VOA慢速英语2010年-SCIENCE IN THE NEWS - Scientists Seeki

FAITH LAPIDUS:

This is SCIENCE IN THE NEWS, in VOA Special English. I'm Faith Lapidus.

BOB DOUGHTY¹:

And I'm Bob Doughty. This week, we tell about the disease multiple sclerosis.

(MUSIC)

FAITH LAPIDUS:

Multiple sclerosis is not easy to say. Those who suffer from the disease may also have difficulty naming it. One sign of multiple sclerosis is losing the ability to speak clearly. It is estimated that more than two million five hundred thousand people worldwide suffer from multiple sclerosis, which also is called MS.

MS is a disease of the brain and spinal² cord. The cause of the disease is not known. In patients with MS, the covering of the nerves is destroyed. This temporarily blocks signals that pass through the nerves to the muscles of the body and back to the brain.

The disease especially affects the ability to see, the sense of touch and the use of the arms and legs. Most forms of MS are described as progressive. This means that the disease gets worse as time passes.

BOB DOUGHTY:

A file photo of a patient receiving treatment for MS

The central nervous system of the body includes the brain and the spinal cord. The system contains millions of nerve cells joined together by long thin fibers³, like wires. Electric signals start in nerve cells and travel along these fibers to and from the brain. A fatty substance called myelin covers and protects the fibers. Myelin works in the same way that protective coverings work on electric wires.

In patients with MS, the myelin becomes infected. It swells⁴, or grows larger, and loses its connection with the nerve fibers. As time passes, the unconnected myelin is destroyed. Hardened, scar tissue then forms over the nerve fibers. The process of hardening is called sclerosis. The word is from Latin and means scar. The many areas of hardened or scar tissue give the disease its name.

FAITH LAPIDUS:

In people with MS, when nerve signals reach a damaged area, some of the signals are blocked or delayed from traveling to or from the brain. This results in problems in different parts of the body. These problems may appear and then disappear, sometimes resulting in long periods when there are no problems at all. Or, they may happen more and more often and become worse. Doctors do not know what causes this process.

Experts say the disease affects women at least two times as often as men. And, they say, the average age of people found to have the disease is between twenty and fifty years old.

(MUSIC)

BOB DOUGHTY:

For years, doctors believed that the cause of multiple sclerosis was environmental. They believed this because most of those suffering from the disease lived in northern Europe and the northern half of the United States.

In recent years, however, doctors have changed their beliefs about the causes of MS. Studies support the theory that there are several causes, instead of a single environmental cause or genetic⁶ problem. The studies appear to show that genetic problems are involved in making people likely to get the disease.

The studies also appear to show that environmental causes like viruses or bacteria may be involved. However, researchers have not identified just what those causes might be. Another likely cause is a problem within the body's defenses against disease, when the defenses misunderstand signals and attack the body.

Recently, an American study showed that women who get plenty of vitamin D during pregnancy⁷ may be protecting their babies from developing MS later in life. Vitamin D is found in fortified⁸ milk and fatty fish like salmon⁹. Your body also produces the vitamin after contact between the skin and sunlight.

FAITH LAPIDUS:

Multiple sclerosis is different from many other diseases. The signs or symptoms of MS are not always the same. Sometimes, symptoms of the disease appear and then disappear for a long time. For example, one symptom is a lack of feeling in one part of the body or another.

Two other symptoms are muscle weakness and low energy levels. However, these also could be caused by other health problems that are not MS. Other symptoms include a loss of the ability to move normally or a loss of balance. A person suffering from MS also may have difficulty seeing well or speaking clearly.

BOB DOUGHTY:

Doctors who suspect a patient has MS must carry out tests and study the patient's history of health problems. MS symptoms can depend on where the nerve scars are in the central nervous system. And some of these signs are not always easy to see.

Magnetic Resonance¹⁰ Imaging is one way to tell if a patient has multiple sclerosis. The test, also known as MRI, involves studying the magnetic signals from all the cells in the body. An MRI can show if there are scars from MS along a patient's nerves. A doctor can use this test to tell if a patient might have the disease, as well as by studying the patient's medical history.

(MUSIC)

FAITH LAPIDUS:

There are four main kinds of multiple sclerosis. The first is called Relapsing-Remitting. About eighty-five percent of MS patients begin with this form of the disease. More than half of the patients have this form at any one time. These patients have one or two major MS-related problems every one to three years. Then they have periods with no signs of the disease.

The symptoms appear suddenly and last a few weeks or months before slowly disappearing. However, the symptoms may also become worse each time they appear.

BOB DOUGHTY:

The second kind of MS is called Primary Progressive. In this form, the signs of the disease appear and begin to grow worse, with no periods of disappearance¹¹. About ten percent of patients begin their struggle with the disease this way.

The third kind of MS is called Secondary Progressive. This form of the disease affects about fifty percent of those with the Relapsing-Remitting form of MS. It begins to affect them several years after they have had Relapsing-Remitting MS. When the disease changes to Secondary Progressive, the disease begins to grow worse.

The fourth kind of MS is called Progressive Relapsing. It is the worst form of multiple sclerosis. New signs of MS appear while existing ones grow worse. This form of the disease is rare.

(MUSIC)

FAITH LAPIDUS:

Scientists say multiple sclerosis does not appear to be passed from parents to children. Yet it does appear to be found in families. The National Multiple Sclerosis Society says one in every seven hundred fifty Americans is at risk of developing MS. But the risk rises to one in every forty people among those who have a close family member with the disease.

It does not appear that one gene⁵ is responsible for MS. Instead, several genes¹² may increase the possibility that a person will develop MS. Common viruses or bacteria may also increase the chances that some people will develop the disease.

BOB DOUGHTY:

There is no cure for multiple sclerosis. MS does not always result in severe disability. Many patients are able to live normal lives. The National Institute of Neurological Disorders¹³ and Stroke says some patients do well with no treatment at all. It notes that many medicines to treat the disease have serious side effects while some carry risks.

Several kinds of medicine are used to treat the symptoms. Some drugs reduce the swelling¹⁴ in nerve tissue. Drugs known as beta interferons also are used to treat MS. Interferons are genetically¹⁵ engineered copies of proteins found naturally in the body. These proteins help fight viral infections and help the body's defenses against disease.

FAITH LAPIDUS:

America's Food and Drug Administration has approved three forms of beta interferon for treatment of Relapsing-Remitting MS. The FDA also has approved a man-made form of myelin basic protein to treat this kind of MS. And, a treatment to suppress the body's defenses against disease was approved to treat severe cases of MS.

Last month, the FDA approved sales of dalfampridine extended release tablets to improve walking in MS patients. This is the first drug approved for this use.

Scientists are working to develop other treatments for MS. The National Multiple Sclerosis Society says more than one hundred studies are continuing around the world. Doctors are hopeful that new treatments will help patients with multiple sclerosis in the future.

(MUSIC)

BOB DOUGHTY:

This SCIENCE IN THE NEWS program was written by Oliver Chanler and Brianna Blake, who was also our producer. I'm Bob Doughty.

FAITH LAPIDUS:

And I'm Faith Lapidus. Join us again next week for more news about science in Special English on the Voice of America.

 

1 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。

2 spinal   

adj.针的，尖刺的，尖刺状突起的；adj.脊骨的，脊髓的

参考例句：

• After three days in Japan,the spinal column becomes extraordinarily flexible.在日本三天，就已经使脊椎骨变得富有弹性了。
• Your spinal column is made up of 24 movable vertebrae.你的脊柱由24个活动的脊椎骨构成。

3 fibers   

光纤( fiber的名词复数 )； （织物的）质地； 纤维，纤维物质

参考例句：

• Thesolution of collagen-PVA was wet spined with the sodium sulfate as coagulant and collagen-PVA composite fibers were prepared. 在此基础上，以硫酸钠为凝固剂，对胶原-PVA共混溶液进行湿法纺丝，制备了胶原-PVA复合纤维。
• Sympathetic fibers are distributed to all regions of the heart. 交感神经纤维分布于心脏的所有部分。

4 swells   

增强( swell的第三人称单数 )； 肿胀； （使）凸出； 充满（激情）

参考例句：

• The waters were heaving up in great swells. 河水正在急剧上升。
• A barrel swells in the middle. 水桶中部隆起。

5 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

6 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。

7 pregnancy   

n.怀孕，怀孕期

参考例句：

• Early pregnancy is often accompanied by nausea.怀孕早期常有恶心的现象。
• Smoking during pregnancy increases the risk of miscarriage.怀孕期吸烟会增加流产的危险。

8 fortified   

adj. 加强的

参考例句：

• He fortified himself against the cold with a hot drink. 他喝了一杯热饮御寒。
• The enemy drew back into a few fortified points. 敌人收缩到几个据点里。

9 salmon   

n.鲑，大马哈鱼，橙红色的

参考例句：

• We saw a salmon jumping in the waterfall there.我们看见一条大马哈鱼在那边瀑布中跳跃。
• Do you have any fresh salmon in at the moment?现在有新鲜大马哈鱼卖吗？

10 resonance   

n.洪亮；共鸣；共振

参考例句：

• Playing the piano sets up resonance in those glass ornaments.一弹钢琴那些玻璃饰物就会产生共振。
• The areas under the two resonance envelopes are unequal.两个共振峰下面的面积是不相等的。

11 disappearance   

n.消失，消散，失踪

参考例句：

• He was hard put to it to explain her disappearance.他难以说明她为什么不见了。
• Her disappearance gave rise to the wildest rumours.她失踪一事引起了各种流言蜚语。

12 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

13 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》

14 swelling   

n.肿胀

参考例句：

• Use ice to reduce the swelling. 用冰敷消肿。
• There is a marked swelling of the lymph nodes. 淋巴结处有明显的肿块。

15 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