DECLARED SAFE Vaccines may work medical miracles, but fears of side effects persist. A popular misconception is that they trigger the onset or relapse of multiple sclerosis--a worry that led to the 1998 suspension of a hepatitis-B vaccination program in France. Two new studies conclude there is no link, and urge that public-health campaigns not be derailed because of unfounded concerns. Hepatitis B infects 350 million and kills 1 million every year.
ROBO HEART Only 2,000 human hearts are available each year to the 100,000 Americans who need one. When doctors tried 20 years ago to substitute an artificial heart, the experiment was a heroic failure attended by great public anguish. Now the FDA has approved--but only for testing--a new artificial heart: a grapefruit-size, battery-powered device called AbioCor. The robo heart will give patients limited mobility and is intended to be a permanent organ replacement, not a stopgap remedy.
TIES THAT BIND You don't smoke, you're not overweight and your blood pressure and cholesterol check out O.K. And yet, if a family member has cardiovascular disease, the odds are fifty-fifty that your arteries are silently clogging up too. Researchers found abnormal blood flow in 16 of 32 individuals with a parent or sibling who had the disease. The best way to rewrite this family history is aggressive prevention: exercise, diet and, in some cases, medication.
FOOD FIX Addicted to cheeseburgers? That may not be as farfetched as it sounds. Scientists suspect that people who are obese may eat more in an effort to stimulate the dopamine "pleasure" circuits in their brain, just as addicts do by drinking or taking drugs. New studies show that the obese have fewer dopamine receptors than their normal-weight counterparts. It isn't clear, however, whether the neural difference is a consequence or a cause of obesity.
Sources: Good News--FDA; New England Journal of Medicine (2/1/01); Bad News--Circulation (1/30/01); the Lancet (2/3/01)