.

VOICE TWO:

A separate study found that a less invasive treatment might reduce the symptoms of Parkinson's. It showed that a treatment called dorsal¹⁹ column stimulation could re-establish movement in rodents²⁰ with Parkinson's-like problems. In the study, researchers fired bursts of electricity at the animals' spinal²¹ cords. Romulo Fuentes of Duke University in North Carolina led the researchers. He noted²² that doctors already use spinal cord stimulation in people to help reduce long-lasting pain.

VOICE ONE:

Scientists are also exploring other experimental treatments. In March, President Obama ended restrictions²³ on the use of federal money for research using human embryonic²⁴ stem cells. Stem cells from very early embryos²⁵ are able to grow into any tissue in the body. Scientists say such cells might be able to cure or treat diseases like Parkinson's. But opponents say stem cell experiments are wrong because human embryos are destroyed. They say this is just like destroying a human life.

VOICE TWO:
　
Michael J. Fox

American actor Michael J. Fox has had Parkinson's disease for eighteen years. But unlike most patients, he got the disease as a young man. He is forty-seven now and has many symptoms of the disease. But Fox still acts on television, writes books and is an activist²⁶ for Parkinson's. The Michael J. Fox Foundation has raised more than one hundred forty-two million dollars to fund research for better treatments. Michael J. Fox says he is sure that a cure for Parkinson's disease will be found in the future.

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VOICE ONE:

This SCIENCE IN THE NEWS was written by George Grow. Our producer was Brianna Blake. I'm Barbara Klein.

VOICE TWO:

And I'm Bob Doughty. Transcripts²⁷, MP3s and podcasts of our programs are at voaspecialenglish.com. 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 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。

3 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。

4 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。

5 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。

6 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。

7 pesticide   

n.杀虫剂，农药

参考例句：

• The pesticide was spread over the vegetable plot.菜田里撒上了农药。
• This pesticide is diluted with water and applied directly to the fields.这种杀虫剂用水稀释后直接施用在田里。

8 pesticides   

n.杀虫剂( pesticide的名词复数 )；除害药物

参考例句：

• vegetables grown without the use of pesticides 未用杀虫剂种植的蔬菜
• There is a lot of concern over the amount of herbicides and pesticides used in farming. 人们对农业上灭草剂和杀虫剂的用量非常担忧。 来自《简明英汉词典》

9 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

10 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。

11 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

12 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

13 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。

14 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。

15 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。

16 neural   

adj.神经的，神经系统的

参考例句：

• The neural network can preferably solve the non- linear problem.利用神经网络建模可以较好地解决非线性问题。
• The information transmission in neural system depends on neurotransmitters.信息传递的神经途径有赖于神经递质。

17 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

18 nucleus   

n.核，核心，原子核

参考例句：

• These young people formed the nucleus of the club.这些年轻人成了俱乐部的核心。
• These councils would form the nucleus of a future regime.这些委员会将成为一个未来政权的核心。

19 dorsal   

adj.背部的，背脊的

参考例句：

• His dorsal fin was down and his huge pectorals were spread wide.它的脊鳍朝下耷拉着，巨大的胸鳍大张着。
• The shark's dorsal fin was cut off by the fisherman.鲨鱼的背鳍被渔夫割了下来。

20 rodents   

n.啮齿目动物( rodent的名词复数 )

参考例句：

• Rodents carry diseases and are generally regarded as pests. 啮齿目动物传播疾病，常被当作害虫对待。 来自《简明英汉词典》
• Some wild rodents in Africa also harbor the virus. 在非洲，有些野生啮齿动物也是储毒者。 来自辞典例句

21 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。

22 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。

23 restrictions   

约束( restriction的名词复数 )； 管制； 制约因素； 带限制性的条件（或规则）

参考例句：

• I found the restrictions irksome. 我对那些限制感到很烦。
• a snaggle of restrictions 杂乱无章的种种限制

24 embryonic   

adj.胚胎的

参考例句：

• It is still in an embryonic stage.它还处于萌芽阶段。
• The plan,as yet,only exists in embryonic form.这个计划迄今为止还只是在酝酿之中。

25 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

26 activist   

n.活动分子，积极分子

参考例句：

• He's been a trade union activist for many years.多年来他一直是工会的积极分子。
• He is a social activist in our factory.他是我厂的社会活动积极分子。

27 transcripts   

n.抄本（ transcript的名词复数 ）；转写本；文字本；副本

参考例句：

• Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样，都是染色体DNA的转录产物。 来自辞典例句
• You can't take the transfer students'exam without your transcripts. 没有成绩证明书，你就不能参加转学考试。 来自辞典例句