RX J0720.4--3125 as a Possible Example of the Magnetic Field Decay of Neutron Stars

We studied possible evolution of the rotational period and the magnetic field of the X-ray source RX J0720.4-3125 assuming this source to be an isolated neutron star accreting interstellar medium. Magnetic field of the source is estimated to be $10^6 - 10^9$ G, and it is difficult to explain observed rotational period 8.38 s without invoking hypothesis of the magnetic field decay. We used the model of ohmic decay of the crustal magnetic field. The estimates of accretion rate ($10^{-14} - 10^{-16} M_\odot/yr$), velocity of the source relative to interstellar medium ($10 - 50$ km/s), neutron star age ($2\cdot 10^9 - 10^{10}$ yrs) are obtained.Comment: 12 pages (LATEX), 2 PostScript figures. Also available at http://xray.sai.msu.su/~polar/ (with the Russian variant of the article

Population synthesis of old neutron stars in the Galaxy

The paucity of old isolated accreting neutron stars in ROSAT observations is used to derive a lower limit on the mean velocity of neutron stars at birth. The secular evolution of the population is simulated following the paths of a statistical sample of stars for different values of the initial kick velocity, drawn from an isotropic Gaussian distribution with mean velocity $0\leq < V>\leq 550$ ${\rm km s^{-1}}$. The spin-down, induced by dipole losses and the interaction with the ambient medium, is tracked together with the dynamical evolution in the Galactic potential, allowing for the determination of the fraction of stars which are, at present, in each of the four possible stages: Ejector, Propeller, Accretor, and Georotator. Taking from the ROSAT All Sky Survey an upper limit of $\sim 10$ accreting neutron stars within $\sim 140$ pc from the Sun, we infer a lower bound for the mean kick velocity, \ga 200-300 ${\rm km s^{-1}}$. The same conclusion is reached for both a constant ($B\sim 10^{12}$ G) and a magnetic field decaying exponentially with a timescale $\sim 10^9$ yr. Present results, moreover, constrain the fraction of low velocity stars, which could have escaped pulsar statistics, to \la 1%.Comment: 8 pages, 4 PostScript figures, to appear in the proceedings of IAU Symposium 19

Silver containing sorbents: Physicochemical and biological properties

New silver containing sorbents, based on mineral carriers, such as alumina and silica systems with a meso- and macro- porous structure, have a higher mechanical resistance and, hydrophilic and hydrophobic chemical composition of the surface. These sorbents are easy to find and relatively inexpensive, compared to their known equivalents. They are furthermore characterised by high specific surface and simple preparation, whilst the addition of silver considerably increases their antiseptic activity. The results of research of the physical, chemical and biological properties of the developed substances, as well as bio-comparability of sorbents with biological tissues, are presented in this paper. The modified material acts simultaneously as the carrier for active substances to the area of therapeutic application and as a sorbent used to remove toxic agents from such areas. This approach led us to modify the sorbent, and prolong the delivery of substances such as silver, as an effective antibacterial and antimycotic agent

Content of matrix metalloproteinases in the intraocular fluid of patients with primary open-angle glaucoma

Aim of the study was to investigate the content of matrix metalloproteinases 2, 3, 9, in the intraocular fluid of patients with a developed stage of primary open-angle glaucoma. Material and methods. The study included 47 patients with advanced stage of primary open-angle glaucoma. The diagnosis is based on ophthalmological examination, including visual acuity, binocular ophthalmoscopy, spheroperimetry, echoophthalmography, optical coherence tomography, intraocular pressure measurement. Exclusion criteria were acute and exacerbation of chronic inflammatory diseases of the organ of vision, diabetic retinopathy, neovascular glaucoma, uveitis, hemophthalmia, autoimmune and tumor processes of any localization, as well as acute and exacerbations of chronic inflammatory diseases of any organs and systems. Patients who took for normalization of intraocular pressure drugs containing analogues of prostaglandins, that could activate the inflammatory process, were excluded from the study. 26 patients with a diagnosis of uncomplicated cataract made up a comparison group. All patients underwent determination of matrix metalloproteinases (MMP) 2, 3, 9 in the intraocular fluid. Results. Concentration of MMP-2 but not MMP-3 or MMP-9 is statistically significantly higher in the intraocular fluid of patients with a developed stage of primary open-angle glaucoma compared to individuals with uncomplicated cataracts. This may indicate importance of MMP-2 in the development of a local aseptic inflammatory process, impaired extracellular matrix and «remodeling» of the tissue structures of the organ of vision, leading to disruption of the outflow of intraocular fluid, which is an important factor in the pathogenesis of primary open-angle glaucoma

Composition based on aluminum oxide and polydimethylsiloxane matrix for enhancing drug targeting

Methodological approaches developed at Research Institute of Clinical and Experimental Lymphology for a number of years allow formulating the importance of embedding active pharmaceutical ingredients (API) in the structure of porous carriers (sorbents). The composition of the carrier and API is an enteral system for prolonged dosing of pharmacological agents, which allows providing a specific pharmacological effect and safety of use. The pores of the media (sorbents) act as containers for API. This is especially important for rapidly absorbed drugs, which include, for example, lithium preparations that are used in narrow concentration limits due to their side effects. At the moment, an innovative technology for creating new medicines with an improved combination of efficiency and safety (pharmacological upgrade) has been developed and implemented. The essence of the technology is to create a composition of aluminum oxide and polydimethylsiloxane (matrix) and an active pharmacological ingredient (API). A study of two drugs based on matrix / lithium citrate and matrix / melatonin showed continued specific pharmacological activity of API, better pharmacokinetics, and better safety parameters. The matrix of aluminum oxide and polydimethylsiloxane provides an upgrade of the pharmacological properties of drugs for the dosed and safe delivery of API to the zone of their therapeutic effect

THE ELEMENTS OF INTRAOCULAR FLUID LYMPHATIC OUTFLOW PATHWAYS IN CHOROID IN NORM AND IN GLAUCOMA PATIENTS

Purpose. To detect and study the structure of aqueous humor lymphatic outflow pathways in choroid in normotensive patients and patients with primary open-angle glaucoma (POAG).Material and methods. Choroid fragments of seven human eyes (including two eyes with terminal glaucoma) enucleated on medical indications were studied. The structure of the choroid was investigated using immunohistochemistry and electron microscopy.Results. Lymphatic channels and lymphatic lacunae were revealed in the choroid structure. Lymphatic channels were detected in choriocapillar and vascular layers and were limited by Podoplanin+, Prox-1+, LYVE-1+ endothelium-like cells, fibroblasts and pigment cells. Lymphatic lacunae were located in suprachoroid layer and covered with endothelium-like cells and fibroblasts. Morphometric study showed an increase of the volume density of epithelium, interstitial spaces and choroid vessels related to edema and swelling of the choroidal stroma in the terminal stage of glaucoma.Conclusions. Human choroid contains lymphatic structures that are probably a part of the ocular lymphatic drainage system and participate in the aqueous humor outflow. Choroidal edema and swelling, the increase of the volume density of epithelium, interstitial spaces and choroid vessels in the terminal POAG stage indicate the lymphatic drainage dysfunction beginning from initial stages of glaucoma and lead to an aqueous humor outflow alteration through the protective lymphatic system

Complex studies on gene polymorphisms of MMP2, MMP3, MMP9 matrix metalloproteinases and TIMP1, TIMP2 tissue inhibitors of metalloproteinases in the patients with primary open-angle glaucoma

Abnormal expression of matrix metalloproteinases (MMP) in watery moisture in patients with glaucoma may affect regulation of intraocular pressure (IOP). MMP activity is regulated by tissue metalloproteinase inhibitors (TIMP). The imbalance between tissue metalloproteinase inhibitors and matrix metalloproteinases may contribute to the development of glaucoma. Genetic factors, including polymorphism of matrix metalloproteinase genes and their inhibitors genes, can regulate the level of their expression, thereby affecting susceptibility to disease. Our aim was to perform comprehensive analysis of the MMP2 (rs243865), MMP3 (rs3025058), MMP9 (rs3918242) polymorphisms, and TIMP1 (rs4898), TIMP2 (rs8179090) tissue inhibitor genes polymorphisms in the patients with stage II (advanced) primary open-angle glaucoma.99 patients (52 men and 47 women) with a verified diagnosis of stage II primary open-angle glaucoma were examined. The comparison group consisted of 100 age-matched persons (81 women and 19 men) without ophthalmic disorders. The single-nucleotide polymorphisms in promoter regions of MMP2, TIMP1, TIMP2 genes were analyzed by the TaqMan method, the MMP3 and MMP9 genes, by means of restriction fragment length polymorphism technique. Statistical evaluation was carried out using the specialized package of IBM SPSS Statistics 23 programs. The critical level of significance was assumed to be 0.05.The differences in the distribution of MMP2 rs243865 allelotypes with decreased frequency of TT genotype were found in the patient group and, vice versa, increased heterozygosity rates were revealed among them. In addition, the frequency of TIMP1 rs4898 heterozygous genotype was decreased in this group as compared to control sample. Four MMP/TIMP complex genotypes are positively associated with the development of pathology. Two of them were of bilocus type, i.e., MMP2-1306TC:TIMP2-418GG, and MMP3-11715A6A:TIMP1 372CC whereas two three-locus constellations were revealed, i.e., MMP2-1306TC:MMP9-1562CC:TIMP2- 418GG, and MMP3-11715A6A:MMP9-1562CC:TIMP1 372CC. There are nine MMP/TIMP complexes, the frequency of which in patients with glaucoma was significantly reduced when compared with control group.Polymorphism of regulatory regions of MMP2, MMP3, MMP9 genes and distinct gene variants of their inhibitors (TIMP1, TIMP2 genes) can be considered potential markers of the POAG development associated with an imbalance of MMP/TIMP activities

SERUM LEVELS OF HEMOPOIETIC AND ANGIOGENESIS GROWTH FACTORS (IL-5, IL-7, IL-9, FGF-β, G-CSF, VEGF AND PDGF) IN WOMEN WITH UTERINE MYOMA

Uterine leiomyomas are common benign tumors developing from smooth muscle tissues, often leading to infertility and recurrent abortions. Pregnancy and development of uterine fibroids are characterized by an unusual rate of myometrium growth, hyperproduction of extracellular matrix and increased expression of numerous growth factor receptors. The purpose of this study was to determine concentrations of some key growth factors (IL-5, IL-7, IL-9, FGF-β, G-CSF, VEGF and PDGF) in blood serum of women with uterine myoma. Concentrations of the 27 cytokines were determined using a Bio Rad kit (USA) – Bio-Plex Pro™. Human Cytokine 27-plex Assay by means of flow-through fluorometry at the Bio-Plex 200 double-beam laser analyzer. Thirty-six patients with verified uterine myoma were followed up, being later subject to operative treatment (laparoscopic myomectomy). The results of this study showed a trend to decreased amounts of some hematopoiesis and angiogenesis growth factors, e.g., IL-9 and FGF, in blood serum of women with uterine myoma. Сoncentrations of IL-5, IL-7, and G-CSF proved to be significantly decreased if compared to serum contents of European healthy women. The most significant decrease was registered for pro-angiogenic factors, such as VEGF and PDGF. Their serum concentration in women with leiomyoma was reduced, respectively, 3- and 6-fold against controls. The decreased G-CSF concentration was not only quite significant, as compared to healthy women, but showed significant correlations with changes of such factors as IL-5, IL-7 and IL-9, with correlation quotients of, resp., 0.723, 0.637, and 0.504, respectively. One may conclude that, in spite of literature data on significantly increased contents of the mentioned growth factors in tissues of myometrium and growing uterine leiomyoma, our data show that the concentrations of these regulatory proteins in blood serum are decreased to some extent in this clinical condition

POLYMORPHISMS OF EXTRACELLULAR CONNECTIVE TISSUE REMODELING PROTEINASES AND <i>MMP2, MMP3, MMP9</i> GENES, AND NEOANGIGENESIS <i>VEGF</i> GENE IN RETINAL MICROANGIOPATHY IN THE PATIENTS WITH TYPE 2 DIABETES MELLITUS

The aim of our study was to perform an association analysis between MMP2, MMP3, MMP9, VEGF gene polymorphisms and development of non-proliferative diabetic retinopathy (DR) in the type 2 diabetic patients (DM).201 DM patients: 90 cases of DR and 111 subjects without DR features were included into the study. Polymorphic variants of MMP2 (rs2438650), MMP3 (rs3025058), MMP9 (rs3918242), and VEGF (rs699947 and rs3025039) genes were assayed. The genetic typing was carried out by restriction fragment length polymorphism and TaqMan methods.The analysis of complex genotypes at the five polymorphic positions has revealed some significant findings in positive and negatively incorporated complexes. Increased frequencies of MMP2-1306 CC genotype in the group of patients with “early” development of complication, and more frequent combination of high-level HbA1c with MMP2-1306CC and MMP9-1562CT genotypes were shown in DR patients. Computerassisted modelling with visual reconstruction of network interactions between the genotypes involved into the destruction events and angiogenesis, as well as altered HbA1с levels (an integral parameter of glycemia), has revealed some differences in structural and functional organization of gene-gene and gene- protein interactions between the groups of patients with DR versus those without this disorder. Сonclusion. A design of interactome biological networks based on transcription regulation and metabolic pathways, as well as their topological analysis allows to build and study interactions of genes and proteins, with reference to pathogenetic studies of DM2 complications aiming for development of approaches to personalized prevention and therapy in future times