Search results for "reactivation"
showing 10 items of 27 documents
EGFP Reporters for Direct and Sensitive Detection of Mutagenic Bypass of DNA Lesions
2020
The sustainment of replication and transcription of damaged DNA is essential for cell survival under genotoxic stress
Cockayne syndrome: varied requirement of transcription-coupled nucleotide excision repair for the removal of three structurally different adducts fro…
2014
Hereditary defects in the transcription-coupled nucleotide excision repair (TC-NER) pathway of damaged DNA cause severe neurodegenerative disease Cockayne syndrome (CS), however the origin and chemical nature of the underlying DNA damage had remained unknown. To find out, to which degree the structural properties of DNA lesions determine the extent of transcription arrest in human CS cells, we performed quantitative host cell reactivation analyses of expression vectors containing various synthetic adducts. We found that a single 3-(deoxyguanosin-N 2-yl)-2-acetylaminofluorene adduct (dG(N 2)-AAF) constitutes an unsurmountable obstacle to transcription in both CS-A and CS-B cells and is remov…
Alterations of DNA Repair in Melanoma Cell Lines Resistant to Cisplatin, Fotemustine, or Etoposide
2000
Resistance to chemotherapy is a common phenomenon in malignant melanoma. In order to assess the role of altered DNA repair in chemoresistant melanoma, we investigated different DNA repair pathways in one parental human melanoma line (MeWo) and in sublines of MeWo selected in vitro for drug resistance against four commonly used drugs (cisplatin, fotemustine, etoposide, and vindesine). Host cell reactivation assays with the plasmid pRSVcat were used to assess processing of different DNA lesions. With ultraviolet-irradiated plasmids, no significant differences were found, indicating a normal (nucleotide excision) repair of DNA photoproducts. With singlet oxygen-treated plasmid, the fotemustine…
Reactivación participativa del espacio público. Estudios de caso en Valencia y Madrid
2017
[EN] This work aims to understand the phenomenon of what we have propose to call "participatory reactivation of public space", which is characterized by the direct participation of citizens in the creation and management of social and cultural activities in public spaces, as part of a general will to reclaim that space as truly "public", where the citizens have power in the decision-making processes. This movement has been reinforced by the establishment of professional collectives and initiatives from public institutions. Seven case studies of organizations from Valencia and Madridwere conducted, in the form of semi-structured in-depth interviews,in order to define the shared characteristi…
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…
Hepatitis Virus Reactivation in Patients with Psoriasis Treated with Secukinumab in a Real-World Setting of Hepatitis B or Hepatitis C Infection
2022
Background and Objective Biologics for psoriasis, especially anti-tumor necrosis factor-alpha therapies, may reactivate hepatitis B virus (HBV) or hepatitis C virus (HCV) infections, as well in inactive carriers or patients with occult infection. However, some biologics, including anti-interleukin-17 therapies such as secukinumab, seem to be less likely to cause hepatitis reactivation. This study assessed the safety of secukinumab treatment in patients with psoriasis with HBV or HBC infection. Methods This was a retrospective cohort study of patients with moderate-to-severe psoriasis treated with secukinumab at seven Italian centers. Patients serologically positive for one or more of the fo…
Corrigendum to “Premature ovarian senescence and a high miscarriage rate impair fertility in women with HCV” [J Hepatol 68 (2018) 33–41](S01688278173…
2018
It has come to our attention that the PITER framework investigator, Alessandro Federico, was incorrectly listed as F. Alessandro in the original manuscript. Please note that the correct name of this author is Alessandro Federico (2nd University of Naples). The correct list of PITER investigators is in the footnote below.
Trans-Reactivation: A New Epigenetic Phenomenon Underlying Transcriptional Reactivation of Silenced Genes
2015
In order to study the role played by cellular RNA pools produced by homologous genomic loci in defining the transcriptional state of a silenced gene, we tested the effect of non-functional alleles of the white gene in the presence of a functional copy of white, silenced by heterochromatin. We found that non-functional alleles of white, unable to produce a coding transcript, could reactivate in trans the expression of a wild type copy of the same gene silenced by heterochromatin. This new epigenetic phenomenon of transcriptional trans-reactivation is heritable, relies on the presence of homologous RNA’s and is affected by mutations in genes involved in post-transcriptional gene silencing. Ou…
Viral Sequence Analysis of Occult HBV Infection and Its Reactivation in Immunosuppressed Patients
2012
Mechanisms associated with reactivation of hepatitis B virus (HBV) in patients with occult HBV infection (OBI) remain unclear. In some cases immunosuppression is an enhancer of viral replication. However, not all patients with OBI who undergo immunosuppression experience reactivation. This study explores the role of viral heterogeneity as a determinant of occult HBV reactivation. HBV genotype, mutation patterns and quasispecies were assessed by sequencing the PreS/S region of 16 patients with OBI undergoing chemotherapy, 3 of whom experienced a OBI reactivation. The latter were also assessed at the time of reactivation. Phylogenetic analysis identified low nucleotide and amino acid diversit…
Isolated Nodal TBC Reactivation in a Patient with Post-Thrombocythemia Myelofibrosis Treated with Ruxolitinib: Case Report and Review of the Literatu…
2021
Ruxolitinib side effects include the most frequent hematological toxicity along with a more recently evidenced immunosuppressive activity, interfering both with the innate and adaptive immunity, and several cases of reactivation of latent infections by opportunistic agents in patients in treatment with ruxolitinib have been published in the last years. Several pathophysiological mechanisms may explain an association between ruxolitinib and opportunistic infections. From what we know, the only case of an isolated lymph node TBC reactivation in a ruxolitinib-treated myelofibrosis (MF) patient was reported by Patil et al. in 2016 [Int J Med Sci Public Health. 2017;6(3):1]. Other 10 cases descr…