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51.
E. S. Meteleva Yu. S. Chistyachenko L. P. Suntsova M. A. Tsyganov G. B. Vishnivetskaya D. F. Avgustinovich M. V. Khvostov N. E. Polyakov T. G. Tolstikova V. A. Mordvinov A. V. Dushkin N. Z. Lyakhov 《Doklady. Biochemistry and biophysics》2018,481(1):228-231
The mechanochemical preparation of solid compositions of praziquantel with plant saponin (glycyrrhizic acid disodium salt) is described. The study of a number of physicochemical parameters showed that dissolving solid compositions in water is accompanied by the inclusion of praziquantel molecules into micelles, which are formed in the solution of the glycyrrhizic acid disodium salt. Using the opisthorchiasis model caused by Opisthorchis felineus, we found a 4- to 11-fold increase in the anthelmintic activity of praziquantel in the composition as compared to the official praziquantel. According to the pharmacokinetic data, the use of the composition increased the bioavailability of praziquantel 3 times. 相似文献
52.
Roessler A Hinghofer-Szalkay H Noskov V Laszlo Z Polyakov VV 《Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology》1997,4(2):P101-P102
We performed an experiment within the project "RLF" (Russian long-term flight) on a cosmonaut onboard the space station MIR. For creating an analogue to orthostatic stress, we used lower body negative pressure (LBNP) as stimulus. Decrease in central and peripheral baroreceptor load by LBNP can be used as a cardiovascular countermeasure in cosmonauts or for inducing endocrine responses. Altered steady-state plasma concentration values of volume sensitive hormones have been observed inflight as well as postflight. Within this project we measured plasma ANP and cGMP as second messenger. Changes in plasma cGMP concentration are generally considered to be a good indicator of those in ANP activity. However, in our experiments depression of cGMP during space flight was more impressive than ANP decline. We are not aware of previous measurements of plasma cGMP under these conditions, and believe to be the first to report complete suppression of plasma cGMP during long-term stay in space. 相似文献
53.
A study of ultrathin sections of normal Chinese hamster cells and cells treated with decreasing concentrations of bivalent cations (Ca2+ and Mg2+) in situ revealed several discrete levels of compaction of DNA-nucleoprotein (DNP) fibrils in mitotic chromosomes and the chromatin of interphase nuclei. At concentrations ranging from 3 mM CaCl2 and 1 mM MgCl2 to ten times less, the chromosomes are found to contain fibrous elements (chromonemata) about 100 nm in diameter. As Ca2+ concentration is gradually decreased to 0.2–0.1 mM, the chromosomes decondense into a number of discrete chromatin structures, the chromomeres. As decondensation proceeds, these chromomeres acquire a rosettelike structure with DNP fibrils radiating from an electron-dense core. Upon complete decondensation of chromosomes, individual chromomeres persist only in the centromeric regions. The following levels of DNP compaction in mitotic chromosomes are suggested: a 10-nm nucleosomal fibril, a 25-nm nucleomeric fibril, and the chromonema, a fibrous structure, about 100 nm in diameter, composed of chromomeres. Interphase nuclei also contain structures which are morphologically similar to the chromomeres of mitotic chromosomes. 相似文献
54.
Low Diversity of T Haplotypes in the Eastern Form of the House Mouse, Mus Musculus L 总被引:2,自引:1,他引:1 下载免费PDF全文
In previous studies, 13 different recessive embryonic lethal genes have been associated with t haplotypes in the wild mice of the species Mus domesticus. In this communication we have analyzed five populations of Mus musculus for the presence and identity of t haplotypes. The populations occupy geographically distant regions in the Soviet Union: Altai Mountains, western and eastern Siberia, Azerbaijan and Turkmenistan. No t haplotypes were found in mice from eastern Siberia. In the remaining four populations, t haplotypes occurred with frequencies ranging from 0.07 to 0.21. All the t haplotypes extracted from these populations and analyzed by the genetic complementation test were shown to carry the same lethal gene tcl-w73. In one population (that of western Siberia), another lethal gene (tcl-w5) was found to be present on the same chromosome as tcl-w73. This situation is in striking contrast to that found in the populations of the western form of the house mouse, M. domesticus. In the latter species, tcl-w73 has not been found at all and the different populations are characterized by the presence of several different lethal genes. The low diversity of t haplotypes in M. musculus is consistent with lower genetic variability of other traits and indicates a different origin and speciation mode compared to M. domesticus. Serological typing for H-2 antigenic determinants suggests that most, if not all, of the newly described t haplotypes might have arisen by recombination of tw73 from M. musculus with t haplotypes from M. domesticus either in the hybrid zone between the two species or in regions where the two species mixed accidentally. 相似文献
55.
Comparison of active sites of some microbial ribonucleases: structural basis for guanylic specificity 总被引:3,自引:0,他引:3
J Sevcik R G Sanishvili A G Pavlovsky K M Polyakov 《Trends in biochemical sciences》1990,15(4):158-162
Crystallographic studies of enzymes complexed with suitable ligands are an important tool to aid our understanding of biological catalysis. To this goal, a contribution is made by analysing structures of complexes formed by three guanyl-specific ribonucleases with guanosine 3'-monophosphate. 相似文献
56.
The effect of charged micron-size dust grains (microparticles) on the electric parameters of the positive column of a low-pressure dc glow discharge in neon has been studied experimentally and numerically. Numerical analysis is carried out in the diffusion-drift approximation with allowance for the interaction of dust grains with metastable neon atoms. In a discharge with a dust grain cloud, the longitudinal electric field increases. As the number density of dust grains in an axisymmetric cylindrical dust cloud rises, the growth of the electric field saturates. It is shown that the contribution of metastable atoms to ionization is higher in a discharge with dust grains, in spite of the quenching of metastable atoms on dust grains. The processes of charging of dust grains and the dust cloud are considered. As the number density of dust grains rises, their charge decreases, while the space charge of the dust cloud increases. The results obtained can be used in plasma technologies involving microparticles. 相似文献
57.
M. A. Gruzdeva K. V. Kusishchin E. D. Pavlov A. G. Bush N. V. Belova M. P. Polyakov A. M. Malyutina D. S. Pavlova 《Journal of Ichthyology》2017,57(5):688-705
Growth, age composition, gonad maturity and patterns of life history strategy adoption in the population of Dolly Varden from the Kol River (West Kamchatka) are studied. Major factors controlling differentiation of juveniles and trajectories of ontogenetic developments, growth rate and gametogenesis in generations in particular years. The differentiation in a generation into anadromous and resident groupings is completed mainly at the age of 4 years. The process of formation of resident and migratory life history strategy in Dolly Varden is epigenetic. Bifurcation in the life of one specimen is observed once in life, and that in a generation is observed four times: at the first, the second, the third, or the fourth year. The life cycle of females from the Kol River is invariant until they reach the age of 1 year, and that in males is during the 4 years of the freshwater phase. In Kamchatka, all spawners, including precocious males, may reproduce several times during life. 相似文献
58.
Polyakov VY Zatsepina OV Kireev II Prusov AN Fais DI Sheval EV Koblyakova YV Golyshev SA Chentsov YS 《Biochemistry. Biokhimii?a》2006,71(1):1-9
In the present review the structural role of noncoding DNA, mechanisms of differential staining of mitotic chromosomes, and structural organization of different levels of DNA compactization are discussed. A structural-functional model of the mitotic chromosome is proposed based on the principle of discreteness of structural levels of DNA compactization. 相似文献
59.
Tikhonova TV Slutsky A Antipov AN Boyko KM Polyakov KM Sorokin DY Zvyagilskaya RA Popov VO 《Biochimica et biophysica acta》2006,1764(4):715-723
A highly active cytochrome c nitrite reductase from the haloalkaliphilic sulfur-oxidizing non-ammonifying bacterium Tv. nitratireducens strain ALEN 2 (TvNiR) was isolated and purified to apparent electrophoretic homogeneity. The enzyme catalyzes reductive conversion of nitrite and hydroxylamine to ammonia without release of any intermediates, as well as reduction of sulfite to sulfide. TvNiR also possesses peroxidase activity. In solution TvNiR exists as a stable hexamer with molecular mass of about 360kDa. Each TvNiR subunit with molecular mass of 64kDa contains, as defined from spectral properties and sequence analysis, eight c-type haems. Seven of them are coordinated by the characteristic CXXCH motifs for haem c binding, while one is bonded by the unique CXXCK motif. So far, this motif coordinating the catalytic haem was found only in bacterial cytochrome c nitrite reductases (ccNiRs). All the residues essential for catalysis in the known ccNiRs were also identified in TvNiR. However, TvNiR is only distantly related to known bacterial ammonifying dissimilatory ccNiRs, sharing no more than 20% homology. 相似文献
60.
Barry Malmanger Maureen Lawler Shannon Coulombe Rochelle Murray Staci Cooper Yekaterina Polyakov John Belknap Robert Hitzemann 《Mammalian genome》2006,17(12):1193-1204
We have completed whole-genome scans for quantitative trait loci (QTLs) associated with acute ethanol-induced activation in
the six F2 intercrosses that can be formed from the C57BL/6J (B6), DBA/2J (D2) , BALB/cJ (C), and LP/J (LP) inbred strains. The goal
was to test the hypothesis that given the relatively simple structure of the laboratory mouse genome, the same QTLs will be
detected in multiple crosses which in turn will provide support for the strategy of multiple-cross mapping (MCM). QTLs with
LOD scores greater than 4 were detected on Chrs 1, 2, 3, 8, 9, 13, 14, and 16. Only for the QTL on distal Chr 1 was there
convincing evidence that the same or at least a very similar QTL was detected in multiple crosses. We also mapped the Chr
2 QTL directly in heterogeneous stock (HS) animals derived from the four inbred strains. At G19 the QTL was mapped to an approximately 3-Mbp interval and this interval was associated with a haplotype block with a largely
biallelic structure: B6-L:C-D2. We conclude that mapping in HS animals not only provides significantly greater QTL resolution,
at least in some cases it provides significantly more information about the QTL haplotype structure. 相似文献