In his last days, David was devoted to breath analysis - reading the markers in exhaled breath as a non-invasive diagnostic tool. This grant application (PDF) was to be the next step in breath analysis research.
Several exceprts explaining the promise of breath analysis follow.
DCW on breath analysis
from taped interview Dec 12, 20004
Well, there's another place to access biomarkers in the body, and that's in air that you exhale. Exhaled breath has traces of very interesting signaling compounds in it. Exhaled breath has regulators of the immune system and regulators of inflammation. Inflammation is what happens when your body is attacked by something, and inflammation is the response. Classically, consider a boil on your finger. What happens? The finger gets red as blood cells rush to the area. The finger gets painful as nerves are stimulated. The finger gets hot, because the blood has come and heated it up. And all this makes you want not move that finger very much. You don't want to do a lot if it hurts and it's hot and it's red. You don't want to move it or bang it or anything like that. That's inflammation. Inflammation can occur in any organ, can induce different other reactions depending on what causes it and where it occurs. Among the most important mediators of inflammation are the eicosanoids which are found in exhaled breath as well as other body fluids. They are fatty acid molecules and among the myriad of things they regulate are smooth muscle cells that regulate the distribution of blood by expanding or contracting blood vessels. They are also essential in having a baby again by making a muscle contract. They regulate many other things by locally acting where there is a disturbance. They were discovered in a most interesting way. A Swedish gynecologist noticed that when he had an orgasm his mistress had a contraction of her uterus. He had a thought that the multitude of men in that position never had. Semen must have something in it that makes smooth muscle (the uterus) contract. With his friend Ulf S. von Euler they hired a herd of goats and isolated buckets of semen and separated the semen into as many components as they could and applied each fraction to smooth muscle and checked for contractions. Eventually they found the fraction that induced the contractions was a lipid fatty acid they thought came from the prostate so they called the components prostaglandins. Von Euler, whose father won a Nobel prize in 1929, won his own 1n 1970 for studies of signaling substances and hormones including prostaglandins. The structures of prostaglandins were worked out by Sunne Bergstrom, his student Bengt Samuelsson from Stockholm, and John Vane from England. They found the wonderful actions of aspirin depend on inhibiting the formation of prostaglandins. These three won the 1982 Nobel Prize in Medicine.
These regulatory prostaglandin molecules are clearly in the blood. If they're in the blood, they're in the lung, and if they're in the lung, they will be in the exhaled breath. Prostaglandins regulate. They say where blood goes by regulating the diameter of the tiniest arteries and shunting blood to the areas served by the dilated arterioles. This concentration of the blood also concentrates the and other prostaglandins activate the white cells to secrete their defense molecules. If you can find these regulators in the breath, you could have a non-invasive way to assess them as ideal biomarkers for monitoring the blood as it passes through the lung. It's much easier to get breath from twenty people than it is urine or blood. Breath condensate is a lot easier to process than blood or urine because there's less junk in it. So non-invasive recovery of breath condensate could be a really nice assay and that is a major goal in our laboratory. If we don't do it, somebody else will. It's going to happen. You're going to be able to breathe onto some biosensors designed to detect the proper biomarkers that are in the breath condensate and get an early indication of impending inflammation and possibly powerful evidence as to what might be causing thee inflammation. Exhaled breath analysis will be particularly useful in studying the lung. Inflammation in the lung is difficult to access when it is just starting. How do you know when your lung is starting to become inflamed? I don't think it's a very good idea for you to stick a needle down my nose through my throat into my trachea and biopsy an alveolus. Thanks but I'm not about to let you do that. But you ask if the breath has the compounds in it that signal inflammation and have only to blow into a nice white sterile breath catcher device and that is proving very easy to do.
Interview by Kenneth W. Ford
Memo from DCW, October 2003
Breath analysis made the D section or the Wall Street Journal (with a
picture on page 1). Sandy and I actually visited Michael Phillips
laboratory at St. Vincent’s Hospital on Staten Island. He captures
volatiles for about 15-30 min on a charcoal/ tenex trap that the subjects
breathe into. The tubes are then sent to the laboratory and are heated to
purge into a gas chromatograph/mass spectrometer to separate and identify
the volatile breath components. He measures largely hydrocarbons. The trap
and purge destroys the most of the aldehydes and other labile compounds in
the breath. Phillips defines oxidative stress with pentane (he can’t see
ethane) and some other hydrocarbons he thinks comes from polyenoic fatty
acid breakdown induced by reactive oxygen. Our system that we are trying
to get supported assesses focuses on an earlier step in the regulatory
process. The regulatory lipids (called eicosanoids) that direct blood supply
through action on vessel muscles and activate cells in inflammation, immune
modulation, responses to toxicity, and direct measures of oxidative stress.
Many drugs focus on these regulators--Aspirin inhibits the formation of
eicosanoid prostaglandins that is why it modifies pain. These compounds are
at the heart of regulatory controls so their analysis could give us an
excellent opportunity to develop presymptomatic harbingers of what could
come from specific exposures. These components are found in aerosols
collected in breath condensate that now takes 15-30 minutes. Someday you
might be able to breath over an array of the receptors of these regulators
and the patterns of binding could give a diagnosis or monitoring of therapy.
Another use is older news for 13C detection of infection with H. plyori.
and effective therapy for cystic fibrosis...
David C. White, M.D., Ph.D.
UTK/ORNL Distinguished Scientist