Publications by authors named "Grishchenko V"

Article Synopsis
  • - Species rely on environmental cues, like degree-days, to time their phenological events and exhibit varying responses based on their location and the season.
  • - The study analyzed data from 91 taxa across 472 sites in the former Soviet Union, finding that spring phenological events advance more consistently with temperature cues (cogradient variation), while autumn events are less responsive (countergradient variation).
  • - Despite some local adaptations, phenological events generally do not keep pace with environmental cues, particularly lagging further in earlier years, suggesting differing impacts of climate change on spring and autumn species responses.
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We present an extensive, large-scale, long-term and multitaxon database on phenological and climatic variation, involving 506,186 observation dates acquired in 471 localities in Russian Federation, Ukraine, Uzbekistan, Belarus and Kyrgyzstan. The data cover the period 1890-2018, with 96% of the data being from 1960 onwards. The database is rich in plants, birds and climatic events, but also includes insects, amphibians, reptiles and fungi.

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Interaction of a HAMLET-like La-OA cytotoxic complex (human α-lactalbumin-oleic acid) and its constituents with the excitable plasmalemma of giant Chara corallina cells was investigated. The voltage-clamp technique was used to study Ca and Cl transient currents in the plasmalemma of intact cells. The action of the complex and OA on the target cell membrane has a dose-dependent character.

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This study shows that toxic effect of non-modified nanoparticles of Fe3O4 in vitro depends on metabolic and morphological condition of cells, derived from fetuses and newborn rats. During the cultivation of cells with magnetic nanoparticles, the new-born rats. During the cultivation of cells with magnetic nanoparticles, the latter bind to the cell surface and penetrate into the intracellular space.

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The effect of freezing regimes and storage temperatures on protein conformation and the spectrum of cord blood serum has been investigated. Changes in the parameters of ESR spectra of spin probes in cord blood serum after slow freezing and subsequent thawing were established, indicating protein conformational changes characterized by loosening. This fact is confirmed by an earlier process, the first stage of albumin heat denaturation, as indicated by calorimetric data.

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Influence of low-molecular fraction (to 5 kDa) from cord blood (FCB) compared with "Actovegin" derived from the blood of veal calves on the content of the matrix polysaccharide components from and proteins of the cartilage connecting tissue after the mechanical trauma was investigated. It is established, that intramuscular administration of FCB essentially stimulates the accumulation of the basic components of the matrix: hexosamine, uronic acid, hyaluronic acid, chondroitinsulfate and heparin, and also the most important components of structural proteins in the cartilage regenerate of the rat knee joint.

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The specific complexes of human alpha-lactalbumin (alpha-LA) with oleic acid (OA), HAMLET and LA-OA-17 (OA-complexes), possess cytotoxic activity against tumor cells but the mechanism of their cell penetration remains unclear. To explore the molecular mechanisms underlying interaction of the OA-complexes with the cell membrane, their interactions with small unilamellar dipalmitoylphosphatidylcholine (DPPC) vesicles and electroexcitable plasma membrane of internodal native and perfused cells of the green alga Chara corallina have been studied. The fractionation (Sephadex G-200) of mixtures of the OA-complexes with the vesicles shows that OA-binding increases the affinity of alpha-LA to DPPC vesicles.

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A specific state of the human milk Ca(2+) binding protein alpha-lactalbumin (hLA) complexed with oleic acid (OA) prepared using an OA-pretreated ion-exchange column (HAMLET) triggers several cell death pathways in various tumor cells. The possibility of preparing a hLA-OA complex with structural and cytotoxic properties similar to those of the HAMLET but under solution conditions has been explored. The complex was formed by titration of hLA by OA at pH 8.

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Structural transitions in the tetrameric melittin from bee venom in 2 M KCl induced by variations of pH (from 0.7 to 12.0) and temperature (from 2 to 95 degrees C) have been studied.

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It has been shown by affinity chromatography on calmodulin-sepharose that transducin, a G protein of bovine retinal rod outer segments interacts with Ca(2+)-calmodulin. This result assumes that the main part of calmodulin in dark retinal rod outer segments is associated with transducin. It has been suggested that photoactivation of retinal rods induces changes in intracellular calmodulin concentration, which may be one of the steps involved in the light adaptation of photoreceptor.

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Polypeptides with cytostatic activity are known to be present in animal tissues during winter dormancy. A 1-10 kDa polypeptide fraction with cytostatic activity was obtained from brain tissue of hibernating ground squirrels and cold-adapted Yakut horses. The pattern of cytostatic activity of this fraction towards tumor cells is of great interest.

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The oligomerization of melittin with increasing ionic strength and protein concentration was investigated using the methods of decomposition of its tryptophan fluorescence spectra into "elementary" log-normal components. At high ionic strength (up to 2 M KCl), the emission spectra of tetrameric melittin are well described as the sum of two log-normal components, suggesting the presence of tryptophan residues in two sorts of environment with greatly differing polarity. Measurements of fluorescence spectra by iodide showed that these two spectral components possess different Stern-Volmer constants, that is, the tryptophans emitting them have different solvent accessibility, which does not correlate with the crystallographic structure of tetrameric melittin.

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Analysis of the frequency of oocytes containing premature condensed sperm chromosomes depending on clinical and embryological parameters has been carried out. It was shown that this frequency comes to 11.6% during in vitro fertilization and depends on morpho-functional characteristics of acnipo[symbol: see text] oocytes.

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Morphofunctional and cytogenetic characteristics of 34 tripronuclear human zygotes obtained during in vitro fertilization have been studied. It has been shown that 50% of them were triploid. Possible mechanisms of formation of this pathology are discussed.

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The possibility of differentiation of insulin-producing cells and neural and glial elements was demonstrated in the culture of bone marrow stromal cells. The perspectives of use of the bone marrow stromal cells in clinical medicine are considered.

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Prolonged exposure of Ca(2+)-loaded or Ca(2+)-depleted human alpha-lactalbumin to ultraviolet light (270-290 nm, 1 mW/cm(2), for 2 to 4 h) results in a 10-nm red shift of its tryptophan fluorescence spectrum. Gel chromatography of the UV-illuminated samples reveals two non-native protein forms: (1) a component with a red-shifted tryptophan fluorescence spectrum; and (2) a component with kynurenine-like fluorescent properties. The first component has from 0.

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The in vitro induced differentiation of mouse bone marrow stromal cells into nerve cells by retinoic acid and leukemia inhibitory factor has been shown, using morphological, histochemical and immunocytochemical analyses. The developed techniques allow to obtain up to 30% of neural cells in vitro. A suggestion about pluripotency of bone marrow stromal cells and possibility of their application to the cell therapy is discussed.

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We studied the effect of transplantation of fetal liver cells and postnuclear cytoplasmic fraction from human fetal soft tissues on the prooxidant-antioxidant equilibrium in the liver and blood of rats after partial hepatectomy. The preparations increased antioxidant activity and decreased the intensity of lipid peroxidation, which probably contributes to their therapeutic effects.

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Three experiments were conducted to investigate the effects of single-step and stepwise exposure to and removal of cryoprotectant, of temperature, and of a cytoskeletal relaxant on the development of germinal vesicle porcine oocytes to the M-II stage. In experiment I, noncooled cumulus-oocyte complexes (COCs) were treated using single-step/stepwise exposure to ethylene glycol (EG) and removal at 23 or 42 degrees C. Stepwise exposure to EG and dilution at 42 degrees C were found to have a positive effect on the COC developmental rate.

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A pH-induced conformational transition was found in bovine prolactin within the physiologically significant pH region from 6.5 to 8.5.

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The purpose of this study was to determine the feasibility of ultrarapid freezing of rat morulae with rapid postthaw dilution of permeable cryoprotectants in isotonic culture medium. Four experiments were carried out. Experiment 1 examined the possibility of using vitrification with postthaw dilution of permeable cryoprotectants in an isotonic solution.

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Complexes of alpha-lactalbumin (alpha-LA)1 with dimyristoylphosphatidylcholine (DMPC) or dipalmitoylphosphatidylcholine (DPPC) liposomes at pH 8 and at pH 2 have been obtained by means of gel filtration. Thermal denaturation of alpha-LA complexes of DMPC or DPPC at pH 8 was found to depend on the saturation of protein by metal cations. The intrinsic fluorescence of DMPC-alpha-LA and DPPC-alpha-LA was sensitive to two thermal transitions.

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