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Biomedical subjects

T Itatsu

Publications and source records attributed to T Itatsu.

8 recordsLinked to original sources
PubMed1989

Neurohypophyseal function in postpartum hypopituitarism: impaired plasma vasopressin response to osmotic stimuli.

We studied neurohypophyseal function in 12 women with postpartum hypopituitarism (Sheehan's syndrome) by measuring plasma arginine vasopressin concentrations during 5% hypertonic saline infusions. All patients had a history of obstetric shock or massive bleeding, and were receiving cortisol and/or L-T4 replacement therapy. None had any symptoms of diabetes insipidus. The mean basal plasma vasopressin level in the patients [0.6 +/- 0.1 (+/- SE) pmol/L] was significantly lower (P less than 0.01) than that in normal adults (2.5 +/- 0.5 pmol/L; n = 12), whereas mean plasma osmolality values were similar in the two groups. During hypertonic saline infusion, the 10 hypopituitary patients had varying degrees of subnormal arginine vasopressin responses to the increase in plasma osmolality. Urine-concentrating ability after dehydration also was lower in the patients, although overt polyuria was absent at the time of this study. These results indicate that the osmoregulation of arginine vasopressin secretion is frequently impaired in postpartum hypopituitarism, suggesting neurohypophyseal damage.

Adult↗
PubMed1989

Association of HLA antigen and restriction fragment length polymorphism of T cell receptor beta-chain gene with Graves' disease and Hashimoto's thyroiditis.

HLA antigen phenotypes and BglII restriction fragment length polymorphism of T cell receptor beta-chain (TCR beta) gene were analyzed in 61 patients with Graves' disease and 50 patients with Hashimoto's thyroiditis. The antigen frequency of HLA-Bw46 in both Graves' disease (23.0%) and Hashimoto's thyroiditis (24.0%) was significantly higher than that in normal population (8.0%), with relative risks (RR) of 3.45 [corrected P (Pc) less than 0.009] and 3.66 (Pc less than 0.02), respectively. Significantly increased frequency of HLA-B51 antigen was also found in Hashimoto's thyroiditis (40.0% vs. 16.3% in controls; RR, 3.42; Pc less than 0.002). Hybridization of BglII-digested DNA with TCR beta probe revealed two alleles of 9.3 and 8.6 kilobases. The allele frequency of 8.6 kilobases in Graves' disease (79%) and Hashimoto's thyroiditis (76%) was significantly higher (P less than 0.01 and P less than 0.05, respectively) than that in controls (64%). The frequency of homozygous state 8.6/8.6 was significantly increased in both Graves' disease (62%) and Hashimoto's thyroiditis (60%) over that in controls (39%); the RR of 8.6/8.6 in Graves' disease and Hashimoto's thyroiditis were 2.55 (P less than 0.01) and 2.31 (P less than 0.05), respectively. These results indicate that in Japanese subjects at least two loci are involved in the susceptibility to Graves' disease and Hashimoto's thyroiditis, one related to HLA and another to TCR beta.

Alleles↗
PubMed1988

Association of HLA-DR phenotypes and T-lymphocyte-receptor beta-chain-region RFLP with IDDM in Japanese.

Fifty Japanese patients with insulin-dependent diabetes mellitus (IDDM) and 94 normal subjects were genotyped for BglII restriction-fragment-length polymorphism (RFLP) of the T-lymphocyte-receptor beta-chain (TLR beta)-region gene and analyzed in relation to HLA-DR phenotypes. The antigen frequencies of DR4 and DR9 in the IDDM population were significantly higher than those in the normal population, with relative risks of 1.87 (P less than .02) and 2.42 (P less than .01), respectively. Hybridization of digested DNA with the TLR beta probe revealed two alleles of 9.3 and 8.6 kilobases (kb). The allele frequency of 8.6 kb in patients with IDDM (79%) was significantly (P less than .05) higher than that in normal subjects (64%). When TLR beta-region RFLP in IDDM was further analyzed with respect to the HLA-DR phenotypes, the frequency of 8.6 kb was significantly increased in patients with DR4 but not DR9 (DR4/X) and those with DR9 but not DR4 (DR9/X) compared with the frequency found in normal subjects (P less than .05); the relative risks of 8.6 kb in DR4/X and DR9/X were 2.77 and 4.98, respectively. Although the frequencies of HLA-DR phenotypes and of TLR beta-region RFLP in IDDM and normal subjects were apparently different from those reported for Caucasians, this population-association study indicates that in the Japanese, genes conferring susceptibility to IDDM exist near or at the HLA-DR and the TLR beta loci, as has been demonstrated in Caucasians.

Adolescent↗
PubMed1979

The release and metabolism of pancreatic hormones after major hepatectomy in the dog.

Major hepatectomy in the dog induced a 50% decrease in peripheral serum glucose, a 11-fold increase in portal plasma glucagon and a 36-fold increase in the portal glucagon/insulin ratio 3 hr after operation. Peripheral serum glucose levels were inversely correlated to the logarithmic value of portal plasma glucagon (r = -0.50, p less than 0.01) and that of the portal glucagon/insulin ratio (r = -0.85, p less than 0.01) for 1-6 hr after operation. The ratio of peripheral to portal plasma glucagon was also inversely correlated to the logarithmic value of portal plasma glucagon (r = -0.59, p less than 0.01). In case of glucose infusion, plasma glucagon levels were not elevated after major hepatectomy. The data suggest that glucose deficiency after major hepatectomy in the dog may cause hyperglucagonemia with an enhanced glucagon requirement.

Animals↗
PubMed1977

Effect of somatostatin on neurotensin-induced glucagon release and hyperglycemia.

Administration of neurotensin to dogs resulted in rises in circulating blood glucose, glucagon and insulin levels, the rise in glucagon being more pronounced than that in insulin. Infusion of somatostatin along with neurotensin suppressed glucagon and insulin responses to neurotensin and prevented the rise in blood glucose levels. These results suggest that the hyperglycemia seen after neurotensin is due to neurotensin stimulation of glucagon release over insulin release.

Animals↗