PubMed · 4869521
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Z Zsebök, R Pálvölgyi, T Hernády. 1967-05-27. [On gamma-encephalography].. https://pubmed.ncbi.nlm.nih.gov/4869521/
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Pilocytic astrocytomas (PAs) are WHO grade I brain tumors that do not typically progress to more malignant grades of astrocytoma. Whereas there have been significant advances in the molecular genetics of high-grade astrocytomas, relatively little is known about the genetic changes associated with PA formation. In an effort to better characterize these low-grade neoplasms, we compared the gene expression profiles of six sporadic and two neurofibromatosis 1-associated PAs with other tissues and cell lines of both astrocytic and oligodendroglial origin. Hierarchical cluster analysis of gene expression data clearly delineated PAs from low-grade oligodendrogliomas and normal white matter. The two NF1-associated tumors and one of the sporadic PAs displayed expression profiles that were more closely related to those of cultured normal human fetal astrocytes. However, PAs also expressed individual genes typically associated with oligodendroglial lineage (e.g., proteolipid protein and PMP-22). The expression patterns of specific genes (e.g., ApoD) were unique to PA tumors, whereas genetic changes characteristic of high-grade astrocytomas were not encountered. Differential expression of two transcripts, neural cellular adhesion molecule and connexin-43, was confirmed at the protein level, suggesting that these cell adhesion molecules might be particularly important in the molecular pathogenesis of these tumors. We conclude that PAs are genetically unique gliomas with gene expression profiles that resemble those of fetal astrocytes and, to a lesser extent, oligodendroglial precursors.
The functional role of BK channels, which are consistently expressed in glioma cells, is not clear. Here we show that the BK channels are regularly active in human 1321N1 astrocytoma cells at physiological membrane potentials. The proliferation of the cells at the physiological external [K+] of 5 mM is compared with that at the elevated external [K+] of 20 mM, simulating the situation in rapidly growing, necrotic tumours in vivo. High extracellular [K+] in the range 10-30 mM significantly increases the proliferation of 1321N1 cells. This K+ induced proliferation can be completely abolished by applying the specific BK channel blockers iberiotoxin (IBTX) or 1 mM tetraethylammonium (TEA). Neither blocker has any effect on cell growth at 5 mM [K+]e. These findings indicate a particular role of BK channels in astrocytoma cell proliferation.
The dysembrioplastic neuroepithelial tumor (DNT) is a benign and slow-growing temporal lobe cortical lesion that presents with clinically unresponsive partial and complex seizures, with onset before age 20 yr. DNT shows a multinodular architecture and the presence of mixed glioneural elements. The authors report on a case of DNT diagnosed by the intraoperative smear cytological technique. We describe the cytological characteristics of smear preparations of DNT, with emphasis on the differential diagnosis. The authors present a 5-yr-old male with partial seizures for the preceding 3 yr. The patient showed no other neurological deficits. Magnetic resonance identified a lesion in the cortical area of the right temporal lobe. The smear cytology showed small, round, oligodendroglial-like cells arranged in lobules, with microcystic spaces containing ganglion cells floating in a fine fibrillary background. Histology confirmed the diagnosis of DNT. This report shows that the smear preparation can be trustworthy for the intraoperative diagnosis of DNTs, helping to determine the appropriate neurosurgical procedure and thus avoiding extensive and unnecessary resections.