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Query: UMLS:C0020437 (hypercalcemia)
 10,293 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cancer-associated hypercalcemia is due to the: (a) elaboration of systemically-acting humoral factors by neoplasms which alter calcium metabolism in bone, kidney, and intestine; or (b) stimulation of bone resorption at sites of tumor metastasis to bone. It is likely that both mechanisms occur in the same patient with certain neoplasms. There are many humoral factors that can be produced by tumors, secreted into the circulation, and have distant effects which induce hypercalcemia. The stimulation of increased osteoclastic bone resorption is a principal feature of humoral hypercalcemia of malignancy, but the kidney also plays an important role. In addition, intestinal absorption of calcium may be a factor in the pathogenesis of hypercalcemia in certain neoplasms. Parathyroid hormone-related protein plays a dominant role in the pathogenesis of HHM. PTHrP alone is able to induce nearly all of the clinical signs of HHM in experimental animals, but other humoral factors, such as cytokines, can interact with PTHrP to contribute to the development of hypercalcemia. Neoplasms which metastasize widely to bone and induce local osteoclastic bone resorption, such as multiple myeloma, also are capable of inducing hypercalcemia. Based upon existing data it is not clear what percentage of neoplasms which metastasize to bone and stimulate local bone resorption also are capable of stimulating hypercalcemia by systemic factors. Future research is needed to delineate the systemic and local factors associated with CAH; to define interactions of humoral factors in the pathogenesis of hypercalcemia; and to investigate the regulation of transcription, translation, modification, and secretion of hypercalcemia-inducing factors in normal and neoplastic tissues.
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PMID:Mechanisms of cancer-induced hypercalcemia. 146 Aug 60

Hypercalcemia with adult T-cell leukemia (ATL) is chiefly caused by an excessive production by tumor cells of parathyroid hormone-related protein (PTHrP). We have previously reported hypercalcemic patients with solid tumors to excrete a large amount of the C-terminal fragments of PTHrP (C-PTHrP) into their urine. To elucidate whether PTHrP production correlates with or predicts the development of hypercalcemia, we studied the urinary excretion of C-PTHrP in 36 ATL patients. The urinary excretion of C-PTHrP was in the normal range (< 0.40 nmol equivalent to PTHrP (109-141)/g creatinine) in HTLV-1-positive carriers (n 3), ATL patients in complete remission (n 2) and chronic type ATL patients (n 2). It was marginally increased in seven patients in partial remission, and gradually increased as the disease progressed. In 20 patients who died without or with hypercalcemia, it was increased to 1.98 +/- 0.69 (n 9) and 7.6 +/- 2.1 nmol/g creatinine (mean +/- SD, n 11, P < 0.01), respectively. Urinary C-PTHrP excretion was significantly correlated with serum calcium and LDH levels as well as with CD25-positive cells in the peripheral blood. In four patients whose urinary excretion had been serially determined, it increased prior to the development of hypercalcemia. The findings suggest the urinary excretion of C-PTHrP to be of use as a predictor of the development of hypercalcemia in ATL patients. In ATL patients whose urinary excretion of C-PTHrP is progressively increasing, the serum calcium concentration should be carefully monitored to prevent hypercalcemic crisis.
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PMID:Urinary excretion of parathyroid hormone-related protein as a predictor of hypercalcemia in patients with adult T-cell leukemia. 146 94

HTLV-I induced not only nodal but also primary extranodal lymphomas. In this report we describe 12 patients with HTLV-I induced extranodal T-cell lymphoma collected from the literature and our institute experience. There were 5 males and 7 female patients of middle age positive for HTLV-I antibody. The sites of primary tumor were gastrointestinal, Waldeyer's ring, skin, facial sinuses, and the pleura. All of these were histologically diffuse lymphomas and most of them were found to be a helper/inducer T-cell phenotype, showing integration of HTLV-I proviral DNA. Late leukemic changes and skin infiltration often occurred, but hypercalcemia was rare. Survival time varied from 4 to 35 months, and late organ infiltrations were common. These HTLV-I induced extranodal lymphomas were compared with HTLV-I unrelated extranodal lymphomas or HTLV-I induced nodal lymphomas (lymphoma type ATL). Between 1981 and 1990, we had 110 ATL patients and of these, 5 (4.6%) were HTLV-I induced primary extranodal lymphomas. The frequency of HTLV-I induced extranodal lymphoma might be much higher than expected because until now attention has not been paid to this entity. From the present review, it is suggested that HTLV-I could cause primary extranodal lymphoma which may have some different characteristics from other types of lymphoma. Therefore, patients with T-cell extranodal lymphomas should be investigated further for the presence of HTLV-I antibody and the tumor cells should be examined for the integration of HTLV-I proviral DNA using Southern blot analysis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:HTLV-I induced extranodal lymphomas. 147 32

A 59-year-old woman with primary hyperparathyroidism was found to have a parathyroid adenoma behind the left clavicle. Preoperatively, it appeared as a hypoechoic mass on ultrasonography, as a hot nodule on thallium scintigraphy, and as a high signal on T2-weighted magnetic resonance imaging. Histological, immunohistochemical and ultrastructural studies of the surgically resected tumor revealed a parathyroid adenoma composed mainly of oxyphil cells with production of a parathyroid hormone. Moreover, a multilocular lesion of lymphangiectasia was contained. Hypercalcemia was alleviated postoperatively. These observations corroborated a functioning parathyroid oxyphil cell adenoma. This is the first case report of functioning oxyphil cell adenoma of the parathyroid gland with lymphangiectasia in Japan.
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PMID:A case of primary hyperparathyroidism due to an oxyphil cell adenoma. 147 90

Intermittent courses of dexamethasone (DEX) were administered to 112 consecutive, previously untreated patients with multiple myeloma (MM). Using criteria based on a 75% or greater reduction of calculated tumor mass, the overall response rate was 43%. Among comparable patients, response rate were approximately 15% less than those observed previously with vincristine-doxorubicin by continuous infusion with intermittent DEX (VAD) and similar to those with melphalan-prednisone. The projected survival times with VAD or DEX were similar. Results indicated that DEX accounted for most of the plasma cell reduction achieved with VAD. Serious complications occurred in 27% of patients treated with VAD, but in only 4% of those who received DEX. In view of the similar outcome with fewer serious complications, DEX provided a simple, effective, and safe primary treatment for a large fraction of patients with MM. Patients who appear most likely to benefit include those with hypercalcemia or pancytopenia, or who require simultaneous radiotherapy for a pathologic fracture.
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PMID:Primary dexamethasone treatment of multiple myeloma. 149 31

Tumor-induced hypercalcemia and tumor-induced osteolysis are essentially due to a marked increase in osteoclast-mediated bone resorption, although the kidneys play an important contributory role in the genesis of tumor-induced hypercalcemia. Parathyroid hormone-like protein plays an essential role in tumor-induced hypercalcemia, and maybe in tumor-induced osteolysis, but other factors could also be responsible for the osteoclast activation secondary to the neoplastic infiltration of the skeleton. Treatment of tumor-induced hypercalcemia essentially consists of volume repletion and administration of potent anti-osteolytic drugs. The bisphosphonate pamidronate is particularly useful for that matter and a dose of 1.0 to 1.5 mg/kg can normalize serum calcium in about 90% of hypercalcemic cancer patients. The apparently low response rate of bone metastases to systemic antineoplastic therapy seems to essentially reflect the relative insensitivity of our current methods for assessing response in tumor-induced osteolysis. Newly developed biochemical markers of bone turnover could be particularly useful for that matter. Bisphosphonates are the most potent of the available inhibitors of osteoclast activity. Prolonged administration of oral pamidronate could reduce by almost one half the complications of tumor-induced osteolysis, and repeated bisphosphonate infusions could induce a dramatic relief of bone pain in one third and a sclerosis of lytic lesions in one fourth of the cases. These data must, however, be confirmed in randomized, blinded trials and many questions remain unanswered concerning the optimal therapeutic schemes. Medical therapy of tumor-induced osteolysis by noncytotoxic means has nevertheless become a reality.
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PMID:Bone metastases and tumor-induced hypercalcemia. 151 Oct 19

The ultrastructure of parathyroid chief cells was examined from four groups of nude mice (NIH:Swiss) with different serum calcium concentrations. The groups consisted of eight male mice with hypercalcemia induced by transplantable canine adenocarcinoma (CAC-8), eight female mice with hypercalcemia induced by infusion of parathyroid hormone-related protein, ten male control mice, and six male mice fed a low calcium (0.01%) diet. Hypercalcemia induced by malignancy or parathyroid hormone-related protein infusion was associated with low serum phosphorus concentration, a decrease in the number of secretory and prosecretory granules in the parathyroid chief cells, and an increase in the cytoplasmic area of chief cells. Prominent myelinlike membranous whorls were present in the cytoplasm of chief cells of tumor-bearing and parathyroid hormone-related protein-infused hypercalcemic mice. Mice fed a low calcium diet had decreases in the number of secretory granules and cell area but increases in the number of prosecretory granules compared with control mice. The number of mitochondria and the nuclear area of chief cells were similar in all four groups. The prominent membranous whorls and increased cytoplasmic area of chief cells from these hypercalcemic mice mark these cells as distinctly different from the parathyroid chief cells of other species with hypercalcemia.
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PMID:Effects of humoral hypercalcemia of malignancy on the parathyroid gland in nude mice. 151 21

Parathyroid carcinoma accounts for 0.5 to 5% of all cases of hyperparathyroidism. We reviewed the clinical, surgical, and pathologic features observed in all patients with parathyroid carcinoma evaluated at the Mayo Clinic from 1920 through 1991. Forty-three patients (22 women, 21 men; mean age, 54 yrs, range 29-72) were identified, including 2 with familial hyperparathyroidism. Information on initial presentation was available in 40 patients: 15 (38%) presented with polydipsia or polyuria, 11 (27%) with myalgias or arthralgias, 7 (17%) with weight loss, and 4 (10%) with nephrolithiasis; 3 patients (7%) were asymptomatic at presentation. Of 31 patients in whom the initial neck examination was recorded, 14 (45%) had a palpable neck mass. The mean serum calcium and serum phosphorus levels were 14.6 mg/dl and 2.3 mg/dl, respectively. Parathyroid hormone levels were elevated in 21 of 21 patients (mean elevation, 10.2 times upper limit of normal). Complications included nephrolithiasis in 14 of 25 patients (56%), bone disease in 20 of 22 patients (91%) and both in 8 of 15 patients (53%). All patients underwent primary surgical resection of parathyroid carcinoma. Twenty-six of 43 patients (60%) required a second operation with 18 patients requiring multiple re-explorations. At the second operation, residual tumor was found in the neck (68%), mediastinum (16%), or both (12%). Six patients received radiation therapy to the neck (5 patients) or bones (1 patient) for recurrent or metastatic disease. Of these, 1 patient appeared cured of parathyroid carcinoma by radiation therapy 11 years after documented tumor invasion of his trachea. Repeated excision of tumor recurrences was an effective means of controlling hypercalcemia in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Parathyroid carcinoma: clinical and pathologic features in 43 patients. 151 93

Tumour cells produce systemic or local factors which can stimulate osteoclast development and activity leading to increased bone resorption. The clinical consequences are bone pain, fractures and hypercalcaemia. Inhibitors of osteoclast-mediated bone resorption, such as the bisphosphonates, are now the treatment of choice for tumour-induced hypercalcaemia. Recent evidence indicates that these compounds, especially the newer ones, reduce skeletal morbidity in patients with metastatic bone disease and improve their quality of life. Better understanding of the mechanisms underlying tumour-induced bone resorption and development of more potent and less toxic bisphosphonates will lead to improved management of patients with malignant diseases involving the skeleton.
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PMID:Modulation of tumour-induced bone resorption by bisphosphonates. 152 54

The calcium channel antagonists (CCAs) amlodipine, diltiazem, and verapamil inhibited HT-39 human breast cancer cell proliferation in a concentration-dependent manner. The apparent 50% inhibitory dose values were 1.5 microM for the dihydropyridine amlodipine, 5 microM for the benzothiazapine diltiazem, and 10 microM for the phenylalkylamine verapamil. Amlodipine treatment caused a rapid concentration-dependent decrease of intracellular calcium concentration in the HT-39 cell line. Addition of 1 microM amlodipine had no effect on intracellular calcium levels, 3 microM amlodipine lowered intracellular calcium levels in the HT-39 cells by 13.7%, and 10 microM amlodipine lowered intracellular calcium levels by 33.2%. Also, lowering medium calcium levels from 2.0 mM to 0.5 microM resulted in a rapid 41.3% decrease in intracellular calcium and a concomitant 60% inhibition of HT-39 cell DNA synthesis. When HT-39 cells were transplanted into athymic mice, marked hypercalcemia developed. Serum calcium levels from control mice were 8.3 +/- 0.6 mg/dl (mean +/- SE; n = 4); those from tumor-bearing mice were 11.3 +/- 0.08 mg/dl (mean +/- SE; n = 17). Blood calcium levels correlated directly with tumor size (r = 0.91, P less than 0.01). We examined the capacity of three CCAs to specifically inhibit HT-39 tumor growth in vivo. One week after inoculation of HT-39 cells, mice were acclimated to vehicle or 0.1 mg/day amlodipine, 1.0 mg/day diltiazem, or 1.0 mg/day verpamil, in their drinking water, for 7 days. Oral administration of the dihydropyridine amlodipine (0.35 mg/day) for 10 days inhibited HT-39 breast tumor growth by 83.5 +/- 20.1% (mean +/- SE). Oral administration of diltiazem (3.5 mg/day) inhibited HT-39 breast tumor growth rate by 46.5 +/- 6.6% over a 2-week measurement period, and verapamil (3.5 mg/day) inhibited tumor growth rate by 68.2 +/- 9.7% (mean +/- SE). The CCAs had no effect on mouse body weight or gross organ morphology at the concentrations used. Lack of depolarization-induced calcium fluxes in the HT-39 cell line suggests that these cells do not express voltage-operated calcium channels. Thus, our study correlates an effect of amlodipine to lower intracellular calcium levels, by a mechanism not known at present, with its effect to inhibit HT-39 cell proliferation. These findings are important since they demonstrate that amlodipine and other CCAs with known pharmacodynamics and side effects act to blunt breast tumor progression in vivo.
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PMID:Inhibition of cancer cell growth by calcium channel antagonists in the athymic mouse. 153 73


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