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)

Hypercalcemic crisis or severe hypercalcemia represents a life-threatening emergency. The most common cause is hypercalcemia of malignancy, although granulomatous diseases, previously undetected primary hyperparathyroidism, medication-induced hypercalcemia, and a few rarer causes may result in this endocrine emergency as well. The clinical presentation and prognosis depend on the acuity of the development of hypercalcemia, the degree of hypercalcemia, and the underlying cause. Certainly, patients with malignancy who develop hypercalcemia superimposed on their already debilitated state are more likely to have a poor outcome than a previously relatively healthy patient with thiazide-induced hypercalcemia, for example. The clinical presentation of patients with hypercalcemic crisis varies depending once again on the underlying cause and degree and rapidity of the hypercalcemia. Most patients experience some constitutional symptoms, neurologic symptoms, gastrointestinal symptoms, and renal manifestations of hypercalcemia. Immediate and effective therapy directed toward the pathophysiology of hypercalcemia is essential. General measures must be implemented to reverse the dehydration, to promote urinary calcium excretion, to avoid prolonged immobilization, and to identify the underlying cause of hypercalcemia. Specific measures directed at inhibiting bone resorption, increasing renal sodium and calcium excretion, and occasionally at decreasing intestinal absorption of calcium (or more specifically blocking vitamin D metabolism) should also be implemented. Obviously the more reversible the underlying cause of hypercalcemia, the more aggressive one should be with the therapy. The literature was reviewed to compile comparative data that practitioners may use in choosing among the various pharmacologic therapies available for the treatment of acute hypercalcemia. Despite all the advances in the field, hypercalcemic crisis still carries a significant mortality risk, although with appropriate therapy with the aforementioned general and specific measures, the calcium level can effectively be lowered in most patients.
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PMID:Hypercalcemic crisis. 780 96

Careful examination as well as biochemical and hormonal investigations should be performed in men suffering from vertebral crush fractures, in order to detect a destructive skeletal process (multiple myeloma, bone metastatic lesions, lympho and myeloproliferative disorders), a mineralization defect (osteomalacia) or a secondary osteoporosis: primary hyperparathyroidism, hypogonadism, hyperthyroidism, renal hypercalciuria, alcoholism and tobacco smoking. The diagnosis of idiopathic osteoporosis should be made only after these causes have been excluded; the pathogenesis of the disease is unclear but risk factors have been identified: family history of osteoporosis, low dietary calcium intake, delayed puberty, ethanol use, tobacco smoking, inactive lifestyle and lean body build. Correction of risk factors, calcium supplementation, regular program of weight bearing physical activity, in some instances correction of testosterone deficiency may be of benefit to reduce bone loss. Severe osteopenia or osteoporosis may require sodium fluoride therapy.
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PMID:[Male osteoporosis]. 793 30

The use of sodium clodronate in the treatment of primary hyperparathyroidism is described. The drug successfully reduced the serum calcium but without improvement in the patients muscle and joint symptoms. It appears that mild degrees of hypercalcaemia have few clinical effects.
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PMID:Sodium clodronate in a patient with the Eisenmenger syndrome, hyperparathyroidism and multiple endocrine adenomatosis. 810 43

In order to evaluate the role of the hyperparathyroid state for blood pressure and volume homeostasis, eight patients with primary hyperparathyroidism were studied before and after corrective surgery. Neither noradrenaline induced blood pressure changes nor basal blood pressure were affected by the operation, and the values were the same as in an age- and sex-matched control group. Noradrenaline infusion induced an increase in PTH(1-84) values before (72-86 ng l-1, medians, p < 0.02), in contrast to a decrease after (28 to 19 ng l-1, p < 0.05) operation for primary hyperparathyroidism. Basal plasma atrial natriuretic peptide was lower before than after removal of adenomata (3.2 vs. 4.8 pmol l-1, medians, p < 0.02). Cyclic 3'-5'-guanosine monophosphate was not significantly changed (4.7 vs. 5.5 nmol l-1). Aldosterone was higher before than after surgery (139 vs. 71 pmol l-1, p < 0.02), whereas angiotensin II was unaltered (20 vs. 9 pmol l-1). Arginine vasopressin was higher before than after the operation (0.9 vs. 0.7 pmol l-1, p < 0.05), but urinary excretion of prostaglandin E2 was unchanged. In conclusion primary hyperparathyroidism was not associated with changes in noradrenaline reactivity or basal blood pressure despite derangements of hormones adjusting sodium and water homeostasis. It is suggested that the hormonal changes may be secondary to a relative volume depletion.
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PMID:Unchanged noradrenaline reactivity and blood pressure after corrective surgery in primary hyperparathyroidism. 821 Sep 70

The principal pathophysiologic alteration in severe hypercalcemia accompanying hyperparathyroidism and malignancy is enhanced osteoclastic bone resorption. Hypercalcemia impairs renal mechanisms that lead to sodium and calcium excretion; PTH and PTHrP acting on renal tubules enhance further calcium reabsorption. Although rehydration is often necessary as an initial therapy of hypercalcemia, the cornerstone of therapy is to inhibit osteoclastic bone resorption. The bisphosphonates, plicamycin, gallium, and calcitonin all inhibit osteoclastic bone resorption. Calcitonin is the most rapidly acting agent. Toxicities of calcitonin are minimal, yet its therapeutic efficacy is limited by lack of potency and tachyphylaxis. The second-generation bisphosphonates such as pamidronate represent a class of compounds that are extremely effective in inhibiting the metabolic function of the osteoclast. Given in a single infusion, a significant majority of patients will have normalization of corrected serum calcium lasting, on average, 1-2 weeks. Therapeutic benefit will be of greater duration because most patients remain only minimally symptomatic until corrected serum calcium rises above 11.5 mg/dL. Side effects of low-grade fever, hypophosphatemia, hypomagnesemia, and hypocalcemia may occur. Gallium nitrate is a potent inhibitor of bone resorption and may be of increased clinical value when more efficient administration protocols can be developed. Plicamycin, available for two decades, has cumulative toxicities and is less potent than the aminobisphosphonates. Renal insufficiency often accompanies severe hypercalcemia. The nephrotoxicity of gallium nitrate and plicamycin should preclude their use when there is moderate impairment of renal function, and amino bisphosphonates become the treatment of choice in these patients. Although several authors have advocated individualized approaches to the management of hypercalcemia, the potency and duration of action of the aminobisphosphonates make them a reasonable treatment choice for most patients with symptomatic hypercalcemia. Most importantly, the most effective therapy for hypercalcemia is to recognize and treat the underlying disease. Acute primary hyperparathyroidism requires surgery. The effective treatment of hypercalcemia of malignancy allows the introduction of tumor-specific therapy, limits morbidity, and shortens and deintensifies hospitalization. At times, the most appropriate and compassionate decision (particularly in patients with malignancy who have exhausted all therapeutic options and have relentless bone pain) is to withhold therapy for hypercalcemia. Future therapies directed at the osteoclast, such as more potent later-generation bisphosphonates; inhibitors of osteoclast attachments and inhibitors of peptides, which stimulate osteoclastic bone resorption, may permit safe, easily administered, outpatient therapies that will improve the quality of life for hypercalcemic patients.
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PMID:Pathophysiology and management of severe hypercalcemia. 832 91

The authors treated 18 patients with Paget's disease of bone (12 men and 6 women, age 65 +/- 5 years) with pamidronate (bisphosphonate of the second generation). Three patients from this group were treated previously without success with calcitonin or bisphosphonate of the first generation (etidronate) 50% of the patients suffered from the polyostotic form of the disease. In one patient a rare combination of primary hyperparathyroidism with Paget's bone disease was found and in another patient later an osteosarcoma developed in the affected bone. To all patients sodium pamidronate was administered (Aredia, Ciba-Geigy) 30 mg per day by i.v. infusion for 2 hours during three days. Four patients developed fever, two patients phlebitis at the site of injection. These side-effects are described by the manufacturer. Two patients developed transient regional alopecia, not described so far. Subjective pain relief of the affected skeleton occurred in one patient after one month of treatment, after three months in 78%. Laboratory manifestations of activity of the disease (serum activity of alkaline phosphatase, tartrate resistant acid phosphatase and hydroxyprolinuria) declined gradually from the 1st to the 6th month after onset of treatment. There was a less marked decline of the osteocalcin serum concentration. The concentration of calcium, phosphorus and vitamin D metabolites did not change markedly. Twelve months after treatment 14.7% of the patients were inactive according to laboratory tests, 73% however experienced another rise of parameters of osteoresorption and osteoformation. Pamidronate treatment in patients with Paget's disease of bone is effective and safe.
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PMID:[Paget's disease of bone and treatment with pamidronate]. 837 65

The regulation of PTH secretion by calcium is altered in patients with primary hyperparathyroidism. A similar disturbance may occur in secondary hyperparathyroidism, but direct in vivo comparisons of PTH secretion in normal subjects and those with secondary hyperparathyroidism have not been made. Thus, 13 patients with end-stage renal failure and secondary hyperparathyroidism and 20 healthy volunteers underwent dynamic tests of PTH secretion. Changes in ionized calcium were induced by 2-h iv infusions of calcium gluconate or sodium citrate on consecutive days, and the sigmoidal relationship between serum ionized calcium and PTH levels was examined. During sodium citrate infusions, serum ionized calcium levels decreased by 0.21 +/- 0.04 and 0.20 +/- 0.05 mmol/L, respectively (mean +/- SD), in normal volunteers and dialyzed patients (P = NS). Serum PTH levels rose from 27 +/- 7 to 107 +/- 33 pg/mL in controls and from 480 +/- 238 to 859 +/- 412 pg/mL in dialyzed subjects; thus, maximum PTH levels were 396% of preinfusion values in normal subjects, but only 79% greater than baseline values in dialyzed patients (P < 0.001). During the first 30 min of calcium infusions, the increase in serum ionized calcium did not differ between groups, but PTH levels fell more rapidly in normal volunteers; values were 24% of preinfusion levels in controls, but only 56% of the baseline in dialyzed patients (P < 0.01) after 30 min. Minimum PTH levels were attained after 50 min of calcium infusion in normal volunteers and after 70 min in dialyzed patients. The derived values for set-point were 1.21 +/- 0.04 and 1.24 +/- 0.06 mmol/L, respectively, in control and dialyzed subjects (P = NS). These results do not support the contention that the set-point for calcium-regulated PTH secretion is greater than normal in patients with secondary hyperparathyroidism due to end-stage renal disease.
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PMID:Direct in vivo comparison of calcium-regulated parathyroid hormone secretion in normal volunteers and patients with secondary hyperparathyroidism. 850 Nov 55

The elemental composition of chief cells of parathyroid glands from patients with adenomatous primary hyperparathyroidism (HPT) and uremic secondary HPT was studied by X-ray microanalysis. Glands histologically deemed normal were used as controls. The analyses were also carried out on tissue specimens incubated in hypo-, normo- and hypercalcemic media (0.5, 1.25, and 3.0 mM calcium concentration). Analysis of chief cells from normal glands did not reveal any significant differences in ionic composition after exposure to the different calcium concentrations. In chief cells from adenomatous and uremic hyperplastic glands, elemental changes were noted. In comparison with specimens incubated in 1.25 mM calcium medium, cells in 0.5 mM calcium medium had a lower content of potassium and phosphorus. After stimulation with increasing extracellular concentration, an increase in the K/Na ratio was observed, due to a marked decrease of sodium and an increase of potassium; the calcium concentration was almost unchanged. Our findings indicate that in HPT an increase in serum calcium concentration might exert a stimulatory effect on the Na/K pump (sodium pump) and on the calcium-activated potassium channels. Either of these mechanisms might contribute to a lowering of cytoplasmic calcium. Our observations suggest that changes in ionic content of the parathyroid cells may be of importance for the stimulus secretion process in the cells.
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PMID:X-ray microanalysis of elemental changes in human parathyroid glands in primary and secondary hyperparathyroidism. 879 Nov 6

Hypercalciuria is a very frequent disorder that is defined by a daily calcium excretion rate in excess of 0.1 mmol/kg. Whatever its mechanism, it always expresses an increased input of calcium in extracellular fluid, from intestine and (or) bone. In few instances, hypercalciuria is secondary to an underlying disease that needs to be identified (primary hyperparathyroidism, cancer, granulomatosis...). However, in most cases, it is a primary (idiopathic) disorder that reveals an abnormal handling of calcium by intestinal and renal tubular epithelia. It is then treated by a restricted dietary supply in sodium and animal proteins, and by the use of thiazide diuretics.
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PMID:[Hypercalciuria]. 978 Nov 74

To understand the mechanisms responsible for the persistent hypercalciuria and reduced glomerular filtration rate (GFR) previously found in 6 of 10 patients surgically cured of primary hyperparathyroidism (PHPx), the tubular handling of lithium, sodium, calcium, and phosphate as well as the renal hemodynamics were evaluated in these 10 PHPx patients, in 10 control subjects, and in 5 patients with renal hypercalciuria (RH), during fasting and after an oral calcium load. A positive correlation between the fractional excretions of calcium and sodium was found in all groups, but the PHPx patients excreted more calcium for the same amount of sodium than control subjects. The fractional proximal sodium reabsorption (FPRNa), distal delivery, and fractional phosphate reabsorption were similar in all groups; a significant positive correlation was found between the fractional calcium reabsorption and the FPRNa, indicating that proximal tubular function was preserved and that the urinary calcium losses in RH and in the hypercalciuric PHPx patients (h-PHPx) occurred in the distal nephron. However, only h-PHPx patients had reduced renal plasma flow, renal blood flow, and GFR, as well as a high renal vascular resistance, which was even more evident after the calcium challenge. These findings lead us to conclude that RH and h-PHPx patients are very different, as far as kidney dysfunction is concerned, and that a hypercalcemic nephropathy is the most probable cause of the alterations in distal calcium reabsorption and renal hemodynamics found in the h-PHPx patients.
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PMID:Changes in renal hemodynamics and tubular function of surgically cured primary hyperparathyroid patients are probably due to chronic hypercalcemic nephropathy. 979 75


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