T. Sofuni

Publication List Details

Period

1992 - 2003

Number

35

Co-Authors

Aneuploidy induction by benzo[a]pyrene and polyploidy induction by 7,12-dimethylbenz[a]anthracene in Chinese hamster cell lines V79-MZ and V79 (1997)

Matsuoka, A., Ozaki, M., Takeshita, K., Sakamoto, H., Hayashi, M., ...

We found that different ploidy effects were induced in four Chinese hamster-derived cell lines (V79-MZ, V79, CHL and CHO-K1) treated through two cell cycles with polycyclic aromatic hydrocarbons in...

Detection of in vitro clastogens and spindle poisons by the mouse lymphoma assay using the micro well method: interim report of an international collaborative study (1996)

Sofuni, T., Honma, M., Hayashi, M., Shimada, H., Tanaka, N., Wakuri, S., ...

Under the auspices of the Ministry of Health and Welfare of Japan and the Japanese Pharmaceutical Manufacturer Association, a collaborative study of the mouse lymphoma assay (MLA) was conducted by 42...

Regionally-targeted mutagenesis by metabolically-activated steviol: DNA sequence analysis of steviol-induced mutants of guanine phosphoribosyltransferase (gpt) gene of Salmonella typhimurium TM677 (1996)

Matsui, M., Sofuni, T., Nohmi, T.

Steviol is the aglycone of stevioside, a non–caloric sugar substitute commonly used in Japan. Steviol strongly induces mutations at the guanine phosphoribosyltransferase gene (gpt) of Salmonella...

Evaluation of the genotoxicity of stevioside and steviol using six in vitro and one in vivo mutagenicity assays (1996)

Matsui, M., Matsui, K., Kawasaki, Y., Oda, Y., Noguchi, T., Kitagawa, Y., ...

Stevioside, a constituent of Stevia rebaudiana, is commonly used as a non-caloric sugar substitute in Japan. The genetic toxicities of stevioside and its aglycone, steviol, were examined with seven...

Chromosome painting analysis of X-ray-induced aberrations in human lymphocytes in vitro (1994)

Matsuoka, A., Tucker, J.D., Hayashi, M., Yamazaki, N., Sofuni, T.

Chromosomal rearrangements in human lymphocytes induced by X-rays (0, 0.5, 1.0 and 2.0 Gray) were analyzed using chromosome painting. DNA probes for human chromosomes 1, 3 or 4 alone, and a...

Construction and characterization of mutants of Salmonella typhimurium deficient in DNA repair of O6-methylguanine.

Yamada, M, Sedgwick, B, Sofuni, T, Nohmi, T

Escherichia coli has two O6-methylguanine DNA methyltransferases that repair alkylation damage in DNA and are encoded by the ada and ogt genes. The ada gene of E. coli also regulates the adaptive...

New method for gene disruption in Salmonella typhimurium: construction and characterization of an ada-deletion derivative of Salmonella typhimurium TA1535.

Yamada, M, Hakura, A, Sofuni, T, Nohmi, T

A new method for gene disruption in Salmonella typhimurium was developed. The key steps of this method are to produce restriction fragments with compatible ends, preligate to produce concatemers, and...

Salmonella typhimurium has two homologous but different umuDC operons: cloning of a new umuDC-like operon (samAB) present in a 60-megadalton cryptic plasmid of S. typhimurium.

Nohmi, T, Hakura, A, Nakai, Y, Watanabe, M, Murayama, S Y, Sofuni, T

Expression of the umuDC operon is required for UV and most chemical mutagenesis in Escherichia coli. The DNA which can restore UV mutability to a umuD44 strain and to a umuC122::Tn5 strain of E. coli...

Roles of Salmonella typhimurium umuDC and samAB in UV mutagenesis and UV sensitivity.

Nohmi, T, Yamada, M, Watanabe, M, Murayama, S Y, Sofuni, T

Expression of the umuDC operon is required for UV mutagenesis and most chemical mutagenesis in Escherichia coli. The closely related species Salmonella typhimurium has two sets of umuDC-like operons;...

Cloning and characterization of the Salmonella typhimurium ada gene, which encodes O6-methylguanine-DNA methyltransferase.

Hakura, A, Morimoto, K, Sofuni, T, Nohmi, T

The ada gene of Escherichia coli encodes O6-methylguanine-DNA methyltransferase, which serves as a positive regulator of the adaptive response to alkylating agents and as a DNA repair enzyme. The...

Illegitimate recombination leading to allelic loss and unbalanced translocation in p53-mutated human lymphoblastoid cells.

Honma, M, Zhang, L S, Hayashi, M, Takeshita, K, Nakagawa, Y, Tanaka, N, ...

Allelic loss and translocation are critical mutational events in human tumorigenesis. Allelic loss, which is usually identified as loss of heterozygosity (LOH), is frequently observed at tumor...

N-hydroxyarylamine O-acetyltransferase of Salmonella typhimurium: proposal for a common catalytic mechanism of arylamine acetyltransferase enzymes.

Watanabe, M, Igarashi, T, Kaminuma, T, Sofuni, T, Nohmi, T

Acetyl-CoA:N-hydroxyarylamine O-acetyltransferase is an enzyme involved in the metabolic activation of N-hydroxyarylamines derived from mutagenic and carcinogenic aromatic amines and nitroarenes. The...

Statistical analysis of data in mutagenicity assays: rodent micronucleus assay.

Hayashi, M, Hashimoto, S, Sakamoto, Y, Hamada, C, Sofuni, T, Yoshimura, I

To evaluate chemical safety, many kinds of short-term mutagenicity assays are performed together with long-term assays in animals. Rationales and methodology for these assays have been well discussed...

Toxicology testing requirements and the U.S.–Japan Collaborative Study on in vitro tests for chromosomal aberrations

Shelby, M. D., Sofuni, T.

As part of the U.S.–Japan Agreement on Cooperation in Research and Development in Science and Technology, Japanese and American scientists met in North Carolina to exchange information on...

The expert system for toxicity prediction of chemicals based on structure-activity relationship.

Nakadate, M, Hayashi, M, Sofuni, T, Kamata, E, Aida, Y, Osada, T, ...

The prediction systems of chemical toxicity has been developed by means of structure-activity relationship based on the computerized fact database (BL-DB). Numbers and ratio of elements, side chains,...

Construction and characterization of mutants of Salmonella typhimurium deficient in DNA repair of O6-methylguanine.

Yamada, M, Sedgwick, B, Sofuni, T, Nohmi, T

Escherichia coli has two O6-methylguanine DNA methyltransferases that repair alkylation damage in DNA and are encoded by the ada and ogt genes. The ada gene of E. coli also regulates the adaptive...

New method for gene disruption in Salmonella typhimurium: construction and characterization of an ada-deletion derivative of Salmonella typhimurium TA1535.

Yamada, M, Hakura, A, Sofuni, T, Nohmi, T

A new method for gene disruption in Salmonella typhimurium was developed. The key steps of this method are to produce restriction fragments with compatible ends, preligate to produce concatemers, and...

Salmonella typhimurium has two homologous but different umuDC operons: cloning of a new umuDC-like operon (samAB) present in a 60-megadalton cryptic plasmid of S. typhimurium.

Nohmi, T, Hakura, A, Nakai, Y, Watanabe, M, Murayama, S Y, Sofuni, T

Expression of the umuDC operon is required for UV and most chemical mutagenesis in Escherichia coli. The DNA which can restore UV mutability to a umuD44 strain and to a umuC122::Tn5 strain of E. coli...

Roles of Salmonella typhimurium umuDC and samAB in UV mutagenesis and UV sensitivity.

Nohmi, T, Yamada, M, Watanabe, M, Murayama, S Y, Sofuni, T

Expression of the umuDC operon is required for UV mutagenesis and most chemical mutagenesis in Escherichia coli. The closely related species Salmonella typhimurium has two sets of umuDC-like operons;...

Cloning and characterization of the Salmonella typhimurium ada gene, which encodes O6-methylguanine-DNA methyltransferase.

Hakura, A, Morimoto, K, Sofuni, T, Nohmi, T

The ada gene of Escherichia coli encodes O6-methylguanine-DNA methyltransferase, which serves as a positive regulator of the adaptive response to alkylating agents and as a DNA repair enzyme. The...

Illegitimate recombination leading to allelic loss and unbalanced translocation in p53-mutated human lymphoblastoid cells.

Honma, M, Zhang, L S, Hayashi, M, Takeshita, K, Nakagawa, Y, Tanaka, N, ...

Allelic loss and translocation are critical mutational events in human tumorigenesis. Allelic loss, which is usually identified as loss of heterozygosity (LOH), is frequently observed at tumor...

N-hydroxyarylamine O-acetyltransferase of Salmonella typhimurium: proposal for a common catalytic mechanism of arylamine acetyltransferase enzymes.

Watanabe, M, Igarashi, T, Kaminuma, T, Sofuni, T, Nohmi, T

Acetyl-CoA:N-hydroxyarylamine O-acetyltransferase is an enzyme involved in the metabolic activation of N-hydroxyarylamines derived from mutagenic and carcinogenic aromatic amines and nitroarenes. The...

Statistical analysis of data in mutagenicity assays: rodent micronucleus assay.

Hayashi, M, Hashimoto, S, Sakamoto, Y, Hamada, C, Sofuni, T, Yoshimura, I

To evaluate chemical safety, many kinds of short-term mutagenicity assays are performed together with long-term assays in animals. Rationales and methodology for these assays have been well discussed...

Toxicology testing requirements and the U.S.–Japan Collaborative Study on in vitro tests for chromosomal aberrations

Shelby, M. D., Sofuni, T.

As part of the U.S.–Japan Agreement on Cooperation in Research and Development in Science and Technology, Japanese and American scientists met in North Carolina to exchange information on...

The expert system for toxicity prediction of chemicals based on structure-activity relationship.

Nakadate, M, Hayashi, M, Sofuni, T, Kamata, E, Aida, Y, Osada, T, ...

The prediction systems of chemical toxicity has been developed by means of structure-activity relationship based on the computerized fact database (BL-DB). Numbers and ratio of elements, side chains,...