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)

We performed 6-h human PTH-(1-34) infusions in 8 control subjects, 10 subjects with primary hyperparathyroidism, and 7 men with idiopathic hypercalciuria. We measured serum calcium, serum 1,25-dihydroxyvitamin D, urinary calcium, and fractional phosphate excretion. The PTH-induced rise in serum 1,25-dihydroxyvitamin-D was significantly smaller in the hyperparathyroid patients than in either the controls or the hypercalciuric patients. The rise in serum calcium was similar in all 3 groups. The hyperparathyroid subjects had higher basal fractional phosphate excretion than the other two groups. PTH failed to increase fractional phosphate excretion in the hyperparathyroid individuals, whereas there was a statistically significant increase in the other two groups. PTH was without significant effect on urinary calcium excretion in any of the three groups. There were no discernible differences between the responses of the hypercalciuric patients and those of the normal subjects. These findings suggest that while responses to PTH are normal in hypercalciuria, some hyperparathyroid patients are resistant to exogenous PTH. This resistance is limited to specific arms of the PTH response pathway and may not involve PTH receptors.
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PMID:Parathyroid hormone sensitivity in primary hyperparathyroidism and idiopathic hypercalciuria: effects on postadenylate cyclase parameters. 215 86

An oral calcium load test (CLT) (1 gm Ca/50 kg) was administered to 11 control subjects and 35 patients with overt hyperparathyroidism to assess its efficacy in diagnosis of hyperparathyroidism. All participants were placed on a low-calcium diet 3 days before the CLT. Intact parathormone and ionized calcium (Cai) levels were measured 0, 1, 2, and 3 hours after CLT. Initial Cai and parathormone (mean +/- SE) were 1.22 +/- 0.01 mmol/L and 2.94 +/- 0.03 pmol/L in the control group compared with 1.43 +/- 0.02 mmol/L and 10.6 +/- 2.2 pmol/L in the group with hyperparathyroidism. Both groups had a similar percent increase in Cai values (control, 5.9% +/- 0.8%; hyperparathyroidism, 6.3% +/- 0.6% (p greater than 0.1). A decline in parathormone levels of 47.6% +/- 2.8% in patients with hyperparathyroidism was significantly less than the 75.3% +/- 5.3% decline observed in control subjects (p less than 0.025). Three hours after CLT, parathormone was suppressed in control subjects, whereas a rebound occurred in patients with hyperparathyroidism. Postoperative CLT demonstrated a higher mean percent Cai increase and percent parathormone decline (Cai, 8.9% +/- 1.1%; parathormone, 67.9% +/- 1.8%) compared with preoperative values (Cai, 6.0% +/- 1.0%; PTH, 49.6% +/- 4.3%) (p less than 0.025), and 3 hours after calcium intake, parathormone remained suppressed, similar to control subjects. After surgery, three patients had elevated parathormone and low normal Cai levels and parathormone response to a CLT confirmed the diagnosis of secondary hyperparathyroidism. In conclusion, a CLT (1) can confirm the diagnosis of hyperparathyroidism and successful parathyroidectomy, (2) distinguished postoperative secondary from persistent primary hyperparathyroidism, (3) demonstrated nonautonomy of abnormal parathyroid glands with a parathormone response to a calcium load characterized by an earlier nadir, decreased suppressibility, and more rapid recovery, and (4) produced dynamic changes that did not distinguish patients with hyperparathyroidism from control subjects or hyperplasia from adenoma.
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PMID:Oral calcium load test: diagnostic and physiologic implications in hyperparathyroidism. 217 92

We report a postmenopausal woman with primary hyperparathyroidism (PHPT) and severe hypercalcemia while her total calcium intake was more than 2 g daily. Despite a markedly elevated intact PTH level, her serum 1,25-dihydroxyvitamin D [1,25-(OH)2D] level was low (17 pmol/L; 7 pg/mL). With reduced calcium intake, her serum calcium normalized, and 1,25-(OH)2D increased to 122 pmol/L (51 pg/mL). At the same time, intact PTH decreased to 32% of the initial value. PHPT may be associated with low circulating 1,25-(OH)2D levels. Furthermore, low 1,25-(OH)2D levels in PHPT may be due to a direct effect of severe hypercalcemia and be reversible with correction of hypercalcemia.
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PMID:Primary hyperparathyroidism and severe hypercalcemia with low circulating 1,25-dihydroxyvitamin D. 222 88

The mechanism whereby PTH, a potent stimulator of bone resorption, may under certain circumstances exert anabolic effects on bone is not known, but it is possible that it involves reduction of the size of osteoclast resorption lacunae. We have therefore made a detailed in vitro study of the effects of PTH and PTH-related peptide (PTHrP) on resorption by neonatal rat osteoclasts paying particular attention to the plan area of resorption pits. In order to distinguish between increased resorption at a particular site and increased numbers of sites, we have used an eyepiece graticule to define a focus of resorption, namely an area occupying 1/116th of the bone slice, which may contain either one or several pits. In addition we have studied the relationship between the number of pits in a resorption focus and the total area of bone resorbed at the focus. We found that PTH and PTHrP, at doses between 2 x 10(-10) M and 2 x 10(-8) M, while exerting significant stimulatory effects on bone resorption, caused a reduction in the median plan area of pits. An increase in the number of resorption foci was the primary stimulatory effect of PTH and PTHrP, occurring within 6 h in the case of PTH. However, the plan area of bone resorbed at a focus showed no significant increase, despite an increase in the number of pits per focus, because as more pits were formed at a focus, the pits were smaller, thus partially dissipating the stimulatory effect of PTH on resorption. These results are consistent with the activation of new remodeling sites by PTH in vivo. Furthermore, the formation of smaller pits under the resorptive influence of PTH may, together with the maintenance of coupling between formation and resorption, play a role in the preservation of cancellous bone recorded in cases of primary hyperparathyroidism and the anabolic effect of exogenous PTH.
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PMID:The effects of parathyroid hormone (PTH) and PTH-related peptide on osteoclast resorption of bone slices in vitro: an analysis of pit size and the resorption focus. 224 18

Forty-three women (mean age 67 years, range 34-84 years) with primary hyperparathyroidism were investigated in an effort to examine the regulation of the 1-alpha-hydroxylase. This enzyme catalyzes the 1-hydroxylation of 25-hydroxy-vitamin D [25(OH)vit D] to 1,25-dihydroxy-vitamin D [1,25(OH)2vit D]. Serum 25(OH)vit D, 1,25(OH)2vit D, PTH, ionized calcium, phosphate and the 24-hour clearance of creatinine were measured. Different linear regression models were calculated with 1,25(OH)2vit D as the dependent variable. 25(OH)vit D was found to be definitely important for the regulation. The role of PTH for the 1,25(OH)2vit D production was discussed. Both renal function and phosphate concentration were found to influence the 1-alpha-hydroxylation.
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PMID:Respective roles of 25 hydroxy-vitamin D, PTH, phosphate and renal function for the 1-alpha-hydroxylase activity in primary hyperparathyroidism. 227 5

To evaluate the effects of primary hyperparathyroidism (PHPT) on bone mass and structure, we have studied the iliac crest biopsies of 27 patients, 10 males (28-68 yr old) and 17 females (26-72 yr old) with mild PHPT after in vivo tetracycline labeling. All patients had mild hypercalcemia in the absence of any other cause and elevated levels of PTH without radiological evidence of bone disease. Static parameters of bone turnover (osteoid surface, osteoid volume, and eroded surface) were elevated in both men and women compared to normal values; the midmolecule RIA for PTH (PTHMM) was positively correlated with osteoid surface (r = 0.44; P less than 0.025) and eroded surface (r = 0.58; P less than 0.005). Dynamic parameters of bone turnover (mineralizing surface, expressed as double plus half single labeled surface, and bone formation rate at tissue level) were elevated compared to normal values; PTHMM was positively correlated with double plus half single labeled surfaces (r = 0.33; P less than 0.05) and with bone formation rate at the tissue level (r = 0.37; P less than 0.05). The mineral apposition rate was within the limits of normal values and positively correlated with PTHMM (r = 0.34; P less than 0.05). Histomorphometric parameters of bone structure [cancellous bone volume (BV/TV), trabecular thickness (Tb. Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), cortical thickness (Ct.Th), and total bone density (TBD)] were compared to those in 20 autopsy control subjects, 12 men (33-60 yr old) and 8 women (27-75 yr old). BV/TV and Tb.N were significantly higher in PHPT patients than controls (P less than 0.02 and P less than 0.001, respectively). Tb.Sp was significantly lower in PHPT patients than controls (P less than 0.001), whereas Tb.Th was not significantly different between PHPT patients and controls. Ct.Th was significantly lower in PHPT patients than in controls (P less than 0.001), whereas TBD was not significantly different between the two groups. BV/TV was negatively correlated with age in both controls and PHPT patients. Tb.N showed a negative correlation and Tb.Sp a positive correlation with age in controls (r = -0.47; P less than 0.05 and r = 0.52; P less than 0.02, respectively), but they were not significantly dependent on age in PHPT patients. Tb.Th, while showing no significant age-related change in controls, was negatively correlated with age in PHPT patients (r = -0.42; P less than 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The histomorphometry of bone in primary hyperparathyroidism: preservation of cancellous bone structure. 231 48

Exquisite sensitivity of normal parathyroid glands to small changes in ambient calcium concentrations and impaired sensitivity in primary hyperparathyroidism have been shown in vitro. Using an assay for PTH that detects rapid changes in PTH secretion (N-terminal-specific RIA; normal range, less than 3-33 pg/mL), we determined PTH suppressibility in response to a standardized dose of oral calcium in normal subjects and patients with primary hyperparathyroidism. Nine normal subjects were given oral calcium (25 mg/kg), and blood was analyzed half-hourly for 3 h for calcium and N-terminal PTH (N-PTH). Serum calcium rose by 0.34 +/- 0.06 mg/dL (0.085 +/- 0.015 mmol/L), and N-PTH levels declined rapidly from 15.3 +/- 1.4 to 4.2 +/- 1.1 pg/mL (-73 +/- 6%; P less than 0.01). In six subjects N-PTH concentrations became undetectable. Nine patients with primary hyperparathyroidism were tested in the same manner. Serum calcium rose by 0.53 +/- 0.1 mg/dL (0.13 +/- 0.025 mmol/L), and N-PTH levels declined less, from 66 +/- 14 to 52 +/- 12 pg/mL (-21 +/- 4%; P less than 0.05). In none of the patients was the PTH reduced to less than 20 pg/mL. These results illustrate in vivo that the PTH response to oral calcium in primary hyperparathyroidism is markedly different from that in normal subjects.
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PMID:Suppression of parathyroid hormone secretion with oral calcium in normal subjects and patients with primary hyperparathyroidism. 231 50

Rapid measurement of serum intact parathyroid hormone concentration was achieved by modification of an immunoradiometric assay for the hormone. Incubation of serum samples for 15 min at 37 degrees C under shaking gave optimal results in terms of assay variance and reproducibility: intra-assay CVs were less than 10% over the hormone concentrations of 11-1,600 pg/ml; intra- and inter-assay CVs for two control sera at different hormone levels were less than 12%. The minimal detectable hormone concentration was found at 27.8 pg/ml. The serum hormone levels of 43 subjects (31 health subjects, 9 patients with primary hyperparathyroidism, and 3 patients with secondary hyperparathyroidism) determined by either rapid or regular assay well correlated with each other (r2 = 0.979, p less than 0.001). In two patients with parathyroid adenoma serum intact PTH levels fell rapidly to 12.1% of the preoperative values 20 min after ligation of the vascular pedicle to the hyperfunctioning glands. We conclude that the modified assay protocol allows rapid, accurate, and simple estimation of intact PTH concentrations, and can be used as an intraoperative measure to aid both diagnosis and surgical cure of hyperparathyroidism.
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PMID:[Rapid measurement of human parathyroid hormone-(1-84) by immunoradiometric assay for use in intraoperative determination of hyperfunctioning parathyroid glands]. 234 80

Patterns of intact (1-84) parathyroid hormone (intact PTH) elimination and subsequent recovery of parathyroid function were studied in 12 patients undergoing parathyroidectomy. Nine patients had primary hyperparathyroidism (HPT), with single gland disease in 6 and multiple gland disease in 3. Two patients had subtotal parathyroidectomy for HPT secondary to chronic renal failure and 1 underwent excision of a hyperfunctioning parathyroid autograft. Using a sensitive 2-site immunochemiluminometric assay, serum intact PTH levels were measured preoperatively, intraoperatively, and postoperatively. A dual phase pattern of hormone clearance was found in 10 of the 12 patients, including the patient undergoing autograft excision. A monoexponential clearance pattern was seen in the remaining 2 patients, both of whom had subtotal parathyroidectomies for multiple gland disease. In the patients with primary HPT due to single gland disease, the early phase of intact PTH clearance had a half-life (T1/2) of 3.3 (+/- standard deviation 0.9) minutes and a late T1/2 of 96.4 (+/- standard deviation 92.7) minutes. Calculation of decay curves and half-lives for the patients undergoing subtotal parathyroidectomy was more difficult because of the inherent uncertainty in determining time zero. Nevertheless, in all but 2 patients, the clearance pattern was biexponential and the T1/2 measurements were very similar to those encountered in patients with single-gland disease. In the 2 patients with monoexponential clearance, the T1/2 figures were 86.7 minutes and 26.7 minutes, respectively. In the patients undergoing parathyroidectomy for primary HPT, levels of intact PTH were lowest at 1-3 hours after surgery, recovering to normal in the majority of patients by 18-40 hours.
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PMID:Study of intact (1-84) parathyroid hormone secretion in patients undergoing parathyroidectomy. 236 38

Until recently, nonfunctioning parathyroid cysts were usually identified at operation for a presumed thyroid mass. Thyroid needle biopsy now allows their preoperative diagnosis and potential definitive treatment. This study reviews four patients with nonfunctioning parathyroid cysts treated during a two-year period. Three women and one man range in age from 28 to 70 years. Each presented with an asymptomatic thyroid mass ranging from 3 to 5 cm in length. None had symptoms of primary hyperparathyroidism. Serum calciums were from 9.2 to 10.7 mg/dl and serum phosphoruses were 3.2 to 4.4 mg/dl. Needle aspiration revealed 5 to 85 cc of water-clear fluid. C-terminal parathyroid hormone in three patients was 12,600, 6,500 and 61,200 pg/ml and N-terminal PTH was 1,700 pg/ml in one. All four had normal serum calcium and phosphorus on follow-up ranging from six months to two years. Two patients had resolution of their cysts with a single aspiration. One patient had recurrence but has no evidence of recurrence six months after injection with tetracycline. Another patient had a recurrence but remains well one year following reaspiration. Nonfunctioning parathyroid cysts present as a thyroid mass. Needle aspiration of water-clear fluid high in parathormone is diagnostic and, in most patients, is the therapeutic modality of choice.
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PMID:Needle aspiration of nonfunctioning parathyroid cysts. 236 85


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