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Biomedical subjects

J E Cotes

Publications and source records attributed to J E Cotes.

At least 91 records · Page 5Linked to original sources
PubMed1978

Variations in the lung size of children in Papua New Guinea: genetic and environmental factors.

In Papua New Guinea, rural village children of both sexes living in the highlands (1500--2000 m) were found to have mean values of forced vital capacity 27 per cent greater than children at sea level. Urban children with an apparently lower level of habitual activity had a lung size similar to that of rural children living at the same altitude. In a number of healthy children of coastal parents reared in the highlands and of highland parents reared on the coast, the size of the lung was, in general, appropriate for the altitude rather than for the parentage. These findings suggest that the highland--coastal difference is probably environmental rather than genetic in origin.

Adolescent↗
PubMed1978

Cardiac output during submaximal exercise in New Guineans: the relation with body size and habitat.

Cardiac performance in moderate bicycle exercise has been measured in five groups of New Guineans (N = 161). Men and women in both coastal and highland (2000 m) locations were studied, as well as a group of highland men after migration to the coast. The results have all been standardized to an oxygen consumption of 1 1.min(-1). Cardiac output values are similar to those previously quoted for Europeans; a significant positive correlation with body size is found, and resident highlanders appear to have slightly larger cardiac outputs (+4%) and larger stroke volumes (+10%) after adjustment for body size, but this is not because they have larger hearts. The highland migrants at sea-level share none of the 'altitude' characteristics of the highland residents and, after size-adjustment, correspond with the lowlanders. The cardiac frequencies of the lowland women are higher than the other groups (+15 beats.min(-1)) after adjustment for differences in body size. Their values are close to those found previously for moderately active Europeans, while all the other New Guinean subjects have lower cardiac frequencies probably because of their greater habitual activity.

Adaptation, Physiological↗
PubMed1977

Ventilatory capacity if healthy Chinese children: relation to habitual activity.

Ventilatory capacity, including forced expiratory volume (FEV 1-0) and forced vital capacity (FVC), and selected anthropometric indices have been obtained for 36 boys and 19 girls aged 5-10 years from a working class district in Kowloon. The ventilatory capacity is related to stature and is 13 per cent larger for boys than girls. After allowing for stature and sex the residual variation is significantly reduced by also allowing for the children's habitual activity. The ventilatory capacity of the more active children, including those who have lived all their lives in squatter huts on the hillsides, is on average 8 per cent larger than for the inactive children including those who have lived all their lives in tenement flats with lifts. The groups are apparently similar with respect to income, dietary pattern, intelligence and disease incidence, so that findings provide independent support for the hypothesis that the level of habitual activity during childhood contributes to the ventilatory capacity. The absolute level of ventilatory capacity resembles that of Nepalese children and differs from that of some other groups.

Activities of Daily Living↗
PubMed1977

Ventilation, cardiac frequency and pattern of breathing during exercise in men exposed to O-chlorobenzylidene malononitrile (CS) and ammonia gas in low concentrations.

Ventilation minute volume, tidal volume and cardiac frequency during submaximal exercise have been measured in healthy young soldier volunteers exposed to O-chlorobenzylidene malononitrile (CS) and ammonia gas in concentrations respectively of 0.16 to 4.4 mg.m(-3) and 50 to 344 mg.m(-3). The response of ventilation minute volume to the two gases is apparently similar; both gases cause a reduction of, on average 6%. With low doses this reflects a diminution in respiratory frequency whereas with higher doses it is due to a reduction in tidal volume which is accompanied by tachypnoea. The findings may result from stimulation successively of receptors in the larynx and of irritant receptors in the large airways of the lung. The pain which is a feature of exposure to CS but not to ammonia is due to stimulation of other so far unidentified receptors. Neither gas has a direct effect upon the exercise cardiac frequency.

Adolescent↗
PubMed1977

Clinical improvement of patients with emphysema after radiotherapy.

In advanced emphysema the reduced lung retractive force permits dynamic compression of the airways during expiration; this gives rise to breathlessness which is often refractory to conventional remedies. Radiotherapy causes shrinkage of lung tissue and has therefore been given as treatment to 10 patients with emphysema. They have been followed for two years, during which time three have died from various causes, but no adverse effect of radiotherapy has been observed. All the patients at some time experienced a reduction in breathlessness on exertion and an increase in the range of their daily activities; the distensibility of their lungs was on average reduced but the response to test exercise was not altered. The possibility that the clinical improvement may have been a placebo effect is now being investigated.

Aged↗
PubMed1975

The ventilatory cost of activity.

The energy cost of activity, depending on its intensity, varies between 6 and 50 kJ min-1 with average values for essential daily tasks and for hard work respectively of 12 and 28 kJ min-1. The levels of ventilation required to sustain these activities are, on average, 15 and 33 1 min-1 with an overall range of +/- 30%. Additional ventilation is needed for speech. The requirements for individual activities are reviewed.

Energy Metabolism↗