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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.
61

Desenvolvimento de derivados nitrofuranos antifúngicos para o controle de infecções por Candida spp /

Marcelino, Monica Yonashiro. January 2018 (has links)
Orientador: Ana Marisa Fusco-Almeida / Coorientador: Rondinelli Donizetti Herculano / Banca: Sergio Luiz de Souza Salvador / Banca: Juliana Campos Junqueira / Banca: Jean Leandro dos Santos / Banca: Janaina Habib Jorge / Resumo: O aumento na incidência de infecções fungicas tem progredido significativamente e dados epidemiológicos mostram que as leveduras do gênero Candida são as principais responsáveis pelas micoses em humanos. A terapêutica para o tratamento dos processos infecciosos causados por fungos tem encontrado uma série de problemas, como a crescente evolução da resistência aos antimicrobianos, o número restrito de fármacos disponíveis e os efeitos colaterais. Neste contexto, faz-se necessário o desenvolvimento de antifúngicos mais eficazes e menos tóxicos. Sendo assim, o objetivo do presente estudo foi o de realizar a síntese e verificar a atividade antifúngica de derivados nitrofuranos contra células planctônicas e biofilmes de cepas padrão de Candida spp., bem como analisar os efeitos tóxicos destes compostos em modelos alternativos ao uso de mamíferos. Realizou-se a síntese e caracterização físico-química de derivados nitrofuranos. Estes tiveram sua sensibilidade testada contra células planctônicas e biofilmes de Candida spp. nos tempos de 6, 24 e 48 horas. Além disso, foram realizados ensaios de citotoxicidade dos derivados nitrofuranos, bem como ensaios de toxicidade em Galleria mellonella, Danio rerio (zebrafish) e Caenorhabditis elegans. Os resultados obtidos mostraram que os compostos L7CF 113 e L7CF165 foram os que apresentaram melhor atividade antifúngica. Os biofilmes de C. albicans, C. krusei e C. glabrata formados em 6 horas apresentaram atividade metabólica reduzida quando em... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The increase in the incidence of fungal infections has progressed significantly and epidemiological data show that yeasts of the genus Candida are the main responsible for the mycoses in humans. Therapy for the treatment of infectious processes caused by fungi has encountered a number of problems, such as the increasing evolution of antimicrobial resistance, the limited number of drugs available and the side effects. In this context, the development of more effective and less toxic antifungal agents is necessary. The objective of the present study was to perform the synthesis and to verify the antifungal activity of nitrofuran derivatives against planktonic cells and biofilms of references strains of Candida spp., as well as to analyze the toxic effects of these compounds in alternative models to the use of mammals. The physicochemical synthesis and characterization of nitrofuran derivatives was carried out. These had their sensitivity tested against planktonic cells and biofilms of Candida spp. at times of 6, 24 and 48 hours. In addition, cytotoxicity assays of nitrofuran derivatives as well as toxicity assays were performed in Galleria mellonella, Danio rerio (zebrafish) and Caenorhabditis elegans. The results obtained showed that the compounds L7CF 113 and L7CF 165 showed the best antifungal activity. The biofilms of C. albicans, C. krusei and C. glabrata formed in 6 hours showed reduced metabolic activity when in contact with the compounds L7CF 113 and L7CF 165 in concentrations equal to or greater than 62.50 μg / mL. The biofilms of C. albicans, C. glabrata, C. krusei, C. parapasilosis and C.tropicalis, formed at 24 and 48 hours, presented reduced metabolic activity for compound L7CF 113 and L7CF 165 in concentrations equal to or greater than 125 μg / mL. The cytotoxicity assays... (Complete abstract click electronic access below) / Doutor
62

Investigations of the assessment of bioequivalence of topical clotrimazole products using a dermatopharmacokinetic approach

Parfitt, Natalie Rae 05 July 2010 (has links)
The specialised nature of the stratum corneum makes it an efficient barrier to foreign substances, including drug molecules. Therefore, cutaneous drug absorption is a slow and complex process of which stratum corneum penetration is the rate limiting step. The rate and extent of stratum corneum penetration by a drug compound depends greatly on the presence of penetration enhancing/retarding excipients and therefore the clinical outcomes of a product rely greatly on the components and quality of the formulation. Hence, establishing bioequivalence between topical products is crucial to ensure that patients receiving multisource drug products are assured of the same efficacy and safety as the brand product. Since locally acting topical formulations do not target the systemic circulation, conventional methods of assessing bioequivalence using plasma levels are not appropriate. Consequently, the current regulatory guidelines require comparative clinical trials to be carried out to show bioequivalence between topical products. As these studies are very expensive and time consuming, the development of a more direct and relatively rapid and inexpensive method for determining bioequivalence between topical products is required. Clotrimazole is an anti-fungal agent where the target site of action is in the stratum corneum. In this work, tape stripping, which involves the sampling of stratum corneum, was investigated as a tool for the determination of bioequivalence between topical clotrimazole products. The tape stripping method involved the analysis of each tape strip individually and standardization of stratum corneum thickness between subjects was carried out using TEWL measurements. This approach provided detailed information regarding the amount of clotrimazole present in the stratum corneum as well as the extent of drug penetration. Prior to the tape stripping studies an HPLC method was developed for the quantitative analysis of clotrimazole from the tape strip samples. This method was shown to be accurate and reproducible across the required range. It was also shown to be selective for clotrimazole in the presence of possible interfering substances such as those present in the tape adhesive and also skin components. The bioequivalence studies were conducted using a single “uptake” time point. In order to determine an appropriate dose duration for these studies a novel approach was employed, involving a preliminary dose duration study. For the bioequivalence investigations, Canesten® Topical cream was used as both test and reference products to determine if the method was capable of showing bioequivalence. Subsequently, Canesten® Topical cream was also compared to a 1% gel formulation to determine if the method could detect formulation differences. The conventional BE limits of 0.8 – 1.25 were used for the assessment of BE, however, the clinical relevance of using these limits for dermal studies is debatable since they are derived from oral pharmacokinetic studies. Therefore, the data from the tape stripping investigations were also assessed using more realistic limits of 0.75 – 1.33 and even 0.7 – 1.44. In addition to the tape stripping studies a novel method of determining the amount of drug present in the stratum corneum, the “Residual Method”, was investigated. This method involved assaying the amount of clotrimazole found in the residual formulation after a specified dose duration had elapsed and subtracting that amount from the amount of clotrimazole initially applied. The results of tape stripping investigations showed that, if the study is sufficiently powered, tape stripping may be used to determine bioequivalence according to the conventional limits, as well as possibly detect formulation differences between different clotrimazole products. Bioequivalence assessment using the widened intervals showed that fewer subjects were required to achieve a sufficient statistical power. The variability associated with this method was acceptable and tape stripping may therefore have the potential to be used as a BE tool in a regulatory setting for clotrimazole or other antifungal topical formulations. The “Residual Method” also showed promising results as a bioequivalence tool, but further investigation and extensive validation of this method is required before it can be suggested as a regulatory method. The results of these studies have clearly indicated that tape stripping has the potential to be used as an alternative to comparative clinical trails for the assessment of bioequivalence between clotrimazole formulations and also to assess bioequivalence between other antifungal products.
63

Estudo da interação da natamicina com membranas fosfolipídicas incorporadas de esteróis /

Arima, Anderson Akira. January 2014 (has links)
Orientador: Eduardo René Pérez Gonzáles / Banca: Paulo Noronha Lisboa Filho / Banca: Agnieszka Joanna Pawlicka Maule / Banca: Leila Aparecida Chiavacci / Banca: Luiz Carlos da Silva Filho / Resumo: A natamicina (pimaricina) é um antifúngico de amplo espectro de ação, o qual já vem sendo empregado tanto como conservante alimentar, como no tratamento de infecções fúngicas superficiais. Embora esse antibiótico natural venha sendo isolado a partir de bactérias do solo (streptomyces sp.) desde 1950, o seu mecanismo de ação ainda continua desconhecido. Por essa razão, neste estudo nós investigamos o efeito desse antibióticoem dois tipos de membranas modelo: filmes de Langmuir (monocamadas) e vesículas multilamelares (lipossomos). Os resultados obtidos foram correlacionados com o mecanismo de ação da natamicina em membranas biológicas. Nos estudos envolvendo monocamadas, os efeitos da natamicina sobre as propriedades mecânicas, a morfologia e a organização molecular desses sistemas foram analisados, respectivamente, através das isotermas de compreensão, microscopia de ângulo de Brewsler (BAM) e Espectroscopia de Absorção-Reflexão Infravermelha com Polarização Modulada (PM-IRRAS); ao passo que a influência da natamicina sobre a organização e as transições de fase dos lipossomos foram monitoradas através da Ressonância Paramagnética Eletrônicae da Colorimetria Diferencial de Varredura (DSC), respectivamente / Abstract: Natamycin is a broad spectrum antifungal, that due to its low oral and topical absorption, it already has been used both for food preservative and in the treatment of superficial mycoses. Althrough this natural antibiotic has been from soil bacteria of genus Stremptomyces since 1950, its mechanism of action on lipid environment of biomembranes has not been investigated enough. For this reason, in this study we investigated the effects of this antibiotic on two types of lipid model membranes - Langmuir films (monolayers) and multilamelar vesicles (liposomes) - and the obtained results were correlated with its mode of action on biomembranes. For monolayer models, the effect of natamycin on their mechanical properties, morphology and molecular organization were analyzed by, respectively, surface pressure isotherms, Brewsler angle Microscopy (BAM) and Polarization-Modulation Infrared Reflection-Absorption Spectroscopy (PM-IRRAS); while the influence of natamycin on the lipid organization and the thermal properties for liposomes were characterized by, respectively, Electron Paramagnetic Resonance (EPR) and Differential Scanning Calorimetry (DSC) / Doutor
64

Produção de membranas antimicrobianas de fibras nanométricas contendo cinamaldeído a partir da técnica de solution blow spinning /

Lima, Aline Lins de. January 2018 (has links)
Orientador: Alexandre Luiz souto Borges / Coorientador: Eliton Souto de Medeiros / Banca: Laís Regiane da Silva Concilio / Banca: Eliandra de Sousa Trichês / Banca: Estevão Tomomitsu Kimpara / Banca: Eduardo Bresciani / Resumo: A estomatite protética é uma das afecções mais comuns e recorrentes em pacientes portadores de próteses totais. O fungo do gênero Candida, promotor dessa patologia, além de resistente se torna ainda mais complexo de ser combatido devido à dificuldade da ação de fármacos tópicos que só conseguem permanecer por um curto período no local da infecção, em virtude da dinâmica da cavidade bucal. O processo de Solution Blow Spinning permite a obtenção de fibras ultrafinas que podem ser aplicadas em vastas áreas, inclusive na bioengenharia. Uma das aplicabilidades das fibras ultrafinas é sua utilização para liberação controlada de fármacos de forma eficiente e duradoura. Dessa forma, o intuito do presente trabalho foi incorporar Cinamaldeído (CA), composto que possui propriedades antimicrobianas, a mantas de Poli(ácido lático) e Poli(etileno glicol) (PLA/PEG) e avaliá-las quanto à produção e caracterização por, Microscopia eletrônica de varredura (MEV), Termogravimetria (TGA), Calorimetria Exploratória Diferencial (DSC), Espectroscopia de infravermelho por transformada de Fourier (FTIR), Espectroscopia no ultravioleta visível (UV/vis), ensaios mecânicos e ação antifúngica. Para realização dos experimentos, foram fiadas as seguintes mantas: PLA, PLA/PEG e PLA/PEG 23,8% CA. As micrografias obtidas por MEV mostraram, que os diâmetros das fibras que não continham CA, apresentaram diâmetros semelhantes entre si, PLA (354±160 nm)a e PLA/PEG (428±250nm)a, sendo esses diâmetro menores dos que... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Denture stomatitis is one of the most common and recurrent conditions in patients with total dentures. The fungal of the genus Candida, the causer of this pathology, besides being resistant, becomes even more complex to be combated due to the difficulty of the action of topical drugs that can only remain for a short time at the site of infection due to the dynamic of the oral cavity. The Solution Blow Spinning process allows the production of ultrafine fibers that can be applied in large areas, including bioengineering. One of the applications of ultrafine fibers is their use for controlled release of drugs in an efficient and long-lasting manner. Thus, the aim of the present work was to incorporate Cinnamaldehyde (CA), a compound that has antimicrobial properties, to Poly (lactic acid) and Poly (ethylene glycol) blankets (PLA / PEG) and to evaluate them for the production and characterization by Scanning Electron Microscopy (SEM), Thermogravimetric (TGA), Differential Scanning Calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), Ultraviolet-visible (UV/vis) spectroscopy, mechanical properties and antifungal action. Antifungal activity was verified against C. albicans, C. krusey and C. glabrata by broth microdilution test, disk diffusion and anti-biofilm activity, in both multi-species and mono-species biofilms. For the experiment, three types of meshes were spun: pure PLA, PLA/PEG and PLA / PEG 23.8% CA. The micrographs obtained by SEM showed that the fibers th... (Complete abstract click electronic access below) / Doutor
65

Utilização de microrganismos e nanofibras funcionalizadas como agentes de controle de fungos toxigênicos

Veras, Flávio Fonseca January 2016 (has links)
Fungos filamentosos com capacidade de produzir micotoxinas podem estar presentes em alimentos, desde o cultivo até o produto após industrialização. Devido a isso, estratégias para controlar o crescimento fúngico devem ser investigadas, a fim de evitar o desenvolvimento desses microrganismos, bem como a produção de suas toxinas nos alimentos. Neste trabalho, duas abordagens para o controle de fungos toxigênicos foram avaliadas. A primeira estratégia foi a utilização de bactérias provenientes de diferentes ambientes aquáticos, sendo que 10 linhagens de Bacillus spp. e a linhagem Pseudomonas sp. 4B foram testadas quanto à influência sobre os parâmetros de crescimento (taxas de crescimento micelial, esporulação e germinação de esporos) de fungos toxigênicos (Aspergillus e Penicillium) e formação de micotoxinas. Todas as bactérias foram capazes de inibir o crescimento dos fungos em meio de cultura, apresentando halos de inibição variando de 1,0 até 15,7 mm. Bacillus sp. P11 apresentou resultados mais expressivos em relação às demais linhagens do gênero Bacillus com maiores valores de redução na maioria dos parâmetros de crescimento. Além disso, Bacillus sp. P11 e Pseudomonas sp. 4B apresentaram efeito sobre as taxas de crescimento micelial, esporulação e germinação de esporos, com níveis de redução acima de 43,3, 32,1 e 84,1% respectivamente. Mesmo assim, as demais linhagens também apresentaram resultados satisfatórios sobre esses parâmetros. Estas bactérias também reduziram a síntese de aflatoxina B1 e ocratoxina A em mais de 94 e 63%, respectivamente, quando cultivadas simultaneamente com os fungos produtores de cada micotoxina. Adicionalmente, a capacidade de Bacillus sp. P11 em produzir os lipopeptídeos iturina A (167,9 mg/mL de extrato butanólico) e surfactina (361,9 mg/mL de extrato butanólico) foi confirmada. Estes compostos podem ter contribuído para a atividade antifúngica desta bactéria. A segunda estratégia investigada neste estudo para controlar o desenvolvimento de fungos toxigênicos foi o emprego de nanofibras de poli-ɛ-caprolactona (PCL) incorporadas com cetoconazol e natamicina como material antimicrobiano. Nesta abordagem, as nanofibras foram produzidas pela técnica de eletrofiação e posteriormente caracterizadas e avaliadas quanto ao seu potencial antifúngico. Nanofibras funcionalizadas com cetoconazol ou natamicina apresentaram atividade antifúngica contra os isolados toxigênicos uma vez que zonas de inibição variando de 6 a 44 mm foram observadas. Além disso, as análises de microscopia eletrônica e espectroscopia demonstraram que a incorporação dos antifúngicos não altera de forma expressiva as principais características das nanofibras. Também foi possível verificar a capacidade de liberação controlada dos antifúngicos durante 72 h de contato das nanofibras com diferentes soluções simulantes. Valores próximos a 80 e 45 μg/mL de cetoconazol e natamicina, respectivamente, foram observados em solução de Tween 20 (5%). Portanto, o processo de eletrofiação foi capaz de agregar propriedades antifúngicas às nanofibras de PCL. Os resultados demonstraram que as bactérias e os nanomateriais investigados neste estudo são promissores para o controle de fungos toxigênicos e produção de micotoxinas. / Filamentous fungi that have the potential to produce mycotoxins may be present in food, from cultivation to after industrialization. Therefore, several strategies to control fungal growth must be investigated in order to avoid the development of these microorganisms and the production of their toxins in food. In this work, two approaches to toxigenic fungi control were evaluated. The first one was the use of bacteria from different aquatic environments as biocontrol agents in which 10 Bacillus spp. strains and the Pseudomonas sp. 4B strain were tested in relation to the effect on growth parameters (mycelial growth, sporulation and spore germination rates) of toxigenic fungi (Aspergillus and Penicillium) and mycotoxin formation. All bacteria were able to inhibit the fungal growth in culture medium with inhibition zones ranging from 1.0 to 15.7 mm. It was also observed that Bacillus sp. P11 had better results compared to other Bacillus strains with larger reduction values in most of growth parameters. Furthermore, Bacillus sp. P11 and Pseudomonas sp. 4B exhibited effect on mycelial growth, sporulation and spore germination rates with reduction values above of 43.3, 32.1 and 84.1%, respectively. Even so, the other strains also showed satisfactory results on these parameters. Finally, these bacteria reduced the synthesis of aflatoxin B1 and ochratoxin A at levels above 94 and 63%, respectively, when co-cultivated with each mycotoxin producing fungi. Additionally, the ability of Bacillus sp. P11 to produce lipopeptides such as iturin A (167.9 mg/ml of butanolic extract) and surfactin (361.9 mg/ml of butanolic extract) was confirmed. These compounds may have contributed to antifungal activity of this bacterium. The second investigation of this work in order to control the growth of toxigenic fungi was the use of poly-ε-caprolactone nanofibers incorporated with ketoconazole and natamycin as antimicrobial material. In this approach, nanofibers were produced by the electrospinning technique and subsequently characterized and evaluated for their antifungal potential. Both nanofibers functionalized with ketoconazole and natamycin showed antifungal activity against toxigenic isolates since inhibitory zones ranging from 6 to 44 mm were observed. In addition, scanning electron microscopy and infrared spectroscopy analysis showed that the antifungals incorporation does not change the characteristics of nanofibers. It was also possible to verify the ability of controlled drug release during 72 h of nanofibers contact with different simulants solutions. Values near 80 and 45 μg/ml of ketoconazole and natamycin, respectively, were observed in the solution containing 5% Tween 20. Therefore, the electrospinning process was able to provide antifungal properties to the nanofibers. The results showed that bacteria and nanomaterials investigated in this study are promising for developing control strategies of toxigenic fungi and mycotoxin production.
66

Prospecção fitoquímica de ativos em extratos e frações originados de folhas de Azadirachta indica A. JUSS. visando atividade antimicrobiana

Galeane, Mariana Cristina [UNESP] 21 June 2015 (has links) (PDF)
Made available in DSpace on 2016-02-05T18:29:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-06-21. Added 1 bitstream(s) on 2016-02-05T18:33:15Z : No. of bitstreams: 1 000856397_20161130.pdf: 266115 bytes, checksum: caadb382124cfd5f054815f9beef9f20 (MD5) Bitstreams deleted on 2016-12-02T12:25:14Z: 000856397_20161130.pdf,. Added 1 bitstream(s) on 2016-12-02T12:25:56Z : No. of bitstreams: 1 000856397.pdf: 965687 bytes, checksum: a903d9ba41cda1ac0b70fc3a764950be (MD5) Bitstreams deleted on 2016-12-02T12:41:54Z: 000856397.pdf,. Added 1 bitstream(s) on 2016-12-02T12:42:33Z : No. of bitstreams: 1 000856397.pdf: 965687 bytes, checksum: a903d9ba41cda1ac0b70fc3a764950be (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica A. Juss A. JussA. JussA. Juss . popularmente conhecida como ni . popularmente conhecida como ni . popularmente conhecida como ni . popularmente conhecida como ni. popularmente conhecida como ni. popularmente conhecida como ni . popularmente conhecida como ni. popularmente conhecida como ni . popularmente conhecida como ni. popularmente conhecida como ni . popularmente conhecida como ni m ou margosa, m ou margosa, m ou margosa, m ou margosa, m ou margosa, m ou margosa, pertence à pertence à pertence à pertence à pertence à pertence à pertence à famí famí lia Meliacea lia Meliacealia Meliacealia Meliacea lia Meliacea lia Meliacealia Meliacealia Meliacealia Meliaceae, tendotendotendo propriedades propriedades propriedadespropriedadespropriedades inseticida s e pesticidae pesticidae pesticida e pesticida e pesticidae pesticida s, sendosendosendo que que outros estudos outros estudos outros estudos outros estudos outros estudos comprovam sua eficácia como anticomprovam sua eficácia como anti comprovam sua eficácia como anti comprovam sua eficácia como anti comprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anti comprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anti comprovam sua eficácia como anticomprovam sua eficácia como anti fúngico, anti fúngico, antifúngico, anti fúngico, antifúngico, antifúngico, antifúngico, anti -inflamatório, cica inflamatório, cica inflamatório, cica inflamatório, cicainflamatório, cica trizante, antiviral, trizante, antiviral, trizante, antiviral, trizante, antiviral, trizante, antiviral, trizante, antiviral, trizante, antiviral, dentreentre outras atividades outras... / Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica A. Juss A. JussA. Juss, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or ...
67

Estudo da interação da natamicina com membranas fosfolipídicas incorporadas de esteróis

Arima, Anderson Akira [UNESP] 26 March 2014 (has links) (PDF)
Made available in DSpace on 2014-12-02T11:16:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-03-26Bitstream added on 2014-12-02T11:20:59Z : No. of bitstreams: 1 000799717.pdf: 5363634 bytes, checksum: 45ab821150f84e8881117fcb86e5e5ab (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A natamicina (pimaricina) é um antifúngico de amplo espectro de ação, o qual já vem sendo empregado tanto como conservante alimentar, como no tratamento de infecções fúngicas superficiais. Embora esse antibiótico natural venha sendo isolado a partir de bactérias do solo (streptomyces sp.) desde 1950, o seu mecanismo de ação ainda continua desconhecido. Por essa razão, neste estudo nós investigamos o efeito desse antibióticoem dois tipos de membranas modelo: filmes de Langmuir (monocamadas) e vesículas multilamelares (lipossomos). Os resultados obtidos foram correlacionados com o mecanismo de ação da natamicina em membranas biológicas. Nos estudos envolvendo monocamadas, os efeitos da natamicina sobre as propriedades mecânicas, a morfologia e a organização molecular desses sistemas foram analisados, respectivamente, através das isotermas de compreensão, microscopia de ângulo de Brewsler (BAM) e Espectroscopia de Absorção-Reflexão Infravermelha com Polarização Modulada (PM-IRRAS); ao passo que a influência da natamicina sobre a organização e as transições de fase dos lipossomos foram monitoradas através da Ressonância Paramagnética Eletrônicae da Colorimetria Diferencial de Varredura (DSC), respectivamente / Natamycin is a broad spectrum antifungal, that due to its low oral and topical absorption, it already has been used both for food preservative and in the treatment of superficial mycoses. Althrough this natural antibiotic has been from soil bacteria of genus Stremptomyces since 1950, its mechanism of action on lipid environment of biomembranes has not been investigated enough. For this reason, in this study we investigated the effects of this antibiotic on two types of lipid model membranes - Langmuir films (monolayers) and multilamelar vesicles (liposomes) - and the obtained results were correlated with its mode of action on biomembranes. For monolayer models, the effect of natamycin on their mechanical properties, morphology and molecular organization were analyzed by, respectively, surface pressure isotherms, Brewsler angle Microscopy (BAM) and Polarization-Modulation Infrared Reflection-Absorption Spectroscopy (PM-IRRAS); while the influence of natamycin on the lipid organization and the thermal properties for liposomes were characterized by, respectively, Electron Paramagnetic Resonance (EPR) and Differential Scanning Calorimetry (DSC)
68

Perfil fenotípico e de expressão de proteínas de Cryptococcus neoformans após tratamento com substâncias obtidas da planta Pterogyne nitens

Leite, Fernanda Sangalli [UNESP] 18 June 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-18Bitstream added on 2014-06-13T19:55:47Z : No. of bitstreams: 1 leite_fs_me_arafcf_prot.pdf: 3559143 bytes, checksum: 740bd3686104fc290587dc0a0352e995 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / A criptococose tem emergido como importante infecção oportunista em pacientes imunossuprimidos e imunocompetentes causando principalmente a neurocriptococose. Cryptococcus neoformans, um dos agentes, é uma levedura capsulada comumente encontrada em infecções do sistema nervoso central em pacientes HIV positivos. No mercado há fármacos para o tratamento dessas infecções, porém problemas são verificados quanto ao espectro de ação, custos e efeitos adversos. As plantas são usadas na medicina por longa data constituindo-se de uma ótima alternativa para busca de substâncias que podem ser utilizadas na formulação de novos antifúngicos. Neste estudo foram avaliados vários extratos, frações e substâncias puras do projeto BIOTA frente à cepa ATCC de C. neoformans, bem como em isolados clínicos com perfil de sensível e resistente frente ao fluconazol. Também foi feita a padronização e aplicação da metodologia do “tabuleiro de xadrez” para verificação de atividade sinérgica, aditiva, indiferente e antagônica entre as frações de plantas de interesse, bem como a molécula pedalitina associada com outras substâncias de origem vegetal e com as drogas sintéticas fluconazol e anfotericina B. Os que apresentaram melhores concentrações inibitórias mínimas... / Cryptococcosis is a disease that has emerged as an important opportunistic infection in immunocompromised and immunocompetent patients mainly causing cryptococcal meningitis. Cryptococcus neoformans, one of the agents, is encapsulated yeast most commonly found in central nervous system infections in HIV patients. There are drugs on the marketplace for the treatment of these infections, but problems are related to spectrum of action, costs and adverse effects. Plants are used in medicine for a long time and they are a great alternative to look for substances that can be used to develop new antifungal agents. In this study we evaluated several extracts, fractions and pure substances from BIOTA project against the ATCC strain of C. neoformans, as well as clinical isolates with sensible and resistant profile to fluconazole. The standardization and application of the methodology of the chessboard technique was developed to verify synergistic, additive, indifferent and antagonistic activities among the fractions of the selected plants, and the molecule pedalitin associated with other natural compounds and the synthetic drugs fluconazole and amphotericin B. The substances that presented the best minimum inhibitory concentrations were selected to verify the fungi protein profile before and after contact with the plant substance and adhesion profile to cells (pneumocytes) A549. Among the plants studied, Pterogyne nitens, specie that belongs to the family Fabaceae, which has the active substance called pedalitin, presented a significant antifungal activity against the isolates of C. neoformans including resistant. Suspensions of C. neoformans with and without treatment with fluconazole and in contact with pedalitin were analyzed by SDS-PAGE and two-dimensional electrophoresis. These treatments revealed changes in the expression... (Complete abstract click electronic access below)
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Estudo da atividade anti-Paracoccidioides do composto galato de decila : mecanismo de ação e interação fungo-hospedeiro /

Silva, Ana Carolina Alves de Paula e. January 2016 (has links)
Orientador: Maria José Soares Mendes Giannini / Coorientador: Alexandra Ivo Medeiros / Banca: Carlos Pelleschi Taborda / Banca: Sonia Rozental / Banca: Maria do Rosário Rodrigues Silva / Banca: Anderson Assunção Andrade / Resumo: O fungo do gênero Paracoccidioides é o agente etiológico da paracoccidioidomicose (PCM), micose de grande importância no Brasil e América Latina. Há diferentes terapias disponíveis, como os antifúngicos da classe dos poliênicos, azóis e sulfonamidas. O desenvolvimento de novos antifúngicos com eficácia superior é necessário para prevenir recaídas e diminuir os efeitos secundários, o período de tratamento e sequelas. A molécula de ácido gálico com diferentes modificações (galatos de alquila) apresentou atividade antifúngica contra um painel representativo de fungos patogênicos. O galato de decila (G14) foi objeto de estudo deste trabalho, para o qual a interação Paracoccidioides¬-hospedeiro foi relacionada ao mecanismo de ação. Para tanto, o fungo Paracoccidioides lutzii (Pl01) foi desafiado com o G14 para análise das alterações no desenvolvimento de brotamentos e na viabilidade celular pelo ensaio de MTT. Foi avaliada a influência do G14 na taxa de interação de Pl01 com a linhagem de macrófago alveolar murino AMJ2-C11, com as linhagens pulmonares de mamífero A549 e MRC-5, e hemócitos da larva de Galleria mellonella utilizando ensaios por citometria de fluxo. O G14 ainda foi avaliado quanto à taxa de sobrevivência da larva de G. mellonella infectada e a capacidade na modulação da produção de óxido nítrico em macrófago RAW. O estudo do mecanismo de ação foi realizado pelo ensaio de interação químico-genética seguida da interação genética, que consiste na comparação de uma coleç... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The fungus of genus Paracoccidioides is the etiological agent of paracoccidioidomycosis (PCM), an important mycosis in Brazil and Latin America. There are different available therapies, as antifungals belong to the class of polyenes, azoles and sulfonamides. The development of new antifungal agents with greater effectiveness is required to prevent relapse and reduce side effects, the period of treatment and sequelae. The gallic acid molecule with different modifications (alkyl gallates) showed antifungal activity against a representative panel of pathogenic fungi. The decyl gallate (G14) was the study object of this work, for which the Paracoccidioides-host interaction was connected with the mechanism of action. Therefore, the fungus Paracoccidioides lutzii (Pl01) was challenged with the G14 to analyze the changes in the development of budding and cell viability by MTT assay. Then, it was assessed the influence of the G14 in the interaction rate of Pl01 with murine alveolar macrophage lineage AMJ2-C11, with mammalian lung lineage A549 and MRC-5, and hemocytes of Galleria mellonella larvae using assays by flow cytometry. The compound G14 was evaluated for survival rate of infected G. mellonella larvae and to capacity of modulation of nitric oxide production in RAW macrophages. The mechanism of action was performed by chemical-genetic interaction assay followed by genetic interaction, which involves comparing a mutant collection, of Saccharomyces cerevisiae yeast, with hypersen... (Complete abstract click electronic access below) / Doutor
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Prospecção fitoquímica de ativos em extratos e frações originados de folhas de Azadirachta indica A. JUSS. visando atividade antimicrobiana /

Galeane, Mariana Cristina. January 2015 (has links)
Orientador: Luis Vitor Silva do Sacramento / Banca: Fernanda de Freitas Anibal / Banca: Tais Maria Bauab / Resumo: Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica A. Juss A. JussA. JussA. Juss . popularmente conhecida como ni . popularmente conhecida como ni . popularmente conhecida como ni . popularmente conhecida como ni. popularmente conhecida como ni. popularmente conhecida como ni . popularmente conhecida como ni. popularmente conhecida como ni . popularmente conhecida como ni. popularmente conhecida como ni . popularmente conhecida como ni m ou margosa, m ou margosa, m ou margosa, m ou margosa, m ou margosa, m ou margosa, pertence à pertence à pertence à pertence à pertence à pertence à pertence à famí famí lia Meliacea lia Meliacealia Meliacealia Meliacea lia Meliacea lia Meliacealia Meliacealia Meliacealia Meliaceae, tendotendotendo propriedades propriedades propriedadespropriedadespropriedades inseticida s e pesticidae pesticidae pesticida e pesticida e pesticidae pesticida s, sendosendosendo que que outros estudos outros estudos outros estudos outros estudos outros estudos comprovam sua eficácia como anticomprovam sua eficácia como anti comprovam sua eficácia como anti comprovam sua eficácia como anti comprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anti comprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anticomprovam sua eficácia como anti comprovam sua eficácia como anticomprovam sua eficácia como anti fúngico, anti fúngico, antifúngico, anti fúngico, antifúngico, antifúngico, antifúngico, anti -inflamatório, cica inflamatório, cica inflamatório, cica inflamatório, cicainflamatório, cica trizante, antiviral, trizante, antiviral, trizante, antiviral, trizante, antiviral, trizante, antiviral, trizante, antiviral, trizante, antiviral, dentreentre outras atividades outras... / Abstract: Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica Azadirachta indica A. Juss A. JussA. Juss, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or margosa, belongs to the family, popularly known as neem or ... / Mestre

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