摘要:

Retinal interphotoreceptor retinoid-binding protein (IRBP) is a potent uveitogen in Lewis rats, producing experimental autoimmune uveitis (EAU) reproducibly at doses lower than those of S-antigen (S-Ag). In contrast, IRBP was found to be poorly uveitogenic in three strains of guinea pigs, inducing only minor changes in a small proportion of these animals. On the other hand, S-Ag was found to induce EAU in the majority of immunized guinea pigs, with changes more severe than those induced by IRBP. Unlike the difference in their uveitogenicity, IRBP and S-Ag induced similar levels of specific immune responses in the immunized guinea pigs. The poor uveitogenicity of IRBP in guinea pigs resembles that of A-antigen (A-Ag). The two proteins are also similar in other features and were found in this study to be antigenically identical. It is proposed that IRBP and A-Ag are one and the same protein.

ISSN:0271-3683    

DOI:10.3109/02713688709025196

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

Aqueous protein content was estimated as a measure of the integrity of the blood-aqueous barrier after paracentesis or argon laser photocoagulation of the iris in rabbits. Corticosteroid pretreatment topically or by subconjunctival or intramuscular injection exerted only a moderate inhibitory effect on the breakdown of the bloodaqueous barrier. Instillation of 0,1% indomethacin however, strongly inhibited the response in both models. The results are indicative of the potential usefulness of topical administration of prostaglandin synthetase inhibitors in the treatment of non-infectious inflammatory diseases.

ISSN:0271-3683    

DOI:10.3109/02713688709025197

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

Aldose reductase was prepared from a pool of 21 male and 16 female human retinas by ammonium sulphate fractionation (40–75% saturation) and chromatography on DEAE-Sephacel and Matrex-OA. The overall purification was 132-fold with 50% recovery of enzyme activity.The concentrations of the aldose reductase inhibitors Sorbinil, Statil and M79175 required to give 50% inhibition (IC50value) of enzyme activity with the model substrate 4-nitrobenzaldehyde (4NB) were 3.4μM, 2.3μM and 0.22μM respectively. This indicated that M79175 was the most effective inhibitor tested of aldose reductase with 4NB in vitro. These inhibitors were more effective when tested against aldose reductase activity with glucose, the substrate which might play a role in the pathogenesis of diabetic complications. Sorbinil gave an IC50(glucose) of 0.40μM; M79175 and Statil were more effective. At an inhibitor concentration of 0.1μM the %-inhibitions observed were: Sorbinil 20% M79175 55%, Statil 76%. Thus Statil was the most potent compound tested against human retinal enzyme using the more physiological substrate in vitro.This report provides the first direct evidence that human retinal aldose reductase is susceptible to inhibition by compounds designed for chemotherapy of diabetic complications, and indicates that the concentrations of inhibitor required for a substantial block of activity in vitro are lower than those attained in plasma in man.

ISSN:0271-3683    

DOI:10.3109/02713688709025198

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

Morphologic alterations in cortical fiber cell membranes of the developing Emory mouse cataract were studied with scanning, transmission and freeze-fracture electon microscopy. Scanning electron microscopy revealed the extensive formation of prominent ridges on the surfaces of normal-appearing fibers, greatly enlarged degenerating fibers and globular structures in the relatively superficial cortical regions of the cataractous lenses where such a surface pattern was not found in the normal controls. Transmission electron microscopy showed undulating 13 nm pentalamellar structures, which were thinner than 17 nm heptalamellar (or pentalamellar) structures of gap junctions, were distributed within the cell membranes having ridge patterns. Some globular structures were encircled by repeated undulating 13 nm pentalamellar structures and multi lamellar membranes. Freeze-fracture studies demonstrated that 13 nm pentalamellar structures consisted of square crystalline arrays of 6 nm intramembrane particles whereas 17 nm heptalamellar profiles showed randomly-packed 9 nm intramembrane particles of typical lens fiber gap junctions. It is suggested that the extensive formation of ridges in the relatively superficial cortical regions of the Emory mouse lenses may be associated with a degenerative process of lens fiber cell membranes during cataractogenesis.

ISSN:0271-3683    

DOI:10.3109/02713688709025199

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

Post-mortem human vitreous samples (liquid and gel) of comparable intrinsic viscosity values (n=3000 cc/g) were chromatographed on DEAE-Sephacel columns at 4°C using a linear salt gradient ranging from 0±0.4M NaCl. All samples examined produced numerous discrete hyaluronic acid (HA) fractions. The HA fractions from liguid vitreous were eluted at lower salt concentrations than those from gel vitreous. Several HA fractions from vitreous analyzed by circular dichroism (CD) displayed CD minima at 210 nm, with an ellipticity value of 14 to 16×103deg cm2d mole-1. However, all HA fractions from liguid vitreous showed lower ellipticity values and a weak positive signal above 240 nm. This signal was absent in HA fractions from gel vitreous. Results suggest that subtle but definite conformational differences involving carboxylic groups exist between gel and liguid vitreous hyaluronate.

ISSN:0271-3683    

DOI:10.3109/02713688709025200

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

Rabbit lenses were incubated in organ culture with14C-galactose for 6, 12 and 20 hours. Gangliosides were extracted using the Folch-Suzuki method, purified by dialysis and analyzed by thin-layer chromatography. Six radioactive bands, including the origin, were observed. Tentative identification of these bands as N-acetylneuraminylgalactosyglucosyl-ceramide (GM3), N-acetylgalactosaminyl-(N-acetylneuraminyl)-galactosylglucosylceramide (GM2), galactosyl-N-acetylgal-actosaminyl-(N-acetylneuraminyl)-galactosylglucosylceramide (GM1), N-acetylneur-aminylgalactosyl-N-acetylgalactosaminyl-(N-acetylneuraminyl)-galactosylglucosyl-ceramide (GD1a), N-acetylneuraminylgalactosyl-N-acetylgalactosaminyl-(N-acetylneuraminyl-N-acetylneuraminyl) -galactos-ylglucosylceramide (GT) was made by comparison with authentic standard gangliosides. Galactose incorporation into GM3and GM2increased during the first 12 hours but decreased during the period from 12 to 20 hours. GD1aand GTincorporated the greatest amount of label during the period from 12 to 20 hours. Incorporation of labeled galactose into GM1was nearly constant during this time period. Specific activities for GM1GM3and GTwere nearly the same at 6 hours and were about half those of GM2and GD1afor the same time period.

ISSN:0271-3683    

DOI:10.3109/02713688709025201

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

Dark adapted and progressively light adapted electroretinograms (ERGs) were recorded from 34 normals and from 45 glaucoma patients. To enhance the oscillatory potentials (OP) the ERGs were highpass-filtered. The OP were characterized by two indices: their root-mean-square value and the inter-flash interval for which the maximal amplitude was obtained. In most of the glaucomatous OP, 50 of 81 eyes, both indices were abnormal, in 22 one parameter was abnormal and only in 9 were both parameters normal. In 13 of the 14 OP recorded from the opposite (‘normal’) eye of patients with unilateral glaucoma either one or both of the indices were abnormal. These findings indicate that the damage to the retina in glaucoma may extend more distally than the ganglion cell layer and that subclinical changes might be revealed by OP changes.

ISSN:0271-3683    

DOI:10.3109/02713688709025202

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

Autoantibodies against corneal epithelium antigens are frequently found in patients with corneal diseases, but also in patients with uveitis. To investigate whether these autoantibodies play a primary role in the pathogenesis of corneal disease we studied the distribution of a 54 kD corneal antigen (isolated in a previous study) within the eye. Animal experiments were performed to determine the accessibility of this antigen by its corresponding antibody. Immunohistochemistry showed that the 54 kD corneal antigen was abundantly present in the rat corneal and conjunctival epithelium. A high concentration of this antigen was seen just above the nuclei in the basal cell layer of the corneal epithelium. The antigen could also be detected in the keratocytes of the corneal stroma, the corneal endothelium and the lens epithelium. The 54 kD corneal antigen was not detected in other parts of the eye, nor could it be found in the rat liver, kidney, spleen, lung or skeletal muscle. Incubation of intact rat eyes with antiserum against the 54 kD corneal antigen in vitro, resulted in a weak binding of immunoglobulins to the corneal surface epithelium cells. Passive transfer experiments, whereby rats received an intravenous injection of antiserum against the 54 kD corneal antigen resulted in a weak deposition of immunoglobulins in the corneal stroma and sclera. However, no antibodies were bound to the corneal epithelium. These observations show that although antibody production to corneal epithelium antigens is easily triggered, these antibodies do not reach the corneal epithelium.

ISSN:0271-3683    

DOI:10.3109/02713688709025203

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

Activity of RNA polymerases I, II and III (distinguished usingα-amanitin) and activity of DNA polymerasesαandβ(distinguished using N-ethylmaleimide) were assayed for varying intervals and at varying substrate (UTP or dTTP) concentrations in the purified nuclear fraction from corneal epithelium of carbamylcholine-treated and control eyes of rabbits with resurfacing acid burn defects. Incorporation was linear with time for all enzymes up to 30 min. In 10 min assays at varying substrate concentrations, all polymerases from carbamylcholine-treated eyes had significantly elevated Vmax compared to corresponding control enzymes. The drug also increased apparent affinity of RNA polymerase II for UTP and apparent affinity of DNA polymerases a and 3 for dTTP. Results are discussed in relation to potential mechanisms by which effects of carbamylcholine on polymerase activity may be mediated.

ISSN:0271-3683    

DOI:10.3109/02713688709025204

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

Stimulation of lens fiber cytoskeletal phosphorylation by adrenergic drugs is described. The effect of isoproterenol on phosphorylation of the 47Kd beaded filament protein is dose-dependent, detectable as soon as one minute after treatment and blocked by propranolol. Epinephrine increases the phosphorylation of both 47Kd and the intermediate filament protein, vimentin. 47Kd phosphorylation is also increased by norepinephrine, dibutyryl-cAMP or forskolin. The results indicate that lens fiber cytoskeletal phosphorylation is regulated, at least in part, via a beta-adrenergic receptor coupled to cyclic AMP production.

ISSN:0271-3683    

DOI:10.3109/02713688709025205

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor