VOA慢速英语2009-SCIENCE IN THE NEWS - Transgenic Monkeys Pro

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VOICE ONE:

This is SCIENCE IN THE NEWS, a program in VOA Special English. I'm Bob Doughty¹.

VOICE TWO:

And I'm Shirley Griffith. This week, we will tell about a study involving monkeys and a gene² from jellyfish. We will tell about an agreement to ban nine dangerous chemicals. We will also report on problems linked to cigarette smoking and alcoholic³ drinks.

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VOICE ONE:
　
Transgenic baby marmosets in an image published with the study that appeared in the journal Nature

Scientists in Japan say they have produced monkeys with a gene that gives the skin of the animals an unusual look. The skin is said to look bright green under ultraviolet lighting⁴.

The scientists say the monkeys represent an important step in how researchers study human disease. These marmosets are the first fully⁵ transgenic primates⁶. Primates are the biological group of animals that includes monkeys and apes. An animal that has received foreign genetic⁷ material is considered transgenic.

VOICE TWO:

For almost thirty years, researchers have used transgenic mice to carry out biomedical research. To produce these animals, researchers inject fertilized⁸ mice eggs with foreign genes⁹, and then place them in the uterus of a female mouse. The specially¹⁰ chosen genes are then expressed in some of the mouse's babies.

Transgenic mice help researchers study the appearance and treatment of human diseases. But mice are not as helpful as primates are for studying the behavior of human diseases.

VOICE ONE:
　
The hands of one of the transgenic marmosets as seen under ultraviolet light.

Scientists at Japan's Central Institute for Experimental Animals led the study that made the transgenic marmosets. The scientists say they injected a green glowing protein found in jellyfish into fertilized marmoset eggs. They chose this gene because it is easy to see with a florescent light.

Four of the five marmosets born as part of the experiment carried the foreign gene in several kinds of tissue. The fifth only carried the green protein in its placenta tissue at birth. Two of the animals later showed the foreign gene in their reproductive cells. This means they would pass on the gene for the green protein to their young.

VOICE TWO:

Later, a male transgenic marmoset reproduced and passed on the green gene to a baby. This is the first time scientists have successfully passed on a foreign gene to a future generation. And, it means that transgenic marmosets can be produced from breeding instead of by the lengthy¹¹ process of injecting fertilized eggs.

The scientists say the marmosets could one day be easily produced for medical research. They could be used to study conditions like Parkinson's disease and Lou Gehrig's disease. A report about the experiment was published last month in Nature magazine.

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VOICE ONE:

Officials from more than one hundred sixty governments have agreed to ban production of nine of the world's most dangerous chemicals. The agreement was announced last month at a United Nations conference in Switzerland.

The chemicals are joining twelve other substances that are already banned under a treaty known as the Stockholm Convention. The treaty was signed in two thousand one.

VOICE TWO:
　
Donald Cooper speaks during a United Nations conference in Geneva, Switzerland in May

The Stockholm Convention governs some kinds of industrial chemicals and pesticides¹² -- products meant to kill insects. These substances can damage the human nervous system and natural defenses against disease. They have also been linked to cancer, reproductive disorders¹⁴ and interfere¹⁵ with normal child development. The substances can also kill people.

Donald Cooper is Executive Secretary of the Stockholm Convention. He says the substances are especially dangerous because they travel through the air and stay in the atmosphere, soil and water. It takes many years for them to weaken. Mister Cooper says the substances build up in the cells of plants, animals and human beings.

VOICE ONE:

One of the newly banned chemicals is perflurooctane sulfonic acid, or PFOS. It is found in electrical parts and fire-fighting products. Another banned chemical is the pesticide¹³ Lindane. It is used in some areas as a treatment for head lice.

The governments at the U.N. conference also reached a decision on another pesticide, DDT. They said they want DDT banned, but recognize that some countries use it to protect people from diseases like malaria¹⁶. The governments said they will consider a plan that supports safer, effective choices to DDT. And, they hope to ban its use by two thousand ten.

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VOICE TWO:

Chronic¹⁷ obstructive pulmonary disease, also known as C.O.P.D., blocks airflow through the lungs. It makes breathing difficult. The leading cause is cigarette smoking. America's National Institutes of Health says the damage to the lungs cannot be repaired and there is no cure.

Dawn DeMeo is an assistant professor at Harvard Medical School in Massachusetts.

DAWN DeMEO: "By two thousand and twenty, C.O.P.D. will likely be the third leading cause of death across the world."

C.O.P.D. is a new name for emphysema and chronic bronchitis. These are the two most common forms of the disease. Many people with C.O.P.D. have both of them.

VOICE ONE:

Doctor DeMeo wrote about a study by a team from Harvard's Brigham and Women's Hospital and the University of Bergen in Norway. The study adds to findings that women may be more at risk than men for the damaging effects of smoking.

The team examined results from a Norwegian study of more than nine hundred people with C.O.P.D. Inga-Cecilie Soerheim also wrote about the team's findings. She says they show that women suffered the same severity of C.O.P.D. as men. But, the female smokers¹⁸ were younger and had smoked a lot less.

VOICE TWO:

The team also looked at two groups among the people in the study. These were people under the age of sixty and those who had smoked for less than twenty years. In both cases, women had more severe C.O.P.D. and a greater loss of lung function than men.

The study was presented last month to the American Thoracic Society.

Doctor Soerheim says there are several possible explanations why women may be more at risk from the effects of cigarette smoke than men. Women have smaller airways¹⁹, she says, so each cigarette may do more harm. Also, there are differences between males and females in the way the body processes cigarette smoke. And, she says, genes and hormones²⁰ could also play an important part.

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VOICE ONE:
　
A wine-tasting near Beijing, China

Finally, a listener in Taiwan wrote to ask why his face turns red when he drinks alcohol. This effect called facial flushing is a common reaction to alcohol among East Asians. It affects an estimated thirty-six percent of Japanese, Chinese and Koreans.

For many people, even a little alcohol can cause unpleasant effects. Most commonly, their face, neck and sometimes their whole body turns red. People might also feel sick to their stomach and lightheaded. They might experience a burning sensation, increased heart rate, shortness of breath and headaches.

The cause is a genetic difference that some people are born with. It prevents their bodies from processing alcohol the way other people do. But the effects might be more serious than just a red face. Researchers have warned of a link between this condition and an increased risk of cancer of the esophagus from drinking alcohol.

VOICE TWO:

A report about facial flushing appeared recently in PLoS Medicine, a publication of the Public Library of Science. The report says the more alcohol that persons with this deficiency drink, the greater their risk. It estimates that at least five hundred forty million people have the deficiency.

Esophageal cancer is one of the deadliest cancers. It can be treated when found early. But once it grows the chances of survival drop sharply.

VOICE ONE:

Philip Brooks²¹ is a researcher at America's National Institute on Alcohol Abuse and Alcoholism. Doctor Brooks says it is important to educate people about the link between the alcohol flushing effect and esophageal cancer. He says doctors should ask East Asian patients about their experiences with facial flushing after drinking alcohol. Those with a history of it should be advised to limit their alcohol use. They should also be warned that cigarette smoking works with the alcohol in a way that further increases the risk of esophageal cancer.

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VOICE TWO:

This SCIENCE IN THE NEWS was written by Lawan Davis, Dana Demange and June Simms. Our producer was Brianna Blake. I'm Shirley Griffith.

VOICE ONE:

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