VOA慢速英语20060830a

HEALTH REPORT - Scientists Develop Stem Cells Without Loss of EmbryosBy Caty Weaver³

Broadcast: Wednesday, August 30, 2006

This is the VOA Special English Health Report.

Researchers say they have found a way to produce stem cells from human embryos² without harm to the embryo¹.


Image from Advanced Cell Technology shows a single cell being removed from a human embryo

The technology uses a single cell taken from an eight-cell embryo known as a blastocyst. The researchers say that from among the cells they removed, they developed two stem cell lines that were genetically⁵ normal.

Company scientists at Advanced Cell Technology in Worchester, Massachusetts, did the experiment.

Nature magazine published the study online last week.

Current technology uses cells from blastocysts that are more developed. But the process destroys the ability of the embryo to continue to grow.

Embryonic⁶ stem cells are able to develop into all of the different kinds of cells in the body. Many scientists believe embryonic stem cells could be used to develop new treatments for diseases.

But the scientific use of embryos is an issue of debate. Some people, including President Bush, say destroying the embryo destroys life.

The removal of a single cell from a blastocyst is not a new idea. It is often done when people go for reproductive assistance at fertility clinics. The process is called preimplantation genetic⁴ diagnosis⁷, or P.G.D. A cell is removed to test for genetic disorders⁸. The cell is destroyed in the process. But the blastocyst from which it came can continue to develop into an embryo and then a fetus⁹.

Robert Lanza of Advanced Cell Technology was the senior author of the new study. In a statement he said it demonstrates that stem cells can be produced without interfering¹⁰ with the embryo's potential for life. Doctor Lanza said that to date, more than one thousand five hundred healthy children have been born following P.G.D.

The company's chief executive officer, William Caldwell, tells us there is no evidence that the removal of a single cell has any effect on the embryo.

Some people say this method could end the moral debate over the use of embryonic stem cells. But other people think that is not likely.

The Bush administration, in a statement, said: Any use of human embryos for research purposes raises serious ethical¹¹ concerns. But a presidential spokeswoman said the study does hold some promise, and that the president believed it should get a good look.

And that's the Special English Health Report, written by Caty Weaver. You can read transcripts¹² of our reports and download audio files to listen on an MP3 player, at www.unsv.com. I'm Barbara Klein.

1 embryo   

n.胚胎，萌芽的事物

参考例句：

• They are engaging in an embryo research.他们正在进行一项胚胎研究。
• The project was barely in embryo.该计划只是个雏形。

2 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

3 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。

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 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。

7 diagnosis   

n.诊断，诊断结果，调查分析，判断

参考例句：

• His symptoms gave no obvious pointer to a possible diagnosis.他的症状无法作出明确的诊断。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做一次彻底的调查分析。

8 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》

9 fetus   

n.胎，胎儿

参考例句：

• In the fetus,blood cells are formed in different sites at different ages.胎儿的血细胞在不同时期生成在不同的部位。
• No one knows why a fetus is not automatically rejected by the mother's immune system. 没有人知道为什么母亲的免疫系统不会自动排斥胎儿。

10 interfering   

adj. 妨碍的 动词interfere的现在分词

参考例句：

• He's an interfering old busybody! 他老爱管闲事！
• I wish my mother would stop interfering and let me make my own decisions. 我希望我母亲不再干预，让我自己拿主意。

11 ethical   

adj.伦理的，道德的，合乎道德的

参考例句：

• It is necessary to get the youth to have a high ethical concept.必须使青年具有高度的道德观念。
• It was a debate which aroused fervent ethical arguments.那是一场引发强烈的伦理道德争论的辩论。

12 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