Search results for " Adhesion"
showing 10 items of 980 documents
Focal adhesions are hotspots for keratin filament precursor formation
2006
Recent studies showed that keratin filament (KF) formation originates primarily from sites close to the actin-rich cell cortex. To further characterize these sites, we performed multicolor fluorescence imaging of living cells and found drastically increased KF assembly in regions of elevated actin turnover, i.e., in lamellipodia. Abundant KF precursors (KFPs) appeared within these areas at the distal tips of actin stress fibers, moving alongside the stress fibers until their integration into the peripheral KF network. The earliest KFPs were detected next to actin-anchoring focal adhesions (FAs) and were only seen after the establishment of FAs in emerging lamellipodia. Tight spatiotemporal …
Differential evolution of PSA-NCAM expression during aging of the rat telencephalon
2007
Changes in the ability of neuronal networks to undergo structural remodeling may be involved in the age-associated cognitive decline. The polysialylated form of the neural cell adhesion molecule (PSA-NCAM) declines dramatically during postnatal development, but persists in several regions of the young-adult rat telencephalon, where it participates, through its anti-adhesive properties, in neuronal structural plasticity. However, PSA-NCAM expression during aging has only been studied in the dentate gyrus and the piriform cortex layer II, where it is strongly downregulated in adult (middle-aged) individuals. Using immunohistochemistry, we have observed that in most of the telencephalic areas …
Selective Adhesion of Cells from Different Telencephalic Regions
1996
AbstractWe asked whether specification of different regions of the rodent and avian telencephalon during development involved the acquisition of differential adhesive properties. Cells from different regions were aggregated in a short-term aggregation assay, and their segregation was analyzed. Both neurons and precursor cells from cortex segregate from striatal cells at early, but not later, stages, whereas cells from rodent neocortex and hippocampus segregated only during later stages. Segregation was abolished when Ca2+-dependent but not Ca2+-independent adhesion molecules were selectively removed. Thus, selective adhesion appears to be a conserved mechanism that restricts cellular mixing…
Distribution of PSA-NCAM expression in the amygdala of the adult rat.
2002
Synaptic plasticity in the amygdala appears to be necessary for the generation of emotional memories. However, the molecular bases of this plasticity are not fully understood. Because the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) has been implicated in memory consolidation in the hippocampus and temporal cortex, we have studied in detail the expression of this molecule in the adult rat amygdala with an antibody against PSA-NCAM. Our results demonstrate for the first time the presence of PSA-NCAM in the adult rat amygdala. Immunoreactive somata and processes are abundant in the amygdalo-hippocampal transition area, central nucleus, intra-amygdaloid bed nucleus of th…
Nickel induces intracellular calcium mobilization and pathophysiological responses in human cultured airway epithelial cells.
2009
Abstract Environmental exposure to nickel is associated to respiratory disorders and potential toxicity in the lung but molecular mechanisms remain incompletely explored. The extracellular Ca 2+ -sensing receptor (CaSR) is widely distributed and may be activated by divalent cations. In this study, we investigated the presence of CaSR in human cultured airway epithelial cells and its activation by nickel. Nickel transiently increased intracellular calcium (−log EC 50 = 4.67 ± 0.06) in A549 and human bronchial epithelial cells as measured by epifluorescence microscopy. Nickel (20 μM)-induced calcium responses were reduced after thapsigargin or ryanodine exposure but not by Ca 2+ -free medium…
L'intonaco Li Vigni nell'architettura del XX secolo a Palermo. Nuove conoscenze e applicazioni diagnostiche per la manutenzione
2013
Il saggio presenta lo studio degli intonaci formulati per imitare le pietre e i marmi naturali che si diffondono in Sicilia all’inizio del XX secolo ed evidenzia che le prime applicazioni e la diffusione delle nuove malte, anche nel resto dell’Italia, risentono delle sperimentazioni condotte in tutta l’Europa. Il contributo riassume i risultati di una rigorosa e capillare ricognizione tra i brevetti conservati presso l’Archivio Centrale dello Stato a Roma inerenti alle malte per il confezionamento dell’intonaco a “finta pietra”, ne analizza i contenuti in modo critico e pone in risalto i contatti culturali con le sperimentazioni dei materiali in atto nell’ambito dei grandi cantieri di resta…
The effect of ions at the surface of calcium oxalate monohydrate crystals on cell-crystal interactions
2003
Magnesium is an abundant ion in biologic systems, including renal tubular fluid; however, the precise role of magnesium during the interaction of calcium oxalate crystals with cells has not been previously defined. In addition, the respective roles of calcium and hydrogen ions during the cell-crystal bonding interaction remain poorly defined. Here we report an atomic level three-dimensional study of a single crystal of calcium oxalate monohydrate (COM; whewellite) which was bathed in a solution of magnesium hexahydrate for 1 year. Magnesium was not incorporated into the structure of whewellite to any significant degree. Instead, COM accepted magnesium primarily as an adsorbate in a binding …
Promotion of osteogenic cell response using quasicovalent immobilized fibronectin on titanium surfaces: introduction of a novel biomimetic layer syst…
2012
Purpose Despite the undeniable potential of cell adhesion molecules such as fibronectin to support osteogenic cell responses and consecutive dental implant healing, the most beneficial mode of application onto titanium implant surfaces still requires investigation. Unspecific fibronectin adsorption on titanium dioxide (TiO2) surfaces can result in low-loading, high-desorption rates and protein–metal interactions with impaired biologic activity. The aim of the present study was to monitor the osteogenic cell responses (cell adhesion, proliferation, and differentiation) specifically to fibronectin biofunctionalized TiO2. Materials and Methods An innovative biomimetic streptavidin-biotin layer…
Effects of cyclooxygenase-1/cyclooxygenase-2 inhibition on leukocyte/endothelial cell interactions in the rat mesentery.
2002
Nonsteroidal anti-inflammatory drugs (NSAID) inhibit cyclooxygenase activity and cause gastrointestinal damage in part by promoting leukocyte accumulation in the mucosa. Our aim was to evaluate the effects of selective blockade of the isoenzymes cyclooxygenase-1 and cyclooxygenase-2 on leukocyte adhesion in vivo. Leukocyte/endothelial cell interactions were examined in rat mesenteric venules before and after treatment with indomethacin, SC-560 (5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole, cyclooxygenase-1 inhibitor), DFP (5,5-dimethyl-3-(2-propoxy)-4-(4-methanesulfonyl)-2(5H)-furanone, cyclooxygenase-2 inhibitor), or SC-560 plus DFP (20 mg/kg, i.v. each). Indomethacin i…
Desmosomes: interconnected calcium-dependent structures of remarkable stability with significant integral membrane protein turnover
2002
Desmosomes are prominent cell adhesion structures that are major stabilizing elements, together with the attached cytoskeletal intermediate filament network, of the cytokeratin type in epithelial tissues. To examine desmosome dynamics in tightly coupled cells and in situations of decreased adhesion, fluorescent desmosomal cadherin desmocollin 2a (Dsc2a) chimeras were stably expressed in human hepatocellular carcinoma-derived PLC cells (clone PDc-13) and in Madin-Darby canine kidney cells (clone MDc-2) for the continuous monitoring of desmosomes in living cells. The hybrid polypeptides integrated specifically and without disturbance into normal-appearing desmosomes that occurred in associati…