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Biomedical subjects

Y Eguchi

Publications and source records attributed to Y Eguchi.

At least 217 records · Page 12Linked to original sources
PubMed1983

Thyroid response in fetuses of calorie-restricted pregnant rats given goitrogen.

The growth of fetuses of 50% calorie-restricted (R) rats was retarded by approximately 1 day as compared with that of ad libitum fed control (C) rats. Nevertheless, the thyroid glands in such growth-retarded fetuses developed in proportion to the size of fetuses, as did the thyroid follicular cell height and the follicular diameter. Pregnant rats were treated with 40 mg propylthiouracil (PTU) each day for 2 days and autopsied on the third day in various gestational periods of Days 17-19, 18-20, 19-21, and 20-22. PTU given to C rats on Days 17 and 18 of gestation did not alter the fetal thyroid weight and histology on Day 19. When given on Days 18 and 19, or later, PTU caused a significant increase in the thyroid weight and follicular cell height. However, when given to R rats on Days 18 and 19, PTU did not influence the fetal thyroid. When given on Days 19 and 20, or later, PTU was effective in R rats. Thus, in fetuses of the R rats, the reciprocal relationship between the pituitary and the thyroid appears to be established with a 1-day delay as compared with the C rats, similar to the 1-day retardation in body weight gain.

Animals↗
PubMed1983

An algorithm for the bonding-probability map of nucleic acid secondary structure.

We report a more efficient and well-defined algorithm for predicting a secondary structure of single-stranded nucleic acid from a primary nucleotide sequence. Using this algorithm, one- and two-dimensional bonding-probability maps of 5S rRNA of thermus thermophilus HB8 were calculated. These maps well express the stability of the secondary structure.

Chemical Phenomena↗
PubMed1982

Ontogeny of thyroid peroxidase activity in perinatal rats.

The ontogeny of thyroid peroxidase (TPO) activity was investigated in rat foetuses and neonates. From day 19 to 22 of gestation in intact pregnant rats, the TPO activity in their foetuses increased with foetal age. Following maternal treatment with propylthiouracil (PTU), the TPO activity markedly increased in foetuses on and after day 20 of gestation. The TPO activity in encephalectomized foetuses increased as markedly as that in intact littermates, whereas that in hypophysectomized littermates failed to increase. Newborn rats nursed by mothers treated with PTU had a TPO activity similar to that in controls of untreated mothers. There was also no difference in the TPO activity between hypophysectomized adult females and intact adult ones. These observations show that in foetal rats, TPO activity increases disproportionately to the thyroid weight, but not in newborn and adult rats, and suggest that preferential synthesis of this enzyme occurs in addition to cell hypertrophy during foetal life.

Animals↗
PubMed1981

Hair acid phosphatase: multiple forms, glycoprotein nature and characterization.

Multiple forms of guinea pig hair acid phosphatase and glycoprotein types have been studied by isoelectric focusing and concanavalin-A-Sepharose chromatography. The enzyme appeared under many different forms using electrophoresis. They had similar properties (optimum pH, inhibition studies). The bulk of hair acid phosphatase was bound to concanavalin-A-Sepharose, and approximately 60% of the activity was eluted with alpha-methyl-D-glucoside. This finding strongly indicates that hair phosphatase is a glycoprotein. The enzyme was partially purified by a procedure including DEAE-cellulose and CM-cellulose chromatography, and gel filtration on Sephadex G-100. The enzyme showed similar properties to those of lysosomal acid phosphatase from other organs.

Acid Phosphatase↗
PubMed1980

Ontogeny of the pituitary-thyroid system in fetal rats: observations on the fetal thyroid after maternal treatment with goitrogen.

The critical time of onset of the reciprocal relationship between the pituitary and the thyroid in fetal rats was assessed by the appearance of goiters in fetuses after maternal treatment with goitrogen, propylthiouracil (PTU), on various days of gestation. The assessment was based on changes in the weight and histology of the fetal thyroids. The day following overnight mating was regarded as day 1 of gestation. Pregnant rats were treated with 40 mg PTU each day for two days and autopsied on the third day. The various experimental periods were days 16--18, 17--19, 18--20, 19--21, and 20--22. PTU given to pregnant rats on days 16 and 17 did not cause any change in the fetal thyroids. PTU given on days 17 and 18 caused only a slight increase of fetal "thyroid weight/body weight" ratio. In all other experimental periods (days 18--20, 19--21, and 20--22), PTU induced conspicuous goiters in fetuses, which was reflected by an increased weight of thyroids, an increased height of follicular cells, and a decreased amount of colloid stored in follicles. The results suggest that in fetal rats, the reciprocal relationship between the pituitary and the thyroid is established on approximately days 19--20 of gestation.

Animals↗
PubMed1980

Effect of Cibacron Blue F3GA on phosphoglycerate kinase of Lactobacillus plantarum and phosphoglycerate mutase of Leuconostoc dextranicum.

Blue dextran or Cibacron Blue F3GA has been shown to inhibit yeast phosphoglycerate kinase [EC 2.7.2.3] competitively with respect to ATP (Thompson et al. (1975) Proc. Natl. Acad. Sci. U.S. 72, 663--667; Beissner and Rudolph (1979) J. Biol. Chem. 254, 6273--6277). However, we have found that phosphoglycerate kinase of Lactobacillus plantarum was inhibited by Cibacron Blue F3GA, the blue chromophore of blue dextran, noncompetitively with respect to ATP, but competitively with respect to 3-phosphoglycerate. Further inhibition studies with Cibacron Blue F3GA suggest that one molecule of the dye was bound per molecule of phosphoglycerate kinase at a saturated level of either substrate, but two molecules of the dye were bound per molecule of the kinase with an unsaturated level of either substrate used as a fixed substrate. Furthermore, phosphoglycerate mutase [EC 2.7.5.3] of Leuconostoc dextranicum was also inhibited by Cibacron Blue F3GA competitively with respect to 3-phosphoglycerate and noncompetitively with respect to 2,3-bisphosphoglycerate. These results suggest that the 3-phosphoglycerate-binding site on both phosphoglycerate kinase and phosphoglycerate mutase can interact with Cibacron Blue F3GA.

Adenosine Triphosphate↗
PubMed1980

Compensatory adrenal hypertrophic response in fetuses of calorie-malnourished rats.

Fetuses of ad libitum fed and calorie-restricted rats were unilaterally adrenalectomized on day 19. By day 20 ad libitum fed fetuses exhibited compensatory adrenal hypertrophy, but calorie-restricted fetuses did not. As this may be due to the elevated corticosteroid levels of the calorie-restricted dams, unilateral adrenalectomy was performed on fetuses of control and restricted rats bilaterally adrenalectomized on day 15. Fetuses of restricted and control rats exhibited compensatory hypertrophy. One effect of calorie restriction may be to increase the amount of maternal corticosteroids acting on the fetus.

Adrenal Cortex↗