Search results for "Dye"
showing 10 items of 577 documents
A fast kinetic method for assessing mitochondrial membrane potential in isolated hepatocytes with rhodamine 123 and flow cytometry
1994
Rhodamine 123 (Rh123) is widely used as a flow cytometric probe for mitochondrial membrane potential (MMP) in metabolic, pharmacologic, and toxicological studies. However, the use of relatively high concentrations of Rh123 (up to 10 micrograms/ml) and prolonged incubation times (up to 1 h), including washing steps, may be inconvenient for certain applications in which labile cells are used or which demand rapid or repeated analysis. In this paper we describe a rapid kinetic assay of MMP in isolated rat hepatocytes, based upon the quantitation of the initial rate of Rh123 uptake by living cells, selected by their scattering properties. The results indicate that at an appropriate dye-to-cell …
Impact of 7-Ketocholesterol and Very Long Chain Fatty Acids on Oligodendrocyte Lipid Membrane Organization: Evaluation Via LAURDAN and FAMIS Spectral…
2011
International audience; In the context of multiple sclerosis and X-linked adrenoleukodystrophy, 7-ketocholesterol (7KC) and very long chain fatty acids (C24:0, C26:0) are supposed to induce side effects respectively on oligodendrocytes which are myelin (which is a lipoproteic complex) synthesizing cells. The effects of 7KC (25, 50 mu M), C24:0 and C26:0 (10, 20 mu M) on cell viability and lipid membrane organization were investigated on 158N murine oligodendrocytes. Concerning 7KC and fatty acids (at 20 mu M only):1) cell growth was strongly inhibited; 2) marked induction of cell death was revealed with propidium iodide (PI); 3) no apoptotic cells were found with C24:0 and C26:0 (absence of…
Dynamic in vivo Imaging of Microvasculature and Perfusion by Miniaturized Confocal Laser Microscopy
2008
<i>Introduction:</i> Microvasculature and associated pathologies mandate dynamic imaging. We evaluated a novel miniaturized confocal laser scanning probe for in vivo visualization of blood vessels, blood flow, cell tracking and perfusion in both healthy rodents and disease models.<i> Methods:</i> The hand-held confocal microscopy system allowed a 500- to 2,400-fold magnification at a dynamically variable imaging depth. Different intravital stains were used alone or in combination for tissue, nuclear, plasma and vascular endothelial cell staining and for blood flow visualization, and targeted staining for individual cell populations. <i>Results:</i> Precis…
Ultrastructural alterations and environmental exposure influence the opiate concentrations in hair of drug addicts
1995
Hair samples were taken at autopsy from the head of 1 male and 1 female subject both known as drug abusers. Some of the strands were bleached by in-vitro cosmetic treatment. The bleached hair as well as the original hair samples were partly exposed to water or soil prior to further investigations and drug monitoring. The exposure times were 4 weeks or 6 months for water and 6 months for soil. The hair fibers were examined by transmission electron microscope (TEM) and by scanning electron microscope (SEM) investigations. The electron microscope studies confirmed that all experimental conditions had produced morphological alterations in the hair fibers. After exposure to water or to soil for …
Analysis of the membrane potential of rat- and mouse-liver mitochondria by flow cytometry and possible applications.
1990
Washed and purified rat- or mouse-liver mitochondria exhibiting high membrane integrity and metabolic activity were studied by flow cytometry. The electrophoretic accumulation/redistribution of cationic lipophilic probes, rhodamine 123, safranine O and a cyanine derivative, 3,3'-dihexyloxadicarbocyanine iodide, during the energization process was studied and was consistent with the generation of a negative internal membrane potential. An exception to this was nonylacridine orange which spontaneously bound to the mitochondrial membrane by hydrophobic interactions via its hydrocarbon chain. Energized purified mitochondria stained with potentiometric dyes exhibited both higher fluorescence and…
Local barrier dysfunction identified by confocal laser endomicroscopy predicts relapse in inflammatory bowel disease
2011
Objectives: Loss of intestinal barrier function plays an important role in the pathogenesis of inflammatory bowel disease (IBD). Shedding of intestinal epithelial cells is a potential cause of barrier loss during inflammation. The objectives of the study were (1) to determine whether cell shedding and barrier loss in humans can be detected by confocal endomicroscopy and (2) whether these parameters predict relapse of IBD. Methods: Confocal endomicroscopy was performed in IBD and control patients using intravenous fluorescein to determine the relationship between cell shedding and local barrier dysfunction. A grading system based on appearances at confocal endomicroscopy in humans was devise…
In-vivo confocal real-time mini-microscopy in animal models of human inflammatory and neoplastic diseases
2007
Background and study aims Although various improvements in tissue imaging modalities have recently been achieved, in-vivo molecular and subsurface imaging in the field of gastroenterology remains a technical challenge. In this study we evaluated a newly developed, handheld, miniaturized confocal laser microscopy probe for real-time in-vivo molecular and subsurface imaging in rodent models of human disease. Materials and methods The minimicroscope uses a 488-nm, single line laser for fluorophore excitation. The optical slice thickness is 7 microm, the lateral resolution 0.7 microm. The range of the z-axis is 0-250 microm below the tissue surface. Imaging was performed using different fluores…
In vivo subsurface morphological and functional cellular and subcellular imaging of the gastrointestinal tract with confocal mini-microscopy.
2007
AIM: To evaluate a newly developed hand-held confocal probe for in vivo microscopic imaging of the complete gastrointestinal tract in rodents. METHODS: A novel rigid confocal probe (diameter 7 mm) was designed with optical features similar to the flexible endomicroscopy system for use in humans using a 488 nm single line laser for fluorophore excitation. Light emission was detected at 505 to 750 nm. The field of view was 475 μm × 475 μm. Optical slice thickness was 7 μm with a lateral resolution of 0.7 μm. Subsurface serial images at different depths (surface to 250 μm) were generated in real time at 1024 × 1024 pixels (0.8 frames/s) by placing the probe onto the tissue in gentle, stable co…
Sub-cellular tumor identification and markerless differentiation in the rat brain in vivo by multiphoton microscopy
2012
Objective/Background Aim of the current study was to localize and differentiate between tumor (glioma) and healthy tissue in rat brains on a cellular level. Near-infrared multiphoton microscopy takes advantage of the simultaneous absorption of two or more photons to analyze various materials such as cell and tissue components via the observation of endogenous fluorophores such as NAD(P)H, FAD, porphyrins, melanin, elastin, and collagen, with a very high resolution, without inducing the problems of photo-bleaching on out-of-focus areas. Methods In vitro and in vivo studies on healthy rat brains as well as C6 glioma cell line allografts have been performed. Near-infrared laser pulses (λ = 690…
Comparison of different quantification methods to determine hippocampal damage after cerebral ischemia
2014
Abstract Background Experimental stroke studies use multiple techniques to evaluate histopathological damage. Unfortunately, sensitivity and reproducibility of these techniques are poorly characterized despite pivotal influence on results. Method The present study compared several quantification methods to differentiate between two severities of global cerebral ischemia and reperfusion. Male Sprague-Dawley rats were randomized to moderate (10 min) or severe (14 min) ischemia by bilateral carotid occlusion (BCAO) with hemorrhagic hypotension. Neuronal cell count was determined in hippocampus at bregma −3.14 mm and −3.8 mm on day 3 and 28 post insult by counting neurons in the whole CA1 or in…