Search results for "otos"
showing 10 items of 857 documents
8-Oxoguanine DNA glycosylase (Ogg1) causes a transcriptional inactivation of damaged DNA in the absence of functional Cockayne syndrome B (Csb) prote…
2008
We have analysed the effect of oxidative guanine lesions on the expression of a transfected reporter gene in mouse embryonic fibroblasts deficient in Cockayne syndrome B protein (Csb) and/or the 8-oxoguanine DNA glycosylase (Ogg1). We used a highly sensitive flow cytometry-based approach and quantitative real-time PCR to measure the changes in gene expression caused by the presence of oxidised guanine residues generated by photosensitisation in the vector DNA. In wild-type cells, small numbers (one or three) of oxidised guanines did not affect gene expression at short times after transfections, whereas progressive reduction of the transgene expression was observed at later time points. Alth…
Intra- and extra-cellular DNA damage by harmine and 9-methyl-harmine
2014
It is known that b-carbolines are able to produce photosensitized damage in cell-free DNA, but there is little information on their effects on cellular DNA. Therefore, we have analyzed the DNA damage produced by harmine and 9-methyl-harmine under UVA irradiation in V79 cells, together with the associated generation of micronuclei and photocytotoxicity. The results indicate that the most frequent photoproducts generated in the cellular DNA are modified purines such as 8-oxo-7,8-dihydroguanine. Only relatively few single-strand breaks were observed. CPDs were absent, although they were generated in cell-free DNA irradiated under the same conditions. The overall extent of DNA damage in the cel…
Modelling Photoionisations in Tautomeric DNA Nucleobase Derivatives 7H-Adenine and 7H-Guanine: Ultrafast Decay and Photostability
2021
The study of radiation effects in DNA is a multidisciplinary endeavour, connecting the physical, chemical and biological sciences. Despite being mostly filtered by the ozone layer, sunlight radiation is still expected to (photo)ionise DNA in sizeable yields, triggering an electron removal process and the formation of potentially reactive cationic species. In this manuscript, photoionisation decay channels of important DNA tautomeric derivatives, 7H-adenine and 7H-guanine, are characterised with accurate CASSCF/XMS-CASPT2 theoretical methods. These simulation techniques place the onset of ionisation for 7H-adenine and 7H-guanine on average at 8.98 and 8.43 eV, in line with recorded experimen…
The Gaia-ESO Survey: Dynamics of ionized and neutral gas in the Lagoon nebula (M 8)
2017
Aims. We present a spectroscopic study of the dynamics of the ionized and neutral gas throughout the Lagoon nebula (M 8), using VLT-FLAMES data from the Gaia-ESO Survey. The new data permit exploration of the physical connections between the nebular gas and the stellar population of the associated star cluster NGC 6530. Methods. We characterized through spectral fitting emission lines of Hα, [N II] and [S II] doublets, [O III], and absorption lines of sodium D doublet, using data from the FLAMES-Giraffe and UVES spectrographs, on more than 1000 sightlines toward the entire face of the Lagoon nebula. Gas temperatures are derived from line-width comparisons, densities from the [S II] doublet …
To die or not to die ? un modèle de la signalisation dichotomique de TNF-R1
2004
1. Kurotaki N, Imaizumi K, Harada N, et al. Haplo insufficiency of NSD1 causes Sotos syndrome. Nature 2002 ; 30 : 305-6. 2. Douglas J, Hanks S, Temple K, et al. NSD1 mutations are the major cause of Sotos syndrome and occur in some cases of Weaver syndrome but are rare in other overgroth phenotypes. Am J Hum Genet 2003 ; 27 : 132-43. 3. Rio M, Clech L, Amiel J, et al. Spectrum of NSD1 mutations in Sotos and Weaver syndromes. J Med Genet 2003 ; 40 : 436-40. 4. Imaizumi K, Kimura J, Matsuo M, et al. Sotos syndrome associated with a de novo balanced reciprocal translocation t(5 ;8)(q35 ;q24.1). Am J Hum Genet 2002 ; 107 : 58-60. 5. Opitz JM, Weaver DW, Reynolds JF. The syndrome of Sotos and We…
Chemotherapy-induced cardiotoxicity: role of the conventional echocardiography and the tissue Doppler.
2011
Aim. The cardiotoxicity of anticancer drugs is an emerging problem and only an identification of the early signs of cardiotoxicity by conventional echocardiography and not (tissue Doppler imaging, TDI), will limit and contain the long-term cardiotoxicity effects. The aim of this study was to identify, through conventional echocardiography and TDI, parameters to use as early "signs" of cardiotoxicity. Methods. A prospective study was performed using patients with breast cancer (72 women, median age 57+/-12) treated with anticancer drugs (adjuvant chemotherapy). All patients underwent a careful cardiological evaluation before starting treatment (T0) and during follow-up at 3 months (T1), 6 mo…
Study of the Mode and Efficiency of DNA Binding in the Damage Induced by Photoactivated Water Soluble Porphyrins
2013
We have investigated the DNA binding interactions and in vitro photoactivated DNA damage induced by a neutral water soluble porphyrin derivative 5,10,15,20-tetrakis(2,4,6-trihydroxyphenyl)porphyrin (TTHPP) and its zinc derivative 5,10,15,20-tetrakis(2,4,6-trihydroxyphenyl)porphyrinato zinc(II) (Zn-TTHPP) upon visible light irradiation through various spectroscopic techniques and employing repair endonucleases. These porphyrin derivatives exhibited high affinity toward DNA through groove binding interactions as evidenced through the UV-vis absorption, emission, circular dichroism spectral and viscosity changes. Interestingly, the free base porphyrin derivative, TTHPP generated efficient sing…
The Chameleon on the branches: spectral state transition and dips in NGC 247 ULX-1
2021
Soft Ultra-Luminous X-ray (ULXs) sources are a subclass of the ULXs that can switch from a supersoft spectral state, where most of the luminosity is emitted below 1 keV, to a soft spectral state with significant emission above 1 keV. In a few systems, dips have been observed. The mechanism behind this state transition and the dips nature are still debated. To investigate these issues, we obtained a long XMM-Newton monitoring campaign of a member of this class, NGC 247 ULX-1. We computed the hardness-intensity diagram for the whole dataset and identified two different branches: the normal branch and the dipping branch, which we study with four and three hardness-intensity resolved spectra, r…
Optimising an outdoor membrane photobioreactor for tertiary sewage treatment
2019
[EN] The operation of an outdoor membrane photobioreactor plant which treated the effluent of an anaerobic membrane bioreactor was optimised. Biomass retention times of 4.5, 6, and 9 days were tested. At a biomass retention time of 4.5 days, maximum nitrogen recovery rate:light irradiance ratios, photosynthetic efficiencies and carbon biofixations of 51.7¿±¿14.3¿mg¿N·mol¿1, 4.4¿±¿1.6% and 0.50¿±¿0.05¿kg CO2·m3influent, respectively, were attained. Minimum membrane fouling rates were achieved when operating at the shortest biomass retention time because of the lower solid concentration and the negligible amount of cyanobacteria and protozoa. Hydraulic retention times of 3.5, 2, and 1.5 days …
Comparative Investigation on the Nutrient Composition of Healthy and Injured Spruces of Different Locations
1988
Investigations on the content of cations (Ca2+, K+, Mg2+ and Mn2+) were carried out in spruce trees at two exemplary locations in the Taunus montains (Konigstein) and in the Hunsruck mountains (Hattgenstein) in the course of the vegetation period in 1985 and 1986.