Rapid profiling of transcription factor-cofactor interaction networks reveals principles of epigenetic regulation

Transcription factor (TF)-cofactor (COF) interactions define dynamic, cell-specific networks that govern gene expression; however, these networks are understudied due to a lack of methods for high-throughput profiling of DNA-bound TF-COF complexes. Here we describe the Cofactor Recruitment (CoRec) method for rapid profiling of cell-specific TF-COF complexes. We define a lysine acetyltransferase (KAT)-TF network in resting and stimulated T cells. We find promiscuous recruitment of KATs for many TFs and that 35% of KAT-TF interactions are condition specific. KAT-TF interactions identify NF-κB as a primary regulator of acutely induced H3K27ac. Finally, we find that heterotypic clustering of CBP/P300-recruiting TFs is a strong predictor of total promoter H3K27ac. Our data supports clustering of TF sites that broadly recruit KATs as a mechanism for widespread co-occurring histone acetylation marks. CoRec can be readily applied to different cell systems and provides a powerful approach to define TF-COF networks impacting chromatin state and gene regulation.

Management of acute cervical spinal cord injury in the non-specialist intensive care unit: a narrative review of current evidence

Each year approximately one million people suffer spinal cord injury, which has significant physical, psychosocial and economic impacts on patients and their families. Spinal cord rehabilitation centres are a well-established part of the care pathway for patients with spinal cord injury and facilitate improvements in functional independence and reductions in healthcare costs. Within the UK, however, there are a limited number of spinal cord injury centres, which delays admission. Patients and their families often perceive that they are not receiving specialist care while being treated in non-specialist units. This review aimed to provide clinicians who work in non-specialist spinal injury centres with a summary of contemporary studies relevant to the critical care management of patients with cervical spinal cord injury. We undertook a targeted literature review including guidelines, systematic reviews, meta-analyses, clinical trials and randomised controlled trials published in English between 1 June 2017 and 1 June 2023. Studies involving key clinical management strategies published before this time, but which have not been updated or repeated, were also included. We then summarised the key management themes: acute critical care management approaches (including ventilation strategies, blood pressure management and tracheostomy insertion); respiratory weaning techniques; management of pain and autonomic dysreflexia; and rehabilitation.

A Comparative Investigation of Equine-Related and Bovine-Related Human Fatalities in Oklahoma

ABSTRACT

This study examined 71 cases, where 45 cases were equine-related and 26 were bovine-related. Data for this study were collected by examining cases between 2000 and 2022 from the Oklahoma Office of the Chief Medical Examiner database.A majority of the equine-related fatality cases involved males aged 0 to 18 and 60 to 69 years, with sustained injuries of the head, neck, and thoracic regions while being mounted. These injuries were most often inflicted by being kicked or resulted from blunt force of impact. A majority of the bovine-related fatality cases involved males aged 60 to 79 years, with sustained injuries of the head, neck, and thoracic regions while being unmounted. These injuries were most often inflicted by being butted, trampled, or resulted from blunt force of impact. Of the total cases, approximately 42% of the causes of death were blunt force trauma of the head/neck and nearly 34% were multiple blunt force injuries. Only 3 mechanisms of death were discussed.There are distinct similarities in the most prominent gender, cause of sustained injury, and location of injury between equine- and bovine-related fatalities in Oklahoma. This study lends significant support to the need for increased awareness of safe handling practices and safety precaution education for both equine and bovine activities.

Perspectives of Healthcare Professionals on the Management and Treatment of Advanced Ovarian Cancer in the UK: Results From the KNOW-OC Survey

AIMS

New treatment options for advanced ovarian cancer have the potential to significantly change the treatment pathway in the UK. Understanding the structures and responsibilities of multidisciplinary teams/tumour boards (MDT) and regional variations will enable services to adapt more effectively to these changes.

MATERIALS AND METHODS

The KNOW-OC survey was conducted in 2020 to understand the views of a selected group of 66 healthcare professionals (HCPs) involved in advanced ovarian cancer care in UK hospitals.

RESULTS

The results showed that MDT involvement in the management of advanced ovarian cancer varied depending on pathway stage and line of relapse, with 98.5% of HCPs responding that the MDT was involved in decisions at initial presentation, but only 40.9% for patients with multiple relapses. The MDT was mostly responsible for determining whether the patients would undergo primary or interval cytoreductive surgery according to 75.8% of respondents, and most HCPs (80.3%) stated that tumour dissemination patterns were the most important factor influencing this decision. The most commonly assessed biomarkers at the time of the survey were CA125, gBRCA and tBRCA. Homologous recombination deficiency was viewed as the second most important factor for determining prognosis, but few centres had access to testing at the time of survey completion. The use of active surveillance was expected to decrease in favour of first-line targeted therapies. Nearly all (98.5%) HCPs agreed there is a role for secondary cytoreductive surgery for the treatment of recurrence (for carefully selected patients).

CONCLUSIONS

The results highlighted UK-specific geographical variation in the views of HCPs on MDT involvement and specific practices, such as molecular biomarker testing, and the overall treatment approach. Together, these findings improve the understanding of reported clinical practice across the UK for ovarian cancer and provide insight into decision-making associated with updates to recommendations for best practice (e.g. European Society for Medical Oncology/European Society of Gynaecological Oncology consensus statements) and the introduction of new treatment options.

Structural changes in layers of lipid mixtures at low surface tensions

Layers of pulmonary lipids on an aqueous substrate at non-equilibrium conditions can decrease the surface tension of water to quite low values. This is connected with different relaxation processes occurring at the interface and the associated changes in the surface layer structure. Results of measurements by the combination of methods like surface rheology, ellipsometry, Brewster angle microscopy, and IRRAS for spread layers of lipid mixtures open a possibility to specify the dynamics of structural changes at conditions close to the physiological state. At sufficiently low surface tension values (below 5 mN/m) significant changes in the ellipsometric signal were observed for pure DPPC layers, which can be related to a transition from 2D to 3D structures caused by the layer folding. The addition of other lipids can accelerate the relaxation processes connected with squeezing-out of molecules or multilayer stacks formation hampering thereby a decrease of surface tension down to low values corresponding to the folding of the monolayer.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Correction of symbrachydactyly: a systematic review of surgical options

Symbrachydactyly is a rare congenital malformation of the hand characterized by short or even absent fingers with or without syndactyly, mostly unilaterally present. The hand condition can vary from a small hand to only nubbins on the distal forearm. This study aims to systematically review the surgical management options for symbrachydactyly and compare functional and aesthetic outcomes.The review was performed according to the PRISMA guidelines. Literature was systematically assessed searching the Cochrane Library, PubMed, Embase, and PROSPERO databases up to January 1, 2023. Studies were identified using synonyms for 'symbrachydactyly' and 'treatment'. Inclusion criteria were the report of outcomes after surgical treatment of symbrachydactyly in humans. Studies were excluded if they were written in another language than English, German, or French. Case reports, letters to the editor, studies on animals, cadaveric, in vitro studies, biomechanical reports, surgical technique description, and papers discussing traumatic or oncologic cases were excluded.Twenty-four studies published were included with 539 patients (1037 digit corrections). Only one study included and compared two surgical techniques. The quality of the included studies was assessed using the Modified Coleman Methodology Score and ranged from 25 to 47. The range of motion was the main reported outcome and demonstrated modest results in all surgical techniques. The report on aesthetics of the hand was limited in non-vascularized transfers to 2/8 studies and in vascularized transfers to 5/8 studies, both reporting satisfactory results. On average, there was a foot donor site complication rate of 22% in non-vascularized transfers, compared to 2% in vascularized transfers. The hand-related complication rate of 54% was much higher in the vascularized group than in the non-vascularized transfer with 16%.No uniform strategy to surgically improve symbrachydactyly exists. All discussed techniques show limited functional improvement with considerable complication rates, with the vascularized transfer showing relative high hand-related complications and the non-vascularized transfer showing relative high foot-related complications.There were no high-quality studies, and due to a lack of comparing studies, the data could only be analysed qualitatively. Systematic assessment of studies showed insufficient evidence to determine superiority of any procedure to treat symbrachydactyly due to inadequate study designs and comparative studies. This systematic review was registered at the National Institute for Health Research PROSPERO International Prospective Register of Systematic Reviews number: CRD42020153590 and received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.Level of evidenceI.Systematic review registrationPROSPERO CRD42020153590.

The International Consortium on Primary Graft Dysfunction: Redefining Clinical Risk Factors in the Contemporary Era of Heart Transplantation

BACKGROUND

Primary Graft Dysfunction (PGD) is the leading cause of morbidity and mortality early after heart transplant (HT). The International Consortium on PGD is a multicenter collaboration dedicated to identifying the clinical risk factors for PGD in the contemporary era of HT. The objectives of the current report were to 1) assess the incidence of severe PGD in an international cohort, 2) evaluate the performance of the most validated PGD risk tool, the RADIAL score, in a contemporary cohort, and 3) redefine clinical risk factors for severe PGD in the current era of HT.

METHODS

This is a retrospective, observational study of consecutive adult HT recipients between 2010 and 2020 in 10 centers in the United States, Canada, and Europe. Patients with severe PGD were compared to those without severe PGD (comprising those with no, mild and moderate PGD). The RADIAL score was calculated for each transplant recipient. The discriminatory power of the RADIAL score was evaluated using receiver operating characteristic (ROC) analysis and its calibration was assessed by plotting the percentage of PGD predicted versus observed. To identify clinical risk factors associated with severe PGD, we performed multivariable mixed-effects logistic regression modeling to account for among-center variability.

RESULTS

A total of 2,746 patients have been enrolled in the registry to date, including 2,015 (73.4%) from North America, and 731 (26.6%) from Europe. 215 participants (7.8%) met the criteria for severe PGD. There was an increase in the incidence of severe PGD over the study period (p-value for trend by difference sign test = 0.004). The Kaplan Meier estimate for 1-year survival was 75.7% [95%CI 69.4-80.9%] in patients with severe PGD as compared to 94.4% [95% CI 93.5-95.2%] in those without severe PGD (log-rank p-value <0.001). The RADIAL score performed poorly in our contemporary cohort and was not associated with severe PGD with an AUC of 0.53 (95%CI 0.48-0.58). In the multivariable regression model, acute preoperative dialysis (OR 2.41, 95% CI 1.31 - 4.43), durable LVAD support (OR 1.77, 95% CI 1.13 - 2.77), and total ischemic time (OR 1.20 for each additional hour, 95% CI 1.02 - 1.41) were associated with an increased risk of severe PGD.

CONCLUSIONS

Our consortium has identified an increasing incidence of PGD in the modern transplant era. We identified contemporary risk factors for this early post-transplant complication, which confers a high mortality risk. These results may enable the identification of patients at high risk for developing severe PGD in order to inform peri-transplant donor and recipient management practices.

Surfactant Adsorption Layers: Experiments and Modeling

During recent years, great progress has been made in understanding the adsorption of surfactants at liquid interfaces. In addition to tensiometry, new efficient methodologies have been developed, in particular interfacial selective optical methods which allow direct access to the adsorbed amounts and interfacial layer compositions. In addition to these new experimental tools, the thermodynamic description by equations of state now allows one to provide a quantitative picture of surfactant interfacial layers. This is most notable for surfactant layers at water/oil interfaces. Additional knowledge about the structure of interfacial layers was gained through different types of molecular modeling. Improved interrelationships between these three aspects are the challenges for current and future work. Particular attention must be paid to dilational interfacial rheology studies, as these mechanical quantities are much more sensitive to small changes in the interfacial composition and structure.

Application Experiences on a GPU-Accelerated Arm-based HPC Testbed

This paper assesses and reports the experience of ten teams working to port, validate, and benchmark several High Performance Computing applications on a novel GPU-accelerated Arm testbed system. The testbed consists of eight NVIDIA Arm HPC Developer Kit systems, each one equipped with a server-class Arm CPU from Ampere Computing and two data center GPUs from NVIDIA Corp. The systems are connected together using InfiniBand interconnect. The selected applications and mini-apps are written using several programming languages and use multiple accelerator-based programming models for GPUs such as CUDA, OpenACC, and OpenMP offloading. Working on application porting requires a robust and easy-to-access programming environment, including a variety of compilers and optimized scientific libraries. The goal of this work is to evaluate platform readiness and assess the effort required from developers to deploy well-established scientific workloads on current and future generation Arm-based GPU-accelerated HPC systems. The reported case studies demonstrate that the current level of maturity and diversity of software and tools is already adequate for large-scale production deployments.

A method for estimating and characterizing explicitly nonlinear dynamic functional network connectivity in resting-state fMRI data

The past 10 years have seen an explosion of approaches that focus on the study of time-resolved change in functional connectivity (FC). FC characterization among networks at a whole-brain level is frequently termed functional network connectivity (FNC). Time-resolved or dynamic functional network connectivity (dFNC) focuses on the estimation of transient, recurring, whole-brain patterns of FNC. While most approaches in this area have attempted to capture dynamic linear correlation, we are particularly interested in whether explicitly nonlinear relationships, above and beyond linear, are present and contain unique information. This study thus proposes an approach to assess explicitly nonlinear dynamic functional network connectivity (EN dFNC) derived from the relationship among independent component analysis time courses. Linear relationships were removed at each time point to evaluate, typically ignored, explicitly nonlinear dFNC using normalized mutual information (NMI). Simulations showed the proposed method estimated explicitly nonlinearity over time, even within relatively short windows of data. We then, applied our approach on 151 schizophrenia patients, and 163 healthy controls fMRI data and found three unique, highly structured, mostly long-range, functional states that also showed significant group differences. In particular, explicitly nonlinear relationships tend to be more widespread than linear ones. Results also highlighted a state with long range connections to the visual domain, which were significantly reduced in schizophrenia. Overall, this work suggests that quantifying EN dFNC may provide a complementary and potentially valuable tool for studying brain function by exposing relevant variation that is typically ignored.

Predictors of early renal dysfunction after heart transplantation: a report from the International Consortium on Primary Graft Dysfunction

Background

Renal dysfunction is a common complication after heart transplantation (HT). Renal replacement therapy (RRT) after HT has been associated with increased risk of death. Long-term renal dysfunction is associated mainly to immunosuppressive therapy but is also strongly related to post-transplant renal failure. Predictors of early renal dysfunction after HT have not been clearly identified.

Purpose

We aimed to define predictors of early renal dysfunction after HT.

Methods

Our consortium includes 10 centers in the US, Canada and Europe. We collected data on all consecutive single-organ HT recipients from 2010 to 2020. The primary outcome was early renal dysfunction (ERD), defined as a composite of need for RRT or creatinine ≥2.5 mg/dL 24 hours after HT. We assessed the incidence of early renal dysfunction and performed univariate and multivariate analyses to identify the recipient and transplant characteristics associated with its development.

Results

We included 2,764 HT recipients: 282 (10.2%) presented early renal dysfunction and 2482 (89.8%) did not. Recipients who presented postoperative renal dysfunction were more frequently male, Caucasian, with previous sternotomy, higher baseline creatinine, longer ischemic time and worse donor LVEF. They were also more likely to be under RRT, intravenous inotropes or ECMO support and there was more incidence of severe primary graft dysfunction (PGD) (Table 1). Multi-variable logistic regression demonstrated that the strongest predictors for post-transplant renal dysfunction were development of severe PGD (OR 5.26, 2.88–9.62, p&lt;0,001) and RRT prior to HT (OR 5.80, 2.93–11.5, p&lt;0.001). Other predictors were male sex, previous sternotomy, long ischemic time and need for inotropes prior to HT.

Conclusions

Early renal dysfunction is a common complication after HT with an incidence around 10% in a large and contemporary cohort. The presence of PGD and need for RRT pre-transplant were the strongest predictors for its development. Interestingly, emergent transplantation or need for MCS were not independently associated with ERD. Further studies are needed to identify patients at high risk of early and late kidney dysfunction that may benefit from combined transplantation.

Funding Acknowledgement

Type of funding sources: None.

Measurement properties of the WHO Disability Assessment Schedule 2.0 for evaluating functional status after inpatient surgery

BACKGROUND

Expert recommendations propose the WHO Disability Assessment Schedule (WHODAS) 2.0 as a core outcome measure in surgical studies, yet data on its long-term measurement properties remain limited. These were evaluated in a secondary analysis of the Measurement of Exercise Tolerance before Surgery (METS) prospective cohort.

METHODS

Participants were adults (40 years of age or older) who underwent inpatient non-cardiac surgery. The 12-item WHODAS and EQ-5DTM-3L questionnaires were administered preoperatively (in person) and 1 year postoperatively (by telephone). Responsiveness was characterized using standardized response means (SRMs) and correlation coefficients between change scores. Construct validity was evaluated using correlation coefficients between 1-year scores and comparisons of WHODAS scores across clinically relevant subgroups.

RESULTS

The analysis included 546 patients. There was moderate correlation between changes in WHODAS and various EQ-5DTM subscales. The strongest correlation was between changes in WHODAS and changes in the functional domains of the EQ-5D-3L-for example, mobility (Spearman's rho 0.40, 95 per cent confidence interval [c.i.] 0.32 to 0.48) and usual activities (rho 0.45, 95 per cent c.i. 0.30 to 0.52). When compared across quartiles of EQ-5D index change, median WHODAS scores followed expected patterns of change. In subgroups with expected functional status changes, the WHODAS SRMs ranged from 'small' to 'large' in the expected directions of change. At 1 year, the WHODAS demonstrated convergence with the EQ-5D-3L functional domains, and good discrimination between patients with expected differences in functional status.

CONCLUSION

The WHODAS questionnaire has construct validity and responsiveness as a measure of functional status at 1 year after major surgery.

P-281 A multi-centre evaluation of a novel 4-cell embryo classification system based on intercellular contact points

Study question

Is there any prognostic value to classifying 4-cell embryos according to intercellular contact points (ICPs)?

Summary answer

A significant association was found between the new blastomere arrangement classifications and blastulation, as well as blastocyst quality. No significant association was found for pregnancy.

What is known already

Current literature states that the geometric arrangement of blastomeres in 4-cell embryos is usually classified as either “tetrahedral” or “non-tetrahedral/planar”. Though tetrahedral embryos have been associated with greater developmental capacity, their prevalence has varied between studies. At ESHRE 2021, Hickman et al. proposed a more fine-grained classification system; each class was associated with a 4-digit code, where the Nth digit in said code gave the number of cells with N-1 ICPs. This gave rise to 6 classes: tetrahedral (0004), pseudotetrahedral (0022), planar (0040), closed-Y (0121), open-Y (0301) and linear (0220). In our study, we evaluate this new system.

Study design, size, duration

This study was a retrospective analysis of 844 4-cell embryos across 3 clinics in 3 countries. Focal stacks of the embryos were captured on Embryoscope/MIRI time-lapse incubators between 2018 and 2020. Embryos were annotated by their respective clinics using the original “tetrahedral/planar” system. Additionally, data on blastulation, blastocyst grade (Gardner scale) and biochemical pregnancy rates were obtained for each embryo.

Participants/materials, setting, methods

The embryos were annotated according to the new system by a panel of three researchers without knowledge of the clinics’ or each other’s classifications. Afterwards, the panelists assembled for discussion and a unanimous consensus was reached for each embryo. The cell arrangement classes were analysed with respect to blastulation rates, blastocyst grade and pregnancy rates using chi-squared tests. The distribution of classes across the clinics was also analysed, as well as agreement among the panelists.

Main results and the role of chance

Under the new system, tetrahedral and pseudotetrahedral embryos saw significantly higher rates of blastulation (P = 0.017) and good-quality blastocysts (p = 0.043; here, “good-quality” means that the grade contains no ‘C’s or numbers less than 3) compared to other arrangements. No association was found with respect to biochemical pregnancy (p = 0.77).

There was significant variation between the clinic-provided classifications (p &lt; 0.001) with tetrahedral-to-planar ratios ranging from 1 to 9. Under the new system, there was no significant difference between the proportions of each arrangement (p = 0.66). The arrangements in order of decreasing prevalence across all the data were tetrahedral (63.7%), pseudotetrahedral (25.8%), planar (8.0%), closed-Y (2.2%) and linear (0.3%). No open-Y embryos were observed. Upon comparison with the clinic-provided tetrahedral/planar classifications, there were clear differences in the treatment of pseudotetrahedral embryos - some clinics predominantly classified them as “tetrahedral” while others as “planar”.

Prior to any discussions, the panelists’ annotations unanimously agreed on the classifications of 63% of the embryos; with 33% of the embryos having 2 different classifications and 4% of embryos causing total disagreement. The majority of disagreements regarded pseudotetrahedral embryos being confused for either tetrahedral or planar embryos.

Limitations, reasons for caution

It can be at times difficult to visualise the 3D structure of embryos from focal stacks. As a result, some annotations may be erroneous, though the use of a panel-based approach helped to mitigate this. Moreover, further studies will need to take place to validate the findings in this work.

Wider implications of the findings

The findings demonstrate the prognostic utility of Hickman et al.’s ICP-based classification system. Moreover, the findings suggest that much of the variability seen in the prevalence of tetrahedral embryos under the tetrahedral/planar system came from the mislabelling of pseudotetrahedral embryos which comprised 25.8% of the study population.

Trial registration number

N/A

Medication-Related Fall (MRF) screening and scoring tool: consensus Delphi validation

Introduction

Falls are associated with negative health outcomes such as injury and mortality, as well as increased healthcare usage and costs. Risk factors for falls are multifactorial and include polypharmacy and the use of certain medications (1).

Aim

To develop and validate a medication-related fall (MRF) screening and scoring tool.

Methods

The MRF tool was developed from medication classes associated with falling in the Polypharmacy Guidance Realistic Prescribing 2018 (2), and additional medications identified and categorised by specialist and consultant pharmacists and physicians across a region of the United Kingdom. Medication classes were categorised as high-risk (three points), moderate-risk (two points) or low-risk (one point) in their ‘potential to cause falls’. The overall medication-related fall risk for the patient was determined by summing the scores for all medications. The MRF was validated using Delphi consensus methodology, whereby three iterative rounds of online surveys were conducted using SurveyMonkey®. Delphi panel experts were defined as individuals with recognised expertise in geriatric medicine and pharmacotherapy in older people. Twenty-two experts determined their agreement with the falls risk associated with each medication on a 5-point Likert scale with accompanying written feedback. Only medications with at least 75% of respondents agreeing or strongly agreeing were retained in the next round. Following the first validation round, any proposed criteria that did not meet retention requirements were removed. The second and third rounds of the survey were created based on the panel comments from the previous round.

Results

Consensus was reached for 19 medications/medication classes to be included in the final version of the MRF tool (table) and to reject eight medications/medication classes. Consensus was not reached regarding eight medications and they were not included in the final version of the tool.

Conclusion

The MRF tool is simple and feasible to use in healthcare settings to evaluate and optimise medications as a standalone screening instrument or as part of a multidisciplinary intervention to reduce fall risk and negative fall-related outcomes. The score from the MRF tool has potential for use as a clinical parameter to evaluate prescribing appropriateness.

References

(1) Public Health England (2020) Falls: applying All Our Health. Available at https://www.gov.uk/government/publications/falls-applying-all-our-health/falls-applying-all-our-health Guidance Falls: applying All Our Health. (Accessed: 4th April 2020)

(2) Scottish Government Polypharmacy Model of Care Group (2018). Polypharmacy Guidance, Realistic Prescribing. 3rd Edition.

Temporal shift and accuracy of machine learning in heart transplant outcomes

Background

Accurate prediction of outcomes following a heart transplant is critical to explaining risks and benefits to patients and decision-making when considering potential organ offers. Given the large number of potential variables to be considered, this task may be most efficiently performed using machine learning (ML).

Purpose

We trained and tested different ML algorithms to accurately predict outcomes following a cardiac transplant using the United Network of Organ Sharing (UNOS) database.

Methods

We included 67 939 adult and pediatric patients enrolled in the UNOS database between January 1994 and December 2016 who underwent cardiac transplantation (median age 53 [IQR 38 – 60], 72.7% males). In our models, as an input, we included 114 features that have been collected from recipients and donors prior to transplant. The primary outcome was all-cause mortality at one-year post-transplant. We evaluated three different ML methods: XGBoost, Random Forest (RF) and L2 regularized logistic regression. Algorithms were trained and tested using shuffled 10-fold cross-validation (CV) as well as rolling CV. In the rolling CV, to mimic prospective procedure, ML models were trained by incrementally adding patients according to transplant year and testing models on the data in the following year. The hyperparameters, controlling the learning process, were tuned using Bayesian optimization. Prognostic accuracy for one-year all-cause mortality was characterized using the area under the receiver-operating characteristic curve (AUC).

Results

In total, 8,394 patients died within 1 year of transplant. We observed a substantial difference in prognostic accuracy between the shuffled 10-fold CV and the rolling CV. In the 10-fold CV, XGBoost and RF achieved high predictive performance with AUC of 0.848 (95% CI: 0.842–0.854) and 0.891 (95% CI: 0.886–0.896), respectively. In the rolling CV, which is a more realistic setting, AUC dropped to 0.673 (95% CI: 0.661–0.684) for XGBoost and 0.670 (0.657–0.683) for RF. Predictive performance of L2 regularized logistic regression remained stable across the two CV procedures, achieving AUC 0.669 (95% CI: 0.662–0.676) in the 10-fold shuffled CV and 0.665 (95% CI: 0.649–0.680) in the rolling CV procedure (Figure).

Conclusions

Our study suggests that ML models could be used to predict mortality in the first year post-transplant. We also show that the choice of CV procedure is crucial for evaluating ML models, particularly in data collected over a long period of time. The difference between the shuffled and rolling CV in the predictive performance of the tree-based ML models might indicate temporal dataset shift. In the rolling CV, all three methods achieved similar predictive performance.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research Foundation Flanders (FWO)

Vanishing congenital lung malformations: What is the incidence of true regression?

BACKGROUND

A congenital lung malformation (CLM) that is diagnosed on prenatal ultrasound exam may subsequently become undetectable on later scans, a "vanishing" CLM.

OBJECTIVE

The purpose of our study is to characterize the prenatal natural history and postnatal outcomes of "vanishing" lesions treated at our institution.

METHODS

We performed a retrospective chart review of 107 patients diagnosed prenatally with CLM at our institution. Comparisons were made using Kruskal-Wallis or t-test for continuous variables and Fisher's exact test or Chi-Square test for categorical variables. Multivariable analysis using logistic regression was performed.

RESULTS

Of the 104 patients, 59 (56.7%) had lesions that became sonographically undetectable on serial ultrasound scans. Patients with lesions that vanished prenatally tended to need less Neonatal Intensive Care Unit (NICU) admission at birth (persistent CLM: 54.8%vs vanished CLM: 28.8%), decreased need for supplemental O2 at birth (persistent CLM: 31.0%vs vanished CLM: 11.9%), and decreased delay in feeds (persistent CLM: 26.2%vs vanished CLM: 8.5%) compared to those with persistent CLM. After multivariate analysis controlling for maternal steroid administration and sex, admission to NICU maintained a slight statistical significance, with patients in the vanishing CLM group 2.5 times less likely to be admitted to the NICU. None of our patients whose lesions vanished prenatally required mechanical ventilation. Eighty-six patients underwent postnatal computed tomography (CT) chest. Only 2 patients had lesions that regressed on postnatal CT.

CONCLUSION

Lesions that vanish on prenatal imaging may be associated with improved clinical outcomes. The rate of true regression at our institution was as low as 2.3%.

The LeVe CPAP System for Oxygen-Efficient CPAP Respiratory Support: Development and Pilot Evaluation

Background: The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has placed a significant demand on healthcare providers (HCPs) to provide respiratory support for patients with moderate to severe symptoms. Continuous Positive Airway Pressure (CPAP) non-invasive ventilation can help patients with moderate symptoms to avoid the need for invasive ventilation in intensive care. However, existing CPAP systems can be complex (and thus expensive) or require high levels of oxygen, limiting their use in resource-stretched environments. Technical Development + Testing: The LeVe ("Light") CPAP system was developed using principles of frugal innovation to produce a solution of low complexity and high resource efficiency. The LeVe system exploits the air flow dynamics of electric fan blowers which are inherently suited to delivery of positive pressure at appropriate flow rates for CPAP. Laboratory evaluation demonstrated that performance of the LeVe system was equivalent to other commercially available systems used to deliver CPAP, achieving a 10 cm H2O target pressure within 2.4% RMS error and 50-70% FiO2 dependent with 10 L/min oxygen from a commercial concentrator. Pilot Evaluation: The LeVe CPAP system was tested to evaluate safety and acceptability in a group of ten healthy volunteers at Mengo Hospital in Kampala, Uganda. The study demonstrated that the system can be used safely without inducing hypoxia or hypercapnia and that its use was well-tolerated by users, with no adverse events reported. Conclusions: To provide respiratory support for the high patient numbers associated with the COVID-19 pandemic, healthcare providers require resource efficient solutions. We have shown that this can be achieved through frugal engineering of a CPAP ventilation system, in a system which is safe for use and well-tolerated in healthy volunteers. This approach may also benefit other respiratory conditions which often go unaddressed in Low and Middle Income Countries (LMICs) for want of context-appropriate technology designed for the limited oxygen resources available.

P–165 Using Artificial Intelligence to Classify Embryo Shape: An International Perspective

Study question

Is a pre-trained machine learning algorithm able to accurately detect cellular arrangement in 4-cell embryos from a different continent?

Summary answer

Artificial Intelligence (AI) analysis of 4-cell embryo classification is transferable across clinics globally with 79% accuracy.

What is known already

Previous studies observing four-cell human embryo configurations have demonstrated that non-tetrahedral embryos (embryos in which cells make contact with fewer than 3 other cells) are associated with compromised blastulation and implantation potential. Previous research by this study group has indicated the efficacy of AI models in classification of tetrahedral and non-tetrahedral embryos with 87% accuracy, with a database comprising 2 clinics both from the same country (Brazil). This study aims to evaluate the transferability and robustness of this model on blind test data from a different country (France).

Study design, size, duration

The study was a retrospective cohort analysis in which 909 4-cell embryo images (“tetrahedral”, n = 749; “non-tetrahedral”, n = 160) were collected from 3 clinics (2 Brazilian, 1 French). All embryos were captured at the central focal plane using Embryoscope™ time-lapse incubators. The training data consisted solely of embryo images captured in Brazil (586 tetrahedral; 87 non-tetrahedral) and the test data consisted exclusively of embryo images captured in France (163 tetrahedral; 72 non-tetrahedral).

Participants/materials, setting, methods

The embryo images were labelled as either “tetrahedral” or “non-tetrahedral” at their respective clinics. Annotations were then validated by three operators. A ResNet–50 neural network model pretrained on ImageNet was fine-tuned on the training dataset to predict the correct annotation for each image. We used the cross entropy loss function and the RMSprop optimiser (lr = 1e–5). Simple data augmentations (flips and rotations) were used during the training process to help counteract class imbalances.

Main results and the role of chance

Our model was capable of classifying embryos in the blind French test set with 79% accuracy when trained with the Brazilian data. The model had sensitivity of 91% and 51% for tetrahedral and non-tetrahedral embryos respectively; precision was 81% and 73%; F1 score was 86% and 60%; and AUC was 0.61 and 0.64. This represents a 10% decrease in accuracy compared to when the model both trained and tested on different data from the same clinics.

Limitations, reasons for caution

Although strict inclusion and exclusion criteria were used, inter-operator variability may affect the pre-processing stage of the algorithm. Moreover, as only one focal plane was used, ambiguous cases were interpoloated and further annotated. Analysing embryos at multiple focal planes may prove crucial in improving the accuracy of the model.

Wider implications of the findings: Though the use of machine learning models in the analysis of embryo imagery has grown in recent years, there has been concern over their robustness and transferability. While previous results have demonstrated the utility of locally-trained models, our results highlight the potential for models to be implemented across different clinics.

Trial registration number

Not applicable

CT findings, management and short-term outcome of dogs with pyothorax: 101 cases (2010 to 2019)

OBJECTIVES

To describe diagnosis, CT findings, management and short-term outcome of a large population of canine pyothorax cases.

METHODS

Retrospective analysis of 101 canine pyothorax cases at two UK referral centres. Medical records and CT images were reviewed. Dogs were included if pre- and post-contrast CT was performed within 48 hours of presentation.

RESULTS

CT abnormalities included pleural thickening (84.1%), pannus (67.3%), pneumothorax (61.4%), mediastinal effusion (28.7%), pulmonary (13.8%) and mediastinal (7.9%) abscessation, foreign body presence (7.9%), foreign body tracts (6.9%) and pneumonia (6.9%). Seventy-one percent of dogs were managed surgically, of which 90.2% survived, and 29% were managed medically, of which 72.4% survived. Overall mortality was 14.8% and 86.6% of these dogs died within 48 hours of admission. All dogs with evidence of a foreign body on CT underwent surgery.

CLINICAL SIGNIFICANCE

Mortality in our population was low and most dogs that died did so within 48 hours of hospitalisation, regardless of management type.

Healthcare delivery for HIV-positive people with tuberculosis in Europe

BACKGROUND

In a 2013 survey, we reported distinct discrepancies in delivery of tuberculosis (TB) and HIV services in eastern Europe (EE) vs. western Europe (WE).

OBJECTIVES

To verify the differences in TB and HIV services in EE vs. WE.

METHODS

Twenty-three sites completed a survey in 2018 (EE, 14; WE, nine; 88% response rate). Results were compared across as well as within the two regions. When possible, results were compared with the 2013 survey.

RESULTS

Delivery of healthcare was significantly less integrated in EE: provision of TB and HIV services at one site (36% in EE vs. 89% in WE; P = 0.034), and continued TB follow-up in one location (42% vs. 100%; P = 0.007). Although access to TB diagnostics, standard TB and HIV drugs was generally good, fewer sites in EE reported unlimited access to rifabutin/multi-drug-resistant TB (MDR-TB) drugs, HIV integrase inhibitors and opioid substitution therapy (OST). Compared with 2013, routine usage of GeneXpert was more common in EE in 2018 (54% vs. 92%; P = 0.073), as was access to moxifloxacin (46% vs. 91%; P = 0.033), linezolid (31% vs. 64%; P = 0.217), and bedaquiline (0% vs. 25%; P = 0.217). Integration of TB and HIV services (46% vs. 39%; P = 1.000) and provision of OST to patients with opioid dependency (54% vs. 46%; P = 0.695) remained unchanged.

CONCLUSION

Delivery of TB and HIV healthcare, including integration of TB and HIV care and access to MDR-TB drugs, still differs between WE and EE, as well as between individual EE sites.

Posterior reversible encephalopathy syndrome in the emergency department: A single center retrospective study

INTRODUCTION

Posterior Reversible Encephalopathy Syndrome (PRES) and the related term Reversible Posterior Leukoencephalopathy Syndrome (RPLS) denote a constellation of clinical symptoms paired with key radiological findings. These symptoms may include headache, altered mental status, visual changes, and seizures. PRES is a rare condition and remains a challenging diagnosis to make in the emergency department. Data on risk factors and clinical presentation are limited, and there is no recent literature-supported diagnostic criteria. Our primary objective was to identify initial symptoms, clinical presentation, and risk factors that should guide the emergency clinician to consider a diagnosis of PRES. A secondary objective was to identify associations between risk factors and the outcomes of mortality and ICU admissions.

METHODS

This was a retrospective, observational study that evaluated patients seen in the Emergency Department (ED) in an urban tertiary care center with the diagnosis of PRES or RPLS from 1/1/2008 to 1/1/2018. The Health System's Electronic Medical Record was used to collect data. Search criteria included any patient diagnosed with Posterior Reversible Encephalopathy Syndrome (PRES) or Reversible Posterior Leukoencephalopathy Syndrome (RPLS), and excluded patients under 18 years of age, transfer patients, or patients that were not evaluated in our emergency department.

RESULTS

We identified 98 patients based on our initial search criteria. After a chart review, 27 patients met our predefined eligibility criteria. In patients with confirmed diagnosis of PRES, the majority were female (70%) and 37% were either on an immunomodulator or undergoing chemotherapy at the time of presentation. 67% of patients presented with altered mental status, 41% had a focal neurologic deficit, and 37% had a witnessed seizure prior to diagnosis. Headache (48%), nausea (33%), and vision changes (30%) were the next most common reported symptoms. The majority of patients were hypertensive at time of presentation (82%) and many had a past medical history of hypertension (78%); twelve were given anti-hypertensive medications. 33% of the patients were admitted to the ICU and 26% died. There were no statistical associations found between documented ED interventions and the outcome of mortality.

CONCLUSION

PRES is difficult to identify and diagnose in the emergency department. Significant risk factors such as female gender, hypertension, and those currently undergoing active immunotherapy/chemotherapy are associated with PRES. Common presenting complaints and exam findings include headache, altered mental status, and neurologic deficits. Emergency providers should consider PRES in patients presenting with altered mental status with significant risk factors, especially with neurologic deficits for which stroke has been ruled out.

New Caledonian crows plan for specific future tool use

The ability to plan for future events is one of the defining features of human intelligence. Whether non-human animals can plan for specific future situations remains contentious: despite a sustained research effort over the last two decades, there is still no consensus on this question. Here, we show that New Caledonian crows can use tools to plan for specific future events. Crows learned a temporal sequence where they were (a) shown a baited apparatus, (b) 5 min later given a choice of five objects and (c) 10 min later given access to the apparatus. At test, these crows were presented with one of two tool-apparatus combinations. For each combination, the crows chose the right tool for the right future task, while ignoring previously useful tools and a low-value food item. This study establishes that planning for specific future tool use can evolve via convergent evolution, given that corvids and humans shared a common ancestor over 300 million years ago, and offers a route to mapping the planning capacities of animals.

COVID-19: NAD+ deficiency may predispose the aged, obese and type2 diabetics to mortality through its effect on SIRT1 activity

The SARS-CoV-2 hyperinflammatory response is associated with high mortality. This hypothesis suggests that a deficiency of nicotinamide adenine dinucleotide (NAD+) may be the primary factor related to the SARS-Cov-2 disease spectrum and the risk for mortality, as subclinical nutritional deficiencies may be unmasked by any significant increase in oxidative stress. NAD+ levels decline with age and are also reduced in conditions associated with oxidative stress as occurs with hypertension, diabetes and obesity. These groups have also been observed to have high mortality following infection with COVID-19. Further consumption of NAD+ in a pre-existent depleted state is more likely to cause progression to the hyperinflammatory stage of the disease through its limiting effects on the production of SIRT1. This provides a unifying hypothesis as to why these groups are at high risk of mortality and suggests that nutritional support with NAD+ and SIRT1 activators, could minimise disease severity if administered prophylactically and or therapeutically. The significance of this, if proven, has far-reaching consequences in the management of COVID-19 especially in third world countries, where resources and finances are limited.