CT scans in children can cause small but significant increases in the risk of leukemia and brain cancer, a study finds.
Researchers say the results do not mean that CT scans should be avoided entirely -- they can be vital in certain situations such as diagnosing severe head injuries -- but that the test should be performed only when necessary, and with the lowest possible dose of radiation.
CT, or computed tomography, scans take X-rays from various angles and combine them to create cross-sectional images, and they involve much more radiation than traditional X-ray techniques. At least 4 million U.S. children a year receive scans, and researchers estimate that a third of the scans are unnecessary or could be replaced by tests that do not use radiation, such as ultrasound or magnetic resonance imaging.
The new study, published online in the Lancet, is based on the records of nearly 180,000 British children who had scans from 1985 to 2002. There were 74 cases of leukemia and 135 cases of brain cancer. The authors found that the more scans the children had and the more radiation they received, the higher their risk.
The American College of Radiology urged parents not to refuse needed CT scans, especially for potentially life-threatening conditions like head and spine injuries, pneumonia complications and chest infections.
Men's offices have more bacteria than women's offices. Not only that: Offices in New York City house more bacteria than those in San Francisco.
These are among the findings of a study in PLoS One that looks at bacteria in more than 90 offices in San Francisco, New York and Tucson, Ariz., and on five types of surfaces: chairs, desktops, phones, computer mice and keyboards. The bacteria count in men's offices was 10 to 20 percent greater than in women's.
"It could be men are just bigger -- they have bigger mouths and more surface area -- but it could also be that men are less hygienic," said author Scott Kelley, a microbiologist at San Diego State University.
Fatty acids that occur naturally in the brain may reduce inflammation associated with multiple sclerosis, a Stanford University study suggests.
Researchers showed that injecting high doses of the fatty acids, or lipids, into paralyzed mice with MS symptoms reduced brain inflammation and allowed them to regain movement within 24 to 36 hours, said Lawrence Steinman, an author of the paper published in the journal Science Translational Medicine. Multiple sclerosis is caused by an abnormal immune response that attacks the protective covering that surrounds nerve cells in the brain and spinal cord. The new findings hold promise as a new way to safeguard vulnerable nerves in MS patients, he said. The first human tests of the treatment are still about two years away, he said.