Minute quantities of the precious metals appear to neutralize a type of protein called MHC class II, which the body employs to rev up the immune system when viruses or bacteria cause an infection. These MHC proteins typically hold up bits of pathogens, like red flags, to summon the help of white blood cells. But in the case of autoimmune disease, the proteins wave around fragments of body tissue, which causes white blood cells to attack the healthy tissue. That leads to inflammation and other autoimmune responses. Platinum and some forms of gold seem to pry the fragments loose.
Scientists hope the discovery of how gold halts the autoimmune response will lead to metal-based medicines that work faster than existing gold and platinum drugs and don't cause side effects. Middle-aged men are advised to have their blood screened for prostate-specific antigen (PSA), which tends to rise in men with prostate cancer. But doctors complain the test generates too many false positives and can't differentiate between aggressive tumors and slower-growing ones.
A more accurate test may be on the horizon. Working with Dr. William J. Catalona, a prostate cancer surgeon at Northwestern Memorial Hospital who first developed the PSA test, diagnostics maker Beckman Coulter (BEC
) has developed a desk-size machine that can detect two distinct forms of the antigen. One indicates that the tumor is unlikely to prove fatal; the other calls for immediate treatment.
This spring, doctors at Northwestern University and Baylor College plan to begin testing the device's accuracy by training it on stored blood samples from patients whose outcome is already known, says Charles Weinzierl, manager of market development at Beckman Coulter's facility in Chaska, Minn. Physics labs around the world are racing to perfect quantum cryptography, hoping to encrypt data with particles of light, or photons. Physics professor Hoi-Kwong Lo and his colleagues at the University of Toronto say they have taken an important step. They created keys that are used to encrypt messages -- composed of pulses of photons -- then intermingled them with "decoy" photons and transmitted them over 10 miles of fiber-optic cable. A separate transmission told the receiving computer how to sort the meaningful photons from the decoys, so that the original messages could be reassembled. Such transmissions aren't exactly tamper-proof. But under the laws of physics, any attempt by hackers or others to inspect the decoy photons also alters them, alerting the researchers that their transmission has been hacked. The work appears in the Feb. 24 Physical Review Letters. -- Before nations can reduce noise pollution that may trouble marine mammals, they need to know what sounds are out there. Researchers at the University of Washington's Applied Physics Laboratory are taking an inventory with devices they designed called Passive Aquatic Listeners (PALs). Moored to seabeds in the Pacific, the South China Sea, and Puget Sound, the PALs identify noises from ships, volcanoes, storms, waves, and the like, and sort the sound sources by frequency.
-- Shoppers for athletic socks often favor 100% cotton, but should they? Engineering students at the University of Missouri-Columbia built a device to test 10 popular brands of socks, measuring slippage and moisture absorption. The verdict: Mixtures of cotton and nylon offer the most desirable characteristics.
-- Since the 1950s, scientists have known that removing certain materials from an electric field lowers the surrounding temperature. In the Mar. 2 Science, researchers at the University of Cambridge, England, say that thin films of perovskite PZT can produce significant cooling effects when activated by an electric field. This could lead to novel cooling components for computer chips.