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Biomedical subjects

R Kent

Publications and source records attributed to R Kent.

27 records · Page 2Linked to original sources
PubMed1985

The effect of peripheral chemodenervation on the ventilatory response to potassium.

The present experiments were designed to test the hypothesis that the increase in plasma potassium which occurs during exercise acts as a stimulus to respiration via the peripheral chemoreceptors. The effect of intravenous infusion of KCl on ventilation was measured in anaesthetised cats while they were loaded with CO2 intravenously via a bubble gas exchanger. Ventilation during K+ infusion was compared with that immediately before in 'intact' and peripherally chemodenervated cats. In the 'intact' group there was a highly significant increase in ventilation of approximately 25% (+253 +/- 22 ml/min, P less than 0.001), whereas in the chemodenervated group there was no significant change (+ 17 +/- 11 ml/min) in spite of similar increases in arterial K+ concentration. The results of these experiments indicate that K+ infusions stimulate ventilation and that this effect is abolished by peripheral chemodenervation.

Animals↗
PubMed1983

Longitudinal trends in subcutaneous fat thickness during adolescence.

Longitudinal principal components (LPC) analysis is used to summarize adolescent trends in subcutaneous fat thickness at three sites (biceps, suprailiac, and abdominal). For each site, component 1 (C1) represents fatness level, and component 2 (C2) represents an increase followed by a decrease (fat wave) in fatness. Components 3-5 (retained for girls only) represent more complicated patterns of change (multiple increases and decreases). Correlations among scores for C1 for each site and among scores for C2 for each site indicate a high correspondence of fatness level and the magnitude of the fat wave. Associations between components and other indicators of maturity are apparent, indicating that serial fat patterns are controlled to some degree by influences affecting other pubescent events. Continuity between childhood fatness levels and adolescent patterns of fatness are relatively weak. Continuity between adolescent and adulthood fatness is somewhat greater.

Adipose Tissue↗
PubMed1978

Articulatory abnormalities in athetoid cerebral palsy.

This report presents cinefluorographic data on the articulation of isolated vowels, VCV nonsense utterances, and short sentences by five subjects with athetoid cerebral palsy. Articulatory abnormalities were identified from tracings of vocal tract shapes and from displacement-by-time plots of articulatory events. The most frequent abnormalities were large ranges of jaw movement, inappropriate positioning of the tongue for various phonetic segments (especially because of a reduced range of tongue movement in the anteroposterior dimension), intermittency of velopharyngeal closure caused by an instability of velar elevation, prolonged transition times for articulatory movements, and retrusion of the lower lip. The speech disorder associated with athetosis is considered with respect to a model of motor learning.

Adult↗
PubMed1975

A case study of an ataxic dysarthric: cineradiographic and spectrographic observations.

Cineradiographic and spectrographic analyses were performed to study the speech production of a subject who presented the classical neurologic signs of cerebellar lesion and who had speech characteristics like those that have been reported for ataxic dysarthria. These analyses were conducted with special attention to the deviant perceptual dimensions that have been described for ataxic speech. Examination of the cineradiographic and spectrographic records revealed conspicuous abnormalities in speaking rate, stress patterns, articulatory placements for both vowels and consonants, velocities of articulator movements, and fundamental frequency contours. In general, our physiological and acoustic observations of ataxic dysarthria were compatible with existing perceptual descriptions of this condition. The data for the subject are discussed in the light of current hypotheses concerning cerebellar participation in the regulation of skilled movement. Particular suggestions are made concerning the nature of the neuromuscular abnormalities that may underlie the aberrant motorics of ataxic dysarthria.

Cerebellar Ataxia↗