Structure of a collagen-GAG dermal skin substitute optimized for cultured human epidermal keratinocytes.

Collagen and glycosaminoglycan (GAG) dermal skin substitutes (membranes) were studied as substrates for cultured human epidermal keratinocytes. Structure of dermal substitutes was optimized for pore size to promote ingrowth of fibrovascular tissue from the wound bed and for culture of human keratinocytes of the membrane's surface. Pore size of the freeze-dried material was regulated by control of the temperature of freezing between -50 degrees C and -20 degrees C and by concentration of starting materials between 0.17% and 1.62% wt/vol. A nonporous surface of collagen-GAG was laminated to the membranes to provide a planar substrate for cultured epidermal keratinocytes. Thickness of dermal substitutes was regulated by control of the volume and concentration of starting materials. Biotin was conjugated to solubilized collagen for binding with avidin of specific quantities of biologically active molecules. The optimized membranes are suitable substrates for the culture of human epidermal keratinocytes, and together with the cells yield a composite material that is histologically similar to skin.

Neovascular glaucoma after intracapsular and extracapsular cataract extraction in diabetic patients.

A retrospective study of the rate of development of neovascular glaucoma after cataract extraction in 242 eyes of 186 diabetic patients identified neovascular glaucoma in 13 of 146 eyes (8.9%) after intracapsular extraction, in two of 17 eyes (11.8%) after extracapsular extraction with primary capsulotomy, and in zero of 53 eyes after extracapsular extraction without capsulotomy. The incidence of neovascular glaucoma was significantly lower in patients who underwent extracapsular extraction with preservation of an intact posterior capsule than in those undergoing intracapsular cataract extraction (P less than .01) or extracapsular cataract extraction with primary capsulotomy (P less than .05).