Electron microscopic findings in corneal epithelial basement membrane degeneration.

In an attempt to correlate basement membrane changes with clinical symptoms we examined 29 specimens from 28 patients who had undergone corneal epithelial basement membranectomy for corneal epithelial basement membrane degeneration (CEBMD). Twenty-two of the 28 patients were women. Recurrent erosion was the most frequent symptom and occurred in 24 of the 29 eyes. The most common electron microscopic finding was reduplication of the basement membrane with loculated connective tissue. The electron microscopic finding that predicted clinical symptoms was absence of the basement membrane and hemidesmosomes, which occurred in 4 eyes with severe recurrent erosion.

Hemocytic encapsulation of implants in the tick Dermacentor variabilis.

Implants of Epon, inserted in Dermacentor variabilis (Say) through incisions in the cuticle, were encapsulated by hemocytes. We followed this process at intervals of 1,3,6, 12 and 24 h, and every 24 h thereafter up to 120 h. Degranulation of Type 1 granulocytes and coagulation of hemolymph were first seen at 1 h after implantation and were the earliest evidence of encapsulation. By 3 h after implantation, the degranulation and disintegration of granulocytes had formed a matrix at the Epon surface. From 6 h until encapsulation was completed, plasmatocytes and granulocytes continued to respond to degranulation and formed multiple cell layers around the Epon implant. The capsule was complete at 72 h after implantation. Completion was marked by decreasing degranulation, migration of hemocytes from the outermost layers of the capsule, and by the appearance of loosely attached hemocytes on the outer surface of the capsule. The most common junctional complex observed was gap junctions.