Super Superbug Threatens Asia

Danger of synthetic poliovirus, the benefits of sleep, and other new research findings offer as much danger as hope

"ULTRA SUPERBACTERIA"

    SEOUL

    South Korean researchers claim they have found superbacteria resistant to the toughest antibiotics spreading in Asia.

    There is no effective weapon against the deadly bacteria because their unique enzyme breaks down antibiotic substances, according to a Yonsei University Hospital research team.

    Team leader Lee Gyung-Won said the bacteria were among the most worrisome problems for doctors as they spread quickly through hospitals. His team tested body waste samples from 7,275 patients from 28 hospitals and found 82 people infected with the bacteria with a new type enzyme called VIM-2.

    The bacteria with VIM-2 enzymes were first reported in France in 2000. It is the first time the superbacteria have been discovered in Asia. "The superbacteria were the result of excessive use of antibiotics," Lee said. The bacteria are resistant to Carpapenem, the most powerful antibiotic, he said.

    Lee said VIM-2 is especially dangerous because it invades other bacteria and renders them immune. "This makes bacteria resistant to antibiotics and patients vulnerable to sepsis or blood poisoning," he said.

HIV GENES IDENTIFIED

    PARIS

    People infected with HIV who have key variations in two genes take longer to develop full-blown AIDS. One of the genes, called KIR, controls a receptor on "natural killer" lymphocytes, a lethal footsoldier in the immune system that is one of the body's first lines of defence against intruders. The other, HLA-B, encodes a protein for human leukocyte antigen (HLA) located on the surface of white blood cells and other tissues.

    Examining blood samples taken from more than 900 people with the human immunodeficiency virus, scientists led by Mary Carrington of the National Cancer Institute in Maryland found that neither gene by itself had any impact on the progression to AIDS. But volunteers who had specific variations in both genes were able to delay the onset of AIDS, said the study published by Nature Genetics.

    Quite how these two genes work together is unclear, they say. "Identification of such interactions may provide new approaches to therapeutic and vaccine development," they suggest.

SYNTHETIC POLIOVIRUS MADE

    WASHINGTON

    Researchers using mail-order materials and a genetic code have synthesized the poliomyelitis virus in the laboratory, raising fears that terrorists could do the same. The synthetic virus was virtually indistinguishable from the original, and first paralyzed, then killed mice injected with it, according to the study at the State University of New York at Stony Brook.

    "The potential for virus synthesis is an additional important factor for consideration in designing the closing strategies of the poliovirus eradication campaign," researcher Eckard Wimmer said in the the journal Science.

    He warned that a synthetic poliovirus would be valuable as a bioweapon if mass vaccination stops and immunity to the disease is lost. Information on virus genomes is easily accessible online, he said. "You search the Internet and lift out a sequence and go to work and make a virus without ever having seen the virus in your laboratory," he said. "This work is very important to put society on alert. This is an inherent danger in biochemistry and scientific research. Society has to deal with it. It won't go away if we close our eyes."

    In an accompanying article, Science said biologists disagreed over how easy it would be to create bioweapons or synthesize bulkier viruses such as smallpox. "It is a little sobering to see that folks in the chemistry lab can basically create a virus from scratch," said James LeDuc of the Centers for Disease Control and Prevention in Atlanta, Georgia.

    A synthetic poliovirus could also lead to benefits for medicine, such as rebuilding other viruses in a weakened form to help devise new vaccine, researchers said.

FOR ADULTS, TOO

    WASHINGTON

    Inoculating adults with children's chicken pox vaccine can help prevent the adult form of the disease, shingles, according to scientists who studied the effects of administering a heat-inactivated form of the vaccine to cancer patients at particular risk of developing shingles.

    The study's results presented at the University of Stanford medical center showed that 13 percent of the 53 patients suffering from lymphoma who were vaccinated developed shingles after a blood transplant to help fight the cancer, versus 30 percent of the 56 study participants who were not vaccinated.

    The vaccine could prove effective in preventing shingles in older patients in good health, the researches wrote in the New England Journal of Medicine.

    Vaccines normally use a weakened strand of a disease, but in this case the study was done with cancer patients and researchers did not want to take any chances with patients with already severely weakened immune systems. The inactivated form used in the inoculations produced the same effect in the patients' immune systems as a normal vaccine would in a healthy person.

LEARNING IN SLEEP

    WASHINGTON

    Getting a good night's sleep can help people's learning curves, and taking an afternoon nap can jump-start a tired brain. Researchers at Harvard Medical School in Cambridge, Massachusetts found those who got a full night's sleep learn new motor skills 20 percent better than people who cut short their sleep, said a study in the July issue of Neuron magazine.

    And a midafternoon nap eased fatigue on the brain and can improve its performance for the rest of the day, said a separate team from the same school in another study published in Nature Neuroscience.

    The first study looked at what implications a good night's sleep had on learning motor skills such as a sport, musical instrument, and artistic movement like a kind of dance. "Our research demonstrates that after a certain time, further practice may not make someone perfect at a motor task, but rather a good night's sleep could be the key to perfection," said Matthew Walker, who directed the team of researchers in the first study.

    Scientists discovered that such skills are recorded as memory during the final hours of the night's sleep, particularly in the last dream phase before awakening.

    'This is the part of a good night's sleep that many people will cut short by getting up early in the morning," Walker said. "You could say that modern life's erosion of sleep time is seriously short changing your brain of valuable learning potential."

    The study also said that this evidence may help to explain why infants sleep so much. "Their intensity of learning new skills and information may drive the brain's hunger for large amounts of sleep."

    The repairing effect of a siesta on the brain was examined in the second study. Its authors subjected participants to a visual series of tests involving cerebral burnout. The results of four series of tests showed a decline in subjects who did not have a midday nap. On the other hand, the performance drop was somewhat corrected in those allowed to nap for 30 minutes after the second session. third group, allowed to sleep for an hour, had improved performances in the third and fourth sessions, and had the best brain functions after the nap since the beginning of the day.

    The researchers also determined that the cerebral exhaustion provoked in the sessions was limited only to the neural networks in the visual cortex. They found that the networks "gradually become saturated with information through repeated testing, preventing further perceptual processing."

    This erosion could be a kind of self-defense mechanism designed for "preserving information that has been processed but has not yet been consolidated into memory by sleep," the study said. The midday nap then resets the networks by downloading the stored visual images during slow wave sleep, which "serves as the critical stage for restoring perceptual performance," researchers said.

NEW DRUG VS. ALZHEIMER'S

    STOCKHOLM

    The new Exiba drug has shown positive results in combating severe cases of dementia among victims of Alzheimer's Disease.

    "There are currently three types of medication to fight Alzheimer's Disease. The first two treat cases of light or moderate dementia but the new drug Exiba is the first effective treatment of severe dementia," said Bengt Winblad, one of the world's top experts on the disease.

    Winblad, who works at Sweden's Karolinska Institutet, said Exiba can affect the movement of glutamate in the brain to relieve dementia. "This drug has created much hope in the fight against Alzheimer's," he said. Alzheimer's disease is a form of dementia that attacks parts of the brain that control thought, memory, and language.

    There is no cure and the causes of the disease, which usually begins after the age of 60, are still unknown.

    With Exiba, Alzheimer's sufferers will require less attention from medical staff, Winblad said. He cited a US study showing that the patient required 12 hours of care instead of 14.