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111.
M. O. Emel’yanov Yu. A. Kim A. F. Korystova L. N. Kublik V. V. Shaposhnikova Yu. N. Korystov 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2010,4(2):212-219
The effect of a short-time (1 h) oxidative stress on multidrug resistance (MDR) of murine leukemic P388VR cells has been investigated.
We studied the production of reactive oxygen species (ROS) in cells depending on the composition of medium and the concentration
of cells and hydrogen peroxide, as well as the effect of hydrogen peroxide on MDR of cells. MDR was determined from the transport
of calcein acetoxymethyl ester out of the cells and from a change in cell sensitivity to vincristine. The amount of ROS arising
in cells was determined using 2′,7′-dichlorodihydrofluorescein diacetate (DCFH2-DA). It was shown that the rate of ROS formation in cells decreases after the addition of serum to the medium and with an
increase of the cell number. By the action of hydrogen peroxide, the amount of ROS increases directly with its concentration.
Oxidative stress generated by 30–300 μM hydrogen peroxide decreases the MDR of the cells. The effect of hydrogen peroxide
increases with the treatment duration and concentration of hydrogen peroxide. MDR determined by the criterion of the efflux
of calcein ester from cells is completely suppressed after 1-h exposure to 300 μM hydrogen peroxide. At a concentration of
hydrogen peroxide of 60 μM and treatment duration of 1 h, the sensitivity of P388VR cells to vincristine increases to reach
the sensitivity of the wild-type P388 cells. Rapid (about 1 h) suppression of MDR is caused by inhibition of the activity
of transport proteins. MDR decrease induced by oxidative stress can be used in therapy of tumors resistant to anticancer drugs. 相似文献
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113.
Burak Derkus Kaan Cebesoy Emregul Hidayet Mazi Emel Emregul Tugrul Yumak Ali Sinag 《Bioprocess and biosystems engineering》2014,37(5):965-976
A novel highly sensitive electrochemical impedimetric Protein A immunosensor for the determination of immunoglobulin G (IgG) was developed by immobilization of Protein A within a newly synthesized, and characterized polymer, poly(maleicanhydride-alt-decene-1). TiO2 nanoparticles (10–30 nm) were synthesized, characterized with X-ray diffraction, transmission electron microscopy and Brunauer–Emmett–Teller surface analysis. The electron transfer between IgG and the poly(maleicanhydride-alt-decene-1)-TiO2-Protein A is quasireversible with a formal potential of 225 mV vs Ag|AgCl. The response of the poly(maleicanhydride-alt-decene-1)-TiO2-Protein A immunosensor was proportional to IgG concentration with a correlation coefficient of 0.9963. The detection limit and linear range was 0.57 ng mL?1 and 0.0062–500 μg mL?1, respectively. Impedance measurments showed that synthesized TiO2 nanoparticles have better conducting properties compared with commercial degussa P25 TiO2 nanoparticles. The nonspecific binding of anti-MBP was 10 %. The label-free impedimetric immunosensor provided a simple and sensitive detection method for the specific determination of IgG in human serum. 相似文献
114.
Four palladium(II) and platinum(II) complexes of 2,2′-dipyridylamine (dpya) with saccharinate (sac), cis-[Pd(dpya)(sac)2]·H2O (1), cis-[Pt(dpya)(sac)2]·H2O (2), [Pd(dpya)2](sac)2·2H2O (3) and [Pt(dpya)2](sac)2·2H2O (4), have been synthesized and characterized by elemental analysis, IR, NMR, TG-DTA and X-ray diffraction. In 1 and 2, the metal ions are coordinated by two N-bonded sac ligands, and two nitrogen atoms of dpya, resulting in a neutral square-planar coordination sphere, while in 3 and 4, the metal ions are coordinated by two dpya ligands to generate square-planar cationic species, which are stabilized by two sac counter-ions. The mononuclear species of 1 and 2 interact each other through weak intermolecular N-H?O, C-H?O and π?π interactions to form a three-dimensional network, while the ions of 3 and 4 are connected by N-H?N and OW-H?O hydrogen bonds into one-dimensional chains. On heating at 250 °C, the solid cationic complexes of 3 and 4 convert to corresponding anhydrous neutral complexes of 1 and 2 after elimination of a dpya ligand. In addition, all complexes 1-4 are luminescent at room temperature and their emissions seem to be attributed to the MLCT fluorescence. 相似文献
115.
[Pd(sac)(terpy)](sac)·4H2O (1), [Pt(sac)(terpy)](sac)·5H2O (2), [PdCl(terpy)](sac)·2H2O (3) and [PtCl(terpy)](sac)·2H2O (4) (sac = saccharinate, and terpy = 2,2′:6′,2″-terpyridine) have been synthesized and characterized by elemental analysis, FT-IR, 1H NMR and 13C NMR. In 1 and 2, a tridentate terpy ligand together with an N-coordinated sac ligand form the square-planar geometry around the palladium(II) or platinum(II) ions, while one sac anion remains outside the coordination sphere as a counter-ion. X-ray single crystal studies show that the [M(sac)(terpy)]+ ions in 1 and 2 reside in the centers of a hydrogen bonded honeycomb network formed by the uncoordinated sac ions and the lattice water molecules. Complexes 3 and 4 are isostructural and consist of a [M(Cl)(terpy)]+ cation, a sac anion and two lattice water molecules. The [M(Cl)(terpy)]+ ions interact with each other via M-M and π-π stacking interactions and these π interacted units are assembled to a 2D network by water bridges involving the sac ions and lattice water molecules. Convenient synthetic paths for 1-4 are also presented, and spectral, luminescence and thermal properties were discussed. 相似文献
116.
Carolina Andrea Martínez Emel Topal Ana María Giulietti Julián Rodríguez Talou Hugh Mason 《Biotechnology letters》2010,32(6):867-875
Dengue virus envelope glycoprotein (E-protein) is the main protein associated with immunity induction. To produce a candidate
for subunit vaccines and to provide an antigen for diagnostic kits, it was expressed in a novel plant system using deconstructed
viral modules. A truncated version of the E-protein was designed to be expressed alone and co-expressed with Dengue virus
structural proteins. As well, the critical domain III of E-protein was fused to hepatitis B core antigen (HBcore). The recombinant
proteins were produced in Nicotiana benthamiana plants and were reactive with the anti-E antibody. The fusion was reactive with both anti-E and anti-HBcore antibodies. 相似文献
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118.
S. A. Zabelinskii M. A. Chebotareva E. N. Shukolyukova L. V. Emel’yanova M. V. Savina G. B. Belostotskaya 《Journal of Evolutionary Biochemistry and Physiology》2006,42(4):376-382
Lipids of blood plasma of lampreys and frogs are composed of phospholipids, triglycerides, free fatty acids (FA), cholesterol, cholesterol esters, and waxes. The lipids content in plasma of frogs is markedly lower as compared with that of lampreys. However, the percentage of lipid components is represented by close values. Fluidity of triglycerides and phospholipids in lampreys is determined predominantly by monoenic acids and polyenoic acids of the ω-3-type, whereas that in frogs—by monoenic acids and polyenic acids of the ω-6-type. Free FA are represented mainly by saturated and monoenic acids. 相似文献
119.
L. A. Baranova V. P. Emel’yanova E. V. Zhornik A. M. Minov L. V. Naumenko I. D. Volotovskii 《Biology Bulletin》2008,35(6):571-577
The main function of Csk tyrosine kinases is phosphorylation of the C-terminal part of Src tyrosine kinases as a mechanism of their downregulation. A decrease in the expression of csk gene results in the enhancement of Src tyrosine kinase activity. In this study, cDNA containing the full coding sequence of the human leukocyte Csk tyrosine kinase gene has been cloned. The protein encoded by a 1624-bp cDNA fragment has 99% homology to human Csk tyrosine kinase. A comparative sequence analysis of full-length cDNAs for Csk tyrosine kinase of normal lymphocytes and lymphocytes of patients with choroidal melanoma revealed a nucleotide substitution in exon 10 of the gene, which appears to be of diagnostic significance. It has been shown that the risk of choroidal melanoma correlated with the frequency of this allele. 相似文献
120.
Diversity and spatio-temporal distribution of ammonia-oxidizing Archaea and Bacteria in sediments of the Westerschelde estuary 总被引:10,自引:0,他引:10
The diversity and spatio-temporal distribution of ammonia-oxidizing Archaea (AOA) and Bacteria (AOB) were investigated along a salinity gradient in sediments of the Westerschelde estuary. Sediment samples were collected from three sites with different salinities, and at six time points over the year. Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA and amoA gene fragments was used to identify the AOA and AOB present. Members of the AOA were mainly belonging to the Crenarchaeota Group 1, which were found at all sites, while members of the genus Nitrosomonas, which were abundant at the brackish sites, and of the genus Nitrosospira, which were present in early spring at the marine sites, were found to be the dominant AOB. Statistical analysis indicated that salinity and temperature were the main factors controlling the diversity and distribution of both AOA and AOB. Variability in net primary production rates was also correlated with species composition of both groups, but changes in the nitrite concentration only to the distribution of the AOA. 相似文献