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Search Results: 1 - 10 of 716 matches for " Maser Edmund "
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16th Carbonyl Metabolism Meeting: from enzymology to genomics
Maser Edmund
Human Genomics , 2012, DOI: 10.1186/1479-7364-6-25
Abstract: The 16th International Meeting on the Enzymology and Molecular Biology of Carbonyl Metabolism, Castle of Ploen (Schleswig-Holstein, Germany), July 10–15, 2012, covered all aspects of NAD(P)-dependent oxido-reductases that are involved in the general metabolism of xenobiotic and physiological carbonyl compounds. Starting 30 years ago with enzyme purification, structure elucidation and enzyme kinetics, the Carbonyl Society members have meanwhile established internationally recognized enzyme nomenclature systems and now consider aspects of enzyme genomics and enzyme evolution along with their roles in diseases. The 16th international meeting included lectures from international speakers from all over the world.
Green Tea and One of Its Constituents, Epigallocatechine-3-gallate, Are Potent Inhibitors of Human 11β-hydroxysteroid Dehydrogenase Type 1
Jan Hintzpeter, Claudia Stapelfeld, Christine Loerz, Hans-Joerg Martin, Edmund Maser
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0084468
Abstract: The microsomal enzyme 11β-hydroxysteroid deydrogenase type 1 (11β-HSD1) catalyzes the interconversion of glucocorticoid receptor-inert cortisone to receptor- active cortisol, thereby acting as an intracellular switch for regulating the access of glucocorticoid hormones to the glucocorticoid receptor. There is strong evidence for an important aetiological role of 11β-HSD1 in various metabolic disorders including insulin resistance, diabetes type 2, hypertension, dyslipidemia and obesity. Hence, modulation of 11β-HSD1 activity with selective inhibitors is being pursued as a new therapeutic approach for the treatment of the metabolic syndrome. Since tea has been associated with health benefits for thousands of years, we sought to elucidate the active principle in tea with regard to diabetes type 2 prevention. Several teas and tea specific polyphenolic compounds were tested for their possible inhibition of cortisone reduction with human liver microsomes and purified human 11β-HSD1. Indeed we found that tea extracts inhibited 11β-HSD1 mediated cortisone reduction, where green tea exhibited the highest inhibitory potency with an IC50 value of 3.749 mg dried tea leaves per ml. Consequently, major polyphenolic compounds from green tea, in particular catechins were tested with the same systems. (?)-Epigallocatechin gallate (EGCG) revealed the highest inhibition of 11β-HSD1 activity (reduction: IC50 = 57.99 μM; oxidation: IC50 = 131.2 μM). Detailed kinetic studies indicate a direct competition mode of EGCG, with substrate and/or cofactor binding. Inhibition constants of EGCG on cortisone reduction were Ki = 22.68 μM for microsomes and Ki = 18.74 μM for purified 11β-HSD1. In silicio docking studies support the view that EGCG binds directly to the active site of 11β-HSD1 by forming a hydrogen bond with Lys187 of the catalytic triade. Our study is the first to provide evidence that the health benefits of green tea and its polyphenolic compounds may be attributed to an inhibition of the cortisol producing enzyme 11β-HSD1.
Structural Basis for Substrate Specificity in Human Monomeric Carbonyl Reductases
Ewa S. Pilka,Frank H. Niesen,Wen Hwa Lee,Yasser El-Hawari,James E. Dunford,Grazyna Kochan,Vladimir Wsol,Hans-Joerg Martin,Edmund Maser,Udo Oppermann
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0007113
Abstract: 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.
Toxicity of Functional Nano-Micro Zinc Oxide Tetrapods: Impact of Cell Culture Conditions, Cellular Age and Material Properties
Heike Papavlassopoulos, Yogendra K. Mishra, S?ren Kaps, Ingo Paulowicz, Ramzy Abdelaziz, Mady Elbahri, Edmund Maser, Rainer Adelung, Claudia R?hl
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0084983
Abstract: With increasing production and applications of nanostructured zinc oxide, e.g., for biomedical and consumer products, the question of safety is getting more and more important. Different morphologies of zinc oxide structures have been synthesized and accordingly investigated. In this study, we have particularly focused on nano-micro ZnO tetrapods (ZnO-T), because their large scale fabrication has been made possible by a newly introduced flame transport synthesis approach which will probably lead to several new applications. Moreover, ZnO-T provide a completely different morphology then classical spherical ZnO nanoparticles. To get a better understanding of parameters that affect the interactions between ZnO-T and mammalian cells, and thus their biocompatibility, we have examined the impact of cell culture conditions as well as of material properties on cytotoxicity. Our results demonstrate that the cell density of fibroblasts in culture along with their age, i.e., the number of preceding cell divisions, strongly affect the cytotoxic potency of ZnO-T. Concerning the material properties, the toxic potency of ZnO-T is found to be significantly lower than that of spherical ZnO nanoparticles. Furthermore, the morphology of the ZnO-T influenced cellular toxicity in contrast to surface charges modified by UV illumination or O2 treatment and to the material age. Finally, we have observed that direct contact between tetrapods and cells increases their toxicity compared to transwell culture models which allow only an indirect effect via released zinc ions. The results reveal several parameters that can be of importance for the assessment of ZnO-T toxicity in cell cultures and for particle development.
Use of Malaria Rapid Diagnostic Tests among Medical Doctors in a Tertiary Hospital, South East Nigeria  [PDF]
Edmund O. Ndibuagu
Health (Health) , 2018, DOI: 10.4236/health.2018.107072
Abstract: Malaria is a major health problem in Nigeria that has as high as 25% of all global cases, and 30% of deaths attributable to malaria. In 2010, World Health Organization (WHO) recommended universal confirmation of diagnosis of malaria through blood parasitological test, prior to initiation of treatment. In addition to Microscopy, Malaria Rapid diagnostic Tests (mRDTs) are blood tests for malaria. Early diagnosis of malaria ensures that the correct treatment is commenced in good time, and this subsequently improves the prognosis. The objective of this study is to assess the use of mRDTs among medical doctors working in a tertiary hospital, Southeast Nigeria. This study was conducted in Enugu State Teaching hospital, Southeast Nigeria. The study was of cross-sectional design, and conducted in October 2016 among medical doctors working in the General Outpatient, Internal Medicine, and Paediatrics departments of the Teaching hospital. Statistical Package for Social Sciences (SPSS) version 20.0 was used for data analysis. A total of 86 medical doctors, out of the eligible 91 in the three departments participated in the study, and were distributed as follows; 24 (27.9%) in the General Outpatient, 30 (34.9%) in the Internal Medicine, and 32 (37.2%) in the Paediatrics departments. More medical doctors in the Paediatrics department (31.3%) used mRDTs in making diagnosis of malaria, followed by Internal medicine (13.3%), then General Outpatient Department (8.3%). Malaria rapid diagnostic tests are cost-effective, and useful tools in malaria control and elimination programmes. If tangible progress on the implementation of the WHO guidelines on confirming diagnosis of malaria before treatment; and the T3: Test, Treat, Track initiative is to be made; then the government and the Management of hospitals ought to take more determined efforts aimed at educating and informing health workers, especially medical doctors on the benefits of mRDTs.
Formal Education Related Pattern of Awareness and Basic Knowledge on Zika Virus Disease, among Women Visiting Children Immunization Unit in a Tertiary Hospital, Southeast Nigeria  [PDF]
Edmund O. Ndibuagu
Health (Health) , 2018, DOI: 10.4236/health.2018.1011119
Abstract: Zika virus is transmitted through the bite of infected Aedesa egypti, or Aedes albopictus mosquito, and re-emerged as a disease of global public health importance in March/April 2015 in Brazil. The objective of this study is to assess the formal education related pattern of awareness, and basic knowledge on Zika virus disease, among women visiting children immunization unit in a tertiary hospital, in Nigeria. Study was conducted in 2016/2017 with 256 randomly selected respondents. Semi-structured questionnaire was used in the cross-sectional study. Findings including 77.8% of respondents with postgraduate educational qualification were aware that there is a disease known as Zika Virus Disease (ZVD), 62.0% for tertiary education qualification, 53.8% for secondary education level, 20.0% for primary education level, while none of the three respondents that had no formal education were aware of ZVD. The level of awareness increased with increasing educational qualification. These findings were analyzed using the Likelihood Ratio which was calculated to be 28.329, with P-value of <0.001. Television was the commonest source of first ZVD information. Overall mean percentage knowledge level of the different educational groups revealed as followed; no formal education 22.2%, primary level 12.0%, secondary level 46.1%, tertiary level 54.4%, and postgraduate level was 51.5%. The mean for the stated scores was 37.2%. Students’ T-Test at 95.0% confidence interval was 0.012, showing that the difference in the mean percentage scores between the groups was significant. Respondents with tertiary and postgraduate education qualifications recorded overall mean score above 50.0% each, while secondary, primary, and no formal education groups recorded overall mean percentage scores below 50.0%. Stepping up ZVD health education and awareness activities, especially among women with educational qualification below tertiary level will greatly improve the awareness and knowledge on ZVD among this study population.
Characterization of sugar diversity in floral and extra-floral nectar from the Coastal Coral Tree (Erythrina caffra Thunb.) in Southern California  [PDF]
V?ctor D. Carmona-Galindo, Kenny Morales, Renee Maser, Julius Doyle, Mera Gobrial
Open Journal of Ecology (OJE) , 2014, DOI: 10.4236/oje.2014.42003
Abstract:

The Coastal Coral Tree (Erythrina caffra Thunb.) produces floral nectar (FN) that serves to attract pollinating insects, but also secretes nectar from extra-floral (EFN) glands that serves to attract predatory insects, such as ants. While studies on myrmecophytes (i.e. specialized plants that attract and interact with ants) have primarily focused on interspecific evaluations of EFN chemistry, the Coastal Coral tree offers an opportunity to contrast intraspecific nectar chemistry with differing evolutionary and ecological functions. We hypothesized that the richness of (molecular) sugar species, relative concentrations, and diversity of sugars in FN and foliar EFN would diverge due to differences in the ecological role of the two types of nectar. High performance liquid chromatography with refractive index detection was used to identify the richness of sugar species (based on retention time), measure the relative concentrations, and evaluate the diversity of sugars in FN and foliar EFN secretions. We detected sugar species unique to each gland type and reported significant differences in the relative concentration of one sugar species common to both gland types. While the mean diversity index of sugars was similar for both gland types, the diversity of foliar EFN sugars was significantly more variable than that of FN sugars. The composition of FN showed little variation, and was reflective of its fundamental role in plant reproduction. Foliar EFN, however, demonstrated the variability expected of a context-dependent myrmecophyte that interacts with a facultative ant species assemblage across a mosaic of abiotic and biotic conditions.

Austrid, suitsul he ja Stiltoni juust
Edmund Leach
M?etagused. Hüperajakiri , 2012,
Abstract: French anthropologist, ethnologist and myth researcher Claude Lévi-Strauss adopted from linguistics the structuralist model and cause an epistemological revolution in anthropolgy. His works have proved most influential in the fields of studying kinship relations, classifications and mythology, but also general understanding of history, culture and thinking. Lévi-Strauss believes that the basic characteristics of human nature remain the same in all cultures, while great civilisations emerge as a result of synergy between cultures. His structuralist theory is analysed and commented by the British social anthropologist Edmund Leach.
A ingenuidade da ciência
Edmund Husserl
Scientiae Studia , 2009, DOI: 10.1590/s1678-31662009000400008
Abstract:
Primary Colours’
Edmund Thomas
Journal of Art Historiography , 2011,
Abstract: Review of: Mark Bradley, Colour and Meaning in Ancient Rome, Cambridge and New York: Cambridge University Press, 2009. This article reviews Mark Bradley’s monograph Colour and Meaning in Ancient Rome, Cambridge: Cambridge University Press, 2009. This book is the first major study in English of the conceptual history of colour in ancient Rome. It re-examines a range of Latin philosophical, rhetorical and literary texts, focusing on the period of the late Republic and early Empire. The work considers Roman attempts to understand the colours of the rainbow and assimilates the role of metaphorical colour in rhetorical presentation to the addition of colour through cosmetics. It ends with a consideration of the colours of the Roman triumph in comparison with modern ceremony. The book will be useful for philologists, philosophers and historians and is accessible to students. Its conclusion is that colour was a negotiable concept, leading to the confusion of appearance and reality, a conclusion which applies particularly to the specific historical and cultural context of Neronian Rome. The book raises the further issue of how these theoretical principles were applied to the interpretation of visual evidence, as well as wider uses of colour in social and religious contexts.
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