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  • 1
    ISSN: 1432-0533
    Schlagwort(e): Key words p27/kip1 ; Oligodendrogliomas ; Histological grading ; Prognosis ; MIB-1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract p27/kip1 regulates the G1-S transition of the cell cycle by inhibiting cyclinD-CDK4, cyclinE-CDK2 and cyclinA-CDK2 complexes. Regulation of p27 levels occurs mainly post-translationally by ubiquitin-mediated proteasomal proteolysis. Although genetic changes of p27/kip1 are extremely rare, in many human carcinomas p27 levels are reduced, correlate with histological malignancy, and are associated with poor prognosis. In astrocytic gliomas, p27 decreases with anaplasia and is almost absent in glioblastomas. p27/kip1 was immunohistochemically studied in 37 oligodendrogliomas, categorized according to WHO classification. In this series, the immunohistochemical reaction for p27 was confined to nuclei. p27 score showed a tendency to decrease with malignancy. When the p27 score was considered as high versus low expression (cut-off of p27 labeling index, LI, at 25%), it represented an independent prognostic factor in univariate (P = 0.02) and in multivariate analysis (P = 0.04). The risk ratio suggested that the p27 low expression group had a threefold increased possibility to show a reduced survival. Moreover, p27 levels did not correlate with MIB-1 LI, suggesting that p27 is not merely associated with the control of proliferation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1433-0350
    Schlagwort(e): Childhood gliomas ; p53 ; Proliferation markers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Thirty cases of hemispheric astrocytic tumors of childhood, consisting of 11 pilocytic astrocytomas, 2 fibrillary astrocytomas, 9 anaplastic astrocytomas, and 8 glioblastomas, were studied for the presence ofp53 mutations and for immunohistochemical demonstrations ofp53 and proliferation markers PCNA and Ki-67 MIB-1. The study was performed using polymerase chain reaction (PCR)-as-sisted single-strand conformation polymorphism analysis of exons 5–8 and direct sequence analysis of PCR products. For immunohistochemistry, DO1 and PAb 1801 were used. No mutation and no positivity forp53 protein were found in pilocytic astrocytomas. Mutations (at codons 144, 202, and 245) were found in 2 out of 8 glioblastomas and in 1 out of 9 anaplastic astrocytomas, whereas positive staining was found in 11 out of 17 malignant gliomas. Cases with mutations showed the highestp53 labeling index and also PCNA and MIB-1 labeling indices. The negative results in pilocytic astrocytomas are in line with the benign course of these tumors, whereas for malignant gliomas no difference seems to exist in comparison with adult cases.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neuro-oncology 34 (1997), S. 31-35 
    ISSN: 1573-7373
    Schlagwort(e): low-grade astrocytoma ; proliferation markers ; MIB-1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Well-differentiated astrocytomas may transform into malignant astrocytomas in time. In surgical specimens, when the histological picture strictly corresponds to that of grade II glioma, the transformation is unpredictable. Clinically, the bad outcome of a quota of astrocytomas is a well known phenomenon. The use of proliferation markers, and recently of MIB-1 LI, for detecting the proliferation potential comes out to be a useful tool for prognosis. A survival analysis of fifty astrocytomas grade II according to the WHO classification was performed with univariate and multivariate analysis of a series of clinical and histological parameters. MIB-1 LI was calculated and compared with all the other parameters. A cut-off of 8% of MIB-1 LI divided the astrocytomas in two groups with significantly different survival (p=0.0066): median survival time of 1062 versus 1686 days. According to multivariate analysis MIB-1 LI resulted to be an independent factor (p=0.002) along with extension of surgical removal (partial versus total), postoperative Karnofsky status (≥ 70 versus 〈 70) and age (≤ 30 versus 〉 30). The interpretation of well-differentiated astrocytomas with high MIB-1 LI is that the increasing number of cycling cells precedes phenotypic transformation. MIB-1 LI can be used as a prognostic factor.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Journal of neuro-oncology 35 (1997), S. 169-176 
    ISSN: 1573-7373
    Schlagwort(e): medulloblastoma ; childhood ; adult ; pathology ; proliferation ; potential ; differentiation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The appearance of medulloblastoma in adult age and the uncertainoverlapping of prognostic factors in pediatric and adult populationsstimulate the question of whether medulloblastoma is different in adults andin children. The pathologic features, proliferation potential andglial/neuronal differentiation have been investigated in 42 adultmedulloblastomas and 42 medulloblastomas of children; the quantitative datahave been compared between the two groups of age. Homer-Wright rosettes,nuclear polymorphism and histologic signs of neuronal differentiation weremore frequent in children cases; GFAP-positive tumor cells and desmoplastictype were more frequent in adult cases. The mean, median and rage of LIs,with PCNA and MIB-1 were significantly (p 〈 0.05) higher in adults thanin children. All cases, independently from age of the patients wereimmunoreactive with markers of neuronal commitment (class III beta tubulinisotype, MAP-2, neurofilaments). The immunoreactivity pattern suggested amore mature neuronal character in desmoplastic cases of adults than ofchildren and in classic cases of children than of adults. In conclusion,some phenotypic differences between childhood and adult medulloblastomaexist, but do not support a substantially different course of the disease.The higher proliferation potential in adult than in childhood cases isunexpected in a tumor of embryonal origin, and reduces the applicability ofCollin‘s law to medulloblastoma.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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