SCIENCE IN THE NEWS #2128 - DigestBy StaffThis is Sarah Long.And this is Bob Doughty with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Today we tell about a man who can speak normally after receiving the first successful voice box transplant operation. We tell about a deadly form of skin cancer. And we tell about a dinosaur with feathers.
A patient whose voice box was destroyed in an accident can now speak normally. Three years ago, Timothy Heidler of Duncansville, Pennsylvania, had the first successful larynx transplant operation ever reported. During this operation he received the voice box of a man who had died. Mr. Heidler was forty years old when he received his new larynx. Doctors at the Cleveland Clinic in Cleveland, Ohio performed the operation. The New England Journal of Medicine recently reported about the operation and recovery.Before receiving the new larynx, Mr. Heidler had not spoken normally since Nineteen-Seventy-Eight. That was when he was involved in a motorcycle accident. The accident crushed his larynx. He could make sounds only by using a tone-producing device. His lips and tongue moved the device to form words. But the results were poor. He said he sounded like a robot.
Mr. Heidler lived for twenty years with this extremely limited communication. Then he heard about Marshall Strome of the Cleveland Clinic. Doctor Strome had been working for ten years to develop a larynx transplant operation. By Nineteen-Ninety-Eight he felt ready to perform the operation.Doctor Strome warned Mr. Heidler that the operation might not help him. The doctor said it might even kill him. But Mr. Heidler decided to have the operation.
Clinic doctors then searched for six months for the right larynx for the transplant operation. Finally they chose one from a man who had died suddenly of a stroke. The operation lasted twelve hours. Doctor Strome and his team gave Mr. Heidler a new larynx, throat, nerves and part of a trachea or breathing tube. Three days later, Mr. Heidler was able to say "hello " and "hi, Mom! " At first his voice sounded rough. But over time it has become normal.The New England Journal of Medicine says Mr. Heidler faced several problems during recovery. He could not swallow after the operation. He had to wait for nerves in his throat to heal. But after three months he could eat anything he wanted. Mr. Heidler must take powerful drugs to prevent his body from rejecting the new organ. He will have to do this all his life. These drugs increase the risk of liver and kidney damage, diabetes and one kind of cancer. But he has avoided one of the biggest risks of transplant surgery. He has not suffered an infection.
Doctors still plan to close a hole in his neck that was opened to aid breathing. For now, Mr. Heidler must cover the hole with his finger when he speaks. But his voice is deep and clear. He also is able to sing.
Sometimes Mr. Heidler shares details of his operation with people who cannot talk. In the United States alone, thousands of people have had their voice boxes removed because of cancer.
Now Doctor Strome says he is ready to perform a second larynx transplant operation. He is seeking someone whose larynx has been removed because of cancer.
((MUSIC BRIDGE))You are listening to the Special English program SCIENCE IN THE NEWS on VOA. This is Bob Doughty with Sarah Long in Washington.
When the weather is warm and sunny, people around the world spend more time outside. However, doctors have been warning for years that being in the sun for too long can burn the skin. It can also cause serious health problems, including skin cancer.
The World Health Organization says two-hundred-thousand cases of the most serious kind of skin cancer, malignant melanoma, develop each year. Malignant melanoma begins in body cells that produce a brown color. It usually first grows in a small dark area of skin called a mole. Melanoma most often is recognized as a dark area with an unusual shape.An operation to remove the cancerous cells can cure melanoma if the cancer has not spread. Doctors treat melanoma that has spread with chemotherapy. The drugs kill any cancer cells that were not removed in the operation. Radiation also may be used to kill cancerous cells and reduce the size of any cancerous growths.
The five-year survival rate for melanoma that has spread to the lymph nodes is thirty to forty percent. It is only twelve percent if the cancer has spread to other organs.Doctors say too much sunlight can cause melanoma. This is especially true for people who have light skin and were burned by the sun when they were young. Some people are more likely than others to develop melanoma. These include people whose family members had the disease. They also include people who have a large number of moles on their bodies.
Doctors say people should always protect their skin from sunlight. They should wear a hat and protective clothing. They should use a sun protection liquid. Doctors also say everyone should examine their bodies often for any changes in moles or the presence of new ones. They should go to a doctor if any mole has an unusual shape or if it has several different colors. Another warning sign of melanoma is a mole that is larger than six millimeters across.
((MUSIC BRIDGE))A debate has continued in the scientific community concerning the ancestors of modern birds. Some scientists believe birds developed from the ancient creatures called dinosaurs. Others believe birds developed separately.
A recent discovery seems to support the idea that birds developed from dinosaurs. Nature magazine has published a report by Chinese and American researchers. It describes the first clear evidence of a dinosaur with feathers. Ji Qiang of the Chinese Academy of Geological Sciences in Beijing and Mark Norell of the American Museum of Natural History in New York wrote the report.Fossils are the mineral remains of bones buried millions of years ago. The fossil of a feather-covered dinosaur was discovered in Liaoning Province in northeastern China. Several fossils of dinosaurs with feathers have been found in this area of China. But it is not always easy to confirm fossil discoveries.
Last year, we reported that a fossil dinosaur with feathers was found to be false. But, this most recent discovery appears to be confirmed.
The dinosaur was about a meter long. It walked on two legs and had a feather-like covering all over its body. The small dinosaur did not have wings and could not fly. But some of its bone structure was similar to that of birds. The animal lived about one-hundred-thirty-million years ago.Hans-Dieter Sues of the Royal Ontario Museum in Toronto, Canada says the fossil evidence shows that non-flying dinosaurs had a feather covering. Mr. Sues says the most recent fossils provide strong evidence that birds developed from dinosaurs.
Both Chinese and American researchers now believe that feathers developed to keep dinosaurs warm. They believe that some dinosaurs may have been warm-blooded like mammals and birds are today. For many years, paleontologists studying dinosaurs have thought that some dinosaurs may have been warm-blooded. Now the confirmed discovery of a non-flying dinosaur with feathers appears to support that theory.
The theory that feathers covered many dinosaurs requires a great change in the way we imagine those ancient creatures. In the Latin language, "dinosaur" means "terrible lizard." Instead, dinosaurs may have looked like terribly large birds.
This SCIENCE IN THE NEWS program was written by Jerilyn Watson, Nancy Steinbach and Mario Ritter. It was produced by Caty Weaver. This is Bob DoughtyAnd this is Sarah Long. Join us again next week for more news about science in Special English on the Voice of America.