Lysophosphatidyl choline and cataracts in uveitis.

In aqueous humor from rabbits with uveitis or after anterior chamber paracentesis, the levels of lysophosphatidyl choline (LPC) were 10.2mug/ml and 14.7mug/ml, respectively. These LPC levels induce early cataractous changes in the rabbit lens in culture. Analysis of the fatty acid composition of LPC showed that saturated fatty acids were more predominant in secondary aqueous humor than in primary aqueous humor. In vitro, natural LPC induced more pronounced gains in sodium ions and water by the lens than similar concentrations of synthetic L-alpha-lysopalmitoyl phosphatidyl choline. In contrast to prostaglandin E, the levels of LPC in aqueous humor of rabbits with uveitis are cataractogenic. Thus, LPC or its precursors, rather than prostaglandins, are involved in the production of cataracts in uveitis.

Sub-lytic C5b-9 induces functional changes in retinal pigment epithelial cells consistent with age-related macular degeneration.

PURPOSE: There is evidence for complement dysfunction in age-related macular degeneration (AMD). Complement activation leads to formation of the membrane attack complex (MAC), known to assemble on retinal pigment epithelial (RPE) cells. Therefore, the effect of sub-lytic MAC on RPE cells was examined with regard to pro-inflammatory or pro-angiogenic mediators relevant in AMD. METHODS: For sub-lytic MAC induction, RPE cells were incubated with an antiserum to complement regulatory protein CD59, followed by normal human serum (NHS) to induce 5% cell death, measured by a viability assay. MAC formation was evaluated by immunofluorescence and FACS analysis. Interleukin (IL)-6, -8, monocytic chemoattractant protein-1 (MCP-1), and vascular endothelial growth factor (VEGF) were quantified by enzyme-linked immunosorbent assay (ELISA). Intracellular MCP-1 was analysed by immunofluorescence, vitronectin by western blotting, and gelatinolytic matrix metalloproteinases (MMPs) by zymography. RESULTS: Incubation of RPE cells with the CD59 antiserum followed by 5% NHS induced sub-lytic amounts of MAC, verified by FACS and immunofluorescence. This treatment stimulated the cells to release IL-6, -8, MCP-1, and VEGF. MCP-1 staining, production of vitronectin, and gelatinolytic MMPs were also elevated in response to sub-lytic MAC. CONCLUSIONS: MAC assembly on RPE cells increases the IL-6, -8, and MCP-1 production. Therefore, sub-lytic MAC might have a significant role in generating a pro-inflammatory microenvironment, contributing to the development of AMD. Enhanced vitronectin might be a protective mechanism against MAC deposition. In addition, the increased expression of gelatinolytic MMPs and pro-angiogenic VEGF may be associated with neovascular processes and late AMD.

Eye movement abnormalities during reading in patients with Alzheimer disease.

OBJECTIVE: This goal of this study was to evaluate reading ability by assessing eye movements during reading among patients with Alzheimer disease (AD) compared with normal elderly controls. BACKGROUND: Reading is disturbed in patients with AD. These patients may have changes in reading ability early in the course of their disease before clinical alexia or abnormalities are apparent on standard reading tasks. METHOD: Reading competence was evaluated by recording eye movements during reading in 14 patients with mild to moderate clinically probable AD and 14 age- and education-matched controls. RESULTS: All patients with AD could recognize letters and words and could understand written material of similar difficulty. Despite successful reading comprehension among the patients with AD, their oculographs showed slowed reading and irregular eye movements. Compared with controls, the patients with AD did not differ in saccadic duration; however, they had significantly longer fixation times, more forward saccades per line of text, and more saccadic regressions. In addition, increased reading difficulty significantly correlated with a scale of dementia severity in the patients with AD. CONCLUSIONS: This pattern of eye movements corresponds to increased text difficulty and probably represents difficulty with lexical-semantic access in AD. These results suggest that disordered eye movements can signal difficulties in reading ability in AD even before complaints of reading difficulty or abnormalities on reading tests and may be a means of identifying linguistic impairment early in this disorder.