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Biomedical subjects

L I Ostapchenko

Publications and source records attributed to L I Ostapchenko.

At least 19 recordsLinked to original sources
PubMed2004

Clinostating effects on Apogee wheat resistance to wheat streak mosaic virus.

The effects of vertical and horizontal clinostating with container velocity 2 rpm and platform velocity 1 rpm on Apogee wheat resistance to wheat streak mosaic virus (WSMV) were studied. For the first time the yield of grain was obtained from both, healthy and the WSMV-infected wheat plants under conditions of simulated microgravity (clinorotation) which is accounted for by the inclusion of various mechanisms in the process of plant adaptation to the factors of stresses. For the first time the stages of viral infection development were elucidated under the conditions of prolonged clinostating and the presence of the WSMV was detected in wheat plants on the 18th day after inoculation employing the method of polymerase chain reaction (PCR). In the test variant with vertical clinostating (R=1,0) the least favorable conditions for viral reproduction were identified. In the same variant the increases of the total nitrogen content in the ears were observed which may be an evidence of interferon-like protein synthesis in plant similar to the interferon system functioning in animals.

Biomass↗
PubMed1989

[Ca2+-phospholipid-dependent phosphorylation of cytosol and membrane proteins of the brain in light craniocerebral trauma].

Immediately after light craniocerebral trauma (LCCT) the system of Ca2+, phospholipid-dependent phosphorylation of cytosol and microsomes of diencephalic-brainstem regions was impaired. The system of regulation of activity of C-kinase by phosphatidylserine was upset in the course of posttraumatic period and was different for cytosol and hemispheres. The increase in phosphorylation upon addition of exogenic C-kinase to incubation medium was evident only with stimulation of endogenic phosphorylation by phosphatidylserine. The decrease in Ca2+, phospholipid-dependent phosphorylation was characteristic of all fractions studied 1 day after trauma. After 14 days, the enzyme activity did not return to baseline. The authors suggest that C-kinase participates in trigger mechanisms of posttraumatic disease.

Animals↗
PubMedDate not supplied

[The use of nontraditional approaches to the analysis of the effects of radiation on the system of protein phosphorylation in spleen lymphocytes].

Postradiation disturbances in functioning of Ca(2+)- and cyclic nucleotide-dependent protein kinase systems are established. Kinetic index of different protein kinases of spleen lymphocytes under irradiation with doses of 0.5 and 1 Gy are analysed using return-cards-construction and Lyapunov's-coefficient-determination methods. It is shown that determined disturbances can be considered as a part of general unspecific adaptational reaction of lymphocytes to irradiation.

Animals↗
PubMedDate not supplied

Protein kinases, regulated by calcium and calmodulin: their structure, regulation and cellular functions.

In this review we summarize and generalize the recent data on structure, regulation and physiological role of calcium/calmodulin-dependent protein kinases, or CaM kinases. CaM kinases are the family of structurally homologous enzymes, involved into a variety of Ca(2+)-induced cellular reactions through phosphorylation of target proteins. In recent years the quantity of these enzymes has exceeded twenty, mainly due to identification of new isozymic forms of already known CaM kinases. Using crystal structure analysis data, some researchers constructed molecular models of regulation and functioning of CaM kinases. Many reports of recent years are devoted to investigation of functions of CaM kinase isozymes and their role in various cellular processes.

Amino Acid Sequence↗
PubMedDate not supplied

[Receptor protein tyrosine kinase in splenic lymphocytes. Features of isolation and purification properties].

By means of an immune affinity chromatography we have obtained some receptor tyrosine protein kinase preparations from the spleen lymphocytes membrane in control and in 12 hours after rat X-ray irradiation in the doses of 0.5 and 1 Gy. An inhibitory analysis and estimation of essential catalytic properties of this enzyme have been performed. As a result of the researches performed we have suggested that EGF-R tyrosine protein kinases are involved in radiation-induced response of immune competent spleen cells and mediate the effects of EGF signal transduction in these cells in 12 hours after irradiation in the dose of 1 Gy.

Animals↗
PubMedDate not supplied

[Structure and functional features of enzymes from the Ca2+-phospholipid-dependent protein kinase family].

Present day scientific data about the Ca(2+)-phospholipid-dependent protein kinases structure and molecular mechanisms of their activity are summarized and analyzed in this review. Ca(2+)-phospholipid-dependent protein kinases family is well known to include a whole series of enzymes which are homologous by their structure. They play an important role in cell differentiation, growth and proliferation as well as signal transduction through the cytoplasmic membrane. They also take part in cell response realization by phosphorylation of target proteins. Now application of modern biochemical and biophysical methods provided for possibility of the clarification of these enzymes structure features. The great lot of experimental data about the molecular mechanisms of Ca(2+)-phospholipid-dependent protein kinases activity regulation by phosphatydyle serine, phorbol ethers, saturated and unsaturated fatty acids, calcium iones, autophosphorylation and holoferment phosphorylation by other kinases was obtained. As a model of Ca(2+)-phospholipide-dependent protein kinases regulation was their development on the base of the scientific data about this problem.

Calcium↗
PubMedDate not supplied

[Effect of the substances "Ammivit" and "cerloplasmin" on lipid peroxidation products level and of antioxidant system indicators under irradiation].

It has been shown, that the total X-ray irradiation in the dozes of 0.5 and 1 Gy influences on the content of lipid peroxidation products and enzymatic activity of antioxidant system in rat spleen and thymus cells. The influence of preparations "AMMIVIT" and "Ceruloplasmin" on these processes is investigated also. So, the animals feeding by the vitamin concentrate "AMMIVIT" have lead to increase of MDA level (a final product of lipid peroxidation) and the overactivity of some antioxidant enzymes in rat spleen and thymus cells. Injection of the preparation "Ceruloplasmin" to experimental animals up 1 hour before the irradiation has normalized LPO intensity and activity of AO enzymes.

Animals↗
PubMedDate not supplied

[Activity of dsRNA-dependent protein kinase in rat lymphoid cells under the effect of X-ray irradiation].

The activity of dsRNA-dependent protein kinase, which is the key enzyme of the interferon signal system, was studied in the rat spleen and thymus lymphocytes under the influence of X-ray irradiation at 0.5 and 1 Gy doses and interferon inducers administration. An increase of the enzyme activity was established in the presence of FGA, concanavaline A, poly(I).poly(C) in vitro. The effect is intensified under the irradiation by 0.5 Gy dose. The protein kinase activity in lymphocytes is amplified in proportion to poly(I).poly(C) concentration, that was most pronounced in the irradiated animals. The comparative analysis of the action of interferon inducers on the dsRNA-dependent protein kinase activity was carried out. Two biological systems were used: in vivo (when the preparations were injected to the experimental animals) and in vivo (under the preincubation of isolated lymphocytes with the inducers). It was shown that the combined action of radiation and interferon inducers causes the stimulation of dsRNA-dependent protein kinase activity.

2',5'-Oligoadenylate Synthetase↗
PubMedDate not supplied

[Interferon-induced 2',5'-oligoadenylate system: key components and biological functions].

The current data about the 2',5'-oligoadenylate system is reviewed. Its role in interferon signaling and cell metabolism regulation is discussed. The interferon system is known to be characterized by a wide range of biological functions such as antiviral defense, control of cell growth and differentiation, oncogenic stability, apoptosis, immune activation, etc. The biological role of interferon that is the multifunctional cytokine is discussed more in detail. The structure of main components of interferon signal transduction cascade (2',5'-oligoadenylate, 2',5'-oligoadenylate-synthetase and ribonuclease L) is reviewed. The interferon-induced 2',5'-oligoadenylate system is considered as the component of common regulatory system coordinating cell metabolism.

2',5'-Oligoadenylate Synthetase↗
PubMedDate not supplied

[Role of the protein tyrosine phosphatase CD45 in signal transduction of hematopoietic cells].

This review deals with the analysis of modern literature about structure, catalytical activity, biological role and practical usage of protein tyrosine phosphatase CD45, which is widely distributed in the membranes of hematopoietic cells. The enzyme location makes it a highly sensitive test for estimation of development of such pathological states as immunological and neoplastic diseases, malignant tumors and transplantation responses of tissue tearing away. Unequal enzyme isoforms expressed in various leucocyte cell lines at different stages of development and differentiation are typical of those species. The existence of multiple isoforms is not used only to determine various cell lines, but also causes existence of variable adhesion requirements resulting in local restriction of activity and changes in the substrate binding. There is no doubt that definition of substrate molecules, influence of proteintyrosinephosphatase CD45 translocation and regulation of its activity by other ligands are important questions. Solution of these problems will be useful for searching the correctional means of dysfunctions of the tissues, enriched with protein tyrosine phosphatase CD45.

Animals↗
PubMedDate not supplied

[Participation of cyclic nucleotides and phospholipidis in signal transduction of histamin receptor H3 of the gastric mucosa parietal cells in rats with experimental ulcer].

The goal of the work was to evaluate plasma membrane phospholipid composition in rat gastric parietal cells under the histamine H3 receptor activation. The content of cyclic nucleotides was also studied. It was shown that H3-receptor agonist (R)-alpha-methylhistamine increases the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) level and decreases the phoshatidylinositole level in plasma membrane of rat gastric parietal cells and leads to attenuation of the cGMP production and enhancement of the cAMP production under the experimental stress--the induced stomach ulcer formation. The histamine H3-receptor antagonist, thioperamide, insignificantly increases the PC and PE level and increases the phoshatidylinositole level in the plasma membrane of rat gastric parietal cells and leads to cAMP production attenuation, and cGMP contents decreases in the above-stated cells. Thus it was shown that histamine H3 receptor activation causes different effects on polyphosphoinositide and adenylatcyclase cascades in parietal cells under stomach ulcer conditions.

Animals↗
PubMedDate not supplied

[The content of cyclic nucleotides, free cytoplasmic Ca2+ and malondialdehyde in the splenic lymphocytes and thymocytes of rats under the action of moderate doses of radiation].

It has been shown that the malonic dialdehyde (MDA) content in spleen lymphocytes of rats increases after whole-body X irradiation with a dose of 0.5 Gy to reach the maximum level in 24 h. Simultaneously, the concentration of cGMP and free cytosol Ca2+ increases. With a dose of 1 Gy MDA content of cells increases 6 h following irradiation. The maximum drop of the release of viable lymphocytes from the spleen and thymus, observed 24 h and 3 days after irradiation respectively, coincides with the appearance of the second peak of the MDA content. The level of cGMP remains decreased throughout the period of about 6 days. The onset of lymphocyte repopulation in the spleen on day 6 coincides with the decrease in the MDA level and increase in the cytosol Ca2+ concentration.

Animals↗
PubMedDate not supplied

[Binding of cyclic adenosine monophosphate by cAMP-dependent protein kinases of the brain during an early period of acute radiation exposure].

Binding of 3H-cAMP to cAMP-dependent protein kinases isolated from cytosol and Triton X-100 solubilized synaptic membranes of gray substance cells of rat brain was studied in the control and X-irradiated (0.21 Cl/kg) rats (60 min after whole-body irradiation). It was shown that at the early stages of radiation affection the interaction of the studied enzyme forms with cAMP was impaired which was manifested by the changes in binding kinetics.

Acute Disease↗
PubMedDate not supplied

[Effect of autophosphorylation on binding of cyclic adenosine monophosphate by cAMP-dependent protein kinases from the rat brain after x-irradiation].

The results of the studies on the influence of autophosphorylation on cAMP binding by cAMP-dependent protein kinases isolated from cytosol and solubilized synaptic membranes have demonstrated that this chain in the regulation of the enzyme forms under study exhibits early radiosensitivity, the radiation damage to soluble and membrane enzymes being differently pronounced.

Animals↗
PubMedDate not supplied

[Isolation and properties of the Ca2+, phospholipid-dependent protein kinase from the substantia grisea of the rat brain in the early stage of exposure to ionizing radiation].

Ca2+, phospholipid-dependent proteinkinase was isolated from intact and exposed (1 h following whole body X-irradiation with a dose of 0.21 C/kg) gray substance of rat brain, and the dependence of this enzyme on pH and temperature, and substrate specificity were studied. Changes were shown to occur in some Ca2+, phospholipid-dependent proteinkinase properties under the effect of X-radiation while the substrate specificity remained unchanged.

Animals↗
PubMedDate not supplied

[Activity and properties of cycl AMP-dependent protein kinases in the gray substance of the rat brain in acute radiation injury].

It was shown that in conditions of acute radiation affection there was a decrease of 37% and 32% in activity of cyclic AMP-dependent protein kinases, isolated from cytosol of gray substance of rat brain cells and from the synaptic membranes solubilized by triton X-100, respectively. The activity of enzymes from the control and irradiated animals was maximum with similar concentration of 3':5'-AMP (10(-6) M) and pH (7.4) in Tris-HCl and HEPES-buffers. Histone H4 was shown to be the best substrate for both enzyme forms. Other substrates under study were phosphorylated to a lesser degree.

Acute Disease↗