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排序方式: 共有302条查询结果,搜索用时 140 毫秒
81.
Evteeva IN Kulichkova VA Mittenberg AG Volkova IV Ermolaeva IuB Teslenko LV Obukhova AD Penniiaĭnen VA Gauze LN Konstantinova IM 《Tsitologiia》2000,42(7):675-680
Our analysis detected in 26S proteasomes of human A-431 cells a strong endoribonuclease activity, degrading cytoplasmic high-molecular-mass RNA, particularly, specific mRNAs. Enzymatic nature of this activity has been confirmed, and the optimal conditions studied. This endonuclease activity of proteasomes has not been earlier observed. Proteasome involvement in the stability control of specific messenger RNA molecules is suggested, and proteasome participation in the coordinated control of various stages of gene expression is discussed. 相似文献
82.
Konstantinova IM Volkova IV Evdonin AL Ermolaeva IuB Kulichkova VA Kuz'minova AS Medvedeva ND 《Tsitologiia》2000,42(7):665-668
The subunit pattern of 20S proteasomes from rat kidney, rat liver, human A-431 cells, human K-562 cells and mouse NIH 3T3 cells were studied. Proteasomes in cells of a common tissue origin appeared to be similar, independently of the intensity of cell proliferation. Unlike, proteasomes in cells of various types of tissue specificity differed from each other. Besides, EGF was shown to induce changes in the subunit pattern of proteasomes in A-431 cells. 相似文献
83.
A number of cationic derivatives of cholesterol containing polar residues of N-methylimidazole, pyridine, N-methylmorpholine, and 4-N,N-dimethyaminopyridine were synthesized by the interaction of the corresponding heterocyclic bases with cholesterol 5-bromopentanoate followed by the treatment with methyl iodide in the case of tertiary amines. In addition, N-(4-cholesteryloxycarbonylbutyl)piperazine was obtained for the preparation of pH-sensitive liposomes. 相似文献
84.
Khripach VA Zhabinskii VN Konstantinova OV Khripach NB Antonchick AV Antonchick AP Schneider B 《Steroids》2005,70(8):551-562
A new synthesis of both epimeric forms of 26-cholestanoic acids and 26-alcohols containing a 3beta-hydroxy-Delta(5)- or a Delta(4)-3-keto-functionality in ring A is described starting from stigmasterol or (20S)-3beta-acetoxy-pregn-5-en-20-carboxylic acid. The obtained compounds are useful as standards for studies of cholic acids. Construction of the side chain was achieved by linkage of steroidal 23-iodides to sulfones prepared from (2R)- and (2S)-3-hydroxy-2-methylpropanoates. Oxidation of intermediate 26-alcohols into the corresponding carboxylic acids ensuring preservation of stereochemistry at C-25 and functional groups in the cyclic part was achieved with sodium chlorite catalyzed by TEMPO and bleach. 相似文献
85.
Effect of indole-3-acetic acid and kinetin on tuberisation parameters of different cultivars and transgenic lines of potato in vitro 总被引:1,自引:0,他引:1
G.A. Romanov; N.P. Aksenova T.N. Konstantinova S.A. Golyanovskaya J. Kossmann L. Willmitzer 《Plant Growth Regulation》2000,32(2-3):245-251
The effect of indole-3-acetic acid or kinetin on the weight and numberof microtubers formed was studied on single node cuttings of sevendifferent potato (Solanum tuberosum L.) cultivars as well astransgenic lines harbouring rolB or rolC genes undercontrol of the patatin class I (B33) promoter. Plants were cultivatedin vitro in the dark on solidified MS medium containing 1 to8% sucrose with or without phytohormones. Most of thenontransformed potato cultivars and transgenic lines responded tohormone application by an increase in tuber yield. Auxin and cytokininacted differently: IAA increased predominantly the tuber size whilekinetin increased the number of tubers. RolC transformantsdisplayed an altered response to sucrose and especially to auxin. Thedegree of phytohormone effect on tuberisation parameters depended onsucrose content of the medium and potato genotype. 相似文献
86.
It was shown on Ehrlich ascites tumor cells that for realization of the radioprotective effect of anoxia and beta-mercaptoethylamine normal content of glutathione is necessary not only at the time of irradiation but in the postirradiation period as well while glutathione content should be normal only after irradiation for realization of the radiotherapeutic effect of serotonin. 相似文献
87.
N D Konstantinova N A Zigangirova L N Kats 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1987,(6):15-18
The effects of penicillin, lithium chloride and homologous antiserum with complement on S. aureus after a single exposure to these agents and in subsequent subculturing were studied. The viability of the altered forms obtained in these experiments was evaluated by the number of colony-forming units per ml. The action of all above-mentioned agents resulted in the appearance of staphylococcal forms with the altered cell wall. The lesions in the submicroscopic organization of the cell wall, produced by the action of the above-mentioned agents, differed in the appearance of porosity and ruptures in the wall under the action of penicillin and antiserum, thinning and peeling-off of the wall under the action of lithium chloride. The damage of the cell wall is accompanied by the disorganized septal development and mitosis, and sometimes by the formation of elementary bodies in the cytoplasm. 相似文献
88.
89.
Ying Poi Liu Monique A. Vink Jan-Tinus Westerink Eva Ramirez de Arellano Pavlina Konstantinova Olivier Ter Brake Ben Berkhout 《RNA (New York, N.Y.)》2010,16(7):1328-1339
RNAi-based gene therapy is a powerful approach to treat viral infections because of its high efficiency and sequence specificity. The HIV-1-based lentiviral vector system is suitable for the delivery of RNAi inducers to HIV-1 susceptible cells due to its ability to transduce nondividing cells, including hematopoietic stem cells, and its ability for stable transgene delivery into the host cell genome. However, the presence of anti-HIV short hairpin RNA (shRNA) and microRNA (miRNA) cassettes can negatively affect the lentiviral vector titers. We show that shRNAs, which target the vector genomic RNA, strongly reduced lentiviral vector titers but inhibition of the RNAi pathway via saturation could rescue vector production. The presence of miRNAs in the vector RNA genome (sense orientation) results in a minor titer reduction due to Drosha processing. A major cause for titer reduction of miRNA vectors is due to incompatibility of the cytomegalovirus promoter with the lentiviral vector system. Replacement of this promoter with an inducible promoter resulted in an almost complete restoration of the vector titer. We also showed that antisense poly(A) signal sequences can have a dramatic effect on the vector titer. These results show that not all sequences are compatible with the lentiviral vector system and that care should be taken in the design of lentiviral vectors encoding RNAi inducers. 相似文献
90.