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Biomedical subjects

C Hutt

Publications and source records attributed to C Hutt.

At least 19 recordsLinked to original sources

Avascular necrosis of bone in dyskeratosis congenita.

A case of dyskeratosis congenita, a rare X-linked disorder, is presented. The patient had the classic triad of cutaneous findings: reticulated hyperpigmentation, nail dystrophy, and leukoplakia. In addition, a previously unreported finding developed, avascular necrosis of bone without systemic steroid therapy. Recognition of this disorder is important because pancytopenia and malignancy develop in up to 50 percent of patients.

Adult

Heart-rate correlates of childhood activities: play, exploration, problem-solving and day-dreaming.

Heart-rate was monitored while children were engaged in different activities. The first study examined the hypothesis that the behavioural distinction between exploration and play would be supported by the psychophysiological measure. Two-year-olds showed suppression of heart rate variability (HRV) during exploration, and even more during solution of a puzzle, suggesting that the task demands these two activities were greater than those during play. The second study demonstrated a relationship between HRV during daydreaming and during problem solving in 9-year-old children which was similar to that obtained between play and problem solving in younger children. The correlative use of HRV thus strengthened functional interpretations of behaviour.

Child

Biological bases of psychological sex differences.

The mammalian process of sexual differentiation is briefly outlined. It is argued that in becoming girl or boy there are certain constraints and biases placed on the developing individual, some of these stemming from physiological bases, others from sensory-perceptual ones. These bases in turn affect the salience environmental factors for the two sexes. The different "behavioral styles" of boys and girls are thus a consequence of the transaction between the environment and these predispositions. The psychosexual anomalies are reviewed as instructive cases. Differences in neural organization and cerebral asymmetry are considered as further evidence of sexual dimorphism in humans.

Child

Correlation of behavioural inhibition or excitation produced by bromocriptine with changes in brain catecholamine turnover.

The dopamine agonist, bromocriptine, produced either inhibition or stimulation of motor behaviour in rats depending upon the dose and time after administration. Stimulation of motor activity occurred only with high doses after a 1-2 h delay. Both inhibition and stimulation were associated with decreased turnover of dopamine in the brain. Release of noradrenaline in brain and noradrenaline plus adrenaline in adrenal varied with motor activity. It is suggested that low doses of bromocriptine inhibit behaviour by activating an inhibitory presynaptic receptor, resulting in reduced synthesis and release of dopamine, whilst high doses cause behavioural excitation by activating the post-synaptic dopamine receptor.

Animals

Cardiac arrhythmia and behaviour in autistic children.

The behavior and heart rate of autistic children were simultaneously videorecorded in a standard situation. Normal children of two age-groups were also studied. It was found that the heart rate of the autists was characteristically highly variable and more so than that of normal children of the same age or younger. This variability (arrhythmia) however, was behaviour-dependent in all children-involvement in a task resulting in suppresion of the arrhythmia. It was at a maximum in the autists during the performance of stereotyped behaviours. The functional implications of these behaviour-heart rate associations are discussed.

Arrhythmias, Cardiac