Gerald N. McEwen

Learn More
The potential for the cis and trans isomers of urocanic acid to produce DNA damage was measured by assays for DNA binding (32P-postlabeling assay), for induction of DNA repair (unscheduled DNA synthesis assay) and induction of mutations (Salmonella typhimurium and Escherichia coli plate-incorporation assays). These assays did not detect any evidence of a(More)
BACKGROUND/PURPOSE Trans-urocanic acid is isomerized to cis-urocanic acid (C-UCA) by ultraviolet radiation. C-UCA suppresses immunity in vitro and in vivo in animals; its effect on human skin is unknown. We sought to determine whether its topical application to normal skin suppresses induction of immunity to dinitrochlorobenzene (DNCB). METHODS Forty(More)
A protocol to evaluate the ocular irritation, staining, and embedding potential of FD&C colours (Yellow No. 5, Blue No. 1, Blue No. 1 Aluminium Lake) produced by repeated topical application to rabbit eyes is described. Test materials (3%, w/v in aqueous vehicle) were administered once daily, for a total of 21 days, to the conjunctival sac of the right eye(More)
MCEWEN, G. N.,JR., AND J. E. HEATH. Thermoregulatory responses to preoptic cooling in unrestrained rabbits. 227 (4) : 954-957. 1974.Rabbits at ambient temperatures within the thermal neutral zone show two different metabolic responses to preoptic cooling. One response type is defined by a preoptic thermal sensitivity that shifts with ambient temperature and(More)
Methods for measuring bone-blood flow are often time-consuming, tedious, single-point measurements which require sacrifice of the animal. An impedance plethysmographic technique is described which can be used to quantify temporal bone marrow blood flow changes. Results obtained with the impedance technique compare favorably with the data from simultaneously(More)