Search results for " Microscopy"
showing 10 items of 1617 documents
Gold( i )–BODIPY–imidazole bimetallic complexes as new potential anti-inflammatory and anticancer trackable agents
2017
International audience; Two new gold(I)–BODIPY–imidazole based trackable therapeutic bimetallic complexes have been synthesized and fully characterized. They display strong antiproliferative properties on several types of cancers including colon, breast, and prostate and one of them presents a significant anti-inflammatory effect. Additionally, the two compounds could be visualised in vitro by confocal microscopy in the submicromolar range.
Determination of particle number and brightness using a laser scanning confocal microscope operating in the analog mode
2008
We describe a method to obtain the brightness and number of molecules at each pixel of an image stack obtained with a laser scanning microscope. The method is based on intensity fluctuations due to the diffusion of molecules in a pixel. For a detector operating in the analog mode, the variance must be proportional to the intensity. Once this constant has been calibrated, we use the ratio between the variance and the intensity to derive the particle brightness. Then, from the ratio of the intensity to the brightness we obtain the average number of particles in the pixel. We show that the method works with molecules in solution and that the results are comparable to those obtained with fluctu…
Chemical Identification at the Solid–Liquid Interface
2017
Solid-liquid interfaces are decisive for a wide range of natural and technological processes, including fields as diverse as geochemistry and environmental science as well as catalysis and corrosion protection. Dynamic atomic force microscopy nowadays provides unparalleled structural insights into solid-liquid interfaces, including the solvation structure above the surface. In contrast, chemical identification of individual interfacial atoms still remains a considerable challenge. So far, an identification of chemically alike atoms in a surface alloy has only been demonstrated under well-controlled ultrahigh vacuum conditions. In liquids, the recent advent of three-dimensional force mapping…
Cannabinoid control of brain bioenergetics: Exploring the subcellular localization of the CB1 receptor
2014
Brain mitochondrial activity is centrally involved in the central control of energy balance. When studying mitochondrial functions in the brain, however, discrepant results might be obtained, depending on the experimental approaches. For instance, immunostaining experiments and biochemical isolation of organelles expose investigators to risks of false positive and/or false negative results. As an example, the functional presence of cannabinoid type 1 (CB1) receptors on brain mitochondrial membranes (mtCB1) was recently reported and rapidly challenged, claiming that the original observation was likely due to artifact results. Here, we addressed this issue by directly comparing the procedures…
Flow cytometry and spectral imaging multiphoton microscopy analysis of CD36 expression with quantum dots 605 of untreated and 7-ketocholesterol-treat…
2006
To evaluate CD36 expression with quantum dots 605 (QDs 605) on untreated and 7-ketocholesterol (7KC)-treated monocytic U937 cells by flow cytometry (FCM) and confocal and multiphoton laser scanning microscopy (CLSM).Cells were analyzed by CLSM, following flow cytometric quantification of CD36 expression and 7KC uptake. Image sequences were obtained by spectral analysis in monophoton and multiphoton CLSM and analyzed by the factor analysis of medical image sequences (FAMIS) algorithm to differentiate emission spectra. In CLSM analysis, cell deposits were screened in ultraviolet excitation modes to optimize the possibilities of QDs 605 and have the benefit of nuclei counterstaining by DAPI.FC…
Cross-recognition of a myelin peptide by CD8+ T cells in the CNS is not sufficient to promote neuronal damage.
2015
Multiple sclerosis (MS) is an inflammatory disease of the CNS thought to be driven by CNS-specific T lymphocytes. Although CD8+T cells are frequently found in multiple sclerosis lesions, their distinct role remains controversial because direct signs of cytotoxicity have not been confirmedin vivo. In the present work, we determined that murine ovalbumin-transgenic (OT-1) CD8+T cells recognize the myelin peptide myelin oligodendrocyte glycoprotein 40–54 (MOG40–54) bothin vitroandin vivo. The aim of this study was to investigate whether such cross-recognizing CD8+T cells are capable of inducing CNS damagein vivo. Using intravital two-photon microscopy in the mouse model of multiple sclerosis, …
HSP90 AND ENOS PARTIALLY CO-LOCALIZE AND CHANGE CELLULAR LOCALIZATION IN RELATION TO DIFFERENT ECM COMPONENTS IN 2D AND 3D CULTURES OF ADULT RAT CARD…
2007
BACKGROUND INFORMATION: Cultivation techniques promoting three-dimensional organization of mammalian cells are of increasing interest, since they confer key functionalities of the native ECM (extracellular matrix) with a power for regenerative medicine applications. Since ECM compliance influences a number of cell functions, Matrigel-based gels have become attractive tools, because of the ease with which their mechanical properties can be controlled. In the present study, we took advantage of the chemical and mechanical tunability of commonly used cell culture substrates, and co-cultures to evaluate, on both two- and three-dimensional cultivated adult rat cardiomyocytes, the impact of ECM c…
Immunogold Labeling to Detect Streptococcus pyogenes Cas9 in Cell Culture and Tissues by Electron Microscopy
2019
Final publication is available from Mary Ann Liebert, Inc., publishers https://doi.org/10.1089/crispr.2019.0032. The CRISPR-Cas9 system is a powerful and yet precise DNA-editing tool in rapid development. By combining immunogold labeling and electron microscopy with the novel CRISPR-Cas9 system, we propose a new method to gain insight into the biology of this tool. In this study, we analyzed different Cas9-induced systems such as HEK293T cell line, murine oligodendrocyte progenitor cells, brain and liver to detect Cas9 expression by immunoelectron microscopy. Our results show that while Cas9 expression could be found in the nuclei and nucleopores of transfected HEK293T cells, in transfected…
Where Is the Most Hydrophobic Region? Benzopurpurine Self-Assembly at the Calcite–Water Interface
2017
Control of molecular self-assembly at solid–liquid interfaces is challenging due to the complex interplay between molecule–molecule, molecule–surface, molecule–solvent, surface–solvent, and solvent–solvent interactions. Here, we use in-situ dynamic atomic force microscopy to study the self-assembly of Benzopurpurine 4B into oblong islands with a highly ordered inner structure yet incommensurate with the underlying calcite (10.4) surface. Molecular dynamics and free energy calculations provide insights by showing that Benzopurpurine 4B molecules do not anchor to the surface directly but instead assemble on top of the second hydration layer. This seemingly peculiar behavior was then rationali…
Stabilization of Polar Step Edges on Calcite (10.4) by the Adsorption of Congo Red
2015
In this work, we present the stabilization of polar step edges along the [010] direction of calcite (10.4) by the presence of a water-soluble organic molecule, namely Congo Red. While characteristic etch pits are observed on the surface in the absence of the additive, no etch pits can be found in the presence of the additive. Using atomic force microscopy, we can directly follow the restructuring of the surface. Upon addition of Congo Red, the charge-neutral step edges confining the characteristic etch pits vanish, while polar step edges along the [010] direction appear on the surface, which are entirely decorated by well-ordered molecular islands of the additive. After the restructuring ha…