The Experts below are selected from a list of 7632 Experts worldwide ranked by ideXlab platform
Romain Duval - One of the best experts on this subject based on the ideXlab platform.
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Ultraspecific live imaging of the dynamics of zebrafish neutrophil granules by a histopermeable fluorogenic benzochalcone probe
Chemical Science, 2019Co-Authors: Emma Colucci-guyon, Ariane Batista, Suellen Oliveira, Magali Blaud, Ismael Bellettini, Benoit Marteyn, Karine Leblanc, Philippe Herbomel, Romain DuvalAbstract:Neutrophil granules (NGs) are key components of the innate immune response and mark the development of the hematopoietic system in mammals. However, no specific fluorescent Vital Stain existed up to now to monitor their dynamics within a whole live organism. We rationally designed a benzochalcone fluorescent probe (HAB) featuring high tissue permeability and optimal photophysics such as elevated quantum yield, pronounced solvatochromism and target-induced fluorogenesis. Phenotypic screening identified HAB as the first cell-and organelle-specific small-molecule tracer of NGs in live zebrafish larvae, with no labeling of any other cell types or organelles. HAB Staining was independent of the state of neutrophil activation, labeling NGs of both resting and phagocytically-active cells with equal specificity. By high-resolution live imaging, we documented the dynamics of HAB-Stained NGs during phagocytosis. Upon zymosan injection, labeled NGs were rapidly recruited to the forming phagosome in live zebrafish phagocytosing neutrophils. Despite being a reversible ligand, HAB could not be displaced by high concentrations of pharmacologically-relevant competing chalcones, indicating that this specific labeling was the result of HAB precise physicochemical signature rather than a general feature of chalcones. However, one of the competitors was discovered as a promising interstitial fluorescent tracer illuminating zebrafish histology, similarly to BODIPY-ceramide. As a yellow-emitting histopermeable Vital Stain, HAB functionally and spectrally complements most genetically-incorporated fluorescent tags commonly used in live zebrafish biology, holding promise for the study of neutrophil-dependent responses relevant to human physiopathology such as developmental defects, inflammation and infection. Furthermore, HAB intensely labeled isolated live human neutrophils at the level of granulated subcellular structures consistent with human NGs, suggesting that the labeling of NGs by HAB is not restricted to the zebrafish model but also relevant to mammalian systems.
Emma Colucci-guyon - One of the best experts on this subject based on the ideXlab platform.
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Ultraspecific live imaging of the dynamics of zebrafish neutrophil granules by a histopermeable fluorogenic benzochalcone probe
Chemical Science, 2019Co-Authors: Emma Colucci-guyon, Ariane Batista, Suellen Oliveira, Magali Blaud, Ismael Bellettini, Benoit Marteyn, Karine Leblanc, Philippe Herbomel, Romain DuvalAbstract:Neutrophil granules (NGs) are key components of the innate immune response and mark the development of the hematopoietic system in mammals. However, no specific fluorescent Vital Stain existed up to now to monitor their dynamics within a whole live organism. We rationally designed a benzochalcone fluorescent probe (HAB) featuring high tissue permeability and optimal photophysics such as elevated quantum yield, pronounced solvatochromism and target-induced fluorogenesis. Phenotypic screening identified HAB as the first cell-and organelle-specific small-molecule tracer of NGs in live zebrafish larvae, with no labeling of any other cell types or organelles. HAB Staining was independent of the state of neutrophil activation, labeling NGs of both resting and phagocytically-active cells with equal specificity. By high-resolution live imaging, we documented the dynamics of HAB-Stained NGs during phagocytosis. Upon zymosan injection, labeled NGs were rapidly recruited to the forming phagosome in live zebrafish phagocytosing neutrophils. Despite being a reversible ligand, HAB could not be displaced by high concentrations of pharmacologically-relevant competing chalcones, indicating that this specific labeling was the result of HAB precise physicochemical signature rather than a general feature of chalcones. However, one of the competitors was discovered as a promising interstitial fluorescent tracer illuminating zebrafish histology, similarly to BODIPY-ceramide. As a yellow-emitting histopermeable Vital Stain, HAB functionally and spectrally complements most genetically-incorporated fluorescent tags commonly used in live zebrafish biology, holding promise for the study of neutrophil-dependent responses relevant to human physiopathology such as developmental defects, inflammation and infection. Furthermore, HAB intensely labeled isolated live human neutrophils at the level of granulated subcellular structures consistent with human NGs, suggesting that the labeling of NGs by HAB is not restricted to the zebrafish model but also relevant to mammalian systems.
M B Finnegan - One of the best experts on this subject based on the ideXlab platform.
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determination of the in situ bactericidal activity of an essential oil mouthrinse using a Vital Stain method
Journal of Clinical Periodontology, 2000Co-Authors: P Pan, M L Barnett, J Coelho, C Brogdon, M B FinneganAbstract:Background: Recent research has indicated that bacteria within a biofilm may undergo changes in susceptibility to antimicrobial agents when compared to planktonic forms. This study was conducted to determine the bactericidal effect of an essential oil-containing mouthrinse (Listerine® Antiseptic) on dental plaque bacteria in situ. Methods: 1-day-old plaque in 17 subjects was sampled at baseline from the buccal surfaces of diagonally contralateral maxillary and mandibular bicuspids and 1st molars. Subjects were then randomly assigned either an essential oil mouthrinse or a sterile saline negative control and rinsed under supervision with 20 ml for 30 s. 30 min later, plaque was sampled from the remaining contralateral posterior teeth. Subjects repeated these procedures with their respective alternate rinse after 1 week. Pooled plaque samples from each subject at each sampling period were Stained with a commercially-available fluorescent Stain which fluoresces live and dead bacteria green and red, respectively. The Stained plaque specimens were analyzed using computerized image analysis. A separate in vitro study was conducted to determine the relationship between the % red Stain per sample and bacterial viability. Results: Analysis of Vital Stained plaque specimens indicated that following rinsing with the essential oil mouthrinse, 78.7% of bacteria were dead compared to 27.9% following rinsing with the negative control (p<0.001). The in vitro findings demonstrated that the % red Stain per sample is reflective of actual bacterial kill. Conclusions: This study confirms the findings of previous in vitro and in vivo studies which demonstrated the essential oil mouthrinse to have significant biocidal activity against oral micro-organisms. These studies all support the primacy of a bactericidal mechanism in producing the plaque and gingivitis reductions observed in numerous clinical trials conducted on the essential oil mouthrinse.
Andrew W Claridge - One of the best experts on this subject based on the ideXlab platform.
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mycorrhizal effectiveness of rhizopogon spores recovered from faecal pellets of small forest dwelling mammals
Fungal Biology, 2002Co-Authors: Wes Colgan, Andrew W ClaridgeAbstract:Mature basidiomes of the hypogeous ectomycorrhizal fungi Rhizopogon vinicolor and R. truncatus were fed to three species of mycophagous mammals in captivity. Spores which passed through the digestive tract of the mammals were isolated from faecal pellets. The metabolic activity and mycorrhizal effectiveness of these spores was assessed. Flouricene-diacetate (a Vital Stain) was used to assess spore metabolic activity. Mycorrhizal effectiveness was determined by inoculating Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) seedlings with spore slurries. The same assays were performed on spores isolated from uneaten basidiomes. Spores from R. vinicolor were viable after passage through the gut of each mammal species but the digestive process did not substantially enhance or detract from the ability of spores to form ectomycorrhizas relative to spores from uneaten basidiomes. Spores recovered from faeces of Californian red-backed vole (Clethrionomys californicus) and Townsend's chipmunk (Tamias townsendii) had significantly higher metabolic activity than spores from uneaten basidiomes and those recovered from northern flying squirrel (Glaucomys sabrinus) faeces. Spores from eaten and uneaten basidiomes of R. truncatus failed to show any signs of metabolic activity and largely failed to form ectomycorrhizas on seedlings. The reasons for this are unclear but we suggest that germination of spores from this fungus may depend upon other factors. Our findings add to the growing body of literature demonstrating that spores of at least some species of hypogeous fungi remain viable after passage through the digestive tract of mycophagous animals.
Philippe Herbomel - One of the best experts on this subject based on the ideXlab platform.
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Ultraspecific live imaging of the dynamics of zebrafish neutrophil granules by a histopermeable fluorogenic benzochalcone probe
Chemical Science, 2019Co-Authors: Emma Colucci-guyon, Ariane Batista, Suellen Oliveira, Magali Blaud, Ismael Bellettini, Benoit Marteyn, Karine Leblanc, Philippe Herbomel, Romain DuvalAbstract:Neutrophil granules (NGs) are key components of the innate immune response and mark the development of the hematopoietic system in mammals. However, no specific fluorescent Vital Stain existed up to now to monitor their dynamics within a whole live organism. We rationally designed a benzochalcone fluorescent probe (HAB) featuring high tissue permeability and optimal photophysics such as elevated quantum yield, pronounced solvatochromism and target-induced fluorogenesis. Phenotypic screening identified HAB as the first cell-and organelle-specific small-molecule tracer of NGs in live zebrafish larvae, with no labeling of any other cell types or organelles. HAB Staining was independent of the state of neutrophil activation, labeling NGs of both resting and phagocytically-active cells with equal specificity. By high-resolution live imaging, we documented the dynamics of HAB-Stained NGs during phagocytosis. Upon zymosan injection, labeled NGs were rapidly recruited to the forming phagosome in live zebrafish phagocytosing neutrophils. Despite being a reversible ligand, HAB could not be displaced by high concentrations of pharmacologically-relevant competing chalcones, indicating that this specific labeling was the result of HAB precise physicochemical signature rather than a general feature of chalcones. However, one of the competitors was discovered as a promising interstitial fluorescent tracer illuminating zebrafish histology, similarly to BODIPY-ceramide. As a yellow-emitting histopermeable Vital Stain, HAB functionally and spectrally complements most genetically-incorporated fluorescent tags commonly used in live zebrafish biology, holding promise for the study of neutrophil-dependent responses relevant to human physiopathology such as developmental defects, inflammation and infection. Furthermore, HAB intensely labeled isolated live human neutrophils at the level of granulated subcellular structures consistent with human NGs, suggesting that the labeling of NGs by HAB is not restricted to the zebrafish model but also relevant to mammalian systems.
