Preface. Acknowledgements. Introduction. References. List of Structures. Index of Abbreviations. Diagrams.

The Rat Brain in Stereotaxic Coordinates

In this paper we present keratin expression data that lend strong support to a model of corneal epithelial maturation in which the stem cells are located in the limbus, the transitional zone between cornea and conjunctiva. Using a new monoclonal antibody, AE5, which is highly specific for a 64,000-mol-wt corneal keratin, designated RK3, we demonstrate that this keratin is localized in all cell layers of rabbit corneal epithelium, but only in the suprabasal layers of the limbal epithelium. Analysis of cultured corneal keratinocytes showed that they express sequentially three major keratin pairs. Early cultures consisting of a monolayer of "basal" cells express mainly the 50/58K keratins, exponentially growing cells synthesize additional 48/56K keratins, and postconfluent, heavily stratified cultures begin to express the 55/64K corneal keratins. Cell separation experiments showed that basal cells isolated from postconfluent cultures contain predominantly the 50/58K pair, whereas suprabasal cells contain additional 55/64K and 48/56K pairs. Basal cells of the older, postconfluent cultures, however, can become AE5 positive, indicating that suprabasal location is not a prerequisite for the expression of the 64K keratin. Taken together, these results suggest that the acidic 55K and basic 64K keratins represent markers for an advanced stage of corneal epithelial differentiation. The fact that epithelial basal cells of central cornea but not those of the limbus possess the 64K keratin therefore indicates that corneal basal cells are in a more differentiated state than limbal basal cells. These findings, coupled with the known centripetal migration of corneal epithelial cells, strongly suggest that corneal epithelial stem cells are located in the limbus, and that corneal basal cells correspond to "transient amplifying cells" in the scheme of "stem cells----transient amplifying cells----terminally differentiated cells."

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Differentiation-related expression of a major 64K corneal keratin in vivo and in culture suggests limbal location of corneal epithelial stem cells.

http://sun-lab.med.nyu.edu/files_private/sun-lab/attachments/1989.Cell.Cotsarelis-s.pdf

Existence of slow-cycling limbal epithelial basal cells that can be preferentially stimulated to proliferate: implications on epithelial stem cells.

A complete stereotaxic neuroanatomical atlas of the rat hindbrain was prepared using transverse serial sections stained with Luxol fast blue and cresyl violet. Catecholamine-containing cell bodies and fiber terminals were identified by the histofluorescence method. The acetylcholinesterase distribution was histochemically localized. A detailed stereotaxic atlas of the catecholaminergic and acetylcholinesterase-containing structures is presented.

Topographic atlas of catecholamine and acetylcholinesterase-containing neurons in the rat brain. I. Forebrain (telencephalon, diencephalon).

Three categories of phosphatase activity toward adenosine triphosphate at pH 9.4 have been isolated histochemically: (1) phosphatase which requires -SH groups; (2) phosphatase which is inhibited by -SH groups; and (3) phosphatase which is relatively indifferent to -SH groups. This enzymatic activity was demonstrated in thin (5 µ), unfixed, frozen sections.True adenosine triphosphatase has been separated histochemically by virtue of its -SH dependence. It was demonstrated in cardiac and skeletal muscle fibers and in the mitochondria of the kidney tubules. The staining of these structures can be prevented by treatment with an -SH inhibitor, such as p-chloromercuribenzoate or salyrganic acid. Also their stainability can be restored by reversing the inhibition of the enzymes with -SH compounds, such as BAL or cysteine. There was no reaction of these particular structures when adenosine diphosphate or adenosine-5-phosphate was used, suggesting that under the conditions of this histochemical test only the termi...

The specificity of the histochemical method for adenosine triphosphatase.

SummaryA histochemical method is presented for localizing ChE activity by incubating tissue sections in a medium containing acetylthiocholine, copper glycinate and copper thiocholine. Results obtained with several tissues containing specific ChE are described and illustrated.

A histochemical method for localizing cholinesterase activity.

Contribution to the Theory and Practice of Tonometry

IN RECENT years considerable knowledge has been added to our understanding of aqueous outflow. Although it had been known for many years that patients with chronic simple glaucoma had a decreased facility (increased resistance) of aqueous outflow,1it is through the recent efforts of Goldmann2and Grant3that these findings have been placed on a more quantitative basis. The facility of outflow is a coefficient representing the outflow in cubic millimeters per minute per millimeter of mercury pressure gradient. It is, therefore, a measure of the ease with which aqueous can leave the eye. Goldmann determined aqueous outflow and facility of outflow in the undisturbed eye by measuring the turnover rate of fluorescein in the anterior chamber (KF),4the volume of the anterior chamber (VA), and the difference between intraocular pressure (PO) and episcleral venous pressure (PV). Grant has calculated the facility

Clinical aqueous outflow.

THE CLINICAL phenomenon of so-called neuroparalytic keratitis has commonly been assumed to be the expression of some trophic disturbance in the cornea consequent upon sensory denervation of this tissue. The fact that the catastrophic events of such keratitis can be avoided by blepharoplasty and the prevention of the cornea from drying does not disprove such a trophic influence. The purpose of the present study was to see whether neuroparalytic keratitis could be produced experimentally in animals and to find out whether after sensory denervation there was any change in the mitotic or wound-healing activities of the corneal epithelium. Keratitis following injury to the trigeminal nerve has been reported by Zander and Weddell 1 in experiments on rabbits and monkeys and by Kotlyarevskaya 2 in cats. The latter author claims to have produced bilateral lesions following unilateral Gasserian ganglion injuries. In neither of these studies was the influence of sensory denervation

Jonas S. Friedenwald

Papers

A histochemical method for localizing cholinesterase activity.

Contribution to the Theory and Practice of Tonometry

Clinical aqueous outflow.

Mitotic and wound-healing activities of the corneal epithelium; effect of sensory denervation.

Aqueous Humor Dynamics