A presença de Candida albicans nos biofilmes microbianos aderidos na superfície interna das próteses removíveis, principalmente totais superiores, está relacionada com uma doença inflamatória no palato, conhecida como estomatite protética (EP). Assim, torna-se fundamental a realização de novos estudos sobre alternativas terapêuticas, direcionados à prótese e não somente à mucosa, que sejam simultaneamente antimicrobianas, anti-inflamatórias, não tóxicas para os tecidos bucais e que produzam menos danos à prótese que os métodos convencionais. Os fitoterápicos podem representar uma destas alternativas. Objetivos: O objetivo deste trabalho foi estudar a ação fitoterápica do Equisetum giganteum, nas concentrações de 50, 25, 16, 8 e 4 mg/mL, sobre C. albicans e descartar sua ação citotóxica sobre o palato humano bem como sobre monócitos humanos. Material e Métodos: Após coleta, obtenção e identificação de compostos por espectrometria de massas do extrato hidroalcoólico de E. giganteum, sua atividade antimicrobiana foi determinada pela concentração inibitória mínima em meio líquido, contra as cepas clínicas Candida albicans SC 5314 e Escherichia coli O:124, e a cepa padrão Staphylococcus aureus ATCC 6538. Propriedades antiaderentes do extrato, sobre biofilmes de C. albicans induzidos sobre corpos de prova de resina acrílica, foram determinadas por imunofluorescência (LIVE/DEAD) e pela análise em microscópio de varredura confocal a laser. A atividade anti-inflamatória do fitoterápico foi averiguada através da análise da produção de espécies reativas de oxigênio (ROS) por monócitos humanos estimulados por C. albicans e LPS, por meio da marcação fluorescente utilizando o reagente Cell Rox Deep Red®. Avaliação de citotoxicidade foi realizada in vitro com células epiteliais de palato humano e monócitos humanos, por meio do ensaio colorimétrico MTT. Os resultados foram expressos como média ± desvio padrão e submetidos aos testes estatísticos Teste de Kruskal-Wallis; ANOVA one-Way; ANOVA two-Way, Teste de Miller; Teste de Tukey e Dunnet; Teste de Fisher, sendo p<0,05 considerado significante. Resultados: O estudo da composição química do extrato EtOH 70% de E. giganteum evidenciou a presença de compostos fenólicos derivados dos ácidos cafeico e ferúlico, heterosídeos de flavonoides derivados de quercetina e kaempferol, além de estirilpironas. A atividade bactericida/fungicida foi comprovada em todas as concentrações testadas do extrato e contra todas as cepas avaliadas. Todas as concentrações do extrato resultaram em redução significativa dos biovolumes de células viáveis em relação a resina não tratada, o que indica interferência do fitoterápico na aderência de C. albicans à resina termopolimerizável. A atividade anti-inflamatória foi determinada pelo retorno da produção de espécies reativas de oxigênio aos níveis basais, pelos monócitos humanos ativados, quando tratados com todas as concentrações do extrato. Houve manutenção da viabilidade celular de monócitos humanos e das células epiteliais de palato humano, após contato com o fitoterápico nos períodos de 1, 12 e 24 horas. Conclusão: Estes resultados sugerem que o fitoterápico E. giganteum possui propriedades: microbicida frente a C. albicans, E. coli e S. aureus, antiaderente para C. albicans sobre a superfície da resina acrílica termopolimerizável e anti-inflamatória sobre monócitos humanos ativados por C. albicans. Além disso, o fitoterápico não comprometeu a viabilidade de monócitos humanos e de células epiteliais de palato humano. / The presence of Candida albicans in the microbial biofilms adhered to the internal surface of the removable denture, mainly the full upper ones, is related to an inflammatory palate disease known as denture stomatitis (DS). Thus, it is essential that new studies are done about therapeutic alternatives directed to the dentures, not only to the buccal mucosa, and which are, at the same time, antimicrobial, antiinflammatory, non-poisoning to the buccal tissues and that they produce less harm to the denture than the current methods. The phytotherapeutic (herbal) remedies may represent a good alternative. Objectives: The aim of this paper is to study the phytotherapeutic action of Equisetum giganteum in the concentrations of 50, 25, 16, 8 and 4 mg/mL on C.albicans and discard the cytotoxic action on the human palate, as well as on human monocytes. Material and Methods: After collecting, obtaining and identifying the compounds by means of mass spectrometry of the hydroalcoholic extract of E. giganteum, its antimicrobial activity was determined by the inhibitory minimum concentration in liquid media, against clinic strains of Candida albicans SC 5314 and Escherichia coli O:124, and standard Staphylococcus aureus ATCC 6538 strains. The antiadherent, properties of the extract on biofilms of C. albicans over acrylic resin proof specimens were determined by immunofluorescence test (LIVE/DEAD) and by the analysis in a Confocal Laser Microscope Scanning. The anti-inflammatory activity of the phytotherapeutic (herbal) remedy was assessed through the analysis of the production of reactive oxygen species (ROS) to human monocytes stimulated by C. albicans and LPS, through fluorescent lighting using the reagent Cell Rox Deep Red®. The evaluation of cytotoxicity was done in vitro with epithelial cells of human palate and human monocytes, through colorimetric MTT assay. The results were expressed in means ± standard deviation and submitted to statistics Kruskal-Wallis Test; ANOVA Two-way, Miller Test; Tukey and Dunnet Test; Fisher Test, where p<0,05 was considered significant. Results: The study of the chemical composition of the extract EtOH 70% of E. giganteum has shown a clear presence of phenolic compounds derived from caffeic and ferulic acids, flavonoid heterosides derived from quercitin and kaempferol, in addition to estirilpirones. Its bactericidal/fungicide activity was proved in all extract concentrations tested and against all evaluated strains. All extract concentrations resulted in significant reduction of bio volumes of viable cells in relation to non-treated resin, which indicates interference of the phytotherapeutic in the adherence of C. albicans to the thermopolymerizable acrylic. The antiinflammatory activity was determined by the production return of reactive oxygen specimens to basal levels, by activated human monocytes, when treated with all extract concentrations. There was cell viability of human monocytes and of human palate epithelial cells, after the contact of with the phytoterapeutic in the periods of 1, 12 and 24 hours. Conclusion: These results suggest that the phytotherapeutic E. giganteum has properties: microbicide in relation to C. albicans, E.coli and S. aureus, antiadherent to C. albicans on thermopolymerizable acrylic and antiinflammatory on human monocytes activated by C. albicans. In addition to this, the phytotherapeutic did not compromise either human monocytes viability or human palate epithelial cells.

Orientador: Ana Lucia Machado / Banca: Francisco Assis de Mollo Jr / Banca: Luiz Antonio Borelli Barros / Banca: Rogério Margonar / Banca: Raphael Freitas de Souza / Resumo:Os materiais odontológicos atuam como substrato para a adesão dos microrganismos e, consequentemente, desenvolvimento do biofilme. Tendo em vista que as características de superfície dos materiais podem interferir na adesão inicial, alterações dessas características podem prevenir ou diminuir a adesão de bactérias e fungos, evitando assim, o desenvolvimento da doença. Outro aspecto a ser considerado é que, na cavidade oral, as superfícies são recobertas pela saliva, formando um fino filme denominado película adquirida. Para simular as condições bucais, os estudos in vitro têm utilizado o condicionamento prévio em saliva humana antes da formação do biofilme. Assim, o objetivo deste estudo foi avaliar o efeito da deposição de filmes polimerizados a plasma a partir do composto organometálico hexametildisiloxano (HMDSO), nas características de superfície de materiais odontológicos (titânio, zircônia e resina acrílica), bem como na formação de biofilmes sobre esses materiais, com e sem armazenamento em saliva humana. Para isso, o HMDSO foi utilizado no processo PECVD (Plasma Enhanced Chemical Vapor Deposition) para a deposição de filmes nas superfícies dos corpos de prova, de maneira que resulte na formação de filmes com características hidrofóbicas ou hidrofílicas. Corpos de prova de cada um dos materiais foram mantidos sem deposição de filmes (grupos controles). A caracterização dos filmes obtidos foi realizada através de espectroscopia no infravermelho (FTIR), microscopia eletrônica de varredura (MEV), medida de ângulos de contato e energia de superfície, espectroscopia de fotoelétrons de raios-X (XPS) e perfilometria. Para avaliação da 13 formação de biofilmes, metade dos corpos de prova (10 × 2 mm) dos grupos experimentais e controles foram armazenados em saliva humana previamente preparada e, posteriormente, incubados com 1 × 107 ...(Resumo completo clicar acesso eletrônico abaixo) / Abstract: Dental materials act as substrates for the adhesion of microorganisms, and consequently, for biofilm development. Given that the surface characteristics of materials may interfere in the initial adhesion, changes in these characteristics may inhibit or reduce the adhesion of bacteria and fungi, thus preventing the development of diseases. Another aspect to consider is that, in the oral cavity, surfaces are covered with saliva, forming a thin film referred to as acquired salivary pellicle. In order to simulate oral conditions, in vitro studies have used preconditioning in human saliva before biofilm formation. Thus, the aim of this study was to evaluate the effect of plasma polymerized films on the surface characteristics of dental materials (acrylic resin, titanium and zirconia), as well as on the biofilm formation on these materials, with and without preconditioning in human saliva. For this purpose, the monomer hexamethyldisiloxane HMDSO was used as precursor in the PECVD (Plasma Enhanced Chemical Vapor Deposition) process. Deposition parameters were varied to produce a range of films with hydrophobic or hydrophilic characteristics. Specimens of each material without film deposition were used as controls. Characterization of the films was performed by Fourier Transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle measurements and surface free energy, X-ray photoelectron spectroscopy (XPS), and profilometry. To evaluate biofilm formation, half of the test specimens (10 × 2 mm) of the experimental and control groups were stored in previously prepared 16 human saliva and afterwards incubated with 1 × 107 cells/mL of both Candida albicans (for acrylic resin) and Porphyromonas gingivalis (for titanium and zirconia). Samples without preconditioning in saliva were also incubated in the respective microorganisms... (Complete abstract electronic access below) / Doutor

Orientador: Antonio Olavo Cardoso Jorge / Banca: Luciane Dias de Oliveira / Banca: Mariella Vieira Pereira Leão / Resumo: O objetivo foi avaliar as interações entre Candida albicans (ATCC 18804) com Streptococcus mitis (49456) e Streptococcus sanguinis (10556) in vitro e in vivo avaliando-se a possível influência destas associações, na expressão de genes, na filamentação e formação de biofilme de Candida albicans. A formação de biofilme, foi realizado mono e multiespécie em placa de 96 poços por 48 h à 37 ºC com 5% CO2. Os biofilmes foram desagregados e diluídos para semeadura em ágar e após incubação as UFC/mL foram contadas. A filamentação de C. albicans, in vitro foi realizada em placas de 24 poços e in vivo em Galleria mellonella, com análise histológica e contagem de UFC/mL. A avaliação da expressão gênica de ALS1, ALS3, BRC1, CPH1, EFG1 e HWP1, foi realizada por PCR em tempo real utilizando o gene normalizador ACT1. Os resultados da UFC/mL (p < 0.05), demonstrou que o biofilme de C. albicans monoespécie apresentou maior crescimento, quando comparado com o biofilme associado com S. mitis (p = 0,001) ou com S. sanguinis (p = 0,001). A filamentação in vitro demonstrou que a interação com S. mitis inibiu a filamentação de C. albicans (p = 0,0006), entretanto, a interação com S. sanguinis não inibiu (p = 0,1554). Os genes ALS1, ALS3 e HWP1 foram super expressos na interação com S. mitis. A interação com S. sanguinis, promoveu super expressão dos genes ALS3 e HWP1. Os genes BRC1, CPH1 e EFG1 foram super expressos na interação com S. mitis e sub expressos, na interação com S. sanguinis. Não houve... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract :The objetive was to evaluate the interactions between Candida albicans (ATCC 18804) with Streptococcus mitis (49456) and Streptococcus sanguinis (10556) in vitro and in vivo evaluating the possible influence of these associations, in the expression of genes, in the filamentation and biofilm formation of Candida albicans. Biofilm formation was performed mono- and multispecies in 96-well plate for 48 h at 37 ºC with 5% CO2. Biofilms sonicated and diluted for sowing on agar and after incubation the colonies counted to obtain the colony forming units (CFU/mL). The filamentation in vitro was performed in 24-well plate and in vivo Galleria mellonella, with histological and CFU/mL. The evaluation of gene expression ALS1, ALS3, BRC1, CPH1, EFG1 and HWP1 was performed by real-time PCR using the normalizing gene ACT1. The results of CFU/ml (p<0.05), found that C. albicans biofilm monoespécie showed increased growth, as compared to the biofilm associated with S. mitis (p = 0.001) and S. sanguinis (p = 0.001). The filamentation in vitro demonstrated that the interaction with S. mitis inhibited C. albicans filamentation (p = 0.0006), interaction with S. sanguinis could not (p = 0.1554). The ALS1, ALS3, HWP1 gene, were superexpressed in S. mitis interaction. Interaction with S. sanguinis, promoted overexpression of ALS3 and HWP1 genes. The BRC1 genes, CPH1 and EFG1 were super expressed in interaction with S. mitis and sub expressed when there was interaction with S. sanguinis. There was no statistical difference in the in vivo studies of filamentation and CFU/mL. It follows that in vitro, S. mitis and S. sanguinis were able to inhibit the formation of C. albicans biofilms. Like the interaction with S. mitis inhibited its filamentation. The interaction with S. mitis appears to increase the virulence factors of C. albicans. ALS1, ALS3, HWP1 as the ...(Resumo completo, clicar acesso eletrônico abaixo). / Mestre

A presença de Candida albicans nos biofilmes microbianos aderidos na superfície interna das próteses removíveis, principalmente totais superiores, está relacionada com uma doença inflamatória no palato, conhecida como estomatite protética (EP). Assim, torna-se fundamental a realização de novos estudos sobre alternativas terapêuticas, direcionados à prótese e não somente à mucosa, que sejam simultaneamente antimicrobianas, anti-inflamatórias, não tóxicas para os tecidos bucais e que produzam menos danos à prótese que os métodos convencionais. Os fitoterápicos podem representar uma destas alternativas. Objetivos: O objetivo deste trabalho foi estudar a ação fitoterápica do Equisetum giganteum, nas concentrações de 50, 25, 16, 8 e 4 mg/mL, sobre C. albicans e descartar sua ação citotóxica sobre o palato humano bem como sobre monócitos humanos. Material e Métodos: Após coleta, obtenção e identificação de compostos por espectrometria de massas do extrato hidroalcoólico de E. giganteum, sua atividade antimicrobiana foi determinada pela concentração inibitória mínima em meio líquido, contra as cepas clínicas Candida albicans SC 5314 e Escherichia coli O:124, e a cepa padrão Staphylococcus aureus ATCC 6538. Propriedades antiaderentes do extrato, sobre biofilmes de C. albicans induzidos sobre corpos de prova de resina acrílica, foram determinadas por imunofluorescência (LIVE/DEAD) e pela análise em microscópio de varredura confocal a laser. A atividade anti-inflamatória do fitoterápico foi averiguada através da análise da produção de espécies reativas de oxigênio (ROS) por monócitos humanos estimulados por C. albicans e LPS, por meio da marcação fluorescente utilizando o reagente Cell Rox Deep Red®. Avaliação de citotoxicidade foi realizada in vitro com células epiteliais de palato humano e monócitos humanos, por meio do ensaio colorimétrico MTT. Os resultados foram expressos como média ± desvio padrão e submetidos aos testes estatísticos Teste de Kruskal-Wallis; ANOVA one-Way; ANOVA two-Way, Teste de Miller; Teste de Tukey e Dunnet; Teste de Fisher, sendo p<0,05 considerado significante. Resultados: O estudo da composição química do extrato EtOH 70% de E. giganteum evidenciou a presença de compostos fenólicos derivados dos ácidos cafeico e ferúlico, heterosídeos de flavonoides derivados de quercetina e kaempferol, além de estirilpironas. A atividade bactericida/fungicida foi comprovada em todas as concentrações testadas do extrato e contra todas as cepas avaliadas. Todas as concentrações do extrato resultaram em redução significativa dos biovolumes de células viáveis em relação a resina não tratada, o que indica interferência do fitoterápico na aderência de C. albicans à resina termopolimerizável. A atividade anti-inflamatória foi determinada pelo retorno da produção de espécies reativas de oxigênio aos níveis basais, pelos monócitos humanos ativados, quando tratados com todas as concentrações do extrato. Houve manutenção da viabilidade celular de monócitos humanos e das células epiteliais de palato humano, após contato com o fitoterápico nos períodos de 1, 12 e 24 horas. Conclusão: Estes resultados sugerem que o fitoterápico E. giganteum possui propriedades: microbicida frente a C. albicans, E. coli e S. aureus, antiaderente para C. albicans sobre a superfície da resina acrílica termopolimerizável e anti-inflamatória sobre monócitos humanos ativados por C. albicans. Além disso, o fitoterápico não comprometeu a viabilidade de monócitos humanos e de células epiteliais de palato humano. / The presence of Candida albicans in the microbial biofilms adhered to the internal surface of the removable denture, mainly the full upper ones, is related to an inflammatory palate disease known as denture stomatitis (DS). Thus, it is essential that new studies are done about therapeutic alternatives directed to the dentures, not only to the buccal mucosa, and which are, at the same time, antimicrobial, antiinflammatory, non-poisoning to the buccal tissues and that they produce less harm to the denture than the current methods. The phytotherapeutic (herbal) remedies may represent a good alternative. Objectives: The aim of this paper is to study the phytotherapeutic action of Equisetum giganteum in the concentrations of 50, 25, 16, 8 and 4 mg/mL on C.albicans and discard the cytotoxic action on the human palate, as well as on human monocytes. Material and Methods: After collecting, obtaining and identifying the compounds by means of mass spectrometry of the hydroalcoholic extract of E. giganteum, its antimicrobial activity was determined by the inhibitory minimum concentration in liquid media, against clinic strains of Candida albicans SC 5314 and Escherichia coli O:124, and standard Staphylococcus aureus ATCC 6538 strains. The antiadherent, properties of the extract on biofilms of C. albicans over acrylic resin proof specimens were determined by immunofluorescence test (LIVE/DEAD) and by the analysis in a Confocal Laser Microscope Scanning. The anti-inflammatory activity of the phytotherapeutic (herbal) remedy was assessed through the analysis of the production of reactive oxygen species (ROS) to human monocytes stimulated by C. albicans and LPS, through fluorescent lighting using the reagent Cell Rox Deep Red®. The evaluation of cytotoxicity was done in vitro with epithelial cells of human palate and human monocytes, through colorimetric MTT assay. The results were expressed in means ± standard deviation and submitted to statistics Kruskal-Wallis Test; ANOVA Two-way, Miller Test; Tukey and Dunnet Test; Fisher Test, where p<0,05 was considered significant. Results: The study of the chemical composition of the extract EtOH 70% of E. giganteum has shown a clear presence of phenolic compounds derived from caffeic and ferulic acids, flavonoid heterosides derived from quercitin and kaempferol, in addition to estirilpirones. Its bactericidal/fungicide activity was proved in all extract concentrations tested and against all evaluated strains. All extract concentrations resulted in significant reduction of bio volumes of viable cells in relation to non-treated resin, which indicates interference of the phytotherapeutic in the adherence of C. albicans to the thermopolymerizable acrylic. The antiinflammatory activity was determined by the production return of reactive oxygen specimens to basal levels, by activated human monocytes, when treated with all extract concentrations. There was cell viability of human monocytes and of human palate epithelial cells, after the contact of with the phytoterapeutic in the periods of 1, 12 and 24 hours. Conclusion: These results suggest that the phytotherapeutic E. giganteum has properties: microbicide in relation to C. albicans, E.coli and S. aureus, antiadherent to C. albicans on thermopolymerizable acrylic and antiinflammatory on human monocytes activated by C. albicans. In addition to this, the phytotherapeutic did not compromise either human monocytes viability or human palate epithelial cells.

Existem poucos estudos a respeito da presença de constituintes fúngicos na circulação sanguínea de indivíduos com estomatite por dentadura (ED) (AHMAD et al., 2002), considerada uma forma localizada de candidose; o que poderia caracterizar o poder de invasão sistêmica do fungo nesta condição local, bem como um prévio reconhecimento desses antígenos por células presentes na circulação sanguínea do hospedeiro, o que poderia explicar aspectos específicos da resposta imune localizada e sistêmica. Assim sendo, este trabalho teve por objetivo avaliar a presença do fungo Candida albicans (C. albicans) no palato, na superfície interna das próteses totais superiores e no sangue de pacientes com ED, em dois momentos distintos. A população de estudo foi composta por indivíduos usuários de prótese total superior (PTS), com e sem estomatite por dentadura, avaliados e selecionados nas clínicas de graduação e pós-graduação da Disciplina de Prótese, do Departamento de Prótese, da Faculdade de Odontologia de Bauru da Universidade de São Paulo (FOB USP). Indivíduos não usuários de próteses removíveis constituíram o grupo controle. Assim o trabalho foi constituído por três grupos, cada um com 14 pacientes. As lesões de estomatite por dentadura foram diagnosticadas clinicamente e por meio de confirmação microbiológica em CHROMAgar Candida, a partir de material biológico coletado da mucosa palatal e da superfície interna da PTS. A PCR foi realizada quando da ocorrência do crescimento de colônias verdes para diferenciação das espécies C. albicans e C. dubliniensis. As amostras de sangue foram analisadas para a detecção de fragmentos de DNA responsáveis pela codificação da proteína da parede da hifa1(Hwp1) de C. albicans, utilizando a técnica da PCR. Os resultados demonstraram que nem os usuários de PTS, independentemente da presença de ED, nem os voluntários não usuários apresentaram a proteína Hwp1 no sangue, em nenhuma das amostras coletadas. A presença de fungos do gênero Candida foi mais frequente (p 0,005) entre os usuários de PTS com ED quando comparado com os outros indivíduos. Além disso, pudemos constatar que os pacientes com diagnóstico clínico e microbiológico de ED não apresentaram distribuição sanguínea de C. albicans. / There are few studies about the presence of yeast constituents in the bloodstream of patients with denture stomatitis (DE), a localizated kind of candidiasis; what could characterize the yeast systemic invasion power in this local condidition, and also previous acknowledgement of these antigens by cells of the entertainer bloodstream, and explain specific features of the immune located and systemic answer. So being, this work had as a goal to evaluate the presence of the yeast Candida albicans (C. albicans) at the palate, at the internal surface of the upper denture and in the blood of patients with DE, at two different moments. The population of study was composed by individuals both with and without upper denture, with and without stomatitis, assessed and selected in the clinics of graduation and postgraduation of the Discipline of Prosthesis, of the Department of Prosthesis, of the Faculdade de Odontologia de Bauru of the University of São Paulo (FOB USP). Individuals who are not users of removable dentures constituted the group control. So the work was constituted by three groups, each one with 14 patients. The injuries of stomatitis were diagnosed clinically and through microbiological confirmation in CHROMAgar Candida, from biological collected material of the palatal mucosa and of the internal surface of the upper denture. The PCR was carried out when the growth of green colonies for differentiation of the stain C. albicans and C. dubliniensis happened. The samples of blood were analyzed for the detection of fragments of DNA responsible for the codification of the hyphal wall protein (Hwp1) of C. albicans. The results demonstrated that not even the users of upper denture, independently of the presence of the DE, not even the volunteers who are not users presented the protein Hwp1 in the blood, in none of the collected samples. The yeast Candida presence was more frequent (p 0,005) in the group 1 when compared with the other groups. Morever, we can conclude that patients with clinic and microbiologic diagnostic have not presented bloodstream distribution of C. albicans.

So, Cheung Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 106-117). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.iii / 摘要 --- p.v / List of Abbreviations --- p.vii / List of Figures --- p.viii / List of Tables --- p.x / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Candida albicans and candidiasis / Chapter 1.1.1 --- Historical background --- p.1 / Chapter 1.1.2 --- C. albicans infections --- p.2 / Chapter 1.1.3 --- Current challenges in the treatment of C. albicans --- p.3 / Chapter 1.2 --- Photodynamic therapy --- p.11 / Chapter 1.2.1 --- Historical aspects and development --- p.11 / Chapter 1.2.2 --- Basic principle of photodynamic therapy --- p.13 / Chapter 1.2.3 --- Light applicator --- p.16 / Chapter 1.2.4 --- Generations of photosensitizer --- p.17 / Chapter 1.2.5 --- Characteristics of phthalocyanines --- p.20 / Chapter 1.2.6 --- Photodynamic antimicrobial chemotherapy (PACT) --- p.22 / Chapter 1.3 --- Aim of present study --- p.24 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Synthesis of BAM-SiPc --- p.27 / Chapter 2.2 --- Preparation of BAM-SiPc solution --- p.27 / Chapter 2.3 --- Yeast strains and culture conditions --- p.28 / Chapter 2.4 --- Light source --- p.29 / Chapter 2.5 --- Assays of PDT with planktonic C. albicans / Chapter 2.5.1 --- Photodynamic treatment on planktonic cells --- p.30 / Chapter 2.5.2 --- Clonogenic assay --- p.32 / Chapter 2.5.3 --- Cellular uptake of BAM-SiPc --- p.32 / Chapter 2.5.4 --- Distribution of BAM-SiPc in planktonic cells / Chapter 2.5.4.1 --- Fluorescence microscopic analyses --- p.33 / Chapter 2.5.4.2 --- Confocal laser scanning microscopic (CLSM) analyses --- p.34 / Chapter 2.5.5 --- Determination of ROS level in planktonic cells --- p.34 / Chapter 2.5.6 --- Distribution of ROS in planktonic cells --- p.35 / Chapter 2.5.7 --- Effect of ROS inhibitors --- p.35 / Chapter 2.5.8 --- Membrane integrity assay --- p.36 / Chapter 2.6 --- Assays of PDT with C. albicans biofilm / Chapter 2.6.1 --- Biofilm formation --- p.37 / Chapter 2.6.2 --- Photodynamic treatment on C. albicans biofilm --- p.38 / Chapter 2.6.3 --- Viability assays / Chapter 2.6.3.1 --- XTT reduction assay --- p.38 / Chapter 2.6.3.2 --- Molecular probes staining --- p.40 / Chapter 2.6.4 --- Determination of ROS level in biofilm --- p.41 / Chapter 2.6.5 --- Distribution of BAM-SiPc in biofilm --- p.41 / Chapter 2.6.6 --- Photodynamic treatment on C. albicans from resuspended biofilm --- p.42 / Chapter 2.7 --- Statistical analysis --- p.42 / Chapter Chapter 3 --- Results / Chapter 3.1 --- BAM-SiPc mediated PDT on planktonic C. albicans / Chapter 3.1.1 --- Antifungal effect of BAM-SiPc on C. albicans / Chapter 3.1.1.1 --- PDT activities on different strains of C. albicans --- p.43 / Chapter 3.1.1.2 --- Effect of different densities of cells --- p.47 / Chapter 3.1.1.3 --- Effect of a washing step before illumination --- p.47 / Chapter 3.1.2 --- Optimization of PDT conditions with BAM-SiPc on C. albicans / Chapter 3.1.2.1 --- Time course study --- p.50 / Chapter 3.1.2.2 --- Light dose study --- p.50 / Chapter 3.1.3 --- Uptake of BAM-SiPc --- p.53 / Chapter 3.1.4 --- Distribution of BAM-SiPc in the planktonic cells / Chapter 3.1.4.1 --- Analysis with fluorescence microscopy --- p.56 / Chapter 3.1.4.2 --- Analysis with CLSM --- p.56 / Chapter 3.1.5 --- ROS production upon PDT treatment / Chapter 3.1.5.1 --- ROS level in the planktonic cells --- p.59 / Chapter 3.1.5.2 --- Distribution of ROS production --- p.61 / Chapter 3.1.5.3 --- Effect of different ROS inhibitors on BAM-SiPc's potency --- p.64 / Chapter 3.1.6 --- Membrane integrity --- p.66 / Chapter 3.2 --- BAM-SiPc mediated PDT on C. albicans biofilm / Chapter 3.2.1 --- Establishment of the biofilm model with 192887g --- p.69 / Chapter 3.2.2 --- Photodynamic treatment on 192887g biofilm / Chapter 3.2.2.1 --- Viability assay - XTT assay --- p.72 / Chapter 3.2.2.2 --- Viability assay ´ؤ LIVE/DEAD BacLight Bacterial Viability kit --- p.72 / Chapter 3.2.3 --- ROS level in the biofilm after PDT treatment --- p.75 / Chapter 3.2.4 --- Distribution of BAM-SiPc in the biofilm --- p.75 / Chapter 3.2.5 --- Photodynamic treatment on C. albicans from resuspended biofilm --- p.79 / Chapter Chapter 4 --- Discussion --- p.81 / Chapter 4.1 --- Antifungal effect of BAM-SiPc on the planktonic C. albicans --- p.81 / Chapter 4.2 --- Effects of different conditions on the photodynamic treatment with BAM- SiPc --- p.83 / Chapter 4.3 --- Mechanistic study of the antifungal effect of BAM-SiPc --- p.86 / Chapter 4.3.1 --- Interaction between BAM-SiPc and C. albicans --- p.86 / Chapter 4.3.2 --- ROS as mediator of cell damage --- p.89 / Chapter 4.3.3 --- Analysis of membrane integrity upon photodynamic treatment --- p.91 / Chapter 4.4 --- Establishment of the biofilm model of C. albicans --- p.92 / Chapter 4.5 --- In vitro effect of BAM-SiPc mediated PDT on C. albicans biofilm --- p.95 / Chapter Chapter 5 --- Conclusion and Future Perspectives / Chapter 5.1 --- Conclusion --- p.101 / Chapter 5.2 --- Future perspectives --- p.102 / References --- p.106

We assembled the genome of the human fungal pathogen Candida albicans into eight chromosomes, and annotated each of its genes. A genome comparison with Saccharomyces cerevisiae revealed an increased number of C. albicans superoxide dismutase genes. We analyzed the expression patterns and the function of one of these genes, SOD5, whose role is to protect the pathogen against extracellularly produced, neutrophil-generated superoxide radicals. Comparative genomics also showed that although many of the C. albicans transcription factors, such as Gal4p and Gcn4p, have homologues in S. cerevisiae, the sequence similarities occur only in the DNA binding motifs of those proteins. Deletion analysis of CaGcn4 and CaGal4 proteins show that the N' and C' termini respectively are needed for their transactivation ability. These two transactivation regions show no sequence similarity to the equivalent domains in their S. cerevisiae homologues, and the two C. albicans transactivatiog domains themselves show little similarity. A comparative analysis of the transcriptional machinery between C. albicans and S. cerevisiae showed low sequence similarity of the mediator complex that bridges activation domains of transcription factors to the RNA polymerase II complex. We performed a comparison of intergenic DNA regions to identify the cis-regulatory elements from Candida and Saccharomyces species to examine the organization of the transcriptional regulatory networks between these two organisms. We observed that the C. albicans GAL genes lack Gal4p binding sites, but that such sites are found upstream of telomeric genes and genes involved in glycolysis, and we show that CaGal4p regulates the expression of those genes. We identified the regulatory DNA sequences in the promoters of GAL genes, including a GAL-specific palindrome necessary for GAL10&ogon; expression. Cph1p, the C. albicans homolog of the Ste12p transcription factor controlling pheromone-induced gene expression in yeast, acts through this GAL-specific palindrome, functioning as an activator in the presence of galactose. This shows C. albicans and S. cerevisiae can regulate the same process by different regulatory circuits.

Thesis (Ph. D.)--University of Iowa, 1998. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Iowa, 1998. / Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:28:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-28Bitstream added on 2014-06-13T20:58:44Z : No. of bitstreams: 1 carmello_jc_me_arafo.pdf: 701741 bytes, checksum: 55eb9d8f5746ef34ede24573f0c2455a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve por objetivo avaliar a efetividade da terapia fotodinâmica (PDT) mediada pelo fotossensibilizador (FS) Photodithazine® (PDZ), associado à luz do tipo LED (660nm). Para tanto, foram utilizados 55 camundongos com aproximadamente 6 semanas de vida, os quais foram submetidos a indução de candidose no dorso da língua. Inicialmente os animais foram imunossuprimidos e no dia seguinte se realizou a inoculação de C. albicans na língua dos mesmos por meio de swabs embebidos na suspensão (107 Ufc/mL). Para a realização da terapia fotodinâmica o FS foi avaliado nas concentrações de 75, 100, 125 e 150mg/L. Tais grupos experimentais foram denominados de (P+L+ 75mg/L, P+L+ 100mg/L, P+L+ 125mg/L, P+L+ 150mg/L) associados a uma dose de luz de 37,5 J/cm2. Para a verificação apenas do efeito da PDZ, a mesma foi aplicada na língua dos animais, sem iluminação (grupos denominados de P+L- 75mg/L, P+L- 100mg/L, P+L- 125mg/L, P+L- 150mg/L). O efeito da luz foi avaliado por meio da iluminação das línguas com dose de luz de 37,5J/cm2, (grupo denominado de P-L+ 37,5J/cm2). Um grupo recebeu apenas inoculação por Candida (grupo P-L-, controle positivo), outro grupo não recebeu nenhum tratamento e nem inoculação fúngica (grupo CN – controle negativo). Após os experimentos realizou-se a recuperação de C. albicans das línguas dos animais por meio de swabs que foram esfregados sobre as mesmas durante 1 minuto. Esses swabs foram embebidos em tubos de ensaio com 1mL de solução salina, e diluições seriadas foram realizadas e colocadas em placas de petri com SDA. Após 48 horas de incubação a 37º C as células fúngicas foram quantificadas e o número de Ufc/mL foi determinado e analisado pelo teste ANOVA (P<.05). Os camundongos foram sacrificados e tiveram as línguas removidas cirurgicamente para realização da análise histológica. Os resultados demonstraram... / The aim of this investigation was to evaluate the effectiveness of photodynamic therapy (PDT) mediated by photossensitizer Photodithazine® (PDZ) associated with LED light (660nm) for the photoinactivation of C. albicans in a murine model of oral candidosis. Fifty-five 6-week-old female Swiss mice were immunossuppressed and in the next day small cotton pads were soaked in a C. albicans cell suspension (107CFU/mL) and swabbed in the oral cavity of mice. PDT was performed and the PS was applicated topically on the dorsum of the tongue of mice at concentrations 75, 100, 125 and 150mg/L (P+L+75, P+L+100, P+L+125 and P+L+150mg/L) associated with LED at a fluence of 37,5J/cm2. The effect of PS only was tested by application of PDZ for the same period of pre-irradiation time and irradiation at the same concentration as that for the P+L+ group, without the LED illumination (P+L-75, P+L-100, P+L-125 and P+L-150mg/L). To verify the effect of the light only, the group was exposed to the same LED dose mentioned previously (P-L+ 37,5J/cm2), 1 group). The positive control did not receive any PS or light (P-L-). The negative control group (CN) of animals was evaluated and mice did not receive any treatment. After treatment the dorsum of the tongue was swabbed for 1 minute with a cotton pad to recover C. albicans cells and the microbiological evaluation was performed. The yeast colony counts were quantified and the number of CFU/mL was determined and analyzed by ANOVA test (P<.05). Animals were killed 24 hours after treatment and the tongue of all mice were surgically removed for histological analysis. The results of this investigation demonstrated that PDT was effective in reducing C. albicans recovered from the tongue of mice at concentrations 100, 125 and 150mg/L of PS when compared with the animals from the positive control group (P-L-) (P<0.05). There was no difference between these concentrations... (Complete abstract click electronic access below)