Shieldin and CST co-orchestrate DNA polymerase-dependent tailed-end joining reactions independently of 53BP1-governed repair pathway choice.

Tumor suppressor p53-binding protein 1 (53BP1) regulates DNA end joining in lymphocytes, diversifying immune antigen receptors. This involves nucleosome-bound 53BP1 at DNA double-stranded breaks (DSBs) recruiting Rap1-interacting factor 1 homolog (RIF1) and shieldin, a poorly understood DNA-binding complex. The 53BP1-RIF1-shieldin axis is pathological in BRCA1-mutated cancers, blocking homologous recombination (HR) and driving illegitimate nonhomologous end joining (NHEJ). However, how this axis regulates DNA end joining and HR suppression remains unresolved. We investigated shieldin and its interplay with the Ctc1-Stn1-Ten1 (CST) complex, which was recently implicated downstream of 53BP1. Immunophenotypically, mice lacking shieldin or CST are equivalent, with class-switch recombination coreliant on both complexes. Ataxia-telangiectasia mutated kinase-dependent DNA damage signaling underpins this cooperation, inducing physical interactions between these complexes that reveal shieldin as a DSB-responsive CST adaptor. Furthermore, DNA polymerase ζ functions downstream of shieldin, establishing DNA fill-in synthesis as the physiological function of shieldin-CST. Lastly, we demonstrate that 53BP1 suppresses HR and promotes NHEJ in BRCA1-deficient mice and cells independently of shieldin. These findings showcase the versatility of the 53BP1 pathway, achieved through the collaboration of chromatin-bound 53BP1 complexes and DNA end-processing effector proteins.

Laparoscopy experience in East, Central, and Southern Africa: insights from operative case volume analysis.

BACKGROUND: With the primary objective of addressing the disparity in global surgical care access, the College of Surgeons of East, Central, and Southern Africa (COSECSA) trains surgeons. While sufficient operative experience is crucial for surgical training, the extent of utilization of minimally invasive techniques during COSECSA training remains understudied. METHODS: We conducted an extensive review of COSECSA general surgery trainees' operative case logs from January 1, 2015, to December 31, 2020, focusing on the utilization of minimally invasive surgical procedures. Our primary objective was to determine the prevalence of laparoscopic procedures and compare this to open procedures. We analyzed the distribution of laparoscopic cases across common indications such as cholecystectomy, appendicitis, and hernia operations. Additionally, we examined the impact of trainee autonomy, country development index, and hospital type on laparoscopy utilization. RESULTS: Among 68,659 total cases, only 616 (0.9%) were laparoscopic procedures. Notably, 34 cases were conducted during trainee external rotations in countries like the United Kingdom, Germany, and India. Gallbladder and appendix pathologies were most frequent among the 582 recorded laparoscopic cases performed in Africa. Laparoscopic cholecystectomy accounted for 29% (276 of 975 cases), laparoscopic appendectomy for 3% (76 of 2548 cases), and laparoscopic hernia repairs for 0.5% (26 of 5620 cases). Trainees self-reported lower autonomy for laparoscopic (22.5%) than open cases (61.5%). Laparoscopy usage was more prevalent in upper-middle-income (2.7%) and lower-middle-income countries (0.8%) compared with lower-income countries (0.5%) (p < 0.001). Private (1.6%) and faith-based hospitals (1.5%) showed greater laparoscopy utilization than public hospitals (0.5%) (p < 0.001). CONCLUSIONS: The study highlights the relatively low utilization of minimally invasive techniques in surgical training within the ECSA region. Laparoscopic cases remain a minority, with variations observed based on specific diagnoses. The findings suggest a need to enhance exposure to minimally invasive procedures to ensure well-rounded training and proficiency in these techniques.

MARS an improved de novo peptide candidate selection method for non-canonical antigen target discovery in cancer.

Understanding the nature and extent of non-canonical human leukocyte antigen (HLA) presentation in tumour cells is a priority for target antigen discovery for the development of next generation immunotherapies in cancer. We here employ a de novo mass spectrometric sequencing approach with a refined, MHC-centric analysis strategy to detect non-canonical MHC-associated peptides specific to cancer without any prior knowledge of the target sequence from genomic or RNA sequencing data. Our strategy integrates MHC binding rank, Average local confidence scores, and peptide Retention time prediction for improved de novo candidate Selection; culminating in the machine learning model MARS. We benchmark our model on a large synthetic peptide library dataset and reanalysis of a published dataset of high-quality non-canonical MHC-associated peptide identifications in human cancer. We achieve almost 2-fold improvement for high quality spectral assignments in comparison to de novo sequencing alone with an estimated accuracy of above 85.7% when integrated with a stepwise peptide sequence mapping strategy. Finally, we utilize MARS to detect and validate lncRNA-derived peptides in human cervical tumour resections, demonstrating its suitability to discover novel, immunogenic, non-canonical peptide sequences in primary tumour tissue.

Gender Disparities in Complications, Costs, and Mortality After Emergency Gastrointestinal Surgery in Kenya.

INTRODUCTION: Little is known about the impact of gender on emergency surgery within Kenya. Therefore, we aimed to investigate the association of gender on outcomes of postoperative complications, health care costs, and mortality. METHODS: We evaluated an established cohort of patients undergoing emergency gastrointestinal surgery in rural Kenya between January 1st, 2016 and June 30th, 2019. Utilizing logistic regression, we examined the association between self-reported patient gender and the outcomes of postoperative complications and mortality. A generalized linear model was created for total hospital costs, inflation-adjusted in international dollars purchasing power parity, to examine the impact of gender. Confounding factors were controlled by Africa Surgical Outcomes Study Surgical Risk Score. RESULTS: Among 484 patients reviewed, 149 (30.8%) were women. 165 (34.1%) patients developed complications, with women experiencing more than men (40.9% versus 31.0%; P = 0.03) and longer hospital stays (median 6 days (4-9) versus 5 (4-7); P = 0.02). After controlling for Africa Surgical Outcomes Study Surgical Risk Score, odds of developing complications for women were 1.67 (95% confidence interval: 1.09-2.55; P = 0.019) times higher than men, and the odds of death were 2.38 (95% confidence interval: 1.12-5.09; P = 0.025) times greater for women than men, despite similar failure-to-rescue rates and intensive care unit utilization. Total hospital costs were increased for women by 531 international dollars purchasing power parity (117-946; P = 0.012) when compared to men, attributed to longer lengths of stay. CONCLUSIONS: These findings demonstrate that a discrepancy exists between men and women undergoing emergency gastrointestinal surgery in our setting. Further exploration of the underlying causes of this inequity is necessary for quality improvement for women in rural Kenya.

Implementation of a Smartphone-Based Platform for Operative Feedback at Tenwek Hospital in Kenya: A Mixed Methods Study.

BACKGROUND: The SIMPL operative feedback tool is used in many U.S. surgical residency programs. However, the challenges of implementation and benefits of the web-based platform in low- and middle-income countries are unknown. The aim of this study was to evaluate implementation of SIMPL in a general surgery residency training program in Kenya. METHODS: SIMPL was pilot tested at Tenwek Hospital from January through December 2021. Participant perspectives of SIMPL were elicited through a survey and semi-structured interviews. Descriptive statistics were used to analyze survey data. Inductive qualitative content analysis of interview responses was performed by two independent researchers. RESULTS: Fourteen residents and six faculty (100% response rate) were included in the study and completed over 600 operative assessments. All respondents reported numerical evaluations and dictated feedback were useful. Respondents felt that SIMPL was easy to use, improved quality and frequency of feedback, helped refine surgical skills, and increased resident autonomy. Barriers to use included participants forgetting to complete evaluations, junior residents not submitting evaluations when minimally involved in cases, and technological challenges. Suggestions for improvement included expansion of SIMPL to surgical subspecialties and allowing senior residents to provide feedback to juniors. All respondents wanted to continue using SIMPL, and 90% recommended use at other programs. CONCLUSION: Residents and faculty at Tenwek Hospital believed SIMPL were a positive addition to their training program. There were a few barriers to use and suggestions for improvement specific to the training environment in Kenya, but this study demonstrates it is feasible to use SIMPL in settings outside the U.S. with the appropriate resources.

Operative Case Volumes and Variation for General Surgery Training in East, Central, and Southern Africa.

BACKGROUND: Operative experience is a necessary part of surgical training. The College of Surgeons of East, Central, and Southern Africa (COSECSA), which oversees general surgery training programs in the region, has implemented guidelines for the minimum necessary case volumes upon completion of two (Membership) and five (Fellowship) years of surgical training. We aimed to review trainee experience to determine whether guidelines are being met and examine the variation of cases between countries. METHODS: Operative procedures were categorized from a cohort of COSECSA general surgery trainees and compared to the guideline minimum case volumes for Membership and Fellowship levels. The primary and secondary outcomes were total observed case volumes and cases within defined categories. Variations by country and development indices were explored. RESULTS: One hundred ninety-four trainees performed 69,283 unique procedures related to general surgery training. The review included 70 accredited hospitals and sixteen countries within Africa. Eighty percent of MCS trainees met the guideline minimum of 200 overall cases; however, numerous trainees did not meet the guideline minimum for each procedure. All FCS trainees met the volume target for total cases and orthopedics; however, many did not meet the guideline minimums for other categories, especially breast, head and neck, urology, and vascular surgery. The operative experience of trainees varied significantly by location and national income level. CONCLUSIONS: Surgical trainees in East, Central, and Southern Africa have diverse operative training experience. Most trainees fulfill the overall case volume requirements; however, further exploration of how to meet the demands of specific categories and procedures is necessary.

Trainee autonomy and surgical outcomes after emergency gastrointestinal surgery.

BACKGROUND: Operative meaningful trainee autonomy is an essential component of surgical training. Reduced trainee autonomy is frequently attributed to patient safety concerns, but this has not been examined within Kenya. We aimed to assess whether meaningful trainee autonomy was associated with a change in patient outcomes. METHODS: We investigated whether meaningful trainee autonomy was associated with a change in severe postoperative complications and all-cause in-hospital mortality in a previously described cohort undergoing emergency gastrointestinal operations. Each operation was reviewed to determine the presence of meaningful autonomy, defined as "supervision only" from faculty. Comparisons were made between faculty-led cases and cases with meaningful trainee autonomy. Multilevel logistic regression models were created for the outcomes of mortality and complications with the exposure of meaningful trainee autonomy, accounting for fixed effects of the Africa Surgical Outcomes Study Risk Score and random effects of discharge diagnoses. RESULTS: After excluding laparoscopy (N = 28) and missing data (N = 3), 451 operations were studied, and 343 (76.1%) had meaningful trainee autonomy. Faculty were more involved in operations with older age, cancer, prior complications, and higher risk scores. On unadjusted analysis, meaningful trainee autonomy was associated with mortality odds of 0.32 (95% confidence interval: 0.17-0.58) compared with faculty-led operations. Similarly, the odds of developing complications were 0.52 (95% confidence interval: 0.32-0.84) with meaningful trainee autonomy compared with faculty-led operations. When adjusting for Africa Surgical Outcomes Study Score and clustering discharge diagnoses, the odds of mortality (odds ratio 0.58; 95% confidence interval: 0.27-1.2) and complication (odds ratio 0.83; 95% confidence interval: 0.47-1.5) were not significant. CONCLUSION: Our findings support that increasing trainee autonomy does not change patient outcomes in selected emergency gastrointestinal operations. Further, trainees and faculty appropriately discern patients at higher risk of complications and mortality, and the selective granting of trainee autonomy does not affect patient safety.

Stability of Prognostic Estimation Using the CAPRA Score Incorporating Imaging-based vs Physical Exam-based Staging.

PURPOSE: Although official T-staging criteria for prostate cancer are based on digital rectal examination findings, providers increasingly rely on transrectal US and MRI to define pragmatic clinical stage to guide management. We assessed the impact of incorporating imaging findings into T-staging on performance of a well-validated prognostic instrument. MATERIALS AND METHODS: Patients who underwent radical prostatectomy for prostate cancer diagnosed between 2000 and 2019 with stage ≤cT3a on both digital rectal examination and imaging (transrectal US/MRI) were included. The University of California, San Francisco CAPRA (Cancer of the Prostate Risk Assessment) score was computed 2 ways: (1) incorporating digital rectal examination-based T stage and (2) incorporating imaging-based T stage. We assessed for risk changes across the 2 methods and associations of CAPRA (by both methods) with biochemical recurrence, using unadjusted and adjusted Cox proportional hazards models. Model discrimination and net benefit were assessed with time-dependent area under the curve and decision curve analysis, respectively. RESULTS: Of 2,222 men included, 377 (17%) increased in CAPRA score with imaging-based staging (P < .01). Digital rectal examination-based (HR 1.54; 95% CI 1.48-1.61) and imaging-based (HR 1.52; 95% CI 1.46-1.58) CAPRA scores were comparably accurate for predicting recurrence with similar discrimination and decision curve analyses. On multivariable Cox regression, positive digital rectal examination at diagnosis (HR 1.29; 95% CI 1.09-1.53) and imaging-based clinical T3/4 disease (HR 1.72; 95% CI 1.43-2.07) were independently associated with biochemical recurrence. CONCLUSIONS: The CAPRA score remains accurate whether determined using imaging-based staging or digital rectal examination-based staging, with relatively minor discrepancies and similar associations with biochemical recurrence. Staging information from either modality can be used in the CAPRA score calculation and still reliably predict risk of biochemical recurrence.

Observation-derived 2010-2019 trends in methane emissions and intensities from US oil and gas fields tied to activity metrics.

The United States is the world's largest oil/gas methane emitter according to current national reports. Reducing these emissions is a top priority in the US government's climate action plan. Here, we use a 2010 to 2019 high-resolution inversion of surface and satellite observations of atmospheric methane to quantify emission trends for individual oil/gas production regions in North America and relate them to production and infrastructure. We estimate a mean US oil/gas methane emission of 14.8 (12.4 to 16.5) Tg a-1 for 2010 to 2019, 70% higher than reported by the US Environmental Protection Agency. While emissions in Canada and Mexico decreased over the period, US emissions increased from 2010 to 2014, decreased until 2017, and rose again afterward. Increases were driven by the largest production regions (Permian, Anadarko, Marcellus), while emissions in the smaller production regions generally decreased. Much of the year-to-year emission variability can be explained by oil/gas production rates, active well counts, and new wells drilled, with the 2014 to 2017 decrease driven by reduction in new wells and the 2017 to 2019 surge driven by upswing of production. We find a steady decrease in the oil/gas methane intensity (emission per unit methane gas production) for almost all major US production regions. The mean US methane intensity decreased from 3.7% in 2010 to 2.5% in 2019. If the methane intensity for the oil/gas supply chain continues to decrease at this pace, we may expect a 32% decrease in US oil/gas emissions by 2030 despite projected increases in production.

An anesthesia-centered bundle to reduce postoperative pulmonary complications: The PRIME-AIR study protocol.

BACKGROUND: Postoperative pulmonary complications (PPCs) are a major cause of morbidity and mortality after open abdominal surgery. Optimized perioperative lung expansion may minimize the synergistic factors responsible for the multiple-hit perioperative pulmonary dysfunction. This ongoing study will assess whether an anesthesia-centered bundle focused on perioperative lung expansion results in decreased incidence and severity of PPCs after open abdominal surgery. METHODS: Prospective multicenter randomized controlled pragmatic trial in 750 adult patients with at least moderate risk for PPCs undergoing prolonged (≥2 hour) open abdominal surgery. Participants are randomized to receive either a bundle intervention focused on perioperative lung expansion or usual care. The bundle intervention includes preoperative patient education, intraoperative protective ventilation with individualized positive end-expiratory pressure to maximize respiratory system compliance, optimized neuromuscular blockade and reversal management, and postoperative incentive spirometry and early mobilization. Primary outcome is the distribution of the highest PPC severity by postoperative day 7. Secondary outcomes include the proportion of participants with: PPC grades 1-2 through POD 7; PPC grades 3-4 through POD 7, 30 and 90; intraoperative hypoxemia, rescue recruitment maneuvers, or cardiovascular events; and any major extrapulmonary postoperative complications. Additional secondary and exploratory outcomes include individual PPCs by POD 7, length of postoperative oxygen therapy or other respiratory support, hospital resource use parameters, Patient-Reported Outcomes Measurements (PROMIS®) questionnaires for dyspnea and fatigue collected before and at days 7, 30 and 90 after surgery, and plasma concentrations of lung injury biomarkers (IL6, IL-8, RAGE, CC16, Ang-2) analyzed from samples obtained before, end of, and 24 hours after surgery. DISCUSSION: Participant recruitment for this study started January 2020; results are expected in 2024. At the conclusion of this trial, we will determine if this anesthesia-centered strategy focused on perioperative lung expansion reduces lung morbidity and healthcare utilization after open abdominal surgery. TRIAL REGISTRATION: ClinicalTrial.gov NCT04108130.

PSA density does not improve predictive accuracy of the UCSF-CAPRA score.

INTRODUCTION: The University of California, San Francisco Cancer of the Prostate Risk Assessment (CAPRA) score is a validated tool using factors at diagnosis to predict prostate cancer outcomes after radical prostatectomy (RP). This study evaluates whether substitution of prostate-specific antigen (PSA) density for serum PSA improves predictive performance of the clinical CAPRA model. METHODS: Participants were diagnosed in 2000-2019 with stage T1/T2 cancer, underwent RP, with at least a 6-month follow-up. We computed standard CAPRA score using diagnostic age, Gleason grade, percent positive cores, clinical T stage, and serum PSA, and an alternate score using similar variables but substituting PSA density for PSA. We reported CAPRA categories as low (0-2), intermediate (3-5), and high (6-10) risk. Recurrence was defined as two consecutive PSA ≥ 0.2 ng/mL or receipt of salvage treatment. Life table and Kaplan-Meier analysis evaluated recurrence-free survival after prostatectomy. Cox proportional hazards regression models tested associations of standard or alternate CAPRA variables with recurrence risk. Additional models tested associations between standard or alternate CAPRA score with recurrence risk. Cox log-likelihood ratio test (-2 LOG L) assessed model accuracy. RESULTS: A total of 2880 patients had median age 62 years, GG1 30% and GG2 31%, median PSA 6.5, and median PSA density 0.19. Median postoperative follow-up was 45 months. Alternate CAPRA model was associated with shifts in risk scores, with 16% of patients increasing and 7% decreasing (p < 0.01). Recurrence-free survival after RP was 75% at 5 years and 62% at 10 years. Both CAPRA component models were associated with recurrence risk after RP on Cox regression. Covariate fit statistics showed better fit for standard CAPRA model versus alternate (p < 0.01). Standard (hazard ratio [HR]: 1.55; 95% confidence interval [CI]: 1.50-1.61) and alternate (HR: 1.50; 95% CI: 1.44-1.55) CAPRA scores were associated with recurrence risk, with better fit for standard model (p < 0.01). CONCLUSIONS: In a 2880 patient cohort followed for median 45 months after RP, alternate CAPRA model using PSA density was associated with higher biochemical recurrence (BCR) risk, but performed inferior to standard CAPRA at predicting BCR. While PSA density is an established prognostic variable in prediagnostic settings and sub-stratifying low-risk disease, it does not improve BCR model predictive accuracy when applied across a range of cancer risk.

Novel canonical and non-canonical viral antigens extend current targets for immunotherapy of HPV-driven cervical cancer.

Current immunotherapeutic approaches for human papillomavirus (HPV)-driven cervical cancer target the viral oncogenes E6 and E7. We report viral canonical and alternative reading frame (ARF)-derived sequences presented on cervical tumor cells, including antigens encoded by the conserved viral gene E1. We confirm immunogenicity of the identified viral peptides in HPV-positive women, and women with cervical intraepithelial neoplasia. We observe consistent transcription of the E1, E6, and E7 genes in 10 primary cervical tumor resections from the four most common high-risk HPV subtypes (HPV16, 18, 31, and 45), suggesting the suitability of E1 as therapeutic target. We finally confirm HLA presentation of canonical peptides derived from E6 and E7, and ARF-derived viral peptides from a reverse-strand transcript spanning the HPV E1 and E2 genes in primary human cervical tumor tissue. Our results extend currently known viral immunotherapeutic targets in cervical cancer and highlight E1 as an important cervical cancer antigen.

CT without borders: Comparison of diagnoses for abdominal pain from a teaching hospital in rural Kenya and a US academic medical center.

PURPOSE: Radiology global health opportunities are expanding as more hospitals in low- and middle-income countries utilize CT. This creates opportunities for global health program building, education, service, and research. This study determines the diagnostic yield and variety of abdominopelvic CT diagnoses for abdominal pain in a US academic medical center (UW) compared to a rural Kenyan teaching hospital (Tenwek). METHODS: A retrospective, cross-sectional sequential sample of 750 adults from both hospitals who underwent abdominopelvic CT for abdominal pain from February 2019 through July 2020 was obtained. Exclusion criteria were trauma, cancer staging, and recent hospitalization or surgery. Patient age, sex, comparison studies, use of contrast, known cancer diagnosis, and CT diagnoses were compared. Negative exam rate, acute abdomen diagnosis, and new cancer diagnosis were recorded. Statistical analysis was performed using R. RESULTS: 750 UW patients met inclusion criteria (mean age 53.3 ± 20 years; 442 women) and 750 Tenwek patients met inclusion criteria (mean age 52.5 ± 18 years; 394 women). 72% of UW patients had comparison imaging compared to 6% of Tenwek patients. 11% (83/750) of UW patients had a known cancer diagnosis compared to 1% (10/750) of Tenwek patients. 39% of UW patients had a negative exam compared to 23% of Tenwek patients (p < 0.001). 58% of UW patients had an acute abdomen diagnosis compared to 38% of Tenwek patients (p < 0.001). 10 of the 15 top acute abdomen diagnoses were shared, but in different order of frequency. Diagnoses unique to UW were diverticulitis, constipation, stercoral colitis, and epiploic appendagitis. Diagnoses unique to Tenwek were tuberculosis and hydatidosis. 3% of UW patients received a new cancer diagnosis (7/19 metastatic), compared to 40% of Tenwek patients (153/303 metastatic) (p < 0.001). CONCLUSION: For adults undergoing CT for abdominal pain, there are differences in the prevalence of abdominal pain diagnoses, new cancer diagnosis, and negative exam rate between the rural Kenyan teaching hospital and the US academic medical center.

Diet, physical activity, and obesity among ART-experienced people with HIV in South Africa.

The prevalence of non-communicable diseases (NCDs) is increasing in South Africa, in part due to poor nutrition, physical inactivity, and obesity. We characterized the habits and understanding of diet, exercise, and obesity among people with HIV (PWH) taking antiretroviral therapy (ART). We conducted a cross-sectional study of ART-experienced PWH attending an HIV community health center near Cape Town, South Africa. We included PWH currently prescribed ART, older than 21y, and not pregnant. We collected demographic and clinical information and interviewed participants regarding their behaviors and knowledge related to diet, physical activity, and obesity. From March 2015 - February 2016, we enrolled 458 participants. Self-reported diets were low in nutritional diversity: 202 reported eating only starch and protein without vegetable/fruit in the prior 24 h. Although most participants (96%) acknowledged that exercise had health benefits, only 215 participants engaged in daily 30-minute walking or exercise. One quarter of participants recognized nocontributors to obesity, and almost 20% identified no health problems associated with obesity. Participants had diets low in nutritional diversity, modest exercise habits, and limited understanding of the impact of obesity on health. Further understanding of barriers to improving diet and exercise and reducing obesity are essential, especially as PWH age.

Measurement of Medial Tibial Eminence Dimensions for the Clinical Evaluation of ACL-Injured Knees: A Comparison between CT and MRI.

Anterior cruciate ligament (ACL) injuries commonly lead to translational and rotational tibiofemoral instability. The morphology of the medial tibial eminence (MTE) has received increased attention regarding its role in tibiofemoral stability in ACL-injured knees. Therefore, quantification of MTE dimensions on clinical imaging may help clinicians predict knee stability after ACL injury. Although magnetic resonance imaging (MRI) is routinely obtained in patients with ACL injuries, whether the dimensions of the MTE can be accurate quantified on MRI is unknown. The purpose of this study was to assess the degree of correlation between measurements of MTE height and width on computed tomography (CT) versus MRI. An institutional picture archiving and communication system imaging database was used to identify patients aged between 15 and 60 years who received concurrent MRI and CT of the same knee within a 1-year interval. Knees with significant arthrosis, deformity, intraarticular fracture, or hardware-related artifact that obscured visualization of the MTE were excluded. Mean differences and interstudy agreement between CT and MRI MTE measurements were compared using concordance correlation coefficient (r c) and Bland-Altman analysis. A total of 41 knees in 38 patients (mean age, 37 years; 82% male) were analyzed. Interrater reliability for CT and MRI measurements was high (intraclass correlation coefficient = 0.740-0.954). On coronal CT and MRI, mean MTE height measurements were 10.4 ± 1.9 and 10.4 ± 1.8 mm, respectively; mean MTE width measurements were 14.6 ± 3.6 and 14.2 ± 3.0 mm, respectively. On sagittal CT and MRI, mean MTE height measurements were 11.6 ± 1.7 and 11.7 ± 1.7 mm, respectively; mean MTE width measurements were 36.5 ± 4.8 and 36.2 ± 5.0 mm, respectively. Good agreement was observed between CT and MRI measurements of MTE height and width on coronal and sagittal planes (r c = 0.947-0.969). Measurements of MTE height and width were similar on MRI relative to CT on both coronal and sagittal planes. MRI may be suitable for characterizing the dimensions of the MTE when clinically evaluating patients with ACL injuries, potentially allowing for individualized patient care.

Identification of neoantigens in oesophageal adenocarcinoma.

Oesophageal adenocarcinoma (OAC) has a relatively poor long-term survival and limited treatment options. Promising targets for immunotherapy are short peptide neoantigens containing tumour mutations, presented to cytotoxic T-cells by human leucocyte antigen (HLA) molecules. Despite an association between putative neoantigen abundance and therapeutic response across cancers, immunogenic neoantigens are challenging to identify. Here we characterized the mutational and immunopeptidomic landscapes of tumours from a cohort of seven patients with OAC. We directly identified one HLA-I presented neoantigen from one patient, and report functional T-cell responses from a predicted HLA-II neoantigen in a second patient. The predicted class II neoantigen contains both HLA I and II binding motifs. Our exploratory observations are consistent with previous neoantigen studies in finding that neoantigens are rarely directly observed, and an identification success rate following prediction in the order of 10%. However, our identified putative neoantigen is capable of eliciting strong T-cell responses, emphasizing the need for improved strategies for neoantigen identification.

Implementation of a Surgical Critical Care Service Reduces Failure to Rescue in Emergency Gastrointestinal Surgery in Rural Kenya.

OBJECTIVE: We aimed to evaluate the implementation of a dedicated Surgical critical care service (SCCS) on failure to rescue (FTR) rates in rural Kenya. SUMMARY BACKGROUND DATA: FTR adversely impacts perioperative outcomes. In the resource-limited contexts of low- and middle-income countries, emergency gastrointestinal surgery carries high morbidity and mortality rates. Quality improvement initiatives that decrease FTR rates are essential for improving perioperative care. METHODS: All patients who underwent emergency gastrointestinal surgery between January 2016 and June 2019 at Tenwek Hospital in rural Kenya were reviewed. Critical care capabilities were constant throughout the study period. A supervised surgical resident was dedicated to the daily care of critically ill surgical patients beginning in January 2018. The impact of the SCCS initiation on the outcome of FTR was evaluated, controlling for patient complexity via the African Surgical Outcomes Study Surgical Risk Score. RESULTS: A total of 484 patients were identified, consisting of 278 without and 206 with an active SCCS. A total of 165 (34.1%) patients experienced postoperative complications, including 49 mortalities (10.1%) yielding an FTR rate of 29.7%. The FTR rate decreased after SCCS implementation from 36.8% (95% CI: 26.7%-47.8%) to 21.8% (95% CI: 13.2%-32.6%) ( P = 0.035) despite an increase in the average patient African Surgical Outcomes Study score from 14.5 (95% CI, 14.1-14.9) to 15.2 (95% CI, 14.7-15.7) ( P =0.03). CONCLUSIONS: The implementation of an SCCS in rural Kenya resulted in decreased rates of FTR despite an increase in patient complexity and severity of critical illness.

Shieldin and CST co-orchestrate DNA polymerase-dependent tailed-end joining reactions independently of 53BP1-governed repair pathway choice.

53BP1 regulates DNA end-joining in lymphocytes, diversifying immune antigen receptors. This involves nucleosome-bound 53BP1 at DNA double-stranded breaks (DSBs) recruiting RIF1 and shieldin, a poorly understood DNA-binding complex. The 53BP1-RIF1-shieldin axis is pathological in BRCA1-mutated cancers, blocking homologous recombination (HR) and driving illegitimate non-homologous end-joining (NHEJ). However, how this axis regulates DNA end-joining and HR suppression remains unresolved. We investigated shieldin and its interplay with CST, a complex recently implicated in 53BP1-dependent activities. Immunophenotypically, mice lacking shieldin or CST are equivalent, with class-switch recombination co-reliant on both complexes. ATM-dependent DNA damage signalling underpins this cooperation, inducing physical interactions between these complexes that reveal shieldin as a DSB-responsive CST adaptor. Furthermore, DNA polymerase ζ functions downstream of shieldin, establishing DNA fill-in synthesis as the physiological function of shieldin-CST. Lastly, 53BP1 suppresses HR and promotes NHEJ in BRCA1-deficient mice and cells independently of shieldin. These findings showcase the resilience of the 53BP1 pathway, achieved through the collaboration of chromatin-bound 53BP1 complexes and DNA end-processing effector proteins.

The Recovering Together study protocol: A single-blind RCT to prevent chronic emotional distress in patient-cargiver dyads in the Neuro-ICU.

INTRODUCTION: Patients admitted to the Neuroscience Intensive Care Unit (Neuro-ICU) with acute neurological illnesses (ANI; e.g., stroke, tumor, TBI) and their informal caregivers experience high rates of anxiety, depression, and posttraumatic stress. To address this need, we previously developed the Recovering Together (RT) dyadic intervention to help prevent chronic emotional distress in both patients and caregivers. Currently, we are conducting a fully-powered, single-blind randomized clinical trial (RCT) to evaluate the efficacy of RT versus an attention matched health education control. Here, we describe the protocol and current status of this RCT. METHODS: We aim to recruit 194 at risk patient-caregiver dyads from the Neuro-ICU at MGH. Eligible dyads include patients diagnosed with ANI, cognitively intact, at least one partner endorses emotional distress (on Hospital Anxiety and Depression Scale), English speaking, age 18 or older. Dyads are randomized to the intervention (RT-1) or control condition (RT-2) (both six sessions). RT-1 teaches resiliency (e.g., coping, mindfulness) and interpersonal skills. RT-2 provides education on health-related topics (e.g., stress, self-care, adhering to medical recommendations). Blinded research assistants collect measures at baseline, post-intervention, and three months follow-up. We will conduct mixed linear, mediation, and actor-partner interdependence models to examine changes in dyads' outcomes across time. RESULTS: We have recruited 41 dyads and aim to recruit 194 total. DISCUSSION: If successful, we plan to test RT in a large-scale, multisite hybrid effectiveness-implementation study in Neuro-ICUs across the country. Enhancing psychosocial supports for patients and families could improve health outcomes, healthcare efficiency, and the culture of these units.

Ionizing Radiation Drives Key Regulators of Antigen Presentation and a Global Expansion of the Immunopeptidome.

Little is known about the pathways regulating MHC antigen presentation and the identity of treatment-specific T cell antigens induced by ionizing radiation. For this reason, we investigated the radiation-specific changes in the colorectal tumor cell proteome. We found an increase in DDX58 and ZBP1 protein expression, two nucleic acid sensing molecules likely involved in induction of the dominant interferon response signature observed after genotoxic insult. We further observed treatment-induced changes in key regulators and effector proteins of the antigen processing and presentation machinery. Differential regulation of MHC allele expression was further driving the presentation of a significantly broader MHC-associated peptidome postirradiation, defining a radiation-specific peptide repertoire. Interestingly, treatment-induced peptides originated predominantly from proteins involved in catecholamine synthesis and metabolic pathways. A nuanced relationship between protein expression and antigen presentation was observed where radiation-induced changes in proteins do not correlate with increased presentation of associated peptides. Finally, we detected an increase in the presentation of a tumor-specific neoantigen derived from Mtch1. This study provides new insights into how radiation enhances antigen processing and presentation that could be suitable for the development of combinatorial therapies. Data are available via ProteomeXchange with identifier PXD032003.