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Biomedical subjects

M Inada

Publications and source records attributed to M Inada.

At least 397 records · Page 22Linked to original sources
PubMed1981

Modulation of T4 5'-monodeiodination in rat anterior pituitary and liver homogenates by thyroid states and fasting.

In order to clarify the role of the pituitary conversion of L-thyroxine (T4) to 3, 5, 3'-L-triiodothyronine (T3) in regulating thyrotropin (TSH) secretion, the effect of altered thyroid states and fasting on intrapituitary T3 generation was investigated by a paperchromatographic procedure using the anterior pituitary homogenates. Hepatic T3 generation was also studied for comparison. The rate of pituitary and hepatic T3 generation in normal rats averaged 25.2 +/- 12.4 (mean +/- SE) fmoles T3/mg protein/min and 33.8 +/- 12.7 fmoles T3/mg protein/min, respectively. T4 treatment raised the hepatic T3 generation from T4 (46.7 +/- 3.1 fmoles T3/mg protein/min) and lowered the intrapituitary T3 generation (4.5 +/- 0.2 fmoles T3/mg protein/min). On the contrary, thyroidectomy slowed the hepatic T4 5'-deiodination (11.0 +/- 2.8 fmoles T3/mg protein/min), and accelerated the pituitary T4 5'-deiodination (64.3 +/- 1.4 fmoles T3/mg protein/min). In 48 h fasted rats, serum T4, T3 and TSH concentrations were all lower than those in fed rats, and both pituitary and hepatic T3 generations were also suppressed. Thus, altered thyroid states cause an opposite effect on pituitary and liver 5'-monodeiodination, whereas fasting causes similar changes. The findings suggest the existence of an autoregulatory mechanism for thyroid hormone activation within the target tissues.

Animals↗
PubMed1980

An improved preparation of antibody-coated polystyrene beads for sandwich enzyme immunoassay.

An improved preparation of antibody-coated polystyrene beads for sandwich enzyme immunoassay of human thyroid-stimulating hormone (TSH) was described. Rabbit anti-TSH IgG was purified by eluting at pH 2.5 from a TSH-Sepharose column, diluted 3 or 9 fold with normal rabbit IgG and used for coating polystyrene beads by physical adsorption. In a sandwich enzyme immunoassay of TSH using rabbit (anti-TSH) Fab'-beta-D-galactosidase conjugate, beta-D-galactosidase activities specifically bound to thus prepared polystyrene beads in the presence of TSH was 2.8-6.3 fold higher than those bound to polystyrene beads coated with anti-TSH IgG before purification. A similar effect was observed when guinea pig anti-pork insulin IgG, rabbit (anti-human IgE) IgG and goat (anti-human IgE) IgG were treated at pH 2.5. This improvement may be based on a conformational change of Fc in IgG molecule which was caused by the treatment at pH 2.5. Other sandwich immunoassays such as fluoro- and radio-immunoassays may also be improved in the same way.

Animals↗
PubMed1980

Effect of 3,5,3'L-triiodothyronine administration on serum thyroid hormone levels in hypothyroid patients maintained on constant doses of thyroxine.

In order to investigate the effect of 3,5,3'L-triiodothyronine (T3) administration on thyroid hormone concentrations in serum, thyroxine (T4), T3, 3,3',5'L-triiodothyronine (reverse T3, rT3) and thyroid stimulating hormone (TSH) concentrations in serum were determined before and after T3 administration in 10 hypothyroid patients maintained on constant doses of T4. Ten hypothyroid patients given 100 micrograms of T4 for approximately 3 months had almost normal T4 and T3 concentrations in serum. Seven patients showed almost normal rT3 concentrations in serum and they were slightly diminished in the remaining 3 patients. TSH levels in serum were almost within the normal limit in 7 out of 10 patients. However, despite the elevation of T4 and T3 levels, 3 patients had markedly elevated TSH levels. Values for serum T4 concentrations were decreased 4 weeks after the administration of 50 micrograms T3 in all patients maintained on constant doses of T4, although they were almost within the normal range. T3 concentrations in serum, which was obtained just before the administration of the next daily doses of T3, were markedly elevated in 6 of 10 patients after T3 administration and the remaining 4 patients had also slightly higher T3 concentrations than those before T3 administration. On the other hand, serum rT3 concentrations were diminished in 5 patients during T3 ingestion. They were somewhat diminished or almost unchanged before and after T3 administration in the remai T3 administration and the remaining 4 patients had also slightly higher T3 concentrations than those before T3 administration. On the other hand, serum rT3 concentrations were diminished in 5 patients during T3 ingestion. They were somewhat diminished or almost unchanged before and after T3 administration in the remaining 5 patients. Moreover, 3 patients with elevated TSH levels during T4 administration showed almost normal TSH levels after T4 and T3 ingestion. The results showed the reciprocal relationship between T3 and rT3 levels in serum after T3 administration in hypothyroid patients maintained on constant doses of T4. Furthermore, the present findings suggest that the administration of both T4 and T3 might be a more suitable replacement therapy in the patients with hypothyroidism than T4 alone.

Drug Therapy, Combination↗
PubMed1980

Clinical evaluation of measuring glycosylated hemoglobin levels for assessing the long-term blood glucose control in diabetics.

The glycosylated hemoglobin levels were determined in the hemolysates obtained from 14 normal subjects and 67 patients with adult-onset diabetes mellitus, using the column chromatographic procedure of Trivelli et al. The levels of hemoglobin A1a+b (HbA1a+b) and HbA1c and the sum of HbA1a+b and HbA1c (HbA1a+b+HbA1c) in normal subjects averaged 2.3 +/- 0.4 (SD)%, 5.3 +/- 0.8% and 7.6 +/- 1.0%, respectively. Although a slight increase in HbA1a+b was found in patients with diabetes mellitus (mean +/- SD=2.8 +/- 0.7%), it was not significantly different from that in normal subjects. Despite the wide range, HbA1c and HbA1a+b+HbA1c were significantly increased in patients with diabetes mellitus (6.9 +/- 1.8% for HbA1c, p < 0.01 and 9.7 +/- 2.2% for HbA1a+b+HbA1c, p < 0.01). A significant correlation existed between the glycosylated hemoglobins and plasma glucose levels determined in the same blood (r = +0.57, p < 0.001). Moreover, the glycosylated hemoglobin levels correlated significantly with the average glucose levels for several months preceding the hemoglobin measurements. In particular, a striking correlation was evident in the plots of HbA1a+b+HbA1c against the mean plasma glucose for 3 months prior to the hemoglobin measurements, which had a correlation coefficient of 0.79 (p < 0.001). The present findings revealed that the glycosylated hemoglobins reflect the time-averaged blood glucose levels in diabetics for during approximately the proceeding 3 months, indicating the usefulness of measuring the glycosylated hemoglobins in assessing the long-term blood glucose control in diabetics.

Adult↗
PubMed1979

Post-partum transient thyrotoxicosis: report of two cases.

Two patients with post-partum transient thyrotoxicosis associated with painless thyroiditis and low radioactive iodine uptake were described. The surreptitious use of thyroid hormones or iodine was excluded. Although the clinical course was compatible with that of subacute thyroiditis, passing through the hyperthyroid, euthyroid, hypothyroid and recovery phase, the patients showed a sustained elevation of serum anti-thyroglobulin antibody titer during the entire phase of the disease. Moreover, the histological findings obtained by the thyroid biopsy performed in a case were characteristic of chronic lymphocytic thyroiditis. Furthermore, it was of interest that the disease recurred following every delivery in 2 cases, suggesting the possible role of immunological changes induced by pregnancy and delivery in the etiology of this disease.

Adult↗
PubMed1979

Transient thyrotoxicosis associated with painless thyroiditis and low radioactive iodine uptake.

We describe a patient with transient thyrotoxicosis and low radioactive iodine uptake by the thyroid. Although the clinical course in this patient was compatible with subacute thyroiditis, she did not experience pain or tenderness in the neck. The use of thyroid hormones or iodine was excluded. The substantial level of thyroid antibody in serum was present during the entire phase of the disease. Histological findings on thyroid biopsy were characteristic of chronic lymphocytic thyroiditis. Furthermore, it was remarkable that the histological abnormalities improved spontaneously during the course of several months, with the spontaneous recovery of clinical signs and biochemical abnormalities.

Adult↗