Investigative ophthalmology & visual science
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Invest. Ophthalmol. Vis. Sci. · Mar 2000
Neurotrophic factors cause activation of intracellular signaling pathways in Müller cells and other cells of the inner retina, but not photoreceptors.
Intravitreal injection of brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), or basic fibroblast growth factor (FGF2) promotes survival of photoreceptors exposed to various types of insults, but it is not known if these survival-promoting effects occur by direct action of the factors on photoreceptors or indirectly through the activation of other cells. In this study, the authors have sought to address this issue by determining which cells in the retina show evidence of activated intracellular signaling pathways acutely and at longer time points after intravitreal injection of these agents. ⋯ These data support the hypothesis that BDNF, CNTF, and FGF2 exert their effects on photoreceptors by acting indirectly through activation of Müller cells and perhaps other nonphotoreceptor cells.
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Invest. Ophthalmol. Vis. Sci. · Jan 2000
Expression of CD40 and CD40 ligand in the human conjunctival epithelium.
CD40 antigen is a membrane receptor that plays a role in the regulation of immune reactions. The expressions of CD40 and CD40 ligand (CD40L) were investigated ex vivo and in vitro in conjunctival epithelial cells, in correlation with HLA DR class H antigen, previously shown to be upregulated in conjunctival inflammatory conditions. ⋯ Human conjunctival epithelial cells normally express CD40 antigen, and, more inconsistently, CD40L. Flow cytometry showed higher expression of these molecules in inflammatory eyes than in normal ones in correlation with class II antigen expression, as well as CD40 and HLA DR upregulation after treatment with proinflammatory cytokines in vitro.
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Invest. Ophthalmol. Vis. Sci. · Dec 1999
Comparative StudyOptic nerve and peripapillary choroidal microvasculature of the rat eye.
To investigate the three-dimensional microvascular anatomy of the optic nerve and peripapillary choroid in the rat eye. ⋯ The findings illustrate vascular anatomic differences in optic nerve and peripapillary choroidal microcirculation between rat and human. In rats, the peripapillary choroid plays a significant role in both blood supply and venous drainage of the optic nerve head. The central retinal artery also contributes to the optic nerve head circulation.
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Invest. Ophthalmol. Vis. Sci. · Oct 1999
Role of CD4+ T cells in immunobiology of orthotopic corneal transplants in mice.
To determine, with the use of mice genetically deficient in expression of CD4 or CD8 molecules, which T cells are responsible for rejection of orthotopic corneal allografts in mice. ⋯ CD8+ T cells play little or no role in acute rejection of orthotopic corneal allografts. Instead, acute rejection is mediated almost exclusively by CD4+ T cells. Moreover, when corneal allografts survive for 8 weeks without acute rejection, CD4+ T cells promote donor-specific ACAID thereby insuring long-term graft acceptance.
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To describe the arterial blood supply, capillary bed, and venous drainage of the rat optic nerve head. ⋯ The microvasculature of the rat optic nerve head bears several similarities to that of the primate, with a centripetal blood supply from posterior ciliary arteries and drainage into the central retinal and optic nerve sheath veins. Association of nerve sheath veins with the choroid represents an important difference from the primate.