The Experts below are selected from a list of 918 Experts worldwide ranked by ideXlab platform

Naohiro Nishiyama - One of the best experts on this subject based on the ideXlab platform.

  • prediction of skin sensitization potency of chemicals by human cell line activation test h clat and an attempt at classifying skin sensitization potency
    Toxicology in Vitro, 2012
    Co-Authors: Yuko Nukada, Hitoshi Sakaguchi, Takao Ashikaga, Masaaki Miyazawa, Morihiko Hirota, Hitoshi Sasa, Naohiro Nishiyama
    Abstract:

    The human Cell Line Activation Test (h-CLAT), an in vitro skin sensitization test, is based on the augmentation of CD86 and CD54 expression in THP-1 cells following exposure to chemicals. The h-CLAT was found to be capable of determining the hazard of skin sensitization. In contrast, the local lymph node assay (LLNA), widely used as a stand-alone method in Europe and US, identifies the same hazard, but also classifies the potency by using the estimated concentration of SI=3 (EC3). In this study, several values calculated from the h-CLAT data were evaluated for its correlation to the LLNA EC3 determination. A statistically significant correlation was observed between h-CLAT concentration providing a cell viability of 75% (CV75), h-CLAT estimated concentration of RFI=150 for CD86 (EC150), and for CD54 (EC200) with LLNA's EC3. From EC150 and EC200, a minimum induction threshold (MIT) was determined as the smaller of either EC150 or EC200. MIT showed a correlation with EC3 (R=0.638). Also, MIT had an approximate 80% accuracy for sub-categories of the Globally Harmonized System (GHS) when a tentative threshold of 13 μg/mL was used. From these data, the h-CLAT values may be one of the useful tools to predict the allergic potency of chemicals.

  • two stage bottom up tiered approach combining several alternatives for identification of eye irritation potential of chemicals including insoluble or volatile substances
    Toxicology in Vitro, 2012
    Co-Authors: Kazuhiko Hayashi, Hitoshi Sakaguchi, Taeko Mori, Yutaka Takahashi, Takumi Hayashi, Kenichi Ooshima, Tomoko Komano, Akihiko Takatsu, Naohiro Nishiyama
    Abstract:

    Abstract For the assessment of eye irritation, one alternative test may not completely replace the rabbit Draize test. In the present study, we examined the predictive potential of a tiered approach analyzing the results from several alternatives (i.e., the Short Time Exposure (STE) test, the EpiOcular assay, the Hen’s Egg Test-Chorioallantoic Membrane (HET-CAM) assay and the Bovine Corneal Opacity and Permeability (BCOP) assay) for assessing Globally Harmonized System (GHS) eye irritation categories. Fifty-six chemicals including alcohols, surfactants, and esters were selected with a balanced GHS category and a wide range of chemical classes. From a standpoint of both assessable sample numbers and predictive accuracy, the more favorable tiered approach was considered to be the two-stage bottom-up tiered approach combining the STE test, the EpiOcular assay followed by the BCOP assay (accuracy 69.6%, under prediction rate 8.9%). Moreover, a more favorable predictive capacity (accuracy 71.4%, under prediction rate 3.6%) was obtained when high volatile alcohols/esters with vapor pressures >6 kilopascal (kPa) at 25 °C were evaluated with EpiOcular assay instead of the STE test. From these results, the two-stage bottom-up tiered approach combining the STE test, the EpiOcular assay followed by the BCOP assay might be a promising method for the classification of GHS eye irritation category (Not classified (NC), Category 2 (Cat. 2), and Category 1 (Cat. 1)) for a wide range of test chemicals regardless of solubility.

  • A tiered approach combining the short time exposure (STE) test and the bovine corneal opacity and permeability (BCOP) assay for predicting eye irritation potential of chemicals
    Journal of Toxicological Sciences, 2012
    Co-Authors: Kazuhiko Hayashi, Mirei Koike, Hitoshi Sakaguchi, Taeko Mori, Yutaka Takahashi, Naohiro Nishiyama
    Abstract:

    For the evaluation of eye irritation, one in vitro alternative test may not completely replace the Draize test. Therefore, a tiered approach combining several in vitro assays, including cytotoxicity assays, is proposed in order to estimate the eye irritation potential of a wide range of chemical classes. The Short Time Exposure (STE) test, a relatively newer alternative eye irritation test, involves exposing Statens seruminstitut rabbit cornea (SIRC) cells for 5 min to two concentrations (5% and 0.05%) of test material. In the present study, we examined the predictive capacity of a tiered approach analyzing the results from the STE test and then the results of the bovine corneal opacity and permeability (BCOP) assay for assessing Globally Harmonized System (GHS) eye irritation rankings of various chemicals. The accuracy of predicting the GHS rankings was slightly improved when the tiered approach combination of STE test and BCOP assay was used compared to when the STE test irritation rank classification was used alone. Moreover, the under prediction rate was substantially improved when this tiered approach was used. From these results, the tiered approach of combining the data analysis of the STE test and BCOP assay might be a promising alternative eye irritation test strategy.

  • The Short Time Exposure (STE) test for predicting eye irritation potential: intra-laboratory reproducibility and correspondence to Globally Harmonized System (GHS) and EU eye irritation classification for 109 chemicals.
    Toxicology in Vitro, 2011
    Co-Authors: Yutaka Takahashi, Mirei Koike, Hitoshi Sakaguchi, Kazuhiko Hayashi, Naohiro Nishiyama
    Abstract:

    Abstract Short Time Exposure (STE) test is an easy in vitro eye irritation test that assesses cytotoxicity in SIRC cells (rabbit corneal cell line) following a 5 min dose treatment. To assess intra-laboratory reproducibility, medium control, three vehicles (saline, saline containing 5% (w/w) dimethyl sulfoxide, and mineral oil) and three standard chemicals (sodium lauryl sulfate, calcium thioglycolate, and Tween 80) were evaluated. Assessments were repeated 30 times for vehicles and 18 times for standard chemicals; resulting in almost the same cell viability and a low coefficient of variation value. In addition, the STE eye irritation rankings of three standard chemicals, as calculated on the cell viabilities in 5% and 0.05% solutions were in agreement in all tests. Based on these results, high intra-laboratory reproducibility was confirmed. In addition, the irritation category (irritant and non-irritant) was evaluated for 109 chemicals with STE test, Globally Harmonized System (GHS) classification, and European Union (EU) classification. The results of the evaluation found the STE classification to have an accuracy with GHS classification of 87% and with EU classification of 83%, which confirmed the excellent correspondence. The correspondence of STE rankings (1, 2, and 3) based on the prediction model by STE test with the eye irritation rankings by GHS (non-irritant, categories 2 and 1) and EU (non-irritant, R36, and R41) was 76% and 71%, respectively. Based on the above results, STE test was considered to be a promising alternative method for assessing eye irritation that has high intra-laboratory reproducibility as well as an excellent predictability of eye irritation.

Hitoshi Sakaguchi - One of the best experts on this subject based on the ideXlab platform.

  • second phase validation study of short time exposure test for assessment of eye irritation potency of chemicals
    Toxicology in Vitro, 2013
    Co-Authors: Hajime Kojima, Hitoshi Sakaguchi, Kazuhiko Hayashi, Takumi Hayashi, Hirofumi Kuwahara, Takashi Omori, Takashi Sozu, Takuya Otoizumi, Mayumi Sakaguchi, Akemi Toyoda
    Abstract:

    Abstract A Short Time Exposure (STE) test is a cytotoxicity test that uses SIRC cells (rabbit corneal cell line) to assess eye irritation potency following a 5-min chemical exposure. This second-phase validation study assessed the predictive capacity of the STE test using 40 coded test substances at three laboratories. A Validation Management Team (VMT) then evaluated the predictivity of the STE test for United Nation (UN) Globally Harmonized System (GHS) categories using 63 test substances including the results of the first-phase validation study. The STE test can assess not only the severe or corrosive ocular irritants (corresponding to the UN GHS Category 1) but also non-irritant (corresponding to UN GHS Non Category) from other toxicity classes, especially for limited types of test substances. The predictivity by STE test, however, was insufficient for identification of UN GHS categories (Category 1, Category 2, or Non Category). These results suggest that the STE test can be recommended as an initial step in a top-down approach to identification of severe irritants and test substances that require classification for eye irritation (UN GHS Category 1) as well as an initial step in a bottom-up approach to identification of test substances that do not require classification for eye irritation (UN GHS Non Category) from other toxicity classes, especially for limited types of test substances. On the other hand, the STE test is not considered adequate for the identification of mild or moderate irritants (i.e., UN GHS Categories 2A and 2B) and severe irritants (UN GHS Category 1).

  • prediction of skin sensitization potency of chemicals by human cell line activation test h clat and an attempt at classifying skin sensitization potency
    Toxicology in Vitro, 2012
    Co-Authors: Yuko Nukada, Hitoshi Sakaguchi, Takao Ashikaga, Masaaki Miyazawa, Morihiko Hirota, Hitoshi Sasa, Naohiro Nishiyama
    Abstract:

    The human Cell Line Activation Test (h-CLAT), an in vitro skin sensitization test, is based on the augmentation of CD86 and CD54 expression in THP-1 cells following exposure to chemicals. The h-CLAT was found to be capable of determining the hazard of skin sensitization. In contrast, the local lymph node assay (LLNA), widely used as a stand-alone method in Europe and US, identifies the same hazard, but also classifies the potency by using the estimated concentration of SI=3 (EC3). In this study, several values calculated from the h-CLAT data were evaluated for its correlation to the LLNA EC3 determination. A statistically significant correlation was observed between h-CLAT concentration providing a cell viability of 75% (CV75), h-CLAT estimated concentration of RFI=150 for CD86 (EC150), and for CD54 (EC200) with LLNA's EC3. From EC150 and EC200, a minimum induction threshold (MIT) was determined as the smaller of either EC150 or EC200. MIT showed a correlation with EC3 (R=0.638). Also, MIT had an approximate 80% accuracy for sub-categories of the Globally Harmonized System (GHS) when a tentative threshold of 13 μg/mL was used. From these data, the h-CLAT values may be one of the useful tools to predict the allergic potency of chemicals.

  • two stage bottom up tiered approach combining several alternatives for identification of eye irritation potential of chemicals including insoluble or volatile substances
    Toxicology in Vitro, 2012
    Co-Authors: Kazuhiko Hayashi, Hitoshi Sakaguchi, Taeko Mori, Yutaka Takahashi, Takumi Hayashi, Kenichi Ooshima, Tomoko Komano, Akihiko Takatsu, Naohiro Nishiyama
    Abstract:

    Abstract For the assessment of eye irritation, one alternative test may not completely replace the rabbit Draize test. In the present study, we examined the predictive potential of a tiered approach analyzing the results from several alternatives (i.e., the Short Time Exposure (STE) test, the EpiOcular assay, the Hen’s Egg Test-Chorioallantoic Membrane (HET-CAM) assay and the Bovine Corneal Opacity and Permeability (BCOP) assay) for assessing Globally Harmonized System (GHS) eye irritation categories. Fifty-six chemicals including alcohols, surfactants, and esters were selected with a balanced GHS category and a wide range of chemical classes. From a standpoint of both assessable sample numbers and predictive accuracy, the more favorable tiered approach was considered to be the two-stage bottom-up tiered approach combining the STE test, the EpiOcular assay followed by the BCOP assay (accuracy 69.6%, under prediction rate 8.9%). Moreover, a more favorable predictive capacity (accuracy 71.4%, under prediction rate 3.6%) was obtained when high volatile alcohols/esters with vapor pressures >6 kilopascal (kPa) at 25 °C were evaluated with EpiOcular assay instead of the STE test. From these results, the two-stage bottom-up tiered approach combining the STE test, the EpiOcular assay followed by the BCOP assay might be a promising method for the classification of GHS eye irritation category (Not classified (NC), Category 2 (Cat. 2), and Category 1 (Cat. 1)) for a wide range of test chemicals regardless of solubility.

  • A tiered approach combining the short time exposure (STE) test and the bovine corneal opacity and permeability (BCOP) assay for predicting eye irritation potential of chemicals
    Journal of Toxicological Sciences, 2012
    Co-Authors: Kazuhiko Hayashi, Mirei Koike, Hitoshi Sakaguchi, Taeko Mori, Yutaka Takahashi, Naohiro Nishiyama
    Abstract:

    For the evaluation of eye irritation, one in vitro alternative test may not completely replace the Draize test. Therefore, a tiered approach combining several in vitro assays, including cytotoxicity assays, is proposed in order to estimate the eye irritation potential of a wide range of chemical classes. The Short Time Exposure (STE) test, a relatively newer alternative eye irritation test, involves exposing Statens seruminstitut rabbit cornea (SIRC) cells for 5 min to two concentrations (5% and 0.05%) of test material. In the present study, we examined the predictive capacity of a tiered approach analyzing the results from the STE test and then the results of the bovine corneal opacity and permeability (BCOP) assay for assessing Globally Harmonized System (GHS) eye irritation rankings of various chemicals. The accuracy of predicting the GHS rankings was slightly improved when the tiered approach combination of STE test and BCOP assay was used compared to when the STE test irritation rank classification was used alone. Moreover, the under prediction rate was substantially improved when this tiered approach was used. From these results, the tiered approach of combining the data analysis of the STE test and BCOP assay might be a promising alternative eye irritation test strategy.

  • validation study of the short time exposure ste test to assess the eye irritation potential of chemicals
    Toxicology in Vitro, 2011
    Co-Authors: Hitoshi Sakaguchi, Yutaka Takahashi, Tsuneaki Nakamura, Hirofumi Kuwahara, Takashi Omori, Takashi Sozu, Yumi Takagi, Kouko Tanigawa, Miki Nakanishi, Takashi Morimoto
    Abstract:

    Abstract Short Time Exposure (STE) test is a cytotoxicity test in SIRC cells (rabbit corneal cell line) that assesses eye irritation potential following a 5-min chemical exposure. This validation study assessed transferability, intra- and inter-laboratory reproducibility, and predictive capacity of STE test in five laboratories (supported by Japanese Society for Alternatives to Animal Experiments). Sodium lauryl sulfate, calcium thioglycolate, and Tween 80 were evaluated, in triplicate, using 5%, 0.5%, and 0.05% concentrations in physiological saline, to confirm transferability. Good transferability was noted when similar mean relative viabilities and rank classifications were obtained in all five laboratories and were comparable to data from test method developing laboratory. Good intra- and inter-laboratory reproducibility was obtained with four assay controls (three solvents and one positive control), and four assay controls and 25 chemicals, respectively. STE irritation category based on relative viability of a 5% solution of 25 blinded test chemicals showed good correlation with Globally Harmonized System (GHS) categories (NI; I: Cat. 1 and 2). The STE prediction model, using relative viability of the 5% and 0.05% solutions, provided an irritation rank (1, 2, or 3) that had a good correlation (above 80%), or predictive capacity, with GHS irritation ranks in all laboratories. Based on these findings, the STE test is a promising alternative eye irritation test that could be easily standardized.

Kazuhiko Hayashi - One of the best experts on this subject based on the ideXlab platform.

  • second phase validation study of short time exposure test for assessment of eye irritation potency of chemicals
    Toxicology in Vitro, 2013
    Co-Authors: Hajime Kojima, Hitoshi Sakaguchi, Kazuhiko Hayashi, Takumi Hayashi, Hirofumi Kuwahara, Takashi Omori, Takashi Sozu, Takuya Otoizumi, Mayumi Sakaguchi, Akemi Toyoda
    Abstract:

    Abstract A Short Time Exposure (STE) test is a cytotoxicity test that uses SIRC cells (rabbit corneal cell line) to assess eye irritation potency following a 5-min chemical exposure. This second-phase validation study assessed the predictive capacity of the STE test using 40 coded test substances at three laboratories. A Validation Management Team (VMT) then evaluated the predictivity of the STE test for United Nation (UN) Globally Harmonized System (GHS) categories using 63 test substances including the results of the first-phase validation study. The STE test can assess not only the severe or corrosive ocular irritants (corresponding to the UN GHS Category 1) but also non-irritant (corresponding to UN GHS Non Category) from other toxicity classes, especially for limited types of test substances. The predictivity by STE test, however, was insufficient for identification of UN GHS categories (Category 1, Category 2, or Non Category). These results suggest that the STE test can be recommended as an initial step in a top-down approach to identification of severe irritants and test substances that require classification for eye irritation (UN GHS Category 1) as well as an initial step in a bottom-up approach to identification of test substances that do not require classification for eye irritation (UN GHS Non Category) from other toxicity classes, especially for limited types of test substances. On the other hand, the STE test is not considered adequate for the identification of mild or moderate irritants (i.e., UN GHS Categories 2A and 2B) and severe irritants (UN GHS Category 1).

  • two stage bottom up tiered approach combining several alternatives for identification of eye irritation potential of chemicals including insoluble or volatile substances
    Toxicology in Vitro, 2012
    Co-Authors: Kazuhiko Hayashi, Hitoshi Sakaguchi, Taeko Mori, Yutaka Takahashi, Takumi Hayashi, Kenichi Ooshima, Tomoko Komano, Akihiko Takatsu, Naohiro Nishiyama
    Abstract:

    Abstract For the assessment of eye irritation, one alternative test may not completely replace the rabbit Draize test. In the present study, we examined the predictive potential of a tiered approach analyzing the results from several alternatives (i.e., the Short Time Exposure (STE) test, the EpiOcular assay, the Hen’s Egg Test-Chorioallantoic Membrane (HET-CAM) assay and the Bovine Corneal Opacity and Permeability (BCOP) assay) for assessing Globally Harmonized System (GHS) eye irritation categories. Fifty-six chemicals including alcohols, surfactants, and esters were selected with a balanced GHS category and a wide range of chemical classes. From a standpoint of both assessable sample numbers and predictive accuracy, the more favorable tiered approach was considered to be the two-stage bottom-up tiered approach combining the STE test, the EpiOcular assay followed by the BCOP assay (accuracy 69.6%, under prediction rate 8.9%). Moreover, a more favorable predictive capacity (accuracy 71.4%, under prediction rate 3.6%) was obtained when high volatile alcohols/esters with vapor pressures >6 kilopascal (kPa) at 25 °C were evaluated with EpiOcular assay instead of the STE test. From these results, the two-stage bottom-up tiered approach combining the STE test, the EpiOcular assay followed by the BCOP assay might be a promising method for the classification of GHS eye irritation category (Not classified (NC), Category 2 (Cat. 2), and Category 1 (Cat. 1)) for a wide range of test chemicals regardless of solubility.

  • A tiered approach combining the short time exposure (STE) test and the bovine corneal opacity and permeability (BCOP) assay for predicting eye irritation potential of chemicals
    Journal of Toxicological Sciences, 2012
    Co-Authors: Kazuhiko Hayashi, Mirei Koike, Hitoshi Sakaguchi, Taeko Mori, Yutaka Takahashi, Naohiro Nishiyama
    Abstract:

    For the evaluation of eye irritation, one in vitro alternative test may not completely replace the Draize test. Therefore, a tiered approach combining several in vitro assays, including cytotoxicity assays, is proposed in order to estimate the eye irritation potential of a wide range of chemical classes. The Short Time Exposure (STE) test, a relatively newer alternative eye irritation test, involves exposing Statens seruminstitut rabbit cornea (SIRC) cells for 5 min to two concentrations (5% and 0.05%) of test material. In the present study, we examined the predictive capacity of a tiered approach analyzing the results from the STE test and then the results of the bovine corneal opacity and permeability (BCOP) assay for assessing Globally Harmonized System (GHS) eye irritation rankings of various chemicals. The accuracy of predicting the GHS rankings was slightly improved when the tiered approach combination of STE test and BCOP assay was used compared to when the STE test irritation rank classification was used alone. Moreover, the under prediction rate was substantially improved when this tiered approach was used. From these results, the tiered approach of combining the data analysis of the STE test and BCOP assay might be a promising alternative eye irritation test strategy.

  • The Short Time Exposure (STE) test for predicting eye irritation potential: intra-laboratory reproducibility and correspondence to Globally Harmonized System (GHS) and EU eye irritation classification for 109 chemicals.
    Toxicology in Vitro, 2011
    Co-Authors: Yutaka Takahashi, Mirei Koike, Hitoshi Sakaguchi, Kazuhiko Hayashi, Naohiro Nishiyama
    Abstract:

    Abstract Short Time Exposure (STE) test is an easy in vitro eye irritation test that assesses cytotoxicity in SIRC cells (rabbit corneal cell line) following a 5 min dose treatment. To assess intra-laboratory reproducibility, medium control, three vehicles (saline, saline containing 5% (w/w) dimethyl sulfoxide, and mineral oil) and three standard chemicals (sodium lauryl sulfate, calcium thioglycolate, and Tween 80) were evaluated. Assessments were repeated 30 times for vehicles and 18 times for standard chemicals; resulting in almost the same cell viability and a low coefficient of variation value. In addition, the STE eye irritation rankings of three standard chemicals, as calculated on the cell viabilities in 5% and 0.05% solutions were in agreement in all tests. Based on these results, high intra-laboratory reproducibility was confirmed. In addition, the irritation category (irritant and non-irritant) was evaluated for 109 chemicals with STE test, Globally Harmonized System (GHS) classification, and European Union (EU) classification. The results of the evaluation found the STE classification to have an accuracy with GHS classification of 87% and with EU classification of 83%, which confirmed the excellent correspondence. The correspondence of STE rankings (1, 2, and 3) based on the prediction model by STE test with the eye irritation rankings by GHS (non-irritant, categories 2 and 1) and EU (non-irritant, R36, and R41) was 76% and 71%, respectively. Based on the above results, STE test was considered to be a promising alternative method for assessing eye irritation that has high intra-laboratory reproducibility as well as an excellent predictability of eye irritation.

  • inter laboratory study of short time exposure ste test for predicting eye irritation potential of chemicals and correspondence to Globally Harmonized System ghs classification
    Journal of Toxicological Sciences, 2009
    Co-Authors: Yutaka Takahashi, Mirei Koike, Hitoshi Sakaguchi, Kazuhiko Hayashi, Takumi Hayashi, Shinichi Watanabe, Noriko Aisawa, Shinya Ebata, Tsuneaki Nakamura, Hirofumi Kuwahara
    Abstract:

    Short time exposure (STE) test using rabbit corneal cell line (SIRC) cells was developed as an alternative eye irritation test. STE test uses relative viability as the endpoint after cells are exposed to the test material at constant concentrations for 5 min. In this inter-laboratory study with 3 laboratories, 44 chemicals with a wide range of classes were evaluated for the transferability, between-lab reproducibility and predictive capacity of the STE test as an alternative eye irritation test. Globally Harmonized System (GHS) classification based on Draize eye irritation test data was used as the comparative in vivo data. Transferability was assessed using standard chemicals (sodium lauryl sulfate, calcium thioglycolate, and Tween 80) and the coefficient variations (CVs) of relative viabilities between 3 labs were less than 0.13. The irritation category (Irritant or Non irritant) at each test concentration (5% and 0.05%) in STE test was the same in 3 laboratories for all 44 tested chemicals. The predictive capacity irritation category classification between STE test and GHS were compared, and a good correlation was confirmed (accuracy was 90.9% at all laboratories). In addition, the STE rankings of 1, 2, and 3 classified by the prediction model (PM) based on the relative viability at two concentrations (5% and 0.05%) were highly correlated with the GHS ranks of non-irritant, category 1, and category 2, respectively (accuracy was 75.0% at all laboratories). These results suggest that the STE test possessed easy transferability, reproducibility, good predictive performance.

Yutaka Takahashi - One of the best experts on this subject based on the ideXlab platform.

  • two stage bottom up tiered approach combining several alternatives for identification of eye irritation potential of chemicals including insoluble or volatile substances
    Toxicology in Vitro, 2012
    Co-Authors: Kazuhiko Hayashi, Hitoshi Sakaguchi, Taeko Mori, Yutaka Takahashi, Takumi Hayashi, Kenichi Ooshima, Tomoko Komano, Akihiko Takatsu, Naohiro Nishiyama
    Abstract:

    Abstract For the assessment of eye irritation, one alternative test may not completely replace the rabbit Draize test. In the present study, we examined the predictive potential of a tiered approach analyzing the results from several alternatives (i.e., the Short Time Exposure (STE) test, the EpiOcular assay, the Hen’s Egg Test-Chorioallantoic Membrane (HET-CAM) assay and the Bovine Corneal Opacity and Permeability (BCOP) assay) for assessing Globally Harmonized System (GHS) eye irritation categories. Fifty-six chemicals including alcohols, surfactants, and esters were selected with a balanced GHS category and a wide range of chemical classes. From a standpoint of both assessable sample numbers and predictive accuracy, the more favorable tiered approach was considered to be the two-stage bottom-up tiered approach combining the STE test, the EpiOcular assay followed by the BCOP assay (accuracy 69.6%, under prediction rate 8.9%). Moreover, a more favorable predictive capacity (accuracy 71.4%, under prediction rate 3.6%) was obtained when high volatile alcohols/esters with vapor pressures >6 kilopascal (kPa) at 25 °C were evaluated with EpiOcular assay instead of the STE test. From these results, the two-stage bottom-up tiered approach combining the STE test, the EpiOcular assay followed by the BCOP assay might be a promising method for the classification of GHS eye irritation category (Not classified (NC), Category 2 (Cat. 2), and Category 1 (Cat. 1)) for a wide range of test chemicals regardless of solubility.

  • A tiered approach combining the short time exposure (STE) test and the bovine corneal opacity and permeability (BCOP) assay for predicting eye irritation potential of chemicals
    Journal of Toxicological Sciences, 2012
    Co-Authors: Kazuhiko Hayashi, Mirei Koike, Hitoshi Sakaguchi, Taeko Mori, Yutaka Takahashi, Naohiro Nishiyama
    Abstract:

    For the evaluation of eye irritation, one in vitro alternative test may not completely replace the Draize test. Therefore, a tiered approach combining several in vitro assays, including cytotoxicity assays, is proposed in order to estimate the eye irritation potential of a wide range of chemical classes. The Short Time Exposure (STE) test, a relatively newer alternative eye irritation test, involves exposing Statens seruminstitut rabbit cornea (SIRC) cells for 5 min to two concentrations (5% and 0.05%) of test material. In the present study, we examined the predictive capacity of a tiered approach analyzing the results from the STE test and then the results of the bovine corneal opacity and permeability (BCOP) assay for assessing Globally Harmonized System (GHS) eye irritation rankings of various chemicals. The accuracy of predicting the GHS rankings was slightly improved when the tiered approach combination of STE test and BCOP assay was used compared to when the STE test irritation rank classification was used alone. Moreover, the under prediction rate was substantially improved when this tiered approach was used. From these results, the tiered approach of combining the data analysis of the STE test and BCOP assay might be a promising alternative eye irritation test strategy.

  • validation study of the short time exposure ste test to assess the eye irritation potential of chemicals
    Toxicology in Vitro, 2011
    Co-Authors: Hitoshi Sakaguchi, Yutaka Takahashi, Tsuneaki Nakamura, Hirofumi Kuwahara, Takashi Omori, Takashi Sozu, Yumi Takagi, Kouko Tanigawa, Miki Nakanishi, Takashi Morimoto
    Abstract:

    Abstract Short Time Exposure (STE) test is a cytotoxicity test in SIRC cells (rabbit corneal cell line) that assesses eye irritation potential following a 5-min chemical exposure. This validation study assessed transferability, intra- and inter-laboratory reproducibility, and predictive capacity of STE test in five laboratories (supported by Japanese Society for Alternatives to Animal Experiments). Sodium lauryl sulfate, calcium thioglycolate, and Tween 80 were evaluated, in triplicate, using 5%, 0.5%, and 0.05% concentrations in physiological saline, to confirm transferability. Good transferability was noted when similar mean relative viabilities and rank classifications were obtained in all five laboratories and were comparable to data from test method developing laboratory. Good intra- and inter-laboratory reproducibility was obtained with four assay controls (three solvents and one positive control), and four assay controls and 25 chemicals, respectively. STE irritation category based on relative viability of a 5% solution of 25 blinded test chemicals showed good correlation with Globally Harmonized System (GHS) categories (NI; I: Cat. 1 and 2). The STE prediction model, using relative viability of the 5% and 0.05% solutions, provided an irritation rank (1, 2, or 3) that had a good correlation (above 80%), or predictive capacity, with GHS irritation ranks in all laboratories. Based on these findings, the STE test is a promising alternative eye irritation test that could be easily standardized.

  • The Short Time Exposure (STE) test for predicting eye irritation potential: intra-laboratory reproducibility and correspondence to Globally Harmonized System (GHS) and EU eye irritation classification for 109 chemicals.
    Toxicology in Vitro, 2011
    Co-Authors: Yutaka Takahashi, Mirei Koike, Hitoshi Sakaguchi, Kazuhiko Hayashi, Naohiro Nishiyama
    Abstract:

    Abstract Short Time Exposure (STE) test is an easy in vitro eye irritation test that assesses cytotoxicity in SIRC cells (rabbit corneal cell line) following a 5 min dose treatment. To assess intra-laboratory reproducibility, medium control, three vehicles (saline, saline containing 5% (w/w) dimethyl sulfoxide, and mineral oil) and three standard chemicals (sodium lauryl sulfate, calcium thioglycolate, and Tween 80) were evaluated. Assessments were repeated 30 times for vehicles and 18 times for standard chemicals; resulting in almost the same cell viability and a low coefficient of variation value. In addition, the STE eye irritation rankings of three standard chemicals, as calculated on the cell viabilities in 5% and 0.05% solutions were in agreement in all tests. Based on these results, high intra-laboratory reproducibility was confirmed. In addition, the irritation category (irritant and non-irritant) was evaluated for 109 chemicals with STE test, Globally Harmonized System (GHS) classification, and European Union (EU) classification. The results of the evaluation found the STE classification to have an accuracy with GHS classification of 87% and with EU classification of 83%, which confirmed the excellent correspondence. The correspondence of STE rankings (1, 2, and 3) based on the prediction model by STE test with the eye irritation rankings by GHS (non-irritant, categories 2 and 1) and EU (non-irritant, R36, and R41) was 76% and 71%, respectively. Based on the above results, STE test was considered to be a promising alternative method for assessing eye irritation that has high intra-laboratory reproducibility as well as an excellent predictability of eye irritation.

  • inter laboratory study of short time exposure ste test for predicting eye irritation potential of chemicals and correspondence to Globally Harmonized System ghs classification
    Journal of Toxicological Sciences, 2009
    Co-Authors: Yutaka Takahashi, Mirei Koike, Hitoshi Sakaguchi, Kazuhiko Hayashi, Takumi Hayashi, Shinichi Watanabe, Noriko Aisawa, Shinya Ebata, Tsuneaki Nakamura, Hirofumi Kuwahara
    Abstract:

    Short time exposure (STE) test using rabbit corneal cell line (SIRC) cells was developed as an alternative eye irritation test. STE test uses relative viability as the endpoint after cells are exposed to the test material at constant concentrations for 5 min. In this inter-laboratory study with 3 laboratories, 44 chemicals with a wide range of classes were evaluated for the transferability, between-lab reproducibility and predictive capacity of the STE test as an alternative eye irritation test. Globally Harmonized System (GHS) classification based on Draize eye irritation test data was used as the comparative in vivo data. Transferability was assessed using standard chemicals (sodium lauryl sulfate, calcium thioglycolate, and Tween 80) and the coefficient variations (CVs) of relative viabilities between 3 labs were less than 0.13. The irritation category (Irritant or Non irritant) at each test concentration (5% and 0.05%) in STE test was the same in 3 laboratories for all 44 tested chemicals. The predictive capacity irritation category classification between STE test and GHS were compared, and a good correlation was confirmed (accuracy was 90.9% at all laboratories). In addition, the STE rankings of 1, 2, and 3 classified by the prediction model (PM) based on the relative viability at two concentrations (5% and 0.05%) were highly correlated with the GHS ranks of non-irritant, category 1, and category 2, respectively (accuracy was 75.0% at all laboratories). These results suggest that the STE test possessed easy transferability, reproducibility, good predictive performance.

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  • a new corneal epithelial biomimetic 3d model for in vitro eye toxicity assessment development characterization and applicability
    Toxicology in Vitro, 2020
    Co-Authors: Artur Christian Garcia Da Silva, Adrienny Rodrigues Chialchia, Elisandra Gava De Castro, Marlos R L E Silva, Diego Antonio Costa Arantes, Gregory T Kitten, Aline Carvalho Batista, Marize Campos Valadares
    Abstract:

    Abstract In vitro eye toxicity assessment using reconstructed corneal epithelial models has emerged highlighting its applicability domain for Classification and Labeling of products and chemicals. However, due to bureaucratic issues, such models are not commercially available in Brazil and Latin America. In this work, we developed, characterized and evaluated the applicability of a new corneal epithelial biomimetic model using a cell lineage for in vitro eye toxicity assessment. The reconstructed tissue was obtained through the cultivation of HaCaT cells in an air-liquid interface, which presented morphology and biomarkers expression such as cytokeratin, CD44, and Ki-67 similar to human tissue. Furthermore, tissue viability was evaluated after exposure of the epithelial model to isolated chemicals from different Globally Harmonized System (GHS) eye irritation categories, and it has been demonstrated to be a suitable endpoint for classification of test materials, allowing discrimination between irritant and non-irritant chemicals. Furthermore, the model showed suitability for testing “real-life mixtures”, once it identified irritant products between the analyzed eyebrow henna samples commercially labeled as non-irritants. This reproducible and low-cost epithelial corneal model presents features very important for Brazil and South America for R&D&I with no unnecessary animal experimentation.

  • short time exposure ste test in conjunction with bovine corneal opacity and permeability bcop assay including histopathology to evaluate correspondence with the Globally Harmonized System ghs eye irritation classification of textile dyes
    Toxicology in Vitro, 2015
    Co-Authors: Gisele Augusto Rodrigues De Oliveira, Aline Carvalho Batista, Rafael Ducas, Gabriel Campos Teixeira, Danielle Palma De Oliveira, Marize Campos Valadares
    Abstract:

    Abstract Eye irritation evaluation is mandatory for predicting health risks in consumers exposed to textile dyes. The two dyes, Reactive Orange 16 (RO16) and Reactive Green 19 (RG19) are classified as Category 2A (irritating to eyes) based on the UN Globally Harmonized System for classification (UN GHS), according to the Draize test. On the other hand, animal welfare considerations and the enforcement of a new regulation in the EU are drawing much attention in reducing or replacing animal experiments with alternative methods. This study evaluated the eye irritation of the two dyes RO16 and RG19 by combining the Short Time Exposure (STE) and the Bovine Corneal Opacity and Permeability (BCOP) assays and then comparing them with in vivo data from the GHS classification. The STE test (first level screening) categorized both dyes as GHS Category 1 (severe irritant). In the BCOP, dye RG19 was also classified as GHS Category 1 while dye RO16 was classified as GHS no prediction can be made. Both dyes caused damage to the corneal tissue as confirmed by histopathological analysis. Our findings demonstrated that the STE test did not contribute to arriving at a better conclusion about the eye irritation potential of the dyes when used in conjunction with the BCOP test. Adding the histopathology to the BCOP test could be an appropriate tool for a more meaningful prediction of the eye irritation potential of dyes.

  • in vitro basal cytotoxicity assay applied to estimate acute oral Systemic toxicity of grandisin and its major metabolite
    Experimental and Toxicologic Pathology, 2011
    Co-Authors: Marcelo De Sousa Vieira, Valeria De Oliveira, Eliana Martins Lima, Massuo J Kato, Marize Campos Valadares
    Abstract:

    Abstract Preclinical investigations can start with preliminary in vitro studies before using animal models. Following this approach, the number of animals used in preclinical acute toxicity testing can be reduced. In this study, we employed an in-house validated in vitro cytotoxicity test based on the Spielmann approach for toxicity evaluation of the lignan grandisin, a candidate anticancer agent, and its major metabolite, the 4- O -demethylgrandisin, by neutral red uptake (NRU) assay, on mouse fibroblasts Balb/c 3T3 cell line. Using different concentrations of grandisin and its major metabolite (2.31; 1.16; 0.58; 0.29; 0.14; 0.07; 0.04; 0.002 μM) in Balb/c 3T3-A31 NRU cytotoxicity assay, after incubation for 48 h, we obtained IC 50 values for grandisin and its metabolite of 0.078 and 0.043 μM, respectively. The computed LD 50 of grandisin and 4- O -demethylgrandisin were 617.72 and 429.95 mg/kg, respectively. Both were classified under the Globally Harmonized System as category 4. Since pharmacological and toxicological data are crucial in the developmental stages of drug discovery, using an in vitro assay we demonstrated that grandisin and its metabolite exhibit distinct toxicity profiles. Furthermore, results presented in this work can contribute to reduce the number of animals required in subsequent pharmacological/toxicological studies.