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Simple Summary: We explored the potential of using proteins found in extracellular vesicles (EVs), which are tiny particles released by cancer cells, to predict treatment response and identify new drug targets. Unlike traditional tissue biopsies, analyzing EVs from blood samples offers a non-invasive way to obtain valuable information about the cancer. Our findings showed that certain proteins in EVs, such as B7-H3 and LAT1, are correlated with clinical markers such as PSA levels, PET scans, and serum alkaline phosphatase levels that are used to monitor disease burden and cancer progression. This approach could lead to more precise and personalized treatment options for patients with advanced prostate cancer, helping doctors choose the most effective therapies and improve outcomes. Introduction: Prostate cancer treatment has been revolutionized by targeted therapies, including PARP inhibitors, checkpoint immunotherapies, and PSMA-targeted radiotherapies. Despite such advancements, accurate patient stratification remains a challenge, with current methods relying on genomic markers, tissue staining, and imaging. Extracellular vesicle (EV)-derived proteins offer a novel non-invasive alternative for biomarker discovery, holding promise for improving treatment precision. However, the characterization of plasma-derived EVs in prostate cancer patients remains largely unexplored. Methods: We conducted proteomic analyses on EVs isolated from plasma in 27 metastatic castration-resistant prostate cancer (mCRPC) patients. EVs were purified using ultracentrifugation and analyzed via mass spectrometry. Proteomic data were correlated with clinical markers such as serum prostate-specific antigen (PSA) and bone lesion counts. Statistical significance was assessed using Mann–Whitney t-tests and Spearman correlation. Results: The median age of patients was 74 (range: 44–94) years. At the time of blood collection, the median PSA level was 70 (range: 0.5–1000) ng/mL. All patients had bone metastasis. A total of 5213 proteins were detected, including EV-related proteins (CD9, CD81, CD63, FLOT1, TSG101) and cancer-related proteins (PSMA, B7-H3, PD-L1). Proteomic profiling of plasma EVs revealed a significant correlation between specific EV-derived proteins and clinical prognostic markers. B7-H3, LAT1, and SLC29A1 showed a strong association with serum PSA levels and number of bone lesions, indicating potential for these proteins to serve as biomarkers of disease burden and therapy response. Conclusions: Our findings demonstrate the potential of EV-based proteomics for identifying biomarkers in mCRPC patients. Proteins such as B7-H3 and LAT1 could guide precision oncology approaches, improving patient stratification. Future research incorporating outcomes data and EV subpopulation analysis is needed to establish clinical relevance. [ABSTRACT FROM AUTHOR]

Background Graduate medical educators interested in designing and conducting education research may seek foundational general overview articles on education research methods. Objective We aimed to identify the most useful foundational education research methods articles for medical educators. Methods We identified candidate articles through a 2020 Ovid MEDLINE literature search augmented by the authors' personal files and by cross-checking references of included articles. Articles that were primarily about general education research principles were included; articles were excluded if they were not focused on medical education research methods, were published prior to the year 2000, were written in a non-English language, or had no available abstracts. We conducted a modified Delphi study with 10 participants representing a range of specialties and education research experience to find consensus about the most useful articles. We planned 3 rounds of the Delphi process, the first to eliminate any articles not deemed useful for this audience, and the second and third rounds to include articles that at least 80% of the panel deemed "most useful" to education researchers. Results Of 25 relevant articles identified in the literature search: one was excluded in round 1, 7 met the a priori threshold of 80% agreement for inclusion in round 2, and an additional 2 met inclusion in round 3. These 9 foundational education research methods articles relevant to graduate medical educators are described, along with a capsule summary and specific use for education researchers. Conclusions Our modified Delphi study of foundational education research methods articles identified 9 articles deemed useful for graduate medical educators who are seeking methods resources. [ABSTRACT FROM AUTHOR]

Objectives: Faculty development is essential for academic emergency physicians to maintain clinical skills and succeed in administrative and leadership roles and for career advancement and satisfaction. Faculty developers in emergency medicine (EM) may struggle to find shared resources to guide faculty development efforts in a way that builds on existing knowledge. We aimed to review the EM‐specific faculty development literature since 2000 and come to a consensus about the most useful for EM faculty developers. Methods: A database search was conducted on the topic of faculty development in EM from 2000 to 2020. After identifying relevant articles, we performed a modified Delphi process in three rounds, using a team of educators with a range of experiences with faculty development and education research, to identify articles that would be most useful to a broad audience of faculty developers. Results: We identified 287 potentially relevant articles on the topic of EM faculty development, 244 from the initial literature search, 42 from manual review of the references of the papers meeting inclusion criteria, and one by our study group's recommendation. Thirty‐six papers met final inclusion criteria and underwent full‐text review by our team. The Delphi process yielded six articles that were deemed most highly relevant over the three rounds. Each of these articles is described here, along with summaries and implications for faculty developers. Conclusions: We present the most useful EM papers from the past two decades for faculty developers seeking to develop, implement, or revise faculty development interventions. [ABSTRACT FROM AUTHOR]

Polymerase eta (or Pol η or POLH) is a specialized DNA polymerase that is able to bypass certain blocking lesions, such as those generated by ultraviolet radiation (UVR) or cisplatin, and is deployed to replication foci for translesion synthesis as part of the DNA damage response (DDR). Inherited defects in the gene encoding POLH (a.k.a., XPV) are associated with the rare, sun-sensitive, cancer-prone disorder, xeroderma pigmentosum, owing to the enzyme's ability to accurately bypass UVR-induced thymine dimers. In standard-of-care cancer therapies involving platinum-based clinical agents, e.g., cisplatin or oxaliplatin, POLH can bypass platinum-DNA adducts, negating benefits of the treatment and enabling drug resistance. POLH inhibition can sensitize cells to platinum-based chemotherapies, and the polymerase has also been implicated in resistance to nucleoside analogs, such as gemcitabine. POLH overexpression has been linked to the development of chemoresistance in several cancers, including lung, ovarian, and bladder. Co-inhibition of POLH and the ATR serine/threonine kinase, another DDR protein, causes synthetic lethality in a range of cancers, reinforcing that POLH is an emerging target for the development of novel oncology therapeutics. Using a fragment-based drug discovery approach in combination with an optimized crystallization screen, we have solved the first X-ray crystal structures of small novel drug-like compounds, i.e., fragments, bound to POLH, as starting points for the design of POLH inhibitors. The intrinsic molecular resolution afforded by the method can be quickly exploited in fragment growth and elaboration as well as analog scoping and scaffold hopping using medicinal and computational chemistry to advance hits to lead. An initial small round of medicinal chemistry has resulted in inhibitors with a range of functional activity in an in vitro biochemical assay, leading to the rapid identification of an inhibitor to advance to subsequent rounds of chemistry to generate a lead compound. Importantly, our chemical matter is different from the traditional nucleoside analog-based approaches for targeting DNA polymerases. [ABSTRACT FROM AUTHOR]

Hydroxynitrile lyases (HNL's) belonging to the α/β-hydrolase-fold superfamily evolved from esterases approximately 100 million years ago. Reconstruction of an ancestral hydroxynitrile lyase in the α/β-hydrolase fold superfamily yielded a catalytically active hydroxynitrile lyase, HNL1. Several properties of HNL1 differ from the modern HNL from rubber tree (HbHNL). HNL1 favors larger substrates as compared to HbHNL, is two-fold more catalytically promiscuous for ester hydrolysis (p-nitrophenyl acetate) as compared to mandelonitrile cleavage, and resists irreversible heat inactivation to 35 °C higher than for HbHNL. We hypothesized that the x-ray crystal structure of HNL1 may reveal the molecular basis for the differences in these properties. The x-ray crystal structure solved to 1.96-Å resolution shows the expected α/β-hydrolase fold, but a 60% larger active site as compared to HbHNL. This larger active site echoes its evolution from esterases since related esterase SABP2 from tobacco also has a 38% larger active site than HbHNL. The larger active site in HNL1 likely accounts for its ability to accept larger hydroxynitrile substrates. Site-directed mutagenesis of HbHNL to expand the active site increased its promiscuous esterase activity 50-fold, consistent with the larger active site in HNL1 being the primary cause of its promiscuous esterase activity. Urea-induced unfolding of HNL1 indicates that it unfolds less completely than HbHNL (m-value = 0.63 for HNL1 vs 0.93 kcal/mol·M for HbHNL), which may account for the ability of HNL1 to better resist irreversible inactivation upon heating. The structure of HNL1 shows changes in hydrogen bond networks that may stabilize regions of the folded structure. [ABSTRACT FROM AUTHOR]

Purpose: 10-15% of prostate cancers (PCa) harbor recurrent FOXA1 aberrations whereby the alteration type and the effect on the forkhead( FKH) domain impacts protein-function. We developed a FOXA1 classification system to inform clinical management., Experimental Design: 5,014 PCa were examined using whole exome and transcriptome sequencing from the Caris database. We denoted class 1 FOXA1 alterations as missense and in-frame insertions/deletions with subclasses oriented with respect to the FKH domain: these were in the first part of the FKH domain (class 1A: amino acids [AA] 168-246), within the Wing2 region of FKH (class 1B: AA 247-269), or outside FKH (class 1C: AA 1-167, 270+). Two hotspot missense mutations at R219 were denoted class 2. Class 3 included predicted-truncating mutations with subclasses partitioned based on the FKH domain (class 3A: AA 1-269, class 3B: AA 270+). Class 4 represented FOXA1 amplifications. Real-world overall survival and therapy outcomes were determined from insurance claims., Results: FOXA1 alterations did not influence survival when considered in aggregate, but had distinct prognostic effects when stratified by class. Class 1A alterations were associated with overall improved survival (HR=0.57, p=0.03); a similar trend was seen with Class 1B (HR=0.88, p=0.07). Conversely, class 1C exhibited worse survival upon 2nd-generation androgen receptor signaling inhibitor (ARSI) treatment (HR=1.93, p<0.001). Class 2 mutations (R219C/S) were enriched in neuroendocrine prostate cancers and were associated with overall poor survival (HR=2.05, p<0.001) and worse outcomes to first-line androgen-deprivation therapies (HR=2.5, p<0.001). Class 3A alterations indicated improved survival (HR=0.70; p=0.01) whereas class 3B alterations portended poor outcomes (HR=1.50; p<0.001). Amplifications (class 4) indicated poor outcomes (HR=1.48; p=0.02). Molecularly, different FOXA1 alteration classes harbored distinct mutational and immunologic features as well as unique transcriptional programs. Finally, relative to European-Americans, African-Americans had increased class 1C alterations whereas Asian-Pacific patients had increased class 1B alterations., Conclusions: FOXA1alterations should not be interpreted in aggregate, as different classes are associated with divergent molecular features and clinical outcomes. Our revised classification schema facilitates clinical decision making for PCa patients and uncovers important racial differences.

Audience: The aim of this simulation case is to educate senior medical students, resident physicians, and advanced practice providers on the recognition, diagnosis, and management of spinal epidural abscesses. This scenario is most applicable to the emergency medicine setting but can be applied to the outpatient office or urgent care settings., Introduction: Spinal epidural abscess is an infection leading to an epidural collection of purulent material. This uncommon condition is estimated to occur less than 12 times per 100,000 hospital admissions.1,2 However, this infection can lead to devastating neurological sequelae via cord compression, spinal vascular interruption, and inflammatory etiologies;3,4 thus, prompt diagnosis is essential. Unfortunately, spinal epidural abscesses may be difficult to identify clinically due to variable clinical presentations. The goal of this scenario is to increase awareness of this critical diagnosis.Detailed history-taking to identify risk factors will aid in the recognition of spinal epidural abscesses. Many of the risk factors are related to increased infectious risk from hematogenous spread, iatrogenic inoculation, or direct extension.1 Individuals with conditions including intravenous (IV) drug use, alcohol abuse, diabetes, human immunodeficiency virus (HIV), cancer, hepatic disease, renal disease, and other immunocompromising conditions are at increased risk of developing epidural abscesses.1 Primary infectious sources include dental abscesses, endocarditis, vertebral osteomyelitis, and soft tissue infections. Spinal procedures including spinal surgeries, paraspinal injections, and placement of epidural catheters or stimulators can also predispose to infection.2,4Classic symptoms for spinal epidural abscesses include fever, back pain and neurological changes.1,5 Back pain is the most frequent presenting symptom, occurring about 70%-90% of the time.1 However, fever is the least frequent presenting symptom4 and neurological findings only occur in about one-third of cases.2 Neurological symptoms include motor weakness, sensory changes, urinary retention, overflow urinary incontinence, bowel dysfunction, hyperreflexia, radicular pain, spinal shock or cauda equina syndrome.1,4Laboratory findings may include systemic leukocytosis and elevated inflammatory markers. Whereas leukocytosis is estimated to be present in two-thirds of cases,2 Davis, et al. showed that with the concurrent presence of a risk factor, an elevated erythrocyte sedimentation rate (ESR) had 100% sensitivity and 67% specificity for spinal epidural abscesses.5Magnetic resonance imaging (MRI) with gadolinium contrast is the preferred imaging modality for diagnosing spinal epidural abscesses. Computed tomography (CT) with myelography can be considered if MRI is contraindicated.1 Given that abscesses may be multifocal, further spinal imaging beyond a single spinal segment should be considered during evaluation. Lumbar puncture is not recommended due to risk of iatrogenic infectious spread.Treatment of epidural abscesses includes obtaining blood cultures and prompt antibiotic administration with early surgical evaluation to determine if operative intervention is warranted. Staphylococcus aureus is the most common microbial cause, contributing to about two-thirds of cases.3,4 Other microbial causes include coagulase-negative Staphylococcus (ie, Staphylococcus epidermidis ), Streptococcus , gram-negative bacilli (ie, Pseudomonas aeruginosa and E. coli ), and less commonly, anaerobic bacteria, fungi, mycobacteria and parasites.1,2 Empiric antibiotic treatments generally include vancomycin and a third- or fourth- generation cephalosporin.2,4This simulation session will highlight the importance of recognizing and aggressively treating this uncommon but potentially devastating condition., Educational Objectives: After this simulation case, learners will be able to diagnose and manage patients with spinal epidural abscesses. Specifically, learners will be able to:Obtain a detailed history, including past infectious, surgical, procedural and social history to evaluate for epidural abscess risk factors. Describe clinical signs and symptoms of spinal epidural abscesses and understand that initial clinical presentations can be variable.Perform a focused neurological exam including evaluation of motor, sensory, reflexes, and rectal tone.Order appropriate laboratory testing and imaging modalities for spinal epidural abscess diagnosis, including a post-void bladder residual volume.Select appropriate antibiotics for empiric treatment of spinal epidural abscess depending on patient presentation.Disposition the patient to appropriate inpatient care., Educational Methods: The authors conducted this simulation case with a standardized patient. We encourage inclusion of a standardized patient versus a mannequin to provide appropriate motor and sensory exams. For those without a standardized patient program, the authors suggest utilizing a faculty member as the patient. Regardless of individual used, it is strongly recommended that facilitators rehearse the case with the individual in the patient role ahead of time in order to ensure that their performance reflects an accurate neurologic exam. A debriefing session and small-group discussion followed the simulation to review the clinical presentation, diagnosis, management, and treatment of spinal epidural abscesses. This case can also be adapted as an oral boards case., Research Methods: Residents were provided a survey at the completion of the debriefing session to rate different aspects of the simulation, as well as to provide qualitative feedback on the scenario. This survey is specific to our institution's simulation center., Results: While qualitative feedback from the residents was positive, it was viewed as a straightforward case. Our initial presenting symptom was difficulty ambulating with a fever at home, if asked. The residents appreciated performing a neurologic exam on a standardized patient versus attempting this on a mannequin.Our simulation center's feedback form is based on the Center of Medical Simulation's Debriefing Assessment for Simulation in Healthcare (DASH) Student Version Short Form with the inclusion of required qualitative feedback if an element was scored less than a 6 or 7. This session received all 7 scores (extremely effective/outstanding) other than one 5 score for the element assessing if the instructor set the stage for an engaging learning experience. The learner's feedback for this 5 score was "kinda went right into the case which was ok." Our form also includes an area for general feedback about the case at the end. Comments included "Great sim. Expert case writing," "Fun case and learned a lot," and "Great case! Appreciated feedback on consulting and the difficult consultant situation.", Discussion: This is a cost-effective method for reviewing epidural abscess. We chose a chief complaint and history that was slightly atypical from "classic" presentations, but not so esoteric that the residents felt cheated at the end of the scenario. When using a standardized patient in a scenario that may involve a sensitive physical exam, we review with learners and the standardized patient what expectations are during the pre-brief session. For example, residents may say, "we would like to check to see if rectal tone is intact," and then the standardized patient would verbalize back the expected physical exam findings., Topics: Medical simulation, spinal epidural abscess, spinal cord compression, infectious disease., (© 2020 Lou, et al.)