Search results for " Single-Stranded"
showing 10 items of 81 documents
Immediate biomarker responses to benzo[a]pyrene in polluted and unpolluted populations of the blue mussel (Mytilus edulis L.) at high-latitudes.
2008
Immediate biomarker responses of two high-latitude populations of the blue mussel Mytilus edulis to benzo[a]pyrene (B[a]P) were evaluated. Mussels collected from a clean and a polluted site in southwest Iceland were exposed to the nominal dose of 100 μg B[a]P L−l for 3 h, after 4 days of acclimatization in clean seawater. To test the sensitivity to the toxicant and immediate biological responses, the following biomarkers were used: DNA single strand breaks, heart rate and feeding rate.All the biomarkers revealed differences between the study sites. Irrespective of the origin of the organisms, the short time exposure to the high B[a]P concentration did not induce DNA single strand breaks or …
Binding Mode and Selectivity of a Scorpiand-Like Polyamine Ligand to Single- and Double-Stranded DNA and RNA: Metal- and pH-Driven Modulation
2017
The interaction of a polyazacyclophane ligand having an ethylamine pendant arm functionalized with an anthryl group (L), with the single-stranded polynucleotides polyA, polyG, polyU, and polyC as well as with the double-stranded polynucleotides polyA-polyU, poly(dAT)(2), and poly(dGC)(2) has been followed by UV/Vis titration, steady state fluorescence spectroscopy, and thermal denaturation measurements. In the case of the single-stranded polynucleotides, the UV/Vis and fluorescence titrations permit to distinguish between sequences containing purine and pyrimidine bases. For the double-stranded polynucleotides the UV/Vis measurements show for all of them hypochromicity and bathochromic shif…
Analysis of p53 and mdm2 proteins in malignant fibrous histiocytoma in absence of gene alteration: prognostic significance.
2000
TP53 and MDM2 genes and their protein expression were evaluated in frozen and paraffin-embedded tissue from 27 patients with malignant fibrous histiocytoma to elucidate the relationship between them, their implication in tumor progression mechanisms and their possible diagnostic-prognostic value in malignant fibrous histiocytoma. Single-strand conformation polymorphism analysis and direct sequencing of polymerase chain reaction-amplified DNA were used to establish two TP53 mutations (7.4%): a point mutation and a 63-bp duplication. Amplification of the MDM2 gene was observed in two tumors (7.4%) by means of Southern-blot analysis, one of them also carrying the TP53 point mutation. Immunohis…
Analysis of the p53 and MDM-2 gene in acute myeloid leukemia
1996
The MDM-2 (murine double minute 2) gene codes for a cellular protein that can bind to the p53 tumor suppressor gene product, thereby functioning as a negative regulator of p53. In order to define the role of the MDM-2 gene in the pathogenesis of human acute myeloid leukemia, the expression and the sequence of the MDM-2 gene were examined in samples of bone marrow and/or peripheral mononuclear cells of 38 patients by using immunostaining, polymerase chain reaction (PCR), single strand conformation polymorphism, and sequencing. Immunohistochemical staining detected a weak accumulation of the MDM-2 protein in AML patients of FAB classification M4 and M5. RT-PCR analysis revealed a heterogeneou…
Probing the Conformational States of a pH-Sensitive DNA Origami Zipper via Label-Free Electrochemical Methods
2021
Funding Information: Financial support from EPSRC DTP (grant EP/R513349/1), the Emil Aaltonen Foundation, the Sigrid Jusélius Foundation, the Jane and Aatos Erkko Foundation, and the Vilho, Yrjö and Kalle Väisälä Foundation of the Finnish Academy of Science and Letters is gratefully acknowledged. This work was carried out under the Academy of Finland Centers of Excellence Programme (2014–2019). We acknowledge the provision of facilities and technical support by Aalto University Bioeconomy Facilities and OtaNano—Nanomicroscopy Center (Aalto-NMC) and Micronova Nanofabrication Center. Publisher Copyright: © 2021 The Authors. Published by American Chemical Society DNA origami structures represe…
Absence of mutation at the GAP-related domain of the neurofibromatosis type 1 gene in sporadic neurofibrosarcomas and other bone and soft tissue sarc…
1995
The NF1 gene encodes neurofibromin, a GTPase-activating protein containing a GAP-related domain (NF1-GRD) that is capable of downregulating ras by stimulating ras intrinsic GTPase activity. We tested 44 sarcomas, nine of which corresponded to sporadic neurofibrosarcomas, for mutations at the NF1-GRD by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique, finding no mutation in every sample tested. We suggest that inactivation of the NF1-GRD by gene mutation seems not to be an important event in the tumorigenesis of sarcomas.
Single- and Double-Strand Breaks of Dry DNA Exposed to Protons at Bragg-Peak Energies
2017
International audience; Ultrathin layers (<20 nm) of pBR322 plasmid DNA were deposited onto 2.5 μm thick polyester films and exposed to proton Bragg-peak energies (90–3000 keV) at various fluences. A quantitative analysis of radio-induced DNA damage is reported here in terms of single- and double-strand breaks (SSB and DSB, respectively). The corresponding yields as well as G-values and the cross sections exhibit fairly good agreement with the rare available data, stemming from close experimental conditions, namely, based on α particle irradiation. SSB/DSB rates appear to be linear when plotted against linear energy transfer (LET) in the whole energy range studied. All the data present a ma…
Nuclear entry and egress of parvoviruses.
2022
Parvoviruses are small non-enveloped single-stranded DNA viruses, which depend on host cell nuclear transcriptional and replication machinery. After endosomal exposure of nuclear localization sequence and a phospholipase A2 domain on the capsid surface, and escape into the cytosol, parvovirus capsids enter the nucleus. Due to the small capsid diameter of 18–26 nm, intact capsids can potentially pass into the nucleus through nuclear pore complexes (NPCs). This might be facilitated by active nuclear import, but capsids may also follow an alternative entry pathway that includes activation of mitotic factors and local transient disruption of the nuclear envelope. The nuclear entry is followed b…
Cross-reactivity of anti-ssDNA antibodies with heparan sulfate in patients with type I diabetes mellitus
1989
Anti-single-stranded–DNA antibodies cross-reactive with heparan sulfate were detected in serums of patients with type I (insulin-dependent) diabetes mellitus. The results suggested that heparan sulfate, the major glycosaminoglycan constituent of the glomerular basement membrane, may serve as a target antigen in vivo for cross-reactive anti-DNA antibodies. These polyreactive antibodies, directed toward repeating negatively charged units, may neutralize the heparan sulfate–associated polyanionic sites in the glomerulus, leading to an abnormal permeability of anionic plasma proteins.
Mouse CSB protein is important for gene expression in the presence of a single-strand break in the non-transcribed DNA strand.
2010
CSB protein is required for strand-specific repair of bulky DNA lesions in transcribed genes and mediates transcription recovery after exposure to DNA-damaging agents. We enzymatically generated DNA single-strand breaks (SSBs) with 3'-OH and 5'-phosphate termini in defined positions of a plasmid-borne gene and measured their effect on transcription in cell lines with different statuses of the Csb gene. A single SSB in the transcribed region of the gene caused significant decrease of gene expression. In all tested cell lines of mouse and human origin, a SSB in the transcribed DNA strand was less harmful for gene expression than a SSB situated in the opposing DNA strand. CSB deficiency exhibi…