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Biomedical subjects

J M Hansen

Publications and source records attributed to J M Hansen.

At least 127 records · Page 7Linked to original sources
PubMed1983

The determination of thyroid volume by ultrasound and its relationship to body weight, age, and sex in normal subjects.

Using a precise and accurate ultrasonic scanning technique we have measured the volume of the thyroid gland in vivo in 271 healthy subjects (13-91 yr old). In these subjects the mean (+/- SD) thyroid volume was 18.6 +/- 4.5 ml. A significant difference between males (19.6 +/- 4.7 ml; n = 139) and females (17.5 +/- 4.2 ml; n = 132) was found (P less than 0.001). The thyroid volume was significantly correlated with both body weight and age, described by: Y = 1.97 + 0.21 . x1 + 0.06 . x2, where Y is the thyroid volume (milliters), x1 is the body weight (kilograms), and x2 is the age (years). The influence of body weight on the thyroid volume was about 3 times that of age. The difference in thyroid gland volume between males and females was explained solely by a difference in body weight.

Adolescent↗
PubMed1982

Thyroid-stimulating immunoglobulins in Hashimoto's thyroiditis measured by radioreceptor assay and adenylate cyclase stimulation and their relationship to HLA-D alleles.

The relationship between thyroid-stimulating immunoglobulins, measured by both radioreceptor assay and adenylate cyclase stimulation, and the HLA alleles was studied in 41 patients with Hashimoto's thyroiditis. TSH binding-inhibiting immunoglobulins (TBII) were detected in 9 (22%) patients, and human thyroid adenylate cyclase-stimulating immunoglobulins (HTACS) were found in 21 (51%) patients. Only 2 patients were positive in both assays, and an inverse relationship was observed between TBII and HTACS. In the 21 HTACS-positive patients, HLA-Dw5 was only found in 1 subject, compared to 8 of the 20 HTACs-negative patients (P less than 0.01), while 4 of the 9 TBII-positive patients had HLA-Dw5 compared to 5 of the 32 TBII-negative subjects (P = -0.09). No significant relations were observed between the presence of HTACS or TBII and HLA-Dw3 or HLA-B8. It is concluded, that TBII and HTACS are produced independently in Hashimoto's thyroiditis, and that the production of these autoantibodies seems to be related to the HLA-D region in this disease.

Adenylyl Cyclases↗
PubMed1982

131I treatment of diffuse and nodular toxic goitre with or without antithyroid agents.

The results of 131I treatment in combination with pre- and post-treatment with carbimazole (n = 122) were compared to the results of 131I used as the only antithyroid treatment (n = 203). The two groups of patients were fully comparable in regard to age, size of goitre and time of observation, and the same diagnostic criteria and dosage regimen of 131I were used. The incidence of early myxoedema in patients with diffuse goitre was significantly reduced after combination therapy, 5 per cent, compared to 16 per cent after 131I as the only antithyroid therapy (P less than 0.05). The incidence of late myxoedema was 6 per cent in both groups 3 years after the last treatment, and fully compensated myxoedema was found in 13 and 22 per cent (n.s.). No severe acute side effects were observed after 131I therapy in any of the two groups. It is concluded that--in diffuse toxic goitre--a lower early incidence of myxoedema was obtained on the combined regimen because of either a possibly lower absorbed radiation dose or a more fractionate therapy. A major advantage of the combination therapy is also, that the patients are rendered euthyroid shortly after the diagnosis and remain so during the prolonged period of treatment. 131I treatment in combination with carbimazole is advocated in all patients with diffuse and nodular toxic goitre if the patient is above fertile age and thyroidectomy is not indicated.

Adenoma↗
PubMed1980

Propylthiouracil in human milk. Revision of a dogma.

Propylthiouracil (PTU) concentrations were measured in blood and milk from nine lactating women after oral administration of 400 mg of PTU. 1 1/2 h after PTU ingestion mean serum-PTU reached 7.7 microgram/ml and the mean concentration of PTU in milk reached only 0.7 microgram/ml. The mean total amount of PTU excreted during 4 h was 99 microgram--i.e., 0.025% of the administered dose. One of the suckling babies was studied for 5 months during which the mother received 200-300 mg of PTU daily: there were no changes in any of the thyroid parameters. PTU is not concentrated in human breast milk and recommended dosages to the mother result in minimal and presumably clinically insignificant doses to the suckling infant.

Adult↗
PubMed1979

Mechanisms of edema formation in myxedema--increased protein extravasation and relatively slow lymphatic drainage.

We assessed extravascular accumulation of albumin and fluid in primary myxedema by measuring metabolic turnover and transcapillary escape of 131I-labeled human albumin in seven patients. In the hypothyroid state, we found a low plasma volume (P less than 0.05), a reduced rate of albumin synthesis and catabolism (P less than 0.01), an increased transcapillary escape rate of albumin (P less than 0.01), a remarkable increase in the extravascular mass of albumin (1500 micronmol; P less than 0.01) and a longer mean transit time through the extravascular spaces in primary myxedema than in other states of generalized edema (P less than 0.05). All variables returned to normal during l-thyroxine treatment. The extravascular accumulation of albumin, and presumably of all other plasma proteins, is important in the generalized edema typically found in myxedema. Inadequate lymphatic drainage may also explain the formation of exudates in the serous cavities that are well known in myxedema.

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 effect of suppressive therapy of nontoxic diffuse goiter on serum levels of thyroxine, 3,5,3'-triiodothyronine and 3,3',5'-triiodothyronine.

We studied the effect of suppressive therapy with graded doses of thyroxine (T4) on serum levels of T4, 3,5,3'-triiodothyronine (T3) and 3,3',5'-triiodothyronine [rT3] in patients with diffuse, nontoxic goiter. For comparison and in order to elucidate the degree of suppression of the pituitary thyroid axis by T3 the effect of suppressive therapy with T3 was studied in the same type of patients. We found that T4 in serum rose significantly to a constant level during T4 treatment (0.10, 0.15 and 0.20 mg/day). Dose-related rises in T4 were only seen after 3 months of treatment. T3 and rT3 only changed minimally. The T4/T3 ratio rose to a constant level during the initial 3 months of treatment. T3/rT3 ratio remained unchanged. No dose-related differences in T4/T3 and T3/rT3 ratio were observed. Treatment with T3 in doses of 0.06 mg per day caused a significant but slow fall in T4 and rT3 to hypothroid levels while T3 only rose slightly. The T4/T3 ratio dropped significantly during T3 therapy.

Adult↗
PubMed1979

The effect of repeated intramuscular gonadotrophin-releasing hormone injections on luteinizing hormone, follicle-stimulating hormone, testosterone, oestrogens, dehydroepiandrosterone and dehydroepiandrosterone sulfate in normal men.

The endocrine response to three daily intramuscular injections of 500 microgram LH-RH was measured in 9 normal men during a period of 3 days. A marked but declining response in LH was seen in addition to a significant increase in the serum concentration of FSH, testosterone, oestradiol and the urinary excretion of oestrogenic substances. No change could be demonstrated in the DHA, DHAS or cortisol secretion which confirms our previous results of a direct effect of clomiphene on adrenal steroidogenesis.

Adrenal Cortex↗
PubMed1979

Kinetics of propylthiouracil in the elderly.

The pharmakokinetics of propylthiouracil was evaluated in 9 elderly patients and compared to previous results from 6 younger subjects. By giving the drug both by the intravenous and oral route of administration it was possible to estimate the rate and extent of bioavailability. The various kinetic parameters were calculated according to a two-compartment model by use of two different methods: a graphical hand drawn one and by a special developed computer program based on a least squares minimalisation. While no significant differences could be demonstrated between the two age groups concerning volumes of distribution, clearance and extent of absorption, a large difference was found with regard to the absorption rate constant ka, which was about 3 times higher in the younger than in the elderly subjects, presumably due a reduced gastric emptying time. Considering the comparison between the two methods of calculations all the kinetics parameters were similar except ka and the slow disposition rate constant betw which were underestimated by the graphical method. It is concluded that no-age dependent changes exist concerning the kinetics of propylthiouracil except for a decreased rate of absorption. Graphical methods in pharmacokinetics are useful in obtaining distribution and elimination data but seem often biased for the evaluation of absorption rate constants.

Age Factors↗
PubMed1979

The effect of different sulfonamides on phenytoin metabolism in man.

The influence on the metabolism of phenytoin of some sulfonamides given in common clinical doses has been studied. In single dose experiments sulfaphenazole increased phenytoin half-life (T/2) by 237% and decreased phenytoin metabolic clearance rate (MCR) by 67%. Sulfadiazine, sulfamethiazole, sulfamethoxazole + trimethoprim and trimethoprim increased phenytoin T/2 by 80, 66, 39 and 51% respectively, and decreased phenytoin MCR by 45, 36, 27 and 30% respectively. Sulfamethoxazole gave a small but significant increase in phenytoin T/2 but not a corresponding fall in phenytoin MCR. No changes were found in phenytoin T/2 and MCR after treatment with sulfamethoxypyridazine, sulfadimethoxine and sulfamethoxydiazine. Steady state experiments confirmed the findings of the single dose experiments. It is suggested that sulfaphenazole, sulfadiazine, sulfamethizole, sulfamethoxazole + trimethoprim and trimethoprim inhibit hepatic metabolism of phenytoin.

Adult↗
PubMed1979

L-thyroxine treatment of diffuse non-toxic goitre evaluated by ultrasonic determination of thyroid volume.

The effect of a daily dose of 150 micrograms l-thyroxine for one year was studied in forty-five patients with diffuse non-toxic goitre. Thyroid volume was evaluated by ultrasonic scanning. A decrease in the median value of the thyroid volume of about 20% was found after 3 months of therapy and no further change in the median value was observed in the following 9 months of treatment. About 50% of the patients showed a response to therapy and about 30% obtained normal size of the thyroid gland. Median value of the thyroid volume returned to pretreatment value 3 months after thyroxine therapy was stopped. A considerable increase in serum T4 and free T4 index was noted after 3 months of therapy and these elevated values persisted unaltered during the following 9 months of treatment. Serum T3 was studied before and after 3 months of thyroxine therapy in eleven of the patients. A small and insignificant increase in serum T3 and free T3 index was observed.

Adult↗
PubMed1979

Effect of exercise on thyroid parameters and on metabolic clearance rate of antipyrine in man.

UNLABELLED: Serum concentrations of thyroxine, triiodothyronine, free-thyroxine-index, free-triiodothyronine-index and reverse-triiodothyronine (r-T3) were followed in nine normal men, aged 18 to 22 years, during a nights rest and during nine hours march (4.6 km/h). In addition antipyrine elimination was measured in the same periods after iv injection of 1 gram of antipyrine. No significant differences were found in any of the thyroid parameters during exercise except for a small increase in serum r-T3 after 3 hours. During rest a small but significant decrease was found in serum r-T3. Otherwise no significant differences were found except for a significant increase in free-T3-index after 3 hours rest. The mean value of total body clearance of antipyrine was identical at rest and during exercise. IN CONCLUSION: Prolonged exercise does not change the metabolic clearance rate of antipyrine and does not elicit any major change in the serum concentrations of the thyroid hormones.

Adolescent↗