Mammalian oocytes store proteins for the early embryo on cytoplasmic lattices.

Mammalian oocytes are filled with poorly understood structures called cytoplasmic lattices. First discovered in the 1960s and speculated to correspond to mammalian yolk, ribosomal arrays, or intermediate filaments, their function has remained enigmatic to date. Here, we show that cytoplasmic lattices are sites where oocytes store essential proteins for early embryonic development. Using super-resolution light microscopy and cryoelectron tomography, we show that cytoplasmic lattices are composed of filaments with a high surface area, which contain PADI6 and subcortical maternal complex proteins. The lattices associate with many proteins critical for embryonic development, including proteins that control epigenetic reprogramming of the preimplantation embryo. Loss of cytoplasmic lattices by knocking out PADI6 or the subcortical maternal complex prevents the accumulation of these proteins and results in early embryonic arrest. Our work suggests that cytoplasmic lattices enrich maternally provided proteins to prevent their premature degradation and cellular activity, thereby enabling early mammalian development.

An octameric PqiC toroid stabilises the outer-membrane interaction of the PqiABC transport system.

The E. coli Paraquat Inducible (Pqi) Pathway is a putative Gram-negative phospholipid transport system. The pathway comprises three components: an integral inner membrane protein (PqiA), a periplasmic spanning MCE family protein (PqiB) and an outer membrane lipoprotein (PqiC). Interactions between all complex components, including stoichiometry, remain uncharacterised; nevertheless, once assembled into their quaternary complex, the trio of Pqi proteins are anticipated to provide a continuous channel between the inner and outer membranes of diderms. Here, we present X-ray structures of both the native and a truncated, soluble construct of the PqiC lipoprotein, providing insight into its biological assembly, and utilise neutron reflectometry to characterise the nature of the PqiB-PqiC-membrane interaction. Finally, we employ phenotypic complementation assays to probe specific PqiC residues, which imply the interaction between PqiB and PqiC is less intimate than previously anticipated.

Lasting Impact of the COVID-19 Pandemic on Care and Prevention of Sexually Transmitted Infections in the Midwest.

BACKGROUND: The COVID-19 pandemic reduced the general accessibility of health services. Many sexually transmitted infection (STI) testing and treatment sites modified services (e.g., reduced hours, limited walk-in availability, decreased testing capacity), changes that may result in permanent change in STI service availability. At the same time, systems were driven to innovate in ways that could benefit patients. This study aimed to describe how the COVID-19 pandemic changed STI clinical services, with a focus on long-term impacts. METHODS: In July 2022, a phone survey was designed to assess services for STIs at the 105 STI testing and treatment providers in the St. Louis metropolitan statistical area. Sexually transmitted infection testing providers included STI clinics, primary care clinics that cater to a broad population, and community-based organizations, and excluded emergency departments and urgent care centers. In most cases, the survey was completed by a clinic manager, medical director, or nursing staff member. RESULTS: Of the 75 locations that were interviewed, 12 (16%) had not returned to prepandemic capacity and operations as of July 2022. Five sites had closed completely since the pandemic began, 3 of which are in the northwestern region of the metropolitan statistical area. Most (58.6%) of the open clinics had added telehealth appointments. CONCLUSIONS: Sexually transmitted infection testing sites decreased during the pandemic with lasting impact in one area of the Midwest. Resources to support STI infrastructure should be expanded. Maintaining updated information on STI care providers in the region can aid future assessments.

Target Enrichment and Extensive Population Sampling Help Untangle the Recent, Rapid Radiation of Oenothera Sect. Calylophus.

Oenothera sect. Calylophus is a North American group of 13 recognized taxa in the evening primrose family (Onagraceae) with an evolutionary history that may include independent origins of bee pollination, edaphic endemism, and permanent translocation heterozygosity. Like other groups that radiated relatively recently and rapidly, taxon boundaries within Oenothera sect. Calylophus have remained challenging to circumscribe. In this study, we used target enrichment, flanking noncoding regions, gene tree/species tree methods, tests for gene flow modified for target-enrichment data, and morphometric analysis to reconstruct phylogenetic hypotheses, evaluate current taxon circumscriptions, and examine character evolution in Oenothera sect. Calylophus. Because sect. Calylophus comprises a clade with a relatively restricted geographic range, we were able to extensively sample across the range of geographic, edaphic, and morphological diversity in the group. We found that the combination of exons and flanking noncoding regions led to improved support for species relationships. We reconstructed potential hybrid origins of some accessions and note that if processes such as hybridization are not taken into account, the number of inferred evolutionary transitions may be artificially inflated. We recovered strong evidence for multiple evolutionary origins of bee pollination from ancestral hawkmoth pollination, edaphic specialization on gypsum, and permanent translocation heterozygosity. This study applies newly emerging techniques alongside dense infraspecific sampling and morphological analyses to effectively reconstruct the recalcitrant history of a rapid radiation. [Gypsum endemism; Oenothera sect. Calylophus; Onagraceae; phylogenomics; pollinator shift; recent radiation; target enrichment.].

Long-Term Impact of COVID-19 Related Disruption of National Health Service Elective Services on Emergency Major Lower Limb Amputations.

BACKGROUND: The COVID-19 pandemic has affected the healthcare systems worldwide since the dawn of 2020. In March 2020, the United Kingdom government announced the first national lockdown which severely disturbed all National Health Service (NHS) healthcare elective services. Our aim is to assess the long-term impact of COVID-19 related disruption of NHS elective services on emergency major lower limb amputations (MLLAs). METHODS: Patients' data for emergency MLLA for critical limb-threatening ischemia and diabetic foot infections performed at Aberdeen Royal Infirmary was collected through Trakcare and divided into the control prepandemic group (April 2018-March 2020) and the pandemic group (April 2020-March 2022). The statistical analysis was conducted using the IBM SPSS software (v28.0.1.1 [14]). RESULTS: A total of 358 patients underwent MLLA and 206 (57.5%) of these had diabetes mellitus. There was a 17% increase in the number of urgent referrals and every 1 in 5 of these finally underwent an amputation. There was an increase in the absolute number of Above- and Below-Knee amputations. There was a statistically significant increase by 33% in emergency MLLAs during the pandemic period (P < 0.05). A total of 165 postoperative deaths up to December 2022 were recorded with 30-day mortality rate of 7.26% (n = 26). CONCLUSIONS: NHS vascular management groups should update themselves with evolving technologies to optimize the care provided during future unprecedented times. Furthermore, more effective measures should also be implemented to avoid delayed presentations, which can potentially lead to higher rates of major limb amputations.

Personal goals of young survivors of violent injury: implications for practice.

INTRODUCTION: Firearm injuries are the leading cause of death among young people in the USA and disproportionately impact communities of colour and those experiencing socioeconomic distress. Understanding the personal goals of violently injured patients is essential to identifying protective factors and developing interventions that promote them. However, limited research characterising these personal goals exists. OBJECTIVE: The objective of this study was to use qualitative thematic analysis to analyse and describe the personal goals of young people who enrolled in a region-wide hospital-based violence intervention programme after surviving a violent injury. METHODS: A qualitative coding framework was developed, evaluated, and implemented using data from Life Outside of Violence, the St. Louis Area Hospital-Based Violence Intervention Programme. Chart abstraction procedures were used to compile qualitative data on Life Outside of Violence participants' personal goals documented by clinical case managers during individual treatment planning sessions with participants (n=168). Descriptive analyses are reported and implications for practice are discussed. RESULTS: Key findings reveal that (1) violent injury survivors have unmet therapeutic and resource needs, indicating the importance of having service providers with both clinical and case management skills, (2) anger management is a common clinical goal, and (3) employment opportunities are a common resource need. CONCLUSIONS: Findings from this study inform the implementation of the Life Outside of Violence programme and offer a roadmap to other hospital-based violence intervention programmes operating nation-wide. Our results provide insight into participants' needs, desires, and motivations, allowing unique opportunities for improved participant engagement and service delivery.

Incidence of and Factors Associated With Recurrent Firearm Injury Among Patients Presenting to St. Louis Trauma Centers, 2010 to 2019 : A Cohort Study.

BACKGROUND: Firearm injuries are a public health crisis in the United States. OBJECTIVE: To examine the incidence and factors associated with recurrent firearm injuries and death among patients presenting with an acute (index), nonfatal firearm injury. DESIGN: Multicenter, observational, cohort study. SETTING: Four adult and pediatric level I trauma hospitals in St. Louis, Missouri, 2010 to 2019. PARTICIPANTS: Consecutive adult and pediatric patients (n = 9553) presenting to a participating hospital with a nonfatal acute firearm injury. MEASUREMENTS: Data on firearm-injured patient demographics, hospital and diagnostic information, health insurance status, and death were collected from the St. Louis Region-Wide Hospital-Based Violence Intervention Program Data Repository. The Centers for Disease Control and Prevention (CDC) Social Vulnerability Index was used to characterize the social vulnerability of the census tracts of patients' residences. Analysis included descriptive statistics and time-to-event analyses estimating the probability of experiencing a recurrent firearm injury. RESULTS: We identified 10 293 acutely firearm-injured patients of whom 9553 survived the injury and comprised the analytic sample. Over a median follow-up of 3.5 years (IQR, 1.5 to 6.4 years), 1155 patients experienced a recurrent firearm injury including 5 firearm suicides and 149 fatal firearm injuries. Persons experiencing recurrent firearm injury were young (25.3 ± 9.5 years), predominantly male (93%), Black (96%), and uninsured (50%), and resided in high social vulnerability regions (65%). The estimated risk for firearm reinjury was 7% at 1 year and 17% at 8 years. LIMITATIONS: Limited data on comorbidities and patient-level social determinants of health. Inability to account for recurrent injuries presenting to nonstudy hospitals. CONCLUSION: Recurrent injury and death are frequent among survivors of firearm injury, particularly among patients from socially vulnerable areas. Our findings highlight the need for interventions to prevent recurrence. PRIMARY FUNDING SOURCE: Emergency Medicine Foundation-AFFIRM and Missouri Foundation for Health.

Judicious use of corticosteroid injections prior to shoulder arthroplasty does not compromise outcomes at a minimum of 2 years following surgery.

BACKGROUND: The use of total shoulder arthroplasty is continuing to rise with its expanding indications. For patients with chronic conditions, such as glenohumeral arthritis and rotator cuff arthropathy, nonoperative treatment is typically done prior to arthroplasty and often includes corticosteroid injections (CSIs). Recent studies in the shoulder arthroplasty literature as well as applied from the hip and knee literature have focused on the risk of periprosthetic infection. Literature is lacking as to whether the judicious use of corticosteroids in the year prior to arthroplasty influences patient-reported outcomes (PROs). The purpose of this study was to determine if preoperative CSIs prior to shoulder arthroplasty affected 2-year PROs. METHODS: Retrospective review of anatomic and reverse total shoulder arthroplasty (RSA) patients (n = 230) was performed at a single institution including multiple surgeons. Patients were included if they had preoperative and a minimum of 2-year postoperative PROs, including: American Shoulder and Elbow Surgeons (ASES), visual analog scale, Single Assessment Numeric Evaluation, Veteran's RAND 12 Physical Component Score, and Veteran's RAND 12 Mental Component Score. Patients were included in the injection group if they had received an injection, either glenohumeral or subacromial, within 12 months prior to arthroplasty (inject = 134). Subgroup analysis included anatomic (total shoulder arthroplasty [TSA] = 92) and RSA (RSA = 138) as well as those with no injection within 12 months prior to surgery. An analysis of variance was used to compare outcomes between patients who received an injection and those who did not prior to TSA and RSA. RESULTS: There were 230 patients included with 134 patients in the injection group and 96 in the no injection group. Patients who received an injection in the year prior to arthroplasty displayed a significantly higher ASES (82 [16.23 standard deviation] vs. 76 [19.43 standard deviation], P < .01) and Single Assessment Numeric Evaluation (70 [24.49 standard deviation] vs. 63 [29.22 standard deviation], P < .01) scores vs. those who had not received injection. There was no difference when comparing preoperative injection vs. no injection in patients undergoing TSA. Those patients undergoing RSA displayed significantly higher ASES scores (P < .01). There were no significant differences in visual analog scale, Veteran's RAND 12 Physical Component Score, and Veteran's RAND 12 Mental Component Score among any analysis (P > .05), and the minimal clinically important difference in ASES was not different between groups (P.09). CONCLUSION: CSIs within 12 months prior to anatomic and RSA do not compromise PROs during a minimum of 2-year follow-up. Although more complications occurred in the injection group, it did not reach statistical significance and warrants further study in a larger population.

The Role of Radiation Therapy in Adult and Pediatric Keloid Management: A National Survey of Radiation Oncologists.

INTRODUCTION: Radiation therapy is a promising modality for treating keloids after surgical excision. However, it is currently not standard practice among physicians because of concern surrounding the risk of radiation-induced secondary cancers, especially among pediatric patients. There is minimal research assessing the complications for radiation therapy in keloid management. AIM: The goal of this study was to determine radiation oncologists' perspectives about the utility and appropriateness of radiation therapy for keloid management in both adult and pediatric patients. This study also aimed to characterize radiation modality, dose, fractionation, and secondary complications observed by providers. METHODS: An electronic survey was delivered to 3102 members of the American Society for Radiation Oncology. The survey subjects were radiation oncologists who are currently practicing in the United States. Rates of responses were analyzed. RESULTS: A total of 114 responses from practicing radiation oncologists were received. Of these, 113 providers (99.1%) supported radiation therapy for keloid management in adults, whereas only 54.9% supported radiation therapy for pediatric patients. Of 101 providers that treated adults in the past year, the majority used external beam: electrons (84.2%), applied 3 fraction regimens (54.4%), and delivered radiation within 24 hours postexcision (45.5%). In pediatric patients, only 42 providers reported treating at least 1 patient. The majority used electron beam radiation (76.2%), applied 3 faction regimens (65%), and delivered radiation on the same day of keloid excision (50.0%) The main concern when treating pediatric patients were risk of secondary malignancy (92.1%). CONCLUSION: Although radiation therapy appears to be a widely accepted adjuvant treatment option for adults with keloids, the use of radiation therapy for pediatric patients is less widely accepted because of concerns regarding secondary malignancy. The findings suggest additional studies need to be carried out to assess the risk of those complications.

A Regional Approach to Hospital-Based Violence Intervention Programs Through LOV.

CONTEXT: Community violence is an underaddressed public health threat. Hospital-based violence intervention programs (HVIPs) have been used to address the root causes of violence and prevent reinjury. OBJECTIVE: In this article, we describe the methodology of the St Louis Region-wide HVIP, Life Outside Violence (LOV) program, and provide preliminary process outcomes. DESIGN: Life Outside Violence mentors intervene following a violent injury to decrease risk of subsequent victimization and achieve goals unique to each participant by providing therapeutic counseling and case management services to patients and their families. PARTICIPANTS AND SETTING: Eligible patients are victims of violent injury between the ages of 8 and 24 years, who are residents of St Louis, Missouri, and present for care at a LOV partner adult or pediatric level I trauma hospital. INTERVENTION: Enrolled participants receive program services for 6 to 12 months and complete an individual treatment plan. MAIN OUTCOME MEASURES: In this article, we report LOV operational methodology, as well as process metrics, including program enrollment, graduation, and qualitative data on program implementation. RESULTS: From August 15, 2018, through April 30, 2022, 1750 LOV-eligible violently injured patients presented to a partner hospital, 349 were approached for program enrollment, and 206 consented to enroll in the program. During this pilot phase, 91 participants graduated from the LOV program and have process output data available for analysis. CONCLUSIONS: Life Outside Violence has been implemented into clinical practice as the first HVIP to influence across an entire region through partnership with multiple university and hospital systems. It is our hope that methods shared in this article will serve as a primer for organizations hoping to implement and expand HVIPs to interrupt community violence at the regional level.

Nirmatrelvir-ritonivir, COVID-19, and possible adverse cutaneous reactions.

Nirmatrelvir-ritonivir (Paxlovid) recently received emergency use authorization for the treatment of coronavirus disease 2019 (COVID-19). Literature has linked numerous cutaneous adverse effects to nirmatrelvir and ritonavir, the copackaged tablets within Paxlovid. A review and comparison of these adverse effects to the common cutaneous manifestations of COVID-19 is provided. Numerous drug-to-drug interactions exist between nirmatrelvir-ritonivir and commonly-used medications within dermatology.

Multi-institutional Validation of Improved Vesicoureteral Reflux Assessment With Simple and Machine Learning Approaches.

PURPOSE: Vesicoureteral reflux grading from voiding cystourethrograms is highly subjective with low reliability. We aimed to demonstrate improved reliability for vesicoureteral reflux grading with simple and machine learning approaches using ureteral tortuosity and dilatation on voiding cystourethrograms. MATERIALS AND METHODS: Voiding cystourethrograms were collected from our institution for training and 5 external data sets for validation. Each voiding cystourethrogram was graded by 5-7 raters to determine a consensus vesicoureteral reflux grade label and inter- and intra-rater reliability was assessed. Each voiding cystourethrogram was assessed for 4 features: ureteral tortuosity, proximal, distal, and maximum ureteral dilatation. The labels were then assigned to the combination of the 4 features. A machine learning-based model, qVUR, was trained to predict vesicoureteral reflux grade from these features and model performance was assessed by AUROC (area under the receiver-operator-characteristic). RESULTS: A total of 1,492 kidneys and ureters were collected from voiding cystourethrograms resulting in a total of 8,230 independent gradings. The internal inter-rater reliability for vesicoureteral reflux grading was 0.44 with a median percent agreement of 0.71 and low intra-rater reliability. Higher values for each feature were associated with higher vesicoureteral reflux grade. qVUR performed with an accuracy of 0.62 (AUROC=0.84) with stable performance across all external data sets. The model improved vesicoureteral reflux grade reliability by 3.6-fold compared to traditional grading (P < .001). CONCLUSIONS: In a large pediatric population from multiple institutions, we show that machine learning-based assessment for vesicoureteral reflux improves reliability compared to current grading methods. qVUR is generalizable and robust with similar accuracy to clinicians but the added prognostic value of quantitative measures warrants further study.

Linking out-of-hospital deaths with a regional hospital-based firearm injury database: a clinical researcher's guide to accessing data from the National Death Index.

IntroductionFirearm injuries are a public health crisis in the US. The National Death Index (NDI) is a well-established, comprehensive database managed by the National Center for Health Statistics at the CDC. In this methodology paper we describe our experience accessing and linking data from the NDI to our regional, hospital-based violent injury database to identify out-of-hospital deaths from firearms. METHODS: We outline the key steps of our submission to the NDI. Data were collected from research team meeting notes, team member emails with NDI staff, and information provided from the NDI website and supplementary guides. Few of our collaborators or university partner investigators had accessed or used data from the NDI. We discuss the online NDI Processing Portal data request, data preparation and receipt from the NDI, troubleshooting tips, and a timeline of events. RESULTS: Our query to the NDI returned 12 034 records of 12 219 firearm-injured patient records from 2010 and 2019. The record match rate was 98.5%. DISCUSSION: Linking hospital-based data sets with NDI data can provide valuable information on out-of-hospital deaths. This has the potential to improve the quality of longitudinal morbidity and mortality calculations in hospital-based patient cohorts. We encountered logistic and administrative challenges in completing the online NDI Processing Portal and in preparing and receiving data from the NDI. It is our hope that the lessons learnt presented herein will help facilitate easy and streamlined acquisition of valuable NDI data for other clinical researchers. WHAT THIS STUDY ADDS: - A step-by-step guide for clinical researchers of how to apply to access data from the National Death Index (NDI).- Advice and lessons learned on how to efficiently and effectively access data from the NDI.- A well-described methodology to improve the quality of longitudinal morbdity and mortality calculations in hospital-based cohorts of firearm injured patients.What is already known on this subject:- There is a need for robust, longitudinal data sources that reliably track morbidity and mortality among firearm injured patients in the United States.- The NDI is a well-established, comprehensive database that holds death records for all 50 states, which provides valuable mortality data to the public health and medical research community.

Procainamide for shockable rhythm cardiac arrest in the Resuscitation Outcome Consortium.

BACKGROUND: With recent negative studies of amiodarone and lidocaine for cardiac arrest, research into other antiarrhythmics is warranted. Literature on procainamide in cardiac arrest is limited. We evaluated procainamide for out-of-hospital cardiac arrests (OHCA) from the Resuscitation Outcomes Consortium (ROC). METHODS: We included all ROC Epistry 3 OHCAs with an initial shockable rhythm that received an antiarrhythmic. We stratified cases by antiarrhythmic: procainamide, amiodarone, or lidocaine. The outcomes were prehospital return of spontaneous circulation (ROSC), ROSC in the ED, and survival to hospital discharge. We defined propensity scores based on possible confounders utilizing 1:1 propensity score matching to compare procainamide to amiodarone and lidocaine. We analyzed the matched data using logistic regression. We also used multivariable logistic regression to evaluate the association between antiarrhythmic and outcomes. RESULTS: 3087 subjects met inclusion criteria; 51 patients received only procainamide, 1776 received amiodarone, and 1418 received lidocaine. On propensity score analysis and compared to procainamide, amiodarone had similar prehospital ROSC (OR 0.7, 95% CI 0.3-1.8), ED ROSC (OR 0.6, 95% CI 0.3-1.3), and survival (OR 1.0, 95% CI 0.3-3.1). Lidocaine also had a similar prehospital ROSC (OR 0.9, 95% CI 0.4-2.2), ED ROSC (OR 1.2, 95% CI 0.5-2.7), and survival (OR 1.4, 95% CI 0.5-4.0). However, using multivariable regression, amiodarone had lower prehospital ROSC than procainamide (aOR 0.3, 95% CI 0.1-0.6). CONCLUSIONS: While associated with increased prehospital ROSC when compared with amiodarone using multivariable regression, procainamide otherwise had similar prehospital ROSC, ED ROSC, and survival. The role of procainamide in OHCA remains unclear.

Methods for the solubilisation of membrane proteins: the micelle-aneous world of membrane protein solubilisation.

The solubilisation of membrane proteins (MPs) necessitates the overlap of two contradictory events; the extraction of MPs from their native lipid membranes and their subsequent stabilisation in aqueous environments. Whilst the current myriad of membrane mimetic systems provide a range of modus operandi, there are no golden rules for selecting the optimal pipeline for solubilisation of a specific MP hence a miscellaneous approach must be employed balancing both solubilisation efficiency and protein stability. In recent years, numerous diverse lipid membrane mimetic systems have been developed, expanding the pool of available solubilisation strategies. This review provides an overview of recent developments in the membrane mimetic field, with particular emphasis placed upon detergents, polymer-based nanodiscs and amphipols, highlighting the latest reagents to enter the toolbox of MP research.

Wilms tumor.

The objectives for the treatment of Wilms tumor in both the Children's Oncology Group (COG) and the International Society of Paediatric Oncology (SIOP) have focused on improving cure rates and minimizing toxicity by limiting the use of radiation and doxorubicin. Although the timing of surgery is different in COG (upfront surgery) and SIOP (upfront chemotherapy with delayed surgery), both are effective strategies and have the same survival. Fewer patients are treated with radiotherapy in the SIOP trials but with higher doses. The prognostic significance of biological markers such as 1q gain and clinical outcomes with novel radiation techniques such as intensity modulated radiation therapy will be determined in upcoming clinical trials. A closer collaboration between COG and SIOP could help promote research and improve the clinical outcomes of children with Wilms tumor.

Effect of Interpolated Questions on Podcast Knowledge Acquisition and Retention: A Double-Blind, Multicenter, Randomized Controlled Trial.

STUDY OBJECTIVE: We determine whether interpolated questions in a podcast improve knowledge acquisition and retention. METHODS: This double-blinded controlled trial randomized trainees from 6 emergency medicine programs to listen to 1 of 2 versions of a podcast, produced de novo on the history of hypertension. The versions were identical except that 1 included 5 interpolated questions to highlight educational points (intervention). There were 2 postpodcast assessments, 1 within 48 hours of listening (immediate posttest) and a second 2 to 3 weeks later (retention test), consisting of the same 15 multiple-choice questions, 5 directly related to the interpolated questions and 10 unrelated. The primary outcome was the difference in intergroup mean assessment scores at each point. A sample size was calculated a priori to identify a significant interarm difference. RESULTS: One hundred thirty-seven emergency medicine trainees were randomized to listen to a podcast, 69 without interpolated questions (control) and 68 with them (intervention). Although no significant difference was detected at the immediate posttest, trainees randomized to the interpolated arm had a significantly higher mean score on the retention test, with a 5.6% absolute difference (95% confidence interval 0.2% to 10.9%). For the material covered by the interpolated questions, the intervention arm had significantly higher mean scores on both the immediate posttest and retention tests, with absolute differences of 8.7% (95% confidence interval 1.6% to 15.8%) and 10.1% (95% confidence interval 2.8% to 17.4%), respectively. There was no significant intergroup difference for noninterpolated questions. CONCLUSION: Podcasts containing interpolated questions improved knowledge retention at 2 to 3 weeks, driven by the retention of material covered by the interpolated questions. Although the gains may be modest, educational podcasters may improve knowledge retention by using interpolating questions.

Drink, death, and driving: Do blood alcohol content limit reductions improve road safety?

This study exploits a natural experiment in Scotland where the legal blood alcohol content (BAC) limit was reduced from 0.8 to 0.5 mg per 100 ml of blood while staying constant in all other parts of the United Kingdom. Using a difference-in-differences design, we find that this change in the BAC level had no impact on either traffic accident or fatality rates.

Heterogeneous Presynaptic Distribution of Munc13 Isoforms at Retinal Synapses and Identification of an Unconventional Bipolar Cell Type with Dual Expression of Munc13 Isoforms: A Study Using Munc13-EXFP Knock-in Mice.

Munc13 isoforms are constituents of the presynaptic compartment of chemical synapses, where they govern important steps in preparing synaptic vesicles for exocytosis. The role of Munc13-1, -2 and -3 is well documented in brain neurons, but less is known about their function and distribution among the neurons of the retina and their conventional and ribbon-type chemical synapses. Here, we examined the retinae of Munc13-1-, -2-, and -3-EXFP knock-in (KI) mice with a combination of immunocytochemistry, physiology, and electron microscopy. We show that knock-in of Munc13-EXFP fusion proteins did not affect overall retinal anatomy or synapse structure, but slightly affected synaptic transmission. By labeling Munc13-EXFP KI retinae with specific antibodies against Munc13-1, -2 and -3, we found that unlike in the brain, most retinal synapses seem to operate with a single Munc13 isoform. A surprising exception to this rule was type 6 ON bipolar cells, which expressed two Munc13 isoforms in their synaptic terminals, ubMunc13-2 and Munc13-3. The results of this study provide an important basis for future studies on the contribution of Munc13 isoforms in visual signal processing in the mammalian retina.