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Biomedical subjects

T Masui

Publications and source records attributed to T Masui.

At least 163 records · Page 9Linked to original sources
PubMed1984

Promotive effect of primary and secondary bile acids on the induction of gamma-glutamyl transpeptidase-positive liver cell foci as a possible endogenous factor for hepatocarcinogenesis in rats.

The promoting effects of 5 bile acids on liver carcinogenesis were investigated in male Fischer rats initially treated with diethylnitrosamine (DEN). Two weeks after a single dose of DEN (200 mg/kg, intraperitoneally), rats were given bile acids for 8 weeks. At 3 weeks following DEN administration, all rats were subjected to partial hepatectomy. Among the bile acids tested, cholic acid (CA) and deoxycholic acid (DCA) exerted promoting activity as evidenced by significantly increased values of gamma-glutamyl transpeptidase-positive (gamma-GT+) foci as compared with the corresponding controls given DEN alone. In contrast, the other 3 bile acids tested, chenodeoxycholic acid (CDCA), lithocholic acid (LCA) and ursodeoxycholic acid (UDCA), did not significantly increase the level of gamma-GT+ foci over that induced by DEN alone. It is noteworthy that only bile acids of the same metabolic pathway, CA as a primary bile acid and DCA as a secondary bile acid, showed promoting effects whereas CDCA and its metabolic derivatives, LCA and UDCA, were inactive. The results indicate that CA and DCA might act as endogenous promoters of hepatocarcinogenesis in pathological conditions with increased levels of serum bile acids.

Animals↗
PubMed1984

Modifying potential of thirty-one chemicals on the short-term development of gamma-glutamyl transpeptidase-positive foci in diethylnitrosamine-initiated rat liver.

The modifying potential of 31 different compounds on the development of gamma-glutamyl transpeptidase-positive (gamma-GT+) liver cell lesions was compared in an in vivo short-term assay system. Rats were initially given a single dose (200 mg/kg) of diethylnitrosamine intraperitoneally and 2 weeks later were treated with test compounds for 6 weeks and then sacrificed, all rats being subjected to partial hepatectomy at week 3. Modifying potential was scored by comparing the number and area (mm2)/cm2 of induced gamma-GT+ foci with those of the corresponding control group given DEN alone. 2-Acetylaminofluorene, 3'-methyl-4-dimethylaminoazobenzene, dimethylnitrosamine, phenobarbital, barbital, dipyrone and deoxycholic acid caused a significant enhancement of both the number and area of foci. 4-Acetylaminofluorene, ethionine, benzo[alpha]pyrene, disulfiram and cholic acid had a moderate enhancing effect, whereas slight, but not unequivocal, increases in gamma-GT+ foci were observed after captafol, glutathione, sodium ascorbate and taurine administration. In contrast, acetaminophen, ethoxyquin, butylated hydroxyanisole, butylated hydroxytoluene, and ethyl alcohol showed clear inhibitory effects. It is concluded that the present short-term in vivo system has practical application for the screening of modifying agents for liver tumorigenesis including hepatocarcinogens.

Animals↗
PubMed1984

Promoting activities of butylated hydroxyanisole, butylated hydroxytoluene and sodium L-ascorbate on forestomach and urinary bladder carcinogenesis initiated with methylnitrosourea in F344 male rats.

The promoting effects of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and sodium L-ascorbate on two-stage carcinogenesis initiated with methylnitrosourea (MNU) in F344 male rats were investigated. Animals were given injections of MNU (20 mg/kg ip) twice a week for 4 weeks, and then basal diet containing 2% BHA, 1% BHT or 5% sodium L-ascorbate for the next 32 weeks. Administration of BHA, BHT or sodium L-ascorbate in the diet significantly increased the incidences per group and numbers per rat of papilloma and papillary or nodular hyperplasia of the urinary bladder, and BHA and BHT also increased the number of cancers per rat. Furthermore BHA significantly increased the incidences of cancer and papilloma in the forestomach of rats initiated with MNU, whereas treatment with BHA alone was associated with papilloma but no carcinoma development in the rat forestomach. The incidence of adenoma, but not adenocarcinoma, of the thyroid was significantly increased by treatment with MNU plus BHT. These results show that BHA, BHT and sodium L-ascorbate have promoting activities on urinary bladder carcinogenesis in rats initiated with MNU, and that BHA also has a promoting effect on forestomach carcinogenesis after initiation with MNU.

Animals↗
PubMed1983

[Pre-verbality in focusing and the need for self check. An attempt at "focusing check"].

Though the Focusing process is not entirely non-verbal, in Focusing, careful attention is paid by the Focuser and the Listener to the pre-verbal experiential process. In other words, Focusing involves attending to the felt sense that is not easily expressed in words immediately. Hence, during the process of learning to Focus, the Focusing teacher attempts to communicate the experiences of Focusing to the student which are not easily done by words. Due to such difficulties, the Focusing student may (and quite frequently does) mistake the experiential process in Focusing with other processes. Often, the felt sense can be confused with other phenomena such as "autogenic discharge". Also the Focuser may not stay with the felt sense and drift into "free association" or frequently, certain processes in "meditation" can be confused with Focusing. Therefore, there is a need for a "check" by which the Focusing student can confirm the Focusing experience for himself. For the Focusing student, such a "check" serves not only to confirm the Focusing process, but also an aid to learning Focusing. We will report here a "Focusing Check" which we developed by translating Eugene Gendlin's "Focusing Check" and making several modifications in it so that it will be more understandable to the Japanese. Along with the "Focusing Check" we developed, the authors discuss the need for such a check.

Attention↗
PubMed1983

Dose and sex dependent effects of 2-acetylaminofluorene, 3'-methyl-4-dimethylaminoazobenzene and DL-ethionine in induction of gamma-glutamyl transpeptidase-positive liver cell foci in rats.

The dose-dependent and sex-related effects of 3 hepatocarcinogens were investigated by measuring the number and area of gamma-glutamyl transpeptidase (gamma-GT) positive foci appearing in the liver. For this, three different doses of 2-acetylaminofluorene (2-AAF), 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) and DL-ethionine (ethionine), respectively, were given to F344 rats of both sexes for 6 weeks after a single injection of diethylnitrosamine (DEN). The inductions of gamma-GT positive foci by 2-AAF and 3'-Me-DAB were clearly dose-dependent, but with 2-AAF this was clearer in males than females. Ethionine had less clear dose-dependent effects in both males and females. Under these conditions, the minimal effective doses of 2-AAF, 3'-Me-DAB and ethionine, respectively, were 0.0008%, 0.0024% and 0.05% in males and 0.004%, 0.012% and 0.05% in females. The results indicate that these 3 carcinogens had clear dose-dependent effects in the induction of gamma-GT positive foci when given for a short period in the promotive stage and that male rats were more susceptible than females to 2-AAF.

2-Acetylaminofluorene↗
PubMed1981

Age-sex trends of phobic and anxiety symptoms in adolescents.

The prevalence of phobic and anxiety symptoms was investigated in school children and students aged 11-23 years by questionnaire to find age-sex trends of these symptoms. Phobic symptoms were found more prevalent in girls except for fear of talking. Among symptoms which tended to appear in anxiety or under stress, frequency of micturition was more prevalent in boys and the remaining symptoms showed no persistent sex difference. Fear of going out of doors alone and feeling of impending death tended to decrease with age. Symptoms which peaked in adolescence (fear of blushing, fear of being looked at and most anxiety symptoms) occurred at an earlier age in girls than in boys.

Adolescent↗
PubMed1981

Differentiation of the yolk-sac endoderm under the influence of the digestive-tract mesenchyme.

To reveal differentiation potency of yolk-sac endoderm, this tissue from quail embryos was cultured alone or in association with digestive-tract mesenchymes of chick embryos. When yolk-sac endoderm was cultured alone in vitro, the endoderm of the area vitellina differentiated into the yolk-sac parenchyma, but the endoderm of the extraembryonic area pellucida (EEAP) failed to differentiate into yolk-sac parenchyma, and the endoderm of the area vasculosa became necrotic. When endoderm of the area vitellina was cultured in association with digestive-tract mesenchymes, all the endodermal cells developed into yolk-sac parenchymal cells after two days. Later, basophilic cells appeared among them, and differentiated into both mesenchyme-specific epithelia and intestinal-type epithelium with a striated border, and villi were also formed. Goblet cells appeared in all types of recombinations. The endoderm of the EEAP cultured with digestive-tract mesenchymes gave similar results to that of the area vitellina. In contrast, endoderm of the area vasculosa, when cultured with digestive-tract mesenchymes, became necrotic. The present investigation demonstrated that the endoderms of the area vitellina and of the EEAP differ in self-differentiation potency, and that their developmental fates can be modified by the influence of digestive-tract mesenchymes. These endoderms can differentiate into the mesenchyme-specific epithelia, though they often differentiate also into the intestinal-type epithelium.

Animals↗