Light-induced oxidation of lipids and proteins provokes retinal injuries and results in progression of degenerative retinal diseases, such as, for instance, iatrogenic photic maculopathies. Having accumulated over years retinal injuries contribute to development of age-related macular degeneration (AMD). Antioxidant treatment is regarded as a promising approach to protecting the retina from light damage and AMD. Here, we examine oxidative processes induced in rabbit retina by excessive light illumination with or without premedication using mitochondria-targeted antioxidant SkQ1 (10-(6’-plastoquinonyl)decyltriphenyl-phosphonium). The retinal extracts obtained from animals euthanized within 1–7 days post exposure were analyzed for H2O2, malondialdehyde (MDA), total antioxidant activity (AOA), and activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) using colorimetric and luminescence assays. Oxidation of visual arrestin was monitored by immunoblotting. The light exposure induced lipid peroxidation and H2O2 accumulation in the retinal cells. Unexpectedly, it prominently upregulated AOA in retinal extracts although SOD and GPx activities were compromised. These alterations were accompanied by accumulation of disulfide dimers of arrestin revealing oxidative stress in the photoreceptors. Premedication of the eyes with SkQ1 accelerated normalization of H2O2 levels and redox-status of lipids and proteins, contemporarily enhancing AOA and, likely, sustaining normal activity of GPx. Thus, SkQ1 protects the retina from light-induced oxidative stress and could be employed to suppress oxidative damage of proteins and lipids contributing to AMD.

Ocular inflammation contributes to the pathogenesis of blind-causing retinal degenerative diseases, such as age-related macular degeneration (AMD) or photic maculopathy. Here, we report on inflammatory mechanisms that are associated with retinal degeneration induced by bright visible light, which were revealed while using a rabbit model. Histologically and electrophysiologically noticeable degeneration of the retina is preceded and accompanied by oxidative stress and inflammation, as evidenced by granulocyte infiltration and edema in this tissue, as well as the upregulation of total protein, pro-inflammatory cytokines, and oxidative stress markers in aqueous humor (AH). Consistently, quantitative lipidomic studies of AH elucidated increase in the concentration of arachidonic (AA) and docosahexaenoic (DHA) acids and lyso-platelet activating factor (lyso-PAF), together with pronounced oxidative and inflammatory alterations in content of lipid mediators oxylipins. These alterations include long-term elevation of prostaglandins, which are synthesized from AA via cyclooxygenase-dependent pathways, as well as a short burst of linoleic acid derivatives that can be produced by both enzymatic and non-enzymatic free radical-dependent mechanisms. The upregulation of all oxylipins is inhibited by the premedication of the eyes while using mitochondria-targeted antioxidant SkQ1, whereas the accumulation of prostaglandins and lyso-PAF can be specifically suppressed by topical treatment with cyclooxygenase inhibitor Nepafenac. Interestingly, the most prominent antioxidant and anti-inflammatory benefits and overall retinal protective effects are achieved by simultaneous administrating of both drugs indicating their synergistic action. Taken together, these findings provide a rationale for using a combination of mitochondria-targeted antioxidant and cyclooxygenase inhibitor for the treatment of inflammatory components of retinal degenerative diseases.

Dissolution of the UO2 matrix is one of the potential routes for radionuclide release in a future deep geological repository for spent nuclear fuel. This doctoral thesis focuses on experimental studies of interfacial reactions of relevance in radiation-induced dissolution of UO2 and is divided in two parts: vi

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This article explores a fundamental shift in the humanities called the «visual turn». We are talking about the transformation of visuality in the late 19th – early 20th centuries. The difficulty of analyzing this phenomenon is due to the fact that the modern humanities have not yet developed a single subject and method for studying the visual turn. In this article, the turn as a transition from the classical to the non-classical observer is analyzed as a transformation of the very human presence in the world. The change in visuality is primarily associated with a change in the concept of the classical transcendental subject and the transition to understanding the affected and temporal subject of our time. In this article, we analyze the transformation of subjectivity based on the three-part mechanism of the power of distance, the power of gaze, and the power of memory, which was proposed by W. Benjamin. We show that at the beginning of the 20th century there takes place rethinking of a person’s presence in the world through the understanding of the destruction of the distance between the subject and the object (the world), a change in the power of gaze and a change in the role of memory in the perception of what is seen. The visible no longer acts as directly given to the subject, but presupposes the power of visual perception and the special role of memory in what is seen. This means that in modern non-classical concepts of visuality, an attempt is made to understand the act of seeing as an event of the formation of a subject. In this three-part mechanism of visual distance, the power of gazing into the visible and the role of memory in what is seen, the act of seeing becomes the very presence of modern man. However, in this case, the presence in the act of seeing eludes the subject of experience himself. Thus, visual experience in the form of a present consciousness of the world that is eternally and always does not correspond to it, is an unconscious atrophy of the most apathetic «narcissist» of vision. The article concludes that the lack of understanding of this moment of presence of the modern subject results in the fact that both the return of distance within the framework of the concept of the classical observer and the complete destruction of the aura within the concepts of the non-classical observer lead to a theoretical impasse in understanding the very experience of non-classical vision.