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Aynur O Aptula - One of the best experts on this subject based on the ideXlab platform.
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chemical applicability domain of the local lymph node assay llna for Skin sensitisation potency part 2 the biological variability of the murine local lymph node assay llna for Skin sensitisation
Regulatory Toxicology and Pharmacology, 2016Co-Authors: David W Roberts, A M Api, Aynur O AptulaAbstract:The Local Lymph Node Assay (LLNA) is the most common in vivo regulatory toxicology test for Skin sensitisation, quantifying potency as the EC3, the concentration of chemical giving a threefold increase in thymidine uptake in the local lymph node. Existing LLNA data can, along with clinical data, provide useful comparator information on the potency of sensitisers. Understanding of the biological variability of data from LLNA studies is important for those developing non-animal based risk assessment approaches for Skin Allergy. Here an existing set of 94 EC3 values for 12 chemicals, all tested at least three times in the same vehicle have been analysed by calculating standard deviations (SD) for logEC3 values. The SDs range from 0.08 to 0.22. The overall SD for the 94 logEC3 values is 0.147. Thus the 95% confidence limits (2xSD) for LLNA EC3 values are within a factor of 2, comparable to those for physico-chemical measurements such as partition coefficients and solubility. The residual SDs of Quantitative Mechanistic Models (QMMs) based on physical organic chemistry parameters are similar to the overall SD of the LLNA, indicating that QMMs of this type are unlikely to be bettered for predictive accuracy.
David W Roberts - One of the best experts on this subject based on the ideXlab platform.
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chemical applicability domain of the local lymph node assay llna for Skin sensitisation potency part 2 the biological variability of the murine local lymph node assay llna for Skin sensitisation
Regulatory Toxicology and Pharmacology, 2016Co-Authors: David W Roberts, A M Api, Aynur O AptulaAbstract:The Local Lymph Node Assay (LLNA) is the most common in vivo regulatory toxicology test for Skin sensitisation, quantifying potency as the EC3, the concentration of chemical giving a threefold increase in thymidine uptake in the local lymph node. Existing LLNA data can, along with clinical data, provide useful comparator information on the potency of sensitisers. Understanding of the biological variability of data from LLNA studies is important for those developing non-animal based risk assessment approaches for Skin Allergy. Here an existing set of 94 EC3 values for 12 chemicals, all tested at least three times in the same vehicle have been analysed by calculating standard deviations (SD) for logEC3 values. The SDs range from 0.08 to 0.22. The overall SD for the 94 logEC3 values is 0.147. Thus the 95% confidence limits (2xSD) for LLNA EC3 values are within a factor of 2, comparable to those for physico-chemical measurements such as partition coefficients and solubility. The residual SDs of Quantitative Mechanistic Models (QMMs) based on physical organic chemistry parameters are similar to the overall SD of the LLNA, indicating that QMMs of this type are unlikely to be bettered for predictive accuracy.
A M Api - One of the best experts on this subject based on the ideXlab platform.
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chemical applicability domain of the local lymph node assay llna for Skin sensitisation potency part 2 the biological variability of the murine local lymph node assay llna for Skin sensitisation
Regulatory Toxicology and Pharmacology, 2016Co-Authors: David W Roberts, A M Api, Aynur O AptulaAbstract:The Local Lymph Node Assay (LLNA) is the most common in vivo regulatory toxicology test for Skin sensitisation, quantifying potency as the EC3, the concentration of chemical giving a threefold increase in thymidine uptake in the local lymph node. Existing LLNA data can, along with clinical data, provide useful comparator information on the potency of sensitisers. Understanding of the biological variability of data from LLNA studies is important for those developing non-animal based risk assessment approaches for Skin Allergy. Here an existing set of 94 EC3 values for 12 chemicals, all tested at least three times in the same vehicle have been analysed by calculating standard deviations (SD) for logEC3 values. The SDs range from 0.08 to 0.22. The overall SD for the 94 logEC3 values is 0.147. Thus the 95% confidence limits (2xSD) for LLNA EC3 values are within a factor of 2, comparable to those for physico-chemical measurements such as partition coefficients and solubility. The residual SDs of Quantitative Mechanistic Models (QMMs) based on physical organic chemistry parameters are similar to the overall SD of the LLNA, indicating that QMMs of this type are unlikely to be bettered for predictive accuracy.
J F Silvestresalvador - One of the best experts on this subject based on the ideXlab platform.
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the spanish standard patch test series 2016 update by the spanish contact dermatitis and Skin Allergy research group geidac
Actas Dermo-Sifiliográficas, 2016Co-Authors: M Hervellagarces, J Garciagavin, J F SilvestresalvadorAbstract:The Spanish standard patch test series, as recommended by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC), has been updated for 2016. The new series replaces the 2012 version and contains the minimum set of allergens recommended for routine investigation of contact Allergy in Spain from 2016 onwards. Four haptens -clioquinol, thimerosal, mercury, and primin- have been eliminated owing to a low frequency of relevant allergic reactions, while 3 new allergens -methylisothiazolinone, diazolidinyl urea, and imidazolidinyl urea- have been added. GEIDAC has also modified the recommended aqueous solution concentrations for the 2 classic, major haptens methylchloroisothiazolinone and methylisothiazolinone, which are now to be tested at 200ppm in aqueous solution, and formaldehyde, which is now to be tested in a 2% aqueous solution. Updating the Spanish standard series is one of the functions of GEIDAC, which is responsible for ensuring that the standard series is suited to the country's epidemiological profile and pattern of contact sensitization.
P Vermeire - One of the best experts on this subject based on the ideXlab platform.
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higher asthma occurrence in an urban than a suburban area role of house dust mite Skin Allergy
European Respiratory Journal, 1997Co-Authors: M H Wieringa, Joost Weyler, F J Van Bastelaer, V J Nelen, M Van Sprundel, P VermeireAbstract:Understanding of geographical differences in asthma prevalence may be helpful in explaining recent increases in the occurrence of asthma. We wondered whether differences in allergic sensitization or other factors could explain differences in reported occurrence of asthma between an urban centre and a neighbouring suburban area. From the European Community Respiratory Health Survey (ECRHS) questionnaire, responses on asthma symptoms and risk factors and results of 11 Skin Allergy tests were available from 656 young adults living in urban or south suburban Antwerp, Belgium. Answers to five asthma questions were selected as dependent variables, and eight personal or environmental risk factors, as well as house dust mite (HDM) Allergy, as independent variables. The effect of each independent variable on the association of asthma variables with area was assessed. Prior asthma diagnosis, present asthma symptoms, the selected risk factors and HDM Allergy were all more frequently recorded in urban Antwerp. Difference in HDM Allergy accounted for most of the difference in prior (mostly childhood) asthma diagnosis, since correction for it decreased the odds ratio from 2.10 to 1.65. On the contrary, the regional differences in recent asthma symptoms were not explained by HDM Allergy differences nor by any other factor under study. This urban-suburban comparison indicated that house dust mite Allergy is a major determinant of prior (childhood) asthma, whereas factors contributing to higher urban prevalence of present asthma symptoms could not be identified. Furthermore, our results indicate that it may be inappropriate to combine data from neighbouring areas, when their similarity has not been verified.