A potential biomarker of radiosensitivity in metastatic hormone sensitive prostate cancer patients treated with combination external beam radiotherapy and radium-223

PURPOSE

The ADRRAD trial reported the safety and feasibility of the combination of external beam radiotherapy and radium-223 in the treatment of de novo bone metastatic prostate. This study aimed to determine if any biomarkers predictive of response to these treatments could be identified.

EXPERIMENTAL DESIGN

30 patients with newly diagnosed bone metastatic hormone sensitive prostate cancer were recruited to the ADRRAD trial. Blood samples were taken pre-treatment, before cycles 2 to 6 of radium-223, and 8 weeks and 6 months after treatment. Mononuclear cells were isolated and DNA damage was assessed at all timepoints.

RESULTS

DNA damage was increased in all patients during treatment, with bigger increases in foci observed in patients who relapsed late compared to those who relapsed early. Increases in DNA damage during the radium-223 only cycles of treatment were specifically related to response in these patients. Analysis of hematology counts also showed bigger decreases in red blood cell and hemoglobin counts in patients who experienced later biochemical relapse.

CONCLUSIONS

While some patients responded to this combination treatment, others relapsed within one year of treatment initiation. This study identifies a biomarker based approach that may be useful in predicting which patients will respond to treatment, by monitoring both increases in DNA damage above baseline levels in circulating lymphocytes and decreases in red blood cell and hemoglobin counts during treatment.

Staff Perceptions on the Effectiveness of GRiP-S, a New Approach to Clinical Supervision Incorporating Safewards: An Interpretive Phenomenological Analysis

This study explored the impact of an innovative approach to clinical supervision for mental health nurses which integrates Safewards, named Group Reflective integrated Practice with Safewards - GRiP-S. Qualitative data was collected through 10 individual semi-structured interviews with nursing staff who had participated within the clinical supervision approach. Interviews provided insights into the nursing staff's perception and experience of the clinical supervision approach. Through interpretive phenomenological analysis six themes emerged (i) illuminating embodied practice of Safewards, (ii) building confidence through empowering connections, (iii) creating a culture of positive change, (iv) identifying internal motivation for and external barriers to supervision engagement, (v) navigating a global pandemic, and (vi) the transformative role of reflection. Findings demonstrated that the GRiP-S approach assisted mental health nurses' adoption of Safewards interventions in practice, while supporting the development of a cohesive staff team. The impact of COVID-19 within the study setting was addressed and nurses identified how the Safewards model assisted in navigating challenges during this time. Findings further supported prior research on the role of the supervisor and supervisee relationship. This study supports the integration of Safewards within reflective clinical supervision for mental health nursing staff to assist in Safewards fidelity and nursing staff personal and professional development.

Simulation CT Features and Radiation Cardiotoxicity in Non-Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

Radiation cardiotoxicity is a significant clinical dilemma in non-small cell lung cancer (NSCLC) radiation therapy (RT). Baseline cardiovascular (CV) status may influence the risk of cardiotoxicity, and may be ascertainable from the appearance of the heart on simulation computed tomography (CT). We examined the association of CT features with incidental heart dose and risk of cardiac events in NSCLC.

MATERIALS/METHODS

Patients treated with curative-intent RT between 2015 and 2020 at a regional center were identified. Clinical notes were interrogated for baseline patient and CV health details, and follow-up CV events. Cardiac events were verified by a cardiologist. A deep learning-based auto-segmentation tool was applied, allowing extraction of a pre-specified list of volume parameters in a programming environment. CAC was graded as none, mild, moderate and severe in patients with a non-contrast scan. The craniocaudal relationship of the PTV and heart (Feng atlas) were annotated.

RESULTS

A total of 478 patients were included, with a median age of 70 and Charlson Index of 5. The median mean heart dose was 6.3 Gy (IQR 2.7-11.4). The median lung V20 was 20.0% (IQR 14.8-27.1). Cardiovascular risk factors were common, with most patients having 2 (39%) or 3 (31%). A history of previous cardiac events was common, including myocardial infarction (14%), arrhythmia (11%) or heart failure (9%). A total of 6.9% and 7.1% patients developed a new atrial arrhythmia (AA) or heart failure (HF) after completing RT. The volume metrics with the highest AUC for AA and HF events were the left atrium (LA) (AUC 0.67, p = 0.0002) and left ventricle:right ventricle (LV:RV) ratio (AUC 0.66, p = 0.0021). Kaplan-Meier analysis for cardiac events dichotomizing at the optimal cut-point for maximum sensitivity and specificity demonstrated significantly different rates for both AA (LA 109cc, HR 3.35, 95% CI 1.64-6.83, p = 0.0009) and HF (LV:RV ratio 1.61, HR 2.37, 95% CI 1.19-4.74, p = 0.0143). Only 2 patients with non-contrast scans developed a myocardial infarction, both had mild CAC. The incidence of pooled cardiac events was not significantly different between patients with no (n = 2/21, 9.5%), mild (n = 10/38, 26.3%), moderate (n = 8/53, 15.1%) and severe (n = 7/24, 29.2%) CAC (p = 0.3916). Where the inferior border of the PTV was above the superior border of the heart, mean heart dose was significantly lower than compared with overlap of levels (1.9 Gy v 9.7 Gy, p<0.0001), and this was true for 3DCRT (n = 139, p<0.001), IMRT (n = 94, p<0.001) and VMAT (n = 145, p<0.001) patients.

CONCLUSION

LA volume and LV:RV volume ratio are predictive for the development of AA and HF respectively. CAC grade did not differentiate patients by risk of cardiac events. Where the craniocaudal level of the PTV doesn't overlap with the level of the heart, the cardiac dose is likely to be very low. Several simulation CT features are associated with cardiac events following treatment for NSCLC and prospective evidence of cardiac risk could enable medical optimization prior to RT.

Patient-Level and Endpoint-Specific Clinico-Dosimetric Analysis of the Cardiac Base as a Mediator of Radiation Cardiotoxicity in Non-Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

Cardiac disease is a dose-limiting toxicity in non-small cell lung cancer (NSCLC) radiation therapy. Radiation dose to the cardiac base is associated with poor overall survival in several clinical studies, but has not been validated in a non-dose escalated cohort, or with individual patient delineations. In this study we examined the impact of cardiac base dose on overall survival (OS) and cardiac events (CEs), and interrogated the relationships of the substructures comprising the heart base with OS and CEs.

MATERIALS/METHODS

Patients with stage I-III NSCLC treated with curative-intent radiation therapy between 2015 and 2020 at a regional cancer center were identified. Clinical notes were examined for baseline patient, tumor and cardiac details, and both cancer and cardiac outcomes. Three cardiologists verified CEs. Cardiac delineations were completed using a validated deep learning-based autosegmentation tool. Cox and Fine and Gray regressions were undertaken for the risk of death and CEs respectively, accounting for pre-specified evidence-based dose metrics and clinically relevant cardiac covariates.

RESULTS

Most patients received 55 Gy/20# (n = 461/478, 96%) without chemotherapy (58%), planned with VMAT (51%) or IMRT (20%). Pre-existing cardiovascular morbidity was common, with 78% having ≥2 risk factors, and 46% having >1 established cardiac disease. The median follow-up was 21.1 months. Dichotomized at the median, higher heart base Dmax was associated with poorer survival on Kaplan-Meier analysis (21.6 months (95% CI 19.3-24.9) versus 29.4 months (95% CI 21.6-36.6), p = 0.021), and remained significant when statistically compared in published multivariate models. In a multivariate analysis for pooled acute CEs, heart base Dmax was associated with CEs (HR 1.75, 95% CI 1.01-1.06, p = 0.04), but this was not the case for individual CEs. Using Fine and Gray models to account for the competing risk of death, left main coronary maximum dose was associated with atrial fibrillation (p = 0.024), proximal right coronary artery V15 (p = 0.023) and mean dose (p = 0.032), and the right atrium mean dose (p = 0.029) were associated with heart failure. No dose-volume metrics were significantly associated with acute coronary syndrome. None of the constituent base substructures dose were significantly associated with death.

CONCLUSION

Dose to the heart base was associated with increased mortality and an increased pooled cardiac event rate. Accounting for endpoint-specific clinical covariates, only select constituent substructures of the heart base were associated with CEs and no substructures were independently associated with survival. Together, these findings are suggestive of possible interplay between the constituent base substructures in their mediation of radiation cardiotoxicity.

First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9  GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36  GeV/c^{2}, rejecting cross sections above 9.2×10^{-48}  cm at the 90% confidence level.

A randomized, double-blind, single-dose study to assess bioequivalence of MB02 biosimilar after manufacturing iteration and reference bevacizumab

To investigate and compare the pharmacokinetic (PK) profiles of MB02 products, before and after optimizing the manufacturing process, and reference bevacizumab to establish bioequivalence between them. In this randomized, double-blind, single dose, parallel study, 114 healthy male volunteers were randomized 1:1:1 to receive a 1 mg/kg intravenous dose of MB02-SP, MB02-DM, or US-bevacizumab. The follow-up period was 100 days. PK similarity between them was determined using the standard bioequivalence criteria (0.80-1.25) for the area under the serum concentration-time curve from time 0 extrapolated to infinity and the maximum observed serum concentration. Study results showed that the PK profiles of bevacizumab were similar. Statistical analysis demonstrated that for each pairwise comparison there were no differences. The 90% CIs for the ratios of geometric least squares means were fully contained within the predefined similarity acceptance limits and ranged from 0.899 to 1.12 for area under the curve and from 0.887 to 1.11 for maximum concentration. A total of 159 adverse events were reported by 76 subjects who received the study drug. The majority (90.6%) of the reported adverse events were grade 1 in severity, with 9.4% as grade 2 in severity. None were considered as grade 3, 4, or 5. Treatment-induced anti-drug antibodies incidence was 21.6%, 33.3%, and 23.7% for the treatment of MB02-SP, MB02-DM, and US-bevacizumab, respectively. No subjects showed treatment-induced neutralizing anti-drug antibodies. This study demonstrates the PK, safety, and immunogenicity similarity and bioequivalence of MB02-SP, MB02-DM, and the reference product bevacizumab.

The risk of subsequent surgery following bowel resection for Crohn's disease in a national cohort of 19 207 patients

AIM

Surgery is required for most patients with Crohn's disease (CD) and further surgery may be necessary if medical treatment fails to control disease activity. The aim of this study was to characterize the risk of, and factors associated with, further surgery following a first resection for Crohn's disease.

METHODS

Hospital Episode Statistics from England were examined to identify patients with CD and a first recorded bowel resection between 2007 and 2016. Multivariable logistic regression was used to examine risk factors for further resectional surgery within 5 years. Prevalence-adjusted surgical rates for index CD surgery over the study period were calculated.

RESULTS

In total, 19 207 patients (median age 39 years, interquartile range 27-53 years; 55% women) with CD underwent a first recorded resection during the study period. 3141 (16%) underwent a further operation during the study period. The median time to further surgery was 2.4 (interquartile range 1.2-4.6) years. 3% of CD patients had further surgery within 1 year, 14% by 5 years and 23% by 10 years. Older age (≥58), index laparoscopic surgery and index elective surgery (adjusted OR 0.65, 95% CI 0.54-0.77; 0.77, 0.67-0.88; and 0.77, 0.69-0.85; respectively) were associated with a reduced risk of further surgery by 5 years. Prior surgery for perianal disease (1.60, 1.37-1.87), an extraintestinal manifestation of CD (1.51, 1.22-1.86) and index surgery in a high-volume centre for CD surgery (1.20, 1.02-1.40) were associated with an increased risk of further surgery by 5 years. A 25% relative and 0.3% absolute reduction in prevalence-adjusted index surgery rates for CD was observed over the study period.

CONCLUSIONS

Further surgery following an index operation is common in CD. This risk was particularly seen in patients with perianal disease, extraintestinal manifestations and those who underwent index surgery in a high-volume centre.

Freshwater Macroalgae, Oedogonium, Grown in Wastewater Reduce Diet-Induced Metabolic Syndrome in Rats

Macroalgae produce compounds with industrial, pharmaceutical and nutritional applications. In this study, biomass from the freshwater macroalgal genus Oedogonium was grown in either treated municipal wastewater (M) or ash dam water from a coal-fired power station (D). The biomass was investigated for its metabolic responses in high-carbohydrate, high-fat diet-fed rats, a model of human metabolic syndrome. The Oedogonium biomass cultured in M contained higher amounts of K, Mg, omega-3 polyunsaturated fatty acids (PUFA), insoluble fibre and β-carotene, while biomass grown in D contained higher amounts of Al, Fe, V, Zn, Mn and As. Biomass from M further increased body weight and inflammation in the heart and colon in high-carbohydrate, high-fat diet-fed rats. In contrast, biomass from D prevented changes in metabolic, cardiovascular and liver parameters without changing tissue histology. We suggest that increased intake of metals and metalloids through macroalgal biomass from D may decrease abdominal fat deposition while polysaccharides, PUFA and carotenoids from M may improve blood glucose responses in an obesogenic diet. Thus, macroalgal biomass grown in different wastewater sources could be acceptable for feed or food applications. This biomass could even provide potential health benefits in diet-induced metabolic syndrome.

POS0481 DEFINING DISTINCT RESIDENT AND MIGRATORY FIBROBLAST POPULATIONS FROM SKIN BIOPSIES IN SYSTEMIC SCLEROSIS

Background

Recent studies using single cell RNA sequencing have delineated distinct subpopulations of fibroblasts in skin and other organs. To improve understanding of functional differences between fibroblast subpopulations, we have developed a novel technique to selectively isolate “migratory” fibroblasts, and non-migratory “resident” fibroblasts from heathy control (HC) and SSc skin.

Objectives

To compare migratory and resident populations of dermal fibroblasts in systemic sclerosis by their differential gene or protein expression, and through functional assays of fibrotic potential.

Methods

Forearm skin punch biopsies were collected from dcSSc(n=3), and healthy control skin(n=3).

Migratory fibroblasts were first isolated by standard explant culture, then the residual biopsy fragments underwent collagenase digestion to yield a population of resident fibroblasts that retained in the biopsy fragments. These populations were further expanded for use at passage 3-6.

Functional characterisation included 3-D collagen gel contraction, and migratory scratch-wound assays. Expression of pro-collagen I (Col1), CTGF and αSMA was compared by western blot. Bulk RNAseq on each fibroblast population was performed. Statistical analysis was carried out using Rsoftware “tidyverse”. Criteria for significant differences in gene expression were a fold change of ≥1.5, and adjusted p-value (FDR) of <0.05

Results

Compared with HC, all SSc fibroblast populations showed a hallmark fibrotic phenotype with increased gel contraction, faster migration, and overexpression of Col1, CTGF and αSMA compared with HC. However, SSc resident fibroblasts showed attenuated contraction, migration, and reduced levels of αSMA compared to migratory SSc fibroblasts. Bulk RNAseq performed on each fibroblast population confirmed 5579 significantly differentially expressed genes between SSc resident and SSc migratory fibroblasts, whereas no genes were significantly differentially expressed between HC resident and migratory fibroblasts.

SSc and HC migratory fibroblasts and resident fibroblasts were then compared, to understand disease-related differences between the two fibroblast populations. 739 genes were significantly overexpressed in the migratory fibroblast population (including ASPM, TRIP3), whereas 745 genes were significantly upregulated in the resident fibroblast population. The genes upregulated in resident fibroblasts included CCL2, CXCL8, and ICAM1.

Many genes typically associated with SSc (such as SERPINE1, COMP), were not significantly different between the SSc fibroblast subpopulations, but were significantly elevated in both SSc subpopulations compared to HC fibroblast populations, suggesting that these reflect a more generic SSc phenotype.

Conclusion

Migratory and resident SSc fibroblast populations exhibit distinct functional and transcriptional differences that are much less apparent for HC biopsies. Further work is required to understand the precise contribution these distinct SSc fibroblast populations in pathogenesis, and how they might be targeted therapeutically. Our findings also highlight that conventional explant culture techniques may ignore important fibroblasts populations and highlight the importance of more detailed analysis such as single cell analysis to better understand pathobiology of SSc.

Table 1.

Table of the most significantly differentially expressed genes with highest fold change and adjusted p-value (FDR) between the migratory and resident SSc fibroblast population

Significantly upregulated genes in SSc migratory fibroblastsSignificantly upregulated genes in SSc resident fibroblastsFold changeAdjusted p valueFold changeAdjusted p valueGPR15.990.01CCL238.66<0.0001PPME14.860.011CXCL824.360.0001KIF20A4.340.015ICAM115.38<0.0001CENPF4.310.018EGR115.190.0002STC24.180.01EGR212.770.0002ASPM3.880.02IFI44L11.50.002TRIB33.600.011CXCL611.43<0.0001HAPLN13.360.039PDGF-D10.140.0003CCNB23.290.025OAS38.940.0009KIF143.240.027IFIT18.580.004

Disclosure of Interests

Kristina Clark: None declared, Alice Cole: None declared, Xu Shiwen: None declared, Voon Ong: None declared, Christopher D Buckley Employee of: founder of Mestag Therapeutics https://mestagtherapeutics.com/, Christopher P Denton: None declared.

Viral load and disease severity in COVID-19

The relationship between COVID-19 severity and viral load is unknown. Our objective was to assess the association between viral load and disease severity in COVID-19. In this single center observational study of adults with laboratory confirmed SARS-CoV-2, the first positive in-hospital nasopharyngeal swab was used to calculate the log10 copies/ml [log10 copy number (CN)] of SARS-CoV-2. Four categories based on level of care and modified sequential organ failure assessment score (mSOFA) at time of swab were determined. Median log10CN was compared between different levels of care and mSOFA quartiles. Median log10CN was compared in patients who did and did not receive influenza vaccine, and the correlation between log10CN and D-dimer was examined. We found that of 396 patients, 54.3% were male, and 25% had no major comorbidity. Hospital mortality was 15.7%. Median mSOFA was 2 (IQR 0-3). Median log10CN was 5.5 (IQR 3.3-8.0). Median log10CN was highest in non-intubated ICU patients [6.4 (IQR 4.4-8.1)] and lowest in intubated ICU patients [3.6 (IQR 2.6-6.9)] (p value < 0.01). In adjusted analyses, this difference remained significant [mean difference 1.16 (95% CI 0.18-2.14)]. There was no significant difference in log10CN between other groups in the remaining pairwise comparisons. There was no association between median log10CN and mSOFA in either unadjusted or adjusted analyses or between median log10CN in patients with and without influenza immunization. There was no correlation between log10CN and D-dimer. We conclude, in our cohort, we did not find a clear association between viral load and disease severity in COVID-19 patients. Though viral load was higher in non-intubated ICU patients than in intubated ICU patients there were no other significant differences in viral load by disease severity.

Touch DNA recovery from unfired and fired cartridges: Comparison of swabbing, tape lifting and soaking

Over the recent few years, several DNA collection techniques and methodologies have been published for the recovery of DNA from fired cartridge cases. In this study, swabbing, the DNA collection technique currently used in our jurisdiction (NSW, Australia), was compared with tape lifting and soaking to assess DNA recovery rates, DNA quality and profile quality. Brass .22LR and 9mmP cartridges were used as they are the most commonly encountered in our jurisdiction. The cartridges (n = 107) were loaded into cleaned firearm magazines by three volunteers of unknown shedder status, to mimic routine casework sample types. Half of the handled cartridges were fired whilst the other half were kept unfired. STR genotypes were produced at both 29 and 30 PCR cycles to evaluate which improved handler allele detection. DNA recovery rates showed that swabbing recovered significantly less DNA than tape lifting and soaking. Whilst there were no significant differences between tape lifting and soaking, tape lifting, on average, yielded more DNA than soaking. The calibre of ammunition had no influence on DNA recovery and in line with expectations, firing was found to decrease DNA recovery for all three sampling techniques. Assessment of DNA quality showed no evidence of PCR inhibition in any of the samples for this study. However, degradation indices showed that most samples were slightly to moderately degraded. Fewer handler alleles were detected from both fired tape lifted and soaked cartridges than unfired cartridges. Whilst 30 amplification cycles allowed for the detection of slightly more handler alleles, no statistically significant differences were found between 29 and 30 PCR cycles. Nonetheless, 50% of the profiles from unfired soaked cartridges that were non-uploadable after 29 cycles were uploadable after 30 cycles. Furthermore, 83% of profiles from unfired cartridges that were tape lifted were uploadable onto our jurisdiction's database at both 29 and 30 PCR cycles. All magazine controls, despite cleaning, contained some level of background DNA. Furthermore, increasing the number of PCR cycles to 30 also increased the detection of non-handler alleles in DNA profiles. Our results suggest tape lifting yields more uploadable profiles from unfired and fired cartridge cases than swabbing but also more adventitious (non-handler) alleles. However additional research will be needed to evaluate the full potential of this method.

Focal Myositis of the Deltoid Muscle: The Role of Magnetic Resonance Imaging for Diagnosis

Introduction:Focal myositis is a rare condition first described by Heffner et al., in 1977, as a self-limiting condition of unknown aetiology. It presents as an inflammatory pseudo tumour in skeletal muscle and can present diagnostic difficulty, being commonly mistaken for tissue of vascular, inflammatory, or neoplastic origin. Diagnosis is traditionally confirmed by muscle biopsy. We present a case where magnetic resonance imaging (MRI) was used to confirm the diagnosis without need for biopsy. Case Presentation: A 19-year year-old female presented with a two2-year history of intermittent swelling of the deltoid associated with pain and tenderness to palpation. . There was no history of trauma or systemic illness. . She was symptomatic with pain, swelling, and tenderness over the left deltoid with no restriction in range of movement of the shoulder or neck. Plain radiographs were normal and MRI magnetic resonance imaging showed diffuse odeamatousedematous signal changes on the proton density weighted sequence within the deltoid muscle and no plexiform neurofibroma. Nerve conduction and electromyography studies were within normal limits excluding an axillary nerve lesion. The patient underwent extensive screening for connective tissue disorders and creatine kinase and lactate dehydrogenase levels were within limits. The patient underwent neuromuscular specialist review confirming that this appeared to be a rare case of focal myositis in the deltoid. . The serial MRI scans confirmed resolution of the condition. Conclusion: Focal myositis of the deltoid is a rare cause of shoulder pain. . We have shown that sequential MRI scanning can obviate the need for muscle biopsy, which has historically been required for diagnostic confirmation. The MRI appearance on the proton density weighted sequence showed diffuse odeamatousedematous signal changes and no plexiform neurofibroma within the deltoid and is a description that has not been previously used for this rare diagnosi

Diabetic Ketoacidosis and Dysregulation of Proglucagon Family of Molecules

Objectives

An increasing body of evidence supports a significant contributory role for pancreatic α-cell dysfunction in the pathophysiology of diabetic ketoacidosis (DKA). In normal physiology, high glucose levels stimulate insulin and inhibit glucagon secretion, while low glucose stimulates glucagon but inhibits insulin release. This regulatory mechanism is progressively lost in diabetes mellitus (DM), where diminished insulin levels are accompanied by hyperglucagonemia leading to the further aggravation of hyperglycemia caused by insulin deficiency. Glucagon is produced via the posttranslational modification of proglucagon in a process that also produces other proglucagon molecules including major proglucagon fragment (MPGF) and glucagon like peptide-1 (GLP-1). Here we hypothesized that DKA is associated with α-cell dysfunction leading to elevated levels of proglucagon molecules.

Methods

We measured levels of glucagon, GLP-1 and MPGF as indices of glucagon synthesis/α-cell function in the plasma of patients with DKA and in healthy controls. The inclusion criteria for DKA patients were glucose &gt; 250 mg/dL, pH &lt; 7.2, bicarbonate &lt; 15mEq/L, presence of ketones and patients were part of a larger randomized trial. Samples were obtained at baseline prior to trial interventions. An independent sample t-test was used to compare differences.

Results

We analyzed samples of 25 healthy controls and 59 individuals with DKA (47 T1DM and 12 T2DM) and found significant increase in glucagon levels in all of the DKA groups (controls 47 pg/mL (36, 67), T1DM 63 (40,135), T2DM 84 (61,105), p = 0.013). The differences were significant in MPGF too (controls 0.5 ng/mL (0.4, 0.8), T1DM 1.1 (0.7, 1.9), T2DM 1.3 (0.9, 2.0), p &lt; 0.001), while differences in GLP-1 between groups did not reach statistical significance. C-peptide levels were significantly diminished in DKA and the levels of glucagon and C-peptide were strongly associated in healthy controls but not in DKA.

Conclusions

Our data indicate that proglucagon family molecules may be actively contributing to the pathogenesis of DKA and may represent a potential site for future therapeutic interventions.

Funding Sources

The parental study of “Thiamine as adjunctive therapy for diabetic ketoacidosis” was supported through a grant from the National Institute of Health.

Targeted and Untargeted Metabolic Profiling to Discover Bioactive Compounds in Seaweeds and Hemp Using Gas and Liquid Chromatography-Mass Spectrometry

Greenhouse gas emissions are a global problem facing the dairy/beef industry. Novel feed additives consisting of seaweeds and hemp containing bioactive compounds are theorized to reduce enteric methane emissions. In this study we aimed to investigate the metabolic profiles of brown, red and green seaweeds and hemp using gas chromatography and liquid chromatography mass spectrometry. We used targeted and untargeted approaches, quantifying known halomethanes and phenolics, as well as identifying potentially novel bioactive compounds with anti-methanogenic properties. The main findings were: (a) Asparagopsis taxiformis contained halomethanes, with high concentrations of bromoform (4200 µg/g DW), six volatile halocarbons were tentatively identified; (b) no halomethanes were detected in the other studied seaweeds nor in hemp; (c) high concentrations of lignans were measured in hemp; (d) a high numbers of sulfated phenolic acids and unidentified sulfuric acid-containing compounds were detected in all seaweeds; (e) flavonoid glucosides and glucuronides were mainly identified in hemp; and (f) the condensed tannin gallocatechin was tentatively identified in Fucus sp. Using the combined metabolomics approach, an overview and in-depth information on secondary metabolites were provided. Halomethanes of Asparagopsis sp. have already been shown to be anti-methanogenic; however, metabolic profiles of seaweeds such as Dictyota and Sargassum have also been shown to contain compounds that may have anti-methanogenic potential.

The risk of later surgery at the anastomotic site following right hemicolectomy for Crohn's disease in a national cohort of 12 230 patients

BACKGROUND

Crohn's disease (CD) has a high-risk of bowel resection and later surgery for recurrent disease. Recent guidelines recommend colonoscopy 6-12 months following surgery to reduce further surgical intervention through medical therapy intensification.

AIMS

To investigate the risk of further surgery at the anastomosis following right hemicolectomy for CD.

METHODS

Hospital Episode Statistics were used to identify patients with CD and a right hemicolectomy between 2007 and 2016. Adherence to post-resection colonoscopy guidance timing and risk of further surgery at the anastomosis were examined. Cox proportional hazards models assessed risk factors for further surgery.

RESULTS

12 230 patients were identified: 45% male; median age 36 (IQR 26-49) years. Median follow-up was 5.9 (IQR 3.6-8.6) years: totalling 74 960 person-years. Median time to further surgery was 2.9 (IQR 1.2-5.3) years. By 5 years 9% and by 10 years 16.9% of those with sufficient follow-up had at least one further surgery involving the anastomotic site. Older, less deprived patients and those whose index surgery took place on an elective admission had a reduced risk of further surgery. The annual number of right hemicolectomies increased over the study from 1063 to 1317, driven by the increasing prevalence of CD. Overall, 78% of patients did not have a colonoscopy, as recommended, within 6-12 months following index resection.

CONCLUSIONS

Further surgery involving the anastomotic site remains common following index right hemicolectomy for CD. Post-surgical colonoscopy was only undertaken in 22% of patients within suggested timeframes. Increased colonoscopy may lead to a reduced need for surgery if early optimisation of medical therapy is undertaken for recurrence.

Animal and translational models of SARS-CoV-2 infection and COVID-19

COVID-19 is causing a major once-in-a-century global pandemic. The scientific and clinical community is in a race to define and develop effective preventions and treatments. The major features of disease are described but clinical trials have been hampered by competing interests, small scale, lack of defined patient cohorts and defined readouts. What is needed now is head-to-head comparison of existing drugs, testing of safety including in the background of predisposing chronic diseases, and the development of new and targeted preventions and treatments. This is most efficiently achieved using representative animal models of primary infection including in the background of chronic disease with validation of findings in primary human cells and tissues. We explore and discuss the diverse animal, cell and tissue models that are being used and developed and collectively recapitulate many critical aspects of disease manifestation in humans to develop and test new preventions and treatments.

Vitamin C levels amongst initial survivors of out of hospital cardiac arrest

INTRODUCTION

Vitamin C deficiency has been described in patients with sepsis. The post-cardiac arrest syndrome shares similarities to sepsis, however vitamin C levels in post-arrest patients have been incompletely characterized. We assessed vitamin C levels in a post-arrest population.

METHODS

This was a retrospective observational study at a tertiary care center. A convenience sample of post-arrest, sepsis, and healthy control patients was selected from prior studies. Vitamin C levels were measured from samples obtained within 6-h of emergency department admission. A subset of cardiac arrest patients had vitamin C levels additionally measured 24-h later.

RESULTS

A total of 84 patients (34 healthy controls, 25 post-arrest, and 25 septic patients) were included. The median baseline vitamin C level in cardiac arrest patients was 0.33 mg/dL (0.05-0.83), as compared to 0.91 mg/dL (0.69-1.48) in the healthy control group (p < 0.01) and 0.28 mg/dL (0.11-0.59) in the septic group (p = 0.36). Vitamin C levels for cardiac arrest patients fell between the two time points, but the change was not statistically significant (median decrease 0.26 mg/dL, p = 0.08).

CONCLUSIONS

Serum vitamin C levels were lower in post-arrest patients compared to controls and were similar to patients with sepsis. Future studies of vitamin C levels and supplementation following cardiac arrest may be warranted.

DNA recovery from unfired and fired cartridge cases: A comparison of swabbing, tape lifting, vacuum filtration, and direct PCR

The ability to recover trace DNA from fired cartridge cases can help establish important leads regarding the handler of the ammunition. Over recent years, several DNA recovery techniques for fired ammunition have been published. Three techniques of significant interest include tape lifting, direct PCR, and vacuum filtration. This study aimed to compare these to the swabbing method currently employed in our jurisdiction. Brass and nickel cartridges of five different calibres were spiked with 20ng of saliva and subject to DNA collection using all four DNA recovery methods. Unfired and fired cartridges were tested to examine the effects of firing. Swabbing recovered a greater quantity of DNA than vacuum filtration while no significant differences were found between swabbing and tape-lifting. The calibre of ammunition had no effect on DNA recovery. Firing significantly reduced DNA yield from nickel cartridges, while unfired brass cartridges returned less DNA than unfired nickel cartridges. PCR inhibition was not observed in any samples, although degradation indices suggested that most samples were slightly or moderately degraded. Analysis of profiles showed that swabbing and tape lifting resulted in greater numbers of alleles from fired nickel and brass cartridges compared to direct PCR. Samples from nickel cartridges were found to have a greater number of uploadable profiles than samples from brass cartridges. In addition, three mixed profiles were obtained from the single source spiked cartridges as well as evidence of pre-existing DNA on uncleaned cartridges and contaminating alleles on cleaned cartridges. Our results suggest that tape-lifting can be a suitable alternative to swabbing, but that caution must be taken when interpreting profiles from fired cartridge cases as small amounts of DNA not associated with the handling of the cartridges may be present.

The frequent user’s decision-making process when contacting urgent and/or emergency services

Background

There is a lack of qualitative research that has been undertaken which has captured the perspective of frequent users to urgent and emergency healthcare services. Previous research has viewed and studied this population largely by using retrospective routine data, which focuses on the patient's demographic, presenting symptom or demand implication. Current research now advocates that these vulnerable and complex individuals are using these services due to their unmet needs or multiple comorbidities. The aim of this research was to explore the patient's decision-making process and their motivations for repeatedly contacting urgent and emergency services.

Methods

Semi-structured interviews were undertaken with a small cohort of six previously identified frequent users to urgent and emergency healthcare services. These participants were recruited into the study by a third sector organisation, due to the vulnerabilities and complexities of these individuals' lifestyles. A framework analysis was used to code and extract relevant themes and concepts from the interviews.

Results

Social prescribing through a named support worker enables navigation and re-engagement into a range of services that benefits this population and reduces their demand upon other services. The support given through social prescribing organisations can counteract the lack of personal support networks and resilience factors that these individuals experience. In addition, individuals who have been re-referred into substance misuse services should be offered alternative engagement programmes, which differ from their initial programme.

Conclusions

Current inequities of outcomes and access to services should be examined, in relation to vulnerable and complex individuals who have reduced support networks and limited resilience factors. Future research should be undertaken regarding the benefits for frequent users of social prescribing to support patient outcomes and re-integration into services.

Key messages

Social prescribing is the link that enables complex and vulnerable frequent users to navigate and re-engage into a range of health and social care services. Examining the inequities faced by frequent users to urgent and emergency healthcare services.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

1173 Reducing Cancellation and Improving the Patient’s Experience Through Quality Improvement Process

Introduction

Sleep study volume in our system has increased by 23% from 2017 to 2019 which makes unfilled sleep beds a significant concern. Cancellation rate impacts our sleep bed access. We hypothesized cancellation can be improved through quality improvement process which could ultimately lead to improve patient satisfaction.

Methods

A multi-disciplinary team was assembled to examine potential contributing factors. Using the Model for Improvement we developed, tested and implemented interventions using tools such as PDSA cycles, process map and a simplified FMEA (Failure Modes and Effects Analysis). A Key Driver Diagram helped guide our journey to improve the cancellation rate. We developed a Parent Advisory Group to help us with ideas to identify how we could improve the cancellation rate.

Results

The cancellation was 21% prior to the implementation of our interventions. To improve these measures, we have implemented several interventions. The content of our sleep study preparation handbook was improved, increased distribution of the education handbook and developed a series of sleep study videos which are available for viewing prior to the study to prepare patients and families. In addition, we standardized our process of reminder calls in the call center and sleep lab by defining roles and responsibilities. This improved our ability to answer questions and identify and mitigate barriers they may have. We implemented transportation assistance to patients who have transportation barriers and created a waitlist protocol to assist families with a preferred date. After 2 years of interventions, the cancellation rate has decreased from 21% to 14.7%. Interestingly, as we improved our cancellation rate, the overall patient satisfaction has been improved from 83% to 88%.

Conclusion

Using the Model for Improvement, we improved education, communication and scheduling processes, which has reduced cancellation rate and consequently improved patient satisfaction.

Support

 

Characterization of a Subset of Patients With Rheumatoid Arthritis for Whom Current Management Strategies are Inadequate

Objective

A subset of patients with seropositive rheumatoid arthritis (RA) do not mount a C‐reactive protein (CRP) response during flares. We hypothesize that these patients are more likely to experience poor clinical care and less likely to respond to traditional therapy. This study questioned whether this presentation was associated with worse disease outcome and distinct immunological features.

Methods

Using Power Doppler ultrasound, 48 RA patients with active synovitis were recruited; 30 had normal (n)CRP (5 mg/L or less) and 18 had high (h)CRP (more than 5 mg/L) levels. All had equivalent disease burden assessed by other clinical and laboratory parameters.

Results

Time to diagnosis and time to first disease‐modifying antirheumatic drug were significantly longer in nCRP compared with hCRP patients (P < 0.05). Significantly more nCRP patients needed escalation to biologics after 2‐year follow‐up (P = 0.01). The inflammatory milieu was also different between the two subgroups. Synergy between inflammatory cytokines observed in hCRP patients was lost in nCRP patients, and nCRP patients had significantly increased regulatory T‐cell (Treg) frequencies that correlated positively with predictors of poor disease outcome. Conversely, hCRP but not nCRP patients demonstrated a significant upregulation of alternative complement pathway factors that correlated negatively with Treg frequency.

Conclusion

Patients with nCRP during flares of RA had an altered immunological profile compared with hCRP patients and experienced diagnostic delays and responded less favorably to conventional treatment.

Toward the improvement of total nitrogen deposition budgets in the United States

Frameworks for limiting ecosystem exposure to excess nutrients and acidity require accurate and complete deposition budgets of reactive nitrogen (Nr). While much progress has been made in developing total Nr deposition budgets for the U.S., current budgets remain limited by key data and knowledge gaps. Analysis of National Atmospheric Deposition Program Total Deposition (NADP/TDep) data illustrates several aspects of current Nr deposition that motivate additional research. Averaged across the continental U.S., dry deposition contributes slightly more (55%) to total deposition than wet deposition and is the dominant process (>90%) over broad areas of the Southwest and other arid regions of the West. Lack of dry deposition measurements imposes a reliance on models, resulting in a much higher degree of uncertainty relative to wet deposition which is routinely measured. As nitrogen oxide (NOx) emissions continue to decline, reduced forms of inorganic nitrogen (NHx = NH3 + NH4+) now contribute >50% of total Nr deposition over large areas of the U.S. Expanded monitoring and additional process-level research are needed to better understand NHx deposition, its contribution to total Nr deposition budgets, and the processes by which reduced N deposits to ecosystems. Urban and suburban areas are hotspots where routine monitoring of oxidized and reduced Nr deposition is needed. Finally, deposition budgets have incomplete information about the speciation of atmospheric nitrogen; monitoring networks do not capture important forms of Nr such as organic nitrogen. Building on these themes, we detail the state of the science of Nr deposition budgets in the U.S. and highlight research priorities to improve deposition budgets in terms of monitoring and flux measurements, leaf- to regional-scale modeling, source apportionment, and characterization of deposition trends and patterns.

Late presentation of spinal cord compression in hereditary multiple exostosis: case reports and review of the literature

INTRODUCTION

Osteochondromas are usually found in the long bones of patients with hereditary multiple exostoses (HME). The spine is reported to be involved in over 50% of cases, but few of these patients are symptomatic as the result of an existing spinal exostosis.

METHODS

We reviewed the current literature in order to find the right approach to patients with HME-complicated spinal exostosis and describe three paediatric patients that were diagnosed late with spinal cord compression due to cervical exostosis.

RESULTS

Our three cases were all late presentations with neurology and unfortunately had minimal improvement of neurology after the lesion was surgically removed. There is general agreement that late presentation of spinal cord injury due to osteochondromas involving the cervical spine may cause severe and irreversible neurological sequelae. Our literature review revealed that there are no clear-cut guidelines to develop more comprehensive screening measures for these patients.

CONCLUSIONS

A high index of suspicion is the most important factor for correct diagnosis and appropriate management. Physicians who treat HME should bear in mind that thorough history taking and a neurological examination at follow up are essential for these patients. Clearer guidelines for the development of more comprehensive screening programmes are essential.

LEVEL OF EVIDENCE

IV.

Treatment of Glenohumeral Subluxation: A Review of the Literature and Considerations for Pediatric Population

OBJECTIVE

The aim of this review was to identify treatment strategies in the research literature to inform all health professionals on best practice strategies when addressing glenohumeral subluxation.

DESIGN

Articles were identified by searching electronic databases. Two reviewers independently appraised the methodological quality of the selected studies. Discrepancies were resolved after corroboration of results.

RESULTS

Research literature pertaining to five major treatment strategies was found (n = 40 peer-reviewed publications), spanning evidence levels I-V. The greatest number of studies concerned neuromuscular electrical stimulation (n = 19), five of which were level I studies, followed by manual preventive strategies, such as slings (n = 20), three of which were level I studies.

CONCLUSIONS

These findings indicate that the most high-quality research supports using neuromuscular electrical stimulation or manual preventive studies, although no studies used direct comparison methods to ascertain relative merits of each type of intervention when compared with others. No evidence suggested that harm was done by using neuromuscular electrical stimulation or manual preventive methods. This literature review suggests that the identified treatment strategies should be considered by clinicians as the treatment of choice for GHS. No literature was identified that reviewed treatment strategies in a pediatric population; however, the authors considerations for treatment in the pediatric population were included.

The Degree of Left Ventricular Hypoplasia Is Associated with Tricuspid Regurgitation Severity in Infants with Hypoplastic Left Heart Syndrome

Tricuspid valve regurgitation (TR) increases adverse outcomes in children with hypoplastic left heart syndrome (HLHS). Changes in tricuspid valve (TV) annulus and leaflet geometry have been described but the underlying causes for TR in HLHS remain uncertain. We aimed to examine the association between left ventricular (LV) size and TR in infants with HLHS as right ventricular (RV)-LV interactions may be important in TR development. Echocardiograms of 50 infants with HLHS were reviewed. LV size, RV function, TR grade, TV annulus z-score, and aortic arch obstruction were examined at birth and 1 year of age (or the latest study post-bidirectional Glenn anastomosis if the patient was < 1 year of age). 24/50 (48%) had severe LV hypoplasia and 26/50 (52%) had mild/moderate LV hypoplasia. At 1 year, 10/24 (42%) with severe LV hypoplasia had moderate/severe TR versus 0/26 in the mild/moderate LV hypoplasia group (p = 0.0002). TR progressed ( ≥ 1 grade) in 14/24(58%) with severe LV hypoplasia versus 5/26 (19%) with mild/moderate LV hypoplasia (p = 0.008). In this cohort, no association was found between the degree of TR and either RV function, TV annular z-score, or arch obstruction; or between the degree of LV hypoplasia and either RV function or TV annular z-score. In infants with HLHS, the severity and progression of TR is associated with the severity of LV hypoplasia. The mechanism for this association needs further exploration but suggests a role for RV-LV interactions in the development of TR.

Astro-ecology? Shifting the interdisciplinary collaboration paradigm

We present a case study whereby ecological research on fallen trees in forest plots was advanced by a collaboration with astronomers working on the vector fields of stars and gas, and we propose a framework by which such novel collaborations can progress.

Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande

A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.