Search results for "ALK"
showing 10 items of 4314 documents
Mechanisms and consequences of methylating agent-induced SCEs and chromosomal aberrations: a long road traveled and still a far way to go.
2003
Since the milestone work of Evans and Scott, demonstrating the replication dependence of alkylation-induced aberrations, and Obe and Natarajan, pointing to the critical role of DNA double-strand breaks (DSBs) as the ultimate trigger of aberrations, the field has grown extensively. A notable example is the identification of DNA methylation lesions provoking chromosome breakage (clastogenic) effects, which made it possible to model clastogenic pathways evoked by genotoxins. Experiments with repair-deficient mutants and transgenic cell lines revealed both O<sup>6</sup>-methylguanine (O<sup>6</sup>MeG) and N- methylpurines as critical lesions. For S<sub>N</sub&g…
Late activation of stress kinases (SAPK/JNK) by genotoxins requires the DNA repair proteins DNA-PKcs and CSB.
2005
Although genotoxic agents are powerful inducers of stress kinases (SAPK/JNK), the contribution of DNA damage itself to this response is unknown. Therefore, SAPK/JNK activation of cells harboring specific defects in DNA damage-recognition mechanisms was studied. Dual phosphorylation of SAPK/JNK by the genotoxin methyl methanesulfonate (MMS) occurred in two waves. The early response (≤2 h after exposure) was similar in cells knockout for ATM, PARP, p53, and CSB or defective in DNA-PKcscompared with wild-type cells. The late response however (≥4 h), was drastically reduced in DNA-PKcsand Cockayne's syndrome B (CSB)-deficient cells. Similar results were obtained with human cells lacking DNA-PKc…
Ras-Related GTPase RhoB Forces Alkylation-Induced Apoptotic Cell Death
2000
rhoB encoding a Ras-related GTPase is immediate-early inducible by genotoxic treatments. To address the question of the physiological role of RhoB in cellular defense, cells stably overexpressing wild-type RhoB protein were generated. Overexpression of RhoB renders cells hypersensitive to the killing effect of alkylating agents including antineoplastic drugs but not to UV-light and doxorubicin. As compared to control cells, RhoB overexpressing cells revealed an increase in the frequency of alkylation-induced apoptotic cell death. This indicates that RhoB is involved in modulating apoptotic signaling. Furthermore, overexpression of RhoB resulted in a prolonged transient block to DNA replicat…
The Translesion Polymerase Rev3L in the Tolerance of Alkylating Anticancer Drugs
2009
Temozolomide and fotemustine, representing methylating and chloroethylating agents, respectively, are used in the treatment of glioma and malignant melanoma. Because chemoresistance of these tumors is a common phenomenon, identification of the underlying mechanisms is needed. Here we show that Rev3L, the catalytic subunit of the translesion DNA polymerase zeta, mediates resistance to both temozolomide and fotemustine. Rev3L knockout cells are hypersensitive to both agents. It is remarkable that cells heterozygous for Rev3L showed an intermediate sensitivity. Rev3L is not involved in the tolerance of the toxic O6-methylguanine lesion. However, a possible role of Rev3L in the tolerance of O6-…
Impact of biocide treatments on the bacterial communities of the Lascaux Cave.
2009
The Lascaux Cave contains a remarkable set of paintings from the Upper Palaeolithic. Shortly after discovery in 1940, the cave was modified for public viewing and, in 2001, was invaded by a Fusarium solani species complex. Benzalkonium chloride was used from 2001 to 2004 to eliminate the fungal outbreak. In this study, we carried out a sampling in most of the cave halls and galleries. Sequence analysis and isolation methods detected that the most abundant genera of bacteria were Ralstonia and Pseudomonas. We suggest that, as a result of years of benzalkonium chloride treatments, the indigenous microbial community has been replaced by microbial populations selected by biocide application.
Bacteria and free-living amoeba in the Lascaux Cave.
2008
3 pages, 1 table, 18 references. The collaboration of the Lascaux restoration team is highly appreciated. We thank Marisa Chelius for valuable comments on the manuscript.
Acetyltransfer in natural product biosynthesis--functional cloning and molecular analysis of vinorine synthase.
2004
Vinorine synthase (EC 2.3.1.160) catalyses the acetyl-CoA- or CoA-dependent reversible formation of the alkaloids vinorine (or 11-methoxy-vinorine) and 16-epi-vellosimine (or gardneral). The forward reaction leads to vinorine, which is a direct biosynthetic precursor along the complex pathway to the monoterpenoid indole alkaloid ajmaline, an antiarrhythmic drug from the Indian medicinal plant Rauvolfia serpentina. Based on partial peptide sequences a cDNA clone was isolated and functionally expressed in Escherichia coli. The Km values of the native enzyme for gardneral and acetyl-CoA were determined to be 7.5 and 57 microM. The amino acid sequence of vinorine synthase has highest level of i…
YOLO pieeja cilvēku kustību klasificēšanai
2021
Cilvēku aktivitātes klasificēšana ar viedierīču palīdzību ir noderīga gan medicīnas pielietojumiem, gan sporta pielietojumiem, un citiem. Piemēram, pateicoties tai ir iespējams atpazīt lietotāja kritienu un savlaicīgi izsaukt palīdzību. Šajā darbā ir apskatīts kā tiek veikta cilvēku kustību atpazīšana un sportisko aktivitāšu atkārtojumu skaitīšana ar viedtālruņiem. Darba praktiskajā daļā ir ievākti kustību dati no vairākiem cilvēkiem veicot pietupienus. Šie dati izmantoti, lai izveidotu dziļo neironu tīklu modeli, kurš spēj atpazīt pietupienus, kā arī saskaitīt to atkārtojumu skaitu. Darbā tiek piedāvāts izmantot konvolūciju līmeņus un idejas no YOLO dziļo neironu tīkla, kuru izmanto objekt…
Zvaigžņotā Debess: 2011, Vasara (212)
2011
Contents: “ZVAIGŽŅOTĀ DEBESS” FORTY YEARS AGO: A.Balklavs. Extremely Distant New Objects of Metagalaxy (abridged) ; Newspaper „Literaturnaja Rossija” 9 April 1971. Astronautics: Yesterday, Today, Tomorrow (abridged) ; CONFERENCE “The VIEW from SPACE. FIRST MANNED SPACE FLIGHT – 50”: M.Gills. Conference on the Eve of Human Space Flight Anniversary ; J.Ekmanis, S.Negrejeva. Mstislav Keldysh and Golden Age of Soviet Science ; T.Millers. Contribution of Scientists of the Institute of Inorganic Chemistry to the Development of Space Technologies and Materials ; G.Vilka. Remembrance of Friedrich Zander in Rīga ; O.Plepis. My Contribution to the Development of Space Medicine ; J.Stradiņš. Latvia’s …
A GIS-based method for evaluating the walkability of a pedestrian environment and prioritised investments
2020
Abstract Despite the large investments made in the construction and modernisation of railway infrastructure, poor quality pedestrian routes may discourage users from using public transport. In fact, very little attention is generally paid to pedestrian mobility. Therefore, a method for evaluating the quality of pedestrian paths and the accessibility to railway stations has been developed. This method considers the main factors influencing the walkability of an urban area and makes it possible to establish the priorities for intervention, i.e. to identify the arcs of a pedestrian network that require prioritised action. The methodology is a decision support tool that can be used by policymak…