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  • Articles: DFG German National Licenses  (5)
  • Ganglioglioma  (2)
  • Non-radioactive in situ hybridization  (2)
  • Gamma aminobutyric acid  (1)
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  • Articles: DFG German National Licenses  (5)
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  • 1
    ISSN: 1432-0533
    Keywords: Key words Stem cell ; Tumor ; Malformation ; Epilepsy ; Ganglioglioma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The etiology and pathogenesis of complex focal lesions associated with chronic, intractable epilepsy are largely unknown. Some data indicate that malformative changes of the central nervous system may preceed the development of gangliogliomas and other epilepsy-associated neoplasms. In the present immunhistochemical study, we have examined epilepsy-associated lesions for CD34, a stem cell marker transiently expressed during early neurulation. Surprisingly, most tissue samples from patients with chronic epilepsy (n = 262) revealed neural cells immunoreactive for CD34. Prominent immunoreactivity was detected in gangliogliomas (74%), low-grade astrocytomas (62%) and oligodendrogliomas (59%). Only 52% of non-neoplastic, malformative pathologies, such as glio-neuronal hamartias or hamartomas showed solitary or small clusters of CD34-immunoreactive cells. None of the adult control tissues (n = 22), none of the specimens obtained from the developing human brain (n = 44) and none of those tumor samples from patients without epilepsy (n = 63) contained CD34-immunoreactive neural cells. However, a malignant teratoma with microscopic features of early neural differentiation displayed a focal CD34-immunoreactive staining pattern. The majority of CD34-immunoreactive cells co-localized with S-100 protein and a small subpopulation was also immunoreactive for neuronal antigens. CD34 may, thus, represent a valuable marker for the diagnostic evaluation of neoplastic and/or malformative pathological changes in epilepsy patients. The CD34 immunoreactivity of these lesions indicates an origin from dysplastic or atypically differentiated neural precursors. Further studies may elucidate the functional significance of CD34 expression during the pathogenesis of epilepsy-related focal lesions as well as during neurogenesis.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0533
    Keywords: Epilepsy ; Gamma aminobutyric acid ; Receptor ; Ammon's horn sclerosis ; Hippocampus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Alterations of gamma aminobutyric acid (GABA)-mediated neurotransmission have been implicated in the pathogenesis of epilepsies. Here we examine the distribution of the GABAA receptor in the hippocampus of 78 surgical specimens from patients with chronic pharmacoresistant focal epilepsies. The receptor was localized immunohistochemically with the monoclonal antibody bd-24 which selectively recognizes the α1 subunit of the GABAA receptor. The results were compared with the receptor distribution of 28 normal hippocampal specimens obtained at autopsy. In the great majority of the surgical specimens a loss of GABAA receptor immunoreactivity was present in CA1 (92.3%), CA4 (78.2%), the dentate granular cell layer (70.5%) and the molecular layer of the dentate gyrus (65.4%). The subiculum revealed a normal staining pattern in all but 4 cases. In no instance did we observe an increase of immunoreactivity in any region or cell population. The decrease of GABAA receptor immunoreactivity was closely related to neuronal loss in the respective specimen and to Ammon's horn sclerosis. There was no correlation between GABAA receptor loss and the patient's age at surgery, duration of seizures, age at onset of seizures and to the presence or absence of secondary generalized tonic clonic seizures. The data suggest that the observed loss of GABAA receptor immunoreactivity is a secondary phenomenon rather than an event that is relevant for the pathogenesis of epileptic seizures.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0533
    Keywords: Ganglioglioma ; Hamartia ; Proliferation ; Ki-67 ; p53
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Gangliogliomas are tumors composed of intimately admixed neuronal and glial components and account for approximately 1% of all brain tumors. Here we report the histopathological findings in 61 gangliogliomas. Epilepsy was the most common presenting symptom. Most gangliogliomas were located in the temporal lobes (74%). Thirteen percent of the gangliogliomas were associated with glioneuronal hamartias. There was considerable variation in neuronal size and density, presence of binucleated neurons, calcifications, desmoplasia, lymphocytic infiltrate, pilocytic differentiation, Rosenthal fibers, location, or histological uniformity. Fifteen percent of the gangliogliomas contained areas of purely astrocytic differentiation. All tumors were examined immunohistochemically for an aberrant p53 tumor suppressor gene product and for the presence of nuclear antigens associated with cell proliferation (Ki-67, Ki-S1, proliferating cell nuclear antigen). In 45 of 61 cases (74%) labeling indices for Ki-67 were less than 1%. Nuclear labeling for Ki-67 was observed exclusively in the astrocytic component. Gangliogliomas with very large neurons had higher Ki-67 labeling indices and occurred in younger patients than gangliogliomas with small-or intermediate-sized neurons. None of the tumors had an aberrant expression of p53. The observations suggest that gangliogliomas may arise from glioneuronal hamartias through neoplastic transformation of the astrocytic component.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 89 (1995), S. 446-450 
    ISSN: 1432-0533
    Keywords: N-Methyl-D-aspartate receptor ; Epilepsy ; Non-radioactive in situ hybridization ; Hippocampus ; Ammon's horn sclerosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The hippocampal distribution of mRNA for the N-methyl-D-aspartate (NMDA) receptor subunit 1 (NR 1) was examined by non-radioactive in situ hybridization in 21 archival formalin-fixed and paraffin-embedded surgical specimens from patients with pharmacoresistant chronic epilepsy and in normal control specimens obtained at autopsy. Using the digoxigenin-labeling procedure, ribonucleotide probes were found to be significantly more sensitive than synthetic oligonucleotide probes. In normal autopsy specimens and in surgical specimens without Ammon's horn sclerosis there was intense NR 1 expression in a great majority of the dentate gyrus granular cells. Many neurons in the hippocampal pyramidal cell layer also revealed a strong signal intensity. The strata oriens and moleculare of Ammon's horn and the molecular layer of the dentate gyrus contained only few labeled neurons. In the subiculum and entorhinal cortex most neurons throughout various layers were positive. In hippocampal specimens of patients with chronic epilepsy there was a loss of NR 1-positive cells that was closely related to the overall neuronal loss in the respective specimen and to Ammon's horn sclerosis. These data suggest that the loss of NR 1 expression is a secondary phenomenon rather than an event that is relevant for the pathogenesis of epileptic seizures.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 89 (1995), S. 446-450 
    ISSN: 1432-0533
    Keywords: Key wordsN-Methyl-D-aspartate receptor ; Epilepsy ; Non-radioactive in situ hybridization ; Hippocampus ; Ammon's horn sclerosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The hippocampal distribution of mRNA for the N-methyl-D-aspartate (NMDA) receptor subunit 1 (NR1) was examined by non-radioactive in situ hybridization in 21 archival formalin-fixed and paraffin-embedded surgical specimens from patients with pharmacoresistant chronic epilepsy and in normal control specimens obtained at autopsy. Using the digoxigenin-labeling procedure, ribonucleotide probes were found to be significantly more sensitive than synthetic oligonucleotide probes. In normal autopsy specimens and in surgical specimens without Ammon's horn sclerosis there was intense NR1 expression in a great majority of the dentate gyrus granular cells. Many neurons in the hippocampal pyramidal cell layer also revealed a strong signal intensity. The strata oriens and moleculare of Ammon's horn and the molecular layer of the dentate gyrus contained only few labeled neurons. In the subiculum and entorhinal cortex most neurons throughout various layers were positive. In hippocampal specimens of patients with chronic epilepsy there was a loss of NR1-positive cells that was closely related to the overall neuronal loss in the respective specimen and to Ammon's horn sclerosis. These data suggest that the loss of NR1 expression is a secondary phenomenon rather than an event that is relevant for the pathogenesis of epileptic seizures.
    Type of Medium: Electronic Resource
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