Performance of a System for Rapid Phenotypic Antimicrobial Susceptibility Testing of Gram-Negative Bacteria Directly from Positive Blood Culture Bottles

The rapid administration of optimal antimicrobial treatment is paramount for the treatment of bloodstream infections (BSIs), and rapid antimicrobial susceptibility testing (AST) results are essential. Q-linea has developed the ASTar system, a rapid phenotypic AST device. Here, we report the performance of the ASTar BC G- (Gram-negative) kit when assessed according to the ISO 20776-2:2007 standard for performance evaluation of in vitro diagnostic AST devices. The evaluated ASTar BC G- kit uses a broad panel of 23 antimicrobials for the treatment of BSIs caused by Gram-negative fastidious and nonfastidious bacteria across a range of 6 to 14 2-fold dilutions, including cefoxitin as a screening agent for AmpC-producing Enterobacterales. The ASTar system processes blood culture samples to generate data on MICs and susceptible, intermediate, or resistant (SIR) category. The automated protocol includes concentration determination and concentration adjustment to enable a controlled inoculum, followed by broth microdilution (BMD) and microscopy performed continuously to generate MIC values within approximately 6 h once the test is run on the ASTar system. The performance of the ASTar system was assessed against the ISO 20776-2:2007 standard BMD reference method. Testing was performed across three sites, with results from 412 contrived blood cultures and 74 fresh clinical blood cultures. The ASTar system was also tested for reproducibility, with triplicate testing of 11 strains. The accuracy study comprised 8,650 data points of bacterium-antimicrobial tests. The ASTar system demonstrated an overall essential agreement (EA) of 95.8% (8,283/8,650) and a categorical agreement (CA) of 97.6% (8,433/8,639) compared to the reference BMD method. The overall rate of major discrepancies (MDs) was 0.9% (62/6,845), and that of very major discrepancies (VMDs) was 2.4% (30/1,239). This study shows that the ASTar system delivers reproducible results with overall EA and CA of >95%.

Frontal Brain Activity and Subjective Arousal During Emotional Picture Viewing in Nightmare Sufferers

Nightmares are intensely negative dreams that awaken the dreamer. Frequent nightmares are thought to reflect an executive deficit in regulating arousal. Within a diathesis-stress framework, this arousal is specific to negative contexts, though a differential susceptibility framework predicts elevated arousal in response to both negative and positive contexts. The current study tested these predictions by assessing subjective arousal and changes in frontal oxyhemoglobin (oxyHB) concentrations during negative and positive picture-viewing in nightmare sufferers (NM) and control subjects (CTL). 27 NM and 27 CTL subjects aged 18–35 rated subjective arousal on a 1–9 scale following sequences of negative, neutral and positive images; changes in oxyHB were measured by Near-Infrared Spectroscopy (NIRS) using a 2 × 4 template on the frontal pole. Participants also completed the Highly Sensitive Person Scale, a trait marker for differential susceptibility; and completed a dream diary reporting negative and positive dream emotionality. The NM group had higher trait sensitivity, yet higher ratings of negative but not positive emotion in diary dreams. NM compared to CTL subjects reported higher subjective arousal in response to picture-viewing regardless of valence. Dysphoric dream distress, measured prospectively, was negatively associated with frontal activation when viewing negative pictures. Results suggest NM sufferers are highly sensitive to images regardless of valence according to subjective measures, and that there is a neural basis to level of trait and prospective nightmare distress. Future longitudinal or intervention studies should further explore positive emotion sensitivity and imagery in NM sufferers.

Health experiences of asylum seekers and refugees in Wales

Key messages

Improving health equity is key to realising Wales’ ambition to become a Nation of Sanctuary. Peer Researchers enabled participation by sanctuary seekers and revealed useful findings to steer future policy and practice.

P5308Mediterranean-style diet for the primary and secondary prevention of cardiovascular disease: Cochrane systematic review and meta-analysis of randomised clinical trials

Background

Observational studies have confirmed the benefits of adherence to a Mediterranean dietary pattern on cardiovascular disease (CVD) but the randomised controlled trial (RCT) evidence is limited.

Objective

To determine the effectiveness of a Mediterranean-style diet for the primary and secondary prevention of CVD.

Methods

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Web of Science, DARE, HTA, NHS EED and trial registers (September 2018). We selected RCTs in healthy adults and adults at high risk of CVD (primary prevention) and those with established CVD (secondary prevention). Both of the following key components were required for our definition of a Mediterranean-style diet: high monounsaturated/saturated fat ratio and a high intake of plant based foods, including fruits, vegetables, and legumes. The intervention could be dietary advice, provision of relevant foods or both. The comparison group received either no intervention, minimal intervention, usual care or another dietary intervention. Outcomes included clinical events and CVD risk factors. We included only studies with follow-up periods of 3 months or more.

Results

Overall, 30 RCTs (12,461 participants randomised) and 7 ongoing trials met our inclusion criteria, whereas 22 primary prevention trials and 6 secondary prevention trials were analysed. Low quality evidence shows little or no effect of the PREDIMED (7747 randomised) intervention (advice to follow a Mediterranean diet plus supplemental extra virgin olive oil or tree nuts) compared to a low fat diet on CVD mortality (HR 0.81 (95% CI 0.5, 1.32)) or total mortality (HR 1.0 (95% CI 0.81, 1.24)) over 4.8 years. There was however a reduction in the number of strokes with the PREDIMED intervention (HR 0.6 (95% CI 0.45, 0.8), moderate quality evidence). For secondary prevention, in the Lyon Diet Heart Study (605 CVD patients), there was moderate quality evidence of a reduction in CVD mortality (HR 0.35 (95% CI 0.15, 0.82)) and total mortality (HR 0.44 (95% CI 0.21, 0.92)) with the intervention, over 46 months. For CVD risk factors, in primary prevention trials, there was low quality evidence for a possible small reduction in total cholesterol (−0.16 mmol/L (95% CI −0.32, 0.00), and moderate quality evidence for a reduction in SBP (−2.99 mmHg (95% CI −3.45, −2.53)) and DBP (−2.0 mmHg (95% CI −2.29, −1.71)). In secondary prevention trials, there was moderate quality evidence of no effect of a Mediterranean-style diet on lipid levels and low or very low quality evidence for blood pressure.

Conclusions

Despite the relatively large number of studies included in this review, there is still some uncertainty regarding the effects of a Mediterranean-style diet on clinical endpoints and CVD risk factors for both primary and secondary prevention. The ongoing studies may provide more certainty in the future.

Abstract P1-02-03: The Y537S ESR1 mutation carries unique metabolomics profiling in breast cancer

Background:

Estrogen receptor (ESR1) mutations occur at a high frequency in metastatic breast tumors in patients treated with hormonal therapy in the metastatic setting. We do not know if these mutations changed metabolomics and whether these metabolomics change could affect metastasis.

Experimental design and methods:

We generated ESR1 Y537S homozygous mutations using CRISPR Casp-9 technology. Globe metabolites screening was performed using 6550 Agilent QTOF instrument. Athymic mice were used in tumor xenograft studies. Affymetrix microarrays were performed to compare gene expression changes in Y537S mutant compared with parental cells. Enriched metabolite pathways and gene expression integrated analysis was analyzed by using online analysis tool http://www.metaboanalyst.ca.

Results:

We generated CRISPR ESR1 Y537S mutation homozygous knock-in clones in MCF-7 cells. In vivo experiments revealed that mutant cells are dominant drivers of metastasis. Transcriptome profiling revealed elevated expression of Hallmark pathways, including EMT and estrogen-regulated gene expression. We performed globe metabolites screening using MCF-7 Y537S and MCF-7 parental and identified 134 metabolites. Serum starvation media was used and estrogen was used as control for both cell lines. As we expected estrogen treatment induced metabolites changes in parental cells. However, metabolites in mutant cells were not changed significantly under estrogen treatment. Interestingly, metabolites in the mutant cells at baseline were remarkably upregulated (78 out of 134 identified total metabolites) indicating mutant cells in serum starvation condition had significantly different metabolomics compared with parental cells. Top upregulated pathways include protein biosynthesis, betaine metabolism and ammonia recycling. Integration of microarray gene expression and metabolites reviewed several metabolomics pathways significantly changed in mutant compared with parental cells including for example aminoacyl-tRNA biosynthesis, arginine and proline metabolism and alanine, aspartate and glutamate metabolism.

Conclusion: The Y537S ER mutation is a driver of distant metastasis in ER-positive breast cancer cells. Y537S ER mutant had globe changes of metabolites expression which was confirmed by integrated analysis combining microarray gene expression. The roles of these metabolites need to be studied to correlate with metastasis. Enzymes responsible for converting these metabolites changes could be served as potential therapeutic targets.

Citation Format: Gu G, Piyarathna B, Coarfa C, Ellis L, Ando' S, Fuqua S. The Y537S ESR1 mutation carries unique metabolomics profiling in breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-02-03.

Frequency of Left Ventricular End-Diastolic Volume-Mediated Declines in Ejection Fraction in Patients Receiving Potentially Cardiotoxic Cancer Treatment

We sought to determine the frequency by which decreases in left ventricular (LV) end-diastolic volume (LVEDV) with and without increases in end-systolic volume (LVESV) influenced early cancer treatment-associated declines in LV ejection fraction (LVEF) or LV mass. One hundred twelve consecutively recruited subjects (aged 52 ± 14 years) with cancer underwent blinded cardiovascular magnetic resonance measurements of LV volumes, mass, and LVEF before and 3 months after initiating potentially cardiotoxic chemotherapy (72% of participants received anthracyclines). Twenty-six participants developed important declines in LVEF of >10% or to values <50% at 3 months, in whom 19% versus 60%, respectively, experienced their decline in LVEF due to isolated declines in LVEDV versus an increase in LVESV; participants who dropped their LVEF due to decreases in LVEDV lost more LV mass than those who dropped their LVEF due to an increase in LVESV (p = 0.03). Nearly one fifth of subjects experience marked LVEF declines due to an isolated decline in LVEDV after initiating potentially cardiotoxic chemotherapy. Because reductions in intravascular volume (which could be treated by volume repletion) may account for LVEDV-related declines in LVEF, these data indicate that LV volumes should be reviewed along with LVEF when acquiring imaging studies for cardiotoxicity during the treatment for cancer.

Targeting RING domains of Mdm2-MdmX E3 complex activates apoptotic arm of the p53 pathway in leukemia/lymphoma cells

Reactivation of tumor-suppressor p53 for targeted cancer therapy is an attractive strategy for cancers bearing wild-type (WT) p53. Targeting the Mdm2–p53 interface or MdmX ((MDM4), mouse double minute 4)–p53 interface or both has been a focus in the field. However, targeting the E3 ligase activity of Mdm2–MdmX really interesting new gene (RING)–RING interaction as a novel anticancer strategy has never been explored. In this report, we describe the identification and characterization of small molecule inhibitors targeting Mdm2–MdmX RING–RING interaction as a new class of E3 ligase inhibitors. With a fluorescence resonance energy transfer-based E3 activity assay in high-throughput screening of a chemical library, we identified inhibitors (designated as MMRis (Mdm2–MdmX RING domain inhibitors)) that specifically inhibit Mdm2–MdmX E3 ligase activity toward Mdm2 and p53 substrates. MMRi6 and its analog MMRi64 are capable of disrupting Mdm2–MdmX interactions in vitro and activating p53 in cells. In leukemia cells, MMRi64 potently induces downregulation of Mdm2 and MdmX. In contrast to Nutlin3a, MMRi64 only induces the expression of pro-apoptotic gene PUMA (p53 upregulated modulator of apoptosis) with minimal induction of growth-arresting gene p21. Consequently, MMRi64 selectively induces the apoptotic arm of the p53 pathway in leukemia/lymphoma cells. Owing to the distinct mechanisms of action of MMRi64 and Nutlin3a, their combination synergistically induces p53 and apoptosis. Taken together, this study reveals that Mdm2–MdmX has a critical role in apoptotic response of the p53 pathway and MMRi64 may serve as a new pharmacological tool for p53 studies and a platform for cancer drug development.

Mitochondrial protection impairs BET bromodomain inhibitor-mediated cell death and provides rationale for combination therapeutic strategies

Inhibitors of the bromodomain and extraterminal domain family (BETI) have recently entered phase I clinical trials. In patients with advanced leukemia's, potent antileukemia activity was displayed with minimum dose-limiting toxicity. In preclinical models of hematological malignancies, including aggressive B-cell lymphomas, BETI induced cell-cycle arrest and apoptosis. However, the underlying cell death mechanisms are still not well understood. Dissecting the mechanisms required by BETI to mediate cell death would provide strong direction on how to best utilize BETI to treat patients with aggressive hematological malignancies. Herein, we provide understanding of the molecular mechanisms underlying BETI-mediated cell death using I-BET762. Induction of cell death occurred in primary murine and human B-cell lymphomas through apoptosis. Genetic dissection using Eμ-myc B-cell lymphoma compound mutants demonstrated that I-BET762-induced apoptosis does not require the p53 pathway. Furthermore, deletion of Apaf1, and thus the absence of a functional apoptosome, is associated with a delayed drug response but do not provide long-term resistance. Prolonged treatment of this model in fact fails to suppress the therapeutic efficacy of the drug and is associated with biochemical features of autophagy. However, lack of mitochondrial permeability completely inhibited I-BET762-mediated tumor cell death, indicating mitochondrial damage as key events for its activity. Combination of I-BET762 with BH3-only mimetics ABT-263 or obatoclax, restored sensitivity to I-BET762 lymphoma killing; however, success was determined by expression of Bcl-2 family antiapoptotic proteins. Our study provides critical insight for clinical decisions regarding the appropriate strategy for using BETI as a single agent or in combination to treat patients with aggressive B-cell lymphomas.

The impact of life tables adjusted for smoking on the socio-economic difference in net survival for laryngeal and lung cancer

BACKGROUND

Net survival is a key measure in cancer control, but estimates for cancers that are strongly associated with smoking may be biased. General population life tables represent background mortality in net survival, but may not adequately reflect the higher mortality experienced by smokers.

METHODS

Life tables adjusted for smoking were developed, and their impact on net survival and inequalities in net survival for laryngeal and lung cancers was examined.

RESULTS

The 5-year net survival estimated with smoking-adjusted life tables was consistently higher than the survival estimated with unadjusted life tables: 7% higher for laryngeal cancer and 1.5% higher for lung cancer. The impact of using smoking-adjusted life tables was more pronounced in affluent patients; the deprivation gap in 5-year net survival for laryngeal cancer widened by 3%, from 11% to 14%.

CONCLUSIONS

Using smoking-adjusted life tables to estimate net survival has only a small impact on the deprivation gap in survival, even when inequalities are substantial. Adjusting for the higher, smoking-related background mortality did increase the estimates of net survival for all deprivation groups, and may be more important when measuring the public health impact of differences or changes in survival, such as avoidable deaths or crude probabilities of death.

Simultaneous radiolabel, genetic tagging and proliferation assays to study the organ distribution and fate of metastatic cells

We compared the suitability of 3 techniques to study tumor cell survival in the lungs of mice and proliferation into metastases. Genetic tagging of tumor cells with the bacterial beta-galactosidase marker gene lacZ, radiolabeling of tumor cells with [I-125]IdUrd, and S-phase labeling of cells with bromodeoxyuridine (BrdUrd) were used simultaneously to track the fate of highly metastatic K-1735 X-21 melanoma cells injected into syngeneic C3H/HeN mice. The melanoma cells were transfected with a plasmid containing lacZ and neomycin resistance genes. After growth in selective medium, the cells were incubated in medium containing [I-125]IdUrd and then injected i.v. into mice. Lungs isolated at various times after i.v. injection were processed for staining with X-gal, radioactive monitoring, and immunohistochemical staining with a monoclonal antibody against BrdUrd. At early time points, the presence of lacZ-positive cells directly correlated with radioactivity associated with viable cells. However, the expression of the beta-galactosidase was only stable for 1 week, and by 3 weeks after injection, large metastases contained only a few lacZ-positive cells. The combination of lacZ tagging with BrdUrd proliferation assay accurately identified dividing tumor cells in micrometastases. The simultaneous use of these 3 techniques allowed us to conclude that quantitative analysis of tumor cell survival is best accomplished by radioactive labeling of cells, whereas the use of lacZ-tagged cells allowed for studies of localization. Analysis of tumor cell proliferation requires the use of both lacZ tagging and immunohistochemistry using anti-BrdUrd antibodies. Since the process of metastasis consists of a series of distinct steps, each technique presents its own advantages and limitations.

Regulation of genes associated with angiogenesis, growth, and metastasis by specific p53 point mutations in a murine melanoma cell line

K1735 murine melanoma cells transfected with p53 cDNAs bearing specific point mutations are metastatic in nude mice, whereas the parent and control-transfected cells are nonmetastatic. To determine whether p53 gene mutations regulate genes associated with angiogenesis, growth, and metastasis, we examined expression of vascular endothelial growth factor I, IGF-I receptor, epidermal growth factor insulin-like growth factor I, IGF-I receptor, epidermal growth factor receptor, c-MET, and thrombospondin 1 in K1735 cells transfected with one of four different mutant p53 cDNAs. Northern blot analysis demonstrated differential upregulation of these genes in cells transfected with different mutant p53 cDNAs. Up-regulation of angiogenesis-, growth-, and metastasis-related genes by mutant p53 may contribute to metastasis formation.

Clinical educators' views on the quality of undergraduate clinical restorative dentistry in the UK and ROI

INTRODUCTION

Following concerns expressed regarding recently expanded dental education, a survey was conducted on United Kingdom and Republic of Ireland clinical educators' perceptions of their work and the educational experiences they provide in clinical restorative dentistry. Many of the challenges facing dental education are common to all countries, and it would be of interest to note if the views reported are representative of the greater European perspective. The results of this survey represent a European regional picture.

METHODS AND MATERIALS

This is a survey of clinical staff in restorative dentistry departments across all of the fully established UK and ROI dental schools. The survey covered factors affecting the quality of undergraduate learning in restorative dentistry and the implications of these for programme delivery. Thematic analysis was applied to qualitative responses.

RESULTS

One hundred and eighty-eight responses were received across the gamut of clinical educators' roles and across 15 of the 16 schools. Themes identified were personal workload, teaching effectiveness, students' clinical experiences, provision of teaching, departmental organisation and job satisfaction.

DISCUSSION

The survey findings had many parallels with other recent reports but also suggested some developments.

CONCLUSION

The survey provided an accurate snapshot of staff views on the quality of undergraduate clinical training in restorative dentistry. Despite experiencing difficulties in many areas of their work resulting in poor morale, staff considered teaching rewarding although undervalued by others. A number of recommendations are made for the development of undergraduate teaching.