214 results on '"Lafay F"'
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52. L'analyse stroboscopique dans l'industrie
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Lafay, F., primary
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- 1965
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53. Traitements mécaniques par induction haute fréquence
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Lafay, F., primary
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- 1966
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54. Le soudage continu en atmosphère CO2
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Lafay, F., primary
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- 1963
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55. Evaluation of ABASTM : multi-center study in the case of prostate cancer.
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Ayadi, M., Delpon, G., Lafay, F., and Meyer, P.
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- 2011
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56. The CVS strain of rabies virus as transneuronal tracer in the olfactory system of mice
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Astic, L., Saucier, D., Coulon, P., and Lafay, F.
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- 1993
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57. Penetration and propagation of the CVS strain of rabies virus and its avirulent derivatives in the central nervous system of adult mice
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Coulon, P., Derbin, C., Lafay, F., and Flamand, A.
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- 1988
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58. Intercommunication and order transmission: application to Phenix nuclear power station
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Lafay, F
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- 1973
59. A MACHINE FOR AUTOMATIC MEASUREMENT, BY SCINTILLATION PROBING, OF LIQUID OR POWDERED RADIOACTIVE SAMPLES
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LaFay, F
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- 1964
60. IDENTIFICATION OF THE NATURE OF THE CONSTITUENTS OF A SUBSTANCE BY SPECTRUM ANALYSIS WITH X RAY FLUORESCENCE
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Lafay, F
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- 1962
61. The retinoid metabolism of Gammarus fossarum is disrupted by exogenous all-trans retinoic acid, citral, and methoprene but not by the technical formulation of glyphosate.
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Gauthier M, Daniele G, Giroud B, Lafay F, Vulliet E, Jumarie C, Garric J, Boily M, and Geffard O
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- Animals, Female, Ecosystem, Tandem Mass Spectrometry, Tretinoin, Retinoids, Isotretinoin, Retinaldehyde metabolism, Glyphosate, Methoprene, Vitamin A
- Abstract
Over the last decade, fluctuations of retinoids (RETs), also known as vitamin A and derivatives, have proved to be useful biomarkers to assess the environmental chemical pressure on a wide variety of non-target vertebrates. This use of RET-based biomarkers is of particular interest in the non-target sentinel species Gammarus fossarum in which RETs were shown to influence crucial physiological functions. To study and probe this metabolism in this crustacean model, a UHPLC-MS/MS method was developed to 1) identify and 2) monitor several endogenous RETs in unexposed females throughout their reproductive cycle. Then, females were exposed in controlled conditions to exogenous all-trans retinoic acid (atRA) and citral (CIT), a RA synthesis inhibitor, to simulate an excess or deficiency in RA. Perturbation of vitamin A metabolism by pesticides was further studied in response to methoprene (MET), a juvenile hormone analog as well as glyphosate (GLY). The developed method allowed, for the first time in this model, the identification of RA metabolites (all-trans 4-oxo and 13-cis 4-oxo RA), RA isomers (all-trans and 13-cis RA) as well as retinaldehyde (RALD) isomers (all-trans, 11-cis, and 13-cis RALD) and showed two distinct phases in the reproductive cycle. Retinoic acid successfully increased the tissular concentration of both RA isomers and CIT proved to be efficient at perturbating the conversion from RALD to RA. Methoprene perturbed the ratios between RA isomers whereas GLY had no observed effects on the RET system of G. fossarum females. We were able to discriminate different dynamics of RET perturbations by morphogens (atRA or CIT) or MET which highlights the plausible mediation of RETs in MET-induced disorders. Ultimately, our study shows that RETs are influenced by exposure to MET and strengthen their potential to assess aquatic ecosystem chemical status., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2023
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62. Evaluation of the accumulation of the iodinated contrast agents diatrizoic acid and iohexol in Dreissena polymorpha mollusks.
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Daniele G, Lafay F, Arnaudguilhem C, Mounicou S, Geffard A, Bonnard I, Dedourge-Geffard O, Bonnefoy C, and Vulliet E
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- Animals, Iohexol analysis, Diatrizoate analysis, Contrast Media toxicity, Contrast Media analysis, Dreissena, Water Pollutants, Chemical toxicity, Water Pollutants, Chemical analysis, Iodine Compounds, Bivalvia, Iodine
- Abstract
Mollusks are very sensitive to aquatic environmental alterations and then, are important bio-indicators for monitoring the contamination of water bodies. Iodinated X-ray contrast media (ICMs) are ubiquitously present in the aquatic environment, primarily due to their high consumption for diagnosis purposes, high injection levels, low biodegradability, and low removal rates by wastewater treatment plants. Although these compounds are assumed to be of low toxicity, aquatic organisms are continuously exposed to these agents, which may result in adverse effects as ICMs can act as iodine source and disrupt the endocrine system. Thus, the evaluation of their environmental risk, especially on aquatic fauna is of great interest. To this end, we first compared the accumulation behavior, based on iodine analysis, of two ICM exhibiting different osmolality, diatrizoic acid and iohexol in Dreissena polymorpha bivalves exposed under laboratory conditions at concentrations of 0, 100, and 1000 μg/L during 4 and 7 days. This study was the first to provide information on iodine concentration in whole soft tissues and several organs in control zebra mussels. Moreover, it showed, after exposure, an increase of iodine content mainly in the digestive glands, followed by gills and gonads, highlighting that ICMs actually enter the organisms. Thus, bioaccumulation of ICMs studies were then performed, by liquid chromatography coupled to tandem mass spectrometry, on entire mollusks and digestive glands of organisms exposed at 0, 10, 100, and 1000 μg/L of both ICMs during 21 days, followed by 4 days of depuration. These first data on ICMs concentrations in zebra mussels, showed a clear accumulation of ICMs in mussels as a function of relative exposure level, as well as a rapid depuration. Osmolality did not seem to have a significant impact on the accumulation level, but a slight difference was observed on the accumulation pattern between both ICMs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
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- 2023
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63. Combined intra-cavitary and interstitial image-guided adaptative brachytherapy for cervical stump carcinomas: technical and clinical results of six patients.
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Guillemin F, Serre AA, Gassa F, Lorchel F, Sandt M, Lafay F, Charret J, Rannou C, and Pommier P
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Purpose: According to European guidelines for cervix cancers, the management of cervical stump cancers should follow recommendations for patients without previous sub-total hysterectomy, but may require adaptation of radiotherapy modalities, especially brachytherapy (BT). However, data with modern BT technics are very scarce., Material and Methods: From May 2013 to March 2020, 6 patients (age range, 71-88 years) with cervical stump squamous cell carcinoma (previously treated by sub-total hysterectomy) have been treated with external beam radiotherapy (intensity-modulated radiation therapy - IMRT, 45 Gy in 25 fractions, 5 patients, or 50.4 Gy in 28 fractions, 1 patient), with concomitant chemotherapy in 2 patients, followed by image-guided adaptive brachytherapy with pulsed-dose-rate in 5 patients or high-dose-rate in 1 patient. We used Utrecht BT applicator (Elekta
® ), with the implant of interstitial needles within the parametrium (unilaterally in 3 and bilaterally in 3 patients), and/or within the residual cervix (3 patients). Dosimetry was based on GEC-ESTRO recommendations., Results: The median high-risk (HR) and intermediate-risk (IR) clinical target volumes (CTV) were 14.5 cc (range, 12-35 cc) and 40 cc (range, 31-62 cc), respectively. The median dose (D90 ) delivered to HR and IR CTVs were 81.2 (range, 78.2-89.8) and 68.95 (range, 64.3-72.3) Gy EQD2 , respectively. With a 26.5 months median follow-up (range, 10-92 months), we did not observe any local or distant recurrence. No grade 2 or more acute or late toxicities were reported., Conclusions: Cervix brachytherapy with Utrecht applicator using interstitial needle is safe and effective in cervical stump cancer patients., Competing Interests: The authors report no conflict of interest., (Copyright © 2022 Termedia.)- Published
- 2022
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64. Ultrasound-assisted QuEChERS-based extraction using EDTA for determination of currently-used pesticides at trace levels in soil.
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Lafay F, Daniele G, Fieu M, Pelosi C, Fritsch C, and Vulliet E
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It is essential to monitor pesticides in soils as their presence at trace levels and their bioavailability can induce adverse effects on soil's ecosystems, animals, and human health. In this study, we developed an analytical method for the quantification of traces of multi-class pesticides in soil using liquid chromatography-tandem mass spectrometry. In this way, 31 pesticides were selected, including 12 herbicides, 9 insecticides, and 10 fungicides. Two extraction techniques were first evaluated, namely, the pressurized liquid extraction and the QuEChERS procedure. The latest one was finally selected and optimized, allowing extraction recoveries of 55 to 118%. The role of the chelating agent EDTA, which binds preferentially to soil cations that complex some pesticides, was highlighted. Coupled with liquid chromatography-tandem mass spectrometry, the procedure displayed very high sensitivity, with limits of quantification (LOQ) in the range 0.01-5.5 ng/g. A good linearity (R
2 > 0.992) was observed over two orders of magnitude (LOQ-100 [Formula: see text] LOQ) with good accuracy (80-120%) for all compounds except the two pyrethroids lambda-cyhalothrin and tau-fluvalinate (accuracy comprised between 50 and 175%) and the cyclohexanedione cycloxydim (accuracy < 35%). Good repeatability and reproducibility were also achieved. The method was finally successfully applied to 12 soil samples collected from 3 land-use types. Among the 31-targeted pesticides, 24 were detected at least once, with concentration levels varying from LOQ to 722 ng/g. Many values were below 0.5 ng/g, indicating that the developed method could provide new knowledge on the extremely low residual contents of some pesticides., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2022
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65. Design of Hybrid PAH Nanoadsorbents by Surface Functionalization of ZrO 2 Nanoparticles with Phosphonic Acids.
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Bou Orm N, Gréa T, Hamandi M, Lambert A, Lafay F, Vulliet E, and Daniele S
- Abstract
This study focuses on the preparation of innovative nanocomposite materials based on surface modification of commercial nano-ZrO
2 optimized from Brønsted acid-base surface reactions. This surface modification was carried out by direct grafting of suitable phosphonic acids bearing a vinylic or phenylic substituent in aqueous solution. Different loading quantities of the anchoring organophosphorus compounds were applied for each materials synthesis. The resulting nanohybrids were thoroughly characterized by infrared spectroscopy (DRIFT), solid-state nuclear magnetic resonance (NMR), nitrogen adsorption-desorption (BET), thermogravimetric analysis (TG), and X-ray photoelectron spectroscopy (XPS), demonstrating the reliability and efficient tunability of the surface functionalization based on the starting Zr/P ratio. Our nanocomposite materials exhibited a high specific surface area as well as complex porosity networks with well-defined meso-pore. The as-prepared materials were investigated for the adsorption of a mixture of 16 polycyclic aromatic hydrocarbons (PAHs) at 200 ng·mL-1 in an aqueous solution. Adsorption kinetics experiments of each individual material were carried out on the prepared PAHs standard solution for a contact time of up to 6 h. Pretreatments of the adsorption test samples were performed by solid-phase extraction (SPE), and the resulting samples were analyzed using an ultrasensitive GC-orbitrap-MS system. The pseudo-first-order and the pseudo-second-order models were used to determine the kinetic data. The adsorption kinetics were best described and fitted by the pseudo-second-order kinetic model. The correlation between the nature of the substituent (vinylic or phenylic) and the parameters characterizing the adsorption process were found. In addition, an increase of PAHs adsorption rates with phosphonic acid loading was observed.- Published
- 2021
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66. Correction to: National dose reference levels in computed tomography-guided interventional procedures-a proposal.
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Greffier J, Ferretti G, Rousseau J, Andreani O, Alonso E, Rauch A, Gillet R, Le Roy J, Cabrol-Faivre L, Douane F, David A, Henry S, Jacques T, Stefanovic X, Decoux E, Lafay F, Pilleul F, Couzon F, Boutet C, Woerly B, Baur P, Sans N, Faruch M, Moussier-Lherm A, Tselikas L, Jacquier A, Bigand E, Pessis E, Teriitehau C, Magnier F, Cassagnes L, Haberlay M, Boutteau D, De Kerviler E, Majorel-Gouthain C, Defez D, Vuillod A, Rouviere O, Hennequin L, Fohlen A, Alwan R, Malakhia A, Aubry S, Dohan A, Eresue-Bony M, Gautier R, Dal R, Dabli D, Hebert T, Kovacs R, Hadid-Beurrier L, Bousson V, Potel M, Barbotteau Y, Michel C, Habib-Geryes B, André M, Arnaud T, Bestion N, Ernst O, Monfraix S, Brillet PY, Guiu B, Boussel L, Demonchy M, Beregi JP, and Frandon J
- Abstract
The original version of this article, published on 02 May 2020, unfortunately contained a mistake.
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- 2020
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67. National dose reference levels in computed tomography-guided interventional procedures-a proposal.
- Author
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Greffier J, Ferretti G, Rousseau J, Andreani O, Alonso E, Rauch A, Gillet R, Le Roy J, Cabrol-Faivre L, Douane F, David A, Henry S, Jacques T, Stefanovic X, Decoux E, Lafay F, Pilleul F, Couzon F, Boutet C, Woerly B, Baur P, Sans N, Faruch M, Moussier-Lherm A, Tselikas L, Jacquier A, Bigand E, Pessis E, Teriitehau C, Magnier F, Cassagnes L, Haberlay M, Boutteau D, De Kerviler E, Majorel-Gouthain C, Defez D, Vuillod A, Rouviere O, Hennequin L, Fohlen A, Alwan R, Malakhia A, Aubry S, Dohan A, Eresue-Bony M, Gautier R, Dal R, Dabli D, Hebert T, Kovacs R, Hadid-Beurrier L, Bousson V, Potel M, Barbotteau Y, Michel C, Habib-Geryes B, André M, Arnaud T, Bestion N, Ernst O, Monfraix S, Brillet PY, Guiu B, Boussel L, Demonchy M, Beregi JP, and Frandon J
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- Adolescent, Adult, Aged, Aged, 80 and over, Biopsy, Female, Fluoroscopy methods, France, Humans, Male, Middle Aged, Radiography, Interventional methods, Reproducibility of Results, Retrospective Studies, Spine, Surveys and Questionnaires, Tomography, X-Ray Computed methods, Vertebroplasty, Young Adult, Radiation Dosage, Radiography, Interventional standards, Reference Values, Tomography, X-Ray Computed standards
- Abstract
Objectives: To establish national reference levels (RLs) in interventional procedures under CT guidance as required by the 2013/59/Euratom European Directive., Methods: Seventeen categories of interventional procedures in thoracic, abdominopelvic, and osteoarticular specialties (percutaneous infiltration, vertebroplasty, biopsy, drainage, tumor destruction) were analyzed. Total dose length product (DLP), number of helical acquisitions (NH), and total DLP for helical, sequential, or fluoroscopic acquisitions were recorded for 10 to 20 patients per procedure at each center. RLs were calculated as the 3rd quartiles of the distributions and target values for optimization process (TVOs) as the median. RLs and TVOs were compared with previously published studies., Results: Results on 5001 procedures from 49 centers confirmed the great variability in patient dose for the same category of procedures. RLs were proposed for the DLPs and NHs in the seventeen categories. RLs in terms of DLP and NH were 375 mGy.cm and 2 NH for spinal or peri-spinal infiltration, 1630 mGy.cm and 3 NH for vertebroplasty, 845 mGy.cm and 4 NH for biopsy, 1950 mGy.cm and 8 NH for destruction of tumors, and 1090 mGy.cm and 5 NH for drainage. DLP and NH increased with the complexity of procedures., Conclusions: This study was the first nationwide multicentric survey to propose RLs for interventional procedures under CT guidance. Heterogeneity of practice in centers were found with different levels of patient doses for the same procedure. The proposed RLs will allow imaging departments to benchmark their practice with others and optimize their protocols., Key Points: • National reference levels are proposed for 17 categories of interventional procedures under CT guidance. • Reference levels are useful for benchmarking practices and optimizing protocols. • Reference levels are proposed for dose length product and the number of helical acquisitions.
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- 2020
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68. Does water temperature influence the distribution and elimination of perfluorinated substances in rainbow trout (Oncorhynchus mykiss)?
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Vidal A, Lafay F, Daniele G, Vulliet E, Rochard E, Garric J, and Babut M
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- Animals, Dietary Exposure, Muscles chemistry, Temperature, Tissue Distribution, Alkanesulfonic Acids pharmacokinetics, Fluorocarbons pharmacokinetics, Oncorhynchus mykiss metabolism, Sulfonic Acids pharmacokinetics, Water Pollutants, Chemical pharmacokinetics
- Abstract
Perfluorinated and polyfluorinated substances (PFASs) are widely found in freshwater ecosystems because of their resistance to degradation and their ability to accumulate in aquatic organisms. While water temperature controls many physiological processes in fish, knowledge of the effects of this factor on PFAS toxicokinetic is still limited. This study presents experimental results of internal distribution and elimination rates of two perfluorinated acid compounds, namely perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) in adult rainbow trout (Oncorhynchus mykiss) exposed to three temperatures. Dietary exposure experiments were conducted at 7 °C, 11 °C, and 19 °C and liver, blood, muscle, brain, and kidney were sampled for analysis. PFOS concentrations were comparable to or exceeded those of PFHxS, while PFHxS was eliminated faster than PFOS, whatever the temperature. Internal distribution changed significantly for both substances when fish were exposed to a range of temperatures from 7 to 19 °C. Indeed, PFOS and PFHxS relative distribution increased in blood, liver, and brain while they decreased in muscle when the water temperature rose. The water temperature variation affected the elimination half-lives, depending on the substances and organs.
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- 2019
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69. Priority substances in accumulated sediments in a stormwater detention basin from an industrial area.
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Wiest L, Baudot R, Lafay F, Bonjour E, Becouze-Lareure C, Aubin JB, Jame P, Barraud S, Kouyi GL, Sébastian C, and Vulliet E
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- Benzhydryl Compounds analysis, France, Halogenated Diphenyl Ethers analysis, Pesticides analysis, Phenols analysis, Urbanization, Environmental Monitoring methods, Geologic Sediments chemistry, Water Pollutants, Chemical analysis, Water Pollution analysis
- Abstract
One of the most adopted solutions in developed countries to manage stormwater is detention/retention basins which generate large quantities of sediments that have to be removed regularly. In order to manage them properly, accurate data are needed about their physical and chemical characteristics, particularly on micropollutant concentrations and their associated risk. This work consisted in a two-year sampling of dry sediments from a detention-settling basin. Priority substances, including pesticides, polybrominated diphenyl ethers (PBDE), alkylphenols and bisphenol A (BPA), were monitored. Different sites in the basin bottom were sampled in order to investigate spatial distribution of the contamination. Results show that the increase of the sediment thickness in the basin was heterogeneous with a maximum of 15 cm after two years. Pesticides and PBDE were, if detected, mainly found in low concentrations from 2 ng/g to 286 ng/g. Conversely, alkylphenols and bisphenol A were always quantified at concentrations varying from 6 ng/g to 3400 ng/g. These high levels suggest that these sediments should be managed with precautions. Spatial heterogeneity of alkylphenol ethoxylates and BPA concentrations was observed, with higher contamination of alkylphenol ethoxylates in anaerobic zones and BPA levels correlated with total organic carbon and in a lesser extent to fine particles., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
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70. Development of a method for the simultaneous determination of multi-class pesticides in earthworms by liquid chromatography coupled to tandem electrospray mass spectrometry.
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Daniele G, Lafay F, Pelosi C, Fritsch C, and Vulliet E
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- Animals, Limit of Detection, Solid Phase Extraction methods, Chromatography, High Pressure Liquid methods, Oligochaeta chemistry, Pesticide Residues analysis, Pesticides analysis, Tandem Mass Spectrometry methods
- Abstract
Agricultural intensification, and in particular the use of pesticides, leads over the years to a loss of biodiversity and a decline of ecosystem services in cultivated zones and agricultural landscapes. Among the animal communities involved in the functioning of agro-ecosystems, earthworms are ubiquitous and recognized as indicators of land uses and cultural practices. However, little data is available on the levels of pesticides in such organisms in natura, which would allow estimating their actual exposure and the potentially resulting impacts. Thus, the objective of this study was to develop a sensitive analytical methodology to detect and quantify 27 currently used pesticides in earthworms (Allolobophora chlorotica). A modified QuEChERS extraction was implemented on individual earthworms. This step was followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The whole analytical method was validated on spiked earthworm blank samples, with regard to linearity (from 1 to 100 method limit of quantification, r
2 > 0.95), intra-day precision (relative standard deviation (RSD) < 15%), inter-day precision (RSD < 20%), recoveries (mainly in the range 70-110%), and limits of detection and of quantification (inferior to 5 ng/g for most of the pesticides). The developed method was successfully applied to determine the concentrations of pesticides in nine individuals collected in natura. Up to five of the selected pesticides have been detected in one individual. Graphical abstract.- Published
- 2018
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71. Human exposure assessment to a large set of polymer additives through the analysis of urine by solid phase extraction followed by ultra high performance liquid chromatography coupled to tandem mass spectrometry.
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Pouech C, Kiss A, Lafay F, Léonard D, Wiest L, Cren-Olivé C, and Vulliet E
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- Environmental Pollutants analysis, Humans, Chromatography, High Pressure Liquid, Environmental Exposure analysis, Polymers analysis, Solid Phase Extraction, Tandem Mass Spectrometry, Urinalysis methods
- Abstract
Polymer items are extensively present in the human environment. Humans may be consequently exposed to some compounds, such as additives, incorporated in these items. The objective of this work is to assess the human exposure to the main additives such as those authorized in the packaging for pharmaceutical products. The urinary matrix was selected to optimally answer this challenge because it has already been proven that the exposure to chemicals can be revealed by the analysis of this biological matrix. A multi-residue analytical method for the trace analysis at ng/mL in human urine was developed, and consisted of an extraction of analytes from urine by solid phase extraction (SPE) and an analysis by ultra-high performance liquid chromatography coupled to a tandem mass spectrometer (UHPLC-MS/MS). Even if the quantification of these compounds was an analytical challenge because of (i) the presence of these substances in the analytical process, (ii) the diversity of their physicochemical properties, and (iii) the complexity of the matrix, the optimized method exhibited quantification limits lower than 25ng/mL and recoveries between 51% and 120% for all compounds. The method was validated and applied to 52 human urines. To the best of our knowledge, this work presents the first study allowing the assessment of the occurrence of more than twenty polymer additives at ng/mL in human urine., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
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72. A pragmatic approach to assess the exposure of the honey bee (Apis mellifera) when subjected to pesticide spray.
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Poquet Y, Bodin L, Tchamitchian M, Fusellier M, Giroud B, Lafay F, Buleté A, Tchamitchian S, Cousin M, Pélissier M, Brunet JL, and Belzunces LP
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- Animals, Bees physiology, Body Surface Area veterinary, Chromatography, Gas, Environmental Exposure, Lethal Dose 50, Pesticides analysis, Bees drug effects, Models, Theoretical, Pesticides toxicity
- Abstract
Plant protection spray treatments may expose non-target organisms to pesticides. In the pesticide registration procedure, the honey bee represents one of the non-target model species for which the risk posed by pesticides must be assessed on the basis of the hazard quotient (HQ). The HQ is defined as the ratio between environmental exposure and toxicity. For the honey bee, the HQ calculation is not consistent because it corresponds to the ratio between the pesticide field rate (in mass of pesticide/ha) and LD50 (in mass of pesticide/bee). Thus, in contrast to all other species, the HQ can only be interpreted empirically because it corresponds to a number of bees/ha. This type of HQ calculation is due to the difficulty in transforming pesticide field rates into doses to which bees are exposed. In this study, we used a pragmatic approach to determine the apparent exposure surface area of honey bees submitted to pesticide treatments by spraying with a Potter-type tower. The doses received by the bees were quantified by very efficient chemical analyses, which enabled us to determine an apparent surface area of 1.05 cm(2)/bee. The apparent surface area was used to calculate the exposure levels of bees submitted to pesticide sprays and then to revisit the HQ ratios with a calculation mode similar to that used for all other living species. X-tomography was used to assess the physical surface area of a bee, which was 3.27 cm(2)/bee, and showed that the apparent exposure surface was not overestimated. The control experiments showed that the toxicity induced by doses calculated with the exposure surface area was similar to that induced by treatments according to the European testing procedure. This new approach to measure risk is more accurate and could become a tool to aid the decision-making process in the risk assessment of pesticides.
- Published
- 2014
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73. A national reconnaissance for selected organic micropollutants in sediments on French territory.
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Vulliet E, Berlioz-Barbier A, Lafay F, Baudot R, Wiest L, Vauchez A, Lestremau F, Botta F, and Cren-Olivé C
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- Benzhydryl Compounds analysis, Chromatography, Liquid methods, Environmental Monitoring, France, Gas Chromatography-Mass Spectrometry methods, Pesticides analysis, Pharmaceutical Preparations analysis, Phenols analysis, Polycyclic Aromatic Hydrocarbons analysis, Tandem Mass Spectrometry methods, Geologic Sediments analysis, Water Pollutants, Chemical analysis
- Abstract
To collect a large data set regarding the occurrence of organic substances in sediment, this study presents the examination of 20 micropollutants, as a national survey. The list of target compounds contains two alkylphenols, three polycyclic aromatic hydrocarbons (PAHs) not commonly included in monitoring programmes, six pesticides or metabolites, five pharmaceutical compounds, two hormones, one UV filter and bisphenol A. The selective and sensitive analytical methods, based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) or gas chromatography-time-of-flight mass spectrometry (GC-ToF-MS), allow the quantification at limits comprised between 0.5 and 23 ng/g, depending on the compound. The paper summarizes the analytical results from 154 sampling points. Of the 20 target compounds, 9 were determined at least once, and the sediments contained a maximum of 7 substances. The most frequently detected were PAHs (frequency, 77 %; max., 1,400 ng/g). The pharmaceutical compounds, hormones and pesticides were rarely detected in the samples; the most frequently detected was carbamazepine (frequency, 6 %; max., 31 ng/g). In some cases, the levels of PAHs and bisphenol A exceed the predicted no-effect concentration (PNEC) values.
- Published
- 2014
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74. Survey regarding the occurrence of selected organic micropollutants in the groundwaters of overseas departments.
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Vulliet E, Tournier M, Vauchez A, Wiest L, Baudot R, Lafay F, Kiss A, and Cren-Olivé C
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- Benzhydryl Compounds analysis, Carbamazepine analysis, Chromatography, Liquid, Comoros, French Guiana, Gas Chromatography-Mass Spectrometry, Guadeloupe, Martinique, Pentachlorophenol analysis, Pesticides analysis, Phenols analysis, Reunion, Sensitivity and Specificity, Solid Phase Extraction, Tandem Mass Spectrometry, Groundwater chemistry, Water Pollutants, Chemical analysis
- Abstract
To collect a complete dataset regarding the occurrence of organic substances in groundwater, this study presents the examination of 66 organic contaminants in the groundwater of overseas departments, including pesticides, pharmaceutical compounds, hormones and some industrial substances. The selective and sensitive analytical methods are described. These techniques begin with solid-phase extraction (SPE) followed by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-ToF-MS). The paper summarises the analytical results from 40 sampling points collected during two campaigns in Guadeloupe, Martinique, Reunion, Mayotte and Guiana, representing 80 samples. Of the 66 target substances, 36 were determined at least once. Among the most frequently detected are bisphenol A (frequency, 96%; max., 7,400 ng/L), caffeine (frequency, 91%; max., 1,240 ng/L), pentachlorophenol (frequency, 55%; max., 418 ng/L), and carbamazepine (frequency, 56%; max., 22 ng/L). The results do not put in evidence that the origin of the sample or climatic characteristics of these regions influence the dilution and release of micropollutants.
- Published
- 2014
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75. Monitoring the extraction of additives and additive degradation products from polymer packaging into solutions by multi-residue method including solid phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry analysis.
- Author
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Pouech C, Lafay F, Wiest L, Baudot R, Léonard D, and Cren-Olivé C
- Abstract
The use of polymer materials in industry for product packaging is increasing. The presence of additives in the polymer matrix enables the modification or improvement of the properties and performance of the polymer, but these industries are concerned regarding the extractability of these additives. The quantification of these additives is particularly challenging because of the presence of these substances as contaminants in all the analytical equipment and the diversity of their physicochemical properties. In this context, a multi-residue analytical method was developed for the trace analysis of the twenty main additives (and their degradation products) authorized in plastic products such as pharmaceutical packaging (e.g., antioxidants, release agents, and light absorbers). This analytical method consisted of a solid phase extraction (SPE) followed by an analysis using ultra-high performance liquid chromatography coupled to a tandem mass spectrometer (UHPLC-MS/MS). A comparison of two ionization interfaces and the optimization of the extraction procedure were discussed. The influence of the quality of the solvent type (distilled versus not distilled) and the nature of the SPE cartridges (Polypropylene versus Teflon(®)) were demonstrated. The optimized method exhibited a quantification limit lower than 20 ng mL(-1) and recoveries between 70 % and 120 % for all compounds. Finally, the method was validated according to the ICH directive and was subsequently applied to the extraction of polymers under different pH conditions and storage temperatures. To the best of our knowledge, this study presents the first methodology allowing the simultaneous quantification of 24 additives at low ng mL(-1).
- Published
- 2014
- Full Text
- View/download PDF
76. Multi-residue analysis of free and conjugated hormones and endocrine disruptors in rat testis by QuEChERS-based extraction and LC-MS/MS.
- Author
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Pouech C, Tournier M, Quignot N, Kiss A, Wiest L, Lafay F, Flament-Waton MM, Lemazurier E, and Cren-Olivé C
- Subjects
- Animals, Drug Residues isolation & purification, Endocrine Disruptors isolation & purification, Hormones analysis, Hormones isolation & purification, Humans, Male, Rats, Rats, Sprague-Dawley, Chemical Fractionation methods, Chromatography, Liquid methods, Drug Residues analysis, Endocrine Disruptors analysis, Tandem Mass Spectrometry methods, Testis chemistry
- Abstract
Endocrine disrupting compounds (EDCs) are suspected to be responsible for many disorders of the human reproductive system. To establish a causality relationship between exposure to endocrine disruptors and disease, experiments on animals must be performed with improved or new analytical tools. Therefore, a simple, rapid, and effective multi-residue method was developed for the determination of four steroid hormones (i.e., testosterone, androstenedione, estrone, and estradiol), glucuronide and sulfate conjugates of estrone and estradiol and four endocrine disruptors in rat testis (i.e., bisphenol A, atrazine, and active metabolites of methoxychlor and vinclozolin). The sample preparation procedure was based on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) approach. An analytical method was then developed to quantify these compounds at ultra-trace levels by liquid chromatography coupled to tandem mass spectrometry. The QuEChERS extraction was optimized with regard to the acetonitrile/water ratio used in the extraction step, the choice of the cleanup method and the acetonitrile/hexane ratio used in the cleanup step. The optimized extraction method exhibited recoveries between 89% and 108% for all tested compounds except the conjugates (31% to 58%). The detection limits of all compounds were below 20 ng g(-1) of wet weight of testis. The method was subsequently applied to determine the levels of hormones and EDCs in seven rat testis samples.
- Published
- 2012
- Full Text
- View/download PDF
77. Contribution of microextraction in packed sorbent for the analysis of cotinine in human urine by GC-MS.
- Author
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Lafay F, Vulliet E, and Flament-Waton MM
- Subjects
- Humans, Limit of Detection, Solid Phase Microextraction instrumentation, Cotinine urine, Gas Chromatography-Mass Spectrometry methods, Solid Phase Microextraction methods
- Abstract
A simple, rapid, sensitive, and non-consuming solvent method for the determination of cotinine in urine was developed, based on sample preparation by the relatively new technique microextraction in packed sorbent (MEPS) and analysis by GC-MS. This optimized method was compared with conventional solid-phase extraction/liquid-liquid extraction method used as reference. The wide linear range (5-5,000 ng/mL) and high sensitivity of the MEPS method (limit of detection 0.8 ng/mL) allow application to analysis of urine from smokers as well as non-smokers susceptible to passive smoking.
- Published
- 2010
- Full Text
- View/download PDF
78. The rabies virus glycoprotein receptor p75NTR is not essential for rabies virus infection.
- Author
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Tuffereau C, Schmidt K, Langevin C, Lafay F, Dechant G, and Koltzenburg M
- Subjects
- Animals, Antigens, Viral metabolism, COS Cells, Cells, Cultured, Chlorocebus aethiops, Female, Ganglia, Spinal cytology, Ganglia, Spinal virology, Glycoproteins metabolism, Male, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Neurons cytology, Neurons virology, Receptors, Nerve Growth Factor deficiency, Receptors, Nerve Growth Factor genetics, Viral Envelope Proteins metabolism, Rabies virology, Rabies virus pathogenicity, Receptors, Nerve Growth Factor metabolism, Receptors, Virus metabolism
- Abstract
Rabies virus glycoprotein (RVG) is known to be the only factor that mediates rabies infection. The neurotrophin receptor (p75(NTR)), through its cysteine-rich domain 1, is a specific receptor for RVG and neutralizes virus infectivity, but its role in virus infection has remained obscure. We used adult mouse dorsal root ganglion (DRG) neurons as a model to study the role of p75(NTR) in RV infection of primary neurons. We show that RV infects around 20% of DRG neurons, of which more than 80% are p75(NTR) positive, have large diameters, and are capsaicin insensitive. Surprisingly, RV binding and infection are absent in about half of the p75(NTR)-expressing DRG neurons which have small diameters and are often capsaicin sensitive. This indicates that p75(NTR) is not sufficient to mediate RV interaction in sensory neurons. The rate and specificity of neural infection are unchanged in RV-infected p75(NTRExonIV-/-) mice that lack all extracellular receptor domains and in wild-type mice infected with two independent RV mutants that lack p75(NTR) binding. Accordingly, the mortality rate is unchanged in the absence of RV-p75(NTR) interaction. We conclude that although p75(NTR) is a receptor for soluble RVG in transfected cells of heterologous expression systems, an RVG-p75(NTR) interaction is not necessary for RV infection of primary neurons. This means that other receptors are required to mediate RV infection in vivo and in vitro.
- Published
- 2007
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- View/download PDF
79. Herpes simplex virus type 1 latently infected neurons differentially express latency-associated and ICP0 transcripts.
- Author
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Maillet S, Naas T, Crepin S, Roque-Afonso AM, Lafay F, Efstathiou S, and Labetoulle M
- Subjects
- Animals, Brain virology, Female, Humans, Immediate-Early Proteins chemistry, Introns, Mice, Mice, Inbred BALB C, RNA Splicing, RNA, Messenger metabolism, Ubiquitin-Protein Ligases chemistry, Gene Expression Regulation, Viral, Herpesvirus 1, Human metabolism, Immediate-Early Proteins biosynthesis, Neurons virology, Ubiquitin-Protein Ligases biosynthesis
- Abstract
During the latent phase of herpes simplex virus type 1 (HSV-1) infection, the latency-associated transcripts (LATs) are the most abundant viral transcripts present in neurons, but some immediate-early viral transcripts, such as those encoding ICP0, have also been reported to be transcribed in latently infected mouse trigeminal ganglia (TG). A murine oro-ocular model of herpetic infection was used to study ICP0 gene expression in the major anatomical sites of HSV-1 latency, including the TG, superior cervical ganglion, spinal cord, and hypothalamus. An HSV-1 recombinant strain, SC16 110LacZ, revealed ICP0 promoter activity in several neurons in latently infected ganglia, and following infection with wild-type HSV-1 strain SC16, in situ hybridization analyses identified ICP0 transcripts in the nuclei of neurons at times consistent with the establishment of latency. Reverse transcription (RT)-PCR assays performed on RNA extracted from latently infected tissues indicated that ICP0 transcripts were detected in all anatomical sites of viral latency. Furthermore, quantitative real-time RT-PCR showed that neurons differentially expressed the LATs and ICP0 transcripts, with splicing of ICP0 transcripts being dependent on the anatomical location of latency. Finally, TG neurons were characterized by high-level expression of LATs and detection of abundant unspliced ICP0 transcripts, a pattern markedly different from those of other anatomical sites of HSV-1 latency. These results suggest that LATs might be involved in the maintenance of HSV-1 latency through the posttranscriptional regulation of ICP0 in order to inhibit expression of this potent activator of gene expression during latency.
- Published
- 2006
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80. Conformal radiotherapy, reduced boost volume, hyperfractionated radiotherapy, and online quality control in standard-risk medulloblastoma without chemotherapy: results of the French M-SFOP 98 protocol.
- Author
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Carrie C, Muracciole X, Gomez F, Habrand JL, Benhassel M, Mege M, Mahé M, Quetin P, Maire JP, Soum F, Baron MH, Clavere P, Chapet S, Gaci Z, Kolodie H, Maingon P, Vie B, Bernier V, Alapetite C, Hoffstetter S, Grill J, and Lafay F
- Subjects
- Adolescent, Child, Cognition, Dose Fractionation, Radiation, Feasibility Studies, France, Humans, Neoplasm Recurrence, Local, Pilot Projects, Quality Control, Survival Analysis, Treatment Outcome, Cerebellar Neoplasms radiotherapy, Medulloblastoma radiotherapy, Radiotherapy, Conformal methods
- Abstract
Purpose: Between December 1998 and October 2001, patients <19 years old were treated for standard-risk medulloblastoma according to the Medulloblastome-Société Française d'Oncologie Pédiatrique 1998 (M-SFOP 98) protocol. Patients received hyperfractionated radiotherapy (36 Gy in 36 fractions) to the craniospinal axis, a boost with conformal therapy restricted to the tumor bed (to a total dose of 68 Gy in 68 fractions), and no chemotherapy. Records of craniospinal irradiation were reviewed before treatment start., Results: A total of 48 patients were considered assessable. With a median follow-up of 45.7 months, the overall survival and progression-free survival rate at 3 years was 89% and 81%, respectively. Fourteen major deviations were detected and eight were corrected. No relapses occurred in the frontal region and none occurred in the posterior fossa outside the boost volume. Nine patients were available for volume calculation without reduction of the volume irradiated. We observed a reduction in the subtentorial volume irradiated to >60 Gy, but a slight increase in the volume irradiated to 40 Gy. No decrease in intelligence was observed in the 22 children tested during the first 2 years., Conclusion: This hyperfractionated radiotherapy protocol with a reduced boost volume and without chemotherapy was not associated with early relapses in children. Moreover, intellectual function seemed to be preserved. These results are promising.
- Published
- 2005
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81. Development of a PCR-and hybridization-based assay (PCR Adenovirus Consensus) for the detection and the species identification of adenoviruses in respiratory specimens.
- Author
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Vabret A, Gouarin S, Joannes M, Barranger C, Petitjean J, Corbet S, Brouard J, Lafay F, Duhamel JF, Guillois B, and Freymuth F
- Subjects
- Adenoviruses, Human classification, Child, Humans, Immunoenzyme Techniques methods, Immunoenzyme Techniques statistics & numerical data, Polymerase Chain Reaction statistics & numerical data, Predictive Value of Tests, Sensitivity and Specificity, Serotyping, Species Specificity, Adenovirus Infections, Human diagnosis, Adenovirus Infections, Human virology, Adenoviruses, Human genetics, Adenoviruses, Human isolation & purification, Nucleic Acid Hybridization methods, Polymerase Chain Reaction methods, Respiratory Tract Infections diagnosis, Respiratory Tract Infections virology
- Abstract
Background: Antigen detection assays and viral isolation techniques are routinely used to detect adenoviruses (Ad) associated with respiratory infections, and the value of the polymerase chain reaction (PCR) has recently been assessed., Objectives: This paper describes a PCR-hybridization-immunoenzymatic assay (PCR Adenovirus consensus) used to detect Ad and identify Ad species in respiratory specimens., Results: On seven representative serotypes Ad 12, Ad 3, Ad 7, Ad 11, Ad 1, Ad 8, Ad 4, the mean genome equivalents per ml and the mean 50% infectious doses per ml were 10(6.3)and 10(4), respectively. Using 362 nasal aspirates from children, Ad were detected by immunofluorescence (IF) and culture in 97 cases (27%), by the PCR-Ad hexon method in 107 cases (29.5%) and by the PCR Adenovirus Consensus method in 113 cases (31.2%); 13 samples were found positive by both PCR and negative by the IF and culture methods; five samples were only positive according to the PCR Adenovirus Consensus) method. The sensitivity, specificity, predictive positive value and predictive negative value of the PCR Adenovirus Consensus method were 97.9%, 93.2%, 84%, 99.1%, respectively. The method identified the species (sp) from 91 positive amplicons: 1 Ad sp A, 44 Ad sp B, 42 Ad sp C, 3 Ad sp E, and 1 Ad sp F; 85 isolates were identified by IF or the neutralisation in culture, and 86 by a PCR-RE digestion method. The PCR Adenovirus Consensus detected six positive samples that were negative according to the IF and culture methods, and it identified the precise species of nine IF-positive and culture-negative nasal aspirates., Conclusion: The PCR Adenovirus Consensus technique is more efficient than the classical IF or culture techniques for the detection of Ad in respiratory samples. An internal control is included to validate the screening results, and specific probes are used to identify the Ad species.
- Published
- 2004
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82. HSV1 latency sites after inoculation in the lip: assessment of their localization and connections to the eye.
- Author
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Labetoulle M, Maillet S, Efstathiou S, Dezelee S, Frau E, and Lafay F
- Subjects
- Animals, Antigens, Viral analysis, Brain Stem virology, Ciliary Body innervation, Ciliary Body virology, Cornea innervation, Cornea virology, Eye Infections, Viral pathology, Facial Nerve virology, Female, Ganglia virology, Herpes Simplex pathology, Immunoenzyme Techniques, In Situ Hybridization, Iris innervation, Iris virology, Lip innervation, Mice, Mice, Inbred BALB C, Neural Pathways pathology, Retina virology, beta-Galactosidase metabolism, Eye Infections, Viral virology, Herpes Simplex virology, Herpesvirus 1, Human physiology, Lip virology, Neural Pathways virology, Virus Latency physiology
- Abstract
Purpose: To localize the sites of HSV1 latency in mice after a primary infection induced by injection into the lip and to assess their connection to the eye., Methods: The SC16 strain of HSV1, or a recombinant virus containing the HSV1 latency-associated transcript (LAT)-promoter driving expression of the LacZ reporter gene, were injected into the left upper lip. Tissues from animals killed at 6, 28, 180, and 720 days postinoculation (dpi) were analyzed for LATs, either by in situ hybridization (ISH) or by identifying LAT-promoter-driven transgene expression. HSV1 antigens were detected by immunochemistry., Results: At 28 dpi, all the neurologic structures that were acutely infected at 6 dpi exhibited a pattern of virus gene expression consistent with HSV1 latency--that is, LATs with no detectable HSV1 antigens. LAT staining differed among structures: intense and widespread within trigeminal neurons, intermediate within the sympathetic intermediolateral cell group of the spinal cord and the facial motor nucleus, and weak in other sites. Long-term expression of LATs (positive at 180 and 720 days) was observed only in tissues where the staining was intense or intermediate at 28 dpi., Conclusions: After inoculation into the upper lip of mice, HSV1 established latency in several nervous system structures that have direct or indirect connections with ocular tissues. These results suggest that after an oral primary infection, the most frequent in humans, HSV1 may establish latency in several sites connected to the eye and may finally result in herpetic ocular disease involving the cornea, the iris, or even the retina.
- Published
- 2003
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- View/download PDF
83. Neuronal propagation of HSV1 from the oral mucosa to the eye.
- Author
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Labetoulle M, Kucera P, Ugolini G, Lafay F, Frau E, Offret H, and Flamand A
- Subjects
- Animals, Brain Stem virology, Ciliary Body innervation, Ciliary Body virology, Cricetinae, Eye Infections, Viral pathology, Facial Nerve virology, Female, Herpes Simplex pathology, Herpesvirus 1, Human isolation & purification, Iris innervation, Iris virology, Mice, Mice, Inbred BALB C, Mouth Mucosa pathology, Mouth Mucosa virology, Time Factors, Trigeminal Ganglion virology, Uveitis, Anterior pathology, Eye Infections, Viral virology, Herpes Simplex virology, Herpesvirus 1, Human physiology, Mouth Mucosa innervation, Neural Pathways virology, Superior Cervical Ganglion virology, Uveitis, Anterior virology, Virus Replication physiology
- Abstract
Purpose: To identify possible neuronal pathways leading to herpetic ocular disease after primary oral infection in mice., Methods: The SC16 strain of herpes simplex virus (HSV)-1 (10(6) plaque-forming units) was injected into the mucocutaneous border of the left upper lip. Animals were killed 2 to 10 days postinoculation (DPI). Spread of the virus in neural structures was studied by immunochemistry., Results: HSV1 first replicated at the site of inoculation and then at the superior cervical ganglion (at 2 DPI). The trigeminal ganglion and the facial nerve fibers were infected by 4 DPI. Infection of the ciliary body and iris occurred at 6 DPI, together with several brain stem nuclei belonging to the autonomic or sensory pathways. Between 8 and 10 DPI, the neural infection gradually cleared up, except for the ipsilateral sympathetic ganglion, and ipsilateral keratitis appeared in some animals., Conclusions: The pattern of viral dissemination in this mouse model suggests that infection of iris and ciliary body results from transfer of virus in the superior cervical ganglion from sympathetic neurons innervating the lip to neighboring neurons innervating the anterior uvea. Later, zosteriform spread of virus from the trigeminal system may have contributed to the clinical and histologic findings.
- Published
- 2000
84. Neuronal pathways for the propagation of herpes simplex virus type 1 from one retina to the other in a murine model.
- Author
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Labetoulle M, Kucera P, Ugolini G, Lafay F, Frau E, Offret H, and Flamand A
- Subjects
- Animals, Autonomic Pathways virology, Ciliary Body virology, Disease Models, Animal, Female, Iris virology, Mice, Mice, Inbred BALB C, Neurons virology, Optic Nerve virology, Visual Pathways virology, Eye Infections, Viral virology, Herpes Simplex virology, Herpesvirus 1, Human physiology, Retinitis virology
- Abstract
Herpetic retinitis in humans is characterized by a high frequency of bilateral localization. In order to determine the possible mechanisms leading to bilateral retinitis, we studied the pathways by which herpes simplex virus type 1 (HSV-1) is propagated from one retina to the other after intravitreal injection in mice. HSV-1 strain SC16 (90 p.f.u.) was injected into the vitreous body of the left eye of BALB/c mice. Animals were sacrificed 1, 2, 3, 4 and 5 days post-inoculation (p.i.). Histological sections were studied by immunochemical staining. Primary retinitis in the inoculated eye (beginning 1 day p.i.) was followed by contralateral retinitis (in the uninoculated eye) starting at 3 days p.i. Infected neurons of central visual pathway nuclei (lateral geniculate nuclei, suprachiasmatic nuclei and pretectal areas) were detected at 4 days p.i. Iris and ciliary body infection was minimal early on, but became extensive thereafter and was accompanied by the infection of connected sympathetic and parasympathetic pathways. The pattern of virus propagation over time suggests that the onset of contralateral retinitis was mediated by local (non-synaptic) transfer in the optic chiasm from infected to uninfected axons of the optic nerves. Later, retinopetal transneuronal propagation of the virus from visual pathways may have contributed to increase the severity of contralateral retinitis.
- Published
- 2000
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- View/download PDF
85. [Conformational radiotherapy with multi-leaf collimators: one year experience at the Leon-Berard Centre].
- Author
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Ginestet C, Malet C, Lafay F, Dupin G, Chavand B, and Carrie C
- Subjects
- Dose-Response Relationship, Radiation, Female, Humans, Male, Quality Assurance, Health Care, Radiotherapy Dosage, Neoplasms radiotherapy, Particle Accelerators instrumentation, Radiotherapy Planning, Computer-Assisted, Radiotherapy, High-Energy instrumentation, Radiotherapy, High-Energy methods
- Abstract
Taking advantage of the renewal of a linear accelerator, the Radiation Therapy Department of the Centre Léon Bérard implemented, in collaboration with Philips Systèmes Médicaux, a conformal therapy set-up procedure using CT-scan for 3D treatment planning and a multileaf collimator that allows achievement of numerous irregular-shaped beams via the multileaf preparation system. The various elements of this equipment make possible well defined and structured procedures for treatment planning with different steps and essential tools used by this technique. We describe the means used and indicate future improvements that will lead to automation in order to provide good quality assurance, better security and substantial time saving. During the first year, 115 patients were treated with this new technique. They presented with central nervous system tumors (32 patients), lung cancer (29 patients), prostate cancer (20 patients), paranasal sinus tumors (14 patients) and tumors located in other sites (13 patients with soft sarcoma, hepato-bilary tumor, etc).
- Published
- 1997
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- View/download PDF
86. Monoclonal antibodies which recognize the acidic configuration of the rabies glycoprotein at the surface of the virion can be neutralizing.
- Author
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Raux H, Coulon P, Lafay F, and Flamand A
- Subjects
- Amino Acid Sequence, Animals, Antibody Specificity, DNA Mutational Analysis, Epitopes chemistry, Epitopes immunology, Female, Glycoproteins chemistry, Glycoproteins genetics, Hydrogen-Ion Concentration, Mice, Molecular Sequence Data, Mutation physiology, Neutralization Tests, Rabies virus pathogenicity, Viral Envelope Proteins chemistry, Viral Envelope Proteins genetics, Virion immunology, Antibodies, Monoclonal immunology, Antibodies, Viral immunology, Antigens, Viral, Glycoproteins immunology, Protein Conformation, Rabies virus immunology, Viral Envelope Proteins immunology
- Abstract
Around 15% of our anti-glycoprotein monoclonal antibodies (MAbs) failed to neutralize the infectivity of the rabies virus during a 1-hr incubation at room temperature. In previous studies, we have demonstrated that it is possible to induce a massive conformational change of the glycoprotein population by incubating the virus at acidic pH. The conformational change is reversible and consequently viral infectivity is not affected by transient exposure at acidic pH. The proportion of glycoproteins in acidic or neutral configuration depends on the pH which means that even at neutral pH some glycoproteins transiently adopt the acidic configuration and vice versa. Here we report that some of our nonneutralizing MAbs recognize the acidic form of the glycoprotein at the virion surface. After incubation of the virus at pH 6.4, most glycoproteins are in the acidic configuration. Further 1-hr incubation with these MAbs at the same pH resulted in more immunoglobulins being attached to the virus and consequently neutralization was induced. It was also possible to induce neutralization with the same MAbs by incubation at neutral pH for a longer period or at a higher temperature. Mutants resistant to neutralization by these MAbs could be selected. Mutations confering resistance to neutralization were not localized in previously described antigenic sites and did not modify these sites at distance. They had no effect on the pathogenic power of the virus. Either they are situated in the epitope or they modify the epitope, so that it is no longer recognized by the antibody on the acidic configuration of the protein. Alternatively, these mutations may stabilize the protein in its neutral configuration. In addition, these experiments confirm our previous finding that neutralization requires the fixation of a large number of immunoglobulins on the virus, irrespective of the region of the protein recognized by the antibody.
- Published
- 1995
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87. Vaccination against rabies: construction and characterization of SAG2, a double avirulent derivative of SADBern.
- Author
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Lafay F, Bénéjean J, Tuffereau C, Flamand A, and Coulon P
- Subjects
- Animals, Animals, Suckling, Brain, Cell Line, Female, Injections, Injections, Intramuscular, Mice, Mutation, Polymerase Chain Reaction, Vaccines, Attenuated genetics, Vaccines, Attenuated immunology, Rabies Vaccines genetics, Rabies Vaccines immunology
- Abstract
A double avirulent mutant was isolated from the SADBern strain of rabies virus by two successive selection steps using neutralizing anti-glycoprotein monoclonal antibodies. Both mutations affect the triplet coding for amino acid 333 of the glycoprotein. The resulting virus, called SAG2, has a glutamate coded by GAA in position 333 instead of an arginine. This new codon differs by two nucleotides from all the arginine triplets. SAG2 is avirulent in adult mice by intracerebral and intramuscular routes and it protects mice against a challenge by the CVS strain. This double mutant is still avirulent after three successive passages in suckling mouse brain or after ten successive cycles of multiplication in cell culture. Because it is protective and genetically stable, SAG2 represents an improvement on SAG1 which is already used for oral vaccination of foxes in Switzerland and France. It could also be a candidate for oral vaccination of dogs against rabies.
- Published
- 1994
- Full Text
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88. The molecular basis for altered pathogenicity of lyssavirus variants.
- Author
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Coulon P, Lafay F, Tuffereau C, and Flamand A
- Subjects
- Amino Acid Sequence, Glycoproteins immunology, Molecular Sequence Data, Mutation, Rabies Vaccines immunology, Rabies virus genetics, Rabies virus immunology, Viral Envelope Proteins immunology, Rabies virus pathogenicity
- Published
- 1994
- Full Text
- View/download PDF
89. SAG-2 oral rabies vaccine.
- Author
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Schumacher CL, Coulon P, Lafay F, Bénéjean J, Aubert MF, Barrat J, Aubert A, and Flamand A
- Subjects
- Animals, Cats, Dogs, Foxes, Mice, Rabies prevention & control, Rabies Vaccines therapeutic use, Rabies virus genetics, Rabies virus pathogenicity, Vaccines, Attenuated biosynthesis, Vaccines, Attenuated therapeutic use, Virulence, Rabies veterinary, Rabies Vaccines biosynthesis, Vaccination veterinary
- Abstract
The live modified rabies virus vaccine strain SAG-2 was selected from SADBerne in a two step process employing anti-rabies glycoprotein monoclonal antibodies. The first two nucleotides coding for the amino acid in position 333 of the rabies glycoprotein are mutated. Arginine at position 333, which is associated with rabies pathogenicity, was substituted first by lysine and then by glutamic acid. The two nucleotide differences at position 333 in SAG-2 to any of six possible arginine triplets translated into excellent genetic stability and apathogenicity for adult mice, foxes, cats and dogs. The vaccination of foxes and dogs by the oral route provided protection against a lethal challenge with rabies virus.
- Published
- 1993
90. Rabies virus antigenicity: an overview.
- Author
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Coulon P, Lafay F, and Flamand A
- Subjects
- Amino Acid Sequence, Animals, Antibodies, Monoclonal, RNA, Viral genetics, Rabies virus genetics, Epitopes chemistry, Rabies virus immunology
- Published
- 1993
91. Avirulent mutants of rabies virus and their use as live vaccine.
- Author
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Flamand A, Coulon P, Lafay F, and Tuffereau C
- Subjects
- Animals, Europe, Glycoproteins toxicity, Mutation, Vaccination, Vaccines, Attenuated immunology, Virulence, Animals, Wild, Rabies Vaccines immunology, Rabies virus genetics
- Abstract
Oral vaccination of foxes against rabies began in Switzerland some 20 years ago and was later extended to several European countries. The vaccine strains, which were derivatives of the SAD strain of rabies, retain a non-negligible pathogenicity for rodents and nontarget species. Antigenic mutants of the SAD Bern vaccine strain, which are avirulent for adult mice, foxes and dogs, have been isolated and are presently under trial.
- Published
- 1993
- Full Text
- View/download PDF
92. Envelope proteins of vesicular stomatitis virus: effect of temperature-sensitive mutations in complementation groups III and V.
- Author
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Lafay F
- Subjects
- Amino Acids metabolism, Animals, Cell Fractionation, Centrifugation, Density Gradient, Chick Embryo, Culture Techniques, Cytoplasm analysis, Electrophoresis, Polyacrylamide Gel, Genetic Complementation Test, Leucine metabolism, Temperature, Tritium, Vesicular stomatitis Indiana virus metabolism, Mutation, Vesicular stomatitis Indiana virus analysis, Viral Proteins analysis, Viral Proteins biosynthesis
- Abstract
All five major viral proteins were synthesized in chicken embryo cells infected with vesicular stomatitis virus temperature-sensitive (ts) mutants of complementation groups III and V and maintained at the nonpermissive temperature. The distribution of these proteins among cytoplasmic cellular fractions separated on discontinuous sucrose gradients was identical for wild-type and tsIII-infected cells. Strikingly different patterns were observed for the G protein in gradients from cells infected by tsV mutants; very little, if any, G protein was found in the lightest fraction. Pulse and chase experiments with wild-type, virus-infected cells showed that protein G moves from the heaviest to the lightest fraction before being incorporated into the virion. After shift down to the permissive temperature (30 C), G protein synthesized at 39.6 C in tsV-infected cells became associated with the lightest cellular fraction and later with the released virions. In contrast, M protein, synthesized at 39.6 C in tsIII-infected cells, was not incorporated into the virions after shift down. These data strongly suggest, first, that M protein is encoded by the vesicular stomatitis gene III, and second, that incorporation of G protein in the lightest cellular fraction is a necessary step of vesicular stomatitis maturation. This step is impaired by tsV mutations.
- Published
- 1974
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93. [Primitive megalencephaly with growth retardation and deficiency in growth hormone (author's transl)].
- Author
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Perelman R, Nathanson M, Lepastier G, and Lafay F
- Subjects
- Child, Child Development, Child, Preschool, Growth Disorders blood, Humans, Intelligence, Male, Brain abnormalities, Growth Disorders complications, Growth Hormone deficiency
- Published
- 1979
94. Temperature sensitive mutants of vesicular stomatitis virus: tryptic peptide maps of the proteins modified in complementation groups II and IV.
- Author
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Lafay F and Benejean J
- Subjects
- Genetic Complementation Test, Mutation, Peptides analysis, Temperature, Trypsin, Vesicular stomatitis Indiana virus analysis, Viral Proteins analysis, Genes, Viral, Vesicular stomatitis Indiana virus genetics, Viral Proteins genetics
- Published
- 1981
- Full Text
- View/download PDF
95. [Complete correction of Fallot's tetralogy in infants. Preliminary results].
- Author
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Landau JF, Lafay F, Batisse A, Kachaner J, Marchand M, Hazan E, and Neveux JY
- Subjects
- Age Factors, Cardiac Catheterization, Electrocardiography, Extracorporeal Circulation, Female, Follow-Up Studies, Humans, Infant, Infant, Newborn, Male, Methods, Postoperative Care, Tetralogy of Fallot mortality, Tetralogy of Fallot surgery
- Abstract
Complete repair was undertaken in 28 infants with severe forms of tetralogy of Fallot because severe cyanosis or anoxic spells. Age at operation ranged from 8 days to 11 months (mean: 4,4 months). Among the 24 cases without any other intracardiac defect, there were 6 early deaths related in 4 cases to a wrong indication or a technical error. Re-investigation was performed in 14 out of the 18 survivors from 3 weeks to 6 months post-operatively: the result is good in 10 cases, fair in 1 case, and poor in 3 cases requiring twice a reoperation with 1 further death and 1 good final result. More accuracy in selecting the surgical patients and improvement in operative techniques should result in a further decrease of our early mortality rate. Primary complete repair should therefore become a substantial alternative to the palliative shunts which results seem to be hazardous in the more severe types of the defect.
- Published
- 1979
96. [A case of generalized reaction to BCG vaccine without apparent immunodeficiency and a fatal outcome].
- Author
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Perelman R, Danis F, Nathanson M, Lafay F, Garcia J, and Fischer A
- Subjects
- Cicatrix, Fatal Outcome, Hospitalization, Humans, Infant, Male, BCG Vaccine adverse effects, BCG Vaccine therapeutic use
- Published
- 1979
97. [A case of generalized reaction to BCG vaccine without apparent immunodeficiency and a fatal outcome (author's transl)].
- Author
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Perelman R, Danis F, Nathanson M, Lafay F, Garcia J, and Fischer A
- Subjects
- Humans, Infant, Newborn, Male, Skin pathology, BCG Vaccine adverse effects, Immunity, Immunologic Deficiency Syndromes diagnosis
- Abstract
No immunodeficiency could be found in a case of generalized BCG infection. The therapeutic trials were unsuccessful, and the child died at the age of 19 months.
- Published
- 1980
98. Tryptic peptide map analyses of mouse transplantation antigens.
- Author
-
Lafay F, Ewald SJ, McMillan M, Frelinger JA, and Hood L
- Subjects
- Amino Acids, Animals, Arginine, Chemical Precipitation, Chromatography, Ion Exchange, H-2 Antigens, Mice, Mice, Inbred A, Mice, Inbred C3H, Histocompatibility Antigens analysis, Peptides genetics, Trypsin pharmacology
- Abstract
Tryptic peptide map analyses of five K- and three D-gene products of various H-2 haplotypes are presented. These data support earlier sequence studies and demonstrate that the variations in allelic gene products of the K or D loci are scattered throughout much of the polypeptide chains. Furthermore, the K allelic gene products are no more closely related to one another than they are to the D allelic gene products. This apparent lack of K-ness and D-ness places interesting constraints on the genetic organization and evolutionary history of the genes encoding the transplantation antigens.
- Published
- 1981
- Full Text
- View/download PDF
99. [Electronic amplifier of x-ray images].
- Author
-
LAFAY F
- Subjects
- Humans, X-Rays, Amplifiers, Electronic, Electronics, Radiography instrumentation
- Published
- 1954
100. [MEASUREMENT AND RECORDING OF PRESSURE AND CARDIAC OUTPUT BY THE RADIOACTIVE TRACER METHOD].
- Author
-
LAFAY F
- Subjects
- Humans, Blood Pressure Determination, Cardiac Output, Heart Function Tests, Pressure, Radioactive Tracers, Radiometry, Serum Albumin, Serum Albumin, Radio-Iodinated
- Published
- 1964
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