摘要:

Video fluorescein angiography has been used to evaluate retinal circulatory parameters in diabetic and non-diabetic Sprague-Dawley rats. Video fluorescein angiograms were recorded from the retina using a modified retinal fundus camera following a 5 ul bolus injection of sodium fluorescein dye into the jugular vein. Retinal circulatory parameters were measured using computer assisted image analysis. These analyses were performed on 25 diabetic rats with 1 week duration of diabetes and 26 matched, non-diabetic, rats. There was a significant (p-.0001) increase in retinal Mean Circulation Time (MCT) in the diabetic group (1.83±0.40 s) compared to the control group (1.09±0.27 s). There were no significant differences in arterial or venous diameters comparing diabetic and control groups. In a separate paired experiment, measurements were made from the same animals both before and after one week duration of diabetes. A paired t-test analysis demonstrated significantly increased MCT times in the 6 diabetic animals (p-.001) while there was no significant differences detected in the 4 corresponding control animals. These results indicate that significant increases in retinal circulation times can be measured as early as 1 week after strepto-zotocin induced diabetes in this animal model.

ISSN:0271-3683    

DOI:10.3109/02713689209001782

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

Because trabecular cell loss is thought to play a role in the pathogenesis of some forms of glaucoma, identification of factors which influence trabecular cell division may provide some insight into the mechanisms and potential treatment of this disease. We studied several commonly encountered clinical situations which may affect the trabecular meshwork: phagocytosis of debris, hyphema, and argon laser trabeculoplasty. The effect of these factors on trabecular cell division was determined using3H-thymidine autoradiography. Laser trabeculoplasty induced a 307% increase in–H-thymidine labelling of trabecular cells while phagocytosis and hyphema had no effect on cell labelling. In addition, subgroups of eyes with a loss of trabecular cells or with inflammation did not have increased labelling. Thus laser trabeculoplasty, known to increase outflow facility, was associated with increased trabecular cell labelling while factors often associated with decreased outflow facility and glaucoma were not.

ISSN:0271-3683    

DOI:10.3109/02713689209001783

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

The Neodymium (Nd):YAG laser is commonly used in ophthalmology mainly for the posterior capsulotomy in patients with secondary cataract after extracapsular cataract extraction. A frequent side-effect following different kinds of YAG laser treatments is an acute increase in the intraocular pressure (IOP). The present study addresses the role of calcitonin gene-related peptide (CGRP) in the ocular irritative response following YAG laser anterior capsulotomy in rabbits. The YAG laser anterior capsulotomy caused an irritative response in the eye, which consisted of an increase in the IOP, miosis and breakdown of the blood-aqueous barrier. Following YAG laser capsulotomy, CGRP-immunoreactivity was found in the aqueous humour in different molecular weight forms as revealed by gel-permeation chromatography. One of the peaks coeluted with synthetic human CGRP. Methysergide attenuated the increase in the IOP and disruption of the blood-aqueous barrier, but not the miosis, following YAG laser anterior capsulotomy. The present study demonstrates the release of CGRP into the aqueous humour following YAG laser capsulotomy, and suggests that CGRP is partly causing the increase in IOP and disruption of the blood-aqueous barrier in this irritative response.

ISSN:0271-3683    

DOI:10.3109/02713689209001784

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

In the current study, 35 pairs of corneas from asymptomatic carriers of HIV-1 and ten pairs from AIDS patients were analyzed for the presence of HIV-1 and HHV-6. The tissues were evaluated for viral antigens, transcripts, DNA sequences and intact and infectious virus. Three corneas from two asymptomatic carriers of HIV-1 and three corneas from two AIDS patients were culture positive for HIV-1. One of the three HIV-1 positive corneas from an asymptomatic HIV-1 carrier also was culture positive for HHV-6. Two of the tissue culture positive corneas from asymptomatic HIV-1 carriers and two from AIDS patients also tested positive for HIV-1 transcriptional activity byin situhybridization. The label denoting the transcriptional activity was limited to stromal keratocytes. Most significantly, we were able to demonstrate the presence of HIV-1 particle(s) in sections and cultured PBMC from one of the HIV-1 culture positive corneas. PBMC from the same cornea also contained herpes virus particles. This report strengthens our earlier findings that HIV-1 and HHV-6 can invade corneal tissue, which emphasizes the importance of vigorous screening of corneal donors, specifically donors with HIV-1 exposure.

ISSN:0271-3683    

DOI:10.3109/02713689209001785

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

The effects of intravitreal and intracameraJ administration of endothelin-1 were studied in the anaesthetized cat. Intravitreal injection of 0.4 nmol endothelin-1 induced a 34±10% (n=5; P<0.05) reduction in retinal blood flow in the experimental eye compared to the control eye 80 minutes after the injection. Blood flow in the ciliary body, iris and choroid remained unaffected by the injection of endothelin-1.Intracameral administration of endothelin-1 at pmol doses caused a reduction in pupil size, an increase in the aqueous humor protein concentration (indicating a break-down of the blood-aqueous barrier) and an increase in the concentration of prostaglandin E2 in the aqueous humor. The effect of endothelin-1 on pupil size was abolished by indomethacin pretreatment, indicating that this effect was mediated by arachidonic acid metabolites.

ISSN:0271-3683    

DOI:10.3109/02713689209001786

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

The production and spatial organization of connective tissue components 1n ciliary muscle cell cultures was studied with immunohlsto-chemlcal and ultrastructural methods. Antibodies against collagen types IV and VI, flbronectln and laminin were used.Laminin stains as pericellular network surrounding Individual muscle cells. Type IV collagen shows positive cytoplasmic staining and only small fod of extracellular Immunofluorescence. Staining for type VI collagen and flbronectln 1s seen near the ends of the bipolar cells, while the lateral sides of the cells remain unstained.Electronmlcroscopy shows that cultured ciliary muscle cells are surrounded by an Incomplete basal lamina. In addition, bundles of 5–20 nm thick extracellular microfibrils are seen. The bundles are oriented parallel to the axis of the cells and are 1n close contact with the cell membrane 1n areas where membrane-bound dense bands are formed. Immunoelectronmlcroscopy Indicates that the bundles contain flbronectln and type VI collagen fibrils. While the flbronectln fibrils approach the cell membrane directly, type VI collagen fibrils are usually separated from the cell membrane by fine fibrinous material of different nature. Quality and spatial organization of the extracellular material 1n ciliary muscle cell cultures shows marked similarities with the extracellular matrix of ciliary muscle 1n situ.

ISSN:0271-3683    

DOI:10.3109/02713689209001787

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

The pseudoexfoliation (PSX) syndrome has long been speculated to be a disorder of disturbed basement membrane metabolism. To test this concept, we investigated the presence of all principal basement membrane components in precapsular PSX deposits of 30 anterior lens capsules by immunofluorescence and electron microscopic immunogold techniques. We have shown heparan sulfate and chondroitin sulfate proteoglycans, laminin, entactin/nidogen, fibronectin, and amyloid P protein to be an integral constituent of PSX material; type IV collagen was restricted to a microfibrillar layer interposed between capsular surface and typical PSX material. The additional presence of elastin epitopes indicates that the PSX material is a multicomponent expression of a disordered extracellular matrix synthesis including the incorporation of the principal noncollagenous basement membrane components. The extensive labelling of PSX material for chondroitin sulfate suggests an overproduction and abnormal metabolism of glycosaminoglycans to be one of the key changes in this disorder.

ISSN:0271-3683    

DOI:10.3109/02713689209001788

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

Recent advances in understanding the mechanism of selenite cataract have resulted from locating the cleavage sites on proteolyzedβ-crystallins from the cataract, mimicking the insolubilization of crystallins found in the cataract in an in. vitro system, studying cataract produced in lenses cultured in selenite, and permanently or temporarily reducing the rate formation of selenite cataract by use of various inhibitors. The present review discusses the selenite cataract as a useful model for understanding the role calcium-induced proteolysis in cataract formation.

ISSN:0271-3683    

DOI:10.3109/02713689209001789

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

The induction of T cell mediated disease models in animals is usually dependent on the use of complete Freund's adjuvant (CFA). In order to avoid the painful side effects of CFA on the animals, we tested the capacity to induce experimental autoimmune uveoretinitis (EAU) with Hunter's adjuvant (HA). This new adjuvant makes use of nonionic copolymer surfactants, and does not cause deleterious effects to animals. We have found that EAU could be efficiently induced in rats with low doses of S-Ag (10 ug) in very small quantity of HA (10 u.l). The biologic parameters of EAU induction showed a potent stimulation of lymphocytes proliferation maximal 11 days after immunization, as well as high levels of antibody production.

ISSN:0271-3683    

DOI:10.3109/02713689209001790

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

Aldehyde dehydrogenase has recently been shown to be one of the major soluble proteins in the mammalian cornea. The enzyme has a subunit molecular weight of 54 kd and gel filtration experiments indicate that a dimer molecule is the enzymatically active species.The purpose of the studies described here was to investigate whether oligomeric forms of this enzyme could also be detected using the much faster SDS-PAGE mini-gel electrophoresis technique combined with immunoblotting and“in gel”enzyme detection.Low temperature treatment of samples prior to electrophoresis revealed that both human and bovine corneal ALDH are mainly present as a 54 kd and as a dimer molecule with an apparent molecular weight of 88 kd. Bovine corneal ALDH also contained larger oligomers with a molecular weight of 110, 154 and 210 kd respectively.The classical 3 minutes boiling procedure prior to SDS-PAGE dissociated the oligomers into the 54 kd subunit. Zymography experiments showed that enzyme activity was only present in the 88 kd form of corneal ALDH. Pretreatment of corneal ALDH at various temperatures showed that the temperature induced shift of the 88 kd species to the 54 kd subunit parallelled the decrease in enzymatic activity. The fact that reduction of samples with DTT did not dissociate the 88 kd form suggests that disulfide bridge formation is not involved in the oligomerisation of corneal ALDH.

ISSN:0271-3683    

DOI:10.3109/02713689209001791

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor