Independent sector. Independent training.
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Biomedical subjects
Publications and source records attributed to S Hutchison.
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The generation of toxic oxygen metabolites is more usually associated with inflammation. However, pathological free radical reactions can cause tissue damage by adversely affecting prostacyclin (PGI2) synthesis allowing initiation of coagulation. We have assessed changes in the red cell defence to toxic oxygen metabolite generation, viz measurement of glutathione concentration (GSH) and superoxide dismutase activity (SOD). GSH and SOD were measured in 20 patients with peripheral arterial disease, 22 patients with vasculitis, and 11 patients with angina, and compared to 17 matched controls. The 53 subjects with arterial disease had significantly lower SOD levels: in contrast GSH levels were significantly higher. Extracellularly plasma thiol levels (PSH) were low and caeruloplasmin (Cp) levels were high. We suggest that free radical pathology exists not only in inflammatory vascular disease but also in atherosclerosis.
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The viability of the conditioned flavor aversion test as a behavioral index of the toxicity of physostigmine, an anticholinesterase agent, was evaluated in a series of three experiments. Experiments 1 and 2 used the flavor aversion paradigm and Experiment 3 used a more traditional behavioral testing paradigm in which the effect of physostigmine on a specified set of behaviors was measured. In the flavor aversion paradigm, the rats were allowed to consume 0.5% saccharin solution before being injected with one of various doses of physostigmine (0.025--0.50 mg/kg) or saline. They were subsequently tested for a learned flavor aversion by means of a one-bottle test in Experiment 1 and a two-bottle test in Experiment 2. In the behavioral testing paradigm used in Experiment 3, each rat was injected with one of various doses of physostigmine within the range of those used in the prior experiments, and thirty minutes later was placed in a chamber for observation for 15 minutes. The procedures of Experiment 3 were much more time consuming than those of Experiments 1 and 2. By the two-bottle aversion test of Experiment 2, a dose as low as 0.05 mg/kg of physostigmine produced a reliable flavor aversion which persisted for three extinction test trials. On the other hand, robust and reliable behavioral differences of decreased rearing and consumption of water in Experiment 3 were only evident in rats given 0.25 mg/kg of physostigmine. We conclude that the flavor aversion test is a simple and sensitive behavioral measure of toxicity.