Behavioral test methods workshop.

A one and a half day workshop on behavioral testing was conducted in order to discuss experimental procedures and practices that may help enhance the utility of behavioral data as a reliable index of neurotoxicity and in the safety evaluation of chemical substances. The workshop was open to participation by all sectors of the neuroscience community including academia, government, testing laboratories, and industry. The level of confidence with which changes in behavior can reliably signal adverse effects on the nervous system depends, in part, on the scientific quality of the data generated.

Characterization of a microprocessor-controlled tubular multiple metered dose inhaler aerosol generator for inhalation exposures of pharmaceuticals.

A microprocessor-controlled tubular multiple metered dose inhaler (MDI) aerosol generator was constructed for the delivery of pharmaceutical aerosols to inhalation chambers. The MDIs were mounted in four cassettes containing one to four MDIs on a stepped end plate. The MDIs in each cassette were pneumatically activated at intervals that were controlled by the microprocessor.

Lack of effects of nose-only inhalation exposure on testicular toxicity in male rats.

Reductions in testicular mass, sperm motility, and mating frequency have been attributed to the stresses caused by confinement of Sprague-Dawley male rats in nose-only inhalation exposure tubes. Testicular changes, including an increase in testicular atrophy, have been detected at an increased incidence in male rats used in inhalation studies as compared with rats of the same age and strain used in oral toxicity studies. This study was designed to determine whether nose-only exposure of male rats caused testicular toxicity under conditions of cooling of the exposure room and appropriate acclimation to the exposure tubes.

Method to protect rabbit eyes and reduce potential stress from eye irritation or injury associated with exposure to vapors and particulates in inhalation studies.

Many pharmaceuticals are administered to children and adults as sprays provided in nebulizers or metered-dose inhalers. Stress associated with possible eye irritation and injury attributable to exposure to vapors and particulates during the required safety testing procedures of such medicines is a potential confounding factor in these studies. Reducing stress and the potential changes associated with stress is particularly important in safety studies involving pregnant animals because maternal stress has been known to be associated with adverse outcomes for the offspring.

Selection of a chemically defined medium for culturing adult newt forelimb regenerates.

Three commercially available tissue-culture media were evaluated for their ability to support continued growth and differentiation of 14-day regenerates of adult newt forelimbs. Serums, embryo extracts, egg ultrafiltrates, and antimicrobial agents were avoided in this analysis. The hormones insulin and L-thyroxine were added to these chemically defined media to enhance continued cellular metabolism and growth.