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T B Mapstone

Publications and source records attributed to T B Mapstone.

33 records · Page 2Linked to original sources
PubMed1991

Intracranial tumor in infants: characteristics, management, and outcome of a contemporary series.

Since 1980, 22 patients less than 2 years of age have been treated for intracranial tumors at our institution. The most common presentation was elevated intracranial pressure associated with ventriculomegaly (73%). The diagnosis was made by computed tomography or magnetic resonance imaging and confirmed surgically in every case. In 68% of cases, the tumor involved midline structures in the central nervous system. Tumors were infratentorial in 29% of patients less than 1 year of age and in 60% of those more than 1 year of age. Most tumors were either primitive neuroectodermal tumors (41%, 7 of 9 located in midline posterior fossa structures) or astrocytomas (27%, 5 of 6 located in the hypothalamus, chiasm, or optic nerve). Twenty patients had gross or subtotal tumor resection. Surgical mortality and neurological morbidity were 10% and 5%, respectively. Of 5 patients who underwent a second operation for tumor recurrence, 3 demonstrated a change in the pathological features of the tumor from those of the original diagnosis. Of 10 surgical survivors with malignant tumors, 8 received chemotherapy and 5 radiation therapy. Radiation was not administered before 1 year of age. The overall 1-year survival was 70%, and 2-year survival was 58%. Two-year survival for benign and malignant tumors was not significantly different. We think that the interdisciplinary efforts directed toward the treatment of these tumors has improved survival and that all children should be offered entry to a research protocol and aggressive treatment.

Brain Neoplasms↗
PubMed1990

Ventral brain-stem compression from a subarachnoid ependymal cyst.

A case of ventral brain-stem compression by a congenital subarachnoid ependymal cyst in an infant is presented. Marsupialization of the cyst provided effective decompression and clinical improvement. Immunohistochemical staining demonstrated the glial nature of the epithelium. The fact that these cysts may be congenital, as demonstrated here, supports the hypothesis that they arise from glial elements that have been displaced during development.

Brain Diseases↗
PubMed1989

Major structural alterations of the c-sis gene are not observed in a series of tumors of the human central nervous system.

Expression of the c-sis oncogene, the gene encoding the B chain of platelet-derived growth factor (PDGF), may be related to initiation and/or progression of glial cell tumorigenesis by PDGF-mediated autocrine growth stimulation. As the mechanism for activation of expression of the c-sis gene in gliomas is not known, we searched for possible structural alterations of c-sis DNA in these tumors. Genomic Southern blots of DNA from 7 different cultured human glioblastoma cell lines and 15 different solid human brain tumors revealed no significant change in either the gross structure or the copy number of the c-sis gene in tumor cells vs. control cells. Activation of glioma c-sis gene expression is therefore not the result of a gross rearrangement or amplification of the c-sis gene. Expression of c-sis mRNA was detected in all of 12 different solid human brain tumors, 11 of which were of glial cell origin. However, in tissue adjacent to 5 different tumors, approximately the same level of c-sis mRNA was seen.

Brain Neoplasms↗
PubMed1988

Pituitary stalk agenesis: magnetic resonance imaging of 'ectopic posterior lobe' with surgical correlation.

A patient with anterior pituitary deficiencies, without diabetes insipidus, was found to have a retrochiasmatic mass in association with a large middle fossa cyst on CT and MRI scans, and no tissue in the sella ('empty sella'). At surgery, the pituitary stalk was absent. The retrochiasmatic mass was biopsied and shown to be consistent with pituitary stalk. Recent descriptions of MR visualization of an 'ectopic' posterior pituitary lobe are discussed in relation to this case of agenesis of the pituitary stalk and posterior lobe.

Adolescent↗
PubMed1984

Relationship of CSF shunting and IQ in children with myelomeningocele: a retrospective analysis.

This paper reviews 75 infants with myelomeningocele treated either at birth or from an early age at Rainbow Babies and Children's Hospital, for whom complete records and psychometric testing (IQ) are available (including complete summaries from referring hospitals). Three groups are compared: (1) infants without complications who were shunted for hydrocephalus (n = 41); (2) infants with complications who were shunted (n = 16), and (3) infants who were not shunted (n = 18). Complications were defined as ventriculitis (positive CSF cultures with elevated protein, depressed glucose and inflammatory cells), anoxia, poorly controlled hydrocephalus or other CNS anomalies such as porencephaly. The mean IQ of infants who were not shunted was 104, of those shunted without complications it was 91, and of those shunted who had complications it was 70. These IQ differences were significant at p less than 0.01, and were not explained by differences in spinal lesion levels.

Arnold-Chiari Malformation↗
PubMed1983

Quadriplegia secondary to hematoma after lateral C-1, C-2 puncture in a leukemic child.

Epidural, subdural, and intramedullary hemorrhage developed after lateral cervical (C-1, C-2) puncture in a thrombocytopenic patient with meningeal leukemia and increased intracranial pressure. Aggressive platelet support before the procedure did not prevent the hemorrhagic complication. Complete recovery from total motor paralysis with respiratory arrest followed immediate surgical decompression and continuing platelet support. The potential dangers of otherwise minor procedures in compromised patients are reiterated. Neurological recovery as seen here argues for immediate surgical intervention with the development of such potentially life-threatening events.

Adolescent↗
PubMed1981

Cavum septi pellucidi as a cause of shunt dysfunction.

Cavum septi pellucidi and cavum vergae are generally asymptomatic fluid collections between the leaves of the septum pellucidum and are present in approximately 15% of adult brains. There are occasional reported cases of symptomatic cysts arising in this area. This paper reports a case in which a cavum septi pellucidi was a cause of shunt malfunction. On an air ventriculogram this condition was initially confused with a subdural collection.

Brain Diseases↗
PubMed1981

Anterior sacral meningocele.

A case of anterior sacral meningocele is presented emphasizing early diagnosis based on recurring functional complaints and employing appropriate radiological studies. The appropriate use of computerized tomography (CT) scanning and the proper surgical management utilizing laminectomy and obliteration of the communicating channel of the meningocele are discussed.

Child↗
PubMed1976

Early events during substrate adhesion of normal and virus-transformed mouse fibroblasts.

The relationship between attachment of Balb/c3T3 cells and their SV40 transformants to glass or plastic substrates and deposition of substrate-attached material (SAM-proteoglycans implicated in substrate adhesion) has been examined very early after inoculation of cells subcultured with ethylenebis (oxyethylenenitrilo) tetra-acetic acid (EGTA). The metabolic inhibitors cycloheximide and colchicine minimally affected the kinetics or short-term stability of attachment of cells or deposition of SAM. SAM deposition on to the substrate began immediately after inoculation of cells and was maximal prior to the highest cell attachment level (30-40 min after inoculation). At 4 degrees C, there was no attachment of cells to the substrate and no deposition of leucine- or glucosamine-radiolabelled SAM on to the substrate. 3T3 cells deposited SAM to a maximal level earlier during the attachment process than SV40-transformed cells. SVT2 cells deposited much smaller amounts of SAM (measured on a per-cell basis) to 3T3 SAM-coated substrates during attachment processes, whereas 3T3 cells and concanavalin A (con A) revertant variants of SVT2 cells, which have regained density-dependent inhibition of growth, deposited identical amounts of SAM (per-cell) on untreated or SAM-coated substrates. Serial attachment experiments with SVT2 cells indicated that all SVT2 cells reduced their deposition amounts on SAM-coated substrates, rather than there being an ability of a small proportion of cells to attach preferentially to SAM-coated substrates while being unable to deposit SAM themselves. The data are consistent with the presence of a sizeable pool of SAM-like proteoglycans being present on the surface of EGTA-removed cells whose deposition may be a requirement for, but may not necessarily be sufficient for, stable adhesion of cells to the substrate.

Cell Adhesion↗
PubMedDate not supplied

Expression of glial fibrillary acidic protein, vimentin, fibronectin, and N-myc oncoprotein in primary human brain tumor cell explants.

Cultured cells of explants from 23 human gliomas (seven astrocytomas, eleven anaplastic astrocytomas, three ependymal tumors and two medulloblastomas) were studied to examine cell morphology and expression of glial fibrillary acidic protein (GFAP), vimentin, fibronectin, and N-myc oncoprotein. The most common antigenic phenotype consisted of cells that were GFAP-positive and fibronectin-positive. Both low and high grade astrocytomas retained GFAP expression after several passages in vitro. The establishment of glial tumors in vitro may not necessarily result in loss of GFAP expression early in passage nor is expression of GFAP and fibronectin mutually exclusive. N-myc oncoprotein was seen in only two specimens, one anaplastic astrocytoma and one ependymoma.

Astrocytoma↗
PubMedDate not supplied

TPA-mediated regulation of osteopontin in human malignant glioma cells.

Malignant gliomas are the most common primary intracranial neoplasms in adults and are largely refractory to post-surgical therapy despite intensive therapeutic efforts. Using a number of different brain tumor-derived cell lines we have demonstrated that the mRNA for osteopontin (OPN), which is substantially over-expressed by some tumors in comparison with normal tissues, is preferentially expressed in high grade and metastatic brain tumors compared to low grade brain tumors. One glioma-derived cell line, U105MG, which does not express significant amounts of OPN mRNA, could be induced dose-dependently by the tumor-promoting and PKC-activating phorbol ester, TPA, to over-express OPN mRNA in a PKC-dependent manner. Unexpectedly, treatment of U105MG cells with Ca2+ ionophore (A23187) completely inhibited TPA-mediated induction of OPN while treatment with the intracellular Ca2+ antagonist TMB-8 had no significant effect. Elucidation of regulatory mechanisms for OPN induction in glioma cells should facilitate rational design of novel therapeutics for human malignant gliomas.

Calcium↗