The underwater soundscape of the North Sea

As awareness on the impact of anthropogenic underwater noise on marine life grows, underwater noise measurement programs are needed to determine the current status of marine areas and monitor long-term trends. The Joint Monitoring Programme for Ambient Noise in the North Sea (JOMOPANS) collaborative project was funded by the EU Interreg to collect a unique dataset of underwater noise levels at 19 sites across the North Sea, spanning many different countries and covering the period from 2019 to 2020. The ambient noise from this dataset has been characterised and compared - setting a benchmark for future measurements in the North Sea area. By identifying clusters with similar sound characteristics in three broadband frequency bands (25-160 Hz, 0.2-1.6 kHz, and 2-10 kHz), geographical areas that are similarly affected by sound have been identified. The measured underwater sound levels show a persistent and spatially uniform correlation with wind speed at high frequencies (above 1 kHz) and a correlation with the distance from ships at mid and high frequencies (between 40 Hz and 4 kHz). Correlation with ocean current velocity at low frequencies (up to 200 Hz), which are susceptible to nonacoustic contamination by flow noise, was also evaluated. These correlations were evaluated and simplified linear scaling laws for wind and current speeds were derived. The presented dataset provides a baseline for underwater noise measurements in the North Sea and shows that spatial variability of the dominant sound sources must be considered to predict the impact of noise reduction measures.

Pharmacological and metabolic parameters of [18F]flubrobenguane in clinical imaging populations

BACKGROUND

Cardiac sympathetic nervous system molecular imaging has demonstrated prognostic value. Compared with meta-[11C]hydroxyephedrine, [18F]flubrobenguane (FBBG) facilitates reliable estimation of SNS innervation using similar analytical methods and possesses a more convenient physical half-life. The aim of this study was to evaluate pharmacokinetic and metabolic properties of FBBG in target clinical cohorts.

METHODS

Blood sampling was performed on 20 participants concurrent to FBBG PET imaging (healthy = NORM, non-ischemic cardiomyopathy = NICM, ischemic cardiomyopathy = ICM, post-traumatic stress disorder = PTSD). Image-derived blood time-activity curves were transformed to plasma input functions using cohort-specific corrections for plasma protein binding, plasma-to-whole blood distribution, and metabolism.

RESULTS

The plasma-to-whole blood ratio was 0.78 ± 0.06 for NORM, 0.64 ± 0.06 for PTSD and 0.60 ± 0.14 for (N)ICM after 20 minutes. 22 ± 4% of FBBG was bound to plasma proteins. Metabolism of FBBG in (N)ICM was delayed, with a parent fraction of 0.71 ± 0.05 at 10 minutes post-injection compared to 0.53 ± 0.03 for PTSD/NORM. While there were variations in metabolic rate, metabolite-corrected plasma input functions were similar across all cohorts.

CONCLUSIONS

Rapid plasma clearance of FBBG limits the impact of disease-specific corrections of the blood input function for tracer kinetic modeling.

Magnetic susceptibility changes in the brainstem reflect REM sleep without atonia severity in isolated REM sleep behavior disorder

REM sleep without atonia (RWA) is the hallmark of isolated REM sleep behavior disorder (iRBD) and is caused by neurodegeneration of brainstem structures. Previously, quantitative susceptibility mapping (QSM) was shown to detect microstructural tissue changes in neurodegenerative diseases. The goal of the study was to compare brainstem magnetic susceptibility (MS) in iRBD and controls using the voxel-based QSM approach and to examine the association between brainstem MS and severity of RWA in iRBD. Sixty iRBD patients and 41 healthy controls were included in the study. Phasic, tonic, mixed RWA and SINBAR score was quantified. QSM maps were reconstructed with QSMbox software from a multi-gradient-echo sequence acquired at 3T MRI system and normalized using a custom T1 template. Voxel-based analysis with age and gender as covariates was performed using a two-sample t-test model for between-group comparison and using a linear regression model for association with the RWA parameters. Statistical maps were generated using threshold free cluster enhancement with p-value p < 0.05, corrected for family wise error. Compared to controls, the iRBD group had higher MS in bilateral substantia nigra (SN), red nucleus and the ventral tegmental area. MS positively correlated with iRBD duration in the right pedunculotegmental nucleus and white matter of caudal mesencephalic and pontine tegmentum and with phasic RWA in bilateral SN. QSM was able to detect MS abnormalities in several brainstem structures in iRBD. Association of MS levels in the brainstem with the intensity of RWA suggests that increased iron content in SN is related to RWA severity.

Recommended Implementation of Quantitative Susceptibility Mapping for Clinical Research in The Brain: A Consensus of the ISMRM Electro-Magnetic Tissue Properties Study Group

This article provides recommendations for implementing quantitative susceptibility mapping (QSM) for clinical brain research. It is a consensus of the ISMRM Electro-Magnetic Tissue Properties Study Group. While QSM technical development continues to advance rapidly, the current QSM methods have been demonstrated to be repeatable and reproducible for generating quantitative tissue magnetic susceptibility maps in the brain. However, the many QSM approaches available give rise to the need in the neuroimaging community for guidelines on implementation. This article describes relevant considerations and provides specific implementation recommendations for all steps in QSM data acquisition, processing, analysis, and presentation in scientific publications. We recommend that data be acquired using a monopolar 3D multi-echo GRE sequence, that phase images be saved and exported in DICOM format and unwrapped using an exact unwrapping approach. Multi-echo images should be combined before background removal, and a brain mask created using a brain extraction tool with the incorporation of phase-quality-based masking. Background fields should be removed within the brain mask using a technique based on SHARP or PDF, and the optimization approach to dipole inversion should be employed with a sparsity-based regularization. Susceptibility values should be measured relative to a specified reference, including the common reference region of whole brain as a region of interest in the analysis, and QSM results should be reported with - as a minimum - the acquisition and processing specifications listed in the last section of the article. These recommendations should facilitate clinical QSM research and lead to increased harmonization in data acquisition, analysis, and reporting.

Health workforce perceptions on telehealth augmentation opportunities

BACKGROUND

The availability and use of telehealth to support health care access from a distance has expanded in response to the COVID-19 pandemic. Telehealth services have supported regional and remote health care access for many years and could be augmented to improve health care accessibility, acceptability and overall experiences for both consumers and clinicians. This study aimed to explore health workforce representatives' needs and expectations to move beyond existing telehealth models and plan for the future of virtual care.

METHODS

To inform recommendations for augmentation, semi-structured focus group discussions were held (November-December 2021). Health workforce representatives with experience in health care delivery via telehealth across country Western Australia were approached and invited to join a discussion.

RESULTS

Focus group participants included 53 health workforce representatives, with between two and eight participants per discussion. In total, 12 focus groups were conducted: seven were specific to regions, three with staff in centralised roles, and two with a mixture of participants from regional and central roles. Findings identified four key areas for telehealth augmentation: improvements required to existing service practice and processes; equity and access considerations; health workforce-focussed opportunities; and consumer-focussed opportunities.

CONCLUSIONS

Following the onset of the COVID-19 pandemic and the rapid increase in health services delivered via telehealth modalities, it is timely to explore opportunities to augment pre-existing models of care. Workforce representatives consulted in this study suggested modifications to existing process and practice that would improve the current models of care, and recommendations on ways to improve clinician and consumer experiences with telehealth. Improving experiences with virtual delivery of health care is likely to support continued use and acceptance of this modality in health care delivery.

NeXtQSM-A complete deep learning pipeline for data-consistent Quantitative Susceptibility Mapping trained with hybrid data

Deep learning based Quantitative Susceptibility Mapping (QSM) has shown great potential in recent years, obtaining similar results to established non-learning approaches. Many current deep learning approaches are not data consistent, require in vivo training data or solve the QSM problem in consecutive steps resulting in the propagation of errors. Here we aim to overcome these limitations and developed a framework to solve the QSM processing steps jointly. We developed a new hybrid training data generation method that enables the end-to-end training for solving background field correction and dipole inversion in a data-consistent fashion using a variational network that combines the QSM model term and a learned regularizer. We demonstrate that NeXtQSM overcomes the limitations of previous deep learning methods. NeXtQSM offers a new deep learning based pipeline for computing quantitative susceptibility maps that integrates each processing step into the training and provides results that are robust and fast.

Digital and physical factors influencing an individual's preventive behavior during the COVID-19 pandemic in Taiwan: A perspective based on the S-O-R model

COVID-19 has caused considerable stress to individuals and communities. Daily press briefings on public health during the COVID-19 pandemic have increased individuals' feelings of social pressure. Abrupt changes to a person's immediate environment, such as the changes caused by COVID-19, can substantially affect their mental health and cognitive adjustment. On the basis of the stimulus-organism-response (S-O-R) framework, we examined the effects of digital and physical stimuli related to COVID-19 in Taiwan on individuals' psychological states and preventive behavior, including social distancing and personal hygiene. The data obtained from 498 valid survey questionnaires indicated that digital and physical factors including informativeness, social pressure, and severity exerted direct effects on cognitive assimilation and anxiety, which in turn affected individuals' preventive behavior. Moreover, cognitive assimilation and anxiety had significant mediating effects on the relationships of informativeness, social pressure, and severity with individuals' preventive behavior. The results of this study indicate how digital and physical stimulus factors affect cognitive assimilation and anxiety, which influence preventive behavior during a pandemic.

Liver Disease Among Patients with Psoriasis: The Malaysian Psoriasis Registry

BACKGROUND

Therapeutic options for psoriasis may be limited for patients with concomitant liver disease.

OBJECTIVE

We aim to report the frequency of liver disease among psoriasis patients, describe the clinical features, treatment modalities and quality of life.

METHODS

This was a multi-center cross-sectional study of psoriasis patients notified to the Malaysian Psoriasis Registry (MPR) from January 2007 to December 2018.

RESULTS

Of 21,735 psoriasis patients, 174 (0.8%) had liver disease. The three most common liver diseases were viral hepatitis (62.1%), fatty liver (14.4%) and liver cirrhosis (10.9%). The male-to-female ratio was 3.8:1. Mean age of onset of psoriasis was higher in those with liver disease compared to those without (37.25 ± 13.47 years vs 33.26 ± 16.96 years, p < 0.001). Psoriasis patients with liver disease had a higher rate of dyslipidemia (27.5%vs16.4%, p < 0.001), hypertension (33.9%vs23.7%, p = 0.002), diabetes mellitus (22.4%vs15.9%, p = 0.021) and HIV infection (5.3%vs0.4%, p < 0.001) compared to those without liver disease.They were also more likely to have severe disease (BSA > 10% and/or DLQI > 10) (59.3%vs49.9%, p = 0.027), psoriatic arthropathy (21.1%vs13.0%, p = 0.002), and nail involvement (78.2%vs56.1%, p < 0.001) compared to those without liver disease. The use of phototherapy (8.4%vs2.6%, p < 0.001), acitretin (7.3%vs2.8%, p < 0.001) and cyclosporin (3.0%vs0.7%, p < 0.001) were significantly higher in the group with liver disease. The mean Dermatology Life Quality Index were similar in both groups (9.69 ± 7.20vs9.62 ± 6.75, p = 0.88).

CONCLUSIONS

The frequency of psoriasis patients with liver disease in MPR was 0.8%. Psoriasis patients with liver disease were more likely to be male, had a higher rate of co-morbidities, severe disease, nail and joint involvement than those without liver disease.

Intraoperative and early postoperative complications of reverse shoulder arthroplasty: A current concepts review

Background

Reverse shoulder arthroplasty is a common procedure performed for a variety of shoulder pathologies.

Aims and objectives

This current concept review evaluates the intraoperative and early postoperative complications, with a specific focus given to neurological and vascular injury, fracture, dislocation and venous thromboembolism.

Conclusion

A detailed knowledge of potential complications will allow surgeons to mitigate risk and maximise outcomes.

Phase-based masking for quantitative susceptibility mapping of the human brain at 9.4T

PURPOSE

To develop improved tissue masks for QSM.

METHODS

Masks including voxels at the brain surface were automatically generated from the magnitude alone (MM) or combined with test functions from the first (PG) or second (PB) derivative of the sign of the wrapped phase. Phase images at 3T and 9.4T were simulated at different TEs and used to generate a mask, PItoh , with between-voxel phase differences less than π. MM, PG, and PB were compared with PItoh . QSM were generated from 3D multi-echo gradient-echo data acquired at 9.4T (21 subjects aged: 20-56y), and from the QSM2016 challenge 3T data using different masks, unwrapping, background removal, and dipole inversion algorithms. QSM contrast was quantified using age-based iron concentrations.

RESULTS

Close to air cavities, phase wraps became denser with increasing field and echo time, yielding increased values of the test functions. Compared with PItoh , PB had the highest Dice coefficient, while PG had the lowest and MM the highest percentage of voxels outside PItoh. Artifacts observed in QSM at 9.4T with MM were mitigated by stronger background filters but yielded a reduced QSM contrast. With PB, QSM contrast was greater and artifacts diminished. Similar results were obtained with challenge data, evidencing larger effects of mask close to air cavities.

CONCLUSION

Automatic, phase-based masking founded on the second derivative of the sign of the wrapped phase, including cortical voxels at the brain surface, was able to mitigate artifacts and restore QSM contrast across cortical and subcortical brain regions.

332 THE PATIENT EXPERIENCE OF THE OLDER PERSONS REHAB AT HOME (OPRAH) SERVICE

Background

The Older Persons Rehab at Home (OPRAH) team is a novel service developed to provide patients with intensive domiciliary based therapy to regain function, mobility and social care goals. This provides rehabilitation in the patients’ own home and accelerates discharge from the acute care sector. In this study patient and carer experiences of the service were explored.

Methods

Patients were sent a postal questionnaire after discharge from the service to collect information on the patient experience of the OPRAH service. The following measures were collected: satisfaction with the service, experience of interacting with therapy staff, involvement in shared goal setting and achievement of rehabilitation goals. Data from participants who responded to feedback questionnaires from the first 12 months of the service were analysed using descriptive statistics.

Results

Ninety-five participants were sent feedback questionnaires with 31 responses received (33%). 96% of participants reported that they were satisfied with the service, with the same proportion expressing that they both felt they were treated with respect and dignity and that they had confidence and trust in the staff. All respondents felt that they could understand the answers to any questions they had while receiving rehabilitation and 92% of participants understood their rehabilitation goals, with 88% of participants feeling they achieved their rehabilitation goals. 88% of participants felt they were adequately involved in their care planning with 83% of participants feeling their family members had ample opportunity to ask questions during their rehabilitation experience. Results did not different by age group of patient or by time with the service.

Conclusion

In this structured evaluation of the OPRAH team participants highly rated the service. Our results highlight that this integrated approach to care allowed patients to be involved in shared goal setting with the majority of patients satisfied that they achieved their goals.

311 FROM ONE FRONT DOOR TO ANOTHER: OUTCOMES OF PATIENTS DIRECTLY DISCHARGED FROM THE FRAILTY AT THE FRONT DOOR SERVICE

Background

The Frailty at the Front Door service is a novel service that provides comprehensive geriatric assessment in the emergency department for older adults who have an unplanned emergency presentation to hospital. It is important to monitor outcomes of patients discharged by the service to ensure appropriate patient selection.

Methods

Patients over the age of 75 with a Manchester Triage Score of between three and five and a possible frailty syndrome are eligible for review by the service. After initial review patients are either discharged directly or recommended for admission. We reviewed the outcomes of patients who were discharged directly after Emergency Department (ED) assessment by the service.

Results

Discharge disposition was available for review in 413 (95%) of patients since initiation of the service in October 2021. 30% (n= 122) of patients were discharged directly after initial ED review. Elevated 4AT score (p = 0.002) but not frailty (p = 0.80) was associated with decreased chances of direct discharge. Of patients discharged directly from ED 13% were reviewed post discharge by the community integrated care team (GICOP), with 43% of these reviews taking place within 30 days. Overall, 16% of patients discharged directly represented to ED within 30 days. There was a trend towards lower rates of representation to ED among patients who were seen by GICOP after discharge from ED (p = 0.12).

Conclusion

There was a high rate of direct discharge after review by the service, with low rates of representation to hospital. While limited by low numbers there was a trend towards lower representation rates in patients reviewed post-discharge by the integrated care team. Future quality improvement initiatives will aim to improve the integration between the services and highlighting patients who would benefit from more timely reviews.

225 OLDER PERSONS REHAB AT HOME (OPRAH) INDICATES AN EFFECTIVE ALTERNATIVE PATHWAY TO INPATIENT REHABILITATION

Background

Older adults have longer hospital stays, higher incidence of nosocomial complications and higher readmissions rates. Older persons rehabilitation at home (OPRaH) is a novel service developed to provide patients with intensive domiciliary based therapy to regain function, mobility and social care goals. OPRaH offers a comprehensive geriatric and interdisciplinary approach. The model enables a safe and accelerated discharge from acute care to home.

Methods

Patients are identified and screened by a team coordinator. On Discharge to OPRaH the following measures were collected; basic demographics, referral source, clinical frailty score and Functional Independence Measures (FIM). Outcomes evaluated are the FIM change, readmission rates, length of inpatient stay savings and time on the service. Data from the first year of operation was analysed using descriptive statistics.

Results

109 patients have undergone rehabilitation with the service with a median age of 82 years (63-103 range). Over two thirds (68%) were classified as frail, with 44% living alone. An injurious fall was the most common reason for index hospitalisation (50%). Referral source was inpatient acute medical team in 50% of cases, with 21% from acute geriatrics , 13 % ortho geriatrics, 13% surgical. Average functional independence measure scores improved from 89 to 102 (p = 0.007). There was no difference in the magnitude of improvement by frailty status (13 vs 14, p = 0.85). The average length of stay saving was 7 days per case, with a total of 757 days saved in one year. Readmission rate within 30 days was 9.3 %. Participants highly rated the service through structured evaluation.

Conclusion

This novel service provides a valuable intervention to a wide case-mix of older adults with evidence of improvements in formal markers of functional impairment after intervention. Referral was based on definable rehabilitation goals and not just on frailty status, age, or gender.

342 THE DISCRIMINATORY VALUE OF ANP-LED CGA ON PATIENT REPORTED SYMPTOMS AND IMPACT ON CARERS: A CROSS-SECTIONAL STUDY

Background

Comprehensive Geriatric Assessment (CGA) is a cornerstone in geriatric care. Objective findings from CGA may differ to patient and carer reported symptoms. This study compared patient reported symptoms with objective metrics collected during CGA and explored the relationship with carer burnout.

Methods

Cross-sectional study of patients attending an Advanced Nurse Practitioner (ANP)-led integrated care clinic. Patient-reported geriatric syndromes included low mood, memory concerns, incontinence, falls or dizziness. CGA metrics collected included Barthel Index, Lawton IADLs, MOCA scores, Geriatric depression scale scores, Rockwood Clinical Frailty Scale (CFS) scores and presence or absence of carer burnout. Descriptive statistics were used to compare the relationship between these variables and logistic regression explored the magnitude of association with carer burnout.

Results

We reviewed 99 CGAs over three months. Median age was 81 (IQR 75–86) with 62% female. Cognitive impairment was present in 96% of patients. Self-reported memory trouble was associated with lower MOCA scores (9 vs 23, p &lt; 0.001) and the presence of dizziness was associated with an increased prevalence of falls (89% vs 24%, &lt; 0.001). The presence of incontinence and functional dependency on IADL were both associated with carer strain and a larger magnitude of association with carer strain was seen with increasing frailty (OR 13.7, 95% CI 3.8-58.8 for moderate to severe frailty) than moderate to severe cognitive impairment (OR 8, 95% CI 3.0–24.1)

Conclusion

Older people reported a wide range of symptoms often subtle, some of which are unmasked during CGA. The resultant frailty syndromes often represent increasing degrees of functional impairment impacting on patient and carer quality of life. Striking the balance between patient reported symptoms and objective measurement is important to allow individualised care pathways to be developed as well as highlighting patients at risk of functional and cognitive decline.

355 PREDICTORS OF HOME SUPPORT SERVICES AND THE CONSEQUENCES OF MISMATCH BETWEEN ALLOCATED AND RECEIVED SERVICES IN COGNITIVELY-IMPAIRED OLDER ADULTS

Background

Home support services aim to support older people to remain at home. Despite substantial investment in home support hours (€600 million), this has not translated into increased carers on the ground for older people. We aimed to report patterns of home support service utilisation in older patients with memory problems, and identify any mis-matches between allocated and received hours, and the impact on patients and caregivers.

Methods

Retrospective analysis of consecutive patients referred to community geriatric clinic from January 2021 to May 2022. 95/104 patients who were identified were suitable for inclusion.

Results

Participants had a median age of 82 (IQR 78-86) of whom 57% were female (n=54). 80% (n=76) were frail (CFS ≥4), with 82% dependent for IADLs (Lawton-Brody IADL Scale ≤6). Median MOCA score was 18, with 44% having moderate to severe cognitive impairment (MOCA ≤17). 40% of patients lived with alone (n=38). 52% (n=49) received formal home supports while 80% (n=76) had an informal carer. 37% (n=18) had a mismatch between hours allocated and hours received. There was a significant difference between median hours of care allocated (7) and median hours of care received (5), p &lt;0.001. Increasing age and frailty, worsening cognitive and functional impairment and living status (living alone) predicted allocation of home supports. Patients who lived with family members were 3 times more likely not to receive allocated hours (OR 3.84 (95% CI 1.2–13.7))

Conclusion

In this vulnerable population with cognitive and functional decline, just over half received formal home support hours. A large proportion experienced significant mismatch between allocated and received hours. Family and informal caregivers often have to fill gaps, adding to existing carer strain. Future models of home support should prioritise early intervention for people with IADL loss to remain independent at home and broaden of the scope of practice of carers to facilitate this.

Drowning in antibiotics

INTRODUCTION

The National Confidential Enquiry into Perioperative Deaths (NCEPOD) report recommended that 'fluid prescribing be given the same value as drug prescribing', yet fluid prescription is commonly delegated to junior doctors despite being a notoriously challenging topic. When antibiotics are given as an infusion they are diluted in 100ml of fluid, which is often unaccounted for when thinking about a patient's fluid requirements. This closed-loop audit aimed to assess first, intravenous (IV) fluid therapy and second, electrolyte prescribing compliance with National Institute for Health and Care Excellence (NICE) guidelines, with and without the additional fluid given with antibiotic administration.

METHODS

Two retrospective audits were performed. Total fluid and electrolyte volume received with and without antibiotic fluids was correlated with recommendations in the NICE guidelines. Between cycles 1 and 2, potassium chloride with sodium chloride and glucose (PSG) was introduced as an alternative to IV maintenance fluid, and bolusing of antibiotics was mandatory.

RESULTS

When analysing total fluid volume input per day, 10.4% and 7.45% of patients met their fluid requirement accurately in the first and second cycles, respectively. Within cycle 1, the mean total additional fluid that was given over 3 days with antibiotics was 1,572.73ml. In cycle 2, this decreased to 469.44ml when antibiotics were given as a bolus.

CONCLUSIONS

In this closed-loop audit we noted that patients receiving IV fluids and IV antibiotics received too much additional fluid when the antibiotic dilution fluid was taken into account. Additional fluid was reduced alongside the proportion of electrolyte complications when bolusing of antibiotics was introduced. We recommend that that all nurses are trained to give antibiotics as a bolus because it can help to reduce fluid-related complications.

IMMU-12. Exploring and modulating the tumour immune microenvironment to facilitate the selection of immunotherapies for paediatric-type diffuse high-grade glioma

Immune cells have the potential to selectively eradicate high-risk brain tumours such as paediatric-type diffuse high-grade glioma (PDHGG). We aim to characterize the tumour immune microenvironment (TIME) of intra-cranial syngeneic mouse models of diffuse hemispheric glioma, H3G34 (DHG-H3G34) and diffuse midline glioma, H3K27 (DMG-H3K27). We also demonstrate how an oncolytic reovirus (Reolysin) can “heat-up” the TIME of our syngeneic models. Orthotopic immunocompetent mouse models of DHG-H3G34 (C57BL/6, NRASG12V + shp53 + shATRX +/- H3.3G34R) and DMG-H3K27 (Nestin-Tv-a/p53fl/fl, RCAS-ACVR1R206H + RCAS-H3.1K27M) were profiled using single-cell RNA-sequencing (scRNA-seq) (10x genomics), a 22-colour custom flow cytometry immune panel and spatial transcriptomics. Differential marker expression was validated with immunohistochemistry and immunofluorescence in tissue sections. Syngeneic mouse tumours treated systemically with Reolysin were also profiled to evaluate the effects of the oncolytic virus on the TIME. Cell type predictions in scRNA-seq using singleR, ssGSEA and expression of individual marker genes suggested that the predominant immune cell types within hemispheric tumours were monocytes (11-21%) and macrophages (10-19%) with much smaller proportions of CD4+ and CD8+ T-cells (4-10%). By contrast, much smaller proportions of monocytes (2%) and macrophages (3%) were observed in the H3.1K27M pontine model. Flow cytometry, immunohistochemistry and immunofluorescence validated scRNA-seq immune profiles and characterised signalling of the PD-1/PD-L1 checkpoint pathway. Spatial transcriptomics allowed immune cell populations to be positioned within tumour sections and showed significant co-localization of CD4+ and CD8+ lymphocytes at tumour margins. Treatment of syngeneic mouse tumours with Reolysin resulted in reduced tumour volumes and altered the TIME, in particular increasing cytotoxic T-cell tumour infiltration. Our results highlight immunological heterogeneity within molecular subgroups of PDHGG and demonstrate ability of a systemically delivered oncolytic virus, Reolysin, to “heat-up” the TIME, contributing to a more immune actionable profile. Future work will help to identify optimal combinations for the next generation of immunotherapies in PDHGG.

HGG-42. Evolutionary selection of key oncogenic alterations in patient-derived models of paediatric diffuse high grade glioma (PDHGG) subtypesin vitro andin vivo

PDHGG are a diverse group of childhood brain tumours comprising multiple subgroups carrying distinct molecular drivers. Patient-derived models accurately recapitulating this underlying biology are critical for mechanistic/preclinical studies aimed at improving patient outcome, however their behaviour over time in the environments in which they are propagated, and how this relates to the human disease, is largely unknown. To explore this, we collected 94 models of PDHGG established as 2D/3D stem cell cultures in vitro, and generated patient-derived xenografts (PDX) in 33/62 specimens implanted orthotopically in vivo. We carried out exome/targeted sequencing, methylation profiling and RNAseq to profile cells through their first 25 passages in culture, and sequential implantation from p0-p2 in mice. In 15/83 cultures, we observed enrichment of gene expression signatures of non-malignant cells over the first 5 passages, with concurrent depletion of somatic mutations/CNAs, excluding them from further study. Validated models retained tumour-matched genotypes, CNAs and driver alterations including H3.3G34R, H3.3/H3.1K27M, BRAF and ACVR1 over time, however subclonal alterations underwent selection in culture which profoundly altered their response to targeted drug treatment. In 6/7 PDGFRA-mutant models, activating mutations were selected against between p5-20 in 2D and/or 3D, whilst MAPK pathway mutations in NF1/PIK3R1 similarly diverged over 15 passages under different growth conditions, resulting in isogenic models with differential signalling, in vivo tumorigenicity, and in vitro sensitivity to multiple MEK inhibitors. In PDXs, serial xenografting reduced the time to tumour formation by up to half, with a concomitant shift in clonal architecture. Multi-region sequencing of diffusely-infiltrating tumours showed selection for alterations such as PIK3CA/NF1 at distant sites, with evidence for convergent evolution of subclonal mutations, as in human tumours. Understanding the evolutionary dynamics of targetable/predictive alterations in PDHGG model systems is key to developing new and effective therapeutic interventions in this highly heterogenous disease.

IMG-09. Characterisation of a panel ofin vivo models of paediatric-type diffuse high-grade glioma (PDHGG) using magnetic resonance imaging

Novel therapies for paediatric-type diffuse high-grade glioma (PDHGG) are urgently required. Orthotopic models using patient-derived material are invaluable tools in preclinical drug development as they retain key genetic/epigenetic features, eg. histone H3G34 or H3K27 alterations. Their evaluation in situ is vital and requires sensitive imaging techniques such as MRI. 12 diffuse hemispheric glioma (DHG; 2 DHG-G34) and 21 diffuse midline glioma (DMG; 17 DMG-K27M) tumours have been characterised using MRI following site-specific orthotopic implantation of patient-derived cells directly from tumour material or after minimal expansion as stem cell cultures. Of the 62 models implanted; 3 DHG and 10 DMG samples were not tumourigenic and 13 DHG/3 DMG models are currently under MRI surveillance. Tumours identified on T2-weighted (T2w)-images varied from a diffuse hyperintense signal to well-defined high contrast masses. Tumour growth in 5 DMG models was too diffuse for longitudinal monitoring with T2w-MRI. Once established, diffusion-weighted, T1/T2 mapping and contrast-enhanced MRI were used to further assess tumour phenotype. Quantitative data from 15 DMG models demonstrated higher water diffusivity and T2 than 10 DHG tumours, which suggests less tightly packed tumour cells but may also reflect the closer proximity of tumours growing in the thalamus/pons/cerebellum to the ventricular system. Lack of contrast-agent enhancement in 11 DMG and 6/10 DHG models indicated an intact blood-brain barrier (BBB), with heterogeneous disruption observed in 4 DHGs; H3-G34 had no bearing on BBB integrity. Upon serial re-implantation survival was shortened in 3/4 DHG and 2/6 DMG models, while quantitative MRI parameters remained similar. Likewise, when 2 DHG and 2 DMG models grown in 2D/3D in vitro were implanted in parallel, poorer survival/improved penetrance was associated with 3D-cultured cells with no difference in imaging phenotype. The study highlights the potential of non-invasive MRI to accurately evaluate the efficacy of novel therapeutics in these PDHGG models.

Circulating extracellular vesicles correlate with nocturnal blood pressure and vascular organ damage and may serve as an integrative biomarker of vascular health

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Council on Science and Technology, Mexico (CONACYT).

Background

 Elevated blood pressure (BP) has been associated with increased levels of circulating extracellular vesicles (EVs) which could potentially serve as a novel integrative biomarker for vascular health.

Purpose

  The present study therefore aimed to assess the relationship between increased EV release, blood pressure and macrovascular organ damage.

Methods

A total of 83 patients with BP ranging from normal to high were included in the present analysis. Extracellular vesicles were evaluated by flow cytometry (CD41+/Annexin v+). BP evaluation included unobserved automated office BP (AOBP) and ambulatory BP monitoring (24hr-BP, day-BP and night-BP). Carotid-femoral pulse wave velocity (PWV) was measured by the SphygmoCor XCEL as a marker of macrovascular organ damage.

Results

Hypertensive patients (n = 73, BP 132.9 ± 17.4/79.4 ± 14.0) compared to normotensive patients (n = 10, BP 113.4 ± 10.4/71.3 ± 9.6) had higher levels of EVs (10.6 ± 8.2 vs 6.5 ± 4.5 EV/µL; p = 0.02). Circulating EVs were positively correlated with nocturnal systolic BP (r= 0.3; p = 0.01) and night-time dipping (r= -0.26; p = 0.02) in univariable analysis. In contrast, systolic AOBP, 24hr-BP and day-BP did not show significant associations. No significant correlations were found with diastolic BP. EVs were significantly correlated with PWV (r = 0.26 p = 0.02).While all BP measures were associated with PWV, average systolic night-time BP demonstrated the strongest correlation with PWV (r = 0.55; p &lt; 0.001) compared to systolic AOBP (r = 0.51; p &lt; 0.001), 24hr-BP (r = 0.46; p &lt; 0.001), and average day-BP (r = 0.48; p &lt; 0.001). Multivariable regression models confirmed  robustness of the models.

Conclusion

We demonstrate a close positive relationship between a variety of BP measures and levels of circulating EVs as well as macrovascular damage assessed by PWV. The strongest correlation with EVs was found for average systolic nocturnal BP. Given that average nocturnal BP is the strongest predictor of CV events, EVs may serve as a useful integrative marker of vascular health and useful biomarker for CV risk assessment, a proposition that will need to be tested in prospective clinical trials. Abstract Figure.

Time to re-envisage integrity among nurse leaders

AIM

This paper highlights integrity as a central tenet in the journey of ethical leadership among nurse leaders, and dialogue as a way of working within integrity.

BACKGROUND

Nurse leaders play a critical role in ensuring ethically sound, safe patient care by supporting staff and fostering positive working environments. Although there is an abundance of literature on leadership, no universally accepted leadership theory exists. Hence, it can be difficult to apply leadership theory and principals to real-life clinical practice.

EVALUATION

From the literature, it is evident that integrity is a crucial aspect of leadership. This paper proposes suggestions for nurturing integrity and fostering open and honest dialogue.

KEY ISSUES

Globally, public health care is complex and evolving and effective nursing leadership is paramount to meet public health needs and support healthcare systems.

CONCLUSION

This paper explores integrity with leadership, re-envisaging personal and professional integrity as a portal to authentic leadership, which has human relationships and dialogue at its core.

IMPLICATIONS FOR NURSING MANAGEMENT

Nurse leaders need support in guiding the nursing profession and promoting ethically sound patient care. The true nature of leadership is dialogue and nurturing a culture of listening and openness at different levels within an organisation is crucial.

90 IMPACT OF AN INTEGRATED CARE MODEL FOR OLDER PERSONS: EVALUATING A PILOT PROGRAMME

Background

In September 2019 Sláintecare helped establish an Integrated Care team for Older People. The aim of this service was to provide a Comprehensive Geriatric Assessment (CGA) to older people within a community network. Service user experience/feedback are critically important for development of a team and a service. To give service users a platform to evaluate the service a patient experience survey was conducted.

Methods

The survey was designed by the multidisciplinary team, consisting of 13 closed/3 open questions. A Likert scale was utilised for closed questions and thematic analysis for open questions. A question on impact of COVID-19 was also included.

150 of the 950 service users who received a CGA from June 2020 to June 2021 were selected randomly and invited to participate in the postal survey. All participants received a covering letter, questionnaire and a stamped address envelope to return their completed surveys.

Results

47% response rate (71/150). 77% were aged ≥75. 52% completed the survey themselves, 48% required assistance. 61% attended more than twice and most would prefer to attend a local spoke clinic. 96% agreed/strongly agreed that they were satisfied with the service. 99% felt they were treated with dignity/respect and had confidence in the service. 93% agreed that they were involved in care decisions. 82% reported their carers had the opportunity to discuss concerns. Themes emerging included importance of care close to home, avoiding acute hospital, difficulty parking at tertiary centres. 42% highlighted isolation and loneliness due to COVID-19 as a major issue.

Conclusion

Service users had an overwhelmingly positive experience especially when care was delivered in clinics close to their homes. Development of the hub and spoke model is acceptable and feasible to older people and their carers’ in this region and will be the focus for expansion of this service.

33 ARE CLINICAL TRIALS RANDOMISING HOUSEHOLDS TO LIFESTYLE INTERVENTIONS FOR THE PREVENTION OF COGNITIVE DECLINE FEASIBLE?

Background

Dementia is increasing in prevalence worldwide. Several lifestyle factors have been identified as targets for dementia prevention, which may be more effective if targeted at households instead of an individual. To date there have been no clinical trials randomising households to lifestyle interventions of sleep, diet and/or physical activity to prevent cognitive decline. To inform future studies, qualitative approaches can give valuable in-depth insights into the values and beliefs of all household members towards behavioural change.

Methods

Semi structured interviews were carried out among eight households affected by cognitive impairment. Interview content was analysed, and important themes identified.

Results

Eighteen participants were interviewed within household pods. Among those, eight had cognitive impairment and the remainder were spouses or first-degree relatives living in the same home. Several themes of interest emerged including household members without dementia were more likely to report poor sleep habits; sleep was perceived the hardest behaviour to change; although most participants had healthy diets, most were interested in making a change and felt there was a strong link with nutrition and cognition; physical activity is challenging to adapt due to lack of motivation and focus when individuals are cognitively impaired and motivation to pursue physical activity in households centred on relaxation and social interaction.

Conclusion

This study identified beliefs and preferences of households towards lifestyle intervention trials. Barriers to study participation including risk of harm, complexity of intervention and deviation from routine emerged during discussions. Findings from this study should be used to inform future clinical trial protocols and future qualitative studies should explore acceptability and feasibility of digital intervention applications.

112 INTEGRATED CARE PROGRAMME FOR OLDER PEOPLE (ICPOP) IN A RURAL SETTING—ROLE OF ADVANCED NURSE PRACTITIONER (ANP)

Background

Sláintecare advocates for right care, in the right place at the right time. ANPs for Older Persons in the community are uniquely placed to deliver care as close as possible to the older person’s home and to lead a holistic, flexible model of care minimising admission to acute care and maximising existing local resources. A pilot programme aimed at providing ANP led comprehensive geriatric assessment (CGA) (with Geriatrician support) to older people in a defined area commenced in June 2019. This pilot was part of a larger Hub and Spoke model funded by Sláintecare which gave additional MDT support.

Methods

A referral template was designed. Criteria for referral included; age &gt; 75 years, Rockwood Frailty Scale 4–6 (focusing on Falls, Cognitive Impairment and Complex Frailty). Older people on the cusp of requiring long term care (LTC) were also prioritised. A prospective database of patients was maintained by the ANP to evaluate the service.

Results

From June 2019 to August 2021, 156 patients received an ANP led CGA, mostly conducted in the home. 247 reviews were conducted at the local spoke clinic and 46 joint ANP/Geriatrician home visits. Majority of referrals were from GP (n = 69), hospital (n = 30), LTC reviews (n = 22) and Community Nursing Units (CNUs) (n = 19). 449 outpatient appointments have been removed from the tertiary referral centre. Independent case load management from the ANP includes further appointments, telephone follow up/advice and she is a point of contact where crises arise before referral to acute services. 99% of patients surveyed reported satisfaction with the service especially the ease of local access and home visits.

Conclusion

Older Persons’ ANP can provide longitudinal care pathways for older adults in the community in conjunction with ICPOP and local CNUs, intervening before crises emerge and providing continuity of care and an alternative to acute care.

102 PROMOTING BRAIN HEALTH IN AN INTEGRATED CARE OUTREACH PROGRAMME

Background

Lifestyle modifications, in older at risk populations, may prevent or slow the rate of cognitive decline. Promotion of brain health has been recommended by the WHO and other governing bodies. Supporting patients in making these lifestyle changes, however, can be complex. Generic guidance may not apply to all in a heterogenous and frail patient cohort, when physical mobility may be limited and weight loss/nutrition a concern. We sought to review current practices and barriers to brain health guidance in a regional integrated care outreach programme (ICOP).

Methods

From March–June’21 the comprehensive geriatric assessment (CGA) of consecutive patients were reviewed. Those presenting with cognitive complaints, for their first assessment, were included. Demographic data and data on screening for hearing impairment and sleep disturbance were collected, in addition to information on physical activity and nutritional risk. Whether information and guidance on aspects of brain health was given was also assessed.

Results

30 patients met the inclusion criteria. The mean age was 80.3 and the mean clinical frailty scale (CFS) was 4.4. Hearing impairment was present in 20% (n = 6), with no information available in 10% (n = 3). All patients were screened for sleep disturbance, with 13% (n = 4) not fully satisfied with their sleep. Mobility aids, assistance or supervision were required in 40% (n = 12), and 23% (n = 7) were at medium or high malnutrition risk. Only 30% (n = 9) cooked their own meals. Generic brain health advice, or advice about sleep was documented in 30 (n = 9), without hearing impairment advice documented in any patient.

Conclusion

There are several barriers to brain health advice in the ICOP setting, with only 30% of patients having brain health advice documented. We are currently developing patient information leaflets on brain health, that will take potential barriers into account. Dedicated and specific information on local hearing services is also in development, as part of an ongoing quality improvement project.

Long-term outcome of patients receiving haematopoietic allogeneic stem cell transplantation as first transplant for high-risk Hodgkin lymphoma: a retrospective analysis from the Lymphoma Working Party-EBMT

We analysed long-term outcome of patients receiving haematopoietic allogeneic stem cell transplantation (allo-HSCT) as a first transplant for high-risk Hodgkin lymphoma (HL). One hundred and ninety patients were included in this study, 63% of them had previously received brentuximab vedotin and/or checkpoint inhibitors. Seventy patients (37%) received an unrelated donor allo-HSCT, 99 (51%) had myeloablative conditioning (MAC) and 60% had in vivo T-cell/depleted grafts (TCD). The 100-day cumulative incidence (CI) of grade II-IV acute graft-versus-host disease (GVHD) was 25% and the 3-year CI of chronic GVHD was 38%. The 3-year CI of non-relapse mortality (NRM) and relapse rate were 21% and 38% respectively. After a median follow-up of 58 months, 3-year overall survival (OS) and progression-free survival (PFS) were 58% and 41% respectively. Multivariate analysis showed that, in comparison to reduced-intensity conditioning regimens with or without TCD, MAC using TCD had similar NRM and a lower risk of relapse leading to significantly better OS and PFS. MAC without TCD was associated with higher NRM and worse survival outcomes. These results suggest that in patients with high-risk HL and candidates of allo-HSCT, a MAC strategy with TCD might be the best option.

Simultaneously measured interarm blood pressure difference is not associated with pulse wave velocity in a clinical dataset of at-risk hypertensive patients

Background/Introduction

Recent analysis of systolic inter-arm differences in blood pressure from the INTERPRESS-IPD Collaboration suggest an association with increased all-cause mortality, cardiovascular mortality and cardiovascular events, previous studies have demonstrated associations with other risk parameters.

Purpose

We aimed to reproduce these associations in a cohort of 199 treated, at-risk, hypertensive patients with pulse wave velocity (PWV) as a surrogate marker of cardiovascular (CV) damage.

Methods

Simultaneously measured Inter-arm blood pressure differences, 24 hour ambulatory BP and PWV were measured in 199 treated patients of a tertiary hospital hypertension outpatient clinic. Associations between systolic inter-arm BP difference and PWV were analyzed with uni- and multivariate regression models.

Results

Out of 199 participants, 90 showed an Inter-arm blood pressure difference of more than 5 mmHg. The Inter-arm difference was not associated with PWV. Furthermore, neither observed single blood pressure measurements nor 24 hour ambulatory blood pressure was associated with Inter-arm blood pressure differences.

Conclusion

In our clinical patient cohort we failed to observe an association between inter-arm BP differences and PWV. Mode of assessment, study design or the sample characteristics of this treated, hypertensive cohort may explain the negative results. The limited sample size of the study poses a challenge to the detection of smaller effects in our study.

Funding Acknowledgement

Type of funding sources: None.

1338 Bariatric Surgery as a Viable Treatment for Idiopathic Intracranial Hypertension: A Case Series

Introduction

Idiopathic Intracranial Hypertension (IIH) is a significant cause of preventable blindness. Patients also suffer from debilitating headaches, pulsatile tinnitus, nausea, vomiting, photophobia, and radicular pain. If IIH continues to rise as predicted, treatment cost will increase to 462.7 million GBP annually by 2030. Weight loss is the only proven disease-modifying therapy for reversal of IIH. Bariatric surgery is an attractive treatment option due to superlative weight loss and reversal of related comorbidities. The case series aims to raise awareness of bariatric surgery as a safe and effective treatment modality for IIH.

Method

The case series consists of a retrospective analysis of four patients with a pre-operative diagnosis of IIH. They were referred to our department for bariatric surgery between January to December 2018. They were followed up for a total of two years.

Results

In our case series, all four patients were females with a mean age of 34 years. Mean BMI reduced from 47.3 kg/m2 before surgery to 30 kg/m2 with an EWL of 76.4% at the end of two years after surgery. They all showed significant improvement or resolution in their symptoms related to IIH, and none of them required further CSF pressure reducing procedures afterwards.

Conclusions

Bariatric surgery is a safe and effective method of treating IIH. It is superior compared to medical management and CSF pressure reducing procedures which have high rates of recurrence.

1329 Can One Size Fit All: Is Laparoscopic Roux-En-Y Gastric Bypass the Best Bariatric Procedure for Treating Type 2 Diabetes Mellitus (T2DM)?

Introduction

Bariatric surgery produces superior weight loss and reversal of comorbidities in morbidly obese individuals compared to medical therapy alone. Laparoscopic Roux-en-Y gastric bypass (LRYGB) was traditionally considered to prolonged remission of T2DM compared to other procedures such as Laparoscopic Sleeve-Gastrectomy (LSG). But recently published studies seek to disprove this by emphasising on duration and severity of T2DM before surgery rather than the type of procedure. We aim to verify if the severity of T2DM and type of operation (LRYGB Vs LSG) influence remission rates.

Method

In this retrospective cohort study, 204 patients were diagnosed with T2DM pre-operatively and had undergone either LRYGB or LSG. We used the Individualised Metabolic Surgery Score (IMSS) tool to divide patients into mild, moderate, and severe categories.

Results

Results showed that of the 204 patients 15% (n = 31) had mild disease, 62%( n = 127) had moderate disease and 23% (n = 46) had severe disease. Remission rates in each category were as follows:

Conclusions

We agree that patients with longstanding and severe T2DM have low remission rates after bariatric surgery, probably due to diminished beta-cell reserve. It is in contrary to recent publications which recommend LSG over LRYGB in patients with severe disease. This evidence necessitates further prospective studies before deciding which is the best procedure for patients with severe and longstanding T2DM.

Psychosocial burden of patients with atopic dermatitis at two tertiary referral centres in Malaysia

BACKGROUND

Atopic dermatitis (AD) is a chronic pruritic skin disorder that affects up to 20% of children and 10% of adults. The disease course is unpredictable with periods of exacerbation and remission, thus having a significant impact on the mental health and quality of life (QOL). We evaluated the prevalence of anxiety and depression and their association with disease severity, QOL and their associated factors in adolescents (≥ 13 years old) and adults with AD.

METHODS

A cross-sectional study was conducted involving patients aged ≥ 13 years with AD who fulfilled the Hanifin and Rajka diagnostic criteria. These patients were recruited from Hospital Queen Elizabeth, Kota Kinabalu and Hospital Kuala Lumpur between January 2020 to March 2021. Assessment instruments used were Scoring for Atopic Dermatitis (SCORAD), Patient-Oriented Eczema Measure (POEM), Dermatology Life Quality Index (DLQI) and Hospital Anxiety and Depression Scale (HADS).

RESULTS

Of the 217 participants, 75 (34.6%) had mild eczema, 116 (53.5%) moderate eczema and 26 (12.0%) severe eczema with a mean SCORAD score of 30.4 (standard deviation [SD] = 4.70). Twenty-six (12.0%) and 17 (7.8%) had anxiety and depression, respectively. Patients with moderate to severe disease reported higher HADS-A (HADS-anxiety component), HADS-D (HADS-depression component), POEM, DLQI, itch, sleep loss and skin pain scores (p < 0.001 for all). Severe sleep loss (adjusted odd ratio [AOR] 12.41, p < 0.001) and hospitalisation in the past year (AOR 6.44, p = 0.004) were significant predictors for anxiety whereas those aged 41 to 60 (AOR 10.83, p = 0.020), having severe skin pain (AOR 6.12, p = 0.028), DLQI ≥ 10 (AOR 5.27, p = 0.002) and history of hospitalisation in the past year (AOR 12.73, p = 0.002) had increased risk for depression.

CONCLUSION

The prevalence of anxiety was 12.0% while depression was 7.8% in our cohort. AD renders a significant burden on mental health and QOL with a higher impact on those with more severe disease. The use of screening tools such as HADS and DLQI for assessment of mental health and QOL should be considered to address the multidimensional burden of AD.

The significance of urgent ultrasound scan for shoulder dislocation in patients above the age of 40: A prospective British Elbow and Shoulder Society pathway implementation study

BACKGROUND

The highlight of the British Elbow and Shoulder Society pathway for the management of traumatic anterior shoulder instability is early imaging in patients aged over 40 years to assess rotator cuff integrity and early repair, if indicated to optimise function. The senior author set up a protocol in our institute to streamline the diagnostic process for this cohort of patients. This was a retrospective analysis from a prospectively collected database to highlight the importance of early specialist imaging.

METHODS

Our protocol is to perform urgent ultrasound scans for all suitable patients above 40 years after first-time traumatic shoulder dislocation. Demographics, associated injuries, ultrasound scan results, operations and functional outcomes were collated.

RESULTS

One year following the introduction of our protocol, 40 patients with a mean age of 67 (range, 42-89; SD = 13.1) had ultrasound. The incidence of full-thickness rotator cuff tears was 57.5% (n = 23). Eleven patients with confirmed full-thickness rotator cuff tears underwent surgery. The mean age of surgical patients was significantly younger than the non-surgical group (p = 0.004).

DISCUSSION

The use of early diagnostic imaging demonstrated a high incidence of full-thickness rotator cuff tears in this cohort of patients. This allowed early surgical repair to optimise function.

A47 SYNTHETIC HUMAN MILK OLIGOSACCHARIDES PREVENT EXPERIMENTAL NECROTIZING ENTEROCOLITIS VIA DIVERGENT TRANSCRIPTOMIC RESPONSES

Background

Breastmilk reduces the risk of necrotizing enterocolitis (NEC) in preterm infants, but the bioactive components mediating this effect are not well understood. Human milk oligosaccharides (HMOs) reduce NEC both in humans and in relevant animal models. However, it is unclear if there are functional differences between individual oligosaccharides.

Aims

The objective of this study was to compare the intestinal transcriptome responses of individual HMOs using complementary in vitro and in vivo models of NEC.

Methods

RNA sequencing was performed on Caco-2Bbe1 gut epithelial cells after exposure to commercially-purified 2’-fucosyllactose (2’FL), 3-fucosyllactose, 6’-siallyllactose, lacto-N-tetraose (LNT) or lacto-N-neotetraose for 24hr at 37°C for 24 h (n=3). Signaling pathways were analyzed in murine- and human-derived NEC enteroids by qPCR. To validate these findings, five-day-old mouse pups were orally gavaged formula with or without individual HMOs, followed by NEC induction with hypoxia (5% O2, 95% N2) and lipopolysaccharide (4 mg/kg/day). Coded ileal sections (n=6–7/group) were analyzed for mucosal injury by histology, immune fluorescence, immunohistochemistry, and gene expression via qPCR.

Results

The HMO transcriptome clustered into divergent functional categories including metabolic process, protein processing and responses to external stimuli. Each synthetic HMO induced a unique transcriptome and exhibited varying effects on the intestinal epithelial functions and biological pathways. This was confirmed in the murine model of NEC, as both LNT and 2FL mitigated NEC injury with comparable recovery of intestinal cell proliferation (Ki67) and expression of stem cells (Lgr5+). Both qPCR and immunofluorescence staining showed differences between 2FL- and LNT-fed pups in host inflammatory and immune responses.

Conclusions

This study demonstrates that synthetic HMOs ameliorate intestinal injury in experimental NEC. However, the mechanisms by which individual oligosaccharides act on the intestine differ, suggesting that single synthetic HMOs may not fully recapitulate the benefits of pooled HMOs. Future studies will further delineate structure-function relationships of synthetic HMOs on host intestinal innate and adaptive immune responses.

Funding Agencies

CIHRFerring Canada Medical Student Research grant

The traveling heads 2.0: Multicenter reproducibility of quantitative imaging methods at 7 Tesla

OBJECT

This study evaluates inter-site and intra-site reproducibility at ten different 7 T sites for quantitative brain imaging.

MATERIAL AND METHODS

Two subjects - termed the "traveling heads" - were imaged at ten different 7 T sites with a harmonized quantitative brain MR imaging protocol. In conjunction with the system calibration, MP2RAGE, QSM, CEST and multi-parametric mapping/relaxometry were examined.

RESULTS

Quantitative measurements with MP2RAGE showed very high reproducibility across sites and subjects, and errors were in concordance with previous results and other field strengths. QSM had high inter-site reproducibility for relevant subcortical volumes. CEST imaging revealed systematic differences between the sites, but reproducibility was comparable to results in the literature. Relaxometry had also very high agreement between sites, but due to the high sensitivity, differences caused by different applications of the B1 calibration of the two RF coil types used were observed.

CONCLUSION

Our results show that quantitative brain imaging can be performed with high reproducibility at 7 T and with similar reliability as found at 3 T for multicenter studies of the supratentorial brain.

Echocardiographic RV-E/e' for predicting right atrial pressure: a review

Right atrial pressure (RAP) is a key cardiac parameter of diagnostic and prognostic significance, yet current two-dimensional echocardiographic methods are inadequate for the accurate estimation of this haemodynamic marker. Right-heart trans-tricuspid Doppler and tissue Doppler echocardiographic techniques can be combined to calculate the right ventricular (RV) E/e′ ratio – a reflection of RV filling pressure which is a surrogate of RAP. A systematic search was undertaken which found seventeen articles that compared invasively measured RAP with RV-E/e′ estimated RAP. Results commonly concerned pulmonary hypertension or advanced heart failure/transplantation populations. Reported receiver operating characteristic analyses showed reasonable diagnostic ability of RV-E/e′ for estimating RAP in patients with coronary artery disease and RV systolic dysfunction. The diagnostic ability of RV-E/e′ was generally poor in studies of paediatrics, heart failure and mitral stenosis, whilst results were equivocal in other diseases. Bland–Altman analyses showed good accuracy but poor precision of RV-E/e′ for estimating RAP, but were limited by only being reported in seven out of seventeen articles. This suggests that RV-E/e′ may be useful at a population level but not at an individual level for clinical decision making. Very little evidence was found about how atrial fibrillation may affect the estimation of RAP from RV-E/e′, nor about the independent prognostic ability of RV-E/e′ . Recommended areas for future research concerning RV-E/e′ include; non-sinus rhythm, valvular heart disease, short and long term prognostic ability, and validation over a wide range of RAP.

MODL-20. A BIOBANK OF ~100 PATIENT-DERIVED MODELS REPRESENTING BIOLOGICAL HETEROGENEITY AND DISTINCT THERAPEUTIC DEPENDENCIES IN PAEDIATRIC HIGH GRADE GLIOMA AND DIPG

Paediatric high-grade glioma comprise multiple biological and clinical subgroups, the majority of which urgently require novel therapies. Patient-derived models represent useful tools for mechanistic and preclinical investigations based upon their retention of key genetic/epigenetic features and their amenability to high-throughput approaches. We have collected ~100 in vitro models representing multiple subtypes (H3.3/H3.2/H3.1K27M, H3.3G34R/V, BRAF, MYCN_amp, NTRK_fusion, hypermutator, others) established under 2D (laminin) and/or 3D (neurosphere) conditions, credentialed by phenotypic (growth, invasion/migration) and molecular (methylation array, DNA sequencing, RNAseq) comparison to the original tumour sample. These were derived from patients at our local hospitals (n=29), as part of national co-clinical trials (n=19), from international collaborating centres (n=11), or shared directly by research groups worldwide (n=45). These have variously been subjected to pharmacological (approved/experimental drug libraries) and/or genetic screening (whole-genome CRISPR) to identify specific biological dependencies. Many have been established as orthotopic xenografts in vivo (PDX), with detailed pathological and radiological correlations with the clinical disease, and with tumorigenic latencies ranging from 48–435 days. This resource has allowed us to identify genotype-specific synthetic lethalities and responses to targeted inhibitors, including olaparib (PARP) with ATRX, nutlin-3 (MDM2) with PPM1D, AZD1775 (WEE1) with TP53, and CYC065 (CDK9) with MYCN-amplification. Combinatorial screening highlighted synergies in ACVR1-mutant DIPG between novel ALK2 inhibitors and ONC201 (DRD2). Rapid screening allows for feedback of drug sensitivities to treating clinicians at relapse, whilst mechanistic underpinning of these interactions and use of the models to identify specific mediators of resistance will allow for rational future trial design.

IMG-12. CHARACTERISATION OF MODELS OF H3F3A_G34R/V MUTANT PAEDIATRIC GLIOBLASTOMA IN VIVO USING MAGNETIC RESONANCE IMAGING

Approximately 15% of paediatric/young adult cerebral hemispheric glioblastomas (pGBM) harbour G34R/V mutations in H3F3A, encoding the histone H3.3 variant. Development of novel therapeutic interventions demands models that accurately recapitulate this subset of disease and sensitive imaging methods with which to study tumours in situ. Three H3F3A_G34R primary-patient-derived cultures, alongside established cell-line KNS42 (H3F3A_G34V), were implanted orthotopically in immunocompromised mice. KNS42 (TP53_R342*) tumours were clearly detectable using T2-weighted (T2w)-MRI, enhanced following contrast agent administration, indicating impaired blood-brain barrier (BBB) integrity, and demonstrated minimal invasion. OPBG_GBM_001 cells (TP53_89-90X,ATRX_II2133-2144X) formed infiltrative tumours that were hyperintense on T2w-MRI and demonstrated contrast-enhancement suggestive of heterogeneous BBB integrity. HSJD_GBM_002 cells (TP53_P278T,ATRX_R666*) spread diffusely throughout the brain with their full extent typically not discernible by T2w-MRI, the BBB also remaining intact. No evidence of CHOP_GBM_001 tumour was detected by MRI 11months post-implantation. Immunocompetent syngeneic models using tumour cells induced by mutations modelling hemispheric pGBM (NRAS/shP53/shATRX±H3.3G34R) are being explored. Fast growing heterogeneous lesions with variable contrast-enhancement were identified; the H3.3G34R mutation conferred longer median survival (2 clones:25/28days, control:14days). These models have the advantage of an intact immune system and short latency for initial efficacy studies. Primary pGBM cells yield tumours that are more representative of the spectrum of clinical disease; variable hyperintensity on T2w-MRI corresponding to cellular density, with diffusely infiltrative disease less clearly definable, a paucity of oedema and a range of contrast-enhancement. Pathological features including giant multinucleated cells, and mitotic figures were also evident.

Tools to predict acute traumatic coagulopathy in the pre-hospital setting: a review of the literature

Introduction:

Recognising acute traumatic coagulopathy (ATC) poses a significant challenge to improving survival in emergency care. Paramedics are in a prime position to identify ATC in pre-hospital major trauma and initiate appropriate coagulopathy management.

Method:

A database literature review was conducted using Scopus, CINAHL and MEDLINE.

Results:

Two themes were identified from four studies: prediction tools, and point-of-care testing. Prediction tools identified key common ATC markers in the pre-hospital setting, including: systolic blood pressure, reduced Glasgow Coma Score and trauma to the chest, abdomen and pelvis. Point-of-care testing was found to have limited value.

Conclusion:

Future research needs to explore paramedics using prediction tools in identifying ATC, which could alert hospitals to prepare for blood products for damage control resuscitation.

Bruton tyrosine kinase inhibitors for the frontline treatment of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (cll) is the most commonly diagnosed adult leukemia in Canada. Biologic heterogeneity of cll between patients results in variable disease trajectories and responses to therapy. Notably, compared with patients lacking high-risk features, those with such features-such as deletions in chromosome 17p, aberrations in the TP53 gene, or unmutated immunoglobulin heavy chain variable region genes-experience inferior outcomes and responses to standard chemoimmunotherapy. Novel agents that target the B cell receptor signalling pathway, such as Bruton tyrosine kinase (btk) inhibitors, have demonstrated clinical efficacy and safety in patients with treatment-naïve cll, particularly those with high-risk features. However, given the current lack of head-to-head trials comparing btk inhibitors, selection of the optimal btk inhibitor for patients with cll is unclear and requires consideration of multiple factors. In the present review, we focus on the efficacy, safety, and pharmacologic features of the btk inhibitors that are approved or under clinical development, and we discuss the practical considerations for the use of those agents in the Canadian treatment landscape.

Molecular MR-Imaging for Noninvasive Quantification of the Anti-Inflammatory Effect of Targeting Interleukin-1β in a Mouse Model of Aortic Aneurysm

Background:

Molecular-MRI is a promising imaging modality for the assessment of abdominal aortic aneurysms (AAAs). Interleukin-1β (IL-1β) represents a new therapeutic tool for AAA-treatment, since pro-inflammatory cytokines are key-mediators of inflammation. This study investigates the potential of molecular-MRI to evaluate therapeutic effects of an anti-IL-1β-therapy on AAA-formation in a mouse-model.

Methods:

Osmotic-minipumps were implanted in apolipoprotein-deficient-mice (N = 27). One group (Ang-II+01BSUR group, n = 9) was infused with angiotensin-II (Ang-II) for 4 weeks and received an anti-murine IL-1β-antibody (01BSUR) 3 times. One group (Ang-II-group, n = 9) was infused with Ang-II for 4 weeks but received no treatment. Control-group (n = 9) was infused with saline and received no treatment. MR-imaging was performed using an elastin-specific gadolinium-based-probe (0.2 mmol/kg).

Results:

Mice of the Ang-II+01BSUR-group showed a lower aortic-diameter compared to mice of the Ang-II-group and control mice (p < 0.05). Using the elastin-specific-probe, a significant decrease in elastin-destruction was observed in mice of the Ang-II+01BSUR-group. In vivo MR-measurements correlated well with histopathology (y = 0.34x-13.81, R² = 0.84, p < 0.05), ICP-MS (y = 0.02x+2.39; R² = 0.81, p < 0.05) and LA-ICP-MS. Immunofluorescence and western-blotting confirmed a reduced IL-1β-expression.

Conclusions:

Molecular-MRI enables the early visualization and quantification of the anti-inflammatory-effects of an IL-1β-inhibitor in a mouse-model of AAAs. Responders and non-responders could be identified early after the initiation of the therapy using molecular-MRI.

High-Sensitivity Cardiac Troponin-Optimizing the Diagnosis of Acute Myocardial Infarction/Injury in Women (CODE-MI): Rationale and design for a multicenter, stepped-wedge, cluster-randomized trial

Despite evidence that high-sensitivity cardiac troponin (hs-cTn) levels in women are lower than in men, a single threshold based on the 99th percentile upper reference limit of the overall reference population is commonly used to diagnose myocardial infarction in clinical practice. This trial aims to determine whether the use of a lower female-specific hs-cTn threshold would improve the diagnosis, treatment, and outcomes of women presenting to the emergency department with symptoms suggestive of myocardial ischemia. METHODS/DESIGN: CODE-MI (hs-cTn-Optimizing the Diagnosis of Acute Myocardial Infarction/Injury in Women) is a multicenter, stepped-wedge, cluster-randomized trial of 30 secondary and tertiary care hospitals across 8 Canadian provinces, with the unit of randomization being the hospital. All adults (≥20 years of age) presenting to the emergency department with symptoms suggestive of myocardial ischemia and at least 1 hs-cTn test are eligible for inclusion. Over five, 5-month intervals, hospitals will be randomized to implement lower female hs-cTn thresholds according to the assay being used at each site. Men will continue to be assessed using the overall thresholds throughout. Women with a peak hs-cTn value between the female-specific and the overall thresholds will form our primary cohort. The primary outcome, a 1-year composite of all-cause mortality or readmission for nonfatal myocardial infarction, incident heart failure, or emergent/urgent coronary revascularization, will be compared before and after the implementation of female thresholds using mixed-effects logistic regression models. The cohort and outcomes will be obtained from routinely collected administrative data. The trial is designed to detect a 20% relative risk difference in the primary outcome, or a 2.2% absolute difference, with 82% power. CONCLUSIONS: This pragmatic trial will assess whether adopting lower female hs-cTn thresholds leads to appropriate assessment of women with symptoms suggestive of myocardial infarction, thereby improving treatment and outcomes.