Letteratura scientifica selezionata sul tema "Allergie au pollen – Effets de la pollution atmosphérique"
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Tesi sul tema "Allergie au pollen – Effets de la pollution atmosphérique":
Hamzé, Mona. "Vers une meilleure connaissance de l'exposition aux grains de pollens allergisants et de leur altération par la pollution de l'air". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. https://pepite-depot.univ-lille.fr/ToutIDP/EDSMRE/2022/2022ULILR009.pdf.
Although it is now accepted that allergenic pollen grains are altered by air pollution, the role of these alterations on allergy is not yet clearly known. The (bio)chemical mechanisms involved are not completely elucidated, especially with regard to the exacerbation of symptoms by air pollution. The main objective of this thesis is to improve the knowledge on the exposure to allergenic pollen grains by taking into account their degree of alteration: pollution and pollen grain rupture. A first laboratory study was carried out in order to explore the potential of several techniques for the characterization of the degree of alteration of the pollen grain. Pollen artificially polluted with ozone was analyzed by spectroscopic (Raman and infrared), microscopic and chromatographic techniques. Ozone uptake was also measured on a set of 22 pollen taxa with different bio-physical-chemical characteristics (grain size and mass, degree of allergenicity, lipid fraction...) to investigate possible determinants of ozone uptake. The potential of pollen analysis by gas chromatography-mass spectrometry (GC-MS) was exploited and a new method of counting pollen grains was developed. This method required a study on the variability of the lipid fraction on different batches of birch pollen from different geographical origins and depending on the year of harvest. In order to test this counting method in real conditions, a sampling campaign was carried out on sedimented birch pollen in indoor and outdoor environments. The determination of chemical tracers of pollen grains by GC-MS has a great potential for the rapid counting of pollen grains, the determination of their state (broken or intact) and their degree of pollution
Meier, Laurent. "Pollution atmosphérique et asthme". Paris 5, 1999. http://www.theses.fr/1999PA05P112.
Burte, Marthe-Emilie. "Rhinite : caractérisation et association avec la pollution atmosphérique". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLV004.
Whereas rhinitis has an important public health impact, in adults there is no standardized definition of rhinitis in epidemiological studies. Furthermore, environmental factors of rhinitis are barely known, and in particular, there are very few studies on the effects of long-term exposure to air pollution on rhinitis in adults. To fill these gaps, we used data from two European multicentre epidemiological studies with extensive data on respiratory health and individual estimated exposures to long-term air pollution. Our findings showed that to better characterize rhinitis, one need to consider together all the characteristics of the nasal symptoms, the comorbidities and the allergic sensitization, and not to restrict the disease to one question or one allergic sensitization test. We found no association between long-term air pollution and incidence of rhinitis, but we showed that long-term exposure to air pollution is associated to an increased severity of rhinitis, emphasising that air pollution needs to be controlled
Farah, Jinane. "Etude de la fraction lipidique de pollens allergisants et de ses modifications chimiques causées par les polluants atmosphériques". Thesis, Lille, 2018. http://www.theses.fr/2018LIL1R057.
The pollen lipidic fraction has an adjuvant effect on the allergic reaction and it is involved in germination processes. The alteration of pollen lipids by atmospheric pollutants is poorly documented in the literature although negative health effects are suspected. Our work was carried out on two highly allergenic pollens: timothy grass (phleum pratense) and birch tree (betula pendula). The lipid fraction of intact pollen was identified and quantified by gas chromatography equipped with a flame ionization detector or coupled to mass spectrometry. The main chemical families identified are: alkanes, alcohols, alkenes, saturated and unsaturated fatty acids, aldehydes and sterols. In vitro exposure of pollen to ozone has exhibited the reactivity of alkenes and the production of saturated fatty acids and aldehydes. Nitrogen dioxide has shown a protective role toward the reactivity of ozone. Furthermore, the bioavailability of lipids from intact pollen appears to be low as shown by pollen extractions with aqueous solvent without agitation. Moreover, our results give a new role to the rupture of pollen in the atmosphere. In fact, we observed a facilitated extraction of lipids for crushed pollen and in particular the release of immunostimulatory species such as linoleic and α-linolenic acids. The adjuvancy effects of the lipids extracted from broken or polluted pollen grains to the allergic reaction should be unraveled in a future work
Chassard, Guillaume. "Interaction de l’ozone avec des particules carbonées : cinétiques de capture, dégradation des HAP et impact sur la réponse inflammatoire épithéliale". Electronic Thesis or Diss., Lille 1, 2014. http://www.theses.fr/2014LIL10140.
Soot particles, ubiquitous in the urban atmosphere, exhibit extreme chemical and morphological complexity. Adsorbed on their surface, polycyclic aromatic hydrocarbons (PAHs) have a proven pulmonary toxicity. During atmospheric transport, they may, through oxidation and photolysis process, form oxygenated and nitrated products about which health impacts are not well known. We propose to characterize the atmospheric aging of soot particles and to study the impact of aging on the lungs. This work deals with the generation of soot models particles; laboratory simulation of aging by exposures to ozone; and the study of the inflammatory effects of aged or not particles on lung cells. In a first step a carbonaceous aerosol has been exposed to ozone in a flow reactor. The influences of contact time, initial ozone concentration, relative humidity, UV radiations and particle size were studied. The role of the atomic oxygen in the reaction mechanism was also evaluated. Then the heterogeneous reactivity between PAHs adsorbed on carbonaceous particles and ozone has been investigated. Degradation kinetics of particulate PAHs were thus performed. Finally, we studied the inflammatory response of PAHs alone or in particulate phase on lung cells by assay of pro-inflammatory interleukins. The effect of aging models particles and the role of pulmonary surfactant were evaluated
Farah, Jinane. "Etude de la fraction lipidique de pollens allergisants et de ses modifications chimiques causées par les polluants atmosphériques". Electronic Thesis or Diss., Université de Lille (2018-2021), 2018. http://www.theses.fr/2018LILUR057.
The pollen lipidic fraction has an adjuvant effect on the allergic reaction and it is involved in germination processes. The alteration of pollen lipids by atmospheric pollutants is poorly documented in the literature although negative health effects are suspected. Our work was carried out on two highly allergenic pollens: timothy grass (phleum pratense) and birch tree (betula pendula). The lipid fraction of intact pollen was identified and quantified by gas chromatography equipped with a flame ionization detector or coupled to mass spectrometry. The main chemical families identified are: alkanes, alcohols, alkenes, saturated and unsaturated fatty acids, aldehydes and sterols. In vitro exposure of pollen to ozone has exhibited the reactivity of alkenes and the production of saturated fatty acids and aldehydes. Nitrogen dioxide has shown a protective role toward the reactivity of ozone. Furthermore, the bioavailability of lipids from intact pollen appears to be low as shown by pollen extractions with aqueous solvent without agitation. Moreover, our results give a new role to the rupture of pollen in the atmosphere. In fact, we observed a facilitated extraction of lipids for crushed pollen and in particular the release of immunostimulatory species such as linoleic and α-linolenic acids. The adjuvancy effects of the lipids extracted from broken or polluted pollen grains to the allergic reaction should be unraveled in a future work
Chassard, Guillaume. "Interaction de l’ozone avec des particules carbonées : cinétiques de capture, dégradation des HAP et impact sur la réponse inflammatoire épithéliale". Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10140/document.
Soot particles, ubiquitous in the urban atmosphere, exhibit extreme chemical and morphological complexity. Adsorbed on their surface, polycyclic aromatic hydrocarbons (PAHs) have a proven pulmonary toxicity. During atmospheric transport, they may, through oxidation and photolysis process, form oxygenated and nitrated products about which health impacts are not well known. We propose to characterize the atmospheric aging of soot particles and to study the impact of aging on the lungs. This work deals with the generation of soot models particles; laboratory simulation of aging by exposures to ozone; and the study of the inflammatory effects of aged or not particles on lung cells. In a first step a carbonaceous aerosol has been exposed to ozone in a flow reactor. The influences of contact time, initial ozone concentration, relative humidity, UV radiations and particle size were studied. The role of the atomic oxygen in the reaction mechanism was also evaluated. Then the heterogeneous reactivity between PAHs adsorbed on carbonaceous particles and ozone has been investigated. Degradation kinetics of particulate PAHs were thus performed. Finally, we studied the inflammatory response of PAHs alone or in particulate phase on lung cells by assay of pro-inflammatory interleukins. The effect of aging models particles and the role of pulmonary surfactant were evaluated
Macaluso-Galletta, Anna. "Etude des niveaux de contamination en HAP et des différentes variables biologiques dans les grains de pollen de pin (Pinus nigra) et de frêne (Fraximus excelsior) du sillon Mosellan". Metz, 2004. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2004/Macaluso_Galletta.Anna.SMZ0423.pdf.
In this work, Pinus nigra (Black pine) and Fraxinus excelsior (European ash) pollens are used for the monitoring of PAHs in Metz area. In urban areas, these species are considered as ornamental trees. Moreover they have been shown to accumulate airborne PAHs. Depending on sources (urban or industrial). Pollens from both species were contaminated with PAHs, from 60 to 214 ug/g for the ash and from 101 to 229 ug/g for pine, especially 5/6 ring compounds. Total PAHs concentrations in pollen were positively correlated to acid phosphatase and esterase activities in different urban and industrial areas
Rancière, Fanny. "Phénotypes respiratoires et allergiques chez l'enfant jusqu'à l'âge de 4 ans en relation avec son environnement de vie : étude de la cohorte de naissance PARIS". Thesis, Paris 5, 2013. http://www.theses.fr/2013PA05S006.
Background: The natural history of asthma and allergies during childhood is still not fully understood. In addition, there are still some uncertainties about the contribution of behavioral and environmental factors to the development of these pathologies. Objectives: 1) To study the natural history of respiratory and allergic symptoms in children from birth to age 4 years by identifying phenotypes based upon these symptoms using cluster analyses, 2) To characterize these phenotypes with regard to their comorbidity and risk factors, especially those related to the life environment of children, including their early exposure to traffic-related air pollution (TAP). Methods: This work is part of the follow-up of the PARIS (Pollution and Asthma Risk: an Infant Study) birth cohort, implemented in 2003 and including 3840 newborns. Self-administered questionnaires regularly filled in by parents were used to collect information about the health status of children in terms of respiratory/allergic symptoms and diseases, as well as about lifestyle/environment characteristics. IgE-mediated sensitisation was determined at the age of 18 months. Exposure to TAP integrating the different places of residence and day-care was assessed in the first year of life of children using a dispersion model, the ExTra index. Respiratory/allergic phenotypes were identified between 0 and 4 years by cross-sectional and longitudinal cluster analyses. Comorbidity and risk factors associated with phenotypes were studied. Results: Between 0 and 4 years, wheezing has been reported in 31% of children, and dry night cough in 38%, whereas 43% and 38% have experienced symptoms suggestive of allergic rhinitis and atopic dermatitis, respectively. The prevalence of doctor-diagnosed diseases in the first 4 years was 12.2% for asthma, 39.4% for eczema and 3.8% for hay fever. The study of joint trajectories of symptoms such as wheezing, dry night cough, allergic rhinitis and atopic dermatitis identified a group with low prevalence of symptoms [n=1236, 49.0%] and four distinct phenotypes: two transient ("transient rhinitis" [n=295, 11.7%] and "transient wheeze" [n=399, 15.8%]), without any relation with IgE sensitisation, and two persistent ("cough/rhinitis" [n=284, 11.3%] and "dermatitis" [n=308, 12.2%]) associated with allergic sensitisation. Transient rhinitis phenotype was only associated with tobacco smoke exposure, which could irritate the airways. Transient wheeze phenotype was related to male sex and contact with other children (older siblings, day-care attendance). Lastly, risk factors for both IgE-associated phenotypes encompassed parental history of allergy, potential exposure to allergens and stress, known to be associated with the development of allergic diseases. With regard to allergic symptomatology, our results also show that the impact of early exposure to TAP could be more important in some subgroups of children (boys, children with parental history of allergy, and children whose mother experienced a serious health problem). Conclusion: This work contributes to a better understanding of the natural history of respiratory/allergic symptoms during preschool years, and provides evidence for the existence of different phenotypes before school age. The fact they differ in terms of sensitisation and risk factors reinforces the plausibility of distinct profiles, potentially linked to irritation and infections for the transient phenotypes, and to allergy for the persistent phenotypes