Assessing 'response' to the low-FODMAP diet in irritable bowel syndrome: Should we be reporting harder primary endpoints?

BACKGROUND & AIMS

The low-FODMAP diet (LFD) has become almost synonymous with IBS care, yet the challenges associated with this rigorous therapeutic approach are often underacknowledged. Despite positive outcomes in RCTs, comparator groups frequently exhibit substantial response rates, raising questions about the definition of 'response'. Whilst the assessment of response in drug trials has evolved to utilize the more stringent FDA/EMA primary clinical endpoints, trials of the LFD have not yet followed. The aim of this article is to opine whether the current approach to the measurement of clinical response to the LFD in clinical trials should be reconsidered.

METHODS

A comprehensive literature review of LFD clinical trials from the past decade was conducted, focusing on recorded response metrics for primary clinical endpoints.

RESULTS

While response definitions vary, the 50-point IBS-SSS delta emerged as the predominant metric. Notably, no trials to date have adopted the more stringent primary clinical endpoints used in drug trials. Other response measures included binary response metrics (such as 'adequate clinical response'), changes in visual analogue scales or stool form/output, reductions in abdominal pain, as well as changes the magnitude of the IBS-SSS delta. Whether these metrics correspond to a clinically meaningful improvement for the patient is less clear, and as such aligning patient-clinician expectations can be challenging.

CONCLUSIONS

A paradigm shift in the conceptualization of 'response' coupled with an emphasis on harder clinical endpoints in the context of clinical trials may serve to better justify the trade-off between symptom-improvement and the inherent challenges associated with this burdensome therapeutic approach.

Impact on patient outcomes of spondyloarthritis-inflammatory bowel disease multi-disciplinary meetings

OBJECTIVES

To assess the impact on patient outcomes of the spondyloarthritis (SpA) and inflammatory bowel disease (IBD) multidisciplinary team (MDT) meetings in a large university hospital.

METHODS

A single-centre retrospective observational case-note review was conducted assessing the outcome of all 226 cases discussed at the SpA-IBD MDT meetings in a large UK university hospital between 2017-2022.

RESULTS

A total of 226 patients were discussed. It was deemed that 97% of MDT meetings helped to improve communication between teams, and 100% were educational. A total of 57% of discussions led to an instant change of disease management, while 40% of discussions resulted in a treatment plan that avoided the use of dual advanced therapy. This improved patient safety by reducing immunosuppression. The MDT meetings were highly cost and time efficient; 125 referrals between specialists were avoided, and in 51 cases there was a significant chance of reducing future drug costs. A timely investigation or appointment was arranged following 50% of MDT discussions, helping to clarify the diagnosis and optimise patient care. 9% of meetings enabled drugs to be prescribed to patients that are not yet licenced for the other speciality, thereby improving treatment options available in the management of complex cases.

CONCLUSION

The MDT meetings have been beneficial for patients, the clinical team and the institution. This approach might be considered by other rheumatology and gastroenterology departments.

Immunogenicity of Co-Administered Omicron BA.4/BA.5 Bivalent COVID-19 and Quadrivalent Seasonal Influenza Vaccines in Israel during the 2022-2023 Winter Season

Vaccination against COVID-19 and influenza provides the best defense against morbidity and mortality. Administering both vaccines concurrently may increase vaccination rates and reduce the burden on the healthcare system. This study evaluated the immunogenicity of healthcare workers in Israel who were co-administered with the Omicron BA.4/BA.5 bivalent COVID-19 vaccine and the 2022-2023 quadrivalent influenza vaccine. SARS-CoV-2 neutralizing antibody titers were measured via microneutralization while influenza antibody titers were measured via hemagglutination inhibition. No immunogenic interference was observed by either vaccine when co-administered. Antibody titers against SARS-CoV-2 variants increased significantly in the cohort receiving the COVID-19 vaccine alone and in combination with the influenza vaccine. Antibody titers against the A/H1N1 influenza strain increased significantly in the cohort receiving the influenza vaccine alone and in combination with the COVID-19 vaccine. Antibody titers against B/Victoria increased significantly in the cohort that received both vaccines. This study has important public health implications for the 2023-2024 winter season, and supports co-administration of both vaccines as a viable immunization strategy.

The Novel DNA Binding Mechanism of Ridinilazole, a Precision Clostridiodes difficile Antibiotic

Clostridioides difficile infection (CDI) causes substantial morbidity and mortality worldwide with limited antibiotic treatment options. Ridinilazole is a precision bisbenzimidazole antibiotic being developed to treat CDI and reduce unacceptably high rates of infection recurrence in patients. Although in late clinical development, the precise mechanism of action by which ridinilazole elicits its bactericidal activity has remained elusive. Here, we present conclusive biochemical and structural data to demonstrate that ridinilazole has a primary DNA binding mechanism, with a co-complex structure confirming binding to the DNA minor groove. Additional RNA-seq data indicated early pleiotropic changes to transcription, with broad effects on multiple C. difficile compartments and significant effects on energy generation pathways particularly. DNA binding and genomic localization was confirmed through confocal microscopy utilizing the intrinsic fluorescence of ridinilazole upon DNA binding. As such, ridinilazole has the potential to be the first antibiotic approved with a DNA minor groove binding mechanism of action.

Abstract 3636: Liver endothelium secreted LRG1 promotes metastatic colorectal cancer growth through the HER3/RSK/EIF4B AXIS

Background: 25% of patients diagnosed with colorectal cancer (CRC) have liver metastasis at presentation, and ~80% of all metastatic CRC are developed in the liver. We previously reported that liver endothelial cells (ECs), a key component of the liver microenvironment, secrete LRG1 to promote CRC growth via activating human epidermal growth factor receptor (ERbB3, also known as HER3). However, we found that LRG1-induced HER3 activation is distinct from the canonical neuregulin 1 (NRG1)-induced HER3 pathway. The present study further validated LRG1 as a new HER3 ligand for promoting mCRC growth and elucidated the novel downstream signaling pathway induced by LRG1-HER3.

Methods: We first measured the binding affinity between HER3 and LRG1 by Biolayer interferometry (BLI). We then used in vitro and in vivo xenograft approaches to determine the effect of LRG1 monoclonal antibody (15C4) on HER3 activation and CRC growth. To further determine the role of LRG1 in promoting CRC growth in the liver, we used murine CRC cells in a syngeneic orthotropic liver injection model to establish CRC allografts in the liver of LRG1−/− mice with systemic LRG1 knockout and wild-type siblings (LRG1+/+). We also performed unbiased phospho-MS analysis and subsequent validations to determine the downstream signaling pathway activated by LRG1-HER3.

Results: We identified that LRG1 binds to HER3 with the affinity at ~100nM. The LRG1 antibody 15C4 completely attenuated LRG1-induced HER3 activation and in vitro and xenograft growth in vivo. Moreover, LRG1−/− mice with CRC allografts in the liver had 2 times longer overall survival than tumor-bearing LRG1+/+ mice. Lastly, unbiased -omics analysis identified eIF4-protein synthesis is significantly activated by LRG1. With target-specific inhibitors, we further determined that LRG1-HER3 activates the PI3K-PDK1-RSK1/3-eIF4 axis independent of AKT.

Conclusions: We identified LRG1 as a novel HER3 ligand and demonstrated that the liver microenvironment-derived LRG1 plays a key oncogenic role in mCRC, by activating a novel RSK-eIF4 survival pathway. Our findings highlighted the potential of blocking LRG1-HER3 and involved downstream pathways for treating patients with mCRC.

Citation Format: Moeez Ghani Rathore, Michelle Wright, Wei Huang, Derek Taylor, Yamu Li, Jordan Winter, Zhenghe Wang, John Greenwood, Stephen Moss, Rui Wang. Liver endothelium secreted LRG1 promotes metastatic colorectal cancer growth through the HER3/RSK/EIF4B AXIS. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3636.

Two microbiota subtypes identified in irritable bowel syndrome with distinct responses to the low FODMAP diet

OBJECTIVE

Reducing FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) can be clinically beneficial in IBS but the mechanism is incompletely understood. We aimed to detect microbial signatures that might predict response to the low FODMAP diet and assess whether microbiota compositional and functional shifts could provide insights into its mode of action.

DESIGN

We used metagenomics to determine high-resolution taxonomic and functional profiles of the stool microbiota from IBS cases and household controls (n=56 pairs) on their usual diet. Clinical response and microbiota changes were studied in 41 pairs after 4 weeks on a low FODMAP diet.

RESULTS

Unsupervised analysis of baseline IBS cases pre-diet identified two distinct microbiota profiles, which we refer to as IBSP (pathogenic-like) and IBSH (health-like) subtypes. IBSP microbiomes were enriched in Firmicutes and genes for amino acid and carbohydrate metabolism, but depleted in Bacteroidetes species. IBSH microbiomes were similar to controls. On the low FODMAP diet, IBSH and control microbiota were unaffected, but the IBSP signature shifted towards a health-associated microbiome with an increase in Bacteroidetes (p=0.009), a decrease in Firmicutes species (p=0.004) and normalisation of primary metabolic genes. The clinical response to the low FODMAP diet was greater in IBSP subjects compared with IBSH (p=0.02).

CONCLUSION

50% of IBS cases manifested a 'pathogenic' gut microbial signature. This shifted towards the healthy profile on the low FODMAP diet; and IBSP cases showed an enhanced clinical responsiveness to the dietary therapy. The effectiveness of FODMAP reduction in IBSP may result from the alterations in gut microbiota and metabolites produced. Microbiota signatures could be useful as biomarkers to guide IBS treatment; and investigating IBSP species and metabolic pathways might yield insights regarding IBS pathogenic mechanisms.

AB1523-HPR USABILITY AND ACCEPTABILITY OF A NEW AUTOINJECTOR DEVICE AND ITS ASSOCIATED APP IN AUSTRALIAN, FRENCH, GERMANY AND JAPANESE RHEUMATOLOGY PATIENTS

Background

Smartclic/ClicWise is a new reusable autoinjector with a dose-dispensing cartridge for subcutaneous self-administration of biotherapeutics in development for patients with rheumatoid arthritis (RA) and other diseases. The device can connect to an optional mobile phone app (Smartclic, or ClicNote in Japan) to aid in tracking injections and other treatment or symptom data.

Objectives

The study objective was to collect ease of use and usability data on the Smartclic injector and companion app from experienced patients.

Methods

After completing a patient profiling questionnaire, adult patients (≥18 yrs) from Australia, France, Germany, and Japan with RA, psoriatic arthritis, or an original diagnosis of juvenile idiopathic arthritis who were prescribed an injectable biologic were enrolled in this study. For Japan, only patients with RA were enrolled. Each patient received training individually on the use of the Smartclic injector device and insertable cartridge and gained experience by performing simulated injections. Participants completed a questionnaire with evaluations of the device categories (number of questions): ‘ease of use’ (14), ‘usability effectiveness’ (11), ‘benefit of features’ (8), and ‘form factor’ (7). Participants also separately received a storyboard presentation summarizing the key features of the app, during which patients could explore the app (on a phone with either an android or iOS operating system), and completed 16 questions on the connectivity, usability, and benefit. Responses were recorded as Likert scale ratings from 1 (‘extremely negative’) to 7 (‘extremely positive’). Respondents also provided an estimate of patient training time for the device. Mean values were reported. The percentage of negative (Likert scale rating 1-2), neutral (3-5), and positive (6-7) responses for each category were determined.

Results

A total of 139 patients (mean age [range], 52 [18-84] yrs; 73% female) participated in the study (Table 1). Mean scores (percentage of positive responses) for the device were: ease of use 6.43 (86.2%), usability effectiveness 6.39 (86.5%), benefit of features 6.46 (89.4%), form factor 6.10 (77.2%); and 6.06 (74.2%) for connectivity and benefit of the app (Figure 1). Mean estimated time for training a patient to effectively use the device/cartridge was just under 9.5 min (range, 0-30 min).

Table 1.

Participant characteristics

CharacteristicPatients(N=139)Sex, n (%)Male38 (27)Female101 (73)Mean age (range), yrs52 (18-84)Age groups, n (%)18-30 yrs11 (8)31-59 yrs85 (61)>60 yrs43 (31)Diagnosis, n (%)Rheumatoid arthritis104 (75)Psoriatic arthritis34 (24)Juvenile idiopathic arthritis*1 (1)Handedness, n (%)Right-handed128 (92)Left-handed9 (6)Ambidextrous2 (1)

*Originally diagnosed with juvenile idiopathic arthritis, but now aged ≥18 yrs.

Conclusion

Rheumatology patients responded positively on the new autoinjector device and app across all categories, indicating its suitability for self-administration of biotherapeutics.

Acknowledgements

Medical writing support was provided by Jacob Evans, of Engage Scientific Solutions.

Disclosure of Interests

Rieke Alten Consultant of: AbbVie, Bristol-Myers Squibb, Gilead, Lilly, Novartis, Pfizer and UCB, Grant/research support from: AbbVie, Bristol-Myers Squibb, Galapagos, Gilead, Janssen, Lilly and Pfizer, Mark Latymer Shareholder of: Pfizer, Employee of: Pfizer, David C Gruben Shareholder of: Pfizer, Employee of: Pfizer, Lisa Gunther-LaVergne Employee of: Farm Design, Simon Moss Shareholder of: Pfizer, Employee of: Pfizer, Hideto Kameda Speakers bureau: AbbVie, Asahi-Kasei, Bristol-Myers Squibb, Chugai, Eisai, Janssen, Lilly, Mitsubishi-Tanabe, Novartis and Pfizer, Consultant of: AbbVie, Bristol-Myers Squibb, Janssen, Lilly, Novartis, Sanofi and UCB, Grant/research support from: AbbVie, Asahi-Kasei, Boehringer Ingelheim, Chugai, Eisai and Mitsubishi-Tanabe

1052. Characterisation of the DNA binding properties of ridinilazole, a selective antibiotic currently in phase III trials for the treatment of Clostridioides difficile

Background

Clostridioides difficile infection (CDI) is recognised by the CDC as an “urgent threat” in the USA, responsible for nearly 13,000 deaths, and carries an economic burden ranging from &5.4 to &6.3 billion per year. In a phase II study, ridinilazole was shown to be effective at treating CDI and decreasing subsequent recurrence compared to vancomycin. However, the precise mechanism of action of ridinilazole has yet to be fully elucidated. We now present data that reveals ridinilazole clearly co-localises with DNA in C. difficile and binds with high affinity to the minor groove of DNA. These interactions are predicted to have consequences on cellular functions within C. difficile.

Methods

High resolution confocal microscopy was used to track the intracellular localisation of ridinilazole in C. difficile. Fluorescence intensity was used to characterise the DNA binding properties of ridinilazole; sequence specificity was demonstrated with AT- or GC-rich DNA polymers, and tight binding was shown using short double-stranded oligonucleotides. Hanging drop vapour diffusion enabled co-crystallisation and subsequent structural determination of DNA-bound ridinilazole.

Results

Confocal microscopy revealed clear co-localisation of ridinilazole to the DNA within C. difficile. Ridinilazole demonstrated a dose-dependent increase in fluorescence in response to increasing concentration of target DNA. Fluorescence binding studies revealed that ridinilazole shows a preference towards AT-rich DNA sequences. Tight binding characteristics were demonstrated by ridinilazole in complex with short double-stranded oligonucleotides, returning dissociation constants (Kd) of 20 – 50 nM. Crystallisation enabled co-structures of ridinilazole bound to the minor groove of double-stranded DNA oligonucleotides to be solved.

Conclusion

Ridinilazole demonstrates tight binding with sequence specificity within the minor groove of DNA and co-localises with DNA in C. difficle. Further analysis is ongoing to fully understand this novel mechanism of action, the downstream consequences of these interactions and how they contribute to the bactericidal activity of ridinilazole.

Disclosures

Clive Mason, PhD, Summit Therapeutics (Employee, Shareholder) Tim Avis, n/a, Summit therapeutics (Shareholder) Chris Coward, PhD, Summit Therapeutics (Employee, Scientific Research Study Investigator, Shareholder) David Powell, PhD, Summit Therapeutics (Employee) Kevin W. Garey, Pharm.D., M.S., FASHP, Summit Therapeutics (Research Grant or Support)

Melting of hybrid organic-inorganic perovskites

Several organic-inorganic hybrid materials from the metal-organic framework (MOF) family have been shown to form stable liquids at high temperatures. Quenching then results in the formation of melt-quenched MOF glasses that retain the three-dimensional coordination bonding of the crystalline phase. These hybrid glasses have intriguing properties and could find practical applications, yet the melt-quench phenomenon has so far remained limited to a few MOF structures. Here we turn to hybrid organic-inorganic perovskites-which occupy a prominent position within materials chemistry owing to their functional properties such as ion transport, photoconductivity, ferroelectricity and multiferroicity-and show that a series of dicyanamide-based hybrid organic-inorganic perovskites undergo melting. Our combined experimental-computational approach demonstrates that, on quenching, they form glasses that largely retain their solid-state inorganic-organic connectivity. The resulting materials show very low thermal conductivities (~0.2 W m^-1 K^-1), moderate electrical conductivities (10^-3-10^-5 S m^-1) and polymer-like thermomechanical properties.

Influence of Lipophilicity on the Antibacterial Activity of Polymyxin Derivatives and on Their Ability to Act as Potentiators of Rifampicin

Novel polymyxin derivatives are often classified either as having direct activity against Gram-negative pathogens or as compounds inactive in their own right, which through permeabilization of the outer membrane act as potentiators of other antibiotics. Here, we report the systematic investigation of the influence of lipophilicity on microbiological activity (including against strains with reduced susceptibility to polymyxins), potentiation of rifampicin, and in vitro toxicity within a series of next-generation polymyxin nonapeptides. We demonstrate that the lipophilicity at the N-terminus and amino acids 6 and 7 in the cyclic peptide core is interchangeable and that the activity, ability to potentiate, and cytotoxicity all appear to be primarily driven by overall lipophilicity. Our work also suggests that the characterization of a polymyxin molecule as either a direct acting compound or a potentiator is more of a continuum that is strongly influenced by lipophilicity rather than as a result of fundamentally different modes-of-action.

Treating children with disinhibited social engagement disorder symptoms: Filial therapy

Introduction

Children affected by social neglect and other forms of abuse are at significant risk of developing mental health problems as well as social, academic, and behavioral functioning difficulties. Some studies have assessed the effectiveness of treatment for children with trauma-attachment disorder. Nevertheless, some questions remain to be answered regarding appropriate treatment.

Objectives

Aim This research identified how filial therapy affects the extent to which foster parents are responsive, sensitive, and attentive to the needs of their children in their care. Subsequently, the study explored how this bond, influenced during filial therapy, affects the signs and symptoms of disinhibited social engagement disorder.

Methods

Method This study used case study as the methodology to research the influence of filial therapy (CPRT) in foster children who show the symptoms of disinhibited social engagement disorder- aged three to six. Two sets of foster parents received a 10-session filial therapy model (CPRT) across 10 weeks. Pre and post measures of the parent-child relationship were analyzed.

Results

Result The findings indicate that filial therapy greatly enhances the bond between foster parents and children with DSEDs. Moreover, these improvements in the bond diminished the symptoms of disinhibited social engagement disorder.

Conclusions

Conclusion The impact of filial therapy as a responsive intervention reduced the symptoms of disinhibited social engagement disorder. The symptoms have declined very likely as a result of rebuilding, regenerating, and enhancing the relationship between foster children and foster parents.

Disclosure

No significant relationships.

Treatment with interleukin-33 is non-toxic and protects retinal pigment epithelium in an ageing model of outer retinal degeneration

The leading cause of central vision loss, age‐related macular degeneration (AMD), is a degenerative disorder characterized by atrophy of retinal pigment epithelium (RPE) and photoreceptors. For 15% of cases, neovascularization occurs, leading to acute vision loss if left untreated. For the remaining patients, there are currently no treatment options and preventing progressive RPE atrophy remains the main therapeutic goal. Previously, we have shown treatment with interleukin‐33 can reduce choroidal neovascularization and attenuate tissue remodelling. Here, we investigate IL‐33 delivery in aged, high‐fat diet (HFD) fed mice on a wildtype and complement factor H heterozygous knockout background. We characterize the non‐toxic effect following intravitreal injection of IL‐33 and further demonstrate protective effects against RPE cell death with evidence of maintaining metabolic retinal homeostasis of Cfh+/−~HFD mice. Our results further support the potential utility of IL‐33 to prevent AMD progression.

Detection and characterization of resistance to acetolactate synthase inhibiting herbicides in Anisantha and Bromus species in the United Kingdom

BACKGROUND

Anisantha and Bromus spp. are widespread and difficult to control, potentially due to the evolution of herbicide resistance. In this study, UK populations of four brome species have been tested for the early development of resistance to acetolactate synthase (ALS)-inhibiting herbicides commonly used in their control.

RESULTS

Glasshouse assays confirmed reduced sensitivity to ALS-inhibiting herbicides in single populations of A. diandra, B. commutatus and B. secalinus, and in three populations of A. sterilis. By contrast, all 60 brome populations tested were sensitive to the ACCase-inhibiting herbicide propaquizafop and glyphosate. Dose-response with two ALS herbicides showed broad-ranging resistance in the A. diandra, A. sterilis and B. commutatus populations. In the B. commutatus population, this was associated with a point mutation in the ALS enzyme conferring target site resistance (TSR). Additionally, resistant populations of A. sterilis and B. commutatus populations contained enhanced amounts of an orthologue of the glutathione transferase phi (F) class 1 (GSTF1) protein, a functional biomarker of nontarget site resistance (NTSR) in Alopecurus myosuroides. There was further evidence of NTSR as these plants also demonstrated an enhanced capacity to detoxify herbicides.

CONCLUSION

This study confirms the evolution of resistance to ALS inhibiting herbicides in brome species in the UK by mechanisms consistent with the evolution of both TSR and NTSR. These findings point to the need for increased vigilance in detecting and mitigating against the evolution of herbicide resistance in brome species in Northern Europe. © 2020 Society of Chemical Industry.

Furo[3,2-c]coumarin-derived Fe3+ Selective Fluorescence Sensor: Synthesis, Fluorescence Study and Application to Water Analysis

Furocoumarin (furo[3,2-c]coumarin) derivatives have been synthesized from single step, high yielding (82-92%) chemistry involving a 4-hydroxycoumarin 4 + 1 cycloaddition reaction. They are characterized by FTIR, 1H-NMR, and, for the first time, a comprehensive UV-Vis and fluorescence spectroscopy study has been carried out to determine if these compounds can serve as useful sensors. Based on the fluorescence data, the most promising furocoumarin derivative (2-(cyclohexylamino)-3-phenyl-4H-furo[3,2-c]chromen-4-one, FH), exhibits strong fluorescence (ФF = 0.48) with long fluorescence lifetime (5.6 ns) and large Stokes' shift, suggesting FH could be used as a novel fluorescent chemosensor. FH exhibits a highly selective, sensitive and instant turn-off fluorescence response to Fe3+ over other metal ions which was attributed to a charge transfer mechanism. Selectivity was demonstrated against 13 other competing metal ions (Na+, K+, Mg2+, Ca2+, Mn2+, Fe2+, Al3+, Ni2+, Cu2+, Zn2+, Co2+, Pb2+ and Ru3+) and aqueous compatibility was demonstrated in 10% MeOH-H2O solution. The FH sensor coordinates Fe3+ in a 1:2 stoichiometry with a binding constant, Ka = 5.25 × 103 M-1. This novel sensor has a limit of detection of 1.93 µM, below that of the US environmental protection agency guidelines (5.37 µM), with a linear dynamic range of ~28 (~2-30 µM) and an R2 value of 0.9975. As an exemplar application we demonstrate the potential of this sensor for the rapid measurement of Fe3+ in mineral and tap water samples demonstrating the real-world application of FH as a "turn off" fluorescence sensor.

Direct modifications of the cyclic peptide Polymyxin B leading to analogues with enhanced in vitro antibacterial activity

Synthetic modifications have been made directly to the cyclic peptide core of polymyxin B, enabling the further understanding of structure activity relationships of this antimicrobial peptide. Such modified polymyxins are also substrates for enzymic hydrolysis, enabling the synthesis of a variety of semi-synthetic analogues, resulting in compounds with increased in vitro antibacterial activity.

Benchmarking nurse outcomes in Australian Magnet® hospitals: cross-sectional survey

Background

Positive reports of nursing-related outcomes such as quality nursing care, nursing engagement with work and good practice environment are crucial in attaining and maintaining Magnet® designation. The majority of Magnet®-designated organisations (N = 482) are in the USA, with their aggregate nursing outcomes widely published as benchmark data. Australian Magnet® outcomes have not been aggregated or published to date.

Methods

The aims are to benchmark educational preparation, occupational burnout, job satisfaction, intention to leave and working environment of nurses in Australian Magnet®-designated facilities and to determine the reliability of the Practice Environment Scale-Australia.

The design is a cross-sectional multisite survey set in all three Australian Magnet®-designated organisations.

The demographics included age, gender, level of education, years in practice, level of seniority and position title. Two items measured job satisfaction and intent to stay in current employment. The Maslach Burnout Inventory explored the three domains of nursing engagement: depersonalisation, personal achievement and emotional exhaustion. The Australian version of the Practice Environment Scale interrogated participants’ perceptions of their work environments.

Results

2004 nurses participated (response rate 45.9%). Respondents’ mean age was 39.2 years (range 20–72). They were predominantly female and had worked in their current facility for more than 5 years. Eighty five percent had a minimum of a Bachelor’s degree. Eighty-six percent of respondents were satisfied or very satisfied with their current position. Eighty eight percent had no intention of leaving their current employer within the next 12 months. Participants rated their hospitals highly in all domains of the practice environment. Respondents reported less burnout in the personal accomplishment and depersonalisation domains than in the emotional exhaustion domain, in which they reported average levels of burnout. The internal consistency of the Practice Environment Scale-Australia was confirmed in this sample (Cronbach α’s 0.87–0.9 for subscales and 0.89 for composite score).

Conclusion

In this paper, we present nursing outcome data from all Australian Magnet® hospitals for the first time. This provides a benchmark that facilitates comparison with nursing outcomes published by Australian non-Magnet® hospitals and with international Magnet® organisations.

Design of Next Generation Polymyxins with Lower Toxicity: The Discovery of SPR206

Polymyxins are an important class of antibiotics for the treatment of bacterial infections due to multidrug resistant Gram-negative pathogens. However, their clinical utility is limited by nephrotoxicity. Here, we report a series of promising next generation polymyxin nonapeptides identified on the basis of our understanding of the relationship of structure with activity, cytotoxicity, and kidney compartment accumulation. We demonstrate that nonapeptides with an amine-containing N-terminal moiety of specific regio- and stereochemistry possess superior in vitro activity, together with lower cytotoxicity compared to polymyxin B. We further demonstrate that compounds with a β-branched aminobutyrate N-terminus with an aryl substituent offer a promising combination of low cytotoxicity and kidney exposure, leading to low toxicity in the mouse. From this series, SPR206 has been selected as a development candidate.

Crystal structure of peptide-bound neprilysin reveals key binding interactions

Neprilysin (NEP) is a promiscuous zinc metalloprotease with broad substrate specificity and cleaves a remarkable diversity of substrates through endopeptidase action. Two of these - amyloid-β and natriuretic peptides - implicate the enzyme in both Alzheimer's disease and cardiovascular disease, respectively. Here, we report the creation of a catalytically inactive NEP (E584D) to determine the first peptide-bound crystal structure at 2.6 Å resolution. The structure reveals key interactions involved in substrate binding which we have identified to be conserved in other known zinc metalloproteases. In addition, the structure provides evidence for a potential exosite within the central cavity that may play a critical role in substrate positioning. Together, these results contribute to our understanding of the molecular function of NEP.

Tool inhibitors and assays to interrogate the biology of the TRAF2 and NCK interacting kinase

The TRAF2 and NCK interacting kinase (TNIK) has been proposed to play a role in cytoskeletal organization and synaptic plasticity and has been linked, among others, to neurological disorders. However, target validation efforts for TNIK have been hampered by the limited kinase selectivity of small molecule probes and possible functional compensation in mouse models. Both issues are at least in part due to its close homology to the kinases MINK1 (or MAP4K6) and MAP4K4 (or HGK). As part of our interest in validating TNIK as a therapeutic target for neurological diseases, we set up a panel of biochemical and cellular assays, which are described herein. We then examined the activity of known amino-pyridine-based TNIK inhibitors (1, 3) and prepared structurally very close analogs that lack the ability to inhibit the target. We also developed a structurally orthogonal, naphthyridine-based TNIK inhibitor (9) and an inactive control molecule of the same chemical series. These validated small-molecule probes will enable dissection of the function of TNIK family in the context of human disease biology.

Integrated weed management (IWM): why are farmers reluctant to adopt non-chemical alternatives to herbicides?

Implementation of integrated weed management (IWM) has been poor, with little evidence of concomitant reductions in herbicide use. Non-chemical methods are often adopted as a means of compensating for reduced herbicide efficacy, due to increasing resistance, rather than as alternatives to herbicides. Reluctance to adopt non-chemical methods is not due to a lack of research or technology but to a lack of farmer motivation and action. Justifiably, herbicides are often seen as the easier option - their convenience outweighs the increased complexity, costs and management time associated with non-chemical alternatives. Greater use of non-chemical alternatives to herbicides will only occur if the following seven aspects are addressed: (i) better recognition of the reasons why farmers are reluctant to use non-chemical alternatives; (ii) encouraging farmers to adopt a longer-term approach to weed control; (iii) changing farmers' attitudes to pesticides; (iv) paying more attention to the individual farmer's perspective; (v). greater involvement of economists, social scientists and marketing professionals; (vi) re-evaluating research and extension priorities; and (vii) changing the mindset of funders of research and extension. If 'persuasion' fails to deliver greater implementation of IWM, authorities may resort to greater use of financial and other incentives combined with tougher regulations. © 2018 Society of Chemical Industry.

Final Results of the Prospective FH02 Mammographic Surveillance Study of Women Aged 35-39 at Increased Familial Risk of Breast Cancer

BACKGROUND

Many women who are at increased risk of breast cancer due to a mother or sister diagnosed with breast cancer aged under 40 do not currently qualify for surveillance before 40 years of age. There are almost no available data to assess whether mammography screening aged 35-39 years would be effective in this group, in terms of detection of breast cancer at an early stage or cost effective.

METHODS

A cohort screening study (FH02) with annual mammography was devised for women aged 35-39 to assess the sensitivity and screening performance and potential survival of women with identified tumours.

FINDINGS

2899 women were recruited from 12/2006-12/2015. These women underwent 12,086 annual screening mammograms and were followed for 13,365.8 years. A total of 55 breast cancers in 54 women occurred during the study period (one bilateral) with 50 cancers (49 women) (15 CIS) adherent to the screening. Eighty percent (28/35) of invasive cancers were ≤ 2 cm and 80% also lymph node negative. Invasive cancers diagnosed in FH02 were significantly smaller than the comparable (POSH-unscreened prospective) study group (45% (131/293) ≤ 2 cm in POSH vs 80% (28/35) in FH02 p < 0.0001), and were less likely to be lymph-node positive (54% (158/290, 3 unknown) in POSH vs 20% (7/35) in FH02: p = 0.0002. Projected and actual survival were also better than POSH. Overall radiation dose was not higher than in an older screened population at mean dose on study per standard sized breast of 1.5 mGy.

INTERPRETATION

Mammography screening aged 35-39 years detects breast cancer at an early stage and is likely to be as effective in reducing mortality as in women at increased breast cancer risk aged 40-49 years.

Abstract 5757: Preclinical development and testing of a therapeutic antibody against LRG1

Introduction: The purpose of this study was to generate a therapeutic function-blocking antibody against leucine-rich alpha-2-glycoprotein 1 (LRG1), a novel regulator of pathological angiogenesis that is up-regulated in many cancers, and demonstrate efficacy in proof of principle experiments in mouse models.

Experimental Procedures: Mice were immunized with recombinant human LRG1 and hybridomas generated. More than 100 monoclonal antibodies (mAbs) were first screened by surface plasmon resonance (SPR) to measure affinity for target, and then in a co-culture angiogenesis assay to evaluate functional activity. The most promising candidates were then tested in vivo in the mouse model of laser-induced choroidal neovascularization, and from this study a lead was humanized and deimmunized. The resulting antibody is a hinge-stabilized IgG4 that is now undergoing manufacturing and pre-clinical safety and toxicology testing.

Results: Of the original set of mouse mAbs, an initial screen to eliminate low affinity (KD greater than 1nM) binders resulted in 25 progressing to functional testing in angiogenesis assays. The seven most effective blocking mAbs were then tested in vivo in the mouse model of laser-induced choroidal neovascularization. Intraocular injections of mAb yielded two that exhibited equivalent inhibition of neovascularization to a therapeutic VEGF-blocker, and of these, the higher affinity mAb (15C4) was selected for humanization. Epitope mapping identified an amino-acid sequence within human LRG1, that in the form of a synthetic peptide was able to compete the binding of 15C4 to LRG1. Multiple species sequence alignment revealed the epitope to be partially conserved with the corresponding mouse sequence, and SPR analysis showed that 15C4 binding to recombinant mouse LRG1 was several orders of magnitude lower than to human LRG1. Nevertheless, administration of 15C4 to tumor-bearing mice significantly inhibited tumor growth in a range of subcutaneous and genetic models. Furthermore, due to the vessel normalizing effects of 15C4, combinations of mAb with both immunotherapy and cytotoxics were significantly more effective at restricting tumor growth than either monotherapy.

Conclusions: We have generated and characterized a novel vessel-normalizing, fully humanized function-blocking mAb against LRG1 that shows efficacy in mouse tumor models. GMP manufacture is on-going, and early stage clinical trials are planned in 2019.

Financial Support: The work was supported by the Medical Research Council, the Rosetrees Trust and UCL Business.

Citation Format: Stephen Moss, David Kallenberg, Vineeta Tripathi, Sterenn Davis, Jestin George, Marie O'Connor, Laura Dowsett, John Greenwood. Preclinical development and testing of a therapeutic antibody against LRG1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5757.

Changes in the proteome of the problem weed blackgrass correlating with multiple-herbicide resistance

Herbicide resistance in grass weeds is now one of the greatest threats to sustainable cereal production in Northern Europe. Multiple-herbicide resistance (MHR), a poorly understood multigenic and quantitative trait, is particularly problematic as it provides tolerance to most classes of chemistries currently used for post-emergence weed control. Using a combination of transcriptomics and proteomics, the evolution of MHR in populations of the weed blackgrass (Alopecurus myosuroides) has been investigated. While over 4500 genes showed perturbation in their expression in MHR versus herbicide sensitive (HS) plants, only a small group of proteins showed >2-fold changes in abundance, with a mere eight proteins consistently associated with this class of resistance. Of the eight, orthologues of three of these proteins are also known to be associated with multiple drug resistance (MDR) in humans, suggesting a cross-phyla conservation in evolved tolerance to chemical agents. Proteomics revealed that MHR could be classified into three sub-types based on the association with resistance to herbicides with differing modes of action (MoA), being either global, specific to diverse chemistries acting on one MoA, or herbicide specific. Furthermore, the proteome of MHR plants were distinct from that of HS plants exposed to a range of biotic (insect feeding, plant-microbe interaction) and abiotic (N-limitation, osmotic, heat, herbicide safening) challenges commonly encountered in the field. It was concluded that MHR in blackgrass is a uniquely evolving trait(s), associated with changes in the proteome that are distinct from responses to conventional plant stresses, but sharing common features with MDR in humans.

Effects of Gabra2 Point Mutations on Alcohol Intake: Increased Binge-Like and Blunted Chronic Drinking by Mice

BACKGROUND

Alcohol use disorders are associated with single-nucleotide polymorphisms in GABRA2, the gene encoding the GABA_A receptor α2-subunit in humans. Deficient GABAergic functioning is linked to impulse control disorders, intermittent explosive disorder, and to drug abuse and dependence, yet it remains unclear whether α2-containing GABA_A receptor sensitivity to endogenous ligands is involved in excessive alcohol drinking.

METHODS

Male wild-type (Wt) C57BL/6J and point-mutated mice rendered insensitive to GABAergic modulation by benzodiazepines (BZD; H101R), allopregnanolone (ALLO) or tetrahydrodeoxycorticosterone (THDOC; Q241M), or high concentrations of ethanol (EtOH) (S270H/L277A) at α2-containing GABA_A receptors were assessed for their binge-like, moderate, or escalated chronic drinking using drinking in the dark, continuous access (CA) and intermittent access (IA) to alcohol protocols, respectively. Social approach by mutant and Wt mice in forced alcohol abstinence was compared to approach by EtOH-naïve controls. Social deficits in forced abstinence were treated with allopregnanolone (0, 3.0, 10.0 mg/kg, intraperitoneal [i.p.]) or midazolam (0, 0.56, 1.0 mg/kg, i.p.).

RESULTS

Mice with BZD-insensitive α2-containing GABA_A receptors (H101R) escalated their binge-like drinking. Mutants harboring the Q241M point substitution in Gabra2 showed blunted chronic intake in the CA and IA protocols. S270H/L277A mutants consumed excessive amounts of alcohol but, unlike wild-types, they did not show forced abstinence-induced social deficits.

CONCLUSIONS

These findings suggest a role for: (i) H101 in species-typical binge-like drinking, (ii) Q241 in escalated chronic drinking, and (iii) S270 and/or L277 in the development of forced abstinence-associated social deficits. Clinical findings report reduced BZD-binding sites in the cortex of dependent patients; the present findings suggest a specific role for BZD-sensitive α2-containing receptors. In addition, amino acid residue 241 in Gabra2 is necessary for positive modulation and activation of GABA_A receptors by ALLO and THDOC; we postulate that neurosteroid action on α2-containing receptor may be necessary for escalated chronic EtOH intake.

Budner's Intolerance of Ambiguity: A Note concerning Intelligence

Budner's measure of intolerance of ambiguity has been applied as an explanatory device for a wide variety of behavioral phenomena. Data from 100 high school girls, given several scales, indicate a strong component of ability in the scores. The role of intelligence in studies of intolerance of ambiguity has been neglected; conceptual clarification of the issue appears warranted.

GPs views and understanding of PSA testing, screening and early detection; survey

BACKGROUND

There is currently no national prostate cancer screening programme in the UK. However, patients 50 years and older are entitled to a prostate specific antigen (PSA) test, if informed on the advantages and disadvantages of testing and their risk of cancer. The Prostate Cancer Risk Management Programme (PCRMP) provides this guidance.

AIM

The aim of this study was to access GPs' views and understanding of PSA testing, prostate cancer screening and early detection.

METHOD

A total of 708 questionnaires were returned by GPs across two English regions in 2013 and the GP questionnaire responses were quantitatively analysed.

RESULTS

In the 699 completed questionnaires, the majority of GPs were well informed about PSA testing, screening and early detection. Only 32% used guidelines for referral, 14% knew all age-specific PSA referral levels, 71% that Black men have a higher prostate cancer risk than White men (22% correctly answered threefold increase) and 82% that family history is a risk factor. A further 78% thought electronic prompts during consultation would encourage PCRMP guideline usage and 75% had never been offered a PSA test and prostate cancer educational course, of which 73% would like to attend a course. Only 23% were aware of the latest PSA screening evidence and 94% would like an update.

CONCLUSIONS

Participating GPs seem to be well informed but need more information and tools to help follow recommended guidance. In particular, increased awareness of PCRMP guidelines especially by automated methods, further educational courses and evidence updates would be beneficial.

Prostate-specific antigen testing rates and referral patterns from general practice data in England

BACKGROUND

There is currently no national screening programme for prostate cancer in England, but eligible men can request a prostate-specific antigen (PSA) test from their general practitioner (GP). There are no routinely available data to monitor the extent of PSA testing and referral.

AIM

The aim of this study was to investigate the rate of PSA testing in general practice and subsequent patterns of referral.

DESIGN AND SETTING

Data obtained from the Clinical Practice Research Datalink (CPRD) for men aged 45-84 years who had a PSA test during 2010-2011, registered in practices in England with linked Hospital Episode Statistics (HES) data.

METHOD

Patient data were linked to previous tests and consultations. Rates of PSA testing and proportions of men retested and referred to secondary care were calculated.

RESULTS

Overall, 8.74 (95% CI 8.67-8.82) of men per 100 person-years were tested at least once in 2010, and 9.45 (95% CI 9.37-9.53) in 2011. Rates increased with age and decreased with increasing level of deprivation. Of the 53,069 men tested in 2010, 11,289 (21.3%) had a previous PSA test within the past 12 months. Of men with raised PSA according to age specific guidelines, 22.4% (2113/9425) were referred to secondary care within 14 days, with 36% of the remainder retested within 6 months.

CONCLUSIONS

Rates of PSA testing have increased compared with earlier studies; the data suggest that many GPs are retesting men with raised PSA rather than referring immediately. More routine data on PSA testing, including reasons for testing, and subsequent management and outcomes, are required.

Equine grass sickness, but not botulism, causes autonomic and enteric neurodegeneration and increases soluble N-ethylmaleimide-sensitive factor attachment receptor protein expression within neuronal perikarya

REASONS FOR PERFORMING STUDY

Equine grass sickness (EGS) is of unknown aetiology. Despite some evidence suggesting that it represents a toxico-infection with Clostridium botulinum types C and/or D, the effect of EGS on the functional targets of botulinum neurotoxins, namely the soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins, is unknown. Further, while it is commonly stated that, unlike EGS, equine botulism is not associated with autonomic and enteric neurodegeneration, this has not been definitively assessed.

OBJECTIVES

To determine: 1) whether botulism causes autonomic and enteric neurodegeneration; and 2) the effect of EGS on the expression of SNARE proteins within cranial cervical ganglion (CCG) and enteric neuronal perikarya.

STUDY DESIGN

Descriptive study.

METHODS

Light microscopy was used to compare the morphology of neurons in haematoxylin-eosin stained sections of CCG and ileum from 6 EGS horses, 5 botulism horses and 6 control horses. Immunohistochemistry was used to compare the expression of synaptosomal-associated protein-25, synaptobrevin (Syb) and syntaxin within CCG neurons, and of Syb in enteric neurons, from horses with EGS, horses with botulism and control horses. The concentrations of these SNARE proteins in extracts of CCG from EGS and control horses were compared using quantitative fluorescent western blotting.

RESULTS

EGS, but not botulism, was associated with autonomic and enteric neurodegeneration and with increased immunoreactivity for SNARE proteins within neuronal perikarya. Quantitative fluorescent western blotting confirmed increased concentrations of synaptosomal-associated protein-25, Syb and syntaxin within CCG extracts from EGS vs. control horses, with the increases in the latter 2 proteins being statistically significant.

CONCLUSIONS

The occurrence of autonomic and enteric neurodegeneration, and increased expression of SNARE proteins within neuronal perikarya, in EGS but not botulism, suggests that EGS may not be caused by botulinum neurotoxins. Further investigation of the aetiology of EGS is therefore warranted.

Mammographic surveillance in women aged 35-39 at enhanced familial risk of breast cancer (FH02)

Although there have been encouraging recent studies showing a potential benefit from annual mammography in women aged 40-49 years of age with an elevated breast cancer risk due to family history there is little evidence of efficacy in women aged <40 years of age. A prospective study (FH02) has been developed to assess the efficacy of mammography screening in women aged 35-39 years of age with a lifetime breast cancer risk of ≥ 17 % who are not receiving MRI screening. Retrospective analyses from five centres with robust recall systems identified 47 breast cancers (n = 12 in situ) with an interval cancer rate of 15/47 (32%). Invasive tumour size, lymph node status and current vital status were all significantly better than in two control groups of unscreened women (including those with a family history) recruited to the POSH study. Further evaluation of the prospective arm of FH02 is required to assess the potential added value of digital mammography and the cancer incidence rates in moderate and high risk women in order to inform cost effectiveness analyses.

Physical and physiological characteristics in male team handball players by playing position - Does age matter?

AIM

The purpose of this study was to examine the variation in physical and physiological characteristics according to playing position in adolescent and adult male team handball (TH) players.

METHODS

Adolescent (N.=57, aged 14.9±1.4 yr) and adult (N.=39, 26.6±5.7 yr) players were examined for anthropometric characteristics, somatotype and body composition, and performed the physical working capacity test, a force-velocity test, the Wingate anaerobic test (WAnT), sit-and-reach test, handgrip strength test, squat jump (SJ), countermovement vertical jump without (CMJ) and with arm-swing, and a 30-s Bosco test. Eccentric utilization ratio (EUR) was calculated as the ratio CMJ to SJ.

RESULTS

In adult players, there were significant differences between wings and the other positions with regard to anthropometric and body composition parameters (body mass, -17.9% to -13.2%; height, -5.3% to -4.3%; and fat-free mass, -13.7% to -9.9%) and anaerobic power assessed by WAnT (peak power, -20.5% to -15.2%; and mean power, -20% to -14.8%); however, these characteristics did not differ significantly in adolescents, in which the only statistically significant difference was found between goalkeepers and the other positions in EUR (+8.1%).

CONCLUSION

Therefore, the differences in physical and physiological characteristics between playing positions are age-dependent. As adult players in this study were taken from players competing in the top Greek league, findings could serve as a base for talent identification and development for future studies. Moreover, knowledge about positional differences might enhance the ability to make tailored position-specific training programs among adult and adolescent players in the future.

Accountability versus blame

The exam question “Who should be held to account for the delivery of safe, effective and compassionate care?”