A tuna fish diet influences cat behavior.

When observed in their home cages, cats fed commercial tuna fish cat food were less active, vocalized less, and spent more time on the floor and more time eating than cats fed commercial beef cat food. There were no differences in response to human handling between the two groups. There were no differences in learning ability on a two-choice point maze or in reversal learning in the same maze between beef- and tuna-fed cats. The behavior of the groups differed in a 15-min open field test only in the number of toys contacted. Cats fed the tuna had elevated tissue levels of mercury and selenium.

Design and testing of a biocontainment system for chemical carcinogens.

A biocontainment facility was built for studies in which the chemical carcinogen N-methyl-N-nitrosourea (MNU) was instilled intrarectally in guinea pigs. The system operated by constant flow of uncontaminated air into carcinogen-contaminated animal isolation chambers and filtration through a high-efficiency particulate air (HEPA) filter prior to release into the environment. The facility was tested for efficiency of carcinogen containment by substituting for the MNU a similar concentration of a fluorescent tracer, sodium fluorescein, under standard operating procedures for carcinogen administration to guinea pigs. Wipe samples from the floor, isolation chambers, animal handlers and clothing, and intake and exhaust air samples were analyzed for fluorescein before and after intrarectal instillation of the tracer. The recovery of very low concentrations of total and respirable suspended fluorescein from sampling points within the facility and the absence of detectable fluorescein in the air downstream from the HEPA filter indicated that the facility provided adequate protection against contamination of personnel or the environment.