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1.
Eur J Epidemiol ; 2024 May 28.
Article in English | MEDLINE | ID: mdl-38802612

ABSTRACT

INTRODUCTION: Nitrate and nitrite are naturally occurring in both plant- and animal-sourced foods, are used as additives in the processing of meat, and are found in water. There is growing evidence that they exhibit a spectrum of health effects, depending on the dietary source. The aim of the study was to examine source-dependent associations between dietary intakes of nitrate/nitrite and both all-cause and cause-specific mortality. METHODS: In 52,247 participants of the Danish Diet, Cancer and Health Study, associations between source-dependent nitrate and nitrite intakes--calculated using comprehensive food composition and national drinking water quality monitoring databases--and all-cause, cardiovascular disease (CVD)-related, and cancer-related mortality over 27 years were examined using restricted cubic splines within Cox proportional hazards models adjusting for demographic, lifestyle, and dietary confounders. Analyses were stratified by factors hypothesised to influence the formation of carcinogenic N-nitroso compounds (namely, smoking and dietary intakes of vitamin C, vitamin E, folate, and polyphenols). RESULTS: Plant-sourced nitrate intake was inversely associated with all-cause mortality [HRQ5vsQ1: 0.83 (0.80, 0.87)] while higher risks of all-cause mortality were seen for higher intakes of naturally occurring animal-sourced nitrate [1.09 (1.04, 1.14)], additive permitted meat-sourced nitrate [1.19 (1.14, 1.25)], and tap water-sourced nitrate [1.19 (1.14, 1.25)]. Similar source-dependent associations were seen for nitrite and for CVD-related and cancer-related mortality except that naturally occurring animal-sourced nitrate and tap water-sourced nitrate were not associated with cancer-related mortality and additive permitted meat-sourced nitrate was not associated with CVD-related mortality. No clear patterns emerged in stratified analyses. CONCLUSION: Nitrate/nitrite from plant sources are inversely associated while those from naturally occurring animal-sources, additive-permitted meat sources, and tap water-sources are positively associated with mortality.

2.
Front Nutr ; 11: 1326991, 2024.
Article in English | MEDLINE | ID: mdl-38476601

ABSTRACT

Background: The dietary source and intake levels of nitrate and nitrite may govern its deleterious versus beneficial effects on human health. Existing evidence on detailed source-specific intake is limited. The objectives of this study were to assess nitrate and nitrite intakes from different dietary sources (plant-based foods, animal-based foods, and water), characterize the background diets of participants with low and high intakes, and investigate how sociodemographic and lifestyle factors associate with intake levels. Methods: In the Danish Diet, Cancer and Health Cohort, sociodemographic and lifestyle information was obtained from participants at enrolment (1993-1997). Source-dependent nitrate and nitrite intakes were calculated using comprehensive food composition databases, with tap water nitrate intakes estimated via the national drinking water quality monitoring database linked with participants' residential addresses from 1978 to 2016. Underlying dietary patterns were examined using radar plots comparing high to low consumers while sociodemographic predictors of source-dependent nitrate intakes were investigated using linear regression models. Results: In a Danish cohort of 55,754 participants aged 50-65 at enrolment, the median [IQR] intakes of dietary nitrate and nitrite were 58.13 [44.27-74.90] mg/d and 1.79 [1.43-2.21] mg/d, respectively. Plant-based foods accounted for ~76% of nitrate intake, animal-based foods ~10%, and water ~5%. Nitrite intake was sourced roughly equally from plants and animals. Higher plant-sourced nitrate intake was associated with healthier lifestyles, better dietary patterns, more physical activity, higher education, lower age and lower BMI. Females and participants who had never smoked also had significantly higher plant-sourced nitrate intakes. Higher water-sourced nitrate intake was linked to sociodemographic risk factors (smoking, obesity, lower education). Patterns for animal-sourced nitrate were less clear. Conclusion: Participants with higher plant-sourced nitrate intakes tend to be healthier while participants with higher water-sourced nitrate intakes tended to be unhealthier than their low consuming counterparts. Future research in this cohort should account for the sociodemographic and dietary predictors of source-specific nitrate intake we have identified.

3.
Phys Chem Chem Phys ; 25(4): 3457-3471, 2023 Jan 27.
Article in English | MEDLINE | ID: mdl-36637049

ABSTRACT

CO2 reduction in Solid Oxide Electrolysis Cells (SOECs) is a key-technology for the transition to a sustainable energy infrastructure and chemical industry. Ceria (CeO2) holds great promise in developing highly efficient, cost-effective and durable fuel electrodes, due to its promising electrocatalytic properties, and proven ability to suppress carbon deposition and to tolerate high concentrations of impurities. In the present work, we investigate the intrinsic electrocatalytic activity of ceria towards CO2 reduction by means of electrochemical impedance spectroscopy (EIS) on model systems with well-defined geometry, composition and surface area. Aiming at the optimization of the intrinsic catalytic properties of the material, we systematically study the effect of different dopants (Zr, Gd, Pr and Bi) on the reaction rate under varying operating conditions (temperature, gas composition and applied polarization) relevant for SOECs. The electrochemical measurements reveal the dominant role of the surface defect chemistry of the material in the reaction rate, with doping having only a mild effect on the rate and activation energy of the reaction. By analyzing the pO2 and overpotential dependence of the reaction rate with a general micro-kinetic model, we are able to identify the second electron transfer as the rate limiting step of the process, highlighting the dominant role of surface polarons in the energy landscape. These insights on the correlation between the surface defects and the electrocatalytic activity of ceria open new directions for the development of highly performing ceria-based technological electrodes.

4.
Environ Res ; 220: 115179, 2023 03 01.
Article in English | MEDLINE | ID: mdl-36584852

ABSTRACT

BACKGROUND: Air pollution is a well-recognized risk factor for cardiovascular disease. However, the mechanistic pathways underlying the association are not completely understood. Hence, further studies are required to shed light on potential mechanisms, through which air pollution may affect the development from subclinical to clinical cardiovascular disease. OBJECTIVES: To investigate associations between short-term exposure to air pollution and high-density lipoprotein (HDL), non-high density lipoprotein (non-HDL), systolic and diastolic blood pressure. METHODS: The study was conducted among 32,851 Danes from the Diet, Cancer and Health - Next Generations cohort, who had a blood sample taken and blood pressure measured. We measured HDL and non-HDL in the blood samples. We modelled exposure to fine particulate matter (PM2.5), ultrafine particles (UFP), elemental carbon (EC) and nitrogen dioxide (NO2) in time-windows from 24 h up to 90 days before blood sampling. Pollutants were modelled as total air pollution from all sources, and apportioned into contributions from non-traffic and traffic sources. We analyzed data using linear and logistic regression, with adjustment for socio-economic and lifestyle factors. RESULTS: Air pollution exposure over 24 h to 30 days was generally adversely associated with lipid profile and blood pressure, e.g. for 30-day UFP-exposure, adjusted ß-estimates were: -0.025 (-0.043; -0.006) for HDL, 0.086 (0.042; 0.130) for non-HDL, 2.45 (1.70; 3.11) for systolic and 1.56 (1.07; 20.4) for diastolic blood pressure, per 10,000 particles/cm3. The strongest associations were found for the non-traffic components of air pollution, and among those who were overweight/obese. DISCUSSION: In this large study of air pollution and lipid levels and blood pressure, we found that 24-h to 30-day PM2.5, UFP, EC and NO2 concentrations were generally adversely associated with lipid profile and blood pressure, two important cardiovascular risk factors. The study suggests potential pathways, through which air pollution could affect the development of cardiovascular disease.


Subject(s)
Air Pollutants , Air Pollution , Cardiovascular Diseases , Humans , Adult , Air Pollutants/toxicity , Air Pollutants/analysis , Nitrogen Dioxide/toxicity , Nitrogen Dioxide/analysis , Blood Pressure , Cardiovascular Diseases/chemically induced , Air Pollution/adverse effects , Air Pollution/analysis , Particulate Matter/toxicity , Particulate Matter/analysis , Lipids , Environmental Exposure
5.
BMJ Open ; 12(12): e064035, 2022 12 05.
Article in English | MEDLINE | ID: mdl-36576183

ABSTRACT

OBJECTIVES: Investigating the agreement between an expert-rated mini job exposure matrix (JEM) of lower body exposures and technical measurements of worktime spent standing/walking and observation-based estimates of time spent kneeling/squatting and total load lifted per workday. METHODS: We chose 16 job titles from the 121 job groups in the lower body JEM and included them in the mini JEM. New expert ratings for the mini JEM were performed by the same five occupational physicians who performed the ratings for the lower body JEM. For each job title and type of exposure, the exposure estimates were a mean of the five independent ratings. Technical measurements of standing/walking for all 16 job titles, and for 8 job titles workplace observations were performed of kneeling/squatting and total load lifted per workday. Data were collected from September to December 2015 and supplemented by data from the NOMAD and DPhacto studies collected between 2011 and 2013. All data were collected in Denmark. Agreement between expert-based and measured/observed lower body exposures by job titles was evaluated using Spearman's rank correlation, Bland-Altman plots evaluated systematic deviations and limits of agreement (LoA). RESULTS: Standing/walking showed a rank correlation of 0.55, kneeling/squatting 0.83 and total load lifted per workday 0.71. The mini JEM estimates did not systematically deviate from the technical measurements/observations for time spent standing/walking (mean difference 0.20 hours/workday, LoA -1.63, 2.03 hours/workday) and kneeling/squatting (mean difference -0.35 hours/workday, LoA -1.21, 0.51 hours/workday). For total load lifted per workday, the mini JEM systematically overestimated the exposures compared with the observations (mean difference -909 kg/workday, LoA -3000, 1147 kg/workday). CONCLUSIONS: There was moderate to very high agreement between an expert-rated mini JEM of standing/walking, kneeling/squatting, and lifting exposures and corresponding technical measurements/observations. This method comparison study supports the use of the expert-based lower body JEM in large-scale occupational epidemiological studies.


Subject(s)
Occupational Exposure , Humans , Workplace , Posture , Standing Position , Working Conditions
6.
Nat Commun ; 13(1): 1263, 2022 Mar 10.
Article in English | MEDLINE | ID: mdl-35273172

ABSTRACT

The transportation sector is undergoing a technology shift from internal combustion engines to electric motors powered by secondary Li-based batteries. However, the limited range and long charging times of Li-ion batteries still hinder widespread adoption. This aspect is particularly true in the case of heavy freight and long-range transportation, where solid oxide fuel cells (SOFCs) offer an attractive alternative as they can provide high-efficiency and flexible fuel choices. However, the SOFC technology is mainly used for stationary applications owing to the high operating temperature, low volumetric power density and specific power, and poor robustness towards thermal cycling and mechanical vibrations of conventional ceramic-based cells. Here, we present a metal-based monolithic fuel cell design to overcome these issues. Cost-effective and scalable manufacturing processes are employed for fabrication, and only a single heat treatment is required, as opposed to multiple thermal treatments in conventional SOFC production. The design is optimised through three-dimensional multiphysics modelling, nanoparticle infiltration, and corrosion-mitigating treatments. The monolithic fuel cell stack shows a power density of 5.6 kW/L, thus, demonstrating the potential of SOFC technology for transport applications.

7.
BMC Musculoskelet Disord ; 22(1): 170, 2021 Feb 11.
Article in English | MEDLINE | ID: mdl-33573624

ABSTRACT

BACKGROUND: Altered knee muscle activity in children with asymptomatic Generalized Joint Hypermobility (GJH) is reported during isometric contraction, static and dynamic balance tasks and jumping, but has not been studied during gait. Therefore, the aim was to investigate group differences in knee muscle activity simultaneously with knee joint kinematics during treadmill walking between children with and without GJH. METHODS: Girls 14-15 years of age with GJH (inclusion criteria: Beighton score ≥6 of 9 and positive hyperextension ≥10° (one/both knees)) and a matched control group without GJH (inclusion criteria: Beighton score ≤5 and no knee hyperextension ≥10° ) were recruited. In total 16 participants with GJH and 10 non-GJH participants were included in the study. Surface electromyography (sEMG) was measured from the quadriceps, hamstrings and gastrocnemius muscles of the dominant leg during treadmill walking. Maximal voluntary isometric contractions while sitting were used for normalisation of sEMG to % of Maximum Voluntary EMG (%MVE). Knee joint angles during treadmill walking were measured by electrogoniometer. Furthermore, co-contraction index (CCI) was calculated, and presented for muscle groups of hamstrings-quadriceps (HQ) and gastrocnemius-quadriceps (GQ). CCI of medial and lateral sides of the knee, including ratio of the medial and lateral CCI for HQ and GQ were calculated. RESULTS: No group differences were found in demographics, muscle activation level, nor CCI and CCI ratios. However, participants with GJH displayed significantly decreased knee joint angle, mean (153º vs. 156º; p =0.03) and minimum (105º vs. 111º; p=0.01), during treadmill walking compared with controls. CONCLUSION: Muscle activity during gait was not different between participants with GJH and non-GJH participants. However, participants with GJH displayed minor but statistically significant increased knee flexion during gait. Since the clinical consequences of increased knee joint flexion during gait are unknown, future studies should follow a larger cohort longitudinally during overground walking for development of clinical complications in this group.


Subject(s)
Joint Instability , Adolescent , Biomechanical Phenomena , Child , Electromyography , Female , Gait , Humans , Joint Instability/diagnosis , Knee , Knee Joint , Muscle, Skeletal , Walking
8.
Phys Chem Chem Phys ; 22(27): 15418-15426, 2020 Jul 21.
Article in English | MEDLINE | ID: mdl-32601629

ABSTRACT

The oxygen exchange activity of thin dense La0.6Sr0.4FeO3 electrodes prepared by pulsed laser deposition was investigated by electrochemical impedance spectroscopy and electrical conductivity relaxation below 600 °C. The value of the surface exchange coefficient (kchem) measured at 491 °C decreased from an initial 4.4 × 10-6 cm s-1 to 1.7 × 10-7 cm s-1 after aging for 7 days. The rapid decrease in the oxygen exchange rate was accompanied by the increase in the surface concentration of 'non-lattice strontium' detected by X-ray photoelectron spectroscopy. Subsequent electrochemical tests over 40 days showed that the electrode performance could be recovered by rinsing the passivated electrode in deionized water. Repeated treatments eventually also led to improved stability of electrochemical performance.

9.
Ann Work Expo Health ; 64(6): 586-595, 2020 07 01.
Article in English | MEDLINE | ID: mdl-32490511

ABSTRACT

OBJECTIVES: Childcare workers in Denmark have high prevalence of musculoskeletal pain (MSP) and sickness absence, but the existing knowledge of their physical work demands is limited, hampering preventive initiatives. This study aimed to assess the physical work demands with accelerometers and workplace observations of childcare workers handling children age 0-3. METHODS: Data collection consisted of an electronic survey, anthropometric measurements, accelerometer measurements providing information of physical activity types and postures with Acti4 software from five consecutive workdays, as well as 4-h visual workplace observation per childcare worker from 16 Danish nurseries. RESULTS: In total, 199 childcare workers were enrolled in the study. A total of 4181 working hours of accelerometer measurements and 722 h of workplace observations were carried out. Accelerometer measurements showed that they spent about half of the working day (44.8%) in sedentary postures, and the rest standing (22.8%), moving (13.0%), walking (14.6%), running (0.1%), and climbing stairs (0.7%), with 4.1% in knee straining postures (kneeling and squatting) and 4.3% forward trunk inclination >60°. Workplace observations showed that they carried children 1.8% of the working hours. CONCLUSIONS: Physical work demands of Danish childcare workers are characterized by about half of the workday being sedentary, and the remaining of the workday being quite evenly distributed between standing and dynamic activities, with low exposures to carrying children. Their exposure to forward bending of the trunk and knee straining postures could impose a risk for MSP and sickness absence, and preventive initiatives should be considered.


Subject(s)
Nurseries, Infant , Child, Preschool , Denmark , Humans , Infant , Infant, Newborn , Occupational Exposure , Posture , Workplace
10.
Scand J Med Sci Sports ; 30(10): 1966-1975, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32516858

ABSTRACT

AIM: The aim of this study was to compare the association between count- and activity type-based definitions of light-intensity physical activity (LIPA) and adiposity markers. METHODS: A total of 516 Danish workers participated in 1-4 days of hip- and thigh-based accelerometer measurements. Three definitions of average daily time spent in LIPA were derived: LIPA (1) time spent between 100 and 2029 CPM, LIPA (2) time spent moving and slow walking, and LIPA (3) time spent moving, walking slow, and standing. Adiposity markers were body mass index (BMI), body fat percentage, and waist circumference. The cross-sectional association between the three LIPA definitions and adiposity markers was analyzed and interpreted using compositional regression models followed by reallocation of time between LIPA, moderate-to-vigorous physical activity (MVPA), and sedentary behavior (SB), respectively. RESULTS: The geometric means of daily time (min/day) spent in LIPA 1, LIPA 2, and LIPA 3 were 326, 102, and 274, respectively. We found the direction and strength of the association between the relative importance of daily time spent in LIPA and the adiposity markers to depend on the LIPA definition. For example, reallocating 30 minutes from MVPA to LIPA 1, LIPA 2 and LIPA 3 were associated with a 2.97 (95% CI: 0.68; 5.27), -0.71 (95% CI: -1.43; 0.02), and -0.45 (95% CI: -1.01; 0.11) difference in BMI, respectively. CONCLUSION: Our findings highlight the need for caution when comparing results from studies using different definitions of LIPA.


Subject(s)
Adiposity , Body Mass Index , Exercise , Sedentary Behavior , Waist Circumference , Accelerometry , Adipose Tissue/anatomy & histology , Cohort Studies , Cross-Sectional Studies , Denmark , Female , Humans , Locomotion , Male , Middle Aged , Regression Analysis , Standing Position , Time Factors , Walking Speed
11.
Article in English | MEDLINE | ID: mdl-32131510

ABSTRACT

The aim of this study is to evaluate the inter-rater reliability of a newly developed instrument-TRACK (observaTion woRk demAnds Childcare worK) for observations of ergonomic work demands in childcare work. Two trained raters conducted thirty hours of concurrent observation of fifteen childcare workers in three different day nurseries. Inter-rater reliability of ergonomic work demands was evaluated using Gwet's Agreement Coefficient (AC1) and interpreted by the Landis and Koch benchmark scale. Twenty ergonomic work demand items were evaluated. Inter-rater reliability was 'almost perfect' for nine items (AC1 0.81-1.00), 'substantial' for four items (AC1 0.61-0.80), 'moderate' for four items (AC1 0.41-0.60), 'fair' for two items (AC1 0.21-0.40), and 'slight' (AC1 0.00-0.20) for one item. No items had 'poor' (AC1 < 0.00) agreement. The instrument is reliable for assessing ergonomic work demands in childcare in real-life settings.


Subject(s)
Child Care , Evaluation Studies as Topic , Adult , Caregivers/statistics & numerical data , Child , Ergonomics , Humans , Reproducibility of Results
12.
Toxicol In Vitro ; 65: 104824, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32165152

ABSTRACT

Soybean toxin (SBTX) is a protein isolated from soybean seeds and composed of two polypeptide subunits (17 and 27 kDa). SBTX has in vitro activity against phytopathogenic fungi such as Cercospora sojina, Aspergillus niger, and Penicillium herguei, and yeasts like Candida albicans, C. parapsilosis, Kluyveromyces marxiannus, and Pichia membranifaciens. The present study aimed to analyze in vitro whether SBTX causes any side effects on non-target bacterial and mammalian cells that could impede its potential use as a novel antifungal agent. SBTX at 100 µg/mL and 200 µg/mL did not hinder the growth of the bacteria Salmonella enterica (subspecies enterica serovar choleraesuis), Bacillus subtilis (subspecies spizizenii) and Staphylococcus aureus. Moreover, SBTX at concentrations up to 500 µg/mL did not significantly affect the viability of erythrocytes, neutrophils, and human intestinal Caco-2 cells. To study whether SBTX could induce relevant alterations in gene expression, in vitro DNA microarray experiments were conducted in which differentiated Caco-2 cells were exposed for 24 h to 100 µg/mL or 200 µg/mL SBTX. SBTX up-regulated genes involved in cell cycle and immune response pathways, but down-regulated genes that play a role in cholesterol biosynthesis and platelet degranulation pathways. Thus, although SBTX did not affect bacteria, nor induced cytotoxity in mammalian cells, it affected some biological pathways in the human Caco-2 cell line that warrants further investigation.


Subject(s)
Antifungal Agents/pharmacology , Glycoproteins/pharmacology , Soybean Proteins/pharmacology , Animals , Bacteria/drug effects , Bacteria/growth & development , Cell Survival/drug effects , Cells, Cultured , Erythrocytes/drug effects , Humans , Mice , Microbial Sensitivity Tests , Neutrophils/drug effects , Oligonucleotide Array Sequence Analysis , Transcriptome/drug effects
13.
Ergonomics ; 63(5): 607-617, 2020 May.
Article in English | MEDLINE | ID: mdl-32100646

ABSTRACT

Occupational kneeling and squatting are well-documented risk factors for knee disorders. A method using 3 wireless accelerometers to detect and discriminate kneeling and squatting during work were developed based on data from a semi-standardised laboratory protocol. The method was tested for validity under free-living working conditions. The developed method showed high sensitivity (88-99%) and specificity (98-99%) for detection of kneeling and squatting during the semi-standardised laboratory conditions. During free-living working conditions, kneeling showed very high sensitivity (94%) and specificity (99%), while squatting results were non-conclusive due to limited duration of squatting during the free-living working conditions. This method shows great promise for long-term technical measurement of kneeling and squatting during normal working conditions using wireless accelerometers. The method opens up possibilities for using technical measurements to provide valid exposure assessments and intervention evaluations of kneeling and squatting, as well as increased feasibility for technical measurements in large cohort studies. Practitioner summary: Quantification of kneeling and squatting during work is important for prevention, but limited by either imprecise or costly methods. This study developed and validated an inexpensive wireless accelerometer-based measurement method that can be used by practitioners and researchers for long-term measurements of kneeling and squatting during free-living working conditions.


Subject(s)
Accelerometry/instrumentation , Knee Joint/physiology , Posture , Workload , Adult , Female , Humans , Male , Occupational Diseases/prevention & control , Occupational Exposure/prevention & control , Reproducibility of Results , Wireless Technology
14.
ACS Appl Mater Interfaces ; 11(29): 25996-26004, 2019 Jul 24.
Article in English | MEDLINE | ID: mdl-31242388

ABSTRACT

Despite various advantages of high-temperature solid oxide electrolysis cells (SOECs) over their low-temperature competitors, the insufficient long-term durability has prevented the commercialization of SOECs. Here, we address this challenge by employing two nanoengineered electrodes. The O2 electrode consists of a La0.6Sr0.4CoO3-δ (LSC) and Gd,Pr-co-doped CeO2 (CGPO) nanocomposite coating deposited on a Gd-doped CeO2 (CGO) scaffold, and the H2 electrode comprises a Ni/yttria stabilized zirconia (YSZ) electrode modified with a nanogranular CGO coating. The resulting cell with an active area of 4 × 4 cm2 exhibits a current density exceeding 1.2 A cm-2 at 1.3 V and 750 °C for steam electrolysis while also offering excellent long-term durability at 1 A cm-2 with a high steam-to-hydrogen conversion of ∼56%. We further unravel the degradation mechanism of the most commonly used Ni/YSZ electrode under these conditions and describe the mitigation of the discussed mechanism on our nanoengineered electrode. Our findings demonstrate the potential of designing robust SOECs by nanoengineering electrodes through infiltration and have significant implications for the practical integration of SOEC technology in the future sustainable energy system.

15.
ALTEX ; 36(2): 203-214, 2019.
Article in English | MEDLINE | ID: mdl-30462829

ABSTRACT

The mouse bioassay for the detection of marine biotoxins in shellfish products is 40 years old and still in use. A full ban or total replacement of this in vivo test has been postponed because of the fear that current chemical-based detection methods could miss a new emerging toxin. In order to fully replace the mouse bioassay, more efforts are needed on the search for functional assays with specific endpoints. Gene expression elicited by diarrheic shellfish poisons in Caco-2 cells allowed us to determine three 'DSP profiles', i.e. OA/DTX, AZA-YTX and PTX profiles. Twelve marker genes were selected to envision the three profiles. qRT-PCR is relatively cheap and easy, and although its multiplex capacity is limited to 5 genes, this turned out to be sufficient to show the three expected profiles. The use of the multiplex magnetic bead-based assay turned out to be even a slightly better alternative, allowing the use of all twelve selected marker genes and 2 reference genes, and resulting in clear profiles with for some genes even higher induction factors as obtained by qRT-PCR. When analysing blank and contaminated shellfish samples with this multiplex magnetic bead-based assay, the contaminated samples could easily be distinguished from the blank samples, showing the expected profiles. This work is one step further on the final replacement of the mouse bioassay, e.g. by combining the neuro-2a bioassay for screening and detection with analytical chemical analyses and the multiplex magnetic bead-based assay for confirmation of known and unknown toxins respectively.


Subject(s)
Biological Assay , Caco-2 Cells , Diarrhea/chemically induced , Marine Toxins , Polymerase Chain Reaction/methods , RNA, Messenger/genetics , Shellfish Poisoning , Animals , Humans , Marine Toxins/analysis , Marine Toxins/toxicity , Mice , Okadaic Acid/toxicity
16.
Mar Drugs ; 16(12)2018 Dec 12.
Article in English | MEDLINE | ID: mdl-30545061

ABSTRACT

Marine biotoxins in fish and shellfish can cause several symptoms in consumers, such as diarrhea, amnesia, or even death by paralysis. Monitoring programs are in place for testing shellfish on a regular basis. In some countries testing is performed using the so-called mouse bioassay, an assay that faces ethical concerns not only because of animal distress, but also because it lacks specificity and results in high amounts of false positives. In Europe, for lipophilic marine biotoxins (LMBs), a chemical analytical method using LC-MS/MS was developed as an alternative and is now the reference method. However, safety is often questioned when relying solely on such a method, and as a result, the mouse bioassay might still be used. In this study the use of a cell-based assay for screening, i.e., the neuro-2a assay, in combination with the official LC-MS/MS method was investigated as a new alternative strategy for the detection and quantification of LMBs. To this end, samples that had been tested previously with the mouse bioassay were analyzed in the neuro-2a bioassay and the LC-MS/MS method. The neuro-2a bioassay was able to detect all LMBs at the regulatory levels and all samples that tested positive in the mouse bioassay were also suspect in the neuro-2a bioassay. In most cases, these samples contained toxin levels (yessotoxins) that explain the outcome of the bioassay but did not exceed the established maximum permitted levels.


Subject(s)
Animal Testing Alternatives/methods , Biological Assay/methods , Marine Toxins/analysis , Shellfish Poisoning/prevention & control , Shellfish/analysis , Animal Testing Alternatives/instrumentation , Animals , Biological Assay/instrumentation , Bivalvia , Cell Line, Tumor , Chromatography, High Pressure Liquid/instrumentation , Chromatography, High Pressure Liquid/methods , False Positive Reactions , Marine Toxins/toxicity , Mice , Mollusk Venoms , Oxocins/analysis , Oxocins/toxicity , Shellfish/toxicity , Shellfish Poisoning/etiology , Tandem Mass Spectrometry/instrumentation , Tandem Mass Spectrometry/methods
17.
Trials ; 19(1): 411, 2018 Jul 31.
Article in English | MEDLINE | ID: mdl-30064464

ABSTRACT

BACKGROUND: The prevalence of musculoskeletal pain (MSP) is persistently high throughout the world. Work-related factors such as high physical workload (lifting, bending and twisting of the back) are considered to be among the main causes of MSP. Work in childcare includes the need to lift, carry, and support children in a range of activities, requiring several demanding postures and movements, such as bending forward and twisting of the back and sitting on the floor. Participatory ergonomics may represent a solution for decreasing the physical workload to reduce MSP. We present the protocol of a study aiming to evaluate the effect and process of a participatory ergonomics intervention designed to reduce physical exertion during work and MSP (including MSP interfering with work) among childcare workers. METHODS/DESIGN: This study will use a two-arm cluster-randomized design employing a wait-list control, with childcare institutions forming the clusters. Three workshops will be conducted during the 4-month intervention period. Participants will identify risk factors for strenuous work and MSP, develop solutions for reducing the identified risk factors, and implement them in their team. An ergonomic consultant will guide the process. The data collection will consist of questionnaires and objective measures of heart rate and physical activity, observations of physical workload, and information on sickness absence based on company records. Primary outcomes are physical exertion during work and MSP (including pain-related work interference) measured at 4 months. Secondary outcomes measured at 4 months are sickness absence due to MSP; objectively measured occupational physical activity and heart rate; and self-reported self-efficacy, employee involvement, and need for recovery. Alongside the trial, a process evaluation and an economic evaluation will be conducted. DISCUSSION: The study will evaluate the effect and process of a participatory ergonomics intervention to reduce physical exertion at work and MSP among childcare workers. By performing a cluster-randomized controlled trial with an effect evaluation based on both objective and self-reported measures with the addition of a process evaluation and economic evaluation, this study will contribute to the evidence for prevention of MSP among a less studied occupational group. Results are expected in 2018-2019. TRIAL REGISTRATION: ISRCTN, ISRCTN10928313 . Registered on 11 January 2017.


Subject(s)
Child Care , Ergonomics/methods , Musculoskeletal Pain/prevention & control , Occupational Diseases/prevention & control , Occupations , Physical Exertion , Absenteeism , Child, Preschool , Denmark , Female , Humans , Infant , Infant, Newborn , Job Description , Male , Multicenter Studies as Topic , Musculoskeletal Pain/diagnosis , Musculoskeletal Pain/etiology , Musculoskeletal Pain/physiopathology , Occupational Diseases/diagnosis , Occupational Diseases/etiology , Occupational Diseases/physiopathology , Pain Measurement , Protective Factors , Randomized Controlled Trials as Topic , Risk Factors , Sick Leave , Time Factors , Workplace
18.
Article in English | MEDLINE | ID: mdl-28884655

ABSTRACT

The neuro-2a bioassay is considered as one of the most promising cell-based in vitro bioassays for the broad screening of seafood products for the presence of marine biotoxins. The neuro-2a assay has been shown to detect a wide array of toxins like paralytic shellfish poisons (PSPs), ciguatoxins, and also lipophilic marine biotoxins (LMBs). However, the neuro-2a assay is rarely used for routine testing of samples due to matrix effects that, for example, lead to false positives when testing for LMBs. As a result there are only limited data on validation and evaluation of its performance on real samples. In the present study, the standard extraction procedure for LMBs was adjusted by introducing an additional clean-up step with n-hexane. Recovery losses due to this extra step were less than 10%. This wash step was a crucial addition in order to eliminate false-positive outcomes due to matrix effects. Next, the applicability of this assay was assessed by testing a broad range of shellfish samples contaminated with various LMBs, including diarrhetic shellfish toxins/poisons (DSPs). For comparison, the samples were also analysed by LC-MS/MS. Standards of all regulated LMBs were tested, including analogues of some of these toxins. The neuro-2a cells showed good sensitivity towards all compounds. Extracts of 87 samples, both blank and contaminated with various toxins, were tested. The neuro-2a outcomes were in line with those of LC-MS/MS analysis and support the applicability of this assay for the screening of samples for LMBs. However, for use in a daily routine setting, the test might be further improved and we discuss several recommended modifications which should be considered before a full validation is carried out.


Subject(s)
Biological Assay , Marine Toxins/analysis , Shellfish/analysis , Tetrazolium Salts/chemistry , Thiazoles/chemistry , Animals , Mice , Tumor Cells, Cultured
19.
Toxicol In Vitro ; 46: 102-112, 2018 Feb.
Article in English | MEDLINE | ID: mdl-28939011

ABSTRACT

A study with DNA microarrays was performed to investigate the effects of two diarrhetic and one azaspiracid shellfish poison, okadaic acid (OA), dinophysistoxin-1 (DTX-1) and azaspiracid-1 (AZA-1) respectively, on the whole-genome mRNA expression of undifferentiated intestinal Caco-2 cells. Previously, the most responding genes were used to develop a dedicated array tube test to screen shellfish samples on the presence of these toxins. In the present study the whole genome mRNA expression was analyzed in order to reveal modes of action and obtain hints on potential biomarkers suitable to be used in alternative bioassays. Effects on key genes in the most affected pathways and processes were confirmed by qPCR. OA and DTX-1 induced almost identical effects on mRNA expression, which strongly indicates that OA and DTX-1induce similar toxic effects. Biological interpretation of the microarray data indicates that both compounds induce hypoxia related pathways/processes, the unfolded protein response (UPR) and endoplasmic reticulum (ER) stress. The gene expression profile of AZA-1 is different and shows increased mRNA expression of genes involved in cholesterol synthesis and glycolysis, suggesting a different mode of action for this toxin. Future studies should reveal whether identified pathways provide suitable biomarkers for rapid detection of DSPs in shellfish.


Subject(s)
Gene Expression Profiling/methods , Genome , Marine Toxins/toxicity , Okadaic Acid/toxicity , Pyrans/toxicity , RNA, Messenger/genetics , Spiro Compounds/toxicity , Caco-2 Cells , Cell Survival/drug effects , Gene Expression Regulation/drug effects , Humans
20.
Appl Ergon ; 63: 41-52, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28502405

ABSTRACT

Sedentary behavior is defined as sitting or lying with low energy expenditure. Humans in industrialized societies spend an increasing amount of time in sedentary behaviors every day. This has been associated with detrimental health outcomes. Despite a growing interest in the health effects of sedentary behavior at work, associations remain unclear, plausibly due to poor and diverse methods for assessing sedentary behavior. Thus, good practice guidance for researchers and practitioners on how to assess occupational sedentary behavior are needed. The aim of this paper is to provide a practical guidance for practitioners and researchers on how to assess occupational sedentary behavior. Ambulatory systems for use in field applications (wearables) are a promising approach for sedentary behavior assessment. Many different small-size consumer wearables, with long battery life and high data storage capacity are commercially available today. However, no stand-alone commercial system is able to assess sedentary behavior in accordance with its definition. The present paper offers decision support for practitioners and researchers in selecting wearables and data collection strategies for their purpose of study on sedentary behavior. Valid and reliable assessment of occupational sedentary behavior is currently not easy. Several aspects need to be considered in the decision process on how to assess sedentary behavior. There is a need for development of a cheap and easily useable wearable for assessment of occupational sedentary behavior by researchers and practitioners.


Subject(s)
Health Behavior , Occupational Health/standards , Practice Guidelines as Topic/standards , Risk Assessment/standards , Sedentary Behavior , Humans , Risk Assessment/methods , Workplace/psychology
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