Transgenic Monkeys Produced in Japan
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This is SCIENCE IN THE NEWS, a program in VOA Special English. I'm Bob Doughty. And I'm Shirley Griffith.
This week, we will tell about a study involving monkeys and a gene from jellyfish. We will tell about an agreement to ban nine dangerous chemicals. We will also report on problems linked to cigarette smoking and alcoholic drinks.
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 lighting.
The scientists say the monkeys represent an important step in how researchers study human disease. These marmosets are the first fully transgenic primates. Primates are the biological group of animals that includes monkeys and apes. An animal that has received foreign genetic material is considered transgenic.
For almost thirty years, researchers have used transgenic mice to carry out biomedical research. To produce these animals, researchers inject fertilized mice eggs with foreign genes, and then place them in the uterus of a female mouse. The specially 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.
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 fluorescent 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.
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 lengthy 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.
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.
The Stockholm Convention governs some kinds of industrial chemicals and pesticides -- 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 disorders and interfere 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. Mr. Cooper says the substances build up in the cells of plants, animals and human beings.
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 pesticide 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 malaria. 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.
Chronic 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.
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 smokers were younger and had smoked a lot less.
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 airways, 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 hormones could also play an important part.
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.
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.
Philip Brooks 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.
This SCIENCE IN THE NEWS was written by Lawan Davis, Dana Demange and June Simms. Our producer was Brianna Blake. I'm Shirley Griffith. And I'm Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.