HEALTH REPORT - Scientists Work on a 'Smart Bomb' Against Ca

HEALTH REPORT - Scientists Work on a 'Smart Bomb' Against Cancer
By Cynthia Kirk

Broadcast: Wednesday, August 24, 2005

I'm Steve Ember with the VOA Special English Health Report.

Scientists have developed a new cancer drug. So far, they have tested it in only in laboratory¹ animals. The drug is designed to invade² and kill cancer cells but not healthy cells.

First, the drug enters the cancer and destroys the supply of blood. Then it releases⁴ poison to destroy the cancer cells.

Researchers at the Massachusetts Institute of Technology in Cambridge carried out the study. The results appeared in Nature magazine. A school news release³ called the drug an "anti-cancer smart bomb."

Ram⁵ Sasisekharan is a professor at M.I.T. He says his team had to solve three problems. They had to find a way to destroy the blood vessels⁶, then to prevent the growth of new ones. But they also needed the blood vessels to supply chemicals to destroy the cancer.

So, the researchers designed a two-part "nanocell." The cell is measured in nanometers, or one thousand-millionth of a meter. The particle⁷ used was two hundred nanometers -- much, much smaller than a human hair.

The scientists say it was small enough to pass through the blood vessels of the cancer. But it was too big to enter normal blood vessels. The surface of the nanocells also helped them to avoid natural defenses.

The scientists designed the cell as a balloon inside a balloon. They loaded the outer part with a drug that caused the blood vessels to fall in on themselves. That cut off the blood supply and trapped the nanocell inside the cancer. Then, the nanocell slowly released⁸ chemotherapy drugs to kill the cancer cells.

The team says the treatment shrank⁹ the cancer and avoided healthy cells better than other treatments. Untreated mice with cancer survived for twenty days. The scientists say mice with the best current treatments lived thirty days. But they say eighty percent of the mice treated with the nanocells lived more than sixty-five days.

The study involved two different forms of cancer. The team says the treatment worked better against melanoma, a deadly skin cancer, than against lung cancer. However, more studies are needed before the new drug can be tested in humans.

This VOA Special English Health Report was written by Cynthia Kirk.  I'm Steve Ember.

1 laboratory   

n.实验室，化验室

参考例句：

• She has donated money to establish a laboratory.她捐款成立了一个实验室。
• Our laboratory equipment isn't perfect,but we must make do.实验室设备是不够理想，但我们只好因陋就简。

2 invade   

v.侵略，侵犯；闯入，侵扰

参考例句：

• I don't want to invade your private life unnecessarily.我不想过多地干涉你的私生活。
• He ordered the army to invade at dawn.他命令军队在拂晓入侵。

3 release   

vt.发布，发表，发行；释放，放开

参考例句：

• After my examination I had a feeling of release.考完试后我有如释重负之感。
• This medicine will give you release from pain.这药吃后会解除你的疼痛。

4 releases   

v.释放( release的第三人称单数 )；放开；发布；发行

参考例句：

• Nuclear fission releases tremendous amounts of energy. 核裂变释放出巨大的能量。 来自《现代汉英综合大词典》
• Zemel says that when calcium levels are low, the body releases a hormone that helps squeeze the most out of every available milligram of the mineral. 泽莫尔博士说，当人体中的钙含量偏低时，身体里就会产生一种荷尔蒙，它能帮助肌体最大限度地吸收所摄入的钙。 来自《简明英汉词典》

5 ram   

(random access memory)随机存取存储器

参考例句：

• 512k RAM is recommended and 640k RAM is preferred.推荐配置为512K内存，640K内存则更佳。

6 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

7 particle   

n.微粒，颗粒，粒子；小品词，语助词

参考例句：

• There is not a particle of truth in what you said.你所说的没有一句是实话。
• This particle has a very small mass.这种粒子的质量很小。

8 released   

v.释放( release的过去式和过去分词 )；放开；发布；发行

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• With hindsight it is easy to say they should not have released him. 事后才说他们本不应该释放他，这倒容易。

9 shrank   

动词shrink的过去式

参考例句：

• My sweater shrank in the wash. 我的毛衣缩水了。
• The blackman shrank from any direct participation in politics. 这位黑人回避直接插足政治。