Does genetic variation within adrenergic pathways determine in vivo effects of presynaptic stimulation in humans?
Locally infused tyramine produced dose-dependent pressor responses, predicted by family history of hypertension, sex, and genetic variants at loci, particularly CHGB, that encode the biosynthesis, storage, and metabolism of catecholamines. Such variants may influence the complex heritability of adrenergic responses and perhaps hypertension.
High-volume surgeons exhibited certain differences in technique compared with low-volume surgeons. After adjusting for these differences, the strength of the volume-outcome relationship previously found was reduced only slightly, suggesting that other factors are also involved.