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Biomedical subjects

N Inui

Publications and source records attributed to N Inui.

At least 91 records · Page 5Linked to original sources
PubMed1979

Chromosomal aberrations induced by maleic hydrazide and related compounds in Chinese hamster cells in vitro.

The cytotoxic effects and chromosomal abnormalities induced by maleic hydrazide (MH) and its salts were investigated in cultured V79 cells. MH, and its potassium (K-MH) and diethanolamine (DEA-MH) salts were tested. MH was 5--14 times more cytotoxic than its salts and almost 4.5 times less toxic than the related compound, hydrazine dihydrochloride (HDC). MH salts had very weak cytotoxicity; the LD50 values on V79 cells on exposure for 3 h in vitro were (in microgram/ml) 1100 (MH), 12 000 (DEA-MH), 20 000 (K-MH), 230 (HDC) and 10 000 (NaCl). Both MH and its salts--but neither HDC nor NaCl--caused chromosomal aberrations in cultured V79 cells. The maximal frequencies of aberrant cells in cultures exposed to the compounds for 3 h in vitro were 18% (mh at 100 microgram/ml), 18% (K-MH at 20 000 microgram/ml) and 13% (DEA-MH at 20 000 microgram/ml). Maximal frequencies observed in cultures treated with HDC or NaCl were 10% (HDC at 400 microgram/ml) and 5% NaCl at 10 000 microgram/ml). Those of positive groups were 97% (N-methyl-N'-nitro-N-nitrosoguanidine, MNNG, at 5 microgram/ml) and 16% (ethyl methanesulfonate, EMS, at 400 microgram/ml). These frequencies of MH and its salts were 3.25--4.5 times those in untreated control cells. These results suggested that MH and its salts had weak inducibili

Animals↗
PubMed1979

Transplacental action of sodium nitrite on embryonic cells of Syrian golden hamster.

Hamster embryos were treated with various doses of NaNO2 in utero, by its oral administration to the mothers, and then the embryonic cells were examined for micronucleus formation, chromosomal aberrations, morphological or malignant transformation and drug-resistant mutations. For induction of resistant mutations, the cells were cultured in normal medium for 72 h, and then selected in media containing 8-azaguanine (10 or 20 microgram/ml) or 1 mM ouabain. This treatment with NaNO2 caused marked dose-dependent induction of 8-azaguanine- and ouabain-resistant mutations. Cultured embryonic fibroblasts in the resting state also showed a marked dose-dependent increase in micronucleus formation but not an increase in chromosomal aberrations. This treatment also caused morphological and neoplastic transformation of the cells. Transplacental oral treatment with DMN, as a positive control, caused changes of similar extent in biological effects of embryonic fibroblasts, and in addition it caused chromosomal aberrations in metaphase plates. On the contrary, transplacental oral application of NaNO2 did not induce any biological change in cultured embryonic fibroblasts.

Abnormalities, Drug-Induced↗
PubMed1979

Establishment and characterization of a human neuroblastoma cell line in tissue culture.

A new continuous cell line, GOTO, has been established in tissue culture from a human neuroblastoma arising from the adrenal and maintained for 5 years. The cells are small and fibroblast-like, and grow in dense layer. Population doubling time was approximately 48 hr. The modal chromosome number was near-diploid. Neither marker chromosomes nor double-minute chromosomes were abserved. Inoculum of 10(7) cells produced tumors in ATS-treated hamsters and athymic nude mice, and the histological appearance of tumors was consistent with undifferentiated neuroblastoma. Neural features of the cells were also confirmed by ultrastructural examination. Biochemical analysis showed this cell line to be cholinergic. Morphological differentiation leading to neurite formation was induced by cultivation in serum-free medium.

Adrenal Gland Neoplasms↗
PubMed1978

Mutagenic effect of orally given AF-2 on embryonic cells in pregnant Syrian hamsters.

Pregnant hamsters were given various doses of AF-2 by stomach tube; then the cells of their embryos were isolated and cultured in normal medium. Chromosome preparations were made within 24 h after the start of primary culture, and examined for chromosomal aberrations. Marked chromosomal abnormalities were observed in cells of embryos of animals treated with AF-2 at over 20 mg/kg. Samples of surviving cells were also cultured in normal medium for 48 h, and then selected in medium containing 8AG or 6TG. This treatment with AF-2 caused marked dose-dependent induction of 8AG- or 6TG-resistant mutations: mutant colonies were even obtained after a single treatment with 2 mg of AF-2 per kg. These results show that this is a sensitive and useful mammalian system for detecting environmental mutagens.

Administration, Oral↗
PubMed1978

Chromosome breakage and neoplastic transformation of Syrian golden hamster embryonic cells in tissue culture by transplacental application of 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2).

Hamster embryos were treated with 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2) in vivo (in the mother) by transplacental application. The fetuses were isolated 24 h after administration of the AF-2 and cultured. Within the first 24h of primary culture, some parts of the cells were treated with colcemide for 3 h so that mitotic cells could be observed in the first cell cycle in vitro. Cultured embryonic fibroblasts in metaphase plates showed a marked dose-dependence in chromosomal aberrations. Transplacental application of AF-2 also caused slightly dose-dependent morphological transformation. When some transformed colonies were cloned and transferred to the hamster cheek pouch, these cells produced tumors in the host animals. This new in vivo--in vitro combination assay system is considered to be useful for detection of environmental potential carcinogens.

Animals↗
PubMed1977

Neoplastic transformation induced by furylfuramide and nitromethylfuran of embryonic hamster cells in tissue culture.

Secondary cultures of Syrian hamster embryonic fibroblasts were tested for transformation and neoplastic properties after exposure in vitro to furylfuramine (AF-2) and other nitrofurans. Typical morphological transformation was seen in five of six cultures between 30 and 186 days following treatment with 5-10X10(6) M AF-2 for 24 h. Transformation was seen in only one of four cultures 145 days after treatment for 6 h with AF-2. Treatment with 5-10X10(6) M NMF (5-nitro-2-methylfuran) for 24 h also induced transformation after 50 and 118 days in two cultures. In contrast, untreated cultures and cultures treated with 5-10X10(-6) M NFT [4-(5-nitro-2-furyl)thiazole] for 24 h were not transformed within 200 days. Three of the six lines transformed by AF-2 and both lines transformed by NMF also became tumorigenic 7-24 days after morphologic transformation. The other three transformed lines produced nodules which regressed within a few weeks of transplantation. Untreated and treated non-transformed lines did not produce tumors during an observation period of 6 months. The tumors were classified as fibrosarcomas. The ability to form colonies in soft agar was acquired by only one tumorigenic line.

Animals↗
PubMed1977

Chromosomal aberration, mutation and morphological transformation of Syrian hamster embryonic cells after exposure to methylnitrosocyanamide.

Hamster embryonic fibroblasts were treated directly with various concentrations of methylnitrosocyanamide (MNC), a nitrosated product of methylguanidine (MG) or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Then they were examined for chromosomal aberrations, morphological transformation and mutations resistant to 8-azaguanine (8AG) and 6-thioguanine (6TG). Direct treatment with 2 to 10 X 10(-6) M MNC caused a marked, dose-dependent appearance of 8AG- and 6TG-resistant mutations. The ability of MNC to induce mutations was similar to that of MNNG. Cultured embryonic fibroblasts in metaphase plates also showed a marked dose-dependent increase in chromosomal aberrations within 24 h after direct treatment with MNC or MNNG. Moreover, MNC and MNNG caused similar rates of morphological transformation.

Animals↗
PubMed1976

Mutagenic effects of AF-2, a food additive, on embryonic cells of the Syrian golden hamster on transplacental application.

Hamster embryos were treated with AF-2 in vivo (in the mother) by transplacental application. Their cells were then isolated, cultured in normal medium for 48 h, and then selected in media containing various concentrations of 8AG or 6TG. This treatment with AF-2 caused marked dose-dependent induction of 8AG- or 6TG-resistant mutants. Direct administration of AF-2 and MNNG to embryonic hamster cells also produced 8AG- and 6TG-resistant colonies. This new method is concluded to be very useful for detection of environmental mutagens and carcinogens when combined with the in vivo-in vitro combination assay of chemical carcinogenesis (transformation test).

Acrylamides↗
PubMed1976

In vitro transformation of newborn hamster cells induced by sodium nitrite.

The in vitro carcinogenicity of sodium nitrite was examined. Addition of a high concentration of sodium nitrite (50 mM or 100 mM) to mass cultures of newborn hamster cells for 24 hr resulted in morphological transformation of the cells. The shortest time required for morphological transformation after this treatment was 21 days. Two of 5 transformed cultures produced progressively growing tumors when injected into young adult hamsters. These tumors were diagnosed as fibrosarcomas. In two control cultures of the same experimental groups, transformed cells appeared 10 weeks or more later than those in treated cultures. The chromosomes were analysed at several stages of transformation. In the early stages of transformation, chromosome number varied widely from near diploid to tetraploid, but later they became near diploid. Morphological alteration caused by sodium nitrite was also seen in a short-term assay, in which hamster embryonic cells (1 x 10(4) cells/60 mm dish) were treated and morphology was observed 8 days after the treatment.

Animals↗
PubMed1971

Effect of cigarette tar upon tissue culture cells. Neoplastic transformation of hamster lung cells by tobacco tar in tissue culture.

Hamster lung fibroblastic cells were transformed into malignant cells in vitro by exposure to crude cigarette tar for 3 hours. Primary injuries of cells were observed between 2 and 48 hours after the treatment. Tar-treated cells showed nuclear pyknosis, cell necrosis, and enlarged, vacuolated cytoplasm. In one case giant cells were found at about 48 hours after treatment. Transformation occurred over 100 days after the treatment. The characteristics of transformed cells were random orientation of cells, with piling-up and criss-crossing, and continuous growth in vitro for over 300 days. Plating efficiency with treated cells was different from untreated cells. The transformed cells, cultured for 100 to 160 days, produced tumours when transplanted in cheek pouch of hamsters. The five of nine animals inoculated with 100 μg./ml. of tar treated cells (HT-100 strains) over 160 days in vitro died from tumours and others were killed for histological examinations and one of five animals transplanted with the cells of HT-10 strains within 121 days after the tar treatment. Histologically, the tumours were pleomorphic fibrosarcomas. Low doses (1 × 10(5) or less) of control cells failed to produce tumours after 270 days in culture. Contrarily, higher doses of 10(7) of control cells produced tumours when injected into the animals after 270 days in culture.

Animals↗