Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 91 (1996), S. 376-384 
    ISSN: 1432-0533
    Keywords: Key words Epilepsy ; Immunohistochemistry ; Neurotransmitter ; Pathology ; Tumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Circumscribed cortical lesions are frequently encountered in patients with chronic focal epilepsies. However, the pathogenesis of seizures is poorly understood. To determine whether the perilesional cortex shows evidence for abnormal excitatory or inhibitory neurochemical activity, we immunohistochemically examined the distribution of the α1 subunit of the GABAA receptor (GABAR), the N-methyl-d-aspartate receptor subunit 1 (NR1), and glutamate decarboxylase (GAD) in 30 surgical specimens of neocortical epilepsy-associated lesions. These comprised 7 low-grade gliomas, 2 gangliogliomas, 2 dysembryoplastic neuroepithelial tumors, 4 glioneuronal malformations, 5 vascular malformations, and 10 glial or gliomesodermal scars. All specimens originated from patients with chronic pharmacoresistant epilepsy. In 73% of the cases there was a distinct difference in immunoreactivity for GABAR, GAD or NR1 between the perilesional zone and the normal cortex. With each of the markers there was reduced perilesional immunoreactivity in 30% of the specimens. Increased staining for GAD was seen in 17%, for GABAR in 7%, and for NR1 in 13% of the cases. The age at surgery, onset of seizures, epilepsy duration, and maximal seizure frequency did not differ significantly between patients with normal and those with altered perilesional immunoreactivity patterns. Although the perilesional changes for GAD, GABAR or NR1 were heterogeneous, they suggest a disturbed balance between excitatory and inhibitory synaptic transmission which may contribute to the pathogenesis of focal seizures.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0533
    Keywords: Key words Epilepsy ; Immunohistochmistry ; Receptor ; Neurotransmitter ; Tumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Oligodendrogliomas and dysembryoplastic neuroepithelial tumors (DNT) are frequently associated with epilepsies and share the presence of oligodendroglia-like cells with small round nuclei and optically empty perinuclear halos. The two entities may be difficult to discriminate in small surgical specimens and the origin and differentiation of the oligodendroglia-like cells has been controversial. To better characterize and distinguish the two entities we examined 25 oligodendrogliomas and 16 DNT immunohistochemically for the presence of the proliferation–associated Ki-67 antigen and the following neural antigens: the α1 subunit of the GABAA receptor (GABAR), N-methyl-d-aspartate receptor subunit 1 (NR1), glutamate decarboxylase, neuronal nuclei antigen (NeuN), the embryonal form of the neural cell adhesion molecule (E-NCAM), synaptophysin, neurofilament protein (NFP), and glial fibrillary acidic protein (GFAP). Labeling indices for the Ki-67 antigens were generally less than 1% in both entities. In oligodendrogliomas, more than 50% of the tumors contained NR1- or E-NCAM-positive oligodendroglia-like cells, whereas NeuN-positive tumor cells were never observed. In DNT, NeuN- and NR1-positive tumor cells were present in 44% of the cases each; E-NCAM positivity was less frequent (19%). In both entities, immunoreactivity of oligodendroglia-like cells for GABAR and glutamate decarboxylase was rare and positivity for synaptophysin and neurofilament protein was absent. Some GFAP-positive tumor cells were present in approximately 70% of the cases in both entities. Except for the striking difference in NeuN positivity, the immunohistochemical profiles of oligodendroglia-like cells in DNT and oligodendrogliomas largely overlap and the differential diagnosis continues to rest mainly on conventional histopathological features. The NR1 positivity and the recently reported generation of action potentials in oligodendroglioma cells are consistent with neuronal differentiation and may contribute to the high epileptogenic potential of oligodendrogliomas.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...