The speaker provided data from several studies which documented increases in isoprostane formation in models of atherosclerosis, neurodegenerative disorders, and kidney disease. The speaker also indicated that is may be advantageous to measure specific isoprostane metabolites to eliminate artifactual formation and because urine can be used. The speaker also cautioned and provided data to suggest that isoprostane analysis may not provide accurate indication of the severity of oxidant insult at high oxygen pressures. Dr. Terence Risby of Johns Hopkins University was the third speaker of this session and spoke on the use of breath biomarkers to measure oxidant stress. Breath ethane is the most commonly used gas and is used as a marker of lipid oxidation.
Gas chromatography is the instrumentation used for measurement.
The use of breath ethane is potentially interfered by smoking. Smokers have twice the breath ethane as non-smokers. The speaker also discussed typical coefficients of variation associated with breath ethane measurements. These methods were reviewed and several applications and limitations of each were discussed. Dr Rodriguez began his talk by noting that although many diseases are associated with oxidative stress, the necessity of knowing the location of the damage is becoming increasingly more important in order to assess and understand the individual risks associated with oxidative stress.