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Biomedical subjects

T Friis

Publications and source records attributed to T Friis.

At least 73 records · Page 4Linked to original sources

Urinary excretion of 3,3',5'-triiodothyronine (reverse T3).

A simple and sensitive radioimmunoassay for reverse T3 in urine using small Sephadex G25 fine columns is described. The recovery of rT3 added to urine was on average 101.0 +/- 4.2% (mean +/- SEM). Detection limit was 4 pg/column. Urine excretion of rT3 (mean +/- SD) was 72.0 +/- 32.1 ng/24 h in 61 healthy euthyroid subjects with a slight increase with age (P less than 0.05), 28.8 +/- 18.2 ng/24 h in 12 hypothyroid patients and 183.6 +/- 79.7 ng/24 in 25 hyperthyroid patients.

Adolescent↗

Effect of propranolol on extrathyroidal metabolism of thyroxine and 3,3',5-triiodothyronine evaluated by noncompartmental kinetics.

Kinetic studies of T4 and T3 using a noncompartmental approach were performed in seven patients with pretreatment severe hypothyroidism maintained on L-T4 replacement. Each subject received a combined tracer dose of labeled T4 and T3 as an iv bolus before and during peroral treatment with propranolol. Serum T4 was unchanged, while a significant decrease of 13% was found in serum T3. The disposal rates (DR) of T4 and T3 decreased significantly, and the ratio between the DR off T3 and the DR of T4, the conversion rate, was significantly reduced during propranolol treatment. The decrease in the DR of T4 suggests a reduction in the bioavailability of L-T4 during propranolol, possibly due to a decrease in intestinal absorption. The decrease in the conversion rate indicates a reduced extrathyroidal conversion of T4 to T3 during propranolol treatment.

Adult↗

Extrathyroidal effects of propylthiouracil and carbimazole on serum T4, T3, reverse T3 and TRH-induced TSH-release in man.

A possible extrathyroidal effect of propylthiouracil (PTU) and carbimazole on serum levels of thyroxine (T4), triiodothyronine (T3), 3,3',5'-triiodothyronine (reverse T3) and on thyrotrophin-releasing hormone (TRH) induced thyrotrophin (TSH) release was estimated in 19 patients with severe hypothyroidism treated with T4. During PTU medication a significant decrease in serum T3 from 90 +/- 16 (SD) to 79 +/- 23 ng/100 ml (P less than 0.01) and a reciprocal increase in serum reverse T3 from 51 +/- 14 (SD) to 58 +/- 20 ng/100 ml (P less than 0.025) were found. No significant changes in serum T4, basal serum TSH or response to TRH could be demonstrated. Carbimazole did not change any of the parameters studied.

Adult↗

Radioimmunoassay of 3,3',5'-triiodothyronine (reverse T3) on small reusable sephadex columns.

A simple radioimmunoassay for serum reverse triiodothyronine on small reusable Sephadex G 25 fine columns has been developed. The assay was unaffected by serum volumes of up to 100 microliter. The recovery of reverse T3 added to serum was in the mean 98.3 +/- SEM 3.2% and the coefficient of variation within and between assay determinations 5.4% and 7.5%, respectively. The detection limit was 2.2 pg reverse T3/column. Serum reverse T3 in 58 euthyroid controls was in mean 48 +/- SD 9 ng/100 ml, and was positively correlated to age (P less than 0.001). No overlap was found between the control group, and the hypo- and hyperthyroid group respectively. Three patients with T3-toxicosis had a normal serum rT3.

Adsorption↗

The clinical value of serum triiodothyronine, thyroxine and thyrotropin estimations during medical antithyroid treatment.

The relation between clinical status and serial determinations of serum T3, serum T4 and serum TSH has been evaluated in the early phase of medical antithyroid treatment in 12 unselected hyperthyroid patients, and in 19 patients who later during treatment accidentally developed low serum T4 values. Determination of both serum T3 and serum T4 was found necessary to avoid undertreatment. Two patients with signs of hypothyroidism in the early phase developed low serum T4, while serum T3 and serum TSH remained normal. In all of the 19 patients selected with low serum T4, serum T3 was normal. Serum TSH was elevated in 5 patients without hypothroid symptoms, while 2 developed hypothyroid symptoms in spite of normal serum TSH values. Our results suggest that serum T4 is a more sensitive parameter than both serum TSH and serum T3 in avoiding overtreatment during medical antithyroid treatment.

Adult↗

Treatment of senile osteoporosis with 1alpha-hydroxyvitamin D3.

About 30% of patients with clinical osteoporosis had histological signs of osteomalacia, in spite of normal serum 25-hydroxyvitamin D3 (25-OHD3). The excess osteoid disappeared during treatment with 1alpha-hydroxyvitamin D3 (1alpha-OHD3). These patients might have reduced ability to convert 25-OHD3 to 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3). The intestinal calcium absorption increased during treatment with 1alpha-OHD3, but this was accompanied by a rise in urinary calcium excretion. Photon absorptiometry of the forearm indicated increased bone mineral content during treatment with a daily dose of 2 microgram 1alpha-OHD3 and a supplement of 1 g of calcium. This therapeutic combination, however, caused frequent episodes of hypercalcaemia, so further studies are necessary to evaluate an appropriate dose of 1alpha-OHD3 with or without a calcium supplement.

Aged↗

Effect of 1alpha-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 on intestine and bone in glucocorticoid-treated patients.

The effect of 1alpha-hydroxyvitamin D3 (1alpha-OHD3) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on the intestinal calcium absorption was studied in twenty patients with rheumatoid arthritis treated with prednisone at daily doses of 5--15 mg for 1/2--20 years. The fractional calcium absorption, measured before and after the treatment with the vitamin D compounds, increased in nineteen of the twenty patients. This was, however, accompanied by marked rises in the urinary calcium excretion. There was no correlation between the fractional calcium absorption and the duration of the prednisone treatment or the doses given.

Arthritis, Rheumatoid↗

Outcome of long-term antithyroid treatment of graves' disease in relation to iodine intake.

Seventy-seven patients with Graves' disease, with an average of 56 years of age were treated with carbimazole in the period 1968-1975. The duration of therapy was on an average, 17.9 months and the follow-up on an average, 28.5 months. Remission was found only in 32% of the patients. Data on the urinary iodine excretion from a total of 127 euthyroid controls and 15 patients with Graves' disease living in the same area were collected during the periods: 1962-1964, 1965-1968, 1971-1973 and 1972-1974. No significant difference was found in the urinary iodine excretion in the period 1962-1973 and no significant difference was found in the urinary iodine excretion between the patients with Graves' disease and the euthyroid controls. Our data demonstrate a high relapse rate following long-term treatment with anti-thyroid drugs in an area with relative low iodine intake.

Adult↗

Glucose tolerance and insulin secretion in hyperthyroidism.

To evaluate the glucose tolerance and insulin secretion in hyperthyroidism patients were examined in the toxic state and after they had been made euthyroid. Fasting values: In 42 untreated patients the glucose- and insulin concentrations in serum were significantly elevated. In 24 treated patients the glucose concentrations became normal, while the insulin concentrations remained elevated. Oral-glucose-tolerance test: In 20 untreated patients the glucose- and insulin responses were significantly increased. In 8 treated patients the glucose response became normal, while the insulin response remained unchanged. Intravenous-glucose-tolerance test: In 28 untreated patients the K-values were significantly decreased and the insulin response increased. In 23 treated patients the K-values rose significantly, but the insulin response remained unchanged. Intravenous-tolbutamide test: In 41 untreated patients the glucose concentration decreased significantly compared with the controls, and the insulin responses were significantly increased. In 23 treated patients the glucose concentrations decreased even more, while the insulin response remained unchanged. The results indicate enhanced sensitivity or an increase in the mass of beta-cells in hyperthyroidism. The glucose tolerance tests point to an increased peripheral insulin resistance. The normalized glucose tolerance and still enhanced insulin secretion during treatment support the assumption, that hyperthyroidism causes an increase in the beta-cell mass.

Administration, Oral↗

Intravenous and peroral TRH stimulation in sporadic atoxic goitre.

Thyrotrophin releasing hormone (TRH) stimulation test with 200 microng iv was performed in 35 patients with atoxic sporadic goitre. In 23 patients with diffuse goitre 7 showed a lack of increase in serum thyrotrophin (TSH) at a significantly increased frequency compared to controls (P = 0.0028). In 4 patients with solitary nodules 2 showed no significant response to TRH (negative), while 3 of the 8 patients with multinodular goitres had negative TRH test. Only 6 of the 12 TRH negative patients also had non-suppressible 131I uptake following T3. No significant difference in age and thyroid parameters was found between the TRH negative and TRH positive patients. In 7 TRH negative patients the test was repeated with 400 microng TRH but all remained negative. Five of these patients were given TRH perorally 80 mg daily for 2 weeks resulting in a significant increase in serum T4 and T3. No detectable increase in TSH was found. The response to iv bovine TSH in 4 TRH negative patients was found to be normal, suggesting that there was normal thyroid sensitivity to TSH. Our findings suggest that patients with TRH negative atoxic goitre can release biological active TSH following prolonged TRH stimulation. The high frequency of a negative standard TRH test in atoxic goitre seems to diminish the diagnostic value of the standard TRH test.

Administration, Oral↗

Thyroid hormone response to varying doses of TSH.

Fifty-five normal subjects were studied following intravenous injection of increasing doses of bovine thyrotropin (b-TSH) from 0.5 to 250 mU/kg. Serum triiodothyronine (T3) and thyroxine (T4) were measured 1, 2, 3 and 4 h after the TSH injection. Dose-related increments in serum T3 and T4 were demonstrated with doses of b-TSH = 2.5 mU/kg and a maximum response was obtained after approximately 100 mU/kg. The fractional increase in serum T3 was greater than in serum T4, but the ratio between the increase in serum T4 and serum T4 and serum T3 (21.3/l ng/ng) was independent of the dose of b-TSH and time after TSH stimulation. The T3 response was reproducible and unaffected by sex and age.

Adolescent↗