The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Bernd Sures - One of the best experts on this subject based on the ideXlab platform.
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effects of silver nitrate and silver nanoparticles on a planktonic community general trends after short term exposure
PLOS ONE, 2014Co-Authors: Jens Boenigk, Daniela Beisser, Sonja Zimmermann, Christina Bock, Jurij Jakobi, Daniel Grabner, Lars Grosmann, Sven Rahmann, Stephan Barcikowski, Bernd SuresAbstract:Among metal pollutants silver ions are one of the most toxic forms, and have thus been assigned to the highest Toxicity Class. Its Toxicity to a wide range of microorganisms combined with its low Toxicity to humans lead to the development of a wealth of silver-based products in many bactericidal applications accounting to more than 1000 nano-technology-based consumer products. Accordingly, silver is a widely distributed metal in the environment originating from its different forms of application as metal, salt and nanoparticle. A realistic assessment of silver nanoparticle Toxicity in natural waters is, however, problematic and needs to be linked to experimental approaches. Here we apply metatranscriptome sequencing allowing for elucidating reactions of whole communities present in a water sample to stressors. We compared the Toxicity of ionic silver and ligand-free silver nanoparticles by short term exposure on a natural community of aquatic microorganisms. We analyzed the effects of the treatments on metabolic pathways and species composition on the eukaryote metatranscriptome level in order to describe immediate molecular responses of organisms using a community approach. We found significant differences between the samples treated with 5 µg/L AgNO3 compared to the controls, but no significant differences in the samples treated with AgNP compared to the control samples. Statistical analysis yielded 126 genes (KO-IDs) with significant differential expression with a false discovery rate (FDR) <0.05 between the control (KO) and AgNO3 (NO3) groups. A KEGG pathway enrichment analysis showed significant results with a FDR below 0.05 for pathways related to photosynthesis. Our study therefore supports the view that ionic silver rather than silver nanoparticles are responsible for silver Toxicity. Nevertheless, our results highlight the strength of metatranscriptome approaches for assessing metal Toxicity on aquatic communities.
W. Diener - One of the best experts on this subject based on the ideXlab platform.
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Dermal and inhalation acute toxic Class methods: test procedures and biometric evaluations for the Globally Harmonized Classification System
Archives of toxicology, 2003Co-Authors: H. G. Holzhütter, E. Genschow, W. Diener, E. SchledeAbstract:The acute toxic Class (ATC) methods were developed for determining LD50/LC50 estimates of chemical substances with significantly fewer animals than needed when applying conventional LD50/LC50 tests. The ATC methods are sequential stepwise procedures with fixed starting doses/concentrations and a maximum of six animals used per dose/concentration. The numbers of dead/moribund animals determine whether further testing is necessary or whether the test is terminated. In recent years we have developed Classification procedures for the oral, dermal and inhalation routes of administration by using biometric methods. The biometric approach assumes a probit model for the mortality probability of a single animal and assigns the chemical to that Toxicity Class for which the best concordance is achieved between the statistically expected and the observed numbers of dead/moribund animals at the various steps of the test procedure. In previous publications we have demonstrated the validity of the biometric ATC methods on the basis of data obtained for the oral ATC method in two-animal ring studies with 15 participants from six countries. Although the test procedures and biometric evaluations for the dermal and inhalation ATC methods have already been published, there was a need for an adaptation of the Classification schemes to the starting doses/concentrations of the Globally Harmonized Classification System (GHS) recently adopted by the Organization for Economic Co-operation and Development (OECD). Here we present the biometric evaluation of the dermal and inhalation ATC methods for the starting doses/concentrations of the GHS and of some other international Classification systems still in use. We have developed new test procedures and decision rules for the dermal and inhalation ATC methods, which require significantly fewer animals to provide predictions of Toxicity Classes, that are equally good or even better than those achieved by using the conventional LD50/LC50 methods. In order to cope with rather narrow dose/concentration Classes of the GHS we have, as in our previous publications, combined the outcome of all results that can be obtained during testing for the allocation to one of the defined Toxicity Classes of the GHS. Our results strongly recommend the deletion of the dermal LD50 and the inhalation LC50 test as regulatory tests and the adoption of the dermal and inhalation ATC methods as internationally accepted alternatives.
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The biometrie evaluation of the acute-toxic-Class method (oral)
Archives of Toxicology, 1994Co-Authors: W. Diener, L. Siccha, U. Mischke, D. Kayser, E. SchiedeAbstract:The acute toxic Class method (ATC method) is an alternative to the LD_50 test, with the use of substantially fewer animals needed for the Classification of substances. Like the Classical LD_50 test the biometry of the ATC method is based on the probit model. The biometrie calculations of the ATC method were carried out not only for the Classification categories of the European Union but also for the Classification criteria of various countries and organizations, currently in use. It is demonstrated that in comparison with the LD_50 test in general the same Classification is obtained with the ATC method and with the use of substantially fewer animals. Substances with high slopes are likely to be allocated to the predicted Toxicity Class in comparison with substances having low slopes, with both the ATC method and the LD_50 test. Substances are more likely to be allocated into a lower Toxicity Class with the LD_50 test than with the ATC method.
Muller Marc - One of the best experts on this subject based on the ideXlab platform.
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Effects of some controversial food additives on zebrafish embryonic development
2018Co-Authors: Dinh Duy Thanh, Lai Thanh Nguyen, Muller MarcAbstract:Background information: The rising concerns about potential hazardous properties of food additives requires extensive, yet animal-minimized, testing strategies. For that purpose, the zebrafish embryo is the ideal model system which is amenable to high-throughput in vivo assays. Method: In this study, we exposed zebrafish wildtype and transgenic fluorescent embryos to different concentrations of ten controversial food additives: the preservative Sodium benzoate (SB); the flavour enhancer Monosodium glutamate (MSG), the sweetener Aspartame (Asp), and colouring agents Tartrazine (TTZ), Quinoline yellow (QY), Sunset yellow (SY), Azorubine (Az), Ponceau 4R (P4R), Allura red AC (AR), and Brilliant blue (BB). Data was recorded and analysed for morphological and lethal effects, remarkable biological/functional outcomes are further investigated with emphasis on neurodevelopment and neurobehaviour. Results: Effects of each substance on zebrafish embryonic morphology and lethality were determined as well as the corresponding concentration-response relationship. Calculated toxicological indexes (LC50, EC50, and teratogenic index TI) revealed that SB belongs to Cat.3 aquatic Toxicity Class, while QY and BB are highly teratogenic. Remarkably, adverse effects of BB and P4R present a multiphasic dependence on concentration, with BB appearing to weaken the embryonic yolk sac. SB exposure decreased the zebrafish motoneuron differentiation rate, while Az exposure stimulated the hatching rate. Behavioural studies revealed a synergistic effect on locomotive activity due to a mixture of Asp/MSG. Conclusion: Our results demonstrate that the zebrafish embryo is a cost-effective model for high throughput screening of food additives¿ safety and Toxicity. This in vivo model allows systematic detection of biological effects, especially those unexpected by targeted in vitro and in silico models. Also, our data suggest the need to reconsider the safety of food additives SB, BB, and QY as well as other controversial food additives in further studies
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Effects of some controversial food additives on zebrafish embryonic development
'Elsevier BV', 2018Co-Authors: Dinh Duy Thanh, Lai Thanh Nguyen, Van Den Bossche François, Muller MarcAbstract:audience: researcher, professional, student, popularizationBackground information: The rising concerns about potential hazardous properties of food additives requires extensive, yet animal-minimized, testing strategies. For that purpose, the zebrafish embryo is the ideal model system which is amenable to high-throughput in vivo assays. Method: In this study, we exposed zebrafish wildtype and transgenic fluorescent embryos to different concentrations of ten controversial food additives: the preservative Sodium benzoate (SB); the flavour enhancer Monosodium glutamate (MSG), the sweetener Aspartame (Asp), and colouring agents Tartrazine (TTZ), Quinoline yellow (QY), Sunset yellow (SY), Azorubine (Az), Ponceau 4R (P4R), Allura red AC (AR), and Brilliant blue (BB). Data was recorded and analysed for morphological and lethal effects, remarkable biological/functional outcomes are further investigated with emphasis on neurodevelopment and neurobehaviour. Results: Effects of each substance on zebrafish embryonic morphology and lethality were determined as well as the corresponding concentration-response relationship. Calculated toxicological indexes (LC50, EC50, and teratogenic index TI) revealed that SB belongs to Cat.3 aquatic Toxicity Class, while QY and BB are highly teratogenic. Remarkably, adverse effects of BB and P4R present a multiphasic dependence on concentration, with BB appearing to weaken the embryonic yolk sac. SB exposure decreased the zebrafish motoneuron differentiation rate, while Az exposure stimulated the hatching rate. Behavioural studies revealed a synergistic effect on locomotive activity due to a mixture of Asp/MSG. Conclusion: Our results demonstrate that the zebrafish embryo is a cost-effective model for high throughput screening of food additives’ safety and Toxicity. This in vivo model allows systematic detection of biological effects, especially those unexpected by targeted in vitro and in silico models. Also, our data suggest the need to reconsider the safety of food additives SB, BB, and QY as well as other controversial food additives in further studies.Test d'additifs alimentaires et de leurs propriétés biologiques sur cellules et sur les poissons zèbre
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Effects of some controversial food additives on zebrafish embryonic development
2018Co-Authors: Dinh Duy Thanh, Lai Thanh Nguyen, Muller MarcAbstract:audience: researcher, professional, studentBackground information: The rising concerns about potential hazardous properties of food additives requires extensive, yet animal-minimized, testing strategies. For that purpose, the zebrafish embryo is the ideal model system which is amenable to high-throughput in vivo assays. Method: In this study, we exposed zebrafish wildtype and transgenic fluorescent embryos to different concentrations of ten controversial food additives: the preservative Sodium benzoate (SB); the flavour enhancer Monosodium glutamate (MSG), the sweetener Aspartame (Asp), and colouring agents Tartrazine (TTZ), Quinoline yellow (QY), Sunset yellow (SY), Azorubine (Az), Ponceau 4R (P4R), Allura red AC (AR), and Brilliant blue (BB). Data was recorded and analysed for morphological and lethal effects, remarkable biological/functional outcomes are further investigated with emphasis on neurodevelopment and neurobehaviour. Results: Effects of each substance on zebrafish embryonic morphology and lethality were determined as well as the corresponding concentration-response relationship. Calculated toxicological indexes (LC50, EC50, and teratogenic index TI) revealed that SB belongs to Cat.3 aquatic Toxicity Class, while QY and BB are highly teratogenic. Remarkably, adverse effects of BB and P4R present a multiphasic dependence on concentration, with BB appearing to weaken the embryonic yolk sac. SB exposure decreased the zebrafish motoneuron differentiation rate, while Az exposure stimulated the hatching rate. Behavioural studies revealed a synergistic effect on locomotive activity due to a mixture of Asp/MSG. Conclusion: Our results demonstrate that the zebrafish embryo is a cost-effective model for high throughput screening of food additives¿ safety and Toxicity. This in vivo model allows systematic detection of biological effects, especially those unexpected by targeted in vitro and in silico models. Also, our data suggest the need to reconsider the safety of food additives SB, BB, and QY as well as other controversial food additives in further studies.Test d'additifs alimentaires et de leurs propriétés biologiques sur cellules et sur les poissons zèbresProjects CMP8/24 and CMP9.10 between Vietnam and Wallonie-Bruxelle
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Effects of some controversial food additives on zebrafish embryonic development
2014Co-Authors: Dinh Duy Thanh, Lai Thanh Nguyen, Voncken Audrey, Curé Yoann, Pruvot Benoist, Muller MarcAbstract:Background information: There are rising concerns about potential hazardous properties of food additives, forcing legislator to tighten management policy and requiring extensive, yet animal- minimized, testing strategies. The zebrafish embryo is an emerging model system for chemical testing with many advantages that made it amenable to high-throughput assays at the in vivo level. In this study, we applied a panel of tests to evaluate Toxicity, particularly neurobehavioral effects, of seven substances including standard compounds and controversial food additives. Methods: Zebrafish wildtype and transgenic fluorescent embryos were exposed to different concentrations of four food additives: Sodium benzoate (SB), Monosodium glutamate (MSG), Tartrazine (TTZ), and Quinoline yellow (QY). Method validation was carried out using three other substances: Ethanol (EtOH), Dimethyl sulfoxide (DMSO), 3,4-Dichloroaniline (DCA). Morphological and lethal effects were recorded and the data were analysed to determine median lethal concentration (LC50), median effective concentration (EC50), effective concentration 10% (EC10), and teratogenic index (TI) values as well as concentration-response equations. Delayed effects of substances on larval locomotion were inspected using the light/dark challenge. Gene expression analysis was carried out using transgenic fluorescent lines. Results: LC50 values of three standard compounds (EtOH, DMSO, and DCA) reveal a high correlation with previously validated data, proving the reliability of our method. Effects of each substance on zebrafish embryonic morphology and lethality were determined as well as the corresponding concentration-response curves. Calculated toxicological indexes revealed that SB belongs to Cat.3 aquatic Toxicity Class, while QY is the most teratogenic substance. At EC10, all additives exhibited a delayed effect on zebrafish larval locomotion in compound-specific patterns. Observation of transgenic fluorescent embryos and locomotion analysis of hatched larvae reveal that SB could decrease the zebrafish motoneuron differentiation rate, while TTZ exhibited anti-angiogenic effects. Conclusion: Our results demonstrate that our test panel is reliable as a means to assess and categorise chemical Toxicity. Also, our data suggest the need to reconsider the safety of food additives SB, TTZ, and QY as well as other controversial food additives in further studies
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Effects of some controversial food additives on zebrafish embryonic development
2014Co-Authors: Dinh Duy Thanh, Lai Thanh Nguyen, Voncken Audrey, Curé Yoann, Pruvot Benoist, Muller MarcAbstract:audience: researcher, professional, studentBackground information: There are rising concerns about potential hazardous properties of food additives, forcing legislator to tighten management policy and requiring extensive, yet animal- minimized, testing strategies. The zebrafish embryo is an emerging model system for chemical testing with many advantages that made it amenable to high-throughput assays at the in vivo level. In this study, we applied a panel of tests to evaluate Toxicity, particularly neurobehavioral effects, of seven substances including standard compounds and controversial food additives. Methods: Zebrafish wildtype and transgenic fluorescent embryos were exposed to different concentrations of four food additives: Sodium benzoate (SB), Monosodium glutamate (MSG), Tartrazine (TTZ), and Quinoline yellow (QY). Method validation was carried out using three other substances: Ethanol (EtOH), Dimethyl sulfoxide (DMSO), 3,4-Dichloroaniline (DCA). Morphological and lethal effects were recorded and the data were analysed to determine median lethal concentration (LC50), median effective concentration (EC50), effective concentration 10% (EC10), and teratogenic index (TI) values as well as concentration-response equations. Delayed effects of substances on larval locomotion were inspected using the light/dark challenge. Gene expression analysis was carried out using transgenic fluorescent lines. Results: LC50 values of three standard compounds (EtOH, DMSO, and DCA) reveal a high correlation with previously validated data, proving the reliability of our method. Effects of each substance on zebrafish embryonic morphology and lethality were determined as well as the corresponding concentration-response curves. Calculated toxicological indexes revealed that SB belongs to Cat.3 aquatic Toxicity Class, while QY is the most teratogenic substance. At EC10, all additives exhibited a delayed effect on zebrafish larval locomotion in compound-specific patterns. Observation of transgenic fluorescent embryos and locomotion analysis of hatched larvae reveal that SB could decrease the zebrafish motoneuron differentiation rate, while TTZ exhibited anti-angiogenic effects. Conclusion: Our results demonstrate that our test panel is reliable as a means to assess and categorise chemical Toxicity. Also, our data suggest the need to reconsider the safety of food additives SB, TTZ, and QY as well as other controversial food additives in further studies
E. Schiede - One of the best experts on this subject based on the ideXlab platform.
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The biometrie evaluation of the acute-toxic-Class method (oral)
Archives of Toxicology, 1994Co-Authors: W. Diener, L. Siccha, U. Mischke, D. Kayser, E. SchiedeAbstract:The acute toxic Class method (ATC method) is an alternative to the LD_50 test, with the use of substantially fewer animals needed for the Classification of substances. Like the Classical LD_50 test the biometry of the ATC method is based on the probit model. The biometrie calculations of the ATC method were carried out not only for the Classification categories of the European Union but also for the Classification criteria of various countries and organizations, currently in use. It is demonstrated that in comparison with the LD_50 test in general the same Classification is obtained with the ATC method and with the use of substantially fewer animals. Substances with high slopes are likely to be allocated to the predicted Toxicity Class in comparison with substances having low slopes, with both the ATC method and the LD_50 test. Substances are more likely to be allocated into a lower Toxicity Class with the LD_50 test than with the ATC method.
Ridvan Kizilkaya - One of the best experts on this subject based on the ideXlab platform.
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Influence of carbon-containing and mineral sorbents on the Toxicity of soil contaminated with benzo[a]pyrene during phytotesting
Environmental Geochemistry and Health, 2021Co-Authors: Svetlana Sushkova, Tamara Dudnikova, Tatiana Minkina, Andrey Barbashev, Mahmoud Mazarji, Natalia Chernikova, Iliya Lobzenko, Irina Deryabkina, Ridvan KizilkayaAbstract:Benzo[a]pyrene (BaP) is a member of polycyclic aromatic hydrocarbons known for high persistency and Toxicity. Technologies of BaP sorption through solid matrixes have received relatively more attention. The present study was devoted to the phytotesting investigations of two different groups of sorbents, such as carbonaceous, including biochar and granulated activated carbon (GAC), and mineral, including tripoli and diatomite. Evaluation of the BaP removing efficiency was carried out using the phytotesting method with spring barley in Haplic Chernozem contaminated with different levels of contamination (200 and 400 μg kg^−1 BaP). The sorbents’ efficiency for BaP remediation was estimated in the sorbents doses from 0.5 to 2.5% per kg of soil. It was shown that biochar and GAC decreased the soil Toxicity Class to a greater extent than mineral sorbents ones. The effect intensified with an increase in applying sorbents doses. The optimal dose of carbonaceous sorbents into the soil contaminated with 200 µg kg^−1 was 1%, decreasing the BaP content up 57–59% in the soil. Simultaneously, the optimal dose of the mineral sorbents was found to be 1.5%, which decreased the BaP content in the soil up 41–48%. Increasing the BaP contamination level up to 400 µg kg^−1 showed the necessity of a sorbent dose increasing. In these conditions, among all applied sorbents, only 2% GAC could reduce the soil Toxicity Class to the normal level up to 0.91–1.10. It was shown that BaP tended to migrate from the soil to the roots and further into the vegetative part of barley.