Ultraviolet-A rays may play a bigger role in promoting skin cancer than previously thought, researchers report.
“There is good evidence that UVB is important, but our studies show that UVA is also very important,” says study author Gary Halliday, a professor of dermatology at the University of Sydney in Australia. The research appeared in last week’s online issue of the Proceedings of the National Academy of Sciences.
Halliday’s team evaluated cells from biopsies taken from 16 patients with squamous cell skin cancer and solar keratosis, precancerous skin growths caused by sun damage. The researchers searched for “signature” DNA mutations. In short, there were UVA mutations deeper and UVB mutations more superficially.
More study is needed. Meanwhile, Halliday says, “Our studies indicate that it is important to protect from both UVB and UVA.” Using a broad-spectrum sunscreen is recommended.
Asthma-inhaler woes
An inactive ingredient found in some asthma inhalers may be counteracting the beneficial effect of steroids, which are often given to people with the breathing disorder.
If validated by future studies, this finding, done with cell cultures in a laboratory, may explain why some people get worse, instead of better, when they use inhalers.
Albuterol, one of a class of drugs called beta-agonists, is often given in combination with steroids to treat asthma and other lung diseases. It works by relaxing and opening the muscle surrounding air passages in the lungs.
Albuterol has two components, an S-isomer and an R-isomer. The R-isomer is the active component, and it was originally thought that the S-isomer, which is inactive, had no effect on people using inhalers.
New research, led by Bill T. Ameredes of the Asthma, Allergy and Airway Research Center at the University of Pittsburgh Medical Center, looked at whether the isomers enhanced or counteracted the anti-inflammatory effects of a steroid given simultaneously. The R-albuterol in combination with the steroid dexamethasone accentuated the anti-inflammatory effects. Unfortunately, the S-albuterol had the opposite effect, nullifying the other effects.
Smokers’ aging brains
Older smokers lose cognitive ability five times faster than non-smokers, research finds.
Dr. Alewijn Ott of the Erasmus Medical Center in Rotterdam, the Netherlands, and colleagues had 9,209 people ages 65 or older take a standard neurological test used to measure cognitive function. Volunteers were also questioned as to their smoking history. All were retested two or three years later to assess rates of intellectual decline over time.
Out of a possible total test score of 30 points, individuals who had never smoked saw their mental abilities decline by only 0.03 points per year–a normal, age-related decline. However, chronic smokers posted much higher intellectual losses: 0.16 points per year, a rate more than five times that of non-smokers.
The average intellectual gap between a 65-year-old and an 85-year-old is about 1.5 points, Ott said.
Findings appeared in the March 23 issue of Neurology.