0000000000448743
AUTHOR
V. Krahn
The pia mater at the site of the entry of blood vessels into the central nervous system
The entry of blood vessels into the central nervous system (CNS) has been studied at the surface of the brain stem and the spinal cord of two cats and two rabbits. The study was carried out by scanning electron microscopy (SEM). The results obtained by SEM concerning the layers of the pia mater corresponded to those obtained by other authors who used transmission electron microscopy. Between the basal lamina of the superficial glial membrane of the CNS and the cells lining the subarachnoid space, a pial connective tissue space could be clearly recognized. The blood vessles crossing the subarachnoid space were also covered by leptomeningeal lining cells. At the site of entry of these blood v…
Expression patterns of complex glycoconjugates and endogenous lectins during fetal development of the viscerocranium
Summary Experimental evidence suggests that carbohydrates and their corresponding receptors (endogenous lectins) decode biological information. Therefore, the expression of complex oligosaccharides — the potential ligand part of this recognition system — during chondrogenesis and osteogenesis was determined in the viscerocranium of fetal rats by mapping the staining patterns of exogenous lectins. Results were compared with the expression of bone- and/or cartilage-specific core proteins and the binding profiles of neoglycoconjugates. These synthetic tools make possible the localization of sugar-ligand-binding sites. The spatial and temporal distribution patterns of glycoconjugates were highl…
Phagocytosis of erythrocytes in the subarachnoid space at spinal nerve exits
After intracisternal injection of heparinised autologous blood in cats, spinal nerve exits (SNE) of the subarachnoid space (SAS) were examined by scanning and transmission electron microscopy. Phagocytes, erythrocytes and erythrophages (= macrophages which had phagocytosed red blood cells) were found at SNE. Some lining cells of the SAS had retracted from the adjacent cells and had rounded up. Cells which formed an integral part of the subarachnoid lining cells also had phagocytosed erythrocytes. Debris of an exhausted erythrophage was phagocytosed by other macrophages. Finally the observation has been made that erythrophages are capable of leaving the SAS actively by migrating through the …
Characterization of glycoconjugate expression during development of Meckel's cartilage in the rat
The staining patterns of 24 biotinylated lectins were analyzed in serial sections of the mandible of 13- to 21-day-old rat embryos by means of the avidin-biotin-peroxidase method. A ubiquitous distribution of binding sites was demonstrated after incubation with Con A (Canavalia ensiformis), DSL (Datura stramonium; except bone matrix), and WGA (Triticum vulgare). ECL (Erythrina cristagalli), GSL I (Griffonia simplicifolia), SJA (Saphora japonica), VVL (Vicia villosa), DBA (Dolichus biflorus), UEA I (Ulex europeus), and LTA (Lotus tetragonobolus) were constantly negative. In early stages of development, GSL II (Griffonia simplicifolia II) was a selective marker of prechondral blastema. In con…
Distribution patterns of neoglycoprotein-binding sites (endogenous lectins) and lectin-reactive glycoconjugates during cartilage and bone formation in human finger.
The distribution of endogenous lectins, visualized by labelled neoglycoproteins, and of defined oligosaccharide structures, reactive with plant lectins, during fetal development of the fingers was analyzed in sections of human 3- to 8-month-old fetal specimens. Chondrogenesis as well as ossification were correlated with characteristic modulations in the expression of both glycoligand-binding molecules and characteristic carbohydrate structures. Occurrence of xylose-specific receptors was judged to be an early sign of cartilage development. Similarly, α-mannosyl residues that had been attached to labelled carrier proteins were strongly bound by the extracellular matrix already during early s…