| 1. |
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| 2. |
- Aad, G., et al.
(author)
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The ATLAS Experiment at the CERN Large Hadron Collider
- 2008
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In: Journal of Instrumentation. - 1748-0221. ; 3:S08003
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Research review (peer-reviewed)abstract
- The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.
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| 3. |
- Andersson, Helén, 1982-, et al.
(author)
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Low levels of the air pollutant 1-nitropyrene induce DNA damage, increased levels of reactive oxygen species and endoplasmic reticulum stress in human endothelial cells
- 2009
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In: Toxicology. - : Elsevier BV. - 0300-483X .- 1879-3185. ; 262:1, s. 57-64
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Journal article (peer-reviewed)abstract
- Both epidemiological and experimental studies suggest that exposure to high levels of air pollution is a risk factor associated with cardiovascular disease. Traffic emission is a major source of exposure to persistent air pollutants such as nitrated polycyclic aromatic hydrocarbons (nitro-PAHs). 1-Nitropyrene (1-NP), one of the most abundant nitro-PAHs in diesel exhausts, was selected as a model nitro-PAH for the present study. The aim of the study was to investigate the effects of 1-NP in human umbilical vein endothelial cells (HUVECs) and the metabolic pathways involved. The nitroreductase inhibitor dicoumarol and the coplanar aryl hydrocarbon receptor (AhR) ligand PCB 126 were used to modulate the metabolism of 1-NP. The results revealed that low levels (< or =10microM) of 1-NP induced DNA damage, increased levels of reactive oxygen species (ROS) and increased protein expression of the endoplasmic reticulum (ER) stress chaperone GRP78. A decrease in cell viability was only observed following exposure to a higher level of 1-NP (15microM). Inhibition of nitroreductive metabolism by dicoumarol attenuated the induction of DNA damage, intracellular ROS levels and GRP78 expression. This suggests that the effects of 1-NP on HUVEC were mediated by metabolites mainly formed at nitroreduction. Our findings suggest that the human blood vessel endothelium is a sensitive target tissue for the major nitro-PAH constituent in diesel exhaust.
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| 4. |
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| 5. |
- Andersson, Maria A., et al.
(author)
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Evaluation of the potential genotoxicity of chromium picolinate in mammalian cells in vivo and in vitro
- 2007
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In: Food and Chemical Toxicology. - : Elsevier BV. - 0278-6915 .- 1873-6351. ; 45:7, s. 1097-1106
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Journal article (peer-reviewed)abstract
- Chromium picolinate (CrPic) is a synthetic nutritional supplement primarily used for weight loss and muscle building. Recent studies have indicated that CrPic might be genotoxic and these findings together with the wide-spread consumer use, have increased the concern about its safety. In the present study we investigated the potential genotoxicity of CrPic in mice given a single intraperitoneal injection (up to 3 mg/kg b.wt.) by evaluating the frequency of micronucleated polychromatic erythrocytes (fMNPCE) in peripheral blood, and DNA damage in lymphocytes and hepatocytes. The fMNPCE was evaluated after 42 h and DNA damage after 16 h. Using the Comet assay DNA damage was also monitored in extended-term cultures of human lymphocytes and in L5178Y mouse lymphoma cells that had been exposed for 3 h to 500 μM CrPic under different exposure conditions.A slight, but significant CrPic-induced increase in DNA damage (P < 0.001) was observed in the human lymphocytes, but only when these cells were exposed in the absence of serum. In all other experiments CrPic was found to be without genotoxic effects, both in vivo and in vitro. Taken together, our results suggest that a high concentration of CrPic might be DNA damaging, but only under non-physiological conditions.
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| 6. |
- Andersson, Maria, 1976-
(author)
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Chemically Induced DNA Damage in Extended-term Cultures of Human Lymphocytes
- 2006
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Doctoral thesis (other academic/artistic)abstract
- Generation of DNA damage is regarded to be an important initial event in the development cancer. Consequently, a battery of tests have been developed to detect different types of genotoxic effects in order to be able to predict the potential genotoxicity and mutagenicity of chemicals, including both pharmaceutical drugs and various types of environmental and occupational agents, as well as dietary factors. The aim of this thesis was to evaluate whether the combination of the comet assay and the extended-term cultures of human lymphocytes (ETC) can be used as an alternative in vitro system to more commonly used transformed mammalian cell lines, and primary cell cultures from humans, when testing the potential genotoxicity of chemicals. Using the comet assay, a panel of reference compounds showed that the ETC were found to detect the DNA-damaging effects with no remarkable difference to what has been reported in other cell types. Moreover, in comparison with a well-established rodent cell line, the mouse lymphoma L5178Y cells, the ETC showed similar sensitivity to the DNA damaging effects of the genotoxic agents hydrogen peroxide and catechol. Although there was an interindividual variation in induced DNA damage and the subsequent repair when using ETC from different blood donors, it did not seem to be of crucial importance for the identification of DNA-damaging agents. The demonstrated difference in sensitivity to catechol-induced DNA damage between freshly isolated peripheral lymphocytes and ETC may very well be due to their different proliferative status but despite this difference, both in vitro systems were able to identify catechol as a DNA-damaging agent at the same concentration.Based on these results, it is proposed that the ETC and the comet assay are a useful combination when testing for the potential DNA damaging effects of chemicals. Representing easily cultivated cells possessing the normal human karyotype, where one blood sample can be used for numerous experiments performed over a long time, extended-term cultures appear to be a useful alternative, both to transformed mammalian cell lines, and primary cell cultures from humans. In fact, the extended-term lymphocytes, with or without S9 and/or lesion specific DNA repair enzymes, should be used more frequently when screening for the potential genotoxicity of chemicals.
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| 7. |
- Andersson, Maria, et al.
(author)
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Evaluation of catechol-induced DNA damage in human lymphocytes : A comparison between freshly isolated lymphocytes and T-lymphocytes from extended-term cultures
- 2007
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In: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 21:4, s. 716-722
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Journal article (peer-reviewed)abstract
- Extended-term cultures of proliferating human T-lymphocytes (ETC) may be a practical alternative to freshly isolated non-proliferating peripheral blood lymphocytes (PBL) when studying genotoxicity in vitro. To investigate if the pattern of DNA damage differs between the two in vitro systems, catechol-induced DNA damage was evaluated in PBL and ETC derived from the same blood sample, using three different donors. DNA damage was monitored using the comet assay. Whereas 3 h of exposure to 0.5 mM catechol was found to be without DNA damaging effects, 3 mM was found to induce significant damage both in the PBL and the ETC (the latter being clearly less sensitive). The level of reactive oxygen species (ROS) was also measured in the ETC using the fluorescent probe carboxy-H2DCFA. ROS was found to be considerably increased both at 0.5 and 3 mM catechol. The demonstrated difference in sensitivity towards catechol-induced DNA damage between PBL and ETC may be due to their different proliferative status, but despite this difference both in vitro systems were able to identify catechol as a DNA damaging agent at the same concentration.
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| 8. |
- Andersson, Maria, et al.
(author)
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Interindividual differences in initial DNA repair capacity when evaluating H2O2-induced DNA damage in extended-term cultures of human lymphocytes using the comet assay
- 2007
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In: Cell Biology and Toxicology. - : Springer Science and Business Media LLC. - 0742-2091 .- 1573-6822. ; 23:6, s. 401-411
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Journal article (peer-reviewed)abstract
- It has been suggested that extended-term cultures of human lymphocytes could be used as a complement to cell lines based on transformed cells when testing the genotoxicity of chemicals. To investigate whether the pattern of induced DNA damage and its subsequent repair differs significantly between cultures based on different blood donors, hydrogen peroxide (H2O2)-induced DNA damage was measured in cultures from four different subjects using the comet assay. The DNA damage was significantly increased in all cultures after 10 min exposure to 0.25 mmol/L H2O2, and there was a significant decrease in the H2O2-induced DNA damage in all cultures after 30 min of DNA repair. The level of damage varied between the different donors, especially after the repair. Using PCR and DNA sequencing, exon 5 of the p53 gene was sequenced in the lymphocytes from the donors with the lowest and highest residual damage. No such mutation was found. Mouse lymphoma L5178Y cells carrying the p53 mutation in exon 5 were included as a reference. These cells were found to be less sensitive toward the H2O2-induced DNA damage, and they were also found to have a rather low DNA repair capacity. The demonstrated variation in H2O2-induced DNA damage and DNA repair capacity between the cultures from the different subjects may be important from a risk assessment perspective, but is obviously not of decisive importance when it comes to the development of a routine assay for genotoxicity.
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| 9. |
- Demma, Jemal, et al.
(author)
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Genotoxicity of plumbagin and its effects on catechol and NQNO-induced DNA damage in mouse lymphoma cells
- 2009
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In: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 23:2, s. 266-271
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Journal article (peer-reviewed)abstract
- Plumbagin, a naphtoquinone present in the roots of Plumbago zeylanica, has been reported to have many beneficial effects such as antibacterial, antifungal, anticancer, antimutagenic and antioxidant effects, but this compound has also been reported to have many side effects. Given the wide use of P. zeylanica in traditional medicine and the various potential therapeutic uses of plumbagin, the present study was carried out to further elucidate the potential genotoxicity and antigenotoxicity of plumbagin in mouse lymphoma L5178Y cells, using the comet assay. Without affecting the cell viability, plumbagin itself was found to induce significant DNA damage at concentrations as low as 0.25 ng/ml. When the cells were exposed to non-DNA damaging concentrations of plumbagin, together with NQNO (known to interact with DNA in many different ways) or catechol (known to induce oxidative DNA damage), plumbagin was found to significantly reduce the catechol-induced DNA damage, but to be without protective effect against the NQNO-induced damage. The fact that non-DNA damaging concentrations of plumbagin diminished the DNA damage induced by catechol, provides further support for the idea that plumbagin may act as an antioxidative agent at low concentrations.
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| 10. |
- Demma, Jemal, et al.
(author)
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Potential genotoxicity of plant extracts used in Ethiopian traditional medicine
- 2009
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In: Journal of Ethnopharmacology. - : Elsevier BV. - 0378-8741 .- 1872-7573. ; 122:1, s. 136-142
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Journal article (peer-reviewed)abstract
- Aim of the study: Although traditional herbal medicines are widely used in Ethiopia, no information is available on their potential genotoxicity. In the present study, hydroalcoholic extracts of Glinus lotoides, Plumbago zeylanica, Rumex steudelii and Thymus schimperi were evaluated for their DNA damaging effects using the comet assay. Material and methods: Mouse lymphoma L5178Y cells were exposed to different concentrations of the extracts for 3 h with and without metabolic activation (S9-mix) using 4-nitroquinoline-N-oxide and benzo(a)pyrene as positive controls, and vehicles as negative controls. Results: In the absence of S9, all extracts were found to induce significant DNA damage without affecting the cell viability. T schimperi and R. steudelii were the most potent DNA-damaging extracts, and G. lotoides and P. zeylanica the least potent. The addition of S9 had different effects on the DNA damage induced by the extracts: it lowered the DNA damaging effect of P. zeylanica, did not affect the DNA damaging effect of T. schimperi, and increased the DNA damaging effects of R. steudelii and G. lotoides. Conclusion: The findings of the present study suggest that all extracts evaluated have a genotoxic potential in vitro which needs to be substantiated by further studies.
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| 11. |
- Durling, Louise J. K., et al.
(author)
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Evaluation of the DNA damaging effect of the heat-induced food toxicant 5-hydroxymethylfurfural (HMF) in various cell lines with different activities of sulfotransferases
- 2009
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In: Food and Chemical Toxicology. - : Elsevier BV. - 0278-6915 .- 1873-6351. ; 47:4, s. 880-884
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Journal article (peer-reviewed)abstract
- 5-Hydroxymethylfurfural (HMF), a heat-induced food toxicant present in a vast number of food items, has been suggested to be genotoxic after being bioactivated by the sulfotransferase SULT1A1. The comet assay was used to evaluate the DNA damaging effect of HMF in cell lines with different activities of SULT1A1: two human cell lines (Caco-2, low activity; and HEK293, higher activity), one cell line from mouse (L5178Y, no activity) and two cell lines from Chinese hamster (V79, negligible activity; and V79-hP-PST, high activity of human SULT1A1). HMF induced significant DNA damage in all cell lines after 3 h exposure to 100 mM. Most sensitive were V79 and V79-hP-PST where HMF induced significant DNA damage at 25 mM. Consequently, in the present study we have shown that HMF is a DNA damaging agent in vitro independent of the activity of SULT1A1 in the cells. The HMF-induced DNA damage was only observed at rather high concentrations which usually was associated with a concomitant decrease in cell viability.
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| 12. |
- Erlendsson, Lýður S, et al.
(author)
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Barley as a green factory for the production of functional Flt3 ligand
- 2009
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In: Biotechnology Journal. - Weinheim : Wiley-VCH Verlag GmbH & Co. KGaA. - 1860-7314 .- 1860-6768. ; 5:2, s. 163-171
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Journal article (peer-reviewed)abstract
- Biologically active recombinant human Flt3 ligand was expressed and isolated from transgenic barley seeds. Its expression is controlled by a tissue specific promoter that confines accumulation of the recombinant protein to the endosperm tissue of the seed. The recombinant Flt3 ligand variant expressed in the seeds contains an HQ-tag for affinity purification on immobilized metal ion affinity chromatography (IMAC) resin. The tagged protein was purified from seed extracts to near homogeneity using sequential chromatography on IMAC affinity resin and cation exchange resin. We also show that the recombinant Flt3 ligand protein undergoes posttranslational modifications: it is a glycoprotein containing alpha-1,3-fucose and alpha-1,2-xylose. The HQ-tagged Flt3 ligand variant exhibits comparable biological activity to commercial Flt3 ligand. This is the first report showing expression and accumulation of recombinant human growth factor in barley seeds with a yield of active protein similar to a bacterial expression system. The present results demonstrate that plant molecular farming is a viable approach for the bioproduction of human-derived growth factors.
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| 13. |
- Hellman, Björn
(author)
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General Toxicology
- 2006
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In: Pharmaceutical Toxicology. - : Pharmaceutical Press, London. ; , s. 1-39
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Book chapter (peer-reviewed)
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| 14. |
- Hellman, Björn
(author)
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Genotoxicity
- 2006
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In: Pharmaceutical Toxicology. - : Pharmaceutical Press, London. ; , s. 105-121
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Book chapter (peer-reviewed)
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| 15. |
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| 16. |
- Johansson, K, et al.
(author)
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An analysis of Vigimed, a global E-mail system for the exchange of pharmacovigilance information
- 2007
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In: Drug Safety. - 0114-5916 .- 1179-1942. ; 30:10, s. 883-889
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Journal article (peer-reviewed)abstract
- Background and aim: The Internet provides novel ways for communication and data exchange between national regulators. One innovation was the introduction of Vigimed, an e-mail discussion forum for national pharmacovigilance centres (NPCs). We reviewed a sample of Vigimed messages to learn more about this new tool and about the problems encountered in everyday pharmacovigilance and how these are handled. Methods: We analysed the contents of 100 subsequent questions and the corresponding responses as stored in the Vigimed datafile. Results: To the 100 questions circulated through Vigimed, 575 answers were received; mean number of answers per question 6, range 0-20. Fifty-five (77%) of the 71 collaborating countries and 88 (43%) of the 204 individuals who had access in the study period had submitted at least one question or answer. These countries were in all parts of the world and in various phases of development. A total of 38% of the questions concerned the regulatory status of a drug; 30% safety issues; 13 % regulatory actions under consideration; and 10% drug use-related problems (more than one category possible). Of the questions, 89% concerned established drugs; 11% were classified as new. A total of 90% of the questions concerned specific active substances or drug groups. Of the drugs, 73% were classified as 'orthodox' and 9% as herbal; 4% were vaccines and 4% excipients. Emerging drug groups (anatomical therapeutic chemical codes) were NSAIDs and analgesics (M01, N02), antibacterials (J01), antiobesity drugs (A08), psychotropic drugs (N05) and antihistamines (R06). Discussion: NPCs operate in a restricted environment and there is little published information about the daily practices and experiences at NPCs. Our study concerned a sample in a limited period in time. In the meantime, the use of Vigimed has greatly expanded. The data in the Vigimed records are subjected to confidentiality in regard to the identities of countries, staff members, drug products and pharmaceutical companies, which tin-tits the presentation of data in a publication. For information about the actions taken to manage the matters and problems raised in Vigimed it would have been necessary to contact the NPCs and acquire follow-up data. Conclusions: The Vigimed e-mail discussion group was rapidly incorporated into the routines at NPCs in many countries around the world. When two or more persons per country have access, participation increases. The matters raised predominantly refer to regulatory policy, safety concerns and drug use-related problems, and mainly concern established drugs. The latter emphasises the need for persistent monitoring of all drugs. New safety concerns are often sensitive and uncertain; the timely and efficient communication of such suspicions benefits from an environment of confidentiality. The Vigimed records give a unique view of real-life pharmacovigilance, of the matters addressed, the problems encountered, the data needed and the ways in which NPCs help each other. Such information can help make pharmacovigilance more efficient and effective.
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| 17. |
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