Investigative ophthalmology & visual science
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Invest. Ophthalmol. Vis. Sci. · Jun 1996
Hypoxia regulates vascular endothelial growth factor receptor KDR/Flk gene expression through adenosine A2 receptors in retinal capillary endothelial cells.
Vascular endothelial growth factor (VEGF) is an endothelial cell-specific angiogenic factor that serves an important role in numerous ischemic retinopathies. The authors studied the hypoxic gene regulation of two known VEGF receptors (KDR and Flt) and its mechanism in cultured bovine retinal endothelial cells (BREC). ⋯ These data suggest that hypoxia induces an initial decline in KDR mRNA levels and VEGF binding sites as mediated through adenosine binding to the A2R. Exposure to prolonged periods of hypoxia, however, results in an increase in VEGF binding sites by an as yet unidentified mechanism.
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Invest. Ophthalmol. Vis. Sci. · Apr 1996
Light-induced acceleration of photoreceptor degeneration in transgenic mice expressing mutant rhodopsin.
Mutations at various loci on the rhodopsin gene have been shown to cause autosomal dominant retinitis pigmentosa (ADRP). One of the most common is a point mutation (P23H) near the N-terminus of the protein. The authors have studied the effects of light deprivation on the rate of degeneration in pigmented transgenic mice expressing the P23H mutation as well as two additional mutations near the N-terminus of opsin (V20G, P27L). ⋯ These findings suggest that light activation of rhodopsin contributes to the severity of the degenerative disease resulting from the P23H opsin mutation, and they raise the possibility that minimizing exposure to light may help to prolong useful vision of patients with this form of retinitis pigmentosa.
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Invest. Ophthalmol. Vis. Sci. · Mar 1994
Relaxation of retinal pericyte contractile tone through the nitric oxide-cyclic guanosine monophosphate pathway.
Pericytes are contractile cells outside the endothelial lining of capillaries. The study investigated whether nitric oxide, known to cause relaxation of vascular smooth muscle cells, also relaxes pericytes. ⋯ Sodium nitroprusside, which releases nitric oxide, strongly relaxes pericytes through an increase of cGMP. Therefore, the presence of the endothelium-derived relaxing factor nitric oxide in the microcirculation can modulate the tone of pericytes, and it thus has the potential to influence blood flow in capillaries.
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Invest. Ophthalmol. Vis. Sci. · Oct 1993
Nonocular Chlamydia infection and risk of ocular reinfection after mass treatment in a trachoma hyperendemic area.
The presence of nasal discharge on a child's face increases the risk of active trachoma, suggesting that Chlamydia trachomatis in nasal secretions may be a possible source of ocular reinfection. The prevalence of chlamydia in nasal secretions and the risk of reinfection after mass treatment was investigated in a hyperendemic area of Tanzania. ⋯ These data do not support a role for nasal secretions in causing reinfection after treatment. One mass topical treatment alone is unlikely to be effective in trachoma hyperendemic areas as shown by the rapid re-emergence of infection.
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Invest. Ophthalmol. Vis. Sci. · Apr 1993
Whatever happened to abstracts from different sections of the association for research in vision and ophthalmology?
The authors investigated the fate of abstracts from each ARVO section (May 1985 meeting), the overall publication percentage, and the journals in which the abstract-derived articles were published. ⋯ The fact that the majority of abstracts led to full-length articles supports ARVO's goal of a large interdisciplinary appeal with the exchange of ideas among different investigators.