Metabolism-driven in vitro/in vivo disconnect of an oral ERɑ VHL-PROTAC

Targeting the estrogen receptor alpha (ERα) pathway is validated in the clinic as an effective means to treat ER+ breast cancers. Here we present the development of a VHL-targeting and orally bioavailable proteolysis-targeting chimera (PROTAC) degrader of ERα. In vitro studies with this PROTAC demonstrate excellent ERα degradation and ER antagonism in ER+ breast cancer cell lines. However, upon dosing the compound in vivo we observe an in vitro-in vivo disconnect. ERα degradation is lower in vivo than expected based on the in vitro data. Investigation into potential causes for the reduced maximal degradation reveals that metabolic instability of the PROTAC linker generates metabolites that compete for binding to ERα with the full PROTAC, limiting degradation. This observation highlights the requirement for metabolically stable PROTACs to ensure maximal efficacy and thus optimisation of the linker should be a key consideration when designing PROTACs.

Reducing short-acting beta-agonist use in asthma: Impact of national incentives on prescribing practices in England and the findings from SENTINEL Plus early adopter sites

Short-acting beta-agonist (SABA) over-use in asthma is harmful for patients and the environment. The Investment and Impact Fund (IIF) 2022/2023 financially rewarded English primary care networks that achieved specific targets, including reducing SABA over-use (RESP-02) and lowering the mean carbon footprint per salbutamol inhaler prescribed (ES-02). SENTINEL Plus is a co-designed quality improvement package that aims to improve asthma outcomes and reduce asthma's environmental impact by addressing SABA over-use. We investigated the impact of (i) the IIF incentives and (ii) SENTINEL Plus implementation on asthma prescribing. Using Openprescribing.net data, we demonstrate that IIF 2022-2023 had no significant impact on the total number of SABA prescribed in England (25,927,252 during 12-months pre- and 25,885,213 12-months post-IIF; 0.16% decrease; p=NS), but lower carbon footprint SABA inhaler use increased (Salamol™ prescribing increased from 5.1% to 19% of SABA prescriptions, p < 0.01). In contrast, SENTINEL Plus sites significantly reduced SABA prescribing post-implementation (5.43% decrease, p < 0.05).

"Primer shot" fractionation with an early treatment break is theoretically superior to consecutive weekday fractionation schemes for early-stage non-small cell lung cancer

PURPOSE

Radiotherapy is traditionally given in equally spaced weekday fractions. We hypothesize that heterogeneous interfraction intervals can increase radiosensitivity via reoxygenation. Through modeling, we investigate whether this minimizes local failures and toxicity for early-stage non-small cell lung cancer (NSCLC).

METHODS

Previously, a tumor dose-response model based on resource competition and cell-cycle-dependent radiosensitivity accurately predicted local failure rates for early-stage NSCLC cohorts. Here, the model mathematically determined non-uniform inter-fraction intervals minimizing local failures at similar normal tissue toxicity risk, i.e., iso-BED3 (iso-NTCP) for fractionation schemes 18Gyx3, 12Gyx4, 10Gyx5, 7.5Gyx8, 5Gyx12, 4Gyx15. Next, we used these optimized schedules to reduce toxicity risk (BED3) while maintaining stable local failures (TCP).

RESULTS

Optimal schedules consistently favored a "primer shot" fraction followed by a 2-week break, allowing tumor reoxygenation. Increasing or decreasing the assumed baseline hypoxia extended or shortened this optimal break by up to one week. Fraction sizes of 7.5 Gy and up required a single primer shot, while smaller fractions needed one or two extra fractions for full reoxygenation. The optimized schedules, versus consecutive weekday fractionation, predicted absolute LF reductions of 4.6%-7.4%, except for the already optimal LF rate seen for 18Gyx3. Primer shot schedules could also reduce BED3 at iso-TCP with the biggest improvements for the shortest schedules (94.6Gy reduction for 18Gyx3).

CONCLUSION

A validated simulation model clearly supports non-standard "primer shot" fractionation, reducing the impact of hypoxia-induced radioresistance. A limitation of this study is that primer-shot fractionation is outside prior clinical experience and therefore will require clinical studies for definitive testing.

Natural history of occult hernias in adults at a safety-net hospital

PURPOSE

Occult hernias, hernias seen on radiologic imaging but not felt on physical exam, are common. Despite their high prevalence, little is known about the natural history of this finding. Our aim was to determine and report on the natural history of patients with occult hernias including the impact on abdominal wall quality of life (AW-QOL), need for surgery, and risk of acute incarceration/strangulation.

METHODS

This was a prospective cohort study of patients who underwent a computed tomography (CT) abdomen/pelvis scan from 2016 to 2018. Primary outcome was change in AW-QOL using the modified Activities Assessment Scale (mAAS), a hernia-specific, validated survey (1 = poor, 100 = perfect). Secondary outcomes included elective and emergent hernia repairs.

RESULTS

A total of 131 (65.8%) patients with occult hernias completed follow-up with a median (IQR) of 15.4 (22.5) months. Nearly half of these patients (42.8%) experienced a decrease in their AW-QOL, 26.0% were unchanged, and 31.3% reported improvement. One-fourth of patients (27.5%) underwent abdominal surgery during the study period: 9.9% were abdominal procedures without hernia repair, 16.0% involved elective hernia repairs, and 1.5% were emergent hernia repairs. AW-QOL improved for patients who underwent hernia repair (+ 11.2 ± 39.7, p = 0.043) while those who did not undergo hernia repair experienced no change in AW-QOL (- 3.0 ± 35.1).

CONCLUSION

When untreated, patients with occult hernias on average experience no change in their AW-QOL. However, many patients experience improvement in AW-QOL after hernia repair. Additionally, occult hernias have a small but real risk of incarceration requiring emergent repair. Further research is needed to develop tailored treatment strategies.

A cost minimisation analysis comparing oral linezolid and intravenous daptomycin administered via an outpatient parenteral antibiotic therapy programme in patients requiring prolonged antibiotic courses

This study is an economic analysis seeking to examine cost savings that may be accrued from usage of oral linezolid in place of OPAT IV daptomycin in patients requiring prolonged courses of IV or highly bioavailable oral antibiotic therapy. In order to do so we conducted a literature review to establish the scenarios in which the agents could be considered equivalent. We then, using a decision-tree model, conducted a cost analysis to establish differences in cost between the approaches. Under the model base-case, the total cost of treatment with OPAT daptomycin was €3,496.84 and the total cost of treatment with oral linezolid was €772.01. Therefore the oral linezolid strategy would be projected to save the Irish health service €2,724.83 per patient. These results were robust to one-way deterministic sensitivity analyses and probabilistic sensitivity analysis. Our study suggests that significant savings could be safely accrued in the management of these patients.

Discovery of AZD4747, a Potent and Selective Inhibitor of Mutant GTPase KRASG12C with Demonstrable CNS Penetration

The glycine to cysteine mutation at codon 12 of Kirsten rat sarcoma (KRAS) represents an Achilles heel that has now rendered this important GTPase druggable. Herein, we report our structure-based drug design approach that led to the identification of 14, AZD4747, a clinical development candidate for the treatment of KRAS^G12C-positive tumors, including the treatment of central nervous system (CNS) metastases. Building on our earlier discovery of C5-tethered quinazoline AZD4625, excision of a usually critical pyrimidine ring yielded a weak but brain-penetrant start point which was optimized for potency and DMPK. Key design principles and measured parameters that give high confidence in CNS exposure are discussed. During optimization, divergence between rodent and non-rodent species was observed in CNS exposure, with primate PET studies ultimately giving high confidence in the expected translation to patients. AZD4747 is a highly potent and selective inhibitor of KRAS^G12C with an anticipated low clearance and high oral bioavailability profile in humans.

Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Closed-loop optogenetic control of the dynamics of neural activity in non-human primates

Electrical neurostimulation is effective in the treatment of neurological disorders, but associated recording artefacts generally limit its applications to open-loop stimuli. Real-time and continuous closed-loop control of brain activity can, however, be achieved by pairing concurrent electrical recordings and optogenetics. Here we show that closed-loop optogenetic stimulation with excitatory opsins enables the precise manipulation of neural dynamics in brain slices from transgenic mice and in anaesthetized non-human primates. The approach generates oscillations in quiescent tissue, enhances or suppresses endogenous patterns in active tissue and modulates seizure-like bursts elicited by the convulsant 4-aminopyridine. A nonlinear model of the phase-dependent effects of optical stimulation reproduced the modulation of cycles of local-field potentials associated with seizure oscillations, as evidenced by the systematic changes in the variability and entropy of the phase-space trajectories of seizures, which correlated with changes in their duration and intensity. We also show that closed-loop optogenetic neurostimulation could be delivered using intracortical optrodes incorporating light-emitting diodes. Closed-loop optogenetic approaches may be translatable to therapeutic applications in humans.

Experimental and computational studies of sulfided NiMo supported on pillared clay: catalyst activation and guaiacol adsorption sites

We report on intermediate (oxysulfides) and sulfided structures of NiMo supported on aluminium pillared clay (Al-PILC) during the catalyst activation process and the prefered guaiacol adsorption sites on the sulfided catalyst. In situ X-ray absorption fine structure (XAFS) together with density functional theory (DFT) calculations confirm the existence of ill-defined suboxides (MoO_x, NiO_x) and the well-known subsulfides (Mo₂S₉, Ni₃S₂) at the first stage which, at a later stage in the process, transform into MoS₂ with two edges, oxygen-decorated Mo and Ni with zero sulfur coverage. The freshly sulfided NiMoS₂ catalyst under sulfiding agents is mainly terminated by Mo-edge surface with 50% sulfur coverage (Mo-S50) with a disordered Ni-edge surface that can be assigned as NiMoS (1̄010). When exposed to an inert atmosphere such as He gas, the Mo and Ni edges evolved partially into new structures of Mo and Ni edges with zero sulfur coverage, labelled as Mo-Bare and Ni-Bare. Guaiacol is often used as a model compound for lignin and a series of calculations of guaiacol on the structural edges of a sulfided NiMoS₂ catalyst show relatively good agreement between the observed and calculated inelastic neutron scattering (INS) spectra for Mo-S50, Ni-Bare, and NiMoS (1̄010) where guaiacol weakly chemisorbed via oxygen atom of OH group. The results also confirm that guaiacol is physisorbed on the basal plane of NiMoS₂ in a horizontal (flat-lying) configuration via van der Waals interaction at a separation of about 3.25 Å.

Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months.

METHODS

We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed.

RESULTS

We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05).

CONCLUSION

While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.

Point-of-care NT-proBNP for the screening of PREGnancy-related Heart Failure – the PREG-HF study

Introduction

Cardiovascular disease is an important cause of maternal mortality worldwide. However, diagnosing heart failure (HF) during pregnancy remains challenging. Patients with HF present with symptoms that are often attributed to the physiological changes of pregnancy. Although the measurement of natriuretic peptides (such as NT-proBNP) has been recommended as a cost-effective screening test for HF, its value in predicting underlying structural heart disease on echocardiography during pregnancy is unclear.

Purpose

To evaluate the accuracy of point-of-care (POC) NT-proBNP to predict echocardiographic evidence of structural heart disease in pregnant women.

Methods

All consecutive consenting pregnant women with symptoms of HF (New York Heart Association functional class [NYHA FC] II–IV), who underwent echocardiography at Groote Schuur Hospital (a tertiary hospital in South Africa) between 1 March 2021 and 15 March 2022 were recruited and compared with asymptomatic pregnant women (NYHA FC I). Demographic and obstetric data were collected, as well as clinical and echocardiographic parameters. POC NT-proBNP was measured; a receiver operating characteristic (ROC) curve was used to determine the level of NT-proBNP that would have the best predictive value for detecting structural heart disease on echocardiography.

Results

We included 121 women with a median age of 31.3 years (IQR 24.9–36.4) and a median gravidity of 3 (2–4), mostly in their third trimester of pregnancy (75.2%). Symptomatic women (66.1%) presented mainly with dyspnoea (92.5%) and fatigue (73.8%). Most common signs of HF were peripheral oedema (46.8%), jugular venous distension (17.7%) and pulmonary crackles (17.7%). Overall, the median POC NT-proBNP was 98pg/ml (60–506) but was not statistically different between symptomatic and asymptomatic participants. However, NT-proBNP levels were significantly elevated in those with left ventricular (LV) dilatation (376 [86–744] vs 65 [60–191], p=0.001), left atrial enlargement (395 [65–744] vs 60 [59–108], p&lt;0.001), LV systolic dysfunction (510 [113–1668] vs 65 [60–210], p&lt;0.001), diastolic dysfunction (300 [77–1450] vs 78 [60–257], p=0.031), mitral regurgitation (167 [60–672] vs 78 [60–243], p=0.038) and pericardial effusion (440 [81–1031] vs 71 [60–243], p=0.011) (Figure 1). An NT-proBNP of &lt;200pg/ml had the highest negative predictive value (83%) to rule out structural heart disease (AUC 0.68 [0.59–0.77]). Patients with NT-proBNP of ≥200pg/ml were at increased risk of having echocardiographic evidence of structural heart disease (diagnostic odds ratio 4.9 [95% confidence interval 2.0–11.7]).

Conclusion

In this cohort of pregnant women with symptoms suggestive of HF, POC NT-proBNP identified those with structural heart disease with acceptable discrimination. POC NT-proBNP testing might be particularly useful as a screening test in settings where pregnant women do not readily have access to echocardiography.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): World Heart Federation Salim Yusuf Emerging Leaders Programme

Exploratory proteome profiling in patients with peripartum cardiomyopathy – a biomarker study on the EORP cohort

Background

The diagnosis of peripartum cardiomyopathy (PPCM) remains challenging as heart failure symptoms may also occur during normal pregnancy. This is further aggravated by the absence of biomarkers specific for diagnosis or prognosis of women with PPCM. Indeed, current evidence from the EURObservational Research Programme (EORP) Registry, an ongoing prospective, international, multicentre, observational registry for women with PPCM, report that the time to diagnosis after symptom onset varies from 19.4 to 38.3 days.

Aims

We performed exploratory serum proteome profiling on patients with PPCM, as compared with healthy postpartum mothers, to uncover novel protein biomarkers that would further our understanding of the pathogenesis of the disease and enhance diagnostic evaluation.

Methods

Demographic and clinical data, as well as serum samples were collected from 84 patients with PPCM from seven EORP participating countries and 29 healthy controls (HC) from South Africa. Serum proteomic profiling was conducted using DIA-based label-free quantitative (LFQ) LC-MS at the time of diagnosis from depleted serum samples. Mass spectrometry data were analyzed by Spectronaut v15 using a study-specific spectral library. Proteomic statistical analysis was performed using Perseus version 2.0.3.0 (FDR=0.05; S=0.1).

Results

Patients with PPCM had advanced heart failure (50% had New York Heart Association functional classes III/IV, mean left ventricular ejection fraction [LVEF] of 33.5%±9.3 [vs 57.0±8.8 in HC, p&lt;0.001]). Amongst the 329 proteins that were identified in the serum samples, 17 proteins were significantly differentially upregulated and 18 downregulated in patients with PPCM as compared to the HC (all p&lt;0.05; Figure 1). Adiponectin (log fold change 1.378, p=0.001), pregnancy-specific beta-1-glycoprotein 1 (1.207, p=0.022), disintegrin metalloproteinase domain-containing protein 12 (1.185, p=0.039), peptidyl-prolyl cis-trans isomerase (1.182, p=0.031) and sulfhydryl oxidase 1 (1.101, p=0.004) were among the upregulated proteins, whilst immunoglobulin kappa variable 2–29 (0.856, p=0.029), ficolin-3 (0.898, p=0.001), platelet basic protein (0.917, p=0.006) and thrombospondin-1 (0.930, p=0.043) were among the downregulated. Gene ontology indicated that thrombospondin receptor activity, fibronectin-binding, and vascular endothelial growth factor receptor 2 binding among the most significant regulated molecular functions. The area under the curve (AUC) of the top 10 up-regulated biomarkers ranged from 0.61–0.68 (p&lt;0.05).

Conclusion

Salient biological themes related to immune response proteins, inflammation, fibrosis, angiogenesis, apoptosis, and blood coagulation were identified to be predominant in PPCM versus HC. This indicates the complex pathophysiological mechanisms of PPCM. The newly identified proteins warrant further studies to evaluate their potential use as diagnostic and prognostic markers for PPCM.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): 1. EurObservational Research Programme in conjunction with the Heart Failure Association of the European Society of Cardiology Study Group on Peripartum Cardiomyopathy2. Cape Heart Institute, University of Cape Town, South Africa

Vancomycin-Resistant Enterococci in Patients Attending for Colonoscopy: An Estimate of Community Prevalence

Aims Ireland has the highest vancomycin-resistant Enterococcus faecium (VRE) bloodstream infection prevalence in Europe. Two patterns of VRE carriage are recognised. European, with widespread community prevalence and North American, where carriage is predominantly nosocomial. It is unclear which pattern is dominant in Ireland. This uncertainty limits infection control measures. This study sought to explore this issue via a cross sectional point prevalence study. Methods Asymptomatic community volunteers, represented by patients undergoing elective outpatient colonoscopy testing, were opportunistically screened for VRE. Demographic and risk factor data were collected via a patient survey. Rectal swabs were collected before colonoscopy and VRE was identified using the VITEK MS system. Results 102 patients were cultured. A single patient tested positive, representing a prevalence rate of 0.98% (95% CI &lt;0.01-5.8%). This patient demonstrated traditional risk factors, suggesting nosocomial rather than community acquisition. 94% (N=94) of patients had no knowledge of VRE, while 83% (N=83) had low levels of concern regarding hospital acquired infections. Conclusion There is a low incidence of VRE in the Irish community setting, in contrast to other European Countries, suggesting asymptomatic community colonization is not responsible for the high rates of VRE seen in Ireland. Wider screening or atypical infection control measures would not be supported by this data.

Whole genome sequence association analysis of fasting glucose and fasting insulin levels in diverse cohorts from the NHLBI TOPMed program

The genetic determinants of fasting glucose (FG) and fasting insulin (FI) have been studied mostly through genome arrays, resulting in over 100 associated variants. We extended this work with high-coverage whole genome sequencing analyses from fifteen cohorts in NHLBI's Trans-Omics for Precision Medicine (TOPMed) program. Over 23,000 non-diabetic individuals from five race-ethnicities/populations (African, Asian, European, Hispanic and Samoan) were included. Eight variants were significantly associated with FG or FI across previously identified regions MTNR1B, G6PC2, GCK, GCKR and FOXA2. We additionally characterize suggestive associations with FG or FI near previously identified SLC30A8, TCF7L2, and ADCY5 regions as well as APOB, PTPRT, and ROBO1. Functional annotation resources including the Diabetes Epigenome Atlas were compiled for each signal (chromatin states, annotation principal components, and others) to elucidate variant-to-function hypotheses. We provide a catalog of nucleotide-resolution genomic variation spanning intergenic and intronic regions creating a foundation for future sequencing-based investigations of glycemic traits.

A-39 Baseline And Initial Post-Injury Presentation Of Athletes With Self-Reported Neurodevelopmental Disorders As Measured By ImPACT

Purpose: To compare neurocognitive profiles of high school athletes with self-reported LD and/or ADHD neurodevelopmental disorders (ND) to controls at baseline (BL) and during initial post-injury (PI) testing with ImPACT. Methods: A sample of 155 (112 males, 43 females) high school athletes who completed BL and PI testing with ImPACT from 2019 to present was analyzed. Students who self-reported ND (n = 36) were compared to those who did not. ImPACT composites Verbal Memory (VM), Visual Memory (VisM), Visual Motor Speed (VMS), Reaction Time (RT), Impulse Control (IC), and Total Symptom Score (TSS) were measured as dependent variables. Data was analyzed using multiple one-way ANOVA’s accounting for gender and presence of ND as fixed factors. Results: One-way ANOVA (CI = 95%) revealed a five-point difference on BL-VMS between NDs and controls (p &lt; 0.001). ND students’ performance declined more after injury on VMS (p = 0.042). Analysis also showed ND PI-IC score about two points higher than controls (p = 0.014). With respect to gender, females reported greater symptoms on PI and more symptom increase than their male counterparts (p &lt; 0.001, p = 0.01; respectively). Lastly, ND males performed eight points lower on BL-VM than ND females (p = 0.031). Conclusions: The present study confirms that performance differences on ImPACT VMS may be expected between student-athletes with self-reported ND and their counterparts. Gender appears to contribute to performance on some measures of ImPACT; females endorse more symptoms than males PI, and ND males perform worse on BL-VM than ND females.

Discovery of AZD4625, a Covalent Allosteric Inhibitor of the Mutant GTPase KRASG12C

KRAS is an archetypal high-value intractable oncology drug target. The glycine to cysteine mutation at codon 12 represents an Achilles heel that has now rendered this important GTPase druggable. Herein, we report our structure-based drug design approach that led to the identification of 21, AZD4625, a clinical development candidate for the treatment of KRAS^G12C positive tumors. Highlights include a quinazoline tethering strategy to lock out a bio-relevant binding conformation and an optimization strategy focused on the reduction of extrahepatic clearance mechanisms seen in preclinical species. Crystallographic analysis was also key in helping to rationalize unusual structure-activity relationship in terms of ring size and enantio-preference. AZD4625 is a highly potent and selective inhibitor of KRAS^G12C with an anticipated low clearance and high oral bioavailability profile in humans.

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

Optimization of an Imidazo[1,2-a]pyridine Series to Afford Highly Selective Type I1/2 Dual Mer/Axl Kinase Inhibitors with In Vivo Efficacy

Inhibition of Mer and Axl kinases has been implicated as a potential way to improve the efficacy of current immuno-oncology therapeutics by restoring the innate immune response in the tumor microenvironment. Highly selective dual Mer/Axl kinase inhibitors are required to validate this hypothesis. Starting from hits from a DNA-encoded library screen, we optimized an imidazo[1,2-a]pyridine series using structure-based compound design to improve potency and reduce lipophilicity, resulting in a highly selective in vivo probe compound 32. We demonstrated dose-dependent in vivo efficacy and target engagement in Mer- and Axl-dependent efficacy models using two structurally differentiated and selective dual Mer/Axl inhibitors. Additionally, in vivo efficacy was observed in a preclinical MC38 immuno-oncology model in combination with anti-PD1 antibodies and ionizing radiation.

Effect of tibial plateau levelling osteotomy and rehabilitation on muscle function in cruciate-deficient dogs evaluated with acoustic myography

The objective of the study was to determine the function of the biceps femoris, quadriceps, gastrocnemius and semitendinosus muscles at the walk in dogs with unilateral clinical cruciate disease and palpable joint instability. To compare function before and after a tibial plateau levelling osteotomy (TPLO) procedure, and after six weeks of subsequent rehabilitation therapy. Fourteen adult client-owned dogs with cranial cruciate ligament deficiency (CCLD). Orthopaedic examination, temporospatial gait analysis and acoustic myography (AMG) recordings were made at three time points: before TPLO, and post-operatively at two and eight weeks. A rehabilitation program started 2 weeks after surgery and was either in-clinic along with in-home rehabilitation or in-home only. Statistics included: repeated measures ANOVA and paired t-tests. Significance was set at P<0.05. When comparing the affected versus the unaffected limb in the CCLD dogs, there were no significant differences found in AMG values between baseline and other time points for the quadriceps and semitendinosus muscles. The gastrocnemius and biceps femoris muscles had a significant change in spatial summation (S) score over time. The gastrocnemius (S) score was not significantly different to the unaffected limb by 8 weeks post TPLO. There was no significant effect of rehabilitation method on S score. Dogs with in-clinic rehabilitation regained more symmetry in thigh circumference versus in-home only. Lameness parameters improved but did not completely resolve in all dogs by week 8 post TPLO. The function of the gastrocnemius muscles in affected limbs was significantly different to normal limbs at baseline and 2 weeks post TPLO but not at 8 weeks. Thigh symmetry, but no other parameters, was improved with the addition of in-clinic rehabilitation.

An innovative outpatient monitor service for gynecological patients in the United Kingdom: Case study evaluation of clinical effectiveness, economic outcomes, patient safety, and service improvement

BACKGROUND

Failure to attend appointments places a huge strain on health care systems around the world, resulting in poorer care for the patients, waste of staff time and increased waiting times. This study looked at the impact of an Outpatient-Monitor-Service (OMS) on clinical, economic, patient safety and service improvement outcomes in gynaecology patients compared with care as usual (with no access to the OMS).

METHODS

We conducted a retrospective match-pair controlled study at a London-based hospital. The cohort included adult women who received either (i) gynecological, (ii) hysteroscopy or (iii) vulval procedures. A cost-consequences analysis compared intervention (who received the OMS) with control (historical cases who did not receive the OMS. Main outcome measures were clinical-effectiveness, NHS-cost, patient safety, and service improvement.

RESULTS

The intervention had positive impacts spanning clinical, patient safety and service improvement areas and showed cost saving results for the healthcare in terms of reduced follow-up consultations and did-not-attend occurrences.

CONCLUSIONS

The OMS offered by Message Dynamics appears to be a successful digital health technology to monitor gynecological patients' conditions and inform clinical decision making via remote channels, which is particularly relevant in coronavirus disease pandemic.

Throwing cardiac rehabilitation into the 21st Century: a focus group study exploring the impact of COVID-19 on cardiac rehabilitation delivery in Victoria, Australia

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiac rehabilitation (CR) education and exercise are predominantly delivered in group face-to-face settings. This delivery model was challenged during the COVID-19 pandemic due to government enforced lockdowns which restricted the delivery of these models of care. The Australian state of Victoria experienced the longest and most severe local restrictions and was in lockdown for approximately 26 weeks of 2020. 

Purpose

We aimed to explore the experience, barriers and enablers of delivering CR during a pandemic, and identify strategies for future COVID-safe programs among cardiac rehabilitation clinicians.

Methods

Victorian members of the Australian Cardiovascular Health and Rehabilitation Association (ACRA) were invited to attend an exploratory qualitative online focus group in November 2020. An inductive thematic analysis was undertaken before deductively applying the Non-adoption, Abandonment, Scale-up, Spread and Sustainability (NASSS) framework to identify barriers and enablers for technology adoption in CR.

Results

30 members participated in a 106 minute focus group. 17 members who provided demographics represented multiple disciplines (nursing n = 13, exercise physiology n = 3, physiotherapy n = 1) and geographical settings (metropolitan n = 10, regional n = 4, rural n = 3). Four main themes were identified: Consequences of sudden service delivery change; Technology use – challenges and benefits; Capacity (program and staff); and The way forward. The deductive NASSS analysis demonstrated the main challenges of continuing remotely delivered CR lie with all adopters (staff, patients, carers) and with organisations. Future CR strategies included the importance of resuming face-to-face programs but important barriers including finding capacity, particularly staffing, to run concurrent telehealth programs remain to be addressed. 

Conclusion

The COVID-19 pandemic forced and expedited significant changes to CR delivery models. While clinicians agreed that delivery of CR via telehealth will continue, it is now timely to review remote models of care and plan how they will integrate alongside traditional face-to-face programs.

Early-cannulation arteriovenous grafts are safe and effective in avoiding recurrent tunneled central catheter infection

Objective

Tunneled central venous catheter infection (TCVCi) is a common complication that often necessitates removal of the TCVC and a further TCVC. Theoeretically, insertion of an early-cannualtion graft (ecAVG) early after TCVC infection is possible but not widely practiced with concerns over safety and infection in the ecAVG. With 8 years of ecAVG experience, the aim of this study was to compare the outcomes following TCVC infection, comparing replacement with TCVC (TCVCr) versus immediate ecAVG (ecAVGr).

Methods

Retrospective comparison of two cohorts, who underwent replacement of an infected TCVC either by an early cannulation graft (n = 18) or by a further central catheter (n = 39).

Data were abstracted from a prospectively completed electronic patient record and collected on patient demographics, TCVC insertion, duration and infection, including culture proven bacteriaemia and subsequent access interventions.

Results

18/299 patients identified from 2012-2020 had an ecAVG implanted as treatment for a TCVCi. In a one-year time-period (1/1/2015 -31/12/2015) out of 222 TCVC inserted, 39 were as a replacement following a TCVCi. No patient with an ecAVGr developed an immediate infection, nor complication from the procedure. The rate of subsequent vascular access infection was significantly more frequent for those with TCVCr than with an ecAVGr (0.6 vs. 0.1/patient/ 1000 HD days, p &lt; 0.000). The number of further TCVC required was significantly higher in the TCVCr group (7.1 vs. 0.4/patient/ 1000 HD days, p = 0.000).

Conclusion

An ecAVG early following a TCVC infection is safe, reduces the incidence of subsequent infectious complications and reduces the number of TCVC required, with a better functional patency.

A Phase II Study of Biodegradable Stents Plus Palliative Radiotherapy in Oesophageal Cancer

AIMS

Self-expanding metal stents provide rapid improvement of dysphagia in oesophageal cancer but are associated with complications. The aim of the present study was to test the effectiveness of an alternative treatment of combining biodegradable stents with radiotherapy.

MATERIALS AND METHODS

A Simon two-stage single-arm prospective phase II trial design was used to determine the efficacy of biodegradable stents plus radiotherapy in patients with dysphagia caused by oesophagus cancer who were unsuitable for radical treatment. Fourteen patients were recruited and data from 12 were included in the final analyses.

RESULTS

Five of 12 patients met the primary end point: one stent-related patient death; four further interventions for dysphagia within 16 weeks of stenting (41.7%, 95% confidence interval 15.2-72.3%). The median time to a 10-point deterioration of quality of life was 2.7 weeks. Nine patients died within 52 weeks of registration. The median time to death from any cause was 15.0 weeks (95% confidence interval 9.6-not reached).

CONCLUSION

The high re-intervention observed, which met the pre-defined early stopping criteria, meant that the suggested alternative treatment was not sufficiently effective to be considered for a larger scale trial design. Further work is needed to define the place of biodegradable stents in the management of malignant oesophageal strictures.

Early-Cannulation Arteriovenous Grafts Are Safe and Effective in Avoiding Recurrent Tunneled Central Catheter Infection

OBJECTIVES

Tunneled central venous catheter infection (TCVCi) is a common complication that often necessitates removal of the TCVC and replacement by a further TCVC. Theoretically, insertion of an early - cannulation graft (ecAVG) early after TCVC infection is possible but not widely practiced with concerns over safety and infection in the ecAVG. With 8 years of ecAVG experience, the aim of this study was to compare the outcomes following TCVC infection, comparing replacement with TCVC (TCVCr) versus immediate ecAVG (ecAVGr).

DESIGN

Retrospective comparison of 2 cohorts, who underwent replacement of an infected TCVC either by an early cannulation graft (n = 18) or by a further central catheter (n = 39).

METHODS

Data were abstracted from a prospectively completed electronic patient record and collected on patient demographics, TCVC insertion, duration and infection, including culture proven bacteriaemia and subsequent access interventions.

RESULTS

Eighteen of 299 patients identified from 2012 to 2020 had an ecAVG implanted as treatment for a TCVCi. In a 1-year time-period (January 1, 2015-December 31, 2015) out of 222 TCVC inserted, 39 were as a replacement following a TCVCi. No patient with an ecAVGr developed an immediate infection, nor complication from the procedure. The rate of subsequent vascular access infection was significantly more frequent for those with a TCVCr than with an ecAVGr (0.6 vs. 0.1/patient/1000 HD days, P< 0.000). The number of further TCVC required was significantly higher in the TCVCr group (7.1 vs. 0.4/patient/1000 HD days, P= 0.000).

CONCLUSIONS

An ecAVG early following a TCVC infection is safe, reduces the incidence of subsequent infectious complications and reduces the number of TCVC required, with a better functional patency.

Clinical characteristics and outcome of critically ill COVID-19 patients with acute kidney injury: a single centre cohort study

BACKGROUND

Acute kidney injury (AKI) is a common manifestation among patients critically ill with SARS-CoV-2 infection (Coronavirus 2019) and is associated with significant morbidity and mortality. The pathophysiology of renal failure in this context is not fully understood, but likely to be multifactorial. The intensive care unit outcomes of patients following COVID-19 acute critical illness with associated AKI have not been fully explored. We conducted a cohort study to investigate the risk factors for acute kidney injury in patients admitted to and intensive care unit with COVID-19, its incidence and associated outcomes.

METHODS

We reviewed the medical records of all patients admitted to our adult intensive care unit suffering from SARS-CoV-2 infection from 14th March 2020 until 12th May 2020. Acute kidney injury was defined using the Kidney Disease Improving Global Outcome (KDIGO) criteria. The outcome analysis was assessed up to date as 3rd of September 2020.

RESULTS

A total of 81 patients admitted during this period. All patients had acute hypoxic respiratory failure and needed either noninvasive or invasive mechanical ventilatory support. Thirty-six patients (44%) had evidence of AKI (Stage I-33%, Stage II-22%, Renal Replacement Therapy (RRT)-44%). All patients with AKI stage III had RRT. Age, diabetes mellitus, immunosuppression, lymphopenia, high D-Dimer levels, increased APACHE II and SOFA scores, invasive mechanical ventilation and use of inotropic or vasopressor support were significantly associated with AKI. The peak AKI was at day 4 and mean duration of RRT was 12.5 days. The mortality was 25% for the AKI group compared to 6.7% in those without AKI. Among those received RRT and survived their illness, the renal function recovery is complete and back to baseline in all patients.

CONCLUSION

Acute kidney injury and renal replacement therapy is common in critically ill patients presenting with COVID-19. It is associated with increased severity of illness on admission to ICU, increased mortality and prolonged ICU and hospital length of stay. Recovery of renal function was complete in all survived patients.

Epidemiology of bloodstream infections in a Scottish haemodialysis population with focus on vascular access method

BACKGROUND

Infection is the second highest cause of mortality in end-stage renal disease, with a significant proportion relating to haemodialysis (HD) vascular access-related infection (VARI).

AIM

To report the rate and antimicrobial resistance (AMR) of all-source bloodstream infections (BSIs) by vascular access type in a Scottish HD cohort.

METHODS

Retrospective analysis was undertaken of data on adult patients attending seven HD units during 2017. Total HD days for each vascular access type were calculated. BSIs were analysed with rates expressed per 1000 HD days. AMR was verified using health board microbiology databases.

FINDINGS

Excluding contaminant organisms, there was an overall BSI rate of 0.57 per 1000 HD days. The highest all-source and vascular access-related infection (VARI) BSI rates per 1000 HD days were in the non-tunnelled central venous catheter (CVC) group (3.11 and 2.07 respectively), followed by tunnelled CVC (1.10 and 0.67), arteriovenous graft (0.51 and 0.31), and finally arteriovenous fistula (0.29 and 0.02). The non-VARI BSI rates were lowest in the arteriovenous graft group. Staphylococci comprised the majority of events, with Staphylococcus aureus implicated in 29%. Gram-negative BSIs were prevalent, particularly in CVC groups, and associated with higher mortality. Multidrug-resistant (MDR) S. aureus and carbapenem resistance were relatively low. MDR Gram-negatives were high compared with the Scottish population.

CONCLUSION

Arteriovenous fistula access is confirmed as having lowest all-source and VARI BSI rates, and arteriovenous graft access the lowest non-VARI BSI rates. Staphylococci remain the prevailing genus; however, the contributions of Gram-negative BSIs, the higher mortality, and proportion of MDR organisms in this group are notable.

Communication from the cerebellum to the neocortex during sleep spindles

Surprisingly little is known about neural activity in the sleeping cerebellum. Using long-term wireless recording, we characterised dynamic cerebro-thalamo-cerebellar interactions during natural sleep in monkeys. Similar sleep cycles were evident in both M1 and cerebellum as cyclical fluctuations in firing rates as well as a reciprocal pattern of slow waves and sleep spindles. Directed connectivity from motor cortex to the cerebellum suggested a neocortical origin of slow waves. Surprisingly however, spindles were associated with a directional influence from the cerebellum to motor cortex, conducted via the thalamus. Furthermore, the relative phase of spindle-band oscillations in the neocortex and cerebellum varied systematically with their changing amplitudes. We used linear dynamical systems analysis to show that this behaviour could only be explained by a system of two coupled oscillators. These observations appear inconsistent with a single spindle generator within the thalamo-cortical system, and suggest instead a cerebellar contribution to neocortical sleep spindles. Since spindles are implicated in the off-line consolidation of procedural learning, we speculate that this may involve communication via cerebello-thalamo-neocortical pathways in sleep.

National Guidelines on the Provision of Outpatient Parenteral Antimicrobial Therapy (OPAT)

Aim Outpatient parenteral antimicrobial therapy (OPAT) is an option in patients who require parenteral antimicrobial administration and are clinically well enough for hospital discharge. This is an update of the Irish National OPAT guidelines which were last reviewed in 2011. Methods The guideline was devised through a collaborative process with the national OPAT Working Group and a review of the literature. It is intended for clinicians who prescribe any intravenous (IV) antimicrobials outside of the inpatient setting in the Republic of Ireland. Results Patient care while on OPAT should be provided by a designated OPAT service, with clear managerial and clinical governance lines of responsibility. It should be conducted using a team approach with a clinical lead on each site either as an infection specialist, or a general medical physician with infection specialist input and an OPAT nurse. An antimicrobial pharmacist is also desirable. Several factors must be considered when assessing patient's suitability for OPAT including exclusion criteria, infection-specific factors, and patient specific factors such as physical, social and logistic criteria. Conclusion This updated guideline advocates a more individualised OPAT approach, with the recognition that specific antimicrobials and/or specific delivery models may be more appropriate for certain patient groups. Full guidelines are available through www.opat.ie.

Patient Safety Event Reporting and Opportunities for Emergency Medicine Resident Education

Introduction

Healthcare systems often expose patients to significant, preventable harm causing an estimated 44,000 to 98,000 deaths or more annually. This has propelled patient safety to the forefront, with reporting systems allowing for the review of local events to determine their root causes. As residents engage in a substantial amount of patient care in academic emergency departments, it is critical to use these safety event reports for resident-focused interventions and educational initiatives. This study analyzes reports from the Virginia Commonwealth University Health System to understand how the reports are categorized and how it relates to opportunities for resident education.

Methods

Identifying categories from the literature, three subject matter experts (attending physician, nursing director, registered nurse) categorized an initial 20 reports to resolve category gaps and then 100 reports to determine inter-rater reliability. Given sufficient agreement, the remaining 400 reports were coded individually for type of event and education among other categories.

Results

After reviewing 513 events, we found that the most common event types were issues related to staff and resident training (25%) and communication (18%), with 31% requiring no education, 46% requiring directed educational feedback to an individual or group, 20% requiring education through monthly safety updates or meetings, 3% requiring urgent communication by email or in-person, and <1% requiring simulation.

Conclusion

Twenty years after the publication of To Err is Human, gains have been made integrating quality assurance and patient safety within medical education and hospital systems, but there remains extensive work to be done. Through a review and analysis of our patient safety event reporting system, we were able to gain a better understanding of the events that are submitted, including the types of events and their severity, and how these relate to the types of educational interventions provided (eg, feedback, simulation). We also determined that these events can help inform resident education and learning using various types of education. Additionally, incorporating residents in the review process, such as through root cause analyses, can provide residents with high-quality, engaging learning opportunities and useful, lifelong skills, which is invaluable to our learners and future physicians.

AB0402 DISEASE ACTIVITY AND OBSESSIVE-COMPULSIVE DISORDER IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Obsessive-compulsive disorder (OCD) is more prevalent in systemic autoimmune diseases when compared to healthy controls. This is in part due to inflammatory mechanisms, common across both conditions. Neuroinflammation and specifically problems within the basal ganglia are associated with OCD.

Objectives:

The primary objective of this analysis was to investigate the effects of disease activity in systemic lupus erythematosus (SLE) on OCD. Other variables investigated included psychiatric aspects, inflammatory biomarkers and structural brain abnormalities.

Methods:

SLE patients who met ACR or SLICC criteria were recruited. Demographic and clinical data were collected and data measuring disease activity (BILAG and SLEDAI-2K), disease damage (SLICC-DI), depression (MADRS, BDI-II, HADS), anxiety (HADS, STAI), fatigue (FSMC), quality of life (LupusQoL and EQ5D), inflammatory and endothelial activation (EA) biomarkers (IL-6, ESR, TNF-α, MCP-1, hsCRP, BLyS, VCAM-1, VEGF, EMVs) and OCD (OCI-R). MRI FLAIR structural scans were also used to examine signal hyperintensities in the brain. Participants with active disease (SLE-F) also had a 2ndvisit approx. 4 months later. Non-parametric correlations with the OCI-R were undertaken for all SLE participants and for the change over time scores for the SLE-F participants (n=11).

Results:

39 participants were included in the analysis and were typical for a SLE population. 6 (23%) patients had scores above the threshold for OCD. OCI-R significantly correlated with disease activity, quality of life, fatigue, depression and anxiety measures for all the SLE participants. Change in monocyte chemoattractant protein-1 (MCP-1) correlated with the OCI-R for the within SLE-F group analysis (Table 1). No significant correlations were found with the full SLE group for inflammatory or EA biomarkers or with either group for the structural brain analysis.

Table 1.

Significant correlations with the OCI-R for: a) all SLE participants; b) the SLE-F group only (visit 1 minus visit 2).

Variablersp-valuea)All SLE participants, n=39Disease activity: BILAG global score0.4080.01Quality of life: LupusQoL – Physical-0.4950.001  – Pain-0.535<0.001  – Planning-0.586<0.001  – Intimate-0.3420.03  – Burden-0.5040.001  – Emotion-0.3970.01  – Fatigue-0.4710.002 EQ5D: VAS-0.4180.01  total-0.3590.03Fatigue measures (FSMC): Cognitive0.5210.001 Motor0.4480.004Depression measures: MADRS0.4670.003 HADS – D0.545<0.001Anxiety measure: HADS-A0.3750.02b)SLE-F group (v1-v2), n=11Inflammatory marker: MCP-10.7710.006

BILAG The British Isles Lupus Assessment Group index, LupusQoL Lupus quality of life, EQ5D European quality of life, VAS visual analogue scale, FSMC Fatigue scale for motor and cognitive function, MADRS Montgomery Asberg depression rating scale, HADS Hospital anxiety and depression scale, D-depression, A-anxiety score, MCP-1 monocyte chemoattractant protein-1

Conclusion:

OCD in lupus is strongly related to other psychological co-morbidities, fatigue and quality of life. Our results also support a role for inflammatory pathways in mediating some of these changes and so obsessive-compulsive features should be assessed in SLE patients who flare. A larger study is underway to better understand the mechanisms underlying these associations.

Acknowledgments:

This study was partially funded by an unrestricted grant from Sanofi Genzyme and supported by the NIHR Manchester Biomedical Research Centre.

Disclosure of Interests: :

Michelle Barraclough Grant/research support from: This study was partially funded by an unrestricted grant from Sanofi Genzyme., Ben Parker Grant/research support from: GSK and Sanofi Genzyme, Consultant of: GSK, AstraZenaca, UCV, Abbvie, Pfizer, BMS, Celltrion, Shane McKie: None declared, Philip Pemberton: None declared, Alan Jackson: None declared, Rebecca Elliott: None declared, Ian N. Bruce Grant/research support from: Genzyme Sanofi, GSK, and UCB, Consultant of: Eli Lilly, AstraZeneca, UCB, Iltoo, and Merck Serono, Speakers bureau: UCB

A trio of simple optimized axisymmetric kinematic dynamos in a sphere

Planetary magnetic fields are generated by the motion of conductive fluid in the planet's interior. Complex flows are not required for dynamo action; simple flows have been shown to act as efficient kinematic dynamos, whose physical characteristics are more straightforward to study. Recently, Chen et al. (2018, J. Fluid Mech. 839, 1-32. (doi:10.1017/jfm.2017.924)) found the optimal, unconstrained kinematic dynamo in a sphere, which, despite being of theoretical importance, is of limited practical use. We extend their work by restricting the optimization to three simple two-mode axisymmetric flows based on the kinematic dynamos of Dudley & James (1989, Proc. R. Soc. Lond. A 425, 407-429. (doi:10.1098/rspa.1989.0112)). Using a Lagrangian optimization, we find the smallest critical magnetic Reynolds number for each flow type, measured using an enstrophy-based norm. A Galerkin method is used, in which the spectral coefficients of the fluid flow and magnetic field are updated in order to maximize the final magnetic energy. We consider the t ⁰ ₁ s ⁰ ₁, t ⁰ ₁ s ⁰ ₂ and t ⁰ ₂ s ⁰ ₂ flows and find enstrophy-based critical magnetic Reynolds numbers of 107.7, 142.4 and 125.5 (13.7, 19.6 and 16.4, respectively, with the energy-based definition). These are up to four times smaller than the original flows. These simple and efficient flows may be used as benchmarks in future studies.