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Structural Part (structural + part)
Selected AbstractsMutation analysis in mitochondrial fatty acid oxidation defects: Exemplified by acyl-CoA dehydrogenase deficiencies, with special focus on genotype,phenotype relationshipHUMAN MUTATION, Issue 3 2001Niels Gregersen Abstract Mutation analysis of metabolic disorders, such as the fatty acid oxidation defects, offers an additional, and often superior, tool for specific diagnosis compared to traditional enzymatic assays. With the advancement of the structural part of the Human Genome Project and the creation of mutation databases, procedures for convenient and reliable genetic analyses are being developed. The most straightforward application of mutation analysis is to specific diagnoses in suspected patients, particularly in the context of family studies and for prenatal/preimplantation analysis. In addition, from these practical uses emerges the possibility to study genotype,phenotype relationships and investigate the molecular pathogenesis resulting from specific mutations or groups of mutations. In the present review we summarize current knowledge regarding genotype,phenotype relationships in three disorders of mitochondrial fatty acid oxidation: very-long chain acyl-CoA dehydrogenase (VLCAD, also ACADVL), medium-chain acyl-CoA dehydrogenase (MCAD, also ACADM), and short-chain acyl-CoA dehydrogenase (SCAD, also ACADS) deficiencies. On the basis of this knowledge we discuss current understanding of the structural implications of mutation type, as well as the modulating effect of the mitochondrial protein quality control systems, composed of molecular chaperones and intracellular proteases. We propose that the unraveling of the genetic and cellular determinants of the modulating effects of protein quality control systems may help to assess the balance between genetic and environmental factors in the clinical expression of a given mutation. The realization that the effect of the monogene, such as disease-causing mutations in the VLCAD, MCAD, and SCAD genes, may be modified by variations in other genes presages the need for profile analyses of additional genetic variations. The rapid development of mutation detection systems, such as the chip technologies, makes such profile analyses feasible. However, it remains to be seen to what extent mutation analysis will be used for diagnosis of fatty acid oxidation defects and other metabolic disorders. Hum Mutat 18:169,189, 2001. © 2001 Wiley-Liss, Inc. [source] Role of surface promoter mutations in hepatitis B surface antigen production and secretion in occult hepatitis B virus infection,JOURNAL OF MEDICAL VIROLOGY, Issue 3 2007Sonali Sengupta Abstract The production, secretion, and localization of surface proteins of hepatitis B virus (HBV) and the ratio of large to small surface protein S was studied in HepG2 cells transfected with the wild-type and mutant pre-S1 and pre-S2/S promoters of HBV molecular clones 313.1 (GenBank accession no. AY161147) and 761.1 (GenBank accession no. AY161159) from two patients with occult HBV infection. Fusion constructs were made by in frame fusion of the wild-type surface gene to the mutant pre-S1 and pre-S2/S promoters and wild-type promoter so that the structural part of the small surface protein remains identical. HepG2 cells transfected transiently were used for analysis. HBV surface proteins production and secretion was determined by enzyme linked immuno assay (ELISA) and localization by immunofluorescence. Immunoprecipitation of the large, middle, and small surface protein was carried out in transient transfected and metabolically labeled cells to determine the ratio of the large to small surface protein. The results indicate that HepG2 cells transfected with mutant HBV promoters had reduced HBV surface proteins secretion compared to wild-type HBV. HepG2 cells transfected with mutant HBV pre-S1 and pre-S2/S promoters showed cytoplasmic aggregation of HBV surface proteins compared to wild-type HBV promoters, which showed diffuse cytoplasmic localization. In all cases, the HBV surface proteins localized to the endoplasmic reticulum. The ratio between the large and small surface protein was 1.89 and 0.56 with mutant HBV 313.1 and 761.1 pre-S1 and pre-S2/S promoters, respectively, compared to 0.17 in wild-type. Thus, the aggregation of surface proteins, altered ratio and secretion of surface proteins were possibly the causes of occult hepatitis B infection. J. Med. Virol. 79:220,228, 2007. © 2007 Wiley-Liss, Inc. [source] Polymers with benzofuro-benzofuran structures,POLYMER INTERNATIONAL, Issue 10 2002Behzad Pourabas Abstract Several kinds of molecules and also polymers are going to be discussed in the present article. Common feature in these molecules and polymers is the possessing of a specific structural part, namely benzofuro,benzofuran. This structure will appear in several molecules and kinds of polymers in the text. A condensation reaction between glyoxal and phenols is the reaction needed to produce the mentioned structural part, ie benzofuro,benzofuran. Because of the importance of this reaction, a brief historical background in the initial section of the article, and some discussion on the structural assignment of the reaction product and the reaction mechanism is also given in sections later on. Types of polymers, which are discussed in this article, are mainly heat stable polymers including polyamide, poly(ether ketone sulfone), polybenzimidazole, poly(amide-benzimidazole) and polyarylates. Polyester, polyhaydrezide and polymers with NLO property are the other kinds of the discussed polymers in the text with the benzofuro,benzofuran structure in their main chain. There is not any detailed procedure provided in the text about the synthesis of the molecules or even the polymers and the general procedures provided follow only the methodological purposes of the authors. Thermal properties of the polymers are discussed in the final section of the article with an attempt to provide a comparative argument in order to reach a relationship between structure and thermal properties. © 2001 Society of Chemical Industry. [source] A THEORY OF MAN AS A CREATOR OF THE WORLD,THE JAPANESE ECONOMIC REVIEW, Issue 1 2008AKIHIKO MATSUIArticle first published online: 14 FEB 200 The present paper proposes a theory of man, wherein man constructs models of the world based on past experiences in social situations. The present theory considers experiences, or chunks of impressions, as primitives instead of an objective game, which is assumed to be given in the standard game theory. Agents construct models of the world based on direct and indirect experiences. Each model comprises a structural part and a factual part. The structural part is represented as a game, while the factual part is represented as a strategy profile of this game. In constructing a model, an agent might use certain axioms,for example coherence, according to which the model should be able to explain his or her own experiences; conformity to a solution concept; and minimality with respect to some simplicity measure. A few applications are presented to demonstrate how this theory works. [source] Posidonia oceanica as a biomonitor of trace elements in the gulf of naples: Temporal trends by lepidochronology,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2004Stefania Ancora Abstract Levels of Hg, Cd, Pb, Cu, Zn, Fe, and Mn were assessed by using Posidonia oceanica as a bioindicator in the Gulf of Naples (southern Italy). Lepidochronology, which enables retroactive dating of scales and rhizomes of this seagrass, was combined with atomic spectrometry to assess temporal trends of trace elements in dated scales and rhizomes over a 10-year period. Lepidochronology occasionally has been used to monitor Hg in dated scales, but never has been used to determine concentrations of other trace elements in dated rhizomes. Data were compared between various structural parts of seagrass and between sampling sites. Concentrations of some elements found in dated scales or rhizomes showed a similar trend in most of the sites; increasing for Hg and Cu and decreasing for Pb, Fe, and Zn. Contaminant levels indicated by seagrass meadows varied from metal to metal. Concentrations of Hg, Cd, and Pb fell within the ranges measured in other areas considered to have low levels of heavy metal pollution, whereas Cu, Mn, and Zn had higher concentrations only in some years. However, on the basis of other studies, none of the sampling sites are considered to have high contamination levels. [source] Glycerol and Glycerol Glycol GlycodendrimersEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 22 2003Mike M. K. Boysen Abstract Non-covalent interactions between structural parts of complex oligosaccharides and saccharide-recognising proteins are of crucial importance for many cell communication phenomena. Specificity of such interactions and stability of these ligand-receptor complexes are achieved through multivalent interactions between multiple copies of a saccharide ligand and a corresponding number of protein receptors. Substances presenting multiple copies of the saccharide ligand on easily accessible scaffold molecules therefore appear to be promising tools for study of multivalent interactions and their possible inhibition. Such multivalent glycomimetics can be prepared by attachment of saccharide residues to the surface functional groups of dendrimers. In the course of our work, we have prepared novel glycodendrimers with glycerol and glycerol glycol polyether scaffolds. Isopropylidene-protected hydroxyethyl mannoside was chosen as the carbohydrate component, with the construction of the dendritic structures proceeding by a convergent approach featuring iterative Williamson etherification and ozonolysis/hydride reduction steps. Deprotected representatives of such structures are potential inhibitors of mannose-binding lectins of E. coli. Three representative compounds were deprotected and their anti-adhesive properties were examined. The route to these glycodendrimers was also evaluated in terms of synthetic chemistry. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] | ||||||||||