Publications

2014

A key event during mammalian sexual development is regression of the Müllerian ducts (MDs) in the bipotential urogenital ridges (UGRs) of fetal males, which is caused by the expression of Müllerian inhibiting substance (MIS) in the Sertoli cells of the differentiating testes. The paracrine signaling mechanisms involved in MD regression are not completely understood, particularly since the receptor for MIS, MISR2, is expressed in the mesenchyme surrounding the MD, but regression occurs in both the epithelium and mesenchyme. Microarray analysis comparing MIS signaling competent and Misr2 knockout embryonic UGRs was performed to identify secreted factors that might be important for MIS-mediated regression of the MD. A seven-fold increase in the expression of Wif1, an inhibitor of WNT/β-catenin signaling, was observed in the Misr2-expressing UGRs. Whole mount in situ hybridization of Wif1 revealed a spatial and temporal pattern of expression consistent with Misr2 during the window of MD regression in the mesenchyme surrounding the MD epithelium that was absent in both female UGRs and UGRs knocked out for Misr2. Knockdown of Wif1 expression in male UGRs by Wif1-specific siRNAs beginning on embryonic day 13.5 resulted in MD retention in an organ culture assay, and exposure of female UGRs to added recombinant human MIS induced Wif1 expression in the MD mesenchyme. Knockdown of Wif1 led to increased expression of β-catenin and its downstream targets TCF1/LEF1 in the MD mesenchyme and to decreased apoptosis, resulting in partial to complete retention of the MD. These results strongly suggest that WIF1 secretion by the MD mesenchyme plays a role in MD regression in fetal males.
Radcliffe N, Smith S, Syed Z, Park SC, Ehrlich J, De Moraes CG, Liebmann J, Ritch R. Retinal blood vessel positional shifts and glaucoma progression. Ophthalmology. 2014;121(4):842–8.
PURPOSE: To determine the characteristics and significance of retinal blood vessel (RBV) positional shifts over time in a cohort of patients with progressive glaucoma. DESIGN: Retrospective cohort study. PARTICIPANTS: Baseline and serial stereophotographs from 1 eye of 125 patients with open-angle glaucoma with ≥8 reliable Swedish interactive threshold algorithm standard visual fields (VFs) were included. On the basis of global rates of threshold sensitivity change, patients with glaucoma were divided into groups of minimal (<-0.02 decibels [dB]/year), moderate (-0.02 to -0.65 dB/year), or fast (≥-0.65 dB/year) progression. To determine whether graders' assessments of RBV positional shifts were false-positives, a control group consisting of 33 patients with glaucoma with 2 sets of photographs taken on the same day was included. METHODS: Masked graders reviewed serial photographs aligned with automated alternation flicker (EyeIC, Narbeth, PA) and assessed them for the presence of any discrete RBV positional shifts (2 graders) and for traditional measures of structural progression (2 graders), including neuroretinal rim loss, parapapillary atrophy progression, and disc hemorrhage (DH). MAIN OUTCOME MEASURES: Presence or absence of RBV positional shifts, rates of VF progression, and presence or absence of traditional measures of structural progression. RESULTS: A total of 158 image sets (125 longitudinal and 33 same-day controls) from patients with glaucoma were included. Retinal blood vessel shifts were noted in 33 of 125 (26.4%) longitudinally followed glaucomatous eyes and 2 of 33 (6%) same-day control patients (P = 0.01). Agreement between graders I and II was 90.4% (kappa=0.77; P< 0.001). Eyes with RBV positional change progressed more rapidly than those without (-0.55 vs. -0.29 dB/year; 95% confidence interval [CI], 0.03-0.48); P = 0.03). Retinal blood vessel shift was present in 12.1% of minimal progressors versus 31.5% of moderate and fast progressors (P = 0.04). Rate of VF progression was statistically associated with RBV shift (odds ratio [OR], 2.2; 95% CI, 1.1-4.5; P = 0.03). Other variables significantly associated with RBV shift included neuroretinal rim loss (OR, 21.9; 95% CI, 5.7-83.6; P< 0.001) and DH (OR, 4.6; 95% CI, 1.5-15.5; P< 0.01). A multivariable model revealed that rim loss and DH, but not rate of functional change, were significantly associated with RBV shift. CONCLUSIONS: Retinal blood vessel positional shifts occurred in eyes with functionally progressive glaucoma, neuroretinal rim loss, and DH. This is a novel clinical finding that could help identify glaucoma progression or individuals at higher risk for future progression.
Vascular tumors (in contrast to dilations or ectasias) of the conjunctiva and other adnexal tissues are rare, with no previous convincing example of a congenital, purely venous conjunctival malformation having been described. A 33-year-old man with a previously well-tolerated racemose conjunctival lesion present from birth developed bothersome symptoms when it underwent multifocal thrombosis with papillary endothelial cell hyperplasia as part of the process of thrombotic organization. Conservative subtotal excision with placement of an amniotic graft led to an acceptable cosmetic appearance, abatement of symptoms, and retention of full ocular function. Histopathologically, the lesion was composed of patulous vascular channels with thin walls displaying a negligible and irregular muscularis, diffuse supportive mural fibrosis, and the absence of an elastic lamina. Immunohistochemically the endothelial cells were CD31- and CD34-positive (vascular origin) but D2-40-negative (lymphatic origin). An associated neovascular capillary bed was not detected. Venous (racemose or grape-like) malformations should be distinguished from: arteriovenous (cirsoid or twisted) malformations in which the vessels possess thicker and more uniform muscular walls, some of which are endowed with an elastica; varices (hemorrhoidal dilations typically of a pre-existent vein); and venous angiomas (noncongenital lesions acquired in middle life) composed of regularly structured muscular channels devoid of an elastic lamina. Other conditions not to be confused with congenital venous malformations include hemorrhagic lymphangiectasia (of Leber), hemorrhagic lymphangiomas, and complex lymphaticovenous malformations.
Jakobiec F, Stacy R, Mendoza P, Chodosh J. Hyperplastic corneal pannus: an immunohistochemical analysis and review. Surv Ophthalmol. 2014;59(4):448–53.
An exuberant corneal pannus usually develops in adults with a history of surgery or trauma in the anterior central stroma and appears as a glistening, vascularized, moderately elevated, well circumscribed white nodule. We describe a 78-year-old woman with such a pannus, which in the past has typically been referred to as keloidal or hypertrophic. The involved eye had only light perception, and she underwent a penetrating keratoplasty that improved her vision to 20/100. Histopathologic and immunohistochemical evaluations of a the specimen disclosed a reactive spindle cell stromal proliferation of myofibroblasts that were smooth muscle actin positive with a low Ki67 proliferation index. Desmin, caldesmon, and calponin were negative, in keeping with the incomplete myofilamentary differentiation of a myofibroblast. There was a generous admixture of CD68/163-positive histiocytes and dispersed C3/5-positive T-lymphocytes. An absence of CD138- and IgG4-positive plasma cells ruled out an IgG4-related disease. For a lesion to be keloidal, the collagen must have a thick hyaline character, sharp edges, and a sparsity of intervening cells and vessels. A hypertrophic pannus would be composed of large swollen cells not necessarily increased in number. We therefore recommend adoption of the term hyperplastic for lesions like that described here because of the obvious increase in cellularity from proliferating myofibroblasts and the lack of true keloidal collagen.
Kang J, Wiggs J, Pasquale L. Relation between time spent outdoors and exfoliation glaucoma or exfoliation glaucoma suspect. Am J Ophthalmol. 2014;158(3):605–14.e1.
PURPOSE: To evaluate the relation between time spent outdoors at various life periods and risk of exfoliation glaucoma or exfoliation glaucoma suspect. DESIGN: Retrospective cohort study in the United States. METHODS: Participants (49 033 women in the Nurses Health Study and 20 066 men in the Health Professionals Follow-up Study) were 60+ years old, were free of glaucoma and cataract, reported eye examinations, and completed questions about time spent outdoors in direct sunlight at midday at 3 life periods: high school to age 24 years, age 25-35 years, and age 36-59 years (asked in 2006 in women and 2008 in men). Participants were followed biennially with mailed questionnaires from 1980 women/1986 men to 2010. Incident cases (223 women and 38 men) were confirmed with medical records. Cohort-specific multivariable-adjusted rate ratios from Cox proportional hazards models were estimated and pooled with meta-analysis. RESULTS: Although no association was observed with greater time spent outdoors in the ages of 25-35 or ages 36-59 years, the pooled multivariable-adjusted rate ratios for ≥11 hours per week spent outdoors in high school to age 24 years compared with ≤5 hours per week was 2.00 (95% confidence interval = 1.30, 3.08; P for linear trend = .001). In women, this association was stronger in those who resided in the southern geographic tier in young adulthood (P for interaction = .07). CONCLUSIONS: Greater time spent outdoors in young adulthood was associated with risk of exfoliation glaucoma or exfoliation glaucoma suspect, supporting an etiologic role of early exposures to climatic factors.
Kang, Loomis, Yaspan, Bailey, Weinreb, Lee, Lichter, Budenz, Liu Y, Realini, Gaasterland, Gaasterland, Friedman, McCarty, Moroi, Olson, Schuman, Singh, Vollrath, Wollstein, Zack, Brilliant, Sit, Christen, Fingert, Forman, Buys, Kraft, Zhang, Allingham, Pericak-Vance, Richards, Hauser, Haines, Wiggs, Pasquale LR. Vascular tone pathway polymorphisms in relation to primary open-angle glaucoma. Eye (Lond). 2014;28(6):662–71.
AIMS: Vascular perfusion may be impaired in primary open-angle glaucoma (POAG); thus, we evaluated a panel of markers in vascular tone-regulating genes in relation to POAG. METHODS: We used Illumina 660W-Quad array genotype data and pooled P-values from 3108 POAG cases and 3430 controls from the combined National Eye Institute Glaucoma Human Genetics Collaboration consortium and Glaucoma Genes and Environment studies. Using information from previous literature and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, we compiled single-nucleotide polymorphisms (SNPs) in 186 vascular tone-regulating genes. We used the 'Pathway Analysis by Randomization Incorporating Structure' analysis software, which performed 1000 permutations to compare the overall pathway and selected genes with comparable randomly generated pathways and genes in their association with POAG. RESULTS: The vascular tone pathway was not associated with POAG overall or POAG subtypes, defined by the type of visual field loss (early paracentral loss (n=224 cases) or only peripheral loss (n=993 cases)) (permuted P≥0.20). In gene-based analyses, eight were associated with POAG overall at permuted P<0.001: PRKAA1, CAV1, ITPR3, EDNRB, GNB2, DNM2, HFE, and MYL9. Notably, six of these eight (the first six listed) code for factors involved in the endothelial nitric oxide synthase activity, and three of these six (CAV1, ITPR3, and EDNRB) were also associated with early paracentral loss at P<0.001, whereas none of the six genes reached P<0.001 for peripheral loss only. DISCUSSION: Although the assembled vascular tone SNP set was not associated with POAG, genes that code for local factors involved in setting vascular tone were associated with POAG.
Karamichos, Hutcheon, Rich, Trinkaus-Randall, Asara, Zieske. In vitro model suggests oxidative stress involved in keratoconus disease. Sci Rep. 2014;4:4608.
Keratoconus (KC) affects 1:2000 people and is a disorder where cornea thins and assumes a conical shape. Advanced KC requires surgery to maintain vision. The role of oxidative stress in KC remains unclear. We aimed to identify oxidative stress levels between human corneal keratocytes (HCKs), fibroblasts (HCFs) and keratoconus cells (HKCs). Cells were cultured in 2D and 3D systems. Vitamin C (VitC) and TGF-β3 (T3) were used for 4 weeks to stimulate self-assembled extracellular matrix (ECM). No T3 used as controls. Samples were analyzed using qRT-PCR and metabolomics. qRT-PCR data showed low levels of collagen I and V, as well as keratocan for HKCs, indicating differentiation to a myofibroblast phenotype. Collagen type III, a marker for fibrosis, was up regulated in HKCs. We robustly detected more than 150 metabolites of the targeted 250 by LC-MS/MS per condition and among those metabolites several were related to oxidative stress. Lactate levels, lactate/malate and lactate/pyruvate ratios were elevated in HKCs, while arginine and glutathione/oxidized glutathione ratio were reduced. Similar patterns found in both 2D and 3D. Our data shows that fibroblasts exhibit enhanced oxidative stress compared to keratocytes. Furthermore the HKC cells exhibit the greatest level suggesting they may have a myofibroblast phenotype.
Karamichos D, Funderburgh M, Hutcheon A, Zieske J, Du Y, Wu J, Funderburgh J. A role for topographic cues in the organization of collagenous matrix by corneal fibroblasts and stem cells. PLoS One. 2014;9(1):e86260.
Human corneal fibroblasts (HCF) and corneal stromal stem cells (CSSC) each secrete and organize a thick stroma-like extracellular matrix in response to different substrata, but neither cell type organizes matrix on tissue-culture polystyrene. This study compared cell differentiation and extracellular matrix secreted by these two cell types when they were cultured on identical substrata, polycarbonate Transwell filters. After 4 weeks in culture, both cell types upregulated expression of genes marking differentiated keratocytes (KERA, CHST6, AQP1, B3GNT7). Absolute expression levels of these genes and secretion of keratan sulfate proteoglycans were significantly greater in CSSC than HCF. Both cultures produced extensive extracellular matrix of aligned collagen fibrils types I and V, exhibiting cornea-like lamellar structure. Unlike HCF, CSSC produced little matrix in the presence of serum. Construct thickness and collagen organization was enhanced by TGF-ß3. Scanning electron microscopic examination of the polycarbonate membrane revealed shallow parallel grooves with spacing of 200-300 nm, similar to the topography of aligned nanofiber substratum which we previously showed to induce matrix organization by CSSC. These results demonstrate that both corneal fibroblasts and stromal stem cells respond to a specific pattern of topographical cues by secreting highly organized extracellular matrix typical of corneal stroma. The data also suggest that the potential for matrix secretion and organization may not be directly related to the expression of molecular markers used to identify differentiated keratocytes.
Khurelbat D, Dorj G, Bayarsaikhan E, Chimedsuren M, Sanjjav T, Morimoto T, Morley M, Morley K. Prevalence estimates of substandard drugs in Mongolia using a random sample survey. Springerplus. 2014;3:709.
To determine the prevalence of substandard drugs in urban (Ulaanbaatar) and rural (selected provinces) areas of Mongolia, samples of 9 common, therapeutically important drugs were collected from randomly selected drug outlets in Ulaanbaatar and 4 rural provinces by "mystery shoppers". Samples were analyzed by visual inspection, registration status, and biochemical analysis. Samples failing to meet all Pharmacopeia quality tests were considered substandard. In the rural provinces, 69 out of 388 samples were substandard, giving an estimated prevalence of substandard drugs of 17.8% (95% CI: 14.1-22.0). There were 85 unregistered samples, giving a prevalence estimate of unregistered drugs of 21.9%. (95% CI: 17.9-26.3). In the urban Ulaanbaatar districts, 112 out of 848 samples were substandard, giving an estimated prevalence of substandard drugs of 13.2% (95% CI: 11.0-15.7). There were 150 unregistered samples, giving a prevalence estimate of unregistered drugs of 17.7% (95% CI: 15.2-20.4). In the rural provinces, 35 out of 85 (41.2%) unregistered samples were substandard; whereas 34 out of 303 (11.2%) registered samples were substandard. (p < 0.0001) In the urban districts, 18 out of 150 (12.0%) unregistered samples were substandard, whereas 94 out of 698 registered were substandard. (13.5%) (p = 0.6). The prevalence of substandard and unregistered drugs is higher in rural provinces. There is a significant association between substandard and unregistered drugs in the provinces but not in the urban districts. The underlying causes for substandard drugs need to be further investigated in order to help formulate strategies to improve pharmacovigilance and the drug supply quality in Mongolia.
Kruger J, Yonekawa Y, Skidd P, Cestari D. Ocular flutter as the presenting sign of lung adenocarcinoma. Digit J Ophthalmol. 2014;20(1):4–6.
Ocular flutter is a rare ophthalmic finding that could represent paraneoplastic phenomena. In adults it is most commonly associated with small cell lung cancer (SCLC). Most patients also present with other neurological defects. We report the case of a 75-year-old woman who presented with isolated ocular flutter. The ensuing workup was significant for an early lung adenocarcinoma that would not have been biopsied otherwise due to its small size. To our knowledge, this is the first reported case of isolated ocular flutter as the presenting symptom of non-SCLC.