Biomedical subjects
Publications and source records attributed to A R Mawson.
Several lines of indirect evidence implicate vitamin A intoxication, associated mainly with impaired renal function, in the etiopathogenesis of gouty arthritis. The enzyme xanthine oxidase is involved not only in the conversion of xanthine to uric acid but also in that of retinol to its more toxic metabolite, retinoic acid. Retinoic acid should therefore be present in high concentration in hyperuricemic states.
A retrospective chart review was carried out on all spinal cord injured patients admitted to the Louisiana Rehabilitation Institute, Charity Hospital, between 1965 and 1984. In addition, former patients who could be contacted and who gave their informal consent were interviewed by telephone about the circumstances of their injury. The patients were most commonly male (86%) and black (53%); the average age at injury was 29, the most common diagnosis was complete paraplegia (44%); and the leading cause of injury was gunshot (or other penetrating) wounds (41%) followed by motor vehicle crashes (36%). These findings mirror the pattern of serious injury in Orleans Parish as a whole and point to firearms as a major health hazard in this community.
Although the possible role of hypertension and/or blood pressure variability in the causation of juvenile delinquency has not been directly investigated hitherto, there is evidence to suggest (a) that an excess prevalence of blood pressure variability rather than hypertension is the aspect of cardiovascular functioning which characterizes adolescents, and some indirect evidence suggests (b) that increased blood pressure variability rather than hypertension is associated with juvenile delinquency. Official criminal statistics reveal a marked increase in the rate of convictions of males in their early and middle teens--the time of puberty and the adolescent growth spurt. It is hypothesized that increased blood pressure variability is one aspect of the general change in growth rate and metabolism occurring at puberty. These physiologic changes, together with the simultaneous addition of various social stresses, may lower the threshold for aggression and impulsivity, thus placing the individual at greater risk of involvement in the wide spectrum of behaviors collectively termed "delinquent".
The psychophysiological literature on psychopathy is reviewed in the context of low-arousal theory. Difficulties in the theory are discussed both in general terms and specifically in relation to psychopathy. Contrary to the low-arousal theory, the data indicate that psychopaths exhibit a wider degree of variability in arousal levels and reactivity than normal indiciduals. A more accurate model of the disorder might be one in which psychopaths display a faster rate and a greater magnitude of change in physiological and behavioral activity than normals. It is suggested that psychopathy might be usefully viewed as a biochemical disturbance manifested in abnormal oscillations in neurotransmitter functioning, autonomic activity, and behavior. The literature is reexamined in light of this hypothesis, and a number of avenues for further research are discussed.
The hypothesis is presented that whales become stranded inadvertently as a consequence of seeking stimulation. The animals enter shallow water in order to roll over, bask, and rub themselves in the sand, and are trapped by the receding tide. It suggested that stimulation-seeking behavior (and stranding) reflects a general sympathetic nervous system response which may be due to a number of factors such as pain, discomfort, reproductive state, and other biorhythmic changes.
A behavioral-biochemical hypothesis is presented to explain the attenuating effect of fighting on electric-shock induced gastric ulceration and hypertension in rats. It is suggested that shock-induced gastric lesions and hypertension result from undampened oscillations in central cholinergic and adrenergic activity, respectively, and that the sensory input derived from fighting serves to reduce the amplitude of these oscillations via a process of inhibition. The hypothesis suggests that other forms of sensory input in addition to that supplied by fighting--whether self-generated or produced artificially by electrical or mechanical stimulators--would have an identical equilibrating effect on oscillations in neurotransmitter activity.