ABSTRACT
PURPOSE: The purpose was to measure the concentrations of various cytokines and growth factors (including vascular endothelial growth factor [VEGF] and pigment epithelium-derived factor [PEDF]) in the vitreous of patients with proliferative diabetic retinopathy (PDR) and to investigate interaction between inflammatory and proliferative factors in the genesis of PDR. Materials and Methods : Vitreous samples from 32 eyes with PDR and 25 eyes without diabetes mellitus and signs of DR (control) were collected. Vitreous concentrations of VEGF, PEDF, monocyte chemotactic protein-1 (MCP-1), interleukin-4 (IL-4), IL-6, IL-8, IL-10, IL-17A, and secretory immunoglobulin A (sIgA) were simultaneously measured using enzyme-linked immunoassay. Results : Vitreous levels of VEGF, PEDF, IL-17A, IL-6, IL-8, IL-4, and sIgA were significantly (Π < 0.05) higher in eyes with PDR compared to control. The concentration of VEGF was more than 17-times higher than in control, and the concentration of PEDF was not changed oppositely and was also higher (1.45-times) compared to control, that may indicate disturbances of compensatory mechanisms in angiogenesis regulation in PDR. Significant (Π < 0.05) positive correlations were observed between vitreous concentrations of VEGF and IL-17Î (r = 0.45), VEGF and IL-8 (r = 0.48), VEGF and IL-4 (r = 0.51), PEDF and IL-17Î (r = 0.48), PEDF and IL-8 (r = 0.59), MCP-1 and PEDF (r = 0.72), MCP-1 and IL-8 (r0 = 0.45), IL-4 and IL-17Î (r = 0.65), IL-4 and IL-8 (r = 0.71), IL-8 and IL-17Î (r = 0.59). CONCLUSIONS: Significantly raised levels of inflammatory and proliferative factors and numerous positive correlations between them may demonstrate a significant role of activation of vascular proliferation and local inflammation in the pathogenesis of PDR.
Subject(s)
Cytokines/metabolism , Diabetic Retinopathy/metabolism , Eye Proteins/metabolism , Inflammation/metabolism , Nerve Growth Factors/metabolism , Serpins/metabolism , Vascular Endothelial Growth Factor A/metabolism , Vitreous Body/metabolism , Vitreous Body/pathology , Biomarkers/metabolism , Diabetic Retinopathy/diagnosis , Diabetic Retinopathy/surgery , Female , Follow-Up Studies , Humans , Immunoenzyme Techniques , Inflammation/pathology , Male , Middle Aged , Retrospective Studies , VitrectomyABSTRACT
A passive acoustic method for detecting environmentally dangerous gas leaks from pipelines and methane naturally leaking from the seabed has been investigated. Gas escape involves the formation and release of bubbles of different sizes. Each bubble emits a sound at a specific frequency. Determination of the bubble radius from the frequency of its signature passive acoustic emission by use of so-called Minnaert formula has a restricted area of applicability near the seabed. The point is that the inertial mass and the damping constant of the birthing bubble are markedly different from those of a free bubble. The theoretical model for the bubble volume oscillations near the seabed has been proposed and an analytical solution has been derived. It was shown that the bispherical coordinates provide separation of variables and are more suitable for analysis of the volume oscillations of these constrained bubbles. Explicit formulas have been derived, which describe the dependence of the bubble emission near a rigid wall on its size and the separation distance between the bubble and the boundary.
