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

Twelve parathyroid chief cell adenomas from patients with primary hyperparathyroidism were incubated in a tissue culture system in the presence of different calcium concentrations and for various time periods. The endocrine response of the tissue was examined electron microscopically and radioimmunologically. After incubation in a medium of low calcium concentration the parathyroid adenomas showed ultrastructural signs of stimulation with proliferation of the hormone-synthesizing organelles. The development of the ultrastructural response could first be observed after four hours and increased up to several days. Radioimmunologically, an increase of the hormone secretion could be demonstrated. Converse results were obtained after incubation of the tumor tissue under suppressive culture conditions. To check for de-novo synthesis of the hormone released the tissue was incubated in a 75Se-methionine-containing medium. This resulted in radioactivity of the secreted parathyroid hormone, indicating de novo synthesis in our culture system. The biological potency of the released hormone was demonstrated by comparison of the PTH out of the medium with the international human MRC standard using two different radioassays.
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PMID:Correlation of electron microscopic and secretory response of human parathyroid adenomas with different calcium concentrations in organ culture. 15 Jan 11

Daily urinary cyclic AMP (AMPcU) has been compared to pth plasma level and to bone resorption parameters in 44 cases of metabolic bone disease. In 14 cases of primary hyperparathyroidism, AMPcU was always increased likewise in 4 cases of osteomalacia with secondary hyperparathyroidism. On the whole series of cases a significant correlation has been found (1) between PTH plasma level and AMPcU and (2) between bone resporption surfaces and AMPcU. Conversely, no correlation between PTH and periosteocytic lacunae size, nor between AMPcU and periosteocytic lacunae has been found.
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PMID:[Relation between urinary cyclic AMP, PTH and histomorphometric resorption parameter. A study of 44 human iliac crest bone biopsies]. 18 20

Plasma hCT levels were less than 50 pg/ml in 50 normal subjects. In 16 patients with medullary carcinoma of the thyroid (MCT), plasma hCT levels were distinctively elevated and they fell significantly after total thyroidectomy, but in 11 of them plasma levels were still high, indicating the presence of metastases. In 74 patients with the other types of malignancy, plasma hCT levels were found to be high in 9 cases (3 oat cell carcinoma of the lung, 4 malignant carcinoids, one malignant pheochromocytoma and one acute myelocytic leukemia). Except for the leukemic case, all these tumors were derived from neural crest. In 12 patients with primary hyperparathyroidism, plasma hCT levels were less than 20 pg/ml. In 13 hypoparathyroid patients, two with pseudohypoparathyroidism and one with pseudoidiopathic hypoparathyroidism, plasma hCT levels were slightly elevated. Some patients with uremia had elevated plasma hCT levels, but there was no relation between plasma levels of hCT and those of PTH, urea nitrogen or creatinine. In response to Ca (4.5 mg/kg/10 min) or tetragastrin (4 mug/kg/5 min) infusion, a marked increase in plasma hCT was observed in all patients with MCT, but not in normal subjects. In 5 hypoparathyroid patients, a significant increase to both stimuli was also observed in all cases. Two patients with pseudopseudohypoparathyroidism responded to the Ca load. These results indicate that the determination of plasma hCT levels especially after a short Ca or tetragastrin infusion is important to study various pathological conditions.
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PMID:Plasma human calcitonin (hCT) levels in normal and pathologic conditions, and their responses to short calcium or tetragastrin infusion. 19 Dec 50

States of hypersecretion of PTH may occur primarily, or in response to other physiologic abnormalities. Primary hyperparathyroidism must be considered in the differential diagnosis of hypercalcemia, nephrolithiasis, metabolic bone disease, and pancreatitis and peptic-ulcer disease. The clinical manifestations of this disease have become more subtle with improved detection. The serum calcium level is almost always elevated, and when it it accompanied by relatively high serum PTH levels or increased urinary cAMP excretion, the diagnosis is usually secure. Findings of hypophosphatemia, decreased renal tubular reabsorption of phosphorus, hypercalciuria, and characteristic roentgenographic changes support the diagnosis of hyperparathyroidism, but are not prerequisites for that diagnosis. Most cases will come to operation, and experienced intraoperative assessment is necessary for the correct distinction between multiglandular disease and that involving only a single gland. We expect that a clearer understanding of the histopathologic features of these diseases, and improvement in the methods for measurement of PTH will be the main areas of advancement in the diagnosis of hyperparathyroidism in the next few years.
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PMID:Diagnosis of hyperparathyroidism. 19 30

It is uncertain whether normocalcemic, normocalciuric patients with calcium nephrolithiasis have a disorder of calcium metabolism. We studied the effect of a parathyroid extract (PTE) INFUSION (1.4 U/kg body weight) on the urinary cyclic AMP excretion in 16 such patients. For comparison, we investigated groups of normal individuals and patients with primary hyperparathyroidism, renal insufficiency and different gastrointestinal diseases. The increase of cyclic AMP above basal excretion in patients with nephrolithiasis was only 1.2 +/- 0.3 mumol/h (mean +/- SEM), versus 2.5 +/- 0.5 mumol/h in normal subjects (p less than 0.05) although the basal excretion was similar. Patients with renal insufficiency had low basal excretion of cyclic AMP and little stimulation of excretion by PTH (increase, 0.3 +/- 0.06 mumol). Patients with primary hyperparathyroidism had high baseline cyclic AMP excretion but sub-normal stimulation by PTE (increase, 0.46 +/- 0.13); in contrast, patients with different gastrointestinal disease had high baseline excretion and supranormal stimulation of cyclic AMP excretion (increase, 5.2 +/- 0.6). We speculate that an impaired response to PTH might be involved in the slightly increased urinary calcium excretion in normocalcemic stone formers suggested by others.
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PMID:Effect of parathyroid extract on renal cyclic AMP excretion in patients with normocalciuric nephrolithiasis. 20 1

Hypercalcemia after renal transplantation (post-T hypercalcemia) has been detected in 29 (16.7%) of 174 long-term survivors. The mean time of onset of hypercalcemia was 69 days after renal transplantation (range 3-210). In 18 patients the hypercalcemia was mild and resolved spontaneously (transient) from 2-65 months (mean 19) after onset. In 4 patients serum calcium normalized concurrently with rejection episodes. In 7 patients the hypercalcemia was more pronounced (permanent), being terminated by subtotal parathyroidectomy in 5 and persisting in 2 recipients. The hypercalcemia was asymptomatic except in one patient, who developed calculi in the graft and a fall in graft function, all of which disappeared after parathyroidectomy. At operation the parathyroid glands showed hyperplasia, except in one case with an adenoma in one of the hyperplastic glands. Serum phosphorus was markedly decreased, to the same extent in transiently and permanently hypercalcemic recipients. Serum parathyroid hormone (S-PTH) was increased in all of 5 patients with permanent and in 3 of 8 with transient post-T hypercalcemia. In normocalcemic and in transiently hypercalcemic recipients the mean S-PTH was identical, but significantly lower than in the permanently hypercalcemic recipients. S-PTH was suppressed to the same extent during an i.v. calcium infusion in patients with post-T hypercalcemia and with primary hyperparathyroidism.
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PMID:Hypercalcemia and parathyroid function after renal transplantation. 31 22

Rapid differential diagnosis of hypercalcaemia due to primary hyperparathyroidism or malignancy with or without bone metastases may be life saving. A parathormone infusion test (6 USP units/kg body wt X 20 min) enables a differential diagnosis within three hours by means of measurement of renal calcium excretion. In normal persons calcium excretion decreased from 147 +/- 90 to 79 +/- 54 mumol/h (x +/- s, n = 10). In primary hyperparathyroidism with hypercalcaemia the high calcium excretion remained unchanged: 716 +/- 162 mumol/h before and 804 +/- 130 mumul/h 120 minutes after the PTH infusion (n = 12). In patients with hypercalcaemia caused by bronchial carcinoma with (n = 5) and without (n = 1) bone metastases calcium excretion decreased from 552 +/- 182 to 163 +/- 114 mumol/h. As a consequence of these data this test is advisable when the indication for operation in cases with hypercalcaemia has to be reached within a few hours.
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PMID:[Differential diagnosis of hypercalcaemia by measurement of renal calcium excretion during parathormone administration (author's transl)]. 49 90

1. The distribution of intact parathyroid hormone-(1-84) [PTH-(1-84)] and of its COOH-terminal fragments was determined in human serum by column chromatography. In addition to PTH-(1-84) (peak I), COOH-terminal fragments having molecular weights of approximately 4000-7000 (peak II) and immunoreactive components co-eluting with human PTH-(1-12) (peak III) were observed. 2. Mean concentrations of intact PTH-(-84) and of its COOH-terminal fragments were significantly raised in chronic renal failure as compared with those of normal subjects. Mean amounts of peak II were higher in patients with chronic renal insufficiency than in nutritional vitamin D deficiency, in pseudohypoparathyroidism and in primary hyperparathyroidism, despite comparable amounts of PTH-(1-84). 3. In chronic renal failure as well as in a group of patients with vitamin D deficiency, pseudohypoparathyroidism and primary hyperparathyroidism and in controls, significant linear relations were found between the serum concentrations of calcium and log (peak II/peak I). Our findings suggest that the conversion of intact PTH-(1-84) into COOH-terminal fragments by the parathyroid glands (resulting in a raised secretion of fragments) and/or in peripheral organs may be directly related to the serum concentration of calcium. However, the degradation of the fragments may also be suppressed in a calcium-dependent manner.
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PMID:Distribution of circulating immunoreactive components of parathyroid hormone in normal subjects and in patients with primary and secondary hyperparathyroidism: the role of the kidney and of the serum calcium concentration. 51 52

Aim of the present study was to establish the limits and difficulties prevailing in RIA of PTH due to different specificity of antisera. Studies were carried out on normal volunteers and 36 patients with primary hyperparathyroidism (HPT) employing two different assay techniques a) 211/32 antiserum from Wellcome Lab. and b) Immuno Nuclear Corporation Kit. Plasma iPTH values were higher in most primary HPT patients than in normal subjects with both techniques. It is possible nevertheless to differentiate the primary HPT patients with normal plasma iPTH values from normal subjects by correlating plasma iPTH values with corresponding serum calcium values.
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PMID:[Values and limitations of the radioimmunological determination of plasma parathyroid hormone in the study of the functional activity of the parathyroid glands]. 55 Aug 92

We studied six different antisera to bovine or porcine parathyrin (parathyroid hormone, PTH), produced in rabbit, guinea pigs, sheep or goat, two of which are commercially available. The antisera were characterized with regard to species specificity, affinity and their ability to identify patients with primary hyperparathyroidism. In this heterologous radioimmunoassay system in which [125I]parathyrin is used as a tracer, some cross-reactivity of the antisera to the hormone or hormone fragments present in human serum was demonstrated. However, there is some overlap of serum immunoreactive parathyrin in patients with or without primary hyperparathyroidism. The results of this and other studies illustrate the necessity for a homologous radioimmunoassay for human parathyrin.
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PMID:Radioimmunoassay for parathyrin. Characterization of six different antigens and antisera. 56 81


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