Yearender 2000
By Nancy SteinbachThis is Bob Doughty.And this is Sarah Long with the VOA Special English program SCIENCE IN THE NEWS. Today, we tell about some of the major science stories of the year Two-Thousand.Earlier this year, two separate groups of scientists announced that they had found the correct order of all the chemical pieces in the genetic material that shapes human life.
One group includes researchers from the United States government, Britain, France, Germany, China and Japan. Their effort is called The Human Genome project. The other group includes scientists from the private company Celera Genomics (Suh-LAIR-uh Jeh-NO-Mix). Each group of researchers said they had produced a map of human genetic material, commonly known as D-N-A. The letters D-N-A represent deoxyribonucleic acid. Scientists call it the chemical of life. All of the D-N-A in the cells is called the genome.
Mapping the position of every human gene is an extremely important discovery. The map will provide a description of the structure of human genetic material. This structure includes more than three-thousand-million chemical pieces linked together.
Completing this human genetic map will permit scientists to study the mysteries of human health and disease. The discovery changes the way some diseases will be treated. It will help doctors develop treatments to fight disease on the level of cells and genes.
Officials of the National Human Genome Research Institute near Washington, D. C. say about ninety-two percent of the human genome map is complete. They say the scientists will continue working to link the parts together and find their meaning.
Both groups of researchers are expected to publish their findings early next year. The National Human Genome Research Institute will continue to work on the human genome to find out what all the genes are and what they do.
((MUSIC BRIDGE))Another major science story of this year is the spread of the animal sickness known as "Mad Cow Disease".
It got that name because cattle act strangely before they die. Its scientific name is Bovine Spongiform Encephalopathy, or B-S-E. Cattle suffering the disease develop holes in the brain. Experts believe the disease is caused by eating feed containing the remains of infected animals.
Scientists believe that eating beef from cattle infected with B-S-E may cause a similar incurable disease in people. The human disease is called Creutzfeldt-Jacob Disease. More than eighty people in Britain and two in France have died from the human form of the disease in recent years.
The connection between B-S-E and the human form of the disease was made in Britain in Nineteen-Ninety-Six. Thousands of cattle were destroyed as a result. British beef products were removed from most European markets. Most E-U members now permit the sale of British beef.
This year, Mad Cow Disease was discovered in Germany and Spain for the first time. And the number of reported cases of the disease increased in France. The disease has also been reported in Belgium, Italy and The Netherlands.
Earlier this month, agriculture ministers from the European Union met to take action against B-S-E. They approved measures to stop the spread of the disease and to help re-build public trust in European beef products.
The officials agreed not to permit cattle over thirty months old to be sold as food unless the animals are tested for B-S-E. They also approved a temporary ban on the use of meat and bone meal in animal feed products. The ban will take effect January first and continue for six months.
((MUSIC BRIDGE))Another major science story this year was the return of the Ebola virus in Africa. The virus causes a disease called Ebola hemorrhagic fever.
The Ebola virus affects animals and people. It killed more than two-hundred people in the former Zaire in Nineteen-Ninety-Five. This year, the Ebola virus has killed more than one-hundred-fifty people in Uganda.
The Ebola virus kills so quickly that the body's defense system has no time to act against it. The disease kills fifty to ninety percent of the people it infects.
The disease begins with high body temperature, severe headache and muscle pain. Then it causes severe bleeding and organ failure. Then the victim dies. Doctors say a person with the Ebola virus usually dies within three weeks of becoming infected. The disease spreads by touching the body fluids of an infected person.
No medicine or treatment now exists for the disease. Recently, however, American researchers announced progress in developing a medicine to prevent Ebola hemorrhagic fever in monkeys.
The scientists gave eight monkeys a small but deadly amount of the Ebola virus. They gave an experimental vaccine to only four of them. The monkeys that did not receive the vaccine died within a week. The vaccine prevented the disease in the four monkeys who received it. All four monkeys were healthy six months later.
The researchers said this was the first time a vaccine has protected animals similar to humans from the deadly Ebola virus. They will continue to test the vaccine in animals by giving them increasingly strong amounts of the virus.
((MUSIC BRIDGE))A fourth major science story this year involved the success of another vaccine in tests on monkeys. This vaccine was developed to fight H-I-V, the virus that causes the deadly disease AIDS. The virus attacks the body's defense system against disease. When this system fails, deadly infections and cancers invade the body. Experts say that more than thirty-five-million people around the world are infected with the AIDS virus.
H-I-V spreads to other people when an infected person has sexual relations. It also spreads when a person injects drugs with a needle that was used earlier by an infected person. It also spreads when a person receives blood that contains the virus. Pregnant women infected with H-I-V can pass the virus to their babies before or during birth. They also can pass the virus to their babies through breast-feeding.
Scientists at the Harvard Medical School in Boston, Massachusetts developed the experimental vaccine. They say it prevented monkeys from developing AIDS. The researchers designed the vaccine to make the animals' body defense systems attack and control the virus.
The vaccine did not prevent the monkeys from becoming infected. But it did prevent them from getting sick. The results suggest that a similar vaccine might be developed that could help control the disease in people.
The researchers who developed the vaccine say it works by strengthening a part of the body's defense system called killer T-cells. These T-cells kill the cells the virus has already infected. The Harvard researchers showed that T-cells alone could help control H-I-V.
The researchers tested twenty monkeys. They gave the vaccine to some of them. They gave a false vaccine to others. The researchers infected all the monkeys with an AIDS virus that causes the disease quickly. The monkeys that received the false vaccine all became sick. Half of them died within one-hundred-forty days.
However, none of the monkeys that got the experimental vaccine became sick after eight months. Their bodies produced killer T-cells that attacked the virus. The vaccine appeared to suppress the amount of the virus in the blood.
The researchers do not know how long the vaccine will remain effective in the animals. They say more injections of the vaccine may be needed. But they say the work provides hope that a vaccine for people may one day replace the costly AIDS drugs that are now used to fight the deadly disease.This SCIENCE IN THE NEWS program was written by Nancy Steinbach, Cynthia Kirk and George Grow. It was produced by George Grow. 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.