RESUMEN
Having demonstrated transferrin (TF) and the TF receptor in periretinal membranes, we now present results of quantitative studies of TF and lactoferrin (LF), another protein with iron-binding properties. Normal human vitreous contains 74 +/- 7 mg/l TF, but less than 50 micrograms/l LF (ELISA). The TF levels determined in vitreous aspirates from patients with proliferative intraocular diseases [traumatic proliferative vitreoretinopathy (PVR), idiopathic PVR, and proliferative diabetic retinopathy (PDR)] were higher. A statistically significant difference between the levels in the vitreous in the three types of proliferative intraocular disease and in physiological vitreous was not observed. In contrary to TF, LF could not be labeled in surgically obtained membrane specimens using immunochemistry. Apparently LF does not have the same importance for cell proliferation in proliferative intraocular diseases as is suggested for TF.
Asunto(s)
Oftalmopatías/metabolismo , Lactoferrina/análisis , Transferrina/análisis , Cuerpo Vítreo/química , Ensayo de Inmunoadsorción Enzimática , HumanosRESUMEN
Transferrin (TF) is the major transport protein involved in human iron metabolism. The expression of the cell-surface TF receptor is associated with cellular proliferation, the dominant feature of proliferative vitreoretinal disorders with traction retinal detachment. A total of 14 retinal membranes from patients with different clinical diagnoses contained immunoreactive TF. Expression of the cell-surface TF receptor was confirmed by a monoclonal anti-human TF-receptor antibody label in 11 of the 14 specimens. We developed a noncompetitive enzyme-linked immunosorbent assay (ELISA) for TF and found it to be a significant component of vitreal protein, with a level of 65.7 +/- 33.9 mg/l. Vitreal TF as a major iron acceptor probably has a protective function, but its interaction with macrophages and its growth-promoting activity may subsequently stimulate the proliferation of fibroblasts and retinal pigment epithelial cells.
Asunto(s)
Receptores de Transferrina/análisis , Enfermedades de la Retina/metabolismo , Transferrina/análisis , Cuerpo Vítreo/análisis , Anticuerpos Monoclonales , Ensayo de Inmunoadsorción Enzimática , Humanos , Técnicas para Inmunoenzimas , Coloración y EtiquetadoRESUMEN
We present a retrospective study on keratopathy following vitrectomy and injection of SF96 silicone oil (viscosity 1000 centipoise, n = 232 eyes) and the purified OP 1000 silicone oil (viscosity 1000 centipoise, n = 129 eyes). In cases with aniridia, with closed inferior basal iridectomy (IBI) or without IBI, keratopathy was found in 74 of the 166 eyes (45%) injected with silicone SF96 and in 14 of the 30 eyes (47%) injected with silicone OP 1000. An intact IBI reduced the incidence of keratopathy to 0% (SF96, 0/45 eyes) or 6% (OP1000, 5/88 eyes) when the anterior chamber was free of silicone. When silicone oil was in contact with the corneal endothelium (due to periretinal reproliferation, hypotony, overfilling or droplet formation), there was corneal decompensation in 66% (SF96, 14/21 eyes) or 55% (OP1000, 6/11 eyes). The keratopathy presents as calcified band keratopathy or diffuse bullous corneal edema as in "endothelial decompensation." These variations in keratopathy are in agreement with the following basic diagnoses: 77% (43/56 eyes) of trauma patients (n = 130) develop calcified band keratopathy, and 47% (24/51 eyes) of patients with idiopathic proliferative vitreoretinopathy (n = 182) present with diffuse bullous corneal edema.
Asunto(s)
Enfermedades de la Córnea/inducido químicamente , Retinopatía Diabética/cirugía , Complicaciones Posoperatorias/patología , Neovascularización Retiniana/cirugía , Aceites de Silicona/efectos adversos , Vitrectomía/métodos , Córnea/patología , Enfermedades de la Córnea/patología , Endotelio Corneal/patología , Humanos , Iris/cirugía , Factores de Riesgo , Aceites de Silicona/administración & dosificaciónRESUMEN
Due to its high resolution and reproducibility, isoelectric focusing with a highly sensitive silver stain, in combination with electroblotting and immunodetection, may be a valuable technique to provide detailed mapping of the protein pattern of the human vitreous. By means of this technique, the presence of albumin, alpha 1-antitrypsin, alpha 1-acid glycoprotein, and transferrin in the normal human vitreous was established. Our results indicate that the differences between vitreous protein und serum protein are more of a quantitative than a qualitative nature. Preliminary studies on pathological vitreous samples obtained during vitrectomy indicate that a substantial amount of the intravitreal protein in PVR as well as in proliferative diabetic retinopathy is plasma-derived. The vitreous from eyes with a macular pucker shows a pattern of protein bands that is reminiscent of normal vitreous.