摘要:

The reactions of lectins with dissociated and cultured epithelial cells from hyperplastic lenses of two unrelated chick strains, Hy-1 and Hy-2, characterised by hyperplasia of the lens epithelium, and lenses of a normal genotype (N) were investigated using four different lectins. Three methods of monitoring lectin-binding to cell surfaces were employed. Each of the four lectins used showed an individual pattern of reactivity to separated membrane components. Data obtained with the three labelling methods showed the same trend viz: increased agglutinability and high affinity for binding of all four lectins by Hy-1 and Hy-2 cells. These results suggest that Hy-1 and Hy-2 lens epithelial cells are characterised by alteration in their cell surfaces.

ISSN:0271-3683    

DOI:10.3109/02713688509000845

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

Proteoglycans, extracellular matrix molecules that have been shown to have filtration properties in some tissues, make up a significant proportion of the structural macromolecules of Bruch's membrane. Bruch's membrane may provide a selective filtration barrier between the choriocapillaris and the pigmented epithelium (PE) and outer retina. In this paper, we compare the proteoglycans extracted from metabolically-labeled normal and retinitis pigmentosa (RP) Bruch's membranes. Isolated RP Bruch's membrane proteoglycans were larger than those from normal donor eyes when chromatographed on a column of Sepharose CL-4B. In addition to the increased size, there was also a dramatic increase in the proportion of heparan sulfate proteoglycan being synthesized in RP. Considering the structural and filtration properties of proteoglycans, alterations such as these could affect the functioning of Bruch's membrane and, possibly, the PE and the outer retina.

ISSN:0271-3683    

DOI:10.3109/02713688509000846

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

The cyclooxygenase and lipoxygenase pathways that produce prostaglandins (PGs) and hydroxyeico-satetraenoic acids (HETEs) were studied in inflamed rabbit cornea. A cryogenic lesion was induced and five days later the epithelium, stroma and endothelium were isolated and incubated with [1-14c]arachidonic acid. After lesioning, the arachidonic acid metabolites, thromboxane B2, PGF2aand 6-keto-PGFlaexhibited the greatest increase in the stroma. Lipoxygenase products were formed in the three layers also, although 12-HETE predominated. The correlation between the synthesis of these compounds and corneal injury is discussed.

ISSN:0271-3683    

DOI:10.3109/02713688509000847

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

Hematoporphyrin (HP), a drug used for the treatment of tumors including intraocular tumors, is an efficient photosensitizer. In addition to its therapeutic value, it also produces a phototoxic side effect in the skin. To test whether such effects may also occur in the eye, calf lens fiber membranes were photolyzed in the presence and absence of 1 mM HP. A marked increase (ca 5 times) in the photopolymerization of the calf lens membrane main intrinsic protein (MP26) was found in the presence of HP. Tenfold increases in destruction rates were found in losses of histidine.The MP26 was also photolyzed after tryptic and chymotryptic digestion to MP21, this resulted in an increased photopolymerization in the presence of 1 mM HP. These data suggest an age related increase in sensitivity of the lens fiber membrane proteins to such photoprocesses. The addition of both azide and penicillamine reduces the photosensitized loss of the main intrinsic protein.

ISSN:0271-3683    

DOI:10.3109/02713688509000848

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

We described an optical method of measuring corneal volume and employed the optical method of Johnson et al. for measuring the volume of the anterior chamber in cynomolgus monkey. In 12 normal monkey eyes, the corneal volume was found to be 40.4±2.3 ul (mean±S.E.) and the anterior chamber volume was 101.8±4.2 ul (mean±S.E.).

ISSN:0271-3683    

DOI:10.3109/02713688509000849

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

S-32-468, a recently synthesized aryloxymethyl beta-adrenoceptor antagonist, was tested for its ability to inhibit activation of isoproterenol-stimulated adenylate cyclase activity in rabbit and human ciliary process, heart and lung. In both species, S-32-468 was a potent inhibitor of ocular beta-adrenoceptors, with a 9-12 fold selectivity over inhibition of beta-adrenoceptors in cardiac tissue. When applied topically, S-32-468 was more effective than timolol in decreasing intraocular pressure in normal albino rabbits.

ISSN:0271-3683    

DOI:10.3109/02713688509000850

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

The transitional process of lens cellular differentiation is accompanied by several unique morphological and biochemical changes. Pyknosis or apoptosis of the nucleus involves extensive degradation of genetic materials. In an attempt to search for a gene product responsible for such a regulatory process, we have adopted DNA-cellulose affinity chromatography to enrich the specific binding protein. A binding protein was isolated by high salt (0.8M KC1) wash of the lens polysomal fraction and purified to apparent homogeneity by DNA-cellulose affinity column and chromatofocusing. The nucleic acid binding protein has an apparent molecular weight of 36,000, designated as regulatory factor 36 (RF-36), as determined by SDS/PAGE. Amino acid composition analysis indicated that RF-36 contains high proportions of glycine, alanine, characteristic of the core heteronucleus RNP proteins. Comparative immunological studies with other DNA binding protein antigen (e.g. helix destabilizing protein) suggest the existence of some common overlapping determinant. However, when monoclonal anti-RF-36 was used as immunoprobe, no cross immunoactivity was detected between these homologous binding proteins, suggesting some antigenic diversity among these two nucleic acid binding proteins from different organisms.

ISSN:0271-3683    

DOI:10.3109/02713688509000851

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

Immunocytochemical studies showed that monoclonal antibodies to bovine retinal S-antigen recognize an immunoreactive protein present in the bovine ciliary body epithelium. This protein was purified by DEAE-agarose chromatography and found to have a M.W. of 28,000 daltons by SDS polyacrylamide gel electrophoresis. Crude and purified preparations of this protein cross-react with polyclonal antibodies to retinal S-antigen. The relative reactivity of S-antigen monoclonal antibodies to ciliary body protein was determined by ELISA. Lewis rats immunized with crude and purified ciliary body protein failed to develop experimental uveitis. The results indicate that the ciliary body protein contains an antigenic peptide domain which is similar to that of S-antigen but lacks the immunopathogenic domain.

ISSN:0271-3683    

DOI:10.3109/02713688509000852

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

The blood-retinal barrier breaks down early in diabetes and previous morphological studies suggest that the retinal pigment epithelium (RPE) is the site of this defect. In the present study the electron microscope lanthanum nitrate tracer technique has been used to study RPE cell permeability in the streptozotocin diabetic rat retina. The freeze-fracture technique has been used to study RPE cell tight junction structure as permeability increases. In the lanthanum experiments, RPE cell permeability is normal in control rats and in diabetic rats 3 weeks after the injections. After 8 or 16 weeks of diabetes, however, the RPE cell layer no longer forms a barrier to the tracer and electron dense material is present in the subretinal space, in the apical and basal regions of the RPE cell junctions and intracellularly within the RPE. Freeze-fracture studies of tight junctions during this period show (1) an increase in the complexity of the tight junction network due to an increase in anastomoses between the tight junctions; (2) a change in membrane fracturing properties such that the tight junctional intra-merabrane particles adhering to the E-face grooves are more numerous than in the control junctions; (3) no change in the number or size of the tight and gap junctional elements. These results suggest that the blood-retinal barrier breakdown in the diabetic RPE is due to alteration of plasma membrane permeability rather than to a loss of tight junctions.

ISSN:0271-3683    

DOI:10.3109/02713688509000853

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

Opsin for immunological studies can be prepared free from S-antigen by affinity chromatography on Con A-Sepharose. This preparation,however,contains 2-6% Con A originating from the affinity medium. Con A as impurity disturbes lymphocyte transformation tests carried out with opsin as test antigen. We describe a method for the removal of Con A by immuno-adsorption to Protein A/anti-Con A/IgG in detergent. In addition, we have selected some detergents and detergent concentrations in which opsin can be purified and added to the lymphocyte culture medi urn.

ISSN:0271-3683    

DOI:10.3109/02713688509000854

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor