VOA慢速英语2010年-SCIENCE IN THE NEWS - Osteoporosis Inc

FAITH LAPIDUS: This is SCIENCE IN THE NEWS, in VOA Special English. I’m Faith Lapidus.

BOB DOUGHTY¹: And I’m Bob Doughty. Today we tell about osteoporosis, a disease that can make bones weak so they break easily.

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FAITH LAPIDUS: A new study shows that binge drinking by teenagers may increase the possibility of osteoporosis in later life. Researchers in the United States say drinking a lot of alcohol over a short period may influence genes³ involved in bone formation.

Bone biologist John Callaci led a team studying the effects of alcohol on young rats. He teaches and leads a research laboratory at Loyola University’s medical school in the state of Illinois. His team’s findings appear in “Alcohol and Alcoholism,” a publication of Oxford⁴ University Press.

BOB DOUGHTY: Binge drinkers swallow large amounts of alcohol over a short period. One definition says binge drinking happens when a woman has at least four alcoholic⁵ drinks in a hurry. For men, binge drinking can mean five drinks in a short time.

America’s Substance Abuse and Mental Health Services Administration says binge drinking can begin when a person is about thirteen years old. It says binge drinking generally worsens in young adulthood⁶, and slowly decreases after that.

Professor Callaci’s team studied adolescent laboratory rats to learn the effects of binge drinking on their genes. The team injected alcohol into the animals. The injections resulted in a blood alcohol level of zero-point-two-eight. In many American states, a person is legally drunk when the level of alcohol in the blood reaches zero-point-zero-eight.

FAITH LAPIDUS: Some rats received a daily injection of alcohol for three days. The researchers say the alcohol affected⁷ about three hundred bone-related genes in those rats. The other rats received alcohol over a similar three-day period, but the injections continued for four consecutive⁸ weeks. In these rats, one hundred eighty genes were affected.

The injections added ribonucleic acid, also known as RNA, to the genes of some rats. In the other rats, the RNA in the genes decreased. Ribonucleic acid tells the gene² how to make proteins, the substances necessary for bones and other tissues. These changes interfered⁹ with the pathway of molecules¹⁰ responsible for building bones and keeping them strong.

Professor Callaci says one of the most worrying findings came thirty days after the injections stopped. At that time, the animals still showed differences in the way their genes were expressed. Thirty days of a rat’s life are about the same as three human years.

Professor Callaci says it is not necessarily true that what happens to rats’ genes will happen to human genes. But he says the findings suggest that young people’s binge drinking could signal problems in their future.

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BOB DOUGHTY: Bones are living tissue. Tissues continually break down and then replace themselves. However, as people get older, more bone breaks down, than gets replaced. The result is that small spaces inside the bone get larger. The shell of the bones also gets thinner.

The word osteoporosis means porous¹¹ bones, or bones that are not solid enough. The disease harms bones by removing calcium¹² and other minerals from tissue. The National Osteoporosis Foundation says eight of every ten osteoporosis patients are women. It says the disease is most common in Caucasian women over age fifty.

Two years ago, the National Osteoporosis Foundation suggested that doctors extend their list of persons to watch for osteoporosis. The additions included Latina, African-American, Asian and other women. The group also called attention to the fact that men can also suffer from osteoporosis.

FAITH LAPIDUS: Before people develop osteoporosis, they have a condition called osteopenia. Treatment can prevent this condition from becoming osteoporosis. Doctors can identify osteoporosis and osteopenia by measuring the mineral density¹³ of a person’s bones. In this case, density means the strength of the bones.

Bone mineral density can be measured in a number of ways. Doctors use the tests to examine the hip¹⁴ and spine¹⁵, or backbone¹⁶. The National Osteoporosis Foundation says a test called Dual-energy X-ray absorptiometry, or DXA, is the best test for osteoporosis. DXA uses radiation from x-rays. The patient does not get much radiation from the process, which lasts only a few minutes.

BOB DOUGHTY: Another way to measure bone-density is called peripheral¹⁷ bone mineral density testing. It is often used in the United States to show people if they are in danger of osteoporosis. A moveable machine does the test.

Medical testing companies sometimes perform the exam at an office or other place of business. The exam costs less than the DXA. Peripheral testing measures only one part of the body. Usually that place is the wrist, the heel, or the bones between finger joints¹⁸.

FAITH LAPIDUS: If the testing device is in good condition, it probably will give satisfactory results. But what if the patient has normal bones in the tested areas, but not in others? A person could appear normal on the test. But she still might have osteoporosis in her backbone or hips¹⁹.

Bone mineral density in the spine decreases first. A woman’s bone mineral density becomes about the same in all parts of her body after she is seventy years old. The lower-cost test may not give complete answers. But it can warn that osteoporosis threatens or has started.

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BOB DOUGHTY: The National Osteoporosis Foundation has advised several steps toward the goal of healthy bones. Its experts say get enough calcium and vitamin D. They say do not smoke or drink too much alcohol. Talk to your doctor about bone health and a possible bone mineral density test.

The National Osteoporosis Foundation says people over fifty should get one thousand two hundred milligrams of calcium every day. It also says this age group should get eight hundred to one thousand International Units of Vitamin D. It says Vitamin D-Two and Vitamin D-Three are both good for bones.

FAITH LAPIDUS: Milk and milk products contain calcium. So do fish with soft bones, like salmon²⁰, and dark green leafy vegetables. Some orange juice, bread and cereals may have calcium added.

Some people take pills containing calcium. However, be careful about how much calcium you take. You should not have more than two thousand five hundred milligrams a day. That total includes calcium from food and all other sources. Too much calcium can cause problems like kidney stones.

Vitamin D absorbs, or takes up, calcium. Fish, cereal and milk are rich in Vitamin D. If you spend at least fifteen minutes a day in the sun without a product to block the sun’s radiation, you probably get enough Vitamin D.

BOB DOUGHTY: Several kinds of drugs treat osteoporosis. America’s Mayo Clinic medical centers say bisphosphonates are the most popular. Fosamax, Actonel and Boniva are products of this family of drugs.

Doctors who treat osteoporosis patients say physical exercise can help the bones. For active people, lifting weights or playing tennis, slow running and dancing can be helpful.

Some people who have not exercised worry about the effect of exercise on their joints, especially the knees. They are afraid exercise might cause osteoarthritis. In that condition, connective tissue around the bones wears down. One study in The Netherlands shows that might be possible. The results linked knee osteoarthritis to high mechanical strain -- activities that are hard on joints.

FAITH LAPIDUS: Another study found that regular physical exercise does not harm joints. Scientists from Germany and the United States considered earlier research on the effect of exercise on joints. They did not find a link between normal exercise and knee osteoarthritis.

If you are still worried about exercise for osteoporosis, try taking a walk. The Mayo Clinic says walking helps your bones. However, you have to do it correctly. The Mayo Clinic says hold your head high. Straighten your back and neck as much as possible. Tighten²¹ the chest muscles. As you move along, let your shoulders and arms move freely and naturally.

Walking raises the levels of chemicals in the brain known as endorphins. They reduce pain and make you feel happier.

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BOB DOUGHTY: This SCIENCE IN THE NEWS was written by Jerilyn Watson. Our producer was June Simms. 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 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。

3 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

4 Oxford   

n.牛津（英国城市）

参考例句：

• At present he has become a Professor of Chemistry at Oxford.他现在已是牛津大学的化学教授了。
• This is where the road to Oxford joins the road to London.这是去牛津的路与去伦敦的路的汇合处。

5 alcoholic   

adj.（含）酒精的，由酒精引起的；n.酗酒者

参考例句：

• The alcoholic strength of brandy far exceeds that of wine.白兰地的酒精浓度远远超过葡萄酒。
• Alcoholic drinks act as a poison to a child.酒精饮料对小孩犹如毒药。

6 adulthood   

n.成年，成人期

参考例句：

• Some infantile actions survive into adulthood.某些婴儿期的行为一直保持到成年期。
• Few people nowadays are able to maintain friendships into adulthood.如今很少有人能将友谊维持到成年。

7 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

8 consecutive   

adj.连续的，联贯的，始终一贯的

参考例句：

• It has rained for four consecutive days.已连续下了四天雨。
• The policy of our Party is consecutive.我党的政策始终如一。

9 interfered   

v.干预( interfere的过去式和过去分词 )；调停；妨碍；干涉

参考例句：

• Complete absorption in sports interfered with his studies. 专注于运动妨碍了他的学业。 来自《简明英汉词典》
• I am not going to be interfered with. 我不想别人干扰我的事情。 来自《简明英汉词典》

10 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

11 porous   

adj.可渗透的，多孔的

参考例句：

• He added sand to the soil to make it more porous.他往土里掺沙子以提高渗水性能。
• The shell has to be slightly porous to enable oxygen to pass in.外壳不得不有些细小的孔以便能使氧气通过。

12 calcium   

n.钙(化学符号Ca)

参考例句：

• We need calcium to make bones.我们需要钙来壮骨。
• Calcium is found most abundantly in milk.奶含钙最丰富。

13 density   

n.密集，密度，浓度

参考例句：

• The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
• The region has a very high population density.该地区的人口密度很高。

14 hip   

n.臀部，髋；屋脊

参考例句：

• The thigh bone is connected to the hip bone.股骨连着髋骨。
• The new coats blouse gracefully above the hip line.新外套在臀围线上优美地打着褶皱。

15 spine   

n.脊柱，脊椎；(动植物的)刺；书脊

参考例句：

• He broke his spine in a fall from a horse.他从马上跌下摔断了脊梁骨。
• His spine developed a slight curve.他的脊柱有点弯曲。

16 backbone   

n.脊骨，脊柱，骨干；刚毅，骨气

参考例句：

• The Chinese people have backbone.中国人民有骨气。
• The backbone is an articulate structure.脊椎骨是一种关节相连的结构。

17 peripheral   

adj.周边的，外围的

参考例句：

• We dealt with the peripheral aspects of a cost reduction program.我们谈到了降低成本计划的一些外围问题。
• The hotel provides the clerk the service and the peripheral traveling consultation.旅舍提供票务服务和周边旅游咨询。

18 joints   

接头( joint的名词复数 )； 关节； 公共场所（尤指价格低廉的饮食和娱乐场所） （非正式）； 一块烤肉 （英式英语）

参考例句：

• Expansion joints of various kinds are fitted on gas mains. 各种各样的伸缩接头被安装在煤气的总管道上了。
• Expansion joints of various kinds are fitted on steam pipes. 各种各样的伸缩接头被安装在蒸气管道上了。

19 hips   

abbr.high impact polystyrene 高冲击强度聚苯乙烯，耐冲性聚苯乙烯n.臀部( hip的名词复数 )；[建筑学]屋脊；臀围（尺寸）；臀部…的

参考例句：

• She stood with her hands on her hips. 她双手叉腰站着。
• They wiggled their hips to the sound of pop music. 他们随着流行音乐的声音摇晃着臀部。 来自《简明英汉词典》

20 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？

21 tighten   

v.(使)变紧；(使)绷紧

参考例句：

• Turn the screw to the right to tighten it.向右转动螺钉把它拧紧。
• Some countries tighten monetary policy to avoid inflation.一些国家实行紧缩银根的货币政策，以避免通货膨胀。