parathyroid

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parathyroid

 [par″ah-thi´roid]
1. near the thyroid gland.
3. a preparation containing parathyroid hormone from animal parathyroid glands; used for diagnosis and treatment of hypoparathyroidism.
parathyroid glands four small endocrine bodies in the region of the thyroid gland; they contain two types of cells: chief cells and oxyphils. Chief cells are the major source of parathyroid hormone (PTH), the secretion of which is dependent on the serum calcium level. Through a closed-loop feedback mechanism a low serum calcium level stimulates secretion of PTH; conversely, a high serum calcium level inhibits its secretion. The essential role of PTH is maintenance of a normal serum calcium level in association with vitamin D and calcitonin. It does this by exerting its effects on bone, kidney, and gastrointestinal tract. In bone, it enhances bone resorption by increasing digestion of the bone matrix by osteoclasts, which produces calcium that gets released into the bloodstream. In the kidney, PTH increases the excretion of phosphate and the reabsorption of filtered calcium. In the intestine, it increases intestinal absorption of calcium. The parathyroid glands may be subject to either hyperparathyroidism or hypoparathyroidism.

par·a·thy·roid

(par'ă-thī'royd),
1. Adjacent to the thyroid gland.
2. Synonym(s): parathyroid gland

parathyroid

(păr′ə-thī′roid)
adj.
1. Of, relating to, or obtained from the parathyroid glands: a parathyroid extract.
2. Adjacent to the thyroid gland.
n.
1. Any of the parathyroid glands.
2. A parathyroid hormone.

parathyroid

adjective Referring to the parathyroid gland.

noun Parathyroid gland (see there); glandulae parathyroideae [NA6].

par·a·thy·roid

(par'ă-thī'royd)
1. Adjacent to the thyroid gland.
2. Synonym(s): parathyroid gland.

parathyroid

an endocrine gland of higher vertebrates that is situated in or near the thyroid gland and controls the calcium level of the blood. When too little [Ca+] is present in the blood, parathormone is secreted which:
  1. (a) reduces the OSTEOBLAST activity and thus the amount of bone-matrix formation,
  2. (b) increases [Ca+] uptake from the gut into the blood stream, and
  3. (c) acts on the kidney tubules, decreasing calcium and phosphate excretion. Undersecretion of parathormone results in a fall of blood calcium and causes TETANY.
References in periodicals archive ?
(iv) highlights the clinical challenge in distinguishing benign and malignant parathyroid tumors due to the lack of definitive preoperative diagnostic tools
This is the first report, to our knowledge, of discontinuation of anticoagulants causing autoinfarction of a large parathyroid tumor and resulting hungry bone syndrome.
Correlation between clinical and histological findings in parathyroid tumors suspicious for carcinoma.
(20) In our study, HBME-1 was applied to all parathyroid tumors to assess the diagnostic utility in the differential diagnosis of parathyroid and thyroid neoplasms that sometimes could be confusing because of the very close adjacency of thyroid and parathyroid tissues.
We aimed to improve the differential diagnostic markers in parathyroid tumors by evaluating the use of parafibromin, Ki-67, galectin-3, and HBME-1.
(20) to determine that the endothelial component in MEN1 parathyroid tissue accounted for the majority of the stromal component of the excised parathyroid tumors. They used a 30-gauge needle under a light microscope to select tumor cells and to minimize the amount of contamination by stromal tissue.
There is nearly a 4-fold increase in parathyroid tumors among people who were exposed to the atomic bomb in Hiroshima.
(26) Franklin et al (24) reported increased CDK activity in the G1 phase of p18-depleted and p27-depleted mice, which develop parathyroid tumors and hyperplasia.
Expression of cell-cycle regulatory proteins has been researched in parathyroid tumors; however, since parathyroid neoplasms may contain multiple molecular changes, one should investigate various genes in the same tissue, as shown by Stojadinovic et al (33) in their detailed study of the components of the p53 pathway.
Monoclonality of parathyroid tumors in chronic renal failure and not in primary parathyroid hyperplasia.
Proliferative activity in parathyroid tumors as detected by Ki-67 immunostaining.
The role of prognostic markers (MiB-1, RB, and bcl-2) in the diagnosis of parathyroid tumors. Mod Pathol.