Epigenomic analysis of multilineage differentiation of human embryonic stem cells.

Epigenetic mechanisms have been proposed to play crucial roles in mammalian development, but their precise functions are only partially understood. To investigate epigenetic regulation of embryonic development, we differentiated human embryonic stem cells into mesendoderm, neural progenitor cells, trophoblast-like cells, and mesenchymal stem cells and systematically characterized DNA methylation, chromatin modifications, and the transcriptome in each lineage. We found that promoters that are active in early developmental stages tend to be CG rich and mainly engage H3K27me3 upon silencing in nonexpressing lineages. By contrast, promoters for genes expressed preferentially at later stages are often CG poor and primarily employ DNA methylation upon repression. Interestingly, the early developmental regulatory genes are often located in large genomic domains that are generally devoid of DNA methylation in most lineages, which we termed DNA methylation valleys (DMVs). Our results suggest that distinct epigenetic mechanisms regulate early and late stages of ES cell differentiation.

Health system assessment for access to care after injury in low- or middle-income countries: A mixed methods study from Northern Malawi.

BACKGROUND: Injuries represent a vast and relatively neglected burden of disease affecting low- and middle-income countries (LMICs). While many health systems underperform in treating injured patients, most assessments have not considered the whole system. We integrated findings from 9 methods using a 3 delays approach (delays in seeking, reaching, or receiving care) to prioritise important trauma care health system barriers in Karonga, Northern Malawi, and exemplify a holistic health system assessment approach applicable in comparable settings. METHODS AND FINDINGS: To provide multiple perspectives on each conceptual delay and include data from community-based and facility-based sources, we used 9 methods to examine the injury care health system. The methods were (1) household survey; (2) verbal autopsy analysis; (3) community focus group discussions (FGDs); (4) community photovoice; (5) facility care-pathway process mapping and elucidation of barriers following injury; (6) facility healthcare worker survey; (7) facility assessment survey; (8) clinical vignettes for care process quality assessment of facility-based healthcare workers; and (9) geographic information system (GIS) analysis. Empirical data collection took place in Karonga, Northern Malawi, between July 2019 and February 2020. We used a convergent parallel study design concurrently conducting all data collection before subsequently integrating results for interpretation. For each delay, a matrix was created to juxtapose method-specific data relevant to each barrier identified as driving delays to injury care. Using a consensus approach, we graded the evidence from each method as to whether an identified barrier was important within the health system. We identified 26 barriers to access timely quality injury care evidenced by at least 3 of the 9 study methods. There were 10 barriers at delay 1, 6 at delay 2, and 10 at delay 3. We found that the barriers "cost," "transport," and "physical resources" had the most methods providing strong evidence they were important health system barriers within delays 1 (seeking care), 2 (reaching care), and 3 (receiving care), respectively. Facility process mapping provided evidence for the greatest number of barriers-25 of 26 within the integrated analysis. There were some barriers with notable divergent findings between the community- and facility-based methods, as well as among different community- and facility-based methods, which are discussed. The main limitation of our study is that the framework for grading evidence strength for important health system barriers across the 9 studies was done by author-derived consensus; other researchers might have created a different framework. CONCLUSIONS: By integrating 9 different methods, including qualitative, quantitative, community-, patient-, and healthcare worker-derived data sources, we gained a rich insight into the functioning of this health system's ability to provide injury care. This approach allowed more holistic appraisal of this health system's issues by establishing convergence of evidence across the diverse methods used that the barriers of cost, transport, and physical resources were the most important health system barriers driving delays to seeking, reaching, and receiving injury care, respectively. This offers direction and confidence, over and above that derived from single methodology studies, for prioritising barriers to address through health service development and policy.

The development of inherited cardiac conditions services: current position and future perspectives.

BACKGROUND: Over the last two decades, inherited cardiac conditions (ICC) centres have emerged with the aim of improving outcomes for patients and their families, through early diagnosis, genetic testing, risk assessment and specialist treatment. SOURCES OF DATA: A literature search was performed using PubMed (https://pubmed.ncbi.nlm.nih.gov/). Commissioned ICC service reviews from NHS England, NHS Improvement and PHG Foundation were evaluated. AREAS OF AGREEMENT: ICC patient management requires a multi-disciplinary approach. ICC services are predominantly based within tertiary centres. Despite expansion, provision of care remains inadequate to meet rising demands. Access to services is inconsistent, partly due to geographic variation and lack of standardized pathways. AREAS OF CONTROVERSY: The optimal ICC care model remains undecided, although there is growing interest in 'hub-and-spoke' networks, which could aid secondary and tertiary service integration and repatriation of care. GROWING POINTS: Genetic mainstreaming is a priority for the Genomic Medicine Service Alliance. The benefits of telehealth and virtual clinics have been validated by their use during the COVID-19 pandemic. Other innovations to improve resource efficiency, such as clinical scientist-led and nurse-led clinics, show promise. AREAS TIMELY FOR DEVELOPING RESEARCH: An update for the NHS ICC service specifications is planned that appears well timed given the rapid evolution of the ICC landscape in the decade since last review. This has the potential to address needs including national audit, standardized pathways and ICC networks to improve governance and equity of care. Delegation of commissioning for specialist services to integrated care systems may also provide opportunity for increased regional direction.

Structural phenotyping in atrial fibrillation with combined cardiac CT and atrial MRI: Identifying and differentiating individual structural remodelling types in AF.

INTRODUCTION: Atrial remodelling (AR) is the persistent change in atrial structure and/or function and contributes to the initiation, maintenance and progression of atrial fibrillation (AF) in a reciprocal self-perpetuating relationship. Left atrial (LA) size, geometry, fibrosis, wall thickness (LAWT) and ejection fraction (LAEF) have all been shown to vary with pathological atrial remodelling. The association of these global remodelling markers with each other for differentiating structural phenotypes in AF is not well investigated. METHOD: Patients referred for first-time AF ablation and controls without AF were prospectively recruited to undergo cardiac computed tomographic angiography (CCTA) and magnetic resonance imaging (MRI) with 3D atrial late-gadolinium enhanced (LGE) sequences. LAWT, atrial myocardial mass, LA volume and sphericity were calculated from CT. Biplane LA EF and LA fibrosis burden were derived from atrial MRI. Results were compared between patients with AF and controls. RESULTS: Forty two AF patients (64.3% male, age 64.6 ± 10.2 years, CHA2DS2-VASc 2.48 ± 1.5, 69.0% paroxysmal AF, 31% persistent AF, LVEF 57.9 ± 10.5%) and 37 controls (64.9% male, age 56.6 ± 7.2, CHA2DS2-VASc 1.54 ± 1.1, LVEF 60.4 ± 4.9%) were recruited. Patients with AF had a significantly higher LAWT (1.45 ± 0.52 mm vs 1.12 ± 0.42 mm, p = 0.003), tissue mass (15.81 ± 6.53 g vs. 12.18 ± 5.01 g, p = 0.011), fibrosis burden (9.33 ± 8.35% vs 2.41 ± 3.60%, p = 0.013), left atrial size/volume (95.68 ± 26.63 mL vs 81.22 ± 20.64 mL, p = 0.011) and lower LAEF (50.3 ± 15.3% vs 65.2 ± 8.6%, p < 0.001) compared to controls. There was no significant correlation between % fibrosis with LAWT (p = 0.29), mass (p = 0.89), volume (p = 0.49) or sphericity (p = 0.79). LAWT had a statistically significant weak positive correlation with LA volume (r = 0.25, p = .041), but not with sphericity (p = 0.86). LAEF had a statistically significant but weak negative correlation with fibrosis (r = -0.33, p = 0.008) and LAWT (r = -0.24, p = 0.07). CONCLUSION: AF is associated with significant quantifiable structural changes that are evident in LA size, tissue thickness, total LA tissue mass and fibrosis. These individual remodelling markers do not or only weakly correlate with each other suggesting different remodelling subtypes exist (e.g. fibrotic vs hypertrophic vs dilated). If confirmed, such a detailed understanding of the structural changes observed has the potential to inform clinical management strategies targeting individual mechanisms underlying the disease process.

Consistency of ablations with trainee and increasing independence during fellowship training-Analysis of ablation data by CARTONET.

INTRODUCTION: Training in clinical cardiac electrophysiology (CCEP) involves the development of catheter handling skills to safely deliver effective treatment. Objective data from analysis of ablation data for evaluating trainee of CCEP procedures has not previously been possible. Using the artificial intelligence cloud-based system (CARTONET), we assessed the impact of trainee progress through ablation procedural quality. METHODS: Lesion- and procedure-level data from all de novo atrial fibrillation (AF) and cavotricuspid isthmus (CTI) ablations involving first-year (Y1) or second-year (Y2) fellows across a full year of fellowship was curated within Cartonet. Lesions were automatically assigned to anatomic locations. RESULTS: Lesion characteristics, including contact force, catheter stability, impedance drop, ablation index value, and interlesion time/distance were similar over each training year. Anatomic location and supervising operator significantly affected catheter stability. The proportion of lesion sets delivered independently and of lesions delivered by the trainee increased steadily from the first quartile of Y1 to the last quartile of Y2. Trainee perception of difficult regions did not correspond to objective measures. CONCLUSION: Objective ablation data from Cartonet showed that the progression of trainees through CCEP training does not impact lesion-level measures of treatment efficacy (i.e., catheter stability, impedance drop). Data demonstrates increasing independence over a training fellowship. Analyses like these could be useful to inform individualized training programs and to track trainee's progress. It may also be a useful quality assurance tool for ensuring ongoing consistency of treatment delivered within training institutions.

Access to quality care after injury in Northern Malawi: results of a household survey.

BACKGROUND: Most injury care research in low-income contexts such as Malawi is facility centric. Community-derived data is needed to better understand actual injury incidence, health system utilisation and barriers to seeking care following injury. METHODS: We administered a household survey to 2200 households in Karonga, Malawi. The primary outcome was injury incidence, with non-fatal injuries classified as major or minor (> 30 or 1-29 disability days respectively). Those seeking medical treatment were asked about time delays to seeking, reaching and receiving care at a facility, where they sought care, and whether they attended a second facility. We performed analysis for associations between injury severity and whether the patient sought care, stayed overnight in a facility, attended a second facility, or received care within 1 or 2 h. The reason for those not seeking care was asked. RESULTS: Most households (82.7%) completed the survey, with 29.2% reporting an injury. Overall, 611 non-fatal and four fatal injuries were reported from 531 households: an incidence of 6900 per 100,000. Major injuries accounted for 26.6%. Three quarters, 76.1% (465/611), sought medical attention. Almost all, 96.3% (448/465), seeking care attended a primary facility first. Only 29.7% (138/465), attended a second place of care. Only 32.0% (142/444), received care within one hour. A further 19.1% (85/444) received care within 2 h. Major injury was associated with being more likely to have; sought care (94.4% vs 69.8% p < 0.001), stayed overnight at a facility (22.9% vs 15.4% P = 0.047), attended a second place of care (50.3% vs 19.9%, P < 0.001). For those not seeking care the most important reason was the injury not being serious enough for 52.1% (74/142), followed by transport difficulties 13.4% (19/142) and financial costs 5.6% (8/142). CONCLUSION: Injuries in Northern Malawi are substantial. Community-derived details are necessary to fully understand injury burden and barriers to seeking and reaching care.

Computerized surgical navigation resection of pelvic region simulated bone tumors using skin fiducial marker registration: an in vitro cadaveric study.

INTRODUCTION: Computerized surgical navigation system guidance can improve bone tumor surgical resection accuracy. This study compared the 10-mm planned resection margin agreement between simulated pelvic-region bone tumors (SPBT) resected using either skin fiducial markers or Kirschner (K)-wires inserted directly into osseous landmarks with navigational system registration under direct observation. We hypothesized that skin fiducial markers would display similar resection margin accuracy. METHODS: Six cadaveric pelvises had one SPBT implanted into each supra-acetabular region. At the left hemi-pelvis, the skin fiducial marker group had guidance from markers placed over the pubic tubercle, the anterior superior iliac spine, the central and more posterior iliac crest, and the greater trochanter (5 markers). At the right hemi-pelvis, the K-wire group had guidance from 1.4-mm-diameter wires inserted into the pubic tubercle, and 3 inserted along the iliac crest (4 K-wires). The senior author, a fellowship-trained surgeon performed "en bloc" SPBT resections. The primary investigator, blinded to group assignment, measured actual resection margins. RESULTS: Twenty of 22 resection margins (91%) in the skin fiducial marker group were within the Bland-Altman plot 95% confidence interval for actual-planned margin mean difference (mean = -0.23 mm; 95% confidence intervals = 2.8 mm, - 3.3 mm). Twenty-one of 22 resection margins (95%) in the K-wire group were within the 95% confidence interval of actual-planned margin mean difference (mean = 0.26 mm; 95% confidence intervals = 1.7 mm, - 1.1 mm). CONCLUSION: Pelvic bone tumor resection with navigational guidance from skin fiducial markers placed over osseous landmarks provided similar accuracy to K-wires inserted into osseous landmarks. Further in vitro studies with different SPBT dimensions/locations and clinical studies will better delineate use efficacy.

Correction: Linking statistical shape models and simulated function in the healthy adult human heart.

[This corrects the article DOI: 10.1371/journal.pcbi.1008851.].

Optimization of anti-tachycardia pacing efficacy through scar-specific delivery and minimization of re-initiation: a virtual study on a cohort of infarcted porcine hearts.

AIMS: Anti-tachycardia pacing (ATP) is a reliable electrotherapy to painlessly terminate ventricular tachycardia (VT). However, ATP is often ineffective, particularly for fast VTs. The efficacy may be enhanced by optimized delivery closer to the re-entrant circuit driving the VT. This study aims to compare ATP efficacy for different delivery locations with respect to the re-entrant circuit, and further optimize ATP by minimizing failure through re-initiation. METHODS AND RESULTS: Seventy-three sustained VTs were induced in a cohort of seven infarcted porcine ventricular computational models, largely dominated by a single re-entrant pathway. The efficacy of burst ATP delivered from three locations proximal to the re-entrant circuit (septum) and three distal locations (lateral/posterior left ventricle) was compared. Re-initiation episodes were used to develop an algorithm utilizing correlations between successive sensed electrogram morphologies to automatically truncate ATP pulse delivery. Anti-tachycardia pacing was more efficacious at terminating slow compared with fast VTs (65 vs. 46%, P = 0.000039). A separate analysis of slow VTs showed that the efficacy was significantly higher when delivered from distal compared with proximal locations (distal 72%, proximal 59%), being reversed for fast VTs (distal 41%, proximal 51%). Application of our early termination detection algorithm (ETDA) accurately detected VT termination in 79% of re-initiated cases, improving the overall efficacy for proximal delivery with delivery inside the critical isthmus (CI) itself being overall most effective. CONCLUSION: Anti-tachycardia pacing delivery proximal to the re-entrant circuit is more effective at terminating fast VTs, but less so slow VTs, due to frequent re-initiation. Attenuating re-initiation, through ETDA, increases the efficacy of delivery within the CI for all VTs.

Additional coils mitigate elevated defibrillation threshold in right-sided implantable cardioverter defibrillator generator placement: a simulation study.

AIMS: The standard implantable cardioverter defibrillator (ICD) generator (can) is placed in the left pectoral area; however, in certain circumstances, right-sided cans may be required which may increase defibrillation threshold (DFT) due to suboptimal shock vectors. We aim to quantitatively assess whether the potential increase in DFT of right-sided can configurations may be mitigated by alternate positioning of the right ventricular (RV) shocking coil or adding coils in the superior vena cava (SVC) and coronary sinus (CS). METHODS AND RESULTS: A cohort of CT-derived torso models was used to assess DFT of ICD configurations with right-sided cans and alternate positioning of RV shock coils. Efficacy changes with additional coils in the SVC and CS were evaluated. A right-sided can with an apical RV shock coil significantly increased DFT compared to a left-sided can [19.5 (16.4, 27.1) J vs. 13.3 (11.7, 19.9) J, P < 0.001]. Septal positioning of the RV coil led to a further DFT increase when using a right-sided can [26.7 (18.1, 36.1) J vs. 19.5 (16.4, 27.1) J, P < 0.001], but not a left-sided can [12.1 (8.1, 17.6) J vs. 13.3 (11.7, 19.9) J, P = 0.099). Defibrillation threshold of a right-sided can with apical or septal coil was reduced the most by adding both SVC and CS coils [19.5 (16.4, 27.1) J vs. 6.6 (3.9, 9.9) J, P < 0.001, and 26.7 (18.1, 36.1) J vs. 12.1 (5.7, 13.5) J, P < 0.001]. CONCLUSION: Right-sided, compared to left-sided, can positioning results in a 50% increase in DFT. For right-sided cans, apical shock coil positioning produces a lower DFT than septal positions. Elevated right-sided can DFTs may be mitigated by utilizing additional coils in SVC and CS.

Non-invasive localization of post-infarct ventricular tachycardia exit sites to guide ablation planning: a computational deep learning platform utilizing the 12-lead electrocardiogram and intracardiac electrograms from implanted devices.

AIMS: Existing strategies that identify post-infarct ventricular tachycardia (VT) ablation target either employ invasive electrophysiological (EP) mapping or non-invasive modalities utilizing the electrocardiogram (ECG). Their success relies on localizing sites critical to the maintenance of the clinical arrhythmia, not always recorded on the 12-lead ECG. Targeting the clinical VT by utilizing electrograms (EGM) recordings stored in implanted devices may aid ablation planning, enhancing safety and speed and potentially reducing the need of VT induction. In this context, we aim to develop a non-invasive computational-deep learning (DL) platform to localize VT exit sites from surface ECGs and implanted device intracardiac EGMs. METHODS AND RESULTS: A library of ECGs and EGMs from simulated paced beats and representative post-infarct VTs was generated across five torso models. Traces were used to train DL algorithms to localize VT sites of earliest systolic activation; first tested on simulated data and then on a clinically induced VT to show applicability of our platform in clinical settings. Localization performance was estimated via localization errors (LEs) against known VT exit sites from simulations or clinical ablation targets. Surface ECGs successfully localized post-infarct VTs from simulated data with mean LE = 9.61 ± 2.61 mm across torsos. VT localization was successfully achieved from implanted device intracardiac EGMs with mean LE = 13.10 ± 2.36 mm. Finally, the clinically induced VT localization was in agreement with the clinical ablation volume. CONCLUSION: The proposed framework may be utilized for direct localization of post-infarct VTs from surface ECGs and/or implanted device EGMs, or in conjunction with efficient, patient-specific modelling, enhancing safety and speed of ablation planning.

Non-Invasive Diagnosis of Sun Damaged Skin: Actinic Keratosis Vs Squamous Cell Carcinoma.

IMPORTANCE: Actinic keratosis (AK) is a premalignant lesion that has a1% to 10% potential of progression to squamous cell carcinoma (SCC), but it is not possible to determine which lesions are at higher risk. OBJECTIVE: This study examined the epidermal genetic profiles of actinic keratosis and SCC through non-invasive techniques seeking to develop a biopsy-free method for AK monitoring and aid in the early diagnosis of developing SCC. DESIGN: Ribonucleic acid (RNA) was collected from adhesive tape strips and gene expression levels were measured. A threshold fold change >2 and adjusted P-value <0.05 were used to determine differentially expressed genes. SETTING: Single center dermatology clinic. PARTICIPANTS: Patients who presented to the clinic with lesions suspicious of non-melanoma skin cancer that had never been previously biopsied. MAIN OUTCOME AND MEASURE: RNA was extracted via non-invasive biopsy and sequenced. Low quality samples were filtered out and the remaining samples underwent differential gene expression analysis by DESeq2 in R package. A threshold of fold change >2 and adjusted P-value <0.05 was used for determination of differentially expressed genes. The differentially expressed genes that overlapped between the corrected and uncorrected groups were the most significant for analysis. RESULTS: From 47 lesions, 6 significant differentially expressed genes were found between AK and SCC, and 25 significant differentially expressed genes between in-situ SCC and invasive SCC. Individual samples showed similarities based on diagnosis, suggesting mutations were specific to the disease and not the individual. CONCLUSIONS AND RELEVANCE: These findings highlight which genes may play a role in AK progression to SCC. The genomic differences between in-situ and invasive squamous cell carcinoma open an opportunity for early diagnosis of squamous cell carcinoma and risk prediction of actinic keratosis. J Drugs Dermatol. 2023;22(5): doi:10.36849/JDD.7097.

Linking statistical shape models and simulated function in the healthy adult human heart.

Cardiac anatomy plays a crucial role in determining cardiac function. However, there is a poor understanding of how specific and localised anatomical changes affect different cardiac functional outputs. In this work, we test the hypothesis that in a statistical shape model (SSM), the modes that are most relevant for describing anatomy are also most important for determining the output of cardiac electromechanics simulations. We made patient-specific four-chamber heart meshes (n = 20) from cardiac CT images in asymptomatic subjects and created a SSM from 19 cases. Nine modes captured 90% of the anatomical variation in the SSM. Functional simulation outputs correlated best with modes 2, 3 and 9 on average (R = 0.49 ± 0.17, 0.37 ± 0.23 and 0.34 ± 0.17 respectively). We performed a global sensitivity analysis to identify the different modes responsible for different simulated electrical and mechanical measures of cardiac function. Modes 2 and 9 were the most important for determining simulated left ventricular mechanics and pressure-derived phenotypes. Mode 2 explained 28.56 ± 16.48% and 25.5 ± 20.85, and mode 9 explained 12.1 ± 8.74% and 13.54 ± 16.91% of the variances of mechanics and pressure-derived phenotypes, respectively. Electrophysiological biomarkers were explained by the interaction of 3 ± 1 modes. In the healthy adult human heart, shape modes that explain large portions of anatomical variance do not explain equivalent levels of electromechanical functional variation. As a result, in cardiac models, representing patient anatomy using a limited number of modes of anatomical variation can cause a loss in accuracy of simulated electromechanical function.

Epigenomic analysis reveals DNA motifs regulating histone modifications in human and mouse.

Histones are modified by enzymes that act in a locus, cell-type, and developmental stage-specific manner. The recruitment of enzymes to chromatin is regulated at multiple levels, including interaction with sequence-specific DNA-binding factors. However, the DNA-binding specificity of the regulatory factors that orchestrate specific histone modifications has not been broadly mapped. We have analyzed 6 histone marks (H3K4me1, H3K4me3, H3K27ac, H3K27me3, K3H9me3, H3K36me3) across 121 human cell types and tissues from the NIH Roadmap Epigenomics Project as well as 8 histone marks (with addition of H3K4me2 and H3K9ac) from the mouse ENCODE Consortium. We have identified 361 and 369 DNA motifs in human and mouse, respectively, that are the most predictive of each histone mark. Interestingly, 107 human motifs are conserved between the two species. In human embryonic cell line H1, we mutated only the found DNA motifs at particular loci and the significant reduction of H3K27ac levels validated the regulatory roles of the perturbed motifs. The functionality of these motifs was also supported by the evidence that histone-associated motifs, especially H3K4me3 motifs, significantly overlap with the expression of quantitative trait loci SNPs in cancer patients more than the known and random motifs. Furthermore, we observed possible feedbacks to control chromatin dynamics as the found motifs appear in the promoters or enhancers associated with various histone modification enzymes. These results pave the way toward revealing the molecular mechanisms of epigenetic events, such as histone modification dynamics and epigenetic priming.

Histologic Evaluation of the Triceps Brachii Tendon Insertion: Implications for Triceps-Sparing Surgery.

PURPOSE: Triceps detachment and olecranon osteotomy are 2 techniques used to enhance exposure in elbow surgery. Both the techniques can potentially add considerable morbidity and lengthen the recovery after surgery. Triceps-sparing surgery can potentially mitigate those issues. The purpose of this study was to evaluate the triceps tendon insertion at a histologic level to help improve triceps-sparing surgical techniques used in elbow trauma and arthroplasty. METHODS: Seventeen fresh-frozen cadaveric elbow specimens were collected. The olecranon and its soft tissue attachments were isolated. We performed gross measurements and sectioned the specimens for histologic evaluation in the saggital or coronal planes. The proximal-to-distal and medial-to-lateral dimensions of the tendon and the distance from the proximal tip of the olecranon to the proximal tendon insertion were measured microscopically on stained embedded sections. RESULTS: The proximal-to-distal dimension of the triceps tendon insertion was less than previously reported, whereas the medial-to-lateral dimension was similar. The true distance from the tip of the olecranon to the proximal tendon insertion was greater than the previously reported distance obtained via gross measurement. CONCLUSIONS: Gross measurement of the triceps tendon insertion overestimates and inaccurately represents the true insertional footprint. Gross measurement has been shown to demonstrate consistent disparity compared with histologic measurement. Histologic investigation provides a more accurate description. CLINICAL RELEVANCE: The finding that the distance from the articular tip of the olecranon to the proximal tendon insertion is greater than previously reported may have clinical implications. A triceps split approach may allow more visualization and exposure of the posterior joint and, therefore, lessen the need for triceps detachment or olecranon osteotomy.

Human body epigenome maps reveal noncanonical DNA methylation variation.

Understanding the diversity of human tissues is fundamental to disease and requires linking genetic information, which is identical in most of an individual's cells, with epigenetic mechanisms that could have tissue-specific roles. Surveys of DNA methylation in human tissues have established a complex landscape including both tissue-specific and invariant methylation patterns. Here we report high coverage methylomes that catalogue cytosine methylation in all contexts for the major human organ systems, integrated with matched transcriptomes and genomic sequence. By combining these diverse data types with each individuals' phased genome, we identified widespread tissue-specific differential CG methylation (mCG), partially methylated domains, allele-specific methylation and transcription, and the unexpected presence of non-CG methylation (mCH) in almost all human tissues. mCH correlated with tissue-specific functions, and using this mark, we made novel predictions of genes that escape X-chromosome inactivation in specific tissues. Overall, DNA methylation in several genomic contexts varies substantially among human tissues.

Integrative analysis of 111 reference human epigenomes.

The reference human genome sequence set the stage for studies of genetic variation and its association with human disease, but epigenomic studies lack a similar reference. To address this need, the NIH Roadmap Epigenomics Consortium generated the largest collection so far of human epigenomes for primary cells and tissues. Here we describe the integrative analysis of 111 reference human epigenomes generated as part of the programme, profiled for histone modification patterns, DNA accessibility, DNA methylation and RNA expression. We establish global maps of regulatory elements, define regulatory modules of coordinated activity, and their likely activators and repressors. We show that disease- and trait-associated genetic variants are enriched in tissue-specific epigenomic marks, revealing biologically relevant cell types for diverse human traits, and providing a resource for interpreting the molecular basis of human disease. Our results demonstrate the central role of epigenomic information for understanding gene regulation, cellular differentiation and human disease.

Identification of DNA motifs that regulate DNA methylation.

DNA methylation is an important epigenetic mark but how its locus-specificity is decided in relation to DNA sequence is not fully understood. Here, we have analyzed 34 diverse whole-genome bisulfite sequencing datasets in human and identified 313 motifs, including 92 and 221 associated with methylation (methylation motifs, MMs) and unmethylation (unmethylation motifs, UMs), respectively. The functionality of these motifs is supported by multiple lines of evidence. First, the methylation levels at the MM and UM motifs are respectively higher and lower than the genomic background. Second, these motifs are enriched at the binding sites of methylation modifying enzymes including DNMT3A and TET1, indicating their possible roles of recruiting these enzymes. Third, these motifs significantly overlap with "somatic QTLs" (quantitative trait loci) of methylation and expression. Fourth, disruption of these motifs by mutation is associated with significantly altered methylation level of the CpGs in the neighbor regions. Furthermore, these motifs together with somatic mutations are predictive of cancer subtypes and patient survival. We revealed some of these motifs were also associated with histone modifications, suggesting a possible interplay between the two types of epigenetic modifications. We also found some motifs form feed forward loops to contribute to DNA methylation dynamics.

FASt single-breathhold 2D multislice myocardial T1 mapping (FAST1) at 1.5T for full left ventricular coverage in three breathholds.

BACKGROUND: Conventional myocardial T1 mapping techniques such as modified Look-Locker inversion recovery (MOLLI) generate one T1 map per breathhold. T1 mapping with full left ventricular coverage may be desirable when spatial T1 variations are expected. This would require multiple breathholds, increasing patient discomfort and prolonging scan time. PURPOSE: To develop and characterize a novel FASt single-breathhold 2D multislice myocardial T1 mapping (FAST1) technique for full left ventricular coverage. STUDY TYPE: Prospective. POPULATION/PHANTOM: Numerical simulation, agarose/NiCl2 phantom, 9 healthy volunteers, and 17 patients. FIELD STRENGTH/SEQUENCE: 1.5T/FAST1. ASSESSMENT: Two FAST1 approaches, FAST1-BS and FAST1-IR, were characterized and compared with standard 5-(3)-3 MOLLI in terms of accuracy, precision/spatial variability, and repeatability. STATISTICAL TESTS: Kruskal-Wallis, Wilcoxon signed rank tests, intraclass correlation coefficient analysis, analysis of variance, Student's t-tests, Pearson correlation analysis, and Bland-Altman analysis. RESULTS: In simulation/phantom, FAST1-BS, FAST1-IR, and MOLLI had an accuracy (expressed as T1 error) of 0.2%/4%, 6%/9%, and 4%/7%, respectively, while FAST1-BS and FAST1-IR had a precision penalty of 1.7/1.5 and 1.5/1.4 in comparison with MOLLI, respectively. In healthy volunteers, FAST1-BS/FAST1-IR/MOLLI led to different native myocardial T1 times (1016 ± 27 msec/952 ±22 msec/987 ± 23 msec, P < 0.0001) and spatial variability (66 ± 10 msec/57 ± 8 msec/46 ± 7 msec, P < 0.001). There were no statistically significant differences between all techniques for T1 repeatability (P = 0.18). In vivo native and postcontrast myocardial T1 times in both healthy volunteers and patients using FAST1-BS/FAST1-IR were highly correlated with MOLLI (Pearson correlation coefficient ≥0.93). DATA CONCLUSION: FAST1 enables myocardial T1 mapping with full left ventricular coverage in three separated breathholds. In comparison with MOLLI, FAST1 yield a 5-fold increase of spatial coverage, limited penalty of T1 precision/spatial variability, no significant difference of T1 repeatability, and highly correlated T1 times. FAST1-IR provides improved T1 precision/spatial variability but reduced accuracy when compared with FAST1-BS. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2020;51:492-504.

Identifying, Prioritizing and Visually Mapping Barriers to Injury Care in Rwanda: A Multi-disciplinary Stakeholder Exercise.

BACKGROUND: Whilst injuries are a major cause of disability and death worldwide, a large proportion of people in low- and middle-income countries lack timely access to injury care. Barriers to accessing care from the point of injury to return to function have not been delineated. METHODS: A two-day workshop was held in Kigali, Rwanda in May 2019 with representation from health providers, academia, and government. A four delays model (delays to seeking, reaching, receiving, and remaining in care) was applied to injury care. Participants identified barriers at each delay and graded, through consensus, their relative importance. Following an iterative voting process, the four highest priority barriers were identified. Based on workshop findings and a scoping review, a map was created to visually represent injury care access as a complex health-system problem. RESULTS: Initially, 42 barriers were identified by the 34 participants. 19 barriers across all four delays were assigned high priority; highest-priority barriers were "Training and retention of specialist staff", "Health education/awareness of injury severity", "Geographical coverage of referral trauma centres", and "Lack of protocol for bypass to referral centres". The literature review identified evidence relating to 14 of 19 high-priority barriers. Most barriers were mapped to more than one of the four delays, visually represented in a complex health-system map. CONCLUSION: Overcoming barriers to ensure access to quality injury care requires a multifaceted approach which considers the whole patient journey from injury to rehabilitation. Our results can guide researchers and policymakers planning future interventions.