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Biomedical subjects

C Bános

Publications and source records attributed to C Bános.

At least 37 records · Page 2Linked to original sources
PubMed1986

Arteriovenous shunt-circulation in lymphoedematous limbs.

In lymphoedema of the extremities arteriovenous shunt circulation develops. Regulation of limb circulation was studied in 28 cases of (primary and secondary) lymphoedema by using the venous isotope dilution method and technetium-macroaggregate perfusion scintigraphy. As a result of lymphoedema, limb circulation (total limb circulation) increases, arteriovenous O2 difference is low and the O2 uptake of the tissues is normal. The development of arteriovenous (micro-, and macro-) shunts can be directly visualized by perfusion scintigraphy. In lymphoedema of the extremities the nutritive--capillary--blood supply of the tissues remains normal and therefore, no trophic disturbances develop. Lymphoedema is often associated with a fairly considerable arteriovenous shunt circulation and, in such cases, the cardiac output as well as cardiac performance are enhanced.

Adult↗
PubMed1986

Serum-"free"-thyroxine and triiodothyronine levels: their significance in preclinical hyperthyroidism and subclinical hypothyroidism.

A study was performed to establish whether the serum-"free" T4 and T3 levels contributed to the diagnosis of latent thyroid disease. The results suggested that in case of autonomous adenoma an increase in the serum free T3-level is the most reliable indicator of the transformation of the thyroid nodule, and that this hormone concentration, in addition to the TSH--IRMA procedure contributed to the differentiation between euthyroid and hyperthyroid state. In subclinical hypothyroidism, regarded as a heterogeneous subgroup, the mean "free" T4 levels, though still within the normal range, were below those of the controls. Measurement of "free" T4 alone was, however, not sufficient for the diagnosis of subclinical hypothyroidism, but contributed to the differentiation of subclinical from manifest hypothyroidism. Subclinical hypothyroidism raised the possibility that a reduction in the serum hormone levels, though still within the normal limits, may be perceived by the peripheral tissues. Preliminary studies indicated that measurement of the systolic time interval may offer information on this issue.

Adult↗
PubMed1985

Effect of domperidone on serum TSH and growth hormone in thyroid patients.

In euthyroid female patients, the release of TSH from the pituitary increases in response to domperidone, a dopaminergic-receptor blocking agent of peripheral action. The rate of increase varies with the functional state of the thyroid, as confirmed by results obtained in cases of euthyroidism, primary hypothyroidism, subclinical hypothyroidism and subclinical hyperthyroidism. Observations suggest that the more vigorous feedback-mechanism modulates the dopaminergic regulation of TSH-secretion at a high degree of sensitivity. Stimulation with 1-dopa intensifies the release of growth hormone from the pituitary which is, however, of lesser degree in hyperthyroid or hypothyroid than in euthyroid individuals. The GH-response to 1-dopa is enhanced by administration of propranolol, but the maximum serum GH levels in response to stimulation with 1-dopa are significantly lower in hyperthyroid than in euthyroid individuals. Administration of domperidone leaves the serum GH levels unaffected in euthyroid and hyperthyroid subjects, but causes a significant increase in a number of patients with primary hypothyroidism. The results suggest that the dopaminergic system plays a part in the regulation of TSH and GH secretion, asserting itself partly as a direct effect on the pituitary, and that the dopaminergic regulation may be affected by thyroid dysfunction.

Adult↗
PubMed1984

Effect of body posture on the serum potassium response to glucose in healthy subjects, diabetics and hyperthyroid patients.

Administration of glucose induces normally a decrease in serum potassium, though exceptionally a paradoxcial increase (PGIH) may occur. The effect of posture on glucose-induced serum potassium changes in health and disease has not been previously studied. We have investigated the influence of changes in body posture on the different serum potassium responses to glucose in various groups of 47 subjects. We have found a smaller decrease in serum potassium in the upright position than in the recumbent one in 20 healthy subjects and in 12 non-insulin dependent diabetics, but no significant difference in hyperthyroidism. The variable effect of posture on glucose-induced insulin secretion in the various groups of subjects did not provide explanation for the postural inhibition of the normal serum potassium response to glucose. A tendency to PGIH was found in a small number of diabetics. Although PGIH was completely reversed by DOC the normal postural difference between serum potassium curves was uneffected. It was concluded that change in the body posture has a definite influence on the glucose-induced decrease in serum potassium in normal people and is not mediated by insulin and/or aldosterone; PGIH develops in the upright position more easily than recumbency; exact serum potassium changes after glucose loading can be explored only by adequate standardization and carrying out both recumbent and upright measurements.

Adult↗
PubMed1983

Serum calcitonin in hyperthyroidism.

The mineral content of the radius was found to be lower in thyrotoxic than in euthyroid women, particularly in the case of elevated serum triiodothyronine levels. On examining the hormones influencing bone metabolism, the basal serum calcitonin level of thyrotoxic patients was identical with that of the controls. The Ca and calcitonin responses to i.v. Ca loading (3.64 mg CaCl2/kg/3 min) were identical in the euthyroid and hyperthyroid subjects. The results suggest that the calcitonin reserves in Graves' disease are normal and that the bone abnormalities typical of this disease are unrelated to any change in calcitonin secretion. The serum calcitonin levels of patients with subacute thyroiditis were identical with those of the controls. An acute fall in the serum calcitonin level occurred in hyperthyroidism, after radioiodine therapy a finding which might be connected with the high radiosensitivity of the parafollicular cells and with a consecutive impairment of calcitonin production.

Adult↗
PubMed1983

Effect of 131I therapy on serum calcitonin levels in patients with Graves' disease.

In a group of patients suffering from Graves' disease a transitory fall of serum calcitonin levels and an increase of triiodothyronine concentrations could be detected after 131I therapy. The transient decrease of the calcitonin values might be related to the high radiosensitivity of the parafollicular cells and to a consecutive impairment of calcitonin production, while the rise of triiodothyronine secretion could be explained by the radiation-induced destruction of the thyroid gland. The drop of serum calcitonin levels lasted for a short period only and did not affect serum Ca concentrations, thus the assumption is highly improbable that the temporarily altered calcitonin secretion involves late consequences for the skeletal system after 131I therapy.

Calcitonin↗
PubMed1982

Glucose-induced hyperkalemia developing in the upright position in captopril-treated hypertensives.

Paradoxical glucose-induced hyperkalemia (GIH) was elicited exclusively in the upright position during captopril treatment in four hypertensive patients (Group 3) without impaired glucose tolerance in three. Inhibited aldosterone production and inappropriate plasma aldosterone responses to increasing serum potassium may have been responsible for the captopril potentiated GIH. Similar GIH was found in four non-insulin dependent diabetic control patients with mineralocorticoid insufficiency (Group 1) but without captopril treatment, which could be prevented by desoxycorticosterone. Normal serum potassium responses to glucose, uninfluenced by desoxycorticosterone were shown in four untreated hypertensive control patients (Group 2).

Adolescent↗
PubMed1982

Functional relationships of the hypothalamic-pituitary-testicular system in Graves' disease.

An increased secretion of gonadotropic hormone was found in hyperthyroid males despite the high basal serum total testosterone and oestradiol levels. This suggests that hyperthyroidism affects the responsiveness of the hypothalamic-pituitary axis to sexual steroid hormones. While in the hyperthyroid patients the elevation of the serum testosterone level in response to chorionic gonadotropin was lower than normally, the LH and FSH responses to LRH were increased. The results indicate that male hyperthyroidism is associated with a loss of responsiveness of the Leydig-cells to adequate stimuli, to which the pituitary reacts by a compensatory increase in its LH-secretion and by an increased reactivity to LRH. It is suggested that in addition to the direct effect of the increased thyroid hormone levels, a secondary elevation of the oestradiol concentration plays a major part in the alterations in question.

Adult↗