This article was withdrawn on October 15, 2020, at the request of the journal editors, with agreement from the authors, owing to a substantial amount of unattributed or improperly cited text overlap with other sources. In accordance with Annual Reviews' commitment to transparency, the original PDF of the article remains available for download at .

Phase unwrapping is one of the major challenges in multiple branches of science that extract three-dimensional information of objects from wrapped signals. In several applications, it is important to extract the unwrapped information with minimal signal resolution degradation. However, most of the denoising techniques for unwrapping are designed to operate on the entire phase map to remove a limited number of phase residues, and therefore they significantly degrade critical information contained in the image. In this paper, we present a novel, smart, and automatic filtering technique for locally minimizing the number of phase residues in noisy wrapped holograms, based on the phasor average filtering (PAF) of patches around each residue point. Both patch sizes and PAF filters are increased in an iterative algorithm to minimize the number of residues and locally restrict the artifacts caused by filtering to the pixels around the residue pixels. Then, the improved wrapped phase can be unwrapped using a simple phase unwrapping technique. The feasibility of our method is confirmed by filtering, unwrapping, and enhancing the quality of a noisy hologram of neurons; the intensity distribution of the spatial frequencies demonstrates a 40-fold improvement, with respect to previous techniques, in preserving the higher frequencies.

PURPOSE: To describe a case of paraneoplastic pemphigus (PNP) presenting as spontaneous bilateral corneal perforations in a patient with follicular dendritic cell sarcoma. METHODS: Retrospective chart review Results: A 73-year-old Greek woman with a history of follicular dendritic cell sarcoma (FDCS) presented with bilateral corneal perforations and a cicatrizing conjunctivitis. Her diagnosis was consistent with PNP with corneal and conjunctival involvement after a change in her chemotherapy regimen from intravenous cyclophosphamide to gemcitabine. She was treated with a multilayered amniotic membrane in the right eye and cyanoacrylate glue in the left eye. Systemic intravenous cyclophosphamide and oral prednisone were re-started. Both perforations healed but the patient passed away soon after precluding further follow-up. CONCLUSIONS: Ocular manifestations of PNP can rarely present with spontaneous corneal perforations. This is the first case of FDCS-associated PNP with corneal involvement. Such cases should be diagnosed expediently and managed with aggressive systemic immunosuppressive therapy.

Exosomes have recently emerged as a pivotal mediator of many physiological and pathological processes. However, the role of exosomes in proliferative vitreoretinopathy (PVR) has not been reported. In this study, we aimed to investigate the role of exosomes in PVR. Transforming growth factor beta 2 (TGFß-2) was used to induce epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells, as an in vitro model of PVR. Exosomes from normal and EMTed RPE cells were extracted and identified. We incubated extracted exosomes with recipient RPE cells, and co-cultured EMTed RPE cells and recipient RPE cells in the presence of the exosome inhibitor GW4869. Both experiments suggested that there are further EMT-promoting effects of exosomes from EMTed RPE cells. MicroRNA sequencing was also performed to identify the miRNA profiles in exosomes from both groups. We identified 34 differentially expressed exosomal miRNAs (P <. 05). Importantly, miR-543 was found in exosomes from EMTed RPE cells, and miR-543-enriched exosomes significantly induced the EMT of recipient RPE cells. Our study demonstrates that exosomal miRNA is differentially expressed in RPE cells during EMT and that these exosomal miRNAs may play pivotal roles in EMT induction. Our results highlight the importance of exosomes as cellular communicators within the microenvironment of PVR.

Myelination facilitates rapid axonal conduction, enabling efficient communication across different parts of the nervous system. Here we examined mechanisms controlling myelination after injury and during axon regeneration in the central nervous system (CNS). Previously, we discovered multiple molecular pathways and strategies that could promote robust axon regrowth after optic nerve injury. However, regenerated axons remain unmyelinated, and the underlying mechanisms are elusive. In this study, we found that, in injured optic nerves, oligodendrocyte precursor cells (OPCs) undergo transient proliferation but fail to differentiate into mature myelination-competent oligodendrocytes, reminiscent of what is observed in human progressive multiple sclerosis. Mechanistically, we showed that OPC-intrinsic GPR17 signaling and sustained activation of microglia inhibit different stages of OPC differentiation. Importantly, co-manipulation of GPR17 and microglia led to extensive myelination of regenerated axons. The regulatory mechanisms of stage-dependent OPC differentiation uncovered here suggest a translatable strategy for efficient de novo myelination after CNS injury.

Diabetic retinopathy (DR) is an eye condition that develops after chronically poorly-managed diabetes, and is presently the main cause for blindness on a global scale. Current treatments for DR such as laser photocoagulation, topical injection of corticosteroids, intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents and vitreoretinal surgery are only applicable at the late stages of DR and there are possibilities of significant adverse effects. Moreover, the forms of treatment available for DR are highly invasive to the eyes. Safer and more effective pharmacological treatments are required for DR treatment, in particular at an early stage. In this review, we cover recently investigated promising oral pharmacotherapies, the methods of which are safer, easier to use, patient-friendly and pain-free, in clinical studies. We especially focus on peroxisome proliferator-activator receptor alpha (PPARα) agonists in which experimental evidence suggests PPARα activation may be closely related to the attenuation of vascular damages, including lipid-induced toxicity, inflammation, an excess of free radical generation, endothelial dysfunction and angiogenesis. Furthermore, oral administration of selective peroxisome proliferator-activated receptor alpha modulator (SPPARMα) agonists may induce hepatic fibroblast growth factor 21 expression, indirectly resulting in retinal protection in animal studies. Our review will enable more comprehensive approaches for understanding protective roles of PPARα for the prevention of DR development.

Spinal cord injury in mammals is thought to trigger scar formation with little regeneration of axons. Here we show that a crush injury to the spinal cord in neonatal mice leads to scar-free healing that permits the growth of long projecting axons through the lesion. Depletion of microglia in neonatal mice disrupts this healing process and stalls the regrowth of axons, suggesting that microglia are critical for orchestrating the injury response. Using single-cell RNA sequencing and functional analyses, we find that neonatal microglia are transiently activated and have at least two key roles in scar-free healing. First, they transiently secrete fibronectin and its binding proteins to form bridges of extracellular matrix that ligate the severed ends of the spinal cord. Second, neonatal-but not adult-microglia express several extracellular and intracellular peptidase inhibitors, as well as other molecules that are involved in resolving inflammation. We transplanted either neonatal microglia or adult microglia treated with peptidase inhibitors into spinal cord lesions of adult mice, and found that both types of microglia significantly improved healing and axon regrowth. Together, our results reveal the cellular and molecular basis of the nearly complete recovery of neonatal mice after spinal cord injury, and suggest strategies that could be used to facilitate scar-free healing in the adult mammalian nervous system.

Age-related macular degeneration (AMD) is the most common cause of irreversible blindness and visual impairment in individuals over the age of 50 years in western societies. More than 25 million people currently suffer from this illness in the world, with an additional 500 000 every year, approximately. It is a multifactorial ocular disease that affects the maculae due to a late-onset progressive neurodegeneration and dysfunction of photoreceptors and retinal pigment epithelium (RPE). There are many subtypes of AMD but basically two broad forms: the nonneovascular (dry, nonexudative) and neovascular (wet, exudative). Exudative AMD is the less common form (about 15%) but tends to progress more rapidly. At the moment, wet AMD is treated primarily on the basis of anti-vascular endothelial growth factor (VEGF) agents, which have led to massive improvement in the prognosis of the disease since they were first introduced. This article focuses on the latest treatment approaches to neovascular AMD. An extensive literature review was performed in order to illustrate the effectiveness of current and future anti-VEGF agents as well as the landmark clinical studies that have been carried out to establish these drugs as a gold standard in the therapy of wet AMD.

In a serosurvey of asymptomatic people from the general population recruited from a clinical laboratory in May 2020 in Addis Ababa, Ethiopia, three of 99 persons tested positive for SARS-CoV-2 IgG (3.0%, 95% binomial exact confidence interval: 0.6-8.6%). Taking into account pretest probability and the sampling scheme, the range of plausible population prevalence values was approximately 1.0-8.4%. These results suggest that a larger number of people have been infected than the counts detected by surveillance to date; nevertheless, the results suggest the large majority of the general population in Addis Ababa currently is susceptible to COVID-19.