Context-Specific Stress Causes Compartmentalized SARM1 Activation and Local Degeneration in Cortical Neurons.

Sterile alpha and TIR motif containing 1 (SARM1) is an inducible NADase that localizes to mitochondria throughout neurons and senses metabolic changes that occur after injury. Minimal proteomic changes are observed upon either SARM1 depletion or activation, suggesting that SARM1 does not exert broad effects on neuronal protein homeostasis. However, whether SARM1 activation occurs throughout the neuron in response to injury and cell stress remains largely unknown. Using a semiautomated imaging pipeline and a custom-built deep learning scoring algorithm, we studied degeneration in both mixed-sex mouse primary cortical neurons and male human-induced pluripotent stem cell-derived cortical neurons in response to a number of different stressors. We show that SARM1 activation is differentially restricted to specific neuronal compartments depending on the stressor. Cortical neurons undergo SARM1-dependent axon degeneration after mechanical transection, and SARM1 activation is limited to the axonal compartment distal to the injury site. However, global SARM1 activation following vacor treatment causes both cell body and axon degeneration. Context-specific stressors, such as microtubule dysfunction and mitochondrial stress, induce axonal SARM1 activation leading to SARM1-dependent axon degeneration and SARM1-independent cell body death. Our data reveal that compartment-specific SARM1-mediated death signaling is dependent on the type of injury and cellular stressor.

Size-reduced embryos reveal a gradient scaling-based mechanism for zebrafish somite formation.

Little is known about how the sizes of animal tissues are controlled. A prominent example is somite size, which varies widely both within an individual and across species. Despite intense study of the segmentation clock governing the timing of somite generation, how it relates to somite size is poorly understood. Here, we examine somite scaling and find that somite size at specification scales with the length of the presomitic mesoderm (PSM) despite considerable variation in PSM length across developmental stages and in surgically size-reduced embryos. Measurement of clock period, axis elongation speed and clock gene expression patterns demonstrate that existing models fail to explain scaling. We posit a 'clock and scaled gradient' model, in which somite boundaries are set by a dynamically scaling signaling gradient across the PSM. Our model not only explains existing data, but also makes a unique prediction that we confirm experimentally - the formation of periodic 'echoes' in somite size following perturbation of the size of one somite. Our findings demonstrate that gradient scaling plays a central role in both progression and size control of somitogenesis.

ARHGAP18 Protects Against Thoracic Aortic Aneurysm Formation by Mitigating the Synthetic and Proinflammatory Smooth Muscle Cell Phenotype.

RATIONALE: Thoracic aortic aneurysm (TAA) is a potentially lethal condition, which can affect individuals of all ages. TAA may be complicated by the sudden onset of life-threatening dissection or rupture. The underlying mechanisms leading to TAA formation, particularly in the nonsyndromal idiopathic group of patients, are not well understood. Thus, identification of new genes and targets that are involved in TAA pathogenesis are required to help prevent and reverse the disease phenotype. OBJECTIVE: Here we explore the role of ARHGAP18, a novel Rho GAP expressed by smooth muscle cells (SMCs), in the pathogenesis of TAA. METHODS AND RESULTS: Using human and mouse aortic samples, we report that ARHGAP18 levels were significantly reduced in the SMC layer of aortic aneurysms. Arhgap18 global knockout (Arhgap18-/-) mice exhibited a highly synthetic, proteolytic, and proinflammatory smooth muscle phenotype under basal conditions and when challenged with angiotensin II, developed TAA with increased frequency and severity compared with littermate controls. Chromatin immunoprecipitation studies revealed this phenotype is partly associated with strong enrichment of H3K4me3 and depletion of H3K27me3 at the MMP2 and TNF-α promoters in Arhgap18-deficient SMC. We further show that TAA formation in the Arhgap18-/- mice is associated with loss of Akt activation. The abnormal SMC phenotype observed in the Arhgap18-/- mice can be partially rescued by pharmacological treatment with the mTORC1 inhibitor rapamycin, which reduces the synthetic and proinflammatory phenotype of Arhgap18-deficient SMC. CONCLUSION: We have identified ARHGAP18 as a novel protective gene against TAA formation and define an additional target for the future development of treatments to limit TAA pathogenesis.

Birth "Out-of-Hours": An Evaluation of Obstetric Practice and Outcome According to the Presence of Senior Obstetricians on the Labour Ward.

BACKGROUND: Concerns have been raised that a lack of senior obstetricians ("consultants") on the labour ward outside normal hours may lead to worse outcomes among babies born during periods of reduced cover. METHODS AND FINDINGS: We carried out a multicentre cohort study using data from 19 obstetric units in the United Kingdom between 1 April 2012 and 31 March 2013 to examine whether rates of obstetric intervention and outcome change "out-of-hours," i.e., when consultants are not providing dedicated, on-site labour ward cover. At the 19 hospitals, obstetric rotas ranged from 51 to 106 h of on-site labour ward cover per week. There were 87,501 singleton live births during the year, and 55.8% occurred out-of-hours. Women who delivered out-of-hours had slightly lower rates of intrapartum caesarean section (CS) (12.7% versus 13.4%, adjusted odds ratio [OR] 0.94; 95% confidence interval [CI] 0.90 to 0.98) and instrumental delivery (15.6% versus 17.0%, adj. OR 0.92; 95% CI 0.89 to 0.96) than women who delivered at times of on-site labour ward cover. There was some evidence that the severe perineal tear rate was reduced in out-of-hours vaginal deliveries (3.3% versus 3.6%, adj. OR 0.92; 95% CI 0.85 to 1.00). There was no evidence of a statistically significant difference between out-of-hours and "in-hours" deliveries in the rate of babies with a low Apgar score at 5 min (1.33% versus 1.25%, adjusted OR 1.07; 95% CI 0.95 to 1.21) or low cord pH (0.94% versus 0.82%; adjusted OR 1.12; 95% CI 0.96 to 1.31). Key study limitations include the potential for bias by indication, the reliance upon an organisational measure of consultant presence, and a non-random sample of maternity units. CONCLUSIONS: There was no difference in the rate of maternal and neonatal morbidity according to the presence of consultants on the labour ward, with the possible exception of a reduced rate of severe perineal tears in out-of-hours vaginal deliveries. Fewer women had operative deliveries out-of-hours. Taken together, the available evidence provides some reassurance that the current organisation of maternity care in the UK allows for good planning and risk management. However there is a need for more robust evidence on the quality of care afforded by different models of labour ward staffing.

Forming giant vesicles with controlled membrane composition, asymmetry, and contents.

Growing knowledge of the key molecular components involved in biological processes such as endocytosis, exocytosis, and motility has enabled direct testing of proposed mechanistic models by reconstitution. However, current techniques for building increasingly complex cellular structures and functions from purified components are limited in their ability to create conditions that emulate the physical and biochemical constraints of real cells. Here we present an integrated method for forming giant unilamellar vesicles with simultaneous control over (i) lipid composition and asymmetry, (ii) oriented membrane protein incorporation, and (iii) internal contents. As an application of this method, we constructed a synthetic system in which membrane proteins were delivered to the outside of giant vesicles, mimicking aspects of exocytosis. Using confocal fluorescence microscopy, we visualized small encapsulated vesicles docking and mixing membrane components with the giant vesicle membrane, resulting in exposure of previously encapsulated membrane proteins to the external environment. This method for creating giant vesicles can be used to test models of biological processes that depend on confined volume and complex membrane composition, and it may be useful in constructing functional systems for therapeutic and biomaterials applications.

Four countries, four ways of discussing low-risk pregnancy and normal delivery: in France, Germany, The Netherlands, and the United Kingdom.

The 2012 "4 countries meeting" of the French, Dutch, British and German Societies of Gynaecology and Obstetrics (CNGOF, NVOG, RCOG, DGGG) was dedicated to the topic "Low-risk pregnancy and normal delivery". The objective was to compare how each country organises prenatal care and normal delivery. The discussion is outlined in the article and provides new opportunities to learn from each other's strengths in order to provide the highest level of care regardless of social, demographic, educational and clinical differences.

Evaluating maternity care using national administrative health datasets: how are statistics affected by the quality of data on method of delivery?

BACKGROUND: Information on maternity services is increasingly derived from national administrative health data. We evaluated how statistics on maternity care in England were affected by the completeness and consistency of data on "method of delivery" in a national dataset. METHODS: Singleton deliveries occurring between April 2009 and March 2010 in English NHS trusts were extracted from the Hospital Episode Statistics (HES) database. In HES, method of delivery can be entered twice: 1) as a procedure code in core fields, and 2) in supplementary maternity fields. We examined overall consistency of these data sources at a national level and among individual trusts. The impact of different analysis rules for handling inconsistent data was then examined using three maternity statistics: emergency caesarean section (CS) rate; third/fourth degree tear rate amongst instrumental deliveries, and elective CS rate for breech presentation. RESULTS: We identified 629,049 singleton deliveries. Method of delivery was not entered as a procedure or in the supplementary fields in 0.8% and 12.5% of records, respectively. In 545,594 records containing both data items, method of delivery was coded consistently in 96.3% (kappa = 0.93; p < 0.001). Eleven of 136 NHS trusts had comparatively poor consistency (<92%) suggesting systematic data entry errors. The different analysis rules had a small effect on the statistics at a national level but the effect could be substantial for individual NHS trusts. The elective CS rate for breech was most sensitive to the chosen analysis rule. CONCLUSIONS: Organisational maternity statistics are sensitive to inconsistencies in data on method of delivery, and publications of quality indicators should describe how such data were handled. Overall, method of delivery is coded consistently in English administrative health data.

Rare non-synonymous variations in the transcriptional activation domains of GATA5 in bicuspid aortic valve disease.

Bicuspid aortic valve (BAV) is the commonest congenital heart disease and a highly heritable trait; however, only the NOTCH1 gene has been linked to limited cases of BAV in humans. Recently, the transcription factor GATA5 has been shown to have an essential role in aortic valve development, and targeted deletion of Gata5 in mice is associated with partially penetrant BAV formation. Here, we investigated the relationship between GATA5 gene variants and BAV with its associated aortopathy. One hundred unrelated individuals with confirmed BAV were prospectively recruited. Following collection of clinical information and DNA extraction, the coding regions and splice signal sequences of the GATA5 gene were screened for sequence variations. The clinical characteristics of the cohort included a male predominance (77%), mean age of diagnosis 29 ± 22 years, associated aortopathy in 59% and positive family history for BAV in 13%. Genetic analysis identified the presence of 4 rare non-synonymous variations within the GATA5 transcriptional activation domains, namely Gln3Arg, Ser19Trp, Tyr142His and Gly166Ser, occurring in one patient each. Gln3Arg and Tyr142His substitutions affect highly conserved and functionally relevant residues, and are likely to impact on the transcriptional activation of GATA5 target regions. A novel Ser19Trp variation was identified at a highly conserved amino acid residue in one patient, while the Gly166Ser variant was found in a familial case of BAV and associated aortopathy. Rare non-synonymous variations in the functionally important GATA5 transcriptional activation domains may be important in the pathogenesis of BAV disease in humans.

Development and validation of a time-dependent risk model for predicting mortality in infective endocarditis.

AIMS: Existing risk models in infective endocarditis (IE) have not investigated whether the prognostic value of clinical parameters is time-dependent. We have explored the potential of time-dependent risk stratification to predict outcome in IE. METHODS AND RESULTS: We studied 273 patients admitted with IE to two centres (derivation cohort n=192, validation cohort n=81). The derivation cohort was used to identify independent predictors of 6 months mortality at days 1, 8, and 15 (multivariable Cox regression, P<0.05). There were six predictors at day 1, five at day 8, and only three at day 15. Whereas heart failure, thrombocytopenia, and severe comorbidity predicted mortality at all three time-points, other predictors were time-dependent (age, tachycardia, renal impairment at day 1; severe embolic events, renal impairment at day 8). These predictors were incorporated into a time-dependent model. The model was validated in an independent cohort with concordance indices of 0.79 (95% CI 0.68-0.91) at day 1, 0.79 (95% CI 0.65-0.93) at day 8, and 0.84 (95% CI 0.73-0.95) at day 15. Six months mortality was 2.4% in patients deemed as low-risk at all time-points, compared with 78.2% in patients classified as high-risk at any evaluation. CONCLUSION: Prognostic factors in IE are time-dependent. Time-dependent risk stratification accurately predicts outcome in IE.

The role of genetic testing in diagnosis and care of inherited cardiac conditions in a specialised multidisciplinary clinic.

BACKGROUND: The diagnostic yield of genetic testing for inherited cardiac diseases is up to 40% and is primarily indicated for screening of at-risk relatives. Here, we evaluate the role of genomics in diagnosis and management among consecutive individuals attending a specialised clinic and identify those with the highest likelihood of having a monogenic disease. METHODS: A retrospective audit of 1697 consecutive, unrelated probands referred to a specialised, multidisciplinary clinic between 2002 and 2020 was performed. A concordant clinical and genetic diagnosis was considered solved. Cases were classified as likely monogenic based on a score comprising a positive family history, young age at onset, and severe phenotype, whereas low-scoring cases were considered to have a likely complex aetiology. The impact of a genetic diagnosis was evaluated. RESULTS: A total of 888 probands fulfilled the inclusion criteria, and genetic testing identified likely pathogenic or pathogenic (LP/P) variants in 330 individuals (37%) and suspicious variants of uncertain significance (VUS) in 73 (8%). Research-focused efforts identified 46 (5%) variants, missed by conventional genetic testing. Where a variant was identified, this changed or clarified the final diagnosis in a clinically useful way for 51 (13%). The yield of suspicious VUS across ancestry groups ranged from 15 to 20%, compared to only 10% among Europeans. Even when the clinical diagnosis was uncertain, those with the most monogenic disease features had the greatest diagnostic yield from genetic testing. CONCLUSIONS: Research-focused efforts can increase the diagnostic yield by up to 5%. Where a variant is identified, this will have clinical utility beyond family screening in 13%. We demonstrate the value of genomics in reaching an overall diagnosis and highlight inequities based on ancestry. Acknowledging our incomplete understanding of disease phenotypes, we propose a framework for prioritising likely monogenic cases to solve their underlying cause of disease.

Models of cardiovascular surgery biobanking to facilitate translational research and precision medicine.

Biobanking in health care has evolved over the last few decades from simple biological sample repositories to complex and dynamic units with multi-organizational infrastructure networks and has become an essential tool for modern medical research. Cardiovascular tissue biobanking provides a unique opportunity to utilize cardiac and vascular samples for translational research into heart failure and other related pathologies. Current techniques for diagnosis, classification, and treatment monitoring of cardiac disease relies primarily on interpretation of clinical signs, imaging, and blood biomarkers. Further research at the disease source (i.e. myocardium and blood vessels) has been limited by a relative lack of access to quality human cardiac tissue and the inherent shortcomings of most animal models of heart disease. In this review, we describe a model for cardiovascular tissue biobanking and databasing, and its potential to facilitate basic and translational research. We share techniques to procure endocardial samples from patients with hypertrophic cardiomyopathy, heart failure with reduced ejection fraction, and heart failure with preserved ejection fraction, in addition to aortic disease samples. We discuss some of the issues with respect to data collection, privacy, biobank consent, and the governance of tissue biobanking. The development of tissue biobanks as described here has significant scope to improve and facilitate translational research in multi-omic fields such as genomics, transcriptomics, proteomics, and metabolomics. This research heralds an era of precision medicine, in which patients with cardiovascular pathology can be provided with optimized and personalized medical care for the treatment of their individual phenotype.

Unilamellar vesicle formation and encapsulation by microfluidic jetting.

Compartmentalization of biomolecules within lipid membranes is a fundamental requirement of living systems and an essential feature of many pharmaceutical therapies. However, applications of membrane-enclosed solutions of proteins, DNA, and other biologically active compounds have been limited by the difficulty of forming unilamellar vesicles with controlled contents in a repeatable manner. Here, we demonstrate a method for simultaneously creating and loading giant unilamellar vesicles (GUVs) using a pulsed microfluidic jet. Akin to blowing a bubble, the microfluidic jet deforms a planar lipid bilayer into a vesicle that is filled with solution from the jet and separates from the planar bilayer. In contrast with existing techniques, our method rapidly generates multiple monodisperse, unilamellar vesicles containing solutions of unrestricted composition and molecular weight. Using the microfluidic jetting technique, we demonstrate repeatable encapsulation of 500-nm particles into GUVs and show that functional pore proteins can be incorporated into the vesicle membrane to mediate transport. The ability of microfluidic jetting to controllably encapsulate solutions inside of GUVs creates new opportunities for the study and use of compartmentalized biomolecular systems in science, industry, and medicine.

Long term clinical outcomes associated with CMR quantified isolated left ventricular non-compaction in adults.

BACKGROUND: Left ventricular non-compaction (LVNC) is a complex clinical condition with several diagnostic criteria but no diagnostic gold standard. We aimed to evaluate our thresholding technique in a group of patients with LVNC and assess the risk of major adverse cardiovascular and cerebrovascular events (MACCE). METHODS: We retrospectively analyzed cardiac magnetic resonance (CMR) scans of patients with Petersen criteria LVNC and quantified noncompacted myocardial mass. We assessed the association of noncompacted myocardial mass, CMR derived LV volumetric parameters and late gadolinium enhancement (LGE) to MACCE including cardiac death, cardiac transplantation, sustained ventricular tachycardia/ventricular fibrillation (VT/VF) and ischemic stroke. Patients with known genetic mutations and cardiovascular disease were excluded. RESULTS: 98 patients with LVNC were included (55 males,56.7%); 17(17.3%) patients had impaired LV function and five (5.1%) had LGE. Patients with impaired LV function had more end-systolic noncompacted mass (61.9 g±22.4 vs. 38.1 g±15.8, p < 0.001) and larger end-systolic noncompacted to total myocardial mass (44%±9 vs. 36%±12, p = 0.003). At 78 months follow-up [interquartile range(IQR) 66-90], MACCE occurred in 11(11.3%) patients; nine(81.8%) had impaired LV function and two(18.2%) had LGE. Impaired LV function and LV LGE were predictors of MACCE (HR = 35.6, 95% CI = 7.65-165.21, p < 0.001 and HR = 16.2, 95% CI = 4.54-57.84, p < 0.001) whereas noncompacted mass were not. CONCLUSION: Noncompacted mass was not an independent predictor of major adverse events but in patients with impaired LV function and/or LV LGE, the risk of MACCE was high. These results highlight the importance of including LV volumetrics and scar in the assessment of patients with LV noncompaction.

Inkjet formation of unilamellar lipid vesicles for cell-like encapsulation.

Encapsulation of macromolecules within lipid vesicles has the potential to drive biological discovery and enable development of novel, cell-like therapeutics and sensors. However, rapid and reliable production of large numbers of unilamellar vesicles loaded with unrestricted and precisely-controlled contents requires new technologies that overcome size, uniformity, and throughput limitations of existing approaches. Here we present a high-throughput microfluidic method for vesicle formation and encapsulation using an inkjet printer at rates up to 200 Hz. We show how multiple high-frequency pulses of the inkjet's piezoelectric actuator create a microfluidic jet that deforms a bilayer lipid membrane, controlling formation of individual vesicles. Variations in pulse number, pulse voltage, and solution viscosity are used to control the vesicle size. As a first step toward cell-like reconstitution using this method, we encapsulate the cytoskeletal protein actin and use co-encapsulated microspheres to track its polymerization into a densely entangled cytoskeletal network upon vesicle formation.

Bacterial variability in the mammalian gut captured by a single-cell synthetic oscillator.

Synthetic gene oscillators have the potential to control timed functions and periodic gene expression in engineered cells. Such oscillators have been refined in bacteria in vitro, however, these systems have lacked the robustness and precision necessary for applications in complex in vivo environments, such as the mammalian gut. Here, we demonstrate the implementation of a synthetic oscillator capable of keeping robust time in the mouse gut over periods of days. The oscillations provide a marker of bacterial growth at a single-cell level enabling quantification of bacterial dynamics in response to inflammation and underlying variations in the gut microbiota. Our work directly detects increased bacterial growth heterogeneity during disease and differences between spatial niches in the gut, demonstrating the deployment of a precise engineered genetic oscillator in real-life settings.

Development of MAST: A Microscopy-Based Antimicrobial Susceptibility Testing Platform.

Antibiotic resistance is compromising our ability to treat bacterial infections. Clinical microbiology laboratories guide appropriate treatment through antimicrobial susceptibility testing (AST) of patient bacterial isolates. However, increasingly, pathogens are developing resistance to a broad range of antimicrobials, requiring AST of alternative agents for which no commercially available testing methods are available. Therefore, there exists a significant AST testing gap in which current methodologies cannot adequately address the need for rapid results in the face of unpredictable susceptibility profiles. To address this gap, we developed a multicomponent, microscopy-based AST (MAST) platform capable of AST determinations after only a 2 h incubation. MAST consists of a solid-phase microwell growth surface in a 384-well plate format, inkjet printing-based application of both antimicrobials and bacteria at any desired concentrations, automated microscopic imaging of bacterial replication, and a deep learning approach for automated image classification and determination of antimicrobial minimal inhibitory concentrations (MICs). In evaluating a susceptible strain set, 95.8% were within ±1 and 99.4% were within ±2, twofold dilutions, respectively, of reference broth microdilution MIC values. Most (98.3%) of the results were in categorical agreement. We conclude that MAST offers promise for rapid, accurate, and flexible AST to help address the antimicrobial testing gap.

Predictors of treatment choices and associated outcomes in actinic keratoses: results from a national physician survey study.

OBJECTIVES: Actinic keratoses (AKs) are common skin lesions with the potential to progress to squamous cell carcinoma. Many effective treatment alternatives exist, yet the reasons for treatment choice have not been explored. This study examined which AK therapy was preferred among dermatologists and primary care physicians (PCPs), as well as potential determinants of therapeutic selection. METHODS: A random national sample of 534 dermatologists and PCPs selected from the American Medical Association database completed AK questionnaires. The final sample included 1184 AK patients treated by dermatologists and 559 AK patients treated and/or referred by PCPs. All analyses were weighted using the survey sampling weights. RESULTS: Patients who had new and recurring lesions as well as patients who had a mean duration of more than a year since the last AK episode treatment (all p<0.05) were more likely to receive pharmacotherapy. Patients being treated by a dermatologist, receiving pharmacotherapy treatment only, and having both new and recurring lesions (all p<0.05) were less likely to have a complete treatment success. CONCLUSIONS: This study identifies several patient and physician factors associated with treatment preference and related outcomes in patients being treated for AK.

Long-term follow-up of patients with obstructive hypertrophic cardiomyopathy treated with dual-chamber pacing.

In this study, patients with obstructive hypertrophic cardiomyopathy (HC) were treated with dual-chamber pacemaker therapy. Long-term follow-up analysis showed that dual-chamber pacemaker therapy in selected patients resulted in a significant reduction in symptoms and in the left ventricular outflow tract gradient, which was maintained up to 10 years after implantation. Dual-chamber pacing is of potential long-term benefit in selected groups of patients with obstructive HC.