Streptococcus pneumoniae (the pneumococcus) has wall teichoic acid (WTA) and lipoteichoic acid (LTA) expressing the Forssman antigen (FA). Two lectins, Dolichos biflorus agglutinin (DBA) and Helix pomatia agglutinin (HPA), are known to bind FA. To determine the molecular structure targeted by these two lectins, different pneumococcal strains were studied for DBA/HPA binding with flow cytometry and fluorescence microscopy.
View Article and Find Full Text PDFPurpose: In juvenile tree shrews that have developed minus lens-induced myopia, if lens treatment is discontinued, refractive recovery (REC) occurs. However, in age-matched juvenile animals, plus-lens wear (PLW) produces little refractive change, although the visual stimulus (myopia) is similar (an "IGNORE" response). Because the sclera controls axial elongation and refractive error, we examined gene expression in the sclera produced by PLW and compared it with the gene expression signature produced by REC to learn whether these similar refractive conditions produce similar, or differing, scleral responses.
View Article and Find Full Text PDFIntroduction: Pneumococcus is a commensal of the upper respiratory tract and colonization is common in young children. Carriage studies have provided insights on vaccine effects in children and may also be useful for assessing vaccines in adults. However, culture based prevalence studies in older adults describe low colonization rates.
View Article and Find Full Text PDFHyperopic refractive error is detected by retinal neurons, which generate GO signals through a direct emmetropization signaling cascade: retinal pigment epithelium (RPE) into choroid and then into sclera, thereby increasing axial elongation. To examine signaling early in this cascade, we measured gene expression in the retina and RPE after short exposure to hyperopia produced by minus-lens wear. Gene expression in each tissue was compared with gene expression in combined retina + RPE.
View Article and Find Full Text PDFWe examined the effect of intravitreal injections of D1-like and D2-like dopamine receptor agonists and antagonists and D4 receptor drugs on form-deprivation myopia (FDM) in tree shrews, mammals closely related to primates. In eleven groups (n = 7 per group), we measured the amount of FDM produced by monocular form deprivation (FD) over an 11-day treatment period. The untreated fellow eye served as a control.
View Article and Find Full Text PDFlntravitreal injection of substances dissolved in a vehicle solution is a common tool used to assess retinal function. We examined the effect of injection procedures (three groups) and vehicle solutions (four groups) on the development of form deprivation myopia (FDM) in juvenile tree shrews, mammals closely related to primates, starting at 24 days of visual experience (about 45 days of age). In seven groups (n = 7 per group), the myopia produced by monocular form deprivation (FD) was measured daily for 12 days during an 11-day treatment period.
View Article and Find Full Text PDFPurpose: During postnatal refractive development, the sclera receives retinally generated signals that regulate its biochemical properties. Hyperopic refractive error causes the retina to produce "GO" signals that, through the direct emmetropization pathway, cause scleral remodeling that increases the axial elongation rate of the eye, reducing the hyperopia. Myopia causes the retina to generate "STOP" signals that produce scleral remodeling, slowing the axial elongation rate and reducing the myopia.
View Article and Find Full Text PDFWe examined gene expression in tree shrew choroid in response to three different myopiagenic conditions: minus lens (ML) wear, form deprivation (FD), and continuous darkness (DK). Four groups of tree shrews (n=7 per group) were used. Starting 24 days after normal eye opening (days of visual experience [DVE]), the ML group wore a monocular -5D lens for 2 days.
View Article and Find Full Text PDFGene expression in tree shrew choroid was examined during the development of minus-lens induced myopia (LIM, a GO condition), after completion of minus-lens compensation (a STAY condition), and early in recovery (REC) from induced myopia (a STOP condition). Five groups of tree shrews (n = 7 per group) were used. Starting 24 days after normal eye-opening (days of visual experience [DVE]), one minus-lens group wore a monocular -5 D lens for 2 days (LIM-2), another minus-lens group achieved stable lens compensation while wearing a monocular -5 D lens for 11 days (LIM-11); a recovery group also wore a -5 D lens for 11 days and then received 2 days of recovery starting at 35 DVE (REC-2).
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
October 2013
Purpose: We compared gene expression signatures in tree shrew sclera produced by three different visual conditions that all produce ocular elongation and myopia: minus-lens wear, form deprivation, and dark treatment.
Methods: Six groups of tree shrews (n = 7 per group) were used. Starting 24 days after normal eye-opening (days of visual experience [DVE]), two minus-lens groups wore a monocular -5 diopter (D) lens for 2 days (ML-2) or 4 days (ML-4); two form-deprivation groups wore a monocular translucent diffuser for 2 days (FD-2) or 4 days (FD-4).
Invest Ophthalmol Vis Sci
January 2012
Purpose: During the development of, and recovery from, negative lens-induced myopia there is regulated remodeling of the scleral extracellular matrix (ECM) that controls the extensibility of the sclera. Difference gel electrophoresis (DIGE) was used to identify and categorize proteins whose levels are altered in this process.
Methods: Two groups of five tree shrews started monocular lens wear 24 days after eye opening (days of visual experience [VE]).
Purpose: To increase our understanding of the mechanisms that remodel the sclera during the development of lens-induced myopia, when the sclera responds to putative "go" signals of retinal origin, and during recovery from lens-induced myopia, when the sclera responds to retinally-derived "stop" signals.
Methods: Seven groups of tree shrews were used to examine mRNA levels during minus lens compensation and recovery. Starting 24 days after eye opening (days of visual experience [VE]) lens compensation animals wore a monocular -5D lens for 1, 4, or 11 days.
Purpose: The tree shrew model of refractive development is particularly useful because, like humans, tree shrews have a fibrous sclera. Selective changes in some candidate extracellular matrix proteins and mRNAs have been found in the sclera during the development of and recovery from induced myopia. We undertook a more neutral proteomic analysis using two-dimensional gel electrophoresis and mass spectrometry to identify scleral proteins that are differentially expressed during the development of and recovery from lens-induced myopia.
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