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Sample records for cultured chick retinal

  1. Influence of melatonin on the development of functional nicotinic acetylcholine receptors in cultured chick retinal cells

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    L.F.S. Sampaio

    2005-04-01

    Full Text Available The influence of melatonin on the developmental pattern of functional nicotinic acetylcholine receptors was investigated in embryonic 8-day-old chick retinal cells in culture. The functional response to acetylcholine was measured in cultured retina cells by microphysiometry. The maximal functional response to acetylcholine increased 2.7 times between the 4th and 5th day in vitro (DIV4, DIV5, while the Bmax value for [125I]-alpha-bungarotoxin was reduced. Despite the presence of alpha8-like immunoreactivity at DIV4, functional responses mediated by alpha-bungarotoxin-sensitive nicotinic acetylcholine receptors were observed only at DIV5. Mecamylamine (100 µM was essentially without effect at DIV4 and DIV5, while dihydro-ß-erythroidine (10-100 µM blocked the response to acetylcholine (3.0 nM-2.0 µM only at DIV4, with no effect at DIV5. Inhibition of melatonin receptors with the antagonist luzindole, or melatonin synthesis by stimulation of D4 dopamine receptors blocked the appearance of the alpha-bungarotoxin-sensitive response at DIV5. Therefore, alpha-bungarotoxin-sensitive receptors were expressed in retinal cells as early as at DIV4, but they reacted to acetylcholine only after DIV5. The development of an alpha-bungarotoxin-sensitive response is dependent on the production of melatonin by the retinal culture. Melatonin, which is produced in a tonic manner by this culture, and is a key hormone in the temporal organization of vertebrates, also potentiates responses mediated by alpha-bungarotoxin-sensitive receptors in rat vas deferens and cerebellum. This common pattern of action on different cell models that express alpha-bungarotoxin-sensitive receptors probably reflects a more general mechanism of regulation of these receptors.

  2. Lipid-mediated gene transfection into chick embryo retinal cells in ovo and in vitro.

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    Toy, J; Bradford, R L; Adler, R

    2000-12-15

    Several lipofection reagents were tested on chick embryo retinal cultures using green fluorescent protein (GFP) as a reporter gene; best results were obtained with the GenePORTER (GP) reagent, which yielded approximately 4.4% of the cells with intense GFP fluorescence. Cell survival and structural differentiation appeared normal, but one of the immunocytochemical markers studied (visinin) was less frequently observed in GP-treated cultures. When similar plasmid-GP mixtures were injected into chick embryo eyes in ovo, bright GFP-fluorescent cells were observed in different retinal layers, without detectable detrimental effects on retinal morphology. Particularly extensive reporter gene expression was obtained upon intraocular injection of GP plus naked DNA from a RCAS retrovirus, which resulted in the development of abundant radial columns of alkaline phosphatase-positive cells, separated by columns of negative cells. We conclude that lipid-based transfection offers a quick, simple and fairly innocuous means for gene delivery into proliferating and postmitotic retinal cells, in vitro as well as in the developing eye in ovo, and that transfection of naked retroviral DNA can lead to extensive expression of foreign genes by retinal cells, bypassing the time-consuming steps required for the generation of high-titer virion stocks.

  3. Effect of peripheral nerve on the neurite growth from retinal explants in culture

    Institute of Scientific and Technical Information of China (English)

    LiuLi; SoKwokfai

    1990-01-01

    The effect of peripheral nerve (PN) on neurite outgrowth from retinal explants of adult hamsters was examined.Cultures of retinal explants,and co-cultures of retinal explants and PN were performed using chick retinal basement memebrane (BM) as substrate.The presence of PN increases the number and length of neurite outgrowth.In addition,a high proportion of neurites situated close to PN tend to grow towards it.Since there was no contact between retinal explants and PN,we suggest that PN might secete diffusible substances to attract the neurites to grow towards it.

  4. Analysis of retinal cell development in chick embryo by immunohistochemistry and in ovo electroporation techniques

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    Pashkova Anna

    2010-01-01

    Full Text Available Abstract Background Retinal cell development has been extensively investigated; however, the current knowledge of dynamic morphological and molecular changes is not yet complete. Results This study was aimed at revealing the dynamic morphological and molecular changes in retinal cell development during the embryonic stages using a new method of targeted retinal injection, in ovo electroporation, and immunohistochemistry techniques. A plasmid DNA that expresses the green fluorescent protein (GFP as a marker was delivered into the sub-retinal space to transfect the chick retinal stem/progenitor cells at embryonic day 3 (E3 or E4 with the aid of pulses of electric current. The transfected retinal tissues were analyzed at various stages during chick development from near the start of neurogenesis at E4 to near the end of neurogenesis at E18. The expression of GFP allowed for clear visualization of cell morphologies and retinal laminar locations for the indication of retinal cell identity. Immunohistochemistry using cell type-specific markers (e.g., Visinin, Xap-1, Lim1+2, Pkcα, NeuN, Pax6, Brn3a, Vimentin, etc. allowed further confirmation of retinal cell types. The composition of retinal cell types was then determined over time by counting the number of GFP-expressing cells observed with morphological characteristics specific to the various retinal cell types. Conclusion The new method of retinal injection and electroporation at E3 - E4 allows the visualization of all retinal cell types, including the late-born neurons, e.g., bipolar cells at a level of single cells, which has been difficult with a conventional method with injection and electroporation at E1.5. Based on data collected from analyses of cell morphology, laminar locations in the retina, immunohistochemistry, and cell counts of GFP-expressing cells, the time-line and dynamic morphological and molecular changes of retinal cell development were determined. These data provide more

  5. Evidence of muscarinic acetylcholine receptors in the retinal centrifugal system of the chick

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    Calaza K.C.

    2000-01-01

    Full Text Available In this study we characterize the presence of muscarinic acetylcholine receptors (mAChR in the isthmo-optic nucleus (ION of chicks by immunohistochemistry with the M35 antibody. Some M35-immunoreactive fibers were observed emerging from the retinal optic nerve insertion, suggesting that they could be centrifugal fibers. Indeed, intraocular injections of cholera toxin B (CTb, a retrograde tracer, and double-labeling with M35 and CTb in the ION confirmed this hypothesis. The presence of M35-immunoreactive cells and the possible mAChR expression in ION and ectopic neuron cells in the chick brain strongly suggest the existence of such a cholinergic system in this nucleus and that acetylcholine release from amacrine cells may mediate interactions between retinal cells and ION terminals.

  6. Protein expression profiling during chick retinal maturation: a proteomics-based approach

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    Stitt Alan W

    2008-12-01

    Full Text Available Abstract Background The underlying pathways that drive retinal neurogenesis and synaptogenesis are still relatively poorly understood. Protein expression analysis can provide direct insight into these complex developmental processes. The aim of this study was therefore to employ proteomic analysis to study the developing chick retina throughout embryonic (E development commencing at day 12 through 13, 17, 19 and post-hatch (P 1 and 33 days. Results 2D proteomic and mass spectrometric analysis detected an average of 1514 spots per gel with 15 spots demonstrating either modulation or constitutive expression identified via MS. Proteins identified included alpha and beta-tubulin, alpha enolase, B-creatine kinase, gamma-actin, platelet-activating factor (PAF, PREDICTED: similar to TGF-beta interacting protein 1, capping protein (actin filament muscle Z line, nucleophosmin 1 (NPM1, dimethylarginine dimethylaminohydrolase, triosphoaphate isomerase, DJ1, stathmin, fatty acid binding protein 7 (FABP7/B-FABP, beta-synuclein and enhancer of rudimentary homologue. Conclusion This study builds upon previous proteomic investigations of retinal development and represents the addition of a unique data set to those previously reported. Based on reported bioactivity some of the identified proteins are most likely to be important to normal retinal development in the chick. Continued analysis of the dynamic protein populations present at the early stages and throughout retinal development will increase our understanding of the molecular events underpinning retinogenesis.

  7. Transplantation of human neonatal foreskin stromal cells in ex vivo organotypic cultures of embryonic chick femurs

    DEFF Research Database (Denmark)

    Aldahmash, Abdullah; Vishnubalaji, Radhakrishnan

    2017-01-01

    NSSCs in ex vivo organotypic cultures of embryonic chick femurs. Isolated embryonic chick femurs (E10 and E11) were cultured for 10 days together with micro-mass cell pellets of hNSSCs, human umbilical vein endothelial cells (HUVEC) or a combination of the two cell types. Changes in femurs gross morphology...

  8. Myogenic potential of chick limb bud mesenchyme in micromass culture.

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    Archer, C W; Langille, R M; Teran, M A; Solursh, M

    1992-01-01

    The myogenic potential of chick limb mesenchyme from stages 18-25 was assessed by micromass culture under conditions conductive to myogenesis, and was measured as the proportion of differentiated (muscle myosin-positive) mononucleated cells detected. It was found that similar myogenic potentials existed in mesenchyme from whole limbs between stages 18 and 19, but this potential was halved by stage 20. At stage 21, proximal mesenchyme showed significantly more myogenesis than distal mesenchyme, but this difference was abolished by stage 22. Thereafter, myogenesis was increasingly restricted from the distal mesenchyme, whilst the potential in more proximal regions did not significantly increase after stage 23. When the ratio between total limb myoblasts which differentiated on days 1 and 4 of culture was analysed, it was found that two distinct peaks existed at stages 20 and 23. The significance of these ratio peaks is unclear, but may be related to different proliferative potentials of the pre-myoblasts at these stages.

  9. Efficiency of several cultural methods and a chick bioassay to recover dry stressed Campylobacter

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    The aims of the study were to evaluate the efficacy of 5 enrichment procedures for recovery of dry-atmospheric-temperature stressed C. jejuni and C. coli and determine the viable status of the non-culturable strains using a chick bioassay. Sterile chick paper pads (PP) and filter papers (FP) were i...

  10. Growth of cultured porcine retinal pigment epithelial cells

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    Wiencke, A.K.; Kiilgaard, Jens Folke; Nicolini, Jair;

    2003-01-01

    To establish and characterize cultures of porcine retinal pigment epithelial (pRPE) cells in order to produce confluent monolayers of cells for transplantation.......To establish and characterize cultures of porcine retinal pigment epithelial (pRPE) cells in order to produce confluent monolayers of cells for transplantation....

  11. Trivial or Commendable? : Women’s Writing, Popular Culture, and Chick Lit

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    Ryan, Mary

    2010-07-01

    Full Text Available There are a number of similarities between popular culture and women's writing: both have been dismissed as trivial and worthless, have traditionally received little respect from critics, and have been scorned because of theis apparently "low-brow" appeal. Additionally, both were long excluded from the literary Canon. In contemporary culture, the intersection of popular culture and women's writing takes the form of chick lit, the contemporary genre of fiction starring female characters in their 20s and 30s as they make their way through their lives and tackle all the obstacles in their way. As well as outlining the characteristics and history of chick lit, this paper will discuss the negative reception that popular culture, women's writing, and chick lit has often been subjected to, and will show how studies are now emerging with the aim of demonstrating how such genres may have more worth and potential than is typically suggested.

  12. AN EMBRYONIC CHICK PANCREAS ORGAN CULTURE MODEL: CHARACTERIZATION AND NEURAL CONTROL OF EXOCRINE RELEASE

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    An embryonic chick (Gallus domesticus) whole-organ pancreas culture system was developed for use as an in vitro model to study cholinergic regulation of exocrine pancreatic function. The culture system was examined for characteristic exocrine function and viability by measuring e...

  13. AN EMBRYONIC CHICK PANCREAS ORGAN CULTURE MODEL: CHARACTERIZATION AND NEURAL CONTROL OF EXOCRINE RELEASE

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    An embryonic chick (Gallus domesticus) whole-organ pancreas culture system was developed for use as an in vitro model to study cholinergic regulation of exocrine pancreatic function. The culture system was examined for characteristic exocrine function and viability by measuring e...

  14. Culturing of retinal pigment epithelium cells.

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    Valtink, Monika; Engelmann, Katrin

    2009-01-01

    The retinal pigment epithelium (RPE) is a monolayer of cells adjacent to the photoreceptors of the retina. It plays a crucial role in maintaining photoreceptor health and survival. Degeneration or dysfunction of the RPE can lead to photoreceptor degeneration and as a consequence to visual impairment. The most common diseased state of the RPE becomes manifest in age-related macular degeneration, an increasing cause of blindness in the elderly. RPE cells are therefore of great interest to researchers working in the field of tissue engineering and cell transplantation. In fact, studies in animal models have proven that the transplantation of RPE cells can delay the course of photoreceptor degenerative diseases. Although first attempts to transplant RPE cells into the subretinal space in human individuals suffering from age-related macular degeneration were less successful, RPE cell transplantation is still favored as a future therapeutic option, and much work is done to develop and design cell transplants. Cell banking is a prerequisite to have well-differentiated and characterized cells at hand when needed for research purposes, but also for therapeutic approaches. In this chapter the authors will describe methods to isolate, culture and preserve adult human RPE cells for the purpose of RPE cell banking. Copyright 2009 S. Karger AG, Basel.

  15. Chick ex ovo culture and ex ovo CAM assay: how it really works.

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    Dohle, Daniel S; Pasa, Susanne D; Gustmann, Sebastian; Laub, Markus; Wissler, Josef H; Jennissen, Herbert P; Dünker, Nicole

    2009-11-30

    Chicken eggs in the early phase of breeding are between in vitro and in vivo systems and provide a vascular test environment not only to study angiogenesis but also to study tumorigenesis. After the chick chorioallantoic membrane (CAM) has developed, its blood vessel network can be easily accessed, manipulated and observed and therefore provides an optimal setting for angiogenesis assays. Since the lymphoid system is not fully developed until late stages of incubation, the chick embryo serves as a naturally immunodeficient host capable of sustaining grafted tissues and cells without species-specific restrictions. In addition to nurturing developing allo- and xenografts, the CAM blood vessel network provides a uniquely supportive environment for tumor cell intravasation, dissemination, and vascular arrest and a repository where arrested cells extravasate to form micro metastatic foci. For experimental purposes, in most of the recent studies the CAM was exposed by cutting a window through the egg shell and experiments were carried out in ovo, resulting in significant limitations in the accessibility of the CAM and possibilities for observation and photo documentation of effects. When shell-less cultures of the chick embryo were used(1-4), no experimental details were provided and, if published at all, the survival rates of these cultures were low. We refined the method of ex ovo culture of chick embryos significantly by introducing a rationally controlled extrusion of the egg content. These ex ovo cultures enhance the accessibility of the CAM and chick embryo, enabling easy in vivo documentation of effects and facilitating experimental manipulation of the embryo. This allows the successful application to a large number of scientific questions: (1) As an improved angiogenesis assay(5,6), (2) an experimental set up for facilitated injections in the vitreous of the chick embryo eye(7-9), (3) as a test environment for dissemination and intravasation of dispersed tumor

  16. Rediscovering the chick embryo as a model to study retinal development

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    Vergara M Natalia

    2012-06-01

    Full Text Available Abstract The embryonic chick occupies a privileged place among animal models used in developmental studies. Its rapid development and accessibility for visualization and experimental manipulation are just some of the characteristics that have made it a vertebrate model of choice for more than two millennia. Until a few years ago, the inability to perform genetic manipulations constituted a major drawback of this system. However, the completion of the chicken genome project and the development of techniques to manipulate gene expression have allowed this classic animal model to enter the molecular age. Such techniques, combined with the embryological manipulations that this system is well known for, provide a unique toolkit to study the genetic basis of neural development. A major advantage of these approaches is that they permit targeted gene misexpression with extremely high spatiotemporal resolution and over a large range of developmental stages, allowing functional analysis at a level, speed and ease that is difficult to achieve in other systems. This article provides a general overview of the chick as a developmental model focusing more specifically on its application to the study of eye development. Special emphasis is given to the state of the art of the techniques that have made gene gain- and loss-of-function studies in this model a reality. In addition, we discuss some methodological considerations derived from our own experience that we believe will be beneficial to researchers working with this system.

  17. Responses of cultured neural retinal cells to substratum-bound laminin and other extracellular matrix molecules.

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    Adler, R; Jerdan, J; Hewitt, A T

    1985-11-01

    The responses of cultured chick embryo retinal neurons to several extracellular matrix molecules are described. Retinal cell suspensions in serum-free medium containing the "N1" supplement (J. E. Bottenstein, S. D. Skaper, S. Varon, and J. Sato, 1980, Exp. Cell Res. 125, 183-190) were seeded on tissue culture plastic surfaces pretreated with polyornithine (PORN) and with one of the factors to be tested. Substantial cell survival could be observed after 72 hr in vitro on PORN pretreated with serum or laminin, whereas most cells appeared to be degenerating on untreated PORN, PORN-fibronectin, and PORN-chondronectin. Cell attachment, although quantitatively similar for all these substrata, was temperature-dependent on serum and laminin but not on fibronectin or untreated PORN. In a short-term bioassay, neurite development was abundant on laminin, scarce on serum and fibronectin, and absent on PORN. No positive correlation between cell spreading and neurite production could be seen: cell spreading was more extensive on PORN and fibronectin than on laminin or serum, while on laminin-treated dishes, spreading was similar for neurite-bearing and non-neurite-bearing cells. Laminin effects on retinal neurons were clearly substratum dependent. When bound to tissue culture plastic, laminin showed a dose-dependent inhibitory effect on cell attachment and did not stimulate neurite development. PORN-bound laminin, on the other hand, did not affect cell attachment but caused marked stimulation of neurite development, suggesting that laminin conformation and/or the spatial distribution of active sites play an important role in the neurite-promoting function of this extracellular matrix molecule. Investigation of the embryonic retina with ELISA and immunocytochemical methods showed that laminin is present in this organ during development. Therefore, in vivo and in vitro observations are consistent with the possibility that laminin might influence neuronal development in the retina.

  18. FT-IR microscopic mappings of early mineralization in chick limb bud mesenchymal cell cultures

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    Boskey, A. L.; Camacho, N. P.; Mendelsohn, R.; Doty, S. B.; Binderman, I.

    1992-01-01

    Chick limb bud mesenchymal cells differentiate into chondrocytes and form a cartilaginous matrix in culture. In this study, the mineral formed in different areas within cultures supplemented with 4 mM inorganic phosphate, or 2.5, 5.0, and 10 mM beta-glycerophosphate (beta GP), was characterized by Fourier-transform infrared (FT-IR) microscopy. The relative mineral-to-matrix ratios, and distribution of crystal sizes at specific locations throughout the matrix were measured from day 14 to day 30. The only mineral phase detected was a poorly crystalline apatite. Cultures receiving 4 mM inorganic phosphate had smaller crystals which were less randomly distributed around the cartilage nodules than those in the beta GP-treated cultures. beta GP-induced mineral consisted of larger, more perfect apatite crystals. In cultures receiving 5 or 10 mM beta GP, the relative mineral-to-matrix ratios (calculated from the integrated intensities of the phosphate and amide I bands, respectively) were higher than in the cultures with 4 mM inorganic phosphate or in the in vivo calcified chick cartilage.

  19. Spaceflight effects on cultured embryonic chick bone cells

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    Landis, W. J.; Hodgens, K. J.; Block, D.; Toma, C. D.; Gerstenfeld, L. C.

    2000-01-01

    A model calcifying system of primary osteoblast cell cultures derived from normal embryonic chicken calvaria has been flown aboard the shuttle, Endeavour, during the National Aeronautics and Space Administration (NASA) mission STS-59 (April 9-20, 1994) to characterize unloading and other spaceflight effects on the bone cells. Aliquots of cells (approximately 7 x 10(6)) grown in Dulbecco's modified Eagle's medium (DMEM) + 10% fetal bovine serum (FBS) were mixed with microcarrier beads, inoculated into cartridge culture units of artificial hollow fiber capillaries, and carried on the shuttle. To promote cell differentiation, cartridge media were supplemented with 12.5 microg/ml ascorbate and 10 mM beta-glycerophosphate for varying time periods before and during flight. Four cartridges contained cells from 17-day-old embryos grown for 5 days in the presence of ascorbate prior to launch (defined as flight cells committed to the osteoblastic lineage) and four cartridges supported cells from 14-day-old embryos grown for 10 days with ascorbate before launch (uncommitted flight cells). Eight cartridges prepared in the same manner were maintained under normal gravity throughout the flight (control cells) and four additional identical cartridges under normal gravity were terminated on the day of launch (basal cells). From shuttle launch to landing, all cartridges were contained in closed hardware units maintaining 5% CO2, 37 degrees C, and media delivery at a rate of approximately 1.5 ml/6 h. During day 3 and day 5 of flight, duplicate aliquots of conditioned media and accumulated cell products were collected in both the flight and the control hardware units. At the mission end, comparisons among flight, basal, and control samples were made in cell metabolism, gene expression for type I collagen and osteocalcin, and ultrastructure. Both committed and uncommitted flight cells were metabolically active, as measured by glucose uptake and lactate production, at approximately the

  20. Regulation of phosphatidylcholine biosynthesis in cultured chick embryonic muscle treated with phospholipase C.

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    Sleight, R; Kent, C

    1980-11-25

    Cultures of embryonic chick muscle cells grown in medium containing phospholipase C from Clostridium perfringens incorporated [3H]choline into lipid at a rate 3- to 5-fold higher than control cultures. To determine the mechanism by which stimulation of phosphatidylcholine synthesis occurred in phospholipase C-treated cells, activities of enzymes and levels of intermediates in the biosynthetic pathway for phosphatidylcholine were examined. Activities of choline kinase, choline phosphotransferase, glycerol-3-phosphate dehydrogenase, glycerol-3-phosphate acyltransferase, acylglycerol-3-phosphate acyltransferase, and phosphatidic acid phosphatase in phospholipase C-treated cells were the same or only slightly higher than in control cells. CTP:phosphocholine cytidylyltransferase, on the other hand, was 3 times as active in homogenates from phospholipase C-treated cells. Levels of phosphocholine decreased and levels of CDP-choline increased in phospholipase C-treated cells, and a calculation of the disequilibrium ratio indicated that the cytidylyltransferase reaction was not at equilibrium. The cytidylyltransferase was, thus, identified as the regulatory enzyme for choline flux in these cells. The cytidylyltransferase was located in both the cytosolic and particulate fractions from cultured muscle cells and a much larger portion of enzyme activity was associated with the particulate fraction in cells treated with phospholipase C. Sonicated preparations of total chick lipids, phosphatidylethanolamine, and phosphatidylserine greatly stimulated the cytosolic cytidylyltransferase activity but had no effect on the particulate enzyme. Neither stimulation of incorporation of [3H]choline into lipid nor activation of the cytidylyltransferase was dependent on protein synthesis. A model for the mechanism of regulation of phosphatidylcholine synthesis in embryonic chick muscle is presented.

  1. Cadmium inhibition of vitamin D-mediated responses in organ-cultured embryonic chick duodenum

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    Corradino, R.A.

    1979-01-01

    When added to the medium, cadmium inhibits 1..cap alpha..,25-dihydroxycholecalciferol-mediated responses in the organ-cultured embryonic chick duodenum: decreases induction of a specific calcium-binding protein (CaBP), prevents the elevation of alkaline phosphatase activity, and reduces the ability of the tissue to absorb radiocalcium at the mucosal surface. The cadmium effect is clearly not generalized cytotoxicity. These results may be taken as evidence that cadmium can interfere with vitamin D action at the level of the target organ itself and is not necessarily secondary to alteration in vitamin D metabolism.

  2. Effects of Multivitamins and Known Teratogens on Chick Cardiomyocytes Micromass Culture Assay

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    Samreen Memon

    2013-09-01

    Full Text Available   Objective(s: This study aimed to find out whether the chick cardiomyocyte micromass (MM system could be employed to predict the teratogenecity of common environmental factors. Different multivitamins and over the counter drugs were used in this study.   Materials and Methods: White Leghorn 5-day-old embryo hearts were dissected and trypsinized to produce a cardiomyocyte cell suspension in Dulbecco's Modified Eagle's Medium. The cultures were incubated at 370C in 5% CO2 in air, and observations were made at 24, 48 and 144 hr, for the detection of cell beating. Cellular viability was assessed using the resazurin assay and cell protein content was assessed by the kenacid blue assay. It was observed that while not affecting total cell number folic acid, vitamin C, sodium fluoride and ginseng did not significantly reduced cell activity and beating. However cadmium chloride significantly reduced the beating, cell viability and cell protein content in micromass cultures. Results: The results demonstrate the potential of the chick cardiomyocyte MM culture assay to identify teratogens/embryotoxins that alter morphology and function, which may result in either teratogenic outcome or cytotoxicity. Conclusion: This could form part of a screen for developmental toxicity related to cardiac function

  3. The mechanism of beta-glycerophosphate action in mineralizing chick limb-bud mesenchymal cell cultures.

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    Boskey, A L; Guidon, P; Doty, S B; Stiner, D; Leboy, P; Binderman, I

    1996-11-01

    Differentiating chick limb-bud mesenchymal cells plated in micromass culture form a cartilage matrix that can be mineralized in the presence of 4 mM inorganic phosphate (Pi), and 1 mM calcium. Previous studies showed that when beta-glycerophosphate (beta GP) is used in place of Pi, the mineral crystals formed are larger and differ in distribution. The present study shows that the difference in distribution is not associated with alterations in cell proliferation, protein synthesis, or with collagen, proteoglycan core protein, or alkaline phosphatase gene expression. Cultures with 2.5, 5, and 10 mM beta GP did show different levels of alkaline phosphatase activity, and in the presence of low (0.3 mM) Ca had different Pi contents (4, 6 and 9 mM, respectively), indicating that the increase in CaxP product may in part be responsible for the altered pattern of mineralization. However, cultures with beta GP in which alkaline phosphatase activity was inhibited with levamisole still had an altered mineral distribution as revealed by Fourier transform-infrared (FT-IR) microspectroscopy. The presence of a casein kinase II-like activity in the mineralizing cultures, the ability of specific inhibitors of this enzyme to block mineralization, and the known ability of beta GP to block phosphoprotein phosphatase activity suggests that altered patterns of matrix protein phosphorylation may influence mineral deposition in these cultures.

  4. Methods for culturing retinal pigment epithelial cells: a review of current protocols and future recommendations

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    Aaron H Fronk

    2016-07-01

    Full Text Available The retinal pigment epithelium is an important part of the vertebrate eye, particularly in studying the causes and possible treatment of age-related macular degeneration. The retinal pigment epithelium is difficult to access in vivo due to its location at the back of the eye, making experimentation with age-related macular degeneration treatments problematic. An alternative to in vivo experimentation is cultivating the retinal pigment epithelium in vitro, a practice that has been going on since the 1970s, providing a wide range of retinal pigment epithelial culture protocols, each producing cells and tissue of varying degrees of similarity to natural retinal pigment epithelium. The purpose of this review is to provide researchers with a ready list of retinal pigment epithelial protocols, their effects on cultured tissue, and their specific possible applications. Protocols using human and animal retinal pigment epithelium cells, derived from tissue or cell lines, are discussed, and recommendations for future researchers included.

  5. Chick ex ovo culture and ex ovo CAM assay: how it really works

    National Research Council Canada - National Science Library

    Dohle, Daniel S; Pasa, Susanne D; Gustmann, Sebastian; Laub, Markus; Wissler, Josef H; Jennissen, Herbert P; Dünker, Nicole

    2009-01-01

    .... After the chick chorioallantoic membrane (CAM) has developed, its blood vessel network can be easily accessed, manipulated and observed and therefore provides an optimal setting for angiogenesis assays...

  6. Study of the cardiotoxic potential of pharmaceutical compounds in chick myocardial myocyte reaggregate cultures.

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    Seaman, C W; Toseland, C D; Maile, P A; Francis, I; White, D J

    1994-08-01

    Cardiotoxicity produced by doxorubicin in vivo is considered to be due to a direct effect on the myocardium and this is also a major component with toxicity of isoprenaline and digoxin. In the case of the cardiotoxicity produced at high doses by the antihypertensives hydralazine and pinacidil, an indirect mechanism operating by way of their exaggerated pharmacological effects is believed to be responsible. These compounds were examined for their cardiotoxic potential in vitro using chick myocardial myocyte reaggregate (MMR) cultures; allylamine HCl was used as a positive control. Cultures were incubated for up to 24 hr with each compound; parameters analysed were: spontaneous beating activity (SBA), lactate dehydrogenase (LDH) leakage and microscopic evidence of cytotoxicity. Allylamine, doxorubicin, digoxin and to a lesser extent isoprenaline were highly toxic to MMR cultures, as demonstrated by their effects on SBA, LDH leakage and morphology. Hydralazine showed very mild cytotoxicity at the highest concentrations with no LDH leakage; pinacidil was not cytotoxic but showed a dose-related inhibition of SBA. These results confirm the direct toxic action of doxorubicin and digoxin on myocardial cells and indicate that this is also an important mechanism in vivo for isoprenaline. The lack of any significant toxicity with hydralazine and pinacidil accords with an indirect mechanism based on their pharmacology.

  7. Culture of domestic cat ovarian tissue in vitro and in the chick embryo chorioallantoic membrane.

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    Vilela, J M V; Leonel, E C R; D'Oliveira, L; Paiva, R E G; Miranda-Vilela, A L; Amorim, C A; Pic-Taylor, A; Lucci, C M

    2016-10-15

    In vitro culture and transplantation procedures are essential protocols employed in the evaluation of ovarian follicle survival and development. Culture in the chorioallantoic membrane (CAM) of chick embryos is an intermediate method that provides important follicle development information and has not been tested for cat ovaries to date. The aim of this study was to investigate if in vitro and CAM culture could be used as short-term systems to study cat ovarian tissue development. The ovaries of eight cats were dissected into 3-mm(3) cubes, cultured in vitro and in CAM for up to 5 days, and stained with hematoxylin-eosin and Gomori trichrome. Cell proliferation was analyzed using anti-Ki67. Possible differences among groups were investigated by analysis of variance or the Kruskal-Wallis test followed by Bonferroni correction. The T-test or Wilcoxon test was used to verify differences between the CAM and IVC. Results revealed that 87.5% of all follicles were primordial during culture. The percentage of primordial follicles in the morphologically normal follicles (MNF) pool was always higher than 80%, with the exception of Day 3 of CAM culture, but the number of MNF reduced significantly from Day 0 (600 out of 777 follicles) to Day 5 in the CAM (91 out of 171) and IVC (296 out of 686). The number of primordial follicles in 1 mm(3) in Days 2, 3, and 5 in the CAM was significantly lower than that in the control (Day 0). No cellular proliferation was observed in culture. Vascularization occurred in the CAM culture, but with no association to follicular viability. In addition, both methods showed an increase in connective tissue during culture. Although no significant differences were observed in the percentage of MNF, there was a reduction in the total number of follicles, both for IVC and CAM-cultured ovarian tissue. Furthermore, anti-Ki67 did not stain any follicle after Day 0 in IVC or in CAM culture. Neither system was capable of promoting follicle growth and

  8. Effects of DDT and permethrin on neurite growth in cultured neurons of chick embryo brain and Lymnaea stagnalis.

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    Ferguson, C A; Audesirk, G

    1990-01-01

    The pesticides permethrin and 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT), dissolved in either ethanol (EtOH) or dimethylsulphoxide (DMSO), were studied to determine their effect on neurite growth from cultured neurons of Lymnaea stagnalis and embryonic chicks. Both of these toxins decreased the percentage of neurons growing neurites, mean neurite length, and number of neurites/cell in a dose-dependent manner. DMSO increased the toxicity of permethrin and DDT in L. stagnalis neurons. EtOH was not used as a solvent with the embryonic chick cultures. Pre-existing neurites of L. stagnalis neurons exposed to permethrin regressed in a dose- and time-dependent manner. These two toxins may affect neurite outgrowth through interference with intracellular calcium regulation.

  9. Clonal distribution of osteoprogenitor cells in cultured chick periostea: Functional relationship to bone formation

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    McCulloch, C.A.; Fair, C.A.; Tenenbaum, H.C.; Limeback, H.; Homareau, R. (Univ. of Toronto, Ontario (Canada))

    1990-08-01

    Folded explants of periosteum from embryonic chick calvaria form bone-like tissue when grown in the presence of ascorbic acid, organic phosphate, and dexamethasone. All osteoblast-like cells in these cultures arise de novo by differentiation of osteoprogenitor cells present in the periosteum. To study the spatial and functional relationships between bone formation and osteoprogenitor cells, cultures were continuously labeled with (3H)thymidine for periods of 1-5 days. Radioautographs of serial 2-microns plastic sections stained for alkaline phosphatase (AP) showed maximal labeling of 30% of fibroblastic (AP-negative) cells by 3 days while osteogenic cells (AP-positive) exhibited over 95% labeling by 5 days. No differential shifts in labeling indices, grain count histograms of fibroblastic and osteogenic cells or numbers of AP-positive cells were observed, indicating no significant recruitment of cells from the fibroblastic to the osteogenic compartment. Despite the continuous presence of (3H)thymidine, less than 35% of both osteoblasts and osteocytes were labeled at 5 days, indicating that only one-third of the osteoprogenitor cells had cycled prior to differentiation. Spatial clustering of (3H)thymidine-labeled cells was measured by computer-assisted morphometry and application of the Poisson distribution to assess contagion. Cluster size and number of labeled cells per cluster did not vary between 1-3 days, but the number of clusters increased 20-fold between Day 1 and Day 3. Three-dimensional reconstruction from serial sections showed that clusters formed long, tubular arrays of osteogenic cells up to eight cells in length and located within 2-3 cell layers from the bone surface. Selective killing of S-phase cells with two pulse labels of high specific activity (3H)thymidine at 1 and 2 days of culture completely blocked bone formation.

  10. The impact of caffeine on connexin expression in the embryonic chick cardiomyocyte micromass culture system.

    Science.gov (United States)

    Ahir, Bhavesh K; Pratten, Margaret K

    2016-07-01

    Cardiomyocytes are electrically coupled by gap junctions, defined as clusters of low-resistance multisubunit transmembrane channels composed of connexins (Cxs). The expression of Cx40, Cx43 and Cx45, which are present in cardiomyocytes, is known to be developmentally regulated. This study investigates the premise that alterations in gap junction proteins are one of the mechanisms by which teratogens may act. Specifically, those molecules known to be teratogenic in humans could cause their effects via disruption of cell-to-cell communication pathways, resulting in an inability to co-ordinate tissue development. Caffeine significantly inhibited contractile activity at concentrations above and including 1500 μm (P caffeine on key cardiac gap junction protein (Cx40, Cx43 and Cx45) expression were analysed using immunocytochemistry and in-cell Western blotting. The results indicated that caffeine altered the expression pattern of Cx40, Cx43 and Cx45 at non-cytotoxic concentrations (≥2000 μm), i.e., at concentrations that did not affect total cell protein and cell viability. In addition the effects of caffeine on cardiomyocyte formation and function (contractile activity score) were correlated with modulation of Cxs (Cx40, Cx43 and Cx45) expression, at above and including 2000 μm caffeine concentrations (P < 0.05). These experiments provide evidence that embryonic chick cardiomyocyte micromass culture may be a useful in vitro method for mechanistic studies of perturbation of embryonic heart development. Copyright © 2015 John Wiley & Sons, Ltd.

  11. [The creatine effect on RNA and protein synthesis in growing culture of chick embryo myoblasts].

    Science.gov (United States)

    Zilber, M L; Litvinova, V N; Morozov, V I; Pliskin, A V; Pshendin, A I; Rogozkin, V A

    1975-01-01

    4hr incubation of the growing culture of chick embrio myoblasts in the presence of 5 mM creatine resulted, regardless of a well-defined lowering of cell membrane permeability to labelled precursors, in: (1) the 1.5-fold induction of 14C-orotic acid incorporation into total cellular RNA; (2) the 1.9-fold stimulation of DNA-dependent RNA-polymerase activity and (3) the preferable, in comparison with total proteins, 14C-leucine incorporation in the myosin heavy chain. The stimulating effect of creatine on RNA-poly-merase deals with a definite enzyme fraction and it is caused by the augmentation of the transcriptional complex enzyme activity. Polyacrilamide gel electrophoresis of total 14C-RNA revealed a relative increase of radioactivity after creatine treatment in both high-molecular pike and the fraction corresponding to 26S RNA, the relative proportion of mRNA containing Poly-A in the composition of total cellular RNA being invariable. The data obtained show that, though creatine as a positive regulator manifestates its effect at different stages of the sucessive chain of reactions leading to muscular protein synthesis, the direct realization of creatine regulatory function is connected with nucleus and is fullfilled at the transcription level.

  12. Primary Retinal Cultures as a Tool for Modeling Diabetic Retinopathy: An Overview

    Science.gov (United States)

    Varano, Monica; Mallozzi, Cinzia; Gaddini, Lucia; Formisano, Giuseppe; Pricci, Flavia

    2015-01-01

    Experimental models of diabetic retinopathy (DR) have had a crucial role in the comprehension of the pathophysiology of the disease and the identification of new therapeutic strategies. Most of these studies have been conducted in vivo, in animal models. However, a significant contribution has also been provided by studies on retinal cultures, especially regarding the effects of the potentially toxic components of the diabetic milieu on retinal cell homeostasis, the characterization of the mechanisms on the basis of retinal damage, and the identification of potentially protective molecules. In this review, we highlight the contribution given by primary retinal cultures to the study of DR, focusing on early neuroglial impairment. We also speculate on possible themes into which studies based on retinal cell cultures could provide deeper insight. PMID:25688355

  13. Primary Retinal Cultures as a Tool for Modeling Diabetic Retinopathy: An Overview

    Directory of Open Access Journals (Sweden)

    Andrea Matteucci

    2015-01-01

    Full Text Available Experimental models of diabetic retinopathy (DR have had a crucial role in the comprehension of the pathophysiology of the disease and the identification of new therapeutic strategies. Most of these studies have been conducted in vivo, in animal models. However, a significant contribution has also been provided by studies on retinal cultures, especially regarding the effects of the potentially toxic components of the diabetic milieu on retinal cell homeostasis, the characterization of the mechanisms on the basis of retinal damage, and the identification of potentially protective molecules. In this review, we highlight the contribution given by primary retinal cultures to the study of DR, focusing on early neuroglial impairment. We also speculate on possible themes into which studies based on retinal cell cultures could provide deeper insight.

  14. An evaluation of a novel chick cardiomyocyte micromass culture assay with two teratogens/embryotoxins associated with heart defects.

    Science.gov (United States)

    Hurst, Helena S; Clothier, Richard H; Pratten, Margaret

    2007-10-01

    This study was aimed at determining whether the chick cardiomyocyte micromass (MM) system could be employed to predict the teratogenicity/embryotoxicity of exogenous chemicals. Two documented teratogens/embryotoxins, sodium valproate (the sodium salt of valproic acid; VPA) and all-trans retinoic acid (tRA), were used in the initial phase of the study. White Leghorn 5-day-old embryo hearts were dissociated to produce a cardiomyocyte suspension in Dulbecco's Modified Eagle's Medium. Cultures were incubated at 37 degrees C in 5% CO(2) in air, and observations were made every 24 hours over 5 days, for the detection of beating. Culture viability was assessed by using the resazurin reduction assay for determining culture activity and the kenacid blue assay for determining cell number. It was found that tRA significantly reduced cell activity and beating, whilst not affecting total cell number. VPA up to 500 microM induced no cytotoxicity in the MM cardiomyocyte cultures, whilst all the VPA concentrations tested reduced beating. The results demonstrate the potential of the chick cardiomyocyte MM culture assay to identify teratogens/embryotoxins that alter functionality, which may result in a teratogenic outcome, whilst not causing cytotoxicity (direct embryotoxicity). This could form part of a screen for developmental toxicity related to cardiac function, whilst limb cultures and brain cultures based on the same system could be relevant to teratogenic effects on those tissues.

  15. An analysis of the growth of the retinal cell population in embryonic chicks yielding proliferative ratios, numbers of proliferative and non-proliferative cells and cell-cycle times for successive generations of cell cycles.

    Science.gov (United States)

    Morris, V B; Cowan, R

    1995-07-01

    Growth curves of the retinal cell population of embryonic chicks were fitted by a branching-process model of cell population growth, thereby estimating the proliferative ratios and mean cell-cycle times of the generations of cell cycles that underlie retinal growth. The proliferative ratio determines the proportion of cells that divides in the next generation, so the numbers of proliferative and non-proliferative cells in each generation of cell cycles were obtained. The mean cell-cycle times determine the times over which the generations are extant. Assuming growth starts from one cell in generation 0, the proliferative cells reach 3.6 x 10(6) and the non-proliferative cells reach 1.1 x 10(6) by generation 23. The next four generations increase the proliferative cell numbers to 13.9 x 10(6) and produce 20.1 x 10(6) non-proliferative cells. In the next five generations in the end phase of growth, non-proliferative cells are produced in large numbers at an average of 13.9 x 10(6) cells per generation as the retinal lineages are completed. The retinal cell population reaches a maximum estimated here at 98.2 x 10(6) cells. The mean cell-cycle time estimates range between 6.8 and 10.1 h in generations before the end phase of growth and between 10.6 and 17.2 h in generations in the end phase. The retinal cell population growth is limited by the depletion of the proliferative cell population that the production of non-proliferative cells entails. The proliferative ratios and the cell-cycle-time distribution parameters are the likely determinants of retinal growth rates. The results are discussed in relation to other results of spatial and temporal patterns of the cessation of cell cycling in the embryonic chick retina.

  16. Effects of proteoglycan modification on mineral formation in a differentiating chick limb-bud mesenchymal cell culture system.

    Science.gov (United States)

    Boskey, A L; Stiner, D; Binderman, I; Doty, S B

    1997-03-15

    In the presence of 4 mM inorganic phosphate, differentiating chick limb-bud mesenchymal cells plated in micromass cultures form a mineralized matrix resembling that of chick calcified cartilage. To test the hypothesis that cartilage proteoglycans are inhibitors of cell mediated mineralization, the synthesis, content, and turnover of proteoglycans were altered in this system, and the extent of mineralization and properties of the mineral crystals examined. In all cases where the proteoglycan synthesis or proteoglycans present were modified to provide fewer or smaller molecules, mineralization was enhanced. Specifically, when proteoglycan synthesis was blocked by treatment with 10(-10) M retinoic acid, extensive mineral deposition occurred on a matrix devoid of both proteoglycans and cartilage nodules. The crystals, which formed rapidly, were relatively large in size based on analysis by X-ray diffraction or FT-1R microspectroscopy, and were more abundant than in controls. When 2.5 or 5 mM xylosides were used to cause the synthesis of smaller proteoglycans, the extent of mineral accretion was also increased relative to controls; however, the matrix was less affected, and the extent of mineral deposition and the size of the crystals were not as markedly altered as in the case of retinoic acid. Modification of existing proteoglycans by either chondroinase ABC or hyaluronidase treatment similarly resulted in increased mineral accretion (based on 45Ca uptake or total Ca uptake) relative to cultures in which the proteoglycan content was not manipulated. Crystals were more abundant and larger than in control mineralizing cultures. In contrast, when proteoglycan degradation by metalloproteases was inhibited by metal chelation with o-phenanthroline, the Ca accretion at early time points was increased, but as mineralization progressed, Ca accumulation decreased. These data provide evidence that in this culture system, proteoglycans are inhibitors of mineralization.

  17. Evaluation of ultraviolet light toxicity on cultured retinal pigment epithelial and retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    Sankarathi Balaiya

    2010-01-01

    Full Text Available Sankarathi Balaiya, Ravi K Murthy, Vikram S Brar, Kakarla V ChalamDepartment of Ophthalmology, University of Florida College of Medicine, Jacksonville, FL, USAPurpose: Our study is aimed at evaluating the role of UVB light in inducing cytotoxicity in an in vitro model.Methods: RGC-5 and ARPE-19 cells were exposed to different time periods of UVB light: 0, 15, 30, and 45 min. They were subsequently examined for changes in cell morphology, cell viability (neutral red uptake assay, generation of reactive oxygen species (ROS, expression of bax, bcl-2 and cytochome C by reverse transcriptase polymerase chain reaction and western blot, respectively.Results: Dose-dependent reduction in cell viability to UVB light was demonstrated with parallel increase in ROS. Increased duration of exposure (>15 minutes, was associated with increased expression of bax and cytochrome C, and absence of bcl-2 expression.Conclusion: UVB light exposure results in cell cytotoxicity. The concomitant generation of ROS and expression of apoptotic markers suggests the role of oxidative stress in UVB-mediated apoptosis in an in vitro model of retinal ganglion and pigment epithelial cells.Keywords: ultraviolet light, retinal pigment epithelium, retinal ganglion cell, reactive oxygen species, cytochrome C

  18. A new take on an old story: chick limb organ culture for skeletal niche development and regenerative medicine evaluation

    Directory of Open Access Journals (Sweden)

    EL Smith

    2013-09-01

    Full Text Available Scientific research and progress, particularly in the drug discovery and regenerative medicine fields, is typically dependent on suitable animal models to develop new and improved clinical therapies for injuries and diseases. In vivo model systems are frequently utilised, but these models are expensive, highly complex and pose a number of ethical considerations leading to the development and use of a number of alternative ex vivo model systems. The ex vivo embryonic chick long bone and limb bud models have been utilised in the scientific research field as a model to understand skeletal development for over eighty years. The rapid development of avian skeletal tissues, coupled with the ease of experimental manipulation, availability of genome sequence and the presence of multiple cell and tissue types has seen such model systems gain significant research interest in the last few years in the tissue engineering field. The models have been explored both as systems for understanding the developmental bone niche and as potential testing tools for tissue engineering strategies for bone repair and regeneration. This review details the evolution of the chick limb organ culture system and presents recent innovative developments and emerging techniques and technologies applied to these models that are aiding our understanding of skeletal developmental and regenerative medicine research and application.

  19. Uroporphyria development in cultured chick embryo fibroblasts long-term treated with chloramphenicol and ethidium bromide.

    Science.gov (United States)

    de Muys, J M; Morais, R

    1984-07-23

    Long-term chloramphenicol- and ethidium bromide-treated chick embryo fibroblasts synthesize large amounts of porphyrins from exogenously added delta-aminolevulinic acid. The porphyrins consist mainly of uro- and heptacarboxyporphyrins and are retained within cells. Uroporphyria development is a time-dependent process which accompanies a step-wise decrease in the capacity of the mitochondrial respiratory chain. Upon removal of chloramphenicol from the medium, the pattern of porphyrin production readily returns to normal (mainly proto- and coproporphyrins found in the medium) while ethidium bromide-treated cells remain uroporphyric. The results suggest that impairment of mitochondrial functions in chicken by xenobiotics leads to uroporphyria development.

  20. Stable, position-related responses to retinoic acid by chick limb-bud mesenchymal cells in serum-free cultures.

    Science.gov (United States)

    Paulsen, D F; Solursh, M; Langille, R M; Pang, L; Chen, W D

    1994-03-01

    Retinoic acid (RA) has dramatic effects on limb-skeletal patterning in vivo and may well play a pivotal role in normal limb morphogenesis. RA's effects on the expression of pattern-related genes in the developing limb are probably mediated by cytoplasmic RA-binding proteins and nuclear RA-receptors. Little is known, however, about how RA modifies specific cellular behaviors required for skeletal morphogenesis. Earlier studies supported a role for regional differences in RA concentration in generating the region-specific cell behaviors that lead to pattern formation. The present study explores the possibility that position-related, cell-autonomous differences in the way limb mesenchymal cells respond to RA might have a role in generating pattern-related cell behavior. Mesenchymal cells from different proximodistal regions of stage 21-22 and 23-24 chick wing-buds were grown in chemically defined medium and exposed to 5 or 50 ng/ml of RA for 4 days in high-density microtiter cultures. The effects of RA on chondrogenesis in these cultures clearly differed depending on the limb region from which the cells were isolated. Regional differences in RA's effects on growth over 4 days in these cultures were less striking. The region-dependent responses of these cells to RA proved relatively stable in culture despite ongoing cytodifferentiation. This serum-free culture model will be useful in exploring the mechanisms underlying the region-dependent responsiveness of these cells to RA.

  1. A method for the isolation and culture of adult rat retinal pigment epithelial (RPE cells to study retinal diseases

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    Janosch Peter Heller

    2015-11-01

    Full Text Available Diseases such as age-related macular degeneration (AMD affect the retinal pigment epithelium (RPE and lead to the death of the epithelial cells and ultimately blindness. RPE transplantation is currently a major focus of eye research and clinical trials using human stem cell-derived RPE cells are ongoing. However, it remains to be established to which extent the source of RPE cells for transplantation affects their therapeutic efficacy and this needs to be explored in animal models. Autotransplantation of RPE cells has attractions as a therapy, but existing protocols to isolate adult RPE cells from rodents are technically difficult, time-consuming, have a low yield and are not optimized for long-term cell culturing. Here, we report a newly devised protocol which facilitates reliable and simple isolation and culture of RPE cells from adult rats. Incubation of a whole rat eyeball in 20 U/ml papain solution for 50 minutes yielded 4 x 104 viable RPE cells. These cells were hexagonal and pigmented upon culture. Using immunostaining, we demonstrated that the cells expressed RPE cell-specific marker proteins including cytokeratin 18 and RPE65, similar to RPE cells in vivo. Additionally, the cells were able to produce and secrete Bruch’s membrane matrix components similar to in vivo situation. Similarly, the cultured RPE cells adhered to isolated Bruch’s membrane as has previously been reported. Therefore, the protocol described in this article provides an efficient method for the rapid and easy isolation of high quantities of adult rat RPE cells. This provides a reliable platform for studying the therapeutic targets, testing the effects of drugs in a preclinical setup and to perform in vitro and in vivo transplantation experiments to study retinal diseases.

  2. VSX2 and ASCL1 Are Indicators of Neurogenic Competence in Human Retinal Progenitor Cultures.

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    Lynda S Wright

    Full Text Available Three dimensional (3D culture techniques are frequently used for CNS tissue modeling and organoid production, including generation of retina-like tissues. A proposed advantage of these 3D systems is their potential to more closely approximate in vivo cellular microenvironments, which could translate into improved manufacture and/or maintenance of neuronal populations. Visual System Homeobox 2 (VSX2 labels all multipotent retinal progenitor cells (RPCs and is known to play important roles in retinal development. In contrast, the proneural transcription factor Acheate scute-like 1 (ASCL1 is expressed transiently in a subset of RPCs, but is required for the production of most retinal neurons. Therefore, we asked whether the presence of VSX2 and ASCL1 could gauge neurogenic potential in 3D retinal cultures derived from human prenatal tissue or ES cells (hESCs. Short term prenatal 3D retinal cultures displayed multiple characteristics of human RPCs (hRPCs found in situ, including robust expression of VSX2. Upon initiation of hRPC differentiation, there was a small increase in co-labeling of VSX2+ cells with ASCL1, along with a modest increase in the number of PKCα+ neurons. However, 3D prenatal retinal cultures lost expression of VSX2 and ASCL1 over time while concurrently becoming refractory to neuronal differentiation. Conversely, 3D optic vesicles derived from hESCs (hESC-OVs maintained a robust VSX2+ hRPC population that could spontaneously co-express ASCL1 and generate photoreceptors and other retinal neurons for an extended period of time. These results show that VSX2 and ASCL1 can serve as markers for neurogenic potential in cultured hRPCs. Furthermore, unlike hESC-OVs, maintenance of 3D structure does not independently convey an advantage in the culture of prenatal hRPCs, further illustrating differences in the survival and differentiation requirements of hRPCs extracted from native tissue vs. those generated entirely in vitro.

  3. Human organotypic retinal cultures (HORCs) as a chronic experimental model for investigation of retinal ganglion cell degeneration.

    Science.gov (United States)

    Osborne, Andrew; Hopes, Marina; Wright, Phillip; Broadway, David C; Sanderson, Julie

    2016-02-01

    There is a growing need for models of human diseases that utilise native, donated human tissue in order to model disease processes and develop novel therapeutic strategies. In this paper we assessed the suitability of adult human retinal explants as a potential model of chronic retinal ganglion cell (RGC) degeneration. Our results confirmed that RGC markers commonly used in rodent studies (NeuN, βIII Tubulin and Thy-1) were appropriate for labelling human RGCs and followed the expected differential expression patterns across, as well as throughout, the macular and para-macular regions of the retina. Furthermore, we showed that neither donor age nor post-mortem time (within 24 h) significantly affected the initial expression levels of RGC markers. In addition, the feasibility of using human post mortem donor tissue as a long-term model of RGC degeneration was determined with RGC protein being detectable up to 4 weeks in culture with an associated decline in RGC mRNA and significant, progressive, apoptotic labelling of NeuN(+) cells. Differences in RGC apoptosis might have been influenced by medium compositions indicating that media constituents could play a role in supporting axotomised RGCs. We propose that using ex vivo human explants may prove to be a useful model for testing the effectiveness of neuroprotective strategies.

  4. A simple method for screening photoelectric dyes towards their use for retinal prostheses.

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    Matsuo T

    2003-10-01

    Full Text Available Photoelectric dyes absorb light and convert photon energy to electric potentials. To test whether these dyes could be used for retinal prostheses, a simple in vitro screening system was developed. Retinal neurons were cultured from the eyes of chick embryos at the 10-day embryonic stage, at which time no retinal photoreceptor cells have yet developed. Intracellular calcium elevation was observed with Fluo-4 in cultured retinal neurons before and after photoelectric dye was applied at varying concentrations to the culture medium. Five of 7 photoelectric dyes tested in this in vitro system induced intracellular calcium elevation in cultured chick retinal neurons. The intracellular calcium elevation generated by the 5 photoelectric dyes was blocked by extracellular calcium depletion in the case of all 5 dyes, and, except for one dye, by the presence of voltage-gated calcium channel blockers. The photoelectric dyes absorbed light under an inverted microscope and stimulated retinal neurons. This simple in vitro system allows the screening of photoelectric dyes which can be used for retinal prostheses.

  5. Alginate as a cell culture substrate for growth and differentiation of human retinal pigment epithelial cells.

    Science.gov (United States)

    Heidari, Razeih; Soheili, Zahra-Soheila; Samiei, Shahram; Ahmadieh, Hamid; Davari, Maliheh; Nazemroaya, Fatemeh; Bagheri, Abouzar; Deezagi, Abdolkhalegh

    2015-03-01

    The purpose of this study was to evaluate retinal pigment epithelium (RPE) cells' behavior in alginate beads that establish 3D environment for cellular growth and mimic extracellular matrix versus the conventional 2D monolayer culture. RPE cells were encapsulated in alginate beads by dripping alginate cell suspension into CaCl2 solution. Beads were suspended in three different media including Dulbecco's modified Eagle's medium (DMEM)/F12 alone, DMEM/F12 supplemented with 10 % fetal bovine serum (FBS), and DMEM/F12 supplemented with 30 % human amniotic fluid (HAF). RPE cells were cultivated on polystyrene under the same conditions as controls. Cell phenotype, cell proliferation, cell death, and MTT assay, immunocytochemistry, and real-time RT-PCR were performed to evaluate the effect of alginate on RPE cells characteristics and integrity. RPE cells can survive and proliferate in alginate matrixes. Immunocytochemistry analysis exhibited Nestin, RPE65, and cytokeratin expressions in a reasonable number of cultured cells in alginate beads. Real-time PCR data demonstrated high levels of Nestin, CHX10, RPE65, and tyrosinase gene expressions in RPE cells immobilized in alginate when compared to 2D monolayer culture systems. The results suggest that alginate can be used as a reliable scaffold for maintenance of RPE cells' integrity and in vitro propagation of human retinal progenitor cells for cell replacement therapies in retinal diseases.

  6. Peptide- and collagen-based hydrogel substrates for in vitro culture of chick cochleae.

    Science.gov (United States)

    Spencer, Nathaniel J; Cotanche, Douglas A; Klapperich, Catherine M

    2008-03-01

    The overall goal of this work is to improve the culture of the auditory organ of birds for the dual use of developing a hair cell regeneration model and charting a pathway to the eventual replacement of the hearing organ. In doing so, we develop a protocol for removing the auditory organ from its basement membrane in the inner ear, attach the organ to a series of artificial basement membranes, and conduct qualitative and quantitative analysis of how cell morphology, viability and function change with time. Native matrix cultures, where the epithelium was floating in media with the basement membrane and accessory structures attached, were used as a basis of comparison. PuraMatrix, collagen I, collagen I/chondroitin-sulfate and Matrigel were chosen to encompass a diverse range of mechanical properties and macromolecule moieties. Surprisingly, we find that PuraMatrix outperformed the other matrices as a scaffold for sensory organ culture. PuraMatrix a self-assembled peptide hydrogel, is a biochemically specific culture substrate that contains none of the extracellular matrix (ECM) molecules and growth factors contained in the inner ear's basement membrane. Rheological measurements reveal that PuraMatrix may be a closer approximation to the stiffness of the soft tissue supporting the auditory organ. Cell density on the PuraMatrix substrate is comparable to that of the native matrix cultures, despite the absence of the basement membrane and accessory structures. Further studies show that PuraMatrix supports the culture of functional hair cells over a 72 h period, with a significant increase in the number of functional hair cells in comparison to the organ cultured without a matrix. This is the first example of adhesion of the adult auditory epithelium to a biomaterial for an extended period of time. With further optimization, this system will enable the performance of many novel biophysical and pharmacological studies involving hair cells and supporting cells.

  7. Comparative effects of posterior eye cup tissues from myopic and hyperopic chick eyes on cultured scleral fibroblasts.

    Science.gov (United States)

    Christian, Parul G; Harkin, Damien G; Rayner, Cassie; Schmid, Katrina L

    2013-02-01

    The role of individual ocular tissues in mediating changes to the sclera during myopia development is unclear. The aim of this study was to examine the effects of retina, RPE and choroidal tissues from myopic and hyperopic chick eyes on the DNA and glycosaminoglycan (GAG) content in cultures of chick scleral fibroblasts. Primary cultures of fibroblastic cells expressing vimentin and α-smooth muscle actin were established in serum-supplemented growth medium from 8-day-old normal chick sclera. The fibroblasts were subsequently co-cultured with posterior eye cup tissue (full thickness containing retina, RPE and choroid) obtained from untreated eyes and eyes wearing translucent diffusers (form-deprivation myopia, FDM) or -15D lenses (lens-induced myopia, LIM) for 3 days (post-hatch day 5-8) (n = 6 per treatment group). The effect of tissues (full thickness and individual retina, RPE, and choroid layers) from -15D (LIM) versus +15D (lens-induced hyperopia, LIH) treated eyes was also determined. Refraction changes in the direction predicted by the visual treatments were confirmed by retinoscopy prior to tissue collection. Glycosaminoglycan (GAG) and DNA content of the scleral fibroblast cultures were measured using GAG and PicoGreen assays. There was no significant difference in the effect of full thickness tissue from either FDM or LIM treated eyes on DNA and GAG content of scleral fibroblasts (DNA 8.9 ± 2.6 μg and 8.4 ± 1.1 μg, p = 0.12; GAG 11.2 ± 0.6 μg and 10.1 ± 1.0 μg, p = 0.34). Retina from LIM eyes did not alter fibroblast DNA or GAG content compared to retina from LIH eyes (DNA 27.2 ± 1.7 μg versus 23.2 ± 1.5 μg, p = 0.21; GAG 28.1 ± 1.7 μg versus. 28.7 ± 1.2 μg, p = 0.46). Similarly, the choroid from LIH and LIM eyes did not produce a differential effect on DNA content (DNA LIM 46.9 ± 6.4 versus LIH 51.5 ± 4.7 μg, p = 0.31). In contrast, scleral fibroblast DNA was greater in co-culture with RPE from LIM eyes than the empty basket and DNA

  8. Modification of Isolation and Culture of Human Retinal Pigment Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    ZhengJL; GuoY

    1999-01-01

    Purpose:To modify the isolation of human retinal pigment pithelial(RPE)cells and to increase the purification and production of cultured RPE cells.Methods:The human eyecups were fixed on a fubber holder.After digestion by trypsin,RPE cells were collected,then cultured and identified by morphology,immunohistochemistry and electron microscopy.Results:The cultured RPE cells grew actively in the early stage with transparent nucleus and abundant melanin particles in cytoplasm.These cells were positive in DOPA oxidase reaction and in anti-pancytokeratin antibody staining.Cellular microvilli and tight junctions could be seen through transmission electrom microscopy.Conclusion:We developed a rubber holder to fix the eyecup.Using this holder,more and purer cultured RPE cells can be obtained.These cultured REP cells are similar to those in vivo in morphology and immunohistochemical staining.

  9. Involvement of nucleotides in glial growth following scratch injury in avian retinal cell monolayer cultures.

    Science.gov (United States)

    Silva, Thayane Martins; França, Guilherme Rapozeiro; Ornelas, Isis Moraes; Loiola, Erick Correia; Ulrich, Henning; Ventura, Ana Lucia Marques

    2015-06-01

    When retinal cell cultures were mechanically scratched, cell growth over the empty area was observed. Only dividing and migrating, 2 M6-positive glial cells were detected. Incubation of cultures with apyrase (APY), suramin, or Reactive Blue 2 (RB-2), but not MRS 2179, significantly attenuated the growth of glial cells, suggesting that nucleotide receptors other than P2Y1 are involved in the growth of glial cells. UTPγS but not ADPβS antagonized apyrase-induced growth inhibition in scratched cultures, suggesting the participation of UTP-sensitive receptors. No decrease in proliferating cell nuclear antigen (PCNA(+)) cells was observed at the border of the scratch in apyrase-treated cultures, suggesting that glial proliferation was not affected. In apyrase-treated cultures, glial cytoplasm protrusions were smaller and unstable. Actin filaments were less organized and alfa-tubulin-labeled microtubules were mainly parallel to scratch. In contrast to control cultures, very few vinculin-labeled adhesion sites could be noticed in these cultures. Increased Akt and ERK phosphorylation was observed in UTP-treated cultures, effect that was inhibited by SRC inhibitor 1 and PI3K blocker LY294002. These inhibitors and the FAK inhibitor PF573228 also decreased glial growth over the scratch, suggesting participation of SRC, PI3K, and FAK in UTP-induced growth of glial cells in scratched cultures. RB-2 decreased dissociated glial cell attachment to fibronectin-coated dishes and migration through transwell membranes, suggesting that nucleotides regulated adhesion and migration of glial cells. In conclusion, mechanical scratch of retinal cell cultures induces growth of glial cells over the empty area through a mechanism that is dependent on activation of UTP-sensitive receptors, SRC, PI3K, and FAK.

  10. Comparison of two methods used to culture and purify rat retinal Müller cells.

    Science.gov (United States)

    Song, Wei-Tao; Zhang, Xue-Yong; Xiong, Si-Qi; Wen, Dan; Jiang, Jian; Xia, Xiao-Bo

    2013-01-01

    To study two methods for culturing and purifying Sprague-Dawley (SD) rat retinal Müller cells and determine which one is better. The passage culture method of Müller cells was respectively carried out by complete pancreatic enzyme digestion method and repeated incomplete pancreatic enzyme digestion method. After culturing retinal cells for one month through these two methods, fluorescence-activated cell sorter (FACS), RT-PCR, and immunohistochemistry technology were performed to examine the enrichment and purity of Müller glial cells, and carried out two-sample approximate t test using SSPS 13.0 to further compare the Müller cell positive rate in both methods. The statistical results showed that the purity of Müller cells was 83.2%±5.16% in group A, and the purity was 98.5%±1.08% in group B. The two-sample approximate t test analysis demonstrated that the difference between group A and group B was statistically significant (t=-9.178, Pcells cultured by the complete pancreatic enzyme digestion method (group A) and the repeated incomplete pancreatic enzyme digestion method (group B). Compared with the complete pancreatic enzyme digestion method, this novel method was more efficient and a higher purity of Müller cells could be obtained using this approach.

  11. Human Bone Marrow Stromal Cells can Differentiate to a Retinal Pigment Epithelial Phenotype when Co-Cultured with Pig Retinal Pigment Epithelium using a Transwell System

    Directory of Open Access Journals (Sweden)

    Ping Duan

    2013-05-01

    Full Text Available Background: There is an increasing interest in generating retinal pigment epithelial (RPE cells from stem cells for therapy against degenerative eye diseases. Human bone marrow stromal cells (hBMSCs can be induced to express retinal neuron-specific markers when co-cultured with retinal neurons, however, whether hBMSCs can differentiate into RPE-like cells in a co-culture system has not been clarified. Methods: The induction of hBMSCs into RPE-like cells was performed by combining hBMSCs and pig RPE cells in a transwell system. The biomarkers of hBMSCs-derived RPE cells were determined by quantitative RT-PCR and immunofluorescence. The function of induced cells was assayed by ELISA for secretion of neurotrophic factors. Results: Intracellular pigment granules and many RPE markers existed in hBMSCs-derived RPE cells after co-culturing with pig RPE cells for 14 days. Typical RPE functions, such as phagocytosis of photoreceptor outer segments and secretion of the trophic factors, brain-derived neurotrophic factor (BDNF and glia-derived neurotrophic factor (GDNF, were observed in these induced cells. Conclusion: hBMSCs can be induced toward functional RPE cells simply by transwell-based co-culture with RPE cells.

  12. Profound Re-Organization of Cell Surface Proteome in Equine Retinal Pigment Epithelial Cells in Response to In Vitro Culturing

    Directory of Open Access Journals (Sweden)

    Marius Ueffing

    2012-10-01

    Full Text Available The purpose of this study was to characterize the cell surface proteome of native compared to cultured equine retinal pigment epithelium (RPE cells. The RPE plays an essential role in visual function and represents the outer blood-retinal barrier. We are investigating immunopathomechanisms of equine recurrent uveitis, an autoimmune inflammatory disease in horses leading to breakdown of the outer blood-retinal barrier and influx of autoreactive T-cells into affected horses’ vitrei. Cell surface proteins of native and cultured RPE cells from eye-healthy horses were captured by biotinylation, analyzed by high resolution mass spectrometry coupled to liquid chromatography (LC MS/MS, and the most interesting candidates were validated by PCR, immunoblotting and immunocytochemistry. A total of 112 proteins were identified, of which 84% were cell surface membrane proteins. Twenty-three of these proteins were concurrently expressed by both cell states, 28 proteins exclusively by native RPE cells. Among the latter were two RPE markers with highly specialized RPE functions: cellular retinaldehyde-binding protein (CRALBP and retinal pigment epithelium-specific protein 65kDa (RPE65. Furthermore, 61 proteins were only expressed by cultured RPE cells and absent in native cells. As we believe that initiating events, leading to the breakdown of the outer blood-retinal barrier, take place at the cell surface of RPE cells as a particularly exposed barrier structure, this differential characterization of cell surface proteomes of native and cultured equine RPE cells is a prerequisite for future studies.

  13. Developmental cues for bone formation from parathyroid hormone and parathyroid hormone-related protein in an ex vivo organotypic culture system of embryonic chick femora.

    Science.gov (United States)

    Smith, Emma L; Kanczler, Janos M; Roberts, Carol A; Oreffo, Richard O C

    2012-12-01

    Enhancement and application of our understanding of skeletal developmental biology is critical to developing tissue engineering approaches to bone repair. We propose that use of the developing embryonic femur as a model to further understand skeletogenesis, and the effects of key differentiation agents, will aid our understanding of the developing bone niche and inform bone reparation. We have used a three-dimensional organotypic culture system of embryonic chick femora to investigate the effects of two key skeletal differentiation agents, parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP), on bone and cartilage development, using a combination of microcomputed tomography and histological analysis to assess tissue formation and structure, and cellular behavior. Stimulation of embryonic day 11 (E11) organotypic femur cultures with PTH and PTHrP initiated osteogenesis. Bone formation was enhanced, with increased collagen I and STRO-1 expression, and cartilage was reduced, with decreased chondrocyte proliferation, collagen II expression, and glycosaminoglycan levels. This study demonstrates the successful use of organotypic chick femur cultures as a model for bone development, evidenced by the ability of exogenous bioactive molecules to differentially modulate bone and cartilage formation. The organotypic model outlined provides a tool for analyzing key temporal stages of bone and cartilage development, providing a paradigm for translation of bone development to improve scaffolds and skeletal stem cell treatments for skeletal regenerative medicine.

  14. In vitro Culture of Bone Marrow Mesenchymal Stem Cells in Rats and Differentiation into Retinal Neural-like Cells

    Institute of Scientific and Technical Information of China (English)

    SUN Xufang; JIANG Huanrong; YANG Hong

    2007-01-01

    In order to study the in vitro culture and expansion of bone marrow mesenchymal stem cells in rats (rMSCs) and the possibility of rMSCs differentiation into retinal neural cells, the bone marrow-derived cells in SD rats were isolated and cultured in vitro. The retinal neural cells in SD rats were cultured and the supernatants were collected to prepare conditioned medium. The cultured rMSCs were induced to differentiate by two steps. Imrnunofluorescence method and anti-nestin, anti-NeuN, anti-GFAP and anti-Thy1.1 antibodies were used to identify the cells derived from the rMSCs. The results showed that the in vitro cultured rMSCs grew well and expanded quickly. After induction with two conditioned media, rMSCs was induced to differentiate into neural progenitor cells, then into retinal neural-like cells which were positive for nestin, NeuN, GFAP and Thy1.1 de-tected by fluorescence method. The findings suggested that rMSCs could be culture and expanded in vitro, and induced to differentiate into retinal neural-like cells.

  15. The Anti-Proliferative Effect of Inhibitor of Telomerase on Cultured Retinal Pigment Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to provide a new method for treating proliferative vitreoretinopathy (PVR), the effects of anti-proliferation and apoptosis induction of inhibitors of telomerase and heat shock protein 90 (Hsp90) on the cultured retinal pigment epithelial (RPE) cells were investigated. The rate of apoptosis cells was measured by using TUNEL on the cultured RPE cells, the co-cultured RPE cells with inhibitor of telomerase (camptothecin) or the co-cultured RPE cells with inhibitor of Hsp90 (geldanamycin). The cell proliferation status was measured in the above three groups by using MTT method. The rate of apoptosis in the RPE cells co-cultured with camptothecin or geldanamycin was increased remarkably (P<0.05). MTT showed the rate of growth inhibition was 8.4 %, 32.3 % and 72.3 % at the concentrations of camptothecin 1 μmol/L, 5 μmol/L, 10 μmol/L, respectively, and 6.5 %, 30.9 %, 71.9 % at the concentrations of geldanamycin 1 μmol/L, 5 μmol/L, 10 μmol/L, respectively. It was concluded that telomerase and Hsp90 can promote the proliferation of the cultured RPE cells, while the inhibitor of them can induce apoptosis and inhibit the growth of the RPE cells.

  16. Lack of FasL expression in cultured human retinal pigment epithelial cells

    DEFF Research Database (Denmark)

    Kaestel, C G; Madsen, H O; Prause, J U

    2001-01-01

    Retinal pigment epithelial (RPE) cells have been proposed to play a part in maintaining the eye as an immune privileged organ. However, our knowledge of the implicated mechanism is still sparse. Fas ligand (FasL) expression of RPE cells is generally recognized to be essential for the immune...... blotting, RT-PCR and RNase Protection assay for FasL expression. Additionally, sections of ocular tissue were stained for FasL by immunohistochemistry. None of the used methods indicated FasL expression in cultured fetal or adult RPE cells of various passages. However, RPE cells in vivo, as judged from...... tissue sections, were positive for FasL, indicating a discrepancy between RPE cells in vitro and in vivo with regard to this molecule....

  17. Culture of Adult Transgenic Zebrafish Retinal Explants for Live-cell Imaging by Multiphoton Microscopy.

    Science.gov (United States)

    Lahne, Manuela; Gorsuch, Ryne A; Nelson, Craig M; Hyde, David R

    2017-02-24

    An endogenous regeneration program is initiated by Müller glia in the adult zebrafish (Danio rerio) retina following neuronal damage and death. The Müller glia re-enter the cell cycle and produce neuronal progenitor cells that undergo subsequent rounds of cell divisions and differentiate into the lost neuronal cell types. Both Müller glia and neuronal progenitor cell nuclei replicate their DNA and undergo mitosis in distinct locations of the retina, i.e. they migrate between the basal Inner Nuclear Layer (INL) and the Outer Nuclear Layer (ONL), respectively, in a process described as Interkinetic Nuclear Migration (INM). INM has predominantly been studied in the developing retina. To examine the dynamics of INM in the adult regenerating zebrafish retina in detail, live-cell imaging of fluorescently-labeled Müller glia/neuronal progenitor cells is required. Here, we provide the conditions to isolate and culture dorsal retinas from Tg[gfap:nGFP](mi2004) zebrafish that were exposed to constant intense light for 35 h. We also show that these retinal cultures are viable to perform live-cell imaging experiments, continuously acquiring z-stack images throughout the thickness of the retinal explant for up to 8 h using multiphoton microscopy to monitor the migratory behavior of gfap:nGFP-positive cells. In addition, we describe the details to perform post-imaging analysis to determine the velocity of apical and basal INM. To summarize, we established conditions to study the dynamics of INM in an adult model of neuronal regeneration. This will advance our understanding of this crucial cellular process and allow us to determine the mechanisms that control INM.

  18. Primary Adult Human Retinal Pigment Epithelial Cell Cultures on Human Amniotic Membranes

    Directory of Open Access Journals (Sweden)

    Singhal Shweta

    2005-01-01

    Full Text Available Purpose: Retinal pigment epithelial (RPE cells grow well on surfaces that provide an extracellular matrix. Our aim was to establish primary adult human RPE cell cultures that retain their epithelial morphology in vitro using human amniotic membrane (hAM as substrate. Materials and Methods: Human cadaver eyeballs (16 were obtained from the eye bank after corneal trephination. RPE cells were harvested by a mechanical dissection of the inner choroid surface (10, group 1 or by b enzymatic digestion using 0.25% Trypsin/0.02% EDTA (6, group 2. The cells were explanted onto de-epithelialized hAM, nourished using DMEM/HAMS F-12 media and monitored for growth under the phase contrast microscope. Cell cultures were characterised by whole mount studies and paraffin sections. Growth data in the two groups were compared using the students′ ′t′ test. Results: Eleven samples (68.75% showed positive cultures with small, hexagonal cells arising from around the explant which formed a confluent and progressively pigmented monolayer. Whole mounts showed closely placed polygonal cells with heavily pigmented cytoplasm and indistinct nuclei. The histologic sections showed monolayers of cuboidal epithelium with variable pigmentation within the cytoplasm. Growth was seen by day 6-23 (average 11.5 days in the mechanical group, significantly earlier ( P Conclusions: Primary adult human RPE cell cultures retain epithelial morphology in vitro when cultured on human amniotic membranes . Mechanical dissection of the inner choroid surface appears to be an effective method of isolating RPE cells and yields earlier growth in cultures as compared to isolation by enzymatic digestion

  19. Effect of Hypericin on Confocal Imaging of Ca2+ Signaling in Cultured Human Retinal Pigment Epithelium

    Institute of Scientific and Technical Information of China (English)

    Qianying Gao; Yannian Hui; Yusheng Wang; Lin Wang

    2001-01-01

    Purpose: To investigate the mechanism of the Ca2 + signaling in cultured human retinal pigment epithelial(RPE) cells with the protein kinase C(PKC) specific inhibitor-hypericin stimulation.Methods: Cultured human RPE cells were analyzed using the fluorescence Ca2+ dye fluo-3 AM and laser scanning confocal microscope(LSCM) after stimulation with 100nM phorbol 12-myristate 13-acetate(PMA) and (or)5 concentrations of hypericin(1, 2, 3, 4 and 5 μM).Results: The normal fluorescence in RPE cells was strong and distributed throughout the cells. The nucleus appeared to be more fluorescent than the cytoplasm. After stimulation with PMA alone or 5 concentrations of hypericin, a rapid decrease in flurescence intensity was observed. There was no obvious difference in decreased curve among 5concentrations. However, after stimulation with a 24 hr preincubation of PMA and 5 concentrations of hypericin, a further decrease was not observed.Conclusion: Fluo-3 AM appears to be a good indicator of the change in Ca2+ occurring in RPE cells and hypericin is a strong inhibitor of Ca2 + influx channel. Hypericin has potential as a therapeutic drug for proliferative vitreoretinopathy(PVR), the inhibitory effect on PVR might be caused by blocking the PKC activity and inhibiting Ca2+ influxpathway.

  20. Change of morphological and functional characteristics of retinal pigment epithelium cells during cultivation of retinal pigment epithelium-choroid perfusion tissue culture.

    Science.gov (United States)

    Miura, Yoko; Klettner, Alexa; Noelle, Bernhard; Hasselbach, Heike; Roider, Johann

    2010-01-01

    To evaluate the changes of morphological and functional characteristics of the retinal pigment epithelium (RPE)-choroid perfusion culture during cultivation. PorcineRPE-choroid tissue was cultivated in a perfusion tissue culture system. After the indicated times, histology, immunolocalization of collagen IV and von Willebrand factor, RPE cell viability with calcein-AM, TUNEL assay and occludin immunolocalization of RPE cells were examined. The tissue was treated with selective RPE treatment laser after different time periods and the wound healing response was characterized. Vascular endothelial growth factor secretion was measured by enzyme-linked immunosorbent assay. On day 8, prominent morphological degenerative changes of RPE cells were observed in histology. According to the immunohistochemistry for collagen IV, the Bruch's membrane did not display any obvious decomposition until day 8. Von Willebrand factor staining decreased during cultivation, especially at the choriocapillaris. Calcein-AM staining and TUNEL assay displayed the increase of apoptotic changes in only a minority of the cells on day 4, but in many cells on day 8. Occludin delocalization was observed on day 8. Selective RPE treatment laser-produced wounds were completely closed by monolayer RPE when wounded on fresh and 3-day-old cultures, but not when wounded on 6-day-old cultures. Vascular endothelial growth factor secretion was stable between days 2 and 5, but increased after that. Under the stated culture perfusion conditions, porcine RPE-choroid tissue was suitable for experimentation up to 5 days of maintenance. Copyright 2009 S. Karger AG, Basel.

  1. Retinal pigment epithelial cells upregulate expression of complement factors after co-culture with activated T cells

    DEFF Research Database (Denmark)

    Juel, Helene Bæk; Kaestel, Charlotte; Folkersen, Lasse

    2011-01-01

    In this study we examined the effect of T cell-derived cytokines on retinal pigment epithelial (RPE) cells with respect to expression of complement components. We used an in vitro co-culture system in which CD3/CD28-activated human T cells were separated from the human RPE cell line (ARPE-19) by ...... of inflammatory ocular diseases such as uveitis and age-related macular degeneration. --------------------------------------------------------------------------------...

  2. Transport of protons and lactate in cultured human fetal retinal pigment epithelial cells

    DEFF Research Database (Denmark)

    Hamann, Steffen; Cour, Morten la; Ming Lui, Ge

    2000-01-01

    Electron microscopy, intracellular pH, monocarboxylate transport, pigment epithelium of eye, proton-lactate cotransport, retinal metabolism, sodium/proton exchange......Electron microscopy, intracellular pH, monocarboxylate transport, pigment epithelium of eye, proton-lactate cotransport, retinal metabolism, sodium/proton exchange...

  3. Biological effects of cigarette smoke in cultured human retinal pigment epithelial cells.

    Directory of Open Access Journals (Sweden)

    Alice L Yu

    Full Text Available The goal of the present study was to determine whether treatment with cigarette smoke extract (CSE induces cell loss, cellular senescence, and extracellular matrix (ECM synthesis in primary human retinal pigment epithelial (RPE cells. Primary cultured human RPE cells were exposed to 2, 4, 8, and 12% of CSE concentration for 24 hours. Cell loss was detected by cell viability assay. Lipid peroxidation was assessed by loss of cis-parinaric acid (PNA fluorescence. Senescence-associated ß-galactosidase (SA-ß-Gal activity was detected by histochemical staining. Expression of apolipoprotein J (Apo J, connective tissue growth factor (CTGF, fibronectin, and laminin were examined by real-time PCR, western blot, or ELISA experiments. The results showed that exposure of cells to 12% of CSE concentration induced cell death, while treatment of cells with 2, 4, and 8% CSE increased lipid peroxidation. Exposure to 8% of CSE markedly increased the number of SA-ß-Gal positive cells to up to 82%, and the mRNA expression of Apo J, CTGF, and fibronectin by approximately 3-4 fold. Treatment with 8% of CSE also increased the protein expression of Apo J and CTGF and the secretion of fibronectin and laminin. Thus, treatment with CSE can induce cell loss, senescent changes, and ECM synthesis in primary human RPE cells. It may be speculated that cigarette smoke could be involved in cellular events in RPE cells as seen in age-related macular degeneration.

  4. Assessment of developmental cardiotoxic effects of some commonly used phytochemicals in mouse embryonic D3 stem cell differentiation and chick embryonic cardiomyocyte micromass culture models.

    Science.gov (United States)

    Mohammed, Omar J; McAlpine, Roseanna; Chiewhatpong, Phasawee; Latif, Muhammad Liaque; Pratten, Margaret K

    2016-09-01

    Pregnant women often use herbal medicines to alleviate symptoms of pregnancy. The active phytochemicals eugenol (from holy basil) and α-bisabolol (from chamomile) are recommended to promote calmness and reduce stress. There is evidence that both eugenol and α-bisabolol possess pro-apoptotic and anti-proliferative effects and induce reactive oxygen species. The potential effect was examined by monitoring cardiomyocyte contractile activity (differentiation), cell activity, protein content and ROS production for mouse D3 embryonic stem cell and ‎chick embryonic micromass culture. The results showed that eugenol (0.01-80μM) demonstrated effects on cell activity (both systems) and ROS production (stem cell system only), as well as decreasing the contractile activity and protein content at high concentrations in both systems. Additionally, α-bisabolol (0.01-80μM) at high concentrations decreased the contractile activity and cell activity and in the stem cell system induced ROS production and decreased protein content. The results suggest only low concentrations should be ingested in pregnancy.‎.

  5. Chick heart invasion assay.

    Science.gov (United States)

    Bracke, Marc E; Parmar, Virinder S; Depass, Anthony L; Stevens, Christian V; Vanhoecke, Barbara W; Mareel, Marc M

    2014-01-01

    Tumors are microecosystems in which a continuous cross talk between cancer cells and host cells decides on the invasive behavior of the tumor cell population as a whole (Mareel et al., Encyclopedia of cancer, San Diego, CA, Academic Press, 1997). Both compartments secrete activating and inhibitory factors that modulate activities such as cell-extracellular matrix (ECM) interaction, cell-cell adhesion, remodeling of the ECM, and cell motility. For this reason, confrontations of cancer cells with a living normal host tissue in organ culture have been introduced by several groups: Wolff and Schneider in France (Wolff and Schneider, C R S Soc Biol (Paris) 151:1291-1292, 1957), Easty and Easty in the United Kingdom (Easty and Easty, Nature 199:1104-1105, 1963), and Schleich in Germany (Schleich et al., J Natl Cancer Inst 56:221-237, 1976). Embryonic chick heart fragments in organ culture maintain many histological features of their tissue of origin: They are composed of myocytes, fibroblasts, and endothelial cells, and their ECM contains fibronectin, laminin, and several collagen types. Moreover, the fragments remain contractile, and this activity allows the monitoring of their functional integrity during organ culture.

  6. Differential potency of atropisomers of polychlorinated biphenyls on cytochrome P450 induction and uroporphyrin accumulation in the chick embryo hepatocyte culture.

    Science.gov (United States)

    Rodman, L E; Shedlofsky, S I; Mannschreck, A; Püttmann, M; Swim, A T; Robertson, L W

    The atropisomers of 2,2',3,4,6-pentachlorobiphenyl (PeCB), 2,2',3,4,4',6-hexachlorobiphenyl (HeCB), and 2,2',3,3',4,4',6,6'-octachlorobiphenyl (OCB) were studied in the chick embryo hepatocyte culture to determine if chirality plays a role in the recognition events associated with the induction of cytochromes P450 and the accumulation of uroporphyrin (URO). Concentration-related induction of cytochrome P450 content, ethoxyresorufin-O-deethylase (EROD) and benzphetamine N-demethylase (BPDM) activities were measured. The rank order of potency for total cytochrome P450 induction was HeCB greater than OCB greater than or equal to PeCB. The (+)- and (-)-enantiomers of PeCB and OCB were of equal potencies as inducers of cytochromes P450, whereas the (+)-HeCB was greater than the (-)-HeCB. HeCB was a much more potent inducer of EROD activity than was either PeCB or OCB. EROD activity was induced to a much greater extent by the (+)-enantiomers of all compounds, with the (-)-enantiomers of PeCB and OCB being inactive. BPDM activity was induced by all three compounds in the order of OCB greater than or equal to HeCB greater than PeCB. The (-)-enantiomers were more potent inducers of BPDM activities than were the (+)-enantiomers, except for HeCB, in which the (+)- was more potent than the (-)-enantiomer. Analysis of porphyrin accumulation in cultures treated with delta-aminolevulinic acid revealed that (+)-HeCB caused the greatest percent URO accumulation, which also correlated with the greatest increase in EROD activity. All other enantiomers caused up to 47% URO accumulation, which did not correlate with an increase in EROD activity.

  7. L-type calcium channels may regulate neurite initiation in cultured chick embryo brain neurons and N1E-115 neuroblastoma cells.

    Science.gov (United States)

    Audesirk, G; Audesirk, T; Ferguson, C; Lomme, M; Shugarts, D; Rosack, J; Caracciolo, P; Gisi, T; Nichols, P

    1990-08-01

    The intracellular free Ca2+ concentration, [Ca2+]i, plays an important role in regulating neurite growth in cultured neurons. Insofar as [Ca2+]i is partly a function of Ca2+ influx through voltage-sensitive calcium channels (VSCC), Ca2+ entry through VSCC should influence neurite growth. Vertebrate neurons may possess several types of VSCC. The most frequently described VSCC types are usually designated L, T and N. In most preparations, these VSCC types respond differently to certain pharmacological agents, including Cd2+, Ni2+, the dihydropyridines nifedipine and BAY K8644, and the aminoglycoside antibiotics. We used these agents to study the role of Ca2+ influx in regulating neurite initiation and length in cultures of chick embryo brain neurons and N1E-115 mouse neuroblastoma cells. In chick neurons, nifedipine and Cd2+ (less than 50 microM), which have been reported to inhibit L-type channels, reduced neurite initiation, but not mean neurite length. Ni2+ (less than 100 microM), reported to inhibit T-type channels, had no effect on either initiation or length. Low concentrations of most aminoglycosides (less than 300 microM), reported to inhibit N-type channels, had no effect on neurite initiation, but high concentrations of streptomycin (great than 300 microM), reported to inhibit both L- and N-type channels, reduced neurite initiation. BAY K8644, which enhances current flow through L-type channels, had no effect except at high concentration (50 microM), which inhibited initiation. N1E-115 neuroblastoma cells have been reported to contain L-type and T-type channels, but thus far no channel similar to the N-type has been described. In cultured N1E-115 cells, nifedipine (5 microM), Cd2+ (5 microM), and streptomycin (200 microM) reduced neurite initiation, while nickel (50 microM) and neomycin (100 microM) did not affect initiation. None of these agents altered neurite length. In N1E-115 cells, whole-cell voltage clamp recordings showed that nifedipine and Cd2

  8. Development of Experimental Myopia in Chicks in a Natural Environment

    Science.gov (United States)

    Stone, Richard A.; Cohen, Yuval; McGlinn, Alice M.; Davison, Sherrill; Casavant, Susan; Shaffer, James; Khurana, Tejvir S.; Pardue, Machelle T.; Iuvone, P. Michael

    2016-01-01

    Purpose The hypothesis that outdoor exposure might protect against myopia has generated much interest, although available data find only modest clinical efficacy. We tested the effect of outdoor rearing on form-deprivation myopia in chicks, a myopia model markedly inhibited by high-intensity indoor laboratory lighting. Methods Unilaterally goggled cohorts of White Leghorn chicks were maintained in a species-appropriate, outdoor rural setting during daylight hours to the extent permitted by weather. Control chicks were reared indoors with incandescent lighting. Besides ocular refraction and ultrasound, we determined dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) content in retina and vitreous and measured mRNA expression levels of selected clock and circadian rhythm-related genes in the retina/RPE. Results Myopia developed in the goggled eyes of all cohorts. Whereas outdoor rearing lessened myopia by 44% at 4 days, a protective effect was no longer evident at 11 days. Outdoor rearing had no consistent effect on retinal or vitreous content of dopamine or DOPAC. Conforming to prior data on form-deprivation myopia, retina and vitreous levels of DOPAC were reduced in goggled eyes. Compared with contralateral eyes, the retinal expression of clock and circadian rhythm-related genes was modestly altered in myopic eyes of chicks reared indoors or outdoors. Conclusions Outdoor rearing of chicks induces only a partial decrease of goggle-induced myopia that is not maintained, without evidence that retinal dopamine metabolism accounts for the partial myopia inhibition under these outdoor conditions. Although modest, alterations in retinal gene expression suggest that studying circadian signals might be informative for understanding refractive mechanisms. PMID:27618415

  9. Efficacy of early chick nutrition with Aloe vera and Azadirachta indica on gut health and histomorphometry in chicks

    Science.gov (United States)

    Sujatha, Tamilvanan; Abhinaya, Sivasankar; Sunder, Jai; Thangapandian, Marudhai; Kundu, Anandamoy

    2017-01-01

    Aim: This study was conducted with an aim of studying the efficacy of water supplements of Aloe vera and Azadirachta indica (neem) during pre-starter age (0-2 weeks) on gut health and histomorphometry in Vanaraja chicks. Materials and Methods: A total of 192 day old Vanaraja chicks were randomly assigned to one of four herbal water treatments throughout the experimental pre-starter stage (0-2 weeks) in a completely randomized design. Each treatment was given four replicates consisting of 12 chicks per replicate. Water treatments comprised T1: Control with regular antibiotic supplement, T2: 3 ml Aloe juice per chick per day, T3: 3 ml neem extract per chick per day, T4: 1.5 ml Aloe and 1.5 ml neem per chick per day. Gut culture was done for Escherichia coli and Lactobacillus sps. and gut histomorphometry in 24 gut samples at 14 days of age. Results: This study revealed that supplementation of A. vera and neem in water significantly (pneem supplementation as compared to that of control chicks. Significantly lower crypt depth (pneem and Aloe supplementation in chicks as compared to their combination and control. Conclusion: Immediate post hatch supplementation of Aloe juice and neem extract in chicks improved the development and health of their gut. PMID:28717305

  10. Glucose and TGF β2 Modulate the Viability of Cultured Human Retinal Pericytes and Their VEGF Release

    Science.gov (United States)

    Vidro, Eileen K.; Gee, Stephen; Unda, Richard; Ma, Jian-xing; Tsin, Andrew

    2015-01-01

    Purpose Determine the effects of glucose and exogenous TGFβ2 on viability and VEGF release by human retinal pericytes (HRP). Methods Human retinal pericytes (HRP) were cultured in 5 mM (physiologic) or high (18 mM) glucose with or without added TGFβ2. Viable cells were counted; TGFβ2 and VEGF in the conditioned media (CM) were measured by ELISA. Results High glucose significantly reduced viable cell number and increased the levels of TGFβ2 and VEGF. TGFβ2 caused a significant dose-dependent effect on viable cell number and on the level of VEGF secreted into the CM by HRP in physiologic glucose, decreasing viable cell number, and increasing VEGF release per 1000 cells at a low concentration (0.1 ng/ml) and increasing viable cell number and decreasing VEGF release per 1000 cells at higher concentrations (1.0 and 10 ng/ml). TGFβ2 affected neither parameter in high glucose. Conclusions Elevated glucose decreased HRP viability and modulated changes in TGFβ2 and VEGF release. This suggests a novel mechanism for HRP dropout in diabetic retinopathy. PMID:19085381

  11. Partial mitochondrial complex I inhibition induces oxidative damage and perturbs glutamate transport in primary retinal cultures. Relevance to Leber Hereditary Optic Neuropathy (LHON).

    Science.gov (United States)

    Beretta, Simone; Wood, John P M; Derham, Barry; Sala, Gessica; Tremolizzo, Lucio; Ferrarese, Carlo; Osborne, Neville N

    2006-11-01

    Leber Hereditary Optic Neuropathy (LHON) is a maternally inherited form of visual loss, due to selective degeneration of retinal ganglion cells. Despite the established aetiological association between LHON and mitochondrial DNA mutations affecting complex I of the electron transport chain, the pathophysiology of this disorder remains obscure. Primary rat retinal cultures were exposed to increasing concentrations of rotenone to titrate complex I inhibition. Neural cells were more sensitive than Müller glial cells to rotenone toxicity. Rotenone induced an increase in mitochondrial-derived free radicals and lipid peroxidation. Sodium-dependent glutamate uptake, which is mostly mediated by the glutamate transporter GLAST expressed by Müller glial cells, was reduced dose-dependently by rotenone with no changes in GLAST expression. Our findings suggest that complex I-derived free radicals and disruption of glutamate transport might represent key elements for explaining the selective retinal ganglion cell death in LHON.

  12. Effects of Nerve Growth Factor on Proliferation and DNA Synthesis of Cultured Human Fetal Retinal Pigment Epithelium Cells

    Institute of Scientific and Technical Information of China (English)

    Wensheng Li; Jun Wen; Deyong Jiang; Jianguang Ding

    2002-01-01

    Objective: To investigate the effects of nerve growth factor(NGF)on proliferation and DNAthesis of cultured human fetal retinal pigment epithelium (RPE)cells in vitro.Methods: Primary culture and subculture of human fetal retinal pigment epithelium cellswere established in vitro first. Cultured RPE cells were treated with NGF by variousconcentrations 0μg/L, 50μg/L, 100μg/L, 200μg/L and 300μg/L(final concentration)for 48 hs.After 48 hs, cells proliferation was measured with methyl thiazolyl tetrazolium(MTT)assay method and the amount of DNA was determined by the absorbance at 280nm of nucleic acid & protein analysis.Results: The A values of 100 μg/L, 200 μg/L, 300 μg/L NGF was(0. 213 7 ± 0. 23 3),(0. 218 8 ±0. 018 1), (0. 232 2 ±0. 016 4) as compared with(0. 189 7 ±0. 015 2) of Avalue of 0 μg/L NGF respectively, q value was 3.63,4.40, 6. 42 and P value was0. 015, 0. 000, 0. 000(q-test). The DNA concentrations of 100 μg/L, 200 μg/L, 300μg/L and 400 μg/L NGF was (981. 220 4 ± 123.535 7), (1 375. 848 4 ±244. 471 8),(1 658.707 1 ± 176. 938 1), (2 353.086 3 ±609. 906 4) μg/ml as compared with(666. 818 8 ± 141. 330 2) μg/ml of DNA concentration of 0 μg/L NGF respectively, qvalue was 3.63,8.20,11.47,19.46, P value was 0. 024,0. 000,0. 000,0. 000 (q-test).Conclusion: The data suggested that NGF could stimulate the proliferation and DNAsynthesis of cultured of hRPE cells in vitro in a dose-dependent manner.

  13. Vitreous humor and albumin augment the proliferation of cultured retinal precursor cells

    DEFF Research Database (Denmark)

    Yang, Jing; Klassen, Henry; Pries, Mette

    2008-01-01

    Intravitreal injection is an important delivery route for studies involving the transplantation of various types of precursor cells to the retina; however, the effect on these cells of exposure to the vitreous microenvironment has not been specifically investigated. Here vitreous humor was evalua......Intravitreal injection is an important delivery route for studies involving the transplantation of various types of precursor cells to the retina; however, the effect on these cells of exposure to the vitreous microenvironment has not been specifically investigated. Here vitreous humor...... was evaluated for the potential to influence the proliferation of rat retinal precursor cells in vitro. Cells were isolated at embryonic day 19 and plated in standard proliferation medium in the presence or absence of fluid expressed from porcine vitreous humor. Cellular proliferation at different...

  14. Characterization of Three-Dimensional Retinal Tissue Derived from Human Embryonic Stem Cells in Adherent Monolayer Cultures

    Science.gov (United States)

    Singh, Ratnesh K.; Mallela, Ramya K.; Cornuet, Pamela K.; Reifler, Aaron N.; Chervenak, Andrew P.; West, Michael D.; Wong, Kwoon Y.; Nasonkin, Igor O.

    2015-01-01

    Stem cell-based therapy of retinal degenerative conditions is a promising modality to treat blindness, but requires new strategies to improve the number of functionally integrating cells. Grafting semidifferentiated retinal tissue rather than progenitors allows preservation of tissue structure and connectivity in retinal grafts, mandatory for vision restoration. Using human embryonic stem cells (hESCs), we derived retinal tissue growing in adherent conditions consisting of conjoined neural retina and retinal pigment epithelial (RPE) cells and evaluated cell fate determination and maturation in this tissue. We found that deriving such tissue in adherent conditions robustly induces all eye field genes (RX, PAX6, LHX2, SIX3, SIX6) and produces four layers of pure populations of retinal cells: RPE (expressing NHERF1, EZRIN, RPE65, DCT, TYR, TYRP, MITF, PMEL), early photoreceptors (PRs) (coexpressing CRX and RCVRN), inner nuclear layer neurons (expressing CALB2), and retinal ganglion cells [RGCs, expressing BRN3B and Neurofilament (NF) 200]. Furthermore, we found that retinal progenitors divide at the apical side of the hESC-derived retinal tissue (next to the RPE layer) and then migrate toward the basal side, similar to that found during embryonic retinogenesis. We detected synaptogenesis in hESC-derived retinal tissue, and found neurons containing many synaptophysin-positive boutons within the RGC and PR layers. We also observed long NF200-positive axons projected by RGCs toward the apical side. Whole-cell recordings demonstrated that putative amacrine and/or ganglion cells exhibited electrophysiological responses reminiscent of those in normal retinal neurons. These responses included voltage-gated Na+ and K+ currents, depolarization-induced spiking, and responses to neurotransmitter receptor agonists. Differentiation in adherent conditions allows generation of long and flexible pieces of 3D retinal tissue suitable for isolating transplantable slices of tissue for

  15. Effect of retinoic acid on proliferation and polyamine metabolism in cultured bovine retinal pigment epithelial cells.

    Science.gov (United States)

    Yasunari, T; Yanagihara, N; Komatsu, T; Moriwaki, M; Shiraki, K; Miki, T; Yano, Y; Otani, S

    1999-01-01

    Reports regarding the effect of all-trans-retinoic acid (RA) on the cell growth of retinal pigment epithelial cells (RPE) have been contradictory. The aims of this study are to clarify the in vitro effect of RA on RPE cells and to examine polyamine metabolism after RA stimulation. A 4-day incubation of fetal-calf-serum (FCS)-stimulated RPE cells with 10 or 25 microM RA significantly increased both cell number and [3H]thymidine incorporation. RPE cells grown over an extended period for 8 days also increased in number and reached full confluency. However, if the incubation was further extended to 12 days, no further increase in cell number was detected. RA treatment of FCS-stimulated RPE cells shifted the peak of ornithine decarboxylase (ODC) activity from 16 to 4 h. S-adenosylmethionine decarboxylase (SAMDC) activity and spermidine/spermine N1-acetyltransferase (SAT) activity of RA-treated RPE cells were significantly greater until 8 and 16 h after incubation, respectively. The putrescine content was significantly increased in RA-treated RPE cells up until 24 h, while spermidine, spermine and N1-acetylspermidine contents were significantly increased until 16 h. Our findings suggest that RA treatment increases the intracellular polyamine concentration of RPE cells via activation of ODC, SAMDC and SAT and that this results in the promotion of RPE cell growth until the cells reach full confluency.

  16. Locational heterogeneity of maturation by changes in migratory behaviors of human retinal pigment epithelial cells in culture.

    Science.gov (United States)

    Sonoi, Rie; Kim, Mee-Hae; Kino-oka, Masahiro

    2015-01-01

    To better characterize human retinal pigment epithelial (RPE) cells, their maturation was studied by time-lapse observation and immunostaining of the tight junction protein ZO-1. During subconfluency with active migration, the cells had an elongated shape. During cell division to reach confluency, RPE cells became small and tight, exhibiting cobblestone-like morphology. In addition, RPE maturation at the peripheral region of the culture vessel was delayed when compared with the central region, demonstrating local heterogeneity during maturation. To correlate cellular migration and maturation, we compared frequencies of migration rate and number of ZO-1-positive cells at the central and peripheral regions. Cells having migration rates less than 5.0 μm/h in the central region were 1.4-fold higher than in the peripheral region at day 5. Regardless of locational differences in the culture vessel, the frequency of cells having migration rates less than 5.0 μm/h showed 90% agreement with the frequency of ZO-1-positive cells. To inhibit cell migration, RPE cells were exposed to medium containing 50 μg/ml Rac1 inhibitor at day 5. Frequencies of ZO-1-positive cells and cells having migration rates less than 5.0 μm/h at the peripheral region were similar to those at the central region. The results show that migration is an important factor affecting maturation, and demonstrate that location heterogeneity during maturation is caused by different migratory behaviors in the culture vessel. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. Cell volume regulation in cultured human retinal Muller cells is associated with changes in transmembrane potential.

    Directory of Open Access Journals (Sweden)

    Juan M Fernández

    Full Text Available Müller cells are mainly involved in controlling extracellular homeostasis in the retina, where intense neural activity alters ion concentrations and osmotic gradients, thus favoring cell swelling. This increase in cell volume is followed by a regulatory volume decrease response (RVD, which is known to be partially mediated by the activation of K(+ and anion channels. However, the precise mechanisms underlying osmotic swelling and subsequent cell volume regulation in Müller cells have been evaluated by only a few studies. Although the activation of ion channels during the RVD response may alter transmembrane potential (Vm, no studies have actually addressed this issue in Müller cells. The aim of the present work is to evaluate RVD using a retinal Müller cell line (MIO-M1 under different extracellular ionic conditions, and to study a possible association between RVD and changes in Vm. Cell volume and Vm changes were evaluated using fluorescent probe techniques and a mathematical model. Results show that cell swelling and subsequent RVD were accompanied by Vm depolarization followed by repolarization. This response depended on the composition of extracellular media. Cells exposed to a hypoosmotic solution with reduced ionic strength underwent maximum RVD and had a larger repolarization. Both of these responses were reduced by K(+ or Cl(- channel blockers. In contrast, cells facing a hypoosmotic solution with the same ionic strength as the isoosmotic solution showed a lower RVD and a smaller repolarization and were not affected by blockers. Together, experimental and simulated data led us to propose that the efficiency of the RVD process in Müller glia depends not only on the activation of ion channels, but is also strongly modulated by concurrent changes in the membrane potential. The relationship between ionic fluxes, changes in ion permeabilities and ion concentrations -all leading to changes in Vm- define the success of RVD.

  18. Use of pHluorin to assess the dynamics of axon guidance receptors in cell culture and in the chick embryo.

    Science.gov (United States)

    Delloye-Bourgeois, Céline; Jacquier, Arnaud; Falk, Julien; Castellani, Valérie

    2014-01-12

    During development, axon guidance receptors play a crucial role in regulating axons sensitivity to both attractive and repulsive cues. Indeed, activation of the guidance receptors is the first step of the signaling mechanisms allowing axon tips, the growth cones, to respond to the ligands. As such, the modulation of their availability at the cell surface is one of the mechanisms that participate in setting the growth cone sensitivity. We describe here a method to precisely visualize the spatio-temporal cell surface dynamics of an axon guidance receptor both in vitro and in vivo in the developing chick spinal cord. We took advantage of the pH-dependent fluorescence property of a green fluorescent protein (GFP) variant to specifically detect the fraction of the axon guidance receptor that is addressed to the plasma membrane. We first describe the in vitro validation of such pH-dependent constructs and we further detail their use in vivo, in the chick spinal chord, to assess the spatio-temporal dynamics of the axon guidance receptor of interest.

  19. Chick lit, chick magnet, biker chick, hippie chick: metaphorical uses of chick in contemporary american english = Chick lit, chick magnet, biker chick, hippie chick: usos metafóricos de chick no inglês americano contemporâneo

    Directory of Open Access Journals (Sweden)

    Mottin, Lívia Pretto

    2011-01-01

    Full Text Available Metáforas não são apenas uma ferramenta poética ou retórica, mas fazem parte do nosso sistema conceptual (Lakoff and Johnson, 1980 e nos permitem entender determinado aspecto de um conceito em termos de outro. Este artigo tem o objetivo de desvendar como o lexema chick pode ser usado para referir ao universo feminino. Primeiramente, apresento uma revisão bibliográfica sobre metáforas e, então, verifico como o domínio de animais pode ser usado para melhor explicar o comportamento humano. Em seguida, apresento dados coletados no Corpus of Contemporary American English (COCA para identificar e interpretar algumas metáforas de chick através de uma análise baseada em corpus. Em cada subcorpus do COCA, as primeiras 100 linhas de concordâncias aleatórias foram analisadas em contexto a fim de verificar as ocorrências dos usos metafóricos e dos usos literais da palavra de busca. As ocorrências não literais foram examinadas com maior cuidado com o objetivo de verificar o uso metafórico por elas representado, determinar a posição que o lexema pode ocupar em uma frase e verificar que palavras são fortes colocadas de chick. Os resultados mostram que chick é uma metáfora produtiva, usada tanto como substantivo quanto como adjetivo. Além disso, as ocorrências de chick em seu sentido metafórico excedem suas ocorrências em sentido literal

  20. Aqueous humor enhances the proliferation of rat retinal precursor cells in culture, and this effect is partially reproduced by ascorbic acid

    DEFF Research Database (Denmark)

    Yang, Jing; Klassen, Henry; Pries, Mette

    2006-01-01

    Aqueous humor has been shown to influence the proliferation of various ocular cell types, but the effect on immature retinal cells is not known. Here, the effect of pig aqueous humor on the proliferation of rat retinal precursor cells (RPCs) was investigated. RPCs were prepared from embryonic day...... 19 Sprague-Dawley rats and cultured in the presence or absence of aqueous humor from healthy pigs along with a medium consisting of Dulbecco's modified Eagle's medium:Ham's F-12 medium, N2 supplement, and epidermal growth factor. Proliferation was quantified by [(3)H]thymidine incorporation under...... different treatment conditions, and any associated morphological changes were noted. Potential active components of porcine aqueous humor were partially characterized by gel filtration chromatography, and the effect on RPC proliferation was determined. Results showed that adding 20% aqueous humor increased...

  1. Induction of Heat Shock Protein-72 by Magnetic Nanofluid Hyperthermia in Cultured Retinal Ganglion Cells for Neuroprotective Treatment in Glaucoma

    Directory of Open Access Journals (Sweden)

    Jin Wook Jeoung

    2015-01-01

    Full Text Available Background. Magnetic hyperthermia using superparamagnetic nanoparticle (SPNP agents is considered a promising biotechnological approach to induce heat shock proteins (HSPs in a target tissue because it can generate accurately controllable localized heating. Objectives. The main objective of this study is to demonstrate induction of HSPs in cultured retinal ganglion cells (RGCs by using engineered Mn0.5Zn0.5Fe2O4 SPNP agents coated with polyethylene glycol (PEG 500. Methods. The Mn0.5Zn0.5Fe2O4 nanoparticles were synthesized using a high temperature thermal decomposition method. The AC heating characteristics of PEG 500-coated Mn0.5Zn0.5Fe2O4 nanoparticles were investigated using an AC solenoid coil-capacitor system. Results. PEG 500-coated SPNPs efficiently penetrated into the cytoplasm of RGCs without causing obvious cytological changes and showed stable and well-saturated self-heating temperature rise characteristics. Immunofluorescent staining images showed that AC magnetic hyperthermia successfully induced HSP72 in RGCs incubated with Mn0.5Zn0.5Fe2O4 nanoparticles. In Western blot analysis, a significant increase in immunoreactivity was observed for RGCs incubated with SPNPs in a fixed AC magnetic field (fappl=140 kHz and Happl=140 Oe. Conclusion. Our results demonstrate that the induction of HSP72 with a magnetic nanofluid hyperthermia could potentially be used as a neuroprotective treatment modality by way of enhancing a natural cytoprotective response.

  2. Study of the infectivity of saline-stored Campylobacter jejuni for day-old chicks

    DEFF Research Database (Denmark)

    Hald, Birthe; Knudsen, Katrine; Lind, Peter

    2001-01-01

    The culturability of three Campylobacter jejuni strains and their infectivity for day-old chicks were assessed following storage of the strains in saline. The potential for colonization of chicks was weakened during the storage period and terminated 3 to 1 weeks before the strains became...

  3. Influences of Feeding Lactobacillus on Colonization of the Lactobacillus in Chicks'Digestible Tracts

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    It was carried out with culture solution of Lactobacillus fed to the newborn chicks to observe the influences on colonization of the Lactobacillus in chicks′ digestible tracts. The results showed that after the chicks were fed Lactobacillus, the amount of the Lactobacillus in chicks′ digestible tracts significantly increased (P<0.01) and the Lactobacillus colonized 36h ahead of schedule

  4. Retinal Vasculitis

    Science.gov (United States)

    Rosenbaum, James T.; Sibley, Cailin H.; Lin, Phoebe

    2016-01-01

    Purpose of review Ophthalmologists and rheumatologists frequently miscommunicate in consulting on patients with retinal vasculitis. This report seeks to establish a common understanding of the term, retinal vasculitis, and to review recent papers on this diagnosis. Recent findings 1) The genetic basis of some rare forms of retinal vascular disease have recently been described. Identified genes include CAPN5, TREX1, and TNFAIP3; 2) Behçet’s disease is a systemic illness that is very commonly associated with occlusive retinal vasculitis; 3) retinal imaging including fluorescein angiography and other newer imaging modalities has proven crucial to the identification and characterization of retinal vasculitis and its complications; 4) although monoclonal antibodies to IL-17A or IL-1 beta failed in trials for Behçet’s disease, antibodies to TNF alpha, either infliximab or adalimumab, have demonstrated consistent benefit in managing this disease. Interferon treatment and B cell depletion therapy via rituximab may be beneficial in certain types of retinal vasculitis. Summary Retinal vasculitis is an important entity for rheumatologists to understand. Retinal vasculitis associated with Behçet’s disease responds to monoclonal antibodies that neutralize TNF, but the many other forms of non-infectious retinal vasculitis may require alternate therapeutic management. PMID:26945335

  5. 酵母培养物对雏鸡生长性能、免疫器官发育和血清相关激素的影响%Effects of Yeast Culture on the Growth Performance,Immune Organs Development and Serum Related Hormones Concentration of Laying Chicks

    Institute of Scientific and Technical Information of China (English)

    张连忠

    2011-01-01

    One hundred and eighty seven-day-old Hy-line Brown laying chicks were chosen and divided into three groups randomly, three replicates per group, twenty chicks per repetition. The chicks in the controlled group were fed with basal diet.The chicks in experiment group Ⅰ and Ⅱ were fed with basal diets distinctively added with 2.5% and 5 % yeast culture for six weeks. The experiment aimed to investigate systematically the effect of yeast culture on the growth performance, immune organs development and serum related hormones concentration of laying chicks. The results showed as follows:①Addition of yeast culture could elevate the average daily gain(P<0. 05),reduce the feed/gain(P<0. 05) and elevate the survival rate(P>0.05) of laying chicks. ②Addition of yeast culture enhanced immune organs development and elevated their weigh index(P<0.05). ③Yeast culture addition elevated serum T3 and T4 concentration(P<0.05) and reduced serum COR concentration(P<0.05). The concentration of GH in experiment group Ⅰ and Ⅱ were higher than that of the control, but the difference was not significant(P>0.05).%选用7日龄海兰褐蛋用公雏鸡180只,随机分成3组(对照组,试验Ⅰ组、试验Ⅱ组),每组设3个重复,每重复20只雏鸡.对照组饲喂基础日粮,试验Ⅰ、Ⅱ组在基础日粮中分别添加2.5%和5%的酵母培养物,试验期6周,研究酵母培养物对雏鸡生长性能、免疫器官发育和血清相关激素的影响.结果表明,①在日粮中添加酵母培养物可以提高蛋雏鸡的平均日增重(P0.05);②酵母培养物能够促进蛋雏鸡免疫器官的发育,提高其器官指数(P0.05).

  6. Effects of the vegetable polyphenols epigallocatechin-3-gallate, luteolin, apigenin, myricetin, quercetin, and cyanidin in primary cultures of human retinal pigment epithelial cells

    Science.gov (United States)

    Chen, Rui; Grosche, Antje; Reichenbach, Andreas; Wiedemann, Peter; Bringmann, Andreas; Kohen, Leon

    2014-01-01

    Purpose Vegetable polyphenols (bioflavonoids) have been suggested to represent promising drugs for treating cancer and retinal diseases. We compared the effects of various bioflavonoids (epigallocatechin-3-gallate [EGCG], luteolin, apigenin, myricetin, quercetin, and cyanidin) on the physiological properties and viability of cultured human retinal pigment epithelial (RPE) cells. Methods Human RPE cells were obtained from several donors within 48 h of death. Secretion of vascular endothelial growth factor (VEGF) was determined with enzyme-linked immunosorbent assay. Messenger ribonucleic acid levels were determined with real-time reverse transcription polymerase chain reaction. Cellular proliferation was investigated with a bromodeoxyuridine immunoassay, and chemotaxis was examined with a Boyden chamber assay. The number of viable cells was determined by Trypan Blue exclusion. Apoptosis and necrosis rates were determined with a DNA fragmentation enzyme-linked immunosorbent assay. The phosphorylation level of signaling proteins was revealed by western blotting. Results With the exception of EGCG, all flavonoids tested decreased dose-dependently the RPE cell proliferation, migration, and secretion of VEGF. EGCG inhibited the secretion of VEGF evoked by CoCl2-induced hypoxia. The gene expression of VEGF was reduced by myricetin at low concentrations and elevated at higher concentrations. Luteolin, apigenin, myricetin, and quercetin induced significant decreases in the cell viability at higher concentration, by triggering cellular necrosis. Cyanidin reduced the rate of RPE cell necrosis. Myricetin caused caspase-3 independent RPE cell necrosis mediated by free radical generation and activation of calpain and phospholipase A2. The myricetin- and quercetin-induced RPE cell necrosis was partially inhibited by necrostatin-1, a blocker of programmed necrosis. Most flavonoids tested diminished the phosphorylation levels of extracellular signal-regulated kinases 1/2 and Akt

  7. Chicks like consonant music.

    Science.gov (United States)

    Chiandetti, Cinzia; Vallortigara, Giorgio

    2011-10-01

    The question of whether preference for consonance is rooted in acoustic properties important to the auditory system or is acquired through enculturation has not yet been resolved. Two-month-old infants prefer consonant over dissonant intervals, but it is possible that this preference is rapidly acquired through exposure to music soon after birth or in utero. Controlled-rearing studies with animals can help shed light on this question because such studies allow researchers to distinguish between biological predispositions and learned preferences. In the research reported here, we found that newly hatched domestic chicks show a spontaneous preference for a visual imprinting object associated with consonant sound intervals over an identical object associated with dissonant sound intervals. We propose that preference for harmonic relationships between frequency components may be related to the prominence of harmonic spectra in biological sounds in natural environments.

  8. Ex Ovo Model for Directly Visualizing Chick Embryo Development

    Science.gov (United States)

    Dorrell, Michael I.; Marcacci, Michael; Bravo, Stephen; Kurz, Troy; Tremblay, Jacob; Rusing, Jack C.

    2012-01-01

    We describe a technique for removing and growing chick embryos in culture that utilizes relatively inexpensive materials and requires little space. It can be readily performed in class by university, high school, or junior high students, and teachers of any grade level should be able to set it up for their students. Students will be able to…

  9. Bioactive compounds isolated from apple, tea, and ginger protect against dicarbonyl induced stress in cultured human retinal epithelial cells

    OpenAIRE

    Sampath, Chethan; Zhu, Yingdong; Sang, Shengmin; Ahmedna, Mohamed

    2016-01-01

    Abstract BackgroundMethylglyoxal (MGO) is known to be a major precursor of advanced glycation end products (AGEs) which are linked to diabetes and its related complications. Naturally occurring bioactive compounds could play an important role in countering AGEs thereby minimizing the risk associated with their formation. MethodsIn this study, eight specific bioactive compounds isolated from apple, tea and ginger were evaluated for their AGEs scavenging activity using Human Retinal Pigment Epi...

  10. Chick stem cells: Current progress and future prospects

    Science.gov (United States)

    Intarapat, Sittipon; Stern, Claudio D.

    2013-01-01

    Chick embryonic stem cells (cESCs) can be derived from cells obtained from stage X embryos (blastoderm stage); these have the ability to contribute to all somatic lineages in chimaeras, but not to the germ line. However, lines of stem cells that are able to contribute to the germ line can be established from chick primordial germ cells (cPGCs) and embryonic germ cells (cEGCs). This review provides information on avian stem cells, emphasizing different sources of cells and current methods for derivation and culture of pluripotent cells from chick embryos. We also review technologies for isolation and derivation of chicken germ cells and the production of transgenic birds. PMID:24103496

  11. Modeling chick to assess diabetes pathogenesis and treatment.

    Science.gov (United States)

    Datar, Savita P; Bhonde, Ramesh R

    2011-01-01

    Animal models have been used extensively in diabetes research. Studies on animal models have contributed to the discovery and purification of insulin, development of new therapeutic approaches, and progress in fundamental and clinical research. However, conventional rodent and large animal mammalian models face ethical, practical, or technical limitations. Therefore, it would be beneficial developing an alternative model for diabetes research which would overcome these limitations. Amongst other vertebrates, birds are phylogenically closer to mammals, and amongst birds, the chick has been used as one of the favored models in developmental biology, toxicology, cancer research, immunology, and drug testing. Chicken eggs are readily available, have a short incubation period and easily accessible embryos. Based on these inimitable advantages, the present review article aims to discuss the suitability of the chick as a model system to study specific aspects of diabetes. The review focuses on the application of i) chick pancreatic islets for screening of antidiabetic agents and for islet banking, (ii) shell-less chick embryo culture as a model to study hyperglycemia-induced malformations observed in mammalian embryos, and (iii) chick chorioallantoic membrane (CAM) to examine glucose-induced endothelial damage leading to inhibition of angiogenesis. Copyright © by Lab & Life Press/SBDR

  12. Advances in Retinal Stem Cell Biology

    Directory of Open Access Journals (Sweden)

    Andrea S Viczian

    2013-01-01

    Full Text Available Tremendous progress has been made in recent years to generate retinal cells from pluripotent cell sources. These advances provide hope for those suffering from blindness due to lost retinal cells. Understanding the intrinsic genetic network in model organisms, like fly and frog, has led to a better understanding of the extrinsic signaling pathways necessary for retinal progenitor cell formation in mouse and human cell cultures. This review focuses on the culture methods used by different groups, which has culminated in the generation of laminated retinal tissue from both embryonic and induced pluripotent cells. The review also briefly describes advances made in transplantation studies using donor retinal progenitor and cultured retinal cells.

  13. Pituitary adenylyl cyclase-activating polypeptide and nerve growth factor use the proteasome to rescue nerve growth factor-deprived sympathetic neurons cultured from chick embryos.

    Science.gov (United States)

    Przywara, D A; Kulkarni, J S; Wakade, T D; Leontiev, D V; Wakade, A R

    1998-11-01

    Removal of nerve growth factor (NGF) from sympathetic neurons initiates a neuronal death program and apoptosis. We show that pituitary adenylyl cyclase-activating polypeptide (PACAP) prevents apoptosis in NGF-deprived sympathetic neurons. PACAP (100 nM) added to culture medium at the time of plating failed to support neuronal survival. However, in neurons grown for 2 days with NGF and then deprived of NGF, PACAP prevented cell death for the next 24-48 h. Uptake of [3H]norepinephrine ([3H]NE) was used as an index of survival and decreased >50% in NGF-deprived cultures within 24 h. PACAP (1-100 nM) restored [3H]NE uptake to 92 +/- 8% of that of NGF-supported controls. Depolarization-induced [3H]NE release in neurons rescued by PACAP was the same as that in NGF-supported neurons. PACAP rescue was not mimicked by forskolin or 8-bromo-cyclic AMP and was not blocked by the protein kinase A inhibitor Rp-adenosine 3',5'-cyclic monophosphothioate. Mobilization of phosphatidylinositol by muscarine failed to support NGF-deprived neurons. Thus, PACAP may use novel signaling to promote survival of sympathetic neurons. The apoptosis-associated caspase CPP32 activity increased approximately fourfold during 6 h of NGF withdrawal (145 +/- 40 versus 38 +/- 17 nmol of substrate cleaved/min/mg of protein) and returned to even below the control level in NGF-deprived, PACAP-rescued cultures (14 +/- 7 nmol/min/mg of protein). Readdition of NGF or PACAP to NGF-deprived cultures reversed CPP32 activation, and this was blocked by lactacystin, a potent and specific inhibitor of the 20S proteasome, suggesting that NGF and PACAP target CPP32 for destruction by the proteasome. As PACAP is a preganglionic neurotransmitter in autonomic ganglia, we propose a novel function for this transmitter as an apoptotic rescuer of sympathetic neurons when the supply of NGF is compromised.

  14. Direct localised measurement of electrical resistivity profile in rat and embryonic chick retinas using a microprobe

    Directory of Open Access Journals (Sweden)

    Harald van Lintel

    2010-01-01

    Full Text Available We report an alternative technique to perform a direct and local measurement of electrical resistivities in a layered retinal tissue. Information on resistivity changes along the depth in a retina is important for modelling retinal stimulation by retinal prostheses. Existing techniques for resistivity-depth profiling have the drawbacks of a complicated experimental setup, a less localised resistivity probing and/or lower stability for measurements. We employed a flexible microprobe to measure local resistivity with bipolar impedance spectroscopy at various depths in isolated rat and chick embryo retinas for the first time. Small electrode spacing permitted high resolution measurements and the probe flexibility contributed to stable resistivity profiling. The resistivity was directly calculated based on the resistive part of the impedance measured with the Peak Resistance Frequency (PRF methodology. The resistivity-depth profiles for both rat and chick embryo models are in accordance with previous mammalian and avian studies in literature. We demonstrate that the measured resistivity at each depth has its own PRF signature. Resistivity profiles obtained with our setup provide the basis for the construction of an electric model of the retina. This model can be used to predict variations in parameters related to retinal stimulation and especially in the design and optimisation of efficient retinal implants.

  15. Cu(II) and Zn(II) ions alter the dynamics and distribution of Mn(II) in cultured chick glial cells

    Energy Technology Data Exchange (ETDEWEB)

    Wedler, F.C.; Ley, B.W. (Dept. of Molecular Cell Biology, Pennsylvania State University, University Park (USA))

    1990-12-01

    Previous studies revealed that Mn(II) is accumulated in cultured glial cells to concentrations far above those present in whole brain or in culture medium. The data indicated that Mn(II) moves across the plasma membrane into the cytoplasm by facilitated diffusion or counter-ion transport with Ca(II), then into mitochondria by active transport. The fact that 1-10 microM Mn(II) ions activate brain glutamine synthetase makes important the regulation of Mn(II) transport in the CNS. Since Cu(II) and Zn(II) caused significant changes in the accumulation of Mn(II) by glia, the mechanisms by which these ions alter the uptake and efflux of Mn(II) ions has been investigated systematically under chemically defined conditions. The kinetics of (54MN)-Mn(II) uptake and efflux were determined and compared under four different sets of conditions: no adducts, Cu(II) or Zn(II) added externally, and with cells preloaded with Cu(II) or Zn(II) in the presence and absence of external added metal ions. Zn(II) ions inhibit the initial velocity of Mn(II) uptake, increase total Mn(II) accumulated, but do not alter the rate or extent Mn(II) efflux. Cu(II) ions increase both the initial velocity and the net Mn(II) accumulated by glia, with little effect on rate or extent of Mn(II) efflux. These results predict that increases in Cu(II) or Zn(II) levels may also increase the steady-state levels of Mn(II) in the cytoplasmic fraction of glial cells, which may in turn alter the activity of Mn(II)-sensitive enzymes in this cell compartment.

  16. Alternative splicing modulates Disabled-1 (Dab1) function in the developing chick retina

    Science.gov (United States)

    Katyal, Sachin; Godbout, Roseline

    2004-01-01

    The Reelin–Disabled 1 (Dab1)-signaling pathway plays a critical role in neuronal cell positioning in the brain. We have isolated two alternatively spliced variants of Dab1 from chick retina, an early form (chDab1-E) expressed in undifferentiated cells and a late form (chDab1-L) expressed in amacrine and ganglion cells. A key difference between the two forms is the exclusion in chDab1-E of two Src-related tyrosine kinase recognition sites implicated in Reelin-mediated Dab1 tyrosine phosphorylation. Retinal cultures transfected with a chDab1-L expression construct undergo a dramatic change in morphology, accompanied by the formation of numerous thin elongated processes, increased tyrosine phosphorylation, activation of Src family kinase(s) and increased levels of the axonal outgrowth protein growth-associated protein-43. In contrast, chDab1-E transfectants retain an undifferentiated morphology. Mutational analysis implicates a specific tyrosine (tyr-198) in the morphological and biochemical alterations associated with chDab1-L expression. We propose that alternative splicing of chDab1 represents an effective and flexible way of regulating the Reelin–Dab1-signaling pathway in a mixed cell population, by ensuring that secreted Reelin activates the signaling cascade only in target neuronal cells. PMID:15057276

  17. Die Fledermaus: regarding optokinetic contrast sensitivity and light-adaptation, chicks are mice with wings.

    Directory of Open Access Journals (Sweden)

    Qing Shi

    Full Text Available BACKGROUND: Through adaptation, animals can function visually under an extremely broad range of light intensities. Light adaptation starts in the retina, through shifts in photoreceptor sensitivity and kinetics plus modulation of visual processing in retinal circuits. Although considerable research has been conducted on retinal adaptation in nocturnal species with rod-dominated retinas, such as the mouse, little is known about how cone-dominated avian retinas adapt to changes in mean light intensity. METHODOLOGY/PRINCIPAL FINDINGS: We used the optokinetic response to characterize contrast sensitivity (CS in the chick retina as a function of spatial frequency and temporal frequency at different mean light intensities. We found that: 1 daytime, cone-driven CS was tuned to spatial frequency; 2 nighttime, presumably rod-driven CS was tuned to temporal frequency and spatial frequency; 3 daytime, presumably cone-driven CS at threshold intensity was invariant with temporal and spatial frequency; and 4 daytime photopic CS was invariant with clock time. CONCLUSION/SIGNIFICANCE: Light- and dark-adaptational changes in CS were investigated comprehensively for the first time in the cone-dominated retina of an avian, diurnal species. The chick retina, like the mouse retina, adapts by using a "day/night" or "cone/rod" switch in tuning preference during changes in lighting conditions. The chick optokinetic response is an attractive model for noninvasive, behavioral studies of adaptation in retinal circuitry in health and disease.

  18. Effect of taurine on GFAP and TauT expressions in rat retinal Müller cells in high glucose culture

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya-jie; XU Hong-xia; ZENG Kai-hong; MI Man-tian

    2007-01-01

    Objective:To detect the expression of glial fibrillary acid protein (GFAP) and taurine transporter (TauT) in the retinal Müller cells in high glucose culture with taurine and to explore the influence of glucose on the taurine transporting, and the possible protective effects of taurine on Müller cells in early diabetic retinopathy. Methods: The Müller cells from the rat retina were cultured in high glucose, and GFAP and TauT expressions were detected in the cells treated with different doses of taurine by immuocytochemical fluorescein staining and Western blotting. Results: High glucose enhanced the expression of GFAP and decreased the expression of TauT in Müller cells. Taurine decreased the up-regulation of GFAP in the cells which was induced by high glucose; 0. 1-10 mmol/L taurine increased the expression of TauT in Müller cells. Conclusion: Taurine can inhibit the changes in Müller cell resulted from high glucose.

  19. Retinitis pigmentosa

    NARCIS (Netherlands)

    Hartong, Dyonne T.; Berson, Eliot L.; Dryja, Thaddeus P.

    2006-01-01

    Hereditary degenerations of the human retina are genetically heterogeneous, with well over 100 genes implicated so far. This Seminar focuses on the subset of diseases called retinitis pigmentosa, in which patients typically lose night vision in adolescence, side vision in young adulthood, and centra

  20. Bioactive compounds isolated from apple, tea, and ginger protect against dicarbonyl induced stress in cultured human retinal epithelial cells.

    Science.gov (United States)

    Sampath, Chethan; Zhu, Yingdong; Sang, Shengmin; Ahmedna, Mohamed

    2016-02-15

    Methylglyoxal (MGO) is known to be a major precursor of advanced glycation end products (AGEs) which are linked to diabetes and its related complications. Naturally occurring bioactive compounds could play an important role in countering AGEs thereby minimizing the risk associated with their formation. In this study, eight specific bioactive compounds isolated from apple, tea and ginger were evaluated for their AGEs scavenging activity using Human Retinal Pigment Epithelial (H-RPE) cells treated with MGO. Among the eight specific compounds evaluated, (-)-epigallocatechin 3-gallate (EGCG) from tea, phloretin in apple, and [6]-shogaol and [6]-gingerol from ginger were found to be most effective in preventing MGO-induced cytotoxicity in the epithelial cells. Investigation of possible underlying mechanisms suggests that that these compounds could act by modulating key regulative detoxifying enzymes via modifying nuclear factor-erythroid 2-related factor 2 (Nrf2) function. MGO-induced cytotoxicity led to increased levels of AGEs causing increase in Nε-(Carboxymethyl) lysine (CML) and glutathione (GSH) levels and over expression of receptor for advanced glycation end products (RAGE). Data also showed that translocation of Nrf2 from cytosol to nucleus was inhibited, which decreased the expression of detoxifying enzyme like heme oxygenase-1 (HO-1). The most potent bioactive compounds scavenged dicarbonyl compounds, inhibited AGEs formation and significantly reduced carbonyl stress by Nrf2 related pathway and restoration of HO-1 expression. These findings demonstrated the protective effect of bioactive compounds derived from food sources against MGO-induced carbonyl stress through activation of the Nrf2 related defense pathway, which is of significant importance for therapeutic interventions in complementary treatment/management of diabetes-related complications. Copyright © 2016. Published by Elsevier GmbH.

  1. Fibrous osteodystrophy in two Northern Royal albatross chicks (Diomedea sanfordi).

    Science.gov (United States)

    Morgan, K J; Alley, M R; Gartrell, B D; Thompson, K G; Perriman, L

    2011-09-01

    In February 2004, two Northern Royal albatross chicks aged 20 and 25 days old were presented for necropsy. Both chicks had been hand-fed in situ at a breeding colony, from 2-3 days post-hatch. The hand-rearing diet consisted of boneless hoki fillets (Macraronus novaezelandiae), electrolytes, and sooty shearwater (Puffinus griseus) proventricular oil obtained as a by-product of cultural harvest. Routine necropsies on the affected chicks revealed many bones were soft and easily bent. Radiography and histopathology revealed decreased bone density, pathological fractures, and extensive remodelling suggestive of fibrous osteodystrophy. Nutritional secondary hyperparathyroidism, resulting from an imbalance in the dietary Ca:P ratio. The imbalance in the dietary Ca:P ratio was a result of feeding deboned and eviscerated fish. This investigation also highlighted potential health risks associated with the practice of feeding stored rancid proventricular oil, including the destruction of fat-soluble vitamins. It is therefore possible that oxidative degradation of vitamin D may have contributed to the development of nutritional secondary hyperparathyroidism. Subsequently, dietary recommendations for supplementary feeding of orphaned Northern Royal albatross chicks include the feeding of whole human-grade fish with an appropriate Ca:P ratio, and the exclusion of proventricular oil. These cases highlight the need for scientific input into wildlife conservation projects, as lack of appropriate nutritional advice resulted in the feeding of a nutritionally inadequate diet. Following the recommended changes in diet, no further cases of osteodystrophy have been diagnosed in hand-raised chicks in the albatross colony.

  2. Comparing three methods of co-culture of retinal pigment epithelium with progenitor cells derived human embryonic stem cells

    Directory of Open Access Journals (Sweden)

    Noushin Amirpour

    2013-01-01

    The adherent cells were morphologically examined using phase contrast microscopy and characterized by immunofluorescent staining and reverse transcription-polymerase chain reaction (RT-PCR Results: Evaluation of immunostaining showed that hESC, highly (>80% can be directed to the RPs fate. Upon co-culture of RPCs with RPE sheet using insert for 2 weeks or by the cell-to-cell contact, these cells differentiated to neural retina and expressed photoreceptor-specific markers. However, in direct co-culture, some mature photoreceptor markers like arrestin expressed in compare with indirect co-culture. Conclusions: The expression of late photoreceptor marker could be improved when RPE cells seeded on RPCs in compare with the use of insert.

  3. Retroviral Vector-Mediated Gene Transfer into the Chick Optic Vesicle by In Ovo Electroporation

    Science.gov (United States)

    Sakuta, Hiraki; Suzuki, Ryoko; Noda, Masaharu

    The chick embryo offers many advantages for developmental studies over other vertebrate embryos as it allows easy access for in ovo surgical manipulations, such as tissue transplantation and the implantation of cultured cells or chemically treated beads for the local release of humoral factors. In particular, owing to its external position in the embryo, the chick eye is a popular model for studying the patterning mechanism of the central nervous system (CNS). This patterning has a crucial role in shaping functional organization because it is the basis of the specific wiring in the CNS. Genetic analysis is not easy in the chick, as compared with the mouse for which transgene introduction or gene targeting techniques have been well established. However, because methods for the expression of exogenous genes and for gene silencing in the chick embryo have been recently developed, the functional analysis of genes has become possible in combination with classical techniques of developmental biology and neurobiology.

  4. Retinitis pigmentosa

    Directory of Open Access Journals (Sweden)

    Hamel Christian

    2006-10-01

    Full Text Available Abstract Retinitis pigmentosa (RP is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. Prevalence of non syndromic RP is approximately 1/4,000. The most common form of RP is a rod-cone dystrophy, in which the first symptom is night blindness, followed by the progressive loss in the peripheral visual field in daylight, and eventually leading to blindness after several decades. Some extreme cases may have a rapid evolution over two decades or a slow progression that never leads to blindness. In some cases, the clinical presentation is a cone-rod dystrophy, in which the decrease in visual acuity predominates over the visual field loss. RP is usually non syndromic but there are also many syndromic forms, the most frequent being Usher syndrome. To date, 45 causative genes/loci have been identified in non syndromic RP (for the autosomal dominant, autosomal recessive, X-linked, and digenic forms. Clinical diagnosis is based on the presence of night blindness and peripheral visual field defects, lesions in the fundus, hypovolted electroretinogram traces, and progressive worsening of these signs. Molecular diagnosis can be made for some genes, but is not usually performed due to the tremendous genetic heterogeneity of the disease. Genetic counseling is always advised. Currently, there is no therapy that stops the evolution of the disease or restores the vision, so the visual prognosis is poor. The therapeutic approach is restricted to slowing down the degenerative process by sunlight protection and vitaminotherapy, treating the complications (cataract and macular edema, and helping patients to cope with the social and psychological impact of blindness. However, new therapeutic strategies are emerging from intensive research (gene therapy, neuroprotection, retinal prosthesis.

  5. Experimental toxoplasmosis in broiler chicks.

    Science.gov (United States)

    Kaneto, C N; Costa, A J; Paulillo, A C; Moraes, F R; Murakami, T O; Meireles, M V

    1997-05-01

    To evaluate chicken toxoplasmosis both as an economic and a public health subject, 84 broiler chicks of a commercial strain, 30 days old, were distributed into seven groups of 12 birds (three replications of four chicks) experimentally infected with three developing T. gondii stages of the P strain as follows: tachyzoites, intravenous (two groups: 5.0 x 10(5) and 5.0 x 10(6)), cysts, per os (two groups: 1.0 x 10(2) and 1.0 x 10(3)) and oocysts, per os (three groups: 5.0 x 10(2), 5.0 x 10(3) and 5.0 x 10(4)). Twelve chicks received only a placebo (control group). During the next 30 days the following parameters were estimated: productivity (weight gain and feed conversion), clinical signs, including rectal temperature and parasitemia (bioassay). No clinical signs suggesting toxoplasmosis were seen and no statistical differences on productivity standards were found in comparison between inoculated and control chicks. However, fowls inoculated with tachyzoites and oocysts occasionally showed hyperthermia. Some haematological changes were detected in fowls inoculated with T. gondii. Anatomo-histopathological changes were not observed. From 14 parasitemias detected, 35.7% appeared on the 5th day after inoculation and 57.1% of them resulted from oocysts inoculation. After 30-35 days all birds were slaughtered: fragments from 12 organs or tissues from each of them were subjected to artificial peptic digestion and after that injected into T. gondii antibody-free mice (IIFR). T. gondii was detected in brain (12), pancreas (five), spleen (five), retina (five), kidney (two), heart (four), proventriculus (three), liver (two), intestine (two), lung (one), and skeletal muscle (one). Similar to observations with parasitemia, from 42 T. gondii isolations, 59.5% came from chicks which had received oocysts. It can thus be inferred that the developing form, expelled by cats, is the most important for T. gondii chicken infection and that brain is the most infected organ in birds

  6. TGF-{beta}-stimulated aberrant expression of class III {beta}-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Eun Jee [Department of Ophthalmology, National Health Insurance Corporation Ilsan Hospital, Gyeonggi-do (Korea, Republic of); Chun, Ji Na; Jung, Sun-Ah [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of); Cho, Jin Won [Department of Biology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Lee, Joon H., E-mail: joonhlee@konyang.ac.kr [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of)

    2011-11-18

    Highlights: Black-Right-Pointing-Pointer TGF-{beta} induces aberrant expression of {beta}III in RPE cells via the ERK pathway. Black-Right-Pointing-Pointer TGF-{beta} increases O-GlcNAc modification of {beta}III in RPE cells. Black-Right-Pointing-Pointer Mature RPE cells have the capacity to express a neuron-associated gene by TGF-{beta}. -- Abstract: The class III {beta}-tubulin isotype ({beta}{sub III}) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III {beta}-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-{beta} (TGF-{beta}) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-{beta} on the aberrant expression of class III {beta}-tubulin and the intracellular signaling pathway mediating these changes. TGF-{beta}-induced aberrant expression and O-linked-{beta}-N-acetylglucosamine (O-GlcNac) modification of class III {beta}-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-{beta} also stimulated phosphorylation of ERK. TGF-{beta}-induced aberrant expression of class III {beta}-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-{beta} stimulated aberrant expression of class III {beta}-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-{beta} stimulation and provide useful information

  7. The Apical Localization of Na+, K+-ATPase in Cultured Human Retinal Pigment Epithelial Cells Depends on Expression of the β2 Subunit

    Science.gov (United States)

    Lobato-Álvarez, Jorge A.; Roldán, María L.; López-Murillo, Teresa del Carmen; González-Ramírez, Ricardo; Bonilla-Delgado, José; Shoshani, Liora

    2016-01-01

    Na+, K+-ATPase, or the Na+ pump, is a key component in the maintenance of the epithelial phenotype. In most epithelia, the pump is located in the basolateral domain. Studies from our laboratory have shown that the β1 subunit of Na+, K+-ATPase plays an important role in this mechanism because homotypic β1-β1 interactions between neighboring cells stabilize the pump in the lateral membrane. However, in the retinal pigment epithelium (RPE), the Na+ pump is located in the apical domain. The mechanism of polarization in this epithelium is unclear. We hypothesized that the apical polarization of the pump in RPE cells depends on the expression of its β2 subunit. ARPE-19 cells cultured for up to 8 weeks on inserts did not polarize, and Na+, K+-ATPase was expressed in the basolateral membrane. In the presence of insulin, transferrin and selenic acid (ITS), ARPE-19 cells cultured for 4 weeks acquired an RPE phenotype, and the Na+ pump was visible in the apical domain. Under these conditions, Western blot analysis was employed to detect the β2 isoform and immunofluorescence analysis revealed an apparent apical distribution of the β2 subunit. qPCR results showed a time-dependent increase in the level of β2 isoform mRNA, suggesting regulation at the transcriptional level. Moreover, silencing the expression of the β2 isoform in ARPE-19 cells resulted in a decrease in the apical localization of the pump, as assessed by the mislocalization of the α2 subunit in that domain. Our results demonstrate that the apical polarization of Na+, K+-ATPase in RPE cells depends on the expression of the β2 subunit. PMID:27774068

  8. The Apical Localization of Na+, K+-ATPase in Cultured Human Retinal Pigment Epithelial Cells Depends on Expression of the β2 Subunit

    Directory of Open Access Journals (Sweden)

    Jorge Lobato Álvarez

    2016-10-01

    Full Text Available Na+, K+-ATPase, or the Na+ pump, is a key component in the maintenance of the epithelial phenotype. In most epithelia, the pump is located in the basolateral domain. Studies from our laboratory have shown that the β1 subunit of Na+, K+-ATPase plays an important role in this mechanism because homotypic β1-β1 interactions between neighboring cells stabilize the pump in the lateral membrane. However, in the retinal pigment epithelium (RPE, the Na+ pump is located in the apical domain. The mechanism of polarization in this epithelium is unclear. We hypothesized that the apical polarization of the pump in RPE cells depends on the expression of its β2 subunit. ARPE-19 cells cultured for up to 8 weeks on inserts did not polarize, and Na+, K+-ATPase was expressed in the basolateral membrane. In the presence of insulin, transferrin and selenic acid (ITS, ARPE-19 cells cultured for 4 weeks acquired an RPE phenotype, and the Na+ pump was visible in the apical domain. Under these conditions, Western blot analysis was employed to detect the β2 isoform and immunofluorescence analysis revealed an apparent apical distribution of the β2 subunit. qPCR results showed a time-dependent increase in the level of β2 isoform mRNA, suggesting regulation at the transcriptional level. Moreover, silencing the expression of the β2 isoform in ARPE-19 cells resulted in a decrease in the apical localization of the pump, as assessed by the mislocalization of the α2 subunit in that domain. Our results demonstrate that the apical polarization of Na+, K+-ATPase in RPE cells depends on the expression of the β2 subunit.

  9. Involvement of calpain/p35-p25/Cdk5/NMDAR signaling pathway in glutamate-induced neurotoxicity in cultured rat retinal neurons.

    Directory of Open Access Journals (Sweden)

    Yanying Miao

    Full Text Available We investigated possible involvement of a calpain/p35-p25/cyclin-dependent kinase 5 (Cdk5 signaling pathway in modifying NMDA receptors (NMDARs in glutamate-induced injury of cultured rat retinal neurons. Glutamate treatment decreased cell viability and induced cell apoptosis, which was accompanied by an increase in Cdk5 and p-Cdk5(T15 protein levels. The Cdk5 inhibitor roscovitine rescued the cell viability and inhibited the cell apoptosis. In addition, the protein levels of both calpain 2 and calpain-specific alpha-spectrin breakdown products (SBDPs, which are both Ca(2+-dependent, were elevated in glutamate-induced cell injury. The protein levels of Cdk5, p-Cdk5(T15, calpain 2 and SBDPs tended to decline with glutamate treatments of more than 9 h. Furthermore, the elevation of SBDPs was attenuated by either D-APV, a NMDAR antagonist, or CNQX, a non-NMDAR antagonist, but was hardly changed by the inhibitors of intracellular calcium stores dantrolene and xestospongin. Moreover, the Cdk5 co-activator p35 was significantly up-regulated, whereas its cleaved product p25 expression showed a transient increase. Glutamate treatment for less than 9 h also considerably enhanced the ratio of the Cdk5-phosphorylated NMDAR subunit NR2A at Ser1232 site (p-NR2A(S1232 and NR2A (p-NR2A(S1232/NR2A, and caused a translocation of p-NR2A(S1232 from the cytosol to the plasma membrane. The enhanced p-NR2A(S1232 was inhibited by roscovitine, but augmented by over-expression of Cdk5. Calcium imaging experiments further showed that intracellular Ca(2+ concentrations ([Ca(2+](i of retinal cells were steadily increased following glutamate treatments of 2 h, 6 h and 9 h. All these results suggest that the activation of the calpain/p35-p25/Cdk5 signaling pathway may contribute to glutamate neurotoxicity in the retina by up-regulating p-NR2A(S1232 expression.

  10. The Retinal Pigment Epithelium: a Convenient Source of New Photoreceptor cells?

    Directory of Open Access Journals (Sweden)

    Shu-Zhen Wang

    2014-01-01

    Full Text Available Recent success in restoring visual function through photoreceptor replacement in mouse models of photoreceptor degeneration intensifies the need to generate or regenerate photoreceptor cells for the ultimate goal of using cell replacement therapy for blindness caused by photoreceptor degeneration. Current research on deriving new photoreceptors for replacement, as regenerative medicine in general, focuses on the use of embryonic stem cells and induced pluripotent stem (iPS cells to generate transplantable cells. Nonetheless, naturally occurring regeneration, such as wound healing, involves awakening cells at or near a wound site to produce new cells needed to heal the wound. Here we discuss the possibility of tweaking an ocular tissue, the retinal pigment epithelium (RPE, to produce photoreceptor cells in situ in the eye. Unlike the neural retina, the RPE in adult mammals maintains cell proliferation capability. Furthermore, progeny cells from RPE proliferation may differentiate into cells other than RPE. The combination of proliferation and plasticity opens a question of whether they could be channeled by a regulatory gene with pro-photoreceptor activity towards photoreceptor production. Studies using embryonic chick and transgenic mouse showed that indeed photoreceptor-like cells were produced in culture and in vivo in the eye using genedirected reprogramming of RPE cells, supporting the feasibility of using the RPE as a convenient source of new photoreceptor cells for in situ retinal repair without involving cell transplantation.

  11. 3-Dimensional modelling of chick embryo eye development and growth using high resolution magnetic resonance imaging.

    Science.gov (United States)

    Goodall, Nicola; Kisiswa, Lilian; Prashar, Ankush; Faulkner, Stuart; Tokarczuk, Paweł; Singh, Krish; Erichsen, Jonathan T; Guggenheim, Jez; Halfter, Willi; Wride, Michael A

    2009-10-01

    Magnetic resonance imaging (MRI) is a powerful tool for generating 3-dimensional structural and functional image data. MRI has already proven valuable in creating atlases of mouse and quail development. Here, we have exploited high resolution MRI to determine the parameters necessary to acquire images of the chick embryo eye. Using a 9.4 Tesla (400 MHz) high field ultra-shielded and refrigerated magnet (Bruker), MRI was carried out on paraformaldehyde-fixed chick embryos or heads at E4, E6, E8, and E10. Image data were processed using established and custom packages (MRICro, ImageJ, ParaVision, Bruker and mri3dX). Voxel dimensions ranged from 62.5 microm to 117.2 microm. We subsequently used the images obtained from the MRI data in order to make precise measurements of chick embryo eye surface area, volume and axial length from E4 to E10. MRI was validated for accurate sizing of ocular tissue features by direct comparison with previously published literature. Furthermore, we demonstrate the utility of high resolution MRI for making accurate measurements of morphological changes due to experimental manipulation of chick eye development, thereby facilitating a better understanding of the effects on chick embryo eye development and growth of such manipulations. Chondroitin sulphate or heparin were microinjected into the vitreous cavity of the right eyes of each of 3 embryos at E5. At E10, embryos were fixed and various eye parameters (volume, surface area, axial length and equatorial diameter) were determined using MRI and normalised with respect to the un-injected left eyes. Statistically significant alterations in eye volume (p < 0.05; increases with chondroitin sulphate and decreases with heparin) and changes in vitreous homogeneity were observed in embryos following microinjection of glycosaminoglycans. Furthermore, in the heparin-injected eyes, significant disturbances at the vitreo-retinal boundary were observed as well as retinal folding and detachment

  12. Mitochondrial "movement" and lens optics following oxidative stress from UV-B irradiation: cultured bovine lenses and human retinal pigment epithelial cells (ARPE-19) as examples.

    Science.gov (United States)

    Bantseev, Vladimir; Youn, Hyun-Yi

    2006-12-01

    Mitochondria provide energy generated by oxidative phosphorylation and at the same time play a central role in apoptosis and aging. As a byproduct of respiration, the electron transport chain is known to be the major intracellular site for the generation of reactive oxygen species (ROS). Exposure to solar and occupational ultraviolet (UV) radiation, and thus production of ROS and subsequent cell death, has been implicated in a large spectrum of skin and ocular pathologies, including cataract. Retinal pigment epithelial cell apoptosis generates photoreceptor dysfunction and ultimately visual impairment. The purpose of this article was to characterize in vitro changes following oxidative stress with UV-B radiation in (a) ocular lens optics and cellular function in terms of mitochondrial dynamics of bovine lens epithelium and superficial cortical fiber cells and (b) human retinal pigment epithelial (ARPE-19) cells. Cultured bovine lenses and confluent cultures of ARPE-19 cells were irradiated with broadband UV-B radiation at energy levels of 0.5 and 1.0 J/cm(2). Lens optical function (spherical aberration) was monitored daily up to 14 days using an automated laser scanning system that was developed at the University of Waterloo. This system consists of a single collimated scanning helium-neon laser source that projects a thin (0.05 mm) laser beam onto a plain mirror mounted at 45 degrees on a carriage assembly. This mirror reflects the laser beam directly up through the scanner table surface and through the lens under examination. A digital camera captures the actual position and slope of the laser beam at each step. When all steps have been made, the captured data for each step position is used to calculate the back vertex distance for each position and the difference in that measurement between beams. To investigate mitochondrial movement, the mitochondria-specific fluorescent dye Rhodamine 123 was used. Time series were acquired with a Zeiss 510 (configuration Meta

  13. Actomyosin organisation for adhesion, spreading, growth and movement in chick fibroblasts

    DEFF Research Database (Denmark)

    Couchman, J R; Rees, D A

    1979-01-01

    Examination of the actomyosin structures and their relation to adhesion, movement and growth in the first fibroblasts migrating from chick heart explants shows striking differences with fibroblasts adapted to grow in culture. The latter have focal adhesions which seem to immobilize them for ancho......Examination of the actomyosin structures and their relation to adhesion, movement and growth in the first fibroblasts migrating from chick heart explants shows striking differences with fibroblasts adapted to grow in culture. The latter have focal adhesions which seem to immobilize them...

  14. Inhibition of the Expression of the Small Heat Shock Protein αB-Crystallin Inhibits Exosome Secretion in Human Retinal Pigment Epithelial Cells in Culture.

    Science.gov (United States)

    Gangalum, Rajendra K; Bhat, Ankur M; Kohan, Sirus A; Bhat, Suraj P

    2016-06-17

    Exosomes carry cell type-specific molecular cargo to extracellular destinations and therefore act as lateral vectors of intercellular communication and transfer of genetic information from one cell to the other. We have shown previously that the small heat shock protein αB-crystallin (αB) is exported out of the adult human retinal pigment epithelial cells (ARPE19) packaged in exosomes. Here, we demonstrate that inhibition of the expression of αB via shRNA inhibits exosome secretion from ARPE19 cells indicating that exosomal cargo may have a role in exosome biogenesis (synthesis and/or secretion). Sucrose density gradient fractionation of the culture medium and cellular extracts suggests continued synthesis of exosomes but an inhibition of exosome secretion. In cells where αB expression was inhibited, the distribution of CD63 (LAMP3), an exosome marker, is markedly altered from the normal dispersed pattern to a stacked perinuclear presence. Interestingly, the total anti-CD63(LAMP3) immunofluorescence in the native and αB-inhibited cells remains unchanged suggesting continued exosome synthesis under conditions of impaired exosome secretion. Importantly, inhibition of the expression of αB results in a phenotype of the RPE cell that contains an increased number of vacuoles and enlarged (fused) vesicles that show increased presence of CD63(LAMP3) and LAMP1 indicating enhancement of the endolysosomal compartment. This is further corroborated by increased Rab7 labeling of this compartment (RabGTPase 7 is known to be associated with late endosome maturation). These data collectively point to a regulatory role for αB in exosome biogenesis possibly via its involvement at a branch point in the endocytic pathway that facilitates secretion of exosomes.

  15. CHICKS

    African Journals Online (AJOL)

    JOURNAL OF AGRICULTURE AND SOCIAL RESEARCH VOL. 4, No. ... increase in the use of feed additives as growth promoters in animal production (Manie .... It could also be due to increased absorptive capacity of the small ... PGD project.

  16. Growth patterns of Hawaiian Stilt chicks

    Science.gov (United States)

    Reed, J.M.; Gray, E.M.; Lewis, D.; Oring, L.W.; Coleman, R.; Burr, T.; Luscomb, P.

    1999-01-01

    We studied chick growth and plumage patterns in the endangered Hawaiian Stilt (Himantopus mexicanus knudseni). Body mass of captive chicks closely fit a Gompertz growth curve, revealing a growth coefficient (K) of 0.065 day-1 and point of inflection (T) of 17 days. When chicks fledged about 28 days after hatching, they weighed only 60% of adult body mass; at 42 d, birds still were only 75% of adult mass; culmen, tarsus, and wing chord at fledging also were less than adult size. This trend of continued growth to adult size after fledging is typical for most shorebirds. After hatching, captive chicks grew more rapidly than wild chicks, probably because of an unlimited food supply. We found no evidence for adverse effects of weather on the growth of wild chicks. As with other shorebirds, the tarsus started relatively long, with culmen and then wing chord growing more rapidly in later development. Tarsal and wing chord growth were sigmoidal, whereas culmen growth was linear. We describe plumage characteristics of weekly age classes of chicks to help researchers age birds in the wild.

  17. Enhanced generation of retinal progenitor cells from human retinal pigment epithelial cells induced by amniotic fluid

    Directory of Open Access Journals (Sweden)

    Sanie-Jahromi Fatemeh

    2012-04-01

    Full Text Available Abstract Background Retinal progenitor cells are a convenient source of cell replacement therapy in retinal degenerative disorders. The purpose of this study was to evaluate the expression patterns of the homeobox genes PAX6 and CHX10 (retinal progenitor markers during treatment of human retinal pigment epithelium (RPE cells with amniotic fluid (AF, RPE cells harvested from neonatal cadaver globes were cultured in a mixture of DMEM and Ham's F12 supplemented with 10% FBS. At different passages, cells were trypsinized and co-cultured with 30% AF obtained from normal fetuses of 1416 weeks gestational age. Results Compared to FBS-treated controls, AF-treated cultures exhibited special morphological changes in culture, including appearance of spheroid colonies, improved initial cell adhesion and ordered cell alignment. Cell proliferation assays indicated a remarkable increase in the proliferation rate of RPE cells cultivated in 30% AF-supplemented medium, compared with those grown in the absence of AF. Immunocytochemical analyses exhibited nuclear localization of retinal progenitor markers at a ratio of 33% and 27% for CHX10 and PAX6, respectively. This indicated a 3-fold increase in retinal progenitor markers in AF-treated cultures compared to FBS-treated controls. Real-time PCR data of retinal progenitor genes (PAX6, CHX10 and VSX-1 confirmed these results and demonstrated AF's capacity for promoting retinal progenitor cell generation. Conclusion Taken together, the results suggest that AF significantly promotes the rate of retinal progenitor cell generation, indicating that AF can be used as an enriched supplement for serum-free media used for the in vitro propagation of human progenitor cells.

  18. A Chick Embryo in-Vitro Model of Knee Morphogenesis

    Directory of Open Access Journals (Sweden)

    Edward K. Rodriguez

    2016-04-01

    Full Text Available Background: In this feasibility study, a mechanically loaded in-vitro tissue culture model of joint morphogenesis using the isolated lower extremity of the 8 day old chick embryo was developed to assess the effects of mechanical loading on joint morphogenesis. Methods: The developed in-vitro system allows controlled flexion and extension of the chick embryonic knee with a range of motion of 20 degrees from a resting position of 90-100 degrees of flexion. Joint morphogenesis at 2, 3, 4 and 7 days of culture was assessed by histology and micro MRI in 4 specimen types: undisturbed in-ovo control embryos, in-ovo paralyzed embryos, in-vitro unloaded limb cultures, and in-vitro loaded limb cultures. Relative glycosaminoglycan (GAG concentration across the joint was assessed with an MRI technique referred to as dGEMRIC (delayed gadolinium enhanced MRI of cartilage where T1 is proportional to glycosaminoglycan concentration. Results: Average T1 over the entire tissue image for the normal control (IC knee was 480 msec; for the 4 day loaded specimen average T1 was 354 msec; and for the 7 day loaded specimens T1 was 393 msec. The 4 day unloaded specimen had an average T1 of 279 msec while the 7 day unloaded specimen had an average T1 of 224 msec. The higher T1 values in loaded than unloaded specimens suggest that more glycosaminoglycan is produced in the loaded culture than in the unloaded preparation. Conclusion: Isolated limb tissue cultures under flexion-extension load can be viable and exhibit more progression of joint differentiation and glycosaminoglycan production than similarly cultured but unloaded specimens. However, when compared with controls consisting of intact undisturbed embryos in-ovo , the isolated loaded limbs in culture do not demonstrate equivalent amounts of absolute growth or joint differentiation.

  19. Inhibition of vascular endothelial growth factor gene expression by T7-siRNAs in cultured human retinal pigment epithelial cells

    Institute of Scientific and Technical Information of China (English)

    LI Guang-yu; FAN Bin; WU Ya-zhen; WANG Xin-rui; WANG Yao-hui; WU Jia-xiang

    2005-01-01

    Background Retinal pigment epithelial (RPE) cells play an important role in the occurrence of choroidal neovascularization (CNV). Vascular endothelial growth factor (VEGF) as a positive regulatory growth factor is produced by the RPE in an autocrine or paracrine manner, promoting CNV development. Duplexes of 21 nt RNAs, known as short interfering RNAs (siRNAs), efficiently inhibit gene expression by RNA interference when introduced into mammalian cells. We searched for an efficient siRNA to interfere with VEGF expression in RPE cells and shed light on the treatment of CNV.Methods Human primary RPE (hRPE) cells were cultured and identified. Three pairs of siRNAs were designed according to the sequence of VEGF 1-5 extrons and synthesized by T7 RNA polymerase transcription in vitro. To evaluate the inhibitory activity of T7-siRNAs, hRPE cells were transfected via siPORT Amine. The interfering effect of T7-siRNAs in hRPE cells was examined by semiquantitative reverse transcription-polymerase chain reaction and immunofluorescence. Results Three pairs of T7-siRNAs synthesized by in vitro transcription with T7 RNA polymerase suppressed VEGF gene expression with efficiency from 65% to 90%. T7-siRNA (B), targeted region at 207 nt to 228 nt and double stranded for 21 nt with 2 nt UU 3' overhangs, was the most effective sequence tested for inhibition of VEGF expression in hRPE cells. Compared with nontransfected cells, the mean fluorescence in hRPE cells transfected with T7-sRNAs was significantly less (P<0.01). siRNA with a single-base mismatch and ssRNA(+) did not show suppressing effect. Furthermore, it was found that siRNAs had a dose dependent inhibitory effect (5 to 10 pmol).Conclusion T7-siRNA can effectively and specifically suppress VEGF expression in hRPE cells and may be a new way to treat CNV.

  20. Up-regulation of HIF-1α and VEGF Expression by Elevated Glucose Concentration and Hypoxia in Cultured Human Retinal Pigment Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    XIAO Qing; ZENG Shuiqing; LING Shiqi; LV Mingliang

    2006-01-01

    In order to explore the effect of high glucose concentration and high glucose concentration with hypoxia on the production of hypoxia-inducible factor-1 α (HIF-1α) and vascular endothelial growth factor (VEGF), human RPE cells were cultured in 5.56 mmol/L glucose (control group), 5.56 mmol/L glucose with 150 μ mol/L CoCl2 (hypoxic group), 25 mmol/L glucose (high glucose group)and 25 mmol/L glucose with 150 μ mol/L CoCl2 (combination group). RT-PCR was used to detect the expression of HIF-1α and VEGF mRNAs. Western blot analysis was used to measure the levels of HIF-1α and VEGF proteins. Although the small amount of HIF-1α protein was able to be detected in high glucose group but not in control group, there was no significant difference between the expression of HIF-1α mRNA of RPE cells in high glucose group and that of RPE cells in control group.As compared with RPE cells in control group, the mRNA expression and the protein synthesis of VEGF in high glucose group were up-regulated. As compared with RPE cells in hypoxic group, the expression of HIF-1α mRNA of RPE cells in combination group was not different, but the protein synthesis of HIF-1 α, the mRNA expression and the protein synthesis of VEGF were more obviously up-regulated. In conclusion, high concentration glucose mainly influence the protein synthesis of HIF-1α of RPE cell, and HIF-1α protein is able to be accumulated in high concentration glucose.Under hypoxia, the HIF-1α protein induced by high concentration glucose is more stable, and the expression of VEGF is obviously increased. It is suggested that high concentration glucose may play a role in retinal neovascularization, especially at ischemia stage of diabetic retinopathy.

  1. Retinal synaptic regeneration via microfluidic guiding channels.

    Science.gov (United States)

    Su, Ping-Jung; Liu, Zongbin; Zhang, Kai; Han, Xin; Saito, Yuki; Xia, Xiaojun; Yokoi, Kenji; Shen, Haifa; Qin, Lidong

    2015-08-28

    In vitro culture of dissociated retinal neurons is an important model for investigating retinal synaptic regeneration (RSR) and exploring potentials in artificial retina. Here, retinal precursor cells were cultured in a microfluidic chip with multiple arrays of microchannels in order to reconstruct the retinal neuronal synapse. The cultured retinal cells were physically connected through microchannels. Activation of electric signal transduction by the cells through the microchannels was demonstrated by administration of glycinergic factors. In addition, an image-based analytical method was used to quantify the synaptic connections and to assess the kinetics of synaptic regeneration. The rate of RSR decreased significantly below 100 μM of inhibitor glycine and then approached to a relatively constant level at higher concentrations. Furthermore, RSR was enhanced by chemical stimulation with potassium chloride. Collectively, the microfluidic synaptic regeneration chip provides a novel tool for high-throughput investigation of RSR at the cellular level and may be useful in quality control of retinal precursor cell transplantation.

  2. Anasarca and myopathy in ostrich chicks.

    Science.gov (United States)

    Philbey, A W; Button, C; Gestier, A W; Munro, B E; Glastonbury, J R; Hindmarsh, M; Love, S C

    1991-07-01

    Twenty ostrich chicks that died at, or within, 1 week after hatching were examined from 7 farms with poor (43 to 75%) hatchability. All chicks had anasarca and 15 had mild, generalised, acute degenerative changes in the complexus and pelvic limb muscles. One had fibrinoid degeneration of arterioles. Biochemical examinations produced no evidence of deficiencies of selenium, vitamin A or vitamin E. The syndrome was related to high relative humidity during incubation. Malpositioning also was a cause of embryo mortality.

  3. USE OF THE CHICK EMBRYO IN MAINTAINING AND RESTORING VIRULENCE OF NEISSERIA GONORRHOEAE

    Science.gov (United States)

    Walsh, Martin J.; Brown, Bobby C.; Brown, Leonard; Pirkle, Carl I.

    1963-01-01

    Walsh, Martin J. (Communicable Disease Center, Atlanta, Ga.), Bobby C. Brown, Leonard Brown, and Carl I. Pirkle. Use of the chick embryo in maintaining and restoring virulence of Neisseria gonorrhoeae. J. Bacteriol. 86:478–481. 1963.—Data based on its capabilities of producing acute urethritis in human male volunteers showed that Neisseria gonorrhoeae rapidly decreased in virulence after repeated subculture on chocolate agar medium. Cultures of a particular strain (GCM13) in the allantoic cavity of a developing chick embryo maintained virulence after 82 successive transfers. Another strain (GCF62), after loss of virulence through repeated subculture on chocolate agar, was again able to produce infection after 15 consecutive transfers in chick embryo. Thus, chick embryo apparently had the capability not only to maintain the virulence factor but also to reconstitute virulence. It is postulated that chick embryo serves as a selective medium for the growth of virulent gonococci, permitting rapid multiplication of these organisms and suppressing growth of the nonvirulent organisms. PMID:14066424

  4. β-Catenin inactivation is a pre-requisite for chick retina regeneration.

    Directory of Open Access Journals (Sweden)

    Jie Zhu

    Full Text Available In the present study we explored the role of β-catenin in mediating chick retina regeneration. The chick can regenerate its retina by activating stem/progenitor cells present in the ciliary margin (CM of the eye or via transdifferentiation of the retinal pigmented epithelium (RPE. Both modes require fibroblast growth factor 2 (FGF2. We observed, by immunohistochemistry, dynamic changes of nuclear β-catenin in the CM and RPE after injury (retinectomy. β-Catenin nuclear accumulation was transiently lost in cells of the CM in response to injury alone, while the loss of nuclear β-catenin was maintained as long as FGF2 was present. However, nuclear β-catenin positive cells remained in the RPE in response to injury and were BrdU-/p27+, suggesting that nuclear β-catenin prevents those cells from entering the cell cycle. If FGF2 is present, the RPE undergoes dedifferentiation and proliferation concomitant with loss of nuclear β-catenin. Moreover, retinectomy followed by disruption of active β-catenin by using a signaling inhibitor (XAV939 or over-expressing a dominant negative form of Lef-1 induces regeneration from both the CM and RPE in the absence of FGF2. Our results imply that β-catenin protects cells of the CM and RPE from entering the cell cycle in the developing eye, and specifically for the RPE during injury. Thus inactivation of β-catenin is a pre-requisite for chick retina regeneration.

  5. Activation of Neuropeptide Y Receptors Modulates Retinal Ganglion Cell Physiology and Exerts Neuroprotective Actions In Vitro

    DEFF Research Database (Denmark)

    Martins, João; Elvas, Filipe; Brudzewsky, Dan

    2015-01-01

    Neuropeptide Y (NPY) is expressed in mammalian retina but the location and potential modulatory effects of NPY receptor activation remain largely unknown. Retinal ganglion cell (RGC) death is a hallmark of several retinal degenerative diseases, particularly glaucoma. Using purified RGCs and ex vivo...... receptor activation, at the level of inner or outer plexiform layers, leads to modulation of RGC receptive field properties. Using in vitro cultures of rat retinal explants exposed to NMDA, we found that NPY pretreatment prevented NMDA-induced cell death. However, in an animal model of retinal ischemia...... actions detected in retinal explants can be translated into animal models of retinal degenerative diseases....

  6. Ejecting chick cheats: a changing paradigm?

    Directory of Open Access Journals (Sweden)

    Grim Tomáš

    2011-06-01

    Full Text Available Abstract Evolutionary arms-races between avian brood parasites and their hosts have typically resulted in some spectacular adaptations, namely remarkable host ability to recognize and reject alien eggs and, in turn, sophisticated parasite egg mimicry. In a striking contrast to hosts sometimes rejecting even highly mimetic eggs, the same species typically fail to discriminate against highly dissimilar parasite chicks. Understanding of this enigma is still hampered by the rarity of empirical tests - and consequently evidence - for chick discrimination. Recent work on Australian host-parasite systems (Gerygone hosts vs. Chalcites parasites, increased not only the diversity of hosts showing chick discrimination, but also discovered an entirely novel host behavioural adaptation. The hosts do not desert parasite chicks (as in all previously reported empirical work but physically remove living parasites from their nests. Here, I briefly discuss these exciting findings and put them in the context of recent empirical and theoretical work on parasite chick discrimination. Finally, I review factors responsible for a relatively slow progress in this research area and suggest most promising avenues for future research.

  7. Retroviral expression of connexins in embryonic chick lens.

    Science.gov (United States)

    Jiang, J X; Goodenough, D A

    1998-03-01

    To develop an in vivo model system in which exogenous proteins can be expressed in embryonic chick lens and to further understand the function of connexin-mediated gap junction intercellular communication in lens cell biology. RCAS(A) is a replication-competent chicken retrovirus that infects dividing cells. Retroviral constructs were prepared containing alkaline phosphatase (AP) and FLAG-tagged connexins. Chick lenses were infected in situ by injecting virus into the lumen of lens vesicles at stage 18, cultures were taken at various periods. The lenses were then dissected, and the expressed proteins were visualized by AP histochemical examination and immunostaining. Twenty-four hours after infection, alkaline phosphatase could be seen in epithelia and fibers. As lens fiber maturation progressed, however, the alkaline phosphatase staining was lost as the fibers matured, presumably because of the proteolytic removal of the enzyme. By 72 hours, alkaline phosphatase staining could still be observed in epithelial cells and in differentiating fibers in the bow region but not in the mature lens fibers. FLAG-tagged exogenous lens connexins were also abundantly expressed by viral infection. The exogenous connexins were localized at the cell surfaces in junctional maculae and showed the same cell-type specific distribution as that of their endogenous connexin counterparts. An in vivo model system has been developed in the chick that provides opportunities to study the expression of wild-type and mutant proteins during lens differentiation. Expression of wild-type connexins has revealed that the characteristic distribution of the three different lens connexins is maintained even when expression is driven by a viral promoter.

  8. Control temperature of young chicks to reduce mortality

    NARCIS (Netherlands)

    Lourens, A.; Kuijpers, M.

    2002-01-01

    Individual chicks may have different environmental temperature demands. The trick is to provide every chick with the right body temperature. By measuring individual chick temperatures, hatchery staff and broiler growers or layer producers are better able to provide the right environmental temperatur

  9. Hydrogen peroxide potentiates organophosphate toxicosis in chicks

    Directory of Open Access Journals (Sweden)

    Banan K. Al-Baggou

    2011-11-01

    Full Text Available Objective: The purpose of the present study was to examine the effect of hydrogen peroxide(H2O2 on the acute toxicity of organophosphate insecticides dichlorvos and diazinon and their inhibitoryactions on plasma, brain and liver cholinesterase activities. Material and Methods: H2O2 was given indrinking water (0.5% v/v for 2 weeks in unsexed day old chicks, a regimen known to induce oxidativestress in this species. A control group received drinking tap water. All experiments were conducted onthe chicks at the age of 15 days after exposure to H2O2. The acute (24 h oral LD50 values of dichlorvosand diazinon in the insecticidal preparations as determined by the up-and-down method in the controlchicks were 9.4 and 15.6 mg/kg, respectively. Results: The poisoned chicks manifested signs ofcholinergic toxicosis within one hour after the dosing including salivation, lacrimation, gasping, frequentdefecation, drooping of wings, tremors, convulsions and recumbency. The acute (24 h oral LD50 valuesof dichlorvos and diazinon in chicks provided with H2O2 were reduced to 3.5 and 6.5 mg/kg, by 63 and58%, respectively when compared to respective control LD50 values. The intoxicated chicks also showedcholinergic signs of toxicosis as described above. Plasma, brain and liver cholinesterase activities of thechicks exposed to H2O2 were significantly lower than their respective control (H2O values by 25, 28 and27%, respectively. Oral dosing of chicks with dichlorvos at 3 mg/kg significantly inhibited cholinesteraseactivities in the plasma, brain and liver of both control (42-67% and H2O2-treated (15-59% chicks.Diazinon at 5 mg/kg, orally also inhibited cholinesterase activities in the plasma, brain and liver of bothcontrol (36-66% and H2O2-treated (15-30% chicks. In the H2O2 groups, dichlorvos inhibition of livercholinesterase activity and diazinon inhibition of liver and brain cholinesterase activities weresignificantly lesser than those of the respective values of

  10. Transcription factor AP-2delta regulates the expression of polysialyltransferase ST8SIA2 in chick retina.

    Science.gov (United States)

    Li, Xiaodong; Persad, Amit R L; Monckton, Elizabeth A; Godbout, Roseline

    2014-03-03

    The AP-2δ transcription factor is restricted to a subset of retinal ganglion cells. Overexpression of AP-2δ in chick retina results in induction of polysialylated neural cell adhesion molecule (PSA-NCAM) accompanied by misrouting and bundling of ganglion cell axons. Two polysialyltransferases, ST8SIA2 and ST8SIA4, are responsible for polysialylation of NCAM. Here, we investigate the mechanism driving the increase in PSA-NCAM observed upon AP-2δ overexpression. We show that ST8SIA2 is induced by AP-2δ overexpression in chick retina. We use chromatin immunoprecipitation and gel shift assays to demonstrate direct interaction between AP-2δ and the ST8SIA2 promoter. We propose that up-regulation of ST8SIA2 upon AP-2δ overexpression in retina increases ectopic polysialylation of NCAM which in turn causes premature bundling of axons and alters axonal response to guidance cues.

  11. Retinal stem/progenitor cells in the ciliary marginal zone complete retinal regeneration: a study of retinal regeneration in a novel animal model.

    Science.gov (United States)

    Miyake, Ayumi; Araki, Masasuke

    2014-07-01

    Our research group has extensively studied retinal regeneration in adult Xenopus laevis. However, X. laevis does not represent a suitable model for multigenerational genetics and genomic approaches. Instead, Xenopus tropicalis is considered as the ideal model for these studies, although little is known about retinal regeneration in X. tropicalis. In the present study, we showed that a complete retina regenerates at approximately 30 days after whole retinal removal. The regenerating retina was derived from the stem/progenitor cells in the ciliary marginal zone (CMZ), indicating a novel mode of vertebrate retinal regeneration, which has not been previously reported. In a previous study, we showed that in X. laevis, retinal regeneration occurs primarily through the transdifferentiation of retinal pigmented epithelial (RPE) cells. RPE cells migrate to the retinal vascular membrane and reform a new epithelium, which then differentiates into the retina. In X. tropicalis, RPE cells also migrated to the vascular membrane, but transdifferentiation was not evident. Using two tissue culture models of RPE tissues, it was shown that in X. laevis RPE culture neuronal differentiation and reconstruction of the retinal three-dimensional (3-D) structure were clearly observed, while in X. tropicalis RPE culture neither ßIII tubulin-positive cells nor 3-D retinal structure were seen. These results indicate that the two Xenopus species are excellent models to clarify the cellular and molecular mechanisms of retinal regeneration, as these animals have contrasting modes of regeneration; one mode primarily involves RPE cells and the other mode involves stem/progenitor cells in the CMZ.

  12. Mechanism of riboflavin uptake by cultured human retinal pigment epithelial ARPE-19 cells: possible regulation by an intracellular Ca2+-calmodulin-mediated pathway

    OpenAIRE

    Said, Hamid M.; Wang, S.L.; Ma, T Y

    2005-01-01

    In mammalian cells (including those of the ocular system), the water-soluble vitamin B-2 (riboflavin, RF) assumes an essential role in a variety of metabolic reactions and is critical for normal cellular functions, growth and development. Cells of the human retinal pigment epithelium (hRPE) play an important role in providing a sufficient supply of RF to the retina, but nothing is known about the mechanism of the vitamin uptake by these cells and its regulation. Our aim in the present study w...

  13. Retinal remodeling in human retinitis pigmentosa.

    Science.gov (United States)

    Jones, B W; Pfeiffer, R L; Ferrell, W D; Watt, C B; Marmor, M; Marc, R E

    2016-09-01

    Retinitis Pigmentosa (RP) in the human is a progressive, currently irreversible neural degenerative disease usually caused by gene defects that disrupt the function or architecture of the photoreceptors. While RP can initially be a disease of photoreceptors, there is increasing evidence that the inner retina becomes progressively disorganized as the outer retina degenerates. These alterations have been extensively described in animal models, but remodeling in humans has not been as well characterized. This study, using computational molecular phenotyping (CMP) seeks to advance our understanding of the retinal remodeling process in humans. We describe cone mediated preservation of overall topology, retinal reprogramming in the earliest stages of the disease in retinal bipolar cells, and alterations in both small molecule and protein signatures of neurons and glia. Furthermore, while Müller glia appear to be some of the last cells left in the degenerate retina, they are also one of the first cell classes in the neural retina to respond to stress which may reveal mechanisms related to remodeling and cell death in other retinal cell classes. Also fundamentally important is the finding that retinal network topologies are altered. Our results suggest interventions that presume substantial preservation of the neural retina will likely fail in late stages of the disease. Even early intervention offers no guarantee that the interventions will be immune to progressive remodeling. Fundamental work in the biology and mechanisms of disease progression are needed to support vision rescue strategies.

  14. Involvement of Notch signaling in early chick ovarian follicle development.

    Science.gov (United States)

    Li, Jun; Zhao, Dan; Guo, Changquan; Li, Jian; Mi, Yuling; Zhang, Caiqiao

    2016-01-01

    The formation of primordial follicles is a crucial process in the establishment of follicle pools required for the female's reproductive life span. For laying hens, ample follicles are a prerequisite for high laying performance. Notch signaling plays critical roles in germ cell cysts breakdown and in the formation of primordial follicles. Here, we investigated the role of Notch signaling in the ovarian development of post-hatch chicks. Results showed that around post-hatch day 4 (H4), the germ cell cysts broke apart, oocytes became surrounded by squamous pregranulosa cells, and the primordial follicles were then formed. Subsequently, we detected the expression of Notch signaling-related genes including Notch receptors (Notch1, 2), ligands (Jag1, 2 and Dll1, 4), and target genes (Hes1, Hey1). These genes all showed expression at H4 and some of these genes were up-regulated during primordial follicle formation. To evaluate the Notch signaling requirement for early follicular development, we adopted an in vitro ovary culture system. Suppression of Notch signaling by γ-secretase inhibitor induced a decrease of primordial follicles and an increase of germ cells in cysts. Attenuating Notch signaling also inhibited the phosphatidylinositol 3-kinase/protein kinase B pathways and suppressed cadherin expression. These results suggest that Notch signaling is endowed with an indispensable role in primordial follicle formation in post-hatch chicks.

  15. Toxicity of metal mixtures to chick embryos

    Energy Technology Data Exchange (ETDEWEB)

    Birge, W.J.; Roberts, O.W.; Black, J.A.

    1976-09-01

    The toxic effects of mercury/selenium and certain other metal mixtures on the chick embryo are examined to determine whether antagonistic, additive or synergistic interactions occur. White Plymouth Rock chicken eggs were treated by yolk injection with cadmium chloride, mercuric chloride, zinc chloride and sodium selenate. Test aliquots were injected prior to incubation using the needle track procedure. Using a sample size of 200, percent survival was determined as hatchability of experimental eggs/controls. Metal mixtures used included mercury/cadmium, mercury/selenium, mercury/zinc, cadmium/selenium, and cadmium/zinc. Except for mercury/selenium, all other metal mixtures gave actual values that were within 5% of those for additive toxic effects. Actual hatchability frequencies for test concentrations of mercury/selenium indicated a moderate degree of synergism. Results indicate that the strong mercury/selenium synergism which affects embryonic development in the carp does not apply for the chick embryo; that most two-way combinations of cadmium, mercury, selenium and zinc exert purely additive effects on chick hatchability; and that these metal mixtures give no discernible antagonistic interactions which affect survival of chick embryos. (MFB)

  16. 改良的人视网膜血管内皮细胞的培养与鉴定方法%A novel method for culture and identification of primary human retinal microvascular endothelial cells

    Institute of Scientific and Technical Information of China (English)

    毛羽翔; 林少芬; 曾美珍; 田景毅; 唐仕波

    2013-01-01

    Background To optimize the culture method of human retinal microvascular endothelial cells is very important for the study of retinal angiogenesis disease.Human retinal microvascular endothelial cells have been successfully cultured in previous studies,but further improvement of the culture method to harvest higher yields and purity cells is still needed.Objective This study was to design a modified method to isolate and purify human retinal microvascular endothelial cells much easily and quickly,and to compare the expression of specific markers of vascular endothelial cells,factor Ⅷ and CD31/CD34 in the cells.Methods The use of human donor eyeballs was approved by the Ethic Commission of Zhongshan Ophthalmic Center of Sun Yat-sen University.The retina tissue from healthy donor was isolated and digested by the two-step digestion method with 2% trypsin and 0.133% collagenase Ⅳ.Human retinal microvascular endothelial cells were collected and plated in 60 mm dishes coated by 0.1% fibronectin and cultured in endothelial cell-specialized medium supplemented with 10% fetal bovine serum,0.3 mg/L β-endothelial cell growth factor (ECGF) and 100 ng/L sodium heparin.During the culturing,the growth situation of the cells was monitored by morphological observation,and immunohistochemical staining was performed to probe vascular endothelial cell-specific membrane protein CD31,CD34 and factor Ⅷ for identification of the cell purity.Results Human retinal microvascular endothelial cells were isolated successfully from the retina by the twostep digestion method.The primary cultured cells adhered to well 72 hours later and achieved confluence with the typical cobblestone appearance 9 to 10 days after cultured.The cells exhibited the blue nuclei and reddish cytoplasm by regular haematoxylin and eosin stain and showed a strong positive response for CD31,CD34 and factor Ⅷ by immunohistochemistry.The positive dye of CD31 and CD34 was lower than Ⅷ factor in both

  17. Arginine requirement of starting broiler chicks.

    Science.gov (United States)

    Cuca, M; Jensen, L S

    1990-08-01

    Three experiments were conducted to estimate the arginine requirement of male broiler chicks from 0 to 3 wk of age. The experiments were conducted in battery brooders with wires floors, and the birds received water and feed ad libitum. In the first experiment, chicks were fed a diet based on corn, soybean meal, casein, and corn-gluten meal containing 3,200 kcal ME per kg and either 20 or 23% crude protein. Regression analysis indicated an arginine requirement of 1.22% for maximum growth rate and feed efficiency with the 20% protein diet. For chicks fed the 23% protein diet, neither growth rate nor feed efficiency was significantly different among the diets containing arginine ranging from 1.13 to 1.43%. In the second experiment, a basal diet was used containing 17.5% casein and 22.5% protein with arginine ranging from 1.03 to 1.43%. An arginine requirement of 1.18% for maximum body weight gain was estimated by regression analysis, but no significant response to arginine above the basal level was observed for feed efficiency. Performance of chicks fed the basal diet was somewhat reduced because of a difficulty with adherence of feed to the beaks. In a third experiment, three basal diets containing 21, 22, or 23% protein were formulated from practical ingredients without use of casein. The requirement for maximum growth rate and feed efficiency was estimated to be 1.24 to 1.28% for the three diets. The results of these investigations indicate that the arginine requirement for starting chicks suggested by the National Research Council in 1984 of 1.44% in diets containing 3,200 kcal ME per kg is too high for practical diets. The data presented here support an arginine requirement of 1.25%.

  18. Functional analysis of retinal microglia and their effects on progenitors.

    Science.gov (United States)

    Carter, Debra A; Balasubramaniam, Balini; Dick, Andrew D

    2013-01-01

    The identification of stem/progenitor cells within the retinal neural environment has opened up the possibility of therapy via cellular replacement and/or reprogramming of resident cell populations. Within the neuro-retinal niche, following injury or in disease states (including inflammation and degeneration), cellular responses affect tissue homeostasis, reduce cell density, disrupt tissue architecture, and produce scar formation. Microglia (resident retinal immune cell tissue macrophage) are key to the maintenance of retinal homeostasis and are implicated in responses that may influence the control and behavior of retinal progenitors. Factors to consider in the generation of a transplantable cell resource with good migratory and integrative capacity include their yield, purity, and functional viability. Utilizing human postmortem retina, we have created a research platform to isolate, culture, and characterize adult retinal microglia as well as analyze their effect on retinal progenitors. Here, we describe techniques using magnetic labeled bead cell separation to isolate pure populations of retinal CD133(+) precursor cells and CD11b(+) microglia from primary adult retinal cell suspensions (RCSs), enabling flow cytometric cell phenotypic and qPCR genotypic analysis, as well as functional analysis by real-time ratiometric calcium imaging.

  19. Histological characterisation of the ethanol-induced microphthalmia phenotype in a chick embryo model system.

    Science.gov (United States)

    Kennelly, Kevin; Brennan, Deirdre; Chummun, Kushal; Giles, Seamus

    2011-09-01

    The eye is a sensitive indicator of the teratogenic effects of ethanol with ophthalmic defects such as microphthalmia frequently observed in FAS children. In this study, we have optimised the chick-embryo model system to investigate ethanol-induced ocular defects. Injection of 20% ethanol (125μl) directly into the yolk sac of HH-stage 7 embryos resulted in an overall 30% incidence of eye anomalies including microphthalmia. Ocular measurements showed that this treatment regime caused a significant reduction in overall globe size. Histological examination of microphthalmic specimens revealed three subgroups: (1) all ocular structures developed but were significantly retarded compared to age matched controls, (2) the bi-layered optic cup developed but with no evidence of lens induction, and (3) the optic vesicle failed to invaginate but remained as a vesicular structure comprising of a single layer of retinal pigment cells with no evidence of a neuro-retinal cell layer or lens structure. Further analysis identified clusters of apoptotic bodies in the ventral telencephalon, a region responsible for the expression of important genes in ocular specification. These results support a growing body of evidence, indicating that ethanol targets inductive signals in early eye development involving lens formation and retinal ganglion cell differentiation. The possible involvement of Shh, Fgf8, Bmp4 and Pax6 is discussed in relation to these outcomes.

  20. In vitro culture and phagocytosis of human embryonic retinal pigment epithelium%人胚胎视网膜色素上皮细胞的体外培养和吞噬作用

    Institute of Scientific and Technical Information of China (English)

    靳晓亮; 徐国彤; 张文芳; 鲁建华

    2011-01-01

    Objective To analyze the culturing characteristics and phagocytosis of the retinal pigment epithelium (RPE) from human embryo, and to provide the cellular basis for the further research of RPE related diseases. Methods Fresh human embryonic eyeballs (13~15 weeks) were collected, and RPE cells were separated by mechanical and trypsin digestion after microdissec-tion. Human embryonic RPE phagocytosis of retinal outer segments was investigated by using immunofluorescence. Results After the human embryo had developed for 13~15 weeks, the RPE cells could be cultured in vitro according to standard culturing methods. Based on the growth curve, the RPE cells in generations 2~6 were collected for essays and showed the ability of phagocytosis afterwards. Conclusion The method of culturing human embryonic RPE cells is improved, and phagocytosis ability of human embryonic RPE cells is also proved in vitro according to this study.%目的 探讨人胚胎视网膜色素上皮(RPE)细胞分离培养的特性及其吞噬作用.方法 取发育至13~15周的新鲜人胚胎眼球,显微解剖后采用机械胰酶消化法分离培养RPE细胞,应用免疫荧光法观察人胚胎RPE细胞吞噬视网膜光感受细胞外节膜盘.结果 人胚胎发育至13~15周后,RPE细胞可应用标准的培养方法进行体外培养和传代.根据测定的人胚胎RPE细胞生长曲线,取2~6代细胞用于实验培养的人胚胎RPE细胞具备吞噬功能.结论 改进了人胚胎RPE细胞的培养方法,证明人胚胎RPE细胞在体外具有吞噬能力.

  1. Bacterial enteritis in ostrich (Struthio Camelus) chicks in the Western Cape Province, South Africa.

    Science.gov (United States)

    Keokilwe, L; Olivier, A; Burger, W P; Joubert, H; Venter, E H; Morar-Leather, D

    2015-06-01

    Ostrich (Struthio camelus) chicks less than 3 mo age are observed to experience a high mortality rate that is often associated with enteritis. This study was undertaken to investigate the infectious bacteria implicated in ostrich chick enteritis. Postmortems were performed on 122 ostrich chicks aged from 1 d to 3 mo and intestinal samples were subjected to bacterial culture. Bacterial isolates were typed by PCR and serotyping. Escherichia coli (E. coli; 49%) was the most frequently isolated from the samples followed by Clostridium perfringens (C. perfringens; 20%), Enterococcus spp. (16%), and Salmonella spp. (7%). Of the E. coli, 39% were categorized as enteropathogenic E. coli, 4% enterotoxigenic E. coli, and no enterohaemorrhagic E. coli were found. The majority (93%) of C. perfringens was Type A and only 7% was Type E. C. perfringens Types B through D were not present. The netB gene that encodes NetB toxin was identified from 16% of the C. perfringens isolated. All the C. perfringens Type E harbored the netB gene and just 10% of the C. perfringens Type A had this gene. Three Salmonella serotypes were identified: Salmonella Muenchen (S. Muenchen; 80%), S. Hayindongo (13%), and S. Othmarschen (7%). The indication is that the cause of enteritis in ostrich chicks is bacterial-involving: enteropathogenic E. coli and enterotoxigenic E. coli; C. perfringens Types A and E (with the possible influence of netB gene); and S. Muenchen, S. Hayindongo, and S. Othmarschen.

  2. Cytoskeletal elements of chick embryo fibroblasts revealed by detergent extraction.

    Science.gov (United States)

    Brown, S; Levinson, W; Spudich, J A

    1976-01-01

    Treatment of chick embryo fibroblasts with 0.5% Triton X-100 extracts most of the cell protein, leaving an organized part of the cell structure attached to the tissue culture dish. This "Triton cytoskeleton" consists largely of intermediate-sized filaments and bundles of microfilaments. SDS polyacrylamide gel electrophoresis reveals that this cytoskeleton is made up of three main proteins. One protein component is 42,000 daltons and co-migrates with muscle actin. The other two components are 52,000 and 230,000 daltons and remain quantitatively associated with the cytoskeleton during the detergent extraction. The possible identity of these three protein components and their organization into a supramolecular structure is discussed.

  3. Dorzolamide increases retinal oxygen tension after branch retinal vein occlusion

    DEFF Research Database (Denmark)

    Noergaard, Michael Hove; Bach-Holm, Daniella; Scherfig, Erik;

    2008-01-01

    To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs.......To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs....

  4. Neuroprotective Effects of Citicoline in in Vitro Models of Retinal Neurodegeneration

    OpenAIRE

    Andrea Matteucci; Monica Varano; Lucia Gaddini; Cinzia Mallozzi; Marika Villa; Flavia Pricci; Fiorella Malchiodi-Albedi

    2014-01-01

    In recent years, citicoline has been the object of remarkable interest as a possible neuroprotectant. The aim of this study was to investigate if citicoline affected cell survival in primary retinal cultures and if it exerted neuroprotective activity in conditions modeling retinal neurodegeneration. Primary retinal cultures, obtained from rat embryos, were first treated with increasing concentrations of citicoline (up to 1000 µM) and analyzed in terms of apoptosis and caspase activation and c...

  5. Chick Noir”: Shopaholic Meets Double Indemnity

    Directory of Open Access Journals (Sweden)

    Kennedy Victoria

    2017-06-01

    Full Text Available In early 2014, several articles appeared proclaiming the rise to prominence of a new subgenre of the crime novel: “chick noir,” which included popular books like Gone Girl, The Silent Wife, and Before We Met. However, there was also resistance to the new genre label from critics who viewed it as belittling to women’s writing and to female-focused narratives. Indeed, the separation of female-centred books - whether “chick lit” or “chick noir” - from mainstream fiction remains highly problematic and reflects the persistence of a gendered literary hierarchy. However, as this paper suggests, the label “chick noir” also reflects the fact that in these novels the crime thriller has been revitalized through cross-pollination with the so-called chick lit novel. I contend that chick lit and chick noir are two narrative forms addressing many of the same concerns relating to the modern woman, offering two different responses: humour and horror. Comparing the features of chick noir to those of chick lit and noir crime fiction, I suggest that chick noir may be read as a manifestation of feminist anger and anxiety - responses to the contemporary pressure to be “wonder women.”

  6. Effects of intravitreal insulin and insulin signaling cascade inhibitors on emmetropization in the chick

    Science.gov (United States)

    Penha, Alexandra Marcha; Burkhardt, Eva; Schaeffel, Frank

    2012-01-01

    Purpose Intravitreal insulin has been shown to be a powerful stimulator of myopia in chickens, in particular if the retinal image is degraded or defocused. In most tissues, the insulin receptor activates two main signaling pathways: a) the mitogen-activated protein kinase (MAPK) cascade (e.g., mitogen-activated protein kinasem kinase [MEK] and extracellular regulated kinase [ERK]) and b) the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway. In the current study, insulin was injected, and these pathways were separately inhibited to determine which is activated when the retinal image is defocused by spectacle lenses. Methods Chicks were treated with either +7 D, −7 D, or no lenses. They were intravitreally injected with insulin, the MEK inhibitor U0126, the PI3K inhibitor Ly294002, or a combination of insulin and one of the inhibitors. Refractions and ocular dimension were measured at the beginning and after four days of treatment. The retinal proteins of the chicks were measured with western blots after 2 h and four days of treatment. Incubation occurred with anti-Akt1, anti-Erk1/2, anti-phospho-AktThr308, and anti-phospho-Erk1/2(Thr202/Tyr204) antibodies, and the ratio between the relative intensity of the phospho-form and the total-form was calculated. Results Chicks wearing positive lenses and injected with saline and with PI3K inhibitor compensated for the imposed defocus and became hyperopic. Insulin injections and insulin plus PI3K inhibitor injections prevented lens-induced hyperopia, whereas the MEK inhibitor alone and insulin plus MEK inhibitor had no effect. Obviously, the MEK inhibitor suppressed the effect of insulin on eye growth in the plus lens–treated animals. Chicks treated with negative lenses and injected with insulin, or with insulin plus MEK inhibitor, overcompensated for the imposed defocus. This effect of insulin was not detected in eyes injected with PI3K inhibitor plus insulin, suggesting that the PI3K inhibitor

  7. Mechanism of riboflavin uptake by cultured human retinal pigment epithelial ARPE-19 cells: possible regulation by an intracellular Ca2+-calmodulin-mediated pathway.

    Science.gov (United States)

    Said, Hamid M; Wang, Shuling; Ma, Thomas Y

    2005-07-15

    In mammalian cells (including those of the ocular system), the water-soluble vitamin B2 (riboflavin, RF) assumes an essential role in a variety of metabolic reactions and is critical for normal cellular functions, growth and development. Cells of the human retinal pigment epithelium (hRPE) play an important role in providing a sufficient supply of RF to the retina, but nothing is known about the mechanism of the vitamin uptake by these cells and its regulation. Our aim in the present study was to address this issue using the hRPE ARPE-19 cells as the retinal epithelial model. Our results show RF uptake in the hRPE to be: (1) energy and temperature dependent and occurring without metabolic alteration in the transported substrate, (2) pH but not Na+ dependent, (3) saturable as a function of concentration with an apparent Km of 80 +/- 14 nM, (4) trans-stimulated by unlabelled RF and its structural analogue lumiflavine, (5) cis-inhibited by the RF structural analogues lumiflavine and lumichrome but not by unrelated compounds, and (6) inhibited by the anion transport inhibitors 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) and 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulphonic acid (SITS) as well as by the Na+ -H+ exchange inhibitor amiloride and the sulfhydryl group inhibitor p-chloromercuriphenylsulphonate (p-CMPS). Maintaining the hRPE cells in a RF-deficient medium led to a specific and significant up-regulation in RF uptake which was mediated via changes in the number and affinity of the RF uptake carriers. While modulating the activities of intracellular protein kinase A (PKA)-, protein kinase C (PKC)-, protein tyrosine kinase (PTK)-, and nitric oxide (NO)-mediated pathways were found to have no role in regulating RF uptake, a role for the Ca2+ -calmodulin-mediated pathway was observed. These studies demonstrate for the first time the involvement of a specialized carrier-mediated mechanism for RF uptake by hRPE cells and show that the process is

  8. Production of Retinal Cells from Confluent Human iPS Cells.

    Science.gov (United States)

    Reichman, Sacha; Goureau, Olivier

    2016-01-01

    Human induced pluripotent stem (hiPS) cells could be used as an unlimited source of retinal cells for the treatment of retinal degenerative diseases. Although much progress has been made in the differentiation of pluripotent stem cells towards different retinal lineages, the production of retinal cells from hiPS cells for therapeutic approaches require the development of easy and standardized protocols. In this chapter, we describe a simple and effective protocol for retinal differentiation of hiPS cells bypassing embryoid body formation and the use of exogenous molecules and substrates. In 2 weeks, confluent hiPS cells cultured in pro-neural medium can generate both retinal pigmented epithelial cells and self-forming neural retina-like structures containing retinal progenitor cells. These progenitors can be differentiated into all retinal cell types, including retinal ganglion cells and precursors of photoreceptors, which could find important applications in regenerative medicine. This differentiation system and the resulting hiPS-derived retinal cells will also offer opportunity to study the molecular and cellular mechanisms underlying human retinal development, and the establishment of in vitro models of human retinal degenerative diseases.

  9. Oxygenated drinking water enhances immune activity in broiler chicks and increases survivability against Salmonella Gallinarum in experimentally infected broiler chicks.

    Science.gov (United States)

    Jung, Bock-Gie; Lee, Jin-A; Nam, Kyoung-Woo; Lee, Bong-Joo

    2012-03-01

    It has been suggested that drinking oxygenated water may improve oxygen availability, which may increase vitality and improving immune activity. The present study evaluated the immune enhancing effects of oxygenated drinking water in broiler chicks and demonstrated the protective efficacy of oxygenated drinking water against Salmonella Gallinarum in experimentally infected broiler chicks. Continuous drinking of oxygenated water markedly increased serum lysozyme activity, peripheral blood mononuclear cell proliferation and the CD4(+)/CD8(+) splenocyte ratio in broiler chicks. In the chicks experimentally infected with S. Gallinarum, oxygenated drinking water alleviated symptoms and increased survival. These findings suggest that oxygenated drinking water enhances immune activity in broiler chicks, and increases survivability against S. Gallinarum in experimentally infected broiler chicks.

  10. The formation of premuscle masses during chick wing bud development.

    Science.gov (United States)

    Schramm, C; Solursh, M

    1990-01-01

    The skeletal musculature of chick limb buds is derived from somitic cells that migrate into the somatopleure of the future limb regions. These cells become organized into the earliest muscle primordia, the dorsal and ventral premuscle masses, prior to myogenic differentiation. Therefore, skeletal-muscle specific markers cannot be used to observe myogenic cells during the process of premuscle mass formation. In this study, an alternative marking method was used to determine the specific stages during which this process occurs. Quail somite strips were fluorescently labeled and implanted into chick hosts. Paraffin sections of the resulting chimeric wing buds were stained with the monoclonal antibody QH1 in order to identify graft-derived endothelium. Non-endothelial graft-derived cells present in the wing mesenchyme were assumed to be myogenic. At Hamburger and Hamilton stage 20, myogenic cells were distributed throughout the central region of the limb, including the future dorsal and ventral premuscle mass regions and the prechondrogenic core region. By stage 21, the myogenic cells were present at greater density in dorsal and ventral regions than in the core. By stage 23, nearly all myogenic cells were located in the dorsal and ventral premuscle masses. Therefore, the two premuscle masses become established by stage 21 and premuscle mass formation is not complete until stage 23 or later. Premuscle mass formation occurs concurrently with early chondrogenic events, as observed with the marker peanut agglutinin. To facilitate the investigation of possible underlying mechanisms of premuscle mass formation, the micromass culture system was evaluated, to determine whether or not it can serve as an accurate in vitro model system. The initially randomly distributed myogenic cells were observed to segregate from prechondrogenic regions prior to myogenic differentiation. This is similar to myogenic patterning in vivo.

  11. A novel method for culture of bovine retinal capillary endothelial cells%一种高选择性、高效的牛视网膜微血管内皮细胞培养方法

    Institute of Scientific and Technical Information of China (English)

    王征; 齐炜炜; 陈少波; 戴智育; 陈大伟; 程锐; 高国全; 杨霞

    2012-01-01

    目的 建立一种高效、可行、特异性高的牛视网膜微血管内皮细胞(BREC)培养方法.方法 取新鲜牛眼,分离视网膜并用DMEM进行冲洗、匀浆剪碎,过75μm筛,将滤网上滤渣转移至50 ml离心管,用I型胶原酶、DNaseI及蛋白酶等多种酶混合液消化20 min,人血清中和后,过46μm网筛并冲洗,离心5 min,将组织扣在培养皿中,转入15 ml离心管,用10%人血清含生长因子ECGS的DMEM培养液培养于25 cm2,选择性培养视网膜血管内皮细胞,接种于明胶包被培养瓶中,采用ECGS配合肝素培养液促进内皮细胞生长,观察细胞形状生长特性,并用免疫化学荧光方法进行鉴定.结果 选择性培养视网膜微血管内皮细胞成单层、镶嵌铺路石状生长,Ⅷ因子相关抗原免疫荧光检测为阳性纯度均大于95%以上,将细胞种在凝固的基质胶表面,12~18 h形成官腔结构.结论 本方法过程简单、可靠,培养的内皮细胞纯度高,生长状态良好,稳定传代,为视网膜血管生成疾病研究建立了模型.%Objective To provide an efficient, practicable and high specificity method for culture of bovine retinal capillary endothelial cells (BRCEC). Methods Fresh bovine eyes were obtained from a local market. The retinas were removed and washed several times in DMEM. Subsequently retinas were homogenized and the resultant pellet was resuspended in an isolation medium. Microvesseles were trapped on an 75 ftm nylon mesh and transferred to a 50 ml centrifuge tube containing 10 ml enzyme cocktail which includes collagenase I , Dnase I and pronase and treated for 20 min. The resultant vessel fragments were trapped on a 46 p.m nylon mesh,washed with the isolation medium and centrifuged for 5 min. For selective culture of BRCECs, the resultant pellet was resuspended in 2 ml of the BRCEC growth medium and transferred into 25 cm2 gelatin-coated plastic tissue culture flasks. BRCECs were identified by immunohistochemical method of

  12. Specific inhibition of TRPV4 enhances retinal ganglion cell survival in adult porcine retinal explants.

    Science.gov (United States)

    Taylor, Linnéa; Arnér, Karin; Ghosh, Fredrik

    2017-01-01

    Signaling through the polymodal cation channel Transient Receptor Potential Vanilloid 4 (TRPV4) has been implicated in retinal neuronal degeneration. To further outline the involvement of this channel in this process, we here explore modulation of Transient Receptor Potential Vanilloid 4 (TRPV4) activity on neuronal health and glial activation in an in vitro model of retinal degeneration. For this purpose, adult porcine retinal explants were cultured using a previously established standard protocol for up to 5 days with specific TRPV4 agonist GSK1016790A (GSK), or specific antagonist RN-1734, or culture medium only. Glial and neuronal cell health were evaluated by a battery of immunohistochemical markers, as well as morphological staining. Specific inhibition of TRPV4 by RN-1734 significantly enhanced ganglion cell survival, improved the maintenance of the retinal laminar architecture, reduced apoptotic cell death and attenuated the gliotic response as well as preserved the expression of TRPV4 in the plexiform layers and ganglion cells. In contrast, culture controls, as well as specimens treated with GSK, displayed rapid remodeling and neurodegeneration as well as a downregulation of TRPV4 and the Müller cell homeostatic mediator glutamine synthetase. Our results indicate that TRPV4 signaling is an important contributor to the retinal degeneration in this model, affecting neuronal cell health and glial homeostasis. The finding that pharmacological inhibition of the receptor significantly attenuates neuronal degeneration and gliosis in vitro, suggests that TRPV4 signaling may be an interesting pharmaceutical target to explore for treatment of retinal degenerative disease.

  13. Progressive outer retinal necrosis-like retinitis in immunocompetent hosts.

    Science.gov (United States)

    Chawla, Rohan; Tripathy, Koushik; Gogia, Varun; Venkatesh, Pradeep

    2016-08-10

    We describe two young immunocompetent women presenting with bilateral retinitis with outer retinal necrosis involving posterior pole with centrifugal spread and multifocal lesions simulating progressive outer retinal necrosis (PORN) like retinitis. Serology was negative for HIV and CD4 counts were normal; however, both women were on oral steroids at presentation for suspected autoimmune chorioretinitis. The retinitis in both eyes responded well to oral valaciclovir therapy. However, the eye with the more fulminant involvement developed retinal detachment with a loss of vision. Retinal atrophy was seen in the less involved eye with preservation of vision. Through these cases, we aim to describe a unique evolution of PORN-like retinitis in immunocompetent women, which was probably aggravated by a short-term immunosuppression secondary to oral steroids.

  14. The antioxidant activity of propofol in chicks

    Directory of Open Access Journals (Sweden)

    A.S. Naser

    2015-06-01

    Full Text Available The aim of this study was to detect the antioxidant effects of propofol in chicks by estimation of glutathione concentration in blood plasma, brain and liver as well as total antioxidant capacity and antioxidant effects of propofol in vitro by using hydrogen peroxide as oxidative stress. Propofol at 20 mg/kg, intraperitoneally significantly increased after 4 hours the concentration of glutathione concentration in plasma and brain compared with the control group and with 5 and 10mg propofol groups. Propofol at 5, 10 and 20 mg/kg, i.p significantly increased glutathione concentration in the liver compared with the control group. Propofol at 5, 10 and 20 mg/kg, i.p increased the efflux rate constant by 882, 1031 and 920 %, increased glutathione turnover rate by 880, 1028, and 917 % and decreased the turnover time by 89, 91 and 90% in the liver. In the brain propofol at 5, 10 and 20 mg/kg, i.p increased efflux rate constant as 26, 600 and 2826 % and increased glutathione turnover rate by 29, 616 and 2894 % and a decreased in the turnover time by 21, 86 and 96%. propofol at 10 and 20 mg/kg, i.p significantly increased after 20 hours the TAC in the serum of the chick by 38 and 48%, respectively compared with the control group. Propofol at concentrations of 25, 50 and 100 micromoles / liter decreased erythrocyte hemolysis induced by hydrogen peroxide in vitro 10 micromoles / liter in a concentration depended manner by 25, 49 and 64 % respectively. In conclusion, propofol have antioxidant effect in vivo and in vitro in the chicks.Propofol have a protection against oxidative stress.

  15. Age-Dependent Retinal Iron Accumulation and Degeneration in Hepcidin Knockout Mice

    Science.gov (United States)

    Hadziahmetovic, Majda; Song, Ying; Ponnuru, Padmavathi; Iacovelli, Jared; Hunter, Allan; Haddad, Nadine; Beard, John; Connor, James R.; Vaulont, Sophie

    2011-01-01

    Purpose. Iron dysregulation can cause retinal disease, yet retinal iron regulatory mechanisms are incompletely understood. The peptide hormone hepcidin (Hepc) limits iron uptake from the intestine by triggering degradation of the iron transporter ferroportin (Fpn). Given that Hepc is expressed in the retina and Fpn is expressed in cells constituting the blood-retinal barrier, the authors tested whether the retina may produce Hepc to limit retinal iron import. Methods. Retinas of Hepc−/− mice were analyzed by histology, autofluorescence spectral analysis, atomic absorption spectrophotometry, Perls' iron stain, and immunofluorescence to assess iron-handling proteins. Retinal Hepc mRNA was evaluated through qPCR after intravitreal iron injection. Mechanisms of retinal Hepc upregulation were tested by Western blot analysis. A retinal capillary endothelial cell culture system was used to assess the effect of exogenous Hepc on Fpn. Results. Hepc−/− mice experienced age-dependent increases in retinal iron followed by retinal degeneration with autofluorescent RPE, photoreceptor death, and subretinal neovascularization. Hepc−/− mice had increased Fpn immunoreactivity in vascular endothelial cells. Conversely, in cultured retinal capillary endothelial cells, exogenous Hepc decreased both Fpn levels and iron transport. The retina can sense increased iron levels, upregulating Hepc after phosphorylation of extracellular signal regulated kinases. Conclusions. These findings indicate that Hepc is essential for retinal iron regulation. In the absence of Hepc, retinal degeneration occurs. Increases in Hepc mRNA levels after intravitreal iron injection combined with Hepc-mediated decreases in iron export from cultured retinal capillary endothelial cells suggest that the retina may use Hepc for its tissue-specific iron regulation. PMID:20811044

  16. In vitro differentiation of retinal pigment epithelium from adult retinal stem cells.

    Science.gov (United States)

    Aruta, Claudia; Giordano, Francesca; De Marzo, Anna; Comitato, Antonella; Raposo, Graça; Nandrot, Emeline F; Marigo, Valeria

    2011-02-01

    One of the limitations in molecular and functional studies of the retinal pigment epithelium (RPE) has been the lack of an in vitro system retaining all the features of in vivo RPE cells. Retinal pigment epithelium cell lines do not show characteristics typical of a functional RPE, such as pigmentation and expression of specific markers. The present study was aimed at the development of culture conditions to differentiate, in vitro, retinal stem cells (RSC), derived from the adult ciliary body, into a functional RPE. Retinal stem cells were purified from murine eyes, grown as pigmented neurospheres and induced to differentiate into RPE on an extracellular matrix substrate using specific culture conditions. After 7-15 days of culture, pigmented cells with an epithelial morphology showed a polarized organization and a capacity for phagocytosis. We detected different stages of melanogenesis in cells at 7 days of differentiation, whereas RPE at 15 days contained only mature melanosomes. These data suggest that our protocol to differentiate RPE in vitro can provide a useful model for molecular and functional studies.

  17. Killing day-old chicks? Public opinion regarding potential alternatives

    NARCIS (Netherlands)

    Leenstra, F.; Munnichs, G.M.; Beekman, V.; Vromans, E.; Aramyan, L.; Woelders, H.

    2011-01-01

    Throughout the world, male chicks from layer breeds are killed just after hatching, as they are not profitable as regards the production of meat. The Dutch and European parliaments have insisted on research into possible alternatives to the killing of day-old chicks. In the present study we have inv

  18. Measuring the style of chick lit and literature

    NARCIS (Netherlands)

    Jautze, K.J.

    2014-01-01

    This paper examines to what extent the distribution of the hundred most frequent function words of two novelistic genres (chick lit and literature) gives insight into the genre styles. The results shows that the literary style is more descriptive and informational, whereas the style of the chick-lit

  19. The effect of pirenzepine on positive- and negative-lens-induced refractive error and ocular growth in chicks.

    Science.gov (United States)

    Metlapally, Sangeetha; McBrien, Neville A

    2010-11-01

    The selective muscarinic antagonist pirenzepine inhibits experimentally induced myopia in avian and mammalian species, including nonhuman primates and adolescent humans. Transient positive lens defocus has a potent inhibitory effect on negative-lens-induced myopia in avian and mammalian models. The purpose of the present study was to determine the influence of daily treatment with pirenzepine on ocular growth and refractive error in chicks wearing positive lenses. The chicks were allocated to one of eight groups (n = 6 each group) on the basis of whether they wore +10 or -10 D lenses monocularly and whether they received daily intravitreal injections of pirenzepine (700 μg) or vehicle (phosphate-buffered saline) in the lens-defocused eye. In vivo refractive and biometric data were collected, and glycosaminoglycan synthesis in the sclera was assessed. Pirenzepine did not alter the level of positive-lens-induced hyperopia in chicks wearing +10 D lenses compared with that in the vehicle control group (+8.1 ± 0.6 D vs. +8.9 ± 2.4 D, mean ± SEM; P = 0.76). In contrast, pirenzepine caused significant inhibition of negative-lens-induced myopia compared with that in the vehicle group (-1.1 ± 1.5 D vs. -8.8 ± 1.1 D; P = 0.001). Glycosaminoglycan synthesis in the posterior sclera was significantly increased in the negative-lens-treated groups and showed small decreases in the positive-lens-treated groups. The influence of pirenzepine on ocular growth in chicks differed by sign of lens defocus, with pirenzepine blocking negative-lens effects on ocular growth, but not positive-lens effects. The most likely reason that hyperopia was not enhanced by pirenzepine treatment was that the rapid compensatory eye growth associated with positive lenses eliminated the imposed myopic defocus, and the clear retinal image prevented any additional hyperopia from developing.

  20. Peripheral Insulin Doesn’t Alter Appetite of Broiler Chicks

    Directory of Open Access Journals (Sweden)

    Lei Liu

    2016-09-01

    Full Text Available An experiment was conducted to investigate the effect of peripheral insulin treatment on appetite in chicks. Six-d-age chicks with ad libitum feeding or fasting for 3 h before injection received a subcutaneous injection of 0, 1, 3, 5, 10, or 20 IU of insulin or vehicle (saline. The results showed peripheral insulin treatment (1 to 20 IU did not alter significantly the feed intake in chicks under either ad libitum feeding or fasting conditions within 4 h (p>0.05. Compared with the control, plasma glucose concentration was significantly decreased after insulin treatment of 3, 5, 10, and 20 IU for 4 h in chicks with ad libitum feeding (p0.05. All results suggest peripheral administration of insulin has no effect on appetite in chicks.

  1. Down regulation of pRb in cultures of avian neuroretina cells promotes proliferation of reactive Müller-like cells and emergence of retinal stem/progenitors.

    Science.gov (United States)

    Marx, Maria; Lebuhotel, Céline; Laugier, Danielle; Chapelle, Audrey; Calothy, Georges; Saule, Simon

    2010-06-01

    The aim of this work was to define the role of pRb depletion in the proliferation and differentiation of avian retinoblasts in vitro. For this purpose vectors expressing pRb short hairpin RNA were used to deplete pRb in cultures of avian neuroretinal cells. Down regulation of pRb was observed by Western blot and quantification of nuclear pRb. Cell proliferation and differentiation were studied following BrdU labeling and immunostaining. Transfection significantly down-regulated pRb in neuroretinal cells. Long-term effect of pRb depletion mainly induced proliferation of epithelial-like cells that expressed markers of reactive Müller glial cells. A minority of these cells that survived passaging could be maintained as neurosphere-like aggregates with low pRb, not observed in control cultures. BrdU labeling followed by a two week chase showed the presence of cells still remained labelled, indicating low cell cycling. Under appropriate conditions, these aggregates differentiate in precursors of amacrine interneurons shown by the expression of AP2, in absence of the photoreceptors marker visinin and the late neuronal marker MAP2. Taken together these data show that decrease pRb level in cultures of avian neuroretinal cells promotes the emergence and proliferation of stem cell/progenitors from reactive-like Muller cells.

  2. Expression of glial cell line-derived neurotrophic factor and its receptors in cultured retinal Müller cells under high glucose circumstance.

    Science.gov (United States)

    Zhu, Xinping; Sun, Yan; Wang, Zhongping; Cui, Weigang; Peng, Yuwen; Li, Ruixi

    2012-03-01

    This study aimed to explore the effect of high glucose concentration on the expression of glial cell line-derived neurotrophic factor (GDNF) and its family ligand receptors (GFRs) GFRα1 and GFRα2 in Müller cells and the protective role of GDNF in cultured Müller cells under high glucose circumstance. Cultured Müller cells (untreated or treated with 200 ng/mL of GDNF) were exposed to high glucose conditions (20 mmol/L glucose). We found that the expression levels of GDNF and GFRα1 mRNA and protein increased gradually over time under high glucose and exogenous GDNF-treated conditions, whereas the upregulation in GFRα2 expression was observed only in the early stage of high glucose conditions. Exogenous GDNF not only decreased apoptosis in cultured Müller cells under high glucose circumstance, but also accelerated the levels and speed of synthesis of GDNF and GFRα1 proteins in Müller cells. These results suggest that Müller cells can synthesize GDNF and GFRs under high glucose conditions, and GDNF may play important role in protecting Müller cells during the early stage of diabetic retinopathy. The difference in GFRs expression indicated that GDNF and neurturin may exert different effects on Müller cells under high glucose circumstance.

  3. Neural basis of imprinting behavior in chicks.

    Science.gov (United States)

    Nakamori, Tomoharu; Maekawa, Fumihiko; Sato, Katsushige; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

    2013-01-01

    Newly hatched chicks memorize the characteristics of the first moving object they encounter, and subsequently show a preference for it. This "imprinting" behavior is an example of infant learning and is elicited by visual and/or auditory cues. Visual information of imprinting stimuli in chicks is first processed in the visual Wulst (VW), a telencephalic area corresponding to the mammalian visual cortex, congregates in the core region of the hyperpallium densocellulare (HDCo) cells, and transmitted to the intermediate medial mesopallium (IMM), a region similar to the mammalian association cortex. The imprinting memory is stored in the IMM, and activities of IMM neurons are altered by imprinting. Imprinting also induces functional and structural plastic changes of neurons in the circuit that links the VW and the IMM. Of these neurons, the activity of the HDCo cells is strongly influenced by imprinting. Expression and modulation of NR2B subunit-containing N-methyl-D-aspartate (NMDA) receptors in the HDCo cells are crucial for plastic changes in this circuit as well as the process of visual imprinting. Thus, elucidation of cellular and molecular mechanisms underlying the plastic changes that occurred in the HDCo cells may provide useful knowledge about infant learning. © 2012 The Authors Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

  4. Retinal Detachment in Preeclampsia

    Directory of Open Access Journals (Sweden)

    Prado Renata Silva do

    2002-01-01

    Full Text Available Preeclampsia is an obstetric disease of unknown cause that affects approximately 5% of pregnant women. The visual system may be affected with variable intensity, being the retinal detachment a rare complication. The retinal detachment in preeclampsia is usually bilateral and serous, and its pathogenesis is related to the choroidal ischemia secondary to an intense arteriolar vasospasm. The majority of patients have complete recovery of vision with clinical management, and surgery is unnecessary. This is a case report of a 27 year old patient who developed the severe form of preeclampsia on her first pregnancy. She had progressive blurred vision, until she could see only shadows. Ophthalmic examination diagnosed spread and bilateral retinal detachment. With blood pressure control at postpartum, the patient had her retina reattached, and recovery of vision.

  5. Probabilistic retinal vessel segmentation

    Science.gov (United States)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  6. Bioelectronic retinal prosthesis

    Science.gov (United States)

    Weiland, James D.

    2016-05-01

    Retinal prosthesis have been translated to clinical use over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa and one device is in clinical trials for treatment of age-related macular degeneration. These devices provide partial sight restoration and patients use this improved vision in their everyday lives to navigate and to detect large objects. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. In particular, current retinal prostheses do not provide peripheral visions due to technical and surgical limitations, thus limiting the effectiveness of the treatment. This paper reviews recent results from human implant patients and presents technical approaches for peripheral vision.

  7. Effects of L-glutamate/D-aspartate and monensin on lactic acid production in retina and cultured retinal Müller cells

    OpenAIRE

    Winkler, Barry S.; Sauer, Michael W.; Starnes, Catherine A.

    2004-01-01

    We have investigated the dependence of the rate of lactic acid production on the rate of Na+ entry in cultured transformed rat Müller cells and in normal and dystrophic (RCS) rat retinas that lack photoreceptors. To modulate the rate of Na+ entry, two approaches were employed: (i) the addition of L-glutamate (D-aspartate) to stimulate coupled uptake of Na+ and the amino acid; and (ii) the addition of monensin to enhance Na+ exchange. Müller cells produced lactate aerobically and anaerobically...

  8. From the Cover: Exposing Imidacloprid Interferes With Neurogenesis Through Impacting on Chick Neural Tube Cell Survival.

    Science.gov (United States)

    Liu, Meng; Wang, Guang; Zhang, Shi-Yao; Zhong, Shan; Qi, Guo-Long; Wang, Chao-Jie; Chuai, Manli; Lee, Kenneth Ka Ho; Lu, Da-Xiang; Yang, Xuesong

    2016-09-01

    As a neonicotinoid pesticide, imidacloprid is widely used to control insects in agriculture and fleas on domestic animals. However, it is not known whether imidacloprid exposure negatively affects neurogenesis during embryonic development. In this study, using a chick embryo model, we investigated the effects of imidacloprid exposure on neurogenesis at the earliest stage and during late-stage embryo development. Exposing HH0 chick embryos to imidacloprid in EC culture caused neural tube defects (NTDs) and neuronal differentiation dysplasia as determined by NF/Tuj1 labeling. Furthermore, we found that F-actin accumulation on the apical side of the neural tube was suppressed by exposure to imidacloprid, and the expression of BMP4 and Shh on the dorsal and ventral sides of the neural tubes, respectively, were also reduced, which in turn affects the dorsolateral hinge points during bending of the neural plate. In addition, exposure to imidacloprid reduced cell proliferation and increased cell apoptosis, as determined by pHIS3 labeling and TUNEL staining, respectively, also contributing to the malformation. We obtained similar results in late-stage embryos exposed to imidacloprid. Finally, a bioinformatics analysis was employed to determine which genes identified in this study were involved in NTDs. The experimental evidence and bioinformatics analysis suggested that imidacloprid exposure during chick embryo development could increase the risk of NTDs and neural dysplasia.

  9. Maternal Antibody Protected Chicks from Growth Retardation and Immunosuppression Induced by Early Reticuloendotheliosis Virus Infection

    Institute of Scientific and Technical Information of China (English)

    SUN Shu-hong; GUI Zhi-zhong; QU Li-xin

    2007-01-01

    To determine if the maternal antibody from breeders vaccinated with cell culture-adapted reticuloendotheliosis virus (REV) could protect chicks from early REV infection, one-day-old chicks with or without anti-REV maternal antibodies were inoculated with REV, and then their growth rates and antibody tilers to Newcastle disease virus (NDV) and avian influenza virus (AIV), after vaccination with inactivated vaccines, were compared. This study indicated that REV infection could cause growth retardation and severely inhibit immune reactions to inactivated vaccines against NDV and Avian influenza virus (AIV, H9 and H5) in one-day-old broilers without maternal antibodies specific to REV. Maternal antibody from breeders vaccinated with an attenuated REV vaccine effectively protected REV-challenged birds from growth retardation and immunosuppression on antibody reactions to NDV and AIV vaccines. Four weeks after vaccination, the HI liters to NDV, AIV-H9, and AIV-H5 in maternal antibody positive and negative groups were 3.36±2.04 versus 1.58±1.69 (P<0.01), 6.27±3.87 versus 0.71±1.60(P<0.01), and 6.72 versus 0.54±1.44(p<0.01). Maternal antibodies from breeders vaccinated with REV vaccine could successfully protect chicks from REV infection and effectively prevent REV-induced growth retardation and immunosuppression in antibody responses to NDV and AIV.

  10. Retinal flow cytometer.

    Science.gov (United States)

    Alt, C; Veilleux, I; Lee, H; Pitsillides, C M; Côté, D; Lin, C P

    2007-12-01

    The in vivo flow cytometer is an instrument capable of continuous, real-time monitoring of fluorescently labeled cells in the circulation without the need to draw blood samples. However, the original system probes a single vessel in the mouse ear; the small sample volume limits the sensitivity of the technique. We describe an in vivo retinal flow cytometer that simultaneously probes five artery-vein pairs in the mouse eye by circularly scanning a small laser spot rapidly around the optic nerve head. We demonstrate that the retinal flow cytometer detects about five times more cells per minute than the original in vivo flow cytometer does in the ear.

  11. [Retinal pneumopexy in the treatment of rhegmatogenous retinal detachment].

    Science.gov (United States)

    Levai, L; Gavriş, Monica; Gábor, Radó; Bagosi, P

    2014-01-01

    To evaluate the efficiency of retinal pneumopexy in patients with rhegmatogenous retinal detachment. This clinical prospective study unrolled between november 2010-june 2012 in the Ophthalmology Department of the Military Hospital in Cluj-Napoca and Satu Mare Emergency Hospital included 20 patients (20 eyes) with rhegmatogenous retinal detachment. Patients were treated with retinal pneumopexy followed by laser photocoagulation. Anatomical and functional results were evaluated 1, 3, 6, 12 and 19 months after treatment. In 17 eyes out of 20, we achieved retinal reattachment and visual recovery. Three cases yelded no success, these being further treated with posterior vitrectomy. Retinal pneumopexy is a minimally invasive treatment method of rhegmatogenous retinal detachment with very good results in well selected cases.

  12. Retinal stem cells and regeneration of vision system.

    Science.gov (United States)

    Yip, Henry K

    2014-01-01

    The vertebrate retina is a well-characterized model for studying neurogenesis. Retinal neurons and glia are generated in a conserved order from a pool of mutlipotent progenitor cells. During retinal development, retinal stem/progenitor cells (RPC) change their competency over time under the influence of intrinsic (such as transcriptional factors) and extrinsic factors (such as growth factors). In this review, we summarize the roles of these factors, together with the understanding of the signaling pathways that regulate eye development. The information about the interactions between intrinsic and extrinsic factors for retinal cell fate specification is useful to regenerate specific retinal neurons from RPCs. Recent studies have identified RPCs in the retina, which may have important implications in health and disease. Despite the recent advances in stem cell biology, our understanding of many aspects of RPCs in the eye remains limited. PRCs are present in the developing eye of all vertebrates and remain active in lower vertebrates throughout life. In mammals, however, PRCs are quiescent and exhibit very little activity and thus have low capacity for retinal regeneration. A number of different cellular sources of RPCs have been identified in the vertebrate retina. These include PRCs at the retinal margin, pigmented cells in the ciliary body, iris, and retinal pigment epithelium, and Müller cells within the retina. Because PRCs can be isolated and expanded from immature and mature eyes, it is possible now to study these cells in culture and after transplantation in the degenerated retinal tissue. We also examine current knowledge of intrinsic RPCs, and human embryonic stems and induced pluripotent stem cells as potential sources for cell transplant therapy to regenerate the diseased retina.

  13. Retinal locus for scanning text.

    Science.gov (United States)

    Timberlake, George T; Sharma, Manoj K; Grose, Susan A; Maino, Joseph H

    2006-01-01

    A method of mapping the retinal location of text during reading is described in which text position is plotted cumulatively on scanning laser ophthalmoscope retinal images. Retinal locations that contain text most often are the brightest in the cumulative plot, and locations that contain text least often are the darkest. In this way, the retinal area that most often contains text is determined. Text maps were plotted for eight control subjects without vision loss and eight subjects with central scotomas from macular degeneration. Control subjects' text maps showed that the fovea contained text most often. Text maps of five of the subjects with scotomas showed that they used the same peripheral retinal area to scan text and fixate. Text maps of the other three subjects with scotomas showed that they used separate areas to scan text and fixate. Retinal text maps may help evaluate rehabilitative strategies for training individuals with central scotomas to use a particular retinal area to scan text.

  14. Effect of atrophy and contractions on myogenin mRNA concentration in chick and rat myoblast omega muscle cells

    Science.gov (United States)

    Krebs, J. M.; Denney, R. M.

    1997-01-01

    The skeletal rat myoblast omega (RMo) cell line forms myotubes that exhibit spontaneous contractions under appropriate conditions in culture. We examined if the RMo cells would provide a model for studying atrophy and muscle contraction. To better understand how to obtain contractile cultures, we examined levels of contraction under different growing conditions. The proliferation medium and density of plating affected the subsequent proportion of spontaneously contracting myotubes. Using a ribonuclease protection assay, we found that exponentially growing RMo myoblasts contained no detectable myogenin or herculin mRNA, while differentiating myoblasts contained high levels of myogenin mRNA but no herculin mRNA. There was no increase in myogenin mRNA concentration in either primary chick or RMo myotubes whose contractions were inhibited by depolarizing concentrations of potassium (K+). Thus, altered myogenin mRNA concentrations are not involved in atrophy of chick myotubes. Depolarizing concentrations of potassium inhibited spontaneous contractions in both RMo cultures and primary chick myotube cultures. However, we found that the myosin concentration of 6-d-old contracting RMo cells fed medium plus AraC was 11 +/- 3 micrograms myosin/microgram DNA, not significantly different from 12 +/- 4 micrograms myosin/microgram DNA (n = 3), the myosin concentration of noncontracting RMo cells (treated with 12 mM K+ for 6 d). Resolving how RMo cells maintained their myosin content when contraction is inhibited may be important for understanding atrophy.

  15. Learning about Retinitis Pigmentosa

    Science.gov (United States)

    ... that detect light). Photoreceptor cells capture and process light helping us to see. As these cells breakdown and die, patients experience progressive vision loss. The most common feature of all forms of RP is a ... cells that detect dim light) and cones (retinal cells that detect light and ...

  16. Nanomaterials and Retinal Toxicity

    Science.gov (United States)

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  17. Retinal vein occlusion

    Science.gov (United States)

    ... decrease the risk of retinal vein occlusion. These measures include: Eating a low-fat diet Getting regular exercise Maintaining an ideal weight Not smoking Aspirin or other blood thinners may help prevent blockages in the other eye. Controlling diabetes may ...

  18. Retinal imaging with smartphone.

    Science.gov (United States)

    Ademola-Popoola, D S; Olatunji, V A

    2017-03-01

    The use of smartphones for various purposes among health professionals is increasing, especially with the availability of different applications. On account of cost, fundus cameras are not readily available in ophthalmic practice in developing countries. Since smartphones are readily available, easy to use and portable, they may present a cheap alternative in a resource-limited economy. to explore the use of smartphone (Blackberry Z-10) for retinal imaging in a resource-limited economy. A smartphone (Blackberry Z-10) was used to acquire retinal images with the use of +20D lens in patients with dilated pupils by activating the video mode of the camera. Clear retinal images were obtained in different clinical conditions in adults and children including branch retinal vein occlusion with fibrovascular proliferation, chorioretinal scarring from laser photocoagulation, presumed ocular toxoplasmosis, diabetic retinopathy, retinoblastoma, ocular albinism with fundus hypopigmentation. The ability to have low cost fundus imaging from readily available smartphones in an eye clinic in Nigeria presents a major boost to patient care and also offers an innovative role in research, education, and information sharing.

  19. Nanomaterials and Retinal Toxicity

    Science.gov (United States)

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  20. Retinal Imaging with Smartphone

    African Journals Online (AJOL)

    2017-03-06

    Mar 6, 2017 ... Aim and Objectives: to explore the use of smartphone (Blackberry. Z-10) for retinal imaging in ... Samsung phones with additional apps/software such as the Filmic pro to ... in Nigeria also compared the iPhone with the Android.

  1. The chick embryo chorioallantoic membrane (CAM) assay.

    Science.gov (United States)

    Ribatti, Domenico

    2017-06-01

    During avian development the mesodermal layers of the allantois and chorion fuse to form the chorioallantoic membrane (CAM). This structure rapidly expands generating a rich vascular network that provides an interface for gas and waste exchange. The CAM allows to study tissue grafts, tumor growth and metastasis, drugs delivery and toxicologic analysis, and angiogenic and anti-angiogenic molecules. The CAM is relatively simple, quick, and low-cost model that allows screening of a large number of pharmacological samples in a short time; does not require administrative procedures for obtaining ethics committee approval for animal experimentation. Moreover, being naturally immunodeficient, the chick embryo may receive transplantations from different tissues and species, without immune responses. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Duration of rhegmatogenous retinal detachment predicts recovery of retinal sensitivity

    Directory of Open Access Journals (Sweden)

    Rose Rose

    2016-02-01

    Full Text Available The decision to treat a disease is often based on the presence or absence of symptoms, one prototype case being rhegmatogenous retinal detachment. Detachment of the neural retina from the pigment epithelium is a major cause of anatomical and functional dysfunction of the retina, where retinal recovery is inversely related to duration of detachment. The purpose of retinal reattachment is to effect recovery of the photoreceptors and pigment epithelium from degeneration. The aim of this study was to determine the critical duration of rhegmatogenous retinal detachment resulting in optimal retinal recovery after reattachment. A prospective study was conducted at a private hospital in Yogyakarta. Thirty five eyes were involved in this study. Three months after reattachment, central retinal recovery was measured by means of a Goldmann manual kinetic perimeter. The results showed that retinal recovery developed three months after surgery if the onset of rhegmatogenous retinal detachment was less than 28 days before surgery. The results were not significant if the onset of rhegmatogenous retinal detachment was more than 35 days. Although the Goldmann manual kinetic perimeter can efficiently detect central retinal sensitivity, it should be supported by more sensitive tools to evaluate the anatomy and function of the retina.

  3. Protection of retinal function by sulforaphane following retinal ischemic injury.

    Science.gov (United States)

    Ambrecht, Lindsay A; Perlman, Jay I; McDonnell, James F; Zhai, Yougang; Qiao, Liang; Bu, Ping

    2015-09-01

    Sulforaphane, a precursor of glucosinolate in cruciferous vegetables such as broccoli and cauliflower, has been shown to protect brain ischemic injury. In this study, we examined the effect of systemic administration of sulforaphane on retinal ischemic reperfusion injury. Intraocular pressure was elevated in two groups of C57BL/6 mice (n = 8 per group) for 45 min to induce retinal ischemic reperfusion injury. Following retinal ischemic reperfusion injury, vehicle (1% DMSO saline) or sulforaphane (25 mg/kg/day) was administered intraperitoneally daily for 5 days. Scotopic electroretinography (ERG) was used to quantify retinal function prior to and one-week after retinal ischemic insult. Retinal morphology was examined one week after ischemic insult. Following ischemic reperfusion injury, ERG a- and b-wave amplitudes were significantly reduced in the control mice. Sulforaphane treatment significantly attenuated ischemic-induced loss of retinal function as compared to vehicle treated mice. In vehicle treated mice, ischemic reperfusion injury produced marked thinning of the inner retinal layers, but the thinning of the inner retinal layers appeared significantly less with sulforaphane treatment. Thus, sulforaphane may be beneficial in the treatment of retinal disorders with ischemic reperfusion injury. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Progressive retinal nonperfusion in ischemic central retinal vein occlusion.

    Science.gov (United States)

    Wykoff, Charles C; Brown, David M; Croft, Daniel E; Major, James C; Wong, Tien P

    2015-01-01

    Serial wide-field fluorescein angiography was performed on eyes with preproliferative (ischemic) central retinal vein occlusion to evaluate retinal perfusion. Serial wide-field fluorescein angiography was performed on 12 preproliferative central retinal vein occlusion eyes in the 3-year Rubeosis Anti-VEGF (RAVE) trial using the Staurenghi lens (Ocular Staurenghi 230SLO Retina Lens) with a scanning laser ophthalmoscope (Heidelberg HRA Spectralis). "Disk area" was defined anatomically for each eye. Mean total field of gradable retina was 290 disk areas (range, 178-452). All eyes demonstrated extensive areas of retinal nonperfusion; at baseline, mean area of retinal perfusion was 106 disk areas (range, 37-129), correlating with a mean of 46.5% perfused retinal area (range, 19.1-56.4%). The area of retinal nonperfusion increased in all eyes with a mean loss of approximately 8.1% of perfused retinal area per year (range, 4.3-12.4%), which corresponded to a mean 15-disk areas (range, 12-35) of retina evolving from perfused to nonperfused annually. The extent of baseline and final nonperfusion was not significantly different between eyes that developed neovascularization and eyes that did not. In this population of severe central retinal vein occlusion eyes, profound retinal nonperfusion was observed with wide-field fluorescein angiography at baseline and the extent of nonperfusion progressed while undergoing anti-vascular endothelial growth factor therapy.

  5. Chick embryo proliferation studies using EdU labeling.

    Science.gov (United States)

    Warren, Michelle; Puskarczyk, Karolina; Chapman, Susan C

    2009-04-01

    Cell proliferation studies are an important experimental tool. The most commonly used thymidine analogues, tritiated thymidine and bromodeoxyuridine (BrdU) label cells during S-phase. Both methods have significant drawbacks: low sensitivity in the case of tritiated thymidine and a denaturation step during BrdU detection that destroys most cellular epitopes, requiring careful optimization. The antibody against BrdU is also large and tissue penetration can be difficult. EdU (5'-ethynyl-2'-deoxyuridine) is closely chemically related to BrdU, with detection achieved by a copper catalyzed reaction requiring a small fluorescently conjugated azide. Cell cultures, flow cytometry and high throughput studies using EdU-labeled cells is exceptionally fast and does not require denaturation or antibodies. We have developed a tissue-labeling technique in chick embryos using EdU. Following EdU chemistry to detect proliferating cells, the tissue can undergo immunolabeling. We demonstrate fluorescent EdU chemistry followed by Tuj1 antibody staining resulting in multiplex fluorescent tissues.

  6. Taurine Provides Neuroprotection against Retinal Ganglion Cell Degeneration

    Science.gov (United States)

    Froger, Nicolas; Cadetti, Lucia; Lorach, Henri; Martins, Joao; Bemelmans, Alexis-Pierre; Dubus, Elisabeth; Degardin, Julie; Pain, Dorothée; Forster, Valérie; Chicaud, Laurent; Ivkovic, Ivana; Simonutti, Manuel; Fouquet, Stéphane; Jammoul, Firas; Léveillard, Thierry; Benosman, Ryad; Sahel, José-Alain; Picaud, Serge

    2012-01-01

    Retinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion) and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats). After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%), whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM) partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases. PMID:23115615

  7. Taurine provides neuroprotection against retinal ganglion cell degeneration.

    Directory of Open Access Journals (Sweden)

    Nicolas Froger

    Full Text Available Retinal ganglion cell (RGC degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats. After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%, whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases.

  8. Taurine provides neuroprotection against retinal ganglion cell degeneration.

    Science.gov (United States)

    Froger, Nicolas; Cadetti, Lucia; Lorach, Henri; Martins, Joao; Bemelmans, Alexis-Pierre; Dubus, Elisabeth; Degardin, Julie; Pain, Dorothée; Forster, Valérie; Chicaud, Laurent; Ivkovic, Ivana; Simonutti, Manuel; Fouquet, Stéphane; Jammoul, Firas; Léveillard, Thierry; Benosman, Ryad; Sahel, José-Alain; Picaud, Serge

    2012-01-01

    Retinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion) and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats). After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%), whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM) partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases.

  9. Peripapillary retinal thermal coagulation following electrical injury

    Directory of Open Access Journals (Sweden)

    Manjari Tandon

    2013-01-01

    Full Text Available In this study, we have presented the case report of a 20 year old boy who suffered an electric injury shock, following which he showed peripapillary retinal opacification and increased retinal thickening that subsequently progressed to retinal atrophy. The fluorescein angiogram revealed normal retinal circulation, thus indicating thermal damage to retina without any compromise to retinal circulation.

  10. Effects of heat stress on day-old broiler chicks.

    Science.gov (United States)

    Ernst, R A; Weathers, W W; Smith, J

    1984-09-01

    Short-term heat stress can occur when chicks are transported from the hatchery to growing facilities. Two experiments were conducted to determine the possible effects of short-term heat stress on growth and feed conversion of broiler (Hubbard X Hubbard) chicks. The heat stress was accomplished by placing chicks in Jamesway 252 incubators at dry bulb temperatures ranging from 40 to 45 C for variable times. Growth, feed consumption, and mortality were measured for 16 days following the heat stress. Short sublethal heat stress significantly reduced growth rate to 16 days in these experiments without any effect on feed conversion ratio. The results indicate that the hatchery industry should avoid overheating chicks even for periods as short as 1 hr.

  11. Effect of refuge supplement on Audouin's gull chick survival

    Directory of Open Access Journals (Sweden)

    Jordi Prieto

    2003-07-01

    Full Text Available One of the main threats to Audouin´s gull (Larus audouinii at Chafarinas Islands is predation on eggs and chicks by the yellow-legged gull (Larus cachinnans. During the 1999 and 2000 breeding seasons we tested the effects of supplementary refuge availability on chick survival. Well before the laying period, nine adjacent enclosures were erected inside Audouin´s gull´s breeding grounds and some of them were supplied with artificial refuges. Our results showed significantly greater chick survival in the enclosures with artificial refuges than in control ones. In 2000, an overall lower breeding success of Audouin´s gull and a dilution of the refuge effect were observed. These results were probably related to food-shortage that year. We suggest that, along with other factors, an increase in refuge availability may significantly enhance Audouin´s gull chick survival.

  12. OCT as a convenient tool to assess the quality and application of organotypic retinal samples

    Science.gov (United States)

    Gater, Rachel; Khoshnaw, Nicholas; Nguyen, Dan; El Haj, Alicia J.; Yang, Ying

    2016-03-01

    Eye diseases such as macular degeneration and glaucoma have profound consequences on the quality of human life. Without treatment, these diseases can lead to loss of sight. To develop better treatments for retinal diseases, including cell therapies and drug intervention, establishment of an efficient and reproducible 3D native retinal tissue system, enabled over a prolonged culture duration, will be valuable. The retina is a complex tissue, consisting of ten layers with a different density and cellular composition to each. Uniquely, as a light transmitting tissue, retinal refraction of light differs among the layers, forming a good basis to use optical coherence tomography (OCT) in assessing the layered structure of the retina and its change during the culture and treatments. In this study, we develop a new methodology to generate retinal organotypic tissues and compare two substrates: filter paper and collagen hydrogel, to culture the organotypic tissue. Freshly slaughtered pig eyes have been obtained for use in this study. The layered morphology of intact organotypic retinal tissue cultured on two different substrates has been examined by spectral domain OCT. The viability of the tissues has been examined by live/dead fluorescence dye kit to cross validate the OCT images. For the first time, it is demonstrated that the use of a collagen hydrogel supports the viability of retinal organotypic tissue, capable of prolonged culture up to 2 weeks. OCT is a convenient tool for appraising the quality and application of organotypic retinal samples and is important in the development of current organotypic models.

  13. Citicoline and Retinal Ganglion Cells: Effects on Morphology and Function.

    Science.gov (United States)

    Parisi, Vincenzo; Oddone, Francesco; Ziccardi, Lucia; Roberti, Gloria; Coppola, Gianluca; Manni, Gianluca

    2017-07-03

    Retinal ganglion cells (RGCs) are the nervous retinal elements that connect the visual receptors to the brain forming the nervous visual system. Functional and/or morphological involvement of RGCs occurs in several ocular and neurological disorders and therefore these cells are targeted in neuroprotective strategies. Cytidine 5-diphosphocholine or Citicoline is an endogenous compound that acts in the biosynthesis of phospholipids of cell membranes and increases neurotransmitters' levels in the Central Nervous System. Experimental studies suggested the neuromodulator effect and the protective role of Citicoline on RGCs. In particular, in rodent retinal cultures and animal models Citicoline induces antiapoptotic effects, increases the dopamine retinal level and counteracts retinal nerve fibers layer thinning. Human studies in neurodegenerative visual pathologies such as glaucoma or non-arteritic ischemic neuropathy showed a reduction of the RGCs impairment after Citicoline administration. By reducing the RGCs' dysfunction, a better neural conduction along the post-retinal visual pathways with an improvement of the visual field defects was observed. Therefore, actually Citicoline, with a solid history of experimental and clinical studies, may be considered a very promising molecule for neuroprotective strategies. In this review, we will present the current evidences on the effects of Citicoline in experimental or human models of neurodegenerative disorders involving the RGCs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Predicting chick body mass by artificial intelligence-based models

    Directory of Open Access Journals (Sweden)

    Patricia Ferreira Ponciano Ferraz

    2014-07-01

    Full Text Available The objective of this work was to develop, validate, and compare 190 artificial intelligence-based models for predicting the body mass of chicks from 2 to 21 days of age subjected to different duration and intensities of thermal challenge. The experiment was conducted inside four climate-controlled wind tunnels using 210 chicks. A database containing 840 datasets (from 2 to 21-day-old chicks - with the variables dry-bulb air temperature, duration of thermal stress (days, chick age (days, and the daily body mass of chicks - was used for network training, validation, and tests of models based on artificial neural networks (ANNs and neuro-fuzzy networks (NFNs. The ANNs were most accurate in predicting the body mass of chicks from 2 to 21 days of age after they were subjected to the input variables, and they showed an R² of 0.9993 and a standard error of 4.62 g. The ANNs enable the simulation of different scenarios, which can assist in managerial decision-making, and they can be embedded in the heating control systems.

  15. Salmonella spp. infection in imported 1-day-old chicks, ducklings, and turkey poults: a public health risk.

    Science.gov (United States)

    Osman, Kamelia M; Yousef, Ashgan M M; Aly, Mona M; Radwan, Moustafa I

    2010-04-01

    The occurrence of Salmonella in 750 birds was assessed. The samples included the internal organs (caecal pouches, yolk sac, liver, and lung) of imported 1-day-old chicks (n = 150), grandparent chicks (n = 150), breeder chicks (n = 150), ducklings (n = 150), and turkey poults (n = 150), and paper-lined boxes (n = 250). Salmonellae isolated from the internal organs and paper-lined box of 1-day-old chicks, ducklings, and poults were mostly evident from the paper-lined box followed by caecal samples. Imported 1-day-old grandparent flocks were Salmonella free. Although 23.3% of the imported breeder flocks were positive for Salmonella, the imported duckling flocks and day-old turkey poults exhibited 19.3% and 12.6%, respectively. The widest diversity in isolated salmonellae was from the 1-day-old chicks where Salmonella Newport, Salmonella Kentucky, Salmonella Enteritidis, Salmonella Shubra, Salmonella Saintpaul, and Salmonella Agona were isolated. On the other hand, two Salmonella serovars were isolated from the imported breeders, Salmonella Shubra and Salmonella Shipley, and from the imported ducklings, Salmonella Shubra and Salmonella Saintpaul. The three Salmonella serovars isolated from the imported day-old turkey poults were Salmonella Shubra, Salmonella Newport, and Salmonella Saintpaul. The high percentage and diversity of Salmonella isolation from the imported birds cause concern because of the zoonotic potential of this agent and its economical importance to the local commercial poultry breeding industry. From 80 samples investigated for Salmonella, the positivity of the standard microbiological technique method was 17.5% and of the polymerase chain reaction method (Salmonella-specific invA gene) was 22.5%. The concordance between the two methods was 90% (k = 0.850). Our results indicated that the polymerase chain reaction approach is better than culturing for detecting Salmonella in poultry samples when using the preenriched medium combinations used in this

  16. Retinal flow cytometer

    OpenAIRE

    Alt, C.; Veilleux, I.; H. Lee; Pitsillides, C. M.; Côté, D.; Lin, C.P.

    2007-01-01

    The in vivo flow cytometer is an instrument capable of continuous, real-time monitoring of fluorescently labeled cells in the circulation without the need to draw blood samples. However, the original system probes a single vessel in the mouse ear; the small sample volume limits the sensitivity of the technique. We describe an in vivo retinal flow cytometer that simultaneously probes five artery–vein pairs in the mouse eye by circularly scanning a small laser spot rapidly around the optic nerv...

  17. Inherited Retinal Degenerative Disease Registry

    Science.gov (United States)

    2016-03-21

    Eye Diseases Hereditary; Retinal Disease; Achromatopsia; Bardet-Biedl Syndrome; Bassen-Kornzweig Syndrome; Batten Disease; Best Disease; Choroidal Dystrophy; Choroideremia; Cone Dystrophy; Cone-Rod Dystrophy; Congenital Stationary Night Blindness; Enhanced S-Cone Syndrome; Fundus Albipunctatus; Goldmann-Favre Syndrome; Gyrate Atrophy; Juvenile Macular Degeneration; Kearns-Sayre Syndrome; Leber Congenital Amaurosis; Refsum Syndrome; Retinitis Pigmentosa; Retinitis Punctata Albescens; Retinoschisis; Rod-Cone Dystrophy; Rod Dystrophy; Rod Monochromacy; Stargardt Disease; Usher Syndrome

  18. The Pinay as Fun, Fearless Female: Philippine Chick Literature in the Age of the Transnation

    Directory of Open Access Journals (Sweden)

    Katrina Stuart Santiago

    2009-12-01

    Full Text Available The paper analyzes Philippine chick literature by Summit Publishing – the first to come out with local chick literature via the Summit Books – and as a by-product of its magazine Cosmopolitan Philippines.This study delves into chick lit’s existence given these context(s: 1. the dynamics of publication in this country, i.e., the “literary” versus the “popular”, works in English versus works in Filipino, the “artsy” versus the bestseller; 2. the various kinds of feminism(s of which the middle class Filipina of today is necessarily part; and 3. the facts of globalization and the transnation that are the bases of the Summit Books’ existence, given its links to Cosmopolitan Philippines, and the latter’s existence as a local franchise of a transnational magazine. This paper also looks at the marginalization and suppression that is contingent upon these perspectives of the Summit Books with a view of seeing the possibilities of resistance and rebellion within them. This project uses as backbone contemporary third world feminist and current Philippine cultural theories that insist on the urgent tasks of relevance and involvement that all contemporary cultural productions by women must face. More particularly, this study uses notions of subjectivity and agency, and the processes of negotiation these allow, towards an analysis of where these women’s texts necessarily belong to. This kind of analysis is utilized precisely because these texts traverse across the oppressive and the empowering, the status quo and the possibilities of rebellion, and the powerless and the powerful. In the end, such negotiation is seen as Summit Books’ contribution to the contemporary creation of the Philippine feminine – one that demands that no text be reduced to just its class origins, or just the popular.

  19. West nile virus in American white pelican chicks: transmission, immunity, and survival

    Science.gov (United States)

    Sovada, Marsha A.; Pietz, Pamela J.; Hofmeister, Erik K.; Bartos, Alisa J.

    2013-01-01

    West Nile virus (WNV) causes significant mortality of American White Pelican chicks at northern plains colonies. We tested oropharyngeal/cloacal swabs from moribund chicks for shed WNV. Such shedding could enable chick-to-chick transmission and help explain why WNV spreads rapidly in colonies. WNV was detected on swabs from 11% of chicks in 2006 and 52% of chicks in 2007; however, viral titers were low. Before onset of WNV mortality, we tested blood from < 3-week-old chicks for antibodies to WNV; 5% of chicks were seropositive, suggesting passive transfer of maternal antibodies. Among near-fledged chicks, 41% tested positive for anti-WNV antibodies, indicating that they survived infection. Among years and colonies, cumulative incidence of WNV in chicks varied from 28% to 81%, whereas the proportion of chicks surviving WNV (i.e., seropositive) was 64–75%. Our data revealed that WNV kills chicks that likely would fledge in the absence of WNV, that infection of chicks is pervasive, and that significant numbers of chicks survive infection.

  20. Retinal Thickening and Photoreceptor Loss in HIV Eyes without Retinitis.

    Directory of Open Access Journals (Sweden)

    Cheryl A Arcinue

    Full Text Available To determine the presence of structural changes in HIV retinae (i.e., photoreceptor density and retinal thickness in the macula compared with age-matched HIV-negative controls.Cohort of patients with known HIV under CART (combination Antiretroviral Therapy treatment were examined with a flood-illuminated retinal AO camera to assess the cone photoreceptor mosaic and spectral-domain optical coherence tomography (SD-OCT to assess retinal layers and retinal thickness.Twenty-four eyes of 12 patients (n = 6 HIV-positive and 6 HIV-negative were imaged with the adaptive optics camera. In each of the regions of interest studied (nasal, temporal, superior, inferior, the HIV group had significantly less mean cone photoreceptor density compared with age-matched controls (difference range, 4,308-6,872 cones/mm2. A different subset of forty eyes of 20 patients (n = 10 HIV-positive and 10 HIV-negative was included in the retinal thickness measurements and retinal layer segmentation with the SD-OCT. We observed significant thickening in HIV positive eyes in the total retinal thickness at the foveal center, and in each of the three horizontal B-scans (through the macular center, superior, and inferior to the fovea. We also noted that the inner retina (combined thickness from ILM through RNFL to GCL layer was also significantly thickened in all the different locations scanned compared with HIV-negative controls.Our present study shows that the cone photoreceptor density is significantly reduced in HIV retinae compared with age-matched controls. HIV retinae also have increased macular retinal thickness that may be caused by inner retinal edema secondary to retinovascular disease in HIV. The interaction of photoreceptors with the aging RPE, as well as possible low-grade ocular inflammation causing diffuse inner retinal edema, may be the key to the progressive vision changes in HIV-positive patients without overt retinitis.

  1. Integrating toxicity risk in bird eggs and chicks: Using chick down feathers to estimate mercury concentrations in eggs

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.

    2009-01-01

    The concentration of mercury (Hg) in eggs that causes reduced hatching success is regarded as a critical end point for Hg toxicity in birds. However, incorporating effects of in ovo mercury exposure on chick health and survival could improve risk assessment. We developed equations to predict Hg in eggs using Hg in chick down feathers, and vice versa, by assessing the relationship between Hg in feathers (0.5−32.4 μg g−1 fw) and eggs (0.04−2.79 μg g−1 fww) for three waterbird species in San Francisco Bay, CA. Feather Hg sampled from embryos of pipping eggs was highly correlated with fresh whole-egg Hg (n = 94, r2 = 0.96). Additionally, using an egg microsampling technique, albumen Hg was correlated with feather Hg sampled from chicks in the same nest (n = 28, r2 = 0.79). Down feather Hg in recaptured chicks (≤10 days old) was correlated with down feather Hg at hatching (≤3 days old; n = 88, r2 = 0.74). Our results demonstrate the utility of using down feathers of chicks ≤10 days of age to nonlethally predict Hg in eggs and thus provide the ability to develop exposure thresholds for eggs that incorporate in ovo Hg’s effects on both egg hatchability and subsequent chick mortality.

  2. [Application of retinal oximeter in ophthalmology].

    Science.gov (United States)

    Li, Jing; Ma, Jianmin; Wang, Ningli

    2015-11-01

    Retinal oximeter is a new machine which has been used in the diagnose, treatment and research of several ophthalmic diseases for recent years. It allows ophthalmologists to gain retinal oxygen saturation directly. Therefore, retinal oximeter might be useful for ophthalmologists to understand ophthalmic diseases more deeper and clarify the impact of ischemia on retinal function. It has been reported in the literatures that retinal oximeter has potentially useful diagnostic and therapeutic indications in various eye diseases such as diabetic retinopathy, central retinal vein and artery occlusion, retinitis pigmentosa, glaucomatous optic neuropathy, et al. In this thesis, the application of retinal oximeter in ophthalmology is reviewed.

  3. Expressions of visual pigments and synaptic proteins in neonatal chick retina exposed to light of variable photoperiods

    Indian Academy of Sciences (India)

    KUMAR ABHIRAM JHA; TAPAS C NAG; SHASHI WADHWA; TARA SANKAR ROY

    2016-12-01

    Light causes damage to the retina, which is one of the supposed factors for age-related macular degeneration inhuman. Some animal species show drastic retinal changes when exposed to intense light (e.g. albino rats). Althoughbirds have a pigmented retina, few reports indicated its susceptibility to light damage. To know how light influences acone-dominated retina (as is the case with human), we examined the effects of moderate light intensity on the retina ofwhite Leghorn chicks (Gallus g. domesticus). The newly hatched chicks were initially acclimatized at 500 lux for 7days in 12 h light: 12 h dark cycles (12L:12D). From posthatch day (PH) 8 until PH 30, they were exposed to 2000 luxat 12L:12D, 18L:6D (prolonged light) and 24L:0D (constant light) conditions. The retinas were processed fortransmission electron microscopy and the level of expressions of rhodopsin, S- and L/M cone opsins, and synapticproteins (Synaptophysin and PSD-95) were determined by immunohistochemistry and Western blotting. Rearing in24L:0D condition caused disorganization of photoreceptor outer segments. Consequently, there were significantlydecreased expressions of opsins and synaptic proteins, compared to those seen in 12L:12D and 18L:6D conditions.Also, there were ultrastructural changes in outer and inner plexiform layer (OPL, IPL) of the retinas exposed to24L:0D condition. Our data indicate that the cone-dominated chick retina is affected in constant light condition, withchanges (decreased) in opsin levels. Also, photoreceptor alterations lead to an overall decrease in synaptic proteinexpressions in OPL and IPL and death of degenerated axonal processes in IPL.

  4. Aldose reductase mediates retinal microglia activation

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Kun-Che; Shieh, Biehuoy; Petrash, J. Mark, E-mail: mark.petrash@ucdenver.edu

    2016-04-29

    Retinal microglia (RMG) are one of the major immune cells in charge of surveillance of inflammatory responses in the eye. In the absence of an inflammatory stimulus, RMG reside predominately in the ganglion layer and inner or outer plexiform layers. However, under stress RMG become activated and migrate into the inner nuclear layer (INL) or outer nuclear layer (ONL). Activated RMG in cell culture secrete pro-inflammatory cytokines in a manner sensitive to downregulation by aldose reductase inhibitors. In this study, we utilized CX3CR1{sup GFP} mice carrying AR mutant alleles to evaluate the role of AR on RMG activation and migration in vivo. When tested on an AR{sup WT} background, IP injection of LPS induced RMG activation and migration into the INL and ONL. However, this phenomenon was largely prevented by AR inhibitors or in AR null mice, or was exacerbated in transgenic mice that over-express AR. LPS-induced increases in ocular levels of TNF-α and CX3CL-1 in WT mice were substantially lower in AR null mice or were reduced by AR inhibitor treatment. These studies demonstrate that AR expression in RMG may contribute to the proinflammatory phenotypes common to various eye diseases such as uveitis and diabetic retinopathy. - Highlights: • AR inhibition prevents retinal microglial activation. • Endotoxin-induced ocular cytokine production is reduced in AR null mice. • Overexpression of AR spontaneously induces retinal microglial activation.

  5. Postfeminist Fiction in Chick Lit Novels

    Directory of Open Access Journals (Sweden)

    Ilief-Martinescu Alina

    2015-12-01

    Full Text Available The intersection of postfeminist arguments with popular culture and popular cultural forms is of great significance for investigating representational politics and issues of identity. These elements are central for capturing the concept of feminist heterogeneity in its engagement with cultural theory, particularly postmodernism. This study considers postfeminism’s redefinition and reevaluation of popular culture, as an area of political and emblematic contestation.

  6. Retinal oximetry in patients with ischaemic retinal diseases

    DEFF Research Database (Denmark)

    Rilvén, Sandra; Torp, Thomas Lee; Grauslund, Jakob

    2017-01-01

    increased retinal arterial oxygen saturation (raSatO2 ) in patients with DR. In patients with central retinal vein occlusion (CRVO), all studies found that rvSatO2 was reduced, but raSatO2 remained unchanged. Branch retinal vein occlusion was not associated with changes in retinal oxygen saturation......, but this was based on a single study. In conclusion, DR is associated with increased rvSatO2 and might also be related to increased raSatO2 . Central retinal vein occlusion (CRVO) is correlated with increased rvSatO2 but unrelated to raSatO2 . Prospective studies are needed to expand these findings. These would tell...... retinopathy (DR) and four about retinal vein occlusion. No studies about retinal artery occlusion were included. In diabetes, all studies found that increases in retinal venous oxygen saturation (rvSatO2 ) were associated with present as well as increasing levels of DR. Four of six studies also found...

  7. Effects of zinc and PGE sub 2 on bone metabolism in chick tibia

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D.; Pierce, W.M. Jr. (Univ. of Louisville, KY (United States))

    1991-03-15

    The effects of zinc and prostaglandin E{sub 2} (PGE{sub 2}) on bone metabolism were investigated. Tibiae were removed from 19 day chicks and cultured for periods up to 72 hours in a chemically defined medium. Calcium release from tibiae cultured in the presence of 50-100 ug/dl zinc or 10{sup {minus}9}-10{sup {minus}7} M PGE{sub 2} between 24 and 48 hours increased significantly in a concentration dependent fashion. When 100 ug/dl zinc was added with 10{sup {minus}9}-10{sup {minus}7} M PGE{sub 2} to the culture bone, no additive effect was observed. Flurbiprofen decreased calcium release from chick tibiae significantly in the 24-48 hour incubation period in a concentration dependent fashion, suggesting that endogenous PG's have stimulatory effect on bone calcium release. When 10{sup {minus}6} M flurbiprofen was added with 25-100 ug/dl zinc, the calcium release from tibiae was not changed significantly. Bone release from tibiae was not changed significantly. Bone alkaline phosphatase activity was elevated by 50-100 ug/dl zinc. Addition of PGE{sub 2} did not increase the zinc stimulated elevation of alkaline phosphatase activity. The authors propose the following: zinc stimulates bone cell proliferation; PGE{sub 2} stimulates calcium release from the limited number of osteoclasts in cultured embryonic tibiae; and most bone organ culture system are models of zinc deficiency, since incubation of physiological concentrations of zinc has significant effect.

  8. Retinal detachment surgery without cryotherapy.

    OpenAIRE

    Chignell, A H; Markham, R H

    1981-01-01

    A series of cases of retinal detachment treated without the application of cryotherapy at the time of surgery has been studied. The omission of cryotherapy while not interfering with retinal reattachment, carries the risk of redetachment at a later date. Macular pucker may still occur in spite of the absence of cryotherapy.

  9. Perceptual Fading without Retinal Adaptation

    Science.gov (United States)

    Hsieh, Po-Jang; Colas, Jaron T.

    2012-01-01

    A retinally stabilized object readily undergoes perceptual fading and disappears from consciousness. This startling phenomenon is commonly believed to arise from local bottom-up sensory adaptation to edge information that occurs early in the visual pathway, such as in the lateral geniculate nucleus of the thalamus or retinal ganglion cells. Here…

  10. Detour behaviour, imprinting and visual lateralization in the domestic chick.

    Science.gov (United States)

    Vallortigara, G; Regolin, L; Pagni, P

    1999-01-01

    Detour behaviour was studied in chicks faced with a vertical-bar barrier behind where an imprinting object (a red ball) was located. Right-eyed chicks took less time to detour the barrier than left-eyed chicks, and binocular chicks showed a bias to detour the barrier on the left side, thus maintaining visual contact with the imprinting object using the lateral field of the right eye, while circling around the barrier. In males, the asymmetries were consistent all along the first two weeks of life, whereas in females they disappeared on days 8 and 11. When tested with a slightly novel version of the original imprinting object (i.e., a ball of a different color), binocular chicks showed a bias to detour the barrier on the right side, thus showing preferential use of the left eye. The same bias occurred when unfamiliar conspecifics were used as goal-objects. Results suggest that cerebral lateralization in birds can directly affect visually-guided motor responses through selective use of the lateral field of vision of the eye contralateral to the hemisphere which has to be put in charge of control of overt behaviour. Copyright 1999 Elsevier Science B.V.

  11. Spontaneous generalization of abstract multimodal patterns in young domestic chicks.

    Science.gov (United States)

    Versace, Elisabetta; Spierings, Michelle J; Caffini, Matteo; Ten Cate, Carel; Vallortigara, Giorgio

    2017-05-01

    From the early stages of life, learning the regularities associated with specific objects is crucial for making sense of experiences. Through filial imprinting, young precocial birds quickly learn the features of their social partners by mere exposure. It is not clear though to what extent chicks can extract abstract patterns of the visual and acoustic stimuli present in the imprinting object, and how they combine them. To investigate this issue, we exposed chicks (Gallus gallus) to three days of visual and acoustic imprinting, using either patterns with two identical items or patterns with two different items, presented visually, acoustically or in both modalities. Next, chicks were given a choice between the familiar and the unfamiliar pattern, present in either the multimodal, visual or acoustic modality. The responses to the novel stimuli were affected by their imprinting experience, and the effect was stronger for chicks imprinted with multimodal patterns than for the other groups. Interestingly, males and females adopted a different strategy, with males more attracted by unfamiliar patterns and females more attracted by familiar patterns. Our data show that chicks can generalize abstract patterns by mere exposure through filial imprinting and that multimodal stimulation is more effective than unimodal stimulation for pattern learning.

  12. Hypoxia adaptation and hemoglobin mutation in Tibetan chick embryo

    Institute of Scientific and Technical Information of China (English)

    GOU Xiao; LI Ning; LIAN Linsheng; YAN Dawei; ZHANG Hao; WU Changxin

    2005-01-01

    Tibetan chick lives at high altitudes between 2600 and 4200 m with a high hatchability and low land breeds survive rarely with a hatchability of 3.0% under hypoxia of simulated 4200 m. Under hypoxia of whole 21 d, the hatchability of Tibetan chick and Recessive White Feather broiler differed with a greatest disparity from day 4 to 11 and also significantly in other stages except from day 1 to 3. Hypoxia in each stage did not reduce significantly survival rate of this stage except hatchability. These two results indicated that the hypoxia in the early stage had an adverse effect on the later stage. All exons encoding chick hemoglobins were sequenced to analyze gene polymorphism. The functional mutation Met-32(B13)-Leu, related with hypoxia, was found in αD globin chain and the mutation frequency increased with increased altitude. In addition, under hypoxic conditions, the population with higher mutation frequency had a higher hatchability. The automated homology model building was carried out using crystal structure coordinates of chick HbD. The results indicated that the substitution Met-32(B13)-Leu provides a more hydrophobic environment which leads to higher stability of heme and oxygen affinity of hemoglobin. The occurrence of the mutation Met-32(B13)-Leu is related to the origin of Tibetan chick.

  13. Pharmacokinetics of paracetamol in chicks treated with metronidazole

    Directory of Open Access Journals (Sweden)

    S.M. Hussain

    2017-06-01

    Full Text Available Effect of metronidazole on the pharmacokinetics of paracetamol were examined in chicks. Chicks were dosed orally with metronidazole at 350 mg\\kg of body weight daily (10 -13 days of age. On the last day of metronidazole dosing, chicks injected intraperitoneally with paracetamol at of 50 mg\\kg of body weight. Paracetamol appeared in chick plasma at 52.00, 45.00, 40.75, 32.75, 23.25 µg \\ml after 0.25, 0.50, 0.75, 1, 2, 4 hours of injection respectively. A significantly decreased the concentration paracetamol at times of 0.25, 0.50, 0.75, 1, 4 hours post injection and appeared at concentrations of 36.62, 35.37, 25.62, 20.50, 11.00 µg\\ml. These was reflected by changes in the pharmacokinetics of paracetamol as show by the increase elimination rate constant (48% and decrease in the half-life (32 % and increase in volume distribution (29% and increase in clearance by (96% and decrease in the area under the plasma curve (33% and decrease in the area under moment curve 65% and lack mean residence time (33%. These results indicate that oral dosing of chicks with metronidazole for four consecutive days and this effect increase in the elemination rate of paracetamol and this effect must be considered when therapy with paracetamol when given during metronidazole therapy.

  14. Cognitive bias in the chick anxiety-depression model.

    Science.gov (United States)

    Salmeto, Amy L; Hymel, Kristen A; Carpenter, Erika C; Brilot, Ben O; Bateson, Melissa; Sufka, Kenneth J

    2011-02-10

    Cognitive bias is a phenomenon that presents in clinical populations where anxious individuals tend to adopt a more pessimistic-like interpretation of ambiguous aversive stimuli whereas depressed individuals tend to adopt a less optimistic-like interpretation of ambiguous appetitive stimuli. To further validate the chick anxiety-depression model as a neuropsychiatric simulation we sought to quantify this cognitive endophenotype. Chicks exposed to an isolation stressor of 5m to induce an anxiety-like or 60 m to induce a depressive-like state were then tested in a straight alley maze to a series of morphed ambiguous appetitive (chick silhouette) to aversive (owl silhouette) cues. In non-isolated controls, runway start and goal latencies generally increased as a function of greater amounts of aversive characteristics in the cues. In chicks in the anxiety-like state, runway latencies were increased to aversive ambiguous cues, reflecting more pessimistic-like behavior. In chicks in the depression-like state, runway latencies were increased to both aversive and appetitive ambiguous cues, reflecting more pessimistic-like and less optimistic-like behavior, respectively.

  15. Spectrophotometric retinal oximetry in pigs

    DEFF Research Database (Denmark)

    Traustason, Sindri; Kiilgaard, Jens Folke; Karlsson, Robert

    2013-01-01

    PURPOSE: To assess the validity of spectrophotometric retinal oximetry, by comparison to blood gas analysis and intra-vitreal measurements of partial pressure of oxygen (pO2). METHODS: Female domestic pigs were used for all experiments (n=8). Oxygen fraction in inspired air was changed using...... a mixture of room air, pure oxygen and pure nitrogen, ranging from 5% to 100% oxygen. Femoral arterial blood gas analysis and retinal oximetry was performed at each level of inspiratory oxygen fraction. Retinal oximetry was performed using a commercial instrument, the Oxymap Retinal Oximeter T1 (Oxymap ehf......, Reykjavik, Iceland). The device simultaneously acquires images at two wavelengths (570 nm and 600 nm) and specialized software automatically detects retinal blood vessels. In three pigs, invasive pO2-measurements were performed after the initial non-invasive measurements. RESULTS: Comparison of femoral...

  16. Bilateral retinitis following typhoid fever.

    Science.gov (United States)

    Prabhushanker, M; Topiwalla, Tasneem T; Ganesan, Geetha; Appandaraj, Sripal

    2017-01-01

    Post typhoid fever immune related reactions affecting the eye is a rare finding which can have various presentations in which typhoid retinopathy is not a well recognized sequelae. Here we present a case of 59 year old male who presented with right eye sudden painless loss of vision 4 weeks after typhoid fever which was diagnosed and treated successfully. His BCVA was 2/60 in right eye and 6/6 in left eye. Fundus examination showed retinitis along with macular serous detachment in right eye and retinitis in left eye. Significant improvement in BCVA in right eye was observed after treatment with oral steroid with resolving retinitis lesions. Diagnosis of post typhoid immune mediated retinitis was made with good resolution following treatment. Immune mediated retinitis is a rare sequelae to typhoid infection which can be successfully treated with systemic steroids with good resolution of the lesions.

  17. Intermediate frequency magnetic field and chick embryotoxicity.

    Science.gov (United States)

    Nishimura, Izumi; Tanaka, Keiko; Negishi, Tadashi

    2013-09-01

    Intermediate frequency magnetic fields (MFs) have widely been used in industrial machines and home appliances, such as induction heating cookers, although toxicity studies to evaluate the potential health risks of such fields are insufficient. In induction heating cookers, the MF source (i.e. hobs), is located near the abdominal position of a person cooking. Hence, developmental effects on the fetus may be a concern in case the person is a pregnant woman. Fertile White Leghorn eggs (60/group) were either exposed to 20 kHz, 1.1 mT(rms) or 60 kHz, 0.11 mT(rms) sinusoidal MFs for 19 days during embryogenesis. The same number of eggs served as a control group. In addition, a sham-sham experiment was conducted to validate the equality between exposure and control facilities. After exposure, embryos were examined for mortality rate and stage. Live embryos were evaluated for developmental stage and gross and skeletal anomalies. Length of upper beak and leg digits was also measured. Examinations were conducted in a blinded fashion to ensure quality assurance; experiments were triplicated for each frequency to confirm the outcome reproducibility. Mortality rate and stage, incidence of malformed embryos, and developmental variables in live embryos were found to be similar between the MF-exposed and corresponding control group. Incidence of gross anomalies such as mandibular edema and skeletal anomalies such as coccyx defects were low across the experiments, and no significant group differences were noted. In conclusion, exposure to 20 kHz or 60 kHz MF did not produce any significant teratogenic developmental effects in chick embryos.

  18. Neuroprotective effects of citicoline in in vitro models of retinal neurodegeneration.

    Science.gov (United States)

    Matteucci, Andrea; Varano, Monica; Gaddini, Lucia; Mallozzi, Cinzia; Villa, Marika; Pricci, Flavia; Malchiodi-Albedi, Fiorella

    2014-04-14

    In recent years, citicoline has been the object of remarkable interest as a possible neuroprotectant. The aim of this study was to investigate if citicoline affected cell survival in primary retinal cultures and if it exerted neuroprotective activity in conditions modeling retinal neurodegeneration. Primary retinal cultures, obtained from rat embryos, were first treated with increasing concentrations of citicoline (up to 1000 µM) and analyzed in terms of apoptosis and caspase activation and characterized by immunocytochemistry to identify neuronal and glial cells. Subsequently, excitotoxic concentration of glutamate or High Glucose-containing cell culture medium (HG) was administered as well-known conditions modeling neurodegeneration. Glutamate or HG treatments were performed in the presence or not of citicoline. Neuronal degeneration was evaluated in terms of apoptosis and loss of synapses. The results showed that citicoline did not cause any damage to the retinal neuroglial population up to 1000 µM. At the concentration of 100 µM, it was able to counteract neuronal cell damage both in glutamate- and HG-treated retinal cultures by decreasing proapoptotic effects and contrasting synapse loss. These data confirm that citicoline can efficiently exert a neuroprotective activity. In addition, the results suggest that primary retinal cultures, under conditions inducing neurodegeneration, may represent a useful system to investigate citicoline neuroprotective mechanisms.

  19. Neuroprotective Effects of Citicoline in in Vitro Models of Retinal Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Andrea Matteucci

    2014-04-01

    Full Text Available In recent years, citicoline has been the object of remarkable interest as a possible neuroprotectant. The aim of this study was to investigate if citicoline affected cell survival in primary retinal cultures and if it exerted neuroprotective activity in conditions modeling retinal neurodegeneration. Primary retinal cultures, obtained from rat embryos, were first treated with increasing concentrations of citicoline (up to 1000 µM and analyzed in terms of apoptosis and caspase activation and characterized by immunocytochemistry to identify neuronal and glial cells. Subsequently, excitotoxic concentration of glutamate or High Glucose-containing cell culture medium (HG was administered as well-known conditions modeling neurodegeneration. Glutamate or HG treatments were performed in the presence or not of citicoline. Neuronal degeneration was evaluated in terms of apoptosis and loss of synapses. The results showed that citicoline did not cause any damage to the retinal neuroglial population up to 1000 µM. At the concentration of 100 µM, it was able to counteract neuronal cell damage both in glutamate- and HG-treated retinal cultures by decreasing proapoptotic effects and contrasting synapse loss. These data confirm that citicoline can efficiently exert a neuroprotective activity. In addition, the results suggest that primary retinal cultures, under conditions inducing neurodegeneration, may represent a useful system to investigate citicoline neuroprotective mechanisms.

  20. cultural

    Directory of Open Access Journals (Sweden)

    Irene Kreutz

    2006-01-01

    Full Text Available Es un estudio cualitativo que adoptó como referencial teorico-motodológico la antropología y la etnografía. Presenta las experiencias vivenciadas por mujeres de una comunidad en el proceso salud-enfermedad, con el objetivo de comprender los determinantes sócio-culturales e históricos de las prácticas de prevención y tratamiento adoptados por el grupo cultural por medio de la entrevista semi-estructurada. Los temas que emergieron fueron: la relación entre la alimentación y lo proceso salud-enfermedad, las relaciones con el sistema de salud oficial y el proceso salud-enfermedad y lo sobrenatural. Los dados revelaron que los moradores de la comunidad investigada tienen un modo particular de explicar sus procedimientos terapéuticos. Consideramos que es papel de los profesionales de la salud en sus prácticas, la adopción de abordajes o enfoques que consideren al individuo en su dimensión sócio-cultural e histórica, considerando la enorme diversidad cultural en nuestro país.

  1. Changes in free amino acid and monoamine concentrations in the chick brain associated with feeding behavior

    OpenAIRE

    Tran, Phuong V; Chowdhury, Vishwajit S.; Nagasawa, Mao; Furuse, Mitsuhiro

    2015-01-01

    Domesticated chicks are precocial and therefore have relatively well-developed feeding behavior. The role of hypothalamic neuropeptides in food-intake regulation in chicks has been reported for decades. However, we hypothesized that nutrients and their metabolites in the brain may be involved in food intake in chicks because these animals exhibit a very frequent feeding pattern. Therefore, the purpose of this study was to examine the feeding behavior of chicks as well as the associated change...

  2. Causes of mortality of albatross chicks at Midway Atoll

    Science.gov (United States)

    Sileo, L.; Sievert, P.R.; Samuel, M.D.

    1990-01-01

    As part of an investigation of the effect of plastic ingestion on seabirds in Hawaii, we necropsied the carcasses of 137 Laysan albatross (Diomedea immutabilis) chicks from Midway Atoll in the Pacific Ocean during the summer of 1987. Selected tissues were collected for microbiological, parasitological, toxicological or histopathological examinations. Dehydration was the most common cause of death. Lead poisoning, trauma, emaciation (starvation) and trombidiosis were other causes of death; nonfatal nocardiosis and avian pox also were present. There was no evidence that ingested plastic caused mechanical lesions or mortality in 1987, but most of the chicks had considerably less plastic in them than chicks from earlier years. Human activity (lead poisoning and vehicular trauma) caused mortality at Midway Atoll and represented additive mortality for pre-fledgling albatrosses.

  3. Acute retinal necrosis

    Directory of Open Access Journals (Sweden)

    Hugo Hernán Ocampo

    2009-12-01

    Full Text Available Purpose: Clinical features in a case of acute retinal necrosis are described as well as its diagnostic approach and response to early treatment. Methods: This is a descriptive and retrospective study case report of a 26 year old male patient who arrived to the emergency room with a three day history of sudden visual loss in the right eye (RE. At initial evaluation a visual acuity of hand movements in the RE, 20/15 in the left eye (LE and a right relative afferent pupillary defect were found. Fundoscopy revealed profuse soft exudates and hemorrhages involving posterior pole, inferior hemiretina and superotemporal periphery. Infectious workup and fluoresceinic angiography were made and positive serologies for herpes virus types 1 and 2, without HIV, were found. A diagnosis of acute retinal necrosis was made and treatment with intravenous valgancyclovir for two weeks and intra-vitreous triamcinolone for severe vasculitis, was given. Then a 3 months treatment with oral antiviral agents was prescribed. Results: Patient’s evolution showed improvement with treatment and at two and a half months of follow up, visual acuity was 20/50 in the right eye, normal slit lamp examination, tonometry of 12 mm Hg and fundoscopy improved when compared to initial pictures.Conclusions: A high index of suspicion is needed for diagnosing ARN taking into account clinical findings. Prompt intravenous and intra-vitreous treatments are needed to achieve good clinical and functional outcomes and to avoid central nervous system complications.

  4. PATHOLOGICAL AND SERUM BIOCHEMICAL EFFECTS OF SALINOMYCIN ON LAYER CHICKS

    Directory of Open Access Journals (Sweden)

    F. RIZVI, A. D. ANJUM, A. KHAN, M. MOHSAN AND M. SHAZAD

    2008-01-01

    Full Text Available Effects of continuous and over dosage of salinomycin was studied experimentally in layer chicks.Salinomycin was given to layers @ 60, 120 and 180 ppm in feed up to the age of 12 weeks. During the courseof trial, the birds of all groups were active and did not show any clinical signs. Body weight started decreasingsignificantly (P<0.001 in chicks receiving 60, 120 and 180 ppm salinomycin compared to the control groupfrom the 11th, 5th and 3rd week onward, respectively. Feed conversion ratio at 12th week was 3.537 in the controlcompared with 3.701, 4.250 and 4.465 in layer chicks given salinomycin at the rate of 60, 120 and 180 ppm,respectively. Absolute weight of liver at 12th week and absolute weight of kidneys throughout the experimentdecreased significantly (P<0.001 in chicks receiving 180 ppm salinomycin. Concentrations of AST, ALT,blood urea and creatinine were higher in layers receiving 180 ppm salinomycin, while serum total bilirubinconcentration was increased significantly (P<0.001 in layers receiving 120 and 180 ppm salinomycin. No grosslesions were observed in liver and kidneys of layers receiving various doses of salinomycin. Microscopically,there was congestion of liver sinusides and vacuolization of hepatocytes in chicks receiving 180 ppmsalinomycin. There was hydropic degeneration of tubular epithelium, degeneration and desquamation of most ofcells of Bowman’s capsule epithelium of kidneys in birds receiving 180 ppm salinomycin. Higher doses ofsalinomycin seem to alter liver and kidney functions subclinically in layer chicks.

  5. Morphometrics of corneal growth in chicks raised in constant light.

    Science.gov (United States)

    Wahl, Christina; Li, Tong; Choden, Tsering; Howland, Howard

    2009-03-01

    In this study we wish to augment our understanding of the effect of environment on corneal growth and morphology. To understand how corneal development of chicks raised in constant light differs from that of 'normal' eyes exposed to cyclic periods of light and dark, white Leghorn chicks were raised under either constant light (approximately 700 lux at cage top) or in 12 h light/12 h dark conditions for up to 12 weeks after hatching. To determine whether corneal expansion is uniform, some birds from each group received corneal tattoos for periodic photographic assessment. By 16 days of age, constant light corneas weighed less than light/dark regimen corneas [7.39 +/- 0.35 mg (SE) vs. 8.47 mg +/- 0.26 mg SE wet weight, P < or = 0.05], and corresponding differences were seen in corneal dry weights. Spatial expansion of the corneal surface was uniform in both groups, but the rate of expansion was slower in constant light chicks [0.0327 +/- 0.009 (SE) vs. 0.144 +/- 0.018 (SE) mm(2) day(-1) for normal chicks, P < or = 0.001]. At 1 day of age, there were 422 +/- 12.5 (SE) stromal cells 0.01 mm(-2) in the central cornea and 393 +/- 21.5 (SE) stromal cells 0.01 mm(-2 )peripherally. Although this difference is not statistically significant, the cell densities in the central cornea were always larger than those of the peripheral cornea in all eight measurements over a 10.5-week period, and this difference is significant (P < or = 0.008, binomial test). Light/dark regimen birds show no such consistent difference in cell densities between central and peripheral corneas. Thus, the density distribution of corneal stromal cells of chicks grown in constant light differs from that of normal chicks. Taken together, all these observations suggest that diurnal cycles of light and darkness are necessary for normal corneal growth.

  6. Live-cell imaging: new avenues to investigate retinal regeneration.

    Science.gov (United States)

    Lahne, Manuela; Hyde, David R

    2017-08-01

    Sensing and responding to our environment requires functional neurons that act in concert. Neuronal cell loss resulting from degenerative diseases cannot be replaced in humans, causing a functional impairment to integrate and/or respond to sensory cues. In contrast, zebrafish (Danio rerio) possess an endogenous capacity to regenerate lost neurons. Here, we will focus on the processes that lead to neuronal regeneration in the zebrafish retina. Dying retinal neurons release a damage signal, tumor necrosis factor α, which induces the resident radial glia, the Müller glia, to reprogram and re-enter the cell cycle. The Müller glia divide asymmetrically to produce a Müller glia that exits the cell cycle and a neuronal progenitor cell. The arising neuronal progenitor cells undergo several rounds of cell divisions before they migrate to the site of damage to differentiate into the neuronal cell types that were lost. Molecular and immunohistochemical studies have predominantly provided insight into the mechanisms that regulate retinal regeneration. However, many processes during retinal regeneration are dynamic and require live-cell imaging to fully discern the underlying mechanisms. Recently, a multiphoton imaging approach of adult zebrafish retinal cultures was developed. We will discuss the use of live-cell imaging, the currently available tools and those that need to be developed to advance our knowledge on major open questions in the field of retinal regeneration.

  7. Live-cell imaging: new avenues to investigate retinal regeneration

    Directory of Open Access Journals (Sweden)

    Manuela Lahne

    2017-01-01

    Full Text Available Sensing and responding to our environment requires functional neurons that act in concert. Neuronal cell loss resulting from degenerative diseases cannot be replaced in humans, causing a functional impairment to integrate and/or respond to sensory cues. In contrast, zebrafish (Danio rerio possess an endogenous capacity to regenerate lost neurons. Here, we will focus on the processes that lead to neuronal regeneration in the zebrafish retina. Dying retinal neurons release a damage signal, tumor necrosis factor α, which induces the resident radial glia, the Müller glia, to reprogram and re-enter the cell cycle. The Müller glia divide asymmetrically to produce a Müller glia that exits the cell cycle and a neuronal progenitor cell. The arising neuronal progenitor cells undergo several rounds of cell divisions before they migrate to the site of damage to differentiate into the neuronal cell types that were lost. Molecular and immunohistochemical studies have predominantly provided insight into the mechanisms that regulate retinal regeneration. However, many processes during retinal regeneration are dynamic and require live-cell imaging to fully discern the underlying mechanisms. Recently, a multiphoton imaging approach of adult zebrafish retinal cultures was developed. We will discuss the use of live-cell imaging, the currently available tools and those that need to be developed to advance our knowledge on major open questions in the field of retinal regeneration.

  8. Adenosine A3 receptor activation is neuroprotective against retinal neurodegeneration.

    Science.gov (United States)

    Galvao, Joana; Elvas, Filipe; Martins, Tiago; Cordeiro, M Francesca; Ambrósio, António Francisco; Santiago, Ana Raquel

    2015-11-01

    Death of retinal neural cells, namely retinal ganglion cells (RGCs), is a characteristic of several retinal neurodegenerative diseases. Although the role of adenosine A3 receptor (A3R) in neuroprotection is controversial, A3R activation has been reported to afford protection against several brain insults, with few studies in the retina. In vitro models (retinal neural and organotypic cultures) and animal models [ischemia-reperfusion (I-R) and partial optic nerve transection (pONT)] were used to study the neuroprotective properties of A3R activation against retinal neurodegeneration. The A3R selective agonist (2-Cl-IB-MECA, 1 μM) prevented apoptosis (TUNEL(+)-cells) induced by kainate and cyclothiazide (KA + CTZ) in retinal neural cultures (86.5 ± 7.4 and 37.2 ± 6.1 TUNEL(+)-cells/field, in KA + CTZ and KA + CTZ + 2-Cl-IB-MECA, respectively). In retinal organotypic cultures, 2-Cl-IB-MECA attenuated NMDA-induced cell death, assessed by TUNEL (17.3 ± 2.3 and 8.3 ± 1.2 TUNEL(+)-cells/mm(2) in NMDA and NMDA+2-Cl-IB-MECA, respectively) and PI incorporation (ratio DIV4/DIV2 3.3 ± 0.3 and 1.3 ± 0.1 in NMDA and NMDA+2-Cl-IB-MECA, respectively) assays. Intravitreal 2-Cl-IB-MECA administration afforded protection against I-R injury decreasing the number of TUNEL(+) cells by 72%, and increased RGC survival by 57%. Also, intravitreal administration of 2-Cl-IB-MECA inhibited apoptosis (from 449.4 ± 37.8 to 207.6 ± 48.9 annexin-V(+)-cells) and RGC loss (from 1.2 ± 0.6 to 8.1 ± 1.7 cells/mm) induced by pONT. This study demonstrates that 2-Cl-IB-MECA is neuroprotective to the retina, both in vitro and in vivo. Activation of A3R may have great potential in the management of retinal neurodegenerative diseases characterized by RGC death, as glaucoma and diabetic retinopathy, and ischemic diseases.

  9. Immunization of young chicks using graded dose of wild strain of Eimeria tenella

    Directory of Open Access Journals (Sweden)

    E.N. Kimbita

    2005-09-01

    Full Text Available A wild strain of Eimeria tenella was isolated and utilized for immunization studies. Its optimal sporulation was attained at room temperature 24-25 °C after 24-48 h. Two groups of chicks were immunized by dosing a graded dose of five oocysts/chick/day for 6 days followed by 50 oocysts/chick/day for 7 days. A third group was not immunized and served as a negative control. Immunized chicks gained mass at the same rate as unimmunized ones, but when challenged with 200 000 oocysts/chick, mass gains declined in the unimmunized group. The growth rate of immunized chicks was not affected by challenge (P > 0.05. Upon challenge, unimmunized chicks produced significantly more oocysts than immunized chicks (P < 0.005. Immunized chicks withstood a challenged with 200 000 oocysts/chick without developing any clinical signs whereas the unimmunized chicks developed typical clinical signs of coccidiosis. Unimmunized chicks had significantly more severe lesions in the caecum than any other group (P > 0.005 and also produced significantly more oocysts than any other group (P > 0.005.

  10. Interpreting variation in growth of Eurasian Spoonbill chicks: disentangling the effects of age, sex and environment

    NARCIS (Netherlands)

    Lok, T.; Overdijk, O.; Piersma, T.

    2014-01-01

    Chick body condition can be a sensitive indicator of local environmental conditions and has been shown to be correlated with chick survival. Designing a reliable index of chick body condition for a given species from a single measurement point requires knowledge about the extent of variation in body

  11. Treatment of Laser-Induced Retinal Injuries

    Science.gov (United States)

    1989-06-29

    Distribution List (enclosed) bI’TF rruIoN STATEMEN A Approved for publi reljaso Disatbunon Unlimited TREATMENT OF LASER-INDUCED RETINAL INJURIES FINAL...suprathreshold retinal laser lesions II. Subthreshold retinal laser lesions III. Effect of steroid treatment on laser-induced retinal injury Discussion and...In the present study we investigated the effect of corticosteroid treatment of argon laser-induced retinal injury on vitreal accumulation of both

  12. FGF signaling pathway in the developing chick lung: expression and inhibition studies.

    Directory of Open Access Journals (Sweden)

    Rute S Moura

    Full Text Available BACKGROUND: Fibroblast growth factors (FGF are essential key players during embryonic development. Through their specific cognate receptors (FGFR they activate intracellular cascades, finely regulated by modulators such as Sprouty. Several FGF ligands (FGF1, 2, 7, 9, 10 and 18 signaling through the four known FGFRs, have been implicated in lung morphogenesis. Although much is known about mammalian lung, so far, the avian model has not been explored for lung studies. METHODOLOGY/PRINCIPAL FINDINGS: In this study we provide the first description of fgf10, fgfr1-4 and spry2 expression patterns in early stages of chick lung development by in situ hybridization and observe that they are expressed similarly to their mammalian counterparts. Furthermore, aiming to determine a role for FGF signaling in chick lung development, in vitro FGFR inhibition studies were performed. Lung explants treated with an FGF receptor antagonist (SU5402 presented an impairment of secondary branch formation after 48 h of culture; moreover, abnormal lung growth with a cystic appearance of secondary bronchi and reduction of the mesenchymal tissue was observed. Branching and morphometric analysis of lung explants confirmed that FGFR inhibition impaired branching morphogenesis and induced a significant reduction of the mesenchyme. CONCLUSIONS/SIGNIFICANCE: This work demonstrates that FGFRs are essential for the epithelial-mesenchymal interactions that determine epithelial branching and mesenchymal growth and validate the avian embryo as a good model for pulmonary studies, namely to explore the FGF pathway as a therapeutic target.

  13. /sup 3/H-retinol derived photopigment in chick pineal membranes

    Energy Technology Data Exchange (ETDEWEB)

    Wallingford, J.; Zatz, M.

    1986-05-01

    Pineal glands display a day-night rhythm in the synthesis and secretion of melatonin. Dispersed chick pinealocytes retain their ability to respond to light in vitro for at least a week. Pinealocytes incubated overnight with /sup 3/H-retinol in the dark incorporate radioactivity predominantly into retinyl esters. To identify the chick pineal photopigment, SDS-PAGE was performed on radiolabelled preparations of pinealocytes and (intraocularly injected) rat retina. When intact cells or membrane preparations of cultured cells were incubated with NaCNBH/sub 3/, in the dark, a single radioactive peak with an apparent molecular weight of 32,000 daltons was observed. Rat retina preparations revealed a major peak at approximately 40,000 daltons. Protease inhibitors were present in the workup, and radioactivity corresponding to the smaller peak from pineal was not observed in retina. There was no radioactive peak when NaCNBH/sub 3/ was omitted. When samples were boiled in SDS the radioactivity shifted to the origin. These data suggest a protein in pinealocyte membranes which binds retinoid via a Schiff's base. Exposure to light of deoxycholate solubilized pineal membranes reduced the radioactivity associated with the protein. These findings raise the possibility that this protein is the pinealocyte's photopigment. Photopigments smaller than those observed in mammals have been reported in invertebrates.

  14. The chick embryo as an experimental system for melanoma cell invasion.

    Directory of Open Access Journals (Sweden)

    Christian Busch

    Full Text Available BACKGROUND: A primary cutaneous melanoma will not kill the patient, but its metastases. Since in vitro studies on melanoma cells in 2-D cultures do often not reflect reality, 3-D models might come closer to the physiological situation in the patient during cancer initiation and progression. METHODOLOGY/PRINCIPAL FINDINGS: Here, we describe the chick embryo model for in vivo studies of melanoma cell migration and invasion. After transplantation of neural crest-derived melanoma cells into the neural tube, the melanoma cells resume neural crest cell migration along the medial and lateral pathways and finally undergo apoptosis in the target areas. Upon transplantation into ectopic areas such as the hindbrain or the optic cup malignant invasion and local tissue destruction occurs. In contrast, melanocytes are not able to spontaneously resume neural crest cell migration. However, malignant invasion can be induced in melanocytes by pre-treatment with the TGF-beta family members bone morphegenetic protein-2 or nodal. Transplantation of MCF7 breast cancer cells yields a different growth pattern in the rhombencephalon than melanoma cells. CONCLUSIONS/SIGNIFICANCE: The chick embryo model is a feasible, cost-effective in vivo system to study invasion by cancer cells in an embryonic environment. It may be useful to study invasive behavior induced by embryonic oncogenes and for targeted manipulation of melanoma or breast cancer cells aiming at ablation of invasive properties.

  15. Retinal Microvascular Abnormalities in Neurofibromatosis Type 1 Associated with Congenital Retinal Macrovessels

    Science.gov (United States)

    Makino, Shinji; Endoh, Katsuhisa; Tampo, Hironobu

    2013-01-01

    Here, we report a case of retinal microvascular abnormalities in a patient with neurofibromatosis type 1 (NF1) associated with congenital retinal macrovessels. An abnormal retinal macrovessel, crossing the macula horizontally, was detected in the right eye. Additionally, retinal microvascular abnormalities were detected. Eight years after the initial visit, the retinal microvascular abnormalities were noted to have changed substantially. We speculate that retinal microvascular abnormalities in NF1 may change dynamically over the years. PMID:23781366

  16. Retinal Microvascular Abnormalities in Neurofibromatosis Type 1 Associated with Congenital Retinal Macrovessels

    Directory of Open Access Journals (Sweden)

    Shinji Makino

    2013-01-01

    Full Text Available Here, we report a case of retinal microvascular abnormalities in a patient with neurofibromatosis type 1 (NF1 associated with congenital retinal macrovessels. An abnormal retinal macrovessel, crossing the macula horizontally, was detected in the right eye. Additionally, retinal microvascular abnormalities were detected. Eight years after the initial visit, the retinal microvascular abnormalities were noted to have changed substantially. We speculate that retinal microvascular abnormalities in NF1 may change dynamically over the years.

  17. Bilateral patching in retinal detachment: fluid mechanics and retinal "settling".

    Science.gov (United States)

    Foster, William J

    2011-07-20

    When a patient suffers a retinal detachment and surgery is delayed, it is known clinically that bilaterally patching the patient may allow the retina to partially reattach or "settle." Although this procedure has been performed since the 1860s, there is still debate as to how such a maneuver facilitates the reattachment of the retina. Finite element calculations using commercially available analysis software are used to elucidate the influence of reduction in eye movement caused by bilateral patching on the flow of subretinal fluid in a physical model of retinal detachment. It was found that by coupling fluid mechanics with structural mechanics, a physically consistent explanation of increased retinal detachment with eye movements can be found in the case of traction on the retinal hole. Large eye movements increase vitreous traction and detachment forces on the edge of the retinal hole, creating a subretinal vacuum and facilitating increased subretinal fluid. Alternative models, in which intraocular fluid flow is redirected into the subretinal space, are not consistent with these simulations. The results of these simulations explain the physical principles behind bilateral patching and provide insight that can be used clinically. In particular, as is known clinically, bilateral patching may facilitate a decrease in the height of a retinal detachment. The results described here provide a description of a physical mechanism underlying this technique. The findings of this study may aid in deciding whether to bilaterally patch patients and in counseling patients on pre- and postoperative care.

  18. Influence of a mobile robot on the spatial behaviour of quail chicks

    Energy Technology Data Exchange (ETDEWEB)

    De Margerie, E; Lumineau, S; Houdelier, C; Richard Yris, M-A, E-mail: emmanuel.demargerie@univ-rennes1.fr [CNRS UMR 6552 Ethologie Animale et Humaine, Universite Rennes 1, Rennes (France)

    2011-09-15

    Quail chicks encountered an autonomous mobile robot during their early development. The robot incorporated a heat source that stimulated following of chicks. The spatial behaviour of grown-up chicks was tested in an exploration test and a detour test. Chicks that grew with the mobile robot exhibited better spatial abilities than chicks grown with a static heat source. We discuss these results in the perspective of animal-robot interaction and of the role of early spatial experience on the behavioural development. (communication)

  19. AUTOMATIC RETINAL VESSEL TORTUOSITY MEASUREMENT

    Directory of Open Access Journals (Sweden)

    Nidhal Khdhair El Abbadi

    2013-01-01

    Full Text Available Retinal vascular vessels have the role to indicate the retinal diseases and for systematic diseases when there are any abnormalities in retinal vascular pattern. A characteristic of the vascular pattern that is appreciated by clinicians is vascular tortuosity, i.e., how curved or kinked a blood vessel, either vein or artery, appears along its course. In this study we suggest a novel mask filter to track the blood vessel along its course and measuring the blood vessels tortuosity over the entire human retinal vessel network in fundus eye image, by using the arc to chord ratio. The suggested algorithm tested with straight and curve hand drawing lines and gives high accurate results.

  20. [Retinal vasculitis in lupic disease].

    Science.gov (United States)

    Brissaud, P; Laroche, L; Krulik, M; Prier, A M; Saraux, H; Canuel, C; Debray, J

    1985-01-01

    Three cases of retinal vasculitis in SLE-type diseases are reported. The first was central retinal vein occlusion occurring during clinical remission of SLE in a 55 year old black female. Prednisone maintenance therapy was unchanged and visual loss rapidly regressed with heparin therapy. The second case was a 33 year old black female in whom SLE was discovered following relapsing bilateral optic neuritis. A progressive visual improvement was obtained with high dose of prednisone (1 mg/kg/day). The third cas was a 17 year old white girl with retinal vasculitis. She had an unclassified connective tissue disease inaugurated by optic neuritis at the age of 10. High dose prednisone (1 mg/kg/day) was effective on the visual loss. Retinal vasculitis lesions in SLE and their therapy are reviewed.

  1. Effects of Senna occidentalis on chick bursa of Fabricius.

    Science.gov (United States)

    Silva, Tereza C; Gorniak, Silvana L; Oloris, Silvia C S; Raspantini, Paulo C; Haraguchi, Mitsue; Dagli, Maria L Z

    2003-12-01

    Senna occidentalis (L) Link (formerly called Cassia occidentalis) is a toxic leguminous plant found ubiquitously as a contaminant of crops. All parts of the plant are toxic, but most of the S. occidentalis toxicity is found in the seeds. S. occidentalis has been shown to be toxic to several animal species, causing degenerative lesions mainly in muscles. This is the first report describing alterations in chick lymphoid organs caused by S. occidentalis seeds. The objectives of this study were to describe the effects of the treatment with seeds and its fraction external tegument (TE) on the development of chicks and their lymphoid organs bursa of Fabricius and spleen. Chicks that received a commercial ration with 1% TE had reduced body and lymphoid organ weights. The bursa of Fabricius presented reduction in the diameters of the follicles, and in the thickness of the cortical and medullary regions. The spleen presented depleted lymphoid tissue in the white pulp. These results indicate that the active principle of S. occidentalis is more concentrated on its TE fraction, and that it can cause weight loss as well as alterations in the lymphoid organs in chicks. The consequences of these alterations should be further investigated.

  2. Comparative Performance Of Broiler Chicks fed Diets Containing ...

    African Journals Online (AJOL)

    Comparative Performance Of Broiler Chicks fed Diets Containing Differently Processed ... A 28-day feeding trial was conducted to determine the effects of dietary inclusion of ... The first batch was soaked in 3% Ca(OH)2 for 48 hours. ... performance of the birds in terms of feed intake, growth rate and feed conversion ratio.

  3. Neurotoxic effect of the dithiocarbamate tecoram on the chick embryo

    NARCIS (Netherlands)

    Steenis, G. van; Logten, M.J. van

    1971-01-01

    Tecoram, when administered at doses of 0.01, 0.1, 1 or 10 mg per egg in propylene glycol or in saline to chick embryos caused paralysis, shortening of the extremities, muscular atrophy, dwarfing and death. Microscopically there were signs of peripheral neuropathy, mainly confined to the distal parts

  4. Safety of West Nile Virus vaccines in sandhill crane chicks

    Science.gov (United States)

    Olsen, G.H.; Miller, K.J.; Docherty, D.E.; Bochsler, V.S.; Folk, Martin J.; Nesbitt, Stephen A.

    2008-01-01

    West Nile virus arrived in North America in 1999 and has spread across the continent in the ensuing years. The virus has proven deadly to a variety of native avian species including sandhill cranes (Grus canadensis). In order to provide safe and efficacious protection for captive and released populations of whooping cranes (G. americana), we have conducted a series of four research projects. The last of these was a study of the effects of two different West Nile virus vaccines on young Florida sandhill crane (G. c. pratensis) chicks and subsequent challenge with the virus. We found that vaccinating crane chicks as early as day 7 post-hatch caused no adverse reactions or noticeable morbidity. We tested both a commercial equine vaccine West Nile - Innovator (Fort Dodge Laboratories, Fort Dodge, Iowa) and a new recombinant DNA vaccine (Centers for Disease Control). We had a 33% mortality in control chicks (n =6) from West Nile virus infection, versus 0% mortality in two groups of vaccinated chicks (n = 12), indicating the two vaccines tested were not only safe but effective in preventing West Nile virus.

  5. Effects of begging on growth rates of nestling chicks

    NARCIS (Netherlands)

    Rodriguez-Girones, MA; Zuniga, JM; Redondo, T

    2001-01-01

    We investigated whether an increase in begging levels delays growth of chicks. In experiment 1, we hand-reared nine pairs of ring dove squabs, divided into a control and a begging group. All squabs received similar amounts of food, but those in the begging group had to beg for a prolonged period in

  6. Embryotoxic effects of crude oil in mallard ducks and chicks

    Science.gov (United States)

    Hoffman, D.J.

    1978-01-01

    Recent studies in this laboratory have revealed that surface applications of microliter amounts of some crude and fuel oils that coat less than 10% of the egg surface reduce hatching considerably in different avian species. Applications of paraffin compounds that coat equal areas of the egg surface do not reduce hatching suggesting that toxicity is due to causes other than asphyxia. In the present study, 1?10 :l of South Louisiana crude oil, an API reference oil, were applied to the surface of fertile mallard (Anas platyrhynchos) and chicken (Gallus gallus) eggs. Early embryolethality was greater in mallard embryos than in chick embryos, but later embryolethality that coincided with the time of rapid outgrowth of the chorioallantoic membrane was more prevalent in chick embryos. The overall incidence of embryolethality was similar in both species. Retardation of growth as reflected by embryonic body weight, crown-rump length, beak length, and general appearance was more pronounced in chick than mallard embryos. Teratogenic defects were more frequent in chick embryos, and incomplete or abnormal ossification of the skull was the most common. External application of equivalent amounts of a mixture of paraffin compounds present in crude oil had virtually no embryotoxic effects in either species, suggesting that other components including aromatic hydrocarbons and organometallics may cause the embryotoxicity.

  7. Artificially Increased Yolk Hormone Levels and Neophobia in Domestic Chicks.

    Science.gov (United States)

    Bertin, Aline; Arnould, Cécile; Moussu, Chantal; Meurisse, Maryse; Constantin, Paul; Leterrier, Christine; Calandreau, Ludovic

    2015-11-30

    In birds there is compelling evidence that the development and expression of behavior is affected by maternal factors, particularly via variation in yolk hormone concentrations of maternal origin. In the present study we tested whether variation in yolk hormone levels lead to variation in the expression of neophobia in young domestic chicks. Understanding how the prenatal environment could predispose chicks to express fear-related behaviors is essential in order to propose preventive actions and improve animal welfare. We simulated the consequences of a maternal stress by experimentally enhancing yolk progesterone, testosterone and estradiol concentrations in hen eggs prior to incubation. The chicks from these hormone-treated eggs (H) and from sham embryos (C) that received the vehicle-only were exposed to novel food, novel object and novel environment tests. H chicks approached a novel object significantly faster and were significantly more active in a novel environment than controls, suggesting less fearfulness. Conversely, no effect of the treatment was found in food neophobia tests. Our study highlights a developmental influence of yolk hormones on a specific aspect of neophobia. The results suggest that increased yolk hormone levels modulate specifically the probability of exploring novel environments or novel objects in the environment.

  8. Artificially Increased Yolk Hormone Levels and Neophobia in Domestic Chicks

    Directory of Open Access Journals (Sweden)

    Aline Bertin

    2015-11-01

    Full Text Available In birds there is compelling evidence that the development and expression of behavior is affected by maternal factors, particularly via variation in yolk hormone concentrations of maternal origin. In the present study we tested whether variation in yolk hormone levels lead to variation in the expression of neophobia in young domestic chicks. Understanding how the prenatal environment could predispose chicks to express fear-related behaviors is essential in order to propose preventive actions and improve animal welfare. We simulated the consequences of a maternal stress by experimentally enhancing yolk progesterone, testosterone and estradiol concentrations in hen eggs prior to incubation. The chicks from these hormone-treated eggs (H and from sham embryos (C that received the vehicle-only were exposed to novel food, novel object and novel environment tests. H chicks approached a novel object significantly faster and were significantly more active in a novel environment than controls, suggesting less fearfulness. Conversely, no effect of the treatment was found in food neophobia tests. Our study highlights a developmental influence of yolk hormones on a specific aspect of neophobia. The results suggest that increased yolk hormone levels modulate specifically the probability of exploring novel environments or novel objects in the environment.

  9. Effects of begging on growth rates of nestling chicks

    NARCIS (Netherlands)

    Rodriguez-Girones, MA; Zuniga, JM; Redondo, T

    2001-01-01

    We investigated whether an increase in begging levels delays growth of chicks. In experiment 1, we hand-reared nine pairs of ring dove squabs, divided into a control and a begging group. All squabs received similar amounts of food, but those in the begging group had to beg for a prolonged period in

  10. Retinal prosthesis for the blind.

    Science.gov (United States)

    Margalit, Eyal; Maia, Mauricio; Weiland, James D; Greenberg, Robert J; Fujii, Gildo Y; Torres, Gustavo; Piyathaisere, Duke V; O'Hearn, Thomas M; Liu, Wentai; Lazzi, Gianluca; Dagnelie, Gislin; Scribner, Dean A; de Juan, Eugene; Humayun, Mark S

    2002-01-01

    Most of current concepts for a visual prosthesis are based on neuronal electrical stimulation at different locations along the visual pathways within the central nervous system. The different designs of visual prostheses are named according to their locations (i.e., cortical, optic nerve, subretinal, and epiretinal). Visual loss caused by outer retinal degeneration in diseases such as retinitis pigmentosa or age-related macular degeneration can be reversed by electrical stimulation of the retina or the optic nerve (retinal or optic nerve prostheses, respectively). On the other hand, visual loss caused by inner or whole thickness retinal diseases, eye loss, optic nerve diseases (tumors, ischemia, inflammatory processes etc.), or diseases of the central nervous system (not including diseases of the primary and secondary visual cortices) can be reversed by a cortical visual prosthesis. The intent of this article is to provide an overview of current and future concepts of retinal and optic nerve prostheses. This article will begin with general considerations that are related to all or most of visual prostheses and then concentrate on the retinal and optic nerve designs. The authors believe that the field has grown beyond the scope of a single article so cortical prostheses will be described only because of their direct effect on the concept and technical development of the other prostheses, and this will be done in a more general and historic perspective.

  11. Retinal implants: a systematic review.

    Science.gov (United States)

    Chuang, Alice T; Margo, Curtis E; Greenberg, Paul B

    2014-07-01

    Retinal implants present an innovative way of restoring sight in degenerative retinal diseases. Previous reviews of research progress were written by groups developing their own devices. This systematic review objectively compares selected models by examining publications describing five representative retinal prostheses: Argus II, Boston Retinal Implant Project, Epi-Ret 3, Intelligent Medical Implants (IMI) and Alpha-IMS (Retina Implant AG). Publications were analysed using three criteria for interim success: clinical availability, vision restoration potential and long-term biocompatibility. Clinical availability: Argus II is the only device with FDA approval. Argus II and Alpha-IMS have both received the European CE Marking. All others are in clinical trials, except the Boston Retinal Implant, which is in animal studies. Vision restoration: resolution theoretically correlates with electrode number. Among devices with external cameras, the Boston Retinal Implant leads with 100 electrodes, followed by Argus II with 60 electrodes and visual acuity of 20/1262. Instead of an external camera, Alpha-IMS uses a photodiode system dependent on natural eye movements and can deliver visual acuity up to 20/546. Long-term compatibility: IMI offers iterative learning; Epi-Ret 3 is a fully intraocular device; Alpha-IMS uses intraocular photosensitive elements. Merging the results of these three criteria, Alpha-IMS is the most likely to achieve long-term success decades later, beyond current clinical availability.

  12. Filling in the retinal image

    Science.gov (United States)

    Larimer, James; Piantanida, Thomas

    1990-01-01

    The optics of the eye form an image on a surface at the back of the eyeball called the retina. The retina contains the photoreceptors that sample the image and convert it into a neural signal. The spacing of the photoreceptors in the retina is not uniform and varies with retinal locus. The central retinal field, called the macula, is densely packed with photoreceptors. The packing density falls off rapidly as a function of retinal eccentricity with respect to the macular region and there are regions in which there are no photoreceptors at all. The retinal regions without photoreceptors are called blind spots or scotomas. The neural transformations which convert retinal image signals into percepts fills in the gaps and regularizes the inhomogeneities of the retinal photoreceptor sampling mosaic. The filling-in mechamism plays an important role in understanding visual performance. The filling-in mechanism is not well understood. A systematic collaborative research program at the Ames Research Center and SRI in Menlo Park, California, was designed to explore this mechanism. It was shown that the perceived fields which are in fact different from the image on the retina due to filling-in, control some aspects of performance and not others. Researchers have linked these mechanisms to putative mechanisms of color coding and color constancy.

  13. The mechanics of retinal detachment

    Science.gov (United States)

    Chou, Tom; Siegel, Michael

    2013-03-01

    We present a model of the mechanical and fluid forces associated with exudative retinal detachments where the retinal photoreceptor cells separate typically from the underlying retinal pigment epithelium (RPE). By computing the total fluid volume flow arising from transretinal, vascular, and retinal pigment epithelium (RPE) pump currents, we determine the conditions under which the subretinal fluid pressure exceeds the maximum yield stress holding the retina and RPE together, giving rise to an irreversible, extended retinal delamination. We also investigate localized, blister-like retinal detachments by balancing mechanical tension in the retina with both the retina-RPE adhesion energy and the hydraulic pressure jump across the retina. For detachments induced by traction forces, we find a critical radius beyond which the blister is unstable to growth. Growth of a detached blister can also be driven by inflamed tissue within which e.g., the hydraulic conductivities of the retina or choroid increase, the RPE pumps fail, or the adhesion properties change. We determine the parameter regimes in which the blister either becomes unstable to growth, remains stable and finite-sized, or shrinks, allowing possible healing. This work supported by the Army Research Office through grant 58386MA

  14. Heritability of Retinal Vascular Fractals

    DEFF Research Database (Denmark)

    Vergmann, Anna Stage; Broe, Rebecca; Kessel, Line

    2017-01-01

    Purpose: To determine the genetic contribution to the pattern of retinal vascular branching expressed by its fractal dimension. Methods: This was a cross-sectional study of 50 monozygotic and 49 dizygotic, same-sex twin pairs aged 20 to 46 years. In 50°, disc-centered fundus photographs, the reti......Purpose: To determine the genetic contribution to the pattern of retinal vascular branching expressed by its fractal dimension. Methods: This was a cross-sectional study of 50 monozygotic and 49 dizygotic, same-sex twin pairs aged 20 to 46 years. In 50°, disc-centered fundus photographs......, the retinal vascular fractal dimension was measured using the box-counting method and compared within monozygotic and dizygotic twin pairs using Pearson correlation coefficients. Falconer's formula and quantitative genetic models were used to determine the genetic component of variation. Results: The mean......, the branching pattern of the retinal vessels demonstrated a higher structural similarity in monozygotic than in dizygotic twin pairs. The retinal vascular fractal dimension was mainly determined by genetic factors, which accounted for 54% of the variation. The genetically predetermination of the retinal...

  15. Activity of protein kinase C during the differentiation of chick limb bud mesenchymal cells.

    Science.gov (United States)

    Sonn, J K; Solursh, M

    1993-07-01

    To investigate the relationship between protein kinase C (PKC) and chondrogenesis, PKC activity was assayed in cultures of stage 23/24 chick limb bud mesenchymal cells under various conditions. PKC activities of cytosolic and particulate fractions were low in 1 day cultured cells. As chondrogenesis proceeds, cytosolic PKC activity increased more than twofold, while that of the particulate fraction increased only slightly. Three days' treatment of cultures with phorbol-12-myristate-13-acetate (PMA, 5 x 10(-8) M) inhibited chondrogenesis judged by the accumulation of Alcian blue bound to the extracellular matrix and depressed PKC activity in cytosolic fraction. When cells were grown for 3 days in control medium after 3 days' treatment with PMA, chondrogenesis resumed and PKC activity recovered to normal values. PKC activity in cultures plated at low density (5 x 10(6) cells/ml) where chondrogenesis is reduced was as low as that in 1 day cultured cells plated at high density (2 x 10(7) cells/ml) or that in PMA treated cells. On the other hand, staurosporine promoted chondrogenesis without affecting PKC activity. Furthermore, reversal of PMA's inhibitory effect on chondrogenesis by staurosporine was not accompanied by recovery of PKC activity. These data indicate that increases in PKC activity is closely related to chondrogenesis and that PMA inhibits chondrogenesis by depressing PKC. However, staurosporine's enhancing effect on chondrogenesis is not related to PKC activity.

  16. Determination of retinal surface area.

    Science.gov (United States)

    Nagra, Manbir; Gilmartin, Bernard; Thai, Ngoc Jade; Logan, Nicola S

    2017-09-01

    Previous attempts at determining retinal surface area and surface area of the whole eye have been based upon mathematical calculations derived from retinal photographs, schematic eyes and retinal biopsies of donor eyes. 3-dimensional (3-D) ocular magnetic resonance imaging (MRI) allows a more direct measurement, it can be used to image the eye in vivo, and there is no risk of tissue shrinkage. The primary purpose of this study is to compare, using T2-weighted 3D MRI, retinal surface areas for superior-temporal (ST), inferior-temporal (IT), superior-nasal (SN) and inferior-nasal (IN) retinal quadrants. An ancillary aim is to examine whether inter-quadrant variations in area are concordant with reported inter-quadrant patterns of susceptibility to retinal breaks associated with posterior vitreous detachment (PVD). Seventy-three adult participants presenting without retinal pathology (mean age 26.25 ± 6.06 years) were scanned using a Siemens 3-Tesla MRI scanner to provide T2-weighted MR images that demarcate fluid-filled internal structures for the whole eye and provide high-contrast delineation of the vitreous-retina interface. Integrated MRI software generated total internal ocular surface area (TSA). The second nodal point was used to demarcate the origin of the peripheral retina in order to calculate total retinal surface area (RSA) and quadrant retinal surface areas (QRSA) for ST, IT, SN, and IN quadrants. Mean spherical error (MSE) was -2.50 ± 4.03D and mean axial length (AL) 24.51 ± 1.57 mm. Mean TSA and RSA for the RE were 2058 ± 189 and 1363 ± 160 mm(2) , respectively. Repeated measures anova for QRSA data indicated a significant difference within-quadrants (P area/mm increase in AL. Although the differences between QRSAs are relatively small, there was evidence of concordance with reported inter-quadrant patterns of susceptibility to retinal breaks associated with PVD. The data allow AL to be converted to QRSAs, which will assist further

  17. ACUTE RETINAL ARTERIAL OCCLUSIVE DISORDERS

    Science.gov (United States)

    Hayreh, Sohan Singh

    2011-01-01

    The initial section deals with basic sciences; among the various topics briefly discussed are the anatomical features of ophthalmic, central retinal and cilioretinal arteries which may play a role in acute retinal arterial ischemic disorders. Crucial information required in the management of central retinal artery occlusion (CRAO) is the length of time the retina can survive following that. An experimental study shows that CRAO for 97 minutes produces no detectable permanent retinal damage but there is a progressive ischemic damage thereafter, and by 4 hours the retina has suffered irreversible damage. In the clinical section, I discuss at length various controversies on acute retinal arterial ischemic disorders. Classification of acute retinal arterial ischemic disorders These are of 4 types: CRAO, branch retinal artery occlusion (BRAO), cotton wools spots and amaurosis fugax. Both CRAO and BRAO further comprise multiple clinical entities. Contrary to the universal belief, pathogenetically, clinically and for management, CRAO is not one clinical entity but 4 distinct clinical entities – non-arteritic CRAO, non-arteritic CRAO with cilioretinal artery sparing, arteritic CRAO associated with giant cell arteritis (GCA) and transient non-arteritic CRAO. Similarly, BRAO comprises permanent BRAO, transient BRAO and cilioretinal artery occlusion (CLRAO), and the latter further consists of 3 distinct clinical entities - non-arteritic CLRAO alone, non-arteritic CLRAO associated with central retinal vein occlusion and arteritic CLRAO associated with GCA. Understanding these classifications is essential to comprehend fully various aspects of these disorders. Central retinal artery occlusion The pathogeneses, clinical features and management of the various types of CRAO are discussed in detail. Contrary to the prevalent belief, spontaneous improvement in both visual acuity and visual fields does occur, mainly during the first 7 days. The incidence of spontaneous visual

  18. Integration of human model neurons (NT2) into embryonic chick nervous system.

    Science.gov (United States)

    Podrygajlo, Grzegorz; Wiegreffe, Christoph; Scaal, Martin; Bicker, Gerd

    2010-02-01

    Postmitotic neurons were generated from the human NT2 teratocarcinoma cell line in a novel cell aggregate differentiation procedure. Approximately a third of the differentiated neurons expressed cell markers related to cholinergic neurotransmission. To examine whether this human cell model system can be directed toward a motoneuronal fate, postmitotic neurons were co-cultured with mouse myotubes. Outgrowing neuronal processes established close contact with the myotubes and formed neuromuscular junction-like structures that bound alpha-bungarotoxin. To determine how grafted precursor cells and neurons respond to embryonic nerve tissue, NT2 cells at different stages of neural development were injected into chick embryo neural tube and brain. Grafted NT2 neurons populated both parts of the nervous system, sometimes migrating away from the site of injection. The neural tube appeared to be more permissive for neurite extensions than the brain. Moreover, extending neurites of spinal grafts were approaching the ventral roots, thus resembling motoneuronal projections.

  19. Tyro3 Modulates Mertk-Associated Retinal Degeneration.

    Science.gov (United States)

    Vollrath, Douglas; Yasumura, Douglas; Benchorin, Gillie; Matthes, Michael T; Feng, Wei; Nguyen, Natalie M; Sedano, Cecilia D; Calton, Melissa A; LaVail, Matthew M

    2015-12-01

    Inherited photoreceptor degenerations (IPDs) are the most genetically heterogeneous of Mendelian diseases. Many IPDs exhibit substantial phenotypic variability, but the basis is usually unknown. Mutations in MERTK cause recessive IPD phenotypes associated with the RP38 locus. We have identified a murine genetic modifier of Mertk-associated photoreceptor degeneration, the C57BL/6 (B6) allele of which acts as a suppressor. Photoreceptors degenerate rapidly in Mertk-deficient animals homozygous for the 129P2/Ola (129) modifier allele, whereas animals heterozygous for B6 and 129 modifier alleles exhibit an unusual intermixing of degenerating and preserved retinal regions, with females more severely affected than males. Mertk-deficient mice homozygous for the B6 modifier allele display degeneration only in the far periphery, even at 8 months of age, and have improved retinal function compared to animals homozygous for the 129 allele. We genetically mapped the modifier to an approximately 2-megabase critical interval that includes Tyro3, a paralog of Mertk. Tyro3 expression in the outer retina varies with modifier genotype in a manner characteristic of a cis-acting expression quantitative trait locus (eQTL), with the B6 allele conferring an approximately three-fold higher expression level. Loss of Tyro3 function accelerates the pace of photoreceptor degeneration in Mertk knockout mice, and TYRO3 protein is more abundant in the retinal pigment epithelium (RPE) adjacent to preserved central retinal regions of Mertk knockout mice homozygous for the B6 modifier allele. Endogenous human TYRO3 protein co-localizes with nascent photoreceptor outer segment (POS) phagosomes in a primary RPE cell culture assay, and expression of murine Tyro3 in cultured cells stimulates phagocytic ingestion of POS. Our findings demonstrate that Tyro3 gene dosage modulates Mertk-associated retinal degeneration, provide strong evidence for a direct role for TYRO3 in RPE phagocytosis, and suggest

  20. Tyro3 Modulates Mertk-Associated Retinal Degeneration.

    Directory of Open Access Journals (Sweden)

    Douglas Vollrath

    2015-12-01

    Full Text Available Inherited photoreceptor degenerations (IPDs are the most genetically heterogeneous of Mendelian diseases. Many IPDs exhibit substantial phenotypic variability, but the basis is usually unknown. Mutations in MERTK cause recessive IPD phenotypes associated with the RP38 locus. We have identified a murine genetic modifier of Mertk-associated photoreceptor degeneration, the C57BL/6 (B6 allele of which acts as a suppressor. Photoreceptors degenerate rapidly in Mertk-deficient animals homozygous for the 129P2/Ola (129 modifier allele, whereas animals heterozygous for B6 and 129 modifier alleles exhibit an unusual intermixing of degenerating and preserved retinal regions, with females more severely affected than males. Mertk-deficient mice homozygous for the B6 modifier allele display degeneration only in the far periphery, even at 8 months of age, and have improved retinal function compared to animals homozygous for the 129 allele. We genetically mapped the modifier to an approximately 2-megabase critical interval that includes Tyro3, a paralog of Mertk. Tyro3 expression in the outer retina varies with modifier genotype in a manner characteristic of a cis-acting expression quantitative trait locus (eQTL, with the B6 allele conferring an approximately three-fold higher expression level. Loss of Tyro3 function accelerates the pace of photoreceptor degeneration in Mertk knockout mice, and TYRO3 protein is more abundant in the retinal pigment epithelium (RPE adjacent to preserved central retinal regions of Mertk knockout mice homozygous for the B6 modifier allele. Endogenous human TYRO3 protein co-localizes with nascent photoreceptor outer segment (POS phagosomes in a primary RPE cell culture assay, and expression of murine Tyro3 in cultured cells stimulates phagocytic ingestion of POS. Our findings demonstrate that Tyro3 gene dosage modulates Mertk-associated retinal degeneration, provide strong evidence for a direct role for TYRO3 in RPE phagocytosis

  1. Central retinal vessel blood flow after surgical treatment for central retinal vein occlusion.

    NARCIS (Netherlands)

    Crama, N.; Gualino, V.; Restori, M.; Charteris, D.G.

    2010-01-01

    PURPOSE: The purpose of this study was to determine the effect of radial optic neurotomy and retinal endovascular surgery on retinal blood flow velocity in patients with central retinal vein occlusion. METHODS: A prospective interventional case series. RESULTS: Six patients with a central retinal

  2. The role of Zic family zinc finger transcription factors in the proliferation and differentiation of retinal progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Watabe, Yui [Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo (Japan); Department of Ophthalmology, Teikyo University School of Medicine, Tokyo (Japan); Division of Orthoptics, Teikyo University School of Medical Care and Technology, Tokyo (Japan); Baba, Yukihiro [Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo (Japan); Nakauchi, Hiromitsu [Division of Stem Cell Therapy, Center for Stem Cell Biology and Regenerative Medicine, Institute of Medical Science, University of Tokyo (Japan); Mizota, Atsushi [Department of Ophthalmology, Teikyo University School of Medicine, Tokyo (Japan); Watanabe, Sumiko, E-mail: sumiko@ims.u-tokyo.ac.jp [Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo (Japan)

    2011-11-11

    Highlights: Black-Right-Pointing-Pointer Zic transcription factors expressed early retinal progenitor cells. Black-Right-Pointing-Pointer Zics sustain proliferation activity of retinal progenitor cells. Black-Right-Pointing-Pointer Overexpression of Zic in retinal progenitors perturbed rod differentiation. Black-Right-Pointing-Pointer Fate determination to rod photoreceptor was not affected. -- Abstract: Members of the Zic family of zinc finger transcription factors play critical roles in a variety of developmental processes. Using DNA microarray analysis, we found that Zics are strongly expressed in SSEA-1-positive early retinal progenitors in the peripheral region of the mouse retina. Reverse-transcription polymerase chain reaction using mRNA from the retina at various developmental stages showed that Zic1 and Zic2 are expressed in the embryonic retina and then gradually disappear during retinal development. Zic3 is also expressed in the embryonic retina; its expression level slightly decreases but it is expressed until adulthood. We overexpressed Zic1, Zic2, or Zic3 in retinal progenitors at embryonic day 17.5 and cultured the retina as explants for 2 weeks. The number of rod photoreceptors was fewer than in the control, but no other cell types showed significant differences between control and Zic overexpressing cells. The proliferation activity of normal retinal progenitors decreased after 5 days in culture, as observed in normal in vivo developmental processes. However, Zic expressing retinal cells continued to proliferate at days 5 and 7, suggesting that Zics sustain the proliferation activities of retinal progenitor cells. Since the effects of Zic1, 2, and 3 are indistinguishable in terms of differentiation and proliferation of retinal progenitors, the redundant function of Zics in retinal development is suggested.

  3. [Congenital retinal folds in different clinical cases].

    Science.gov (United States)

    Munteanu, M

    2005-01-01

    We present 12 clinical cases of congenital retinal folds with different etiologies: posterior primitive vitreous persistency and hyperplasia (7 cases),retinocytoma (1 case). retinopathy of prematurity (1 case), astrocytoma of the retina (1 case), retinal vasculitis (1 case), Goldmann-Favre syndrome (1 case). Etiopathogenic and nosological aspects are discussed; the congenital retinal folds are interpreted as a symptom in a context of a congenital or acquired vitreo-retinal pathology.

  4. Distribution, markers and functions of retinal microglia

    NARCIS (Netherlands)

    Chen, L.; Yang, P.Z.; Kijlstra, A.

    2002-01-01

    Retinal microglia originate from hemopoietic cells and invade the retina from the retinal margin and the optic disc, most likely via the blood vessels of the ciliary body and iris, and the retinal vasculature, respectively. The microglial precursors that appear in the retina prior to vascularization

  5. Choroidal melanoma clinically simulating a retinal angioma

    Energy Technology Data Exchange (ETDEWEB)

    Shields, J.A.; Joffe, L.; Guibor, P.

    1978-01-01

    An amelanotic fundus lesion in a 35-year-old man was associated with a dilated retinal vessel, thus suggesting the diagnosis of retinal angioma. Fluorescein angiography and B-scan ultrasonography were not diagnostic, but a radioactive phosphorus uptake test suggested the lesion was malignant. The enucleated globe showed a malignant choroidal melanoma drained by a large retinal vein.

  6. Choroidal melanoma clinically simulating a retinal angioma.

    Science.gov (United States)

    Shields, J A; Joffe, L; Guibor, P

    1978-01-01

    An amelanotic fundus lesion in a 35-year-old man was associated with a dilated retinal vessel, thus suggesting the diagnosis of retinal angioma. Fluorescein angiography and B-scan ultrasonography were not diagnostic, but a radioactive phosphorus uptake test suggested the lesion was malignant. The enucleated globe showed a malignant choroidal melanoma drained by a large retinal vein.

  7. Noninvasive Retinal Markers in Diabetic Retinopathy

    DEFF Research Database (Denmark)

    Blindbæk, Søren Leer; Torp, Thomas Lee; Lundberg, Kristian

    2017-01-01

    The retinal vascular system is the only part of the human body available for direct, in vivo inspection. Noninvasive retinal markers are important to identity patients in risk of sight-threatening diabetic retinopathy. Studies have correlated structural features like retinal vascular caliber and ...

  8. Exploring the retinal connectome

    Science.gov (United States)

    Anderson, James R.; Jones, Bryan W.; Watt, Carl B.; Shaw, Margaret V.; Yang, Jia-Hui; DeMill, David; Lauritzen, James S.; Lin, Yanhua; Rapp, Kevin D.; Mastronarde, David; Koshevoy, Pavel; Grimm, Bradley; Tasdizen, Tolga; Whitaker, Ross

    2011-01-01

    Purpose A connectome is a comprehensive description of synaptic connectivity for a neural domain. Our goal was to produce a connectome data set for the inner plexiform layer of the mammalian retina. This paper describes our first retinal connectome, validates the method, and provides key initial findings. Methods We acquired and assembled a 16.5 terabyte connectome data set RC1 for the rabbit retina at ≈2 nm resolution using automated transmission electron microscope imaging, automated mosaicking, and automated volume registration. RC1 represents a column of tissue 0.25 mm in diameter, spanning the inner nuclear, inner plexiform, and ganglion cell layers. To enhance ultrastructural tracing, we included molecular markers for 4-aminobutyrate (GABA), glutamate, glycine, taurine, glutamine, and the in vivo activity marker, 1-amino-4-guanidobutane. This enabled us to distinguish GABAergic and glycinergic amacrine cells; to identify ON bipolar cells coupled to glycinergic cells; and to discriminate different kinds of bipolar, amacrine, and ganglion cells based on their molecular signatures and activity. The data set was explored and annotated with Viking, our multiuser navigation tool. Annotations were exported to additional applications to render cells, visualize network graphs, and query the database. Results Exploration of RC1 showed that the 2 nm resolution readily recapitulated well known connections and revealed several new features of retinal organization: (1) The well known AII amacrine cell pathway displayed more complexity than previously reported, with no less than 17 distinct signaling modes, including ribbon synapse inputs from OFF bipolar cells, wide-field ON cone bipolar cells and rod bipolar cells, and extensive input from cone-pathway amacrine cells. (2) The axons of most cone bipolar cells formed a distinct signal integration compartment, with ON cone bipolar cell axonal synapses targeting diverse cell types. Both ON and OFF bipolar cells receive

  9. Glutamine synthetase localization in cortisol-induced chick embryo retinas

    OpenAIRE

    1980-01-01

    We report here for the first time, in chick retina, Muller cell localization of glutamine synthetase (GS) activity by an immunohistochemical technique, in agreement with previous reports of glial localization of this enzyme in rat brain and retina. Age- dependent changes in the endogenous enzyme activity as well as cortisol- induced changes in GS activity, both in ovo and in vitro, measured biochemically, reflect the changes observed by staining.

  10. Interactions among dietary boron, molybdenum, and magnesium in the chick

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, C.D.; Nielsen, F.H.

    1986-03-01

    The authors have previously reported that dietary B affects plasma Mo concentrations in chicks fed inadequate levels of Mg and cholecalciferol (vit. D/sub 3/). Because of this finding, they studied the effect of dietary Mo and Mg on the signs of B deficiency in vit. D/sub 3/ deprived chicks. In a fully crossed, 2 x 2 x 2 factorially arranged experiment, day-old cockerel chicks (19 per group) were fed a ground corn-casein-corn oil based diet (containing 0.850 mg B, 0.319 mg Mo, and 125 IU vit. D/sub 3//kg) supplemented with B at 0 or 3 mg/kg, Mo at 0 or 20 mg/kg, and Mg at 300 or 500 mg/kg. After four weeks, B deprivation depressed growth and elevated the plasma glucose and the brain wt/body wt ratio. Low dietary Mo elevated the heart wt/body wt ratio. An interaction between B and Mg affected hemoglobin and plasma alkaline phosphatase and an interaction between B and Mo affected the heart wt/body wt and liver wt/body wt ratios. Mg deficiency gave usual signs including depressed growth, plasma alkaline phosphatase, glucose, and spleen and liver wt/body wt ratios and elevated hematocrit and brain wt/body wt ratio. The findings suggest that physiological levels of Mg and Mo affect B metabolism. The effects of low dietary Mo on vit. D/sub 3/ and/or Mg-deficient chicks needs to be elucidated.

  11. Time required to protect the intestinal tract of chicks against Salmonella enterica serovar enteritidis using competitive exclusion

    Directory of Open Access Journals (Sweden)

    EV Sterzo

    2005-06-01

    Full Text Available Competitive exclusion (CE has been designed to accelerate the colonization of the alimentary tract of young commercial birds and it has been also used to repopulate the digestive tract after antibiotic therapy. The method has been successfully adopted as a means to prevent enteric salmonellosis. The present study was carried out to evaluate if CE is able to prevent this kind of infection. Newly hatched chicks were given a CE culture and at different intervals of time birds infected with Salmonella Enteritidis were placed together with the group of treated birds. CE culture was prepared from feces of adult laying hens incubated overnight at 37C under aerobic conditions. Birds were killed 4 and 8 days after challenge and viable counts of Salmonella Enteritidis were assessed in the cecal contents. The results showed that Salmonella infection was reduced even if CE culture administration was concomitant with the inclusion of the infected bird in the group.

  12. Retinal Optical Coherence Tomography Imaging

    Science.gov (United States)

    Drexler, Wolfgang; Fujimoto, James G.

    The eye is essentially transparent, transmitting light with only minimal optical attenuation and scattering providing easy optical access to the anterior segment as well as the retina. For this reason, ophthalmic and especially retinal imaging has been not only the first but also most successful clinical application for optical coherence tomography (OCT). This chapter focuses on the development of OCT technology for retinal imaging. OCT has significantly improved the potential for early diagnosis, understanding of retinal disease pathogenesis, as well as monitoring disease progression and response to therapy. Development of ultrabroad bandwidth light sources and high-speed detection techniques has enabled significant improvements in ophthalmic OCT imaging performance, demonstrating the potential of three-dimensional, ultrahigh-resolution OCT (UHR OCT) to perform noninvasive optical biopsy of the living human retina, i.e., the in vivo visualization of microstructural, intraretinal morphology in situ approaching the resolution of conventional histopathology. Significant improvements in axial resolution and speed not only enable three-dimensional rendering of retinal volumes but also high-definition, two-dimensional tomograms, topographic thickness maps of all major intraretinal layers, as well as volumetric quantification of pathologic intraretinal changes. These advances in OCT technology have also been successfully applied in several animal models of retinal pathologies. The development of light sources emitting at alternative wavelengths, e.g., around #1,060 nm, not only enabled three-dimensional OCT imaging with enhanced choroidal visualization but also improved OCT performance in cataract patients due to reduced scattering losses in this wavelength region. Adaptive optics using deformable mirror technology, with unique high stroke to correct higher-order ocular aberrations, with specially designed optics to compensate chromatic aberration of the human eye, in

  13. [Evaluation of Antilles fish ciguatoxicity by mouse and chick bioassays].

    Science.gov (United States)

    Pottier, I; Vernoux, J P

    2003-03-01

    Ciguatera is a common seafood poisoning in Western Atlantic and French West Indies. Ciguatera fish poisoning in the Caribbean is a public health problem. A toxicological study was carried out on 178 Caribbean fish specimens (26 species) captured off Guadeloupe and Saint Barthelemy between 1993 and 1999. The mouse bioassay and the chick feeding test were used to control fish edibility. Ciguatoxins presence was assumed when symptomatology was typical of ciguatera in mouse and chick. Fishes were classified in three groups: non toxic fish (edible), low toxic fish (not edible) and toxic fish (not edible). 75% of fishes were non toxic. Toxic fish specimens belonged to four families of high trophic level carnivores: Carangidae, Lutjanidae, Serranidae et Sphyraenidae. Percentages of toxic fishes to humans reached 55% for Caranx latus and 33% for Caranx bartholomaei and Caranx lugubris. Only a significant correlation between weight and toxicity was only found for C. latus and snappers. Small carnivorous groupers (Serranidae) were also toxic. Atoxic fish species were (a) pelagic fish (Coryphaena hippurus, Auxis thazard and Euthynnus pelamis), (b) invertebrates feeders (Malacanthus plumieri, Balistes vetula), (c) small high-risk fish or (d) fish of edible benthic fish families. Liver of four fishes (Mycteroperca venenosa, Caranx bartholomaei, Seriola rivoliana, Gymnothorax funebris) contained ciguatoxins at a significant level although their flesh was safe. This study confirms the usefulness of mouse and chick bioassays for sanitary control of fish.

  14. Introduction of DT40 cells into chick embryos

    Institute of Scientific and Technical Information of China (English)

    Mariko Toba; Fumio Ebara; Hiroki Furuta; Yuichi Matsushimal; Yasuo Kitagawa; Noboru Fujihara

    2001-01-01

    To examine the transfection of exogenous genes into chick embryos, applying the characteristics of avian leukosis virus (ALV)-induced chicken B cell line DT40 to the production of chimeric birds. Methods: The DT40cells incorporated with exogenous gene (lacZ constructs encoding Escherichia coli β-galactosidase: β-gal) were introduced into chick embryos by the injection of cells into stage X blastoderm. Manipulated eggs were incubated for 3 (trial 1 ) or 6 (trial 2) days, and the expression of lacZ DNA was detected by a histochemical staining method of β-galactosidase and polymerase chain reaction (PCR) analysis. Results: The survival rates of the manipulated embryos incubated for 3 days (stage 18-20: trial 1) and 6 days (stage 28, 30: trial 2) were about 42% and 38%, respectively.The expression rates of the lacZ gene in the embryos in the trials 1 and 2 were about 60% and 23%, respectively, for the survived embryos. Conclusio: The rate of embryonic viability and expression rate of introduced genes were not so high, but it suggested the possibility of utilizing the DT40 cells as a vector for carrying exogenous genes into chick embryos.

  15. Central administration of neuromedin U suppresses food intake in chicks.

    Science.gov (United States)

    Kamisoyama, Hiroshi; Honda, Kazuhisa; Saneyasu, Takaoki; Sugahara, Kunio; Hasegawa, Shin

    2007-06-08

    The appetite-suppressive action of brain-gut peptides is similar in both chickens and mammals. In mammals, the brain-gut peptide neuromedin U (NMU) suppresses food intake via hypothalamic neuropeptides, corticotropin-releasing factor (CRF), oxytocin, and arginine-vasopressin. In chickens, central administration of CRF, oxytocin, or arginine-vasotocin (AVT, a nonmammalian equivalent of arginine-vasopressin) suppresses food intake. However, the anorexigenic action of NMU in chickens has not yet been identified. In the present study, we analyzed the effects of the central administration of NMU on food intake and hypothalamic mRNA levels of CRF, AVT and mesotocin (a nonmammalian equivalent of oxytocin) in chicks. Intracerebroventricular administration of NMU in chicks significantly suppressed food intake and induced wing-flapping behavior. NMU also significantly upregulated mRNA expression of CRF and AVT, but did not influence mRNA expression of mesotocin in the hypothalamus. These results suggest that NMU functions as an appetite-suppressive peptide via CRF and AVT in the central nervous system in chicks.

  16. Excess caffeine exposure impairs eye development during chick embryogenesis

    Science.gov (United States)

    Ma, Zheng-lai; Wang, Guang; Cheng, Xin; Chuai, Manli; Kurihara, Hiroshi; Lee, Kenneth Ka Ho; Yang, Xuesong

    2014-01-01

    Caffeine has been an integral component of our diet and medicines for centuries. It is now known that over consumption of caffeine has detrimental effects on our health, and also disrupts normal foetal development in pregnant mothers. In this study, we investigated the potential teratogenic effect of caffeine over-exposure on eye development in the early chick embryo. Firstly, we demonstrated that caffeine exposure caused chick embryos to develop asymmetrical microphthalmia and induced the orbital bone to develop abnormally. Secondly, caffeine exposure perturbed Pax6 expression in the retina of the developing eye. In addition, it perturbed the migration of HNK-1+ cranial neural crest cells. Pax6 is an important gene that regulates eye development, so altering the expression of this gene might be the cause for the abnormal eye development. Thirdly, we found that reactive oxygen species (ROS) production was significantly increased in eye tissues following caffeine treatment, and that the addition of anti-oxidant vitamin C could rescue the eyes from developing abnormally in the presence of caffeine. This suggests that excess ROS induced by caffeine is one of the mechanisms involved in the teratogenic alterations observed in the eye during embryogenesis. In sum, our experiments in the chick embryo demonstrated that caffeine is a potential teratogen. It causes asymmetrical microphthalmia to develop by increasing ROS production and perturbs Pax6 expression. PMID:24636305

  17. Phloroglucinol protects retinal pigment epithelium and photoreceptor against all-trans-retinal-induced toxicity and inhibits A2E formation.

    Science.gov (United States)

    Cia, David; Cubizolle, Aurélie; Crauste, Céline; Jacquemot, Nathalie; Guillou, Laurent; Vigor, Claire; Angebault, Claire; Hamel, Christian P; Vercauteren, Joseph; Brabet, Philippe

    2016-09-01

    Among retinal macular diseases, the juvenile recessive Stargardt disease and the age-related degenerative disease arise from carbonyl and oxidative stresses (COS). Both stresses originate from an accumulation of all-trans-retinal (atRAL) and are involved in bisretinoid formation by condensation of atRAL with phosphatidylethanolamine (carbonyl stress) in the photoreceptor and its transformation into lipofuscin bisretinoids (oxidative stress) in the retinal pigment epithelium (RPE). As atRAL and bisretinoid accumulation contribute to RPE and photoreceptor cell death, our goal is to select powerful chemical inhibitors of COS. Here, we describe that phloroglucinol, a natural phenolic compound having anti-COS properties, protects both rat RPE and mouse photoreceptor primary cultures from atRAL-induced cell death and reduces hydrogen peroxide (H2 O2 )-induced damage in RPE in a dose-dependent manner. Mechanistic analyses demonstrate that the protective effect encompasses decrease in atRAL-induced intracellular reactive oxygen species and free atRAL levels. Moreover, we show that phloroglucinol reacts with atRAL to form a chromene adduct which prevents bisretinoid A2E synthesis in vitro. Taken together, these data show that the protective effect of phloroglucinol correlates with its ability to trap atRAL and to prevent its further transformation into deleterious bisretinoids. Phloroglucinol might be a good basis to develop efficient therapeutic derivatives in the treatment of retinal macular diseases.

  18. [Study on preferred retinal locus].

    Science.gov (United States)

    Dai, Bing-Fa; Hu, Jian-Min; Xu, Duan-Lian

    2012-03-01

    Preferred retinal locus (PRL) is always found in the age-related macular degeneration and other macular damages in patients with low vision, and it is a very important anatomic position in patients with central vision impairment to achieve the rehabilitation. In recent years, the training of preferred retinal locus (PRL) has become a research hotspot of low vision rehabilitation, it can clearly improve functional vision and quality of life. The authors reviewed relevant literatures, and summarized the definition, position, characteristics, training and clinical implications of the PRL.

  19. Angiographic results of retinal-retinal anastomosis and retinal-choroidal anastomosis after treatments in eyes with retinal angiomatous proliferation

    Directory of Open Access Journals (Sweden)

    Saito M

    2012-08-01

    Full Text Available Masaaki Saito,1 Tomohiro Iida,1,2 Mariko Kano,1 Kanako Itagaki11Department of Ophthalmology, Fukushima Medical University School of Medicine, Fukushima, 2Department of Ophthalmology, Tokyo Women's Medical University School of Medicine, Tokyo, JapanBackground: The purpose of this study was to evaluate the angiographic results of retinal-retinal anastomosis (RRA and retinal-choroidal anastomosis (RCA for eyes with retinal angiomatous proliferation (RAP after treatment with intravitreal bevacizumab injections as monotherapy or intravitreal bevacizumab combined with photodynamic therapy.Methods: In this interventional, consecutive case series, we retrospectively reviewed five naïve eyes from four patients (mean age 80 years treated with three consecutive monthly intravitreal bevacizumab (1.25 mg/0.05 mL injections as initial treatment, and followed up for at least 3 months. In cases with over 3 months of follow-up and having recurrence of RAP or leakage by fluorescein angiography, retreatment was performed with a single intravitreal bevacizumab injection and photodynamic therapy.Results: Indocyanine green angiography showed RRA in three eyes with subretinal neovascularization and RCA in two eyes with choroidal neovascularization at baseline. At 3 months after baseline (month 3, neither the RRA nor RCA was occluded in any eye on indocyanine green angiography. Retreatment with intravitreal bevacizumab plus photodynamic therapy was performed in three eyes at months 3 (persistent leakage on fluorescein angiography, 6, and 7 (recurrence of RAP lesion, which achieved obvious occlusion of the RRA and RCA. Mean best-corrected visual acuity improved from 0.13 to 0.21 at month 3 (P = 0.066. No complications or systemic adverse events were noted.Conclusion: Although intravitreal bevacizumab for RAP was effective in improving visual acuity during short-term follow-up, intravitreal bevacizumab could not achieve complete occlusion of RRA and RCA, which could

  20. Production of a monoclonal antibody by in vitro immunization that recognizes a native chondroitin sulfate epitope in the embryonic chick limb and heart.

    Science.gov (United States)

    Capehart, A A; Wienecke, M M; Kitten, G T; Solursh, M; Krug, E L

    1997-11-01

    We report the production of a monoclonal antibody (d1C4) by in vitro immunization that has immunoreactivity with a native chondroitin sulfate epitope in embryonic chick limb and heart. Murine lymphocytes were stimulated by direct exposure to unfixed, unsolubilized precartilage mesenchymal aggregates in high-density micromass culture derived from Stage 22-23 chick limb buds. Specificity of d1C4 reactivity was demonstrated by sensitivity of immunohistochemical staining to pretreatment with chondroitinase ABC or AC, preferential immunoreactivity with chondroitin-6-sulfate glycosaminoglycan (CS-C GAG) in ELISA, and competition of immunohistochemical staining with CS-C GAG. Immunohistochemical analysis of the expression of the d1C4 epitope revealed a striking localization of immunoreactivity in the extracellular matrix (ECM) of precartilage aggregates of chick limb mesenchyme in high-density micromass culture by 16 hr and the prechondrogenic limb core at Stage 23 in vivo. Immunoreactivity in both cultured limb mesenchyme and the embryonic limb continued through differentiation of prechondrogenic condensations into cartilage tissue. In the developing chick heart, d1C4 staining was found throughout the ECM of atrioventricular cushion tissue by Stage 25, but was localized to mesenchyme adjacent to the myocardium in the outflow tract cushions. There was an abrupt demarcation between d1C4-reactive intracardiac mesenchyme and unreactive extracardiac mesenchyme of the dorsal mesocardium in the Stage 22 embryo. This study demonstrates the efficacy of in vitro immunization of lymphocytes for the production of MAbs to native ECM constituents, such as CS-GAGs. Immunohistochemical data utilizing d1C4 suggest that CS-GAGs bearing this epitope may be important in early morphogenetic events leading to cartilage differentiation in the limb and valvuloseptal morphogenesis in the heart.

  1. Effects of sciatic-conditioned medium on neonatal rat retinal cells in vitro

    Directory of Open Access Journals (Sweden)

    Torres P.M.M.

    1998-01-01

    Full Text Available Schwann cells produce and release trophic factors that induce the regeneration and survival of neurons following lesions in the peripheral nerves. In the present study we examined the in vitro ability of developing rat retinal cells to respond to factors released from fragments of sciatic nerve. Treatment of neonatal rat retinal cells with sciatic-conditioned medium (SCM for 48 h induced an increase of 92.5 ± 8.8% (N = 7 for each group in the amount of total protein. SCM increased cell adhesion, neuronal survival and glial cell proliferation as evaluated by morphological criteria. This effect was completely blocked by 2.5 µM chelerythrine chloride, an inhibitor of protein kinase C (PKC. These data indicate that PKC activation is involved in the effect of SCM on retinal cells and demonstrate that fragments of sciatic nerve release trophic factors having a remarkable effect on neonatal rat retinal cells in culture.

  2. Derivation of Neural Progenitors and Retinal Pigment Epithelium from Common Marmoset and Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Laughing Bear Torrez

    2012-01-01

    Full Text Available Embryonic and induced pluripotent stem cells (IPSCs derived from mammalian species are valuable tools for modeling human disease, including retinal degenerative eye diseases that result in visual loss. Restoration of vision has focused on transplantation of neural progenitor cells (NPCs and retinal pigmented epithelium (RPE to the retina. Here we used transgenic common marmoset (Callithrix jacchus and human pluripotent stem cells carrying the enhanced green fluorescent protein (eGFP reporter as a model system for retinal differentiation. Using suspension and subsequent adherent differentiation cultures, we observed spontaneous in vitro differentiation that included NPCs and cells with pigment granules characteristic of differentiated RPE. Retinal cells derived from human and common marmoset pluripotent stem cells provide potentially unlimited cell sources for testing safety and immune compatibility following autologous or allogeneic transplantation using nonhuman primates in early translational applications.

  3. Cotransport of H+, lactate, and H2O in porcine retinal pigment epithelial cells

    DEFF Research Database (Denmark)

    Hamann, Steffen; Kiilgaard, Jens Folke; la Cour, Morten

    2003-01-01

    The retinal pigment epithelium (RPE) of the eye transports water and lactate ions in the direction from retina to choroid. The water transport is important in maintenance of retinal adhesion and the transport of lactate ions serves to regulate the lactate levels and pH of the subretinal space....... This study investigates by means of a non-invasive technique the mechanism of coupling between transport of H(+), lactate ion, and water in the monocarboxylate transporter (MCT1) located in the apical (retinal) membrane of a mammalian RPE. Primary cultures of porcine RPE cells were grown to confluence...... using the fluorescent dye BCECF. In lactate-free solutions, mannitol addition to the retinal bath caused intracellular acidification and cell shrinkage, given by a single osmotic water permeability of 1.2+/-0.1 x 10(-4)cmsec(-1) (osmoll(-1))(-1). In solutions containing 50 mmoll(-1) lactate, however...

  4. Kidney alkaline phosphatase in mercuric chloride injected chicks resistant and susceptible to leukosis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, V.L.; McIntyre, J.A.; Bearse, G.E.

    1969-01-01

    Two strains of chickens were selected for resistance and susceptibility to avian leukosis. Researchers found that the resistant chicks retained two to four times as much mercury in the liver and kidneys as did the susceptible chicks following injection of mercuric chloride or phenylmercuric acetate. Differences in alkaline phosphatase in the kidneys of the resistant and susceptible chicks, and the effect of the mercuric chloride injection on the alkaline phosphatase activity were reported in this paper. 19 references, 2 tables.

  5. BIGH3 protein and macrophages in retinal endothelial cell apoptosis.

    Science.gov (United States)

    Mondragon, Albert A; Betts-Obregon, Brandi S; Moritz, Robert J; Parvathaneni, Kalpana; Navarro, Mary M; Kim, Hong Seok; Lee, Chi Fung; LeBaron, Richard G; Asmis, Reto; Tsin, Andrew T

    2015-01-01

    Diabetes is a pandemic disease with a higher occurrence in minority populations. The molecular mechanism to initiate diabetes-associated retinal angiogenesis remains largely unknown. We propose an inflammatory pathway of diabetic retinopathy in which macrophages in the diabetic eye provide TGFβ to retinal endothelial cells (REC) in the retinal microvasculature. In response to TGFβ, REC synthesize and secrete a pro-apoptotic BIGH3 (TGFβ-Induced Gene Human Clone 3) protein, which acts in an autocrine loop to induce REC apoptosis. Rhesus monkey retinal endothelial cells (RhREC) were treated with dMCM (cell media of macrophages treated with high glucose and LDL) and assayed for apoptosis (TUNEL), BIGH3 mRNA (qPCR), and protein (Western blots) expressions. Cells were also treated with ΤGFβ1 and 2 for BIGH3 mRNA and protein expression. Inhibition assays were carried out using antibodies for TGFβ1 and for BIGH3 to block apoptosis and mRNA expression. BIGH3 in cultured RhREC cells were identified by immunohistochemistry (IHC). Distribution of BIGH3 and macrophages in the diabetic mouse retina was examined with IHC. RhRECs treated with dMCM or TGFβ showed a significant increase in apoptosis and BIGH3 protein expression. Recombinant BIGH3 added to RhREC culture medium led to a dose-dependent increase in apoptosis. Antibodies (Ab) directed against BIGH3 and TGFβ, as well as TGFβ receptor blocker resulted in a significant reduction in apoptosis induced by either dMCM, TGFβ or BIGH3. IHC showed that cultured RhREC constitutively expressed BIGH3. Macrophage and BIGH3 protein were co-localized to the inner retina of the diabetic mouse eye. Our results support a novel inflammatory pathway for diabetic retinopathy. This pathway is initiated by TGFβ released from macrophages, which promotes synthesis and release of BIGH3 protein by REC and REC apoptosis.

  6. Retinal Inhibition of CCR3 Induces Retinal Cell Death in a Murine Model of Choroidal Neovascularization.

    Directory of Open Access Journals (Sweden)

    Haibo Wang

    Full Text Available Inhibition of chemokine C-C motif receptor 3 (CCR3 signaling has been considered as treatment for neovascular age-related macular degeneration (AMD. However, CCR3 is expressed in neural retina from aged human donor eyes. Therefore, broad CCR3 inhibition may be harmful to the retina. We assessed the effects of CCR3 inhibition on retina and choroidal endothelial cells (CECs that develop into choroidal neovascularization (CNV. In adult murine eyes, CCR3 colocalized with glutamine-synthetase labeled Műller cells. In a murine laser-induced CNV model, CCR3 immunolocalized not only to lectin-stained cells in CNV lesions but also to the retina. Compared to non-lasered controls, CCR3 mRNA was significantly increased in laser-treated retina. An intravitreal injection of a CCR3 inhibitor (CCR3i significantly reduced CNV compared to DMSO or PBS controls. Both CCR3i and a neutralizing antibody to CCR3 increased TUNEL+ retinal cells overlying CNV, compared to controls. There was no difference in cleaved caspase-3 in laser-induced CNV lesions or in overlying retina between CCR3i- or control-treated eyes. Following CCR3i, apoptotic inducible factor (AIF was significantly increased and anti-apoptotic factor BCL2 decreased in the retina; there were no differences in retinal vascular endothelial growth factor (VEGF. In cultured human Műller cells exposed to eotaxin (CCL11 and VEGF, CCR3i significantly increased TUNEL+ cells and AIF but decreased BCL2 and brain derived neurotrophic factor, without affecting caspase-3 activity or VEGF. CCR3i significantly decreased AIF in RPE/choroids and immunostaining of phosphorylated VEGF receptor 2 (p-VEGFR2 in CNV with a trend toward reduced VEGF. In cultured CECs treated with CCL11 and/or VEGF, CCR3i decreased p-VEGFR2 and increased BCL2 without increasing TUNEL+ cells and AIF. These findings suggest that inhibition of retinal CCR3 causes retinal cell death and that targeted inhibition of CCR3 in CECs may be a safer if CCR3

  7. Correlation between plasma steroids and chick visits by nonbreeding adult Nazca boobies.

    Science.gov (United States)

    Tarlow, Elisa M; Wikelski, Martin; Anderson, David J

    2003-03-01

    Nonbreeding adult Nazca boobies (Sula granti) often approach unattended chicks and perform parental and/or aggressive behaviors toward the chicks. Earlier descriptions of these encounters included sexual behaviors as well. We studied hormonal correlates of chick visits by such nonbreeding boobies during the breeding season. We compared the hormonal status of chick-visiting adults with that of nonvisiting adults in the colony. We determined levels of corticosterone (CORT), testosterone (T), androstendione, dihydrotestosterone, and estradiol as potential candidate hormones controlling parental, aggressive, or sexual behavior. Only T and CORT differed between chick-visiting and nonvisiting adults. Chick-visiting adults had higher CORT levels after the interaction than nonvisiting adults randomly caught in the colony. To the contrary. T levels after interactions were lower in chick-visiting compared to random nonvisiting adults. T levels, however, did not vary with level of aggression among chick-visiting adults. We suggest that chick-visiting behavior may be permitted by low T levels and activated by, or resulting in, high CORT levels.

  8. Indirect cannibalism by crèche-aged American White Pelican (Pelecanus erythrorhynchos) chicks

    Science.gov (United States)

    Bartos, Alisa J.; Sovada, Marsha A.; Igl, Lawrence D.; Pietz, Pamela J.

    2013-01-01

    At nesting colonies of American White Pelicans (Pelecanus erythrorhynchos), many chicks die from siblicide, severe weather, and disease; this results in carcasses available for scavenging by conspecifics (i.e., indirect cannibalism). Indirect cannibalism has not been reported previously for this species. We describe five cases of crèche-aged American White Pelican chicks consuming or attempting to consume dead younger chicks at two nesting colonies in the northern plains of North America. Cannibalism in the American White Pelican appears to be rare and likely plays no role in the species’ population ecology or dynamics; however, it might be an important survival strategy of individual chicks when food resources are limited.

  9. Dietary chromium methionine supplementation could alleviate immunosuppressive effects of heat stress in broiler chicks.

    Science.gov (United States)

    Jahanian, R; Rasouli, E

    2015-07-01

    The present study was conducted to investigate the effects of dietary supplementation of chromium methionine (CrMet) on performance, immune responses, and stress status of broiler chicks subjected to heat-stress conditions. A total of 450 day-old Ross 308 broiler chicks were randomly distributed between 5 replicate pens (15 birds each) of 6 experimental treatments according to a 2 × 3 factorial arrangement of treatments including 2 temperature conditions (thermoneutral and heat stress) and 3 supplemental Cr levels (0, 500, and 1,000 μg/kg as CrMet). For induction of heat stress, the house temperature was set at 35 ± 2°C from 15 to 42 d of age. Results showed that the chicks subjected to heat-stress condition had lower (P heat-stressed chicks. Exposure to heat stress suppressed (P heat-stressed chicks, resulting in a significant (P heat-stressed chicks. Dietary inclusion of CrMet improved (P heat-stressed chicks. Exposure to heat stress caused a significant (P heat-stressed chicks modulated (P heat-stress-induced growth retardation in broiler chicks. Moreover, supplemental CrMet modulated suppressive effects of heat stress on cellular and humoral immune responses.

  10. The effects of ingested plastic on growth and survival of albatross chicks

    Science.gov (United States)

    Sievert, Paul R.; Sileo, Louis

    1993-01-01

    We studied the effects of ingested plastic on the growth and survival of chicks of Laysan Albatrosses Diomedea immutabilis and Black-footed albatrosses D. nigripes on Midway Atoll during the nesting seasons of 1986 and 1987. Weights and proventricular contents of the chicks were determined periodically through the nesting cycle. Large (>22 cm1)volumes of plastic were present in the proventriculi of 27% of the Laysan and 16% of the Black-footed albatross chicks examined by endoscopy. Prior to fledging, albatross chicks regurgitated pellets composed of plastic and other indigestible material from their proventriculi. Laysan Albatross chicks with large volumes of proventricular plastic had asymptotic fledging weights significantly lower (122 g) than did chicks with low amounts of plastic. The effect of depresses fledging weights on postfledging survival was not determined. Plastic had no detectable effect on the growth of Black-footed Albatross chicks. All chicks that died were examined by necropsy. Mechanical lesions from ingested plastic were the cause of death of one of 45 Laysan Albatross chicks examined in 1986, but were not the cause of death of 93 individuals examined in 1987. Dehydration was the most common cause of death. In general, ingested plastic was not a significant direct cause of death in nestlings, but there was some evidence that it may have affected survival in 1986, when the volume of plastic ingested was highest.

  11. A study on the growth curve of and maximum profit from layer-type cockerel chicks.

    Science.gov (United States)

    Gang, F Y; Zhen, Y S

    1997-09-01

    1. 2900 commercial layer-type cockerel chicks were reared on the floor from 1-day-old to 9 weeks of age. 2. The growth curve of the cockerel chicks was [formula see text] 3. The feeding costs (US$) of layer-type cockerel chicks were described by the equation Y = a + bx + cx2 = 0.0657 - 0.0091x + 0.0069x2. 4. When the layer-type cockerel chicks' marketing price was US$0.82 per kg. (6.8 Renminbi per kg), the optimum marketing age for maximum profit margin was 5.9 weeks (41 to 42 d).

  12. Intercellular Adhesion-Dependent Cell Survival and ROCK-Regulated Actomyosin-Driven Forces Mediate Self-Formation of a Retinal Organoid

    Directory of Open Access Journals (Sweden)

    Albert Lowe

    2016-05-01

    Full Text Available In this study we dissected retinal organoid morphogenesis in human embryonic stem cell (hESC-derived cultures and established a convenient method for isolating large quantities of retinal organoids for modeling human retinal development and disease. Epithelialized cysts were generated via floating culture of clumps of Matrigel/hESCs. Upon spontaneous attachment and spreading of the cysts, patterned retinal monolayers with tight junctions formed. Dispase-mediated detachment of the monolayers and subsequent floating culture led to self-formation of retinal organoids comprising patterned neuroretina, ciliary margin, and retinal pigment epithelium. Intercellular adhesion-dependent cell survival and ROCK-regulated actomyosin-driven forces are required for the self-organization. Our data supports a hypothesis that newly specified neuroretina progenitors form characteristic structures in equilibrium through minimization of cell surface tension. In long-term culture, the retinal organoids autonomously generated stratified retinal tissues, including photoreceptors with ultrastructure of outer segments. Our system requires minimal manual manipulation, has been validated in two lines of human pluripotent stem cells, and provides insight into optic cup invagination in vivo.

  13. [Progress of research in retinal image registration].

    Science.gov (United States)

    Yu, Lun; Wei, Lifang; Pan, Lin

    2011-10-01

    The retinal image registration has important applications in the processes of auxiliary diagnosis and treatment for a variety of diseases. The retinal image registration can be used to measure the disease process and the therapeutic effect. A variety of retinal image registration techniques have been studied extensively in recent years. However, there are still many problems existing and there are numerous research possibilities. Based on extensive investigation of existing literatures, the present paper analyzes the feature of retinal image and current challenges of retinal image registration, and reviews the transformation models of the retinal image registration technology and the main research algorithms in current retinal image registration, and analyzes the advantages and disadvantages of various types of algorithms. Some research challenges and future developing trends are also discussed.

  14. Chick embryo xenograft model reveals a novel perineural niche for human adipose-derived stromal cells

    Directory of Open Access Journals (Sweden)

    Ingrid R. Cordeiro

    2015-09-01

    Full Text Available Human adipose-derived stromal cells (hADSC are a heterogeneous cell population that contains adult multipotent stem cells. Although it is well established that hADSC have skeletal potential in vivo in adult organisms, in vitro assays suggest further differentiation capacity, such as into glia. Thus, we propose that grafting hADSC into the embryo can provide them with a much more instructive microenvironment, allowing the human cells to adopt diverse fates or niches. Here, hADSC spheroids were grafted into either the presumptive presomitic mesoderm or the first branchial arch (BA1 regions of chick embryos. Cells were identified without previous manipulations via human-specific Alu probes, which allows efficient long-term tracing of heterogeneous primary cultures. When grafted into the trunk, in contrast to previous studies, hADSC were not found in chondrogenic or osteogenic territories up to E8. Surprisingly, 82.5% of the hADSC were associated with HNK1+ tissues, such as peripheral nerves. Human skin fibroblasts showed a smaller tropism for nerves. In line with other studies, hADSC also adopted perivascular locations. When grafted into the presumptive BA1, 74.6% of the cells were in the outflow tract, the final goal of cardiac neural crest cells, and were also associated with peripheral nerves. This is the first study showing that hADSC could adopt a perineural niche in vivo and were able to recognize cues for neural crest cell migration of the host. Therefore, we propose that xenografts of human cells into chick embryos can reveal novel behaviors of heterogeneous cell populations, such as response to migration cues.

  15. Regulation of chick early B-cell factor-1 gene expression in feather development.

    Science.gov (United States)

    El-Magd, Mohammed Abu; Sayed-Ahmed, Ahmed; Awad, Ashraf; Shukry, Mustafa

    2014-05-01

    The chick Ebf1 (early B-cell factor-1) gene is a member of a novel family of helix loop helix transcription factors. The expression profile, regulation and significance of this gene have been extensively studied in lymphatic, nervous, adipose and muscular tissues. However, cEbf1 expression, regulation and function in the feather of chick embryo have not yet been investigated. cEbf1 expression was first detected throughout the mesenchymal core of some few feather placodes (D7-D7.5). After feathers became mature and grew distally (D9 and D10), the mesenchymal expression of cEbf1 became confined to the caudal margin of the proximal half of all formed feather buds. Because this dynamic pattern of expression resembles that of Sonic Hedgehog (Shh) protein and bone morphogenetic protein (Bmp4) plus the crucial role of these two major signals in feather development, we hypothesized that cEbf1 expression in the feather may be regulated by Shh and Bmp4. In a feather explant culture system, Shh signals are necessary to initiate and maintain cEbf1 expression in the posterior half of the feather bud, while Bmp4 is crucial for the initial cEbf1 expression in the anterior half of the feather bud. Inhibition of Shh, not only down-regulates cEbf1, but also changes the morphology of feather buds, which become irregular and fused. This is the first study to demonstrate that cEbf1 expression in the feather bud is under the control of Shh and Bmp4 signals and that expression may play a role in the normal development of feathers.

  16. Retinal imaging and image analysis

    NARCIS (Netherlands)

    Abramoff, M.D.; Garvin, Mona K.; Sonka, Milan

    2010-01-01

    Many important eye diseases as well as systemic diseases manifest themselves in the retina. While a number of other anatomical structures contribute to the process of vision, this review focuses on retinal imaging and image analysis. Following a brief overview of the most prevalent causes of blindne

  17. [Surgical managment of retinal detachment].

    Science.gov (United States)

    Haritoglou, C; Wolf, A

    2015-05-01

    The detachment of the neurosensory retina from the underlying retinal pigment epithelium can be related to breaks of the retina allowing vitreous fluid to gain access to the subretinal space, to exudative changes of the choroid such as tumours or inflammatory diseases or to excessive tractional forces exerted by interactions of the collagenous vitreous and the retina. Tractional retinal detachment is usually treated by vitrectomy and exudative detachment can be addressed by treatment of the underlying condition in many cases. In rhegmatogenous retinal detachment two different surgical procedures, vitrectomy and scleral buckling, can be applied for functional and anatomic rehabilitation of our patients. The choice of the surgical procedure is not really standardised and often depends on the experience of the surgeon and other more ocular factors including lens status, the number of retinal breaks, the extent of the detachment and the amount of preexisting PVR. Using both techniques, anatomic success rates of over 90 % can be achieved. Especially in young phakic patients scleral buckling offers the true advantage to prevent the progression of cataract formation requiring cataract extraction and intraocular lens implantation. Therefore, scleral buckling should be considered in selected cases as an alternative surgical option in spite of the very important technical refinements in modern vitrectomy techniques. Georg Thieme Verlag KG Stuttgart · New York.

  18. Effects of breeder age and egg weight on morphological changes in the small intestine of chicks during the hatch window.

    Science.gov (United States)

    Yalçin, S; Izzetoğlu, G T; Aktaş, A

    2013-01-01

    1. The objective of the study was to investigate the effects of breeder age and egg weight on hatching performance and morphological changes in segments of the small intestine of broiler chicks during a 21 h hatch window. 2. Eggs from Ross broiler breeder flocks aged 29 (young) and 48 weeks (old) were classified as light (LE) or heavy (HE) and incubated at the same conditions. At 475 h of incubation, eggs were checked every 3 h to determine time of external pipping and hatching. The first 42 chicks to emerge from each group were weighed and chick length was measured and 14 chicks from each group were sampled to collect residual yolk and intestine segments. The rest of chicks were placed back in the incubator and chick weight and length were measured individually at 9, 15 and 21 h after chicks hatched. At the end of 21 h, 14 chicks from each group were sampled again and the same procedure was followed. 3. The HE chicks pipped and hatched later than LE, regardless of breeder age. From hatch to the end of the hatch window, chick weight, but not yolk-free chick weight, gradually reduced. Relative residual yolk weight of chicks from both egg weights was similar at hatch, however, yolk sac utilisation was higher for LE chicks during the 21 h post-hatch period. At hatch, jejunum and ileum villus development was very similar for HE and LE chicks but greater development was observed for villus area with an increase in the jejunum villus length, width and goblet cell numbers in HE chicks. 4. The longest jejunum villus and the widest duodenum and jejunum villus were obtained for HE chicks from old breeders indicating that HE chicks from old breeders would have a greater surface area for nutrient absorption.

  19. Retinal detachment in a patient with extensive myelinated retinal nerve fibers.

    Science.gov (United States)

    Chen, Muh-Shy; Ho, Tzyy-Chang; Chang, Ching-Chung; Hou, Ping-Kang

    2007-01-01

    We report extensive myelinated retinal nerve fibers in a 42-year-old patient with retinal detachment. Fundus examination revealed a horseshoe-shaped tear near the temporal edge. Pars plana vitrectomy was performed and firm vitreo-retinal adhesion was noticed in the area of extensive myelinated retinal nerve fibers. Following vitrectomy with silicone oil tamponade, the retina was reattached successfully. In conclusion, retinal detachment may develop in patients with extensive myelinated retinal nerve fibers. Vitrectomy may be performed to treat this condition.

  20. Changes in free amino acid and monoamine concentrations in the chick brain associated with feeding behavior.

    Science.gov (United States)

    Tran, Phuong V; Chowdhury, Vishwajit S; Nagasawa, Mao; Furuse, Mitsuhiro

    2015-01-01

    Domesticated chicks are precocial and therefore have relatively well-developed feeding behavior. The role of hypothalamic neuropeptides in food-intake regulation in chicks has been reported for decades. However, we hypothesized that nutrients and their metabolites in the brain may be involved in food intake in chicks because these animals exhibit a very frequent feeding pattern. Therefore, the purpose of this study was to examine the feeding behavior of chicks as well as the associated changes in free amino acid and monoamine concentrations in the chick brain. The feeding behavior of chicks was recorded continuously for 6 h. The next day, brain and blood samples were collected when the chicks either attempted to have food (hungry group) or turned food down (satiated group), in order to analyze the concentrations of the free amino acids and monoamines. We confirmed that the feeding behavior of neonatal chicks was characterized by short resting periods between very brief times spent on food intake. Several free amino acids in the mesencephalon were significantly lower in the satiated group than in the hungry group, while l-histidine and l-glutamine were significantly higher. Notably, there was no change in the free amino acid concentrations in other brain regions or plasma. As for monoamines, serotonin and norepinephrine were significantly lower in the mesencephalon of the hungry group compared with the satiated group, but 5 hydroxyindolacetic acid (5-HIAA) was higher. In addition, serotonin and norepinephrine levels were significantly higher in the brain stem of the hungry chicks compared with the satiated group, but levels of 5-HIAA and homovanillic acid were lower. Levels of both dopamine and its metabolite, 3,4-dihydroxyphenylacetic acid, were significantly higher in the diencephalon and telencephalon of the chicks in the hungry group. In conclusion, the changes in the free amino acids and monoamines in the brain may have some role in the feeding behavior of

  1. 重组人促红细胞生成素对高糖培养大鼠视网膜 Müller细胞的影响%Effects of recombinant human erythropoietin on high glucose cultured retinal M üller cells

    Institute of Scientific and Technical Information of China (English)

    曲虹; 厉泉

    2015-01-01

    Objective Present study was to investigate the effect of recombinant human erythropoietin on retinal Müller cells cultured in high glucose.Methods Serial subcultivated neonatal rats’ retinal Müller cells were divided into normal control group, G25(25mmol/Lglucose) group, G50(50mmol/Lglucose), EG25(4 ×104 IU/L recombinant human erythropoietin+25mmol/L glucose) group and EG50 (4 ×104 IU/L recombinant human erythropoietin +50mmol/Lglucose) group.MTT assay was applied to detect cell viability in five groups.The expression of glutamine synthetase was measured by immunofluorescence and enzyme linked immunosorbent assay.Results Cell viability of G25 group, G50 group, EG25 group and EG50 group was lower than that of normal group.Cell viability of EG25 group was higher than that of G25 group, and EG50 group was higher than that of G50 group.Cells expressed glutamine synthetase in five groups.The expression of glutamine synthetase in normal group was higher than that in other four groups where cells were cultured in high glucose. The expression of glutamine synthetase in EG25 group and EG50 group were higher than that in G25 group and G50 group re-spectively.Conclusion Recombinant human erythropoietin could increase the cell viability and the expression of gluta-mine synthetase in retinal Müller cells cultured in high glucose.%目的:探讨重组人促红细胞生成素对高浓度葡萄糖培养大鼠视网膜Müller细胞功能的影响。方法体外传代培养大鼠视网膜Müller细胞,分组为N组(正常对照),G25组(25 mmol/L葡萄糖),G50组(50 mmol/L葡萄糖),EG25组(4×104IU/L rhEPO+25 mmol/L葡萄糖),EG50组(4×104IU/L rhEPO+50 mmol/L葡萄糖),MTT检测各组细胞活性。细胞免疫染色、ELISA检测各组细胞GS蛋白表达的情况。结果 MTT检测示N组细胞活性高于G25组、G50组、EG25组和EG50组,EG25组高于G25组,EG50组高于G50组。细胞免疫荧光染色检测各组

  2. ASSOCIATION BETWEEN RETINAL HEMORRHAGIC PATTERNS AND PERFUSION STATUS IN EYES WITH ACUTE CENTRAL RETINAL VEIN OCCLUSION.

    Science.gov (United States)

    Muraoka, Yuki; Uji, Akihito; Tsujikawa, Akitaka; Murakami, Tomoaki; Ooto, Sotaro; Suzuma, Kiyoshi; Takahashi, Ayako; Iida, Yuto; Miwa, Yuko; Hata, Masayuki; Yoshimura, Nagahisa

    2017-03-01

    To evaluate peripheral retinal hemorrhagic patterns in eyes with acute central retinal vein occlusion, and to explore their clinical relevance in differentiating for the retinal perfusion status, through a prospective, and cross-sectional study. Fifty eyes with acute central retinal vein occlusion were included. Retinal hemorrhagic patterns at the equator and retinal perfusion status were evaluated by ultra-wide field fundus photography and fluorescein angiography. Retinal perfusion was categorized as nonischemic in 29 eyes, ischemic in 18 eyes, and undeterminable in 3 eyes. None of the examined eyes had flame-shaped retinal hemorrhages in the periphery. All hemorrhages were rounded-dot or blot and were variable in size. Particle analysis was performed to quantify hemorrhage size, and showed higher values in eyes having larger blot hemorrhages, and lower values in eyes having dot or smaller blot hemorrhages. Mean size of maximum peripheral dot or blot hemorrhage was larger in eyes classified as ischemic (10,763.0 ± 5,946.3 pixels) than as nonischemic (2,839.9 ± 1,153.6 pixels, P retinal perfusion status, which was 0.963 (P retinal hemorrhagic patterns at the equator in eyes with acute central retinal vein occlusion using particle analysis. The resulting hemorrhage size measurement was considered to be often useful in determining retinal perfusion status. Because they can be noninvasively evaluated with readily available equipment, peripheral hemorrhagic patterns might be good clinical markers of retinal perfusion.

  3. Induction of an antimicrobial biotin-binding egg white protein (avidin) in chick tissues in septic Escherichia coli infection.

    Science.gov (United States)

    Elo, H A; Räisänen, S; Tuohimaa, P J

    1980-03-15

    The induction of avidin in chick tissues was found in septic Escherichia coli infection. Avidin concentrations in the plasma roughly corresponded to those in the other tissues studied which suggests that avidin in chicks is a secretory protein.

  4. Cytomegalovirus retinitis associated with acquired immunodeficiency syndrome

    Institute of Scientific and Technical Information of China (English)

    GENG Shuang; YE Jun-jie; ZHAO Jia-liang; LI Tai-sheng; HAN Yang

    2011-01-01

    Background Cytomegalovirus (CMV) retinitis is the most severe intraocular complication that results in total retinal destruction and loss of visual acuity in patients with acquired immunodeficiency syndrome (AIDS). This study aimed to investigate the fundus characteristics, systemic manifestations and therapeutic outcomes of CMV retinitis associated with AIDS.Methods It was a retrospective case series. CMV retinitis was present in 39 eyes (25 patients). Best corrected visual acuities, anterior segment, fundus features, fundus fluorescence angiography (FFA) and CD4+ T-lymphocyte counts of the patients with CMV retinitis associated with AIDS were analyzed. Intravitreal injections of ganciclovir (400 μg) were performed in 4 eyes (2 patients).Results Retinal vasculitis, dense, full-thickness, yellow-white lesions along vascular distribution with irregular granules at the border, and hemorrhage on the retinal surface were present in 28 eyes. The vitreous was clear or mildly opaque.Late stage of the retinopathy was demonstrated in 8 eyes characterized as atrophic retina, sclerotic and attenuated vessels, retinal pigment epithelium (RPE) atrophy, and optic nerve atrophy. Retinal detachment was found in 3 eyes. The average CD4+ T-lymphocyte count in peripheral blood of the patients with CMV retinitis was (30.6±25.3) ×106/L (range,(0-85) × 106/L). After intravitreal injections of ganciclovir, visual acuity was improved and fundus lesions regressed.Conclusions CMV retinitis is the most severe and the most common intraocular complication in patients with AIDS. For the patients with yellow-white retinal lesions, hemorrhage and retinal vasculitis without clear cause, human immunodeficiency virus (HIV) serology should be performed. Routine eye examination is also indicated in HIV positive patients.

  5. Experimental infection of one-day-old chicks with Salmonella Serotypes Previously isolated from poultry facilities, wild birds, and swine

    Directory of Open Access Journals (Sweden)

    E de Sousa

    2013-12-01

    Full Text Available In order to maintain the high production and export rates achieved by the Brazilian poultry industry, it is necessary to prevent and control certain disease agents, such as Salmonella spp. Using bacterial cultures, the aim of the present study was to investigate the prevalence of Salmonella spp. in specimens collected from broiler facilities. Local wild birds were also sampled, as well as the feces of swine housed on the poultry farm. After sample collection, the isolated serotypes were subsequently inoculated into broiler chicks to determine their effects. Positive samples were collected from the following locations in the poultry facilities: poultry litter (S. serotype 4,5,12:R:-; S. Heidelberg; S. Infantis, broiler feces (S. Heidelberg; S. serotype 6,7:R:-; S. serotype 4,5,12:R:-; S. Tennessee, water (S. Glostrup; S. serotype 6,8:d:-;, and lesser mealworms (Alphitobius diaperinus found in the litter (S. Tennessee. Among the 36 wild birds captured, S. Heidelberg was isolated from one bird's organs and intestinal contents (Colaptes campestris, and S. Enteritidis was isolated from another bird's intestinal contents (Zenaida auriculata. Salmonella Panama and Salmonella Typhimurium were isolated from swine feces. One-day-old chicks (150 were divided into 10 groups of 15 animals each. Each group was orally inoculated with a previously isolated serotype of Salmonella. Soft stools were observed on the cage floor and around the birds' cloaca between 3 and 12 days post-infection (dpi. The different serotypes of Salmonella used to inoculate the chicks were re-isolated from the spleen, liver, and cecal content samples of the infected birds on 15 and 21 dpi.

  6. [Vitreo-retinal surgery for complicated retinal detachment].

    Science.gov (United States)

    Wang, J Z

    1993-07-01

    93 eyes (93 patients) of complicated retinal detachment were treated with vitreo-retinal surgery. Among the series, 75 eyes were rhegmatogenous with PVR C3-D3 in 66 eyes (88.0%), while the remaining 18 eyes were traction induced. None of the cases had giant tears or complicating diabetes. On discharge from the hospital, the operation was effective in 62 cases (66.7%), in whom the retina was totally reattached or only a small amount of subretinal fluid remained. In a group of 40 eyes where the inert gas SF6 was used, the operation was effective in 30 cases (75.0%). 41 cases were followed up postoperatively for over 3 months, averaging 13.7 months, to find the operative results stable in 33 eyes (80.5%), with the visual acuity improved in 22 cases (66.7%), unchanged in 9 cases (27.3%), and decreased in 2 cases (6.0%). The operative procedures, the peeling of pre-retinal membrane, the effect of PVR severity on the operative results, and the promotion of operative efficacy by application of wide encircling buckle and inert gas tamponade were discussed.

  7. EFFECTS OF PRIMARY IMPRINTING ON THE SUBSEQUENT DEVELOPMENT OF SECONDARY FILIAL ATTACHMENTS IN THE CHICK

    NARCIS (Netherlands)

    DEVOS, GJ; VANKAMPEN, HS

    This study reinvestigates the effects of primary imprinting of chicks with either a naturalistic stimulus or an artificial object on subsequent imprinting with artificial objects. Initial experience with a live chick (group C) or a yellow cylinder (group Y) had differential effects on the

  8. Short communication: hippocampal neuronal activity and imprinting in the behaving domestic chick.

    Science.gov (United States)

    Nicol, A U; Brown, M W; Horn, G

    1998-08-01

    The hippocampus of the chick projects to the intermediate and medial part of the hyperstriatum ventrale (IMHV) which stores information acquired through the learning process of imprinting. We have investigated whether the response properties of hippocampal neurons are similar to those of IMHV neurons. Chicks were imprinted by exposure, one group (n = 7) to a rotating red box (RB), the other (n = 5) to a rotating blue cylinder (BC). Four chicks were untrained. The following day, when the chicks were approximately 48 h old, neuronal activity was recorded in the left hippocampus. The proportion of neurons responding to the RB and that to the BC in untrained chicks were compared with the proportions in trained birds. (i) In RB-trained chicks both the proportion responding to the RB and that to the BC were significantly increased. (ii) In BC-trained chicks no significant effect on these proportions was found. Of the responsive neurons some were colour (red or blue) sensitive and others were shape (box or cylinder) sensitive; the proportions so responsive were not influenced by training condition. Certain neurons responded significantly differently when a stimulus was 0.5 m or 2 m from the chick (35%; d-sensitive); very few neurons were equivalently responsive to a stimulus at both distances (3%; d-invariant). These proportions were not significantly affected by training condition. Hippocampal responses are compared with those in the left IMHV. It is concluded that IMHV responses do not passively reflect those of hippocampal neurons.

  9. Classification of neuromuscular blocking agents in a new neuromuscular preparation of the chick in vitro

    NARCIS (Netherlands)

    Riezen, H. van

    1968-01-01

    A neuromuscular preparation of the chick is described: 1. 1. The sciatic nerve-tibilis anterior muscle preparation of the 2–10 days old chick fulfils all criteria of an assay preparation and differentiates between curare-like and decamethonium-like agents. 2. 2. The preparation responds to

  10. EFFECTS OF PRIMARY IMPRINTING ON THE SUBSEQUENT DEVELOPMENT OF SECONDARY FILIAL ATTACHMENTS IN THE CHICK

    NARCIS (Netherlands)

    DEVOS, GJ; VANKAMPEN, HS

    1993-01-01

    This study reinvestigates the effects of primary imprinting of chicks with either a naturalistic stimulus or an artificial object on subsequent imprinting with artificial objects. Initial experience with a live chick (group C) or a yellow cylinder (group Y) had differential effects on the developmen

  11. Foraging behavior and physiological changes in precocial quail chicks in response to low temperatures

    NARCIS (Netherlands)

    Krijgsveld, KL; Visser, GH; Daan, S

    2003-01-01

    We examined whether low ambient temperatures influence foraging behavior of precocial Japanese quail chicks and alter the balance between investment in growth and thermogenic function. To test this, one group of chicks was exposed to 7 degreesC and one group to 24 degreesC during foraging throughout

  12. Agmatine protects retinal ganglion cells from hypoxia-induced apoptosis in transformed rat retinal ganglion cell line

    Directory of Open Access Journals (Sweden)

    Kim Chan

    2007-10-01

    Full Text Available Abstract Background Agmatine is an endogenous polyamine formed by the decarboxylation of L-arginine. We investigated the protective effects of agmatine against hypoxia-induced apoptosis of immortalized rat retinal ganglion cells (RGC-5. RGC-5 cells were cultured in a closed hypoxic chamber (5% O2 with or without agmatine. Cell viability was determined by lactate dehydrogenase (LDH assay and apoptosis was examined by annexin V and caspase-3 assays. Expression and phosphorylation of mitogen-activated protein kinases (MAPKs; JNK, ERK p44/42, and p38 and nuclear factor-kappa B (NF-κB were investigated by Western immunoblot analysis. The effects of agmatine were compared to those of brain-derived neurotrophic factor (BDNF, a well-known protective neurotrophin for retinal ganglion cells. Results After 48 hours of hypoxic culture, the LDH assay showed 52.3% cell loss, which was reduced to 25.6% and 30.1% when agmatine and BDNF were administered, respectively. This observed cell loss was due to apoptotic cell death, as established by annexin V and caspase-3 assays. Although total expression of MAPKs and NF-κB was not influenced by hypoxic injury, phosphorylation of these two proteins was increased. Agmatine reduced phosphorylation of JNK and NF-κB, while BDNF suppressed phosphorylation of ERK and p38. Conclusion Our results show that agmatine has neuroprotective effects against hypoxia-induced retinal ganglion cell damage in RGC-5 cells and that its effects may act through the JNK and NF-κB signaling pathways. Our data suggest that agmatine may lead to a novel therapeutic strategy to reduce retinal ganglion cell injury related to hypoxia.

  13. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants

    Science.gov (United States)

    Olivares-González, Lorena; Martínez-Fernández de la Cámara, Cristina; Hervás, David; Marín, María Pilar; Lahoz, Agustin; Millán, José María

    2016-01-01

    Retinal hypoxia and oxidative stress are involved in several retinal degenerations including diabetic retinopathy, glaucoma, central retinal artery occlusion, or retinopathy of prematurity. The second messenger cyclic guanosine monophosphate (cGMP) has been reported to be protective for neuronal cells under several pathological conditions including ischemia/hypoxia. The purpose of this study was to evaluate whether the accumulation of cGMP through the pharmacological inhibition of phosphodiesterase (PDE) with Zaprinast prevented retinal degeneration induced by mild hypoxia in cultures of porcine retina. Exposure to mild hypoxia (5% O2) for 24h reduced cGMP content and induced retinal degeneration by caspase dependent and independent (PARP activation) mechanisms. Hypoxia also produced a redox imbalance reducing antioxidant response (superoxide dismutase and catalase activities) and increasing superoxide free radical release. Zaprinast reduced mild hypoxia-induced cell death through inhibition of caspase-3 or PARP activation depending on the cell layer. PDE inhibition also ameliorated the effects of mild hypoxia on antioxidant response and the release of superoxide radical in the photoreceptor layer. The use of a PKG inhibitor, KT5823, suggested that cGMP-PKG pathway is involved in cell survival and antioxidant response. The inhibition of PDE, therefore, could be useful for reducing retinal degeneration under hypoxic/ischemic conditions. PMID:27861632

  14. Imprinted Numbers: Newborn Chicks' Sensitivity to Number vs. Continuous Extent of Objects They Have Been Reared with

    Science.gov (United States)

    Rugani, Rosa; Regolin, Lucia; Vallortigara, Giorgio

    2010-01-01

    Newborn chicks were tested for their sensitivity to number vs. continuous physical extent of artificial objects they had been reared with soon after hatching. Because of the imprinting process, such objects were treated by chicks as social companions. We found that when the objects were similar, chicks faced with choices between 1 vs. 2 or 2 vs. 3…

  15. Protection of non-immunized broiler chicks housed with immunized cohorts against infection with Eimeria maxima and E. acervulina

    Science.gov (United States)

    The use of live oocyst vaccines is becoming increasingly important in the control of avian coccidosis in broiler chicks. Knowledge of the mechanisms of how chicks uptake oocysts and become immune is important for optimizing delivery of live vaccines. The current study tests the hypothesis that chick...

  16. Automatic Vessel Segmentation on Retinal Images

    Institute of Scientific and Technical Information of China (English)

    Chun-Yuan Yu; Chia-Jen Chang; Yen-Ju Yao; Shyr-Shen Yu

    2014-01-01

    Several features of retinal vessels can be used to monitor the progression of diseases. Changes in vascular structures, for example, vessel caliber, branching angle, and tortuosity, are portents of many diseases such as diabetic retinopathy and arterial hyper-tension. This paper proposes an automatic retinal vessel segmentation method based on morphological closing and multi-scale line detection. First, an illumination correction is performed on the green band retinal image. Next, the morphological closing and subtraction processing are applied to obtain the crude retinal vessel image. Then, the multi-scale line detection is used to fine the vessel image. Finally, the binary vasculature is extracted by the Otsu algorithm. In this paper, for improving the drawbacks of multi-scale line detection, only the line detectors at 4 scales are used. The experimental results show that the accuracy is 0.939 for DRIVE (digital retinal images for vessel extraction) retinal database, which is much better than other methods.

  17. Studies on the Relationship between the Embryonic Heart Development and the Amnion Folding in Chick

    Directory of Open Access Journals (Sweden)

    Yongqing Li

    2006-01-01

    Full Text Available As a model animal for developmental biology, chick embryo is easy to control and observe during embryo development period and therefore it is widely used in the study of cardiac development. The application of proteomics has opened the door for large-scale studies to dissect both protein expression, regulation and function during chick heart developing stages. The proteomics study requires to quickly separate a large number of chick heart samples with the same developing stage. However, the traditional morphological standards based on Hamburger-Hamilton and Witschi stages are difficult to fulfill this requirement. Herein, we suppose a new standard for distinguishing chick heart morphology in different developing stages based on the relationship between the embryonic heart development and the amnion folding in chick. Based on this standard, we can accelerate the speed of embryonic heart sample separation and guarantee the quantity and quality of the sample more reliably.

  18. Retinal Cell Degeneration in Animal Models

    OpenAIRE

    Masayuki Niwa; Hitomi Aoki; Akihiro Hirata; Hiroyuki Tomita; Green, Paul G.; Akira Hara

    2016-01-01

    The aim of this review is to provide an overview of various retinal cell degeneration models in animal induced by chemicals (N-methyl-d-aspartate- and CoCl2-induced), autoimmune (experimental autoimmune encephalomyelitis), mechanical stress (optic nerve crush-induced, light-induced) and ischemia (transient retinal ischemia-induced). The target regions, pathology and proposed mechanism of each model are described in a comparative fashion. Animal models of retinal cell degeneration provide insi...

  19. Intrinsically photosensitive retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    Gary; E.PICKARD; Patricia; J.SOLLARS

    2010-01-01

    A new mammalian photoreceptor was recently discovered to reside in the ganglion cell layer of the inner retina.These intrinsically photosensitive retinal ganglion cells(ipRGCs) express a photopigment,melanopsin,that confers upon them the ability to respond to light in the absence of all rod and cone photoreceptor input.Although relatively few in number,ipRGCs extend their dendrites across large expanses of the retina making them ideally suited to function as irradiance detectors to assess changes in ambient light levels.Phototransduction in ipRGCs appears to be mediated by transient receptor potential channels more closely resembling the phototransduction cascade of invertebrate rather than vertebrate photoreceptors.ipRGCs convey irradiance information centrally via the optic nerve to influence several functions.ipRGCs are the primary retinal input to the hypothalamic suprachiasmatic nucleus(SCN),a circadian oscillator and biological clock,and this input entrains the SCN to the day/night cycle.ipRGCs contribute irradiance signals that regulate pupil size and they also provide signals that interface with the autonomic nervous system to regulate rhythmic gene activity in major organs of the body.ipRGCs also provide excitatory drive to dopaminergic amacrine cells in the retina,providing a novel basis for the restructuring of retinal circuits by light.Here we review the ground-breaking discoveries,current progress and directions for future investigation.

  20. CD133+ adult human retinal cells remain undifferentiated in Leukaemia Inhibitory Factor (LIF

    Directory of Open Access Journals (Sweden)

    Mayer Eric J

    2009-02-01

    Full Text Available Abstract Background CD133 is a cell surface marker of haematopoietic stem and progenitor cells. Leukaemia inhibitory factor (LIF, sustains proliferation and not differentiation of embryonic stem cells. We used CD133 to purify adult human retinal cells and aimed to determine what effect LIF had on these cultures and whether they still had the ability to generate neurospheres. Methods Retinal cell suspensions were derived from adult human post-mortem tissue with ethical approval. With magnetic automated cell sorting (MACS CD133+ retinal cells were enriched from post mortem adult human retina. CD133+ retinal cell phenotype was analysed by flow cytometry and cultured cells were observed for proliferative capacity, neuropshere generation and differentiation with or without LIF supplementation. Results We demonstrated purification (to 95% of CD133+ cells from adult human postmortem retina. Proliferating cells were identified through BrdU incorporation and expression of the proliferation markers Ki67 and Cyclin D1. CD133+ retinal cells differentiated whilst forming neurospheres containing appropriate lineage markers including glia, neurons and photoreceptors. LIF maintained CD133+ retinal cells in a proliferative and relatively undifferentiated state (Ki67, Cyclin D1 expression without significant neurosphere generation. Differentiation whilst forming neurospheres was re-established on LIF withdrawal. Conclusion These data support the evidence that CD133 expression characterises a population of cells within the resident adult human retina which have progenitor cell properties and that their turnover and differentiation is influenced by LIF. This may explain differences in retinal responses observed following disease or injury.

  1. Mitochondrial dysfunction underlying outer retinal diseases

    DEFF Research Database (Denmark)

    Lefevere, Evy; Toft-Kehler, Anne Katrine; Vohra, Rupali

    2017-01-01

    Dysfunction of photoreceptors, retinal pigment epithelium (RPE) or both contribute to the initiation and progression of several outer retinal disorders. Disrupted Müller glia function might additionally subsidize to these diseases. Mitochondrial malfunctioning is importantly associated with outer...... retina pathologies, which can be classified as primary and secondary mitochondrial disorders. This review highlights the importance of oxidative stress and mitochondrial DNA damage, underlying outer retinal disorders. Indeed, the metabolically active photoreceptors/RPE are highly prone to these hallmarks...... of mitochondrial dysfunction, indicating that mitochondria represent a weak link in the antioxidant defenses of outer retinal cells....

  2. RETINAL VASCULITIS ASSOCIATED WITH NEUROMYELITIS OPTICA.

    Science.gov (United States)

    Mikhail, Mikel; Khan, Ayesha

    2017-01-01

    To report a case of retinal vasculitis in a patient with neuromyelitis optica. Clinical case report, imaging was obtained with photographs, fluorescein angiography, spectral domain optical coherence tomography, and magnetic resonance imaging. The aforementioned patient presented with urinary incontinence and spastic paraparesis. She was found to have a transverse myelitis on magnetic resonance imaging and positive anti-aquaporin-4 (AQP4-Ab) testing. She had no associated visual symptoms. Examination revealed a retinal vasculitis. There have been no previous reports of retinal vasculitis associated with neuromyelitis optica or neuromyelitis optica spectrum disorder. Retinal vasculitis can be associated with neuromyelitis optica.

  3. Retinal Macroglial Responses in Health and Disease

    Directory of Open Access Journals (Sweden)

    Rosa de Hoz

    2016-01-01

    Full Text Available Due to their permanent and close proximity to neurons, glial cells perform essential tasks for the normal physiology of the retina. Astrocytes and Müller cells (retinal macroglia provide physical support to neurons and supplement them with several metabolites and growth factors. Macroglia are involved in maintaining the homeostasis of extracellular ions and neurotransmitters, are essential for information processing in neural circuits, participate in retinal glucose metabolism and in removing metabolic waste products, regulate local blood flow, induce the blood-retinal barrier (BRB, play fundamental roles in local immune response, and protect neurons from oxidative damage. In response to polyetiological insults, glia cells react with a process called reactive gliosis, seeking to maintain retinal homeostasis. When malfunctioning, macroglial cells can become primary pathogenic elements. A reactive gliosis has been described in different retinal pathologies, including age-related macular degeneration (AMD, diabetes, glaucoma, retinal detachment, or retinitis pigmentosa. A better understanding of the dual, neuroprotective, or cytotoxic effect of macroglial involvement in retinal pathologies would help in treating the physiopathology of these diseases. The extensive participation of the macroglia in retinal diseases points to these cells as innovative targets for new drug therapies.

  4. Retinal occlusive vasculer disorder and rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Huseyin Ortak

    2013-03-01

    Full Text Available Rheumatoid arthritis is a systemic inflammatory disease that affected older women with many ocular manifestations. Also, these systemic diseases can cause retinal vein occlusion and arterial occlusion that lead to serious and permanent visual loss. Rheumatoid arthritis's the most common manifestation is that retinal vasculitis and retinal vascular complications are associated with this complication. In this review, retinal vascular occlusive diseases are presented to associated with rheumatoid arthritis in literature. Rheumatoid arthritis and its complications have been outlined and was made to create a new perspective. [J Contemp Med 2013; 3(1.000: 71-73

  5. Shh regulates chick Ebf1 gene expression in somite development.

    Science.gov (United States)

    El-Magd, Mohammed Abu; Allen, Steve; McGonnell, Imelda; Mansour, Ali A; Otto, Anthony; Patel, Ketan

    2015-01-01

    The chick early B-cell factor 1 (cEbf1) is a member of EBF family of helix loop helix transcription factors. Recently, we have proved that cEbf1 expression in feather is regulated by Shh. It is therefore possible that the somitic expression of cEbf1 is controlled by Shh signals from the notochord. To assess this hypothesis, the expression profile of cEbf1 was first detailed in somites of chick embryos (from HH8 to HH28). cEbf1 expression was mainly localised in the medial sclerotome and later around the vertebral cartilage anlagen of body and pedicles. Tissue manipulations (notochord ablation) and Shh gain and loss of function experiments were then performed to analyse whether the notochord and/or Shh regulate cEbf1 expression. Results from these experiments confirmed our hypothesis that the medial somitic expression of cEbf1 is regulated by Shh from the notochord. In conclusion, cEbf1 gene is considered as a medial sclerotome marker, downstream to and regulated by the notochord derived Shh, which may be functionally involved in somitogenesis.

  6. Aquaporin-1 expression in the chick embryo chorioallantoic membrane.

    Science.gov (United States)

    Ribatti, Domenico; Frigeri, Antonio; Nico, Beatrice; Nicchia, Grazia Paola; De Giorgis, Michela; Roncali, Luisa; Svelto, Maria

    2002-10-01

    The chick embryo chorioallantoic membrane (CAM) is commonly used in vivo to study both angiogenesis and anti-angiogenesis. Rapid membrane water transport is mediated by a family of molecular water channels, called aquaporins (AQPs), which have been identified in the epithelial and endothelial cells of higher vertebrates. AQP1, expressed in adsorptive and secretory epithelia, is also expressed in endothelial cells of capillaries and arteries. Its mRNA has been found in vascular smooth muscle cells (VSMCs) of arteries and capillaries, as well as in a subset of VSMCs of human atherosclerotic plaques. This study investigated the developmental expression of AQP1 in the chick CAM by Western blot and immunohistochemistry. Western blot results show that a major nonglycosylated band was observed with electrophoretic mobility of approximately 28 kDa in the three developmental stages examined. Immunohistochemistry data demonstrate that AQP1 was clearly expressed in the ectodermal and endodermal epithelia, the vascular endothelium, and the VSMCs. Because little information is available on the behavior of microvessel AQP1 during angiogenesis in normal and pathological conditions, our data relative to the pattern of expression of AQP1 in CAM blood vessels in normal conditions may be considered a useful tool to further investigate its modifications in several experimental conditions implying a stimulation or an inhibition of angiogenesis in the CAM assay. Copyright 2002 Wiley-Liss, Inc.

  7. IN VIVO TOXICITY ASSESSMENT OF SILICA NANOPARTICLES IN CHICK EMBRYO

    Directory of Open Access Journals (Sweden)

    Chandrapragasam Vani

    2013-09-01

    Full Text Available Silica is one of the most effective stored seedand food grain protecting pesticide agent, usedfor ages Silica nanoparticles are hard and strong andresistant to brittle fracture under an imposed stress. The aim of our study is to synthesize and evaluate the toxicity of silica nanoparticles at various concentrations using chick embryo, as it serves as a bridging model between in vivo and ex vivo studies. Silica nanoparticles of 70 nm sizewith concentrations of 10, 20, 40 and 80 PPM were injected in vivo and incubated for 19 days as per IACUC guidelines. The study was carried out on dissected chick embryo after the 19th day of incubation. Vital tissues such as liver and heart tissues were subjected to toxicity assays. Biochemical assay of antioxidant enzymes like superoxide dismutase and glutathione peroxide were assessed. The results showed a decreased level of MDA (Malondialdehyde, an end product of lipid Peroxidation, whereas increased activity of superoxide dismutase and glutathione peroxide were observed. Therefore silica nanoparticles may be used as a pesticide and also as a biomaterial for therapeutic application in the field of medicine.

  8. Thioredoxin-2 Modulates Neuronal Programmed Cell Death in the Embryonic Chick Spinal Cord in Basal and Target-Deprived Conditions.

    Directory of Open Access Journals (Sweden)

    Marc Pirson

    Full Text Available Thioredoxin-2 (Trx2 is a mitochondrial protein using a dithiol active site to reduce protein disulfides. In addition to the cytoprotective function of this enzyme, several studies have highlighted the implication of Trx2 in cellular signaling events. In particular, growing evidence points to such roles of redox enzymes in developmental processes taking place in the central nervous system. Here, we investigate the potential implication of Trx2 in embryonic development of chick spinal cord. To this end, we first studied the distribution of the enzyme in this tissue and report strong expression of Trx2 in chick embryo post-mitotic neurons at E4.5 and in motor neurons at E6.5. Using in ovo electroporation, we go on to highlight a cytoprotective effect of Trx2 on the programmed cell death (PCD of neurons during spinal cord development and in a novel cultured spinal cord explant model. These findings suggest an implication of Trx2 in the modulation of developmental PCD of neurons during embryonic development of the spinal cord, possibly through redox regulation mechanisms.

  9. Cell death, cell proliferation, and estimates of hair cell life spans in the vestibular organs of chicks.

    Science.gov (United States)

    Kil, J; Warchol, M E; Corwin, J T

    1997-12-01

    We have examined the level of on-going cell death in the chick vestibular epithelia using the TUNEL method and compared this to the rate of on-going cell proliferation. Utricles contained 22.6 +/- 6.8 TUNEL-labeled cells (mean +/- s.e.m.) while saccules contained 15.1 +/- 4.0, with approximately 90% being labeled hair cells. In separate experiments, chicks were given a single injection of BrdU and killed 2 h later. Utricles contained 116.9 +/- 6.5 BrdU-labeled cells (mean +/- s.e.m.) and saccules contained 41.0 +/- 2.2. After 24 h in culture, utricles treated with 1 mM neomycin contained 115.5 +/- 38.9 TUNEL-labeled cells, an increase of 270% over controls. After 48 h, neomycin-treated saccules contained 40.9 +/- 7.8, an increase of 152% over controls. The majority of labeled cells were in the hair cell layer. Thus, neomycin exposure results in an apoptotic death of hair cells. The in vivo data measured here were used to estimate that the average life span of utricular hair cells in young chickens is approximately 20 days, in sharp contrast to the life spans assumed for hair cells in humans.

  10. Brazilian Green Propolis Protects against Retinal Damage In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Yuta Inokuchi

    2006-01-01

    Full Text Available Propolis, a honeybee product, has gained popularity as a food and alternative medicine. Its constituents have been shown to exert pharmacological (anticancer, antimicrobial and anti-inflammatory effects. We investigated whether Brazilian green propolis exerts neuroprotective effects in the retina in vitro and/or in vivo. In vitro, retinal damage was induced by 24 h hydrogen peroxide (H2O2 exposure, and cell viability was measured by Hoechst 33342 and YO-PRO-1 staining or by a resazurin–reduction assay. Propolis inhibited the neurotoxicity and apoptosis induced in cultured retinal ganglion cells (RGC-5, a rat ganglion cell line transformed using E1A virus by 24 h H2O2 exposure. Propolis also inhibited the neurotoxicity induced in RGC-5 cultures by staurosporine. Regarding the possible underlying mechanism, in pig retina homogenates propolis protected against oxidative stress (lipid peroxidation, as also did trolox (water-soluble vitamin E. In mice in vivo, propolis (100 mg kg−1; intraperitoneally administered four times reduced the retinal damage (decrease in retinal ganglion cells and in thickness of inner plexiform layer induced by intravitreal in vivo N-methyl-d-aspartate injection. These findings indicate that Brazilian green propolis has neuroprotective effects against retinal damage both in vitro and in vivo, and that a propolis-induced inhibition of oxidative stress may be partly responsible for these neuroprotective effects.

  11. PROPERTIES OF PROLIFERATION AND DIFFERENTIATION OF NEONATAL RAT RETINAL PROGENITOR CELLS IN VITRO

    Institute of Scientific and Technical Information of China (English)

    Kang Qianyan; Liu Yong; Zhao Jianjun; Qiu Fen; Chen Xinlin; Tian Yumei; Hu Ming

    2006-01-01

    Objective To investigate the properties of proliferation and differentiation of neonatal rat retinal progenitor cells (RPCs) in vitro. Methods RPCs were isolated from neonatal SD rats neural retina and cultured in DMEM/F12+N2 with EGF and bFGF (suspension medium )or 10%FBS without EGF and bFGF (differentiation medium). The cells grew as suspended spheres or adherent monolayers, depending on different culture conditions. The neural stem cells or retinal progenitors, neurons, astrocytes, retinal ganglion cells, rod photoreceptors and the proliferating cells were evaluated with immunofluorescence analysis by Nestin or Pax6, Map2, GFAP, Thy-1, Rhodopsin and BrdU antibodies respectively. Results RPCs could propagate and differentiate in suspension or differentiation medium and express the markers of Nestin (92.86%) or Pax6 (86.75%), Map2 (38.54%), GFAP (20.93%), Thy-1 (27.66%) and Rhodopsin(13.33%)in suspension medium; however, Nestin (60.27%), Pax6 (52%), Map2 (34.94%), GFAP (38.17%), Thy-1(30.84%) and Rhodopsin (34.67%) in differentiation medium. 96.4% of the population in the neurospheres was BrdU-positive cells. The cells could spontaneously adherent forming some subspheres and retinal specific cell types. Conclusion Neonatal rat RPCs possess the high degree of proliferation and can differentiate into neurons, astrocytes, retinal ganglion cells and rod photoreceptors in vitro. There are different proportions for RPCs to differentiate into specific cell types.

  12. Aldose Reductase Inhibition Prevents Endotoxin-Induced Inflammatory Responses in Retinal Microglia

    Science.gov (United States)

    Chang, Kun-Che; Ponder, Jessica; LaBarbera, Daniel V.; Petrash, J. Mark

    2014-01-01

    Purpose. Retinal microglia become activated in diabetes and produce pro-inflammatory molecules associated with changes in retinal vasculature and increased apoptosis of retinal neurons and glial cells. We sought to determine if the action of aldose reductase (AR), an enzyme linked to the pathogenesis of diabetic retinopathy, contributes to activation of microglial cells. Methods. Involvement of AR in the activation process was studied using primary cultures of retinal microglia (RMG) isolated from wild-type and AR-null mice, or in mouse macrophage cultures treated with either AR inhibitors or small interfering RNA (siRNA) directed to AR. Inflammatory cytokines were measured by ELISA. Cell migration was measured using a transwell assay. Gelatin zymography was used to detect active matrix metalloproteinase (MMP)-9, while RMG-induced apoptosis of adult retinal pigment epithelium (ARPE-19) cells was studied in a cell coculture system. Results. Aldose reductase inhibition or genetic deficiency substantially reduced lipopolysacharide (LPS)-induced cytokine secretion from macrophages and RMG. Aldose reductase inhibition or deficiency also reduced the activation of MMP-9 and attenuated LPS-induced cell migration. Additionally, blockade of AR by sorbinil or through genetic means caused a reduction in the ability of activated RMG to induce apoptosis of ARPE-19 cells. Conclusions. These results demonstrate that the action of AR contributes to the activation of RMG. Inhibition of AR may be a therapeutic strategy to reduce inflammation associated with activation of RMG in disease. PMID:24677107

  13. In vitro phagocytosis of collagens by immortalised human retinal Muller cells

    NARCIS (Netherlands)

    Ponsioen, Theodorus Leonardus; van Luyn, Marja Johanna Adriana; van der Worp, Roelofje Jacoba; Nolte, Ilja Maria; Hooymans, Johanna Martina Maria; Los, Leonoor Inge

    2007-01-01

    Purpose: This study is a first step to investigate phagocytosis of collagens by human retinal Muller cells, since Muller cells could be involved in remodelling of the vitreous and vitreoretinal interface in the human eye. Methods: Muller cells in culture were exposed to 2.0 mu m fluorescent latex be

  14. Raphe of the posterior neural tube in the chick embryo: its closure and reopening as studied in living embryos with a high definition light microscope.

    Science.gov (United States)

    van Straaten, H W; Jaskoll, T; Rousseau, A M; Terwindt-Rouwenhorst, E A; Greenberg, G; Shankar, K; Melnick, M

    1993-09-01

    Chick embryos cultured on a curved substratum show a transient enlargement of the posterior neuropore (PN), mimicking the temporary delay of PN closure as seen in the curly tail (ct) mouse mutant (van Straaten et al. [1993] Development 117:1163-1172). In the present study the PN enlargement in the chick embryo was investigated further with a high definition light microscope (HDmic), allowing high resolution viewing of living embryos in vitro. The temporary PN enlargement appeared due to considerable reopening of the raphe of the posterior neural tube, which was followed by reclosure after several hours. The raphe was subsequently studied in detail. It appeared very irregular, with small zones of apposed, open and fused neural folds. During closure, these raphe features shifted posteriorly. A distinct fusion sequence between surface epithelium and neuroepithelium was not seen. During experimental reopening of the raphe in vitro, small bridges temporarily arose, broke and disappeared quickly; they likely represented the first adhesion sites between the neural folds. More prominent adhesion sites partly detached, resulting in bridging filopodia-like connections; they probably represented the first anteroposterior locations of neural fold fusion. Our observations in the living chick embryo in vitro thus show that the caudal neural tube has an irregular raphe with few adhesion sites, which can be readily reopened. As a result of the irregularity, the PN does not close zipper-like, but button-like by forming multiple closure sites.

  15. Veratridine increases the survival of retinal ganglion cells in vitro

    Directory of Open Access Journals (Sweden)

    S.P.F. Pereira

    1997-12-01

    Full Text Available Neuronal cell death is an important phenomenon involving many biochemical pathways. This degenerative event has been studied to understand how the cells activate the mechanisms that lead to self-destruction. Target cells and afferent cells play a relevant role in the regulation of natural cell death. We studied the effect of veratridine (1.5, 3.0, 4.5 and 6.0 µM on the survival of neonatal rat retinal ganglion cells in vitro. Veratridine (3.0 µM, a well-known depolarizing agent that opens the Na+ channel, promoted a two-fold increase in the survival of retinal ganglion cells kept in culture for 48 h. This effect was dose-dependent and was blocked by 1.0 µM tetrodotoxin (a classical voltage-dependent Na+ channel blocker and 30.0 µM flunarizine (a Na+ and Ca2+ channel blocker. These results indicate that electrical activity is also important for the maintenance of retinal ganglion cell survival in vitro

  16. Protective effect of genistein on human retinal pigment epithelium cell cultured in high glucose%金雀异黄素对高糖诱导的人RPE细胞损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    帅捷; 洪瑾; 袁志兰

    2007-01-01

    目的 探讨金雀异黄素(genistein,Gen)对高糖诱导的人视网膜色素上皮(retinal pigment epithelium,RPE)细胞的保护作用.方法 培养人RPE细胞,分别以Gen 0 μmol·L-1、50 μmol·L-1、100 μmol·L-1、200 μmol·L-1的药物浓度作用高糖(33 mmol·L-1)培养的RPE细胞48 h,噻唑蓝比色法检测细胞活性;流式细胞仪检测细胞周期;激光共聚焦显微镜检测细胞内活性氧(reactive oxygen species,ROS)水平;黄嘌呤氧化酶法测定细胞内超氧化物歧化酶(SOD)活性.结果 高糖组细胞活力(0.308±0.022)明显低于正常对照组(0.424±0.014)(P<0.01);高糖+Gen组细胞活力较高糖组升高(P<0.05),且随Gen浓度增大,细胞活力增加更明显.与正常对照组比较,高糖组细胞增殖受到抑制,被阻滞于S期和G2期;与高糖组比较,Gen可减轻高糖对细胞增殖的抑制作用.与正常对照组比较,高糖组细胞内ROS的产生明显增多;Gen以浓度依赖方式抑制高糖组RPE细胞内ROS的产生.与正常对照组(31.04±0.02)比较,高糖组SOD活性(12.32±0.02)显著降低(P<0.01);与高糖组比较,高糖+Gen组SOD活性随Gen浓度的增加而升高(均P<0.05).结论 Gen可保护和修复高糖诱导的人RPE细胞的损伤,其作用可能与抗氧化、增强SOD活性有关.

  17. GABAB1 and GABAB2 receptor subunits co-expressed in cultured human RPE cells regulate intracellular Ca2+ via Gi/o-protein and phospholipase C pathways.

    Science.gov (United States)

    Cheng, Z-Y; Wang, X-P; Schmid, K L; Han, X-G

    2014-11-07

    GABAB receptors associate with Gi/o-proteins that regulate voltage-gated Ca(2+) channels and thus the intracellular Ca(2+) concentration ([Ca(2+)]i), there is also reported cross-regulation of phospholipase C. These associations have been studied extensively in the brain and also shown to occur in non-neural cells (e.g. human airway smooth muscle). More recently GABAB receptors have been observed in chick retinal pigment epithelium (RPE). The aims were to investigate whether the GABAB receptor subunits, GABAB1 and GABAB2, are co-expressed in cultured human RPE cells, and then determine if the GABAB receptor similarly regulates the [Ca(2+)]i of RPE cells and if phospholipase C is involved. Human RPE cells were cultured from five donor eye cups. Evidence for GABAB1 and GABAB2 mRNAs and proteins in the RPE cell cultures was investigated using real time polymerase chain reaction, western blots and immunofluorescence. The effects of the GABAB receptor agonist baclofen, antagonist CGP46381, a Gi/o-protein inhibitor pertussis toxin, and the phospholipase C inhibitor U73122 on [Ca(2+)]i in cultured human RPE were demonstrated using Fluo-3. Both GABAB1 and GABAB2 mRNA and protein were identified in cell cultures of human RPE; antibody staining was co-localized to the cell membrane and cytoplasm. One-hundred micromolars of baclofen caused a transient increase in the [Ca(2+)]i of RPE cells regardless of whether Ca(2+) was added to the buffer. Baclofen-induced increases in the [Ca(2+)]i were attenuated by pre-treatment with CGP46381, pertussis toxin, and U73122. GABAB1 and GABAB2 are co-expressed in cell cultures of human RPE. GABAB receptors in RPE regulate the [Ca(2+)]i via a Gi/o-protein and phospholipase C pathway. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  18. Increased mortality of black-browed albatross chicks at a colony heavily-infested with the tick Ixodes uriae.

    Science.gov (United States)

    Bergström, S; Haemig, P D; Olsen, B

    1999-09-01

    At Bird Island, South Georgia, we studied the effects of the tick Ixodes uriae on survival of chicks at two colonies of the black-browed albatross Diomedea melanophrys, one where most chicks were infested with ticks, the other where most chicks were tick-free. When the two colonies were compared, it was found that the colony heavily-infested with ticks had significantly greater chick mortality than the colony lightly-infested with ticks. However, within each of the two colonies, there was no significant difference in survival between chicks with ticks and those without ticks.

  19. In vitro neurotoxic effects of 1 GeV/n iron particles assessed in retinal explants.

    Science.gov (United States)

    Vazquez, M E; Kirk, E

    2000-01-01

    The heavy ion component of the cosmic radiation remains problematic to the assessment of risk in manned space flight. The biological effectiveness of HZE particles has yet to be established, particularly with regard to nervous tissue. Using heavy ions accelerated at the AGS of Brookhaven National Laboratory, we study the neurotoxic effects of iron particles. We exposed retinal explants, taken from chick embryos, to determine the dose response relationships for neurite outgrowth. Morphometric techniques were used to evaluate the in vitro effects of 1 GeV/a iron particles (LET 148 keV/micrometer). Iron particles produced a dose-dependent reduction of neurite outgrowth with a maximal effect achieved with a dose of 100 cGy. Doses as low as 10-50 cGy were able to induce reductions of the neurite outgrowth as compared to the control group. Neurite generation is a more sensitive parameter than neurite elongation, suggesting different mechanism of radiation damage in our model. These results showed that low doses/fluences of iron particles could impair the retinal ganglion cells' capacity to generate neurites indicating the highly neurotoxic capability of this heavy charged particle.

  20. The trophic effect of ouabain on retinal ganglion cells is mediated by IL-1β and TNF-α

    Energy Technology Data Exchange (ETDEWEB)

    Salles von-Held-Ventura, Juliana; Mázala-de-Oliveira, Thalita; Cândida da Rocha Oliveira, Amanda; Granja, Marcelo Gomes [Departamento de Neurobiologia, Programa de Neurociências, Outeiro de São João Batista s/n CEP: 24020-150, Universidade Federal Fluminense, Niterói, RJ (Brazil); Gonçalves-de-Albuquerque, Cassiano Felippe; Castro-Faria-Neto, Hugo Caire [Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Departamento de Fisiologia e Farmacodinâmica, Av., no 4365, Manguinhos, 21045-900, Rio de Janeiro, RJ (Brazil); Giestal-de-Araujo, Elizabeth, E-mail: egiestal@vm.uff.br [Departamento de Neurobiologia, Programa de Neurociências, Outeiro de São João Batista s/n CEP: 24020-150, Universidade Federal Fluminense, Niterói, RJ (Brazil)

    2016-09-09

    Ouabain is a steroid hormone that binds to the enzyme Na{sup +}, K{sup +} – ATPase and stimulates different intracellular pathways controlling growth, proliferation and cell survival. IL-1β and TNF-α are pleiotropic molecules, conventionally regarded as pro-inflammatory cytokines with well-known effects in the immune system. In addition, IL-1β and TNF-α also play important roles in the nervous system including neuroprotective effects. Previous data from our group showed that ouabain treatment is able to induce an increase in retinal ganglion cell survival kept in mixed retinal cell cultures. The aim of this work was to investigate if IL-1β and TNF-α could be mediating the trophic effect of ouabain on retinal ganglion cells. Our results show that the trophic effect of ouabain on retinal ganglion cell was inhibited by either anti-IL-1β or anti-TNF-α antibodies. In agreement, IL-1β or TNF-α increased the retinal ganglion cells survival in a dose-dependent manner. Accordingly, ouabain treatment induces a temporal release of TNF-α and IL-1β from retinal cell cultures. Interestingly, TNF-α and IL-1β regulate each other intracellular levels. Our results suggest that ouabain treatment triggers the activation of TNF-α and IL-1β signaling pathways leading to an increase in retinal ganglion cell survival. - Highlights: • Pro-inflammatory cytokines regulates the ouabain effect on RGC survival. • Ouabain treatment modulates the intracellular levels of TNF-α and IL-1β. • Ouabain induces the release of TNF-α and IL-1β in retinal cell cultures.

  1. Retinal vessel tortuosity associated with central retinal vein occlusion: an optical coherence tomography study.

    Science.gov (United States)

    Muraoka, Yuki; Tsujikawa, Akitaka; Kumagai, Kyoko; Akagi-Kurashige, Yumiko; Ogino, Ken; Murakami, Tomoaki; Miyamoto, Kazuaki; Yoshimura, Nagahisa

    2014-01-07

    We studied morphologic changes of the retinal vasculature in eyes with central retinal vein occlusion (CRVO) through the use of optical coherence tomography (OCT). Major retinal vessels in 35 eyes from 35 consecutive patients with acute CRVO were examined prospectively and longitudinally with sequential thin sectioning and circumpapillary scanning. Anteroposterior venous tortuosity associated with CRVO was quantified on longitudinal OCT images of a randomly selected major temporal vein. On OCT sections of a given vein, we identified the innermost and outermost points of the vessel wall. The degree of anteroposterior venous tortuosity was defined as the difference between the vertical distances from the retinal pigment epithelium to the center of the venous lumen at these two points. The OCT images revealed that the major retinal veins traveled tortuously through the swollen neurosensory retina from the inner retinal surface to the retinal pigment epithelium. The degree of anteroposterior venous tortuosity was correlated with poor visual acuity (r = 0.457, P = 0.017), increased mean foveal thickness (r = 0.671, P retinal detachment was detected around the optic disc, which correlated with anteroposterior venous tortuosity. In 14 (40%) eyes, elongated major retinal veins disrupted the boundary between retinal vessels and parenchyma, which resulted in juxtavenous splitting of the neurosensory retina. In eyes with CRVO, OCT can be used to visualize anteroposterior venous tortuosity and associated structural changes to the retinal parenchyma.

  2. Retinal vascular oximetry during ranibizumab treatment of central retinal vein occlusion

    DEFF Research Database (Denmark)

    Traustason, Sindri; la Cour, Morten; Larsen, Michael

    2014-01-01

    PURPOSE: To investigate the effect of intravitreal injections of the vascular endothelial growth factor inhibitor ranibizumab on retinal oxygenation in patients with central retinal vein occlusion (CRVO). METHODS: Retinal oxygen saturation in patients with CRVO was analysed using the Oxymap Retinal...... in eyes with CRVO than in the fellow eyes (95%±8% and 91%±3%, p=0.04). Mean visual acuity increased from 51±24 letters ETDRS at baseline to 66±24 and 69±20 letters ETRDS, respectively, at 3 months and 6 months treatment (mean±SD, pcentral retinal...... Oximeter P3, before and during 6 months of treatment with intravitreal injections of ranibizumab. RESULTS: At presentation, retinal venous oxygen saturation was lower in eyes with CRVO than in the healthy fellow eyes (32±13% vs 59±10%, respectively, p=0.001) whereas retinal arterial saturation was higher...

  3. Face recognition in newly hatched chicks at the onset of vision.

    Science.gov (United States)

    Wood, Samantha M W; Wood, Justin N

    2015-04-01

    How does face recognition emerge in the newborn brain? To address this question, we used an automated controlled-rearing method with a newborn animal model: the domestic chick (Gallus gallus). This automated method allowed us to examine chicks' face recognition abilities at the onset of both face experience and object experience. In the first week of life, newly hatched chicks were raised in controlled-rearing chambers that contained no objects other than a single virtual human face. In the second week of life, we used an automated forced-choice testing procedure to examine whether chicks could distinguish that familiar face from a variety of unfamiliar faces. Chicks successfully distinguished the familiar face from most of the unfamiliar faces-for example, chicks were sensitive to changes in the face's age, gender, and orientation (upright vs. inverted). Thus, chicks can build an accurate representation of the first face they see in their life. These results show that the initial state of face recognition is surprisingly powerful: Newborn visual systems can begin encoding and recognizing faces at the onset of vision.

  4. Intracerebroventricular administration of chicken glucagon-like peptide-2 potently suppresses food intake in chicks.

    Science.gov (United States)

    Honda, Kazuhisa; Saneyasu, Takaoki; Shimatani, Tomohiko; Aoki, Koji; Yamaguchi, Takuya; Nakanishi, Kiwako; Kamisoyama, Hiroshi

    2015-03-01

    Glucagon-related peptides, such as glucagon-like peptide (GLP)-1, GLP-2 and oxyntomodulin (OXM), are processed from an identical precursor proglucagon. In mammals, all of these peptides are suggested to be involved in the central regulation of food intake. We previously showed that intracerebroventricular administration of chicken OXM and GLP-1 significantly suppressed food intake in chicks. Here, we show that central administration of chicken GLP-2 potently suppresses food intake in chicks. Male 8-day-old chicks (Gallus gallus domesticus) were used in all experiments. Intracerebroventricular administration of chicken GLP-2 significantly suppressed food intake in chicks. Plasma glucose concentration was significantly decreased by chicken GLP-2, whereas plasma nonesterified fatty acid concentration was significantly increased. Intracerebroventricular administration of chicken GLP-2 did not affect plasma corticosterone concentration. In addition, the anorexigenic effect of GLP-2 was not reversed by the corticotropin-releasing factor (CRF) receptor antagonist α-helical CRF, suggesting that CRF is not a downstream mediator of the anorexigenic pathway of GLP-2 in chicks. Intracerebroventricular administration of an equimolar amount of GLP-1 and GLP-2, but not OXM, significantly suppressed food intake in both broiler and layer chicks. All our findings suggest that GLP-2 functions as a potent anorexigenic peptide in the brain, as well as GLP-1, in chicks.

  5. Lead exposure in Laysan albatross adults and chicks in Hawaii: prevalence, risk factors, and biochemical effects.

    Science.gov (United States)

    Work, T M; Smith, M R

    1996-07-01

    Prevalence of lead exposure and elevated tissue lead was determined in Laysan albatross (Diomedea immutabilis) in Hawaii. The relationship between lead exposure and proximity to buildings, between elevated blood lead and droopwing status, and elevated liver lead and presence of lead-containing paint chips in the proventriculus in albatross chicks was also examined. Finally, the effects of lead on the enzyme delta-aminolevulinic acid dehydratase (ALAD) was determined. There was a significant association between lead exposure or elevated tissue lead and proximity to buildings in albatross chicks and presence of lead paint chips in the proventriculus and elevated liver lead in carcasses. Although there was a significant association between elevated blood lead and droopwing chicks, there were notable exceptions. Prevalence of elevated tissue lead in albatross chicks was highest on Sand Island Midway and much less so on Kauai and virtually nonexistent in other areas. Prevalence of lead exposure decreased as numbers of buildings to which chicks were exposed on a given island decreased. Laysan albatross adults had minimal to no lead exposure. There was a significant negative correlation between blood lead concentration and ALAD activity in chicks. Based on ALAD activity, 0.03-0.05 microg/ml was the no effect range for blood lead in albatross chicks.

  6. Progesterone-independent avidin induction in chick tissues caused by tissue injury and inflammation.

    Science.gov (United States)

    Elo, H A; Kulomaa, M S; Tuohimaa, P J

    1979-04-01

    Progesterone was administered to oestrogen-treated and untreated chicks, or inflammation in the abdominal cavity was caused by intestine and liver injury or intraperitoneal actinomycin D administration. Local injury to the pectoral muscle was also carried out. Chicks were killed 24--26 h after the treatment and the biotin-binding egg white protein, avidin, was assayed in a number of tissues using a [14C]biotin-binding method and radioimmunoassay. Ovalbumin was also assayed with a radioimmunoassay. Avidin was not found in the tissues of control chicks. Progesterone induced avidin only in the oviducts of oestrogen-treated chicks. After intestine and liver injury avidin was found, however, in all the tissues of oestrogen-treated and untreated chicks studied except for the brain. The concentrations were highest in the oviduct, lung, intestine and bursa of Fabricius. Actinomycin D (200 microgram/kg) caused ascites and subcutaneous oedema in 40--60% of the chicks, and avidin was found only in the tissues of these inflamed animals. Avidin production caused by the local muscular injury was restricted to the injured area. Tissue injury and inflammation did not induce ovalbumin in any tissue. The study shows that avidin can be induced besides the oviduct also in non-oviductal chick tissues, and it is proposed that there are both progesterone-dependent and -independent avidin induction mechanisms.

  7. Brain asymmetry modulates perception of biological motion in newborn chicks (Gallus gallus).

    Science.gov (United States)

    Rugani, Rosa; Rosa Salva, Orsola; Regolin, Lucia; Vallortigara, Giorgio

    2015-09-01

    Few light-points on the joints of a moving animal give the impression of biological motion (BM). Day-old chicks prefer BM to non-BM, suggesting a conserved predisposition to attend to moving animals. In humans and other mammals a network of regions, primarily in the right hemisphere, provides the neural substrate for BM perception. However, this has not been investigated in avians. In birds the information from each eye is mainly feeding to the contralateral hemisphere. To study brain asymmetry, we recorded the eye spontaneously used by chicks to inspect a BM stimulus. We also investigated the effect of lateralization following light exposure of the embryos. In Experiment 1, highly lateralized chicks aligned with the apparent direction of motion only when they were exposed to a BM-stimulus moving rightward first, monitoring it with the left-eye-system. In Experiment 2 weakly lateralized chicks did not show any behavioral asymmetry. Moreover, they counter aligned with the apparent direction of motion. Brain lateralization affects chicks behavior while processing and approaching a BM stimulus. Highly lateralized chicks aligned their body with the apparent direction of the BM, a behavior akin to a following response, monitoring the stimulus preferentially with their left eye. This suggests a right hemisphere dominance in BM processing. Weakly lateralized chicks counter-aligned with the apparent direction of the BM, facing it during interaction, and monitored it equally with both eyes. Environmental factors (light stimulation) seem to affect the development of lateralization, and consequently social behavior.

  8. Lead exposure in Laysan albatross adults and chicks in Hawaii: prevalence, risk factors, and biochemical effects.

    Science.gov (United States)

    Work, T.M.; Smith, M.R.

    1996-01-01

    Prevalence of lead exposure and elevated tissue lead was determined in Laysan albatross (Diomedea immutabilis) in Hawaii. The relationship between lead exposure and proximity to buildings, between elevated blood lead and droopwing status, and elevated liver lead and presence of lead-containing paint chips in the proventriculus in albatross chicks was also examined. Finally, the effects of lead on the enzyme δ-amino-levulinic acid dehydratase (ALAD) was determined. There was a significant association between lead exposure or elevated tissue lead and proximity to buildings in albatross chicks and presence of lead paint chips in the proventriculus and elevated liver lead in carcasses. Although there was a significant association between elevated blood lead and droopwing chicks, there were notable exceptions. Prevalence of elevated tissue lead in albatross chicks was highest on Sand Island Midway and much less so on Kauai and virtually nonexistent in other areas. Prevalence of lead exposure decreased as numbers of buildings to which chicks were exposed on a given island decreased. Laysan albatross adults had minimal to no lead exposure. There was a significant negative correlation between blood lead concentration and ALAD activity in chicks. Based on ALAD activity, 0.03-0.05 μg/ml was the no effect range for blood lead in albatross chicks.

  9. Competition with a host nestling for parental provisioning imposes recoverable costs on parasitic cuckoo chick's growth.

    Science.gov (United States)

    Geltsch, Nikoletta; Hauber, Márk E; Anderson, Michael G; Bán, Miklós; Moskát, Csaba

    2012-07-01

    Chicks of the brood parasitic common cuckoo (Cuculus canorus) typically monopolize host parental care by evicting all eggs and nestmates from the nest. To assess the benefits of parasitic eviction behaviour throughout the full nestling period, we generated mixed broods of one cuckoo and one great reed warbler (Acrocephalus arundinaceus) to study how hosts divide care between own and parasitic young. We also recorded parental provisioning behaviour at nests of singleton host nestlings or singleton cuckoo chicks. Host parents fed the three types of broods with similar-sized food items. The mass of the cuckoo chicks was significantly reduced in mixed broods relative to singleton cuckoos. Yet, after the host chick fledged from mixed broods, at about 10-12 days, cuckoo chicks in mixed broods grew faster and appeared to have compensated for the growth costs of prior cohabitation by fledging at similar weights and ages compared to singleton cuckoo chicks. These results are contrary to suggestions that chick competition in mixed broods of cuckoos and hosts causes an irrecoverable cost for the developing brood parasite. Flexibility in cuckoos' growth dynamics may provide a general benefit to ecological uncertainty regarding the realized successes, failures, and costs of nestmate eviction strategies of brood parasites.

  10. Penguin chicks benefit from elevated yolk androgen levels under sibling competition.

    Directory of Open Access Journals (Sweden)

    Maud Poisbleau

    Full Text Available Crested penguins (genus Eudyptes have a peculiar hatching pattern, with the first-laid egg (A-egg hatching after the second-laid egg (B-egg and chicks from A-eggs typically having a much lower survival probability. Maternal yolk androgens have been suggested to contribute to the competitive superiority of the B-chick in southern rockhopper penguins Eudyptes chrysocome, given their important role in mediating sibling competition in other species. We therefore increased the yolk androgen levels in freshly-laid eggs and examined the consequences for sibling competition--via effects on embryonic developmental times, chick growth and early survival. We placed one androgen-treated egg and one control egg into each foster nest, matching them for mass, laying date and laying order. The androgen treatment did not significantly affect embryonic developmental times or chick measurements at hatching. However, elevated yolk androgen levels benefitted chick growth in interaction with the number of siblings in a brood. Chicks from androgen-treated eggs had faster growth in the presence of a sibling than chicks from control eggs. Under these circumstances they also had a higher survival probability. Thus maternal androgens appear to reinforce the observed hatching pattern, facilitating brood reduction. This contrasts to most previous studies in other species where yolk androgens have been shown to compensate for the negative consequences of delayed hatching within the brood hierarchy.

  11. Efficiency of manganese absorption in chicks fed corn-soy and casein diets.

    Science.gov (United States)

    Halpin, K M; Chausow, D G; Baker, D H

    1986-09-01

    Experiments were conducted with young chicks to quantify the absorption efficiency of manganese (Mn) using tibia Mn uptake as the response criterion. Chicks in experiment 1 were fed a corn-soybean meal diet and either injected intraperitoneally or crop intubated twice daily with three levels of inorganic Mn provided as MnSO4 X H2O. After 14 d, chicks were killed, and intact tibias were removed to facilitate calculation of bone Mn concentration. Excellent straight-line fits (bone Mn concentration as a function of Mn administered) allowed estimation of gut absorption efficiency of Mn by slope-ratio methodology. Absorption efficiency of Mn was calculated to be 1.71% for chicks fed the corn-soy diet. Identical methodology was employed in experiment 2 wherein chicks were fed a phytate- and fiber-free casein-dextrose diet. An absorption efficiency of 2.40% was estimated for chicks fed this diet. Hence, absorption efficiency of inorganic Mn was 40% greater in chicks fed the purified diet than in those fed the conventional corn-soy diet.

  12. Migratory mechanisms of chick primordial germ cells toward gonadal anlage.

    Science.gov (United States)

    Kuwana, T; Rogulska, T

    1999-07-01

    After appearing at the germinal crescent region, chick primordial germ cells (PGCs) migrate toward the presumptive gonads (pG) till stage 19 (Hamburger and Hamilton, 1951). This study seeks to elucidate the roles of passive and active factors in the PGC-migration, physical trapping of circulating PGCs by the capillary network and PGC attraction by chemotactic factor from presumptive gonads. Firstly, latex beads/pollens (the same size or larger than PGCs) were injected into the embryonic bloodstream at stage 13-19 (when PGCs are in the migrating and settlement phase to the presumptive gonad) in ovo in order to determine whether the PGCs passively reach pG. Most of such particles accumulated in the head region (60%), whereas the remainder did the same in the gonadal region (23% at the peak) at stage 16 when both the head and gonadal regions are rich in capillary plexus. After 3 days, most particles in the gonadal region were located at the angles of dorsal mesentery near the developing gonads where many extra-gonadal PGCs had been located, and a few particles were detected close to the gonad. These results suggest that one of the mechanisms of PGC-migration to the developing gonads is an autonomous trapping of PGCs by the capillary network quite close to the germinal epithelium (GE) and passive translocation by morphogenetic movement. Secondly, the attraction for PGCs by the gonadal anlage proper was examined in ovo using chick and quail embryos. Grafts of quail gonadal anlage containing gonadal epithelium and neighbouring mesenchymal tissue were excised from the quail embryo at stages 12 to 16 (staging by Zacchei, 1961). With the aims of eliminating the influence of surrounding tissue, the quail graft was ectopically transplanted into the posterior to the optic vesicle of 8 to 17 somite chick embryo from the point of a posterior region to the auditory vesicle by a fine tungsten needle under the illumination by the method of Hara (1971). Then the region posterior to

  13. Postnatal visual deprivation in rats regulates several retinal genes and proteins, including differentiation-associated fibroblast growth factor-2.

    Science.gov (United States)

    Prokosch-Willing, Verena; Meyer zu Hoerste, Melissa; Mertsch, Sonja; Stupp, Tobias; Thanos, Solon

    2015-01-01

    Little is known about the retinal cellular basis of amblyopia, which is a developmental disease characterized by impaired visual acuity. This study examined the retinal transcripts associated with experimentally induced unilateral amblyopia in rats. Surgical tarsorrhaphy of the eyelids on one side was performed in pups prior to eye opening at postnatal day 14, thereby preventing any visual experience. This condition was maintained for over 2 months, after which electroretinograms (ERGs) were recorded, the retinal ganglion cell (RGC) arrangement and number were determined using neuroanatomical tracing, the retinal transcripts were studied using microarray analysis, regulated mRNAs were confirmed with quantitative reverse-transcriptase PCR, and proteins were stained using Western blotting and immunohistochemistry. An attenuated ERG was found in eyes that were deprived of visual experience. Retrograde neuroanatomical staining disclosed a larger number of RGCs within the retina on the visually deprived side compared to the non-deprived, control side, and a multilayered distribution of RGCs. At the retinomic level, several transcripts associated with retinal differentiation, such as fibroblast growth factor 2 (FGF-2), were either up- or downregulated. Most of the transcripts could be verified at the mRNA level. To unravel the role of a differentiation-associated protein, we tested FGF-2 in dissociated postnatal retinal cell cultures and found that FGF-2 is a potent factor triggering ganglion cell differentiation. The data suggest that visual experience shapes the postnatal retinal differentiation, whereas visual deprivation induces changes at the functional, cellular and molecular levels within the retina.

  14. Is the capacity for optic nerve regeneration related to continued retinal ganglion cell production in the frog?

    Science.gov (United States)

    Taylor, J S; Jack, J L; Easter, S S

    1989-01-01

    In the central nervous system of fish and frogs, some, but not all, axons can regenerate. Retinal ganglion cells are among those that can. The retinae of fish and frogs produce new retinal neurons, including ganglion cells, for months or years after hatching. We have evaluated the hypothesis that retinal axonal regeneration is obligatorily linked to continued production of new ganglion cells. We used bromodeoxyuridine immunocytochemistry to assess retinal neurogenesis in juvenile, yearling, and 10 year old Xenopus laevis. Retinal ganglion cell genesis was vigorous in the marginal retina of the juveniles, but in the yearlings and the 10 year olds, no new ganglion cells were produced there. Cellular proliferation in the central retina was evident at all three ages, but none of the cells produced centrally were in the ganglion cell layer. Regeneration was examined in vivo by cutting one optic nerve and then, weeks later, injecting the eye with tritiated proline. Autoradiographs of brain sections showed that the optic nerves of all three ages regenerated. Regeneration in vitro was assessed using retinal explants from frogs of all three ages. In all cases, the cultures produced neurites, with some age-specific differences in the patterns of outgrowth. We conclude that retinal axonal regeneration is not linked obligatorily to maintained neurogenesis.

  15. Effects of prenatal exposure to antithyroid drugs on imprinting behavior in chicks.

    Science.gov (United States)

    Kagami, Keisuke; Nishigori, Hidekazu; Nishigori, Hideo

    2010-09-01

    Thyroid hormones play important roles in vertebrate brain development. However, there is little understanding of the direct effects of fetal thyroid dysfunction, i.e., not acquired through the mother, on learning ability. In the present study, we use a chick embryo as a fetal model to investigate the effects of prenatal exposure to antithyroid drugs on imprinting behavior in hatched chicks. Methimazole (MMI) at 20micromol/egg or 5micromol/egg of propylthiouracil (PTU) was administered to eggs on day 14 while the control was given only a vehicle. An imprinting test was conducted after the chicks hatched. Day-old chicks were exposed to a rotating training object for 150min. The next day, the trained chicks were exposed to the training object and a novel object. The imprinting preference was represented as a preference score (PS) calculated as the rate of following the training object to following the training and novel objects. In the MMI-treated chicks, the PS was 0.68+/-0.06 (range, 0.38-0.88), which was significantly lower than that in the control chicks (0.86+/-0.04, p<0.01). In the PTU-treated chicks, the PS was 0.69+/-0.04 (range, 0.52-0.89), which was also significantly lower than that in the control (0.88+/-0.02, p<0.001). The present findings suggested that fetal thyroid dysfunction inhibited brain development, leading to impaired learning and memory. Our chick model can be considered useful for investigating the direct effects of prenatal exposure to antithyroid drugs or substances in the environment on learning ability after birth. Copyright 2010 Elsevier Inc. All rights reserved.

  16. Social facilitation revisited: increase in foraging efforts and synchronization of running in domestic chicks.

    Science.gov (United States)

    Ogura, Yukiko; Matsushima, Toshiya

    2011-01-01

    Social influences on foraging efforts were examined in domestic chicks by investigating the frequency of runs made to feeders and the amount of pecking to gain food. Single or paired chicks foraged in an I-shaped maze equipped with a millet feeder on each end, that distributed one or two grains at variable intervals. Regardless of when the grain(s) were dispensed, chicks ran back and forth between the feeders. Analyses of their movement patterns revealed: (1) running patterns were not directly synchronized with the dispensing of grain(s), (2) running distance was longer in paired chicks than in single chicks, (3) paired chicks partially synchronized their runs between feeders, and (4) social effects were immediate but cumulative after repeated blocks. We further examined the social effects on running by dividing the I-maze into two parallel lanes separated by a transparent wall, so that kleptoparasitic interference of food did not occur. Again, the chicks increased their running speed and were even more synchronized with their partner's movements, indicating that food competition alone was not responsible for increased foraging effort. The number of pecks to get grains was also assessed under conditions where the food tray was gradually replaced, from an easy one to more difficult ones. When tested in the separated I-maze, paired chicks pecked more in the difficult food situation without increase in the number of gained grains. Results suggest that (i) social facilitation leads to increased foraging efforts and (ii) the presence of a conspecific is alone may lead to enhanced foraging efforts in chicks. These findings are discussed in terms of possible ecological background of social facilitation.

  17. Organochlorines accumulate in heron and egret chicks sampled in the Houston Ship Channel

    Science.gov (United States)

    Custer, T.W.; Shipley, Frank S.; Kiesling, Russell W.

    1991-01-01

    The National Contaminant Monitoring Program (NCBP) is an effort of the U.S. Fish and Wildlife Service to measure concentrations of DDT and other persistent chemicals in the environment and to quantify changes in these levels. The NCBP has established a network of sampling stations in segments of the environment for which Federal agencies have authority. The wildlife component of this program, administered by the Patuxent Wildlife Research Center, includes the periodic sampling of European starlings (Sturnus vulgaris), mallards (Anas platyrhynchos), and American black ducks (Anas rubripes). In order to include an estuarine component into the NCBP, herons and egrets are being evaluated. Eggs and chicks (five, ten, and 15 days of age) of snowy egrets (Egretta thula), and black-crowned night-herons (Nycticorax nycticorax) were collected in Naragansett Bay, RI; the Houston Ship Channel (HSC), TX; and San Francisco Bay, CA. Great egret (Casmerodius albus) eggs and chicks also were collected at the Texas colony. Eggs and chicks were analyzed for organochlorines; trace element and petroleum hydrocarbon analyses are pending. DDE and polychlorinated biphenyls (PCBs) were detected in all eggs and chicks, and they accumulated as the chicks grew. At each location, black-crowned nightheron chicks accumulated both DDE and PCBs more rapidly than snowy egrets or great egrets. PCBs accumulated more rapidly in night-heron chicks in Rhode Island than California; however, PCB accumulation for snowy egret chicks did not differ among locations. Contaminant accumulation rates in heron and egret chicks could be used as a new wetland component of the NCBP.

  18. Argus II retinal prosthesis system: An update.

    Science.gov (United States)

    Rachitskaya, Aleksandra V; Yuan, Alex

    2016-09-01

    This review focuses on a description of the Argus II retinal prosthesis system (Argus II; Second Sight Medical Products, Sylmar, CA) that was approved for humanitarian use by the FDA in 2013 in patients with retinitis pigmentosa with bare or no light perception vision. The article describes the components of Argus II, the studies on the implant, and future directions.

  19. Fundus autofluorescence applications in retinal imaging

    Directory of Open Access Journals (Sweden)

    Andrea Gabai

    2015-01-01

    Full Text Available Fundus autofluorescence (FAF is a relatively new imaging technique that can be used to study retinal diseases. It provides information on retinal metabolism and health. Several different pathologies can be detected. Peculiar AF alterations can help the clinician to monitor disease progression and to better understand its pathogenesis. In the present article, we review FAF principles and clinical applications.

  20. RETINAL VEIN OCCLUSIONS - A CLINICAL STUDY

    Directory of Open Access Journals (Sweden)

    Ramadevi

    2015-11-01

    Full Text Available Retinal vein occlusion is the most common retinal occlusive disorder encountered by opthalmologists and is usually associated with a variable amount of visual loss.The study was conducted over a period of 22 months, we performed a combined analysis of risk factors, clinical presentation, management and complication of these 51 patients

  1. Anatomy of the retinal nerve fiber layer.

    Science.gov (United States)

    Radius, R L; de Bruin, J

    1981-11-01

    Anatomy of the retinal nerve fiber layer in rabbit eyes is studied by light microscopy, transmission electron microscopy, and scanning electron microscopy. It is demonstrated that retinal striations noted ophthalmoscopically in these eyes represent individual fiber bundles, Axon bundles are compartmentalized within tissue tunnels comprised of elongated processes of glial cell origin.

  2. Retinal ischemia and embolism. Causes and outcomes

    NARCIS (Netherlands)

    Wijman, C.A.C.

    2007-01-01

    The ocular fundus allows direct visualization of the retinal vasculature, blood vessels that are part of the cerebral circulation. Unraveling the causes of retinal ischemia may provide further insight in the pathophysiological processes that underlie cerebral ischemia. The primary aim of the studies

  3. Retinal vein occlusion: pathophysiology and treatment options

    OpenAIRE

    Niral Karia

    2010-01-01

    Niral KariaDepartment of Ophthalmology, Southend Hospital, Prittlewell Chase, Westcliff on Sea, Essex, United KingdomAbstract: This paper reviews the current thinking about retinal vein occlusion. It gives an overview of its pathophysiology and discusses the evidence behind the various established and emerging treatment paradigms.Keywords: central, hemispheric, branch, retinal vein occlusion, visual loss

  4. Retinal artery occlusions in children.

    Science.gov (United States)

    Dharmasena, Aruna; Wallis, Simon

    2014-01-01

    The purpose of this study is to present a case of RAO in a 13 year old girl with a preceding history of hyperextension of the neck at her hairdressers for a long duration and use of her mobile phone handset resting it against the side of her neck presumably exerting some pressure on carotids during the same time. Materials and methods of this study was reported as case report and review of literature. A 13 year-old girl presented with the left supero-nasal scotoma due to an inferior temporal branch retinal artery occlusion (BRAO). She underwent extensive investigations and no underlying cause was discovered. She gave a history of cervical extension over a long period of time while having the hair coloured twice in the preceding week. She also mentioned that she was using her mobile phone more or less continuously during both these occasions keeping it against her neck. Given the above history it is possible that the pressure on the ipsilateral carotid arteries or the prolong neck extension may have been responsible for the formation of a platelet embolus resulting in the BRAO. In conclusion, although cerebro-vascular accidents due to 'beauty parlor stroke syndrome' (JAMA 269:2085-2086, 1993) have been reported previously it has not been reported in children to our knowledge. On the other hand, 'beauty parlor stroke syndrome' occurs due to a dissection of the vertebral arteries or due to mechanical compression of the vertebral arteries during the prolonged hyperextension of the neck. The central retinal artery originates from the internal carotid circulation and it is highly unlikely for an embolus to enter the retinal circulation from the vertebral arteries. Therefore, the authors favour the possibility that the compulsive use of a mobile phone exerting pressure on the carotid arteries for a long time may have led to the formation of an embolus and subsequent RAO in this case.

  5. Monitoring phthalates in the tissues of broiler chicks with feedstuffs different phthalate contents

    Directory of Open Access Journals (Sweden)

    Alžbeta Jarošová

    2010-01-01

    Full Text Available For the monitoring of distribution and accumulation of phthalic acid esters (PAE in animal tissues, samples of muscle, mesenteric fat (fat, skin and liver from broiler chicks ROSS 308 were used. The chicks were divided into 4 groups (50 chicks each. All the chicks were given commercial diets (complete feed, KKS for broiler chicks (starter – BR1; grower – BR2 and finisher – BR3. The experimental diets were supplemented with vegetable oil (RO with low (group N or high (group V phthalate contents, or animal fat with a high phthalate content (group Z. Neither the control diets (K, nor the grower (BR1 diets contained vegetable oils or animal fat. The N chicks were given the grower (BR2 and finisher (BR3 diets supplemented with 5% and 3% vegetable oil, respectively. The V chicks were given BR2 and BR3 diets with 5% and 3% vegetable oil, respectively. The Z chicks were given BR2 and BR3 diets with 5% and 3% animal fat, respectively. Di-n-butyl phthalate (DBP and di-(2-ethylhexyl phthalate (DEHP were found in the tissues of chicks in all the experimental groups. The DBP content in the muscle ranged from 0.03 to 0.55 mg . kg−1, in the adipose tissue from < 0.20 to 2.56 mg . kg−1, in the skin from < 0.20 to 1.49 mg . kg−1, and in the liver from 0.03 to 0.13 mg . kg−1. The content of DEHP in the muscle ranged from 0.03 to 1.15 mg . kg−1, in the adipose tissue from 0.25 to 9.85 mg . kg−1, in the skin from < 0.20 to 4.68 mg . kg−1, and in the liver from 0.16 to 0.24 mg . kg−1. The highest concentrations of DBP of 1.28 ± 1.00 mg . kg−1 of fresh sample (an average value from 8 chicks was determined in the adipose tissue of V chicks. The highest concentration of DEHP of 3.27 ± 2.87 mg . kg−1 of fresh sample (mean of 8 chicks was also determined in the V group. The accumulation of DEHP was 3.2; 2.6 and 2.9 times higher than that of DBP in the muscle, adipose tissue and skin

  6. Does soccer ball heading cause retinal bleeding?

    Science.gov (United States)

    Reed, William F; Feldman, Kenneth W; Weiss, Avery H; Tencer, Alan F

    2002-04-01

    To define forces of youth soccer ball heading (headers) and determine whether heading causes retinal hemorrhage. Regional Children's Hospital, youth soccer camp. Male and female soccer players, 13 to 16 years old, who regularly head soccer balls. Dilated retinal examination, after 2-week header diary, and accelerometer measurement of heading a lofted soccer ball. Twenty-one youth soccer players, averaging 79 headers in the prior 2 weeks, and 3 players who did not submit header diaries lacked retinal hemorrhage. Thirty control subjects also lacked retinal hemorrhage. Seven subjects heading the ball experienced linear cranial accelerations of 3.7 +/- 1.3g. Rotational accelerations were negligible. Headers, not associated with globe impact, are unlikely to cause retinal hemorrhage. Correctly executed headers did not cause significant rotational acceleration of the head, but incorrectly executed headers might.

  7. The cell stress machinery and retinal degeneration.

    Science.gov (United States)

    Athanasiou, Dimitra; Aguilà, Monica; Bevilacqua, Dalila; Novoselov, Sergey S; Parfitt, David A; Cheetham, Michael E

    2013-06-27

    Retinal degenerations are a group of clinically and genetically heterogeneous disorders characterised by progressive loss of vision due to neurodegeneration. The retina is a highly specialised tissue with a unique architecture and maintaining homeostasis in all the different retinal cell types is crucial for healthy vision. The retina can be exposed to a variety of environmental insults and stress, including light-induced damage, oxidative stress and inherited mutations that can lead to protein misfolding. Within retinal cells there are different mechanisms to cope with disturbances in proteostasis, such as the heat shock response, the unfolded protein response and autophagy. In this review, we discuss the multiple responses of the retina to different types of stress involved in retinal degenerations, such as retinitis pigmentosa, age-related macular degeneration and glaucoma. Understanding the mechanisms that maintain and re-establish proteostasis in the retina is important for developing new therapeutic approaches to fight blindness.

  8. Prevalence of generalized retinal dystrophy in Denmark

    DEFF Research Database (Denmark)

    Bertelsen, Mette; Jensen, Hanne; Bregnhøj, Jesper F;

    2014-01-01

    of this study was to examine the prevalence and diagnostic spectrum of generalized retinal dystrophy in the Danish population. METHODS: A population-based cross-sectional study with data from the Danish Retinitis Pigmentosa Registry that comprises all patients in Denmark with generalized retinal....... RESULTS: Of the 5,602,628 Danish citizens on January 1, 2013, 1622 patients were registered as having a generalized retinal dystrophy and were alive and living in Denmark, corresponding to a prevalence of 1:3,454. In 28% of cases the eye condition was part of a syndrome, while the remaining 72% had eye...... disease only. Aside from simplex cases (45%), the most common hereditary pattern was autosomal recessive (23%). CONCLUSION: This epidemiological survey demonstrates that the prevalence of generalized retinal dystrophy in the Danish population is 1:3454. Many of the dystrophies are the subjects of clinical...

  9. Bilateral retinitis following typhoid fever

    OpenAIRE

    Prabhushanker, M.; Topiwalla, Tasneem T.; Ganesan, Geetha; Appandaraj, Sripal

    2017-01-01

    Background Post typhoid fever immune related reactions affecting the eye is a rare finding which can have various presentations in which typhoid retinopathy is not a well recognized sequelae. Case presentation Here we present a case of 59?year old male who presented with right eye sudden painless loss of vision 4?weeks after typhoid fever which was diagnosed and treated successfully. His BCVA was 2/60 in right eye and 6/6 in left eye. Fundus examination showed retinitis along with macular ser...

  10. Regenerative Therapy for Retinal Disorders

    Directory of Open Access Journals (Sweden)

    Narsis Daftarian

    2010-01-01

    Full Text Available Major advances in various disciplines of basic sciences including embryology, molecular and cell biology, genetics, and nanotechnology, as well as stem cell biology have opened new horizons for regenerative therapy. The unique characteristics of stem cells prompt a sound understanding for their use in modern regenerative therapies. This review article discusses stem cells, developmental stages of the eye field, eye field transcriptional factors, and endogenous and exogenous sources of stem cells. Recent studies and challenges in the application of stem cells for retinal pigment epithelial degeneration models will be summarized followed by obstacles facing regenerative therapy.

  11. Bilateral Progressive Obliterative Retinal Vasculitis

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    In this paper, 10 cases of a special type of retinal vasculitis are reported, which was characterized by progressive obliteration of vessels in both eyes, developed from the periphery to the posterior ploe, and was complicated by vitreous hemorrhage (5 eyes) and neovascular glaucoma (5 eyes) in later stage. The visual acuity was 0. 05 in 10 eyes (50%). Argon laser pho-tocoagulation seemed to be able to retard the natural course of the disease. Fundus changes, differential diagnosis and treatment etc are...

  12. Fine structure of Plasmodium gallinaceum in embryonic and neonate chicks.

    Science.gov (United States)

    Lushbaugh, W B; McGhee, R B; Singh, S D

    1976-02-01

    The erythrocytic stages of Plasmdoium gallinaceum in chicken embryos injected with parasited blood either from a syringe-passaged infection in chickens or from a chicken infected with sporozoites were characterized by abnormal structure. Particularly evident were large, unstained vacuoles within the cytoplasm; these occurred with greatest frequency in schizonts. The presence of myelin bodies within these vacuoles was revealed by transmission electron microscopy; abnormal cytokinesis and aberrant merozoites provided additional evidence of the parasite's inability to develop naturally within the milieu of the embryonic erythrocytes. Fifty-five passages were necessary to restore normal structure of the parasites in embryos, while only 5 passages were required for such restoration in neonate chicks. The probable adaptation of the parasite to the proportions of hemoglobin of the adult chicken may be responsible for the abnormal growth in the immature host.

  13. The generation of vertebral segmental patterning in the chick embryo.

    Science.gov (United States)

    Senthinathan, Biruntha; Sousa, Cátia; Tannahill, David; Keynes, Roger

    2012-06-01

    We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline.

  14. Expression of Fgf19 in the developing chick eye.

    Science.gov (United States)

    Francisco-Morcillo, Javier; Sánchez-Calderón, Hortensia; Kawakami, Yasuhiko; Izpisúa Belmonte, Juan Carlos; Hidalgo-Sánchez, Matías; Martín-Partido, Gervasio

    2005-04-21

    Fibroblast growth factor 19 (FGF19) is a new member of the FGF family of growth factors. Here, we describe the localization of Fgf19 mRNA in the developing chick retina and lens in stages from the Hamburger and Hamilton stage 15 (HH15) to postnatal day 30 (P30). Fgf19 was expressed in a transient manner in postmitotic neuroblasts during the migration from the ventricular surface to their final location. Moreover, from HH31 (embryonic day 7, E7) on, a subset of lined up Fgf19 expressing cells was distributed in the outer region of the presumptive INL. These cells were Pax6 immunoreactive horizontal cells. During the last third of embryogenesis, Fgf19 expression in the retina was progressively down-regulated and was not detected at P30. Also, it was transiently expressed in the equatorial region of the lens.

  15. An evaluation of the chick cardiomyocyte micromass system for identification of teratogens in a blind trial.

    Science.gov (United States)

    Hurst, Helen; Clothier, Richard H; Pratten, Margaret

    2009-12-01

    The chick micromass culture system has advantages over the validated rat system - ready availability and non-culling of the donor parent - but needs to give comparable results. This study confirmed comparability and the ability to extend the system to cover cardiac effects. It was also compared with the validated embryonic stem cell cardiomyocyte model. A teratogen and paired non-teratogen with known in vivo effects were used. Differential effects were measured via changes in cell protein content, cell viability (resazurin reduction and neutral red uptake), and cell contractility. Results showed that teratogens [L-ethionine, 5-fluorouracil and sulphisoxazole] could be distinguished from non-teratogens [DL-methionine, 6-methyluracil and sulphanilamide respectively]. Dichloroacetone and dichloropropanol affected embryonic stem cells but not the micromass; dichloropropanol had a greater effect than dichloroacetone. This approach revealed differential effects on contractility independent of effects on activity/viability, whilst the total cell protein remained unchanged. We suggest that pre-validation of this system should be examined.

  16. Aldose reductase mediates retinal microglia activation.

    Science.gov (United States)

    Chang, Kun-Che; Shieh, Biehuoy; Petrash, J Mark

    2016-04-29

    Retinal microglia (RMG) are one of the major immune cells in charge of surveillance of inflammatory responses in the eye. In the absence of an inflammatory stimulus, RMG reside predominately in the ganglion layer and inner or outer plexiform layers. However, under stress RMG become activated and migrate into the inner nuclear layer (INL) or outer nuclear layer (ONL). Activated RMG in cell culture secrete pro-inflammatory cytokines in a manner sensitive to downregulation by aldose reductase inhibitors. In this study, we utilized CX3CR1(GFP) mice carrying AR mutant alleles to evaluate the role of AR on RMG activation and migration in vivo. When tested on an AR(WT) background, IP injection of LPS induced RMG activation and migration into the INL and ONL. However, this phenomenon was largely prevented by AR inhibitors or in AR null mice, or was exacerbated in transgenic mice that over-express AR. LPS-induced increases in ocular levels of TNF-α and CX3CL-1 in WT mice were substantially lower in AR null mice or were reduced by AR inhibitor treatment. These studies demonstrate that AR expression in RMG may contribute to the proinflammatory phenotypes common to various eye diseases such as uveitis and diabetic retinopathy.

  17. Developmental morphology of the small intestine of African ostrich chicks.

    Science.gov (United States)

    Wang, J X; Peng, K M

    2008-12-01

    The objective of this study was to investigate the morphological development of the small intestine of African ostrich chicks and to examine the changes in the number of goblet cells therein by observing the gross anatomy and performing histochemistry and morphometry. The BW; length, height, and width of the villi; muscle thickness; depth of the crypts; and number of goblet cells in the intestinal villi and crypts were measured on neonatal d 1, 45, 90, and 334. Our results revealed that the weights of the duodenum, jejunum, and ileum (relative to the BW) peaked on d 90, 45, and 45, respectively, and tended to decline thereafter. The villus height and width and muscle thickness in the small intestine were positively correlated with the age of the birds. The ratio of the villus height to the crypt depth differed among the segments of the small intestine and at the different time points. The number of goblet cells in the intestinal villi and crypts increased rapidly up to postnatal d 45 and then decreased rapidly between d 45 and 90. The number of goblet cells in the villi was greatest in the jejunum on d 1 and in the ileum on d 45, whereas that in the crypt was greatest in the ileum on d 1 and 90 and in the duodenum on d 45. These results suggest that the small intestine develops gradually from postnatal d 1 to 90 and that the period up to postnatal d 45 is marked by significant developmental changes in the parameters reflective of the digestive capacity, such as the weight, length, and surface area of the intestine and the number of goblet cells. Therefore, in reared African ostrich chicks, feed management should be enhanced between postnatal d 1 and 45.

  18. Development of bioluminescent chick chorioallantoic membrane (CAM) models for primary pancreatic cancer cells: a platform for drug testing.

    Science.gov (United States)

    Rovithi, Maria; Avan, Amir; Funel, Niccola; Leon, Leticia G; Gomez, Valentina E; Wurdinger, Thomas; Griffioen, Arjan W; Verheul, Henk M W; Giovannetti, Elisa

    2017-03-17

    The aim of the present study was to develop chick-embryo chorioallantoic membrane (CAM) bioluminescent tumor models employing low passage cell cultures obtained from primary pancreatic ductal adenocarcinoma (PDAC) cells. Primary PDAC cells transduced with lentivirus expressing Firefly-luciferase (Fluc) were established and inoculated onto the CAM membrane, with >80% engraftment. Fluc signal reliably correlated with tumor growth. Tumor features were evaluated by immunohistochemistry and genetic analyses, including analysis of mutations and mRNA expression of PDAC pivotal genes, as well as microRNA (miRNA) profiling. These studies showed that CAM tumors had histopathological and genetic characteristic comparable to the original tumors. We subsequently tested the modulation of key miRNAs and the activity of gemcitabine and crizotinib on CAM tumors, showing that combination treatment resulted in 63% inhibition of tumor growth as compared to control (p testing, providing insights on molecular mechanisms underlying antitumor activity of new drugs/combinations.

  19. Detection of Marek's disease virus serotype 1 (MDV1) glycoprotein D in MDV1-infected chick embryo fibroblasts.

    Science.gov (United States)

    Ono, M; Jang, H K; Maeda, K; Kawaguchi, Y; Tohya, Y; Niikura, M; Mikami, T

    1996-08-01

    Chick embryo fibroblasts (CEFs) infected with three strains of Marek's disease virus serotype 1 (MDV1), GA, Md5 and JM, were subjected to indirect immunofluorescence assay with monoclonal antibodies (MAbs) against MDV1 homolog of glycoprotein D (MDV1 gD) of herpes simplex virus. By the MAbs, a number of MDV1 gD-positive cells were detected in CEFs infected with GA, whereas only a few and no positive cells were detected in CEFs infected with Md5 and JM, respectively. The MDV1 gD in GA-infected CEFs was recognized as the band of 64 kDa in immunoblot analysis using one of the MAbs. This is the first report that the MDV1 gD was detected in MDV1-infected cell cultures.

  20. Cell Therapy Applications for Retinal Vascular Diseases: Diabetic Retinopathy and Retinal Vein Occlusion.

    Science.gov (United States)

    Park, Susanna S

    2016-04-01

    Retinal vascular conditions, such as diabetic retinopathy and retinal vein occlusion, remain leading causes of vision loss. No therapy exists to restore vision loss resulting from retinal ischemia and associated retinal degeneration. Tissue regeneration is possible with cell therapy. The goal would be to restore or replace the damaged retinal vasculature and the retinal neurons that are damaged and/or degenerating from the hypoxic insult. Currently, various adult cell therapies have been explored as potential treatment. They include mesenchymal stem cells, vascular precursor cells (i.e., CD34+ cells, hematopoietic cells or endothelial progenitor cells), and adipose stromal cells. Preclinical studies show that all these cells have a paracrine trophic effect on damaged ischemic tissue, leading to tissue preservation. Endothelial progenitor cells and adipose stromal cells integrate into the damaged retinal vascular wall in preclinical models of diabetic retinopathy and ischemia-reperfusion injury. Mesenchymal stem cells do not integrate as readily but appear to have a primary paracrine trophic effect. Early phase clinical trials have been initiated and ongoing using mesenchymal stem cells or autologous bone marrow CD34+ cells injected intravitreally as potential therapy for diabetic retinopathy or retinal vein occlusion. Adipose stromal cells or pluripotent stem cells differentiated into endothelial colony-forming cells have been explored in preclinical studies and show promise as possible therapies for retinal vascular disorders. The relative safety or efficacy of these various cell therapies for treating retinal vascular disorders have yet to be determined.

  1. Demarcation laser photocoagulation induced retinal necrosis and rupture resulting in large retinal tear formation.

    Science.gov (United States)

    Quezada, Carlos; Pieramici, Dante J; Matsui, Rodrigo; Rabena, Melvin; Graue, Federico

    2015-06-01

    Retinal tears after laser photocoagulation are a rare complication that occurs after intense laser. It is talked about among retina specialist occurring particularly at the end of a surgical case while applying endophotocoagulation; to the best our knowledge, there are no reports in the literature of a large retinal tear induced after attempted in-office demarcation laser photocoagulation (DLP) that simulated a giant retinal tear. DLP has been employed in the management of selected cases of macula sparring rhegmatogenous retinal detachment (RRD). Even though extension of the retinal detachment through the "laser barrier" is considered a failure of treatment, few complications have been described with the use of this less invasive retinal detachment repair technique. We describe a case of a high myopic woman who initially was treated with demarcation laser photocoagulation for an asymptomatic retinal detachment associated with a single horseshoe tear and a full thickness large retinal tear was created where the laser was placed. Intense laser photocoagulation resulted in abrupt laser induced retinal necrosis and rupture creating this large retinal break. Proper laser technique should reduce the risks associated with this procedure.

  2. Presumed toxoplasmic central retinal artery occlusion and multifocal retinitis with perivascular sheathing

    Directory of Open Access Journals (Sweden)

    Arai H

    2014-04-01

    Full Text Available Haruka Arai,1 Tsutomu Sakai,1 Kiichiro Okano,1 Ranko Aoyagi,1 Ayano Imai,2 Hiroshi Takase,2 Manabu Mochizuki,2 Hiroshi Tsuneoka11Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; 2Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, Tokyo, JapanAbstract: Central retinal artery occlusion (CRAO and multifocal retinitis with perivascular sheathing are rare in ocular toxoplasmosis. We report a case of toxoplasmic CRAO and multifocal retinitis with perivascular sheathing. A healthy 83-year-old male developed left panuveitis. Funduscopic examination of the left eye showed a swollen optic disc and sheathing of the retinal artery with a dense vitreous haze and a white retinal lesion. Serum anti-toxoplasma antibodies were positive in a latex agglutination assay. Vitrectomy was performed to improve visualization of the retinal lesions and for examination of causative microorganisms. A postoperative fundus examination revealed CRAO with optic disc involvement and multifocal retinitis with perivascular sheathing. Qualitative multiplex polymerase chain reaction detected the Toxoplasma gondii B1 gene in ocular fluid from both the aqueous and vitreous humor. The presumed diagnosis of ocular toxoplasmosis was made and treatment was started with prednisone and acetylspiramycin with subsequent improvement. Two months later, the patient developed active retinochoroiditis in the left eye. After 6 weeks of anti-toxoplasma therapy, the disease involuted. Retinal vascular occlusions and multifocal retinitis with perivascular sheathing are rare in toxoplasmosis. This is the first case report of toxoplasmic CRAO and multifocal retinitis with perivascular sheathing. The diagnosis of ocular toxoplasmosis should be considered in patients with retinal artery occlusions and multifocal retinitis with perivascular sheathing associated with inflammation.Keywords: ocular toxoplasmosis, toxoplasma retinochoroiditis

  3. Investigating the role of retinal Müller cells with approaches in genetics and cell biology.

    Science.gov (United States)

    Fu, Suhua; Zhu, Meili; Ash, John D; Wang, Yunchang; Le, Yun-Zheng

    2014-01-01

    Müller cells are major macroglia and play many essential roles as a supporting cell in the retina. As Müller cells only constitute a small portion of retinal cells, investigating the role of Müller glia in retinal biology and diseases is particularly challenging. To overcome this problem, we first generated a Cre/lox-based conditional gene targeting system that permits the genetic manipulation and functional dissection of gene of interests in Müller cells. To investigate diabetes-induced alteration of Müller cells, we recently adopted methods to analyze Müller cells survival/death in vitro and in vivo. We also used normal and genetically altered primary cell cultures to reveal the mechanistic insights for Müller cells in biological and disease processes. In this article, we will discuss the applications and limitations of these methodologies, which may be useful for research in retinal Müller cell biology and pathophysiology.

  4. Human retinal pigment epithelial cell-induced apoptosis in activated T cells

    DEFF Research Database (Denmark)

    Jørgensen, A; Wiencke, A K; la Cour, M;

    1998-01-01

    PURPOSE: The immune privilege of the eye has been thought to be dependent on physical barriers and absence of lymphatic vessels. However, the immune privilege may also involve active immunologic processes, as recent studies have indicated. The purpose of the present study was to investigate whether...... human retinal pigment epithelial (RPE) cells can induce apoptosis in activated T cells. METHODS: Fas ligand (FasL) expression was detected by flow cytometry and immunohistochemistry. Cultured RPE cells were cocultured with T-cell lines and peripheral blood lymphocytes for 6 hours to 2 days. Induction...... of apoptosis was detected by 7-amino-actinomycin D and annexin V staining. RESULTS: Retinal pigment epithelial cells expressed FasL and induced apoptosis in activated Fas+ T cells. Blocking of Fas-FasL interaction with antibody strongly inhibited RPE-mediated T-cell apoptosis. Retinal pigment epithelial cells...

  5. Human retinal pigment epithelial cell-induced apoptosis in activated T cells

    DEFF Research Database (Denmark)

    Jørgensen, A; Wiencke, A K; la Cour, M

    1998-01-01

    human retinal pigment epithelial (RPE) cells can induce apoptosis in activated T cells. METHODS: Fas ligand (FasL) expression was detected by flow cytometry and immunohistochemistry. Cultured RPE cells were cocultured with T-cell lines and peripheral blood lymphocytes for 6 hours to 2 days. Induction...... of apoptosis was detected by 7-amino-actinomycin D and annexin V staining. RESULTS: Retinal pigment epithelial cells expressed FasL and induced apoptosis in activated Fas+ T cells. Blocking of Fas-FasL interaction with antibody strongly inhibited RPE-mediated T-cell apoptosis. Retinal pigment epithelial cells...... induced apoptosis in several activated T-cell populations and T-cell lines, including T-cell antigen receptor (TCR)-CD3-negative T-cell lines. In contrast, RPE cells induced little or no apoptosis in resting peripheral T cells. Major histocompatibility complex (MHC) class II monoclonal antibodies, which...

  6. The Study of Influencing Factors on the Growth Characters of Sprague—Dawley Rat Retinal Neurons in Vitro

    Institute of Scientific and Technical Information of China (English)

    LiuHQ; GeJ

    1999-01-01

    Purpose:To investigate the influencing factors in culturing Srague-Dawley(S-D) rats retinal neurons in order to lay foundation for further experimental research.Materials and Methods:Retinal cells were plated on plastic plates and coverslips coated with poly-lysine or ethylene imine polymer for primary culture.The cultured cells were divided into following groups:1.Culture medium changed every 2 tp 3 days vs changed only once;2.Cytosine arabinoside(Ara-C)added to the culture medium vs not added.The cells were observed and pictured under inverted phase contrast microscope.The cells were identified through immunocytochemistry.Results:The immunofluorescence showed that most of the cultured cells were neurons,among them were a few retinal ganglion cells.In the cultured group of which substrata coated with poly-l-lysine and culture medium added with Ara-c,the neurons intended to aggregate into clusters with relatively straight neurites.In the group of which substrata coated with ethylene imine polymer and medium added with Ara-c,the neurons grew dispersively with bent neurites.Both of them survived for 2 to 3 weeks.The cells which plated in the medium not added with Ara-c did not aggregate into clusters and survived longer than 4 weeks.In the group of which medium changed several times,the survival time of neurons was shorter than that in the medium changed only once.Conclusions:The retinal neurons plated on the substrata coated with ethylene imine polymer are easy to observe because of its dispersive growth.It is not favorable for the growth of the neurons by changing culture medium many times.Ara-c may possibly have side effect on the growth of retinal neurons.

  7. Bimatoprost protects retinal neuronal damage via Akt pathway.

    Science.gov (United States)

    Takano, Norihito; Tsuruma, Kazuhiro; Ohno, Yuta; Shimazawa, Masamitsu; Hara, Hideaki

    2013-02-28

    Worldwide, prostaglandin analogs, such as bimatoprost, have become the major therapeutic class for medical treatment of glaucoma because of their efficacy and generally well tolerated systemic safety profile. However, the detailed mechanism of the direct action of bimatoprost on retinal ganglion cells (RGC) has rarely been understood. Thus, in this study, we elucidated the mechanism of the protective effects of bimatoprost on RGC against oxidative stress. To examine the protective effects of bimatoprost, cultured RGC with various concentrations of bimatoprost (in both free acid and amide form) were exposed to l-buthionin-(S,R)-sulfoximine (BSO) plus glutamate or serum depletion in vitro and intravitreal injection of N-methyl-D-aspartate (NMDA) was used to induce retinal damage in vivo. To elucidate the protective mechanism of bimatoprost, we used western blot analysis to investigate the phosphorylation of Akt and extracellular signal-regulated kinase (ERK). Bimatoprost significantly reduced BSO plus glutamate- and serum deprivation-induced death in concentration-dependent manners. Bimatoprost induced activation of Akt and ERK, and a phosphatidylinositol 3-kinase inhibitor, LY294002, attenuated the protective effect of bimatoprost. On the other hand, a mitogen-activated protein kinase kinase inhibitor, U0126, exhibited protective effect unexpectedly. Moreover, ERK was more phosphorylated by attenuation of Akt activity in cultured RGC. In an in vivo study, bimatoprost reduced NMDA-induced RGC death. Taken together, these findings indicate that bimatoprost has protective effects on in vitro and in vivo retinal damage, suggesting that the mechanism underlying may be via the Akt pathway, which may modulate the ERK pathway.

  8. Effect of lactic acid bacteria probiotic culture treatment timing on Salmonella Enteritidis in neonatal broilers.

    Science.gov (United States)

    Higgins, J P; Higgins, S E; Wolfenden, A D; Henderson, S N; Torres-Rodriguez, A; Vicente, J L; Hargis, B M; Tellez, G

    2010-02-01

    In the present study, a series of experiments were conducted to evaluate the ability of a combination of 3 ATCC lactobacilli (LAB3) or a commercially available probiotic culture (PROB) to reduce Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) in broiler chicks. Additionally, we varied the timing of PROB administration in relationship to Salmonella challenge and determined the influence on recovery of enteric Salmonella. In experiments 1 to 3, chicks were randomly assigned to treatment groups and were then challenged via oral gavage with Salmonella Enteritidis. Chicks were treated 1 h after Salmonella Enteritidis challenge with LAB3 or PROB. Twenty-four hours posttreatment, cecal tonsils were collected for recovery of enteric Salmonella. In experiments 4 to 7, day-of-hatch chicks were randomly assigned to treatment groups and were then treated with PROB via oral gavage and placed into pens. Chicks were challenged with Salmonella Enteritidis 24 h after treatment via oral gavage. At 24 h after Salmonella Enteritidis challenge, cecal tonsils were collected and recovery of enteric Salmonella was determined. In experiments 8 to 10, 1-d-old chicks were randomly assigned to treatment groups and were then challenged via oral gavage with Salmonella Enteritidis and placed into pens. Chicks were treated 24 h after challenge with PROB via oral gavage. Twenty-four hours post PROB treatment, cecal tonsils were collected and enriched as described above. It was found that PROB significantly reduced cecal Salmonella Enteritidis recovery 24 h after treatment as compared with controls or LAB3-treated chicks in experiments 1 to 3 (PSalmonella Enteritidis challenge significantly reduced recovery of Salmonella Enteritidis in 2 out of 4 experiments and no reduction in cecal Salmonella Enteritidis was observed when chicks were challenged with Salmonella Enteritidis and treated 24 h later with PROB. These data demonstrate that PROB more effectively reduced Salmonella

  9. Draxin, an axon guidance protein, affects chick trunk neural crest migration.

    Science.gov (United States)

    Su, Yuhong; Naser, Iftekhar B; Islam, Shahidul M; Zhang, Sanbing; Ahmed, Giasuddin; Chen, Sandy; Shinmyo, Yohei; Kawakami, Minoru; Yamamura, Ken-ichi; Tanaka, Hideaki

    2009-12-01

    The neural crest is a multipotent population of migratory cells that arises in the central nervous system and subsequently migrates along defined stereotypic pathways. In the present work, we analyzed the role of a repulsive axon guidance protein, draxin, in the migration of neural crest cells. Draxin is expressed in the roof plate of the chick trunk spinal cord and around the early migration pathway of neural crest cells. Draxin modulates chick neural crest cell migration in vitro by reducing the polarization of these cells. When exposed to draxin, the velocity of migrating neural crest cells was reduced, and the cells changed direction so frequently that the net migration distance was also reduced. Overexpression of draxin also caused some early migrating neural crest cells to change direction to the dorsolateral pathway in the chick trunk region, presumably due to draxin's inhibitory activity. These results demonstrate that draxin, an axon guidance protein, can also affect trunk neural crest migration in the chick embryo.

  10. The effects of solcoseryl on the growth and multiplication of chick embryo fibroblasts cultivated "in vitro".

    Science.gov (United States)

    Brasseur, R; De Paermentier, F

    1979-01-01

    The action of Solcoseryl, a free protein extract of calf blood, was studied on chick embryo fibroblasts cultivated in vitro. Solcoseryl stimulates the permitotic DNA synthesis and increases the number of mitoses.,

  11. Fenugreek (Trigonella foenum-graecum L. effect on muscle growth of broiler chicks

    Directory of Open Access Journals (Sweden)

    Farman Ullah Khan,

    2011-01-01

    Full Text Available The purpose of this research work was to evaluate the aqueous seed extract of Trigonella foenum-graecum L. (Fenugreek on the weight of breast, thigh and leg of broiler chicks. One hundred and sixty, day old male broiler chicks were randomly assigned to four treatments i.e., A, B, C and D. Each treatment was replicated four times with 10 chicks per replicate. Groups B, C and D received the aqueous extract of fenugreek @ 10, 20 and 30 ml/L, respectively while group A served as a control. Chicks were reared in cages in an open sided house. The data showed that weight of breast, thigh and leg were significantly (P<0.05 heavier in group C compared to control. It was concluded from this study that Trigonella foenum-graecum at the rate of 30 ml/L aqueous extract has a beneficial impact on the growth of these muscle tissues.

  12. Effects on chicks of Balanites aegyptiaca kernel saponin given by different routes of administration.

    Science.gov (United States)

    Nakhla, H B; Mohammed, O S; Abu al Futuh, I M; Adam, S E

    1992-06-01

    The effect of oral or parenteral administration of crude saponin extract from Balanites aegyptiaca seed kernal on Hisex-type chicks was studied. Seven-d-old chicks were given 5 mg Balanites crude saponin/kg/d im, 25 mg/kg/d ip or 250 mg/kg/day po for 3 w. When compared to controls, the body weights of dosed chicks were depressed and serum LDH and GOT activities and uric acid concentrations were significantly elevated. There were no consistent differences in serum GGT, CPK, total cholesterol and total protein between control and dosed birds. The main lesions were fatty cytoplasmic vacuolation and necrosis of hepatocytes, lymphocytic nodules, epithelial cell degeneration of the renal tubules, catarrhal enteritis and varying degrees of hemorrhage in the thigh and breast muscles. Myositis or peritonitis were observed in chicks given Balanites crude saponins im or ip, respectively.

  13. A detailed description of an economical setup for electroporation of chick embryos in ovo.

    Science.gov (United States)

    Borges, R M; Horne, J H; Melo, A; Vidal, J T; Vieceli, F M; Melo, M O; Kanno, T Y N; Fraser, S E; Yan, C Y I

    2013-09-01

    One of the challenges of the postgenomic era is characterizing the function and regulation of specific genes. For various reasons, the early chick embryo can easily be adopted as an in vivo assay of gene function and regulation. The embryos are robust, accessible, easily manipulated, and maintained in the laboratory. Genomic resources centered on vertebrate organisms increase daily. As a consequence of optimization of gene transfer protocols by electroporation, the chick embryo will probably become increasingly popular for reverse genetic analysis. The challenge of establishing chick embryonic electroporation might seem insurmountable to those who are unfamiliar with experimental embryological methods. To minimize the cost, time, and effort required to establish a chick electroporation assay method, we describe and illustrate in great detail the procedures involved in building a low-cost electroporation setup and the basic steps of electroporation.

  14. Behavioral observations and operant procedures using microwaves as a heat source for young chicks

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, W.D.; McMillan, I.; Bate, L.A.; Otten, L.; Pei, D.C.

    1986-08-01

    Four trials, using operant conditioning procedures, were conducted to study the response of chicks, housed at 16 C, to microwave or infrared heat. Microwave power density was 26 mW/cm2 in Trial 1, 13 mW/cm2 in Trial 2, and 10 mW/cm2 in Trials 3 and 4. Chicks voluntarily demanded between 28 and 63% as much heat (min heat/hr) from microwave source as from infrared source at all power densities. There was no correlation, however, between the ratio of heat demanded and the power density used. There were no significant differences in growth between infrared- or microwave-heated chicks. It is evident from these studies that 8-day-old broiler chicks are capable of associating the performance of a task with a thermal reward provided by the microwaves. They are also able to utilize these microwaves through operant conditioning without any visible detrimental effect to their health or behavior.

  15. Efficacy of adsorbents (bentonite and diatomaceous earth) and turmeric (Curcuma longa) in alleviating the toxic effects of aflatoxin in chicks.

    Science.gov (United States)

    Dos Anjos, F R; Ledoux, D R; Rottinghaus, G E; Chimonyo, M

    2015-01-01

    A study was conducted to determine the efficacy of bentonite clay (BC), diatomaceous earth (DE) and turmeric powder (TUM) in alleviating the toxic effects of aflatoxin B1 (AFB1). A total of 250 Ross-308 d-old male broiler chicks were assigned to 10 dietary treatments (5 replicates of 5 chicks) from hatch to d 21. Dietary treatments were: basal diet; basal diet plus AFB1 (2 mg) or BC (0.75%), or DE (0.75%), or TUM (200 mg/kg curcuminoids) and different combinations of AFB1, BC, DE and TUM. Feed intake (FI), body weight gain (BWG) and feed gain (FG) of the birds fed on BC or DE separately were not different from control birds. Birds fed on TUM only had similar FI and FG but lower BWG than control chicks. Aflatoxin B1 reduced FI, BWG and serum concentrations of glucose, albumin, total protein calcium, but increased FG and relative liver and kidney weights. Chicks fed on the combination of AFB1 and BC had similar FI and FG to control chicks. Chicks fed on the combination of DE and AFB1 had lower FI (23.1%) and BWG (28.6%) compared with control chicks. Chicks fed on the combination of TUM and AFB1 also had decreased FI (26.2 %) and BWG (31%) compared with control chicks. Chicks fed on the combination of AFB1, BC and TUM consumed significantly higher amounts of feed compared with chicks fed on only AF, but gained less when compared with control diet chicks. Chicks fed on the combination of AFB1, DE and TUM diet had poorer growth performance than those fed on AFB1 alone. None of the combination diets reduced the severity of liver lesions.

  16. All "chick-a-dee" calls are not created equally. Part I. Open-ended categorization of chick-a-dee calls by sympatric and allopatric chickadees.

    Science.gov (United States)

    Bloomfield, Laurie L; Sturdy, Christopher B

    2008-01-01

    Researchers trained 24 black-capped (Poecile atricapillus) and 12 mountain (P. gambeli) chickadees in an operant conditioning task to determine if they use open-ended categorization to classify "chick-a-dee" calls, and whether black-capped chickadees that had experience with mountain chick-a-dee calls (sympatric group) would perform this task differently than inexperienced black-capped chickadees (allopatric group). All experimental birds learned to discriminate between species' call categories faster than within a category (Experiment 1), and subsequently classified novel and original between-category chick-a-dee calls in Experiments 2 and 3 following a change in the category contingency. These results suggest that regardless of previous experience, black-capped and mountain chickadees classify their own and the other species' calls into two distinct, yet open-ended, species-level categories.

  17. Optical coherence tomography angiography in retinal diseases

    Directory of Open Access Journals (Sweden)

    K V Chalam

    2016-01-01

    Full Text Available Optical coherence tomography angiography (OCTA is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA algorithm (a vital component of OCTA software helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD, retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA. Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases.

  18. Genomic analysis of mouse retinal development.

    Directory of Open Access Journals (Sweden)

    Seth Blackshaw

    2004-09-01

    Full Text Available The vertebrate retina is comprised of seven major cell types that are generated in overlapping but well-defined intervals. To identify genes that might regulate retinal development, gene expression in the developing retina was profiled at multiple time points using serial analysis of gene expression (SAGE. The expression patterns of 1,051 genes that showed developmentally dynamic expression by SAGE were investigated using in situ hybridization. A molecular atlas of gene expression in the developing and mature retina was thereby constructed, along with a taxonomic classification of developmental gene expression patterns. Genes were identified that label both temporal and spatial subsets of mitotic progenitor cells. For each developing and mature major retinal cell type, genes selectively expressed in that cell type were identified. The gene expression profiles of retinal Müller glia and mitotic progenitor cells were found to be highly similar, suggesting that Müller glia might serve to produce multiple retinal cell types under the right conditions. In addition, multiple transcripts that were evolutionarily conserved that did not appear to encode open reading frames of more than 100 amino acids in length ("noncoding RNAs" were found to be dynamically and specifically expressed in developing and mature retinal cell types. Finally, many photoreceptor-enriched genes that mapped to chromosomal intervals containing retinal disease genes were identified. These data serve as a starting point for functional investigations of the roles of these genes in retinal development and physiology.

  19. Optical Coherence Tomography Angiography in Retinal Diseases.

    Science.gov (United States)

    Chalam, K V; Sambhav, Kumar

    2016-01-01

    Optical coherence tomography angiography (OCTA) is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA) algorithm (a vital component of OCTA software) helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD), retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV) in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA). Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases.

  20. Bilateral acute retinal necrosis after herpetic meningitis

    Directory of Open Access Journals (Sweden)

    Katsura T

    2012-04-01

    Full Text Available Keisho Hirota1,2, Masayuki Akimoto1,3, Toshiaki Katsura21Department of Ophthalmology, Kyoto Medical Center, National Hospital Organization, 2Internal Medicine, Kyoto Medical Center, 3Clinical Research Center, Kyoto Medical Center, Kyoto, JapanPurpose: The report of a case of bilateral acute retinal necrosis after herpetic meningitis.Case report: A 47-year-old man was admitted with the chief complaint of persistent high fever and transient loss of consciousness. Although his general condition improved after intravenous acyclovir administration, the patient presented with visual loss in both eyes 4 days after admission. Visual acuity in his right eye was 20/200 and his left eye had light perception alone. Both eyes showed panretinal arteritis diagnosed as acute retinal necrosis. Panretinal photocoagulation was performed for both eyes. Progression of retinal detachment was prevented in both eyes; however, visual acuity of the left eye was totally lost because of neovascular glaucoma. Visual acuity of the right eye recovered to 20/20.Conclusion: Although cases of bilateral acute retinal necrosis have been reported after herpetic encephalitis, this condition is rare after herpetic meningitis. Prophylactic acyclovir therapy and early panretinal photocoagulation may prevent retinal detachment and improve the prognosis. Neurologists and ophthalmologists should be aware that not only herpetic encephalitis but also herpetic meningitis can lead to acute retinal necrosis within a very short interval.Keywords: acute retinal necrosis, herpetic meningitis, herpes simplex, varicella zoster virus

  1. Fundus changes in central retinal vein occlusion.

    Science.gov (United States)

    Hayreh, Sohan Singh; Zimmerman, M Bridget

    2015-01-01

    To investigate systematically the retinal and optic disk changes in central retinal vein occlusion (CRVO) and their natural history. This study comprised 562 consecutive patients with CRVO (492 nonischemic [NI-CRVO] and 89 ischemic CRVO [I-CRVO] eyes) seen within 3 months of onset. Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations and fluorescein fundus angiography. Retinal and subinternal limiting membrane hemorrhages and optic disk edema in I-CRVO were initially more marked (P retinal epithelial pigment degeneration, serous macular detachment, and retinal perivenous sheathing developed at a higher rate in I-CRVO than that in NI-CRVO (P retinal venous engorgement than NI-CRVO (P = 0.003). Fluorescein fundus angiography showed significantly more fluorescein leakage, retinal capillary dilatation, capillary obliteration, and broken capillary foveal arcade (P < 0.0001) in I-CRVO than NI-CRVO. Resolution time of CRVO was longer for I-CRVO than NI-CRVO (P < 0.0001). Characteristics and natural history of fundus findings in the two types of CRVO are different.

  2. The importance of endogenous nutrition of chicks from divergent strains for growing tested by deutectomy

    Directory of Open Access Journals (Sweden)

    E Gonzales

    2008-09-01

    Full Text Available Effects of yolk sac removal (deutectomy upon performance of chicks from three divergent strains were tested to evaluate the importance of endogenous nutrition on the post-hatch phase. Chicks from three different strains (Hy-Line W98, Cobb 500, and JA57 were submitted to a surgery procedure after hatching. Half of them had the residual yolk removed, and the other constituted a sham-deutectomized group. After operation, chicks were designated to a 3 x 2 factorial design (3 strains x 2 presence/absence of yolk sac, in a total of six experimental groups and ten replications of two to four birds. During 14 experimental days all birds were fed ad libitum a 21% CP and 3050 kcal/kg EM mash diet. Data were analyzed by ANOVA, and Tukey's test (p<0.05. Relative yolk sac weights were similar among chicks from different breeders, averaging 11.7% to 13.5%. Comparing to sham-operated, deuctetomized chicks had lower weight gain at 7 and 14d, indicating that endogenous nutrition, via yolk sac, is very important to galliform birds whatever their strain. Hy-line deutectomized chicks gained 40% less body weight at the 7th day as compared to their sham counterparts. Analysis of the same criterion to Cobb and JA57 groups revealed a decrease of 16.1% and 10.8%, respectively, on weight gain efficiency. At the 14th rearing day, Hy-Line chicks had the lowest weight gain, followed by JA57s' and Cobbs'. The results suggested that chicks selected for fast growth are less dependent on endogenous nutrition, responding better when exogenous nutrition is associated to yolk assimilation.

  3. Response of brown hisex chicks to low levels of Jatropha curcas, Ricinus communis or their mixture.

    Science.gov (United States)

    el Badwi, S M; Mousa, H M; Adam, S E; Hapke, H J

    1992-08-01

    Feeding Jatropha curcas seed at 0.5% of the basic diet for 2 w was not lethal to chicks. In chicks fed 0.5% Ricinus communis seed or a mixture of 0.5% J curcas + 0.5% R communis for 2 w, there was dullness, poor growth, locomotor disturbance and death. Pathological changes were correlated with alterations in clinical chemistry and hematology.

  4. Comparative toxicity of Ricinus communis and Jatropha curcas in Brown Hisex chicks.

    Science.gov (United States)

    el Badwi, S M; Adam, S E; Hapke, H J

    1995-02-01

    Symptoms, lesions and changes in growth, haematology and clinical chemistry were investigated in Brown Hisex chicks fed diets containing 0.5% Jatropha curcas seed or 0.5% Ricinus communis seed. High mortality and more severe changes occurred in chicks on Ricinus diet than Jatropha feed. The results indicated that caution should be observed in tropical countries where people are accustomed to chewing castor bean when in need of a laxative.

  5. Productivity and Composition of Fatty Acids in Chicks fed with Azadirachta indica A. Juss

    OpenAIRE

    Imna Trigueros V; Miguel Ramón C; José Vázquez O; Juan Aguirre M; Carlos Garcia C; Jaime Martínez T

    2015-01-01

    ABSTRACTObjective. Evaluate the productivity and composition of fatty acids in chicks fed diets enriched with neem Azadirachta indica A. Juss seed flour. Materials and methods. 80 mixed broiler chicks of Arbor Acres stock and levels 0, 1, 3 and 5% neem seed flour added to a commercial diet were evaluated. 20 experimental units were included in each treatment for five weeks. The consumption and weight gain were recorded, as well as the composition of fatty acids in the fat by means of alkaline...

  6. Timing of fledging is influenced by glucocorticoid physiology in Laysan Albatross chicks.

    Science.gov (United States)

    Sprague, R S; Breuner, C W

    2010-07-01

    Fledging is a major life transition for birds, when juveniles move from the safety of a nest into an environment where they must find food and avoid predators. The timing of fledging within a season can have significant effects on future survival and breeding success. Proximate triggers of fledging are unknown: though wing development is likely a primary factor, other physiological changes, such as elevated plasma corticosterone (CORT), may affect fledging behavior. Laysan Albatross (Phoebastria immutabilis) chicks have an extended post-hatching period during which they reach 150% of adult mass. However, approaching fledging, chicks fast for days to weeks and lose mass while still putting energy into feather growth. We evaluated chick morphology and physiology to elucidate proximate triggers of fledging. As in some other species, CORT increased as chicks fasted and lost body mass. At the same time, corticosteroid binding globulin (CBG) declined, thus amplifying free CORT prior to fledging. Once chicks reached a morphological threshold, free CORT levels predicted how long they stayed at the colony: chicks with higher free CORT fledged sooner. To perturb the relationship between body condition, endocrine physiology, and fledging behavior, we supplementally fed chicks for the month before fledging. Fed birds had a slower decrease in body mass, slower decrease in CBG, slower increase in free CORT, and stayed at the colony longer after reaching a morphological threshold. Our study suggests that as chicks lose mass, free CORT acts as a signal of energetic or nutritional state to adjust the timing of fledging. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Effect of dietary glutamine supplementation on Salmonella colonization in the ceca of young broiler chicks.

    Science.gov (United States)

    Fasina, Y O; Bowers, J B; Hess, J B; McKee, S R

    2010-05-01

    Live poultry is an important vehicle for transmitting Salmonella Typhimurium to humans that have salmonellosis. It is therefore imperative to reduce Salmonella Typhimurium levels in the gastrointestinal tract of live chickens. Glutamine is an established immunonutrient that is capable of alleviating disease conditions in humans and rats. Thus, 2 experiments that used Ross broiler chicks were conducted to evaluate the effect of glutamine supplementation at 1% level of the diet on cecal Salmonella Typhimurium levels in young broiler chicks. Experiment 1 consisted of i) treatment 1 (control, CN), in which chicks were given an unmedicated corn-soybean meal basal starter diet without glutamine supplementation or Salmonella Typhimurium challenge; ii) treatment 2 (CST), in which chicks were given the same diet as CN but challenged with 3.6 x 10(6) cfu Salmonella Typhimurium/mL at 3 d of age; and iii) treatment 3 (GST), in which chicks were given the unmedicated corn-soybean meal basal starter diet supplemented with glutamine at 1% level, and challenged with 3.6 x 10(6) cfu at 3 d of age. Experiment 2 used similar treatments (CN, CST, and GST), except that chicks in CST and GST were challenged with 7.4 x 10(7) cfu Salmonella Typhimurium/mL, and a fourth treatment was added. The fourth treatment consisted of chicks that were not challenged with Salmonella Typhimurium but given the same diet as in GST. Duration of each experiment was 14 d. Growth performance of chicks was monitored weekly, and cecal Salmonella Typhimurium concentration was microbiologically enumerated on d 4, 10, or 11 postchallenge. Results showed that glutamine supplementation improved BW and BW gain in experiment 2 (P 0.05). The optimum supplemental level of glutamine that will enhance intestinal resistance to Salmonella Typhimurium colonization should be determined.

  8. Automatic diagnosis of retinal diseases from color retinal images

    CERN Document Server

    Jayanthi, D; SwarnaParvathi, S

    2010-01-01

    Teleophthalmology holds a great potential to improve the quality, access, and affordability in health care. For patients, it can reduce the need for travel and provide the access to a superspecialist. Ophthalmology lends itself easily to telemedicine as it is a largely image based diagnosis. The main goal of the proposed system is to diagnose the type of disease in the retina and to automatically detect and segment retinal diseases without human supervision or interaction. The proposed system will diagnose the disease present in the retina using a neural network based classifier.The extent of the disease spread in the retina can be identified by extracting the textural features of the retina. This system will diagnose the following type of diseases: Diabetic Retinopathy and Drusen.

  9. Acoustic imprinting leads to differential 2-deoxy-D-glucose uptake in the chick forebrain.

    Science.gov (United States)

    Maier, V; Scheich, H

    1983-01-01

    This report describes experiments in which successful acoustic imprinting correlates with differential uptake of D-2-deoxy[14C]glucose in particular forebrain areas that are not considered primarily auditory. Newly hatched guinea chicks (Numida meleagris meleagris) were imprinted by playing 1.8-kHz or 2.5-kHz tone bursts for prolonged periods. Those chicks were considered to be imprinted who approached the imprinting stimulus (emitted from a loudspeaker) and preferred it over a new stimulus in a simultaneous discrimination test. In the 2-deoxy-D-glucose experiment all chicks, imprinted and naive, were exposed to 1.8-kHz tone bursts for 1 hr. As shown by the autoradiographic analysis of the brains, neurons in the 1.8-kHz isofrequency plane of the auditory "cortex" (field L) were activated in all chicks, whether imprinted or not. However, in the most rostral forebrain striking differences were found. Imprinted chicks showed an increased 2-deoxy-D-glucose uptake in three areas, as compared to naive chicks: (i) the lateral neostriatum and hyperstriatum ventrale, (ii) a medial magnocellular field (medial neostriatum/hyperstriatum ventrale), and (iii) the most dorsal layers of the hyperstriatum. Based on these findings we conclude that these areas are involved in the processing of auditory stimuli once they have become meaningful by experience. Images PMID:6574519

  10. Yolk hormones influence in ovo chemosensory learning, growth, and feeding behavior in domestic chicks.

    Science.gov (United States)

    Bertin, Aline; Meurisse, Maryse; Arnould, Cécile; Leterrier, Christine; Constantin, Paul; Cornilleau, Fabien; Vaudin, Pascal; Burlot, Thierry; Delaveau, Joel; Rat, Christophe; Calandreau, Ludovic

    2016-03-01

    In this study, we assessed whether prenatal exposure to elevated yolk steroid hormones can influence in ovo chemosensory learning and the behavior of domestic chicks. We simulated a maternal environmental challenge by experimentally enhancing yolk progesterone, testosterone, and estradiol concentrations in hen eggs prior to incubation. The embryos from these hormones-treated eggs (HO) as well as sham embryos (O) that had received the vehicle-only were exposed to the odor of fish oil (menhaden) between embryonic Days 11 and 20. An additional group of control embryos (C) was not exposed to the odor. All chicks were tested following hatching for their feeding preferences between foods that were or were not odorized with the menhaden odor. In the 3-min choice tests, the behavior of O chicks differed significantly according to the type of food whereas C and HO chicks showed no preference between odorized and non-odorized food. Our result suggests weaker response in HO chicks. In addition, HO chicks showed impaired growth and reduced intake of an unfamiliar food on the 24-h time scale compared to controls. Our data suggest that embryonic exposure to increased yolk hormone levels can alter growth, chemosensory learning, and the development of feeding behaviors.

  11. Metabolic response to lipid infusion in fasting winter-acclimatized king penguin chicks (Aptenodytes patagonicus).

    Science.gov (United States)

    Teulier, Loïc; Tornos, Jérémy; Rouanet, Jean-Louis; Rey, Benjamin; Roussel, Damien

    2013-05-01

    During the cold austral winter, king penguin chicks are infrequently fed by their parents and thus experience severe nutritional deprivation under harsh environmental conditions. These energetic constraints lead to a range of energy sparing mechanisms balanced by the maintenance of efficient thermogenic processes. The present work investigated whether the high thermogenic capacities exhibited by winter-acclimatized king penguin chicks could be related to an increase in lipid substrate supply and oxidation in skeletal muscle, the main site of thermogenesis in birds. To test this hypothesis, we examined i) the effect of an experimental rise in plasma triglyceride on the whole metabolic rate in winter-acclimatized (WA) and de-acclimatized king penguin chicks kept at thermoneutrality (TN), and ii) investigated the fuel preference of muscle mitochondria. In vivo, a perfusion of a lipid emulsion induced a small 10% increase of metabolic rate in WA chicks but not in TN group. In vitro, the oxidation rate of muscle mitochondria respiring on lipid-derived substrate was +40% higher in WA chicks than in TN, while no differences were found between groups when mitochondria oxidized carbohydrate-derived substrate or succinate. Despite an enhanced fuel selection towards lipid oxidation in skeletal muscle, a rise of circulating lipids per se was not sufficient to fully unravel the thermogenic capacity of winter-acclimatized king penguin chicks.

  12. Egg traits and physiological neonatal chick parameters from broiler breeder at different ages

    Directory of Open Access Journals (Sweden)

    BC Luquetti

    2004-03-01

    Full Text Available This investigation was carried out to study egg traits (weight, specific gravity and eggshell thickness, and neonatal chick parameters (weight, blood, cardiac and lung parameters from breeder at different ages. After hatching, neonatal chicks, male and female, from broiler breeder at three different ages (30, 45 and 60 weeks were sacrificed and blood (red blood cell number, hematocrit, mean cell volume, blood viscosity, and haemoglobin, cardiac (right ventricle and total ventricle weights, cardiac index and lung (mean pulmonary pressure, fresh relative lung weight parameters were measured. No significant differences in eggshell thickness or specific gravity were observed in eggs from the three different breeder age. The incubated eggs and neonatal chicks showed heavier absolute weights with increasing breeder age. Broiler breeder age did not affect blood parameters or cardiac index, but affected right ventricle and total ventricle absolute weights. Red blood cell number and hematocrit were higher and lung weight and lung weight:chick weight index were lower for female neonatal chicks. The findings of this study revealed that breeder age affects neonatal chick parameters such as body weight, heart and lung absolute weights, but not blood parameters.

  13. Roller coaster-associated retinal detachments.

    Science.gov (United States)

    Shaikh, Saad

    2011-01-01

    The purpose of this study was to report two cases of rhegmatogenous retinal detachment noted immediately after roller coaster riding in an at-risk population. In separate incidents, a 35-year-old woman and a 45-year-old woman, both significantly myopic, presented with visual symptoms after riding roller coasters. Both patients were found to have acute rhegmatogenous retinal detachments associated with myopic degenerative changes. The pathology supported an acute, traumatic etiology for the detachments. Roller coaster riding should be considered an adjunct risk factor for retinal detachment in predisposed patients.

  14. Photostress Testing Device for Diagnosing Retinal Disease

    Directory of Open Access Journals (Sweden)

    Elizabeth Swan

    2014-08-01

    Full Text Available Retinal diseases such as Age-Related Macular Degeneration (ARMD affect nearly one in three elderly patients. ARMD damages the central vision photoreceptors in the fovea. The Photostress Test is a simple technique for testing for the early effects of ARMD. Here, the illumination sources in a novel self-administered Photostress Testing device were modeled for safety and distribution in illumination software. After satisfying the design constraints in the model, a prototype of the illumination system was fabricated and tested to confirm the modeling results. The resultant prototype can be used to aid in the diagnosis of retinal disease and is well within retinal safety levels.

  15. Fluid vitreous substitutes in vitreo retinal surgery.

    Science.gov (United States)

    Saxena, S; Gopal, L

    1996-12-01

    Advances in the surgical instrumentation and vitreoretinal techniques have allowed intraoperative reapproximation of retina to a more normal position. The use of intravitreally injected liquid materials (viscoelastic liquids, liquid perfluorocarbons and silicone oil), as adjunctive agents to vitreo-retinal surgery play an important role in facilitating retinal reattachment. These materials are used as intraoperative instruments to re-establish intraocular volume, assist in separating membranes adherent to the retina, manipulate retinal detachments and mechanically flatten detached retina. Over the longer term, silicone oil maintains intraocular tamponade. One should be cognizant of the potential uses, benefits and risks of each of these vitreous substitutes.

  16. Fluid vitreous substitutes in vitreo retinal surgery

    Directory of Open Access Journals (Sweden)

    Saxena Sandeep

    1996-01-01

    Full Text Available Advances in the surgical instrumentation and vitreoretinal techniques have allowed intraoperative reapproximation of retina to a more normal position. The use of intravitreally injected liquid materials (viscoelastic liquids, liquid perfluorocarbons and silicone oil, as adjunctive agents to vitreo-retinal surgery play an important role in facilitating retinal reattachment. These materials are used as intraoperative instruments to re-establish intraocular volume, assist in separating membranes adherent to the retina, manipulate retinal detachments and mechanically flatten detached retina. Over the longer term, silicone oil maintains intraocular tamponade. One should be cognizant of the potential uses, benefits and risks of each of these vitreous substitutes.

  17. [New drug therapy for retinal degeneration].

    Science.gov (United States)

    Ohguro, Hiroshi

    2008-01-01

    Retinitis pigmentosa (RP) is an inherited retinal degeneration characterized by nyctalopia, ring scotoma, and bone-spicule pigmentation of the retina. So far, no effective therapy has been found for RP. As a possible molecular etiology of RP, retina-specific gene deficits are most likely involved, but little has been identified in terms of intracellular mechanisms leading to retinal photoreceptor cell death at post-translational levels. In order to find an effective therapy for RP, we must look for underlying common mechanisms that are responsible for the development of RP, instead of designing a specific therapy for each of the RP types with different causes. Therefore, in the present study, several animal models with different causes of RP were studied, including (1)Royal College of Surgeons (RCS) rats with a deficit of retinal pigment epithelium (RPE) function caused by rhodopsin mutation; (2) P23H rats, (3) S334ter rats, (4) photo stress rats, (5) retinal degeneration (rd) mice with a deficit of phosphodiesterase(PDE) function; and (6) cancer-associated retinopathy (CAR) model rats with a deficit of recoverin-dependent photoreceptor adaptation function. In each of these models, the following assessments were made in order to elucidate common pathological mechanisms among the models: (1) retinal function assessed by electroretinogram (ERG), (2) retinal morphology, (3) retinoid analysis, (4) rhodopsin regeneration, (5) rhodopsin phosphorylation and dephosphorylation, and (6) cytosolic cGMP levels. We found that unregulated photoreceptor adaptation processes caused by an imbalance of rhodopsin phosphorylation and dephosphorylation caused retinal dysfunction leading to photoreceptor cell death. As possible candidate drugs for normalizing these retinal dysfunctions and stopping further retinal degeneration, nilvadipine, a Ca channel blocker, retinoid derivatives, and anthocyanine were chosen and tested to determine their effect on the above animal models with

  18. Interferon-gamma and tumour necrosis factor induce expression of major histocompatibility complex antigen on rat retinal astrocytes.

    OpenAIRE

    el-Asrar, A M; Maimone, D.; Morse, P H; Lascola, C; Reder, A T

    1991-01-01

    Cultured rat retinal astrocytes were tested by indirect immunofluorescence staining for their ability to express class I and II major histocompatibility complex (MHC) antigens under basal culture conditions and after three days of stimulation with two recombinant cytokines, rat interferon-gamma (IFN-gamma) and human tumour necrosis factor alpha (TNF alpha). Under basal culture conditions low levels of class I antigens were detected on a small percentage of cells, but there was no visible clas...

  19. The cost-effectiveness of the Argus II retinal prosthesis in Retinitis Pigmentosa patients

    OpenAIRE

    2014-01-01

    Background Retinitis Pigmentosa (RP) is a hereditary genetic disease causing bilateral retinal degeneration. RP is a leading cause of blindness resulting in incurable visual impairment and drastic reduction in the Quality of life of the patients. Second Sight Medical Products Inc. developed Argus II, a retinal prosthesis system for treating RP. Argus II is the world’s first ever-commercial implant intended to restore some vision in the blind patients. The objective of this study was to assess...

  20. Long-term outcomes in patients undergoing vitrectomy for retinal detachment due to viral retinitis

    Directory of Open Access Journals (Sweden)

    Almeida DRP

    2015-07-01

    Full Text Available David RP Almeida,1 Eric K Chin,1 Ryan M Tarantola,1 Elizabeth O Tegins,1 Christopher A Lopez,1 Herbert Culver Boldt,1 Karen M Gehrs,1 Elliott H Sohn,1 Stephen R Russell,1 James C Folk,1 Vinit B Mahajan1,2 1Department of Ophthalmology and Visual Sciences, 2Omics Laboratory, University of Iowa Hospitals and Clinics, Iowa City, IA, USA Purpose: To determine the outcomes in patients with rhegmatogenous retinal detachment (RRD secondary to viral retinitis. Patients and methods: This was a retrospective, consecutive, noncomparative, interventional case series of 12 eyes in ten patients with RRD secondary to viral retinitis. Results of vitreous or aqueous biopsy, effect of antiviral therapeutics, time to retinal detachment, course of visual acuity, and anatomic and surgical outcomes were investigated. Results: There were 1,259 cases of RRD during the study period, with 12 cases of RRD secondary to viral retinitis (prevalence of 0.95%. Follow-up was available for a mean period of 4.4 years. Varicella zoster virus was detected in six eyes, herpes simplex virus in two eyes, and cytomegalovirus in two eyes. Eight patients were treated with oral valacyclovir and two patients with intravenous acyclovir. Lack of optic nerve involvement correlated with improved final visual acuity of 20/100 or greater. Pars plana vitrectomy (n=12, silicone-oil tamponade (n=11, and scleral buckling (n=10 provided successful anatomic retinal reattachment in all cases, with no recurrent retinal detachment and no cases of hypotony during the follow-up period. Conclusion: Varicella zoster virus was the most frequent cause of viral retinitis, and lack of optic nerve involvement was predictive of a favorable visual acuity prognosis. Vitrectomy with silicone-oil tamponade and scleral buckle placement provided stable anatomical outcomes. Keywords: viral retinitis, acute retinal necrosis, herpetic retinitis, vitrectomy, retinal detachment 

  1. Concurrent central retinal artery occlusion and branch retinal vein occlusion in giant cell arteritis

    OpenAIRE

    Chu, Edward R.; Chen, Celia S

    2010-01-01

    Edward R Chu, Celia S ChenDepartment of Ophthalmology, Flinders Medical Centre and Flinders University, Bedford Park, SA, AustraliaAbstract: Ophthalmic involvement in giant cell arteritis can manifest in a number of ways. Central retinal artery occlusion is one of the common causes of visual loss in giant cell arteritis. On the contrary, branch retinal vein occlusion is rarely associated with the latter. We report an 89-year-old lady with acute left central retinal artery occlusion on a backg...

  2. New medium used in the differentiation of human pluripotent stem cells to retinal cells is comparable to fetal human eye tissue.

    Science.gov (United States)

    Wang, Xiaobing; Xiong, Kai; Lin, Cong; Lv, Lei; Chen, Jing; Xu, Chongchong; Wang, Songtao; Gu, Dandan; Zheng, Hua; Yu, Hurong; Li, Yan; Xiao, Honglei; Zhou, Guomin

    2015-06-01

    Human pluripotent stem cells (hPSCs) have the potential to differentiate along the retinal lineage. However, most induction systems are dependent on multiple small molecular compounds such as Dkk-1, Lefty-A, and retinoic acid. In the present study, we efficiently differentiated hPSCs into retinal cells using a retinal differentiation medium (RDM) without the use of small molecular compounds. This novel differentiation system recapitulates retinal morphogenesis in humans, i.e. hPSCs gradually differentiate into optic vesicle-shaped spheres, followed by optic cup-shaped spheres and, lastly, retinal progenitor cells. Furthermore, at different stages, hPSC-derived retinal cells mirror the transcription factor expression profiles seen in their counterparts during human embryogenesis. Most importantly, hinge epithelium was found between the hPSC-derived neural retina (NR) and retinal pigment epithelium (RPE). These data suggest that our culture system provides a new method for generating hPSC-derived retinal cells that, for the first time, might be used in human transplantation.

  3. Retinal vascular oximetry during ranibizumab treatment of central retinal vein occlusion.

    Science.gov (United States)

    Traustason, Sindri; la Cour, Morten; Larsen, Michael

    2014-09-01

    To investigate the effect of intravitreal injections of the vascular endothelial growth factor inhibitor ranibizumab on retinal oxygenation in patients with central retinal vein occlusion (CRVO). Retinal oxygen saturation in patients with CRVO was analysed using the Oxymap Retinal Oximeter P3, before and during 6 months of treatment with intravitreal injections of ranibizumab. At presentation, retinal venous oxygen saturation was lower in eyes with CRVO than in the healthy fellow eyes (32±13% vs 59±10%, respectively, p=0.001) whereas retinal arterial saturation was higher in eyes with CRVO than in the fellow eyes (95%±8% and 91%±3%, p=0.04). Mean visual acuity increased from 51±24 letters ETDRS at baseline to 66±24 and 69±20 letters ETRDS, respectively, at 3 months and 6 months treatment (mean±SD, pcentral retinal thickness was reduced from 697±139 µm to 368±113 µm and 340±96 µm, respectively, from baseline to 3 months and 6 months treatment (pRetinal venous oxygen saturation was markedly reduced in untreated CRVO and was roughly halfway normalised during intravitreal ranibizumab treatment. Retinal artery oxygen saturation was not reduced in CRVO. NCT01360385. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  4. Impact of the administration of a third-generation cephalosporin (3GC) to one-day-old chicks on the persistence of 3GC-resistant Escherichia coli in intestinal flora: An in vivo experiment.

    Science.gov (United States)

    Baron, Sandrine; Jouy, Eric; Touzain, Fabrice; Bougeard, Stéphanie; Larvor, Emeline; de Boisseson, Claire; Amelot, Michel; Keita, Alassane; Kempf, Isabelle

    2016-03-15

    The aim of the experiment was to evaluate under controlled conditions the impact on the excretion of 3GC-resistant Escherichia coli of the injection of one-day-old chicks with ceftiofur, a third-generation cephalosporin (3GC). Three isolators containing specific-pathogen-free chicks were used. In the first one, 20 birds were injected with ceftiofur then ten of them were orally inoculated with a weak inoculum of a 3GC-resistant E. coli field isolate containing an IncI1/ST3 plasmid encoding a blaCTX-M-1 beta-lactamase. The other chicks were kept as contact birds. None of the 20 birds in the second isolator were injected with ceftiofur, but ten of them were similarly inoculated with the 3GC-resistant strain and the others kept as contact birds. A third isolator contained ten non-injected, non-inoculated chicks. Fecal samples were collected regularly over one month and the E. coli isolated on non-supplemented media were characterized by antimicrobial agar dilution, detection of selected resistance genes and determination of phylogenetic group by PCR. The titers of 3GC-resistant E. coli in individual fecal samples were evaluated by culturing on 3GC-supplemented media. Results showed that the inoculated strain rapidly and abundantly colonized the inoculated and contact birds. The ceftiofur injection resulted in significantly higher percentages of 3GC-resistant E. coli isolates among the analyzed E. coli. No transfer of the 3GC-encoding plasmid to other isolates could be evidenced. In conclusion, these results highlight the dramatic capacity of 3GC-resistant E. coli to colonize and persist in chicks, and the selecting pressure imposed by the off-label use of ceftiofur.

  5. Evaluation of skeletal tissue repair, part 2: enhancement of skeletal tissue repair through dual-growth-factor-releasing hydrogels within an ex vivo chick femur defect model.

    Science.gov (United States)

    Smith, E L; Kanczler, J M; Gothard, D; Roberts, C A; Wells, J A; White, L J; Qutachi, O; Sawkins, M J; Peto, H; Rashidi, H; Rojo, L; Stevens, M M; El Haj, A J; Rose, F R A J; Shakesheff, K M; Oreffo, R O C

    2014-10-01

    There is an unmet need for improved, effective tissue engineering strategies to replace or repair bone damaged through disease or injury. Recent research has focused on developing biomaterial scaffolds capable of spatially and temporally releasing combinations of bioactive growth factors, rather than individual molecules, to recapitulate repair pathways present in vivo. We have developed an ex vivo embryonic chick femur critical size defect model and applied the model in the study of novel extracellular matrix (ECM) hydrogel scaffolds containing spatio-temporal combinatorial growth factor-releasing microparticles and skeletal stem cells for bone regeneration. Alginate/bovine bone ECM (bECM) hydrogels combined with poly(d,l-lactic-co-glycolic acid) (PDLLGA)/triblock copolymer (10-30% PDLLGA-PEG-PLDLGA) microparticles releasing dual combinations of vascular endothelial growth factor (VEGF), chondrogenic transforming growth factor beta 3 (TGF-β3) and the bone morphogenetic protein BMP2, with human adult Stro-1+bone marrow stromal cells (HBMSCs), were placed into 2mm central segmental defects in embryonic day 11 chick femurs and organotypically cultured. Hydrogels loaded with VEGF combinations induced host cell migration and type I collagen deposition. Combinations of TGF-β3/BMP2, particularly with Stro-1+HBMSCs, induced significant formation of structured bone matrix, evidenced by increased Sirius red-stained matrix together with collagen expression demonstrating birefringent alignment within hydrogels. This study demonstrates the successful use of the chick femur organotypic culture system as a high-throughput test model for scaffold/cell/growth factor therapies in regenerative medicine. Temporal release of dual growth factors, combined with enriched Stro-1+HBMSCs, improved the formation of a highly structured bone matrix compared to single release modalities. These studies highlight the potential of a unique alginate/bECM hydrogel dual growth factor release

  6. Binding characteristics of brain-derived neurotrophic factor to its receptors on neurons from the chick embryo

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Tebar, A.; Barde, Y.A.

    1988-09-01

    Brain-derived neurotrophic factor (BDNF), a protein known to support the survival of embryonic sensory neurons and retinal ganglion cells, was derivatized with 125I-Bolton-Hunter reagent and obtained in a biologically active, radioactive form (125I-BDNF). Using dorsal root ganglion neurons from chick embryos at 9 d of development, the basic physicochemical parameters of the binding of 125I-BDNF with its receptors were established. Two different classes of receptors were found, with dissociation constants of 1.7 x 10(-11) M (high-affinity receptors) and 1.3 x 10(-9) M (low-affinity receptors). Unlabeled BDNF competed with 125I-BDNF for binding to the high-affinity receptors with an inhibition constant essentially identical to the dissociation constant of the labeled protein: 1.2 x 10(-11) M. The association and dissociation rates from both types of receptors were also determined, and the dissociation constants calculated from these kinetic experiments were found to correspond to the results obtained from steady-state binding. The number of high-affinity receptors (a few hundred per cell soma) was 15 times lower than that of low-affinity receptors. No high-affinity receptors were found on sympathetic neurons, known not to respond to BDNF, although specific binding of 125I-BDNF to these cells was detected at a high concentration of the radioligand. These results are discussed and compared with those obtained with nerve growth factor on the same neuronal populations.

  7. Cholinergic modulation of non-N-methyl-D-aspartic acid glutamatergic transmission in the chick ventral lateral geniculate nucleus.

    Science.gov (United States)

    Guo, J-Z; Sorenson, E M; Chiappinelli, V A

    2010-03-17

    Neurotransmission between glutamatergic terminals of retinal ganglion cells and principal neurons of the ventral lateral geniculate nucleus (LGNv) was examined with patch clamp recordings in chick brain slices during electrical stimulation of the optic tract. Since muscarinic and nicotinic receptors are present in high densities in LGNv, the present study examined possible roles of both receptors in modulating retinogeniculate transmission. During whole-cell recordings from LGNv neurons, acetylcholine (ACh, 100 microM) caused an initial increase in amplitudes of optic tract-evoked non-N-methyl-D-aspartic acid (NMDA) glutamatergic postsynaptic currents (PSCs). This increase was unchanged when 1 microM atropine was present, indicating that this initial enhancement of PSCs was due entirely to activation of nicotinic receptors. However, during washout of ACh the amplitudes of evoked PSCs became significantly decreased by 40.4+/-5.0% for several minutes before recovering to their original amplitudes, an effect blocked by 1 microM atropine. Exogenously applied muscarine (10 microM) markedly depressed optic tract-evoked PSCs, and this decrease in amplitude was blocked by atropine. In a second set of experiments, we examined effects of releasing endogenous ACh prior to optic tract stimulation. This was accomplished by stimulation of the lateral portion of LGNv via a separate conditioning electrode. Following a brief train of low intensity conditioning stimuli, non-NMDA glutamatergic PSCs evoked by optic tract stimulation were potentiated. However, at higher conditioning stimulus intensities the PSCs were markedly decreased compared with control, and this decrease was partially blocked by atropine (1 microM). Neither ACh nor muscarine altered amplitudes of PSCs elicited by exogenously applied glutamate. Muscarine significantly reduced the frequency but not the amplitudes of miniature PSCs, consistent with a presynaptic location for muscarinic receptors mediating these

  8. Idiopathic pediatric retinal artery occlusion

    Directory of Open Access Journals (Sweden)

    Manayath George

    2010-01-01

    Full Text Available We report a case of branch retinal artery occlusion (BRAO in a healthy young girl. An eight-year-old girl presented with sudden loss of vision in her left eye. She had a pale retina with macular edema consistent with extensive BRAO. A thorough workup was performed to determine any etiologic factor. All test results were within normal limits. Her visual acuity improved from finger counting to 20/40 over two weeks, on immediate treatment with intravenous steroids (methyl prednisolone. This case suggests that BRAO can occur in healthy children without any detectable systemic or ocular disorders and a dramatic improvement may be achieved with prompt treatment with intravenous steroids.

  9. Nanoparticles for retinal gene therapy.

    Science.gov (United States)

    Conley, Shannon M; Naash, Muna I

    2010-09-01

    Ocular gene therapy is becoming a well-established field. Viral gene therapies for the treatment of Leber's congentinal amaurosis (LCA) are in clinical trials, and many other gene therapy approaches are being rapidly developed for application to diverse ophthalmic pathologies. Of late, development of non-viral gene therapies has been an area of intense focus and one technology, polymer-compacted DNA nanoparticles, is especially promising. However, development of pharmaceutically and clinically viable therapeutics depends not only on having an effective and safe vector but also on a practical treatment strategy. Inherited retinal pathologies are caused by mutations in over 220 genes, some of which contain over 200 individual disease-causing mutations, which are individually very rare. This review will focus on both the progress and future of nanoparticles and also on what will be required to make them relevant ocular pharmaceutics. Copyright 2010 Elsevier Ltd. All rights reserved.

  10. Laminins and retinal vascular development.

    Science.gov (United States)

    Edwards, Malia M; Lefebvre, Olivier

    2013-01-01

    The mechanisms controlling vascular development, both normal and pathological, are not yet fully understood. Many diseases, including cancer and diabetic retinopathy, involve abnormal blood vessel formation. Therefore, increasing knowledge of these mechanisms may help develop novel therapeutic targets. The identification of novel proteins or cells involved in this process would be particularly useful. The retina is an ideal model for studying vascular development because it is easy to access, particularly in rodents where this process occurs post-natally. Recent studies have suggested potential roles for laminin chains in vascular development of the retina. This review will provide an overview of these studies, demonstrating the importance of further research into the involvement of laminins in retinal blood vessel formation.

  11. Screening of central functions of amino acids and their metabolites for sedative and hypnotic effects using chick models.

    Science.gov (United States)

    Furuse, Mitsuhiro

    2015-09-01

    The chick has a practical advantage in the screening process in that chicks require only small quantities of drugs. The chick separation stress paradigm has traditionally been recognized as a valid form of anxiolytic screening. Further, chick behavior involving standing motionless with eyes closed or sitting motionless with head drooped is nearly always associated with electrophysiological sleep. When centrally administered, some DNA-encoded L-α-amino acids, as well as some DNA-non-encoded amino acids, such as metabolites of L-α-amino acids, D-amino acid and β-amino acid, have shown sedative and/or hypnotic effects in chicks. The effects of some of these amino acids have subsequently been confirmed in humans. In conclusion, the chick model is convenient and useful for screening central functions of amino acids and their metabolites for hypnosis and sedation.

  12. Integration of retinal image sequences

    Science.gov (United States)

    Ballerini, Lucia

    1998-10-01

    In this paper a method for noise reduction in ocular fundus image sequences is described. The eye is the only part of the human body where the capillary network can be observed along with the arterial and venous circulation using a non invasive technique. The study of the retinal vessels is very important both for the study of the local pathology (retinal disease) and for the large amount of information it offers on systematic haemodynamics, such as hypertension, arteriosclerosis, and diabetes. In this paper a method for image integration of ocular fundus image sequences is described. The procedure can be divided in two step: registration and fusion. First we describe an automatic alignment algorithm for registration of ocular fundus images. In order to enhance vessel structures, we used a spatially oriented bank of filters designed to match the properties of the objects of interest. To evaluate interframe misalignment we adopted a fast cross-correlation algorithm. The performances of the alignment method have been estimated by simulating shifts between image pairs and by using a cross-validation approach. Then we propose a temporal integration technique of image sequences so as to compute enhanced pictures of the overall capillary network. Image registration is combined with image enhancement by fusing subsequent frames of a same region. To evaluate the attainable results, the signal-to-noise ratio was estimated before and after integration. Experimental results on synthetic images of vessel-like structures with different kind of Gaussian additive noise as well as on real fundus images are reported.

  13. Photodiode circuits for retinal prostheses.

    Science.gov (United States)

    Loudin, J D; Cogan, S F; Mathieson, K; Sher, A; Palanker, D V

    2011-10-01

    Photodiode circuits show promise for the development of high-resolution retinal prostheses. While several of these systems have been constructed and some even implanted in humans, existing descriptions of the complex optoelectronic interaction between light, photodiode, and the electrode/electrolyte load are limited. This study examines this interaction in depth with theoretical calculations and experimental measurements. Actively biased photoconductive and passive photovoltaic circuits are investigated, with the photovoltaic circuits consisting of one or more diodes connected in series, and the photoconductive circuits consisting of a single diode in series with a pulsed bias voltage. Circuit behavior and charge injection levels were markedly different for platinum and sputtered iridium-oxide film (SIROF) electrodes. Photovoltaic circuits were able to deliver 0.038 mC/cm(2) (0.75 nC/phase) per photodiode with 50- μm platinum electrodes, and 0.54-mC/cm(2) (11 nC/phase) per photodiode with 50-μ m SIROF electrodes driven with 0.5-ms pulses of light at 25 Hz. The same pulses applied to photoconductive circuits with the same electrodes were able to deliver charge injections as high as 0.38 and 7.6 mC/cm(2) (7.5 and 150 nC/phase), respectively. We demonstrate photovoltaic stimulation of rabbit retina in-vitro, with 0.5-ms pulses of 905-nm light using peak irradiance of 1 mW/mm(2). Based on the experimental data, we derive electrochemical and optical safety limits for pixel density and charge injection in various circuits. While photoconductive circuits offer smaller pixels, photovoltaic systems do not require an external bias voltage. Both classes of circuits show promise for the development of high-resolution optoelectronic retinal prostheses.

  14. Human neural progenitor cells promote photoreceptor survival in retinal explants.

    Science.gov (United States)

    Englund-Johansson, Ulrica; Mohlin, Camilla; Liljekvist-Soltic, Ingela; Ekström, Per; Johansson, Kjell

    2010-02-01

    Different types of progenitor and stem cells have been shown to provide neuroprotection in animal models of photoreceptor degeneration. The present study was conducted to investigate whether human neural progenitor cells (HNPCs) have neuroprotective properties on retinal explants models with calpain- and caspase-3-dependent photoreceptor cell death. In the first experiments, HNPCs in a feeder layer were co-cultured for 6 days either with postnatal rd1 mouse or normal rat retinas. Retinal histological sections were used to determine outer nuclear layer (ONL) thickness, and to detect the number of photoreceptors with labeling for calpain activity, cleaved caspase-3 and TUNEL. The ONL thickness of co-cultured rat and rd1 retinas was found to be almost 10% and 40% thicker, respectively, compared to controls. Cell counts of calpain activity, cleaved caspase-3 and TUNEL labeled photoreceptors in both models revealed a 30-50% decrease when co-cultured with HNPCs. The results represent significant increases of photoreceptor survival in the co-cultured retinas. In the second experiments, for an identification of putative survival factors, or a combination of them, a growth factor profile was performed on conditioned medium. The relative levels of various growth factors were analyzed by densitometric measurements of growth factor array membranes. Following growth factors were identified as most potential survival factors; granulocyte colony stimulating factor (G-CSF), granulocyte-macrophage colony stimulating factor (GMCSF), insulin-like growth factor II (IGF-II), neurotrophic factor 3 (NT-3), placental growth factor (PIGF), transforming growth factors (TGF-beta1 and TGF-beta2) and vascular endothelial growth factor (VEGF-D). HNPCs protect both against calpain- and caspase-3-dependent photoreceptor cell death in the rd1 mouse and against caspase-3-dependent photoreceptor cell death in normal rat retinas in vitro. The protective effect is possibly achieved by a variety of

  15. Pyridoxine deficiency affects biomechanical properties of chick tibial bone

    Science.gov (United States)

    Masse, P. G.; Rimnac, C. M.; Yamauchi, M.; Coburn, S. P.; Rucker, R. B.; Howell, D. S.; Boskey, A. L.

    1996-01-01

    The mechanical integrity of bone is dependent on the bone matrix, which is believed to account for the plastic deformation of the tissue, and the mineral, which is believed to account for the elastic deformation. The validity of this model is shown in this study based on analysis of the bones of vitamin B6-deficient and vitamin B6-replete chick bones. In this model, when B6-deficient and control animals are compared, vitamin B6 deficiency has no effect on the mineral content or composition of cortical bone as measured by ash weight (63 +/- 6 vs. 58 +/- 3); mineral to matrix ratio of the FTIR spectra (4.2 +/- 0.6 vs. 4.5 +/- 0.2), line-broadening analyses of the X-ray diffraction 002 peak (beta 002 = 0.50 +/- 0.1 vs. 0.49 +/- 0.01), or other features of the infrared spectra. In contrast, collagen was significantly more extractable from vitamin B6-deficient chick bones (20 +/- 2% of total hydroxyproline extracted vs. 10 +/- 3% p < or = 0.001). The B6-deficient bones also contained an increased amount of the reducible cross-links DHLNL, dehydro-dihydroxylysinonorleucine, (1.03 +/- 0.07 vs. 0.84 +/- 0.13 p < or = 0.001); and a nonsignificant increase in HLNL, dehydro-hydroxylysinonorleucine, (0.51 +/- 0.03 vs. 0.43 +/- 0.03, p < or = 0.10). There were no significant changes in bone length, bone diameter, or area moment of inertia. In four-point bending, no significant changes in elastic modulus, stiffness, offset yield deflection, or fracture deflection were detected. However, fracture load in the B6-deficient animals was decreased from 203 +/- 35 MPa to 151 +/- 23 MPa, p < or = 0.01, and offset yield load was decreased from 165 +/- 9 MPa to 125 +/- 14 MPa, p < or = 0.05. Since earlier histomorphometric studies had demonstrated that the B6-deficient bones were osteopenic, these data suggest that although proper cortical bone mineralization occurred, the alterations of the collagen resulted in changes to bone mechanical performance.

  16. Characterization of human fetal retinal pigment epithelial cells in culture:proliferation rate and marker expression%胎儿视网膜色素上皮细胞的原代培养和体外增殖能力的测定

    Institute of Scientific and Technical Information of China (English)

    袁松涛; 薛志刚; 林卿; 刘庆淮; 范国平

    2014-01-01

    Objective Age-related macular degeneration (AMD) is a common eye disease, causing irreversible blindness in senior people. One of the major pathogenic mechanisms of AMD is the dysfunction and loss of the retinal pigment epithelium (RPE). Therefore, RPE cell transplantation is considered as a promising approach to treat AMD. Human fetal RPE (fRPE) appears to be a promising cell type for RPE cell transplantation. In this study, we aim to set-up a simple fRPE culture protocol for future clinical trials. Method fRPE cells in this experiment came from donated fetal eyes after abortion. RPE layer was dissected out from the choroid plexus under dissecting microscope. RPE patches were treated with trypsin until fully disassociated. Cell suspension was seeded on Matrigel coated plastic culture plate. When primary fRPE reached confluency within 2 weeks in culture, cells were passaged, expanded, and frozen. Results No obvious differences were observed between fRPE from different donors. fRPE cells can be continuously passaged for 3-4 passages. Virtually 100﹪cells exhibited typical RPE cell morphology during in vitro expansion. Immunostaining confirmed the expression of typical RPE markers in cultured fRPE cells. Conclusion Our results indicated that fRPE can be cultured and expanded rapidly in vitro without the alteration of RPE cell character. We suggest that fRPE cells be further tested for safety and efficacy via cell transplantation in AMD animal models before clinical trial in AMD patients.%目的:建立胎儿视网膜色素上皮细胞(fRPE)的原代培养方法。方法分离流产胎儿RPE,并进行体外原代培养、传代,免疫荧光检测培养RPE细胞分子标志物。以β细胞增殖诱导剂(二芳基脲衍生物WS3)刺激RPE细胞增殖,并测量其生长曲线。3组细胞比较采用单因素F检验。结果源自不同胎儿的fRPE细胞在原代及体外增殖中并未表现出明显不同。在体外扩增的4代fRPE中,100

  17. Bone marrow mesenchymal stem cells stimulate proliferation and neuronal differentiation of retinal progenitor cells.

    Directory of Open Access Journals (Sweden)

    Jing Xia

    Full Text Available During retina development, retinal progenitor cell (RPC proliferation and differentiation are regulated by complex inter- and intracellular interactions. Bone marrow mesenchymal stem cells (BMSCs are reported to express a variety of cytokines and neurotrophic factors, which have powerful trophic and protective functions for neural tissue-derived cells. Here, we show that the expanded RPC cultures treated with BMSC-derived conditioned medium (CM which was substantially enriched for bFGF and CNTF, expressed clearly increased levels of nuclear receptor TLX, an essential regulator of neural stem cell (NSC self-renewal, as well as betacellulin (BTC, an EGF-like protein described as supporting NSC expansion. The BMSC CM- or bFGF-treated RPCs also displayed an obviously enhanced proliferation capability, while BMSC CM-derived bFGF knocked down by anti-bFGF, the effect of BMSC CM on enhancing RPC proliferation was partly reversed. Under differentiation conditions, treatment with BMSC CM or CNTF markedly favoured RPC differentiation towards retinal neurons, including Brn3a-positive retinal ganglion cells (RGCs and rhodopsin-positive photoreceptors, and clearly diminished retinal glial cell differentiation. These findings demonstrate that BMSCs supported RPC proliferation and neuronal differentiation which may be partly mediated by BMSC CM-derived bFGF and CNTF, reveal potential limitations of RPC culture systems, and suggest a means for optimizing RPC cell fate determination in vitro.

  18. [Intraocular hypertension after retinal detachment surgery].

    Science.gov (United States)

    Muşat, O; Cristescu, R; Coman, Corina; Asandi, R

    2012-01-01

    This papers presents a case of a patient with retinal detachment, 3 days ago operated (posterior vitrectomy, internal tamponament with silicon oil 1000) who developed increased ocular pressure following silicon oil output in the anterior chamber.

  19. [Retinal vein occlusion in a young patient].

    Science.gov (United States)

    Zemba, Mihail; Ochinciuc, Uliana; Sarbu, Laura; Avram, Corina; Camburu, Raluca; Stamate, Alina

    2013-01-01

    We present a case report of a 27 years old pacient with central retinal vein occlussion and macular edema. The pacient has a significant reduction of the macular aedema with complete recovery of vision after the treatment.

  20. The treatment of bullous rhegmatogenous retinal detachment.

    Science.gov (United States)

    Wong, D; Chignell, A H; Inglesby, D V; Little, B C; Franks, W

    1992-01-01

    We describe the results of a consecutive series of 97 cases of bullous superior retinal detachment treated by conventional surgery. The retinal detachments were characterized by either a single retinal break or multiple retinal breaks confined within 1 clock hour and no proliferative vitreoretinopathy. The surgery involved sequential drainage of subretinal fluid, injection of air, cryotherapy and the application of local explant. All cases would otherwise be suitable for pneumatic retinopexy. The anatomical success rate was 85.5% with a single operation and 97% with further procedures. We report on the complications encountered and appraise the advantages and disadvantages of this operation. Forty-five of the 97 cases had detachment of the macula for less than 2 weeks, and 35 of the 45 (80%) achieved a visual acuity of 6/18 or better. These visual results challenge the assertion that better visual outcome might be attained with pneumatic retinopexy.

  1. [Ocular hypertension after surgery for retinal detachment].

    Science.gov (United States)

    Muşat, O; Cristescu, R; Coman, Corina; Asandi, R

    2012-01-01

    This papers presents a case of a patient with retinal detachement, 3 days ago operated (posterior vitrectomy internal tamponament with silicon oil 1000) who develop increased ocular pressure following silicon oil output in the anterior chamber.

  2. Imaging retinal mosaics in the living eye.

    Science.gov (United States)

    Rossi, E A; Chung, M; Dubra, A; Hunter, J J; Merigan, W H; Williams, D R

    2011-03-01

    Adaptive optics imaging of cone photoreceptors has provided unique insight into the structure and function of the human visual system and has become an important tool for both basic scientists and clinicians. Recent advances in adaptive optics retinal imaging instrumentation and methodology have allowed us to expand beyond cone imaging. Multi-wavelength and fluorescence imaging methods with adaptive optics have allowed multiple retinal cell types to be imaged simultaneously. These new methods have recently revealed rod photoreceptors, retinal pigment epithelium (RPE) cells, and the smallest retinal blood vessels. Fluorescence imaging coupled with adaptive optics has been used to examine ganglion cells in living primates. Two-photon imaging combined with adaptive optics can evaluate photoreceptor function non-invasively in the living primate retina.

  3. Regulatory and Economic Considerations of Retinal Drugs.

    Science.gov (United States)

    Shah, Ankoor R; Williams, George A

    2016-01-01

    The advent of anti-VEGF therapy for neovascular age-related macular degeneration and macular edema secondary to retinal vein occlusion and diabetes mellitus has prevented blindness in tens of thousands of people. However, the costs of these drugs are without precedent in ophthalmic drug therapeutics. An analysis of the financial implications of retinal drugs and the impact of the Food and Drug Administration on treatment of retinal disease must include not only an evaluation of the direct costs of the drugs and the costs associated with their administration, but also the cost savings which accrue from their clinical benefit. This chapter will discuss the financial and regulatory issues associated with retinal drugs.

  4. Influence of hydrogen peroxide in drinking water on diazepam pharmacokinetics in chicks

    Directory of Open Access Journals (Sweden)

    Yaareb J. Mousa

    Full Text Available Aim: Stressful conditions affect drug pharmacokinetics and pharmacodynamics. This study examines the effect of hydrogen peroxide (H2O2 in drinking water on the pharmacokinetics of diazepam in a chick model of oxidative stress. Materials and Methods: Day old chicks were either provided with plane tap water (control group or H2O2 in tap water as 0.5% v/v drinking solution for two weeks in order to produce oxidative stress. On treatment days 7–14, the chicks were treated with a sedative dose of diazepam at 10 mg/kg, intramuscularly. Blood samples were obtained from chicks (5/each sampling time at times of between 0.17 to 4 h. The concentrations of diazepam in the plasma were determined by an HPLC method with UV-detector. Pharmacokinetic parameters of diazepam were calculated from the mean drug concentrations in the plasma by a non-compartmental analysis using a Windows-based computer program. Results: Injection of diazepam resulted in the appearance of the drug in the plasma of control and H2O2 -treated chicks at mean concentrations ranging between 0.11 to 0.444 and 0.131 to 0.535 μg/ml, respectively when measured between 0.17 to 4 h after administration. Diazepam concentrations of the H O -treated chicks were significantly higher than those of the control group at the sampling times 0.5, 0.75, 1 and 4 h. The highest concentration of diazepam in the plasma of both the control and H2O2 treated chicks occurred one h after the injection. The elimination half-life, mean residence time, maximum plasma concentration, area under the moment curve and area under plasma concentration-time curve in the H2O2 -treated chicks were higher than those of the control group by 35, 28, 23, 91 and 49%, respectively. Correspondingly, the steady state volume of distribution, elimination rate constant and total body clearance in the H2O2 -treated chicks decreased from those of the respective control values by 15, 24 and 33%. Conclusion: The data suggest that oral

  5. Passive transfer of maternal antibodies to West Nile virus in flamingo chicks (Phoenicopterus chilensis and Phoenicopterus ruber ruber).

    Science.gov (United States)

    Baitchman, Eric J; Tlusty, Michael F; Murphy, Hayley W

    2007-06-01

    Passive transfer of maternal antibodies against West Nile virus (WNV) was studied in a captive population of Chilean (Phoenicopterus chilensis) and Caribbean flamingos (Phoenicopterus ruber ruber). Transfer of WNV antibodies from hens to chicks was documented and measured by plaque-reduction neutralization test. Hen titers were significantly correlated to chick titers. Mean half-life of maternal WNV antibodies was 13.4 days in chicks for which half-life was measurable.

  6. [Treatment of retinal detachment with macular hole].

    Science.gov (United States)

    Pikulski, Z; Nawrocki, J; Dziegielewski, K

    1993-01-01

    The methods and results of surgery in 6 cases of retinal detachment with macular hole are presented. In all 6 cases pars plana vitrectomy was performed, in 4 with subsequent SF6 and in 2 with silicone oil tamponade. Retinal attachment was achieved in 4 eyes. Visual acuity 1/50-2/50 was found after surgery in 5 cases. The follow-up ranged from 6 to 9 months.

  7. Complete Blood Count and Retinal Vessel Calibers

    OpenAIRE

    Gerald Liew; Jie Jin Wang; Elena Rochtchina; Tien Yin Wong; Paul Mitchell

    2014-01-01

    OBJECTIVE: The influence of hematological indices such as complete blood count on microcirculation is poorly understood. Retinal microvasculature can be directly visualized and vessel calibers are associated with a range of ocular and systemic diseases. We examined the association of complete blood count with retinal vessel calibers. METHODS: Cross-sectional population-based Blue Mountains Eye Study, n = 3009, aged 49+ years. Complete blood count was measured from fasting blood samples taken ...

  8. Branch retinal artery occlusion in Susac's syndrome

    Directory of Open Access Journals (Sweden)

    Ricardo Evangelista Marrocos de Aragão

    2015-02-01

    Full Text Available Susac's syndrome is a rare disease attribuited to a microangiopathy involving the arterioles of the cochlea, retina and brain. Encefalopathy, hearing loss, and visual deficits are the hallmarks of the disease. Visual loss is due to multiple, recurrent branch arterial retinal occlusions. We report a case of a 20-year-old women with Susac syndrome presented with peripheral vestibular syndrome, hearing loss, ataxia, vertigo, and vision loss due occlusion of the retinal branch artery.

  9. Programming Retinal Stem Cells into Cone Photoreceptors

    Science.gov (United States)

    2015-12-01

    this grant, we sought to investigate the mechanisms that regulate the earliest events in cone photoreceptor development and to exploit this knowledge...the mRNA for three transcription factors promoted cone photoreceptor formation in retinal stem cells derived from human embryonic stem cells. These...reverse vision loss. 15. SUBJECT TERMS Cone photoreceptor, retina, retinal stem cell, Otx2, Onecut1, Blimp1, RNA-seq., transcription factors, and

  10. Current surgery of retinal detachment recurrence. Review

    Directory of Open Access Journals (Sweden)

    V. D. Zakharov

    2012-01-01

    Full Text Available this review presents a detailed analysis and an experience of surgical treatment of retinal detachment recurrence associated with light silicone oil tamponade of vitreous cavity. Approaches and variants of treatment were described in the historical aspect and till now. there are considered general and particular issues in case of retinal detachment recurrence appearance, expediency and volume of intraoperative manipulations, time of operation and choice of temporary substitute of vitreous body for a purpose of postoperative tamponade of vitreous cavity.

  11. Current surgery of retinal detachment recurrence. Review

    Directory of Open Access Journals (Sweden)

    V. D. Zakharov

    2014-07-01

    Full Text Available this review presents a detailed analysis and an experience of surgical treatment of retinal detachment recurrence associated with light silicone oil tamponade of vitreous cavity. Approaches and variants of treatment were described in the historical aspect and till now. there are considered general and particular issues in case of retinal detachment recurrence appearance, expediency and volume of intraoperative manipulations, time of operation and choice of temporary substitute of vitreous body for a purpose of postoperative tamponade of vitreous cavity.

  12. Fluid vitreous substitutes in vitreo retinal surgery

    OpenAIRE

    Saxena Sandeep; Gopal Lingam

    1996-01-01

    Advances in the surgical instrumentation and vitreoretinal techniques have allowed intraoperative reapproximation of retina to a more normal position. The use of intravitreally injected liquid materials (viscoelastic liquids, liquid perfluorocarbons and silicone oil), as adjunctive agents to vitreo-retinal surgery play an important role in facilitating retinal reattachment. These materials are used as intraoperative instruments to re-establish intraocular volume, assist in separating membrane...

  13. Safety of iPhone retinal photography.

    Science.gov (United States)

    Hong, Sheng Chiong; Wynn-Williams, Giles; Wilson, Graham

    2017-04-01

    With the advancement in mobile technology, smartphone retinal photography is becoming a popular practice. However, there is limited information about the safety of the latest smartphones used for retinal photography. This study aims to determine the photobiological risk of iPhone 6 and iPhone 6 plus when used in conjunction with a 20Diopter condensing lens for retinal photography. iPhone 6 and iPhone 6 plus (Apple, Cupertino, CA) were used in this study. The geometrical setup of the study was similar to the indirect ophthalmoscopy technique. The phone was set up at one end of the bench with its flash turned on at maximal brightness; a 20 Dioptre lens was placed 15 cm away from the phone. The light that passes through the lens was measured with a spectroradiometer and an illuminance probe at the other end to determine the spectral profile, spatial irradiance, radiant power emitted by the phone's flash. Trigonometric and lens formula were applied to determine the field of view and retinal surface in order to determine the weighted retinal irradiance and weighted retinal radiant exposure. Taking ocular transmission and the distribution of the beam's spatial irradiance into account, the weighted retinal irradiance is 1.40 mW/cm(2) and the weighted retinal radiant exposure is 56.25 mJ/cm(2). The peak weighted foveal irradiance is 1.61 mW/cm(2). Our study concluded that the photobiological risk posed by iPhone 6 indirect ophthalmoscopy was at least 1 order of magnitude below the safety limits set by the ISO15004-2.2.

  14. Tetrandrine protects mouse retinal ganglion cells from ischemic injury

    Directory of Open Access Journals (Sweden)

    Li WY

    2014-03-01

    Full Text Available Weiyi Li,1,2 Chen Yang,2 Jing Lu,2 Ping Huang,1 Colin J Barnstable,2 Chun Zhang,1 Samuel S Zhang2,3 1Department of Ophthalmology, Peking University Third Hospital, Peking University Eye Center, Beijing, People's Republic of China; 2Department of Neural and Behavioral Sciences, Penn State University, Hershey, PA, USA; 3Singapore Eye Research Institute, Singapore National Eye Centre, Singapore Abstract: This study aimed to determine the protective effects of tetrandrine (Tet on murine ischemia-injured retinal ganglion cells (RGCs. For this, we used serum deprivation cell model, glutamate and hydrogen peroxide (H2O2-induced RGC-5 cell death models, and staurosporine-differentiated neuron-like RGC-5 in vitro. We also investigated cell survival of purified primary-cultured RGCs treated with Tet. An in vivo retinal ischemia/reperfusion model was used to examine RGC survival after Tet administration 1 day before ischemia. We found that Tet affected RGC-5 survival in a dose- and time-dependent manner. Compared to dimethyl sulfoxide treatment, Tet increased the numbers of RGC-5 cells by 30% at 72 hours. After 48 hours, Tet protected staurosporine-induced RGC-5 cells from serum deprivation-induced cell death and significantly increased the relative number of cells cultured with 1 mM H2O2 (P<0.01. Several concentrations of Tet significantly prevented 25-mM-glutamate-induced cell death in a dose-dependent manner. Tet also increased primary RGC survival after 72 and 96 hours. Tet administration (10 µM, 2 µL 1 day before retinal ischemia showed RGC layer loss (greater survival, which was less than those in groups with phosphate-buffered saline intravitreal injection plus ischemia in the central (P=0.005, n=6, middle (P=0.018, n=6, and peripheral (P=0.017, n=6 parts of the retina. Thus, Tet conferred protective effects on serum deprivation models of staurosporine-differentiated neuron-like RGC-5 cells and primary cultured murine RGCs. Furthermore, Tet showed

  15. Diagnostic imaging in patients with retinitis pigmentosa.

    Science.gov (United States)

    Mitamura, Yoshinori; Mitamura-Aizawa, Sayaka; Nagasawa, Toshihiko; Katome, Takashi; Eguchi, Hiroshi; Naito, Takeshi

    2012-01-01

    Retinitis pigmentosa (RP) is a progressive inherited retinal disease, and patients with RP have reduced visual function caused by a degeneration of the photoreceptors and retinal pigment epithelium (RPE). At the end stage of RP, the degeneration of the photoreceptors in the fovea reduces central vision, and RP is one of the main causes of acquired blindness in developed countries. Therefore, morphological and functional assessments of the photoreceptors in the macula area can be useful in estimating the residual retinal function in RP patients. Optical coherence tomography (OCT) is a well-established method of examining the retinal architecture in situ. The photoreceptor inner/outer segment (IS/OS) junction is observed as a distinct, highly reflective line by OCT. The presence of the IS/OS junction in the OCT images is essential for normal visual function. Fundus autofluorescence (FAF) results from the accumulation of lipofuscin in the RPE cells and has been used to investigate RPE and retinal function. More than one-half of RP patients have an abnormally high density parafoveal FAF ring (AF ring). The AF ring represents the border between functional and dysfunctional retina. In this review, we shall summarize recent progress on diagnostic imaging in eyes with RP.

  16. Retinal Vascular Fractals and Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Yi-Ting Ong

    2014-08-01

    Full Text Available Background: Retinal microvascular network changes have been found in patients with age-related brain diseases such as stroke and dementia including Alzheimer's disease. We examine whether retinal microvascular network changes are also present in preclinical stages of dementia. Methods: This is a cross-sectional study of 300 Chinese participants (age: ≥60 years from the ongoing Epidemiology of Dementia in Singapore study who underwent detailed clinical examinations including retinal photography, brain imaging and neuropsychological testing. Retinal vascular parameters were assessed from optic disc-centered photographs using a semiautomated program. A comprehensive neuropsychological battery was administered, and cognitive function was summarized as composite and domain-specific Z-scores. Cognitive impairment no dementia (CIND and dementia were diagnosed according to standard diagnostic criteria. Results: Among 268 eligible nondemented participants, 78 subjects were categorized as CIND-mild and 69 as CIND-moderate. In multivariable adjusted models, reduced retinal arteriolar and venular fractal dimensions were associated with an increased risk of CIND-mild and CIND-moderate. Reduced fractal dimensions were associated with poorer cognitive performance globally and in the specific domains of verbal memory, visuoconstruction and visuomotor speed. Conclusion: A sparser retinal microvascular network, represented by reduced arteriolar and venular fractal dimensions, was associated with cognitive impairment, suggesting that early microvascular damage may be present in preclinical stages of dementia.

  17. Retinal iron homeostasis in health and disease

    Directory of Open Access Journals (Sweden)

    Delu eSong

    2013-06-01

    Full Text Available Iron is essential for life, but excess iron can be toxic. As a potent free radical creator, iron generates hydroxyl radicals leading to significant oxidative stress. Since iron is not excreted from the body, it accumulates with age in tissues, including the retina, predisposing to age-related oxidative insult. Both hereditary and acquired retinal diseases are associated with increased iron levels. For example, retinal degenerations have been found in hereditary iron overload disorders, like aceruloplasminemia, Friedreich’s ataxia, and pantothenate kinase-associated neurodegeneration. Similarly, mice with targeted mutation of the iron exporter ceruloplasmin and its homolog hephaestin showed age-related retinal iron accumulation and retinal degeneration with features resembling human age-related macular degeneration (AMD. Post mortem AMD eyes have increased levels of iron in retina compared to age-matched healthy donors. Iron accumulation in AMD is likely to result, in part, from inflammation, hypoxia, and oxidative stress, all of which can cause iron dysregulation. Fortunately, it has been demonstrated by in vitro and in vivo studies that iron in the retinal pigment epithelium and retina is chelatable. Iron chelation protects photoreceptors and retinal pigment epithelial cells (RPE in a variety of mouse models. This has therapeutic potential for diminishing iron-induced oxidative damage to prevent or treat AMD.

  18. Therapeutical trials with antimicrobial agents and cultured cecal microflora in Salmonella infantis infections in chickens.

    Science.gov (United States)

    Seuna, E; Nurmi, E

    1979-09-01

    The efficacy of short antimicrobial therapy was examined in chicks infected with S. infantis on the day of hatching. An attempt was made to prevent the reappearance of salmonellae by treating the chicks with a culture of cecal microflora to re-establish the normal intestinal flora. The following drugs were used: neomycin/polymyxin, oxytetracyline/neomycin, dihydrostreptomycin, furazolidone, and trimethoprim/sulphadiazine. The oxytetracycline/neomycin therapy was most effective, but reappearance of the infection was not avoided. Combined therapy with other antimicrobials and the culture reduced the number of infected chicks compared with the respective control groups. A slight reduction was also found when the culture was used alone without any preceding antimicrobial treatment.

  19. In Ovo injection of betaine affects hepatic cholesterol metabolism through epigenetic gene regulation in newly hatched chicks.

    Science.gov (United States)

    Hu, Yun; Sun, Qinwei; Li, Xiaoliang; Wang, Min; Cai, Demin; Li, Xi; Zhao, Ruqian

    2015-01-01

    Betaine is reported to regulate hepatic cholesterol metabolism in mammals. Chicken eggs contain considerable amount of betaine, yet it remains unknown whether and how betaine in the egg affects hepatic cholesterol metabolism in chicks. In this study, eggs were injected with betaine at 2.5 mg/egg and the hepatic cholesterol metabolism was investigated in newly hatched chicks. Betaine did not affect body weight or liver weight, but significantly increased the serum concentration (P betaine-treated chicks. Meanwhile, hepatic protein contents of DNA methyltransferases 1 and adenosylhomocysteinase-like 1 were increased (P betaine injection regulates hepatic cholesterol metabolism in chicks through epigenetic mechanisms including DNA and histone methylations.

  20. From confluent human iPS cells to self-forming neural retina and retinal pigmented epithelium.

    Science.gov (United States)

    Reichman, Sacha; Terray, Angélique; Slembrouck, Amélie; Nanteau, Céline; Orieux, Gaël; Habeler, Walter; Nandrot, Emeline F; Sahel, José-Alain; Monville, Christelle; Goureau, Olivier

    2014-06-10

    Progress in retinal-cell therapy derived from human pluripotent stem cells currently faces technical challenges that require the development of easy and standardized protocols. Here, we developed a simple retinal differentiation method, based on confluent human induced pluripotent stem cells (hiPSC), bypassing embryoid body formation and the use of exogenous molecules, coating, or Matrigel. In 2 wk, we generated both retinal pigmented epithelial cells and self-forming neural retina (NR)-like structures containing retinal progenitor cells (RPCs). We report sequential differentiation from RPCs to the seven neuroretinal cell types in maturated NR-like structures as floating cultures, thereby revealing the multipotency of RPCs generated from integration-free hiPSCs. Furthermore, Notch pathway inhibition boosted the generation of photoreceptor precursor cells, crucial in establishing cell therapy strategies. This innovative process proposed here provides a readily efficient and scalable approach to produce retinal cells for regenerative medicine and for drug-screening purposes, as well as an in vitro model of human retinal development and disease.

  1. Ursodeoxycholic Acid Attenuates Endoplasmic Reticulum Stress-Related Retinal Pericyte Loss in Streptozotocin-Induced Diabetic Mice

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    Yoo-Ri Chung

    2017-01-01

    Full Text Available Loss of pericytes, an early hallmark of diabetic retinopathy (DR, results in breakdown of the blood-retinal barrier. Endoplasmic reticulum (ER stress may be involved in this process. The purpose of this study was to examine the effects of ursodeoxycholic acid (UDCA, a known ameliorator of ER stress, on pericyte loss in DR of streptozotocin- (STZ- induced diabetic mice. To assess the extent of DR, the integrity of retinal vessels and density of retinal capillaries in STZ-induced diabetic mice were evaluated. Additionally, induction of ER stress and the unfolded protein response (UPR were assessed in diabetic mice and human retinal pericytes exposed to advanced glycation end products (AGE or modified low-density lipoprotein (mLDL. Fluorescein dye leakage during angiography and retinal capillary density were improved in UDCA-treated diabetic mice, compared to the nontreated diabetic group. Among the UPR markers, those involved in the protein kinase-like ER kinase (PERK pathway were increased, while UDCA attenuated UPR in STZ-induced diabetic mice as well as AGE- or mLDL-exposed retinal pericytes in culture. Consequently, vascular integrity was improved and pericyte loss reduced in the retina of STZ-induced diabetic mice. Our findings suggest that UDCA might be effective in protecting against DR.

  2. A mechanistic link between chick diet and decline in seabirds?

    Science.gov (United States)

    Kitaysky, A.S.; Kitaiskaia, E.V.; Piatt, J.F.; Wingfield, J.C.

    2006-01-01

    A climatic regime shift during the mid-1970s in the North Pacific resulted in decreased availability of lipidrich fish to seabirds and was followed by a dramatic decline in number of kittiwakes breeding on the Pribilof Islands. Although production of chicks in the mid-1970s was adequate to sustain kittiwake populations in the early 1980s, the disappearance of birds from breeding colonies apparently exceeded recruitment. No mechanism has been proposed to explain why recruitment would differ among fledglings fed lipid-rich or lipid-poor fish during development. Here we show that diets low in lipids induce nutritional stress and impair cognitive abilities in young red-legged kittiwakes, Rissa brevirostris. Specifically, growth retardation, increased secretion of stress hormones and inferior ability to associate food distribution with visual cues were observed in individuals fed lipid-poor diets. We conclude that lipid-poor diets during development affect the quality of young seabirds, which is likely to result in their increased mortality and low recruitment. ?? 2005 The Royal Society.

  3. Maturation of firing pattern in chick vestibular nucleus neurons.

    Science.gov (United States)

    Shao, M; Hirsch, J C; Peusner, K D

    2006-08-25

    The principal cells of the chick tangential nucleus are vestibular nucleus neurons participating in the vestibuloocular and vestibulocollic reflexes. In birds and mammals, spontaneous and stimulus-evoked firing of action potentials is essential for vestibular nucleus neurons to generate mature vestibular reflex activity. The emergence of spike-firing pattern and the underlying ion channels were studied in morphologically-identified principal cells using whole-cell patch-clamp recordings from brain slices of late-term embryos (embryonic day 16) and hatchling chickens (hatching day 1 and hatching day 5). Spontaneous spike activity emerged around the perinatal period, since at embryonic day 16 none of the principal cells generated spontaneous action potentials. However, at hatching day 1, 50% of the cells fired spontaneously (range, 3 to 32 spikes/s), which depended on synaptic transmission in most cells. By hatching day 5, 80% of the principal cells could fire action potentials spontaneously (range, 5 to 80 spikes/s), and this activity was independent of synaptic transmission and showed faster kinetics than at hatching day 1. Repetitive firing in response to depolarizing pulses appeared in the principal cells starting around embryonic day 16, when calcium-dependent potassium current modulated both the spontaneous and evoked spike firing activity. Altogether, these in vitro studies showed that during the perinatal period, the principal cells switched from displaying no spontaneous spike activity at resting membrane potential and generating one spike on depolarization to the tonic firing of spontaneous and evoked action potentials.

  4. Cleavage events and sperm dynamics in chick intrauterine embryos.

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    Hyung Chul Lee

    Full Text Available This study was undertaken to elucidate detailed event of early embryogenesis in chicken embryos using a noninvasive egg retrieval technique before oviposition. White Leghorn intrauterine eggs were retrieved from 95 cyclic hens aged up to 54-56 weeks and morphogenetic observation was made under both bright field and fluorescent image in a time course manner. Differing from mammals, asymmetric cleavage to yield preblastodermal cells was observed throughout early embryogenesis. The first two divisions occurred synchronously and four polarized preblastodermal cells resulted after cruciform cleavage. Then, asynchronous cleavage continued in a radial manner and overall cell size in the initial cleavage region was smaller than that in the distal area. Numerous sperms were visible, regardless of zygotic nuclei formation. Condensed sperm heads were present mainly in the perivitelline space and cytoplasm, and rarely in the yolk region, while decondensed sperm heads were only visible in the yolk. In conclusion, apparent differences in sperm dynamics and early cleavage events compared with mammalian embryos were detected in chick embryo development, which demonstrated polarized cleavage with penetrating supernumerary sperm into multiple regions.

  5. Bacteria Isolations from Broiler and Layer Chicks in Zambia

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    Hetron Mweemba Munang’andu

    2012-01-01

    Full Text Available Chick mortality (CM is one of the major constraints to the expansion of the poultry industry in Zambia. Of the 2,829 avian disease cases submitted to the national diagnostic laboratory based at the Central Veterinary Research Institute in Lusaka between 1995 and 2007, 34.39% (973/2,829 were from CM cases. The disease accounted for 40.2% (218,787/544,903 mortality in the affected flocks with 89.6% (196,112/218,787 of the affected birds dying within seven days. Major bacteria species involved were Escherichia coli, Salmonella gallinarum, and Proteus species being isolated from 84.58%, 46.15%, and 26.93% of the reported CM cases (n=973, respectively. Detection of Salmonella typhimurium, Salmonella enteritidis, and Salmonella dublin indicates that poultry has the potential of transmitting zoonotic pathogenic bacteria to humans. The proportion of Salmonella gallinarum reactors in the adult breeding stock was generally low (<0.5% throughout the study period although its prevalence in CM cases was correlated (r=0.68, P<0.011 with seroprevalence of the same pathogen in the adult breeding stock. Given that the disease accounts for a large proportion of the avian diseases in Zambia as shown in the present study (34.39%, n=2,829, it is imperative that an effective disease control strategy aimed at reducing its occurrence should be developed.

  6. Mechanical origins of rightward torsion in early chick brain development

    Science.gov (United States)

    Chen, Zi; Guo, Qiaohang; Dai, Eric; Taber, Larry

    2015-03-01

    During early development, the neural tube of the chick embryo undergoes a combination of progressive ventral bending and rightward torsion. This torsional deformation is one of the major organ-level left-right asymmetry events in development. Previous studies suggested that bending is mainly due to differential growth, however, the mechanism for torsion remains poorly understood. Since the heart almost always loops rightwards that the brain twists, researchers have speculated that heart looping affects the direction of brain torsion. However, direct evidence is lacking, nor is the mechanical origin of such torsion understood. In our study, experimental perturbations show that the bending and torsional deformations in the brain are coupled and that the vitelline membrane applies an external load necessary for torsion to occur. Moreover, the asymmetry of the looping heart gives rise to the chirality of the twisted brain. A computational model and a 3D printed physical model are employed to help interpret these findings. Our work clarifies the mechanical origins of brain torsion and the associated left-right asymmetry, and further reveals that the asymmetric development in one organ can induce the asymmetry of another developing organ through mechanics, reminiscent of D'Arcy Thompson's view of biological form as ``diagram of forces''. Z.C. is supported by the Society in Science - Branco Weiss fellowship, administered by ETH Zurich. L.A.T acknowledges the support from NIH Grants R01 GM075200 and R01 NS070918.

  7. The birth of quail chicks after intracytoplasmic sperm injection.

    Science.gov (United States)

    Mizushima, Shusei; Hiyama, Gen; Shiba, Kogiku; Inaba, Kazuo; Dohra, Hideo; Ono, Tamao; Shimada, Kiyoshi; Sasanami, Tomohiro

    2014-10-01

    Intracytoplasmic sperm injection (ICSI) has been successfully used to produce offspring in several mammalian species including humans. However, ICSI has not been successful in birds because of the size of the egg and difficulty in mimicking the physiological polyspermy that takes place during normal fertilization. Microsurgical injection of 20 or more spermatozoa into an egg is detrimental to its survival. Here, we report that injection of a single spermatozoon with a small volume of sperm extract (SE) or its components led to the development and birth of healthy quail chicks. SE contains three factors - phospholipase Cζ (PLCZ), aconitate hydratase (AH) and citrate synthase (CS) - all of which are essential for full egg activation and subsequent embryonic development. PLCZ induces an immediate, transient Ca(2+) rise required for the resumption of meiosis. AH and CS are required for long-lasting, spiral-like Ca(2+) oscillations within the activated egg, which are essential for cell cycle progression in early embryos. We also found that co-injection of cRNAs encoding PLCZ, AH and CS support the full development of ICSI-generated zygotes without the use of SE. These findings will aid our understanding of the mechanism of avian fertilization and embryo development, as well as assisting in the manipulation of the avian genome and the production of transgenic and cloned birds.

  8. Comparative studies in Rous sarcoma with virus, tumor cells, and chick embryo cells transformed in vitro by virus. II. Response of normal and immunized chicks.

    Science.gov (United States)

    DOUGHERTY, R M; MORGAN, H R

    1962-01-01

    Chick embryo fibroblasts infected in vitro with Rous sarcoma virus have properties similar to tumor cells when injected into virus-immune chickens. When such virus-transformed fibroblasts are injected into normal chickens, they apparently participate in the production of tumors independent of their release of virus and are thus apparently malignant in vivo.

  9. Sex-based differences in Adelie penguin (Pygoscelis adeliae) chick growth rates.

    Science.gov (United States)

    Jennings, Scott; Varsani, Arvind; Dugger, Catherine; Ballard, Grant; Ainley, David G.

    2016-01-01

    Sexually size-dimorphic species must show some difference between the sexes in growth rate and/or length of growing period. Such differences in growth parameters can cause the sexes to be impacted by environmental variability in different ways, and understanding these differences allows a better understanding of patterns in productivity between individuals and populations. We investigated differences in growth rate and diet between male and female Adélie Penguin (Pygoscelis adeliae) chicks during two breeding seasons at Cape Crozier, Ross Island, Antarctica. Adélie Penguins are a slightly dimorphic species, with adult males averaging larger than adult females in mass (~11%) as well as bill (~8%) and flipper length (~3%). We measured mass and length of flipper, bill, tibiotarsus, and foot at 5-day intervals for 45 male and 40 female individually-marked chicks. Chick sex was molecularly determined from feathers. We used linear mixed effects models to estimate daily growth rate as a function of chick sex, while controlling for hatching order, brood size, year, and potential variation in breeding quality between pairs of parents. Accounting for season and hatching order, male chicks gained mass an average of 15.6 g d-1 faster than females. Similarly, growth in bill length was faster for males, and the calculated bill size difference at fledging was similar to that observed in adults. There was no evidence for sex-based differences in growth of other morphological features. Adélie diet at Ross Island is composed almost entirely of two species—one krill (Euphausia crystallorophias) and one fish (Pleuragramma antarctica), with fish having a higher caloric value. Using isotopic analyses of feather samples, we also determined that male chicks were fed a higher proportion of fish than female chicks. The related differences in provisioning and growth rates of male and female offspring provides a greater understanding of the ways in which ecological factors may impact

  10. Efficacy of pine leaves as an alternative bedding material for broiler chicks during summer season

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    Gourav Sharma

    2015-10-01

    Full Text Available Aim: The aim was to assess the efficacy of pine leaves as an alternative bedding material on the performance of broiler chicks. Materials and Methods: The present study was conducted in summer. Total 120, day old Vencobb straight run chicks were procured, and after 5 days of brooding, chicks were randomly distributed into four treatment groups viz. paddy husk (Group I, paddy straw (Group II, pine leaves (Group III, and combination of paddy straw and pine leaves (Group IV, each having 30 chicks with 3 replicates of 10 chicks each. Chicks were reared under intensive conditions in houses that have a semi-controlled environment, with optimum temperature and adequate ventilation. Food and water were provided as per NRC (1994 requirement. Results: The average body weight after 6 weeks of the experiment was 2018.83±31.11, 1983.80±33.27, 2007.36±35.73, and 1938.43±36.35 g. The bedding type had no significant effect on the carcass characteristics viz. evisceration rate and proportion of cut-up parts of the carcass except giblet yield. The experiment suggested that performance of broiler chicks reared on paddy straw and pine leaves as litter material, had improved body weight and feed conversion ratio as compared to rearing on paddy husk as bedding material. Bacterial count, parasitic load and the N, P, K value of manure of different bedding material shows no significant difference. Conclusion: Pine leaves have a potential to be used as an alternative source of litter material to economize poultry production in a sustainable way, so as to make poultry farming as a profitable entrepreneur.

  11. Chicks incubated in hypomagnetic field need more exogenous noradrenaline for memory consolidation

    Science.gov (United States)

    Xiao, Ying; Wang, Qian; Xu, Mu-Ling; Jiang, Jin-Chang; Li, Bing

    2009-07-01

    The geomagnetic field (GMF) is one of the essential characteristics of the terrestrial environment but does not apply in outer space. The elimination of GMF may interfere with the normal activities of life in many aspects. Previous behavioral experiments have found that long-term memory is impaired in chicks incubated in a near-zero magnetic environment (i.e. hypomagnetic field or HMF). The present study was designed to evaluate the possible involvement of noradrenergic change in the functional abnormality observed before. A HMF space was produced by nullifying the natural GMF with three pairs of Helmholtz coils. The one-trial passive avoidance learning paradigm was performed on day-old chicks incubated in either the HMF space or the natural GMF. Exogenous noradrenaline was administered by intracerebral injections and the effect on memory consolidation was compared between the two categories of subjects. In the behavioral paradigm, the HMF chicks had a higher elimination rate than the GMF chicks and displayed a significant reduction in overall responsiveness. The administration of moderate doses (0.1-0.5 nmol/hemisphere) of noradrenaline led to fairly good memory retention in GMF chicks but had little effect on HMF chicks. However, long-term memory of HMF chicks could be elevated to the normal level by much higher doses (1.0-1.75 nmol/hem) of the drug. These results suggest that prolonged exposure to HMF may induce disorders in the noradrenergic system in the brain and indicate a potentiality of counteracting the ill-effect of GMF deprivation with appropriate pharmacological manipulation.

  12. Effects of Landscape-Scale Environmental Variation on Greater Sage-Grouse Chick Survival.

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    Michael R Guttery

    Full Text Available Effective long-term wildlife conservation planning for a species must be guided by information about population vital rates at multiple scales. Greater sage-grouse (Centrocercus urophasianus populations declined substantially during the twentieth century, largely as a result of habitat loss and fragmentation. In addition to the importance of conserving large tracts of suitable habitat, successful conservation of this species will require detailed information about factors affecting vital rates at both the population and range-wide scales. Research has shown that sage-grouse population growth rates are particularly sensitive to hen and chick survival rates. While considerable information on hen survival exists, there is limited information about chick survival at the population level, and currently there are no published reports of factors affecting chick survival across large spatial and temporal scales. We analyzed greater sage-grouse chick survival rates from 2 geographically distinct populations across 9 years. The effects of 3 groups of related landscape-scale covariates (climate, drought, and phenology of vegetation greenness were evaluated. Models with phenological change in greenness (NDVI performed poorly, possibly due to highly variable production of forbs and grasses being masked by sagebrush canopy. The top drought model resulted in substantial improvement in model fit relative to the base model and indicated that chick survival was negatively associated with winter drought. Our overall top model included effects of chick age, hen age, minimum temperature in May, and precipitation in July. Our results provide important insights into the possible effects of climate variability on sage-grouse chick survival.

  13. Simultaneous oral administration of Salmonella Infantis and S. Typhimurium in chicks.

    Science.gov (United States)

    Murakami, Koichi; Maeda-Mitani, Eriko; Onozuka, Daisuke; Noda, Tamie; Sera, Nobuyuki; Kimura, Hirokazu; Fujimoto, Shuji; Murakami, Satoshi

    2017-01-01

    To confirm the hypothesis that Salmonella enterica subspecies enterica serovar (S.) Infantis has higher basic reproductive rates in chicks compared with other Salmonella serovars, 1-day-old specific-pathogen-free chicks (n = 8) were challenged simultaneously with S. Infantis and S. Typhimurium per os. Challenged chicks (Group A) were then housed with non-infected chicks (Group B, n = 4) for 6 days (from 2 to 8 days of age). Group B birds were then housed with other non-infected birds (Group C, n = 4), which were then transferred to cages containing a further group of untreated chicks (Group D, n = 2). A control group consisting of four non-infected chicks was used for comparison. All chickens were humanely sacrificed at 18 days of age, and Salmonella from bowel and liver samples were enumerated. Both serovars were isolated from all groups except the control group. S. Typhimurium was isolated at a greater frequency than S. Infantis from the bowel samples of chicks from Groups B, C and D, while no differences in colonisation rates were observed between the two serovars in liver samples from Groups B, C and D. S. Typhimurium, but not S. Infantis, was immunohistochemically detected in the lamina propria of the cecum and rectum in five birds of Group A. Despite the competitive administration, neither of the two serovars completely excluded the other, and no differences were observed in basic reproductive rates between the two serovars. These findings, together with data from previous studies, suggest that the initial quantitative domination of S. Infantis in chicken flocks may explain why this serovar is predominant in broiler chickens.

  14. Effects of Landscape-Scale Environmental Variation on Greater Sage-Grouse Chick Survival.

    Science.gov (United States)

    Guttery, Michael R; Dahlgren, David K; Messmer, Terry A; Connelly, John W; Reese, Kerry P; Terletzky, Pat A; Burkepile, Nathan; Koons, David N

    2013-01-01

    Effective long-term wildlife conservation planning for a species must be guided by information about population vital rates at multiple scales. Greater sage-grouse (Centrocercus urophasianus) populations declined substantially during the twentieth century, largely as a result of habitat loss and fragmentation. In addition to the importance of conserving large tracts of suitable habitat, successful conservation of this species will require detailed information about factors affecting vital rates at both the population and range-wide scales. Research has shown that sage-grouse population growth rates are particularly sensitive to hen and chick survival rates. While considerable information on hen survival exists, there is limited information about chick survival at the population level, and currently there are no published reports of factors affecting chick survival across large spatial and temporal scales. We analyzed greater sage-grouse chick survival rates from 2 geographically distinct populations across 9 years. The effects of 3 groups of related landscape-scale covariates (climate, drought, and phenology of vegetation greenness) were evaluated. Models with phenological change in greenness (NDVI) performed poorly, possibly due to highly variable production of forbs and grasses being masked by sagebrush canopy. The top drought model resulted in substantial improvement in model fit relative to the base model and indicated that chick survival was negatively associated with winter drought. Our overall top model included effects of chick age, hen age, minimum temperature in May, and precipitation in July. Our results provide important insights into the possible effects of climate variability on sage-grouse chick survival.

  15. Sex-Based Differences in Adelie Penguin (Pygoscelis adeliae Chick Growth Rates and Diet.

    Directory of Open Access Journals (Sweden)

    Scott Jennings

    Full Text Available Sexually size-dimorphic species must show some difference between the sexes in growth rate and/or length of growing period. Such differences in growth parameters can cause the sexes to be impacted by environmental variability in different ways, and understanding these differences allows a better understanding of patterns in productivity between individuals and populations. We investigated differences in growth rate and diet between male and female Adélie Penguin (Pygoscelis adeliae chicks during two breeding seasons at Cape Crozier, Ross Island, Antarctica. Adélie Penguins are a slightly dimorphic species, with adult males averaging larger than adult females in mass (~11% as well as bill (~8% and flipper length (~3%. We measured mass and length of flipper, bill, tibiotarsus, and foot at 5-day intervals for 45 male and 40 female individually-marked chicks. Chick sex was molecularly determined from feathers. We used linear mixed effects models to estimate daily growth rate as a function of chick sex, while controlling for hatching order, brood size, year, and potential variation in breeding quality between pairs of parents. Accounting for season and hatching order, male chicks gained mass an average of 15.6 g d(-1 faster than females. Similarly, growth in bill length was faster for males, and the calculated bill size difference at fledging was similar to that observed in adults. There was no evidence for sex-based differences in growth of other morphological features. Adélie diet at Ross Island is composed almost entirely of two species--one krill (Euphausia crystallorophias and one fish (Pleuragramma antarctica, with fish having a higher caloric value. Using isotopic analyses of feather samples, we also determined that male chicks were fed a higher proportion of fish than female chicks. The related differences in provisioning and growth rates of male and female offspring provides a greater understanding of the ways in which ecological factors

  16. Premature feather loss among common tern chicks in Ontario: the return of an enigmatic developmental anomaly

    Directory of Open Access Journals (Sweden)

    Jennifer M. Arnold

    2016-05-01

    Full Text Available In July 2014, we observed premature feather loss (PFL among non-sibling, common tern Sterna hirundo chicks between two and four weeks of age at Gull Island in northern Lake Ontario, Canada. Rarely observed in wild birds, to our knowledge PFL has not been recorded in terns since 1974, despite the subsequent banding of hundreds of thousands of tern chicks across North America alone. The prevalence, 5% of chicks (9/167, and extent of feather loss we report is more extreme than in previous reports for common terns but was not accompanied by other aberrant developmental or physical deformities. Complete feather loss from all body areas (wing, tail, head and body occurred over a period of a few days but all affected chicks appeared vigorous and quickly began to grow replacement feathers. All but one chick (recovered dead and submitted for post-mortem most likely fledged 10–20 days after normal fledging age. We found no evidence of feather dystrophy or concurrent developmental abnormalities unusual among affected chicks. Thus, the PFL we observed among common terns in 2014 was largely of unknown origin. There was striking temporal association between the onset of PFL and persistent strong southwesterly winds that caused extensive mixing of near-shore surface water with cool, deep lake waters. One hypothesis is that PFL may have been caused by unidentified pathogens or toxins welling up from these deep waters along the shoreline but current data are insufficient to test this. PFL was not observed among common terns at Gull Island in 2015, although we did observe similar feather loss in a herring gull Larus argentatus chick in that year. Comparison with sporadic records of PFL in other seabirds suggests that PFL may be a rare, but non-specific, response to a range of potential stressors. PFL is now known for gulls, penguins and terns.

  17. Chick Begging Calls Reflect Degree of Hunger in Three Auk Species (Charadriiformes: Alcidae.

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    Anna V Klenova

    Full Text Available Begging behaviour is an important element in the parent-offspring conflict; it has been studied in many avian species. However, the majority of the studies have been entirely based on the call counts, and they agreed that vocal activity was a good indicator of chick's nutritional need and/or condition. Fewer researches were dedicated to the temporal-frequency variables of the begging calls themselves and they showed contrary results. Here begging behaviour in three burrow nested, uniparous species of auks (Alcidae was studied. These objects provide an opportunity to study the signalling value of begging calls in the absence of important confounding factors such as nestling competition and predation pressure. I recorded calls of individual chicks in two conditions: during natural feeding and after experimental four-hour food deprivation. I found that almost all measured acoustic variables contain information about the chick's state in all studied species. The hungry chicks produced calls higher in fundamental frequency and power variables and at higher calling rate compared to naturally feeding chicks. The effect of food deprivation on most acoustic variables exceeded both the effects of individuality and species. In all studied species, the frequency variables were stronger affected by hunger than the calling rate and call durations. I suppose that such strong change of acoustic variables after food deprivation can be explained by absence of vocal individual identification in these birds. As parents do not need to check individuality of the chick in the burrow, which they find visually during the day time, the chicks could use all of the acoustic variables to communicate about their nutritional needs.

  18. Chick Begging Calls Reflect Degree of Hunger in Three Auk Species (Charadriiformes: Alcidae).

    Science.gov (United States)

    Klenova, Anna V

    2015-01-01

    Begging behaviour is an important element in the parent-offspring conflict; it has been studied in many avian species. However, the majority of the studies have been entirely based on the call counts, and they agreed that vocal activity was a good indicator of chick's nutritional need and/or condition. Fewer researches were dedicated to the temporal-frequency variables of the begging calls themselves and they showed contrary results. Here begging behaviour in three burrow nested, uniparous species of auks (Alcidae) was studied. These objects provide an opportunity to study the signalling value of begging calls in the absence of important confounding factors such as nestling competition and predation pressure. I recorded calls of individual chicks in two conditions: during natural feeding and after experimental four-hour food deprivation. I found that almost all measured acoustic variables contain information about the chick's state in all studied species. The hungry chicks produced calls higher in fundamental frequency and power variables and at higher calling rate compared to naturally feeding chicks. The effect of food deprivation on most acoustic variables exceeded both the effects of individuality and species. In all studied species, the frequency variables were stronger affected by hunger than the calling rate and call durations. I suppose that such strong change of acoustic variables after food deprivation can be explained by absence of vocal individual identification in these birds. As parents do not need to check individuality of the chick in the burrow, which they find visually during the day time, the chicks could use all of the acoustic variables to communicate about their nutritional needs.

  19. L-Ornithine is a potential acute satiety signal in the brain of neonatal chicks.

    Science.gov (United States)

    Tran, Phuong V; Chowdhury, Vishwajit S; Do, Phong H; Bahry, Mohammad A; Yang, Hui; Furuse, Mitsuhiro

    2016-03-01

    Recently, we observed that neonatal chicks exhibit feeding behavior characterized by frequent food intake and short resting intervals, with changes detected in the brain amino acid and monoamine concentrations. In this study, we aimed to clarify further the relationship between the appetite of neonatal chicks and brain amino acid metabolism. In Experiment 1, changes were investigated in free amino acids in the brain under conditions of regulated appetite induced by fasting and subsequent short-term re-feeding. Chicks (5 days old) were distributed into four treatment groups--namely, fasting for 3h, and fasting for 3h followed by re-feeding for 10, 20 or 30 min. Brain samples were collected after treatment to analyze free amino acid concentrations. Amino adipic acid and proline in all brain parts as well as arginine and ornithine in all brain parts--except mesencephalic arginine and cerebellar ornithine--were increased in a time-dependent manner following re-feeding. In Experiment 2, we further examined the effect of exogenous administration of some amino acids altered in association with feeding behavior in Experiment 1. We chose L-arginine and its functional metabolite, L-ornithine, to analyze their effects on food intake in chicks. Intracerebroventricular injection (2 μmol) of L-ornithine, but not L-arginine, significantly inhibited food intake in neonatal chicks. In Experiment 3, we found that central injection of L-ornithine (2, 4, and 6 μmol) dose-dependently suppressed food intake in chicks. These results suggested that L-ornithine may have an important role in the control of food intake as an acute satiety signal in the neonatal chick brain.

  20. Central retinal vessel blood flow after surgical treatment for central retinal vein occlusion.

    Science.gov (United States)

    Crama, Niels; Gualino, Vincent; Restori, Marie; Charteris, David G

    2010-01-01

    The purpose of this study was to determine the effect of radial optic neurotomy and retinal endovascular surgery on retinal blood flow velocity in patients with central retinal vein occlusion. A prospective interventional case series. Six patients with a central retinal vein occlusion of retinal endovascular surgery. Five patients had decreased central venous blood flow velocity compared with the fellow eye, and one patient had similar central venous blood flow in both eyes at baseline. All study eyes had decreased central venous blood flow velocity compared with the fellow eye at 24 weeks after treatment. Two patients had a further decrease in central venous blood flow during the study. Three patients had no minimal change in central venous blood flow, and 1 patient showed a minimal increase from 3 cm/s at baseline to 4 cm/s 24 weeks after surgery. Radial optic neurotomy and retinal endovascular surgery do not alter central retinal blood flow velocity. The place of these therapies in the treatment for central retinal vein occlusion should be questioned.

  1. Ustilago maydis accumulates beta-carotene at levels determined by a retinal-forming carotenoid oxygenase.

    Science.gov (United States)

    Estrada, Alejandro F; Brefort, Thomas; Mengel, Carina; Díaz-Sánchez, Violeta; Alder, Adrian; Al-Babili, Salim; Avalos, Javier

    2009-10-01

    The basidiomycete Ustilago maydis, the causative agent of corn smut disease, has emerged as a model organism for dimorphism and fungal phytopathogenicity. In this work, we line out the key conserved enzymes for beta-carotene biosynthesis encoded by the U. maydis genome and show that this biotrophic fungus accumulates beta-carotene. The amount of this pigment depended on culture pH and aeration but was not affected by light and was not increased by oxidative stress. Moreover, we identified the U. maydis gene, cco1, encoding a putative beta-carotene cleavage oxygenase. Heterologous overexpression and in vitro analyses of purified enzyme demonstrated that Cco1 catalyzes the symmetrical cleavage of beta-carotene to yield two molecules of retinal. Analyses of beta-carotene and retinal contents in U. maydiscco1 deletion and over-expression strains confirmed the enzymatic function of Cco1, and revealed that Cco1 determines the beta-carotene content. Our data indicate that carotenoid biosynthesis in U. maydis is carried out to provide retinal rather than to deliver protective pigments. The U. maydis genome also encodes three potential opsins, a family of photoactive proteins that use retinal as chromophore. Two opsin genes showed different light-regulated expression patterns, suggesting specialized roles in photobiology, while no mRNA was detected for the third opsin gene in the same experiments. However, deletion of the cco1 gene, which should abolish function of all the retinal-dependent opsins, did not affect growth, morphology or pathogenicity, suggesting that retinal and opsin proteins play no relevant role in U. maydis under the tested conditions.

  2. Retinal oxygen saturation in relation to retinal thickness in diabetic macular edema

    DEFF Research Database (Denmark)

    Blindbæk, Søren Leer; Peto, Tunde; Grauslund, Jakob

    to retinal thickness in patients with diabetic macular edema (DME). Methods: We included 18 patients with DME that all had central retinal thickness (CRT) >300 µm and were free of active proliferative diabetic retinopathy. Optical coherence tomography (Topcon 3D OCT-2000 spectral domain OCT) was used...... for paracentral edema, the oxygen saturation in the upper and lower temporal arcade branches were compared to the corresponding upper and lower subfield thickness. Spearman’s rank was used to calculate correlation coefficients between CRT and retinal oximetry. Results: Median age and duration of diabetes was 59....... 92.3%, p=0.52). We found no correlation between CRT and retinal oxygen saturation, even when accounting for paracentral edema (p>0.05). Furthermore, there was no difference in retinal oxygen saturation between the macular hemisphere that was more or less affected by DME (p>0.05). Conclusion: Patients...

  3. Muscarinic signaling influences the patterning and phenotype of cholinergic amacrine cells in the developing chick retina

    Directory of Open Access Journals (Sweden)

    Fischer Andy J

    2008-02-01

    Full Text Available Abstract Background Many studies in the vertebrate retina have characterized the differentiation of amacrine cells as a homogenous class of neurons, but little is known about the genes and factors that regulate the development of distinct types of amacrine cells. Accordingly, the purpose of this study was to characterize the development of the cholinergic amacrine cells and identify factors that influence their development. Cholinergic amacrine cells in the embryonic chick retina were identified by using antibodies to choline acetyltransferase (ChAT. Results We found that as ChAT-immunoreactive cells differentiate they expressed the homeodomain transcription factors Pax6 and Islet1, and the cell-cycle inhibitor p27kip1. As differentiation proceeds, type-II cholinergic cells, displaced to the ganglion cell layer, transiently expressed high levels of cellular retinoic acid binding protein (CRABP and neurofilament, while type-I cells in the inner nuclear layer did not. Although there is a 1:1 ratio of type-I to type-II cells in vivo, in dissociated cell cultures the type-I cells (ChAT-positive and CRABP-negative out-numbered the type-II cells (ChAT and CRABP-positive cells by 2:1. The relative abundance of type-I to type-II cells was not influenced by Sonic Hedgehog (Shh, but was affected by compounds that act at muscarinic acetylcholine receptors. In addition, the abundance and mosaic patterning of type-II cholinergic amacrine cells is disrupted by interfering with muscarinic signaling. Conclusion We conclude that: (1 during development type-I and type-II cholinergic amacrine cells are not homotypic, (2 the phenotypic differences between these subtypes of cells is controlled by the local microenvironment, and (3 appropriate levels of muscarinic signaling between the cholinergic amacrine cells are required for proper mosaic patterning.

  4. Effects of dietary macronutrient composition on exogenous neuropeptide Y's stimulation of food intake in chicks.

    Science.gov (United States)

    Nelson, Laura A; Gilbert, Elizabeth R; Cline, Mark A

    2015-03-30

    In mammalian models it is well documented that the potent orexigenic factor, neuropeptide Y (NPY) causes preferential intake of high carbohydrate and fat diets; however, information on this is limited in non-mammalian species. The purpose of this study was to determine the influence of dietary macronutrient composition on NPY's orexigenic effect in chicks. Three isocaloric diets were formulated: high carbohydrate, fat and protein. In Experiment 1, chicks were fed the three diets and received intracerebroventricular injections of 0.2 or 2.0nmol NPY. Chicks that consumed the high carbohydrate and protein diets had a non-dose dependent similar magnitude of increased food intake after NPY injection, but those on the high fat diet had a dose dependent food intake increase. In Experiment 2, when chicks were given free access to all three diets, injection of 0.2nmol NPY caused preferential increase in intake of only the high protein diet whereas 2.0nmol NPY caused preferential increases in of both high carbohydrate and protein diets. Neither dose affected high fat diet intake. In Experiment 3, chicks were raised on one of the three diets and then switched to the others. When chicks were raised on the high fat and protein diets and then switched to the other diets, stimulation of food intake occurred for the same duration, 180min. However, when chicks were raised on the high carbohydrate and then switched to high fat, NPY injection caused a sustaining increase in cumulative food intake that lasted the entire observation period. These results suggest that NPY has selective effects on consumption of carbohydrate, fat and protein in chicks, and that diet in turn affects the NPY-mediated response in food intake, with a high fat diet enhancing NPY sensitivity that is associated with a greater magnitude and duration of feeding response. In turn, NPY caused preferential protein and carbohydrate intake instead of fat intake (in this order of preference), when chicks had the

  5. Physiological Adaptive Indicators in Fasted Neonate Broiler Chicks in Response to Calcium Gluconate Injection

    Directory of Open Access Journals (Sweden)

    Khosravinia H

    2015-06-01

    Full Text Available Four hundred and eighty mixed-sex broiler chicks aged 3 hrs after hatching were allotted according to a completely random design in a 6 × 2 × 2 factorial schedule into 2 groups of 12 replications of 20 chicks each. The main experimental factors were fasting for 0, 6, 12, 24, 36, and 48 hrs after chick placement, calcium gluconate (Ca-glu injection (0 and 0.6 mL and sex (male and female. Independent of sex, live body weight (BW of chicks decreased linearly (Y=43.36-0.109BW0h, r2=0.876 as neonatal fasting extended. Injection of 0.6 mL Ca-glu at 3 hrs post hatching did not affect weight loss of chicks. Yolk residuals (YR utilized linearly (Y=5.75-0.062YR, r2=0.956 by 0.062 g/hr in neonate fasted chicks showing no effect for Ca-glu injection. Neonatal fasting periods longer than 12 hrs increased liver weight (P. The mean absolute and proportional (% of BW0h breast and leg weight were reduced linearly as neonatal fasting extended (P. Serum glucose concentration in both sexes increased up to 6 hrs fasting, then reduced linearly to 150 mg/dL after 48 hrs feed withdrawal. The Ca-glu treatment influenced serum glucose level for a short period up to 6 hrs of fasting. Serum Ca concentration sharply increased up to three-fold in the birds received Ca-glu injection resulting in acute hypercalcemia, then decreased to the initial level after 24 hrs feed withdrawal. The mean serum level for creatinine, uric acid, cholesterol, HDL, albumins and total proteins significantly increased during the fasting periods of 6 to 48 hrs and significantly elevated in the birds received 0.6 mL Ca-glu injection compared with the non treated chicks. It was concluded that subcutaneous administration of 0.6 mL Ca-glu in the chick's neck did not suitably support the increased metabolic demands for glucose and calcium in feed deprived neonate chicks.

  6. GABA, taurine and learning: release of amino acids from slices of chick brain following filial imprinting.

    Science.gov (United States)

    McCabe, B J; Horn, G; Kendrick, K M

    2001-01-01

    The intermediate and medial hyperstriatum ventrale (IMHV) is a forebrain region in the domestic chick that is a site of information storage for the learning process of imprinting. We enquired whether imprinting is associated with learning-related increases in calcium-dependent, potassium-stimulated release of neurotransmitter amino acids from the IMHV. Chicks were hatched and reared in darkness until 15-30 h after hatching. They then either remained in darkness or were trained for 2 h by exposure to an imprinting stimulus. One hour later, the chicks were given a preference test and a preference score was calculated from the results of this test, as a measure of imprinting. Chicks were killed 2 h after training. Slices from the left and right IMHV of trained and untrained chicks were superfused with Krebs' solution either with or without calcium and the superfusate assayed for arginine, aspartate, citrulline, GABA, glutamate, glycine and taurine using high-performance liquid chromatography. For calcium-containing superfusates from the left IMHV, preference score was significantly correlated with potassium-stimulated release of (i) GABA (r=0.51, 23 d.f., P=0.008) and (ii) taurine (r=0.77, 23 d.f., Pimprinting is associated with increases in releasable pools of GABA and taurine and/or membrane excitability in the left IMHV.

  7. Hand-Rearing, Release and Survival of African Penguin Chicks Abandoned Before Independence by Moulting Parents

    Science.gov (United States)

    Sherley, Richard B.; Waller, Lauren J.; Strauss, Venessa; Geldenhuys, Deon; Underhill, Les G.; Parsons, Nola J.

    2014-01-01

    The African penguin Spheniscus demersus has an ‘Endangered’ conservation status and a decreasing population. Following abandonment, 841 African penguin chicks in 2006 and 481 in 2007 were admitted to SANCCOB (Southern African Foundation for the Conservation of Coastal Birds) for hand-rearing from colonies in the Western Cape, South Africa, after large numbers of breeding adults commenced moult with chicks still in the nest. Of those admitted, 91% and 73% respectively were released into the wild. There were veterinary concerns about avian malaria, airsacculitis and pneumonia, feather-loss and pododermatitis (bumblefoot). Post-release juvenile (0.32, s.e.  = 0.08) and adult (0.76, s.e.  = 0.10) survival rates were similar to African penguin chicks reared after oil spills and to recent survival rates recorded for naturally-reared birds. By December 2012, 12 birds had bred, six at their colony of origin, and the apparent recruitment rate was 0.11 (s.e.  = 0.03). Hand-rearing of abandoned penguin chicks is recommended as a conservation tool to limit mortality and to bolster the population at specific colonies. The feasibility of conservation translocations for the creation of new colonies for this species using hand-reared chicks warrants investigation. Any such programme would be predicated on adequate disease surveillance programmes established to minimise the risk of disease introduction to wild birds. PMID:25337698

  8. Comparison of Hensen's node and retinoic acid in secondary axis induction in the early chick embryo.

    Science.gov (United States)

    Chen, Y; Solursh, M

    1992-10-01

    Retinoic acid (RA) and Hensen's node, the organizer center in the chick embryo, have been shown to have polarizing activity when applied or grafted into the chick limb bud. Here we investigate and compare the effects of RA and grafted Hensen's node on the early chick embryo. Anion exchange beads soaked with RA at concentrations ranging from 5 to 100 ng/ml and implanted on the anterior side or on the left side of the host anteroposterior axis of a stage 4 chick embryo in ovo have the ability to induce secondary axis formation, while beads soaked with RA of the same concentration and implanted on the right side or on the posterior side of the host axis are unable to induce the secondary axis. All of the induced axes contain trunk-tail structures. Hensen's node from quail embryos implanted into the early chick blastoderm could also cause the formation of secondary axes in addition to self-differentiation of the graft into a secondary axis. Both RA and grafted Hensen's node caused the inhibition of forebrain development with an increase in hindbrain development and the host heart to loop in an abnormal direction. The results support the hypothesis that Hensen's node is a source of RA which is involved in early embryogenesis. Alternatively, RA might stimulate the formation of Hensen's nodal properties in adjacent tissue.

  9. Kidnapping of chicks in emperor penguins: a hormonal by-product?

    Science.gov (United States)

    Angelier, Frédéric; Barbraud, Christophe; Lormée, Hervé; Prud'homme, François; Chastel, Olivier

    2006-04-01

    The function and causes of kidnapping juveniles are little understood because individuals sustain some breeding costs to rear an unrelated offspring. Here we focus on the proximal causes of this behaviour in emperor penguins (Aptenodytes forsteri), whose failed breeders often kidnap chicks. We experimentally tested the hypothesis that kidnapping behaviour was the result of high residual levels of prolactin (PRL), a hormone involved in parental behaviour. Penguins with artificially decreased PRL levels by bromocriptine administration kidnapped chicks less often than control penguins. Within the bromocriptine treated group, kidnapping behaviour was not totally suppressed and the probability of kidnapping a chick was positively correlated to PRL levels measured before treatment. During breeding, emperor penguins have to forage in remote ice-free areas. In these birds, PRL secretion is poorly influenced by chick stimuli and has probably evolved to maintain a willingness to return to the colony after a long absence at sea. Therefore, penguins that have lost their chick during a foraging trip still maintain high residual PRL levels and this, combined with colonial breeding, probably facilitates kidnapping. We suggest that kidnapping in non-cooperative systems may result from a hormonal byproduct of a reproductive adaptation to extreme conditions.

  10. Hand-rearing, release and survival of African penguin chicks abandoned before independence by moulting parents.

    Science.gov (United States)

    Sherley, Richard B; Waller, Lauren J; Strauss, Venessa; Geldenhuys, Deon; Underhill, Les G; Parsons, Nola J

    2014-01-01

    The African penguin Spheniscus demersus has an 'Endangered' conservation status and a decreasing population. Following abandonment, 841 African penguin chicks in 2006 and 481 in 2007 were admitted to SANCCOB (Southern African Foundation for the Conservation of Coastal Birds) for hand-rearing from colonies in the Western Cape, South Africa, after large numbers of breeding adults commenced moult with chicks still in the nest. Of those admitted, 91% and 73% respectively were released into the wild. There were veterinary concerns about avian malaria, airsacculitis and pneumonia, feather-loss and pododermatitis (bumblefoot). Post-release juvenile (0.32, s.e.  = 0.08) and adult (0.76, s.e.  = 0.10) survival rates were similar to African penguin chicks reared after oil spills and to recent survival rates recorded for naturally-reared birds. By December 2012, 12 birds had bred, six at their colony of origin, and the apparent recruitment rate was 0.11 (s.e.  = 0.03). Hand-rearing of abandoned penguin chicks is recommended as a conservation tool to limit mortality and to bolster the population at specific colonies. The feasibility of conservation translocations for the creation of new colonies for this species using hand-reared chicks warrants investigation. Any such programme would be predicated on adequate disease surveillance programmes established to minimise the risk of disease introduction to wild birds.

  11. Pharmacological reversal of cognitive bias in the chick anxiety-depression model.

    Science.gov (United States)

    Hymel, Kristen A; Sufka, Kenneth J

    2012-01-01

    Cognitive bias presents in clinical populations where anxious individuals adopt a more pessimistic interpretation of ambiguous aversive stimuli and depressed individuals adopt both a more pessimistic interpretation of ambiguous aversive stimuli and a less optimistic interpretation of ambiguous appetitive stimuli. These biases have been reversed by anxiolytics and antidepressants. In the current study, chicks exposed to an isolation stressor of 5-min to induce an anxiety-like state or 60-min to induce a depressive-like state were tested in a straight alley maze to a series of morphed ambiguous appetitive (chick silhouette) to aversive (owl silhouette) cues. Chicks in the depression-like state displayed more pessimistic-like and less optimistic-like approach behavior to ambiguous aversive and appetitive cues, respectively. Both forms of cognitive bias were reversed by 15.0 mg/kg imipramine. Chicks in anxiety-like st