| 1. |
- Ullerås, Erik, et al.
(författare)
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Development of the "Cell Chip" : a new in vitro alternative technique for immunotoxicity testing.
- 2005
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Ingår i: Toxicology. - : Elsevier BV. - 0300-483X .- 1879-3185. ; 206:2, s. 245-56
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Tidskriftsartikel (refereegranskat)abstract
- Predictive testing of immunotoxicity associated with chemical compounds is complicated and cannot be accomplished with a single test. As most of the existing tests for immunotoxicity employ experimental animals, there is an increasing need for alternative tests in vitro. We have developed a new system for in vitro immunotoxicity testing, which employs changes in cytokine expression observed in vitro as an endpoint indicating potential for perturbation of the immune system in vivo. This system named "fluorescent cell chip" (FCC) is based on a number of genetically modified cell lines that regulate the expression of a transgene coding for fluorescent protein enhanced green fluorescent protein (EGFP) in a similar way as they regulate expression of IL-1beta, IL-2, IL-4, IFN-gamma, IL-10, TNF-alpha, and beta-actin. Morphological and functional features of selected cell lines expressing EGFP under the control of cytokine promotors were compared with maternal cell lines and this comparison showed that critical functional features of the maternal cell lines were preserved in EGFP expressing cells. Two chemicals with known immunotoxic activities, cyclosporine A and potassium tetrachloro-platinate(II), mediated compound-specific pattern of inhibition and activation of reporter gene expression. Thus, the "fluorescent cell chip" has demonstrated potential for application as a predictive screening test for immunomodulatory activities of chemicals. The major advantage of this approach is the possibility to apply this test in high throughput screening of high number of compounds for their well defined biological activity.
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| 2. |
- Gradecka-Meesters, Dobroslawa, et al.
(författare)
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Assessment of the protective effects of selected dietary anticarcinogens against DNA damage and cytogenetic effects induced by benzo[a]pyrene in C57BL/6J mice
- 2011
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Ingår i: Food and Chemical Toxicology. - : Elsevier BV. - 0278-6915 .- 1873-6351. ; 49:8, s. 1674-1683
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Tidskriftsartikel (refereegranskat)abstract
- The protective action in C57BL/6J mice from orally administered ellagic acid (EA), benzyl isothiocyanate (BITC), an extract of epigallocatechins (Tegreen (R)) as well as chlorophyllin (CHL) against benzo[a]pyrene (B[a]P)-induced DNA damage and cytogenetic effects was investigated. In pilot experiment the comet assay indicated protective effects for all compounds, while such activity was confined to EA and CH with respect to B[a]P-DNA adducts and micronuclei. EA and CH were chosen for the main study where the levels of DNA adducts in liver after injection of 30 mg B[a]P/kg b.w. did not differ from those found for animals exposed to B[a]P and treated with the protective substances. In leukocytes no significant protective effect of CHL was detected while a 2-fold increase of adduct concentrations was observed after co-administration of EA. In the comet assay CHL or EA caused a 3-fold decrease of SSB, and a 2-fold decrease of FPG sites in comparison to animals treated with B[a]P. CHL or EA showed a significant protective effect against B[a]P-induced MN in polychromatic erythrocytes in bone marrow. In contrast, flow cytometry measurements in peripheral blood indicated the MN frequency after treatment with CHL or EA almost twice as high as that recorded for B[a]P alone.
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| 3. |
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| 4. |
- Kotova, Natalia, et al.
(författare)
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Genotoxicity of alcohol is linked to DNA replication-associated damage and homologous recombination repair
- 2013
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Ingår i: Carcinogenesis. - : Oxford University Press (OUP). - 0143-3334 .- 1460-2180. ; 34:2, s. 325-330
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Tidskriftsartikel (refereegranskat)abstract
- Although alcohol consumption is related to increased cancer risk, its molecular mechanism remains unclear. Here, we demonstrate that an intake of 10% alcohol for 4 weeks in rats is genotoxic due to induction of micronuclei. Acetaldehyde (AA), the first product of ethanol metabolism, is believed to be responsible for DNA damage induced by alcohol. Here, we observe that AA effectively blocks DNA replication elongation in mammalian cells, resulting in DNA double-strand breaks associated with replication. AA-induced DNA damage sites colocalize with the homologous recombination (HR) repair protein RAD51. HR measured in the hypoxhantineguaninefosforibosyltransferase (HPRT) gene is effectively induced by AA and recombination defective mammalian cells are hypersensitive to AA, clearly demonstrating that HR is essential in the repair of AA-induced DNA damage. Altogether, our data indicate that alcohol genotoxicity related to AA produces replication lesions on DNA triggering HR repair.
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