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Biomedical subjects

M Matsui

Publications and source records attributed to M Matsui.

At least 523 records · Page 29Linked to original sources
PubMed1982

Organotropic effect of N-nitroso-bis-(2-hydroxypropyl)-amine: production of lung adenocarcinoma in rats by a single intraperitoneal injection.

The carcinogenic effect of a single intraperitoneal injection of N-bis(2-hydroxypropyl)nitrosamine (DHPN) was studied in male Wistar rats for 52 weeks. Adenomas were induced in 100% of rats treated with more than 2 g/kg body weight DHPN. Adenocarcinomas were induced in 7%, 25%, 86% and 74% of rats treated with 1, 2, 3 and 4 g/kg body weight, respectively. The labelling index studied by 3H-thymidine autoradiography was 0.33% in normal alveoli, 0.49% in bronchiole, 0.62% in focal cell proliferative area, 1.22% in adenoma, 1.70% in tubular adenocarcinoma and 2.81% in papillary adenocarcinoma. Fewer tumours were induced in the thyroid, kidney and sigmoid colon. Only one pancreatic tumour was observed in a rat treated with 3 g DHPN/kg body weight. These results indicate that, in rats, the lung is the organ most responsive to a single treatment with DHPN.

Adenocarcinoma↗
PubMed1981

A spin-label study of protein-lipid interaction in sarcoplasmic reticulum of rabbit skeletal muscle.

Whether or not the thermotropic change at about 18 degrees C in the physical state of Ca2+-ATPase protein molecules of sarcoplasmic reticulum membranes could be transmitted to lipids through protein-lipid interactions was investigated using a spin-label technique. Fatty acid spin labels were used to probe the bulk membrane lipids while long-chain spin labels attached at one end to the Ca2+-ATPase molecules through a covalent bond were used to monitor the boundary lipids. The results on the temperature-dependence of alkyl-chain flexibility of lipid molecules indicate that the change in the state of the protein molecules is accompanied by one of the boundary lipids, but not of the bulk lipids.

Animals↗
PubMed1981

Chemical screening of radiation protecting agents.

An aqueous solution of 2-propanol was chosen as chemical system for fundamental study of the chemical screening of organic compounds on the responsibility for ionizing radiation. The effect of additives on the yield of acetone was investigated by subjecting this system on gamma-radiolysis. The results show that this system is suitable for the estimation of radiation protecting character of the known radiation protecting agents and compounds which act as a OH scavenger. On the basis of these results, various nitrogen-containing additives having free amino group, guanidine group and hetero-cyclic amine were examined first of all in expectation of improvement for the toxicity of sulfur-containing compounds.

1-Propanol↗
PubMed1980

Two new C3H mouse ascites tumor cell lines capable of proliferation in vivo and in suspension culture: morphological, karyological, kinetic and immunological properties.

The establishment of mouse tumor cell lines capable of proliferating in vivo and in suspension culture was undertaken. The MM-46 tumor line, initiated from primary mammary carcinoma arising in a C3H/He mouse, was maintained for over 100 generations in the peritoneal cavities of syngenic mice. At the 50th generation of the tumor suspension, cultures were initiated. The established cell lines, designated TMT-1 and TMT-2, were characterized in vitro and in vivo. The morphological finding indicated that THT-1 and TMT-2 cells from mice closely resembled the MM-46 tumor cells. The oncogenic potential of the cultured cells was comparable to that of the original ascites tumor. The population doubling time of TMT-1 and TMT-2 cell lines was about 12 hr in mice, whereas the population doubling time of both cell lines lengthened to 20 hr in suspension culture. The increase in doubling time in culture was due to the prolongation of the G1 period. The cell lines, TMT-1 and TMT-2, whether fropm culture or mice, possessed colony forming ability in in soft agar medium. The colony forming ability of the cells decreased gradually through in vivo passages but it recovered upon recultivation of the cells from mouse to culture. Chromosome analysis and cytotoxicity test by anti-MM antiserum indicated that TMT-1 and TMT-2 cell lines closely resembled and had been derived from MM-46 tumor line. Therefore, it is possible to assay cell survival in vitro after in vivo experiments on these cells.

Animals↗
PubMed1980

Induction of liver tumors in Wistar rats by sodium nitrite given in pellet diet.

Sodium nitrate was given to male noninbred Wistar rats at levels of 800 ppm and 1,600 ppm in a pellet diet for 646 experimental days. The first tum or was found on day 441 in the liver of a rat given a diet containing 800 ppm sodium nitrite. On day 646, liver tumors were found in 1 of 22 rats (4.5%) on an 800-ppm sodium nitrite diet and in 5 of 19 rats (26.3%) on a 1,600-ppm sodium nitrite diet. The incidence of liver tumors in the rats fed 1,600 ppm sodium nitrite was significantly different from that in controls as judged by the t-test (P < 0.05). A hepatocellular carcinoma and a hemangioendothelial sarcoma of the liver were found on day 646 in 2 rats fed 1,600 ppm sodium nitrite. One mammary tumor but no liver tumors were found in the 19 control rats. The concentration of sodium nitrite decreased after preparation of the pellet diet, but it was still at least 70% of the initial amount when the pellets were given to the rats. Volatile N-nitroso compounds, especially dimehylnitrosamine, at ppm levels were detected in the pellet diet with a gas chromatography-thermal energy analyzer.

Adenoma↗
PubMed1980

Occurrence, formation and precursors of N-nitroso compounds in the Japanese diet.

A survey has been made of volatile nitrosamines in 123 fermented foods. These included salt-fermented vegetables, soy sauce, "miso", Japanese "sake" and other fermentation products. No appreciable amount, or only trace quantities, of NDMA and NPYR were detected in vinegar, "sake", wines and whiskies, while minute quantities of NDMA were detected in 31 out of 33 beer samples, where the levels ranged from traces to 13.8 micrograms/l, with an average of 5.1 micrograms/l. The nitrosamine content of salt-dried fish apparently increased when these products were broiled in a city gas range. A method for the determination of N-alkylureas in foods has been developed. A total of 57 food samples, both uncooked and broiled in a gas range or fried, were analysed. No alkylureas could be detected in these samples.

Animals↗