Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of benign clear cell tumor ("sugar tumor") is reported. Light microscopy showed a proliferation of clear cells with a rich blood supply and endocrinoid pattern. Ultrastructurally, cells were loaded with glycogen both free and membrane-bound. The cellular origin of the benign clear cell tumor of the lung is still uncertain.
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PMID:[Clear cell tumor of the lung (sugar tumour). Study of a case]. 192 76

We present an autopsy case of a 29-week-old male fetus with a very unusual set of congenital granular cell tumors, including gingival epulis and granular cell lesions of the kidneys, lung, heart, esophagus, small and large intestine, thyroid, adrenals, spleen, urinary bladder, testis, pituitary, and leptomeninges. The granular cells were distributed mainly through the stroma of the organs, but they also involved the epithelial lining of the seminiferous and renal tubules. Ultrastructurally, the gingival, pulmonary, and renal tumors were basically the same in appearance as membrane-bound heterogeneous bodies. Immunohistochemical studies were negative for S100 protein, lysozyme, alpha 1-antitrypsin, cytokeratin, and vimentin in the gingival mass as well as in other systemic lesions. The immunohistochemical reaction pattern of the granular cells in our case was more like the cells of the congenital granular cell epulis rather than adult granular cell tumor because of its negative reaction to S100 protein. However, the involvement pattern was that of the adult form of granular cell tumor. Several developmentally different cells, such as renal tubular epithelial cells, seminiferous tubular cells, gingival stromal cells, and parenchymal cells of many organs, were involved in this granular cell process. The myofibroblastlike cells seen in the region of segmental dysplasia of the kidney showed the same cytoplasmic material as in typical granular cells. Based on these findings, it is suggested that a histogenesis of multiple cell origin of the granular cell tumor could be strongly supported.
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PMID:Congenital granular cell tumor with systemic involvement. Immunohistochemical and ultrastructural study. 192 90

The features of two patients with multiple endocrine neoplasia type IIb are described. Patient 1, a 9-year-old boy with marfanoid features, presented with chronic constipation and failure to thrive since infancy. Patient 2, a 12-year-old boy with marfanoid features, presented with a five-year history of persistent cervical lymphadenopathy. In patient 1, the myenteric and submucosal nerve plexuses at all levels of the small and large intestines were comprised of diffusely disorganized, hyperplastic, mature ganglion cells and nonmyelinated nerve fibers. Nerve plexus dissection with morphometric analysis showed marked thickening of the myenteric plexus with a quantitative increase in neural tissue. Patient 2 had a submucosal neuroma of the tongue. Both patients had occult medullary thyroid carcinoma, and patient 2 had cervical lymph node metastases. Both neoplasms showed positive staining for cytokeratin, carcinoembryonic antigen, calcitonin, bombesin, chromogranin, serotonin, and Leu 7. Electron microscopy showed membrane-bound, intermediate-sized, dense-core neurosecretory granules in tumor cells. In patient 2, calcitonin-positive amyloid was present with localization of calcitonin by immunoelectron microscopy to cytoplasmic secretory granules and to extracellular amyloid fibrils. These cases illustrate the potential for missed or delayed diagnosis in multiple endocrine neoplasia syndromes.
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PMID:Pathological features of multiple endocrine neoplasia type IIb in childhood. 197 36

The potent diuretic and natriuretic peptide hormone atrial natriuretic factor (ANF), with vasodilatory activity also stimulates steroidogenic responsiveness in Leydig cells. The actions of ANF are mediated by its interaction with specific cell surface receptors and the membrane-bound form of guanylate cyclase represents an atrial natriuretic factor receptor (ANF-R). To understand the mechanism of ANF action in testicular steroidogenesis and to identify guanylate cyclase/ANF-R that is expressed in the Leydig cells, the primary structure of murine guanylate cyclase/ANF-R has been deduced from its cDNA sequence. A cDNA library constructed from poly(A+) RNA of murine Leydig tumor (MA-10) cell line was screened for the membrane-bound form of ANF-R/guanylate cyclase sequences by hybridization with a rat brain guanylate cyclase/ANF-R cDNA probe. The amino acid sequence deduced from the cDNA shows that murine guanylate cyclase/ANF-R cDNA consists of 1057 amino acids with 21 amino acids comprising the transmembrane domain which separates an extracellular ligand-binding domain (469 amino acid residues) and an intracellular guanylate cyclase domain (567 amino acid residues). Upon transfection of the murine guanylate cyclase/ANF-R cDNA in COS-7 cells, the expressed protein showed specific binding to 125I-ANF, stimulation of guanylate cyclase activity and production of intracellular cGMP in response to ANF. The expression of guanylate cyclase/ANF-R cDNA transfected in rat Leydig tumor cells stimulated the production of testosterone and intracellular cGMP after treatment with ANF. The results presented herein directly show that ANF can regulate the testicular steroidogenic responsiveness in addition to its known regulatory role in the control of cardiovascular homeostasis.
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PMID:Molecular cloning and expression of murine guanylate cyclase/atrial natriuretic factor receptor cDNA. 197 87

Protein Kinase C (PKC) has been a principal regulatory enzyme whose function has been intensely investigated in the past decade. The primary features of this family of enzymes includes phosphorylation of serine and threonine residues located on basic proteins and peptide in a manner that is stimulated by calcium, phospholipid, and either diacylglycerol or phorbol esters. An additional intriguing feature of the enzymes is its ability to form two membrane-associated states, one of which is calcium dependent and reversible and the second is an irreversible complex which has the characteristics of an intrinsic membrane protein. Formation of the irreversible membrane-bound form is greatly facilitated by calcium and the tumor-promoting phorbol esters but does not appear to include covalent changes in the PKC structure. The intrinsic membrane-bound form is a very different enzyme in that its activity is no longer dependent on the other cofactors. It is proposed that formation of the irreversible membrane-bound form may be a mechanism for generating long-term cell regulation events where transient cell signals and second messengers induce long-term changes in the distribution of an enzyme in the cell. This property may be common to a number of regulatory proteins that are known to be distributed between the cytosol and membrane-fractions in the cell. Unfortunately, many problems have confronted study of PKC mechanism using the in vitro assay. This assay involves aggregation of the substrate, phospholipid, and enzyme to form a discontinuous mixture. Such a complex system prevents straightforward interpretation of enzyme kinetic data. Although many compounds affect the in vitro activity of PKC, most appear to accomplish this by relatively uninteresting mechanisms such as interference with the aggregation process. While some highly potent inhibitors undoubtedly interact directly with PKC, they also inhibit other enzymes and there are no entirely specific inhibitors of PKC known. Speculation on the possible roles of PKC in cell regulation are abundant and exciting. However, delineation of the regulatory roles of PKC may require another decade of intense effort.
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PMID:Activation and regulation of protein kinase C enzymes. 201 Apr 34

A case of alveolar soft-part sarcoma located in the uterine corpus is reported. It was an incidental finding in the hysterectomy specimen of a 40-year-old woman. Light and electron microscopic examination revealed periodic-acid-Schiff-positive, diastase-resistant, membrane-bound cytoplasmic granules and crystalloids. Tumour cells expressed immunoreactivity with vimentin, desmin, cytokeratins, NK1/C3 and HMB-45 antibodies. Four years postoperatively, the patient is still alive without evidence of disease. Differential diagnoses, immunocytochemistry and clinical management of uterine alveolar soft-part sarcoma are discussed and the literature reviewed.
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PMID:Alveolar soft-part sarcoma of the uterine corpus: histological, immunocytochemical and ultrastructural study of a case. 203 61

An 82-year-old woman had a dark red to purple tumor on the left buttock that had gradually enlarged during the last 5 years. Although routine histologic examination was not sufficient for diagnosis, neuroendocrine carcinoma was diagnosed by immunohistochemical and ultrastructural studies. Immunohistochemical-positive reactions to neurofilament, cytokeratin, neuron-specific enolase, and epithelial membrane antigen were noted. Electron microscopically, membrane-bound, dense core granules that yielded a positive uranaffin reaction and intermediate filaments in the perinuclear area were observed in the cytoplasm of most tumor cells. Desmosome-like structure between them was also found. Approximately 6 months after local excision, metastatic lesions developed in the regional lymph nodes and liver.
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PMID:Giant neuroendocrine (Merkel cell) carcinoma of the skin. 205 Aug 48

The involvement of protein kinase C (PKC) in regulation of cellular properties related to tumor cell invasiveness was tested in a murine methylcholanthrene-induced fibrosarcoma tumor cell model. A metastatic clone (IE7) derived from the T10 fibrosarcoma was found to possess 30 and 90% more cytosolic and membrane-bound PKC, respectively, compared with the IC9 metastatic clone. Intravenous injection of IE7 but not IC9 cells resulted in lung tumor formation. Long-term (3 months) treatment of IE7 cells with 500 ng/ml phorbol 12,13-dibutyrate (PDB) resulted in a 4-fold reduction in total PKC activity and increase in the tumor cell metastatic ability. Short-term (2h) PDB treatment induced cytosol-to-membrane PKC translocation and decreased the IE7 cells' ability to form hematogenous metastases. Treatment of IC9 cells with PDB did not render them metastatic. To test the possible involvement of distinct PKC isoenzymes in the determination of metastatic properties, we stained the cells with appropriate anti-PKC antibodies followed by FACS analysis. IC9 and IE7 cells exhibited similar levels of fluorescent intensity when stained with either anti-PKC alpha or anti-PKC beta antibodies. The relative proportion of PKC alpha and PKC beta was not changed following short-term PDB treatment of cells, but the intensity of staining was reduced 1.5- to 2-fold following long-term PDB treatment of both cell types. The results indicate that phorbol ester-induced alterations in PKC levels and subcellular distribution affect the metastatic ability of tumor cells and suggest that tumor promoting agents that promote induction of primary tumors may also affect tumor spread by regulating hematogenous metastases formation.
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PMID:Effect of protein kinase C activating tumor promoters on metastases formation by fibrosarcoma cells. 206 Oct

A peculiar case of astrocytoma showing a histological appearance similar to granular cell tumor was reported. The tumor consisted of large round cells containing numerous intracytoplasmic eosinophilic granules, partially intermingled with atypical astrocytes, and part of it showed a transition to distinct areas of fibrillary astrocytoma. The granules were periodic acid-Schiff-positive (with resistance to diastase digestion), negative for fat stains and revealed lectin-binding patterns similar to those in granular cell tumor. Ultrastructurally the granules were partially membrane-bound, dense bodies compatible with secondary lysosomes. It was suggested that the granular cells were of astrocytic origin because of their immunoreactivity for glial fibrillary acidic protein (GFAP) and ultrastructural observation of intermediate filaments corresponding to GFAP.
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PMID:Astrocytoma with granular cell tumor-like changes. Report of a case with histochemical and ultrastructural characterization of granular cells. 216 87

We report an unusual case of malignant mixed mesodermal tumor of the uterine corpus associated with various symptoms related to overproduction of catecholamine by the tumor cells. Histologically, the tumor was dominated by carcinomatous epithelium with foci of malignant mesenchyma. The type of epithelium was endometrioid with papillary adenocarcinomas containing foci of malignant squamous epithelium. The malignant mesenchyma consisted mainly of a fibrous stroma with many large and bizarre cells and spindle cells mimicking leiomyosarcoma, many of which were pleomorphic and contained large bizarre hyperchromatic nuclei. Foci of atypical adult-type cartilage and neoplastic osteoid formation were noted. In the tumor tissue, membrane-bound neurosecretory-type cytoplasmic granules were demonstrated by electron microscopy and polypeptide hormone synthesis was demonstrated by immunohistochemistry. Furthermore, the patient suffered frequent attacks of sudden hypertension with hypercatecholaminemia.
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PMID:A malignant mixed mesodermal tumor of the uterine corpus with hypercatecholaminemia. 216 44


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