Expanded MutaT7 toolkit efficiently and simultaneously accesses all possible transition mutations in bacteria.

Targeted mutagenesis mediated by nucleotide base deaminase-T7 RNA polymerase fusions has recently emerged as a novel and broadly useful strategy to power genetic diversification in the context of in vivo directed evolution campaigns. Here, we expand the utility of this approach by introducing a highly active adenosine deaminase-T7 RNA polymerase fusion protein (eMutaT7A→G), resulting in higher mutation frequencies to enable more rapid directed evolution. We also assess the benefits and potential downsides of using this more active mutator. We go on to show in Escherichia coli that adenosine deaminase-bearing mutators (MutaT7A→G or eMutaT7A→G) can be employed in tandem with a cytidine deaminase-bearing mutator (MutaT7C→T) to introduce all possible transition mutations simultaneously. We illustrate the efficacy of this in vivo mutagenesis approach by exploring mutational routes to antibacterial drug resistance. This work sets the stage for general application of optimized MutaT7 tools able to induce all types of transition mutations during in vivo directed evolution campaigns across diverse organisms.

Correlation of Scholarly Activity and Departmental Clinical Productivity in a Surgical Subspecialty.

INTRODUCTION: Promotion within academic surgery involves demonstrated excellence in administrative, clinical, and scholarly activities. The present study analyzes the relationship between scholarly and clinical productivity in the field of reconstructive microsurgery. METHODS: This is a retrospective cohort study of microsurgery fellowship directors (MFDs). Data on clinical productivity were obtained from the American Society for Reconstructive Microsurgery and scholarly productivity from Scopus. Outcomes were department annual free flap volume, number of publications, and h-index. Descriptive statistics were calculated, and nonparametric tests were used to compare continuous variables. RESULTS: Thirty-nine MFDs were included in this study. All were plastic surgery residency trained and 38% trained under the independent training pathway. Most underwent formal fellowship training in reconstructive microsurgery (89%). The top three microsurgery fellowships trained 37% of all MFDs. Twenty-five percent of MFDs trained at the institution where they ultimately became program director. Twenty percent of MFDs had an additional degree (4 MS, 2 PhD, and 1 MBA). The median number of annual free flaps performed per institution was 175 (interquartile range [IQR] 122). The median h-index was 17 (IQR 13) resulting from 48 (IQR 99) publications. There was a correlation between department annual free flap volume and h-index (r = 0.333, P = 0.038). CONCLUSIONS: There is a correlation between academic productivity of MFDs and the clinical productivity of their department. This study provides a benchmark for aspiring reconstructive microsurgeons.

Cortical Anoxic Spreading Depolarization During Cardiac Arrest is Associated with Remote Effects on Peripheral Blood Pressure and Postresuscitation Neurological Outcome.

BACKGROUND: Spreading depolarizations (SDs) are self-propagating waves of neuronal and glial depolarizations often seen in neurological conditions in both humans and animal models. Because SD is thought to worsen neurological injury, the role of SD in a variety of cerebral insults has garnered significant investigation. Anoxic SD is a type of SD that occurs because of anoxia or asphyxia. Although asphyxia leading to a severe drop in blood pressure may affect cerebral hemodynamics and is widely known to cause anoxic SD, the effect of anoxic SD on peripheral blood pressure in the extremities has not been investigated. This relationship is especially important to understand for conditions such as circulatory shock and cardiac arrest that directly affect both peripheral and cerebral perfusion in addition to producing anoxic SD in the brain. METHODS: In this study, we used a rat model of asphyxial cardiac arrest to investigate the role of anoxic SD on cerebral hemodynamics and metabolism, peripheral blood pressure, and the relationship between these variables in 8- to 12-week-old male rats. We incorporated a multimodal monitoring platform measuring cortical direct current simultaneously with optical imaging. RESULTS: We found that during anoxic SD, there is decoupling of peripheral blood pressure from cerebral blood flow and metabolism. We also observed that anoxic SD may modify cerebrovascular resistance. Furthermore, shorter time difference between anoxic SDs measured at different locations in the same rat was associated with better neurological outcome on the basis of the recovery of electrocorticography activity (bursting) immediately post resuscitation and the neurological deficit scale score 24 h post resuscitation. CONCLUSIONS: To our knowledge, this is the first study to quantify the relationship between peripheral blood pressure, cerebral hemodynamics and metabolism, and neurological outcome in anoxic SD. These results indicate that the characteristics of SD may not be limited to cerebral hemodynamics and metabolism but rather may also encompass changes in peripheral blood flow, possibly through a brain-heart connection, providing new insights into the role of anoxic SD in global ischemia and recovery.

Charting Outcomes in the Hand Surgery Fellowship Match.

PURPOSE: The hand surgery fellowship match attracts applicants from general, plastic, and orthopedic surgery residency training. The purpose of this study was to understand recent trends in applications and match rates in the hand surgery fellowship match. METHODS: The National Resident Matching Program provided program and applicant data from the hand surgery fellowship match (2012-2020). The primary outcomes of interest were match rates and number of unfilled fellowship positions by specialty. Trends over time and comparisons of the percentage of unfilled spots by specialty were observed. RESULTS: The total number of applicants decreased from 199 to 188 (5.5% decrease), while the number of available positions increased from 150 to 177 (18.0% increase) during the study period. The increase in available positions was driven primarily by orthopedic fellowships, which increased from 124 to 149 (20.2% increase). The percentage of applicants that did not match to a hand surgery fellowship decreased from 24.6% in 2012 to 5.9% in 2020. United States graduates had higher match rates than non-United States graduates during each year, but this disparity narrowed over time. Most applicants matched at one of their top 3 choices (first choice, 33.3%; second choice, 12.9%; third choice, 7.9%). Applicants matching at their first choice increased from 28.1% in 2012 to 39.4% in 2020. Plastic surgery hand surgery fellowships had a higher rate of unmatched positions relative to orthopedic surgery fellowships (6.1% vs 2.2%). CONCLUSIONS: Match rates in the hand surgery fellowship match have increased because of an overall increase in training positions and decrease in applicants. More research is needed to understand disparities in match rates by specialty. CLINICAL RELEVANCE: The diverse training experiences of hand surgeons historically have been viewed as a strength for the specialty. Understanding recent trends in the hand surgery fellowship match by specialty can help future applicants and faculty anticipate likely match outcomes.

The Role of Body Mass Index in Perioperative Complications Among Patients Undergoing Total Knee Arthroplasty.

Obesity is a modifiable risk factor that causes mechanical forces to be exerted within the joints, further contributing to the debilitating effects of osteoarthritis. Total Knee Arthroplasty (TKA) can have a profound impact on patients with osteoarthritis, providing them with increased quality of life, improved function, reduction of pain, while simultaneously preventing the development of additional comorbidities. Although there is inconclusive evidence that increased body mass index (BMI) is linked to increased perioperative complications among TKA patients, recent studies suggest this association exists. The aim of this study is to provide conclusive data on the effects of BMI on perioperative complications in TKA using the national risk-adjusted database, ACS-NSQIP. Our study demonstrated that there was a correlation between increased BMI and perioperative outcomes, particularly with surgical site infections, renal, and respiratory complications. (Journal of Surgical Orthopaedic Advances 29(4):205-208, 2020).

An improved Escherichia coli screen for Rubisco identifies a protein-protein interface that can enhance CO2-fixation kinetics.

An overarching goal of photosynthesis research is to identify how components of the process can be improved to benefit crop productivity, global food security, and renewable energy storage. Improving carbon fixation has mostly focused on enhancing the CO2 fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). This grand challenge has mostly proved ineffective because of catalytic mechanism constraints and required chaperone complementarity that hinder Rubisco biogenesis in alternative hosts. Here we refashion Escherichia coli metabolism by expressing a phosphoribulokinase-neomycin phosphotransferase fusion protein to produce a high-fidelity, high-throughput Rubisco-directed evolution (RDE2) screen that negates false-positive selection. Successive evolution rounds using the plant-like Te-Rubisco from the cyanobacterium Thermosynechococcus elongatus BP1 identified two large subunit and six small subunit mutations that improved carboxylation rate, efficiency, and specificity. Structural analysis revealed the amino acids clustered in an unexplored subunit interface of the holoenzyme. To study its effect on plant growth, the Te-Rubisco was transformed into tobacco by chloroplast transformation. As previously seen for Synechocccus PCC6301 Rubisco, the specialized folding and assembly requirements of Te-Rubisco hinder its heterologous expression in leaf chloroplasts. Our findings suggest that the ongoing efforts to improve crop photosynthesis by integrating components of a cyanobacteria CO2-concentrating mechanism will necessitate co-introduction of the ancillary molecular components required for Rubisco biogenesis.

Complex Chaperone Dependence of Rubisco Biogenesis.

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), a ∼530 kDa complex of 8 large (RbcL) and 8 small subunits (RbcS), mediates the fixation of atmospheric CO2 into usable sugars during photosynthesis. Despite its fundamental role, Rubisco is a remarkably inefficient enzyme and thus is produced by plants in huge amounts. It has long been a key target for bioengineering with the goal to increase crop yields. However, such efforts have been hampered by the complex requirement of Rubisco biogenesis for molecular chaperones. Recent studies have identified an array of auxiliary factors needed for the folding and assembly of the Rubisco subunits. The folding of plant RbcL subunits is mediated by the cylindrical chloroplast chaperonin, Cpn60, and its cofactor Cpn20. Folded RbcL requires a number of additional Rubisco specific assembly chaperones, including RbcX, Rubisco accumulation factors 1 (Raf1) and 2 (Raf2), and the Bundle sheath defective-2 (BSD2), to mediate the assembly of the RbcL8 intermediate complex. Incorporation of the RbcS and displacement of the assembly factors generates the active holoenzyme. An Escherichia coli strain expressing the chloroplast chaperonin and auxiliary factors now allows the expression of functional plant Rubisco, paving the way for Rubisco engineering by large scale mutagenesis. Here, we review our current understanding on how these chaperones cooperate to produce one of the most important enzymes in nature.

Musculoskeletal Manifestations of Amyloidosis: A Focused Review.

Amyloidosis is a poorly understood condition that can wreak havoc on numerous systems within the human body. In addition, this disease can present in multiple forms which each have their own unique physiology and subsequent effects. However, while the literature on the etiology and effect of amyloidosis on various organ systems is numerous, few have highlighted the musculoskeletal manifestations of this devastating disease. This review focuses on the recent research on amyloid deposition in the musculoskeletal system. Additionally, risk factors, classification, differential diagnoses, indications for biopsy, and manifestations of amyloidosis in the musculoskeletal system as well as in other tissues are discussed. Furthermore, the surgical and nonsurgical approaches to treatment are covered. (Journal of Surgical Orthopaedic Advances 27(1):1-5, 2018).

Real-Time Characterization of Diminutive Colorectal Polyp Histology Using Narrow-Band Imaging: Implications for the Resect and Discard Strategy.

BACKGROUND & AIMS: Narrow-band imaging (NBI) allows real-time histologic classification of colorectal polyps. We investigated whether endoscopists without prior training in NBI can achieve the following thresholds recommended by the American Society for Gastrointestinal Endoscopy: for diminutive colorectal polyps characterized with high confidence, a ≥90% negative predictive value for adenomas in the rectosigmoid and a ≥90% agreement in surveillance intervals. METHODS: Twenty-six endoscopists from 2 tertiary care centers underwent standardized training in NBI interpretation. Endoscopists made real-time predictions of diminutive colorectal polyp histology and surveillance interval predictions based on NBI. Their performance was evaluated by comparing predicted with actual findings from histologic analysis. Multilevel logistic regression was used to assess predictors of performance. Cumulative summation analysis was used to characterize learning curves. RESULTS: The endoscopists performed 1451 colonoscopies and made 3012 diminutive polyp predictions (74.3% high confidence) using NBI. They made 898 immediate post-procedure surveillance interval predictions. An additional 505 surveillance intervals were determined with histology input. The overall negative predictive value for high-confidence characterizations in the rectosigmoid was 94.7% (95% confidence interval: 92.6%-96.8%) and the surveillance interval agreement was 91.2% (95% confidence interval: 89.7%-92.7%). Overall, 97.0% of surveillance interval predictions would have brought patients back on time or early. High-confidence characterization was the strongest predictor of accuracy (odds ratio = 3.42; 95% confidence interval: 2.72-4.29; P < .001). Performance improved over time, however, according to cumulative summation analysis, only 7 participants (26.9%) identified adenomas with sufficient sensitivity such that further auditing is not required. CONCLUSIONS: With standardized training, gastroenterologists without prior expertise in NBI were able to meet the negative predictive value and surveillance interval thresholds set forth by the American Society for Gastrointestinal Endoscopy. The majority of disagreement in surveillance interval brought patients back early. Performance improves with time, but most endoscopists will require ongoing auditing of performance. ClinicalTrials.gov ID NCT02441998.

Increasing Number of Passes Beyond 4 Does Not Increase Sensitivity of Detection of Pancreatic Malignancy by Endoscopic Ultrasound-Guided Fine-Needle Aspiration.

BACKGROUND & AIMS: It is not clear exactly how many passes are required to determine whether pancreatic masses are malignant using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). We aimed to define the per-pass diagnostic yield of EUS-FNA for establishing the malignancy of a pancreatic mass, and identify factors associated with detection of malignancies. METHODS: In a prospective study, 239 patients with solid pancreatic masses were randomly assigned to groups that underwent EUS-FNA, with the number of passes determined by an on-site cytopathology evaluation or set at 7 passes, at 3 tertiary referral centers. A final diagnosis of pancreatic malignancy was made based on findings from cytology, surgery, or a follow-up evaluation at least 1 year after EUS-FNA. The cumulative sensitivity of detection of malignancy by EUS-FNA was calculated after each pass; in the primary analysis, lesions categorized as malignant or suspicious were considered as positive findings. RESULTS: Pancreatic malignancies were found in 202 patients (84.5% of the study population). EUS-FNA detected malignancies with 96% sensitivity (95% confidence interval [CI], 92%-98%); 4 passes of EUS-FNA detected malignancies with 92% sensitivity (95% CI, 87%-95%). Tumor size greater than 2 cm was the only variable associated with positive results from cytology analysis (odds ratio, 7.8; 95% CI, 1.9-31.6). In masses larger than 2 cm, 4 passes of EUS-FNA detected malignancies with 93% sensitivity (95% CI, 89%-96%) and in masses ≤2 cm, 6 passes was associated with 82% sensitivity (95% CI, 61%-93%). Sensitivity of detection did not increase with increasing number of passes. CONCLUSIONS: In a prospective study, we found 4 passes of EUS-FNA to be sufficient to detect malignant pancreatic masses; increasing the number of passes did not increase the sensitivity of detection. Tumor size greater than 2 cm was associated with malignancy, and a greater number of passes may be required to evaluate masses 2 cm or less. ClinicalTrials.gov number, NCT01386931.

A Prospective Multicenter Study Evaluating Learning Curves and Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography Among Advanced Endoscopy Trainees: The Rapid Assessment of Trainee Endoscopy Skills Study.

BACKGROUND & AIMS: On the basis of the Next Accreditation System, trainee assessment should occur on a continuous basis with individualized feedback. We aimed to validate endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) learning curves among advanced endoscopy trainees (AETs) by using a large national sample of training programs and to develop a centralized database that allows assessment of performance in relation to peers. METHODS: ASGE recognized training programs were invited to participate, and AETs were graded on ERCP and EUS exams by using a validated competency assessment tool that assesses technical and cognitive competence in a continuous fashion. Grading for each skill was done by using a 4-point scoring system, and a comprehensive data collection and reporting system was built to create learning curves by using cumulative sum analysis. Individual results and benchmarking to peers were shared with AETs and trainers quarterly. RESULTS: Of the 62 programs invited, 20 programs and 22 AETs participated in this study. At the end of training, median number of EUS and ERCP performed/AET was 300 (range, 155-650) and 350 (125-500), respectively. Overall, 3786 exams were graded (EUS, 1137; ERCP-biliary, 2280; ERCP-pancreatic, 369). Learning curves for individual end points and overall technical/cognitive aspects in EUS and ERCP demonstrated substantial variability and were successfully shared with all programs. The majority of trainees achieved overall technical (EUS, 82%; ERCP, 60%) and cognitive (EUS, 76%; ERCP, 100%) competence at conclusion of training. CONCLUSIONS: These results demonstrate the feasibility of establishing a centralized database to report individualized learning curves and confirm the substantial variability in time to achieve competence among AETs in EUS and ERCP. ClinicalTrials.gov: NCT02509416.

Benchmarking Accomplishments of Presidents Elected to Hand Surgery Societies in the United States.

Objective: Qualifications needed to achieve national leadership positions in hand surgery are poorly defined. This study compares the academic accomplishments, demographics, and training backgrounds of presidents elected to serve the American Society for Surgery of the Hand (ASSH) and the American Association for Hand Surgery (AAHS). Methods: The ASSH and AAHS provided names of elected Presidents (1990-2022, n = 64). Curriculum vitae and academic web sites were used to collect demographic, training, bibliometric, and National Institutes of Health (NIH) funding data of presidents. Results: Presidents were predominately male (95%), Caucasian (90%), and orthopaedic surgery residency-trained (66%). Only 9% were racial minorities (8% Asian, 2% Hispanic, and 0% African American). The average age at appointment was 59 ± 7 years old, which was an average of 23 years from completion of hand surgery fellowship. More presidents received plastic surgery residency training in AAHS than ASSH (50 vs. 19%). The most represented hand surgery fellowships were Mayo Clinic (14%), University of Louisville (11%), and Duke University (9%). Twenty-one presidents participated in a travel fellowship (33%). Thirty presidents served as Department Chair or Division Chief at time of election (47%). The average h-index was 34 ± 18 resulting from 164 ± 160 peer-reviewed manuscripts and was similar between the two organizations. Eleven presidents had NIH grant funding (18%) and there were no differences in procurement or funding totals between the two organizations. Conclusion: Presidents of American hand surgery societies obtain high levels of scholarly activity regardless of training specialty. Women and racial minorities remain underrepresented at the highest levels of leadership.

Impact of Orthopedic Hand Surgery Fellowship Training on Hand Surgery Cases Performed by Plastic Surgeons in the United States.

Objective: Multiple pathways exist for hand surgery training in the United States. Plastic surgeons often select Orthopedic Hand Surgery Fellowships to complement their skills and bridge perceived deficiencies in bone and joint cases. This study aims to quantify the impact of this approach on operative hand experience. Materials and methods: Case logs were analyzed for plastic surgery residents and orthopaedic hand surgery fellows (2016-2017 to 2019-2020). Reported hand surgery cases were compared between residency and fellowship using Student's t-tests. In total, 606 plastic surgery residents and 393 orthopaedic hand surgery fellows were included in this study. One year of Orthopedic Hand Surgery Fellowship training afforded more than twice the volume of hand surgery cases than Plastic Surgery Residency training (886.1 ± 234.7 vs. 428.1 ± 147.2, p < 0.001). Results: Case categories with the greatest positive fold difference in case volume encountered during Orthopedic Surgery Hand Fellowship were tumor (138.2 ± 63.2 vs. 22.1 ± 11.8, p < 0.001), joint reconstruction (108.7 ± 21.6 vs. 18.8 ± 11.5, p < 0.001), nerve decompression (158.4 ± 63.1 vs. 53.0 ± 32.6, p < 0.001), Dupuytren's (18.4 ± 10.5 vs. 7.6 ± 6.4, p < 0.001), and fracture management (132.8 ± 21.7 vs. 59.6 ± 24.1, p < 0.001). Conclusion: Orthopedic Hand Surgery Fellowship training doubles the operative hand case volume encountered during Plastic Surgery Residency. Significant increases are especially encountered for select case categories including bone and joint cases.

Differences in Academic Qualifications for Leadership at Hand Surgery Fellowships in the United States.

Objective: In the United States, orthopaedic, general, and plastic surgery hand fellowship programs train hand surgeons. Currently, differences in the academic qualifications of hand surgery fellowship directors (HSFDs) are unknown. This study compares the academic qualifications of HSFDs by specialty. Methods: American Medical Association's Residency and Fellowship Database was queried for hand surgery fellowship training programs. Scholarly activity, academic characteristics, and training pedigrees were collected for each HSFD. Results: Ninety-two HSFDs (73 orthopaedic surgeons, 17 plastic surgeons, 2 general surgeons) were identified. Most were male (87%) and Caucasian (82%). Mean age was 55 ± 11 years and most were trained in orthopaedic surgery (80%). Ten percent of orthopaedic hand surgery fellowship programs were run by a plastic surgeon HSFD, which was greater than 0% of plastic surgery hand fellowship programs run by an orthopaedic surgeon HSFD (p < 0.05). Mean H-index was 15 ± 9 from an average of 57 ± 47 publications. Orthopaedic and plastic surgeon HSFDs had similar levels of scholarly activity (p > 0.05). Age correlated with higher H-index values (r = 0.38, p < 0.001). More plastic surgeon HSFDs were trained by their top five fellowship programs than orthopaedic surgeon HSFDs (65 vs. 27%, p < 0.05). Conclusion: Ultimately, HSFDs have strong research backgrounds and similar characteristics despite disparate training pathways. Women and racial minority groups are largely underrepresented among leadership positions at hand surgery fellowships. These benchmarks can help inform future diversity initiatives.

Review of machine learning for optical imaging of burn wound severity assessment.

Significance: Over the past decade, machine learning (ML) algorithms have rapidly become much more widespread for numerous biomedical applications, including the diagnosis and categorization of disease and injury. Aim: Here, we seek to characterize the recent growth of ML techniques that use imaging data to classify burn wound severity and report on the accuracies of different approaches. Approach: To this end, we present a comprehensive literature review of preclinical and clinical studies using ML techniques to classify the severity of burn wounds. Results: The majority of these reports used digital color photographs as input data to the classification algorithms, but recently there has been an increasing prevalence of the use of ML approaches using input data from more advanced optical imaging modalities (e.g., multispectral and hyperspectral imaging, optical coherence tomography), in addition to multimodal techniques. The classification accuracy of the different methods is reported; it typically ranges from ∼70% to 90% relative to the current gold standard of clinical judgment. Conclusions: The field would benefit from systematic analysis of the effects of different input data modalities, training/testing sets, and ML classifiers on the reported accuracy. Despite this current limitation, ML-based algorithms show significant promise for assisting in objectively classifying burn wound severity.

A Rare Presentation of Plexiform Schwannoma of the Thumb.

Plexiform schwannomas are rare, benign, neural crest-derived tumors that commonly occur in the hand and upper extremities. They may be sporadic or associated with neurofibromatosis type 2. Although previous literature has described plexiform schwannomas occurring in fingers, nerve and tendon sheaths, and intraosseous lesions, this is the first known case of a plexiform schwannoma of the thumb. This is a case of a growing, painless, subungual mass of the thumb in a 54-year-old patient. After surgical excision and subsequent immunohistochemical examination, the patient was diagnosed with a plexiform schwannoma. This highlights the importance of maintenance a broad differential before surgery and obtaining a proper diagnosis using histopathology.

Assessing Trends in Supply and Demand for Pediatric Surgery Training.

OBJECTIVE: This study assessed the supply and demand for Pediatric Surgery training in the U.S. from 2008 to 2022. We hypothesized that in the Pediatric Surgery Match: match rates would increase over time; U.S. MD Graduates would have higher match rates than non-U.S. MD Graduates; and fewer applicants would match at one of their top fellowship choices. DESIGN: This was a retrospective cohort study of Pediatric Surgery Match applicants (2008-2022). Cochran-Armitage tests elucidated temporal trends and chi square tests compared outcomes by applicant archetype. SETTING: Accreditation Council for Graduate Medical Education (ACGME)-accredited Pediatric Surgery training programs in the United States and non-ACGME-accredited programs in Canada. PARTICIPANTS: A total of 1,133 applicants for Pediatric Surgery training. RESULTS: From 2008 to 2012, growth in the annual number of fellowship positions (34-43, 27% increase) exceeded growth in number of applicants (62-69, 11% increase) (p < 0.001). Over the study period, the applicant-to-training ratio peaked at 2.1 to 2.2 in 2017 to 2018 and decreased to 1.4 to 1.6 in 2021 to 2022. The annual match rate for U.S. MD Graduates increased from 60% to 68% (p < 0.05), but decreased from 40% to 22% (p < 0.05) for non-U.S. MD Graduates. In 2022, there was a 3.1-fold difference in match rates between U.S. MD and non-U.S. MD Graduates (68% vs 22%, p < 0.001). The percentage of applicants that matched at their first choice (25%-20%, p < 0.001), second choice (11%-4%, p < 0.001), and third choice (7%-4%, p < 0.001) fellowships decreased over the study period. The percentage of applicants that matched at their fourth choice to least desirable fellowship increased from 23% to 33% (p < 0.001). CONCLUSIONS: The demand for Pediatric Surgery training peaked in 2017 to 2018 and has decreased since. However, the Pediatric Surgery Match remains competitive especially for non-U.S. MD Graduates. More research is needed to understand barriers to matching into Pediatric Surgery for non-U.S. MD Graduates.

The Impact of Post-graduate Year and Program Accreditation Status on In-Training Examination Performance in Orthopaedic Surgery.

Introduction  The progression of medical knowledge competency during surgical residency training is poorly understood. This study measures the acquisition of medical knowledge as orthopedic surgery residents advance during training and the impact of accreditation status on orthopedic in-training examination (OITE) performance. Methods  Orthopedic surgery residents taking the OITE during 2020 and 2021 were included. Residents were grouped into cohorts by post-graduate year (PGY) and Accreditation Council for Graduate Medical Education (ACGME) accreditation status. Comparisons were made with parametric tests. Results  Eight thousand eight hundred and seventy-one ACGME-accredited residents (89%) and 1,057 non-ACGME-accredited residents (11%) were evenly distributed by the PGY level (range, 19-21%). Residents in both ACGME- and non-ACGME-accredited residency programs had a significant increase in OITE performance at each PGY level (P<0.001). At ACGME-accredited programs, OITE performance increased from PGY1 (51%), PGY2 (59%), PGY3 (65%), PGY4 (68%), and PGY5 (70%) (P<0.001). There were progressively smaller percentage increases in OITE performance during accredited residency training (range, 2-8%), but this increase was linear in non-accredited residency training (range, 4%). At each PGY level, residents at accredited programs outperformed their counterparts at non-accredited programs (P<0.001). Conclusion OITE performance increases during residency training. Among ACGME-accredited residents, performance on the OITE progresses rapidly during junior years and plateaus during senior years. Residents in ACGME-accredited residency programs outperform their counterparts in non-accredited residency programs. More research is needed to understand optimal training environments that promote medical knowledge acquisition during orthopedic surgery residency.

Intrinsic, widefield optical imaging of hemodynamics in rodent models of Alzheimer's disease and neurological injury.

The complex cerebrovascular network is critical to controlling local cerebral blood flow (CBF) and maintaining brain homeostasis. Alzheimer's disease (AD) and neurological injury can result in impaired CBF regulation, blood-brain barrier breakdown, neurovascular dysregulation, and ultimately impaired brain homeostasis. Measuring cortical hemodynamic changes in rodents can help elucidate the complex physiological dynamics that occur in AD and neurological injury. Widefield optical imaging approaches can measure hemodynamic information, such as CBF and oxygenation. These measurements can be performed over fields of view that range from millimeters to centimeters and probe up to the first few millimeters of rodent brain tissue. We discuss the principles and applications of three widefield optical imaging approaches that can measure cerebral hemodynamics: (1) optical intrinsic signal imaging, (2) laser speckle imaging, and (3) spatial frequency domain imaging. Future work in advancing widefield optical imaging approaches and employing multimodal instrumentation can enrich hemodynamic information content and help elucidate cerebrovascular mechanisms that lead to the development of therapeutic agents for AD and neurological injury.

Variability in procedure volume of physical medicine and rehabilitation residents graduating from 2014 to 2021.

BACKGROUND: Adequate exposure to commonly performed procedures during physical medicine and rehabilitation (PM&R) residency is an important issue. OBJECTIVE: To assess temporal trends and variabilities in reported procedural volumes, including the number of residents achieving procedure minimum requirements as established by the Accredited Council for Graduate Medical Education (ACGME) PM&R Residency Review Committee. DESIGN: This was a retrospective cohort study of PM&R residents graduating from 2013-2014 to 2020-2021. Descriptive statistics were calculated for tracked procedures and compared over time with analysis of variance (ANOVA) tests. Variability was calculated as the procedure volume difference between the 90th and 10th percentile groups. SETTING: ACGME-accredited PM&R residency training programs. PARTICIPANTS: A total of 3231 PM&R residents graduating from 2014 to 2021. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Reported procedure volume and number of residents achieving minimum requirements. RESULTS: Total procedure volume increased over the study period (436 ± 225 to 523 ± 238, p = .013). The percentage of all procedures that were performed versus observed was stable over the study period (81%-77%, p = .234). Variability in total reported procedure volume remained stable over the study period. The percentage of PM&R residents not achieving minimum requirements ranged from 2% for peripheral joint injections to 22% for ultrasound in the contemporary training period. CONCLUSIONS: The volume of reported procedures has increased along with the number of PM&R residency programs and residents. Variabilities in total reported procedure volume were stable over time, but PM&R residents struggle to obtain minimum requirements for ultrasound procedures.