Inhibiting IL-2 signaling and the regulatory T-cell pathway using computationally designed peptides.

Background Increased serum levels of soluble interleukin-2 (IL-2) receptor alpha (sIL-2Rα) are an indicator of poor prognosis in patients with B-cell non-Hodgkin lymphoma (NHL). By binding to IL-2, sIL-2Rα upregulates Foxp3 expression and induces the development of regulatory T (Treg) cells. Methods To inhibit the binding of IL-2 to sIL-2Rα with the goal of suppressing the induction of Foxp3 and decreasing Treg cell numbers, we developed peptides by structure-based computational design to disrupt the interaction between IL-2 and sIL-2Rα. Each peptide was screened using an enzyme-linked immunosorbent assay (ELISA), and 10 of 22 peptides showed variable capacity to inhibit IL-2/sIL-2Rα binding. Results We identified a lead candidate peptide, CMD178, which consistently reduced the expression of Foxp3 and STAT5 induced by IL-2/sIL-2Rα signaling. Furthermore, production of cytokines (IL-2/interferon gamma [IFN-γ]) and granules (perforin/granzyme B) was preserved in CD8+ T cells co-cultured with IL-2-stimulated CD4+ T cells that had been pretreated with CMD178 compared to CD8+ cells co-cultured with untreated IL-2-stimulated CD4+ T cells where it was inhibited. Conclusions We conclude that structure-based peptide design can be used to identify novel peptide inhibitors that block IL-2/sIL-2Rα signaling and inhibit Treg cell development. We anticipate that these peptides will have therapeutic potential in B-cell NHL and other malignancies.

Rigorous Computational and Experimental Investigations on MDM2/MDMX-Targeted Linear and Macrocyclic Peptides.

There is interest in peptide drug design, especially for targeting intracellular protein-protein interactions. Therefore, the experimental validation of a computational platform for enabling peptide drug design is of interest. Here, we describe our peptide drug design platform (CMDInventus) and demonstrate its use in modeling and predicting the structural and binding aspects of diverse peptides that interact with oncology targets MDM2/MDMX in comparison to both retrospective (pre-prediction) and prospective (post-prediction) data. In the retrospective study, CMDInventus modules (CMDpeptide, CMDboltzmann, CMDescore and CMDyscore) were used to accurately reproduce structural and binding data across multiple MDM2/MDMX data sets. In the prospective study, CMDescore, CMDyscore and CMDboltzmann were used to accurately predict binding affinities for an Ala-scan of the stapled α-helical peptide ATSP-7041. Remarkably, CMDboltzmann was used to accurately predict the results of a novel D-amino acid scan of ATSP-7041. Our investigations rigorously validate CMDInventus and support its utility for enabling peptide drug design.

Identification and initial optimization of inhibitors of Clostridium difficile (C. difficile) toxin B (TcdB).

The discovery, synthesis and preliminary structure-activity relationship (SAR) of a novel class of inhibitors of Clostridium difficile (C. difficile) toxin B (TcdB) is described. A high throughput screening (HTS) campaign resulted in the identification of moderately active screening hits 1-5 the most potent of which was compound 1 (IC50 = 0.77 µM). In silico docking of an early analog offered suggestions for structural modification which resulted in the design and synthesis of highly potent analogs 13j(IC50 = 1 nM) and 13 l(IC50 = 7 nM) which were chosen as leads for further optimization.

A combined cheminformatic and bioinformatic approach to address the proteolytic stability challenge in peptide-based drug discovery.

We have created models to predict cleavage sites for several human proteases including caspase-1, caspase-3, caspase-6, caspase-7, cathepsin B, cathepsin D, cathepsin G, cathepsin K, cathepsin L, elastase-2, granzyme A, granzyme B, matrix metallopeptidase-2 (MMP2), MMP7, MMP9, thrombin, and trypsin-1. Rather than representing the sequence pattern around the potential cleavage site through a series of flags with each flag representing one of the 20 standard amino acids, we first represent each amino acid by its calculated properties. For these calculated properties, we use validated cheminformatic descriptors, such as molecular weight, logP, and polar surface area, of the individual amino acids. Finally, the cleavage site-specific descriptors are calculated through various combinations of the individual amino acid descriptors for the residues surrounding the cleavage site. Some of these combinations do not take into account the location of the residue, as long as it is in a prescribed neighborhood of the potential cleavage site, whereas others are sensitive to the precise order of the residues in the sequence. The key advantage of this approach is that it allows one to perform meaningful calculations with nonstandard amino acids for which little or no data exists. Finally, using both docking and molecular dynamics simulations, we examine the potential for and limitations of protease crystal structures to impact the design of proteolytically stable peptides.

Avalanche for shape and feature-based virtual screening with 3D alignment.

This report introduces a new ligand-based virtual screening tool called Avalanche that incorporates both shape- and feature-based comparison with three-dimensional (3D) alignment between the query molecule and test compounds residing in a chemical database. Avalanche proceeds in two steps. The first step is an extremely rapid shape/feature based comparison which is used to narrow the focus from potentially millions or billions of candidate molecules and conformations to a more manageable number that are then passed to the second step. The second step is a detailed yet still rapid 3D alignment of the remaining candidate conformations to the query conformation. Using the 3D alignment, these remaining candidate conformations are scored, re-ranked and presented to the user as the top hits for further visualization and evaluation. To provide further insight into the method, the results from two prospective virtual screens are presented which show the ability of Avalanche to identify hits from chemical databases that would likely be missed by common substructure-based or fingerprint-based search methods. The Avalanche method is extended to enable patent landscaping, i.e., structural refinements to improve the patentability of hits for deployment in drug discovery campaigns.

VSViewer3D: a tool for interactive data mining of three-dimensional virtual screening data.

The VSviewer3D is a simple Java tool for visual exploration of three-dimensional (3D) virtual screening data. The VSviewer3D brings together the ability to explore numerical data, such as calculated properties and virtual screening scores, structure depiction, interactive topological and 3D similarity searching, and 3D visualization. By doing so the user is better able to quickly identify outliers, assess tractability of large numbers of compounds, visualize hits of interest, annotate hits, and mix and match interesting scaffolds. We demonstrate the utility of the VSviewer3D by describing a use case in a docking based virtual screen.

Decision-Making During Asynchronous Electives: Insights From Emergency Medicine-Bound Medical Students.

Introduction While asynchronous learning is gaining popularity, little is known about learners' decisions regarding compliance with assigned asynchronous material. We sought to explore how medical students make decisions about the use of their time when engaging in asynchronous learning during the residency interview season.  Methods After implementing a four-week blended elective for emergency medicine-bound fourth-year medical students, we conducted a mixed methods study with an explanatory sequential design. We analyzed weekly surveys regarding accountability and barriers to assignment completion and conducted semi-structured focus groups exploring the decisions students made regarding compliance with asynchronous assignments. Using a constructivist approach, we performed a thematic analysis of the transcripts. Results The average assignment completion rate was 36%, with the highest rates for podcasts (58%) and the lowest rates for textbook readings (20%). Compliance with assignments was enhanced by a desire for increased ownership of learning but was hindered by a lack of accountability, learner burnout, and higher prioritization of interviews. Students preferentially selected resources that were shorter in length, entertaining, and more convenient for travel. Conclusion Our study highlights factors impacting student compliance when engaging in asynchronous learning and offers insights into educational and institutional strategies that can be utilized to enhance learner motivation.

Is it worth it? A qualitative analysis of the impact of medical education fellowships on careers.

Objectives: Medical education fellowships provide training in teaching, assessment, educational program administration, and scholarship. The longitudinal impact of this training is unknown. The objective of this study was to explore the impact of medical education fellowships on the careers of graduates. Methods: The authors performed a qualitative study with a constructivist-interpretivist paradigm using semistructured interviews in 2021. The authors used a purposeful randomized stratified sampling strategy of graduates to ensure diversity of representation (gender, region, fellowship duration, and career stage). Two researchers independently analyzed interview transcriptions using a modified grounded theory approach. Results: The authors interviewed 10 graduates and identified three overarching concepts: motivations for pursuing fellowship, benefits of training, and drivers of career development. Graduates sought training because of their desire for growth and career preparation and at the advice of mentors. Fellowships provided knowledge and skills in a structured learning environment, supported by mentors and a collaborative community. Fellowship training shaped the careers of graduates by increasing their self-efficacy, enhancing their outcome expectations, refining their goals, and influencing their professional identity formation. They acquired expertise that prepared them for jobs, developed credibility, felt competitive in the job market, anticipated successful promotion, reached for greater goals, broadened their educational worldview, and evolved their professional identity as a result of fellowship training. Conclusions: Fellowship training in medical education provides knowledge and skills, a structured learning environment, and important relationships that shape the careers of graduates by impacting their self-efficacy, outcome expectations, goal creation, and professional identity formation.

Recent applications of computational methods to allosteric drug discovery.

Interest in exploiting allosteric sites for the development of new therapeutics has grown considerably over the last two decades. The chief driving force behind the interest in allostery for drug discovery stems from the fact that in comparison to orthosteric sites, allosteric sites are less conserved across a protein family, thereby offering greater opportunity for selectivity and ultimately tolerability. While there is significant overlap between structure-based drug design for orthosteric and allosteric sites, allosteric sites offer additional challenges mostly involving the need to better understand protein flexibility and its relationship to protein function. Here we examine the extent to which structure-based drug design is impacting allosteric drug design by highlighting several targets across a variety of target classes.

A workforce study of emergency medicine medical education fellowship directors: Describing roles, responsibilities, support, and priorities.

Introduction: Despite emergency medicine (EM) medical education fellowships increasing in number, the position of the medical education fellowship director (FD) remains incompletely defined. The goal of this study was to characterize the roles, responsibilities, support, and priorities for medical education FDs. Methods: We adapted and piloted an anonymous electronic survey consisting of 31 single-answer, multiple-answer, and free-response items. The survey was distributed to FDs via listserv and individual emails from a directory compiled from multiple online resources. We used descriptive statistics to analyze data from items with discrete answer choices. Using a constructivist paradigm, we performed a thematic analysis of free-response data. Results: Thirty-four medical education FDs completed the survey, resulting in a response rate of 77%. Thirty-eight percent of respondents were female. Fifty-three percent earned master's degrees in education and 35% completed a medical education fellowship. Most respondents held other education leadership roles including program director (28%), associate/assistant program director (28%), and vice chair (25%). Sixty-three percent received support in their role, including clinical buy-down (90%), administrative assistants (55%), and salary (5%). There was no difference (χ2 [2, n = 32] = 1.77, p = 0.41) between availability of support and type of hospital (community, university, or public hospital). Medical education FDs dedicated a median of 12 h per month to fellowship responsibilities, include education (median 35% of time), program administration (25%), research mentorship (15%), and recruitment (10%). Medical education FDs describe priorities that can be categorized into three themes related to fellows, fellowship, and institution. Conclusion: This study provides insight into the current position and experience of medical education FDs. The results can clarify the role and responsibilities of FDs as the demand for medical education FDs increases.

Outcome assessment of medical education fellowships in emergency medicine.

OBJECTIVES: Medical education fellowships in emergency medicine (EM) provide training in teaching, assessment, educational program administration, and scholarship. The longitudinal impact of this training is unknown. Our objective was to characterize the career outcomes of medical education fellowship graduates. METHODS: We solicited curriculum vitae (CV) from graduates of U.S. EM education fellowships by email. We abstracted data from CVs with a standard instrument that included program characteristics, employment history, leadership positions, awards, and scholarly productivity. We calculated and reported descriptive statistics. RESULTS: A total of 71 of 91 (78%) graduates participated. Thirty-three completed a 1-year fellowship and 38 completed a 2-year fellowship. Nineteen (27%) completed an advanced degree during fellowship. Median (range) graduation year was 2016 (1997-2020). The majority, 63 of 71 (89%), work in an academic setting. Graduates held leadership positions in continuing medical education, graduate medical education, and undergraduate medical education. Forty-eight (68%) served on national medical education committees. The mean ± SD number of national medical education awards was 1.27 ± 2.03. The mean ± SD number of national medical education presentations was 7.63 ± 10.83. Graduates authored a mean ± SD of 3.63 ± 5.81 book chapters and a mean ± SD of 4.99 ± 6.17 peer-reviewed medical education research publications. Ten (14%) served on journal editorial boards, 34 (48%) were journal reviewers, and 31 (44%) had received a medical education grant. CONCLUSION: EM medical education fellowship graduates are academically productive and hold education leadership positions.

Does academic practice protect emergency physicians against burnout?

Burnout is a complex syndrome thought to result from long-term exposure to career-related stressors. Physicians are at higher risk for burnout than the general United States (US) working population, and emergency medicine has some of the highest burnout rates of any medical specialty. Burnout impacts physicians' quality of life, but it can also increase medical errors and negatively affect patient safety. Several studies have reported lower burnout rates and higher job satisfaction in academic medicine as compared with private practice. However, researchers have only begun to explore the factors that underlie this protective effect. This paper aims to review existing literature to identify specific aspects of academic practice in emergency medicine that may be associated with lower physician burnout rates and greater career satisfaction. Broadly, it appears that spending time in the area of emergency medicine one finds most meaningful has been associated with reduced physician burnout. Certain non-clinical academic work, including involvement in research, leadership, teaching, and mentorship, have been identified as specific activities that may protect against burnout and contribute to higher job satisfaction. Given the epidemic of physician burnout, hospitals and practice groups have a responsibility to address burnout, both by prevention and by early recognition and support. We discuss methods by which organizations can actively foster physician well-being and provide examples of 2 leading academic institutions that have developed comprehensive programs to promote physician wellness and prevent burnout.

Computational alanine scanning with linear scaling semiempirical quantum mechanical methods.

Alanine scanning is a powerful experimental tool for understanding the key interactions in protein-protein interfaces. Linear scaling semiempirical quantum mechanical calculations are now sufficiently fast and robust to allow meaningful calculations on large systems such as proteins, RNA and DNA. In particular, they have proven useful in understanding protein-ligand interactions. Here we ask the question: can these linear scaling quantum mechanical methods developed for protein-ligand scoring be useful for computational alanine scanning? To answer this question, we assembled 15 protein-protein complexes with available crystal structures and sufficient alanine scanning data. In all, the data set contains Delta Delta Gs for 400 single point alanine mutations of these 15 complexes. We show that with only one adjusted parameter the quantum mechanics-based methods outperform both buried accessible surface area and a potential of mean force and compare favorably to a variety of published empirical methods. Finally, we closely examined the outliers in the data set and discuss some of the challenges that arise from this examination.

Insights for predicting blood-brain barrier penetration of CNS targeted molecules using QSPR approaches.

Due to the high attrition rate of central nervous system drug candidates during clinical trials, the assessment of blood-brain barrier (BBB) penetration in early research is particularly important. A genetic approximation (GA)-based regression model was developed for predicting in vivo blood-brain partitioning data, expressed as logBB (log[brain]/[blood]). The model was built using an in-house data set of 193 compounds assembled from 22 different therapeutic projects. The final model (cross-validated r(2) = 0.72) with five molecular descriptors was selected based on validation using several large internal and external test sets. We demonstrate the potential utility of the model by applying it to a set of literature reported secretase inhibitors. In addition, we describe a rule-based approach for rapid assessment of brain penetration with several simple molecular descriptors.

Management of proximal humeral fractures: surgeons don't agree.

HYPOTHESIS: The management options for proximal humeral fractures have expanded in recent years. Patients with displaced, unstable proximal humeral fractures may have improved outcomes if managed operatively. We investigated the decision making of fellowship-trained orthopedic surgeons when presented with the same group of cases. We hypothesized that interobserver and intraobserver agreement for surgical management would be poor and independent of fellowship training. METHOD: Eight fellowship-trained orthopedic surgeons (3 shoulder, 5 trauma) viewed the preoperative plain radiographs of patients with proximal humeral fractures. All surgeons viewed the same 38 radiographs in a blinded fashion. Surgeons chose from 1 of 6 management options. Interobserver variability was calculated by using the weighted kappa coefficient. Intraobserver variability was calculated by comparing each surgeon's survey results with the operation they originally performed. RESULTS: Overall interobserver agreement on management was moderate (weighted kappa=0.41) and did not differ significantly between trauma surgeons and shoulder surgeons. Reducing the number of management choices increased agreement between all surgeons. Testing for intraobserver agreement showed that surgeons picked the same operation in the survey as in the actual clinical setting only 56% of the time. CONCLUSION: Interobserver agreement was moderate overall and improved when the number of management choices was reduced. Intraobserver agreement was less frequent, however, raising the question about consistent decision making by a given surgeon. Although surgeons agree in the method of treatment only to a modest degree, it remains for further outcomes research to establish if the choice of treatment actually influences the clinical outcome.

2-Benzimidazolyl-9-(chroman-4-yl)-purinone derivatives as JAK3 inhibitors.

A novel class of Janus tyrosine kinase 3 (JAK3) inhibitors based on a 2-benzimidazoylpurinone core structure is described. Through substitution of the benzimidazoyl moiety and optimization of the N-9 substituent of the purinone, compound 24 was identified incorporating a chroman-based functional group. Compound 24 shows excellent kinase activity, good oral bioavailability and demonstrates efficacy in an acute mechanistic mouse model through inhibition of interleukin-2 (IL-2) induced interferon-gamma (INF-gamma) production.

Open versus arthroscopic acromioclavicular joint resection: a retrospective comparison study.

PURPOSE: The purpose was to compare open and arthroscopic acromioclavicular joint (ACJ) resection. METHODS: We retrospectively reviewed 103 patients (105 shoulders) who underwent ACJ resection between 2000 and 2005. There were 56 women and 47 men with a mean age of 48 years. The mean duration of follow-up was 51 months (range, 15 to 91 months). Arthroscopic ACJ resection by use of a direct approach was performed in 81 shoulders (group A), and open ACJ resection was performed in 24 shoulders (group B). Results were graded according to pain relief both subjectively and objectively with cross-body adduction testing and direct palpation of the ACJ, subjective shoulder value, Constant score, and improved function. RESULTS: The Constant scores increased from 50 (range, 34 to 65) to 89 (range, 39 to 100) in group A (P < .0001) and from 46 (range, 22 to 63) to 87 (range, 43 to 100) in group B (P < .0001). There was no statistical difference in the postoperative normalized Constant score between group A and group B (P = .47). Pain with cross-body adduction testing and palpation of the ACJ improved in 76 shoulders (94%) in group A and 22 shoulders (92%) in group B. No patients had signs or symptoms of ACJ anteroposterior instability. Revision ACJ resection was performed in 5 patients (5 shoulders [6.2%]) in group A and 1 shoulder (4.2%) in group B (P = .37). The radiographs of the patients who underwent revision showed that 3 patients (3.7%) from group A had regrowth of the distal clavicle; in addition, 2 patients (2.5%) from group A and 1 patient (4.3%) from group B had incomplete distal clavicle excision. CONCLUSIONS: This study did not show a significant difference in the outcome between arthroscopic and open ACJ resection. Incomplete excision and regrowth of the distal clavicle are the most common causes of revision. Although only the arthroscopic group showed a small percentage of patients (3.7%) with regrowth of the distal clavicle, the number is too small to assume that this complication is the result of the arthroscopic technique only. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Qualitative Analysis of Well-being Preparedness at an Emergency Medicine Residency Program.

INTRODUCTION: There is significant variability in the preparedness of incoming interns at the start of residency training with regard to medical knowledge, procedural skills, and attitudes. Specialty-specific preparatory courses aimed at improving clinical skills exist; however, no preparatory courses targeting wellness promotion or burnout prevention have previously been described. Resident well-being has gained increasing attention from the Accreditation Council for Graduate Medical Education, and numerous studies have demonstrated high levels of burnout among resident physicians. The American Medical Association (AMA) divides resident well-being into the following six categories: nutrition, fitness, emotional health, financial health, preventative care, and mindset and behavioral adaptability. Using the AMA's conceptual framework for well-being in residency, we performed a targeted needs assessment to support the development of a "pre-residency" well-being curriculum. Our aim was to discover what current residents and faculty felt were the perceived areas of under-preparedness, in relation to resident well-being, for incoming interns at the start of their residency training. METHODS: Using a grounded theory approach, we conducted a series of semi-structured, focus group interviews. Focus groups consisted of junior residents (postgraduate years [PGY] 1-3), senior residents (PGY-4), and current faculty members. A standardized interview guide was used to prompt discussion and themes were identified from audio recording. We modified theories based on latent and manifest content analysis, and we performed member checking and an external audit to improve validity. RESULTS: Participants noted variable exposure to both formal and informal well-being training prior to residency. Regardless, participants uniformly agreed that their past experiences did not adequately prepare them for the challenges, specific to burnout prevention, faced during residency training. Of the six domains of resident well-being described by the AMA, emotional health, mindset and behavioral adaptability, and financial health were the domains most cited for interns to be underprepared for at the start of residency training. CONCLUSION: Despite variability in prior medical school and life experiences, incoming interns were underprepared in several domains of well-being, including emotional health, mindset and behavioral adaptability, and financial health. Targeted interventions toward these areas of well-being should be piloted and studied further for their potential to mitigate effects of burnout among resident physicians.

Which Emergency Medicine Milestone Sub-competencies are Identified Through Narrative Assessments?

INTRODUCTION: Evaluators use assessment data to make judgments on resident performance within the Accreditation Council for Graduate Medical Education (ACGME) milestones framework. While workplace-based narrative assessments (WBNA) offer advantages to rating scales, validity evidence for their use in assessing the milestone sub-competencies is lacking. This study aimed to determine the frequency of sub-competencies assessed through WBNAs in an emergency medicine (EM) residency program. METHODS: We performed a retrospective analysis of WBNAs of postgraduate year (PGY) 2-4 residents. A shared mental model was established by reading and discussing the milestones framework, and we created a guide for coding WBNAs to the milestone sub-competencies in an iterative process. Once inter-rater reliability was satisfactory, raters coded each WBNA to the 23 EM milestone sub-competencies. RESULTS: We analyzed 2517 WBNAs. An average of 2.04 sub-competencies were assessed per WBNA. The sub-competencies most frequently identified were multitasking, medical knowledge, practice-based performance improvement, patient-centered communication, and team management. The sub-competencies least frequently identified were pharmacotherapy, airway management, anesthesia and acute pain management, goal-directed focused ultrasound, wound management, and vascular access. Overall, the frequency with which WBNAs assessed individual sub-competencies was low, with 14 of the 23 sub-competencies being assessed in less than 5% of WBNAs. CONCLUSION: WBNAs identify few milestone sub-competencies. Faculty assessed similar sub-competencies related to interpersonal and communication skills, practice-based learning and improvement, and medical knowledge, while neglecting sub-competencies related to patient care and procedural skills. These findings can help shape faculty development programs designed to improve assessments of specific workplace behaviors and provide more robust data for the summative assessment of residents.