The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Satoru Itoh - One of the best experts on this subject based on the ideXlab platform.
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Gender differences in the liver micronucleus test in rats with partial hepatectomy.
Toxicology Letters, 2012Co-Authors: Satoru Itoh, Chiharu Hattori, Mayumi Nagata, Wataru TakasakiAbstract:The liver micronucleus test in rats with partial hepatectomy is a useful method to detect pro-clastogens such as diethylnitrosamine, the active metabolites of which do not reach the bone marrow due to their short lifespan. We have already reported that Structural or numerical Chromosome Aberration inducers should be given before or after partial hepatectomy, respectively, to detect genotoxicity in the liver of rats. In the present study, we found that the percentage of binucleated cells in the liver from naive male rats is approximately 60% of that in female rats, which suggests a gender difference in the response to Chromosome Aberration inducers. Therefore, we investigated the responses to Structural Chromosome Aberration inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and numerical Chromosome Aberration inducers (colchicine and carbendazim) in male and female rats. The chemicals were given to 8-week-old male and female F344 rats a day before or after partial hepatectomy and hepatocytes were isolated 4 days after the partial hepatectomy. As the results, diethylnitrosamine and 1,2-dimethylhydrazine produced a significant increase in the frequency of micronucleated hepatocytes in both genders and the responses were comparable. In the case of colchicine and carbendazim, higher frequencies in the micronucleated hepatocytes were obtained in males than in females. Taken together, the response to Chromosome Aberration inducers in male rats was equal to or stronger than that in female rats. It seems that the use of only male rats in the liver micronucleus test is sufficient, unless existing data indicate a toxicologically meaningful gender difference in rats.
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Structural and numerical Chromosome Aberration inducers in liver micronucleus test in rats with partial hepatectomy
Mutation Research-genetic Toxicology and Environmental Mutagenesis, 2012Co-Authors: Satoru Itoh, Chiharu Hattori, Mayumi Nagata, Atsushi SanbuisshoAbstract:Abstract The liver micronucleus test is an important method to detect pro-mutagens such as active metabolites not reaching bone marrow due to their short lifespan. We have already reported that dosing of the test compound after partial hepatectomy (PH) is essential to detect genotoxicity of numerical Chromosome Aberration inducers in mice [Mutat. Res. 632 (2007) 89–98]. In naive animals, the proportion of binucleated cells in rats is less than half of that in mice, which suggests a species difference in the response to Chromosome Aberration inducers. In the present study, we investigated the responses to Structural and numerical Chromosome Aberration inducers in the rat liver micronucleus test. Two Structural Chromosome aberretion inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and two numerical Chromosome Aberration inducers (colchicine and carbendazim) were used in the present study. PH was performed a day before or after the dosing of the test compound in 8-week old male F344 rats and hepatocytes were isolated 4 days after the PH. As a result, diethylnitrosamine and 1,2-dimethylhydrazine, Structural Chromosome Aberration inducers, exhibited significant increase in the incidence of micronucleated hepatocyte (MNH) when given either before and after PH. Colchicine and carbendazim, numerical Chromosome Aberration inducers, did not result in any toxicologically significant increase in MNH frequency when given before PH, while they exhibited MNH induction when given after PH. It is confirmed that dosing after PH is essential in order to detect genotoxicity of numerical Chromosome Aberration inducers in rats as well as in mice. Regarding the species difference, a different temporal response to colchicine was identified. Colchicine increased the incidence of MNH 4 days after PH in rats, although such induction in mice was observed 8–10 days after PH.
Atsushi Sanbuissho - One of the best experts on this subject based on the ideXlab platform.
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Structural and numerical Chromosome Aberration inducers in liver micronucleus test in rats with partial hepatectomy
Mutation Research-genetic Toxicology and Environmental Mutagenesis, 2012Co-Authors: Satoru Itoh, Chiharu Hattori, Mayumi Nagata, Atsushi SanbuisshoAbstract:Abstract The liver micronucleus test is an important method to detect pro-mutagens such as active metabolites not reaching bone marrow due to their short lifespan. We have already reported that dosing of the test compound after partial hepatectomy (PH) is essential to detect genotoxicity of numerical Chromosome Aberration inducers in mice [Mutat. Res. 632 (2007) 89–98]. In naive animals, the proportion of binucleated cells in rats is less than half of that in mice, which suggests a species difference in the response to Chromosome Aberration inducers. In the present study, we investigated the responses to Structural and numerical Chromosome Aberration inducers in the rat liver micronucleus test. Two Structural Chromosome aberretion inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and two numerical Chromosome Aberration inducers (colchicine and carbendazim) were used in the present study. PH was performed a day before or after the dosing of the test compound in 8-week old male F344 rats and hepatocytes were isolated 4 days after the PH. As a result, diethylnitrosamine and 1,2-dimethylhydrazine, Structural Chromosome Aberration inducers, exhibited significant increase in the incidence of micronucleated hepatocyte (MNH) when given either before and after PH. Colchicine and carbendazim, numerical Chromosome Aberration inducers, did not result in any toxicologically significant increase in MNH frequency when given before PH, while they exhibited MNH induction when given after PH. It is confirmed that dosing after PH is essential in order to detect genotoxicity of numerical Chromosome Aberration inducers in rats as well as in mice. Regarding the species difference, a different temporal response to colchicine was identified. Colchicine increased the incidence of MNH 4 days after PH in rats, although such induction in mice was observed 8–10 days after PH.
Mayumi Nagata - One of the best experts on this subject based on the ideXlab platform.
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Gender differences in the liver micronucleus test in rats with partial hepatectomy.
Toxicology Letters, 2012Co-Authors: Satoru Itoh, Chiharu Hattori, Mayumi Nagata, Wataru TakasakiAbstract:The liver micronucleus test in rats with partial hepatectomy is a useful method to detect pro-clastogens such as diethylnitrosamine, the active metabolites of which do not reach the bone marrow due to their short lifespan. We have already reported that Structural or numerical Chromosome Aberration inducers should be given before or after partial hepatectomy, respectively, to detect genotoxicity in the liver of rats. In the present study, we found that the percentage of binucleated cells in the liver from naive male rats is approximately 60% of that in female rats, which suggests a gender difference in the response to Chromosome Aberration inducers. Therefore, we investigated the responses to Structural Chromosome Aberration inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and numerical Chromosome Aberration inducers (colchicine and carbendazim) in male and female rats. The chemicals were given to 8-week-old male and female F344 rats a day before or after partial hepatectomy and hepatocytes were isolated 4 days after the partial hepatectomy. As the results, diethylnitrosamine and 1,2-dimethylhydrazine produced a significant increase in the frequency of micronucleated hepatocytes in both genders and the responses were comparable. In the case of colchicine and carbendazim, higher frequencies in the micronucleated hepatocytes were obtained in males than in females. Taken together, the response to Chromosome Aberration inducers in male rats was equal to or stronger than that in female rats. It seems that the use of only male rats in the liver micronucleus test is sufficient, unless existing data indicate a toxicologically meaningful gender difference in rats.
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Structural and numerical Chromosome Aberration inducers in liver micronucleus test in rats with partial hepatectomy
Mutation Research-genetic Toxicology and Environmental Mutagenesis, 2012Co-Authors: Satoru Itoh, Chiharu Hattori, Mayumi Nagata, Atsushi SanbuisshoAbstract:Abstract The liver micronucleus test is an important method to detect pro-mutagens such as active metabolites not reaching bone marrow due to their short lifespan. We have already reported that dosing of the test compound after partial hepatectomy (PH) is essential to detect genotoxicity of numerical Chromosome Aberration inducers in mice [Mutat. Res. 632 (2007) 89–98]. In naive animals, the proportion of binucleated cells in rats is less than half of that in mice, which suggests a species difference in the response to Chromosome Aberration inducers. In the present study, we investigated the responses to Structural and numerical Chromosome Aberration inducers in the rat liver micronucleus test. Two Structural Chromosome aberretion inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and two numerical Chromosome Aberration inducers (colchicine and carbendazim) were used in the present study. PH was performed a day before or after the dosing of the test compound in 8-week old male F344 rats and hepatocytes were isolated 4 days after the PH. As a result, diethylnitrosamine and 1,2-dimethylhydrazine, Structural Chromosome Aberration inducers, exhibited significant increase in the incidence of micronucleated hepatocyte (MNH) when given either before and after PH. Colchicine and carbendazim, numerical Chromosome Aberration inducers, did not result in any toxicologically significant increase in MNH frequency when given before PH, while they exhibited MNH induction when given after PH. It is confirmed that dosing after PH is essential in order to detect genotoxicity of numerical Chromosome Aberration inducers in rats as well as in mice. Regarding the species difference, a different temporal response to colchicine was identified. Colchicine increased the incidence of MNH 4 days after PH in rats, although such induction in mice was observed 8–10 days after PH.
Chiharu Hattori - One of the best experts on this subject based on the ideXlab platform.
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Gender differences in the liver micronucleus test in rats with partial hepatectomy.
Toxicology Letters, 2012Co-Authors: Satoru Itoh, Chiharu Hattori, Mayumi Nagata, Wataru TakasakiAbstract:The liver micronucleus test in rats with partial hepatectomy is a useful method to detect pro-clastogens such as diethylnitrosamine, the active metabolites of which do not reach the bone marrow due to their short lifespan. We have already reported that Structural or numerical Chromosome Aberration inducers should be given before or after partial hepatectomy, respectively, to detect genotoxicity in the liver of rats. In the present study, we found that the percentage of binucleated cells in the liver from naive male rats is approximately 60% of that in female rats, which suggests a gender difference in the response to Chromosome Aberration inducers. Therefore, we investigated the responses to Structural Chromosome Aberration inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and numerical Chromosome Aberration inducers (colchicine and carbendazim) in male and female rats. The chemicals were given to 8-week-old male and female F344 rats a day before or after partial hepatectomy and hepatocytes were isolated 4 days after the partial hepatectomy. As the results, diethylnitrosamine and 1,2-dimethylhydrazine produced a significant increase in the frequency of micronucleated hepatocytes in both genders and the responses were comparable. In the case of colchicine and carbendazim, higher frequencies in the micronucleated hepatocytes were obtained in males than in females. Taken together, the response to Chromosome Aberration inducers in male rats was equal to or stronger than that in female rats. It seems that the use of only male rats in the liver micronucleus test is sufficient, unless existing data indicate a toxicologically meaningful gender difference in rats.
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Structural and numerical Chromosome Aberration inducers in liver micronucleus test in rats with partial hepatectomy
Mutation Research-genetic Toxicology and Environmental Mutagenesis, 2012Co-Authors: Satoru Itoh, Chiharu Hattori, Mayumi Nagata, Atsushi SanbuisshoAbstract:Abstract The liver micronucleus test is an important method to detect pro-mutagens such as active metabolites not reaching bone marrow due to their short lifespan. We have already reported that dosing of the test compound after partial hepatectomy (PH) is essential to detect genotoxicity of numerical Chromosome Aberration inducers in mice [Mutat. Res. 632 (2007) 89–98]. In naive animals, the proportion of binucleated cells in rats is less than half of that in mice, which suggests a species difference in the response to Chromosome Aberration inducers. In the present study, we investigated the responses to Structural and numerical Chromosome Aberration inducers in the rat liver micronucleus test. Two Structural Chromosome aberretion inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and two numerical Chromosome Aberration inducers (colchicine and carbendazim) were used in the present study. PH was performed a day before or after the dosing of the test compound in 8-week old male F344 rats and hepatocytes were isolated 4 days after the PH. As a result, diethylnitrosamine and 1,2-dimethylhydrazine, Structural Chromosome Aberration inducers, exhibited significant increase in the incidence of micronucleated hepatocyte (MNH) when given either before and after PH. Colchicine and carbendazim, numerical Chromosome Aberration inducers, did not result in any toxicologically significant increase in MNH frequency when given before PH, while they exhibited MNH induction when given after PH. It is confirmed that dosing after PH is essential in order to detect genotoxicity of numerical Chromosome Aberration inducers in rats as well as in mice. Regarding the species difference, a different temporal response to colchicine was identified. Colchicine increased the incidence of MNH 4 days after PH in rats, although such induction in mice was observed 8–10 days after PH.
Francesco Lamonaca - One of the best experts on this subject based on the ideXlab platform.
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Automatic Detection and Surface Measurements of Micronucleus by a Computer Vision Approach
IEEE Transactions on Instrumentation and Measurement, 2010Co-Authors: Michele Ceccarelli, Domenico Grimaldi, Antonio Speranza, Francesco LamonacaAbstract:This paper reports a novel method for nucleus and micronucleus segmentation. These biological structures are useful to biologists for relieving Structural Chromosome Aberration. The adopted method consists of a pipeline of advanced computer vision algorithms, some of them were specifically tailored for the current segmentation problem. Starting from the weak hypotheses on size, shape, and color of micronucleus, it is possible to efficiently segment and measure the image features of interest by a computer vision approach. We report experimental results with a new flow cytometer architecture specifically developed to recognize and measure micronucleus of human lymphocyte. The robustness of the algorithm with respect to various kinds of noise is also reported.
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A computer vision approach to Micro-Nucleus automatic detection and surface measurements
2009 IEEE International Workshop on Medical Measurements and Applications, 2009Co-Authors: Michele Ceccarelli, Domenico Grimaldi, Francesco Lamonaca, Antonio SperanzaAbstract:This paper reports a novel method for Nucleus and Micro Nucleuses segmentation. These biological structures are very handy to biologists for relieving Structural Chromosome Aberration. The adopted method consists into a pipeline of advanced computer vision algorithms some of them specifically tailored for the current segmentation problem. Starting from weak hypotheses on size, shape and colour of Micro Nucleuses it is possible to efficiently segment all the image features by computer vision approach. Experimental results on real images are reported.
