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Biomedical subjects

N Hamada

Publications and source records attributed to N Hamada.

At least 235 records · Page 13Linked to original sources
PubMed1983

Chronic effect of TSH on human thyroid tissue in organ culture.

The chronic effect of TSH on thyroidal cAMP concentrations and release of thyroid hormones was investigated using human thyroid tissue in organ culture. Normal human thyroid slices were placed in HAM's F-10 synthetic culture medium in Falcon organ tissue culture dishes, and incubated at 37 degrees in a humidified atmosphere of 5% CO2 in air. Medium was changed everyday and daily T3 or T4 release was determined using concentration of T3 or T4 in the medium. After incubation, slices were transferred to the medium containing 10 mM theophylline and incubated without TSH for an additional 30 min to determine thyroidal cAMP concentrations. Thyroidal cAMP concentrations in slices incubated with 10 mU/ml of TSH increased significantly at 2, 6, and 24 hr and even on the 6th day of incubation. Daily T3 release was significantly increased above control from the 3rd day and daily T4 release from the 4th day to the 11th day of incubation with 10 mU/ml of TSH. Histologically, almost all follicles were structurally maintained even on the 11th day of incubation. These results suggest that both thyroidal cAMP concentrations and release of thyroid hormones are stimulated chronically by TSH. This organ culture system is useful for investigating chronic effects of various materials on human thyroid tissue.

Cyclic AMP↗
PubMed1983

[Monitoring of I-125 contamination in vivo by analysis of the saliva].

Monitoring of workers who did iodination of protein was performed for 5 months on 10 persons. The activity in saliva was evaluated following the sun peak method by using a NaI(Tl) detector and a 400-channel analyzer. The concentration of 125I in saliva ranged 4.65 +/- 2.1 cBq (1.26 +/- 0.57 pCi)/ml to 135 +/- 2.7 cBq (36.45 +/- 0.73 pCi)/ml and the average was 20.8 +/- 1.9 cBq (5.62 +/- 0.51 pCi)/ml. The ratio of concentration in saliva to used activity ranged (2.2 +/- 0.64) X 10(-9) to (3.6 +/- 0.073) X 10(-8) and the average was (8.1 +/- 1.1) X 10(-9). The thyroidal uptake per iodination ranged 146 Bq (3.94 nCi) to 2700 Bq (72.9 nCi). The ratio of the uptake to the used activity ranged from 7.3 X 10(-5) to 5.4 X 10(-6). The thyroidal absorbed dose ranged from 378 microGy (37.8 mrad) to 4740 microGy (474 mrad). Monitoring of 125I-in saliva was proved to be a useful method to investigate the internal contamination of workers doing iodination.

Environmental Exposure↗
PubMed1982

Anterior pituitary, thyroid, parathyroid and adrenal responses to subtotal thyroidectomy in patients with Graves' disease.

Changes in the serum levels of anterior pituitary, thyroid, parathyroid, and adrenal hormones following subtotal thyroidectomy in 31 patients with Graves' disease were investigated. In 14 patients, rapid ACTH tests were performed on the preoperative and the first, third, and seventh post-operative days. Remarkable differences were not seen with regard to the changes in anterior pituitary hormones or cortisol, compared to those seen during general surgery. As to the thyroid hormones, the serum level of triiodothyronine (T3) decreased markedly after surgery and fell to half that of the preoperative value on the first postoperative day. Thereafter, a low value of T3 was maintained during the early postoperative period. Unlike T3, the serum level of thyroxine (T4) decreased gradually until the 7th post-operative day. The levels of both epinephrine and norepinephrine increased transiently during surgery, but the serum level of norepinephrine increased again on the third postoperative day. In the postoperative period, almost half the number of patients showed an inadequate cortisol response to rapid ACTH tests. It is suggested that the unique responses, such as the rise in serum norepinephrine or an inadequate response of cortisol to ACTH, or hypocalcemia, after subtotal thyroidectomy in patients with Graves' disease is largely due to the rapid decrease of T3 in the hypothyroid state, as was noted during the postoperative period.

Adult↗
PubMed1982

Management of atrial fibrillation in the post-thyrotoxic state.

This study was designed to investigate the appropriate timing for cardioversion in patients with chronic atrial fibrillation who had been rendered euthyroid from a thyrotoxic state. We carried out a retrospective study of 163 patients with thyrotoxic atrial fibrillation, with a mean follow-up of 34 months. With control of thyroid function alone, 101 patients had spontaneous reversion of atrial fibrillation to sinus rhythm and 62 patients had persistent atrial fibrillation. In those with spontaneous reversion, the longest duration of atrial fibrillation prior to the euthyroid state was 13 months. In those with persistent fibrillation, the shortest duration of atrial fibrillation prior to the euthyroid state was eight months. Almost three-quarters of those with spontaneous reversion had conversion to sinus rhythm within three weeks of becoming euthyroid. No spontaneous reversion occurred if atrial fibrillation was still present after the patients had been in a euthyroid state for four months. This study suggests that spontaneous reversion of atrial fibrillation to sinus rhythm is highly unlikely if the duration of atrial fibrillation before the euthyroid state is achieved exceeds 13 months, or if it is still present after the patient has been in a euthyroid state for four months, Cardioversion should be performed at about the 16th week after the euthyroid state is achieved.

Adult↗
PubMed1982

A case report on disequilibrium hypercalcemia in hyperthyroidism. Comparison of calcium metabolism with other patients with hyperthyroidism.

The patient, a 30-year-old woman, was admitted to Itoh Hospital in February, 1979 for hyperthyroidism. She had a history of pyelonephritis and recurrent urinary tract infection. Laboratory data on admission revealed overt hyperthyroidism (T3: 405 ng/dl, T4: 22.5 micrograms/dl and T3U: 57.--%), severe hypercalcemia of 12.6 mg/dl and hypercalciuria. The PSP excretion and GFR were both decreased. Serum c-PTH was nondetectable. As the thyroid function improved, there was a gradual decrease and later normalization of plasma calcium, phosphate and urinary calcium excretion. When subtotal thyroidectomy was performed on October 19, 1979, hypertrophy of the parathyroid gland was not demonstrated. In comparison with 98 other hyperthyroid patients, the pathogenesis of hypercalcemia was discussed. In conclusion, hypercalcemia in the patient, T. Y., was regarded as a kind of disequilibrium hypercalcemia which resulted from a combination of increased bone turnover and decreased calcium excretion by the kidney.

Adult↗
PubMed1982

[Change of pattern of gastric emptying after selective proximal vagotomy].

The patterns of gastric emptying after selective proximal vagotomy (SPV) and SPV with pyloroplasty (SPV + D) were studed using a liquid labelled with 99mTc-DTPA. By means of on-line computer facility, it was possible to analyse the relative role of the Whole stomach and the antrum within the overall frame work of gastric emptying. In the time/activity curve of the whole stomach, all of 3 groups emptied in exponential curve. Comparing with normal subjects, SPV subjects were tending to empty slowly, while SPV + D subjects were tending to empty rapidly. In the time/activity curve of the antrum, normal and SPV + D subjects had two types of emptying--one was represented in the decreasing curve and another was represented in the increasing-decreasing curve. While SPV subjects had only one type of emptying which was represented in the increasing-decreasing curve. From a consideration of the pattern of gastric emptying curve, SPV subjects had two different emptying states compared with normal subjects--one was the delay of entering the antrum from the fundic side of stomach, and the other was that effective antral emptying did not readily start. While SPV + D kept more neally normal gastric emptying that it of SPV.

Adult↗
PubMed1980

Serum coenzyme Q10 levels in thyroid disorders.

The correlation between serum CoQ10 levels and serum thyroid hormones in thyroid disorders was investigated in the present studies. Serum CoQ10 was measured by high speed liquid chromatography utilizing ultraviolet detector. In normal controls, serum CoQ10 level of the male was higher than that of the female. Serum CoQ10 level in hyperthyroidism was significantly lower than that of euthyroid subjects. But in hypothyroidism, serum CoQ10 level did not show any significant difference from that of euthyroid subjects. Significant inverse correlations were demonstrated between log CoQ10 and log T3, log T4, log free T4, or log rT3. These data suggested abnormalities in the mitochondrial electron transport system in thyroid disorders.

Adolescent↗
PubMed1980

Malignant fibrous histiocytoma of the heart.

A 33-year-old woman presented signs and symptoms which suggested mitral stenosis and insufficiency. Subsequent echocardiographic and angiographic testing demonstrated a left atrial tumor which was suspected clinically to be a left atrial myxoma. At surgery, the tumor was partially resected and histological examination revealed that the mass to be a malignant fibrous histiocytoma. At autopsy, the tumor was found to be localized in the heart, and there was no metastasis.

Adult↗