Pediatric heart-transplant recipients who acquire a viral infection in the heart fare poorly over the long term. (p. 311)

The silencing of a gene called RASSF1A appears to increase the risk of cancer, studies of lung and breast tumors show. (p. 294)

The hippocampus may be the seat of powerful cravings for cocaine in rats and play a key role in drug-addiction relapse. (p. 292)

Fat in the heart may kill cells and eventually lead to heart failure. (p. 296)

The completed genome sequence of Staphylococcus aureus reveals transfers from other organisms of many of the antibiotic-resistance and virulence genes. (p. 296)

Three separate analyses of oral polio vaccine used in the 1950s in Africa deflate the theory that such a vaccine could have ignited the AIDS epidemic by containing virus-infected chimpanzee cells. (p. 296)

Gene therapy to replace a defective RPE65 gene succeeds in bringing sight to three blind dogs, suggesting such therapy might reverse Leber congenital amauosis, a rare condition in which children are blind from birth. (p. 296)

By distorting a protein in the toxin that makes the anthrax bacterium deadly, scientists have discovered a promising way to treat the disease and possibly even to prevent it with a vaccine. (p. 296)

The breast cancer drug tamoxifen can widen a narrowed coronary artery in men with heart problems. (p. 280)

Extended use of the illicit drug called MDMA or ecstasy exacerbated memory problems in users aged 17 to 31, none of whom reported alcohol dependence. (p. 280)

A compound called vasointestinal peptide, which binds to immune system T cells and macrophages, thwarts arthritis in mice. (p. 279)

Patterns of mild electrical disturbance in the brains of epilepsy patients appear to foreshadow a seizure hours before its onset. (p. 276)

A new vaccine links a sugar molecule found on the surface of the bacterium that causes typhoid fever with a genetically engineered version of the exotoxin protein, which arouses the immune system to churn out antibodies against the bacterium. (p. 260)

A vitaminlike substance called coenzyme Q10 helps people with familial cerebellar ataxia, a hereditary disorder that damages the spine and the part of the brain responsible for coordination. (p. 247)

The concentration in blood of one chemically transformed cholesterol-carrying molecule may signal to doctors when a patient's heart disease has dangerously worsened. (p. 245)