Publications by authors named "Yu A Vladimirov"

A comparative study of oxidative stress markers (ischemia-modified albumin (IMA) and the blood serum antioxidant capacity) in normal pregnancy and preeclampsia was carried out. The IMA level and blood serum antioxidant capacity increased in the following order: healthy non-pregnant women→healthy pregnant women→patients with moderate preeclampsia→patients with severe preeclampsia (p<0.001).

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  • * Newborns with severe asphyxia showed significant changes, including a 1.6 times increase in IMA, a 2.4 times increase in antioxidant capacity, and a 1.5 times decrease in serum albumin on days 1-2.
  • * By days 3-4, the indicators indicated a reduction in free-radical reactions in asphyxiated newborns, suggesting improvement with complex therapy.
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  • Researchers examined how well extracts from yerba mate can remove Fe(II) ions from water, finding that the aqueous extracts reduced these ions in a dose-dependent manner.
  • The effectiveness is linked to polyphenolic compounds like quercetin and caffeic acid, which can bind to iron and form chelate complexes.
  • The study suggests that this binding process may play a role in yerba mate’s antioxidant properties by altering the absorption spectra of the iron complexes.
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Apoptosis, as the major type of programmed cell death, plays an important role in the organism renewal and removal of defective and transformed cells, including cancer cells. One of the earliest apoptotic events is lipid peroxidation in the inner mitochondrial membrane catalyzed by a complex of cytochrome c (CytC) with the mitochondrial phospholipid cardiolipin (CL). It was shown that mixing CytC and CL solutions results in the formation of CytC/CL complexes (Cyt-CL nanospheres) with a diameter of 11-12 nm composed of the molten globule protein molecule and a CL monolayer.

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  • - The study examined how TLR2 influences the production of reactive oxygen species (ROS) in mouse peritoneal macrophages using a specific chemiluminescence technique when stimulated by different ligands like zymosan and peptidoglycan.
  • - It was found that the levels of ROS produced by macrophages were affected by the concentration ratios of these ligands, indicating that their effects were not independent of each other.
  • - Three main interactions were identified: the combined stimulating effects of the ligands, competition between the ligands for binding, and how prior exposure to peptidoglycan primed macrophages for better response when zymosan was used.
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The complex of mitochondrial protein cytochrome c (CytC) with anionic phospholipid cardiolipin (CL) plays a crucial role in the initiation of apoptosis by catalyzing lipid peroxidation in mitochondrial membranes. In our previous papers, we found that CytC and CL mixed in millimolar concentrations form a sediment showing microcrystals composed of nanospheres (Cyt-CL) of 11-12 and 8 nm in diameter. The hypothesis was proposed that Cyt-CL, having hydrophobic shell, may appear inside the membrane lipid bilayer in mitochondria and peroxidase membrane phospholipids so initiating the apoptotic cascade.

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Functional activity of neutrophils was evaluated by the chemiluminescent method with successive double stimulation by soluble stimuli with different mechanisms of action: phorbol-12-myristate-13-acetate (PMA) and phormyl-methionyl-leucyl-phenilalanine (fMLP). The study was carried out in 26 patients receiving oral sugar-reducing therapy. In addition to the functional activity of neutrophils, the levels of TBA reactive products, inflammation markers, blood clotting values, and biochemical parameters were measured.

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We propose a new approach to evaluation of oxidative stress based on kinetic chemiluminescence: measurement of antioxidant and pro-oxidant activities of the plasma. The study included 50 patients with type 2 diabetes mellitus receiving peroral hypoglycemic therapy. In addition to the above parameters, the levels of TBA-reactive products, inflammation markers, clotting parameters, and biochemical values were studied.

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Oxidative stress is a pathogenetic factor of many diseases. The control of its level is important for early diagnosis and therapy adjustment. In this work, antioxidant status was estimated in blood plasma.

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Programmed cell death (apoptosis) plays an important role in the life of multicellular organisms and in the development of socially significant human diseases. Cytochrome c-cardiolipin complex (Cyt-CL) is formed at the very beginning of a cascade of apoptotic reactions. Nevertheless, the structure of the complex and the mechanism of its participation in lipid peroxidation in mitochondrial membranes are not yet understood.

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Polyelectrolyte multilayers serve as effective reservoirs for bioactive molecules which are stored and released from the multilayers for cellular applications. However, control over the release without significantly affecting the multilayers and biomolecules is still a challenge. On the other hand, externally stimulated release would make the multilayers promising for the development of stimuli-sensitive planar carriers with release performance switched on demand.

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One of the functions of cytochrome c in living cells is the initiation of apoptosis by catalyzing lipid peroxidation in the inner mitochondrial membrane, which involves cytochrome c bound with acidic lipids, especially cardiolipin. In this paper the results of studies of cytochrome c-cardiolipin complex structure carried out by different authors mainly on unilamellar cardiolipin-containing phospholipid liposomes are critically analyzed. The principal conclusion from the published papers is that cytochrome c-cardiolipin complex is formed by attachment of a cytochrome c molecule to the membrane surface via electrostatic interactions and the subsequent penetration of one of the fatty-acid cardiolipin chains into the protein globule, this being associated with hydrophobic interactions that break the >Fe·×·S(Met80) coordinate bond and giving rise to appearance of cytochrome c peroxidase activity.

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The bright chemiluminescence has been observed in the system: Co(2+)/hydrogen peroxide/lucigenin. The chemiluminescence intensity was directly proportional to either cobalt, hydrogen peroxide, or lucigenin concentrations. A procedure of determination of superoxide dismutase (SOD) activity by the chemiluminescence method in the cobalt-hydrogen peroxide-lucigenin system at pH 8.

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Application of chemiluminescence (CL) for study of free-radical reactions in human and animal cells and tissues is considered in this review. Historically, the study of intrinsic (ultraweak) luminescence gave place to the measurement of CL in the presence of chemical activators (CL probes) and physical activators (sensitizers) of luminescence, which made the method much more sensitive and specific. The methods of CL and EPR are direct methods of radical investigation, though the advantage of the CL method consists in the fact that CL intensity is directly proportional to a steady-state concentration of the radicals responsible for luminescence (first of all, lipid and oxygen radicals) irrespective the activity of these radicals.

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Formation of free radicals in mitochondria plays a key role in the development of apoptosis, which includes formation of superoxide by the respiratory chain, formation of radicals by cytochrome c-cardiolipin complex in the presence of hydrogen peroxide or lipids, and chain lipid peroxidation resulting in cytochrome c release from mitochondria and initiation of the apoptotic cascade. In this work the effect of taxifolin (dihydroquercetin) and some other antioxidants on these three radical-producing reactions was studied. Peroxidase activity of the complex of cytochrome c with dioleyl cardiolipin estimated by chemiluminescence with luminol decreased by 50% with quercetin, taxifolin, rutin, Trolox, and ionol at concentrations 0.

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Chemical and biological functions of hemoprotein nitrosyl complexes as well as their photolysis products are discussed in this review. Chemical properties of nitric oxide are discussed, and major chemical reactions such as interaction with thiols, free radicals, and transition metals are considered. Specific attention is paid to the generation of hemoprotein nitrosyl complexes.

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Apoptosis can be induced by activation of so-called "death receptors" (extrinsic pathway) or multiple apoptotic factors (intrinsic pathway), which leads to release of cytochrome c from mitochondria. This event is considered to be a point of no return in apoptosis. One of the most important events in the development of apoptosis is the enhancement of cytochrome c peroxidase activity upon its interaction with cardiolipin, which modifies the active center of cytochrome c.

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In this work, the effect of liposomes consisting of tetraoleyl cardiolipin and dioleyl phosphatidylcholine (1 : 1, mol/mol) on the rate of three more reactions of Cyt c heme with H2O2 was studied: (i) Cyt c (Fe2+) oxidation to Cyt c (Fe3+), (ii) Fe...

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In this work, the actions of bovine heart cardiolipin, synthetic tetraoleyl cardiolipin, and a nonspecific anionic detergent sodium dodecyl sulfate (SDS) on cytochrome c (Cyt c) peroxidase activity recorded by chemiluminescence in the presence of luminol and on the Fe...

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The formation of reactive oxygen and nitrogen species by rat peritoneal macrophages induced by a low-intensity He-Ne laser radiation (LR) was studied in this work. It was found that the formation of reactive oxygen species, nitric oxide, and peroxynitrite as well as changes in the activity of superoxide dismutase (SOD) depended to a large extent on the LR dose. In particular, it was found that activation of SOD at low LR doses was accompanied by nitric oxide level increase, while the level of peroxynitrite showed no significant changes.

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It was shown with the spin trap alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone that myeloperoxidase (MPO) in the presence of its substrates H2O2 and Cl- as well as activated neutrophils destroy tert-butyl hydroperoxide producing two adducts of O-centered radicals which were identified as peroxyl and alcoxyl radicals. Inhibitory analysis performed with traps of hypochlorite (taurine and methionine), free radical scavengers (2,6-di-tret-butyl-4-methylphenol and mannitol), and MPO inhibitors (salicylhydroxamic acid and 4-aminobenzoic acid hydrazide) revealed that the destruction of the hydroperoxide group in the presence of isolated MPO or activated neutrophils was directly caused by the activity of MPO: some radical intermediates appeared as a result of the chlorination cycle of MPO at the stage of hypochlorite generation, whereas the other radicals were produced independently of hypochlorite, presumably with involvement of the peroxidase cycle of MPO. The data suggest that the activated neutrophils located in the inflammatory foci and secreting MPO into the extracellular space can convert hydroperoxides into free radicals initiating lipid peroxidation and other free radical reactions and, thus, promoting destruction of protein-lipid complexes (biological membranes, blood lipoproteins, etc.

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Laser therapy based on the stimulating and healing action of light of low-intensity lasers (LIL), along with laser surgery and photodynamic therapy, has been lately widely applied in the irradiation of human tissues in the absence of exogenous photosensitizers. Besides LIL, light-emitting diodes are used in phototherapy (photobiostimulation) whose action, like that of LIL, depends on the radiation wavelength, dose, and distribution of light intensity in time but, according to all available data, does not depend on the coherence of radiation.

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