Tuberculosis Drug May Cure Parkinson's-like Illness
Parkinson's-like Illness Treatment
Researchers have discovered that a drug used to treat tuberculosis apparently cures patients of a Parkinson's-like illness suffered by thousands of mineworkers, welders and others exposed to high levels of the metal manganese. Manganese is used to produce steel alloys and as a coating on welding rods, among other industrial applications. It replaced lead decades ago as a component in unleaded gasoline, increasing the risks of manganese intoxication for the general public, said one of the researchers, Wei Zheng, a professor and University Faculty Scholar in Purdue's School of Health Sciences.
When manganese builds up in toxic levels in the body, people suffer from "occupational manganese parkinsonism," which causes symptoms similar to Parkinson's disease. Victims experience hand tremors, poor coordination, unsteady gait and a masklike inability to show facial expressions, Zheng said.
Manganese contained in the coating of welding rods is released in fumes. Welders involved in manufacturing vehicles, tanks and ships are especially prone to manganese intoxication because they work in close quarters, increasing their exposure to the metal, Zheng said.
"There are about 430,000 welders in the United States alone, and even more in China, so manganese intoxication likely affects many people, including workers involved in manganese mining and steel production," he said. "In Beijing, we found a high percentage of welders have these symptoms."
While the condition's symptoms are similar to those of Parkinson's disease, the standard treatments for Parkinson's disease, including the drug levodopa, are not effective for manganese intoxication. A chemical compound called EDTA has been used to help patients eliminate manganese in the urine. The drug's effectiveness, however, is limited because it is water-soluble, preventing it from readily passing through membranes in the "blood-brain barrier," layers of cells surrounding blood vessels that block substances from traveling from the blood into brain tissue.
Ten researchers from institutions around the world