Figure 1

Electron microscope examination of microvasculature in the brain from MPS III A patient. Representative capillaries in putamen (A), hippocampus (D), and cerebellum (G) of the control brain were characterized by normal ultrastructural appearance. In MPS III A patient, capillaries in the putamen (B, C), hippocampus (E, F), and cerebellum (H, I) showed swollen and degenerated EC and pericytes containing mucopolysaccharides. Significant protein-filled perivascular spaces surrounding a capillary were observed in all analyzed brain structures. A large accumulation of disorganized collagen was observed between BM covering the ECs (E, F, H). Some capillaries displayed ECs separating from the BM (B, H, I). EC - endothelial cell, BM - basement membrane, A – axon, P – pericyte, Nu – nucleus, Coll – collagen accumulation, * - separation of EC from BM or P, + - extracellular edema. Magnification in (A), (E) is 5,600; in (B) is 7,100; in (C), (F), is 1,800; in (D), (G) is 3,500; in (H) is 2,800; in (I) is 4,400.