VOA慢速英语-Health Report - Cancer Stem Cells Capture Attention

Evidence is seen for a possible cause of solid tumors, but many questions remain. Transcript² of radio broadcast:
24 June 2008

This is the VOA Special English Health Report.

Some experts predict that doctors will someday use stem cells to treat many different diseases. Yet so far there has been less progress in stem cell therapies than many had hoped.

For years, scientists have studied stem-cell treatment of cancer. Doctors now use stem cells in therapies for several forms of the disease. But at the same time, researchers increasingly are examining a possible connection between stem cells and cancer.

A large number of researchers now point to stem cells as a possible cause of solid tumors. Studies have reported identifying cancer stem cells.
　

Embryonic3 stem cells

Stem cells can develop into any kind of cell, like skin, blood or brain cells. Embryos⁴ have more stem cells than adults. Embryonic stem cells can develop into all the many different tissues that form the body.

But there are stem cells that remain throughout a person's life to replace cells that become damaged. When a stem cell divides, one of the two cells remains⁵ a stem cell. The other becomes a specialized⁶ cell.

Many questions remain to be answered. But the general thinking seems to be that cancer stem cells represent a small population of the cells in a tumor¹. Some researchers think these cancer stem cells have the ability to divide and change into other types of cells. As a result, they think the stem cells help the cancer to metastasize, or spread to other organs.

The researchers also think cancer stem cells are able to repair and feed tumors so they continue to grow. They suspect that the cells are even able to repair damage from radiation treatment and form new tumors. This could explain why some cancers resist drug therapies.

Much of the research into cancer stem cells is being done in California and Canada. Last week, Canadian Health Minister Tony Clement⁷ and California Governor Arnold Schwarzenegger announced joint⁸ efforts. Their governments agreed to provide one hundred million dollars each over the next three years for research into cancer stem cells.

A California company says it is close to tests in humans of a drug that would directly target cancer stem cells. Two scientists who led the discovery of cancer stem cells in solid tumors, Michael Clarke and Max Wicha, started OncoMed Pharmaceuticals⁹ four years ago. OncoMed has signed an agreement with a major drug company, GlaxoSmithKline, to work on the experimental treatment.

And that's the VOA Special English Health Report, written by Caty Weaver¹⁰. I'm Steve Ember.

1 tumor   

n.（肿）瘤，肿块(英)tumour

参考例句：

• He was died of a malignant tumor.他死于恶性肿瘤。
• The surgeons irradiated the tumor.外科医生用X射线照射那个肿瘤。

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 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。

4 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

5 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

6 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。

7 clement   

adj.仁慈的；温和的

参考例句：

• A clement judge reduced his sentence.一位仁慈的法官为他减了刑。
• The planet's history contains many less stable and clement eras than the holocene.地球的历史包含着许多不如全新世稳定与温和的地质时期。

8 joint   

adj.联合的，共同的；n.关节，接合处；v.连接，贴合

参考例句：

• I had a bad fall,which put my shoulder out of joint.我重重地摔了一跤，肩膀脫臼了。
• We wrote a letter in joint names.我们联名写了封信。

9 pharmaceuticals   

n.医药品；药物( pharmaceutical的名词复数 )

参考例句：

• the development of new pharmaceuticals 新药的开发
• The companies are pouring trillions of yen into biotechnology research,especially for pharmaceuticals and new seeds. 这些公司将大量资金投入生物工艺学研究，尤其是药品和新种子方面。 来自《简明英汉词典》

10 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。