We studied the ultrastructural features of four consecutive subfoveal neovascularmembranes (SFNM) associated with age-related macular degeneration. Cellular components of the membranes included retinal pigment epithelial (RPE) cells, endothelium-lined vascular channels, macrophages, myofibroblasts, fibrocytes, glial cells, erythrocytes, and lymphocytes. Extracellular interstitial constituents included collagen fibrils, basal laminar deposits, fibrin and young elastic fibrils. These findings show that SFNMs consist of various cells originating from surrounding tissues and vessels. Among these RPE cells and macrophages are the main cellular components and in conjunction with various extracellular matrix, especially collagen, may play an important role in the formation and maintenance of the membranes.
Basement Membrane/surgery/ultrastructure ; Humans ; Macular Degeneration/complications ; Microscopy, Electron ; Retina/*ultrastructure ; Retinal Neovascularization/etiology/*pathology/surgery

OBJECTIVETo observe the dynamic process of basement membrane remodeling after the combined grafting of xenogenic acellular dermal matrix with autoskin.

METHODSThe rat skin wounds were covered with xenogenic porcine acellular dermal matrix overlaid with razor thin autoskin. The skin samples were collected at 1, 2, 3, 4, 8, 12 and 16 post-grafting weeks. The changes in laminin expression in the basement membrane and the ultrastructure of the basement membrane at 12 post-grafting weeks were observed by immunohistochemistry and transmission electron microscopy. The results were compared with those in simple thin autoskin grafting as the control.

RESULTSThe laminin expression in the combined grafting was higher than that in control. At 12 post-grafting weeks, the basement membrane in combined grafting rats was clear and continuous and the hemidesmosome was relatively more in amount and distributed evenly. While in the autoskin group, the lamina densa in the basement membrane was blurred and discontinuous with a decrease in and uneven distribution of hemidesmosome.

CONCLUSIONThe increased expression of laminin in the basement membrane in the combined grafting rats might be beneficial to the remodeling of the basement membrane and to strengthening the connection of epithelium to the dermis, thus wound healing quality would be improved.

Animals ; Basement Membrane ; metabolism ; ultrastructure ; Burns ; surgery ; Dermis ; transplantation ; Immunohistochemistry ; Laminin ; biosynthesis ; Male ; Microscopy, Electron ; Rats ; Rats, Wistar ; Skin Transplantation ; methods ; Swine ; Time Factors ; Transplantation, Autologous ; Transplantation, Heterologous ; Wound Healing