ISSN:0277-3740    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

We used a synthetic defensin (rabbit neutrophil peptide-1; NP-1) as a microbicide in a corneal storage medium, Optisol without antimicrobial compounds. We established growth curves in Optisol forStaphylococcus aureus, Streptococcus pneunwniae, and Pseudomonas aeruginosa. Each organism was evaluated separately at 4°C, 23°C, and 37°C in Optisol with NP-1 at each of four different concentrations including 1, 10, 100, and 200 μg/ml. When the three organisms were evaluated in Optisol containing NP-1, we found that a concentration of 200 μg/ml of NP-1 successfully killed 99.9% (the limits of our assay) of all three organisms at all temperatures tested. We conclude that NP-1 exhibits promise as a nonantibiotic preservative agent in corneal storage media, since it was effective in killing organisms at all temperatures, including 4°C.

ISSN:0277-3740    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Perfluorocarbon liquids are fully fluorinated, synthetic, transparent compounds with a high specific gravity. These compounds are being increasingly used as an intraoperative tool for repair of complicated retinal detachments. A potential complication of their use, however, is liquid entering the anterior chamber in aphakic patients. In the study described herein we evaluated the effects of two of these liquids when placed in the anterior chamber of the rabbit eye. Sixteen rabbit eyes underwent anterior chamber injection of 0.05 ml of either perfluoroctane, perfluoropolyether, or balanced salt solution (control eyes). Animals were monitored clinically by biomicroscopy and external photography for up to 14 days, after which they were sacrificed and the corneas processed for light and for scanning electron microscopy. The animals injected with perfluoropolyether showed more intense stromal inflammation and corneal vascularization (p<0.02) than did those that received perfluoroctane. However, the perfluoroctane group showed more of the “fish-egging” phenomenon (p<0.03). Loss of endothelial cells was similar in the two groups, as determined by light and scanning electron microscopy. These results suggest that the corneal toxicity of these two perfluorocarbon liquids is such that their use as vitreous substitutes should be limited to short-term replacement.

ISSN:0277-3740    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

To investigate the physiological role of Harderian glandderived growth factor (HGDGF), the effects of HGDGF and various other growth factors on the growth of cultured guinea pig cornea stromal cells were examined. HGDGF increased the incorporation of [3H]thymidine to 150% of the control (5% fetal calf serum). The combination of HGDGF with fibroblast growth factors (FGFs) or platelet-derived growth factor enhanced the cell growth over that of either growth factor alone, increasing the incorporation of [3H]thymidine to 180 and 190% of the control, respectively. The combination of HGDGF with transforming growth factor (TGF-(3) decreased the growth to 60% of the control, and epidermal growth factor had no effect on the activity of HGDGF. The growthstimulating activity of HGDGF was inhibited by suramin in a different manner from that of FGFs. These findings suggest that HGDGF binds a specific cell-surface receptor and plays a role in the repair of injured parts of the cornea and in the maintenance of the cornea stromal cells.

ISSN:0277-3740    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The major soluble protein in the bovine cornea (BCP 54) has recently been identified as a class 3 aldehyde dehydrogenase. An enzymatic and even a possible structural role of this protein in the mammalian cornea has been proposed. Earlier we showed that the human cornea contains the same enzyme but with a different substrate specificity, compared to the bovine. Moreover, the enzymatic activity was harbored in the dimeric 88-kD species. Genetic variants have been found for several mammalian ocular aldehyde dehydrogenases. In this study we investigated whether such variants were also present in the human cornea by using a zymography technique for aldehyde dehydrogenase activity and immunoblotting with rabbit anti-BCP 54 and lectin staining after isoelectric focusing (IEF) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. We investigated 50 individual human corneal epithelial extracts and found one common IEF variant (n=47) and two “rare” IEF variants in three individuals. Analysis of these patterns indicates that the observed IEF profiles may be caused by posttranslational events.The major soluble protein in the bovine cornea (BCP 54) has recently been identified as a class 3 aldehyde dehydrogenase. An enzymatic and even a possible structural role of this protein in the mammalian cornea has been proposed. Earlier we showed that the human cornea contains the same enzyme but with a different substrate specificity, compared to the bovine. Moreover, the enzymatic activity was harbored in the dimeric 88-kD species. Genetic variants have been found for several mammalian ocular aldehyde dehydrogenases. In this study we investigated whether such variants were also present in the human cornea by using a zymography technique for aldehyde dehydrogenase activity and immunoblotting with rabbit anti-BCP 54 and lectin staining after isoelectric focusing (IEF) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. We investigated 50 individual human corneal epithelial extracts and found one common IEF variant (n=47) and two “rare” IEF variants in three individuals. Analysis of these patterns indicates that the observed IEF profiles may be caused by posttranslational events.

ISSN:0277-3740    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Treatment of bacterial keratitis requires frequent application of topical antibiotics. We studied the efficacy of a single topical administration of tobramycin incorporated in large multivesicular liposomes and enmeshed in a fibrin sealant on rabbit corneas infected withPseudomonas aeruginosa. One cornea each of 25 New Zealand albino rabbits was infected withP. aeruginosa. Twenty-four hours later, the animals were randomly divided into five groups of five. Group A received single hourly drops (50 μl) of fortified tobramycin (14.5 mg/ml, total of 17.4 mg). Group B received a single topical application of 3.5 mg tobramycin, in 0.1 ml multivesicular liposomes, enmeshed in a fibrin sealant with an overlaying bandage contact lens. Group C was treated in the same manner as group B without the addition of fibrin sealant. Groups D and E served as nondrug-treated controls, with group D receiving topical fibrin-enmeshed liposomes devoid of tobramycin and group E receiving hourly topical balanced salt solution (BSS) drops. All animals were killed 24 h after initiation of therapy. Significantly fewer colonies ofPseudomonaswere present in corneas of all three treated groups, as compared with the two nondrug-treated control groups (p < 0.02). There were significantly fewer colonies ofPseudomonasin groups A and B as compared with group C (p < 0.02). No significant difference was noted between a single administration of topical fibrinenmeshed tobramycin-encapsulated liposomes (group B) and 24 doses of hourly fortified topical tobramycin (group A, p > 0.05). Tobramycin-encapsulated megaliposomes may serve as a useful adjunct in treatment ofPseudomonaskeratitis.

ISSN:0277-3740    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Corneal scarring as a consequence of bacterial keratitis is an important cause of visual loss and a major indication for penetrating keratoplasty. Anti-inflammatory agents might be useful in this condition for limiting corneal damage, but benefit from adjunctive anti-inflammatory therapy has never been demonstrated. In this limited pilot study, we compared the effect on clinical outcome of treatingPseudomonaskeratitis in guinea pigs with prednisolone (a corticosteriod), flurbiprofen (a cyclo-oxygenase inhibitor), nordihydroguaiaretic acid (a lipoxygenase inhibitor), and a leukotriene antagonist, SKF104353 [R-(R*, S*)]-β-[(2-carboxyethyl) thio-α-hydroxy-2-(8-phenyloctyl) benzenepropanoic acid, zinc salt]. None of the anti-inflammatory agents prevented sterilization of ulcers with antibiotic (ofloxacin) therapy. Therapy with the leukotriene antagonist appeared to reduce infiltrate size more quickly and produce a more rapid reduction in lesion size, but the differences were not statistically significant. Sample size calculations suggest that very large numbers of animals would be required to prove efficacy. The role of anti-inflammatory agents in reducing the stromal destruction caused by bacterial keratitis remains controversial.

ISSN:0277-3740    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Recurrence ofPseudomonaskeratitis during treatment with corticosteroids has been reported previously in humans. Rabbits with keratitis due toPseudomonas aeruginosa or Streptococcus pneumoniaewere treated with antibiotics and either vehicle, methylprednisolone acetate, flurbiprofen, or nordihydroguaiaretic acid (NDGA). Cultures performed after 7 days were negative, and antibiotics were discontinued. Two weeks later,Pseudomonaskeratitis recurred in 6 of 7 (85.7%) steroid-treated rabbits, 1 of 8 (12.5%) flurbiprofen-treated rabbits, 1 of 8 (12.5%) NDGA-treated rabbits, and none of 8 vehicletreated rabbits. None of the 31 rabbits infected withStreptococcus pneumoniaeexperienced recurrence. These data confirm the clinical observation thatPseudomonaskeratitis may recur if antibiotic therapy is discontinued and corticosteroids are administered; the risk of recurrence appears to be much less with nonsteroidal antiinflammatory agents.

ISSN:0277-3740    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Monocytes transform into tissue macrophages that scavenge necrotic debris from wounds but also release substances stimulatory to fibroblasts. In an effort to encourage the healing process, monocytes, purified from rabbit blood, were injected subconjunctivally 1 or 2 days and 6 or 7 days after alkali injury to the rabbit eye. The injected monocytes failed to alter the course of the alkali-injured eyes. Specifically, the incidence of corneal ulceration in the experimental group was not statistically different from that of the control group. A byproduct of this study was a presentation of the technique to purify platelet-free mononuclear leukocytes from rabbit peripheral blood.

ISSN:0277-3740    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

We examined the effects of the immunotoxin 454A12-rRa on proliferating and confluent human corneal epithelium (HCE) in vitro. Proliferating HCE was sensitive to 454A12-rRA in a dose-dependent fashion. At immunotoxin concentrations of 1,000 ng/ml for 7 days we observed an 86% reduction in cell counts. Confluent HCE was not sensitive to 454A12-rRA at equivalent concentrations of immunotoxin. These data confirm previous observations regarding selective sensitivity of proliferating ocular tissue to immunotoxin, but suggest that HCE is less sensitive to 454A12-rRA than other ocular cell types.

ISSN:0277-3740    

出版商:OVID    

年代:1992

数据来源: OVID