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Biomedical subjects

T Endo

Publications and source records attributed to T Endo.

At least 1,135 records · Page 63Linked to original sources

Conformation of cobrotoxin in aqueous solution as studied by nuclear magnetic resonance.

The 270-MHz proton NMR spectra of cobrotoxin from Naja naja atra were observed in 2H2O solution. The pKa value (5.93) of His-32 is slightly lower than the pKa value (6.65) of the reference model of N-acetylhistidine methylamide, because of the electrostatic interaction with Arg-33 and Asp-31. The pKa value (5.3--5.4) of His-4 is appreciably low, because of the interaction with the positively charged guanidino group possibly of Arg-59. The hydrogen-deuterium exchange rates in 2H2O solution were measured of cobrotoxin and imidazole-bearing models. The second-order rate constants of N-acetylhistidine methylamide, N-acetylhistidine and imidazole acetic acid satisfy the Brønsted relation. With reference to this Brønsted relation, the imidazole ring of His-32 is confirmed to be exposed. The imidazole ring of His-4 is also exposed and the exchange rate is excessively promoted by the presence possibly of Arg-59 in the proximity. All the methyl proton resonances are assigned to amino-acid types, by conventional double-resonance method and more effectively by the spin-echo double-resonance method. Eight methyl proton resonances are identified as due to the gamma and/or delta-methyl groups of Val-46, Leu-1, Ile-50 and Ile-52 residues. The proximity of aromatic ring protons and methyl protons is elucidated by the analyses of nulcear Overhauser effect enhancements. The aromatic proton resonances of Trp-29 are affected by the ionizable groups of Asp-31, His-32 and Tyr-35. The methyl groups of Ile-50 are in the proximity to the aromatic ring of Trp-29 and the methyl groups of Ile-52 are in the proximity to Tyr-25. The highest-field methyl proton resonance is due to a threonine residue in the proximity to His-4. The appreciable temperature-dependent chemical shift of this methyl proton resonance suggests a temperature-dependent local conformational equilibrium around the His-4 residue of the first loop of the cobrotoxin molecule.

Amino Acid Sequence↗

Re-evaluation of a possible high incidence of hypertension in hypothyroid patients.

In an attempt to re-evaluate a possible high incidence of hypertension in hypothyroid patients, blood pressure was measured in 38 slightly hypothyroid patients, in 17 moderate hypothyroid patients, and in 26 severe hypothyroid patients. The data were then compared with the findings in 73 known euthyroid subjects and in 1,601 possibly euthyroid subjects. Blood pressure and incidence of hypertension increased progressively with age in known euthyroid subjects and in possibly euthyroid subjects. Similarly, blood pressure increased progressively with age in slight and moderate hypothyroid patients, but the incidence of hypertension was high in the sixth decade in slightly hypothyroid patients for some unknown reason. In contrast, blood pressure and the incidence of hypertension were low in the fifth and sixth decades in severe hypothyroid patients. This low blood pressure was elevated slightly when Sv1 + Rv5 and C/T were shifted toward normal by T4 treatment for 3 to 4 months. It is suggested that the hypothyroid state does not accelerate the development of hypertension.

Adult↗

Age-related changes in endocrine and renal function in patients with essential hypertension.

Endocrine and renal functions were studied in 149 patients with essential hypertension by measuring plasma electrolytes, renin activity, creatinine and aldoserone, as well as the urinary excretion of creatinine and sodium chloride, before and during treatment for hypertension. Half of the patients responded to trichlormethiazide (thiazide-responsive group) but the other half did not (thiazide-unresponsive group). Systolic and diastolic blood pressures increased progressively uith age in the thiazide-unresponsive group, but were lower and did not progress with age in the thiazide-responsive group. There was no consistent difference in plasma renin activity between the thiazide-responsive and the thiazide-unresponsive groups. The fluctuation of plasma renin activity in response to an excess of sodium chloride or to thiazide treatment was reduced progressively with age. Creatinine clearance decreased and the blood urea nitrogen level increased with age. The age-related decrease of plasma renin activity is discussed on the light of the age-related impairment in the ability of the kidney to excrete sodium and water.

Adult↗

Hyperthyroidism in the elderly.

In 65 elderly hyperthyroid patients (age range 50-78 years), sex differences, signs and symptoms and thyroid function were studied and the data were compared with those on 48 young hyperthyroid patients (age range 20-29 years). The incidence of hyperthyroidism was 3.5 times higher in females than in males among the young patients, whereas it was approximately equal in males and females among the elderly patients. Signs and symptoms conformed with the textbook description in the young subjects but not in the elderly ones. Measurements of serum triiodothyronine (T3) and thyroxine (T4) proved useful in preventing false diagnoses in elderly patients with atypical symptoms. In some elderly subjects with marginal increases of serum T3 and T4 concentrations, measurement of serum thyroid-stimulating hormone (TSH) after administration of thyrotropin-releasing hormone (TRH) was required to achieve an accurate diagnosis. Serum T3 and T4 levels and the thyroidal uptake of radioiodine were slightly but not significantly lower in the elderly than in the young patients. A high titer of circulating thyroid auto-antibody in the elderly may be related to this slight decrease in thyroid function. Serum T3 levels were significantly lower in the elderly than in the young subjects; this suggests impairment of peripheral monodeiodination of T4. Any abnormal serum levels of T4, T3, and TSH before and after administration of TRH could easily be restored to normal by treatment with antithyroid drugs in the elderly patients.

Adult↗

Bile acid metabolism in benign recurrent intrahepatic cholestasis. Comparative studies on the icteric and anicteric phases of a single case.

Bile acid compositions in the serum, urine, bile, and feces were examined in a typical case of benign recurrent intrahepatic cholestasis for a period of 3 yr. The serum cholesterol level remained almost constant. The serum and urinary levels of total bile acids increased markedly during the icteric phase but returned to normal toward the anicteric phase. Daily fecal excretion of bile acids in the anicteric phase was about three times the normal value. Bile acids in the bile and feces, and in the serum and urine, mainly consisted of chenodeoxycholic and cholic acids, with little deoxycholic acid even in the anicteric phase. Scarcely any coprostanol was found in the feces. These observations suggest that metabolism by intestinal bacteria was altered in this patient. The ratio of cholic acid/chenodeoxycholic acid in the serum was above 2.0 in the icteric phase but was reduced to 0.9 in the anicteric phase. At least three unusual bile acids, designated as peak 7a, 11, and 13, were detected in the feces. The amount of bile acid in peak 7a reached about 10% of the total in the anicteric phase.

Adult↗

[A statistical survey of autopsy cases of malignant goiter (author's transl)].

A total of 747 cases of malignant neoplasms of the thyroid reported in the "Annual of the Pathological Autopsy Cases in Japan" during the past 5 years (1969 approximately 1973) were reviewed and statistically analysed. Histological diagnosis in this series were papillary carcinoma in 323 cases (51.8%), follicular carcinoma in 143 cases (22.9%) and anaplastic carcinoma in 102 cases (16.3%). The average age of patients at autopsy was 58 years for papillary carcinoma cases, 62.4 years for follicular carcinoma cases and 61.7 years for anaplastic carcinoma cases. The incidence of metastatsis to lymph nodes and to organs was 47.3% and 51.5%, respectively in cases of follicular carcinoma and 73.3% and 98.0%, respectively in cases of anaplastic carcinoma. Autopsy revealed an otherwise unnoticed thyroid cancer in 457 cases, which accounted for 61.2% of the entire autopsy cases of malignancy of this organ. A so-called multiple cancer, i.e. the concurrence of carcinomas in the thyroid gland and other organs, was seen in 239 cases (32.3%).

Adenocarcinoma↗