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Biomedical subjects

N Demeester-Mirkine

Publications and source records attributed to N Demeester-Mirkine.

At least 19 recordsLinked to original sources
PubMed1992

Hypocalcemia after thyroidectomy.

Serum calcium, sodium, potassium, chloride, magnesium, phosphorus, osmolarity, total protein, albumin, parathyroid hormone, and calcitonin values were systematically surveyed in 135 patients who underwent thyroidectomy and in 104 control surgical patients. A transient and moderate hypocalcemia developed after operation in thyroidectomized and control patients. Concentrations of other electrolytes, osmolarity, proteins, and albumin followed the same pattern of evolution. After thyroidectomy, the degree and duration of hypocalcemia increased with the extent of thyroid resection. A profound hypocalcemia (less than 2.0 mmol/L) and a marked reduction of the parathyroid hormone concentration (below normal) were present in 12% and 8% of cases after subtotal thyroidectomy and in 22% after total thyroidectomy. Calcitonin values did not increase after thyroidectomy. A slight correlation was observed between the preoperative serum alkaline phosphatase level and the minimal postoperative serum calcium level. It is concluded that post-thyroidectomy hypocalcemia is a multifactorial phenomenon. It is due, at least in part, to hemodilution. A temporary parathyroid insufficiency after subtotal and total thyroidectomy, and an avidity of the skeleton for calcium in hyperthyroid patients, may aggravate the hypocalcemia.

Adolescent↗
PubMed1990

Calcitonin and bone mass status in congenital hypothyroidism.

Calcitonin (CT) deficiency and its possible repercussions on bone mass were studied in a group of 9 adult patients (7 females, 2 males) with congenital hypothyroidism of dysgenetic origin. Using a new extraction method (exCT) which considerably improves the sensitivity and the specificity of the assay for CT-monomer, we measured CT levels before and after a short calcium (Ca) stimulation test (2 mg Ca/kg over 5 minutes) to evaluate C-cell secretory reserve. Mean basal plasma CT concentrations were lower in the hypothyroid women (mean +/- SEM: 0.6 +/- 0.1 pg/ml) than in 30 normal female controls (1.7 +/- 0.2 pg/ml, P less than 0.001). Serum calcium increased similarly in the two groups, but postinfusion CT levels were lower in the hypothyroid women, (1.7 +/- 0.2 pg/ml) than in normal women (16.8 +/- 2.9 pg/ml), P less than 0.001. Hypothyroid women showed a 10% reduction in bone mineral content at the diaphyseal site in the radius, 0.840 +/- 0.037 g/cm, compared with normal age-matched controls, 0.930 +/- 0.020 g/cm, (P less than 0.05). Our study demonstrates the existence of a profound CT-monomer deficiency in adult patients with thyroid agenesis or dysgenesis. Both calcitonin deficiency and thyroid hormone treatment could play a role in the observed bone loss. Attention should therefore be paid to bone metabolism during treatment of congenital hypothyroidism to avoid further bone loss.

Adolescent↗
PubMed1990

[Value of echography for measuring the volume of the thyroid and its lesions].

The sizes of thyroid lobes and lesions estimated by ultrasonography have been compared to surgical specimens in 92 cases of thyroid pathology. Volumes can be calculated with a reasonable accuracy for parenchymatous and cystic lesions from measurements of their diameters when considered as ellipsoids. This easy method, currently used by ultrasonographers, is however unsatisfactory for estimation of the volumes of thyroid lobes. More reliable results are obtained by computation of volumes from planimetry of cross-sections through the gland.

Humans↗
PubMed1986

Calcitonin deficiency in primary hypothyroidism.

The relative lack of sensitivity and specificity of current assays for plasma calcitonin (CT) have made it difficult to study possible CT deficiency conditions. Using a new extraction method that considerably improves the sensitivity of the assay for CT monomer, CT levels were measured before and after a short calcium (Ca) stimulation test (2 mg Ca/kg over 5 min) to determine C-cell secretory reserve in women with autoimmune primary hypothyroidism and normal women. Mean basal plasma CT concentrations were lower in the hypothyroid women [0.9 +/- 0.1 (+/- SEM) pg/ml] than in the normal women (1.5 +/- 0.2 pg/ml; P less than 0.01). Serum Ca increased similarly in both groups, but postinfusion CT levels were lower in the women with primary hypothyroidism (3.8 +/- 1.3 pg/ml) than in normal women (15.9 +/- 3.0 pg/ml; P less than 0.001). The functional thyroid status at the time of the study did not influence CT levels; both hypothyroid patients (n = 10) and patients who were euthyroid during T4 treatment (n = 11) were CT deficient to the same extent. Unlike that in primary hypothyroidism, CT secretion was normal in four patients with hypothyroidism of pituitary origin. We conclude that the process that causes hypothyroidism in patients with autoimmune thyroid disease can also cause marked CT deficiency. This first demonstration of spontaneous CT deficiency in adults should contribute to the understanding of CT physiology; it also suggests that bone metabolism should be closely monitored during the treatment of primary hypothyroidism.

Calcitonin↗
PubMed1979

Disturbed mineral metabolism in hyperthyroidism: good correlation with tri-iodothyronine.

Mineral metabolism is frequently disturbed in hyperthyroidism. In a group of seventy-two patients with hyperthyroidism, we observed an increase in serum diffusible calcium in 50% of the cases, elevated inorganic phosphorus in 30% and elevated alkaline phosphatase in 44% of the cases. Correlations existed between the values of diffusible calcium, inorganic phosphorus, alkaline phosphatase and certain indices of thyroid function (T4, FT41, T3, FT3I), of which that with T3 was the best (P less than 0.001). Our results suggest that the magnitude of the disturbances of mineral metabolism depends on the severity of the hyperthyroidism and that it is the T3 level that constitutes the best index of that severity.

Adolescent↗
PubMed1978

Urinary cyclic AMP in hyperthyroidism.

Urinary cyclic AMP was studied in 22 female and in 6 male hyperthyroid normocalcemic patients and in 3 hyperthyroid hypercalcemic men. Cyclic AMP/creatinine ratios were elevated both in female (4.12 +/- 0.26 mumoles/gm creatinine) and male (3.92 +/- 0.41 mumoles/gm creatinine) hyperthyroid normocalcemic patients as compared with normal female and male controls (2.85 +/- 0.20 and 2.54 +/- 0.14 mumoles/gm creatinine, respectively). However, there was no difference in the 24-hour urinary cyclic AMP excretion of both hyperthyroid and normal subjects. The hyperthyroid hypercalcemic men excreted less (2.47 +/- 0.19) mumoles/24 hr) cyclic AMP/24 hr than the normal male controls. In the thirteen female patients, studied when euthyroid, the cyclic AMP/creatinine ratio was normalised.

Adult↗
PubMed1976

Comparative study of plasma cortisol evolution in TRH or placebo injected patients with or without thyroid disease.

The plasma cortisol evolution under TRH has been compared in 27 euthyroid, 12 hyperthyroid and 5 patients with hot nodules and in 15 control individuals receiving a placebo or sham injection. The results showed no statistical difference in plasma cortisol evolution between the groups, suggesting no influence of the thyroid status or TSH secretion on the spontaneous fall of cortisol level during the time of the test.

Clinical Trials as Topic↗
PubMed1976

Delayed adjustment of the pituitary response to variations in circulating thyroid hormones in a case of subacute thyroiditis.

In a case of subacute de Quervain thyroiditis characterized by a period of pronounced hypermetabolism followed by hypometabolism, levels of T4, T3 and the TSH response to TRH were repeatedly measured. As expected, the response to TRH was absent or low during the hypermetabolic phase, high during the hypometabolic phase and returned to normal with recovery. However, at the beginning and at the end of the hypometabolic phase, while circulating levels of T3 and T4 both lay in the subnormal range, two periods of inadequate response to TRH could be demonstrated. During the first period, the response to TRH was zero or very small; during the second period, stimulation by TRH was exaggerated. The response to TRH thus depends not only on the level of circulating thyroid hormones but on other factors such as the previous state of pituitary stimulation or inhibition.

Female↗
PubMed1975

[Value of the test using TRH in the exploration of thyroid diseases].

The discovery and the synthesis of the thyrotropin-releasing hormone (T.R.H.) has given rise to a new test able to explore the function of the thyroid and the pituitary. Intravenous injection of T.R.H. determines a short elevation of T.S.H. in the plasma. In hyperthyroidism and in hot nodules the response is abolished. In hypothyroidism, the response depends on the localization of the lesion: exaggerated response in thyroid lesions, diminished or abolished response in pituitary problems, delayed response in hypothalamic lesions. This new test will definitely have an important diagnostic role in difficult clinical problems.

Adrenal Cortex Hormones↗
PubMed1975

Urinary excretion of hydroxylysyl glycosides and thyroid function.

Urinary excretion of hydroxylysyl glycosides, two specific collagen metabolites, was measured in 18 patients with hyperthyroidism and 4 patients with hypothyroidism. As in the case of hydroxyproline, values were high in thyrotoxicosis and low in hypothyroidism. The glucosyl-galactosyl-hydroxylysine/galactosyl-hydroxylysine urinary ratio which indicates the bone or skin origin of degraded collagen was found to be unchanged in hyperthyroidism, except in two cases complicated with hypercalcemia where it was very low. This finding provides a further argument in favour of the bone origin of hypercalcemia in thyrotoxicosis.

Collagen↗
PubMed1975

Benign thyroid nodule with normal iodide trap and defective organification.

Cold thyroid nodules are generally due to impaired iodide uptake, while organification remains normal. In a case of a nodule appearing hot one hour after Tc99 m and cold 24 h after 131I-iodide, in vivo investigations showed that the trapping function was unimpaired and that the defect lay in organification. An early thyroid scan taken with 131I-iodide showed definite radioactivity in the nodule which was dischargeable by K perchlorate. This finding was confirmed by in vitro study of the tissue. Indirect evidence suggests that a defect was present in the H2O2 generating system rather than in peroxidase.

Adult↗