| 1. |
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| 2. |
- Andersson, Maria, et al.
(författare)
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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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Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 21:4, s. 716-722
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Andres, M I, et al.
(författare)
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Polygodial-induced noradrenaline release in human neuroblastoma SH-SY5Y cells.
- 1997
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Ingår i: Toxicology in Vitro. - 0887-2333 .- 1879-3177. ; 11:5, s. 509-11
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Tidskriftsartikel (refereegranskat)abstract
- Polygodial is a natural sesquiterpene which exhibits pronounced pungency and a powerful antifeedant activity. At low concentrations, which do not alter general cell membrane permeability, polygodial increases the intracellular concentration of free calcium ([Ca(2+)](i)). Sensory neurotransmission depends on noradrenaline (NA) release, and vesicular exocytosis, in turn, is dependent on an increase in [Ca(2+)](i). The nociceptive response induced by polygodial could therefore be directly linked to intracellular calcium levels. Consequently, the objective of this work was to investigate the effect of polygodial on NA release. The human neuroblastoma cell line SH-SY5Y was selected as an in vitro model for sensory neurones. Semiconfluent cells were preloaded with tritiated NA ([(3)H]NA). After 3 min exposure of polygodial to the cells, released and unreleased radioactivity were measured. Polygodial induced a significant [(3)H]NA release at concentrations between 0.1 and 0.5 mug/ml with a maximum effect at 0.2 mug/ml (40% increased release of [(3)H]NA as compared with unstimulated control cells). No polygodial-induced transmitter release was seen at 3.5 and 5 mug/ml. For comparison, carbachol (1 rim) increased [(3)H]NA release by 10% and the KCl-induced (100 mm) [(3)H]NA release increased by 8% as compared with unstimulated SH-SY5Y cells. In conclusion polygodial, at the concentrations 0.1-0.5 mug/ml (equal to 0.4-2 mum), induces NA release which is dependent on polygodial-induced increase in [Ca(2+)](i).
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| 4. |
- Asnake, Solomon, 1985-, et al.
(författare)
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The brominated flame retardants TBP-AE and TBP-DBPE antagonize the chicken androgen receptor and act as potential endocrine disrupters in chicken LMH cells
- 2015
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Ingår i: Toxicology in Vitro. - : Elsevier. - 0887-2333 .- 1879-3177. ; 29:8, s. 1993-2000
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Tidskriftsartikel (refereegranskat)abstract
- Increased exposure of birds to endocrine disrupting compounds has resulted in developmental and reproductive dysfunctions. We have recently identified the flame retardants, ally1-2,4,6-tribromophenyl ether (TBP-AE), 2-3-dibromopropy1-2,4,6-tribromophenyl ether (TBP-DBPE) and the TBP-DBPE metabolite 2-bromoallyI-2,4,6-tribromophenyl ether (TBP-BAE) as antagonists to both the human androgen receptor (AR) and the zebrafish AR. In the present study, we aimed at determining whether these compounds also interact with the chicken AR. In silico modeling studies showed that TBP-AE, TBP-BAE and TBP-DBPE were able to dock into to the chicken AR ligand-binding pocket. In vitro transfection assays revealed that all three brominated compounds acted as chicken AR antagonists, inhibiting testosterone induced AR activation. In addition, qRT-PCR studies confirmed that they act as AR antagonists and demonstrated that they also alter gene expression patterns of apoptotic, anti-apoptotic, drug metabolizing and amino acid transporter genes. These studies, using chicken LMH cells, suggest that TBP-AE, TBP-BAE and TBP-DBPE are potential endocrine disrupters in chicken.
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| 5. |
- Attoff, Kristina, et al.
(författare)
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Acrylamide affects proliferation and differentiation of the neural progenitor cell line C17.2 and the neuroblastoma cell line SH-SY5Y
- 2016
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Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 35, s. 100-111
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Tidskriftsartikel (refereegranskat)abstract
- Acrylamide is a well-known neurotoxic compound and people get exposed to the compound by food consumption and environmental pollutants. Since acrylamide crosses the placenta barrier, the fetus is also being exposed resulting in a risk for developmental neurotoxicity. In this study, the neural progenitor cell line C17.2 and the neuroblastoma cell line SH-SY5Y were used to study proliferation and differentiation as alerting indicators for developmental neurotoxicity. For both cell lines, acrylamide reduced the number of viable cells by reducing proliferation and inducing cell death in undifferentiated cells. Acrylamide concentrations starting at 10 fM attenuated the differentiation process in SH-SY5Y cells by sustaining cell proliferation and neurite outgrowth was reduced at concentrations from 10 pM. Acrylamide significantly reduced the number of neurons starting at 1 mu M and altered the ratio between the different phenotypes in differentiating C17.2 cell cultures. Ten micromolar of acrylamide also reduced the expression of the neuronal and astrocyte biomarkers. Although the neurotoxic concentrations in the femtomolar range seem to be specific for the SH-SY5Y cell line, the fact that micromolar concentrations of acrylamide seem to attenuate the differentiation process in both cell lines raises the interest to further investigations on the possible developmental neurotoxicity of acrylamide.
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| 6. |
- Bergquist, Jonas, et al.
(författare)
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Structure-activity relationships for unsaturated dialdehydes 8( *). Comparative effects of 10 sesquiterpenoids on the sea urchin gamete fertilization.
- 1993
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Ingår i: Toxicology in Vitro. - 0887-2333 .- 1879-3177. ; 7:3, s. 205-12
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Tidskriftsartikel (refereegranskat)abstract
- The effects of 10 sesquiterpenoids with unsaturated dialdehyde functionalities were studied on fertilization, first cleavage, and calcium permeability of egg membranes of sea urchin gametes. Fertilization was inhibited by nine compounds when sperm was exposed and by five compounds when eggs were exposed (50 mug/ml for 5 min). All compounds except one (9alpha-hydroxymerulidial) inhibited the first cleavage in a dose-response manner. Only one compound (velleral) increased the Ca(2+) permeability of egg membranes at 20 mug/ml. All compounds reduced to a varying extent the ATP-driven Ca(2+) sequestration by non-mitochondrial intracellular compartments. In general, when hydroxylated and non-hydroxylated derivatives of the compounds are compared, the hydroxylated ones present a lower toxicity when measuring fertilization and cleavage inhibition, and reduction of intracellular Ca(2+) sequestration.
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- De Jong, Wim H., et al.
(författare)
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Round robin study to evaluate the reconstructed human epidermis (RhE) model as an in vitro skin irritation test for detection of irritant activity in medical device extracts
- 2018
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Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 50, s. 439-449
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Tidskriftsartikel (refereegranskat)abstract
- Assessment of skin irritation is an essential component of the safety evaluation of medical devices. OECD Test Guideline 439 describes the use of reconstructed human epidermis (RhE) as an in vitro test system for classification of skin irritation by neat chemicals. An international round robin study was conducted to evaluate the RhE method for determination of skin irritant potential of medical device extracts. Four irritant polymers and three non-irritant controls were obtained or developed that had demonstrated their suitability to act as positive or negative test samples. The RhE tissues (EpiDerm™ and SkinEthic™ RHE) were dosed with 100 μL aliquots of either saline or sesame oil extract. Incubation times were 18 h (EpiDerm™) and 24 h (SkinEthic™ RHE). Cell viability reduction > 50% was indicative of skin irritation. Both the EpiDerm™ and SkinEthic™ RHE tissues were able to correctly identify virtually all of the irritant polymer samples either in the saline, sesame oil or both solvent extracts. Our results indicate that RhE tissue models can detect the presence of strong skin irritants at low levels in dilute medical device polymer extracts. Therefore, these models may be suitable replacements for the rabbit skin irritation test to support the biological evaluation of medical devices.
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| 11. |
- Dejongh, J, et al.
(författare)
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An Integrated Approach to the Prediction of Systemic Toxicity using Computer-based Biokinetic Models and Biological In vitro Test Methods : Overview of a Prevalidation Study Based on the ECITTS Project.
- 1999
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Ingår i: Toxicology in Vitro. - 0887-2333 .- 1879-3177. ; 13:4-5, s. 549-54
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Tidskriftsartikel (refereegranskat)abstract
- Chemical toxicity was estimated by integrating in vitro study results with physiologically-based biokinetic models for eight neurotoxic compounds (benzene, toluene, lindane, acrylamide, parathion/oxon, caffeine, diazepam and phenytoin). In vitro studies on general and specific neurotoxicity were performed and biotransformation and tissue-blood distribution studies were used in modelling the biokinetic behaviour of the compounds. Subsequently, neurotoxicity was estimated from the integrated in vitro and kinetic studies. These results were compared with in vivo data from the literature on minimal neurotoxicity for these compounds, such as lowest-observed-effect levels (LOELs). The discrepancy between estimated and experimental LOELs ranged from 2- to 10-fold. LOEL estimates for compounds with a relatively low toxicity were more accurate than for compounds with a relatively high toxicity. LOELs for the most active compounds could only be established after consideration of additional in vitro results from the literature. The present study has generated encouraging results on the risk assessment of chemicals from in vitro studies and computer simulations and has identified some key directions for future research.
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| 12. |
- Demma, Jemal, et al.
(författare)
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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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Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 23:2, s. 266-271
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Tidskriftsartikel (refereegranskat)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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| 13. |
- Dovinova, Ima, et al.
(författare)
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Main targets of tetraaza macrocyclic copper complex on L1210 murine leukemia cells
- 2002
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Ingår i: Toxicology in Vitro. - 1879-3177. ; 16:5, s. 491-498
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Tidskriftsartikel (refereegranskat)abstract
- Several metal complex agents have already been introduced into clinical tumor therapy and others are subject of antitumor studies. In this study we focused on the tetraaza macrocyclic copper complex (Cu(TAAB)Cl-2). We studied the influence of the substance on cell growth, cell cycle, membrane integrity, necrosis, apotosis and glutathione level on the leukemic cell line L1210 in 1-day (22 h) and 3-day (72 h) experiments. The metal complex shows a dose-dependent antiproliferative effect, without affecting cell cycle phases. The present results confirm that copper complex can damage plasmatic membranes and trigger apoptosis, and that after treatment of leukemic cells with the copper complex, glutathione levels were increased. (C) 2002 Elsevier Science Ltd. All rights reserved.
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| 14. |
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| 15. |
- Edenius, Maja, 1986, et al.
(författare)
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Delayed clearance of the pro-carcinogen benzo[a]pyrene in PLHC-1 cells when co-exposed to the antifungal drug clotrimazole and effects on the CYP1A biomarker
- 2024
-
Ingår i: Toxicology in vitro : an international journal published in association with BIBRA. - 1879-3177. ; 95
-
Tidskriftsartikel (refereegranskat)abstract
- Cytochrome P450 1A (CYP1A) is a key enzyme in the metabolism of the polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (BaP) in animals, and a biomarker for environmental PAH exposure. The common antimycotic imidazole drug clotrimazole (CLO) has been detected in the aquatic environment and likely co-exists with BaP. Like BaP, CLO can bind to CYP1A enzymes and can act as a CYP1A inhibitor. Co-exposure of BaP with CLO significantly delayed BaP elimination in a fish liver cell line (PLHC-1). Intracellular BaP concentration was 2.4 times higher after 6h in co-exposed cells, compared to cells exposed to BaP alone. Higher BaP concentrations in cells co-exposed to CLO positively correlated with CLO dose, indicating CLO-mediated delays in BaP clearance. After 24h, BaP was undetectable irrespective of CLO co-exposure. In contrast, intracellular CLO concentrations remained constant over the 72h experimental period. Co-exposure of BaP with CLO caused synergistic and time-dependent increases on the CYP1A biomarker both on CYP1A mRNA levels and on CYP1A enzyme activity, in accordance with an apparent delayed BaP elimination in the presence of CLO. These results indicate a toxicokinetic interaction between BaP and CLO on the CYP1A enzyme that delays metabolic clearance of BaP.
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| 16. |
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| 17. |
- Ekstrand-Hammarström, Barbro, et al.
(författare)
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Oxidative stress and cytokine expression in respiratory epithelial cells exposed to well-characterized aerosols from Kabul, Afghanistan
- 2013
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Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 27:2, s. 825-833
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Tidskriftsartikel (refereegranskat)abstract
- In this study aerosol samples collected in an Asian mega-city (Kabul, Afghanistan) were compared to PM samples collected in a European location with traffic (Umea, Sweden) and a reference urban dust material (SRM 1649b). The toxicity of each sample towards normal human bronchial epithelial (NHBE) cells and a human bronchial epithelial cell line (BEAS-2B) was tested along with their ability to induce reactive oxygen species (ROS) formation and inflammatory responses. The extracts' morphology and elemental composition was studied by SEM-EDXRF, and filter samples were analyzed for metals and organic compounds. The PM from Kabul contained a larger fraction of fine particles, 19 times more polyaromatic hydrocarbons (PAH) and 37 times more oxygenated PAH (oxy-PAH) compared to samples from timed. The PM-samples from Kabul and the reference material (SRM 1649b) induced significantly stronger oxidative stress responses than the samples from Umea. Furthermore, samples collected in Kabul induced significantly higher secretion of the cytokines IL-6, IL-8 and GM-CSF while SRM1649b induced a cytokine pattern more similar to samples collected in Umea. Several properties of the particles could potentially explain these differences, including differences in their size distribution and contents of PAH and oxy-PAH, possibly in combination with their relative transition metal contents.
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| 18. |
- Escher, Sylvia E., et al.
(författare)
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Integrate mechanistic evidence from new approach methodologies (NAMs) into a read-across assessment to characterise trends in shared mode of action
- 2022
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Ingår i: Toxicology in Vitro. - : Elsevier. - 0887-2333 .- 1879-3177. ; 79
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Tidskriftsartikel (refereegranskat)abstract
- Read-across approaches often remain inconclusive as they do not provide sufficient evidence on a common mode of action across the category members. This read-across case study on thirteen, structurally similar, branched aliphatic carboxylic acids investigates the concept of using human-based new approach methods, such as in vitro and in silico models, to demonstrate biological similarity.Five out of the thirteen analogues have preclinical in vivo studies. Three out of them induced lipid accumulation or hypertrophy in preclinical studies with repeated exposure, which leads to the read-across hypothesis that the analogues can potentially induce hepatic steatosis.To confirm the selection of analogues, the expression patterns of the induced differentially expressed genes (DEGs) were analysed in a human liver model. With increasing dose, the expression pattern within the tested analogues got more similar, which serves as a first indication of a common mode of action and suggests differences in the potency of the analogues.Hepatic steatosis is a well-known adverse outcome, for which over 55 adverse outcome pathways have been identified. The resulting adverse outcome pathway (AOP) network, comprised a total 43 MIEs/KEs and enabled the design of an in vitro testing battery. From the AOP network, ten MIEs, early and late KEs were tested to systematically investigate a common mode of action among the grouped compounds.The targeted testing of AOP specific MIE/KEs shows that biological activity in the category decreases with side chain length. A similar trend was evident in measuring liver alterations in zebra fish embryos. However, activation of single MIEs or early KEs at in vivo relevant doses did not necessarily progress to the late KE “lipid accumulation”. KEs not related to the read-across hypothesis, testing for example general mitochondrial stress responses in liver cells, showed no trend or biological similarity.Testing scope is a key issue in the design of in vitro test batteries. The Dempster-Shafer decision theory predicted those analogues with in vivo reference data correctly using one human liver model or the CALUX reporter assays.The case study shows that the read-across hypothesis is the key element to designing the testing strategy. In the case of a good mechanistic understanding, an AOP facilitates the selection of reliable human in vitro models to demonstrate a common mode of action. Testing DEGs, MIEs and early KEs served to show biological similarity, whereas the late KEs become important for confirmation, as progression from MIEs to AO is not always guaranteed.
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| 19. |
- Fic, A, et al.
(författare)
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Genome-wide gene expression profiling of low-dose, long-term exposure of human osteosarcoma cells to bisphenol A and its analogs bisphenols AF and S.
- 2015
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Ingår i: Toxicology in Vitro. - : Elsevier BV. - 1879-3177 .- 0887-2333. ; 29:5, s. 1060-1069
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Tidskriftsartikel (refereegranskat)abstract
- The bisphenols AF (BPAF) and S (BPS) are structural analogs of the endocrine disruptor bisphenol A (BPA), and are used in common products as a replacement for BPA. To elucidate genome-wide gene expression responses, estrogen-dependent osteosarcoma cells were cultured with 10nM BPA, BPAF, or BPS, for 8h and 3months. Genome-wide gene expression was analyzed using the Illumina Expression BeadChip. Three months exposure had significant effects on gene expression, particularly for BPS, followed by BPAF and BPA, according to the number of differentially expressed genes (1980, 778, 60, respectively), the magnitude of changes in gene expression, and the number of enriched biological processes (800, 415, 33, respectively) and pathways (77, 52, 6, respectively). 'Embryonic skeletal system development' was the most enriched bone-related process, which was affected only by BPAF and BPS. Interestingly, all three bisphenols showed highest down-regulation of genes related to the cardiovascular system (e.g., NPPB, NPR3, TXNIP). BPA only and BPA/BPAF/BPS also affected genes related to the immune system and fetal development, respectively. For BPAF and BPS, the 'isoprenoid biosynthetic process' was enriched (up-regulated genes: HMGCS1, PDSS1, ACAT2, RCE1, DHDDS). Compared to BPA, BPAF and BPS had more effects on gene expression after long-term exposure. These findings stress the need for careful toxicological characterization of BPA analogs in the future.
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| 20. |
- Folch, Jaume, et al.
(författare)
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Evaluation of transcriptional activity of caspase-3 gene as a marker of acute neurotoxicity in rat cerebellar granular cells
- 2010
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Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 24:2, s. 465-471
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Tidskriftsartikel (refereegranskat)abstract
- Caspase-3 is a key protein involved in the classical apoptosis mechanism in neurons, as in many other cells types. In the present research, we describe the transcriptional activity of caspase-3 gene as a marker of acute toxicity in a primary culture model of rat cerebellar granule neurons (CGNs). CGNs were incubated for 16h in complete medium containing the chemicals at three concentrations (10, 100 μM and 1 mM). A total of 48 different compounds were tested. Gene transcriptional activity was determined by low-density array assays, and by single Taqman caspase-3 assays. Results from the PCR arrays showed that the caspase-3 gene was up-regulated when CGNs were exposed to neurotoxic chemicals. Significative correlations were found between the transcriptional activity of caspase-3 and the activity of some other genes related to apoptosis, cell-cycle and ROS detoxification. In our experiments, acute exposure of CGNs to well-documented pro-apoptotic xenobiotics modulated significantly caspase-3 gene expression, whereas chemicals not related to apoptosis did not modify caspase-3 gene expression. In conclusion, acute exposure of CGNs to neurotoxic compounds modulates the transcriptional activity of genes involved in the classical apoptotic pathway, oxidative stress and cell-cycle control. Transcriptional activity of caspase-3 correlates significantly with these changes and it could be a good indicator of acute neurotoxicity.
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| 21. |
- Forreryd, Andy, et al.
(författare)
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Predicting skin sensitizers with confidence : Using conformal prediction to determine applicability domain of GARD
- 2018
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Ingår i: Toxicology in Vitro. - : Elsevier. - 0887-2333 .- 1879-3177. ; 48, s. 179-187
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Tidskriftsartikel (refereegranskat)abstract
- GARD - Genomic Allergen Rapid Detection is a cell based alternative to animal testing for identification of skin sensitizers. The assay is based on a biomarker signature comprising 200 genes measured in an in vitro model of dendritic cells following chemical stimulations, and consistently reports predictive performances similar to 90% for classification of external test sets. Within the field of in vitro skin sensitization testing, definition of applicability domain is often neglected by test developers, and assays are often considered applicable across the entire chemical space. This study complements previous assessments of model performance with an estimate of confidence in individual classifications, as well as a statistically valid determination of the applicability domain for the GARD assay. Conformal prediction was implemented into current GARD protocols, and a large external test dataset (n = 70) was classified at a confidence level of 85%, to generate a valid model with a balanced accuracy of 88%, with none of the tested chemical reactivity domains identified as outside the applicability domain of the assay. In conclusion, results presented in this study complement previously reported predictive performances of GARD with a statistically valid assessment of uncertainty in each individual prediction, thus allowing for classification of skin sensitizers with confidence.
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| 22. |
- Forsby, A, et al.
(författare)
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Neuronal in vitro models for the estimation of acute systemic toxicity.
- 2009
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Ingår i: Toxicology in vitro : an international journal published in association with BIBRA. - : Elsevier BV. - 1879-3177. ; 23:8, s. 1564-1569
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of the EU funded integrated project "ACuteTox" is to develop a strategy in which general cytotoxicity, together with organ-specific endpoints and biokinetic features, are taken into consideration in the in vitro prediction of oral acute systemic toxicity. With regard to the nervous system, the effects of 23 reference chemicals were tested with approximately 50 endpoints, using a neuronal cell line, primary neuronal cell cultures, brain slices and aggregated brain cell cultures. Comparison of the in vitro neurotoxicity data with general cytotoxicity data generated in a non-neuronal cell line and with in vivo data such as acute human lethal blood concentration, revealed that GABA(A) receptor function, acetylcholine esterase activity, cell membrane potential, glucose uptake, total RNA expression and altered gene expression of NF-H, GFAP, MBP, HSP32 and caspase-3 were the best endpoints to use for further testing with 36 additional chemicals. The results of the second analysis showed that no single neuronal endpoint could give a perfect improvement in the in vitro-in vivo correlation, indicating that several specific endpoints need to be analysed and combined with biokinetic data to obtain the best correlation with in vivo acute toxicity.
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| 23. |
- Fromell, Karin, et al.
(författare)
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The effect of airborne Palladium nanoparticles on human lung cells, endothelium and blood-A combinatory approach using three in vitro models
- 2023
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Ingår i: Toxicology in Vitro. - : Elsevier. - 0887-2333 .- 1879-3177. ; 89
-
Tidskriftsartikel (refereegranskat)abstract
- A better understanding of the mechanisms behind adverse health effects caused by airborne fine particles and nanoparticles (NP) is essential to improve risk assessment and identification the most critical particle exposures. While the use of automobile catalytic converters is decreasing the exhausts of harmful gases, concentrations of fine airborne particles and nanoparticles (NPs) from catalytic metals such as Palladium (Pd) are reaching their upper safe level. Here we used a combinatory approach with three in vitro model systems to study the toxicity of Pd particles, to infer their potential effects on human health upon inhalation. The three model systems are 1) a lung system with human lung cells (ALI), 2) an endothelial cell system and 3) a human whole blood loop system. All three model systems were exposed to the exact same type of Pd NPs. The ALI lung cell exposure system showed a clear reduction in cell growth from 24 h onwards and the effect persisted over a longer period of time. In the endothelial cell model, Pd NPs induced apoptosis, but not to the same extent as the most aggressive types of NPs such as TiO2. Similarly, Pd triggered clear coagulation and contact system activation but not as forcefully as the highly thrombogenic TiO2 NPs. In summary, we show that our 3-step in vitro model of the human lung and surrounding vessels can be a useful tool for studying pathological events triggered by airborne fine particles and NPs.
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| 24. |
- Galfi, Helen, et al.
(författare)
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Indicator bacteria and associated water quality constituents in stormwater and snowmelt from four urban catchments
- 2016
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Ingår i: Journal of Hydrology. - : Elsevier BV. - 0022-1694 .- 1879-2707. ; 539, s. 125-140
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Tidskriftsartikel (refereegranskat)abstract
- SummaryFour indicator bacteria were measured in association with physico-chemical constituents and selected inorganics during rainfall, baseflow and snowmelt periods in storm sewers of four urban catchments in a northern Swedish city. The variation patterns of coliforms, E. coli, enterococci and C. perfringens concentrations were assessed in manually collected grab samples together with those of phosphorus, nitrogen, solids, and readings of pH, turbidity, water conductivity, temperature and flow rates to examine whether these constituents with variation patterns similar to those of indicator bacteria, and to exclude the constituents with less similarity. In the reduced data set, the similarities were quantified by the clustering correlation analysis. Finally, the positive/negative relationships found between indicator bacteria and the identified associated constituent groups were described by multilinear regressions. In the order of decreasing concentrations, coliforms, E. coli and enterococci were found in the highest mean concentrations during both rainfall and snowmelt generated runoff. Compared to dry weather baseflow, concentrations of these three indicators in stormwater were 10 (snowmelt runoff) to 102 (rain runoff) times higher. C. perfringens mean concentrations were practically constant regardless of the season and catchment. The type and number of variables associated with bacteria depended on the degree of catchment development and the inherent complexity of bacteria sources. The list of variables associated with bacteria included the flow rate, solids with associated inorganics (Fe and Al) and phosphorus, indicating similar sources of constituents regardless of the season. On the other hand, bacteria were associated with water temperature only during rain periods, and somewhat important associations of bacteria with nitrogen and pH were found during the periods of snowmelt. Most of the associated constituents were positively correlated with bacteria responses, but conductivity, with two associated inorganics (Si and Sr), was mostly negatively correlated in all the catchments. Although the study findings do not indicate any distinct surrogates to indicator bacteria, the inclusion of the above identified constituents (flow rate, solids and total phosphorus for all seasons, water temperature for rainfall runoff, and total nitrogen and pH for snowmelt only) in sanitary surveys of northern climate urban catchments would provide additional insight into indicator bacteria sources and their modelling.
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| 25. |
- Hackett, JM, et al.
(författare)
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Optimal neural differentiation and extension of hybrid neuroblastoma cells (NDC) for nerve-target evaluations using a multifactorial approach
- 2010
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Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 24:2, s. 567-577
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Tidskriftsartikel (refereegranskat)abstract
- In vitro models of tissues, such as the cornea, represent systems for modeling cell-to-cell interactions and tissue function. The objective of this study was to develop an optimized nerve differentiation medium to incorporate into a 3D in vitro model to study innervation and cell targeting. A hybrid neuroblastoma cell line (NDC) was examined for its ability to differentiate into neurons, produce neurites, and functionally contact target cells. Neuronal differentiation of NDCs was optimized through a combinatorial approach which involved culturing cells in the presence of various extracellular matrices and soluble factors. A serum-free medium containing nerve growth factor (NGF), dimethyl sulfoxide (DMSO), or dexamethasone resulted in the greatest proportion of NDCs demonstrating a neuronal morphology. Similarly, with supplementation of cyclic AMP (cAMP) or NGF, neurite extension was optimized. Combining these factors generated an optimized differentiation and extension medium, relative to the individual components alone. In co-culture with epithelial cells, NDC neurites generated in the optimized medium formed contacts with epithelial targets and produced substance P. Similarly, NDCs seeded into a collagen matrix produced neurites that projected through the matrix to target epithelial cells, promoted epithelial stratification, and increased the rate of epithelial wound healing. As well, differentiated NDCs could target and alter acetylcholine receptor clustering in mouse C2C12 myotubes, demonstrating synaptic plasticity. Our data supports the use of NDCs, in combination with optimized medium, for generating an innervated in vitro model. (C) 2009 Elsevier Ltd. All rights reserved.
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| 26. |
- Hagvall, Lina, 1978, et al.
(författare)
-
Skin permeation of nickel, cobalt and chromium salts in ex vivo human skin, visualized using mass spectrometry imaging
- 2021
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 76
-
Tidskriftsartikel (refereegranskat)abstract
- Skin permeation and distribution of three of the most common skin sensitizers was investigated using a previously developed animal-free exposure method combined with imaging mass spectrometry. Nickel, cobalt, and chromium (III) salts were dissolved in a buffer and exposed to human skin ex vivo, to be analyzed using time of flight secondary ion mass spectrometry (ToF-SIMS). Our findings demonstrate that metal haptens mainly accumulated in the stratum corneum, however all three metal sensitizers could also be detected in the epidermis. Cobalt and chromium (III) species penetrated into the epidermis to a larger extent than nickel species. The degree of penetration into the epidermis is suggested to be affected by the sensitization potency of the metal salts, as well as their speciation, i.e. the amount of the respective metal present in the solution as bioaccessible and solubilised ions. Our method provided permeation profiles in human skin for known sensitizers, on a level of detail that is not possible to achieve by other means. The findings show that the permeation profiles are different, despite these sensitizers being all metal ions and common causes of contact allergy. Studying skin uptake by only considering penetration through the skin might therefore not give accurate results.
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| 27. |
- Hagvall, Lina, 1978, et al.
(författare)
-
Skin permeation studies of chromium species-Evaluation of a reconstructed human epidermis model
- 2023
-
Ingår i: Toxicology in Vitro. - 0887-2333 .- 1879-3177. ; 91
-
Tidskriftsartikel (refereegranskat)abstract
- A reconstructed human epidermis (RHE) model, the EpiDerm, was investigated and compared to human skin ex vivo regarding tissue penetration and distribution of two chromium species, relevant in both occupational and general exposure in the population. Imaging mass spectrometry was used in analysis of the sectioned tissue. The RHE model gave similar results compared to human skin ex vivo for skin penetration of CrVI. However, the penetration of CrIII into the tissue of the RHE model compared to human skin ex vivo differed markedly, such that in the RHE model the CrIII species accumulated in the tissue layer corresponding to stratum corneum whereas in human skin ex vivo, the CrIII species penetrated evenly through the skin tissue. Further, skin lipids such as cholesterol were less abundant in the RHE model compared to the human skin tissue. Results presented here indicate that the RHE models do not possess the same fundamental properties as human skin tissue. As the RHE models appear to be able to give false negative results, experiments using RHE models for the study of skin penetration should be evaluated with caution.
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| 28. |
- Hamm, Jon, et al.
(författare)
-
Alternative approaches for identifying acute systemic toxicity : Moving from research to regulatory testing
- 2017
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 41, s. 245-259
-
Forskningsöversikt (refereegranskat)abstract
- Acute systemic toxicity testing provides the basis for hazard labeling and risk management of chemicals. A number of international efforts have been directed at identifying non-animal alternatives for in vivo acute systemic toxicity tests. A September 2015 workshop, Alternative Approaches for Identifying Acute Systemic Toxicity: Moving from Research to Regulatory Testing, reviewed the state-of-the-science of non-animal alternatives for this testing and explored ways to facilitate implementation of alternatives. Workshop attendees included representatives from international regulatory agencies, academia, nongovernmental organizations, and industry. Resources identified as necessary for meaningful progress in implementing alternatives included compiling and making available high-quality reference data, training on use and interpretation of in vitro and in silico approaches, and global harmonization of testing requirements. Attendees particularly noted the need to characterize variability in reference data to evaluate new approaches. They also noted the importance of understanding the mechanisms of acute toxicity, which could be facilitated by the development of adverse outcome pathways. Workshop breakout groups explored different approaches to reducing or replacing animal use for acute toxicity testing, with each group crafting a roadmap and strategy to accomplish near-term progress. The workshop steering committee has organized efforts to implement the recommendations of the workshop participants.
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| 29. |
- Hassan, Saadia B., et al.
(författare)
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Primary lymphocytes as predictors for species differences in cytotoxic drug sensitivity
- 2007
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Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 21:6, s. 1174-1181
-
Tidskriftsartikel (refereegranskat)abstract
- Several in vitro methods have been suggested to predict drug-induced haematotoxicity and species differences; the most commonly used being the clonogenic CFU-GM assay. The aim of the current study was to evaluate whether primary lymphocytes from peripheral blood, assayed with a short-term non-clonogenic assay, could be used to detect species differences in drug sensitivity, and offer an alternative to the CFU-GM assay. The effect of 17 different cytotoxic drugs on lymphocytes from human, dog, rat and mouse was evaluated. A higher sensitivity of human than mouse lymphocytes was seen for topotecan and for 3 of 5 antimetabolites tested. Clear species specificity was also seen for the proteasome inhibitor bortezomib where rodent cells were 50–300 times less sensitive than human cells. Good agreement between our data and published CFU-GM data was observed, suggesting that primary lymphocytes may be a useful model for species difference screening in drug development.
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| 30. |
- Hedberg, Daniel, 1976, et al.
(författare)
-
Effects of Roundup and glyphosate formulations on intracellular transport, microtubules and actin filaments in Xenopus laevis melanophores.
- 2009
-
Ingår i: Toxicology in vitro : an international journal published in association with BIBRA. - : Elsevier BV. - 1879-3177.
-
Tidskriftsartikel (refereegranskat)abstract
- Glyphosate containing herbicides, such as Roundup, are commonly used and generally considered to be safe. However, some toxic effects are found on amphibians in vivo and human and mouse cells in vitro. In this study the effects of Roundup, glyphosate, glyphosateisopropylamine and isopropylamine were studied on intracellular transport by measuring aggregation capacity in Xenopus laevis melanophores. The chemicals inhibited retrograde transport of melanosomes in the range of 0.5-5mM. Cellular morphology and localization of microtubules and actin filaments were affected as determined by immunocytochemistry. Both glyphosate and Roundup decreased pH in the media. Acidic pH inhibited melanosome transport and altered microtubule and actin morphology in the absence of chemicals, while transport inhibiting concentrations of glyphosate, Roundup and glyphosateisopropylamine disassembled both microtubules and actin filaments. At physiological pH the effects of Roundup decreased whereas glyphosate failed to inhibit transport. Physiological pH decreases glyphosate lipophilicity and its diffusion into the cytoplasm. The Roundup formulation contains surfactants, such as POEA (polyetylated tallow amine) that increases membrane permeability allowing cellular uptake at physiological pH. Our results show that the effects of glyphosate containing compounds are pH-dependent and that they inhibit intracellular transport through disassembly of the cytoskeleton possibly by interfering with intracellular Ca(2+)-balance.
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| 31. |
- Herlin, Maria, et al.
(författare)
-
Inhibitory effects on osteoblast differentiation in vitro by the polychlorinated biphenyl mixture Aroclor 1254 are mainly associated with the dioxin-like constituents.
- 2015
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 1879-3177 .- 0887-2333. ; 29:5, s. 876-883
-
Tidskriftsartikel (refereegranskat)abstract
- The polychlorinated biphenyl (PCB) mixture Aroclor 1254 alters bone tissue properties. However, the mechanisms responsible for the observed effects have not yet been clarified. This study compared the effect of Aroclor 1254 on the expression of osteoblast differentiation markers in MC3T3-E1 cells with the corresponding effect of the dioxin reference compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and two PCB congeners belonging to the category of non-dioxin-like PCBs. The aim of the study was to quantify the relative influence of dioxin-like and non-dioxin-like PCB-components on osteoblast differentiation. Expression of marker genes for AhR activity and osteoblast differentiation were analyzed, and relative potency (REP) values were derived from Benchmark concentration-effect curves. Expression of alkaline phosphatase and osteocalcin were decreased by both Aroclor 1254 and TCDD exposure, while the PCB-congeners PCB19 and PCB52 slightly induced the expression. The relative potency of Aroclor 1254 for inhibitory effects on osteoblast differentiation marker genes was within the expected range as estimated from the chemical composition of Aroclor 1254. These results are consistent with previously observed bone modulations following in vivo exposure to Aroclor 1254 and TCDD, and demonstrate that the inhibitory effects of Aroclor 1254 on osteoblast differentiation by the dioxin-like constituents are over-riding the contribution of non-dioxin-like PCBs.
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| 32. |
- Holmgren, Gustav, 1983-, et al.
(författare)
-
MicroRNAs as potential biomarkers for doxorubicin-induced cardiotoxicity
- 2016
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 34, s. 26-34
-
Tidskriftsartikel (refereegranskat)abstract
- Anthracyclines, such as doxorubicin, are well-established, highly efficient anti-neoplastic drugs used for treatment of a variety of cancers, including solid tumors, leukemia, lymphomas, and breast cancer. The successful use of doxorubicin has, however, been hampered by severe cardiotoxic side-effects. In order to prevent or reverse negative side-effects of doxorubicin, it is important to find early biomarkers of heart injury and drug-induced cardiotoxicity. The high stability under extreme conditions, presence in various body fluids, and tissue specificity, makes,microRNAs very suitable as clinical.biomarkers. The present study aimed towards evaluating the early and late effects of doxorubicin on the microRNA expression in cardiomyocytes derived from human pluripotent stem cells. We report on several microRNAs, including miR-34a, miR-34b, miR-187, miR-199a, miR-199b, miR-146a, miR-15b, miR-130a, miR-214, and miR-424, that are differentially expressed upon, and after, treatment with doxorubicin. Investigation of the biological relevance of the identified microRNAs revealed connections to cardiomyocyte function and cardiotoxicity, thus supporting the findings of these microRNAs as potential biomarkers for drug-induced cardiotoxicity.
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| 33. |
- Holst, Martina, et al.
(författare)
-
Comparison of three cytotoxicity tests in the evaluation of the cytotoxicity of a spermine analogue on human breast cancer cell lines
- 2005
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 1879-3177 .- 0887-2333. ; 19:3, s. 379-387
-
Tidskriftsartikel (refereegranskat)abstract
- Using three cytotoxicity assays, we have investigated the effect of the spermine analogue N1,N11-diethylnorspermine (DENSPM)on four human breast cancer cell lines with different known genetic lesions. Cells were seeded in 96 well plates and DENSPM was added 24 h later to give final concentrations from 0.1 to 100 microM. At 24, 48 and 72 h of treatment, the protein content was determined with a modified Lowry assay. Mitochondrial activity was determined with the AlamarBlue and MTT assays. These two assays differ with respect to where in the electron transport chain the reduction of the substrate takes place. Treatment with increasing concentrations of DENSPM resulted in differential responses in the four cell lines. There was a good of agreement between the protein content and the MTT assay showing increased negative effect with increased dose of DENSPM. The AlamarBlue assay on the other hand showed a stimulation of substrate reduction compared to control at DENSPM concentrations that were inhibitory according to the protein content and MTT assay. Thus, the data clearly show that the MTT and AlamarBlue assays are not equivalent. Importantly, the AlamarBlue assay presumably also reflects cytoplasmic reduction of the substrate through DENSPM-induced mechanisms.
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| 34. |
- Johansson, Henrik, et al.
(författare)
-
The GARD assay for assessment of chemical skin sensitizers.
- 2013
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 1879-3177 .- 0887-2333. ; 27:3, s. 1163-1169
-
Tidskriftsartikel (refereegranskat)abstract
- Allergic contact dermatitis is a skin disease caused by an immunologic reaction to low molecular weight compounds, so called haptens. These substances are commonly present in products used by humans in daily life, such as in cosmetics and fragrances, as well as within chemical industry and in pharmaceuticals. The frequent usage of these compounds in different applications has led to increasing incidences of allergic contact dermatitis, which has become a substantial economic burden for society. As a consequence, chemicals are routinely tested for their ability to induce skin sensitization, using animal models such as the murine Local Lymph Node Assay. However, recent legislations regulate the use of animal models within chemical testing. Thus, there is an urgent need for in vitro alternatives to replace these assays for safety assessment of chemicals. Recently, we identified a signature of predictive genes, which are differentially regulated in the human myeloid cell-line MUTZ-3 when stimulated with sensitizing compounds compared to non-sensitizing compounds. Based on these findings, we have formulated a test strategy for assessment of sensitizing compounds, called Genomic Allergen Rapid Detection, GARD. In this paper, we present a detailed method description of how the assay should be performed.
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| 35. |
- Johansson, M., et al.
(författare)
-
Effects of 3-MeSO2-DDE and some CYP inhibitors on glucocorticoid steroidogenesis in the H295R human adrenocortical carcinoma cell line
- 2002
-
Ingår i: Toxicology in Vitro. - 0887-2333 .- 1879-3177. ; 16:2, s. 113-121
-
Tidskriftsartikel (refereegranskat)abstract
- The formation of steroids in the H295R human adrenocortical carcinoma cell line was analysed by HPLC or RIA, and based on these data the apparent catalytic activities of CYP11A, CYP17, CYP21 and CYP11B1 in this cell line were calculated. The environmental pollutant 3-methylsulfonyl-DDE (3-MeSO2-DDE) and the cytochrome P450 (CYP) inhibitors ketoconazole, metyrapone and aminoglutethimide were studied for their effects on the steroid formation. Metyrapone (IC50) of 1 microM) and 3-MeSO2-DDE (10 microM: 66 +/- 10% of control) were found to inhibit the apparent CYP11B1 activity. Ketoconazole inhibited all enzymes examined with the greatest effects on CYP11B1 (IC50) of 2.5 microM). Aminoglutethimide was examined only for effects on CYP11A activity and was shown to inhibit pregnenolone formation (20 microM: 61 +/- 4% of control). The possibility of studying all CYP enzymes in the corticosteroidogenesis makes this cell line a valuable test system to examine effects of chemicals, such as suspected endocrine disruptors, on the human glucocorticoid hormone synthesis. The inhibition of cortisol formation by 3-MeSO2-DDE supports an interaction with the active site of CYP11B1, as previously reported in mouse adrenocortical Y1 cells. In mice, this interaction led to metabolic activation and a high adrenotoxicity of 3-MeSO2-DDE. Therefore studies on the adrenotoxicity of 3-MeSO2-DDE in humans are needed.
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| 36. |
- Kotova, Natalia, et al.
(författare)
-
A novel micronucleus in vitro assay utilizing human hematopoietic stem cells
- 2015
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 29:7, s. 1897-1905
-
Tidskriftsartikel (refereegranskat)abstract
- The induction of micronucleated reticulocytes in the bone marrow is a sensitive indicator of chromosomal damage. Therefore, the micronucleus assay in rodents is widely used in genotoxicity and carcinogenicity testing. A test system based on cultured human primary cells could potentially provide better prediction compared to animal tests, increasing patient safety while also implementing the 3Rs principle, i.e. replace, reduce and refine. Hereby, we describe the development of an in vitro micronucleus assay based on animal-free ex vivo culture of human red blood cells from hematopoietic stem cells. To validate the method, five clastogens with direct action, three clastogens requiring metabolic activation, four aneugenic and three non-genotoxic compounds have been tested. Also, different metabolic systems have been applied. Flow cytometry was used for detection and enumeration of micronuclei. Altogether, the results were in agreement with the published data and indicated that a sensitive and cost effective in vitro assay to assess genotoxicity with a potential to high-throughput screening has been developed.
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| 37. |
- Lindegren, H., et al.
(författare)
-
Anionic linear aliphatic surfactants activate TRPV1 : a possible endpoint for estimation of detergent induced eye nociception?
- 2009
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 23:8, s. 1472-1476
-
Tidskriftsartikel (refereegranskat)abstract
- The transient receptor potential vanilloid type 1 (TRPV1) has been reported as one of the key components in the pain pathway. Activation of the receptor causes a Ca2+ influx in sensory C-fibres with secondary effects leading to neurogenic inflammation in the surrounding tissue. We have earlier reported specific activation of TRPV1 by surfactant-containing hygiene products. We have continued this project by investigating activation of the TRPV1 by shampoo and soap ingredients in low concentrations measured as intracellular Ca2+ influxes in stably TRPV1-expressing neuroblastoma SH-SY5Y cells. As a TRPV1 specific control, the TRPV1 antagonist capsazepine was used. The response was quantified as the product induced Ca2+ influx during 2 min in relation to the maximum response induced by the TRPV1 agonist capsaicin. The results show that anionic alkyl linear surfactant ingredients such as sodium lauryl sulphate, sodium laureth sulphate, ammonium lauryl sulphate, sodium C12-15 pareth sulphate and N-lauroylsarcosine concentration-dependently induced Ca2+ influx that could be addressed to TRPV1. The cationic surfactants benzalkonium chloride and cetylpyridinium chloride induced a Ca2+ influx that was not TRPV1 mediated as well as the zwitterionic surfactant cocamidopropyl betaine, the non-linear anionic surfactant sodium deoxycholate and the non-ionic surfactant Triton-X. These results reveal a new mechanistic pathway for surfactant-induced nociception.
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| 38. |
- Ljungberg, Liza, et al.
(författare)
-
Effects of nicotine, its metabolites and tobacco extracts on human platelet function in vitro
- 2013
-
Ingår i: Toxicology in Vitro. - Oxford, United Kingdom : Elsevier. - 0887-2333 .- 1879-3177. ; 27:2, s. 932-938
-
Tidskriftsartikel (refereegranskat)abstract
- Cigarette smoking is a leading cause of cardiovascular disease. The cardiovascular effects of smoking are probably multifactorial, including effects on platelets. Previous reports investigating the effects of nicotine and tobacco on platelet function are inconsistent.The present study investigated in vitro effects of nicotine, its major metabolites, tobacco extracts and extract of tobacco-free snuff on human platelets.None of the metabolites cotinine, cotinine-N-oxide, nicotine-1′-N-oxide or trans-3′-hydroxycotinine (0.1–10 μM) affected platelet aggregation or P-selectin expression. Nicotine (10 μM) weakly increased platelet aggregation, whereas trans-3′-hydroxycotinine (0.1 μM) and nicotine-1′-N-oxide (1–10 μM) weakly inhibited adhesion to fibrinogen. To elucidate the influence of other tobacco compounds, we investigated the impact of moist tobacco and smoke extracts on platelet function. Filtered extracts of oral snuff, cigarette smoke and tobacco free snuff inhibited platelet adhesion concentration-dependently. The inhibitory effects of tobacco extracts on platelet adhesion were independent of nicotine content and the nitric-oxide-pathway and not mediated through a platelet-nicotine-receptor.Taken together, tobacco extracts inhibit platelet activation during short-term in vitro challenge. As only limited effects of nicotine and nicotine metabolites were seen, the tobacco-induced platelet inhibition are likely induced by other compounds present in tobacco and tobacco free snuff.
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| 39. |
- Lundqvist, Jessica, et al.
(författare)
-
Optimisation of culture conditions for differentiation of C17.2 neural stem cells to be used for in vitro toxicity tests
- 2013
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 27:5, s. 1565-1569
-
Tidskriftsartikel (refereegranskat)abstract
- Here we present a multipotent neuronal progenitor cell line for toxicity testing as an alternative to primary cultures of mixed cell types from brain tissue. The v-myc immortalised C17.2 cell line, originally cloned from mouse cerebellar neural stem cells, were maintained as monolayer in cell culture dishes in DMEM supplemented with fetal calf serum, horse serum and antibiotics. Different media and exposure scenarios were used to induce differentiation. The optimal condition which generated mixed cultures of neurons and astrocytes included serum-free DMEM:F12 medium with N2 supplements, brain-derived neurotrophic factor and nerve growth factor. The medium was changed every 3rd or 4th day to fresh N2 medium with supplements. After 7days, the culture contained two different morphological cell types, assumed to be neurons and glia cells. The presence of astrocytes and neurons in the culture was confirmed by RT-PCR and Western blot analyses, indicating increased mRNA and protein levels of the specific biomarkers glial fibrillary acidic protein (GFAP) and βIII-tubulin, respectively. Concomitantly, the expression of the neural progenitor cell marker nestin was down-regulated.
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| 40. |
- Malakpour Permlid, Atena, et al.
(författare)
-
Unique animal friendly 3D culturing of human cancer and normal cells
- 2019
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 1879-3177 .- 0887-2333. ; 60, s. 51-60
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional cell culturing has proven inadequate as a reliable preclinical tumour model due to many inherent limitations. Hence, novel three-dimensional (3D) cell culture models are needed, which in many aspects can mimic a native tumour with 3D extracellular matrix. Here, we present a 3D electrospun polycaprolactone (PCL) mesh mimicking the collagen network of tissue. The naturally hydrophobic PCL mesh was subjected to O2 plasma treatment to obtain hydrophilic fibres. Biocompatibility tests performed using L929 fibroblasts show that the 3D PCL fibre unit compartments were non-toxic. The human breast cancer cell lines MCF-7 and JIMT-1, the normal-like human breast cell line MCF-10A, and human adult fibroblast were cultured in PCL meshes and cell proliferation was monitored using the AlamarBlue® assay. Confocal microscopy and cryosectioning show that the cells penetrated deep into the fibre mesh within 1 week of cell culturing. The cancer cells form spheroids with the cells attaching mainly to each other and partly to the fibres. The human adult fibroblasts stretch out along the fibres while the MCF-10A cells stretch between fibres. Overall, we show that normal and cancer cells thrive in the 3D meshes cultured in fetal bovine free medium which eliminates the use of collagen as an extracellular matrix support.
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| 41. |
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| 42. |
- Munem, Marwa, 1986, et al.
(författare)
-
Animal- free skin permeation analysis using mass spectrometry imaging
- 2021
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 71
-
Tidskriftsartikel (refereegranskat)abstract
- Here we demonstrate an animal-free skin permeation analytical approach suitable for testing pharmaceuticals, cosmetics, occupational skin hazards and skin allergens. The method aims to replace or significantly reduce existing in-vivo models and improve on already established in-vitro models. This by offering a more sensitive and flexible analytical approach that can replace and/or complement existing methods in the OECD guidelines for skin adsorption (no 427 and no 428) and measure multiple compounds simultaneously in the skin while being able to also trace endogenous effects in cells. We demonstrate this here by studying how active ingredients in sunscreen permeate through left-over human skin, from routine surgery, in a in a Franz-cell permeation model. Two common sunscreens were therefore applied to the human skin and Time of flight secondary ion mass spectrometry (ToF-SIMS) was used to trace the molecules through the skin. We show that that ToF-SIMS imaging can be applied in visualizing the distribution of Avobenzone, Bemotrizinol, Biscotrizole and Ethyl hexyl triazine at subcellular resolution in the skin. The UV-blockers could be visualized at the same time in one single experiment without any probes or antibodies used. The UV-blockers mostly remained in the stratum corneum. However, in certain features of the skin, such as sebaceous glands, the penetration of the UV-blockers was more prominent, and the compounds reached deeper into the epidermis.
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| 43. |
- Nordin-Andersson, M, et al.
(författare)
-
Neurite degeneration in differentiated human neuroblastoma cells.
- 1998
-
Ingår i: Toxicology in Vitro. - 0887-2333 .- 1879-3177. ; 12:5, s. 557-60
-
Tidskriftsartikel (refereegranskat)abstract
- We have studied neurite degeneration in differentiated human neuroblastoma (SH-SY5Y) cells. The axonopathy-inducing potency in vitro of caffeine, diazepam, methylmercury chloride (MeHg), triethyltin chloride (TET) and acrylamide (ACR) was elucidated. After 72 hours of exposure the neurite degeneration was determined (by morphological quantification) as well as the total protein content (general cytotoxicity). The concentrations that caused 20% reduction of number of neurites (ND(20)) for ACR (250+/-36 mum) and TET (0.097+/-0.03 mum) was significantly lower, 63% and 35%, respectively (P
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| 44. |
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| 45. |
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| 46. |
- Pellevoisin, C., et al.
(författare)
-
Pre-validation of SENS-IS assay for in vitro skin sensitization of medical devices
- 2021
-
Ingår i: Toxicology in Vitro. - : Elsevier Ltd. - 0887-2333 .- 1879-3177. ; 71
-
Tidskriftsartikel (refereegranskat)abstract
- According to ISO 10993-1:2018, the skin sensitization potential of all medical devices must be evaluated, and for this endpoint ISO 10993-10:2010 recommends the use of in vivo assays. The goal of the present study was to determine if the in vitro SENS-IS assay could be a suitable alternative to the current in vivo assays. The SENS-IS assay uses the Episkin Large and SkinEthic RHE reconstructed human epidermis models to evaluate marker genes. In our study, the SENS-IS assay correctly identified 13 sensitizers spiked in a non-polar solvent. In a subsequent analysis six medical device silicone samples previously impregnated with sensitizers were extracted with polar and non-polar solvents. The SENS-IS assay correctly identified five of these extracts, while a sixth extract, which contained the weak sensitizer phenyl benzoate, was classified as negative. However, when this extract was concentrated, or a longer exposure time was used, the assay was able to detect phenyl benzoate. The SENS-IS assay was transferred to a naïve laboratory which correctly identified sensitizers in six blinded silicone samples, including the one containing phenyl benzoate. In light of these results, we conclude that the SENS-IS assay is able to correctly identify the presence of sensitizers in medical devices extracts.
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| 47. |
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| 48. |
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| 49. |
- Popova, Dina, et al.
(författare)
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A fluorescence microplate screen assay for the detection of neurite outgrowth and neurotoxicity using an antibody against βIII-tubulin
- 2014
-
Ingår i: Toxicology in Vitro. - : Elsevier. - 0887-2333 .- 1879-3177. ; 28:3, s. 411-418
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Tidskriftsartikel (refereegranskat)abstract
- The majority of environmental and commercial chemicals have not been evaluated for their potential to cause neurotoxicity. We have investigated if neuron specific anti-βIII-tubulin antibodies are useful in a microplate assay of neurite outgrowth of retinoic acid-induced neurons from mouse P19 embryonal carcinoma cells. By incubating the P19-derived neurons with the primary anti-βIII-tubulin antibody and a secondary Alexa Fluor 488-conjugated antibody, followed by measuring the fluorescence in a microplate reader, a time-dependent increase in anti-βIII-tubulin immunofluorescence was observed. The relative fluorescence units increased by 4.3-fold from 2 to 10 days in culture. The results corresponded well with those obtained by semi-automatic tracing of neurites in fluorescence microscopy images of βIII-tubulin-labeled neurons. The sensitivity of the neurite outgrowth assay using a microplate reader to detect neurotoxicity produced by nocodazole, methyl mercury chloride and okadaic acid was significantly higher than for a cell viability assay measuring intracellular fluorescence of calcein-AM. The microplate-based method to measure toxicity targeting neurites using anti-βIII-tubulin antibodies is however less sensitive than the extracellular lactate dehydrogenase activity assay to detect general cytotoxicity produced by high concentrations of clomipramine, or glutamate-induced excitotoxicity. In conclusion, the fluorescence microplate assay for the detection of neurite outgrowth by measuring changes in βIII-tubulin immunoreactivity is a rapid and sensitive method to assess chemical- or toxin-induced neurite toxicity.
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| 50. |
- Prieto, P., et al.
(författare)
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The value of selected in vitro and in silico methods to predict acute oral toxicity in a regulatory context : Results from the European Project ACuteTox
- 2013
-
Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 27:4, s. 1357-1376
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Tidskriftsartikel (refereegranskat)abstract
- ACuteTox is a project within the 6th European Framework Programme which had as one of its goals to develop, optimise and prevalidate a non-animal testing strategy for predicting human acute oral toxicity. In its last 6 months, a challenging exercise was conducted to assess the predictive capacity of the developed testing strategies and final identification of the most promising ones. Thirty-two chemicals were tested blind in the battery of in vitro and in silico methods selected during the first phase of the project. This paper describes the classification approaches studied: single step procedures and two step tiered testing strategies. In summary, four in vitro testing strategies were proposed as best performing in terms of predictive capacity with respect to the European acute oral toxicity classification. In addition, a heuristic testing strategy is suggested that combines the prediction results gained from the neutral red uptake assay performed in 3T3 cells, with information on neurotoxicity alerts identified by the primary rat brain aggregates test method. Octanol-water partition coefficients and in silico prediction of intestinal absorption and blood-brain barrier passage are also considered. This approach allows to reduce the number of chemicals wrongly predicted as not classified (LD50 > 2000 mg/kg b.w.).
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