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

Explants from a glioblastoma multiforme were maintained for 4 weeks in a three-dimensional Gelfoam matrix culture in order to study the synthesis of alpha 2-antiplasmin (alpha 2AP), alpha 2-macroglobulin (alpha 2M), plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (t-PA). Since the organ culture system promotes cellular differentiation in gliomas with increasing time in vitro, secretion of the proteinase inhibitors and t-PA was examined at weekly intervals. Increased immunohistochemical staining for glial fibrillary acidic protein, a marker of astroglial differentiation, was observed in the explants with advancing time in culture. The proteinase inhibitors alpha 2AP and alpha 2M were secreted into the medium in all 4 weeks, while PAI-1 was detected at significant concentrations by an enzyme-linked immunosorbent assay (ELISA) in Weeks 3 and 4 only. The quantity of each inhibitor secreted into fresh medium during a 24-hour interval increased with the age of the tumor explants in the Gelfoam culture system. At no time was a sensitive ELISA able to detect t-PA in the culture medium. This study demonstrates that glioblastoma multiforme cells in primary organ culture can secrete three major fibrinolysis proteinase inhibitors. The appearance of PAI-1 only after extensive culturing of the explants suggests a possible correlation with neoplastic astroglial maturation.
 ...
PMID:Secretion of alpha 2-macroglobulin, alpha 2-antiplasmin, and plasminogen activator inhibitor-1 by glioblastoma multiforme in primary organ culture. 169 91

The authors present a case of central neurocytoma in a 34-year-old female who had experienced intermittent headaches over a 10-year period. On computed tomographic (CT) scans and magnetic resonance images, the tumor appeared as a large, calcified mass occupying both lateral ventricles. A right parieto-occipital craniotomy was performed and the tumor was totally removed. While the light microscopic findings suggested a diagnosis of oligodendroglioma, electron microscopic examination demonstrated clear vesicles, microtubules, and synaptic structures within the abundant cytoplasmic processes of the tumor cells. Immunohistochemical examination showed the tumor cells to be strongly positive for neuron-specific enolase, sparsely positive for S-100 protein, and negative for glial fibrillary acidic protein. The final histological diagnosis was central neurocytoma. The postoperative course was uneventful and no further treatment was administered. She has no neurological deficits and CT has shown no evidence of recurrence during the 2 years since her surgery. Central neurocytoma is a rare tumor arising in the lateral ventricle, and the diagnosis is mainly based on electron microscopic findings. Since central neurocytoma appears to have a good prognosis following total removal alone, it is very important to distinguish between this and other ventricular tumors.
 ...
PMID:Central neurocytoma--case report. 169 45

Various immunohistochemical markers were detected in 27 cases of human retinoblastoma by immunohistochemical avidin-biotin-peroxidase complex and peroxidase-antiperoxidase techniques using mono- and polyclonal antibodies. The glial markers, glial fibrillary acidic protein and Leu-7, were detected in the natural retinal component and perivascular glial cells within the tumor mass. In 4 among 27 cases Leu-7 was positive in the glial cells which were interspersed randomly among tumor cells and not associated with blood vessels. The neural marker, neuron-specific enolase, stained strongly positive in undifferentiated tumor cells and weakly positive in rosettes and fleurettes in most of the cases (21/27). Opsin, the photoreceptor marker, which is present only in the outer segment of photoreceptor cells, was detected in tumor cells of fleurettes in one case and also in rosettes in 6 cases. These results support the view that retinoblastoma has a predominantly neuronal nature with significant photoreceptor-like differentiation and rarely glial differentiation.
 ...
PMID:Immunohistochemical studies of retinoblastoma. 169 15

Immunohistochemical studies using immunoperoxidase staining for glial fibrillary acidic protein (GFAP), S-100 protein, and factor VIII-related antigen (VIII-RAg) were performed on 10 hemangioblastomas of the central nervous system to determine the origin of stromal cells. No cytoplasmic immunoreactivity for anti-GFAP, anti-S-100 protein, or anti-VIII-RAg was detected in most stromal cells. A small number of GFAP-positive cells were found only in the periphery of the tumor; they were thought to be trapped astrocytes or stromal cells taking up GFAP. Most stromal cells had abundant, clear cytoplasm with some microfilaments and lipid vacuoles. Cylindrical cytoplasmic processes and intermediate junctions were observed in some stromal cells, but most cells did not possess any junctional device. No stromal cell possessed any feature clearly suggesting endothelial cells or pericytes. Our immunohistochemical and ultrastructural investigations did not support the theories of stromal cell origin from astrocytes or endothelial cells. We concluded that stromal cells can be regarded as an aberrant cell type of angiogenic mesenchymal derivation.
 ...
PMID:Hemangioblastomas of the central nervous system--immunohistochemical and ultrastructural study. 170 Mar 15

A malignant Triton tumor in a 9-year-old boy is described. The first biopsy which was taken from the thenar prominence was diagnosed as a monophasic fibrous synovial sarcoma based on the finding of a spindle cell neoplasm with plump nuclei and cytokeratin expression. The true nature of the tumor became apparent when a second biopsy was investigated. In this specimen a rhabdomyosarcomatous component was found in association with a spindle cell sarcoma fulfilling the criteria of a malignant schwannoma. Immunohistochemical staining using antibodies against vimentin, desmin, muscle-specific actin, cytokeratin, glial fibrillary acidic protein, protein S-100, Leu 7 and myoglobin served to distinguish the two tumor components and documented the possible reactivity of malignant Triton tumor for cytokeratins.
 ...
PMID:Cytokeratin expression in malignant Triton tumor. 170 Oct 49

Sixty-seven tumor specimens of epithelial choroid plexus neoplasms obtained by 60 biopsies and 7 autopsies from 52 patients were investigated. Diagnoses of the first operations were choroid plexus papilloma (PP; 32 cases), choroid plexus papilloma with histological atypies (atypical PP; 6 cases), and choroid plexus carcinoma (PC; 14 cases). Carcinoembryonic antigen was expressed by 2 of the 3 biopsies autoptically recognized as metastatic carcinomas and by 2 autopsy cases of PC, while it was absent in all biopsies of true choroid plexus tumors. Tumor cells positive for transthyretin (TTR, prealbumin), S-100 protein (S100), and glial fibrillary acidic protein (GFAP) were detected in 39, 46 and 13, respectively, of the 49 cases of true choroid plexus tumors. Fourth ventricle tumors expressed more S100 (number of positive tumor cells) than lateral ventricle tumors, PP more S100 and TTR than atypical PP/PC. Tumors from patients 20 years of age and older expressed more GFAP and TTR than tumors from younger patients. Of the 30 patients with complete follow-up 19 were alive 2 to 11 years after surgery, including 7 recurrencies. Eleven died from the tumor 4 months to 7 years after surgery. The following histopathologic features (in order of decreasing significance) were correlated with poor prognosis (recurrency or fatal outcome): less than 50% of the tumor cells heavily positive for S100, presence of mitoses, absence of TTR-positive cells, brain invasion by cell nests, absence of marked stromal edema, and presence of necrotic areas. Our results indicate that some histologic features correlate significantly with poor prognosis and that immunohistochemical results correlate with tumor localization, age, and malignancy.
 ...
PMID:Clinicopathologic correlations in epithelial choroid plexus neoplasms: a study of 52 cases. 170 84

The author studied four subcutaneous soft tissue tumors, similar to those recently described by Enzinger and associates (Am J Surg Pathol 1989;13:817) by the name "ossifying fibromyxoid tumor," by immunohistochemistry and electron microscopy to further understand the cellular nature of this lesion. The four tumors were composed of uniform round cells often surrounded by a lacunar space. The tumors often contained a peripheral zone of metaplastic bone. The cellularity was high, but the mitotic rate was low, suggesting a benign or borderline nature of the lesion. Longer follow-up was available for three cases, showing recurrence-free survival times of 11, 8, and 3 years. Immunohistochemistry studies revealed that all tumors were strongly positive for S-100 protein and focally positive for Leu-7, whereas melanoma-specific marker HMB45 was negative. Vimentin was the main type of intermediate filament protein, and one case also contained scattered glial fibrillary acidic protein-positive cells. Epithelial markers (keratins, epithelial membrane antigen), desmin, and muscle actins were negative. Electron microscopic examination showed partial, sometimes reduplicated, basal lamina surrounding many cells. Complex cell processes were also present. No myofilaments were found. The immunohistochemical and electron microscopic results may suggest that this tumor has Schwann's cell differentiation.
 ...
PMID:Ossifying fibromyxoid tumor of soft parts. Additional observations of a distinctive soft tissue tumor. 170 77

Two cases of TS associated with brain tumors had severe psychomotor retardation and early onset of long-term intractable convulsions, compared with cases without tumors. In one case, the tumor was partially cystic and progressed rapidly. Immunohistochemical studies of neuron specific enolase, glial fibrillary acidic protein and myelin basic protein revealed differences in positivity between cell types and between cases. These results suggested that the origin of the tumor cells could be variably differentiated cells.
 ...
PMID:Clinical and immunohistochemical studies of subependymal giant cell astrocytomas associated with tuberous sclerosis. 170 5

Because the data on the antigenic phenotype of mucoepidermoid carcinoma (MEC) are incomplete and somewhat disparate, 45 MECs were evaluated immunohistochemically for low- and high-molecular-weight keratins, vimentin, glial fibrillary acidic protein, smooth muscle actin, and S-100 protein. Tumors stained uniformly for keratins and, on occasion, focally for vimentin. Tumors were nonreactive with antibodies to glial fibrillary acidic protein and, with few exceptions, to muscle-specific actins and S-100 protein. Clear cell and papillary histologic variants were seen as potential diagnostic pitfalls. If used with hematoxylin-and-eosin-stained sections, limited potential is seen for this antibody panel in surgical pathology. Myoepithelial cell-associated antigens are expressed to a very limited extent in MECs.
 ...
PMID:Immunoprofile of mucoepidermoid carcinomas of minor salivary glands. 170 81

Medulloblastoma is one of the most common malignant brain tumors in childhood. These cells are immature bipotential cells that could differentiate into both neuronal and glial cells. The authors established two human medulloblastoma cell lines. One was derived from a 2-year-old girl with cerebellar tumor (designated as ONS-76) and another was from a 9-year-old girl with metastatic tumor in the right frontal lobe (ONS-81). Immunohistochemical studies showed that both cell lines possessed 145 and 200 kDa neurofilament proteins and neuron-specific enolase, without glial fibrillary acidic protein and S-100 protein. It was shown that interferon gamma could enhance or induce the expression of the major histocompatibility complex (MHC) antigens which play a major role in immune response. Also shown for the first time was the expression of MHC class II antigens on human medulloblastoma (ONS-76 and 81) with neuronal differentiation.
 ...
PMID:[Expression of major histocompatibility complex on human medulloblastoma cells]. 170 54


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