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

The Leydig cell tumor Rice H-500 is a model of humoral hypercalcemia of malignancy. Hypercalcemia is considered to result mainly from increased bone resorption. However, a change in renal tubular reabsorption of calcium (Ca) as a contributing factor to the hypercalcemia has not yet been recognized. The purpose of this study was to examine whether the renal handling of Ca was altered in Leydig cell tumor-bearing rats. To avoid counterregulations by Ca-regulating hormones, the effect of the Leydig cell tumor on plasma Ca and phosphate (Pi), urinary Ca and Pi excretion, as well as Ca and Pi renal tubular reabsorptive capacity was investigated in thyroparathyroidectomized rats. Clearance experiments were conducted at a time of tumor development when the glomerular filtration rate was not compromised. Under these conditions, tubular reabsorption of Ca was stimulated, and the maximal tubular reabsorption of Pi was markedly reduced (2.69 +/- 0.27 vs. 4.57 +/- 0.21 mumol/min; P less than 0.001). These changes were accompanied by increased urinary cAMP excretion (77.1 +/- 6.3 vs. 34.7 +/- 2.8 pmol/ml glomerular filtrate; P less than 0.001). These results indicate that the Leydig cell tumor produces a factor with PTH-like activity on the renal tubular reabsorption of Ca and Pi. The increased tubular reabsorption of Ca may play an important role in the pathogenesis of Leydig cell tumor-induced hypercalcemia. This animal model appears to be particularly appropriate for studying the mechanisms of certain types of humoral hypercalcemia of malignancy, as some cancer patients display a change in the renal handling of Ca similar to that observed in primary hyperparathyroidism.
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PMID:Parathyroid hormone-like changes in renal calcium and phosphate reabsorption induced by Leydig cell tumor in thyroparathyroidectomized rats. 375 93

This study was designed to follow the evolution of serum 1,25(OH)2D after surgery for primary hyperparathyroidism. Ten patients were studied before and for up to 85 d after removal of a single parathyroid adenoma. Blood and 24 h urine were obtained at various time points, for the measurement of serum or urinary phosphate and calcium indices. Before surgery, serum calcium (2.91 +/- 0.06 mmol/l; mean +/- SEM), parathyroid hormone (354 +/- 47 pg/ml) and 1,25(OH)2D (61.2 +/- 7.8 pg/ml) were elevated while serum phosphate (1.01 +/- 0.07 mmol/l) tended to be low. Relative hypoparathyroidism was evident for up to 5 d after surgery with the lowest value for serum parathyroid hormone (41 +/- 16 pg/ml) on day 1, serum calcium (2.12 +/- 0.06 mmol/l) on day 3 and highest value for serum phosphate (1.41 +/- 0.13 mmol/l) on day 5. As expected, serum 1,25(OH)2D levels decreased to 35.9 +/- 4.2 pg/ml 24 h after surgery. Stabilization of serum and urinary parameters to normal values was seen between day 5 and day 27; the only exception was serum 1,25(OH)2D, which increased again at day 27 to 57.6 +/- 5.0 pg/ml, a value as high as that before surgery. It was still elevated at day 50 (58.3 +/- 4.3 pg/ml), but returned towards normal values in three out of four patients (44 +/- 3.9 pg/ml) by day 80. No variation in 25(OH)D or 24,25(OH)2D was seen throughout the study. 1,25(OH)2D values could be related to serum parathyroid hormone values before surgery (r = 0.659, P less than 0.05) but not after. The secondary increase in serum 1,25(OH)2D could not be related to variations in serum calcium, phosphate, parathyroid hormone or diet. Further studies will be required to explain this phenomenon.
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PMID:Late increase in serum 1,25-dihydroxyvitamin D one month after surgery for adenomatous hyperparathyroidism. 375 58

To evaluate the relationship of parathyroid adenoma weight to perioperative serum calcium levels, 51 selected patients with pathologically confirmed single adenomas and minimal biopsy at operation were reviewed. Three age- and sex-matched groups were established according to adenoma weight. Compared with Group 1 patients who had adenomas of less than 1 g, Group 3 patients with adenomas of more than 2 g demonstrated significantly higher preoperative serum parathyroid hormone and calcium levels, and significantly lower preoperative serum phosphate levels. Multiple regression analysis revealed a strong correlation between adenoma weight to preoperative parathyroid hormone and calcium levels (r = 0.63, p less than 0.001). These results suggest that larger adenomas may be associated with a more severe form of primary hyperparathyroidism. The incidence of transient postoperative hypocalcemia in the 51 patients who underwent adenoma excision was 37 percent. Permanent hypoparathyroidism did not develop in any of them. Compared with Group 1 patients, Group 3 patients demonstrated a higher incidence of postoperative transient hypocalcemia (69 percent versus 14 percent in Group 1, p less than 0.001) and significantly lower mean serum calcium levels on the third and fourth postoperative days. Increased adenoma weight may be a valuable aid in identifying those patients at risk for transient hypocalcemia after neck exploration.
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PMID:Adenoma weight: a predictor of transient hypocalcemia after parathyroidectomy. 378 84

This is a first report of primary hyperparathyroidism (HPT) masquerading as a destructive fibrous sphenoid sinus "Brown tumor" associated with progressive blindness and hypercalcemia. Diagnosis of a Brown tumor was delayed despite serial computerized tomography of the head and repeated transnasal and transethmoid sphenoid biopsies demonstrating diffuse fibrosis. Only detection and medical evaluation of hypercalcemia, demonstrating elevation of both serum calcium and C-terminal parathyroid hormone with an elevated chloride/phosphate ratio, prompted neck exploration, thus confirming a solitary left superior parathyroid adenoma. Postoperative normocalcemia occurred synchronously with the return of light perception and the arrest of sphenoid sinus and parasellar erosion. Although maxillary Brown tumors of secondary HPT have been reported, this is the first report of osteitis fibrosa of the sphenoid sinus. Differential diagnosis of an erosive sphenoid lesion with cranial nerve dysfunction, exclusive of inflammatory or vascular disease, should include sarcoidosis, primary and metastatic sphenoid carcinoma, fibrous dysplasia, giant cell reparative granuloma, midline lethal granuloma, chordoma, and chondrosarcoma. Furthermore, the bony destructive lesions with concomitant hypercalcemia of sarcoidosis and HPT are distinguishable by radiographic and laboratory analyses and by the Dent corticosteroid suppression test. Hypercalcemia of primary HPT is associated with elevated serum C-terminal parathormone, osteitis fibrosa, a negative Dent test, and a chloride/phosphate ratio greater than 33 in 94% of primary HPT patients. Hypercalcemia of sarcoidosis is associated with a normal or decreased C-terminal parathormone assay and a positive Dent test, as well as elevated serum immunoglobulins and erythrocyte sedimentation rate, and a positive angiotensin-converting enzyme assay.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sphenoid sinus brown tumor, hypercalcemia, and blindness: an unusual presentation of primary hyperparathyroidism. 379 83

The synthesis of the active form of vitamin D, 1,25-dihydroxyvitamin D (1,25-(OH)2D), is thought to be relatively insensitive to the serum concentration of its precursor, 25-hydroxyvitamin D (25-OH-D). We compared the effect of oral administration of 25-OH-D3 (50 micrograms per day for one month) on serum concentrations of calcium, phosphate, parathyroid hormone, 25-OH-D, and 1,25-(OH)2D in five healthy adults and in six patients with primary hyperparathyroidism. In normal adults the mean (+/- S.D.) serum level of 25-OH-D rose from 18 +/- 9 to 136 +/- 47 ng per milliliter; no significant changes were observed in the other serum levels. In contrast, comparable increases in the levels of circulating 25-OH-D in patients with primary hyperparathyroidism caused a consistent slight rise in serum calcium and phosphate levels, a partial suppression of parathyroid hormone, and a sharp increase in the level of 1,25-(OH)2D. During this period a significant positive correlation was found between serum concentrations of 25-OH-D and 1,25-(OH)2D (P less than 0.001). These results provide evidence that in patients with primary hyperparathyroidism, levels of circulating 1,25-(OH)2D may be more dependent on the prevailing serum concentrations of 25-OH-D than they are in normal adults.
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PMID:Substrate-product relation of 1-hydroxylase activity in primary hyperparathyroidism. 384 Feb 28

We measured calcium, phosphate, chloride, albumin, C-terminal parathyrin, and beta 2-microglobulin in serum from 102 hypercalcemic patients: 42 with primary hyperparathyroidism and 60 with neoplasia. The calcium concentrations and the discriminant function index of Johnson et al. (Clin Chem 28, 333-338, 1982) were higher in malignant hypercalcemia than in primary hyperparathyroidism. The diagnostic efficiency of the index and of parathyrin concentration was 82% and 78%, respectively. Using the ratio of parathyrin to beta 2-microglobulin increased the diagnostic efficiency to 98%; the ratio of the discriminant index to parathyrin concentration had a diagnostic efficiency of 100%. We conclude that C-terminal assay by itself is no better than the discriminant function index.
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PMID:Value of measuring C-terminal parathyrin in differential diagnosis of hypercalcemia. 390 87

Hypercalcaemia can be caused by many disorders, but is most commonly due to primary hyperparathyroidism in outpatients, and to malignant disease in hospital inpatients. When mild (less than 3 mmol/L) it does not cause symptoms, but can have long term effects such as renal calculi. It is important that the aetiology of the hypercalcaemia be established, as it can reflect serious disease. In most patients the correct diagnosis can be suspected from clinical history and examination, and confirmed by laboratory tests and x-rays. The most difficult diagnostic problem is the patient with negative clinical findings, mild hypercalcaemia and mild renal impairment, when the parathyroid hormone level is normal or slightly elevated. When hypercalcaemia is severe (greater than 3.5 mmol/L), it can cause vomiting, polyuria, dehydration and renal impairment, and is then an important therapeutic problem. Therapy includes treatment of the cause, such as radiotherapy for malignant disease or surgery for primary hyperparathyroidism. In addition, it is usually necessary to treat the hypercalcaemia itself, and the initial step is always rehydration. If the plasma calcium concentration remains high, drug treatment must be added, the most effective and reliable agent being intravenous mithramycin. Aminohydroxypropylidene diphosphonate (APD), though less studied, may be equally useful in this situation. Glucocorticoids are not always effective, and phosphate may cause renal damage, particularly when given intravenously. For long term treatment of malignant hypercalcaemia, oral glucocorticoids and phosphate are often effective, and can be given in combination. When primary hyperparathyroidism cannot be corrected surgically, the hypercalcaemia (and hypercalciuria) are probably best treated with a low calcium diet and cellulose phosphate, a regimen also effective for the hypercalcaemia of sarcoidosis.
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PMID:Hypercalcaemia. What does it signify? 394 Aug 49

In order to obtain a good separation line between patients with primary hyperparathyroidism (1 degree HPT) and those with non-parathyroidal hypercalcemia (NPHC), serum chloride (Cl) and phosphate (P) concentrations were analyzed. Ninety-nine per cent of the patients with 1 degree HPT had a Cl/P ratio greater than or equal to 33, but 29% of patients with NPHC were also included in this range. When the (Cl-90)/P ratio was used to separate into two groups, 98% of the patients with 1 degree HPT had a ratio greater than or equal to 5.0, and 94% of the patients with NPHC had a ratio less than 5.0. From these results, while high sensitivity was achieved both with the Cl/P and (Cl-90)/P ratios, the (Cl-90)/P ratio provided higher specificity. Therefore we conclude that the (Cl-90)/P ratio was excellent in distinguishing 1 degree HPT from other types of hypercalcemia.
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PMID:Clinical usefulness of the (chloride-90)/phosphate ratio for distinguishing primary hyperparathyroidism from hypercalcemia due to other causes. 404 94

We have investigated and treated 176 patients who were suffering from renal calculi. The stones contained calcium in 87% of patients, predominantly urate in 11%, and rarely contained magnesium ammonium phosphate or cystine. Of the patients with calcium stones, hypercalciuria was present in 75% and was identified in 57% by the measurement of the 24-hour urinary calcium excretion, and in a further 18% by a standardization calcium "fast-and-load" test. Nine patients were found to have primary hyperparathyroidism and were treated surgically. A further 21% were suspected to have normocalcaemic hyperparathyroidism, and metabolic studies are being developed to clarify this. The treatment of hypercalciuria included a low-calcium diet, and various combinations of a thiazide diuretic, phosphate supplements and sodium cellulose phosphate. Hypercalciuria was controlled in all compliant patients, and only two developed further stones. Hyperuricosuria was rarely the sole metabolic abnormality in patients with calcium stones, though this might reflect the referral pattern of the Unit. Uric acid stones were frequently, but not invariably, associated with hyperuricosuria and acid urine, and even large uric acid calculi dissolved with a combined therapy of high fluid intake, allopurinol and an alkalinizing agent. Surgical treatment was rarely required in these patients. A stone in the renal pelvis of one patient was removed percutaneously and did not require ultrasonic fragmentation. Modern methods of investigation and treatment have greatly improved the outlook for patients with recurrent renal calculi.
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PMID:Investigation and treatment of renal calculi. 404 15

A 26-year-old woman was admitted to the Institute of Endocrinology in Bucharest for evaluation of primary hyperparathyroidism (P-HPT). Anamnesis revealed a 10-year history of nephrolithiasis; peptic ulcer, chronic pancreatitis, cholelithiasis. Eight months previously, she had given birth to a child who had neonatal hypocalcaemic tetany. Investigations revealed the presence of moderate hypercalcaemia, hypercalciuria, hypo-phosphoremia; serum chloride level was above 100 mEq/1, and the chloride phosphate ratio was greater than 33. X-ray films of the abdomen revealed the presence of nephrolithiasis and right nephrocalcinosis. Selenium methyonine scanning, ultrasonography and computerized tomography were negative. On surgical exploration a 2-3 cm parathyroid adenoma was removed from between the trachea and the esophagus.
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PMID:Primary hyperparathyroidism. Report of a clinical case without bone lesions. 404 20


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