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

Although hypercalcemia, osteoporosis, and increased bone turnover are associated with thyrotoxicosis, no direct effects of thyroid hormones on bone metabolism have been reported previously in organ culture. We have now demonstrated that prolonged treatment with thyroxine (T4) or triiodothyronine (T3) can directly increase bone resorption in cultured fetal rat long bones as measured by the release of previously incorporated 45Ca. T4 and T3 at 1 muM to 10 nM increased 45Ca release by 10-60% of total bone 45Ca during 5 days of culture. The medium contained 4 mg/ml of bovine serum albumin to which 90% of T4 and T3 were bound, so that free concentrations were less than 0.1 muM. The response to T4 and T3 was inhibited by cortisol (1 muM) and calcitonin (100 mU/ml). Indomethacin did not inhibit T4 response suggesting that T4 stimulation of bone resorption was not mediated by increased prostaglandin synthesis by the cultured bone. Matrix resorption was demonstrated by a decrease in extracted dry weight and hydroxyproline concentration of treated bones and by histologic examination which also showed increased osteoclast activity. The effects of thyroid hormones were not only slower than those of other potent stimulators of osteoclastic bone resorption (parathyroid hormone, vitamin D metabolites, osteoclast activating factor, and prostaglandins), but the maximum response was not as great. We conclude that T4 and T3 can directly stimulate bone resorption in vitro at concentrations approaching those which occur in thyrotoxicosis. This effect may explain the disturbances of calcium metabolism seen in hyperthyroidism.
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PMID:Direct stimulation of bone resorption by thyroid hormones. 18 21

A retrospective study of 22 hypertensive patients who were treated with thiazide diuretics for 2 to 12 yr revealed that 36% developed transient, self-limited asymptomatic elevations of serum calcium which occurred at varying periods of therapy and returned to normal within 2 to 4 wk despite continued administration of thiazides. These episodes of hypercalcemia correlated positively with increases in total protein, albumin, and globulin. The same phenomenon of intermittent hypercalcemia occurred in a prospective study of 11 patients but not in control subjects. The mean serum total calcium of the prospectively studied hydrochlorothiazide-treated patients was found to be higher than the nonthiazide control group. This difference was due to increased protein-bound calcium. The total proteins, serum albumin, and serum beta globulins of the treated group were higher, probably due to depletion of extracellular fluid. The presence of slightly elevated serum calcium in a patient treated with thiazides appears to be a common phenomenon and, unless it is marked, should not necessarily be construed as indicating covert hyperparathyroidism.
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PMID:Effect of thiazides on serum calcium. 46 32

When correction was made for hypoalbuminaemia, 23 of 50 ambulant patients with definite or classical rheumatoid arthritis were found to have hypercalcaemia. When these 23 patients were studied 6 months later, 7 had hypercalcaemia as defined by the correction factor for a low serum albumin level, and 6 of these patients had raised serum ionised calcium concentrations. Biochemical studies in the 23 patients indicated evidence of hyperparathyroidism, namely, hypophosphataemia, increased serum alkaline phosphatase, hyperchloraemia, and reduced tubular reabsorption of calcium. However, serum immunoreactive parathyroid hormone concentrations were normal. Only one patient had an abnormally low serum 25-hydroxy-vitamin D result: this patient had a high level of urinary D-glucaric acid and was receiving phenobarbitone for treatment of epilepsy. The biochemical features suggestive of parathyroid overactivity were particularly found in patients with raised serum calcium levels. The cause of hypercalcaemia in rheumatoid arthritis remains to be explained.
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PMID:Hypercalcaemia in rheumatoid arthritis: investigation of its causes and implications. 51 39

Serum immunoreactive parathyroid hormone (S-iPTH) was measured together with serum and urinary calcium and phosphorus in 45 hyperthyroid patients in order to assess parathyroid fe of hyperthyroidism. The prevalence of hypercalcaemia was 51.1% using serum calcium values corrected for individual variations in serum albumin concentration compared to 15.6% using the uncorrected calcium values. S-iPTH was decreased and inversely correlated to serum calcium values. S-iPTH was decreased and inversely correlated to serum calcium (corrected). Subnormal levels of S-iPTH were found in 28.9% of the patients. The urinary excretion of calcium and phosphorus was increased and positively correlated to the degree of hyperthyroidism. The tubular reabsorption of calcium (TRCa%) was decreased, positively correlated to S-iPTH and inversely correlated to serum calcium. Increased mobilisation of bone mineral in hyperthyroidism is suggested mainly to be responsible for the elevated serarathyroid function.
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PMID:Decreased parathyroid function in hyperthyroidism: interrelationships between serum parathyroid hormone, calcium-phosphorus metabolism and thyroid function. 57 31

Serum calcium and albumin levels were measured in 255 patients with a confirmed diagnosis of malignant disease. The average serum calcium and albumin levels were similar to those reported in an earlier larger American survey. Only 6/255 patients were above the normal range of corrected serum calcium and one patient was sufficiently hypercalcaemic (corrected serum calcium at least 2.8 mmol/L) to be included in a trial of oral clodronate therapy. The incidence of hypercalcaemia in this survey is considerably lower than that reported in the published literature (5-10%). A much larger proportion of patients (21/255) were hypocalcaemic. Serum albumin was depressed in 25/255 cases and elevated in 2/255 cases.
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PMID:A multicentre survey of serum calcium levels in patients with malignant diseases. 147 52

Hypercalcemia is a major source of morbidity and mortality in patients with cancer. Gallium nitrate and the bisphosphonate, etidronate, are new agents that have recently become available for treatment of this disorder. To directly compare therapeutic effectiveness, we conducted a randomized, double-blind, multicenter study of gallium nitrate compared with etidronate for acute control of cancer-related hypercalcemia. Gallium nitrate was administered by continuous intravenous (IV) infusion at a dose of 200 mg/m2/d. Etidronate was administered as a 4-hour IV infusion at a dose of 7.5 mg/kg. Both drugs were given daily for 5 consecutive days. Eligible patients had persistent moderate-to-severe hypercalcemia (total serum calcium [corrected for serum albumin] greater than or equal to 12.0 mg/dL) after 2 days of hospitalization and IV hydration. Seventy-one patients were randomized and treated. Twenty-eight of 34 patients (82%) who received gallium nitrate achieved normocalcemia compared with 16 of 37 patients (43%) who received etidronate (P less than .001). Patients who received etidronate required significantly greater amounts of IV fluids (P = .04) and more hypocalcemic drug treatment (P less than .05) during the poststudy period than patients who received gallium nitrate. Kaplan-Meier analysis showed a significantly longer median duration of normocalcemia for patients treated with gallium nitrate (8 days v 0 days, P = .0005). A significantly higher proportion of patients treated with gallium nitrate developed asymptomatic hypophosphatemia compared with patients treated with etidronate (97% v 43%, P less than .001). We conclude that gallium nitrate is highly effective and superior to etidronate for acute control of moderate-to-severe cancer-related hypercalcemia.
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PMID:A randomized double-blind study of gallium nitrate compared with etidronate for acute control of cancer-related hypercalcemia. 190 32

Clinical data of 65 patients with myeloma were analyzed to identify factors associated with hypoalbuminemia. The serum albumin level was not affected by patient age and gender, type of myeloma, and the occurrence of Bence Jones protein, lytic bone lesions, or hypercalcemia, and it was not related to changes in body weight or in liver and renal function. The albumin level, lower in patients with proteinuria, was unrelated to severity of proteinuria. Albumin level correlated significantly with the monoclonal IgG levels, hemoglobin concentration, clinical stage of disease, and estimated body tumor burden. Further analysis indicated the disease stage or the tumor burden as the dominant factor in determining albumin level. An albumin level of 29.0 g/L or less identified unequivocally advanced disease. Practically all patients with stage III myeloma had a serum albumin level of 37.0 g/L or less. Thus, hypoalbuminemia is primarily related to the extent of myeloma proliferation and is therefore of diagnostic and prognostic importance.
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PMID:Hypoalbuminemia in patients with multiple myeloma. 200 Nov 48

It has been assumed, but not documented, that hypercalcemia induces an appreciable reduction in the serum anion gap (AG) because it represents an increase in the level of unmeasured cations. To test this question, we retrospectively compared the data of 59 hypercalcemic patients with malignancy [group 1, serum Ca 13.3 +/- SE 0.3 mg/dl] with those of 108 patients whose hypercalcemia was of parathyroid origin (group 2, serum Ca 12.1 +/- 0.1 mg/dl), and those of 51 control subjects (group 3, serum Ca 9.5 +/- 0.1 mg/dl). The AG of group 2 subjects (8.7 +/- 0.3 mEq/l) was significantly lower than that of the other two groups (p less than 0.001 for both) despite their higher serum albumin and lower serum Ca in comparison to group 1. The AGs of group 1 (11.1 +/- 0.4 mEq/l) and group 3 (11.1 +/- 0.3 mEq/l) were identical. There was no statistically significant correlation between the AG and serum Ca in the hypercalcemic patients. The major finding that the association of hypercalcemia with reduced AG is seen in hyperparathyroidism, but not in malignancy-related hypercalcemia, is not explained by differences in serum albumin, renal function, or acid-base status. Overlap of values between groups limits the diagnostic usefulness of the AG in an individual patient. Nevertheless, in the absence of multiple myeloma, the finding of an AG of 5 mEq/l or less in a hypercalcemic patient may be a helpful clue suggesting that malignancy is not the etiology.
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PMID:Effect of hypercalcemia on the anion gap. 236 30

The serum concentrations of calcium, albumin and parathyroid hormone (PTH) and the plasma levels of ionized calcium were determined in 124 healthy subjects, 89 patients with primary hyperparathyroidism (HPT), 23 of whom had the syndrome of multiple endocrine neoplasia type 1 (MEN-1) and 43 patients who had hypercalcaemia of other causes than HPT (non-HPT), in most cases due to widespread malignancies. The total serum calcium was corrected for the serum albumin concentration (CaM). Healthy females over the age of 50 had higher CaM, than younger females and the women of all ages also had, higher serum PTH levels than males. For all study groups both the intra- and inter-diurnal variations were small for all the studied variables. Discriminant function and optimal discriminatory limits were calculated with the help of computer programs. A consideration of all the individuals in the discriminant analysis, revealed that measurements of CaM alone separated most HPT patients both from the healthy subjects and from the non-HPT patients. However, when only those who had borderline values (defined as CaM between 2.45 and 2.75 mmol/l) were included it turned out that measurements of ionized calcium markedly improved the delineation of mild HPT from the healthy subjects and that, in addition, PTH measurements helped to exclude those with non-HPT hypercalcaemia. The optimal discriminatory levels of serum calcium were calculated as the levels which caused the minimum loss in terms of misclassification when attention was paid to the relative importance of false positive to false negative classifications and to the prevalence of HPT. The optimal discriminatory level for serum calcium for a weighting ratio between false positive to false negative of 1:1, and a prevalence of HPT of 1%, was calculated to be 2.68 mmol/l and for a prevalence of 50% 2.56 mmol/l. In the latter situation a weighting ratio of 10:1 for false positive to false negative gave a level of 2.63 mmol/l while a weighting ratio of 1:10 corresponded to an optimal discriminatory level of 2.47 mmol/l.
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PMID:Optimal discrimination of mild hyperparathyroidism with total serum calcium, ionized calcium and parathyroid hormone measurements. 288 82

Humoral hypercalcemic syndrome associated with tumors of the female reproductive system is believed to be uncommon, and only 27 such cases have been identified prior to 1980. We describe 2 patients with humoral hypercalcemia in clear cell adenocarcinoma of the uterus, and review the literature on previously published cases. Both our patients fulfilled the criteria for humoral hypercalcemic syndrome, namely: hypercalcemia without bone metastases ranging from 12.8 to 14.1 mg/dl in the presence of normal serum parathyroid hormone levels, reduced tubular reabsorption of phosphate, and reduced serum albumin. We propose that humoral hypercalcemia is perhaps not a rare complication of uterine malignancy and, that increased awareness may result in early diagnosis of this important metabolic problem.
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PMID:Paraneoplastic hypercalcemia in endometrial carcinoma. 291 93


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