A universal fluorescence polarization high throughput screening assay to target the SAM-binding sites of SARS-CoV-2 and other viral methyltransferases

SARS-CoV-2 has caused a global pandemic with significant humanity and economic loss since 2020. Currently, only limited options are available to treat SARS-CoV-2 infections for vulnerable populations. In this study, we report a universal fluorescence polarization (FP)-based high throughput screening (HTS) assay for SAM-dependent viral methyltransferases (MTases), using a fluorescent SAM-analogue, FL-NAH. We performed the assay against a reference MTase, NSP14, an essential enzyme for SARS-CoV-2 to methylate the N7 position of viral 5'-RNA guanine cap. The assay is universal and suitable for any SAM-dependent viral MTases such as the SARS-CoV-2 NSP16/NSP10 MTase complex and the NS5 MTase of Zika virus (ZIKV). Pilot screening demonstrated that the HTS assay was very robust and identified two candidate inhibitors, NSC 111552 and 288387. The two compounds inhibited the FL-NAH binding to the NSP14 MTase with low micromolar IC50. We used three functional MTase assays to unambiguously verified the inhibitory potency of these molecules for the NSP14 N7-MTase function. Binding studies indicated that these molecules are bound directly to the NSP14 MTase with similar low micromolar affinity. Moreover, we further demonstrated that these molecules significantly inhibited the SARS-CoV-2 replication in cell-based assays at concentrations not causing cytotoxicity. Furthermore, NSC111552 significantly synergized with known SARS-CoV-2 drugs including nirmatrelvir and remdesivir. Finally, docking suggested that these molecules bind specifically to the SAM-binding site on the NSP14 MTase. Overall, these molecules represent novel and promising candidates to further develop broad-spectrum inhibitors for the management of viral infections.

Reticular Pseudodrusen: Interreader Agreement of Evaluation on OCT Imaging in Age-Related Macular Degeneration

Purpose

To determine the interreader agreement for reticular pseudodrusen (RPD) assessment on combined infrared reflectance (IR) and OCT imaging in the early stages of age-related macular degeneration across a range of different criteria to define their presence.

Design

Interreader agreement study.

Participants

Twelve readers from 6 reading centers.

Methods

All readers evaluated 100 eyes from individuals with bilateral large drusen for the following: (1) the presence of RPD across a range of different criteria and (2) the number of Stage 2 or 3 RPD lesions (from 0 to ≥ 5 lesions) on an entire OCT volume scan and on a selected OCT B-scan. Supportive information was available from the corresponding IR image.

Main Outcome Measures

Interreader agreement, as assessed by Gwet's first-order agreement coefficient (AC₁).

Results

When evaluating an entire OCT volume scan, there was substantial interreader agreement for the presence of any RPD, any or ≥ 5 Stage 2 or 3 lesions, and ≥ 5 definite lesions on en face IR images corresponding to Stage 2 or 3 lesions (AC₁ = 0.60-0.72). On selected OCT B-scans, there was also moderate-to-substantial agreement for the presence of any RPD, any or ≥ 5 Stage 2 or 3 lesions (AC₁ = 0.58-0.65) and increasing levels of agreement with increasing RPD stage (AC₁ = 0.08, 0.56, 0.78, and 0.99 for the presence of any Stage 1, 2, 3, and 4 lesions, respectively). There was substantial agreement regarding the number of Stage 2 or 3 lesions on an entire OCT volume scan (AC₁ = 0.68), but only fair agreement for this evaluation on selected B-scans (AC₁ = 0.30).

Conclusions

There was generally substantial or near-substantial-but not near-perfect-agreement for assessing the presence of RPD on entire OCT volume scans or selected B-scans across a range of differing RPD criteria. These findings underscore how interreader variability would likely contribute to the variability of findings related to the clinical associations of RPD. The low levels of agreement for assessing RPD number on OCT B-scans underscore the likely challenges of quantifying RPD extent with manual grading.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

A review of the reliability of remote neuropsychological assessment

The provision of clinical neuropsychological services has predominately been undertaken by way of standardized administration in a face-to-face setting. Interpretation of psychometric findings in this context is dependent on the use of normative comparison. When the standardization in which such psychometric measures are employed deviates from how they were employed in the context of the development of its associated norms, one is left to question the reliability and hence, validity of any such findings and in turn, diagnostic decision making. In light of the current COVID-19 pandemic and resultant social distancing direction, face-to-face neuropsychological assessment has been challenging to undertake. As such, remote (i.e., virtual) neuropsychological assessment has become an obvious solution. Here, and before the results from remote neuropsychological assessment can be said to stand on firm scientific grounds, it is paramount to ensure that results garnered remotely are reliable and valid. To this end, we undertook a review of the literature and present an overview of the landscape. To date, the literature shows evidence for the reliability of remote administration and the clinical implications are paramount. When and where needed, neuropsychologists, psychometric technicians and examinees may no longer need to be in the same physical space to undergo an assessment. These findings are most relevant given the physical distancing practices because of COVID-19. And whilst remote assessment should never supplant face-to-face neuropsychological assessments, it does serve as a valid alternative when necessary.

Left Atrial Phasic Function via Cardiac Magnetic Resonance Imaging in Patients with Duchenne Muscular Dystrophy

Cardiac dysfunction is a leading cause of morbidity and mortality in Duchenne muscular dystrophy (DMD). Left atrial (LA) function is a poorly understood concept in this patient population, and research suggests underlying structural changes that could affect atrial function. Cardiac magnetic resonance (CMR) imaging may provide an important non-invasive approach to evaluating LA function. This study was a single center retrospective review of consecutive CMR studies over a 1 year period comparing LA phasic function within a cohort of DMD patients, and to those with structurally and functionally normal hearts. LA strain measurements including global reservoir, conduit, boost-pump strain, and LA volumes were obtained retrospectively. Spearman correlation analyses were performed on atrial strain measurements. 107 DMD and 79 normal CMR studies were included. The DMD cohort had worse systolic function (p < 0.001), smaller indexed max LA and left ventricular (LV) volumes (p < 0.001), and greater LA emptying fraction (p < 0.001). In the DMD cohort, emptying fraction decreased with advanced patient age (p < 0.001) and diminishing systolic function (p < 0.001). DMD patients with moderate or severe LV dysfunction demonstrated lower LA emptying fraction (p = 0.002), more impaired 2-chamber LA reservoir (p = 0.003), and LA pump (p = 0.006) and conduit strain (p = 0.018). DMD patients with preserved function have lower indexed LA volumes with higher LA emptying fractions than controls. Progression of disease and age is associated with decreased LA emptying fraction with early manifestations in reservoir and conduit strain. These findings suggest that strain markers of LA compliance and early left ventricular relaxation are associated with worsening cardiomyopathy in the DMD population.

BNT162b2 versus mRNA-1273 Third Dose COVID-19 Vaccine in Patients with CKD and Maintenance Dialysis Patients

BACKGROUND

There is a lack of randomized controlled trial data regarding differences in immunogenicity of varying coronavirus disease 2019 (COVID-19) mRNA vaccine regimens in CKD populations.

METHODS

We conducted a randomized controlled trial at three kidney centers in Toronto, Ontario, Canada, evaluating the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody response after third dose vaccination. Participants ( n =273) with CKD not on dialysis or receiving dialysis were randomized 1:1 to third dose 30- µ g BNT162b2 (Pfizer-BioNTech) or 100- µ g mRNA-1273 (Moderna). The primary outcome of this study was SARS-CoV-2 IgG-binding antibodies to the receptor-binding domain (anti-RBD). Spike protein (antispike), nucleocapsid protein, and vaccine reactogenicity were also evaluated. Serology was measured before third dose and 1, 3, and 6 months after third dose. A subset of participants ( n =100) were randomly selected to assess viral pseudovirus neutralization against wild-type D614G, B.1.617.2 (Delta), and B.1.1.529 (Omicron BA.1).

RESULTS

Among 273 participants randomized, 94% were receiving maintenance dialysis and 59% received BNT162b2 for initial two dose COVID-19 vaccination. Third dose of mRNA-1273 was associated with higher mean anti-RBD levels (1871 binding antibody units [BAU]/ml; 95% confidence interval [CI], 829 to 2988) over a 6-month period in comparison with third dose BNT162b2 (1332 BAU/ml; 95% CI, 367 to 2402) with a difference of 539 BAU/ml (95% CI, 139 to 910; P = 0.009). Neither antispike levels nor neutralizing antibodies to wild-type, Delta, and Omicron BA.1 pseudoviruses were statistically different. COVID-19 infection occurred in 10% of participants: 15 (11%) receiving mRNA-1273 and 11 (8%) receiving BNT162b2. Third dose BNT162b2 was not associated with a significant different risk for COVID-19 in comparison with mRNA-1273 (hazard ratio, 0.78; 95% CI, 0.27 to 2.2; P = 0.63).

CONCLUSIONS

In patients with CKD, third dose COVID-19 mRNA vaccination with mRNA-1273 elicited higher SARS-CoV-2 anti-RBD levels in comparison with BNT162b2 over a 6-month period.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

COVID-19 Vaccine Boosters in Patients With CKD (BOOST KIDNEY), NCT05022329 .

Evaluation of a commonly used tool: Does the 5-item frailty index predict phenotypic frailty?

BACKGROUND

The simplified frailty index (sFI) is a commonly used instrument to estimate postoperative risk, but its correlation with phenotypic frailty has been questioned. This study evaluates the relationship between sFI and phenotypic frailty, as measured by the Sinai Abbreviated Geriatric Evaluation (SAGE).

METHODS

Charts were retrospectively reviewed from patients ≥75 years old who underwent surgery between 2012-2022. The sFI score was calculated by adding 1 point for hypertension, COPD, congestive heart failure, functional dependence, and diabetes (score 0-5). SAGE was calculated by adding 1 point for normal gait speed, normal Mini-Cog©, and independent activities of daily living (ADL) (0-3). Spearman rank correlation was used to test the relationship between sFI and SAGE. SAGE components were used as binary-dependent outcomes in covariate-adjusted logistic regression modeling to evaluate associations with sFI scores while adjusting for potential confounders.

RESULTS

334 patients were assessed, with a mean age of 84.0. SAGE and sFI scores were significantly associated, with a modest inverse relationship (r=-0.24, p<0.0001). Each 1-point increase in sFI score was associated with increased odds of ADL deficit (OR 2.3, 95%CI [1.5-3.8], p<0.0001) and abnormal gait speed (OR 1.9, 95%CI 1.2-3.0, p<0.01). The sFI score was not associated with deficits in the Mini-Cog (OR 1.5, 95%CI [0.96-2.3], p=0.07).

CONCLUSION

Higher sFI was significantly associated with increased phenotypic frailty, particularly with the loss of physical condition and function but not associated with cognitive deficit. Therefore, sFI may not be an appropriate tool to estimate postoperative complications related to cognition, such as delirium risk.

Design and development of microformulations for rapid release of small molecules and oligonucleotides

A systemic delivery of therapeutics frequently results in sub-optimal exposure of the targeted locus and undesired side effects. To address these challenges, a platform for local delivery of diverse therapeutics by remotely controlled magnetic micro-robots was introduced. The approach involves micro-formulation of active molecules using hydrogels that exhibit wide range of loading capabilities and predictable release kinetics. This work introduces two specific hydrogels based on thiol-maleimide and PEG-PLA-diacrylate chemistries that afford high, reliable and reproducible loading and release of several model molecules including doxorubicin, 25-mer poly-dT oligonucleotide and a 5.4 kBp GFP DNA plasmid. The described formulations are suitable for micro-dosing using both conventional or remote delivery devices.

Chemical probes and methods for the study of protein arginine methylation

Protein arginine methylation is a widespread post-translational modification (PTM) in eukaryotic cells. This chemical modification in proteins functionally modulates diverse cellular processes from signal transduction, gene expression, and DNA damage repair to RNA splicing. The chemistry of arginine methylation entails the transfer of the methyl group from S-adenosyl-l-methionine (AdoMet, SAM) onto a guanidino nitrogen atom of an arginine residue of a target protein. This reaction is catalyzed by about 10 members of protein arginine methyltransferases (PRMTs). With impacts on a variety of cellular processes, aberrant expression and activity of PRMTs have been shown in many disease conditions. Particularly in oncology, PRMTs are commonly overexpressed in many cancerous tissues and positively correlated with tumor initiation, development and progression. As such, targeting PRMTs is increasingly recognized as an appealing therapeutic strategy for new drug discovery. In the past decade, a great deal of research efforts has been invested in illuminating PRMT functions in diseases and developing chemical probes for the mechanistic study of PRMTs in biological systems. In this review, we provide a brief developmental history of arginine methylation along with some key updates in arginine methylation research, with a particular emphasis on the chemical aspects of arginine methylation. We highlight the research endeavors for the development and application of chemical approaches and chemical tools for the study of functions of PRMTs and arginine methylation in regulating biology and disease.

Blackfoot Words: a database of Blackfoot lexical forms

This paper describes the structure and creation of Blackfoot Words, a new relational database of lexical forms (inflected words, stems, and morphemes) in Blackfoot (Algonquian; ISO 639-3: bla). To date, we have digitized 63,493 individual lexical forms from 30 sources, representing all four major dialects, and spanning the years 1743-2017. Version 1.1 of the database includes lexical forms from nine of these sources. This project has two aims. The first is to digitize and provide access to the lexical data in these sources, many of which are difficult to access and discover. The second is to organize the data so that connections can be made between instances of the "same" lexical form across all sources, despite variation across sources in the dialect recorded, orthographic conventions, and the depth of morpheme analysis. The database structure was developed in response to these aims. The database comprises five tables: Sources, Words, Stems, Morphemes, and Lemmas. The Sources table contains bibliographic information and commentary on the sources. The Words table contains inflected words in the source orthography. Each word is broken down into stems and morphemes which are entered into the Stems and Morphemes tables in the source orthography. The Lemmas table contains abstract versions of each stem or morpheme in a standardized orthography. Instances of the same stem or morpheme are linked to a common lemma. We expect that the database will support projects by the language community and other researchers.

Geographically skewed recruitment and COVID-19 seroprevalence estimates: a cross-sectional serosurveillance study and mathematical modelling analysis

OBJECTIVES

Convenience sampling is an imperfect but important tool for seroprevalence studies. For COVID-19, local geographic variation in cases or vaccination can confound studies that rely on the geographically skewed recruitment inherent to convenience sampling. The objectives of this study were: (1) quantifying how geographically skewed recruitment influences SARS-CoV-2 seroprevalence estimates obtained via convenience sampling and (2) developing new methods that employ Global Positioning System (GPS)-derived foot traffic data to measure and minimise bias and uncertainty due to geographically skewed recruitment.

DESIGN

We used data from a local convenience-sampled seroprevalence study to map the geographic distribution of study participants' reported home locations and compared this to the geographic distribution of reported COVID-19 cases across the study catchment area. Using a numerical simulation, we quantified bias and uncertainty in SARS-CoV-2 seroprevalence estimates obtained using different geographically skewed recruitment scenarios. We employed GPS-derived foot traffic data to estimate the geographic distribution of participants for different recruitment locations and used this data to identify recruitment locations that minimise bias and uncertainty in resulting seroprevalence estimates.

RESULTS

The geographic distribution of participants in convenience-sampled seroprevalence surveys can be strongly skewed towards individuals living near the study recruitment location. Uncertainty in seroprevalence estimates increased when neighbourhoods with higher disease burden or larger populations were undersampled. Failure to account for undersampling or oversampling across neighbourhoods also resulted in biased seroprevalence estimates. GPS-derived foot traffic data correlated with the geographic distribution of serosurveillance study participants.

CONCLUSIONS

Local geographic variation in seropositivity is an important concern in SARS-CoV-2 serosurveillance studies that rely on geographically skewed recruitment strategies. Using GPS-derived foot traffic data to select recruitment sites and recording participants' home locations can improve study design and interpretation.

Determining the Longitudinal Serologic Response to COVID-19 Vaccination in the Chronic Kidney Disease Population: A Clinical Research Protocol

Background

People living with chronic kidney disease (CKD) have been disproportionately affected by the coronavirus disease 2019 (COVID-19) pandemic, including higher rates of infection, hospitalization, and death. Data on responsiveness to COVID-19 vaccination strategies and immunogenicity are limited, yet required to inform vaccination strategies in this at-risk population.

Objective

The objective of this study is to characterize the longitudinal serologic response to COVID-19 vaccination.

Design

This is a prospective observational cohort study.

Setting

Participating outpatient kidney programs within Ontario and British Columbia.

Patients

Up to 2500 participants with CKD G3b-5D receiving COVID-19 vaccination, including participants receiving dialysis and kidney transplant recipients (CKD G1T-5T).

Measurements

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies (anti-spike, anti-receptor binding domain, anti-nucleocapsid) will be detected by ELISA (enzyme-linked immunosorbent assay) from serum or dried blood spot testing. In a subset of participants, neutralizing antibodies against novel variants of concern will be evaluated. Peripheral blood mononuclear cells will be collected for exploratory immune profiling of SARS-CoV-2 specific cellular immunity.

Methods

Participants will be recruited prior to or following any COVID-19 vaccine dose and have blood sampled for serological testing at multiple timepoints: 1, 3, 6, 9, and 12 months post vaccination. When possible, samples will be collected prior to a dose or booster. Participants will remain in the study for at least 1 year following their last COVID-19 vaccine dose.

Strengths and limitations

The adaptive design of this study allows for planned modification based on emerging evidence or rapid changes in public health policy surrounding vaccination. Limitations include incomplete earlier timepoints for blood collection due to rapid vaccination of the population.

Conclusions

This large multicenter serologic study of participants living with kidney disease will generate data on the kinetics of SARS-CoV-2 immune response to vaccination across the spectrum of CKD, providing insights into the amplitude and duration of immunity conferred by COVID-19 vaccination and allowing for characterization of factors associated with immune response. The results of this study may be used to inform immunization guidelines and public health recommendations for the 4 million Canadians living with CKD.

Temperature-controlled Laminar Airflow (TLA) in symptomatic severe asthma – a post hoc analysis of severe exacerbations, quality of life and health economics

Purpose

Uncontrolled severe asthma constitutes a major economic burden to society. Add-ons to standard inhaled treatments include inexpensive oral corticosteroids and expensive biologics. Nocturnal treatment with Temperature-controlled Laminar Airflow (TLA; Airsonett®) could be an effective, safe and cheaper alternative. The potential of TLA in reducing severe asthma exacerbations was addressed in a recent randomised placebo-controlled trial (RCT) in patients with severe asthma (Global Initiative for Asthma (GINA) step 4/5), but the results were inconclusive. We re-analysed the RCT with severe exacerbations stratified by the level of baseline asthma symptoms and Quality of Life.

Methods

More uncontrolled patients, defined by Asthma Control Questionnaire 7 (ACQ7) > 3, EuroQoL 5-Dimension Questionnaire Visual Analogue Scale (EQ5D-VAS) ≤ 65 and Asthma Quality of Life Questionnaire (AQLQ) ≤ 4 were selected for re-analysis. The rates of severe asthma exacerbations, changes in QoL and health-economics were analysed and compared between TLA and placebo.

Results

The study population included 226 patients (113 TLA / 113 placebo.) The rates of severe asthma exacerbations were reduced by 33, 31 and 25% (p = 0.083, 0.073, 0.180) for TLA compared to placebo, dependent on selected control measures (ACQ7, EQ5D-VAS, AQLQ, respectively). For patients with less control defined by AQLQ≤4, the difference in mean AQLQ0-12M between TLA and placebo was 0.31, 0.33, 0.26 (p = 0.085, 0.034, 0.150), dependent on selected covariate (AQLQ, EQ5D-VAS, ACQ7, respectively). For patients with poor control defined by ACQ7 > 3, the difference in EQ5D-5 L utility scores between TLA and placebo was significant at 9 and 12 months with a cost-effective ICER. The results from the original study did not demonstrate these differences.

Conclusion

This post hoc analysis demonstrated an effect of TLA over placebo on severe exacerbations, asthma control and health economics in a subgroup of patients with more symptomatic severe allergic asthma. The results are consistent with the present recommendations for TLA. However, these differences were not demonstrated in the full study. Several explanations for the different outcomes have been outlined, which should be addressed in future studies.

Funding

NIHR Health Technology Assessment Programme and Portsmouth Hospitals NHS Trust.

Synthesis and Activity of Triazole-Adenosine Analogs as Protein Arginine Methyltransferase 5 Inhibitors

Protein arginine methyltransferase 5 (PRMT5) is an attractive molecular target in anticancer drug discovery due to its extensive involvement in transcriptional control, RNA processing, and other cellular pathways that are causally related to tumor initiation and progression. In recent years, various compounds have been screened or designed to target either the substrate- or cofactor-binding site of PRMT5. To expand the diversity of chemotypes for inhibitory binding to PRMT5 and other AdoMet-dependent methyltransferases, in this work, we designed a series of triazole-containing adenosine analogs aimed at targeting the cofactor-binding site of PRMT5. Triazole rings have commonly been utilized in drug discovery due to their ease of synthesis and functionalization as bioisosteres of amide bonds. Herein, we utilized the electronic properties of the triazole ring as a novel way to specifically target the cofactor-binding site of PRMT5. A total of about 30 compounds were synthesized using the modular alkyne-azide cycloaddition reaction. Biochemical tests showed that these compounds exhibited inhibitory activity of PRMT5 at varying degrees and several showed single micromolar potency, with clear selectivity for PRMT5 over PRMT1. Docking-based structural analysis showed that the triazole ring plays a key role in binding to the characteristic residue Phe327 in the active pocket of PRMT5, explaining the compounds' selectivity for this type-II enzyme. Overall, this work provides new structure-activity relationship information on the design of AdoMet analogs for selective inhibition of PRMT5. Further structural optimization work will further improve the potency of the top leads.

Apical-out airway organoids as a platform for studying viral infections and screening for antiviral drugs

Airway organoids are polarized 3D epithelial structures that recapitulate the organization and many of the key functions of the in vivo tissue. They present an attractive model that can overcome some of the limitations of traditional 2D and Air–Liquid Interface (ALI) models, yet the limited accessibility of the organoids’ apical side has hindered their applications in studies focusing on host–pathogen interactions. Here, we describe a scalable, fast and efficient way to generate airway organoids with the apical side externally exposed. These apical-out airway organoids are generated in an Extracellular Matrix (ECM)-free environment from 2D-expanded bronchial epithelial cells and differentiated in suspension to develop uniformly-sized organoid cultures with robust ciliogenesis. Differentiated apical-out airway organoids are susceptible to infection with common respiratory viruses and show varying responses upon treatment with antivirals. In addition to the ease of apical accessibility, these apical-out airway organoids offer an alternative in vitro model to study host–pathogen interactions in higher throughput than the traditional air–liquid interface model.

Feasibility of Assessing Adolescent and Young Adult Heart Transplant Recipient Mental Health and Resilience Using Patient-Reported Outcome Measures

BACKGROUND

Although adolescents and young adults may be particularly prone to mental health symptoms after heart transplant, screening practices are variable.

OBJECTIVE

To assess the feasibility of using patient-reported outcome (PRO) measures to assess mental health, functional status, and resiliency in posttransplant adolescents and young adult patients.

METHODS

Patients transplanted between ages 15 and 25 years at 3 centers completed 6 PRO instruments via web-based platforms: PROMIS instruments for anxiety, depression, satisfaction with social roles, and physical functioning; the Posttraumatic Stress Diagnostic Scale for Diagnostic and Statistical Manual of Mental Disorders, version 5; and the Connor-Davidson Resilience Scale-10. Feasibility (completion, time to completion, and measure missingness) and PRO results were described and compared between patients with congenital heart disease and cardiomyopathy.

RESULTS

Nineteen patients (median age at transplant 17.7 y [interquartile range 16.3, 19.2 y], 84% male) were enrolled at an average of 3 ± 1.8 years after transplant. Enrollment was 90% among eligible patients. Measure missingness was zero. The average completion time was 12 ± 15 minutes for all instruments. Timely PRO completion was facilitated by in-clinic application. The PRO results indicated that 9 patients (47%) had at least mild posttraumatic stress disorder symptoms (≥11 points on Posttraumatic Stress Diagnostic Scale for Diagnostic and Statistical Manual of Mental Disorders, version 5). Among them, 4 patients had scores >28 suggestive of probable posttraumatic stress disorder. Two (11%) and 6 (32%) patients had anxious and depressive symptoms, respectively. The cardiomyopathy cohort had a higher median Posttraumatic Stress Diagnostic Scale for Diagnostic and Statistical Manual of Mental Disorders, version 5 score than that of the congenital heart disease subgroup (11.0 vs 6.0; P = 0.015). Twelve (63%) had resiliency scores that were lower than the population average. No significant differences were found in PRO results between patients with cardiomyopathy and congenital heart disease apart from the posttraumatic stress disorder assessment.

CONCLUSIONS

This novel PRO-based approach to psychiatric screening of adolescents and young adult patients after transplant appears feasible for assessing mental health, functional status, and resiliency, with excellent enrollment and completion rates. These instruments characterized the burden of mental health symptoms within this adolescents and young adult heart transplant cohort, with a high prevalence of posttraumatic stress disorder symptoms. Resiliency scores were lower than in a comparison population. Electronically-administered PRO administration could facilitate more consistent mental health screening in this at-risk group.

Impact of Digoxin Use on Interstage Outcomes of Single Ventricle Heart Disease (From a NPC-QIC Registry Analysis)

Digoxin has been associated with lower interstage mortality (ISM) following stage 1 palliation (S1P). Despite a substantial increase in digoxin use nationally, ISM has not declined. We aimed to determine the impact of digoxin on ISM in the current era. This study analyzed data from the National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC) registry. All patients who survived to hospital discharge following S1P were included. Comparisons were made between pre-specified eras (1: 2010-2015, 2: 2016-2019) based on digoxin use. ISM risk was estimated using the previously published NEONATE score (excluding digoxin). Multivariable Cox proportional hazard models assessed the impact of digoxin on ISM and freedom from unplanned readmission in era 2. A total of 1400 (46.8%) patients were included from era 1 and 1589 (53.2%) from era 2. Digoxin use (22.4% vs 61.7%, p < 0.001) and the proportion of high-risk patients (9.1% vs 20.3%, p < 0.001) increased across eras. There was no difference in predicted ISM risk between those who did vs did not receive digoxin in era 2 (p = 0.82). In era 2, digoxin use was independently associated with lower ISM (AHR 0.60, 95%CI 0.36 to 0.98, p = 0.043) and greater freedom from unplanned readmission (AHR 0.44, 95%CI 0.32 - 0.59, p < 0.001). In conclusion, digoxin is independently associated with lower ISM and greater freedom from interstage readmission. The lack of improvement in overall ISM in the current era may be secondary to a greater proportion of high-risk patients and/or disproportionately higher digoxin use in lower risk patients, who may not derive the same benefit.

Characteristics of Restart a Heart 2019 event locations in the UK

Introduction

Restart a Heart (RSAH) is an annual CPR mass training initiative delivered predominantly by ambulance services in the UK. The aim of this study was to identify to what extent voluntary participation in the 2019 initiative delivered training to the population with the highest need.

Methods

A cross-sectional observational study of location characteristics for RSAH training events conducted by UK ambulance services. Descriptive statistics were used to analyse event and area characteristics. National cardiac arrest registry data were used to establish proportions of training coverage in “hot spot” areas with above national median incidence of cardiac arrest and below median bystander CPR rates. The significance of observed differences were tested using chi-square for proportions and t-test for means.

Results

Twelve of 14 UK ambulance services participated, training 236,318 people. Most of the events (82%) were held in schools, and schoolchildren comprised most participants (81%). RSAH events were held in areas that were less densely populated (p < 0.001), were more common in affluent areas (p < 0.001), and had a significantly lower proportion of black residents (p < 0.05) and higher proportion of white residents (p < 0.05). Events were held in 28% of known “hot spot” areas in England.

Conclusion

With mandatory CPR training for school children in England, Scotland and Wales there is an opportunity to re-focus RSAH resources to deliver training for all age groups in OHCA “hot spots”, communities with higher proportions of black residents, and areas of deprivation. In Northern Ireland, we recommend targeting schools in areas with similar characteristics.

Accelerated Idioventricular Rhythm: A Rare Case of Wide-Complex Dysrhythmia in a Teenager

BACKGROUND

Accelerated idioventricular rhythm (AIVR) is an uncommon and typically benign dysrhythmia with similarities to more malignant forms of ventricular tachycardia (VT). It is often seen in adults after myocardial infarctions, although it also arises in the newborn period, as well as in children with and without congenital heart disease.

CASE REPORT

We describe a presentation of AIVR in an otherwise healthy 13-year-old girl, discovered on arrival to the pediatric emergency department in the setting of post-tonsillectomy bleeding. The case reviews the diagnostic criteria of AIVR, associated symptoms, the pathophysiologic origin of AIVR, and potential treatment strategies. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Given its morphologic similarities to life-threatening forms of VT, AIVR can be misdiagnosed in the emergency department or primary care settings. With an understanding of the dysrhythmia's unique features, emergency physicians can avoid unnecessary interventions and provide the correct diagnosis, workup, and management of AIVR for pediatric patients.

Effects of substrate modifications on the arginine dimethylation activities of PRMT1 and PRMT5

Histone arginine methylation is a prevalent posttranslational modification (PTM) in eukaryotic cells and contributes to the histone codes for epigenetic regulation of gene transcription. In this study, we determined how local changes on adjacent residues in the histone H4 substrate regulate arginine asymmetric dimethylation and symmetric dimethylation catalysed by the major protein arginine methyltransferase (PRMT) enzymes PRMT1 and PRMT5, respectively. We found that phosphorylation at histone H4 Ser-1 site (H4S1) was inhibitory to activities of PRMT1 and PRMT5 in both monomethylating and dimethylating H4R3. Also, a positively charged H4K5 was important for PRMT1 catalysis because acetylation of H4K5 or the loss of the H4K5 ε-amine had a similar effect in reducing the catalytic efficiency of asymmetric dimethylation of H4R3. An opposite effect was observed in that acetylation of H4K5 or the loss of the H4K5 ε-amine enhanced PRMT5-mediated symmetric dimethylation of H4R3. Furthermore, we observed that N-terminal acetylation of H4 modestly decreased asymmetric dimethylation of H4R3 by PRMT1 and symmetric dimethylation of H4R3 by PRMT5. This work highlights the significance of local chemical changes in the substrate to regulating PRMT activity and unravels the pattern complexities and subtleties of histone codes.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Vancouver's inner-city youth: New approaches for a changing demographic

Introduction

Inner-city youth suffer a high burden of mental illness and seek health care on an episodic basis (McCreary, 2001).

These youth tend to receive limited support services due to a lack of continuity of care as they move from child to adult services. Other barriers include homelessness and substance use.

The Vancouver Inner City Youth Mental Health Program (ICYMHP) is a psychiatry led initiative to provide psychiatric services and further collaboration between inner-city youth agencies providing care to at risk youth.

Aims

To introduce and review a collaborative model of care between psychiatric services and community based organizations.

To review the demographics, presentations and outcomes of youth assessed through the ICYMHP.

Methods

A chart review of all clients assessed through the program from its inception (November 2007) to May 2009 (18 months).

Results

Results from clients seen between November 2007 and June 2008 indicate an incidence of psychosis of 40% in men and 21% in women. Mood disorders were the primary diagnosis in 18% of men and 29% of women. Active substance misuse is high (71% of men, cannabis as drug of choice; 54% of women, methamphetamine as drug of choice). Length of stay at Covenant House nearly tripled for those under the care of the ICYMH versus the general shelter population, a positive outcome (21 days versus 9).

Conclusions

Inner-city homeless youth suffer from a high burden of mental illness. A collaborative model of care exists to improve health care quality and delivery to this population.

Introduction of an enhanced recovery protocol into a laparoscopic living donor nephrectomy programme

INTRODUCTION

Living-donor renal transplantation is the optimal treatment for patients with end-stage renal disease. The rate of living donation in the UK is sub-optimal, and potential donor concerns regarding postoperative recovery may be contributory. Enhanced recovery programmes are well described for a number of surgical procedures, but experience in living-donor surgery is sparse. This study reports the impact of introducing an enhanced recovery protocol into a living-donor renal transplant programme.

MATERIALS AND METHODS

All consecutive patients undergoing laparoscopic living-donor nephrectomy over a 25-month period were included. The principles of enhanced recovery were fluid restriction, morphine sparing and expectation management. Outcome measures were postoperative pain scores and complications for donor and recipients.

RESULTS

Standard care was provided for 24 (30%) patients and 57 (70%) followed an enhanced recovery pathway. The latter group received significantly less preoperative intravenous fluid (0ml vs 841ml p < 000.1) and opiate medication (14.83mg vs 23.85mg p = 0.001). Pain scores, postoperative complications and recipient transplant outcomes were comparable in both groups.

CONCLUSIONS

Enhanced recovery for living-donor nephrectomy is a safe approach for donors and recipients. Application of these techniques and further refinement should be pursued to enhance the experience of living donors.

4313Evolocumab rapidly reverses impaired coronary endothelial function in six weeks in people living with HIV and in patients with dyslipidemia

Background/Introduction

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is well recognized for its importance in cholesterol metabolism. Elevated levels are associated with increased cardiovascular risk and inhibition with PCSK9 antibodies lowers cardiovascular events in patients with known coronary disease. PCSK9 levels are also elevated in people living with HIV (PLWH), and we previously reported that increased PCSK9 in PLWH is associated with impaired coronary endothelial function (CEF), a major driver for the development, progression, and clinical manifestations of coronary artery disease.

Purpose

Here we investigate the hypothesis that PCSK9 inhibition improves impaired CEF in PLWH and in patients with dyslipidemia (DL).

Methods

Cine 3T MRI was used to noninvasively measure CEF, assessed as the change in coronary cross-sectional area (CSA) from rest to isometric handgrip exercise (IHE), a known endothelial-dependent vasodilator. Eight HIV+ subjects on stable highly active antiretroviral therapy and with undetectable HIV RNA (mean age 53±9 yrs, LDLC 98±18 mg/dL, 38% on statins) and ten patients with dyslipidemia (DL) without HIV receiving evolocumab for clinical reasons (mean age 56±10 yrs, LDLC 130±28 mg/dL, 50% on statins) underwent MRI studies before and six weeks following the initiation of evolocumab 420 mg. MRI readers were blinded to group and timepoint. MRI data are presented as mean±SD for % change rest vs IHE.

Results

Prior to evolucumab, resting CSA in the two groups did not differ and IHE did not induce normal coronary vasodilation in either group; mean stress-induced CSA changes were −2.1±6.4% in HIV (p=0.27) and −0.6±4.1% in DL (p=0.46). Notably, CEF significantly improved following six weeks of evolocumab with IHE-induced CSA changes of 7.6±5.7% (p=0.006) and 5.0±3.6% (p=0.002) in the HIV and DL groups, respectively. The %-LDLC reduction with evolocumab was profound and comparable in the HIV and DL groups, 73±5% and 60±6% (p=0.19 HIV vs. DL). There was no significant correlation between the extents of LDLC reduction and of CEF improvement in either of these modest sized groups.

Conclusion

PCSK9 inhibition with evolocumab significantly improves abnormal coronary endothelial function after only six weeks in HIV+ people with normal LDLC and in HIV- people with DL. To our knowledge, these data represent the earliest (6 weeks) evidence for improvement in human coronary artery health by PCSK9 inhibition.

Acknowledgement/Funding

Amgen provided the PCSK9 monoclonal antibody (evolocumab) for this study.

P5322Oxidized phospholipids on apolipoprotein B-100 among black US adults with and without PCSK9 loss-of-function variants

Background

High oxidized phospholipid-apolipoprotein B-100 (OxPL-apoB) levels are associated with an increased risk for coronary heart disease (CHD). Genetic PCSK9 loss-of-function (LOF) variants result in life-long lower levels of LDL-C and lipoprotein(a) and reduced CHD risk, but the association with OxPL-apoB is unknown.

Purpose

To estimate the association between PCSK9 LOF variants and OxPL-apoB levels among black adults.

Methods

Genotyping for LOF variants (Y142X and C679X) was conducted for 10,196 black Reasons for Geographic And Racial Differences in Stroke study participants. OxPL-apoB was measured using antibody E06 for all participants with LOF variants (n=241) and randomly selected participants, matched at a 1:3 ratio, without LOF variants (n=723). Low OxPL-apoB was defined as the bottom quartile of the population distribution (<1.6 nM). Prevalence ratios (PR) and 95% confidence intervals (CI) were calculated for the association between PCSK9 LOF variants and low OxPL-apoB levels adjusting for age, sex, and estimated glomerular filtration rate.

Results

Adults with versus without PCSK9 LOF variants had lower LDL-C and lipoprotein(a) and were less likely to be taking a statin. (Table) A higher proportion of adults with versus without PCSK9 LOF variants had low OxPL-apoB levels (30.3 vs 23.4, p=0.03). After adjustment for covariates, the PR of low OxPL-apoB was increased for participants with compared to without LOF variants (PR 1.31, 95% CI 1.00, 1.72).

Characteristics of REGARDS participants PCSK9 loss-of-function variant p-value Yes (n=241) No (n=723) Age, years, mean (SD) 63.7 (9.2) 63.8 (8.6) 0.81 Female, % 61.4 60.6 0.82 Diabetes, % 34.4 27.4 0.04 LDL-C, mg/dL, mean (SD) 85 (32) 118 (37) <0.001 Lp(a), nmol/L, median (25th, 75th percentile) 63.2 (30.4, 119.6) 80.4 (39.7, 138.4) 0.02 Statin use, % 13.3 30.4 <0.001 OxPL-apoB <1.6 nM, % 30.3 23.4 0.03 Abbreviations: LDL-C, low-density lipoprotein cholesterol; Lp(a), lipoprotein(a); LOF, loss-of-function; nM, nanomolar; OxPL-apoB, oxidized phospholipids on apolipoprotein B-100; PCSK9, proprotein convertase subtilisin/kexin type-9; REGARDS, REasons for Geographic And Racial Differences in Stroke; SD, standard deviation.

Conclusion

Among black adults, PCSK9 LOF variants were associated with lower OxPL-apoB levels.

Acknowledgement/Funding

Industry/academic collaboration between Amgen Inc., University of Alabama at Birmingham and the Icahn School of Medicine at Mt. Sinai; and U01NS041588

The Biological Axis of Protein Arginine Methylation and Asymmetric Dimethylarginine

Protein post-translational modifications (PTMs) in eukaryotic cells play important roles in the regulation of functionalities of the proteome and in the tempo-spatial control of cellular processes. Most PTMs enact their regulatory functions by affecting the biochemical properties of substrate proteins such as altering structural conformation, protein-protein interaction, and protein-nucleic acid interaction. Amid various PTMs, arginine methylation is widespread in all eukaryotic organisms, from yeasts to humans. Arginine methylation in many situations can drastically or subtly affect the interactions of substrate proteins with their partnering proteins or nucleic acids, thus impacting major cellular programs. Recently, arginine methylation has become an important regulator of the formation of membrane-less organelles inside cells, a phenomenon of liquid-liquid phase separation (LLPS), through altering π-cation interactions. Another unique feature of arginine methylation lies in its impact on cellular physiology through its downstream amino acid product, asymmetric dimethylarginine (ADMA). Accumulation of ADMA in cells and in the circulating bloodstream is connected with endothelial dysfunction and a variety of syndromes of cardiovascular diseases. Herein, we review the current knowledge and understanding of protein arginine methylation in regards to its canonical function in direct protein regulation, as well as the biological axis of protein arginine methylation and ADMA biology.

Simulating Transplant Small-for-size Grafts Using Human Liver Monosegments: The Impact of Portal Perfusion Pressure

Small-for-size-liver grafts (SFSG) in adult transplant recipients have elevated risk of graft failure, limiting its application in clinical liver transplantation. Relevant preclinical model of SFSG is lacking. Relevant to deceased-donor split liver transplant and living-donor liver transplant in adult recipients, in this study, we present our initial characterization of SFSG model using monosegments of a discarded human donor liver.