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Biomedical subjects

G Wannan

Publications and source records attributed to G Wannan.

4 recordsLinked to original sources

Gender differences in rates and correlates of suicidal behaviour amongst child psychiatric outpatients.

Childhood suicide is an increasing problem in Western society. Identification of those at risk of suicidal behaviour is of priority to identify children with consequent mental suffering, and prevent successful attempts. The study determined factors associated with suicidal ideas, attempts or threats in 5426 psychiatric outpatients aged between 8 and 17 years who attended a British teaching hospital. Multivariate logistic regression analyses were performed by sex on the data from the standard department questionnaire. Substance abuse, depression and disturbed relationships with adults were predictors of suicidal behaviour for both sexes. For female subjects, antisocial behaviour was also associated. In girls alone, depression had significant interaction effects with substance abuse and conduct disorder. Possible reasons for these differences are discussed.

Adolescent↗

Alpha-adrenoceptor blocking properties of vesamicol.

The side-effects of vesamicol, an inhibitor of acetylcholine storage, on alpha 1- and alpha 2-adrenoceptors have been studied in the isolated rat vas deferens. Antagonism of alpha 1-adrenoceptors was determined from the ability of vesamicol to reduce contractions elicited by exogenous noradrenaline. Antagonism of alpha 2-adrenoceptors was determined from the ability of vesamicol to block the inhibitory effects of the alpha 2-adrenoceptor agonist clonidine on electrically evoked twitches. In the absence of noradrenaline uptake block, (-)-vesamicol, the isomer active at cholinergic synapses, produced a leftward shift of the noradrenaline concentration-effect curve. This effect was abolished by desipramine suggesting that it is due to an ability of (-)-vesamicol to block uptake1. In the presence of noradrenaline uptake blockers, (-)-vesamicol produced a competitive, non-selective block of both alpha 1- and alpha 2-adrenoceptors with a Kd of around 40 microM (pA2 4.4). (+)-Vesamicol, the isomer that has no activity at cholinergic synapses, was equipotent with the (-)-isomer for blocking alpha 2-adrenoceptors. In addition to its alpha-adrenoceptor antagonist activity, (-)-vesamicol augmented the maximum response of the tissue to exogenous and endogenous noradrenaline. This study was unable to determine the exact nature of this effect. We suggest that the alpha-adrenoceptor blocking activity of vesamicol is a function of the phenylpiperidino moiety of the molecule.

Adrenergic alpha-Antagonists↗