Search results for "Staining"

An ethical algorithm for rationing life sustaining treatment during the COVID-19 pandemic

2020

The burning ethical question raised by the COVID-19 pandemic is how to deal fairly and ethically with a large number of patients simultaneously becoming critically unwell. Across the world, in both developed and developing countries, health systems are grappling with the possibility or the reality that the demand for intensive medical care will outstrip availability. There is a need for ethical guidelines on how to allocate treatment, but such guidelines are potentially highly controversial.1 In this commentary, we set out a simple algorithm (Figure 1), including what we take to be the essential ethical principles that ought to guide resource allocation in any country or setting as well as …

Characterization of murine monoclonal antibodies against the Ro52 autoantigen

1997

SUMMARY Immunization of BALB/c mice with purified recombinant human Ro52 protein resulted in three anti-Ro52 MoAbs termed 2E7, 4C6 and 4F11. All anti-Ro52 MoAbs specifically reacted with recombinant human Ro52 protein, and also with Ro52 protein in total extracts of all human cell lines analysed, including the epithelial cell line HeLa, the B cell line Raji, the bladder carcinoma cell line RT112, and a fibroblast cell line derived from patients with xeroderma pigmentosum. The anti-Ro52 MoAbs were able to immunoprecipitate the recombinant human Ro52 protein expressed in wheat germ extract, but failed to precipitate hY RNAs from cell extracts. The staining pattern of the MoAbs strongly differ…

Sea urchin embryos as a model system for studying autophagy induced by cadmium stress

2011

It is well known that sea urchin embryos are able to activate different defense strategies against stress. We previously demonstrated that cadmium treatment triggers the accumulation of metal in embryonic cells and the activation of defense systems depending on concentration and exposure time, through the synthesis of heat shock proteins and/or the initiation of apoptosis. Here we show that Paracentrotus lividus embryos exposed to Cd adopt autophagy as an additional stratagem to safeguard the developmental program. At present, there are no data focusing on the role of this process in embryo development of marine organisms. In this paper we utilized different techniques to detect autophagy i…

Light and electron microscopical demonstration of methylene blue accumulation sites in taste buds of fish and mouse after supravital dye injection

1995

Electron microscopical data regarding methylene blue staining of taste buds in the epithelia of the goldfish lip and the cirumvallate papilla of the mouse tongue after supravital dye application are presented for the first time. The ultrastructural details were compared with the corresponding light microscopical findings. The dye was applied in different concentrations by injection or in crystalline from directly to the surface of the tissues. Both methylene blue and tissue were simultaneously fixed by immersion in a paraformaldehyde-glutaraldehyde solution with the addition of phosphomolybdic acid. The ensuing dye precipitate was further stabilized by ammonium heptamolybdate. On the light …

Isolation of fibroblasts for coating of meshes for reconstructive surgery: differences between mesh types.

2009

Aims: An extensive colonization of surgical meshes with autologous fibroblasts may reduce complications. Therefore, we aimed to establish a technique that allows isolation and propagation of fibroblasts from vaginal biopsies. Using these cells we tested the applicability of several clinically applied meshes for fibroblast coating. Materials & methods: Fibroblasts were isolated from vaginal tissue after digestion with collagenase. Characterization was performed by immunostaining for cytokeratin 5, 6 and 14, smooth muscle actin and vimentin. A semiquantitative technique was applied to determine the degree of mesh coating 5 h and 5 weeks after seeding of fibroblasts. Seven meshes of diffe…

Combined effects of electric toothbrushing and dentifrice on artificial stain removal : an in vitro study

2018

This in vitro study aimed to clarify the combined effect of electric toothbrushing and dentifrice on the removal of artificial stain. Twenty-five bovine incisors were cut at the cervix and the crown was embedded in auto-cured acrylic resin. Specimens were abraded using #240 SiC paper to obtain a flat enamel surface, and 20 specimens were treated with 10% citric acid / 3% ferric chloride solution followed by 1% tannic acid solution to produce surface staining. They were divided into four groups: 1) brushing with an electric toothbrush and whitening dentifrice (group S+B); 2) brushing with an electric toothbrush and fluoride dentifrice (group S+C); 3) brushing with an electric toothbrush and …

Laboratory Technologies and Methodologies

2010

Caveolin 3, flotillin 1 and influenza virus hemagglutinin reside in distinct domains on the sarcolemma of skeletal myofibers.

2011

We examined the distribution of selected raft proteins on the sarcolemma of skeletal myofibers and the role of cholesterol environment in the distribution. Immunofluorescence staining showed that flotillin-1 and influenza hemagglutinin exhibited rafts that located in the domains deficient of the dystrophin glycoprotein complex, but the distribution patterns of the two proteins were different. Cholesterol depletion from the sarcolemma by means of methyl-β-cyclodextrin resulted in distorted caveolar morphology and redistribution of the caveolin 3 protein. Concomitantly, the water permeability of the sarcolemma increased significantly. However, cholesterol depletion did not reshuffle flotillin…

Phasor-FLIM analysis of Thioflavin T self-quenching in Concanavalin amyloid fibrils

2020

The formation of amyloid structures has traditionally been related to human neurodegenerative pathologies and, in recent years, the interest in these highly stable nanostructures was extended to biomaterial sciences. A common method to monitor amyloid growth is the analysis of Thioflavin T fluorescence. The use of this highly selective dye, diffused worldwide, allows mechanistic studies of supramolecular assemblies also giving back important insight on the structure of these aggregates. Here we present experimental evidence of self-quenching effect of Thioflavin T in presence of amyloid fibrils. A significant reduction of fluorescence lifetime of this dye which is not related to the propert…

Site-specific near-infrared fluorescent labelling of proteins on cysteine residues with meso -chloro-substituted heptamethine cyanine dyes

2018

International audience; Near-infrared (NIR) fluorescence imaging is a promising new medical imaging modality. Associated with a targeting molecule, NIR fluorophores can accumulate selectively in tissues of interest and become valuable tools for the diagnosis and therapy of various pathologies. To facilitate the design of targeted NIR imaging agents, it is important to identify simple and affordable fluorescent probes, allowing rapid labelling of biovectors such as proteins, ideally in a site-specific manner. Here, we demonstrate that heptamethine cyanine based fluorophores, such as IR-783, that contain a chloro-cyclohexyl moiety within their polymethine chain can react selectively, at neutr…