2007: The year in biology and medicine

 作者:糜故滩     |      日期:2019-03-02 07:19:02
By Alison Motluk It wasn’t a great year for the fight against infectious disease. By the year’s end, everyone was bickering about how best to share the world’s samples of bird flu, a large AIDS vaccine trial had to be called off after it appeared vaccinated people were even more susceptible to HIV than the unvaccinated, and our old enemy, TB, had made a nasty comeback. In February, the first-ever known case of completely drug-resistant TB was identified in Italy. The worry is that drug-resistant TB strains will spread. Those fears were not calmed by an American diagnosed with extremely drug-resistant TB (dubbed XDR-TB) who, in May, flew from Prague to Montreal, sparking an international health scare. His case turned out to be less serious than originally thought, but in December it was revealed that a highly contagious TB sufferer had travelled by air from Beirut to France and died 10 days later. Authorities were able to contact only seven of the 11 people on his flight who could have been infected. Doctors began dusting off old antibiotics and pre-antibiotic treatments like lung surgery were also being resurrected. One group of doctors even suggested that it was time to think about establishing old-style sanatoriums to help tackle the disease. Elsewhere in medicine, patients began to take matters into their own hands. After a report in New Scientist about a drug, dichloroacetate, or DCA, which appeared to kill off several forms of human cancer in rats, an online chat room popped up to discuss the prospects. Despite the fact that the drug was not FDA-approved, some cancer patients reported that they had acquired some and thought it was working. A sister website began selling the drug under the guise of a pet medicine, until the FDA shut it down. A clinical trial on the drug began this autumn in Canada on patients with brain cancer. Stem cells are coveted because they can turn into any of the body’s tissues. But they have traditionally been hard to come by, often needing to be extracted from human embryos. Scientists have been looking everywhere for them, and this year they showed up in some interesting places. First it was amniotic fluid, then menstrual blood. By November, though, two separate groups of researchers had figured out how to reprogram a person’s own skin cells to become embryonic-like stem cells. Plenty of new uses for these cells emerged this year as well. Researchers grew them into a human heart valve, used them to treat Parkinson’s (in a monkey, mind you), and even coaxed them into becoming primitive sperm cells, opening the door to infertile men and even lesbian women “fathering” their own children. It was a big year for obesity research too. Being heavily overweight was linked to everything from cancer to gum disease. Researchers also suggested a number of new causes of obesity. Could a common cold virus be making us flabby? Was it mostly down to our genes? Or can we blame mum – for having gone through puberty too early? There were new targets for obesity treatments too. For instance, researchers studied how a hormone, PYY, affected the brain circuitry responsible for hunger. Another study looked at ways our bodies decide to burn off energy rather than just storing it as fat. Yet another found that the increasingly popular treatment of stomach stapling really does save lives. Best of all, although being obese puts you at greater risk of heart failure, once you’re suffering from it, the fatter you are, the greater your chances of surviving it. On the other hand, fat people were blamed for being a major contributor to global warming. There was bad news for parents who rely on the TV to keep their kids entertained. It turns out that TV is bad for children of all ages. New evidence suggested that the Baby Einstein videos and their ilk not only don’t make your infant smarter, they may actually impede learning. The researchers found that for every hour an infant watches this stuff, he knows six to eight fewer words. And the damage done by too much TV in childhood may be hard to overcome. A large study of five- to 11-year-olds found that kids who watched more than two hours of television a day were much more likely to have attention problems in adolescence, regardless of whether they continued to be heavy TV watchers. Watching several hours a day as a teen may also make a child more likely to drop out of school or fall behind, a finding that stood up even after learning disabilities and socioeconomic status were controlled for. But enough of the heavy stuff. Guys can now rest assured that it’s their faces, not their muscles,