Search results for "DAMAGE"
showing 10 items of 1289 documents
The Impact of CdS Nanoparticles on Ploidy and DNA Damage of Rucola (Eruca sativa Mill.) Plants
2015
The genotoxic effect of cadmium sulfide nanoparticles (CdS NPs) of different sizes in rucola (Eruca sativaMill.) plants was assessed. It was confirmed that nanoparticles < 5 nm in size were more toxic than larger particles at an identical mass concentration. Significant differences in cell ploidy, as well as in the mitotic index, were detected between control and treated samples. Differences in the DNA banding pattern between control samples and samples after treatment with cadmium sulfide nanoparticles were significant and detected at different places as the appearance or elimination of DNA fragments. Fluorescence images showed that cadmium sulfide nanoparticles smaller than 5 nm in siz…
In Silico Insights into the SARS CoV-2 Main Protease Suggest NADH Endogenous Defences in the Control of the Pandemic Coronavirus Infection
2020
COVID-19 is a pandemic health emergency faced by the entire world. The clinical treatment of the severe acute respiratory syndrome (SARS) CoV-2 is currently based on the experimental administration of HIV antiviral drugs, such as lopinavir, ritonavir, and remdesivir (a nucleotide analogue used for Ebola infection). This work proposes a repurposing process using a database containing approximately 8000 known drugs in synergy structure- and ligand-based studies by means of the molecular docking and descriptor-based protocol. The proposed in silico findings identified new potential SARS CoV-2 main protease (MPRO) inhibitors that fit in the catalytic binding site of SARS CoV-2 MPRO. Several sel…
A TDDFT-based Study on the Proton-DNA Collision
2019
The interaction of heavy charged particles with DNA is of interest for several areas, from hadrontherapy to aero-space industry. In this paper, a TD-DFT study on the interaction of a 4 keV proton with an isolated DNA base pair was carried out. Ehrenfest dynamics was used to study the evolution of the system during and after the proton impact up to about 193 fs. This time was long enough to observe the dissociation of the target, which occurs between 80-100 fs. The effect of base pair linking to the DNA double helix was emulated by fixing the four O3' atoms responsible for the attachment. The base pair tends to dissociate into its main components, namely the phosphate groups, sugars and nitr…
Cu(II) complexes with a sulfonamide derived from benzoguanamine. Oxidative cleavage of DNA in the presence of H2O2 and ascorbate
2004
Reaction between benzoguanamine (2,4-diamino-6-phenyl-1,3,5-triazine) and 2-mesitylenesulfonyl chloride leads to formation of a sulfonamide able to form two mononuclear Cu(II) complexes with a CuL(2) stoichiometry. The local environment of the metal cation is a distorted octahedron, with two ligands and two solvent molecules; both complexes crystallize in the monoclinic structure, space group P2(1), with Z=2. In the presence of ascorbate/H(2)O(2,) the two complexes significantly cleavage double-strand pUC18 DNA plasmid. Both complexes exhibit more nuclease efficiency that the copper phenantroline complex. From scavenging reactive oxygen studies we conclude that the hydroxyl radical and a si…
Mechanisms of DNA damage by photoexcited 9-methyl-β-carbolines
2013
It has been well documented that β-carboline alkaloids, particularly the 9-methyl derivatives, are efficient photosensitizers. However, structure–activity relationships are missing and the photochemical mechanisms involved in the DNA photodamage still remain unknown. In the present work, we examined the capability of three 9-methyl-β-carbolines (9-methyl-norharmane, 9-methyl-harmane and 9-methylharmine) to induce DNA damage upon UVA excitation at physiological pH. The type and extent of the damage was analyzed together with the photophysical and binding properties of the β-carboline derivatives investigated. The results indicate that even at neutral pH most of the DNA damage is generated fr…
Theoretical insight into the intrinsic ultrafast formation of cyclobutane pyrimidine dimers in UV-irradiated DNA: thymine versus cytosine.
2008
The higher formation yields measured in the ultrafast photoinduced formation of cyclobutane thymine dimers (T T) with respect to those of cytosine (C C) are explained, on the basis of ab initio CASPT2 results, by the existence in thymine of more reactive orientations and a less efficient photoreversibility, whereas in cytosine the funnel toward the photolesion becomes competitive with that mediating the internal conversion of the excited-cytosine monomer.
Cisternostomy: A Timely Intervention in Moderate to Severe Traumatic Brain Injuries: Rationale, Indications, and Prospects.
2019
Traumatic brain injury (TBI) represents a major public health concern worldwide, with no significant change in its epidemiology over the last 30 years. After TBI, the primary injury induces irreversible brain damage, which is untreatable. The subsequent secondary injury plays a critical role in the clinical prognosis because without effective treatment it will provide additional tissue damage. The resulting scenario is the rise in intracranial pressure (ICP) with the development of progressive neurological deficits. Current optimal management is based on a progressive, target-driven approach combining both medical and surgical treatment strategies among which is decompressive hemicraniectom…
Activation of self-renewal and meiotic genes in tumour cell lines resistant to genotoxic treatment
2014
Pašatjaunošanās un meijotisko gēnu aktivācija pēc genotoksiskas apstrādes rezistentās audzēju šūnu līnijās Šajā darbā tika pētīta iespējamā saistība starp poliploīdijas un dzimumšūnu līnijai raksturīgo gēnu indukciju pēc pretvēža apstrādes atkarībā no TP53 statusa un audzēju šūnu rezistence pret DNS bojājumu. Pirmo reizi tika atrasta un citoloģiski raksturota galveno cilmestības transkripcijas faktoru OCT4, NANOG un SOX2 ekspresijas aktivācija, kas izraisīta pārkāpjot tetraploīdo barjeru pēc DNS bojājuma TP53 mutantās, bet ne funkcionālās audzēja šūnas, kā arī galvenā mejotiskā kohezīna REC8 ekspresija somatisko audzēja šūnu līnijās, kas apstrādātas ar jonizējošo starojumu vai topoizomeraze…
Photoinduced DNA Lesions in Dormant Bacteria: The Peculiar Route Leading to Spore Photoproducts Characterized by Multiscale Molecular Dynamics
2020
International audience; Some bacterial species enter a dormant state in the form of spores to resist to unfavorable external conditions. Spores are resistant to a wide series of stress agents, including UV radiation, and can last for tens to hundreds of years. Due to the suspension of biological functions, such as DNA repair, they accumulate DNA damage upon exposure to UV radiation. Differently from active organisms, the most common DNA photoproducts in spores are not cyclobutane pyrimidine dimers, but rather the so‐called spore photoproducts. This noncanonical photochemistry results from the dry state of DNA and its binding to small, acid‐soluble proteins that drastically modify the struct…
Morālā kaitējuma kompensācija kriminālprocesā
2022
Saskaņā ar Kriminālprocesa likuma 22. pantu, cietušajam tiek garantētas tiesības, noziedzīga nodarījuma gadījumos, iespēja morālās kompensācijas pieprasīšanai un saņemšanai. Globalizācijas apstākļos, ir pieaugoša tendence uz visaptverošu unifikāciju, kas ietekmē visas valstis kopā un katru valsti atsevišķi. Bakalaura darba mērķis ir izpētīt un analizēt morālās kaitējuma jēdzienu, morālā kaitējuma kompensācijas apmēra noteikšanu krimināltiesībās un tiesisko regulējumu Latvijā. Lai darba mērķi sasniegtu, veikts salīdzinājumu par morālās kompensācijas apmēra noteikšanas mehānismiem Latvijā un citās Eiropas valstīs. Veikts Latvijas un ārvalstu normatīvo regulējumu analīze, tiesu prakses un judi…