Robert Clarkson wasn't thinking about measuring oxygen levels in animals and people when he noted a strange signal coming from coal he was studying.
But the discovery may end up improving treatment of cancer, high blood pressure and poor circulation in diabetics, among other things.
Turns out, the reaction he was seeing resulted from prehistoric forests burned in a fire and incorporated into the coal over the eons.
Clarkson, now a UI veterinary medicine professor who isn't a veterinarian but a chemist, was part of a state program to develop ways to remove sulfur from Illinois coal, to make it less polluting and more marketable.
He had a grant to study the coal's structure with a technique called electron paramagnetic resonance, or EPR, which uses a magnetic field to manipulate electrons and generate signals that can provide information about materials at a molecular level.
Clarkson found that the signature his EPR equipment showed was different when the coal was in a vacuum than when it was exposed to the air.
He was puzzled until a coal expert at Southern Illinois University attributed the phenomenon to ?fusinite,? carbon remnants of charcoal from prehistoric forest fires that are highly reactive to oxygen.
Clarkson eventually gave a talk to researchers at the Illinois Electron Paramagnetic Resonance Research Center. Afterward, Harold Swartz, then the UI-based center's head, approached him.
Swartz, a medical doctor as well as a scientist, told him the carbon substance could be a boon in medicine.
They've been working on the idea since, even after Clarkson moved to the UI College of Veterinary Medicine to start its imaging unit and Swartz moved to Dartmouth University Medical School.
?We're just starting a systematic study,? said Swartz of clinical trials at Dartmouth to test the method in human cases of cardiovascular disease and cancer.
The Dartmouth study will look at a solution containing a small quantity of India ink - which is used in tattooing and, similar to the coal, contains carbon particles - for determining oxygen levels in patients who suffer from peripheral vascular disease - poor circulation - and in cancer tumors.
Meanwhile, Clarkson and UI researchers are developing manufactured, wood-based carbon particles that could be even better as oxygen detectors than those in India ink.
Clarkson, who received a $1.25 million grant from the National Institutes of Health and National Cancer Institute last year, also is working on a way to use the particles to determine oxygen levels with magnetic resonance imaging, or MRI, instead of electron paramagnetic resonance.
MRI has the advantage of a large installed base at medical facilities around the country, and it also is deeper penetrating, allowing images to be made throughout the body.
All you have to do is not breathe to know that oxygen is important in the body.
But oxygen levels also are a key element in a number of situations involving medical diagnostics and treatment.
For example, diabetics often suffer from poor circulation and may end up requiring amputation of toes and other extremities if the oxygen deficit becomes severe enough.
In cancer treatment, radiation therapy and chemotherapy require adequate oxygen levels at a tumor site to optimally attack the growth, Clarkson and Swartz said.
The problem is, there's currently no good way to measure oxygen levels in the body's tissue, particularly in a specific location, they said.
A hemoglobin count in blood cells can be used to get some idea, but it isn't a direct measurement, Swartz said. A needle electrode can be inserted to get a more direct measure, but it's unpleasant for the patient and unfeasible for precisely testing the same area over and over, to monitor whether a treatment is working, for instance.
?There really isn't an easy way,? Clarkson said. ?It is not done as a general medical practice. We hope to change that.?
The tiny carbon particles take residence where they're injected and can be used to measure oxygen levels in that area pretty much indefinitely.
?They stay there, so you can keep coming back and follow what's happening,? said UI chemistry Professor Linn Belford, one of Clarkson's collaborators, along with physics Professor Boris Odintsov. ?They are proven to be quite benign, stable, nonpoisonous.?
The particles UI researchers are testing come from their own little forest fire. Paul Ceroke, a chemical engineer, designed a kiln-like furnace where the wood, chipped and ground into sawdust or flakes, is cooked to charcoal at more than 1,100 degrees.
Ceroke has synthesized the carbon particles, called chars, from a variety of woods. He got good results from a local wood, Osage orange, but better results from tropical varieties.
He joined the International Wood Collectors Society to get access to more test subjects and kept testing when the project lost funding for a year. He has screened about 500 varieties in all.
?The charcoal comes out, and then the hard work starts,? Ceroke said.
The material has to be pulverized and sieved for impurities, after which the painstaking process of characterizing its signaling, stability and other qualities takes place.