2004-4-19
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This is SCIENCE IN THE NEWS, in VOA Special English. I'm Bob Doughty.
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And I'm Sarah Long. On our program this week: new findings for women who have had breast cancer.
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New advice about how to treat ear infections in children.
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Plus, the future of a so-called hydrogen economy.
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Researchers say a new drug may work better than the current treatment to prevent a return of breast cancer in some women.
Doctors studied patients in thirty-seven countries. All of the women were beyond their reproductive years. All of them had developed a kind of breast cancer linked to the female hormone estrogen. And, all had been through operations to remove the cancerous growths. Then the women began to take the medicine tamoxifen.
Currently, five years on tamoxifen is considered the best treatment after surgery for breast cancers linked to estrogen. More than two out of three breast cancers are this kind. Tamoxifen stops estrogen from attaching to tumor cells and causing them to spread. After some time, however, tamoxifen can stop working in some patients.
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Doctor Charles Coombes of Charing Cross Hospital in London led the study. It involved more than four-thousand-seven hundred breast cancer patients. All received tamoxifen after their operations.
As part of the study, half the women discontinued that drug after two to three years. They began to take another medicine, called exemestane [egg-suh-MES-ten]. This drug is known as an estrogen blocker. It stops the production of estrogen in the body.
The doctors found that the women who took exemestane reduced their risk for the return of breast cancer by more than thirty percent. This was compared to the women who continued to take tamoxifen for the remainder of the five years.
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The scientists say ninety-one percent of the women who took exemestane for three years were cancer-free. This compared to eighty-seven percent of the patients who remained on tamoxifen. The patients on tamoxifen also had a higher incidence of cancer in the other breast and other parts of the body.
However, the scientists say the study did not show much difference in survival rates between the two groups. Ninety-three women who took exemestane died, compared to one-hundred six who took only tamoxifen.
The researchers continue to observe the women. They say they think more time may show higher survival rates for patients on exemestane.
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The findings appeared in the New England Journal of Medicine. The drug maker Pfizer helped pay for the research. The company makes the estrogen blocker under the name Aromasin.
The investigators do not suggest that the new drug should replace tamoxifen. But they say tamoxifen can become less effective after two to three years following surgery.
The study does not offer information about possible long-term effects from the use of exemestane. Doctors say they do not know a lot yet about this hormone blocker. But the report did say that severe reactions were rare among the patients in the study.
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In the United States, there is some new medical advice about how to treat ear infections in children. The goal is to decrease the use of antibiotic medicines.
Antibiotics kill bacteria that cause infections. But too much use causes problems. Bacteria grow stronger. And people may develop a resistance to the medicine. Then the drugs might not work if a person gets a more serious infection.
One of the conditions most commonly treated with antibiotics is ear infection in children. So the American Academy of Pediatrics and the American Academy of Family Physicians have released new guidelines for treatment.
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The guidelines tell parents and doctors that the most important step is to ease the pain. Children should first be given pain medicines such as ibuprofen or acetaminophen. Doctors also need to make sure that a child has acute otitis media, or middle ear infection, before they give antibiotics.
The guidelines say antibiotics may be the right choice for children up to the age of two who have ear infections, not just fluid in the ears. The treatment advice says antibiotics may also be the right choice if a child is very sick or has a high body temperature.
But the new guidelines note that eight out of ten children with ear infections get better with no antibiotics at all.
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The problem of drug resistance is not limited to antibiotics and ear infections.
Bacteria, parasites and viruses are all microbes that cause disease. Antimicrobial medicines like penicillin have saved countless lives. But they have not always been used correctly. As a result, antimicrobial resistance also makes it harder now to treat infections like diarrhea, malaria, tuberculosis and sexual diseases.
People with drug-resistant infections stay sick longer. There is a greater risk they will die. And it is easier for the disease to spread to other people. Drug companies have to make new and more costly medicines to fight the stronger microbes.
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The World Health Organization says local health care workers are important to the effort to reduce drug resistance. But so are the people who need treatment. People should not take antibiotics, for example, in an effort to treat viral infections like the common cold.
When people do take medicine, it is important to take all of it. People should not discontinue the medicine as soon as they feel better.
In poorer countries, people may not have enough money to buy all the medicine they need. So they do not take enough to kill all the infection. The microbes get stronger and add to the problem of resistance.
Food producers also add to the problem. Many give antibiotics to animals to increase growth or to prevent infections on crowded farms.
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In some countries, people can buy antimicrobial medicines without an order from a doctor. This was true in Chile, until health officials changed the rules. They decided that too many people took antibiotics.
Because of the changes, people in Chile spent six-million-dollars less on antibiotics between nineteen-ninety-eight and nineteen-ninety-nine. The W.H.O. says lives and money can be saved if people use antibiotics more wisely.
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In January of two-thousand-three, President Bush offered a plan to speed the development of cars powered by hydrogen fuel cells. The president asked Congress to spend more than one-thousand-million dollars over five years for the program.
A new report says efforts to develop hydrogen as a major fuel in the next fifty years could change the energy economy of the United States. The scientists who wrote the report say hydrogen could reduce air pollution and expand the energy supply.
However, the scientists also express concern about technical, economic and other barriers. They say the development of a hydrogen economy could take many years. The say any reductions in oil imports or pollution levels are likely to be small during the next twenty-five years.
The scientists prepared the report for the National Academy of Engineering and the National Research Council. These are part of the National Academies which advise Congress on science and technology issues.
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Hydrogen is a gas. It is the most common element in the universe. By weight, it produces more energy than any other fuel known. When used to power an engine, the only waste produced is water. However, hydrogen explodes easily. It is difficult to store and keep safe.
One way to produce hydrogen uses renewable energy, such as power from the sun, organic matter or wind. Another uses fuels like natural gas and coal. A third uses nuclear energy.
In their report, the scientists say production costs cannot be too high if hydrogen use is to become widespread. They say systems will be needed to supply hydrogen to fueling stations. Also, vehicles will have to store enough hydrogen to go the distance between refuelings that drivers have come to expect.
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SCIENCE IN THE NEWS was written by Caty Weaver, Karen Leggett and George Grow. Cynthia Kirk was our producer. This is Sarah Long.
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And this is Bob Doughty. Join us again next week for more news about science, in Special English, on the Voice of America.