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This is SCIENCE IN THE NEWS, in VOA Special English. I'm BobDoughty.
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And I'm Sarah Long. On our program this week: new findings forwomen who have had breast cancer.
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New advice about how to treat earinfections 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 currenttreatment to prevent a return of breast cancer in some women.
Doctors studied patients in thirty-seven countries. All of thewomen were beyond their reproductive years. All of them haddeveloped a kind of breast cancer linked to the female hormoneestrogen. And, all had been through operations to remove thecancerous growths. Then the women began to take the medicinetamoxifen.
Currently, five years on tamoxifen is considered the besttreatment after surgery for breast cancers linked to estrogen. Morethan two out of three breast cancers are this kind. Tamoxifen stopsestrogen from attaching to tumor cells and causing them to spread.After some time, however, tamoxifen can stop working in somepatients.
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Doctor Charles Coombes of Charing Cross Hospital in London ledthe study. It involved more than four-thousand-seven hundred breastcancer patients. All received tamoxifen after their operations.
As part of the study, half the women discontinued that drug aftertwo to three years. They began to take another medicine, calledexemestane [egg-suh-MES-ten]. This drug is known as an estrogenblocker. It stops the production of estrogen in the body.
The doctors found that the women who took exemestane reducedtheir risk for the return of breast cancer by more than thirtypercent. This was compared to the women who continued to taketamoxifen for the remainder of the five years.
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The scientists say ninety-one percent of the women who tookexemestane for three years were cancer-free. This compared toeighty-seven percent of the patients who remained on tamoxifen. Thepatients on tamoxifen also had a higher incidence of cancer in theother breast and other parts of the body.
However, the scientists say the study did not show muchdifference in survival rates between the two groups. Ninety-threewomen who took exemestane died, compared to one-hundred six who tookonly tamoxifen.
The researchers continue to observe the women. They say theythink more time may show higher survival rates for patients onexemestane.
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The findings appeared in the New England Journal of Medicine. Thedrug maker Pfizer helped pay for the research. The company makes theestrogen blocker under the name Aromasin.
The investigators do not suggest that the new drug should replacetamoxifen. But they say tamoxifen can become less effective aftertwo to three years following surgery.
The study does not offer information about possible long-termeffects from the use of exemestane. Doctors say they do not know alot yet about this hormone blocker. But the report did say thatsevere reactions were rare among the patients in the study.
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In the United States, there is some new medical advice about howto treat ear infections in children. The goal is to decrease the useof antibiotic medicines.
Antibiotics kill bacteria that cause infections. But too much usecauses problems. Bacteria grow stronger. And people may develop aresistance to the medicine. Then the drugs might not work if aperson gets a more serious infection.
One of the conditions most commonly treated with antibiotics isear infection in children. So the American Academy of Pediatrics andthe American Academy of Family Physicians have released newguidelines for treatment.
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The guidelines tell parents and doctors that the most importantstep is to ease the pain. Children should first be given painmedicines such as ibuprofen or acetaminophen. Doctors also need tomake sure that a child has acute otitis media, or middle earinfection, before they give antibiotics.
The guidelines say antibiotics may be the right choice forchildren up to the age of two who have ear infections, not justfluid in the ears. The treatment advice says antibiotics may also bethe right choice if a child is very sick or has a high bodytemperature.
But the new guidelines note that eight out of ten children withear infections get better with no antibiotics at all.
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The problem of drug resistance is not limited to antibiotics andear infections.
Bacteria, parasites and viruses are all microbes that causedisease. Antimicrobial medicines like penicillin have savedcountless lives. But they have not always been used correctly. As aresult, antimicrobial resistance also makes it harder now to treatinfections like diarrhea, malaria, tuberculosis and sexual diseases.
People with drug-resistant infections stay sick longer. There isa greater risk they will die. And it is easier for the disease tospread to other people. Drug companies have to make new and morecostly medicines to fight the stronger microbes.
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The World Health Organization says local health care workers areimportant to the effort to reduce drug resistance. But so are thepeople who need treatment. People should not take antibiotics, forexample, in an effort to treat viral infections like the commoncold.
When people do take medicine, it is important to take all of it.People should not discontinue the medicine as soon as they feelbetter.
In poorer countries, people may not have enough money to buy allthe medicine they need. So they do not take enough to kill all theinfection. The microbes get stronger and add to the problem ofresistance.
Food producers also add to the problem. Many give antibiotics toanimals to increase growth or to prevent infections on crowdedfarms.
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In some countries, people can buy antimicrobial medicines withoutan order from a doctor. This was true in Chile, until healthofficials changed the rules. They decided that too many people tookantibiotics.
Because of the changes, people in Chile spent six-million-dollarsless on antibiotics between nineteen-ninety-eight andnineteen-ninety-nine. The W.H.O. says lives and money can be savedif people use antibiotics more wisely.
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In January of two-thousand-three, President Bush offered a planto speed the development of cars powered by hydrogen fuel cells. Thepresident asked Congress to spend more than one-thousand-milliondollars over five years for the program.
A new report says efforts to develop hydrogen as a major fuel inthe next fifty years could change the energy economy of the UnitedStates. The scientists who wrote the report say hydrogen couldreduce 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 hydrogeneconomy could take many years. The say any reductions in oil importsor pollution levels are likely to be small during the nexttwenty-five years.
The scientists prepared the report for the National Academy ofEngineering and the National Research Council. These are part of theNational Academies which advise Congress on science and technologyissues.
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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. Whenused 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 powerfrom the sun, organic matter or wind. Another uses fuels likenatural gas and coal. A third uses nuclear energy.
In their report, the scientists say production costs cannot betoo high if hydrogen use is to become widespread. They say systemswill be needed to supply hydrogen to fueling stations. Also,vehicles will have to store enough hydrogen to go the distancebetween refuelings that drivers have come to expect.
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SCIENCE IN THE NEWS was written by Caty Weaver, Karen Leggett andGeorge 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 newsabout science, in Special English, on the Voice of America.