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Biomedical subjects

L Tegler

Publications and source records attributed to L Tegler.

36 records · Page 2Linked to original sources
PubMed1982

Preferential secretion of triiodothyronine in man.

The directly measured secretion rates of thyroxine (T4), 3,5,3'-triiodothyronine (T3), and 3,3',5'-triiodothyronine (rT3) were compared to the tissue concentrations of these hormones and to the distribution of follicular iodoproteins in 15 patients submitted to thyroid or parathyroid surgery. The T4/T3 and rT3/T3 ratios were higher for thyroid tissue than for the secretion rates, indicating a preferential secretion of T3. The concentrations of T4 and T3 were higher in the 27S iodoprotein fraction than in the 19S thyroglobulin fraction.

Adult↗
PubMed1982

Secretion rates of thyroxine, triiodothyronine, and reverse triiodothyronine in man during surgery.

The secretion rates of T4, T3, and rT3 were studied in experiments of short duration by a new method based on determinations of the hormone difference across the thyroid combined with simultaneous electromagnetic thyroid blood flowmetry during surgery in 70 euthyroid patients. The secretion rate of T3 was similar in normal thyroid tissue and nodular goitre, but those of T4 and rT3 were lower in nodular goitre and solitary adenoma (P less than 0.05). In 61 patients with normal thyroid tissue or nodular goitre the secretion rates during surgery (mean +/- SEM) were for T4 222 +/- 28 nmol/day, for T3 27.4 +/- 3.1 nmol/day, and for rT3 3.5 +/- 0.5 nmol/day. In relation to the individual T4 secretion rate, the secretion rate of T3 was 12.5 +/- 3.0% and that of rT3 1.2 +/- 0.9%. In these short-term experiments we found a secretion rate for T4 during operation about 50% greater than in earlier long-term kinetic studies, but which tallied with a recent report using a 4-compartment model. For T3 and rT3 it was 2-3 times greater than earlier estimates. The secretion was estimated to be 50% of the total production rate for T3 and 6% for rT3. If proportional adjustment were performed to yield a T4 secretion of about 130 nmol/day. T3 and rT3 secretion rates would still be greater than earlier reported.

Adenoma↗
PubMed1981

Human thyroid blood flow response to endogenous, exogenous human, and bovine thyrotrophin measured by electromagnetic flowmetry.

Human thyroid blood flow (TBF) was studied with electromagnetic flowmetry during operation. Measurements were made of the effect on TBF of injections of bovine TSH into one inferior thyroid artery in 6 patients; 6 other patients were given human TSH, and in 10 patients measurements were made both of TBF and endogenous TSH released after administration of TRH in a peripheral vein. The TBF increased after all three types of injection. The mean of the TBF maxima after bovine TSH was 2.26 +/- 0.35 (mean +/- SEM) relative to basal TBF, after human TSH 1.97 +/- 0.28, and after TRH 1.64 +/- 0.20. In the three groups combined it was 1.92 +/- 0.16. The TBF was often increased already during the first recording period 1-10 min after TSH or TRH administration. The mean TBF was approximately doubled at 30-50 min. There were considerable inter-individual variations in the latent time and maximum response of TBF, especially after human TSH, but we found no correlation between the response and the TSH serum concentration in any group. A prompt, but inter-individually varying, increase in TBF was confirmed. This increase is suggested to be secondary to an increased intrafollicular metabolic activity and not primarily regulating thyroid function.

Adult↗
PubMed1981

Calcium treatment of leg cramps in pregnancy. Effect on clinical symptoms and total serum and ionized serum calcium concentrations.

Up to 30 per cent of pregnant women suffer from leg cramps. The cause of these cramps is not known, but changes in calcium concentration have been suggested. Therefore 42 pregnant women with leg cramps were studied. No differences in total serum or ionized serum calcium concentrations were found as compared with a control group of pregnant women without leg cramps. Twenty-one patients were treated with 1 g calcium orally twice daily for 2 weeks and in this group good clinical improvement was achieved (p less than 0.001). The treatment increased the total serum calcium concentration from 2.25 mmol/l to 2.30 mmol/l but did not alter the ionized serum calcium concentration. Twenty-one untreated patients had the same frequency of cramps and showed no change in serum calcium concentrations throughout the investigation.

Adult↗
PubMed1981

Screening for thyroid disorders in middle-aged women by computer-assisted evaluation of a thyroid hormone panel.

Free thyroxine index, free tri-iodothyronine index and thyrotropin were determined in connection with gynecological screening for cervical carcinoma on middle-age women. A total of 3885 women were investigated. Women with values outside a trivariate reference region were reinvestigated by renewed hormone determinations and those with hormone results still outside the reference region were subjected to clinical and further laboratory investigations. Thus 20 women (0.51% of the study population) with previously unknown hyperthyroidism and 25 women (0.64%) with previously unknown hypothyroidism were identified and successfully treated. Values outside the reference region were also studied by cluster analysis, which separated hyper- and hypo thyroid patients into different clusters. but allowed no further identification of different thyroid disorders. We conclude that laboratory screening for thyroid disorders may be justified in middle aged women if performed together with another screening program. Computer-assisted multivariate evaluation of the hormone results was of value of identification of subjects with thyroid disorders but their numerical classification by cluster analysis was of little practical value.

Adult↗
PubMed1980

Effects and plasma levels of propranolol and metoprolol in hyperthyroid patients.

The effects and plasma concentrations of different doses of propranolol and metoprolol were studied in 34 hyperthyroid patients. The initial daily doses were propranolol 160 mg or metoprolol 200 mg. If the resting heart rate remained above 75 beats per min after treatment for 4-7 days, the dose was increased and the patient re-examined after a further 4-7 days. Propranolol (n = 17) caused a reduced heart rate, a decrease in serum 3,3',5-triiodothyronine (T3) and an increase in serum 3,3',5'-triiodothyronine (reverse T3, rT3). In 10 patients, there was no change in T3 or rT3 until the daily dose of propranolol had been increased to 240 or 320 mg. The plasma level of propranolol was significantly correlated with the decrease in T3 and the increase in rT3. Metoprolol (n = 17) caused a reduction in heart rate similar to that following propranolol. However, serum T3 was only slightly reduced even after an increase in dose to 300 or 400 mg, and serum rT3 was not altered. Metoprolol concentrations were not significantly correlated with the fall in T3. It appears that the influence of beta-blockers on T4 conversion is of little importance for the clinical improvement in hyperthyroid patients, and rather it is a consequence of beta 1-adrenergic blockade interfering with the effect of T3. In addition, the findings support the assumption that therapeutic failure with beta-blockers in hyperthyroidism may be due to suboptimal treatment, and that individualized dosage is necessary.

Adult↗
PubMed1980

Insulin release and carbohydrate tolerance in hyperthyroid patients during non-selective or selective beta-1-adrenoceptor blockade.

The insulin release and the glucose disappearance rate (K-value) during an iv glucose tolerance test were evaluated in 20 hyperthyroid patients before and during treatment with either a non-selective (propranolol, n = 10) or a selective (metoprolol, n = 10) beta-1-adrenoceptor blocking agent. Mean daily doses were 240 mg of propranolol and 280 mg of metoprolol, administered four times daily for 10 to 14 days. The insulin increase after glucose injection remained unchanged during treatment with each drug. Fasting blood glucose concentrations and the K-values were not altered during treatment. Sixteen patients were re-investigated 10 to 36 weeks later when euthyroid due to treatment by surgery, thyrostatic drugs or radioiodine. In the euthyroid state mean serum insulin concentrations after the glucose load were not significantly different from the values found when the patients were hyperthyroid. However, mean fasting blood glucose concentrations decreased from 5.5 mmol/l to 5.0 (P less than 0.01) and the mean K-value increased from 1.5 to 2.0 (P less than 0.05) when the patients were euthyroid. It is concluded that short-term treatment of hyperthyroid patients with non-selective or selective beta-1-adrenoceptor blocking agents does not impair the glucose stimulated insulin secretion or the carbohydrate tolerance.

Adrenergic beta-Antagonists↗
PubMed1979

Non-selective and selective beta-1-adrenoceptor blocking agents in the treatment of hyperthyroidism.

Treatment for one month with propranolol or atenolol, a selective beta-1-adrenoceptor blocking agent, was evaluated in 20 hyperthyroid patients. The patients improved to the same extent on either drug, as shown by a clinical diagnostic index. Basal metabolic rate decreased by 11% during both treatments, while it was unchanged in seven untreated hyperthyroid controls. Thyroxine concentration did not change during any treatment. During propranolol treatment T3 decreased from 4.6 to 3.9 nmol/l, while no changes were observed during atenolol treatment or in the control group. No significant changes were seen in free T4, free T3 or rT3 concentrations on any treatment, although free T3 was observed to decrease slightly during propranolol treatment. Thus, the improvement of the clinical symptoms of hyperthyroidism cannot be explained by diminished thyroid hormone concentrations in serum, since the reduction was small during propranolol and absent during atenolol treatment.

Adolescent↗
PubMed1976

Controlled treatment of primary hypertension with propranolol and spironolactone. A crossover study with special reference to initial plasma renin activity.

Twenty-seven patients with hypertension were randomly allocated to a 10 month crossover study. Treatment consisted of spironolactone (200 mg/day for 2 months), propranolol (320 mg/day for 2 months) and combined administration of both drugs at half the dosage. Between treatment periods placebo was given for 2 months. Fourteen patients were previously untreated. The average pretreatment blood pressure for the entire group was 188/114 +/- 16/7(mean +/- standard deviation) mm Hg supine and 188/118 +/- 20/9 mm Hg standing. Both spironolactone and propranolol reduced blood pressure significantly in both the supine and standing positions. Upright plasma renin activity was determined by radioimmunoassay of angiotensin I. The average initial level was 1.9 +/- 1.2 (range 0.4 to 5.0) ng/ml/hr. There was a close correlation between plasma renin activity and the effects of the drugs: With increasing renin level the response to propranolol was better whereas the opposite was true for spironolactone. The combination of spironolactone and propranolol decreased the blood pressure still further in the supine and standing positions, irrespective of initial plasma renin activity. All patients achieved a normal supine pressure. Blood pressure and plasma renin activity returned toward pretreatment values during placebo administration. It is concluded that pretreatment levels of plasma renin activity can predict the antihypertensive response to propranolol and spironolactone. The combination of the two drugs, which have different modes of action, will effectively reduce blood pressure in hypertension. The results support the concept that the renin-angiotensin-aldo-sterone system may be involved in primary hypertension.

Adult↗
PubMed1976

Renin concentrations and effects of propranolol and spironolactone in patients with hypertension.

In a crossover study 32 patients with hypertension were randomly allocated to treatment with spironolactone 200 mg/day for two months, propranolol 320 mg/day for two months, and a combination of both drugs at half the dose. Between the treatments placebo was given for two months. Both spironolactone and propranolol lowered the blood pressure significantly in both positions. The initial plasma renin activity (PRA) levels ranged from 0-4 to 5-0 mug angiotensin I l-1 h-1, and there was a close correlation between these levels and the effects of the drugs: with increasing PRA the response to propranolol was better while the opposite was true for spironolactone. Spironolactone reduced the blood pressure more at eight than at four weeks, while no such difference could be shown for propranolol. Spironolactone and propranolol together decreased the blood pressure still further irrespective of the initial PRA. All patients achieved a normal supine blood pressure.

Administration, Oral↗
PubMed1976

Thyroid function after subtotal thyroidectomy for hyperthyroidism. A follow-up study with special reference to thyroid stimulating hormone (TSH) and the thyrotropin releasing hormone (TRH) stimulation test.

193 patients operated on for hyperthyroidism were examined at follow up a mean 4.5 years after operation (range 1-6 years). The patients were examined clinically and biochemically. It was found that 4.6% had a permanent paralysis of the recurrent nerve and 2.6% a permanent hypoparathyroidism. Recurrent hyperthyroidism was found in 2.6%. The patients were grouped according to the results of basal S-TSH and the TRH-stimulation test. Within the groups it was found that all patients with a normal basal TSH were clinically euthyroid. 35 patients had a raised basal TSH or a hypothyroid pattern in the TRH-test, or both. Among these, 14 clinically hypothyroid patients were found. The remaining 21 patients were euthyroid clinically and were classified as subclinically hypothyroid. The levels of basal TSH were significantly higher in subclinically hypothyroid patients than in euthyroid patients and still higher in clinically hypothyroid patients. The response to TRH stimulation was also higher in the hypothyroid patients than in the subclinically hypothyroid patients. It was also found that the proportion of clinically hypothyroid patients was significantly higher, after 5 years than after one year. Since it cannot be decided if the patients with a subclinical hypothyroidism are at risk for manifest disease a close follow up of these patients is recommended.

Adolescent↗
PubMedDate not supplied

Thyroid blood flow rate in man. Electromagnetic flowmetry during operation in euthyroid normal gland, nontoxic goiter, and hyperthyroidism.

Human thyroid blood flow rate (TBF) was measured during operations by electromagnetic flowmetry in 75 euthyroid patients with normal thyroid tissue, nodular goiter, or solitary adenoma, and in 22 hyperthyroid patients with diffuse or nodular goiter. Blood flow rate was measured in one to four of the thyroid arteries. No difference in blood flow rate was seen between the left and right lobes. The slight difference found between the inferior and superior arteries was not significant. In each subject, total TBF was calculated as 4 times the mean of the recorded blood flow in the single arteries. The total TBF was 31 (9-109) ml/min (inner 95 percentile range) in euthyroid patients, similar in all 3 groups. This is less than in most earlier reports. The relative TBF was 1.2 (0.4-3.8) ml/min/g thyroid tissue in normal thyroid tissue and 0.6 (0.1-3.7) ml/min/g in nontoxic nodular goiter (p less than 0.01). Patients with hyperthyroidism had a higher total TBF 54 (15-197) ml/Min (p less than 0.001), despite preoperative treatment giving euthyroidism, Similar TBF rates were found in 3 hyperthyroid patients given propranolol preoperatively. Electromagnetic flowmetry is applicable to study thyroid blood flow rate. Human TBF shows considerable interindividual variations, which must be kept in mind when studying directly the rate of thyroid hormone secretion from arteriovenous gradients.

Adult↗
PubMedDate not supplied

Effects of portal glucose infusion on thyroid hormone concentrations in serum after high energy trauma in pigs.

The effect of portal glucose infusion on serum thyroid hormone levels was studied in five anaesthetized pigs during 48 h observation in an intensive care unit following standardized high energy trauma. At 10-18 h post-trauma, and again at 28-36 h, 100 g glucose was infused into the portal circulation via a splenic vein. In six animals, otherwise treated in the same way, the glucose infusions were given via a peripheral venous catheter. During portal glucose infusion at 28-36 h post-trauma, serum T3 rose significantly above the level in the controls. After termination of the portal glucose infusion, the serum concentration again fell. At 48 h the rT3 concentration was significantly lower in the pigs given portal glucose than in the control pigs. It was concluded that portal, but not peripheral, glucose infusion can temporarily reverse the trauma-induced change in triiodothyronine metabolism. This indicates that increase of the splanchnic, and more specifically the hepatic, glucose concentration could be important for amelioration of the low T3 state.

Animals↗