Thesis (M.Med.Sc.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 33-36). Also available in print.

Submitted by Aline Chiodi Borges null (aline.borges@ict.unesp.br) on 2017-02-01T12:59:00Z No. of bitstreams: 1 TESE Aline Chiodi Borges.pdf: 2538445 bytes, checksum: b94b3366c29227ee5a2e026711c63088 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-02-03T19:27:38Z (GMT) No. of bitstreams: 1 borges_ac_dr_sjc.pdf: 2538445 bytes, checksum: b94b3366c29227ee5a2e026711c63088 (MD5) / Made available in DSpace on 2017-02-03T19:27:38Z (GMT). No. of bitstreams: 1 borges_ac_dr_sjc.pdf: 2538445 bytes, checksum: b94b3366c29227ee5a2e026711c63088 (MD5) Previous issue date: 2016-12-15 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As doenças fúngicas representam grande desafio para a área médica e odontológica devido à crescente prevalência e aumento da resistência aos antifúngicos. O plasma frio sob pressão atmosférica (PFPA) é uma mistura gasosa contendo partículas carregadas, radicais livres e radiação. Sua potencial aplicação em doenças infecciosas foi relatada, contudo a literatura carece de estudo sistemático sobre o efeito antifúngico, mecanismos de ação e potencial citotóxico. Neste trabalho foi avaliado o efeito antifúngico do PFPA sobre Candida albicans através de ensaios em células planctônicas e biofilmes, efeitos sobre a integridade de parede celular e membrana plasmática, morfogênese, produção de exoenzimas, aderência às células epiteliais e efeito no tratamento in vivo de lesões de candidose oral induzida em modelo murino. Ainda, avaliou-se o efeito do PFPA sobre culturas de Trichophyton rubrum, além de efeitos sobre capacidade de adesão de conídios. Ainda, o potencial citotóxico foi investigado usando células epiteliais. PFPA em modo de tensão contínuo (MC) foi capaz de reduzir a aderência de C. albicans às células epiteliais, modular a transição levedura-hifa na cepa SC 5314 e comprometer a viabilidade de biofilmes. PFPA-MC se mostrou citotóxico em parâmetros efetivos frente a biofilmes de C. albicans. Porém, não foi observado efeito citotóxico quando o PFPA foi utilizado em modo de tensão pulsada (MP). A exposição ao PFPA-MP reduziu a invasão de C. albicans no epitélio in vivo. O PFPA-MP foi capaz de afetar o crescimento de T. rubrum a partir de 10 minutos e de afetar a sua capacidade de aderência. Assim, conclui-se que PFPA apresenta efeito antifúngico contra C. albicans e T. rubrum e é capaz de interferir em fatores de virulência de ambos os micro-organismos. / Fungal diseases represent a great challenge to the medical and dental areas, due to the increasing prevalence and antifungal resistance. Atmospheric pressure plasma jet (APPJ) is a gaseous mixture containing charged particles, free radicals and radiation. Its potential application in infectious disease has been reported, however there is still a lack of a systematic study on the antifungal effect, mechanism of action and citotoxicc potential. The general aim of this project was to evaluate the antifungal effect of APPJ on Candida albicans in planktonic and biofilm cultures, effects on cell wall and cell membrane integrity, morphogenesis, exoenzymes production, adherence to epithelial cells and in vivo effect in the treatment of oral candidosis in murine model will be performed. The effect of APPJ on Trichophyton rubrum cultures and on adherence capability were also evaluated. The cytotoxic potential was evaluated in vitro. APPJ in continuous tension mode (CM) was able to reduce the adherence and yeast-hyphae transition in C. albicans SC 5314 and to decrease biofilm viability. APPJ-CM showed cytotoxic effect in the parameters effective to C. albicans biofilm. Conversely, no cytotoxic effect on epithelial cells were observed when pulsed (PM) plasma jet was used. In vivo tests showed that APPJ-PM was able to prevent C. albicans invasion to the epithelium. T. rubrum cultures were affectd by APPJ-PM after 15 minutes of exposure and conidia adherence was impaired by 10 minutes exposure. In conclusion, APPJ showed antifungal effect against C. albicans and T. rubrum and can also impair virulence factors in both microorganisms. / FAPESP: 2014/02354-7

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

No description available.

Thesis (Ph.D.)--McMaster University, 2006. / Supervisor: G.D. Wright. Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:32:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-26Bitstream added on 2014-06-13T18:43:05Z : No. of bitstreams: 1 silva_hr_dr_arafcf.pdf: 2348065 bytes, checksum: c63f75a77b4cb78f5b87a6170be20a8f (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / Nas últimas décadas, tem ocorrido um aumento expressivo na incidência de infecções fúngicas. Por outro lado, o tratamento das micoses nem sempre é efetivo, pois os fármacos antifúngicos disponíveis apresentam espectro de atividade e perfil farmacocinético inadequados, em especial no tratamento das lesões cutâneas. Portanto, o objetivo do presente trabalho foi desenvolver e caracterizar sistemas nanoestruturados estabilizados com álcool cetílico etoxilado 20 OE e propoxilado 5 OP (PROC) contendo fluconazol (FLU), empregando ácido oléico (AO) e óleo de copaíba como fases oleosas. A caracterização química, seguida de ensaios biológicos, dos óleos de copaíba de diferentes fontes, foi determinante para a escolha do óleo a ser usado no desenvolvimento das formulações. A construção de diagramas de fases com ambos os óleos mostrou que diferentes sistemas como microemulsões (ME) e cristais líquidos (CL) podem ser formados. A caracterização físico-química (MLP, SAXS e Reologia) mostrou que na região de 40% de PROC, o aumento da quantidade de água favorece a formação de sistemas mais estruturados como CL de fase lamelar e hexagonal quando se utiliza AO e óleo de copaíba... / In the last decades, there has been an expressive increase in incidence of fungal infections. On the other hand, the treatment of mycoses is not always effective, because available antifungal drugs show inappropriate activity spectrum and pharmacokinetic profile. The aim of this work was to develop and characterize nanostructured systems stabilized by propoxyl (5OP) ethoxyl (20 OE) cethyl alcohol (PROC) containing fluconazole, using oleic acid and copaiba oil from different origins as oily phases. Chemical and biological characterization of copaiba oils from different origins was decisive for the choice of oil to be used in the development of the formulations. The construction of phase diagrams with studied copaiba oils showed that different systems such as microemulsions (ME) and liquid crystals (CL) can be formed. The characterization by polarized light microscopy, rheological behavior and SAXS confirmed the results obtained in phase diagrams, showing that in the region of 40% of PROC, the increase in the quantity of water favors the formation of more structured systems as CL of lamellar and hexagonal phase... (Complete abstract click electronic access below)

Resumo: Nas últimas décadas, tem ocorrido um aumento expressivo na incidência de infecções fúngicas. Por outro lado, o tratamento das micoses nem sempre é efetivo, pois os fármacos antifúngicos disponíveis apresentam espectro de atividade e perfil farmacocinético inadequados, em especial no tratamento das lesões cutâneas. Portanto, o objetivo do presente trabalho foi desenvolver e caracterizar sistemas nanoestruturados estabilizados com álcool cetílico etoxilado 20 OE e propoxilado 5 OP (PROC) contendo fluconazol (FLU), empregando ácido oléico (AO) e óleo de copaíba como fases oleosas. A caracterização química, seguida de ensaios biológicos, dos óleos de copaíba de diferentes fontes, foi determinante para a escolha do óleo a ser usado no desenvolvimento das formulações. A construção de diagramas de fases com ambos os óleos mostrou que diferentes sistemas como microemulsões (ME) e cristais líquidos (CL) podem ser formados. A caracterização físico-química (MLP, SAXS e Reologia) mostrou que na região de 40% de PROC, o aumento da quantidade de água favorece a formação de sistemas mais estruturados como CL de fase lamelar e hexagonal quando se utiliza AO e óleo de copaíba... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the last decades, there has been an expressive increase in incidence of fungal infections. On the other hand, the treatment of mycoses is not always effective, because available antifungal drugs show inappropriate activity spectrum and pharmacokinetic profile. The aim of this work was to develop and characterize nanostructured systems stabilized by propoxyl (5OP) ethoxyl (20 OE) cethyl alcohol (PROC) containing fluconazole, using oleic acid and copaiba oil from different origins as oily phases. Chemical and biological characterization of copaiba oils from different origins was decisive for the choice of oil to be used in the development of the formulations. The construction of phase diagrams with studied copaiba oils showed that different systems such as microemulsions (ME) and liquid crystals (CL) can be formed. The characterization by polarized light microscopy, rheological behavior and SAXS confirmed the results obtained in phase diagrams, showing that in the region of 40% of PROC, the increase in the quantity of water favors the formation of more structured systems as CL of lamellar and hexagonal phase... (Complete abstract click electronic access below) / Orientador: Maria Palmira Daflon Gremião / Coorientador: Georgino Honorato de Oliveira / Banca: Nereide Stela Santos Magalhães / Banca: Marlus Chorilli / Banca: Silvia Stanisçuaski Guterres / Banca: Renata Fonseca Vianna Lopez / Doutor

Orientador: Plínio Trabasso / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T11:49:19Z (GMT). No. of bitstreams: 1 Souza_Marcelade_M.pdf: 1154397 bytes, checksum: c435b972ac36d284080e07e6b6b20a6e (MD5) Previous issue date: 2014 / Resumo: Este trabalho teve por objetivo comparar o desempenho das técnicas de microarranjo de DNA (DNA microarray), amplificação circular isotérmica (Loop mediated isothermal amplification (LAMP)), PCR em tempo real e sequenciamento de DNA para a identificação das espécies de Fusarium, agentes de infecção da corrente sanguínea, isolados de pacientes com doenças onco-hematológicas do Hospital de Clínicas da Universidade Estadual de Campinas (HC-Unicamp) e do Hospital de Clínicas da Faculdade de Medicina da Universidade de São Paulo (FMUSP) em um estudo de corte retrospectivo. Foram selecionados 21 amostras de Fusarium isoladas de sangue, sendo 17 amostras da micoteca do Laboratório de Investigação em Fungos (LIF) da Faculdade de Ciências Médicas da Unicamp (FCM-Unicamp) e três amostras da micoteca do Laboratório de Microbiologia da FMUSP. As metodologias de DNA microarray, LAMP e PCR em tempo real, identificaram 17 das 21 amostras como complexo Fusarium solani e quatro como complexo Fusarium não - solani, apresentando um alto desempenho, uma concordância de 100% entre elas e uma sensibilidade de 100% para as metodologias DNA microarray, LAMP e PCR em tempo real e uma especificidade de 100% para a metodologia de LAMP. Esses dados foram validados pela metodologia de sequenciamento de DNA, a qual identificou 17 amostras como complexo Fusarium solani e quatro como Fusarium complexo não ¿ solani, sendo três Fusarium napiforme e um Fusarium oxysporum, concordando com os resultados encontrados nas três metodologias aplicadas neste trabalho. A técnica de LAMP demonstrou ser mais acessível do que as técnicas de DNA microarray e PCR em tempo real por ser mais rápida, indicando ser uma metodologia promissora para ser utilizada na rotina de diagnóstico de fungos filamentosos, auxiliando em uma terapia apropriada de uma forma rápida e específica, proporcionando assim uma melhora na assistência prestada ao paciente / Abstract: This study aimed to compare the performance of the techniques of DNA microarray, loop mediated isothermal amplification (LAMP), real-time PCR and DNA sequencing for identification of species of Fusarium as agents of bloodstream infection, isolated from patients with hematologic malignancies cared for at the university hospital of State University of Campinas and the university hospital of University of Sao Paulo, in a retrospective cross study. In the study, 21 Fusarium isolates from blood were selected, being 17 samples of mycology collection of the Laboratory for Research on Fungi (LIF), Faculty of Medical Sciences, Campinas (FCM-Unicamp) and three samples of mycology collection of the Laboratory of Microbiology of FMUSP. The techniques of DNA microarray, LAMP and Real-Time PCR identified 17 of the 21 samples as Fusarium solani, and 4 isolates as Fusarium non-solani complex, showing a high performance, a 100% agreement among them and a sensitivity of 100% for the DNA microarray, LAMP and real-time PCR methods and a 100% specificity for the LAMP method. These data were validated by the DNA sequencing technique, which identified 17 isolates as Fusarium solani complex and not four as Fusarium non-solani complex, being three Fusarium napiforme and one Fusarium oxysporum, agreeing with the findings in the three methodologies applied in this work. The LAMP technique proved to be more accessible than the techniques of DNA microarray and real-time PCR to be faster, indicating a promising methodology to be used in routine diagnosis of filamentous fungi, aiding in proper therapy rapid and specific manner, thereby providing an improvement to the care of patients / Mestrado / Clinica Medica / Mestra em Clínica Médica

Various natural environments have been examined for the presence of antibiotic-resistant bacteria and/or novel resistance mechanisms, but little is known about resistance in the terrestrial deep subsurface. This study examined two deep environments that differ in their known period of isolation from surface environments and the bacteria therein. One hundred and fifty-four strains of bacteria were isolated from sediments located 170-259 m below land surface at the U.S. Department of Energy Savannah River Site (SRS) in South Carolina and Hanford Site (HS) in Washington. Analyses of 16S rRNA gene sequences showed that both sets of strains were phylogenetically diverse and could be assigned to several genera in 3-4 phyla. All of the strains were screened for resistance to 13 antibiotics by plating on selective media and 90% were resistant to at least one antibiotic. 86% of the SRS and 62% of the HS strains were resistant to more than one antibiotic. Resistance to naladixic acid, mupirocin, or ampicillin was noted most frequently. The results indicate that antibiotic resistance is common among subsurface bacteria. The somewhat higher frequencies of resistance and multiple resistance at the SRS may, in part, be due to recent surface influence, such as exposure to antibiotics used in agriculture. However, the HS strains have never been exposed to anthropogenic antibiotics but still had a reasonably high frequency of resistance. Given their long period of isolation from surface influences, it is possible that they possess some novel antibiotic resistance genes and/or resistance mechanisms. Seven of the strains from the HS that are resistant to tetracycline were examined for the presence of a novel antibiotic resistance gene. From these seven strains, a novel tetracycline resistance determinant was characterized. The predicted amino acid sequence shares only a 30% sequence similarity with TetA(Z), the most closely related previously described determinant. The new protein is a putative efflux pump with several characteristics in common with previously characterized efflux pumps including: a divergently transcribed TetR repressor, conserved GxxSDRxGRR motif, and transmembrane domains. The determinant has been assigned the name Tet 42. Functional genes from another subset of 11 HS strains that are resistant to ciprofloxacin were sequenced for resistance-conferring mutations. The most common mechanism of resistance to this antibiotic is based on mutations in the functional genes for DNA gyrase (gyrA, gyrB) and topoisomerase II (parC, parE). Sequences for the genes gyrA, gyrB, and parC in resistant strains were compared to the same sequences from ciprofloxacin-sensitive strains from the HS and Escherichia coli. The strains grouped into three genera: Arthrobacter, Sphingomonas, and Pseudomonas. All of the resistant strains possessed some mutations in their gyrase and/or topoisomerase genes that result in the substitution of amino acids not seen in the gene products of E. coli and the sensitive strains. These mutations, some of which have not been reported previously, can be considered putative resistance-conferring mutations. The resistant subsurface strains were also grown in the presence of an efflux pump inhibitor, and a majority of the cultures did not grow when the inhibitor was added. Lack of growth in the presence of the inhibitor may indicate that ciprofloxacin resistance is due entirely or in part to an efflux pump. The presence of an efflux pump might also explain why some of the strains with a higher minimum inhibitory concentration (MIC) have fewer mutations in their gyrase and/or topoisomerase genes than do strains with a lower MIC. It is possible that, along with novel mutations that may play a role in resistance, these strains also posses an uncharacterized efflux pump. A third approach used in this study to examine novel antibiotic resistance mechanisms was to look at differences in the entire proteome under normal and stressed conditions. The strain G887 is resistant to tetracycline and possesses the tetracycline resistance determinant Tet 42. Cultures of this strain were grown with tetracycline and without tetracycline. Protein extractions were performed from each culture and separated in the 1st dimension according to pI, on 4-7 Isoelectric Focusing Strips (IEF) strips and 6-11 IEF strips. After the 1st dimension separation, the proteins were separated by molecular weight on 12% acrylamide gels. The gels were stained with a fluorescent stain, imaged, and analyzed with spot analysis software. The gels run with the proteins from the tetracycline-treated culture indicated that several proteins visualized on both the 4-7 and 6-11 gels were upregulated in the presence of tetracycline. Some of these spots correspond to the molecular weight and pI for Tet A(42) or to those of several previously described general stress proteins. This work demonstrates that there is a high frequency of antibiotic resistance in the deep terrestrial subsurface and that bacteria in this environment possess uncharacterized antibiotic resistance genes and mutations that confer resistance. Given the constant emergence of antibiotic-resistant pathogenic strains in clinical settings and the problems this creates with respect to the treatment of bacterial diseases, it becomes increasingly important to characterize antibiotic resistance genes that may exist in the environment but have not yet been transferred to clinically important species. Our ability to alter existing antibiotics or develop new drugs to counter novel resistance mechanisms will be dependent on such characterizations. It might also be worthwhile to investigate subsurface bacteria for the ability to produce antibiotics themselves. There is a real potential for novel antibiotic discovery, given the length of time these bacteria have been isolated from antibiotic-producing bacteria in surface environments. / A Dissertation submitted to the Department of Biomedical Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2008. / October 3, 2008. / Antibiotic Resistance, Bacteria, Subsurface / Includes bibliographical references. / David L. Balkwill, Professor Directing Dissertation; Hank W. Bass, Outside Committee Member; Graham A. Patrick, Committee Member; Branko Stefanovic, Committee Member.

Healthcare and ancillary workers in hospital settings are at an increased risk of Tuberculosis (TB) due to the nature of their job and exposure to persons with TB. Knowledge of healthcare workers (HCWs), (physicians, residents, nurses, midlevels etc.) who provide direct care and ancillary staff (technicians, aides, administrators, etc.) who provide indirect care in medical institutions play an important role in the diagnosis, treatment, control, and prevention of TB. Research has shown a variation in knowledge based on TB prevalence, facility type, available resources, provider training and clinical experience, education level of staff, etc. The purpose of this study is to assess the knowledge of TB among HCWs and ancillary staff in an underserved medical institution who provide care to low-income populations in the United States. This is a cross sectional observational study. A validated questionnaire that assesses TB knowledge will be used. Participants from a historically black college in Tennessee will be recruited in the study. Participants will include HCWs such as attending physicians and residents from all residency programs as well as nurses, midlevels, etc. within the institution. We will also recruit ancillary staff in the same departments. The survey will be distributed between Jan. 2018-Feb. 2018, and will contain 10 questions. Information on demographics, work history (age, sex, education, job category, duration of employment, training level) and TB knowledge (general information on TB) will be captured. The survey will be distributed via email through RedCap, a secure web application for creating and managing online surveys. Emails of participants will be obtained through the institution’s employee and student directory. A minimum of 200 participants will be surveyed, to obtain a power of 80% and CI of 95%. Survey will be entered into the REDCap electronic research database and entered data from participants will be checked for completeness and accuracy. Knowledge will be assessed as: poor (75%-85% correct); and outstanding (>85% correct). We will compare differences in TB knowledge of HCWs and ancillary staff and between practicing physicians and physicians in training. Data analysis will be performed using R software. The expected results are that healthcare workers have higher knowledge level than ancillary workers and that practicing physicians have higher knowledge level than physicians in training due to years of clinical experience and education. As TB continues to be one of the leading causes of death worldwide, it is important that HCWs exhibit a good level of knowledge. The findings from this study will generate data to guide TB education efforts for providers and healthcare facility ancillary staff. Results will help to clarify misconceptions about TB transmission and enhance the quality of care for patients with TB and reduce the risk of nosocomial transmission of TB.