-- A hospital visit should cure, but it can cause injury. The Oct. 8 issue of the Journal of the American Medical Assn. says in-hospital injuries may account for $9.3 billion in additional charges each year as well as an estimated 32,600 deaths nationwide. One common development -- a severe infection known as sepsis -- typically adds 11 days and more than $57,000 in charges for the unlucky patients. Could a cold make SARS symptoms worse? Thomas G. Voss of Southern Research Institute in Birmingham, Ala., suspects that previous exposure to similar pathogens -- perhaps a cold caused by another corona virus -- could help explain why some people get sicker than others. The theory hinges on the fact that people have two types of antibody responses to disease -- one general and one specific to previous illnesses. With most diseases, levels of generalized antibody spike before levels of specific antibody do. But with SARS, both types increase at almost the same time -- just what you'd expect if SARS is cross-reacting with another virus.
So far, there is no direct evidence of such a link. But researchers have noted that cats vaccinated against a SARS-like virus get sicker than unvaccinated cats when exposed to the bug. What's more, both SARS and the cat virus propagate by latching onto antibodies and then infecting scavenger cells that normally destroy germs. That may explain why an antibody reaction leads to sicker cats -- and it could shed light on the human illness as well. Tiny microchips known as radio-frequency identification (RFID) tags are being hailed as the Next Big Thing. That's because someday they'll probably replace the bar codes used to track goods around the world. Now, thanks to the first RFID tag with a built-in antenna, the next big thing is even teensier -- and one step closer to becoming ubiquitous.
Radio tags on the market use bulky external antennas and cost about 30 cents and up. Hitachi has redesigned the antenna and embedded it in so-called mu chips, which it hopes to sell for as little as 4 cents by 2006. If so, the chip could end up in some surprising places, says Ryo Imura, head of mu chip operations. Hitachi already has fielded inquiries from several central banks that are interested in placing the chips in banknotes to thwart counterfeits. Imura points out that they could also help make driver's licenses, passports, and other paper documents more secure. Bats don't let near-blindness slow them down. To avoid collisions while in flight, they emit high-frequency chirps and process the echoes that return from nearby objects. Now the same sort of echolocation is being built into canes that could help visually impaired humans get around.
Developed by Dean A. Waters, a biologist at England's University of Leeds, the "ultracane" looks like the collapsible white tapping sticks widely used today, but its handle is packed with sensors. A tiny speaker emits 60,000 pulses per second at a frequency humans can't hear. A PC-style processor then calculates how long each echo takes to return and identifies obstacles to be avoided. The stick alerts the user by sending a strong, fast vibration through one of four pads on the handle -- for forward, left, right, or up.
Waters and his team are seeking outside funding to help begin manufacturing. In the meantime, they set up Sound Foresight Ltd. to handle production. The ultracanes will sell for about $660.