Biochemical and functional characterization of the p.A165T missense variant of mitochondrial amidoxime-reducing component 1.

Recent genome-wide association studies have identified a missense variant p.A165T in mitochondrial amidoxime-reducing component 1 (mARC1) that is strongly associated with protection from all-cause cirrhosis and improved prognosis in nonalcoholic steatohepatitis. The precise mechanism of this protective effect is unknown. Substitution of alanine 165 with threonine is predicted to affect mARC1 protein stability and to have deleterious effects on its function. To investigate the mechanism, we have generated a knock-in mutant mARC1 A165T and a catalytically dead mutant C273A (as a control) in human hepatoma HepG2 cells, enabling characterization of protein subcellular distribution, stability, and biochemical functions of the mARC1 mutant protein expressed from its endogenous locus. Compared to WT mARC1, we found that the A165T mutant exhibits significant mislocalization outside of its traditional location anchored in the mitochondrial outer membrane and reduces protein stability, resulting in lower basal levels. We evaluated the involvement of the ubiquitin proteasome system in mARC1 A165T degradation and observed increased ubiquitination and faster degradation of the A165T variant. In addition, we have shown that HepG2 cells carrying the MTARC1 p.A165T variant exhibit lower N-reductive activity on exogenously added amidoxime substrates in vitro. The data from these biochemical and functional assays suggest a mechanism by which the MTARC1 p.A165T variant abrogates enzyme function which may contribute to its protective effect in liver disease.

Design and Implementation of a Didactic Curriculum in a Large Neonatal-Perinatal Medicine Fellowship Program: A Single-center Experience.

OBJECTIVE: Although the Accreditation Council for Graduate Medical Education and American Board of Pediatrics (ABP) provide regulations and guidance on fellowship didactic education, each program establishes their own didactic schedules to address these learning needs. Wide variation exists in content, educators, amount of protected educational time, and the format for didactic lectures. This inconsistency can contribute to fellow dissatisfaction, a perceived poor learning experience, and poor attendance. Our objective was to create a Neonatal-Perinatal Medicine (NPM) fellow curriculum based on adult learning theory utilizing fellow input to improve the perceived fellow experience. STUDY DESIGN: A needs assessment of current NPM fellows at Cincinnati Children's Hospital was conducted to guide the development of a new curriculum. Fellow perception of educational experience and board preparedness before and after introduction of the new curriculum was collected. Study period was from October 2018 to July 2021. RESULTS: One hundred percent of the fellows responded to the needs assessment survey. A response rate of 100 and 87.5% were noted on mid-curriculum survey and postcurriculum survey, respectively. Key themes identified and incorporated into the curriculum included schedule structure, content, and delivery mode. A new didactic curriculum implementing a consistent schedule of shorter lectures grouped by organ system targeting ABP core content was created. After curriculum implementation, fellows had higher self-perception of board preparedness, and overall improved satisfaction. CONCLUSION: Our positive experience in implementing this curriculum provides a framework for individual programs to implement similar curricula, and could be utilized to aid in development of national NPM curricula. KEY POINTS: · Fellowship didactic education varies significantly resulting in learner dissatisfaction and poor attendance.. · Widespread need to restructure didactic curricula exists.. · Our study provides a framework for future curricula..

Reference intervals for high sensitivity cardiac troponin I and N-terminal pro-B-type natriuretic peptide in children and adolescents on the Siemens Atellica.

OBJECTIVES: The cardiac biomarkers high sensitivity cardiac troponin I (hs-cTnI) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are utilised in paediatric healthcare for the diagnosis and prognostic assessment of many conditions including myocarditis, congenital heart disease, multisystem inflammatory syndrome in children (MIS-C) and heart failure. However, the standardised age-related reference intervals, 99th percentile cut-offs and clinical guidelines are not available, making the interpretation of these biomarkers challenging. This study aimed to generate normative data in a paediatric cohort for the Siemens Atellica® IM 1300 analyser. METHODS: Residual plasma samples were collected from children aged up to 17 years attending primary care and out-patient settings and with no apparent evidence of cardiac dysfunction, renal dysfunction or other confounders. Reference intervals were generated using the 2.5th-97.5th percentiles, and 99th percentile cut-offs determined according to CLSI EP28-A3c. RESULTS: Statistical analysis revealed that partitioning was not required for gender for either biomarker. The reference interval for hs-cTnI for children aged one month to 16 years (n=292, 146 females and 146 males) was <14 ng/L with a 99th percentile cut-off of 19 ng/L. The reference interval for NT-proBNP for children aged one month up to one year was <714 ng/L (n=14) and for children aged 1-16 years (n=339) was <295 ng/L. CONCLUSIONS: This is the first paediatric reference interval data generated on the Siemens Atellica® solution. These reference intervals and 99th percentiles will inform clinical decisions in the paediatric cardiology setting.

The implementation of non-weight focused approaches in clinical practice: A Canadian cross-sectional study among registered dietitians.

BACKGROUND: An increasing number of dietitians use non-diet approaches, referred to as non-weight focused practice approaches (NWFAs), in clinical practice when working with higher weight adult clients. However, the factors that impact dietitians' ability to successfully implement these approaches in practice are unknown. METHODS: Aiming to examine how implementing NWFAs in clinical practice differs based on the extent to which a dietitian uses NWFAs with their clients, we conducted a cross-sectional online survey among Canadian registered dietitians who work with higher weight adults (May to July 2021), developed and validated following the Consolidated Framework for Implementation Research. Descriptive statistics were conducted to identify barriers and facilitators with respect to implementing NWFAs. The Kruskal-Wallis was used to test for differences in barriers and facilitators with respect to implementing NWFAs among five different practice approaches. The results showed that, among participants (n = 383; 82% white; 95% women) the most important barriers for implementation of NWFAs were clients' focus on weight as an outcome, when losing weight is a condition to access enhanced services, requiring changes to their practice philosophy, difficulty funding professional development and not having sufficient skills or knowledge to implement NWFAs in practice. Top-rated facilitators included the use of clinical guidelines, scientific publications and educational materials, which were rated with higher agreement across all implementation stages (p < 0.001). CONCLUSIONS: The present study highlights important factors that may impact the effective implementation of NWFAs in dietetic practice for higher weight adult clients, which is essential to minimise barriers in practice.

Discovery and SAR Study of Boronic Acid-Based Selective PDE3B Inhibitors from a Novel DNA-Encoded Library.

Human genetic evidence shows that PDE3B is associated with metabolic and dyslipidemia phenotypes. A number of PDE3 family selective inhibitors have been approved by the FDA for various indications; however, given the undesirable proarrhythmic effects in the heart, selectivity for PDE3B inhibition over closely related family members (such as PDE3A; 48% identity) is a critical consideration for development of PDE3B therapeutics. Selectivity for PDE3B over PDE3A may be achieved in a variety of ways, including properties intrinsic to the compound or tissue-selective targeting. The high (>95%) active site homology between PDE3A and B represents a massive obstacle for obtaining selectivity at the active site; however, utilization of libraries with high molecular diversity in high throughput screens may uncover selective chemical matter. Herein, we employed a DNA-encoded library screen to identify PDE3B-selective inhibitors and identified potent and selective boronic acid compounds bound at the active site.

International Newborn Screening Practices for the Early Detection of Congenital Adrenal Hyperplasia.

INTRODUCTION: Newborn screening (NBS) programmes vary internationally in their approach to screening. Guidelines for congenital adrenal hyperplasia (CAH) screening recommend the use of two-tier testing and gestational age cutoffs to minimise false-positive results. The aims of this study were to describe (1) the approaches; (2) protocols used; and (3) available outcomes for CAH screening internationally. METHODS: All members of the International Society for Neonatal Screening were asked to describe their CAH NBS protocols, with an emphasis on the use of second-tier testing, 17-hydroxyprogesterone (17OHP) cutoffs, and gestational age and birth weight adjustments. If available, screening outcomes were requested. RESULTS: Representatives from 23 screening programmes provided data. Most (n = 14; 61%) recommend sampling at 48-72 h of life. Fourteen (61%) use single-tier testing and 9 have a two-tier testing protocol. Gestational age cutoffs are used in 10 programmes, birth weight cutoffs in 3, and a combination of both in 9. One programme does not use either method of adjusting 17OHP cutoffs. Case definition of a positive test and the response to a positive test differed between programmes. CONCLUSIONS: We have demonstrated significant variation across all aspects of NBS for CAH, including timing, the use of single versus two-tier testing and cutoff interpretation. Collaboration between international screening programmes and implementation of new techniques to improve screen efficacy will facilitate ongoing expansion and quality improvement in CAH NBS.

Dual modality feeders: a group of human milk feeders with unique practices and needs.

OBJECTIVE: Dual modality feeding (DMF) - feeding human milk interchangeably from the breast and from a bottle - comes with unique practical, emotional and relational challenges, as well as support needs. Yet, there is little research that explores the experiences of individuals who use DMF in the Canadian context. The aim of this study is to explore the practices, challenges, reasons and enablers of DMF. DESIGN: Repeat, semi-structured one-on-one interviews were conducted at 8 weeks and 22 weeks postpartum. Interview transcripts were thematically analysed using a critical feminist lens. SETTING: Nova Scotia, Canada. PARTICIPANTS: Ten DMF mothers. RESULTS: DMF practices were influenced by a mix of social and material circumstances, including breast-feeding challenges, the involvement of support persons, finances and access to lactation support. Individuals who predominantly fed at the breast expressed milk strategically to mitigate transitory breast-feeding challenges, for convenience under specific circumstances, and to share feeding responsibilities with other caregivers for personal and practical reasons. Individuals who mainly bottle-fed did so due to long-term breast-feeding challenges or a need to return to employment. Enablers of successful DMF were consistent between the two groups and included practical, personal and relational aspects. CONCLUSIONS: DMF is a unique practice compared to feeding human milk solely from the breast or bottle. Despite the potential growing prevalence of DMF, it is currently understudied and inadequately addressed in existing support programmes in Nova Scotia. Tailored programming and public messaging are needed to support DMF families.

An Examination of the Practice Approaches of Canadian Dietitians Who Counsel Higher-Weight Adults Using a Novel Framework: Emerging Data on Non-Weight-Focused Approaches.

Non-weight-focused approaches (NWFAs) may be used by some clinicians when working with higher-weight clients. In contrast to weight-focused approaches (WFAs), NWFAs de-emphasize or negate weight loss and emphasize overall diet quality and physical activity. The extent to which WFAs, NWFAs, or a combination of both WFAs and NWFAs are used by dietitians is unknown in Canada and globally. This study surveyed Canadian Registered Dietitians (RDs) who counsel higher-weight clients to assess which practice approaches are most commonly used, how they view the importance of weight, and how they define "obesity" for the study population. Five practice approaches were initially defined and used to inform the survey: solely weight-focused; moderately weight-focused; those who fluctuate between weight-focused/weight-inclusive approaches (e.g., used both approaches); weight inclusive and; weight liberated. Participants (n = 383; 94.8% women; 82.2% white) were recruited using social media and professional listservs. Overall, 45.4% of participants used NWFAs, 40.5% fluctuated between weight-focused/moderately weight-focused, and 14.1% used weight-focused approaches (solely weight focused and moderately weight focused). Many participants (63%) agreed that weight loss was not important for higher-weight clients. However, 81% of participants received no formal preparation in NWFAs during their education or training. More research is needed to understand NWFAs and to inform dietetic education in support of efforts to eliminate weight stigma and provide inclusive access to care.

The European Register of Specialists in Clinical Chemistry and Laboratory Medicine: code of conduct, version 3 - 2023.

Whilst version 2 focussed on the professional conduct expected of a Specialist in Laboratory Medicine, version 3 builds on the responsibilities for ethical conduct from point of planning to point of care. Particular responsibilities that are outlined include: - The need for evidence when planning a new service, providing assurance that a new test does not do harm - Maintaining respect for patient confidentiality, their religious/ethnic beliefs, the need for informed consent to test, agreement on retrospective use of samples as part of governance envelopes in the pre-analytical phase - Ensuring respect for patient autonomy in the response to untoward results generated in the analytical phase - Supporting the safety of patients in the post-analytical phase through knowledge-based interpretation and presentation of results - The duty of candour to disclose and respond to error across the total testing process - Leading initiatives to harmonise and standardise pre-analytical, analytical and post-analytical phases to ensure more consistent clinical decision making with utilisation of demand management to ensure more equitable access to scarce resources - Working with emerging healthcare providers beyond the laboratory to ensure consistent application of high standards of clinical care In identifying opportunities for wider contributions to resolving ethical challenges across healthcare the need is also highlighted for more external quality assurance schemes and ethics-based quality indicators that span the total testing process.

Severe, Nondelirium Agitation as an Underreported Characteristic of Precipitated Fentanyl Withdrawal: A Case Report.

Opioid overdose deaths continue to rise in conjunction with a surge in fentanyl use. Treating withdrawal and initiating recovery may involve rapid initiations of medications for opioid use disorder, such as buprenorphine, but there is a high risk of precipitated withdrawal. We report a case of a 30-year-old man in police custody who experienced precipitated fentanyl withdrawal, and it was refractory to continued buprenorphine escalation. After buprenorphine, he exhibited a particularly dramatic, nondelirium agitation, which we suspect is a common yet underreported characteristic of precipitated withdrawal. Although there was initial concern for delirium secondary to benzodiazepine withdrawal, this was ruled out by mental status examination and verified later by the patient himself. Nondelirium agitation, clarified by mental status testing, ought to be further reported and characterized in future studies of precipitated withdrawal as clinicians and researchers tackle the new challenges of widespread fentanyl use in the United States.

The renal-bone axis in older people living with HIV on stable antiretroviral therapy: A sub-analysis of the GS-US-104-0423 study.

BACKGROUND: Data on low bone mineral density (BMD) in people living with HIV (PLWH) are mainly derived from younger adults; little is known about how antiretroviral therapy (ART) and alterations in the renal-bone axis relate to BMD in older PLWH. METHODS: Cross-sectional study of men > 50 years and post-menopausal women with HIV. Antiretroviral therapy exposure was stratified into four groups based on use of tenofovir disoproxil fumarate (TDF) and protease inhibitors (PI): non-TDF/non-PI, non-TDF/PI, TDF/non-PI, and TDF/PI. Bone mineral density was measured by dual X-ray absorptiometry (DXA). Bone turnover/regulatory markers and renal tubular function were analysed in stored plasma and urine samples. The association of ART exposure and bone/renal biomarkers on BMD was explored using logistic regression models. RESULTS: 247 individuals (median [IQR] age 57 [53, 65] years; 47% female; 13% of Black ethnicity; CD4 count 643 [473, 811] cells/mm3; and 98% with HIV RNA < 200 copies/mL) were included. Bone turnover and renal tubular function differed significantly by ART exposure. In analyses adjusted for demographic and traditional renal/bone risk factors, exposure to TDF and PI was associated with a fourfold greater risk of low BMD at the femoral neck and exposure to TDF and/or PI with a threefold greater risk of low BMD at the lumbar spine. The relationship between ART and low BMD was not altered by further adjustment for bone turnover or renal tubular function markers. CONCLUSIONS: The associations between low BMD and ART exposure (TDF vs. non-TDF and boosted vs. unboosted third agents) were minimally affected by adjustments for bone and kidney biomarkers.

Biochemical testing for inborn errors of metabolism: experience from a large tertiary neonatal centre.

Inborn errors of metabolism are an individually rare but collectively significant cause of mortality and morbidity in the neonatal period. They are identified by either newborn screening programmes or clinician-initiated targeted biochemical screening. This study examines the relative contribution of these two methods to the identification of inborn errors of metabolism and describes the incidence of these conditions in a large, tertiary, neonatal unit. We also examined which factors could impact the reliability of metabolic testing in this cohort. This is a retrospective, single-site study examining infants in whom a targeted metabolic investigation was performed from January 2018 to December 2020 inclusive. Data was also provided by the national newborn screening laboratory regarding newborn screening diagnoses. Two hundred and four newborns received a clinician-initiated metabolic screen during the time period examined with 5 newborns being diagnosed with an inborn error of metabolism (IEM) (2.4%). Of the 25,240 infants born in the hospital during the period examined, a further 11 newborns had an inborn error of metabolism diagnosed on newborn screening. This produced an incidence in our unit over the time described of 6.34 per 10,000 births. This number reflects a minimum estimate, given that the conditions diagnosed refer to early-onset disorders and distinctive categories of IEM only. Efficiency of the clinician-initiated metabolic screening process was also examined. The only statistically significant variable in requiring repeat metabolic screening was early day of life (z-score = - 2.58, p = 0.0098). A total of 28.4% was missing one of three key metabolic investigation parameters of blood glucose, ammonia or lactate concentration with ammonia the most common investigation missing. While hypoglycemia was the most common clinical rationale for a clinician-initiated metabolic test, it was a poor predictor of inborn error of metabolism with no newborns of 25 screened were diagnosed with a metabolic disorder. CONCLUSION: Clinician-targeted metabolic screening had a high diagnostic yield given the relatively low prevalence of inborn errors of metabolism in the general population. Thoughts should be given to the rationale behind each targeted metabolic test and what specific metabolic disease or category of inborn error of metabolism they are concerned along with commencing targeted testing. WHAT IS KNOWN: • Inborn errors of metabolism are a rare but potentially treatable cause of newborn mortality and morbidity. • A previous study conducted in a tertiary unit in an area with limited newborn screening demonstrated a diagnostic yield of 5.4%. WHAT IS NEW: • Clinician-initiated targeted metabolic screening has a good diagnostic performance even with a more expanded newborn screening programme. • Further optimisation could be achieved by examining the best timing and also the rationale of metabolic testing in the newborn period.

Frequent hypoxemia found in infants with bronchopulmonary dysplasia after weaning home oxygen.

OBJECTIVE: Parental reports and brief clinical examinations are the primary information used to assist clinicians in weaning home supplemental oxygen in infants with bronchopulmonary dysplasia (BPD). Recorded nocturnal oximetry provides an objective assessment of hypoxemia; however, it is unknown if it identifies clinically undetected hypoxemia in the home setting. Our objective was to determine if nocturnal oximetry can identify unreported hypoxemia in infants with BPD who appear ready to wean from supplemental oxygen. STUDY DESIGN: We conducted a retrospective chart review of infants born <32 weeks gestation with BPD who were discharged to home receiving supplemental oxygen and completed recorded nocturnal oximetry in room air during an 18-month period. Abnormal oximetry was defined as >5 min with SpO2 < 90% and/or an oxyhemoglobin desaturation index (ODI4) >5. Comparative analysis of patients with normal and abnormal overnight oximetry was performed using Fisher Exact and Wilcoxon signed-rank test. RESULTS: Thirty-five former premature infants completed nocturnal oximetry at 5.8 (3.4-8.3) months corrected age. Nocturnal oximetry was abnormal as defined in 67% of the cohort (n = 21). Five percent of patients were hypoxemic, 52% had frequent desaturation events, and 43% had both. No significant differences existed in neonatal characteristics between patients with normal and abnormal studies. CONCLUSIONS: Nocturnal oximetry was abnormal in the majority of infants with BPD who were otherwise clinically ready to wean from oxygen support, suggesting that recorded home oximetry could be a feasible and useful tool to evaluate for otherwise clinically unapparent nocturnal hypoxemia in patients with BPD.

LKB1 drives stasis and C/EBP-mediated reprogramming to an alveolar type II fate in lung cancer.

LKB1 is among the most frequently altered tumor suppressors in lung adenocarcinoma. Inactivation of Lkb1 accelerates the growth and progression of oncogenic KRAS-driven lung tumors in mouse models. However, the molecular mechanisms by which LKB1 constrains lung tumorigenesis and whether the cancer state that stems from Lkb1 deficiency can be reverted remains unknown. To identify the processes governed by LKB1 in vivo, we generated an allele which enables Lkb1 inactivation at tumor initiation and subsequent Lkb1 restoration in established tumors. Restoration of Lkb1 in oncogenic KRAS-driven lung tumors suppressed proliferation and led to tumor stasis. Lkb1 restoration activated targets of C/EBP transcription factors and drove neoplastic cells from a progenitor-like state to a less proliferative alveolar type II cell-like state. We show that C/EBP transcription factors govern a subset of genes that are induced by LKB1 and depend upon NKX2-1. We also demonstrate that a defining factor of the alveolar type II lineage, C/EBPα, constrains oncogenic KRAS-driven lung tumor growth in vivo. Thus, this key tumor suppressor regulates lineage-specific transcription factors, thereby constraining lung tumor development through enforced differentiation.

Tracheostomy prediction model in neonatal bronchopulmonary dysplasia via lung and airway MRI.

RATIONALE: Clinical management of neonatal bronchopulmonary dysplasia (BPD) is often imprecise and can vary widely between different institutions and providers, due to limited objective measurements of disease pathology severity. There is critical need to improve guidance on the application and timing of interventional treatments, such as tracheostomy. OBJECTIVES: To generate an imaging-based clinical tool for early identification of those patients with BPD who are likely to require later tracheostomy and long-term mechanical ventilation. METHODS: We conducted a prospective cohort study of n = 61 infants (55 BPD, 6 preterm non-BPD). Magnetic resonance imaging (MRI) scores of lung parenchymal disease were used to create a binomial logistic regression model for predicting tracheostomy requirement. This model was further investigated using clinical variables and MRI-quantified tracheomalacia (TM). MEASUREMENTS AND MAIN RESULTS: A model for predicting tracheostomy requirement was created using MRI parenchymal score. This model had 89% accuracy, 100% positive predictive value (PPV), and 85% negative predictive value (NPV), compared with 84%, 60%, and 83%, respectively, when using only relevant clinical variables. In a subset of patients with airway MRI (n = 36), a model including lung and TM measurements had 83% accuracy, 92% PPV, and 78% NPV. CONCLUSIONS: MRI-based measurements of parenchymal disease and TM can be used to predict need for tracheostomy in infants with BPD, more accurately than clinical factors alone. This prediction model has strong potential as a clinical tool for physicians and families for early determination of tracheostomy requirement.

The association of psychiatric and neurological comorbidities with outcomes in traumatic injury patients.

INTRODUCTION: Mental illness is a well-known risk factor for injury and injury recidivism. The impact of pre-existing psychiatric illness on trauma outcomes, however, has received less attention. Our study examines the relationship of pre-existing psychiatric illness on trauma outcomes including length of stay, cost, and mortality. METHODS: Patient data were obtained from the Healthcare Cost and Utilization Project's State Inpatient Database. All patients admitted for trauma in the Detroit metropolitan area from 1/1/2006 to 12/31/2014 were included. The relationship between individual psychiatric comorbidities (depression, psychosis, and other neurological disorders) and outcomes were evaluated with logistic regression (mortality) and generalized linear modeling (length of stay and cost). RESULTS: Over 260,000 records were reviewed. Approximately one-third (29.9%) of patients had one or more psychiatric diagnoses. Patients with depression had longer hospital stays (RR = 1.12, p < 0.001) and higher costs (RR = 1.07, p < 0.001), but also lower mortality (OR = 0.69, p < 0.001). Patients with psychosis had longer stays (RR = 1.18, p < 0.001), higher costs (RR = 1.02, p = 0.002), and lower mortality (OR = 0.61, p < 0.001). Patients with other neurological comorbidities had higher mortality (OR = 1.23, p < 0.001), longer stays (RR = 1.29, p < 0.001), and higher costs (RR = 1.10, p < 0.001). CONCLUSION: Patients with a psychiatric disorder required longer care and incurred greater costs, whereas mortality was higher for only those with a neurological disorder. Identifying patients' psychiatric comorbidities at the time of admission for trauma may help optimize treatment. Addressing these conditions may help reduce the cost of trauma care.

Enhancing Response Ability: Dietetics as a Vehicle for Social Justice-A Primer.

Recent world events have shone a spotlight on the social and structural injustices that impact the lives, health, and well-being of individuals and communities under threat. Dietitians should be well positioned to play a role in redressing injustice through their individual and collective "response abilities", that is, the combination of responsibility for and ability to be responsive to such injustices due to the varying privilege and power that dietitians have. However, recent research shows that dietitians report a lack of knowledge, skill, and confidence to take on such roles, and that dietetic education includes little knowledge- or skill-based learning that might prepare dietitians to do so. This primer aims to introduce readers to concepts that are fundamental to socially just dietetics practice, including privilege, structural competence, critical reflexivity, critical humility, and critical praxis. We assert that when implemented into practice and used to inform advocacy and activism these concepts enhance dietitians' individual and collective response ability to redress injustice.

LKB1 inactivation modulates chromatin accessibility to drive metastatic progression.

Metastasis is the leading cause of cancer-related deaths and enables cancer cells to compromise organ function by expanding in secondary sites. Since primary tumours and metastases often share the same constellation of driver mutations, the mechanisms that drive their distinct phenotypes are unclear. Here we show that inactivation of the frequently mutated tumour suppressor gene LKB1 (encoding liver kinase B1) has evolving effects throughout the progression of lung cancer, which leads to the differential epigenetic re-programming of early-stage primary tumours compared with late-stage metastases. By integrating genome-scale CRISPR-Cas9 screening with bulk and single-cell multi-omic analyses, we unexpectedly identify LKB1 as a master regulator of chromatin accessibility in lung adenocarcinoma primary tumours. Using an in vivo model of metastatic progression, we further show that loss of LKB1 activates the early endoderm transcription factor SOX17 in metastases and a metastatic-like sub-population of cancer cells within primary tumours. The expression of SOX17 is necessary and sufficient to drive a second wave of epigenetic changes in LKB1-deficient cells that enhances metastatic ability. Overall, our study demonstrates how the downstream effects of an individual driver mutation can change throughout cancer development, with implications for stage-specific therapeutic resistance mechanisms and the gene regulatory underpinnings of metastatic evolution.

Milestone Level Changes From Residency to Fellowship: A Multicenter Cohort Study.

BACKGROUND: A vital element of the Next Accreditation System is measuring and reporting educational Milestones. Little is known about changes in Milestones levels during the transition from residency to fellowship training. OBJECTIVE: Evaluate the Accreditation Council for Graduate Medical Education (ACGME) Milestones' ability to provide a linear trajectory of professional development from general pediatrics residency to neonatal-perinatal medicine (NPM) fellowship training. METHODS: We identified 11 subcompetencies that were the same for general pediatrics residency and NPM fellowship. We then extracted the last residency Milestone level and the first fellowship Milestone level for each subcompetency from the ACGME's Accreditation Data System on 89 subjects who started fellowship training between 2014 and 2018 at 6 NPM fellowship programs. Mixed-effects models were used to examine the intra-individual changes in Milestone scores between residency and fellowship after adjusting for the effects of the individual programs. RESULTS: A total of 1905 subcompetency Milestone levels were analyzed. The average first fellowship Milestone levels were significantly lower than the last residency Milestone levels (residency, mean 3.99 [SD = 0.48] vs fellowship 2.51 [SD = 0.56]; P < .001). Milestone levels decreased by an average of -1.49 (SD = 0.65) from the last residency to the first fellowship evaluation. Significant differences in Milestone levels were seen in both context-dependent subcompetencies (patient care and medical knowledge) and context-independent subcompetencies (professionalism). CONCLUSIONS: Contrary to providing a linear trajectory of professional development, we found that Milestone levels were reset when trainees transitioned from general pediatrics residency to NPM fellowship.