Multidrug resistance-associated proteins in glaucoma surgery.

Background: Multidrug resistance (MDR) describes the phenomenon of cross-resistance between different cytostatic agents which are structurally and functionally dissimilar. Two recently discovered proteins, lung resistance protein (LRP) and the multidrug resistance-related protein (MRP) have been implicated in the development of MDR. Since resistance to chemotherapeutic agents is a common problem in filtration surgery, especially in cases of complicated glaucoma, we decided to investigate the presence of MRP and LRP in surgically removed Tenon specimens from glaucoma patients.

Unilateral pigmentary degeneration of the retina associated with heterochromia iridis.

Background: For the past 5 years, a 56-year-old patient has been displaying monocular progressive pigmentary changes in the left eye. Heterochromy of the left eye has been known since childhood. The other eye is clinically and functionally normal.

Retinal pigment epithelial cells: autocrine and paracrine stimulation of extracellular matrix contraction.

Background: This study was carried out to examine the biological activity of contraction promoters produced by dedifferentiating retinal pigment epithelial cells (RPE) and to evaluate the importance of autocrine and paracrine effects within a semi-closed environment like the vitreal cavity.

Methods: RPE at different stages of dedifferentiation in culture were examined for their ability (a) to generate tractional forces in vitro, with and without serum stimulation, and (b) to produce and release contraction-stimulating proteins. Autocrine versus paracrine effects of cell-secreted promoters were tested by using RPE or human dermal fibroblasts (HDF) as target cells.

Apoptosis in proliferative vitreoretinal disorders: possible involvement of TGF-beta-induced RPE cell apoptosis.

The targeted induction of apoptosis is a novel therapeutic approach to control the unlimited growth of proliferating cells. Since massive proliferation of cells at the vitreoretinal interface is a key feature of proliferative vitreoretinal disorders, we sought to identify apoptosis in epiretinal membranes from patients with proliferative vitreoretinopathy (PVR), proliferative diabetic retinopathy (PDR) and macular pucker. Further, we evaluated the possible induction of apoptosis of retinal pigment epithelial (RPE) cells by transforming growth factor-beta(TGF-beta).

Plasminogen in proliferative vitreoretinal disorders.

Objective: Intravitreal fibrin formation is a frequent observation after vitrectomy performed for a variety of vitreoretinal disorders including proliferative vitreoretinopathy (PVR), proliferative diabetic retinopathy (PDR), and endophthalmitis. Plasminogen activators (PA) have been used for the management of this postoperative complication. This approach requires the presence of plasminogen, the substrate for PA mediated fibrinolysis, in the vitreal cavity.

Spherophakia, nanophthalmia, hypoplastic ciliary body and glaucoma in brachydactyly-associated syndromes.

Three juvenile patients showing a systemic disorder associated with small stature, brachydactyly and glaucoma were discovered to have spherophakia and a nanophthalmic axial length of the eye between 20.29 and 21.26 mm.

The effect of isosorbide-mononitrate eye drops on the human intraocular pressure and aqueous humor dynamics.

In a randomized, double-masked, single drop study the effect of topical isosorbid-mononitrate (ISMO) 0.5% eye drops, the main metabolite of isosorbid-dinitrate, widely used in the treatment of coronary heart diseases, was studied in patients suffering from open angle glaucoma or ocular hypertension. There was no statistically significant IOP change within 8 hours posttreatment after topical administration of ISMO 0.

Vitronectin and proliferative intraocular disorders. I. A colocalisation study of the serum spreading factor, vitronectin, and fibronectin in traction membranes from patients with proliferative vitreoretinopathy.

The presence of a scaffold for cellular spreading and proliferation is a precondition for the development of traction membranes in proliferative vitreoretinopathy (PVR). This study shows the presence of the serum spreading factor, vitronectin, in the extracellular matrix of periretinal membranes removed during vitreoretinal surgery. By means of a double label immunofluorescence protocol, a partial colocalisation of vitronectin with fibronectin at the magnification of light microscopy can be detected.

Vitronectin and proliferative intraocular disorders. II. Expression of cell surface receptors for fibronectin and vitronectin in periretinal membranes.

Several cell types participate in the formation of vitreoretinal traction membranes in proliferative intraocular disorders. The communication between these cells involves hormones, growth factors, and the interaction with extracellular matrix molecules. We have previously demonstrated a partial colocalisation of two potent mediators of cell attachment, fibronectin and vitronectin, in periretinal membranes from patients with proliferative vitreoretinopathy (PVR).

Immunoglobulin G, complement factor C3 and lymphocytes in proliferative intraocular disorders.

This study examines a possible immunological contribution to the development of proliferative intraocular disorders (PID) with traction retinal detachment. We analysed 24 periretinal membranes and 35 vitreous aspirates from patients with idiopathic proliferative vitreoretinopathy (PVR), traumatic PVR, and proliferative diabetic retinopathy (PDR). Lymphocytes and complement factor C3 deposits could not be detected in any of the membrane specimens.

The pathogenesis of vitreoretinal proliferation and traction: a working hypothesis.

Traction retinal detachment due to proliferative vitreoretinopathy (PVR) is a serious complication of ocular trauma, retinal detachment, and previous vitreoretinal surgery. The cause is the active proliferation of fibroblasts, glial cells, and retinal pigment epithelial cells in the periretinal spaces, leading to the formation of contractile cellular membranes. The generation of growth and mitosis stimulation for these cells has remained obscure.

Hysterical symptoms in ophthalmology.

Ophthalmologic symptoms are often not sufficiently accounted for by organic pathology. The complaints of these patients have been labeled hysterical, psychogenic, non-organic, or functional. The psychiatric nosology in this area may be the most confusing in the whole field of clinical medicine.

A fluorescein angiographic study on patients with proliferative vitreoretinopathy treated by vitrectomy and intraocular daunomycin.

Fluorescein angiographic findings in patients with proliferative vitreoretinopathy treated by victrectomy, silicone oil tamponade and intraocular daunomycin are compared to findings in patients who received the same treatment but no intraocular drug. A difference between drug treated and untreated eyes was not discovered. We observed, however, a delayed arteriovenous passage time, cystoid macular edema, ectopia of the foveolar region and late hyperfluorescence of the optic disk; these findings might partly explain the visual results.

Visual hallucinations. An outline of etiological and pathogenetic concepts.

Visual hallucinations have played an important role in religion, culture, and all concepts of mental disease. A brief review of these phenomena in healthy individuals as well as in clinical medicine is provided. We analyse the pathomechanisms involved in the development of visual hallucinatory experiences and argue that no single model can serve to explain all the phenomena encountered in the field of visual hallucinations.

Immunochemical analysis of periretinal membranes. Review and outlook.

The progressive immobilization of retinal detachment through periretinal membrane formation is a major cause of blindness and difficult to treat. Initial morphological studies have revealed several features of the natural history, but immunochemistry yielded the most important results. Among the antigens detected in periretinal membranes are GFAP, keratin, vimentin, actin, fibronectin, collagen, and macrophage antigen.

Evaluation of daunomycin toxicity on lens epithelium in vitro.

Posterior capsule opacification is the major complication of extracapsular cataract extraction (ECCE). Lens epithelial cells derived from the periphery of the lens are thought to migrate posteriorly and contribute significantly to the postoperative proliferations at the posterior pole. We have evaluated the effects of the antiproliferative drug daunomycin on cultured porcine lens epithelial cell viability and proliferation.

Immunochemical studies of epiretinal membranes using APAAP complexes: evidence for macrophage involvement in traumatic proliferative vitreoretinopathy.

Proliferative vitreoretinopathy is characterized by cellular proliferations in the periretinal space resulting in traction retinal detachment. Numerous cellular elements and connective tissue components have been identified by morphologic criteria as well as immunochemical techniques. In this study, we used the recently introduced APAAP (alkaline phosphatase - anti-alkaline phosphatase) immunostaining procedure to identify macrophages, T-lymphocytes, the structural proteins fibronectin, vimentin, and cytokeratin, and a proliferating cell antigen, in eleven human epiretinal membranes obtained during vitreoretinal surgery.