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)

This is an investigation into the finding that patients with primary hyperparathyroidism caused by Water Clear Cell Hyperplasia (WCCH) frequently belong to blood group O. Two control groups were defined from the same time period as 32 cases of WCCH treated at our clinic: one was a consecutive patient series with other forms of primary hyperparathyroidism (n = 864) and the other was the population in a geographically defined area in Sweden (n = 59,862). The blood group distribution of the patients with WCCH differed from the distribution of the patients with other forms of primary hyperparathyroidism with high significance (P = 0.00040). The blood group distribution did not differ between the two control groups. Strong associations between disease and HL-A type have previously been described, while associations found between disease and ABO blood groups were weaker. The association between WCCH and blood group O described here is by far the strongest association with the ABO system demonstrated to date. It is possible that the presence of an O-allele is a prerequisite for the development of WCCH.
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PMID:Parathyroid water clear cell hyperplasia, an O-allele associated condition. 804 68

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

Prolonged decrease of elevated serum calcium levels after treatment with diphosphonates in patients with primary hyperparathyroidism (pHPT) is very rare. A patient with water clear cell hyperplasia and five enlarged glands is presented who received diphosphonates (day 1 through day 8 dichloromethylene diphosphonate orally and a single dose of 60 mg pamidronate on day 8 intravenously) leading to a significant fall in serum calcium levels. Surprisingly, there was no reactive increase in intact parathyroid hormone (PTH) in the following 18 days. Patients with missing PTH regulation to hypocalcemia after diphosphonates who need a period of stabilization prior to parathyroid surgery might benefit most from this therapy.
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PMID:Decrease of serum calcium concentration and lost influence of calcium on parathyroid hormone release in a patient with primary hyperparathyroidism after treatment with diphosphonates. 828 15

Parathyroid glands (n = 271) removed from 130 patients were examined by light and electron microscopy. A standardized method of tissue processing was employed and morphometry was performed. The aim of the paper is to provide a description of the human parathyroid chief cell ultrastructure in health and disease, with quantitative evaluation of structures involved in secretion of parathyroid hormone in a large case series, and to discuss their role in current diagnostic histopathology. The patients were euparathyroid (n = 10), or affected by primary (n = 97), secondary (n = 8), or tertiary (n = 15) hyperparathyroidism. In normal glands, solid parenchyma was composed of chief cells, large clear cells, transitional-oxyphil cells, and oxyphil cells. Chief cell hyperplasia, pseudo-adenomatous hyperplasia, adenoma, water-clear cell hyperplasia, and carcinoma were the most usual forms of parathyroid disease responsible for primary hyperparathyroidism. In chief cell hyperplasia, all the parathyroid glands were enlarged and the chief cells were in an active state of hormone secretion, with a large Golgi complex, abundant rough endoplasmic reticulum (RER), small lipid droplets, and tortuous plasma membrane. In pseudo-adenomatous hyperplasia, one gland was enlarged and the others displayed a normal size; however, electron microscopic examination and morphometric analysis showed that all the glands had active cells. Adenomas displayed a pattern similar to those of pseudo-adenomatous hyperplasia, with one gland enlarged and the others of normal size. However, ultrastructural examination and morphometry showed that the normal-size glands were hypo-active. Water-clear cell hyperplasia showed cells filled with cytoplasmic vacuoles. In these cells, structures with intermediate features between secretory granules and vacuoles were visible. Nucleo-cytoplasmic atypias were frequently visible in parathyroid carcinoma cells. In secondary and tertiary hyperplasia, active chief cells were regularly mixed with oxyphil or transitional-oxyphil cells. The tertiary hyperplasia was characterized by RER-associated structures that were not found in the normal or other pathological conditions. These results demonstrate that electron microscopy and morphometry represent useful tools in parathyroid histopathology.
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PMID:Ultrastructure of human parathyroid cells in health and disease. 858 May 10

The bisphosphonates have been investigated over the past two decades for the treatment of various diseases of bone and calcium metabolism that are characterized by increased bone resorption, including osteoporosis, Paget's disease, primary hyperparathyroidism, hypercalcemia of malignancy and metastatic bone disease. The bisphosphonate alendronate was recently approved by the U.S. Food and Drug Administration as a therapy for postmenopausal osteoporosis. This agent is currently the bisphosphonate of choice for clinical use. In postmenopausal osteoporosis, alendronate has been shown to increase bone mineral density and to decrease the rate of new fractures. Adverse effects are not usually a problem when 10 mg per day of alendronate is given with at least 6 oz of water 30 minutes before ingestion of the first food or beverage of the day.
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PMID:Alendronate: a bisphosphonate for treatment of osteoporosis. 890 Mar 45

Specialized cells (i.e., parathyroid chief cells) that sense changes in the extracellular calcium concentration are a key element in mineral ion homeostasis. The Ca2+o-sensing receptor (CaR) originally cloned from bovine parathyroid is also present in multiple nephron segments involved in Ca2+o homeostasis as well as in other sites that are not, such as brain, lung, large and small intestine. The physiological relevance of the CaR has been established by identifying hyper- and hypocalcemic disorders resulting from CaR mutations: familial hypocalciuric hypercalcemia (FHH) and neonatal severe hyperparathyroidism result from inactivating CaR mutations, while an autosomal dominant form ofhypocalcemia is caused by activating mutations. In addition to sensing Ca2+o and Mg2+o abnormally (the latter suggesting the CaR acts as an Mg2+o-sensing receptor), persons with FHH have alterations in their handling of water, supporting a role for the CaR in integrating mineral ion and water metabolism. Drugs that activate the CaR ('calcimimetics') are currently undergoing clinical trials and will permit pharmacological manipulation of the receptor when it functions abnormally (e.g., in primary hyperparathyroidism).
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PMID:Mutations in the calcium-sensing receptor and their clinical implications. 936 89

Recognizing the role of the extracellular calcium-sensing receptor (CaR) in mineral metabolism greatly improves our understanding of calcium homeostasis. The biology of the low affinity, G-protein-coupled CaR and the effects of its activation in various tissues are reviewed. Physiological roles include regulation of parathyroid hormone (PTH) secretion by small changes in ionized calcium (Ca2+) and control of urinary calcium excretion with small changes in blood Ca2+. The CaR also affects the renal handling of sodium, magnesium and water. Mutations affecting the CaR that make it either less or more sensitive to Ca2+ cause various clinical disorders; heterozygotes of mutations causing the CaR to be less sensitive to extracellular Ca2+ cause familial hypocalciuric hypercalcemia, while the homozygous form results in severe infantile hyperparathyroidism. Mutations causing increased sensitivity of the CaR to extracellular Ca2+ produce hereditary forms of hypoparathyroidism. Disorders, such as primary and secondary hyperparathyroidism, may exhibit acquired abnormalities of the CaR. Calcimimetic drugs, which amplify the sensitivity of the CaR to Ca2+, can suppress PTH levels, leading to a fall in blood Ca2+. Experiences with this agent in patients with secondary and primary hyperparathyroidism and parathyroid carcinoma are summarized. In animals and humans with hyperparathyroidism, this agent produces a dose-dependent fall in PTH and blood Ca2+, with larger doses causing more sustained effects. The treatment has been short-term except for one patient followed for more than 600 days for parathyroid carcinoma; nonetheless the drug did not cause major side-effects and appears to be safe. Further long-term controlled studies are needed with calcimimetic agents of this type.
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PMID:Calcium-sensing receptor and calcimimetic agents. 1063 65

Water-clear cell hyperplasia is a rare but well-documented cause of primary hyperparathyroidism. Parathyroid adenomas of the water-clear cell type are exceptionally rare, and only 2 cases have been reported. We describe a patient with synchronous water-clear cell double parathyroid adenomas, an entity that has not previously been reported. In our case, the enlarged superior parathyroid glands were completely replaced by water-clear cells, with only a minute rim of extracapsular, histologically unremarkable parathyroid tissue. The inferior parathyroid glands were grossly unremarkable, and incisional biopsy specimens were histologically normal (no foci of water-clear cells were identified). The findings in this case are most consistent with the diagnosis of double adenomas of the water-clear cell type. We acknowledge that despite molecular proof of monoclonality of the 2 lesions, it is not possible to entirely exclude the possibility that this unusual case could be due to asymmetric hyperplasia.
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PMID:Synchronous water-clear cell double parathyroid adenomas a hitherto uncharacterized entity? 1117 30

Adenomas of the parathyroid gland, the majority of which contain mixed cell populations, are the most frequent cause of primary hyperparathyroidism. Parathyroid adenomas composed exclusively of water-clear cells are exceptionally rare. Until now, only 2 cases have been reported in English literature. We report a water-clear cell adenoma of the parathyroid gland in an intrathyroidal position, which has not been described previously according to our knowledge.
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PMID:Intrathyroidal water-clear cell parathyroid adenoma: a case report. 1152 Dec 37

Recognition of the role of the extracellular calcium sensing receptor (CaR) in mineral metabolism has greatly improved our understanding of calcium homeostasis. The biology of the low affinity, G-protein-coupled CaR and the effects of its activation in various tissues are reviewed. Physiological roles include regulation of parathyroid hormone (PTH) secretion by small changes in ionized calcium (Ca++), and control of urinary calcium excretion with small changes in blood Ca++. The CaR also affects the renal handling of sodium, magnesium, and water. Mutations affecting the CaR that make it either less or more sensitive to Ca++ cause various clinical disorders. Disorders, such as primary and secondary hyperparathyroidism, may exhibit acquired abnormalities of the CaR. Calcimimetic drugs, which amplify the sensitivity of the CaR to Ca++, can suppress PTH levels with a resultant fall in blood Ca++. Experiences with R-568 in patients with secondary and primary hyperparathyroidism and parathyroid carcinoma are summarized. In humans with hyperparathyroidism, these agents produce a dose-dependent fall in PTH and blood Ca++, with larger doses causing more sustained effects. The second generation calcimimetic, AMG 073, with a better pharmacokinetic profile appears to be an effective and safe treatment for secondary hyperparathyroidism, producing suppression of PTH levels with a simultaneous reduction in serum phosphorus levels and the calcium X phosphorus product. The advantage of controlling PTH secretion without the complications related to hypercalcemia, hyperphosphatemia, and increased calcium X phosphorus product is very promising. Treatment trials have been relatively short-term except for one patient treated with R-568 for more than 600 days for parathyroid carcinoma; nonetheless the drug had no major side effects and appeared to be safe. Further long-term controlled studies are underway to further confirm the effectiveness and safety of these compounds.
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PMID:The calcimimetic agents: perspectives for treatment. 1198 29


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