Search results for "RADIATION"
showing 10 items of 5298 documents
Fibroblasts from bank voles inhabiting Chernobyl have increased resistance against oxidative and DNA stresses
2018
Background Elevated levels of environmental ionizing radiation can be a selective pressure for wildlife by producing reactive oxygen species and DNA damage. However, the underlying molecular mechanisms that are affected are not known. Results We isolated skin fibroblasts from bank voles (Myodes glareolus) inhabiting the Chernobyl nuclear power plant accident site where background radiation levels are about 100 times greater than in uncontaminated areas. After a 10 Gy dose of gamma radiation fibroblasts from Chernobyl animals recovered faster than fibroblasts isolated from bank voles living in uncontaminated control area. The Chernobyl fibroblasts were able to sustain significantly higher do…
Infection Load and Prevalence of Novel Viruses Identified from the Bank Vole Do Not Associate with Exposure to Environmental Radioactivity
2019
Bank voles (Myodes glareolus) are host to many zoonotic viruses. As bank voles inhabiting areas contaminated by radionuclides show signs of immunosuppression, resistance to apoptosis, and elevated DNA repair activity, we predicted an association between virome composition and exposure to radionuclides. To test this hypothesis, we studied the bank vole virome in samples of plasma derived from animals inhabiting areas of Ukraine (contaminated areas surrounding the former nuclear power plant at Chernobyl, and uncontaminated areas close to Kyiv) that differed in level of environmental radiation contamination. We discovered four strains of hepacivirus and four new virus sequences: two adeno-asso…
Identification and characterization of a gene encoding a putative mouse Rho GTPase activating protein gene 8, Arhgap8.
2003
Rho GTPase activating proteins promote the intrinsic GTP hydrolysis activity of Rho family proteins. We isolated a putative mouse ortholog of the human Rho GTPase activating protein 8, ARHGAP8. The open reading frame encodes a peptide of 387 amino acids with high homology to human ARHGAP8 in its N-terminal domain. Both radiation hybrid mapping and fluorescent in situ hybridization localized the gene to mouse chromosome 15E. The 23 kb genomic Arhgap8 sequence consists of eight exons and seven introns. Northern blot and RT-PCR analyses showed that a transcript of approximately 1.9 kb is ubiquitously expressed in various adult mouse tissues with particularly strong expression in kidney.
Influence of GSM signals on human peripheral lymphocytes: study of genotoxicity.
2013
Exposure to radiofrequency (RF) electromagnetic fields (EMF) is continuously increasing worldwide. Yet, conflicting results of a possible genotoxic effect of RF EMF continue to be discussed. In the present study, a possible genotoxic effect of RF EMF (GSM, 1,800 MHz) in human lymphocytes was investigated by a collaboration of six independent institutes (institutes a, b, c, d, e, h). Peripheral blood of 20 healthy, nonsmoking volunteers of two age groups (10 volunteers 16-20 years old and 10 volunteers 50-65 years old) was taken, stimulated and intermittently exposed to three specific absorption rates (SARs) of RF EMF (0.2 W/kg, 2 W/kg, 10 W/kg) and sham for 28 h (institute a). The exposures…
Frequency of dicentrics and contamination levels in Ukrainian children and adolescents from areas near Chernobyl 20 years after the nuclear plant acc…
2013
International audience; Purpose To survey the possible presence of chromosomal damage and internal contamination in a group of Ukrainian children and adolescents, 20 years after the Chernobyl accident at the Nuclear Power Plant. Materials and methods Cytogenetical procedures were performed according to dicentric assay in 55 Ukrainian children and adolescents (29 boys and 26 girls), living near Chernobyl. In addition, a whole body detector and urinalysis were used to detect internal contamination. Results 36 dicentrics were found in a total of 53,477 metaphases scored in these children, which reflected a frequency of dicentrics below the background level. On the other hand, internal contamin…
Vascular‐derived TGF‐β increases in the stem cell niche and perturbs neurogenesis during aging and following irradiation in the adult mouse brain
2012
Neurogenesis decreases during aging and following cranial radiotherapy, causing a progressive cognitive decline that is currently untreatable. However, functional neural stem cells remained present in the subventricular zone of high dose-irradiated and aged mouse brains. We therefore investigated whether alterations in the neurogenic niches are perhaps responsible for the neurogenesis decline. This hypothesis was supported by the absence of proliferation of neural stem cells that were engrafted into the vascular niches of irradiated host brains. Moreover, we observed a marked increase in TGF-β1 production by endothelial cells in the stem cell niche in both middle-aged and irradiated mice. I…
Sex and age-specific differences in ultraviolet reflectance of scent marks of bank voles ( Clethrionomys glareolus )
2000
Scent markings of voles are visible via their ultraviolet reflection. Kestrels, and possibly other diurnal raptors, may use this property when hunting. We performed a laboratory study on bank voles to determine whether UV-reflectance of scent marks differs in relation to sex, age and social status. When reflectance spectra of scent marks were measured with a spectro-radiometer, we found UV reflectance to be strongest in mature males. There were no differences between mature females and immature juveniles, nor between sexes in juveniles or mature and immature individuals in females. Moreover, we did not find any difference in UV reflectance between dominant and subordinate mature males. The …
An approach to the evaluation of the activity of the DNA repair enzyme O6-methylguanine-DNA-methyl-transferase in tumor tissue in vivo: syntheses of …
2002
Abstract The resistance of tumor cells to the cytostatic activity of methylating and chloroethylating anticancer drugs is determined by the level of expression of the DNA repair protein O 6 -methylguanine-DNA-methyl-transferase (MGMT). The synthesis of labelled 6-benzyloxy-9H-purin-2-ylamine derivatives should hence allow a quantification of the MGMT status of tumor and non-target tissue in vivo. 6-benzyloxy-9-(2-fluoroethyl)-9H-purin-2-yl-amine and 6-benzyloxy-7-(2-fluoroethyl)-7H-purin-2-yl-amine were synthesized and evaluated in vitro, both showing an affinity of 1.8 μM. 6-benzyloxy-9-(2-[ 18 F]fluoroethyl)-9H-purin-2-yl-amine and 6-benzyloxy-7-(2-[ 18 F]fluoroethyl)-7H-purin-2-yl-amine …
Lung autophagic response following exposure of mice to whole body irradiation, with and without amifostine
2010
Research highlights: {yields} We investigated the effect 6 Gy of WBI on the autophagic machinery of normal mouse lung. {yields} Irradiation induces dysfunction of the autophagic machinery in normal lung, characterized by decreased transcription of the LC3A/Beclin-1 mRNA and accumulation of the LC3A, and p62 proteins. {yields} The membrane bound LC3A-II protein levels increased in the cytosolic fraction (not in the pellet), contrasting the patterns noted after starvation-induced autophagy. {yields} Administration of amifostine, reversed all the LC3A and p62 findings, suggesting protection of the normal autophagic function. -- Abstract: Purpose: The effect of ionizing irradiation on the autop…
The 2017 Assisi Think Tank Meeting on rectal cancer: A positioning paper
2019
BACKGROUND AND PURPOSES: To describe current practice in the management of rectal cancer, to identify uncertainties that usually arise in the multidisciplinary team (MDT)'s discussions ('grey zones') and propose next generation studies which may provide answers to them. MATERIALS AND METHODS: A questionnaire on the areas of controversy in managing T2, T3 and T4 rectal cancer was drawn up and distributed to the Rectal-Assisi Think Tank Meeting (ATTM) Expert European Board. Less than 70% agreement on a treatment option was indicated as uncertainty and selected as a 'grey zone'. Topics with large disagreement were selected by the task force group for discussion at the Rectal-ATTM. RESULTS: The…