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  • 1
    ISSN: 1432-0533
    Schlagwort(e): Proliferating cell nuclear antigen (PCNA) ; Ki-67 ; Medulloblastoma ; Apoptosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The distribution of proliferating cell nuclear antigen (PCNA)-(clone PC 10)- and Ki-67- (clone MIB-1)-positive nuclei was investigated in 60 medulloblastomas of childhood. Although the labeling index of the two markers did not coincide, both showed a wide range of parallel variations. The percentage of positive nuclei was similar in both classic and desmoplastic tumors. A variable proliferation capacity was found in the different tumor structures. Areas with neuronal and glial differentiation showed very few positive nuclei; these were very abundant in the infiltration areas, and along penetrating vessels from subarachnoidal growths. Pale islands were negative or positive only in their peripheral part. Large-cell areas were richer in positive nuclei than classic ones, accounting for their more malignant character. Hyperchromatic round nuclei, not belonging to necrotic foci and called lymphocyte-like nuclei, differently interpreted in the past, were vairiably found in every case. They are known, from previous experience, to stain orange with Acridine Orange fluorochroming, like single-stranded DNA. They were not easily distinguishable from mitoses and were stained by in situ end-labeling of DNA strand breaks, as demonstrated by incorporation of labeled nucleotides. They were regarded as possible apoptotic nuclei, representing either a peculiar type of cell death or the preservation of the cell deletion capacity, typical of the embryonal tissue of origin.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1433-0350
    Schlagwort(e): Ependymomas ; Prognostic factors ; Pediatric ; Brain tumor ; Ependymoblastoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The prognostic value of a series of histologic signs and clinical features was studied in a series of 298 ependymomas, collected from different institutions. The distribution of tumor sites varied in relation to patient age, with infratentorial cases prevailing under 4 years. Life table univariate analysis demonstrated as highly significant prognostic factors: (1) the number of mitoses; (2) endothelial hyperplasia; (3) necrosis; (4) intracranial site; (5) age 〈4 years. Multivariate analysis by tumor site revealed mitoses cell density, age 〉16 years in supratentorial cases, and subependymoma in infratentorial cases to be prognostically important. Comparison of the anaplastic variant with the other tumor types in intracranial cases did not show a significant difference in survival even though the median survival time of anaplastic cases was shorter. The main conclusion is that the histological criteria employed to diagnose anaplasia in gliomas are not useful for recognizing anaplasia in ependymomas. The number of mitoses is a very important prognostic factor in supratentorial cases, whereas endothelial proliferations and necroses are much less important as prognostic factors than in gliomas.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Child's nervous system 10 (1994), S. 462-463 
    ISSN: 1433-0350
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    ISSN: 1433-0350
    Schlagwort(e): Gliomas ; Oncogenes ; Endothelial cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In this study we analyzed the expression of mRNA for PDGF-B and PDGF B-type receptor (PDGFrecB) in 42 biopsy specimens from human astrocytic gliomas and other brain tumors. All gliomas expressed PDGF-B mRNA at higher levels than found in peritumoral and normal nervous tissues. Levels of PDGF-B transcripts correlated strongly with those of mRNA for glial fibrillary acidic protein. Thus, the production of PDGF-B mRNA may be attributed mainly to tumoral glial cells. PDGFrecB transcripts were found in 24 out of 29 gliomas, in agreement with the hypothesis of an autocrine growth stimulation in these tumors. Moreover, mean levels of PDGFrecB expression were higher in glioblastomas than in astrocytomas and over 30-fold higher in meningiomas than in gliomas. This suggests that in gliomas PDGFrecB can be expressed also by vascular elements, in agreement with the hypothesized existence of a paracrine mechanism that may be responsible for the endothelial hyperplasias.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Child's nervous system 8 (1992), S. 456-456 
    ISSN: 1433-0350
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    ISSN: 1573-7373
    Schlagwort(e): vessels ; irradiation ; glioblastoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The vascular response to irradiation was studied in peritumoral cortex and tumor areas in 9 autopsied cases of glioblastoma multiforme and in 10 biopsies of reoperated cases. The study was carried out by histological, immunohistochemical and electron microscope procedures. Hyaline thickening of the vessel walls with deformation and impoverishment of endothelial nuclei are the most striking features. Formation of large PAS-positive areas from the confluence of thickened vessel walls and development of a fibroblastic proliferation follow. Fibroblastic areas may entrap tumor glial cells. In PAS-positive areas a special population resembles myofibroblasts of tissue scars. Electron microscope reveals the production of collagen fibrils in and outside vessel walls. The presence of collagen III and IV is in line with the present interpretation of the mesodermic component.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    ISSN: 1590-3478
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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