Manufacture and measurement of nitrogen oxides.

A decade of research has identified nitric oxide as a unique endogenous biologic mediator with functions as diverse as vasodilation, macrophage cytotoxicity, platelet adhesion, and memory formation. Measurement devices, previously used in research on atmospheric nitrogen oxides, are being adapted for and applied to clinical situations without approval, regulation, or rigorous testing, and with little understanding of how the devices work or their limitations. This article discusses the chemistry, manufacture, and measurement of nitrogen oxides.