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

We examined the effect of parathyroid hormone (PTH), administrated for 24-48 h, on acid-base homeostasis in dogs. Parathyroid extract (PTH), 15 IU/kg/day, given subcutaneously, caused metabolic alkalosis (control vs. experimental; mean +/- SEM): plasma HCO3, 21.3 +/- 0.3 vs. 24.2 +/- 0.5 mEq/l (p less than 0.001); plasma H+, 37.7 +/- 1.1 vs. 35.7 +/- 1.4 nEq/l (p less than 0.05), and net acid excretion, 48.6 +/- 2.0 vs. 65.1 +/- 4.0 mmol/day (p less than 0.01). PTH administered by continuous intravenous infusion had similar effects (control vs. experimental): plasma HCO3, 21.4 +/- 0.4 vs. 23.6 +/- 0.7 mEq/l (p less than 0.001) and net acid excretion, 54.0 +/- 3.5 vs. 68.3 +/- 5.7 mmol/day (p less than 0.05). PTH, 8 IU/kg/day, had qualitatively similar but quantitatively less profound consequences. Bicarbonaturia was not observed in any group. The effects of PTH were similar in adrenalectomized dogs maintained on hormone replacement. Indomethacin (150 mg/day) prevented the renal effects of PTH so that no increase in net acid secretion occurred. However, metabolic alkalosis still developed: control vs. experimental plasma HCO3, 21.8 +/- 0.5 vs. 23.9 +/- 0.5 mEq/l (p less than 0.001). Dichloromethanediphosphonate blunted both the renal and nonrenal effects of PTH, such that hypercalcemia, metabolic alkalosis and increased net acid excretion were quantitatively less and delayed in onset. In summary, PTH administration for 24-48 h causes metabolic alkalosis in dogs, the result of renal and nonrenal mechanisms.
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PMID:Parathyroid-hormone-induced metabolic alkalosis in dogs. 622 Feb

A case of familial primary hyperparathyroidism occurred in which persistent hypercalcemia was caused by hyperplastic parathyroid tissue left in the neck and mediastinum after initial surgery and by a hyperfunctioning parathyroid autograft in the forearm. Successful therapy required parathyroid localization and resection of tissue from the neck, mediastinum, and forearm. Parathyroid tissue should be autotransplanted at the time of initial surgery only when total parathyroidectomy is judged likely to have been achieved.
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PMID:Persistent hyperparathyroidism caused by incomplete parathyroid resection and a hyperfunctioning parathyroid autograft. 662 Apr 88

Lipoadenoma is the accepted diagnosis of a single enlarged parathyroid gland that contains large quantities of mature fat cells and focal myxoid stroma, all widely separating small parenchymal cell nests in patients with hyperparathyroidism. Here we are reporting, for the first time, on five cases of hyperparathyroidism in which all four parathyroid glands are enlarged and each gland is noted to have an admixture of fat and parenchymal cells. We will introduce the descriptive diagnosis of lipohyperplasia to name this condition and keep it in perspective with other forms of parathyroid disease. All five patients were women between the ages of 36 and 62 years who underwent neck exploration, at which time four enlarged light-tan parathyroid glands were observed. Three and one half gland resections were performed, and all patients returned to a normocalcemic state except one who had borderline serum hypercalcemia after operation. Most of the resected parathyroid glands weighed in the range of 100 to 200 mg. The largest measured gland weighed 820 mg. Parathyroid histology showed an admixture of mature fat cells with parathyroid parenchymal cells often in a 1:1 ratio. One patient who had renal failure exhibited a lower ratio of fat cells. Two patients had chronic lymphocytic thyroiditis that was severe enough to require synthetic thyroid hormone therapy. Two patients had a history of urinary tract infections. Three patients had hypertensive cardiovascular disease, and several patients had arteriosclerotic cardiovascular disease. One patient had diabetes mellitus, one had a history of pituitary adenoma, and one had polydipsia. All of these patients were first seen with parathyroid glands measuring an average of five times normal size, yet they showed the usual 50% fat/50% parenchyma pattern of normal mature parathyroid glands. This means that the enlarged glands contain a 500% increase in parathyroid tissue, justifying the diagnostic term "lipohyperplasia." This easily represents enough parathyroid tissue to generate excessive parathyroid hormone production. At this time, there is no explanation of the pathogenesis of lipohyperplasia or how it varies from other previously described forms of parathyroid hyperplasia.
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PMID:Five cases of parathyroid lipohyperplasia. 664 2

Hypercalcemia, normo- or hypophosphatemia, and increased urinary calcium clearance were observed in 8 dogs with malignant disease consisting of lymphosarcoma (n = 4), lymphogenous leukemia with bone involvement (n = 2), or carcinoma arising in the perianal region (n = 2). Parathyroid glands from these dogs had a normal or atrophic microscopic appearance. Ultrastructurally, the chief cells of the parathyroid glands had small cytoplasmic areas devoid of secretory granules and containing few organelles associated with hormonal synthesis, which is indicative of an inactive phase of the secretory cycle. In relationship to total serum calcium, serum canine immunoreactive parathyroid hormone was moderately increased in 3 dogs whose parathyroid glands had morphologic characteristics of inactivity. As a result of prolonged hypercalcemia, the thyroid glands contained prominent areas of parafollicular cell hyperplasia. The ultrastructure of a typical hyperplastic parafollicular cells was characterized by a large cytoplasmic area filled with numerous secretory granules and moderate numbers of organelles associated with hormonal synthesis. The results of this study indicate that some nonendocrine malignant neoplasms of dogs may be capable of secreting a hypercalcemia substance immunologically indistinguishable from parathyroid hormone. In the absence of neoplastic involvement of bone, the canine disease has many similarities to pseudohyperparathyroidism.
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PMID:Morphologic characteristics of the parathyroid and thyroid glands and serum immunoreactive parathyroid hormone in dogs with pseudohyperparathyroidism. 689 31

Parathyroid glands from inbred rats were transplanted to rats of the same strain. The transplantation resulted in hyperparathyroidism and persistent hypercalcaemia. These hypercalcaemic animals were compared with the hypocalcaemic donors and with untreated controls. No significant differences in serum gastrin values were found between the different groups. In all three groups, one series of animals was killed 6 weeks after the transplantation (6w series) and another after 14 weeks (14w series). Quantitative studies of the antral gastrin cells showed an increase in the number of these cells per unit volume in the 6w series in the hyperparathyroid recipient animals. The number of gastrin cells per unit segment was also higher in the recipient animals than in the parathyroidectomized and untreated groups in both the 6w and 14w series. The amount of gastrin extracted from antral mucosa did not differ between the different groups. The findings show that an experimentally induced hyperparathyroidism in the rat gives a transient increase in the number of antral gastrin cells but no changes in the antral gastrin or serum gastrin levels.
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PMID:Experimental hyperparathyroidism and its effect on serum gastrin, gastrin cells and antral gastrin in the rat. 698 92

Fourteen new cases of parathyroid cyst are presented. Two distinct groups were identified: functioning and nonfunctioning. Patients with functioning cysts presented with hypercalcemia, tended to be men and were older. Patients with nonfunctioning cysts were all women, had normocalcemia and all presented with neck masses. Ultrasonography proved useful while radionuclide thyroid scans were often misleading. In the functioning group removal of parathyroid cysts resulted in postoperative normocalcemia in all cases. In the nonfunctioning cysts thyroid lobectomy was performed in five of six instances. Parathyroid cysts usually contain clear or serous fluid and are surrounded by a well-delineated plane of dissection. We believe that preoperative aspiration of cystic neck masses and consideration of the diagnosis of parathyroid cysts may avoid needless thyroid lobectomy.
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PMID:Parathyroid cysts. 707 12

Clinical, gross, and light microscopic findings are described for 36 dogs, 33 females and three males, with adenocarcinomas arising from the apocrine glands of the anal sac. All tumors had light microscopic features of malignancy and 22 of 23 metastasized to iliac and lumbar lymph nodes. Nine dogs had disseminated metastases, but bone metastases were found in only one dog. Differentiated neoplasms formed secretory acini and tubules lined by tall columnar or cuboidal epithelium. Most neoplasms were histologically bimorphic, with glandular areas and solid nests. Parathyroid glands were atrophic. Hypercalcemia (mean = 16.1 mg/dl) was present in 20 of 22 dogs (90%) and hypophosphatemia (mean = 3.2 mg/dl) in 12 of 17 (71%). Remission of hypercalcemia by tumor ablation and recurrence of hypercalcemia with tumor regrowth suggested that the tumor produced a substance that caused hypercalcemia. This unique clinicopathologic syndrome is characterized by hypercalcemia in old, predominantly female, dogs with an adenocarcinoma arising from the apocrine glands of the anal sac.
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PMID:Hypercalcemia associated with an adenocarcinoma derived from the apocrine glands of the anal sac. 725 88

Patients with hyperparathyroidism of renal failure fall into two categories: those with hypocalcemia and those with hypercalcemia. If medical management fails and operative indications are present--bone pain or fracture, metastatic calcification, progressive hypercalcemia or uncontrolled pruritus--parathyroid exploration should be done. Total parathyroidectomy and autotransplantation is the procedure of choice when hypocalcemia is present and more than one gland (usually all) is enlarged (which is the case in most patients). Parathyroid adenomectomy is the procedure of choice where autonomy of parathyroid function is established or a single gland is enlarged and all others are small; hypercalcemia is present in these patients. In other instances of hypercalcemia associated with advanced renal disease, total parathyroidectomy and autotransplantation should be performed; that is, in patients in whom more than one gland is enlarged or irregular or in whom all glands are not identified. Continued follow-up is necessary to confirm this rationale of therapy.
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PMID:Management of hyperparathyroidism in patients with renal failure. 725 4

Parathyroid autotransplantation is a known and increasingly utilized procedure. It is indicated in patients with primary parathyroid hyperplasia, in patients with primary hypercalcemia who have normal parathyroid tissue devascularized during surgery, in patients with secondary and tertiary parathyroid hyperplasia, and in patients with total thyroidectomy when normal parathyroid tissue is accidentally or unavoidably removed or completely devascularized. No normal viable parathyroid tissue should be autotransplanted. This procedure was performed in 13 dialysis patients, 27 primary hypercalcemic patients and 77 patients with thyroidectomy. The hypercalcemic patients had autotransplantations into muscle pockets in the volar surface of the forearm, while the thyroidectomy patients had autotransplantation into the sternocleidomastoid muscles. The application of parathyroid autotransplantation is a major technical and physiologic breakthrough in the field of thyroid and parathyroid surgery. It should greatly reduce the morbidity associated with permanent hypocalcemia in this type of extensive surgery.
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PMID:Parathyroid autotransplantation in patients with parathyroid disease and total thyroidectomy. Indications in 117 cases. 728 53

The phenomenal growth in our knowledge of parathyroid hormone (PTH) physiology, chemistry and radioimmunoassay in the past 15 years has produced a significant increase in the use of the assay in the clinical laboratory evaluation of patients with disorders of calcium homeostasis. Recent experience with assays that have specificities for different regions of the amino acid sequence of the hormone and that can thus measure different portions of the total immunoreactivity in blood suggests that there may be different clinical applications for such assays. This report describes two different radioimmunoassay procedures and the clinical experience with each and suggests how each assay may be utilized in clinical evaluation of possible parathyroid dysfunction. The assay for carboxyl-terminal PTH is more useful in the differential diagnosis of the possible causes of hypercalcemia, the intact PTH assay is preferred in selective venous catheterization for preoperative localization of hyperfunctioning tissues, and both assays have usefulness in the evaluation of patients with hypocalcemia. In chronic renal failure, the considerations are more complex. In many patients, the intact PTH assay is preferred for monitoring the clinical course; however, in other patients the carboxyl-terminal PTH assay has been more useful. The best assay for each patient must be determined by initial evaluation with both assays.
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PMID:Radioimmunoassay for intact and carboxyl-terminal parathyroid hormone: clinical interpretation and diagnostic significance. 736 99


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