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111.
Gamaley I Efremova T Kirpichnikova K Kever L Komissarchik Y Polozov Y Khaitlina S 《Cell biology international》2006,30(4):319-325
The effect of N-acetylcysteine (NAC) on morphological and physiological properties of "normal" 3T3 and 3T3-SV40 fibroblasts was studied. Incubation of the cells with 10 and 20 mM NAC for 20 h resulted in a reversible increase in the intracellular level of reduced glutathione and disorganization of actin cytoskeleton. Surprisingly, upon removal of NAC, 3T3-SV40 fibroblasts demonstrated formation of well-adhered cells with structured 3T3-like stress-fibers. Neither changes in glutathione levels, nor cytoskeleton disorganization/assembly abolished resistance of 3T3 cells to invasion by the bacterium Escherichia coli A2. On the other hand, pretreatment with NAC converted bacteria-susceptible 3T3-SV40 cells into resistant ones. These results show that NAC can induce partial reversion of transformed phenotype. We suggest that this effect is due to NAC-induced modifications of cell surface proteins rather than to changes in the level of intracellular glutathione. 相似文献
112.
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114.
S S Marennikova N A Khabakhpasheva N N Mal'tseva E V Efremova 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1982,(9):99-103
The results of the preparation of peroxidase conjugates on the basis of the Fab-fragment of rabbit antivaccinal serum IgG and pure antirabbit IgG are presented. Peroxidase conjugates prepared on the basis of highly purified antibodies have been found (in vaccine virus-infected cell cultures) to ensure greater reliability of the immunoperoxidase method due to the decrease of nonspecific reactions registered by the control test system. This allows recommending peroxidase conjugates prepared on the basis of higher purified antibodies for use in diagnostic tests. 相似文献
115.
Miguel?Lacerda Penny?L?Moore Nobubelo?K?Ngandu Michael?Seaman Elin?S?Gray Ben?Murrell Mohan?Krishnamoorthy Molati?Nonyane Maphuti?Madiga Constantinos?Kurt?Wibmer Daniel?Sheward Robert?T?Bailer Hongmei?Gao Kelli?M?Greene Salim?S?Abdool?Karim John?R?Mascola Bette?TM?Korber David?C?Montefiori Lynn?Morris Carolyn?Williamson Cathal?SeoigheEmail author the CAVD-NSDP Consortium 《Virology journal》2013,10(1):347
Background
Identification of the epitopes targeted by antibodies that can neutralize diverse HIV-1 strains can provide important clues for the design of a preventative vaccine.Methods
We have developed a computational approach that can identify key amino acids within the HIV-1 envelope glycoprotein that influence sensitivity to broadly cross-neutralizing antibodies. Given a sequence alignment and neutralization titers for a panel of viruses, the method works by fitting a phylogenetic model that allows the amino acid frequencies at each site to depend on neutralization sensitivities. Sites at which viral evolution influences neutralization sensitivity were identified using Bayes factors (BFs) to compare the fit of this model to that of a null model in which sequences evolved independently of antibody sensitivity. Conformational epitopes were identified with a Metropolis algorithm that searched for a cluster of sites with large Bayes factors on the tertiary structure of the viral envelope.Results
We applied our method to ID50 neutralization data generated from seven HIV-1 subtype C serum samples with neutralization breadth that had been tested against a multi-clade panel of 225 pseudoviruses for which envelope sequences were also available. For each sample, between two and four sites were identified that were strongly associated with neutralization sensitivity (2ln(BF)?>?6), a subset of which were experimentally confirmed using site-directed mutagenesis.Conclusions
Our results provide strong support for the use of evolutionary models applied to cross-sectional viral neutralization data to identify the epitopes of serum antibodies that confer neutralization breadth.116.
117.
Anna S. Efremova Alexandra L. Zakharenko Stanislav I. Shram Irina V. Kulikova Mikhail S. Drenichev Maria V. Sukhanova 《Nucleosides, nucleotides & nucleic acids》2013,32(9):510-528
Nearly 30 synthetic nucleosides were tested with human recombinant poly(ADP-ribose) polymerase 1 as potential inhibitors of this enzyme. The most active compounds were some disaccharide analogues of thymidine: 3′-O-β-D-ribofuranosyl-5-iodo-dUrd (2d; IC50 = 45 μM), 3′-O-β-D-ribofuranosyl-2′-deoxythymidine (2e; IC50 = 38 μM), and 3′-O-β-D-ribofuranosyl-2′-deoxythymidine oxidized (4; IC50 = 25 μM). These compounds also reduced H2O2-induced synthesis of poly(ADP-ribose) in cultured human ovarian carcinoma (SKOV-3) cells in a dose-dependent manner. Furthermore, compounds 2d or 2e until a concentration of 1 mM did not affect growth of SKOV-3 cells, whereas dialdehyde compound 4, as well as thymidine, exhibited a significant cytotoxicity. 相似文献
118.
Entomopathogenic nematodes (EPN) are efficient biological pest control agents. Population genetics studies on EPN are seldom
known. Therefore, it is of interest to evaluate the significance of molecular sampling method (MSM) for accuracy, time needed, and
cost effectiveness over traditional sampling method (TSM). The study was conducted at the Mohican Hills golf course at the state
of Ohio where the EPN H. bacteriophora has been monitored for 18 years. The nematode population occupies an area of
approximately 3700 m2 with density range from 0.25-2 per gram soil. Genetic diversity of EPN was studied by molecular sampling
method (MSM) and traditional sampling method (TSM) using the mitochondrial gene pcox1. The MSM picked 88% in compared to
TSM with only 30% of sequenced cox 1 gene. All studied genetic polymorphism measures (sequence and haplotype) showed high
levels of genetic diversity of MSM over TSM. MSM minimizes the chance of mitochondrial genes amplification from non target
organisms (insect or other contaminating microorganisms). Moreover, it allows the sampling of more individuals with a reliable
and credible representative sample size. Thus, we show that MSM supersedes TSM in labour intensity, time consumption and
requirement of no special experience and efficiency. 相似文献
119.
N B Egorova V N Efremova L S Kre?nin K G Kaverina Iu N Levashov 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1987,(3):49-53
The results of the trial of an immunostimulating preparation, consisting of Klebsiella pneumoniae, Proteus, Escherichia coli and Staphylococcus antigenic complexes, on 20 patients with acute pulmonary abscess and bronchiectasis are presented. The preparation was introduced subcutaneously in 5 injections. The preparation was found to have low reactogenicity, and in the course of immunotherapy the manifestations of systemic and local reactions became considerably less pronounced. Immunotherapy produced a good curative effect, objectively manifested by a decrease in coughing and in the amount of sputum gradually changing its character. After the fourth and fifth injections the patients no longer ejected purulent sputum. Fluoroscopic examination revealed a considerable decrease in the size of the pathological focus. The preparation stimulated immunological reactions, and immunization resulted in a considerable increase in the titer of antibodies to all components of the combined preparation, as well as in an increase in the number of functionally active T-lymphocytes, in the blood of the patients. 相似文献
120.
José J. Reina-Pinto Derry Voisin Sergey Kurdyukov Andrea Faust Richard P. Haslam Louise V. Michaelson Nadia Efremova Benni Franke Lukas Schreiber Johnathan A. Napier Alexander Yephremov 《The Plant cell》2009,21(4):1252-1272
Very-long-chain fatty acids (VLCFAs) are important functional components of various lipid classes, including cuticular lipids in the higher plant epidermis and lipid-derived second messengers. Here, we report the characterization of transgenic Arabidopsis thaliana plants that epidermally express FATTY ACID ELONGATION1 (FAE1), the seed-specific β-ketoacyl-CoA synthase (KCS) catalyzing the first rate-limiting step in VLCFA biosynthesis. Misexpression of FAE1 changes the VLCFAs in different classes of lipids but surprisingly does not complement the KCS fiddlehead mutant. FAE1 misexpression plants are similar to the wild type but display an essentially glabrous phenotype, owing to the selective death of trichome cells. This cell death is accompanied by membrane damage, generation of reactive oxygen species, and callose deposition. We found that nuclei of arrested trichome cells in FAE1 misexpression plants cell-autonomously accumulate high levels of DNA damage, including double-strand breaks characteristic of lipoapoptosis. A chemical genetic screen revealed that inhibitors of KCS and phospholipase A2 (PLA2), but not inhibitors of de novo ceramide biosynthesis, rescue trichome cells from death. These results support the functional role of acyl chain length of fatty acids and PLA2 as determinants for programmed cell death, likely involving the exchange of VLCFAs between phospholipids and the acyl-CoA pool. 相似文献