摘要:

A mounting block for in vitro perfusion of the cat cornea is described. Using this apparatus and the techniques of Araie, the permeability (Pac) of the normal cat corneal endothelium to carboxyfluorscein was determined to be 2.5 plusmn; 0.2×10-4cm/min. To assess the sensitivity of this technique in determining changes in Pacassociated with alterations in endothelial, morphology, three cats underwent 2 successive unilateral, central, 10 mm diameter circular areas of endothelial debridement 6 weeks apart. Six weeks following the second wounding all 3 animals underwent morphometric analysis and Pacdetermination. A trend toward an elevation in Pacwith extreme reductions in cell density was observed.

ISSN:0271-3683    

DOI:10.3109/02713689009003468

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

The ocular inflammatory activity following different techniques of lens extraction and vitrectomy was studied in rabbits recovered from primary uveitis. Primary uveitis was induced by intravitreal injection of human serum albumin. After five to ten weeks, when the eyes were completely quiet, vitrectomy combined with lensectomy in one session or extracapsular lens extraction followed by vitrectomy was performed in different groups of rabbits. The most intense postoperative inflammatory process was encountered following removal of the lens independently of the route of extraction (via the ciliary body or via the anterior chamber). Vitrectomy via the ciliary body led to a minimal postoperative inflammation which resolved within 7 days.From these results we concluded that vitrectomy in primarily sensitized rabbit eyes can be performed without intense postoperative complications.

ISSN:0271-3683    

DOI:10.3109/02713689009003469

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

The eye enjoys a privileged immunological status, in contrast to most sites in the body. Historically, it was thought that the eye, due to its lack of lymphatics, was not subject to the same immune surveillance as other tissues. In opposition to this, recent study has revealed that presenting foreign material via the eye produces marked effects on systemic immunity, leading to a state of tolerance when the same foreign antigen is presented systemically. The immunology of the eye is now known to consist of a myriad of local and systemic effects.

ISSN:0271-3683    

DOI:10.3109/02713689009003470

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

The effects of a series of taurine analogues on the accumulation of45calcium ions in a crude rat retinal membrane preparation are reported.45Calcium ion accumulation was measured at high (1.4 mM) calcium ion concentration in the presence and absence of ATP. In the absence of ATP, taurine andα-sulfo-β-ala-nine both inhibit45calcium ion accumulation.α-Sulfo-β-alanine is the more potent of the two compounds (50% vs. 30% inhibition at 20 mM). Thetransaminocycloalkanesulfonic acid analogues of taurine [(±)trans-2-aminocyclopen-tanesulfonic acid and (±)trans-2-aminocyclo-hexanesulfonic acid] are stimulators (3- to 4-fold) of45calcium ion accumulation. In the presence of ATP (1.2 mM), taurine and the analogues of taurine had no effect. Structure-activity-relationships of these compounds pertinent to their effects on45calcium ion accumulation at a high calcium ion concentration and in the absence of ATP are discussed. In addition, the inhibitory effects of taurine on45calcium accumulation in subfractions of the retina (rod outer segments, synaptosomes, and mitochondria) and the effects of the divalent ionophore A23187 on45calcium accumulation were also investigated.

ISSN:0271-3683    

DOI:10.3109/02713689009003471

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

The sclera in myopic regions of chick eyes was studied histologically and compared to the sclera in corresponding regions of normal fellow eyes. Chicks had been monocularly deprived of form vision in the nasal half of the retina from hatching. The fellow control eye and the temporal retina of the deprived eye had normal vision. With this treatment, the resulting form-deprivation myopia and eye enlargement are restricted to the retinal region that had been form deprived. We found that the cartilaginous sclera in the myopic nasal region exhibited several differences from that in the corresponding non-myopic region: it was thicker, its cell density was lower, and the number of chondrocytes and binucleate cells was higher. In contrast, the fibrous sclera was thinner. These changes suggest that form-deprivation myopia causes an increased production of extracellular matrix and an increased level of mitotic activity in the cartilaginous sclera. As expected, the non-myopic temporal regions of experimental and control eyes did not differ in any of these parameters. The findings of the present study suggest that the eye enlargement accompanying form-deprivation myopia is not the consequence of scleral stretching but of abnormal growth.

ISSN:0271-3683    

DOI:10.3109/02713689009003472

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

Corneal epithelial, fibroblast and endothelial cells, cultured from human donors, were analyzed to determine their characteristic phospholipid profiles by31P NMR. Tissue phospholipid profiles from epithelial, fibroblast and endothelial cell cultures were evaluated to differentiate the individual cell types and to identify resonances that typically appear in high-resolution phospholipid profiles of whole corneas. Phosphatidylcholine, phosphatidyl-ethanolamine plasmalogen, an uncharacterized phospholipid at 0.13 5, phosphatidylinositol, phosphatidylserine and sphingomyelin were determined to be, in decreasing order of concentration, the major phospholipids detected in these three cultured corneal cell types. Indices of phospholipid metabolism representing total plasmalogen content, total choline-containing lipids and the total choline-containing lipids less those synthesized through the plasmalogen pathway were found to differentiate the three cell types. Minor phospholipids cardiolipin, lysophosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine (LPC) and LPC plasmalogen not usually reported in studies of corneal phospholipids using other techniques, were useful in discriminating between cell types. Phospholipid profiles of the whole cornea provide important information concerning the biochemistry and pathology of the tissue, however, phospholipid analysis of individual components of the cornea, such as the epithelial, fibroblast and endothelial cells, makes it possible to understand the contribution of specific cellular constituents to the spectral information obtained from the whole cornea.

ISSN:0271-3683    

DOI:10.3109/02713689009003473

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

Interphotoreceptor retinoid binding protein (IRBP) is a 136,000 molecular weight photoreceptor cell protein capable of inducing an experimental autoimmune uveitis (EAU) in susceptible animal strains. The occurrence of serum antibodies against human (Hu) or bovine (Bo) IRBP was investigated in patients with uveitis and healthy controls. A sensitive ELISA detected anti-IRBP in approximately 50 % of patients and controls, without apparent differences in the mean level, titre or avidity and irrespective of the origin of the antigen. Although the correlation (p<0.001) between anti-HulRBP and anti-BolRBP levels in uveitis sera suggested the presence of crossreacting antibodies, these sera also contained antibodies specific for either the human or the bovine antigen. The only difference between patients and controls was the greater ability of antibodies in uveitis sera (p<0.05) to recognize a synthetic peptide of HulRBP, which induces severe EAU in rats. We conclude that autoantibodies to IRBP occur naturally in man and are not increased in patients with uveitis.

ISSN:0271-3683    

DOI:10.3109/02713689009003474

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

DNA damage caused by UV-B and UV-A irradiation and the rate of repair of such damage was quantitated in bovine lens epithelial cell cultures using a modified alkaline elution methodology. Two enzymes, bacteriophage T4 endonuclease V, which cleaves at the the site of pyrimidine dimers, and E. coli endonuclease III, which cleaves at the site of thymine glycols, wen utilized. Pyrimidine dimers were not detected after UV-A irradiation of lens cultures with up ti 400 J/m. In contrast, after exposure to as little as 2 J/mof UV-B irradiation, large numbers of pyrimidine dimers were observed. At higher fluences, thymine glycols were also found. Significant levels of DNA-DNA crosslinking were suggested by reduced rates of elution of DNA from cells treated with both UV-B irradiation and HOin comparison to treatment with HOalone. Protein-DNA crosslinks, in contrast, were not observed. The rate of repair of UV-B induced DNA damage was quantitated by harvesting cells at various times after the UV-B exposure. Single-strand breaks were never observed immediately after UV-B exposure but appeared late during the repair phase. In contrast to the repair of HOinduced DNA damage, which is largely completed within 30 min of exposure, more than 50% of the UV-B light induced DNA damage remained unrepaired five hours after exposure. This difference between the rate of repair of HO and UV-B induced DNA damage could provide valuable insights into the nature of DNA damaging agents i: the lens environment and may reflect underlying differences in the potential for epithelial cell DNA mutation in response to various DNA damaging insults.

ISSN:0271-3683    

DOI:10.3109/02713689009003475

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

Seven specimens of morphologically normal formalin-fixed and paraffin-embedded human retina were studied using a panel of fourteen biotinylated lectins, all of which react with glycoconjugates containing galactose andN-acetylgalactosamine residues.Agaricus bi-sporus(ABA),Bauhiniapurpurea (B?A),Phaseolus vulgaris(PHA-E), peanut (PNA) andRicinus communis(RCA-1) agglutinins labeled photoreceptor cells prior to enzymatic predigestion. BPA and PNA bound specifically to cones. The plexiform layers reacted with ABA, BPA and PHA-E, while only ABA and PHA-E labeled the nuclear layers. After pretreatment with neuraminidase to remove terminal sialii acid, all five lectins, as well asErythrina cristagalli(ECA),Helixpomatia(HP A) andMadura pomifera(MPA) agglutinins labeled both rods and cones. Furthermore, the plexiform layers additionally reacted withECAPNA and RCA-1, and the nuclear layers with BPA and RCA-1 after neuraminidase pretreatment. Retinal vascular endothelial cells consistently bound ABA, ECA, PHA-E and RCA-1, but they could also bine BPA, HP A,Bandeiraea simplicifolia(BSA-I),Dolichos biflorus(DBA) andEuonymus europaeus(EEA) agglutinins in unpretreated sections, a well as MP A, PNA, soybean (SBA) andSophora japonica(SJA) agglutinins subsequent to predigestion with neuraminidase. The nonpig-mented ciliary epithelium reacted with the same lectins as photorecepfc cells, but it was also labeled by DBA.Sambucus nigraagglutinin (SNA) did not specifically bind to any intraocular structure. These findings favor the theory that, in unpretreated specimens, Gal(Bl-→3)GalNAc (BPA and PNA) is mainly responsible for labeling of cones, while Gal(Bl-→3/4)GlcNAc units, partly substituted with terminal sialic acid (PHA-E and RCA-1), explain labeling of rods. Following pretreatment with neuraminidase, further Gal(Bl-→3)GalNAc (BPA and PNA) and, especially, Gal(Bl-→3/4)GlcNAc (BPA, ECA, PHA-E, PNA and RCA-1) and aGalNAc units (BPA, HP A and MP A), the latter partly linked to the protein backbone, contribute to labeling of photoreceptoi cells. Gal(Bl-→3/4)GlcNAc units may be mainly responsible for labeling of nuclear and plexiform layers. Finally, other related receptor sites (SBA and SJA), some of which are blood-group specific (BSA-I, DBA, EEA and HP A) are restricted to retinal vascular endothelia.

ISSN:0271-3683    

DOI:10.3109/02713689009003476

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

The content of rhodopsin in the eyes of 15 donors (30 eyes) was determined. Both retinal and pigment epithelial fractions were collected from each globe, extracted using 1% CTAB, and the rhodopsin difference spectrum of each fraction was obtained separately. The total amount of rhodopsin, obtained by summing the amounts recovered from the retinal and PE fractions, ranged from 2.00 to 11.94 (median: 6.40) nmoles/eye. Previously reported mean values of about 3.5 to 4.0 nmoles per retina have been obtained using a variety of methods. The present higher values, perhaps largely dependent on procedural details described herein, appear plausible given the known concentrations of rhodopsin in rod outer segments, rod outer segment volumes, and number of rods in the human retina.

ISSN:0271-3683    

DOI:10.3109/02713689009003477

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor