VOA慢速英语 2008 0326a

Health Report - New Drug Shows Promise Against Worm Disease
Experts worry that the parasite¹ that causes schistosomiasis could become resistant² to an existing treatment. Transcript³ of radio broadcast:
25 March 2008

 

This is the VOA Special English Health Report.
　

Schistosoma mansoni, one of three major kinds of worms that cause schistosomiasis

Scientists think they are a step closer to a new drug to treat schistosomiasis. More than two hundred million people suffer from this parasitic⁴ worm disease. Most live in developing nations in tropical climates. About ten percent of victims become seriously disabled from internal bleeding, iron loss, organ damage or other effects.

A team in the United States found that chemical compounds known as oxadiazoles can target an enzyme⁵ needed for the survival of Schistosoma. This is the group of flatworms that cause schistosomiasis.

The scientists tested oxadiazoles on laboratory mice. They found that one compound killed the parasite at every level of development – from larva to adult. The study also showed that the compound was active against all three major species of Schistosoma worms that infect humans.

The National Institutes of Health supported the research. Scientists from Illinois State University and the Chemical Genomics Center at N.I.H. reported their findings in the journal Nature Medicine.

Biology professor David Williams led the research. He says the Schistosoma parasite needs oxygen to survive. Oxygen use produces oxygen-free radicals⁶ that can destroy an organism. The worm has a protective enzyme. But Professor Williams says the experimental drug disables this enzyme, causing the worm to self-destruct.

Since the nineteen eighties, doctors in more than seventy tropical nations have used one main drug to treat schistosomiasis. Public health experts worry that the worms will become resistant to this drug, praziquantel.

Each year, two hundred eighty thousand people die of schistosomiasis, also known as bilharzia or snail⁷ fever. The microscopic⁸ worms infect snails⁹, which in turn lay infected eggs. Humans become infected when they enter fresh water where the snails live.

The worms dig through skin to enter the body. They move into blood vessels¹⁰ that supply the intestinal¹¹ and urinary systems. Then, if worm eggs in human waste enter fresh water, more snails and people become infected.

More studies are needed on the experimental new drug. The scientists say the results in mice were better than all the targets set by the World Health Organization for new schistosomiasis compounds. They hope the drug will be ready for testing in humans in four to five years.

And that’s the VOA Special English Health Report, written by Jill Moss¹². Transcripts¹³, MP3s and podcasts of our reports are at voaspecialenglish.com. I’m Steve Ember.

1 parasite   

n.寄生虫；寄生菌；食客

参考例句：

• The lazy man was a parasite on his family.那懒汉是家里的寄生虫。
• I don't want to be a parasite.I must earn my own way in life.我不想做寄生虫，我要自己养活自己。

2 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

3 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。

4 parasitic   

adj.寄生的

参考例句：

• Will global warming mean the spread of tropical parasitic diseases?全球变暖是否意味着热带寄生虫病会蔓延呢？
• By definition,this way of life is parasitic.从其含义来说，这是种寄生虫的生活方式。

5 enzyme   

n.酵素，酶

参考例句：

• Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度，酶分子将会展开。
• An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。

6 radicals   

n.激进分子( radical的名词复数 )；根基；基本原理；[数学]根数

参考例句：

• Some militant leaders want to merge with white radicals. 一些好斗的领导人要和白人中的激进派联合。 来自《简明英汉词典》
• The worry is that the radicals will grow more intransigent. 现在人们担忧激进分子会变得更加不妥协。 来自辞典例句

7 snail   

n.蜗牛

参考例句：

• Snail is a small plant-eating creature with a soft body.蜗牛是一种软体草食动物。
• Time moved at a snail's pace before the holidays.放假前的时间过得很慢。

8 microscopic   

adj.微小的，细微的，极小的，显微的

参考例句：

• It's impossible to read his microscopic handwriting.不可能看清他那极小的书写字迹。
• A plant's lungs are the microscopic pores in its leaves.植物的肺就是其叶片上微细的气孔。

9 snails   

n.蜗牛；迟钝的人；蜗牛( snail的名词复数 )

参考例句：

• I think I'll try the snails for lunch—I'm feeling adventurous today. 我想我午餐要尝一下蜗牛——我今天很想冒险。 来自《简明英汉词典》
• Most snails have shells on their backs. 大多数蜗牛背上有壳。 来自《简明英汉词典》

10 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》

11 intestinal   

adj.肠的；肠壁；肠道细菌

参考例句：

• A few other conditions are in high intestinal obstruction. 其它少数情况是高位肠梗阻。 来自辞典例句
• This complication has occasionally occurred following the use of intestinal antiseptics. 这种并发症偶而发生在使用肠道抗菌剂上。 来自辞典例句

12 moss   

n.苔，藓，地衣

参考例句：

• Moss grows on a rock.苔藓生在石头上。
• He was found asleep on a pillow of leaves and moss.有人看见他枕着树叶和苔藓睡着了。

13 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