Publications by authors named "Felix Neumann"
Stress Perception, Sleep Quality and Work Engagement of German Outpatient Nurses during the COVID-19 Pandemic.
Monika Bernburg Mara Shirin Hetzmann Natascha Mojtahedzadeh Felix Alexander Neumann Matthias Augustin Volker Harth David Alexander Groneberg Birgit-Christiane Zyriax Stefanie Mache
Int J Environ Res Public Health 2021 12 28;19(1). Epub 2021 Dec 28.
Institute of Occupational, Social and Environmental Medicine, Goethe-University Frankfurt am Main, 60590 Frankfurt, Germany.
Since the outbreak of the COVID-19 pandemic, outpatient nurses have been exposed to a double burden of already known occupational and new pandemic-related stressors. Recent studies suggest that increased pandemic-related stress can affect mental health and promote the development of negative mental health outcomes for nurses. This includes a decrease in sleep quality and work engagement. In addition, certain groups appear to be particularly vulnerable to pandemic-related stress. The aim of this study was to investigate the stress perception of German outpatient nurses during the COVID-19 pandemic. The aim was to determine associations between their pandemic-related stress and variables such as sleep quality, work engagement, pandemic-related worries and concerns. For this purpose, a questionnaire was developed based on well-established measurement instruments such as the 10-item Perceived Stress Scale, the Pittsburgh Sleep Quality Index and the Copenhagen Psychosocial Questionnaire to conduct a cross-sectional online survey among outpatient nurses from Germany. Participants ( = 166) showed rather moderate overall pandemic-related stress levels, good sleep quality, high work engagement, and moderate pandemic-related worries and concerns. Pandemic-related stress proved to be a predictor of decreased sleep quality and work engagement of outpatient nurses with weak effect sizes. Despite the surprisingly moderate stress levels, the effects of pandemic-related stress on selected aspects of participants' mental health could be demonstrated. Therefore, behavioural and organisational health promotion measures are recommended to support outpatient nurses during the pandemic. However, further research is needed to determine the causal relationships and long-term effects of pandemic-related stress on the mental health of outpatient caregivers.
http://dx.doi.org/10.3390/ijerph19010313 DOI Listing
Measurement Methods of Fatigue, Sleepiness, and Sleep Behaviour Aboard Ships: A Systematic Review.
Fiona Kerkamm Dorothee Dengler Matthias Eichler Danuta Materzok-Köppen Lukas Belz Felix Alexander Neumann Birgit Christiane Zyriax Volker Harth Marcus Oldenburg
Int J Environ Res Public Health 2021 Dec 23;19(1). Epub 2021 Dec 23.
Institute for Occupational and Maritime Medicine Hamburg (ZfAM), University Medical Center Hamburg-Eppendorf (UKE), 20459 Hamburg, Germany.
Since seafarers are known to be exposed to numerous job-related stress factors that can cause fatigue, sleepiness, and disturbed sleep behaviour, the aim of this review was to provide an overview of the subjective and objective measurement methods of these strains. Using a systematic review, 166 studies were identified within the period of January 2010 to December 2020 using the PubMed database. Of the 21 studies selected, 13 used both subjective and objective measurement methods. Six studies used only subjective and two studies only objective methods. For subjective assessment, 12 different questionnaires could be identified as well as activity and sleeping logs. Actigraphy and reaction time tests (RTT) were the most common objective methods. In single cases, electrooculography (EOG), pupillometry and ambulatory polysomnography (PSG) were used. Measurement-related limitations due to vessel-related impacts were less often reported than expected. No restrictions of daily routines on board were described, and only single-measurement disturbances due to ship movements were mentioned. The present literature review reveals that there are various routines to measure fatigue, sleepiness, and sleep behaviour on board. A combination of subjective and objective methods often appears to be beneficial. The frequent use of actigraphy and RTT on board suggests good feasibility and reliable measurements with these methods. The use of ambulatory PSG in maritime-like contexts suggests that this method would also be feasible on board.
Workplace Health Promotion and COVID-19 Support Measures in Outpatient Care Services in Germany: A Quantitative Study.
Felix Alexander Neumann Elisabeth Rohwer Natascha Mojtahedzadeh Nataliya Makarova Albert Nienhaus Volker Harth Matthias Augustin Stefanie Mache Birgit-Christiane Zyriax
Int J Environ Res Public Health 2021 11 18;18(22). Epub 2021 Nov 18.
Midwifery Science-Health Services Research and Prevention, Institute for Health Services Research in Dermatology and Nursing (IVDP), University Medical Center Hamburg-Eppendorf (UKE), Martinistr. 52, 20246 Hamburg, Germany.
Working conditions in the care sector, especially under the increased strain during COVID-19, make it difficult for outpatient caregivers to adhere to health-promoting behaviours. Research on workplace health promotion (WHP) and COVID-19 support measures in outpatient care services is limited. The aim of this pilot study was to characterise the current situation of WHP and COVID-19 support measures in outpatient care services and to explore how to offer WHP support measures targeted for a specific group. A web-based cross-sectional survey was conducted with outpatient caregivers ( = 171) in northern Germany. The results showed that 60.2% of the study participants were offered WHP support measures, with significantly higher work engagement when WHP support measures were available ( = 4279.50, < 0.01) and that 77.2% received specific support from their employer during the COVID-19 pandemic. Although spending a break in a break room was significantly associated with longer breaks as compared with being in a car ( = 39.10, = 0.01), a break room was neither available in all outpatient care services, nor did it appear to be feasible. Overall, WHP in outpatient care services is insufficiently covered. In order to be able to offer WHP support measures that are targeted to outpatient caregivers, cooperation among local care services, feasibility, and digital measures should be examined.
http://dx.doi.org/10.3390/ijerph182212119 DOI Listing
The Role of Health Literacy among Outpatient Caregivers during the COVID-19 Pandemic.
Elisabeth Rohwer Natascha Mojtahedzadeh Felix Alexander Neumann Albert Nienhaus Matthias Augustin Volker Harth Birgit-Christiane Zyriax Stefanie Mache
Int J Environ Res Public Health 2021 11 9;18(22). Epub 2021 Nov 9.
Institute for Occupational and Maritime Medicine (ZfAM), University Medical Center Hamburg-Eppendorf (UKE), Seewartenstr. 10, Hs. 1, 20459 Hamburg, Germany.
Health literacy became an important competence during the COVID-19 pandemic. Despite outpatient caregivers being a particularly vulnerable occupational group, their health literacy has hardly been examined yet, especially during the pandemic. Hence, this study aimed to explore this field and provide first empirical insights. Data were collected based on a cross-sectional online survey among 155 outpatient caregivers. In particular, health literacy (HLS-EU-Q16), diet and physical activity, pandemic-related worries, perceived information sufficiency and stress perception were examined. Descriptive and ordinal logistic regression analyses were run to test explorative assumptions. The majority of outpatient caregivers reported high values of health literacy (69% on a sufficient level). Although no significant associations between health literacy and health behaviours or perceived information sufficiency were found, perceived information sufficiency and perceived stress ( = 3.194; 95% CI: 1.542-6.614), and pandemic-related worries ( = 3.073; 95% CI: 1.471-6.421; = 4.243; 95% CI: 2.027-8.884) seem to be related. Therefore, dissemination of reliable information and resource-building measures to reduce worries may be important parameters for improving outpatient caregivers' health. Our results provide first explorative insights, representing a starting point for further research. Considering outpatient caregivers' mobile work setting, they need to be provided with adequate equipment and comprehensible information to ensure physically and mentally healthy working conditions.
Eating behaviour and weight development of European and Asian seafarers during stay on board and at home.
Felix Alexander Neumann Lukas Belz Dorothee Dengler Volker Harth Thomas von Münster Joachim Westenhöfer Marcus Oldenburg Birgit-Christiane Zyriax
J Occup Med Toxicol 2021 Sep 14;16(1):41. Epub 2021 Sep 14.
Midwifery Science - Health Services Research and Prevention, Institute for Health Services Research in Dermatology and Nursing (IVDP), University Medical Center Hamburg-Eppendorf (UKE), Martinistraße 52, N26, 20246, Hamburg, Germany.
Background: Food choices on board merchant ships are limited and seafarers repeatedly described as being at high risk of developing overweight compared to the general population. Up to date, research has not distinguished whether seafarers gain weight on board or at home and whether eating habits differ in both settings.
Methods: As part of the e-healthy ship project, cross-sectional data were collected in two different measurements. In the first investigation on board of three merchant ships of German shipping companies, differences in eating behaviour at home compared to on board ships were assessed for 18 Burmese, 26 Filipino and 20 European seafarers. In a second study, BMI, weight development and location of body weight change of 543 Filipino and 277 European seafarers were examined using an online questionnaire on 68 ships.
Results: According to the board examinations, foods and beverages consumed on merchant ships varied widely from seafarers' diets in their home country. Burmese, Filipino and European seafarers equally reported to consume more fruit (z = 4.95, p < .001, r = .62) and vegetables (z = 6.21, p < .001, r = .79), but less coke (z = -5.00, p < .001, r = .76) when at home. Furthermore, culturally different changes were found across all other foods and beverages. The online questionnaire revealed that 45.8% of seafarers were overweight (55.4% Europeans vs. 40.8% Filipinos, p < .001) and 9.8% obese. Moreover, a higher percentage of Europeans compared to Filipinos reported weight gain over the course of their professional career (50.2% vs. 40.7%, p = .007). A sub-analysis of seafarers with weight gain found that more Europeans than Filipinos gained weight at home (43.9% vs. 23.1%, p < .001).
Conclusions: Both, home and working on board merchant ships, represent very different living environments which may affect seafarers' lifestyle and eating habits in various ways and thus could favour or inhibit weight gain. From our results, it appears that the body weight and eating habits of Asian seafarers in particular are adversely affected by the working and living conditions on board. Further prospective studies are required to prove this hypothesis.
The Health Behaviour of German Outpatient Caregivers in Relation to the COVID-19 Pandemic: A Mixed-Methods Study.
Natascha Mojtahedzadeh Felix Alexander Neumann Elisabeth Rohwer Albert Nienhaus Matthias Augustin Volker Harth Birgit-Christiane Zyriax Stefanie Mache
Int J Environ Res Public Health 2021 08 3;18(15). Epub 2021 Aug 3.
Institute for Occupational and Maritime Medicine (ZfAM), University Medical Center Hamburg-Eppendorf (UKE), 20459 Hamburg, Germany.
The COVID-19 pandemic has affected outpatient caregivers in a particular way. While the German population becomes increasingly older, the number of people in need of care has also increased. The health and, thus, the health behaviour of employees in the outpatient care become relevant to maintain working capacity and performance in the long term. The aims of the study were (1) to examine the health behaviour and (2) to explore pandemic-related perceived change of health behaviour among outpatient caregivers during the COVID-19 pandemic. In a mixed-methods study, 15 problem-centred interviews and a web-based cross-sectional survey ( = 171) were conducted with outpatient caregivers working in Northern Germany. Interviewees reported partially poorer eating behaviour, higher coffee consumption, lower physical activity, skipping breaks more often and less sleep duration and quality during the pandemic. Some quantitative findings indicate the same tendencies. A majority of participants were smokers and reported higher stress perception due to the pandemic. Preventive behaviour, such as wearing PPE or hand hygiene, was increased among interviewees compared to the pre-pandemic period. Our findings indicate that the COVID-19 pandemic could negatively affect outpatient caregivers' health behaviour, e.g., eating/drinking behaviour and physical activity. Therefore, employers in outpatient care should develop workplace health promotion measures to support their employees in conducting more health-promoting behaviours during the COVID-19 pandemic.
The Health Behaviour of German Outpatient Caregivers in Relation to Their Working Conditions: A Qualitative Study.
Natascha Mojtahedzadeh Elisabeth Rohwer Felix Alexander Neumann Albert Nienhaus Matthias Augustin Birgit-Christiane Zyriax Volker Harth Stefanie Mache
Int J Environ Res Public Health 2021 06 1;18(11). Epub 2021 Jun 1.
Institute for Occupational and Maritime Medicine (ZfAM), University Medical Centre, Hamburg-Eppendorf (UKE), Seewartenstr. 10, 20459 Hamburg, Germany.
Ongoing demographic change is leading to an increasingly older society and a rising proportion of people in need of care in the German population. Therefore, the professional group of outpatient caregivers is highly relevant. Their work is characterised not only by interacting with patients in a mobile setting but also by working in shifts. Health behaviour under these specific working conditions is crucial for ensuring long-term work ability and performance. Little is known about the health behaviour of German outpatient caregivers and its potential impact on their work. The aims of the study were (1) to examine health behavioural patterns (nutrition, exercise, smoking, regeneration) of outpatient caregivers, (2) to illuminate their personal health-promoting behaviours, and (3) to identify potential work-related factors influencing their health behaviour. Fifteen problem-centred interviews were conducted with outpatient caregivers working in Northern Germany in the period January-April 2020. Interviews were analysed by using qualitative content analysis. Outpatient caregivers reported improvable nutrition and hydration, with simultaneous high coffee consumption, low physical activity, poor regeneration (breaks and sleep quality), and good personal health-promoting behaviour (e.g., back-friendly habits), although the majority were smokers. Barriers to the implementation of health-promoting behaviours were a high perception of stress due to increased workload and time pressure, while aids to better health-promoting behaviour were described as being social support and personal resources. The respondents perceived their working conditions as potentially influencing their health behaviour. On the basis of their descriptions, various practice-relevant strategies were derived. The data explore a potential need for outpatient care services to develop interventions on behavioural and structural levels that can help create healthier working conditions for their employees so these caregivers can adopt better health behaviours.
Evaluation of Immuno-Rolling Circle Amplification for Multiplex Detection and Profiling of Antigen-Specific Antibody Isotypes.
Sara Horta Felix Neumann Shu-Hao Yeh Christoffer Mattsson Langseth Kadri Kangro Jolien Breukers Narayanan Madaboosi Nick Geukens Karen Vanhoorelbeke Mats Nilsson Jeroen Lammertyn
Anal Chem 2021 04 7;93(15):6169-6177. Epub 2021 Apr 7.
Department of Biosystems, Biosensors Group, KU Leuven, Willem De Croylaan 42, Heverlee B-3001, Belgium.
Antibody characterization is essential for understanding the immune system and development of diagnostics and therapeutics. Current technologies are mainly focusing on the detection of antigen-specific immunoglobulin G (IgG) using bulk singleplex measurements, which lack information on other isotypes and specificity of individual antibodies. Digital immunoassays based on nucleic acid amplification have demonstrated superior performance by allowing the detection of single molecules in a multiplex and sensitive manner. In this study, we demonstrate for the first time an immuno-rolling circle amplification (immuno-RCA) assay for the multiplex detection of three antigen-specific antibody isotypes (IgG, IgA, and IgM) and its integration with microengraving. To validate this approach, we used the autoimmune disease immune-mediated thrombotic thrombocytopenic purpura (iTTP) as the model disease with anti-ADAMTS13 autoantibodies as the diagnostic target molecules. To identify the anti-ADAMTS13 autoantibody isotypes, we designed a pool of three unique antibody-oligonucleotide conjugates for identification and subsequent amplification and visualization via RCA. To validate this approach, we first confirmed an assay specificity of >88% and a low limit of detection of 0.3 ng/mL in the spiked buffer. Subsequently, we performed a dilution series of an iTTP plasma sample for the multiplex detection of the three isotypes with higher sensitivity compared to an enzyme-linked immunosorbent assay. Finally, we demonstrated single-cell analysis of human B cells and hybridoma cells for the detection of secreted antibodies using microengraving and achieved a detection of 23.3 pg/mL secreted antibodies per hour. This approach could help to improve the understanding of antibody isotype distributions and their roles in various diseases.
http://dx.doi.org/10.1021/acs.analchem.1c00172 DOI Listing
Value of Panendoscopy in the Identification of Synchronous Malignancies in Patients Suffering from Oral Squamous Cell Carcinoma Without Clinical Signs of a Second Primary Tumor.
Steffen Koerdt Jan-Dirk Raguse Felix Neumann Benedicta Beck-Broichsitter Kilian Kreutzer Konrad Neumann Max Heiland Christian Doll
Anticancer Res 2021 Apr;41(4):2039-2044
Department of Oral and Maxillofacial Surgery, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
Background/aim: The aim of the present study was to assess the value of panendoscopy of the upper aero-digestive tract in the identification of synchronous tumors in OSCC patients without clinical signs of a second primary tumor.
Patients And Methods: In this retrospective study, patients diagnosed with a primary OSCC who received surgical therapy between January 1, 2012 and December 31, 2017 were included. Participants must have undergone panendoscopy during the staging process. None of these patients showed clinical signs of a second primary tumor.
Results: A total of 265 patients (99 females and 166 males; mean age=63.3 years, range=26-96 years) were included. The mean (SD) follow-up was 25.88 (±20.479 SD) months. Five synchronous secondary tumors (1.9%) could be identified within this cohort. Of these, only two (0.8%) were located within the area of panendoscopy and were diagnosed in patients with regular alcohol and/or tobacco abuse. Eighteen metachronous second primary tumors were diagnosed, 10 being located within the upper aero-digestive tract.
Conclusion: The relevance of routinely performed panendoscopy in patients suffering from an oral squamous cell carcinoma without clinical signs of a secondary tumor should be critically re-evaluated, especially in patients without typical risk factors.
http://dx.doi.org/10.21873/anticanres.14972 DOI Listing
The sweet detection of rolling circle amplification: Glucose-based electrochemical genosensor for the detection of viral nucleic acid.
Sibel Ciftci Rocío Cánovas Felix Neumann Thomas Paulraj Mats Nilsson Gaston A Crespo Narayanan Madaboosi
Biosens Bioelectron 2020 Mar 30;151:112002. Epub 2019 Dec 30.
Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Sweden. Electronic address:
Herein, an isothermal padlock probe-based assay for the simple and portable detection of pathogens coupled with a glucose oxidase (GOx)-based electrochemical readout is reported. Infectious diseases remain a constant threat on a global scale, as in recurring pandemics. Rapid and portable diagnostics hold the promise to tackle the spreading of diseases and decentralising healthcare to point-of-care needs. Ebola, a hypervariable RNA virus causing fatalities of up to 90% for recent outbreaks in Africa, demands immediate attention for bedside diagnostics. The design of the demonstrated assay consists of a rolling circle amplification (RCA) technique, responsible for the generation of nucleic acid amplicons as RCA products (RCPs). The RCPs are generated on magnetic beads (MB) and subsequently, connected via streptavidin-biotin bonds to GOx. The enzymatic catalysis of glucose by the bound GOx allows for an indirect electrochemical measurement of the DNA target. The RCPs generated on the surface of the MB were confirmed by scanning electron microscopy, and among other experimental conditions such as the type of buffer, temperature, concentration of GOx, sampling and measurement time were evaluated for the optimum electrochemical detection. Accordingly, 125 μg mL of GOx with 5 mM glucose using phosphate buffer saline (PBS), monitored for 1 min were selected as the ideal conditions. Finally, we assessed the analytical performance of the biosensing strategy by using clinical samples of Ebola virus from patients. Overall, this work provides a proof-of-concept bioassay for simple and portable molecular diagnostics of emerging pathogens using electrochemical detection, especially in resource-limited settings.
http://dx.doi.org/10.1016/j.bios.2019.112002 DOI Listing
Digital Rolling Circle Amplification-Based Detection of Ebola and Other Tropical Viruses.
Sibel Ciftci Felix Neumann Samir Abdurahman K Sofia Appelberg Ali Mirazimi Mats Nilsson Narayanan Madaboosi
J Mol Diagn 2020 02 16;22(2):272-283. Epub 2019 Dec 16.
Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden. Electronic address:
Emerging tropical viruses have caused serious outbreaks during the recent years, such as Ebola virus (EBOV) in 2014 and the most recent in 2018 to 2019 in Congo. Thus, immediate diagnostic attention is demanded at the point of care in resource-limited settings, because the performance and the operational parameters of conventional EBOV testing are limited. Especially, their sensitivity, specificity, and coverage of other tropical disease viruses make them unsuitable for diagnostic at the point of care. Here, a padlock probe (PLP)-based rolling circle amplification (RCA) method for the detection of EBOV is presented. For this, a set of PLPs, separately targeting the viral RNA and complementary RNA of all seven EBOV genes, was used in the RCA assay and validated on virus isolates from cell culture. The assay was then translated for testing clinical samples, and simultaneous detection of both EBOV RNA types was demonstrated. For increased sensitivity, the RCA products were enriched on a simple and pump-free microfluidic chip. Because PLPs and RCA are inherently multiplexable, we demonstrate the extension of the probe panel for the simultaneous detection of the tropical viruses Ebola, Zika, and Dengue. The demonstrated high specificity, sensitivity, and multiplexing capability in combination with the digital quantification rendered the assay a promising diagnostic tool toward tropical virus detection at the point of care.
http://dx.doi.org/10.1016/j.jmoldx.2019.10.014 DOI Listing
A novel mutation tolerant padlock probe design for multiplexed detection of hypervariable RNA viruses.
Sibel Ciftci Felix Neumann Iván Hernández-Neuta Mikhayil Hakhverdyan Ádám Bálint David Herthnek Narayanan Madaboosi Mats Nilsson
Sci Rep 2019 02 27;9(1):2872. Epub 2019 Feb 27.
Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, SE- 171 65, Solna, Sweden.
The establishment of a robust detection platform for RNA viruses still remains a challenge in molecular diagnostics due to their high mutation rates. Newcastle disease virus (NDV) is one such RNA avian virus with a hypervariable genome and multiple genotypes. Classical approaches like virus isolation, serology, immunoassays and RT-PCR are cumbersome, and limited in terms of specificity and sensitivity. Padlock probes (PLPs) are known for allowing the detection of multiple nucleic acid targets with high specificity, and in combination with Rolling circle amplification (RCA) have permitted the development of versatile pathogen detection assays. In this work, we aimed to detect hypervariable viruses by developing a novel PLP design strategy capable of tolerating mutations while preserving high specificity by targeting several moderately conserved regions and using degenerate bases. For this, we designed nine padlock probes based on the alignment of 335 sequences covering both Class I and II NDV. Our PLP design showed high coverage and specificity for the detection of eight out of ten reported genotypes of Class II NDV field isolated strains, yielding a detection limit of less than ten copies of viral RNA. Further taking advantage of the multiplex capability of PLPs, we successfully extended the assay for the simultaneous detection of three poultry RNA viruses (NDV, IBV and AIV) and combined it with a paper based microfluidic enrichment read-out for digital quantification. In summary, our novel PLP design addresses the current issue of tolerating mutations of highly emerging virus strains with high sensitivity and specificity.
Silica bead-based microfluidic device with integrated photodiodes for the rapid capture and detection of rolling circle amplification products in the femtomolar range.
Ruben R G Soares Felix Neumann Catarina R F Caneira Narayanan Madaboosi Sibel Ciftci Iván Hernández-Neuta Inês F Pinto Denis R Santos Virginia Chu Aman Russom João P Conde Mats Nilsson
Biosens Bioelectron 2019 Mar 18;128:68-75. Epub 2018 Dec 18.
Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, SE-171 65 Solna, Sweden. Electronic address:
The rapid and sensitive detection of specific nucleic acid sequences at the point-of-care (PoC) is becoming increasingly in demand for a variety of emergent biomedical applications ranging from infectious disease diagnostics to the screening of antimicrobial resistance. To meet such demand, considerable efforts have been invested towards the development of portable and integrated analytical devices combining microfluidics with miniaturized signal transducers. Here, we demonstrate the combination of rolling circle amplification (RCA)-based nucleic acid amplification with an on-chip size-selective trapping of amplicons on silica beads (~8 nL capture chamber) coupled with a thin-film photodiode (200 × 200 µm area) fluorescence readout. Parameters such as the flow rate of the amplicon solution and trapping time were optimized as well as the photodiode measurement settings, providing minimum detection limits below 0.5 fM of targeted nucleic acids and requiring only 5 μL of pre-amplified sample. Finally, we evaluated the analytical performance of our approach by benchmarking it against a commercial instrument for RCA product (RCP) quantification and further investigated the effect of the number of RCA cycles and elongation times (ranging from 10 to 120 min). Moreover, we provide a demonstration of the application for diagnostic purposes by detecting RNA from influenza and Ebola viruses, thus highlighting its suitability for integrated PoC systems.
http://dx.doi.org/10.1016/j.bios.2018.12.004 DOI Listing
Padlock Probe Assay for Detection and Subtyping of Seasonal Influenza.
Felix Neumann Iván Hernández-Neuta Malin Grabbe Narayanan Madaboosi Jan Albert Mats Nilsson
Clin Chem 2018 12 26;64(12):1704-1712. Epub 2018 Sep 26.
Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden;
Background: Influenza remains a constant threat worldwide, and WHO estimates that it affects 5% to 15% of the global population each season, with an associated 3 to 5 million severe cases and up to 500000 deaths. To limit the morbidity and the economic burden of influenza, improved diagnostic assays are needed.
Methods: We developed a multiplexed assay for the detection and subtyping of seasonal influenza based on padlock probes and rolling circle amplification. The assay simultaneously targets all 8 genome segments of the 4 circulating influenza variants-A(H1N1), A(H3N2), B/Yamagata, and B/Victoria-and was combined with a prototype cartridge for inexpensive digital quantification. Characterized virus isolates and patient nasopharyngeal swabs were used for assay design and analytical validation. The diagnostic performance was assessed by blinded testing of 50 clinical samples analyzed in parallel with a commercial influenza assay, Simplexa™ Flu A/B & RSV Direct.
Results: The assay had a detection limit of 18 viral RNA copies and achieved 100% analytical and clinical specificity for differential detection and subtyping of seasonal circulating influenza variants. The diagnostic sensitivity on the 50 clinical samples was 77.5% for detecting influenza and up to 73% for subtyping seasonal variants.
Conclusions: We have presented a proof-of-concept padlock probe assay combined with an inexpensive digital readout for the detection and subtyping of seasonal influenza strains A and B. The demonstrated high specificity and multiplexing capability, together with the digital quantification, established the assay as a promising diagnostic tool for seasonal influenza.
http://dx.doi.org/10.1373/clinchem.2018.292979 DOI Listing
Analysis of main effect QTL for thousand grain weight in European winter wheat (Triticum aestivum L.) by genome-wide association mapping.
Christine D Zanke Jie Ling Jörg Plieske Sonja Kollers Erhard Ebmeyer Viktor Korzun Odile Argillier Gunther Stiewe Maike Hinze Felix Neumann Andrea Eichhorn Andreas Polley Cornelia Jaenecke Martin W Ganal Marion S Röder
Front Plant Sci 2015 1;6:644. Epub 2015 Sep 1.
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Germany.
Grain weight, an essential yield component, is under strong genetic control and at the same time markedly influenced by the environment. Genetic analysis of the thousand grain weight (TGW) by genome-wide association study (GWAS) was performed with a panel of 358 European winter wheat (Triticum aestivum L.) varieties and 14 spring wheat varieties using phenotypic data of field tests in eight environments. Wide phenotypic variations were indicated for the TGW with BLUEs (best linear unbiased estimations) values ranging from 35.9 to 58.2 g with a mean value of 45.4 g and a heritability of H(2) = 0.89. A total of 12 candidate genes for plant height, photoperiodism and grain weight were genotyped on all varieties. Only three candidates, the photoperiodism gene Ppd-D1, dwarfing gene Rht-B1and the TaGW-6A gene were significant explaining up to 14.4, 2.3, and 3.4% of phenotypic variation, respectively. For a comprehensive genome-wide analysis of TGW-QTL genotyping data from 732 microsatellite markers and a set of 7769 mapped SNP-markers genotyped with the 90k iSELECT array were analyzed. In total, 342 significant (-log10 (P-value) ≥ 3.0) marker trait associations (MTAs) were detected for SSR-markers and 1195 MTAs (-log10(P-value) ≥ 3.0) for SNP-markers in all single environments plus the BLUEs. After Bonferroni correction, 28 MTAs remained significant for SSR-markers (-log10 (P-value) ≥ 4.82) and 58 MTAs for SNP-markers (-log10 (P-value) ≥ 5.89). Apart from chromosomes 4B and 6B for SSR-markers and chromosomes 4D and 5D for SNP-markers, MTAs were detected on all chromosomes. The highest number of significant SNP-markers was found on chromosomes 3B and 1B, while for the SSRs most markers were significant on chromosomes 6D and 3D. Overall, TGW was determined by many markers with small effects. Only three SNP-markers had R(2) values above 6%.
http://dx.doi.org/10.3389/fpls.2015.00644 DOI Listing