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Document Server@UHasselt (59.068 recursos)

Repository of the University of Hasselt containing publications in the fields of statistics, computer science, information strategies and material from the Institute for behavioural sciences.

Environmental Biology

Mostrando recursos 1 - 20 de 205

  1. Carbon loading in airway macrophages as a biomarker for individual exposure to particulate matter air pollution - A critical review

    Bai, Yang; Brugha, Rossa E.; Jacobs, Lotte; Grigg, Jonathan; NAWROT, Tim; Nemery, Benoit
    Exposure to particulate matter (PM) is associated with adverse health effects, including chronic lung diseases, lung cancer and cardiovascular disease. Personal exposure varies depending on the generation of particles locally, background levels, activity patterns and meteorology. Carbon loading in airway macrophages (AM) is a novel marker to assess personal exposure to combustion-derived particles. This review summarizes the published evidence and describes the validity and reliability of this marker with a focus on the technical aspects. Carbon loading in AM is reported in nine published studies assessing personal exposure to particulate air pollution. The carbon content is quantified by image analysis...

  2. Blood Pressure in Relation to Environmental Lead Exposure in the National Health and Nutrition Examination Survey 2003 to 2010

    Hara, Azusa; Thijs, Lutgarde; Asayama, Kei; Gu, Yu-Mei; Jacobs, Lotte; Zhang, Zhen-Yu; Liu, Yan-Ping; NAWROT, Tim; Staessen, Jan A.
    In view of the declining environmental lead exposure in the United States, we analyzed the National Health and Nutrition Examination Survey (2003-2010) for association of blood pressure and hypertension with blood lead. The 12 725 participants included 21.1% blacks, 20.5% Hispanics, 58.4% whites, and 48.7% women. Blacks compared with non-Blacks had higher systolic and diastolic pressures (126.5 versus 123.9 and 71.9 versus 69.6 mm Hg) and higher hypertension prevalence (44.7 versus 36.8%). Blood lead was lower in whites than in non-whites (1.46 versus 1.57 mu g/dL) and in women than in men (1.25 versus 1.80 mu g/dL). In multivariable analyses...

  3. Renal cells exposed to cadmium in vitro and in vivo: normalizing gene expression data

    RAVINDRAN NAIR, Ambily; SMEETS, Karen; KEUNEN, Els; Lee, Wing-Kee; Thévenod, Frank; VAN KERKHOVE, Emmy; CUYPERS, Ann
    Cadmium (Cd) is a toxic metal with a long half-life in biological systems. This half-life is partly as a result of metallothioneins (MTs), metal-binding proteins with a high affinity for Cd. The high retention properties of the kidneys reside in proximal tubular cells that possess transport mechanisms for Cd-MT uptake, ultimately leading to more Cd accumulation. Researchers have studied MT–metal interactions using various techniques including quantitative real-time PCR (qPCR), an efficient tool for quantifying gene expression. Often a poor choice of reference genes, which is represented by their instability and condition dependency, leads to inefficient normalization of gene expression data...

  4. Glutathione and mitochondria determine acute defense responses and adaptive processes in cadmium-induced oxidative stress and toxicity of the kidney

    Ravindran Nair, Ambily; Lee, Wing-Kee; Smeets, Karen; Swennen, Quirine; Sanchez, Amparo; Thévenod, Frank; Cuypers, Ann
    Cadmium (Cd2+) induces oxidative stress that ultimately defines cell fate and pathology. Mitochondria are the main energy-producing organelles in mammalian cells, but they also have a central role in formation of reactive oxygen species, cell injury, and death signaling. As the kidney is the major target in Cd2+ toxicity, the roles of oxidative signature and mitochondrial function and biogenesis in Cd2+-related stress outcomes were investigated in vitro in cultured rat kidney proximal tubule cells (PTCs) (WKPT-0293 Cl.2) for acute Cd2+ toxicity (1–30 µM, 24 h) and in vivo in Fischer 344 rats for sub-chronic Cd2+ toxicity (1 mg/kg CdCl2 subcutaneously,...

  5. Reliable gene expression analysis by reverse transcription-quantitative PCR: reporting and minimizing the uncertainty in data accuracy.

    REMANS, Tony; KEUNEN, Els; BEX, Geert Jan; SMEETS, Karen; VANGRONSVELD, Jaco; CUYPERS, Ann
    Reverse transcription-quantitative PCR (RT-qPCR) has been widely adopted to measure differences in mRNA levels; however, biological and technical variation strongly affects the accuracy of the reported differences. RT-qPCR specialists have warned that, unless researchers minimize this variability, they may report inaccurate differences and draw incorrect biological conclusions. The Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines describe procedures for conducting and reporting RT-qPCR experiments. The MIQE guidelines enable others to judge the reliability of reported results; however, a recent literature survey found low adherence to these guidelines. Additionally, even experiments that use appropriate procedures remain subject to individual variation...

  6. Wild Flora of Mine Tailings: Perspectives for Use in Phytoremediation of Potentially Toxic Elements in a Semi-Arid Region in Mexico

    Sanchez-Lopez, Ariadna S.; Gonzalez-Chavez, Ma. Del Carmen A.; Carrillo-Gonzalez, Rogelio; VANGRONSVELD, Jaco; Diaz-Garduno, Margarita
    The aim of this research was to identify wild plant species applicable for remediation of mine tailings in arid soils. Plants growing on two mine tailings were identified and evaluated for their potential use in phytoremediation based on the concentration of potentially toxic elements (PTEs) in roots and shoots, bioconcentration (BCF) and translocation factors (TF). Total, water-soluble and DTPA-extractable concentrations of Pb, Cd, Zn, Cu, Co and Ni in rhizospheric and bulk soil were determined. Twelve species can grow on mine tailings, accumulate PTEs concentrations above the commonly accepted phytotoxicity levels, and are suitable for establishing a vegetation cover on...

  7. Arabidopsis thaliana seedlings show an age-dependent response on growth and DNA repair after exposure to chronic gamma-radiation

    BIERMANS, Geert; HOREMANS, Nele; VANHOUDT, Nathalie; Vandenhove, Hildegarde; SAENEN, Eline; Van Hees, May; Wannijn, Jean; VANGRONSVELD, Jaco; CUYPERS, Ann
    The biosphere is constantly exposed to ionising radiation, due to cosmic radiation and the presence of natural and anthropogenic radionuclides in the environment. The biological effects of the resulting radiation exposure are currently poorly understood in plants, due to a large influence of parameters such as species, cultivar, experimental setup and plant age on the response. In this study, 7-, 10- and 14-day-old Arabidopsis thaliana seedlings were exposed to 96 h and 168 h of 100 mGy h(-1) chronic gamma-radiation in a hydroponic setup. The response of growth, photosynthesis and the transcription of genes involved in DNA repair, cell cycle...

  8. Exploring the rhizospheric and endophytic bacterial communities of Acer pseudoplatanus growing on a TNT-contaminated soil: towards the development of a rhizocompetent TNT-detoxifying plant growth promoting consortium

    THIJS, Sofie; Van Dillewijn, Pieter; SILLEN, Wouter; TRUYENS, Sascha; HOLTAPPELS, Michelle; D'HAEN, Jan; CARLEER, Robert; WEYENS, Nele; AMELOOT, Marcel; Ramos, Juan-Luis; VANGRONSVELD, Jaco
    Background and aims Numerous microorganisms have been isolated from trinitrotoluene (TNT)-contaminated soils, however TNT tends to persist, indicating that the microbial biomass or activity is insufficient for degradation. Deep-rooting trees at military sites have been found to take-up contaminants from groundwater, and the extensive root and endosphere provide ideal niches for microbial TNT-transformations. Methods We characterised the rhizosphere, root endosphere and endo-phyllosphere bacteria of Acer pseudoplatanus growing at a historically TNT-contaminated location, using 16S rRNA gene fingerprinting, bacteria isolation, oxidoreductase gene-cloning, in planta growth-promotion (PGP) tests, inoculation, plant physiology measurements and microscopy. Results Based on terminal-restriction-fragment-length-polymorphism analysis, bulk soil and...

  9. Soil fungi appear to have a retarding rather than a stimulating role on soil apatite weathering

    SMITS, Mark; Johansson, Leif; Wallander, Hakan
    Aims Vegetation stimulates, in general, soil mineral weathering. It has been hypothesized that plant-associated microorganisms, especially ectomycorrhizal fungi play a major role in this process. We studied apatite dissolution in a vegetation gradient in southern Norway to test the role of ectomycorrhizal vegetation on mineral weathering. Methods A natural occurring lead contamination, probably present since the last glaciation, caused a gradient from bare soil, via sparse grass to healthy spruce forest. We measured apatite content, soil solution chemistry, delta C-13, delta N-15, C, N and ergosterol content in soil profiles along the gradient. Results The apatite loss for each soil...

  10. Azithromycin and the Treatment of Lymphocytic Airway Inflammation After Lung Transplantation

    VOS, Rein; Verleden, S. E.; Ruttens, D.; Vandermeulen, E.; Bellon, H.; Neyrinck, A.; Van Raemdonck, D. E.; Yserbyt, J.; Dupont, L. J.; Verbeken, E. K.; Moelants, E.; Mortier, A.; Proost, P.; Schols, D.; Cox, B.; Verleden, G. M.; Vanaudenaerde, B. M.
    Lymphocytic airway inflammation is a major risk factor for chronic lung allograft dysfunction, for which there is no established treatment. We investigated whether azithromycin could control lymphocytic airway inflammation and improve allograft function. Fifteen lung transplant recipients demonstrating acute allograft dysfunction due to isolated lymphocytic airway inflammation were prospectively treated with azithromycin for at least 6 months (NCT01109160). Spirometry (FVC, FEV1, FEF25-75, Tiffeneau index) and FeNO were assessed before and up to 12 months after initiation of azithromycin. Radiologic features, local inflammation assessed on airway biopsy (rejection score, IL-17(+)cells/mm(2) lamina propria) and broncho-alveolar lavage fluid (total and differential cell counts,...

  11. Left ventricular diastolic function associated with common genetic variation in ATP12A in a general population

    Knez, Judita; Salvi, Erika; Tikhonoff, Valerie; Stolarz-Skrzypek, Katarzyna; Ryabikov, Andrew; Thijs, Lutgarde; Braga, Daniele; Kloch-Badelek, Malgorzata; Malyutina, Sofia; Casiglia, Edoardo; Czarnecka, Danuta; Kawecka-Jaszcz, Kalina; Cusi, Daniele; NAWROT, Tim; Staessen, Jan A.; Kuznetsova, Tatiana
    Background: Left ventricular (LV) function depends on the activity of transmembrane electrolyte transporters. Failing human myocardium has lower Na+/K+ ATPase expression and higher intracellular sodium concentrations. The ATP12A gene encodes a catalytic subunit of an ATPase that can function as a Na+/K+ pump. We, therefore, investigated the association between LV function and common genetic variants in ATP12A. Methods: A random sample of 1166 participants (53.7% women; mean age 49.5 years, 44.8% hypertensive) was recruited in Belgium, Poland, Italy and Russia. We measured transmitral early and late diastolic velocities (E and A) by pulsed wave Doppler, and mitral annular velocities (e'...

  12. Blood pressure changes in association with black carbon exposure in a panel of healthy adults are independent of retinal microcirculation.

    LOUWIES, Tijs; Nawrot, Tim; Cox, Bianca; Dons, Evi; Penders, Joris; PROVOST, Eline; Int Panis, Luc; De Boever, Patrick
    Exposure to ambient particulate matter and elevated blood pressure are risk factors for cardiovascular morbidity and mortality. Microvascular changes might be an important pathway in explaining the association between air pollution and blood pressure. The objective of the study was to evaluate the role of the retinal microcirculation in the association between black carbon (BC) exposure and blood pressure.We estimated subchronic BC exposure based on 1-week personal measurements (μAethalometer, AethLabs) in 55 healthy nurses. Blood pressure and retinal microvasculature were measured on four different days (range: 2–4) during this week.Subchronic BC exposure averaged (± SD) 1334 ± 631 ng/m3 and...

  13. DNA methylation patterns in respiratory allergy cases: comparability of saliva vs. blood

    Langie, Sabine; Traen, Sophie; DE BOEVER, Patrick; Szic, Katarzyna Szarc Vel; Declerck, Ken; Koppen, Gudrun; Schepers, Anne; Van Camp, Guy; Vanden Berghe, Wim; Schoeters, Greet

  14. Variation of DNA methylation in candidate age-related targets on the mitochondrial-telomere axis in cord blood and placenta

    Janssen, Bram; Byun, H. M.; Cox, Bianca; Gyselaers, Wilfried; Izzi, B.; Baccarelli, Andrea A.; Nawrot, Tim
    Background: Epigenetics is tissue-specific and potentially even cell-specific, but little information is available from human reproductive studies about the concordance of DNA methylation patterns in cord blood and placenta, as well as within-placenta variations. We evaluated methylation levels at promoter regions of candidate genes in biological ageing pathways (SIRT1, TP53, PPARG, PPARGC1A, and TFAM), a subtelomeric region (D4Z4) and the mitochondrial genome (MT-RNR1, D-loop). Methods: Ninety individuals were randomly chosen from the ENVIRONAGE birth cohort to evaluate methylation concordance between cord blood and placenta using highly quantitative bisulfite-PCR pyrosequencing. In a subset of nineteen individuals, a more extensive sampling scheme...

  15. Differential response of Arabidopsis leaves and roots to cadmium: Glutathione-related chelating capacity vs antioxidant capacity

    JOZEFCZAK, Marijke; KEUNEN, Els; Schat, Henk; Bliek, Mattijs; Hernandez, Luis E.; CARLEER, Robert; REMANS, Tony; BOHLER, Sacha; VANGRONSVELD, Jaco; CUYPERS, Ann
    This study aims to uncover the spatiotemporal involvement of glutathione (GSH) in two major mechanisms of cadmium (Cd)-induced detoxification (i.e. chelation and antioxidative defence). A kinetic study was conducted on hydroponically grown Arabidopsis thaliana (L Heyhn) to gain insight into the early events after exposure to Cd. Cadmium detoxification was investigated at different levels, including gene transcripts, enzyme activities and metabolite content. Data indicate a time-dependent response both within roots and between plant organs. Early on in roots, GSH was preferentially allocated to phytochelatin (PC) synthesis destined for Cd chelation. This led to decreased GSH levels, without alternative pathways activated...

  16. Redescriptions of six species of Ilyodromus Sars, 1894 (Crustacea, Ostracoda, Cyprididae) from New Zealand and Eastern Australia

    Shearn, Rylan; Halse, Stuart; Koenders, Annette; SCHON, Isa; Martens, Koen
    In this paper, we redescribe six species of the genus Ilyodromus Sars, 1894: I, stanleyanus (King, 1855), I. varrovillius (King, 1855), I. smaragdinus Sars, 1894, I. obtusus Sars, 1894, I. substriatus Sars, 1894 and I. viridulus (Brady, 1886) using materials stored in the Oslo museum (Norway) and (re-) described by G.O. Sars. For each species examined, we have identified a number of additional diagnostic characters to those used by Sars and earlier authors. In particular, the length of setae, claws and segments of the antennule, antenna, sixth limb, and caudal ramus appear to be important for species delineation in the...

  17. Perspectives for environment and health research in Horizon 2020: Dark ages or golden era?

    Smolders, Roel; DE BOEVER, Patrick
    The European Commission recently published the first calls for proposals for the Horizon 2020 (H2020) work programme for research and innovation. When browsing through the Health programme, it became apparent that the work programme made little reference to environmental health research. In this commentary we describe major milestones of environmental health research in previous European Framework Programmes and the policy shift that took place when preparing H2020. We introduce mobile health technologies as a niche innovation to reconcile the environmental health research arena with the H2020 programme that has a clear focus on ICT. The recent economic crises urged strong...

  18. Trace metals in blood and urine of newborn/mother pairs, adolescents and adults of the Flemish population (2007-2011)

    Baeyens, Willy; Vrijens, Jan; Gao, Yue; Croes, Kim; Schoeters, Greet; Den Hond, Elly; Sioen, Isabelle; BRUCKERS, Liesbeth; NAWROT, Tim; Nelen, Vera; Van den Mieroop, Els; Morrens, Bert; Loots, Ilse; Van Larebeke, Nicolas; Leermakers, Martine
    The Flemish Centre for Environment and Health started with human biomonitoring in 2002 (FLEHS I: 2002-2006). The main goal of the second human biomonitoring cycle (FLEHS II: 2007-2011), was to determine mean values for a large number of pollutants in a representative sample of the general Flemish population. Values for Cd and Pb were updated, and a group of previously undetermined metals and metalloids (As, Mn, Cu and Tl) were included in some of the age groups. In this human biomonitoring program, three different age groups of the general Flemish population were monitored: 255 newborns and their mothers, 210 adolescents...

  19. Airway oxidative stress and inflammation markers in exhaled breath from children are linked with exposure to black carbon.

    De Prins, S.; DONS, Evi; Van Poppel, M.; INT PANIS, Luc; Van de Mieroop, E.; Nelen, V.; Cox, Bianca; NAWROT, Tim; Teughels, C.; Schoeters, G.; Koppen, G.
    Background The current study aimed at assessing the associations between black carbon (BC) exposure and markers for airway inflammation and oxidative stress in primary school children in a Western European urban area. Methods In 130 children aged 6???12 years old, the fraction of exhaled nitric oxide (FeNO), exhaled breath condensate (EBC) pH, 8-isoprostane and interleukin (IL)-1?? were measured in two seasons. BC concentrations on the sampling day (2-h average, 8:00???10:00 AM) and on the day before (24-h average) were assessed using measurements at a central monitoring site. Land use regression (LUR) models were applied to estimate weekly average BC exposure integrated for the...

  20. Physical Activity, Air Pollution and the Brain

    Bos, I.; DE BOEVER, Patrick; INT PANIS, Luc; Meeusen, R.
    This review introduces an emerging research field that is focused on studying the effect of exposure to air pollution during exercise on cognition, with specific attention to the impact on concentrations of brain-derived neurotrophic factor (BDNF) and inflammatory markers. It has been repeatedly demonstrated that regular physical activity enhances cognition, and evidence suggests that BDNF, a neurotrophin, plays a key role in the mechanism. Today, however, air pollution is an environmental problem worldwide and the high traffic density, especially in urban environments and cities, is a major cause of this problem. During exercise, the intake of air pollution increases considerably...

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