Sequential multiple assignment randomised trial to develop an adaptive mobile health intervention to increase physical activity in people poststroke in the community setting in Ireland: TAPAS trial protocol

INTRODUCTION

Stroke is the second-leading cause of death and disability globally. Participation in physical activity (PA) is a cornerstone of secondary prevention in stroke care. Given the heterogeneous nature of stroke, PA interventions that are adaptive to individual performance are recommended. Mobile health (mHealth) has been identified as a potential approach to supporting PA poststroke. To this end, we aim to use a Sequential Multiple Assignment Randomised Trial (SMART) design to develop an adaptive, user-informed mHealth intervention to improve PA poststroke.

METHODS AND ANALYSIS

The components included in the 12-week intervention are based on empirical evidence and behavioural change theory and will include treatments to increase participation in Structured Exercise and Lifestyle or a combination of both. 117 participants will be randomly assigned to one of the two treatment components. At 6 weeks postinitial randomisation, participants will be classified as responders or non-responders based on participants' change in step count. Non-responders to the initial treatment will be randomly assigned to a different treatment allocation. The primary outcome will be PA (steps/day), feasibility and secondary clinical and cost outcomes will also be included. A SMART design will be used to evaluate the optimum adaptive PA intervention among community-dwelling, ambulatory people poststroke.

ETHICS AND DISSEMINATION

Ethical approval has been granted by the Health Service Executive Mid-Western Ethics Committee (REC Ref: 026/2022). The findings will be submitted for publication and presented at relevant national and international academic conferences TRIALS REGISTRATION NUMBER: NCT05606770.

OptiCogs: feasibility of a multicomponent intervention to rehabilitate people with cognitive impairment post-stroke

BACKGROUND

Stroke is a leading cause of death and disability worldwide. Despite the prevalence and associated burden of cognitive impairment post-stroke, there is uncertainty regarding optimal cognitive rehabilitation for people post-stroke. This study aimed to assess whether a multicomponent intervention, called OptiCogs, is feasible, acceptable, and safe for people with cognitive impairment post-stroke. A secondary aim was to explore changes in cognitive function, fatigue, quality of life, physical function, and occupational performance, from pre-intervention to post-intervention.

METHODS

A feasibility study was conducted where people post-stroke with cognitive impairment enrolled in a 6-week multicomponent intervention. The primary outcomes recorded included response rate, recruitment rate, retention rate, adherence to the intervention protocol, adverse events, and acceptability of the intervention to people post-stroke. Secondary outcomes included (i) change in cognitive functioning using the Addenbrooke's Cognitive Examination III, (ii) fatigue using the Fatigue Severity scale, (iii) quality of life using the Stroke Specific Quality of Life scale (iv) physical function using the patient-reported outcomes measurement information system, and (v) patient-reported occupational performance using the Canadian Occupational Performance Measure. The Consolidated Standards of Reporting Trials extension reporting guidelines were followed, for pilot and feasibility studies, to standardize the conduct and reporting of this study.

RESULTS

The response rate was 10.9%. Nine eligible participants were enrolled during the 4-month recruitment period, with eight participants completing the entire 6-week intervention, as well as the pre- and post-intervention outcome measures. There were no reported adverse events. Participants were satisfied with the intervention and found it acceptable overall. Results of the secondary outcomes were promising for cognitive function (ACE III, pre: 63.3 ± 23.9 to post: 69 ± 24.6), fatigue (FSS, pre: 52.5 ± 7.3 to post: 45.6 ± 7.2), quality of life (SSQoL, pre: 131.0 ± 26.3 to post: 169.9 ± 15.3), physical function (PROMIS-PF, pre: 15.5 ± 6.3 to post: 15.8 ± 5.3), and occupational performance (COPM performance, pre: 9.3 ± 2.3 to post: 22.9 ± 4.2) and COPM satisfaction, pre: 9.9 ± 2.1 to post: 22.7 ± 3.5).

CONCLUSION

Preliminary results suggest low-modest recruitment and high retention rates for the OptiCogs intervention. Changes in cognitive function, fatigue, quality of life, and self-reported occupational performance show improvement from pre- to post-intervention. These potential benefits require further testing in a larger pilot trial.

TRIAL REGISTRATION

NCT05414539.

Evaluation of cardiovascular disease in the turner syndrome population in Northern Ireland

Background

There is higher frequency of both congenital heart disease and acquired cardiovascular conditions in patients with Turner syndrome. It is associated with increased early morbidity and mortality compared with the general population related mainly to cardiovascular complications.

Purpose

We sought to ascertain the prevalence and outcomes of cardiac abnormalities in patients with Turner syndrome in Northern Ireland.

Methods

Patients with Turner Syndrome who attended cardiology or gynaecology clinics in the Belfast Health and Social Care Trust were identified and demographic and clinical data were obtained.

Results

165 patients who had undergone cardiovascular assessment and imaging were identified. The mean age was 38±13 years. Hypercholesterolaemia was present in 49.7%, hypertension in 21% and diabetes mellitus in 15.2%. Patients with these cardiovascular risk factors were older compared to those without (Table 1). Ischaemic heart disease was present in 2.4%. Cardiac structural abnormalities were present in 52 patients (31.5%) and bicuspid aortic valve was the most common abnormality (23.6%). 9.1% of patients had a history of cardiothoracic surgery or catheter intervention and 1 patient had a previous Type A aortic dissection surgically repaired. The variety and frequency of cardiac structural abnormalities are listed in Table 2.

Conclusion

The prevalence of structural cardiac abnormalities and cardiovascular risk factors in Turner patients greatly exceeds that of the general population. This highlights the need for screening with cross sectional cardiac imaging plus early identification and management of cardiovascular risk factors.

Funding Acknowledgement

Type of funding sources: None.

Exploring the perspectives of key stakeholders on the design and delivery of a cognitive rehabilitation intervention for people post-stroke

Purpose

Stroke is a leading cause of death and disability worldwide. Despite the prevalence and associated burden of post-stroke cognitive impairment, there is uncertainty regarding optimum interventions to improve cognitive function in people post-stroke. The aim of this study is to explore the perspectives of key stakeholders on the design and development of a multidisciplinary intervention to rehabilitate cognitive deficits in people post-stroke.

Materials and methods

Audio-recorded, semi-structured interviews were employed with people post-stroke, caregivers, healthcare professionals and academics. All transcribed interviews were exported to NVivo software and analysed using reflexive thematic analysis.

Results

Thirty interviews were conducted across stakeholder groups including people post-stroke (n = 10), caregivers (n = 5), healthcare professionals (n = 14) and academics (n = 1). Four themes relevant to the design and development of the intervention were identified (i) engagement in the intervention must be meaningful, (ii) the point of readiness to engage, (iii) a familiar but flexible setting is key (iv) pragmatics of intervention delivery.

Conclusions

These findings present new perspectives across stakeholder groups on the design and delivery of an intervention to rehabilitate cognitive deficits in people post-stroke. Taken together with existing quantitative evidence, these findings will inform the development of a feasibility trial, examining patient and process outcomes, to rehabilitate cognitive deficits post-stroke.

Rehabilitation of Cognitive Deficits Poststroke: Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Despite the prevalence of cognitive impairment poststroke, there is uncertainty regarding interventions to improve cognitive function poststroke. This systematic review and meta-analysis evaluate the effectiveness of rehabilitation interventions across multiple domains of cognitive function.

METHODS

Five databases were searched from inception to August 2019. Eligible studies included randomized controlled trials of rehabilitation interventions for people with stroke when compared with other active interventions or standard care where cognitive function was an outcome.

RESULTS

Sixty-four randomized controlled trials (n=4005 participants) were included. Multiple component interventions improved general cognitive functioning (MD, 1.56 [95% CI, 0.69-2.43]) and memory (standardized MD, 0.49 [95% CI, 0.27-0.72]) compared with standard care. Physical activity interventions improved neglect (MD, 13.99 [95% CI, 12.67-15.32]) and balance (MD, 2.97 [95% CI, 0.71-5.23]) compared with active controls. Noninvasive brain stimulation impacted neglect (MD, 20.79 [95% CI, 14.53-27.04) and functional status (MD, 14.02 [95% CI, 8.41-19.62]) compared with active controls. Neither cognitive rehabilitation (MD, 0.37 [95% CI, -0.94 to 1.69]) nor occupational-based interventions (MD, 0.45 [95% CI, -1.33 to 2.23]) had a significant effect on cognitive function compared with standard care.

CONCLUSIONS

There is some evidence to support multiple component interventions, physical activity interventions, and noninvasive brain stimulation improving cognitive function poststroke. Findings must be interpreted with caution given the overall moderate to high risk of bias, heterogeneity of interventions, and outcome measures across studies.

Abstract TP67: Rehabilitation Of Cognitive Deficits Post-stroke: Systematic Review And Meta-analysis Of Randomised Controlled Trials Of Non-pharmacological Interventions

Background and Purpose: Stroke is among the leading causes of death and disability worldwide. Despite the prevalence of cognitive impairment post-stroke, there is uncertainty regarding the optimal type of rehabilitation intervention to improve cognitive functioning in people post-stroke. This systematic review and meta-analysis evaluates the effectiveness of rehabilitation interventions across multiple domains of cognitive function, namely, memory, attention, executive function, perception, apraxia and neglect, as well as general cognitive functioning.

Methods: Five databases were searched from inception to August 2019. Eligible studies included randomised controlled trials (RCTs) of rehabilitation interventions for people with stroke when compared to other active interventions or standard care where cognitive function was an outcome.

Results: Sixty-four RCTs (n= 4,005 participants) were included. Multiple component interventions improved general cognitive functioning (MD:1.56, 95% CI 0.69 to 2.43) and memory (SMD:0.49, 95% CI 0.27 to 0.72) compared to standard care. Physical activity interventions improved neglect (MD:13.99, 95% CI 12.67 to 15.32) and balance (MD:2.97 to 95% CI 0.71, 5.23) compared to active controls. Non-invasive brain stimulation (NIBS) impacted neglect (MD:20.79, 95% CI 14.53 to 27.04) and function (MD:14.02, 95% CI 8.41 to 19.62) compared to active controls. Neither cognitive rehabilitation (MD:0.37, 95% CI -0.94 to 1.69) or occupational-based interventions (MD:0.45, 95% CI -1.33 to 2.23) had a significant effect on cognitive function compared to standard care.

Conclusion: The evidence regarding the effects of rehabilitation interventions for improving cognitive deficits post-stroke is uncertain. Finings must be considered in the context of moderate and high risk of bias across various methodological domains. There is some evidence to support multiple component interventions, physical activity interventions and NIBS protocols. However, findings must be interpreted with caution given the heterogeneity of interventions and outcome measures used across studies.

241 IMPLEMENTATION OF AN INTRACEREBRAL CEREBRAL HAEMORRHAGE CARE BUNDLE

Background

Mortality for Intracerebral haemorrhage (ICH) is 31% (Irish National Audit Stroke, 2019). An ICH care bundle focusing on acute anticoagulation reversal, blood pressure lowering, and a neurosurgical care pathway was associated with improved survival. Translating evidence-based medicine into clinical practice is challenging. The aim of this study was to determine feasibility and outcomes of implementation of a care bundle.

Methods

An ICH care bundle was developed using an iterative process involving expert stakeholder review of the evidence-based literature. A pre-and-post quasi-experimental research design was employed to evaluate this intervention. Baseline data were collected before implementation (January 2016-June 2018). Implementation took place in a staged manner in a single university teaching hospital with multiple ‘Plan Do Study Act cycles’ (June 2018 to January 2021). Data on compliance, process measures and outcomes were collected.

Results

Systolic blood pressure (first 24-hours) and anticoagulant reversal were significantly better controlled post-implementation (χ2 (1, N = 91) = 5.34, P = 0.02), (χ2 (1, N = 25) = 5.85, P = 0.016), respectively. DNAR orders were significantly lower in the post-implementation group (χ2 (1, N = 25) = 5.85, P = 0.029). However, ‘Do Not Actively Resuscitate’ status did not significantly differ when accounting for low GCS as a surrogate measure for poor prognosis (χ2 (1, N = 34) = 0.00, P = 0.966). Modified Rankin Scale on discharge did not differ significantly pre-and-post-implementation (z = −0.075, P = 0.94). A greater proportion of patients survived in the post-implementation group; however, this was not statistically significant (χ2 (1, N = 133) = 0.77, P = 0.38). Length of stay significantly increased post implementation.

Conclusion

An ICH care bundle was developed based on expert stakeholder feedback. The feasibility of implementing this bundle of care was demonstrated in a real-world clinical practice setting. A cluster-randomized trial or a large registry study is the next step to evaluate the overall impact of this care bundle on patient outcomes.

247 BENCHMARKING STROKE SERVICES TO INFORM A QUALITY IMPROVEMENT INIAITIVE

Background

Stroke is a leading cause of death and disability in Ireland. Continuous audit and quality improvement is essential in the delivery of stroke care where the evidence basis is constantly changing. This helps to ensure the delivery of high quality stroke care and compliance with evidenced based guidelines. We aimed to assess stroke care at an Irish university teaching hospital.

Methods

Patients with a HIPE discharge diagnosis of Cerebral Infarction or Cerebral Haemorrhage (1st January-31st December 2019) were identified through both the HIPE database and the institutional Stroke Portal. Data was benchmarked against national (Irish National Audit of Stroke 2019) and international (6th SSNAP Annual Report; American Heart Association, 2013) practice and used to inform a quality improvement strategy.

Results

419 patients were included (56.6% male, median 57 years). 75.9% were aged 65 years or older. We compared favourably with Irish National Audit of Stoke national indicators on the following: thrombolysis rates-10%; median door to needle time-60 mins; stroke unit admissions- 78.5%; median duration of symptoms- 3 hours 6 minutes; swallow assessment- 81.1%; in-patient mortality- 10.5%; rates of institutionalisation- 3.8%. Areas identified for improvement were: thrombectomy rates- 1.9%; median length of stay- 12 days; door to imaging time- median 104 minutes; mood screening- 11.5%.

Conclusion

International and national data is a useful benchmark against which local hospitals can assess the quality of their service. By completing this quality improvement initiative we identified areas to target resources in our centre, including mood screening, swallow screening, thrombectomy rates, length of stay and time to neuroimaging. An ongoing quality improvement process using ‘PDSA’ methodology is being carried out with an annual audit to monitor progress.

235 THROMBOLYSIS DOSING AND WEIGHT ESTIMATION IN ACUTE STROKE: A SINGLE CENTRE AUDIT

Background

Stroke is a leading cause of death and disability. Thrombolysis with intravenous (IV) alteplase is the mainstay management of ischaemic stroke. It has a narrow therapeutic window with a high potential for adverse outcomes such as intracranial haemorrhage. The efficacy of alteplase is time and dose dependent with weight-based dosing. National clinical guidelines recommend a dose of 0.9 mg/kg, up to a maximum of 90 mg. (Irish Heart Foundation Council for Stroke 2015). In most hospitals in Ireland however, patients are not weighed prior to thrombolysis. Time pressure and lack of available suitable equipment are factors.

Methods

This retrospective clinical audit evaluated the dosing of alteplase, estimated and actual weight for a convenience sample of stroke thrombolysis patients treated between 2016–2020 at an Irish University Teaching Hospital.

Results

107 patients were audited (62 males, 45 females). Actual and estimated weights were available in 92/107. Weight was not documented (n = 15) due to severe stroke/palliative management (n = 6) or omission (n = 9). 21% (19/92) received the correct dose of 0.9 mg/kg. A further 54% (50/92) received a dose within the range of 0.81–0.99 mg/kg (±10%). 25% received a dose outside this range (> ± 10%). 11% (10/92) were under-thrombolysed and 14% (13/92) over-thrombolysed. 17/92 patients had an intracranial haemorrhage. 35% (n = 6/17) of patients who had an intracranial haemorrhage received a higher dose of thrombolysis (>10%).

Conclusion

A quarter of patients received inappropriate dosing of alteplase that was outside the range of ±10% of 0.9 mg/kg. While stroke thrombolysis must be completed urgently, an accurate weight should be determined to avoid errors in dosing. A process evaluation of stroke thrombolysis would provide information on how best to incorporate an objective means of weight measurement without delaying treatment.

Coeliac disease enteropathy and symptoms may be aggravated by angiotensin receptor blockers in patients on a gluten-free diet

Background

Angiotensin receptor blocker‐associated enteropathy (ARB‐e) is an increasingly recognised clinical entity with symptoms and histological findings identical to coeliac disease (CD). There is evidence to suggest immune‐mediated mucosal injury in ARB‐e with a high prevalence of DQ2/DQ8; however, as IgA anti‐tissue transglutaminase (anti‐TTG) is usually negative, an insult other than TTG‐mediated injury is suspected. The impact of ARBs on disease activity in patients with CD is not known.

Objective

To assess the effect of ARB exposure on patients with established CD.

Methods

A patient record search of 1142 individual patients attending a dedicated coeliac clinic from 2010 to the present identified 59 patients treated with ARB. Those with CD confirmed by serology (TTG + ve/EMA + ve) and histopathology (Marsh criteria) were included (n = 40, 0.52%). Data collected included disease duration, compliance with gluten‐free diet (GFD), reported symptoms (diarrhoea, weight loss and abdominal pain), surrogate markers of absorption (Vitamin D, Iron, Calcium and Haemoglobin), in addition to anti‐TTG titre and histological grade at last follow up. Patients were age and sex‐matched in a 1:2 ratio with CD patients not taking ARBs (controls), with comparable rates of disease duration and compliance with GFD.

Results

The ARB and control groups were matched in terms of age (mean 66.2 years) and gender (female 63%). Strict compliance with GFD was reported in 55% and 56%, respectively. Persistent symptoms were reported in 10/40 (25%) of the ARB group compared with 7/82 (9%) of controls (p = 0.0181). There were lower rates of mucosal healing (Marsh grade 0) in the ARB group (36% n = 11) compared to controls (55%, n = 33). There was no significant difference in anti‐TTG titres. Surrogate markers of absorption were comparable across the groups, except for Vitamin D which was lower in those taking olmesartan (p = 0.0015).

Conclusions

ARBs may aggravate the enteropathy and lead to increased symptoms in patients with bone fide diagnosed CD following a GFD.

Summarise the estabished knowledge on this subject

Angiotensin receptor blocker‐associated enteropathy (ARB‐e) is an increasingly recognised clinical entity with symptoms and histological findings identical to coeliac disease (CD).

The exact cause of mucosal injury in ARB‐e is unknown however there is evidence to suggest immune‐mediated mucosal injury in ARB‐e with a high prevalence of DQ2/DQ8, however as anti‐tissue transglutaminase (TTG) is usually negative, an insult other than TTG‐mediated injury is suspected. The impact of ARBs on disease activity in patients with CD is not known.

What are the significance and/or new findins of this study?

Coeliac patients who take ARBs are more likely to have persistent symptoms and lower rates of mucosal healing than their age‐matched coeliac controls. This observation appears to be independent of TTG mediated injury, akin to that reported in non‐coeliac populations.

ARB use in patients with established coeliac disease may confound the interpretation of clinical and histological response to a gluten‐free diet.

505 INTERLEUKIN-6, C-REACTIVE PROTEIN, FIBRINOGEN, AND RISK OF RECURRENCE AFTER ISCHEMIC STROKE: SYSTEMATIC REVIEW AND META-ANALYSIS

Background

Recent randomised trials showed benefit for anti-inflammatory therapies in coronary disease but excluded stroke. The prognostic value of blood inflammatory markers after stroke is uncertain and guidelines do not recommend their routine measurement for risk stratification.

Methods

We performed a systematic review and meta-analysis of studies investigating the association of C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen and risk of recurrent stroke or major vascular events (MVEs). We searched EMBASE and Ovid Medline until 10/1/19. Random-effects meta-analysis was performed for studies reporting comparable effect measures.

Results

Of 2,515 reports identified, 39 met eligibility criteria (IL-6, n = 10; CRP, n = 33; fibrinogen, n = 16). An association with recurrent stroke was reported in 12/26 studies (CRP), 2/11 (fibrinogen) and 3/6 (IL-6). On random-effects meta-analysis of comparable studies, CRP was associated with an increased risk of recurrent stroke [pooled hazard ratio (HR) per 1 standard-deviation (SD) increase in loge-CRP (1.14, 95% CI 1.06-1.22, p < 0.01)] and MVEs (pooled HR 1.21, CI 1.10-1.34, p < 0.01). Fibrinogen was also associated with recurrent stroke (HR 1.26, CI 1.07-1.47, p < 0.01) and MVEs (HR 1.31, 95% CI 1.15-1.49, p < 0.01). Trends were identified for IL-6 for recurrent stroke (HR per 1-SD increase 1.17, CI 0.97-1.41, p = 0.10) and MVEs (HR 1.22, CI 0.96-1.55, p = 0.10).

Conclusion

Despite evidence suggesting an association between inflammatory markers and post-stroke vascular recurrence, substantial methodological heterogeneity was apparent between studies. Individual-patient pooled analysis and standardisation of methods are needed to determine the prognostic role of blood inflammatory markers and to improve patient selection for randomised trials of inflammatory therapies.

Sargramostim (rhu GM-CSF) Improves Survival of Non-Human Primates with Severe Bone Marrow Suppression after Acute, High-Dose, Whole-Body Irradiation

Exposure to acute, high-dose, whole-body ionizing radiation results in bone marrow failure (hematopoietic acute radiation syndrome with resultant infection, bleeding, anemia, and increased risk of death). Sargramostim (yeast-derived rhu GM-CSF), a yeast-derived, molecularly cloned, hematopoietic growth factor and pleiotropic cytokine supports proliferation, differentiation, maturation and survival of cells of several myeloid lineages. We evaluated the efficacy of sargramostim in non-human primates (rhesus macaques) exposed to whole-body ionizing radiation at a 50-60% lethal dose. The primary end point was day 60 survival. Non-human primates received daily subcutaneous sargramostim (7 mcg/kg/day) or control. To reflect the anticipated setting of a nuclear or radiologic event, treatment began 48 h postirradiation, and non-human primates received only moderate supportive care (no whole blood transfusions or individualized antibiotics). Sargramostim significantly increased day 60 survival to 78% (95% confidence interval, 61-90%) vs. 42% (26-59%; P = 0.0018) in controls. Neutrophil, platelet and lymphocyte recovery rates were accelerated and infection rates decreased. Improved survival when sargramostim was started 48 h postirradiation, without use of intensive supportive care, suggests sargramostim may be effective in treating humans exposed to acute, high-dose whole-body, ionizing radiation in a scenario such as a mass casualty event.

Audit of inpatient acute stroke services in a university teaching hospital, 2020

BACKGROUND

We aimed to assess stroke care at an Irish university teaching hospital and benchmark against national (Irish National Audit of Stroke 2019) and international (6th SSNAP Annual Report; American Heart Association, 2013) practice to inform a quality improvement strategy.

METHODS

All patients with a HIPE discharge diagnosis of Cerebral Infarction or Cerebral Haemorrhage (1 January to 31 December 2019) were identified through both the HIPE database and the institutional Stroke Portal.

RESULTS

A total of 419 patients were included (56.6% male, mean age 72). The following were comparable/better than findings from the Irish National Audit of Stroke: median duration of symptoms-3 h 6 min; 10% received thrombolysis; median door to needle time-60 min; 78.5% admitted to the stroke unit; 81.1% had a swallow assessment; in-patient mortality rate-10.5%; rates of institutionalisation-3.8%. The following areas were below the national average: overall door to imaging time-median 104 min; rate of thrombectomy-4%; 11.5% had mood screening; median length of stay- 12 days.

DISCUSSION

Using national and international audit data as an institutional benchmark provides a standard with which a service can be compared to highlight areas for improvement. We identified mood screening, swallow screening, thrombectomy rates, length of stay and time to neuroimaging as key areas for development in our centre. We are currently completing a process map to determine cause, effect, and solutions, and we will implement change using PDSA methodology as per SQUIRE 2.0 guidelines. The results of the re-audit cycle for 2020 will be available in 2021 to inform our progress. Ongoing quality improvement is essential for stroke care, which is a leading cause of death and disability in Ireland.

Interleukin-6, C-reactive protein, fibrinogen, and risk of recurrence after ischaemic stroke: Systematic review and meta-analysis

Background

Recent randomised trials showed benefit for anti-inflammatory therapies in coronary disease but excluded stroke. The prognostic value of blood inflammatory markers after stroke is uncertain and guidelines do not recommend their routine measurement for risk stratification.

Methods

We performed a systematic review and meta-analysis of studies investigating the association of C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen and risk of recurrent stroke or major vascular events (MVEs). We searched EMBASE and Ovid Medline until 10/1/19. Random-effects meta-analysis was performed for studies reporting comparable effect measures.

Results

Of 2,515 reports identified, 39 met eligibility criteria (IL-6, n = 10; CRP, n = 33; fibrinogen, n = 16). An association with recurrent stroke was reported in 12/26 studies (CRP), 2/11 (fibrinogen) and 3/6 (IL-6). On random-effects meta-analysis of comparable studies, CRP was associated with an increased risk of recurrent stroke [pooled hazard ratio (HR) per 1 standard-deviation (SD) increase in log_e-CRP (1.14, 95% CI 1.06-1.22, p < 0.01)] and MVEs (pooled HR 1.21, CI 1.10-1.34, p < 0.01). Fibrinogen was also associated with recurrent stroke (HR 1.26, CI 1.07-1.47, p < 0.01) and MVEs (HR 1.31, 95% CI 1.15-1.49, p < 0.01). Trends were identified for IL-6 for recurrent stroke (HR per 1-SD increase 1.17, CI 0.97-1.41, p = 0.10) and MVEs (HR 1.22, CI 0.96-1.55, p = 0.10).

Conclusion

Despite evidence suggesting an association between inflammatory markers and post-stroke vascular recurrence, substantial methodological heterogeneity was apparent between studies. Individual-patient pooled analysis and standardisation of methods are needed to determine the prognostic role of blood inflammatory markers and to improve patient selection for randomised trials of inflammatory therapies.

Anticoagulant Reversal Strategies in the Emergency Department Setting: Recommendations of a Multidisciplinary Expert Panel

Bleeding is the most common complication of anticoagulant use. The evaluation and management of the bleeding patient is a core competency of emergency medicine. As the prevalence of patients receiving anticoagulant agents and variety of anticoagulants with different mechanisms of action, pharmacokinetics, indications, and corresponding reversal agents increase, physicians and other clinicians working in the emergency department require a current and nuanced understanding of how best to assess, treat, and reverse anticoagulated patients. In this project, we convened an expert panel to create a consensus decision tree and framework for assessment of the bleeding patient receiving an anticoagulant, as well as use of anticoagulant reversal or coagulation factor replacement, and to address controversies and gaps relevant to this topic. To support decision tree interpretation, the panel also reached agreement on key definitions of life-threatening bleeding, bleeding at a critical site, and emergency surgery or urgent invasive procedure. To reach consensus recommendations, we used a structured literature review and a modified Delphi technique by an expert panel of academic and community physicians with training in emergency medicine, cardiology, hematology, internal medicine/thrombology, pharmacology, toxicology, transfusion medicine and hemostasis, neurology, and surgery, and by other key stakeholder groups.

80 Sleeping Beauty

Background

The artery of Percheron is a rare anatomic variant of arterial supply to the paramedian thalamus and rostral midbrain, and occlusion of the artery of Percheron results in bilateral paramedian thalamic infarcts with or without midbrain involvement. Early diagnosis of artery of Percheron infarction can be challenging because it is infrequent and early computed tomography or magnetic resonance imaging may be negative. Thus, it can be confused with other neurological conditions such as tumours and infections.

Methods

This is a retrospective case study of a gentleman admitted to a teaching Hospital in Limerick and diagnosed with an artery of Percheron infarction. Medical records and the neuro-radiological database were reviewed, and the diagnosis was made based on typical symptoms and radiological findings of artery of Percheron infarction.

Results

We report the case of a gentleman who was found unconscious in his car on the roadside during the daytime. He had a decreased GCS and upon arrival in the Emergency Department he was intubated and transferred to ITU

The initial head computed tomography performed on admission was reported as unremarkable. Bilateral ischemia in the paramedian thalamic nuclei was documented on a follow-up computed tomography on day 24 after hospitalization.

He was extubated after 24 hours. He made a full recovery and was discharged home on day 5.

Conclusion

Artery of Percheron infarcts are rare. The radiological diagnosis can initially often be judged as normal and in combination with variability in the neurological symptoms it is a rather difficult condition to diagnose.

Simulations of Cellulose Synthesis Initiation and Termination in Bacteria

The processivity of cellulose synthesis in bacterial cellulose synthase (CESA) was investigated using molecular dynamics simulations and the hybrid quantum mechanics and molecular mechanics approach. Our results suggested that cellulose synthesis in bacterial CESA can be initiated with H₂O molecules. The chain length or degree of polymerization (DOP) of the product cellulose is related to the affinity of the cellulose chain to the transmembrane tunnel of the enzyme. This opens up the possibility of generating mutants that would produce cellulose chains with desired chain lengths that could have applications in the biofuel and textile fields that depend on the DOP of cellulose chains.

Well leg compartment syndrome in trauma surgery - femoral shaft fracture treated by femoral intramedullary nailing in the hemilithotomy position: case series and review of the literature

Well leg compartment syndrome (WLCS) is a rare complication which can occur following urological, gynecological, general surgical or orthopedic surgeries carried out with the lower limb in the hemilithotomy position. WLCS is associated with significant morbidity and mortality because delay in diagnosis and treatment can lead to loss of function and even life-threatening complications. During orthopedic surgeries on a traction table, such as femoral nailing, the contralateral “well leg” is often placed in the hemilithotomy position, thus facilitating the use of fluoroscopy. This position (also named the Lloyd-Davis position) consists of hip flexion, abduction, external rotation and knee flexion. We present the cases of two teenaged patients who underwent femoral nailing on an extension table of a femoral fracture and developed WLCS. We also present a review of the literature and a discussion of the pathophysiology, risk factors and treatment of this condition. Clinicians need to be aware of the risk factors for WLCS and have high index of suspicion. Further studies looking at the risks, benefits and feasibility of ways to reduce this risk are required.

The impact of an Emergency Medical Technician basic course prior to medical school on medical students

BACKGROUND

Previous research on Emergency Medical Technician (EMT) programs as an early clinical experience indicates that medical students' confidence in patient care and team-building skills increases with participation. However, very little is known about the unplanned, long-term effects of EMT courses on medical students once they enter medical school.

OBJECTIVES

This study examined the immediate outcomes produced by the month-long summer EMT course and the unplanned outcomes that students reported 1 year later.

METHODS

Pre/postsurveys were collected on all 25 students who graduated from the EMT course offered before their first year. These survey data were analyzed using a paired-samples t test. A subset of students (N = 14) consented to taking a survey and be interviewed on the lasting impact of their EMT experience. Interviews were conducted 10 months after the 2016 cohort completed the EMT course and at 22 months for the 2015 cohort. They were audio-recorded, transcribed, and analyzed using inductive content analysis.

RESULTS

Survey results indicated that students' confidence in patient care and team-building skills increased significantly for all identified skills at the P < 0.05 level. Overall confidence in patient care increased 1.5 points (P = 0.001) on 1-4 Likert-type scale. Overall confidence in team-building skills increased at 0.7 points (P = 0.01). Qualitative analysis of interviews discovered four themes, including the retention and transferability of practical skills, a developed understanding of team communication, comfort with patient interactions, and the development of a framework for assessing patients' needs. Students applied the EMT skills in various extracurricular volunteering experiences and in clinical skills courses.

CONCLUSIONS

This study concludes that EMT programs have both immediate and lasting effects that seem to assist students with making sense of and navigating other learning opportunities. Specifically, EMT courses offered to students prior to their entry into medical school may help orient them to team-based health care and triaging patient care.

Burnout in the Emergency Department hospital staff at Cork University Hospital

BACKGROUND AND AIMS

Healthcare professionals are exposed to high levels of stress in the course of their profession and are particularly susceptible to experiencing burnout. In the USA, burnout among physicians is highly prevalent, exceeding that of other workers. Little literature has been published describing burnout prevalence in the context of the Irish emergency healthcare population. We conducted a survey to determine burnout in the Emergency Department hospital staff at Cork University Hospital (CUH).

METHODS

This is a prospective inclusive cross-sectional study assessing burnout with the Oldenburg Burnout Inventory (OLBI). Over 90 staff (physicians, nurses, administrators, radiographers, care assistants, and porters) participated. Provider demographic differences were documented and comparisons of burnout were made between this study population and previous international studies.

RESULTS

Sixty-three percent of administrators (8), 100% of care assistants (3), 78% of nurses (50), 70% of physicians (23), 67% of porters (3), and 80% of radiographers (10) met the criteria for burnout (75% overall). Burnout was significantly associated with a history of depression (p = 0.030). The burnout rates were not significantly different between professions (p = 0.77), age groups (p = 0.078), years working in the ED (p = 0.16), or gender (p = 0.46).

DISCUSSION AND CONCLUSIONS

Burnout is very common in the Emergency Department at CUH. Approximately three out of four staff met the cutoff for burnout. Self-reported depression was also significantly associated with burnout.

Enhancing acute stroke services: a quality improvement project

Background

In a busy stroke centre in Ireland, care for acute stroke was provided by a mixture of general physicians. In acute ischaemic stroke, speed is essential for good outcomes.

Aim

To improve acute stroke services and decrease door-to-needle (DTN) time to less than 60 min by December 2016 in patients with acute ischaemic stroke who are eligible for intravenous thrombolysis.

Design: A quality improvement (QI) project was undertaken in a 438 bed, acute, university hospital.

Methods

Mixture of qualitative and quantitative data collected. A process map and driver diagram were created. Interventions tested with Plan-Do-Study-Act cycles. Times compared between July and December 2015, January and July 2016, July and December 2016, when a new stroke team and pathway were introduced.

Results

Between July and December 2015, the total number of ischaemic strokes was 216. 17 were thrombolysed (7.8%). Median door-to-CT (DTCT) time was 36 min (range 21–88). Median DTN time was 99 min (range 52–239). Between July and December 2016, there were 214 ischaemic strokes. 29 were thrombolysed (13.5%). 9 were seen directly by the stroke team during normal hours. With stroke team involvement, median DTCT time was 34 min (range 14–60) and DTN time was 43.5 min (range 24–65).

Conclusions

This project led to a significant and sustained improvement in acute stroke care in our hospital with the use of quality improvement techniques. A comprehensive protocol, recurrent and ongoing staff education, and good communication helped to mitigate delays and further enhance care provided to patients presenting with stroke. The approach described may be valuable to the improvement of other services.’

Outcomes of endovascular treatment for acute large-vessel ischaemic stroke more than 6 h after symptom onset

BACKGROUND AND OBJECTIVES

Benefit from endovascular thrombectomy (EVT) for large-vessel occlusion (LVO) acute ischaemic stroke (AIS) is well demonstrated. Furthermore, emerging evidence supports efficacy in appropriately selected patients treated beyond current recommendations of 6 h. We evaluated clinical outcomes in patients undergoing late EVT at our institution.

METHODS

Retrospective review of prospectively collected clinical database on 355 patients who underwent EVT for LVO AIS. Data collected consisted of patient demographics, radiological findings and outcome details. Outcomes, including 90-day functional status, recanalization, symptomatic intracranial haemorrhage (sICH) and 90-day mortality, for patients undergoing EVT <6 h, >6 h, and >7.3 h, were compared.

RESULTS

A total of 355 patients underwent EVT for LVO AIS at our institution during the review period, with 74 (21%) patients treated ≥6 h from symptom onset. Successful recanalization was achieved in 285 (80%) patients, with 228 (81%) achieving a mTICI ≥2b in the <6 h group, and 57 (77%) in the >6 h group (P = 0.429). Ninety-day functional independence (mRS 0-2) was achieved in 162 (46%) patients, with 130 (46%) achieving a mRS of 0-2 in the <6 h group, and 32 (43%) in the >6 h group (P = 0.643). No significant differences were found in rates of sICH or 90-day mortality. No significant differences in functional independence, recanalization rates, sICH or mortality were identified in patients treated with EVT >7.3 h compared to <7.3 h.

CONCLUSIONS

In appropriately selected patients, EVT >6 h was associated with comparable outcomes to those treated <6 h. These data support a physiological approach to patient selection.

Abstract P3-04-05: Identification of SAR439859, an orally bioavailable selective estrogen receptor degrader (SERD) that has strong antitumor activity in wild-type and mutant ER+ breast cancer models

Estrogen receptor positive (ER+) breast cancer accounts for 70% of all breast cancers and is primarily treated with endocrine therapy. Approximately 40% of patients on endocrine therapy will become resistant via a number of mechanisms. There is evidence that in many cases ER continues to play a central role, including mutations in ER leading to a constitutively active receptor. Estrogen receptor degraders like fulvestrant are effective in shutting down ER signaling; however, poor pharmaceutical properties limit fulvestrant clinical activity and prevent it from achieving maximum receptor blockade.

We describe the discovery of SAR439859, a novel, orally bioavailable SERD that is a potent antagonist and degrader of ER both in vitro and in vivo. SAR439859 has robust activity in multiple ER+ breast cancer cell lines including cells that are resistant to tamoxifen as well as cell lines harboring ER mutants. Across a large panel of ER+ cells, SAR439859 demonstrated broad and superior ER degradation activity than most SERDs undergoing clinical testing. This leads to a profound inhibition of ER signaling, better inhibition of cell growth and results in improved in vivo efficacy. SAR439859 demonstrated tumor regression in all ER+ BC models including MCF7-ESR1 mutant-Y537S model, as well as patient-derived xenograft model that is resistant to endocrine therapies. Furthermore, SAR439859 displays limited cross-resistance with other class of SERDs.

Taken together, these results suggest that SAR439859 would be of therapeutic benefit in metastatic BC setting for patients harboring wild type or mutant ER. SAR439859 is being advanced toward the clinic.

Citation Format: Shomali M, Cheng J, Koundinya M, Weinstein M, Malkova N, Sun F, Hebert A, Cindachao M, Hoffman D, McManus J, Levit M, Pollard J, Vincent S, Besret L, Adrian F, Winter C, El-Ahmad Y, Halley F, Hsu K, Lager J, Garcia-Echeverria C, Bouaboula M. Identification of SAR439859, an orally bioavailable selective estrogen receptor degrader (SERD) that has strong antitumor activity in wild-type and mutant ER+ breast cancer models [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-04-05.

Youth Violence Stories Focus on Events, Not Causes

A content analysis of three major California newspapers shows that routine coverage about youth crimes fails to provide context to help readers make sense of such events.

Unmasking the elusive giant: an unusual case presenting as third nerve palsy in a patient with scleroderma

We report a case of an 80-year-old woman being treated with rituximab and maintenance corticosteroids for long-standing scleroderma who presented with right-sided third nerve palsy. Radiological investigations including CT, MRI and MR angiography of the brain were unremarkable. The patient was discharged with a diagnosis of probable microvascular third nerve palsy but was readmitted 1 week later with total visual loss in her left eye. Despite the absence of diagnostic clinical signs, giant cell arteritis (GCA) was suspected, and she was started on intravenous corticosteroids. Left temporal artery biopsy subsequently confirmed histological findings diagnostic of GCA. Unfortunately, she remained blind in the left eye.

Predicting dredging-associated effects to coral reefs in Apra Harbor, Guam - Part 2: Potential coral effects

Coral reefs are in decline worldwide due to anthropogenic stressors including reductions in water and substratum quality. Dredging results in the mobilization of sediments, which can stress and kill corals via increasing turbidity, tissue damage and burial. The Particle Tracking Model (PTM) was applied to predict the potential impacts of dredging-associated sediment exposure on the coral reef ecosystems of Apra Harbor, Guam. The data were interpreted using maps of bathymetry and coral abundance and distribution in conjunction with impact parameters of suspended sediment concentration (turbidity) and sedimentation using defined coral response thresholds. The results are presented using a "stoplight" model of negligible or limited impacts to coral reefs (green), moderate stress from which some corals would be expected to recover while others would not (yellow) and severe stress resulting in mortality (red). The red conditions for sediment deposition rate and suspended sediment concentration (SSC) were defined as values exceeding 25 mg cm(-2) d(-1) over any 30 day window and >20 mg/l for any 18 days in any 90 day period over a column of water greater than 2 m, respectively. The yellow conditions were defined as values >10 mg cm(-2) d(-1) and <25 mg cm(-2) d(-1) over any 30 day period, and as 20% of 3 months' concentration exceeding 10 mg/l for the deposition and SSC, respectively. The model also incorporates the potential for cumulative effects on the assumption that even sub-lethal stress levels can ultimately lead to mortality in a multi-stressor system. This modeling approach can be applied by resource managers and regulatory agencies to support management decisions related to planning, site selection, damage reduction, and compensatory mitigation.

Selective Targeting of a Novel Epsin-VEGFR2 Interaction Promotes VEGF-Mediated Angiogenesis

RATIONALE

We previously reported that vascular endothelial growth factor (VEGF)-induced binding of VEGF receptor 2 (VEGFR2) to epsins 1 and 2 triggers VEGFR2 degradation and attenuates VEGF signaling. The epsin ubiquitin interacting motif (UIM) was shown to be required for the interaction with VEGFR2. However, the molecular determinants that govern how epsin specifically interacts with and regulates VEGFR2 were unknown.

OBJECTIVE

The goals for the present study were as follows: (1) to identify critical molecular determinants that drive the specificity of the epsin and VEGFR2 interaction and (2) to ascertain whether such determinants were critical for physiological angiogenesis in vivo.

METHODS AND RESULTS

Structural modeling uncovered 2 novel binding surfaces within VEGFR2 that mediate specific interactions with epsin UIM. Three glutamic acid residues in epsin UIM were found to interact with residues in VEGFR2. Furthermore, we found that the VEGF-induced VEGFR2-epsin interaction promoted casitas B-lineage lymphoma-mediated ubiquitination of epsin, and uncovered a previously unappreciated ubiquitin-binding surface within VEGFR2. Mutational analysis revealed that the VEGFR2-epsin interaction is supported by VEGFR2 interacting specifically with the UIM and with ubiquitinated epsin. An epsin UIM peptide, but not a mutant UIM peptide, potentiated endothelial cell proliferation, migration and angiogenic properties in vitro, increased postnatal retinal angiogenesis, and enhanced VEGF-induced physiological angiogenesis and wound healing.

CONCLUSIONS

Distinct residues in the epsin UIM and VEGFR2 mediate specific interactions between epsin and VEGFR2, in addition to UIM recognition of ubiquitin moieties on VEGFR2. These novel interactions are critical for pathophysiological angiogenesis, suggesting that these sites could be selectively targeted by therapeutics to modulate angiogenesis.

Motif mimetic of epsin perturbs tumor growth and metastasis

Tumor angiogenesis is critical for cancer progression. In multiple murine models, endothelium-specific epsin deficiency abrogates tumor progression by shifting the balance of VEGFR2 signaling toward uncontrolled tumor angiogenesis, resulting in dysfunctional tumor vasculature. Here, we designed a tumor endothelium-targeting chimeric peptide (UPI) for the purpose of inhibiting endogenous tumor endothelial epsins by competitively binding activated VEGFR2. We determined that the UPI peptide specifically targets tumor endothelial VEGFR2 through an unconventional binding mechanism that is driven by unique residues present only in the epsin ubiquitin-interacting motif (UIM) and the VEGFR2 kinase domain. In murine models of neoangiogenesis, UPI peptide increased VEGF-driven angiogenesis and neovascularization but spared quiescent vascular beds. Further, in tumor-bearing mice, UPI peptide markedly impaired functional tumor angiogenesis, tumor growth, and metastasis, resulting in a notable increase in survival. Coadministration of UPI peptide with cytotoxic chemotherapeutics further sustained tumor inhibition. Equipped with localized tumor endothelium-specific targeting, our UPI peptide provides potential for an effective and alternative cancer therapy.

Crustal fluid and ash alteration impacts on the biosphere of Shikoku Basin sediments, Nankai Trough, Japan

We present data from sediment cores collected from IODP Site C0012 in the Shikoku Basin. Our site lies at the Nankai Trough, just prior to subduction of the 19 Ma Philippine Sea plate. Our data indicate that the sedimentary package is undergoing multiple routes of electron transport and that these differing pathways for oxidant supply generate a complex array of metabolic routes and microbial communities involved in carbon cycling. Numerical simulations matched to pore water data document that Ca(2+) and Cl(1-) are largely supplied via diffusion from a high-salinity (44.5 psu) basement fluid, which supports the presence of halophile Archean communities within the deep sedimentary package that are not observed in shallow sediments. Sulfate supply from basement supports anaerobic oxidation of methane (AOM) at a rate of ~0.2 pmol cm(-3) day(-1) at ~400 mbsf. We also note the disappearance of δ-Proteobacteria at 434 mbsf, coincident with the maximum in methane concentration, and their reappearance at 463 mbsf, coinciding with the observed deeper increase in sulfate concentration toward the basement. We did not, however, find ANME representatives in any of the samples analyzed (from 340 to 463 mbsf). The lack of ANME may be due to an overshadowing effect from the more dominant archaeal phylotypes or may indicate involvement of unknown groups of archaea in AOM (i.e., unclassified Euryarchaeota). In addition to the supply of sulfate from a basement aquifer, the deep biosphere at this site is also influenced by an elevated supply of reactive iron (up to 143 μmol g(-1)) and manganese (up to 20 μmol g(-1)). The effect of these metal oxides on the sulfur cycle is inferred from an accompanying sulfur isotope fractionation much smaller than expected from traditional sulfate-reducing pathways. The detection of the manganese- and iron-reducer γ-Proteobacteria Alteromonas at 367 mbsf is consistent with these geochemical inferences.

Wartime toxicology: evaluation of a military medical toxicology telemedicine consults service to assist physicians serving overseas and in combat (2005-2012)

Those medical providers deployed to remote countries and tasked with caring for military personnel must diagnose and treat diseases and nonbattle injuries that result from exposures rarely seen in developed countries. Military providers must also function with limited resources and a lack of access to physician specialists, to include medical toxicologists. There have been limited published approaches to addressing this clinical gap for medical toxicology. To address this void, the US Army Medical Department deployed an electronic mail telemedicine system to provide teleconsultations for remote health-care providers worldwide, including Iraq and Afghanistan. This study aimed to describe the types and the frequency of toxicology teleconsultation and consultant responses using electronic mail to assist physicians serving in resource-limited locations. This was a retrospective observational study in which an unblinded data extractor independently reviewed all medical toxicology email consultations. Using a previously developed data collection worksheet, the extractor recorded the type of question asked by the consultant (overdose case, envenomation, occupational exposure, etc.) and the duration of time from when the teleconsultation was placed until the consultant replied. The extractor also recorded if the patient was adult or pediatric and if the patient was US military, US contractor, or local national. The extractor also recorded how often the toxicologist provided the consulting physician with information, resources, or protocols to aid in the management of future cases. In addition, for clinical teleconsultations, the extractor documented the frequency that the consulted toxicologist (i) provided a differential diagnosis or specific diagnosis, (ii) provided specific management guidelines for a patient, and (iii) recommended to evacuate or not evacuate a patient. The results were analyzed using descriptive statistics. Of the 99 consultations evaluated, the most common consultation was for snake envenomation and antivenom recommendations (n = 23, 23 %) followed by accidental chemical exposures (n = 14, 14 %), drug testing (n = 13, 13 %), and substance abuse (n = 10, 10 %). In 41 % of consults, the toxicologist provided a differential diagnosis or specific diagnosis, and in 60 % of cases, the toxicologist provided specific management or evaluation guidelines. In 11 % of cases, the toxicologist recommended for or against evacuation of the patient. In 25 % of consults, the toxicologist provided the consulting physician with information, resources, or protocols to aid in the management of future cases. The most frequent consultations for the military telemedicine consultation service were for direct patient cases, specifically snake envenomation management and accidental chemical exposures. Our results may be used to educate physicians prior to military deployment or international humanitarian efforts and to create toxicology clinical guidelines for remote locations. Expansion of the current military teleconsultation program capabilities to include video teleconsultation may improve the effectiveness of military medical toxicology teleconsultation.

Abstract 307: Role of Epsins in Regulating LPS-Induced Sepsis

Background: Sepsis is caused by a deleterious host response to infection, which is primarily responsible for further injury of host tissue and cause of organ dysfunction. However, the underlying regulatory mechanisms are still not fully understood. Our goal is to define the novel role of epsins in regulating sepsis.

Methods and Results: We engineered global (iDKO) and endothelial cell-specific (EC-iDKO) epsin deficient mice. When treated with lethal dose of LPS, epsin deficient mice were completely protected from LPS-induced septic death. These mice also exhibited decreased expression of tissue damage biomarkers and recruitment of neutrophils and macrophages to lungs compared to wild type (WT) suggesting that epsin deficiency mitigates sepsis induced tissue injury. Epsin deficiency further reduced expression of proinflammatory cytokines and adhesion molecules in the lungs suggesting that loss of epsin attenuates LPS-induced inflammatory responses. TAT complex production was also decreased in iDKO mice compared to WT indicating diminished coagulation and thrombin production. Knocking down of epsins in HUVECs resulted in reduced cell surface Tissue Factor (TF) expression. Loss of epsin in mice protected against loss of Thrombomodulin (TM), which is downregulated by sepsis. Mechanistically, loss of epsin inhibited LPS-induced TM internalization, while LPS treatment induced the ubiquitination of TM. Furthermore, co-IP of full length epsin 1 or epsin 1 without the UIM domain and TM demonstrated that UIM is required for the interaction between epsin 1 and TM. Collectively, we show that epsin-deficiency upregulates TM surface protein expression by preventing its internalization and subsequent degradation and inhibits heightened TF expression and activation under chronic inflammatory conditions such as that induced by LPS exposure.

Conclusions: Our findings demonstrate that epsins play a key role in regulating coagulation and provide fundamental information on the modulation of the ratio of TM/TF in various thrombotic diseases including sepsis. Furthermore, we demonstrate loss of epsin protects mice against LPS-induced sepsis, suggesting a crucial role for epsins in promoting the development of LPS-induced sepsis.

Abstract 33: Role of Epsins in Regulating LPS-Induced Sepsis

Background: Sepsis is caused by a deleterious host response to infection, which is primarily responsible for further injury of host tissue and cause of organ dysfunction. However, the underlying regulatory mechanisms are still not fully understood. Our goal is to define the novel role of epsins in regulating sepsis.

Methods and Results: We engineered global (iDKO) and endothelial cell-specific (EC-iDKO) epsin deficient mice. When treated with lethal dose of LPS, epsin deficient mice were completely protected from LPS-induced septic death. These mice also exhibited decreased expression of tissue damage biomarkers and recruitment of neutrophils and macrophages to lungs compared to wild type (WT) suggesting that epsin deficiency mitigates sepsis induced tissue injury. Epsin deficiency further reduced expression of proinflammatory cytokines and adhesion molecules in the lungs suggesting that loss of epsin attenuates LPS-induced inflammatory responses. TAT complex production was also decreased in iDKO mice compared to WT indicating diminished coagulation and thrombin production. Knocking down of epsins in HUVECs resulted in reduced cell surface Tissue Factor (TF) expression. Loss of epsin in mice protected against loss of Thrombomodulin (TM), which is downregulated by sepsis. Mechanistically, loss of epsin inhibited LPS-induced TM internalization, while LPS treatment induced the ubiquitination of TM. Furthermore, co-IP of full length epsin 1 or epsin 1 without the UIM domain and TM demonstrated that UIM is required for the interaction between epsin 1 and TM. Collectively, we show that epsin-deficiency upregulates TM surface protein expression by preventing its internalization and subsequent degradation and inhibits heightened TF expression and activation under chronic inflammatory conditions such as that induced by LPS exposure.

Conclusions: Our findings demonstrate that epsins play a key role in regulating coagulation and provide fundamental information on the modulation of the ratio of TM/TF in various thrombotic diseases including sepsis. Furthermore, we demonstrate loss of epsin protects mice against LPS-induced sepsis, suggesting a crucial role for epsins in promoting the development of LPS-induced sepsis.

Epsin is required for Dishevelled stability and Wnt signalling activation in colon cancer development

Uncontrolled canonical Wnt signalling supports colon epithelial tumour expansion and malignant transformation. Understanding the regulatory mechanisms involved is crucial for elucidating the pathogenesis of and will provide new therapeutic targets for colon cancer. Epsins are ubiquitin-binding adaptor proteins upregulated in several human cancers; however, the involvement of epsins in colon cancer is unknown. Here we show that loss of intestinal epithelial epsins protects against colon cancer by significantly reducing the stability of the crucial Wnt signalling effector, dishevelled (Dvl2), and impairing Wnt signalling. Consistently, epsins and Dvl2 are correspondingly upregulated in colon cancer. Mechanistically, epsin binds Dvl2 via its epsin N-terminal homology domain and ubiquitin-interacting motifs and prohibits Dvl2 polyubiquitination and degradation. Our findings reveal an unconventional role for epsins in stabilizing Dvl2 and potentiating Wnt signalling in colon cancer cells to ensure robust colon cancer progression. The pro-carcinogenic role of Epsins suggests that they are potential therapeutic targets to combat colon cancer.

Temporal and spatial regulation of epsin abundance and VEGFR3 signaling are required for lymphatic valve formation and function

Lymphatic valves prevent the backflow of the lymph fluid and ensure proper lymphatic drainage throughout the body. Local accumulation of lymphatic fluid in tissues, a condition called lymphedema, is common in individuals with malformed lymphatic valves. The vascular endothelial growth factor receptor 3 (VEGFR3) is required for the development of lymphatic vascular system. The abundance of VEGFR3 in collecting lymphatic trunks is high before valve formation and, except at valve regions, decreases after valve formation. We found that in mesenteric lymphatics, the abundance of epsin 1 and 2, which are ubiquitin-binding adaptor proteins involved in endocytosis, was low at early stages of development. After lymphatic valve formation, the initiation of steady shear flow was associated with an increase in the abundance of epsin 1 and 2 in collecting lymphatic trunks, but not in valve regions. Epsin 1 and 2 bound to VEGFR3 and mediated the internalization and degradation of VEGFR3, resulting in termination of VEGFR3 signaling. Mice with lymphatic endothelial cell-specific deficiency of epsin 1 and 2 had dilated lymphatic capillaries, abnormally high VEGFR3 abundance in collecting lymphatics, immature lymphatic valves, and defective lymph drainage. Deletion of a single Vegfr3 allele or pharmacological suppression of VEGFR3 signaling restored normal lymphatic valve development and lymph drainage in epsin-deficient mice. Our findings establish a critical role for epsins in the temporal and spatial regulation of VEGFR3 abundance and signaling in collecting lymphatic trunks during lymphatic valve formation.

Genetic reduction of vascular endothelial growth factor receptor 2 rescues aberrant angiogenesis caused by epsin deficiency

OBJECTIVE

We previously showed that endothelial epsin deficiency caused elevated vascular endothelial growth factor receptor 2 (VEGFR2) and enhanced VEGF signaling, resulting in aberrant tumor angiogenesis and reduced tumor growth in adult mice. However, direct evidence demonstrating that endothelial epsins regulate angiogenesis specifically through VEGFR2 downregulation is still lacking. In addition, whether the lack of epsins causes abnormal angiogenesis during embryonic development remains unclear.

APPROACH AND RESULTS

A novel strain of endothelial epsin-deleted mice that are heterozygous for VEGFR2 (Epn1(fl/fl); Epn2(-/-); Flk(fl/+); iCDH5 Cre mice) was created. Analysis of embryos at different developmental stages showed that deletion of epsins caused defective embryonic angiogenesis and retarded embryo development. In vitro angiogenesis assays using isolated primary endothelial cells (ECs) from Epn1(fl/fl); Epn2(-/-); iCDH5 Cre (EC-iDKO) and Epn1(fl/fl); Epn2(-/-); Flk(fl/+); iCDH5 Cre (EC-iDKO-Flk(fl/+)) mice demonstrated that VEGFR2 reduction in epsin-depleted cells was sufficient to restore normal VEGF signaling, EC proliferation, EC migration, and EC network formation. These findings were complemented by in vivo wound healing, inflammatory angiogenesis, and tumor angiogenesis assays in which reduction of VEGFR2 was sufficient to rescue abnormal angiogenesis in endothelial epsin-deleted mice.

CONCLUSIONS

Our results provide the first genetic demonstration that epsins function specifically to downregulate VEGFR2 by mediating activated VEGFR2 internalization and degradation and that genetic reduction of VEGFR2 level protects against excessive angiogenesis caused by epsin loss. Our findings indicate that epsins may be a potential therapeutic target in conditions in which tightly regulated angiogenesis is crucial, such as in diabetic wound healing and tumors.