UMLS:C0221002 - FACTA Search

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)

The usefulness of intraoperative parathyroid hormone (PTH) monitoring has been extensively documented in primary hyperparathyroidism (HPT), whereas few data have been published on its use in reoperations or in secondary and tertiary HPT. We report our initial experience with a rapid (12 min response) PTH immunochemiluminometric assay performed in the operating room during surgery in 12 patients with primary HPT, 16 end-stage renal disease patients with secondary HPT and five kidney transplanted subjects with tertiary HPT. Blood samples were taken at baseline, within 10 min after resection and subsequently at various intervals whenever needed. The mean PTH levels before and after parathyroidectomy were 230.5 pg/mL (range 69-842) and 47.3 pg/mL (range 5-184), respectively, in primary HPT, 855.0 pg/mL (416-1655) and 202.2 pg/mL (53-440) in secondary HPT, and 205.6 pg/mL (116-301) and 45.4 pg/mL (18-97) in tertiary HPT. All patients but one had a significant percentage decline from pre-excision values (mean 76.9%, 76.0%, and 76.1% in primary, secondary and tertiary HPT, respectively). While a reduction of more than 50% was observed in 30 out of 33 patients after the first intraoperative sampling, additional measurements were performed in 10 cases. On-site PTH monitoring with this user-friendly and reliable system has proved helpful in targeting PTH tests to give the surgeon a rapid and accurate assessment of the intervention. The development of optimal PTH sequence strategies with decision-focused analytical and clinical limits will improve the efficacy of "point-of-care" PTH assay and resource utilization.
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PMID:Optimizing efficacy of quick parathyroid hormone determination in the operating theater. 1088 89

Background: Parathyroid hormone (PTH) and parathyroid hormone-related protein (PTH-rP) are two potent hypercalcemic hormones that act on the same targets. Autonomous secretion of the former is involved in primary hyperparathyroidism (PHPT), whereas the latter is responsible for humoral hypercalcemia of malignancy (HHM). Methods: From 250 consecutive, hypercalcemic serum samples sent to our laboratory for assessment of intact PTH, we were able to obtain clinical information, as well as an additional plasma sample for PTH-rP measurement, in 134 patients. At the time of sampling, patients could be classified into seven groups: cancer without known bone metastases (CaNoMeta, n=36), cancer with bone metastases (CaMeta, n=9), no evidence of cancer (noEvCa, n=71), sarcoidosis (Sarc, n=3), end-stage renal disease (ESRD, n=12), vitamin D overdose (VIT-D, n=2), and hyperthyroidism (Thyr, n=1). Results: In the CaNoMeta group, 29/36 patients had elevated PTH-rP levels, 9/36 patients had inappropriately elevated PTH levels, and 5/36 had elevated levels of both hormones. In the CaMeta group, three of the nine patients had inappropriately elevated PTH levels, two of them with concomitantly elevated PTH-rP levels. In the NoEvCa group, 63/71 patients had an inappropriate elevation of PTH levels and were diagnosed as having PHPT. Four of the 71 patients had elevated levels of both PTH and PTH-rP; three of them were in poor health and died within a short period of time. All of the ESRD patients had very high PTH and normal PTH-rP levels, except for one woman with high PTH-rP and undetectable PTH levels; she died from what later turned out to be a recurrent bladder carcinoma. In the Sarc, Vit-D, and Thyr groups, both PTH and PTH-rP levels were normal. Conclusions: (1) Elevated PTH-rP levels are a common finding in cancer patients without bone metastases. Intact PTH, however, should always be measured in hypercalcemic patients with malignancy because concurrent primary hyperparathyroidism is not rare. (2) Primary hyperparathyroidism accounts for hypercalcemia in 90% of patients without evidence of cancer whose PTH-rP levels may also be found to be elevated in a few cases, even some with surgically demonstrated parathyroid adenoma.
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PMID:Diagnostic approach to hypercalcemia: relevance of parathyroid hormone and parathyroid hormone-related protein measurements. 1139 97

Calcimimetic agents are small organic molecules that act as allosteric activators of the calcium sensing receptor. They lower the threshold for receptor activation by extracellular calcium ions and, in parathyroid cells, diminish parathyroid hormone secretion. Calcimimetic compounds represent a novel class of therapeutic agents that may provide a way of controlling excess parathyroid hormone secretion in several clinical disorders. Although experience from clinical trials in humans is limited, available data suggest that calcimimetic agents effectively lower plasma parathyroid hormone levels in patients with primary hyperparathyroidism and those with secondary hyperparathyroidism caused by end-stage renal disease. Calcimimetic compounds thus have considerable potential as a new approach to the medical management of several important clinical disorders of bone and mineral metabolism.
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PMID:Calcimimetic agents for the treatment of hyperparathyroidism. 1149 49

Biologically active parathyroid hormone (PTH) in humans with normal renal function circulates predominantly as an 84 amino acid peptide. PTH fragments of varying length arise either from metabolism of the intact hormone within the parathyroid glands or in peripheral tissues, such as liver, and the resulting carboxyl-terminal peptides are eliminated mainly by glomerular filtration and subsequent tubular degradation. Most of the initially raised anti-PTH antisera were directed against epitopes within the mid- or carboxyl-terminal regions of the hormone. These antibodies were used for the development of conventional, displacement-type radioimmunoassays, but provided only an index of the biologically active PTH(1-84) in the circulation. Subsequently developed immunometric assays use two distinct antibodies, a capture antibody usually directed against a carboxyl-terminal portion of PTH(1-84) and a radio- or enzyme-labeled detection antibody usually directed against the amino-terminal portion of the hormone. Such assays were thought to detect largely, if not exclusively, intact PTH, thus providing the concentration of biologically active hormone in blood, which is especially important for establishing the diagnosis of hyperparathyroidism. However, serum samples from normal subjects and patients with primary or secondary hyperparathyroidism have demonstrated that most immunometric two-site sandwich assays detect, besides PTH(1-84), one or more recently discovered large carboxyl-terminal PTH fragments that lack a portion of the amino-terminal end of the molecule. Some of these amino-terminally truncated PTH molecules [ntPTH(1-84)] exhibit an elution profile on high performance liquid chromatography (HPLC) that is indistinguishable from that of synthetic PTH(784). Such peptides were previously thought to be of minimal if any biological activity, but recent studies have shown that synthetic PTH(7-84) has hypocalcemic properties in vivo and that it inhibits osteoclastic bone resorption and the formation of mature osteoclasts in vitro. It is currently unclear whether important differences in disease states can be revealed by comparing results obtained with older immunometric assays that measure the full-length hormone and ntPTH(1-84) versus newer assays that measure only PTH(1-84). Therefore, whereas most immunometric PTH assay systems are appropriate for the diagnosis of primary hyperparathyroidism, it is possible that immunometric assays designed to detect only PTH(1-84) will be more useful in certain diagnostic studies, for intraoperative PTH monitoring and for assessing the pulsatility of PTH secretion. In addition, the ability to distinguish between the relative concentrations of ntPTH(1-84) versus PTH(1-84) may reveal previously unsuspected roles for the ntPTH(1-84) fragments in the pathophysiology of patients with end-stage renal disease and/or other disorders involving parathyroid hormone.
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PMID:Immunoassays for the detection of parathyroid hormone. 1241 82

Calciphylaxis is a poorly understood and highly morbid syndrome of vascular calcification and skin necrosis. Hypercalcemia, hyperphosphatemia, and secondary hyperparathyroidism are the factors implicated in the pathogenesis of calciphylaxis, which is generally identified in patients with hyperparathyroidism secondary to end-stage renal disease. It has also been observed in primary hyperparathyroidism, end-stage liver disease, and rheumatoid arthritis, in the absence of renal disease. There are few case reports of calciphylaxis occurring in hypercalcemia of malignancy. An unusual case is reported of calciphylaxis associated with malignant melanoma of the soft parts in the absence of renal or parathyroid disease. This is the first reported case of this soft tissue sarcoma showing calciphylactic changes.
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PMID:Malignant melanoma of the soft parts showing calciphylaxis. 1255 24

Hypercalcemic nephropathy has been classified as a tubulointerstitial renal disease. The presence of glomerular pathologic findings attributable to hypercalcemia has been observed in only a few patients and therefore has been considered an unusual finding. In the current study, calcium deposition within glomeruli was investigated in 2 patients with extreme elevations in serum calcium levels and hypercalcemic nephropathy. The study material consisted of a renal biopsy specimen from a 31-year-old woman (patient 1) who had T-cell lymphoma/leukemia and a serum calcium level of 20.2 mg/dL (5.0 mmol/L) and autopsy kidney specimens from a 19-year-old woman (patient 2) who was being evaluated for primary hyperparathyroidism and a calcium level of 18.4 mg/dL (4.6 mmol/L). The renal biopsy specimen for patient 1 exhibited calcium deposits present in the glomerular capillary basement membranes, where they were associated with segmental sclerosing lesions (21% of glomeruli). Nine percent of the cortical tubules contained calcifications. In patient 2, calcium was found in the mesangial areas in 95% of glomeruli, filling the Bowman space in 7% of glomeruli, or associated with capillary basement membranes and segmental sclerosing lesions (12% of glomeruli). Fifteen percent of cortical tubules, 4% of outer medullary tubules, and 40% of inner medullary tubules were calcified. In neither case was there immunofluorescence or electron microscopic evidence of primary glomerular disease. Thus, glomerular calcification may exceed that occurring in the cortical and outer medullary tubules and may play a significant role in the loss of renal function in hypercalcemic nephropathy. Glomerular calcinosis may also be recognized as an additional cause of segmental glomerulosclerosis and nephrotic range proteinuria in patients with extremely high levels of serum calcium.
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PMID:Glomerular calcification in hypercalcemic nephropathy. 1256 59

Thirteen patients, who received parathyroidectomy within 5 years after the initiation of hemodialysis, were discussed on their clinical characteristics and their prognoses. 204 patients received the first parathyroidectomy due to secondary hyperparathyroidism in our department, 13 of which were selected on dialysis duration. 9 patients were female and origin of CRF were analgesics-induced interstitial nephritis in 2 and prune-belly syndrome in 1. There were 2 patients who suffered from renal disease more than 30 years. Concomitant primary hyperparathyroidism was suspected in 1 case. In all cases, PTx achieved adequate control of 2HPT after the operation.
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PMID:[Characteristics of the patients who received parathyroidectomy within 5 years after the initiation of hemodialysis]. 1593 Jul 22

Circulating levels of calcium ion (Ca2+) are maintained within a narrow physiological range mainly by the action of parathyroid hormone (PTH) secreted from parathyroid gland (PTG) cells. PTG cells can sense small fluctuations in plasma Ca2+ levels by virtue of a cell surface Ca2+ receptor (CaR) that belongs to the superfamily of G protein-coupled receptors (GPCR). Compounds that activate the CaR and inhibit PTH secretion are termed 'calcimimetics' because they mimic or potentiate the effects of extracellular Ca2+ on PTG cell function. Preclinical studies with NPS R-568, a first generation calcimimetic compound that acts as a positive allosteric modulator of the CaR, have demonstrated that oral administration decreases serum levels of PTH and calcium, with a leftward shift in the set-point for calcium-regulated PTH secretion in normal rats. NPS R-568 also suppresses the elevation of serum PTH levels and PTG hyperplasia and can improve bone mineral density (BMD) and strength in rats with chronic renal insufficiency (CRI). Clinical trials with cinacalcet hydrochloride (cinacalcet), a compound with an improved metabolic profile, have shown that long-term treatment continues to suppress the elevation of serum levels of calcium and PTH in patients with primary hyperparathyroidism (1HPT). Furthermore, clinical trials in patients with uncontrolled secondary hyperparathyroidism (2HPT) have demonstrated that cinacalcet not only lowers serum PTH levels, but also the serum phosphorus and calcium x phosphorus product; these are a hallmark of an increased risk of cardiovascular disease and mortality in dialysis patients with end-stage renal disease. Indeed, cinacalcet has already been approved for marketing in several countries. Calcimimetic compounds like cinacalcet have great potential as an innovative medical approach to manage 1HPT and 2HPT.
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PMID:Pharmacological and clinical properties of calcimimetics: calcium receptor activators that afford an innovative approach to controlling hyperparathyroidism. 1610 39

Calciphylaxis is a relatively rare disorder associated with calcification of small- and medium-sized blood vessels, progressive ischemic skin necrosis, and ulcerations. It is usually seen in patients with end-stage renal disease with secondary hyperparathyroidism and is occasionally seen in primary hyperparathyroidism, hypercalcemia of malignancy, and end-stage liver disease. We report an unusual case of calciphylaxis seen in association with metastatic breast carcinoma in the absence of end-stage renal or parathyroid disease. A 73-year-old woman presented with painful leg ulcers. Serum calcium levels and parathormone levels were within normal limits. Skin biopsies from the ulcers revealed small- to medium-sized subcutaneous arteries with calcification of the media. Some of the arteries were narrowed by fibrointimal hyperplasia and fibrin thrombi. Calcification of the subcutaneous fat, fat necrosis, and suppuration were also seen. Calciphylaxis associated with metastatic osteolytic breast carcinoma is rare. Although end stage renal disease with secondary hyperparathyroidism is the most common cause of calciphylaxis, this case demonstrates that less common conditions with normal serum calcium and parathormone levels may also cause it.
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PMID:Unusual case of calciphylaxis associated with metastatic breast carcinoma. 1766 77

We present a 45 year old female who was initially seen by Rheumatologist with long standing knee pain affecting her mobility. She was found to be severely hypercalcaemic and exhibited features suggestive of parathyroid carcinoma (palpable neck mass, extremely high parathyroid hormone, high alkaline phosphatase, concomitant presence of renal disease and skeletal involvement). Hence she was referred for parathyroidectomy. Postoperatively she developed profound hypocalcaemia with markedly raised serum alkaline phosphatase, requiring intensive intravenous calcium and oral vitamin D supplements, consistent with the development of hungry bone syndrome (HBS). HBS is a complication of parathyroid surgery where the correction of primary hyperparathyroidism is associated with rapid bone remineralisation, causing severe and prolonged hypocalcaemia. HBS is relatively rare but has to be considered in the differential diagnosis of postoperative hypocalcaemia particularly in severe cases. In the current report, we discuss pathogenesis, clinical course and management of HBS.
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PMID:A case of parathyroid carcinoma with severe hungry bone syndrome and review of literature. 1809 36

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