Developments to Watch
Edited by Neil Gross
Keeping the Misery of Chemo to a Minimum
While researchers search for more effective cancer treatments, clinicians struggle to make better use of drugs available now. Doctors at the American Association for Cancer Research meeting in San Francisco on Apr. 6-10 heard about several new diagnostic technologies that help tailor chemotherapy to the individual patient.
Currently, a patient must go through four or five rounds of often-debilitating chemotherapy before doctors can determine whether it's working. An experimental test developed by North American Scientific of Chatsworth, Calif., may be able to predict after a single dose of chemo whether the patient is likely to respond. The test, called Apomate, combines a tracer isotope with a human protein that seeks out and attaches to minute components in a tumor cell's outer coating that appear early in the cell-death process. Detectors then trace the isotope and measure the progress of the cell's deterioration.
Dr. Neil D. Steinmetz, medical director of the company's imaging division, said the test was given to 15 patients in an early clinical trial within three days of their first dose of chemo. Early cell death was detected in seven patients, and all of them responded to treatment. Six of eight patients with a negative test result failed to respond to the chemo, and their disease progressed or they died.
By Catherine Arnst
In a Plastic Bag, Clean Water for the World's Poor
Every day, 10,000 children die from cholera and other waterborne diseases, according to the U.N. Frank Husson, founder of Solar Solutions LLC, thinks he can cut this toll with a low-tech, low-cost plastic pouch that uses the sun's heat to pasteurize water and rid it of harmful bacteria, viruses, and parasites.
In the past, relief organizations have built solar-thermal systems out of metal and glass to purify water. But no one has created a solar-powered pasteurizer cheap enough to deploy widely in very poor areas. With that in mind, Husson's San Diego startup designed AquaPak out of black polyethylene, which is widely used in food packaging, and bubble wrap. Husson says the bags could be made in most Third World countries for as little as $1 each. That's roughly 10% of the cost of the next-best type of solar purifier, says Jay Burch, a solar specialist at the National Renewable Energy Laboratory.
NREL is testing the sack's plastic materials, which are key to its "goof-proof" design, as Husson puts it. When the 15-inch-a-side pack is filled with water and placed on the ground, sunshine warms the water while air-filled bubbles keep the accumulating heat from escaping. In tests, it took 90 minutes to heat the 1.2-gallon AquaPak to 158F. At that temperature, practically all pathogens are cooked after just six minutes.
Husson, who is funding the venture himself, now aims to share the AquaPak design with Third World entrepreneurs, the U.N., and other relief agencies.
By Adam Aston
Cassini Is Cruising to Saturn--Almost on Autopilot
In July, 2004, a spacecraft called Cassini will begin orbiting Saturn, aiming to unlock the mysteries of the distant planet's moons, atmosphere, and famous rings. On Apr. 3, the Jet Propulsion Laboratory in Pasadena, Calif., took a major step toward ensuring that the mission goes off without a hitch. JPL successfully deployed new software that shaves weeks off a complicated task: tweaking the flight path of the 12,346-pound craft, which is nearly three-quarters of the way through its 930-million-mile journey to Saturn.
As Cassini speeds toward the ringed planet, engineers adjust its trajectory a few times a year, but once it arrives, they'll have to maneuver the craft every five days or so. The old system required eight or more engineers performing a series of tasks over a three-week period. The new software automates the process so a handful of engineers can complete the task in roughly half an hour. There are about 150 maneuvers planned for Cassini's orbit, including sending a probe to explore Titan, Saturn's largest moon. "We would not have been able to fly this tour without this software," says Earl Maize, JPL's spacecraft operations team manager. NASA has a lot riding on this four-year, $3.26 billion mission. Launched in 1997, Cassini is the last orbiting spacecraft built before the agency adopted its "smaller, faster, cheaper" policy.
By Arlene Weintraub
Chips with Canals: A Better Way to Test Drugs?
With the tools of modern chemistry, drug companies generate hundreds of thousands of novel compounds a year. But screening these potential drug candidates for biological activity and toxicity has become a real bottleneck. Michael Pishko, an associate professor of chemical engineering at Pennsylvania State University, has devised a system that could help.
Today, companies test promising drug molecules on chips that contain roughly 400 tiny wells, each of which holds a living cell from one or another organ of the body. The cells in the chips are exposed to different drug candidates and then studied to determine the effects. In research backed by NASA, Pishko and graduate student Won-Gun Koh developed cube-like three-dimensional chips riddled with a minuscule network of canals that can transport the chemicals to be tested. In this way, the researchers increased the cell density on the chips by a factor of 1,000.
Pishko's 3-D "microfluidic" canal system is just one of the innovations on these chips. To create an environment that is congenial to living cells, he fabricates the diminutive cell chambers from a Jell-O-like hydrogel. The chambers are then floated into position via the same canals that are later used to transport the chemicals. Pishko has applied for patents, and is talking to potential business partners.
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Copyright 2002 , by The McGraw-Hill Companies Inc. All rights reserved.
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