Prediction of m6A and m5C at single-molecule resolution reveals a transcriptome-wide co-occurrence of RNA modifications

The epitranscriptome embodies many new and largely unexplored functions of RNA. A significant roadblock hindering progress in epitranscriptomics is the identification of more than one modification in individual transcript molecules. We address this with CHEUI (CH3 (methylation) Estimation Using Ionic current). CHEUI predicts N6-methyladenosine (m6A) and 5-methylcytosine (m5C) in individual molecules from the same sample, the stoichiometry at transcript reference sites, and differential methylation between any two conditions. CHEUI processes observed and expected nanopore direct RNA sequencing signals to achieve high single-molecule, transcript-site, and stoichiometry accuracies in multiple tests using synthetic RNA standards and cell line data. CHEUI's capability to identify two modification types in the same sample reveals a co-occurrence of m6A and m5C in individual mRNAs in cell line and tissue transcriptomes. CHEUI provides new avenues to discover and study the function of the epitranscriptome.

Stomatal conductance reduction tradeoffs in maize leaves: A theoretical study

As the leading global grain crop, maize significantly impacts agricultural water usage. Presently, photosynthesis (A net ${A}_{\text{net}}$ ) in leaves of modern maize crops is saturated withCO 2 ${\text{CO}}_{2}$ , implying that reducing stomatal conductance (g s ${g}_{{\rm{s}}}$ ) would not affectA net ${A}_{\text{net}}$ but reduce transpiration (τ $\tau $ ), thereby increasing water use efficiency (WUE). Whileg s ${g}_{{\rm{s}}}$ reduction benefits upper canopy leaves under optimal conditions, the tradeoffs in low light and nitrogen-deficient leaves under nonoptimal microenvironments remain unexplored. Moreover,g s ${g}_{{\rm{s}}}$ reduction increases leaf temperature (T leaf ${T}_{\text{leaf}}$ ) and water vapor pressure deficit, partially counteracting transpiratory water savings. Therefore, the overall impact ofg s ${g}_{{\rm{s}}}$ reduction on water savings remains unclear. Here, we use a process-based leaf model to investigate the benefits of reducedg s ${g}_{{\rm{s}}}$ in maize leaves under different microenvironments. Our findings show that increases inT leaf ${T}_{\text{leaf}}$ due tog s ${g}_{{\rm{s}}}$ reduction can diminish WUE gains by up to 20%. However,g s ${g}_{{\rm{s}}}$ reduction still results in beneficial WUE tradeoffs, where a 29% decrease ing s ${g}_{{\rm{s}}}$ in upper canopy leaves results in a 28% WUE gain without loss inA net ${A}_{\text{net}}$ . Lower canopy leaves exhibit superior tradeoffs ing s ${g}_{{\rm{s}}}$ reduction with 178% gains in WUE without loss inA net ${A}_{\text{net}}$ . Our simulations show that these WUE benefits are resilient to climate change.

Development of ISB 1442, a CD38 and CD47 bispecific biparatopic antibody innate cell modulator for the treatment of multiple myeloma

Antibody engineering can tailor the design and activities of therapeutic antibodies for better efficiency or other advantageous clinical properties. Here we report the development of ISB 1442, a fully human bispecific antibody designed to re-establish synthetic immunity in CD38+ hematological malignancies. ISB 1442 consists of two anti-CD38 arms targeting two distinct epitopes that preferentially drive binding to tumor cells and enable avidity-induced blocking of proximal CD47 receptors on the same cell while preventing on-target off-tumor binding on healthy cells. The Fc portion of ISB 1442 is engineered to enhance complement dependent cytotoxicity, antibody dependent cell cytotoxicity and antibody dependent cell phagocytosis. ISB 1442 thus represents a CD47-BsAb combining biparatopic targeting of a tumor associated antigen with engineered enhancement of antibody effector function to overcome potential resistance mechanisms that hamper treatment of myeloma with monospecific anti-CD38 antibodies. ISB 1442 is currently in a Phase I clinical trial in relapsed refractory multiple myeloma.

Proteomic-miRNA Biomics Profile Reveals 2D Cultures of Human iPSC-Derived Neural Progenitor Cells More Sensitive than 3D Spheroid System Against the Experimental Exposure to Arsenic

The iPSC-derived 3D models are considered to be a connective link between 2D culture and in vivo studies. However, the sensitivity of such 3D models is yet to be established. We assessed the sensitivity of the hiPSC-derived 3D spheroids against 2D cultures of neural progenitor cells. The sub-toxic dose of Sodium Arsenite (SA) was used to investigate the alterations in miRNA-proteins in both systems. Though SA exposure induced significant alterations in the proteins in both 2D and 3D systems, these proteins were uncommon except for 20 proteins. The number and magnitude of altered proteins were higher in the 2D system compared to 3D. The association of dysregulated miRNAs with the target proteins showed their involvement primarily in mitochondrial bioenergetics, oxidative and ER stress, transcription and translation mechanism, cytostructure, etc., in both culture systems. Further, the impact of dysregulated miRNAs and associated proteins on these functions and ultrastructural changes was compared in both culture systems. The ultrastructural studies revealed a similar pattern of mitochondrial damage, while the cellular bioenergetics studies confirm a significantly higher energy failure in the 2D system than to 3D. Such a higher magnitude of changes could be correlated with a higher amount of internalization of SA in 2D cultures than in 3D spheroids. Our findings demonstrate that a 2D culture system seems better responsive than a 3D spheroid system against SA exposure.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

Boehringer Ingelheim and Eli Lilly.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

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

The SPEAK study rationale and design: A linguistic corpus-based approach to understanding thought disorder

AIM

Psychotic symptoms are typically measured using clinical ratings, but more objective and sensitive metrics are needed. Hence, we will assess thought disorder using the Research Domain Criteria (RDoC) heuristic for language production, and its recommended paradigm of "linguistic corpus-based analyses of language output". Positive thought disorder (e.g., tangentiality and derailment) can be assessed using word-embedding approaches that assess semantic coherence, whereas negative thought disorder (e.g., concreteness, poverty of speech) can be assessed using part-of-speech (POS) tagging to assess syntactic complexity. We aim to establish convergent validity of automated linguistic metrics with clinical ratings, assess normative demographic variance, determine cognitive and functional correlates, and replicate their predictive power for psychosis transition among at-risk youths.

METHODS

This study will assess language production in 450 English-speaking individuals in Australia and Canada, who have recent onset psychosis, are at clinical high risk (CHR) for psychosis, or who are healthy volunteers, all well-characterized for cognition, function and symptoms. Speech will be elicited using open-ended interviews. Audio files will be transcribed and preprocessed for automated natural language processing (NLP) analyses of coherence and complexity. Data analyses include canonical correlation, multivariate linear regression with regularization, and machine-learning classification of group status and psychosis outcome.

CONCLUSIONS

This prospective study aims to characterize language disturbance across stages of psychosis using computational approaches, including psychometric properties, normative variance and clinical correlates, important for biomarker development. SPEAK will create a large archive of language data available to other investigators, a rich resource for the field.

A65 VISCERAL FAT INDICES: DO THEY HELP DIFFERENTIATE CROHN’S DISEASE AND INTESTINAL TUBERCULOSIS IN CHILDREN?

Background

Crohn’s disease (CD) and Intestinal tuberculosis (ITB) mimic each other and are often difficult to differentiate. A correct and prompt diagnosis is essential for a good outcome. Mesenteric fat hypertrophy is a feature of CD and studies in adults have shown higher visceral fat in CD than ITB. There is no published data in children.

Purpose

This study evaluated the utility of visceral fat indices in differentiating CD and ITB in children.

Method

Symptomatic children diagnosed to have CD or ITB based on standard recommended criteria were enrolled. The clinical and laboratory details were noted. Abdominal fat was measured on Computed Tomography in supine position at the level of L4 vertebrae. Visceral fat (VF) and subcutaneous fat (SF) area was measured separately by an experienced radiologist, blinded to the diagnosis. Sum of VF and SF was taken as total fat (TF). VF/SF and VF/TF ratio was calculated.

Result(s)

34 children [14 boys, median age 14.0 (inter quartile range 10.8-17.0)] years were recruited, of which 12 (29%) had CD [7 boys, age 13.0 (IQR 9.25-16.5) years] and 22 (71%) had ITB [7 boys, age-14.5 (IQR 11-17) years]. Visceral fat area (VF) was significantly higher in CD compared to ITB (table 1). However, there was no significant difference in the SF (2199.5 (1537.6-3881.6) vs 2176.5 (671.0-6651.5) mm²; p=0.958) and TF (3096.1 (2108.2-5373.5) vs 4518.2 (2677.6-8456.3) mm²; p=0.245) in ITB and CD respectively. The ratio of VF/SF and VF/TF was significantly higher in CD as compared to ITB for all cases (table1). When comparing CD and ITB in boys and girls separately the same trend was observed but the difference was statistically significant only for boys. On ROC analysis, VF:SF ratio of 0.609 predicted CD with the sensitivity of 75% and specificity of 86.4% (area under curve [AUC]-0.795, 95% CI 0.636-0.955; p=0.005). VF:TF ratio of 0.379 had similar sensitivity of 75% and specificity of 86.4% (AUC-0.795, 95% CI 0.636-0.955; p=0.005). The VF area of 1485.26 mm² had a sensitivity of 83.3% and specificity of 72.7% for CD (AUC-0.758, 95% CI 0.590-0.925; p=0.01).

Image

Conclusion(s)

The VF/SF ratio is a simple, non-invasive, objective parameter to differentiate CD and ITB in children with a good sensitivity and specificity.

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Disclosure of Interest

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Harmonizing Definitions for Diagnostic Criteria and Prognostic Assessment of Transplantation-Associated Thrombotic Microangiopathy: A Report on Behalf of the European Society for Blood and Marrow Transplantation, American Society for Transplantation and Cellular Therapy, Asia-Pacific Blood and Marrow Transplantation Group, and Center for International Blood and Marrow Transplant Research

Transplantation-associated thrombotic microangiopathy (TA-TMA) is an increasingly recognized complication of hematopoietic cell transplantation (HCT) associated with significant morbidity and mortality. However, TA-TMA is a clinical diagnosis, and multiple criteria have been proposed without universal application. Although some patients have a self-resolving disease, others progress to multiorgan failure and/or death. Poor prognostic features also are not uniformly accepted. The lack of harmonization of diagnostic and prognostic markers has precluded multi-institutional studies to better understand incidence and outcomes. Even current interventional trials use different criteria, making it challenging to interpret the data. To address this urgent need, the American Society for Transplantation and Cellular Therapy, Center for International Bone Marrow Transplant Research, Asia-Pacific Blood and Marrow Transplantation, and European Society for Blood and Marrow Transplantation nominated representatives for an expert panel tasked with reaching consensus on diagnostic and prognostic criteria. The panel reviewed literature, generated consensus statements regarding diagnostic and prognostic features of TA-TMA using the Delphi method, and identified future directions of investigation. Consensus was reached on 4 key concepts: (1) TA-TMA can be diagnosed using clinical and laboratory criteria or tissue biopsy of kidney or gastrointestinal tissue; however, biopsy is not required; (2) consensus diagnostic criteria are proposed using the modified Jodele criteria with additional definitions of anemia and thrombocytopenia. TA-TMA is diagnosed when ≥4 of the following 7 features occur twice within 14 days: anemia, defined as failure to achieve transfusion independence despite neutrophil engraftment; hemoglobin decline by ≥1 g/dL or new-onset transfusion dependence; thrombocytopenia, defined as failure to achieve platelet engraftment, higher-than-expected transfusion needs, refractory to platelet transfusions, or ≥50% reduction in baseline platelet count after full platelet engraftment; lactate dehydrogenase (LDH) exceeding the upper limit of normal (ULN); schistocytes; hypertension; soluble C5b-9 (sC5b-9) exceeding the ULN; and proteinuria (≥1 mg/mg random urine protein-to-creatinine ratio [rUPCR]); (3) patients with any of the following features are at increased risk of nonrelapse mortality and should be stratified as high-risk TA-TMA: elevated sC5b-9, LDH ≥2 times the ULN, rUPCR ≥1 mg/mg, multiorgan dysfunction, concurrent grade II-IV acute graft-versus-host disease (GVHD), or infection (bacterial or viral); and (4) all allogeneic and pediatric autologous HCT recipients with neuroblastoma should be screened weekly for TA-TMA during the first 100 days post-HCT. Patients diagnosed with TA-TMA should be risk-stratified, and those with high-risk disease should be offered participation in a clinical trial for TA-TMA-directed therapy if available. We propose that these criteria and risk stratification features be used in data registries, prospective studies, and clinical practice across international settings. This harmonization will facilitate the investigation of TA-TMA across populations diverse in race, ethnicity, age, disease indications, and transplantation characteristics. As these criteria are widely used, we expect continued refinement as necessary. Efforts to identify more specific diagnostic and prognostic biomarkers are a top priority of the field. Finally, an investigation of the impact of TA-TMA-directed treatment, particularly in the setting of concurrent highly morbid complications, such as steroid-refractory GVHD and infection, is critically needed.

Proteome architecture of human-induced pluripotent stem cell-derived three-dimensional organoids as a tool for early diagnosis of neuronal disorders

BACKGROUND AND OBJECTIVES

Induced pluripotent stem cells (iPSCs) derived three-dimensional (3D) model for rare neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) is emerging as a novel alternative to human diseased tissue to explore the disease etiology and potential drug discovery. In the interest of the same, we have generated a TDP-43-mutated human iPSCs (hiPSCs) derived 3D organoid model of ALS disease. The high-resolution mass spectrometry (MS)-based proteomic approach is used to explore the differential mechanism under disease conditions and the suitability of a 3D model to study the disease.

MATERIALS AND METHODS

The hiPSCs cell line was procured from a commercial source, grown, and characterized following standard protocols. The mutation in hiPSCs was accomplished using CRISPR/Cas-9 technology and predesigned gRNA. The two groups of organoids were produced by normal and mutated hiPSCs and subjected to the whole proteomic profiling by high-resolution MS in two biological replicates with three technical replicas of each.

RESULTS

The proteomic analysis of normal and mutated organoids revealed the proteins associated with pathways of neurodegenerative disorders, proteasomes, autophagy, and hypoxia-inducible factor-1 signaling. Differential proteomic analysis revealed that the mutation in TDP-43 gene caused proteomic deregulation, which impaired protein quality mechanisms. Furthermore, this impairment may contribute to the generation of stress conditions that may ultimately lead to the development of ALS pathology.

CONCLUSION

The developed 3D model represents the majority of candidate proteins and associated biological mechanisms altered in ALS disease. The study also offers novel protein targets that may uncloud the precise disease pathological mechanism and be considered for future diagnostic and therapeutic purposes for various neurodegenerative disorders.

Risk of stroke in patients with type 2 diabetes receiving semaglutide or a dipeptidyl peptidase-4 inhibitor: a real-world US claims database analysis

Introduction

People with type 2 diabetes (T2D) have a higher risk of stroke than those without, are likely to experience stroke at a younger age, and have worse outcomes. The cardiovascular benefits of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in T2D have been demonstrated in randomized controlled trials. A meta-analysis of these data has shown that GLP-1 RAs are associated with a significant reduction in the risk of stroke; however, there remains an evidence gap for the real-world effect of semaglutide specifically on stroke risk.

Purpose

To compare real-world risk of stroke in patients with T2D or T2D + atherosclerotic cardiovascular disease (ASCVD) initiating either semaglutide or a dipeptidyl peptidase-4 inhibitor (DPP-4i).

Methods

For inclusion, adults (≥18 years) in a US claims database required a claim indicating initiation of either semaglutide or a DPP-4i (index date) during the index period (1/1/18–30/9/20), a diagnosis code for T2D on or before the index date, and 12 months' continuous enrolment pre-index. Exclusion criteria were a claim for semaglutide, DPP-4i or injectable glucose-lowering medication, or diagnosis code for type 1 or secondary diabetes in the 12 months pre-index; or a claim associated with pregnancy or gestational diabetes any time during the study period. Patients were propensity score matched 1:1 on 27 baseline demographic and clinical characteristics. Patients who also had a diagnosis code for ASCVD pre-index were matched separately on 26 variables. Primary outcome was time to first stroke event during follow-up, defined as a medical claim with stroke as primary diagnosis during inpatient or emergency room visit. Patients with no event were censored at end of enrolment or end of study period (30/9/20), whichever was earliest.

Results

Post-matching, there were 17,920 pairs with T2D and 4234 pairs with T2D+ASCVD. The groups were well matched on baseline characteristics (Table). For T2D, patients initiating semaglutide had a lower risk of stroke than those initiating a DPP-4i (hazard ratio [HR], 0.63; 95% confidence interval [CI]: 0.41–0.95; p=0.029). This trend was more pronounced for T2D+ASCVD (HR, 0.45 [0.24–0.86]; p=0.015). Overall, 34 patients with T2D receiving semaglutide (0.2%) experienced a stroke event (incidence rate [IR] per 100 person-years, 0.25), compared with 60 patients receiving a DPP-4i (0.3%; IR, 0.40; IR ratio [IRR], 0.62; 95% CI: 0.40–0.95). For the groups with T2D+ASCVD, 13 patients receiving semaglutide (0.3%; IR, 0.40) and 32 receiving a DPP-4i (0.8%; IR, 0.90) experienced a stroke event (IRR, 0.44 [0.23–0.85]). The Figure shows cumulative incidence of stroke over follow-up (median 237–258 days).

Conclusion

This analysis provides initial insights into the potential of semaglutide to reduce real-world stroke risk in patients with T2D. Analyses with additional comparison groups and longer follow-up are needed to determine the broader clinical and economic implications.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This study was funded by Novo Nordisk A/S. Medical writing support was provided by Oxford PharmaGenesis, Oxford, UK with funding from Novo Nordisk A/S.

Early versus late acute graft pyelonephritis: A retrospective analysis of graft and patient outcomes

BACKGROUND

Acute graft pyelonephritis (AGPN) is thought to affect graft and patient survival among renal transplant recipients. The objective was to compare outcomes among early AGPN (<6 months from transplant) versus late AGPN (>6 months from transplant).

METHODS

This retrospective study analysed 150 patients with AGPN dividing them into early and late AGPN from 2008 to 2016. Predictors of graft loss and mortality were compared using logistic regression analysis. Graft survival and patient survival were analysed using Kaplan-Meyer survival plots.

RESULTS

55.3% (n = 83) had early AGPN and 44.7% (n = 67) had late AGPN. In an early AGPN group, 13.3% had CMV disease on the follow-up, compared to only 3% in the late AGPN group (p > 0.05). Furthermore, 38.6% had prolonged DJ stent in-situ (> 2 weeks) following transplant surgery in the early AGPN compared to only 19.4% in the late AGPN group (p < 0.05). Recurrent GPN was more common in the late AGPN group - (35.8% versus 18.1%). The presence of renal abscess was predictive of graft loss in Univariate analysis (HR-6.12, p < 0.004). There was decreased death-censored graft survival in the early AGPN group (p = 0.035), without a significant difference in the patient survival among the two groups.

CONCLUSION

The occurrence of early AGPN had a significant impact on long-term graft survival in renal transplant recipients, with no significant effect on patient survival. This study underlines the paramount importance of the prevention of urinary tract infection (UTI) in renal transplant recipients.

Gastric bypass surgery contributing to hyperammonaemic encephalopathy: an under-reported cause of severe nutritional deficiency and significant patient mortality

Gastric-bypass associated hyperammonaemia (GaBHA) is an under-recognised cause of non-hepatic encephalopathy that is associated with significant mortality and has limited reporting in published literature. GaBHA has been reported predominately in middle-aged females with a past surgical history of Roux-En-Y surgical procedure. Individuals may present at any stage post-surgery and an important minority may have an undiagnosed inherited metabolic disorder. We report a case of a 49 year old woman who presented acutely with encephalopathy, a significantly elevated plasma ammonia level, and substantial multifactorial nutritional deficiency which required correction with intensive enteral and parenteral nutritional support. This case represented a diagnostic and management challenge for acute medical physicians and the multidisciplinary team involved.

Regulation of STAT3 signaling in IFNγ and IL10 pathways and in their cross-talk

The pro-inflammatory IFNγ-STAT1 pathway and anti-inflammatory IL10-STAT3 pathway elicit cellular responses primarily utilizing their canonical STATs. However IL10 mediated STAT1 and IFNγ mediated STAT3 activation is also observed, suggesting crosstalk of these functionally opposing signaling pathways can potentially reshape the canonical dynamics both STATs and alter the expression of their target genes. Herein, we measured the dynamics of STATs in response to different doses of IL10 or IFNγ and in their co-stimulation and employed quantitative modeling to understand the regulatory mechanisms controlling signal responses in individual and co-simulation scenarios. Our experiments show, STAT3 in particular, exhibits a bell-shaped dose-response while treated with IFNγ or IL10 and our model quantiatively captured the dose-dependent dynamics of both the STATs in both pathways. The model next predicted and subsequent experiments validated that STAT3 dynamics would robustly remain IL10 specific when subjected to a co-stimulation of both IFNγ and IL10. Genes common to both pathways also exhibited IL10 specific expression during the co-stimulation. The findings thus uncover anovel feature of the IL10-STAT3 signaling axis during pathway crosstalk. Finally, parameter sampling coupled to information theory based analysis showed that bell-shaped signal-response of STAT3 in both pathways is primarily dependent on receptor concentration whereas robustness of IL10-STAT3 signaling axis in co-stimulation results from the negative regulation of the IFNγ pathway.

Data-driven operation of the resilient electric grid: A case of COVID-19

Electrical energy is a vital part of modern life, and expectations for grid resilience to allow a continuous and reliable energy supply has tremendously increased even during adverse events (e.g. Ukraine cyberattack, Hurricane Maria). The global pandemic COVID-19 has raised the electric energy reliability risk due to potential workforce disruptions, supply chain interruptions, and increased possible cybersecurity threats. Additionally, the pandemic introduces a significant degree of uncertainty to the grid operation in the presence of other challenges including aging power grids, high proliferation of distributed generation, market mechanism, and active distribution network. This situation increases the need for measures for the resiliency of power grids to mitigate the impact of the pandemic as well as simultaneous extreme events including cyberattacks and adverse weather events. Solutions to manage such an adverse scenario will be multi-fold: (a) emergency planning and organisational support, (b) following safety protocol, (c) utilising enhanced automation and sensing for situational awareness, and (d) integration of advanced technologies and data points for ML-driven enhanced decision support. Enhanced digitalisation and automation resulted in better network visibility at various levels, including generation, transmission, and distribution. These data or information can be employed to take advantage of advanced machine learning techniques for automation and increased power grid resilience. In this paper, the resilience of power grids in the face of pandemics is explored and various machine learning tools that can be helpful to augment human operators are discused by: (a) reviewing the impact of COVID-19 on power grid operations and actions taken by operators/organisations to minimise the impact of COVID-19, and (b) presenting recently developed tools and concepts of machine learning and artificial intelligence that can be applied to increase the resiliency of power systems in normal and extreme scenarios such as the COVID-19 pandemic.

318 Adapting Surgical Intercalation Teaching to The Pandemic – A Novel Near-Peer Educational Model for Intercalating Medical Students

Aim

The COVID-19 pandemic has reduced medical student exposure to traditional formats of surgical teaching, thereby irrefutably altering surgical education for the foreseeable future. The pandemic has compounded the preliminarily reported disconnect intercalating students experience, as well as depriving students of opportunities for surgical exposure. The aim of our study is to devise an innovative near-peer system to supplement surgical teaching and guidance for the ‘Surgical Sciences’ Intercalated BSc offered at University College London, hence promoting surgical education.

Method

Past students (preceding two cohorts) were competitively recruited, termed mentors. Each student was paired with a mentor for one-to-one guidance. Mentors and programme directors formulated surgical, module-specific, virtual tutorials (Zoom). Mentees were surveyed using predesigned Google Forms to gauge subjective utility. Likert Scales (0-10) were used for quantitative analysis and free-text fields for further commentary.

Results

Mentors and programme directors devised 8 module-specific, surgical tutorials over term 1, spaced on average at every 1.5 weeks. A statistically significant increase in confidence reported per taught module, from 5.85±1.16 to 7.85±0.93 (P &lt; 0.0001), was observed. Mentees report an overall recommendation of 93.19% that all tutorials be rerun for the upcoming cohort. 75% of mentees predict their designated mentors will be ‘very useful’ in their surgical education.

Conclusions

A novel model of near-peer education for surgical intercalation studies has been successfully established, whereby students receive valuable education and guidance from mentors with relevant surgical experiences. Students report significant utility in this programme, which can be a constant in otherwise turbulent times for surgical education.

980 Technological Innovations in The Management of Pressure Ulcers: A Systematic Review and Discussion

Aim

Pressure ulcers (PUs) affect over 700,000 patients per annum and are associated with an up to fourfold increase in mortality rate in older populations with complex pathologies. NICE guidelines for PU management involve a combination of low-grade technological interventions, including dressings and foam mattresses, while technology-centric therapies are not offered. The aim of this systematic review is to evaluate the effectiveness of any novel and high-grade technological PU interventions.

Method

The PubMed, Embase (via Ovid), Web of Science and CINAHL databases were electronically searched using free-text and MeSH search strings. Results evaluating the type of technological intervention, outcome measures and wound healing rates, duration of hospital stay, requirement for surgical debridement, infection and mortality rates were methodically assessed.

Results

An initial search identified 900 articles. Using the PRISMA guidance, 25 studies were included, encompassing 845 patients. 28 novel modalities of high-grade innovations were identified, with distinguished technologies including smart wireless bandages and 3D-printed wound repair scaffolds. Overall, 92.8% of devices demonstrated an improvement in wound healing (P &lt; 0.05). A novel framework was created from the different innovations identified to approach adopting innovation in PU management.

Conclusions

The majority of high-technology innovations identified in this systematic review significantly improve PU healing, thus offering an additional pathway to standard care. Given the annual cost of PUs (£531 million), it is vital innovative technologies are considered as the NHS transitions into a digital age. Therefore, further studies are essential and recommended to evaluate the potential benefit of the promising, innovative technologies identified.

851 Giant Oncocytoma In A Solitary Kidney: A Case Report on Balancing Surgical Resection Against Surveillance

Renal oncocytomas are benign kidney neoplasms that are typically small, unilaterally localised (95%) and challenging to differentiate on cross-sectional imaging, hence requiring surgical intervention. We herein present the extremely rare case of a patient with giant, bilateral oncocytomas and oncocytosis, and chronic kidney disease (CKD) and discuss the associated treatment challenges.

A 61-year-old male with no past medical history presented with CKD (eGFR of 32ml/min). On investigation, cross sectional imaging revealed bilateral, multifocal, solid and vascular renal lesions. The largest lesion measuring 115mm x 102mm was situated in the right kidney, with multiple lesions noted in the left kidney, measuring up to 44mm. He subsequently underwent a right radical nephrectomy and histopathological analysis reported oncocytosis of the background kidney. The largest left sided renal lesion was biopsied, also confirmatory of benign oncocytoma. eGFR after surgery was 26ml/min. Following patient-centric consultations, further surgical intervention for the left sided renal lesions was declined, aiming to avoid renal replacement therapy (RRT). He has remained on active surveillance with biannual scans for 6 years. The lesions in his remaining kidney have since grown and coalesced into a single large lesion, with axial dimensions in the most recent MRI scan of 104mm x 306mm. He has progressed to stage IV CKD (eGFR 16ml/min), but still currently without need of RRT.

This case study underscores both the significance of shared decision making in urology and surgery. Ultimately, the most significant skill lies in knowing when to not operate, especially when presented with the rarest of cases.

119 The Potential of Low-fidelity Arthroscopic Simulation Training in Trauma and Orthopaedic Surgery: A Systematic Review of Experimental Studies

Aim

In an era of budget tightening and work-hour guideline reductions that have significantly reduced surgical exposure, low-fidelity arthroscopic simulators have an essential role to play in surgical training. The COVID-19 pandemic has only further amplified the need for alternative training models, as 91% of orthopaedic trainees have had elective procedures cancelled. The purpose of this systematic review is to synopsise the limited literature regarding the effectiveness of low-fidelity training models in the instruction of novices, and to formulate recommendations for future studies.

Method

The Embase, PubMed, Web of Science and Scopus databases were electronically searched. Studies from any year that described the use of orthopaedic, low-fidelity arthroscopic training models in novice populations were included. Questionnaires, case studies and review studies were excluded. Risk of bias assessments were also conducted for all studies.

Results

16 studies were identified. Using the PRISMA algorithm, 6 studies were deemed relevant. A cross-study comparison revealed low-fidelity arthroscopic simulators reduced time to completion outcomes (P &lt; 0.05), increased ASSET scores (P &lt; 0.01) and confirmed face validity and transfer of skills (cadaver, live patients).

Conclusions

Low-fidelity simulator training significantly improves the arthroscopic performance of novices, without the high setup costs and practical constraints of high-fidelity equivalents. Low-fidelity arthroscopic simulators remain a promising training apparatus in an era of reduced surgical exposure (COVID-19). We have identified the need for consistent outcome measures with greater sample sizes across future studies. We recommend the use of standardised pre-intervention teaching (e.g., ABOS curriculum) and further transference, construct, and face validity evaluations to support future result interpretations.

1376 Latex Allergies: Seeking an Alternative to Minimise Risk in The Operating Theatre

Introduction

Natural Rubber Latex (NRL) gloves have been ubiquitously used in surgical practice. Over the past few decades, there have been many reports of NRL allergies associated with their use presenting a safety hazard to both patients and healthcare workers. Powder-free and latex-free gloves have been shown to offer reductions in incidence of allergic reactions, as well as cost savings.

Method

We performed a literature search to identify the rates of reaction to latex across the population in addition to the associated costs including litigation costs, costs of admission, and lost work time associated. We further looked at the rates of perforation of alternatives and the costs associated with such a transition.

Results

The UK prevalence of sensitisation amongst healthcare workers has been estimated to be 10%. The average cost of litigation to the employer was found to be $21,402 per claim. The mean cost of inpatient care for anaphylaxis has been cited as £469.88, with additional costs such as follow-up representing approximately £400. A 14-month study found cost savings of $10,000pa with a switch to non-latex gloves. Furthermore, an overall perforation rate of 80% in a latex-free glove compared to 34.4% in a latex glove.

Conclusions

From a business perspective, there is evidence of cost-savings arising from a switch to latex-free gloves, however, formal cost-effectiveness analyses would inform future decisions. Furthermore, comfort and reducing the chances of allergic reactions through removing the offending allergen all represent benefits of switching to latex-free gloves, however, non-inferiority analyses will inform future strategies both locally and nationally.

1070 A Systematic Review of Seymour Fracture Management

Aim

Seymour fractures are distal phalanx fractures of the finger in children with a juxta-epiphyseal or Salter-Harris Type I/II pattern associated with a nail-bed injury. There remains a paucity in literature regarding the development of complications between Seymour fracture management options, with early studies encouraging non-operative management due to the increased rates of post-operative infection. This systematic review aims to identify present-day, optimal management strategies for Seymour fractures, with further analysis of infection rates and secondary outcomes during post-operative recovery.

Method

Free-text search, MeSH terms and expanded keywords/phrases were employed to search the PubMed, Embase (via Ovid), Web of Science and CINAHL databases. Studies that described the management of Seymour fractures in paediatric patients were included, subject to inclusion/exclusion criteria. The data extracted included the sample size, intervention, infection rates and secondary outcomes.

Results

An initial search identified 305 articles, following the PRISMA guidance, 8 studies were eligible for full-text analysis. Across all studies, 307 Seymour fractures were identified (mean age, 10±1.2 years). A cross-study analysis showed a lower rate of adverse outcomes (including malunion/non-union and unplanned operative intervention) for K-wire fixation when compared to external splinting, 8.3% and 20.7% (P ≤ 0.001), respectively.

Conclusions

There was no statistically significant difference between non-operative and operative management in rates of infection and adverse outcomes. However, further analysis revealed a significantly lower risk of complications in patients who received K-wire fixation when compared to external splinting. Nonetheless, further studies with greater levels of evidence need to be carried out to consolidate this.

A pre-registered short-term forecasting study of COVID-19 in Germany and Poland during the second wave

Disease modelling has had considerable policy impact during the ongoing COVID-19 pandemic, and it is increasingly acknowledged that combining multiple models can improve the reliability of outputs. Here we report insights from ten weeks of collaborative short-term forecasting of COVID-19 in Germany and Poland (12 October-19 December 2020). The study period covers the onset of the second wave in both countries, with tightening non-pharmaceutical interventions (NPIs) and subsequently a decay (Poland) or plateau and renewed increase (Germany) in reported cases. Thirteen independent teams provided probabilistic real-time forecasts of COVID-19 cases and deaths. These were reported for lead times of one to four weeks, with evaluation focused on one- and two-week horizons, which are less affected by changing NPIs. Heterogeneity between forecasts was considerable both in terms of point predictions and forecast spread. Ensemble forecasts showed good relative performance, in particular in terms of coverage, but did not clearly dominate single-model predictions. The study was preregistered and will be followed up in future phases of the pandemic.

Limited utility of plasma elafin as a biomarker for skin graft-versus-host disease following allogeneic stem cell transplantation

BACKGROUND

Acute cutaneous graft-versus-host disease (acGVHD) following haematopoietic stem cell transplant (HSCT) is common but difficult to distinguish from other causes of rash. Plasma elafin has been proposed as a diagnostic and prognostic biomarker of skin GVHD.

AIM

To evaluate the role of plasma elafin as a biomarker in acGVHD in an Indian population.

METHODS

Plasma elafin was evaluated in a prospective study of HSCT recipients, conducted over 2 years, taking measurements at baseline and at onset of skin rash after HSCT. Patients were categorized into those with GVHD rash, those with non-GVHD rash and those with no rash and the three groups were compared.

RESULTS

Two hundred and sixty-one patients with a median age of 16 years (range 1-61 years) and a male predominance (175 : 86 M/F) underwent HSCT during the study period: 56 patients in the GVHD group, 49 in the non-GVHD group and 156 in the no-rash group. The median baseline elafin was similar in all three groups. At the onset of rash, median elafin level was similar between GVHD and non-GVHD rash (34 549 vs. 32 077 pg/mL; P = 0.58) and between GVHD and no rash (34 549 vs. 26 197 pg/mL; P = 0.08). A rise in elafin from baseline was significantly different between GVHD and no rash (P < 0.001) but not between GVHD and non-GVHD rash (P = 0.44).

CONCLUSION

The utility of plasma elafin as a biomarker of skin GVHD is very limited. Plasma elafin, although elevated in cutaneous GVHD, is not helpful in distinguishing between GVHD rash and other causes of rash following HSCT.

Synthesis, spectral and sol-gel behavior of mixed ligand complexes of titanium(IV) with oxygen, nitrogen and sulfur donor ligands

A new route to synthesize nano-sized Ti(IV) mixed ligand complexes have been investigated by the reaction of titanium(IV) chloride with ammonium salts of dithiophosphate and 3(2'-hydroxyphenyl)-5-(4-substituted phenyl) pyrazolines. The resultant complex is then treated with H2S gas to get sulfur bridged dimer of Ti(IV) complex, a precursor of TiS2. The morphology of the complexes was studied by employing XRD which shows that all the complexes are amorphous solid. Molecular weight measurements, elemental analysis in conjugation with spectroscopic (IR, 1H NMR, 13C NMR and 31P NMR) studies revealed the dimeric nature of the complexes in which pyrazoline and dithiophosphate are bidentate. Scanning electron microscopic image and XRD indicate that the particles are in the nano range (50 nm). Putting all the facts together, coordination number six is proposed for titanium with octahedral geometry.                     KEY WORDS: Titanium(IV), Dithiophosphate, Pyrazoline, Nano-sized, Sol-gel, Mixed ligand complexes   Bull. Chem. Soc. Ethiop. 2021, 35(1), 61-76. DOI: https://dx.doi.org/10.4314/bcse.v35i1.5

203 Developing and Fine-Tuning Novel 3D-Printed Biodegradable Scaffolds to Promote Auricular Cartilaginous Regeneration for Surgical Implantation

Introduction

Microtia, a congenital cartilaginous defect, poses major challenges in cosmetic surgery. Biodegradable polymers promote chondrogenesis, with promises of seeding cells into synthetic-polymer-implants for surgical fixation. However, existing polymers used in auricular reconstruction present limitations including inflammation, fibrosis, and extrusion. This study aimed to modulate the mechanical properties of the novel polylactic-acid/polyhydroxyalkanoate (PLA/PHA) blend by 3D-printing and hence, evaluate its suitability to the auricular microenvironment in developing next-generation reconstructs.

Method

Digitally defined PLA/PHA scaffolds were free-form 3D-printed at various infill densities and thicknesses. Through tensile testing, tensile moduli, yield point, maximum strength, tensile toughness, and stiffness were calculated, alongside Finite Element Analysis (FEA) and contact angle tests. Finally, preliminary cell seeding was conducted.

Results

Increasing infill densities of PLA/PHA scaffolds from 30%-60% significantly increased tensile moduli, yield point and maximum strength (P &lt; 0.01). Tensile stiffness increased significantly with scaffold thicknesses between 1mm-2mm (P &lt; 0.05). Cell studies showed promising proliferative activity.

Conclusions

The mechanical properties and structural stiffness of 3D-printed PLA/PHA scaffolds can be significantly tailored by altering infill density and thickness, respectively. The digitally defined interconnected pores within printed PLA/PHA scaffolds reduce stiffness mismatches between surgical-synthetic polymers and auricular cartilage, potentially promoting cell migration and nutrition transportation in future reconstructs.