Cytochemical Specializations on the Luminal Surface of Blood Vessels in the Developing Rat Central Nervous System

Author(s):  
R. S. Hannah ◽  
T. H. Rosenquist

Developing blood vessels in the rat central nervous system exhibit several unusual luminal features. Hannah (1975) used high voltage electron microscopy to demonstrate numerous ridges of endothelium, some near junctional complexes. The ridges produced troughs (which may appear as depressions) in the endothelial surface. In some areas ridges extended over the troughs, removing them from direct contact with the luminal surface. At no time were the troughs observed to penetrate the basal laminae. Fingerlike projections also extended into the lumina.To determine whether any chemical specializations accompanied the unusual morphological features of the luminal surface, we added 0.1% Alcian blue (Behnke and Zelander, 1970) to the 3% glutaraldehyde perfusate (cacodylate buffer, pH 7.4). After Alcian blue had reacted with the luminal glycocalyces, the dye was dissociated with MgCl2 via critical electrolyte concentration method of Scott and Dorling (1965). When these methods are applied together, it is possible to differentiate mucopolysaccharides (glycosaminoglycans or GAG) with the electron microscope.

ABSTRACT Recent advances of three-dimensional (3D) Doppler application is HDlive flow providing a realistic rendering of fine peripheral blood vessels, such as vascularity of the lung, brain, and eyeballs. The picture of the month demonstrates an oblique– sagittal view of the brain vascularity. Flow imaging can add both angiostructural and functional information to structural findings of normal and abnormal central nervous system. How to cite this article Pooh RK. 20-week Brain Vascularity by Transvaginal 3D HDlive Flow. Donald School J Ultrasound Obstet Gynecol 2016;10(3):203-204.


2021 ◽  
Vol 22 (15) ◽  
pp. 8248
Author(s):  
Ximena Vásquez ◽  
Pilar Sánchez-Gómez ◽  
Verónica Palma

Glioblastoma (GBM) is the most aggressive and common primary tumor of the central nervous system. It is characterized by having an infiltrating growth and by the presence of an excessive and aberrant vasculature. Some of the mechanisms that promote this neovascularization are angiogenesis and the transdifferentiation of tumor cells into endothelial cells or pericytes. In all these processes, the release of extracellular microvesicles by tumor cells plays an important role. Tumor cell-derived extracellular microvesicles contain pro-angiogenic molecules such as VEGF, which promote the formation of blood vessels and the recruitment of pericytes that reinforce these structures. The present study summarizes and discusses recent data from different investigations suggesting that Netrin-1, a highly versatile protein recently postulated as a non-canonical angiogenic ligand, could participate in the promotion of neovascularization processes in GBM. The relevance of determining the angiogenic signaling pathways associated with the interaction of Netrin-1 with its receptors is posed. Furthermore, we speculate that this molecule could form part of the microvesicles that favor abnormal tumor vasculature. Based on the studies presented, this review proposes Netrin-1 as a novel biomarker for GBM progression and vascularization.


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