Lebreton F, van Schaik W, McGuire AM, Godfrey P, Griggs A, Mazumdar V, Corander J, Cheng L, Saif S, Young S, Zeng Q, Wortman J, Birren B, Willems RJL, Earl AM, Gilmore MS. Emergence of epidemic multidrug-resistant Enterococcus faecium from animal and commensal strains. MBio 2013;4(4)Abstract
UNLABELLED: Enterococcus faecium, natively a gut commensal organism, emerged as a leading cause of multidrug-resistant hospital-acquired infection in the 1980s. As the living record of its adaptation to changes in habitat, we sequenced the genomes of 51 strains, isolated from various ecological environments, to understand how E. faecium emerged as a leading hospital pathogen. Because of the scale and diversity of the sampled strains, we were able to resolve the lineage responsible for epidemic, multidrug-resistant human infection from other strains and to measure the evolutionary distances between groups. We found that the epidemic hospital-adapted lineage is rapidly evolving and emerged approximately 75 years ago, concomitant with the introduction of antibiotics, from a population that included the majority of animal strains, and not from human commensal lines. We further found that the lineage that included most strains of animal origin diverged from the main human commensal line approximately 3,000 years ago, a time that corresponds to increasing urbanization of humans, development of hygienic practices, and domestication of animals, which we speculate contributed to their ecological separation. Each bifurcation was accompanied by the acquisition of new metabolic capabilities and colonization traits on mobile elements and the loss of function and genome remodeling associated with mobile element insertion and movement. As a result, diversity within the species, in terms of sequence divergence as well as gene content, spans a range usually associated with speciation. IMPORTANCE: Enterococci, in particular vancomycin-resistant Enterococcus faecium, recently emerged as a leading cause of hospital-acquired infection worldwide. In this study, we examined genome sequence data to understand the bacterial adaptations that accompanied this transformation from microbes that existed for eons as members of host microbiota. We observed changes in the genomes that paralleled changes in human behavior. An initial bifurcation within the species appears to have occurred at a time that corresponds to the urbanization of humans and domestication of animals, and a more recent bifurcation parallels the introduction of antibiotics in medicine and agriculture. In response to the opportunity to fill niches associated with changes in human activity, a rapidly evolving lineage emerged, a lineage responsible for the vast majority of multidrug-resistant E. faecium infections.
Kim DY, Mukai S. X-linked juvenile retinoschisis (XLRS): a review of genotype-phenotype relationships. Semin Ophthalmol 2013;28(5-6):392-6.Abstract
X-linked juvenile retinoschisis (XLRS) is one of the most common genetic causes of juvenile progressive retinal-vitreal degeneration in males. To date, more than 196 different mutations of the RS1 gene have been associated with XLRS. The mutation spectrum is large and the phenotype variable. This review will focus on the clinical features of XLRS and examine the relationship between phenotype and genotype.
Jakobiec FA, Gragoudas ES, Colby KA. Biopsy of an anterior episcleral nodule as an aid in managing a ciliary body melanocytic tumor. Cornea 2013;32(8):1174-7.Abstract
PURPOSE: To demonstrate the value of a diagnostic biopsy of a fixed episcleral nodule overlying a uveal mass. METHOD: Clinicopathologic report with immunohistochemical investigations. RESULTS: B-scan ultrasonographic biomicroscopy disclosed in a 67-year-old man an asymptomatic placoid ciliary body tumor measuring 1.28 mm in thickness underlying a poorly pigmented, fixed episcleral nodule 0.56 mm in thickness. Biopsy of the episcleral nodule displayed benign nevus-type spindle cells with small nuclei, punctate nucleoli, no mitoses, and scattered melanophages. Immunohistochemistry demonstrated that the tumor cells were Ki67 negative (proliferation index, 0) and MART-1, HMB-45, and microphthalmia-associated transcription factor positive, all melanocytic markers. The melanophages but not the tumor cells were CD68 positive, a histiocytic marker. CONCLUSIONS: The results from biopsying an episcleral nodule can help to select among therapeutic options in managing an associated ciliary body tumor. A 1-year follow-up study and 3 sequential ultrasonographic studies in the current patient have failed to document the growth of the intraocular tumor, further confirming that it is a nevus. The excised epibulbar tumor has not recurred.
McGilligan VE, Gregory-Ksander MS, Li D, Moore JE, Hodges RR, Gilmore MS, Moore TCB, Dartt DA. Staphylococcus aureus activates the NLRP3 inflammasome in human and rat conjunctival goblet cells. PLoS One 2013;8(9):e74010.Abstract
The conjunctiva is a moist mucosal membrane that is constantly exposed to an array of potential pathogens and triggers of inflammation. The NACHT, leucine rich repeat (LRR), and pyrin domain-containing protein 3 (NLRP3) is a Nod-like receptor that can sense pathogens or other triggers, and is highly expressed in wet mucosal membranes. NLRP3 is a member of the multi-protein complex termed the NLRP3 inflammasome that activates the caspase 1 pathway, inducing the secretion of biologically active IL-1β, a major initiator and promoter of inflammation. The purpose of this study was to: (1) determine whether NLRP3 is expressed in the conjunctiva and (2) determine whether goblet cells specifically contribute to innate mediated inflammation via secretion of IL-1β. We report that the receptors known to be involved in the priming and activation of the NLRP3 inflammasome, the purinergic receptors P2X4 and P2X7 and the bacterial Toll-like receptor 2 are present and functional in conjunctival goblet cells. Toxin-containing Staphylococcus aureus (S. aureus), which activates the NLRP3 inflammasome, increased the expression of the inflammasome proteins NLRP3, ASC and pro- and mature caspase 1 in conjunctival goblet cells. The biologically active form of IL-1β was detected in goblet cell culture supernatants in response to S. aureus, which was reduced when the cells were treated with the caspase 1 inhibitor Z-YVAD. We conclude that the NLRP3 inflammasome components are present in conjunctival goblet cells. The NRLP3 inflammasome appears to be activated in conjunctival goblet cells by toxin-containing S. aureus via the caspase 1 pathway to secrete mature IL1-β. Thus goblet cells contribute to the innate immune response in the conjunctiva by activation of the NLRP3 inflammasome.
Hwang AD, Peli E. Development of a Headlight Glare Simulator for a Driving Simulator. Transp Res Part C Emerg Technol 2013;32:129-143.Abstract
We describe the design and construction of a headlight glare simulator to be used with a driving simulator. The system combines a modified programmable off-the-shelf LED display board and a beamsplitter so that the LED lights, representing the headlights of oncoming cars, are superimposed over the driving simulator headlights image. Ideal spatial arrangement of optical components to avoid misalignments of the superimposed images is hard to achieve in practice and variations inevitably introduce some parallax. Furthermore, the driver's viewing position varies with driver's height and seating position preferences exacerbate such misalignment. We reduce the parallax errors using an intuitive calibration procedure (simple drag-and-drop alignment of nine LED positions with calibration dots on the screen). To simulate the dynamics of headlight brightness changes when two vehicles are approaching, LED intensity control algorithms based on both headlight and LED beam shapes were developed. The simulation errors were estimated and compared to real-world headlight brightness variability.
Mansouri B, Stacy RC, Kruger J, Cestari DM. Deprivation amblyopia and congenital hereditary cataract. Semin Ophthalmol 2013;28(5-6):321-6.Abstract
Amblyopia is a neurodevelopmental disorder of vision associated with decreased visual acuity, poor or absent stereopsis, and suppression of information from one eye.(1,2) Amblyopia may be caused by strabismus (strabismic amblyopia), refractive error (anisometropic amblyopia), or deprivation from obstructed vision (deprivation amblyopia). 1 In the developed world, amblyopia is the most common cause of childhood visual impairment, 3 which reduces quality of life 4 and also almost doubles the lifetime risk of legal blindness.(5, 6) Successful treatment of amblyopia greatly depends on early detection and treatment of predisposing disorders such as congenital cataract, which is the most common cause of deprivational amblyopia. Understanding the genetic causes of congenital cataract leads to more effective screening tests, early detection and treatment of infants and children who are at high risk for hereditary congenital cataract.
Hagstrom SA, Ying G-S, Pauer GJT, Sturgill-Short GM, Huang J, Callanan DG, Kim IK, Klein ML, Maguire MG, Martin DF, of Group CAMDTTR. Pharmacogenetics for genes associated with age-related macular degeneration in the Comparison of AMD Treatments Trials (CATT). Ophthalmology 2013;120(3):593-599.Abstract
PURPOSE: To evaluate the pharmacogenetic relationship between genotypes of single nucleotide polymorphisms (SNPs) known to be associated with age-related macular degeneration (AMD) and response to treatment with ranibizumab (Lucentis; Genentech, South San Francisco, CA) or bevacizumab (Avastin; Genentech) for neovascular AMD. DESIGN: Clinical trial. PARTICIPANTS: Eight hundred thirty-four (73%) of 1149 patients participating in the Comparison of AMD Treatments Trials (CATT) were recruited through 43 CATT clinical centers. METHODS: Each patient was genotyped for SNPs rs1061170 (CFH), rs10490924 (ARMS2), rs11200638 (HTRA1), and rs2230199 (C3), using TaqMan SNP genotyping assays (Applied Biosystems, Foster City, CA). MAIN OUTCOMES MEASURES: Genotypic frequencies were compared with clinical measures of response to therapy at one year, including mean visual acuity (VA), mean change in VA, 15-letter or more increase in VA, retinal thickness, mean change in total foveal thickness, presence of fluid on OCT, presence of leakage on fluorescein angiography (FA), mean change in lesion size, and mean number of injections administered. Differences in response by genotype were evaluated with tests of linear trend calculated from logistic regression models for categorical outcomes and linear regression models for continuous outcomes. To adjust for multiple comparisons, P≤0.01 was considered statistically significant. RESULTS: No statistically significant differences in response by genotype were identified for any of the clinical measures studied. Specifically, there were no high-risk alleles that predicted final VA or change in VA, the degree of anatomic response (fluid on OCT or FA, retinal thickness, change in total foveal thickness, change in lesion size), or the number of injections. Furthermore, a stepwise analysis failed to show a significant epistatic interaction among the variants analyzed; that is, response did not vary by the number of risk alleles present. The lack of association was similar whether patients were treated with ranibizumab or bevacizumab or whether they received monthly or pro re nata dosing. CONCLUSIONS: Although specific alleles for CFH, ARMS2, HTRA1, and C3 may predict the development of AMD, they did not predict response to anti-vascular endothelial growth factor therapy.
Li D, Jiao J, Shatos MA, Hodges RR, Dartt DA. Effect of VIP on intracellular [Ca2+], extracellular regulated kinase 1/2, and secretion in cultured rat conjunctival goblet cells. Invest Ophthalmol Vis Sci 2013;54(4):2872-84.Abstract
PURPOSE: To determine the intracellular signaling pathways that vasoactive intestinal peptide (VIP) uses to stimulate high molecular weight glycoconjugate secretion from cultured rat conjunctival goblet cells. METHODS: Goblet cells from rat bulbar and forniceal conjunctiva were grown in organ culture. Presence and localization of VIP receptors (VPAC1 and 2) were determined by RT-PCR, immunofluorescence microscopy and Western blot analysis. Intracellular [Ca(2+)] ([Ca(2+)]i) was measured using fura-2. Extracellular signal-regulated kinase (ERK)-1/2 activity was determined by Western blot analysis. High molecular weight glycoconjugate secretion was measured with an enzyme-linked lectin assay on cultured goblet cells that were serum-starved for 2 hours before stimulation with VIP, VPAC1-, or VPAC2-specific agonists. Inhibitors were added 30 minutes prior to VIP. Activation of epidermal growth factor receptor (EGFR) was measured by immunoprecipitation using an antibody against pTyr followed by Western blot analysis with an antibody against EGFR. RESULTS: Both VIP receptors were present in rat conjunctiva and cultured goblet cells. VIP- and VPAC-specific agonists increased [Ca(2+)]i and secretion in a concentration-dependent manner. VIP also increased ERK1/2 activity, VIP-stimulated increase in [Ca(2+)]i. Secretion, but not ERK1/2 activity, was inhibited by the protein kinase A inhibitor, H89. VIP-stimulated secretion was inhibited by siRNA for ERK2 but not by siRNA for EGFR. VIP did not increase the phosphorylation of the EGFR. CONCLUSIONS: In conclusion, in cultured rat conjunctival goblet cells, VPAC1 and 2 receptors are functional. VIP stimulates a cAMP-dependent increase in [Ca(2+)]i and glycoconjugate secretion, but not ERK1/2 activation. VIP does not activate with EGFR.
Lee HS, Schlereth S, Khandelwal P, Saban DR. Ocular allergy modulation to hi-dose antigen sensitization is a Treg-dependent process. PLoS One 2013;8(9):e75769.Abstract
A reproducible method to inhibit allergic immune responses is accomplished with hi-dose Ag sensitization, via intraperitoneal (IP) injection. However, the role of CD4+ CD25+ FoxP3+ T regulatory cells (Treg) in this process is unknown, as is whether such modulation extends to ocular allergy. We therefore determined herein whether hi-dose sensitization modulates ocular allergy, and whether CD4+ CD25+ FoxP3+ Treg are involved. C57BL/6 mice were IP sensitized via low-dose (100 µg) versus hi-dose (1000 µg) ovalbumin (OVA), in aluminum hydroxide (1 mg) and pertussis-toxin (300 ng). Other mice received anti-CD25 Ab (PC61) to ablate Treg during sensitization. In another experiment, Treg from hi-dose sensitized mice were adoptively transferred into low-dose sensitized mice. Once daily OVA challenges were administered. Clinical signs, IgE, T cell cytokines, and eosinophils were assessed. Data revealed that hi-dose, but not low-dose, sensitization led to allergy modulation, indicated by decreased clinical signs, serum IgE levels, Th2 recall responses, and eosinophil recruitment. T cells from hi-dose sensitized mice showed a robust increase in TGF-b production, and Treg from these mice were able to efficiently suppress effector T cell proliferation in vitro. In addition, in vivo Treg ablation in hi-dose sensitized mice revoked allergy modulation. Lastly, Treg from hi-dose sensitized mice were able to adoptively transfer allergy modulation to their low-dose sensitized counterparts. Collectively, these findings indicate that modulation to hi-dose sensitization, which is extended to ocular allergy, occurs in a Treg-dependent manner. In addition, our data suggest that hi-dose sensitization may henceforth facilitate the further examination of CD4+ CD25+ FoxP3+ Treg in allergic disease.
Kurimoto T, Yin Y, Habboub G, Gilbert H-Y, Li Y, Nakao S, Hafezi-Moghadam A, Benowitz LI. Neutrophils express oncomodulin and promote optic nerve regeneration. J Neurosci 2013;33(37):14816-24.Abstract
Although neurons are normally unable to regenerate their axons after injury to the CNS, this situation can be partially reversed by activating the innate immune system. In a widely studied instance of this phenomenon, proinflammatory agents have been shown to cause retinal ganglion cells, the projection neurons of the eye, to regenerate lengthy axons through the injured optic nerve. However, the role of different molecules and cell populations in mediating this phenomenon remains unclear. We show here that neutrophils, the first responders of the innate immune system, play a central role in inflammation-induced regeneration. Numerous neutrophils enter the mouse eye within a few hours of inducing an inflammatory reaction and express high levels of the atypical growth factor oncomodulin (Ocm). Immunodepletion of neutrophils diminished Ocm levels in the eye without altering levels of CNTF, leukemia inhibitory factor, or IL-6, and suppressed the proregenerative effects of inflammation. A peptide antagonist of Ocm suppressed regeneration as effectively as neutrophil depletion. Macrophages enter the eye later in the inflammatory process but appear to be insufficient to stimulate extensive regeneration in the absence of neutrophils. These data provide the first evidence that neutrophils are a major source of Ocm and can promote axon regeneration in the CNS.
Kanoff J, Miller J. Pharmacogenetics of the treatment response of age-related macular degeneration with ranibizumab and bevacizumab. Semin Ophthalmol 2013;28(5-6):355-60.Abstract
INTRODUCTION: Age-related macular degeneration is a major cause of blindness among people aged 50 and older in industrialized countries. Anti-VEGF therapy has been tremendously successful in the treatment of neovascular macular degeneration. Examining the pharmacogenetics of patients' response to the anti-VEGF molecules could allow for a tailored treatment strategy based on patients' underlying genetics rather than the "one-size fits all" approach currently used. METHODS: Review of the English literature for papers examining the pharmacogenetics of treatment response of neovascular macular degeneration to either ranibizumab or bevacizumab. Polymorphisms in CFH, ARMS2, HTRA1 and VEGF A were examined and reviewed. RESULTS: Patients with the high-risk CC genotype in complement factor H (CFH) had a worse response to therapy with ranibizumab and bevacizumab. No clear trends were found with ARMS2, HTRA1 and VEGF A. CONCLUSIONS: The goal of personalized medicine is to craft a treatment program that is ideally suited to an individual patient's disease and genetic make-up rather than simply what works for a large population who share similar disease characteristics. Continued research is needed to achieve this goal for the treatment of age-related macular degeneration.
Jakobiec FA, Mendoza PR, Colby KA. Clinicopathologic and immunohistochemical studies of conjunctival large cell acanthoma, epidermoid dysplasia, and squamous papilloma. Am J Ophthalmol 2013;156(4):830-46.Abstract
PURPOSE: To evaluate clinicopathologically and immunohistochemically a spectrum of conjunctival squamous proliferations. DESIGN: Retrospective clinicopathologic study. METHODS: One large cell acanthoma, 7 epidermoid dysplasias, and 4 squamous papillomas were evaluated with microscopy and biomarkers Ki-67, p53, epithelial membrane antigen (EMA), Ber-EP4, AE1, AE3, and 8 individual cytokeratins. Normal associated conjunctiva served as a baseline for interpretation. RESULTS: The large cell acanthoma recurred 4 times but retained its benign histopathologic features. The cells were 2-3 times larger than the keratinocytes of the normal conjunctiva and did not display atypia. Immunohistochemistry revealed a low Ki-67 proliferation index (PI) in the large cell acanthoma compared with high indices in dysplasias and papillomas. p53 was negative in the nuclei of normal epithelium while positive in all neoplasms, most intensely in the dysplasias. Immunostaining showed similar staining patterns for cytokeratins in large cell acanthoma and normal conjunctiva, except for full-thickness CK14 positivity and CK7 negativity in the lesion. Dysplasias generally lost normal CK7 expression and frequently abnormally expressed CK17. The papillomas displayed a normal cytokeratin pattern but exhibited a higher than normal PI and weak p53 positivity. CONCLUSIONS: Conjunctival large cell acanthoma is a morphologically distinctive clonal entity with clinical and immunohistochemical phenotypic characteristics denoting a dysplasia of minimal severity. Because of recurrences without invasion, it requires treatment. Dysplasias exhibited more deviant biomarker abnormalities including frequent aberrant full-thickness CK17 positivity and CK7 negativity. The absence of major cytokeratin derangements in the squamous papillomas may be of ancillary diagnostic value for lesions displaying borderline cytologic features.
Marra KV, Yonekawa Y, Papakostas TD, Arroyo JG. Indications and techniques of endoscope assisted vitrectomy. J Ophthalmic Vis Res 2013;8(3):282-90.Abstract
The popularization of ophthalmic endoscopy has been promoted by recent technological advancements that increase the number of indications for endoscopy. These advancements have improved the endoscope's capabilities in its two fundamental surgical advantages: (1) bypassing anterior segment opacities, and (2) visualizing anteriorly positioned structures such as the ciliary bodies and sub-iris space. In this article, the current state of the ophthalmic endoscope is reviewed alongside its growing number of applications in glaucoma, vitreoretinal, and ocular trauma surgery. We describe the role of endoscopy in endocyclophotocoagulation for glaucoma, cyclitic membrane peeling in hypotony, retinal detachment surgery, intraocular foreign body removal, severe endophthalmitis, and pediatric traumatic vitreoretinal surgery. This review examines both the pearls and limitations of the ophthalmic application of endoscopy. In doing so, we hope to provide guidelines for using the endoscope and also to highlight applications of endoscopy that merit further study.
Hodges RR, Dartt DA. Tear film mucins: front line defenders of the ocular surface; comparison with airway and gastrointestinal tract mucins. Exp Eye Res 2013;117:62-78.Abstract
The ocular surface including the cornea and conjunctiva and its overlying tear film are the first tissues of the eye to interact with the external environment. The tear film is complex containing multiple layers secreted by different glands and tissues. Each layer contains specific molecules and proteins that not only maintain the health of the cells on the ocular surface by providing nourishment and removal of waste products but also protect these cells from environment. A major protective mechanism that the corneal and conjunctival cells have developed is secretion of the innermost layer of the tear film, the mucous layer. Both the cornea and conjunctiva express membrane spanning mucins, whereas the conjunctiva also produces soluble mucins. The mucins present in the tear film serve to maintain the hydration of the ocular surface and to provide lubrication and anti-adhesive properties between the cells of the ocular surface and conjunctiva during the blink. A third function is to contribute to the epithelial barrier to prevent pathogens from binding to the ocular surface. This review will focus on the different types of mucins produced by the corneal and conjunctival epithelia. Also included in this review will be a presentation of the structure of mucins, regulation of mucin production, role of mucins in ocular surface diseases, and the differences in mucin production by the ocular surface, airways and gastrointestinal tract.