Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0031511 (pheochromocytoma)
 14,622 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A pentagastrin stimulation test using a calcitonin (CT) immunoradiometric assay was performed in 38 healthy subjects and in the following 50 patients: 25 subjects from families with at least 2 known cases of medullary thyroid carcinoma (MTC), 11 subjects from families with apparently sporadic MTC, 2 pheochromocytoma carriers, 1 primary hyperparathyroidism, 8 patients with thyroid nodules, and 3 others with various diseases. In healthy volunteers, basal CT values were always less than 10 ng/L; the response to pentagastrin was below 30 ng/L for 36, and for the remaining 2, the peaks reached 30 for 1 subject and 48 ng/L for the other. The pentagastrin-stimulated CT peak was above 30 ng/L in each of the patients presented here, and all were thyroidectomized. In screening the 25 relatives of patients with familial MTC, a CT peak level over 30 ng/L was constantly associated with C-cell disease (23 cases of MTC and 2 of C-cell hyperplasia). A response to pentagastrin above 100 ng/L was observed in 15 patients among the 23 with MTC. In 8 of the 10 patients with a peak CT level between 30-100 ng/L, pathological examination showed a MTC; the other 2 had C-cell hyperplasia and a negative linkage study analysis. In the 25 other patients in the study without familial MTC, the pentagastrin-stimulated CT level was over 100 ng/L in 11 of the 14 subjects with MTC. The abnormal CT response to pentagastrin, which has been used as a criterion for surgical treatment, is currently determined by an immunoradiometric assay. Our study confirms that subjects with a peak CT level above 100 ng/L should undergo surgery whatever the reason for the test. In the context of inherited MTC, our results suggest that for patients with a CT peak level between 30-100 ng/L, surgery may actually be postponed when their probability of being gene carriers is low. Recent progress with the characterization of specific mutations in affected individuals will make familial screening much easier in the next few months.
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PMID:Pentagastrin stimulation test and early diagnosis of medullary thyroid carcinoma using an immunoradiometric assay of calcitonin: comparison with genetic screening in hereditary medullary thyroid carcinoma. 790 11

Prospective screening programs have changed the presenting clinical features of MEN 2, the association of medullary thyroid carcinoma, pheochromocytoma, and parathyroid disease. Currently, all manifestations of MEN 2 syndrome can be diagnosed at an early stage. Gene carrier status can be identified by characterization of specific mutations. Prospective screening for early medullary thyroid carcinoma by calcitonin testing and for pheochromocytoma by several techniques routinely permits identification of early manifestations.
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PMID:Multiple endocrine neoplasia type 2. Clinical features and screening. 791 21

Medullary thyroid carcinoma (MTC) is a neoplasm derived from thyroid C-cells. It can appear under different variants; in the 20-30% of the cases, it's a familial variant. Nevertheless, the MTC appearing in MEN 2-A has a better prognosis compared to MEN 2-B. Usually, the diagnosis of MEN 2-A is done at the age of 20, and frequently (in the 50% of the cases) these patients develop, in a second time, adrenal hyperplasia and/or pheochromocytoma. The case we are talking about, concerns a patient of 49 years old, who came to our observation with a history of bilateral adrenalectomy for pheochromocytoma. What attracted our attention was the presence, in his family, of a brother, who died from pheochromocytoma, and the mother, died for a MTC. During the admit in our section, the patient has undergone a screening for the thyroid function, also if there wasn't a sign or symptom of interest of the gland. It has been possible to single out some nodular formations that, together with the high value of the calcitonin found, allowed the diagnosis of MTC. It has been very important to make diagnosis of MEN 2-A because we can introduce the patient and his family to a program of screening to precociously single out the presence of the typical signs of this pathology. In MEN 2-A a precocious diagnosis allows to sensibly improve the prognosis.
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PMID:[Medullary carcinoma of the thyroid: a case of multiple endocrine neoplasia type 2A]. 791 14

We report a case of a medullary carcinoma of the left lobe of the thyroid gland that occurred in a 57-year-old woman. The patient had undergone surgery for treatment of a bilateral-functioning pheochromocytoma when she was 39 years old. A medullary carcinoma of the thyroid gland and/or a pheochromocytoma had also been diagnosed in other family members. The tumor was composed of cells arranged in nests and large sheets separated by fibrous stroma that contained amyloid deposits. Elongated cells with thin, branched cytoplasmic projections that were strongly reminiscent of sustentacular cells usually found in paragangliomas were seen among the neoplastic cells. Immunohistochemical study showed a diffuse positive reaction for calcitonin and low-weight keratins (CAM 5.2) in neoplastic cells, whereas the sustentacular cell-like cells were positive for S100 protein. The reaction for thyroglobulin was negative. Electron microscopy disclosed large numbers of typical neurosecretory granules in the cytoplasm of tumor cells. The sustentacular cell-like cells showed elongated cytoplasmic processes and lacked neurosecretory granules. We concluded that the finding of sustentacular cell-like cells in a medullary carcinoma of the thyroid gland made its differential diagnosis from paraganglioma more problematic.
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PMID:Medullary carcinoma of the thyroid gland with sustentacular cell-like cells in a patient with multiple endocrine neoplasia, type IIA. Report of a case with ultrastructural and immunohistochemical studies. 794 93

Responses to synthetic human adrenomedullin (ADM), a novel hypotensive peptide recently discovered in human pheochromocytoma cells, and calcitonin gene-related peptide (CGRP), a structurally related peptide, were investigated in the hindquarters vascular bed of the rat. Under conditions of controlled hindquarters blood flow, intraarterial injections of ADM (0.01-0.3 nmol) and of CGRP (0.03-0.3 nmol) caused dose-related decreases in hindquarters perfusion pressure and decreases in systemic arterial pressure. Following administration of the nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME), hindquarters vasodilator and systemic depressor responses to ADM were significantly decreased, whereas L-NAME did not significantly decrease the vasodilator response to CGRP in either the hindquarters or systemic vascular beds. Following administration of the cyclooxygenase inhibitor, meclofenamate, vasodilator responses to ADM and to CGRP were not significantly decreased. When the relative vasodilator activity of the two peptides was compared on a nmol basis, responses to ADM were similar to responses with CGRP in the hindquarters vascular bed, whereas ADM was 30-100 fold less potent than CGRP in decreasing systemic arterial pressure. The present data demonstrate that ADM has significant vasodilator activity in the hindquarters vascular bed of the rat, that hindquarters vasodilator and systemic vasodepressor responses to ADM, but not to CGRP, are dependent upon the release of nitric oxide from the endothelium.
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PMID:L-NAME modulates responses to adrenomedullin in the hindquarters vascular bed of the rat. 796 46

Medullary cancer of the thyroid (MCT) in children, although uncommon, represents not only a most intriguing problem but also one that is a model of early cancer detection that results in cure. MCT in children is usually a part of the multiple endocrine neoplasia (MEN) syndrome (MCT, pheochromocytoma, and hyperparathyroidism) and is detected by screening studies. MCT arises from C cells that secrete calcitonin, with C-cell hyperplasia representing the precancerous state. Both are diagnosed by measuring calcitonin levels both basally and after stimulation with pentagastrin. Screening studies should begin shortly after birth in infants at risk for MEN IIb and by age 1 year in children at risk for MEN IIa. Application of this approach should result in near elimination of the spread of cancer in children with MCT.
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PMID:Medullary thyroid carcinoma in children. 798 34

Neuropeptides are ubiquitous in the sympathetic system and modulate transmission at the levels of the intermediolateral cell column, sympathetic ganglia, and neuroeffector junctions. Several neuropeptide-containing pathways from the hypothalamus and medulla modulate excitability of preganglionic neurons. Neuropeptides coexist with norepinephrine or acetylcholine in subpopulations of chemically coded, target-specific sympathetic ganglion neurons. Neuropeptide Y is colocalized in adrenergic vasoconstrictor neurons, whereas vasoactive intestinal polypeptide is colocalized in cholinergic sudomotor neurons. Neuropeptide expression is plastic; during development, neurons that switch from a noradrenergic to a cholinergic phenotype increase expression of vasoactive intestinal polypeptide, somatostatin, and substance P. Preganglionic inputs increase neuropeptide Y and inhibit substance P expression. Sympathetic denervation produces sprouting of sensory fibers containing substance P and calcitonin gene-related peptide in target tissues. Neuropeptides from preganglionic fibers (e.g., enkephalin) and primary afferents (e.g., substance P, vasoactive intestinal polypeptide) modulate transmission in sympathetic ganglia. Neuropeptide Y produces vasoconstriction, prejunctional inhibition of norepinephrine release, and postjunctional potentiation of norepinephrine effects. Plasma neuropeptide Y increases during intense sympathoexcitation, hypertension, and pheochromocytoma. Dystrophic neurites containing neuropeptide Y occur in human sympathetic ganglia during aging, diabetes, and dysautonomia. Sympathetic neuropeptides may thus have important clinical implications.
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PMID:Neuropeptides in the sympathetic system: presence, plasticity, modulation, and implications. 802 63

Pheochromocytoma remains a clinical challenge to diagnose and manage. In addition, the association of multiple endocrine neoplasia syndromes with pheochromocytoma require the clinician's awareness to evaluate patients with pheochromocytoma (especially when bilateral) for abnormalities in thyroidal C-cell function with serum calcitonin determinations. The authors present a case of a 42-year-old woman initially diagnosed with, and treated for, cranial artery vasculitis because she had a stroke and a history of rheumatoid arthritis and asthma. Subsequent evaluation of episodic blood pressure increases, headache, and tachycardia revealed biochemical evidence of catecholamine overproduction. Bilateral adrenal masses were found on computed tomography scanning, and the functional nature of the adrenal masses was confirmed by a meta-Iodobenzylguanidine scan. Upon further evaluation, an elevated serum calcitonin concentration was demonstrated, which increased greatly with pentagastrin stimulation. C-cell hyperplasia was demonstrated by subsequent thyroidectomy, confirming the diagnosis of multiple endocrine neoplasia 2A. The difficulty in arriving at a correct diagnosis, the subsequent management, including bilateral adrenalectomy and thyroidectomy, and newer insight into the genetic abnormalities of multiple endocrine neoplasia 2A are discussed.
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PMID:Case report: bilateral adrenal pheochromocytoma. 804 54

Multiple endocrine neoplasia (MEN) 2A associated to cutaneous lichen amyloidosis is a variant of MEN 2A recently reported in few families. We describe an additional family with this syndrome. The skin lesion is a pruritic one, located over the upper back showing, at biopsy, cutaneous amyloid. The propositus of our family was a 35-year-old woman already treated with total thyroidectomy for medullary thyroid cancer and with bilateral adrenalectomy for pheochromocytoma. The patient referred that the skin lesion was present since childhood and increased with time. Skin biopsy showed negative staining for amyloid, for calcitonin and neuron-specific enolase. The paraspinal muscles corresponding to the area of affected skin showed slight neurogenic abnormalities. Ten other members of her family were affected by MEN 2A, three of whom (all females) had the same cutaneous alteration.
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PMID:Multiple endocrine neoplasia type 2A and cutaneous lichen amyloidosis: description of a new family. 809 21

The effects of synthetic rat adrenomedullin (rAM), a novel vasorelaxant peptide originally isolated from human pheochromocytoma, on receptor binding and cAMP generation were studied in cultured rat vascular smooth muscle cells (VSMC). A binding study using [125I]rAM revealed the presence of a single class of high-affinity (Kd 1.3 x 10(-8) M) binding sites for rAM in VSMC. The apparent Ki of rat calcitonin gene-related peptide (rCGRP) was 3 x 10(-7) M. Affinity labeling of VSMC membranes with [125I]rAM revealed two distinct labeled bands with apparent molecular weights of 120 and 70 kDa, both of which were abolished by excess unlabeled rAM or rCGRP, rAM stimulated cAMP formation with an approximate EC50 of 10(-8) M, the effect of which was additive with isoproterenol, but not with rCGRP. The rAM-induced cAMP response was unaffected by propranolol, indomethacin, or quinacrine, but inhibited by a CGRP receptor antagonist, human CGRP[8-37]. These data suggest that VSMC possesses specific AM receptors functionally coupled to adenylate cyclase with which CGRP interacts.
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PMID:Specific receptors for adrenomedullin in cultured rat vascular smooth muscle cells. 813 50


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