Biochemical transformation of bulbar conjunctiva into corneal epithelium: an electrophoretic analysis.

When the entire corneal epithelium of the rabbit is mechanically removed, the denuded corneal stroma is completely resurfaced in 5-10 days with cells of conjunctival origin. The conjunctival cells differ from the corneal epithelial cells both morphologically and biochemically; however, within approximately 6 weeks, the conjunctival cells are converted into functional cornea epithelial cells. Using high-resolution agarose-gel electrophoresis, we compared the soluble proteins from functional conjunctiva (CON), functional corneal epithelium (EPI), and 'regenerating' corneal epithelium at eight intervals ranging from 24 hr to 6 weeks post-scraping. Comparison of CON and EPI patterns shows nine major mobility classes of proteins that fall into three subgroups: A = anodal, B = intermediate, and C = cathodal. The nine major classes have marked similarity in distribution and mobility, which may account for the apparent ease with which CON can transform into EPI during regeneration. Electrophoretic patterns of soluble proteins from regenerating epithelium suggest that the regeneration process occurs in three distinct phases: 24-72 hr post-scraping is a period of de-differentiation, 72 hr to 1 week is a period of reorganization, and 1-6 weeks is a period of differentiation. Specific protein groups are identified that represent fast-transforming, slow-transforming, conjunctival-specific, and corneal-specific proteins. Certain of these protein groups can be associated with particular stages in the regenerative process.

Evidence for an hereditary defect in taurine transport in the ciliary epithelium of an inbred strain of rabbits.

The concentration of taurine in the aqueous humour and serum of 21 rabbits with hereditary buphthalmia (Bu rabbits-genotype bu/bu) was compared with the aqueous and serum taurine levels of eight strain-related normal rabbits (JAX) and nine non-strain-related normal rabbits (MCV). There was a significant difference in the mean aqueous taurine concentration in each of the three groups. The Bu rabbits had only 29% of the MCV rabbits' level while the JAX rabbits were intermediate with 56% of the MCV level. It is suggested that some of the JAX rabbits may be heterozygous and the Bu rabbits homozygous for a semi-dominant allele of a gene that is less efficient in taurine transport in the ciliary epithelium than the normal allele represented by the MCV animals.

A cytologic aid to diagnosing congenital glaucoma.

Using the Giemsa and Papanicolaou staining methods, the authors studied the superficial corneal epithelium of 17 glaucoma patients and 25 normal patients. Smears of the normal patients exhibited a high frequency of precornified cells and a paucity of cornified cells with pyknotic nuclei. Smears of the glaucomatous patients illustrated striking tinctorial changes; these changes were so pronounced that examination of a single section strongly suggested a diagnosis of glaucoma. A case report is presented in which a preliminary diagnosis of congenital glaucoma was disproved by these staining techniques.

A cytologic aid in the diagnosis of congenital glaucoma.

The superficial corneal epithelium of 17 patients with glaucoma varying in age from nine days to 16 years and 25 normal individuals varying from nine months to 16 years were studied comparing findings using the Giemsa and Papanicolaou staining methods. The normal individuals exhibited a high frequency of precornified cells and a paucity of cornified cells with pyknotic nuclei. Smears of 16 of the 17 patients with glaucoma stained by the Papanicolaou method illustrated striking tinctorial changes. In a 9-day-old patient with glaucoma there were occasional normal cells, but many others varied greatly both in shape and size. In addition, highly cornified, deep orange, Papanicolaou stained cells with pyknotic nuclei were noted. These changes were so pronounced that examination of a single section strongly suggested a diagnosis of glaucoma. Cells in the older patients (6 to 16 years) frequntly exhibited a high degree of cornification, extensive cell fragmentation, darkly stained pyknotic nuclei, and areas of ghost cells. The cytologic characteristics of stained corneal epithelium cells were a demonstrable aid in the early diagnosis of glaucoma.

Staining of rabbit eosinophil and pseudoeosinophil leukocytes.

Air-dried rabbit blood was stained by HE, PAS and a modification of the Undritz II method. Eosin stained granules red in the eosinophil leukocytes. PAS was negative and the modified Undritz method failed to give consistent results. Cells with eosinophilic granules appeared in the corneal stroma 1 h after removing the corneal epithelium. They were stained red consistently by both eosin and the modified Undritz II method. Electron micrographs failed to demonstrate crystalloids in the granules. Because of the staining characteristics and the lack of crystalloids in their granules these cells were classified as pseudoeosinophil leukocytes. The electron micrographs showed some glycogen 12 h after denuding the cornea, however, glycogen was not well stained by PAS until 18 h after denuding.

Pseudoeosinophilic leucocyte response to denuding the rabbit cornea.

After scraping the epithelium from the rabbit's cornea, pseudoeosinophilic leucocytes appeared in the limbic area within one hour and began to advance, presumably by means of pseudopodia, into the anterior corneal stroma. The cytoplasmic granules of these cells were intensely stained by eosin and by the Undritz peroxidase method during the first hour, but were not stained by the PAS method until the eighteenth hour. Electron microscopy failed to show crystalloids in the granules. The cellular changes were followed until the fourth day, by which time most of the cells had disappeared by fragmentation, karyorrhexis and lysis.