Correction to: Internal Medicine Point of Care Ultrasound: Indicators It's Here to Stay.

This editorial, "Internal Medicine Point of Care Ultrasound: Indicators It's Here to Stay" (DOI: 10.1007/s11606-019-05268-0), was intended to accompany "Education Indicators for Internal Medicine Point-of-Care Ultrasound: a Consensus Report from the Canadian Internal Medicine Ultrasound (CIMUS) Group".

Training of Non-expert Users Using Remotely Delivered, Point-of-Care Tele-Ultrasound: A Proof-of-Concept Study in 2 Canadian Communities.

ABSTRACT: Many physicians, particularly those practicing in remote regions, lack training opportunities to develop point-of-care ultrasound (POCUS) skills. This pretest-posttest study quantified the skill improvement of learners after participating in a virtual training program that used real-time, remotely delivered point-of-care tele-ultrasound (tele-POCUS) for teaching and learner feedback provision. Ten physicians practicing in an urban tertiary (Kingston, Ontario, Canada, n = 6) or remote care center (Moose Factory, Ontario, Canada, n = 4) completed a 3-week educational program that consisted of e-learning module review, independent image acquisition practice, and expert-guided tele-POCUS consultations. Pretraining and posttraining assessments were performed to evaluate skill enhancement in image acquisition, image quality, and image interpretation for cardiac and lung/pleura POCUS using a 5-point Likert scale. A total of 76 tele-POCUS consultations were performed during the study period. Significant improvements in image quality were noted following remotely delivered mentorship and guidance (all P < 0.01). In cardiac POCUS, pretraining and posttraining comparisons noted significant improvements in image acquisition (means, 2.69-4.33; P < 0.02), quality (means, 2.40-4.03; P < 0.01), and interpretation (means, 2.50-4.40; P < 0.02). In lung/pleura POCUS, significant improvements in image acquisition (means, 3.00-4.43; P < 0.01), quality (means, 3.23-4.37; P < 0.01), and interpretation (means, 3.00-4.40; P < 0.01) were demonstrated. Introductory ultrasound can be taught to novice users using a virtual, live-streamed training format with tele-POCUS while demonstrating significant enhancement in imaging skills.

Dendrite-derived supernumerary axons on adult axotomized motor neurons possess proteins that are essential for the initiation and propagation of action potentials and synaptic vesicle release.

Axotomy can trigger profound alterations in the neuronal polarity of adult neurons in vivo. This can manifest itself in the development of new axon-like processes emanating from the tips of distal dendrites. Previously, these processes have been defined as axonal based on their axonal morphology. This study extends this definition to determine whether, more importantly, these processes possess the prerequisite molecular machinery to function as axons. Using a combination of intracellular labeling and immunohistochemistry, we demonstrate that the distribution of voltage-gated sodium channels on these processes matches the arrangement of these channels that is necessary for the initiation and conduction of action potentials. At terminal bouton-like structures they possess key proteins necessary for the release of synaptic vesicles (SV2 and synaptophysin). Thus, axon-like processes emanating from the tips of distal dendrites represent a rearrangement of neuronal polarity whereby axotomized neurons can develop additional functional axons in vivo.

Nonuniform distribution of contacts from noradrenergic and serotonergic boutons on the dendrites of cat splenius motoneurons.

The input-output properties of motoneurons are dynamically regulated. This regulation depends, in part, on the relative location of excitatory and inhibitory synapses, voltage-dependent and -independent channels, and neuromodulatory synapses on the dendritic tree. The goal of the present study was to quantify the number and distribution of synapses from two powerful neuromodulatory systems that originate from noradrenergic (NA) and serotonergic (5-HT) neurons. Here we show that the dendritic trees of motoneurons innervating a dorsal neck extensor muscle, splenius, in the adult cat are densely, but not uniformly innervated by both NA and 5-HT boutons. Identified splenius motoneurons were intracellularly stained with Neurobiotin. Using 3D reconstruction techniques we mapped the distributions of contacts formed by NA and 5-HT boutons on the reconstructed dendritic trees of these motoneurons. Splenius motoneurons received an average of 1,230 NA contacts (range = 647-1,507) and 1,582 5-HT contacts (range = 1,234-2,143). The densities of these contacts were 10 (NA) to 6 (5-HT)-fold higher on small compared to large-diameter dendrites. This relationship largely accounts for the bias of NA and 5-HT contacts on distal dendrites and is partially responsible for the higher density of NA contacts on dendrites located more than 200 µm dorsal to the soma. These results suggest that the neuromodulatory actions of NA and 5-HT are compartmentalized and regulate the input-output properties of motoneurons according to precisely arranged interactions with voltage-dependent and -independent channels that are primarily located on small-diameter dendrites.