PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “PARATHYROID GLAND”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1988

Localization of parathyroid glands.

Parathyroid localization tests are helpful for all patients with primary hyperparathyroidism before parathyroid exploration, and they are essential for patients who have had previous parathyroid or thyroid operations. The selection of specific localization tests depends on whether the patient is undergoing an initial or a reoperative procedure, as well as on the availability of the specialized equipment and expertise of the physicians and technicians performing and interpreting these studies.

Diagnostic Imaging↗
PubMed1984

[The thyroid gland, the parathyroid gland and the skin].

Hormones of the thyroid gland (thyroxine, tri-iodothyronine) control the metabolism of cells and tissue of the body, while parathormone and calcitonine are balancing the intra- and extracellular levels of calcium and phosphorus by governing some metabolic functions of bones, kidney and small intestine. Growth, maturation and metabolic homeostasis of the organism depend, among other intrinsic factors, on a normal production and secretory rate of both thyroidal and parathyroidal hormones. Clinical conditions of hyperthyroidism induce 1. increased metabolic turnover of the body with transcutaneous heat loss, 2. disordered growth of hairs and nails, 3. hyperpigmentation of skin, 4. pruritus with or without urticaria. Pretibial (usually symmetrical) myxedema may be associated with conditions of either hyper- or hypothyroidism (e.g., Hashimoto's thyroiditis); if combined with bilateral exophthalmus and acropachyderma of fingers and toes, it is called Diamond syndrome, or E.M.O. syndrome. In hypothyroidism, the skin feels chilly and dry, looks pale, and may present follicular keratoses with or without secondary eczema. The hair appears dull and sparse due to disordered anagen phase. Skin wounds heal with delay. Diffuse myxedema originates in the papillary and periadnexal connective tissue and eventually extends to the dermis as a whole. Clinical conditions of hyperparathyroidism rarely cause secondary calcification of the skin; they may induce severe pruritus, particularly in secondary hyperparathyroidism due to renal failure. Impetigo herpetiformis or generalized pustular psoriasis, resp., may be set off by excessive surgical removal of the goiter. Congenital maldevelopment of both thymus and parathyroid gland leads to cellular immune deficiency with secondary chronic muco-cutaneous candidosis.

Calcium↗
PubMed1976

Use of 131I-toluidine blue in radionuclide imaging of enlarged parathyroid glands.

Parathyroid scintigraphy with 131I-labelled toluidine blue was performed in 40 patients, 30 of whom were operated for suspected hyperparathyroidism. Hyperplastic glands or adenomas could be localized by scintigraphy in 18 of 27 patients who proved to have hyperparathyroidism. The correlation between scintigraphy and operative finding was always correct when the parathyroids weighed more than 2 g. Scintigraphy was correctly negative in one, falsely negative in 6, and falsely positive in 5 of the operated patients. In a group of 10 unoperated patients, scintigraphy was positive in one of the 3 patients with suspected hyperparathyroidism, but negative in the others. Although 131I-toluidine blue is not ideal as a scintigraphic agent for the parathyroids, we are of the opinion that it represents an improvement compared with 75Se-selenomethionine.

Evaluation Studies as Topic↗
PubMedDate not supplied

The carcinoma of parathyroid gland.

Parathyroid carcinoma constitutes less than 1% of primary hyperparathyroidism. The exact etiology is not known. Prior radiation to neck, chronic renal failure and genetic factors are thought to play a role. The male to female ratio is one. Parathyroid carcinomas are slow growing, have a tendency to recur locally and metastasize late. 95% of parathyroid carcinomas are functioning. The major distinguishing features of malignant hyperparathyroidism are presence of a palpable mass in the neck and features of severe hypercalcemia. By far the most important test to diagnose primary hyperparathyroidism is serum level of Immunoreactive PTH. The diagnosis of primary hyperparathyroidism is essentially clinical and biochemical. Biopsy is not necessary before definitive surgery. CT scan appears to be the best investigation for detecting the primary tumor, its local extent and metastases. Most of the symptoms are attributable to hypercalcemia, which needs to be treated aggressively. Early surgery with 'en bloc' resection of the tumor is the only potentially curative treatment. Parathyroid carcinoma is traditionally said to be resistant to radiotherapy. Various chemotherapeutic agents have been used with partial anecdotal responses. The 5-year survival is about 50% and 10-year survival varies from 13-49%.

Carcinoma↗
PubMed1998

[B-mode ultrasound and modern Doppler ultrasound methods in diseases of the thyroid gland and parathyroid glands].

Color-coded duplex sonography is the main innovation in diagnostic ultrasound in recent years. It allows quantification of tissue vascularity and appreciation of vascular morphology. Due to the unique thyroid hypervascularity in Graves' disease this diagnosis can be made with color Doppler sonography alone. The decrease of vascularity during the course of disease is a relevant parameter throughout the follow-up. Hypervascularity is also observed within areas of inflammatory infiltration in thyroiditis, but the level is lower than in Graves' disease. Sonographic differentiation of benign from malignant thyroid nodules is not possible yet. Color-coded duplex sonography is not useful in the initial detection of parathyroid masses, but may be helpful in distinguishing parathyroid lesions from other cervical masses.

Diagnosis, Differential↗
PubMed1990

The crab-eating frog Rana cancrivora: serum mineral concentrations and histology of the ultimobranchial gland and the parathyroid gland.

In the crab-eating frog Rana cancrivora, taken from a full-strength seawater pond, the in situ levels of serum Na, Cl, K, Ca, Mg, Pi, urea, and osmolarity were examined. The levels were higher than those usually reported for freshwater anurans. However, values for the monovalent salts, urea, and osmolarity were lower than those reported by Gordon et al. (1961, J. Exp. Biol. 38, 659-678) following immersion of this species in 80% seawater for 7 days. The histological features of the ultimobranchial gland and parathyroid gland were coincident with those known in usual freshwater frogs, in spite of the peculiarity of the habitat of this species. The ultimobranchial gland was composed of a single follicle or multiple follicles. In most parenchymal cells, immunoreactive calcitonin was detected using the PAP method with anti-salmon calcitonin antiserum. In the parathyroid gland, cells in the central part of the gland were smaller than those in the peripheral part.

Animals↗
PubMed1977

The effect of 1,25-dihydroxycholecalciferol on the parathyroid hormone secretion of porcine parathyroid glands and human parathyroid adenomas in vitro.

The effect of 1,25-dihydroxycholecalciferol (1,25-(OH)2-D3) on parathyroid hormone secretion by porcine parathyroid glands and human parathyroid adenoma tissue was investigated by in vitro incubation. The addition of 100 nmoles 1,25-(OH)2-D3 to the medium inhibited significantly the release of immunoreactive parathyroid hormone by 63--65%. This suppression was reversible when 1,25-(OH)2-D3 was removed again. The inhibition of parathyroid hormone release observed in human parathyroid adenoma tissue was similar to that in normal porcine parathyroid glands. This indicates that adenoma tissue is sensitive to regulatory influences. As well as calcium, 1,25-(OH)2-D3 may act as another feedback inhibitor of parathyroid hormone secretion.

Adenoma↗
PubMed1983

The use of ultrasound in the localisation of parathyroid glands in parathyroid disorders.

Eleven patients with clinical and biochemical evidence of primary hyperparathyroidism were studied with ultrasonography. In nine patients who were treated surgically, four had predictive ultrasound scans (44% consistency). There was no correlation between the transverse diameters of the glands, as measured from the scans, and either the pathologist's measurements or the mean protein-corrected serum calcium and parathormone (PTH) levels. The investigation failed to identify the only patient with parathyroid hyperplasia. The difficulties encountered and the reasons for the high number of both false positive and false negative scans are discussed. Five patients with parathyroid disorders associated with hyperplasia were also studied and in four patients the enlarged glands were identified. A variation in size between the glands in each patient was noted. No correlation between the total of the transverse diameters and either the protein-corrected serum calcium or PTH levels was found. Reduction in size of the glands in one patient occurred over a 12-month period on treatment and a role for ultrasonography in the follow-up of patients with secondary hyperparathyroidism is discussed.

Adenoma↗
PubMed2005

Radionuclide imaging of the parathyroid glands.

The parathyroid glands, which usually are situated behind the thyroid gland, secrete parathyroid hormone, or PTH, which helps maintain calcium homeostasis. Primary hyperparathyroidism results from excess parathyroid hormone secretion. In secondary hyperparathyroidism, the normal PTH effect on bone calcium release is lost. Serum PTH rises, causing generalized hyperplasia. In tertiary hyperparathyroidism, a complication of secondary hyperparathyroidism, normal feedback mechanisms governing PTH secretion are lost, parathyroid gland sensitivity to PTH decreases, and the threshold for inhibiting PTH secretion increases. 99mTc sestamibi, or MIBI, the current radionuclide study of choice for preoperative parathyroid localization, can be performed in various ways. The "single-isotope, double-phase technique" is based on the fact that MIBI washes out more rapidly from the thyroid than from abnormal parathyroid tissue. However, not all parathyroid lesions retain MIBI and not all thyroid tissue washes out quickly, and subtraction imaging is helpful. Many MIBI avid thyroid lesions also accumulate pertechnetate and iodine, and subtraction reduces false positives. Single-photon emission computed tomography provides information for localizing parathyroid lesions, differentiating thyroid from parathyroid lesions, and detecting and localizing ectopic parathyroid lesions. The most frequent cause of false-positive MIBI results is the solid thyroid nodule. Other causes include thyroid carcinoma, lymphoma, and lymphadenopathy. False-negative results occur because of several factors. Lesion size is important. Cellular function also may be important. Parathyroid tissue that expresses P-glycoprotein does not accumulate MIBI. Parathyroid adenomas that express either P-glycoprotein or the multidrug resistance related protein MRP are less likely to accumulate MIBI. MIBI scintigraphy is less sensitive for detecting hyperplastic parathyroid glands. In secondary hyperparathyroidism, MIBI uptake is more closely related to cell cycle than to gland size. Mitochondria-rich oxyphil cells presumably account for MIBI uptake in parathyroid lesions. Fewer oxyphil cells, and hence fewer mitochondria, may explain both lower uptake and rapid washout of MIBI from some lesions. MIBI is also less sensitive for detecting multigland disease than solitary gland disease.

Humans↗
PubMed2004

[Ambulatory and brief inpatient thyroid gland and parathyroid gland surgery].

Outpatient or short-stay thyroid and parathyroid surgery is still uncommon in Germany. Although a substantial number of these operations are performed with low morbidity, nearly zero mortality, and short operation time, some potentially lethal complications, especially postoperative hemorrhage, are strong arguments against liberal shortening of hospital stay. Symptomatic hematomas after thyroid and parathyroid surgery are observed in about 1-2% of cases. They frequently occur during the first 8 h after operation (40%). However, two thirds of these major complications occur later, about 20% of them more than 24 h postoperatively. Therefore, an outpatient procedure cannot be generally recommended. Short-stay (<23 h, overnight) thyroid and parathyroid surgery may be attractive, but this concept requires clear release-criteria and professional outpatient structures. Compared to general anesthesia, local and regional anesthesia did not emerge as helpful to shorten hospital stay. Also, prophylactic calcium supplementation is not recommended to enhance early hospital discharge after bilateral thyroid or parathyroid surgery.

Ambulatory Surgical Procedures↗
PubMed1989

Tumors of the parathyroid gland and circulating parathyroid hormone-related protein associated with persistent hypercalcemia.

Neoplasms of the parathyroid glands are uncommon in all species of laboratory and domestic animals, but occur in low incidence in rats, Syrian hamsters, and dogs and rarely in mice. Proliferative lesions of the parathyroid gland include hyperplasia (diffuse and focal), adenomas, and carcinomas. The tumors may be functional or nonfunctional. Trophic atrophy of remaining parathyroid tissue is present around functional tumors. Humoral hypercalcemia of malignancy (HHM) is a syndrome that occurs in human and animal patients with certain malignant neoplasms and is characterized by hypercalcemia, hypophosphatemia, and increased osteoclastic bone resorption. The syndrome is thought to be due to the release of parathyroid hormone (PTH)-like factors by the tumor cells which bind to PTH receptors in bone and kidney and result in the clinical manifestations of HHM. Parathyroid hormone-related protein (PTHrP) is a newly purified and sequenced protein which originated from human tumors associated with HHM. PTHrP has been shown to stimulate in vitro and in vivo effects similar to PTH-like proteins isolated from tumors associated with HHM. Well characterized animal models of HHM include a rat Leydig cell tumor line (Rice-500), the rat Walker mammary carcinosarcoma, and the canine apocrine adenocarcinoma. All 3 models have been found to contain 3 biologic activities which are thought to be important in the pathogenesis of HHM, viz., in vitro bone resorbing activity, adenylate cyclase-stimulating activity of bone and kidney cells, and transforming growth factor activity. The first 2 activities are due to PTH-like proteins which are able to compete for binding to the PTH receptor. The complete spectrum of functional disturbances in patients with HHM may be the result of the combined effects of a PTH-like protein (i.e., PTHrP) and transforming growth factors.

Animals↗
PubMed1992

An in vitro study on the effects of melatonin on the ultrastructure of the hamster parathyroid gland.

Isolated parathyroid glands from adult female golden hamsters were incubated on a black Millipore filter in an incubation vessel containing Ham's F-12 medium, with or without melatonin at final concentration of 10(-5) M for 1 hour. In the parathyroid glands used for in vitro treatments with melatonin, the Golgi complexes associated with a few prosecretory granules and cisternae of the rough endoplasmic reticulum showed a significant decrease, and lipid droplets and lysosomes appeared to be increased compared with those of the control parathyroid glands. These changes are considered to be induced by suppression of the synthesis of parathyroid hormone in parathyroid glands incubated in a vessel containing medium with melatonin.

Animals↗
PubMed1986

Paraphysectomy-induced stimulation of parathyroid glands in mature frogs (Rana catesbeiana): evidence for telencephalic regulation of parathyroid gland function.

The relationship of the paraphyseal-choroid plexus complex to parathyroid gland function was investigated in adult frogs. Light microscopy and morphometric analysis indicated that total parathyroid gland volume, cell volume and vascular volume doubled by 7-28 days after surgical removal of the paraphyseal-choroid plexus complex (paraphysectomy). This increase correlated with the appearance of large Golgi-associated vesicles, an increase in the apparent number of cytoplasmic dense-core granules, and PTH within the parenchymal cells as monitored by immunofluorescence. Twelve months after paraphysectomy, parathyroid glands became cystic with a central fluid-filled cavity surrounded by a stratified cuboidal cell layer. The parenchymal cells of cystic glands contained numerous cytoplasmic dense-core granules and were also positive for PTH. Radioimmunoassay of cystic parathyroid fluid indicated a PTH concentration of 2 micrograms/microliter; however, analysis by SDS-PAGE indicated a wide range of proteins in cystic fluid. The results of this study indicate that paraphysectomy induces stimulation of the parathyroid glands and suggest a role for the paraphyseal-choroid plexus complex in the regulation of amphibian parathyroid gland function.

Animals↗
PubMed2000

Parvalbumin is expressed in normal and pathological human parathyroid glands.

The parathyroid glands are of major importance in calcium homeostasis. Small changes in the plasma calcium (Ca2+) concentration induce rapid changes in parathyroid hormone (PTH) secretion to maintain the extracellular Ca2+ levels within the physiological range. Extracellular Ca2+ concentration is continuously measured by a G-protein-coupled Ca2+-sensing receptor, which influences the expression and secretion of PTH. The mechanism of signal transduction from receptor sensing to PTH secretion is not well understood, but changes in PTH secretion are tightly linked to changes in the cytosolic Ca2+ concentration. Using immunohistochemistry and Western blot analysis, we detected the EF Ca2+ binding protein parvalbumin (PV) in normal and in hyperplastic and adenomatous human parathyroid glands. The strongest PV signal was present in chief cells and water clear cells, whereas in oxyphilic cells only a weak signal was observed. Immunohistochemistry and in situ hybridization of the PTH indicated a co-localization of PV and PTH in the same cell types. Because changes in the cytosolic Ca2+ concentration are believed to influence the process of PTH secretion, a possible role of PV as a modulator of this Ca2+ signaling is envisaged.

Adenoma↗