Compared with many other chronic afflictions, such as diabetes or arthritis, little is known about the causes and mechanisms of brain ailments such as depression and bipolar disorder. The latter, also known as manic depressive illness, afflicts more than 2 million American adults and a similar number of children. It causes debilitating mood swings marked by euphoria or dysphoria, excessive energy, impaired judgment, and little sleep.
Even before doctors get a grip on all aspects of the biology, however, they're pushing ahead with some promising therapies for bipolar disorder, many of which involve off-label uses of existing medications. At the National Institutes of Health, for example, Dr. Husseini Manji is looking at the breast-cancer treatment tamoxifen, which relieves the symptoms of mania by inhibiting something called protein kinase C, a signaling pathway within nerve cells. The Food & Drug Administration has warned that tamoxifen might cause uterine cancer. Still, Manji says, it is important to "test the idea that this is the right target."
Major drug companies are taking these innovations seriously. Eli Lilly, for one, is studying the atypical antipsychotic medication olanzapine, sold as Zyprexa, for bipolar depression. The hope is that tamoxifen, Zyprexa, and other multipurpose pills will combat at least some aspects of bipolar disorder better than lithium, which leaves about 40% of patients with tremors or other side effects, continued depression, or no relief at all. Within three to five years, doctors at the NIH hope to have more concrete results on double-duty drugs. A man in a white spacesuit adjusts his headpiece, prompting a laser to scan his retina for molecular sensors just a few billionths of a meter thick. A red light warns that radiation is accumulating in his white blood cells. Maybe it's time for a sojourn on earth.
This isn't Tom Cruise in a summer blockbuster. Within 10 years, NASA astronauts could be using such headgear to monitor their exposure to deadly radiation in space. So says University of Michigan immunologist James R. Baker Jr., whose team has just received a three-year, $2 million grant from NASA to pursue his invention in collaboration with NanoBio Corp. of Ann Arbor, Mich. Baker's blood sensor consists of polymers called dendrimers, tiny balls just 5 nanometers wide that were designed and synthesized by the team. To these balls, scientists attach fluorescent tags that glow when they are in the presence of proteins from dying cells. Inhaled in a cloud by an astronaut, millions of these molecules would be quickly absorbed by the white blood cells--and would glow when radiation began to kill off the cells. When young salmon leave their spawning streams for the open sea, they vanish from the prying eyes of science. "We just don't know where they are," says fisheries professor Conrad W. Recksiek at the University of Rhode Island. That's a problem, because many of the small fry perish on their journey to adulthood--and scientists and fishermen would like to know why. "If we knew more about the habitat, it might help prevent mortality," says Godi Fischer, professor of electrical and computer engineering at the University of Rhode Island. One question, for instance: Is global warming harming salmon stocks?
That's why Fischer and Recksiek have developed a recording chip, measuring just 2.1 mm by 3.3 mm, to help track the fish. Their first working model combines a tiny temperature sensor with a processor, memory, and battery. The plan is to attach the chips to fish, then read the data years later when the salmon are caught. The device will collect a complete record of the water temperatures the fish has swum through. Using temperature readings from the ocean, researchers can roughly chart the fish's wanderings. "The challenge was to make the chip as small as possible and to use very little power," explains Fischer.
Now that the device is working, the scientists have even more ambitious plans, such as adding pressure sensors--or even sonar--to more precisely monitor the piscine journeys. -- An honest-to-goodness fat pill may some day be possible, according to a report in the Aug. 2 issue of Science. A U.S.-Italian research team led by Dr. Eric S. Bachman at Boston's Beth Israel Deaconess Medical Center has shown, using mice, that an internal furnace can be turned up to burn excess calories by stimulating the nervous system with certain hormones, such as adrenaline. An altered strain of mouse lacking adrenaline receptors quickly plumped up on a high-fat diet. Whether humans can similarly "fight fat with fire" remains to be proved, though. And intriguingly, no one knows for sure where this furnace is located. The candidates include the liver, kidneys, and skeletal muscle.
-- Boeing Co. says it has come up with a wallpaper that beats other materials at suppressing noise on planes. About one-quarter-inch thick, it contains compressed air, which counterbalances the oscillations that make up the low-frequency sounds of jet engines. The compressed air is generated by the aircraft engines, eliminating the need for electric power.