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Fluorescence Microscopy Image (fluorescence + microscopy_image)
Selected AbstractsStudy of the MR relaxation of microglia cells labeled with Gd-DTPA-bearing nanoparticlesCONTRAST MEDIA & MOLECULAR IMAGING, Issue 3 2009Emeline Julie Ribot Abstract Therapies involving cells as vehicles need to visualize in situ the trafficking of the cells concerned. This cellular imaging can be driven by cell contrast agent-based nanoparticle internalization and non-invasive MRI (magnetic resonance imaging) detection. Here, microglial cells, that would transport a suicide gene to a glioma, were incubated for different times, with various concentrations of silica nanoparticles on which numerous Gd-DTPA were grafted. The goal of this study was to investigate the repartition of cell-associated particles. MRI was used to quantitatively follow the particle uptake process. Fluorescence microscopy images showed that, although most of the nanoparticles were internalized, some remained adsorbed on the extracellular membrane surface. The cells were then submitted to various treatments: glycine to release bound nanoparticles and/or ultrasound to destroy the cell membranes. The R1 relaxation rates were measured at 4.7 T. R1 was maximal for 4,h of incubation, decreased after 8,h and remained stable for the 24 following hours. The magnetic resonance signal of ultrasonicated and glycine-treated cells made it possible to quantify the loss of bound nanoparticles after 8,h. Nevertheless, this release did not prevent cell detection since the internalized nanoparticles are enough concentrated to visualize the labeled cells even after 4 days of cell growth. These results highlight the compartmentalization of nanoparticles in microglia and the evolution of the MR signal of the labeled cells. This study could be of importance to interpret in vivo the MR signal changes that could occur after administration of such nanoparticle-labeled cells in therapeutic strategies. Copyright © 2009 John Wiley & Sons, Ltd. [source] Cover Picture , Eur.EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2006The cover has been specifically designed to introduce the 16th European Congress of Immunology. It combines a picture of the Eiffel Tower with a fluorescence microscopy image of immune cells, underlining the immunological research that will be discussed at the meeting. The immunofluorescence staining shows B lymphocytes (CD45 in red, IgM in blue) forming an immunological synapse with an antigen presenting cell (ICAM-1 in green) and was kindly provided by Yolanda Carrasco, Cancer Research UK, London. [source] Supramolecular Assembly of Perylene Bisimide with , -Cyclodextrin Grafts as a Solid-State Fluorescence Sensor for Vapor DetectionADVANCED FUNCTIONAL MATERIALS, Issue 14 2009Yu Liu Abstract A nanoscopic supramolecular aggregate is constructed from perylene bisimide-bridged bis-(permethyl- , -cyclodextrins) 1 via ,,, stacking interactions. Its self-assembly behavior in organic and aqueous solutions is investigated by UV,Vis, fluorescence, and 1H NMR spectroscopy. Transmission electron microscopy and scanning electron microscopy images show the 1D nanorod aggregation of 1, which is birefringent under crossed polarizer conditions and strongly fluorescent as depicted in the fluorescence microscopy image. X-ray powder diffraction measurements indicate that 1 forms a well-ordered crystalline arrangement with a ,,, stacking distance of 4.02,Ĺ. Furthermore, the solid-state fluorescence sensing is explored by utilizing the poly(vinylidene fluoride) membrane-embedded 1, giving that 1, as a novel vapor detecting material, can probe several kinds of volatile organic compounds and, especially, exhibits high sensitivity to organic amines. [source] Confined displacement algorithm determines true and random colocalization in fluorescence microscopyJOURNAL OF MICROSCOPY, Issue 3 2010O. RAMÍREZ Summary The quantification of colocalizing signals in multichannel fluorescence microscopy images depends on the reliable segmentation of corresponding regions of interest, on the selection of appropriate colocalization coefficients, and on a robust statistical criterion to discriminate true from random colocalization. Here, we introduce a confined displacement algorithm based on image correlation spectroscopy in combination with Manders colocalization coefficients M1ROI and M2ROI to quantify true and random colocalization of a given florescence pattern. We show that existing algorithms based on block scrambling exaggerate the randomization of fluorescent patterns with resulting inappropriately narrow probability density functions and false significance of true colocalization in terms of p values. We further confine our approach to subcellular compartments and show that true and random colocalization can be analysed for model dendrites and for GABAB receptor subunits GABABR1/2 in cultured hippocampal neurons. Together, we demonstrate that the confined displacement algorithm detects true colocalization of specific fluorescence patterns down to subcellular levels. [source] Red Blood Cell Templated Polyelectrolyte Capsules: A Novel Vehicle for the Stable Encapsulation of DNA and ProteinsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 6 2006Oliver Kreft Abstract Summary: A novel method for the encapsulation of biomacromolecules, such as nucleic acids and proteins, into polyelectrolyte microcapsules is described. Fluorescence-labelled double-stranded DNA and human serum albumin (HSA) are used as model substances for encapsulation in hollow microcapsules templated on human erythrocytes. The encapsulation procedure involves an intermediate drying step. The accumulation of DNA and HSA in the capsules is observed by confocal laser scanning microscopy, UV spectroscopy, and fluorimetry. The mechanism of encapsulation is discussed. Confocal fluorescence microscopy images of encapsulated TRITC-HSA (left) and dsDNA (right). Inserts demonstrate fluorescence profiles for both compounds. [source] | |||||||||||||