SCIENCE IN THE NEWS #2071 - Digest

By StaffThis is Bob Doughty.And this is Sarah Long with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in Science. Today, we tell about a successful gene therapy treatment. We tell about the discovery that cloned cows have very young cells. And we tell about a new study that shows why people should eat eating healthy foods.

Scientists in France say they have treated babies born with a rare genetic disorder in which the body cannot make immune cells to fight disease. The researchers say the experimental gene therapy treatment appears to have restored the immune systems of the children. The scientists report that the children appear to be in good health almost one year after the treatment. Many other researchers praised the experiment. They say it is the first true evidence that gene therapy can be successful.

Gene therapy is a method of treating diseases by giving people new genes. Researchers have tested gene therapy in thousands of patients over the past ten years. However, most treatments have failed.The new findings were reported in Science magazine. Researchers at the Necker children's hospital in Paris treated two babies with a condition called severe combined immune deficiency. Babies born with the disease have a single defective gene that prevents them from producing cells that fight against infection. Babies with the disease can die from organisms that do little harm to most people. Many children born with the condition must live in large plastic containers to protect them against disease.The French researchers removed the substance inside the bones of the babies called bone marrow. Bone marrow contains special stem cells that produce a supply of immune system cells. The scientists mixed the stem cells with a genetically-engineered virus carrying a healthy copy of the immune system gene that the babies needed.

Then the researchers injected the treated stem cells with the healthy gene into the babies' bodies. The scientists hoped the repaired stem cells would settle into the bone marrow and produce immune system cells for the rest of the children's lives.The researchers soon saw results from the treatment. The babies started producing immune system cells to fight against infection. Three months later, the babies went home from the hospital. Each has been home for almost one year. The researchers say both children have immune cells comparable to healthy children their age.

The children's natural immune systems reacted normally when they were given vaccines to protect against polio and other diseases. Neither child has suffered any side effects from the gene therapy. The French researchers now say they have now successfully treated a third baby with the immune disorder.Alain Fischer performed the successful gene therapy treatment. Doctor Fischer began working on gene therapy for severe combined immune deficiency disease in Nineteen-Ninety-Three as soon as the defective gene was identified. He studied the treatment for six years in mice and in the laboratory.

The successful treatment comes at an important time. Five years ago, a United States government committee criticized researchers for attempting too many gene therapy studies. Last year, an American boy died in a different gene therapy experiment at the University of Pennsylvania in Philadelphia. His death led to widespread criticism that many gene therapy studies were poorly supervised.You are listening to the Special English program SCIENCE IN THE NEWS on VOA. This is Sarah Long with Bob Doughty in Washington.

American scientists recently produced six copies of a cow by cloning. Cloning is creating an exact copy of an animal using its own cells. Now the scientists say some of the cells from the cloned cows appear even younger than cells from normal cows of the same age.

The new work suggests that some cells can be strengthened through cloning. It also suggests that cloning could provide youthful cells for a number of different uses, including transplant operations or treatment of some diseases.

Researchers at a company called Advanced Cell Technology in Worcester, Massachusetts carried out the new study. Their findings are reported in the publication Science.Scientists say the findings are surprising. They were different from a discovery about Dolly the sheep. Dolly was the first mammal to be cloned using an adult cell three years ago. Last year, researchers found that Dolly's cells appear to be older than her age. The researchers found evidence that Dolly's cells were the same age as those of the six-year-old sheep from which she was cloned.

The researchers made the discovery by examining telomeres, the structures on the ends of chromosomes. Chromosomes carry genetic information inside cells. Each time a cell divides, the telomeres become shorter.Dolly the sheep has abnormally short telomeres. However, scientists say cells from the six cow clones have very long telomeres. They were longer than telomeres of normal cows born at the same time. The telomeres of a one-year-old cloned cow were even longer than those of a newborn cow. Why are the cells from Dolly and the cow clones so different? The scientists suggest a number of reasons, including differences in the ways the animals were produced.

For example, the cows were cloned from older cells. These cells had divided many times and had survived for a long time. The scientists say this could explain why the cloned cows seemed to have longer-living cells.

Other researchers praised the findings. But they note that having long telomeres does not guarantee that the cloned cows would live longer. They say many things can influence how long an animal lives.

((MUSIC BRIDGE))A new American study suggests that women who eat many kinds of healthy foods may greatly lower their risk of dying from cancer, heart disease or stroke. The study found that these women were thirty percent less likely to die during a six-year period than women with the most unhealthy diets.

The findings may sound like old news. However, the researchers who organized the study say most earlier studies examined the health effects of a limited number of foods or vitamins. They say those studies failed to examine the combined effect of all the foods people eat.The new study examined the diets of more than forty-two-thousand older American women. The findings were reported in the Journal of the American Medical Association.

The researchers compared the foods the women ate to the United States government's "food pyramid" guide. The Department of Agriculture established the guide eight years ago. Health experts and teachers use the food pyramid to show Americans which foods they should eat every day.The guide has three sides and is shaped like a triangle or pyramid. The bottom of the food pyramid is wide. It shows pictures of foods that adults should eat the most of every day. These include fruits, vegetables and bread.

The middle of the pyramid is less wide. It shows foods that should be a smaller part of an adult's diet. These include milk products, meat, fish and eggs. The top of the pyramid is narrow. It shows foods that adults should eat in the smallest amounts. These include fats, oils and sweets.

Arthur Schatzkin of the National Cancer Institute helped organize the study. Doctor Schatzkin notes that the findings do not prove that a healthy diet alone is responsible for a longer life. He says the people who eat the healthiest food are probably doing other healthy things, such as exercising and not smoking.

This SCIENCE IN THE NEWS program was written by George Grow. This is Sarah Long.And this is Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.

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