Remedies for overexposure lacking

Scientists hunt for treatments

March 29, 2011|By Lauran Neergaard, Associated Press

WASHINGTON — Japan’s nuclear emergency highlights a big medical gap: Few treatments exist to help people exposed to large amounts of radiation.

But some possibilities are in the pipeline — development of drugs to treat radiation poisoning, and the first rapid tests to tell who in a panicked crowd would really need them.

The United States calls these potential products “countermeasures,’’ and they are part of the nation’s preparations against a terrorist attack, such as a dirty bomb. But if they work, they could be useful in any kind of radiation emergency.

“Thinking of terrorist events is what drives us. Mother Nature can be much of a terror, too,’’ says Dr. Robin Robinson, who heads the federal Biomedical Advanced Research and Development Authority, or BARDA, that funds late-stage research of products the government deems most likely to pan out.

BARDA has invested $164 million for research into antiradiation treatment candidates since 2008, and $44 million for radiation testing in hopes of adding such products to the nation’s emergency medical stockpile soon. That is in addition to research dollars from the National Institutes of Health and the Defense Department.

Japan’s crisis — in which two nuclear plant workers were hospitalized for radiation burns last week — is sure to renew attention to a field that has long been overshadowed by the hunt for protections against bioterrorism, not radiological emergencies. Among the radiation projects considered farthest along in development:

■ Rapid tests that could spot dangerous radiation doses with mere finger-pricks of blood. Already, a prototype machine sits at New York’s Columbia University that could check thousands of people.

■ Some drugs now used to help cancer patients boost their infection-fighting blood cells, sold under such names as Neupogen. They may do the same thing for radiation victims.

■ An injection that saved monkeys from highly lethal beams. It seems to protect the body’s two most radiation-sensitive spots, the bone marrow and lining of the gut.

Today, there are only a few proven therapies for radiation injuries. Good supportive care — lots of fluids, infusions of blood-clotting platelets, and infection-fighting antibiotics — is key for acute radiation syndrome, an overall poisoning that can begin causing symptoms days to weeks after a super-high exposure.

To guard against longer-term harm, doses of potassium iodide can protect against future thyroid cancer by shielding the thyroid from one type of fallout, radioactive iodine. A few other treatments can help the body eliminate radioactive cesium and a few other isotopes.

Part of the challenge is radiation’s variety of injuries — burns, bone marrow and gastrointestinal damage, lung scarring, the later-in-life cancer risk. Yet outside of an immediate blast zone where open wounds and burns make injury clear, there’s no fast way to tell who got a huge dose.

The Geiger counter-style monitors used on power-plant workers in Japan detect contamination on clothing or skin that might not enter the body, not what the body has absorbed, says medical physicist David Brenner, director of Columbia’s Center for Radiological Research.

Moreover, previous emergencies have shown that sheer stress can cause nausea and diarrhea that mimic some early symptoms of radiation sickness in people who were not exposed, he adds.

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