RESUMEN
PURPOSE: To evaluate the safety and potential healing efficacy of the topical ocular administration of a gelatin membrane containing usnic acid/liposomes (UALs) for corneal cicatrization. UALs have shown healing activity in animal models of dermal burn lesions. We evaluated the safety of topical ocular administration of UAL and its potential healing efficacy as an ophthalmic treatment on chemical lesions in rabbit eyes. METHOD: The Draize test was used to check for ocular toxicity and the score was zero at each observation, indicating the ocular safety of a gelatin membrane containing usnic acid/liposome. Its potential healing efficacy as an ophthalmic treatment on chemical lesions in rabbit eyes was also assessed. RESULTS: After epithelial removal and treatment with UAL, there was a 49.4 % reduction in injury under in vivo conditions compared with a 36.6 % reduction in the control, a gelatin membrane containing liposome without usnic acid. Histological analysis of ocular surface chemical injury-tissue sections after treatment with UAL supported these observations. The corneal expression of VEGF and TGF-ß1increased by 70 % and 50 % respectively following treatment with UAL gelatin membrane. CONCLUSION: These results indicate the potential therapeutic application of UAL gelatin membranes as an ophthalmic treatment that may be used for corneal cicatrization.
Asunto(s)
Benzofuranos/administración & dosificación , Cicatriz/tratamiento farmacológico , Córnea/efectos de los fármacos , Sistemas de Liberación de Medicamentos , Cicatrización de Heridas/efectos de los fármacos , Administración Oftálmica , Animales , Benzofuranos/química , Pollos , Córnea/irrigación sanguínea , Femenino , Gelatina/administración & dosificación , Gelatina/química , Liposomas/administración & dosificación , Liposomas/química , Neovascularización Fisiológica/efectos de los fármacos , Soluciones Oftálmicas/químicaRESUMEN
Purpose: The objective of this study was to describe the short-term results of allogenic transplantation of limbal stem cells expanded on amniotic membrane for the ocular surface reconstruction. Methods: Prospective nonrandomized, nonmasked study in a single ophthalmological center. Ten patients with bilateral total limbal stem cell deficiency (LSCD) were included. Expression and presence of ABCB5 and Δp63α in amniotic membrane-cultured limbal epithelial stem cells were analyzed, in relationship with clinical changes after allogenic transplantation. An objective evaluation was performed to determine corneal transparency and superficial vascularization. Results: In a median follow-up time of 11.6 months, 7 patients (70%) were considered as failure compared with the preoperative status. ABCB5 and Δp63α are expressed in similar amount in the limbal epithelial cells expanded in vitro and transplanted in patients with bilateral LSCD. Conclusions: Transplantation of allogenic epithelial limbal cells expanded in amniotic membrane could be considered in patients with LSCD due to burns or congenital etiologies such as aniridia, but its benefit is limited for patients with immunologic diseases.
Asunto(s)
Amnios/trasplante , Enfermedades de la Córnea/etiología , Epitelio Corneal/trasplante , Limbo de la Córnea/patología , Células Madre/citología , Trasplante Homólogo/métodos , Subfamilia B de Transportador de Casetes de Unión a ATP/metabolismo , Adolescente , Adulto , Amnios/citología , Amnios/metabolismo , Aniridia/complicaciones , Estudios de Casos y Controles , Córnea/irrigación sanguínea , Córnea/metabolismo , Enfermedades de la Córnea/diagnóstico , Enfermedades de la Córnea/metabolismo , Enfermedades de la Córnea/cirugía , Lesiones de la Cornea/complicaciones , Epitelio Corneal/anomalías , Epitelio Corneal/citología , Epitelio Corneal/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Limbo de la Córnea/citología , Limbo de la Córnea/metabolismo , Masculino , México/epidemiología , Persona de Mediana Edad , Ensayos Clínicos Controlados no Aleatorios como Asunto/métodos , Estudios Prospectivos , Trasplante de Células Madre/efectos adversos , Células Madre/metabolismo , Células Madre/patología , Factores de Transcripción/metabolismo , Resultado del Tratamiento , Proteínas Supresoras de Tumor/metabolismo , Adulto JovenRESUMEN
PURPOSE:: To establish and compare protocols of alkaline cauterization for inducing corneal angiogenesis in murine models. METHODS:: Twenty-four adult Wistar rats were distributed into four groups (G1, G2, G3, and G4). The right eye cornea from each rat was cauterized using filter paper (3 mm), soaked in a solution of silver and potassium nitrates (3:1). Cauterization times were 10 (G1 and G4), or 20 seconds (G2 and G3). Cauterized corneas were washed with Ringer's lactate solution. The filter paper was either removed before washing (G1 and G2), or kept on the corneas (G3 and G4). Corneas were photographed at multiple time points (2, 4, 6, 8, 11, 13, and 15 days after the procedure), and neovascularization parameters were assayed. RESULTS:: Neovascularization was observed in 66% of G1 corneas, and 100% of G2, G3, and G4 corneas. On day 15, G1 corneas showed smaller vascularized areas (12.63 ± 12.59%) compared to those in the G3 (41.95 ± 17.32%) and G4 (33 ± 11.74%) (P < 0.05) groups. CONCLUSIONS:: The silver and potassium nitrate solution effectively induced corneal angiogenesis. The G2, G3, and G4 protocols showed excellent reproducibility, and induced vascularization in 100% of corneas.
Asunto(s)
Cauterización/métodos , Neovascularización de la Córnea/etiología , Modelos Animales de Enfermedad , Neovascularización Patológica/etiología , Nitratos , Compuestos de Potasio , Plata , Animales , Córnea/irrigación sanguínea , Córnea/cirugía , Masculino , Ratas Wistar , Valores de Referencia , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
Abstract Purpose: To establish and compare protocols of alkaline cauterization for inducing corneal angiogenesis in murine models. Methods: Twenty-four adult Wistar rats were distributed into four groups (G1, G2, G3, and G4). The right eye cornea from each rat was cauterized using filter paper (3 mm), soaked in a solution of silver and potassium nitrates (3:1). Cauterization times were 10 (G1 and G4), or 20 seconds (G2 and G3). Cauterized corneas were washed with Ringer's lactate solution. The filter paper was either removed before washing (G1 and G2), or kept on the corneas (G3 and G4). Corneas were photographed at multiple time points (2, 4, 6, 8, 11, 13, and 15 days after the procedure), and neovascularization parameters were assayed. Results: Neovascularization was observed in 66% of G1 corneas, and 100% of G2, G3, and G4 corneas. On day 15, G1 corneas showed smaller vascularized areas (12.63 ± 12.59%) compared to those in the G3 (41.95 ± 17.32%) and G4 (33 ± 11.74%) (P < 0.05) groups. Conclusions: The silver and potassium nitrate solution effectively induced corneal angiogenesis. The G2, G3, and G4 protocols showed excellent reproducibility, and induced vascularization in 100% of corneas.
Asunto(s)
Animales , Masculino , Cauterización/métodos , Neovascularización de la Córnea/etiología , Compuestos de Potasio , Modelos Animales de Enfermedad , Neovascularización Patológica/etiología , Nitratos , Valores de Referencia , Factores de Tiempo , Reproducibilidad de los Resultados , Ratas Wistar , Córnea/cirugía , Córnea/irrigación sanguíneaRESUMEN
PURPOSE: Corneal neovascularisation (CNV), with consequent loss of transparency, is due to an imbalance of proangiogenic factors. Cell-surface nucleolin (NCL) has been associated with neo-angiogenesis. There are studies identifying NCL translocation from nucleus to the cell surface, which is essential for endothelial cell proliferation. To find the possible role of NCL in the generation of corneal neovessels, the aim of this study is to characterise the NCL presence and cell-localisation in non-injured corneas, as well as to describe the changes in NCL cell and tissue localisation in CNV, and to analyse the effect of bevacizumab on NCL cellular and tissular distribution. METHODS: Suture-induced CNV was performed in mice. The corneal tissues were obtained and the histological and co-immunofluorescence assays were performed using different proteins, such as CD31, cadherin and isolectin B4. To determine the possible role of VEGF in NCL presence and localisation in our CNV model, bevacizumab was concomitantly used. RESULTS: Nucleolin was principally observed in the nucleus of the basal epithelial cells of normal corneas. Interestingly, angiogenesis-induced changes were observed in the localisation of NCL, not only in tissue but also at the cellular level where NCL was extranuclear in epithelial cells, stromal cells and neovessels. In contrast, these changes were reverted when bevacizumab was used. Besides, NCL was able to stain only aberrant corneal neovessels in comparison with retinal vessels. CONCLUSIONS: NCL mobilisation outside the nucleus during angiogenesis could have a possible role as a proangiogenic molecule in the corneal tissue.
Asunto(s)
Córnea/metabolismo , Neovascularización de la Córnea/metabolismo , Fosfoproteínas/biosíntesis , Proteínas de Unión al ARN/biosíntesis , Animales , Córnea/irrigación sanguínea , Córnea/patología , Neovascularización de la Córnea/diagnóstico , Modelos Animales de Enfermedad , Ratones , Ratones Endogámicos BALB C , Proteínas Nucleares , Conejos , NucleolinaRESUMEN
RESUMO Objetivo: Estudar botões corneanos humanos com linfangiogênese através do exame histopatológico, juntamente com os enxertos de seus transplantes anteriores e posteriores, avaliando os intervalos de tempo para sucessivas cirurgias. Métodos: Estudo descritivo, observacional, longitudinal de botões corneanos humanos com linfangiogênese, juntamente com seus transplantes anteriores e posteriores. Os tecidos foram provenientes de ceratoplastia penetrante no período compreendido entre os anos 2006 e 2013. Após revisão de prontuários em que foram obtidas principalmente as datas das cirurgias, construímos uma tábua de sobrevivência a partir da qual os intervalos de tempo para retransplante foram calculados. Resultados: Entre 89 casos de linfangiogênese corneana, foram incluídos apenas aqueles 22 que possuíam registros no prontuário de transplantes anteriores ou posteriores. Nos casos que apresentavam como provável etiologia do retransplante a linfangiogênese, isolada ou associada à hemangiogênese (grupos pré-linfangiogênese/linfangiogênese e interlinfangiogênese), foram encontrados intervalos de tempo para retransplante menores (7 e 3 meses, respectivamente) que aquele encontrado no grupo linfangiogênese/pós-linfangiogênese que apresentava outras etiologias prováveis para os retransplantes (11,31 meses). Casos que apresentavam como etiologia provável do retransplante a linfangiogênese isolada apresentaram um intervalo para retransplante (3 meses) ainda menor que aquele encontrado nos casos em que a etiologia provável era a linfangiogênese associada à hemangiogênese (7,80 meses). Conclusão: Linfangiogênese, isolada ou associada à hemangiogênese, foi encontrada nos enxertos corneanos humanos estudados que evoluíram para retransplante em pequenos intervalos de tempo. Esse achado nos leva a sugerir um possível papel para os vasos linfáticos na redução do tempo de sobrevida dos enxertos corneanos humanos.
ABSTRACT Objective: To study human corneal buttons with lymphangiogenesis through histopathological examination, together with the grafts of their preceding and subsequent transplantations, evaluating the time intervals for successive surgeries Methods: A descriptive, observational and longitudinal study of human corneal buttons that have lymphatic vessels, together with its preceding and subsequent transplants. Tissues were obtained from penetrating keratoplasty in the period between the years 2006 and 2013. After a medical records review in which information on the dates of the surgeries were mainly obtained, we built a survival table from which the time intervals for retransplantation were calculated. Results: Among 89 cases of corneal lymphangiogenesis, we included only those 22, which had previous or subsequent transplantations records in medical records. In cases where the probable regrafting etiology were lymphangiogenesis, alone or combined with hemangiogenesis (pre-lymphangiogenesis/lymphangiogenesis and interlymphangiogenesis groups), time intervals for retransplantation were found to be minor (7 and 3 months, respectively) than that found in lymphangiogenesis/post-lymphangiogenesis group that had other probable etiologies for retransplantations (11.31 months). Cases that had isolated lymphangiogenesis as probable etiology of retransplantation showed an interval time for retransplantation (3 months) lower than that found in cases in which the probable etiology was lymphangiogenesis associated with hemangiogenesis (7.80 months). Conclusion: Lymphangiogenesis, alone or combined with hemangiogenesis, was found in human corneal grafts studied that have evolved to regraft in small time intervals. This finding leads us to suggest a possible role for the lymphatic vessels in reducing the human corneal grafts survival time.
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Reoperación , Trasplante de Córnea , Queratoplastia Penetrante , Neovascularización de la Córnea/patología , Córnea/patología , Linfangiogénesis/fisiología , Córnea/irrigación sanguínea , Enfermedades de la Córnea/patología , Vasos LinfáticosRESUMEN
PURPOSE: To compare the effects of bevacizumab applied either subconjunctivally or topically, in a rat model of corneal neovascularization induced by alkali burn. METHODS: The right corneas of 24 Wistar-Albino rats were cauterized with silver nitrate sticks. The rats were divided randomly and equally into three groups: no treatment control (n=8), subconjunctival bevacizumab treatment (n=8), and topical bevacizumab treatment (n=8). Immediately following cauterization, the subconjunctival group was treated with a 0.05 ml (1.25 mg) bevacizumab subconjunctival injection. The topical group was treated with 10 mg/ml bevacizumab twice daily, and the control group received subconjunctival saline injections twice daily. The burn stimulus and neovascularization scores were evaluated using a technique previously described by Mahoney and Waterbury. Digital photographs were obtained before the eyes were enucleated and corneal sections were then analyzed by histopathology. RESULTS: The mean burn stimulus score was 1.86 ± 0.6 and there was no statistical difference between the groups (p=0.730). The mean neovascularization scores in the subconjunctival and topical bevacizumab groups were statistically lower than the control group (p<0.05). The mean percentage area of corneal neovascularization was 82.5 ± 22.1 in the control group, 42.7 ± 15.0 in the subconjunctival group, and 55.8 ± 18.2 in the topical group. The differences between the control and treatment groups were statistically significant (p<0.05). Histopathology showed that the treatment groups presented less neovascularization, inflammation, and fibroblast activity than the control group (p<0.05). CONCLUSIONS: This study demonstrates that both subconjunctival and topical administrations of bevacizumab inhibit corneal neovascularization and decrease inflammation and fibroblast activity in a rat model of corneal neovascularization induced by alkali burn.
Asunto(s)
Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales/administración & dosificación , Neovascularización de la Córnea/tratamiento farmacológico , Animales , Bevacizumab , Córnea/irrigación sanguínea , Córnea/patología , Neovascularización de la Córnea/inducido químicamente , Modelos Animales de Enfermedad , Inyecciones Intraoculares , Masculino , Distribución Aleatoria , Ratas , Ratas WistarRESUMEN
Purpose: To compare the effects of bevacizumab applied either subconjunctivally or topically, in a rat model of corneal neovascularization induced by alkali burn. Methods: The right corneas of 24 Wistar-Albino rats were cauterized with silver nitrate sticks. The rats were divided randomly and equally into three groups: no treatment control (n=8), subconjunctival bevacizumab treatment (n=8), and topical bevacizumab treatment (n=8). Immediately following cauterization, the subconjunctival group was treated with a 0.05 ml (1.25 mg) bevacizumab subconjunctival injection. The topical group was treated with 10 mg/ml bevacizumab twice daily, and the control group received subconjunctival saline injections twice daily. The burn stimulus and neovascularization scores were evaluated using a technique previously described by Mahoney and Waterbury. Digital photographs were obtained before the eyes were enucleated and corneal sections were then analyzed by histopathology. Results: The mean burn stimulus score was 1.86 ± 0.6 and there was no statistical difference between the groups (p=0.730). The mean neovascularization scores in the subconjunctival and topical bevacizumab groups were statistically lower than the control group (p<0.05). The mean percentage area of corneal neovascularization was 82.5 ± 22.1 in the control group, 42.7 ± 15.0 in the subconjunctival group, and 55.8 ± 18.2 in the topical group. The differences between the control and treatment groups were statistically significant (p<0.05). Histopathology showed that the treatment groups presented less neovascularization, inflammation, and fibroblast activity than the control group (p<0.05). Conclusions: This study demonstrates that both subconjunctival and topical administrations of bevacizumab inhibit corneal neovascularization and decrease inflammation and fibroblast activity in a rat model of corneal neovascularization induced by alkali burn. .
Objetivo: Comparar o efeito de bevacizumab aplicado subconjuntival e topicamente em um modelo de neovascularização de córnea de ratos induzida por queimadura alcalina. Métodos: Córneas direitas de 24 ratos Wistar-Albino foram cauterizados por nitrato de prata. Os indivíduos foram divididos aleatoriamente e igualmente em três grupos: controle (n=8), o bevacizumab subconjuntival (n=8), o bevacizumab tópico (n=8). Imediatamente após a cauterização, 0,05 ml (1,25 mg) de bevacizumab foi injetado no grupo subconjuntival. Grupo tópico foi inculcado com 10 mg/ml de bevacizumab duas vezes por dia. O grupo controle recebeu solução salina normal, topicamente, duas vezes ao dia. A graduação do estímulo da queimadura e a graduação da neovascularização foram avaliados utilizando a técnica descrita por Mahoney e Waterbury. Fotografias digitais foram obtidas dos olhos serem enucleados. Seções da córnea foram analisadas por histopatologia. Resultados: A média da graduação do estímulo da queimadura foi de 1,86 ± 0,6 e não houve diferença estatisticamente entre os grupos (p=0,730). As médias das graduações da neovascularização no grupo bevacizumab subconjuntival e no grupo bevacizumab tópico foram estatisticamente menores do que o grupo controle (p<0,05). A percentagem média de área de neovascularização da córnea foi de 82,5 ± 22,1 no grupo controle, 42,7 ± 15,0 no grupo subconjuntival e 55,8 ± 18,2 no grupo tópico. As diferenças entre os grupos de tratamento e grupo de controlo foram estatisticamente significativos (p<0,05). A histopatologia mostrou que os grupos de tratamento apresentavam menos neovascularização, inflamação e atividade de fibroblastos do que o grupo controle (p<0,05). ...
Asunto(s)
Animales , Masculino , Ratas , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales/administración & dosificación , Neovascularización de la Córnea/tratamiento farmacológico , Córnea/irrigación sanguínea , Córnea/patología , Neovascularización de la Córnea/inducido químicamente , Modelos Animales de Enfermedad , Inyecciones Intraoculares , Distribución Aleatoria , Ratas WistarRESUMEN
PURPOSE: To evaluate the corneal vascularization (CV) and the clinical aspects induced by interlamellar graft with native (NCM) and anionic (ACM) collagen membranes in rabbits corneas. METHODS: An interlamellar graft with a 0.25 x 0.25 cm NCM (group 1) or ACM (group 2) fragment was performed in the right eye (treated eye). In the left eye, an estromal tunnel was done (control eye). Sixteen rabbits were used, and they were subdivided into two experimental groups of eight animals each. The clinical evaluation was performed at the 1st, 3rd, 7th, 15th and 30th postoperative days. Corneal vascularization analysis was performed after 30 days by the Images Analizator System Leica Qwin-550®. RESULTS: After 7 days, corneal vascularization was observed at about 2.25 ± 0.71 mm (NCM) and at about 1.0 ± 1.69 mm (ACM), respectively, from the limbus in direction to the central cornea. After 15 days, CV increased in both groups (5.25 ± 1.03 mm - NCM; 2.0 ± 2.39 mm - ACM) and then progressively decreased until day 30 (2.25 ± 2.10 mm - NCM; 0.75 ± 2.12 mm - ACM). The statistical analysis indicated that the averages of the distances from the limb vessels to the grafts observed after 7 and 15 days had not differed statistically (p=0.17), and after 15 and 30 postoperative days had a tendency to differ statistically (p=0.09). The control eyes did not present any changes. CONCLUSION: The interlamellar graft with native and anionic collagen membranes induced corneal vascularization when applied to rabbit corneas, but anionic collagen membrane induced a smaller corneal vascularization when compared to native collagen membrane. Although further studies are required, the results found in this study demonstrated the usefulness of interlamellar graft with native and anionic collagen membranes in keratoplasties. These membranes consists in one more graft option for the surgical treatment of corneal repair in rabbits and others animals, when other forms of medical...
OBJETIVO: Avaliar os aspectos clínicos e vascularização corneal (VC) induzida pelo enxerto interlamelar das membranas de colágeno nativo (MCN) e de colágeno aniônico (MCA) em córneas de coelhos. MÉTODOS: Um fragmento com 0,25 x 0,25 cm de MCN (grupo 1) e MCA (grupo 2) foi realizado no olho direito (olho tratado) por enxertia interlamelar. No olho esquerdo (olho controle) foi realizado apenas um túnel estromal. No olho direito (olho controle) foi realizado apenas um túnel estromal. Dezesseis coelhos foram utilizados e foram divididos em dois grupos experimentais composto por oito animais cada. A avaliação clínica foi realizada aos 1, 3, 7, 15 e 30 dias de pós-operatório. A análise da vascularização corneal foi realizada após 30 dias pelo Sistema de analisador de imagens Leica Qwin-550®. RESULTADOS: Após 7 dias, a vascularização corneal do limbo em direção central da córnea observada foi de 2,25 ± 0,71 mm (MCN) e 1,0 ± 1,69 mm (ACM), respectivamente. Após 15 dias a vascularização corneal aumentou em ambos os grupos (5,25 ± 1,03 mm - MCN; 2,0 ± 2,39 mm - MCA), diminuindo até o 30º dia (2,25 ± 2,10 mm - MCN; 0,75 ± 2,12 mm - MCA). A análise estatística indicou que as médias das distâncias dos vasos do limbo em direção ao enxerto observadas após 7 e 15 dias não diferiram estatisticamente (p=0,17), e 15 e 30 dias de pós-operatório houve tendência a diferir estatisticamente (p=0,09). Os olhos controles não apresentaram nenhuma alteração. CONCLUSÃO: As membranas de colágeno nativo e de colágeno aniônico induzem a vascularização corneal quando aplicadas na córnea de coelhos por meio de enxertia interlamelar, mas membrana de colágeno ativo induz a pequena vascularização corneal quando comparada à membrana de colágeno aniônico. Embora estudos adicionais sejam necessários, os resultados encontrados no presente estudo demonstraram que as membranas de CN e CA possam ser úteis em ceratoplastias. Estas membranas consistem em mais uma opção de enxerto...
Asunto(s)
Animales , Conejos , Colágeno , Córnea/irrigación sanguínea , Trasplante de Córnea/métodos , Membranas Artificiales , Neovascularización Fisiológica , Análisis de Varianza , Materiales Biocompatibles/química , Modelos AnimalesRESUMEN
PURPOSE: To evaluate the corneal vascularization (CV) and the clinical aspects induced by interlamellar graft with native (NCM) and anionic (ACM) collagen membranes in rabbits corneas. METHODS: An interlamellar graft with a 0.25 x 0.25 cm NCM (group 1) or ACM (group 2) fragment was performed in the right eye (treated eye). In the left eye, an estromal tunnel was done (control eye). Sixteen rabbits were used, and they were subdivided into two experimental groups of eight animals each. The clinical evaluation was performed at the 1st, 3rd, 7th, 15th and 30th postoperative days. Corneal vascularization analysis was performed after 30 days by the Images Analizator System Leica Qwin-550. RESULTS: After 7 days, corneal vascularization was observed at about 2.25 +/- 0.71 mm (NCM) and at about 1.0 +/- 1.69 mm (ACM), respectively, from the limbus in direction to the central cornea. After 15 days, CV increased in both groups (5.25 +/- 1.03 mm - NCM; 2.0 +/- 2.39 mm - ACM) and then progressively decreased until day 30 (2.25 +/- 2.10 mm - NCM; 0.75 +/- 2.12 mm - ACM). The statistical analysis indicated that the averages of the distances from the limb vessels to the grafts observed after 7 and 15 days had not differed statistically (p=0.17), and after 15 and 30 postoperative days had a tendency to differ statistically (p=0.09). The control eyes did not present any changes. CONCLUSION: The interlamellar graft with native and anionic collagen membranes induced corneal vascularization when applied to rabbit corneas, but anionic collagen membrane induced a smaller corneal vascularization when compared to native collagen membrane. Although further studies are required, the results found in this study demonstrated the usefulness of interlamellar graft with native and anionic collagen membranes in keratoplasties. These membranes consists in one more graft option for the surgical treatment of corneal repair in rabbits and others animals, when other forms of medical and surgical treatment are not effective.
Asunto(s)
Colágeno , Córnea/irrigación sanguínea , Trasplante de Córnea/métodos , Membranas Artificiales , Neovascularización Fisiológica , Análisis de Varianza , Animales , Materiales Biocompatibles/química , Modelos Animales , ConejosRESUMEN
Pfaffia paniculata (Brazilian ginseng) roots have been indicated for the treatment of several diseases. Our studies have shown that P. paniculata roots present antineoplastic effects and cancer chemopreventive activity in a mouse hepatocarcinogenesis model. The purpose of this study was to investigate the effects of the Brazilian ginseng on corneal angiogenesis in mice. We first conducted a toxicological study employing 250, 500, or 1000mg/kg/day of the methanolic extract of P. paniculata roots by gavage to BALB/c mice. Animals did not lose weight during the treatment nor presented histopathological alterations. The effect of this root on angiogenesis in the cornea of BALB/c mice was then assessed. Male mice were treated, by gavage, once a day, with doses of 250, 500, or 1000mg/kg of methanolic extract of P. paniculata powdered root for 10 days; filtered water was used as control. Corneal cauterization was accomplished by the contact of a silver nitrate crystal on the central area of the cornea, in the 5th day of treatment with P. paniculata, which continued thereafter; the animals were euthanized on the 6th day after cauterization. Newly formed blood vessels were filled with India ink, and the corneas were routinely processed. Blood vessels were quantified in an image analysis system. A smaller total area of neovascularization in the mouse cornea was observed in animals treated with 1000mg/kg of the methanolic extract of P. paniculata. These results indicate an antiangiogenic effect of this extract. The mechanisms of this antiangiogenic activity of P. paniculata should be further investigated.
Asunto(s)
Amaranthaceae/química , Inhibidores de la Angiogénesis/uso terapéutico , Córnea/irrigación sanguínea , Neovascularización de la Córnea/tratamiento farmacológico , Panax , Extractos Vegetales/uso terapéutico , Administración Oral , Animales , Peso Corporal/efectos de los fármacos , Cauterización/efectos adversos , Neovascularización de la Córnea/patología , Relación Dosis-Respuesta a Droga , Masculino , Metanol/química , Ratones , Ratones Endogámicos BALB C , Raíces de Plantas/química , Pruebas de ToxicidadRESUMEN
PURPOSE: To establish a model of angiogenesis in rabbit cornea induced by punctual alkaline cauterization. METHODS: Six rabbits were submitted to punctual cauterization in right cornea. It was used a circular piece (3 mm) of filter paper, that was previously soaked in 1 M NaOH and placed 1 mm from the superior limbus for 2 minutes. The animals were evaluated at 3, 6, 9, 12, 15, 18 and 21 days after cauterization. Quantification of angiogenesis was performed according to 4 methods: radial vessel length (V), angiogenic index (I), area of the triangle (T) and area of the circular band sector (S), which provide an approximation of the area of neovascularization. RESULTS: The analysis of the quantitative data of angiogenesis showed that neovascular response progressed in a biphasic manner: rising between days 0 and 12 (proliferation), stable between days 12 and 21 (maturation). This pattern was observed on the values of the vascular growth mean rate. Between days 0 and 12, it was 16 times greater than that verified between days 12 and 21. It was found a statiscally significant positive linear correlation among the 4 methods of measurement of angiogenesis. CONCLUSION: The punctual alkaline cauterization of the rabbit cornea induces and sustains corneal neovascularization, so that, it can be used as model of angiogenesis.
Asunto(s)
Córnea/irrigación sanguínea , Córnea/patología , Inflamación/etiología , Hidróxido de Sodio/administración & dosificación , Animales , Cauterización , Femenino , Inflamación/patología , Masculino , Neovascularización Patológica , ConejosRESUMEN
BACKGROUND: The aim of this study was to evaluate the effect of tamoxifen on angiogenesis induced in rabbit cornea by breast carcinoma from post-menopausal women. METHODS: Thirteen post-menopausal women with operable, estrogen receptor-positive breast carcinomas, treated with 20 mg of tamoxifen daily for 30 days prior to undergoing definitive surgery, participated in this study. Twenty-six virgin female New Zealand white rabbits, 3-4 months old, weighing approximately 2.5 kg each, were divided into two groups of 13 animals and received corneal implants of tumor either pre- or post-tamoxifen treatment. After 10 days, the animals were sacrificed, the region of the cornea between the tumor implant and the limbus was removed and quantification of angiogenesis was carried out by evaluating the entire hematoxylin-eosin stained slide, using a 10x objective lens (100x magnification). Student t-test was used in the statistical analysis of the data and statistical significance was established at P < 0.05. RESULTS: Mean microvessel count was 106.8 +/- 5.9 pre-tamoxifen treatment and 54 +/- 5.6 post-treatment. According to Student t-test, there was a significant reduction in mean microvessel density following treatment with tamoxifen (P < 0.001). CONCLUSIONS: Rabbit cornea proved to be an interesting experimental model for the quantification of angiogenesis. Tamoxifen, when administered for 30 days to post-menopausal women with breast cancer, significantly inhibited angiogenesis induced by tumor fragments in rabbit cornea.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Córnea/efectos de los fármacos , Neoplasias del Ojo/irrigación sanguínea , Neovascularización Patológica/etiología , Tamoxifeno/farmacología , Animales , Córnea/irrigación sanguínea , Neoplasias del Ojo/patología , Femenino , Humanos , Trasplante de Neoplasias , Neovascularización Patológica/patología , Posmenopausia , Conejos , Tamoxifeno/administración & dosificaciónRESUMEN
OBJETIVO: Estabelecer um modelo de angiogênese em córnea de coelho, induzida pela cauterização pontual com hidróxido de sódio. MÉTODOS: Seis coelhos foram submetidos a uma cauterização pontual na córnea direita, utilizando-se uma peça circular (3 mm) de papel filtro, previamente embebida em NaOH 1 M, a qual foi posicionada a 1mm do limbo superior durante 2 minutos. Os animais foram avaliados nos dias 3, 6, 9, 12, 15, 18 e 21, após a cauterização. A quantificação da angiogênese foi realizada de acordo com 4 métodos: comprimento vascular radial (V), índice angiogênico (I), área do triângulo (T) e do setor de coroa circular (S), ambas medidas aproximadas da área de neovascularização. RESULTADOS: A análise das curvas dos quantificadores revelou que a resposta angiogênica seguiu um padrão bifásico: crescente até o 12º dia (proliferação), estável do 12º ao 21º dia (maturação). Comportamento também observado na taxa de crescimento vascular, que foi 16 vezes maior no período de 0 a 12 dias do que no intervalo entre o 12º e o 21º dia. Foi constatada, ainda, uma correlação linear positiva estatisticamente significante entre os 4 quantificadores de angiogênese. CONCLUSAO: A cauterização alcalina pontual da córnea de coelho induz e mantém neovascularização corneana, podendo, assim, ser utilizada como modelo de angiogênese.
Asunto(s)
Animales , Masculino , Femenino , Conejos , Córnea/irrigación sanguínea , Córnea/patología , Hidróxido de Sodio/administración & dosificación , Inflamación/etiología , Cauterización , Inflamación/patología , Neovascularización PatológicaRESUMEN
OBJETIVO: Estabelecer um modelo de angiogênese em córnea de coelho, induzida pela cauterização pontual com hidróxido de sódio. MÉTODOS: Seis coelhos foram submetidos a uma cauterização pontual na córnea direita, utilizando-se uma peça circular (3 mm) de papel filtro, previamente embebida em NaOH 1 M, a qual foi posicionada a 1mm do limbo superior durante 2 minutos. Os animais foram avaliados nos dias 3, 6, 9, 12, 15, 18 e 21, após a cauterização. A quantificação da angiogênese foi realizada de acordo com 4 métodos: comprimento vascular radial (V), índice angiogênico (I), área do triângulo (T) e do setor de coroa circular (S), ambas medidas aproximadas da área de neovascularização. RESULTADOS: A análise das curvas dos quantificadores revelou que a resposta angiogênica seguiu um padrão bifásico: crescente até o 12º dia (proliferação), estável do 12º ao 21º dia (maturação). Comportamento também observado na taxa de crescimento vascular, que foi 16 vezes maior no período de 0 a 12 dias do que no intervalo entre o 12º e o 21º dia. Foi constatada, ainda, uma correlação linear positiva estatisticamente significante entre os 4 quantificadores de angiogênese. CONCLUSAO: A cauterização alcalina pontual da córnea de coelho induz e mantém neovascularização corneana, podendo, assim, ser utilizada como modelo de angiogênese. (AU)
Asunto(s)
Animales , Masculino , Femenino , Conejos , Córnea/irrigación sanguínea , Córnea/patología , Inflamación/etiología , Hidróxido de Sodio/administración & dosificación , Cauterización , Inflamación/patología , Neovascularización de la CórneaRESUMEN
PURPOSE: To evaluate the additional benefits of amniotic membrane transplantation (AMT) when combined with conjunctival limbal autograft (CLAU) in the treatment of chronic chemical burns. METHODS: Thirty eyes of 30 rabbits underwent a chemical burn to create limbal deficiency. Forty-five days later, the animals were randomized into three groups of 10 rabbits each. Eyes from group 1 were treated with CLAU, group 2 underwent CLAU and AMT, and group 3 served as control without surgery. Corneal vascularization and opacity were documented with external photographs at postoperative days 30, 60, and 90. The rabbits were killed 3 months after surgery, and their corneas divided into two halves. One half was prepared for hematoxylin-eosin and periodic acid-Schiff staining and the other for frozen sections and immunostaining with AM3 (to MUC 5AC mucin) and AE5 (to K3 keratin). Final clinical outcome was also scored using external photographs at the last follow-up examination. RESULTS: After chemical burn, all groups showed similar degrees of conjunctivalization. After transplantation, corneal vascularization was worse in controls at 60 and 90 days (p < 0.001). At 30 days, eyes from group 1 had less corneal opacity (p < 0.05). At 90 days, corneal opacity was worse in controls but the same in groups 1 and 2 (p < 0.05). At the same time, limbal deficiency was significantly worse in controls (p < 0.05) but similar between groups 1 and 2. Corneal phenotype was present in 70% of the eyes in group 1, 50% in group 2, but in 10% of the controls. Clinical success with clear corneas was significantly more common in groups 1 and 2 when compared with controls (p < 0.001). CONCLUSIONS: CLAU is effective in treating limbal deficiency. The concurrent AMT does not add benefits in this rabbit model of chemical burns.
Asunto(s)
Amnios/trasplante , Quemaduras Químicas/cirugía , Conjuntiva/trasplante , Córnea/cirugía , Lesiones de la Cornea , Quemaduras Oculares/inducido químicamente , Quemaduras Oculares/cirugía , Animales , Vasos Sanguíneos/patología , Quemaduras Químicas/complicaciones , Quemaduras Químicas/patología , Catarata/etiología , Cáusticos , Córnea/irrigación sanguínea , Córnea/patología , Quemaduras Oculares/complicaciones , Quemaduras Oculares/patología , Masculino , Conejos , Hidróxido de Sodio , Trasplante Autólogo , Resultado del TratamientoRESUMEN
Angiogenesis is a key mechanism that influences several physiological and pathological processes, including wound healing. During the past decades, many groups have shown that controlling angiogenesis might be an answer to overcome pathological situations when this process is out of control. Many altered metabolic states exert considerable influence on the development of angiogenesis. We have chosen diabetes as a model of a progressive metabolic disease with many associated conditions, including an alteration of wound healing dynamics described elsewhere. To evaluate the growth of newly formed blood vessels during diabetes, we induced corneal angiogenesis through silver nitrate cauterization in streptozotocin-induced diabetic rats, always comparing to control non-diabetic or insulin-treated diabetic rats. Computer-aided analysis showed that both the percentage of area taken by vessels on the cornea and their average length were decreased in diabetic animals; furthermore, this diminishment was prevented by insulin treatment in previously diabetic rats. Immunohistochemical staining of neutrophils and macrophages (EDI clone) did not show any differences on number of migrating cells in the cornea. Immunolocalization of vascular endothelial growth factor and basic fibroblast growth factor did not differ considerably among groups either. These results support previous findings that angiogenesis is decreased due to the development of diabetes mellitus but contrasts to descriptions from other investigators in regard to the inflammatory infiltrate and production of growth factors. In our experimental conditions, the cause of the decreased angiogenesis in diabetic rats remains for further elucidation.
Asunto(s)
Córnea/irrigación sanguínea , Diabetes Mellitus Experimental/metabolismo , Factores de Crecimiento Endotelial/metabolismo , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Linfocinas/metabolismo , Neovascularización Patológica/metabolismo , Animales , Diabetes Mellitus Experimental/tratamiento farmacológico , Hipoglucemiantes/farmacología , Inmunohistoquímica , Inflamación/metabolismo , Insulina/farmacología , Masculino , Ratas , Ratas Sprague-Dawley , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial VascularRESUMEN
We present two contour-based techniques, for computerized object recognition that avoid the difficulties due to translations, rotations and scaling. Our techniques do not require any shape representation. The first technique uses the scale-space filtered coordinate functions of contours and their "largest diameters". The second, uses the Hotelling transform of the vector representations of the points of contours. We applied both techniques to recognize human corneal endothelial cells, embedded in a sample of tissue. The results obtained using the Hotelling transform represent a considerable improvement when compared to those previously obtained using the coordinate functions, the curvature function and Fourier descriptors as representations of shape.
Asunto(s)
Inteligencia Artificial , Aumento de la Imagen/métodos , Modelos Biológicos , Reconocimiento de Normas Patrones Automatizadas , Simulación por Computador , Córnea/irrigación sanguínea , Endotelio Vascular/citología , Análisis de Fourier , HumanosRESUMEN
A angiogênese é um processo de múltiplos degraus que conduz a formação de novos vasos sangüíneos a partir de capilares preexistentes e que participa em diversos processos fisiológicos e patológicos incluindo o crescimento tumoral e de metástases. Vários métodos têm sido desenvolvidos para estudar a angiogênese. A técnica de indução de vascularização na córnea do coelho foi uma das primeiras a serem desenvolvidas pelo grupo de Gimbrone e colaboradores. O principal objetivo deste trabalho foi descrever a técnica de indução de angiogênese na córnea do coelho, através do implante cirúrgico de "pellets" de polimetilmetacrilato (PMMA) contendo fator básico de crescimento fibroblástico (FCFb). Um "pellet" contendo 0.1 mig de FCFb foi implantado em uma das córneas e outro, sem FCFb, na córnea contralateral, como controle. A atividade angiogênica foi expressa por um índice, resultado da contagem do número de vasos e da medição de seu comprimento em milímetros. Os resultados mostraram que o FCFb induz crescimento vascular significativo a partir do sexto dia após o implante do "pellet" com atividade máxima no 15º dia. O PMMA sem FCFb não estimulou significativamente a vascularização. Esta técnica fornece uma nova opção de modelo para o estudo da biologia da angiogênese e para avaliação de drogas antiangiogênicas, usando "pellets" de polimetilmetacrilato (PMMA).
Asunto(s)
Animales , Conejos , Masculino , Femenino , Córnea/irrigación sanguínea , Neovascularización Fisiológica , Polimetil Metacrilato/farmacología , Implantes de Medicamentos , Factores de Crecimiento de Fibroblastos/farmacologíaRESUMEN
O A. relata auto-observaçäo de amaurosis fugax e hemorragia no vítreo, proveniente de sangramento de vasos episclerais na cicatriz de facectomia realizada 12 anos antes