Search results for " DAMAGE"

Large diurnal variation of intraocular pressure in open angle glaucoma in subjects with type A behaviour pattern

2014

Aim : To evaluate the possible causes of the greater perimetric damage found in OAG subjects with type A behaviour and the possible role of psycho-physiological stress. Materials and methods : 80 patients with OAG, 44 women and 36 men, 40 with type A behaviour and 40 with type B studied with the Type A/B Personality Questionnaire (A modified version of the Jenkins Activity Survey), underwent a complete ophthalmologic examination consisting of bio-microscopy, tonometry and daily tonometric curve, examination of the visual field by means of Octopus 1-2-3 computerised perimeter and its assessment with the Glaucoma Staging System 2 (GSS2), morphological monitoring of the Retinal Nerve Fibre Lay…

Concentration-Dependent Protection by Ethanol Extract ofPropolis against &#947

2011

[EN] Radioprotection with natural products may be relevant to the mitigation of ionizing radiation-induced damage in mammalian systems; in this sense, propolis extracts have shown effects such as antioxidant, antitumoral, anti-inflammatory, and immunostimulant. We report for the first time a cytogenetic study to evaluate the radioprotective effect, in vitro, of propolis against radiation-induced chromosomal damage. Lymphocytes were cultured with increasing concentrations of ethanol extract of propolis (EEP), including 20, 40, 120, 250, 500, 750, 1000, and 2000 ¿g mL-1 and then exposed to 2 Gy ¿-rays. A significant and concentration-dependent decrease is observed in the frequency of chromoso…

The elemental role of iron in DNA synthesis and repair

2017

Iron is an essential redox element that functions as a cofactor in many metabolic pathways. Critical enzymes in DNA metabolism, including multiple DNA repair enzymes (helicases, nucleases, glycosylases, demethylases) and ribonucleotide reductase, use iron as an indispensable cofactor to function. Recent striking results have revealed that the catalytic subunit of DNA polymerases also contains conserved cysteine-rich motifs that bind iron–sulfur (Fe/S) clusters that are essential for the formation of stable and active complexes. In line with this, mitochondrial and cytoplasmic defects in Fe/S cluster biogenesis and insertion into the nuclear iron-requiring enzymes involved in DNA synthesis a…

The Friedreich's Ataxia protein frataxin modulates DNA base excision repair in prokaryotes and mammals

2010

DNA-repair mechanisms enable cells to maintain their genetic information by protecting it from mutations that may cause malignant growth. Recent evidence suggests that specific DNA-repair enzymes contain ISCs (iron–sulfur clusters). The nuclearencoded protein frataxin is essential for the mitochondrial biosynthesis of ISCs. Frataxin deficiency causes a neurodegenerative disorder named Friedreich's ataxia in humans. Various types of cancer occurring at young age are associated with this disease, and hence with frataxin deficiency. Mice carrying a hepatocyte-specific disruption of the frataxin gene develop multiple liver tumours for unresolved reasons. In the present study, we show that frata…

High dose infusion of activated protein C (rhAPC) fails to improve neuronal damage and cognitive deficit after global cerebral ischemia in rats

2013

Abstract Purpose : Recent studies demonstrated anticoagulatory, antiinflammatory, antiapoptotic, and neuroprotective properties of activated protein C (APC) in rodent models of acute neurodegenerative diseases, suggesting APC as promising broad acting therapeutic agent. Unfortunately, continuous infusion of recombinant human APC (rhAPC) failed to improve brain damage following cardiac arrest in rats. The present study was designed to investigate the neuroprotective effect after global cerebral ischemia (GI) with an optimized infusion protocol. Methods : Rats were subjected to bilateral clip occlusion of the common carotid arteries (BCAO) and controlled hemorrhagic hypotension to 40 mmHg for…

Strain localization and fracture in isotropic damaging materials: a novel augmented-finite element strategy

2022

Molecular mimicry may explain multi-organ damage in COVID-19

2020

International audience

Carbon ions and X‑rays induce pro‑inflammatory effects in 3D oral mucosa models with and without PBMCs.

2014

Oral mucositis is a severe complication of radiotherapy. Hence, it may constitute a serious medical safety risk for astronauts during extended space flights, such as missions to Mars, during which they are exposed to heavy-ion irradiation. For risk assessment of developing radiation-induced mucositis, a three-dimensional (3D) organotypic oral mucosa model was irradiated with 12C heavy ions or X‑rays. The present study focused mainly on early radiation‑induced effects, such as the activation of nuclear factor κB (NFκB) and the expression or release of pro-inflammatory marker molecules. The 3D oral mucosa models with or without peripheral blood mononuclear cells (PBMCs) were irradiated with X…

Oxidative DNA damage induced by visible light in mammalian cells: extent, inhibition by antioxidants and genotoxic effects

1998

The extent of the indirect DNA damage generated in mammalian cells by visible light because of the presence of endogenous photosensitizers was studied by means of repair endonucleases. In immortalized human keratinocytes (HaCaT cells) exposed to low doses of natural sunlight, the yield of oxidative DNA base modifications sensitive to the repair endonuclease formamidopyrimidine-DNA glycosylase (Fpg protein) generated by this indirect mechanism was 10% of that of pyrimidine dimers (generated by direct DNA excitation). A similar yield of Fpg-sensitive modifications, which include 8-hydroxyguanine, was observed in primary keratinocytes. The relative yield of oxidative base modifications decreas…

A Combined Experimental and Theoretical Approach to the Photogeneration of 5,6-Dihydropyrimidin-5-yl Radicals in Nonaqueous Media

2016

The chemical fate of radical intermediates is relevant to understand the biological effects of radiation and to explain formation of DNA lesions. A direct approach to selectively generate the putative reactive intermediates is based on the irradiation of photolabile precursors. But, to date, radical formation and reactivity have only been studied in aqueous media, which do not completely mimic the micro environment provided by the DNA structure and its complexes with proteins. Thus, it is also important to evaluate the photogeneration of nucleoside-based radicals in nonaqueous media. The attention here is focused on the independent generation of 5,6-dihydropyrimidin-5-yl radicals in organic…