Search results for "Microscopy"
showing 10 items of 3390 documents
Giant axonal neuropathy and leukodystrophy
1991
Abstract An 11-year-old Persian boy, born to consanguineous parents, manifested a progressive gait abnormality beginning at 5 years of age. A severe cerebellar disorder developed with associated dysfunction of the peripheral nervous system, but no sign of mental impairment. The sensory and motor nerve conduction velocities were greatly reduced, especially in the lower extremities. Cerebrospinal fluid protein was normal. Computed tomography and magnetic resonance imaging revealed leukoencephalopathy, especially in the cerebellum, but also in periventricular areas. The diagnosis of giant axonal neuropathy was established by biopsy of the sural nerve. The few previous histologic examinations h…
Mediator-Induced Changes in Macromolecular Permeability in the Rat Mesenteric Microcirculation
1995
An intravital fluorescence microscopic method for measurement of changes in macromolecular permeability has been established in the mesenterial microcirculation of the rat. After exteriorization of the fat-free distal part of the ileal mesentery, a 1-hr period of stabilization was followed by the injection of FITC-labeled macromolecules. Five minutes later, histamine, leukotriene B4, or leukotriene C4 was topically applied to the tissue by means of a micromanipulator. Areas of 1 mm2 were videotaped with a SIT camera. The fluorescence intensity of these areas was measured by an analogous video image processing system and displayed as gray value histograms. The shift of the frequency of gray …
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…
Evaluation of the tissue reaction to a new bilayered collagen matrix in vivo and its translation to the clinic.
2011
This study evaluates a new collagen matrix that is designed with a bilayered structure in order to promote guided tissue regeneration and integration within the host tissue. This material induced a mild tissue reaction when assessed in a murine model and was well integrated within the host tissue, persisting in the implantation bed throughout the in vivo study. A more porous layer was rapidly infiltrated by host mesenchymal cells, while a layer designed to be a barrier allowed cell attachment and host tissue integration, but at the same time remained impermeable to invading cells for the first 30 days of the study. The tissue reaction was favorable, and unlike a typical foreign body respons…
Adhesive interaction measured between AFM probe and lung epithelial type II cells
2007
The toxicity of inhaled nanoparticles entering the body through the lung is thought to be initially defined by the electrostatic and adhesive interaction of the particles with lung's wall. Here, we investigated the first step of the interaction of nanoparticles with lung epithelial cells using atomic force microscope (AFM) as a force apparatus. Nanoparticles were modeled by the apex of the AFM tip and the forces of interaction between the tip and the cell analyzed over time. The adhesive force and work of adhesion strongly increased for the first 100 s of contact and then leveled out. During this time, the tip was penetrating deeply into the cell. It first crossed a stiff region of the cell…
Bizarre alterations of the morphology of pineal synaptic bodies under constant light and an evaluation of suitable 3D-reconstruction software
2004
Three dimensional (3D) reconstruction and modelling software was evaluated to find a procedure suitable for visualization of small subcellular structures in transmission electron microscope images. The method applied in this study demonstrates bizarre alterations of the structure of synaptic bodies (SBs) in pinealocytes of the guinea-pig pineal gland caused by constant illumination. It can, in general, be used for any 3D reconstruction from serial sections. Pineal glands of five guinea-pigs (two kept under a LD cycle of 12:12 h; three kept in constant light, for 4 months) were investigated. SBs consist of an electron-dense centre with attached vesicles. Under normal lighting conditions most…
Short-term response of three resin-based materials as desensitizing agents under oral environmental exposure
2012
Objective. This paper focuses on clinical responses after 7 days of oral exposure to two resin-based materials as desensitizing agents compared to a fluoride varnish and on morphological and analytical study as a means to elucidate the mechanism of action. Materials and methods. The elemental composition of Vertise™ Flow (VF), Universal Dentine Sealant (UDS) and Flor-Opal® Varnish (FOV) were investigated by using an X-ray energy dispersive spectrometer (EDX) in conjunction with a scanning electron microscope (SEM). SEM morphology of the material-treated dentine surfaces and pain reduction ability according to the Visual Analogue Scale (VAS) were evaluated in selected hypersensitive teeth. P…
Analysis of the tegument of Zygocotyle lunata (Trematoda: Paramphistomidae) adults by scanning electron microscopy.
2012
Paramphistomiasis is a parasitic disease caused by various species of the Paramphistomidae. These species mainly affect domestic and wild ruminants; the economic impact of these diseases is often underestimated. Traditionally, the identification of paramphistomes has been difficult and has been based on morphological aspects such as the body shape, the position of the esophagus and cecae, or the tegumental papillae. Despite the many investigations regarding the tegumental papillae for other paramphistomes, very few efforts have been made using Zygocotyle lunata, partly because many authors differ with respect to the importance of papillae in the classification of paramphistomids. Herein, we…
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…
Toxicity of 5- chloro- 3- methyl- catechol to rat: Chemical observations and light microscopy of the tissue
1979
5-chloro-3-methyl-catechol was first time described by GAUNT and EVANS (1961) as a metabolite of MCPA (4-chloro-2-methylphenoxyacetic aci~which is the most widely used herbicide in the Nordic countries. The toxicity of the metabolite 5-chloro-3-methylcatechol bas hot been studied so far. Other catechols like 3,5dichlorocatechol has been shown to be a metabollte of 2,4-D (BOLLAG et ai. 1968a, BOLLAG et ai. 1968b), and it has been proven to be toxic to cells by HORVATH (1971). The catechols are metabolized by bacteria finally to muconic semialdehyde (HORVATH 1970, HORVATH and ALEXANDER 1970). In this work the toxicity of 5-chloro-3-methyl-catechol to maie rats was studied in acute and subchro…