Body & Brain

Small baby, high blood pressure Especially tiny babies may grow into salt-sensitive adults, according to a new Finnish study. The study correlated blood pressure in 1,512 people around 62 years old with their birth weight. No link between salt intake and systolic blood pressure emerged in people who had weighed at least 6.72 pounds at birth. But among those born smaller, each extra gram of salt consumed daily (up to 10 grams) raised systolic blood pressure, the first number in a reading, by 2.48 millimeters of mercury, the scientists report in the February American Journal of Clinical Nutrition . These increases could hike stroke and heart risks substantially, the team observes. — Janet Raloff Rethinking breast cancer surgery Extensive removal of nearby lymph nodes during surgery for early-stage breast cancer doesn’t guarantee longer survival, researchers report in the Feb. 9 Journal of the American Medical Association . In cases where breast cancer has spread to a sentinel lymph node — the first stop outside a breast where cancer is likely to show up — surgeons often remove that node and many others beyond it. But the risk of complications from the more aggressive surgery might not be worth enduring, say researchers at Saint John’s Health Center in Santa Monica, Calif. Two groups of patients studied, one averaging removal of only two sentinel nodes and the other averaging removal of 17, had similar five-year survival rates, the researchers show. — Nathan Seppa New itch A compound used to treat genital warts, skin cancers and other skin diseases packs a powerful itch, researchers report in a study published online February 7 in the Proceedings of the National Academy of Sciences . In addition to its day job of treating skin disorders, this compound, called imiquimod, activates certain kinds of itch-sensing cells, causing a ferocious desire to scratch. Imiquimod caused mice to start scratching within 20 seconds — a much shorter time than for other itchy compounds, the team of researchers from California and Seoul, South Korea, found. The results may help scientists understand the oft-neglected problem of itch. — Laura Sanders Head injury hurts survival Regardless of severity, a head injury seems to place a person at increased risk of death following the event, researchers at the University of Glasgow in Scotland report. The scientists identified 757 people hospitalized for a head injury in the mid-1990s, and noted that two-fifths had died in the subsequent 13 years. Two other groups of 757 people each, one group from the surrounding community who were not injured and the other comprised of people admitted with injuries that were not to the head, had mortality rates of 19 and 28 percent during that time. The research, reported online January 31 in the Journal of Neurology, Neurosurgery and Psychiatry , raises the question of what might lead to this vulnerability. — Nathan Seppa Bacteria contribute to preterm birth Some types of bacteria growing in the placenta during pregnancy may trigger an early birth, researchers from Harvard Medical School say. The team examined placentas from 527 premature babies and found that about half harbored bacteria. The babies also had different levels of inflammation that correlated with the type of bacteria found in the placenta. Bacteria that cause vaginal infections were associated with high levels of inflammation, while Lactobacillus bacteria (relatives of bacteria found in yogurt) were associated with low inflammation, the researchers reported January 18 in the online journal mBio . — Tina Hesman Saey