The discovery of novel and potent indazole NLRP3 inhibitors enabled by DNA-encoded library screening

NLRP3 is an intracellular sensor protein that detects a broad range of danger signals and environmental insults. Its activation results in a protective pro-inflammatory response designed to impair pathogens and repair tissue damage via the formation of the NLRP3 inflammasome. Assembly of the NLRP3 inflammasome leads to caspase 1-dependent secretory release of the pro-inflammatory cytokines IL-1β and IL-18 as well as to gasdermin d-mediated pyroptotic cell death. Herein, we describe the discovery of a novel indazole series of high affinity, reversible inhibitors of NLRP3 activation through screening of DNA-encoded libraries and the potent lead compound 3 (BAL-0028, IC50 = 25 nM) that was identified directly from the screen. SPR studies showed that compound 3 binds tightly (KD range 104-123 nM) to the NACHT domain of NLRP3. A CADD analysis of the interaction of compound 3 with the NLRP3 NACHT domain proposes a binding site that is distinct from those of ADP and MCC950 and includes specific site interactions. We anticipate that compound 3 (BAL-0028) and other members of this novel indazole class of neutral inhibitors will demonstrate significantly different physical, biochemical, and biological properties compared to NLRP3 inhibitors previously identified.

End to end stroke triage using cerebrovascular morphology and machine learning

Background

Rapid and accurate triage of acute ischemic stroke (AIS) is essential for early revascularization and improved patient outcomes. Response to acute reperfusion therapies varies significantly based on patient-specific cerebrovascular anatomy that governs cerebral blood flow. We present an end-to-end machine learning approach for automatic stroke triage.

Methods

Employing a validated convolutional neural network (CNN) segmentation model for image processing, we extract each patient's cerebrovasculature and its morphological features from baseline non-invasive angiography scans. These features are used to detect occlusion's presence and the site automatically, and for the first time, to estimate collateral circulation without manual intervention. We then use the extracted cerebrovascular features along with commonly used clinical and imaging parameters to predict the 90 days functional outcome for each patient.

Results

The CNN model achieved a segmentation accuracy of 94% based on the Dice similarity coefficient (DSC). The automatic stroke detection algorithm had a sensitivity and specificity of 92% and 94%, respectively. The models for occlusion site detection and automatic collateral grading reached 96% and 87.2% accuracy, respectively. Incorporating the automatically extracted cerebrovascular features significantly improved the 90 days outcome prediction accuracy from 0.63 to 0.83.

Conclusion

The fast, automatic, and comprehensive model presented here can improve stroke diagnosis, aid collateral assessment, and enhance prognostication for treatment decisions, using cerebrovascular morphology.

Decoding a cryptic mechanism of metronidazole resistance among globally disseminated fluoroquinolone-resistant Clostridioides difficile

Severe outbreaks and deaths have been linked to the emergence and global spread of fluoroquinolone-resistant Clostridioides difficile over the past two decades. At the same time, metronidazole, a nitro-containing antibiotic, has shown decreasing clinical efficacy in treating C. difficile infection (CDI). Most metronidazole-resistant C. difficile exhibit an unusual resistance phenotype that can only be detected in susceptibility tests using molecularly intact heme. Here, we describe the mechanism underlying this trait. We find that most metronidazole-resistant C. difficile strains carry a T-to-G mutation (which we term PnimB^G) in the promoter of gene nimB, resulting in constitutive transcription. Silencing or deleting nimB eliminates metronidazole resistance. NimB is related to Nim proteins that are known to confer resistance to nitroimidazoles. We show that NimB is a heme-dependent flavin enzyme that degrades nitroimidazoles to amines lacking antimicrobial activity. Furthermore, occurrence of the PnimB^G mutation is associated with a Thr82Ile substitution in DNA gyrase that confers fluoroquinolone resistance in epidemic strains. Our findings suggest that the pandemic of fluoroquinolone-resistant C. difficile occurring over the past few decades has also been characterized by widespread resistance to metronidazole.

Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510  GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02<x<0.08, with direct sensitivity to the sign of the gluon contribution.

Inoculum-dependent bactericidal activity of a Mycobacterium tuberculosis MmpL3 inhibitor

Indolcarboxamides are a promising series of anti-tubercular agents, which target Mycobacterium tuberculosis MmpL3, the exporter of trehalose monomycolate, a key cell-wall component. We determined the kill kinetics of the lead indolcarboxamide NITD-349 and determined that while kill was rapid against low-density cultures, bactericidal activity was inoculum-dependent. A combination of NITD-349 with isoniazid (which inhibits mycolate synthesis) had an increased kill rate; this combination prevented the appearance of resistant mutants, even at higher inocula.

Clinical outcomes for microvascular reconstruction in oral cancers: experience from a single surgical centre

INTRODUCTION

Reconstruction of a surgical defect is an important part of the management of oral cancers. Microvascular free flap construction provides better functional and cosmetic outcomes.

METHODS

Between 2014 and 2020, some 524 patients underwent microvascular reconstruction. Comorbidity variables were scored using the Charlson Comorbidity Index (CCI). Complications were recorded using Clavien-Dindo criteria.

RESULTS

Eighty-three (15.84%), 339 (64.69%) and 102 (19.47%) patients underwent free radial forearm flap, free anterolateral thigh flap and free fibula osteocutaneous flap (FFOCF), respectively. Clavien-Dindo complications of grade III and above were seen in 39 (7.44%) patients. Total flap loss was seen in 18 patients and of these, 16 were salvaged using alternative free flaps or pedicled flaps. On univariate analysis, overall and major complication rates were higher in FFOCF (p=0.171). Major complications significantly more common in patients with a CCI score >4 (p=0.001). Patients aged >65 years had higher rates of complications (p=0.03).

CONCLUSION

Microvascular free tissue transfer is a reliable, safe and gold standard modality in surgical reconstruction and can be replicated in non-institutional settings.

Inoculum-dependent bactericidal activity of a Mycobacterium tuberculosis MmpL3 inhibitor

Indolcarboxamides are a promising series of anti-tubercular agents which target Mycobacterium tuberculosis MmpL3, the exporter of trehalose monomycolate, a key cell wall component. We determined the kill kinetics of the lead indolcarboxamide NITD-349 and determined that while kill was rapid against low density cultures, bactericidal activity was inoculum-dependent. A combination of NITD-349 with isoniazid (which inhibits mycolate synthesis) had an increased kill rate; this combination prevented the appearance of resistant mutants, even at higher inocula.

Abstract 106: Novel Imaging-based Morphological Markers For Improved Prediction Of Stroke Outcomes: A Machine Learning Approach

Patient selection for acute reperfusion therapies of acute ischemic stroke is based on assessment of the core and tissue-at-risk and the time from stroke onset. Response to treatment and clinical outcomes, however, vary significantly since patient-specific cerebrovascular anatomy plays a vital role in governing flow and reperfusion. We developed an end-to-end automated machine learning approach to extract advanced cerebrovascular morphological features, including tortuosity and collateral index, to improve outcome prediction, and patient selection.

Methods: Using our validated automatic cerebrovascular segmentation and feature extraction algorithm, we obtained the morphological properties of the brain vasculature, including vessel tortuosity, length, diameter, and bifurcation patterns, in MR angiography scans of 100 anonymized stroke patients. Each patient’s collateral index was also automatically graded using a previously established probabilistic atlas of healthy cerebrovasculature. To predict 90-day functional outcomes (mRS), a statistical model was trained using patients' clinical features (demographics, comorbidities, and baseline NIHSS), imaging features (initial ASPECTS, perfusion mismatch volume, and collateral index), and the extracted morphologic features (length, diameter, number of branches, vessel tortuosity, fractal dimension, and total volume). The predictions were compared against ground truth mRS to assess model accuracy. We also compared the model’s performance against conventional outcome predictors with only the clinical and imaging features.

Results: The conventional model including the common clinical and imaging features excluding the collateral index gave an area under the curve (AUC) of 0.63, which is comparable to previously published results. Including the automatically scored collateral index improved the accuracy to 0.74. We found that further including the morphological features to the predictor model significantly improved AUC accuracy to 0.83.

Conclusion: Including automatically extracted cerebrovascular morphologic features in traditional clinical and imaging markers significantly improves outcome prediction and response to treatment in stroke patients.

Predicting the long-term impact of rotavirus vaccination in 112 countries from 2006 to 2034: A transmission modeling analysis

Rotavirus vaccination has been shown to reduce rotavirus burden in many countries, but the long-term magnitude of vaccine impacts is unclear, particularly in low-income countries. We use a transmission model to estimate the long-term impact of rotavirus vaccination on deaths and disability adjusted life years (DALYs) from 2006 to 2034 for 112 low- and middle-income countries. We also explore the predicted effectiveness of a one- vs two- dose series and the relative contribution of direct vs indirect effects to overall impacts. To validate the model, we compare predicted percent reductions in severe rotavirus cases with the percent reduction in rotavirus positivity among gastroenteritis hospital admissions for 10 countries with pre- and post-vaccine introduction data. We estimate that vaccination would reduce deaths from rotavirus by 49.1 % (95 % UI: 46.6-54.3 %) by 2034 under realistic coverage scenarios, compared to a scenario without vaccination. Most of this benefit is due to direct benefit to vaccinated individuals (explaining 69-97 % of the overall impact), but indirect protection also appears to enhance impacts. We find that a one-dose schedule would only be about 57 % as effective as a two-dose schedule 12 years after vaccine introduction. Our model closely reproduced observed reductions in rotavirus positivity in the first few years after vaccine introduction in select countries. Rotavirus vaccination is likely to have a substantial impact on rotavirus gastroenteritis and its mortality burden. To sustain this benefit, the complete series of doses is needed.

How Mycobacterium tuberculosis drug resistance has shaped anti-tubercular drug discovery

Drug resistance is an increasing problem for the treatment of tuberculosis. The prevalence of clinical isolates with pre-existing resistance needs to be considered in any drug discovery program. Non-specific mechanisms of resistance such as increased efflux or decreased permeability need to be considered both in developing individual drug candidates and when designing novel regimens. We review a number of different approaches to develop new analogs and drug combinations or improve efficacy of existing drugs that may overcome or delay the appearance of clinical resistance. We also discuss the need to fully characterize mechanisms of resistance and cross- resistance to existing drugs to ensure that novel drugs will be clinically effective.

Novel imaging markers for altered cerebrovascular morphology in aging, stroke, and Alzheimer's disease

BACKGROUND AND PURPOSE

Altered brain vasculature is a key phenomenon in several neurologic disorders. This paper presents a quantitative assessment of the anatomical variations in the Circle of Willis (CoW) and vascular morphology in healthy aging, acute ischemic stroke (AIS) and Alzheimer's Disease (AD).

METHODS

We used our novel automatic method to segment and extract geometric features of the cerebral vasculature from MR angiography scans of 175 healthy subjects, which were used to create a probabilistic atlas of cerebrovasculature and to study normal aging and intersubject variations in CoW anatomy. Subsequently, we quantified and analyzed vascular alterations in 45AIS and 50 AD patients, two prominent cerebrovascular and neurodegenerative disorders.

RESULTS

In the sampled cohort, we determined that the CoW is fully formed in only 35% of healthy adults and found significantly (p < .05) increased tortuosity and fractality, with increasing age and also with disease in both AIS and AD. We also found significantly lower vessel length, volume, and number of branches in AIS patients, as expected. The AD cerebral vessels exhibited significantly smaller diameter and more complex branching patterns, compared to age-matched healthy adults. These changes were significantly heightened (p < .05) among healthy, early onset mild AD, and moderate/severe dementia groups.

CONCLUSION

Although our study does not include longitudinal data due to paucity of such datasets, the specific geometric features and quantitative comparisons demonstrate the potential for using vascular morphology as a noninvasive imaging biomarker for neurologic disorders.

Design for Difference: Cognitive Enhancement Toys For Children with Developmental Delays

Childhood is a phase where children explore, learn and enjoy. For some children, this phase is full of difficulties. These children suffer from either developmental delays or learning difficulties. According to sources, there is a iniquitousness of 1.5-2.5% of advancing delay in kids below 2 years of age in India. Development is described into five different domains - gross motor, fine motor, speech, and language, cognitive and socio-emotional. These children need help at an early age to overcome developmental delays and for cognitive enhancement. Both parents and teachers are involved with children right from an early age, and they can devise ways to help these children. Many schools adopt ‘Play’ as an important activity to help these children overcome developmental delays and “toys” are mostly central to the design of such activities. The paper describes the design research for designing toys for cognitive enhancement of children with developmental delays between 2 and 5 years. In the first phase of research, the interview method was used to understand what kind of learning difficulties children face and what kind of methods are employed to teach them and understand what types of toys they are using. The sample size of 20 comprising of teachers, therapists, and pediatricians from Special schools and departments for special need children in mainstream schools was used for the interview purpose. Observational studies with children (5 different classrooms with children between 3-5 years age) were carried out to understand how children learn and use the toys. At the end of the first phase, the qualitative analysis led to the shift from learning difficulties to developmental delays. In the second phase, a survey of available products in the market was conducted to understand what types of toys are used to address these children’s developmental activity. Mapping the play methods employed by the teachers and therapists to the toys’ activities led to finding the Design gap. The design process incorporated the research findings. The product is designed in the form of a Toy Box with a multi-utility set of toys for cognitive enhancement in children with developmental delays. The design (three sets of toys) addresses children’s communication, spatial, cognitive, gross motor & fine motor skills with developmental delays. The designed product was put through user testing twice to incorporate the findings from the testing to make the design more user-friendly for the children and the teachers, therapists, and parents.

Importance of Toy Play in Special Education for young children: Perspectives and Approaches

Special needs children have different needs compared to typically growing children in various aspects of life. Their learning is hampered due to the difficulties they face in the normal way of learning. Special education practices have been adopting various play-based methods to address special needs children’s difficulties and needs. This research reviews toy play as a learning method and its importance in young special needs children’s education. The paper takes different perspectives on play and how it is characterized. A study of Toy Play taxonomies is also presented from the perspective of the learning needs of special needs children. Three prominent special education approaches are studied, and a synthesis of how to play fits into these approaches is presented. The future of toy play and further research areas is discussed. Early childhood play is a normal phenomenon that has much use in early intervention, early childhood special education, and early childhood education. Among these areas, there are still many disagreements about how to characterize and use play. These tensions jeopardize evaluation, action, and curriculum planning practices, as well as their links to science and practice. This essay examines play in early learning, early childhood special education, early childhood education, and how play is viewed and used in these settings.

Everyday Life of Slum Children: A Case study from Education Perspective

Every year, the city of Pune attracts migrant workers due to urbanization, and these migrants form residential pockets called slums. Today, around 40% of Pune’s population lives in urban slums, around 11% of children, who have little or no access to education with the everyday hand-to-mouth struggle for survival. This study explores the lives of slum children and their educational conditions. Three case studies were conducted with three slums from uptown areas of Pune. Focus group discussions, interviews, and visual survey methods were employed, leading to qualitative analysis. Analysis threw light on the everyday challenges faced by slum children in accessing education. The visual studies imply the need for architectural intervention. The findings also suggest policy implications towards the provision of education towards the betterment of the lives of slum children. Working and learning are the two social processes; without breaking the legal structures on child labor, children working within the home as domestic labor or in the household enterprise is a common occurrence in urban centers, particularly among those who are household income is derived from the informal sector and who have lower income levels. Working modes and times differ depending on the situation. Owing to the size of India’s informal economy and attempts to reduce child labor trafficking, a strong emphasis has been placed on developing and implementing social policies that address child labor.

573 The Changing Microbiology of Paediatric Neck Abscesses: Implications for Antibiotic Therapy

Aim

To provide an update on the microbiology, sensitivity rates and antibiotic prescribing patterns of drained superficial neck lymph node abscesses at Scotland's largest paediatric tertiary centre. Findings were compared to historical data from our institution. Analysis of the microbiology and epidemiological trends of paediatric neck abscesses is helpful for both antimicrobial stewardship purposes as well as to enhance the literature, given that paediatric-related conditions tend to be less well characterised when compared with adults.

Method

A retrospective case series of paediatric patients undergoing incision and drainage of a superficial neck lymph node abscess at the Royal Hospital for Children in Glasgow, 2018–2021. Patients were only included if they had culture and sensitivity testing performed on a sample obtained intra-operatively, were prescribed antibiotics, and were aged 16 years or younger.

Results

Thirty-nine abscesses were identified. Methicillin-susceptible Staphylococcus aureus remains the commonest organism (28%), followed by Streptococcus pyogenes (13%). Their prevalence is significantly lower in comparison to historical data. This was met by a shift towards a variety of rarer micro-organisms. 82% of patients were administered a drug regimen containing co-amoxiclav. Only 3 children required a change in their antibiotics.

Conclusion

Our case series highlights a fall in the yearly rate of drained neck abscesses. There was a significant change in causative micro-organisms, including a decrease in Staphylococcus aureus and an increase in the Streptococcus anginosus group. We recommend the use of co-amoxiclav empirically. In abscesses showing no clinical improvement, second-line options such as clindamycin, cefotaxime and vancomycin should be considered.

Precision Determination of the Neutral Weak Form Factor of ^{48}Ca

We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{48}Ca. We measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(q=0.8733  fm^{-1})=0.1304±0.0052(stat)±0.0020(syst) and the charge minus the weak form factor F_{ch}-F_{W}=0.0277±0.0055. The resulting neutron skin thickness R_{n}-R_{p}=0.121±0.026(exp)±0.024(model)  fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

AB0444 ENPATORAN: PRECLINICAL EVIDENCE SUPPORTING GLUCOCORTICOID DOSE REDUCTION AND PHASE II STUDY DESIGN IN PATIENTS WITH SLE AND/OR CLE (WILLOW)

Background

Enpatoran is a potent selective dual inhibitor of toll-like receptor (TLR) 7 and TLR8, aberrant activation of which may be involved in systemic lupus erythematosus (SLE) pathogenesis and glucocorticoid resistance.1,2,3 Enpatoran suppressed disease development in lupus mouse models, improving survival and reducing proteinuria, autoantibodies, and the interferon (IFN) gene signature.1 In healthy participants and patients hospitalized with COVID-19 pneumonia, enpatoran was well tolerated and demonstrated effective TLR7/8 engagement.4 Enpatoran is potentially glucocorticoid sparing and may help avoid the detrimental effects of long-term corticosteroid use in SLE management.5,6

Objectives

To evaluate the glucocorticoid-sparing effect of enpatoran and design a basket trial to assess its efficacy and safety in patients with SLE and/or cutaneous lupus erythematosus (CLE).

Methods

Cytokine concentrations and gene expression changes were measured in stimulated human peripheral blood mononuclear cells (PBMCs) from healthy donors after treatment with dexamethasone, TLR7/8 inhibitor, or both. A Phase II, basket design proof-of-concept, dose-finding study in patients with SLE and/or CLE (WILLOW) was designed.

Results

In healthy donor PBMCs, synergy was observed between TLR7/8 inhibitor and dexamethasone. Combination treatment inhibited cytokine release (IL-6) with greater potency than either treatment alone and reduced the expression of nuclear factor-kappa B and IFN-regulated genes. WILLOW is a Phase II, basket proof-of-concept, dose-finding, randomized, double-blind, placebo (PBO)-controlled 24-week study with two cohorts (NCT05162586, Figure 1). The primary objectives of WILLOW are to evaluate the dose–response relationship of enpatoran in reducing disease activity based on Cutaneous Lupus Erythematosus Disease Area and Severity Index-A (CLASI-A) or BILAG-Based Composite Lupus Assessment (BICLA) response rate. The secondary objectives are to investigate effects on both BICLA response and clinically meaningful corticosteroid reduction and evaluate disease control (including clinically meaningful corticosteroid reduction) in patients with predominantly active CLE or SLE. Cohort A will enroll patients with CLE (active subacute CLE and/or discoid LE) or SLE with predominantly active lupus rash. Cohort B, in two parts, will enroll SLE patients with moderate to severe systemic disease activity. Part 1 will assess clinical signal and Part 2 may be adapted to improve dose finding. Glucocorticoid-sparing will be evaluated by mandatory tapering to a prednisone-equivalent dose of ≤5 mg/day.

Figure 1.

WILLOW study design.

Cohort A and Cohort B Part 1 will start in parallel.

*Part 2 will be initiated after a pre-specified number of patients are enrolled in Part 1; enpatoran doses in Part 2 may be adapted to improve dose finding (dashed boxes).

BILAG, British Isles Lupus Assessment Group; CLASI-A, Cutaneous Lupus Erythematosus Disease Area and Severity Index-A; CLE, cutaneous lupus erythematosus; CS, corticosteroid; DBPC, double-blind placebo-controlled; DLE, discoid lupus erythematosus; PBO, placebo; SCLE, Subacute cutaneous lupus erythematosus; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index.

Conclusion

Enpatoran is a novel TLR7/8 inhibitor and may enable glucocorticoid dose reduction in patients with SLE and CLE. The WILLOW study incorporates multiple novel elements including a basket design and evaluation of glucocorticoid-sparing.

References

[1]Vlach, et al. J Pharmacol Exp Ther. 2021;376:397–409;

[2]Northcott, et al. Lancet Rheumatol. 2021;5:e357–e370;

[3]Guiducci, et al. Nature. 2010;465:937–941;

[4]Port, et al. Pharmacol Res Perspect. 2021;9:e00842;

[5]Thamer, et al. J Rheumatol. 2009;36:560–564;

[6]Ruiz-Irastorza, et al. Rheumatology. 2012;51:1145–1153.

Acknowledgements

This study was sponsored by the healthcare business of Merck KGaA, Darmstadt, Germany (CrossRef Funder ID: 10.13039/100009945), who funded medical writing support by Bioscript Stirling Ltd.

Disclosure of Interests

Eric F. Morand: None declared, Andrew Bender Shareholder of: Shares in Merck KGaA, Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Aditee Deshpande Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Bharat Vaidyanathan Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), cristina vazquez mateo Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Melinda Przetak Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Flavie Moreau Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Mukhy Khursheed Employee of: Merck Serono Ltd (an affiliate of Merck KGaA), Sanjeev Roy Employee of: Ares Trading SA (an affiliate of Merck KGaA), David Pearson Consultant of: Biogen Inc.

New Measurements of the Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering over a Range of Spin-0 Nuclei

We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of A_{n} for ^{40}Ca and ^{48}Ca are found to be similar to that of ^{12}C, consistent with expectations and thus demonstrating the validity of theoretical calculations for nuclei with Z≤20. We also report A_{n} for ^{208}Pb at two new momentum transfers (Q^{2}) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the Z≤20 nuclei. These data confirm our basic understanding of the underlying dynamics that govern A_{n} for nuclei containing ≲50 nucleons, but point to the need for further investigation to understand the unusual A_{n} behavior discovered for scattering off ^{208}Pb.

Measurement of Lepton-Jet Correlation in Deep-Inelastic Scattering with the H1 Detector Using Machine Learning for Unfolding

The first measurement of lepton-jet momentum imbalance and azimuthal correlation in lepton-proton scattering at high momentum transfer is presented. These data, taken with the H1 detector at HERA, are corrected for detector effects using an unbinned machine learning algorithm (multifold), which considers eight observables simultaneously in this first application. The unfolded cross sections are compared with calculations performed within the context of collinear or transverse-momentum-dependent factorization in quantum chromodynamics as well as Monte Carlo event generators.

328 Renal Cell Carcinoma (RCC) Metastasis to the Coracoid Process

A 51-year-old man was diagnosed with renal cell carcinoma (RCC) of the left kidney seven years ago. The tumour was staged as T2N0M0 and the patient underwent an uncomplicated open left radical nephrectomy. The RCC was classified as clear cell and he was kept on biannual renal surveillance thereafter.

Six years after the nephrectomy, the patient had reported a 5-month history of worsening pain and globally restricted movement in their right shoulder. A palpable mass on the coracoid process was noted. MRI imaging had shown a 27x30x17mm lesion suggestive of an expansile osseous mass in the coracoid process. An ultrasound guided biopsy was performed for definitive characterisation. Histology had reaffirmed that the lesion was in fact metastatic clear cell carcinoma in keeping with the patient’s renal primary. CT chest/abdomen/pelvis and NM-Bone SPECT CT scanning had shown no other sites of metastasis. A marginal resection of the lesion was performed with a good macroscopic clearance.

The common sites within the skeleton implicated in RCC include the spine, pelvis and femur. Tumours of the coracoid process are exceedingly rare. From the literature, only four cases of metastasis to the process have been noted: two from breast carcinoma, one from hepatocellular carcinoma and the other from basal cell carcinoma. Thus, this case denotes an extraordinary presentation for a metastasis of RCC many years after the nephrectomy. Furthermore, it emphasises the criticalness of regular follow-up and early intervention as delays could lead to systemic metastasis and a poorer prognosis.

A174 PERCEPTIONS OF CANNABIS USE IN WOMEN WITH INFLAMMATORY BOWEL DISEASE OF REPRODUCTIVE AGE: A CROSS-SECTIONAL STUDY

Background

Cannabis use in inflammatory bowel disease (IBD) may lead to improvement in pain and general health perception. However, its use during pregnancy may result in adverse outcomes such as preterm birth and altered fetal brain development. It remains unknown how women with IBD perceive Cannabis use during pregnancy and whether they discuss its use with their health-care providers.

Aims

To determine practices in, and perceptions of, cannabis use during pregnancy in women with IBD of reproductive age.

Methods

Women with IBD (age 18–45) were recruited at Mount Sinai Hospital and via social media platforms. Participants anonymously completed surveys on baseline demographics and IBD characteristics. They also completed a Cannabis questionnaire which asked about current use, perceived risks during pregnancy, and discussions with health-care providers. Categorical variables were reported as frequencies and compared using the chi-square test. Continuous variables were reported as medians and compared using the Mann-Whitney U test.

Results

Sixty-four women were included, 26 (40.6%) with ulcerative colitis, 37 (57.8%) with Crohn’s disease, and 1 (1.6%) with indeterminate colitis. Nineteen (29.7%) were preconception, 40 (62.5%) were pregnant, and 5 (7.8%) were post-partum. Eleven (18.0%) patients reported current Cannabis use, 4 (6.3%) during pregnancy. Cannabis users were more likely to have discussed its use with a health-care provider compared to non-users (45.5% vs. 5.7%, p&lt;0.001) and had longer IBD duration (12.00 vs. 9.00 years, p=0.05). Twenty-five (42.4%) were unsure of the risks of Cannabis use in pregnancy, of which only two had discussed this with a health-care provider. Reasons for fear of Cannabis use included risk of fetal oxygen restriction (n=13, 20.3%), impact on brain development (n=29, 46.0%), and risk of fetal respiratory issues (n=18, 28.6%). Only eight (12.5%) patients reported having a conversation about Cannabis use during pregnancy with their health-care provider; all of whom felt its consumption was unsafe during pregnancy.

Conclusions

Many women with IBD report being unsure of risks of Cannabis use during pregnancy. With the legalization of Cannabis in Canada, it is imperative patients and health-care providers discuss the risks and benefits of its use, particularly during vulnerable times such as pregnancy.

Funding Agencies

None

Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p^{↑}+p Collisions at sqrt[s]=200 GeV

Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in p^{↑}+p collisions at sqrt[s]=200  GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.

556 A Prospective Review of Risk Factors, Clinical Presentation and Management Outcomes for Chronic Pancreatitis

Aim

and objectives: To identify the risk factors, symptoms, and severity of Chronic pancreatitis (CP) on admission. To determine the relationship between pancreatic duct diameter and severity of pain and to assess extent of pain relief achieved by medical, endoscopic, and surgical intervention.

Method

75 patients with CP were admitted over 2 years. Data collected included etiology, symptoms, pain scores and CT/MRCP findings. Patients were classified into mild, moderate, and severe category according to Cambridge classification. Type and response to treatment was recorded. Statistical correlation of the pancreatic duct diameter and pain severity as well as the comparison of pain scores after medical, surgical and endoscopy was performed using Chi square test (p value &lt;0.05)

Results

Median age of presentation of CP was 43 years. Male: female ratio was 3:1. Alcohol was the etiology in 66 %, 99% presented with pain, 65 % belonged to severe category. There was no statistical correlation between pain severity and duct diameter. Pain relief following medical management was 66 %, endoscopic - 73% and surgical - 83 %. There was no correlation between Cambridge classification and pain severity. There was no statistical difference between pain relief offered by either of the three modalities. However, there was a statistically significant correlation between duct diameter and type of intervention.

Conclusions

There is no consensus on the best treatment modality for CP as pain relief was equivalent amongst all the modalities. Therefore, the choice of intervention for patients suffering from chronic pancreatitis should be based on imaging characteristics and symptomology.

696 Are Group and Save Samples Necessary for Common Urological Procedures?

Aim

Blood tests are routinely performed as a part of pre-operative assessment (pre-op). We looked at the number of group and save (G+S) samples taken at pre-op and compared that to the number of patients needing blood transfusion having undergone common Urological procedures at our hospital. Our objective was to assess the utility of this invasive procedure in this clinical setting.

Method

Data was retrospectively collected from electronic patient records on 413 patients undergoing elective urological procedures 1st June 2020 to 30th September 2020 at Colchester General Hospital. Major procedures like radical prostatectomies, nephrectomies were excluded. Patients who had G+S samples done prior to surgery were checked. This was compared to the patients who required transfusions.

Results

Amongst 413 patients who underwent an elective urological procedure, 169(41%) were day-case endoscopic, 151(37%) were inpatient, and 93(22%) were penoscrotal procedures. 104(25%) patients had G+S taken, with only 5 patients (1.2%) requiring transfusion. 24(14.2%) patients undergoing day case procedures,79(52.3%) patients undergoing inpatient procedures and 1(1.1%) patient undergoing penoscrotal procedures had G+S tests done. Only 7(1.7%) patients had a baseline haemoglobin of less than 100.

Conclusions

Our data showed that many G+S samples were unnecessary. TURBTs (transurethral resection of bladder tumours) were most likely to need transfusion. Education was fed-back to those running pre-operative assessment clinics that G+S should be considered for TURBTs and those with Hb &lt; 100. We recommend running this audit again to further quantify the G+S tests which could be avoided.

Reduced Susceptibility to Metronidazole Is Associated With Initial Clinical Failure in Clostridioides difficile Infection

Background

Clinical studies have demonstrated inferior cure rates when metronidazole (MTZ) is used to treat Clostridioides difficile infection (CDI). We hypothesized that a newly identified, heme-inducible form of reduced MTZ susceptibility in C. difficile leads to higher odds of initial clinical failure in patients with CDI treated with MTZ.

Methods

This multicenter cohort study included adults diagnosed with CDI between 2017 and 2018. C. difficile isolated from stool samples underwent agar dilution MTZ susceptibility testing with incorporation of fresh heme. Blinded investigators reviewed medical records for initial clinical failure and other relevant clinical variables. Classification and regression tree (CART) analysis was used to identify the MTZ minimum inhibitory concentration (MIC) breakpoint that was predictive of initial clinical failure. Results were confirmed using univariate and multivariable logistic regression analyses to account for potential confounders.

Results

Of the 356 patients included, 72% received MTZ-based therapy and 27% experienced initial clinical failure. CART analysis identified an MTZ MIC ≥1 µg/mL above which patients had a higher rate of initial clinical failure. MTZ MICs ranged from 0.25 to 8 µg/mL (MIC_50/90 = 0.25/2 µg/mL), and approximately 18% of isolates had MTZ MICs ≥1 µg/mL. In multivariable analysis, an MTZ MIC ≥1 µg/mL was an independent predictor of initial clinical failure in patients receiving an MTZ-based treatment regimen (odds ratio, 2.27 [95% confidence interval, 1.18–4.34]).

Conclusions

Using a reproducible method to determine C. difficile MICs to MTZ, a breakpoint of ≥1 µg/mL identified patients at higher risk of initial clinical failure.

Constitutive expression of the cryptic vanGCd operon promotes vancomycin resistance in Clostridioides difficile clinical isolates

OBJECTIVES

To describe, for the first time (to the best of our knowledge), the genetic mechanisms of vancomycin resistance in clinical isolates of Clostridioides difficile ribotype 027.

METHODS

Clinical isolates and laboratory mutants were analysed: genomically to identify resistance mutations; by transcriptional analysis of vanGCd, the vancomycin resistance operon encoding lipid II d-alanine-d-serine that is less bound by vancomycin than native lipid II d-alanine-d-alanine; by imaging of vancomycin binding to cell walls; and for changes in vancomycin bactericidal activity and autolysis.

RESULTS

Vancomycin-resistant laboratory mutants and clinical isolates acquired mutations to the vanSR two-component system that regulates vanGCd. The substitutions impaired VanSR's function, resulting in constitutive transcription of vanGCd. Resistance was reversed by silencing vanG, encoding d-alanine-d-serine ligase in the vanGCd operon. In resistant cells, vancomycin was less bound to the cell wall septum, the site where vancomycin interacts with lipid II. Vancomycin's bactericidal activity was reduced against clinical isolates and laboratory mutants (64 and ≥1024 mg/L, respectively) compared with WT strains (4 mg/L). Truncation of the potassium transporter TrkA occurred in laboratory mutants, which were refractory to autolysis, accounting for their survival in high drug concentrations.

CONCLUSIONS

Ribotype 027 evolved first-step resistance to vancomycin by constitutively expressing vanGCd, which is otherwise silent. Experimental evolutions and bactericidal assays show that ribotype 027 can acquire mutations to drastically enhance its tolerance to vancomycin. Thus, further epidemiological studies are warranted to examine the extent to which vancomycin resistance impacts clinical outcomes and the potential for these strains to evolve higher-level resistance, which would be devastating.

Day-case approach to immediate breast reconstruction: pushing the boundaries of ambulatory breast surgery in the post-COVID-19 era

INTRODUCTION

Day-case surgery is safe and efficacious for most breast surgical procedures. Limited data exist on its use in immediate breast reconstruction. We present our experience of day-case management of mastectomy with immediate pre-pectoral implant-based reconstruction (IBR).

METHODS

Data were collected on 47 patients who underwent day-case skin-sparing (SSM) or nipple-sparing (NSM) mastectomy with pre-pectoral IBR between October 2017 and September 2019. Clinicopathological data were collected, including postoperative complications, re-admission and re-operation. The data were compared to published national standards.

RESULTS

Median age was 52 years (range 37-74). Thirty-two patients (68%) had an SSM and 15 (32%) had an NSM. Two patients (4%) had risk-reducing mastectomies and 45 had treatment for invasive cancer or ductal carcinoma in situ (DCIS). Mean tumour size was 33.3mm (range 7-85mm). Forty-two (89%) patients went home on the day of surgery. No patients required re-operation in the first 48 hours. The median postoperative follow-up time was 11.4 months (range 1.8-22.7 months). During the first 90-day postoperative period, eight patients (17%) developed superficial skin necrosis, five patients (10.6%) developed postoperative infections and five patients (10.6%) suffered an implant loss. Eight patients (17%) were readmitted for re-operation. Compared to UK national standards set in the iBRA study, our cohort has demonstrated comparable postoperative infection, implant loss and re-operation and re-admission rates.

CONCLUSION

We have demonstrated close to 90% day-case success rate for mastectomy with IBR. These early data suggest that immediate IBR can be carried out in a manner that is cost-efficient without impacting surgical outcomes.

311 Can We Predict Extraprostatic Extension (EPE) Prior To Radical Prostatectomy? – A Single Institution Comparison of Pre-Operative Biopsy Histology and Multiparametric MRI (mpMRI) With Radical Prostatectomy Specimen Histology

Introduction

Prostate biopsies and mpMRI play an integral role in diagnosis of prostate cancer. The aim of our study was to assess the ability to predict EPE based on pre-operative histology and mpMRI.

Method

We retrospectively analysed 235 patients who underwent radical prostatectomy between January 2015 and April 2017. All patients underwent pre-biopsy mpMRI scans and prostate biopsies. All mpMRIs were reported by dedicated uro-radiologists and all histology was reported by dedicated uro-pathologists.

Results

17/25 patients showing EPE on mpMRI had it confirmed on final histology.

a53/210 patients showing organ-confirmed disease on mpMRI had EPE on final histology.

40/49 patients who had Gleason 6 adenocarcinoma were organ-confined.

61/186 patients with &gt; Gleason 7 adenocarcinoma had EPE.

Sensitivity of mpMRI was 25% with a specificity of 95%. The positive predictive value (PPV) was 68% and negative predictive value (NPV) was 75%.

The specificity of pre-biopsy Gleason score &gt; 7 to predict EPE was 81% and sensitivity was 33% with a PPV of 87%.

Conclusions

Our data suggests that by using &gt; Gleason 7 and mpMRI as a combination, we can reliably predict EPE on final histology which in turn will help counsel patients appropriately for treatment options. Further data collection is ongoing at our institution.

693 Are Virtual Clinics the New ‘Normal’? – A Single-Institution Comparative Analysis of Outcomes and Cost-Effectiveness of Virtual and Face-To-Face Clinics

Introduction

The coronavirus (COVID-19) pandemic has had a profound impact on clinicians, hospital resources and patients. Urology Virtual clinics (VCs) were initiated at our institution to ensure continued provision of service during the pandemic. The study aim was to analyse outcomes and cost-effectiveness of VCs compared to pre-COVID-19 face-to face (F2F) clinics.

Method

We retrospectively analysed the VCs from 18^th March 2020 to 1st July 2020 and compared them to F2F clinics in the same period in 2019. Clinical outcomes were compared, and potential financial savings were estimated to see if VCs can be incorporated into future practice.

Results

1317 patients were reviewed in 2020 as compared to 1941 in 2019. We noted similar rates of discharges [25.4% (2020) v/s 24.1% (2019)], follow-ups (48.7% (2020) v/s 48.4% (2019)] and patients who did not attend/answer (6.8% (2020) v/s 6.6% (2019)]. Potentially, over £100,000 can be saved by changing 50% appointments to VCs.

Conclusions

Our data shows that VCs are non-inferior to F2F clinics and have allowed continued effective service provision during the COVID-19 pandemic. There is potential to incorporate VCs into future practice without compromising on efficacy. Further data collection and analysis is ongoing at our institution on a larger scale.

Accurate Determination of the Neutron Skin Thickness of ^{208}Pb through Parity-Violation in Electron Scattering

We report a precision measurement of the parity-violating asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{208}Pb. We measure A_{PV}=550±16(stat)±8(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(Q^{2}=0.00616  GeV^{2})=0.368±0.013. Combined with our previous measurement, the extracted neutron skin thickness is R_{n}-R_{p}=0.283±0.071  fm. The result also yields the first significant direct measurement of the interior weak density of ^{208}Pb: ρ_{W}^{0}=-0.0796±0.0036(exp)±0.0013(theo)  fm^{-3} leading to the interior baryon density ρ_{b}^{0}=0.1480±0.0036(exp)±0.0013(theo)  fm^{-3}. The measurement accurately constrains the density dependence of the symmetry energy of nuclear matter near saturation density, with implications for the size and composition of neutron stars.

Microvascular reconstruction for head and neck cancers in high risk population: clinical outcomes and complications

INTRODUCTION

Microvascular reconstruction is the gold standard for reconstruction in oral cavity cancers. Age and comorbidities determine the type of reconstruction. We aimed to analyse the impact of high-risk comorbidities on perioperative morbidity.

METHODS

This is a retrospective study of 317 patients undergoing microvascular reconstruction from January 2014 to December 2017. High risk patients were based on age, American Society of Anaesthesiologists (ASA) grade (III/IV) and Charlson comorbidity index (CCI) score >4; overall, 73 out of 317 patients were evaluated.

RESULTS

Median age was 59 years. Five patients (6.8%) had complete flap failures and seven (9.5%) had minor complications (wound breakdown, bleeding, wound dehiscence, partial flap loss). ASA score of IV was significantly associated with morbidity while age >65 years and CCI >4 was not associated. The overall flap success rate was 93.2%.

CONCLUSIONS

A high-risk population has nearly similar outcomes for microvascular reconstruction as a younger age group. High ASA score adversely affects surgery-related outcomes.

Automatic segmentation, feature extraction and comparison of healthy and stroke cerebral vasculature

Accurate segmentation of cerebral vasculature and a quantitative assessment of its morphology is critical to various diagnostic and therapeutic purposes and is pertinent to studying brain health and disease. However, this is still a challenging task due to the complexity of the vascular imaging data. We propose an automated method for cerebral vascular segmentation without the need of any manual intervention as well as a method to skeletonize the binary segmented map to extract vascular geometric features and characterize vessel structure. We combine a Hessian-based probabilistic vessel-enhancing filtering with an active-contour-based technique to segment magnetic resonance and computed tomography angiograms (MRA and CTA) and subsequently extract the vessel centerlines and diameters to calculate the geometrical properties of the vasculature. Our method was validated using a 3D phantom of the Circle-of-Willis region, demonstrating 84% mean Dice similarity coefficient (DSC) and 85% mean Pearson's correlation coefficient (PCC) with minimal modified Hausdorff distance (MHD) error (3 surface pixels at most), and showed superior performance compared to existing segmentation algorithms upon quantitative comparison using DSC, PCC and MHD. We subsequently applied our algorithm to a dataset of 40 subjects, including 1) MRA scans of healthy subjects (n = 10, age = 30 ± 9), 2) MRA scans of stroke patients (n = 10, age = 51 ± 15), 3) CTA scans of healthy subjects (n = 10, age = 62 ± 12), and 4) CTA scans of stroke patients (n = 10, age = 68 ± 11), and obtained a quantitative comparison between the stroke and normal vasculature for both imaging modalities. The vascular network in stroke patients compared to age-adjusted healthy subjects was found to have a significantly (p < 0.05) higher tortuosity (3.24 ± 0.88 rad/cm vs. 7.17 ± 1.61 rad/cm for MRA, and 4.36 ± 1.32 rad/cm vs. 7.80 ± 0.92 rad/cm for CTA), higher fractal dimension (1.36 ± 0.28 vs. 1.71 ± 0.14 for MRA, and 1.56 ± 0.05 vs. 1.69 ± 0.20 for CTA), lower total length (3.46 ± 0.99 m vs. 2.20 ± 0.67 m for CTA), lower total volume (61.80 ± 18.79 ml vs. 34.43 ± 22.9 ml for CTA), lower average diameter (2.4 ± 0.21 mm vs. 2.18 ± 0.07 mm for CTA), and lower average branch length (4.81 ± 1.97 mm vs. 8.68 ± 2.03 mm for MRA), respectively. We additionally studied the change in vascular features with respect to aging and imaging modality. While we observed differences between features as a result of aging, statistical analysis did not show any significant differences, whereas we found that the number of branches were significantly different (p < 0.05) between the two imaging modalities (201 ± 73 for MRA vs. 189 ± 69 for CTA). Our segmentation and feature extraction algorithm can be applied on any imaging modality and can be used in the future to automatically obtain the 3D segmented vasculature for diagnosis and treatment planning as well as to study morphological changes due to stroke and other cerebrovascular diseases (CVD) in the clinic.

Oral Treatment With an Engineered Uricase, ALLN-346, Reduces Hyperuricemia, and Uricosuria in Urate Oxidase-Deficient Mice

Limitations in efficacy and/or tolerance of currently available urate-lowering therapies (ULTs), such as oral xanthine oxidase inhibitors, uricosurics, and intravenous uricase agents contribute to the development of refractory gout. Renal excretion is the major route of uric acid elimination, but the intestinal tract plays an increasingly recognized role in urate homeostasis, particularly in chronic kidney disease (CKD) in which the renal elimination of urate is impaired. We targeted intestinal degradation of urate in vivo with ALLN-346, an orally administered, engineered urate oxidase, optimized for proteolytic stability, and activity in the gut. We tested ALLN-346 in uricase/urate oxidase deficient mice (URKO mice) with severe hyperuricemia, hyperuricosuria, and uric acid crystalline obstructive nephropathy. A total of 55 male and female URKO mice were used in the two consecutive studies. These seminal, proof-of-concept studies aimed to explore both short- (7-day) and long-term (19-day) effects of ALLN-346 on the reduction of plasma and urine urate. In both the 7- and 19-day studies, ALLN-346 oral therapy resulted in the normalization of urine uric acid excretion and a significant reduction of hyperuricemia by 44 and 28% when therapy was given with food over 24 h or was limited for up to 6 h, respectively. Fractional excretion of uric acid (FEUA) was normalized with ALLN-346 therapy. Oral enzyme therapy with engineered urate oxidase (ALLN-346) designed to degrade urate in the intestinal tract has the potential to reduce hyperuricemia and the renal burden of filtered urate in patients with hyperuricemia and gout with and without CKD.

A Model for the Solution Structure of Human Fe(II)-Bound Acireductone Dioxygenase and Interactions with the Regulatory Domain of Matrix Metalloproteinase I (MMP-I)

The metalloenzyme acireductone dioxygenase (ARD) shows metal-dependent physical and enzymatic activities depending upon the metal bound in the active site. The Fe(II)-bound enzyme catalyzes the penultimate step of the methionine salvage pathway, converting 1,2-dihydroxy-5-(methylthio)pent-1-en-3-one (acireductone) into formate and the ketoacid precursor of methionine, 2-keto-4-thiomethyl-2-oxobutanoate, using O2 as the oxidant. If Ni(II) is bound, an off-pathway shunt occurs, producing 3-methylthiopropionate, formate, and carbon monoxide from the same acireductone substrate. The solution structure of the Fe(II)-bound human enzyme, HsARD, is described and compared with the structures of Ni-bound forms of the closely related mouse enzyme, MmARD. Potential rationales for the different reactivities of the two isoforms are discussed. The human enzyme has been found to regulate the activity of matrix metalloproteinase I (MMP-I), which is involved in tumor metastasis, by binding the cytoplasmic transmembrane tail peptide of MMP-I. Nuclear magnetic resonance titration of HsARD with the MMP-I tail peptide permits identification of the peptide binding site on HsARD, a cleft anterior to the metal binding site adjacent to a dynamic proline-rich loop.

Erratum: Evolution of π^{0} Suppression in Au+Au Collisions from sqrt[s_{NN}]=39 to 200 GeV [Phys. Rev. Lett. 109, 152301 (2012)]

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

Oncological outcomes in patients undergoing major glossectomy for advanced carcinoma of the oral tongue

INTRODUCTION

Major glossectomy is the treatment of choice in locally advanced tongue cancer. It remains the only option in the presence of recurrent or residual disease. The long-term outcomes for patients undergoing major glossectomy have traditionally been poor, with significant morbidity and poor oncological outcomes. The aim of this study was to report on oncological outcomes in patients undergoing major glossectomy.

METHODS

All patients undergoing major glossectomy between 2014 and 2018 were included in the study. The data of 85 patients with advanced carcinoma of the oral tongue were evaluated. All were under the care of a single surgical and reconstructive team at two hospitals in Mumbai.

RESULTS

The median patient age was 45 years. At the most recent follow-up, 55 patients (65%) were alive, 47 of whom were disease free. Twenty-nine patients (34%) had locoregional recurrence and twenty-five (29%) had distant metastasis. At a median follow-up of 19 months, rates for 2-year locoregional control, disease free survival (DFS) and overall survival (OS) were 69%, 61% and 62% respectively. Perinodal extension demonstrated a trend towards poor DFS (p=0.060), as did perineural invasion (p=0.055). Node positivity was a significant factor for poor OS, DFS and locoregional control. Multiple node involvement was significantly associated with poor OS on multivariate analysis (p=0.002).

CONCLUSIONS

Node positivity and multiple node involvement were associated with poor outcomes. Major glossectomy may be offered as a curative option for selected patients with advanced carcinoma of the oral tongue with node negative or limited neck nodal disease (N1).

Impact of comorbidities on perioperative outcomes for carcinoma of oral cavity

INTRODUCTION

Surgical management of oral cavity carcinoma involves composite resection with reconstruction. Comorbidities increase the risk of perioperative complications. Objective stratification is important for uneventful recovery. The Charlson Comorbidity Index and the Washington University Head and Neck Comorbidity Index were used to assess perioperative morbidity and mortality.

MATERIALS AND METHODS

This was a prospective study of 531 patients with head and neck squamous cell carcinoma who were treated between January 2014 and December 2017. Patients' comorbidity scores on the Charlson Comorbidity Index and Washington University Head and Neck Comorbidity Index were recorded.

RESULTS

The median age of the cohort was 49 years. Median Charlson Comorbidity Index score was 3 and Washington University Head and Neck Comorbidity Index was 0. There were five mortalities with a Charlson Comorbidity Index score of 4 or more. Fifteen patients had either infection, leak or postoperative bleeding. A Charlson Comorbidity Index of 4 or more was associated with higher event rate and poor overall survival (p=0.001).

CONCLUSION

Higher Charlson Comorbidity Index score is associated with increased incidence of peri-operative morbidity and mortality, while the Washington University Head and Neck Comorbidity Index is a poor predictor of the same.

840. Clinical Failure Rates Associated with Hemin-induced Metronidazole Resistance in Clostridioides difficile

Background

Current guidelines suggest limiting metronidazole (MTZ) use due to increased treatment failures in patients with Clostridioides difficile infections (CDI). We hypothesized that an increase in the minimum inhibitory concentration (MIC) of MTZ to C. difficile may contribute to these poor response rates. The objective of this study was to examine clinical response rates in patients with CDI based on MTZ MIC and stratified by receipt of MTZ treatment.

Methods

Clostridioides difficile-positive stool samples collected from 2017 to 2018 as part of routine care at two hospital systems in Houston, Texas were collected for MIC determination at 24 h to MTZ by broth microdilution following incorporation of 5 mg/L of hemin. The primary outcome was initial clinical success by Day 7 of treatment in those with MICs ≥1 vs. <1. Results were stratified based on receipt of MTZ within 48 hours of diagnosis. Study objectives were tested using χ 2 and multivariable logistic regression analyses.

Results

A total of 235 C. difficile samples were included, of which 73 (31%) had an MTZ MIC ≥1. Overall, 72% received MTZ within the first 48 hours. Clinical success rates differed based on disease severity (77% in nonsevere, 64% in severe/fulminant; P = 0.03) and infecting ribotype (52% in RT 027, 75% in non-RT 027; P = 0.014). In patients with MTZ receipt, clinical success rates were higher in patients infected with strains with an MTZ MIC < 1 (76%) compared with those with an MIC ≥1 (60%; P = 0.031). The difference in initial clinical success was not different in those that did not receive MTZ (78% for MIC <1 vs. 65% for MIC ≥1, P = 0.28). After controlling for disease severity, treatment failure was higher in patients infected with strains with an MTZ MIC ≥1 and treated with MTZ (OR 2.1; 95% CI, 1.01–4.35; P = 0.048) but not for those with an MIC ≥1 treated with other therapies (OR 1.9; 95% CI, 0.62–5.6; P = 0.27).

Conclusion

This study provides the first preliminary evidence of an association between reduced metronidazole susceptibility and decreased clinical success rates. Larger studies are warranted to validate these findings.

Disclosures

All Authors: No reported Disclosures.

Cross-sectional study of the prevalence, causes and management of hospital-onset diarrhoea

BACKGROUND

The National Health Service in England advises hospitals collect data on hospital-onset diarrhoea (HOD). Contemporaneous data on HOD are lacking.

AIM

To investigate prevalence, aetiology and management of HOD on medical, surgical and elderly-care wards.

METHODS

A cross-sectional study in a volunteer sample of UK hospitals, which collected data on one winter and one summer day in 2016. Patients admitted ≥72 h were screened for HOD (definition: ≥2 episodes of Bristol Stool Type 5-7 the day before the study, with diarrhoea onset >48 h after admission). Data on HOD aetiology and management were collected prospectively.

FINDINGS

Data were collected on 141 wards in 32 hospitals (16 acute, 16 teaching). Point-prevalence of HOD was 4.5% (230/5142 patients; 95% confidence interval (CI) 3.9-5.0%). Teaching hospital HOD prevalence (5.9%, 95% CI 5.1-6.9%) was twice that of acute hospitals (2.8%, 95% CI 2.1-3.5%; odds ratio 2.2, 95% CI 1.7-3.0). At least one potential cause was identified in 222/230 patients (97%): 107 (47%) had a relevant underlying condition, 125 (54%) were taking antimicrobials, and 195 (85%) other medication known to cause diarrhoea. Nine of 75 tested patients were Clostridium difficile toxin positive (4%). Eighty (35%) patients had a documented medical assessment of diarrhoea. Documentation of HOD in medical notes correlated with testing for C. difficile (78% of those tested vs 38% not tested, P<0.001). One-hundred and forty-four (63%) patients were not isolated following diarrhoea onset.

CONCLUSION

HOD is a prevalent symptom affecting thousands of patients across the UK health system each day. Most patients had multiple potential causes of HOD, mainly iatrogenic, but only a third had medical assessment. Most were not tested for C. difficile and were not isolated.

Nuclear Dependence of the Transverse Single-Spin Asymmetry in the Production of Charged Hadrons at Forward Rapidity in Polarized p+p, p+Al, and p+Au Collisions at sqrt[s_{NN}]=200 GeV

We report on the nuclear dependence of transverse single-spin asymmetries (TSSAs) in the production of positively charged hadrons in polarized p^{↑}+p, p^{↑}+Al, and p^{↑}+Au collisions at sqrt[s_{NN}]=200  GeV. The measurements have been performed at forward rapidity (1.4<η<2.4) over the range of transverse momentum (1.8<p_{T}<7.0  GeV/c) and Feynman x (0.1<x_{F}<0.2). We observed positive asymmetries for positively charged hadrons in p^{↑}+p collisions, and significantly reduced asymmetries in p^{↑}+A collisions. These results reveal a nuclear dependence of TSSAs for charged-hadron production in a regime where perturbative techniques are applicable. These results provide new opportunities to use p^{↑}+A collisions as a tool to investigate the rich phenomena behind TSSAs in hadronic collisions and to use TSSAs as a new handle in studying small-system collisions.