Navegando por Palavras-chave "Epitélio anterior"
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- ItemSomente MetadadadosEfeito do hialuronato de sódio na migração e proliferação do epitélio de córnea humana.(Universidade Federal de São Paulo (UNIFESP), 2000) Gomes, José Álvaro Pereira [UNIFESP]; Campos, Mauro Silveira de Queiroz [UNIFESP]Introdução: O hialuronato de sódio (HS) e um constituinte da matriz extracelular, que parece estimular a migração, adesão e proliferação epitelial corneal em coelhos. No entanto, controversias ainda persistem sobre os mecanismos da acao do HS nestas funcoes. Objetivos: Avaliar o efeito do HS exogeno na migracao e proliferacao das celulas epiteliais corneais humanas cultivadas in vitro; avaliar se a presenca do HS exogeno altera a expressao do receptor do HS, CD44, nessas celulas e avaliar inducao de apoptose celular pelo HS. Material e Metodos: Tres culturas de celulas epiteliais (n=l7) de diferentes corneas humanas foram selecionadas e separadas aleatoriamente para receber: 1. meio de cultura com HS diluido a O,6mg/ml; 2. meio enriquecido com hidroxipropilmetilcelulose (HM) 2,5mg/ml para obter viscosidade semelhante a do HS utilizado e 3. apenas meio de cultura (Controle). As culturas foram avaliadas por microscopia invertida por um observador mascarado. Medidas de area de crescimento foram obtidas para determinar migracao epitelial nos dias 4, 8, 12 e 16. Repetiu-se o primeiro experimento e, ao final do 16§ dia, celulas epiteliais dos grupos HS, HM e Controle de corneas diferentes (n=5) foram suspensas e enviadas para avaliacao de proliferacao por citometria de fluxo, pelo uso de iodeto de propidium (IP) e por imunohistoquimica, utilizando-se o anticorpo Ki-67 (n=6); avaliacao imunohistoquimica para deteccao de CD44 (n=5) e teste de apoptose, utilizando o corante Hoechst (n=6). As comparacoes entre os 3 grupos de estudo foram realizadas pela ANOVA para medidas repetidas para migracao e teste de Friedman pa ra proliferacao por IP e Ki-67, receptor CD44 e apoptose. Resultados: A analise da area de migracao epitelial das culturas dos grupos HS, HM e Controle mostrou que, no dia 12, o grupo HS apresentou valores de migracao significantemente diferentes dos grupos HM (p=O,OO7) e Controle (p=O,O25). No dia 16, os tres grupos foram significantemente diferentes entre si (HS X Controle: p=O,OOl; HM X Controle: p=0,OlO e HS X HM: p=O,OO3). As proliferacoes celulares com IP e com Kl67 nao evidenciaram diferenca significante entre HS, HM e Controle (p=O,819 e p=O,957, respectivamente). As avaliacoes do CD44 e de apoptose tambem nao mostraram diferencas significantes entre os 3 grupos de estudo (p=O,819 para ambos). Conclusoes: O HS exogeno estimula a migracao das celulas epiteliais corneais humanas cultivadas in vitro. Por outro lado, HS nao...(au)
- ItemSomente MetadadadosEvolução do uso de células-tronco na reconstrução da superfície ocular(Universidade Federal de São Paulo (UNIFESP), 2008) Gomes, José Álvaro Pereira [UNIFESP]
- ItemAcesso aberto (Open Access)Gene transfer to primary corneal epithelial cells with an integrating lentiviral vector(Conselho Brasileiro de Oftalmologia, 2010-10-01) Oliveira, Lauro Augusto De [UNIFESP]; Kim, Charles; Sousa, Luciene Barbosa De [UNIFESP]; Schwab, Ivan R.; Rosenblatt, Mark I.; Universidade Federal de São Paulo (UNIFESP); University of California Department of Ophthalmology and Visual Science; Weill Cornell Medical College Department of OphthalmologyPURPOSE: To evaluate the transfer of heterologous genes carrying a Green Fluorescent Protein (GFP) reporter cassette to primary corneal epithelial cells ex vivo. METHODS: Freshly enucleated rabbit corneoscleral tissue was used to obtain corneal epithelial cell suspension via enzymatic digestion. Cells were plated at a density of 5×10³ cells/cm² and allowed to grow for 5 days (to 70-80% confluency) prior to transduction. Gene transfer was monitored using fluorescence microscopy and fluorescence activated cell sorter (FACS). We evaluated the transduction efficiency (TE) over time and the dose-response effect of different lentiviral particles. One set of cells were dual sorted by fluorescence activated cell sorter for green fluorescent protein expression as well as Hoechst dye exclusion to evaluate the transduction of potentially corneal epithelial stem cells (side-population phenotypic cells). RESULTS: Green fluorescent protein expressing lentiviral vectors were able to effectively transduce rabbit primary epithelial cells cultured ex vivo. Live cell imaging post-transduction demonstrated GFP-positive cells with normal epithelial cell morphology and growth. The transduction efficiency over time was higher at the 5th post-transduction day (14.1%) and tended to stabilize after the 8th day. The number of transduced cells was dose-dependent, and at the highest lentivirus concentrations approached 7%. When double sorted by fluorescence activated cell sorter to isolate both green fluorescent protein positive and side population cells, transduced side population cells were identified. CONCLUSIONS: Lentiviral vectors can effectively transfer heterologous genes to primary corneal epithelial cells expanded ex vivo. Genes were stably expressed over time, transferred in a dose-dependence fashion, and could be transferred to mature corneal cells as well as presumable putative stem cells.
- ItemAcesso aberto (Open Access)Transplante de células-tronco epiteliais límbicas alógenas expandidas ex vivo sobre membrana amniótica: relato de caso(Conselho Brasileiro de Oftalmologia, 2009-04-01) Gomes, José Álvaro Pereira [UNIFESP]; Pazos, Henrique Santiago Baltar; Silva, André Berger Emiliano; Cristovam, Priscila Cardoso [UNIFESP]; Belfort, Rubens Junior [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Instituto Suel Abujamra Setor de Segmento Anterior; ISA Setor de Segmento AnteriorCase report of a patient who developed failure of an allogenic living related conjunctival limbal transplantation in the right eye after an episode of epidemic keratoconjunctivitis. After a few months, she underwent transplantation of allogenic limbal epithelial stem cells cultivated ex vivo on amniotic membrane (first case in Brazil). The patient evolved with total corneal epithelialization and improvement of the visual acuity. Three months after the surgery, peripheral superficial neovascularization with worsening of the corneal transparency was observed. The vision remained 0.1 after one year of the transplantation.
- ItemAcesso aberto (Open Access)Transplante de membrana amniótica em casos agudos graves de queimadura ocular química e síndrome de Stevens-Johnson(Conselho Brasileiro de Oftalmologia, 2009-04-01) Ricardo, José Reinaldo da Silva [UNIFESP]; Barros, Sabrina Leite de [UNIFESP]; Santos, Myrna Serapião dos [UNIFESP]; Souza, Luciene Barbosa de [UNIFESP]; Gomes, José Álvaro Pereira [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)PURPOSE: To study the therapeutic potential of amniotic membrane transplantation in cases of severe acute chemical ocular burn and Stevens-Johnson syndrome. METHODS: We retrospectively reviewed the records of eight patients, with a total of ten eyes, submitted to amniotic membrane transplantation for treatment of ocular chemical burns and Stevens-Johnson syndrome in the acute phase between January 1999 and May 2008 in the Ophthalmology Department of UNIFESP. Data relating to sex, age, degree of chemical burns, etiology, affected eye, ophthalmological findings, extension of amniotic membrane, surgeries, additional time between the injury and surgery in days, visual acuity before and after surgery, epithelial defect healing (days), complications and time of follow-up in months were collected. RESULTS: The average age of patients was 35.7 ± 23.04 years, with six men and two women. Three patients (four eyes) had Stevens-Johnson syndrome and five patients (six eyes) had chemical ocular burn. The epithelial defect was healed at an average of 27.8 ± 4.7 days (ranging from 20 and 35 days). All patients presented limbal stem cell deficiency in a median follow-up of 7.8 ± 2.8 months (ranging from six and twelve months) and four eyes developed symblepharon. CONCLUSIONS: The results suggest that the amniotic membrane transplantation represents an additive that can be carried out in the serious cases of ocular chemical burn and Stevens-Johnson syndrome with the finality of promoting the epithelialization and abolishing the inflammation and its consequences, if compared with other studies that treated similar cases with medical therapy only. On the other hand, it is not possible to avoid the limbic deficiency in these cases, which in the future will need limbal stem cell transplantation or other surgeries for correction of the ocular surface.