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2016
2024
Abstract In this study, we evaluated the genomic stability of oral mucosal epithelial cells (OMECs) cultured in complex media (COM) and xenobiotic-free media (XF) to assess their potential clinical application for limbal stem cell deficiency (LSCD) treatments. OMECs serve as a promising autologous cell source for bilateral LSCD treatment, offering an alternative to limbal epithelial cells (LECs). However, genomic integrity is crucial to ensure the long-term success of transplanted cells. We performed micronucleus (MNi) tests and comet assays to compare DNA damage in OMECs cultured in both media types. The results indicated no significant differences in cell morphology, viability, or size between the two conditions. The MNi frequency was similar, with 5.67 and 6.17 MNi per 1,000 cells in COM and XF conditions, respectively. Comet assay results showed low levels of strand breaks (SBs) and oxidized DNA lesions in both media, with XF showing a slightly lower, albeit statistically insignificant, percentage of tail DNA for net Fpg-sensitive sites. Our findings suggest that OMECs can be effectively cultivated in either COM or XF media without inducing significant DNA damage, supporting the potential use of XF media in clinical settings to reduce contamination risks. This study underscores the importance of genomic stability in cultured cells for ocular surface transplantation, contributing valuable insights into optimizing culture conditions for safer and more effective clinical applications.
2025
DNA damage in circulating leukocytes measured with the comet assay may predict the risk of death
The comet assay or single cell gel electrophoresis, is the most common method used to measure strand breaks and a variety of other DNA lesions in human populations. To estimate the risk of overall mortality, mortality by cause, and cancer incidence associated to DNA damage, a cohort of 2,403 healthy individuals (25,978 person-years) screened in 16 laboratories using the comet assay between 1996 and 2016 was followed-up. Kaplan–Meier analysis indicated a worse overall survival in the medium and high tertile of DNA damage (p < 0.001). The effect of DNA damage on survival was modelled according to Cox proportional hazard regression model. The adjusted hazard ratio (HR) was 1.42 (1.06–1.90) for overall mortality, and 1.94 (1.04–3.59) for diseases of the circulatory system in subjects with the highest tertile of DNA damage. The findings of this study provide epidemiological evidence encouraging the implementation of the comet assay in preventive strategies for non-communicable diseases.
2021
2018
Environmental contaminants are found throughout Arctic marine ecosystems, and their presence in seabirds has been
associated with toxicological responses. However, there are few studies of genotoxicity in Arctic avian wildlife. The purpose of
the present study was to quantify deoxyribonucleic acid (DNA) damage in lymphocytes of selected seabird species and to
examine whether accumulation of organohalogen contaminants (SOHCs) affects DNA damage. Blood was sampled from
common eider (Somateria mollissima), black guillemot (Cepphus grylle), black-legged kittiwake (Rissa tridactyla), glaucous gull
(Larus hyperboreus), arctic skua (Stercorarius parasiticus), and great skua (Stercorarius skua) in Kongsfjorden, Svalbard (Norway).
Contaminant concentrations found in the 6 species differed, presumably because of foraging ecology and biomagnification.
Despite large differences in contaminant concentrations, ranging from SOHCs 3.3 ng/g wet weight in the common eider to
SOHCs 895 ng/g wet weight in the great skua, there was no strong difference among the species in baseline DNA damage or
sensitivity to a genotoxic stressor (hydrogen peroxide). Baseline levels of DNA damage were low, with median values ranging
from 1.7% in the common eider to 8.6% in the great skua. There were no associations between DNA damage and contaminants
in the investigated species, suggesting that contaminant concentrations in Kongsfjorden are too low to evoke genotoxic effects,
or possibly that lymphocytes are resistant to strand breakage. Clearly, genotoxicity is a topic for future studies of Arctic seabirds
Arctic; Seabirds; Genotoxicity; Comet Assay; Persistent organic pollutants; Perfluoroalkyl substances
2018
2016
2010
2012
Divergent impacts of climate interventions on China’s north-south water divide
Abstract Solar radiation modification-based climate interventions may cause uneven regional hydrological changes while mitigating warming. Here, we investigate the effects of climate interventions on China’s North Drought-South Flood pattern using the Norwegian Earth System Model supplemented by volcanic data. Our results indicate that equatorial stratospheric aerosol injection could mitigate the north-south water divide by reducing inter-hemispheric and equator-to-North-pole temperature gradients, thereby modifying atmospheric circulation and the East Asian monsoon to increase precipitation and surface runoff in northern China while reducing them in the south, compared to the high emissions scenario. This mechanism is supported by observed precipitation changes following the Mount Pinatubo volcanic eruption. In contrast, marine cloud brightening may intensify southern flood risks, while cirrus cloud thinning and moderate emissions reduction might exacerbate northern droughts. Our findings reveal distinct regional hydroclimatic impacts of different climate interventions, highlighting potential synergies and trade-offs between their global intervention efficacy and regional water security.
2025
2010
Diurnal cycle of iodine, bromine, and mercury concentrations in Svalbard surface snow
Sunlit snow is highly photochemically active and plays a key role in the exchange of gas phase species between the cryosphere and the atmosphere. Here, we investigate the behaviour of two selected species in surface snow: mercury (Hg) and iodine (I). Hg can deposit year-round and accumulate in the snowpack. However, photo-induced re-emission of gas phase Hg from the surface has been widely reported. Iodine is active in atmospheric new particle formation, especially in the marine boundary layer, and in the destruction of atmospheric ozone. It can also undergo photochemical re-emission. Although previous studies indicate possible post-depositional processes, little is known about the diurnal behaviour of these two species and their interaction in surface snow. The mechanisms are still poorly constrained, and no field experiments have been performed in different seasons to investigate the magnitude of re-emission processes Three sampling campaigns conducted at an hourly resolution for 3 d each were carried out near Ny-Ålesund (Svalbard) to study the behaviour of mercury and iodine in surface snow under different sunlight and environmental conditions (24 h darkness, 24 h sunlight and day–night cycles). Our results indicate a different behaviour of mercury and iodine in surface snow during the different campaigns. The day–night experiments demonstrate the existence of a diurnal cycle in surface snow for Hg and iodine, indicating that these species are indeed influenced by the daily solar radiation cycle. Differently, bromine did not show any diurnal cycle. The diurnal cycle also disappeared for Hg and iodine during the 24 h sunlight period and during 24 h darkness experiments supporting the idea of the occurrence (absence) of a continuous recycling or exchange at the snow–air interface. These results demonstrate that this surface snow recycling is seasonally dependent, through sunlight. They also highlight the non-negligible role that snowpack emissions have on ambient air concentrations and potentially on iodine-induced atmospheric nucleation processes.
2019
2009
Distribution of polychlorinated biphenyls (PCBs) in snow samples in northern Norway. Organohalogen compounds, 39
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