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Query: UMLS:C0022568 (keratitis)
 5,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Quantitative techniques were used to determine the relative concentrations of viable bacteria and polymorphonuclear leukocytes (PMNs) in the corneas of neutropenic and non-neutropenic guinea pigs with experimental bacterial keratitis induced with three strains of Pseudomonas aeruginosa. Neutropenia was produced by whole-body X-irradiation 1 week before infection. Significantly greater numbers of bacteria were present in the cornea of neutropenic animals 48 h after infection than were present in the corneas of non-neutropenic animals. The same was true 24 and 48 h after infecting animals with Staphylococcus aureus. Examination of histological sections showed that fewer PMNs were present in the corneas of infected neutropenic animals than in the corneas of infected non-neutropenic animals. Radiolabeling of PMNs confirmed a significant reduction in PMN concentration in the corneas of infected neutropenic animals. Tears and the corneal epithelium appear to be the most important elements protecting the cornea against local invasion by bacteria. However, once bacterial keratitis is established, PMNs play a role in limiting bacterial multiplication.
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PMID:Experimental bacterial keratitis in neutropenic guinea pigs: polymorphonuclear leukocytes in corneal host defense. 11 62

The inflammatory response to herpes simplex virus infection of the cornea was studied in athymic nude (nu/nu) and heterozygote (nu/+) BALB/c mice. Although athymic mice were highly susceptible to HSV infection and died 13 to 17 days after corneal inoculation, they failed to develop necrotizing keratitis of the cornea. Heterozygote mice survived the initial virual infection, but many of these mice developed necrotizing keratitis and permanent corneal scarring. Light and electron microscopy showed numerous inflammatory cells (polymorphonuclear leukocytes and lymphocytes) in the corneas of heterozygote mice, but not in the athymic mice. These studies suggest that the immune system plays a dual role in herpes simplex virus infection of the cornea: protection against dissemination of the virus and immunopathogenesis of necrotizing keratitis in the cornea.
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PMID:Herpetic keratitis in athymic (nude) mice. 16 Aug 87

An infant, the first-born of twins, delivered by cesarean seciton without prior rupture of the membranes, was noted to have an advanced epithellal and stromal keratitis at berth. Herpes simplex, type 1, was cultured form the cornea and from skin vesicles which developed subsequently. The advanced nature of the lesion indicates that it was acquired in utero. This appears to be the first reported case of congential herpetic keratitis.
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PMID:Congenital herpetic keratitis. 16 75

We used the photodynamic inactivation technique with proflavine as the photoactive dye to treat herpetic epithelial keratitis in a preliminary study of patients who had idoxuridine toxicity or resistance. A comparative study with idoxuridine in treating dendritic ulcerations of the cornea showed a good therapeutic effect. But the investigation was suspended when adverse reactions, consisting of a generalized epithelial keratitis and an anterior uveitis, possibly of phototoxic origin, developed in a few patients receiving treatment. The ulcers treated by photodynamic inactivation apparently healed by a process of "debridement" followed by subsequent re-epithelialization.
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PMID:Proflavine photodynamic viral inactivation in herpes simplex keratitis. 16 61

Pretreatment of human fibroblast cultures with human leukocyte interferon (HIF, 1,000 IU/ml) resulted in a 24-h delay of virus replication after infection with vaccinia virus and herpes simplex virus type 1 and type 2. Additional HIF treatment 24 h after infection effectively lowered the maximum yield of viral infectivity. Equal results were obtained in simian cells with 3,000 IU of HIF per ml. The spread of two cell-bound herpesviruses, varicella zoster virus and Medical Lake macaque herpesvirus, was inhibited by 2,000 IU of HIF per ml in human fibroblasts and Vero cells, respectively. Varicella zoster virus infectivity was notably reduced by HIF, whereas the latter system showed a low sensitivity. To study the effect of HIF in the infected cornea, keratitis was induced experimentally in both eyes of 12 rhesus monkeys and 12 African green monkeys by inoculation with vaccinia virus and herpes simplex virus, respectively. In each monkey one eye served as a control for the full cycle of disease. In the other eye HIF treatment was initiated prophylactically 15 h before or simultaneously with the challenge virus infection or 6 to 20 h postinfectionally or therapeutically after onset of the disease, and the treatment was continued for 2 to 7 days. Prophylactic and simultaneous administration equally resulted in inhibition of both vaccinia and herpes keratitis. Postinfectional and therapeutic administration of interferon moderated the course of keratitis slightly and shortened the period of virus shedding.
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PMID:Effect of human leukocyte interferon on vaccinia-and herpes virus-infected cell cultures and monkey corneas. 16 24

A gereral, overall pattern of the temporal relationship and interaction between cell and antibody-mediated immune responses following herpes simplex virus infection of the rabbit cornea can be synthesized from our studies. Cell-mediated immunity (CMI) appears early following infection, at a time when mononuclear and lymphocytic cellular proliferation occur at the limbus. Interaction between specifically immune lymphocytes with virus antigens are detected by lymphocyte blastogenesis and migration inhabiting factor. During stromal keratitis, a second phase of CMI involves transient virus-specific cytotoxic lymphocytes, which destroy cells that display viral-induced antigens on their surface. Chemotatic factors generated by viral antigens alone or with antiviral antibody or by virus-sensitized lymphocytes play a role in attracting polymorphonuclear leukocytes to the cornea during stromal keratitis. Soluble mediators of CMI secreated by activated lymphocytes act both specifically and nonspecifically on virus-infected cells, allowing cell destruction and making intracellular virus available for neutralization by antiviral antibody. Cell-mediated immunity in the acute infection, diminishes with the appearance of significant antiviral antibody titers. The late phase of the corneal immune response results from a local antigen-antibody interaction and is characterized by cells predominantly of the plasmacytic type. The presence of complement-dependent cytotoxic antibodies capable of destroying virus-infected cells provide an additional factor in restriction of infection.
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PMID:Immunology of herpesvirus infection: immunity to herpes simplex virus in eye infections. 18 41

We report an experimental model that allows objective quantitation of bacterial keratitis. The model permits direct measurement of the number of viable organisms in the cornea after varying periods of in vivo growth. The size of the inoculum used to produce the corneal infection is critical, and the experimental organism must be standardized for its growth characteristics in the cornea. The end point is an objective one, productive of numerical data that can be subjected to statistical analysis. The findings are highly reproducible and the system is sufficiently sensitive to indicate the ability of a topically administered antibiotic to reduce the number of viable organisms in the cornea of an outbred rabbit population.
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PMID:Quantitation of bacterial infection and antibiotic effect in the cornea. 18 95

The development of experimental disciform edema and necrotizing keratitis in the corneas or rabbits following intrastromal inoculation with the RE strain of herpes simplex virus is described. Following an initial episode of conjunctivitis and epithelial keratitis, a mild, centrally localized, stromal edema developed on the fifth day. Stromal edema, opcification, and neovascularization of the cornea reached maximum severity on the seventh to twenty-second day, and began to fade in most eyes thereafter. On the twenty-ninth day most corneas have attained a resolved state characterized by subepithelial granular opacities. Several eyes were observed which developed central necrotizing keratitis. Marked similarities between the animal model and human herpetic stromal keratitis were apparent. Histological observations show that early necrotizing keratitis in the rabbit is characterized by an infiltration of plasma cells and lymphocytes in the limbus, with polymorphonuclear leukocytes, lymphocytes, and macrophages in the central cornea.
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PMID:Experimental disciform edema and necrotizing keratitis in the rabbit. 18 31

Sheep antihuman IgG-antiferritin hybrid antibodies were used for the ultrastructural localization of herpes simplex virus (HSV) antigens in rabbit corneas from animals with herpetic keratitis. In animals with epithelial keratitis in which active viral replication is occurring (6 days after infection), viral antigen was found within nuclei, on nuclear membranes, and on cell surface membranes of epithelial cells. In animals with early necrotizing keratitis in which active viral replication cannot be demonstrated (14 to 21 days after infection), viral antigen was found in association with the cell surface of stromal keratocytes. Since lymphocytic cells in intimate contact with degenerating keratocytes have previously been identified in the cornea, these observations provide a basis for the view that cell-mediated immunopathogenesis is involved in the etiology of herpetic stromal keratitis.
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PMID:Immunoelectron microscopic localization of herpes simplex virus antigens in rabbit cornea with antihuman IgG-antiferritin hybrid antibodies. 19 43

Antibiotic therapy of experimental Pseudomonas keratitis was evaluated quantitatively by determining numbers of viable bacteria in the cornea of guinea pigs. Topically applied carbenicillin disodium, gentamicin sulfate, and tobramycin sulfate were often significantly more effective than topically applied polymyxin B sulfate. Intramuscular therapy with tobramycin was as effective as topical therapy, and the results exhibited less variability. Topical tobramycin every 30 minutes was significantly more effective than topical therapy every 60 minutes. No combination of antibiotics was significantly better than a single effective drug. The concentration of tobramycin in the aqueous correlated more closely to therapeutic efficacy than did the concentration in the cornea. Although all antibiotics reduced numbers of bacteria in the cornea by more than 99% in the first 24 hours of therapy, none was able to sterilize the cornea in four additional days of continuous therapy. Persistence of organisms despite apparently adequate topical therapy may explain some reported cases of relapse in humans.
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PMID:Antibiotic therapy of experimental Pseudomonas keratitis in guinea pigs. 19 8


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