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Biomedical subjects

T Friis

Publications and source records attributed to T Friis.

At least 19 recordsLinked to original sources
PubMed1992

Hypocalcemia and parathyroid hormone responsiveness in diabetes mellitus: a tri-sodium-citrate clamp study.

The aim of this study was to elucidate the diabetic hypocalcemia and PTH responsiveness, investigated by measuring blood ionized calcium and serum intact parathyroid hormone (S-PTH(1-84)) concentrations, before and during an induced and maintained controlled hypocalcemia. In 15 patients with insulin-dependent diabetes mellitus and 19 healthy volunteers the blood ionized calcium concentration was lowered by about 0.20 mmol/l and maintained at this level by blood ionized calcium controlled tri-sodium-citrate infusion. In patients vs controls, baseline measurements averaged for blood ionized calcium (mmol/l) 1.18 +/- 0.08 vs 1.24 +/- 0.03 (p less than 0.01), for S-magnesium (mmol/l) 0.73 +/- 0.07 vs 0.81 +/- 0.07 (p less than 0.01) and for S-PTH (1-84) (pmol/l) 3.0 +/- 1.0 vs 3.1 +/- 1.0 (p greater than 0.75). During the clamp, S-PTH (1-84) peaked to comparable maximums after 5-10 min in both groups and then declined to constant concentrations two to three times above their control levels. In conclusion, we found a diabetic hypocalcemia and hypomagnesemia, though baseline levels of PTH and PTH responsiveness were normal. This may be taken to indicate a mild shift downwards in the set-point for PTH secretion in patients with insulin-dependent diabetes mellitus.

Adult↗
PubMed1979

Serum T4, T3 and reverse T3 during treatment with propranolol in hyperthyroidism, L-T4 treated myxedema and in normal man.

Serum concentrations of T4, T3 and reverse T3 were studied in two hyperthyroid groups (n = 13 and 11), in a group of normals (n = 9) and in a group of L-T4 substituted patients (n = 7) with severe pretreatment hypothyroidism. Serum T4 did not change except in one of the hyperthyroid groups change to in which a slight decrease was found. In all groups a significant fall in serum T3 and a significant rise in serum reverse T3 were found. An expected increase in serum TSH in the normal and in the L-T4 substituted groups could not be demonstrated.

Adult↗
PubMed1979

The influence of propranolol on the extrathyroidal metabolism of 3,3',5'-triiodothyronine (reverse T3).

The effect of propranolol 80 mg daily on the metabolism of 3,3',5'-triiodothyronine (reverse T3, rT3), 3,3',5'-triiodothyronine (T3) and thyroxine (T4) was studied by means of a non compartmental kinetic method in seven females with severe pretreatment hypothyroidism. The patients were maintained euthyroid on a constant L-T4 replacement therapy. Serum rT3 levels increased significantly during propranolol (p less than 0.02). This increase was explained by a decrease in metabolic clearance rate (MCR) (p less than 0.02), since the conversion rate from T4 and the distribution volume of rT3 were unchanged. By contrast the decreased serum levels of T3 were due to a significant decreased conversion from T4 (p less than 0.02) in spite of a decreased MCR. The results are compatible with the assumption of two different monodeiodinating enzymes, a 5-deiodinase responsible for the diodination of T4 to rT3 and a 5'-deiodinase responsible for the deiodination of T4 to T3.

Female↗
PubMed1979

Osteoporosis in hyperthyroidism estimated by photon absorptiometry.

The degree of osteoporosis in hyperthyroidism before and during treatment with carbimazole was studied by photon absorption technique of the right forearm and calcaneus. In addition serum total calcium, serum ionized calcium, serum phosphorus and serum alkaline phosphatase were determined. A group of 96 patients suffering from untreated hyperthyroidism (85 women and 11 men) was studied (79 of these patients were also followed during treatment) and compared to a control group of 157 persons (107 women and 50 men). The women were divided into two groups: less than or equal to 45 years old and more than 45 years old. In all groups untreated hyperthyroid patients showed lower bone densities compared to the control group, but this was only significant in women. During treatment all groups showed a significant increase in density. After 3-6 months of treatment bone density in the calcaneus increased 12% and in the forearm 1.5%; after 6 months - 3 years 33% and 31%, respectively. At that time bone density was normalized. There was no correlation between bone density in hyperthyroid patients and duration and severity of the disease. The biochemical changes were characterised by increases in serum alkaline phosphatase (26%), serum total calcium (16%) and serum ionized calcium concentration (17%) in cases of untreated hyperthyroidism. Serum phosphorus concentration did not change. A correlation was found between elevation of the alkaline phosphatase and decreased bone density.

Adult↗
PubMed1979

Subclinical hypothyroidism in Addison's disease.

Fourteen patients with Idiopathic Addison's disease (IAD) were studied in order to detect a possible subclinical hypothyroid state. All were clinically euthyroid with normal serum thyroxine (T4) and serum 3,5',5'-triiodothyronine (T3). Eleven had circulating thyroid microsomal antibodies in blood. The mean basal serum TSH was significantly higher than that of the control group but only three patients had values above the upper normal range. The mean value of serum T4 was decreased as compared to that of the normal persons, while serum 3,3',5'-triiodothyronine was elevated. 7.5 mU bovine thyrotrophin per kilogram body weight injected intravenously caused a rise in serum T3 not different from the response in normals. However, as well increasing serum TSH as increasing microsomal antibody titer correlated significantly to decreasing thyroidal release of T3. Our results suggest that clinically euthyroid patients suffering from IAD might have a beginning thyroidal insufficiency because of a progressive immunological damage of the thyroid.

Addison Disease↗
PubMed1978

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↗
PubMed1978

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↗
PubMed1978

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↗
PubMed1978

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↗
PubMed1977

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↗