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111.
Oxidoreductase activity of peat soils as an indicator of the degree of biochemical transformation of drained and forested bogs in West Siberia 总被引:1,自引:0,他引:1
Multivariate analysis unambiguously demonstrated the differentiation of oxidoreductase activity (catalase, peroxidase, and dehydrogenase) in peat soils after a 20–25-year period of bog drainage and afforestation. The enzyme activity depended on the drainage depth. A statistical model has been developed to predict the degree of humification of peat organic matter from peroxidase activity and moisture of drained soils. Soil peroxidase activity can be an important indicator of the degree of biochemical transformation of drained and forested bogs. 相似文献
112.
V L Sharygin M A Avakian M K Pulatova O I Efremova Iu I Mitrokhin 《Radiobiologiia》1986,26(2):189-194
It has been shown, that the single injection of gamma-hydroxybutyric acid (GHBA) (100 mg/kg) to mice 30 min before irradiation (6 Gy) prevents whole-body irradiation-induced inhibition of DNA at early post-irradiation period. GHBA stimulates the biosynthesis of macromolecules at 1-2 days after irradiation. GHBA also prevents the increase in the degree of reduction of the mitochondrial and microsomal electron transport chains at early post-irradiation time (up to 2 h.), that takes place only under irradiation. It means, that GHBA inhibits the production of O2 radicals, which induce lipid peroxidation processes at post-irradiation period. 相似文献
113.
A. S. Efremova V. P. Zinchenko 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2008,2(4):372-379
Previous studies have shown that micromolar concentrations of calmodulin inhibitor calmidazolium induce fast activation of nonselective Ca2+ channels in plasma membranes of Ehrlich ascites carcinoma cells (Zinchenko, V.P., Kasymov, V.A., Li, V.V., and Kaimachnikov, N.P., Biofizika (Rus.), 2005, vol. 50 (6), pp. 1055–1069). In order to detect this type of Ca2+ channels in other cells and to establish common regulatory mechanisms, we studied calmidazolium effects on rat thymocytes. It was found that calmidazolium induces biphasic increases in Ca2+ content in cytosol of rat thymocytes due to Ca2+ entry from external medium and reflects the activity of nonselective Ca2+ channels permeable for Mn2+ and Ni2+ ions. The rate and the amplitude of the fast phase are decreased, while those of the slow phase are increased in the presence of specific inhibitors of Ca2+-independent phospholipase A2 (bromoenol lactone and palmitoyl trifluoromethyl ketone). The rate and the amplitude of the fast phase are also inhibited by arachidonic acid and the lipoxygenase inhibitor nordihydroguaiaretic acid, while the Ca2+-dependent phospholipase A2 inhibitor bromophenacyl bromide, the cyclooxygenase inhibitor indomethacin, the specific store-operated Ca2+ channel inhibitor gadolinium and the phospholipase C inhibitor U73122 have no such effect. The rate of the fast phase only slightly depends on temperature, while that of the slow phase shows a strong temperature dependence and increases with a rise in temperatures (Q 10 = 2). The amplitude of the fast phase of the Ca2+ signal increases with a decrease of temperatures due to prolongation of the maximum activity of the Ca2+ channel. The data obtained suggest that iPLA2 is an intermediate link in the activation of calmidazolium-induced nonselective Ca2+ channels. The iPLA2 products lysophospholipids and arachidonic acid activate and inhibit Ca2+ channels, respectively. The fact that these compounds manifest different affinities for Ca2+ channels shed additional light on the mechanisms of biphasic Ca2+ elevation in thymus cell cytosol and prolongation of the active state of Ca2+ channels at low temperatures. 相似文献
114.
Valeria Itskovich Andrey Gontcharov Yoshiki Masuda Tsutomu Nohno Sergey Belikov Sofia Efremova Martin Meixner Dorte Janussen 《Journal of molecular evolution》2008,67(6):608-620
Freshwater sponges include six extant families which belong to the suborder Spongillina (Porifera). The taxonomy of freshwater
sponges is problematic and their phylogeny and evolution are not well understood. Sequences of the ribosomal internal transcribed
spacers (ITS1 and ITS2) of 11 species from the family Lubomirskiidae, 13 species from the family Spongillidae, and 1 species
from the family Potamolepidae were obtained to study the phylogenetic relationships between endemic and cosmopolitan freshwater
sponges and the evolution of sponges in Lake Baikal. The present study is the first one where ITS1 sequences were successfully
aligned using verified secondary structure models and, in combination with ITS2, used to infer relationships between the freshwater
sponges. Phylogenetic trees inferred using maximum likelihood, neighbor-joining, and parsimony methods and Bayesian inference
revealed that the endemic family Lubomirskiidae was monophyletic. Our results do not support the monophyly of Spongillidae
because Lubomirskiidae formed a robust clade with E. muelleri, and Trochospongilla latouchiana formed a robust clade with the outgroup Echinospongilla brichardi (Potamolepidae). Within the cosmopolitan family Spongillidae the genera Radiospongilla and Eunapius were found to be monophyletic, while Ephydatia
muelleri was basal to the family Lubomirskiidae. The genetic distances between Lubomirskiidae species being much lower than those
between Spongillidae species are indicative of their relatively recent radiation from a common ancestor. These results indicated
that rDNA spacers sequences can be useful in the study of phylogenetic relationships of and the identification of species
of freshwater sponges. 相似文献
115.
The paper reports a light and electron microscopy study of the ultrastructure and oogenesis of germ-cell determinants in freshwater sponges Eunapius fragilis and Swartschewskia papyracea. For the first time, germinal granules surrounded by mitochondria, the ultrastructural signature of germinal plasma in a number of metazoan organisms, has been described in Porifera. Structural changes in germ determinants in the course of oogenesis have been described, and participation of mitochondria in the formation of the central component of germ cell determinants has been suggested. 相似文献
116.
A.?A.?Spasov Yu.?V.?Popov V.?S.?Lobasenko T.?K.?Korchagina P.?M.?Vassiliev V.?A.?Kuznetsova A.?A.?BrigadirovaEmail author A.?I.?Rashchenko D.?A.?Babkov A.?N.?Kochetkov A.?I.?Kovaleva O.?S.?Efremova 《Russian Journal of Bioorganic Chemistry》2017,43(2):163-169
New esters of N-benzoyl-3-phenoxyphenylcarboxamide acid and N-benzoyl-N′-4-bromophenyl-3-phenoxybenzamidine were synthesized. Some of the synthesized compounds were shown to inhibit the activity of dipeptidyl peptidase-4 and nonenzymatic glycosylation of proteins and manifested antiplatelet and antioxidant properties. The compounds tested did not display the antagonistic effect toward angiotensin II type 1 receptor, did not influence the activity of glycogen phosphorylase and had very little ability to break cross-links of the glycated proteins. The derivatives with the biological activity of two types were found, which can serve as basic molecules in the search for new drug products. 相似文献
117.
Genetic analysis of anthocyanin of the anthers and culm pigmentation in common wheat 总被引:1,自引:0,他引:1
Anthocyanin pigmentation of various organs develops during plant ontogeny in response to adverse and damaging abiotic and biotic stressors (environmental factors). Using the monosome method, the genes responsible for anther and culm anthocyanin pigmentation (Pan1 and Pc2, respectively) were localized to 7D chromosome in introgressive lines from crosses between common wheat Triticum aestivum L. and the species Triticum timopheevii Zhuk. Genetic analysis of ten common wheat genotypes using testers carrying genes Pan1, Pn1, and Pn2 showed that these genotypes contained Pan1 and Pn2 genes. Visual examination of plants from 70 and 76 varieties of respectively winter and spring common wheat revealed anthocyanin pigmentation of anthers and culms in 36 varieties. Pan1 and Pn2 genes were presumably introduced into common wheat from Aegilops tauschii (Fig.) Tzvel., a donor of the D genome. 相似文献
118.
Effect of antioxidants on actin cytoskeleton in 3T3 fibroblasts and 3T3 fibroblasts transformed with SV40 virus (3T3-SV40 cells) was studied. Antioxidants used were as follows: N-acetyl-L-cysteine (NAC), (-)-2-oxo-4-thiazolidine-carboxylic acid (OTZ), and glutathione in the reduced form (GSH). Both NAC and OTZ are precursors of GSH in the cell, but, in contrast to NAC, OTZ reduces inside the cell forming L-cysteine. The presence of NAC (5-20 mM) in the culture medium of both cell types resulted in loosening of monolayer, fragmentation of stress fibers, and the appearance of amorphous actin structures. As 3T3-SV40 cells contain less actin stress fibers than 3T3 cells, the NAC-induced rearrangements of actin cytoskeleton were stronger in these cells than in 3T3 cells. In contrast to NAC, OTZ (10-20 mM) did not destroy monolayer and did not induce any visible disappearance of stress fibers either in 3T3 or 3T3-SV40 cells. However, in the presence of OTZ, amorphous actin-containing structures were observed in 3T3-SV40 cells. The effect of glutathione on both cell types was similar to that of NAC. The time required for GSH-induced alterations of actin cytoskeleton (about 5 h) was consistent with the increase in the intracellular level of reactive oxygen species (4 h after addition of GSH to the culture medium). Upon removal of the antioxidants from the medium, actin filament structures were reconstructed. However, within 24 h after withdrawal of NAC or GSH, only a partial reconstruction of stress fibers was observed in 3T3 cells. On the contrary, 3T3-SV40 cells demonstrated formation of well-structured actin fibers similar to normal fibroblasts. These results suggest that GSH can act as a pro-oxidant in the absence of oxidative stress. 相似文献
119.
Molecular and genetic interactions between STYLOSA and GRAMINIFOLIA in the control of Antirrhinum vegetative and reproductive development 总被引:3,自引:0,他引:3
Navarro C Efremova N Golz JF Rubiera R Kuckenberg M Castillo R Tietz O Saedler H Schwarz-Sommer Z 《Development (Cambridge, England)》2004,131(15):3649-3659
120.