Biomaterial Database

Medullary thyroid carcinoma and calcitonin. 1985

K Emmertsen

Medullary carcinoma of the thyroid (MCT) develops from the thyroid C-cells. Thyroid C-cells and MCTs secrete calcitonin (CT), a 32 amino acid polypeptide hormone. The author has described a sensitive direct sequential radioimmunoassay of CT in human serum. The vast majority of healthy subjects had detectable values of serum immunoreactive calcitonin (iCT) and elevated levels were found in patients with MCT. Besides CT, several higher molecular weight substances contribute to CT-immunoreactivity. These substances may represent metabolic products in the processing of a glycosylated procalcitonin to CT. Calcium, several gastrointestinal hormones and ethanol increases CT secretion from normal and neoplastic C-cells, but the physiological regulation of CT secretion has not been firmly established. The author has shown that the levels of serum iCT vary little during day and nighttime. CT acutely reduces bone resorption and, in pharmacological doses, increases urinary electrolyte excretions. A lowering in serum calcium, magnesium and phosphorus levels result but the effect is pronounced only in disease states with a high bone turnover. The physiological role for CT may be preservation of the skeleton at times of increased need for calcium. A causal relationship between postmenopausal osteoporosis and CT deficiency has been proposed. The author has described increased serum 1,25-dihydroxyvitamin D levels and increased trabecular bone remodeling in patients with MCT and normalization of these parameters following surgical cure for MCT. These results were interpreted to indicate that chronic endogenous CT excess directly enhances the renal production of 1,25-dihydroxyvitamin D which, acting synergistically with parathyroid hormone, increases trabecular bone remodeling. Elevated serum iCT is almost invariably found in patients with clinically manifest MCT as well as in several patients with clinically occult MCT. An exaggerated increase in serum iCT levels after provocative testing with pentagastrin and/or calcium can disclose early C-cell neoplasia. Elevated serum iCT may be encountered in non-C-cell neoplasias and in renal insufficiency. Compared to MCT, circulating iCT may show a different immunochemical profile and the response to provocative testing is blunted in these conditions. MCT occurs in a sporadic variety, and in a familial variety as part of two related multiple endocrine neoplasia (MEN) syndromes. MEN IIa consists of MCT and often phaeochromocytomas and/or hyperparathyroidism and invariably exhibits an autosomal dominant mode of inheritance but a variable age of expression.(ABSTRACT TRUNCATED AT 400 WORDS)

UI	MeSH Term	Description	Entries
D006961	Hyperparathyroidism	A condition of abnormally elevated output of PARATHYROID HORMONE (or PTH) triggering responses that increase blood CALCIUM. It is characterized by HYPERCALCEMIA and BONE RESORPTION, eventually leading to bone diseases. PRIMARY HYPERPARATHYROIDISM is caused by parathyroid HYPERPLASIA or PARATHYROID NEOPLASMS. SECONDARY HYPERPARATHYROIDISM is increased PTH secretion in response to HYPOCALCEMIA, usually caused by chronic KIDNEY DISEASES.
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D009092	Mucous Membrane	An EPITHELIUM with MUCUS-secreting cells, such as GOBLET CELLS. It forms the lining of many body cavities, such as the DIGESTIVE TRACT, the RESPIRATORY TRACT, and the reproductive tract. Mucosa, rich in blood and lymph vessels, comprises an inner epithelium, a middle layer (lamina propria) of loose CONNECTIVE TISSUE, and an outer layer (muscularis mucosae) of SMOOTH MUSCLE CELLS that separates the mucosa from submucosa.	Lamina Propria,Mucosa,Mucosal Tissue,Muscularis Mucosae,Mucous Membranes,Membrane, Mucous,Membranes, Mucous,Mucosae, Muscularis,Mucosal Tissues,Propria, Lamina,Tissue, Mucosal,Tissues, Mucosal
D009377	Multiple Endocrine Neoplasia	A group of autosomal dominant diseases characterized by the combined occurrence of tumors involving two or more ENDOCRINE GLANDS that secrete PEPTIDE HORMONES or AMINES. These neoplasias are often benign but can be malignant. They are classified by the endocrine glands involved and the degree of aggressiveness. The two major forms are MEN1 and MEN2 with gene mutations on CHROMOSOME 11 and CHROMOSOME 10, respectively.	Adenomatosis, Familial Endocrine,Endocrine Neoplasia, Multiple,Multiple Endocrine Neoplasia Syndrome,Neoplasia, Multiple Endocrine,Neoplasms, Multiple Endocrine,Adenomatosis, Multiple Endocrine,Familial Endocrine Adenomatosis,Multiple Endocrine Adenomatosis,Multiple Endocrine Adenopathy,Multiple Endocrine Neoplasia Syndromes,Multiple Endocrine Neoplasms,Adenomatoses, Familial Endocrine,Adenomatoses, Multiple Endocrine,Adenopathies, Multiple Endocrine,Adenopathy, Multiple Endocrine,Endocrine Adenomatoses, Familial,Endocrine Adenomatoses, Multiple,Endocrine Adenomatosis, Familial,Endocrine Adenomatosis, Multiple,Endocrine Adenopathies, Multiple,Endocrine Adenopathy, Multiple,Endocrine Neoplasms, Multiple,Familial Endocrine Adenomatoses,Multiple Endocrine Adenomatoses,Multiple Endocrine Adenopathies
D009463	Neuroma	A tumor made up of nerve cells and nerve fibers. (Dorland, 27th ed)	Neuromas
D010257	Paraneoplastic Syndromes	In patients with neoplastic diseases a wide variety of clinical pictures which are indirect and usually remote effects produced by tumor cell metabolites or other products.	Paraneoplastic Syndrome,Syndrome, Paraneoplastic,Syndromes, Paraneoplastic
D010673	Pheochromocytoma	A usually benign, well-encapsulated, lobular, vascular tumor of chromaffin tissue of the ADRENAL MEDULLA or sympathetic paraganglia. The cardinal symptom, reflecting the increased secretion of EPINEPHRINE and NOREPINEPHRINE, is HYPERTENSION, which may be persistent or intermittent. During severe attacks, there may be HEADACHE; SWEATING, palpitation, apprehension, TREMOR; PALLOR or FLUSHING of the face, NAUSEA and VOMITING, pain in the CHEST and ABDOMEN, and paresthesias of the extremities. The incidence of malignancy is as low as 5% but the pathologic distinction between benign and malignant pheochromocytomas is not clear. (Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1298)	Pheochromocytoma, Extra-Adrenal,Extra-Adrenal Pheochromocytoma,Extra-Adrenal Pheochromocytomas,Pheochromocytoma, Extra Adrenal,Pheochromocytomas,Pheochromocytomas, Extra-Adrenal
D011379	Prognosis	A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.	Prognostic Factor,Prognostic Factors,Factor, Prognostic,Factors, Prognostic,Prognoses
D011498	Protein Precursors		Precursors, Protein
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays