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S Ohtani

Publications and source records attributed to S Ohtani.

At least 145 records · Page 8Linked to original sources
PubMed1989

[Two cases of age estimation from teeth of burned body using amino acid racemization].

Age estimation of 2 bodies were attempted, using the D/L ratio of aspartic acid in teeth. In case one, the oral cavity had been exposed to air with protruded anterior teeth. Seventeen teeth were extracted and put to examination. From anterior , especially those with darkly incinerated surfaces, estimated ages were far advanced than the actual one. However, from molars whose surfaces were similar in appearance to those of the living teeth, estimations of +/- 3 years error were achieved. In case two, the oral cavity had been closed, stuffed with the tongue and no teeth had been exposed. In all the 15 teeth examined, age estimations of +/- 3 years were achieved. This leads us to conclude that as for the teeth from a burned body, the method of age estimation through racemization is quite possible and valid, provided that the surfaces of the teeth maintained the tint of the living teeth.

Adult↗
PubMed1989

High-performance liquid-chromatographic analysis for serotonin and tryptamine excreted in urine after oral loading with L-tryptophan.

We describe a method used for determining serotonin and tryptamine in urine after oral loading with their precursor amino acid. Several factors affecting prepurification and chromatographic separation of both indoleamines were optimized, including sample extraction and mobile-phase composition. Under optimal conditions, serotonin and tryptamine are extracted from urine samples together with an internal standard, and then they are separated by reversed-phase chromatography followed by native fluorescence detection. The analytical procedure is simple enough to apply to routine analysis and performable at low cost. Sensitivity and selectivity of the method are satisfactory enough to determine urinary serotonin and tryptamine. By pursuing urinary excretion of serotonin and tryptamine after oral loading with L-tryptophan (30 mg per kilogram body weight), our method proves that urinary excretion of both indoleamines increases immediately after loading and reaches a maximum in about 45 min.

Adult↗
PubMed1988

DNA polymerase beta in human thyroid of Graves' disease and thyroid tumors.

We have shown that the level of DNA polymerase beta of rat adrenal cortex is regulated by pituitary trophic hormones and may correlate with their endocrine function. Here we measured DNA polymerase beta activity in human thyroid tissues of various benign and malignant thyroid disorders in order to verify the correlation between DNA polymerase beta activity and endocrine function. In Graves' disease (hyperfunction), the level of DNA polymerase beta per cell was three times higher than in normal thyroid, while in undifferentiated thyroid carcinomas this enzyme level was lower than normal. Furthermore, DNA polymerase beta in the crude extracts of cancer cells showed larger molecular forms, ranging from five to 12S, upon sucrose gradient sedimentation. These observations further support the hypothesis that the activity of DNA polymerase beta correlates, in part, with the functional level of the endocrine organ and with cell differentiation.

Adenoma↗
PubMed1988

Effects of 5-chloro-7-iodo-8-hydroxyquinoline (clioquinol) and nerve growth factor on DNA, RNA and protein syntheses in neonatal rat superior cervical ganglia.

To investigate molecular mechanisms involved in the neurotoxicity of clioquinol (5-chloro-7-iodo-8-hydroxyquinoline), the inhibitory effects of this drug on DNA, RNA and protein syntheses were examined, in relation to the action of nerve growth factor (2.5S NGF). We used an organ culture of neonatal rat superior cervical ganglion (SCG). Ten microM clioquinol inhibited completely DNA and protein syntheses and abolished the stimulatory effect of NGF on RNA synthesis. With regard to the chemical structure of clioquinol, hydroxylation at the 8th carbon of quinoline is essential for the inhibition of DNA, RNA and protein syntheses, and the hydrophobicity of the 8-HQ derivatives is a required property for potent inhibition. Compared with effects of EDTA, alizarine, sodium alizarine sulfate, o-phenanthroline and alpha,alpha'-dipyridyl, the loss of the NGF-induced stimulation of RNA synthesis by clioquinol does not seem to be primarily caused by its metal-chelating property. Clioquinol did not significantly alter the uptake rate of thymidine, uridine and leucine, thereby suggesting that the primary action of clioquinol on inhibition of DNA, RNA and protein syntheses does not relate to uptake of the precursor into SCG. Clioquinol did not significantly alter the degradation of 3H-uridine-labeled RNA. NGF suppressed the degradation of RNA and this suppression was overcome by clioquinol. The release of free uridine from SCG into the culture medium was enhanced by clioquinol and was partially suppressed by NGF. The inhibitory effects of clioquinol were completely prevented by bovine serum albumin (BSA), but not by NGF even at a 5-fold concentration of clioquinol.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Hormonal regulation of DNA polymerase-beta activity in the rat thyroid gland.

Using hypophysectomized rats, it has been shown that DNA polymerase-beta activity in the adrenal gland and testis is largely influenced by pituitary trophic hormones. Sucrose gradient centrifugation of thyroid extracts revealed three peaks of DNA polymerase-beta activity sedimenting at 3.3S, 7.3S and 12S. Of these, hypophysectomy induced a decrease in the 3.3S DNA polymerase-beta, whereas other molecular forms were affected only slightly. DNA polymerase-alpha and -gamma activities were unaffected by hypophysectomy. These changes in DNA polymerase-beta caused by hypophysectomy were reversed by daily i.p. injection of TSH. Furthermore, stimulation of the thyroid by excess TSH induced by the administration of 1-methyl-2-mercaptoimidazole resulted in an increase of all forms of thyroid DNA polymerase-beta. These results show that the level of DNA polymerase is relatively constant after hypophysectomy but that DNA polymerase-beta in the rat thyroid gland is also modulated by TSH mainly through the change of activity of the polymerase-beta which sediments at 3.3S.

Animals↗
PubMed1987

[Change in serum thyroid hormone levels in patients with acute myocardial infarction].

It has been reported that there is a decrease in the serum concentration of thyroid hormones in non-thyroidal illness. In the present study we made serial measurements of serum concentration of thyroid hormones [triiodothyronine (T3), thyroxine (T4), free triiodothyronine (FT3), free thyroxine (FT4), reverse triiodothyronine (rT3)], thyroid stimulating hormone (TSH) and thyroxine binding globulin (TBG) in 10 patients with acute myocardial infarction (AMI, Grade I, according to the classification of Killip & Forrester) during 14 days after onset. In the early phase of AMI, serum T3, T4, FT3 and FT4 levels decreased while rT3 increased. TSH and TBG levels, however, were unchanged. In the patients with a high peak creatine phosphokinase activity (greater than or equal to 400 mU/ml), the decrease in thyroid hormone and increase in serum rT3 levels were greater than in patients with a low peak value (less than 400 mU/ml), suggesting a correlation between severity of AMI and changes in serum thyroid hormone levels. Especially, serum FT3 levels fell below the lower limit of controls within 14 days, with the lowest levels and the rT3 peak on the third day after onset. These data suggest that in AMI peripheral conversion of T4 favours rT3 production and that low levels of serum FT3 and T3 protect the infarcted heart muscle against thyroid hormone action.

Aged↗
PubMed1987

Increase in S-100b protein content in thyroid carcinoma.

S-100b protein was detectable in the soluble fraction of thyroid tissue. The concentration of S-100b protein in thyroid carcinoma tissue was three to five times higher than in normal thyroid tissue and thyroid adenoma. It is, however, not higher in the thyroid tissue of Graves' disease. The increase of S-100b protein concentration was not remarkable in carcinomatous tissue of the stomach and other digestive organs. The calmodulin content in the thyroid carcinoma tissue increased but the increment was low compared to that of S-100b protein. These data suggest that S-100b protein may play a significant role in cell maturation or differentiation.

Adenoma↗
PubMed1987

5-Chloro-7-iodo-8-hydroxyquinoline (clioquinol) inhibits the nerve growth factor-induced stimulation of RNA synthesis in neonatal rat superior cervical ganglion, in vitro--comparison with effects of methylmercuric chloride and 4-hydroxyaminoquinoline-N-oxide.

The inhibitory effects of 5-chloro-7-iodo-8-hydroxy-quinoline (clioquinol), methylmercuric chloride and 4-hydroxyaminoquinoline-N-oxide(4-HAQO) on DNA, RNA and protein syntheses in the neonatal rat superior cervical ganglion (SCG) were studied in relation to the action of mouse 2.5S nerve growth factor (NGF), using organ cultures. RNA and protein syntheses in SCG were stimulated approximately 3- and 2-fold, respectively, by NGF (1 microgram/ml), but the DNA synthesis was only slightly or not at all stimulated. Methylmercuric chloride and 4-HAQO dose-dependently inhibited DNA, RNA and protein syntheses, either in the presence or in the absence of NGF. On the other hand, clioquinol (up to 100 microM) slightly or not at all inhibited RNA synthesis in the absence of NGF; however, it did abolish the NGF-induced stimulation of RNA synthesis in the presence of NGF. The DNA and protein syntheses were dose-dependently inhibited by clioquinol, either in the presence or in the absence of NGF. We conclude from this study that the interaction between clioquinol and the functions of NGF raises the question of a possible toxicity of the drug on specific neurons.

4-Hydroxyaminoquinoline-1-oxide↗
PubMed1987

Effects of pantethine supplementation to diets with different energy cereals on hepatic lipogenesis of laying hens.

Effects on dietary pantethine supplementation on hepatic lipid accumulation and on the activities of lipogenic-related enzymes in the liver were studied in Single Comb White Leghorn laying hens fed isocaloric and isonitrogenous diets containing corn or barley as the carbohydrate source. Addition of 200 ppm pantethine to the corn-soy (CS) basal diet significantly reduced abdominal fat weight, liver triglyceride, as well as total cholesterol and 17 beta-estradiol concentrations in the plasma. Activities of citrate cleavage enzyme (EC 4.1.3.8; CCE) and fatty acid synthetase (FAS) in the liver were significantly reduced when the CS basal diet was supplemented with pantethine, but the activities of nicotinamide adenine dinucleotide phosphate-malate dehydrogenase (EC 1.1.1.40; NADP-MDH) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49; G6PDH), were not significantly affected. However, liver triglyceride, total cholesterol, and 17 beta-estradiol concentrations in plasma as well as the activities of CCE, FAS, and NADP-MDH in liver were significantly lower in laying hens fed the barley-soy (BS) basal diet than in those fed the CS basal diet. Pantethine supplementation to the BS diet failed to show any significant effect on liver triglyceride content and on the hepatic activities of lipogenic-related enzymes. There were no significant differences in liver weight, rate of egg production, and egg weight among dietary treatments. these results suggest that dietary pantethine is effective in reducing the accumulation of liver and abdominal fat in laying hens fed a CS diet.

Animal Nutritional Physiological Phenomena↗
PubMed1986

Immunohistochemical study of neuron-specific enolase and CA 19-9 in pancreatic disorders. The value of neuron-specific enolase as a marker for islet cell and nerve tissue.

Immunohistochemical studies of neuron-specific enolase were performed on pancreatic tissues from patients with insulinoma, nonfunctioning islet cell tumor, chronic pancreatitis, and pancreatic adenocarcinoma, and from 5 normal patients. The concentration of neuron-specific enolase was also measured in the sera of patients and in the pancreatic tissue, and the tissues were stained for carbohydrate antigen 19-9 by immunohistochemical techniques. Neuron-specific enolase was localized in nerve fibers, normal islet cells, and islet cell tumors; its concentration was elevated only in the tissue of islet cell tumors and in serum from patients with insulinoma. In the pancreatic tissue of pancreatitis or pancreatic adenocarcinoma, various changes in acini and islets were present. The altered islets stained clearly for neuron-specific enolase and could easily be distinguished from altered, unstained acini in cases of pancreatitis or pancreatic adenocarcinoma. Islets in the pancreatic tissue remained intact with various morphologic changes, although acini had degenerated severely. Carbohydrate antigen 19-9 was localized in all the carcinoma cells in the pancreatic tissue and in some of the normal pancreatic ducts. No cells were simultaneously immunostained by anti-neuron-specific enolase and anti-carbohydrate antigen 19-9 antibodies. Thus, neuron-specific enolase is a good marker for islet cell tumor, and is valuable for examining islets in pancreas with various disorders both alone and in combination with other tumor markers.

Adenocarcinoma↗
PubMed1986

Effect of calmodulin inhibitors on thyroid hormone secretion.

The effect of calmodulin inhibitors, N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide (W-7) and trifluoperazine, on TSH-induced thyroid hormone secretion from rat thyroid was examined in vivo and in vitro. The ip administration of 5 mg W-7 to the rat inhibited T4 and T3 secretion from rat thyroids at 2, 3, and 4 h after the ip injection of 2 IU TSH, and so did the ip injection of trifluoperazine at 3 and 4 h. However, the ip injection of N-(6-aminohexyl)-1-naphthalene sulfonamide as a control substance did not show any significant inhibition of T4 and T3 release. To identify the site of action of calmodulin, the effect of W-7 on (Bu)2cAMP-induced thyroid hormone secretion was tested in vitro. One hundred micromolar W-7 completely inhibited T4 release from the rat thyroid when it was enhanced by TSH or (Bu)2cAMP, suggesting that the inhibitory effect of W-7 is subsequent to cAMP formation. These results suggest that calmodulin may play a role in thyroid hormone secretion from the thyroid, acting beyond cAMP formation.

Animals↗
PubMed1986

Enolase subunits in patients with neuroendocrine tumors.

Concentrations of the alpha-, beta-, and gamma-subunits of enolase in surgically resected tumors and serum obtained from patients with various endocrine tumors were measured by a sensitive enzyme immunoassay system. Tissue concentrations of the gamma-subunit were significantly elevated in patients with neuroendocrine tumors concurrent with high concentrations of the gamma-subunit in their serum, which fell to normal in 90% of those who underwent tumor resection. Immunohistochemical analysis revealed that considerable amounts of the gamma-subunit were contained specifically in these tumors. These results indicate that the gamma-subunit of enolase is a useful marker for diagnosing and monitoring patients with neuroendocrine tumors.

Adult↗