PubMed Health⌕ Search

Biomedical subjects

I Roiter

Publications and source records attributed to I Roiter.

14 recordsLinked to original sources
PubMed1992

Bone turnover in overt and subclinical hyperthyroidism due to autonomous thyroid adenoma.

Parameters of bone turnover were measured in 20 premenopausal women affected by autonomous thyroid adenoma: 7 patients were suffering from overt hyperthyroidism with raised values of free thyroid hormones; 13 were clinically euthyroid and had normal values of free thyroid hormones. In all cases serum TSH concentrations were below the lower normal limit of our laboratory (< 0.4 mU/l). Eleven healthy premenopausal women were studied as a control group. Patients with overt hyperthyroidism disclosed a significant enhancement of both bone resorption (increased serum calcium and urinary excretion of hydroxyproline) and bone formation (increased serum levels of osteocalcin and alkaline phosphatase) when compared both to controls and to patients with subclinical hyperthyroidism. No significant alterations of bone metabolism parameters were found in patients with subclinical hyperthyroidism in comparison with controls. Therefore, in premenopausal women affected by autonomous thyroid adenoma the bone turnover appeared to be significantly increased when the serum values of free thyroid hormones were raised in the group of patients with overt hyperthyroidism.

Adenoma↗
PubMed1991

Increased serum beta 2-microglobulin concentrations in hyperthyroid states.

Serum beta 2-microglobulin concentrations were determined in 21 untreated hyperthyroid patients (12 with Graves' disease, and nine with toxic nodular adenoma) and in 20 healthy controls. All subjects had normal serum creatinine concentrations and urine analysis. Both total and free thyroid hormones were significantly higher in the hyperthyroid groups than in controls. Beta 2-microglobulin concentrations were significantly increased in both groups of hyperthyroid patients compared with controls. No difference was found in the thyroid hormone and beta 2-microglobulin concentrations between both sets of patients. The beta 2-microglobulin and thyroid hormone concentrations were not correlated. These data show that hyperthyroidism is another cause of increased beta 2-microglobulin production along with viral infections, immunologically mediated diseases, and malignant neoplasms. The increased serum beta 2-microglobulin concentration in thyroid hyperfunction is probably related to metabolic rate, even if autoimmunity might contribute to its overproduction.

Adenoma↗
PubMed1991

Clodronate treatment increases serum osteocalcin in normocalcemic osteolytic bone metastases.

28 consecutive patients with multiple osteolytic bone metastases due to various types of cancer were treated with 300 mg/day of sodium clodronate given intravenously as a 3-hour infusion, 16 patients were treated for 10 days and 12 for 20 days. Our findings showed that clodronate administration causes an increase in serum osteocalcin (sBGP) in the group of patients treated for 20 days (p less than 0.05), a reduction in serum Ca in both groups of patients (p less than 0.01), an increase in serum alkaline phosphatase (p less than 0.05 and p less than 0.01), a reduction in urinary Ca (p less than 0.01) and a reduction in uOHP (p less than 0.05). The raise in sBGP may be attributed to the reduction of sCa and to the consequent secondary hyperparathyroidism. The increase in sBGP can be considered as the expression of osteoblasts stimulation following an adequate period of therapy with sodium clodronate.

Adult↗
PubMed1990

Serum bone GLA-protein in hypercalcemia of primary hyperparathyroidism and malignancy.

Serum bone GLA-protein, a modern and sensitive marker of bone turnover, was measured in 15 patients with primary hyperparathyroidism, 18 patients with hypercalcemia of malignancy, 41 patients with bone metastasis without hypercalcemia, and 29 healthy subjects. Serum bone GLA-protein was increased in primary hyperparathyroidism (17.6 +/- 3.9 ng/ml) and normal in hypercalcemia of malignancy (5.2 +/- 2.8 ng/ml; p less than 0.001 vs hyperparathyroidism) and in normocalcemic patients with bone metastases. In primary hyperparathyroidism parathyroid hormone correlated positively with urinary calcium excretion (p less than 0.05) and with urinary hydroxyproline excretion (p less than 0.001). The sensitivity of serum bone GLA-protein measurements in differentiating between primary hyperparathyroidism and hypercalcemia of malignancy was 91% and the specificity 84%. Thus this marker appears to be a useful tool for the differential diagnosis of hypercalcemias.

Adult↗
PubMed1985

Hypercalcemia in malignancies: treatment with dichloromethylene diphosphonate (Cl2MDP).

Eleven hypercalcemic patients affected by various kinds of cancer were treated with dichloromethylene diphosphonate (Cl2MDP), 400 mg diluted in 500 ml of saline solution, i.v., during 3 h. Drug administration normalized plasma calcium levels in all treated patients, within 72 h for patients with lung cancer; within a longer period for other kinds of cancer. Moreover, Cl2MDP also reduced calciuria in treated patients. The use of the drug was not followed by side effects and was also well tolerated in patients with kidney insufficiency.

Adult↗
PubMedDate not supplied

[Beta-2-microglobulin in hyperthyroidism].

The aims of the study were to clarify the cause of increased serum beta 2-microglobulin as a marker of thyroid hyperfunction. Serum beta 2-microglobulin was measured in 31 untreated hyperthyroid patients, all of them with normal renal function. Twenty-one subjects were affected by diffuse toxic goiter and 10 by toxic adenoma. Serum free thyroid hormones, TSH, anti-thyroglobulin and anti-microsomal antigen autoantibodies were determined, too. Thyroid hormone and creatinine levels did not differed between both sets of patients. beta 2-microglobulin was higher than normal in 90% of cases with diffuse toxic goiter and in 70% of those with toxic adenoma (p less than 0.05), but mean beta 2-microglobulin concentrations didn't differ between the two groups. No difference was found in beta 2-microglobulin levels in diffuse toxic goiter group according to the presence or absence of autoantibodies. beta 2-Microglobulin and thyroid hormones were not correlated in either diffuse toxic goiter and toxic adenoma groups. These data confirm the high prevalence of elevated beta 2-microglobulin concentrations in hyperthyroidism. As renal function was normal, this rise is due to beta 2-microglobulin overproduction. This increased production is a hormone mediated effect, even if lymphocyte activation may contribute in diffuse toxic goiter. beta 2-microglobulin is not correlated with thyroid hormone concentrations so that at present it isn't a useful marker of hyperthyroidism severity for practical purposes.

Adenoma↗
PubMedDate not supplied

[Bone metabolism in primary hypothyroidism in the adult].

The aim of the study was to investigate bone metabolism in adult onset idiopathic myxedema. We studied 13 untreated patients (11 women and 2 men, age ranging 24-64 years) and, as a control group 15 healthy subjects (13 women and 2 men, age ranging 24-64 years). The hypothyroid group had significantly lower urinary excretion of hydroxyproline (4.40 +/- 0.63 vs. 8.60 +/- 1.3 mg/g, p less than 0.05) and serum concentration of osteocalcin (4.45 +/- 0.41 vs. 7.76 +/- 0.55 ng/ml, p less than 0.001). This low urinary excretion of hydroxyproline points to reduced osteoclastic bone resorption, while the low serum level of osteocalcin supports the view that osteoblastic bone formation is sluggish, too. Therefore bone metabolism in adult myxedema is characterized by a general reduction of remodelling. The stimulating actions of thyroid hormones on both bone resorption and new synthesis are further supported by the positive correlations between free hormone fractions and either urinary hydroxyproline and serum osteocalcin. Serum calcium, phosphorus, urinary calcium and phosphorus, and serum calcitrophic hormones (vitamin D, calcitonin, parathyroid hormone, measured as intact molecule) did not differed between the two groups; this finding might be related to the low fraction of active bone in hypothyroidism. The slow bone turnover seems to have few clinical consequences, but replacement therapy might produce accelerated osteoporosis, perhaps as a result of bone hypersensitivity to thyroid hormones.

Adult↗
PubMedDate not supplied

[Serum osteocalcin in hyperthyroidism].

Several bone metabolism biochemical parameters were measured to evaluate the increased serum osteocalcin (sBGP) in hyperthyroidism. Twenty patients (19 women and 1 man, aged 22-69) and 20 age and sex-matched healthy subjects were examined. The following serum measurements were performed: calcium, phosphate, mid-molecule PTH, calcitonin, 25OH vitD, alkaline phosphatase, total and free thyroid hormones; urinary excretion of calcium, hydroxyproline and creatinine was also measured. The results (mean +/- standard error) show significant increases of sBGP (16.4 +/- 1.02 ng/mL; p less than 0.001), serum calcium (10.1 +/- 0.1 mg/dL; p less than 0.001), alkaline phosphatase (144.0 +/- 11.7 UI/L; p less than 0.001), urinary calcium (315.6 +/- 48.5 mg/g urinary creatinine; p less than 0.001) and hydroxyproline (43.0 +/- 6.1 mg/g urinary creatinine; p less than 0.001). A significant correlation between total and free thyroid hormones and sBGP was found. Accelerated bone turnover in hyperthyroid patients is therefore confirmed: both osteoclastic bone resorption, as suggested by increased serum and urinary calcium and urinary hydroxyproline, and osteoblastic bone formation, as suggested by increased serum osteocalcin and alkaline phosphatase, are stimulated.

Adult↗