Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Nonfunctioning pituitary adenomas represent approximately 25 per cent of all clinically apparent pituitary tumors. The tumors are usually macroadenomas and present with symptoms caused by mass effect or hypopituitarism. In addition to structural studies and assessment of pituitary hormone function, all patients with clinically nonfunctioning tumors should have an alpha-subunit determination. High normal or elevated gonadotropins in this setting are suspicious for an underlying gonadotroph adenoma. Alpha subunit, LH-beta, and FSH-beta can be measured in the serum of some patients with nonfunctioning adenomas. Other groups of patients may have tumors in which defects in hormone biosynthesis or processing prevent detectable hormone hypersecretion, or no hormones are produced. The majority of nonfunctioning adenomas have evidence of gonadotropin or glycoprotein hormone subunit production when studied in vitro. An additional tumor group has evidence of ACTH production without biochemical hypercortisolism. Transsphenoidal decompression is the treatment of choice for patients with nonfunctioning adenomas. Pituitary function may improve following surgery in a subset of patients. Postoperative conventional radiotherapy is recommended when there is evidence of residual tumor and/or extensive extrasellar extension preoperatively.
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PMID:Nonsecreting pituitary tumors. 331 3

The aim of this study was to demonstrate several lectin-binding sites in human parathyroid tissue and to correlate these results with functional activity. The following lectins were tested for binding sites with certain carbohydrates (in parentheses): Arachis hypogea (PNA) (galactose), Ulex europaeus I (UEA) (fucose) and concanavalin A (ConA) (mannose). In addition to normal parathyroids used as controls (13 cases), we examined adenomas associated with a clinical picture of primary hyperparathyroidism of differing severity (31 cases), atrophic glands contralateral to a hyperfunctioning adenoma (7 cases), and secondary (renal) hyperplasia (12 cases). Use of PNA (with and without neuraminidase treatment) and UEA yielded negative staining in normal glands, a wide variety of reactions in adenomas, and frequent dense precipitates in atrophic parathyroids, whereas ConA yielded positive staining in all kinds of parathyroid tissue. Assessment of functional activity of adenomas by clinical parameters (pre-operative serum levels of calcium and parathormone) displayed a significant correlation with the semiquantitative grading of the histochemical reactions after PNA and UEA. Lectin-binding sites in parathyroid chief cells of adenomas are believed to indicate some of the cell structures or products directly involved in the secretory process, including degradation. Although ConA may recognize constituent parathyroid glycoproteins, the binding sites for PNA and UEA are thought to be partially associated with secretory glycoprotein (SP-I), as is known from animal experiments. The positive reaction of the atrophic gland may result from degradation enforced by exposure of primarily non-terminal carbohydrate components.
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PMID:Lectin-binding sites in human parathyroid tissue. 373 21

Cancerous lesions and nonneoplastic mucosa of surgically extirpated specimens from 94 patients with colorectal carcinoma (of the right colon, 31 patients; of the left colon, 29 patients; and of the rectum, 34 patients) and endoscopically polypectomized specimens from 18 patients with rectal adenoma were examined with fluorescein isothiocyanate-conjugated or horse-radish peroxidase-conjugated Ulex europaeus agglutinin-I (UEA-I) specific to a certain terminal alpha-L-fucosyl residue in glycoconjugates. Of the 31 patients with right colon cancers, 22 showed positive UEA-I binding in the neoplastic cell apexes, apical luminal borders, and luminal secretions. The adjacent nonneoplastic mucosa of all 31 patients, however, demonstrated positive UEA-I binding in the goblet cell mucus. UEA-I binding was positive for 23 of the 29 left colon cancers and for 28 of the 34 rectal cancers, although UEA-I binding was not revealed in the adjacent nonneoplastic mucosa for most of the cases. Of the 18 rectal adenomas, 12 specimens showed positive UEA-I binding in the apical secretions of their adenoma cells. Marked regional differences of UEA-I binding in the nonneoplastic mucosae indicated that the constituents of glycoprotein with UEA-I binding sites in goblet cell mucus differed significantly between the human right and left large bowels. Positive UEA-I binding in many rectal cancerous and adenomatous lesions suggested that a neoplastic glycoprotein with alpha-L-fucosyl residue was produced or that the terminal carbohydrate structure of glycoprotein present in the nonneoplastic mucosa was altered to bind easily with UEA-I after the neoplastic transformation had occurred. A possible relation of this UEA-I binding to blood group H(O) substance is discussed.
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PMID:Glycoconjugate with Ulex europaeus agglutinin-I-binding sites in normal mucosa, adenoma, and carcinoma of the human large bowel. 618 Dec 81

The morphologic features of four pituitary adenomas, removed from 2 men and 2 women between 31 and 62 years of age, are reported. The tumors contained growth hormone (GH), prolactin (PRL), and one or more glycoprotein hormones--usually thyrotropin (TSH). Three tumors were associated with acromegaly and one with hyperprolactinemia. Hyperthyroidism was not evident in any of the patients. In the tumors of acromegalic subjects, GH-containing cells were the most numerous, whereas PRL cells were dominant in the adenoma accompanied by hyperprolactinemia. Electron microscopy revealed plurimorphous tumors comprised of various proportions of morphologically different cell types: densely granulated GH cells, TSH-like cells, and the less common mammosomatotrophs and PRL cells. It is suggested that pituitary adenomas producing GH, PRL, and glycoprotein hormones derive from the same precursor; their immunocytochemical profile, fine structural appearance, and endocrine function may depend on the degree and direction of the cellular differentiation.
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PMID:Pituitary adenomas producing growth hormone, prolactin, and one or more glycoprotein hormones: a histologic, immunohistochemical, and ultrastructural study of four surgically removed tumors. 632 96

Peanut lectin (PNA) has a specificity for the disaccharide beta-D-Gal-(1 leads to 3)-D-GalNac which is the purported antigenic determinant for the T blood group antigen (TAg). This TAg is considered the immediate precursor of the MN blood group substance. In normal colonic epithelium, PNA binds to the supranuclear (stalk) portion of epithelial cells. This corresponds to the detection of beta-DGal-(1 leads to 3)-D-GalNac in nascent oligosaccharide chains in the Golgi cisternae prior to addition of terminal sialic acid. Colonic carcinomas bind PNA in the "region" of the glycocalyx or in the apical portion of the cell, which represents incomplete glycoprotein synthesis. Eighty-two percent of tubular adenomas, 80% of villous adenomas, and 91% of adenomas with in situ cancer expressed PNA in a supranuclear distribution, reminiscent of normal colonic epithelium. This stalk distribution was seen in goblet cells. Twenty-five percent of tubular adenomas, 43% of villous adenomas and 60% of adenomas with in situ cancer (adenoma portion) expressed PNA in an apical cytoplasmic and/or glycocalyx pattern among nonmucinous columnar cells. In 80% of the cases, the in situ cancer itself expressed PNA in an apical cytoplasmic and/or glycocalyx pattern. Fetal and most colon cancer cells fail to produce mucin goblets and make incomplete glycoproteins. The cytologic localization of TAg by PNA corresponds to the cells' ability to produce mucin goblets. Most adenomas consist of goblet cells, localize TAg to the stalk, and probably make complete MN glycoprotein as does normal colonic epithelium. However, in adenomas, nonmucinous columnar cells localize TAg to the apical cytoplasm and/or glycocalyx region and represent incomplete blood group glycoprotein synthesis.
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PMID:Peanut lectin-binding sites in polyps of the colon and rectum. Adenomas, hyperplastic polyps, and adenomas with in situ carcinoma. 665 97

Monoclonal antibodies have been generated using membrane-enriched extracts of human metastatic mammary carcinoma lesions (Colcher et al., 1981), some of which demonstrated binding to the surface of human colon carcinoma cell lines. We report here an analysis of the reactivity of three of these monoclonal antibodies with formalin fixed tissue sections of human colon adenocarcinomas and adenomas. The three monoclonals employed were B72.3, which is reactive with a 220-400 kdal high molecular weight glycoprotein complex; B6.2, reactive with a 90 kdal glycoprotein, and B1.1, which is reactive with the 180 kdal glycoprotein CEA. B1.1 was least selective in its reactivity to colon carcinoma versus adenoma lesions. When 10 micrograms/ml of purified B1.1 IgG were used per slide, 94% (15 of 16) of carcinomas and 83% (15 of 18) adenomas showed reactivity. Monoclonal B72.3 demonstrated the most selective reactivity for carcinomas. Eighty-two percent (14 of 17) of carcinomas were positive while none of 18 adenomas examined showed reactivity with more than a few percent of adenoma cells positive. When a low concentration of purified B72.3 immunoglobulin was used per slide, 8 of 16 carcinomas and none of 46 adenomas or normal colon epithelium samples scored positive. Monoclonal B72.3 also reacted with cells in areas of "atypia" within adenomas. The reactivity of monoclonal B6.2 was intermediate as compared to B1.1 and B72.3 in its selectivity of reactivity for carcinoma cells. A heterogeneity in the populations of tumor cells showing reactivity with the three monoclonals was observed within many of the tumor masses. Both colon adenocarcinomas and adenomas can now be placed in several distinct groups based on their expression of antigens reactive with the three monoclonal antibodies employed.
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PMID:Differential reactivity of monoclonal antibodies with human colon adenocarcinomas and adenomas. 685 72

Tenascin, a novel six-armed extracellular matrix glycoprotein, was immunohistochemically examined in the human normal adult colon, and colonic neoplasms such as tubular adenomas, primary and metastatic adenocarcinomas. In contrast to previous reports, tenascin was hardly detectable in the normal adult colons, being predominantly localised in the fibrous stroma surrounding the glandular epithelia of the neoplastic lesions. The neoplastic cells themselves were totally negative for tenascin expression. Both the tubular adenoma tissues and the superficial layer of well-differentiated adenocarcinomas in general were intensely reactive to tenascin antibody, and the staining intensity increased as the adenoma became more atypical in cases of tubular adenomas. By pretreatment of the paraffin-embedded tissue sections with pepsin, the distribution of tenascin was often intensified considerably and distinct localisation was more clearly demonstrated in the colonic tumour tissues. Tenascin was also biochemically purified from human invasive colonic carcinomas, and this cancerous tissue tenascin was compared with that extracted from a human umbilical cord fibroblast cell line in terms of molecular heterogeneity. Two major isoforms of the purified tenascin from colonic cancer tissues were found to have relative molecular masses of 250 kD and 190 kD, which were almost identical to those of human foetal fibroblast tenascin glycoproteins. In addition, several lower molecular weight isoforms were frequently detectable in the cancerous tissues, which might represent immuno-reactive tenascin isoforms proteolytically digested in human colonic carcinomas in vivo.
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PMID:Specific expression of tenascin in human colonic neoplasms. 768 38

The presence of the extracellular matrix glycoprotein tenascin was studied immunohistochemically in normal human salivary glands and in pleomorphic adenomas. Its expression was compared to that of fibronectin, and type IV collagen. In the normal salivary gland, tenascin was found with interruptions in periductal tissues, and continuously in blood vessels, fat cells and around nerve bundles. In pleomorphic adenoma, tenascin was detected surrounding the clusters of epithelioid cells, in areas with a myxoid and a chondroid matrix, and around some myoepithelial cells as a halo. As compared to fibronectin, there is a similar location of tenascin and fibronectin around tumor cell clusters but not in myxoid and chondroid matrices. Fibronectin was found around the cells in chondroid matrix. In conclusion, tenascin is not only found in malignant tumors but also in benign tumors such as pleomorphic adenoma. The presence of tenascin as a halo around myoepithelial cells suggests a role of these cells in development of myxoid and chondroid matrices.
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PMID:Immunohistochemical expression of tenascin in normal human salivary glands and in pleomorphic adenomas. 768 69

In this study, we compared the clinical and endocrinological characteristics, neuroimaging findings, surgical outcome, and conventional histological findings (including immunohistochemistry) with the electron microscopic appearance of 31 growth hormone (GH)-producing adenomas. By electron microscopy, these 31 tumors were divided into 23 densely granulated somatotroph adenomas (DG adenomas) and 8 sparsely granulated somatotroph adenomas (SG adenomas). SG adenomas more frequently affected younger women, but no significant correlation was found between the adenoma type and the characteristic signs and symptoms of acromegaly, the incidence of diabetes mellitus or hypertension, or the basal serum GH and insulin-like growth factor I levels. A distinct response of GH to thyrotropin-releasing hormone, bromocriptine, or GH-releasing hormone was significantly more common in patients with DG adenomas than in those with SG adenomas, whereas the incidence of a response to gonadotropin-releasing hormone or oral glucose was not significantly different between the two groups. An analysis of neuroimaging findings and surgical results indicated that SG adenomas were more likely to be macroadenomas with suprasellar extension or invasive tumors and had a lower surgical cure rate. However, postoperative radiotherapy seemed to be similarly effective in both types of adenoma to prevent a tumor recurrence and to reduce postoperative GH basal level in serum. Light microscopy showed that DG adenomas were mainly acidophilic and were immunopositive not only for GH but also for prolactin (43%), the beta subunit of thyroid-stimulating hormone (26%), and the alpha subunit of glycoprotein hormone (87%), whereas SG adenomas were almost all chromophobic and only revealed immunopositivity for GH.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Growth hormone-producing pituitary adenomas: correlations between clinical characteristics and morphology. 768 91

The effects of human recombinant insulin-like growth factor 1 (IGF-1) on the secretion, viability, and proliferation of dispersed human anterior pituitary adenomas secreting FSH, LH, and alpha-subunit (alpha-su) were examined in vitro over 4 h and 4 days. The acute effect of IGF-1 on secretion over 4 h was examined in four tumors secreting FSH, LH, and alpha-su. IGF-1 (100 nmol/L) reduced LH compared to control (100%) in one tumor (61%, P < 0.01), and three tumors remained unaffected. FSH and alpha-su secretion were insufficient to measure over 4 h. Nine tumors were studied over 4 days; relative to control, IGF-1 (100 nmol/L) increased FSH secretion in all seven tumors secreting FSH (28-266%, P < 0.05) and increased alpha-su secretion in all four tumors studied (36%, 63%, 91%, and 121%, P < 0.05). IGF-1 reduced LH secretion in four/nine tumors (13%, 23%, 32%, and 50%, P < 0.05). Dose response curves (1-100 nmol/L IGF-1) were performed on three tumors cosecreting FSH and LH. Stimulation of FSH was achieved with either 1 or 10 nmol/L IGF-1, a single tumor in which alpha-su was measured showed maximal stimulation at 10 nmol/L IGF-1, and one of three tumors showed LH inhibition with 100 nmol/L IGF-1. In situ viability of attached cells was assessed with fluorescein and propidium iodide in seven tumors. After 4 days' exposure to 100 nmol/L IGF-1, in situ viability was increased in five tumors (range 12-19%, 15 +/- 1.3% SEM, P < 0.05). The effects of IGF-1 on the adenoma cell proliferative S-phase fraction was determined in six tumors after 4 days of treatment using double immunostaining with bromodeoxyuridine incorporation for 1 h. In four/six adenomas that stained positive for bromodeoxyuridine in the controls (1-5.6%), the S-phase fraction was increased by 100 nmol/L IGF-1 [(range 2.1-10.6%, increase 90-220%) (P < 0.05)]. These results show that IGF-1 has differential effects on gonadotropins from human pituitary adenomas, stimulating intact FSH and alpha-su, inhibiting or being without effect on intact LH in vitro, and increasing both viability and number of tumorous glycoprotein-secreting cells entering into the S-phase of proliferation.
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PMID:Differential effects of insulin-like growth factor 1 on the hormonal product and proliferation of glycoprotein-secreting human pituitary adenomas. 769 62


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