LGG-50. Human induced pluripotent stem cell engineering establishes a humanized mouse platform for pediatric low-grade glioma modeling

A major obstacle to identifying improved treatments for pediatric low-grade brain tumors (gliomas) is the inability to reproducibly generate human xenografts. To surmount this barrier, we leveraged human induced pluripotent stem cell (hiPSC) engineering to generate low-grade glioma (LGG) lesions representing the two most common pediatric pilocytic astrocytoma-associated molecular alterations, NF1 loss and KIAA1549:BRAF fusion. Using hiPSCs, we identified the susceptible cells of origin for these tumors, and demonstrated that the resulting tumors retain LGG histologic features for at least 6 months in vivo. Finally, this platform enabled the successful long-term growth of patient-derived pLGGs in vivo. Taken together, these avatars establish tractable experimental humanized platforms to elucidate the pathogenesis of childhood brain tumors.

Sexual and Reproductive Health Needs Assessment & Interventions in a Female Psychiatric Intensive Care Unit

Introduction

This quality improvement project was a collaboration between an adult, inpatient female psychiatric intensive care unit (PICU) in South London and the Sexual and Reproductive Health Rights, Inclusion and Empowerment (SHRINE) programme. SHRINE is a London-based programme delivering SRH care to any individual with serious mental illness, substance misuse and/or learning disability.

Objectives

The primary aim of this quality improvement project was to assess patients’ sexual and reproductive (SRH) needs, and the acceptability of providing SRH assessments in a female PICU setting. Secondary aims were to explore the barriers to access and the feasibility of providing SRH assessments and SHRINE interventions in the PICU.

Methods

A bi-monthly SRH in-reach clinic and a nurse led SRH referral pathway were implemented on the PICU over a seven-month period. Within a quality improvement framework, a staff training needs assessment was performed, training delivered, a protocol developed, staff attitudes explored, and patient and carer engagement sought.

Results

30% of women were identified as having unmet SRH needs and proceeded to a specialist appointment, representing a 2.5-fold increase in unmet need detection. 42% of women were assessed, representing a 3.5-fold increase in uptake. 21% of women initiated SRH interventions of which 14% had all their SRH needs met.

Conclusions

Results identified SRH needs for PICU admissions are greater than realised. Staff highlighted the acceptability and importance of SRH care, if interventions are appropriately timed and the patient’s individual risk profile considered. Providing a nurse-led referral pathway for an SRH in-reach clinic is acceptable, feasible and beneficial for PICU patients.

Disclosure

No significant relationships.

Antimicrobial prescribing and antimicrobial resistance surveillance in equine practice

BACKGROUND

Antimicrobial resistance (AMR) is an increasingly serious threat to human and animal health, therefore responsible use of antimicrobials in equine practice is vital. There is a need to have accurate, up to date data on antimicrobial prescribing in equine practice in the UK.

OBJECTIVES

To characterise current antimicrobial prescribing practices by equine veterinarians and to describe surveillance, audit processes and identification of AMR.

STUDY DESIGN

Online cross-sectional, questionnaire-based survey.

METHODS

An online questionnaire targeting veterinarians who treat horses in the UK and Europe was distributed. The questionnaire collected data on participants' country of origin, practice policies, prescribing practices including use of high priority critical antimicrobials. Four common clinical case-based scenarios were included to further explore prescribing practice. Responses were compared using both descriptive statistics and multivariable logistic regression models.

RESULTS

Questionnaires were completed by 264 veterinarians from Europe (n=33/264) and the UK (n=231/264); 87% respondents worked only with horses and 67% worked at premises with hospitalisation facilities. Approximately half of respondents (54.4%) had a written antimicrobial use or stewardship policy within their practice. Over half of respondents did not perform any environmental surveillance (54.2%), audit of clinical infections (53.1%) or audit of infection control (57.1%). Potentiated sulphonamides were cited as the most used antimicrobial, although 44% reported using enrofloxacin in the last year and 66% used 3^rd or 4^th generation cephalosporins. Prophylactic antimicrobials before clean surgery were frequently/always prescribed by 48% respondents and 24% respondents frequently/always prescribed antimicrobials post-operatively in clean surgery.

MAIN LIMITATIONS

Potential selection bias of respondents, given individuals volunteered to take part in the survey.

CONCLUSIONS

Compared to a previous similar study conducted in 2009, overall antimicrobial usage appeared to be declining in clinical scenarios and a greater proportion of practices now have stewardship policies. However, the use of high priority critical antimicrobials is still relatively common in equine practice in the UK and Europe.

Defining the incidence of cutaneous squamous cell carcinoma in coastal NSW Australia

BACKGROUND/OBJECTIVES

To describe the incidence of primary cutaneous squamous cell carcinoma in coastal NSW Australia.

METHODS

The design is a case-controlled study of reported cSCC from 2016 to 2019 within a defined region of coastal southern NSW. Participants include all reported pathological diagnoses of cSCC in patients greater than 20 years of age. The main outcome measures the incidence and relative risk of cSCC.

RESULTS

The overall age-adjusted incidence rate of primary cSCC was 856//year. Men over 60 years of age had an age-adjusted incidence rate of 2875/10⁶ /year. Histologically diagnosed invasive SCC samples were included using SNOMED clinical term codes. Keratoacanthomas and SCC in situ SNOWMED codes were not included. SCC in situ results was found within the sample analysis and was offset by including one SCC per annum per person.

CONCLUSIONS

The rates of cSCC are far higher than previously reported and demand a reappraisal of our national management of this disease.

Osteoporosis and Psoriasis: A Literature Review

Psoriasis is a chronic inflammatory skin disease with complex comorbidities. Recent evidence has revealed how the inflammatory nature of psoriasis affects bone mineral density and may lead to osteoporosis. This review outlines the current understanding and advances on the association between psoriasis and osteoporosis. The current literature suggests an increased risk of osteopenia and osteoporosis in patients with extensive and chronic psoriasis, compounded by other lifestyle and genetic factors. It suggests that prophylactic measures such as vitamin D supplementation and increasing weight‐bearing exercises can help, but in patients with extensive psoriasis, prolonged systemic inflammation may require long‐term management. Although there have been many short‐term RCTs on the efficacy and safety of biologics in psoriasis, clinical studies looking at the long‐term effects of biologics, such as whether they might improve bone mineral density in these patients with psoriasis are yet to be conducted.

A163 EVALUATING THE ASSOCIATION BETWEEN PERIPHERAL BLOOD EOSINOPHILS AND DRUG RESPONSE IN CROHN’S DISEASE: A PRELIMINARY REPORT

Background

Th1, Th2, and Th17 immune pathways are variably activated in inflammatory bowel disease (IBD). The degree to which pathway having a more dominant role in propagating Crohn’s disease (CD) is not considered when selecting a treatment strategy. Th2 cytokines, IL-5 and IL-13 enhance eosinophil survival, recruitment and degranulation, facilitating inflammation. Mucosal eosinophilia has been documented in CD and its presence is a surrogate marker of Th2 pathway activation. Peripheral eosinophilia has an established role in asthma to help prognosticate treatment response to Th2-cytokine-specific therapies. We hypothesize the pattern of peripheral blood eosinophils (PBE) at CD diagnosis will identify distinct subsets within a larger CD population and correlate with response to treatments such as prednisone or anti-TNFs.

Aims

We aim to evaluate the pattern of PBE of CD patients at time of diagnosis (prior to drug exposure) and with each subsequent treatment; and if baseline PBE or any changes seen with drug exposures are predictive of treatment response.

Methods

A retrospective cohort study is ongoing with CD patients exposed to glucocorticoids and an anti-TNF seen at one of 3 hospitals affiliated with University of Western Ontario. Patients were identified using administrative databases and reviewed for biochemical data (complete blood count) and disease activity (Harvey Bradshaw Index) at baseline as well as before and after each drug exposure. Participants were classified as having high PBE (eosinophils >200 cells/μl) versus low PBE (eosinophils <200 cells/μl).

Results

To date,10 of 200 CD patients are included in the preliminary analyses with a mean age of 47. 8 had PBE >200 cells/μL at baseline, while 2 did not. The median number therapies used was 4 (IQR=0.75). All received glucocorticoids followed by an anti-TNF. There was no difference in the occurrence of hospitalization or surgery between the two cohorts. Overall 75% (n=6/8) participants with high PBE had clinical response to glucocorticoid exposure, seen as a 3-point decrease in HBI compared to 0% (n=0/2, p=0.5) in the low PBE cohort. With subsequent anti-TNF exposure, PBE rebounded in 6 participants. More patients in the high PBE group required anti-TNF dose escalation versus the low PBE group (63%, n=5/8 versus 50%, n=1/2, p=0.99). The proportion of patients with anti-TNF discontinuation was similar in both groups (high PBE, 50%, n=4/8 versus low PBE, 50%, n=1/2, p=1.00).

Conclusions

Peripheral eosinophilia is seen in varying degrees in CD patients. Participants with high PBE appear to be more steroid-responsive which is typical for Th2-mediated pathways. They were less responsive to Th1-targeting anti-TNF therapies, requiring more dose-escalation and discontinued anti-TNF treatment. Completion of this study will help clarify the association between PBE in CD and treatment response.

Funding Agencies

None

A142 IMPACT OF HLADQA1*05G>A GENETIC-SCREENING FOR OPTIMAL ANTI-TNF THERAPY IN INFLAMMATORY BOWEL DISEASE: A PRELIMINARY REPORT

Background

Genetic variation in the human leukocyte antigen ( HLA) gene is strongly associated with the formation of anti-drug antibodies to tumor necrosis factor-alpha antagonists (anti-TNF) in inflammatory bowel disease (IBD). It is also associated anti-TNF loss of response and treatment discontinuation.

Aims

We aimed to evaluate the utility of preemptive HLADQA1*05G&gt;A screening to reduce the incidence of treatment-related adverse events in an IBD population by lessening the need for combination therapy in those who do not carry the risk allele. We also assessed for the occurrence of anti-TNF anti-drug antibody (ADA) formation, anti-TNF loss of response, treatment discontinuation compared to an unscreened population.

Methods

A non-randomized open label study is ongoing in IBD patients being considered for anti-TNF therapy. Participants received either pre-treatment HLADQA1*05G&gt;A screening (prospective-screening group, n=25/110 recruited), with the addition of one of azathioprine or methotrexate to anti-TNF therapy (combination therapy) if identified as a high risk variant carrier (G/A or A/A) or received combination therapy without undergoing prospective HLADQA1*05A&gt;G screening (control group, n=25/110 recruited). All participants will be followed for up to 1 year and observed for the occurrence of any adverse drug events, formation of anti-TNF drug antibodies (ADA), anti-TNF loss of response and anti-TNF discontinuation.

Results

To date, the prevalence of HLADQA1*05 G/A and A/A was 20% in the prospective-screening group and thus 20% (n=5/25) received combination therapy and 80% (n=20) received anti-TNF monotherapy. All participants in the control group (n=25/25) received combination therapy. Considering all groups, 78% (n=39/50) received infliximab, while 22% (n=11/50) received adalimumab. To date, the median follow-up period is 5 (IQR=4) months. Fewer adverse drug events have been reported in the prospective-screening group versus the control group (16.7% vs 33.3%, odds ratio 0.40, 95%CI=0.12–1.56, p=0.18). Anti-TNF ADA formation and treatment discontinuation were similar between groups (prospective-screening, 0% versus control, 4.2%). A higher proportion of controls experienced anti-TNF loss of response (16.7% vs 8.3%, p=0.38).

Conclusions

Preemptive HLADQA1*05G&gt;A screening appears to reduce the need for combination therapy when using anti-TNF agents in an IBD population. Fewer drug-related adverse events are reported to date in the screened cohort without a concomitant increase in deleterious outcomes such as ADA formation or anti-TNF discontinuation. Completion of this study will help define whether or not HLADQA1*05G&gt;A-screening is a clinically-actionable and relevant tool for guiding the application of combination therapy in IBD.

Funding Agencies

Lawson Health Research Institute

Demographic, clinical, and service-use characteristics related to the clinician's recommendation to transition from child to adult mental health services

PURPOSE

The service configuration with distinct child and adolescent mental health services (CAMHS) and adult mental health services (AMHS) may be a barrier to continuity of care. Because of a lack of transition policy, CAMHS clinicians have to decide whether and when a young person should transition to AMHS. This study describes which characteristics are associated with the clinicians' advice to continue treatment at AMHS.

METHODS

Demographic, family, clinical, treatment, and service-use characteristics of the MILESTONE cohort of 763 young people from 39 CAMHS in Europe were assessed using multi-informant and standardized assessment tools. Logistic mixed models were fitted to assess the relationship between these characteristics and clinicians' transition recommendations.

RESULTS

Young people with higher clinician-rated severity of psychopathology scores, with self- and parent-reported need for ongoing treatment, with lower everyday functional skills and without self-reported psychotic experiences were more likely to be recommended to continue treatment. Among those who had been recommended to continue treatment, young people who used psychotropic medication, who had been in CAMHS for more than a year, and for whom appropriate AMHS were available were more likely to be recommended to continue treatment at AMHS. Young people whose parents indicated a need for ongoing treatment were more likely to be recommended to stay in CAMHS.

CONCLUSION

Although the decision regarding continuity of treatment was mostly determined by a small set of clinical characteristics, the recommendation to continue treatment at AMHS was mostly affected by service-use related characteristics, such as the availability of appropriate services.

Clinical features of chronic bullous dermatosis of childhood

BACKGROUND

Chronic bullous dermatosis of childhood (CBDC) is a rare autoimmune subepidermal blistering disease, which can develop following vaccination or medication, or with an autoimmune condition or illness, among other causes.

AIM

To identify and better understand the clinical features of CBDC by performing a systematic review, in line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

METHODS

Eligible studies included publication since 1980, CBDC diagnosis, case studies, subjects aged < 18 years, clinical features and no language restriction. A database search was conducted including Embase, MEDLINE and Scopus on 14 July 2021 (see Appendix for search terms). Data were assessed for risk of bias. Jamovi was used for statistical analysis. Age and sex were compared with mucocutaneous involvement, cutaneous involvement, other symptoms, human leucocyte antigen type and lesion descriptions.

RESULTS

After removing duplicate references using Endnote, 351 papers were identified, of which 91 met the inclusion criteria. These papers included 130 cases of CBDC: 110 children and 20 neonates. The ratio of male : female patients was 19 : 1 for neonates and 74:55 for children. χ² analysis with 1 degree of freedom showed that CBDC in neonates was associated with facial (χ²₍₁₎  = 9.67, P < 0.01), mouth (χ²₍₁₎  = 31.0, P < 0.001), upper airway (χ²₍₁₎  = 52.7, P < 0.001), oesophageal (χ²₍₁₎  = 34.6, P < 0.001), ophthalmic (χ²₍₁₎  = 6.27, P = 0.01) involvement and with respiratory distress (χ²₍₁₎  = 22.7 P < 0.001). CBDC in children was associated with genital (χ²₍₁₎  = 3.96, P < 0.05), arm (χ²₍₁₎  = 6.99, P < 0.01) and leg (χ²₍₁₎  = 7.03, P < 0.01) involvement. CBDC in male patients was associated with facial (χ²₍₁₎  = 7.01, P < 0.01), scalp (χ²₍₁₎  = 5.96, P < 0.02) and perianal (χ²₍₁₎  = 7.22, P < 0.01) involvement.

CONCLUSION

Neonates with CBDC are more likely to have a mucocutaneous distribution of lesions, whereas children are more likely to have cutaneous lesions. The limitations of this study include selection bias, and the small neonate sample size makes the study unrepresentative of the population. The review highlights the need for further research into the clinical features of CBDC in neonates.

Cohort profile: demographic and clinical characteristics of the MILESTONE longitudinal cohort of young people approaching the upper age limit of their child mental health care service in Europe

PURPOSE

The presence of distinct child and adolescent mental health services (CAMHS) and adult mental health services (AMHS) impacts continuity of mental health treatment for young people. However, we do not know the extent of discontinuity of care in Europe nor the effects of discontinuity on the mental health of young people. Current research is limited, as the majority of existing studies are retrospective, based on small samples or used non-standardised information from medical records. The MILESTONE prospective cohort study aims to examine associations between service use, mental health and other outcomes over 24 months, using information from self, parent and clinician reports.

PARTICIPANTS

Seven hundred sixty-three young people from 39 CAMHS in 8 European countries, their parents and CAMHS clinicians who completed interviews and online questionnaires and were followed up for 2 years after reaching the upper age limit of the CAMHS they receive treatment at.

FINDINGS TO DATE

This cohort profile describes the baseline characteristics of the MILESTONE cohort. The mental health of young people reaching the upper age limit of their CAMHS varied greatly in type and severity: 32.8% of young people reported clinical levels of self-reported problems and 18.6% were rated to be 'markedly ill', 'severely ill' or 'among the most extremely ill' by their clinician. Fifty-seven per cent of young people reported psychotropic medication use in the previous half year.

FUTURE PLANS

Analysis of longitudinal data from the MILESTONE cohort will be used to assess relationships between the demographic and clinical characteristics of young people reaching the upper age limit of their CAMHS and the type of care the young person uses over the next 2 years, such as whether the young person transitions to AMHS. At 2 years follow-up, the mental health outcomes of young people following different care pathways will be compared.

TRIAL REGISTRATION NUMBER

NCT03013595.

Long-term outcomes of intravenous drug use associated infective endocarditis: a contemporary 20-year study

Introduction

Intravenous drug use (IVDU) associated infective endocarditis (IE) is a clinically challenging case. Not only can the natural history of IE in the IVDU population be significantly different, making detection a diagnostic dilemma, additional social factors associated with this population can drastically change management, including suitability for surgery or long-term intravenous access for antibiotics Furthermore, the rates of IVDU are increasing globally, leading to increasing incidence of IVDU associated IE.

Purpose

With a lack of clear mangement guidelines for IVDU associated IE, our study assesses the differences in presentation, management and long-term prognosis of IE between the IVDU population and the non-IVDU population to help guide future care.

Methods

This is an observational cohort study on a prospectively collected database of 350 patients treated for IE at our centre between 1999 and 2015. Patients were followed-up until death or January 2021. The primary outcome was all-cause mortality. Continuous variables were compared using unpaired t-test. Categorical variables were compared using Chi-square test when sample size was &gt;5 or Fisher's exact test when sample size was ≤5. Long-term survival data was analysed using Kaplan-Meier survival curves.

Results

The IVDU population was younger, more likely to have concurrent infections and other substance use, while the non-IVDU population was older with a higher level of overall comorbidity. IVDU patients were more likely to become reinfected (p-value=0.034) but had better long-term survival compared to the non-IVDU population (p&lt;0.001). Survival estimates at 15-years were 64.98% (95% CI: 50.94–75.92%) for the IVDU population compared to 26.67% (95% CI: 19.76–34.05%) for the non-IVDU population (p-value&lt;0.0001).

Conclusion

Despite having higher levels of reinfection, IVDU patients have better long-term outcomes of IE compared to non-IVDU patients. Therefore, IVDU patients should not have blanket restrictions on the management they are offered unless the individual has clear contraindications to a particular therapy.

Funding Acknowledgement

Type of funding sources: None.

748 Case Series: Experience of Using External Fixation as An Adjunct in The Management of MRONJ Affecting the Mandible

Introduction

External fixation was first described by Malgaigne and Rigaud in 1870 for use on long bones, then adapted for OMFS in 1934 and used for treating comminuted fractures. In recent times, popularity of external fixators has decreased with the use of mini-plates, often only used in major trauma, for example gunshot wounds. This is a case series of patients who have been treated by external fixation for medication related osteonecrosis (MRONJ) of the jaw and could be a fairly simple alternative to major reconstructive surgery in such cases. This method of treatment has been particularly useful during the Covid-19 pandemic as a non-aerosol generating procedure.

Method

A single centre, retrospective study of 5 cases between December 2018 - December 2020. The MRONJ cases were graded using the AAOMS classification. All cases treated with external fixation of mandible were included. Pre-operative condition, medical history, treatment complications, pain management, length of treatment and follow-up results were recorded.

Results

Of the 5 cases treated for MRONJ, 4 of these had pathological fractures. All were AAOMS stage 3. The mean duration of treatment was 78 days, with regular clinical reviews monitoring progress. Of these cases, 4 cases healed well with significant improvement or closure of intraoral and extra-oral wounds.

Conclusions

In this small case series the technique has shown positive results; being well received by patients and allowing function while in situ. It allows treatment of pathological fractures as well as stabilising the mandible as a preventative measure whilst debriding severely atrophic mandibles.

Comparison of Intensive Care and Trauma-specific Scoring Systems in Critically Ill Patients

INTRODUCTION

Amongst critically ill trauma patients admitted to ICU and still alive and in ICU after 24 hours, it is unclear which trauma scoring system offers the best performance in predicting in-hospital mortality.

METHODS

The Australia and New Zealand Intensive Care Society Adult Patient Database and Victorian State Trauma Registry were linked using a unique patient identification number. Six scoring systems were evaluated: the Australian and New Zealand Risk of Death (ANZROD), Acute Physiology and Chronic Health Evaluation III (APACHE III) score and associated APACHE III Risk of Death (ROD), Trauma and Injury Severity Score (TRISS), Injury Severity Score (ISS), New Injury Severity Score (NISS) and the Revised Trauma Score (RTS). Patients who were admitted to ICU for longer than 24 hours were analysed. Performance of each scoring system was assessed primarily by examining the area under the receiver operating characteristic curve (AUROC) and in addition using standardised mortality ratios, Brier score and Hosmer-Lemeshow C statistics where appropriate. Subgroup assessments were made for patients aged 65 years and older, patients between 18 and 40 years of age, major trauma centre and head injury.

RESULTS

Overall, 5,237 major trauma patients who were still alive and in ICU after 24 hours were studied from 25 ICUs in Victoria, Australia between July 2008 and January 2018. Hospital mortality was 10.7%. ANZROD (AUROC 0.91; 95% CI 0.90-0.92), APACHE III ROD (AUROC 0.88; 95% CI 0.87-0.90), and APACHE III (AUROC 0.88; 95% CI 0.87-0.89) were the best performing tools for predicting hospital mortality. TRISS had acceptable overall performance (AUROC 0.78; 95% CI 0.76-0.80) while ISS (AUROC 0.61; 95% CI 0.59-0.64), NISS (AUROC 0.68; 95% CI 0.65-0.70) and RTS (AUROC 0.69; 95% CI 0.67-0.72) performed poorly. The performance of each scoring system was highest in younger adults and poorest in older adults.

CONCLUSION

In ICU patients admitted with a trauma diagnosis and still alive and in ICU after 24 hours, ANZROD and APACHE III had a superior performance when compared with traditional trauma-specific scoring systems in predicting hospital mortality. This was observed both overall and in each of the subgroup analyses. The anatomical scoring systems all performed poorly in the ICU population of Victoria, Australia.

Assessing the Impact of Wildfires on the Use of Black Carbon as an Indicator of Traffic Exposures in Environmental Epidemiology Studies

Epidemiological studies frequently use black carbon (BC) as a proxy for traffic-related air pollution (TRAP). However, wildfire smoke (WFS) represents an important source of BC not often considered when using BC as a proxy for TRAP. Here, we examined the potential for WFS to bias TRAP exposure assessments based on BC measurements. Weekly integrated BC samples were collected across the Denver, CO region from May to November 2018. We collected 609 filters during our sampling campaigns, 35% of which were WFS-impacted. For each filter we calculated an average BC concentration. We assessed three GIS-based indicators of TRAP for each sampling location: annual average daily traffic within a 300 m buffer, the minimum distance to a highway, and the sum of the lengths of roadways within 300 m. Median BC concentrations were 9% higher for WFS-impacted filters (median = 1.14 μg/m3, IQR = 0.23 μg/m3) than nonimpacted filters (median = 1.04 μg/m3, IQR = 0.48 μg/m3). During WFS events, BC concentrations were elevated and expected spatial gradients in BC were reduced. We conducted a simulation study to estimate TRAP exposure misclassification as the result of regional WFS. Our results suggest that linear health effect estimates were biased away from the null when WFS was present. Thus, exposure assessments relying on BC as a proxy for TRAP may be biased by wildfire events. Alternative metrics that account for the influence of "brown" carbon associated with biomass burning may better isolate the effects of traffic emissions from those of other black carbon sources.

Cardiac myosin-binding protein C interaction with actin is inhibited by compounds identified in a high-throughput fluorescence lifetime screen

Cardiac myosin-binding protein C (cMyBP-C) interacts with actin and myosin to modulate cardiac muscle contractility. These interactions are disfavored by cMyBP-C phosphorylation. Heart failure patients often display decreased cMyBP-C phosphorylation, and phosphorylation in model systems has been shown to be cardioprotective against heart failure. Therefore, cMyBP-C is a potential target for heart failure drugs that mimic phosphorylation or perturb its interactions with actin/myosin. Here we have used a novel fluorescence lifetime-based assay to identify small-molecule inhibitors of actin-cMyBP-C binding. Actin was labeled with a fluorescent dye (Alexa Fluor 568, AF568) near its cMyBP-C binding sites; when combined with the cMyBP-C N-terminal fragment, C0-C2, the fluorescence lifetime of AF568-actin decreases. Using this reduction in lifetime as a readout of actin binding, a high-throughput screen of a 1280-compound library identified three reproducible hit compounds (suramin, NF023, and aurintricarboxylic acid) that reduced C0-C2 binding to actin in the micromolar range. Binding of phosphorylated C0-C2 was also blocked by these compounds. That they specifically block binding was confirmed by an actin-C0-C2 time-resolved FRET (TR-FRET) binding assay. Isothermal titration calorimetry (ITC) and transient phosphorescence anisotropy (TPA) confirmed that these compounds bind to cMyBP-C, but not to actin. TPA results were also consistent with these compounds inhibiting C0-C2 binding to actin. We conclude that the actin-cMyBP-C fluorescence lifetime assay permits detection of pharmacologically active compounds that affect cMyBP-C-actin binding. We now have, for the first time, a validated high-throughput screen focused on cMyBP-C, a regulator of cardiac muscle contractility and known key factor in heart failure.

Barriers and enablers to skill-mix in the oral health workforce: A systematic review

INTRODUCTION

In dentistry, the term "skill-mix" is used to describe the combinations of dentists and dental care professionals in delivering activities that are commonly established by their level of education, training and scope of practice. However, the literature has indicated an under-utilisation of skill-mix in the oral health care team. Further work is required to understand the poor uptake of skill-mix in oral health care and what could be done to address this issue.

OBJECTIVE

To identify and synthesise the available evidence on the barriers and enablers to skill-mix in the oral health workforce using a macro-, meso- and micro-level framework.

MATERIALS AND METHODS

The databases MEDLINE, CINAHL and Scopus between January 2010 to April 2020 were searched. Primary research studies published in English were included.

RESULTS

Thirty-two articles were included. Key barriers and enablers at each level of analysis were identified. Macro-level barriers and enablers included structural, regulatory and policy conditions and dental health care needs of populations. Meso-level barriers and enablers defined the parameters of service delivery and included workplace characteristics, referral systems and patterns, and workplace productivity and efficiency. Micro-level barriers and enablers pertained to the perceptions, attitudes, and social acceptability of stakeholders that affected the delivery of services.

CONCLUSION

Understanding the barriers and enablers from a multi-level framework requires further high-quality research to fully appreciate its importance in addressing health care needs within populations and increase generalisability to oral health settings.

O8: DIRECT MANIPULATION OF THE INTESTINAL MICROBIOME TO INFLUENCE POST-OPERATIVE OUTCOMES

Introduction

Distal feeding (DF) involves intubation of the distal limb of a loop ileostomy to feed with a prebiotic mix. Studies suggest that distally feeding patients following anterior resection prior to ileostomy closure may be beneficial as a form of bowel pre-habilitation. These pilot data examine the adaptive immune response to DF.

Method

Ten healthy controls with an intact GI tract were compared with 10 patients following rectal cancer resection and chemo/radiotherapy, prior to closure of ileostomy over 8 weeks of DF. We examined B and T cell memory responses from peripheral blood using cell proliferation assays. Cells were cultured with dead antigen to reflect the microbiota in the small and large bowel. Two negative and two positive controls were used to assess minimal and maximum cell proliferation.

Result

B cell responses prior to DF were increased in the defunctioned group compared to the normal controls to significance (p=0.0014). After 8 weeks of DF the groups were comparable. T cell responses to bacteria had significant differences in proliferation rate following DF commencement, CD4 week 0 vs 3 p=0.0001, week 3 vs 8 p=0.000034, CD8 week 0 vs 3 p=0.0001, week 3-8 p=0.00024). In individual patients, CD4 responses were shown to shift from responses to facultative aerobic species, to strict anaerobes.

Conclusion

These data suggest that distal feeding fundamentally resets peripheral circulating memory and it may be of use in pre-habilitating the bowel prior to restoration of continuity. Early clinical data suggests that distal feeding improves post-operative outcomes.

Take-home message

distal feeding is an easy pre-operative intervention that has a significant effect on cell proliferation and antigen response, which may contribute to improved post operative outcomes.