July 2014

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Sweigard HJ, Yanai R, Gaissert P, Saint-Geniez M, Kataoka K, Thanos A, Stahl GL, Lambris JD, Connor KM. The alternative complement pathway regulates pathological angiogenesis in the retina. FASEB J 2014;28(7):3171-82.Abstract
A defining feature in proliferative retinopathies is the formation of pathological neovessels. In these diseases, the balance between neovessel formation and regression determines blindness, making the modulation of neovessel growth highly desirable. The role of the immune system in these retinopathies is of increasing interest, but it is not completely understood. We investigated the role of the alternative complement pathway during the formation and resolution of aberrant neovascularization. We used alternative complement pathway-deficient (Fb(-/-)) mice and age- and strain-matched control mice to assess neovessel development and regression in an oxygen-induced retinopathy (OIR) mouse model. In the control mice, we found increased transcription of Fb after OIR treatment. In the Fb(-/-) mice, we prepared retinal flatmounts and identified an increased number of neovessels, peaking at postnatal day 17 (P17; P=0.001). Subjecting human umbilical vein endothelial cells (HUVECs) to low oxygen, mimicking a characteristic of neovessels, decreased the expression of the complement inhibitor Cd55. Finally, using laser capture microdissection (LCM) to isolate the neovessels after OIR, we found decreased expression of Cd55 (P=0.005). Together, our data implicate the alternative complement pathway in facilitating neovessel clearance by down-regulating the complement inhibitor Cd55 specifically on neovessels, allowing for their targeted removal while leaving the established vasculature intact.-Sweigard, J. H., Yanai, R., Gaissert, P., Saint-Geniez, M., Kataoka, K., Thanos, A., Stahl, G. L., Lambris, J. D., Connor, K. M. The alternative complement pathway regulates pathological angiogenesis in the retina.
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Tang H, Buia C, Madhavan R, Crone NE, Madsen JR, Anderson WS, Kreiman G. Spatiotemporal dynamics underlying object completion in human ventral visual cortex. Neuron 2014;83(3):736-48.Abstract
Natural vision often involves recognizing objects from partial information. Recognition of objects from parts presents a significant challenge for theories of vision because it requires spatial integration and extrapolation from prior knowledge. Here we recorded intracranial field potentials of 113 visually selective electrodes from epilepsy patients in response to whole and partial objects. Responses along the ventral visual stream, particularly the inferior occipital and fusiform gyri, remained selective despite showing only 9%-25% of the object areas. However, these visually selective signals emerged ∼100 ms later for partial versus whole objects. These processing delays were particularly pronounced in higher visual areas within the ventral stream. This latency difference persisted when controlling for changes in contrast, signal amplitude, and the strength of selectivity. These results argue against a purely feedforward explanation of recognition from partial information, and provide spatiotemporal constraints on theories of object recognition that involve recurrent processing.
Turalba AV, Pasquale LR. Hypertensive phase and early complications after Ahmed glaucoma valve implantation with intraoperative subtenon triamcinolone acetonide. Clin Ophthalmol 2014;8:1311-6.Abstract
OBJECTIVE: To evaluate intraoperative subtenon triamcinolone acetonide (TA) as an adjunct to Ahmed glaucoma valve (AGV) implantation. DESIGN: Retrospective comparative case series. PARTICIPANTS: Forty-two consecutive cases of uncontrolled glaucoma undergoing AGV implantation: 19 eyes receiving intraoperative subtenon TA and 23 eyes that did not receive TA. METHODS: A retrospective chart review was performed on consecutive pseudophakic adult patients with uncontrolled glaucoma undergoing AGV with and without intraoperative subtenon TA injection by a single surgeon. Clinical data were collected from 42 eyes and analyzed for the first 6 months after surgery. MAIN OUTCOME MEASURES: Primary outcomes included intraocular pressure (IOP) and number of glaucoma medications prior to and after AGV implantation. The hypertensive phase (HP) was defined as an IOP measurement of greater than 21 mmHg (with or without medications) during the 6-month postoperative period that was not a result of tube obstruction, retraction, or malfunction. Postoperative complications and visual acuity were analyzed as secondary outcome measures. RESULTS: Five out of 19 (26%) TA cases and 12 out of 23 (52%) non-TA cases developed the HP (P=0.027). Mean IOP (14.2±4.6 in TA cases versus [vs] 14.7±5.0 mmHg in non-TA cases; P=0.78), and number of glaucoma medications needed (1.8±1.3 in TA cases vs 1.6±1.1 in the comparison group; P=0.65) were similar between both groups at 6 months. Although rates of serious complications did not differ between the groups (13% in the TA group vs 16% in the non-TA group), early tube erosion (n=1) and bacterial endophthalmitis (n=1) were noted with TA but not in the non-TA group. CONCLUSIONS: Subtenon TA injection during AGV implantation may decrease the occurrence of the HP but does not alter the ultimate IOP outcome and may pose increased risk of serious complications within the first 6 months of surgery.
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Werdich XQ, Jakobiec FA, Curtin HD, Fay A. A clinical, radiologic, and immunopathologic study of five periorbital intraosseous cavernous vascular malformations. Am J Ophthalmol 2014;158(4):816-826.e1.Abstract

PURPOSE: To correlate the clinical, radiographic, histopathologic, and immunohistochemical features of 5 primary periorbital intraosseous cavernous vascular malformations. DESIGN: Retrospective interventional case series. METHODS: Clinical and operative records and radiographic images were reviewed. Histopathologic slides were evaluated with hematoxylin-eosin, trichrome, and elastin stains. Immunohistochemical studies were performed with a spectrum of monoclonal antibodies directed at antigens of vascular cells. RESULTS: Three men and 2 women ranged in age from 36 to 64 years. Vision was unaffected and there was no proptosis or globe displacement. The slow-growing lesions measured 13-25 mm in greatest diameter (mean 16.4 mm). Computed tomographic studies revealed that 2 lesions were situated in the maxillary bone, 2 in the frontal, and 1 in the zygoma, all anteriorly and with circumscribed, lucent, honeycombed, or sunburst characteristics. Histopathologically the lesions were composed of cavernous or telangiectatic channels; 1 showed advanced fibrotic vascular involution. Immunohistochemistry demonstrated CD31/34 positivity for vascular endothelium and D2-40 negativity for lymphatic endothelium. A typically thin mural myofibroblastic cuff was smooth muscle actin positive, weakly calponin positive, and desmin negative. Glucose transporter-1 and Ki-67 were negative in the endothelium. CONCLUSIONS: Intraosseous vascular lesions resemble orbital cavernous venous malformations (not true hemangiomas), except that their vascular walls are thinner owing to the constraints imposed by neighboring bone spicules, which limit the amount of interstitium from which mural myofibroblasts can be recruited. The bony trabeculae conferred the honeycomb or sunburst appearances observed radiographically. En bloc excision of these lesions was successful and avoided complications (mean follow-up, 46 months).

Wiggs JL, Langgurth AM, Allen KF. Carrier frequency of CYP1B1 mutations in the United States (an American Ophthalmological Society thesis). Trans Am Ophthalmol Soc 2014;112:94-102.Abstract
PURPOSE: CYP1B1 mutations cause autosomal recessive congenital glaucoma. Disease risk assessment for families with CYP1B1 mutations requires knowledge of the population mutation carrier frequency. The purpose of this study is to determine the CYP1B1 mutation carrier frequency in clinically normal individuals residing in the United States. Because CYP1B1 mutations can exhibit variable expressivity, we hypothesize that the mutation carrier frequency is higher than expected. METHODS: Two hundred fifty individuals without glaucoma or a family history of glaucoma were enrolled. CYP1B1 mutations were identified by DNA sequencing, and pathogenicity was estimated by PolyPhen-2 or a previous report of disease causality. RESULTS: Based on the disease frequency (1 in 10,000) and prevalence of CYP1B1-related congenital glaucoma (15% to 20%), the frequency of CYP1B1-related congenital glaucoma in the United States is approximately 1 in 50,000. Assuming Hardy-Weinberg equilibrium, the expected CYP1B1 mutation carrier frequency would be 1 in 112, or 0.89%. Among the 250 study participants, 11 (4.4%) are carriers of a single pathogenic mutation, representing a carrier frequency of 1 in 22, which is 5.1 times the expected frequency. A higher-than-expected carrier frequency (1 in 33, 3.0%) was also observed in 4300 white individuals sequenced by the National Heart Lung and Blood Institute Exome Sequencing Project. CONCLUSIONS: Our results show that the CYP1B1 mutation carrier frequency in the US population is between 1 in 22 and 1 in 33, which is 5.1 to 3.4 times the expected frequency. These results suggest that more individuals than expected are carriers of a deleterious CYP1B1 mutation, and that the prevalence of CYP1B1-related disease may be higher than expected.
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Yadav P, Jakobiec FA, De Castro DK, Mendoza PR, Fay A. Extruded, partially disintegrated, poly-HEMA orbital implant (AlphaSphere). Ophthalmic Plast Reconstr Surg 2014;30(4):e86-91.Abstract
A 54-year-old diabetic man underwent enucleation for endophthalmitis. Secondary implantation of a 2-hydroxyethyl methacrylate (HEMA) sphere (AlphaSphere, Addition Technology) was performed 2 weeks later. Six weeks after insertion, noninfectious disintegration of sutured tissue planes represented by Tenon's capsule, rectus muscle, and conjunctiva occurred, requiring removal of the fragmenting implant before uncontrolled extrusion occurred. Histopathologic analysis revealed an absence of infectious pathogens and no tissue necrosis, but rather breakup of the implant material that elicited a granulomatous response with sparse T-lymphocytes and almost no polymorphonuclear leukocytes. This distinctively designed poly-HEMA orbital implant incited a dramatic and irreversible host tissue response. Investigation of other cases will be necessary to determine the frequency of such a complication and should include rigorous histopathologic techniques.
Yamada T, Yang Y, Hemberg M, Yoshida T, Cho HY, Murphy PJ, Fioravante D, Regehr WG, Gygi SP, Georgopoulos K, Bonni A. Promoter decommissioning by the NuRD chromatin remodeling complex triggers synaptic connectivity in the mammalian brain. Neuron 2014;83(1):122-34.Abstract
Precise control of gene expression plays fundamental roles in brain development, but the roles of chromatin regulators in neuronal connectivity have remained poorly understood. We report that depletion of the NuRD complex by in vivo RNAi and conditional knockout of the core NuRD subunit Chd4 profoundly impairs the establishment of granule neuron parallel fiber/Purkinje cell synapses in the rodent cerebellar cortex in vivo. By interfacing genome-wide sequencing of transcripts and ChIP-seq analyses, we uncover a network of repressed genes and distinct histone modifications at target gene promoters that are developmentally regulated by the NuRD complex in the cerebellum in vivo. Finally, in a targeted in vivo RNAi screen of NuRD target genes, we identify a program of NuRD-repressed genes that operate as critical regulators of presynaptic differentiation in the cerebellar cortex. Our findings define NuRD-dependent promoter decommissioning as a developmentally regulated programming mechanism that drives synaptic connectivity in the mammalian brain.
Yanai R, Mulki L, Hasegawa E, Takeuchi K, Sweigard H, Suzuki J, Gaissert P, Vavvas DG, Sonoda K-H, Rothe M, Schunck W-H, Miller JW, Connor KM. Cytochrome P450-generated metabolites derived from ω-3 fatty acids attenuate neovascularization. Proc Natl Acad Sci U S A 2014;111(26):9603-8.Abstract
Ocular neovascularization, including age-related macular degeneration (AMD), is a primary cause of blindness in individuals of industrialized countries. With a projected increase in the prevalence of these blinding neovascular diseases, there is an urgent need for new pharmacological interventions for their treatment or prevention. Increasing evidence has implicated eicosanoid-like metabolites of long-chain polyunsaturated fatty acids (LCPUFAs) in the regulation of neovascular disease. In particular, metabolites generated by the cytochrome P450 (CYP)-epoxygenase pathway have been shown to be potent modulators of angiogenesis, making this pathway a reasonable previously unidentified target for intervention in neovascular ocular disease. Here we show that dietary supplementation with ω-3 LCPUFAs promotes regression of choroidal neovessels in a well-characterized mouse model of neovascular AMD. Leukocyte recruitment and adhesion molecule expression in choroidal neovascular lesions were down-regulated in mice fed ω-3 LCPUFAs. The serum of these mice showed increased levels of anti-inflammatory eicosanoids derived from eicosapentaenoic acid and docosahexaenoic acid. 17,18-epoxyeicosatetraenoic acid and 19,20-epoxydocosapentaenoic acid, the major CYP-generated metabolites of these primary ω-3 LCPUFAs, were identified as key lipid mediators of disease resolution. We conclude that CYP-derived bioactive lipid metabolites from ω-3 LCPUFAs are potent inhibitors of intraocular neovascular disease and show promising therapeutic potential for resolution of neovascular AMD.

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