Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A solid-phase radioimmunoassay was developed that measures the free alpha subunits of pituitary glycoprotein hormones (alpha PGpHs) and has negligible cross-reactivity with the intact hormones (less than 0.014% for thyroid-stimulating hormone [TSH], less than 0.1% for human chorionic gonadotropin [hCG], 0.8% for luteinizing hormone [LH], and 2.0% for follicle-stimulating hormone [FSH]). The assay is standardized with the alpha subunit of hCG but also reacts well with the alpha subunits of the other glycoprotein hormones (84% for alpha TSH, 77% for alpha FSH, and 64% for alpha LH). Concentrations as low as 0.3 micrograms/L can be reliably measured, and the 97.5% reference range in 27 healthy adults, including postmenopausal females, is less than or equal to 1.2 micrograms/L. Elevated preoperative alpha PGpH concentrations were found in 45 (9.4%) of 479 sera from patients with pituitary adenoma and 3 (4.5%) of 66 patients with nonadenomatous sellar lesions. Postoperative alpha PGpH levels were lower in 30 of 39 adenoma patients and 2 of 3 nonadenoma patients. In five (1%) of the patients with pituitary adenomas, alpha PGpH was the only elevated serum hormone marker. Serum values of alpha PGpH correlate weakly with alpha subunit immunocytochemical staining--95% of those with negative staining have normal alpha PGpH values, but only 18% of those with positive staining have elevated alpha PGpH values.
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PMID:Free alpha subunit of the pituitary glycoprotein hormones. Measurement in serum and tissue of patients with pituitary tumors. 169 8

Sixteen growth hormone (GH)-producing pituitary adenomas were studied for the expression of glycoprotein hormone subunits and cytokeratin by light microscopic immunohistochemistry. Cytokeratin immunoreactivity was demonstrated in all adenomas, but its intracytoplasmic distribution showed two distinct patterns; a prominent, dot-like pattern and a diffuse, perinuclear pattern. Seven adenomas (type 1) were exclusively composed of cells with cytokeratin in a dot-like pattern, whereas 9 adenomas (type 2) comprised of cells with cytokeratin of perinuclear distribution. The expression of alpha-subunit of glycoprotein hormone was significantly different between the two types of adenomas; 8 of 9 adenomas of type 2 contained many alpha-subunit immunoreactive cells but none of type 1 adenomas showed any immunoreactivity. Only a small number of adenoma cells were positive for beta-subunit of thyrotropin stimulating hormone in 3 adenomas of type 2. beta-subunits of follicle stimulation hormone and luteinizing hormone were negative in all adenomas. These findings suggest that the expression of glycoprotein hormone subunits in GH-producing adenomas may be closely linked to their types distinguishable by the cytokeratin distribution pattern.
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PMID:Expression of glycoprotein hormones and intracytoplasmic distribution of cytokeratin in growth hormone-producing pituitary adenomas. 171 59

The present study aimed at evaluating the anterior pituitary hormone levels in the inferior petrosal sinuses and in the peripheral blood of 55 patients affected by various pituitary disorders and undergoing perihypophysial phlebography on neurosurgical indication or for diagnostic purposes. The results indicated that in 6 patients with Cushing's disease and in 4 with hyperprolactinemia the secreting adenoma could be localized by inferior petrosal sinus sampling. Furthermore, the concentrations of all the pituitary hormones were found to be higher in the right and/or in the left inferior petrosal sinus than in peripheral blood, showing a clear gradient between central and peripheral samples. Moreover, the evaluation of hormone central/peripheral concentration ratios revealed noteworthy differences, namely, that central/peripheral concentration ratios of GH, ACTH, and PRL were significantly higher than those of TSH, FSH, and LH (p less than 0.01). On the contrary, no significant differences were found when the concentration ratios of GH, ACTH and PRL or TSH, FSH and LH were compared among themselves. This finding may be attributed to at least two factors: the increased pulsatility and the relatively short biological halftime of polypeptic hormones (GH, ACTH, and PRL) compared with glycoprotein hormones (TSH, FSH, and LH).
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PMID:Comparison of anterior pituitary hormone levels in the inferior petrosal sinuses and peripheral blood in various pituitary disorders during perihypophysial phlebography. 184 30

The c-erbB-2 proto-oncogene is known to encode a 185,000 molecular weight glycoprotein. This protein has been detected immunohistochemically in several human adenocarcinomas, suggesting that it may play a role in the development of these malignancies. In the otolaryngological field none of the adenocarcinomas expressing c-erbB-2 protein has yet been described. In this article we presented a case of parotid adenocarcinoma expressing the c-erbB-2 protein. In this case the adenocarcinoma was thought to have originated from pleomorphic adenoma. Immunohistochemically, the adenocarcinoma cells were stained and the remaining pleomorphic adenoma cells were not stained by polyclonal antibody against the c-erbB-2 protein. The expression of c-erbB-2 protein may have been related to the malignant development of the pleomorphic adenoma.
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PMID:Expression of c-erbB-2 protein detected in adenocarcinoma arising from parotid pleomorphic adenoma. 197 76

Gross cystic disease fluid protein-15 (GCDFP-15) is a 15-kd glycoprotein that is expressed by normal apocrine epithelia and in a majority of breast carcinomas. However, recent studies have demonstrated that this substance is also present in tumors of the salivary glands, sweat glands, and prostate gland. To determine whether the expression of CGDFP-15 might aid in the differential diagnosis of salivary gland lesions, the anti-GCDFP-15 monoclonal antibody D6 was applied to paraffin sections of 133 such neoplasms. Benign tumors (76% reactive) were more often labeled than malignant lesions (28% reactive) by this antibody; overall, 53 (41%) of 133 cases were positive for GCDFP-15. Notably, the tubuloglandular components in 17 (81%) of 21 pleomorphic adenomas were reactive, but no example of either adenoid cystic carcinoma or polymorphous low-grade adenocarcinoma were labeled. In contrast, 24% of adenocarcinomas stained with this antibody. The apparent expression of GCDFP-15 by a spectrum of salivary gland tumors supports their biologic relationship to lesions of the cutaneous apocrine glands and breast. Furthermore, the demonstration of this determinant may be of use in suggesting the salivary gland nature of poorly differentiated carcinomas of the head and neck, and it may facilitate the separation of pleomorphic adenoma from histologically similar malignant neoplasms in the salivary glands themselves.
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PMID:Gross cystic disease fluid protein-15 in salivary gland tumors. 199 83

The human colonic cell line PC/AA, derived from an adenoma, retains in vitro colonic cell differentiation, notably the production of mucus glycoproteins. The PC/AA adenoma cells produce an extracellular gel layer in culture. The PC/AA gel could be isolated by extraction of the cell cultures with guanidine hydrochloride. The extracted material was purified by gel filtration and caesium chloride density-gradient centrifugation and showed properties typical of mucus glycoproteins, namely, a carbohydrate content above 60% of dry weight rich in N-acetylgalactosamine and sialic acid and low in mannose; an amino acid composition with high serine threonine and proline content; a molecular weight above 1,000 kDa on Sepharose CL 4B chromatography and on SDS-polyacrylamide gel electrophoresis under reducing conditions (greater than 200 kDa); a buoyant density of approximately 1.48 g/ml and the release of oligosaccharides by the alkaline beta-elimination reaction. Comparison of the gel mucus glycoprotein purified from premalignant PC/AA cells with normal human colon mucin showed that it has a higher sialic acid content. This suggests that higher sialic acid levels may precede the development of malignancy.
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PMID:Characterization of a sialic-acid-rich mucus glycoprotein secreted by a premalignant human colorectal adenoma cell line. 224 93

Chromogranin-A (CgA), also termed secretory protein-I, is an acidic glycoprotein that is synthesized and secreted by cells of the diffuse endocrine and neuroendocrine system. Several previous studies had suggested that plasma levels of CgA were elevated in patients with primary hyperparathyroidism. In the present study we sought to examine expression of the CgA gene in human parathyroid tissue from patients with primary hyperparathyroidism. We characterized the mRNAs coding for CgA and beta-actin in parathyroid tissue fragments obtained from 12 patients with parathyroid adenomas, 11 patients with familial multiple endocrine neoplasia type I (FMEN I) with parathyroid hyperplasia, and 11 normal subjects. The mRNAs were detected and analyzed by dot and Northern blot hybridization using cDNA probes. CgA mRNA transcripts of 2.1 kilobases were detected in normal and pathological parathyroids. Similarly, beta-actin mRNA species of 2.1 kilobases was present in all tissues. The relative level of parathyroid tissue CgA mRNA, calculated as the CgA/beta-actin mRNA ratio, was 73 +/- 18 in parathyroid adenoma, 73 +/- 20 in FMEN I, and 100 +/- 9 in controls (mean +/- SE; expressed as a percentage of the control reference group value). There were no significant differences among the steady state levels of CgA mRNA levels in these three groups (F = 0.98; P = 0.39). These results demonstrate that expression of CgA mRNA is qualitatively and quantitatively normal in parathyroid tumors from patients with FMEN I and parathyroid adenoma.
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PMID:Expression of chromogranin-A messenger ribonucleic acid in parathyroid tissue from patients with primary hyperparathyroidism. 234

Serum glycoprotein hormone alpha-subunit levels were determined in 165 patients with pituitary adenomas. Elevated serum alpha-subunit levels were found in 17 patients (acromegaly, 5 of 58; prolactinoma, 6 of 56; nonfunctioning adenoma, 5 of 32; and ACTH-producing adenoma, 1 of 19), most of whom had normal serum TSH and gonadotropin levels. When TRH (0.5 mg) was injected iv in the 6 prolactinoma patients with elevated serum alpha-subunit levels, serum PRL and alpha-subunit levels increased in only 1 patient. Four acromegalic patients with high serum alpha-subunit levels received TRH; serum GH and alpha-subunit increased in 1 patient and did not change in 2, and only serum GH increased in the remaining patient. Oral administration of bromocriptine (5 mg), on the other hand, consistently decreased serum alpha-subunit and PRL levels in 2 patients with prolactinoma and alpha-subunit and GH levels in 1 acromegalic patient. When serum from 3 patients was subjected to Sephadex G-100 gel filtration, immunoreactive alpha-subunit eluted in a single peak, which emerged in fractions corresponding to [125I]TSH alpha. Concanavalin A (Con A) affinity chromatography revealed that the major portion of immunoreactive alpha-subunit was retained to Con A. A pituitary adenoma removed at surgery from a patient with acromegaly was studied in monolayer cell culture. Secretion of both alpha-subunit and GH from cultured adenoma cells was stimulated by TRH and suppressed by dopamine in a dose-dependent manner. Immunohistochemistry of the pituitary adenomas removed from patients with prolactinoma and acromegaly who had high serum alpha-subunit levels demonstrated alpha-subunit-containing cells as well as PRL- or GH-containing cells. These results suggest that elaboration of glycoprotein hormone alpha-subunit occurs without concurrent production of glycoprotein hormones in a substantial number of patients with pituitary adenomas and that alpha-subunit responses to stimuli in such adenomas are generally parallel with those of the concomitantly produced hormones.
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PMID:Secretion of glycoprotein hormone alpha-subunit by pituitary tumors. 243 40

Two pituitary gonadotroph adenomas were studied in vitro to characterize structure-function correlations. Both tumors were from men, aged 63 and 69 years, who had elevated blood levels of follicle-stimulating hormone (FSH) and normal blood luteinizing hormone (LH) and testosterone values. The surgically resected adenomas contained diffuse immunohistochemical positivity for beta-FSH, beta-LH, and alpha-subunit of glycoprotein hormones; by electron microscopy they were composed of well-differentiated gonadotrophs. In vitro, both tumors released FSH, LH, and alpha-subunit. Morphometric studies were performed on surgically resected and cultured adenoma cells. Compared with the surgical specimens, the cultured cells had decreased cytoplasmic volume densities of endoplasmic reticulum and Golgi apparatus and slightly increased cytoplasmic volume densities of secretory granules. Incubation with gonadotropin-releasing hormone (GnRH) for 2 and 24 hours increased FSH, LH, and alpha-subunit release by both tumors; morphometry after 2 consecutive days of exposure confirmed significant increases in cytoplasmic volume densities of endoplasmic reticulum and Golgi regions and marked decreases in that of secretory granules. There was no significant change in cell size, nuclear/cytoplasmic ratio, or secretory granule diameter. The two tumors differed in their response to gonadal steroids. Estradiol, testosterone, and progesterone stimulated release of FSH, LH, and alpha-subunit by one tumor and the morphologic changes paralleled the biochemical response; addition of testosterone suppressed the secretory and morphologic response to GnRH. The other tumor showed no significant response to estradiol or testosterone and addition of these steroids did not alter the response to GnRH. The results are consistent with the interpretation that GnRH stimulates not only release but also synthesis of gonadotropins by gonadotroph adenomas of men. The data also indicate variable sensitivity of these tumors to gonadal steroids with paradoxical stimulation alone and inhibition of response to GnRH. The structural changes correlate with the hormone release response in vitro.
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PMID:Structure-function correlations of human pituitary gonadotroph adenomas in vitro. 245 66

We have studied the effects of TRH and native gonadotrophin-releasing hormone (GnRH), and of a GnRH agonist (Buserelin; [D-Ser(But )6]GnRH(1-9) nonapeptide-ethylamide), on LH, FSH, alpha subunit and LH-beta subunit secretion from three human gonadotrophin-secreting pituitary adenomas in dispersed cell culture. During a 24 h study, treatment with 276 nmol TRH/l resulted in a significant (P less than 0.05) stimulated release of FSH and alpha subunit from all three adenomas, and LH from the two adenomas secreting detectable concentrations of this glycoprotein; treatment with 85 nmol GnRH/l significantly (P less than 0.05) stimulated the release of alpha subunit from all three, but FSH from only two and LH from only one adenoma. During a long-term 28-day study, basal FSH and alpha subunit concentrations were maintained, but secretion of LH, and LH-beta (detectable from one tumour only), declined with time from two of the three adenomas. Addition of Buserelin to the cultures resulted in the continuous (P less than 0.05) stimulation of alpha subunit secretion from all three adenomas, and of LH and FSH from two, whilst a transient stimulatory effect on LH and FSH secretion was seen from a third adenoma, with subsequent secretion rates declining towards control values. These data show that human gonadotrophin-secreting adenomas demonstrate variable stimulatory responses to hypothalamic TRH and GnRH, and that during chronic treatment with a GnRH agonist the anticipated desensitizing effect of the drug was not observed in two out of the three adenomas studied. The mechanisms for this is not clear, but such drugs are unlikely to be of therapeutic value in the management of gonadotrophin-secreting tumours. The data also suggest that GnRH and GnRH agonists have a differential effect on the in-vitro release of intact gonadotrophins and the common alpha subunit.
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PMID:Long-term effects of a gonadotrophin-releasing hormone agonist ([D-Ser(But)6]GnRH(1-9)nonapeptide-ethylamide) on gonadotrophin secretion from human pituitary gonadotroph cell adenomas in vitro. 246 May 76


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