Search results for " DAMAGE"

Konfokale Laser-Scanning-Mikroskopie (CLSM): Histotomographie veränderter Zahnhartgewebe bei pathologischer Mundhöhlenökologie

1997

There is no consensus regarding the aetiology of radiation-induced caries. Lesion formation is assumed to originate either from direct radiogenic damage of the hard tissue or from the indirect effects correlated with radioxerostomia. A comparative study is presented of sound teeth (group 1), teeth with documented radiation caries (group 2), teeth after in situ radiation (group 3): 60 Gy, fractionated) and teeth after in vitro radiation (group 4: 500-2500 Gy). Radiations were carried out with a 60Co source. The dentoenamel junction was studied with confocal laser scanning microscopy (CLSM). Axial sections of the teeth were used either fresh or embedded in Technovit (sawing-grinding technique…

Intragenic G-quadruplex structure formed in the human CD133 and its biological and translational relevance.

2016

Cancer stem cells (CSCs) have been identified in several solid malignancies and are now emerging as a plausible target for drug discovery. Beside the questionable existence of CSCs specific markers, the expression of CD133 was reported to be responsible for conferring CSC aggressiveness. Here, we identified two G-rich sequences localized within the introns 3 and 7 of the CD133 gene able to form G-quadruplex (G4) structures, bound and stabilized by small molecules. We further showed that treatment of patient-derived colon CSCs with G4-interacting agents triggers alternative splicing that dramatically impairs the expression of CD133. Interestingly, this is strongly associated with a loss of C…

Noninvasive cardiovascular imaging for evaluating subclinical target organ damage in hypertensive patients: a consensus article from the European Ass…

2017

International audience; : Arterial hypertension accounts for the largest amount of attributable cardiovascular mortality worldwide, and risk stratification in hypertensive patients is of crucial importance to manage treatment and prevent adverse events. Asymptomatic involvement of different organs in patients affected by hypertension represents an independent determinant of cardiovascular risk, and the identification of target organ damage is recommended to further reclassify patients' risk. Noninvasive cardiovascular imaging is progressively being used and continues to provide new technological opportunities to target organ damage evaluation at early stage. The aim of this article is to pr…

Non-invasive cardiovascular imaging for evaluating subclinical target organ damage in hypertensive patients

2017

International audience; Arterial hypertension (HTN) accounts for the largest amount of attributable cardiovascular (CV) mortality worldwide, and risk stratification in hypertensive patients is of crucial importance to manage treatment and prevent adverse events. Asymptomatic involvement of different organs in patients affected by HTN represents an independent determinant of CV risk and the identification of target organ damage (TOD) is recommended to further reclassify patients' risk. Non-invasive CV imaging is progressively being used and continues to provide new technological opportunities to TOD evaluation at early stage. The aim of this article is to provide the community of cardiology …

Cardiovascular risk assessment beyond Systemic Coronary Risk Estimation: A role for organ damage markers

2012

BACKGROUND: Cardiovascular risk assessment in the clinical practice is mostly based on risk charts, such as Framingham risk score and Systemic Coronary Risk Estimation (SCORE). These enable clinicians to estimate the impact of cardiovascular risk factors and assess individual cardiovascular risk profile. Risk charts, however, do not take into account subclinical organ damage, which exerts independent influence on risk and may amplify the estimated risk profile. Inclusion of organ damage markers in the assessment may thus contribute to improve this process. OBJECTIVE: Our aim was to evaluate the influence of implementation of SCORE charts with widely available indexes of organ damage, with t…

In situ transmission electron microscopy study of electron beam-induced transformations in colloidal cesium lead halide perovskite nanocrystals

2017

An increasing number of studies have recently reported the rapid degradation of hybrid and all-inorganic lead halide perovskite nanocrystals under electron beam irradiation in the transmission electron microscope, with the formation of nanometer size, high contrast particles. The nature of these nanoparticles and the involved transformations in the perovskite nanocrystals are still a matter of debate. Herein, we have studied the effects of high energy (80/200 keV) electron irradiation on colloidal cesium lead bromide (CsPbBr3) nanocrystals with different shapes and sizes, especially 3 nm thick nanosheets, a morphology that facilitated the analysis of the various ongoing processes. Our resul…

ERA-experiment “space biochemistry”

1995

Abstract The general goal of the experiment was to study the response of anhydrobiotic (metabolically dormant) microorganisms (spores of Bacillus subtilis, cells of Deinococcus radiodurans, conidia of Aspergillus species) and cellular constituents (plasmid DNA, proteins, purple membranes, amino acids, urea) to the extremely dehydrating conditions of open space, in some cases in combination with irradiation by solar UV-light. Methods of investigation included viability tests, analysis of DNA damages (strand breaks, DNA-protein cross-links) and analysis of chemical effects by spectroscopic, electrophoretic and chromatographic methods. The decrease in viability of the microorganisms was as exp…

Detoxication Strategy of Epoxide Hydrolase—The Basis for a Novel Threshold for Definable Genotoxic Carcinogens

2004

From our recent work on the three-dimensional structure of epoxide hydrolases we theoretically deduced the likelihood of a two-step catalytic mechanism that we and others have subsequently experimentally confirmed. Analysis of the rate of the two steps by us and by others show that the first step—responsible for removal of the reactive epoxide from the system—works extraordinarily fast (typically three orders of magnitude faster than the second step), sucking up the epoxide like a sponge. Regeneration of the free enzyme (the second step of the catalytic mechanism) is slow. This becomes a toxicological problem only at doses of the epoxide that titrate the enzyme out. Our genotoxicity work s…

Endogenous DNA Damage and Its Relevance for the Initiation of Carcinogenesis

2011

1,4-Naphthoquinones as inducers of oxidative damage and stress signaling in HaCaT human keratinocytes.

2010

Selected biological effects of 1,4-naphthoquinone, menadione (2-methyl-1,4-naphthoquinone) and structurally related quinones from natural sources--the 5-hydroxy-naphthoquinones juglone, plumbagin and the 2-hydroxy-naphthoquinones lawsone and lapachol--were studied in human keratinocytes (HaCaT). 1,4-naphthoquinone and menadione as well as juglone and plumbagin were highly cytotoxic, strongly induced reactive oxygen species (ROS) formation and depleted cellular glutathione. Moreover, they induced oxidative DNA base damage and accumulation of DNA strand breaks, as demonstrated in an alkaline DNA unwinding assay. Neither lawsone nor lapachol (up to 100 microM) were active in any of these assay…