Search results for "Histology"

Estimation of Microbial Viability Using Flow Cytometry.

2020

For microorganisms in particular, viability is a term that is difficult to define and a state consequently difficult to measure. The traditional (and gold standard) usage equates viability and culturability (i.e., the ability to multiply) but the process of determining culturability is often too slow. Flow cytometry provides the opportunity to make rapid and quantitative measurements of dye uptake in large numbers of cells and we can therefore exploit the flow cytometric approach to evaluate so-called viability stains and to develop protocols for more routine assessments of microbial viability. This article provides a commentary and several protocols have been included to ensure that users …

Origin of neuronal-like receptors in Metazoa: cloning of a metabotropic glutamate/GABA-like receptor from the marine sponge Geodia cydonium.

1999

To date, no conclusive evidence has been presented for the existence of neuronal-like elements in Porifera (sponges). In the present study, isolated cells from the marine sponge Geodia cydonium are shown to react to the excitatory amino acid glutamate with an increase in the concentration of intracellular calcium [Ca2+]i. This effect can also be observed when the compounds L-quisqualic acid (L-QA) or L-(+)-2-amino-4-phosphonobutyric acid (L-AP-4) are used. The effect of L-QA and L-AP-4, both agonists for metabotropic glutamate receptors (mGluRs), can be abolished by the antagonist of group I mGluRs, (RS)-alpha-methyl-4-carboxyphenylglycine. These data suggest that sponge cells contain an mG…

Single molecules probe local density of modes (LDOS) around photonic nanostructures

2008

International audience; According to Fermi's golden rule, the fluorescence decay rate is directly proportional to the projected local density of photonic modes (LDOS) at the molecule location. The relevant LDOS depends on the molecule orientation. In this paper, the direct measurement of the fluorescence lifetime near gold dot photonic structures is investigated and compared to calculated LDOS. Detailed analysis of the decay channels is presented on the basis of numerical simulations.

Light field propagation by metal micro- and nanostructures

2001

The ability to sustain plasmon oscillations gives rise to unique properties of metal nanostructures, which can be exploited for the controlled manipulation of light fields on the nanoscale. In this context we investigate electromagnetic coupling effects within lithographically produced ensembles of gold nanoparticles with a photon scanning tunnelling microscope. To provide an interface between these nano-optical devices and classical far-field optics, we investigate surface plasmon propagation on microstructured metal thin films.

Analysis of NO synthase expression in neuronal, astroglial and fibroblast-like derivatives differen-tiating from PCC7-Mzl embryonic carcinoma cells

1999

We studied the expression of the NO synthase isoforms in an in vitro model of neural development using RT-PCR, Western blot and immu- nohistochemistry. Murine PCC7-Mzl cells (Jostock et al., Eur. J. Cell Biol. 76, 63–76,1998) differentiate in the presence of all-trans retinoic acid and dibutyryl cAMP along the neural pathway into neuron-like, fibroblast-like and astroglia-like cells. Undifferentiated cells showed immunofluorescent staining for neuronal-type NOSI and endothelial- type NOS III. This expression pattern was retained in those cells differ entiating into neurofilament- and tau protein-positive neuronal cells. Thymocyte alloantigen (Thyl.2/CD 90.2)-positive Fibroblasts, appearing …

Vimentin and desmin of a cartilaginous fish, the shark Scyliorhinus stellaris: Sequence, expression patterns and in vitro assembly

2002

In the shark Scyliorhinus stellaris we have biochemically identified and cDNA-cloned orthologs of human vimentin and desmin, SstV and SstD, as deduced from immunoblotting and sequence alignment with teleost, frog and human vimentin and desmin, respectively. This allowed us to further clarify the relationship of previously identified lower vertebrate intermediate filament proteins to mammalian vimentin and desmin. Immunofluorescence microscopy with antibodies H5 and VIM13.2 showed vimentin expression in shark eye and brain and absence in epithelia, which resembles the situation in higher vertebrates. In addition, SstV is expressed in many mesenchymal cell types which corresponds to the case …

Juvenile autophagic vacuolar myopathy - a new entity or variant?

2013

What Symbionts Teach us about Modularity

2013

The main goal of Synthetic Biology is to apply engineering principles to biotechnology in order to make life easier to engineer. These engineering principles include modularity: decoupling of complex systems into smaller, orthogonal subsystems that can be used in a range of different applications. The successful use of modules in engineering is expected to be reproduced in synthetic biological systems. But the difficulties experienced up to date with synthetic biology approaches question the short-term feasibility of designing life. Considering the “engineerable” nature of life, here we discuss the existence of modularity in natural living systems, particularly in symbiotic interactions, an…

Extracellular vesicles in parasitic diseases

2014

Parasitic diseases affect billions of people and are considered a major public health issue. Close to 400 species are estimated to parasitize humans, of which around 90 are responsible for great clinical burden and mortality rates. Unfortunately, they are largely neglected as they are mainly endemic to poor regions. Of relevance to this review, there is accumulating evidence of the release of extracellular vesicles (EVs) in parasitic diseases, acting both in parasite parasite inter-communication as well as in parasite host interactions. EVs participate in the dissemination of the pathogen and play a role in the regulation of the host immune systems. Production of EVs from parasites or paras…

A cytochemical study on the effects of energy deprivation on autophagocytosis in Ehrlich ascites tumor cells

1988

The effect of energy deprivation on autophagocytosis in Ehrlich ascites tumor cells was studied using cytochemical techniques. Autophagocytosis was induced with vinblastine incubation (0.1 mM) and the cellular ATP-level was lowered with 2-deoxy-D-glucose (0.35 mM). Acid phosphatase was used as a marker for lysosomal enzymes and imidazole-buffered osmium tetroxide impregnation in order to study the effects of energy deprivation on the maturation of autophagic vacuole (AV) membranes. Control and vinblastine treated cells maintained their ATP-levels throughout the incubation period tested (120 min). 2-Deoxy-D-glucose alone and with vinblastine decreased the intracellular ATP-level significantl…