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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Photodynamic inactivation of Candida albicans by BAM-SiPc.

January 2008 (has links)
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
172

Genotyping Candida species and molecular analysis of C. albicans gene encoding mevalonate pyrophosphate decarboxylase /

Dassanayake, Ranil Samantha. January 2000 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 203-238).
173

Postgenomic studies of Candida albicans

Martchenko, Mikhail. January 2007 (has links)
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˛ 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.
174

Characterisation of Candida species : a case study in three teaching hospitals in Ghana. / Candida albicans populations in Ghana

Adjapong, Gloria Nana Yaa January 2014 (has links)
Candida species are ubiquitous, ranging from pure saprobes through endo-symbionts of animals, to pathogens in many animals including humans. Some of the pathogenic species are of medical importance, especially Candida albicans. However, the prevalence of other non-albicans Candida species as human pathogens has been increasing worldwide. The aim of this study was to use conventional phenotypic tests and molecular methods to isolate, identify and characterise 600 Candida isolates from three teaching hospitals in Ghana, namely Korle Bu, Komfo Anokye and Tamale from mid-January to April, 2012. The prevalence of these species in cases of genitourinary candidiasis and pelvic inflammatory disease was investigated. Preliminary identification and characterisation of Candida isolates using four conventional phenotypic tests showed that C. albicans was the most common species, which constituted 41% of the isolates whereas non-albicans Candida species constituted 59% of the total number of Candida isolates. In patients presenting with vulvovaginal candidiasis (VVC) for at least two or more times, chi-square analysis indicates that the frequency of Candida species isolated were not statistically different from patients presenting for the first time with VVC. Candida albicans was the most common species in vaginal swabs from patients presenting with vulvovaginal candidiasis (VVC) for the first time in each of the three locations, present in 53.4% of the total swabs. The other species that were present were C. glabrata (21.6%), C. parapsilosis (15.5%), C. tropicalis (4.7%) and C. krusei (4.7%). Similar Candida species distributions were found in swabs taken from patients presenting with suspected pelvic inflammatory disease (PID). Across the three locations, however, there was a significant difference in the frequency of C. albicans, which was present in 68 and 69.6% of patients from Komfo Anokye and Tamale, but only 26.7% of patients from Korle Bu. Urine samples were taken in two of the locations, Korle Bu and Tamale, from female patients presenting with candiduria. Statistical analysis indicated a significant difference in the frequency of Candida isolates in cases of candiduria between the two locations. In Korle Bu, C. glabrata was the most prominent species (37.8%) followed by C. albicans (22.4%), C. parapsilosis (21.7%), C. tropicalis (10.5%), C. krusei (7%) and C. lusitaniae (0.7%). In Tamale, the species distribution was C. albicans (60.9%), C. glabrata (21.7%), C. parapsilosis (13%) and C. krusei (4.3%). The data highlight the prevalence of species other than C. albicans in case of candidiasis in Ghana. Delineation of C. albicans strains using the 25S rDNA to investigate the genotypic variation among C. albicans isolates showed that genotype A constituted about 95% of the Ghanaian C. albicans isolates, genotypes B and C constituted 2.5% each respectively. The general-purpose genotype (GPG) which corresponds to clade 1 among C. albicans was also investigated to know the prevalence of clade 1 among the C. albicans isolates investigated. The presence or absence of general-purpose genotype (GPG) gene was used to categorise the 240 C. albicans to clade 1 or other clade. The test revealed that 64.2% had the GPG genotype which corresponds to clade 1 and the remaining 35.8% were of non-GPG genotype; thus belongs to other clades. The population structure of C. albicans from the three teaching hospitals indicates a mainly clonal and homogeneous population across the three sampling locations from Ghana. Molecular analyses of the transposable group 1 intron in the ITS1-5.8S-ITS2 region using universal primer pair ITS1 and ITS4 revealed the presence of two rare Candida species; Candida rugosa and Candida mesorugosa. To the best of my knowledge this is the first report of either of these in Africa. Antifungal susceptibility tests among Candida isolates recovered from patients presenting with clinically suspected or symptomatic candidal vaginitis for the first time and patients presenting with candidal vaginitis on two or more occasions revealed a high percentage of Fluconazole-resistant C. albicans. This study highlights the prevalence of species other than C. albicans in cases of candidiasis in Ghana. Furthermore, this study has also demonstrated that no single conventional phenotypic test has been highly efficient to delineate Candida species into their respective species type. Thus, development of an identification scheme, which can discriminate between Candida isolates both at species and strain levels, will have prognostic and therapeutic significance for effective patient management.
175

Molecular epidemiology of Candida albicans in patients with AIDS

Vargas, Kaaren Giselle. January 1998 (has links)
Thesis (Ph. D.)--University of Iowa, 1998. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
176

Molecular epidemiology of Candida albicans in patients with AIDS

Vargas, Kaaren Giselle. January 1998 (has links)
Thesis (Ph. D.)--University of Iowa, 1998. / Includes bibliographical references.
177

Efetividade da Terapia fotodinâmica mediada pelo fotossensibilizador photodithazine® na inativação de candida albicans in vivo

Carmello, Juliana Cabrini [UNESP] 28 March 2011 (has links) (PDF)
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)
178

Efeitos de diferentes tratamentos a plasma e de variações na coleta, preparo e pré-condicionamento com saliva na adesão de Candida a uma resina para a base de prótese /

Zamperini, Camila Andrade. January 2011 (has links)
Orientador: Ana Lucia Machado / Banca: Wander José da Silva / Banca: Helena de Freitas Oliveira Paranhos / Banca: Francisco de Assis Mollo Junior / Banca: Gelson Luis Adabo / Resumo: A adesão de Candida às superfícies protéticas é o passo inicial para ocorrência da estomatite protética. Entre os diversos fatores envolvidos na adesão de Candida spp. às superfícies poliméricas estão as interações hidrofóbicas e eletrostáticas, a rugosidade superficial e a película salivar. Assim, os objetivos deste estudo foram: investigar o potencial de diferentes tratamentos a plasma (Ar/50W; ArO2/70W; AAt/130W; ArSF6/70W) de modificar uma resina acrílica para base de prótese (VIPIWAVE) para reduzir a aderência de Candida albicans (ATCC 90028), avaliada pelo ensaio de XTT e cristal violeta. O efeito da rugosidade de superfície e do pré-condicionamento com saliva também foram avaliados; investigar se modificações de superfícies por meio de dois tratamentos a plasma (Ar/50W; AAt/130W) reduziriam a aderência de Candida glabrata (ATCC 2001), avaliada pela coloração cristal violeta, sobre superfícies lisas de resina acrílica. Além disso, o efeito do pré-condicionamento com saliva também foi avaliado; e ainda, avaliar se variações nos períodos de pré-condicionamento com saliva (0 min; 30 min; 60 min; 180 min; 720 min), nos parâmetros de centrifugação (velocidade e tempo) e número de doadores de saliva influenciariam os resultados de adesão de Candida albicans a uma resina acrílica para base de prótese, avaliada por meio do ensaio de XTT e coloração cristal violeta. Além disso, a correlação entre os dois métodos utilizados para avaliação da adesão de Candida albicans também foi avaliada. Os resultados obtidos demonstraram que os tratamentos a plasma são efetivos para modificação da hidrofobicidade de superfície ou incorporação de átomos de flúor na superfície da resina acrílica. Entretanto, após os tratamentos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The adhesion of Candida to denture surfaces is the initial step for occurrence of denture stomatitis. Among the various factors involved on Candida adhesion to polymeric surfaces are the hydrophobic and eletrostatic interactions, surface roughness and pellicle salivary. Hence, the aims of this study were: to investigate the potential of different plasma treatments (Ar/50W; ArO2/70W; AAt/130W; ArSF6/70W) to modify a denture base acrylic resin (VIPIWAVE) to reduce the Candida albicans adhesion (ATCC 90028), evaluated by XTT reduction assay and crystal violet staining. The effect of surface roughness and saliva coating was also evaluated; to investigate the potential of two plasma treatments (Ar/50W; AAt/130W) to modify a denture base acrylic resin to reduce the Candida glabrata adhesion (ATCC 2001), evaluated by crystal violet staining. Moreover, the effect of saliva coating was also evaluated; and to assess the effect of different periods of preconditioning with saliva (0 min; 30 min; 60 min; 180 min; 720 min), variations in the centrifugation parameters (speed and time) and number of donors of saliva on Candida albicans adhesion to a denture base resin using crystal violet staining and XTT reduction assay. Additionally, the correlation between the two methods used for assessing Candida albicans adhesion was also evaluated. The results obtained demonstrated that the plasma treatments were effective in modifying hydrophobicity or incorporation of fluorine into acrylic resin. However, there were significant alterations in the contact angle measured after immersion in water. Groups ArO2/70W and ArSF6/70W showed significantly lower absorbance readings to Candida albicans adhesion than the other groups. No statistically significant difference in the adherence of Candida albicans, evaluated by... (Complete abstract click electronic access below) / Doutor
179

Fitossíntese de nanopartículas de prata : uma revisão e um estudo do potencial redutor do extrato da casca de romã e da atividade antifúngica dessas nanopartículas /

Sauvesuk, Luana. January 2017 (has links)
Orientador: Debora de Barros Barbosa / Banca: Luiz Fernando Gorup / Banca: Aimée Maria Guiotti / Resumo: O presente estudo revisou na literatura trabalhos entre 2006 e 2017 relacionados à fitossíntese de nanopartículas de prata (AgNP) e destacar a variedade de plantas passíveis de serem utilizadas e o quanto estas influenciam as características e propriedades dessas nanopartículas. Avaliou-se também como a temperatura (25, 50, 70 e 95°C) e a concentração de extrato da casca de romã (Punica granatum) (7, 14 e 28 mg mL-1) interferem na efetividade da reação fitoquímica por meio da quantificação dos íons Ag+ livres na solução de AgNP. A atividade antifúngica das AgNP produzidas foi avaliada por meio do método da microdiluição (CLSI M27-A2) contra cepas padrão (ATCC) de Candida albicans e Candida glabrata. As AgNP foram caracterizadas por microscopia eletrônica de varredura (MEV), difração de raios-X e espectroscopia UV/visível. O extrato da casca desidratada da romã foi obtido por maceração seguido de percolação em etanol (70%) e desidratado em rota-evaporador. Quantificou-se os fenóis totais expressos em ácido gálico por método colorimétrico e o ácido elágico por HPLC, sendo respectivamente 158,61 e 4,21 mg mL-1. Foram revisados mais de duzentos artigos relacionados à fitossintese de AgNP, onde cerca de cento e setenta plantas foram utilizadas para esta síntese e sendo a maioria delas geograficamente concentradas nos continentes asiático e europeu. As AgNP fitossintezadas no presente estudo apresentaram concentração de íons livres de Ag+ proporcional à quantidade de extrato utiliz... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present work reviewed in the literature studies of phythosynthesis of silver nanoparticles (AgNP) between 2006 and 2017, highlighting the variety of plants used to and how they can influence the characacteristics and properties of AgNP. This work also evaluated the influence of temperature (25, 50, 70 and 95°C) and concentration of peel extract of pomegranate (Punica granatum) (7, 14 and 28 mg mL-1) on the effectiveness of phytosynthesis reaction by quantifying the free Ag+ ions in the AgNP soluction. The antifungal activity of AgNP against reference strains (ATCC) of Candida albicans and Candida glabrata were evaluated by the microdilution method (CLSI M27-A2). AgNP were characterized through scanning electron microscopy (SEM), X-Ray diffraction and UV-Vis spectroscopy. The pomegranate peel was dehydrated and the hydroalcoholic extract was obtained by maceration followed by percolation, and then obtained the crude extract using a rotary evaporator. Total phenols expressed in galic acid and elagic acid were quantified in the extract using a colorimetric method and by HPLC, and the values found were 158.61 and 4.21 mg mL-1, respectively. It was found more than two hundred studies using about an hundred seventy plants to synthesize AgNP, being the majority of those plants from the Asiatic and European Continents. The AgNp phytosynthesized in the present study presented the concentration of free Ag+ ions proportional with the quantity of pomegranate peel extract and it was high when the temepratures used in the reaction were above 50ºC. Also, AgNP were effective against both Candida reference strains evaluated / Mestre
180

Epidemiologia das infecções por Candida spp. na corrente sanguínea : coorte retrospectiva em hospital terciário brasileiro / Epidemiology of bloodstream Candida spp. Infections : retrospective cohort in a Brazilian tertiary care hospital

Pasqualotto, Alessandro Comaru January 2004 (has links)
Objetivos: definir os dados demográficos, as doenças de base e os fatores de risco associados aos episódios de candidemia ocorridos na Santa Casa Complexo Hospitalar entre 17/02/1995 e 31/12/2003; identificar as espécies envolvidas nestes episódios de candidemia e determinar a mortalidade global entre estes pacientes. Métodos: estudo de coorte retrospectivo não-controlado com inclusão de todos os casos consecutivos de candidemia diagnosticados na instituição entre 17/02/1995 e 31/12/2003. Como critério de inclusão no estudo, foi exigida a presença de sinais ou sintomas temporalmente relacionados ao isolamento de Candida em hemocultivo coletado de veia periférica. Resultados: 210 pacientes com candidemia foram incluídos (infecção nosocomial em 91,0%). O sexo feminino foi mais prevalente (51,4%) e a idade mediana foi de 41,0 anos. A doença de base mais prevalente foi câncer (neoplasias sólidas 30,5% e hematológicas 9,0%). Candida albicans foi a espécie mais freqüente (38,1%), seguida de Candida parapsilosis (27,6%) e Candida tropicalis (15,7%); candidemia por Candida glabrata ocorreu em 3,8%, e por Candida krusei, em 2,4%. Procedimentos cirúrgicos foram realizados em 43,8%, cateter venoso central estava presente em 74,8%, cateter urinário em 57,1%, ventilação mecânica em 48,6% e nutrição parenteral em 33,8%; o número mediano de antimicrobianos foi 4,0 por paciente (glicopeptídeos 54,3%, carbapenêmicos 25,7%). A maioria dos pacientes com candidemia comunitária (52,6%) havia sido hospitalizada nos 60 dias anteriores à candidemia; em 21,1%, Candida foi isolada de cateter; insuficiência renal crônica (p<0,001) e hemodiálise (p=0,027) foram mais freqüentes no grupo de candidemia comunitária do que no nosocomial; a distribuição das espécies de Candida foi semelhante entre os grupos. Comparadas aos adultos, as crianças com candidemia nosocomial foram mais expostas a antimicrobianos de amplo espectro (p<0,001), ventilação mecânica invasiva (p=0,002) e nutrição parenteral (p<0,001). Candidemia nosocomial por Candida parapsilosis foi mais freqüente em crianças (p=0,002), bem como o isolamento de Candida de cateteres (p=0,019); crianças foram mais freqüentemente tratadas com anfotericina B do que adultos (p<0,001), os quais receberam mais fluconazol (p=0,013). Entre os pacientes com câncer e candidemia nosocomial, tratamento prévio com corticosteróides (p=0,004), quimioterapia (p<0,001) e cefepima (p=0,004) foram mais comuns naqueles com malignidades hematológicas; cirurgias foram mais comuns em pacientes com tumores sólidos (p<0,001), principalmente do trato gastrointestinal (p=0,016); a distribuição das espécies de Candida foi semelhante entre os grupos. Candidemia breakthrough (“de escape”) ocorreu em 10,5% dos pacientes com candidemia nosocomial; a maioria destes vinha em uso de anfotericina B em doses terapêuticas, por período mediano de 6,5 dias; o isolamento de Candida de sítios outros que o sangue foi mais freqüente nestes pacientes (p=0,028). A mortalidade dos pacientes com candidemia foi 50,5%, sem diferenças estatisticamente significativas entre pacientes com candidemia comunitária ou nosocomial, com câncer ou outros diagnósticos e com infecção breakthrough ou não-breakthrough; a mortalidade foi maior em adultos do que em crianças (p=0,005). Conclusões: espécies não-Candida albicans foram os principais agentes de candidemia; assim como em outros estudos brasileiros, a prevalência de espécies como Candida glabrata e Candida krusei foi baixa. Fatores de risco já descritos na literatura foram freqüentemente encontrados, e a distribuição dos mesmos variou de acordo com as diferentes características dos pacientes estudados. A mortalidade em pacientes com candidemia foi semelhante \à descrita na literatura.

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