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- ItemAcesso aberto (Open Access)Ação antimicrobiana de biguanidas em cistos de Acanthamoeba spp.(Universidade Federal de São Paulo (UNIFESP), 2013) Mafra, Cecilia Sales Pires [UNIFESP]; Carvalho, Fábio Ramos de Souza [UNIFESP]; http://lattes.cnpq.br/4036480252471491; http://lattes.cnpq.br/2705116825749030; Universidade Federal de São Paulo (UNIFESP)Objetivos: Avaliar o efeito antimicrobiano e citotoxico de diferentes biguanidas em cistos de Acanthamoeba spp. Metodos: Foi realizado ensaio de viabilidade celular in vitro de cistos de Acanthamoeba spp frente a duas biguanidas: polihexametileno biguanida e digluconato de clorexidina. Neste ensaio utilizou-se a cepa de Acanthamoeba castellanii ATCC 30011 e os isolados clinicos de Acanthamoeba sp, EPM-232C e EPM-244. Estes antimicrobianos foram testados individualmente ou associados e em doses e concentracoes diferentes. A viabilidade dos cistos foi medida por meio do teste de exclusao com o corante azul de tripan. Tambem foi realizado ensaio de citotoxicidade in vitro das celulas endoteliais do cordao umbilical humano cultivadas isoladamente ou em cocultura com os mesmos isolados de Acanthamoeba sp apos exposicao a uma gota de digluconato de clorexidina e de polihexametileno biguanida, isolados ou em associacao, em concentracoes de 0,04%. Placas de cultura e cocultura de celulas endoteliais do cordao umbilical humano sem exposicao aos antimicrobianos funcionaram como controle. A viabilidade celular das celulas endoteliais do cordao umbilical humano foi testada utilizando os reagentes Thiazolyl Blue Tetrazolium Bromide® e Prestoblue® apos 48 horas de incubacao. Ensaio qualitativo foi realizado com corantes laranja de acridina e iodeto de propidio. Resultados: Todas as doses, concentracoes e associacoes de biguanidas avaliadas tiveram efeito cisticida frente aos organismos testados alcancando diferenca estatistica em relacao ao controle. Nao houve diferenca entre as doses, concentracoes e associacoes testadas frente a cepa ATCC 30011 e aos isolados EPM-232C. Quanto ao efeito destas frente ao isolado clinico EPM-244, observou-se que doses e concentracoes mais altas de clorexidina e da associacao das duas biguanidas teve efeito cisticida superior. Nao houve diferenca estatistica entre as diferentes doses e concentracoes de polihexametileno biguanida. Tambem foi possivel concluir que o uso associado destas biguanidas teve efeito superior ao seu uso individual e a clorexidina teve efeito superior a biguanida. No ensaio de viabilidade celular das celulas endoteliais do cordao umbilical humano pode-se observar que quando se utilizou os antimicrobianos separadamente o efeito toxico nas celulas do cordao umbilical humano e no grupo de cocultura destas com o isolado clinico EPM-232C foi maior do que quando esses foram utilizados associados, percebendo-se que essa associacao tem um possivel efeito protetor sobre essas celulas. O digluconato de clorexidina usado isoladamente teve tendencia a toxicidade maior que o polihexametileno biguanida. Conclusoes: O uso associado de polihexametileno biguanida e digluconato de clorexidina tem maior efeito cisticida sobre algumas cepas de Acanthamoeba sp que o seu uso separado e parece causar um efeito protetor sobre celulas endoteliais do cordao umbilical humano nas concentracoes de 0,04% frente a cepas menos virulentas de Acanthamoeba sp
- ItemSomente MetadadadosAntimicrobial Action of Biguanides on the Viability of Acanthamoeba Cysts and Assessment of Cell Toxicity(Assoc Research Vision Ophthalmology Inc, 2013-09-01) Mafra, Cecilia Sales Pires [UNIFESP]; Carrijo-Carvalho, Linda Christian [UNIFESP]; Chudzinski-Tavassi, Ana Marisa; Taguchi, Felipe Marques de Carvalho [UNIFESP]; Foronda, Annette Silva [UNIFESP]; Carvalho, Fabio Ramos de Souza [UNIFESP]; Freitas, Denise de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Butantan InstPURPOSE. To assess dose- and concentration-dependent rates of biguanides on the viability of Acanthamoeba cysts isolated from severe ulcerative keratitis, and to correlate cysticidal activites with cytotoxic profiles in corneal and endothelial cells.METHODS. Cysticidal activities of polyhexamethylene biguanide and chlorhexidine digluconate were evaluated in the Acanthamoeba castellanii strain and clinical isolates of Acanthamoeba spp obtained from two severe and recurrent cases of ulcerative keratitis. the molecular characterization of protozoa used in the experimental assays was performed by sequencing reactions of the 18S rDNA gene. Acanthamoeba cysts were exposed at different dosages and concentrations of both biguanides; the application of double-biguanides was also evaluated. Automated cell viability assessment of cysts was performed using the trypan blue dye exclusion method. Cytotoxicity assays of biguanides were conducted using primary cultures of endothelial cells alone or in coculture with Acanthamoeba cysts. Human corneal epithelial cells were used as a comparative pattern to assess the toxicity of biguanide compounds. Cell viability was measured using both quantitative and qualitative methods. Statistical analyses were applied to the data.RESULTS. the in vitro study showed that all dosages, concentrations, and combinations of biguanides tested had a cysticidal effect on Acanthamoeba spp strains tested compared with control cultures not exposed to any antimicrobials; the difference in response was statistically significant. the use of both biguanides in combination demonstrated the best cysticidal effect. the use of isolated biguanides was associated with greater cytotoxic effects than with biguanides used in combination. Chlorhexidine digluconate used alone tended to have greater cytotoxicity than polyhexamethylene biguanide. Furthermore, the double-biguanide application had a statistically significant decrease in the deleterious effect on endothelial cells at higher dosage and concentration. Quantitative and qualitative analyses demonstrated the toxic effect of biguanide compounds on the viability of corneal epithelial cells, under single or in combination usage.CONCLUSIONS. We demonstrated that the combined use of biguanides had greater cysticidal activity than individual drug application as well as a possible protective effect on endothelial cells. the biguanide compounds tested were able to induce corneal epithelial cell death in time and concentration-independent fashions. Findings support the hypothesis concerning the cysticidal effect and the differential patterns of toxicity expressed by polyhexamethylene biguanide and chlorhexidine digluconate on the endothelial and corneal cells.
- ItemRestritoAvaliação do potencial patogênico e da aderência de Acanthamoeba spp. em lentes de contato esclerais(Universidade Federal de São Paulo, 2022) Pinto, Larissa Fagundes [UNIFESP]; Freitas, Denise [UNIFESP]; Farah, Ana Luisa Hofling-Lima [UNIFESP]; http://lattes.cnpq.br/7050225867972978; http://lattes.cnpq.br/4036480252471491; http://lattes.cnpq.br/4523473585685940A ceratite por Acanthamoeba é uma infecção corneana grave que tem como principal fator de risco o uso inadequado das lentes de contato. Já é comprovado que espécies do gênero Acanthamoeba spp. são capazes de aderir à superfície de uma grande variedade de lentes disponíveis, contudo, não há relatos na literatura sobre a aderência destas amebas à superfície de lentes de contato esclerais, visto que casos de ceratite associados ao uso destas lentes vêm sendo relatados. Desse modo, esse estudo teve como objetivo averiguar a aderência de diferentes isolados de Acanthamoeba spp. à superfície de lentes esclerais, investigando se o desenho das lentes e diferentes perfis de patogenicidade dos isolados poderiam influenciar poderiam influenciar nesta aderência. Para isso, três isolados de Acanthamoeba spp. foram utilizados: A. polyphaga (ATCC CDC:V062), A. polyphaga (ATCC 30461) e uma amostra clínica (obtida de um caso de ceratite por Acanthamoeba). Também cinco lentes de contato foram testadas: lente silicone-hidrogel (controle), duas lentes esclerais (uma com tratamento de superfície composto por Plasma O2 e a outra por Plasma O2 com Hydra-PEG), e duas lentes planas (com o mesmo tratamento das lentes esclerais respectivamente). As amebas aderidas à superfície das lentes foram observadas por microscopia óptica de luz e microscopia eletrônica de varredura. Também foram avaliadas as superfícies das lentes quanto a possíveis alterações que favorecessem a aderências das amebas. Tanto o isolado clínico quanto o isolado ATCC 30461 exibiram um perfil de exibiram um perfil de patogenicidade superior (crescimento e encistamento) em relação ao isolado ATCC CDC:V062. Ainda, todos os isolados aderiram mais à superfície das lentes esclerais quando comparados às lentes planas. Na microscopia eletrônica de varredura foram observadas dobras na superfície das lentes e, também, notou-se que os isolados apresentavam aspecto ameboide e alongado na superfície das lentes silicone-hidrogel (controle), e arredondado e encolhido na superfície das lentes esclerais. Os dados obtidos neste estudo sugerem que existe uma correlação estatisticamente positiva entre aderência e desenho da lente, assim como de isolados mais virulentos e aderência em lentes esclerais. Novos estudos são necessários visando atenção para o cuidado de lentes esclerais no sentido de retirar Acanthamoeba aderidas em sua superfície, quer seja por ação mecânica ou química. Urge, também, o desenvolvimento de sistemas inovadores de eliminação de parasitas e outros microrganismos das lentes de contato e parafernália.
- ItemAcesso aberto (Open Access)Ceratite microbiana: uma revisão sistemática do perfil etiológico global entre 1999 e 2019(Universidade Federal de São Paulo, 2021-02-25) Nunes, Pedro Henrique Soares [UNIFESP]; Höfling-Lima, Ana Luisa [UNIFESP]; Rocchetti, Talita Trevizani; http://lattes.cnpq.br/5137065156861712; http://lattes.cnpq.br/7050225867972978; http://lattes.cnpq.br/6538565455381055; Universidade Federal de São Paulo - UNIFESPA ceratite microbiana é uma infecção ocular que acomete a córnea e oferece riscos à visão, podendo ser causada por bactérias, fungos e protozoários. Atualmente, é uma importante causa de cegueira e baixa visão no mundo. Este estudo apresenta uma revisão acerca do perfil etiológico de ceratite microbiana em três continentes, ao longo de um período de 20 anos. Os artigos foram pesquisados em bases de dados de literatura médica e selecionados com base em critérios previamente estabelecidos. Os dados dos artigos selecionados foram extraídos de cada artigo e estatisticamente analisados. A predominância de bactérias como agentes etiológicos foi observada em todos os continentes, sendo fungos o segundo principal organismo relacionado à ceratite microbiana em todos os continentes, com marcante representatividade no continente asiático. Protozoários do gênero Acanthamoeba figuram o terceiro lugar em número de casos. Bactérias Gram-positivas dos gêneros Staphylococcus e Streptococcus representam a maior parte dos isolados bacterianos. Pseudomonas aeruginosa foi a principal espécie Gram-negativa isolada em todos os continentes. Fungos filamentosos dos gêneros Fusarium e Aspergillus, representam a maior parte dos isolados fúngicos, com exceção do continente europeu, onde leveduriformes do gênero Candida foram os principais isolados. Os resultados apresentados corroboram a noção atual de que bactérias são os principais patógenos em casos de ceratite microbiana, bem como a predominância de Gram-positivos e a expressividade nos números da espécie Gram-negativa P. aeruginosa. Além disso, os resultados alinham-se com a noção que a etiologia da ceratite fúngica está relacionada com características geográficas.
- ItemAcesso aberto (Open Access)Contact lens-associated microbial keratitis(Conselho Brasileiro de Oftalmologia, 2008-12-01) Moriyama, Aline Silveira [UNIFESP]; Hofling-Lima, Ana Luisa [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)PURPOSE: Contact lens-associated microbial keratitis is a severe condition with sight-threatening potential and increasing incidence. Information regarding the etiological agents is essential in guiding management and may vary geographically. The aim of this study was to analyze the microbiological results of corneal scrapings collected from patients presenting with contact lens-associated microbial keratitis. METHODS: Retrospective analysis of the records of all patients who were clinically diagnosed with contact lens-associated microbial keratitis and had corneal scrapings sent to the Laboratory of Ocular Microbiology, UNIFESP/EPM during a 5-year period from January 2002 to December 2007. RESULTS: The etiological agent was identified in 239 patients. Bacterial isolates accounted for 166 (69.46%) cases, Acanthamoeba for 95 (39.75%) cases and fungi for 4 (1.67%) cases. Among the bacterial infections, coagulase-negative Staphylococcus was demonstrated in 74 cases, while Pseudomonas spp was found in 32 patients. All coagulase negative Staphylococcus and Pseudomonas were susceptible to ciprofloxacin and ofloxacin. Resistance to gentamicin was documented in a single case of Pseudomonas. Fourth-generation flouoroquinolone resistance was not observed among Pseudomonas cases. CONCLUSION: Coagulase-negative Staphylococcus was the most frequent isolate, and such data must be considered when determining empiric treatment. Second-generation fluoroquinolones ciprofloxacin and ofloxacin and fourth-generation fluoroquinolones moxifloxacin and gatifloxacin showed a good antibacterial profile and therefore could be good options for initial management.
- ItemSomente MetadadadosContribuição ao estudo da susceptibilidade de acanthamoeba spp a diferentes métodos de desinfecção de lentes de contacto gelatinosas(Universidade Federal de São Paulo (UNIFESP), 1988) Freitas, Denise de [UNIFESP]; Belfort, Rubens Junior [UNIFESP]
- ItemSomente MetadadadosCytotoxic activity and degradation patterns of structural proteins by corneal isolates of Acanthamoeba spp(Springer, 2015-01-01) Sant'ana, Viviane Peracini [UNIFESP]; Carrijo-Carvalho, Linda Christian [UNIFESP]; Foronda, Annette Silva [UNIFESP]; Chudzinski-Tavassi, Ana Marisa; Freitas, Denise de [UNIFESP]; Souza de Carvalho, Fabio Ramos [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Butantan InstProteolytic enzymes secreted by trophozoites (amoebic secretome) are suggested as the main virulence factor involved in the severity of Acanthamoeba keratitis. the degradation profile of the main glycoprotein components of anterior and posterior portions of the cornea and the cytopathic effect of secretomes on endothelial cells by contact-independent mechanism were evaluated.Trophozoites were isolated primarily from corneal tissue samples (n = 11) and extracellular proteins were collected from axenic cell culture supernatants. the molecular weights of proteolytic enzymes were estimated by zymography. Enzymatic cleavage of laminin and fibronectin substrates by amoebic secretome was investigated and cluster analysis was applied to the proteolysis profiles. Primary cultures of endothelial cells were used in both qualitative and quantitative assays of cytophatogenicity.Differential patterns of proteolysis were observed among the Acanthamoeba secretomes that were analysed. the uniformity of laminin degradation contrasted with the diversity of the proteolysis profiles observed in the fibronectin substrate. Acanthamoeba secretome extracted from four clinical isolates was shown to be toxic when in contact with the endothelial cell monolayer (p < 0.01). Induction of apoptosis and membrane permeability, at different percentual values, were suggested as the main mechanisms that could induce endothelial cell death when in contact with amoebic secretome.Our results provide evidence that virulence factors secreted by Acanthamoeba trophozoites can be related to an increased pathogenicity pattern by an independent contact-trophozoite mechanism, through induction of endothelial cell death by apoptosis at a higher percentage than providing the lack of cell viability by the membrane-associated pore-forming toxin activity.
- ItemAcesso aberto (Open Access)Expressão gênica de células da córnea submetidas à infecção por acanthamoeba Spp(Universidade Federal de São Paulo (UNIFESP), 2018-06-28) Sant'Ana, Viviane Peracini [UNIFESP]; Carvalho, Fabio Ramos de Souza [UNIFESP]; http://lattes.cnpq.br/1910912718767159; http://lattes.cnpq.br/9578890417214515; Universidade Federal de São Paulo (UNIFESP)Objective: The present research project proposes: 1) to analyze the proteolytic degradation of the main substrates present in the cornea (collagen, fibronectin, laminin and tubulin) with the Acanthamoeba exoproteome; 2) to analyze the cytotoxicity of the Acanthamoeba exoproteome of in HUVEC cells in 11 clinical isolates and which its main mechanism of induction of cell death; 3) to identify by benzamidinesepharose purification of the serine protease class; 4) to characterize the Acanthamoeba exoproteome at different pHs and temperatures; 5) to analyze the susceptibility of the Acanthamoeba exoproteome with diamidines and enzymatic inhibitors. Methods: Primary cultures of trophozoites were obtained by corneal scraping of patients with Acanthamoeba spp. Analysis of the Acanthamoeba exoproteome was performed by zymography (SDSPAGEgelatin), 0.01% gelatin polyacrylamide gel was prepared according to the subunits of its substrates: Fibronectin, Laminin and Tubulin. The HUVECs were cultured in a humid oven at 37 ° C to 5% CO2 in RPMI culture medium supplemented with 10% fetal bovine serum. The proteolysis assay of type I collagen was carried out by the hydrolysis of type I collagen, at a concentration of 0.4 mg / ml, previously dialyzed in specific buffer (50 mM TrisHCl, pH 7.5, 150 mM NaCl). In the analysis of the characterization of the Acanthamoeba exoproteome in different buffers of pHs and at different temperatures where each clinical isolate was removed from the gel and placed at different pHs (pHs 2.0 12.0). The diamidines used were 0.1% Brolene and 0.1% Désomédine, also 0.1 mM PMSF and 215 μM Trasylol enzyme inhibitors were used. Results: The proteolytic profile of Acanthamoeba exoproteome is associated with severity of infection observed in the patient. The degradation of type I collagen by the Acanthamoeba exoproteome the laboratory results corroborate with the clinical aspect observed in patients with moderate and severe amoebic keratitis. In the cytotoxicity assay, in vitro results from the Acanthamoeba exoproteome with HUVEC suggest the contact independence of trophozoite to induce cell death by apoptosis. We were able to demonstrate by in vitro protein assays, whose results prospect the mechanisms of gene expression in corneal cells, the functional aspects of different amoebic exoproteomes associated with healing and regeneration, whose processes are mainly mediated via cellular signaling in the host. Affinity chromatography demonstrated the prevalence of proteolytic enzymes of the class of serine proteases contained in the protozoan exoproteome. In the proteolysis assays of the Acanthamoeba exoproteome at different pH conditions and at different temperatures, it showed strong resistance to different pH and temperature conditions where they were evaluated in the period of 4 and 16 hours, where the optimum temperature was 35 ° C and 37 ° C in pH 7.0 appropriate conditions for the pathophysiology of amoebic keratitis. In the experiment with the diamidines, we noticed that unlike propamidine, hexamidine was not able to totally inhibit the enzymatic activity of the exoproteome. Conclusions: Exoproteome produced by Acanthamoeba spp trophozoites consists of a large diversity of enzymes, with emphasis on the enzymes belonging to the class of serine proteases. The enzymatic activity contained in the different amoebic exoproteomes suggests an important influence on the mechanisms of gene expression, with emphasis on the production of extracellular matrix compounds by corneal cells. The exoproteomes may present a pattern of physical and chemical resistance associated with enzymatic activity. The enzymatic constituents of different amoebic exoproteomes express proteins capable of degrading the main type I collagen and glycoproteins present in the cornea, besides inducing cell death by contact independent apoptosis. Laboratory isolation followed by amoebic exoproteome analysis demonstrates the importance of translational research associated with the present study, since the enzymatic constituents secreted by the protozoan can induce cell death and interferes in the synthesis of extracellular matrix compounds linked to the healing and regeneration processes tissue. Consequently, mechanisms associated with gene expression in epithelial cells and keratocytes can be inactivated, prospecting worsening in the clinical pattern of the patient.
- ItemAcesso aberto (Open Access)Random amplified polymorphic DNA profiles as a tool for the characterization of Brazilian keratitis isolates of the genus Acanthamoeba(Associação Brasileira de Divulgação Científica, 2000-01-01) Alves, J.m.p.; Gusmão, C.x.; Teixeira, M.m.g.; Freitas, Denise de [UNIFESP]; Foronda, A.s.; Affonso, H.t.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)The genus Acanthamoeba comprises free-living amebae identified as opportunistic pathogens of humans and other animal species. Morphological, biochemical and molecular approaches have shown wide genetic diversity within the genus. In an attempt to determine the genetic relatedness among isolates of Acanthamoeba we analyzed randomly amplified polymorphic DNA (RAPD) profiles of 11 Brazilian isolates from cases of human keratitis and 8 American type culture collection (ATCC) reference strains. We found that ATCC strains belonging to the same species present polymorphic RAPD profiles whereas strains of different species show very similar profiles. Although most Brazilian isolates could not be assigned with certainty to any of the reference species, they could be clustered according to pattern similarities. The results show that RAPD analysis is a useful tool for the rapid characterization of new isolates and the assessment of genetic relatedness of Acanthamoeba spp. A comparison between RAPD analyses and morphological characteristics of cyst stages is also discussed.
- ItemAcesso aberto (Open Access)Serine-like proteolytic enzymes correlated with differential pathogenicity in patients with acute Acanthamoeba keratitis(Wiley-Blackwell, 2011-04-01) Souza Carvalho, F. R. de [UNIFESP]; Carrijo-Carvalho, L. C.; Chudzinski-Tavassi, A. M.; Foronda, Annette Silva [UNIFESP]; Freitas, D. de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)P>Acute ocular infection due to free-living amoebae of the genus Acanthamoeba is characterized by severe pain, loss of corneal transparency and, eventually, blindness. Proteolytic enzymes secreted by trophozoites of virulent Acanthamoeba strains have an essential role in the mechanisms of pathogenesis, including adhesion, invasion and destruction of the corneal stroma. in this study, we analysed the relationship between the extracellular proteases secreted by clinical isolates of Acanthamoeba and the clinical manifestations and severity of disease that they caused. Clinical isolates were obtained from patients who showed typical symptoms of Acanthamoeba keratitis. Trophozoites were cultivated axenically, and extracellular proteins were collected from cell culture supernatants. Secreted enzymes were partially characterized by gelatin and collagen zymography. Acanthamoeba trophozoites secreted proteases with different molecular masses, proteolysis rates and substrate specificities, mostly serine-like proteases. Different enzymatic patterns of collagenases were observed, varying between single and multiple collagenolytic activities. Low molecular weight serine proteases were secreted by trophozoites associated with worse clinical manifestations. Consequently, proteolytic enzymes of some Acanthamoeba trophozoites could be related to the degree of their virulence and clinical manifestations of disease in the human cornea.
- ItemAcesso aberto (Open Access)Toxicidade de corticoides e biocidas em células da córnea: pesquisa translacional reversa e medicina de precisão em oftalmologia e ciências visuais(Universidade Federal de São Paulo (UNIFESP), 2016-08-30) Roizenblatt, Marina [UNIFESP]; Carvalho, Fábio Ramos de Souza [UNIFESP]; http://lattes.cnpq.br/1910912718767159; http://lattes.cnpq.br/2958911741191259; Universidade Federal de São Paulo (UNIFESP)INTRODUCTION: Human Corneal Epithelial Cells (HCEC) and Statens Seruminstitut Rabbit Cornea (SIRC) reproduce the cornea microenvironment in terms of epithelium and stroma, respectively. These cells are ideal for the study of the pathophysiology of the Acanthamoeba keratitis (AK) in vitro. . As there is no standartized treatment for AK, it is important to develop a study model for this condition. In addition, considerable toxicity has been reported with the use of antimicrobial compounds such as biguanides and diamidines, associated or not to corticosteroids, for the management of AK. OBJECTIVES. To study the in vitro the effect of isolated corticosteroids or associated with Polyhexamethylene Biguanide (PHMB) in a cell model of the corneal epithelium and stroma. MATERIALS AND METHODS. Cells of HCEC or SIRC were seeded into plates in the concentration of 2 x 105/mL and treated with the addition of corticosteroid (dexamethasone 0.1% or prednisolone 1.0%) or PHMB at the concentration of 0.02% or 0.04%, alone or associated with one of the above mentioned corticosteroids. Cell metabolism were quantified by fluorescence with the aid of PrestoBlueTM RESULTS. Metabolism did not differ between HCEC and SIRC after 6 hours and in the recovery period, in which cells were incubated without the chemical compounds 9 (p<0,01). The metabolic rate of recovery increased in the PHMB 0.02% plus pednisolone condition for HCEC and PHMB 0.04% plus dexamethasone for SIRC (p<0,05). Media supplemented with prednisone or dexamethasone showed to be less toxic than PHMB in any concentration, alone or in association to corticosteroids (p<0,01). DISCUSSION. The literature lacks objective data on the ocular toxicity of PHMB and / or corticosteroids in the treatment of CA. It has been demonstrated that the toxicity of PHMB is higher than that of steroids to cells of the epithelium and corneal stroma at an experimental environment, and that the combination of the two medications did not improve the condition. After removal of the drugs from the culture medium, it was observed a cellular metabolism recovery. CONCLUSIONS. This study demonstrates that the addition of corticosteroids does not change considerably the toxicity of PHMB to the corneal cells. Notwithstanding, PHMB 0.02% is preferable in cases of combined therapy for AK.
- ItemSomente MetadadadosTwenty Years of Acanthamoeba Keratitis(Lippincott Williams & Wilkins, 2009-06-01) Carvalho, Fabio Ramos de Souza [UNIFESP]; Foronda, Annette Silva [UNIFESP]; Mannis, M. J.; Hoefling-Lima, Ana Luisa [UNIFESP]; Belfort, R. [UNIFESP]; Freitas, Denise de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP); Univ Calif DavisPurpose: We described the rate of Acanthamoeba keratitis (AK) in a referral eye center in Sao Paulo, Brazil, through a retrospective review of clinical and laboratorial records of patients over 2 decades.Methods: From 1987 to 2006, a total of 581 requests for amoebic laboratory workup in cases of infections keratitis were investigated. Statistical analyses were applied to analyze a tendency of AK cases.Results: Acanthamoeba species were cultured from corneal scrapings of 185 patients, 5 of them with bilateral infection. Eighty-three percent of those patients were related with contact lens wear.Conclusions: The results suggested that patients with AK have persisted and increased over time at our ophthalmology center. Contact lenses showed to be a potential risk factor. Amoebic corneal infection can be considered as a new but well-established disease ill Brazilian ophthalmology and visual sciences.