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Biomedical subjects

T Takata

Publications and source records attributed to T Takata.

At least 199 records · Page 11Linked to original sources
PubMed1983

Ultrastructural cytochemical demonstration of elastin in the matrix of salivary gland tumors.

Following light microscopic survey of the incidence of elastic tissue in 80 salivary gland tumors, tissue samples from 14 pleomorphic adenomas, three myoepitheliomas, and eight adenoid cystic carcinomas were processed for cytochemical demonstration of elastin with the tannic acid stain for ultra-thin sections. For comparative study, some other tumor types devoid of elastic tissue at the light microscopic level and non-neoplastic submandibular glands were also investigated. Elastic deposits of varying amounts were clearly revealed on the basal-lamina-like material and/or masses of microfibrils in the matrix close to the neoplastic myoepithelium and, to a lesser degree, immediately beneath the non-neoplastic myoepithelium. None of the other tumor types without myoepithelial differentiation contained elastic deposits closely associated with the neoplastic cells. Intimate topographical relationship of such as immature elastic fiber or developing elastic tissue to the neoplastic myoepithelial cells strongly indicated the primary origin of elastic components from these cells. It is postulated that the potential of salivary tumor cells to produce elastin is regarded as an indicator of their myoepithelial nature or differentiation.

Adenoma↗
PubMed1982

Effects of cadmium on the level of serum corticosterone and adrenocortical function in male and female rats.

The present study was designated to obtain information about the effects of cadmium (Cd) on the level of serum corticosterone and on the adrenocortical function in male and female rats. The animals were injected twice a day with cadmium chloride at a dose of 1 mg/Kg of body weight for 2 and 7 consecutive days. After Cd treatment for 2 and 7 consecutive days, the adrenal weight increased and the level of serum corticosterone decreased in male and female rats. The steroid response to injected ACTH of the treated rats of both sexes was similar to that of the control rats but there was a marked increase in the disappearance rate of corticosterone from plasma in Cd-treated rats of both sexes. These results suggest that the low level of serum corticosterone in Cd-treated rats of both sexes is due to the marked increase in the disappearance rate of corticosterone from plasma.

Adrenal Cortex↗
PubMed1981

[The effects of zinc on cadmium-induced ultrastructural changes in rat livers (author's transl)].

The superimposed effects of oral zinc administration on cadmium-induced ultrastructural changes in rat livers were studied. Twenty female rats were divided into 4 groups. To the diet for group I was added 200 ppm Cd for daily about 10 g diet, to that for group II 200 ppm of Zn and that for group III 200 ppm of Cd and Zn each. The group IV was the control. All of the four groups was sacrificed after 9 months of administration. In addition to examine the liver by an electron-microscope, Cd concentration in the liver was analyzed by atomic absorption spectrophotometry. The Cd contents in the livers of group III were significantly reduced compared with those of group I. Apparent ultrastructural changes; i.e., deterioration of rough endoplasmic reticula, losses of glycogen particles, and proliferation of smooth endoplasmic reticula, were observed in the livers of group I. Meanwhile, these changes were significantly mild in those of group III. From these results, it is suggested that Cd inhibits protein synthesis and glycogen metabolism in the liver and that Zn partly protects the liver from Cd-induced ultrastructural changes.

Animals↗
PubMed1981

[Adsorption and desorption of organic solvent vapours using silica gel (author's transl)].

For a simple analysis of organic solvent vapours in working environmental air, we investigated the following method. First, join the adsorption tube (2 ml of 60--80 mesh silica gel packed in a 5 mm phi x 18 cm glass tube) to hand vacuum pump and suck 200 ml of the sample air. After adsorption, join this adsorption tube to the sampling bottle under reduced pressure. Second, open the cock of the sampling bottle and heat only the adsorption tube in an oven for 3 min. In the operation mentioned above, organic solvent vapours desorbed from the silica gel transfer smoothly into the sampling bottle. After desorption, take 1 ml of air from the sampling bottle and determine the sample quantities with the gas chromatograph. Sample solvents used were as follows: n-hexane, cyclohexane, benzene, toluene, m-xylene, styrene, 1.1.1-trichloroethane, dichloromethane, tetrachloroethylene, ethylacetate, acetone, methyl-ethylketone, methylisobutylketone, methanol, ethanol, n-propanol, and n-butanol. We obtained the following results. (1) 60--80 mesh silica gel is appropriate for this method. (2) Heating temperature to get 100% recovery varies with the type of organic solvent. m-Xylene and styrene require 250 degrees C, methylisobutylketone and n-butanol 200 degrees C, and the others 150 degrees C. (3) If the adsorption tube is preserved in a freezer at -20 degrees C, no decrease is observed for up to 7 days. At room temperatures, however, 1.1.1-trichloroethane, dichloromethane, tetrachloroethylene, n-hexane, and cyclohexane decreased by the amount 4-10% in the tube for each 24-hour period. These sample should be preserved at lower temperatures soon after absorbing on the silica gel. This method is simple and accurate, so valid for analysis of organic solvent vapours in the working environmental air.

Air Pollutants↗
PubMed1977

Microbiological degradation of bile acids. The preparation of hexahydroindane derivatives as substrates for studying cholic acid degradation.

Relatively large amounts of 3-(3aalpha-hexahydro-7abeta-methyl-1,5-dioxoindan-4alpha-yl)propionic acid (IIb), which is believed to be one of the intermediates involved in the degradation of cholic acid (I), were needed to identify is further degradation products. A simple method for the preparation of this compound was then investigated. Arthrobacter simplex could degrade-3-oxoandrost-4-ene-17beta-carboxylic acid (IIIa) to 3-(1beta-carboxy-3aalpha-hexahydro-7abeta-methyl-5-oxoindan-4alpha-yl)propionic acid (IVa) in good yield, the structure of which was established by partial synthesis. It was therefore expected that, if a similar degradation by this organism occurred with 17alpha-hydroxy-3-oxoandrost-4-ene-17beta-carboxylic acid (IIIb), which is easily obtained by chemical oxidation of commercially availabe 17alpha-hydroxydeoxycorticosterone, the resulting product, 3-(1beta-carboxy-3aalpha-hexahydro-1alpha-hydroxy-7abeta-methyl-5-oxoindan-4alpha-yl)propionic acid (IVb), could be readily converted chemically into the required dioxocarboxylic acid, (IIb). Exposure of compound (IIIb) to A. simplex produced, as expected, compound (IVb) which was then oxidized with NaBiO3 to give a reasonable yield of compound (IIb).

Arthrobacter↗