When Viagra was introduced in 1999, the drug’s manufacturer warned of a number of visual side effects, including possible nerve damage to the eyes. But a California study rules out some of these risks — even when the drug is taken in high doses. According to Dr. Tim McCulley, assistant professor of ophthalmology at the University of California at Irvine, blood flow in the eye does not seem to be reduced by even high doses of the popular erectile dysfunction drug. Since Viagra lowers blood pressure overall, there was persistent suspicion that the drug might cause decreased optical blood flow, which can cause nerve damage.
Scientists racing the clock have snapped a photo of a gamma-ray burst event one minute after the explosion, capturing for the first time a particularly fast-fading type of “dark” burst, which comprises about half of all gamma-ray bursts. A gamma-ray burst announces the birth of a new black hole; it is the most powerful type of explosion known, second only to the Big Bang in total energy release. This latest finding may double the number of gamma-ray bursts available for study and rattle a few theories as well, said scientists from the Massachusetts Institute of Technology, based on an X-ray image taken by the MIT-built High Energy Transient Explorer (HETE) satellite, the first satellite dedicated to spotting gamma-ray bursts.
Global warming is having a significant impact on hundreds of plant and animal species around the world — although the most dramatic effects may not be felt for decades, according to a new study in the journal Nature. “Birds are laying eggs earlier than usual, plants are flowering earlier and mammals are breaking hibernation sooner,” said Terry L. Root, a senior fellow with Stanford’s Institute for International Studies (IIS) and lead author of the Jan. 2 Nature study. “Clearly, if such ecological changes are now being detected when the globe has warmed by an estimated average of only 1 degree F (0.6 C) over the past 100 years, then many more far-reaching effects on species and ecosystems will probably occur by 2100, when temperatures could increase as much as 11 F (6 C),” Root concluded.
A new study suggests that the use of combination hormone therapy is associated with a modest increase in breast density, which is a known risk factor for breast cancer. The findings appear in the Jan. 1 issue of the Journal of the National Cancer Institute. The degree of breast-cancer risk that is associated with breast density is greater than that associated with almost all other known breast-cancer risk factors. A previous analysis of data from the Postmenopausal Estrogen/Progestin Interventions (PEPI) Trial, a randomized trial looking at the effects of postmenopausal hormone therapy (estrogen alone or estrogen plus three different progestin regimens) on breast density, showed that some women who used combination estrogen/progestin therapy experienced an increase in breast density. However, the analysis did not look at the magnitude of that increase.
Drug company AstraZeneca said it has submitted an application to the U.S. Food and Drug Administration for approval of quetiapine (Seroquel) as a treatment for acute mania associated with bipolar disorder, or manic-depressive illness. The application follows the completion of a clinical trial programme in bipolar disorder undertaken by the company which reportedly found quetiapine effective as a treatment of acute mania on two levels: as monotherapy (i.e to be prescribed on its own) and as adjunctive therapy with standard mood stabilising medication. These clinical trials have delivered strong and positive results in both the monotherapy and adjunctive therapy studies, which confirm quetiapine to be an ideal first line therapy for the treatment of acute mania associated with bipolar disorder, the company said.
Race, gender and other social factors may explain why some parents allow their children to play with toy guns, while others shudder at the thought, according to a report in the January issue of Pediatrics. Almost 70 percent of parents surveyed felt it was “never OK” for a parent to let a child play with toy guns. The parents who allowed their children to play with toy guns were more likely to be male, with male children, and Caucasian. Families with younger children and mothers were more likely to limit toy gun play. In general, researchers found the gender and age of the child, gender of the parent, and race of the family factored significantly into parents’ attitudes about allowing their children to play with toy guns.
Drug companies are sponsoring creation of a new medical disorder known as female sexual dysfunction in order to build markets for drugs among women, despite controversy surrounding the medicalisation of sexual problems, finds an article in this week’s British Medical Journal. Over the past six years, researchers with close ties to the pharmaceutical industry have been developing and defining the new disorder at company sponsored meetings, writes journalist Ray Moynihan.
An international collaboration of primatologists has gleaned evidence from decades of observations of orangutans that the apes show behaviors that are culturally based.
The scientists’ findings push back the origins of culturally transmitted behavior to 14 million years ago, when orangutans first evolved from their more primitive primate ancestors. Previous evidence for cultural transmission in chimpanzees suggested an origin of cultural traits 7 million years ago. The researchers also warn that illegal logging and other habitat destruction in the forests of Sumatra and Borneo could not only threaten further research into the earliest origins of culture, but continue the dangerous decline in orangutan populations.
A Dartmouth researcher is building a case for a “dark energy”-dominated universe. Dark energy, the mysterious energy with unusual anti-gravitational properties, has been the subject of great debate among cosmologists. Brian Chaboyer, Assistant Professor of Physics and Astronomy at Dartmouth, with his collaborator Lawrence Krauss, Professor of Physics and Astronomy at Case Western Reserve University, have reported their finding in the January 3, 2003, issue of Science. Combining their calculations of the ages of the oldest stars with measurements of the expansion rate and geometry of the universe lead them to conclude that dark energy dominates the energy density of the universe.
A new study has discovered an abundance of microbial life deep beneath the ocean floor in ancient basalt that forms part of the Earth’s crust, in research that once more expands the realm of seemingly hostile or remote environments in which living organisms can apparently thrive. The research was done off the coast of Oregon near a sea-floor spreading center on the Juan de Fuca Ridge, by scientists from Oregon State University and several other institutions. It will be published Friday in the journal Science.
Eleven percent of the U.S. adult population has varying stages of chronic kidney disease, according to researchers from the Johns Hopkins Bloomberg School of Public Health. The researchers concluded that chronic kidney disease warrants improved detection and classification using standardized criteria to improve patient outcomes. Their research is published in the January 2003 issue of the American Journal of Kidney Diseases.
Past studies have shown that various medications including beta blockers and aspirin can help manage heart disease. Yet a new study from Stanford University Medical Center indicates physicians continue to underprescribe these key treatments. The study appears in the Jan. 1 issue of the Journal of the American College of Cardiology. It focuses on the outpatient use of the drug warfarin for atrial fibrillation (or irregular heartbeat), beta blockers and aspirin for coronary artery disease, and ACE inhibitors for congestive heart failure – all medications that have been shown to benefit patients in past clinical trials and population studies.