Search results for "confocal microscopy"

Simultaneous confocal laser endomicroscopy and chromoendoscopy with topical cresyl violet

2009

Background Confocal laser endomicroscopy (CLE) has been shown to reliably predict histology during ongoing endoscopy. To unmask lesions for CLE, chromoendoscopy has been mandated. Usually fluorescein then serves as a contrast agent for CLE, but it does not allow direct nuclear visualization, must be injected, leads to a transient skin discoloration, and may have allergic side effects. Objective To establish a single topical dye, cresyl violet (CV), for simultaneous chromoendoscopy and in vivo CLE of the lower GI tract. Design Animal preclinical study, prospective clinical trial. Setting Mainz University Clinic (tertiary care center). Patients, Methods, and Interventions To establish the sta…

Reflectance mode confocal microscopy and digital image analysis in naevus of Hori and pathogenetic evaluation

2012

Use of flow cytometry and confocal microscopy techniques to investigate early CdCl(2)-induced nephrotoxicity in vitro.

2001

CdCl(2) is a well-known toxic compound for the kidney in vivo and in vitro. We report here part of the results of an ECVAM (European Centre for the Validation of Alternative Methods) contract study, aimed at establishing and assessing several flow cytometric and confocal microscopic endpoints for use in an in vitro nephrotoxicity model. Three renal tubule cell lines, OK (opossum, proximal tubule origin), LLC-PK1 (pig, proximal tubule origin) and MDCK (dog, distal tubule origin) were exposed for 1, 5 and 24 h to 25 microM and 100 microM CdCl(2). The results obtained for mitochondrial membrane potential showed a decrease in all the cell lines after 5 h of treatment with both CdCl(2) concentra…

Efficient Cementing of CH3NH3PbBr3Nanoparticles to Upconversion Nanoparticles Visualized by Confocal Microscopy

2016

Upconversion-perovskite nanohybrids are prepared by assembling CH3NH3PbBr3 perovskite nanoparticles (PK) with naked NaYF4:Yb3+,Tm3+ nanoparticles (UCn) via an innovative strategy consisting of using cucurbit[7]uril (CB[7]) to anchor the perovskite nanoparticles firmly and closely to the upconversion nanoparticles, thus leading to UCn@PKCB nanohybrids. A commercial multiphoton laser scanning confocal microscope is used to demonstrate the successful assembly. This technique proves to be useful to evaluate luminescence lifetime in the range of several tens of μs and allows visualization of the extraordinarily efficient nontrivial resonance energy transfer from the upconversion nanoparticle to …

Reduction of focus size in tightly focused linearly polarized beams

2004

The electromagnetic theory predicts that when a linearly polarized collimated field is focused by a high-angle focusing system, components perpendicular to the initial polarization are generated. The use of annular masks to reduce the area of the focal spot usually increases the magnitude of this phenomenon, known as depolarization. We present a class of masks, the three-ring masks, which are important because they narrow the central lobe of the focal intensity distribution without increasing the depolarization. This can be very useful in modern optical applications, such as confocal microscopy or multiphoton scanning microscopy.

Lightfield microscopy, an emerging tool for real-time 3D imaging

2020

Integral, or lightfield, microscopy offers the possibility of capturing and processing in real time multiple views of 3D fluorescent samples captured with a single shot. In this contribution we review the recent advances in lightfield microscopy and enunciate the forthcoming challenges.

Tunable axial superresolution by annular binary filters. Application to confocal microscopy

1995

We present a set of annular binary pupil filters for increasing the axial resolving capacity of imaging systems. The filters consist of two transparent annuli of the same area. It is shown that by changing the area of the transparent regions it is possible to obtain a tunable reduction of the width of the central lobe of the axial point spread function of the imaging system. However, this reduction is accompanied by a severe increase of the strength of secondary lobes, what can make these filters not very useful when used in conventional imaging systems. That is why we propose to use these filters for apodizing confocal microscopy systems. It is shown that in this case an important reductio…

In vivo real-time imaging of the liver with confocal endomicroscopy permits visualization of the temporospatial patterns of hepatocyte apoptosis.

2011

Apoptosis is a dynamic process of programmed cell death and is involved in multiple diseases. However, its mechanisms and sequence of events are still incompletely understood, partly because of the inability to visualize single cells continuously in vivo. The aim of the present study was to monitor hepatocyte apoptosis with confocal endomicroscopy in living rodents. In 73 anaesthetized mice, apoptotic liver injury was induced by injection of the CD95-agonistic antibody Jo2. Individual hepatocytes were followed for up to 240 min with a handheld confocal probe (FIVE1; Optiscan) providing 0.7 μm resolution (1,000-fold magnification). Different fluorescence staining protocols were used for cell…

Mass Spectrometry and Imaging Analysis of Nanoparticle-Containing Vesicles Provide a Mechanistic Insight into Cellular Trafficking

2014

Rational design of nanocarriers for drug delivery approaches requires an unbiased knowledge of uptake mechanisms and intracellular trafficking pathways. Here we dissected these processes using a quantitative proteomics approach. We isolated intracellular vesicles containing superparamagnetic iron oxide polystyrene nanoparticles and analyzed their protein composition by label-free quantitative mass spectrometry. The proteomic snapshot of organelle marker proteins revealed that an atypical macropinocytic-like mechanism mediated the entry of nanoparticles. We show that the entry mechanism is controlled by actin reorganization, atypical macropinocytic signaling, and ADP-ribosylation factor 1. A…

Uptake of silica covered Quantum Dots into living cells: Long term vitality and morphology study on hyaluronic acid biomaterials

2015

Quantum Dots (QDs) are promising very bright and stable fluorescent probes for optical studies in the biological field but water solubility and possible metal bio-contamination need to be addressed. In this work, a simple silica-QD hybrid system is prepared and the uptake in bovine chondrocytes living cells without any functionalization of the external protective silica shield is demonstrated. Moreover, long term treated cells vitality (up to 14 days) and the transfer of silica-QDs to the next cell generations are here reported. Confocal fluorescence microscopy was also used to determine the morphology of the so labelled cells and the relative silica-QDs distribution. Finally, we employ sil…