The nuclease-hypersensitivity element III1 in the c-myc promoter is a good anticancer target since it largely controls transcriptional activation of the important c-myc oncogene. Recently, the guanine-rich strand of this element has been shown to form an equilibrium between G-quadruplex structures built from two different sets of G-stretches; two models of intramolecular fold-back antiparallel-stranded G-quadruplexes, called "basket" and "chair" forms, were proposed. Here, we show by NMR that two sequences containing these two sets of G-stretches form intramolecular propeller-type parallel-stranded G-quadruplexes in K(+)-containing solution. The two structures involve a core of three stacked G-tetrads formed by four parallel G-stretches with all anti guanines and three double-chain-reversal loops bridging three G-tetrad layers. The central loop contains two or six residues, while the two other loops contain only one residue.

Recently, the two-repeat human telomeric d(TAGGGTTAGGGT) sequence has been shown to form interconverting parallel and antiparallel G-quadruplex structures in solution. Here, we examine the structures formed by the two-repeat Tetrahymena telomeric d(TGGGGTTGGGGT) sequence, which differs from the human sequence only by one G-for-A replacement in each repeat. We show by NMR that this sequence forms two novel G-quadruplex structures in Na + -containing solution. Both structures are asymmetric, dimeric G-quadruplexes involving a core of four stacked G-tetrads and two edgewise loops. The adjacent strands of the G-tetrad core are alternately parallel and antiparallel. All G-tetrads adopt syn·syn·anti·anti alignments, which occur with 5′-syn-anti-syn-anti-3′ alternations along G-tracks. In the first structure (head-to-head), two loops are at one end of the G-tetrad core; in the second structure (head-to-tail), two loops are located on opposite ends of the G-tetrad core. In contrast to the human telomere counterpart, the proportions of the two forms here are similar for a wide range of temperatures; their unfolding rates are also similar, with an activation enthalpy of 153 kJ/mol.

Purpose: To report a detachment that apparently separated photoreceptor inner segment myoids from inner segment ellipsoids as a manifestation of toxoplasmosis chorioretinitis in a patient with pachychoroid spectrum disease.Methods: Multimodal imaging including fundus photography, spectral domain and enhanced-depth imaging optical coherence tomography (OCT), indocyanine green angiography, and OCT angiography.Results: A 33-year-old man with a history of toxoplasmosis chorioretinitis reported 1 week of decreased vision to 20/200 in his right eye. Examination of the right eye demonstrated mild vitritis with recurrent chorioretinitis inferior to the fovea and adjacent to a chorioretinal scar. A dome-shaped, foveal photoreceptor layersplitting detachment was noted on OCT. Because degenerating cone photoreceptors are capable of shedding their inner segments, we inferred the location of the detachment at the level of the inner segment myoid and provided a histological example of such from an unrelated donor case. In addition, multimodal imaging revealed dilated choroidal veins (pachyvessels) with attenuation of the inner choroid in both eyes and asymptomatic findings of central serous chorioretinopathy in the left eye. After 1 month of antibiotic and steroid therapy, the chorioretinitis resolved, as did the detachment. Hyperreflective foci on the vitreoretinal interface were appreciated with en face OCT that appeared to aggregate throughout the course of therapy, induce inner retinal striae, and resolve without inducing epiretinal membrane formation.Conclusion: Patients with preexisting pachychoroid spectrum disease may manifest a more significant retinal fluid accumulation in the setting of superimposed chorioretinal inflammation. In this case of macular toxoplasmosis chorioretinitis, inflammation manifested as a retinal detachment at the level of photoreceptor inner segment myoids that we named as a bacillary layer detachment. In this case, inflammatory sequelae of toxoplasmosis reactivation responded well to oral and intravitreal therapy.

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The DISCOVER iOCT study demonstrated both generalized feasibility and usefulness based on the surgeon-reported impact on surgical decision making. This large-scale study confirmed similar findings from other studies on the potential value and impact of iOCT on ophthalmic surgery.

ABSTRACT.Purpose: To evaluate the changes of vascular endothelial growth factor (VEGF) plasma levels after intravitreal injections of aflibercept or ranibizumab in patients with exudative age-related macular degeneration (AMD). Methods: Thirty-eight patients with exudative AMD were included in this randomised, prospective study. Nineteen patients were randomised to treatment with intravitreal aflibercept (2.0 mg) and 19 to intravitreal ranibizumab (0.5 mg). The concentration of VEGF was measured by ELISA just before the injection, after 7 days and 1 month. Twenty-two age-and sex-matched healthy patients without chorioretinal diseases served as control. Results: The median baseline plasma VEGF concentration was 61.0 pg/ml in the control group, 43.0 pg/ml in the aflibercept group and 59.0 pg/ml in the ranibizumab group (p = 0.127). Seven days after intravitreal injection of aflibercept plasma levels were significantly reduced to values below the minimum detectable dose (MDD) in 17 of 19 patients (89.5%) resulting in a median VEGF concentration of <9 pg/ml (p < 0.001). The reduction persisted throughout 1 month with values below the MDD in 5 of 19 patients (26.3%) and a median measurement of 17.0 pg/ml (p < 0.001). In patients treated with ranibizumab no significant effects could be observed with a baseline VEGF of 59.0 pg/ml, 54.0 pg/ ml at 7 days (p = 0.776) and 58.5 pg/ml at 4 weeks of follow-up (p = 0.670). Conclusion: After intravitreal aflibercept injection, the systemic VEGF levels were significantly reduced throughout the observational period of 4 weeks. No significant systemic effects of intravitreal ranibizumab on plasma VEGF were observed.

HuR is a member of the Drosophila Elav protein family that binds mRNA degradation sequences and prevents RNase-mediated degradation. Such HuR-mediated mRNA stabilization, which is stimulated by integrin engagement and is controlled at the level of HuR nuclear export, is critically involved in T-cell cytokine production. However, HuR's role in macrophage soluble factor production, in particular in response to angiogenic stimuli, has not yet been established. We show that the labile transcripts that encode vascular endothelial growth factor and matrix metalloproteinase-9 are stabilized when murine macrophages adhere to the β(2) integrin ligand intercellular adhesion molecule-1. This mRNA stabilization response was absent in bone marrow-derived macrophages obtained from conditional macrophage-specific HuR knockout mice. The microvascular angiogenic response to an inflammatory stimulus (ie, subcutaneous polyvinyl alcohol sponge implantation) was markedly diminished in these macrophage HuR knockout mice despite the equal levels of macrophage localization to those observed in littermate wild-type controls. Furthermore, blood flow recovery and ischemic muscle neovascularization after femoral artery ligation were impaired in the conditional macrophage-specific HuR knockout mice. These results demonstrate that dynamic effects on mRNA, mediated by the RNA-binding and RNA-stabilizing protein HuR, are required for macrophage production of angiogenic factors, which play critical roles in the neovascular responses to a variety of stimuli, including tissue ischemia.

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