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Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of different calcium concentrations as well as dibutyryl-cyclic adenosine 3',5'-monophosphate (DB-cAMP) on the secretion of parathyroid hormone by human parathyroid adenomas taken from patients with primary hyperparathyroidism (pHPT) was studied in organ culture. Their influence on the release of hormone was determined. The tissue was incubated in culture medium for 4 h; the medium was changed hourly and analyzed for immunoreactive parathyroid hormone (PTH) by radioimmunoassay. The hormone secretion showed an inverse relationship to different calcium concentrations in the medium and could be stimulated independently of the calcium concentration by adding DB-cAMP. These results suggest that the examined parathyroid adenomas are sensitive to physiological stimuli.
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PMID:The effect of calcium and dibutryl-cAMP on the secretion of parathyroid hormone by human parathyroid adenomas in organ culture. 19 45

A parathyroid adenoma is reported in a girl aged 12 years in whom hypercalcaemia was discovered by chance. Investigation of calcium metabolism suggested the diagnosis of hyperparathyroidism and studies of the urinary cyclic AMP and determination of the plasma parathyroid hormone concentration further added to the evidence. The diagnosis of parathyroid adenoma was made after determination of the parathyroid hormone concentration at various sights during selective catheterization of the tyroid veins. This was confirmed at surgery. In this patient the place of catheterization of the inferior thyroid veins in the early diagnosis of primary hyperparathyroidism is discussed.
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PMID:[A symptomatic parathyroid adenoma. Value of parathyroid hormone determination through selective catheterization of the thyroid veins]. 19 45

Six patients with primary hyperparathyroidism (PHPT) and one with squamous cell carcinoma of the esophagus with parathyroid hormone excess received disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) at a daily dose of 20 mg/kg orally. During treatment, the decrease in urinary calcium, total urinary hydroxyproline, and fasting urinary calcium suggested an inhibition of bone resorption. Serum calcium intestinal absorption of calcium and urinary cyclic adenosine monophosphate (cAMP) did not change significantly. This preliminary study indicates a possible role of diphosphonates in the management of inoperable cases of primary hyperparathyroidism or pseudohyperparathyroidism.
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PMID:Metabolic effects of diphosphonate in primary hyperparathyroidism. 19 83

Nephrogenous cyclic AMP (NcAMP), total cyclic AMP excretion (UcAMP), and plasma immunoreactive parathyroid hormone (iPTH), determined with a multivalent antiserum, were prospectively measured in 55 control subjects, 57 patients with primary hyperparathyroidism (1 degrees HPT), and 10 patients with chronic hypoparathyroidism. In the group with 1 degrees HPT, NcAMP was elevated in 52 patients (91%), and similar elevations were noted in subgroups of 26 patients with mild (serum calcium </=10.7 mg/dl) or intermittent hypercalcemia, 19 patients with mild renal insufficiency (mean glomerular filtration rate, 64 ml/min), and 10 patients with moderate renal insufficiency (mean glomerular filtration rate, 43 ml/min). Plasma iPTH was increased in 41 patients (73%). The development of a parametric expression for UcAMP was found to be critically important in the clinical interpretation of results for total cAMP excretion. Because of renal impairment in a large number of patients, the absolute excretion rate of cAMP correlated poorly with the hyperparathyroid state. Expressed as a function of creatinine excretion, UcAMP was elevated in 81% of patients with 1 degrees HPT, but the nonparametric nature of the expression led to a number of interpretive difficulties. The expression of cAMP excretion as a function of glomerular filtration rate was developed on the basis of the unique features of cAMP clearance in man, and this expression, which provided elevated values in 51 (89%) of the patients with 1 degrees HPT, avoided entirely the inadequacies of alternative expressions. Results for NcAMP and UcAMP in nonazotemic and azotemic patients with hypoparathyroidism confirmed the validity of the measurements and the expressions employed.
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PMID:Nephrogenous cyclic adenosine monophosphate as a parathyroid function test. 19 23

The urinary excretion of adenosine 3', 5'-monophosphate (cAMP) was investigated in 15 subjects with primary hyperparathyroidism prior to parathyroidectomy and in 13 of them also after the operation. In comparison with healthy control subjects the cAMP excretion was raised in 8 of the patients pre-operatively and after operation all values had become normal. The discriminatory value of the cAMP analyses seemed to be increased by relating the cAMP values to the urinary excretion of calcium. With the applied methods determination of urinary cAMP was superior to a radioimmunoassay of parathyroid hormone in recognizing patients with primary hyperparathyroidism. In normal subjects it appeared that the cAMP excretion expressed per gram creatinine was somewhat higher in women than in men.
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PMID:Urinary excretion of cyclic AMP in hyperparathyroidism. 20 93

A sensitive radioreceptor assay for 1alpha,25-dihydroxyvitamin D3 (1alpha,25-(OH)2D3) is utilized to quantitate the circulating concentration of this sterol in experimental animals and humans. When weanling rats are grown for 2 weeks on low calcium or low phosphate diets, limited availability of either ion elicits a five-fold increase in the plasma level of 1alpha,25-(OH)2D3. The enhancement of 1alpha,25-(OH)2D3 in calcium deficiency is dependent upon the presence of the parathyroid and/or thyroid glands, which is consistent with parathyroid hormone (PTH) mediation of this effect. In contrast, the response to phosphate deficiency is independent of these glands and may result from a direct action of low phosphate on the renal synthesis of 1alpha,25-(OH)2D3. Studies in humans indicate that the normal level of 1alpha,25-(OH)2D is 2.1--4.5 ng/100 ml plasma. Patients with chronic renal failure have markedly lower circulating 1alpha,25-(OH)2D and this kidney hormone is undetectable in anephric subjects, but returns to normal within 1 day after successful renal transplantation. Hypoparathyroidism and pseudohypoparathyroidism are associated with reduced plasma 1alpha,25-(OH)2D while patients with primary hyperparathyroidism have significantly elevated sterol hormone levels. Thus, from measurements in rats and humans, it appears that circulating 1alpha,25-(OH)2D3 is regulated by PTH and/or phosphate and that abnormal plasma 1alpha,25-(OH)2D3 is a part of the pathophysiology of renal osteodystrophy and parathyroid disorders.
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PMID:The assay of 1alpha,25-dihydroxyvitamin D3: physiologic and pathologic modulation of circulating hormone levels. 21 27

On the basis of a dramatic hypercalcemia revealed by digestive and neuropsychic symptoms and related to a primary hyperparathyroidism, the authors recall all the clinical circumstances which should lead to determination of plasma calcium as well as the clinical and biological particularities which, in front of a hypercalcemia, suggest a primary hyperparathyroidism. The stress the usefulness and the limits of the dosage of plasma immunoreactive parathyroid hormone as well as the difficulties to differentiale primary from paraneoplasic hyperparathyroidism. The recent pathophysiological concepts of malignant hypercalcemia reviewed.
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PMID:[Primary hyperparathyroidism. Current aspects of its diagnosis apropos of a case with digestive and neuropsychiatric manifestations]. 21 10

In man, the total amount of cyclic AMP (cAMP) excreted in urine is derived from (a) the filtered load of the nucleotide and (b) cAMP formed de novo in the kidney (nephrogenous cAMP, NcAMP). NcAMP is the only pool of the nucleotide easily quantified in vivo and appears to provide a specific index of the effects of circulating, active parathyroid hormone. Elevated values for NcAMP (4.64 +/- 1.95 nmol/100 ml GF, mean +/- SD) were found in 90% or more of 115 patients with primary hyperparathyroidism, and low values (0.31 +/- 0.16 nmol/100 ml GF, mean +/- SD) were noted in 41 individuals with absent or suppressed parathyroid function. When properly expressed (as a function of glomerular filtration rate), results for the total cAMP excretion provided similar findings. The measurement of NcAMP provides a sensitive index of parathyroid function over the entire range of parathyroid activity and has proven to be an optimal method for assessing parathyroid suppressibility in response to intravenous or oral calcium administration. These techniques, the 'calcium injection test' and the 'oral calcium tolerance test', are useful in evaluation a number of subtle disorders of calcium metabolism.
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PMID:Nephrogenous cyclic AMP as a parathyroid function test. 22 May 48

The question of parathyroid autonomy in primary hyperparathyroidism has been the subject of conflicting immunoassay data. We studied the effects of calcium infusion (12 mg/kg/3h) and calcium injection (3 mg/kg/10 min) on peripheral plasma parathyroid hormone (iPTH) determined with a multivalent antiserum and on the excretion of nephrogenous cyclic AMP in normal subjects and in 7 patients with primary hyperparathyroidism who displayed only mild, intermittent hypercalcemia. In control subjects, calcium administration resulted in small (13-20%) reductions in iPTH, whereas some 4/5 (77-81%) of the nephrogenous cyclic AMP was rapidly and uniformly suppressed. In the patients with primary hyperparathyroidism, both analyses revealed a lack of absolute parathyroid autonomy in response to calcium, with overlapping iPTH responses between a majority of the patients and the control group. In contrast, the nephrogenous cyclic AMP responses provided a clear separation of the 2 groups after both calcium infusion and calcium injection (mean values for both studies, patients: 2.93 nmol/100 ml GF vs. normal sugjects: 0.38 nmol/100 ml GF), and measurements of total cyclic AMP excretion also clearly distinguished the 2 groups. When a sensitive antiserum with predominantly carboxy-terminal reactivity was employed, the iPTH responses to calcium injection provided an improved separation of patients and normal subjects. The data suggest that 1) although parathyroid autonomy is not, in general, a feature of primary hyperparathyroidism, abnormal parathyroid suppressibility is easily demonstrated even in patients with a subtle form of the disorder; 2) the determination of nephrogenous cyclic AMP provides an optimal method for assessing rapid changes in parathyroid function; and 3) the interpretation of iPTH results from such studies is dependent on a number of technological features of the assay employed.
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PMID:Effects of the intravenous administration of calcium on nephrogenous cyclic AMP: use as a parathyroid suppression test. 22 21

Urinary cyclic AMP excretion and plasma parathyroid hormone(PTH) levels were examined in three patients with primary hyperparathyroidism before and after parathyroidectomy. Plasma PTH and urinary cyclic AMP in the individual patients decreased in parallel following parathyroidectomy. During surgery there was a statistically significant correlation between PTH levels and cyclic AMP excretion in individual patients. These findings support the claim that the rate of urinary cyclic AMP excretion reflects endogenous PTH activity in patients with primary hyperparathyroidism.
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PMID:Changes of urinary cyclic AMP excretion and plasma parathyroid hormone levels before and after parathyroidectomy in patients with primary hyperparathyroidism. 22 81


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