Purpose: We have previously reported that VEGF-B is more potent than VEGF-A in mediating corneal nerve growth in vitro and in vivo, and this stimulation of nerve growth appears to be different from stimulation of angiogenesis by these same ligands, at least in part due to differences in VEGF receptor activation. VEGF signaling may be modulated by a number of factors including receptor number or the formation of receptor hetero- vs. homodimers.
View Article and Find Full Text PDFThe cornea is a highly specialized organ that relies on its mechanical stiffness to maintain its aspheric geometry and refractive power, and corneal diseases such as keratoconus have been linked to abnormal tissue stiffness and biomechanics. Dynamic optical coherence elastography (OCE) is a clinically promising non-contact and non-destructive imaging technique that can provide measurements of corneal tissue stiffness directly in vivo. The method relies on the concepts of elastography where shear waves are generated and imaged within a tissue to obtain mechanical properties such as tissue stiffness.
View Article and Find Full Text PDFCorneal wound healing depends on extracellular matrix (ECM) and topographical cues that modulate migration and proliferation of regenerating cells. In our study, silk films with either flat or nanotopography patterned parallel ridge widths of 2000, 1000, 800 nm surfaces were combined with ECMs which include collagen type I (collagen I), fibronectin, laminin, and Poly-D-Lysine to accelerate corneal wound healing. Silk films with 800 nm ridge width provided better cell spreading and wound recovery than other size topographies.
View Article and Find Full Text PDFPurpose: Corneal opacity is a leading cause of reversible blindness worldwide. An electronic corneal prosthesis, or intraocular projector, could potentially restore high-quality vision without need for corneal clarity.
Materials And Methods: Four intraocular projection systems were constructed from commercially available electronic components and encased in biocompatible plastic housing.
Despite many decades of research and development, corneal opacity remains a leading cause of reversible blindness worldwide. Corneal transplantation and keratoprosthesis can restore corneal clarity, but both have well-known limitations. High-resolution electronic microdisplays may offer an alternative to traditional methods of treating corneal disease using an intraocular implant to project imagery onto the retina, obviating the need for a clear cornea.
View Article and Find Full Text PDFThe purpose of this article is to describe a surgical technique to repair an exposed orbital implant by posterior auricular muscle autograft. A retrospective review was conducted of four patients with an exposed orbital implant that were treated with a posterior auricular muscle graft. Four patients received posterior auricular muscle patch graft to the exposed orbital implant.
View Article and Find Full Text PDFBlepharoptosis or ptosis is a common and potentially debilitating clinical problem. Long-term surgical treatment for ptosis caused by progressive myopathies can be challenging due to potential recurrence and complications associated with facial muscle weakness. When surgical treatment is no longer effective, an eyelid crutch can be used as an alternative intervention.
View Article and Find Full Text PDFUnlabelled: We have investigated genetic/pathogenetic factors associated with a new clinical entity in patients presenting with pheochromocytoma/paraganglioma (PHEO/PGL) and polycythemia. Two patients without hypoxia-inducible factor 2α (HIF2A) mutations, who presented with similar clinical manifestations, were analyzed for other gene mutations, including prolyl hydroxylase (PHD) mutations. We have found for the first time a germ-line mutation in PHD1 in one patient and a novel germ-line PHD2 mutation in a second patient.
View Article and Find Full Text PDFHypoxia-inducible factors (HIFs) control the cellular response to hypoxia and, when dysregulated, contribute to tumorigenesis. Previously, we identified 2 gain-of-function somatic mutations in patients presenting with multiple paragangliomas or somatostatinomas, and polycythemia. Here, we report 2 additional unique HIF2A mutations, which disrupt the hydroxylation domain recognized by prolyl hydroxylase domain-2 containing protein, leading to stabilization of HIF-2α and increased expression of hypoxia-related genes.
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