Chemical and Immunological Characterization of Galactosyl-β1-3-Globoside in Bovine, Human, and Rat Brain

Abstract: Our studies of bovine brain neutral glycosphingolipids (Ngsls) have revealed the presence of several short-chain (containing -CHO 1–4) and previously uncharacterized long-chain (−CHO > 4–5) Ngsls. We reported the structural characterization of brain GgOse₄Cer (GA1) and have now purified another brain Ngsl to homogeneity. The purified Ngsl migrated close to standard GgOse₄Cer and nLcOse₅Cer on a TLC plate employing two different solvent systems. The carbohydrate molar composition indicated the presence of Gal/Glc/GalNAc in a ratio of 2.8:1.0:0.9. Five permethylated alditol acetate peaks were characterized as 2,3,4,6-OMe₄Gal, 2,4,6-OMe₃Gal, 2,3,6-OMe₃Gal, 2,3,6-OMe₃Glc, and 4,6-OMe₂GalNAcMe by gas chromatography-mass spectrometry. The anomeric carbohydrate sequence has been determined by specific exoglycosidase digestion. Six-hundred megahertz ¹H NMR spectroscopy of the oligosaccharide released by ceramide glycanase hydrolysis confirmed the structure of the Ngsl as Galβ1-3GalNAcβ1-3Galα1-4Galβ1-4Glc\1-1Cer or IV³GalGbOse₄Cer. Using the immunooverlay technique with anti-stage-specific embryonic antigen 3 antibody, it was found in bovine, rat, and normal adult human brain and bovine myelin, but not in human or rat myelin.     

Ultrastructure of nerve in erythema nodosum leprosum (ENL)

Gross changes of myelinated fibres and Schwann cells at different degenerative stages were present in all five ENL nerve lesions. Besides these changes, infiltrating cells mainly macrophages, deposition of excessive collagen and perineurial vessel damage were also observed.