Biomedical subjects
Publications and source records attributed to O Schmut.
The disappearance of a Kayser-Fleischer ring induced by the administration of penicillamine (D-penicillamine) for 17 years is described. The ring disappeared only in the lateral and medial portions leaving superior and inferior crescents. Possible mechanisms of this partial regression of the ring ae discussed.
Serum HDL cholesterol concentrations were measured in patients with ocular diseases. Patients with occlusions of the retinal arteries had significantly lower HDL cholesterol values than a control group.
Using radial immunodiffusion it is possible to identify and to quantitate antithrombin III in human aqueous humor. The importance of antithrombin III as a cofactor of heparin is stressed.
From pepsin-solubilized vitreous body collagen three different precipitates were collected by differential salt precipitation. These three different protein fractions contain hydroxyproline and show different patterns in polyacrylamide gel electrophoresis suggesting different collagen types.
Reductions with [3H5NaBH4 proof that the decrease in viscosity of hyaluronic acid solutions caused by lowering the pH does not depend on a depolymerisation of hyaluronic acid. At the same time investigations at different pH-values, show a sigmoide increase of the Spin-Lattice-Relaxationtime T1. This increase depends on a progressive aggregation of the hyaluronic acid molecule. The effect seems to be induced by the decrease of ionization of the carboxylgroups, by acidification of the solution.
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Bovine cornea, sclera, iris, ciliary body, choroid, zonular fibers, lens capsule, lens nucleus, vitreous body, and retina were investigated for collagen content and type. Cornea, sclera, iris, ciliary body, choroid, lens capsule, and vitreous body contain hydroxyproline, whereas in zonular fibers, lens nucleus, and retina no hydroxyproline was detectable. Preparative isolation of collagen was achieved by digestion of the different eye tissues with pepsin. The pepsin-solubilized collagen was separated by differential salt precipitation into different collagen types. The polyacrylamide gel electrophoresis of the pepsin-solubilized collagens revealed type I collagen in cornea, sclera, iris, ciliary body, and choroid. As well as type I collagen, type III collagen was isolated from cornea, sclera, and uveal tissues. The identification of types I and III collagen was supported by the CNBr-derived peptides of these collagens. Lens capsule collagen consisted mainly of type IV collagen. Zonular fibers contained no hydroxyproline but when examined by polyacrylamide gel electrophoresis, a band migrating in the alpha-position of collagen was observed. Polyacrylamide gel electrophoresis of both the pepsin-solubilized component and the CNBr-derived peptides of vitreous body protein showed no relation to any of the four common collagen types.
Fe(II)-ions reduce the viscosity of a hyaluronic acid solution but do not form a precipitate. Fe(III)-ions only slightly lower the viscosity of hyaluronic acid solutions but cause a brown, water-insoluble iron-hyaluronic acid precipitate. After adding ascorbic acid--concentrate the pH-value as in vitreous body--to the reaction solution, Fe(III)-ions reduce the viscosity too. The iron-hyalurnic acid complex is also destroyed by ascorbate. Therefore, the ascorbate of the vitreous humor plays an important role in the generation of siderosis bulbi.
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Pepsin-soluble collagen was isolated from bovine vitreous humor. This collagen showed only one alpha-chain in disc electrophoresis, migrating in the alpha1-chain position and between the alpha- and beta-components some colored bands were visible. The disc electrophoretic patterns of the cyanogen bromide peptides of pepsin-soluble vitreous body collagen and pepsin-soluble type II collagen revealed no identity.
Electron microscopic investigations show that intravitreal application of EDTA causes destruction of the viteous body and damage in all layers of the retina. Therefore, it is concluded that it is useless to try prevention of metallosis of the eye by EDTA.
After sensitization of a rabbit with soluble human cornea proteins a hetero-keratoplasty (man-rabbit) is performed with exactly determined antibody titer. Light-microscopic investigations showed that the epithelium of the transplant is involved in this severe humoral immune-reaction mainly. In the area between receptor's and donor's cornea impressive changes could be observed.
Ultrastructural changes of the receptor's cornea of a rabbit by experimentally induced immune-reaction were communicated. The finding of plasma-cells proves the generation of humoral antibodies. Granulocytic elements are shown in the transplant or react with diffusing antigen-antibody-complexes already in the stroma of the receptor's cornea.
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Purified hyaluronic acid of ox vitreous humour was isolated treating the acetone precipitate of a vitreous humour homogenate with 1 M NaCl solution and thereafter with cetylpyridiniumchloride. Both disc-electrophoresis and hydroxyproline content proved the absence of collagen in the purified hyaluronic acid. FeSO4, ascorbate, and cysteine changed the hyaluronic acid molecule and lowered the viscosity of the hyaluronic acid solution, EDTA alone did not affect the viscosity but enhanced the effectiveness of iron ions or ascorbate on the viscosity of the solution. Catalase prevented the reduction of the viscosity by the above mentioned substances. Therefore, it is suggested that H2O2 and free radicals are generated during the reaction. The free radicals produced are responsible for the change of the hyaluronic acid molecule.
Vitreous body fibrils and zonula fibers are analyzed by disc-electrophoresis. In both tissues the presence of collagen is established. The disc-electrophoresis patterns of vitreous body fibrils and zonula fibers show that a different type of collagen is present in each tissue. The absence of the alpha 2-chain indicates that the tissues investigated contain no type I collagen but types consisting of three identical alpha-chains.
It is possible by means of various immunological methods to identify more than 15 proteins in the human aqueous humour. Quantitative methods permit the determination of the concentrations of these proteins in the aqueous humour. The absence of high molecular weight proteins shows that the aqueous humour mainly consists of an ultrafiltrate of serum.