177,101 research outputs found
Single-molecule localization to study cytoskeletal structures, membrane complexes, and mechanosensors
No full textIn the last decades, a promising breakthrough in fluorescence imaging was represented by the advent of super-resolution microscopy (SRM). Super-resolution techniques recently became a popular method to study sub-cellular structures, providing a successful approach to observe cytoskeletal and focal adhesion proteins. Among the SR techniques, single-molecule localization microscopy plays a significant role due to its ability to unveil structures and molecular organizations in biological systems. Furthermore, since they provide information at the molecular level, these techniques are increasingly being used to study the stoichiometry and interaction between several membrane channel proteins and their accessory subunits. The aim of this review is to describe the single-molecule localization-based techniques and their applications relevant to cytoskeletal structures and membrane complexes in order to provide as future prospective an overall picture of their correlation with the mechanosensor channel expression and activity
Patch-clamp recordings in isolated sponge cells (Axinella polypoides)
No full textSponges are the most ancient known metazoans. Their cells are specialised but not organised into tissues or organs. Recordings of action potential-like propagating electrical impulses suggested that electrical signalling may occur between sponge cells, but the characterization of ionic channels in these cells is still at the beginning. Actually, sponge cell surfaces are covered by a complex glycocalyx and long-chain fatty acids are present in the lipid core of their membranes. In these experimental conditions, a low percentage of tight seals (3%) was obtained applying the patch-clamp technique to cells isolated from the Mediterranean Demospongia Axinella polypoides. This paper shows in detail how difficulties can be overcome making use of trivalent cations in the extracellular solution and how electrophysiological measurements can be performed on sponge cell membranes. A potassium selective conductance is shown as an example. We suggest that the presented methodology could also be applied to other cell types
Spunti per una futura ricerca su giustizia costituzionale ed equilibri istituzionali
No full textTendenze evolutive del controllo di costituzionalità e spunti per la riconsiderazione delle consolidate classificazioni in materi
Flavobacteria as intracellular symbionts in cockroaches
No full textAnimal cells are the sole habitat for a variety of bacteria. Molecular sequence data have been used to position a number of these intracellular microorganisms in the overall scheme of eubacterial evolution. Most of them have been classified as proteobacteria or chlamydiae. Here we present molecular evidence placing an intracellular symbiont among the flavobacteria-bacteroides. This microorganism inhabits specialized cells in the cockroach fat body and has been described as a mutualistic endosymbiont of uncertain phylogenetic position. The small subunit ribosomal DNA of these bacteria was analysed after polymerase chain reaction amplification to investigate their phylogeny. The endosymbionts of five species of cockroaches were found to make up a coherent group with no close relatives within the eubacterial phylum defined by the flavobacteria. In addition, the relationships among the endosymbionts, as revealed by DNA sequence data, appeared to be congruent with the host taxonomic relationships. Based on the host fossil record, a tentative calibration of the nucleotide substitution rate for the cockroach flavobacteria gave results congruent with those obtained for the aphid endosymbiotic proteobacteria
Pneumocephalus due to granulomatosis with polyangiitis
No full textA 67-year-old woman affected by granulomatosis with polyangiitis (GPA) presented with a flare of lung disease and ulceration of the lower limb without active sinusitis. She had a 9-year history of GPA with pulmonary and ENT involvement, the latter leading to left eye enucleation (histological findings suggestive of GPA). She had initially been treated with CYC (6 months) and was currently on
steroids and MTX. Laboratory studies revealed raised inflammatory markers and cANCA (PR3) positivity. Thoracic CT showed progression of bilateral ground-glass opacities; bronchoalveolar lavage excluded infections. Methylprednisolone 1 mg/kg was introduced with clinical
improvement. However, she gradually developed episodic headache and a mild, fluctuant altered mental status with confusion and delayed verbal response without other neurological features. A coronal T2-weighted MRI (Fig. 1)revealed a previously known, unmodified ischaemic lesion and the presence of extensive pneumocephalus secondary to cerebrospinal fluid leakage through multiple discontinuities
in the ethmoid bone due to chronic localization of GPA to the anterior skull base (without other risk factors for development of pneumocephalus). Pneumocephalus due to cerebrospinal fluid fistula is usually secondary to trauma or surgery [1], but to our knowledge has never been reported as a complication of skull base involvement in GPA
Nanocapsules: Coating for living cells
No full textOne of the most promising tools for future applications in science and medicine is the use of nanotechnologies. Especially self-assembly systems, e.g., polyelectrolyte (PE) capsules prepared by means of the layer-by-layer technique with tailored properties, fulfill the requirements for nano-organized systems in a satisfactory manner. The nano-organized shells are suitable as coating for living cells or artificial tissue to prevent immune response. With these shells, material can be delivered to predefined organs. In this paper, some preliminary results are presented, giving a broad overview over the possibilities to use nano-organized capsules. Based on the observations that the cells while duplicating break the capsule a mutant yeast strain (Saccharomyces cerevisiae), which express GFP-tubulin under galactose promotion, was investigated by means of confocal laser scanning microscopy. The measurements reveal an increased surface charge in the region of buds developed prior encapsulation. In order to test the used PE pair for cytotoxicity, germinating conidia of the fungi Neurospora crassa were coated. The investigation with fluorescence microscopy shows a variation in the surface charge for the growing region and the conidium poles. The capsules exhibit interesting properties as valuable tool in science and a promising candidate for application in the field of medicine
Protection capabilities of nanostructured shells toward cell encapsulation: a Saccharomyces/Paramecium model
No full textIn this work we report the formation of nanostructured hybrid objects, made up of living cells encapsulated in a protective multilayer shell assembly of nanostructured polyelectrolyte. Such constructs can be hosted on nanostructured surfaces or can be installed around living organisms, at the right time. Their construction is based on the layer-by-layer (LbL) self-assembly of two oppositely alternated charged polyelectrolytes (PEs) on cell membranes as earlier done for nanocapsules or fuzzy structured nanoshells. This communication reports the optimal conditions for cell encapsulation in terms of nanoshell design and construction
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
La responsabilità politica del giudice: un concetto da declinare al plurale
No full textMuovendo da una breve analisi comparata, il saggio critica gli argomenti di chi respinge l'idea stessa di una responsabilità politica del giudice. Dopo aver considerato gli sviluppi in atto su scala europea, relativamente alle forme di governo della magistratura, considera criticamente la formula dell'autogoverno, così come proposto dalla CCJE. Avvalendosi della teoria della delega, il saggio presenta disegni istituzionali alternativi di governance della magistratura che sembrano trovare riscontro in alcuni sistemi della UE
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