Spatial transcriptomics reveals discrete tumour microenvironments and autocrine loops within ovarian cancer subclones

High-grade serous ovarian carcinoma (HGSOC) is genetically unstable and characterised by the presence of subclones with distinct genotypes. Intratumoural heterogeneity is linked to recurrence, chemotherapy resistance, and poor prognosis. Here, we use spatial transcriptomics to identify HGSOC subclones and study their association with infiltrating cell populations. Visium spatial transcriptomics reveals multiple tumour subclones with different copy number alterations present within individual tumour sections. These subclones differentially express various ligands and receptors and are predicted to differentially associate with different stromal and immune cell populations. In one sample, CosMx single molecule imaging reveals subclones differentially associating with immune cell populations, fibroblasts, and endothelial cells. Cell-to-cell communication analysis identifies subclone-specific signalling to stromal and immune cells and multiple subclone-specific autocrine loops. Our study highlights the high degree of subclonal heterogeneity in HGSOC and suggests that subclone-specific ligand and receptor expression patterns likely modulate how HGSOC cells interact with their local microenvironment.

76 HOW BLOGS SUPPORT THE TRANSFER OF KNOWLEDGE INTO PRACTICE IN THE FIELD OF DEMENTIA PALLIATIVE CARE: FACILITATORS AND BARRIERS

Background

Blogging can help to maximise the impact of one’s work in academia and beyond by making research findings accessible for multiple knowledge users. As part of the knowledge exchange and dissemination activities of the Model for Dementia Palliative Care Project, this study explored stakeholders’ views of blogs as a means to translate research findings in the field of Dementia Palliative care.

Methods

A web-based survey was developed, piloted, and revised. It was distributed electronically via key dementia and palliative care organisations. Complete responses (N=128) were received from healthcare researchers (n=53), healthcare providers (n=46) and others with an interest in healthcare research (n=29). Data were analysed using descriptive statistics and content analysis

Results

The preferred methods of reviewing research findings were scientific papers, websites and news articles. Respondents read healthcare blogs “sometimes” (39.1%), with <19% reading them “often” or “very often”. Receiving an email notification might increase the likelihood of reading a new blog post for 83% of respondents. Barriers to engaging with blogs included lack of time, preference for other media, lack of awareness regarding available blogs, and concerns about the credibility and source of information. An appropriate length and the author of the blog were key features that encouraged engagement with a blog. Most respondents (37.7 % ‘Yes’ and 23.0% ‘Maybe’) would read Dementia Palliative care blogs by the research team.

Conclusion

Despite respondents choosing a scientific paper as their preferred method to consume research findings, many indicated an openness to reading blogs on their area of interest. Creating concise, relevant, and credible blogs, and suitably promoting them, could increase the impact and reach of healthcare research, such as in the emerging field of dementia palliative care, and thus promote translation of research findings into practice.

75 EVALUATING DEMENTIA PALLIATIVE CARE SERVICES ACROSS IRELAND AND THE UK USING THE RE-AIM FRAMEWORK

Background

Dementia is a life-limiting illness, requiring a Palliative Care (PC) approach from diagnosis. In Ireland, People with Dementia (PwD) and their families rarely receive PC in a timely manner. This study aimed to evaluate five exemplar community-based dementia PC services across Ireland and the UK (as identified by key stakeholders), to inform a new service delivery model.

Methods

Data from semi-structured interviews and focus groups with 29 service providers, and service activity data (n=5), was evaluated using the RE-AIM framework.

Results

‘Reach’ - Caseloads varied significantly between 3-154 active cases. Most services accepted self-referrals; all wanted earlier referrals. Factors influencing reach included co-location, dyadic participation, service flexibility, and others’ awareness of PC appropriateness and the service’s existence.

‘Effectiveness’ - All service users received holistic assessments, person-centred care, advanced care planning, continuity of care, improved service access and ‘care-for-the-carer’. Some services offered complimentary therapies, 24/7 phone support, and bereavement support; these were perceived to improve quality-of-life, comfort, and independence.

‘Adoption’ - Staff were highly invested; some provided their personal numbers to families. Outside staff were more willing to engage (refer/support) if shared governance, training was provided, or already familiar with dementia or the tools. Incentive programmes increased adoption rates.

‘Implementation ’ - All services evolved on an ad-hoc basis, with funding provided by local organisations, and a single ‘driving force’, typically a consultant/nurse. Services heavily relied on volunteers. Perceived “essential” elements included a dyadic approach, MDT involvement, open communication, forming relationships, reflective practices, dedicated staff with problem solving skills, and staff support/training.

‘Maintenance’ - All services continued after initial project funding; three increased their activities/reach over time.

Conclusion

Important features and facilitators of community-based dementia palliative care services have been identified. These results are informing the development of the novel Dementia Palliative Care model for use in Ireland (https://pallcare4dementia.com/).

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Excess mortality in England during the COVID-19 pandemic

Introduction

Excess mortality monitoring is not dependent on completeness or consistency of coding of causes of death and captures deaths caused directly and indirectly by COVID-19. It takes account of existing inequalities in the baseline rates and shows the additional impact of COVID-19. We report weekly on excess mortality by age, gender, geographical area, deprivation, and ethnicity.

Methods

A quasi-Poisson model was fitted to deaths data for 2015-2019 to estimate expected mortality in population sub-groups each week during the COVID-19 pandemic. This was compared with observed mortality reported each week. Information on deaths registered was obtained from death certificates. Ethnicity was obtained from hospital records linked to deaths data.

Results

Early in the pandemic, excess deaths exceeded official reported COVID-19 deaths every week. Throughout the pandemic there were stark inequalities in excess death rates. Based on data from 21 March 2020 to 9 April 2021, people living in the most deprived areas in England experienced more excess (1.21 times; 95% CI 1.21-1.22) compared with people living in the least deprived areas (1.17; 1.16-1.18). Black (1.56; 1.53-1.58) and Asian groups (1.55; 1.53-1.56) experienced more excess than the White group (1.16; 1.16-1.17). There was wide variation between English regions.

Conclusions

Reporting overall excess mortality early in the pandemic is important to inform policy makers and public about the true scale of the death toll when coding is inconsistent and developing. This approach has highlighted the large increases in already established inequalities in mortality. It provides rapid surveillance of developing disparities for national and local decision makers. It has been used to inform policy around reducing disparities and to revise messaging to encourage hospital attendance for non- COVID-19 health problems.

Key messages

Excess deaths from all causes is a robust measure of overall impact, unaffected by coding consistency. COVID-19 has dramatically worsened established inequalities between ethnic groups and deprivation groups.

Lichenoid dysplasia is not a distinct pathological entity

OBJECTIVES

Oral Lichenoid Dysplasia (OLD) is a controversial histological term applied to lesions that display features of oral lichen planus (OLP) and oral epithelial dysplasia (OED). In this study we investigated the molecular profiles of OLD, OLP and OED to determine whether OLD exists as a distinct pathological entity.

MATERIALS AND METHODS

Samples from patients presenting with lesions diagnosed histologically as OLP, OLD or OED underwent RNA sequencing followed by differential gene expression, functional enrichment and network analysis, sparse partial least squares discriminant analysis, and immune cell phenotypic estimation.

RESULTS

Unsupervised clustering demonstrated a group of genes with high expression in OLP and OLD, and low expression in OED, predominantly involved in inflammatory processes. Many genes were significantly differentially expressed between either OLD or OLP and OED, but few between OLD and OLP. Functional enrichment showed significant pathways and ontologies related to inflammatory signalling and immune response between OLD or OLP and OED. Broad commonality was found between OLP and OLD in upregulation of specific immune system pathways. Classifying models discriminated histologically diagnosed OLD from OED based upon molecular data alone. Bioinformatic profiling showed that immune cell populations in OLP and OLD were consistent, and distinct from OED.

CONCLUSION

Molecular data shows that OLD is not a distinct pathological entity. Its transcriptomic and immunophenotypic profile is similar to OLP and distinct from OED. We recommend that oral lichenoid dysplasia not be used as a distinct pathological entity. Our data further supports exclusion of dysplasia in diagnosis of OLP.

Can you trust what you hear? Concurrent misinformation affects recall memory and judgments of guilt

In most misinformation studies, participants are exposed to a to-be-remembered event and then subsequently given misinformation in textual form. This misinformation impacts people's ability to accurately report the initial event. In this article, we present 2 experiments that explored a different approach to presenting misinformation. In the context of a murder suspect, the to-be-remembered event was audio of a police interview, whereas the misinformation was copresented as subtitles with some words being different to, and more incriminating than, those that were actually said. We refer to this as concurrent misinformation. In Experiment 1, concurrent misinformation was inappropriately reported in a cued-recall test, and inflated participants' ratings of how incriminating the audio was. Experiment 2 attempted to employ warnings to mitigate the influence of concurrent misinformation. Warnings after the to-be-remembered event had no effect, whereas warnings before the event reduced the effect of concurrent misinformation for a subset of participants. Participants that noticed the discrepancy between the audio and the subtitles were also less likely to judge the audio as incriminating. These results were considered in relation to existing theories underlying the misinformation effect, as well as the implication for the use of audio and text in applied contexts. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Eosinophilic Myocarditis as a Cause of Death: A Case Diagnosed at Autopsy

Introduction/Objective

Eosinophilic (Loffler) myocarditis is a rare disease defined by the influx of eosinophils into the endocardium and myocardium. Etiologies are numerous and include drug or hypersensitivity reactions, hypereosinophilic syndrome, hematologic malignancies, and parasitic infections. It is a diagnostically challenging entity. Presenting symptoms recorded in the literature are indefinite and nonspecific; heart failure, demonstrable arrhythmia, and elevated cardiac biomarkers. This is especially the case among younger, otherwise healthy patients without classical risk factors for atherosclerotic coronary artery disease.

Methods

Herein we present several cases of sudden cardiac death in young adults, including a case of unknown eosinophilic myocarditis, which highlights the potential trials in the diagnosis of this disease.

Results

Autopsies were performed on several adults (age range, 30-40 years) thought to have died of cardiac causes. This included a 30-year-old African American female with no significant known medical history who presented with a chief complaint of palpitations. The initial clinical impression at an outside institution was of cardiac amyloidosis. But the Technetium99 scan was inconclusive. Despite clinical management, she developed ventricular arrhythmias and could not be resuscitated. There was a vague history of taking nutritional supplements from a local grocery store. Gross findings at autopsy included circumferential subepicardial erythema, thymic enlargement (60g), and congested lungs. The heart was thoroughly sampled. Microscopic examination revealed diffuse infiltration of eosinophils, mast cells, lymphocytes and macrophages with mild myocyte necrosis and interstitial edema in all sections. There were no giant cells, no interstitial deposition of amorphous acellular material and no focus of infarcted myocardium. Thymic sections were histologically normal. Acetylcholine receptor antibody panel was negative.

Conclusion

We conclude that eosinophilic myocarditis though rare (0.5% unsuspected and 0.1% suspected cases), is a distinctive cause of death with a specific microscopic presentation. Our case also included thymic enlargement at autopsy – a finding not previously noted.

Inhibition of IL-34 Unveils Tissue-Selectivity and Is Sufficient to Reduce Microglial Proliferation in a Model of Chronic Neurodegeneration

The proliferation and activation of microglia, the resident macrophages in the brain, is a hallmark of many neurodegenerative diseases such as Alzheimer's disease (AD) and prion disease. Colony stimulating factor 1 receptor (CSF1R) is critically involved in regulating microglial proliferation, and CSF1R blocking strategies have been recently used to modulate microglia in neurodegenerative diseases. However, CSF1R is broadly expressed by many cell types and the impact of its inhibition on the innate immune system is still unclear. CSF1R can be activated by two independent ligands, CSF-1 and interleukin 34 (IL-34). Recently, it has been reported that microglia development and maintenance depend on IL-34 signaling. In this study, we evaluate the inhibition of IL-34 as a novel strategy to reduce microglial proliferation in the ME7 model of prion disease. Selective inhibition of IL-34 showed no effects on peripheral macrophage populations in healthy mice, avoiding the side effects observed after CSF1R inhibition on the systemic compartment. However, we observed a reduction in microglial proliferation after IL-34 inhibition in prion-diseased mice, indicating that microglia could be more specifically targeted by reducing IL-34. Overall, our results highlight the challenges of targeting the CSF1R/IL34 axis in the systemic and central compartments, important for framing any therapeutic effort to tackle microglia/macrophage numbers during brain disease.

Fabrication of Bioengineered Skin by Injection Molding: A Feasibility Study on Automation

The use of bioengineered skin has facilitated fundamental and applied research because it enables the investigation of complex interactions between various cell types as well as the extracellular matrix. The predominantly manual fabrication of these living tissues means, however, that their quality, standardization, and production volume are extremely dependent on the technician's experience. Simple laboratory automation could facilitate the use of living tissues by a greater number of research groups. We developed and present here an injection molding technique for the fabrication of bilayered skin equivalents. The tissue was formed automatically by two separate injections into a customized mold to produce the dermal and epidermal skin layers. We demonstrated the biocompatibility of this fabrication process and confirmed the resulting bilayered morphology of the bioengineered skin using histology and immunohistochemistry. Our findings highlight the possibility of fabricating multilayered living tissue by injection molding, suggesting that further investigation into this automation method could result in the rapid and low-cost fabrication of standardized bioengineered skin.

A simplified fabrication technique for cellularized high-collagen dermal equivalents

Human autologous bioengineered skin has been successfully developed and used to treat skin injuries in a growing number of cases. In current clinical studies, the biomaterial used is fabricated via plastic compression of collagen hydrogel to increase the density and stability of the tissue. To further facilitate clinical adoption of bioengineered skin, the fabrication technique needs to be improved in terms of standardization and automation. Here, we present a one-step mixing technique using highly concentrated collagen and human fibroblasts to simplify fabrication of stable dermal equivalents. As controls, we prepared cellularized dermal equivalents with three varying collagen compositions. We found that the dermal equivalents produced using the simplified mixing technique were stable and pliable, showed viable fibroblast distribution throughout the tissue, and were comparable to highly concentrated manually produced collagen gels. Because no subsequent plastic compression of collagen is required in the simplified mixing technique, the fabrication steps and production time for dermal equivalents are consistently reduced. The present study provides a basis for further investigations to optimize the technique, which has significant promise in enabling efficient clinical production of bioengineered skin in the future.

Abstract P3-08-03: Dissecting the heterogeneity of metaplastic breast cancer: A morphological, immunohistochemical and genomic analysis of a large cohort

Although rare, Metaplastic Breast Carcinomas (MBC) account for significant global breast cancer mortality. This subgroup is extremely heterogeneous and by definition exhibits metaplastic change to squamous and/or mesenchymal elements, including but not limited to spindle, squamous, chondroid, osseous and rhabdomyoid elements. The WHO working group recognizes that the current classification is inadequate and in the interim, has suggested a purely descriptive classification. The mixed epithelial-mesenchymal morphology has led to speculation that MBC represent 'stem cell tumours'; in support of this, MBC have been shown to have a CD44+/CD24-/low phenotype. Clinically, patients present with tumours that are larger (higher stage), have increased likelihood of distant metastases at presentation and overall, have a reduced 5-year survival rate compared to Invasive Carcinoma-NST. Hence, this is a unique subtype with poor outcome but without a robust classification or understanding of the biology to aid clinical management. We present a detailed morphological, immunohistochemical and genomic analysis of a large series of MBC (n=347), as amassed through the Asia-Pacific MBC consortium. We consider our morphological dissection using the WHO subtyping guidelines and show that an increasing number of phenotypes in a mixed MBC (classified as WHO_1) significantly associates with a poor prognosis. Immunohistochemical analysis showed that a pure spindle (WHO_5) is significantly less likely to express vimentin, CK5/6, CK14, and CK19 than a mixed WHO_1 with spindle features. Similarly, a WHO_1 with chondroid features is less likely to express EGFR than WHO_1 with chondroid features and rhabdoid or osseous differentiation. Across the cohort, positivity for the AE1/3 antibody and a lack of EGFR expression both significantly associate with a better outcome. We report no significant association between patient age at diagnosis and breast cancer specific survival, nor between age and specific WHO MBC subtypes. We report a significant association between WHO_1 types and increasing tumour grade, and also between tumour size and grade, with tumour size being a highly significant prognostic indicator in this cohort. Our exome sequencing confirms a significant enrichment for TP53 and PTEN mutations in MBC, and intriguingly for concurrent mutations of TP53, PTEN and PIK3CA. A novel enrichment for NF1 mutations is also presented. In summary, we provide a thorough assessment of a large cohort of MBC, including morphology, survival, IHC and exome sequencing, and present our analysis contextualized by the WHO guidelines, extending the existing knowledge base of this rare tumour type.

Citation Format: McCart Reed AE, Kalaw E, Nones K, Bettington M, Lim M, Bennett J, Johnstone K, Kutasovic JR, Kazakoff S, Xu QC, Saunus JM, Reid LE, Black D, Niland C, Ferguson K, Gresshoff I, Raghavendra A, Liu JC, Kalinowski L, Reid AS, Davidson M, Pearson JV, Yamaguchi R, Harris G, Tse G, Papadimos D, Pathmanathan R, Pathmanathan N, Tan PH, Fox S, O'Toole S, Waddell N, Simpson PT, Lakhani SR. Dissecting the heterogeneity of metaplastic breast cancer: A morphological, immunohistochemical and genomic analysis of a large cohort [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-03.

Psychometric evaluation of a measure of factors influencing hand hygiene behaviour to inform intervention

BACKGROUND

Although the hand hygiene (HH) procedure is simple, the related behaviour is complex and is not readily understood, explained or changed. There is a need for practical tools to provide data that can guide healthcare managers and practitioners not only on the 'what' (the standards that must be met), but also the 'how' (guidance on how to achieve the standards).

AIM

To develop a valid questionnaire to evaluate attitudes to the factors that influence engagement in HH behaviour that can be readily completed, administered and analysed by healthcare professionals to identify appropriate intervention strategies. Construct validity was assessed using confirmatory factor analysis, predictive validity was assessed through comparison with self-reported HH behaviour, and convergent validity was assessed through direct unit-level observation of HH behaviour.

METHODS

The Capability, Opportunity, Motivation-Behaviour (COM-B) model was used to design a 25-item questionnaire that was distributed to intensive care unit (ICU) personnel in Ireland. Direct observation of HH behaviour was carried out at two ICUs.

FINDINGS

In total, 292 responses to the survey (response rate 41.0%) were included in the analysis. Confirmatory factor analysis resulted in a 17-item questionnaire. Multiple regression revealed that a model including capability, opportunity and motivation was a significant predictor of self-reported behavioural intention [F(3,209)=22.58, P<0.001]. However, the opportunity factor was not found to make a significant contribution to the regression model.

CONCLUSION

The COM-B HH questionnaire is reliable and valid, and provides data to support the development and evaluation of HH interventions that meet the needs of specific healthcare units.

CD8+ cytotoxic T cell responses to dominant tumor-associated antigens are profoundly weakened by aging yet subdominant responses retain functionality and expand in response to chemotherapy

Increasing life expectancy is associated with increased cancer incidence, yet the effect of cancer and anti-cancer treatment on elderly patients and their immune systems is not well understood. Declining T cell function with aging in response to infection and vaccination is well documented, however little is known about aged T cell responses to tumor antigens during cancer progression or how these responses are modulated by standard chemotherapy. We examined T cell responses to cancer in aged mice using AE17sOVA mesothelioma in which ovalbumin (OVA) becomes a 'spy' tumor antigen containing one dominant (SIINFEKL) and two subdominant (KVVRFDKL and NAIVFKGL) epitopes. Faster progressing tumors in elderly (22-24 months, cf. 60-70 human years) relative to young (2-3 months, human 15-18 years) mice were associated with increased pro-inflammatory cytokines and worsened cancer cachexia. Pentamer staining and an in-vivo cytotoxic T lymphocyte (CTL) assay showed that whilst elderly mice generated a greater number of CD8⁺ T cells recognizing all epitopes, they exhibited a profound loss of function in their ability to lyse targets expressing the dominant, but not subdominant, epitopes compared to young mice. Chemotherapy was less effective and more toxic in elderly mice however, similar to young mice, chemotherapy expanded CTLs recognizing at least one subdominant epitope in tumors and draining lymph nodes, yet treatment efficacy still required CD8⁺ T cells. Given the significant dysfunction associated with elderly CTLs recognizing dominant epitopes, our data suggest that responses to subdominant tumor epitopes may become important when elderly hosts with cancer are treated with chemotherapy.

Achilles Tenorrhaphy in Five Dogs: A Modified Surgical Technique and Evaluation of a Cranial Half Cast

Achilles mechanism rupture in four of five dogs was treated with tenorrhaphy using a modified surgical technique designed to optimise accurate apposition of tendon to bone. Two bone tunnels were drilled in the calcaneal tuber from a plantomedial - dorsolateral, and plantolateral – dorsomedial direction respectively. The distal ends of the tendons were sutured to the calcaneal tuber using a Krachow suture pattern. The remaining dog had a mid-tendon Achilles mechanism rupture. A resinous half cast was placed on the cranial aspect of the tarsocrural joint of all five dogs, for a minimum of six weeks, in order to provide limited post operative support. Du e to insufficient cast material two of the support splints failed and one of these cases also required a second surgical procedure. A varying amount of soft tissue irritation was noted in each case. All of the five Achilles mechanisms healed, and all of the dogs returned to normal function.

Five dogs with surgical reconstruction of the Achilles mechanism were stabilised postoperatively with a resinous half cast placed on the cranial aspect of the tarsocrural joint for a minimum of six weeks. Two of these casts failed at the tarsocrural joint when six folds of casting material were used; all subsequent cases had eight folds applied. Variable soft tissue irration was observed under the cast in each case. A modified surgical technique using a Krachow suture pattern allowed good tendon-bone apposition. All five Achilles mechanisms healed, and all dogs returned to normal function. Bilateral lesions were identified in 3 of the 4 dogs examined.

Are any populations 'safe'? Unexpected reproductive decline in a population of Tasmanian devils free of devil facial tumour disease

Context Conservation management relies on baseline demographic data of natural populations. For Tasmanian devils (Sarcophilus harrisii), threatened in the wild by two fatal and transmissible cancers (devil facial tumour disease DFTD: DFT1 and DFT2), understanding the characteristics of healthy populations is crucial for developing adaptive management strategies to bolster populations in the wild. Aims Our analysis aims to evaluate contemporary reproductive rates for wild, DFTD-free Tasmanian devil populations, and to provide a baseline with which to compare the outcome of current translocation activities. Methods We analysed 8 years of field-trapping data, including demographics and reproductive rates, across 2004–16, from the largest known DFTD-free remnant population at Woolnorth, Tasmania. Key results Surprisingly, we found a dramatic and statistically significant decline in female breeding rate when comparing data collected from 2004–2009 with data from 2014–2016. Unfortunately we do not have any data from the intermediate years. This decline in breeding rate was accompanied by a subtle but statistically significant decline in litter sizes. These changes were not associated with a change in body condition over the same period. Furthermore, we could not attribute the decline in breeding to a change in population size or sex ratio. Preliminary analysis suggested a possible association between annual breeding rate and coarse measures of environmental variation (Southern Oscillation Index), but any mechanistic associations are yet to be determined. Conclusions The decline in breeding rates was unexpected, so further monitoring and investigation into potential environmental and/or biological reasons for the decline in breeding rate are recommended before the arrival of DFTD at Woolnorth. Implications Our results provide valuable data to support the conservation management of Tasmanian devils in their native range. They also highlight the importance of continued monitoring of ‘safe’ populations, in the face of significant threats elsewhere.

A Remote Assay for Measuring Canine Platelet Activation and the Inhibitory Effects of Antiplatelet Agents

BACKGROUND

Antiplatelet medications are increasingly used in dogs. Remote analysis of platelet activity is challenging, limiting assessment of antiplatelet drug efficacy.

HYPOTHESIS/OBJECTIVES

To evaluate a method used in humans for stimulation and remote analysis of canine platelet activity.

ANIMALS

Forty-five dogs of various ages without a coagulopathy or thrombocytopenia. Six were receiving antiplatelet medication.

METHODS

Prospective observational study. Platelets were stimulated with combinations of arachidonic acid (AA) and epinephrine (Epi) or adenosine diphosphate (ADP) and the thromboxane A₂ -mimetic U46619 (U4). PAMFix was added to the blood samples to facilitate delayed analysis of platelet activity. Activity was assessed by flow cytometric measurement of surface P-selectin (CD62P) expression.

RESULTS

Canine platelets could be stimulated with both AA/Epi and ADP/U4. The levels of P-selectin were significantly greater than paired, unstimulated samples (P < 0.001). Inhibition of P-selectin expression occurred after this stimulation by adding antiplatelet drugs in vitro. The efficacy of antiplatelet drugs in samples from treated dogs was also measurable ex vivo using this method. Delayed analysis of platelet activity at time points up to 22 days demonstrated excellent correlation between respective mf values at each time point (r²  = 0.92, P < 0.0001).

CONCLUSIONS AND CLINICAL IMPORTANCE

This study evaluated a new method to remotely assess canine platelet activity. It shows that PAMFix can be used for this purpose. This provides opportunities to interrogate the inhibitory action of antiplatelet drugs in clinical settings.

Abstract 932: Wnt antagonist, secreted frizzled-related protein 4 (SFRP4) and peptides from its associated domains, increases chemotherapeutic response of cancer stem cells of malignant mesothelioma cell lines

Malignant mesothelioma (MM) is a highly aggressive cancer associated with past asbestos exposure that is characterized by rapid progression, late metastases and poor prognosis. There is a need for much improved and novel therapies for this cancer through improved biological understanding of the disease.Previous studies have shown that SFRPs in general and SFRP4 in particular are down regulated in mesothelioma tissue and cell lines 1-4. Based on our own study and previously demonstrated a role for sFRP4 in making chemoresistant tumours amenable to chemotherapeutics 5-16. We have now progressed our work into the effects of peptides derived from the cysteine-rich domain and the netrin-like domain of sFRP4 on tumour initiating cells derived from MM cell lines.We examined the effect of secreted frizzled-related protein 4 (sFRP4), a Wnt signaling antagonist and its associated peptides, in chemosensitizing the MM cell line ONE 58 and JU77 and MM cancer stem cells (CSCs) enriched from these two cell lines to chemotherapeutics.We found tumorspheres exposed to sFRP4 and peptides alone and in combination with cisplatin induced cell death and decreased CD133 and ALDH1 expression.We thus identified for the first time that sFRP4 and associated peptides could help to sensitise to chemotherapeutics and destroy cancer stem cells of MM cell line, which would lead to effective treatment regimen to combat malignant mesothelioma. Our initial in vitro data exemplify the ability of these peptides in diminishing the numbers of therapy-resistant Tumor initiating cells (TICs).

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Citation Format: Vanathi Perumal, Senthil Kumar, Frank Arfuso, Simon Fox, Arunasalam Dharmarajan. Wnt antagonist, secreted frizzled-related protein 4 (SFRP4) and peptides from its associated domains, increases chemotherapeutic response of cancer stem cells of malignant mesothelioma cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 932. doi:10.1158/1538-7445.AM2017-932

Cathelicidins in the Tasmanian devil (Sarcophilus harrisii)

Tasmanian devil joeys, like other marsupials, are born at a very early stage of development, prior to the development of their adaptive immune system, yet survive in a pathogen-laden pouch and burrow. Antimicrobial peptides, called cathelicidins, which provide innate immune protection during early life, are expressed in the pouch lining, skin and milk of devil dams. These peptides are active against pathogens identified in the pouch microbiome. Of the six characterised cathelicidins, Saha-CATH5 and 6 have broad-spectrum antibacterial activity and are capable of killing problematic human pathogens including methicillin-resistant S. aureus and vancomycin-resistant E. faecalis, while Saha-CATH3 is active against fungi. Saha-CATH5 and 6 were toxic to human A549 cells at 500 μg/mL, which is over seven times the concentration required to kill pathogens. The remaining devil cathelicidins were not active against tested bacterial or fungal strains, but are widely expressed throughout the body, such as in immune tissues, in digestive, respiratory and reproductive tracts, and in the milk and pouch, which indicates that they are likely also important components of the devil immune system. Our results suggest cathelicidins play a role in protecting naive young during pouch life by passive immune transfer in the milk and may modulate pouch microbe populations to reduce potential pathogens.

Restoration of tumor suppression in prostate cancer by targeting the E3 ligase E6AP

Restoration of tumor suppression is an attractive onco-therapeutic approach. It is particularly relevant when a tumor suppressor is excessively degraded by an overactive oncogenic E3 ligase. We previously discovered that the E6-associated protein (E6AP; as classified in the human papilloma virus context) is an E3 ligase that has an important role in the cellular stress response, and it directly targets the tumor-suppressor promyelocytic leukemia protein (PML) for proteasomal degradation. In this study, we have examined the role of the E6AP-PML axis in prostate cancer (PC). We show that knockdown (KD) of E6AP expression attenuates growth of PC cell lines in vitro. We validated this finding in vivo using cell line xenografts, patient-derived xenografts and mouse genetics. We found that KD of E6AP attenuates cancer cell growth by promoting cellular senescence in vivo, which correlates with restoration of tumor suppression by PML. In addition, we show that KD of E6AP sensitizes cells to radiation-induced death. Overall, our findings demonstrate a role for E6AP in the promotion of PC and support E6AP targeting as a novel approach for PC treatment, either alone or in combination with radiation.

Structure of a Potential Therapeutic Antibody Bound to Interleukin-16 (IL-16): MECHANISTIC INSIGHTS AND NEW THERAPEUTIC OPPORTUNITIES

Interleukin-16 (IL-16) is reported to be a chemoattractant cytokine and modulator of T-cell activation, and has been proposed as a ligand for the co-receptor CD4. The secreted active form of IL-16 has been detected at sites of TH1-mediated inflammation, such as those seen in autoimmune diseases, ischemic reperfusion injury (IRI), and tissue transplant rejection. Neutralization of IL-16 recruitment to its receptor, using an anti-IL16 antibody, has been shown to significantly attenuate inflammation and disease pathology in IRI, as well as in some autoimmune diseases. The 14.1 antibody is a monoclonal anti-IL-16 antibody, which when incubated with CD4(+) cells is reported to cause a reduction in the TH1-type inflammatory response. Secreted IL-16 contains a characteristic PDZ domain. PDZ domains are typically characterized by a defined globular structure, along with a peptide-binding site located in a groove between the αB and βB structural elements and a highly conserved carboxylate-binding loop. In contrast to other reported PDZ domains, the solution structure previously reported for IL-16 reveals a tryptophan residue obscuring the recognition groove. We have solved the structure of the 14.1Fab fragment in complex with IL-16, revealing that binding of the antibody requires a conformational change in the IL-16 PDZ domain. This involves the rotation of the αB-helix, accompanied movement of the peptide groove obscuring tryptophan residue, and consequent opening up of the binding site for interaction. Our study reveals a surprising mechanism of action for the antibody and identifies new opportunities for the development of IL-16-targeted therapeutics, including small molecules that mimic the interaction of the antibody.

Therapeutic approach to target mesothelioma cancer cells using the Wnt antagonist, secreted frizzled-related protein 4: Metabolic state of cancer cells

Malignant mesothelioma (MM) is an aggressive cancer, characterized by rapid progression, along with late metastasis and poor patient prognosis. It is resistant to many forms of standard anti-cancer treatment. In this study, we determined the effect of secreted frizzled-related protein 4 (sFRP4), a Wnt pathway inhibitor, on cancer cell proliferation and metabolism using the JU77 mesothelioma cell line. Treatment with sFRP4 (250 pg/ml) resulted in a significant reduction of cell proliferation. The addition of the Wnt activator Wnt3a (250 pg/ml) or sFRP4 had no significant effect on ATP production and glucose utilisation in JU77 cells at both the 24 and 48 h time points examined. We also examined their effect on Akt and Glycogen synthase kinase-3 beta (GSK3β) phosphorylation, which are both important components of Wnt signalling and glucose metabolism. We found that protein phosphorylation of Akt and GSK3β varied over the 24h and 48 h time points, with constitutive phosphorylation of Akt at serine 473 (pAkt) decreasing to its most significant level when treated with Wnt3a+sFRP4 at the 24h time point. A significant reduction in the level of Cytochrome c oxidase was observed at the 48 h time point, when sFRP4 and Wnt3a were added in combination. We conclude that sFRP4 may function, in part, to reduce/alter cancer cell metabolism, which may lead to sensitisation of cancer cells to chemotherapeutics, or even cell death.

Expression and therapeutic targeting of dopamine receptor-1 (D1R) in breast cancer

Patients with advanced breast cancer often fail to respond to treatment, creating a need to develop novel biomarkers and effective therapeutics. Dopamine (DA) is a catecholamine that binds to five G protein-coupled receptors. We discovered expression of DA type-1 receptors (D1Rs) in breast cancer, thereby identifying these receptors as novel therapeutic targets in this disease. Strong to moderate immunoreactive D1R expression was found in 30% of 751 primary breast carcinomas, and was associated with larger tumors, higher tumor grades, node metastasis and shorter patient survival. DA and D1R agonists, signaling through the cGMP/protein kinase G (PKG) pathway, suppressed cell viability, inhibited invasion and induced apoptosis in multiple breast cancer cell lines. Fenoldopam, a peripheral D1R agonist that does not penetrate the brain, dramatically suppressed tumor growth in two mouse models with D1R-expressing xenografts by increasing both necrosis and apoptosis. D1R-expressing primary tumors and metastases in mice were detected by fluorescence imaging. In conclusion, D1R overexpression is associated with advanced breast cancer and poor prognosis. Activation of the D1R/cGMP/PKG pathway induces apoptosis in vitro and causes tumor shrinkage in vivo. Fenoldopam, which is FDA (Food and Drug Administration) approved to treat renal hypertension, could be repurposed as a novel therapeutic agent for patients with D1R-expressing tumors.

Catechols and 3-hydroxypyridones as inhibitors of the DNA repair complex ERCC1-XPF

Catechol-based inhibitors of ERCC1-XPF endonuclease activity were identified from a high-throughput screen. Exploration of the structure-activity relationships within this series yielded compound 13, which displayed an ERCC1-XPF IC50 of 0.6 μM, high selectivity against FEN-1 and DNase I and activity in nucleotide excision repair, cisplatin enhancement and γH2AX assays in A375 melanoma cells. Screening of fragments as potential alternatives to the catechol group revealed that 3-hydroxypyridones are able to inhibit ERCC1-XPF with high ligand efficiency, and elaboration of the hit gave compounds 36 and 37 which showed promising ERCC1-XPF IC50 values of <10 μM.

N-Hydroxyimides and hydroxypyrimidinones as inhibitors of the DNA repair complex ERCC1-XPF

A high throughput screen allowed the identification of N-hydroxyimide inhibitors of ERCC1-XPF endonuclease activity with micromolar potency, but they showed undesirable selectivity profiles against FEN-1. A scaffold hop to a hydroxypyrimidinone template gave compounds with similar potency but allowed selectivity to be switched in favour of ERCC1-XPF over FEN-1. Further exploration of the structure-activity relationships around this chemotype gave sub-micromolar inhibitors with >10-fold selectivity for ERCC1-XPF over FEN-1.

A phase Ib/II translational study of sunitinib with neoadjuvant radiotherapy in soft-tissue sarcoma

Background:

Preoperative radiotherapy (RT) is commonly used to treat localised soft-tissue sarcomas (STS). Hypoxia is an important determinant of radioresistance. Whether antiangiogenic therapy can ‘normalise' tumour vasculature, thereby improving oxygenation, remains unknown.

Methods:

Two cohorts were prospectively enrolled. Cohort A evaluated the implications of hypoxia in STS, using the hypoxic tracer ¹⁸F-azomycin arabinoside (FAZA-PET). In cohort B, sunitinib was added to preoperative RT in a dose-finding phase 1b/2 design.

Results:

In cohort A, 13 out of 23 tumours were hypoxic (FAZA-PET), correlating with metabolic activity (r²=0.85; P<0.001). Two-year progression-free (PFS) and overall (OS) survival were 61% (95% CI: 0.44–0.84) and 87% (95% CI: 0.74–1.00), respectively. Hypoxia was associated with radioresistance (P=0.012), higher local recurrence (Hazard ratio (HR): 10.2; P=0.02), PFS (HR: 8.4; P=0.02), and OS (HR: 41.4; P<0.04). In Cohort B, seven patients received sunitinib at dose level (DL): 0 (50 mg per day for 2 weeks before RT; 25 mg per day during RT) and two patients received DL: −1 (37.5 mg per day for entire period). Dose-limiting toxicities were observed in 4 out of 7 patients at DL 0 and 2 out of 2 patients at DL −1, resulting in premature study closure. Although there was no difference in PFS or OS, patients receiving sunitinib had higher local failure (HR: 8.1; P=0.004).

Conclusion:

In STS, hypoxia is associated with adverse outcomes. The combination of sunitinib with preoperative RT resulted in unacceptable toxicities, and higher local relapse rates.

Dogs Entering the United States from Rabies-Endemic Countries, 2011-2012

International dog imports pose a risk because of the potential movement of disease agents, including the canine rabies virus variant which has been eliminated from the United States since 2007. US regulations require a rabies vaccination certificate for dogs arriving from rabies-endemic countries, but permit the importation of dogs that have not been adequately immunized against rabies, provided that the dogs are confined under conditions that restrict their contact with humans and other animals until they have been immunized. CDC Form 75.37, 'Notice to Owners and Importers of Dogs', explains the confinement requirements and serves as a binding confinement agreement with the importer. In this evaluation, we describe the characteristics of unimmunized dogs imported into the United States over a 1-year period based upon dog confinement agreements recorded at the Centers for Disease Control and Prevention (CDC) quarantine stations. Confinement agreements were issued for nearly 2800 unimmunized dogs that entered the United States during 1 June 2011-31 May 2012, the majority of which travelled to the United States by air and without any seasonal pattern in import volume. Over 60% of these animals were puppies <3 months of age and included a wide variety of breeds. The dogs arrived from 81 countries, with the majority arriving from North America or Europe. Dogs placed on confinement agreements had final destinations in 49 states. California, New York, Texas, Washington and Florida received the largest number of dogs on confinement agreements. These results (which do not reflect human travel or US dog ownership data) suggest that a large portion of unimmunized dogs arrive from rabies-endemic countries for commercial, shelter and rescue purposes. Further evaluation and key stakeholder involvement are needed to assess whether the current dog importation regulations are an adequate compromise between the benefits and risks of dog importation.

Downregulation of Mcl-1 has anti-inflammatory pro-resolution effects and enhances bacterial clearance from the lung

Phagocytes not only coordinate acute inflammation and host defense at mucosal sites, but also contribute to tissue damage. Respiratory infection causes a globally significant disease burden and frequently progresses to acute respiratory distress syndrome, a devastating inflammatory condition characterized by neutrophil recruitment and accumulation of protein-rich edema fluid causing impaired lung function. We hypothesized that targeting the intracellular protein myeloid cell leukemia 1 (Mcl-1) by a cyclin-dependent kinase inhibitor (AT7519) or a flavone (wogonin) would accelerate neutrophil apoptosis and resolution of established inflammation, but without detriment to bacterial clearance. Mcl-1 loss induced human neutrophil apoptosis, but did not induce macrophage apoptosis nor impair phagocytosis of apoptotic neutrophils. Neutrophil-dominant inflammation was modelled in mice by either endotoxin or bacteria (Escherichia coli). Downregulating inflammatory cell Mcl-1 had anti-inflammatory, pro-resolution effects, shortening the resolution interval (Ri) from 19 to 7 h and improved organ dysfunction with enhanced alveolar-capillary barrier integrity. Conversely, attenuating drug-induced Mcl-1 downregulation inhibited neutrophil apoptosis and delayed resolution of endotoxin-mediated lung inflammation. Importantly, manipulating lung inflammatory cell Mcl-1 also accelerated resolution of bacterial infection (Ri; 50 to 16 h) concurrent with enhanced bacterial clearance. Therefore, manipulating inflammatory cell Mcl-1 accelerates inflammation resolution without detriment to host defense against bacteria, and represents a target for treating infection-associated inflammation.

Population structure and residency of whale sharks Rhincodon typus at Utila, Bay Islands, Honduras

There were 479 reported whale shark Rhincodon typus encounters between 1999 and 2011 at the island of Utila, which forms part of the Meso-American Barrier Reef System (MBRS) in the western Caribbean Sea. The majority of R. typus were found to feed on small bait fish associated with various tuna species. Ninety-five individual R. typus, ranging from 2 to 11 m total length (LT ), were identified through their unique spot patterns. A significant male bias (65%) was present. There was no significant difference between the mean ± s.d. LT of female (6·66 ± 1·65 m) and male (6·25 ± 1·60 m) R. typus. Most R. typus were transient to Utila, with 78% sighted only within a single calendar year, although some individuals were sighted in up to 5 years. Mean residency time was modelled to be 11·76 days using maximum likelihood methods.

Roles of Education and IQ in Cognitive Reserve in Parkinson's Disease-Mild Cognitive Impairment

Background/Aims

The role of cognitive reserve in Parkinson's disease (PD)-mild cognitive impairment (MCI) is incompletely understood.

Methods

The relationships between PD-MCI, years of education, and estimated premorbid IQ were examined in 119 consecutive non-demented PD patients using logistic regression models.

Results

Higher education and IQ were associated with reduced odds of PD-MCI in univariate analysis. In multivariable analysis, a higher IQ was associated with a significantly decreased odds of PD-MCI, but education was not.

Conclusion

The association of higher IQ and decreased odds of PD-MCI supports a role for cognitive reserve in PD, but further studies are needed to clarify the interaction of IQ and education and the impact of other contributors such as employment and hobbies.