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241.
E. S. Kulikalova S. G. Sappo L. Ya. Urbanovich E. Yu. Markov L. V. Mironova S. V. Balakhonov 《Contemporary Problems of Ecology》2014,7(1):12-18
Vibrio cholerae eltor strains with different epidemic importance isolated from river water in the city of Vladivostok during a cholera outbreak (1999) and in the city of Irkutsk during a safe cholera period (2005) are used in the experiment. A biofilm structure consisting of a peripheral part, bundles, polysaccharide matrix, canals, and polymorphic vibrios is presented by light and luminescent microscopy. The metachromatic pink coloring of the matrix (crystal violet and toluidine blue) or fluorescent reddish orange color (acridine orange) are evidence of acid mucopolysaccharide (glucosaminoglycans) content. The biofilm of a toxigenic strain as opposed to a nontoxigenic one is formed much later, while the elements comprising its structure are more apparent. The viability of vibrio cells during the experiment (90 days) preserving the initial pathogenic potential testifies to the highly adaptable properties of the Vibrio cholerae eltor, which promotes its survival and existence in surface water reservoirs under favorable ecological conditions (optimal temperature, existence of chitin-containing substratum, etc.). 相似文献
242.
Chlamydophila pneumoniae is a common respiratory pathogen that has been shown to be associated with coronary artery disease. Recent studies have shown that one of the possible mechanisms of the atherogenicity of C. pneumoniae is overexpression of cell adhesion molecules (CAMs) in infected endothelial cells. We investigated whether exposure of C. pneumoniae-infected endothelial cells to oxidized LDL (oxLDL) leads to further upregulation of CAMs. Flow cytometry and immunoblot analysis of human aortic endothelial cells (HAECs) was performed for intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. ICAM-1 was expressed in 78.7% of C. pneumoniae-infected HAECs. The addition of oxLDL (100 microg/ml) to infected HAECs increased the proportion of ICAM-1-positive cells to 92%. VCAM-1 was only observed in 9.3% of infected HAECs, and the addition of oxLDL had no further effect on the surface expression of VCAM-1. C. pneumoniae also upregulated the surface expression of E-selectin on 52.2% of the cells, and incubation with oxLDL further increased the proportion of positive cells to 63.64%. In conclusion, C. pneumoniae upregulated the expression of the adhesion molecules ICAM-1, VCAM-1, and E-selectin on HAECs. The addition of oxLDL to the infected cells further enhanced the surface expression of ICAM-1 and E-selectin. 相似文献
243.
244.
Mitochondrial lipid pore in the mechanism of glutamate-induced calcium deregulation of brain neurons
G. D. Mironova K. N. Belosludtsev A. M. Surin A. S. Trudovishnikov N. V. Belosludtseva V. G. Pinelis I. A. Krasilnikova B. I. Khodorov 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2012,6(1):45-55
The work examines the mechanism of central nerve cell death upon stimulation of brain NMDA receptors with the stimulatory
mediator glutamate. A prolonged stimulation of neurons with glutamate is known to result in the disorder of Ca2+ homeostasis and severe mitochondrial depolarization followed by cell death. It has been shown that the overload of mitochondria
with Sr2+ leads to the release of the cation, medium alkalization, decrease of membrane potential and mitochondrial swelling, indicating
a nonspecific permeabilization of the mitochondrial membrane. The permeabilization, in our opinion, is caused by the activation
of Ca2+/Sr2+-dependent phospholipase A2 (PLA2), resulting in the formation of free palmitic and stearic acids in the mitochondrial membrane. These fatty acids bind Ca2+ with high affinity and the process of binding is accompanied by the formation of a transient lipid pore—a phenomenon demonstrated
earlier on both artificial and mitochondrial membranes. The inhibitors of PLA2 have been shown to suppress permeabilization of mitochondrial membranes. In the culture of granular cerebellum neurons, the
PLA2 inhibitors prolonged the lag of the delayed Sr2+ deregulation and membrane depolarization. On the basis of data obtained on isolated mitochondria and neurons we suppose that
the initial stages of glutamate-induced Ca2+ deregulation of neurons are underlain by the opening of lipid pores in brain mitochondria. 相似文献
245.
JOSÉ M. PADIAL JUAN C. CHAPARRO IGNACIO DE LA RIVA 《Zoological Journal of the Linnean Society》2008,152(4):737-773
We present morphological and molecular (mitochondrial DNA, mtDNA) evidence supporting the validity and monophyly of the genus Oreobates . This genus also includes members of the former Eleutherodactylus discoidalis species group plus Eleutherodactylus heterodactylus . The presence of prominent conical subarticular tubercles and prominent supernumerary tubercles associated with the axis of fingers and toes, the presence of glandular axillary pads, and the absence of vocal sacs are proposed as morphological synapomorphies. Species of this taxon form a well-supported crown clade in a phylogeny including members of the genera Craugastor and Eleutherodactylus s.l. The sister taxon to Oreobates is the Eleutherodactylus martinicensis series; Oreobates does not appear to be closely related to the Eleutherodactylus binotatus series or to members of the Eleutherodactylus dolops and Eleutherodactylus nigrovittatus species groups. The taxonomic status of all species of Oreobates is reassessed. Hylodes philippi and Hylodes verrucosus are removed from the synonymy of Oreobates quixensis . We redescribe Oreobates cruralis on the basis of the holotype and new material from Bolivia and Peru, and restrict its distribution to the humid forests of the lowlands and adjacent foothills of the Andes, from southern Peru to central Bolivia. Oreobates granulosus is rediscovered, redescribed, and resurrected, on the basis of the examination of the holotype and additional material from Peru. Phylogenetic analyses of partial 16S mtDNA are used to test the independence of lineages (species). The 14 species of Oreobates are distributed from southern Ecuador to northern Argentina. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 737–773. 相似文献
246.
A. Yu. Aksenova K. V. Volkov N. S. Rovinsky A. V. Svitin L. N. Mironova 《Molecular Biology》2006,40(5):758-763
Translation fidelity in Saccharomyces yeasts is determined by genetic and epigenetic (prion) factors. A study was made of S. cerevisiae strains containing the nonchromosomal determinant [ISP
+], described earlier. Some of its properties suggest that [ISP
+] is a prion. [ISP
+] is expressed phenotypically as an antisuppressor of two sup35 mutations and can be cured with guanidine chloride (GuHCl). It was shown that sup35 mutants containing [ISP
+] carried additional sup45 mutations. These mutations caused amino acid substitutions in different regions of translation termination factor eRF1, encoded
by SUP45. Strains bearing the sup35-25 mutation contained the sup45 mutation that caused amino acid substitution at position 400 of eRF1; strains bearing sup35-10 contained the mutation that altered eRF1 at position 75. Thus, the antisuppressor phenotype of the [ISP
+] strains proved to depend on the interaction of sup35 and sup45 mutations, as well as on the GuHCl-curable epigenetic determinant.
Published in Russian in Molekulyarnaya Biologiya, 2006, Vol. 40, No. 5, pp. 844–849.
The article was translated by the authors. 相似文献
247.
S. E. Moskalenko G. A. Zhouravleva M. Y. Soom S. V. Chabelskaya K. V. Volkov O. M. Zemlyanko M. Philippe L. N. Mironova S. G. Inge-Vechtomov 《Russian Journal of Genetics》2004,40(5):478-484
Collection of missense mutations in the SUP45 gene of Saccharomyces cerevisiae encoding translation termination factor eRF1 has been obtained by different approaches. It has been shown that most of isolated mutations cause amino acid substitutions in the N-terminal part of eRF1 and do not decrease the eRF1 amount. Most of mutations studied do not abolish eRF1–eRF3 interaction. The role of the N-terminal part of eRF1 in stop codon recognition is discussed. 相似文献
248.
P. V. Avdonin A. A. Tsitrina G. Y. Mironova P. P. Avdonin I. L. Zharkikh A. D. Nadeev N. V. Goncharov 《Biology Bulletin》2017,44(5):531-537
The aim of our research was to study the influence of hydrogen peroxide on the exocytosis of von Willebrand factor (vWF) in human umbilical vein endothelial cells (HUVEC). We have found that H2O2 at a non-toxic concentration (100 μM) increases the amount of vWF secreted by HUVEC by 43 ± 14% over control (p < 0.03) and elevates total exposition of vWF on cell surface by 89 ± 5% (p < 0.01). Analysis of immunofluorescent images of HUVEC with CellProfiler program revealed that the average number of antigen positive structures on the single cell surface increases from 11.4 ± 0.16 in control up to 17.5 ± 0.21 after incubation with H2O2 (p < 0.01). vWF is exposed on the cell surface as dots with the average sizes around 1–3 μm. H2O2 causes an increase in the number of these dots and the appearence of the strings of vWF which are absent in control HUVEC. It is suggested that H2O2 may serve as a messenger which stimulates vWF exocytosis. 相似文献
249.
Kirill V Volkov Anna Yu Aksenova Malle J Soom Kirill V Osipov Anton V Svitin Cornelia Kurischko Irina S Shkundina Michael D Ter-Avanesyan Sergey G Inge-Vechtomov Ludmila N Mironova 《Genetics》2002,160(1):25-36
Two cytoplasmically inherited determinants related by their manifestation to the control of translation accuracy were previously described in yeast. Cells carrying one of them, [PSI(+)], display a nonsense suppressor phenotype and contain a prion form of the Sup35 protein. Another element, [PIN(+)], determines the probability of de novo generation of [PSI(+)] and results from a prion form of several proteins, which can be functionally unrelated to Sup35p. Here we describe a novel nonchromosomal determinant related to the SUP35 gene. This determinant, designated [ISP(+)], was identified as an antisuppressor of certain sup35 mutations. We observed its loss upon growth on guanidine hydrochloride and subsequent spontaneous reappearance with high frequency. The reversible curability of [ISP(+)] resembles the behavior of yeast prions. However, in contrast to known prions, [ISP(+)] does not depend on the chaperone protein Hsp104. Though manifestation of both [ISP(+)] and [PSI(+)] is related to the SUP35 gene, the maintenance of [ISP(+)] does not depend on the prionogenic N-terminal domain of Sup35p and Sup35p is not aggregated in [ISP(+)] cells, thus ruling out the possibility that [ISP(+)] is a specific form of [PSI(+)]. We hypothesize that [ISP(+)] is a novel prion involved in the control of translation accuracy in yeast. 相似文献
250.
Alexey Agafonov Konstantin Belosludtsev Odile Gateau-Roesch Galina D. Mironova 《生物化学与生物物理学报:生物膜》2003,1609(2):153-160
Formation of palmitic acid/Ca2+ (PA/Ca2+) complexes was suggested to play a key role in the non-classical permeability transition in mitochondria (NCPT), which seems to be involved in the PA-induced apoptosis of cardiomyocytes. Our previous studies of complexation of free fatty acids (FFA) with Ca2+ showed that long-chain (C:16-C:22) saturated FFA had an affinity to Ca2+, which was much higher than that of other FFA and lipids. The formation of FFA/Ca2+ complexes in the black-lipid membrane (BLM) was demonstrated to induce a nonspecific ion permeability of the membrane. In the present work, we have found that binding of Ca2+ to PA incorporated into the membrane of sulforhodamine B (SRB)-loaded liposomes results in an instant release of a part of SRB, with the quantity of SRB released depending on the concentration of PA and Ca2+. The pH-optimum of this phenomenon, similar to that of PA/Ca2+ complexation, is in the alkaline range. The same picture of SRB release has been revealed for stearic, but not for linoleic acid. Along with Ca2+, some other bivalent cations (Ba2+, Sr2+, Mn2+, Ni2+, Co2+) also induce SRB release upon binding to PA-containing liposomes, while Mg2+ turns out to be relatively ineffective. As revealed by fluorescence correlation spectroscopy, the apparent size of liposomes does not alter after the addition of PA, Ca2+ or their combination. So it has been supposed that the cause of SRB release from liposomes is the formation of lipid pores. The effect of FFA/Ca2+-induced permeabilization of liposomal membranes has several analogies with NCPT, suggesting that both these phenomena are of similar nature. 相似文献