The use of ultrasound in educational settings: what should we consider when implementing this technique for visualisation of anatomical structures?

Ultrasound is a well-established medical imaging technique with pioneering work conducted by Professor Ian Donald and his colleagues at the University of Glasgow, from the mid-1950s onwards, in terms of introducing it as a diagnostic tool in the field of obstetrics and gynaecology. Since then, ultrasound has been extensively used in clinical and research settings. There are few imaging techniques that have undergone such a fast and thriving evolution since their development. Nowadays, diagnostic ultrasound benefits from two-dimensional (2D), three-dimensional (3D), four-dimensional (4D), and a variety of Doppler modes with technologically advanced transducers (probes) producing images of high anatomical fidelity. In the future, there may even be a place for ultrasound in molecular imaging allowing for visualisation at the microscale. Ultrasound is characterised by real-time non-invasive scanning, relative ease of administration, and lack of ionising radiation. All of these features, make ultrasound an appealing option in educational settings for learning topographic anatomy and potentially enhancing future clinical practice for vocational learners. Sophisticated, but relatively inexpensive, portable handheld devices have also contributed to point-of-care ultrasound (POCUS) becoming the norm for bedside and pre-hospital scanning. It has been argued that ultrasound will become the next stethoscope for healthcare professionals. For this to become a reality, however, training is required on increasing familiarity with knobology, correct use of the machine and transducers, and accurate interpretation of anatomy followed by identification of pathologies. The above require incorporation of ultrasound teaching in undergraduate curricula, outwith the realm of opportunistic bedside learning, accompanied by consideration of ethical topics such as the management of incidental findings and careful evaluation of its pedagogical impact cross-sectionally and longitudinally

Catecholamine modulatory effects of nepicastat (RS-25560-197), a novel, potent and selective inhibitor of dopamine-β-hydroxylase

1. Inhibitory modulation of sympathetic nerve function may have a favourable impact on the progression of congestive heart failure. Nepicastat is a novel inhibitor of dopamine-β-hydroxylase, the enzyme which catalyses the conversion of dopamine to noradrenaline in sympathetic nerves. The in vitro pharmacology and in vivo catecholamine modulatory effects of nepicastat were investigated in the present study. 2. Nepicastat produced concentration-dependent inhibition of bovine (IC(50)=8.5±0.8 nM) and human (IC(50)=9.0±0.8  nM)dopamine-β-hydroxylase. The corresponding R-enantiomer (RS-25560-198) was approximately 2–3 fold less potent than nepicastat. Nepicastat had negligible affinity (>10 μM) for twelve other enzymes and thirteen neurotransmitter receptors. 3. Administration of nepicastat to spontaneously hypertensive rats (SHRs) (three consecutive doses of either 3, 10, 30 or 100 mg kg(−1), p.o.; 12 h apart) or beagle dogs (0.05, 0.5, 1.5 or 5 mg kg(−1), p.o.; b.i.d., for 5 days) produced dose-dependent decreases in noradrenaline content, increases in dopamine content and increases in dopamine/noradrenaline ratio in the artery (mesenteric or renal), left ventricle and cerebral cortex. At the highest dose studied, the decreases in tissue noradrenaline were 47%, 35% and 42% (in SHRs) and 88%, 91% and 96% (in dogs) in the artery, left ventricle and cerebral cortex, respectively. When tested at 30 mg kg(−1), p.o., in SHRs, nepicastat produced significantly greater changes in noradrenaline and dopamine content, as compared to the R-enantiomer (RS-25560-198), in the mesenteric artery and left ventricle. 4. Administration of nepicastat (2 mg kg(−1), b.i.d, p.o.) to beagle dogs for 15 days produced significant decreases in plasma concentrations of noradrenaline and increases in plasma concentrations of dopamine and dopamine/noradrenaline ratio. The peak reduction (52%) in plasma concentration of noradrenaline and the peak increase (646%) in plasma concentration of dopamine were observed on day-6 and day-7 of dosing, respectively. 5. The findings of this study suggest that nepicastat is a potent, selective and orally active inhibitor of dopamine-β-hydroxylase which produces gradual modulation of the sympathetic nervous system by inhibiting the biosynthesis of noradrenaline. This drug may, therefore, be of value in the treatment of cardiovascular disorders associated with over-activation of the sympathetic nervous system, such as congestive heart failure