Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have developed an in vivo method of measuring the blood-brain transfer constant (K) of iopamidol and the cerebral plasma volume (Vp) in brain tumors using a clinical X-ray CT scanner. In patient studies, Isovue 300 (iopamidol) was injected at a dosage of 1 ml/kg patient body weight. Serial CT scans of the tumor site and arterial blood samples from a radial artery were taken up to 48 min after injection. The leakage of iopamidol into the brain through the blood-brain barrier was modelled as an exchange process between two compartments, the intravascular plasma space and the tissue interstitial space. Using this model and the concentration measurements in blood plasma and tissue, quantitative estimates of K and Vp in brain tumors were obtained. In addition, distribution of the estimated values of K and Vp in tumors were displayed as false colour functional images overlaid on the conventional CT scan. In a study of twelve patients with anaplastic astrocytoma (n = 3), glioblastoma multiforme (n = 4) or metastases (n = 5) the mean K and Vp values in tumor were found to be 0.0273 +/- 0.0060 ml/min/g and 0.068 +/- 0.11 ml/g respectively. These values were significantly higher than those in grey or white matter in the contralateral 'normal' hemisphere (p less than 0.05). The functional images showed variations in K and Vp within the tumor which were difficult to perceive in the original contrast enhanced CT scans.
 ...
PMID:In vivo CT measurement of blood-brain transfer constant of iopamidol in human brain tumors. 133 51

Brain tumor growth results from the relative proportion of cells contained in three populations: a) cycling/proliferative; b) quiescent (GO)/static, and c) terminally differentiated/dying. The cycling compartment can be detected by the mouse monoclonal Ki-67 antibody, an available, rapid, safe, sensitive, and specific method for immunostaining of proliferative cells. We report the Ki-67 labeling index (LI) in 48 brain tumors. Malignant brain tumors have elevated LIs, ranging from 6.0% to 56.9%: anaplastic astrocytoma, 8.0 +/- 7.3; glioblastoma multiforme, 10.1 +/- 4.2; germinoma, 11.7; medulloblastoma, 13.1 +/- 6.6; metastases, 40.3 +/- 13.1. By contrast, slow-growing tumors showed lower values (P less than .001), approaching 1%: acoustic schwannoma, 0.4 +/- 0.6; pituitary adenoma, 1.3 +/- 1.9; meningioma, 1.2 +/- 1.2; low-grade astrocytoma, less than 1; pilocytic astrocytoma, 5.6. Human brain tumors can therefore be ranked according to the percentage of cycling cells with the acoustic schwannoma among the least proliferative and the metastatic carcinoma among the most proliferative. Within a given histotype, the Ki-67 LI may have prognostic and therapeutic implications for the individual patient. Already important for neuro-oncology research, the Ki-67 labeling index should be added to the armamentarium of the clinical neuropathologist to complement the standard histopathologic diagnosis with a cytokinetic analysis of cellular proliferation.
 ...
PMID:The cycling pool of cells within human brain tumors: in situ cytokinetics using the monoclonal antibody Ki-67. 164 10

Between January 1982 and June 1986, 60 consecutive patients with high-grade astrocytomas [39 glioblastoma multiforme (GBM), 21 anaplastic astrocytoma (AA)] were treated with radiation therapy after biopsy (13 patients) or resection (47 patients). Fifty-three patients were treated with limited-volume irradiation, and seven patients received whole-brain irradiation. The mean tumor dose was 65.4 Gy. In 35 patients, chemotherapy was given as part of their initial treatment. The 1- and 2-year survivals for GBM patients were 40 and 14%, respectively. Survival figures for AA patients were 76 and 52% at 1 and 2 years, respectively. The progression-free rate at 1 year was 13% in GBM and 29% in AA patients. Thirty-four of 48 patients who received limited-volume irradiation had evidence of progression on postirradiation CT scans. Six patients (3 GBM, 3 AA) had evidence of a new intracranial metastatic site on CT scan. In three patients the metastasis was within the previously irradiated volume, and in the other three patients, it was outside this volume. All six had evidence of progression of their primary tumor at the original location on CT scan prior to the discovery of the metastatic site. Twenty-one patients (15 GBM, 6 AA) had at least one postirradiation reoperation for a recurrent mass. Nineteen patients had recurrent tumors in the primary site, and two patients had necrosis but no tumor. Patients who received limited-volume irradiation for high-grade astrocytomas achieved the same survival results as patients treated previously with whole brain irradiation. New intracranial metastases did not influence the outcome, since these were always antedated by tumor progression at the primary site.
 ...
PMID:Outcome and patterns of failure following limited-volume irradiation for malignant astrocytomas. 185 73

We evaluated 17 children with primary intracranial neoplasms for subarachnoid metastatic disease (SAMD) using myelography with computed tomographic follow-up (Myelo + CT) and cerebrospinal fluid (CSF) histopathologic examination, as well as magnetic resonance imaging with gadolinium DTPA (MRI + Gd), between December 1988 and December 1989. There were 12 boys, and the median age was 5.7 years (range, 0.8 to 21.8 years). Tumor histology included 8 primitive neuroectodermal tumors (PNETs), 3 ependymomas, 2 low-grade astrocytomas, 1 anaplastic astrocytoma, 1 glioblastoma multiforme, 1 atypical rhabdoid tumor, and 1 malignant fibrous histiocytoma. Thirteen tumors originated in the posterior fossa, 2 were supratentorial, and 2 were in the spinal cord. The median interval between the 2 diagnostic tests was 2 days. MRI + Gd was positive in 11 (65%), Myelo + CT in 8 (47%), and CSF in 5 (29%) cases. MRI + Gd was superior in delineating spinal cord nodules and "sugar coating" whereas Myelo + CT more readily revealed nerve root sleeve filling defects. There was no case in which Myelo + CT was positive that MRI + Gd did not reveal SAMD. MRI + Gd is a safe, noninvasive test that should be used as the initial imaging modality for the presence of SAMD.
 ...
PMID:Comparison of myelography with CT follow-up versus gadolinium MRI for subarachnoid metastatic disease in children. 198 95

Between June 1987 and June 1989, 29 recurrent malignant gliomas or recurrent solitary brain metastases in 28 patients were treated in a Phase I study of interstitial irradiation and hyperthermia. Patient age ranged from 18 to 65 years, and the Karnofsky Performance Status scores ranged from 40 to 90%. There were 13 glioblastomas, 10 anaplastic astrocytomas, 3 melanomas, and 3 adenocarcinomas. Catheters were implanted stereotactically after computed tomography-based preplanning. Hyperthermia was administered before and after brachytherapy, using one to six 2450- or 915-MHz helical coil microwave antennas and one to three multisensor fiberoptic thermometry probes. The goal was to heat as much of the tumor as possible to 42.5 degrees C for 30 minutes. Within 30 minutes after the first hyperthermia treatment, implant catheters were afterloaded with high-activity iodine-125 seeds delivering tumor doses of 32.6 to 61.0 Gy. Most patients had no sensation of heating. Complications included seizures in 5 patients, reversible neurological changes in 9 patients, a scalp burn in 1, and infections in 3. Of 28 evaluable 2-month follow-up scans, 11 showed definite improvement in the radiological appearance of the tumor, 4 were slightly improved, 7 were stable, and 6 showed tumor progression. Ten patients underwent reoperation for persistent tumor and/or necrosis. Eleven of 28 patients are alive 40 to 97 weeks after treatment. Thirteen patients died of a brain tumor, 2 died of extracranial melanoma metastases, 1 died of new brain melanoma metastases, and 1 died of a pulmonary embolus. The median survival was 55 weeks overall. Median survival has not yet been reached for the anaplastic astrocytoma subgroup. We conclude that interstitial brain hyperthermia using helical coil microwave antennas is technically feasible. The level of toxicity is acceptable, and the computed tomographic response rate is encouraging.
 ...
PMID:Interstitial irradiation and hyperthermia for the treatment of recurrent malignant brain tumors. 199 88

During the 30 year period from 1957 to 1986, 42 patients with primary tumors arising from the spinal cord or cauda equina received postoperative irradiation at the University of California, San Francisco. Twenty-one patients had ependymomas: 18 were localized to one site, and 3 diffusely involved the cord. There were 12 patients with low grade astrocytomas and 3 with highly anaplastic astrocytoma or glioblastoma multiforme. All astrocytomas were localized at presentation. In 6 cases tissue was insufficient to permit a histologic diagnosis. Thirty-nine patients (93%) received total radiation doses ranging between 45.0-54.7 Gy using standard fractionation. The 10-year actuarial disease-specific survival rate for patients with localized ependymoma was 93%; 33% of these tumors recurred locally. The corresponding rate for diffuse ependymomas was 50%; the spinal disease was controlled in all 3 patients, but one developed a cerebral metastasis despite prophylactic cranial irradiation. Low-grade astrocytoma patients had a 10-year actuarial disease-specific survival rate of 91%, with 33% of these tumors recurring locally. No patient with highly anaplastic astrocytoma or glioblastoma multiforme survived longer than 8 months; all of these tumors recurred locally, and two of the three also developed diffuse craniospinal axis metastases. Local recurrence for ependymoma was delayed as long as 12 years following treatment, while all but one astrocytoma failure occurred within 3 years of treatment. No significant dose-response relationship with respect to local control was noted for either localized ependymomas or low grade astrocytomas. One patient developed radiation myelitis after receiving 50.4 Gy with standard fractionation. These results indicate that patients who undergo postoperative irradiation for low grade spinal astrocytomas and localized spinal ependymomas achieve excellent survival. However, despite treatment with total radiation doses taken to the practical limit of spinal cord tolerance, local failure remains common.
 ...
PMID:Postoperative radiotherapy of primary spinal cord tumors. 254 94

Diffuse astrocytomas of the cerebrum, cerebellum, brain stem, and spinal cord are classified into three groups according to the degree of tumor anaplasia. These groups are the astrocytoma, anaplastic astrocytoma, and glioblastoma multiforme. Juvenile pilocytic astrocytomas have a better prognosis and are clinically and biologically distinct from the diffuse, fibrillary astrocytomas. The prognosis of astrocytomas depends not only on histologic characteristics, but also age of the patient, location of the tumor, and extent of surgical resection. The pattern of invasion into surrounding brain distinguishes gliomas from metastatic carcinomas and sarcomas. Topographic correlations have shown that malignant gliomas may invade the brain for distances of up to several centimeters from the enhancing rim seen on CT scan. However, the junction between glioblastoma and adjacent brain may also be fairly abrupt, with a peripheral margin of less than 1 mm. Recurrent glioblastomas are more widely invasive and often extend into areas that appear normal on CT scan. The optimal site for tumor biopsy corresponds to areas of contrast enhancement. Primitive neuroepithelial tumors are malignant neoplasms with a poor prognosis. They tend to recur locally and metastasize throughout the neuraxis via the CSF. It remains controversial whether these tumors should be classified as a single entity with the potential for differentiation along different cell lines, or whether the categories of neuroblastoma, spongioblastoma, ependymoblastoma, pineoblastoma, and medulloblastoma should be retained as specific entities. The medulloblastoma is the most common of these neoplasms, its clinicopathologic features are well characterized, and the current 5-year survivals of 50 to 60 per cent are better than for other "primitive" neoplasms. Glial fibrillary acidic protein is a specific marker for immature, reactive, and neoplastic astrocytes and ependymal cells. Although the absence of GFAP in a neoplasm does not exclude an astrocytic origin, the presence of GFAP indicates astrocytic or ependymal differentiation. This has important diagnostic applications. The expression of GFAP is used to distinguish astrocytic neoplasms from epithelial or mesenchymal tumors that may on occasion mimic a glioma. The detection of GFAP is also useful in the investigation of tumor histogenesis and differentiation both in vivo and in vitro. Although meningiomas exhibit a wide variety of histologic patterns, most tumors exhibit similar biologic and clinical behavior regardless of the histologic subtype.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Pathologic analysis of primary brain tumors. 300 88

Extraneural metastases of brainstem gliomas are exceedingly rare. Only four such cases are reported in the literature. We report on a case of a 3-year-old girl with an anaplastic astrocytoma of the brainstem which metastasized to the cervical lymph nodes.
 ...
PMID:Extraneural metastasis of a brainstem astrocytoma in a child: clinicopathological report. 320 82

The cell-surface receptor for hyaluronic acid, CD44, is expressed by both normal and malignant cells. Numerous CD44 isoforms have recently been identified that are derived by alternative ribonucleic acid splicing. The expression of some CD44 isoforms has been shown to be involved in tumor progression and metastatic spread in a rat carcinoma model and in human carcinomas. In the present study, CD44 isoform expression was evaluated by reverse transcriptase-polymerase chain reaction (PCR) analysis in frozen sections derived from three samples of normal brain tissue and from 40 brain tumors, including samples of glioblastoma multiforme, anaplastic astrocytoma, low-grade astrocytoma, cerebral primitive neuroectodermal tumor, medulloblastoma, metastatic colon carcinoma, and metastatic melanoma. Normal brain tissue adjacent to the tumors was also examined in 14 of 18 glioblastomas. In all normal brain and tumor samples, with the exception of metastases from colon carcinoma, PCR analysis demonstrated one prominent product that corresponded to the CD44H hematopoietic form of CD44. Metastases from colon carcinoma demonstrated two prominent PCR amplification products corresponding to CD44H and CD44R1. These results suggest that CD44H is the predominant isoform of this protein in normal human brain tissue and in human neuroectodermal tumors of varying degrees of malignancy. The ability of CD44H to mediate tumor cell motility and invasiveness (in contrast to CD44R1) suggests that the CD44 alternative splicing pattern of neuroectoderm-derived tumors may enhance their local biological aggressiveness and intracerebral spread. The lack of expression of larger molecular weight CD44 variants by primary brain tumors may also partially explain why these tumors rarely metastasize to distant sites.
 ...
PMID:Alternative RNA splicing of the hyaluronic acid receptor CD44 in the normal human brain and in brain tumors. 753 36

Degradation of the extracellular matrix is a prerequisite for acquisition of the invasive phenotype. Several proteinases released by invading tumor cells appear to participate in the focal degradation of extracellular matrix proteins. Using an enzyme-linked immunosorbent assay, enzymatic assays, Western and Northern blotting techniques, we determined whether increased levels of the cysteine protease cathepsin B correlated with the progression and invasion of human gliomas. The amount of cathepsin B activity and protein content were highest in glioblastomas, lower in anaplastic astrocytomas and lowest in normal brain tissue and low-grade gliomas. There were significantly higher amounts of M(r) 25,000 and 26,000 bands in glioblastoma and anaplastic astrocytoma than in normal brain and low-grade glioma tissue extracts as determined by Western blotting with anti-cathepsin antibodies. In addition, cathepsin B transcripts were overexpressed in anaplastic astrocytoma (about two- to three-fold), in glioblastoma (about eight- to 10-fold), compared with normal brain tissue and low-grade glioma. Immunohistochemical staining for cathepsin B showed intense immunoreactivity in tumor and endothelial cells of glioblastomas and anaplastic astrocytomas but only weak immunoreactivity in low-grade glioma and normal brain tissues. Therefore, we conclude that cathepsin B expression is greatest in highly malignant astrocytomas, especially in glioblastomas, and is correlated with the malignant progression of astrocytomas.
Clin Exp Metastasis 1995 Jan
PMID:Overexpression and localization of cathepsin B during the progression of human gliomas. 782 Sep 56


1 2 3 4 Next >>