Prostate-specific membrane antigen is undetectable in choroidal neovascular membrane

BACKGROUND: Choroidal neovascular membrane (CNVM) is one of the leading causes of severe visual loss and is often associated with age-related macular degeneration (AMD). Various modalities of treatment, including photocoagulation and surgery, are being considered as options, but with limited success. Prostate-specific membrane antigen (PSMA) is a type II membrane glycoprotein expressed in benign and malignant prostatic tissues, in some non-prostatic tissues, and in the endothelium of tumor-associated neovasculature of non-prostatic neoplasm. Some studies have suggested that the expression of PSMA is restricted to endothelium from tumor-associated neovasculature and might be stimulated by some tumor-secreted angiogenic factors. However, no previous study demonstrating PSMA expression in non-related tumor neovasculature, such as CNVM, has been performed to date. Furthermore, demonstration of PSMA expression in CNVM in AMD patients could reveal a novel target for antineovascular therapy. The purpose of this study was to evaluate the immunohistochemical expression of PSMA in CNVM from AMD. METHODS: Immunohistochemical analysis, with a standard avidin-biotin complex technique, was performed using an anti-PSMA mouse monoclonal antibody in 30 specimens of surgically excised CNVM from AMD patients. Antibody to an endothelial cell specific marker, factor VIII, was used to confirm the location of the endothelial cells. RESULTS: The angiogenic microvessels of the 30 cases demonstrated negative staining to PSMA while factor VIII was expressed in all cases. Seventy-five percent of the secretory-acinar epithelium of the prostatic hyperplasia specimen stained positive, confirming that the immunohistochemical technique was correctly performed. CONCLUSION: The absence of PSMA expression in non-tumoral neovasculature supports the theory, previously suggested, that endothelial cell PSMA expression may be stimulated by one or more tumor-secreted angiogenic factors. Angiogenesis is very important in neoplasia and the endothelial expression of PSMA in tumor-associated neovasculature may represent a target for antineovasculature-based therapy. The absence of PSMA expression in CNVM suggests that PSMA may not be a potential target for antineovasculature-based therapy

Ocular toxoplasmosis: an update and review of the literature

Ocular toxoplasmosis is the most common cause of posterior uveitis worldwide. The infection can be acquired congenitally or postnatally and ocular lesions may present during or years after the acute infection occur. Current treatment controls ocular infection and inflammation, but does not prevent recurrences. We present a review and update on ocular toxoplasmosis and address misconceptions still found in the current medical literature.Universidade Federal de São Paulo (UNIFESP) Instituto da VisãoMcGill University Henry C Witelson Ocular Pathology LaboratoryAlbert Einstein Jewish Institute for Education and ResearchClínica SilveiraUNIFESP, Instituto da VisãoSciEL

Experimental glaucoma in the dog

O glaucoma experimental foi produzido em animais como coelho e macaco na tentativa de explicar os mecanismos da doença. Modelos de glaucoma espontâneo também foram descritos. No presente trabalho a elevação da pressão intraocular (PIO) foi produzida em 12 cães por hemácia autóloga fixada em glutaraldcído injetada na câmara anterior do olho esquerdo, sob microscópio cirúrgico. O olho direito foi o controle. Tonometria pelo SchiOtz foi realizada a cada 24 horas com o animal em posição sentada. Com intervalos de tempo que variavam de 2 a 20 dias após a injeção os animais foram sacrificados, os olhos enucleados e congelados, medidos os diâmetros sagital e transversal e então fixados em solução dc formol a 10% c os cortes corados pela hematoxilinaeosina para exame histológico. Em todos os animais a PIO foi maior quando comparado com os controles, o mesmo acontecendo com a medida dos diâmetros que foram também maiores. Os achados histológicos foram compatíveis com glaucoma.Experimental glaucoma was produced in rabbits and monkeysas an effort to explain the mechanisms of this disease. Spontaneous animal model of glaucoma has also been used. Many technics were employed to produce chronic intraocular pression (IOP) elevation. Fixed autologous red blood cells were used to produce elevated IOP in rabbits and monkeys. In this paper we present the results of the elevation of the IOP in 12 mongrel dogs injecting autologous red blood cells (RBC) fixed in 5% glutaraldehyde in phosphate buffer pH 7.0. The RBC were injected into the left eye following paracentesis and under surgical microscope. The right eyes were controls. Schiötz tonometry was performed, each 24 hours, with the dog in the sitting position. The calibration table Schiötz tonometry in dogs from PEIFFER JUNIOR et al.13 (1977) was used. The enucleated eyes were freezed and measured the sagittal and transversal diameters. The eyes were fixed in 10% formalin and sections were stained with hematoxilin-eosin for histological examination. The fixed RBC injected into the anterior chamber produced elevation in the IOP with buphthalmus and keratitis. The IOP was increased in all dogs when compared with the controls, the same occured with the eyes diameters. The pathologic findings were suggestive of glaucoma