SCIENCE IN THE NEWS - Easier Way to Treat Malaria | Scientis

SCIENCE IN THE NEWS - Easier Way to Treat Malaria¹ | Scientists Grow Human Brain Cells in Mice
By Caty Weaver² and Mario Ritter

Broadcast: Tuesday, December 20, 2005

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VOICE ONE:

This is SCIENCE IN THE NEWS, in VOA Special English. I'm Bob Doughty³.

VOICE TWO:

And I'm Pat Bodnar. This week on our show: Treating malaria an easier way ...

VOICE ONE:

Growing human brain cells in mice ...

VOICE TWO:

Mapping the genes⁴ of cancer ...

VOICE ONE:

And looking to the sky for the December solstice.

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VOICE TWO:

A new treatment for malaria will combine the most effective drugs currently used. And it will be easier to take. A non-profit group called the Drugs for Neglected Diseases Initiative announced the news. It says the treatment will be ready by late next year, and will cost about half the price of current treatments.

 
Malaria, spread by mosquitoes, claims at least one million lives a year. Most who get sick enough from the infection to die are young children in Africa. 
The new treatment will combine artemisinin with one of two kinds of quinine-based drugs. Artemisinin is made from a Chinese plant. Two drug companies have agreed to produce the new treatment: Sanofi-Aventis of France and Far-Manguinhos of Brazil.

Those companies say they will try to keep the cost below one dollar. They also agreed not to earn a profit or seek patent protection for the new treatments. This means other companies will be able to make their own copies.

VOICE ONE:

Currently people have to take many pills to treat a malaria infection. The new treatment comes in one pill taken just two times a day for three days. Bernard Pecoul is director of the Drugs for Neglected Diseases Initiative. He says the simpler the treatment, the more likely people are to complete it.

Now, people commonly have to take two different kinds of pills for malaria. Successful treatment requires both. But only one has a pleasant taste. It also makes people feel better quickly. As a result, Doctor Pecoul says, people often take only that pill.

The new treatment avoids the situation. It combines the two drugs. The single pill will also use the newest medicines. Experts say this is important because the malaria parasite⁵ has developed resistance to older drugs. Yet those older drugs have often been the only ones priced low enough for poor countries to buy.

Doctor Pecoul says his group is seeking approval for the new combination treatment in countries with the highest rates of malaria. These are in Africa, Asia and Latin America.

Several public and private groups established the Drugs for Neglected Diseases Initiative in two thousand three. They include the World Health Organization and the French group Doctors Without Borders.

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VOICE TWO:

You are listening to SCIENCE IN THE NEWS in VOA Special English, from Washington.

Scientists in La Jolla, California, say they have grown human brain cells in mice. The researchers at the Salk Institute used human stem cells in the process. Stem cells can develop into other kinds of cells, including brain cells.

The researchers say they placed about one hundred thousand stem cells into the brains of mouse embryos⁶. The embryos were two weeks old. The researchers removed them from pregnant mice temporarily to inject the embryos with the stem cells.

The stem cells came from human embryos very early in their development. They were engineered to produce a green light. This made it easy to see which cells developed from the human material and which came from the mice.

VOICE ONE:

Professor Fred Gage⁷ led the research. He says most of the human stem cells did not survive. Less than one percent became human brain cells in the mice. But Mister Gage says those that did survive developed into fully⁸ active brain cells.

The professor says the human brain cells adapted to their new environment. They moved around and settled into different areas of the mouse brain. They grew to the size and shape of the surrounding brain cells.

The scientists say they are not sure how or why this happened. But Professor Gage says it shows that injecting human stem cells into a mouse brain does not restructure the brain.

VOICE TWO:

Similar studies in the past used older stem cells and adult mice. Many times the cells formed tumor⁹ growths. Other times the mouse's body simply rejected the human cells.

The scientists at the Salk Institute in California say no such problems appeared when they injected young stem cells into unborn mice. Researcher Allyson Moutri says the findings could lead to new ways to study human disease. The scientists say their work could help speed the testing of drugs to treat diseases that destroy the brain.

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VOICE ONE:

Each year around December twenty-first the sun reaches its southernmost position in the sky. This event is called a solstice. The December solstice marks the beginning of winter for people in the northern half of the world. And it marks the beginning of summer for people in the southern half.

The word solstice comes from French and Latin. It describes a time when the sun appears to stand still as it moves to the north or south. We usually think of the sun as moving only east to west. That gives us day and night. But a slow movement northward¹⁰ and southward gives us our seasons. Really, to be exact, we should say apparent movement.

People used to think the sun orbited the Earth, not the opposite. And how long does one orbit take? It takes one year.

VOICE TWO:

Between the south pole and the north pole is an axis¹¹. Earth turns around this imaginary line. The axis is fixed¹² in space in one direction. But as our planet moves through space, that direction changes in relation to the sun.

At the June solstice, the southern hemisphere is pointed¹³ away from the sun by about twenty-three degrees. At the December solstice, the southern hemisphere is pointed about twenty-three degrees toward the sun.

VOICE ONE:

People who live near the equator have days and nights of fairly equal length all year. They are said to live in the tropics -- that is, the area between the Tropic of Cancer and the Tropic of Capricorn. These are simply lines of latitude¹⁴, lines that measure a position on a map in terms of degrees. If you live between the lines, the seasons all seem pretty much the same.

The June solstice takes place when the sun is directly overhead at the Tropic of Cancer. The Tropic of Cancer is about the same northern latitude as Havana, Cuba. On that day, usually June twenty-first, the sun appears at its northernmost position in the sky.

At the December solstice, the sun is directly overhead at the Tropic of Capricorn, the same southern latitude as Sao Paulo, Brazil.

VOICE TWO:

While the southern half of the world enjoys long days, people in the north have long nights. And the farther north, the longer the nights. Without sunlight, temperatures drop. So our seasons and the length of our days are linked.

The Naval¹⁵ Observatory¹⁶ in Washington says winter solstice will take place at eighteen hours thirty-five Universal Time Wednesday.

Here in Washington, we will have about nine-and-a-half hours of daylight. People in Reykjavik, Iceland, will have less than four hours of sun. If you live in Murmansk, Russia, the sun will not rise at all on the day of the solstice. In fact, you would have last seen the sun on December third. And you will not see it again until January seventh.

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VOICE ONE:

In recent years, scientists have made important progress in studying genetics. In two thousand three, they completed the Human Genome Project -- a map of the genes that make a person.

Now, researchers in the United States plan to do the same with cancer. Experts say more than two hundred different diseases are now defined as cancer. And they say all forms of cancer involve genetic¹⁷ changes.

Last week, the National Institutes of Health announced plans for the Cancer Genome Atlas¹⁸. Doctor Elias Zerhouni, the director of N.I.H., says maps of cancer genes could lead to major improvements in testing and treatment. He says the atlas could also lead to new methods for cancer prevention.

The effort will begin with a three-year test project at a cost of one hundred million dollars.

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VOICE TWO:

Our program was written by Caty Weaver, Jerilyn Watson and Mario Ritter. Cynthia Kirk was our producer. And our thanks to astronomer¹⁹ Mark Stollberg at the Naval Observatory. I'm Pat Bodnar.

VOICE ONE:

And I'm Bob Doughty. Internet users can read and listen to our programs at www.tingroom.com. Join us again next week for SCIENCE IN THE NEWS in VOA Special English.

1 malaria   

n.疟疾

参考例句：

• He had frequent attacks of malaria.他常患疟疾。
• Malaria is a kind of serious malady.疟疾是一种严重的疾病。

2 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。

3 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

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 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。

6 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

7 gage   

n.标准尺寸，规格；量规，量表 [=gauge]

参考例句：

• Can you gage what her reaction is likely to be?你能揣测她的反应可能是什么吗？
• It's difficult to gage one's character.要判断一个人的品格是很困难的。

8 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

9 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。

10 northward   

adv.向北；n.北方的地区

参考例句：

• He pointed his boat northward.他将船驶向北方。
• I would have a chance to head northward quickly.我就很快有机会去北方了。

11 axis   

n.轴，轴线，中心线；坐标轴，基准线

参考例句：

• The earth's axis is the line between the North and South Poles.地轴是南北极之间的线。
• The axis of a circle is its diameter.圆的轴线是其直径。

12 fixed   

adj.固定的，不变的，准备好的；(计算机)固定的

参考例句：

• Have you two fixed on a date for the wedding yet?你们俩选定婚期了吗？
• Once the aim is fixed,we should not change it arbitrarily.目标一旦确定，我们就不应该随意改变。

13 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

14 latitude   

n.纬度，行动或言论的自由(范围)，(pl.)地区

参考例句：

• The latitude of the island is 20 degrees south.该岛的纬度是南纬20度。
• The two cities are at approximately the same latitude.这两个城市差不多位于同一纬度上。

15 naval   

adj.海军的，军舰的，船的

参考例句：

• He took part in a great naval battle.他参加了一次大海战。
• The harbour is an important naval base.该港是一个重要的海军基地。

16 observatory   

n.天文台，气象台，瞭望台，观测台

参考例句：

• Guy's house was close to the observatory.盖伊的房子离天文台很近。
• Officials from Greenwich Observatory have the clock checked twice a day.格林威治天文台的职员们每天对大钟检查两次。

17 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。

18 atlas   

n.地图册，图表集

参考例句：

• He reached down the atlas from the top shelf.他从书架顶层取下地图集。
• The atlas contains forty maps,including three of Great Britain.这本地图集有40幅地图，其中包括3幅英国地图。

19 astronomer   

n.天文学家

参考例句：

• A new star attracted the notice of the astronomer.新发现的一颗星引起了那位天文学家的注意。
• He is reputed to have been a good astronomer.他以一个优秀的天文学者闻名于世。