Science News Digest
This 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 pig organs designed for use in humans. We tell about a gene for grooming. We tell about a new way to tell if someone is lying. And we tell about the death of the world's oldest man.
Two biotechnology companies say they have developed pigs with organs designed for use in human transplant operations. They are the first pigs genetically engineered to keep their organs from being rejected by humans.
Pigs carry a gene that causes production of an enzyme. The enzyme puts sugar molecules on the surface of pig organs. The human body's defense system recognizes the organ as foreign and rejects it. The idea was to create pigs that lacked this gene. The scientists genetically changed a pig embryo, then copied it in a process known as cloning.
The researchers believe their work is the best hope for people waiting for an organ transplant operation. More than seventy-thousand people in the United States alone need such an operation to replace organs that no longer work. Scientists consider pigs to be the best animals to provide organs for people. This is because the organs are similar.
The two biotechnology companies developed pigs of different sizes. The first four genetically engineered pigs were born in September and October. The pigs are smaller than normal. Researchers at the University of Missouri in Columbia developed these pigs. They worked with the Immerge BioTherapeutics Company of Charlestown, Massachusetts.
The five other pigs are of normal size. They were born in December at the P-P-L Therapeutics Company research center in Blacksburg, Virginia. P-P-L is the Scottish company that helped create the first cloned animal, Dolly the sheep, a few years ago. The company says it wants to use the pigs as part of its program to seek a cure for the disease diabetes.
It is very difficult to create genetically engineered pigs. The Missouri group used millions of pig cells. The researchers made more than three-thousand copies of pig embryos. They placed the embryos in twenty-eight mother pigs. Seven baby pigs were born. Four survived. However, some show evidence of heart and blood vessel problems.
Scientists say that creating these pigs was an important step in solving a major problem in transplanting organs from animals to humans.
However, scientists say much more work needs to be done to improve this process. Researchers also must solve the possible problem that pig organs could spread deadly viruses to people. Scientists expect other genes will need to be changed before it is safe to place a pig organ in a human being.
In addition, the idea of using pig organs for people raises serious moral questions about the scientific use of animals. Animal rights activists strongly oppose this research.
It is important to most people to look good. For example, we wash our hands and face. We comb our hair. This is called grooming. Grooming is important for animals too. They clean themselves and remove harmful organisms from their bodies.
Researchers at the University of Utah School of Medicine have found a group of genes that might be responsible for grooming activity. The study was led by Mario Capecchi. It appeared in the publication Neuron.
The researchers examined a gene that all animals have. The gene is very important in the early stages of development. It helps make an animal's bones, heart, and other organs. The researchers created a group of mice that lacked the gene. The mice seemed to develop normally.
However, after three weeks, the researchers noted that the mice had missing hair and open wounds. The mice were grooming themselves too much. They were spending two times as long as healthy mice to get themselves clean. They licked and bit themselves in some places until their hair was gone.
The researchers wanted to find out if the extreme grooming was a result of some other problem the mice had. They placed normal mice in the same cage. The genetically changed mice continued to bite their hair until it was gone in some places. They also did this to the normal mice that had been placed in the cage with them.
Mario Capecchi says people have almost all the same genes as mice. He says the discovery of a grooming gene could lead to better treatment of some disorders in people. Some people with these disorders spend too much time grooming. For example, they wash their hands until they bleed.
Scientists say they have developed a camera that can help identify when a person is not telling the truth. The new camera measures the heat released by a person's face. The scientists say the camera correctly identified lying in more than eighty percent of the people they tested. They say the device might one day be used in high-level security operations at airports or border crossings.
James Levine of the Mayo Clinic in Rochester, Minnesota led the study. The scientists based their work on the theory that people who plan to trick someone release physical or chemical signals.
The researchers worked with scientists at Honeywell Laboratories to develop the new, heat-imaging technology. Doctor Levine says the camera is designed to measure small changes in the body. He notes that the flow of blood to the surface of the skin increases around the eyes when a person lies.
The scientists used twenty people to test the heat-sensing camera. Eight of the people took part in a crime that was not real. They attacked a human-like object and stole money from it. They were asked to lie and say they were innocent of the crime. The twelve other people in the study were told nothing about the make-believe crime.
The researchers used the special camera while questioning the twenty people about the crime. The camera showed that six of the eight people who carried out the crime had increased heat around their eyes when they lied.
Eleven of the twelve people who knew nothing about the crime were correctly identified as innocent. When they told the truth, the area around their eyes remained cool. Lie detection experts say the new camera could be used without suspects knowing they are being watched.
The world's oldest man died last month. Antonio Todde lived on the Italian island of Sardinia. Mr. Todde was one-hundred-twelve years old. He was less than three weeks away from his one-hundred-thirteenth birthday.Mr. Todde cared for farm animals in the mountains almost all his life. He often said that drinking a glass of red wine every day helped him live to an old age.
His long life and that of other very old Sardinians is the subject of a study. Luca Deiana of Sassari University is directing the study. Professor Deiana and his team identified more than two-hundred-twenty Sardinians who were centenarians -- one-hundred years old or older.
The study has produced two major findings. The first is Sardinia's extremely high number of centenarians. The island has about one-hundred-thirty-five centenarians for every one-million people. In other western countries, the average is about seventy-five centenarians for every one-million people.
The second major finding is an unusual rate of female to male centenarians. Sardinia has two women centenarians for every male centenarian. In central Sardinia there are equal numbers of female and male centenarians. Studies in other parts of the world have shown a much higher percentage of female centenarians. Study leaders say there is no single reason why people in Sardinia live so long. They believe the answer is a combination of genetic and environmental conditions.
This SCIENCE IN THE NEWS program was written by Nancy Steinbach, Lawan Davis and George Grow. It was produced by Caty Weaver. This is Bob Doughty. And this is Sarah Long. Join us again next week for more news about science in Special English on the Voice of America.