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Aim. To study the content of matrix metalloproteinase (MMP)-2, -3, -9 and tissue inhibitors of metalloproteinases (TIMPs) -1, -2, -3, -4 in the aqueous humor of patients with moderate primary open-angle glaucoma (POAG).Materials and methods. The experimental group included 47 patients with verified moderate primary open-angle glaucoma. The control group consisted of 26 patients with uncomplicated cataract. The levels of MMP-2, -3, -9 were determined with Luminex Performance Human MMP Magnetic Panel 3-plex kit (R&D Systems, USA), the concentration of TIMPs-1, -2, -3, - 4 was determined with the Human TIMP Magnetic Luminex Performance Assay 4-plex kit (R&D Systems, USA). The study was carried out using flow-through field fluorometry on a Bio-Plex 200 double-beam laser analyzer (Bio-Rad, USA).Results. The study showed a statistically significant increase in the levels of matrix metalloproteinase-2 and tissue inhibitors of matrix metalloproteinases-1, -2, -3, -4 in the aqueous humor of patients with moderate POAG compared with patients with uncomplicated cataract.Conclusion. The obtained data on high concentrations and imbalance in the levels of matrix metalloproteinases and their tissue inhibitors in the aqueous humor of patients with moderate POAG confirm the role of local inflammation, as well as impairments in the structure of the extracellular matrix and its remodeling in the mechanisms of development of this pathology.

Purpose. To study the content of cytokines and growth factors in the intraocular fluid of patients with developed stage of primary open-angle glaucoma (POAG).Materials and methods. 56 patients with a verified diagnosis developed stage of primary open-angle glaucomawere examined. The control group consisted of 30 patients with a diagnosis of uncomplicated cataract. A concentration of 17 cytokinesand 3 isoforms of the transforming growth factor (TGF) β was determined using a Bio-Plex Pro™ Human Cytokine 17-plex Assay and Bio-Plex Pro™ and TGFβ 3-plex Assay kit by flow-through fluorometry on a Bio-Plex 200, Bio-Rad double beam laser analyzer, USA.Results. Astatistically significant increase was shown in the concentrations of cytokines and growth factors (interleukins (IL) 4, 6, 7, 8, 12, 17, TGFβ 1, 2, 3, macrophage inflammatory protein 1 β) in the intraocular fluid of patients with developed stage of the primary open-angle glaucoma in respect to data obtained from the study of the intraocular fluid of the persons with uncomplicated cataract, as well as a statistically significant decrease in the concentrations IL-2, IL-10, granulocyte-macrophage colony-stimulating factor.Conclusion. In the pathogenesis of primary open-angle glaucoma, the activity of the local chronic inflammatory process is determined. This is confirmed by statistically significant changes in the studied cytokines and growth factors. Increase in the concentrations of the studied representatives of the superfamily of transforming growth factors-beta, which have anti-inflammatory activity, the ability to stimulate proliferation, cell growth, synthesis of extracellular matrix proteins, etc., attests to their importance in the mechanisms of primary open-angle glaucoma development. Increase concentrations of IL-7 in the intraocular fluid of patients with primary open-angle glaucoma allows us to assume participation in the pathogenesis of the primary open-angle glaucoma of this autocrine mediator of activation of the growth of lymphatic structures.

Diabetic retinopathy (DR) is one of the leading causes of avoidable blindness worldwide. Chronic low-grade inflammation and abnormal angiogenesis, which is considered to be principal components of DR pathogenesis, is accompanied by imbalance in cytokine production. It was shown that single-nucleotide polymorphisms (SNPs) in the promoters of cytokine genes affect the cytokine production in normal and pathological conditions. Accordingly, we aimed to assess the frequencies of combinations of SNPs from promoters of cytokine genes in type 2 diabetic subjects with and without DR.Materials and methods: We enrolled 201 caucasian subjects with type 2 diabetes, including 90 ones with non-proliferative or preproliferative retinopathy and 111 subjects without DR. Eight SNPs, located in the gene promoters of TNFA (rs1800630, rs1800629, rs361525), IL1B (rs1143627), IL4 (rs2243250), IL6 (rs1800795) and IL10 (r1800896, rs1800872), were investigated. In groups of patients with and without DR, the frequencies of alleles, genotypes and their combinations, odds ratios and specificity were calculated. The networks between genes and quartiles of glycated hemoglobin A1c (HbA1c) were visualized with Cytoscape.Results. We revealed 36 combinations of SNPs with different frequencies in the groups of patients with and without DR. In the combinations associated with DR with a specificity >99% homozygous GG genotype in position -174 of IL6 (rs1800795), CT genotype in position -31 of IL1B (rs1143627), СС genotype in position -592 of IL10 (rs1800872), CT genotype in position -590 of IL4 (rs2243250) were the most frequently detected variants. High levels of HbA1c (>9.8%) were associated with combinations of CA genotype in position -863 TNFA (rs1800630) with homozygous variants GG in positions -238 and -308 TNFA (rs1800629, rs361525).Conclusion. Genetic combinations, associated with DR in type 2 diabetic subjects, include homozygous variants in polymorphic positions of the gene promoters of IL6 (rs1800795), IL1B (rs1143627) and TNFA (rs1800630, rs1800629, rs361525). The combinations of the variants of cytokine genes with a high level of HbA1c can be an important mechanism for realizing of individual genetic predisposition to the development of DR.

Measures for ensuring reliable and safe operation of a tube sheet in the steam generators in nuclear power plants with VVER reactors are examined and validated. The reasons for and mechanisms of the damage occurring to the tube sheets in steam generators are examined. The results of experimental studies evaluating the corrosion effect of the working medium in the second loop on the tube sheet are presented and it is shown that the defects detected by eddy-current monitoring form predominately in the startup and nonstationary operating regimes of steam generators as well as during disruptions of the water-chemistry regime. Suggestions are made for optimizing the water-chemistry regime of the second loop and for preserving a steam generator during downtime. [ABSTRACT FROM AUTHOR]

The steam generator is a very important component of a nuclear power plant. Historically, vertical steam generators came to be used abroad and horizontal steam generators in our country. Both types of steam generators operate successfully in nuclear power plants and satisfactorily fulfill their functions, enabling the production of electricity. Repeated attempts to re-examine the existing concepts in one or another country have been unsuccessful because there are no convincing arguments for this. Nonetheless, the question of using a different type of steam generator is raised periodically in our country and abroad. This article briefly reviews different concepts of steam generators. Their parameters, characteristics, and thermal efficiency are compared and ways to increase the latter are analyzed. It is shown that it is impossible to choose one or the other type of steam generator without making an exhaustive study and analysis of the layout of the reactor facility and its scheme, servicing, and operation as part of a nuclear power plant. A comparative analysis of layouts of reactor facilities with different types of steam generators is made. [ABSTRACT FROM AUTHOR]

Abstract  Features of the metrology of quantum multiparticle systems in connection with general system theory and representational theory are considered. Quantitative characteristics of the periodic system of elements (PSE) are introduced and studied, including property correlation, and also system hierarchies are considered leading to its analysis and possible application of nanosystems and quantum computers. [ABSTRACT FROM AUTHOR]

The construction of the PGN-200M steam generator of a BN-600 power-generating unit at the Beloyarskaya nuclear power plant is described. Data from 25 years of operation are presented and the basic questions which were solved during the startup-adjustment work, which increased the operational reliability of the steam generator, are elucidated. The advantages of steam generators with different designs are compared, and it is concluded that it is desirable to develop a high-power sodium-cooled vessel steam generator for future facilities. [ABSTRACT FROM AUTHOR]

The basic questions concerning the development of a steam generator for a nuclear power plant with a VVÉ R-1500 reactor are presented. The basic design requirements which follow for steam generators from experience in operating analogs at nuclear power plants and taking account of the requirements for a reactor system are presented. The special features inherent to horizontal-type steam generators, which have been mastered and are used in nuclear power plants in our country, are noted. The domestic and world operating experience is taken into account in the development of the design. [ABSTRACT FROM AUTHOR]

With regard to applications in quantum theory, we consider the classical wave equation involving the scalar curvature with an arbitrary coefficient ξ. General properties of this equation and its solutions are studied based on modern results in group analysis with the aim to fix a physically justified value of ξ. These properties depend essentially not only on the values of ξ and the mass parameter but also on the type and dimension of the space. Form invariance and conformal invariance must be distinguished in general. A class of Lorentz spaces in which the massless equation satisfies the Huygens principle and its Green's function is free of a logarithmic singularity exists only for the conformal value of ξ. The same value of ξ follows from other arguments and the relation to the known WKB transformation method that we establish. [ABSTRACT FROM AUTHOR]

Purpose: The purpose was to measure the concentrations of various cytokines and growth factors (including vascular endothelial growth factor [VEGF] and pigment epithelium-derived factor [PEDF]) in the vitreous of patients with proliferative diabetic retinopathy (PDR) and to investigate interaction between inflammatory and proliferative factors in the genesis of PDR. Materials and Methods : Vitreous samples from 32 eyes with PDR and 25 eyes without diabetes mellitus and signs of DR (control) were collected. Vitreous concentrations of VEGF, PEDF, monocyte chemotactic protein-1 (MCP-1), interleukin-4 (IL-4), IL-6, IL-8, IL-10, IL-17A, and secretory immunoglobulin A (sIgA) were simultaneously measured using enzyme-linked immunoassay. Results : Vitreous levels of VEGF, PEDF, IL-17A, IL-6, IL-8, IL-4, and sIgA were significantly (Π < 0.05) higher in eyes with PDR compared to control. The concentration of VEGF was more than 17-times higher than in control, and the concentration of PEDF was not changed oppositely and was also higher (1.45-times) compared to control, that may indicate disturbances of compensatory mechanisms in angiogenesis regulation in PDR. Significant (Π < 0.05) positive correlations were observed between vitreous concentrations of VEGF and IL-17ΐ (r = 0.45), VEGF and IL-8 (r = 0.48), VEGF and IL-4 (r = 0.51), PEDF and IL-17ΐ (r = 0.48), PEDF and IL-8 (r = 0.59), MCP-1 and PEDF (r = 0.72), MCP-1 and IL-8 (r0 = 0.45), IL-4 and IL-17ΐ (r = 0.65), IL-4 and IL-8 (r = 0.71), IL-8 and IL-17ΐ (r = 0.59). Conclusions: Significantly raised levels of inflammatory and proliferative factors and numerous positive correlations between them may demonstrate a significant role of activation of vascular proliferation and local inflammation in the pathogenesis of PDR.

Objectives. To investigate the possible role of cystatin C in eye biological fluids locally and in serum and lactoferrin revealing anti-tumor activity in eye tumor development. Background. The increased number of eye tumors was registered recently not only in the countries with high insolation, but also in the northern countries including Russia (11 cases per million of population). Search for new biological markers is important for diagnosis and prognosis in eye tumors. Cystatin C, an endogenous inhibitor of cysteine proteases, plays an important protective role in several tumors. Lactoferrin was shown to express anti-tumor and antiviral activities. It was hypothesized that cystatin C and lactoferrin could serve as possible biomarkers in the diagnosis of malignant and benign eye tumors. Study design. A total of 54 patients with choroidal melanoma and benign eye tumors were examined (part of them undergoing surgical treatment). Serum, tear fluid and intraocular fluid samples obtained from the anterior chamber of eyes in patients with choroidal melanoma were studied. Methods. Cystatin C concentration in serum and eye biological fluids was measured by commercial ELISA kits for human (BioVendor, Czechia); lactoferrin concentration – by Lactoferrin-strip D 4106 ELISA test systems (Vector-BEST, Novosibirsk Region, Russia). Results. Cystatin C concentration in serum of healthy persons was significantly higher as compared to tear and intraocular fluids. In patients with choroidal melanoma, increased cystatin C concentration was similar in tear fluid of both the eyes. Lactoferrin level in tear fluid of healthy persons was significantly higher than its serum level. Significantly increased lactoferrin concentration in tear fluid was noted in patients with benign and malignant eye tumors. Conclusion. Increased level of cystatin C in tear fluid seems to be a possible diagnostic factor in the eye tumors studied. However, it does not allow us to differentiate between malignant and benign eye tumors. Similar changes were noted for lactoferrin in tear fluid.