Search results for "CELLULAR"
showing 10 items of 6449 documents
A core cochlear phenotype in USH1 mouse mutants implicates fibrous links of the hair bundle in its cohesion, orientation and differential growth
2008
The planar polarity and staircase-like pattern of the hair bundle are essential to the mechanoelectrical transduction function of inner ear sensory cells. Mutations in genes encoding myosin VIIa, harmonin, cadherin 23,protocadherin 15 or sans cause Usher syndrome type I (USH1, characterized by congenital deafness, vestibular dysfunction and retinitis pigmentosa leading to blindness) in humans and hair bundle disorganization in mice. Whether the USH1 proteins are involved in common hair bundle morphogenetic processes is unknown. Here, we show that mouse models for the five USH1 genetic forms share hair bundle morphological defects. Hair bundle fragmentation and misorientation (25-52° mean ki…
Studies on DNA interaction of organotin(IV) complexes of meso-tetra(4-sulfonatophenyl)porphine that show cellular activity.
2016
PubMedID: 27393277 The interaction of the diorgano- and triorganotin(IV) derivatives of meso-tetra-(4-sulfonatophenyl)porphine (Me2Sn)2TPPS, (Bu2Sn)2TPPS, (Me3Sn)4TPPS and (Bu3Sn)4TPPS to natural DNA was analysed (together with free meso-tetra-(4-sulfonatophenyl)porphine (TPPS4 -) for comparison purposes). Particular attention was paid to (Bu3Sn)4TPPS, a species that shows significant cellular action. Preliminary tests were done on the solution properties of the organotin(IV) compounds (pKA and possible self-aggregation). Spectrophotometric and spectrofluorometric experiments showed that all the investigated organotin(IV) derivatives strongly interact with DNA, the binding energy depending …
Investigation of Temperature-Induced Phase Transitions in DOPC and DPPC Phospholipid Bilayers Using Temperature-Controlled Scanning Force Microscopy
2004
Under physiological conditions, multicomponent biological membranes undergo structural changes which help define how the membrane functions. An understanding of biomembrane structure-function relations can be based on knowledge of the physical and chemical properties of pure phospholipid bilayers. Here, we have investigated phase transitions in dipalmitoylphosphatidylcholine (DPPC) and dioleoylphosphatidylcholine (DOPC) bilayers. We demonstrated the existence of several phase transitions in DPPC and DOPC mica-supported bilayers by both atomic force microscopy imaging and force measurements. Supported DPPC bilayers show a broad L(beta)-L(alpha) transition. In addition to the main transition …
A Theoretical Learning Model Combining Stochastic Cellular Automata and Economic Indicators to Simulate Land Use Change
2015
The study of change in land use has been included in territorial planning to inform spatial planners and policy makers of the possible developments they face in order to optimize future management decisions. In this paper the authors present the core of an original learning model coupling stochastic Cellular Automata and economic indicators to simulate the land use change. This model is an important step in building an “environmental virtual laboratory” to explore, explain and forecast land use change.
Analysis of the polypeptide composition of the cell walls of Neurospora crassa. Similarities with the proteinaceous material secreted by the slime va…
1991
The polypeptide composition of cell walls from the wild-type strain of Neurospora crassa is compared with that of the proteinaceous extracellular coat (PEM) secreted by the slime strain of this fungus. Analyses included determination of the polypeptide pattern by polyacrylamide gel electrophoresis and blotting followed by staining with Concanavalin A and antibodies raised against the overall antigenic components present in either (whole cell walls or PEM) structure. A complex protein assortment was found associated to the walls of the wild type strain. The similarities observed between the polypeptide patterns of the cell walls and PEM, in addition to the immunological cross-reactivity exhi…
Strategie di difesa in risposta a stress in embrioni di riccio di mare: L'embrione di riccio di Paracentrotus lividus come modello sperimentale per l…
2013
Negli ultimi decenni, grazie alle nuove tecnologie e alla maggiore disponibilità di strumenti di ricerca, il campo riguardante lo studio delle strategie di difesa attivate nella risposta a stress, compresi i meccanismi di apoptosi e autofagia, è divenuto molto ampio ed è in continua espansione. Sin dagli albori della Biologia, gli studi condotti sul modello sperimentale di riccio di mare hanno permesso di ottenere conoscenze di base, spesso applicabili ad altri modelli biologici. I dati riportati nel presente libro dovrebbero aiutare a far luce sui meccanismi di difesa che le cellule sono in grado di attivare, in caso di necessità, se esposte a sfavorevoli condizioni ambientali. Le osservaz…
Mutation of a critical tryptophan to lysine in avidin or streptavidin may explain why sea urchin fibropellin adopts an avidin-like domain
1999
Sea urchin fibropellins are epidermal growth factor homologues that harbor a C-terminal domain, similar in sequence to hen egg-white avidin and bacterial streptavidin. The fibropellin sequence was used as a conceptual template for mutation of designated conserved tryptophan residues in the biotin-binding sites of the tetrameric proteins, avidin and streptavidin. Three different mutations of avidin, Trp-110-Lys, Trp-70-Arg and the double mutant, were expressed in a baculovirus-infected insect cell system. A mutant of streptavidin, Trp-120-Lys, was similarly expressed. The homologous tryptophan to lysine (W--K) mutations of avidin and streptavidin were both capable of binding biotin and bioti…
Protein-membrane interaction probed by single plasmonic nanoparticles.
2008
We present a nanosized and addressable sensor platform based on membrane coated plasmonic particles and show unequivocally the covering with lipid bilayers as well as the subsequent detection of streptavidin binding to biotinylated lipids. The binding is detected on membrane covered gold nanorods by monitoring the spectral shift by fast single particle spectroscopy (fastSPS) on many particles in parallel. Our approach allows for local analysis of protein interaction with biological membranes as a function of the lateral composition of phase separated membranes.
Metabolism and Lysine Biosynthesis Control in Brevibacterium Flavum: Impact of Stringent Response in Bacterial Cells
2005
Parameters affecting lysine biosynthesis by Brevibacterium flavum RC 115 cells under stringent response conditions (test guanosine 5′-diphosphate 3′-diphosphate accumulation in cells) caused by threonine limitation were investigated. Experimental results confirmed that an increase in lysine biosynthesis by this bacterium under stringent response conditions might be a result of an increase in the intracellular concentration of NADPH as well as lysine export activity.
The Marine Sponge-Derived Inorganic Polymers, Biosilica and Polyphosphate, as Morphogenetically Active Matrices/Scaffolds for the Differentiation of …
2014
The two marine inorganic polymers, biosilica (BS), enzymatically synthesized from ortho-silicate, and polyphosphate (polyP), a likewise enzymatically synthesized polymer consisting of 10 to >100 phosphate residues linked by high-energy phosphoanhydride bonds, have previously been shown to display a morphogenetic effect on osteoblasts. In the present study, the effect of these polymers on the differential differentiation of human multipotent stromal cells (hMSC), mesenchymal stem cells, that had been encapsulated into beads of the biocompatible plant polymer alginate, was studied. The differentiation of the hMSCs in the alginate beads was directed either to the osteogenic cell lineage by …