Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Twenty-four hyperplastic parathyroid glands from 11 patients with multiple endocrine neoplasia type I (MEN-I), and 36 hyperplastic parathyroid glands in 15 patients with sporadic primary hyperparathyroidism, ie, not associated with MEN, were analyzed for DNA by flow cytometry. Sixteen of 24 hyperplastic parathyroid glands from patients with MEN-I were DNA diploid, and eight were DNA aneuploid. Thirty-three of 36 hyperplastic parathyroid glands from patients without MEN were DNA diploid, and only three were DNA aneuploid. The mean percentage of 4c level (a measure of the G2M phase of the cell cycle) of DNA diploid hyperplastic parathyroid glands taken from patients with MEN-I was 8.1% +/- 4.5%, which is significantly higher than the 3.5% +/- 3.4% for those taken from patients without MEN. Our results show that there is a difference in nuclear DNA content between hyperplastic parathyroid glands in patients with MEN-I and those in patients without MEN.
 ...
PMID:Nuclear DNA analysis of hyperplastic parathyroid glands in multiple endocrine neoplasia type I. 136 89

Hypercalcemia was corrected in 62 (90%) of 69 patients after re-operation for primary hyperparathyroidism during a mean follow-up of 6.3 years. Failed primary exploration was mainly due to inadequate visualization of the pathological parathyroid glands, often in association with misleading or absent peroperative histology. Other causes included seeding of parathyroid adenoma tissue, truly recurrent adenomas, and recurrent hyperplasia, especially in patients with multiple endocrine neoplasia type 1. A considerable number of parathyroid glands missed at the primary operations were subsequently found in essentially normal positions. Ectopic superior glands were most frequently positioned para-esophageally or retro-esophageally, while abnormally placed inferior glands were generally situated within or close to the thymus. Glands in 3 patients were dissected from around the large vessels in the mediastinum. Concomitant thyroid procedures during the primary operation yielded few abnormal parathyroids and made the re-exploration considerably more difficult. We suggest a semilateral approach and caudal identification of the recurrent laryngeal nerve to reduce the hazards of difficult parathyroid re-operations. Mediastinal exploration may require total removal of the thymus and careful dissection of the middle mediastinum.
 ...
PMID:Causes of failed primary exploration and technical aspects of re-operation in primary hyperparathyroidism. 141 26

We report a family with primary hyperparathyroidism in four patients in two generations with apparent autosomal dominant transmission. A fifth member was probably affected. Two cases had definite parathyroid carcinoma (PC), and two had parathyroid adenoma with atypical features that could represent an early stage of cancer. In each of our patients, one parathyroid gland was abnormal. Five other parathyroid glands (in two patients) were normal in histology and size. There was no evidence of neoplasia in other tissues. Constitutional karyotypes were normal in all four patients. We identified three chromosomal abnormalities (a reciprocal translocation between chromosomes 3 and 4, trisomy 7, and a pericentric inversion in chromosome 9) in cultured PC tissue from one patient. These chromosomal changes are of unclear significance. Analyses on tumor DNA from one case of PC and one of atypical adenoma showed no evidence of ras gene mutations, PTH gene rearrangement, or allelic loss from chromosome 11q13 (locus of the gene for multiple endocrine neoplasia type 1). This family shows susceptibility to cancer without antecedent hyperplasia in all parathyroids. It could help identify a novel tumor susceptibility gene.
 ...
PMID:Studies in a kindred with parathyroid carcinoma. 163 36

A 63-year-old female presented with the extremely rare occurrence of an aldosterone-secreting adrenocortical adenoma as part of the syndrome of multiple endocrine neoplasia type 1 (MEN1). Only two other MEN1 patients were reported in the literature with hyperaldosteronism. The patient's MEN1 syndrome consisted of the association of primary hyperparathyroidism due to parathyroid adenoma, a prolactinoma, and a toxic multinodular goiter. Elevated basal and meal-stimulated serum PP levels without demonstrable pancreatic tumor were also found. Genetic analysis of the aldosterone-secreting adenoma with DNA markers localized on chromosome 11 showed loss of heterozygosity in tumor DNA. Since the MEN1 syndrome is caused by loss of the tumor suppressor gene on chromosome 11 in the 11q13 region, it is probable that the same mechanism is associated with the formation of the adrenocortical adenoma.
 ...
PMID:Aldosterone-secreting adrenal adenoma as part of multiple endocrine neoplasia type 1 (MEN1): loss of heterozygosity for polymorphic chromosome 11 deoxyribonucleic acid markers, including the MEN1 locus. 163 57

A total of 80 individuals in 4 kindreds with multiple endocrine neoplasia type 1 (MEN 1) have been subjected to repeated biochemical screening during a 10-yr period with the principal aim being to analyze characteristics of the developing pancreatic lesion. Age at presentation of the MEN 1 trait averaged 18 yr in 7 previously unaffected individuals, and this effect of the screening procedure represented a lowering by almost 2 decades. Pancreatic endocrine involvement was recognized at a mean age of 25 yr and constituted the presenting lesion in a majority of the patients. A standardized meal test and basal values of serum pancreatic polypeptide, insulin, proinsulin, and gastrin were the most efficient markers for the pancreatic lesion and preceded signs of pancreatic tumors upon radiological examinations by a mean of 3.5 yr. A 75% penetrance of the islet cell disease and 90% for primary hyperparathyroidism within the affected individuals equalled the prevalences reported in autopsy studies. Two of the kindreds showed signs of intrafamilial homogeneity with respect to the profile of peptide excess (P less than 0.05) and considerable discrepancy in the malignant potential of the pancreatic lesions. The results of early detection and surgical intervention of the pancreatic tumors in MEN 1 suggested an impact on morbidity, while any effect on the mortality of these individuals remains to be clarified.
 ...
PMID:Multiple endocrine neoplasia type 1: a 10-year prospective screening study in four kindreds. 167 62

Gene probe analysis of the MEN 2A locus on chromosome 10 has been undertaken using the markers TB10.163, RBP 3 and TB14.34 in a large kindred with familial medullary thyroid carcinomas, with or without phaeochromocytomas or primary hyperparathyroidism. A maximum LOD score of 2.97 gave strong evidence of close linkage with zero recombination. For 12 members of the family so far not known to be affected by any form of the disease the estimated risk of carrying the gene has been considerably decreased in all but one, whose risk has been greatly increased.
 ...
PMID:Gene probe analysis in an informative family with multiple endocrine neoplasia syndrome type 2A (MEN 2A). Improvement in carrier risk estimation. 168 70

Primary hyperparathyroidism is caused by defects in the parathyroid gland. Investigations have implicated three interesting genes whose mutation can cause primary hyperparathyroidism. Familial hypocalciuric hypercalcemia is believed to be an atypical form of primary hyperparathyroidism with an inherited defect in calcium recognition expressed not only in all parathyroid chief cells (thus a polyclonal defect) but in some renal tubular cells as well. In typical primary hyperparathyroidism a monoclonal parathyroid tumor is usually the central cause. Either of two apparently different genes on the long arm of chromosome 11 has been implicated in development of a parathyroid tumor clone. One gene (D11S287) was shown to have undergone a rearrangement with the parathyroid hormone gene on the short arm of the same chromosome (pericentromeric inversion) in a small fraction of tumors; the D11S287 locus may encode a growth stimulator. Another gene, the locus for familial multiple endocrine neoplasia type 1 (FEMEN1), is likely to encode a growth inhibitor. Inactivation of this gene or another nearby gene by somatic mutation has been indirectly implicated in one-quarter of sporadic parathyroid adenomas and in more than half of parathyroid tumors in FMEN1. In conclusion, studies have suggested three different mechanisms for parathyroid gland dysfunction in primary hyperparathyroidism: (1) a defect in calcium recognition, (2) a monoclonal tumor from overexpression of a growth stimulator, or (3) a monoclonal tumor from inactivation of a growth inhibitor.
 ...
PMID:Etiologies of parathyroid gland dysfunction in primary hyperparathyroidism. 168 85

Multiple gland parathyroid disease is the pathological finding in primary hyperparathyroidism (HPT) in about 10% to 20% of all patients and in approximately a third of all patients with persistent or recurrent disease. The variability of multiple gland disease spans from 2 adenomas to diffuse hyperplasia in patients with multiple endocrine neoplasia type 1. This variability calls into question the proposed common pathophysiologic background in all of these cases. As primary treatment of multiple gland primary HPT, subtotal parathyroidectomy and thymectomy or total parathyroidectomy and heterotopic autotransplantation including thymectomy can be equally advocated. Recurrent hyperparathyroidism frequently occurs in cases of diffuse parathyroid hyperplasia. This must be considered especially in patient follow up and before each surgical procedure. Thus, a defined but adaptable therapeutic regimen might prevent permanent hypoparathyroidism and persistent hyperparathyroidism.
 ...
PMID:Management of primary hyperparathyroidism caused by multiple gland disease. 168 44

The differential diagnosis of hypercalcemia has expanded to over 25 separate disease states, with primary hyperparathyroidism and malignancy accounting for 80-90% of all hypercalcemic patients. Primary hyperparathyroidism comprises the majority of hypercalcemic patients among the ambulatory population, but malignancy accounts for up to 65% of such patients in the hospital. Factors favoring primary hyperparathyroidism include a family history of hyperparathyroidism or multiple endocrine neoplasia, a history of childhood radiation to the head and neck, the postmenopausal state, a history of renal calculi or peptic ulcer, hypertension, the induction of hypercalcemia by thiazides, or an asymptomatic patient with a prolonged, stable mild hypercalcemia. The usefulness of the serum calcium, parathyroid hormone, chloride, phosphorus, serum 25-OHD, and 1,25-(OH)2D, and urinary calcium in the differential diagnosis of hypercalcemia is discussed. The pitfalls of an excessive reliance on the serum PTH in diagnosing hyperparathyroidism are stressed. The discriminant values of the serum calcium, chloride, phosphorus, and parathyroid hormone are explored, with the serum parathyroid hormone, chloride, and calcium proving most useful in separating primary hyperparathyroidism from other forms of hypercalcemia. Multivariate discriminant analysis using the serum calcium, phosphorus, and chloride and the hematocrit achieves an accuracy of 95-98% and is the most economical method of identifying hyperparathyroidism. The addition of the amino-terminal or intact PTH assay increases the accuracy to 99% and is essential in the presence of renal insufficiency.
 ...
PMID:Differential diagnosis of hypercalcemia. 176 70

In primary hyperparathyroidism molecular biology techniques applied to the pathological parathyroid tissue have shown that cell proliferation is monoclonal in many sporadic adenomas and in the largest parathyroid glands of multiple endocrine neoplasia type 1 (MEN-1). On the other hand, monoclonality has not been found in sporadic hyperplasia and in the smaller parathyroid glands of MEN-1. In addition, abnormalities have been observed in chromosome 11 which contains the parathyroid hormone (PTH) gene and the MEN-1 associated gene. The PTH gene was rearranged in sporadic adenomas, and there was a varying degree of chromosome 11 allele delection in sporadic adenomas and in MEN-1. The relationship between these abnormalities and parathyroid cell proliferation is controverted, and further studies are required to determine their exact role in the development of primary hyperparathyroidism.
 ...
PMID:[Mechanism of parathyroid cell proliferation in primary hyperparathyroidism]. 182 67


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>