VOA慢速英语20060919b

SCIENCE IN THE NEWS - Study Finds Older Fathers Are More Likely to Have Autistic ChildrenBy Caty Weaver¹ and Jerilyn Watson

Broadcast: Tuesday, September 19, 2006

VOICE ONE:

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

VOICE TWO:

And I'm Faith Lapidus. This week -- a report on the link found between older fathers and the risk of autism in children ...

VOICE ONE:

And the story of how scientists genetically⁵ engineered normal cells to fight cancer.

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VOICE TWO:

Findings from a new study suggest a link between a man's age and the chances that his children will develop autism. Researchers found that men age forty and older had autistic children almost six times as often as fathers under the age of thirty.

Men in their thirties were about one and one-half times more likely to father an autistic child as dads in their twenties and teen years.

The study found no link between autism and older mothers.

VOICE ONE:

The study involved children born in Israel in the nineteen eighties. The findings come from the records of medical examinations for seventeen-year-olds for required military service.

The records for more than one hundred thirty thousand teenagers included the ages of both their father and their mother.

Within this group, the records showed that there were one hundred ten cases of autism spectrum⁶ disorder⁷. Autism spectrum disorder is the name for autism and related conditions. The rate of cases was eight out of ten thousand people.

VOICE TWO:

The scientists discuss several possible genetic⁴ causes for the age effect they documented in fathers. They say people should keep in mind, however, that social environments influence the age when a man fathers children. It differs across societies and can change as conditions change over time.

Abraham Reichenberg of Mount Sinai School of Medicine in New York and the Institute of Psychiatry⁸ at King's College, London, led the study. The findings appeared earlier this month in the Archives of General Psychiatry, published by the American Medical Association.

In the last twenty years, more and more children have been identified as autistic. The researchers say the increase is partly the result of more knowledge about autism and changes in how doctors identify it. But they note that it could also represent an increase in this disorder.

VOICE ONE:


Ryan Taylor was diagnosed with autism in 2004; he is shown with his father, Craig, at their home in Connecticut

What exactly is autism? This is not an easy question even for experts to answer. A recent press release from the National Institute of Mental Health, in the United States, described it as a mental disorder. Some people, though, object to such a description. Other materials from the institute have called it a brain disorder.

Autism appears in early childhood. Autistic children experience delays in the development of social and communication skills. These social and language problems usually appear around three years of age.

The disorder is found more often in boys than girls, but girls often have more severe effects.

Autistic children often appear emotionally withdrawn⁹ from other people. They may also show limited interests and repeat the same actions over and over again, like rocking back and forth¹⁰.

Scientists are trying to better understand autism as they search for its causes and for effective treatments.

VOICE TWO:

On September seventh, the National Institute of Mental Health announced the start of three major studies of autism. These are being done at its research program at the National Institutes of Health in Bethesda, Maryland.

One study aims to define differences in autistic children with different developmental histories. Another study will measure the effectiveness of an antibiotic¹¹ medicine as a treatment for one kind of autism. And the third study will try to find out if chelation [pronounced key-LAY-shun] treatment is effective against autism.

Chelation removes heavy metals from the blood. This treatment is used for children with lead poisoning. But many parents seek it for autistic children to try to remove mercury from their blood. They believe that many cases of autism were caused by vaccines¹³ that contained thimerosal, a mercury-based preservative¹⁴. That theory is debated.

VOICE ONE:

Researchers will carry out a controlled study to test the effectiveness and safety of chelation for children with autism spectrum disorders¹⁵. Institute officials note that chelation does not target mercury alone. It can also remove minerals that the body needs, such as calcium¹⁶, iron and zinc¹⁷.

Federal officials say most vaccines for children age six and younger now contain either no thimerosal or very small amounts. This has been true since two thousand one, they say, but an exception is inactivated¹⁸ flu vaccine¹². Currently there is a limited supply of thimerosal-free vaccine against influenza¹⁹, for use in children six months to twenty-three months old.

VOICE TWO:

The National Institute of Mental Health says autism may represent several different diseases. Autism presents itself in different ways and is part of a larger group of disorders. These are often called autism spectrum disorders. They also include Asperger's syndrome²⁰ and pervasive²¹ developmental disorder.

Institute officials say autism spectrum disorders are currently reported to affect as many as six out of every one thousand children.

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VOICE ONE:

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

Researchers at the National Institutes of Health have successfully used genetic engineering to treat the deadliest form of skin cancer.

The journal Science reported the results of a study of patients with advanced melanoma. Steven Rosenberg led a team at the National Cancer Institute. The study involved seventeen patients. The disease had spread through their bodies. Other treatments had failed.

The researchers changed the genetic structure of the patients' own white blood cells to get them to recognize and attack cancer cells. Two patients are now free of melanoma. They are alive a year and a half after the experimental treatment began. All of the other patients have since died.

VOICE TWO:

Using a person's own white blood cells to treat melanoma is not a new idea. But what doctors have done until now is to look for the most aggressive cancer-killing cells that a patient already has. They grow more of them in the laboratory and return them to the patient's body.

But this treatment is said to work only for melanoma. And it can only be used for patients who already have specialized²² cells that can recognize cancers.

Not very many patients with advanced melanoma produce enough cancer-fighting T-cells naturally in their blood. So Doctor Rosenberg and his team decided²³ to make cancer-fighting cells in their laboratory.

VOICE ONE:

To do this, the scientists removed normal T-cells from the blood of the patients. Then they infected the cells with a retrovirus.

The retrovirus carried special genes²⁴. These genes produce T-cell receptors. Once inside the body, the receptors are able to seek out and work against the melanoma cells.

The team also has found T-cell receptors that can find other common cancers. The head of the National Institutes of Health, Elias Zerhouni, said the results represent the first time gene³ therapy has been used successfully to treat cancer. Scientists say they hope this kind of gene therapy could also be used for breast and lung cancer, among others.

VOICE TWO:

The study showed that engineered cells can stay in the body and, in some cases, shrink large cancers.

Other scientists praised the work of Doctor Rosenberg and his team. But they also said the rate of survival with this method must be improved. Studies continue toward that goal, including the use of total-body radiation to improve the effectiveness.

In the late nineteen eighties, many scientists believed genetic engineering might help fight a number of cancers. Laboratory studies appeared to offer hope. But most human tests were unsuccessful.

(MUSIC)

VOICE ONE:

SCIENCE IN THE NEWS was written by Caty Weaver and Jerilyn Watson and produced by Brianna Blake. I'm Bob Doughty.

VOICE TWO:

And I'm Faith Lapidus. Transcripts²⁵ and audio files of our programs can be found at www.unsv.com. Listen again next week for more news about science in Special English on the Voice of America.

1 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。

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 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 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。

5 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

6 spectrum   

n.谱，光谱，频谱；范围，幅度，系列

参考例句：

• This is a kind of atomic spectrum.这是一种原子光谱。
• We have known much of the constitution of the solar spectrum.关于太阳光谱的构成，我们已了解不少。

7 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。

8 psychiatry   

n.精神病学，精神病疗法

参考例句：

• The study appeared in the Amercian science Journal of Psychiatry.这个研究发表在美国精神病学的杂志上。
• A physician is someone who specializes in psychiatry.精神病专家是专门从事精神病治疗的人。

9 withdrawn   

vt.收回；使退出；vi.撤退，退出

参考例句：

• Our force has been withdrawn from the danger area.我们的军队已从危险地区撤出。
• All foreign troops should be withdrawn to their own countries.一切外国军队都应撤回本国去。

10 forth   

adv.向前；向外，往外

参考例句：

• The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
• He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。

11 antibiotic   

adj.抗菌的；n.抗生素

参考例句：

• The doctor said that I should take some antibiotic.医生说我应该服些用抗生素。
• Antibiotic can be used against infection.抗菌素可以用来防止感染。

12 vaccine   

n.牛痘苗，疫苗；adj.牛痘的，疫苗的

参考例句：

• The polio vaccine has saved millions of lives.脊髓灰质炎疫苗挽救了数以百万计的生命。
• She takes a vaccine against influenza every fall.她每年秋季接种流感疫苗。

13 vaccines   

疫苗，痘苗( vaccine的名词复数 )

参考例句：

• His team are at the forefront of scientific research into vaccines. 他的小组处于疫苗科研的最前沿。
• The vaccines were kept cool in refrigerators. 疫苗放在冰箱中冷藏。

14 preservative   

n.防腐剂；防腐料；保护料；预防药

参考例句：

• New timber should be treated with a preservative.新采的圆木应进行防腐处理。
• Salt is a common food preservative.盐是一种常用的食物防腐剂。

15 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》

16 calcium   

n.钙(化学符号Ca)

参考例句：

• We need calcium to make bones.我们需要钙来壮骨。
• Calcium is found most abundantly in milk.奶含钙最丰富。

17 zinc   

n.锌；vt.在...上镀锌

参考例句：

• Brass is formed by the fusion of copper and zinc.黄铜是通过铜和锌的熔合而成的。
• Zinc is used to protect other metals from corrosion.锌被用来保护其他金属不受腐蚀。

18 inactivated   

v.使不活泼，阻止活动( inactivate的过去式和过去分词 )

参考例句：

• Molluscicides are quickly inactivated by sunlight and adsorption to mud organic matter. 灭螺剂因阳光作用、泥土及有机物质的吸收会很快失效。 来自辞典例句
• Viruses were inactivated by BPL and the toxicity measured again. BPL对病毒进行灭活，测定残存毒力。 来自互联网

19 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。

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 pervasive   

adj.普遍的；遍布的，(到处)弥漫的；渗透性的

参考例句：

• It is the most pervasive compound on earth.它是地球上最普遍的化合物。
• The adverse health effects of car exhaust are pervasive and difficult to measure.汽车尾气对人类健康所构成的有害影响是普遍的，并且难以估算。

22 specialized   

adj.专门的，专业化的

参考例句：

• There are many specialized agencies in the United Nations.联合国有许多专门机构。
• These tools are very specialized.这些是专用工具。

23 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

24 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

25 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