NMY-2, TOE-2 and PIG-1 regulate Caenorhabditis elegans asymmetric cell divisions

Asymmetric cell division is an important mechanism that generates cellular diversity during development. Not only do asymmetric cell divisions produce daughter cells of different fates, but many can also produce daughters of different sizes, which we refer to as Daughter Cell Size Asymmetry (DCSA). In Caenorhabditis elegans, apoptotic cells are frequently produced by asymmetric divisions that exhibit DCSA, where the smaller daughter dies. We focus here on the divisions of the Q.a and Q.p neuroblasts, which produce larger surviving cells and smaller apoptotic cells and divide with opposite polarity using both distinct and overlapping mechanisms. Several proteins regulate DCSA in these divisions. Previous studies showed that the PIG-1/MELK and TOE-2 proteins regulate DCSA in both the Q.a and Q.p divisions, and the non-muscle myosin NMY-2 regulates DCSA in the Q.a division but not the Q.p division. In this study, we examined endogenously tagged NMY-2, TOE-2, and PIG-1 reporters and characterized their distribution at the cortex during the Q.a and Q.p divisions. In both divisions, TOE-2 localized toward the side of the dividing cell that produced the smaller daughter, whereas PIG-1 localized toward the side that produced the larger daughter. As previously reported, NMY-2 localized to the side of Q.a that produced the smaller daughter and did not localize asymmetrically in Q.p. We used temperature-sensitive nmy-2 mutants to determine the role of nmy-2 in these divisions and were surprised to find that these mutants only displayed DCSA defects in the Q.p division. We generated double mutant combinations between the nmy-2 mutations and mutations in toe-2 and pig-1. Because previous studies indicate that DCSA defects result in the transformation of cells fated to die into their sister cells, the finding that the nmy-2 mutations did not significantly alter the Q.a and Q.p DCSA defects of toe-2 and pig-1 mutants but did alter the number of daughter cells produced by Q.a and Q.p suggests that nmy-2 plays a role in specifying the fates of the Q.a and Q.p that is independent of its role in DCSA.

Screening women for distress during pregnancy: the impact of including 'Possibly' as a response option

OBJECTIVES

To investigate the impact of including the response option of 'Possibly' in the Distress question on the Matthey Generic Mood Questionnaire (MGMQ) during antenatal emotional health screening in English-speaking women.

BACKGROUND

Some distress screening questions only allow respondents to choose between 'Yes' or 'No' to the presence of distress. The MGMQ, however, allows respondents to chose between 'Yes', 'Possibly', or 'No', which may be preferable if a participant is reluctant to state she definitely feels distressed.

METHOD

In Study 1, women undergoing routine antenatal psychosocial screening were allocated to either completing the MGMQ Distress question with the usual three-option response format of 'Yes, Possibly, No' (N = 960), or just a 'Yes, No' response format (N = 771). The proportion of responses were compared in each group, as were the proportion then screening positive on the MGMQ's Bother question. In Study 2, women (N = 113) attending routine antenatal clinic appointments were asked about their preference between these response formats.

RESULTS

Including 'Possibly' resulted in only a slight increase in the proportion giving a positive response to the Distress question, and then also screening positive on the Bother question. In Study 2, a substantial majority of women (80%) preferred having 'Possibly' in the response options.

CONCLUSION

While the impact of including 'Possibly' is small, it allows for more women to communicate how they are feeling on the full MGMQ. Given the large majority of women preferring having 'Possibly' included, we believe that the Distress Question is enhanced by having this as a response option.

Hard x-ray - optical four-wave mixing using a split-and-delay line

New, hard x-ray free electron lasers (FEL) produce intense femtosecond-to-attosecond pulses at angstrom wavelengths, giving access to the fundamental spatial and temporal scales of matter. These revolutionary light sources open the door to applying the suite of nonlinear, optical spectroscopy methods at hard x-ray photon energies. Nonlinear spectroscopy with hard x-rays can allow for measuring the coherence properties of short wavelength excitations with atomic specificity and for understanding how high energy excitations couple to other degrees of freedom in atomic, molecular or condensed-phase systems. As a step in this direction, here we present hard x-ray, optical four-wave mixing (4WM) measurements done at 9.8 keV at the split-and-delay line at the x-ray correlation spectroscopy (XCS) hutch of the Linac Coherent Light Source (LCLS). In this work, we create an x-ray transient grating (TG) from a pair of crossing x-ray beams and diffract optical laser pulses at 400 nm from the TG. The key technical advance here is being able to independently vary the delays of the x-ray pulses. Measurements were made in 3 different solid samples: bismuth germinate (BGO), zinc oxide (ZnO) and yttrium aluminum garnet (YAG). The resulting phase-matched, 4WM signal is measured in two different ways: by varying the x-ray, x-ray pulse delay which can reveal both material and light source coherence properties and also by varying the optical laser delay with respect to the x-ray TG to study how the x-ray excitation couples to the optical properties. Although no coherent 4WM signal was seen in these measurements, the absence of this signal gives important information on experimental requirements for detecting this in future work. Also, our laser-delay scans, although not a new measurement, were applied to different materials than in past work and reveal new examples x-ray induced lattice dynamics in solids. This work represents a key step towards extending nonlinear optics and time-resolved spectroscopy into the hard x-ray regime.

Pandemic preparedness of diagnostic radiographers during COVID-19: A scoping review

INTRODUCTION

As chest imaging is a tool for detecting coronavirus disease 2019 (COVID-19), diagnostic radiographers are a key component of the frontline workforce. Due to its unforeseen nature, COVID-19 has challenged radiographers' preparedness in combating its effects. Despite its importance, literature specifically investigating radiographers' readiness is limited. However, the documented experiences are prognostic of pandemic preparedness. Hence, this study aimed to map this literature by addressing the question: 'what does the existing literature reveal about the pandemic preparedness of diagnostic radiographers during COVID-19?'.

METHODS

Using Arksey and O'Malley's framework, this scoping review searched for empirical studies in MEDLINE, Embase, Scopus, and CINAHL. Consequently, 970 studies were yielded and underwent processes of deduplication, title and abstract screening, full-text screening, and backward citation searching. Forty-four articles were deemed eligible for data extraction and analysis.

RESULTS

Four themes that reflected pandemic preparedness were extrapolated: infection control and prevention, knowledge and education, clinical workflow, and mental health. Notably, the findings highlighted pronounced trends in adaptation of infection protocols, adequate infection knowledge, and pandemic-related fears. However, inconsistencies in the provision of personal protective equipment, training, and psychological support were revealed.

CONCLUSION

Literature suggests that radiographers are equipped with infection knowledge, but the changing work arrangements and varied availability of training and protective equipment weakens their preparedness. The disparate access to resources facilitated uncertainty, affecting radiographers' mental health.

IMPLICATIONS FOR PRACTICE

By reiterating the current strengths and weaknesses in pandemic preparedness, the findings can guide clinical practice and future research to correct inadequacies in infrastructure, education, and mental health support for radiographers in the current and future disease outbreaks.

Ferricyanide photo-aquation pathway revealed by combined femtosecond Kβ main line and valence-to-core x-ray emission spectroscopy

Reliably identifying short-lived chemical reaction intermediates is crucial to elucidate reaction mechanisms but becomes particularly challenging when multiple transient species occur simultaneously. Here, we report a femtosecond x-ray emission spectroscopy and scattering study of the aqueous ferricyanide photochemistry, utilizing the combined Fe Kβ main and valence-to-core emission lines. Following UV-excitation, we observe a ligand-to-metal charge transfer excited state that decays within 0.5 ps. On this timescale, we also detect a hitherto unobserved short-lived species that we assign to a ferric penta-coordinate intermediate of the photo-aquation reaction. We provide evidence that bond photolysis occurs from reactive metal-centered excited states that are populated through relaxation of the charge transfer excited state. Beyond illuminating the elusive ferricyanide photochemistry, these results show how current limitations of Kβ main line analysis in assigning ultrafast reaction intermediates can be circumvented by simultaneously using the valence-to-core spectral range.

An optimized scheme for detecting magneto-optic effects in ultrathin films with Sagnac interferometry

Sagnac interferometry is advantageous in measuring time-reversal-symmetry breaking effects in ferromagnetic and antiferromagnetic materials as it suppresses time-reversal symmetric birefringent effects that are ubiquitous and often overwhelming in optical detection systems. When its sensitivity is limited only by the amplifier noise in the photo-detector, one needs to optimize the optical power that returns to the detector. We demonstrate an experimental scheme that maximizes the returning optical power in a Sagnac interferometry when detecting the magneto-optic effect in ultrathin films. In this scheme, the optical beam bearing the Faraday effect on a thin film is reflected at a second surface coated with a highly reflective gold film. The gold film increases the returned optical power by a factor of 4-5. For a normal-incidence Sagnac interferometer, this scheme yields an increase in the signal-to-noise ratio by the same factor. For an oblique-incidence Sagnac interferometer, this scheme should yield an increase in the signal-to-noise ratio by a factor of 20-25. For illustration, this scheme is used to measure magnetization curves and Kerr rotation images of 4.5-unit-cell thick SrRuO₃(001) grown on SrTiO₃(001).

OP0190 COMPREHENSIVE GENETIC AND FUNCTIONAL ANALYSES OF Fc GAMMA RECEPTORS EXPLAIN RESPONSE TO RITUXIMAB THERAPY FOR AUTOIMMUNE RHEUMATIC DISEASES

Background

Rituximab is widely used to treat rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) but clinical response varies. Efficacy is determined by the efficiency of depletion, which may depend on a variety of Fc gamma receptor (FcγR)-dependent mechanisms. Previous research was limited by complexity of the FCGR locus, not integrating copy number variation with functional SNP, and small sample size.

Objectives

The study objectives were to assess the effect of the full range of FcγRs variants on depletion, clinical response and functional effect on NK-cell-mediated killing in two rheumatic diseases with a view to personalised B-cell depleting therapies.

Methods

A prospective longitudinal cohort study was conducted in 873 patients [RA=611; SLE=262] from four cohorts (BSRBR-RA and BILAG-BR registries, Leeds RA and Leeds SLE Biologics). For RA, the outcome measures were 3C-DAS28CRP and 2C-DAS28CRP at 6 (+/-3) months post-rituximab (adjusted for baseline DAS28). For SLE, major clinical response (MCR) was defined as improvement of active BILAG-2004 domains to grade C/better at 6 months. B-cell depletion was evaluated by highly-sensitive flow cytometry. Qualitative and quantitative polymorphisms for five major FcγRs were measured using a commercial multiplex ligation-dependent probe amplification. Median NK cell FcγRIIIa expression (CD3-CD56+CD16+) and NK-cell degranulation (CD107a) in the presence of rituximab-coated Daudi/Raji B-cell lines were assessed using flow cytometry.

Results

In RA, for FCGR3A, carriage of V allele (coefficient -0.25 (SE 0.11); p=0.02) and increased copies of V allele (-0.20 (0.09); p=0.02) were associated with greater 2C-DAS28 response. Irrespective of FCGR3A genotype, increased gene copies were associated with a better response. In SLE, 177/262 (67.6%) achieved BILAG response [MCR=34.4%; Partial=33.2%]. MCR was associated with increased copies of FCGR3A-158V allele, OR 1.64 (95% CI 1.12-2.41) and FCGR2C-ORF allele 1.93 (1.09-3.40). Of patients with B-cells data in the combined cohort, 236/413 (57%) achieved complete depletion post-rituximab. Only homozygosity for FCGR3A-158V and increased FCGR3A-158V copy number were associated with increased odds of complete depletion. Patients with complete depletion had higher NK cell FcγRIIIa expression at rituximab initiation than those with incomplete depletion (p=0.04) and this higher expression was associated with improved EULAR response in RA. Moreover, for FCGR3A, degranulation activity was increased in V allele carriers vs FF genotype in the combined cohort; p=0.02.

Conclusion

FcγRIIIa is the major low affinity FcγR and increased copies of the FCGR3A-158V allele, encoding the allotype with a higher affinity for IgG1, was associated with clinical and biological responses to rituximab in two autoimmune diseases. This was supported by functional data on NK cell-mediated cytotoxicity. In SLE, increased copies of the FCGR2C-ORF allele was also associated with improved response. Our findings indicate that enhancing FcγR-effector functions could improve the next generation of CD20-depleting therapies and genotyping could stratify patients for optimal treatment protocols.

References

None

Acknowledgements

This research was funded/supported by the joint funding from the Medical Research Council (MRC) and Versus Arthritis of MATURA (grant codes 36661 and MR/K015346/1). MASTERPLANS was funded by the MRC (grant code MR/M01665X/1). The Leeds Biologics Cohort was part funded by programme grants from Versus Arthritis (grant codes 18475 and 18387), the National Institute for Health Research (NIHR) Leeds Biomedical Research Centre (BRC) and Diagnostic Evaluation Co-operative and the Ann Wilks Charitable Foundation. The BILAG-BR has received funding support from Lupus UK, and unrestricted grants from Roche and GSK.

The functional studies were in part supported through a NIHR/HEFCE Clinical Senior Lectureship and a Versus Arthritis Foundation Fellowship (grant code 19764) to AWM, the Wellcome Trust Institutional Strategic Support Fund to JIR and MYMY (204825/Z/16/Z), NIHR Doctoral Research Fellowship to MYMY (DRF-2014-07-155) and NIHR Clinician Scientist to EMV (CS-2013-13-032). . AWM, INB, JDI and PE were supported by NIHR Senior Investigator awards. Work in JDI’s laboratory is supported by the NIHR Newcastle BRC, the Research Into Inflammatory Arthritis Centre Versus Arthritis, and Rheuma Tolerance for Cure (European Union Innovative Medicines Initiative 2, grant number 777357). INB is funded by the NIHR Manchester BRC.

This article/paper/report presents independent research funded/supported by the NIHR Leeds BRC and the NIHR Guy’s and St Thomas’ BRC. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

Disclosure of Interests

Md Yuzaiful Md Yusof: None declared, James Robinson: None declared, Vinny Davies: None declared, Dawn Wild: None declared, Michael Morgan: None declared, John Taylor: None declared, Yasser El-Sherbiny: None declared, David Morris: None declared, Lu Liu: None declared, Andrew Rawstron: None declared, Maya H Buch: None declared, Darren Plant: None declared, Heather Cordell: None declared, John Isaacs: None declared, Ian N. Bruce: None declared, Paul Emery Speakers bureau: Roche, Consultant of: Roche, Grant/research support from: Roche, Anne Barton: None declared, Timothy Vyse: None declared, Jennifer Barrett: None declared, Edward Vital Consultant of: Roche, Grant/research support from: Roche, Ann Morgan Speakers bureau: Roche/Chugai, Consultant of: GSK, Roche, Chugai, AstraZeneka, Regeneron, Sanofi, Vifor, Grant/research support from: Roche, Kiniksa Pharmaceuticals

Virtual cardiac rehabilitation during the COVID-19 pandemic: a tertiary site experience

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): University of British Columbia Clinician Investigator Program

Background

The COVID-19 pandemic resulted in the abrupt suspension of centre-based cardiac rehabilitation (CR). Multidisciplinary virtual CR (VCR) with the use of digital, telephone, and video communication was implemented for continued care access. Exercise therapy was delivered through synchronous video-supervised sessions, pre-recorded sessions, and self-directed physical activity.

Purpose

To describe patient characteristics, completion rates, and safety outcomes in a real-world VCR population.

Methods

Prospective observational study of a tertiary academic CR program. VCR was implemented at pandemic onset (March 2020). Patients who were enrolled in, and either completed or dropped out, during the study period were included. Completers were defined as completing 6 months of virtual enrolment and an exit assessment. Risk was defined by the AACPVR 2020 risk categorization. Adverse cardiovascular events were defined as a patient-initiated event requiring medical assessment and stratified as exercise or non-exercise related. Continuous variables are presented as means and SD or medians and IQR. Student’s t-test was used for between group comparisons. Categorical variables are presented as n (%) and compared using the χ2 test or Fischer’s exact test. A p-value <0.05 was considered significant.

Results

Between March 13th, 2020, and August 31st, 2021, 222 [mean age 61.8 years (SD, 12.6) 77% male], were enrolled and discharged from the VCR program (Table 1). There were 160 completers and 62 non-completers (completion rate 72%). Among the non-completers 26 attended the MD intake assessment only. The remaining 36 completed a median of 85 days (IQR 25-197). This cohort included 21 (9%) high-risk and 35 (16%) moderate risk patients. Those at moderate risk were more likely to be non-completers and those at low risk were more likely to be completers (Table 1). Two exercise and 17 non-exercise adverse events were observed (median clinical surveillance 217 days [IQR 205-240]) (Table 2). Exercise related adverse events included neurally mediated syncope during a synchronous video exercise session in a low risk patient. This was responded to as per centre developed virtual safety protocols. A second syncope related to heart block occurred in a moderate risk patient during independent physical activity and required permanent pacemaker insertion. Both patients completed the program. Three non-exercise adverse cardiac events resulted in cessation of participation included one death and two heart failure hospitalizations (Table 2). One stroke and 13 emergency department visits for cardiac symptoms occurred in completers.

Conclusion

Real world VCR is feasible, including in those at moderate to high risk. Modest completion rates and a low exercise related adverse event rate were observed. Synchronous video exercise sessions with video monitoring and safety protocols may improve response to adverse exercise related events.

Radionuclide ventriculography phase analysis for risk stratification of patients undergoing cardiotoxic cancer therapy

BACKGROUND

Accurate diagnostic tools to identify patients at risk of cancer therapy-related cardiac dysfunction (CTRCD) are critical. For patients undergoing cardiotoxic cancer therapy, ejection fraction assessment using radionuclide ventriculography (RNVG) is commonly used for serial assessment of left ventricular (LV) function.

METHODS

In this retrospective study, approximate entropy (ApEn), synchrony, entropy, and standard deviation from the phase histogram (phase SD) were investigated as potential early markers of LV dysfunction to predict CTRCD. These phase parameters were calculated from the baseline RNVG phase image for 177 breast cancer patients before commencing cardiotoxic therapy.

RESULTS

Of the 177 patients, 11 had a decline in left ventricular ejection fraction (LVEF) of over 10% to an LVEF below 50% after treatment had commenced. This patient group had a significantly higher ApEn at baseline to those who maintained a normal LVEF throughout treatment. Of the parameters investigated, ApEn was superior for predicting the risk of CTRCD. Combining ApEn with the baseline LVEF further improved the discrimination between the groups.

CONCLUSIONS

The results suggest that RNVG phase analysis using approximate entropy may aid in the detection of sub-clinical LV contraction abnormalities, not detectable by baseline LVEF measurement, predicting a subsequent decline in LVEF.

Prevalence of sacroiliitis among patients referred for hip MR arthrography

OBJECTIVE

To determine the prevalence of sacroiliitis among patients who have been referred for MR arthrography.

MATERIALS AND METHODS

A retrospective search identified 130 consecutive MR arthrograms of the hip performed on a 1.5T Siemens Avanto at our institution from August 2013 to August 2014. Four studies were excluded due to the absence of a coronal short tau inversion recovery sequence of the pelvis, leaving 126 studies for analysis. A musculoskeletal radiology fellow and three attending musculoskeletal radiologists reviewed the images for the presence of bone marrow edema affecting the sacroiliac joints. Only cases of bone marrow edema meeting the Assessment of SpondyloArthritis international Society definition were considered positive. The two-tailed Fisher's exact test was used to compare the prevalence of positive MRI findings among age and gender groups. GraphPad InStat (GraphPad Software) was used for statistical calculations.

RESULTS

Patients less than 40 years of age demonstrated a statistically higher prevalence of positive MRI findings of sacroiliitis when compared to patients older than 40 (p = 0.0082). No difference in prevalence was found between genders. Overall prevalence of MRI signal alteration suggestive of sacroiliitis as defined by the Assessment of SpondyloArthritis international Society was 4.8%. Among the six patients with positive findings, two were subsequently diagnosed with spondyloarthritis.

CONCLUSION

Hip pain may be a presenting symptom of spondyloarthritis and attention should be paid to the sacroiliac joints during screening examinations, particularly in patients less than 40 years of age.

Deep sr-DDL: Deep structurally regularized dynamic dictionary learning to integrate multimodal and dynamic functional connectomics data for multidimensional clinical characterizations

We propose a novel integrated framework that jointly models complementary information from resting-state functional MRI (rs-fMRI) connectivity and diffusion tensor imaging (DTI) tractography to extract biomarkers of brain connectivity predictive of behavior. Our framework couples a generative model of the connectomics data with a deep network that predicts behavioral scores. The generative component is a structurally-regularized Dynamic Dictionary Learning (sr-DDL) model that decomposes the dynamic rs-fMRI correlation matrices into a collection of shared basis networks and time varying subject-specific loadings. We use the DTI tractography to regularize this matrix factorization and learn anatomically informed functional connectivity profiles. The deep component of our framework is an LSTM-ANN block, which uses the temporal evolution of the subject-specific sr-DDL loadings to predict multidimensional clinical characterizations. Our joint optimization strategy collectively estimates the basis networks, the subject-specific time-varying loadings, and the neural network weights. We validate our framework on a dataset of neurotypical individuals from the Human Connectome Project (HCP) database to map to cognition and on a separate multi-score prediction task on individuals diagnosed with Autism Spectrum Disorder (ASD) in a five-fold cross validation setting. Our hybrid model outperforms several state-of-the-art approaches at clinical outcome prediction and learns interpretable multimodal neural signatures of brain organization.

Effect of body mass index on cardiac injury/cardiovascular outcomes in coronavirus disease 2019: a systematic review and meta-analysis

 

Coronavirus disease 2019 has affected millions of people worldwide. Its clinical spectrum ranges from completely asymptomatic to significant respiratory and non-respiratory symptoms leading to critical illness, including death. We aimed to study the effects of body mass index (BMI) on cardiovascular and other critical illness outcomes in these patients in the USA. We conducted a systematic search of three databases for the period of November 2019 to August 2020 and selected 37 studies for analysis. One study showed a non-significant difference in cardiac injury among BMI groups, but there is a paucity of data on cardiovascular outcomes among different BMI groups; hence, meta-analysis was not done for cardiovascular outcomes. Both high BMI and cardiac injury are independent predictors of poor outcomes in these patients. Pooled analysis showed obesity as a significant risk factor for intensive care unit admission (OR=1.547, CI=1.208–1.981, P=0.001) and intubation /mechanical ventilation (OR=1.744, CI=1.363–2.231 P=0.000). Therefore, BMI should be considered an important part of risk stratification, and vaccination should be prioritized for obese patients when it becomes widely available.

Funding Acknowledgement

Type of funding sources: None. Risk of intubation

An online Sexual Health and Rehabilitation eClinic (TrueNTH SHAReClinic) for prostate cancer patients: a feasibility study

Purpose

The primary objective was to determine the feasibility of implementing the TrueNTH SHAReClinic as a pan-Canadian sexual health and rehabilitation intervention for patients treated for localized prostate cancer.

Methods

The feasibility study was designed to evaluate the accessibility and acceptability of the intervention. Participants from five institutions across Canada were enrolled to attend one pre-treatment and five follow-up online clinic visits over 1 year following their prostate cancer (PC) treatment.

Results

Sixty-five patients were enrolled in the intervention. Website analytics revealed that 71% completed the intervention in its entirety, including the educational modules, with an additional 10% completing more than half of the intervention. Five thousand eighty-three views of the educational modules were made along with 654 views of the health library items. Over 1500 messages were exchanged between participants and their sexual health coaches. At 12 months, the intervention received an overall average participant rating of 4.1 out of 5 on a single item satisfaction measure.

Conclusion

Results support the TrueNTH SHAReClinic as highly acceptable to participants as defined by intervention adherence and engagement. The TrueNTH SHAReClinic demonstrated promise for being a feasible and potentially resource-efficient approach to effectively improving the sexual well-being of patients after PC treatment.

Femtosecond quantification of void evolution during rapid material failure

Understanding high-velocity impact, and the subsequent high strain rate material deformation and potential catastrophic failure, is of critical importance across a range of scientific and engineering disciplines that include astrophysics, materials science, and aerospace engineering. The deformation and failure mechanisms are not thoroughly understood, given the challenges of experimentally quantifying material evolution at extremely short time scales. Here, copper foils are rapidly strained via picosecond laser ablation and probed in situ with femtosecond x-ray free electron (XFEL) pulses. Small-angle x-ray scattering (SAXS) monitors the void distribution evolution, while wide-angle scattering (WAXS) simultaneously determines the strain evolution. The ability to quantifiably characterize the nanoscale during high strain rate failure with ultrafast SAXS, complementing WAXS, represents a broadening in the range of science that can be performed with XFEL. It is shown that ultimate failure occurs via void nucleation, growth, and coalescence, and the data agree well with molecular dynamics simulations.

Provider practices for the prevention of eclampsia and attitudes toward magnesium sulfate: results of a nationwide survey

OBJECTIVE

To survey OB-GYNs regarding their practice patterns and perspectives when it comes to using magnesium sulfate (magnesium) in the prevention of eclampsia.

STUDY DESIGN

We conducted a cross-sectional web-based 18-item survey given to 564 practicing OB-GYNs in the Pregnancy-Related Care Research Network. The survey used clinical scenarios to look at provider practices for preventing eclampsia in patients who have preeclampsia and relative contraindications to magnesium. Next, we assessed provider attitudes toward magnesium and inquired about their experiences with complications related to its use. The survey also contained an embedded educational component that addressed the signs and symptoms of magnesium toxicity followed by a 2-item quiz for those providers who self-identified as having never treated magnesium toxicity.

RESULTS

Nearly 30% of OB-GYNs contacted completed the survey. For patients with preeclampsia and a contraindication to magnesium such as myasthenia gravis, 44.4% of respondents would administer an alternative antiepileptic and 42.5% of them would administer no antiepileptic at all. For patients with pulmonary edema complicating preeclampsia, 32.5% would give magnesium at the usual dose, 33.1% would give magnesium at less than the usual dose, 12.3% would give an alternative antiepileptic and 22.1% would give no antiepileptic at all. For patients with laboratory evidence of renal compromise complicating preeclampsia, most respondents (89.6%) said they would give magnesium at less than the usual dose. Regarding complications of magnesium that clinicians have encountered, over one-third of respondents have administered calcium gluconate for magnesium toxicity in patients with preeclampsia. For those providers who have not treated magnesium toxicity and were prompted to receive the educational component and quiz, all knew the correct initial bolus dosing of magnesium and the majority were able to identify symptoms of toxicity. The majority (81.8%) of respondents said that continuous magnesium infusions cause an increased demand for dedicated personnel to care for the patients on them. Almost 57% of respondents endorsed the need for an alternative antiepileptic to magnesium in the prevention of eclampsia. Most write-in responses supporting this need cited a concern with magnesium's safety and side effects.

CONCLUSION

There is wide variation among OB-GYNs regarding the prevention of eclampsia and complications of magnesium are not uncommon. The survey revealed that OB-GYNs are using alternative antiepileptics in scenarios where there is concern for magnesium's safety profile. In addition, over half of those surveyed believe there is a need for validated antiepileptics other than magnesium for the prevention of eclampsia in patients with preeclampsia. These findings suggest that OB-GYNs would support further research into alternative antiepileptics in the prevention of eclampsia.

CAR T cells targeting tumor endothelial marker CLEC14A inhibit tumor growth

Engineering T cells to express chimeric antigen receptors (CARs) specific for antigens on hematological cancers has yielded remarkable clinical responses, but with solid tumors, benefit has been more limited. This may reflect lack of suitable target antigens, immune evasion mechanisms in malignant cells, and/or lack of T cell infiltration into tumors. An alternative approach, to circumvent these problems, is targeting the tumor vasculature rather than the malignant cells directly. CLEC14A is a glycoprotein selectively overexpressed on the vasculature of many solid human cancers and is, therefore, of considerable interest as a target antigen. Here, we generated CARs from 2 CLEC14A-specific antibodies and expressed them in T cells. In vitro studies demonstrated that, when exposed to their target antigen, these engineered T cells proliferate, release IFN-γ, and mediate cytotoxicity. Infusing CAR engineered T cells into healthy mice showed no signs of toxicity, yet these T cells targeted tumor tissue and significantly inhibited tumor growth in 3 mouse models of cancer (Rip-Tag2, mPDAC, and Lewis lung carcinoma). Reduced tumor burden also correlated with significant loss of CLEC14A expression and reduced vascular density within malignant tissues. These data suggest the tumor vasculature can be safely and effectively targeted with CLEC14A-specific CAR T cells, offering a potent and widely applicable therapy for cancer.

T cells expressing a chimeric antigen receptor specific for the tumor vascular marker CLEC14A inhibited tumor growth in three mouse cancer models.

Abstract 875: Next generation clonal neoantigen targeting T cells, generated using the PELEUSTM bioinformatics platform and the VELOSTM manufacturing method show superior reactivity and phenotypic characteristics than classical TIL products

Adoptive transfer of tumor infiltrating lymphocytes (TIL) has generated objective clinical responses in patients with advanced metastatic cancers. Therapeutic exploitation of neoantigens as targets can potentially lead to safer and more effective treatment modalities with reduced toxicities. The Achilles Therapeutics trial NCT03517917 enabled the acquisition of matched tumor specimens and peripheral blood samples from patients undergoing routine surgery and facilitated the development of the proprietary VELOSTM manufacturing process, generating a personalized clonal neoantigen specific T cell product. An in-depth characterization of T cells expanded with the VELOSTM process was performed and compared to a standard TIL product. Samples were obtained from patients with primary NSCLC or metastatic melanoma. TIL were expanded from tumor fragments after dissection in the presence of IL-2. Peptide pools corresponding to the clonal mutations that were identified using the PELEUSTM bioinformatics platform were used to pulse dendritic cells (DC) generated from peripheral blood monocytes from each patient. Clonal neoantigen specific T cells (cNeT) were expanded using the VELOSTM process by co-culture of TIL with the peptide-pulsed autologous DC. As a comparison, TIL were expanded with a rapid expansion protocol (REP-TIL) in the presence of allogeneic feeders, anti-CD3 antibody and high-dose IL-2. Intracellular cytokine staining was performed following rechallenge with individual peptide pools encoding the clonal mutations. Single peptide reactivities were identified using ELISPOT and extended flow cytometric analysis of markers associated with T cell fitness or dysfunction was performed to phenotypically characterize the cNeT, TIL and REP-TIL. Analysis of the immune cell composition showed that cNeT, TIL and REP-TIL have similar CD3+ T cell content (median cNeT 90.2%, TIL 87.3%, REP-TIL 95%, n=6) and are composed of CD4+ and CD8+ T cells (median CD4:CD8 ratio- cNeT 11.1, TIL 2.03 and REP-TIL 4.7, n=6). cNeT showed superior clonal neoantigen specificity compared to TIL or REP-TIL. The proportion of CD3+ T cells responding to clonal neoantigen rechallenge was increased in cNeT (median 24.3%) compared to TIL (median 0.6%) and REP-TIL (median 1.8%) (n=5). The VELOSTM process incorporating the PELEUSTM platform for prediction of clonal neoantigens generates T cell products enriched for clonal neoantigen reactivities and superior phenotypic characteristics compared to conventional TIL. The VELOSTM process is currently being used to manufacture cNeT for two first-in-human studies including NSCLC and melanoma patients (NCT04032847, NCT03997474). Ethical approval: The samples for the study were collected under an ethically approved protocol (NCT03517917).

Citation Format: Eleni Kotsiou, Tie Zheng Hou, Joseph Robinson, Sonal Varsani, Theres Oakes, Pablo D. Becker, Shreenal Patel, Jennine Mootien, Andrew Craig, Jane Robertson, Edward Samuel, James Reading, Lyra Del Rosario, Andrew Haynes, Samra Turajlic, Farah Islam, David Lawrence, Mariam Jamal-Hanjani, Martin Foster, Sergio A. Quezada, Katy Newton. Next generation clonal neoantigen targeting T cells, generated using the PELEUSTM bioinformatics platform and the VELOSTM manufacturing method show superior reactivity and phenotypic characteristics than classical TIL products [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 875.

An evaluation of the tumour endothelial marker CLEC14A as a therapeutic target in solid tumours

Earlier studies identified the transmembrane cell surface C‐type lectin CLEC14A as a putative tumour endothelial marker. For CLEC14A to progress as a vascular target in solid tumours an in‐depth analysis of CLEC14A expression in human healthy and tumour tissue is needed. It is here shown that an analysis of 5332 RNA expression profiles in the public domain confirmed high expression of CLEC14A in tumour compared to healthy human tissue. It is further shown by immunohistochemistry that CLEC14A protein is absent, or expressed at a very low level, in healthy human and primate tissue. In contrast, CLEC14A is expressed on the vasculature of a range of human solid tumours, with particularly high expression in more than half of renal cell carcinomas. Elevated levels of CLEC14A transcripts were identified in some non‐cancer pathologies; such comorbidities may need to be excluded from trials of therapies targeting this marker. It is further shown that, as CLEC14A expression can be induced by the absence of shear stress, it is imperative that freshly collected as opposed to aged or post‐mortem tissue be analysed. We conclude that CLEC14A is a promising target to enable development of novel anti‐cancer therapies for solid tumours.

Evaluation of Two Night–Vision Devices

Night-blind individuals often have restricted visual fields or other visual impairments that limit their ability to travel at night. The study reported here compared two night-vision devices: one wide-angle light and one with a high-intensity beam. It concluded that no one night light is best for all individuals and that depending on the cause of the night blindness, a smaller angle, high-intensity light may be more useful than a wider angle one.

THU0018 GENETIC FACTORS AND RESPONSE TO RITUXIMAB THERAPY IN SLE

Background:

The biologic drug Rituximab (anti-CD20) is used therapeutically in SLE, however the clinical response to the therapy, which is expensive, is quite variable. Factors influencing the efficacy have been challenging to determine. The MRC funded MASTERPLANS consortium has investigated prognostic factors that determine the therapeutic response to biologic therapy in SLE. Genetics has not been studied on a large scale in this context. SLE is a complex clinical phenotype, it is likewise a complex genetic trait, although it has recently been shown that polygenic risk scores do have a relationship to the severity of the disease (1). In addition, genetic risk factors for SLE, coded at the IgG Fc gamma receptor locus, have the potential to influence antibody-dependent cell-mediated cytotoxicity.

Objectives:

To determine whether the genetics influences the clinical outcome of therapy with Rituximab. The study used both genome-wide data in the form of genetic risk scores as well as specific genetic data at a candidate locus, namely the IgG Fc gamma receptor locus

Methods:

Samples from the BILAG Biologics Register (BILAG BR) of individuals treated with Rituximab were subject to genome-wide genotyping with Illumina GSA V2 chip. Genetic risk scores (GRS) were calculated through a weighted risk sum. Genetic variation at the IgG Fc gamma receptor locus is not captured well on genotyping chips and hence common coding and copy number variation was studied using Multiplex Ligation-dependent Probe Amplification (MLPA) and sequencing.

Results:

BILAG-BR samples for SLE part of receiving Rituximab therapy were genotyped on GSA chip, 573 samples passed QC and were used in principal components analysis (PCA), among them, 310 samples both have RTX treatment information and GRS calculated. Examining the population using PCA in the informative samples revealed that the largest distinction, European versus African ancestry did not correlate with Rituximab response. When GRS was determined in the Responders versus the Non-responders there was a weak correlation with those with a higher risk score showing a tendency to be in the responder group (Fig. 1). We also examined variation at the IgG Fc gamma receptor locus, polymorphisms of which are associated with SLE and have been correlated with therapeutic outcome in lymphoma (2). In a subset of the BILAG-BR cohort, we show that carriage of the SLE risk allele atFCGR3A(158F) was enriched in the ‘responder at some point’ group compared to the non-responder group (P=0.03, Chi-square).

Conclusion:

We present preliminary data indicating that genetics at both the genome wide level and at theFCGRlocus show some influence on the outcome of therapy with Rituximab in SLE; more data are required in order to draw firm conclusions.

References:

[1]Reid S et al. High genetic risk score is associated with early disease onset, damage accrual and decreased survival in systemic lupus erythematosus.Ann Rheum Dis.2019 Dec 11. [Epub ahead of print]

[2]Weng WK, Levy R. Two immunoglobulin G fragment C receptor polymorphisms independently predict response to rituximab in patients with follicular lymphoma. J Clin Oncol. 2003;21(21):3940–3947.

Acknowledgments:

King’s and GSTT Biomedical Research Centre and M01665X/1MRC Stratified Medicine grant

Disclosure of Interests:

Lu Liu: None declared, Ariella Amar: None declared, James Robinson: None declared, Ian N. Bruce Grant/research support from: Genzyme Sanofi, GSK, and UCB, Consultant of: Eli Lilly, AstraZeneca, UCB, Iltoo, and Merck Serono, Speakers bureau: UCB, David Morris: None declared, Tim Vyse: None declared

Erratum: Delayed Onset of Nonthermal Melting in Single-Crystal Silicon Pumped with Hard X Rays [Phys. Rev. Lett. 120, 265701 (2018)]

This corrects the article DOI: 10.1103/PhysRevLett.120.265701.

Visual Immunoprecipitate Assay (VIP) for Listeria monocytogenes and Related Listeria Species Detection in Selected Foods: Collaborative Study

Six foods representing a variety of food products were analyzed by the Assurance Listeria polyclonal enzyme immunoassay (EIA) and by either the Bacteriological Analytical Manual or the U.S. Department of Agriculture culture method for detecting Listeria monocytogenes and related Listeria species. Samples of each food type, at each inoculation level, were analyzed simultaneously by both methods. A total of 19 laboratories representing federal government agencies and private industry in the United States and Canada participated. Food types were inoculated with Listeria species including L. monocytogenes, with the exception of 3 lots of green beans, which were naturally contaminated. During this study, 1764 samples and controls were analyzed and confirmed, of which 492 were positive and 947 were negative by both methods. There were 159 samples that were positive by culture method but negative by the EIA and 188 that were negative by culture method but positive by EIA. Twenty-two samples were negative by EIA and by culture method but confirmed positive when Assurance selective enrichment broths were subcultured to selective agar. The Assurance polyclonal EIA for detecting L. monocytogenes and related Listeria species in foods has been adopted first action by AOAC INTERNATIONAL.

Determination of Lead in Wine by Graphite Furnace Atomic Absorption Spectrophotometry: Interlaboratory Study

An interlaboratory study of a graphite furnace atomic absorption spectrophotometry (GFAAS) method for the determination of lead in wine was conducted. Seventeen laboratories from France, United States, and the United Kingdom, using a variety of GFAAS instruments, took part in the study. The method incorporated a novel matrix-matching procedure to minimize matrix effects between standards and samples. Six wine test materials were prepared and sent to participants as 12 blind duplicate or split level samples. There was good agreement between results obtained from participants and target values (24–279 μg/L) obtained with an inductively coupled plasma-mass spectrometry method. The precision of the GFAAS method was well within the range predicted by the Horwitz equation for the 6 test materials analyzed. Repeatability standard deviations ranged from 3 to 17%. Reproducibility standard deviations were in the range of 10 to 30%. The method is recommended for use for official purposes.

Substrate Supporting Disc Method for Confirmed Detection of Total Coliforms and E. coli in all Foods: Collaborative Study

The Coli Complete® substrate supporting disc (SSD) method for simultaneous confirmed total coliform count and Escherichia coli determination in all foods was compared with AOAC most probable number (MPN) methods, 966.23 and 966.24. Twenty-nine laboratories participated in this collaborative study in which 6 food types were analyzed. Four food types, raw ground beef, pork sausage, raw liquid milk, and nut meats, were naturally contaminated with coliform bacteria. Two foods, dry egg and fresh frozen vegetables, were seeded with coliforms. Three food types, ground beef, raw liquid milk, and pork sausage, were naturally contaminated with E. coli. Although pork sausage was naturally contaminated, the level was very low (<10/50 g); therefore, additional E. coli were inoculated into 1 lot of this food type. Three food types, nut meats, dry egg, and fresh frozen vegetables, were inoculated with E. coli. For naturally contaminated samples, duplicate determinations were made on 3 separate lots for each food type. For inoculated samples, low, medium, and high contamination levels plus uninoculated control samples were examined in duplicate. Data were analyzed separately for total coliform bacteria and for E. coli. Mean log MPN counts were determined by the SSD method and the appropriate AOAC MPN method. Results were then analyzed for repeatability, reproducibility, and mean log MPN statistical equivalence. Results were statistically equivalent for all total coliform levels in all food types except frozen vegetable and raw nut meat uninoculated control samples and 1 lot of pork sausage where the SSD method produced statistically significant greater numbers. For the E. coli determinations, results were statistically equivalent across all samples and all levels for each food type. The SSD method has been adopted first action by AOAC International for confirmed detection of total coliforms and E. coli in all foods.

Relative Effectiveness of Selenite Cystine Broth, Tetrathionate Broth, and Rappaport-Vassiliadis Medium for Recovery of Salmonella spp. from Raw Flesh, Highly Contaminated Foods, and Poultry Feed: Collaborative Study

A collaborative study was performed in 18 laboratories to validate use of Rappaport-Vassiliadis (RV) medium in the standard culture method for recovery of Salmonella spp. from raw, highly contaminated foods and poultry feed. RV medium made from its individual ingredients and incubated at 42�C was compared with selenite cystine (SC) broth incubated at 35�C and tetrathionate (TT) broth incubated at 35� and 43�C for effectiveness in recovery of Salmonella spp. Four artificially contaminated foods (oysters, frog legs, mushrooms, and shrimp) and poultry feed and one naturally contaminated food (chicken) were analyzed. The artificially contaminated foods were inoculated with single serovars of Salmonella at target levels of 0.04 colony-forming units (CFU)/g for the low level and 0.4 CFU/g for the high level. For analysis of 1125 test portions, RV medium (42�C) recovered Salmonellairom 409 test portions; TT (43�C), from 368 test portions; TT (35�C), from 310 test portions; and SC (35�C), from 334 test portions. Overall, RV medium was comparable with or better than other selective enrichments for recovery of Salmonella from the foods in this study, except mushrooms. From mushrooms, SC broth (35�C) recovered more positive test portions than did RV medium (42�C) and TT broth (43�C). The method for detection of Salmonella in raw, highly contaminated foods and

Assurance Polyclonal Enzyme Immunoassay for Detection of Listeria monocytogenes and Related Listeria Species in Selected Foods: Collaborative Study

Six foods representing a variety of food products were analyzed by the Assurance Listeria polyclonal enzyme immunoassay (EIA) and by either the Bacteriological Analytical Manual or the U.S. Department of Agriculture culture method for detecting Listeria monocytogenes and related Listeria species. Samples of each food type, at each inoculation level, were analyzed simultaneously by both methods. A total of 19 laboratories representing federal government agencies and private industry in the United States and Canada participated. Food types were inoculated with Listeria species including L. monocytogenes, with the exception of 3 lots of green beans, which were naturally contaminated. During this study, 1764 samples and controls were analyzed and confirmed, of which 492 were positive and 947 were negative by both methods. There were 159 samples that were positive by culture method but negative by the EIA and 188 that were negative by culture method but positive by EIA. Twenty-two samples were negative by EIA and by culture method but confirmed positive when Assurance selective enrichment broths were subcultured to selective agar. The Assurance polyclonal EIA for detecting L. monocytogenes and related Listeria species in foods has been adopted first action by AOAC INTERNATIONAL.

TEM8/ANTXR1-specific CAR T cells mediate toxicity in vivo

Engineering T-cells to express receptors specific for antigens present on tumour tissue is proving a highly effective treatment for some leukaemias. However, extending this to solid tumours requires antigens that can be safely and effectively targeted. TEM8, a marker overexpressed on the vasculature of some solid tumours, has been proposed as one such target. A recent report stated that T-cells engineered to express a TEM8-specific chimeric antigen receptor (CAR), when injected into mouse models of triple negative breast cancer, are both safe and effective in controlling tumour growth. Here we report contrasting data with a panel of TEM8-specific CAR-T-cells including one generated from the same antibody used in the other study. We found that the CAR-T-cells demonstrated clear TEM8-specific cytotoxic and cytokine release responses in vitro, but when injected into healthy C57BL6 and NSG mice they rapidly and selectively disappeared from the circulation and in most cases caused rapid toxicity. Infusing CAR-T-cells into a TEM8-knockout mouse indicated that selective loss of cells from the circulation was due to targeting of TEM8 in healthy tissues. Histological analysis of mice treated with a TEM8-specific CAR revealed evidence of inflammation in the lung and spleen with large collections of infiltrating neutrophils. Therefore our data raise concerns over potential on-target off-tumour toxicity with CARs targeting TEM8 and these should be considered carefully before embarking upon clinical trials with such agents.

P3822Risk prediction for ASCVD in primary prevention patients on statin therapy

Background

Statins are now widely used for the primary prevention of atherosclerotic cardiovascular disease (ASCVD). However, existing risk prediction models were developed primarily on patients not on statins. We developed a novel model to estimate the risk of ASCVD among contemporary patients taking statins.

Methods

Using combined data from 3 large NIH-sponsored cohort studies: Atherosclerosis Risk in Communities, Framingham Offspring Study, and Multi-ethnic Study of Atherosclerosis we examined adults aged 40–79 years without prior ASCVD who were on statin therapy at the baseline exam. A Cox proportional hazards model was used to identify factors associated with a 10-year risk of CV death, MI, or stroke. Age, sex, and race were forced into the model while other potential candidate predictors were retained if statistically significant at the 0.05 level. Interaction terms with age, sex, and race were retained if significant at the 0.01 level. The model was assessed with c-statistic and calibration plots of observed events versus model-based risks after cross-validation and contrasted with the Pooled Cohorts Equations (PCE) recommended by the current U.S. guidelines.

Results

Among 2333 primary prevention patients on statins at baseline, a total of 220 events occurred over a median 8.8 years of follow-up. Most risk factors retained in our final model overlapped with those included in the PCE (age, sex, race, systolic blood pressure [sBP], diabetes, smoking, high-density lipoprotein cholesterol, total cholesterol). Our model also included creatinine clearance, aspirin use, and the interaction between age and sBP. Optimism-corrected discrimination of the new model was marginally higher than PCE: 0.69 (95% CI 0.66–0.72) versus 0.68 (95% CI 0.65–0.72). Cross-validated calibration was superior on our contemporary sample, especially at the higher levels of risk (Figure), where PCE over-estimated risk.

Calibration plots

Conclusion

Accurate estimation of 10-year ASCVD risk among patients currently on statins necessitates recalibration of the current PCE model or application of our algorithm developed specifically for this cohort. This might help avoid over-estimation of risk and reduce the need for unnecessary additional lipid-lowering therapy.

Acknowledgement/Funding

Regeneron Pharmaceuticals

Tspan18 is a novel regulator of the Ca2+ channel Orai1 and von Willebrand factor release in endothelial cells

Ca2+ entry via Orai1 store-operated Ca2+ channels in the plasma membrane is critical to cell function, and Orai1 loss causes severe immunodeficiency and developmental defects. The tetraspanins are a superfamily of transmembrane proteins that interact with specific 'partner proteins' and regulate their trafficking and clustering. The aim of this study was to functionally characterize tetraspanin Tspan18. We show that Tspan18 is expressed by endothelial cells at several-fold higher levels than most other cell types analyzed. Tspan18-knockdown primary human umbilical vein endothelial cells have 55-70% decreased Ca2+ mobilization upon stimulation with the inflammatory mediators thrombin or histamine, similar to Orai1-knockdown. Tspan18 interacts with Orai1, and Orai1 cell surface localization is reduced by 70% in Tspan18-knockdown endothelial cells. Tspan18 overexpression in lymphocyte model cell lines induces 20-fold activation of Ca2+ -responsive nuclear factor of activated T cell (NFAT) signaling, in an Orai1-dependent manner. Tspan18-knockout mice are viable. They lose on average 6-fold more blood in a tail-bleed assay. This is due to Tspan18 deficiency in non-hematopoietic cells, as assessed using chimeric mice. Tspan18-knockout mice have 60% reduced thrombus size in a deep vein thrombosis model, and 50% reduced platelet deposition in the microcirculation following myocardial ischemia-reperfusion injury. Histamine- or thrombin-induced von Willebrand factor release from endothelial cells is reduced by 90% following Tspan18-knockdown, and histamine-induced increase of plasma von Willebrand factor is reduced by 45% in Tspan18-knockout mice. These findings identify Tspan18 as a novel regulator of endothelial cell Orai1/Ca2+ signaling and von Willebrand factor release in response to inflammatory stimuli.

The novel KIR2DL1 allele, KIR2DL1*037, defined in the cell line SPO010 (IHW9036)

The novel KIR2DL1*037 allele discovered and characterised by single molecule real-time (SMRT) DNA sequencing.

KIR2DL1 allele sequence extensions and discovery of 2DL1*0010102 and 2DL1*0010103 alleles by DNA sequencing

Full-length KIR2DL1 allele sequence extensions characterised by single molecule real-time (SMRT) DNA sequencing.