Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020437 (hypercalcemia)
 10,293 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe a case of hypercalcaemia secondary to recurrent malignant phaeochromocytoma. Parathyroid-related protein (PTHrp 1-86) immunoreactivity was identified in plasma and PTHrp was identified by immunocytochemistry in tumour tissue.
 ...
PMID:Malignant phaeochromocytoma and hypercalcaemia. 844 62

Parathyroid cysts are uncommon. They can be divided into functional and nonfunctional cysts depending on whether or not they are associated with hypercalcemia. Functioning cysts are very rare with less than twenty reported cases. We report a case of functioning parathyroid cyst associated with hypocalciuric hypercalcemia. We have been unable to find a similar case previously reported in the literature.
 ...
PMID:Functional parathyroid cyst and hypocalciuric hypercalcemia. 848 54

Parathyroid-hormone-related protein (PTHrP) has been implicated in the origin of malignant hypercalcaemia. However, PTHrP production is not restricted to neoplastic cells, it is widespread among a variety of normal cell types and tissues. A physiological role for PTHrP has not been well defined. We describe a case of breast cancer with bone metastases and humoral hypercalcaemia of malignancy, with high levels of plasma C-terminal parathyroid hormone (PTH), mid-molecule PTH and PTHrP. Cells from breast cancer biopsies were cultured and medium samples assayed for the C-terminal and mid-molecule fragments, intact PTH and PTHrP. The data indicate a progressive increase in both PTH fragments and PTHrP levels, over a period of 30 days. No temporal parallelism exists between PTH fragments and PTHrP concentrations, the former being maximum at the 14th day, and the latter at the 30th day from the beginning of the culture. Our results indicate a coproduction of PTH and PTHrP by the breast cancer cells both in vivo and in vitro.
 ...
PMID:Production of parathyroid hormone and parathyroid-hormone-related protein by breast cancer cells in culture. 849 63

Parathyroid cysts are uncommon. They can be divided into functional and nonfunctional cysts depending on whether or not they are associated with hypercalcemia. Functioning cysts are very rare, with fewer than twenty reported cases. We report a case of functioning parathyroid cyst associated with hypocalciuric hypercalcemia. We have been unable to find a similar case previously reported in the literature.
 ...
PMID:Functional parathyroid cyst and hypocalciuric hypercalcemia. 852 50

Amphibians living partially or totally in a terrestrial environment are the first tetrapods to possess parathyroid glands. Purely aquatic amphibians and amphibian larvae lack these endocrine glands. The parathyroids develop at the time of metamorphosis. The parathyroid glands in caecilians consist of a single cell type, that of urodeles may be composed of basal (supporting) cells and suprabasal (chief) cells, and that of anurans of small and large chief cells. Parathyroid glands of caecilians and anurans lack connective tissue, blood vessels, and nerves. The parathyroid cells become activated in response to decreased blood calcium concentration and undergo changes indicating increased parathyroid hormone secretion. Increased blood calcium concentration suppresses secretory activity. Usually, parathyroidectomy elicits hypocalcemia in most amphibians. Such operations have no effect in lower urodeles. Parathyroid hormone administration provokes hypercalcemia in most amphibians. The parathyroids of caecilians have not been studied in detail. The urodeles and anurans exhibit seasonal changes in the parathyroid glands. These changes may be initiated by environmental stimuli such as light, temperature, or alterations in blood calcium levels caused by natural hibernation.
 ...
PMID:Amphibian parathyroids: morphological and functional aspects. 858 May 12

Identification of germline mutations in the RET proto-oncogene predisposing to multiple endocrine neoplasia type IIa (MEN-IIa) has allowed a DNA-based approach to diagnosis and treatment by prophylactic thyroidectomy in children testing genetically positive. Although total thyroidectomy is the accepted operation for C cell disease, the necessity of routine total parathyroidectomy and autotransplantation as previously described in these asymptomatic children is questionable, particularly given the low occurrence of hyperparathyroidism in MEN-IIa (10-20%). Thirty-six children (ages 1 month to 12 years) from four MEN-IIa kindreds at risk for disease underwent genetic testing. Mutational analysis was done using a highly sensitive PCR-based denaturing gradient gel electrophoresis technique. Parathyroid or serum calcium concentrations were determined preoperatively. Of the 36 children at risk, 18 were found to have a MEN-IIa mutation; 11 have undergone prophylactic thyroidectomy at ages ranging from 2 to 12 years (mean 7.5 years). In each case, there was no biochemical evidence of hypercalcemia preoperatively, and all parathyroid glands were identified and were found to be grossly normal at exploration. Glands were carefully dissected and left in situ. Postoperatively, 10 of the 11 children maintained normocalcemia, allowing discharge within 24 to 36 hours. Resected thyroid glands contained C cell hyperplasia in nine, medullary carcinoma in one, and normal histology in one. We conclude that an alternative to routine parathyroidectomy may be desirable for prophylactic treatment of MEN-IIa. In situ parathyroid preservation can be safely achieved without compromising the completeness of the thyroid resection. This conservative approach obviates the potential morbidity associated with total parathyroidectomy and autotransplantation.
 ...
PMID:Prophylactic surgery for multiple endocrine neoplasia type IIa after genetic diagnosis: is parathyroid transplantation indicated? 867 56

Parathyroid tissue from 57 women (mean age 65.5 years) with sporadic primary hyperparathyroidism (HPT) was analyzed mainly to clarify its characteristics versus tissue from those with normocalcemia. Patients were recruited by population-based health screening of menopausal women. Analysis of three or four total serum calcium values showed normocalcemia in 16 patients (mean 2.53 mmol/L); 20 and 21 of the women were consistently (mean 2.82 mmol/L) or intermittently (mean 2.59 mmol/L) hypercalcemic, respectively. Parathyroid operation demonstrated a single adenoma in 81% of the individuals, and these lesions were most prevalent and commonly dominated by oxyphil parathyroid cells in the persistently hypercalcemic patients. Chief cell hyperplasia (two or three abnormal glands) of the nodular type was found more often in the normocalcemic patients. Total glandular weight was the smallest (mean 270 mg) among the normocalcemic women and contributed to delicate decisions with regard to the extent of resection. Immunostaining of cryosections with a monoclonal antibody recognizing a putative Ca2+ sensor demonstrated variably heterogeneous down-regulation of the recognized glycoprotein in the pathologic parathyroid glands from all the individuals. Dose-response relations for PTH release and the cytoplasmic Ca2+ concentration ([Ca2+]i) were determined in Ca2+ 0.5-3.0 mmol/L by examining dispersed cells with radioimmunoassay and microfluorometry after fura-2 loading, respectively. ED50 for PTH release and [Ca2+]i and the [Ca2+]i concentrations at Ca2+ 3.0 mmol/L were the least deranged in cells from pathologic glands of the normocalcemic patients. The findings substantiate that the abnormal parathyroid tissue of normocalcemic HPT principally is characterized by the same, albeit less extensive, morphologic and functional derangements, which consistently have been demonstrated in patients with HPT accompanied by hypercalcemia and detected clinically.
 ...
PMID:Parathyroid tissue in normocalcemic and hypercalcemic primary hyperparathyroidism recruited by health screening. 867 73

Breast cancer patients frequently develop bone metastases. A newly discovered peptide, Parathyroid Hormone Related Protein (PTHrP), causes humoral hypercalcaemia of malignancy. We have studied whether production of this protein by breast cancers leads to the development of bone metastases or hypercalcaemia. PTHrP was produced by nearly 60% of early breast cancers and its production by the tumours was associated with malignant mammographic microcalcification, and the development of both bone metastases and hypercalcaemia. The hypercalcaemia associated with bone metastases has been shown to have a significant humoral component and measurement of plasma PTHrP in patients with hypercalcaemia is diagnostically useful. Potential mechanisms of preventing bone metastasis are discussed.
 ...
PMID:Parathyroid hormone-related protein, bone metastases and hypercalcaemia of malignancy. 871 50

The main factors which regulate parathyroid hormone (PTH) production are calcium, phosphate, vitamin D and the sex steroids, estrogens and progestagins. Hypocalcaemia leads to increased PTH secretion in seconds and minutes, gene expression in hours and parathyroid cell number in weeks and months. Hypercalcaemia leads to a decrease in PTH secretion by its action on the parathyroid cell calcium receptor and no decrease in PTH mRNA concentrations. There is now convincing evidence that phosphate regulates the parathyroids independent of its effect on serum calcium and 1,25-dihydroxyvitamin D3. (1,25(OH)2D3). In vivo in rats hypophosphataemia markedly decreases PTH mRNA and serum PTH independent of its effect on serum calcium and 1,25(OH)2D3. Clinical studies also indicate that phosphate regulates the parathyroids independent of its effect on serum calcium and 1,25(OH)2D3 1,25(OH)2D3 itself has a marked effect on the parathyroids where it decreases PTH gene transcription by a direct action. Parathyroid cell proliferation is regulated by dietary calcium and phosphate with hypocalcaemia markedly increasing and hypophosphataemia markedly decreasing the number of proliferating cells. The application of basic science findings of how calcium, phosphate and 1,25(OH)2D3 regulate the parathyroids has led to an efficient and safe prescription for the management of the secondary hyperparathyroidism of chronic renal failure which is the maintenance of a normal serum calcium and phosphate and the careful use of bolus doses of 1,25(OH)2D3.
 ...
PMID:New insights into the regulation of parathyroid hormone synthesis and secretion in chronic renal failure. 884 Mar 3

Primary hyperparathyroidism is caused by an ectopically located parathyroid adenoma in a small percentage of cases. Parathyroid adenomas located within the retrosternal area of the anterior mediastinum account for a large proportion of failed initial cervical explorations. Current surgical approach to these lesions is via median sternotomy, with the discomfort, hospitalization, and morbidity associated with a major thoracic operation. We report a new technique for the resection of these ectopic parathyroid adenomas after successful radiologic localization: a minimally invasive subxiphoid laparoscopic approach. The procedure was performed in a symptomatic patient with documented primary hyperparathyroidism who had failed three previous neck operations. The ectopic parathyroid adenoma was successfully resected endoscopically, with resolution of the hypercalcemia. The patient was discharged on the third postoperative day, avoiding completely the morbidity of a median sternotomy.
 ...
PMID:The subxiphoid laparoscopic approach for resection of mediastinal parathyroid adenoma after successful localization with TC-99m-sestamibi radionuclide scan. 884 87


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>