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Biomedical subjects

I Komiya

Publications and source records attributed to I Komiya.

At least 127 records · Page 7Linked to original sources
PubMed1981

A screening test to identify aldosterone-producing adenoma by measuring plasma renin activity. Results in hypertensive patients.

In an attempt to devise a screening test for aldosterone-producing adenoma (APA) among hypertensive patients, the serum sodium and potassium levels, plasma renin activity (PRA), plasma aldosterone concentration, and aldosterone-PRA ratio were measured in 348 patients with hypertension. Nine patients with a substantially elevated aldosterone-PRA ratio were selected and hospitalized for further investigations. All nine patients were then recognized by scintigraphy with labeled cholesterol, venography, and surgical excision as having APA. The serum concentration of potassium was subnormal in three of nine patients with APA. In patients with APA, administration of diuretics and salt restriction significantly elevated PRA. However, even under notable diurnal and day-to-day variations of plasma aldosterone concentrations, the aldosterone-PRA ratio was always elevated inappropriately (more than 400) in patients with APA. In contrast, after administration of diuretics, both the PRA and aldosterone levels increased significantly in patients with essential hypertension, but the aldosterone-PRA ratio was less than 200. Since the renin-angiotensin system seems to be a major factor controlling aldosterone secretion in normal subjects, it is suggested that an elevation of aldosterone-PRA ratio more than 400 is a useful screening tool for the prediction of APA among hypertensive patients.

Adenoma↗
PubMed1980

Mechanism of renal distribution of aminoglycoside antibotics.

The renal accumulation of dibekacin, one of the aminoglycoside antibiotics, was pharmacokinetically analyzed and the mechanism of the renal accumulation of these antibiotics was investigated. The remaining amounts of dibekacin in the kidneys were adequately expressed by the bi-exponential equation. There was no possibility of a covalent bond between dibekacin and the renal tissue components. The renal accumulation of the aminoglycoside antibiotics was explained in terms of the two successive processes, renal tubular reabsorption and electrostatic interaction between these antibiotics and the tissue components. In other words, these antibiotics were reabsorbed at the renal tubules and transported into renal tubular epithelial cells and bound to the tissue components by electrostatic force. The electrostatic interaction also played an important role in increasing the acute toxicities of aminoglycoside antibiotics.

Aminoglycosides↗
PubMed1979

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↗
PubMed1979

Concurrent hypersecretion of aldosterone and cortisol from the adrenal cortical adenoma.

Hypertension, hypokalemia, suppressed plasma renin activity and increased plasma aldosterone were found in a middle-aged woman. Following removal of the tumor in the left adrenal gland these abnormalities disappeared. Concurrently, however, the plasma cortisol level did not show normal diurnal change, although the value at 6 A.M. was within the normal range. Administration of 2 mg dexamethasone failed to depress the plasma cortisol level and urinary 17-OHCS concentrations. Postoperatively, plasma cortisol and urinary 17-OHCS were below normal. Histologic examination of the tumor indicated the presence of two types of adenoma cells; one was a large watery clear cell with rich lipid and possibly with aldosterone secretion and the other was an acidophilic cell with poor lipid and possibly with cortisol secretion. It is suggested that, in addition to oversecretion of aldosterone, the tumor autonomously secreted cortisol, although the amount of cortisol secreted was not large enough to produce typical Cushing's syndrome.

Adenoma↗
PubMed1979

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↗
PubMed1977

Pharmacokinetics of dibekacin after intramuscular administration in man.

Pharmacokinetic behavior of dibekacin after intramuscular administration was studied in nine healthy volunteers by cross over administrations of three dosage levels (1 mg(pot.)/kg, 1.5 mg(pot.)/kg and 2 mg(pot.)/kg). Drug concentrations in serum and urinary recoveries were measured and those data were analysed pharmacokinetically. The serum levels of this drug were in proportion to dosage, and the pharmacokinetic parameters were almost the same through the three dosage levels. Then it was considered that the pharmacokinetic behaviors of dibekacin were almost the same within the range of these dosage levels. No significant difference was found between the body clearances calculated from the data of serum levels, and the renal clearances calculated from the data of urinary recovery and serum levels. Therefore it is considered that the elimination of the drug from blood is almost due to renal excretion.

Adult↗