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Biomedical subjects

J W Kerr

Publications and source records attributed to J W Kerr.

12 recordsLinked to original sources
PubMed1978

Cyanide exposure in fires.

The toxic hazard from cyanide produced in fires was assessed in casualties and in firemen exposed to the fire atmosphere. The levels of cyanide and its principal metabolite, thiocyanate, were measured in blood samples from fireman, non-fetal and fatal casualties, and from controls. Although firemen did not differ significantly from controls, casualities showed significant elevation of blood-cyanide, and in a small proportion of fatalities blood-cyanide reached toxic levels.

Cyanides↗
PubMed1978

Sodium cromoglycate and ipratropium bromide in exercise-induced asthma.

In thirteen patients with extrinsic asthma the effects of placebo, sodium cromoglycate, ipratropium bromide, and ipratropium bromide plus sodium cromoglycate were studied in a random double-blind fashion to assess their inhibitory action in exercise-induced asthma (EIA). Exercise testing consisted of steady state running on an inclined treadmill for up to eight minutes. In eight of the 13 patients studied the baseline ratio of expiratory flow at 50% vital capacity (VC) breathing helium-oxygen (V50He) to V50air was over 1.20 and they were called responders; the remaining five patients were called non-responders. There was a significantly lower baseline maximum mid-expiratory flow rate (MMEF) in non-responders (P less than 0.02) as compared to responders but no difference in forced expiratory volume in one second (FEV1) or forced vital capacity (FVC). Sodium cromoglycate (P less than 0.02), ipratropium bromide (P less than 0.01), and ipratropium bromide plus spdium cromoglycate (P less than 0.01) all significantly inhibited the percentage fall in FEV1 after exercise in the responders. Ipratropium bromide had no preventive action on non-responders, unlike sodium cromoglycate (P less than 0.05) and ipratropium bromide plus sodium cromoglycate (P less than 0.02). It is postulated that mediator release is an important factor in development of EIA in most extrinsic asthmatics, whereas cholinergic mechanisms are relevant only in those patients in whom the main site of airflow obstruction is in the large central airways.

Adolescent↗
PubMed1977

Comparision of a glutaraldehyde-modified pollen--tyrosine adsorbate with an alum-precipitated pollen vaccine in the treatment of hay fever.

Nineteen patients with hay fever symptoms received nine weekly injections of pyridine-extracted alum-precipitated grass pollen vaccine (Alavac P). The results were compared with agroup of twenty patients who received a three injection series of a glutaraldehyde-modified pollen-tyrosine vaccine (Pollinex). In both groups 65% had a subjective improvement in their symptoms and no significant difference in symptom scores was obtained throughout the pollen season. In the Pollinex group a lower incidence of systemic side effects was recorded.

Adolescent↗
PubMed1976

The effect of thymoxamine and cromolyn sodium on postexercise bronchoconstriction in asthma.

Of the 22 patients with extrinsic bronchial asthma, 13 patients developed post-exercise bronchoconstriction after treadmill exercise, whereas in 9 patients treadmill exercise had no effect on the ventilatory capacity. No statistical difference in the resting lung volumes and CO transfer factor was found between the two groups. A significant inhibition of postexercise bronchoconstriction was observed in 12 of 13 patients following thymoxamine or cromolyn sodium inhalation. Inhibition of postexercise bronchoconstriction by alpha blockade with thymoxamine suggests that increased alpha adrenergic activity in the presence of diminished beta receptor responsiveness to catecholamines, norepinephrine released during exercise could have a marked alpha agonistic effect giving rise to bronchoconstriction. It has been suggested that cromolyn sodium has a cyclic phosphodiesterase inhibiting action. This might increase levels of AMP and restore the beta receptor responsiveness to catecholamines.

Airway Obstruction↗
PubMed1976

A 12-month double-blind assessment of betamethasone valerate aerosol in the management of asthma.

A double-blind trial of the topically active corticosteroid, betamethasone valerate in aerosol form, in the control of chronic asthma is reported. The results show that this is an extremely effective therapeutic agent in non-steroid dependent but nonetheless moderately severe asthmatics. Patients were well controlled on 800 mug of betamethasone valerate daily and control was maintained over a 12-month period. This form of treatment has few undersirable side effects but there is probably an increased incidence of oropharyngeal and laryngeal candidiasis. In particular, adrenocortical suppression was not noted.

Adolescent↗
PubMed1975

Response of lymphocyte guanyl cyclase to propranolol, noradrenaline, thymoxamine, and acetylcholine in extrinsic bronchial asthma.

The lymphocyte guanyl cyclase response to alpha-agonists was studied in 10 normal people and 12 patients with bronchial asthma. In the normal subjects alpha-adrenergic stimulation with noradrenaline plus propranolol and cholinergic stimulation with acetylcholine evoked significant increases in cyclic guanosine monophosphate formation. In addition the alpha-receptor blocking drug thymoxamine produced a significant stimulation of this enzyme system, and the effects of thymoxamine and acetylcholine were additive. This suggests that receptors for cholinergic and alpha-adrenergic agents are independent. In contrast, lymphocyte guanyl cyclase activity did not show a significant response to these agents in patients with acute asthma. In asthmatic patients in remission the responses were partially restored. The significance of these results for control of bronchomotor tone and the relation of guanyl cyclase activity to cyclic adenosine monophosphate in normal subjects and patients with asthma is discussed.

Acetylcholine↗
PubMed1975

Effect of alpha receptor blocking drug, thymoxamine, on allergen induced bronchoconstriction in extrinsic asthma.

In ten patients with extrinsic bronchial asthma, allergen provoked bronchospasm was significantly inhibited by the alpha receptor blocking drug thymoxamine given intravenously. In two of these patients thymoxamine by inhalation also effectively inhibited allergen induced bronchoconstriction. It is suggested that thymoxamine may be acting either by increasing intracellular levels of cyclic AMP and thus inhibiting mediator release following allergen challenge or by modifying the airways response to these mediators by altering the bronchomotor tone. The variable responses recorded after allergen challenge in presence of alpha blockade with thymoxamine suggests that the dominant effect is on the bronchomotor tone rather than the mediator release.

Administration, Intranasal↗