Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been proposed that angiogenesis inhibitors should be used for the treatment of diseases accompanied by an uncontrolled angiogenic response, particularly such disease occurring during progressive growth of solid tumors. In this study, the antiangiogenic effect of dexamethasone (DEX) was studied in a system using chorioallantoic membranes (CAM) of fertilized eggs and rabbit corneas. First, DEX was examined for its effect on embryonic angiogenesis using 4, 5 day old CAMs of chick embryos. After the shell and shell membrane was removed, an EV pellet with or without DEX was placed within a silicon ring. Two days later, the antiangiogenic response was evaluated by measuring the avascular zone of the CAM beneath the pellet. When the CAM showed an avascular zone of 3 mm or more in diameter, the response was scored as positive. DEX showed potent antiangiogenic activity and produced an avascular zone in 100% of CAMs at the highest dose tested. (250 ng/egg). Next, inhibitory effect of vascularization and tumor growth by local implant of DEX was observed in a rabbit cornea assay. An intra-corneal pocket extending to within 1 mm of the limbus was used to house a 1-mm3 piece of glioma. In the treatment group, DEX-containing EV pellet was inserted between the limbus and glioma. Ten days after the implantation of glioma and EV pellet, vascular response and tumor growth was evaluated. For morphologic studies, the excised corneas were fixed with formaldehyde fixative and sectioned for light microscopy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Inhibition of neovascularization and tumor growth by dexamethasone]. 137 88

We have used cytofluorometry to examine the formaldehyde sensitivity of the binding of a monoclonal antibody (MAB) to its epitope on glial fibrillary acidic protein in human malignant glioma cells in culture. When acetone-extracted whole cells or cytoskeletons, made by extracting with Triton in stabilizing buffer (Tsb), are fixed with formaldehyde, binding of the MAB Tp-GFAP1 to GFAP is abolished or greatly reduced. Fixation with the bifunctional protein crosslinking reagent dithiobis (succinimidyl propionate) (DTSP) has the same negative effect as formaldehyde. If cytoskeletons are further extracted with Tsb containing 250 mM ammonium sulfate (Thsb), fixation with formaldehyde or DTSP has reduced or no effect on the binding of Tp-GFAP1. The data are consistent with the hypothesis that aldehyde sensitivity of Tp-GFAP1 is caused by the crosslinking of a second protein to GFAP that blocks the binding of the MAB to its epitope. This putative blocking protein is part of the Triton-insoluble cytoskeleton, but it begins to be solubilized in 50 mM ammonium sulfate and it is largely removed in 250 mM ammonium sulfate (Thsb). SDS-PAGE shows that extraction with Thsb also removes a large number of proteins from the cytoskeleton, one of which could be the blocking protein. A second antibody to GFAP, designated Tp-GFAP3, was raised against cytoskeletons which had been fixed with DTSP and in which the epitope recognized by Tp-GFAP1 was presumably blocked. Tp-GFAP3 is not sensitive to fixation by either formaldehyde or DTSP.
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PMID:Formaldehyde sensitivity of a GFAP epitope, removed by extraction of the cytoskeleton with high salt. 244 10

Formalin-fixed and paraffin-embedded specimens of 24 human gliomas were examined histochemically with five lectins; concanavalin A (Con A), wheat germ agglutinin (WGA), Ricinus communis agglutinin 1 (RCA-1), peanut agglutinin (PNA), and Ulex europaeus agglutinin 1 (UEA-1). Although the staining intensity with lectins was variable, tumor cells in five astrocytomas, three oligodendrogliomas, six ependymomas, and one gliosarcoma, were generally positive for Con A, WGA, and RCA-1, and negative for PNA and UEA-1, whereas those in nine glioblastomas were usually positive for Con A and WGA and negative for RCA-1 and PNA as well as UEA-1. The malignancy in neoplastic astrocytes was correlated with the decrease in binding with lectins, especially RCA-1. Blood vessels, particularly the endothelial layers, in all gliomas were stained intensely with all lectins used. Macrophages showed two staining features with lectins; stippled and granular. The former macrophages were positive for Con A, WGA, RCA-1, and PNA, and negative for UEA-1, whereas the latter macrophages were positive for all lectins used. Thus, the staining characteristics with lectins of macrophages were different from those of any glioma cells and very useful for identification of macrophages in gliomas.
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PMID:Lectin histochemistry of human gliomas. 259 66

We have recently demonstrated that one of our monoclonal antibodies (MAB's) to glial fibrillary acidic protein (GFAP) recognizes an epitope on this molecule which is to a large degree blocked during fixation with formaldehyde or crosslinking with Dithiobis (Succinimidyl) Propionate (DTSP). This was shown to be due to the crossbinding of a single or a number of proteins to the GFAP and is not due to a change in the epitope on GFAP induced by the fixation itself. In an attempt to produce further MAB's capable of recognizing epitopes on the GFAP molecule available following formaldehyde fixation, we immunized BALB-C mice with cytoskeletal preparations of human glioma cells which contain GFAP where the blocking protein or proteins were crossbound by DTSP or formaldehyde to the GFAP. Following fusion of the spleen lymphocytes to Sp 2/0 myeloma cells we have cloned hybridomas which produce antibodies that recognize GFAP in formaldehyde fixed tissues. This method presents the antigen in its native "fixed" state for the mouse's immune system and avoids the production of MAB's which (although excellent for immunochemical studies) do not recognize any epitopes available on the molecule in question in formaldehyde fixed tissues. Antibodies so produced are of great interest in routine pathology where most tissues are still, unfortunately, undiscriminately fixed in formalin. The results also show that GFAP varies immunologically in different species (i.e. human v. rat/mouse) and confirm that the GFAP of the PNS is immunologically distinct and/or associated with different proteins from that found in the CNS.
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PMID:Monoclonal antibodies to GFAP epitopes available in formaldehyde fixed tissue. 354 74

Immunocytochemistry is routinely used to examine the occurrence and distribution of cytoskeletal proteins in cells, but the results are usually evaluated visually and subjectively. Little use has been made of the potential the method offers for quantitative work. Here we report on application of cytofluorometry to quantify binding of antibodies to the cytoskeleton of U-251 MG human malignant glioma cells in culture. The results show that cytofluorometry is a simple and reliable procedure for: (a) determining the optimal concentrations of primary and secondary antibodies and other labeling reagents; (b) evaluating the binding specificity of commercial secondary antisera; and (c) evaluating the effect of different preparatory procedures on preservation of and binding of antibodies to cytoskeletal structures. Experiments with a monoclonal antibody to tubulin show that preservation of tubulin is very sensitive to the preparatory procedures used. Maximum labeling of tubulin in intact cells was obtained when the cells were pre-fixed with formaldehyde before permeabilization with solvent. Maximum labeling of tubulin in Triton-extracted cytoskeletons was achieved by pre-fixing the cells with the bifunctional protein crosslinking reagent dithiobis (succinimidyl propionate), extracting with Triton in a microtubule-stabilizing buffer, and post-fixing with formaldehyde. GTP was not required to preserve tubulin in cytoskeletons.
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PMID:Use of cytofluorometry to evaluate binding of antibodies to the cytoskeleton of cultured cells. 368 Sep 31

A murine monoclonal antibody (monoclonal antibody 126) produced against cultured human neuroblastoma cells (LAN-1) was found to be specifically directed to a disialoganglioside (GD2) antigen preferentially expressed on both cell lines and tissues derived from melanoma and neuroblastoma. In enzyme-linked immunosorbent assays, monoclonal antibody 126 failed to react with leukemic and lymphoblastoid cells as well as with a variety of carcinoma and sarcoma cell lines. Immunohistological analysis by the immunoperoxidase technique revealed strong reactivity of monoclonal antibody 126 with frozen and formaldehyde-fixed neuroblastoma and melanoma tissues. Tissues from patients with glioma or with small cell cancer of the lung showed faint staining, whereas those from individuals with sarcoma, lymphoma, and a variety of other neoplasms proved to be negative. Sera of neuroblastoma patients showed significantly elevated GD2 levels compared to normal children (p less than 0.001) and children with other tumors (p less than 0.001) as determined by a quantitative competitive enzyme-linked immunosorbent assay. Furthermore, the GD2 serum level of one neuroblastoma patient, when followed serially, was found to correlate with progression of disease, suggesting the potential usefulness of this assay for the diagnosis and monitoring of neuroblastoma.
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PMID:Detection of ganglioside GD2 in tumor tissues and sera of neuroblastoma patients. 649 49

Formalin-fixed, paraffin-embedded surgical specimens from 140 primary human central nervous system tumors, including 51 meningiomas, 26 astrocytomas, 26 anaplastic astrocytomas, 9 glioblastomas, 1 gliosarcoma, 8 oligodendrogliomas, 5 ependymomas, 2 subependymomas, 9 medulloblastomas, and 3 paragangliomas, were immunostained using a streptavidin/peroxidase method and the PC10 monoclonal antibody, which recognizes an epitope on the proliferating cell nuclear antigen (PCNA). The following PCNA labeling index (LI) mean values were found for the above neoplasms: meningiomas, 3.80 +/- 7.35%; astrocytomas, 0.65 +/- 1.03%; anaplastic astrocytomas, 8.46 +/- 7.95%; glioblastomas, 10.26 +/- 11.21; gliosarcoma, 46.34%; oligodendrogliomas, 2.31 +/- 3.59%; ependymomas, 1.12 +/- 2.10%; medulloblastomas, 23.91 +/- 11.95%; and paragangliomas, 2.07 +/- 1.86%. Collectively, our findings indicate that while benign central nervous system tumors generally have low PCNA LI values, consistent over-expression of PCNA epitopes was noted in some examples, especially in a number of meningiomas. Among the malignant neuroectodermal tumors, medulloblastomas were found to have the highest PCNA LI values, corresponding to their histological grade of malignancy, and malignant glial tumors generally displayed significantly higher PCNA LI values, than their benign counterparts. Although in our study mean PCNA LI values seemed to reflect histological grading, large discrepancies were noted in all tumor groups. Our data, therefore, suggest than PCNA immunoreactivity can not be considered reliable for predicting the prognosis of the disease in individual cases.
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PMID:Proliferating cell nuclear antigen immunoreactivity in human central nervous system neoplasms. 768 17

During postnatal development, the formation of new blood vessels is possible only through angiogenesis. The initial growth of solid neoplasms, including childhood brain tumors, during the genetically determined stages of carcinogenesis, even at clinically undetectable sizes (a few mm3), depends upon the continuous formation of new blood capillaries [i.e. neovascularization (NV)/neoplasm-related angiogenesis (NRA)]. The generation of a malignant, invasive cellular immunophenotype (CIP) and distant metastases are also NRA-dependent processes. Endothelial cells undergo rapid proliferation during brain tumor related angiogenesis. Human endoglin (CD105/EDG), is a homodimeric cell surface component of the transforming growth factor-beta (TGF-beta) type I receptor complex and is also a proliferation-associated antigen (PAA) expressed at high density on endothelial cells. Formalin fixed, paraffin-wax embedded (3-5 microns thick), as well as frozen tissue sections (6 microns thick) of 62 childhood brain tumors [34 medulloblastomas (MEDs) and 28 astrocytomas (ASTRs)], were employed for the assessment of EDG expression. Both an indirect, four-step, alkaline phosphatase (AP) conjugated, biotin-streptavidin based (or a diamino-benzidine [DAB]) conjugated immunoperoxidase antigen detection technique were employed, utilizing the SN6h anti-EDG monoclonal antibody (DAKO Corp.). Another antigen detection method, based on the Histogold (Zymed) reaction was also employed using the same antibody on formalin fixed, paraffin-wax embedded tissues. Strong expression (A; +3 to +4) of EDG on endothelial cells and demonstrated in all 62 childhood brain tumor cases. The most striking feature of the newly formed tumor-related capillaries was the presence of a markedly enlarged perivascular space. Blood vessels in several normal human tissues (cortex, cerebellum, thymus, tonsil, spleen, lymph node, skin) used as control tissues contained significantly lower levels of EDG (B and mostly C; +/- to +), in accordance with the extremely slow turnover rate of normal endothelial cells. A close apposition between the capillaries and the adjacent parenchyma was also observed. Brain tumors, especially glioblastoma, are among the most vascularized human neoplasms, and thus are candidates for antiangiogenic therapy. VEGF/PF-R1 (flt-1) and VEGF/PF-R2 (flk-1) are formed de novo in a glioma progression-dependent manner. Further studies should substantiate the importance of EDG in the earliest possible detection, diagnosis and NRA inhibition-based treatment of mammalian solid neoplasms, especially childhood brain tumors.
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PMID:Upregulation of endoglin (CD105) expression during childhood brain tumor-related angiogenesis. Anti-angiogenic therapy. 967 60

Metastatic carcinoma, which is a common malignant tumor seen in the central nervous system is often difficult to distinguish from glioblastoma multiforme. In general, neoplastic cells maintain fidelity in the expression of parent cell intermediate filament and immunohistochemistry remains the mainstay in diagnosis. A panel consisting of GFAP (usually positive for astrocytic tumors) and cytokeratin (usually positive for metastatic carcinomas) is most commonly used for this purpose. However, co-expression of two or more classes of intermediate filament proteins by neoplasms is a widespread phenomenon and there are reports of glial neoplasms expressing keratin markers. Our aims and objectives were to analyse the expression of both cytokeratin and GFAP in different glial tumors and metastatic carcinomas. Cases were collected for a period of two years. All the cases were diagnosed as primary or metastatic intracranial tumors. Formalin-fixed paraffin-embedded thin sections were taken on egg-albumin coated slides and immunostaining with GFAP and polyclonal cytokeratin was done. Forty-five tumors were analysed, including 35 glial neoplasms and 10 metastatic carcinomas of which 7 of the 32 astrocytic neoplasms (22%) showed focal immunoreactivity with pancytokeratin. All of the glial tumors but none of the metastatic carcinomas were positive with GFAP. So our conclusion was that co-expression of GFAP and CK is a fairly common phenomenon, especially in case of undifferentiated and high grade gliomas and this must be kept in mind while differentiating these cases from metastatic carcinoma, as CK positivity does not rule out the diagnosis of a glial neoplasm. Further studies with an expanded panel of CK is most useful for this.
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PMID:Expression of cytokeratins in gliomas. 1788 12

Studies support involvement of the erbB/HER (human epidermal growth factor receptor) family, comprising the c-erbB-1/2/3/4 receptor proteins, in the tumourigenesis of human gliomas, raising their potential role in diagnostic and therapeutic approaches to these tumours. Reliable detection systems for these molecules in glioma tissue are therefore needed. Formalin-fixed and paraffin-embedded sections from twenty-one human glioblastomas were investigated by standard immunohistochemical procedures for expression of c-erbB-1/2/3/4 receptor proteins using commercial antibodies. All the antibodies used worked satisfactorily on paraffin-sections. For EGFR (epidermal growth factor receptor) two antibodies reactive against the external and internal domain were used. The first revealed positive immunoreactivity in 13 of 21 tumours (62 %), whereas all were positive with the latter. All glioblastomas were negative for the mutated variant of EGFR (i.e. EGFRvIII). Nine of 21 tumours (43 %) were immunoreactive for c-erbB-2, 19 of 20 tumours (95 %) for c-erbB-3, and 21 of 21 for c-erbB-4. Kaplan-Meier plots as a function of growth factor receptor expression did not show any significant association with survival among the glioblastoma patients. In conclusion, immunohistochemistry is well suited for detection of erb receptor proteins in glioblastoma tissue and demonstrated abundant and simultaneous immunoreactivity of these receptors.
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PMID:Coexpression of c-erbB 1-4 receptor proteins in human glioblastomas. An immunohistochemical study. 1798 95


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