Extreme magnetoresistance at high-mobility oxide heterointerfaces with dynamic defect tunability

Magnetic field-induced changes in the electrical resistance of materials reveal insights into the fundamental properties governing their electronic and magnetic behavior. Various classes of magnetoresistance have been realized, including giant, colossal, and extraordinary magnetoresistance, each with distinct physical origins. In recent years, extreme magnetoresistance (XMR) has been observed in topological and non-topological materials displaying a non-saturating magnetoresistance reaching 103-108% in magnetic fields up to 60 T. XMR is often intimately linked to a gapless band structure with steep bands and charge compensation. Here, we show that a linear XMR of 80,000% at 15 T and 2 K emerges at the high-mobility interface between the large band-gap oxides γ-Al2O3 and SrTiO3. Despite the chemically and electronically very dissimilar environment, the temperature/field phase diagrams of γ-Al2O3/SrTiO3 bear a striking resemblance to XMR semimetals. By comparing magnetotransport, microscopic current imaging, and momentum-resolved band structures, we conclude that the XMR in γ-Al2O3/SrTiO3 is not strongly linked to the band structure, but arises from weak disorder enforcing a squeezed guiding center motion of electrons. We also present a dynamic XMR self-enhancement through an autonomous redistribution of quasi-mobile oxygen vacancies. Our findings shed new light on XMR and introduce tunability using dynamic defect engineering.

Apparent metabolizable energy and ileal amino acid digestibility of commercial soybean meals of different origins in broilers

We studied the chemical composition and the in vivo AMEn content and apparent (AID) and standardized (SID) ileal digestibility of CP and amino acids (AA) of 27 samples of soybean meals (SBM) from Argentina (ARG), Brazil (BRA), and USA, collected in Spain. On 88% DM basis, the BRA meals had more CP (46.9 vs. 46.0 and 45.9%; P < 0.05) and less sucrose (5.21 vs. 6.28 and 6.47%; P < 0.001) and stachyose (4.20 vs. 4.66 and 4.78%; P < 0.05) than the USA and ARG meals. Urease activity, protein dispersibility index, KOH protein solubility, and trypsin inhibitor activity values, were higher for the USA meals than for the South American meals (P < 0.05). In the in vivo trial, broilers received a common crumble diet from 0 to 16 d of age and then, their respective experimental diets (53% of a N-free diet and 47% of each of the 27 SBM tested) in mash form, for 5 d. The AMEn (2,334 vs. 2,282 and 2,277 kcal/kg; P = 0.062) and the AID (87.3 vs. 86.7 and 86.4%; P = 0.054) and SID (91.9 vs. 91.2 and 90.8%; P < 0.05) of the protein, were greater for the USA meals than for the ARG and BRA meals. In fact, the SID of Lys (93.5 vs. 93.0 and 92.1%; P < 0.001) and of the sum of Lys, Met, Thr, Trp, and Cys (91.4 vs. 91.0 and 90.2%; P < 0.05) were greater for the USA meals than for the ARG and BRA meals. In summary, the chemical composition, protein quality indicators, AMEn content, and ileal digestibility of the CP and the AA of the SBM, varied with the country of origin of the soybeans. In order to increase the accuracy of the feed formulation process, the composition and nutrient content of commercial batches of SBM, by country of origin should be controlled and periodically updated.

"It's not just the medical aspects that are important": A qualitative exploration of first-time parents' experiences of antenatal imaging and their influence on parent-fetal bonding

INTRODUCTION

Antenatal imaging provides clinical information regarding fetal growth and development. The additional benefit afforded by imaging for expectant parents in developing an emotional connection (bond) to the unborn baby is also acknowledged. However, the relationship between imaging and bonding is not fully understood, particularly where there are differing parental and pregnancy circumstances, for example use of advanced imaging techniques or the prenatal diagnosis of a congenital fetal condition. This study aimed to explore the role of antenatal imaging in enhancing the developing parent-fetal bond in first-time parents.

METHODS

A descriptive, qualitative methodology was used. Semi-structured telephone interviews were conducted with first-time expectant parents attending a London hospital for clinical ultrasound (n = 20) or research MRI (n = 8) imaging during pregnancy. The sample included parents receiving specialist antenatal care for a diagnosed fetal cardiac condition (n = 8). Thematic analysis was conducted.

RESULTS

The analysis generated three themes: 1) Our baby, our scan too; 2) Destination parenthood; and 3) Being in the dark, then finding the light. These themes highlight the important, but transient role of antenatal imaging in enhancing parent-fetal bonding, as well as the differing care needs of expectant parents. The integral role of healthcare professionals in providing a personalised, supportive, imaging experience to facilitate bonding is also reflected.

CONCLUSION

Adopting parent-centred care approaches which involve expectant parents in fetal imaging influences bonding by helping parents to consider the reality of their impending parenthood. Knowledge acquired during scans is used to create an identity for the unborn baby, which parents can develop an emotional connection to.

IMPLICATIONS FOR PRACTICE

To optimise the potential for enhanced parent-fetal bonding, care provision in fetal imaging should be tailored to the individual needs of expectant parents.

Whole-genome sequencing links cases dispersed in time, place, and person while supporting healthcare worker management in an outbreak of Panton-Valentine leucocidin meticillin-resistant Staphylococcus aureus; and a review of literature

This is a report on an outbreak of Panton-Valentine leucocidin-producing meticillin-resistant Staphylococcus aureus (PVL-MRSA) in an intensive care unit (ICU) during the COVID-19 pandemic that affected seven patients and a member of staff. Six patients were infected over a period of ten months on ICU by the same strain of PVL-MRSA, and a historic case identified outside of the ICU. All cases were linked to a healthcare worker (HCW) who was colonized with the organism. Failed topical decolonization therapy, without systemic antibiotic therapy, resulted in ongoing transmission and one preventable acquisition of PVL-MRSA. The outbreak identifies the support that may be needed for HCWs implicated in outbreaks. It also demonstrates the role of whole-genome sequencing in identifying dispersed and historic cases related to the outbreak, which in turn aids decision-making in outbreak management and HCW support. This report also includes a review of literature of PVL-MRSA-associated outbreaks in healthcare and highlights the need for review of current national guidance in the management of HCWs' decolonization regimen and return-to-work recommendations in such outbreaks.

ADT Use and Nodal Irradiation in Men Receiving Post-Prostatectomy Salvage Radiotherapy within a Statewide Radiation Oncology Quality Consortium

PURPOSE/OBJECTIVE(S)

For men with biochemical recurrence after radical prostatectomy, salvage radiotherapy (SRT) is a standard of care. Outcomes are improved when SRT is delivered at lower PSA levels, and there has been increased emphasis on more timely treatment. With early SRT, however, there remains uncertainty as to the optimal use and duration of androgen deprivation therapy (ADT) and pelvic lymph node radiation (PLNRT). Moreover, PET imaging and genomic classifiers have emerged as tools to guide treatment decisions, but their uptake in routine practice is unknown. To address these questions, we analyzed a contemporary cohort treated with SRT within the Michigan Radiation Oncology Quality Consortium (MROQC). We hypothesized that ADT and PLNRT practices would reflect recent trial results in this setting.

MATERIALS/METHODS

Eligible patients receiving SRT at an MROQC center were enrolled from 06/09/20 to 11/04/22. Data was prospectively collected via patient-, physician-, and physicist-completed forms. Patients were matched to the Michigan Urological Surgery Improvement Collaborative (MUSIC) database for additional treatment- and patient-related data. Univariable (UVA) and multivariable analyses (MVA) were performed to test associations between patient/tumor factors and ADT or PLNRT use.

RESULTS

A total of 191 patients across 26 centers were enrolled in the MROQC database. Of these, 116 were matched to the MUSIC database. Median time from RP to SRT was 17 months (IQR 8 - 33 months). The median post-RP PSA prior to SRT was 0.25 (IQR 0.16 - 0.60). Early SRT was defined as pre-SRT PSA ≤0.5, and 27% (n = 31/116) had a pre-SRT PSA >0.5. Twenty-eight were pT3b/T4, 97% were pN0/NX, and 51% had positive surgical margins. Fractionation was conventional (>28 fractions) in 58% and moderate hypofractionation (20-28 fractions) in 38%. Table 1 describes the patients receiving ADT and/or PLNRT. Median ADT duration was 6 mo (IQR 6 - 7 mo). MVA revealed pre-SRT PSA >0.5 (OR 5.05 [1.89 - 15.33]) and pT3b/T4 disease (OR 4.23 [1.40 - 14.56]) were significantly associated with ADT use (p <0.05), but not grade group (GG) or margin status. PLNRT was significantly associated with pre-SRT PSA >0.5 (OR 3.04 [1.21 - 8.42], p <0.05) but not pT stage, margin status, or GG. PET imaging was performed in 37% of men (52% negative, 21% prostate bed alone uptake, and 26% lymph node positivity) and genomic classifiers were performed in 24%.

CONCLUSION

Nearly 75% of biochemically recurrent prostate cancer patients within MROQC received early SRT, and about half received ADT. A pre-SRT PSA >0.5 was strongly associated with ADT and PLNRT. With prostate bed SRT alone, very few received ADT. Given the considerable heterogeneity in treatment, additional studies may help identify patients who most benefit from ADT + PLNRT, and who may be spared potential added toxicity.

Androgen Deprivation Therapy Use among Intermediate Risk Prostate Cancer Patients Undergoing Radiation Therapy across a Statewide Radiation Oncology Quality Consortium

PURPOSE/OBJECTIVE(S)

For men with intermediate (INT) risk prostate cancer, the addition of androgen deprivation therapy (ADT) reduces risk of PSA failure, distant metastasis, and cancer-related mortality. Moreover, the relative reduction in cancer-related adverse outcomes with ADT use appears consistent across all INT risk subgroups. The absolute benefit of ADT, however, varies by baseline risk. In contemporary practice, it is unknown which clinical factors are most strongly associated with intended ADT use. Therefore, we sought to identify such factors within the diverse practices of the Michigan Radiation Oncology Quality Consortium (MROQC).

MATERIALS/METHODS

Patients with localized prostate cancer undergoing definitive radiation therapy were enrolled from 6/9/20 to 11/4/22 (n = 599). Standardized patient, physician, and physicist forms were used to collect baseline and follow-up information. Intended ADT use, defined by the treating physician, was prospectively collected and is the primary outcome of this analysis. Univariable (UVA) and multivariable analyses (MVA) associations with patient (age, race, comorbidities), tumor (T stage, Gleason, percent cores positive, and PSA), and practice-related (academic vs private) factors were performed. In addition, advanced modality testing (PET, MRI, and genomic classifiers) was available as of March 2021, and subgroup analysis were performed where appropriate.

RESULTS

A total 351 patients across 26 centers were enrolled with INT risk disease. ADT use was intended for 46% of men (n = 162/351) which differed by men with NCCN favorable INT (21%, n = 22/105) vs unfavorable INT risk disease (57%, n = 140/246), p<0.001. Sixty two percent (n = 100/162) had an intended ADT duration of 4-6 months and 21% (n = 34/162) had ≥12 months. Older age was associated with ADT use (70 vs 67, p < 0.01); there were no significant differences by race or comorbidities number. MVA showed Gleason 4+3 (OR 4.61 [2.91 - 7.42]) and > = 50% positive cores (2.56 [1.52 - 4.37]) were significantly associated with ADT use. No significant differences were noted based on practice setting. Pelvic MRI was obtained for 71% of men (n = 197/279), genomic classifiers in 47% (n = 130/279), and PET in 2% (n = 6/282). In the subset with MRI (n = 197), adverse features (ECE, SVI, or equivocal LNs) were associated with intended ADT use (OR 3.0 [1.4 - 7.1]) after adjustment for NCCN favorable/unfavorable INT risk classification.

CONCLUSION

Within a state-wide consortium, intended ADT use for intermediate prostate cancer is most strongly associated with Gleason score, ≥50% positive cores, NCCN unfavorable intermediate risk classification, and adverse features on MRI. Nearly half of men had genomic classifier testing underscoring the importance ongoing trials such as NRG/GU 010.

A systematic review of the role of penicillin versus penicillin plus metronidazole in the management of peritonsillar abscess

BACKGROUND

Peritonsillar abscess is a localised infection in the peritonsillar space. Pus from the abscess can contain anaerobes. Many clinicians prescribe metronidazole in addition to penicillin, but evidence to support this is limited. This review assessed the evidence of benefit of metronidazole for the treatment of peritonsillar abscess.

METHODS

A systematic review was conducted of the literature and databases including Ovid Medline, Ovid Embase, PubMed and Cochrane library. Search terms included all variations of peritonsillar abscess, penicillin and metronidazole.

RESULTS

Three randomised, control trials were included. All studies assessed the clinical outcomes after treatment for peritonsillar abscess, including recurrence rate, length of hospital stay and symptom improvement. There was no evidence to suggest additional benefit with metronidazole, with studies suggesting increased side effects.

CONCLUSION

Evidence does not support the addition of metronidazole in first-line management of peritonsillar abscess. Further trials to establish optimum dose and duration schedules of oral phenoxymethylpenicillin would benefit clinical practice.

The role of cholecystectomy following endoscopic sphincterotomy and bile duct stone removal

INTRODUCTION

Choledocholithiasis is common, with patients usually treated with endoscopic retrograde cholangiopancreatography (ERCP) and subsequent cholecystectomy to remove the presumed source of common bile duct (CBD) stones. However, previous investigations into the management of patients following ERCP have focused on recurrent CBD stones, negating the risks of cholecystectomy. This article appraises the role of cholecystectomy following successful endoscopic clearance of bile duct stones.

METHODS

Patients undergoing ERCP and CBD clearance for choledocholithiasis at St James's University Hospital January 2015-December 2018 were included. Patients were divided into those who received cholecystectomy and those managed non-operatively. Readmissions, operative morbidity, mortality and treatment costs were investigated.

RESULTS

Eight hundred and forty-four patients received ERCP and CBD clearance with 3.9 years follow-up. Two hundred and nine patients underwent cholecystectomy with 15% requiring complex surgery. Three hundred and seventy-three patients were non-operatively managed. Unplanned readmissions occurred in 15% following ERCP, mostly within two years. There was no difference in readmissions between the two groups. Accounting for the entire patient pathway, non-operative management was less expensive.

CONCLUSIONS

The majority of patients do not require readmission following ERCP for CBD stones, and cholecystectomy did not reduce the risk of readmission. Few patients have recurrent CBD stones, but complex biliary surgery is frequently required. Routine cholecystectomy following ERCP needs to be re-evaluated and a more stratified approach to future risk developed.

A pragmatic digital health informatics based approach for aiding clinical prioritisation and reducing backlog of care: A study in cohort of 4022 people with diabetes

BACKGROUND AND AIMS

The backlog of care in resource stretched healthcare systems requires innovative approaches to aid clinical prioritisation. Our aim was to develop an informatics tool to identify and prioritise people with diabetes who are likely to deteriorate whilst awaiting an appointment to optimise clinical outcomes and resources.

MATERIALS AND METHODS

Using data from electronic health care records we identified 6 risk-factors that could be addressed in 4022 people (52% male, 30% non-Caucasian) with diabetes attending a large university hospital in London. The risk-factors were new clinical events/data occurring since their last routine clinic visit. To validate and compare data-led prioritisation tool to a traditional 'clinical approach' a sample of 450 patients were evaluated.

RESULTS

Of the 4022 people, 549 (13.6%) were identified as having one or more risk events/factors. People with risk were more likely to be non-Caucasian and had greater socio-economic deprivation. Taking clinical prioritisation as the gold standard, informatics tool identified high risk patients with a sensitivity of 83% and lower risk patients with a specificity of 81%. An operational pilot pathway over 3 months using this approach demonstrated in 101 high risk people that 40% received interventions/care optimisation to prevent deterioration in health.

CONCLUSION

A pragmatic data-driven method identifies people with diabetes at highest need for clinical prioritisation within restricted resources. Health informatics systems such as our can enhance care and improve operational efficiency and better healthcare delivery for people with diabetes.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Small mammals reduce activity during high moon illumination under risk of predation by introduced predators

Predation influences prey survival and drives evolution of anti-predator behaviour. Anti-predator strategies by prey are stimulated by direct encounters with predators, but also by exposure to indicators of risk such as moonlight illumination and vegetation cover. Many prey species will suffer increased risk on moonlit nights, but risk may be reduced by the presence of dense vegetation. Determining the role of vegetation in reducing perceived risk is important, especially given predictions of increased global wildfire, which consumes vegetation and increases predation. We used remote cameras in southeastern Australia to compare support for the predation risk and habitat-mediated predation risk hypotheses. We examined the influence of moonlight and understorey cover on seven 20-2500 g mammalian prey species and two introduced predators, red foxes and feral cats. Activity of all prey species reduced by 40-70% with increasing moonlight, while one species (bush rat) reduced activity in response to increasing moonlight more sharply in low compared to high understorey cover. Neither predator responded to moonlight. Our findings supported the predation risk hypothesis and provided limited support for the habitat-mediated predation risk hypothesis. For prey, perceived costs of increased predation risk on moonlit nights outweighed any benefits of a brighter foraging environment.

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

BACKGROUND

Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.

METHODS

This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low-middle-income countries.

RESULTS

In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of 'single-use' consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low-middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.

CONCLUSION

This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high- and low-middle-income countries.

Exploiting Real-Time Genomic Surveillance Data To Assess 4CMenB Meningococcal Vaccine Performance in Scotland, 2015 to 2022

The United Kingdom implemented the first national infant immunization schedule for the meningococcal vaccine 4CMenB (Bexsero) in September 2015, targeting serogroup B invasive meningococcal disease (IMD). Bexsero contains four variable subcapsular proteins, and postimplementation IMD surveillance was necessary, as nonhomologous protein variants can evade Bexsero-elicited protection. We investigated postimplementation IMD cases reported in Scotland from 1 September 2015 to 30 June 2022. Patient demographics and vaccination status were combined with genotypic data from the causative meningococci, which were used to assess vaccine coverage with the meningococcal deduced vaccine antigen reactivity (MenDeVAR) index. Eighty-two serogroup B IMD cases occurred in children >5 years of age, 48 (58.5%) of which were in unvaccinated children and 34 (41%) of which were in children who had received ≥1 Bexsero dose. Fifteen of the 34 vaccinated children had received one dose, 17 had received two doses, and two had received three doses. For 39 cases, meningococcal sequence data were available, enabling MenDeVAR index deductions of vaccine-preventable (M-VP) and non-vaccine-preventable (M-NVP) meningococci. Notably, none of the 19 of the children immunized ≥2 times had IMD caused by M-VP meningococci, with 2 cases of NVP meningococci, and no deduction possible for 17. Among the 15 children partially vaccinated according to schedule (1 dose), 7 were infected by M-VP meningococci and 2 with M-NVP meningococci, with 6 for which deductions were not possible. Of the unvaccinated children with IMD, 40/48 were ineligible for vaccination and 20/48 had IMD caused by M-VP meningococci, with deductions not being possible for 14 meningococci. IMPORTANCE This study demonstrates the value of postimplementation genomic surveillance of vaccine-preventable pathogens in providing information on real-world vaccine performance. The data are consistent with 2 and 3 doses of Bexsero, delivered according to schedule, providing good protection against invasive disease caused by meningococci deduced from genomic data to be vaccine preventable. Single doses provide poorer protection to infants. In practical terms, these data can provide public health reassurance when vaccinated individuals develop IMD with non-vaccine-preventable variants. They further indicate that additional testing is needed on variants for which no immunological data exist to improve estimates of protection, although these data suggest that the uncharacterized variants are unlikely to be covered by Bexsero. Finally, the confirmation that incomplete or absent doses in infancy lead to reduced protection supports public health and general practitioners in promoting vaccination according to schedule.

“It has been the most difficult time in my career”: A qualitative exploration of UK obstetric sonographers’ experiences during the COVID-19 pandemic

Introduction

Substantial changes were made to the provision of pregnancy ultrasound services during the COVID-19 pandemic with the intention of minimising virus transmission and maintaining service continuity. Published literature describing the impact of the pandemic on obstetric sonographers is predominantly quantitative in nature, however statistics cannot fully convey sonographers’ voices. This study aimed to gain a deeper understanding of the lived experiences of UK obstetric sonographers performing pregnancy ultrasound scans during the pandemic.

Methods

A UK-wide, online, anonymous cross-sectional survey on Qualtrics XM^TM was open to responses between 9^th March and 6^th May 2021. Whilst this survey contained some quantitative elements, open questions were included to capture additional qualitative detail from respondents about their perceptions and experiences of scanning during the pandemic. Key themes were generated from free text responses using thematic analysis.

Results

Written responses were received from 111/138 sonographers participating in the survey. Five themes were generated, depicting the impact of the pandemic on obstetric sonographers: 1) continuity in a crisis; 2) decisions about me, without me; 3) battle scars – the lasting damage of COVID-19; 4) what people think I do vs. what I really do; and 5) the human touch. A cross-cutting theme was sonographers’ feelings of disconnection from senior figures and expectant parents which created a sense of abandonment and distrust.

Conclusion

Survey respondents’ self-reported experiences of ineffective leadership and management, and perceived lack of understanding of the complexity of the sonographer role are potential contributory factors in the high levels of moral injury and occupational burnout reported within the workforce during the pandemic.

Implications for practice

Moral injury support and healing must be prioritised to enable the recovery of the obstetric ultrasound workforce in the post-pandemic era.

Measurement of SARS-CoV-2 in air and on surfaces in Scottish hospitals

BACKGROUND

There are still uncertainties in our knowledge of the amount of SARS-CoV-2 virus present in the environment - where it can be found, and potential exposure determinants - limiting our ability to effectively model and compare interventions for risk management.

AIM

This study measured SARS-CoV-2 in three hospitals in Scotland on surfaces and in air, alongside ventilation and patient care activities.

METHODS

Air sampling at 200 L/min for 20 min and surface sampling were performed in two wards designated to treat COVID-19-positive patients and two non-COVID-19 wards across three hospitals in November and December 2020.

FINDINGS

Detectable samples of SARS-CoV-2 were found in COVID-19 treatment wards but not in non-COVID-19 wards. Most samples were below assay detection limits, but maximum concentrations reached 1.7×10³ genomic copies/m³ in air and 1.9×10⁴ copies per surface swab (3.2×10² copies/cm² for surface loading). The estimated geometric mean air concentration (geometric standard deviation) across all hospitals was 0.41 (71) genomic copies/m³ and the corresponding values for surface contamination were 2.9 (29) copies/swab. SARS-CoV-2 RNA was found in non-patient areas (patient/visitor waiting rooms and personal protective equipment changing areas) associated with COVID-19 treatment wards.

CONCLUSION

Non-patient areas of the hospital may pose risks for infection transmission and further attention should be paid to these areas. Standardization of sampling methods will improve understanding of levels of environmental contamination. The pandemic has demonstrated a need to review and act upon the challenges of older hospital buildings meeting current ventilation guidance.

Determining the gluonic gravitational form factors of the proton

The proton is one of the main building blocks of all visible matter in the Universe¹. Among its intrinsic properties are its electric charge, mass and spin². These properties emerge from the complex dynamics of its fundamental constituents-quarks and gluons-described by the theory of quantum chromodynamics^3-5. The electric charge and spin of protons, which are shared among the quarks, have been investigated previously using electron scattering². An example is the highly precise measurement of the electric charge radius of the proton⁶. By contrast, little is known about the inner mass density of the proton, which is dominated by the energy carried by gluons. Gluons are hard to access using electron scattering because they do not carry an electromagnetic charge. Here we investigated the gravitational density of gluons using a small colour dipole, through the threshold photoproduction of the J/ψ particle. We determined the gluonic gravitational form factors of the proton^7,8 from our measurement. We used a variety of models^9-11 and determined, in all cases, a mass radius that is notably smaller than the electric charge radius. In some, but not all cases, depending on the model, the determined radius agrees well with first-principle predictions from lattice quantum chromodynamics¹². This work paves the way for a deeper understanding of the salient role of gluons in providing gravitational mass to visible matter.

First Constraints on Light Sterile Neutrino Oscillations from Combined Appearance and Disappearance Searches with the MicroBooNE Detector

We present a search for eV-scale sterile neutrino oscillations in the MicroBooNE liquid argon detector, simultaneously considering all possible appearance and disappearance effects within the 3+1 active-to-sterile neutrino oscillation framework. We analyze the neutrino candidate events for the recent measurements of charged-current ν_{e} and ν_{μ} interactions in the MicroBooNE detector, using data corresponding to an exposure of 6.37×10^{20} protons on target from the Fermilab booster neutrino beam. We observe no evidence of light sterile neutrino oscillations and derive exclusion contours at the 95% confidence level in the plane of the mass-squared splitting Δm_{41}^{2} and the sterile neutrino mixing angles θ_{μe} and θ_{ee}, excluding part of the parameter space allowed by experimental anomalies. Cancellation of ν_{e} appearance and ν_{e} disappearance effects due to the full 3+1 treatment of the analysis leads to a degeneracy when determining the oscillation parameters, which is discussed in this Letter and will be addressed by future analyses.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

271 DEVELOPMENT OF AN INNOVATIVE INTER-DISCIPLINARY PARKINSON’S CLINIC IN AN AMBULATORY CARE SETTING

Background

Ambulatory services provide specialist outpatient care, reducing costs associated with inpatient admissions and enabling the person to remain at home for longer (Report of the National Acute Medicine Programme, 2010). An Older Person’s Ambulatory Care Hub was established in a large teaching hospital. Prior service evaluation demonstrated that approximately one third of patients attending had a diagnosis of Parkinson’s Disease (PD). People with PD should have a collaborative approach between patient, family and healthcare providers to optimally manage their condition (NICE, 2017), therefore, the need was identified to evolve the traditional medical model to an interdisciplinary approach. The aim of this project was to complete a service evaluation and breakdown of Interdisciplinary Team (IDT) referrals.

Methods

An IDT working group including Clinical Nutrition (CN), Medical, Nursing, Occupational Therapy (OT), Physiotherapy (PT), and Speech and Language Therapy (SLT) was established. A comprehensive assessment form was developed and outcome measures were chosen. A short pilot was conducted and necessary amendments were made. A weekly clinic was established which included an IDT assessment, followed by a huddle with the medical team where referrals were generated. Data pertaining to the number of attendees and referrals generated were collected over a 3-month period.

Results

Over the data collection period, 31 patients attended the clinic. Referrals were as follows; Medical: 19, PT: 13, SLT: 10, OT: 7, CN: 6, Medical Social Work: 2. Patients requiring urgent medical review were seen immediately after the IDT huddle.

Conclusion

This project demonstrates a service evaluation of a novel IDT PD Clinic. This clinic highlights the need for an IDT approach to management of people with PD. Future service developments include obtaining patient feedback, pre-clinic calls to patients by a Healthcare Assistant to explain the purpose of the clinic, and adapting the clinic as appropriate.

Measured proton electromagnetic structure deviates from theoretical predictions

The visible world is founded on the proton, the only composite building block of matter that is stable in nature. Consequently, understanding the formation of matter relies on explaining the dynamics and the properties of the proton's bound state. A fundamental property of the proton involves the response of the system to an external electromagnetic field. It is characterized by the electromagnetic polarizabilities¹ that describe how easily the charge and magnetization distributions inside the system are distorted by the electromagnetic field. Moreover, the generalized polarizabilities² map out the resulting deformation of the densities in a proton subject to an electromagnetic field. They disclose essential information about the underlying system dynamics and provide a key for decoding the proton structure in terms of the theory of the strong interaction that binds its elementary quark and gluon constituents. Of particular interest is a puzzle in the electric generalized polarizability of the proton that remains unresolved for two decades². Here we report measurements of the proton's electromagnetic generalized polarizabilities at low four-momentum transfer squared. We show evidence of an anomaly to the behaviour of the proton's electric generalized polarizability that contradicts the predictions of nuclear theory and derive its signature in the spatial distribution of the induced polarization in the proton. The reported measurements suggest the presence of a new, not-yet-understood dynamical mechanism in the proton and present notable challenges to the nuclear theory.

Social media and use of electronic nicotine delivery systems among school-going adolescents in a rural distressed Appalachian community

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Social media use to discuss ENDS among youth in distressed areas is understudied.

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Nearly 1 in 3 and 1 in 8 of youth were ever and current ENDS users, respectively.

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Nearly 1 in 5 of the youth reported using social media to talk about ENDS.

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Social media increased current and ever ENDS use by 4 and 3 times, respectively.

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Social media engagement may lead to ENDS uptake among youth in distressed areas.

Electronic nicotine delivery systems (ENDS) are the most used tobacco products among middle and high schoolers in the United States (U.S.). Familial relations and access play a major role in uptake among adolescents; yet the role of social media in this phenomenon in the context of communities impacted by tobacco-related health disparities is understudied. In Spring 2019, data were collected from adolescents in 8th and 9th grades in a school located in a rural distressed county in Tennessee to assess social media’s role in ENDS uptake. Descriptive and multivariable statistical analyses were performed to delineate factors associated with ENDS use. Of a total of 399 respondents, 12.5 % reported current ENDS use and 22.1 % indicated having ever discussed ENDS on social media. Closed messaging platforms (Snapchat) and video platforms (Facebook/Instagram/You Tube) were the most reported form of social media used (8.31 % and 8.31 % respectively). Social media use was positively associated with both ever ENDS use (odds ratio [OR] = 2.9) and current ENDS use (OR = 3.98). Parental advice against ENDS use was positively associated with ever ENDS use. In conclusion, social media use was positively associated with both ever and current ENDS use, and Snapchat was the most popular platform among this population of students. The results indicate that youth social media engagement may lead to exposure that can influence ENDS uptake. Future studies are needed to further examine these associations among distressed communities.

P12.07.B Getting to the core of microglia versus bone marrow-derived macrophages in glioblastoma

Background

Microglia and bone marrow-derived macrophages (BMDMs) are two ontogenetically distinct myeloid populations present within glioblastoma that can comprise 30-50% of the tumour mass. Historically, these cell types have been conflated and studied as a single population of ‘tumour-associated macrophages’. Recent advances in single-cell omics have allowed population delineation, suggesting microglia and BMDMs may play different roles within the tumour and subsequently differentially affect tumour progression. Despite building evidence for the unique functions of these cells within glioblastoma, the inherent heterogeneity of the tumour landscape has complicated such studies. Indeed, macrophages exist as phenotypically and functionally diverse populations that are polarised in a context-dependent manner. Hence, to understand the differences between microglia and BMDMs within glioblastoma, both ontogeny and spatial location must be considered.

Material and Methods

To elucidate the functional roles of microglia and BMDMs across the tumour landscape, a publicly available RNAseq dataset was utilised to classify myeloid cells into four populations based on spatial location and ontogeny. These were tumour core BMDMs and microglia, or tumour periphery BMDMs and microglia. Differential gene analysis was then performed to identify significant differentially expressed genes (DEGs) between classified myeloid populations. Tumour core DEGs were then compared against the Ivy Glioblastoma Atlas to define their expression across anatomical tumour regions. Finally, myeloid DEGs were validated at the protein level on human glioblastoma tissue through immunohistochemistry.

Results

Microglia and BMDMs showed different spatial distributions across the tumour landscape and displayed distinct functional expression profiles. Microglia held a more chemotactic and pro-inflammatory profile, whereas BMDMs held a more pro-tumoural profile. However, a comparison of microglia between the tumour core and periphery revealed that tumour microglia upregulate many pro-tumoural genes, including multiple genes that have previously been defined as ‘BMDM-enriched’. Moreover, we found myeloid DEGs identified within the tumour core cluster to distinct spatial tumour regions such as the vascular or hypoxic niche. Immunohistochemical staining reflected these spatial expression profiles, identifying a distinct population of phagocytic macrophages within the hypoxic niche.

Conclusion

Although microglia and BMDMs represent two ontogenetically distinct myeloid populations within glioblastoma, both cell types can adopt similar functional expression profiles within the tumour core, particularly within tumour niches. This indicates that myeloid cell function is strongly influenced by the tumour microenvironment, rather than ontogeny alone.

The association between statistical shape modeling-defined hip morphology and features of early hip osteoarthritis in young adult football players: Data from the femoroacetabular impingement and hip osteoarthritis cohort (FORCe) study

Objective

To explore the relationship between radiographic hip shape and features of early hip osteoarthritis (OA) on magnetic resonance imaging (MRI) in young male and female football players without radiographic hip OA.

Design

We used baseline data from a cohort of symptomatic and asymptomatic football players aged 18-50 years. Hip shape was assessed on anteroposterior radiographs with statistical shape modeling (SSM) for men and women separately. Cartilage defects and labral tears were graded using the Scoring Hip Osteoarthritis with MRI (SHOMRI) system. We used logistic regression with generalized estimating equations to estimate associations between each hip shape variant, called shape modes, and cartilage defects or labral tears.

Results

We included 229 participants (446 hips, 77.4% male). For each sex, 15 shape modes were analyzed. In men, three shape modes were associated with cartilage defects: adjusted odds ratios (aOR) 0.75 (95%CI 0.58-0.97) per standard deviation (SD) for mode 1; 1.34 (95%CI 1.05-1.69) per SD for mode 12; and 0.61 (95%CI 0.48-0.78) per SD for mode 15; and one also with labral tears: aOR 1.30 (95%CI 1.01-1.69) per SD for mode 12. These modes generally represented variations in the femoral neck and subtypes of cam morphology, with and without pincer morphology. For women, there was no evidence for associations with the outcomes.

Conclusions

Several hip shape variants were associated with cartilage defects on MRI in young male football players. Specifically, one subtype of cam morphology was associated with both cartilage defects and labral tears. Hip shape was not associated with early OA features in women.

147 Synchronous Parathyroidectomy and Extended Thymectomy in Multiple Endocrine Neoplasia Type 1- a Case Report

In recent decades there has been a significant advancement in the management of neuroendocrine tumours (NETs) associated with multiple endocrine neoplasia type 1 (MEN-1). Hormone excess accounted for 75% of all MEN-1 deaths, however since the introduction of hormone blocking medication, deaths in patients with MEN-1 are now predominantly due to the malignant effects of the tumours. Half of all MEN-1 related deaths are due to tumours that are difficult to diagnose, including thymic NETs. Complete surgical resection is the mainstay of treatment for MEN-1 associated thymic NETs.

The case patient was a 49-year-old male who was being investigated for a 3-month history of symptoms consistent with hypercalcaemia. Initially a chest X-ray demonstrated a large anterior mediastinal mass. Further imaging revealed parathyroid lesions and a calcified lesion in the uncinate process of the pancreas. This combination of symptoms and radiological evidence raised the possibility of MEN-1 as the diagnosis. The lesions were biopsy-proven atypical carcinoid NETs and the patient later underwent simultaneous neck dissection for bilateral subtotal parathyroidectomy and a midline sternotomy for total thymectomy of the large mediastinal mass. Further testing revealed the pancreatic mass was another primary tumour and the patient is scheduled for excision of this. In addition, the patient is also being treated with Lanreotide alongside chemotherapy. Mutation of the MEN-1 gene was later confirmed on genetic testing.

Due to the increase in mortality from neuroendocrine malignancy, it is becoming ever more important to understand how to manage multiple NETs from a surgical perspective.

137 Salvage Pulmonary Resection in Stage IIIb-IV Lung Cancer After Treatment with Immune Checkpoint Inhibitors - A Case Series

Aim

Immune checkpoint inhibitors (ICIs) have been shown to prolong survival in patients that have locally advanced stage III/IV and metastatic non-small cell lung cancer (NSCLC). The role that salvages surgery plays in persistent localised disease and unresponsive synchronous cancer following treatment with a course of ICIs is not yet fully clear. We present a case series of nine patients with stage III/IV NSCLC that underwent surgical resection after treatment with the ICI, pembrolizumab.

Method

Six cases underwent salvage surgery after downstaging of the primary cancer following pembrolizumab treatment and three patients had resection of contralateral lung nodules that were unresponsive to ICI therapy. Three of the cases were open thoracotomies, 3 were robotic-assisted and 2 were video-assisted. One case was converted to open due to pulmonary artery involvement.

Results

There was complete, successful macroscopic resection in all cases with each showing histological evidence for active cancer cells. One patient died of COVID pneumonitis in the community within 60 days of surgery. All other patients are alive with no evidence of localised disease or of any disease reoccurrence within 3–18 months of their surgery.

Conclusions

Our case series demonstrates the potential for salvage pulmonary resection in select patients with advanced stage NSCLC who have persistent localised disease or unresponsive synchronous cancer after treatment with the ICI, pembrolizumab. Salvage surgery in this group of patients is safe and pragmatic despite high levels of post-immunotherapy hilar fibrosis. Further studies will be required in order to assess overall survival rates.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

O003 Radiation-related chromosomal aberrations observed in high volume endovascular operators performing X-ray guided surgery

Introduction

The biological effects of chronic, low dose radiation, to which operators performing fluoroscopy-guided procedures are exposed, are unknown. We have previously demonstrated acute DNA damage/repair in lymphocytes from operators performing fluoroscopy-guided endovascular aneurysm repair (EVAR), but these markers normalised after 24 hours and did not inform on the residual accumulated effects of chronic radiation exposure. In the present study cytogenetic techniques were used to examine for chromosomal aberrations in endovascular operators.

Methods

Peripheral blood lymphocytes were isolated from high volume endovascular operators performing EVAR and age-matched radiation naïve general surgeons as controls. Giemsa staining was used to visualise the full complement of chromosomes and all dicentrics, where 2 centromeres are present in a single chromosome, were identified. The genome was analysed for abnormal exchanges of genetic material between chromosomes using multiplex fluorescence in situ hybridisation (mFISH).

Results

Lymphocytes from 18 operators (12 exposed, 6 controls) were analysed. A higher frequency of dicentric chromosomes were found in exposed operators compared with controls (0.0011 vs 0.0004, respectively, P=0.002) after examining 54,000 lymphocytes. Twice as many complex chromosome rearrangements were seen in endovascular operators compared with controls (0.48% vs 0.24%). Aneuploidy, the abnormal loss of chromosomes, was more frequent in endovascular operators with a median difference of 0.35 per chromosome (P=0.004).

Conclusion

We have found a higher frequency of chromosomal aberrations in endovascular operators compared with radiation naïve colleagues. This justifies further individual biological profiling for genomic instability and personalised radiation risk assessment.

Take-home message

Radiation-related DNA damage occurs in endovascular operators despite current radiation protection measures. Biological dosimetry could be a useful tool, allowing personalised risk assessment.

O079 Predictive value for elevated platelet-derived SGPVI in venous in-stent stenosis in patients with post-thrombotic syndrome

Introduction

In-stent stenosis following intervention for post-thrombotic syndrome (PTS) occurs in ∼30% of cases, despite therapeutic anticoagulation. Our aim was to investigate whether platelets are involved.

Methods

Blood was taken from case-matched patients before and after venous stenting. Flow-cytometry was used to assess platelet activation (P-selectin and/or phosphatidylserine exposure) while= functional activity was measured by plate-based aggregation and through a flow-cell model of thrombus formation. Soluble glycoprotein VI (sGPVI) was measured in plasma. Patients with in-stent stenosis requiring reintervention (&gt;50% diameter reduction) were compared with those who did not.

Results

Forty-five patients were recruited (median age: 43yrs (33–55yrs); 65% female), and 19/45 (42%) required reintervention (median time: 3wks (1day-3mths)). There was no difference in platelet activation or reactivity after stenting, but P-selectin exposure pre-stent was significantly higher in patients who developed in-stent stenosis (2.7%±0.4 vs 1.7%±0.2; P&lt;0.05). Pre-stent sGPVI levels were increased in patients who developed in-stent stenosis (18.9±3.6ng/mL vs. 7.4±0.9ng/mL; P&lt;0.01). Platelet reactivity to collagen-related peptide, a GPVI-specific platelet agonist, was reduced in patients who developed in-stent stenosis (logEC50 = -6.5M±0.3 vs -7.2M±0.2; P&lt;0.05; n=33). Pre-stent platelet accumulation (26.6AU±0.5 vs 19.0AU±8.1; P=0.04) was significantly increased in PTS patients compared with healthy controls.

Conclusion

Venous stenting does not activate platelets, but patients who developed in-stent stenosis exhibited greater levels of pre-stent platelet activation, greater loss of platelet surface GPVI in the form of sGPVI and reduction in reactivity to GPVI activation. sGPVI may have potential to risk stratify patients undergoing venous stenting and predict who requires closer surveillance.

Take-home message

Soluble GPVI may have potential to risk-stratify patients undergoing deep venous reconstruction and predict who requires closer surveillance.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Novel KEL allele associated with loss of Kpb identified in a white blood donor

The importance of identifying variant alleles among blood donors is significant to the safety of transfusion for recipients. Molecular methods have become more prominent in the routine process of antigen typing donor units. Some variant antigens cannot be detected using only serologic methods. Molecular testing allows the determination of nucleotide sequences that are used to predict a phenotype. Antigens of the Kell blood group system are known for being highly immunogenic and causing adverse reactions upon antibody formation. A female white blood donor who typed Kp(b-) using serologic methods on multiple donations since 2005 was the subject of a typing discrepancy investigation. Routine genotyping using a commercial genotyping kit (HemoID DQS Panel; Agena Bioscience, San Diego, CA) predicted the donor to type Kp(a+b+). Investigation of the discrepancy between these two results identified a rare single nucleotide variant in the KEL gene at nucleotide position c.948G>T that alters amino acid residue 316 from tryptophan (Trp) to cysteine (Cys). After discovery of the novel allele, adsorption and elution studies were performed to see if there was weakened Kp^b expression. The elution studies yielded negative results, which indicated that Kp^b is not expressed. The KEL transcripts expressed by the donor were determined using cDNA analysis, and the predicted amino acid sequence of the novel allele was modeled to investigate the impact of the amino acid sequence on the structure of the KEL polypeptide. Both SWISS-MODEL and Robetta software were used to evaluate the impact of the p.Trp316Cys on the three-dimensional protein structure. There was no conformational change noted with SWISS-MODEL, whereas the Robetta software showed a significant conformational change compared with the normal Kp(b+) reference sequence. Because the donor is homozygous for variants associated with k and Js^b expression, it was not possible to determine whether the novel allele is associated with loss of Kp^b only or loss of all Kell antigens.

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.

Subclinical infection occurs frequently following low dose exposure to prions by blood transfusion

Infectious prion diseases have very long incubation periods, and the role that subclinical infections play in transmission, persistence and re-emergence of these diseases is unclear. In this study, we used a well-established model of vCJD (sheep experimentally infected with bovine spongiform encephalopathy, BSE) to determine the prevalence of subclinical infection following exposure by blood transfusion from infected donors. Many recipient sheep survived for years post-transfusion with no clinical signs and no disease-associated PrP (PrP^Sc) found in post mortem tissue samples by conventional tests. Using a sensitive protein misfolding cyclic amplification assay (PMCA), we found that the majority of these sheep had detectable PrP^Sc in lymph node samples, at levels approximately 10⁵-10⁶ times lower than in equivalent samples from clinically positive sheep. Further testing revealed the presence of PrP^Sc in other tissues, including brain, but not in blood samples. The results demonstrate that subclinical infection is a frequent outcome of low dose prion infection by a clinically relevant route for humans (blood transfusion). The long term persistence of low levels of infection has important implications for prion disease control and the risks of re-emergent infections in both humans and animals.