THE VIRGINIAN-PILOT
Copyright (c) 1996, Landmark Communications, Inc.
DATE: Wednesday, April 17, 1996 TAG: 9604170365
SECTION: FRONT PAGE: A1 EDITION: FINAL
SOURCE: BY MARIE JOYCE, STAFF WRITER
LENGTH: Medium: 89 lines
A combination of chemicals used to protect Gulf War military personnel from disease-carrying insects and nerve gas causes neurological problems in animals, even though the chemicals are harmless when used separately, researchers at Duke University Medical Center reported Tuesday.
The scientists said their results might explain the broad range of symptoms attributed to Gulf War Syndrome.
Duke researchers, working with scientists at the University of Texas Southwestern Medical Center, looked at an anti-nerve gas pill and two pesticides, DEET and permethrin, which can be absorbed by the skin.
``These chemicals are very safe by themselves,'' even when used at three times the doses given to military personnel, said Duke pharmacologist Mohamed Abou-Donia.
But taken together, they appear to damage nerve fibers called axons, which act like telephone lines to transfer electrical impulses between cells in the brain and the nervous system.
Chickens exposed to a combination of any two of the chemicals suffered shortness of breath, weight loss, diarrhea and tremors.
Although the scientists couldn't measure some Gulf War Syndrome symptoms, like fatigue and joint pain, they observed that the chickens became reluctant to walk or fly and had poor coordination when they did. Duke tested chickens because their reaction to neurotoxins is similar to humans'.
A mix of all three substances paralyzed or killed some chickens.
Abou-Donia said the combination of DEET and permethrin may overwhelm a particular enzyme in the body that combats foreign chemicals, even though the enzyme can handle either one alone. The result is a build-up of toxic chemicals in the blood stream.
The anti-nerve gas agent, called PB, might amplify this problem by blocking the enzyme. PB's job is to shield certain enzymes from nerve gas damage. However, it could also bind with the chemical-cleansing enzyme and prevent it from going after the DEET and permethrin.
The combination may particularly affect some people - about 3 to 4 percent of the population - who have an unnaturally low level of the chemical-cleansing enzyme. This may explain why some veterans report particularly severe symptoms, he said.
The pesticides were used during the war to treat clothing and were sprayed in sleeping areas and bathrooms.
But whether Gulf War Syndrome exists at all is a subject of debate.
A Veterans Affairs spokesman, contacted by the Associated Press, declined to comment on Abou-Donia's findings, saying Veterans officials wanted to thoroughly review his research when it is published in next month's Journal of Toxicology and Environmental Health.
An estimated 30,000 to 40,000 people, including family members of veterans, have reported symptoms.
There's no question that most of them are sick, says Capt. Steven K. Yowell, a doctor at the Naval Medical Center in Portsmouth. Yowell is regional coordinator for a national registry of active-duty Persian Gulf War veterans suffering symptoms.
However, Yowell says, the illnesses may not be related to the Gulf War at all. In some studies, the frequency of many symptoms in Gulf War veterans was no greater that in groups of nonveterans.
Or if the illnesses are related, they may have been caused not by an unusual reaction to specific chemicals or microbes, but by the stress of war, he said. Stress can suppress the immune system, making the body susceptible to a great variety of diseases and conditions.
Abou-Donia at Duke concedes there are limits to the work, since they couldn't test the chemical combinations in humans.
``What we (have) is a scenario to something that might have happened, not necessarily what really did happen,'' he said.
The next step, said Abou-Donia, is looking at blood samples from veterans to see if there is a link between illness and low levels of the chemical-scrubbing enzyme.
The chickens were given combinations at three times the dose given to military personnel. Doctors would like to experiment with lower doses to see if the chickens recover. Such research, he said, may lead to treatments.
They also should investigate the other chemicals that military people were exposed to during the war.
Even if this chemical soup did cause Gulf War Syndrome, the military probably did the right thing in exposing the troops, said Abou-Donia. The chemicals prevented most cases of serious diseases carried by insects.
``The strategy did work,'' he said. ``We could have had 100,000 cases of malaria.''
The Duke study also has implications for civilians, said Abou-Donia. Little is known about potentially dangerous reactions to chemicals used in daily life.
KEYWORDS: GULF WAR SYNDROME GULF WAR VETERAN STUDY by CNB