By Jim Barlow Research that began in an effort to study acid rain has identified a component in coal that may have an important medical application. The component, an organic carbon-sulphur compound known as fusinite, can be used to measure oxygen levels in vital organs or tissue. In a collaborative effort supported by the National Institutes of Health, researchers from the UI and Dartmouth University are using fusinite and newly created substitutes to enhance a spectroscopic imaging technology known as electron spin resonance (ESR). Scientists can place fusinite in living cells and then watch a virus as it alters oxygen and nitric oxide metabolism. They can see the effects of the virus on a single cell. Cardiologists are studying whether they can use the material to check for the effect of oxygen deprivation on the heart and surrounding areas as a way to help them decide whether coronary bypass surgery will work. Extensive animal testing has found the tiny fusinite molecules to be safe and long-lasting in the tissue into which it has been placed intravenously or with a fine needle. "These microparticles are hydrophobic - they repel water," said Robert Clarkson, a UI professor of medicine, of bioengineering and of veterinary clinical medicine. "And they don't consume oxygen, they just report on it. They just tell you what they see; they don't buy or sell anything in the environment they enter, so the medical applications could be quite significant." The potential human-imaging advancement had it roots in the state's efforts in the 1980s to study the molecular properties of Illinois coal, which has a high sulphur content. Clarkson chose to study coal using ESR - also known as electron paramagnetic resonance and electron magnetic resonance. His lab since has developed the most powerful, high-frequency ESR equipment in the world. Once Clarkson's team had an understanding of how fusinite worked to report on oxygen, then-UI medical researcher Hal Swartz, now of Dartmouth, recognized the medical implications. In September, during the International Workshop on In Vivo ESR and ESR Imaging in Italy, Clarkson described synthetic fusinite and how it can be used as a contrast agent in human imaging. His team's development of synthetic fusinite, also funded by the NIH, was described in an article published in 1994. Since then, Clarkson has had numerous requests for samples. Fusinite is nothing more than charcoaled bits of trees from prehistoric forest fires that fell into "the soup that became coal," he said. "I didn't have any clue when I started studying coal 14 years ago that any of this medical application was going to happen," Clarkson said. "I was interested in what was in coal. Now we've gone past what we discovered in nature. We've learned to make these materials and tailor their properties to ask specific questions that biologists and medical researchers are interested in finding answers to. We are poised to learn a lot about cellular biology and about disease in humans by using synthetic 'coal' to get a readout on oxygen status in living people."