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Biomedical subjects

Y Endo

Publications and source records attributed to Y Endo.

At least 775 records · Page 43Linked to original sources
PubMed1980

In vivo deacetylation of N-acetyl amino acids by kidney acylases in mice and rats. A possible role of acylase system in mammalian kidneys.

Deacetylations of N-acetylhistidine and N-acetyltryptophan were examined in vivo by their administration to mice and rats. N-Acetylhistidine accumulated preferentially in the kidney and was converted to histidine effectively by acylase I. Similar deacetylation of N-acetyltryptophan by acylase III was also observed. Acylase I and III activities in mouse kidney increased in parallel remarkably at the period of weaning. A hypothesis that the acylase system in mammalian kidneys is a mechanism acquired to utilize amino acids from exogenous and endogenous acyl derivatives including those derived from protein hydrolysis was offered.

Aging↗
PubMed1980

Identification of carcinoembryonic antigen in the C-cell of the normal thyroid.

Carcinoembryonic antigen (CEA) activity was confirmed in the C-cell of the normal thyroid by immunohistochemical techniques. This suggests that CEA production in medullary carcinoma of the thyroid is not initiated by carcinogenesis, but reflects a function of the normal C-cell. It is not yet clear whether CEA production in the C-cell may be influenced by carcinogenesis. The C-cell is the first APUD cell that was confirmed to have CEA activity.

APUD Cells↗
PubMed1980

IgA nephropathy with subendothelial deposits.

IgA nephropathy with subendothelial deposits in the capillary walls of the glomeruli (IgA type 2) was compared histometrically and clinically with IgA nephropathy without subendothelial deposits (IgA type 1) and membranoproliferative glomerulonephritis with subendothelial deposits (MPGN). Study cases consisted of 32 biopsies from 26 patients of IgA type 1, 25 biopsies from 20 patients of IgA type 2 and 31 biopsies from 27 patients of MPGN. Histological changes of the glomeruli consisted of an increase in the mesangial matrix and hypercellularity in the mesangium in both types of IgA nephropathy, and the degree of the changes was a little higher in IgA type 2 than in IgA type 1 (0.02 < P < 0.05). Mesangial changes of MPGN were marked as compared with IgA type 1 and IgA type 2 (P < 0.001). Histometry of the mesangium on the cases followed up showed that the degree of mesangial thickening increased with lapse of time in IgA type 2 and MPGN, whereas it remained unchanged up to 13 years in IgA type 1. Proteinuria tended to be mild in IgA type 1, moderate in IgA type 2, and marked in MPGN. The impairment of renal function was observed in 21.9% of IgA type 1, in 36.0% of IgA type 2 and in 58.1% of MPGN. IgA type 2 has been shown to be pathologically and clinically intermediate between IgA type 1 and MPGN. These results suggest that there is a clinicopathological overlap between IgA nephropathy and MPGN with IgA deposition.

Biopsy↗
PubMed1980

Inhibitory effect of acpuncture on the vibration-induced finger flexion reflex in man.

The effect of acupuncture on the tonic finger flexion reflex caused by mechanical vibration of the index finger was studied in healthy man. The volar side of the index finger was tapped by a vibrator (100 Hz), while flexion forces were recorded. A silver needle inserted into the acupuncture point (Wai-Kuan) inhibited the vibration-induced finger flexion reflex. In this study, the inhibitory effect of acupuncture on the reflex contraction, rather than pain sensation and analgesia, was demonstrated.

Acupuncture Therapy↗
PubMed1980

A simple determination of serotonin, 5-hydroxyindoleacetic acid and 5-hydroxytryptophan decarboxylase activity in rat brain areas and parallel correlation among the levels.

We devised a simple method for the separation of serotonin (5HT) and 5-hydroxyindoleacetic acid (5HIAA) using small P-cellulose and DEAE-Sephadex columns, respectively. Both substances were estimated fluorometrically by the reaction with o-phthalaldehyde (OPA). In this method, some known interfering substances in addition to many primary amines and amino acids were separated from 5HT and 5HIAA. The recoveries of 5HT and 5HIAA were 80 and 71%, respectively. The fluorescence intensities of 30 pmol of 5HT and 15 pmol of 5HIAA were about twice over the reagent blank. The complete separation of 5-hydroxytryptophan (5HTP) from 5HT made it possible to determine 5HTP decarboxylase activity in rat brain areas without using an isotope-labeled substrate. The method allows for quantitation of the enzyme activity in mg amounts of the brain tissues. The activities in discrete areas were in good parallel with the 5HT contents, except for the striatum. The levels of 5HIAA were also much in parallel with those of 5HT.

Animals↗
PubMed1980

alpha-Fetoprotein and other serum proteins synthesized by endodermal sinus tumor transplanted into nude mice.

The human yolk sac is said to synthesize not only alpha-fetoprotein but also other serum proteins, i.e., albumin, prealbumin, alpha 1-antitrypsin, and transferrin. Two endodermal sinus tumors (yolk sac tumors) were successfully transplanted into athymic nude mice. Concentration of these human serum proteins in the sera of the nude mice and tumor extracts was determined quantitatively by electro-immunodiffusion and radioimmunoassay. alpha-Fetoprotein and albumin were detected in one case, and alpha 1-antitrypsin and alpha-fetoprotein in the other. In the former case, the amount of alpha-fetoprotein synthesized was larger than that of albumin, whereas the amount of alpha-fetoprotein was smaller than that of alpha 1-antitrypsin in the latter. It is tempting to consider that human endodermal sinus tumors simulate the human yolk sac functionally, but the pattern of protein synthesis may differ from case to case.

Animals↗
PubMed1980

Effect of phorbol esters and hormones on rat hepatoma cells producing alpha-fetoprotein.

Effect of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on rat AH66 hepatoma cells was studied with a reference to that of insulin and the epidermal growth factor (EGF). In a short term cell incubation, TPA and EGF caused an approximately 2-fold increase in the production of alpha-fetoprotein (AFP) and other acid-precipitable materials, while the same concentration of insulin brought a 3-fold increase. In a long term culture using a low serum medium, TPA as well as insulin and EGF caused remarkable proliferation of AH66 cells, but the increase in cell number was not accompanied by a proportional increase in the levels of AFP of the culture media. These biological effects of TPA, insulin and EGF appeared to resemble each other, and subsequent hormone binding studies showed that TPA inhibited 125I-EGF binding to its membrane receptors without affecting 125I-insulin binding. Scatchard analysis of TPA effect on EGF binding indicated that TPA altered the affinity of the membrane receptors for EGF without changing the total number of available receptors per cell. From these data, it is suggested that some of the biological effects of TPA on AH66 cells may result from alterations in the functions of cell membrane.

Animals↗
PubMed1980

Alpha-fetoprotein in infantile obstructive jaundice in comparison with the normal ranges.

In an attempt to study the diagnostic value of alpha-fetoprotein (AFP), serum AFP concentrations were measured by radioimmunoassay in 34 neonates and infants with obstructive hepatobiliary diseases and the results were compared with the normal ranges of AFP at this age. Eighteen of 24 infants with biliary atresia and four of six infants with neonatal hepatitis had raised AFP values. In only one of four infants with choledochal cyst, did the AFP value exceed the normal range. In 10 older children with this lesion, AFP was normal. Serum AFP concentrations in biliary atresia did not correlate with the serum bilirubin, s-GOT, s-GPT, anatomic type of the lesion or postoperative bile flow. From these observations, it would appear that the elevation of AFP in infantile cholestasis is unrelated to underlying diseases except in case of alpha 1-antitrypsin deficiency. Serum AFP concentrations in neonates with physiological jaundice, were seldom elevated, and showed a good correlation with serum levels of total bilirubin. Possible mechanisms causing this elevation of AFP may be different from those involved in infantile cholestasis.

Aging↗
PubMed1979

Elevation of histamine levels in rat and mouse tissues by the deacetylation of administered N-acetylhistamine.

N-Acetylhistamine administered to mice and rats (200-800 mg/kg, i.p.) elevated tissue histamine levels to a considerable extent. N-Acetylhistamine was more potent to elevate histamine than was histidine, a precursor amino acid of histamine. From the present results and the distribution of N-acetylhistamine deacetylase in tissues, it could be concluded that the elevation of histamine was due to the deacetylation of N-acetylhistamine. In addition, a slight but significant amount of N-acetylhistamine was found in tissues of normal rats. The physiological role of the deacetylation of N-acetylhistamine is discussed on the basis of these results.

Animals↗
PubMed1979

[Study on enzyme immunoassays for the measurement of thyroglobulin and anti-thyroglobulin autoantibody in human serum (author's transl)].

Enzyme-linked sandwich immunoassays for the measurement of thyroglobulin and anti-thyroglobulin autoantibody in human serum using silicone rod and beta-D-galactosidase were studied. These methods showed excellent results in specificity, sensitivity, precision and clinical application. 1) A method using silicone rod coated with rabbit (anti-human thyroglobulin) immunoglobulin G and rabbit (anti-human thyroglobulin) monovalent fragment of immunoglobulin G (Fab') conjugated with beta-D-galactosidase was developed for the measurement of circulating thyroglobulin. The sensitivity of the assay with as little as 2 microliter of serum was 10.7 amoles/tube corresponding to 3.5 ng/ml of serum, which was equal to or rather higher than that of radioimmunoassay. The correlation coefficient between values determined by the present assay and a double-antibody radioimmunoassay was 0.99 (n = 63, p less than 0.001). Circulating thyroglobulin was detectable in 90% of 146 normal subjects, the concentration being 13.3 +/- 10.3 ng/ml (mean +/- S.D.). Interference of anti-thyroglobulin autoantibody with the assay for thyroglobulin was smaller than that in radioimmunoassay. 2) Another method using human thyroglobulin conjugated with beta-D-galactosidase and silicone rod coated with human thyroglobulin was developed for the measurement of circulating (anti-human thyroglobulin) autoantibody. The sensitivity of the assay with as little as 5 microliter of serum was 7 fmoles/tube corresponding to 220 ng/ml of serum, which was equal to or rather higher than that of radioimmunoassay. The highly significant correlation was observed between the concentrations of anti-thyroglobulin autoantibody determined by the present assay and a radioimmunoassay (r = 0.80, n = 74, p less than 0.001) and also between those by the present assay and those by tanned red cell hemagglutination (r = 0.78, n = 199, p less than 0.001). No effect of thyroglobulin on the present assay was observed unless the ratio of the amount of thyroglobulin to that of (anti-human thyroglobulin) immunoglobulin G was higher than a tenth.

Autoantibodies↗