Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017636 (glioblastoma)
 18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A series of 16 cases of intracerebral hemorrhage associated with brain tumors are described. The literature is reviewed and the incidence of these cases is reported to be low, but we had clinically encountered these cases more commonly than reported, since CT was introduced to the neurosurgical field as a diagnostic aid. The presenting symptoms were those of spontaneous intracerebral hemorrhage or brain tumor. The intracerebral hemorrhage associated with brain tumor may mask the cause of bleeding and confuse the diagnosis. The majority of the tumor causing the intracerebral hemorrhage are highly malignant as glioblastoma or metastatic brain tumor, but there are some benign tumors such as pituitary adenoma, hemangioblastoma, benign astrocytoma and meningioma, which would have good survival rates if discovered early. The mechanisms of massive hemorrhage with brain tumor are not clear. From pathological findings of our cases and other reports, the mechanism seems to be due to the vascular endothelial proliferation with subsequent obliteration of the lung of the vessel. Thin walled, poorly formed vessels in tumor may also become distorted with growth of the tumor and these may easily rupture and bleed. Necrosis with subsequent loss of vessel support may be a factor in production of hemorrhage. Radiation therapy may be a predisposing factor. Children are rarely involved in these cases. The prognosis in the majority of cases would seen to be poor, since the majority of the tumor are highly malignant and most such patients are seen by the neurosurgeon some time after the hemorrhage has accomplished its fatal mischief.
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PMID:[Intracerebral hemorrhage in brain tumors (author's transl)]. 744 24

Three independent methods were used to quantify the therapeutic effect on peritumoral brain edema with respect to different forms of treatment (dexamethasone, furosemide, and their combination with different dosages and different periods of treatment). 1. The neurological deficit evaluated by frequency distribution analysis showed an improvement in nearly all cases. In a few cases the initial improvement was followed by a secondary deterioration. The various symptoms showed significant differences in regression with regard to the extent of the reduced deficit as well as the time dependence. 2. With a certain delay (compared to item 1), diminution of brain edema was detected by CT follow-up. The effect of dexamethasone and the combination with furosemide differed depending on the nature of the brain tumor. 3. Compared to the untreated patients, the water content was reduced by nearly 3% following dexamethasone treatment 4 x 4 mg for 4 to 6 days. Following dexamethasone/furosemide therapy for 4 to 6 days, it was reduced by about 4.5%. The result of long-term therapy with dexamethasone alone was similar. The sodium content changed parallel to the water content. Dexamethasone and dexamethasone/furosemide was most effective in patients with glioblastoma, where the water content decreased by nearly 6%. The data presented suggest that preoperative antiedema treatment with dexamethasone is necessary for several days or a few weeks in some cases. The period of treatment can be reduced significantly by dexamethasone/furosemide or extremely high doses of dexamethasone. On the other hand, the results of follow-up scoring of the neurological situation show that the optimal time of pretreatment must be limited with respect to the individual case. The therapeutic results presented allow inferences to be made concerning pathophysiology of the resolution of brain edema.
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PMID:Clinical, chemical, and CT evaluation of short-term and long-term antiedema therapy with dexamethasone and diuretics. 745 58

Antineoplaston (Ap), a new antitumor agent, was clinically tested for effects on malignant brain tumors. The materials were 3 cases of glioblastoma (G,B), 2 cases of anaplastic astrocytoma, 1 case of pontine glioma, 2 cases of metastatic brain tumor and 1 case of medulloblastoma. All patients underwent radiochemotherapy and surgical resection of the tumors except the cases of pontine glioma, metastatic brain tumor and anaplastic astrocytoma. For gliomas, radiochemotherapy was used with Hu-IFN-beta. Ap was administered at a dose of 7-10 g/day in combination with remission maintenance therapy of gliomas. Complete response was obtained in one anaplastic astrocytoma. Partial response was obtained in 2 cases, a pontine glioma and a metastatic brain tumor. No change was observed in 2 cases, an anaplastic astrocytoma and a multiple brain metastasis. Progression of the disease was observed in 4 cases, 3 glioblastomas and 1 medulloblastoma, which showed continuous increase in tumor size. The effects of Ap on malignant brain tumors were considered due to synergy, since it was administered with other drugs and acceleration of tumor cellular differentiation. Ap is useful as an approach to remission maintenance therapy for brain tumors.
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PMID:The effect of Antineoplaston, a new antitumor agent on malignant brain tumors. 747 50

The plexiform lesion in primary pulmonary hypertension is a glomeruloid structure forming channels in branches of the pulmonary artery. These lesions have been considered an abnormal growth of modified smooth muscle cells. We present immunohistochemical evidence in 10 cases of plexogenic pulmonary hypertension that the plexiform channels and the concentric obliterative arteriopathy associated with these channels represent abnormal growth of factor VIII-related antigen-positive endothelial cells. In addition, these cells strongly expressed vimentin, a growth- and differentiation-related intermediate filament. Morphologically and immunohistochemically, the lesions resembled the neovascularization associated with the brain tumor glioblastoma multiform. Furthermore, we noted an exclusively perivascular inflammatory cell infiltrate (but no vasculitis) in seven of the 10 cases with plexogenic arteriopathy composed of T cells, B cells, and macrophages. Our findings indicate that the plexiform lesion may result from a deregulated growth of endothelial cells. The presence of perivascular inflammatory cells suggested that cytokines and growth factors may further influence the development of the plexiform lesion.
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PMID:Exuberant endothelial cell growth and elements of inflammation are present in plexiform lesions of pulmonary hypertension. 1143 86

In primary malignant brain tumors increased vascularity and marked edema strongly suggest a possible role of the vascular endothelial growth factor/vascular permeability factor (VEGF/VPF). This was confirmed by earlier in situ hybridization studies, by analysis of the expression of the mitogen in different subsets of glioblastoma cells, and by the fact that the VEGF/VPF receptor flt-1 (fms-like tyrosine kinase) is up-regulated in tumor cells in vivo. To assess and quantify the expression of the VEGF/VPF gene and of the receptor gene, 26 surgical specimens of brain tumor tissue from 24 patients were analyzed. In most malignant gliomas, the expression level of the VEGF/VPF gene is elevated and can be increased up to 20- to 50-fold in comparison with low-grade tumors. Using polymerase chain reaction-based amplification, it could be shown that the messenger RNAs of three different VEGF/VPF forms are synthesized in tumor tissue samples. Northern blot studies revealed that in some samples a significant expression of the gene coding for placenta growth factor, a growth factor closely related to VEGF/VPF, was observed. In addition, using a radioreceptor assay it was possible to detect high VEGF/VPF-like activity in the cyst fluids of brain tumors, indicating the accumulation of the mitogen and permeability factor in brain tumor cysts. Further investigations revealed that astrocytoma and glioblastoma cells in culture express the VEGF/VPF gene and secrete the VEGF/VPF protein, whereas gene expression of the two known VEGF/VPF receptors, kinase insert domain-containing receptor and flt-1, could not be detected. These data support previous reports, which stated that VEGF/VPF acts as a paracrine growth and permeability factor in brain tumors and may contribute to tumor growth by initiating tumor angiogenesis.
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PMID:Detection and quantification of vascular endothelial growth factor/vascular permeability factor in brain tumor tissue and cyst fluid: the key to angiogenesis? 752 59

The antitumor activity of the DNA fraction extracted from Mycobacterium bovis BCG (MY-1) for glioblastoma was investigated in the experimentally produced brain tumor in rats. The tumor-bearing rats were given intralesional injection of 1 mg of MY-1 twice a week for three weeks, and were sacrificed for comparison with those of control rats. The main macroscopic features of the tumors treated with serial injections of MY-1 were cystic and destructive structures, which were histologically characterized by multiple microcysts containing macrophages. Furthermore, infiltration of leukocytes as well as the perivascular cuffing in the marginal area was observed. These findings suggested that the serial injections of MY-1 into the brain tumor have the therapeutic potential for glioblastoma.
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PMID:The antitumor activity of the DNA fraction from Mycobacterium bovis BCG (MY-1) for glioblastoma. 754 29

O6-methylguanine-DNA methyltransferase (MGMT) activity was measured in 68 tissue samples taken from brain. A wide range in activity among samples was observed, with all nonmalignant samples showing transferase activity (Mer+) but approximately 15% of WHO grade II low-grade astrocytomas and WHO grade IV glioblastoma multiformes lacking activity (Mer-). On average, astrocytomas and glioblastomas showed less transferase activity than either nonmalignant tissue or meningiomas. Monoclonal antibodies specific for MGMT showed both cytoplasmic and nuclear staining of Mer+ brain tumor cells in culture but no staining of Mer- cells in culture. In pathology specimens from anaplastic astrocytomas, glioblastoma multiformes, and meningiomas, antibody staining revealed both cytoplasmic and nuclear MGMT, while one sample showed little or no MGMT-specific staining. These results help explain why nitrosoureas have been among the most successful agents in treatment of brain tumors and indicate the subcellular localization for the repair activity, which may be relevant to nitrosourea resistance.
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PMID:O6-methylguanine-DNA methyltransferase in human brain tumors detected by activity assay and monoclonal antibodies. 754 44

In 1955, Collins made the observation that tumor recurrence in children with Wilms' tumor was correlated with the child's age plus 9 months. This concept of a period of risk for recurrence was later applied to a variety of tumors in children and became known as Collins' Law (CL). The law has been a successful predictor of survival for some children with neural tumors within the central nervous system and a poor predictor for others. We tested Collins' concept of a period of risk for recurrence and extended it to survival for 14 childhood neural tumors described in the Childhood Brain Tumor Consortium (CBTC) database. The CBTC data describe clinical, surgical, and histological details (over a 49-year period in 10 institutions) from 3921 patients under the age of 21 years at the time of their first surgical procedure for a brain tumor. CL was considered to be a good predictor of survival if fewer than 10% of patients who die survive beyond the expiration of the period of risk for that child. We found that CL applied to tumors such as anaplastic astrocytoma, glioblastoma, pineoblastoma, medulloblastoma or "primitive neuroectodermal tumor," teratoma, and germinoma, as well as ependymoma, papilloma, and tumors that could not be classified; it had no predictive value in craniopharyngioma, oligodendroglioma, or plain, fibrillary, pilocytic, or protoplasmic astrocytoma. We had sufficient follow-up data to determine adherence to CL when the child's age at diagnosis was less than 8 years; it is likely that CL applies to older children with these tumors, but we did not have the data to show this unequivocally.
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PMID:The applicability of Collins' Law to childhood brain tumors and its usefulness as a predictor of survival. 764 86

We have recently shown that vascular endothelial growth factor (VEGF) is produced by human malignant glioma cells and acts on tumor endothelial cells, which express VEGF receptors, suggesting that VEGF is a regulator of tumor angiogenesis. To investigate the feasibility of antiangiogenic brain tumor therapy, we developed an intracerebral (i.c.) rat glioma model. We used two transplantable rat glioma cells lines, C6 and GS-9L, to analyze VEGF regulation in vitro and expression of VEGF and its high affinity tyrosine kinase receptors, flt-1 and flk-1, in vivo. Glioma cells were transplanted i.c. or s.c. into syngeneic rats. C6 gliomas exhibit morphological characteristics of human glioblastoma multiforme such as necroses with palisading cells. Immunocytochemistry with von Willebrand factor showed that C6 gliomas are highly vascularized and therefore show another prominent feature of human glioblastoma. GS-9L gliosarcomas were less vascularized. In situ hybridization showed that VEGF is expressed in vivo in rat glioma cells which reside along necrotic areas and therefore closely mimicks the expression pattern of VEGF observed in human glioblastoma. flt-1 and flk-1 are specifically expressed in endothelial cells in the tumor and at the border between tumor and normal brain but are absent from endothelial cells in the normal brain proper. The action of VEGF may therefore be restricted to tumor endothelium. Upregulation of VEGF, but not acid fibroblast growth factor, basic fibroblast growth factor, and platelet-derived growth factor B messenger RNA was observed in hypoxic C6 and GS-9L cells in vitro. These observations are consistent with a role for VEGF in tumor- and hypoxia-induced angiogenesis. Since the expression pattern of VEGF and its receptors in rat glioma appears to be indistinguishable from human glioblastoma multiforme, this model provides an excellent tool to study anti-angiogenic therapy.
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PMID:Up-regulation of vascular endothelial growth factor and its cognate receptors in a rat glioma model of tumor angiogenesis. 769 95

The cellular receptor for urokinase-type plasminogen activator (uPAR) in glioblastoma cell lines has been identified and found to be similar to the uPAR expressed by other tumor cell lines. Increased levels of uPAR have been found in primary malignant brain tumor tissues, especially highly malignant glioblastoma, and, to a lesser degree, in malignant astrocytomas, suggesting that this receptor might be involved in efficient activation of pro-uPA and confinement of uPA activity on the cell surface of invading brain tumors. The cell surface uPARs in gliomas could constitute an optimum environment for the generation and activity of plasmin, which is known to play a crucial role in the dissolution of the extracellular matrix during tumor cell invasion. In situ hybridization studies have shown that uPAR mRNA is expressed abundantly in tumor cells and is consistently present at the invasive edges of malignant gliomas. These results imply that uPAR is involved in plasmin-catalyzed proteolysis during glioma invasion and that interference with the uPA:uPAR interactions could constitute a novel approach for developing therapeutic strategies to counteract invasion of brain tumors.
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PMID:Proteolysis and invasiveness of brain tumors: role of urokinase-type plasminogen activator receptor. 774 67


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