Development, implementation, and perceptions of a 3D-printed human skull in a large dental gross anatomy course.

Skull anatomy is a difficult region for anatomy students to learn and understand but is necessary for a variety of health professional students. To improve learning, a 3D-printed human skull was developed, produced, and distributed to a course of 83 dental students for use as a take-home study tool over the 10-week anatomy course. The 70% scale human skull derived from CT data had a fully articulating mandible, simulated temporomandibular joint, and accurate cranial structures. At the course end, students completed a perception survey and responses were compared with those who made a grade of A, B, or C in the course. Students overall reported using the model less than 3 h per week, but those who scored an A in the course reported using the model more frequently than those who scored a B or C. Free responses revealed that students used the model in a variety of ways, but found that the model was quick and easily accessible to check understanding while studying at home in the absence of direct observation by faculty. Overall, this study provides evidence on the feasibility of large-scale 3D printing and the benefits of the use of a 3D-printed model as a take-home study aid.

Survey response rates in health sciences education research: A 10-year meta-analysis.

Growth in the online survey market may be increasing response burden and possibly jeopardizing higher response rates. This meta-analysis evaluated survey trends over one decade (2011-2020) to determine: (1) changes in survey publication rates over time, (2) changes in response rates over time, (3) typical response rates within health sciences education research, (4) the factors influencing survey completion levels, and (5) common gaps in survey methods and outcomes reporting. Study I estimated survey publication trends between 2011 and 2020 using articles published in the top three health sciences education research journals. Study II searched the anatomical sciences education literature across six databases and extracted study/survey features and survey response rates. Time plots and a proportional meta-analysis were performed. Per 2926 research articles, the annual estimated proportion of studies with survey methodologies has remained constant, with no linear trend (p > 0.050) over time (Study I). Study II reported a pooled absolute response rate of 67% (95% CI = 63.9-69.0) across 360 studies (k), totaling 115,526 distributed surveys. Despite response rate oscillations over time, no significant linear trend (p = 0.995) was detected. Neither survey length, incentives, sponsorship, nor population type affected absolute response rates (p ≥ 0.070). Only 35% (120 of 339) of studies utilizing a Likert scale reported evidence of survey validity. Survey response rates and the prevalence of studies with survey methodologies have remained stable with no linear trends over time. We recommend researchers strive for a typical absolute response rate of 67% or higher and clearly document evidence of survey validity for empirical studies.

Radiology for anatomy educators: Success of an online, 2-day course for radiology training.

Incorporation of radiology training into anatomy education from community college to health professional schools is becoming increasingly popular. However, anatomy educators generally lack training in common radiology modalities, including X-ray, CT, MRI, and ultrasound. Professional development or continuing education courses provide current and new educators the chance to gain new skills within a short timeframe. Here, a 2-day, online course for anatomy educators was created. The goals of which were for the participants: to gain basic knowledge of different radiology modalities, recognize normal radiographic images, and apply that information to common diseases or injuries in interactive case studies. Each day focused on different modalities, where Day 1 studied X-ray, CT, and MRI; and Day 2 studied Ultrasound. A 10-question pre- and post-test was taken by attendees for each day of instruction on a voluntary basis. Following the completion of the course, attendees were provided a survey to determine their perceptions on course content and knowledge acquired. Most attendees instructed undergraduates at 4-year universities, though several attendees came from community colleges and high schools. All attendees showed a significant improvement in knowledge from their pre- to post-test scores in X-ray, CT, MRI, and ultrasound following training. This was also reflected in their survey responses, where attendees felt the course was effective in increasing their knowledge and confidence in radiology. Overall, this study demonstrates the effectiveness of online continuing education courses and the need for more introductory radiology courses for anatomy educators.

Faculty retirements will likely exacerbate the anatomy educator shortage.

Medical education has reported a shortage of anatomy educators since the 1960s. While the faculty pipeline has recently been explored, insights into retirement intentions, a key driver of faculty turnover, have yet to be investigated. With the mean age of anatomists rising, knowledge of retirement intentions among current educators is essential to understanding the anatomy educator shortage. This study explored the retirement intentions of current anatomy educators and their likely effects on the workforce. Surveys were distributed to department heads and the American Association for Anatomy (AAA) membership to inquire about job postings from 2018-2020 and retirement intentions, respectively. Department heads sought to fill open positions due to faculty retirements (36%, 15 of 42), faculty relocations/sabbaticals/new responsibilities (31%), and brand new positions (24%). The retirement intentions survey revealed that 61% (23 of 38) of faculty '55 and older' intend to retire within five years. Based on the extrapolation of AAA membership data, estimates suggest that almost twice as many anatomy faculty could retire per year (n = 40) over the next five years compared to the estimated number of annual PhD graduates (n = 22) likely to enter the workforce. Factors driving retirement intentions were overwhelmingly age and finances, followed by job satisfaction and family. The creation of new anatomy educator positions to address increased student enrollments and new health sciences programs is likely to place even greater strain on workforce demands.

Correlating Spatial Ability With Anatomy Assessment Performance: A Meta-Analysis.

Interest in spatial ability has grown over the past few decades following the emergence of correlational evidence associating spatial aptitude with educational performance in the fields of science, technology, engineering, and mathematics. The research field at large and the anatomy education literature on this topic are mixed. In an attempt to generate consensus, a meta-analysis was performed to objectively summarize the effects of spatial ability on anatomy assessment performance across multiple studies and populations. Relevant studies published within the past 50 years (1969-2019) were retrieved from eight databases. Study eligibility screening was followed by a full-text review and data extraction. Use of the Mental Rotations Test (MRT) was required for study inclusion. Out of 2,450 screened records, 15 studies were meta-analyzed. Seventy-three percent of studies (11 of 15) were from the United States and Canada, and the majority (9 of 15) studied professional students. Across 15 studies and 1,245 participants, spatial ability was weakly associated with anatomy performance (rpooled  = 0.240; CI at 95% = 0.09, 0.38; P = 0.002). Performance on spatial and relationship-based assessments (i.e., practical assessments and drawing tasks) was correlated with spatial ability, while performance on assessments utilizing non-spatial multiple-choice items was not correlated with spatial ability. A significant sex difference was also observed, wherein males outperformed females on spatial ability tasks. Given the role of spatial reasoning in learning anatomy, educators are encouraged to consider curriculum delivery modifications and a comprehensive assessment strategy so as not to disadvantage individuals with low spatial ability.

Perlecan Domain-V Enhances Neurogenic Brain Repair After Stroke in Mice.

The extracellular matrix fragment perlecan domain V is neuroprotective and functionally restorative following experimental stroke. As neurogenesis is an important component of chronic post-stroke repair, and previous studies have implicated perlecan in developmental neurogenesis, we hypothesized that domain V could have a broad therapeutic window by enhancing neurogenesis after stroke. We demonstrated that domain V is chronically increased in the brains of human stroke patients, suggesting that it is present during post-stroke neurogenic periods. Furthermore, perlecan deficient mice had significantly less neuroblast precursor cells after experimental stroke. Seven-day delayed domain V administration enhanced neurogenesis and restored peri-infarct excitatory synaptic drive to neocortical layer 2/3 pyramidal neurons after experimental stroke. Domain V's effects were inhibited by blockade of α2ß1 integrin, suggesting the importance of α2ß1 integrin to neurogenesis and domain V neurogenic effects. Our results demonstrate that perlecan plays a previously unrecognized role in post-stroke neurogenesis and that delayed DV administration after experimental stroke enhances neurogenesis and improves recovery in an α2ß1 integrin-mediated fashion. We conclude that domain V is a clinically relevant neuroprotective and neuroreparative novel stroke therapy with a broad therapeutic window.

Integrin α5ß1 inhibition by ATN-161 reduces neuroinflammation and is neuroprotective in ischemic stroke.

Stroke remains a leading cause of death and disability with limited therapeutic options. Endothelial cell ß1 integrin receptors play a direct role in blood-brain barrier (BBB) dysfunction through regulation of tight junction proteins and infiltrating leukocytes, potentially mediated by ß1 integrins. Following tandem transient common carotid artery/middle cerebral artery occlusion on wild-type mice, we administered the integrin a5b1 inhibitor, ATN-161, intraperitoneal (IP) injection at 1 mg/kg acutely after reperfusion, on post-stroke day (PSD)1 and PSD2. Systemic changes (heart rate, pulse distension, and body temperature) were determined. Additionally, infarct volume and edema were determined by 2,3-triphenyltetrazolium chloride and magnetic resonance imaging, while neurological changes were evaluated using an 11-point Neuroscore. Brain immunohistochemistry was performed for claudin-5, α5ß1, IgG, and CD45 + cells, and quantitative polymerase chain reaction (qPCR) was performed for matrix metalloproteinase-9 (MMP-9), interleukin (IL)-1ß, collagen IV, and CXCL12. ATN-161 significantly reduced integrin α5ß1 expression in the surrounding peri-infarct region with no systemic changes. Infarct volume, edema, and functional deficit were significantly reduced in ATN-161-treated mice. Furthermore, ATN-161 treatment reduced IgG extravasation into the parenchyma through conserved claudin-5, collagen IV, CXCL12 while reducing MMP-9 transcription. Additionally, IL-1ß and CD45 + cells were reduced in the ipsilateral cortex following ATN-161 administration. Collectively, ATN-161 may be a promising novel stroke therapy by reducing post-stroke inflammation and BBB permeability.

Interleukin 1 alpha administration is neuroprotective and neuro-restorative following experimental ischemic stroke.

BACKGROUND: Stroke remains a leading cause of death and disability worldwide despite recent treatment breakthroughs. A primary event in stroke pathogenesis is the development of a potent and deleterious local and peripheral inflammatory response regulated by the pro-inflammatory cytokine interleukin-1 (IL-1). While the role of IL-1ß (main released isoform) has been well studied in stroke, the role of the IL-1α isoform remains largely unknown. With increasing utilization of intravenous tissue plasminogen activator (t-PA) or thrombectomy to pharmacologically or mechanically remove ischemic stroke causing blood clots, respectively, there is interest in pairing successful cerebrovascular recanalization with neurotherapeutic pharmacological interventions (Fraser et al., J Cereb Blood Flow Metab 37:3531-3543, 2017; Hill et al., Lancet Neurol 11:942-950, 2012; Amaro et al., Stroke 47:2874-2876, 2016). METHODS: Transient stroke was induced in mice via one of two methods. One group of mice were subjected to tandem ipsilateral common carotid artery and middle cerebral artery occlusion, while another group underwent the filament-based middle cerebral artery occlusion. We have recently developed an animal model of intra-arterial (IA) drug administration after recanalization (Maniskas et al., J Neurosci Met 240:22-27, 2015). Sub groups of the mice were treated with either saline or Il-1α, wherein the drug was administered either acutely (immediately after surgery) or subacutely (on the third day after stroke). This was followed by behavioral and histological analyses. RESULTS: We now show in the above-mentioned mouse stroke models (transient tandem ipsilateral common carotid artery (CCA) and middle cerebral artery occlusion (MCA) occlusion, MCA suture occlusion) that IL-1α is neuroprotective when acutely given either intravenously (IV) or IA at low sub-pathologic doses. Furthermore, while IV administration induces transient hemodynamic side effects without affecting systemic markers of inflammation, IA delivery further improves overall outcomes while eliminating these side effects. Additionally, we show that delayed/subacute IV IL-1α administration ameliorates functional deficit and promotes neurorepair. CONCLUSIONS: Taken together, our present study suggests for the first time that IL-1α could, unexpectedly, be an effective ischemic stroke therapy with a broad therapeutic window.

The Inflammatory Response After Ischemic Stroke: Targeting ß2 and ß1 Integrins.

Ischemic stroke is a leading cause of death and disability with limited therapeutic options. Resulting inflammatory mechanisms after reperfusion (removal of the thrombus) result in cytokine activation, calcium influx, and leukocytic infiltration to the area of ischemia. In particular, leukocytes migrate toward areas of inflammation by use of integrins, particularly integrins ß1 and ß2. Integrins have been shown to be necessary for leukocyte adhesion and migration, and thus are of immediate interest in many inflammatory diseases, including ischemic stroke. In this review, we identify the main integrins involved in leukocytic migration following stroke (α L ß2, αDß2, α4ß1, and α5ß1) and targeted clinical therapeutic interventions.

Roles of blood-brain barrier integrins and extracellular matrix in stroke.

Ischemicstroke is a leading cause of death and disability in the United States, but recent advances in treatments [i.e., endovascular thrombectomy and tissue plasminogen activator (t-PA)] that target the stroke-causing blood clot, while improving overall stroke mortality rates, have had much less of an impact on overall stroke morbidity. This may in part be attributed to the lack of therapeutics targeting reperfusion-induced injury after the blood clot has been removed, which, if left unchecked, can expand injury from its core into the surrounding at risk tissue (penumbra). This occurs in two phases of increased permeability of the blood-brain barrier, a physical barrier that under physiologic conditions regulates brain influx and efflux of substances and consists of tight junction forming endothelial cells (and transporter proteins), astrocytes, pericytes, extracellular matrix, and their integrin cellular receptors. During, embryonic development, maturity, and following stroke reperfusion, cerebral vasculature undergoes significant changes including changes in expression of integrins and degradation of surrounding extracellular matrix. Integrins, heterodimers with α and ß subunits, and their extracellular matrix ligands, a collection of proteoglycans, glycoproteins, and collagens, have been modestly studied in the context of stroke compared with other diseases (e.g., cancer). In this review, we describe the effect that various integrins and extracellular matrix components have in embryonic brain development, and how this changes in both maturity and in the poststroke environment. Particular focus will be on how these changes in integrins and the extracellular matrix affect blood-brain barrier components and their potential as diagnostic and therapeutic targets for ischemic stroke.

The Blood And Clot Thrombectomy Registry And Collaboration (BACTRAC) protocol: novel method for evaluating human stroke.

BACKGROUND: Ischemic stroke research faces difficulties in translating pathology between animal models and human patients to develop treatments. Mechanical thrombectomy, for the first time, offers a momentary window into the changes occurring in ischemia. We developed a tissue banking protocol to capture intracranial thrombi and the blood immediately proximal and distal to it. OBJECTIVE: To develop and share a reproducible protocol to bank these specimens for future analysis. METHODS: We established a protocol approved by the institutional review board for tissue processing during thrombectomy (www.clinicaltrials.gov NCT03153683). The protocol was a joint clinical/basic science effort among multiple laboratories and the NeuroInterventional Radiology service line. We constructed a workspace in the angiography suite, and developed a step-by-step process for specimen retrieval and processing. RESULTS: Our protocol successfully yielded samples for analysis in all but one case. In our preliminary dataset, the process produced adequate amounts of tissue from distal blood, proximal blood, and thrombi for gene expression and proteomics analyses. We describe the tissue banking protocol, and highlight training protocols and mechanics of on-call research staffing. In addition, preliminary integrity analyses demonstrated high-quality yields for RNA and protein. CONCLUSIONS: We have developed a novel tissue banking protocol using mechanical thrombectomy to capture thrombus along with arterial blood proximal and distal to it. The protocol provides high-quality specimens, facilitating analysis of the initial molecular response to ischemic stroke in the human condition for the first time. This approach will permit reverse translation to animal models for treatment development.

Real-time observation of the solid-liquid-vapor dissolution of individual tin(IV) oxide nanowires.

The well-known vapor-liquid-solid (VLS) mechanism results in high-purity, single-crystalline wires with few defects and controllable diameters, and is the method of choice for the growth of nanowires for a vast array of nanoelectronic devices. It is of utmost importance, therefore, to understand how such wires interact with metallic interconnects-an understanding which relies on comprehensive knowledge of the initial growth process, in which a crystalline wire is ejected from a metallic particle. Though ubiquitous, even in the case of single elemental nanowires the VLS mechanism is complicated by competing processes at multiple heterogeneous interfaces, and despite decades of study, there are still aspects of the mechanism which are not well understood. Recent breakthroughs in studying the mechanism and kinetics of VLS growth have been strongly aided by the use of in situ techniques, and would have been impossible through other means. As well as several systematic studies of nanowire growth, reports which focus on the role and the nature of the catalyst tip reveal that the stability of the droplet is a crucial factor in determining nanowire morphology and crystallinity. Additionally, a reverse of the VLS process dubbed solid-liquid-vapor (SLV) has been found to result in the formation of cavities, or "negative nanowires". Here, we present a series of heating studies conducted in situ in the transmission electron microscope (TEM), in which we observe the complete dissolution of metal oxide nanowires into the metal catalyst particles at their tips. We are able to consistently explain our observations using a solid-liquid-vapor (SLV) type mechanism in which both evaporation at the liquid-vapor interface and adhesion of the catalyst droplet to the substrate surface contribute to the overall rate.