Search results for "Exposure"
showing 10 items of 1125 documents
Assessing human health risks from pesticide use in conventional and innovative cropping systems with the BROWSE model
2017
Background: Reducing the risks and impacts of pesticide use on human health and on the environment is one of the objectives of the European Commission Directive 2009/128/EC in the quest for a sustainable use of pesticides. This Directive, developed through European national plans such as Ecophyto plan in France, promotes the introduction of innovative cropping systems relying, for example, on integrated pest management. Risk assessment for human health of the overall pesticide use in these innovative systems is required before the introduction of those systems to avoid that an innovation becomes a new problem. Objectives: The objectives of this work were to assess and to compare (1) the hum…
Monte Carlo evaluation of kerma in an HDR brachytherapy bunker
2004
In recent years, the use of high dose rate (HDR) after-loader machines has greatly increased due to the shift from traditional Cs-137/Ir-192 low dose rate (LDR) to HDR brachytherapy. The method used to calculate the required concrete and, where appropriate, lead shielding in the door is based on analytical methods provided by documents published by the ICRP, the IAEA and the NCRP. The purpose of this study is to perform a more realistic kerma evaluation at the entrance maze door of an HDR bunker using the Monte Carlo code GEANT4. The Monte Carlo results were validated experimentally. The spectrum at the maze entrance door, obtained with Monte Carlo, has an average energy of about 110 keV, m…
Sun exposure and PDZK1 genotype modulate PDZK1 gene expression in normal skin
2020
Human skin pigmentation results from the enzymatically controlled synthesis of melanin pigments in specialized organelles (melano‐somes) produced within epidermal melanocytes, followed by their transfer to neighboring keratinocytes and their distribution through‐out the epidermis.1 Constitutive skin pigmentation seems to be mostly genetically determined,2 being altered by numerous intrinsic and extrinsic factors affecting the epidermal melanin unit
Yttrium and lanthanides in human lung fluids, probing the exposure to atmospheric fallout.
2011
International audience; Inhalation of airborne particles can produce crystallization of phosphatic microcrysts in intraaveolar areas of lungs, sometimes degenerating into pulmonary fibrosis. Results of this study indicate that these pathologies are induced by interactions between lung fluids and inhaled atmospheric dust in people exposed to volcanic dust ejected from Mount Etna in 2001. Here, the lung solid-liquid interaction is evaluated by the distribution of yttrium and lanthanides (YLn) in fluid bronchoalveolar lavages on selected individuals according the classical geochemical approaches. We found that shale-normalised patterns of yttrium and lanthanides have a 'V shaped' feature corre…
Bisphenol-A impairs insulin action and up-regulates inflammatory pathways in human subcutaneous adipocytes and 3T3-L1 cells.
2013
Current evidence indicates that chemical pollutants may interfere with the homeostatic control of nutrient metabolism, thereby contributing to the increased prevalence of metabolic disorders. Bisphenol-A (BPA) is a lipophilic compound contained in plastic which is considered a candidate for impairing energy and glucose metabolism. We have investigated the impact of low doses of BPA on adipocyte metabolic functions. Human adipocytes derived from subcutaneous adipose tissue and differentiated 3T3-L1 cells were incubated with BPA, in order to evaluate the effect on glucose utilization, insulin sensitivity and cytokine secretion. Treatment with 1 nM BPA significantly inhibited insulin-stimulate…
Classification or non-classification of substances with positive tumor findings in animal studies: Guidance by the German MAK commission
2019
One of the important tasks of the German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (known as the MAK Commission) is in the evaluation of a potential for carcinogenicity of hazardous substances at the workplace. Often, this evaluation is critically based on data on carcinogenic responses seen in animal studies and, if positive tumor responses have been observed, this will mostly lead to a classification of the substance under investigation into one of the classes for carcinogens. However, there are cases where it can be demonstrated with a very high degree of confidence that the tumor findings in the experimental animals are not relevant…
Exposure to cigarette smoke extract and lipopolysaccharide modifies cytoskeleton organization in bronchial epithelial cells
2017
The integrity of the respiratory epithelium is crucial for airway homeostasis. Tobacco smoke exposure and recurrent infections of the airways play a crucial role in the progression and in the decline of the respiratory function in chronic obstructive pulmonary disease (COPD). The aim of this study was to detect differentially expressed proteins in a bronchial epithelial cell line (16-HBE) stimulated with cigarette smoke extract (CSE) and lipopolysaccharide (LPS), a constituent of gram-negative bacteria, alone and/or in combination, by using two-dimensional electrophoresis (2DE) analysis coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Western blot a…
Parental experience of a risky environment leads to improved offspring growth rate.
2014
Abstract Parasites (or diseases) are major selective force for the evolution of life history traits and parasite-host evolution. Mothers can show a variety of responses to parasites during pregnancy with different consequences for them or their offspring. However, whether information in the maternal environment before pregnancy can cause a change in the phenotype of the offspring is unknown. To avoid the confounding effect of pathogens and to reduce the risk of direct effect of mother's immune activation, we injected female laboratory mice with lipopolysaccharides (LPS) before mating. In order to provide a constant information on the potential infectious risk of the environment, females wer…
Regulation of T cells in asthma: implications for genetic manipulation
2004
PURPOSE OF THE REVIEW Allergic asthma is a disease characterized by airway hyperresponsiveness, inflammation and remodeling. In the past few decades it has become clear that the pathogenesis and development of this disease is controlled by cytokines released by CD4 T helper type 2 lymphocytes that develop under the influence of natural killer lymphocytes. At birth, T cell priming exhibits a T helper type 2 bias and the development of the T helper phenotype is determined in the first year of life by environmental exposure to virus or bacterial substances or environmental allergens in genetically predisposed individuals. Decreased exposure to infection in early childhood has thus been linked …
Partitioning of nanoparticle-originated dissolved silver in natural and artificial sediments
2017
Sediments are believed to be a major sink for silver nanoparticles (AgNPs) in the aquatic environment, but there is a lack of knowledge about the environmental effects and behavior of AgNPs in sediments. The release of highly toxic Ag+ through dissolution of AgNPs is one mechanism leading to toxic effects in sediments. We applied an ultrasound-assisted sequential extraction method to evaluate the dissolution of AgNPs and to study the partitioning of dissolved Ag in sediments. Silver was spiked into artificial and 2 natural sediments (Lake Hoytiainen sediment and Lake Kuorinka sediment) as silver nitrate (AgNO3 ), uncoated AgNPs, or polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs). In addition,…