Development of electroretinographic alterations in 9-week-old experimental diabetic rats was studied for up to 6 weeks after a single intraperitoneal injection of streptozotocin (STZ, 60 mg/ kg). The amplitudes and the peak latencies of the a and b waves in the diabetic rats did not differ significantly from those in the control rats. In contrast, the diabetic rats showed a significantly smaller amplitude of the second oscillatory potential (OP) 6 weeks after STZ treatment, and furthermore significantly delayed OP peaks as early as 2–3 weeks after STZ treatment. Vitreous fluorophotometric abnormality developed 6 weeks after STZ treatment. None of the diabetic rats had fundus angiographic changes. These results suggest that hyperglycemia or its related changes rapidly affects the light-induced electrical activities of the retina.
Aims-To assess the effects of the cytokines, interleukin-1 (IL-1), IL-1 receptor antagonist (IL-Ira), transforming growth factor-r 2 (TGF-P2) and basic fibroblast growth factor (b-FGF), on the mitosis of and coliagen synthesis by lens epithelial cells (LECs) (Br_J Ophthalmol 1996; 80: 63-68) Residual lens epithelial cells (LECs) proliferate in a defective lens capsule after cataract surgery, resulting in secondary cataract. They can also undergo fibrous metaplasia and produce collagen, resulting in capsular fibrosis that represents a form of secondary cataract. We reported previously that cultured human cataract LECs obtained by anterior capsulotomy during cataract surgery produce interleukin-1 (IL-i),l IL-6,2 IL-8 (unpublished data), basic fibroblast growth factor (b-FGF),3and transforming growth factor-( (TGF-P) (unpublished data) in the incubation medium. Cytokines act generally in an autocrine or paracrine manner on the target cells. In this paper, we examined the effect of the cytokines, IL-1, IL-1 receptor antagonist (IL-lra), TGF-P2 and b-FGF, on the proliferation of and collagen synthesis by human cataract LECs in culture. Materials and methodsAs an indicator of the mitosis rate of the LECs and their collagen synthesis rate, the uptake of 3H-thymidine and 3H-proline by the cells was measured. The uptake by the LECs when a cytokine at various concentrations was added to the culture was compared with that of the controls without addition of any cytokine. CULTURE OF HUMAN CATARACT LECSHuman cataract LECs were cultured as previous described.' Briefly, a circular piece of the anterior capsule with LECs attached was obtained by capsulotomy during cataract surgery and cultured directly without dispersion of the cells. After circular capsulorhexis, the piece of capsule, about 5 mm in diameter, was touched with an irrigation/aspiration tip and withdrawn from the eye by aspiration. The piece of capsule was held with fine forceps and washed thoroughly with irrigating solution. Each piece of anterior capsule was placed immediately into a well of a 48 well, multiwell plate containing 0 5 ml of Eagle's minimum essential medium (MEM) supplemented with 10% fetal calf serum (FCS), penicillin G at 100 U/ml, and streptomycin sulphate at 100 pug/ml and then cultured in 100% humidity at 37°C in a 50/o carbon dioxide atmosphere. The medium was changed weekly. The specimens from patients aged between 55 and 69 years were used for the entire experiment.
The dry eye syndrome is a chronic disease which can become a serious threat to useful vision. However, there is only a limited understanding regarding effective treatment or prevention of this disease. Establishing an effective mode of treatment requires the use of a satisfactory animal dry eye model. Ideally, such a model should rapidly determine the effectiveness of agents that inhibit the damaging effects of this syndrome. This paper presents a short-term dry eye model using rabbits, which combines mechanical prevention of blinking and methylene blue staining. This model is not intended to be a precise representation of the dry eye syndrome, since this disorder has recently become recognized to involve a primary pathological process of the corneal and conjunctival epithelium. However, by using this model, clinical signs of dry eye can be observed after a few hours in the form of acute desiccation. Corneal damage can easily be evaluated both qualitatively by methylene blue staining scores, and quantitatively by chronic assay. Visually observed corneal epithelial thinning was confirmed by scanning electron microscopy (SEM) to be due to loss of epithelial integrity. Using a 3% chondroitin sulfate solution, an already proven effective agent for dry eye, this model effectively demonstrated an 80% inhibition in the development of methylene blue positive lesion after a period of only 2 hours. This short term dry eye model is valuable in primarily screening the efficacy of potential therapeutic agents in the prevention and treatment of dry eye.
Results-Collagens I, IV, V, and VI were positive in the cultured cells. Types IV and V were strongly present in almost all the cells whereas types I and VI were only observed in a few cells. Collagens II and III were negative. Conclusions-Since the lens capsule is known to be comprised of collagen IV, collagens I, V, and VI seem to be produced newly in culture. The capsular fibrosis seen after cataract surgery in vivo as a wound healing process ofthe lens capsule, may contain these types of collagens. The present culture model is useful for studying secondary cataract formation. (BrJr Ophthalmol 1995; 79: 939-943)
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.