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Abstract The DNA damage response (DDR) protein DNA Polymerase θ (Polθ) is synthetic lethal with homologous recombination (HR) factors and is therefore a promising drug target in BRCA1/2 mutant cancers. We discover an allosteric Polθ inhibitor (Polθi) class with 4–6 nM IC50 that selectively kills HR-deficient cells and acts synergistically with PARP inhibitors (PARPi) in multiple genetic backgrounds. X-ray crystallography and biochemistry reveal that Polθi selectively inhibits Polθ polymerase (Polθ-pol) in the closed conformation on B-form DNA/DNA via an induced fit mechanism. In contrast, Polθi fails to inhibit Polθ-pol catalytic activity on A-form DNA/RNA in which the enzyme binds in the open configuration. Remarkably, Polθi binding to the Polθ-pol:DNA/DNA closed complex traps the polymerase on DNA for more than forty minutes which elucidates the inhibitory mechanism of action. These data reveal a unique small-molecule DNA polymerase:DNA trapping mechanism that induces synthetic lethality in HR-deficient cells and potentiates the activity of PARPi.

Introduction Most solid organ transplants originate from donors meeting criteria for death by neurological criteria (DNC). Within the organ donor, physiological responses to brain death increase the risk of ischaemia reperfusion injury and delayed graft function. Donor preconditioning with calcineurin inhibition may reduce this risk.Methods and analysis We designed a multicentre placebo-controlled pilot randomised trial involving nine organ donation hospitals and all 28 transplant programmes in the Canadian provinces of Ontario and Québec. We planned to enrol 90 DNC donors and their approximately 324 organ recipients, totalling 414 participants. Donors receive an intravenous infusion of either tacrolimus 0.02 mg/kg over 4 hours prior to organ retrieval, or a matching placebo, while monitored in an intensive care unit for any haemodynamic changes during the infusion. Among all study organ recipients, we record measures of graft function for the first 7 days in hospital and we will record graft survival after 1 year. We examine the feasibility of this trial with respect to the proportion of all eligible donors enrolled and the proportion of all eligible transplant recipients consenting to receive a CINERGY organ transplant and to allow the use of their health data for study purposes. We will report these feasibility outcomes as proportions with 95% CIs. We also record any barriers encountered in the launch and in the implementation of this trial with detailed source documentation.Ethics and dissemination We will disseminate trial results through publications and presentations at participating sites and conferences. This study has been approved by Health Canada (HC6-24-c241083) and by the Research Ethics Boards of all participating sites and in Québec (MP-31-2020-3348) and Clinical Trials Ontario (Project #3309).Trial registration number NCT05148715.

Abstract Background Inhibition of cyclin-dependent kinase 9 (CDK9), a novel epigenetic target in cancer, can reactivate epigenetically silenced genes in cancer by dephosphorylating the SWI/SNF chromatin remodeler BRG1. Here, we characterized the anti-tumor efficacy of MC180295, a newly developed CDK9 inhibitor. Methods In this study, we explored the pharmacokinetics of MC180295 in mice and rats, and tested the anti-tumor efficacy of MC180295, and its enantiomers, in multiple cancer cell lines and mouse models. We also combined CDK9 inhibition with a DNA methyltransferase (DNMT) inhibitor, decitabine, in multiple mouse models, and tested MC180295 dependence on T cells. Drug toxicity was measured by checking body weights and complete blood counts. Results MC180295 had high specificity for CDK9 and high potency against multiple neoplastic cell lines (median IC50 of 171 nM in 46 cell lines representing 6 different malignancies), with the highest potency seen in AML cell lines derived from patients with MLL translocations. MC180295 is a racemic mixture of two enantiomers, MC180379 and MC180380, with MC180380 showing higher potency in a live-cell epigenetic assay. Both MC180295 and MC180380 showed efficacy in in vivo AML and colon cancer xenograft models, and significant synergy with decitabine in both cancer models. Lastly, we found that CDK9 inhibition-mediated anti-tumoral effects were partially dependent on CD8 + T cells in vivo, indicating a significant immune component to the response. Conclusions MC180380, an inhibitor of cyclin-dependent kinase 9 (CDK9), is an efficacious anti-cancer agent worth advancing further toward clinical use.

Introduction: In toxicology, steps are being taken towards more mechanism-focused and human relevant approaches to risk assessment, requiring new approaches and methods. Additionally, there is increasing emphasis by regulators on risk assessment of immunotoxicity.Methods: Here we present data from a peripheral blood mononuclear cell (PBMC) system whereby a varied set of stimuli, including those against the TCR and Toll-like receptors, enable readouts of cytokine and prostaglandin E2 (PGE2) production with monocyte, T cell and B cell viability, proliferation, and associated activation markers. In addition to results on the impact of the stimuli used, initial profiling data for a case study chemical, curcumin, is presented, illustrating how the system can be used to generate information on the impact of exogenous materials on three major constituent immune cell subsets for use in risk assessment and to direct follow-on studies.Results: The different stimuli drove distinct responses, not only in relation to the “quantity” of the response but also the “quality”. Curcumin had a limited impact on the B cell parameters measured, with the stimuli used, and it was noted that in contrast to T cells where there was either no impact or a reduction in viability and proliferation with increasing concentration, for B cells there was a small but significant increase in both measurements at curcumin concentrations below 20 µM. Similarly, whilst expression of activation markers by T cells was reduced by the highest concentration of curcumin, they were increased in B cells. Curcumin only impacted the viability of stimulated monocytes at the highest concentration and had differential impact on different activation markers. Levels of all cytokines and PGE2 were reduced at higher concentrations.Discussion: Although the platform has certain limitations, it nevertheless enables assessment of healthy baseline monocyte, T-, and B-cell responses, and scrutiny of the impact of different stimuli to detect potential immune suppression or enhancement from exogenous materials. In the case of curcumin, a pattern of responses indicative of immune suppressive / anti-inflammatory effects was detected. It is an accessible, highly modifiable system that can be used to screen materials and guide further studies, providing a holistic, integrated picture of effects.

Background Critically ill patients are at high risk of acquiring ventilator-associated pneumonia (VAP), which occurs in approximately 20% of mechanically ventilated patients. VAP results either from aspiration of pathogen-contaminated oropharyngeal secretions or contaminated biofilms that form on endotracheal tubes (ETTs) after intubation. VAP results in increased duration of mechanical ventilation, increased intensive care unit and hospital length of stay, increased risk of death and increased healthcare costs. Because of its impact on patient outcomes and the healthcare system, VAP is regarded as an important patient safety issue and there is an urgent need for better evidence on the efficacy of prevention strategies. Modified ETTs that reduce aspiration of oropharyngeal secretions with subglottic secretion drainage or reduce the occurrence of biofilm with a coating of ceragenins (CSAs) are available for clinical use in Canada. In this implementation study, we will evaluate the efficacy of these two types of Health Canada-licensed ETTs on the occurrence of VAP, and impact on patient-centred outcomes.Methods In this ongoing, pragmatic, prospective, longitudinal, interrupted time, cross-over implementation study, we will compare the efficacy of a CSA-coated ETT (CeraShield N8 Pharma) with an ETT with subglottic secretion drainage (Taper Guard, Covidien). The study periods consist of four alternating time periods of 11 or 12 weeks or a total of 23 weeks for each ETT. All patients intubated with the study ETT in each time period will be included in an intention-to-treat analysis. Outcomes will include VAP incidence, mortality and health services utilisation including antibiotic use and length of stay.Ethics and dissemination This study has been approved by the Health Sciences Research Ethics Board at Queen’s University. The results of this study will be actively disseminated through manuscript publication and conference presentations.Trial registration number NCT05761613.

IntroductionThe engagement of the SARS-CoV-2 spike protein with ACE2 is a critical step for viral entry to human cells, and, therefore, blocking this interaction is a major determinant of the efficacy of monoclonal antibody therapeutics and vaccine elicited serum antibodies. The emergence of SARS-CoV-2 variants has necessitated the development of adaptable assays that can be applied to assess the effectiveness of antibody-based therapeutics.MethodsThrough the testing of a range of recombinant spike proteins, we have developed a cell-based, ACE2/spike protein interaction assay that characterises monoclonal anti-spike protein antibodies and neutralising antibodies in donor serum. The assay uses high-content imaging to quantify cell-bound spike protein fluorescence.ResultsUsing spike proteins from the original “Wuhan” SARS-CoV-2 strain and the Delta and Omicron variants, we identified differential blocking activity of three monoclonal antibodies directed against the spike receptor-binding domain. Importantly, biological activity in the spike interaction assay translated to efficacy in a SARS-CoV-2 infection assay.DiscussionThe spike protein interaction assay can be used to monitor anti-spike antibodies against the major known SARS-CoV-2 variants and is readily adaptable for quantification of the impact of antibodies against new and emerging SARS-CoV-2 variants.

Background: Crohn’s and Ulcerative Colitis Questionnaire-32 (CUCQ-32) is a validated questionnaire to measure the quality of life (QoL) in Inflammatory Bowel Disease (IBD). However, it does not have stoma-specific questions and can be lengthy. This study aimed to validate a subset of the CUCQ-32 that would be suitable for patients with a stoma. Methods: Baseline data were collected from a cohort of patients with acute ulcerative colitis who were participating in the CONSTRUCT multicentre clinical trial. A subset of the CUCQ-32 questions was selected by stepwise regression. Further validation was examined using data from the UK IBD biological therapies audit. Construct validity was carried out using the EuroQol 5 dimensions (EQ5D) questionnaire, Simple Clinical Colitis Activity Index (SCCAI), and the Harvey–Bradshaw Index (HBI). Results: Using the data from 124 patients, a short-version questionnaire (CUCQ-12) was developed. Data from 484 patients with IBD (382 patients with Crohn’s disease, 76 patients with ulcerative colitis, and 26 patients with IBD-Unclassified) and 61 patients with stoma provided further validation of the CUCQ-12. A literature review and an expert focus group identified supplementary stoma-specific questions for the CUCQ-12+. The CUCQ-12+ demonstrated excellent internal consistency (Cronbach’s α = 0.86); established effective reproducibility (intra-class correlation coefficient = 0.74); correlated well with the EQ5D (r= −0.48), HBI (r = 0.45), and SCCAI (r = 0.43); and represented good responsiveness statistics (>0.5). Conclusions: CUCQ-12+ is a valid and reliable QoL measure used for all patients with IBD in clinical practice, including patients with a stoma.

Introduction In donation after circulatory determination of death, death is declared 5 min after circulatory arrest. This practice assumes, but does not explicitly confirm, permanent loss of brain activity. While this assumption is rooted a strong physiological rationale, paucity of direct human data regarding temporal relationship between cessation of brain activity and circulatory arrest during the dying process threatens public and healthcare provider trust in deceased organ donation.Methods and analysis In this cohort study, we will prospectively record cerebral and brainstem electrical activity, cerebral blood flow velocity and arterial blood pressure using electroencephalography (EEG), brainstem evoked potentials, transcranial doppler and bedside haemodynamic monitors in adult patients undergoing planned withdrawal of life sustaining measures in the intensive care units at five hospital sites for 18 months. We will use MATLAB to synchronise waveform data and compute the time of cessation of each signal relative to circulatory arrest. Our primary outcome is the feasibility of patient accrual, while secondary outcomes are (a) proportion of patients with complete waveform recordings and data transfer to coordinating site and (b) time difference between cessation of neurophysiological signals and circulatory arrest. We expect to accrue 1 patient/site/month for a total of 90 patients.Ethics and dissemination We have ethics approval from Clinical Trials Ontario (protocol #3862, version 1.0, date 19 January 2022.) and the relevant Research Ethics Board for each site. We will obtain written informed consent from legal substitute decision makers. We will present study results at research conferences including donor family partner forum and in peer-reviewed publications.Trial registration number NCT05306327.

Introduction Traumatic brain injury (TBI) is the leading cause of mortality and long-term disability in young adults. Despite the high prevalence of anaemia and red blood cell transfusion in patients with TBI, the optimal haemoglobin (Hb) transfusion threshold is unknown. We undertook a randomised trial to evaluate whether a liberal transfusion strategy improves clinical outcomes compared with a restrictive strategy.Methods and analysis HEMOglobin Transfusion Threshold in Traumatic Brain Injury OptimizatiON is an international pragmatic randomised open label blinded-endpoint clinical trial. We will include 742 adult patients admitted to an intensive care unit (ICU) with an acute moderate or severe blunt TBI (Glasgow Coma Scale ≤12) and a Hb level ≤100 g/L. Patients are randomly allocated using a 1:1 ratio, stratified by site, to a liberal (triggered by Hb ≤100 g/L) or a restrictive (triggered by Hb ≤70 g/L) transfusion strategy applied from the time of randomisation to the decision to withdraw life-sustaining therapies, ICU discharge or death. Primary and secondary outcomes are assessed centrally by trained research personnel blinded to the intervention. The primary outcome is the Glasgow Outcome Scale extended at 6 months. Secondary outcomes include overall functional independence measure, overall quality of life (EuroQoL 5-Dimension 5-Level; EQ-5D-5L), TBI-specific quality of life (Quality of Life after Brain Injury; QOLIBRI), depression (Patient Health Questionnaire; PHQ-9) and mortality.Ethics and dissemination This trial is approved by the CHU de Québec—Université Laval research ethics board (MP-20-2018-3706) and ethic boards at all participating sites. Our results will be published and shared with relevant organisations and healthcare professionals.Trial registration number NCT03260478.

With the rising prevalence of obesity, non-alcoholic fatty liver disease (NAFLD) now affects 20–25% of the global population. NAFLD, a progressive condition associated with oxidative stress, can result in cirrhosis and liver cancer in 10% and 3% of patients suffering NAFLD, respectively. Therapeutic options are currently limited, emphasizing the need for novel treatments. In this study, we examined the potential of activating the transcription factor NRF2, a crucial player in combating oxidative stress, as an innovative approach to treating NAFLD. Utilizing a CRISPR/Cas9-engineered human HEK293T cell line, we were able to monitor the expression of heme oxygenase-1 (HMOX1), an NRF2 target, using a Nanoluc luciferase tag. Our model was validated using a known NRF2 activator, after which we screened 1200 FDA-approved drugs, unearthing six compounds (Disulfiram, Thiostrepton, Auranofin, Thimerosal, Halofantrine, and Vorinostat) that enhanced NRF2 activity and antioxidant response. These compounds demonstrated protective effects against oxidative stress induced by hydrogen peroxide and lipid droplets accumulation in vitro with hepatoma HUH-7 cells. Our study underscores the utility of CRISPR/Cas9 tagging with Nanoluc luciferase in identifying potential NRF2 activators, paving the way for potential NAFLD therapeutics.

Abstract Blockade of PD-1/PD-L1 interactions is proving an exciting, durable therapeutic modality in a range of cancers whereby T cells are released from checkpoint inhibition to revive their inherent anti-tumour activity. Here we have studied various ways to model ex vivo T cell function in order to compare the impact of the clinically utilised anti-PD-1 antibody, pembrolizumab (Keytruda) on the activation of human T cells: focussing on the release of pro-inflammatory IFNγ and anti-inflammatory IL-10 to assess functionality. Firstly, we investigated the actions of pembrolizumab in an acute model of T-cell activation with either immature or mature allogeneic dendritic cells (DCs); pembrolizumab enhanced IFNγ and IL-10 release from purified CD4+ T-cells in the majority of donors with a bias towards pro-inflammatory cytokine release. Next, we modelled the impact of pembrolizumab in settings of more chronic T-cell activation. In a 7-day antigen-specific response to EBV peptides, the presence of pembrolizumab resulted in a relatively modest increase in both IFNγ and IL-10 release. Where pembrolizumab was assessed against long-term stimulated CD4+ cells that had up-regulated the exhaustion markers TIM-3 and PD-1, there was a highly effective enhancement of the otherwise exhausted response to allogeneic DCs with respect to IFNγ production. By contrast, the restoration of IL-10 production was considerably more limited. Finally, to assess a direct clinical relevance we investigated the consequence of PD-1/PD-L1 blockade in the disease setting of dissociated cells from lung and colon carcinomas responding to allogeneic DCs: here, pembrolizumab once more enhanced IFNγ production from the majority of tumour preparations whereas, again, the increase in IL-10 release was modest at best. In conclusion, we have shown that the contribution of PD-1—revealed by using a canonical blocking antibody to interrupt its interaction with PD-L1—to the production of an exemplar pro- and anti-inflammatory cytokine, respectively, depends in magnitude and ratio on the particular stimulation setting and activation status of the target T cell. We have identified a number of in vitro assays with response profiles that mimic features of dissociated cell populations from primary tumours thereby indicating these represent disease-relevant functional assays for the screening of immune checkpoint inhibitors in current and future development. Such in vitro assays may also support patient stratification of those likely to respond to immuno-oncology therapies in the wider population.

The development of second-entry topical products is hampered by several factors. The excipient composition should be similar to the reference product because excipients may also contribute to efficacy. Conventional pharmacokinetic bioequivalence studies were not considered acceptable because drug concentrations are measured downstream after the site of action. There was no agreed methodology to characterize the microstructure of semisolids, and waivers of therapeutic equivalence studies with clinical endpoints were not possible. Only the vasoconstrictor assay for corticosteroids was accepted as a surrogate. This paper describes the implementation of the European Union’s stepwise approach for locally acting products to cutaneous products, discusses the equivalence requirements of the EMA Draft Guideline on the Quality and Equivalence of Topical Products, and compares them with the US Food and Drug Administration recommendations. Step 1 includes the possibility of waivers for simple formulations based on in vitro data only (Q1 + Q2 + Q3 + IVRT). Step 2 includes step 1 requirements plus a kinetic study (TS/IVPT/PKBE) to compare the local availability of complex formulations. Step 3 refers to clinical studies with pharmacodynamic/clinical endpoints. As excipients may affect the local tolerability and efficacy of the products, the similarity of excipient composition is required in all steps, except where clinical endpoints are compared.

Tubulin is a protein that plays a critical role in maintaining cellular structure and facilitating cell division. Inhibiting tubulin polymerization has been shown to be an effective strategy for inhibiting the proliferation of cancer cells. In the past, identifying compounds that could inhibit tubulin polymerization has required the use of in vitro assays utilizing purified tubulin or immunofluorescence of fixed cells. This study presents a novel approach for identifying tubulin polymerization inhibitors using a CRISPR-edited cell line that expresses fluorescently tagged β-tubulin and a nuclear protein, enabling the visualization of tubulin polymerization dynamics via high-content imaging analysis (HCI). The cells were treated with known tubulin polymerization inhibitors, colchicine, and vincristine, and the resulting phenotypic changes indicative of tubulin polymerization inhibition were confirmed using HCI. Furthermore, a library of 429 kinase inhibitors was screened, resulting in the identification of three compounds (ON-01910, HMN-214, and KX2-391) that inhibit tubulin polymerization. Live cell tracking analysis confirmed that compound treatment leads to rapid tubulin depolymerization. These findings suggest that CRISPR-edited cells with fluorescently tagged endogenous β-tubulin can be utilized to screen large compound libraries containing diverse chemical families for the identification of novel tubulin polymerization inhibitors.

Introduction Initiation of acute kidney replacement therapy (KRT) is common in critically ill adults admitted to the intensive care unit (ICU), and associated with increased morbidity and mortality. KRT has been linked to poor neurocognitive outcomes, leading to reduced quality of life and increased utilisation of healthcare resources. Adults on dialysis in the ICU may be particularly at risk of neurocognitive impairment, as survivors of critical illness are already predisposed to developing cerebrovascular disease and cognitive dysfunction long-term relative to healthy controls. Regional cerebral oxygen saturation may provide a critical early marker of long-term neurocognitive impairment in this population. This study aims to understand cerebral oxygenation in patients undergoing KRT (continuous or intermittent) in the ICU. These findings will be correlated with long-term cognitive and functional outcomes, and structural brain pathology.Methods and analysis 108 patients scheduled to undergo treatment for acute kidney injury with KRT in the Kingston Health Sciences Centre ICU will be recruited into this prospective observational study. Enrolled patients will be assessed with intradialytic cerebral oximetry using near infrared spectroscopy. Delirium will be assessed daily with the Confusion Assessment Method-ICU (CAM-ICU) and severity quantified as cumulative CAM-ICU-7 scores. Neurocognitive impairment will be assessed at 3 and 12 months after hospital discharge using the Kinarm and Repeatable Battery for the Assessment of Neuropsychological Status. Structural brain pathology on MRI will also be measured at the same timepoints. Driving safety, adverse events and medication adherence will be assessed at 12 months to evaluate the impact of neurocognitive impairment on functional outcomes.Ethics and dissemination This study is approved by the Queen’s University Health Sciences/Affiliated Teaching Hospitals Research Ethics Board (DMED-2424-20). Results will be presented at critical care conferences, and a lay summary will be provided to patients in their preferred format.Trial registration number NCT04722939

Background: Patients on hemodialysis (HD) are known to exhibit low values of regional cerebral oxygenation (rSO2) and impaired cognitive functioning. The etiology of both is currently unknown. Objective: To determine the feasibility of serially monitoring rSO2 in patients initiating HD. In addition, we sought to investigate how rSO2 is related to hemodynamic and dialysis parameters. Design: Prospective observational study. Setting: Single-center tertiary academic teaching hospital in Ontario, Canada. Participants: Six patients initiating HD were enrolled in the study. Methods: Feasibility was defined as successful study enrollment (>1 patient/month), successful consent rate (>70%), high data capture rates (>90%), and assessment tolerability. Regional cerebral oxygenation monitoring was performed 1 time/wk for the first year of dialysis. A neuropsychological battery was performed 3 times during the study: before dialysis initiation, 3 months, and 1 year after dialysis initiation. The neuropsychological battery included a traditional screening tool: the Repeatable Battery for the Assessment of Neuropsychological Status, and a robot-based assessment: Kinarm. Results: Our overall consent rate was 33%, and our enrollment rate was 0.4 patients/mo. In total 243 rSO2 sessions were recorded, with a data capture rate of 91.4% (222/243) across the 6 patients. Throughout the study, no adverse interactions were reported. Correlations between rSO2 with hemodynamic and dialysis parameters showed individual patient variability. However, at the individual level, all patients demonstrated positive correlations between mean arterial pressure and rSO2. Patients who had more than 3 liters of fluid showed significant negative correlations with rSO2. Less cognitive impairment was detected after initiating dialysis. Limitation: This small cohort limits conclusions that can be made between rSO2 and hemodynamic and dialysis parameters. Conclusions: Prospectively monitoring rSO2 in patients was unfeasible in a single dialysis unit, due to low consent and enrollment rates. However, rSO2 monitoring may provide unique insights into the effects of HD on cerebral oxygenation that should be further investigated. Trial Registration: Due to the feasibility nature of this study, no trial registration was performed.

The Electrophilic Allergen Screening Assay (EASA) has emerged as a promising in chemico method to detect the first key event in the adverse outcome pathway (AOP) for skin sensitization. This assay functions by assessing the depletion of one of two probe molecules (4-nitrobenzenethiol (NBT) and pyridoxylamine (PDA)) in the presence of a test compound (TC). The initial development of EASA utilized a cuvette format resulting in multiple measurement challenges such as low throughput and the inability to include adequate control measurements. In this study, we describe the redesign of EASA into a 96-well plate format that incorporates in-process control measurements to quantify key sources of variability each time the assay is run. The data from the analysis of 67 TCs using the 96-well format had 77% concordance with animal data from the local lymph node assay (LLNA), a result consistent with that for the direct peptide reactivity assay (DPRA), an OECD test guideline (442C) protein binding assay. Overall, the measurement science approach described here provides steps during assay development that can be taken to increase confidence of in chemico assays by attempting to fully characterize the sources of variability and potential biases and incorporate in-process control measurements into the assay.

The cellular uptake, intracellular processing, and presentation of foreign antigen are crucial processes for eliciting an effective adaptive host response to the majority of pathogens. The effective recognition of antigen by T cells requires that it is first processed and then presented on MHC molecules that are expressed on other cells. A critical step leading to the presentation of antigen is delivering the foreign cargo to an intracellular compartment where the antigen can be processed and loaded onto MHC molecules. Fc-gamma receptors (FcγRs) recognize IgG-coated targets, such as opsonized pathogens or immune complexes (ICs). Cross-linking leads to internalization of the cargo with associated activation of down-stream signaling cascades. FcγRs vary in their affinity for IgG and intracellular trafficking, and therefore have an opportunity to regulate antigen presentation by controlling the shuttling and processing of their cargos. In this way, they critically influence physiological and pathophysiological adaptive immune cell functions. In this review, we will cover the contribution of FcγRs to antigen-presentation with a focus on the intracellular trafficking of IgG-ICs and the pathways that support this function. We will also discuss genetic evidence linking FcγR biology to immune cell activation and autoimmune processes as exemplified by systemic lupus erythematosus (SLE).

Proton exchange membrane fuel cells (PEMFCs) using porous metallic foam flow-field plates have been demonstrated as an alternative to conventional rib and channel designs, showing high performance at high currents. However, the transport of liquid product water through metal foam flow-field plates in PEMFC conditions is not well understood, especially at the individual pore level. In this work, ex-situ experiments are conducted to visualise liquid water movement within a metal foam flow-field plate, considering hydrophobicity, foam pore size and air flow rate. A two-phase numerical model is then developed to further investigate the fundamental water transport behaviour in porous metal foam flow-field plates. Both the experimental and numerical work demonstrate that unlike conventional PEMFC channels, air flow rate does not have a strong influence on water removal due to the high surface tensions between the water and foam pore ligaments. A hydrophobic foam was seen to transport liquid water away from the initial injection point faster than a hydrophilic foam. In ex-situ tests, liquid water forms and maintains a random preferential pathway until the flow-field edge is reached. These results suggest that controlled foam hydrophobicity and pore size is the best way of managing water distribution in PEMFCs with porous flow-field plates.

Traditionally, visually-guided patch clamp in brain slices using submerged recording conditions has been required to characterise the activity of individual neurons. However, due to limited oxygen availability, submerged conditions truncate fast network oscillations including epileptiform activity. Thus it is technically challenging to study the contribution of individual identified neurons to fast network activity. The membrane chamber is a submerged-style recording chamber, modified to enhance oxygen supply to the slice, which we use to demonstrate the ability to record single-cell activity during in vitro epilepsy. We elicited epileptiform activity using 9 mM potassium and simultaneously recorded from fluorescently labelled interneurons. Epileptiform discharges were more reliable than in standard submerged conditions. During these synchronous discharges interneuron firing frequency increased and action potential amplitude progressively decreased. The firing of fifteen interneurons was significantly correlated with epileptiform high frequency activity (HFA; ~100-500 Hz) cycles. We also recorded epileptiform activity in tissue prepared from chronically epileptic rats, treated with intrahippocampal tetanus neurotoxin. Four of these slices generated fast ripple activity, unique to chronic epilepsy. We showed the membrane chamber is a promising new in vitro environment facilitating patch clamp recordings in acute epilepsy models. Further, we showed that chronic epilepsy can be better modelled using ex vivo brain slices. These findings demonstrate that the membrane chamber facilitates previously challenging investigations into the neuronal correlates of epileptiform activity in vitro.

The death of C. Richard Conti, MD, MACC in February 2022 marked the passing of a global leader in cardiology who played a pivotal role in the history of the American College of Cardiology and the College's outreach to the People's Republic of China.

Many researchers have found that a woman is less likely to be a victim of domestic violence if she is more educated. But some studies found that a few years in school had little or no effect on a woman’s risk of being hit by her husband. This paper studies domestic violence against women in 29 countries, using ‘Demographic and Health Survey’ household data, and data from ‘Work, Attitudes & Spending’ surveys in Nigeria. In most countries studied in this paper, there is clear evidence that education reduces the risk of violence; but education appears to have much less effect on risk of violence in three countries (Cameroon, Liberia, and Nigeria). Nigeria is used as a case study, to examine these issues in depth. This paper finds evidence that the apparent lack of effect of education is an artefact of the data, which can be explained by studying different ethnic groups separately. It is not obvious why these ethnic groups differ; but female seclusion and nomadic cattle farming may explain much of the apparent difference in GBV prevalence rates between ethnic groups.

Recent evidence indicates that CXCR2 signaling is crucial for cancer progression, and its antagonist SB225002 induces apoptosis in Wilms' tumor cells. Here, we investigated the effect of SB225002 on cell cycle progression and apoptosis induction in vitro, using CDDP-sensitive and -resistant OVCA cell lines with different p53 status (wild type, mutant or null). Adenovirus infection of wild-type p53 or transfection of p53 siRNA was used to over-express or knock-down p53. Cell cycle and apoptosis were determined by flow cytometry or Hoechst staining and observation of nuclear morphology. Our data demonstrated that SB225002 induced apoptosis in both wild-type and p53-deficient ovarian cancer (OVCA) cells through alternative mechanisms. SB225002 promoted mitotic catastrophe, as evidenced by the accumulation of mitotic cells with spindle abnormalities, chromosome mis-segregation, multi-polar cell division, multiple nuclei, aneuploidy/polyploidy and subsequent extensive apoptosis. SB225002-induced mitotic catastrophe appeared to be mediated by down-regulation of checkpoint kinase Chk1 and Cdk1-cyclin B activation. In cells expressing wild-type p53 (OV2008 and C13*), SB225002 increased total and phospho-Ser p53 levels, and p53 knock-down decreased SB225002-induced apoptosis, without affecting premature mitosis. These results suggest that SB225002 induces p53-dependent apoptosis, and provokes mitotic catastrophe in p53-independent manner in p53 wild-type cells. Reconstitution with wild-type P53 in P53-null SKOV3 cell attenuated SB225002-induced mitotic catastrophe, suggesting p53 prevented mitotic catastrophe induced by SB225002 in p53-deficient OVCA cells. Finally, the effect of SB225002 could not be prevented by pretreatment with CXCR2 ligand or its neutralizing antibody. The present studies demonstrate for the first time that SB225002 has dual actions in OVCA cells, inducing classic apoptosis through p53 activation and provoking mitotic catastrophe in both p53 wild-type and deficient cells by Chk1 inhibition and Cdk activation. These findings raise the possibility of SB225002 as a new candidate molecule for OVCA therapy independent of the p53 status.

Shared decision-making is appropriate for clinical decisions involving multiple reasonable options, which occur frequently in the cardiovascular care of older adults. The process includes the communication of relevant factual information between the patient and the clinician, elicitation of patient preferences, and a mutual agreement on the best course of action to meet the patient's personal goals. For older adults, there are common challenges and considerations with regard to shared decision-making, some of which (eg, cognitive impairment) may be biologically linked to cardiovascular disease. There are tools designed to facilitate the shared decision-making process, known as decision aids, which are broadly effective although have shortcomings when applied to older adults. Novel approaches in clinical research and health systems changes will go some way toward improving shared decision-making for older adults, but the greatest scope for improvement may be within the grass roots areas of communication skills, interdisciplinary teamwork, and simply asking our patients what matters most.

This study explored how the use of three different pedagogical frameworks (community science, storytelling, and inquiry-based learning) influenced learners' awareness and appreciation of flagellate plants in an undergraduate online botany course. Students' opinions, attitudes, and perceptions toward science were explored using the Classroom Undergraduate Research Experience survey. Qualitative and quantitative results indicated that although most students appreciated all three activities, the storytelling activity produced the most positive perceptions of learning. Logistic regression analyses demonstrated that gender and attitudes toward science influenced student perceptions of the activities. Positive science attitudes predicted positive perceptions of the activities, and female students were more likely to report positive perceptions. These results suggest that as a pedagogical framework for organizing learning activities, storytelling holds potential for promoting positive attitudes toward science and science learning, particularly with female learners.