37 results on '"Denis Flipo"'
Search Results
2. Phagocytosis Functional Assay
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Herman J. Boermans, Helen Tryphonas, Barry Blakley, Patrice Lapierre, Pauline Brousseau, Yves Payette, Martin Beaudet, Denis Flipo, Isabelle Voccia, Michel Fournier, and Edouard Kouassi
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Functional assay ,Biochemistry ,Chemistry ,Phagocytosis - Published
- 2021
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3. Mixed Lymphocyte Reaction (MLR)
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Isabelle Voccia, Pauline Brousseau, Herman J. Boermans, Patrice Lapierre, Helen Tryphonas, Denis Flipo, Martin Beaudet, Barry Blakley, Michel Fournier, Edouard Kouassi, and Yves Payette
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Chemistry ,Mixed lymphocyte reaction ,Molecular biology - Published
- 2021
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4. Apoptosis
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Pauline Brousseau, Yves Payette, Helen Tryphonas, Barry Blakley, Herman Boermans, Denis Flipo, Michel Fournier, Martin Beaudet, Edouard Kouassi, Patrice Lapierre, and Isabelle Voccia
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- 2021
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5. Collection of Peripheral Blood Samples
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Yves Payette, Helen Tryphonas, Michel Fournier, Herman J. Boermans, Barry Blakley, Edouard Kouassi, Isabelle Voccia, Denis Flipo, Patrice Lapierre, Pauline Brousseau, and Martin Beaudet
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Pathology ,medicine.medical_specialty ,business.industry ,Medicine ,business ,Peripheral blood - Published
- 2021
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6. Manual of Immunological Methods
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Pauline Brousseau, Yves Payette, Helen Tryphonas, Barry Blakley, Herman Boermans, Denis Flipo, Michel Fournier, Martin Beaudet, Edouard Kouassi, Patrice Lapierre, and Isabelle Voccia
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Pathology ,medicine.medical_specialty ,Chromatography ,medicine.diagnostic_test ,Acridine orange ,Biology ,Peripheral blood mononuclear cell ,Cryopreservation ,Flow cytometry ,chemistry.chemical_compound ,chemistry ,medicine ,Peripheral blood cell ,Trypan blue ,Viability assay ,Intracellular - Abstract
Identification, Anaesthesia, and Euthanasia Identification of Laboratory Rodents by Ear Notching Identification of Fish by Fin Clipping Anaesthesia of Fish and Rodents Euthanasia of Rodents Euthanasia of Fish Working Sheet: Weight of Laboratory Animals Collection of Peripheral Blood Samples Reagents Materials and Equipment Procedure Removal of Organs Reagents Materials and Equipment Procedure Preparation of Cell Suspensions Extrusion of Coelomocytes in the Earthworm Hemocyte Collection in the Mollusk Cell Suspension from Peritoneal Exudate Isolation of White Blood Cells from Peripheral Blood Cell Suspensions from Lymphoid Organs Assessment of Cell Viability Determination of Cell Viability and Concentration by Trypan Blue Dye Exclusion Determination of Cell Viability and Cell Concentration with Ethidium Bromide and Acridine Orange Flow Cytometric Assessment of Cell Viability Working Sheet: Cell Viability and Concentration by Trypan Blue Dye Exclusion or Ethidium Bromide/Acridine Orange Cell Cryopreservation Reagents Materials and Equipment Procedure Special Recommendations Analysis of Results Species-Related Changes in the Protocol Technique-Related Changes in the Protocol: Phagocytosis with Yeast Statistical Tests Working Sheet: Phagocytic Function Oxidative Burst Assay Using Flow Cytometry Reagents Materials and Equipment Procedure Special Recommendations Analysis of Results Species-Related Changes in the Protocol Statistical Tests Working Sheet: Acquisition List Cell Cytotoxicity Natural Killer (NK) Cell Activity Antibody-Dependent Cellular Cytotoxicity Lymphokine-Activated Killer (LAK) Working Sheet: Acquistion List Lymphoblastic Transformation Reagents Materials and Equipment Procedure Analysis of Result Special Recommendations Species-Related Changes in the Protocol Working Sheet: Mitogenic Assay Determination of Antibody-Producing Cells to a Specific Antigen Liquid Plaque Forming Cell Assay in Mouse Model Agar Plaque Forming Cell Assay in Rat Model Working Sheet: Plaque Forming Cells (PFC) Mixed Lymphocyte Reaction (MLR) Reagents Materials and Equipment Procedure Analysis of Results Special Recommendations Species-Related Changes in the Protocol Working Sheet: Mixed Lymphocyte Reaction Intracellular Levels of Calcium Assay Using Flow Cytometry Reagents Materials and Equipment Procedure Special Recommendations Analysis of Results Species-Related Changes in the Protocol Statistical Tests Working Sheet: Acquisition List Phenotyping of Blood Mononuclear Cells Reagents Materials and Equipment Procedure Special Recommendations Analysis of Results Species-Related Changes in the Protocol Immunophenotype of Rat Peripheral Blood Lymphocytes Working Sheet Evaluation of Intracellular Level of Thiols Reagents Materials and Equipment Procedure Special Recommendations Analysis of Results Species-Related Changes in the Protocol Working Sheet: Acquisition List Apoptosis Reagents Materials and Equipment Procedure Analysis of Results
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- 2021
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7. Identification, Anesthesia, and Euthanasia
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Edouard Kouassi, Helen Tryphonas, Barry Blakley, Isabelle Voccia, Martin Beaudet, Yves Payette, Denis Flipo, Michel Fournier, Herman J. Boermans, Pauline Brousseau, and Patrice Lapierre
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business.industry ,Anesthesia ,Medicine ,Identification (biology) ,business - Published
- 2021
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8. Cell Cryopreservation
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Pauline Brousseau, Yves Payette, Helen Tryphonas, Barry Blakley, Herman Boermans, Denis Flipo, Michel Fournier, Martin Beaudet, Edouard Kouassi, Patrice Lapierre, and Isabelle Voccia
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- 2021
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9. Assessment of Cell Viability
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Denis Flipo, Michel Fournier, Herman J. Boermans, Patrice Lapierre, Yves Payette, Martin Beaudet, Isabelle Voccia, Helen Tryphonas, Barry Blakley, Pauline Brousseau, and Edouard Kouassi
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Viability assay ,Biology ,Cell biology - Published
- 2021
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10. Removal of Organs
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Edouard Kouassi, Isabelle Voccia, Pauline Brousseau, Helen Tryphonas, Barry Blakley, Denis Flipo, Yves Payette, Patrice Lapierre, Herman J. Boermans, Michel Fournier, and Martin Beaudet
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- 2021
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11. Lymphoblastic Transformation
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Pauline Brousseau, Yves Payette, Helen Tryphonas, Barry Blakley, Herman Boermans, Denis Flipo, Michel Fournier, Martin Beaudet, Edouard Kouassi, Patrice Lapierre, and Isabelle Voccia
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- 2021
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12. Determination of Antibody-Producing Cells to a Specific Antigen
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Pauline Brousseau, Yves Payette, Denis Flipo, Herman J. Boermans, Martin Beaudet, Patrice Lapierre, Edouard Kouassi, Michel Fournier, Helen Tryphonas, Barry Blakley, and Isabelle Voccia
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Antigen ,Chemistry ,Antibody-Producing Cells ,Molecular biology - Published
- 2021
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13. Oxidative Burst Assay Using Flow Cytometry
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Denis Flipo, Yves Payette, Patrice Lapierre, Isabelle Voccia, Herman J. Boermans, Michel Fournier, Martin Beaudet, Pauline Brousseau, Helen Tryphonas, Edouard Kouassi, and Barry Blakley
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medicine.diagnostic_test ,Chemistry ,medicine ,Molecular biology ,Respiratory burst ,Flow cytometry - Published
- 2021
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14. Preparation of Cell Suspensions
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Helen Tryphonas, Barry Blakley, Martin Beaudet, Denis Flipo, Herman J. Boermans, Isabelle Voccia, Pauline Brousseau, Yves Payette, Michel Fournier, Edouard Kouassi, and Patrice Lapierre
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medicine.anatomical_structure ,Chemistry ,Cell ,medicine ,Biophysics - Published
- 2021
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15. Phenotyping of Blood Mononuclear Cells
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Denis Flipo, Helen Tryphonas, Herman J. Boermans, Martin Beaudet, Barry Blakley, Pauline Brousseau, Edouard Kouassi, Michel Fournier, Yves Payette, Patrice Lapierre, and Isabelle Voccia
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Chemistry ,Peripheral blood mononuclear cell ,Molecular biology - Published
- 2021
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16. Syncytin proteins incorporated in placenta exosomes are important for cell uptake and show variation in abundance in serum exosomes from patients with preeclampsia
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Caroline Gilbert, Amandine Vargas, Maude Ethier-Chiasson, Shufeng Zhou, Denis Flipo, Benoit Barbeau, and Julie Lafond
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Adult ,Amino Acid Transport System ASC ,Endosome ,Cell ,Endogenous retrovirus ,Cell Communication ,Endosomes ,Pregnancy Proteins ,Biology ,Exosomes ,Biochemistry ,Exosome ,Flow cytometry ,Cell Fusion ,Minor Histocompatibility Antigens ,Pre-Eclampsia ,Western blot ,Pregnancy ,Cell Line, Tumor ,Genetics ,medicine ,Humans ,Choriocarcinoma ,RNA, Small Interfering ,Molecular Biology ,Furin ,Microscopy, Confocal ,Cytotrophoblast ,Symporters ,medicine.diagnostic_test ,Tumor Suppressor Proteins ,Endogenous Retroviruses ,Gene Products, env ,Molecular biology ,Endocytosis ,Microvesicles ,Trophoblasts ,medicine.anatomical_structure ,Uterine Neoplasms ,embryonic structures ,Female ,RNA Interference ,Biotechnology - Abstract
Exosomes are extracellular vesicles that mediate intercellular communication and are involved in several biological processes. The objective of our study was to determine whether endogenous retrovirus group WE, member l (ERVWE1)/syncytin-1 and endogenous retrovirus group FRD, member 1 (ERVFRDE1)/syncytin-2, encoded by human endogenous retrovirus (HERV) envelope (env) genes, are present at the surface of exosomes produced by placenta-derived villous cytotrophoblasts and whether they play a role in cellular uptake of exosomes. In addition, we sought to determine whether these proteins are present in various abundances in serum-derived exosomes from normal pregnant women vs. women with preeclampsia (PE). Isolated exosomes were analyzed for their content by Western blot, a bead-associated flow cytometry approach, and a syncytin-2 ELISA. Binding and uptake were tested through confocal and electron microscopy using the BeWo choriocarcinoma cell line. Quality control of exosome preparations consisted of detection of exosomal and nonexosomal markers. Exosome-cell interactions were compared between cells incubated in the presence of control exosomes, syncytin-1 or syncytin-2-deprived exosomes, or exosomes solely bearing the uncleaved forms of these HERV env proteins. From our data, we conclude that villous cytotrophoblast exosomes are positive for both env proteins and are rapidly taken up by BeWo cells in a syncytin-1- and syncytin-2-dependent manner and that syncytin-2 is reduced in serum-derived exosomes from women with PE when compared to exosomes from normal pregnant women.
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- 2014
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17. Increased susceptibility to mouse hepatitis virus 3 of peritoneal macrophages exposed to dieldrin☆
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Krzystof Krzystyniak, Michel Fournier, Denis Flipo, and Patrice Hugo
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Time Factors ,Enzyme-Linked Immunosorbent Assay ,Biology ,Toxicology ,Virus ,Article ,Microbiology ,Dieldrin ,chemistry.chemical_compound ,Mice ,Mouse hepatitis virus ,Antigen ,Cytopathogenic Effect, Viral ,Phagocytosis ,In vivo ,Animals ,Pharmacology ,Murine hepatitis virus ,Dose-Response Relationship, Drug ,Macrophages ,digestive, oral, and skin physiology ,biology.organism_classification ,Mice, Inbred C57BL ,Cytolysis ,Dose–response relationship ,chemistry ,Immunology ,biology.protein ,Disease Susceptibility ,Antibody - Abstract
Interaction of a single dose (36 mg/kg body wt) of the organochlorine pesticide dieldrin with mouse peritoneal macrophages was examined in C57Bl/6, (C57Bl/6 X A/J)F1, and A/J strains of different genetic resistance to mouse hepatitis virus 3 (MHV3) infection. In vivo studies showed increased susceptibility to MHV3 acute disease of C57Bl/6 and (C57Bl/6 X A/J)F1 animals challenged with the pesticide. Significant decrease of mean time of death in dieldrin-exposed, MHV3-infected susceptible C57Bl/6 mice was observed similarly upon po or ip administration of a single, sublethal dose of dieldrin. In addition, decrease of humoral response to the virus was quantified by determination of anti-MHV3 IgG antibodies in spleen cell supernatant fractions and in blood sera of dieldrin-exposed C57Bl/6 mice. A single dose of dieldrin did not alter the in vivo resistance of A/J animals to acute MHV3 disease. The resistant A/J mice, however, showed increased mortality upon two subsequent exposures to dieldrin followed by infection with high lethal doses of MHV3. Phagocytic activity, cell adherence capacity, and attachment and uptake of 3H-radiolabeled MHV3 by C57Bl/6 peritoneal macrophages were determined by in vitro studies. These affector activities of peritoneal macrophages were slightly decreased or unchanged in cells originating from animals exposed to the pesticide. However, the intrinsic activity of MHV3 restriction appeared to be affected in macrophages derived from dieldrin-treated animals: (i) peritoneal C57Bl/6 macrophages collected from the early phase of acute MHV3 disease contained increased MHV3 antigen and (ii) increased cytolysis was observed after in vitro MHV3 infection of macrophages originating from dieldrin-exposed C57Bl/6 mice.
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- 2004
18. Immunotoxicity of environmentally relevant mixtures of polychlorinated aromatic hydrocarbons with methyl mercury on rat lymphocytes in vitro
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Michel Fournier, Denis Flipo, Charles Brochu, Francine Denizeau, and Felix Olima Omara
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Lipopolysaccharide ,biology ,Health, Toxicology and Mutagenesis ,Lymphocyte ,Molecular biology ,chemistry.chemical_compound ,Thymocyte ,medicine.anatomical_structure ,chemistry ,Concanavalin A ,Environmental chemistry ,Toxicity ,Splenocyte ,medicine ,biology.protein ,Environmental Chemistry ,Cytotoxicity ,Methylmercury - Abstract
The immunosuppressive effects of methyl mercury (MH), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) are well established at high exposure levels but unclear at low exposure levels. We exposed Fischer 344 rat splenocytes, thymocytes, and peripheral blood lymphocytes in vitro for 72 h to MHg (0.1, 2 μg/ml), PCDD/PCDF mixtures (1, 15 pg/ml) of three PCDDs (2,3,7,8-tetrachlorodibenzo-p-dioxin, 1,2,3,7,8-pentachlorodibenzo-p-dioxin, and 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin) and two PCDFs (2,3,7,8-tetrachlorodibenzofuran and 1,2,3,7,8-pentachlorodibenzo-furan), three Aroclor® (1242, 1254, 1260), PCB mixtures (0.01, 0.5 μg/ml), or combinations of MHg/PCB/PCDD/PCDF mixtures Mitogenic responses of lymphocytes to concanavalin A, phytohemagglutinin, or lipopolysaccharide/dextran sulfate were determined by 3H-thymidine uptake; cytotoxicity and intracellular Ca2+ were determined by flow cytometry. Methylmercury (2 μg/ml and PCB/ PCDD/PCDF mixtures with 2 μg/ml MHg decreased the viability of splenocytes to 57 and 40% at 4 and 24 h, respectively. Basal intracellular calcium ion levels were unaffected by the treatments. Methylmercury suppressed the responses of lymphocytes to T and B cell mitogens. All combinations of MHg/PCB/PCDD/PCDF mixtures decreased mitogenic responses to levels similar to those to MHg alone. In contrast, PCB and PCDD/PCDF mixtures did not suppress but augmented responses of splenocytes and peripheral blood lymphocytes to T cell mitogens. Overall, no interactive toxicity was observed with MHg/PCB/PCDD/PCDF mixtures on cytotoxicity and lymphocyte mitogenic responses. Therefore, MHg may pose a greater threat than organochlorines to the mammalian immune system.
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- 1997
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19. Effects of selective serotonin-reuptake inhibitors on proliferation, syncytialization and hormonal differentiation of BeWo human choriocarcinoma cells
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Denis Flipo, Cathy Vaillancourt, J. Thomas Sanderson, and Hélène Clabault
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medicine.medical_specialty ,Endocrinology ,Reproductive Medicine ,business.industry ,Internal medicine ,Choriocarcinoma ,medicine ,Obstetrics and Gynecology ,Serotonin reuptake ,medicine.disease ,business ,Developmental Biology ,Hormone - Published
- 2014
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20. Combined effects of selected insecticides on humoral immune response in mice
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Denis Flipo, Michel Fournier, Krzysztof Krzystyniak, Jacques Bernier, and Denis Girard
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Insecticides ,Immunology ,Pharmacology ,Biology ,Carbofuran ,Mice ,chemistry.chemical_compound ,Dieldrin ,Immune system ,Antigen ,Animals ,Macrophages ,Organophosphate ,Mice, Inbred C57BL ,Immunoglobulin M ,chemistry ,Antibody Formation ,Humoral immunity ,Malathion ,biology.protein ,Female - Abstract
Biological effects data with single insecticides are far more abundant than with mixtures. These data cannot be used directly to predict the effects of insecticide mixtures. Three insecticides of different chemical classes: organochlorine; dieldrin, organophosphate; malathion, and carbamate; carbofuran, previously evaluated for their immunotoxic potential, were selected for studies of combined acute exposure in C57B1/6 inbred mice. The humoral response to sheep red blood cells (SRBC) and the functional activities of peritoneal macrophages, such as phagocytosis of fluorescent beads and presentation of a single protein antigen, avidin, were examined after in vivo exposure of mice to different combinations of the selected pesticides and compared with the vehicle controls. Regarding exposure to single substances, the data confirmed the immunosuppressive potential of dieldrin and carbofuran and the immunopotentiating effect of malathion. Following the acute concomitant exposure to dieldrin/carbofuran mixture, however, values for the parameters of antigen presentation, primary IgM antibody response to SRBC antigen, and macrophage phagocytosis, returned to control or above-control values, indicating a lack of any synergistic or additive effects of the chemicals on the immune response. Thus, it was concluded the dieldrin/carbofuran mixture had an antagonistic effect on the humoral response to SRBC and the macrophage phagocytic activity, in comparison with the action of administration of each of the insecticides alone.
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- 1992
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21. Ploidy level stability of callus tissue, axillary and adventitious shoots of Larix × eurolepis Henry regenerated in vitro
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Denis Flipo, Janet Wyman, Sylvie Laliberte'e, and Nicole Brassard
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fungi ,food and beverages ,Plant Science ,General Medicine ,Biology ,biology.organism_classification ,Basal shoot ,Tissue culture ,Micropropagation ,Callus ,Axillary bud ,Shoot ,Botany ,Genetics ,Larch ,Ploidy ,Agronomy and Crop Science - Abstract
Studies on the ploidy level of conifers in tissue culture are comparatively rare; however, the confirmation of genetic stability is of particular importance when considering the relatively long generation time of most coniferous species. This study focuses on hybrid larch ( Larix × eurolepis Henry) in vitro systems established from vegetative tissue from a mature tree. These systems involve the regeneration of: (1) multiple shoots without a callus phase (both from axillary buds and from adventitious shoot development from in vitro propagated shoots) and (2) callus tissue and shoots regenerated from callus tissue. Both systems have been in culture for over a year. The objective was to test whether one or both of these systems differ in DNA ploidy level from foliar tissue of mother-plant material, using flow cytometric analysis. There was no evidence of polyploidy in any of the samples and only 2C G0/GI peaks were evident. Our results show that the hybrid larch belongs to the group of conifers that remain genetically stable with respect to ploidy levels under in vitro conditions. Thus, over an extensive culture period, both adventitious shoots and shoots regenerated from callus levels under in vitro conditions. Thus, over an extensive culture period, both adventitious shoots and shoots regenerated from callus tissue of hybrid larch, as well as callus tissue itself retain the diploid DNA level of the mother-plant material.
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- 1992
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22. Immunotoxicity of aminocarb
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Marek Rola-Pleszczynski, Krzysztof Krzystyniak, Denis Flipo, Michel Fournier, and Jacques Bernier
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education.field_of_study ,medicine.diagnostic_test ,medicine.drug_class ,Health, Toxicology and Mutagenesis ,Lymphocyte ,Population ,General Medicine ,Biology ,Monoclonal antibody ,Molecular biology ,Flow cytometry ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,Immunity ,Aminocarb ,Toxicity ,Immunology ,medicine ,Bone marrow ,education ,Agronomy and Crop Science - Abstract
The potential immunotoxic effect of the carbamate pesticide aminocarb on murine bone marrow cell subpopulations was evaluated by flow cytometry, C57B1 6 mice were exposed by gavage to sublethal doses of the pesticide and lymphocyte precursors from bone marrow population were stained with PNA lectin and a panel of monoclonal antibodies against cell surface antigens. In regard to the microenvironment-dependent maturation of B lymphocytes, the pesticide effect on the lymphoproliferative potential of bone marrow was assessed by marrow transplantation from aminocarb-exposed donor mice to normal, syngeneic, X-irradiated recipient mice. The sublethal exposure of 0.08–5.0 mg/kg body wt aminocarb to donor animals did not affect regenerating bone marrow in the recipient mice. No marked effect on bone marrow cell number was noted in pesticide-exposed animals. However, a marked shift in surface IgM density on marrow B cells was noted at 0.08 and 0.31 mg/kg body wt aminocarb. This was correlated with decreased cell frequency in G 0 G 1 phase and increased frequency of cells in the S phase of the cell cycle. Thus, altered maturation of B lymphocytes, expressed as a shift in the density of surface IgM on mature B cells and not the lymphocyte count, was related to the direct effect of aminocarb and/or to the pesticide-related changes in bone marrow microenvironment. Overall, exposure to the carbamate pesticide aminocarb activated the cell maturation process in bone marrow.
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- 1990
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23. Immunotoxicological response of the earthworm Lumbricus terrestris following exposure to cement kiln dusts
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Pierre Yves Robidoux, Bertin Trottier, R Massicotte, Denis Flipo, A Mathiot, Sébastien Sauvé, and Michel Fournier
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Cell Survival ,Health, Toxicology and Mutagenesis ,Industrial Waste ,cement kiln dust ,earthworms ,Complex Mixtures ,In Vitro Techniques ,chemistry.chemical_compound ,coelomocytes ,Dichlorofluorescein ,Animals ,Soil Pollutants ,Viability assay ,Food science ,Propidium iodide ,Oligochaeta ,Coelomocyte ,Incubation ,Cells, Cultured ,cell viability ,immunotoxicity ,biology ,Dose-Response Relationship, Drug ,Ecology ,Lumbricus terrestris ,Earthworm ,Public Health, Environmental and Occupational Health ,phagocytosis ,Dust ,General Medicine ,biology.organism_classification ,cytometry ,Pollution ,Cement kiln ,chemistry ,Environmental Monitoring - Abstract
Cement kiln dusts are made of a complex mixture of elements. We have evaluated the potential negative impact of those dusts on the immune system of the earthworm Lumbricus terrestris. We specifically studied cell viability and phagocytic activity of coelomocytes extruded during electrical stimulation. We used two modes of exposures: in vitro, and soil incubation using OECD artificial soil media. Extruded coelomocytes were exposed 18 h in vitro to 10, 100, and 500 mg L-1 of cement kiln dust particles. The phagocytosis and the cell viability were determined using a double-laser-flow acquisition cytometry system. Using the double laser allows us to use a dichlorofluorescein diacetate (DCFDA) marker to discriminate the biological cells from the cement kiln dusts. Dead cells are marked using propidium iodide (PI). All three exposure levels showed highly significant impacts on cell viability and phagocytic activity. The in vivo soil incubation was performed using 10, 100, and 1000 mg kg-1 of cement kiln dusts incorporated into the OECD media. Here, to discriminate the biological cells from the mineral dusts we only needed to use PI. The day-to-day variability of the in vivo assay was high and although we can observe an overall reduction in cell viability at the highest concentration tested, no statistically significant effects could be observed on either cell viability or phagocytosis. Copyright 2004 Elsevier Inc. All rights reserved.
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- 2004
24. Immune response of earthworms (Lumbricus terrestris, Eisenia andrei and Aporrectodea tuberculata) following in situ soil exposure to atmospheric deposition from a cement factory
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Bertin Trottier, Denis Flipo, Sébastien Sauvé, Michel Fournier, Richard Massicotte, and Pierre Yves Robidoux
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In situ ,Eisenia andrei ,Industrial Waste ,Incineration ,Management, Monitoring, Policy and Law ,environmental ,Immune system ,Phagocytosis ,Animals ,Soil Pollutants ,Oligochaeta ,Cement ,Air Pollutants ,Immunity, Cellular ,calcium ,biology ,Chemistry ,Construction Materials ,plants ,Earthworm ,Public Health, Environmental and Occupational Health ,General Medicine ,Environmental exposure ,Environmental Exposure ,Hydrogen-Ion Concentration ,biology.organism_classification ,Deposition (aerosol physics) ,Environmental chemistry ,cells ,hand ,Lumbricus terrestris - Abstract
In order to reduce their energy costs, many cement plants use fuel product substitutes (old tyres and used oil). The combustion of these products generates a metal increase (e.g. Cu, Cd, Pb and Zn) in the atmospheric emissions. After their release, these elements are deposited into the environment and could eventually accumulate up to concentrations of concern. At the Saint-Laurent cement factory (Joliette, QC, Canada), maximum deposition of these elements occurs in the direction of prevailing winds (North-East). We evaluated the potential impact of these depositions upon the immune system of three earthworm species (Lumbricus terrestris, Eisenia andrei and Aporrectodea tuberculata) exposed in a natural environment. The exposure sites were 0.5, 1.0, and 2.0 km downwind from the cement factory, along with an upwind reference site. The immune parameters studied were the cell viability and phagocytic potential of the immune cells (coelomocytes). For both L. terrestris and E. andrei, after 7 d exposure, none of the measured parameters showed significant differences among the sites. On the other hand, for the indigenous worm A. tuberculata, in the most exposed zone (at 0.5 km), we observed an increase in cell viability and phagocytic potential. This increase could possibly be attributed to physicochemical effects such as the alkaline pH of the soil, or alternatively, it could result from beneficial effects induced by an increased calcium supply.
- Published
- 2003
25. Lack of suppressive effects of mixtures containing low levels of methylmercury (MeHg), polychlorinated dibenzo-p-dioxins (PCDDS), polychlorinated dibenzofurans (PCDFS), and aroclor biphenyls (PCBS) on mixed lymphocyte reaction, phagocytic, and natural killer cell activities of rat leukocytes in vitro
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Francine Denizeau, C. Brochu, Edouard F. Potworowski, Felix Olima Omara, Denis Flipo, Pauline Brousseau, and Michel Fournier
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Male ,Aroclors ,Polychlorinated Dibenzodioxins ,Phagocyte ,Cell Survival ,Health, Toxicology and Mutagenesis ,Lymphocyte ,T-Lymphocytes ,Toxicology ,Natural killer cell ,chemistry.chemical_compound ,In vivo ,medicine ,Splenocyte ,Animals ,Soil Pollutants ,Methylmercury ,Benzofurans ,Phagocytes ,Dibenzofurans, Polychlorinated ,Methylmercury Compounds ,Molecular biology ,Polychlorinated Biphenyls ,Rats, Inbred F344 ,Rats ,Killer Cells, Natural ,medicine.anatomical_structure ,chemistry ,Environmental chemistry ,Toxicity ,Lymphocyte Culture Test, Mixed ,Polychlorinated dibenzofurans ,Spleen - Abstract
Rat splenocyte mixed leukocyte reaction (MLR), splenic natural killer (NK) cell activity, and phagocytic activities of splenic, peritoneal, and peripheral blood leukocytes (PBLs) were evaluated in vitro to determine the immunotoxicity of mixtures containing low levels of methylmercury (MeHg), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and Aroclor polychlorinated biphenyls (PCBs). The mixtures were based on the concentrations of the chemicals in fish flesh. Leukocytes from male Fischer rats were exposed to MeHg (0.1-2 microg/ml), PCDD/PCDF mixtures (1-15 pg/ml) of three PCDDs (2,3,7,8-tetrachlorodibenzo-p-dioxin, 1,2,3,7,8-pentachlorodibenzo-p-dioxin, and 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin) and two PCDFs (2,3,7,8-tetrachlorodibenzofuran and 1,2,3,7,8-pentachlorodibenzofuran), three Aroclor PCB (Aroclor 1242, 1254, and 1260) mixtures (0.01-0.5 microg/ml), or combinations of MeHg/PCB/PCDD/PCDF mixtures for 24 or 72 h before immunological assays. Phagocytosis and NK cell cytotoxicity were evaluated with a flow cytometer, and MLR of Fischer rat responder splenocytes cultured with mitomycin C-treated Long-Evans splenocytes by [3H]thymidine uptake. Exposure to MeHg (2 microg/ml) alone or with PCB/ PCDD/PCDF resulted in significant cytolethality in rat splenocytes, peritoneal leukocytes, and PBLs at 24 h exposure. Treatment with Aroclor PCB mixtures, PCDD/PCDF mixtures, 0.1 microg MeHg/ml (noncytolethal), or PCB/PCDD/PCDF mixtures with 0.1 microg MeHg/ml caused no suppression of splenocyte MLR response, splenic NK cell-mediated lysis of Yac-l cells, or phagocytosis of fluorescent beads by splenic, peritoneal, and peripheral blood phagocytic cells. The results indicate that in vitro exposure of rat leukocytes to low levels of MeHg, Aroclor PCB mixtures, PCDD/PCDF mixtures, or MeHg/PCB/PCDD/PCDF mixtures had no suppressive effects on the immune functions assayed, and thus produced no additive immunotoxicity. However, in order to predict the potential risk of these chemical mixtures to the human immune system, in vivo animal studies with blood (tissue) levels compatible with the levels of MeHg, PCBs, and PCDDs/PCDFs in exposed human populations should be evaluated.
- Published
- 1998
26. Effects of Great Lakes fish consumption on the immune system of Sprague-Dawley rats investigated during a two-generation reproductive study
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D.L. Arnold, Stephen Hayward, Helen Tryphonas, F. Bryce, P. McGuire, Michel Fournier, Denis Flipo, and F. Lacroix
- Subjects
Male ,Hydrocortisone ,Animal feed ,Phagocytosis ,T-Lymphocytes ,media_common.quotation_subject ,Lymphocyte ,Spleen ,Food Contamination ,Biology ,Lymphocyte Activation ,Toxicology ,Rats, Sprague-Dawley ,Eating ,Immune system ,Animal science ,Sex Factors ,Oral administration ,Salmon ,White blood cell ,Sprague dawley rats ,medicine ,Animals ,media_common ,Ecology ,Reproduction ,Body Weight ,General Medicine ,Organ Size ,Animal Feed ,Rats ,Killer Cells, Natural ,Red blood cell ,medicine.anatomical_structure ,In utero ,Immune System ,Toxicity ,Immunology ,Leukocytes, Mononuclear ,Gestation ,Female ,Water Pollutants, Chemical - Abstract
The effects of Great Lakes fish contaminants on several quantitative and functional aspects of the immune system were investigated in the first (F1) and second (F2) generations of Sprague-Dawley rats. The F0 rats were fed either a control diet or diets containing 5 or 20% lyophilized chinook salmon from the Credit River of Lake Ontario (LO) and Owen Sound point of Lake Huron (LH). The F1 and F2 pups were exposed to fish in utero, through the dam's milk to 21 days old, and through the dam's respective diets to 13 weeks of age. The study included an F1-reversibility (F1-R) phase in which rats at 13 weeks of exposure to fish or control diets were switched to the control diet for 3 months. The most outstanding finding was a statistically significant increase in absolute spleen leukocytes and absolute and percentage lymphocytes in the F2 male rats fed the LH fish diets compared to the control and to those fed the LO fish diets with the 20% fish diets having higher cell numbers compared to the LO-5% fish diets. A parallel increase in the T-helper/inducer T-lymphocyte subset numbers was observed. Increased but statistically insignificant plaque-forming cell (PFC) numbers were obtained in the F2 male rats fed the LH fish diets compared to those fed the LO fish diets and in the F1-R female group of rats fed the LH fish diet compared to those fed the LO fish diets. Phagocytosis by resident peritoneal macrophages was significantly increased in the F1 male and F2 female rats fed the fish diets compared to the control. The phagocytic activity was significantly higher in the F2-generation male and female rats fed the LO diets compared to those fed the LH diets. Other parameters including lymphocyte transformation in response to mitogens, the number of Listeria monocytogenes bacteria surviving in the rat spleens, and the natural killer cell activity were not affected significantly by any of the treatments. Overall, the effects of diets containing chinook salmon from the LO and LH sources on the immune system of rats were minimal and were on quantitative rather than on functional aspects of the system. Further focused research would be required in order to establish conclusively that the immune system of cohorts who ingest Great Lakes fish frequently is at a greater risk for adverse effects.
- Published
- 1998
27. Increased apoptosis, changes in intracellular Ca2+, and functional alterations in lymphocytes and macrophages after in vitro exposure to static magnetic field
- Author
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Pinsky C, LaBella Fs, Le Boulaire C, Denis Flipo, Krzysztof Krzystyniak, Philippe P. Roux, Benquet C, and Michel Fournier
- Subjects
Interleukin 2 ,Intracellular Fluid ,Health, Toxicology and Mutagenesis ,Lymphocyte ,Spleen ,Apoptosis ,In Vitro Techniques ,Toxicology ,Mice ,Electromagnetic Fields ,Phagocytosis ,medicine ,Macrophage ,Animals ,Lymphocytes ,biology ,Macrophages ,Molecular biology ,Thymocyte ,medicine.anatomical_structure ,Concanavalin A ,Immunology ,biology.protein ,Interleukin-2 ,Calcium ,Intracellular ,medicine.drug - Abstract
Electromagnetic-related alteration of cellular functions is well documented for extremely low-frequency low-energy pulsing electromagnetic fields (ELF-EMF). In this study we examined the in vitro effects of static magnetic fields (SMF) on the cellular immune parameters of the C57BI/6 murine macrophages, spleen lymphocytes, and thymic cells. The cells were exposed in vitro for 24 h at 37 degrees C, 5% CO2, to 250-1500 G SMF. Exposure to the SMF resulted in the decreased phagocytic uptake of fluorescent latex microspheres, which was accompanied by an increased intracellular Ca2+ level in macrophages. Exposure to SMF decreased mitogenic responses in lymphocytes, as determined by incorporation of [3H]thymidine into the cells. This was associated with the increased Ca2+ influx in concanavalin A-stimulated lymphocytes. Furthermore, exposure to SMF produced markedly increased apoptosis of thymic cells, as determined by flow cytometry. Overall, in vitro exposure of immunocompetent cells to 250-1500 G SMF altered several functional parameters of C57BI/6 murine macrophages, thymocytes, and spleen lymphocytes.
- Published
- 1998
28. In vitro lymphotoxicity and selective T cell immunotoxicity of high doses of acyclovir and its derivatives in mice
- Author
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Denis Flipo, Larisa Y. Poluektova, Michel Fournier, Krzysztof Krzystyniak, and Richard Desjardins
- Subjects
Cell Survival ,viruses ,T cell ,T-Lymphocytes ,Immunology ,Population ,Acyclovir ,Biology ,Antiviral Agents ,chemistry.chemical_compound ,Mice ,In vivo ,medicine ,Deoxyguanosine ,Animals ,Phytohemagglutinins ,skin and connective tissue diseases ,Cytotoxicity ,education ,Cells, Cultured ,Pharmacology ,education.field_of_study ,B-Lymphocytes ,Cell growth ,virus diseases ,Molecular biology ,In vitro ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Biochemistry ,chemistry ,Antigens, Surface ,Female ,CD8 ,Spleen - Abstract
The antiviral drug acyclovir [9-(2-hydroxyethoxymethyl)guanine (ACV)], its 7-isomer (7-ACV) and its two derivatives: N2-acetyl ACV (ac-ACV) and N2,O-diacetyl ACV (diac-ACV) were examined for their potential in vitro lymphotoxicity and in vivo immunotoxicity in mice. In vitro lymphotoxicity of ACV and its acetylated derivatives was low, whereas the 7-ACV isomer enhanced the in vitro cell proliferation in PHA-stimulated cultures. Addition of 2'-deoxyguanosine (dGuo) did not exhibit any inhibitory potential of ACV. However, reduction in the absolute number of CD3+, CD8+, and CD25+ cells, but not Ig+ cells, was noted at high concentrations of ACV and its derivatives, suggesting a selective T cell cytotoxicity. Similarly, the in vivo exposure revealed selective T cell immunotoxicity of ACV and its derivatives since the reduced number of Thy 1.2+ and CD8+ cells was not accompanied with any marked changes in the Ig+ population. The CD4+/CD8+ ratio was affected both in vitro and in vivo by high concentrations of ACV.
- Published
- 1996
29. Immune functions in beluga whales (Delphinapterus leucas): evaluation of phagocytosis and respiratory burst with peripheral blood leukocytes using flow cytometry
- Author
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Sylvain De Guise, Jeffrey R. Boehm, Denis Flipo, Pierre Béland, Daniel Martineau, and Michel Fournier
- Subjects
Male ,General Veterinary ,medicine.diagnostic_test ,Neutrophils ,Phagocytosis ,Immunology ,Water Pollution ,Whales ,Biology ,Flow Cytometry ,Peripheral blood ,Respiratory burst ,Flow cytometry ,Immune system ,medicine ,Leukocytes ,Beluga Whale ,Animals ,Female ,Respiratory Burst - Abstract
Flow cytometric assays using peripheral blood were developed to study phagocytosis and respiratory burst, the two major functions of neutrophils and among the most important non-specific defense mechanisms, in beluga whales. The use of flow cytometry avoids the problems associated with the isolation and purification of different cell types, and allows the measurement of a large number of cells (10 000) in a very short period of time. The methods described will be used to compare these functions in blood samples from highly contaminated beluga whales from the St. Lawrence and from relatively clean arctic beluga whales.
- Published
- 1995
30. Cytometric profile of molybdenum-induced contact sensitization versus a strong allergen reaction to oxazolone in murine auricular lymph node (ALN) test
- Author
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Mohamed Abdouh, Hélène-Marie Thérien, Denis Flipo, Krzysztof Krzystyniak, and Michel Fournier
- Subjects
T-Lymphocytes ,Immunology ,Spleen ,Enzyme-Linked Immunosorbent Assay ,Dermatitis, Contact ,Oxazolone ,chemistry.chemical_compound ,Mice ,Immune system ,Immunophenotyping ,Adjuvants, Immunologic ,Phagocytosis ,medicine ,Animals ,Ear, External ,Lymph node ,Sensitization ,Pharmacology ,Molybdenum ,B-Lymphocytes ,Sheep ,Chemistry ,Allergens ,Molecular biology ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Phenotype ,Antibody Formation ,Female ,Lymph ,Lymph Nodes ,CD8 - Abstract
Induction of contact hypersensitivity (CH) by molybdenum chloride (MoCl5) was determined by auricular lymph node (ALN) test in C57B1/6 mice. The ALN test was further improved by immunophenotyping and cytometric analysis of subset-specific cell in the draining node. Skin sensitization was induced by topical ear exposure to 1.0-50% oxazolone and resulted in a strong dose-related ALN reaction. Analogous exposure to MoCl5 resulted in a weaker but marked dose-related reaction, also manifested as an increase in cell number/ALN. Other differences between the oxazolone-induced strong sensitization and the MoCl5-related ALN reaction were: (1) an increase in the total number of Ig+ cells, which was, however, unchanged in the MoCl5-exposed mice; (2) a significant increase in the total number of large/activated T-cell subsets; and (3) a marked shift in the relative percentage of gated large/activated subsets of ALN cells, which was not observed in the MoCl5-exposed animals. Thus, it appeared that the molybdenum exposure induced a nonspecific increase in the cell number/ALN and was not accompanied by any marked activation of the T-cell subsets. Immunotoxicity of a 14 day subchronic exposure to MoCl5 at 1-100 ppm in food was studied by quantification of splenic humoral IgM response to sheep erythrocytes (SRBC). Plaque-forming cells (PFC) and enzyme-linked immunosorbent assay (ELISA) revealed unchanged humoral exposure in MoCl5-exposed mice. Cytometric assay of fluorescent beads uptake showed unchanged phagocytic activity of peritoneal macrophages from the MoCl5-exposed mice. Immunophenotyping of CD4+, CD8+, Thy 1.2+ and Ig+ cells revealed no effect of MoCl5 exposure on the total count of cell subsets in the ungated populations of spleen, lymph nodes and peripheral blood cells. Molybdenum chloride should thus be considered as a non-immunotoxic and a weak, nonspecific contact irritant.
- Published
- 1995
31. In-vitro mercury-related cytotoxicity and functional impairment of the immune cells of rainbow-trout (oncorhynchus-mykiss)
- Author
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Isabelle Voccia, Krzysztof Krzystyniak, Denis Flipo, Michel Fournier, Muriel Dunier, Université de Québec, Unité associée de toxicologie métabolique et d'écotoxicologie, and Institut National de la Recherche Agronomique (INRA)
- Subjects
lymphocytes ,kidney ,blood phagocytes ,mercury ,mice ,Phagocyte ,chloride ,chemical ,cytofluorometry ,leukocytes ,Health, Toxicology and Mutagenesis ,Phagocytosis ,[SDV]Life Sciences [q-bio] ,Environmental pollution ,cytotoxicity immunotoxicity ,010501 environmental sciences ,Aquatic Science ,Pharmacology ,01 natural sciences ,oncorhynchus-mykiss ,03 medical and health sciences ,Immune system ,blood ,mercury methyl mercury ,medicine ,Cytotoxic T cell ,pronephric leukocytes ,oxidative burst ,030304 developmental biology ,0105 earth and related environmental sciences ,Phytohaemagglutinin ,0303 health sciences ,biology ,Chemistry ,toxicity ,mitogenic response ,rainbow trout ,Respiratory burst ,immunotoxicology ,medicine.anatomical_structure ,Biochemistry ,blood leukocytes ,Concanavalin A ,exposure ,biology.protein ,spleen ,flow-cytometry ,environmental pollution - Abstract
Aquat. Toxicol. ISI Document Delivery No.: NX445 Times Cited: 30 Cited Reference Count: 25 Voccia, i krzystyniak, k dunier, m flipo, d fournier, m Elsevier science bv Amsterdam; Cytotoxic and immunotoxic effects of mercury chloride and methylmercury on blood and head kidney leucocytes of rainbow trout (Oncorhynchus mykiss) were evaluated in vitro, for a broad dose range (10(-4)-10(-9) M Hg) of the chemicals. Mercury-related impairment of functional cellular parameters were measured using mixed leucocyte reaction (MLR) and mitogen stimulation of the cells by phytohaemagglutinin (PHA), concanavalin A (Con A) and lipopolysaccharide (LPS). Non-specific defense mechanisms of blood neutrophils and pronephros macrophages were analysed using flow cytometric assay of phagocytosis and respiratory burst. Impairment of the functional cellular activities appeared to be limited almost exclusively to cytotoxic concentrations of the mercurials. Similarly, phagocytic and respiratory burst activities of blood and head kidney phagocytes were markedly impaired by high, cytotoxic concentrations of the mercurials. The in vitro cytotoxic potential of methylmercury; greater-than-or-equal-to 10(-5) M Hg, appeared to be at least ten times higher over the cytotoxicity of mercury chloride greater-than-or-equal-to 10(-4) M Hg. At lower mercury concentrations, the data showed mostly normal- or above-normal values of the assayed functional activities of the cells. Overall, a nonspecific, poisoning-related impairment of leucocyte and phagocyte functions was concluded for the in vitro cytotoxic concentrations of mercurials.
- Published
- 1994
- Full Text
- View/download PDF
32. Fast separation of macrophages by retention on cross-linked amylose and release by enzymatic amylolysis of the chromatographic material
- Author
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Denis Flipo, Richard J.P. Desmangles, Mircea Alexandru Mateescu, and Michel Fournier
- Subjects
Size-exclusion chromatography ,Population ,Fluorescent Antibody Technique ,Cell Separation ,Matrix (biology) ,chemistry.chemical_compound ,Mice ,Amylose ,Polysaccharides ,Ethidium ,Cell Adhesion ,Macrophage ,Animals ,Epichlorohydrin ,education ,chemistry.chemical_classification ,education.field_of_study ,Chromatography ,Macrophages ,General Chemistry ,DNA ,Mice, Inbred C57BL ,Enzyme ,Cross-Linking Reagents ,chemistry ,Biochemistry ,Cell culture ,Chromatography, Gel ,Female ,Fluorescein-5-isothiocyanate - Abstract
Macrophages from mice peritoneal exudate were isolated on basis of specific adherence on epichlorohydrin cross-linked amylose (CLA), a chromatographic gel presenting a high susceptibility to advanced amylolysis with alpha-amylase. The cell suspension, containing predominantly macrophages and lymphocytes, was applied onto the column and incubated for 30 min at 37 degrees C for the adherence of macrophages. After this interval the non-adherent cells were eluted with buffered medium and the CLA support was incubated in the column with an alpha-amylase-buffered solution liquefying the matrix and releasing, in situ, the adherent cell population containing 90% macrophages with a viability higher than 90%.
- Published
- 1992
33. Immune response of earthworms (Lumbricus terrestris, Eisenia andrei and Aporrectodea tuberculata) following in situ soil exposure to atmospheric deposition from a cement factory.
- Author
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Richard Massicotte, Pierre Yves Robidoux, Sébastien Sauvé, Denis Flipo, Michel Fournier, and Bertin Trottier
- Published
- 2003
34. Evaluation of immunotoxicity of combined pesticides in mice
- Author
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Denis Flipo, Jacques Bernier, Michel Fournier, and Krzysztof Krzystyniak
- Subjects
Pharmacology ,business.industry ,Environmental chemistry ,Immunology ,Medicine ,Pesticide ,business - Published
- 1991
- Full Text
- View/download PDF
35. A cytometric approach in immunotoxicology
- Author
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Michel Fournier, F. Denizeau, Denis Flipo, Saad Mansour, P. Brousseau, and Krzysztof Krzystyniak
- Subjects
Pharmacology ,business.industry ,Immunology ,Medicine ,Immunotoxicology ,business - Published
- 1991
- Full Text
- View/download PDF
36. Suppression of avidin processing and presentation by mouse macrophages after sublethal exposure to dieldrin
- Author
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Saas Mansour, Krzysztof Krzystyniak, Denis Flipo, and Michel Fournier
- Subjects
Time Factors ,T-Lymphocytes ,Phagocytosis ,Lymphocyte ,Mice ,Antigen ,Immune Tolerance ,medicine ,Animals ,Macrophage ,Pharmacology ,Dieldrin ,Dose-Response Relationship, Drug ,biology ,Antigen processing ,Macrophages ,Immunogenicity ,Avidin ,Molecular biology ,Mice, Inbred C57BL ,medicine.anatomical_structure ,biology.protein ,Female ,Antibody - Abstract
The molecular events in macrophage antigen processing and presentation were examined to determine the possible site(s) of cell-xenobiotic interaction. Antigenic processing by mouse peritoneal macrophages of a single protein antigen, avidin, was significantly suppressed following sublethal exposure of animals to an organochlorine pesticide, dieldrin. Exposure of C57B1/6 female mice to dieldrin affected the in vitro uptake of [ methyl - 14 C]avidin by peritoneal macrophages and markedly decreased phagocytosis of fluorescein-labelled microspheres and Salmonella typhimurium . Release of the processed avidin, determined by immunochemical quantification of immunogenic avidin and by bioassay of immunogenicity of the released antigen, was also markedly affected. Dieldrin markedly affected presentation of avidin on the macrophage surface, observed by cytoimmunochemical staining of the antigen with fluorescent antibody and flow cytometry. Inhibition of the release of processed avidin was dieldrin dose- and time-dependent, following single sublethal intraperitoneal (ip) exposure to the pesticide. The antigenic properties of processed avidin, determined by biological assay using lymphocyte cultures, for normal C57B1/6 mice primed with avidin, were proportional to the antigen concentration in supernatants of macrophage cultures, for both vehicle controls and dieldrin-exposed animals. This observation and analysis of the kinetics of release of processed avidin by macrophages from control and dieldrin-exposed animals suggested that the release of processed avidin, but not the immunogenicity of the antigen itself, was affected by the pesticide exposure. Generally, impairment of avidin processing and presentation appeared to be more dramatic than other pesticide-related injuries to macrophages, such as the uptake of the antigen. In conclusion, antigen processing could be a sensitive target for dieldrin-related injury of macrophage functional activities, which, in consequence, could produce suppression of the humoral immune response.
- Published
- 1989
- Full Text
- View/download PDF
37. Evaluation of pesticide effects on humoral response to sheep erythrocytes and mouse hepatitis virus 3 by immunosorbent analysis
- Author
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Krzysztof Krzystyniak, Jacques Bernier, Michel Fournier, and Denis Flipo
- Subjects
Lipopolysaccharide ,biology ,Health, Toxicology and Mutagenesis ,Antibody titer ,General Medicine ,biology.organism_classification ,Median lethal dose ,chemistry.chemical_compound ,Titer ,Mouse hepatitis virus ,Immune system ,chemistry ,Antigen ,Immunology ,Cytotoxic T cell ,Agronomy and Crop Science - Abstract
Effect of selected organochlorine, organophosphorus, and carbamate pesticides on the humoral immune IgM response was examined upon immunization of inbred C57B1/6 mice with neutral, polyvalent, T-dependent sheep erythrocytes (SRBC) and T-independent lipopolysaccharide (LPS). In addition, a pathogenic antigen, mouse hepatitis virus 3 (MHV3) was used for determination for the interaction of selected pesticides on the primary IgG immune response in a model of viral infection, of the genetically resistant A/J mouse strain. Single, sublethal doses of dieldrin, carbofuran, and matacil induced a marked immunosuppression of the humoral responses to both neutral and pathogenic antigens. The data showed that single, sublethal doses (0.4 ≤ LD 50 ≤ 0.6) of dieldrin, carbofuran, and matacil inhibited the number of SRBC-primed cells without any direct cytotoxic effect on the activated plasmocyte, as the titer of specific antibody measured by an enzyme-linked immunosorbent assay (ELISA) per activated cell, was constant. In contrast, exposure to malathion at 10–14 days prior to the assay increased the number of plaque-forming cells (PFC) and the anti-SRBC IgM and anti-MHV3 IgG antibody titer, suggesting therefore an increase in the humoral response to neutral and pathogenic antigens in C57B1/6 and A/J mice. Immunomodulation of the humoral IgM response by selected pesticides was shown to take place at a stage prior to antibody secretion from the activated cell, as the ELISA/PFC index was similar to the control value. The data obtained for dieldrin-induced inhibition of the humoral response to SRBC and LPS antigens suggest a mechanism of immunosuppression common for both T-dependent and T-independent antigens. Good correlations were obtained for the immunomodulatory effects of selected pesticides, as measured by PFC and ELISA, which encourages support for the latter technique in the immunotoxicological screening of pesticides.
- Published
- 1986
- Full Text
- View/download PDF
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