Trends in pre-biopsy MRI usage for prostate cancer detection, 2007-2022.

BACKGROUND: Clinical guidelines favor MRI before prostate biopsy due to proven benefits. However, adoption patterns across the US are unclear. METHODS: This study used the Merative™ Marketscan® Commercial & Medicare Databases to analyze 872,829 prostate biopsies in 726,663 men from 2007-2022. Pre-biopsy pelvic MRI within 90 days was the primary outcome. Descriptive statistics and generalized estimating equations assessed changes over time, urban-rural differences, and state-level variation. RESULTS: Pre-biopsy MRI utilization increased significantly from 0.5% in 2007 to 35.5% in 2022, with faster adoption in urban areas (36.1% in 2022) versus rural areas (28.3% in 2022). Geographic disparities were notable, with higher utilization in California, New York, and Minnesota, and lower rates in the Southeast and Mountain West. CONCLUSIONS: The study reveals a paradigm shift in prostate cancer diagnostics towards MRI-guided approaches, influenced by evolving guidelines and clinical evidence. Disparities in access, particularly in rural areas and specific regions, highlight the need for targeted interventions to ensure equitable access to advanced diagnostic techniques.

Effects of Melatonin on Sleep Quality and Patient-Reported Outcomes After Arthroscopic Rotator Cuff Surgery: A Prospective Randomized Controlled Trial.

BACKGROUND: Sleep disturbance is a significant symptom associated with both rotator cuff tears and arthroscopic rotator cuff repair. Melatonin has been shown to be safe and effective in managing multiple sleep disorders, including secondary sleep disorders, with relatively minor adverse effects and lack of addictive potential. PURPOSE: To investigate the effects of oral melatonin on postoperative sleep quality after arthroscopic rotator cuff repair. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: This was a prospective randomized clinical trial evaluating patients undergoing arthroscopic rotator cuff repair. Exclusion criteria included history of alcohol abuse, current antidepressant or sedative use, revision rotator cuff repair, severe glenohumeral arthritis, and concurrent adhesive capsulitis. Patients were randomly assigned in a 1:1 ratio to 1 of 2 groups: 5-mg dose of melatonin 1 hour before bedtime or standard sleep hygiene (≥6 hours per night, avoiding caffeine and naps in the evening). Patients in the melatonin group took their assigned melatonin dose for 6 weeks beginning the day of surgery. Patient-reported outcome assessments, including the Pittsburgh Sleep Quality Index (PSQI), the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and the Single Assessment Numeric Evaluation (SANE), and pain medication charts were collected preoperatively as well as at 2 weeks, 6 weeks, 3 months, 4 months, and 6 months postoperatively. Numeric variables were analyzed using paired and unpaired t tests, with significance set at P < .05. RESULTS: Eighty patients were included for final analysis (40 in the control group, 40 in the melatonin group). Patient characteristics such as age, sex, race, body mass index, and laterality did not differ significantly (P≥ .05). Preoperative ASES, SANE, and PSQI scores did not differ between groups (P≥ .055). PSQI scores were significantly lower (better quality sleep) in the melatonin group at the 6-week postoperative period (P = .036). There was a positive correlation between how patients rated the intensity of their pain and the PSQI at the 6-week postoperative period (0.566). The PSQI question regarding sleep quality was found to be significantly lower in the melatonin group at the 3-month, 4-month, and 6-month postoperative periods (P = .015, P = .041, and P≤ .05, respectively). SANE scores were significantly lower in the melatonin group (P = .011) at 6 weeks and then higher in the melatonin group (P = .017) at 6 months. ASES scores were significantly higher in the melatonin group at 4 and 6 months (P = .022 and P = .020, respectively). Lastly, patients who were randomized into the melatonin group were found to use significantly less narcotic medication at the 4-month postoperative period (P = .046). CONCLUSION: Melatonin use after arthroscopic rotator cuff repair led to improved sleep quality (PSQI) in the early postoperative period as well as improved functional outcomes (ASES and SANE scores) and decreased narcotic use in the later postoperative period. Patients with significant sleep disturbances associated with rotator cuff repairs may benefit from the use of melatonin. REGISTRATION: NCT04278677 (ClinicalTrials.gov identifier).

Cryoablation Without Excision for Early-Stage Breast Cancer: ICE3 Trial 5-Year Follow-Up on Ipsilateral Breast Tumor Recurrence.

BACKGROUND: The ICE3 trial evaluated the safety and efficacy of cryoablation in women aged ≥60 years with low-risk, early-stage breast cancers, aiming to provide a non-operative treatment option and avoid potential surgical risks. This study presents 5-year follow-up trial results. METHODS: The ICE3 trial is an Institutional Review Board-approved, prospective, multicentered, non-randomized trial including women ≥ 60 years of age with unifocal, ultrasound visible, invasive ductal carcinoma ≤ 1.5 cm in size, histologic grade 1-2, hormone receptor (HR)-positive, and human epidermal growth factor receptor 2 (HER2)-negative. The primary study endpoint of 5-year ipsilateral breast tumor recurrence (IBTR) was evaluated based on Kaplan-Meier estimates. RESULTS: Overall, 194 patients meeting eligibility received successful cryoablation treatment per protocol and were included for analysis. The mean age was 74.9 years (55-94) with a mean tumor size of 7.4 mm transverse (2.8-14.0 mm) and 8.1 mm sagittal (2.5-14.9 mm). With a mean follow-up period of 54.16 months, the IBTR rate at 5 years was 4.3% and breast cancer survival was 96.7%. Of the 124 patients who received endocrine therapy only, the IBTR was 3.7%. No serious device-related adverse events were reported. Minor (88.2%) and moderate (9.6%) adverse events were mild in severity and resolved without residual effects. Quality-of-life score demonstrated statistically significant improvement (p < 0.001) in distress at 6 months as compared with baseline. CONCLUSIONS: Breast cryoablation presents a promising alternative to surgery in selected patients, offering the benefits of a minimally invasive procedure with minimal risks. Further studies are encouraged to confirm cryoablation as a viable alternative to surgical excision low-risk patients.

Effects of periodic bottlenecks on the dynamics of adaptive evolution in microbial populations.

Population bottlenecks can impact the rate of adaptation in evolving populations. On the one hand, each bottleneck reduces the genetic variation that fuels adaptation. On the other hand, each founder that survives a bottleneck can undergo more generations and leave more descendants in a resource-limited environment, which allows surviving beneficial mutations to spread more quickly. A theoretical model predicted that the rate of fitness gains should be maximized using ~8-fold dilutions. Here we investigate the impact of repeated bottlenecks on the dynamics of adaptation using numerical simulations and experimental populations of Escherichia coli. Our simulations confirm the model's prediction when populations evolve in a regime where beneficial mutations are rare and waiting times between successful mutations are long. However, more extreme dilutions maximize fitness gains in simulations when beneficial mutations are common and clonal interference prevents most of them from fixing. To examine these predictions, we propagated 48 E. coli populations with 2-, 8-, 100-, and 1000-fold dilutions for 150 days. Adaptation began earlier and fitness gains were greater with 100- and 1000-fold dilutions than with 8-fold dilutions, consistent with the simulations when beneficial mutations are common. However, the selection pressures in the 2-fold treatment were qualitatively different from the other treatments, violating a critical assumption of the model and simulations. Thus, varying the dilution factor during periodic bottlenecks can have multiple effects on the dynamics of adaptation caused by differential losses of diversity, different numbers of generations, and altered selection.

Developing Evidence to Support Policy: Protocol for the StrAtegic PoLicy EvIdence-Based Evaluation CeNTer (SALIENT).

BACKGROUND: All federal agencies are required to support appropriation requests with evidence and evaluation (US Public Law 115-435; the Evidence Act). The StrAtegic PoLicy EvIdence-Based Evaluation CeNTer (SALIENT) is 1 of 6 centers that help the Department of Veterans Affairs (VA) meet this requirement. OBJECTIVE: Working with the existing VA evaluation structure, SALIENT evaluations will contribute to (1) optimize policies and programs for veteran populations; (2) improve outcomes regarding health, equity, cost, and provider well-being; (3) advance the science of dissemination and knowledge translation; and (4) expand the implementation and dissemination science workforce. METHODS: We leverage the Lean Sprint methodology (iterative, incremental, rule-governed approach to clearly defined, and time-boxed work) and 3 cores to develop our evaluation plans collaboratively with operational partners and key stakeholders including veterans, policy experts, and clinicians. The Operations Core will work with evaluation teams to develop timelines, facilitate work, monitor progress, and guide quality improvement within SALIENT. The Methods Core will work with evaluation teams to identify the most appropriate qualitative, quantitative, and mixed methods approaches to address each evaluation, ensure that the analyses are conducted appropriately, and troubleshoot when problems with data acquisition and analysis arise. The Knowledge Translation (KT) Core will target key partners and decision makers using a needs-based market segmentation approach to ensure that needs are incorporated in the dissemination of knowledge. The KT Core will create communications briefs, playbooks, and other materials targeted at these market segments to facilitate implementation of evidence-based practices and maximize the impact of evaluation results. RESULTS: The SALIENT team has developed a center infrastructure to support high-priority evaluations, often to be responsive to shifting operational needs and priorities. Our team has engaged in our core missions and operations to rapidly evaluate a high-priority areas, develop a comprehensive Lean Sprint systems redesign approach to training, and accelerate rapid knowledge translation. CONCLUSIONS: With an array of interdisciplinary expertise, operational partnerships, and integrated resources, SALIENT has an established and evolving infrastructure to rapidly develop and implement high-impact evaluations. Projects are developed with sustained efficiency approaches that can pivot to new priorities as needed and effectively translate knowledge for key stakeholders and policy makers, while creating a learning health system infrastructure to foster the next generation of evaluation and implementation scientists. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/59830.

Ligand-to-metal charge transfer facilitates photocatalytic oxygen atom transfer (OAT) with cis-dioxo molybdenum(vi)-Schiff base complexes.

Systems incorporating the cis-Mo(O)2 motif catalyse a range of important thermal homogeneous and heterogeneous oxygen atom transfer (OAT) reactions spanning biological oxidations to platform chemical synthesis. Analogous light-driven processes could offer a more sustainable approach. The cis-Mo(O)2 complexes reported here photocatalyse OAT under visible light irradiation, and operate via a non-emissive excited state with substantial ligand-to-metal charge-transfer (LMCT) character, in which a Mo[double bond, length as m-dash]O π*-orbital is populated via transfer of electron density from a chromophoric salicylidene-aminophenol (SAP) ligand. SAP ligands can be prepared from affordable commercially-available precursors. The respective cis-Mo(O)2-SAP catalysts are air stable, function in the presence of water, and do not require additional photosensitisers or redox mediators. Benchmark OAT between phosphines and sulfoxides shows that electron withdrawing groups (e.g. C(O)OMe, CF3) are necessary for photocatalytic activity. The photocatalytic system described here is mechanistically distinct from both thermally catalysed OAT by the cis-Mo(O)2 motif, as well as typical photoredox systems that operate by outer sphere electron transfer mediated by long-lived emissive states. Both photoactivated and thermally activated OAT steps are coupled to establish a catalytic cycle, offering new opportunities for the development of photocatalytic atom transfer based on readily-available, high-valent metals, such as molybdenum.

Generative learning activities for online multimedia learning: when summarizing is effective but drawing is not.

Introduction: The goal of this study is to determine whether two commonly used generative learning activities for text-based lessons-writing a summary or creating a drawing-help students learn from a multimedia lesson involving animations with short text captions without prior training in the generative activities. Methods: Students viewed a series of four annotated animations on greenhouse gases. During pauses between the animations, students were asked to generate a written summary, to create a drawing, or to do both, whereas a control group viewed the lesson without any generative learning activities. Students were tested immediately (Experiment 1) or after a one-week delay (Experiment 2). Results: In both experiments, students who produced written summaries scored significantly higher on the posttest than those who engaged in no generative learning activities (d = 0.48 in Experiment 1, d = 0.54 in Experiment 2), but there was no significant difference on the posttest for students who generated drawings compared to those who engaged in no generative learning activities. In addition, those who engaged in drawing and summarizing did not have significantly different posttest performance than those engaged in summarizing alone. Discussion: We conclude that writing summaries during a highly visual animated lesson is effective for learning, possibly because it encourages students to engage in generative processing during learning more than drawing and we discuss potential reasons for this in the discussion. This work helps extend generative learning theory by pinpointing potential boundary conditions for learning by drawing and learning by summarizing.

Predictors of Alcohol Use, Alcohol-Related Problems, and Substance Use Following Adolescent Metabolic and Bariatric Surgery.

Objective: To identify factors associated with incident alcohol consumption, hazardous drinking, alcohol-related problems, and substance use up to 8 years following metabolic and bariatric surgery (MBS) during adolescence. Background: In this cohort, nearly half of those who underwent MBS as adolescents screened positive for alcohol use disorder, symptoms of alcohol-related harm, or alcohol-related problems within 8 years post-surgery. Moreover, persistent or heavy marijuana use following MBS during adolescence is higher than national data. Methods: This study includes 217 adolescents (aged 13-19 years) enrolled in a 5-center prospective cohort study who underwent Roux-en-Y gastric bypass or vertical sleeve gastrectomy between 2007 and 2011 and were followed for up to 8 years. Participants self-reported alcohol use via the Alcohol Use Disorders Identification Test and substance use for up to 8 years. Results: Female sex, pre-surgery lower body mass index, and pre-surgery substance use were independently associated with increased risk of incident post-surgery hazardous drinking. Pre-surgery psychiatric counseling was significantly associated with increased risk for new-onset substance use post-surgery. Starting substance use post-surgery or continuing pre- to post-surgery was independently associated with a higher risk of post-surgery hazardous drinking. Greater percent weight loss, starting post-surgery or continuing pre- to post-surgery psychiatric counseling, using alcohol, and hazardous drinking were independently associated with a higher risk of post-surgery substance use. Conclusions: Future research with a nonsurgical control group should be examined to further elucidate the relationships between MBS and alcohol and substance use following surgery during adolescence.

Differential Association of Preadolescent Risk Factors Across Developmental Patterns of Adolescent Concurrent Gambling Participation and Substance Use.

Early risk factors for gambling participation (GP) and substance use (SU) in adolescents have usually been studied separately, although these disorders were integrated into the same clinical category over a decade ago. This exploratory study aimed to investigate the early individual, parental, familial and social risk factors associated with developmental patterns of adolescent GP and SU in a population-representative cohort (N = 1594, 51.2% boys). Using a person-centered strategy and multiple assessments from age 12 to 17, six developmental patterns describing joint GP and SU courses were revealed. Non-substance users/non-gamblers served as the reference class in an integrated longitudinal-multivariate analysis framework examining 15 distinct risk factors. Results showed that a core of risk factors were common to all trajectory-classes of substance users with or without GP. For a similar level of SU, most of the risk factors associated with non-gambling users also affected their gambling peers. However, additional risk factors were specifically related to GP. Thus, substance users who also gamble were affected by a greater number of risk factors than non-gambling substance users. Findings are consistent with a developmental syndrome of addiction, which posits a shared etiology between different expressions of addiction as well as differences in risk factors that lead to distinct trajectories of addictive behaviors. They highlight the importance of considering both GP and SU for a comprehensive assessment of adolescents' level of risk with regard to addictive behaviors.

Validation of a Simplified Tissue-to-Reference Ratio Measurement Using SUVR to Assess Synaptic Density Alterations in Alzheimer Disease with [11C]UCB-J PET.

Simplified methods of acquisition and quantification would facilitate the use of synaptic density imaging in multicenter and longitudinal studies of Alzheimer disease (AD). We validated a simplified tissue-to-reference ratio method using SUV ratios (SUVRs) for estimating synaptic density with [11C]UCB-J PET. Methods: Participants included 31 older adults with AD and 16 with normal cognition. The distribution volume ratio (DVR) using simplified reference tissue model 2 was compared with SUVR at short scan windows using a whole-cerebellum reference region. Results: Synaptic density was reduced in AD participants using DVR or SUVR. SUVR using later scan windows (60-90 or 70-90 min) was minimally biased, with the strongest correlation with DVR. Effect sizes using SUVR at these late time windows were minimally reduced compared with effect sizes with DVR. Conclusion: A simplified tissue-to-reference method may be useful for multicenter and longitudinal studies seeking to measure synaptic density in AD.

Gasdermin D and Gasdermin E Are Dispensable for Silica-Mediated IL-1ß Secretion from Mouse Macrophages.

Silica crystals activate the NLRP3 inflammasome in macrophages, resulting in the caspase-1-dependent secretion of the proinflammatory cytokine IL-1ß. Caspase-1-mediated cleavage of gasdermin D (GSDMD) triggers the formation of GSDMD pores, which drive pyroptotic cell death and facilitate the rapid release of IL-1ß. However, the role of GSDMD in silica-induced lung injury is unclear. In this study, we show that although silica-induced lung injury is dependent on the inflammasome adaptor ASC and IL-1R1 signaling, GSDMD is dispensable for acute lung injury. Although the early rapid secretion of IL-1ß in response to ATP and nigericin was GSDMD dependent, GSDMD was not required for IL-1ß release at later time points. Similarly, secretion of IL-1ß from macrophages in response to silica and alum proceeded in a GSDMD-independent manner. We further found that gasdermin E did not contribute to macrophage IL-1ß secretion in the absence of GSDMD in vitro and was also not necessary for silica-induced acute lung injury in vivo. These findings demonstrate that GSDMD and gasdermin E are dispensable for IL-1ß secretion in response to silica in vitro and in silica-induced acute lung injury in vivo.

Structural basis of CDNF interaction with the UPR regulator GRP78.

Cerebral dopamine neurotrophic factor (CDNF) is an unconventional neurotrophic factor that is a disease-modifying drug candidate for Parkinson's disease. CDNF has pleiotropic protective effects on stressed cells, but its mechanism of action remains incompletely understood. Here, we use state-of-the-art advanced structural techniques to resolve the structural basis of CDNF interaction with GRP78, the master regulator of the unfolded protein response (UPR) pathway. Subsequent binding studies confirm the obtained structural model of the complex, eventually revealing the interaction site of CDNF and GRP78. Finally, mutating the key residues of CDNF mediating its interaction with GRP78 not only results in impaired binding of CDNF but also abolishes the neuroprotective activity of CDNF-derived peptides in mesencephalic neuron cultures. These results suggest that the molecular interaction with GRP78 mediates the neuroprotective actions of CDNF and provide a structural basis for development of next generation CDNF-based therapeutic compounds against neurodegenerative diseases.

Chemical genetic analysis of enoxolone inhibition of C. difficile toxin production reveals adenine deaminase and ATP synthase as anti-virulence targets.

Toxins TcdA and TcdB are the main virulence factors of Clostridioides difficile, a leading cause of hospital-acquired diarrhea. Despite their importance, there is a significant knowledge gap of druggable targets for inhibiting toxin production. To address this, we screened non-antibiotic phytochemicals to identify potential chemical genetic probes to discover anti-virulence drug targets. This led to the identification of 18ß-glycyrrhetinic acid (enoxolone), a licorice metabolite, as an inhibitor of TcdA and TcdB biosynthesis. Using affinity-based proteomics, potential targets were identified as ATP synthase subunit alpha (AtpA) and adenine deaminase (Ade, which catalyzes conversion of adenine to hypoxanthine in the purine salvage pathway). To validate these targets, a multi-faceted approach was adopted. Gene silencing of ade and atpA inhibited toxin biosynthesis, while SPR and ITC molecular interaction analyses revealed direct binding of enoxolone to Ade. Metabolomics demonstrated enoxolone induced the accumulation of adenosine, while depleting hypoxanthine and ATP in C. difficile. Transcriptomics further revealed enoxolone dysregulated phosphate uptake genes, which correlated with reduced cellular phosphate levels. These findings suggest that enoxolone's cellular action is multi-targeted. Accordingly, supplementation with both hypoxanthine and triethyl phosphate (TEP), a phosphate source, was required to fully restore toxin production in the presence of enoxolone. In conclusion, through the characterization of enoxolone, we identified promising anti-virulence targets that interfere with nucleotide salvage and ATP synthesis, which may also block toxin biosynthesis.

Cold Atmospheric Plasma Induces Growth Arrest and Apoptosis in Neurofibromatosis Type 1-Associated Peripheral Nerve Sheath Tumor Cells.

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder resulting from mutations in the NF1 gene. Patients harboring these mutations are predisposed to a spectrum of peripheral nerve sheath tumors (PNSTs) originating from Schwann cells, of which malignant peripheral nerve sheath tumors (MPNSTs) are the deadliest, with limited treatment options. Therefore, an unmet need still exists for more effective therapies directed at these aggressive malignancies. Cold atmospheric plasma (CAP) is a reactive oxygen species (ROS) and reactive nitrogen species (RNS) generating ionized gas that has been proposed to be a potential therapeutic modality for cancer. In this study, we sought to determine the effects of CAP on NF1-associated PNSTs. Utilizing established mouse and human cell lines to interrogate the effects of CAP in both in vitro and in vivo settings, we found that NF1-associated PNSTs were highly sensitive to CAP exposure, resulting in cell death. To our knowledge, this is the first application of CAP to NF1-associated PNSTs and provides a unique opportunity to study the complex biology of NF1-associated tumors.

Detection of enterovirus RNA in pancreas and lymphoid tissues of organ donors with type 1 diabetes.

Aims/hypothesis: The nPOD-Virus group collaboratively applied innovative technologies to detect and sequence viral RNA in pancreas and other tissues from organ donors with type 1 diabetes. These analyses involved the largest number of pancreas samples collected to date. Methods: We analysed pancreas, spleen, pancreatic lymph nodes, and duodenum samples from the following donor groups: a) donors with type 1 diabetes (n=71), with (n=35) or without (n=36) insulin-containing islets, (b) donors with single or double islet autoantibody positivity without diabetes (n=22) and c) autoantibody-negative donors without diabetes (control donors) (n=74). Five research laboratories participated in this collaborative effort using approaches for unbiased discovery of RNA viruses (two RNA-Seq platforms), targeted detection of Enterovirus A-D species using RT-PCR, and tests for virus growth in cell-culture. Results: Direct RNA-Seq did not detect virus signal in pancreas samples, whereas RT-PCR detected enterovirus RNA confirmed by sequencing in low amounts in pancreas samples in three of the five donor groups, namely donors with type 1 diabetes with insulin-containing islets, 16% (5/32) donors being positive, donors with single islet autoantibody positivity with 53% (8/15) donors being positive, and non-diabetic donors with 8% (4/49) being enterovirus RNA positive. Detection of enterovirus RNA was significantly more frequent in single islet autoantibody-positive donors compared to donors with type 1 diabetes with insulin-deficient islets (p-value <0.001) and control donors (p-value 0.004). In some donors, pancreatic lymph nodes were also positive. RT-PCR detected enterovirus RNA also in spleen of a small number of donors and virus enrichment in susceptible cell lines before RT-PCR resulted in much higher rate in spleen positivity, particularly in donors with type 1 diabetes. Interestingly, the enterovirus strains detected did not cause a typical lytic infection, possibly reflecting their persistence-prone nature. Conclusions/interpretation: This was the largest coordinated effort to examine the presence of enterovirus RNA in pancreas of organ donors with type 1 diabetes, using a multitude of assays. These findings are consistent with the notion that both the subjects with type 1 diabetes and those with islet autoantibodies may carry a low-grade enterovirus infection in the pancreas and lymphoid tissues.

Requested a Different Doctor: Developing and Evaluating an OSCE Assessing Core Skills in Supporting Trainees Facing Patient Discrimination.

BACKGROUND: Suboptimal support for colleagues experiencing discrimination can adversely impact clinician well-being and patient care. AIM: To describe resident performance and experience during an Objective Structured Clinical Examination (OSCE) case centered on supporting a trainee facing discrimination to inform enhanced, supportive learning environments. SETTING: Formative, internal medicine OSCE at a simulation center. PARTICIPANTS: 148 second-year residents across 2018, 2019, 2021, 2022. PROGRAM DESCRIPTION: Residents had 10 min to support a Muslim standardized intern (SI) experiencing discrimination from a patient. The SI rated resident performance across Supervision, Relationship Development, and Support domains and provided written feedback. Post-OSCE evaluations elicited resident reflections on case challenges. PROGRAM EVALUATION: Proficient residents (≥ 80% average score across domains, n = 85) performed better in all items, except in not acting defensive and collaborating with SI to develop follow-up plan, compared to non-proficient residents (n = 65). The SI described effective approaches to feeling supported, including using empathetic statements, stating personal stance on discrimination, exhibiting supportive body language, and verbalizing support. Stating knowledge of situation upfront was an area of improvement. Residents found engaging the distressed SI difficult. DISCUSSION: Use of an explicit discrimination OSCE case can help identify effective approaches to supporting targets of discriminatory patients to inform future training.

A molten globule ensemble primes Arf1-GDP for the nucleotide switch.

The adenosine di-phosphate (ADP) ribosylation factor (Arf) small guanosine tri-phosphate (GTP)ases function as molecular switches to activate signaling cascades that control membrane organization in eukaryotic cells. In Arf1, the GDP/GTP switch does not occur spontaneously but requires guanine nucleotide exchange factors (GEFs) and membranes. Exchange involves massive conformational changes, including disruption of the core ß-sheet. The mechanisms by which this energetically costly switch occurs remain to be elucidated. To probe the switch mechanism, we coupled pressure perturbation with nuclear magnetic resonance (NMR), Fourier Transform infra-red spectroscopy (FTIR), small-angle X-ray scattering (SAXS), fluorescence, and computation. Pressure induced the formation of a classical molten globule (MG) ensemble. Pressure also favored the GDP to GTP transition, providing strong support for the notion that the MG ensemble plays a functional role in the nucleotide switch. We propose that the MG ensemble allows for switching without the requirement for complete unfolding and may be recognized by GEFs. An MG-based switching mechanism could constitute a pervasive feature in Arfs and Arf-like GTPases, and more generally, the evolutionarily related (Ras-like small GTPases) Rags and Gα GTPases.

Spectinamide MBX-4888A exhibits favorable lesion and tissue distribution and promotes treatment shortening in advanced murine models of tuberculosis.

The spectinamides are novel, narrow-spectrum semisynthetic analogs of spectinomycin, modified to avoid intrinsic efflux by Mycobacterium tuberculosis. Spectinamides, including lead MBX-4888A (Lee-1810), exhibit promising therapeutic profiles in mice, as single drugs and as partner agents with other anti-tuberculosis antibiotics including rifampin and/or pyrazinamide. Here, we show that MBX-4888A, given by injection with the front-line standard of care regimen, is treatment shortening in multiple murine tuberculosis infection models. The positive treatment responses to MBX-4888A combination therapy in multiple mouse models, including mice exhibiting advanced pulmonary disease, can be attributed to favorable distribution in tissues and lesions, retention in caseum, along with favorable effects with rifampin and pyrazinamide under conditions achieved in necrotic lesions. This study also provides an additional data point regarding the safety and tolerability of spectinamide MBX-4888A in long-term murine efficacy studies.

TDRD3 functions as a selective autophagy receptor with dual roles in autophagy and modulation of stress granule stability.

Tudor Domain Containing 3 (TDRD3) is a methylarginine-reader protein that functions as a scaffold in the nucleus facilitating transcription, however TDRD3 is also recruited to stress granules (SGs) during the Integrated Stress Response (ISR) although its function therein remains largely unknown. We previously showed that TDRD3 is a novel antiviral restriction factor that is cleaved by virus 2A protease, and plays complex modulatory roles in both interferon and inflammatory signaling during stress and enterovirus infections. Here we have found that TDRD3 contains structural motifs similar to known selective autophagy receptors such as p62/SQSTM1, sharing ubiquitin associated domains (UBA) and LC3 interacting regions (LIR) that anchor cargo destined for autophagosomes to activated LC3 protein coating autophagosome membranes. This is of interest since enteroviruses hijack autophagy machinery to facilitate formation of viral replication factories, virus assembly and egress from the infected cell. Here we explored possible roles of TDRD3 in autophagy, hypothesizing that TDRD3 may function as a specialized selective autophagy receptor. We found that KO of TDRD3 in HeLa cells significantly reduces starvation induced autophagy, while its reintroduction restores it in a dose-dependent manner. Autophagy receptors are degraded during autophagy and expression levels decrease during this time. We found that TDRD3 levels decrease to the same extent as the autophagy receptor p62/SQSTM1 during autophagy, indicating autophagy-targeted turnover in that role. Knockout of TDRD3 or G3BP1 did not make significant changes in overall cell localization of LC3B or p62/SQSTM1, but did result in greater concentration of Lamp2 phagosome marker for phagosomes and phagolysosomes. To test the potential roles of TDRD3 in autophagic processes, we created a series of deletion mutants of TDRD3 lacking either UBA domain or the various LIR motifs that are predicted to interact with LC3B. Microscopic examination of starved cells expressing these variants of TDRD3 showed ΔLIR-TDRD3 had defects in colocalization with LC3B or Lamp2. Further, super resolution microscopy revealed ring structures with TDRD3 interfacing with p62/SQSTM1. In examination of arsenite induced stress granules we found recruitment of TDRD3 variants disrupted normally tight SG condensation, altered the decay rate of SGs upon release from stress and the kinetics of SG formation. We found evidence that the LIR3 motif on TDRD3 is involved in TDRD3 interaction with LC3B in coIP experiments, colocalization studies, and that this motif plays a key role in TDRD3 recruitment to SGs and SG resolution. Overall, these data support a functional role of TDRD3 in selective autophagy in a mode similar to p62/SQSTM1, with specific roles in SG stability and turnover. Enterovirus cleavage of TDRD3 likely affects both antiviral and autophagic responses that the virus controls for replication.

Organic matter is a predominant control on total mercury concentration of near-surface lake sediments across a boreal to low Arctic tundra transect in northern Canada.

Mercury (Hg) is a bioavailable and toxic element with concentrations that are persistently high or rising in some Arctic and subarctic lakes despite reduced atmospheric emissions in North America. This is due to rising Hg emissions to the atmosphere outside of North America, enhanced sequestration of Hg to sediments by climate-mediated increases in primary production, and ongoing release of Hg from terrestrial reservoirs. To evaluate the influence of organic matter and other parameters on Hg accumulation in northern lakes, near-surface sediments were sampled from 60 lakes across a boreal to shrub tundra gradient in the central Northwest Territories, Canada. The organic matter of the lake sediments, assessed using programmed pyrolysis and petrology, is composed of a mixture of terrestrial, aquatic, and inert organic matter. The proportion of algal-derived organic matter is higher in sediments of lakes below treeline relative to shrub tundra sites. Total sedimentary Hg concentration is correlated to all organic matter constituents but is unrelated to latitude or lake position below or above treeline. The concentrations of Ag, Ca, P, S, U, Ti, Y, S, Cd, and Zn are also strong predictors of total sedimentary Hg concentration, indicating input from a common geogenic source and/or common sequestration pathways associated with organic matter. Catchment area is a strong negative predictor of total sedimentary Hg concentration, particularly in lakes above treeline, possibly due to retention capacity of Hg and other elements in local sinks. This research highlights the complexity of controls on Hg sequestration in sediment and shows that while organic matter is a strong predictor of total sedimentary Hg concentration on a landscape scale and across extreme gradients in climate and associated vegetation and permafrost, other factors such as catchment area and sources from mineralized bedrock are also important.