摘要:

Timolol (TIM) and betaxolol (BET) were evaluated for their effects on both intraocular pressure and retinal sensitivity as determined from visual fields in a randomized two-year parallel study in 20 patients with primary open-angle glaucoma. All treatments were twice-daily in both eyes.TIM was more effective than BET as an ocular hypotensive agent throughout the two year period. With regard to retinal sensitivity as measured by automated visual fields, there was a decrease in retinal sensitivity in the first six months in the TIM and BET treatment groups by 0.5–0.6 dB, and 0.2–0.3 dB, respectively. However, at the one and two year visits, retinal sensitivity increased 0.8–0.9 dB in the BET treatment group only.It appears that ocular hypotensive efficacy may not relate to retinal sensitivity within a period of two years or less in patients with mildly to moderately elevated intraocular pressure. Further work may reveal the reliability of this observation, and its clinical relevance.

ISSN:0271-3683    

DOI:10.3109/02713689209069161

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

In this study the effects of cell-permeable 8-bromo-cAMP and 8-bromo-cGMP on intraocular pressure (IOP) and puncture-induced inflammatory response were investigated. Both 8-bromo-cAMP and 8-Bromo-cGMP reduced IOP when given subconjunctivally, but not topically. Subconjunctival administration of 8-bromo-cAMP induced a moderate disruption of the blood-aqueous barrier (BAB); in addition, subconjunctival 8-bromo-cAMP, but not topical 8-bromo-cAMP or subconjunctival 8-bromo-cGMP, reduced the disruption of the BAB and elevation of the aqueous PGE2level after puncture trauma.It is concluded that the effects of 8-bromo-cAMP depend on the mode of administration, since this determines the concentration of 8-bromo-cAMP reached in the aqueous humor. It is suggested that 8-bromo-cAMP can partially suppress a slight inflammatory response by interference with the release of arachidonic acid from the tissues surrounding the aqueous humor.

ISSN:0271-3683    

DOI:10.3109/02713689209069162

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

Previous studies have shown that the corneal epithelium will close a limbus to limbus scrape wound in four to five days, but requires 10 days to become firmly attached to the stroma. In order to determine if the restoration of the corneal epithelial barrier follows a similar sequence, we have used freeze-fracture to study tight junction reformation in a rabbit epithelial wound model. Dutch-belted rabbit corneal epithelium was removed with a limbus to limbus scrape wound and sampled from 0 to 30 days post-wounding. A minimum of 3 animals from each time point were processed for electron microscopy and freeze-fracture. Freeze-fracture showed that the cells at the wound margin had a reduction in the number of intramembrane particles on their apical surface. In areas adjacent to the wound edge, fragments of tight junctions were first observed on two days post-wounding specimens. The junctions became progressively more complex in the area behind the wound edge until wound closure at four days when the junctions were also present in the central region of the cornea. The maturation of the junctions continued and at five days after surgery they resembled control junctions. This sequence suggests that the establishment of morphologically mature tight junctions may be necessary before the corneal epithelium can firmly reattach to the stroma.

ISSN:0271-3683    

DOI:10.3109/02713689209069163

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

Lens myo-inositol (MI) content is regulated by a pump-leak system consisting of an active Na-depen-dent MI transport and its passive permeability through the membrane. We measured the active MI uptake and membrane permeability in lenses of rats maintained on a 50% galactose diet for 1, 3 and 7 days. After only 1 day of galactose feeding, active MI uptake in the lens was reduced dramatically by 74% compared to age-matched control lenses; by day 3, active Ml transport was decreased by 89% and it was undetectable by day 7. The passive membrane permeability was determined by measuring (a) the passive Ml influx and (b) the3H-sorbitol flux. After 1 day of galactose feeding, the membrane permeability increased such that within 3 days it increased to 5–6 fold. Galactose feeding also led to a rapid increase in lens polyol content. After 1 day, lens polyol increased to 53μmol/g wet wt compared to a control value of 0.35μmol/g wet wt and increased further to 65 and 72μmol/g wet wt after 3 and 7 days of galactose feeding respectively. Lens galactose accumulation was low (3μmol/g wet wt) up to 7 days; however, it was rapidly increased after 7 days. Our results indicate that galactose feeding rapidly interfered with MI homeostasis by a severe depression of active MI transport and a rapid increase in membrane permeability. These interferences of MI homeostasis correlate with the appearance of high polyol levels.

ISSN:0271-3683    

DOI:10.3109/02713689209069164

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

Two different measures of response to therapy were evaluated in a model of keratitis caused byAspergillus fumigatusin Dutch-belted rabbits. Combined pre and post-inoculation treatment with oral fluconazole 37.5mg/kg bid or itraconazole 40 mg/kg bid was compared to post-inoculation treatment only and untreated controls using a standardized clinical disease severity score and quantitative isolate recovery techniques. For both drugs, there was no difference in isolate recovery rates among all three groups. However, a significant improvement in clinical disease was noted in the pre and post-inoculation treatment group compared to controls (p<. 01) and to the post-inoculation group (p<. 05) for fluconazole. A similiar trend, though not statistically significant, was apparent with itraconazole treatment. This disparity highlights the difficulties associated with measuring responses to therapy in keratomycosis and emphasizes the need for more sensitive and specific measures.

ISSN:0271-3683    

DOI:10.3109/02713689209069165

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

Passive administration of antibody against herpes simplex virus type 1 (HSV-1) has been shown to protect against stromal keratitis and death from encephalitis. Although the exact mechanism by which passively-transferred antibody protects is not known, one of the features of protection by passively-transferred antibody is interference with the ability of the virus to spread within the nervous system. In the experiments reported herein, studies were performed to determine if 8D2, a monoclonal antibody against a type-common epitope of glycoprotein D, could protect mice from retinal necrosis following uniocular anterior chamber inoculation of HSV-1. Mice were protected from retinal necrosis when the antibody was administered 2 hours before virus inoculation or 24 hours after virus inoculation. When antibody was injected 2 hours before virus inoculation, the liter of virus at day 1 p.i. in the injected eyes of antibody-treated and control mice was the same, but by 3 days p.i., the liter of virus in the anlibody-lrealed mice was significantly lower than that recovered from control mice. The tilers of virus in the brains and in the uninoculated eyes of antibody-treated mice were also significantly lower than in control mice. The results of these studies suggest that passively-transferred antibody protects against retinal necrosis by limiting spread of virus to the CNS or replication of virus within the CNS.

ISSN:0271-3683    

DOI:10.3109/02713689209069166

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

The protective effects of passive immunization with two kinds of anti-glycoprotein D (anti-gD) monoclonal antibodies, having different antiviral activities, were investigated in murine herpetic keratitis. One monoclonal antibody, designated MI, had high virus-neutralizing antibody titers, along with undetectable levels of complement-dependent cytolysis (CDC) and antibody-dependent cellular cytotoxicity (ADCC); the other, designated MI2, exhibited extremely low titers of virus-neutralization with high level of CDC and ADCC. When systemically administered 24 hours prior to virus inoculation to the cornea, both Ml and MI2 almost completely prevented the development of stromal keratitis. The protective efficacy of both was observed to be dose-dependent. Pepsin-treated Ml retained its efficacy in suppressing stromal keratitis, whereas pepsin—treated M12 did not. When the administration of Ml and M12 were delayed, both provided significant (but less complete) protection, up to 24 hours after virus inoculation.These results suggest that both virus neutralization and CDC/ADCC play an important role in preventing virus growth in the corneal stroma during the early stage of corneal infection.

ISSN:0271-3683    

DOI:10.3109/02713689209069167

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

In these experiments we characterize rabbit and bovine corneal endothelia cell cultured on microporous membrane filters (0.6cm2). Cell cultured bovine or rabbit corneal endothelial cells (subcultures 1–3) were seeded onto Millicell-HA filter inserts. Electrical resistance measured across the cultured monolayers increased steadily through 14 days of culture, reaching 34.2±0.8 ohm-cm (mean±SE) for rabbit cells and 33.1±1.1 ohm-cm2for bovine cells. Alizarin red staining of the monolayers showed a polygonal morphology comparable to that observedin situ.Transmission electron microscopy showed well developed apical junctional complexes and flaps. Exposure of the monolayers to calcium-free medium resulted in the disruption of intercellular junctions, rounding-up of the cells and a decrease in electrical resistance (to near 0). Transmonolayer fluxes of inulin and dextran correlated well to the resistance measurements. Results of this study demonstrate that corneal endothelium, both bovine and rabbit, grown on filter inserts is comparable in morphology and ultrastructure to corneal endotheliumin situ.The cells cultured in this system form functional apical junctional complexes that effect a barrier function comparable to that of the endothelium in situ.

ISSN:0271-3683    

DOI:10.3109/02713689209069168

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

The involvement of retinal pigment epithelial (RPE) cells in the recycling of docosahexaenoic acid (DHA), from phagocytized disc membranes back to the retina, was studied in frogs subsequent to injection of [5H]DHA via the dorsal lymph sac. Rod outer segments (ROS) gradually accumulated [3H]DHA as a dense, heavily labeled region that arrived at the distal tips by 28 days post-injection. Autoradiographic analysis at the time of maximal shedding and phagocytosis (1–2 hr after the onset of light) showed diffusely (before 28 days) and heavily (after 28 days) labeled phagosomes in RPE cells. Biochemical analysis of the [3H]DHA-containing lipids of discs that contribute to the labeling of RPE cells after phagocytosis was also performed. Between 27 and 34 days, when 12% of retinal [3H]DHA-lipids present in disc membranes are phagocytized by RPE cells, total retinal labeling remained unchanged. Taken together, these data suggest that the [3H]DHA of the densely labeled region of the ROS was recycled back to the photoreceptor cells only after it had reached the RPE cells following 28 days post-injection. We conclude that, following daily phagocytosis of ROS tips, RPE cells play a central role in the conservation and redelivery of ROS-derived DHA back to photoreceptor cells through the interphotoreceptor matrix.

ISSN:0271-3683    

DOI:10.3109/02713689209069169

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

The effect of flurbiprofen on the corneal penetration of phenylephrine was investigated using isolated albino rabbit corneas mounted in the Ussing diffusion chamber. The corneal penetration of phenylephrine was increased 5–11 times by 4–16 mM flurbiprofen. Such an increase in the corneal penetration of phenylephrine by flurbiprofen appeared to correlate with the increase in the lipophilicity of phenylephrine by flurbiprofen due to ion pair formation. The magnitude of increase at 16 mM flurbiprofen was 2.4 times less than that afforded by 0.5% EDTA and 16.3 times less than that afforded by deepithelizing the cornea. Since flurbiprofen also increased the corneal penetration of benzoic acid and sorbitol with which it cannot form ion pairs, increased lipophilicity of phenylephrine due to ion pair formation with flurbiprofen was unlikely to be the only mechanism that enhanced corneal penetration. An additional mechanism under our experimental conditions of prolonged exposure of the cornea to the phenylephrine-flurbiprofen combination was lowering of the barrier function of the corneal epithelium by concentrations of flurbiprofen greater than that used therapeutically.

ISSN:0271-3683    

DOI:10.3109/02713689209069170

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor