Pilot hearing screening in school age children in Republic of Moldova

Introduction: Many countries have implemented newborn hearing screening programs, resulting in early intervention and therapy. In spite of that, there is a significant number of schoolchildren with hearing problems. Hearing loss is a common and considerable disability that harms educational performance of schoolchildren in developing countries. Lack of a simple and practical screening protocol often deters routine and systematic hearing screening at school entry. Purpose and Objectives: The pilot study assessing the hearing in the population of pupils who begin their education in five random primary schools in Moldova. Material and Methods: Hearing screening was conducted in a group of 179 children from three primary schools in Chisinau in Republic of Moldova. Screening was performed using the Sense Examination Platform; on the basis of the audiometric procedure of measuring the hearing threshold. Positive result of hearing screening was defined as equal as or more than 25dB at least at one frequency in either ear. Additionally subjective assessment was carried out on the basis of parents questionnaires. Results: The study was performed in 3 schools: in the 1st were examined 69 children, from which a positive result was at 8.7%, in the 2nd - 52 (25% positive) and in the III-rd - 58, with positive result at 10.34%. A total of 179 children were examined, out of which at 13.97% - a positive test result'. All children with positive results of hearing screening were examined by local otolaryngologists. Conclusions: The obtained results confirm the significant prevalence of hearing problems in school-aged children. Based on the results, the implementation of hearing screening as a routine procedure in the medical care in schools is strongly recommended

Ribosomal oxygenases are structurally conserved from prokaryotes to humans

2-Oxoglutarate (2OG)-dependent oxygenases have important roles in the regulation of gene expression via demethylation of N-methylated chromatin components1,2 and in the hydroxylation of transcription factors3 and splicing factor proteins4. Recently, 2OG-dependent oxygenases that catalyse hydroxylation of transfer RNA5,6,7 and ribosomal proteins8 have been shown to be important in translation relating to cellular growth, TH17-cell differentiation and translational accuracy9,10,11,12. The finding that ribosomal oxygenases (ROXs) occur in organisms ranging from prokaryotes to humans8 raises questions as to their structural and evolutionary relationships. In Escherichia coli, YcfD catalyses arginine hydroxylation in the ribosomal protein L16; in humans, MYC-induced nuclear antigen (MINA53; also known as MINA) and nucleolar protein 66 (NO66) catalyse histidine hydroxylation in the ribosomal proteins RPL27A and RPL8, respectively. The functional assignments of ROXs open therapeutic possibilities via either ROX inhibition or targeting of differentially modified ribosomes. Despite differences in the residue and protein selectivities of prokaryotic and eukaryotic ROXs, comparison of the crystal structures of E. coli YcfD and Rhodothermus marinus YcfD with those of human MINA53 and NO66 reveals highly conserved folds and novel dimerization modes defining a new structural subfamily of 2OG-dependent oxygenases. ROX structures with and without their substrates support their functional assignments as hydroxylases but not demethylases, and reveal how the subfamily has evolved to catalyse the hydroxylation of different residue side chains of ribosomal proteins. Comparison of ROX crystal structures with those of other JmjC-domain-containing hydroxylases, including the hypoxia-inducible factor asparaginyl hydroxylase FIH and histone Nε-methyl lysine demethylases, identifies branch points in 2OG-dependent oxygenase evolution and distinguishes between JmjC-containing hydroxylases and demethylases catalysing modifications of translational and transcriptional machinery. The structures reveal that new protein hydroxylation activities can evolve by changing the coordination position from which the iron-bound substrate-oxidizing species reacts. This coordination flexibility has probably contributed to the evolution of the wide range of reactions catalysed by oxygenases

Structural Basis for Substrate Specificity in Human Monomeric Carbonyl Reductases

Carbonyl reduction constitutes a phase I reaction for many xenobiotics and is carried out in mammals mainly by members of two protein families, namely aldo-keto reductases and short-chain dehydrogenases/reductases. In addition to their capacity to reduce xenobiotics, several of the enzymes act on endogenous compounds such as steroids or eicosanoids. One of the major carbonyl reducing enzymes found in humans is carbonyl reductase 1 (CBR1) with a very broad substrate spectrum. A paralog, carbonyl reductase 3 (CBR3) has about 70% sequence identity and has not been sufficiently characterized to date. Screening of a focused xenobiotic compound library revealed that CBR3 has narrower substrate specificity and acts on several orthoquinones, as well as isatin or the anticancer drug oracin. To further investigate structure-activity relationships between these enzymes we crystallized CBR3, performed substrate docking, site-directed mutagenesis and compared its kinetic features to CBR1. Despite high sequence similarities, the active sites differ in shape and surface properties. The data reveal that the differences in substrate specificity are largely due to a short segment of a substrate binding loop comprising critical residues Trp229/Pro230, Ala235/Asp236 as well as part of the active site formed by Met141/Gln142 in CBR1 and CBR3, respectively. The data suggest a minor role in xenobiotic metabolism for CBR3. ENHANCED VERSION: This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S1

High-Affinity Inhibitors of Human NAD+-Dependent 15-Hydroxyprostaglandin Dehydrogenase: Mechanisms of Inhibition and Structure-Activity Relationships

BACKGROUND: 15-Hydroxyprostaglandin dehydrogenase (15-PGDH, EC 1.1.1.141) is the key enzyme for the inactivation of prostaglandins, regulating processes such as inflammation or proliferation. The anabolic pathways of prostaglandins, especially with respect to regulation of the cyclooxygenase (COX) enzymes have been studied in detail; however, little is known about downstream events including functional interaction of prostaglandin-processing and -metabolizing enzymes. High-affinity probes for 15-PGDH will, therefore, represent important tools for further studies. PRINCIPAL FINDINGS: To identify novel high-affinity inhibitors of 15-PGDH we performed a quantitative high-throughput screen (qHTS) by testing >160 thousand compounds in a concentration-response format and identified compounds that act as noncompetitive inhibitors as well as a competitive inhibitor, with nanomolar affinity. Both types of inhibitors caused strong thermal stabilization of the enzyme, with cofactor dependencies correlating with their mechanism of action. We solved the structure of human 15-PGDH and explored the binding modes of the inhibitors to the enzyme in silico. We found binding modes that are consistent with the observed mechanisms of action. CONCLUSIONS: Low cross-reactivity in screens of over 320 targets, including three other human dehydrogenases/reductases, suggest selectivity of the present inhibitors for 15-PGDH. The high potencies and different mechanisms of action of these chemotypes make them a useful set of complementary chemical probes for functional studies of prostaglandin-signaling pathways. ENHANCED VERSION: This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S2

THE US GLOBAL CITIES AS HUBS FOR FOREIGN TRANSNATIONAL CORPORATIONS

Despite the acknowledgment of the global city concept and the importance of transnationalization processes in their formation, the debate regarding global city identification methods continues. The article stresses the need to change our approach in evaluating global cities by primarily looking at them as locales for foreign multinational corporations. By analyzing the location decisions of foreign TNCs included in the Forbes 2000 rankings two things become apparent: the “nodality” of US global cities and their hierarchical pattern. Moreover, the article recognizes the key role that Alpha global cities play by leading the country’s international business relations, examined through foreign TNCs. Using our methodology and data on foreign TNCs we defined five uneven groups of cities are defined in the study: city-hegemon New York, leading cities, heavyweight cities, middleweight cities and cities-outsider. The article defines some key factors that determine city’s attractiveness for foreign multinationals: its geo-economical power, functional specialization, location, historical and cultural ties, position on different sectoral markets. The study of US global cities as hubs for foreign transnational corporations seems to be especially useful for Russian cities, especially Moscow and St. Petersburgh, which aim to increase the attractiveness for foreign investment

Nove matrix metaloproteinazy v cyklickem endometriu

OBJECTIVE: To examine the expression pattern of some novel matrix metalloproteinases (MMPs) in cycling endometrium. DESIGN: Experimental study. SETTING: Department of Obstetrics and Gynecology of the Palacky University Medical School and University Hospital, Olomouc, Czech Republic, Department of Obstetrics and Gynecology, University Hospital, Lund, Sweden. METHODS: We studied MMP-12, -16, -17, -19 and -26 mRNA in 39 normal endometrial samples obtained across the menstrual cycle. Based on histological examination, all specimens were classified according to an ideal 28 day menstrual cycle as early (n=8), mid (n=6) and late (n=7) proliferative phase, early (n=4), mid (n=4) and late (n=8) secretory phase and menstrual (n=3) phase. Cycle variation was examined in frozen samples using in situ hybridization. RESULTS: Three distinct pattern of MMP mRNA expression were detected in cycling endometrium. MMP-12 was expressed predominantly in perimenstrual period, MMP-16, -17 and 19 were expressed throughout the cycle and MMP-26 was found to be maximal in periovulatory period. CONCLUSION: Different endometrial expression patterns of novel MMPs during menstrual cycle may indicate their specific roles for menstruation, endometrial growth and remodelling and implantation

MMP-26 mRNA and estrogen receptor alpha co-expression in normal and pathological endometrium

OBJECTIVE: To examine the expression pattern of matrix metalloproteinase-26 (MMP-26) mRNA and estrogen receptor-alpha (ER alpha) in normal, hyperplastic, premalignant and malignant endometrial tissue. DESIGN: Experimental study. SETTING: Department of Obstetrics and Gynecology of the Palacky University Medical School and University Hospital, Olomouc, Czech Republic, Department of Obstetrics and Gynecology, University Hospital, Lund, Sweden, Atherosclerosis Research Unit, King Gustav V Research Institute, Karolinska Hospital, Stockholm, Sweden. METHODS: We studied MMP-26 mRNA and ER alpha in 36 normal, 7 hyperplastic, 6 premalignant and 19 malignant endometrial samples. Based on histological examination, all normal specimens were classified according to an ideal 28 day menstrual cycle as early, mid, and late proliferative phase, early, mid and late secretory phase and menstrual phase. Samples with hyperplasia were classified as simple or complex. Premalignant samples were represented by complex hyperplasia with atypia. Malignant samples were histologically classified as well, intermediately and poorly differentiated, respectively. Specimens were analyzed using in situ hybridization and real time PCR. ER alpha was localized by immunohistochemistry. RESULTS: Epithelial MMP-26 mRNA expression was highest in the early secretory phase and in endometrial hyperplasia. Expression levels were low in the late secretory and menstrual phase and in malignant samples decreased gradually with dedifferentiation. Expression pattern of MMP-26 mRNA in normal, hyperplastic, premalignant and malignant endometrial tissue strongly co-variated with that of ER alpha. CONCLUSION: Co-expression of MMP-26 and ER alpha in normal and pathological endometrial tissue suggests possible regulation of MMP-26 gene by estrogen

Exprese MMP-26 v endometrialnich explantech pod vlivem estradiolu a progesteronu

OBJECTIVE: To examine possible estrogen dependent endometrial expression of MMP-26 in vitro. DESIGN: Experimental study. SETTING: Department of Obstetrics and Gynecology of the Palacky University Medical School and University Hospital, Olomouc, Czech Republic, Department of Obstetrics and Gynecology, University Hospital, Lund, Sweden. METHODS: We studied MMP-26 mRNA in 14 normal endometrial samples obtained from the proliferative phase of the menstrual cycle. Samples were cultured for five days either with estradiol alone or in combination with progesterone. Samples cultured with ethanol represented control groups. MMP-26 mRNA expression was examined in frozen samples using in situ hybridization. Immunohistochemistry was used to study the presence of estrogen and progesterone receptors in endometrial explants. RESULTS: MMP-26 mRNA expression was highest in fresh (non cultured) samples. Signal intensity decreased during the first two days of culture and was negligable in the following days. Nuclear intensity for estrogen and progesterone receptor was high after five days of culture. CONCLUSION: We did not find MMP-26 mRNA in vitro expression to be directly estrogen dependent

Profily endometrialni exprese mRNA u vybranych matrix metaloproteinaz a tkanoveho inhibitoru metaloproteinaz-1

OBJECTIVE: To examine the endometrial expression pattern of messenger RNA (mRNA) for selected matrix metalloproteinases (MMP) and tissue inhibitor of metalloproteinases-1 (TIMP-1). DESIGN: Experimental study. SETTING: Department of Obstetrics and gynecology of the Palacky University Medical School and University Hospital, Olomouc, Czech Republic, Department of Obsterics and Gynecology, University Hospital, Luna, Sweden. METHODS: We studied MMP-1, -3, -7, -10, -11, -12, -13, -14, -16, -26 and TIMP-1 mRNA in 39 normal endometrial samples obtained across the menstrual cycle. Based on histological examination, all specimens were classified according to an ideal 28 day menstrual cycle as early (n=8), mid (n=6) and late (n=7) proliferative phase, early (n=4), mid (n=4) and late (n=8) secretory phase and menstrual (n=3) phase. mRNA extracted from frozen tissue samples was quantitated using real time PCR. RESULTS: Four distinct patterns of MMP mRNA expression were detected in cycling endometrium. MMP-1, -3, -10, and -12 were expressed predominantly in perimenstrual period, MMP-7 and -11 had highest levels in proliferative phase, MMP-13, -14 and -16 were expressed throughout the cycle and MMP-26 was found to be maximal in periovulatory period. Levels of TIMP-1 mRNA remained unchanged during the cycle. CONCLUSION: The specific endometrial expression profiles of MMPs during menstrual cycle point to their specific biologic roles during the cycle. MMP-26 exhibits a unique expression pattern