I. Brettschneider

Heterogeneity of the bovine corneal collagen

Abstract Type III collagen [α1 (III)] was isolated from the pepsin-solubilized bovine corneal collagen either by differential salt precipitation, or by molecular sieve chromatography. It has been estimated that type III collagen represents about 20% of the total collagen, the predominant part of which is type I collagen. The identity of type III collagen was verified by molecular sieve chromatography and polyacrylamide gel electrophoresis of reduced and alkylated γ-chains, and by CNBr cleavage and amino acid analysis of isolated α1 (III) chains.

Glycosaminoglycans in Embryonic and Postnatal Human Cornea

Human corneas were analyzed for glycosaminoglycans during various stages of embryonic development and at different postnatal ages. The development and aging of the cornea was accompanied by a transient increase of glycosaminoglycan hexosamine up to 2 years of age and thereafter by a stepwise decrease to a value which seemed to be constant in all age groups. Keratan sulphate formed a minor part of glycosaminoglycans in fetal, premature and newborn corneas but it predominated in older corneas. The development of the cornea was characterized by a decrease in sulphation of chondroitin sulphate. No hyaluronate was found in the fetal corneas available for this study.

Glycosaminoglycans in the Developing Chicken Cornea

The development and aging of the chicken cornea is accompanied by the stepwise disappearance of the non-sulphated glucosaminoglycan and by the increase of keratan sulphate and chondroitin sulphate con

Tetracycline Hydrochloride and Lens Changes

Intensive topical administration of tetracycline hydrochloride by means of hydrophilic contact lenses resulted in lens changes – opacities and coloration – in young rabbits. The presence of TTC deposi

Penetration of Radioactive Sulphate and Glucose from Hydrophilic Gel Contact Lenses into the Eye of the Rabbit

Soft poly(hydroxyethylmethacrylate) gel contact lenses soaked with a solution containing either radioactive sulphate or D-glucose-14C were applied to the rabbit eyes for time intervals rang

The dissolution or retention of acid mucopolysaccharides (AMPS) of the rabbit cornea after long-term fixations in various fixation fluids

Extraction or retention of acid mucopolysaccharides (AMPS) of rabbit cornea after long-term fixations in various fixation fluids was investigated. The corneae were fixed 21 days with formol-cetylpyridinium chloride (CPC) at 19 and 28°C, and with formol-calcium chloride, Lillies fluid and Carnoys fluid at 19°C. AMPS were examined histochemically by staining with Alcian blue, colloidal Fe3+ and with toluidine and methylene blue, as well as biochemically by determination of the total hexosamine and glucuronic acid content. Besides that after each fixation stroma hydration was determined. Of all fixatives used a considerable AMPS loss into the fixation fluid was found only following formol-calcium chloride fixation. Intensity of histochemical stainings for AMPS was mostly dependent on hydration of the corneal stroma and was insignificantly influenced by the actually decreasing content of AMPS in tissue. Die Extraktion oder Aufbewahrung von sauren Muccopolysacchariden (AMPS) der Kaninchenhornhaut nach langdauernder Fixation in verschiedenen Fixationslösungen wurde untersucht. Die Hornhäute wurden 21 Tage in Formol-Cetylpyridinium chlorid (CPC) bei einer Temperatur von 19 und 28°C und in Formol-Calciumchlorid, Lillies Lösung und Carnoys Lösung bei 19°C fixiert. AMPS wurde nach Alcianblau, colloidal Fe3+ und Toluidin und Methylenblau Färbung histochemisch untersucht. Biochemisch wurde der Gesamtgehalt von Hexosamien und Glukuroniksäure festgestellt. Außerdem wurde die Hydratation des Hornhautstromas nach jeder Fixation bestimmt. Ein beträchtlicher Verlust von AMPS in die Fixationslösung wurde von allen Fixativlösungen nur bei Formol-Calciumchlorid gefunden. Die Intensität der histochemischen Färbungen für AMPS hängt hauptsächlich von der Hydratation des Hornhautstromas ab und wurde durch den wahren Verlust des AMPS-Gehaltes in Gewebe nur geringfügig beeinflußt.

Eye Changes Due to Systemic Use of Tetracycline in Pregnancy

Discoloration of the cornea, sclera and lens was observed for the first time in newborn rats as a complication of intramuscular use of tetracycline in pregnancy. Fluorescence microscopic examination with UV light revealed tetracycline deposits located mostly in the corneal epithelium, Descement’s membrane, lens capsule, cortex and nucleus.

Intraocular Penetration of Bacitracin and Polymixin B after Administration by Means of Hydrophilic gel Contact Lenses

Hydrophilic contact lenses made of poly(hydroxyethylmethacrylate) gel were saturated with 1-percent [14C]-glycyl-bacitracin or 0.1 -percent[14C]-glycyl-polymixinBand then applied

Changes of Glycosaminoglycan Sulphation in the Cornea of Lathyric Chick Embryos

Lathyrogen β-aminopropionitrile and radioactive sulphate were administered to 15-day-old chick embryos by injection into allantoic cavity. On consecutive days, experimental lathyrism was evidenced by a decrease of the tensile strength of the neck of the chick embryos and by the inhibition of radioactive sulphate incorporation into corneal stroma and nasal cartilage. After the chromatographic separation of corneal glycosaminoglycans, it was found that β-aminopropionitrile specifically lowered the sulphation of galactosaminoglycan with radioactive sulphate by about 30% compared with the control, whereas the sulphation of glucosaminoglycan remained unchanged.

Glutaraldehyde Fixation of Corneal Acid Mucopolysaccharides

(1) 24 hours fixation of rabbit corneae with 6% glutaraldehyde-sodium phosphate was without any significant effect of the corneal acid mucopolysaccharides (AMPS) estimated by the determination of hexo