42 research outputs found
Unexpected medical undergraduate simulation training (UMUST): can unexpected medical simulation scenarios help prepare medical students for the transition to foundation year doctor?
BACKGROUND: Preparing medical students with the skills necessary to deal with emergency situations as junior doctors can be challenging due to the complexities of creating authentic ‘real life’ experiences in artificial environments. The following paper is an evaluation of the UMUST (Unexpected Medical Undergraduate Simulation Training) project; a high-fidelity simulation based training programme designed to emulate the experience of dealing with medical emergencies for final year medical students preparing for practice as Foundation Year trainees. METHODS: Final year medical students from Liverpool University who undertake their clinical placements at Blackpool Teaching Hospitals NHS Foundation Trust and St. Helens & Knowsley Teaching Hospitals NHS Trust were randomly allocated into groups and took part in a series of four unexpected simulation based scenarios. At the beginning of the week in which the scenarios ran, participants were issued with a hospital bleep which they carried with them during their placement. At an unknown time to them, the participants were bleeped to attend a simulated emergency scenario, and on arrival to the Clinical Skills and Simulation facility, members of the education team undertook a standardised simulation scenario. Each session was recorded on video which the participants subsequently watched as part of a debriefing process. An assessment tool was developed to gauge whether the participants made progress in their learning over the course of the four sessions. Focus groups were held with the participants in order to evaluate their experience of the programme, and questionnaires were later distributed to all participants once they had begun working as a Foundation Year trainee. The questionnaires asked them how relevant UMUST was in preparing them for dealing with medical emergencies. RESULTS: The questionnaires and the focus groups clearly showed that the doctors felt like UMUST was very valuable in preparing them to work as junior doctors. They had enjoyed taking part in UMUST and thought was a realistic and useful part of their undergraduate training. CONCLUSIONS: The feedback from the focus groups and the subsequent questionnaires clearly demonstrate that participants felt the UMUST programme helped to prepare them as junior doctors in terms of dealing with emergency situations
Reduction in oxidatively generated DNA damage following smoking cessation
<p>Abstract</p> <p>Background</p> <p>Cigarette smoking is a known cause of cancer, and cancer may be in part due to effects of oxidative stress. However, whether smoking cessation reverses oxidatively induced DNA damage unclear. The current study sought to examine the extent to which three DNA lesions showed significant reductions after participants quit smoking.</p> <p>Methods</p> <p>Participants (n = 19) in this study were recruited from an ongoing 16-week smoking cessation clinical trial and provided blood samples from which leukocyte DNA was extracted and assessed for 3 DNA lesions (thymine glycol modification [d(T<sup>g</sup>pA)]; formamide breakdown of pyrimidine bases [d(T<sup>g</sup>pA)]; 8-oxo-7,8-dihydroguanine [d(G<sup>h</sup>)]) via liquid chromatography tandem mass spectrometry (LC-MS/MS). Change in lesions over time was assessed using generalized estimating equations, controlling for gender, age, and treatment condition.</p> <p>Results</p> <p>Overall time effects for the d(T<sup>g</sup>pA) (χ<sup>2</sup>(3) = 8.068, p < 0.045), d(P<sup>f</sup>pA) (χ<sup>2</sup>(3) = 8.477, p < 0.037), and d(G<sup>h</sup>) (χ<sup>2</sup>(3) = 37.599, p < 0.001) lesions were seen, indicating levels of each decreased significantly after CO-confirmed smoking cessation. The d(T<sup>g</sup>pA) and d(P<sup>f</sup>pA) lesions show relatively greater rebound at Week 16 compared to the d(G<sup>h</sup>) lesion (88% of baseline for d(T<sup>g</sup>pA), 64% of baseline for d(P<sup>f</sup>pA), vs 46% of baseline for d(G<sup>h</sup>)).</p> <p>Conclusions</p> <p>Overall, results from this analysis suggest that cigarette smoking contributes to oxidatively induced DNA damage, and that smoking cessation appears to reduce levels of specific damage markers between 30-50 percent in the short term. Future research may shed light on the broader array of oxidative damage influenced by smoking and over longer durations of abstinence, to provide further insights into mechanisms underlying carcinogenesis.</p
Preclinical Evaluation of Long-Acting Emtricitabine Semi-Solid Prodrug Nanoparticle Formulations.
Long-acting injectable (LAI) formulations promise to deliver patient benefits by overcoming issues associated with non-adherence. A preclinical assessment of semi-solid prodrug nanoparticle (SSPN) LAI formulations of emtricitabine (FTC) is reported here. Pharmacokinetics over 28 days were assessed in Wistar rats, New Zealand white rabbits, and Balb/C mice following intramuscular injection. Two lead formulations were assessed for the prevention of an HIV infection in NSG-cmah-/- humanised mice to ensure antiviral activities were as anticipated according to the pharmacokinetics. Cmax was reached by 12, 48, and 24 h in rats, rabbits, and mice, respectively. Plasma concentrations were below the limit of detection (2 ng/mL) by 21 days in rats and rabbits, and 28 days in mice. Mice treated with SSPN formulations demonstrated undetectable viral loads (700 copies/mL detection limit), and HIV RNA remained undetectable 28 days post-infection in plasma, spleen, lung, and liver. The in vivo data presented here demonstrate that the combined prodrug/SSPN approach can provide a dramatically extended pharmacokinetic half-life across multiple preclinical species. Species differences in renal clearance of FTC mean that longer exposures are likely to be achievable in humans than in preclinical models
A hierarchical Bayesian model for understanding the spatiotemporal dynamics of the intestinal epithelium
Our work addresses two key challenges, one biological and one methodological. First, we aim to understand how proliferation and cell migration rates in the intestinal epithelium are related under healthy, damaged (Ara-C treated) and recovering conditions, and how these relations can be used to identify mechanisms of repair and regeneration. We analyse new data, presented in more detail in a companion paper, in which BrdU/IdU cell-labelling experiments were performed under these respective conditions. Second, in considering how to more rigorously process these data and interpret them using mathematical models, we use a probabilistic, hierarchical approach. This provides a best-practice approach for systematically modelling and understanding the uncertainties that can otherwise undermine the generation of reliable conclusions-uncertainties in experimental measurement and treatment, difficult-to-compare mathematical models of underlying mechanisms, and unknown or unobserved parameters. Both spatially discrete and continuous mechanistic models are considered and related via hierarchical conditional probability assumptions. We perform model checks on both in-sample and out-of-sample datasets and use them to show how to test possible model improvements and assess the robustness of our conclusions. We conclude, for the present set of experiments, that a primarily proliferation-driven model suffices to predict labelled cell dynamics over most time-scales
Long-Term Impact of Malaria Chemoprophylaxis on Cognitive Abilities and Educational Attainment: Follow-Up of a Controlled Trial
OBJECTIVES: We investigated the long-term impact of early childhood malaria prophylaxis on cognitive and educational outcomes. DESIGN: This was a household-based cluster-controlled intervention trial. SETTING: The study was conducted in 15 villages situated between 32 km to the east and 22 km to the west of the town of Farafenni, the Gambia, on the north bank of the River Gambia. PARTICIPANTS: A total of 1,190 children aged 3–59 mo took part in the trial. We traced 579 trial participants (291 in the prophylaxis group and 288 in the placebo group) in 2001, when their median age was 17 y 1 mo (range 14 y 9 mo to 19 y 6 mo). INTERVENTIONS: Participants received malaria chemoprophylaxis (dapsone/pyrimethamine) or placebo for between one and three malaria transmission seasons from 1985 to 1987 during the controlled trial. At the end of the trial, prophylaxis was provided for all children under 5 y of age living in the study villages. OUTCOME MEASURES: The outcome measures were cognitive abilities, school enrolment, and educational attainment (highest grade reached at school). RESULTS: There was no significant overall intervention effect on cognitive abilities, but there was a significant interaction between intervention group and the duration of post-trial prophylaxis (p = 0.034), with cognitive ability somewhat higher in the intervention group among children who received no post-trial prophylaxis (treatment effect = 0.2 standard deviations [SD], 95% confidence interval [CI] −0.03 to 0.5) and among children who received less than 1 y of post-trial prophylaxis (treatment effect = 0.4 SD, 95% CI 0.1 to 0.8). The intervention group had higher educational attainment by 0.52 grades (95% CI = −0.041 to 1.089; p = 0.069). School enrolment was similar in the two groups. CONCLUSIONS: The results are suggestive of a long-term effect of malaria prophylaxis on cognitive function and educational attainment, but confirmatory studies are needed
HD 213885b: a transiting 1-d-period super-Earth with an Earth-like composition around a bright (V = 7.9) star unveiled by TESS
We report the discovery of the 1.008-d, ultrashort period (USP) super-Earth HD 213885b (TOI-141b) orbiting the bright (V = 7.9) star HD 213885 (TOI-141, TIC 403224672), detected using photometry from the recently launched TESS mission. Using FEROS, HARPS, and CORALIE radial velocities, we measure a precise mass of 8.8 ± 0.6 M⊕ for this 1.74 ± 0.05 R⊕ exoplanet, which provides enough information to constrain its bulk composition – similar to Earth’s but enriched in iron. The radius, mass, and stellar irradiation of HD 213885b are, given our data, very similar to 55 Cancri e, making this exoplanet a good target to perform comparative exoplanetology of short period, highly irradiated super-Earths. Our precise radial velocities reveal an additional 4.78-d signal which we interpret as arising from a second, non-transiting planet in the system, HD 213885c, whose minimum mass of 19.9 ± 1.4 M⊕ makes it consistent with being a Neptune-mass exoplanet. The HD 213885 system is very interesting from the perspective of future atmospheric characterization, being the second brightest star to host an USP transiting super-Earth (with the brightest star being, in fact, 55 Cancri). Prospects for characterization with present and future observatories are discussed
The Equifinality of Archaeological Networks: an Agent-Based Exploratory Lab Approach
When we find an archaeological network, how can we explore the necessary versus contingent processes at play in the formation of that archaeological network? Given a set of circumstances or processes, what other possible network shapes could have emerged? This is the problem of equifinality, where many different means could potentially arrive at the same end result: the networks that we observe. This paper outlines how agent-based modelling can be used as a laboratory for exploring different processes of archaeological network formation. We begin by describing our best guess about how the (ancient) world worked, given our target materials (here, the networks of production and patronage surrounding the Roman brick industry in the hinterland of Rome). We then develop an agent-based model of the Roman extractive economy which generates different kinds of networks under various assumptions about how that economy works. The rules of the simulation are built upon the work of Bang (2006; 2008) who describes a model of the Roman economy which he calls the ‘imperial Bazaar’. The agents are allowed to interact, and the investigators compare the kinds of networks this description generates over an entire landscape of economic possibilities. By rigorously exploring this landscape, and comparing the resultant networks with those observed in the archaeological materials, the investigators will be able to employ the principle of equifinality to work out the representativeness of the archaeological network and thus the underlying processes
Lack of antiviral activity of probenecid in vitro and in Syrian golden hamsters
Objectives
Antiviral interventions are required to complement vaccination programmes and reduce the global burden of COVID-19. Prior to initiation of large-scale clinical trials, robust preclinical data to support candidate plausibility are required. This work sought to further investigate the putative antiviral activity of probenecid against SARS-CoV-2.
Methods
Vero E6 cells were preincubated with probenecid, or control media for 2 h before infection (SARS-CoV-2/Human/Liverpool/REMRQ0001/2020). Probenecid or control media was reapplied, plates reincubated and cytopathic activity quantified by spectrophotometry after 48 h. In vitro human airway epithelial cell (HAEC) assays were performed for probenecid against SARS-CoV-2-VoC-B.1.1.7 (hCoV-19/Belgium/rega-12211513/2020; EPI_ISL_791333, 2020-12-21) using an optimized cell model for antiviral testing. Syrian golden hamsters were intranasally inoculated (SARS-CoV-2 Delta B.1.617.2) 24 h prior to treatment with probenecid or vehicle for four twice-daily doses.
Results
No observable antiviral activity for probenecid was evident in Vero E6 or HAEC assays. No reduction in total or subgenomic RNA was observed in terminal lung samples (P &gt; 0.05) from hamsters. Body weight of uninfected hamsters remained stable whereas both probenecid- and vehicle-treated infected hamsters lost body weight (P &gt; 0.5).
Conclusions
These data do not support probenecid as a SARS-CoV-2 antiviral drug
Dose prediction for repurposing nitazoxanide in SARS-CoV-2 treatment or chemoprophylaxis
Background
Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has been declared a global pandemic and urgent treatment and prevention strategies are needed. Nitazoxanide, an anthelmintic drug has been shown to exhibit in vitro activity against SARS‐CoV‐2. The present study used physiologically‐based pharmacokinetic (PBPK) modelling to inform optimal doses of nitazoxanide capable of maintaining plasma and lung tizoxanide exposures above the reported SARS‐CoV‐2 EC90.
Methods
A whole‐body PBPK model was validated against available pharmacokinetic data for healthy individuals receiving single and multiple doses between 500–4000 mg with and without food. The validated model was used to predict doses expected to maintain tizoxanide plasma and lung concentrations above the EC90 in >90% of the simulated population. PopDes was used to estimate an optimal sparse sampling strategy for future clinical trials.
Results
The PBPK model was successfully validated against the reported human pharmacokinetics. The model predicted optimal doses of 1200 mg QID, 1600 mg TID, 2900 mg BID in the fasted state and 700 mg QID, 900 mg TID and 1400 mg BID when given with food. For BID regimens an optimal sparse sampling strategy of 0.25, 1, 3 and 12h post dose was estimated.
Conclusion
The PBPK model predicted tizoxanide concentrations within doses of nitazoxanide already given to humans previously. The reported dosing strategies provide a rational basis for design of clinical trials with nitazoxanide for the treatment or prevention of SARS‐CoV‐2 infection. A concordant higher dose of nitazoxanide is now planned for investigation in the seamless phase I/IIa AGILE trial (www.agiletrial.net)
Multivalent bicyclic peptides are an effective antiviral modality that can potently inhibit SARS-CoV-2.
COVID-19 has stimulated the rapid development of new antibody and small molecule therapeutics to inhibit SARS-CoV-2 infection. Here we describe a third antiviral modality that combines the drug-like advantages of both. Bicycles are entropically constrained peptides stabilized by a central chemical scaffold into a bi-cyclic structure. Rapid screening of diverse bacteriophage libraries against SARS-CoV-2 Spike yielded unique Bicycle binders across the entire protein. Exploiting Bicycles' inherent chemical combinability, we converted early micromolar hits into nanomolar viral inhibitors through simple multimerization. We also show how combining Bicycles against different epitopes into a single biparatopic agent allows Spike from diverse variants of concern (VoC) to be targeted (Alpha, Beta, Delta and Omicron). Finally, we demonstrate in both male hACE2-transgenic mice and Syrian golden hamsters that both multimerized and biparatopic Bicycles reduce viraemia and prevent host inflammation. These results introduce Bicycles as a potential antiviral modality to tackle new and rapidly evolving viruses