Follicular lymphoma evolves with a surmountable dependency on acquired glycosylation motifs in the B-cell receptor.

ABSTRACT: An early event in the genesis of follicular lymphoma (FL) is the acquisition of new glycosylation motifs in the B-cell receptor (BCR) due to gene rearrangement and/or somatic hypermutation. These N-linked glycosylation motifs (N-motifs) contain mannose-terminated glycans and can interact with lectins in the tumor microenvironment, activating the tumor BCR pathway. N-motifs are stable during FL evolution, suggesting that FL tumor cells are dependent on them for their survival. Here, we investigated the dynamics and potential impact of N-motif prevalence in FL at the single-cell level across distinct tumor sites and over time in 17 patients. Although most patients had acquired at least 1 N-motif as an early event, we also found (1) cases without N-motifs in the heavy or light chains at any tumor site or time point and (2) cases with discordant N-motif patterns across different tumor sites. Inferring phylogenetic trees of the patients with discordant patterns, we observed that both N-motif-positive and N-motif-negative tumor subclones could be selected and expanded during tumor evolution. Comparing N-motif-positive with N-motif-negative tumor cells within a patient revealed higher expression of genes involved in the BCR pathway and inflammatory response, whereas tumor cells without N-motifs had higher activity of pathways involved in energy metabolism. In conclusion, although acquired N-motifs likely support FL pathogenesis through antigen-independent BCR signaling in most patients with FL, N-motif-negative tumor cells can also be selected and expanded and may depend more heavily on altered metabolism for competitive survival.

Single-cell analysis can define distinct evolution of tumor sites in follicular lymphoma.

Tumor heterogeneity complicates biomarker development and fosters drug resistance in solid malignancies. In lymphoma, our knowledge of site-to-site heterogeneity and its clinical implications is still limited. Here, we profiled 2 nodal, synchronously acquired tumor samples from 10 patients with follicular lymphoma (FL) using single-cell RNA, B-cell receptor (BCR) and T-cell receptor sequencing, and flow cytometry. By following the rapidly mutating tumor immunoglobulin genes, we discovered that BCR subclones were shared between the 2 tumor sites in some patients, but in many patients, the disease had evolved separately with limited tumor cell migration between the sites. Patients exhibiting divergent BCR evolution also exhibited divergent tumor gene-expression and cell-surface protein profiles. While the overall composition of the tumor microenvironment did not differ significantly between sites, we did detect a specific correlation between site-to-site tumor heterogeneity and T follicular helper (Tfh) cell abundance. We further observed enrichment of particular ligand-receptor pairs between tumor and Tfh cells, including CD40 and CD40LG, and a significant correlation between tumor CD40 expression and Tfh proliferation. Our study may explain discordant responses to systemic therapies, underscores the difficulty of capturing a patient's disease with a single biopsy, and furthers our understanding of tumor-immune networks in FL.

First report of Pseudocerradoa paullula causing aroid leaf rust on Swiss cheese plant Monstera deliciosa in South Carolina, USA.

In February 2023, two Monstera deliciosa Liebm. (Araceae) plants with typical symptoms of leaf rust disease were detected at a grocery store in Oconee Co., South Carolina. Symptoms included chlorotic leaf spots and abundant brownish uredinia, mainly on the adaxial surface of more than 50% of leaves. The same disease was detected on 11 out of 481 M. deliciosa plants in a greenhouse at a plant nursery located in York Co., South Carolina, in March 2023. The first plant sample detected in February was used for morphological characterization, molecular identification, and pathogenicity confirmation of the rust fungus. Urediniospores were densely aggregated, globose, golden to golden brown in color, and measured 22.9 to 27.9 µm (aver. 26.0 ± 1.1 µm; n=50) in diameter with wall thickness at 1.3 to 2.6 µm (aver. 1.8 ± 0.3 µm; n=50). Telia were not observed. These morphological traits aligned with those of Pseudocerradoa paullula (basionym: Puccinia paullula; Ebinghaus et al. 2022; Sakamoto et al. 2023; Sydow and Sydow 1913; Urbina et al. 2023). Genomic DNA was extracted from urediniospores collected from the naturally infected plant sample and used for PCR amplification and DNA sequencing of the large subunit (LSU) genetic marker with primers LRust1R and LR3 (Vilgalys and Hester 1990; Beenken et al. 2012). The LSU sequence of the rust fungus in South Carolina (GenBank accession: OQ746460) is 99.9% identical to that of Ps. paullula voucher BPI 893085 (763/764 nt.; KY764151), 99.4% identical to that of voucher PIGH 17154 in Florida, USA (760/765 nt.; OQ275201), and 99% identical to that of voucher TNS-F-82075 in Japan (715/722 nt.; OK509071). Based on its morphological and molecular characteristics, the causal agent was identified as Ps. paullula. This pathogen identification was also corroborated by the U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Plant Pathogen Confirmatory Diagnostics Laboratory in Laurel, Maryland. To confirm the fungus's pathogenicity on M. deliciosa and M. adansonii Schott (Sakamoto et al. 2023), three plants of each Monstera species were inoculated by spraying with a suspension of urediniospores collected from the original plant sample (1 × 106 spores per ml; approx. 40 ml per plant). Three non-inoculated control plants of each host species were treated with deionized water in the same manner. Plants were placed in a plastic tray with wet paper towels to maintain moisture. The tray was placed at 22C for an 8-h photoperiod and covered for five days to facilitate infection. On 25 days after inoculation, abundant spots bearing urediniospores were produced on all leaves of inoculated M. deliciosa plants. A few uredinia were observed on two of the three inoculated M. adansonii plants. All non-inoculated control plants remained asymptomatic. Morphological features of urediniospores collected from inoculated plants matched those of Ps. paullula used as the inoculum. Aroid leaf rust on Monstera plants was officially reported in Australia, China, Japan, Malaysia, Philippines, and Florida, USA (Shaw 1991; Sakamoto et al. 2023; Urbina et al. 2023). This is the first report of Ps. paullula causing this disease on M. deliciosa in South Carolina, USA. Monstera species are popular indoor and landscape plants. Potential impact and regulatory responses regarding Ps. paullula, a newly introduced and rapidly spreading pathogen in the USA, warrant further evaluation and discussion.

Surgical Skill Can be Objectively Measured From Fluoroscopic Images Using a Novel Image-based Decision Error Analysis (IDEA) Score.

BACKGROUND: To advance orthopaedic surgical skills training and assessment, more rigorous and objective performance measures are needed. In hip fracture repair, the tip-apex distance is a commonly used summative performance metric with clear clinical relevance, but it does not capture the skill exercised during the process of achieving the final implant position. This study introduces and evaluates a novel Image-based Decision Error Analysis (IDEA) score that better captures performance during fluoroscopically-assisted wire navigation. QUESTIONS/PURPOSES: (1) Can wire navigation skill be objectively measured from a sequence of fluoroscopic images? (2) Are skill behaviors observed in a simulated environment also exhibited in the operating room? Additionally, we sought to define an objective skill metric that demonstrates improvement associated with accumulated surgical experience. METHODS: Performance was evaluated both on a hip fracture wire navigation simulator and in the operating room during actual fracture surgery. After examining fluoroscopic image sequences from 176 consecutive simulator trials (performed by 58 first-year orthopaedic residents) and 21 consecutive surgical procedures (performed by 19 different orthopaedic residents and one attending orthopaedic surgeon), three main categories of erroneous skill behavior were identified: off-target wire adjustments, out-of-plane wire adjustments, and off-target drilling. Skill behaviors were measured by comparing wire adjustments made between consecutive images against the goal of targeting the apex of the femoral head as part of our new IDEA scoring methodology. Decision error metrics (frequency, magnitude) were correlated with other measures (image count and tip-apex distance) to characterize factors related to surgical performance on both the simulator and in the operating room. An IDEA composite score integrating decision errors (off-target wire adjustments, out-of-plane wire adjustments, and off-target drilling) and the final tip-apex distance to produce a single metric of overall performance was created and compared with the number of hip wire navigation cases previously completed (such as surgeon experience levels). RESULTS: The IDEA methodology objectively analyzed 37,000 images from the simulator and 688 images from the operating room. The number of decision errors (7 ± 5 in the operating room and 4 ± 3 on the simulator) correlated with fluoroscopic image count (33 ± 14 in the operating room and 20 ± 11 on the simulator) in both the simulator and operating room environments (R2 = 0.76; p < 0.001 and R2 = 0.71; p < 0.001, respectively). Decision error counts did not correlate with the tip-apex distance (16 ± 4 mm in the operating room and 12 ± 5 mm on the simulator) for either the simulator or the operating room (R2 = 0.08; p = 0.15 and R2 = 0.03; p = 0.47, respectively), indicating that the tip-apex distance is independent of decision errors. The IDEA composite score correlated with surgical experience (R2 = 0.66; p < 0.001). CONCLUSION: The fluoroscopic images obtained in the course of placing a guide wire contain a rich amount of information related to surgical skill. This points the way to an objective measure of skill that also has potential as an educational tool for residents. Future studies should expand this analysis to the wide variety of procedures that rely on fluoroscopic images. CLINICAL RELEVANCE: This study has shown how resident skill development can be objectively assessed from fluoroscopic image sequences. The IDEA scoring provides a basis for evaluating the competence of a resident. The score can be used to assess skill at key timepoints throughout residency, such as when rotating onto/off of a new surgical service and before performing certain procedures in the operating room, or as a tool for debriefing/providing feedback after a procedure is completed.

Restricted versus liberal intraoperative benzodiazepine use in cardiac anaesthesia for reducing delirium (B-Free Pilot): a pilot, multicentre, randomised, cluster crossover trial.

BACKGROUND: Delirium is common after cardiac surgery and is associated with adverse outcomes. Perioperative benzodiazepine use is associated with delirium and is common during cardiac surgery, which may increase the risk of postoperative delirium. We undertook a pilot study to inform the feasibility of a large randomised cluster crossover trial examining whether an institutional policy of restricted benzodiazepine administration during cardiac surgery (compared with liberal administration) would reduce delirium. METHODS: We conducted a two-centre, pilot, randomised cluster crossover trial with four 4 week crossover periods. Each centre was randomised to a policy of restricted or liberal use, and then alternated between the two policies during the remaining three periods. Our feasibility outcomes were adherence to each policy (goal ≥80%) and outcome assessment (one delirium assessment per day in the ICU in ≥90% of participants). We also evaluated the incidence of intraoperative awareness in one site using serial Brice questionnaires. RESULTS: Of 800 patients undergoing cardiac surgery during the trial period, 127/800 (15.9%) had delirium. Of these, 355/389 (91.3%) received benzodiazepines during the liberal benzodiazepine periods and 363/411 (88.3%) did not receive benzodiazepines during the restricted benzodiazepine periods. Amongst the 800 patients, 740 (92.5%) had ≥1 postoperative delirium assessment per day in the ICU. Of 521 patients screened for intraoperative awareness, one patient (0.2%), managed during the restricted benzodiazepine period (but who received benzodiazepine), experienced intraoperative awareness. CONCLUSIONS: This pilot study demonstrates the feasibility of a large, multicentre, randomised, cluster crossover trial examining whether an institutional policy of restricted vs liberal benzodiazepine use during cardiac surgery will reduce postoperative delirium. CLINICAL TRIAL REGISTRATION: NCT03053869.

Combined Effects of Confinement and Macromolecular Crowding on Protein Stability.

Confinement and crowding have been shown to affect protein fates, including folding, functional stability, and their interactions with self and other proteins. Using both theoretical and experimental studies, researchers have established the independent effects of confinement or crowding, but only a few studies have explored their effects in combination; therefore, their combined impact on protein fates is still relatively unknown. Here, we investigated the combined effects of confinement and crowding on protein stability using the pores of agarose hydrogels as a confining agent and the biopolymer, dextran, as a crowding agent. The addition of dextran further stabilized the enzymes encapsulated in agarose; moreover, the observed increases in enhancements (due to the addition of dextran) exceeded the sum of the individual enhancements due to confinement and crowding. These results suggest that even though confinement and crowding may behave differently in how they influence protein fates, these conditions may be combined to provide synergistic benefits for protein stabilization. In summary, our study demonstrated the successful use of polymer-based platforms to advance our understanding of how in vivo like environments impact protein function and structure.

Do Skills Acquired from Training with a Wire Navigation Simulator Transfer to a Mock Operating Room Environment?

BACKGROUND: Skills training and simulation play an increasingly important role in orthopaedic surgical education. The intent of simulation is to improve performance in the operating room (OR), a trait known as transfer validity. No prior studies have explored how simulator-based wire navigation training can transfer to higher-level tasks. Additionally, there is a lack of knowledge on the format in which wire navigation training should be deployed. QUESTIONS/PURPOSES: (1) Which training methods (didactic content, deliberate practice, or proficiency-based practice) lead to the greatest improvement in performing a wire navigation task? (2) Does a resident's performance using a wire navigation simulator correlate with his or her performance on a higher-level simulation task in a mock OR involving a C-arm, a radiopaque femur model, and a large soft tissue surrogate surrounding the femur? METHODS: Fifty-five residents from four different medical centers participated in this study over the course of 2 years. The residents were divided into three groups: traditional training (included first-year residents from the University of Iowa, University of Minnesota, and the Mayo Clinic), deliberate practice (included first-year residents from the University of Nebraska and the University of Minnesota), and proficiency training (included first-year residents from the University of Minnesota and the Mayo Clinic). Residents in each group received a didactic introduction covering the task of placing a wire to treat an intertrochanteric fracture, and this was considered traditional training. Deliberate practice involved training on a radiation-free simulator that provided specific feedback throughout the practice sessions. Proficiency training used the same simulator to train on specific components of wire navigation, like finding the correct starting point, to proficiency before moving to assessment. The wire navigation simulator uses a camera system to track the wire and provide computer-generated fluoroscopy. After training, task performance was assessed in a mock OR. Residents from each group were assessed in the mock OR based on their use of fluoroscopy, total time, and tip-apex distance. Correlation analysis was performed to examine the relationship between resident performance on the simulator and in the mock OR. RESULTS: Residents in the two simulation-based training groups had a lower tip-apex distance than those in the traditional training group (didactic training tip-apex distance: 24 ± 7 mm, 95% CI, 20-27; deliberate practice tip-apex distance: 16 ± 5 mm, 95% CI, 13-19, p = 0.001; proficiency training tip-apex distance: 15 ± 4 mm, 95% CI, 13-18, p < 0.001). Residents in the proficiency training group used more images than those in the other groups (didactic training: 22 ± 12 images, p = 0.041; deliberate practice: 19 ± 8 images; p = 0.012, proficiency training: 31 ± 14 images). In the two simulation-based training groups, resident performance on the simulator, that is, tip-apex distance, image use, and overall time, was correlated with performance in the mock OR (r-square = 0.15 [p = 0.030], 0.61 [p < 0.001], and 0.43 [p < 0.001], respectively). CONCLUSIONS: As residency programs are designing their curriculum to train wire navigation skills, emphasis should be placed on providing an environment that allows for deliberate practice with immediate feedback about their performance. Simulators such as the one presented in this study offer a safe environment for residents to learn this key skill. LEVEL OF EVIDENCE: Level II, therapeutic study.

Tranexamic Acid Administration During On-Pump Cardiac Surgery: A Survey of Current Practices Among Canadian Anesthetists Working in Academic Centers.

BACKGROUND: Tranexamic acid (TXA) is commonly administered during on-pump cardiac surgery to minimize bleeding. However, an optimal dosing regimen has not been described, and recent studies suggest that higher doses may be associated with seizure. Little is known about current practice among cardiac anesthetists. METHODS: We contacted all academic anesthesia departments in Canada to identify cardiac anesthetists, who represent the majority of practitioners. This group constituted our sampling frame. Information regarding participant demographics, TXA dose, and administration details were obtained by electronic survey. Responses were analyzed descriptively. To compare dose, we assumed an 80-kg patient and 3 hours of infusion time. The Kruskal-Wallis test was used to compare average dose across provinces. RESULTS: Among 341 Canadian academic cardiac anesthetists, 234 completed the survey (68.2% response rate). Among respondents, 86.3% administer TXA to all patients; 13.7% administer it to some. Most (68.4%) administer an infusion after a bolus; other modes included infusion (4.7%), single bolus (13.2%), 2 or more boluses (12.0%), or another regimen (1.7%). The mean (standard deviation) dose given was 49 mg/kg (24), with a range from 10 to 100 mg/kg. The mean dose varied across provinces from 23 to 55 mg/kg (P = .001). CONCLUSIONS: TXA is given to nearly all patients undergoing on-pump cardiac surgery at academic hospitals in Canada. However, there is significant heterogeneity in practice between individuals and across provinces. Further research is needed to determine the TXA dose that maximizes efficacy and minimizes side effects.

Predictors of intraoperative testing in adults undergoing noncardiac surgery within a regional hospital system.

BACKGROUND: The use of intraoperative testing is central to anesthesia practice, and point-of-care testing (POCT) is often used. Nevertheless, POCT is costly and its contribution to patient outcome is unknown. There is a lack of guidelines to describe which patients should undergo intraoperative testing or how results should be applied. As such, we undertook a historical cohort study evaluating intraoperative testing practices within our region where POCT is not used. METHODS: In 2012, we obtained a random sample of 1,000 adult patients undergoing noncardiac surgery in three of our health system hospitals. Patient, surgical, and testing details were extracted, and the surgical procedures were categorized using the Johns Hopkins risk guidelines. Our primary outcome was the administration of at least one intraoperative test. We used a multivariable logistic regression model to identify factors associated with testing and described the time from ordering the tests to receiving the results using descriptive statistics. RESULTS: Study results showed that 110/1,000 (11.0%) patients underwent 413 diagnostic tests. Complete blood count was the most commonly administered test (36.3%), and the mean (standard deviation) time to obtain all test results was 29.9 (19.9) min. High-risk procedures were associated with an odds ratio (OR) of 12.3 (95% confidence interval [CI], 8.3 to 18.2; P < 0.001). Other predictors of intraoperative testing included emergency surgery (OR, 3.8; 95% CI, 2.0 to 7.2; P < 0.001), number of comorbidities (OR, 1.1; 95% CI, 1.0 to 1.2; P = 0.03), and duration of surgery (OR, 2.3; 95% CI, 1.8 to 2.9; P < 0.001). CONCLUSION: Intraoperative testing is common and more likely in patients undergoing high-risk surgical procedures. In a central laboratory system, there is substantial time from ordering the tests to receiving the results. The clinical impact of this delay is unknown. Further evaluation is required regarding the relationship between the time required for intraoperative test results and perioperative outcomes.

On Holo-Hilbert spectral analysis: a full informational spectral representation for nonlinear and non-stationary data.

The Holo-Hilbert spectral analysis (HHSA) method is introduced to cure the deficiencies of traditional spectral analysis and to give a full informational representation of nonlinear and non-stationary data. It uses a nested empirical mode decomposition and Hilbert-Huang transform (HHT) approach to identify intrinsic amplitude and frequency modulations often present in nonlinear systems. Comparisons are first made with traditional spectrum analysis, which usually achieved its results through convolutional integral transforms based on additive expansions of an a priori determined basis, mostly under linear and stationary assumptions. Thus, for non-stationary processes, the best one could do historically was to use the time-frequency representations, in which the amplitude (or energy density) variation is still represented in terms of time. For nonlinear processes, the data can have both amplitude and frequency modulations (intra-mode and inter-mode) generated by two different mechanisms: linear additive or nonlinear multiplicative processes. As all existing spectral analysis methods are based on additive expansions, either a priori or adaptive, none of them could possibly represent the multiplicative processes. While the earlier adaptive HHT spectral analysis approach could accommodate the intra-wave nonlinearity quite remarkably, it remained that any inter-wave nonlinear multiplicative mechanisms that include cross-scale coupling and phase-lock modulations were left untreated. To resolve the multiplicative processes issue, additional dimensions in the spectrum result are needed to account for the variations in both the amplitude and frequency modulations simultaneously. HHSA accommodates all the processes: additive and multiplicative, intra-mode and inter-mode, stationary and non-stationary, linear and nonlinear interactions. The Holo prefix in HHSA denotes a multiple dimensional representation with both additive and multiplicative capabilities.

Objective Structured Assessments of Technical Skills (OSATS) Does Not Assess the Quality of the Surgical Result Effectively.

BACKGROUND: Performance assessment in skills training is ideally based on objective, reliable, and clinically relevant indicators of success. The Objective Structured Assessment of Technical Skill (OSATS) is a reliable and valid tool that has been increasingly used in orthopaedic skills training. It uses a global rating approach to structure expert evaluation of technical skills with the experts working from a list of operative competencies that are each rated on a 5-point Likert scale anchored by behavioral descriptors. Given the observational nature of its scoring, the OSATS might not effectively assess the quality of surgical results. QUESTIONS/PURPOSES: (1) Does OSATS scoring in an intraarticular fracture reduction training exercise correlate with the quality of the reduction? (2) Does OSATS scoring in a cadaveric extraarticular fracture fixation exercise correlate with the mechanical integrity of the fixation? METHODS: Orthopaedic residents at the University of Iowa (six postgraduate year [PGY]-1s) and at the University of Minnesota (seven PGY-1s and eight PGY-2s) undertook a skills training exercise that involved reducing a simulated intraarticular fracture under fluoroscopic guidance. Iowa residents participated three times during 1 month, and Minnesota residents participated twice with 1 month between their two sessions. A fellowship-trained orthopaedic traumatologist rated each performance using a modified OSATS scoring scheme. The quality of the articular reduction obtained was then directly measured. Regression analysis was performed between OSATS scores and two metrics of articular reduction quality: articular surface deviation and estimated contact stress. Another skills training exercise involved fixing a simulated distal radius fracture in a cadaveric specimen. Thirty residents, distributed across four PGY classes (PGY-2 and PGY-3, n = 8 each; PGY-4 and PGY-5, n = 7 each), simultaneously completed the exercise at individual stations. One of three faculty hand surgeons independently scored each performance using a validated OSATS scoring system. The mechanical integrity of each fixation construct was then assessed in a materials testing machine. Regression analysis was performed between OSATS scores and two metrics of fixation integrity: stiffness and failure load. RESULTS: In the intraarticular fracture model, OSATS scores did not correlate with articular reduction quality (maximum surface deviations: R = 0.17, p = 0.25; maximum contact stress: R = 0.22, p = 0.13). Similarly in the cadaveric extraarticular fracture model, OSATS scores did not correlate with the integrity of the mechanical fixation (stiffness: R = 0.10, p = 0.60; failure load: R = 0.30, p = 0.10). CONCLUSIONS: OSATS scoring methods do not effectively assess the quality of the surgical result. Efforts must be made to incorporate assessment metrics that reflect the quality of the surgical result. CLINICAL RELEVANCE: New objective, reliable, and clinically relevant measures of the quality of the surgical result obtained by a trainee are urgently needed. For intraarticular fracture reduction and extraarticular fracture fixation, direct physical measurement of reduction quality and of mechanical integrity of fixation, respectively, meet this need.

Temporal uncoupling of the DNA methylome and transcriptional repression during embryogenesis.

DNA methylation is a tightly regulated epigenetic mark associated with transcriptional repression. Next-generation sequencing of purified methylated DNA obtained from early Xenopus tropicalis embryos demonstrates that this genome is heavily methylated during blastula and gastrula stages. Although DNA methylation is largely absent from transcriptional start sites marked with histone H3 lysine 4 trimethylation (H3K4me3), we find both promoters and gene bodies of active genes robustly methylated. In contrast, DNA methylation is absent in large H3K27me3 domains, indicating that these two repression pathways have different roles. Comparison with chromatin state maps of human ES cells reveals strong conservation of epigenetic makeup and gene regulation between the two systems. Strikingly, genes that are highly expressed in pluripotent cells and in Xenopus embryos but not in differentiated cells exhibit relatively high DNA methylation. Therefore, we tested the repressive potential of DNA methylation using transient and transgenic approaches and show that methylated promoters are robustly transcribed in blastula- and gastrula-stage embryos, but not in oocytes or late embryos. These findings have implications for reprogramming and the epigenetic regulation of pluripotency and differentiation and suggest a relatively open, pliable chromatin state in early embryos followed by reestablished methylation-dependent transcriptional repression during organogenesis and differentiation.

Primary Melanoma of the Urinary Bladder: Clinical, Histopathologic, and Comprehensive Molecular Analysis of a Rare Tumor.

Primary melanoma of the urinary bladder is extremely rare and generally has a poor prognosis. The histopathological diagnosis can be challenging as tumors can be unpigmented and of varying morphology. Here we report a rare example of primary urinary bladder melanoma with clinical, imaging, gross anatomical, histopathologic, immunohistochemical, and molecular findings to illustrate the utility of an integrated approach in establishing the diagnosis and guide therapy. A comprehensive, integrated approach, including molecular studies, may be helpful in further establishing an accurate diagnosis and informing therapies of this rare but poorly behaved entity.

A Surgical Skills Rotation for Mid-Level Residents.

Introduction: The University of Iowa orthopaedic residency previously designed a month-long surgical skill rotation for postgraduate year (PGY)-1 residents. This successful initiative has become a model of interest for other teaching institutions. In addition to the intern year, an important phase in residency occurs during the transition from PGY2 to PGY3, when residents assume greater responsibility and autonomy in leading surgical procedures. Methods: To directly address this transition and assess residents' readiness, our residency program established a week-long PGY2 surgical skills rotation. This rotation serves as a training checkpoint and focuses on both training and evaluation of level-appropriate skills in joint arthroplasty, trauma, arthroscopy, and wire navigation. The primary objective of the PGY2 surgical skills rotation is to enhance orthopaedic residents' operative skills and experience by providing increased exposure and practice of requisite technical skills. Similar to the Orthopedic In-Training Examinations that assess residents' knowledge, this week-long program, aimed at assessing residents' proficiency in fundamental orthopaedic technical skills, occurs before their PGY3 year. Results: Faculty-led training and assessment sessions in each area offer residents many opportunities for dedicated practice and improvement. Transferring these acquired skills from the laboratory to the operating room is essential for a training program. To confirm improvement, the final day of the surgical skills rotation was exclusively dedicated to structured performance evaluations, with a specific emphasis on establishing proficiency benchmarks. Conclusion: We herein describe the University of Iowa's PGY2 surgical skills rotation, providing insights into its development, implementation, and outcomes. By sharing our experience, we offer a framework for other academic departments seeking to optimize surgical skills education and ensure the successful transition of mid-level residents.

Fluoroscopic image-based behavior analysis can objectively explain subjective expert assessment of wire navigation skill.

Psychomotor skill and decision-making efficiency in surgical wire navigation can be objectively evaluated by analysis of intraoperative fluoroscopic image sequences. Prior work suggests that such image-based behavior analysis of operating room (OR) performance can predict performer experience level (R2 = 0.62) and agree with expert opinion (the current standard) on the quality of a final implant construct (R2 = 0.59). However, it is unclear how objective image-based evaluation compares with expert assessments for entire technical OR performances. This study examines the relationships between three key variables: (1) objective image-based criteria, (2) expert opinions, and (3) performing surgeon experience level. A paired-comparison survey of seven experts, based upon eight OR fluoroscopic wire navigation image sequences, shows that the experts' preferences are best explained by objective metrics that reflect psychomotor and decision-making behaviors which are counter-productive to successful implant placement, like image count (R2 = 0.83) and behavior tally (R2 = 0.74). One such behavior, adjustments away from goal, uniquely correlated well with all three key variables: a fluoroscopic image-based analysis composite score (R2 = 0.40), expert consensus (R2 = 0.76), and performer experience (R2 = 0.41). These results confirm that experts view less efficient technical behavior as indicative of lesser technical proficiency. While expert assessments of technical skill were reliable and consistent, neither individual nor consensus expert opinion appears to correlate with performer experience (R2 = 0.11).

CYLD Alterations Are Associated With Metastasis and Poor Prognosis in Human Papilloma Virus-Positive Head and Neck Cancer.

BACKGROUND: Human papilloma virus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) is an emerging epidemic and a subset of HPV-positive patients experience aggressive disease with metastases. The CYLD gene is frequently altered in HPV-positive HNSCC, but the role of these alterations in disease progression is poorly understood. METHODS: We identified 11 HPV-positive HNSCC patients with CYLD alterations and assessed their clinical course. We also characterized a unique, HPV-positive, metastatic, HNSCC patient-derived xenograft (PDX). RESULTS: All 11 patients developed metastasis with reduced overall survival when compared with metastatic HPV-positive patients with wild-type CYLD. The metastatic PDX harbored a CYLD mutation (S371*) and exhibited reduced expression of connexin 43, a potentially antimetastatic protein. We also investigated the functional impact of the S371* mutation, as well as 2 CYLD mutations from our 11-patient cohort. CONCLUSION: Our findings indicate that alterations in CYLD in HPV-positive HNSCC are associated with metastasis and poor prognosis.

Codelivery of TGFß and Cox2 siRNA inhibits HCC by promoting T-cell penetration into the tumor and improves response to Immune Checkpoint Inhibitors.

Upregulation of TGFß and Cox2 in the tumor microenvironment results in blockade of T-cell penetration into the tumor. Without access to tumor antigens, the T-cell response will not benefit from administration of the immune checkpoint antibodies. We created an intravenous polypeptide nanoparticle that can deliver two siRNAs (silencing TGFß and Cox2). Systemic administration in mice, bearing a syngeneic orthotopic hepatocellular carcinoma (HCC), delivers the siRNAs to various cells in the liver, and significantly reduces the tumor. At 2 mg/kg (BIW) the nanoparticle demonstrated a single agent action and induced tumor growth inhibition to undetectable levels after five doses. Reducing the siRNAs to 1mg/kg BIW demonstrated greater inhibition in the presence of PD-L1 mAbs. After only three doses BIW, we could still recover a smaller tumor and, in tumor sections, showed an increase in penetration of CD4+ and CD8+ T-cells deeper into the remaining tumor that was not evident in animals treated with non-silencing siRNA. The combination of TGFß and Cox2 siRNA co-administered in a polypeptide nanoparticle can act as a novel therapeutic alone against HCC and may augment the activity of the immune checkpoint antibodies. Silencing TGFß and Cox2 converts an immune excluded (cold) tumor into a T-cell inflamed (hot) tumor.