摘要:

A simple, non-invasive technique has been developed for assessment of the stability of the pre-corneal tear film. Changes are observed in the reflection of a grid pattern from the tear film surface. Breaks in the tear film appear as random discontinuities in the grid image. Using this non-invasive technique the stability of the pre-corneal tear film was assessed in nine normal subjects and twelve established dry-eye patients. The non-invasive tear film break-up time (NIBUT) of the dry-eye patients was on average only 25% to 32% of normal values. The non-invasive technique provides an alternative approach to diagnosing non-wetting disorders as well as a means of evaluating the efficacy of artifical tear solutions.

ISSN:0271-3683    

DOI:10.3109/02713688508999960

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

Non-invasive tear film break-up time (NIBUT) was measured in nine normal subjects to investigate the effect of fluorescein instillation of tear film stability. It was found that fluorescein instillation reduced the tear film stability in the treated group, compared with the control group (P<0.05). It is, therefore likely that the tear film stability may be greater than had hitherto been suggested by the fluorescein method.

ISSN:0271-3683    

DOI:10.3109/02713688508999961

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

Monoclonal antibodies to bovine a-crystallin have been produced using hybridoma technology. Five selected hybridoma clones were maintained as ascites tumours in mice and gram quantities of the antibodies were purified from the ascites fluids by affinity chromatography onαm-crystallin covalently bound to Sepharose CL-2B. Preliminary characterization studies suggest that the antibodies are pure and monospecific. The antibodies could be divided into two groups on the basis of their reactivities towards iodinatedα-crystallin, their ability to bind to Protein A-Sepharose, their immunoglobulin subclass, their immunoelectrophoretic patterns and their abilities to react with chicken and opossumα-crystallin.The availability of these monoclonal antibodies will greatly facilitate studies on the surface topography ofα-crystallin.

ISSN:0271-3683    

DOI:10.3109/02713688508999962

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

In uveal vessels of isolated arterially perfused rabbit eyes there is direct evidence for the presence of post-junctionalα1-receptors and indirect evidence forα2-receptors. Since vasoconstriction by epinephrine could not be blocked by anα1-antagonist, only 30% by anα2-antagonist and almost fully by the combination or by phentolamine, we suggest the presence of an intermediateα-type receptor which is neitherα1norα2but has characteristics of either. Allα-types produce vasoconstriction and a fall in IOP. Of theβ-types onlyβ1-receptors can be demonstrated. They mediate vasodilatation and a rise in IOP. Neitherβ2-nornon-selectiveβ-agonists or -antagonists (e.g. timolol) affect IOP or uveal flow.

ISSN:0271-3683    

DOI:10.3109/02713688508999963

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

To enhance efforts directed at unraveling the role and mechanisms of leukocytes in mediating injury to corneal epithelium, an isolated bovine corneal cup was developed and evaluated. Bovine peripheral leukocytes and lysates were added to the corneal epithelial surface of isolated cornea for various periods after which the degree of morphologic changes and cell damage were assessed using light and electron microscopy. Results of these studies indicate that leukocyte/epithelial cell interactions are characterized by five successive stages: (1) leukocyte adhesion to superficial layer of the epithelium, (2) leukocyte penetration beneath the superficial epithelium, (3) epithelial cell injury, (4) leukocyte phagocytosis of killed epithelial cells and (5) ulceration and total destruction of the full thickness of the epithelial layer. The above sequence appears to be both time and dose dependent; that is epithelial cells exposed to leukocytes for short periods (5–60 minutes) or to low dose levels (105–107cells/ml) shows leukocyte adhesion and penetration beneath the superficial layer of the epithelium, (stage 1 and 2), while longer exposures (2–3 hours) orghigher numbers of leukocytes (107–108cells/ml), leads to deeper penetration of epithelium by leukocytes and epithelial injury (Stages 3, 4, and 5). We also observed that direct contact of intact leukocytes with epithelial cells is apparently necessary to induce this type of injury. These findings demonstrate the ability of leukocytes to destroy corneal epithelial cells and the value of this new ocular model for studies of the basic immunology of ocular inflammation.

ISSN:0271-3683    

DOI:10.3109/02713688508999964

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

Proteases identified as exopeptidases including dipeptidyl II and III, phenylalanine, leucine, methionine, lysine and alanine aminopeptidases, and prolyl endopeptidase were found in extracts of human fetal lenses. Previous data from normal adult lenses were included for comparison. Except for prolyl endopeptidase and dipeptidyl peptidase II, all protease activties were lower in fetal lenses.

ISSN:0271-3683    

DOI:10.3109/02713688508999965

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

Hybrldomas were developed that secreted monoclonal antibodies against two proteokeratan sulfates (PKS) from rabbit corneal stroma. A total of 28 antibodies were isolated, all of the IgG type with k light chains. All were found to react with both PKSs. As judged by immunohistochemical staining, none of them reacted with scleral or eonjunctival components, nor with sections of skin, but all reacted with nasal cartilage. When tested by enzyme-linked immunosorbent assays, against components of the proteoglycans, all of the antibodies reacted with keratan sulfate-peptide (isolated from papain digests of PKS or of cartilage proteoglycan), and all but two reacted with oligosaccharide-containing protein cores (prepared by keratanase treatment of PKS). Reactivity with cores was probably due to residual portions of the keratan sulfate chains since the endogenous oligosaccharide-peptides (non-sulfated, non-keratan sulfate oligosaccharides isolated after papain digestion of PKS) were not active. None of the antibodies reacted with protein cores made by removal of carbohydrate by hydrolysis with trifluoromethanesulfonic acid. All except one reacted with fragments of keratan sulfate (made by keratanase digestion). These observations are evidence for structural requirements at three different levels of completeness of the antigen for recognition among the various antibodies. In addition, none of the antibodies reacted immunohistochemically with macular dystrophic corneas, confirming the finding of others that the defect lies in the keratan sulfate portion of the proteoglycans.

ISSN:0271-3683    

DOI:10.3109/02713688508999966

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

The effect of retrobulbar epinephrine administration on ocular and optic nerve blood flow was studied in phakic and aphakic rabbit eyes using a radioactive microsphere (85Sr) technique. One hour before blood flow determination, 10µl of a 0.2% (base) epinephrine bitartrate solution was administered to the right eye of each experimental rabbit by the retrobulbar route. For control rabbits, 10µ1 of saline was injected retrobulbarly. Blood flow measurements were determined for the iris, scraped ciliary processes, choroid, retina, and optic nerve. Neither optic nerve nor ocular blood flow was altered by this dose which is approximately the dose used in retrobulbar injections in humans.

ISSN:0271-3683    

DOI:10.3109/02713688508999967

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

We have investigated the effect of the anterior pituitary hormone, prolactin, on mitosis in the lens epithelium of the galactose-fed rat. Our findings indicate that prolactin had a stimulatory effect on galactose-triggered mitosis within 24 hours after hormone administration. After three full days of galactose-feeding and daily prolactin injections, lens epithelia from prolactin treated rats had fewer mitoses than those from saline-injected controls. At the time when the number of mitoses had fallen to a subnormal level due to galactose-feeding (i.e., after 7 days), lenses of prolactin-treated animals exhibited less of a decrease in mitotic activity. Thus, it seems that prolactin modulates the mitotic response of lens epithelial cells when animals are on a galactose-rich diet. This modulation may be due, among other things, to a general acceleration of the cataractogenic process, mediated by the osmoregulatory action of prolactin.

ISSN:0271-3683    

DOI:10.3109/02713688508999968

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

We have developed an in vitro system in which lipid peroxidation can be produced in a predictable fashion and have studied the effects of peroxidation on regenerability of rhodopsin in rod outer segments (ROS). ROS isolated by sucrose flotation from dark-adapted retinas of Rana pipiens were suspended in various concentrations of FeSO4and 1 or 2 mM ascorbic acid for 10 minutes. An increase in lipid hydroperoxides (measured as conjugated dienes) and a decrease in 22:6ω3 were determined for each Fe+2concentration and used as an index of peroxidation. Following incubation with and without FeSO4ROS were pelleted and rhodopsin was regenerated with 15µ11-cis-retinal. The regenerability of rhodopsin in ROS in which significant lipid peroxidation had taken place was reduced by 40–50% compared to controls. DTPA (diethylenetriamine pentaacetic acid), EDTA. and EGTA protected against lipid peroxidation by Fe+2 and allowed almost complete regeneration of rhodopsin. Incubation with DTPA also prevented the destruction of vitamin E in ROS. Other compounds containing primary amine groups did not protect against peroxidation or loss of regenerability. These experiments indicate that lipid peroxidation is associated with a loss of regenerability of the visual pigment rhodopsin.

ISSN:0271-3683    

DOI:10.3109/02713688508999969

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor