Analysis of XXXX by immunohistochemistry, electron microscopy and cell culture.

@entity1 @entity5 @entity538 @entity1653 @entity10786
Intracranial @entity1653 ( @entity1653 ) from seven @entity1 were examined by immunostaining, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and cell culture. Positive staining for Factor VIII-related antigen was restricted to capillary endothelial cells. There was no reaction with @entity538 ( @entity538 ) serum or anti-S-100 protein serum. In these @entity5 TEM displayed extracellular basement membrane-like material (BMLM), cytoplasmic intermediate filaments (IF) associated with a dense body, dilated rough-surfaced endoplasmic reticulum containing BMLM, a small area of interdigitation of cell membranes, and a unique intercellular punctate or linear density. By SEM these @entity5 had intercellular shell-like or reticular structures and irregularly branched capillaries which were compressed by ellipsoidal- or @entity10786 -shaped @entity5 cells. Short-term monolayer culture showed rapid and vigorous growth of @entity5 cells, and the formation of pseudolumens but not of whorls. The TEM of cultured cells also showed cytoplasmic IF associated with the dense body. By SEM the cultured cells were flat and had a discoid nucleus with conspicuous nucleolar hillocks. Our results show that @entity1653 are mainly poorly specialized mesenchyme-related @entity5 of the meninges; some possess a potential for aggressive growth and some for differentiation into smooth muscle cells. Further study is needed to determine their histogenesis.
