Il Young Ahn
Ministry of Food and Drug Safety
Cell cycle checkpointStatisticsH&E stainTest methodPathologyDNA damageEmbryoid bodyBusinessEmbryonic stem cellCellMolecular biologyAndrologyDevelopmental toxicityChemistryProcess managementTUNEL assayIn vitroWilcoxon signed-rank testPhototoxicityIn vivo3T3 cellsSinglet oxygenSperm motilityCutoffDraize testDimethyl sulfoxideTest (assessment)Corneal epitheliumHarmonizationEzrinComet assayLocal lymph node assayMTT assaySuperoxideLymph nodeSodium phosphate bufferPharmaceutical SubstancesToxicityInternational harmonizationCardiac differentiationUltraviolet aSkin sensitizationLimits of agreementAlternative methodsLimited resourcesMathematicsChromatographyPredictive modellingReactive oxygen speciesEpitheliumPotencyReceiver operating characteristicMedicineStainingPhotochemistryBiologyRelevance (information retrieval)PharmacologyReproducibilityReproductive toxicityAnalysis of variance
Publications 7
#1Kyung Yuk Ko (Ministry of Food and Drug Safety)H-Index: 4
#2Mi Hye Hong (Ministry of Food and Drug Safety)H-Index: 1
Last. Jong Kwon Lee (Ministry of Food and Drug Safety)H-Index: 23
view all 9 authors...
Abstract Introduction A variety of in vitro tests to replace the Draize test have been developed; however, there is no available method for assessing the full spectrum of Globally Harmonized System (GHS) categories. Human cornea-like three-dimensional (3D) reconstructed tissue models are the most promising in vitro systems. The objective of this study was to evaluate the ocular toxicity of 11 test substances using the EpiOcular™ model after performing proficiency tests. We further evaluated the ...
2 CitationsSource
#1Hee Young Kang (CBNU: Chungbuk National University)H-Index: 6
#2Young-Kwon Choi (CBNU: Chungbuk National University)H-Index: 3
Last. Eui-Bae Jeung (CBNU: Chungbuk National University)H-Index: 50
view all 12 authors...
Abstract Embryonic stem cell test (EST) evaluates the embryotoxic potential of substances and measures the half inhibition in viability of mouse embryonic stem cells (ESCs), fibroblasts (3T3 cells) and in cardiac differentiation of ESC. In this study, we suggest the developmental toxicity test method (termed EBT) applying area of embryoid bodies (EBs) instead of cardiac differentiation of EST. In the assessment of 21 substances, EB area was logarithmically decreased in dose-dependent manner. Dec...
11 CitationsSource
#1Hye Lyun Jeon (Ministry of Food and Drug Safety)H-Index: 2
#2Jung-Sun Yi (Ministry of Food and Drug Safety)H-Index: 4
Last. Soo Jung Sohn (Ministry of Food and Drug Safety)H-Index: 4
view all 14 authors...
Although alternative test methods based on the 3Rs (Replacement, Reduction, Refinement) are being developed to replace animal testing in reproductive and developmental toxicology, they are still in an early stage. Consequently, we aimed to develop alternative test methods in male animals using mouse spermatogonial stem cells (mSSCs). Here, we modified the OECD TG 489 and optimized the in vitro comet assay in our previous study. This study aimed to verify the validity of in vitro tests involving ...
8 CitationsSource
Abstract Recently UN GHS has introduced the sub-categorization of skin sensitizers for which ECt (concentration estimated to induce stimulation index above threshold) of the murine local lymph node assay (LLNA) is used as criteria. Non-radioisotopic variants of LLNA, LLNA: DA, LLNA: BrdU-ELISA, LNCC and LLNA: BrdU-FCM were developed yet their utilities for potency sub-categorization are not established. Here we assessed the agreement of LLNA variants with LLNA or human data in potency sub-catego...
4 CitationsSource
#1Yong Sun Lee (Ministry of Food and Drug Safety)H-Index: 2
#2Jung-Sun Yi (Ministry of Food and Drug Safety)H-Index: 4
Last. Jong Kwon Lee (Ministry of Food and Drug Safety)H-Index: 23
view all 10 authors...
With ultraviolet and visible light exposure, some pharmaceutical substances applied systemically or topically may cause phototoxic skin irritation. The major factor in phototoxicity is the generation of reactive oxygen species (ROS) such as singlet oxygen and superoxide anion that cause oxidative damage to DNA, lipids and proteins. Thus, measuring the generation of ROS can predict the phototoxic potential of a given substance indirectly. For this reason, a standard ROS assay (ROS assay) was deve...
13 CitationsSource
#1Da-eun Kim (Ewha Womans University)H-Index: 4
#2Hyeri Yang (Ewha Womans University)H-Index: 5
Last. SeungJin Bae (Ewha Womans University)H-Index: 13
view all 18 authors...
Abstract In order for a novel test method to be applied for regulatory purposes, its reliability and relevance, i.e., reproducibility and predictive capacity, must be demonstrated. Here, we examine the predictive capacity of a novel non-radioisotopic local lymph node assay, LLNA:BrdU–FCM (5-bromo-2′-deoxyuridine-flow cytometry), with a cutoff approach and inferential statistics as a prediction model. 22 reference substances in OECD TG429 were tested with a concurrent positive control, hexylcinna...
6 CitationsSource
The development and validation of scientific alternatives to animal testing is important not only from an ethical perspective (implementation of 3Rs), but also to improve safety assessment decision making with the use of mechanistic information of higher relevance to humans. To be effective in these efforts, it is however imperative that validation centres, industry, regulatory bodies, academia and other interested parties ensure a strong international cooperation, cross-sector collaboration and...
9 CitationsSource