News in brief - Nov. 20, 2006

HPV test better screening tool for cervical cancer in older women - Laser treatments ineffective in preventing vision loss from AMD - Salt reduction lowers blood pressure in children - Trial MRSA vaccine proves effective in mice

HPV test better screening tool for cervical cancer in older women

A large Danish study found the test for human papillomavirus to be a much more effective way to screen for cervical cancer among women older than 40 than is the traditional Pap smear.

Since the presence of HPV is both more frequent and more transient in younger women, more in this age group would test positive even when there is no actual risk of cervical cancer, said the researchers. But in older women, HPV infection is more rare and more persistent, placing those older than 40 at substantial risk for the disease before changes in cervical cells, detected by Pap smears, are obvious. Researchers studied 8,656 women ages 22 to 32 and the 1,578 women ages 40 to 50.

Laser treatments ineffective in preventing vision loss from AMD

Low-intensity laser treatment is not beneficial at slowing or preventing the loss of vision from age-related macular degeneration, according to the findings of a study of more than 1,000 people.

The results of the Complications of Age-Related Macular Degeneration Prevention Trial were published in the November Ophthalmology.

The fact that laser treatments were found to reduce the number of drusen under the retina, the first sign of AMD, led the National Eye Institute to conduct the trial to assess the safety and effectiveness of such treatment in preventing vision loss among people with large drusen in both eyes. It found there was no difference in vision or in progression to advanced AMD.

Currently, the only established way to decrease the risk of vision loss in people with large drusen remains taking daily supplements of vitamins C and E, beta-carotene, zinc and copper, said the researchers.

Salt reduction lowers blood pressure in children

Lowering the salt intake of youngsters reduces blood pressure and may translate to health benefits in adulthood, according to a meta-analysis published in November's Hypertension.

Researchers gathered data from trials that followed patients younger than 16 who decreased their salt intake for at least two weeks. In infants, systolic blood pressure went down an average of 2.47 points. Among older children the decline was less dramatic, but still statistically significant, at just over one point in the systolic and diastolic numbers.

The authors suggest that reducing childhood salt consumption may dramatically improve overall health because previous studies have indicated that blood pressure levels at younger ages correlate with the numbers at older ages. Additional research has also indicated that a populationwide decrease, even if only by a couple points, can make a dent in cardiovascular disease.

"We already know that a modest reduction of salt intake in adults causes very worthwhile falls in blood pressure, but this new research now strongly supports the same policy of salt reduction in children," said Feng J. He, PhD, lead author and research fellow at the Blood Pressure Unit at St. George's University of London.

Salt intake has long concerned physicians, and the American Medical Association adopted policy in June urging that the amount of this substance in processed food should be reduced by half.

Trial MRSA vaccine proves effective in mice

A shot comprised of four surface proteins from Staphylococcus aureus can protect mice from several drug-resistant strains of this bug, according to a study published in the Nov. 7 Proceedings of the National Academy of Sciences.

Researchers tested 19 proteins to select the ones that elicited the strongest immune response. The four that did were tested in mice that were then infected with this bacteria.

"The combination vaccine provided complete protection," said Olaf Schneewind, MD, PhD, lead author and professor and chair of microbiology at the University of Chicago.

This bacteria is becoming increasingly resistant to antibiotics and experts say a vaccine is needed urgently.

"This finding represents a promising step toward identifying potential components to combine into a vaccine designed for people at high risk of invasive S. aureus infection," said Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases. NIAID funded the study.