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991.
TiCl3(thf)3 reacts with ACl (A = NBu4, PPN; PPN = Ph3PNPPh3) in dichloromethane solution, affording the compounds A[TiCl4(thf)2] (A = NBu4, 1; A = PPN, 2). Compound 1, dissolved in CH2Cl2, exhibits thermochromic behaviour which has been the subject of variable-temperature UV-Vis investigations. 相似文献
992.
Smits TH Rezzonico F Kamber T Goesmann A Ishimaru CA Stockwell VO Frey JE Duffy B 《Journal of bacteriology》2010,192(24):6486-6487
Pantoea vagans is a Gram-negative enterobacterial plant epiphyte of a broad range of plants. Here we report the 4.89-Mb genome sequence of P. vagans strain C9-1 (formerly Pantoea agglomerans), which is commercially registered for biological control of fire blight, a disease of pear and apple trees caused by Erwinia amylovora. 相似文献
993.
The Novel PMCA2 Pump Mutation Tommy Impairs Cytosolic Calcium Clearance in Hair Cells and Links to Deafness in Mice 总被引:1,自引:0,他引:1
Mario Bortolozzi Marisa Brini Nick Parkinson Giulia Crispino Pietro Scimemi Romolo Daniele De Siati Francesca Di Leva Andrew Parker Saida Ortolano Edoardo Arslan Steve D. Brown Ernesto Carafoli Fabio Mammano 《The Journal of biological chemistry》2010,285(48):37693-37703
The mechanotransduction process in hair cells in the inner ear is associated with the influx of calcium from the endolymph. Calcium is exported back to the endolymph via the splice variant w/a of the PMCA2 of the stereocilia membrane. To further investigate the role of the pump, we have identified and characterized a novel ENU-induced mouse mutation, Tommy, in the PMCA2 gene. The mutation causes a non-conservative E629K change in the second intracellular loop of the pump that harbors the active site. Tommy mice show profound hearing impairment from P18, with significant differences in hearing thresholds between wild type and heterozygotes. Expression of mutant PMCA2 in CHO cells shows calcium extrusion impairment; specifically, the long term, non-stimulated calcium extrusion activity of the pump is inhibited. Calcium extrusion was investigated directly in neonatal organotypic cultures of the utricle sensory epithelium in Tommy mice. Confocal imaging combined with flash photolysis of caged calcium showed impairment of calcium export in both Tommy heterozygotes and homozygotes. Immunofluorescence studies of the organ of Corti in homozygous Tommy mice showed a progressive base to apex degeneration of hair cells after P40. Our results on the Tommy mutation along with previously observed interactions between cadherin-23 and PMCA2 mutations in mouse and humans underline the importance of maintaining the appropriate calcium concentrations in the endolymph to control the rigidity of cadherin and ensure the function of interstereocilia links, including tip links, of the stereocilia bundle. 相似文献
994.
Markus Pfenninger Errol Véla Ruth Jesse Miren Arantzazu Elejalde Fabio Liberto Frédéric Magnin Alberto Martínez-Ortí 《Molecular phylogenetics and evolution》2010,54(2):427-436
The land snail genus Tudorella shows a peculiar disjunct distribution around the western Mediterranean coasts. Despite high phenotypic plasticity, only two species with a disputed number of subspecific taxa are currently recognised. We delimited the species with mitochondrial (COI & 16S) and nuclear (ITS-1) markers based on the unified species concept and suggested that there are eight species in the genus, two of them currently undescribed. Applying Bayesian phylogenetic model selection, we tested four different biogeographic hypotheses that could be causal for the current distribution pattern of extant Tudorella species. A scenario involving vicariance events resulting from the repeated splits of the Tyrrhenian plate with subsequent dispersal events over land bridges during the Pliocene received greatest support in the data. 相似文献
995.
Depletion of the periciliary liquid in "Cystic Fibrosis" airway disease results in reduced mucociliary transport, persistent mucus hypersecretion and consequently increased height of the luminal mucus layer, so hypoxic gradients in the mucus plugs are developed. Because of anaerobic lung zones, it is highly probable that anaerobic bacteria not detected by routine bacteriologic culture methods also reside within the mucus. Notwithstanding this evidence, microbiology laboratories working in the cystic fibrosis field do not generally use strict anaerobic bacteriologic cultures to determine the presence of anaerobic bacteria in the Cystic Fibrosis lung. The aim of this review is to focus on the published data regarding the finding of anaerobic bacteria in cystic fibrosis airway disease. Therefore, microbiology, diagnosis, antimicrobial susceptibility and possible impact on clinical management of anaerobic bacteria lung infection in cystic fibrosis are described. 相似文献
996.
Paromita Majumder Giulia Crispino Laura Rodriguez Catalin Dacian Ciubotaru Fabio Anselmi Valeria Piazza Mario Bortolozzi Fabio Mammano 《Purinergic signalling》2010,6(2):167-187
Connexin 26 (Cx26) and connexin 30 (Cx30) form hemichannels that release ATP from the endolymphatic surface of cochlear supporting
and epithelial cells and also form gap junction (GJ) channels that allow the concomitant intercellular diffusion of Ca2+ mobilizing second messengers. Released ATP in turn activates G-protein coupled P2Y2 and P2Y4 receptors, PLC-dependent generation of IP3, release of Ca2+ from intracellular stores, instigating the regenerative propagation of intercellular Ca2+ signals (ICS). The range of ICS propagation is sensitive to the concentration of extracellular divalent cations and activity
of ectonucleotidases. Here, the expression patterns of Cx26 and Cx30 were characterized in postnatal cochlear tissues obtained
from mice aged between P5 and P6. The expression gradient along the longitudinal axis of the cochlea, decreasing from the
basal to the apical cochlear turn (CT), was more pronounced in outer sulcus (OS) cells than in inner sulcus (IS) cells. GJ-mediated
dye coupling was maximal in OS cells of the basal CT, inhibited by the nonselective connexin channel blocker carbenoxolone
(CBX) and absent in hair cells. Photostimulating OS cells with caged inositol (3,4,5) tri-phosphate (IP3) resulted in transfer of ICS in the lateral direction, from OS cells to IS cells across the hair cell region (HCR) of medial
and basal CTs. ICS transfer in the opposite (medial) direction, from IS cells photostimulated with caged IP3 to OS cells, occurred mostly in the basal CT. In addition, OS cells displayed impressive rhythmic activity with oscillations
of cytosolic free Ca2+ concentration ([Ca2+]i) coordinated by the propagation of Ca2+ wavefronts sweeping repeatedly through the same tissue area along the coiling axis of the cochlea. Oscillations evoked by
uncaging IP3 or by applying ATP differed greatly, by as much as one order of magnitude, in frequency and waveform rise time. ICS evoked
by direct application of ATP propagated along convoluted cellular paths in the OS, which often branched and changed dynamically
over time. Potential implications of these findings are discussed in the context of developmental regulation and cochlear
pathophysiology. 相似文献
997.
998.
Anna M. Merendino Fabio Bucchieri Claudia Campanella Vito Marcianò Anna Ribbene Sabrina David Giovanni Zummo Giosalba Burgio Davide F. V. Corona Everly Conway de Macario Alberto J. L. Macario Francesco Cappello 《PloS one》2010,5(2)
Background
Hsp60, a Group I mitochondrial chaperonin, is classically considered an intracellular chaperone with residence in the mitochondria; nonetheless, in the last few years it has been found extracellularly as well as in the cell membrane. Important questions remain pertaining to extracellular Hsp60 such as how generalized is its occurrence outside cells, what are its extracellular functions and the translocation mechanisms that transport the chaperone outside of the cell. These questions are particularly relevant for cancer biology since it is believed that extracellular chaperones, like Hsp70, may play an active role in tumor growth and dissemination.Methodology/Principal Findings
Since cancer cells may undergo necrosis and apoptosis, it could be possible that extracellular Hsps are chiefly the result of cell destruction but not the product of an active, physiological process. In this work, we studied three tumor cells lines and found that they all release Hsp60 into the culture media by an active mechanism independently of cell death. Biochemical analyses of one of the cell lines revealed that Hsp60 secretion was significantly reduced, by inhibitors of exosomes and lipid rafts.Conclusions/Significance
Our data suggest that Hsp60 release is the result of an active secretion mechanism and, since extracellular release of the chaperone was demonstrated in all tumor cell lines investigated, our observations most likely reflect a general physiological phenomenon, occurring in many tumors. 相似文献999.
Borges TJ Porto BN Teixeira CA Rodrigues M Machado FD Ornaghi AP de Souza AP Maito F Pavanelli WR Silva JS Bonorino C 《PloS one》2010,5(12):e14264
Background
Heat shock proteins (Hsps) are stress induced proteins with immunomodulatory properties. The Hsp70 of Mycobacterium tuberculosis (TBHsp70) has been shown to have an anti-inflammatory role on rodent autoimmune arthritis models, and the protective effects were demonstrated to be dependent on interleukin-10 (IL-10). We have previously observed that TBHsp70 inhibited maturation of dendritic cells (DCs) and induced IL-10 production by these cells, as well as in synovial fluid cells.Methodology/Principal Findings
We investigated if TBHsp70 could inhibit allograft rejection in two murine allograft systems, a transplanted allogeneic melanoma and a regular skin allograft. In both systems, treatment with TBHsp70 significantly inhibited rejection of the graft, and correlated with regulatory T cells (Tregs) recruitment. This effect was not tumor mediated because injection of TBHsp70 in tumor-free mice induced an increase of Tregs in the draining lymph nodes as well as inhibition of proliferation of lymph node T cells and an increase in IL-10 production. Finally, TBHsp70 inhibited skin allograft acute rejection, and depletion of Tregs using a monoclonal antibody completely abolished this effect.Conclusions/Significance
We present the first evidence for an immunosuppressive role for this protein in a graft rejection system, using an innovative approach – immersion of the graft tissue in TBHsp70 solution instead of protein injection. Also, this is the first study that demonstrates dependence on Treg cells for the immunosuppressive role of TBHsp70. This finding is relevant for the elucidation of the immunomodulatory mechanism of TBHsp70. We propose that this protein can be used not only for chronic inflammatory diseases, but is also useful for organ transplantation management. 相似文献1000.
De Vico Fallani F Nicosia V Sinatra R Astolfi L Cincotti F Mattia D Wilke C Doud A Latora V He B Babiloni F 《PloS one》2010,5(12):e14187
Understanding the neural mechanisms responsible for human social interactions is difficult, since the brain activities of two or more individuals have to be examined simultaneously and correlated with the observed social patterns. We introduce the concept of hyper-brain network, a connectivity pattern representing at once the information flow among the cortical regions of a single brain as well as the relations among the areas of two distinct brains. Graph analysis of hyper-brain networks constructed from the EEG scanning of 26 couples of individuals playing the Iterated Prisoner's Dilemma reveals the possibility to predict non-cooperative interactions during the decision-making phase. The hyper-brain networks of two-defector couples have significantly less inter-brain links and overall higher modularity--i.e., the tendency to form two separate subgraphs--than couples playing cooperative or tit-for-tat strategies. The decision to defect can be "read" in advance by evaluating the changes of connectivity pattern in the hyper-brain network. 相似文献