Standard SARS-CoV-2 testing protocols using nasopharyngeal/throat (NP/T) swabs are invasive and require trained medical staff for reliable sampling. In addition, it has been shown that PCR is more sensitive as compared to antigen-based tests. Here we describe the analytical and clinical evaluation of our in-house RNA extraction-free saliva-based molecular assay for the detection of SARS-CoV-2. Analytical sensitivity of the test was equal to the sensitivity obtained in other Dutch diagnostic laboratories that process NP/T swabs. In this study, 955 individuals participated and provided NP/T swabs for routine molecular analysis (with RNA extraction) and saliva for comparison. Our RT-qPCR resulted in a sensitivity of 82,86% and a specificity of 98,94% compared to the gold standard. A false-negative ratio of 1,9% was found. The SARS-CoV-2 detection workflow described here enables easy, economical, and reliable saliva processing, useful for repeated testing of individuals.
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In het werkveld van Life Sciences & Chemistry heeft Innovative testing te maken met het testen van stoffen op hun werking en veiligheid. Met stoffen wordt hier bedoeld alle mogelijke chemicaliën waar aan we blootgesteld worden, zoals chemicaliën in onze leef- en werkomgeving, medicijnen (inclusief biologicals), maar ook stoffen in de voeding (inclusief voedselbestanddelen en natuurlijke stoffen). Mijn les zal echter voornamelijk gaan over de laatste twee categorieën, medicijnen en stoffen in de voeding. Ik wil in mijn openbare les eerst uiteenzetten waarom het zo belangrijk is om vast te stellen wat de werking en veiligheid van stoffen is. Vervolgens wil ik beschrijven welke innovaties op dit moment al plaatsvinden, in de toxicologie en de farmacologie. Dit wil ik doen om aan te geven waar de parallellen en mogelijkheden voor synergie liggen. Daarna zal ik aan de hand van een aantal voorbeelden aangeven tegen welke grenzen men zoal aanloopt bij het testen van werking en veiligheid van stoffen, om daarbij ook aan te geven dat er duidelijk aanwijzingen zijn voor het vervagen van grenzen tussen farmacologie en toxicologie. Tot slot zal ik aangeven welke rol het Kenniscentrum Life Sciences & Chemistry van Hogeschool Utrecht op het gebied van onderzoek én onderwijs in het werkveld van Innovative testing in Life Sciences & Chemistry wil gaan spelen.
Background: The aim of this study is to validate a newly developed nurses' self-efficacy sources inventory. We test the validity of a five-dimensional model of sources of self-efficacy, which we contrast with the traditional four-dimensional model based on Bandura's theoretical concepts. Methods: Confirmatory factor analysis was used in the development of the newly developed self-efficacy measure. Model fit was evaluated based upon commonly recommended goodness-of-fit indices, including the χ2 of the model fit, the Root Mean Square Error of approximation (RMSEA), the Tucker-Lewis Index (TLI), the Standardized Root Mean Square Residual (SRMR), and the Bayesian Information Criterion (BIC). Results: All 22 items of the newly developed five-factor sources of self-efficacy have high factor loadings (range .40-.80). Structural equation modeling showed that a five-factor model is favoured over the four-factor model. Conclusions and implications: Results of this study show that differentiation of the vicarious experience source into a peer- and expert based source reflects better how nursing students develop self-efficacy beliefs. This has implications for clinical learning environments: a better and differentiated use of self-efficacy sources can stimulate the professional development of nursing students.
The missing link in diagnostic testing for rheumatoid arthritis (RA) is an agglutination assay, easy to perform and dedicated to decentralized testing. Approximately 75% of RA patients produce autoantibodies to citrullinated proteins (ACPA), which can be detected using an agglutination-based diagnostic test. Such a diagnostic test will be cheaper, less laborious and faster than current tests and does not require sophisticated equipment. Novio Catalpa is developing this alternative test for ACPA in collaboration with Radboud University. To develop this test, specifically tagged and citrullinated nanobodies are needed, but the production is still challenging. Current methods for the production of ACPA diagnostics involve chemical synthesis, in which a variety of toxic chemicals are used in each step. The alternative assay involves nanobodies fused with RA-biomarker target entities, which can be completely produced by ‘green synthesis’ in the yeast Pichia pastoris using the expertise of HAN BioCentre. The yeast P. pastoris has proven to be able to produce nanobodies and is a fast and cost-effective platform that often results in high protein yields. Goal of the project is therefore to determine the feasibility and best green route to produce purified nanobodies tagged with citrullinated ACPA targets that can be used for developing an agglutination assay for RA. P. pastoris does not produce endogenous PAD enzymes which are needed for citrullination of the nanobodies in order to be able to use it in a RA agglutination test. Therefore, PAD enzymes from other sources need to be tested and applied. The project results will be directly used by Novio Catalpa to further develop the innovative test for RA. This project will contribute to and finally result in a single-step agglutination assay suitable for both point-of-care testing and automation in clinical laboratories.
Organ-on-a-chip technology holds great promise to revolutionize pharmaceutical drug discovery and development which nowadays is a tremendously expensive and inefficient process. It will enable faster, cheaper, physiologically relevant, and more reliable (standardized) assays for biomedical science and drug testing. In particular, it is anticipated that organ-on-a-chip technology can substantially replace animal drug testing with using the by far better models of true human cells. Despite this great potential and progress in the field, the technology still lacks standardized protocols and robust chip devices, which are absolutely needed for this technology to bring the abovementioned potential to fruition. Of particular interest is heart-on-a-chip for drug and cardiotoxicity screening. There is presently no preclinical test system predicting the most important features of cardiac safety accurately and cost-effectively. The main goal of this project is to fabricate standardized, robust generic heart-on-a-chip demonstrator devices that will be validated and further optimized to generate new physiologically relevant models to study cardiotoxicity in vitro. To achieve this goal various aspects will be considered, including (i) the search for alternative chip materials to replace PDMS, (ii) inner chip surface modification and treatment (chemistry and topology), (iii) achieving 2D/3D cardiomyocyte (long term) cell culture and cellular alignment within the chip device, (iv) the possibility of integrating in-line sensors in the devices and, finally, (v) the overall chip design. The achieved standardized heart-on-a-chip technology will be adopted by pharmaceutical industry. This proposed project offers a unique opportunity for the Netherlands, and Twente in particular, which has relevant expertise, potential, and future perspective in this field as it hosts world-leading companies pioneering various core aspects of the technology that are relevant for organs-on-chips, combined with two world-leading research institutes within the University of Twente.
Although cardiorespiratory fitness (CRF) is being recognized as an important marker of health and functioning, it is currently not routinely assessed in daily clinical practice. There is an urgent need for a simple and feasible exercise test that can validly and reliably estimate an individual’s CRF. The Steep Ramp Test (SRT) is such a practical short-time exercise test (work rate increments of 25 W/10 seconds, so the test phase will only take up to 4 minutes) on a cycle ergometer, that does not require expensive equipment or specialized knowledge, and has been found able to validly and reliably estimate an individual’s CRF. Although the SRT is already frequently used in the Netherlands to evaluate CRF, sex- and age-specific reference values for adults and elderly are lacking thus far, which seriously limits the interpretation of test results.
