Measurements of ventilatory capacity have been made in 664 healthy school-children (ages 5-16 years) of European, Afrocaribbean and Indian stock living in the same environment in inner-city Nottingham: 100%, 95% and 80% of these three groups respectively had been born in the UK. The ventilatory capacity data have been analyzed by logarithmic regressions on stature. For forced vital capacity (FVC) and forced expiratory volume (FEV1) a large difference between European and Indian children was found, amounting to 13% at a given stature. The Afrocaribbean children have values similar to those of the Indians. There were no material ethnic differences for peak expiratory flow rate or for FEV1/FVC(%). The differences in FVC and FEV1 appear to be attributable to constitutional rather than environmental influences.

Adolescent↗

PubMedDate not supplied

Flow-volume curves during hand immersion in water at 5 degrees C (the cold pressor test).

Seven healthy subjects immersed a hand for 2 min in cold water at 5 degrees C (the standard cold pressor test) with and without beta-adrenoceptor blockade. Control immersions in warm water were also performed. The maximal and partial flow-volume curves as well as the arterial blood pressure, heart rate and body and hand temperatures were recorded before, during and after the hand immersion. The blood pressure rose significantly during the cold pressor test, but the airflow variables did not change significantly, whether or not propranolol had been given. It is concluded that, even though the standard cold pressor test induces sympathetically-mediated cardiovascular responses, it does not produce a bronchodilatation.

Airway Resistance↗

PubMedDate not supplied

Beta-adrenoceptor blockade and cardiovascular response to the cold pressor test.

Seven healthy subjects immersed a hand in random order in either warm water or in cold water at 5 degrees C for 2 min, after taking orally a single dose of 120 mg of propranolol or a placebo in a double blind fashion. The cold stress resulted in a significant increase in blood pressure and the rate pressure product without a change in heart rate. Beta-adrenoceptor blockade did not affect the pressor response the cold. The changes induced by the cold stress in the cardiovascular variables in the placebo and propranolol experiments were not statistically different. The highest rate pressure product during the cold pressor test was about 109 units. This was well below the pain threshold value of about 200 found during exercise in patients with ischaemic heart disease. In the recovery phase, the cardiovascular variables reverted to pre-immersion values within 1 min inspite of continued low hand skin temperature.

Blood Pressure↗

PubMedDate not supplied

Forced expiratory flow-volume curves during the application of lower-body negative pressure.

Ten normal subjects were studied during supine rest and quiet standing, and when exposed, supine, to lower-body negative pressure (LBNP) of 30, 40 and 50 mmHg, each for a period of 7 min, in random order. Their partial and complete flow-volume curves, heart rate and blood pressure were recorded during the last 3 min in each condition. The expected reflex cardiovascular responses to the decrease in central blood volume during standing and during LBNP were seen. The forced vital capacity was somewhat greater during standing and during LBNP than while supine. The airflow variables measured from the flow-volume curve-except MEF25% (partial)--were significantly increased during progressive LBNP but did not reach the raised values found when the posture changed from supine to standing. The observations suggest that besides the redistribution of the central blood volume to the periphery, other factors must contribute to the increase in airflows during standing.

Adult↗