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Biomedical subjects

K I Campbell

Publications and source records attributed to K I Campbell.

10 recordsLinked to original sources
PubMed1986

Failure to demonstrate schedule-induced hyperphagia with a fixed time 1-minute water delivery schedule.

The reduction of an animal's body weight to 80% of its Free Feeding Weight (FFW) is purported to be an important factor in the generation of schedule-induced behaviour. However, the importance of this factor in schedule-induced hyperphagia is unclear. Experimental studies in schedule-induced hyperphagia reported conflicting results. The aim of the present series of five experiments was to clarify the several conflicting factors in the generation of schedule-induced hyperphagia. Rats reduced to 80% FFW by water restriction and on a Fixed Time (FT) 1-min water delivery schedule showed that body weight reduction, water delivery schedule, size and distance of pellets, and order of schedule presentation were not important factors in the generation of schedule-induced hyperphagia. The failure of the present series of experiments to demonstrate schedule-induced hyperphagia suggests that this behaviour may be a specific class of schedule-induced behaviour that can only be demonstrated under the Bellingham, Wayner and Barone experimental paradigm.

Animals↗
PubMed1977

Embryotoxicity of irradiated and nonirradiated catalytic convertertreated automotive exhaust.

This study was undertaken to examine the relative embryotoxicity in chick embryos of photochemically reacted and unreacted diluted automotive exhaust emissions from a system equipped with a catalytic converter. Clean air controls and H2SO4 aerosol controls equivalent in concentration to those found in the catalytic exhaust atmosphere were also studied. From day 1 through day 14 of development, continuous exposure to nonirradiated exhause resulted in decreased survival, lowered embryonic weight, a small increase in heart/body weight ratio, and altered hematocrit and serum enzyme activities (LDH and GOT). Irradiated exhaust had little effect on survival or on embryonic weight but resulted in a higher liver/body weight ratio as well as altered hematocrit and serum enzyme activities. Interactions or cumulative effects of different compositions of exhaust atmospheres may play a role in differing biological responses between unreacted and irradiated exhaust. Sulfuric acid aerosol had a minimal effect on survival and resulted in only a slight decrease in embryonic weight and serum LDH activity, with no other apparent effects. In previous studies where the catalytic converter was not used, more pronounced effects on survival, increased heart/body weigh ratio, elevated serum GPT activity, and liver discoloration were observed. Thus, the introduction of an oxidizing catalytic converter appeared to alleviate some but not all of the embryotoxic effects of automotive exhaust.

Aerosols↗
PubMed1975

Dermal irritancy of metal compounds. Studies with palladium, platinum, lead, and manganese compounds.

Dermal irritancy of 14 materials, including several compounds of palladium, platinum and lead, and methylcyclopentadienyl manganese tricarbonyl, plus deionized water (negative control) and glacial acetic acid (positive control), was tested on male albino rabbits weighing 2 to 3 kg. Procedures and evaluation criteria were adopted from those in use by the National Institute for Occupational Safety and Health. Five materials were evaluated as unsafe for intact or abraded skin contact as judged by severity of responses: glacial acetic acid (C3H5PDCl)2, (NH4)2PdCl4, (NH4)2PdCl6, and PtCl4; one as safe for intact, but not for abraded, skin: K2PdCl6; and two as safe for intact skin but not for abraded skin unless protected: K2PdCl4 and PdCl2. The remainder were evaluated as safe for intact or abraded skin contact (irritancy grade less than 1 on a scale of 4): H2O, Pd(NH3)2Cl2, PdO, PtO2, PtCl2, PbCl2, PbO, MMT.

Acetates↗