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51.
Natalia F. Avrova Tatyana V. Sokolova Yulia A. Vlasova Irina O. Zakharova Victor V. Furaev Maria P. Rychkova 《Neurochemical research》2010,35(1):85-98
GM1 ganglioside was found to increase the survival of PC12 cells exposed to H2O2, its action was blocked by Trk tyrosine kinase inhibitor K-252a. Thus, the inhibition of H2O2 cytotoxic action by GM1 constituted 52.8 ± 4.3%, but in the presence of 1.0 μM K-252a it was only 11.7 ± 10.8%, i.e. the
effect of GM1 became insignificant. Exposure to GM1 markedly reduced the increased accumulation of reactive oxygen species
(ROS) and diminished the inactivation of Na+,K+-ATPase induced in PC12 cells by H2O2, but in the presence of K-252a GM1 did not change these metabolic parameters. The inhibitors of extracellular signal-regulated
protein kinase, phosphatidyl inositol 3-kinase and protein kinase C decreased the effects of GM1. A combination of these protein
kinase inhibitors reduced inhibition of H2O2 cytotoxic action by GM1 to the larger extent than each of the inhibitors and practically abolished the ability of GM1 to
decrease H2O2-induced ROS accumulation. The protective and antioxidative effects of GM1 in PC12 cells exposed to H2O2 appear to be mediated by activation of Trk receptor tyrosine kinase and the protein kinases downstream from this enzyme. 相似文献
52.
Awake mammals are often inattentive in familiar environments, but must still respond appropriately to relevant visual stimulation. Such "inattentive vision" has received little study, perhaps due to difficulties in controlling eye position in this state. In rabbits, eye position is exceedingly stable in both alert and inattentive states. Here, we exploit this stability to examine temporal filtering of visual information in LGNd neurons as rabbits alternate between EEG-defined states. Within a single second of shifting from alert to an inattentive state, both peak temporal frequency and bandwidth were sharply reduced, and burst frequency increased dramatically. However, spatial dimensions of receptive field centers showed no significant state dependence. We conclude that extremely rapid and significant changes in temporal filtering and bursting occur in the LGNd as awake subjects shift between alert and inattentive states. 相似文献
53.
54.
Kraus YA 《The International journal of developmental biology》2006,50(2-3):267-275
The factors governing the pattern formation process in the early morphogenesis of a marine colonial hydroid, Dynamena pumila, have been studied. Two different types of morphogenesis have been distinguished. Morphogenesis of the first type goes on via changes in cell shape and cell axis orientation, while morphogenesis of the second type is based upon the active coordinated cell movements associated with cell rearrangements. It was shown that morphogenesis of both types can be considered as cascades in which any event is a consequence of the previous one. The spatial structure of each developmental stage contains information about the direction and the initial conditions of further morphogenesis. So, an "epigenetic program" of morphogenesis gradually originates in the course of development and provides the stable reproduction of spatial structures. It is reasonable to consider the activity of epigenetic factors guiding Dynamena morphogenesis (geometry/topology of an embryo, heterogeneity of an embryo spatial structure, configuration of the field of mechanical stresses of the embryo surface) as "morphomechanical programming" of morphogenesis. 相似文献
55.
Arabidopsis RNA-binding protein UBA2a relocalizes into nuclear speckles in response to abscisic acid
The Arabidopsis thaliana RNA binding protein UBA2a is the closest homologue of the Vicia faba AKIP1 (56% identity). Like AKIP1, UBA2a is a constitutively-expressed nuclear protein and in response to ABA it is also reorganized within the nucleus in "speckles" suggesting a possible role of this protein in the regulation of mRNA metabolism during ABA signaling. AKIP1 interacts with, and is phosphorylated by, the upstream ABA-activated protein kinase AAPK. We have investigated if a pathway similar to that described in Vicia faba also exists in Arabidopsis. Our results showed that despite the resemblance between the corresponding Vicia and Arabidopsis proteins, it appears that the function of UBA2a is independent of OST1 phosphorylation. 相似文献
56.
Tatiana Sitnikova Ellinor Michel Yulia Tulupova Igor Khanaev Valentina Parfenova Larisa Prozorova 《Symbiosis (Philadelphia, Pa.)》2012,56(3):103-110
We describe the first records of spirochetes in the gut of fourteen species of continental gastropods from a range of habitats and representing six families (Amnicolidae, Baicaliidae, Bithyniidae, Pyrgulidae, Lithoglyphidae and Benedictiidae). The bacteria were mainly found in the crystalline style sac, as has been reported in marine bivalves. The surveyed habitats include water bodies in North America and Eurasia, including deep water hydrothermal vent and gas hydrate zones in Lake Baikal. Spirochetes were present both in mature and young snails, but were not detected in embryos before hatching, indicating lateral transfer. The surveyed gastropods range in trophic strategy, including phyto-, detrito- and bacteriophagous grazers and filter feeders. Our results indicate that spirochetes are commensal in the surveyed gastropods with potential limited benefit and no detriment to the host animal. We suggest that the specialized internal habitat of the crystalline style sac in molluscs is likely to reveal unrecognized spirochete diversity that will shed new light on gastropod trophic ecology and spirochete diversity. 相似文献
57.
Assembly and maintenance of nodes of ranvier rely on distinct sources of proteins and targeting mechanisms 总被引:1,自引:0,他引:1
Zhang Y Bekku Y Dzhashiashvili Y Armenti S Meng X Sasaki Y Milbrandt J Salzer JL 《Neuron》2012,73(1):92-107
We have investigated the source(s) and targeting of components to PNS nodes of Ranvier. We show adhesion molecules are freely diffusible within the axon membrane and accumulate at forming nodes from local sources, whereas ion channels and cytoskeletal components are largely immobile and require transport to the node. We further characterize targeting of NF186, an adhesion molecule that pioneers node formation. NF186 redistributes to nascent nodes from a mobile, surface pool. Its initial accumulation and clearance from the internode require extracellular interactions, whereas targeting to mature nodes, i.e., those flanked by paranodal junctions, requires intracellular interactions. After incorporation into the node, NF186 is immobile, stable, and promotes node integrity. Thus, nodes assemble from two sources: adhesion molecules, which initiate assembly, accumulate by diffusion trapping via interactions with Schwann cells, whereas ion channels and cytoskeletal components accumulate via subsequent transport. In mature nodes, components turnover slowly and are replenished via transport. VIDEO ABSTRACT: 相似文献
58.
Smol'kina ON Shishonkova NS Fedonenko YP Zdorovenko EL Konnova SA Ignatov VV 《Carbohydrate research》2012,347(1):161-163
A method is developed for the preparation of D-rhamnose from an O-polysaccharide (OPS) isolated by mild acid hydrolysis of Azospirillum brasilense SR75 cell mass. After the OPS hydrolysis, D-rhamnose was recovered by gel-permeation chromatography on Toyopearl TSK HW-40 and was crystallized. The sugar activity was demonstrated immunochemically. The advantages of the method are that it expedites and simplifies the extraction of D-rhamnose and increases its yield. 相似文献
59.
Tyurina YY Tungekar MA Jung MY Tyurin VA Greenberger JS Stoyanovsky DA Kagan VE 《FEBS letters》2012,586(3):235-241
Peroxidation of cardiolipin in mitochondria is essential for the execution of apoptosis. We suggested that integration of oleic acid into cardiolipin generates non-oxidizable cardiolipin species hence protects cells against apoptosis. We synthesized mitochondria-targeted triphenylphosphonium oleic acid ester. Using lipidomics analysis we found that pretreatment of mouse embryonic cells with triphenylphosphonium oleic acid ester resulted in decreased contents of polyunsaturated cardiolipins and elevation of its species containing oleic acid residues. This caused suppression of apoptosis induced by actinomycin D. Triacsin C, an inhibitor of acyl-CoA synthase, blocked integration of oleic acid into cardiolipin and restored cell sensitivity to apoptosis. 相似文献
60.
M. V. Il’ina A. V. Timofeeva V. T. Ivanova E. I. Burtseva L. A. Baratova I. Yu. Sapurina G. S. Katrukha 《Applied Biochemistry and Microbiology》2012,48(8):699-704
A modern nanomaterial made of Taunit multiwalled carbon nanotubes (MWCNTs) was used for the first time to adsorb and desorb gramicidin S and teicoplanin A2 polypeptide antibiotics. Taunit was found to absorb efficiently antibiotics under particular conditions when MWCNTs were taken in excess at 20°C for 18 h. The desorption efficiency depended on the eluent content and the structure of antibiotics. The teicoplanin A2 antibiotic was eluted with a higher yield because of its higher polarity compared to gramicidin S (86% against 65% of the total Taunit-bound antibiotic). 相似文献