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Biomedical subjects

J Britton

Publications and source records attributed to J Britton.

176 records · Page 10Linked to original sources
PubMed1984

Comparison of cumulative and non-cumulative techniques to measure dose-response curves for beta agonists in patients with asthma.

It has been suggested that the use of a cumulative technique to obtain bronchodilator dose-response curves will cause a greater response than a non-cumulative technique, because sequential doses of drug will penetrate further into the lung. To test this hypothesis we have compared cumulative and non-cumulative dose-response curves for inhaled isoprenaline in 10 subjects with stable asthma, measuring FEV1, forced vital capacity (FVC), and peak expiratory flow rate (PEFR). With both techniques there was an increased response with increasing doses of isoprenaline for all the dose-response curves except for the non-cumulative PEFR response, which reached a plateau with the 20 micrograms dose. The area under the dose-response curve for FEV1 was significantly greater after cumulative administration of isoprenaline than with the non-cumulative technique. The increase in FVC and PEFR tended to be greater with the cumulative technique but the differences were not significant. This study confirms that the airway response to an inhaled beta agonist may be greater when a cumulative inhalation technique is used.

Adult↗
PubMed1983

Contrast media and bronchospasm: a study with iopamidol.

Conventional radiological contrast media given intravenously are known to produce bronchospasm in the majority of patients, even though this is rarely clinically apparent. We have found that this phenomenon is much less pronounced with the new, low-osmolality contrast medium iopamidol. If the mechanism underlying the clinically silent bronchospasm observed with the conventional media is the same as that underlying the occasional life-threatening or fatal bronchospasm, then this observation is of considerable importance.

Bronchial Spasm↗
PubMed1981

Effect of inhaled alpha-blocker on airflow obstruction in asthma.

A controlled study of the effect on airflow obstruction of 30 mg of the alpha-blocker thymoxamine given by inhalation is reported in 10 patients with chronic stable asthma. No significant change in peak expiratory flow rate was seen with either thymoxamine or placebo in any patient. Alpha-adrenergic receptors are therefore unlikely to contribute significantly to resting bronchomotor tone in chronic stable asthma.

Adult↗
PubMed1978

Evidence for the presence of two sympatric species of mice (genus Mus L.) in southern France based on biochemical genetics.

Populations of mice established outdoors as well as indoors have been investigated at 24 loci using starch gel electrophoresis. Two reproductively isolated groups are recognized, one of which is referable to a house mouse subspecies, Mus musculus brevirostris, and the other to a different species. Mus spretus, contrary to the view of Schwarz and Schwarz that only one species of Mus is present in the Mediterranean Basin. The genetic distance between these two groups is larger than between any pair of investigated subspecies of M. musculus. M. m. brevirostris is biochemically almost indistinguishable from M. m. domesticus. On the other hand, M. spretus exhibits several allelic variants unknown or at most very infrequent in M. musculus, as for instance at the lactate dehydrogenase B-chain locus.

Animals↗
PubMed1976

[Mice of southern France: genetic characterization of two groups of sympatric populations].

An electrophoretic survey of five proteins (lactate dehydrogenase, isocitrate dehydrogenase, esterase-1, esterase-2, albumin) shows that there are two groups of populations strongly (or completely) reproductively isolated. The first group does not differ from Mus musculus L. The second exhibits several new biochemical traits and should probably be considered a different species.

Animals↗