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Biomedical subjects

Y Eguchi

Publications and source records attributed to Y Eguchi.

At least 235 records · Page 13Linked to original sources
PubMed1980

Serum ferritin concentration and isoferrtin patterns detected by immunoradiometric assay.

Two-site immunoradiometric assay for serum ferritin was developed by anti-human liver ferritin antiserum applied on polyvinyl V-bottom microtiter plates. The coefficient of variation was 4.4-5.9% of liver ferritin dissolved in 1/4 diluted human serum at a concentration of 0.625-125 ng/ml. The lowest concentration (0.625 ng/ml) was statistically distinguishable from the background by Student's t test (p < 0.05). Isoferritin patterns of serum ferritin and tissue ferritins were examined by the combination of gel isoelectric focussing and 2-site immunoradiometric assay in order to explore any similarities in pIs within these ferritins. Although serum ferritin had wide range of pIs, its basic isomers corresponded well to those of liver and spleen ferritin. Geometric means and their 95% confidence limits in serum ferritin concentration were 70 ng/ml and 12-411 ng/ml, respectively, in sera of 205 healthy males (16-25 years), and 12 ng/ml and 1-211 ng/ml, respectively, in 421 healthy females (16-59 years).

Adolescent↗
PubMed1979

Light- and electron-microscopic studies on the gastric parietal cells in perinatal rats. Effects of fetal and neonatal oral administration of milk.

Perinatal changes of the gastric parietal cells were studied under normal and various experimental conditions. Histologic examination revealed that the parietal cells appeared markedly increased in number from late fetal to early neonatal days. When premature newborn rats were delivered by cesarean section and were nursed by foster mothers for 1 or 2 days, the degree of increase of these cells reached nearly that in the normal neonates. On the other hand, in fetuses retained in utero 1 day beyond the normal gestation, these cells appeared not increased in number. When these postmature fetuses were delivered, the parietal cells turned to increase in number in a degree similar to that in the normal neonates. Milk given to the premature newborn rats caused 6 h later a marked increase in the number of the parietal cells. Milk given to fetuses in utero also caused an increase of these cells. The results suggest that the development of the parietal cells in perinatal rats is accelerated by the intake of milk and that the fetal parietal cells are ready to respond to milk given at least 1 day before birth.

Age Factors↗
PubMed1978

Changes in placental permeability to corticosterone and estradiol-17beta toward the end of gestation in the rat.

Radioactivity in the fetal plasma 1 h after maternal injection of 14C-4-corticosterone or 14C-4-estradiol-17 beta on day 21 of gestation was markedly higher than that 1 h after injection on day 22. Radioactivity in the maternal plasma was not different on these 2 days. The results suggest that the placental permeability to steroids from the mother to the fetus declines toward the end of gestation in the rat.

Animals↗
PubMed1978

Development of the fetal pituitary-testicular system based on the observation of Leydig cells in encephalectomized, hypophysectomized and control fetal rats.

The time of onset of brain regulation of the pituitary-Leydig cell system in fetal rats was assessed by fetal encephalectomy, which allowed the pituitary to persist in situ. The effects of encephalectomy were compared with those of fetal hypophysectomy (surgical decapitation). The parameter for interpretation of these effects was the collective volume of Leydig cells, measured by the method of Chalkley ('43). The normal increase in the collective volume of Leydig cells in fetuses encephalectomized on day 17 of gestation and autopsied on day 18 was not retarded, whereas that in decapitated fetuses of the same age was retarded. In all other one-day experimental periods (day 18-19, 19-20, 20-21, and 21-22), the increase in volume was retarded to approximately the same extent in encephalectomized as in decapitated fetuses. The collective volume of Leydig cells continued to increase to some extent without the brain until day 20, after which it ceased to increase. The results suggest that in fetal rats, the brain control of the pituitary-Leydig cell system begins to operate from day 18 of gestation, when the day following overnight mating was designated as day 1 of gestation.

Animals↗
PubMed1977

Granularity of cells in the juxtaglomerular apparatus in fetal rats after maternal nephrectomy or fetal unilateral nephrectomy.

Granular cell indices (GCI: Dunihue and Robertson, '57) in kidneys of fetal rats one day after maternal nephrectomy of fetal unilateral nephrectomy on day 21 of gestation were determined by examining sections stained with Bowie's technique. Maternal nephrectomy induced an extreme increase of GCI in fetal kidneys with increased granularity of cells in the juxtaglomerular apparatus. Fetal unilateral nephrectomy did not cause any significant change.

Animals↗
PubMed1977

Rise of plasma corticosterone concentrations in rats immediately before and after birth and in fetal rats after the ligation of maternal uterine blood vessels or of the umbilical cord.

Just before normal vaginal delivery the plasma corticosterone concentration (PCC) in fetal rats increased markedly compared with that on day 22 of gestation. The PCC was elevated 2 h after birth and then declined until 12 h after birth, when it approached the level found on day 22 of gestation. Similarly, in premature newborn rats obtained by cesarean delivery on days 21 and 22 of gestation, the PCC increased 2 to 4 h after delivery and then declined. The PCC in 22-day-old fetal rats, 30 min after ligation of the maternal blood vessels running along a uterine horn, rose markedly compared with that in fetuses in the contralateral intact horn. A similar increase in PCC was not observed in either decapitated or encephalectomized fetuses, but observed in fetuses whose umbilical cords were ligated. The rise in fetal PCC after ligation of uterine blood vessels and of umbilical cords was considerably higher than that observed after various stresses reported by other investigators and also higher than that found 60 min after maternal adrenalectomy. The rise in PCC just before and just after birth and after the ligation should not be considered as the result of stress, parturition or ligation, but may be a result of the response to other factors.

Animals↗
PubMed1976

Purification and characterization of methioninase from Pseudomonas putida.

Methioninase of Pseudomonas putida was purified to homogeneity, as judged by polyacrylamide gel electrophoresis, with a specific activity 270-fold higher than that of the crude extract. 1. The purified enzyme had an S20,w of 8.37, a molecular weight of 160,000, and an isoelectric point of 5.6. 2. A break in the Arrhenius plot was observed at 40 degrees and the activation energies below and above this temperature were 15.5 and 2.97 kcal per mole, respectively. 3. In addition to L-methionine, various S-substituted derivatives of homocysteine and cysteine could serve as substrates. D-Methionine, 2-oxo-4-methylthiobutanoate, and related non sulfur-containing amino acids were inert. Equimolar formation of alpha-ketobutyrate and CH3SH was observed with methionine as a substrate. 4. In addition to the protein peak at 278 nm, two absorption maxima were observed at 345 and 430 nm at pH 7.5. Hydroxylamine removed the enzyme-bound pyridoxal phosphate, resulting in almost complete resolution with the concomitant disappearance of both peaks. Reconstruction of the treated enzyme could be achieved by addition of the cofactor; the Km value was calculated to be 0.37 muM. 5. The reported purified enzyme should be designated as L-methionine methanethiollyase (deaminating).

Calorimetry↗