Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate whether parathyroid hormone-related protein (PTHrP), a hypercalcemia-inducing factor responsible for malignancy-associated hypercalcemia (MAH), is excreted into urine of these patients, radioimmunoassay was established using antiserum specific for the C-terminal region of PTHrP-(127-141). Immunoreactive PTHrP (iPTHrP) was detected in the urine of all patients with MAH (n = 6) in whom nephrogenous cyclic AMP excretion was elevated. However, iPTHrP was not detected in the urine of normal subjects (n = 25) or hypercalcemic patients with primary hyperparathyroidism (n = 8). In normocalcemic patients with malignant disorders iPTHrP was not detected in the urine in most cases (24 of 25 patients) but was detectable in 1 of 25 patients. iPTHrP was also detected in the urine of hypercalcemic nude mice transplanted with PTHrP-producing tumors, but not in the urine of control and normocalcemic nude mice transplanted with PTHrP-nonproducing tumor. Furthermore, size-exclusion high-performance liquid chromatography revealed that the molecular weight of iPTHrP is about 2000-6000 daltons in the urine of patients as well as tumor-bearing nude mice. These data indicate that the fragments of the C-terminal region of PTHrP are excreted into the urine of patients with MAH and in a few normocalcemic patients with malignancies, suggesting that the measurement of iPTHrP in the urine is potentially useful in the differential diagnosis of hypercalcemia, particularly in differentiating humoral hypercalcemia of malignancy and primary hyperparathyroidism.
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PMID:Urinary excretion of parathyroid hormone-related protein fragments in patients with humoral hypercalcemia of malignancy and hypercalcemic tumor-bearing nude mice. 204 34

In a prospective study of 20 patients with primary hyperparathyroidism the diagnostic value of the intact parathormone assay was compared with that of intermediate fragment measurement and that of nephrogenic cyclic AMP determination. In the basal state, measuring the intact parathormone is the best way of separating hyperparathyroid patients form normal subjects. During calcium infusion tests, there is good concordance between changes in intact parathormone and in nephrogenic cyclic AMP. In addition, the intact parathormone assay enables a thorough study of the relationship between ionized calcaemia and parathyroid secretion to be performed and confirms the existence, in hyperparathyroid patients, of two types of secretory response to a rise in calcaemia. Being more reliable than the measurement of a C-terminal or intermediate fragment and easier to perform than nephrogenic cyclic AMP determination, the intact parathormone assay seems to be particularly suitable for the study of primary hyperparathyroidism.
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PMID:[Primary hyperparathyroidism: value of "intact parathormone" assay (PTH 1-84)]. 255 72

The authors analyze clinical and laboratorial features of 13 patients with surgically confirmed primary hyperparathyroidism (HPT). Among them, 8 presented renal lithiasis, 7 had bone disease, and 2 had both. All patients were hypercalcemic and had elevated serum carboxyterminal levels of PTH. The aminoterminal portion of the PTH was above the normal range in 9 patients and inappropriately high for the level of serum calcium in other two. The c'AMP was elevated in 7/8 patients. Hypophosphatemia was detected in 8/11 patients. Among the lithiasic patients, hypercalciuria was found in only 3. Five patients were submitted to an oral calcium load test which detected no intestinal hyperabsorption of calcium (IH) secondary to HPT in any of them. The rate of elimination of stones/patient/year was 1.7 before the establishment of HPT diagnosis. Despite the presence of renal lithiasis, hypercalciuria and IH were not common findings in HPT patients. Serum calcium and urinary c'AMP were the best screening tests for the diagnosis of HPT in this series. The diagnosis should be further confirmed determining the PTH.
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PMID:[Primary hyperparathyroidism: clinical and laboratory spectrum]. 264 May 6

Primary hyperparathyroidism is a common disorder and one that can usually (approximately 95%) be successfully treated by parathyroidectomy. PTH assays have become quite accurate for confirming the diagnosis. In patients with malignancy-associated hypercalcemia, parathyroid-like protein levels are usually increased, and radioimmunoassays being developed to quantitate serum levels of this protein will make the diagnosis easier. Treatment for a parathyroid adenoma is removal of the tumor and identification of the normal parathyroid glands. Treatment for primary or secondary hyperplasia is usually subtotal parathyroidectomy. Recurrent hyperparathyroidism is uncommon, except in patients with familial hyperparathyroidism, MEN-1 parathyroid carcinoma, or renal failure and secondary hyperparathyroidism. Persistent hyperparathyroidism is more common and is usually due to surgeon inexperience, but it is also caused by ectopically situated parathyroid glands, multiple abnormal parathyroid glands, or supranumerary parathyroid glands. Preoperative localization studies using ultrasound, thallium-technetium scanning, MRI, or CT scanning are reliable in patients with solitary parathyroid adenomas, but often fail to detect all of the abnormal parathyroid tissue in patients with multiple abnormal parathyroid glands. Intraoperative use of urinary cyclic AMP assays and rapid PTH assays have recently been used experimentally during parathyroid explorations to determine whether all hyperfunctioning parathyroid tissue has been removed, but these methods are not yet reliable or fast enough to be generally accepted. Most patients with primary hyperparathyroidism who are successfully treated by parathyroidectomy experience psychological, clinical, and metabolic benefits.
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PMID:Primary hyperparathyroidism. A surgical perspective. 267 68

The mechanisms of hypercalcemia were assessed in 15 patients with humoral hypercalcemia of malignancy (HHM) who had tumors at various stages of progression. In patients with early tumors, bone biopsies were generally normal and the hypercalcemia was due to an elevation in renal tubular resorption of calcium. Conversely, osteoclastic resorption was markedly increased in patients with advanced tumors, particularly those in whom the biopsies were obtained postmortem. Osteoclast surface (Oc.S) correlated positively with the stage of tumor progression (r = 0.80, p less than 0.002), degree of immobility (r = 0.87, p less than 0.002), and level of urinary cyclic AMP excretion (r = 0.60, p less than 0.02). When compared with a group of ambulant patients with primary hyperparathyroidism (HPT), osteoblast surface (Ob.S%) in HHM was depressed (median and range): 1.2% (0-11.6%) versus 5.3% (1.1-32.0%) (p less than 0.001). However, a relatively low Ob.S (4%) and raised Oc.S (43.5%) were also seen in an immobilized patient with severe HPT. These data suggest that the PTH-related peptides currently invoked in the pathogenesis of HHM may initially cause hypercalcemia by enhancing renal tubular calcium resorption. The increase in osteoclastic activity and depression of osteoblastic activity that subsequently occurs is probably due to the combined effects of immobilization and higher circulating levels of PTHrP on the skeleton. However, the release of other bone-resorbing factors by the tumor, which have a depressant effect on osteoblastic activity, remains possible.
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PMID:Contrasting mechanisms of hypercalcemia in patients with early and advanced humoral hypercalcemia of malignancy. 271 73

The diagnostic value of pre-operative laboratory tests and current imaging methods was evaluated in a series of 65 patients operated upon for primary hyperparathyroidism. Among laboratory tests, nephrogenous cyclic AMP and PTH serum levels had sensitivities of 100% and 71.7% respectively. Total urinary cyclic AMP and bone biopsy were much less reliable. Imaging procedures were mainly real-time ultrasonography and thallium-technetium substraction scintigraphy with sensitivities of 50.8% and 46.7% and specificities of 86.3 and 76.3% respectively. Failure of cervical exploration occurred in only one case and was attributed to an incorrect diagnosis (1.5%). Thus the selective use of these preoperative investigations may be envisaged in the following cases: hypercalcemic crises, highly probable PHP, uncertain PHP and in secondary surgical exploration.
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PMID:[Diagnosis and localization of primary hyperparathyroidism]. 282 47

The increase of nephrogenic cyclic AMP is an excellent index of parathyroid hypersecretion. A successful treatment of primary hyperparathyroidism results in a rapid fall in nephrogenic cAMP. In a series of 24 patients with proven primary hyperparathyroidism (hyperplasia 3, adenoma 21) and 2 patients with suspected hyperparathyroidism, the success of surgical excision was evaluated by measuring the urinary cAMP/urinary creatinine ratio (R), which in the absence of renal impairment, is proportional to the level of nephrogenic cAMP. Sequential assays of urinary cAMP and creatinine were performed during surgery; laboratory results were available within less than one hour. Among 22 patients with elevated baseline value or R, R became normal in 18 and decreased by more than 50% in 3; these findings suggested that the operation would be successful. In 1 case, R was not measured as the patient had impaired renal function. In another patient with normal baseline value of R, R did not significantly decrease after excision. Surgery failed in 1 patient, although the high value of R at the end of the operation should have prompted us to continue. Finally, in 2 patients the diagnosis was erroneous since R was lower than 0.5 as in controls. Surgeons, therefore, now have a reliable biochemical method at their disposal, but its use will be limited by its cost and complexity.
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PMID:[Surgery of primary hyperparathyroidism. Contribution of the peroperative assay of urinary cyclic AMP]. 282 56

To evaluate the cause of hypercalciuria, we carried out the oral calcium tolerance test before and after parathyroidectomy in a patient with primary hyperparathyroidism who had recurrent and multiple nephrolithiasis. Preoperative laboratory examination showed hypercalcemia, hypophosphetamia, hypercalciuria, decrease in % tubular reabsorption of phosphorus and strikingly elevated urinary cyclic AMP excretion. The oral calcium tolerance test indicated a significantly greater increase in serum calcium (delta serum calcium: 1.4 mg/dl vs 0.8 mg/dl) and a significantly greater suppression of urinary cyclic AMP excretion (delta U-cyclic AMP:-3.56 moles/gCre vs-1.17 moles/gCre) before parathyroidectomy than after. These results showed that hypercalciuria in this case was induced not only by the significant increase in the filtrated load of calcium but by the reduction in the resorption of calcium in the distal tubule caused by the significantly suppressed parathyroid hormone effect.
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PMID:[A case report: primary hyperparathyroidism--comparison before and after parathyroidectomy by oral calcium tolerance test]. 283 26

The characteristics of PTH secretion, which have been extensively studied in vitro with dispersed cells of normal and abnormal parathyroid glands, remain poorly studied in vivo. We performed ethylenediamine tetraacetate (EDTA) intravenous infusions in 12 normal subjects and 5 patients with hypercalcemia (serum ionized calcium between 2.72 and 2.89 mEq/l) and surgically proven primary hyperparathyroidism (PHPT) to establish the relationship between nephrogenous cyclic AMP (NcAMP) used as an index of PTH secretion and serum ionized calcium. We determined the maximal NcAMP taken as an index of maximal secretory rate for PTH, the set point and sensitivity of parathyroid cells for calcium. In normal subjects, mean values (+/- SD) were 4.04 +/- 0.47 nmol/dl glomerular filtrate (GF) for maximal NcAMP, 2.23 +/- 0.04 mEq/l for set point, and -250 +/- 58 for sensitivity when NcAMP was expressed in percent of maximal value and serum calcium in mEq/l. In patients with PHPT, the differences between maximal and basal values of NcAMP represented 50% or more of maximal NcAMP, indicating that PTH secretion was suppressible. Sensitivity values were within normal limits in all patients. Calculated set point values were abnormally elevated (between 2.64 and 2.83 mEq/l) in all patients. Maximal NcAMP values ranged from low to normal (2.77 nmol/dl GF) to abnormally high (6.64 nmol/dl GF), and a positive linear correlation was observed with parathyroid cell mass. Basal serum calcium concentrations were not correlated with either parathyroid cell mass or maximal NcAMP values, and were close to calculated set point values for each patient.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Maximal PTH secretory rate and set point for calcium in normal subjects and patients with primary hyperparathyroidism. In vivo studies. 285 Apr 60

In a 14-years period (1970-1984) eight-three patients were operated on for primary hyperparathyroidism (pHPT) at the University Hospital of Erlangen. Special attention was paid to associated diseases, symptoms, preoperative diagnostic parameters were serum calcium, parathyroid hormone in venous blood, cyclic AMP in 24 h-urine. In 15.7% only borderline increased serum calcium values were measured. Ulcer incidence in pHPT was 19% as compared with approx. 7% in the general population. There was no increased incidence of pancreatitis in pHPT. The possibility of an association of pHPT with the Multiple Endocrine Neoplasia (MEN) syndrome was emphasized and measures of early diagnosis proposed.
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PMID:[Primary hyperparathyroidism--experiences with concomitant diseases, symptoms, preoperative diagnosis and surgical procedure over a period of 14 years]. 288 2


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