Thesis (M.Sc.)--York University, 2009. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 108-139). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR51542

Bochum, Univ., Diss., 2003. / Computerdatei im Fernzugriff.

Regensburg, Univ., Diss., 2008.

Thesis (Ph. D.)--University of Louisville, 2004. / Department of Pharmacology and Toxicology. Vita. "August 2004." Includes bibliographical references (leaves 124-142).

University, Diss., 2006--Würzburg.

Bochum, Universiẗat, Diss., 2003.

Proefschrift Universiteit van Amsterdam. / Omslagtitel. Met lit.opg.

Made available in DSpace on 2015-12-06T22:54:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2009 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O presente estudo teve como objetivo determinar as β)lactamases envolvidas na resistência às cefalosporinas de amplo espectro em uma coleção de Pseudomonas aeruginosa isoladas de hemoculturas de pacientes internados em um complexo hospitalar universitário na cidade de São Paulo durante o ano de 2005. No primeiro trabalho descrevemos a produção de CTX)M)2 em um isolado que apresentava o estranho fenótipo de sensibilidade à ceftazidima e resistência à cefepima. O gene que codificava esta enzima estava localizado no cromossomo bacteriano, em um contexto genético idêntico àquele encontrado em plasmídeos que carregam blaCTX)M)2, que encontram)se disseminados entre enterobactérias. No segundo trabalho, descrevemos as β)lactamases envolvidas na resistência à ceftazidima em 43 isolados de P. aeruginosa da referida coleção, assim como o contexto e suporte no qual estavam inseridos os genes que codificavam as enzimas identificadas. Além disso, realizamos a tipagem molecular dos isolados estudados e pesquisamos os prontuários médicos dos pacientes infectados pelas amostras estudadas. A hiperprodução de AmpC foi considerada a única β)lactamase relacionada à resistência a ceftazidima em quatro isolados (9,3 por cento). Nove isolados (20,9 por cento) apresentaram a produção de β)lactamase de espectro estendido (ESBL), sendo que sete (16,3 por cento) apresentavam a enzima GES)1 e dois isolados (4,6 por cento) apresentavam a enzima CTX)M)2. A atividade hidrolítica contra os carbapenens foi detectada em trinta isolados (69,7 por cento), nos quais as enzimas IMP)1, GES) 5 e SPM)1 foram identificadas em 1, 2 e 27 isolados, respectivamente. Nenhum isolado apresentou produção simultânea de metalo)β)lactamase e ESBL. Os genes blaSPM)1 e blaCTX)M)2 estavam associados às seqüências de inserção ISCR4 e ISCR1, respectivamente, enquanto que os genes blaGES)1, blaGES)5 e blaIMP)1 estavam localizados em integrons da classe 1. Todos os genes codificadores de β)lactamases identificados apresentavam localização cromossomal. A tipagem molecular dos isolados estudados evidenciou a existência de sete genótipos distintos; porém, isolados produtores de uma mesma enzima freqüentemente apresentavam relação clonal. A análise dos prontuários médicos revelou que metade dos pacientes que apresentaram infecção da corrente sanguínea pelos isolados de P. aeruginosa estudados receberam terapia inadequada. Este estudo permitiu identificar a diversidade de genes codificadores de β)lactamases de amplo espectro hidrolítico que foram adquiridos por isolados clínicos de P. aeruginosa. Estes genes foram inseridos no DNA cromossomal destes isolados e, posteriormente, disseminados por transmissão cruzada.. / The aim of this study was to identify the β-lactamases involved in broad-spectrum cephalosporin resistance in P. aeruginosa isolates recovered from blood culture of patients hospitalized at a Brazilian teaching hospital located in São Paulo, between January and December 2005. In the first manuscript we have described the production of CTX-M-2 causing ceftazidime susceptibility and cefepime resistance in a P. aeruginosa clinical isolate. The CTX-M-2-encoding gene was located at the bacterial chromosome, and its vicinities were identical to those observed in blaCTX-M-2-carrying plasmids from enterobacterial isolates. In the second manuscript we have evaluated 43 ceftazidime-resistant P. aeruginosa isolates from the referred collection. We have described the β-lactamases involved in ceftazdidme resistance, as well as the genetic context and support of β-lactamaseencoding genes and we have performed molecular typing of isolates. The medical records of patients infected with isolates studied were also analyzed. AmpC overproduction was found to be the only β-lactamase-mediated mechanism responsible for ceftazidime resistance in four isolates (9.3%). Nine isolates (20.9%) produced an extended-spectrum β-lactamase (ESBL), either GES-1 (n = 7, 16.3%) or CTX-M-2 (n = 2, 4.6%). Carbapenemase activity was detected in 30 (69,7%) isolates, in which two (4.6%) produced the ESBL GES-5, a single isolate (2.3%) produced the metallo-β-lactamase (MBL) IMP-1; and 27 isolates produced the MBL SPM-1 (62.8%). None of the isolates coproduced both ESBL and MBL. Insertion sequence elements ISCR4 and ISCR1 were associated with blaSPM-1 and blaCTX-M-2 genes, respectively, whereas the blaGES and blaIMP-1 genes were part of class 1 integron structures. All β- lactamase-encoding genes identified were chromosomally located. Molecular typing showed the existence of seven distinct genotypes, in which producers of the same β- lactamase often belonged to a single clone. Clinical data revealed that half of the patients infected with isolates studied have received inadequate therapy, suggesting that empirical treatment protocols should be updated in the hospital studied. In this study we have identified a variety of broad-spectrum β-lactamase-encoding genes that have been initially acquired by P. aeruginosa clinical isolates, inserted on its chromosomal DNA and then spread between patients by cross-transmition. / BV UNIFESP: Teses e dissertações

Since the enantiomers of a number of racemic drugs have been found to have different activities or modes of action, enantioselective analysis is becoming more important. A number of different approaches to chromatographic chiral resolutions have been evaluated for their ability to resolve the enantiomers of racemic beta blocking drugs, Three chiral HPLC columns were investigated; a cyclodextrin phase, an (R)-3,5-dinitrabezoylphenylglycine phase and a protein phase. The acid glycoprotein phase successfully resolved atenolol, alprenolol, metoprolol, oxprenolol, propranolol and verapamil with 0.01M phosphate buffer eluents modified with either acetonitrile or isopropanol. The (R)-3,5-dinitrobenzoylphenylglycine phase was used with eluents of Isopropanol in hexane and resolutions of propranolol, oxprenolol, metoprolol, alprenolol and pronethalol were achieved after formation of the 1- or 2-naphthamide derivatives, although no separations were achieved for the underivatised samples. The cyclodextrin phase was also found to be unsuccessful in resolving underivatised samples of propranolol and verapamil. However preliminary results indicate that resolutions are possible after the formation of their trifluoroacetyl derivatives. The cyclodextrin phase was also successfully used to resolve the enantiomers of chlorpheniramine and the geometric isomers of clomiphene. In addition to the chiral HPLC stationary phases, a (+)-10-camphorsulphonic acid mobile phase additive was investigated, although this was found to be completely unsuccessful. Finally the use of a chiral diamide GLC column was investigated. This was not suited to the analysis of beta blockers, even after derivatisation, although derivatised amino acids were well resolved. The use of computer modelling to predict the degree of separation of enantlomers was also investigated for the (R)-3,5-dinitrabenzoyl phenylglycine phase, with the interaction energies between the phase and both isomers of each compound calculated for the most stable conformation. From a comparison with the experimental results, it was shown that this approach to prediction was unsuccessful.

The aim of this thesis was to determine the variability of the quantity of non-starch polysaccharides in grain malting spring barley (Bojos, Kangoo, Laudis 550, Malz, Sebastian Xanadu), winter barley (Wintmalt) non- malting varieties of winter barley (Jup, Lester, Nero), spring barley (Azita, Tocada, Wiebke) and food suitable varieties spring barley (Cesar AF, AF Lucius). Samples of barley grains were detected on the quantity of pentosans and beta-glucans. Pentosans were determined by the Douglas method. Beta-glucan content in grain by FIA (Flow Injection Analysis). The influence factors on the content of pentosans and beta-glucans between varieties have been tested at the 5% level of conclusiveness. The quantity of pentosanes in the grain was in the range from 2.28 to 5.95%. The lowest content of pentosans was found in malting varieties of spring barley Sebastian, the highest content by winter barley varieties Nero. The range of beta-glucan varied from 4.01 to 6.69%. The lowest content of beta-glucan was found in malting varieties of winter barley Wintmalt the highest in nutritionally appropriate to varieties of spring barley AF Cesar.