Giant cell tumor of bone in the pediatric population: a retrospective study highlighting cases of metaphyseal only location and increased local recurrence rates in skeletally immature patients.

OBJECTIVE: To describe the presentation of giant cell tumors (GCT) of the bone in the pediatric population to (1) improve the differential diagnosis of pediatric bone tumors and (2) identify the origin of GCT. Understanding the origin of bone tumors assists in establishing appropriate diagnoses and recommending treatment options. This is particularly important in children, where evaluating the need for invasive procedures is balanced with the desire to avoid overtreatment. GCT have historically been considered epiphyseal lesions with potential metaphyseal extension. Therefore, GCT may be inappropriately excluded from the differential diagnosis of metaphyseal lesions in the skeletally immature. MATERIALS AND METHODS: We identified 14 patients from 1981 to 2021 at a single institution who had histologic confirmation of GCT and were less than 18 years old at diagnosis. Patient characteristics, tumor location, surgical treatment, and local recurrence rates were collected. RESULTS AND CONCLUSIONS: Ten (71%) patients were female. Eleven (78.6%) were epiphysiometaphyseal (1 epiphyseal, 4 metaphyseal, 6 epiphysiometaphyseal). Five patients had an open adjacent physis, of which three (60%) had tumors confined solely to the metaphysis. Of the five patients with open physis, four (80%) developed local recurrence while only one patient (11%) with a closed physis had local recurrence (p value = 0.0023). Our results illustrate that for the skeletally immature, GCT can (and in our results more commonly did) occur in the metaphyseal location. These findings suggest that GCT should be included in the differential diagnosis of primary metaphyseal-only lesions in the skeletally immature.

Prescribing costs of hypoglycaemic agents and associations with metabolic control in Wales; a national analysis of primary care data.

AIMS: There has been a dramatic increase in hypoglycaemic agent expenditure. We assessed the variability in prescribing costs at the practice level and the relationship between expenditure and the proportion of patients achieving target glycaemic control. METHODS: We utilized national prescribing data from 406 general practices in Wales. This was compared against glycaemic control (percentage of patients achieving a HbA1c level < 59 mmol/mol in the preceding 12 months). Analyses were adjusted for the number of patients with diabetes in each general practice and the Welsh Index of Multiple Deprivation. RESULTS: There was considerable heterogeneity in hypoglycaemic agent spend per patient with diabetes, Median = £289 (IQR 247-343) range £31.1-£1713. Higher total expenditure was not associated with improved glycaemic control B(std)  = -0.01 (95%CI -0.01, 0.002) p = 0.13. High-spend practices spent more on SGLT2 inhibitors (16 vs. 9% p < 0.001) and GLP-1 agonists (13 vs. 11% p < 0.001) and less on insulin (34 vs. 42% p < 0.001), biguanides (9 vs. 11% p = 0.001) and sulphonylureas (2 vs. 3% p < 0.001) than low spend practices. There were no differences in the pattern of drug prescribing between high spend practices with better glycaemic control (mean 68% of patients HbA1c <59 mmol/mol) and those with less good metabolic control (mean 58% of patients HbA1c <59 mmol/mol). CONCLUSIONS: Spend on hypoglycaemic agents is highly variable between practices and increased expenditure per patient is not associated with better glycaemic control. Whilst newer, more expensive agents have additional benefits, in individuals where these advantages are more marginal widespread use of these agents has important cost implications.

Conotoxin κM-RIIIJ, a tool targeting asymmetric heteromeric Kv1 channels.

The vast complexity of native heteromeric K+ channels is largely unexplored. Defining the composition and subunit arrangement of individual subunits in native heteromeric K+ channels and establishing their physiological roles is experimentally challenging. Here we systematically explored this "zone of ignorance" in molecular neuroscience. Venom components, such as peptide toxins, appear to have evolved to modulate physiologically relevant targets by discriminating among closely related native ion channel complexes. We provide proof-of-principle for this assertion by demonstrating that κM-conotoxin RIIIJ (κM-RIIIJ) from Conus radiatus precisely targets "asymmetric" Kv channels composed of three Kv1.2 subunits and one Kv1.1 or Kv1.6 subunit with 100-fold higher apparent affinity compared with homomeric Kv1.2 channels. Our study shows that dorsal root ganglion (DRG) neurons contain at least two major functional Kv1.2 channel complexes: a heteromer, for which κM-RIIIJ has high affinity, and a putative Kv1.2 homomer, toward which κM-RIIIJ is less potent. This conclusion was reached by (i) covalent linkage of members of the mammalian Shaker-related Kv1 family to Kv1.2 and systematic assessment of the potency of κM-RIIIJ block of heteromeric K+ channel-mediated currents in heterologous expression systems; (ii) molecular dynamics simulations of asymmetric Kv1 channels providing insights into the molecular basis of κM-RIIIJ selectivity and potency toward its targets; and (iii) evaluation of calcium responses of a defined population of DRG neurons to κM-RIIIJ. Our study demonstrates that bioactive molecules present in venoms provide essential pharmacological tools that systematically target specific heteromeric Kv channel complexes that operate in native tissues.

Staging and Surveillance of Myxoid Liposarcoma: Follow-up Assessment and the Metastatic Pattern of 169 Patients Suggests Inadequacy of Current Practice Standards.

BACKGROUND: Unlike other sarcoma subtypes, myxoid liposarcoma (MLS) has a propensity for extra-pulmonary metastases. Computed tomography (CT) scan of the chest, abdomen, and pelvis has become an accepted practice for surveillance. However, recent literature suggests that this may be inadequate. This study aimed to assess the ability of current imaging methods to detect metastases adequately in this population. METHODS: The study identified 169 patients with MLS diagnosed between 2000 and 2016. The timing and location of metastases, the reasons leading to the MLS diagnosis, and the imaging methods were recorded. The locations of metastases were classified into the following categories: pulmonary, soft tissue, bone, retroperitoneal, intraperitoneal, solid organ, and lymph node. RESULTS: An initial diagnosis of metastasis was made at presentation with staging CT scan for 3 (10 %) of 31 patients, with a follow-up surveillance CT scan for 15 (48 %) of the patients or with subsequent imaging obtained in response to patient-reported symptoms for 13 (42 %) of the patients. The proportions of patients who had metastases in each location were as follows: soft tissue (84 %), pulmonary (68 %), intraabdominal (48 %), solid organ (48 %), bone (45 %), lymph node (32 %), and retroperitoneal (29 %). Although 14 patients had bone metastases, only 1 patient had a sclerotic/blastic presentation visualized on CT scan, and the diagnosis for the remaining 13 patients was determined by magnetic resonance imaging (MRI). CONCLUSION: Due to metastatic disease identified outside surveillance imaging for 58 % of the patients, the diversity of locations, and the significant failure of CT and bone scan to identify bone metastases, this study questioned the adequacy of CT scan for surveillance of MLS. Consideration should be given to the use of whole-body MRI for detection of metastasis in MLS.

Humeral intramedullary nail placement through the rotator interval: an anatomic and radiographic analysis.

BACKGROUND: Antegrade humeral intramedullary nails are an effective fixation method for certain proximal humeral fractures and humeral shaft fractures. However, owing to potential rotator cuff damage during nail insertion, shoulder pain remains a common postoperative complaint. The purpose of this study was to provide quantitative data characterizing the anatomic and radiographic location of the rotator interval (RI) for an antegrade humeral intramedullary nail using a mini-deltopectoral approach. METHODS: Six consecutive fresh-frozen intact cadaveric specimens (mean age, 69 ± 12.8 years) were obtained for our study. Demographic data were collected on each specimen. A mini-deltopectoral approach was used, followed by placement of a guidewire in the RI. Quantitative anatomic relationships were calculated using a fractional carbon fiber digital caliper. Radiographic measurements were performed by 2 orthopedic residents and 1 practicing fellowship-trained orthopedic surgeon. In addition to re-measurement of similar anatomic relationships on radiographs, the ratio of the distance from the lateral humeral edge to the starting point relative to the width of the humeral head on the anteroposterior (AP) view was calculated. Similarly, on the lateral view, the ratio of the distance from the anterior humeral edge to the starting point relative to the humeral head width was calculated. RESULTS: In all cases, the described approach allowed for preservation of the biceps tendon and access to the RI for guidewire insertion, with no subsequent rotator cuff or humeral articular cartilage damage identified following nail insertion. The ratio of the distance from the lateral humeral edge to the starting point relative to the humeral head width on the AP view was 0.4 ± 0.0. The ratio of the distance from the anterior humeral edge to the starting point relative to the humeral head width on the lateral view was 0.3 ± 0.0. CONCLUSION: This study demonstrates the clinical feasibility of a mini-deltopectoral approach and shows that the ideal starting point through the RI radiographically lies along the medial aspect of the lateral third of the humeral head on the AP view and along the posterior aspect of the anterior third of the humeral head on the lateral view.

Pregnancy in teenagers diagnosed with type 1 diabetes mellitus in childhood: a national population-based e-cohort study.

AIMS/HYPOTHESIS: The aim of this study was to describe the characteristics and outcomes of pregnancies in a national cohort of teenage (<20 years) and young adult women (≥20 years) with and without childhood-onset (<15 years) type 1 diabetes. We hypothesised that, owing to poor glycaemic control during the teenage years, pregnancy outcomes would be poorer in teenage mothers with type 1 diabetes than young adult mothers with type 1 diabetes and mothers without diabetes. METHODS: The Brecon Register of childhood-onset type 1 diabetes diagnosed in Wales since 1995 was linked to population-based datasets in the Secure Anonymised Information Linkage (SAIL) Databank, creating an electronic cohort (e-cohort) of legal births (live or stillbirths beyond 24 weeks' gestation) to women aged less than 35 years between 1995 and 2013 in Wales. Teenage pregnancy rates were calculated based on the number of females in the same birth cohort in Wales. Pregnancy outcomes, including pre-eclampsia, preterm birth, low birthweight, macrosomia, congenital malformations, stillbirths and hospital admissions during the first year of life, were obtained from electronic records for the whole Welsh population. We used logistic and negative binomial regression to compare outcomes among teenage and young adult mothers with and without type 1 diabetes. RESULTS: A total of 197,796 births were eligible for inclusion, including 330 to girls and women with childhood-onset type 1 diabetes, of whom 68 were teenagers (age 14-19 years, mean 17.9 years) and 262 were young adults (age 20-32 years, mean 24.0 years). The mean duration of diabetes was 14.3 years (9.7 years for teenagers; 15.5 years for young adults). Pregnancy rates were lower in teenagers with type 1 diabetes than in teenagers without diabetes (mean annual teenage pregnancy rate between 1999 and 2013: 8.6 vs 18.0 per 1000 teenage girls, respectively; p < 0.001). In the background population, teenage pregnancy was associated with deprivation (p < 0.001), but this was not the case for individuals with type 1 diabetes (p = 0.85). Glycaemic control was poor in teenage and young adult mothers with type 1 diabetes (mean HbA1c based on closest value to conception: 81.3 and 80.2 mmol/mol [9.6% and 9.5%], respectively, p = 0.78). Glycaemic control improved during pregnancy in both groups but to a greater degree in young adults, who had significantly better glycaemic control than teenagers by the third trimester (mean HbA1c: 54.0 vs 67.4 mmol/mol [7.1% vs 8.3%], p = 0.01). All adverse outcomes were more common among mothers with type 1 diabetes than mothers without diabetes. Among those with type 1 diabetes, hospital admissions during the first year of life were more common among babies of teenage vs young adult mothers (adjusted OR 5.91 [95% CI 2.63, 13.25]). Other outcomes were no worse among teenage mothers with type 1 diabetes than among young adult mothers with diabetes. CONCLUSIONS/INTERPRETATION: Teenage girls with childhood-onset type 1 diabetes in Wales are less likely to have children than teenage girls without diabetes. Teenage pregnancy in girls with type 1 diabetes, unlike in the background population, is not associated with social deprivation. In our cohort, glycaemic control was poor in both teenage and young adult mothers with type 1 diabetes. Pregnancy outcomes were comparable between teenage and young adult mothers with type 1 diabetes, but hospital admissions during the first year of life were five times more common among babies of teenage mothers with type 1 diabetes than those of young adult mothers with diabetes.

Mapping of voltage sensor positions in resting and inactivated mammalian sodium channels by LRET.

Voltage-gated sodium channels (Navs) play crucial roles in excitable cells. Although vertebrate Nav function has been extensively studied, the detailed structural basis for voltage-dependent gating mechanisms remain obscure. We have assessed the structural changes of the Nav voltage sensor domain using lanthanide-based resonance energy transfer (LRET) between the rat skeletal muscle voltage-gated sodium channel (Nav1.4) and fluorescently labeled Nav1.4-targeting toxins. We generated donor constructs with genetically encoded lanthanide-binding tags (LBTs) inserted at the extracellular end of the S4 segment of each domain (with a single LBT per construct). Three different Bodipy-labeled, Nav1.4-targeting toxins were synthesized as acceptors: ß-scorpion toxin (Ts1)-Bodipy, KIIIA-Bodipy, and GIIIA-Bodipy analogs. Functional Nav-LBT channels expressed in Xenopus oocytes were voltage-clamped, and distinct LRET signals were obtained in the resting and slow inactivated states. Intramolecular distances computed from the LRET signals define a geometrical map of Nav1.4 with the bound toxins, and reveal voltage-dependent structural changes related to channel gating.

Extremely Potent Block of Bacterial Voltage-Gated Sodium Channels by µ-Conotoxin PIIIA.

µ-Conotoxin PIIIA, in the sub-picomolar, range inhibits the archetypal bacterial sodium channel NaChBac (NavBh) in a voltage- and use-dependent manner. Peptide µ-conotoxins were first recognized as potent components of the venoms of fish-hunting cone snails that selectively inhibit voltage-gated skeletal muscle sodium channels, thus preventing muscle contraction. Intriguingly, computer simulations predicted that PIIIA binds to prokaryotic channel NavAb with much higher affinity than to fish (and other vertebrates) skeletal muscle sodium channel (Nav 1.4). Here, using whole-cell voltage clamp, we demonstrate that PIIIA inhibits NavBac mediated currents even more potently than predicted. From concentration-response data, with [PIIIA] varying more than 6 orders of magnitude (10-12 to 10-5 M), we estimated an IC50 = ~5 pM, maximal block of 0.95 and a Hill coefficient of 0.81 for the inhibition of peak currents. Inhibition was stronger at depolarized holding potentials and was modulated by the frequency and duration of the stimulation pulses. An important feature of the PIIIA action was acceleration of macroscopic inactivation. Docking of PIIIA in a NaChBac (NavBh) model revealed two interconvertible binding modes. In one mode, PIIIA sterically and electrostatically blocks the permeation pathway. In a second mode, apparent stabilization of the inactivated state was achieved by PIIIA binding between P2 helices and trans-membrane S5s from adjacent channel subunits, partially occluding the outer pore. Together, our experimental and computational results suggest that, besides blocking the channel-mediated currents by directly occluding the conducting pathway, PIIIA may also change the relative populations of conducting (activated) and non-conducting (inactivated) states.

NCCN Guidelines as a Model of Extended Criteria for Lung Cancer Screening.

Background: This review assessed the performance of patients in NCCN high-risk group 2 in a clinical CT lung screening (CTLS) program. Methods: We retrospectively reviewed screening results for all patients from our institution undergoing clinical CTLS from January 2012 through December 2016, with follow-up through June 2017. To qualify for screening, patients had to meet the NCCN Guidelines high-risk criteria for CTLS, have a physician order for screening, be asymptomatic, be lung cancer-free for 5 years, and have no known metastatic disease. We compared demographics and screening performance of NCCN high-risk groups 1 and 2 across >4 rounds of screening. Screening metrics assessed included rates of positive and suspicious examinations, significant incidental and infectious/inflammatory findings, false negatives, and cancer detection. We also compared cancer stage and histology detected in each NCCN high-risk group. Results: A total of 2,927 individuals underwent baseline screening, of which 698 (24%) were in NCCN group 2. On average, group 2 patients were younger (60.6 vs 63.1 years), smoked less (38.8 vs 50.8 pack-years), had quit longer (18.1 vs 6.3 years), and were more often former smokers (61.4% vs 44.2%). Positive and suspicious examination rates, false negatives, and rates of infectious/inflammatory findings were equivalent in groups 1 and 2 across all rounds of screening. An increased rate of cancer detection was observed in group 2 during the second annual (T2) screening round (2.7% vs 0.5%; P=.005), with no difference in the other screening rounds: baseline (T0; 2% vs 2.3%; P=.61), first annual (T1; 1.2% vs 1.7%; P=.41), and third annual and beyond (≥T3; 1.2% vs 1.1%; P=1.00). Conclusions: CTLS appears to be equally effective in both NCCN high-risk groups.

Embodiment and the origin of interval timing: kinematic and electromyographic data.

Recent evidence suggests that interval timing (the judgment of durations lasting from approximately 500 ms. to a few minutes) is closely coupled to the action control system. We used surface electromyography (EMG) and motion capture technology to explore the emergence of this coupling in 4-, 6-, and 8-month-olds. We engaged infants in an active and socially relevant arm-raising task with seven cycles and response period. In one condition, cycles were slow (every 4 s); in another, they were fast (every 2 s). In the slow condition, we found evidence of time-locked sub-threshold EMG activity even in the absence of any observed overt motor responses at all three ages. This study shows that EMGs can be a more sensitive measure of interval timing in early development than overt behavior.

Across space and time: infants learn from backward and forward visual statistics.

This study investigates whether infants are sensitive to backward and forward transitional probabilities within temporal and spatial visual streams. Two groups of 8-month-old infants were familiarized with an artificial grammar of shapes, comprising backward and forward base pairs (i.e. two shapes linked by strong backward or forward transitional probability) and part-pairs (i.e. two shapes with weak transitional probabilities in both directions). One group viewed the continuous visual stream as a temporal sequence, while the other group viewed the same stream as a spatial array. Following familiarization, infants looked longer at test trials containing part-pairs than base pairs, although they had appeared with equal frequency during familiarization. This pattern of looking time was evident for both forward and backward pairs, in both the temporal and spatial conditions. Further, differences in looking time to part-pairs that were consistent or inconsistent with the predictive direction of the base pairs (forward or backward) indicated that infants were indeed sensitive to direction when presented with temporal sequences, but not when presented with spatial arrays. These results suggest that visual statistical learning is flexible in infancy and depends on the nature of visual input.

Local anesthetic and antiepileptic drug access and binding to a bacterial voltage-gated sodium channel.

Voltage-gated sodium (Nav) channels are important targets in the treatment of a range of pathologies. Bacterial channels, for which crystal structures have been solved, exhibit modulation by local anesthetic and anti-epileptic agents, allowing molecular-level investigations into sodium channel-drug interactions. These structures reveal no basis for the "hinged lid"-based fast inactivation, seen in eukaryotic Nav channels. Thus, they enable examination of potential mechanisms of use- or state-dependent drug action based on activation gating, or slower pore-based inactivation processes. Multimicrosecond simulations of NavAb reveal high-affinity binding of benzocaine to F203 that is a surrogate for FS6, conserved in helix S6 of Domain IV of mammalian sodium channels, as well as low-affinity sites suggested to stabilize different states of the channel. Phenytoin exhibits a different binding distribution owing to preferential interactions at the membrane and water-protein interfaces. Two drug-access pathways into the pore are observed: via lateral fenestrations connecting to the membrane lipid phase, as well as via an aqueous pathway through the intracellular activation gate, despite being closed. These observations provide insight into drug modulation that will guide further developments of Nav inhibitors.

An evaluation of scanpath-comparison and machine-learning classification algorithms used to study the dynamics of analogy making.

In recent years, eyetracking has begun to be used to study the dynamics of analogy making. Numerous scanpath-comparison algorithms and machine-learning techniques are available that can be applied to the raw eyetracking data. We show how scanpath-comparison algorithms, combined with multidimensional scaling and a classification algorithm, can be used to resolve an outstanding question in analogy making-namely, whether or not children's and adults' strategies in solving analogy problems are different. (They are.) We show which of these scanpath-comparison algorithms is best suited to the kinds of analogy problems that have formed the basis of much analogy-making research over the years. Furthermore, we use machine-learning classification algorithms to examine the item-to-item saccade vectors making up these scanpaths. We show which of these algorithms best predicts, from very early on in a trial, on the basis of the frequency of various item-to-item saccades, whether a child or an adult is doing the problem. This type of analysis can also be used to predict, on the basis of the item-to-item saccade dynamics in the first third of a trial, whether or not a problem will be solved correctly.

Gating transitions in the selectivity filter region of a sodium channel are coupled to the domain IV voltage sensor.

Voltage-dependent ion channels are crucial for generation and propagation of electrical activity in biological systems. The primary mechanism for voltage transduction in these proteins involves the movement of a voltage-sensing domain (D), which opens a gate located on the cytoplasmic side. A distinct conformational change in the selectivity filter near the extracellular side has been implicated in slow inactivation gating, which is important for spike frequency adaptation in neural circuits. However, it remains an open question whether gating transitions in the selectivity filter region are also actuated by voltage sensors. Here, we examine conformational coupling between each of the four voltage sensors and the outer pore of a eukaryotic voltage-dependent sodium channel. The voltage sensors of these sodium channels are not structurally symmetric and exhibit functional specialization. To track the conformational rearrangements of individual voltage-sensing domains, we recorded domain-specific gating pore currents. Our data show that, of the four voltage sensors, only the domain IV voltage sensor is coupled to the conformation of the selectivity filter region of the sodium channel. Trapping the outer pore in a particular conformation with a high-affinity toxin or disulphide crossbridge impedes the return of this voltage sensor to its resting conformation. Our findings directly establish that, in addition to the canonical electromechanical coupling between voltage sensor and inner pore gates of a sodium channel, gating transitions in the selectivity filter region are also coupled to the movement of a voltage sensor. Furthermore, our results also imply that the voltage sensor of domain IV is unique in this linkage and in the ability to initiate slow inactivation in sodium channels.

Epidemiology of the reported severity of cottonmouth (Agkistrodon piscivorus) snakebite.

OBJECTIVE: The goal of this study was to analyze trends in the annual rates of reported medical outcomes of cottonmouth (Agkistrodon piscivorus) snakebites in the United States, published in the annual reports of the American Association of Poison Control Centers in the course of 29 years. METHODS: This was a retrospective analysis of medical outcomes for cottonmouth snakebite victims who developed fatal, major, moderate, minor, or no effects. The annual rates for these medical outcomes were calculated by dividing the annual number of patients in each outcome category by the total annual number of people reported as being bitten by cottonmouths. Negative binomial regression was used to examine trends in annual rates. RESULTS: From 1985 through 2011, after controlling for the availability of CroFab, the annual incidence rate of cottonmouth snakebites causing no effect decreased significantly by 7.3%/year (incidence rate ratio [IRR] 0.927, 95% confidence interval [CI] 0.885-0.970), the incidence rate of minor outcomes did not change significantly (IRR 0.989, CI 0.974-1.006), the incidence rate of moderate outcomes increased significantly by 2.3%/year (IRR 1.023, CI 1.004-1.042), and the incidence rate of major outcomes did not change significantly (IRR 0.987, CI 0.935-1.041). One fatality was reported in 2011. CONCLUSIONS: Annual rates of cottonmouth snakebites producing no effects decreased significantly, those producing minor outcomes did not change significantly, those producing moderate outcomes increased significantly, and those producing major outcomes did not change significantly, from 1985 through 2011.

Novel radiology PRIMER course enhances medical student perception of radiology and key concept comprehension.

RATIONALE AND OBJECTIVES: A novel three-day radiology course, PRIMER, directly preceding medical students' clinical year, was created and assessed. The required course consisted of large group lecture sessions, small group breakout sessions, and individual assignments. Though early exposure to radiology has been described in preclinical anatomy curricula, few schools offer immersive experiences to radiology as a direct predecessor to the wards. MATERIALS AND METHODS: An identical survey was distributed prior to and at the completion of the PRIMER course. Students' perceptions of radiology were assessed through Likert-style questions. Students' knowledge of radiological concepts was assessed through multiple choice questions (MCQs) related to key concepts, MCQs in which students selected the most likely diagnosis, and hotspot questions in which learners had to select the area of greatest clinical importance. Mean pre- and post-course student perception scores were compared using a T-test. For knowledge-based questions, each student received an exam score, and mean pre- and post-exam scores were compared using a T-test. RESULTS: Students' opinions of radiology changed significantly in a favorable direction across all tested questions between inception and conclusion of PRIMER (p < 0.01). Students demonstrated superior knowledge of radiological concepts after course completion (posttest mean 52% vs pretest mean 26.3%, p < 0.01). CONCLUSION: The novel radiology PRIMER course promoted a positive impression of radiology and increased medical students' knowledge of key concepts. These results suggest that a condensed introductory radiology curriculum delivered at a key moment in the overarching curriculum can have a significant impact on medical students' perceptions and knowledge.

Near-Peer Paradigms in Medical School: Integrating Student Teaching Assistants Into a Core Radiology Clerkship.

RATIONALE AND OBJECTIVES: Near-peer paradigms have been demonstrated effective in supporting how students navigate novel clinical environments. In this study, we describe an innovative model of incorporating teaching assistants (TAs) into a core radiology clerkship and investigate both its perceived educational value by clinical-year learners and its perceived impact on professional growth by TAs. MATERIALS AND METHODS: At one U.S. medical school, the core clinical year includes a clerkship in radiology incorporating both reading room exposure and a didactic curriculum. Radiology faculty deliver a variety of traditional and interactive, "dynamic" lectures, while medical student TAs deliver additional dynamic sessions, including a final TA-created review session. The educational value of each didactic session by clerkship students was assessed using a five-point scale survey, and the professional value of the experience by TAs was assessed using a five-point Likert survey. RESULTS: Spanning from 2020 to 2023, 268 (74.4%) clinical-year students submitted the post-clerkship survey, with the didactic review sessions created and led by TAs receiving the highest ratings of any didactic session. Of 16 former TAs, 12 (75%) completed the post-service survey, with all respondents agreeing or strongly agreeing that they enjoyed and would recommend their experience, and that it enhanced their interest in radiology and in academic medicine. CONCLUSION: Near-peer education in a core radiology clerkship enhances the experience of the learner through peer guidance and the experience of the teacher through professional development. These findings may increase student interest in pursuing academic radiology as a career and invite opportunities for broadening medical school education in radiology.

Medical student perspectives on radiology subspecialties prior to core clerkship.

RATIONALE AND OBJECTIVES: Radiology remains underrepresented in U.S. medical school clinical curricula, and preconceived opinions about the field may impact whether students pursue elective exposure. A core radiology clerkship at one academic institution presents an opportunity to evaluate students' early preferences for different radiology subspecialties, thus informing curricular design and inspiring student recruitment. MATERIALS AND METHODS: At a single allopathic medical school, a required, four-week, clinical-year radiology clerkship that occurs in the second year includes immersive one-week experiences in two subspecialties. Prior to their clerkship, students rank their immersion preferences by distributing 100 points across eight fields, the values of which were analyzed as a proxy for interest. A secondary survey was distributed to active first- and second-year medical students to further investigate the factors drawing them to radiology. RESULTS: Immersive experiences in musculoskeletal, body, and breast imaging were most preferred, earning ≥20 points from 41.6 %, 34.3 %, and 31.9 % of students, respectively. Women were significantly more likely than men to express interest in breast imaging (35.8 % vs. 24.8 %, p = 0.037) and pediatric radiology (28.8 % vs. 12.8 %, p = 0.001). Men were significantly more likely than women to prefer body imaging (41.9 % vs. 30.2 %, p = 0.034), neuroradiology (29.1 % vs. 19.5 %, p = 0.048), and nuclear medicine (11.1 % vs. 5.1 %, p = 0.044). CONCLUSION: Early in their clinical education, medical students prefer certain subspecialties, especially musculoskeletal, body, and breast imaging. Women expressed significantly stronger interest in breast imaging and pediatric radiology, while men indicated significantly stronger interest in body imaging, neuroradiology, and nuclear medicine.

Comparison of Low-Dose Computed Tomography Versus Conventional-Dose Computed Tomography in the Evaluation of Distal Radius Fractures.

BACKGROUND: Distal radius fractures (DRFs) are common upper extremity fractures and often require surgical fixation when they are intraarticular. Preoperative computed tomography (CT) has emerged as a surgical planning tool to evaluate intraarticular DRFs. Although CT affords additional details, patients receive higher radiation doses than standard radiographs. We aim to develop a low-dose CT (LDCT) protocol, relative to the institutional standard-dose CT wrist for intraarticular DRFs although providing adequate detail for surgical decision-making. METHODS: A single-institution prospective study was conducted on patients with intraarticular DRFs who underwent closed reduction and below-elbow splinting who otherwise would undergo wrist CT. Observations were defined as total measurements taken, with each view undergoing 44 measurements. Patients underwent 2 scans with a standard dose and a 10× dose reduction. Articular step and gap measurements were recorded in the sagittal and coronal images. RESULTS: A total of 11 patients were enrolled (7 women and 4 men). The mean age was 55 years (SD = 20.1). There were a total of 4 reviewers: 1 attending surgeon, 2 resident physicians, and 1 student. When comparing LDCT and conventional-dose CT (CDCT), there were no significant differences in step and gap measurements across all reviewers. CONCLUSION: This study demonstrated that LDCT provides comparable imaging quality for surgical planning as a CDCT without significant diagnostic decay in the setting of DRFs. This comes with the added benefit of a 10-fold reduction in radiation exposure. These results suggest that LDCT is an opportunity to reduce effective radiation in patients although providing beneficial preoperative imaging.

AAV gene therapy in companion dogs with severe hemophilia: Real-world long-term data on immunogenicity, efficacy, and quality of life.

The hemophilias are the most common severe inherited bleeding disorders and are caused by deficiency of clotting factor (F) VIII (hemophilia A) or FIX (hemophilia B). The resultant bleeding predisposition significantly increases morbidity and mortality. The ability to improve the bleeding phenotype with modest increases in clotting factor levels has enabled the development and regulatory approval of adeno-associated viral (AAV) vector gene therapies for people with hemophilia A and B. The canine hemophilia model has proven to be one of the best predictors of therapeutic response in humans. Here, we report long-term follow-up of 12 companion dogs with severe hemophilia that were treated in a real-world setting with AAV gene therapy. Despite more baseline bleeding than in research dogs, companion dogs demonstrated a 94% decrease in bleeding rates and 61% improvement in quality of life over a median of 4.1 years (range 2.6-8.9). No new anti-transgene immune responses were detected; one dog with a pre-existing anti-FVIII inhibitor achieved immune tolerance with gene therapy. Two dogs expressing 1%-5% FVIII post gene therapy experienced fatal bleeding events. These data suggest AAV liver-directed gene therapy is efficacious in a real-world setting but should target expression >5% and closely monitor those with levels in the 1%-5% range.