Biological Methods

Communication 4 contains four reports on analyzing complex mixtures. Three reports address analytical approaches to indentifying toxic compounds. One describes statistical approaches to analysis of interaction. (1) Immunoaffinity Chromatography in the Analysis of Toxic Effects of Complex Mixtures, William E. Bechtold (2) Stationary-Phase Programming for Liquid Chromatography: A New Concept for Separating Complex Mixtures, John G. Dorsey (3) Supercritical Separation and Molecular Bioassay Technologies Applied to Complex Mixtures, David L. Springer (4) Using the Parallel Coordinate Axis System to Analyze Complex Mixtures: Determining Biological Activity and Interactions Among Components, Chris Gennings.

Dr. Fennell at the Chemical Industry Institute of Toxicology sought to develop new methods for improving the detection of formaldehyde-DNA adducts in exposed cells and tissues. The investigator treated formaldehyde-DNA adducts with sodium bisulfite, a compound that reacts with these adducts and traps them as stable compounds, and then tested different analytical techniques for separating and detecting the adducts. He exposed pure DNA, cell nuclei, and cells in culture to formaldehyde and treated them with sodium bisulfite under a variety of experimental conditions.

This document contains two reports by Drs. McCool and Samet and their colleagues who were funded to develop and test methods for measuring ventilation in freely mobile subjects at home or at work. Drs. Dennis McCool and Domyung Paek at the Memorial Hospital in Rhode Island measured ventilation with a body surface displacement (BSD) model. Each subject wore wide elastic bands containing coated wire coils around the chest and abdomen and had special magnets affixed to the breastbone and navel, which yielded data about their breathing patterns, breath frequency, and ventilation. In the second study, Dr. Jonathan Samet and colleagues at Johns Hopkins University wanted to develop methods for estimating ventilation from heart rate for future epidemiologic studies. They used the Heartwatch, a portable, commercial device combining a small transmitter worn on the subject's chest with a wristwatch-style receiver that records heart rate.

The human health effects that result from breathing air pollutants depend on the amount of pollutant inhaled from the air (exposure dose) and the amount of inhaled material that stays in the respiratory tract (retained dose). Because the retained dose of a pollutant may damage the respiratory tract and cause disease, it is a key factor for determining appropriate government regulations for air pollutants. Drs.

This report describes a study by Drs. Ultman and Ben-Jebria to develop a chemiluminescent ozone analyzer and constructed an ozone bolus generator with the goal of using bolus concentration-response methods to noninvasively measure the longitudinal distribution of ozone absorption in human lungs. The analyzer was based on the chemiluminescent reaction between 2-methyl-2-butene and ozone. Validation of the system was performed in excised pig and sheep tracheas, and the resulting absorption coefficient was computed.