Characterisation of the Binding Properties of Bacillus Thuringiensis 18 Toxin on Leukaemic Cells

<p>Abstract</p> <p>Background</p> <p>Various strains of <it>Bacillus thuringiensis </it>(Bt) have been found to produce parasporal proteins that are cytotoxic to human cancer cells. This study aims to establish the binding affinity of purified Bt 18 toxin for CEM-SS (T lymphoblastic leukaemia cell line), to determine if competition exists between the toxin and commercial anticancer drugs for the binding site on CEM-SS and to localise the binding site of the toxin on CEM-SS.</p> <p>Methods</p> <p>In homologous competitive binding study, the purified toxin was labelled with biotin and allowed to compete with unlabelled toxin for binding sites on CEM-SS and its dissociation constant (Kd) was determined. Comparisons were made with CCRF-SB, CCRF-HSB-2 and MCF-7. In heterologous competitive binding study, biotinylated toxin competition was determined with two other Bt toxins (crude Btj and crude Bt 22) and anticancer drugs (cisplatin, doxorubicin, etoposide, navelbine and methotrexate). To localise the binding site under the confocal microscope, the biotinylated toxin was tagged with FITC-conjugated streptavidin.</p> <p>Results</p> <p>Homologous competitive binding assays revealed decreasing binding affinity of Bt 18 toxin for CEM-SS, CCRF-SB, and CCRF-HSB-2 with Kd of 8.44 nM, 14.98 nM and 17.71 nM respectively. Kd for MCF-7 was not determined as the inhibitory concentration (IC₅₀) was not reached. Heterologous competitive study showed little competition (< 30%) between biotinylated Bt 18 toxin and all test compounds used. Confocal microscopy revealed binding of toxin at the periphery of the cell.</p> <p>Conclusions</p> <p>It was postulated that purified Bt 18 toxin binds on the cell surface of CEM-SS and the mechanism of cell death may differ from that of Btj toxin, Bt 22 toxin and all five anticancer drugs used in this study, since it did not significantly compete with these compounds for the same binding site.</p

Simple bounds on limit loads by elastic finite element analysis”, ASME,

A method for bounding limit loads by an iterative elastic continuum finite element analysis procedure, referred to as the elastic compensation method, is proposed. A number of sample problems are considered, based on both exact solutions and finite element analysis, and it is concluded that the method may be used to obtain limitload bounds for pressure vessel design by analysis applications with useful accuracy

Technology enhanced assessment: Ottawa consensus statement and recommendations

INTRODUCTION In 2011, a consensus report was produced on technology-enhanced assessment (TEA), its good practices, and future perspectives. Since then, technological advances have enabled innovative practices and tools that have revolutionised how learners are assessed. In this updated consensus, we bring together the potential of technology and the ultimate goals of assessment on learner attainment, faculty development, and improved healthcare practices. METHODS As a material for the report, we used the scholarly publications on TEA in both HPE and general higher education, feedback from 2020 Ottawa Conference workshops, and scholarly publications on assessment technology practices during the Covid-19 pandemic. RESULTS AND CONCLUSION The group identified areas of consensus that remained to be resolved and issues that arose in the evolution of TEA. We adopted a three-stage approach (readiness to adopt technology, application of assessment technology, and evaluation/dissemination). The application stage adopted an assessment ‘lifecycle’ approach and targeted five key foci: (1) Advancing authenticity of assessment, (2) Engaging learners with assessment, (3) Enhancing design and scheduling, (4) Optimising assessment delivery and recording learner achievement, and (5) Tracking learner progress and faculty activity and thereby supporting longitudinal learning and continuous assessment.Peer reviewe

Improved maintenance for energy optimization in the calcium compound processing industry

Malaysian industries, in general consider energy management a burden and non-profitable. Energy management initiatives are also viewed as a Cost-Centre. An Excel spreadsheet was therefore tailor-designed, which meets the requirements of the plant for energy optimization and management. The spreadsheet is grouped to reflect four parts, namely: plan, do, check and commit. This Plan-Do-Check-Commit cycle is based on the plan-do-check-act (PDCA) cycle. This spreadsheet has been developed with the objective of developing a tool that would be comprehensive, simple and flexible, open to be modified and tailored for the industries. The results indicated that there are opportunities for a more effective and structured approach to energy management in industry. An initial reduction of 5% in energy consumption has been recorded and it is the company’s responsibility to ensure that their energy management becomes part of their corporate culture

Anticholinergic medications in patients admitted with cognitive impairment or falls (AMiCI). The impact of hospital admission on anticholinergic cognitive medication burden. Results of a multicentre observational study

What is known and objectiveDrugs with anticholinergic properties increase the risk of falls, delirium, chronic cognitive impairment, and mortality and counteract procholinergic medications used in the treatment of dementia. Medication review and optimisation to reduce anticholinergic burden in patients at risk is recommended by specialist bodies. Little is known how effective this review is in patients who present acutely and how often drugs with anticholinergic properties are used temporarily during an admission. The aim of the study was to describe the changes in the anticholinergic cognitive burden (ACB) in patients admitted to hospital with a diagnosis of delirium, chronic cognitive impairment or falls and to look at the temporary use of anticholinergic medications during hospital stay. MethodsThis is a multi-centre observational study that was conducted in seven different hospitals in the UK, Finland, The Netherlands and Italy. Results and discussion21.1% of patients had their ACB score reduced by a mean of 1.7%, 19.7% had their ACB increased by a mean of 1.6%, 22.8% of DAP naive patients were discharged on anticholinergic medications. There was no change in the ACB scores in 59.2% of patients. 54.1% of patients on procholinergics were taking anticholinergics. Out of the 98 medications on the ACB scale, only 56 were seen. Medications with a low individual burden were accounting for 64.9% of the total burden. Anticholinergic drugs were used temporarily during the admission in 21.9% of all patients. A higher number of DAPs used temporarily during admission was associated with a higher risk of ACB score increase on discharge (OR=1.82, 95% CI for OR: 1.36-2.45, P What is new and conclusionThere was no reduction in anticholinergic cognitive burden during the acute admissions. This was the same for all diagnostic subgroups. The anticholinergic load was predominantly caused by medications with a low individual burden. More than 1 in 5 patients not taking anticholinergics on admission were discharged on them and similar numbers saw temporary use of these medications during their admission. More than half of patients on cholinesterase-inhibitors were taking anticholinergics at the same time on admission, potentially directly counteracting their effects.Peer reviewe

Improving statistical inference on pathogen densities estimated by quantitative molecular methods: malaria gametocytaemia as a case study

BACKGROUND: Quantitative molecular methods (QMMs) such as quantitative real-time polymerase chain reaction (q-PCR), reverse-transcriptase PCR (qRT-PCR) and quantitative nucleic acid sequence-based amplification (QT-NASBA) are increasingly used to estimate pathogen density in a variety of clinical and epidemiological contexts. These methods are often classified as semi-quantitative, yet estimates of reliability or sensitivity are seldom reported. Here, a statistical framework is developed for assessing the reliability (uncertainty) of pathogen densities estimated using QMMs and the associated diagnostic sensitivity. The method is illustrated with quantification of Plasmodium falciparum gametocytaemia by QT-NASBA. RESULTS: The reliability of pathogen (e.g. gametocyte) densities, and the accompanying diagnostic sensitivity, estimated by two contrasting statistical calibration techniques, are compared; a traditional method and a mixed model Bayesian approach. The latter accounts for statistical dependence of QMM assays run under identical laboratory protocols and permits structural modelling of experimental measurements, allowing precision to vary with pathogen density. Traditional calibration cannot account for inter-assay variability arising from imperfect QMMs and generates estimates of pathogen density that have poor reliability, are variable among assays and inaccurately reflect diagnostic sensitivity. The Bayesian mixed model approach assimilates information from replica QMM assays, improving reliability and inter-assay homogeneity, providing an accurate appraisal of quantitative and diagnostic performance. CONCLUSIONS: Bayesian mixed model statistical calibration supersedes traditional techniques in the context of QMM-derived estimates of pathogen density, offering the potential to improve substantially the depth and quality of clinical and epidemiological inference for a wide variety of pathogens

The collateral damage of COVID-19 to cardiovascular services. A meta-Analysis

Aims: The effect of the COVID-19 pandemic on care and outcomes across non-COVID-19 cardiovascular (CV) diseases is unknown. A systematic review and meta-Analysis was performed to quantify the effect and investigate for variation by CV disease, geographic region, country income classification and the time course of the pandemic. Methods and results: From January 2019 to December 2021, Medline and Embase databases were searched for observational studies comparing a pandemic and pre-pandemic period with relation to CV disease hospitalisations, diagnostic and interventional procedures, outpatient consultations, and mortality. Observational data were synthesised by incidence rate ratios (IRR) and risk ratios (RR) for binary outcomes and weighted mean differences for continuous outcomes with 95% confidence intervals. The study was registered with PROSPERO (CRD42021265930). A total of 158 studies, covering 49 countries and 6 continents, were used for quantitative synthesis. Most studies (80%) reported information for high-income countries (HICs). Across all CV disease and geographies there were fewer hospitalisations, diagnostic and interventional procedures, and outpatient consultations during the pandemic. By meta-regression, in low-middle income countries (LMICs) compared to HICs the decline in ST-segment elevation myocardial infarction (STEMI) hospitalisations (RR 0.79, 95% confidence interval [CI] 0.66-0.94) and revascularisation (RR 0.73, 95% CI 0.62-0.87) was more severe. In LMICs, but not HICs, in-hospital mortality increased for STEMI (RR 1.22, 95% CI 1.10-1.37) and heart failure (RR 1.08, 95% CI 1.04-1.12). The magnitude of decline in hospitalisations for CV diseases did not differ between the first and second wave. Conclusions: There was substantial global collateral CV damage during the COVID-19 pandemic with disparity in severity by country income classification