Demographic, exposure and clinical characteristics in a multinational registry of engineered stone workers with silicosis.

OBJECTIVES: To investigate differences in workplace exposure, demographic and clinical findings in engineered stone (ES) workers from a multinational consortium using the Engineered Stone Silicosis Investigators (ESSI) Global Silicosis Registry. METHODS: With ethics board approval in Israel, Spain, Australia and the USA, ES workers ages 18+ with a physician diagnosis of work-related silicosis were enrolled. Demographic, occupational, radiologic, pulmonary function and silica-related comorbidity data were compared cross-sectionally among countries using analysis of variance, Fisher's exact tests and logistic regression. RESULTS: Among 169 ES workers with silicosis, most were men, with mean age 51.7 (±11.4) years. Mean work tenure in stone fabrication or masonry was 19.9 (±9.8) years. Different methods of case ascertainment explained some inter-country differences, for example, workers in Queensland, Australia with a state-based surveillance program were likely to be identified earlier and with shorter work tenure. Overall, 32.5% of workers had progressive massive fibrosis, the most severe form of dust-related pneumoconiosis, of whom 18.5% reported ≤10 years of work tenure. Lung function impairment including restriction, reduced diffusion capacity and hypoxaemia was common, as was autoimmunity. CONCLUSIONS: Findings from a multinational registry represent a unique effort to compare demographic, exposure and clinical information from ES workers with silicosis, and suggest a substantial emerging population of workers worldwide with severe and irreversible silica-associated diseases. This younger worker population is at high risk for disease progression, multiple comorbidities and severe disability. The ESSI registry provides an ongoing framework for investigating epidemiological trends and developing prospective studies for prevention and treatment of these workers.

Inflammation, angiogenesis and coagulation interplay in a variety of retinal diseases.

PURPOSE: To evaluate and correlate levels of various proteins involved in coagulation, inflammation and angiogenesis processes in the vitreous of patients with different vitreoretinal pathologies. METHODS: Vitreous samples were collected from patients scheduled for pars plana vitrectomy for the treatment of rhegmatogenous retinal detachment (RRD), vitreous haemorrhage or tractional retinal detachment associated with proliferative diabetic retinopathy (PDR). Macular hole and epiretinal membrane served as controls. Levels of vascular endothelial growth factor, thrombin-antithrombin III complex, interleukin-8, tissue factor, thrombomodulin, P-selectin, D-dimer and tissue factor pathway inhibitor were compared among the vitreoretinal pathology groups. RESULTS: Compared to controls, patients with PDR had significantly higher levels of thrombin-antithrombin III complex (p < 0.001), vascular endothelial growth factor (p < 0.001), D-dimer (p = 0.038) and interleukin-8 (p = 0.04), and patients with RRD group had significantly higher levels only of thrombin-antithrombin III complex (p < 0.001). There was a significant linear correlation between levels of P-selectin and D-dimer (p = 0.003), P-selectin and interleukin-8 (p < 0.001), and D-dimer and IL-8 (p = 0.007). These correlations were particularly strong in the PDR group compared to the other groups. CONCLUSION: Patients with PDR manifest high coagulative and angiogenic activity in the vitreous. These pathways are highly correlated with the inflammatory cascade.

Activated protein C induces suppression and regression of choroidal neovascularization- A murine model.

Activated protein C (APC) exerts diverse cell signaling pathways which results in multiple distinct cytoprotective actions. These include anti-apoptotic and anti-inflammatory activities and stabilization of endothelial and epithelial barriers. We studied the ability of APC to inhibit the leakage and the growth of newly formed as well as pre-existing choroidal neovascularization (CNV) and examined the ability of APC to stabilize the Retinal Pigmented Epithelium (RPE). We explored the contribution of Tie2 receptor to the protective effects of APC. CNV was induced by laser photocoagulation in C57BL/6J mice. APC was injected intravitreally immediately or 7 days after CNV induction. Neovascularization was evaluated on RPE-choroidal flatmounts using FITC-dextran perfusion and CD31 immunofluorescence. CNV leakage was measured by fluorescein angiography (FA). The ability of APC to stabilize the RPE barrier was evaluated in-vitro by dextran permeability and zonula occludens 1 (ZO1) immunostaining. Tie2 blocking was induced in-vivo by intraperitoneal injection of Tie2 kinase inhibitor and in-vitro by incubation with anti Tie2 antibodies. APC treatment dramatically inhibited the generation of newly formed CNV leakage sites and reversed leakage in 85% of the pre-existing CNV leaking sites. In RPE cell culture, APC induced translocation of ZO1 to the cell membrane, accompanied by reduction in permeability of the monolayer. Inhibition of Tie2 significantly decreased APC protective activities in both the mouse model and the RPE cell culture. Our results show that APC treatment significantly inhibits the leakage and growth of newly formed, as well as pre-existing CNV, and its protective activities are partially mediated via the Tie2 receptor. The data suggest that APC should be further investigated as a possible effective treatment for CNV.

The Histone Deacetylase Inhibitor AN7, Attenuates Choroidal Neovascularization in a Mouse Model.

: Choroidal neovascularization (CNV) is a complication of age-related macular degeneration and a major contributing factor to vision loss. In this paper, we show that in a mouse model of laser-induced CNV, systemic administration of Butyroyloxymethyl-diethyl phosphate (AN7), a histone deacetylase inhibitor (HDACi), significantly reduced CNV area and vascular leakage, as measured by choroidal flatmounts and fluorescein angiography. CNV area reduction by systemic AN7 treatment was similar to that achieved by intravitreal bevacizumab treatment. The expression of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF-2), and the endothelial cells marker CD31, was lower in the AN7 treated group in comparison to the control group at the laser lesion site. In vitro, AN7 facilitated retinal pigmented epithelium (RPE) cells tight junctions' integrity during hypoxia, by protecting the hexagonal pattern of ZO-1 protein in the cell borders, hence reducing RPE permeability. In conclusion, systemic AN7 should be further investigated as a possible effective treatment for CNV.

Mobile Laser Indirect Ophthalmoscope: For the Induction of Choroidal Neovascularization in a Mouse Model.

PURPOSE: This study aims to evaluate and standardize the reliability of a mobile laser indirect ophthalmoscope in the induction of choroidal neovascularization (CNV) in a mouse model. MATERIALS & METHODS: A diode laser indirect ophthalmoscope was used to induce CNV in pigmented male C57BL/6J mice. Standardization of spot size and laser intensity was determined using different aspheric lenses with increasing laser intensities applied around the optic disc. Development of CNV was evaluated 1, 5, and 14 days post laser application using fluorescein angiography (FA), histology, and choroidal flat mounts stained for the endothelial marker CD31 and FITC-dextran. Correlation between the number of laser hits to the number and size of developed CNV lesions was determined using flat mount choroid staining. The ability of intravitreally injected anti-human and anti-mouse VEGF antibodies to inhibit CNV induced by the mobile laser was evaluated. RESULTS: Laser parameters were standardized on 350 mW for 100 msec, using the 90 diopter lens to accomplish the highest incidence of Bruch's membrane rupture. CNV lesions' formation was validated on days 5 and 14 post laser injury, though FA showed leakage on as early as day 1. The number of laser hits was significantly correlated with the CNV area. CNV growth was successfully inhibited by both anti-human and mouse VEGF antibodies. CONCLUSION: The mobile laser indirect ophthalmoscope can serve as a feasible and a reliable alternative method for the CNV induction in a mouse model.

Correlation between Interleukin-6 and Thrombin-Antithrombin III Complex Levels in Retinal Diseases.

PURPOSE: This study aims to evaluate and correlate the levels of interleukin-6 (IL-6) and thrombin-antithrombin III complex (TAT) in the vitreous of patients with different vitreoretinal pathologies. METHODS: Vitreous samples were collected from 78 patients scheduled for pars plana vitrectomy at a tertiary medical center. Patients were divided by the underlying vitreoretinal pathophysiology, as follows: macular hole (MH)/epiretinal membrane (ERM) (n = 26); rhegmatogenous retinal detachment (RRD) (n = 32); and proliferative diabetic retinopathy (PDR) (n = 20). Levels of IL-6 and TAT were measured by enzyme-linked immunosorbent assay and compared among the groups. RESULTS: A significant difference was found in the vitreal IL-6 and TAT levels between the MH/ERM group and both the PDR and RRD groups (P < 0.001 for all). Diabetes was associated with higher IL-6 levels in the RRD group. Different relationships between the IL-6 and TAT levels were revealed in patients with different ocular pathologies. CONCLUSION: Our results imply that variations in vitreal TAT level may be attributable not only to an inflammatory reaction or blood-retinal barrier breakdown, but also to intraocular tissue-dependent regulation of thrombin.

Effect of Histone Deacetylase Inhibitor, Butyroyloxymethyl-Diethyl Phosphate (AN-7), on Corneal Neovascularization in a Mouse Model.

PURPOSE: To examine whether butyroyloxymethyl-diethyl phosphate (AN-7), a histone deacetylase inhibitor, inhibits chemically induced corneal neovascularization (NV) in mice. METHODS: Corneal NV was induced in the right eye of male C57BL mice by application of a mixture of 75% silver nitrate and 25% potassium nitrate to the corneal center. Immediately thereafter, the mice were randomized into 2 groups, receiving an intraperitoneal injection of AN-7 or saline, which served as control. Corneal NV was evaluated at constant time intervals from the corneal injury by corneal photographs and the area of corneal NV was measured. Centricity and density of the corneal vascularization were graded. Corneal flat mounts blood vessels staining and histological studies were performed on day 10. Unpaired t-test was used for group comparisons. RESULTS: The corneal neovascular area was statistically significantly reduced by AN-7 treatment on days 10 and 14 postinjury and compared with the untreated group. The centricity and density of the corneal NV between treated and untreated groups showed no significant difference at any time point. CONCLUSIONS: Systemic treatment with AN-7 had a significant inhibitory effect on chemical burn-induced corneal NV in mice. These results suggest that AN-7 should be further evaluated for its therapeutic potential for the treatment of corneal NV.