SCIENCE IN BRIEF: Switch found for tamoxifen

Scientists have pinpointed the molecular on-off switch that the powerful drug tamoxifen uses to attack breast cancer and that prevents it from working in some women. The drug works by turning off a gene that causes tumors to grow, but sometimes it fails in a molecular tug-of-war with another protein, said Jason Carroll, a cancer researcher at the Cambridge Research Institute in Britain and a co-author of research published in Thursday’s editions of the journal Nature. The discovery of the on-off switch should help doctors test for resistance to the drug, the chief treatment for breast cancers that are estrogen-driven, he said. Tamoxifen doesn’t work in about one-quarter to one-third of women who are treated with it, and a test for resistance is probably about five years away, Carroll said.

Experts really are talking about you

If you think they’re out to get you, you’re not alone. Paranoia, once assumed to afflict only schizophrenics, may be a lot more common than previously thought. Experts say there is a wide spectrum of paranoia, from the dangerous delusions that drive schizophrenics to violence, to the irrational fears many people have daily. A British survey of more than 8,500 adults has found that 21 percent of people thought there had been times when others were acting against them. Another survey of about 1,000 adults in New York has found that nearly 11 percent thought other people were following or spying on them. “We are now starting to discover that madness is human and that we need to look at normal people to understand it,” said Dr. Jim van Os, a professor of psychiatry at Maastricht University in the Netherlands who was not connected to the studies. The post-Sept. 11 atmosphere and the war on terror have increased levels of paranoia in the West, some experts said. “We are bombarded with information about our alert status and we’re told to report suspicious-looking characters,” said David Penn, a professor of psychology at the University of North Carolina. “That primes people to be more paranoid.”

Brain pacemaker helps OCD in study

The same kind of deep brain stimulation used to treat some patients for Parkinson’s disease also helped a few people suffering from obsessive-compulsive disorder, French scientists reported in Thursday’s New England Journal of Medicine. Their study involved only 16 patients, but in four of them, symptoms nearly disappeared. However, many patients had serious side effects, including one case of bleeding in the brain. The treatment involved an experimental brain pacemaker, which reduced repetitive thoughts and behaviors in some of the patients —- just as it blocked tremors for some of the Parkinson’s sufferers. Other small studies have targeted a different part of the brain for obsessive-compulsive disorder and depression. In the French study, obsessive-compulsive symptoms were reduced more than 25 percent, the researchers said. The results are “very encouraging,” said the study’s lead author, Dr. Luc Mallet of Pitie-Salpetriere Hospital in Paris. But he said the procedure should be used only in medical studies at the moment because of the possible side effects.

Same-gender hearts better

Turns out men and women really are different at heart: New research finds that heart transplant patients have better odds of survival and a lower risk of rejection if they get organs from donors of the same sex. Size may be part of the explanation. Men’s hearts are bigger than women’s and have greater pumping capacity, and men who get men’s hearts fare better. But doctors think differences in hormones or immune systems between the sexes may also play a role. The study, paid for by the federal government, was presented Wednesday by Dr. Eric Weiss, a cardiac surgery researcher at Johns Hopkins University in Baltimore, at an American Heart Association conference in New Orleans.