VOA慢速英语-Health Report - Scientists Link Gene Changes to Long

A study looks at mutations that seem to play a part in extending longevity¹, while limiting growth. Transcript² of radio broadcast:
10 June 2008

This is the VOA Special English Health Report.
　

Five women in Rolla, Missouri, all at least 100 years old

Scientists continue to search for genetic³ answers to why some people live a long time.

One study has now examined more than four hundred fifty people between the ages of ninety-five and one hundred ten. Researchers at the Albert Einstein College of Medicine of Yeshiva University in New York recently reported the latest findings.

The study looked at changes in genes⁴ that govern an important cell-signaling pathway. These genes are involved in the action of a hormone⁵ that affects almost every kind of cell in the body. The hormone is called insulin-like growth factor, or IGF-one.

Other researchers have found that mutations to the genes cause two effects in animals. The animals do not grow as big as others of their kind but they live longer. The Einstein team wondered if these changes might also influence how long humans live.

So they looked for the mutations in their study group of Ashkenazi, or Eastern European, Jews. Ashkenazi Jews are more genetically⁶ similar than most other groups, so any differences are easier to find.

The researchers compared the findings to other Ashkenazi Jews whose family members did not live as long. In the control group, they say, no one had the mutations. Yet even in the study group, where the average age was one hundred, only two percent of the people had them.

In other words, there are more answers waiting to be found. In recent years, the scientists have even identified so-called longevity genes.

The latest findings were published in the Proceedings⁷ of the National Academy of Sciences.

The mutations were found mostly in women. Daughters of those who lived to be one hundred had higher levels of the hormone than people in the control group. And they were an average of two and a half centimeters shorter.

A drug that decreases the action of the IGF-one hormone is currently being tested as a cancer treatment. Nir Barzilai, leader of the Einstein study, says the drug could be useful in delaying the effects of aging.

But he noted⁸ that the subjects in the study were born with their mutations. So it is not clear whether the drug would help people who receive it later.

Doctor Barzilai also points out that many people are receiving treatments with human growth hormone to try to delay the effects of aging. Yet he says if low growth-hormone action extends life, as the new findings suggest, then he wonders if getting more of it could shorten life.

And that's the VOA Special English Health Report. I'm Steve Ember.

1 longevity   

n.长命；长寿

参考例句：

• Good habits promote longevity.良好的习惯能增长寿命。
• Human longevity runs in families.人类的长寿具有家族遗传性。

2 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

3 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。

4 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

5 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。

6 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

7 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

8 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。