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Biomedical subjects

A Maggi

Publications and source records attributed to A Maggi.

At least 127 records · Page 7Linked to original sources
PubMed1983

[Atrial septal defect of the ostium secundum associated with incomplete left bundle branch block].

The ECG in Ostium Secundum Atrial Septal Defect (O.S. ASD) shows typically a pattern of incomplete right bundle branch block with right axis deviation and a 12 year old boy suspected of having O.S. ASD on the basis of x-ray and echocardiographic findings showed an ECG pattern of incomplete left bundle branch block. Physical examination and a phonocardiogram revealed a single second heart sound. An ECG recorded at age five showed a typical pattern consistent with O.S. ASD. The angiographic examination confirmed the suggested diagnosis. This is, to our knowledge, the first case of O.S. ASD with incomplete left bundle branch block. The conduction disorder may have abolished the fixed splitting of the second heart sound.

Bundle-Branch Block↗
PubMed1980

beta-Adrenergic regulation of alpha 2-adrenergic receptors in the central nervous system.

Incubation of rat cerebral cortical slices with the beta-adrenergic agonist isoproterenol causes an increase in alpha 2-adrenergic receptor binding in addition to a decrease in beta-adrenergic receptor binding. The effects are rapid and reversible, show a parallel time course, and are blocked by sotalol, a beta-adrenergic receptor antagonist. The beta-mediated regulation of alpha 2-receptor sensitivity at brain norepinephrine synapses may be a mechanism for the homeostatic control of central noradrenergic activity.

Adrenergic alpha-Agonists↗
PubMed1980

Differential effects of antidepressant treatment on brain monoaminergic receptors.

Chronic (21 days) antidepressant administration to rats results in a decrease in both serotonin and beta-adrenergic, but not cholinergic muscarinic, receptor binding in selected brain regions, with the frontal cortex appearing to be somewhat more sensitive to this effect. Neither nisoxetine nor fluoxetine, potent and specific inhibitors of norepinephrine and serotonin uptake respectively, caused receptor binding changes after chronic administration, suggesting that inhibition of transmitter uptake, in itself, is insufficient to cause receptor subsensitivity. In vitro experiments indicated that antidepressants are relatively weak alpha 2-receptor blocking agents, but some are potent on the alpha 1-receptor system indicating that the norepinephrine releasing potency of some antidepressants may not be mediated by blockade of presynaptic autoreceptors.

Animals↗
PubMed1978

Significance of dopamine metabolites in the evaluation of drugs acting on dopaminergic neurons.

The effect of various drugs was studied on 3-methoxytyramine (3-MT) concentrations in rat striatum. The drugs were chosen for their ability to interfere with the dopaminergic system at different levels. Dopamine (DA) acidic metabolites, i.e. homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC), were also measured. Changes of 3-MT, unlike those of DOPAC and HVA, seem to reflect the functional activity of dopaminergic neurons. In fact drugs believed to increase or decrease DA content in the synaptic cleft produce predictable changes of striatal 3-MT. Thus cocaine, nomifensine and d-amphetamine increase 3-MT concentrations while gamma-butyrolactone, alpha-methyltyrosine and apomorphine decrease it.

3,4-Dihydroxyphenylacetic Acid↗