Health & Science
Can electric pulses reverse Alzheimer’s?; An ancient lake on Mars; A disgusting miracle treatment; Shape-shifting DNA
Can electric pulses reverse Alzheimer’s?Frustrated by the mediocre results of drugs designed to combat Alzheimer’s disease, researchers are trying a new treatment: brain pacemakers. The devices have now been implanted in several dozen patients’ brains, where they provide constant electrical stimulation to damaged regions involved in memory. Kathleen Sanford, who has early-onset Alzheimer’s, became one of the first patients to test the new treatment several months ago. Doctors at Ohio State University drilled holes in her skull and implanted tiny wires, which transmit pulses from a battery-powered generator lodged near her collarbone. Researchers will now observe Sanford for two years to see the results. “We’re getting tired of not having other things work,” neurologist Douglas Scharre tells the Associated Press. The technique, called deep brain stimulation (DBS), has been used before to help block the tremors of Parkinson’s disease and, experimentally, to curb the appetite of obese people. Researchers got the idea to test DBS on people with dementia when its electrical jolts awakened lost memories in a man receiving the treatment for obesity. Brain stimulation won’t reverse Alzheimer’s root cause—which appears to be the buildup of plaques in brain circuits—but the electric current may restore communication between neurons, Scharre says, and thus “make the brain work better.”
An ancient lake on Mars The Mars Reconnaissance Orbiter has spotted remnants of an ancient lake that could yield some of the best evidence yet of life on Mars. Researchers examined images of the 1.4-mile-deep, 57-mile-wide McLaughlin Crater—one of the planet’s deepest—and found evidence of clay and carbonates, minerals that form in the presence of water. They saw no surface channels leading into the crater, suggesting that water didn’t flow into it from rivers but rather welled up from underground some 4 billion years ago. That makes the crater an ideal place to search for microbes that may have originated—and could still exist—deep below the Martian surface. On Earth, primitive microbes living miles underground make up perhaps half of our planet’s biomass. “We don’t know how life on Earth formed,” planetary geologist Joseph Michalski, of London’s Natural History Museum, tells BBCNews.com, “but it is conceivable that it originated underground, protected from harsh surface conditions that existed on early Earth.” He thinks microbes might still live on Mars. “It doesn’t take too much imagination to picture a scenario in which the subsurface is habitable today.”
A disgusting miracle treatment In the U.S. alone, some 3 million people a year endure a severe intestinal infection that resists antibiotic treatment and causes fever, vomiting, diarrhea, and sometimes death. Now researchers say the infection, caused by Clostridium difficile bacteria, can be completely vanquished with an unorthodox and somewhat off-putting therapy: fecal transplantation. Dutch researchers cured 15 of 16 infected patients by running a blended infusion of donated stool and saline through a tube passed up their noses, down their throats, and into their small intestines. Antibiotics worked for only 27 percent of patients in two control groups. The study provides “the first hard evidence” that fecal transplants are the best way to wipe out C. difficile infections, Josbert Keller of the University of Amsterdam tells Reuters.com. They likely do so by replenishing the gut’s supply of healthy bacteria, an approach that could one day be used to combat other ailments. The question now is whether patients and physicians will overcome their squeamishness toward donated feces. “Those of us who do fecal transplant know how effective it is,” says Colleen R. Kelly, a gastroenterologist with the Women’s Medicine Collaborative in Providence, R.I. “The tricky part has been convincing everybody else.”
Shape-shifting DNA Sixty years after James Watson and Francis Crick discovered DNA’s double-helix structure, scientists have spotted DNA wrapped in a quadruple helix—and that discovery might one day help thwart cancer. The quadruple helix—called the G-quadruplex—is shaped like a square and contains mostly guanine, one of the four chemical groups, or bases, that make up regular DNA. Scientists previously engineered the quadruplex structures in the lab, but they weren’t sure if they existed in nature until a recent search at Cambridge University revealed an abundance of them in human cancer cells. The quadruplexes were present in particularly high numbers just before the cells began to divide and replicate, suggesting they may be involved in helping cancer to spread. Researchers were able to target the quadruplexes with synthetic molecules and stop them from multiplying. That success “is hugely exciting,” Cambridge chemist Shankar Balasubramanian tells Wired.co.uk. He thinks it could lead to “a new paradigm’’ for attacking cancer.