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Sample records for eye migration pigmentation

  1. Calcium binding in pigmented and albino eyes.

    PubMed Central

    Dräger, U C

    1985-01-01

    The localization of calcium binding sites in eyes was determined autoradiographically after extracting endogenous Ca from tissue sections and replacing it with 45Ca. The strongest labeling was associated with pigmented tissues due to the high concentration of melanin, which was shown to bind Ca effectively and in a pH-dependent fashion. The second strongest binding was over the tapetum lucidum of the cat eye, and moderate labeling was associated with eye muscles and epithelium and endothelium of the cornea. The neural retina was generally more lightly labeled than the surrounding tissue of the eye; here the plexiform layers stood out in comparison to the nuclear layers, as did a band located internal to the photoreceptor outer segments. The possibility that the Ca buffering capacity of melanin may represent the common denominator for the various neurological defects found in hypopigmentation mutants is discussed. Images PMID:3863122

  2. Epithelia-mesenchyme interaction plays an essential role in transdifferentiation of retinal pigment epithelium of silver mutant quail: localization of FGF and related molecules and aberrant migration pattern of neural crest cells during eye rudiment formation.

    PubMed

    Araki, Masasuke; Takano, Takako; Uemonsa, Tomoko; Nakane, Yoshifumi; Tsudzuki, Masaoki; Kaneko, Tomoko

    2002-04-15

    Homozygotes of the quail silver mutation, which have plumage color changes, also display a unique phenotype in the eye: during early embryonic development, the retinal pigment epithelium (RPE) spontaneously transdifferentiates into neural retinal tissue. Mitf is considered to be the responsible gene and to function similarly to the mouse microphthalmia mutation, and tissue interaction between RPE and surrounding mesenchymal tissue in organ culture has been shown to be essential for the initiation of the transdifferentiation process in which fibroblast growth factor (FGF) signaling is involved. The immunohistochemical results of the present study show that laminin and heparan sulfate proteoglycan, both acting as cofactors for FGF binding, are localized in the area of transdifferentiation of silver embryos much more abundantly than in wild-type embryos. More intense immunohistochemical staining with FGF-1 antibody, but not with FGF-2 antibody, is also found in the neural retina, RPE, and choroidal tissue of silver embryos than in wild-type embryos. HNK-1 immunohistochemistry revealed that clusters of HNK-1-positive cells (presumptive migrating neural crest cells) are frequently located around the developing eyes and in the posterior region of the silver embryonic eye. Finally, chick-quail chimerical eyes were made by grafting silver quail optic vesicles to chicken host embryos: in most cases, no transdifferentiation occurs in the silver RPE, but in a few cases, transdifferentiation occurs where silver quail cells predominate in the choroid tissue. These observations together with our previous in vitro study indicate that the silver mutation affects not only RPE cells but also cephalic neural crest cells, which migrate to the eye rudiment, and that these crest cells play an essential role in the transdifferentiation of RPE, possibly by modifying the FGF signaling pathway. The precise molecular mechanism involved in RPE-neural crest cell interaction is still unknown

  3. Primary adenocarcinoma of pigmented ciliary epithelium in a phthisical eye.

    PubMed

    Kumar, Jaya B; Proia, Alan D; Mruthyunjaya, Prithvi; Sharma, Sumit

    2016-01-01

    We report a case of adenocarcinoma of the pigmented ciliary epithelium arising in a phthisical eye. A 92-year-old man who initially presented with severe ocular pain had calcification extending from the posterior pole to ciliary body on B-scan ultrasonography to a degree not previously reported. We highlight the importance of screening for intraocular neoplasms in adults with a long-standing phthisical eye. PMID:26597037

  4. Eye pigments of the blood-sucking insect, Triatoma infestans Klug (Hemiptera, Reduviidae).

    PubMed

    Moraes, A S; Pimentel, E R; Rodrigues, V L C C; Mello, M L S

    2005-08-01

    The pigmentation of black (wild) and red (mutant) eyes of Triatoma infestans was studied spectrophotometrically and compared with red-eyed (wild) and white-eyed (mutant) forms of Drosophila melanogaster. The spectral absorption profiles of the black and red eye pigments of T. infestans were similar to each other and to that of the wild-type eyes of D. melanogaster. The similarity to the wild form of D. melanogaster indicated that both eye forms of T. infestans contained ommochromes of the xanthommatin type, a finding confirmed by ascending paper chromatography. Pteridines, melanins, and ommins were not detected as eye pigments in T. infestans. The eye color difference in T. infestans was assumed to be a function of the xanthommatin concentration, with a smaller content of ommochrome in red eyes, although this probably did not affect the insect's visual acuity. These data support other findings regarding the similarities between black- and red-eyed specimens of T. infestans for other characteristics. PMID:16341426

  5. Oxidative stress, photodamage and the role of screening pigments in insect eyes.

    PubMed

    Insausti, Teresita C; Le Gall, Marion; Lazzari, Claudio R

    2013-09-01

    Using red-eyed mutant triatomine bugs (Hemiptera: Reduvidae), we tested the hypothesis of an alternative function of insect screening pigments against oxidative stress. To test our hypothesis, we studied the morphological and physiological changes associated with the mutation. We found that wild-type eyes possess a great amount of brown and red screening pigment inside the primary and secondary pigment cells as well as in the retinular cells. Red-eyed mutants, however, have only scarce red granules inside the pigmentary cells. We then compared the visual sensitivity of red-eyed mutants and wild types by measuring the photonegative responses of insects reared in light:dark cycles [12 h:12 h light:dark (LD)] or constant darkness (DD). Finally, we analyzed both the impact of oxidative stress associated with blood ingestion and photodamage of UV light on the eye retina. We found that red-eyed mutants reared in DD conditions were the most sensitive to the light intensities tested. Retinae of LD-reared mutants were gradually damaged over the life cycle, while for DD-reared insects retinae were conserved intact. No retinal damage was observed in non-fed mutants exposed to UV light for 2 weeks, whereas insects fed on blood prior to UV exposure showed clear signs of retinal damage. Wild-type insects exposed to UV light showed a marked increase in the amount and density of screening pigments. PMID:23661779

  6. Technical note: Digital quantification of eye pigmentation of cattle with white faces.

    PubMed

    Davis, K M; Smith, T; Bolt, B; Meadows, S; Powell, J G; Vann, R C; Arthington, J D; DiLorenzo, N; Lalman, D L; Rouquette, F M; Hansen, G R; Cooper, A J; Cloud, J E; Garcia, M D; Herring, A D; Hale, D S; Sanders, J O; Hairgrove, T B; DeWitt, T J; Riley, D G

    2015-07-01

    Cancer of the eye in cattle with white faces occurs less frequently in cattle with pigmented eyelids. Corneoscleral pigmentation is related to eyelid pigmentation and occurrence of lesions that may precede cancer. Objectives of this study were to assess 1) variation in the proportion of eyelid and corneoscleral pigmentation in Hereford, Bos taurus, and Bos indicus crossbreds and 2) the occurrence of lesions with the presence of pigmentation in those areas. Hereford and Bos indicus crosses (Brahman or Nellore with Angus and Hereford and straightbred Brafords) and Bos taurus crosses (Angus-Hereford) were included in the study (n = 1,083). Eyelid pigmentation proportions were estimated by pixel quantification and were evaluated as total proportions and for upper and lower eyelids distinctly for each eye. Fixed effects included breed type, age categories, and sex of the animal. Lesion presence (1) or absence (0) was obtained by visual appraisal of image and was assumed to be binomially distributed. Eyelid pigmentation proportions (overall, upper, and lower eyelids) for Hereford ranged from 0.65 ± 0.03 to 0.68 ± 0.03 and were significantly lower than Bos indicus (range from 0.93 ± 0.02 to 0.95 ± 0.02) or Bos taurus (ranged from 0.88 ± 0.02 to 0.92 ± 0.02) crosses. Corneoscleral pigmentation in Hereford cows (0.17 ± 0.06) did not differ (P = 0.91) from Hereford calves and yearlings (0.16 ± 0.07). Bos indicus and Bos taurus crossbred cows had larger corneoscleral pigmentation (0.38 ± 0.05 and 0.48 ± 0.04 for left eyes and 0.37 ± 0.05 and 0.53 ± 0.04 for right eyes, respectively) than all calves (P < 0.001), and their corneoscleral pigmentations were greater than that of Hereford cows (P < 0.003). Bos indicus and Bos taurus cows had greater proportions of left eye corneoscleral pigmentation (0.38 ± 0.05 and 0.48 ± 0.04, respectively) than Hereford cows (0.17 ± 0.06) and all young animal breed types (P < 0.05). Right eye proportions differed for all cow

  7. Clonal origins of cells in the pigmented retina of the zebrafish eye

    SciTech Connect

    Streisinger, G.; Coale, F.; Taggart, C.; Walker, C.; Grunwald, D.J.

    1989-01-01

    Mosaic analysis has been used to study the clonal basis of the development of the pigmented retina of the zebrafish, Brachydanio rerio. Zebrafish embryos heterozygous for a recessive mutation at the gol-1 locus were exposed to gamma-irradiation at various developmental stages to create mosaic individuals consisting of wild-type pigmented cells and a clone of pigmentless (golden) cells in the eye. The contribution of individual embryonic cells to the pigmented retina was measured and the total number of cells in the embryo that contributed descendants to this tissue was determined. Until the 32-cell stage, almost every blastomere has some descendants that participate in the formation of the pigmented retina of the zebrafish. During subsequent cell divisions, up to the several thousand-cell stage, the number of ancestral cells is constant: approximately 40 cells are present that will give rise to progeny in the pigmented retina. Analysis of the size of clones in the pigmented retina indicates that the cells of this tissue do not arise through a rigid series of cell divisions originating in the early embryo. The findings that each cleavage stage cell contributes to the pigmented retina and yet the contribution of such cells is highly variable are consistent with the interpretation that clonal descendants of different blastomeres normally intermix extensively prior to formation of the pigmented retina.

  8. Nitisinone improves eye and skin pigmentation defects in a mouse model of oculocutaneous albinism.

    PubMed

    Onojafe, Ighovie F; Adams, David R; Simeonov, Dimitre R; Zhang, Jun; Chan, Chi-Chao; Bernardini, Isa M; Sergeev, Yuri V; Dolinska, Monika B; Alur, Ramakrishna P; Brilliant, Murray H; Gahl, William A; Brooks, Brian P

    2011-10-01

    Mutation of the tyrosinase gene (TYR) causes oculocutaneous albinism, type 1 (OCA1), a condition characterized by reduced skin and eye melanin pigmentation and by vision loss. The retinal pigment epithelium influences postnatal visual development. Therefore, increasing ocular pigmentation in patients with OCA1 might enhance visual function. There are 2 forms of OCA1, OCA-1A and OCA-1B. Individuals with the former lack functional tyrosinase and therefore lack melanin, while individuals with the latter produce some melanin. We hypothesized that increasing plasma tyrosine concentrations using nitisinone, an FDA-approved inhibitor of tyrosine degradation, could stabilize tyrosinase and improve pigmentation in individuals with OCA1. Here, we tested this hypothesis in mice homozygous for either the Tyrc-2J null allele or the Tyrc-h allele, which model OCA-1A and OCA-1B, respectively. Only nitisinone-treated Tyrc-h/c-h mice manifested increased pigmentation in their fur and irides and had more pigmented melanosomes. High levels of tyrosine improved the stability and enzymatic function of the Tyrc-h protein and also increased overall melanin levels in melanocytes from a human with OCA-1B. These results suggest that the use of nitisinone in OCA-1B patients could improve their pigmentation and potentially ameliorate vision loss. PMID:21968110

  9. Pigmented anatomy in Carboniferous cyclostomes and the evolution of the vertebrate eye.

    PubMed

    Gabbott, Sarah E; Donoghue, Philip C J; Sansom, Robert S; Vinther, Jakob; Dolocan, Andrei; Purnell, Mark A

    2016-08-17

    The success of vertebrates is linked to the evolution of a camera-style eye and sophisticated visual system. In the absence of useful data from fossils, scenarios for evolutionary assembly of the vertebrate eye have been based necessarily on evidence from development, molecular genetics and comparative anatomy in living vertebrates. Unfortunately, steps in the transition from a light-sensitive 'eye spot' in invertebrate chordates to an image-forming camera-style eye in jawed vertebrates are constrained only by hagfish and lampreys (cyclostomes), which are interpreted to reflect either an intermediate or degenerate condition. Here, we report-based on evidence of size, shape, preservation mode and localized occurrence-the presence of melanosomes (pigment-bearing organelles) in fossil cyclostome eyes. Time of flight secondary ion mass spectrometry analyses reveal secondary ions with a relative intensity characteristic of melanin as revealed through principal components analyses. Our data support the hypotheses that extant hagfish eyes are degenerate, not rudimentary, that cyclostomes are monophyletic, and that the ancestral vertebrate had a functional visual system. We also demonstrate integument pigmentation in fossil lampreys, opening up the exciting possibility of investigating colour patterning in Palaeozoic vertebrates. The examples we report add to the record of melanosome preservation in Carboniferous fossils and attest to surprising durability of melanosomes and biomolecular melanin. PMID:27488650

  10. Pigmented anatomy in Carboniferous cyclostomes and the evolution of the vertebrate eye

    PubMed Central

    Gabbott, Sarah E.; Sansom, Robert S.; Vinther, Jakob; Dolocan, Andrei; Purnell, Mark A.

    2016-01-01

    The success of vertebrates is linked to the evolution of a camera-style eye and sophisticated visual system. In the absence of useful data from fossils, scenarios for evolutionary assembly of the vertebrate eye have been based necessarily on evidence from development, molecular genetics and comparative anatomy in living vertebrates. Unfortunately, steps in the transition from a light-sensitive ‘eye spot’ in invertebrate chordates to an image-forming camera-style eye in jawed vertebrates are constrained only by hagfish and lampreys (cyclostomes), which are interpreted to reflect either an intermediate or degenerate condition. Here, we report—based on evidence of size, shape, preservation mode and localized occurrence—the presence of melanosomes (pigment-bearing organelles) in fossil cyclostome eyes. Time of flight secondary ion mass spectrometry analyses reveal secondary ions with a relative intensity characteristic of melanin as revealed through principal components analyses. Our data support the hypotheses that extant hagfish eyes are degenerate, not rudimentary, that cyclostomes are monophyletic, and that the ancestral vertebrate had a functional visual system. We also demonstrate integument pigmentation in fossil lampreys, opening up the exciting possibility of investigating colour patterning in Palaeozoic vertebrates. The examples we report add to the record of melanosome preservation in Carboniferous fossils and attest to surprising durability of melanosomes and biomolecular melanin. PMID:27488650

  11. Dissection of a Mouse Eye for a Whole Mount of the Retinal Pigment Epithelium

    PubMed Central

    Claybon, Alison; Bishop, Alexander J. R.

    2011-01-01

    The retinal pigment epithelium (RPE) lies at the back of the mammalian eye, just under the neural retina, which contains the photoreceptors (rods and cones). The RPE is a monolayer of pigmented cuboidal cells and associates closely with the neural retina just above it. This association makes the RPE of great interest to researchers studying retinal diseases. The RPE is also the site of an in vivo assay of homology-directed DNA repair, the pun assay. The mouse eye is particularly difficult to dissect due to its small size (about 3.5mm in diameter) and its spherical shape. This article demonstrates in detail a procedure for dissection of the eye resulting in a whole mount of the RPE. In this procedure, we show how to work with, rather than against, the spherical structure of the eye. Briefly, the connective tissue, muscle, and optic nerve are removed from the back of the eye. Then, the cornea and lens are removed. Next, strategic cuts are made that result in significant flattening of the remaining tissue. Finally, the neural retina is gently lifted off, revealing an intact RPE, which is still attached to the underlying choroid and sclera. This whole mount can be used to perform the punassay or for immunohistochemistry or immunofluorescent assessment of the RPE tissue. PMID:21403630

  12. The control of pigment migration in isolated erythrophores of Holocentrus ascensionis (Osbeck). I. Energy requirements.

    PubMed

    Luby, K J; Porter, K R

    1980-08-01

    Erythrophores isolated from the scales of the marine teleost, Holocentrus ascensionis (Osbeck), are capable of rapidly aggregating or dispersing numberous red pigment granules within their cytoplasm by translocating them along radial paths delineated by bundles of radially oriented microtubules. Pigment translocation is accompanied by transformations in the morphology of the cytoplasmic matrix, or microtrabecular lattice (MTL), in which the pigment granules are suspended. It appears that the MTL as a whole contracts toward the cell center during aggregation, carrying the pigment granules inward along with it, and is restructured during dispersion, using the radial microtubules as guides. We examined the energy requirements of pigment migration and the accompanying MTL transformations. Cellular ATP was depleted using the specific metabolic inhibitors 2,4 dinitrophenol, NaCN and oligomycin. All three of these drugs, which inhibit oxidative phosphorylation by different mechanisms, prevent both pigment dispersion and MTL transformation to dispersed morphology, while aggregation is unaffected. Inhibitor-treated cells recover normal pigment movements and MTL morphology when inhibitor is washed out of the cells with fresh medium. Potential energy apparently is stored in the MTL by some ATP-dependent process during dispersion and is converted to kinetic energy during aggregation. The results of this study strengthen the hypothesis that the MTL, working in concert with the radial microtubules, is the vehicle for pigment translocation in the erythrophore system. PMID:7407908

  13. Absorption of the eye lens and macular pigment derived from the reflectance of cone photoreceptors

    NASA Astrophysics Data System (ADS)

    Zagers, Niels P. A.; van Norren, Dirk

    2004-12-01

    We measured the amplitude of the directional component of the bleached fundus reflectance, the so-called optical Stiles-Crawford effect, as a function of wavelength. The directional reflectance originates from within the outer segments of the photoreceptors. Thus only two anterior absorbers are of importance: macular pigment and the crystalline lens. Analysis of spectra obtained in pseudophakes established that the cone photoreceptors act as spectrally neutral reflectors. The reflectance spectra, expressed in density units, resembled the macular pigment density spectrum. Studying age effects in the lens of normal subjects resulted in a description of the optical density of the lens in terms of a ``young'' and an ``aged'' template. The young template represents the pigment O-β-glucoside of 3-hydroxykynurenine, which dominates the light absorption in young eyes and decreases with age. The aged template represents the pigments accumulating in the lens with age. The total optical density increased with age, but it was lower in the wavelength region 500-650 nm than was previously assumed on the basis of psychophysical studies. Analysis of the spectra also provided precise individual estimates of the optical density of macular pigment. Finally, we observed a decrease in the photoreceptor reflectivity with age, possibly reflecting a degradation of the photoreceptors.

  14. Genome-wide association studies of quantitatively measured skin, hair, and eye pigmentation in four European populations.

    PubMed

    Candille, Sophie I; Absher, Devin M; Beleza, Sandra; Bauchet, Marc; McEvoy, Brian; Garrison, Nanibaa' A; Li, Jun Z; Myers, Richard M; Barsh, Gregory S; Tang, Hua; Shriver, Mark D

    2012-01-01

    Pigmentation of the skin, hair, and eyes varies both within and between human populations. Identifying the genes and alleles underlying this variation has been the goal of many candidate gene and several genome-wide association studies (GWAS). Most GWAS for pigmentary traits to date have been based on subjective phenotypes using categorical scales. But skin, hair, and eye pigmentation vary continuously. Here, we seek to characterize quantitative variation in these traits objectively and accurately and to determine their genetic basis. Objective and quantitative measures of skin, hair, and eye color were made using reflectance or digital spectroscopy in Europeans from Ireland, Poland, Italy, and Portugal. A GWAS was conducted for the three quantitative pigmentation phenotypes in 176 women across 313,763 SNP loci, and replication of the most significant associations was attempted in a sample of 294 European men and women from the same countries. We find that the pigmentation phenotypes are highly stratified along axes of European genetic differentiation. The country of sampling explains approximately 35% of the variation in skin pigmentation, 31% of the variation in hair pigmentation, and 40% of the variation in eye pigmentation. All three quantitative phenotypes are correlated with each other. In our two-stage association study, we reproduce the association of rs1667394 at the OCA2/HERC2 locus with eye color but we do not identify new genetic determinants of skin and hair pigmentation supporting the lack of major genes affecting skin and hair color variation within Europe and suggesting that not only careful phenotyping but also larger cohorts are required to understand the genetic architecture of these complex quantitative traits. Interestingly, we also see that in each of these four populations, men are more lightly pigmented in the unexposed skin of the inner arm than women, a fact that is underappreciated and may vary across the world. PMID:23118974

  15. Subretinal delivery and electroporation in pigmented and nonpigmented adult mouse eyes

    PubMed Central

    Nickerson, John M.; Goodman, Penny; Chrenek, Micah A.; Johnson, Christiana J.; Berglin, Lennart; Redmond, T. Michael.; Boatright, Jeffrey H.

    2013-01-01

    Subretinal injection offers one of the best ways to deliver many classes of drugs, reagents, cells and treatments to the photoreceptor, Müller, and retinal pigment epithelium (RPE) cells of the retina. Agents delivered to this space are placed within microns of the intended target cell, accumulating to high concentrations because there is no dilution due to transport processes or diffusion. Dilution in the interphotoreceptor space (IPS) is minimal because the IPS volume is only 10-20 microliters in the human eye and less than 1 microliter in the mouse eye. For gene delivery purposes, we wished to transfect the cells adjacent to the IPS in adult mouse eyes. Others transfect these cells in neonatal rats to study the development of the retina. In both neonates and adults, electroporation is found to be effective Here we describe the optimization of electroporation conditions for RPE cells in the adult mouse eye with naked plasmids. However, both techniques, subretinal injection and electroporation, present some technical challenges that require skill on the part of the surgeon to prevent untoward damage to the eye. Here we describe methods that we have used for the past ten years (1). PMID:22688698

  16. Synthesis and migration of /sup 3/H-fucose-labeled glycoproteins in the retinal pigment epithelium of albino rats, as visualized by radioautography

    SciTech Connect

    Haddad, A.; Bennett, G.

    1987-03-01

    /sup 3/H-fucose was injected into the vitreous body of the eye(s) of 250-gm rats, which were then killed by means of an intracardiac perfusion with glutaraldehyde after intervals of 10 min, 1 and 4 hr, and 1 and 7 days. The eyes were removed and further fixed, and pieces of retina were processed for light and electron microscope radioautography. Light microscope radioautography showed that the pigment epithelial cells actively incorporated /sup 3/H-fucose label. The intensity of reaction peaked at 4 hr after injection of the label and then slowly declined. Quantitative electron microscope radioautography revealed that, at 10 min after /sup 3/H-fucose injection, over 70% of the label was localized to the Golgi apparatus, indicating that fucose residues are added to newly synthesized glycoproteins principally at this site. With time the proportion of label associated with the Golgi apparatus decreased, but that assigned to the infolded basal plasma membrane, the apical microvilli, and various apical lysosomes increased. These results indicate that in retinal pigment epithelial cells newly synthesized glycoproteins continuously migrate from the Golgi apparatus to lysosomes and to various regions of the plasma membrane. In this case, the membrane glycoproteins may play specific roles in receptor functions of the basal plasma membrane or phagocytic activities at the apical surface. Very little label migrated to Bruch's membrane, indicating either a very slow turnover or a paucity of fucose-containing glycoproteins at this site.

  17. Melanosomes in pigmented epithelia maintain eye lens transparency during zebrafish embryonic development.

    PubMed

    Takamiya, Masanari; Xu, Feng; Suhonen, Heikki; Gourain, Victor; Yang, Lixin; Ho, Nga Yu; Helfen, Lukas; Schröck, Anne; Etard, Christelle; Grabher, Clemens; Rastegar, Sepand; Schlunck, Günther; Reinhard, Thomas; Baumbach, Tilo; Strähle, Uwe

    2016-01-01

    Altered levels of trace elements are associated with increased oxidative stress that is eventually responsible for pathologic conditions. Oxidative stress has been proposed to be involved in eye diseases, including cataract formation. We visualized the distribution of metals and other trace elements in the eye of zebrafish embryos by micro X-ray fluorescence (μ-XRF) imaging. Many elements showed highest accumulation in the retinal pigment epithelium (RPE) of the zebrafish embryo. Knockdown of the zebrafish brown locus homologues tyrp1a/b eliminated accumulation of these elements in the RPE, indicating that they are bound by mature melanosomes. Furthermore, albino (slc45a2) mutants, which completely lack melanosomes, developed abnormal lens reflections similar to the congenital cataract caused by mutation of the myosin chaperon Unc45b, and an in situ spin trapping assay revealed increased oxidative stress in the lens of albino mutants. Finally transplanting a wildtype lens into an albino mutant background resulted in cataract formation. These data suggest that melanosomes in pigment epithelial cells protect the lens from oxidative stress during embryonic development, likely by buffering trace elements. PMID:27141993

  18. Melanosomes in pigmented epithelia maintain eye lens transparency during zebrafish embryonic development

    PubMed Central

    Takamiya, Masanari; Xu, Feng; Suhonen, Heikki; Gourain, Victor; Yang, Lixin; Ho, Nga Yu; Helfen, Lukas; Schröck, Anne; Etard, Christelle; Grabher, Clemens; Rastegar, Sepand; Schlunck, Günther; Reinhard, Thomas; Baumbach, Tilo; Strähle, Uwe

    2016-01-01

    Altered levels of trace elements are associated with increased oxidative stress that is eventually responsible for pathologic conditions. Oxidative stress has been proposed to be involved in eye diseases, including cataract formation. We visualized the distribution of metals and other trace elements in the eye of zebrafish embryos by micro X-ray fluorescence (μ-XRF) imaging. Many elements showed highest accumulation in the retinal pigment epithelium (RPE) of the zebrafish embryo. Knockdown of the zebrafish brown locus homologues tyrp1a/b eliminated accumulation of these elements in the RPE, indicating that they are bound by mature melanosomes. Furthermore, albino (slc45a2) mutants, which completely lack melanosomes, developed abnormal lens reflections similar to the congenital cataract caused by mutation of the myosin chaperon Unc45b, and an in situ spin trapping assay revealed increased oxidative stress in the lens of albino mutants. Finally transplanting a wildtype lens into an albino mutant background resulted in cataract formation. These data suggest that melanosomes in pigment epithelial cells protect the lens from oxidative stress during embryonic development, likely by buffering trace elements. PMID:27141993

  19. Drosophila Eyes Absent Is Required for Normal Cone and Pigment Cell Development

    PubMed Central

    Karandikar, Umesh C.; Jin, Meng; Jusiak, Barbara; Kwak, SuJin; Chen, Rui; Mardon, Graeme

    2014-01-01

    In Drosophila, development of the compound eye is orchestrated by a network of highly conserved transcriptional regulators known as the retinal determination (RD) network. The retinal determination gene eyes absent (eya) is expressed in most cells within the developing eye field, from undifferentiated retinal progenitors to photoreceptor cells whose differentiation begins at the morphogenetic furrow (MF). Loss of eya expression leads to an early block in retinal development, making it impossible to study the role of eya expression during later steps of retinal differentiation. We have identified two new regulatory regions that control eya expression during retinal development. These two enhancers are necessary to maintain eya expression anterior to the MF (eya-IAM) and in photoreceptors (eya-PSE), respectively. We find that deleting these enhancers affects developmental events anterior to the MF as well as retinal differentiation posterior to the MF. In line with previous results, we find that reducing eya expression anterior to the MF affects several early steps during early retinal differentiation, including cell cycle arrest and expression of the proneural gene ato. Consistent with previous observations that suggest a role for eya in cell proliferation during early development we find that deletion of eya-IAM leads to a marked reduction in the size of the adult retinal field. On the other hand, deletion of eya-PSE leads to defects in cone and pigment cell development. In addition we find that eya expression is necessary to activate expression of the cone cell marker Cut and to regulate levels of the Hedgehog pathway effector Ci. In summary, our study uncovers novel aspects of eya-mediated regulation of eye development. The genetic tools generated in this study will allow for a detailed study of how the RD network regulates key steps in eye formation. PMID:25057928

  20. Expression of pigment epithelium‐derived factor and thrombospondin‐1 regulate proliferation and migration of retinal pigment epithelial cells

    PubMed Central

    Farnoodian, Mitra; Kinter, James B.; Yadranji Aghdam, Saeed; Zaitoun, Ismail; Sorenson, Christine M.; Sheibani, Nader

    2015-01-01

    Abstract Age‐related macular degeneration (AMD) is the leading cause of vision loss among elderly. Although the pathogenesis of AMD is associated with retinal pigmented epithelium (RPE) dysfunction and abnormal neovascularization the detailed mechanisms remain unresolved. RPE is a specialized monolayer of epithelial cells with important functions in ocular homeostasis. Pathological RPE damage contributes to major ocular conditions including retinal degeneration and irreversible loss of vision in AMD. RPE cells also assist in the maintenance of the ocular angiogenic balance by production of positive and negative regulatory factors including vascular endothelial growth factor (VEGF), thrombospondin‐1 (TSP1), and pigment epithelium‐derived factor (PEDF). The altered production of PEDF and TSP1, as endogenous inhibitors of angiogenesis and inflammation, by RPE cells have been linked to pathogenesis of AMD and choroidal and retinal neovascularization. However, lack of simple methods for isolation and culture of mouse RPE cells has resulted in limited knowledge regarding the cell autonomous role of TSP1 and PEDF in RPE cell function. Here, we describe a method for routine isolation and propagation of RPE cells from wild‐type, TSP1, and PEDF‐deficient mice, and have investigated their impact on RPE cell function. We showed that expression of TSP1 and PEDF significantly impacted RPE cell proliferation, migration, adhesion, oxidative state, and phagocytic activity with minimal effect on their basal rate of apoptosis. Together, our results indicated that the expression of PEDF and TSP1 by RPE cells play crucial roles not only in regulation of ocular vascular homeostasis but also have significant impact on their cellular function. PMID:25602019

  1. The retinal pigment epithelium as a gateway for monocyte trafficking into the eye.

    PubMed

    Benhar, Inbal; Reemst, Kitty; Kalchenko, Vyacheslav; Schwartz, Michal

    2016-06-01

    The choroid plexus epithelium within the brain ventricles orchestrates blood-derived monocyte entry to the central nervous system under injurious conditions, including when the primary injury site is remote from the brain. Here, we hypothesized that the retinal pigment epithelium (RPE) serves a parallel role, as a gateway for monocyte trafficking to the retina following direct or remote injury. We found elevated expression of genes encoding leukocyte trafficking determinants in mouse RPE as a consequence of retinal glutamate intoxication or optic nerve crush (ONC). Blocking VCAM-1 after ONC interfered with monocyte infiltration into the retina and resulted in a local pro-inflammatory cytokine bias. Live imaging of the injured eye showed monocyte accumulation first in the RPE, and subsequently in the retina, and peripheral leukocytes formed close contact with the RPE Our findings further implied that the ocular milieu can confer monocytes a phenotype advantageous for neuroprotection. These results suggest that the eye utilizes a mechanism of crosstalk with the immune system similar to that of the brain, whereby epithelial barriers serve as gateways for leukocyte entry. PMID:27107049

  2. High dietary arachidonic acid levels affect the process of eye migration and head shape in pseudoalbino Senegalese sole Solea senegalensis early juveniles.

    PubMed

    Boglino, A; Wishkerman, A; Darias, M J; Andree, K B; de la Iglesia, P; Estévez, A; Gisbert, E

    2013-11-01

    The effect of high dietary levels of arachidonic acid (ARA) on the eye migration and cranial bone remodelling processes in Senegalese sole Solea senegalensis early juveniles (age: 50 days post hatch) was evaluated by means of geometric morphometric analysis and alizarin red staining of cranial skeletal elements. The incidence of normally pigmented fish fed the control diet was 99·1 ± 0·3% (mean ± s.e.), whereas it was only 18·7 ± 7·5% for those fed high levels of ARA (ARA-H). The frequency of cranial deformities was significantly higher in fish fed ARA-H (95·1 ± 1·5%) than in those fed the control diet (1·9 ± 1·9%). Cranial deformities were significantly and negatively correlated with the incidence of normally pigmented animals (r² = -0·88, P < 0·001, n = 16). Thus, fish displaying pigmentary disorders differed in the position of their eyes with regard to the vertebral column and mouth axes, and by the interocular distance and head height, which were shorter than in fish not displaying pigmentary disorders. In addition to changes in the positioning of both eyes, pseudoalbino fish showed some ARA-induced osteological differences for some of the skeletal elements from the splanchnocranium (e.g. right premaxillary, dentary, angular, lacrimal, ceratohyal and branchiostegal rays) and neurocranium (e.g. sphenotic, left lateral ethmoid and left frontal) by comparison to normally pigmented specimens. Pseudoalbino fish also had teeth in both lower and upper jaws. This is the first study in Pleuronectiformes that describes impaired metamorphic relocation of the ocular side eye, the right eye in the case of S. senegalensis, whereas the left eye migrated into the ocular side almost normally. PMID:24580667

  3. The genetics of skin, hair, and eye color variation and its relevance to forensic pigmentation predictive tests.

    PubMed

    Maroñas, O; Söchtig, J; Ruiz, Y; Phillips, C; Carracedo, Á; Lareu, M V

    2015-01-01

    This review examines the potential application of single nucleotide polymorphism (SNP)-based predictive tests for skin, hair, and eye color to forensic analysis in support of police investigations lacking DNA database matches or eyewitness testimony. Brief descriptions of the biology of melanogenesis and the main genes involved are presented in order to understand the basis of common pigmentation variation in humans. We outline the most recently developed forensically sensitive multiplex tests that can be applied to investigative analyses. The review also describes the biology of the SNPs with the closest associations to, and therefore the best predictors for, common variation in eye, hair, and skin pigmentation. Because pigmentation pathways are complex in their patterns, many of the better-studied human albinism traits provide insight into how pigmentation SNPs interact, control, or modify gene expression and show varying degrees of association with the key genes identified to date. These aspects of SNP action are discussed in an overview of each of the functional groups of pigmentation genes. PMID:26227136

  4. Pirfenidone inhibits migration, differentiation, and proliferation of human retinal pigment epithelial cells in vitro

    PubMed Central

    Wang, Jing; Yang, Yangfan; Xu, Jiangang; Lin, Xianchai; Wu, Kaili

    2013-01-01

    Purpose To investigate the effects of pirfenidone (PFD) on the migration, differentiation, and proliferation of retinal pigment epithelial (RPE) cells and demonstrate whether the drug induces cytotoxicity. Methods Human RPE cells (line D407) were treated with various concentrations of PFD. Cell migration was measured with scratch assay. The protein levels of fibronectin (FN), connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), transforming growth factor beta (TGFβS), and Smads were assessed with western blot analyses. Levels of mRNA of TGFβS, FN, and Snail1 were analyzed using reverse transcriptase–polymerase chain reaction. Cell apoptosis was detected with flow cytometry using the Annexin V/PI apoptosis kit, and the percentages of cells labeled in different apoptotic stage were compared. A Trypan Blue assay was used to assess cell viability. Results PFD inhibited RPE cell migration. Western blot analyses showed that PFD inhibited the expression of FN, α-SMA, CTGF, TGFβ1, TGFβ2, Smad2/3, and Smad4. Similarly, PFD also downregulated mRNA levels of Snail1, FN, TGFβ1, and TGFβ2. No significant differences in cell apoptosis or viability were observed between the control and PFD-treated groups. Conclusions PFD inhibited RPE cell migration, differentiation, and proliferation in vitro and caused no significant cytotoxicity. PMID:24415895

  5. Histologic Basis of Variations in Retinal Pigment Epithelium Autofluorescence in Eyes with Geographic Atrophy

    PubMed Central

    Rudolf, Martin; Vogt, Susan D.; Curcio, Christine A.; Huisingh, Carrie; McGwin, Gerald; Wagner, Anna; Grisanti, Salvatore; Read, Russell W.

    2013-01-01

    Purpose Lipofuscin contained in the retinal pigment epithelium (RPE) is the main source of fundus auto-fluorescence (FAF), the target of an imaging method useful for estimating the progression of geographic atrophy (GA) in clinical trials. To establish a cellular basis for hyperfluorescent GA border zones, histologic autofluorescence (HAF) was measured at defined stages of RPE pathologic progression. Design Experimental study. Participants and Controls Ten GA donor eyes (mean age ± standard deviation, 87.1±4.0 years) and 3 age-matched control eyes (mean age ± standard deviation, 84.0±7.2 years) without GA. Methods Ten–micrometer-thick sections were divided into zones of RPE morphologic features according to an 8-point scale. Any HAF excited by 488 nm light was imaged by laser confocal microscopy. The HAF intensity summed along vertical lines perpendicular to Bruch’s membrane at 0.2-μm intervals served as a surrogate for FAF. Intensity profiles in 151 zones were normalized to grade 0 at a standard reference location in each eye. Cross-sectional area, mean, and sum autofluorescence for individual RPE cells were measured (cellular autofluorescence [CAF]). Main Outcome Measures Statistically significant differences in intensity and localization of HAF and CAF at defined stages of RPE morphologic progression for GA and control eyes. Results The RPE morphologic features were most abnormal (cell rounding, sloughing, and layering; grade 2) and HAF intensity profiles were highest and most variable immediately adjacent to atrophic areas. Peaks in HAF intensity frequently were associated with vertically superimposed cells. The HAF value that optimally separated reactive RPE was 0.66 standard deviations more than the mean for uninvolved RPE and was associated with a sensitivity of 75.8% and a specificity of 76.3%. When variable cell area was accounted for, neither mean nor sum CAF differed significantly among the RPE pathologic grades. Conclusions Areas with advanced

  6. Direct evidence for positive selection of skin, hair, and eye pigmentation in Europeans during the last 5,000 y.

    PubMed

    Wilde, Sandra; Timpson, Adrian; Kirsanow, Karola; Kaiser, Elke; Kayser, Manfred; Unterländer, Martina; Hollfelder, Nina; Potekhina, Inna D; Schier, Wolfram; Thomas, Mark G; Burger, Joachim

    2014-04-01

    Pigmentation is a polygenic trait encompassing some of the most visible phenotypic variation observed in humans. Here we present direct estimates of selection acting on functional alleles in three key genes known to be involved in human pigmentation pathways--HERC2, SLC45A2, and TYR--using allele frequency estimates from Eneolithic, Bronze Age, and modern Eastern European samples and forward simulations. Neutrality was overwhelmingly rejected for all alleles studied, with point estimates of selection ranging from around 2-10% per generation. Our results provide direct evidence that strong selection favoring lighter skin, hair, and eye pigmentation has been operating in European populations over the last 5,000 y. PMID:24616518

  7. Direct evidence for positive selection of skin, hair, and eye pigmentation in Europeans during the last 5,000 y

    PubMed Central

    Wilde, Sandra; Timpson, Adrian; Kirsanow, Karola; Kaiser, Elke; Kayser, Manfred; Unterländer, Martina; Hollfelder, Nina; Potekhina, Inna D.; Schier, Wolfram; Thomas, Mark G.; Burger, Joachim

    2014-01-01

    Pigmentation is a polygenic trait encompassing some of the most visible phenotypic variation observed in humans. Here we present direct estimates of selection acting on functional alleles in three key genes known to be involved in human pigmentation pathways—HERC2, SLC45A2, and TYR—using allele frequency estimates from Eneolithic, Bronze Age, and modern Eastern European samples and forward simulations. Neutrality was overwhelmingly rejected for all alleles studied, with point estimates of selection ranging from around 2–10% per generation. Our results provide direct evidence that strong selection favoring lighter skin, hair, and eye pigmentation has been operating in European populations over the last 5,000 y. PMID:24616518

  8. Sub-cellular localisation of the white/scarlet ABC transporter to pigment granule membranes within the compound eye of Drosophila melanogaster.

    PubMed

    Mackenzie, S M; Howells, A J; Cox, G B; Ewart, G D

    2000-01-01

    The white, scarlet, and brown genes of Drosophila melanogaster encode ABC transporters involved with the uptake and storage of metabolic precursors to the red and brown eye colour pigments. It has generally been assumed that these proteins are localised in the plasma membrane and transport precursor molecules from the heamolymph into the eye pigment cells. However, the immuno-electron microscopy experiments in this study reveal that the White and Scarlet proteins are located in the membranes of pigment granules within pigment cells and retinula cells of the compound eye. No evidence of their presence in the plasma membrane was observed. This result suggests that, rather than tranporting tryptophan into the cell across the plasma membrane, the White/Scarlet complex transports a metabolic intermediate (such as 3-hydroxy kynurenine) from the cytoplasm into the pigment granules. Other functional implications of this new finding are discussed. PMID:11294610

  9. Delivery of Celecoxib for Treating Diseases of the Eye: Influence of Pigment and Diabetes

    PubMed Central

    Kompella, Uday; Amrite, Aniruddha C; Pugazhenthi, Vidya; Cheruvu, Narayan PS

    2010-01-01

    Importance of the field Age-related macular degeneration (AMD) and diabetic retinopathy (DR) are two major causes of blindness. In these disorders, growth factors such as vascular endothelial growth factor (VEGF) are upregulated leading to either enhanced vascular permeability or proliferation of endothelium. While currently available corticosteroid therapies suffer from side effects including cataracts and elevated intraocular pressure, anti-VEGF antibody therapies require frequent intravitreal injections, a procedure that can potentially lead to retinal detachment or endophthalmitis. Thus, there is currently a need to develop safe, sustained release therapeutic approaches for treating AMD and DR. Areas covered in this review This review discusses the pharmacological basis for using celecoxib, an anti-inflammatory drug capable of selectively inhibiting cycloxygenase 2, in treating AMD and DR. In addition, this article discusses the safety, delivery advantage, and efficacy of celecoxib by transscleral retinal delivery, a periocular delivery approach that is less invasive to the globe compared to intravitreal injections. What the reader will gain The reader will gain insights into the development of a pharmacological agent and a sustained release delivery system for treating DR and AMD. Further, the reader will gain insights into the role of eye physiology including pigmentation and disease states such as DR on retinal drug delivery. Take home message Transscleral sustained delivery of anti-inflammatory agents is a viable option for treating retinal disorders. PMID:20205602

  10. Identification and characterization of visual pigments in caecilians (Amphibia: Gymnophiona), an order of limbless vertebrates with rudimentary eyes.

    PubMed

    Mohun, S M; Davies, W L; Bowmaker, J K; Pisani, D; Himstedt, W; Gower, D J; Hunt, D M; Wilkinson, M

    2010-10-15

    In comparison with the other amphibian orders, the Anura (frogs) and Urodela (salamanders), knowledge of the visual system of the snake-like Gymnophiona (caecilians) is relatively sparse. Most caecilians are fossorial with, as far as is known any surface activity occurring mainly at night. They have relatively small, poorly developed eyes and might be expected to possess detectable changes in the spectral sensitivity of their visual pigments. Microspectrophotometry was used to determine the spectral sensitivities of the photoreceptors in three species of caecilian, Rhinatrema bivittatum, Geotrypetes seraphini and Typhlonectes natans. Only rod opsin visual pigment, which may be associated with scotopic (dim light) vision when accompanied by other 'rod-specific' components of the phototransduction cascade, was found to be present. Opsin sequences were obtained from the eyes of two species of caecilian, Ichthyophis cf. kohtaoensis and T. natans. These rod opsins were regenerated in vitro with 11-cis retinal to give pigments with spectral sensitivity peaks close to 500 nm. No evidence for cone photoreception, associated with diurnal and colour vision, was detected using molecular and physiological methods. Additionally, visual pigments are short-wavelength shifted in terms of the maximum absorption of light when compared with other amphibian lineages. PMID:20889838

  11. SCF/c-kit signaling is required in 12-O-tetradecanoylphorbol-13-acetate-induced migration and differentiation of hair follicle melanocytes for epidermal pigmentation.

    PubMed

    Qiu, Weiming; Yang, Ke; Lei, Mingxing; Yan, Hongtao; Tang, Hui; Bai, Xiufeng; Yang, Guihong; Lian, Xiaohua; Wu, Jinjin

    2015-05-01

    Hair follicle melanocyte stem cells (McSCs) are responsible for hair pigmentation and also function as a major melanocyte reservoir for epidermal pigmentation. However, the molecular mechanism promoting McSCs for epidermal pigmentation remains elusive. 12-O-tetradecanoylphorbol-13-acetate (TPA) mimics key signaling involved in melanocyte growth, migration and differentiation. We therefore investigated the molecular basis for the contribution of hair follicle McSCs to epidermal pigmentation using the TPA induction model. We found that repetitive TPA treatment of female C57BL/6 mouse dorsal skin induced epidermal pigmentation by increasing the number of epidermal melanocytes. Particularly, TPA treatment induced McSCs to initiate proliferation, exit the stem cell niche and differentiate. We also demonstrated that TPA promotes melanoblast migration and differentiation in vitro. At the molecular level, TPA treatment induced robust expression of stem cell factor (SCF) in keratinocytes and c-kit in melanoblasts and melanocytes. Administration of ACK2, a neutralizing antibody against the Kit receptor, suppressed mouse epidermal pigmentation, decreased the number of epidermal melanocytes, and inhibited melanoblast migration. Taken together, our data demonstrate that TPA promotes the expansion, migration and differentiation of hair follicle McSCs for mouse epidermal pigmentation. SCF/c-kit signaling was required for TPA-induced migration and differentiation of hair follicle melanocytes. Our findings may provide an excellent model to investigate the signaling mechanisms regulating epidermal pigmentation from mouse hair follicle McSCs, and a potential therapeutic option for skin pigmentation disorders. PMID:25727244

  12. Comparison of accumulation of clenbuterol and salbutamol residues in animal internal tissues, non-pigmented eyes and hair.

    PubMed

    Pleadin, Jelka; Vulić, Ana; Terzić, Svjetlana; Vahčić, Nada; Šandor, Ksenija; Perak, Eleonora

    2014-01-01

    The aim of the study was to compare the accumulation of β-adrenergic agonist residues clenbuterol (CLB) and salbutamol (SAL) in internal tissues, non-pigmented eyes and hair of laboratory animals repeatedly administered with CLB and SAL during 7 days. Experimental albino guinea pigs (n = 20) were treated with CLB (n = 10) and SAL (n = 10) in anabolic doses of 0.25 and 2.5 mg/kg, whereas the control animal group (n = 10) was left untreated. Methodology validation showed that the ELISA assay to be suitable for β-agonists' semiquantitative determination. The results revealed a significantly higher (P < 0.05) accumulation potential of CLB in comparison with SAL in all investigated tissues. Despite of their lack of pigmentation and the applied dose, the highest residual CLB concentrations were determined in the eyes of the studied animals, followed by their hair, liver, lungs, kidney, heart and adipose and muscle tissue, whereas residual SAL concentrations found in the eyes and hair of the administered animals did not significantly differ (P > 0.05) from those obtained in their internal tissues. PMID:24990876

  13. Macular Pigment Imaging in AREDS2 Participants: An Ancillary Study of AREDS2 Subjects Enrolled at the Moran Eye Center

    PubMed Central

    Bernstein, Paul S.; Ahmed, Faisal; Liu, Aihua; Allman, Susan; Sheng, Xiaoming; Sharifzadeh, Mohsen; Ermakov, Igor; Gellermann, Werner

    2012-01-01

    Purpose. Age-Related Eye Disease Study 2 (AREDS2) is a randomized, placebo-controlled study designed to determine whether supplementation with 10 mg of lutein and 2 mg of zeaxanthin per day can slow the rate of progression of age-related macular degeneration (AMD). Although some biomarkers of response to carotenoid supplementation such as serum concentrations are part of the AREDS2 protocol, measurement of carotenoid concentrations in the eye and other tissues is not. In this approved ancillary study, macular pigment optical density (MPOD), macular pigment distributions, and skin carotenoid levels at enrollment and at each annual visit were measured to assess baseline carotenoid status and to monitor response to assigned interventions. Methods. All subjects enrolled at the Moran Eye Center had MPOD and macular pigment spatial distributions measured by dual-wavelength autofluorescence imaging and total skin carotenoids measured by resonance Raman spectroscopy. Results. Baseline MPOD in enrolled subjects was unusually high relative to an age-matched control group that did not consume carotenoid supplements regularly, consistent with the high rate of habitual lutein and zeaxanthin consumption in Utah AREDS2 subjects prior to enrollment. MPOD did not correlate with serum or skin carotenoid measurements. Conclusions. Useful information is provided through this ancillary study on the ocular carotenoid status of AREDS2 participants in the target tissue of lutein and zeaxanthin supplementation: The macula. When treatment assignments are unmasked at the conclusion of the study, unique tissue-based insights will be provided on the progression of AMD in response to long-term, high-dose carotenoid supplementation versus diet alone. (ClinicalTrials.gov number, NCT00345176.) PMID:22879423

  14. From a Bird's Eye View: An Interdisciplinary Approach to Migration

    ERIC Educational Resources Information Center

    Benson, Juliann

    2007-01-01

    Inspiring students to learn about birds can be a daunting task--students see birds just about every day and often don't think twice about them. The activity described here is designed to excite students to "become" birds. Students are asked to create a model and tell the life story of a bird by mapping its migration pattern. (Contains 6 figures, 6…

  15. Rhabdom constriction enhances filtering by the red screening pigment in the eye of the Eastern Pale Clouded yellow butterfly, Colias erate (Pieridae).

    PubMed

    Arikawa, Kentaro; Pirih, Primoz; Stavenga, Doekele G

    2009-07-01

    Here we report the remarkable anatomy of the eye of the Eastern Pale Clouded yellow butterfly, Colias erate. An ommatidium of C. erate bears nine photoreceptors, R1-9, which together form a tiered and fused rhabdom. The distal tier of the rhabdom consists of the rhabdomeral microvilli of R1-4 photoreceptors, R5-8 photoreceptors contribute the proximal tier, and the R9 photoreceptor adds a few microvilli at the base. In transverse sections, four spots of red pigment surrounding the rhabdom are evident in the ventral region of the eye. The red pigment acts as a strong red filter for the proximal photoreceptors. The arrangement of the pigment spots distinguishes the ommatidia into three types: trapezoidal (type I), square (type II) and rectangular (type III). In all types of ommatidia, the distal and the proximal tiers of the rhabdom are divided by a strong constriction, clearly to enhance the filtering effect of the red pigment. The ommatidial heterogeneity can also be observed by optical measurements. The eye shine, resulting from tapetal reflections, peaks in type I ommatidia at 660 nm, and in type II and III ommatidia at 730 nm. The far-red-peaking eye shine indicates that C. erate has far-red-sensitive photoreceptors. Type I ommatidia fluoresce under violet excitation, implying the presence of a violet-absorbing pigment that acts as a short-wavelength filter. PMID:19525432

  16. Eye drop delivery of pigment epithelium-derived factor-34 promotes retinal ganglion cell neuroprotection and axon regeneration.

    PubMed

    Vigneswara, Vasanthy; Esmaeili, Maryam; Deer, Louise; Berry, Martin; Logan, Ann; Ahmed, Zubair

    2015-09-01

    Axotomised retinal ganglion cells (RGCs) die rapidly by apoptosis and fail to regenerate because of the limited availability of neurotrophic factors and a lack of axogenic stimuli. However, we have recently showed that pigment epithelium-derived factor (PEDF) promotes RGC survival and axon regeneration after optic nerve crush injury. PEDF has multiple fragments of the native peptide that are neuroprotective, anti-angiogenic and anti-inflammatory. Here we investigated the neuroprotective and axogenic properties of a fragment of PEDF, PEDF-34, in retinal neurons in vitro and when delivered by intravitreal injection and eye drops in vivo. We found that PEDF-34 was 43% more neuroprotective and 52% more neuritogenic than PEDF-44 in vitro. Moreover, in vivo, intravitreal delivery of 1.88nM PEDF-34 was 71% RGC neuroprotective at 21days after optic nerve crush compared to intact controls, whilst daily eye drops containing 1.88nM PEDF-34 promoted 87% RGC survival. After topical eye drop delivery, PEDF-34 was detected in the vitreous body within 30min and attained physiologically relevant concentrations in the retina by 4h peaking at 1.4±0.05nM by 14days. In eye drop- compared to intravitreal-treated PEDF-34 animals, 55% more RGC axons regenerated 250μm beyond the optic nerve lesion. We conclude that daily topical eye drop application of PEDF-34 is superior to weekly intravitreal injections in promoting RGC survival and axon regeneration through both direct effects on retinal neurons and indirect effects on other retinal cells. PMID:26260110

  17. Eye drop delivery of pigment epithelium-derived factor-34 promotes retinal ganglion cell neuroprotection and axon regeneration

    PubMed Central

    Vigneswara, Vasanthy; Esmaeili, Maryam; Deer, Louise; Berry, Martin; Logan, Ann; Ahmed, Zubair

    2015-01-01

    Axotomised retinal ganglion cells (RGCs) die rapidly by apoptosis and fail to regenerate because of the limited availability of neurotrophic factors and a lack of axogenic stimuli. However, we have recently showed that pigment epithelium-derived factor (PEDF) promotes RGC survival and axon regeneration after optic nerve crush injury. PEDF has multiple fragments of the native peptide that are neuroprotective, anti-angiogenic and anti-inflammatory. Here we investigated the neuroprotective and axogenic properties of a fragment of PEDF, PEDF-34, in retinal neurons in vitro and when delivered by intravitreal injection and eye drops in vivo. We found that PEDF-34 was 43% more neuroprotective and 52% more neuritogenic than PEDF-44 in vitro. Moreover, in vivo, intravitreal delivery of 1.88 nM PEDF-34 was 71% RGC neuroprotective at 21 days after optic nerve crush compared to intact controls, whilst daily eye drops containing 1.88 nM PEDF-34 promoted 87% RGC survival. After topical eye drop delivery, PEDF-34 was detected in the vitreous body within 30 min and attained physiologically relevant concentrations in the retina by 4 h peaking at 1.4 ± 0.05 nM by 14 days. In eye drop- compared to intravitreal-treated PEDF-34 animals, 55% more RGC axons regenerated 250 μm beyond the optic nerve lesion. We conclude that daily topical eye drop application of PEDF-34 is superior to weekly intravitreal injections in promoting RGC survival and axon regeneration through both direct effects on retinal neurons and indirect effects on other retinal cells. PMID:26260110

  18. Inadvertent migration of guidewire into Murphy's eye of endotracheal tube during percutaneous dilatational tracheostomy

    PubMed Central

    Panigrahi, Binita; Samaddar, Devi Prasad; Kumar, Tushar

    2016-01-01

    Percutaneous dilatational tracheostomy is a commonly performed bedside procedure in the Intensive Care Unit. Although serious and fatal complications have been reported, the procedure is by and large safe to perform in experienced hands. We report here an innocuous problem encountered twice. After the guidewire insertion and dilatation, subsequent railroading became difficult owing to migration of guidewire into the Murphy's eye of the endotracheal tube (ETT). Awareness about this possibility can avert inadvertent delays and complications during the procedure. A tug or gentle pulling of ETT after insertion of the guidewire rules out an impaction in the eye or other part of the ETT. PMID:27076734

  19. Coexpression of two visual pigments in a photoreceptor causes an abnormally broad spectral sensitivity in the eye of the butterfly Papilio xuthus.

    PubMed

    Arikawa, Kentaro; Mizuno, Shin; Kinoshita, Michiyo; Stavenga, Doekele G

    2003-06-01

    The compound eye of the butterfly Papilio xuthus consists of three different types of ommatidia, each containing nine photoreceptor cells (R1-R9). We have found previously that the R5-R8 photoreceptors of type II ommatidia coexpress two different mRNAs, encoding opsins of green- and orange-red-absorbing visual pigments (Kitamoto et al., 1998). Do these cells contain two functionally distinct visual pigments? First, we identified the sensitivity spectrum of these photoreceptors by using combined intracellular recording and dye injection. We thus found that the R5-R8 of type II ommatidia have a characteristic sensitivity spectrum extending over an excessively broad spectral range, from the violet to the red region; the photoreceptors are therefore termed broadband photoreceptors. The spectral shape was interpreted with a computational model for type II ommatidia, containing a UV visual pigment in cells R1 and R2, two green visual pigments in cells R3 and R4, a far-UV-absorbing screening pigment (3-hydroxyretinol) in the distal part of the ommatidium, and a red-screening pigment that surrounds the rhabdom. The modeling suggests that both visual pigments in the R5-R8 photoreceptors participate in phototransduction. This work provides the first compelling evidence that multiple visual pigments participate in phototransduction in single invertebrate photoreceptors. PMID:12805293

  20. Spinster controls Dpp signaling during glial migration in the Drosophila eye.

    PubMed

    Yuva-Aydemir, Yeliz; Bauke, Ann-Christin; Klämbt, Christian

    2011-05-11

    The development of multicellular organisms requires the well balanced and coordinated migration of many cell types. This is of particular importance within the developing nervous system, where glial cells often move long distances to reach their targets. The majority of glial cells in the peripheral nervous system of the Drosophila embryo is derived from the CNS and migrates along motor axons toward their targets. In the developing Drosophila eye, CNS-derived glial cells move outward toward the nascent photoreceptor cells, but the molecular mechanisms coupling the migration of glial cells with the growth of the eye imaginal disc are mostly unknown. Here, we used an enhancer trap approach to identify the gene spinster, which encodes a multipass transmembrane protein involved in endosome-lysosome trafficking, as being expressed in many glial cells. spinster mutants are characterized by glial overmigration. Genetic experiments demonstrate that Spinster modulates the activity of several signaling cascades. Within the migrating perineurial glial cells, Spinster is required to downregulate Dpp (Decapentaplegic) signaling activity, which ceases migratory abilities. In addition, Spinster affects the growth of the carpet cell, which indirectly modulates glial migration. PMID:21562262

  1. Migration study of 1,3-butadiene in eye-drop solutions.

    PubMed

    Pistos, Constantinos; Karampela, Sevasti; Vardakou, Ioanna; Papoutsis, Ioannis; Spiliopoulou, Chara; Athanaselis, Sotiris

    2012-07-01

    The potential deleterious effects of extractables/leachables in pharmaceutical products led the USP, EP, and JP to require extractable and toxicity testing of container/closure systems. To that, a headspace gas chromatography flame ionization detection method was developed and validated for the determination of 1,3-butadiene (1,3-BD) as a potential extractable residue from a pharmaceutical container/closure system into eye-drop solutions. A migration study was further applied in eight eye-drop solutions (currently marketed products) after short- and long-term exposure of these products at various temperatures. This method allows the establishment of safety-qualification thresholds for 1,3-BD being capable of monitoring eye-drop solution products for this residue. PMID:22187982

  2. Lipofuscin Redistribution and Loss Accompanied by Cytoskeletal Stress in Retinal Pigment Epithelium of Eyes With Age-Related Macular Degeneration

    PubMed Central

    Ach, Thomas; Tolstik, Elen; Messinger, Jeffrey D.; Zarubina, Anna V.; Heintzmann, Rainer; Curcio, Christine A.

    2015-01-01

    Purpose. Lipofuscin (LF) and melanolipofuscin (MLF) of the retinal pigment epithelium (RPE) are the principal sources of autofluorescence (AF) signals in clinical fundus–AF imaging. Few details about the subcellular distribution of AF organelles in AMD are available. We describe the impact of aging and AMD on RPE morphology revealed by the distribution of AF LF/MLF granules and actin cytoskeleton in human tissues. Methods. Thirty-five RPE-Bruch's membrane flatmounts from 35 donors were prepared (postmortem: ≤4 hours). Ex vivo fundus examination at the time of accession revealed either absence of chorioretinal pathologies (10 tissues; mean age: 83.0 ± 2.6 years) or stages of AMD (25 tissues; 85.0 ± 5.8 years): early AMD, geographic atrophy, and late exudative AMD. Retinal pigment epithelium cytoskeleton was labeled with AlexaFluor647-Phalloidin. Tissues were imaged on a spinning-disk fluorescence microscope and a high-resolution structured illumination microscope. Results. Age-related macular degeneration impacts individual RPE cells by (1) lipofuscin redistribution by (i) degranulation (granule-by-granule loss) and/or (ii) aggregation and apparent shedding into the extracellular space; (2) enlarged RPE cell area and conversion from convex to irregular and sometimes concave polygons; and (3) cytoskeleton derangement including separations and breaks around subretinal deposits, thickening, and stress fibers. Conclusions. We report an extensive and systematic en face analysis of LF/MLF-AF in AMD eyes. Redistribution and loss of AF granules are among the earliest AMD changes and could reduce fundus AF signal attributable to RPE at these locations. Data can enhance the interpretation of clinical fundus–AF and provide a basis for future quantitative studies. PMID:25758814

  3. High glucose promotes the migration of retinal pigment epithelial cells through increased oxidative stress and PEDF expression.

    PubMed

    Farnoodian, Mitra; Halbach, Caroline; Slinger, Cassidy; Pattnaik, Bikash R; Sorenson, Christine M; Sheibani, Nader

    2016-09-01

    Defects in the outer blood-retinal barrier have significant impact on the pathogenesis of diabetic retinopathy and macular edema. However, the detailed mechanisms involved remain largely unknown. This is, in part, attributed to the lack of suitable animal and cell culture models, including those of mouse origin. We recently reported a method for the culture of retinal pigment epithelial (RPE) cells from wild-type and transgenic mice. The RPE cells are responsible for maintaining the integrity of the outer blood-retinal barrier whose dysfunction during diabetes has a significant impact on vision. Here we determined the impact of high glucose on the function of RPE cells. We showed that high glucose conditions resulted in enhanced migration and increased the level of oxidative stress in RPE cells, but minimally impacted their rate of proliferation and apoptosis. High glucose also minimally affected the cell-matrix and cell-cell interactions of RPE cells. However, the expression of integrins and extracellular matrix proteins including pigment epithelium-derived factor (PEDF) were altered under high glucose conditions. Incubation of RPE cells with the antioxidant N-acetylcysteine under high glucose conditions restored normal migration and PEDF expression. These cells also exhibited increased nuclear localization of the antioxidant transcription factor Nrf2 and ZO-1, reduced levels of β-catenin and phagocytic activity, and minimal effect on production of vascular endothelial growth factor, inflammatory cytokines, and Akt, MAPK, and Src signaling pathways. Thus high glucose conditions promote RPE cell migration through increased oxidative stress and expression of PEDF without a significant effect on the rate of proliferation and apoptosis. PMID:27440660

  4. Yellow-throated and Red-eyed Vireos foraging on green anoles during migration

    USGS Publications Warehouse

    Sykes, P.W., Jr.; Atherton, L.S.; Payne, R.L.

    2007-01-01

    Yellow-throated (Vireo flavifrons) and Red-eyed vireos (V. olivaceus) were observed feeding on green anoles (Anolis carolinensis carolinensis) at two localities in Florida and one in South Carolina. Vireos are long-distance migrants that require foods high in fatty acid content, especially when engaging in migration. It is not unlikely that vireos have an opportunistic foraging strategy to obtain the necessary food requirements, including attacking and consuming prey items such as small lizards. This note provides the first published reports of lizards taken as prey by these two species.

  5. Nanofiber Scaffold-Based Tissue-Engineered Retinal Pigment Epithelium to Treat Degenerative Eye Diseases.

    PubMed

    Hotaling, Nathan A; Khristov, Vladimir; Wan, Qin; Sharma, Ruchi; Jha, Balendu Shekhar; Lotfi, Mostafa; Maminishkis, Arvydas; Simon, Carl G; Bharti, Kapil

    2016-06-01

    Clinical-grade manufacturing of a functional retinal pigment epithelium (RPE) monolayer requires reproducing, as closely as possible, the natural environment in which RPE grows. In vitro, this can be achieved by a tissue engineering approach, in which the RPE is grown on a nanofibrous biological or synthetic scaffold. Recent research has shown that nanofiber scaffolds perform better for cell growth and transplantability compared with their membrane counterparts and that the success of the scaffold in promoting cell growth/function is not heavily material dependent. With these strides, the field has advanced enough to begin to consider implementation of one, or a combination, of the tissue engineering strategies discussed herein. In this study, we review the current state of tissue engineering research for in vitro culture of RPE/scaffolds and the parameters for optimal scaffold design that have been uncovered during this research. Next, we discuss production methods and manufacturers that are capable of producing the nanofiber scaffolds in such a way that would be biologically, regulatory, clinically, and commercially viable. Then, a discussion of how the scaffolds could be characterized, both morphologically and mechanically, to develop a testing process that is viable for regulatory screening is performed. Finally, an example of a tissue-engineered RPE/scaffold construct is given to provide the reader a framework for understanding how these pieces could fit together to develop a tissue-engineered RPE/scaffold construct that could pass regulatory scrutiny and can be commercially successful. PMID:27110730

  6. Identification of hydroxyapatite spherules provides new insight into subretinal pigment epithelial deposit formation in the aging eye.

    PubMed

    Thompson, Richard B; Reffatto, Valentina; Bundy, Jacob G; Kortvely, Elod; Flinn, Jane M; Lanzirotti, Antonio; Jones, Emrys A; McPhail, David S; Fearn, Sarah; Boldt, Karsten; Ueffing, Marius; Ratu, Savanjeet Guy Singh; Pauleikhoff, Laurenz; Bird, Alan C; Lengyel, Imre

    2015-02-01

    Accumulation of protein- and lipid-containing deposits external to the retinal pigment epithelium (RPE) is common in the aging eye, and has long been viewed as the hallmark of age-related macular degeneration (AMD). The cause for the accumulation and retention of molecules in the sub-RPE space, however, remains an enigma. Here, we present fluorescence microscopy and X-ray diffraction evidence for the formation of small (0.5-20 μm in diameter), hollow, hydroxyapatite (HAP) spherules in Bruch's membrane in human eyes. These spherules are distinct in form, placement, and staining from the well-known calcification of the elastin layer of the aging Bruch's membrane. Secondary ion mass spectrometry (SIMS) imaging confirmed the presence of calcium phosphate in the spherules and identified cholesterol enrichment in their core. Using HAP-selective fluorescent dyes, we show that all types of sub-RPE deposits in the macula, as well as in the periphery, contain numerous HAP spherules. Immunohistochemical labeling for proteins characteristic of sub-RPE deposits, such as complement factor H, vitronectin, and amyloid beta, revealed that HAP spherules were coated with these proteins. HAP spherules were also found outside the sub-RPE deposits, ready to bind proteins at the RPE/choroid interface. Based on these results, we propose a novel mechanism for the growth, and possibly even the formation, of sub-RPE deposits, namely, that the deposit growth and formation begin with the deposition of insoluble HAP shells around naturally occurring, cholesterol-containing extracellular lipid droplets at the RPE/choroid interface; proteins and lipids then attach to these shells, initiating or supporting the growth of sub-RPE deposits. PMID:25605911

  7. Identification of Atg2 and ArfGAP1 as Candidate Genetic Modifiers of the Eye Pigmentation Phenotype of Adaptor Protein-3 (AP-3) Mutants in Drosophila melanogaster

    PubMed Central

    Rodriguez-Fernandez, Imilce A.; Dell’Angelica, Esteban C.

    2015-01-01

    The Adaptor Protein (AP)-3 complex is an evolutionary conserved, molecular sorting device that mediates the intracellular trafficking of proteins to lysosomes and related organelles. Genetic defects in AP-3 subunits lead to impaired biogenesis of lysosome-related organelles (LROs) such as mammalian melanosomes and insect eye pigment granules. In this work, we have performed a forward screening for genetic modifiers of AP-3 function in the fruit fly, Drosophila melanogaster. Specifically, we have tested collections of large multi-gene deletions–which together covered most of the autosomal chromosomes–to identify chromosomal regions that, when deleted in single copy, enhanced or ameliorated the eye pigmentation phenotype of two independent AP-3 subunit mutants. Fine-mapping led us to define two non-overlapping, relatively small critical regions within fly chromosome 3. The first critical region included the Atg2 gene, which encodes a conserved protein involved in autophagy. Loss of one functional copy of Atg2 ameliorated the pigmentation defects of mutants in AP-3 subunits as well as in two other genes previously implicated in LRO biogenesis, namely Blos1 and lightoid, and even increased the eye pigment content of wild-type flies. The second critical region included the ArfGAP1 gene, which encodes a conserved GTPase-activating protein with specificity towards GTPases of the Arf family. Loss of a single functional copy of the ArfGAP1 gene ameliorated the pigmentation phenotype of AP-3 mutants but did not to modify the eye pigmentation of wild-type flies or mutants in Blos1 or lightoid. Strikingly, loss of the second functional copy of the gene did not modify the phenotype of AP-3 mutants any further but elicited early lethality in males and abnormal eye morphology when combined with mutations in Blos1 and lightoid, respectively. These results provide genetic evidence for new functional links connecting the machinery for biogenesis of LROs with molecules implicated

  8. Guanine deaminase functions as dihydropterin deaminase in the biosynthesis of aurodrosopterin, a minor red eye pigment of Drosophila.

    PubMed

    Kim, Jaekwang; Park, Sang Ick; Ahn, Chiyoung; Kim, Heuijong; Yim, Jeongbin

    2009-08-28

    Dihydropterin deaminase, which catalyzes the conversion of 7,8-dihydropterin to 7,8-dihydrolumazine, was purified 5850-fold to apparent homogeneity from Drosophila melanogaster. Its molecular mass was estimated to be 48 kDa by gel filtration and SDS-PAGE, indicating that it is a monomer under native conditions. The pI value, temperature, and optimal pH of the enzyme were 5.5, 40 degrees C, and 7.5, respectively. Interestingly the enzyme had much higher activity for guanine than for 7,8-dihydropterin. The specificity constant (k(cat)/K(m)) for guanine (8.6 x 10(6) m(-1).s(-1)) was 860-fold higher than that for 7,8-dihydropterin (1.0 x 10(4) m(-1).s(-1)). The structural gene of the enzyme was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis as CG18143, located at region 82A1 on chromosome 3R. The cloned and expressed CG18143 exhibited both 7,8-dihydropterin and guanine deaminase activities. Flies with mutations in CG18143, SUPor-P/Df(3R)A321R1 transheterozygotes, had severely decreased activities in both deaminases compared with the wild type. Among several red eye pigments, the level of aurodrosopterin was specifically decreased in the mutant, and the amount of xanthine and uric acid also decreased considerably to 76 and 59% of the amounts in the wild type, respectively. In conclusion, dihydropterin deaminase encoded by CG18143 plays a role in the biosynthesis of aurodrosopterin by providing one of its precursors, 7,8-dihydrolumazine, from 7,8-dihydropterin. Dihydropterin deaminase also functions as guanine deaminase, an important enzyme for purine metabolism. PMID:19567870

  9. Analytical imaging studies of the migration of degraded orpiment, realgar, and emerald green pigments in historic paintings and related conservation issues

    DOE PAGESBeta

    Keune, Katrien; Mass, Jennifer; Mehta, Apurva; Church, Jonathan; Meirer, Florian

    2016-04-21

    Yellow orpiment (As2S3) and red–orange realgar (As4S4) photo-degrade and the nineteenth-century pigment emerald green (Cu(C2H3O2)2·3Cu(AsO2)2) degrades into arsenic oxides. Because of their solubility in water, arsenic oxides readily migrate and are found throughout the multi-layered paint system. The widespread arsenic migration has consequences for conservation, and this paper provides better insight into the extent of the problem. Five paint samples containing orpiment, realgar or emerald green pigments deriving from paintings by De Heem (17th C), Van Gogh (19th C), Rousseau (19th C), an unknown 17th C northern European artist and an Austrian painted cupboard (19th C) were investigated using SEM/EDX,more » imaging ATR-FTIR and arsenic (As) K–edge μ-XANES to obtain the spatial distribution and chemical speciation of arsenic in the paint system. In all of the samples investigated arsenic had migrated throughout the multi-layered paint structure of the art object, from support to varnish. Furthermore, As5+-species were found throughout the entire paint sample. We hypothesize that arsenic trioxide is first formed, dissolves in water, further oxidizes to arsenic pentaoxide, and then reacts with lead, calcium and other ions and is deposited in the paint system as insoluble arsenates. Since the degradation of arsenic pigments such as orpiment, realgar and emerald green occurs through a highly mobile intermediate stage, it not only affects the regions rich in arsenic pigments, but also the entire object, including substrate and top varnish layers. Furthermore, because of this widespread potential for damage, preventing degradation of arsenic pigments should be prioritized and conservators should minimize exposure of objects containing arsenic pigments to strong light, large fluctuations in relative humidity and water-based cleaning agents.« less

  10. Xeno-Free and Defined Human Embryonic Stem Cell-Derived Retinal Pigment Epithelial Cells Functionally Integrate in a Large-Eyed Preclinical Model

    PubMed Central

    Plaza Reyes, Alvaro; Petrus-Reurer, Sandra; Antonsson, Liselotte; Stenfelt, Sonya; Bartuma, Hammurabi; Panula, Sarita; Mader, Theresa; Douagi, Iyadh; André, Helder; Hovatta, Outi; Lanner, Fredrik; Kvanta, Anders

    2015-01-01

    Summary Human embryonic stem cell (hESC)-derived retinal pigment epithelial (RPE) cells could replace lost tissue in geographic atrophy (GA) but efficacy has yet to be demonstrated in a large-eyed model. Also, production of hESC-RPE has not yet been achieved in a xeno-free and defined manner, which is critical for clinical compliance and reduced immunogenicity. Here we describe an effective differentiation methodology using human laminin-521 matrix with xeno-free and defined medium. Differentiated cells exhibited characteristics of native RPE including morphology, pigmentation, marker expression, monolayer integrity, and polarization together with phagocytic activity. Furthermore, we established a large-eyed GA model that allowed in vivo imaging of hESC-RPE and host retina. Cells transplanted in suspension showed long-term integration and formed polarized monolayers exhibiting phagocytic and photoreceptor rescue capacity. We have developed a xeno-free and defined hESC-RPE differentiation method and present evidence of functional integration of clinically compliant hESC-RPE in a large-eyed disease model. PMID:26724907

  11. Xeno-Free and Defined Human Embryonic Stem Cell-Derived Retinal Pigment Epithelial Cells Functionally Integrate in a Large-Eyed Preclinical Model.

    PubMed

    Plaza Reyes, Alvaro; Petrus-Reurer, Sandra; Antonsson, Liselotte; Stenfelt, Sonya; Bartuma, Hammurabi; Panula, Sarita; Mader, Theresa; Douagi, Iyadh; André, Helder; Hovatta, Outi; Lanner, Fredrik; Kvanta, Anders

    2016-01-12

    Human embryonic stem cell (hESC)-derived retinal pigment epithelial (RPE) cells could replace lost tissue in geographic atrophy (GA) but efficacy has yet to be demonstrated in a large-eyed model. Also, production of hESC-RPE has not yet been achieved in a xeno-free and defined manner, which is critical for clinical compliance and reduced immunogenicity. Here we describe an effective differentiation methodology using human laminin-521 matrix with xeno-free and defined medium. Differentiated cells exhibited characteristics of native RPE including morphology, pigmentation, marker expression, monolayer integrity, and polarization together with phagocytic activity. Furthermore, we established a large-eyed GA model that allowed in vivo imaging of hESC-RPE and host retina. Cells transplanted in suspension showed long-term integration and formed polarized monolayers exhibiting phagocytic and photoreceptor rescue capacity. We have developed a xeno-free and defined hESC-RPE differentiation method and present evidence of functional integration of clinically compliant hESC-RPE in a large-eyed disease model. PMID:26724907

  12. Autologous transplantation of genetically modified iris pigment epithelial cells: A promising concept for the treatment of age-related macular degeneration and other disorders of the eye

    NASA Astrophysics Data System (ADS)

    Semkova, Irina; Kreppel, Florian; Welsandt, Gerhard; Luther, Thomas; Kozlowski, Jolanta; Janicki, Hanna; Kochanek, Stefan; Schraermeyer, Ulrich

    2002-10-01

    Age-related macular degeneration (ARMD) is the leading cause for visual impairment and blindness in the elder population. Laser photocoagulation, photodynamic therapy and excision of neovascular membranes have met with limited success. Submacular transplantation of autologous iris pigment epithelial (IPE) cells has been proposed to replace the damaged retinal pigment epithelium following surgical removal of the membranes. We tested our hypothesis that the subretinal transplantation of genetically modified autologous IPE cells expressing biological therapeutics might be a promising strategy for the treatment of ARMD and other retinal disorders. Pigment epithelium-derived factor (PEDF) has strong antiangiogenic and neuroprotective activities in the eye. Subretinal transplantation of PEDF expressing IPE cells inhibited pathological choroidal neovascularization in rat models of laser-induced rupture of Bruch's membrane and of oxygen induced ischemic retinopathy. PEDF expressing IPE transplants also increased the survival and preserved rhodopsin expression of photoreceptor cells in the RCS rat, a model of retinal degeneration. These findings suggest a promising concept for the treatment of ARMD and other retinal disorders.

  13. Distortion of frontal bones results from cell apoptosis by the mechanical force from the up-migrating eye during metamorphosis in Paralichthys olivaceus.

    PubMed

    Sun, Mingyan; Wei, Fen; Li, Hui; Xu, Juan; Chen, Xinye; Gong, Xiaoling; Tian, Yongsheng; Chen, Songlin; Bao, Baolong

    2015-05-01

    Craniofacial remodeling during flatfish metamorphosis, including eye migration, is perhaps the most striking example of asymmetric postembryonic development in the vertebrate world. The asymmetry of the cranium mainly results from distortion of the frontal bones, which depends on eye migration during metamorphosis. However, it is unclear how the up-migrating eye causes distortion of the frontal bones. In this study, we first show that distortion of the frontal bones during metamorphosis in Paralichthys olivaceus is the result of cell apoptosis, rather than cell autophagy or cell proliferation. Secondly, we report that cell apoptosis in the frontal bones is induced by the mechanical force transferred from the up-migrating eye. The mechanical force from the up-migrating eye signals through FAK to downstream molecules that are integrated into the BMP-2 signal pathway. Finally, it is shown that cell apoptosis in the frontal bones is activated by the intrinsic mitochondrial pathway; the extrinsic death receptor is not involved in this process. Moreover, cell apoptosis in frontal bones is not induced directly by thyroid hormones, which are thought to mediate metamorphosis in flatfishes and directly mediate cell apoptosis during amphibian metamorphosis. These findings help identify the major signaling route used during regulation of frontal bone distortion during metamorphosis in flatfish, and indicate that the asymmetry of the cranium, or at least the distortion of frontal bones, is the result of rather than the reason underlying eye migration. PMID:25622577

  14. A Unifying Concept of Uveal Pigment Cell Distribution and Dissemination Based on an Animal Model: Insights into Ocular Melanogenesis.

    PubMed

    Schwab, Christoph; Wackernagel, Werner; Grinninger, Petra; Mayer, Christoph; Schwab, Katharina; Langmann, Gerald; Richtig, Erika; Wedrich, Andreas; Hofmann-Wellenhof, Rainer; Zalaudek, Iris

    2016-01-01

    Pigmented cells are derived from neural crest cells, which migrate along the peripheral nerve sheets into their specific final region. During their migration, cells progressively acquire pigment-producing capabilities, maturation, and the shape of melanocytes. These insights, along with specific clinical characteristics of melanocytic nevi, have led to new concepts of cutaneous, periocular, and iris nevogenesis. To further elucidate the specific ocular embryogenic melanoblast distribution and dissemination - that could explain the distinct distribution of uveal melanocytic neoplasms - we investigated the ocular pigmentation of dogs affected by a specific mutation called Merle, which results in either pigment- (wild type) or non-pigment- (mutated type) producing cells. Based on our observations, we propose a unifying concept of uveal pigment cell distribution and dissemination, which postulates melanoblast migration and maturation following the trigeminal V1 branch and, later, their entrance into the eye along the ciliary nerves and their finest iris branches. Our concept provides an explanation not only for the specific distribution of ocular melanocytic lesions, including uveal and iris nevi, but also for the different locations depending on the metastatic potential of the ocular melanoma. Though speculative, the higher metastatic potential of posterior uveal melanomas compared to iris melanomas may be related to a less differentiated stage in the maturation of migrating melanocytes in the posterior segment compared to the anterior segment of the eye. However, there is a need of further studies focusing on cell differentiation markers of melanocytes at different locations in the eye. PMID:27002320

  15. The PBDE metabolite 6-OH-BDE 47 affects melanin pigmentation and THRβ MRNA expression in the eye of zebrafish embryos

    PubMed Central

    Dong, Wu; Macaulay, Laura J; Kwok, Kevin WH; Hinton, David E; Ferguson, P Lee; Stapleton, Heather M

    2015-01-01

    Polybrominated diphenyl ethers and their hydroxyl-metabolites (OH-BDEs) are commonly detected contaminants in human serum in the US population. They are also considered to be endocrine disruptors, and are specifically known to affect thyroid hormone regulation. In this study, we investigated and compared the effects of a PBDE and its OH-BDE metabolite on developmental pathways regulated by thyroid hormones using zebrafish as a model. Exposure to 6-OHBDE 47 (10–100 nM), but not BDE 47 (1–50 μM), led to decreased melanin pigmentation and increased apoptosis in the retina of zebrafish embryos in a concentration-dependent manner in short-term exposures (4 – 30 hours). Six-OH-BDE 47 exposure also significantly decreased thyroid hormone receptor β (THRβ) mRNA expression, which was confirmed using both RT-PCR and in situ hybridization (whole mount and paraffin- section). Interestingly, exposure to the native thyroid hormone, triiodothyronine (T3) also led to similar responses: decreased THRβ mRNA expression, decreased melanin pigmentation and increased apoptosis, suggesting that 6-OH-BDE 47 may be acting as a T3 mimic. To further investigate short-term effects that may be regulated by THRβ, experiments using a morpholino gene knock down and THRβ mRNA over expression were conducted. Knock down of THRβ led to decreases in melanin pigmentation and increases in apoptotic cells in the eye of zebrafish embryos, similar to exposure to T3 and 6-OH-BDE 47, but THRβ mRNA overexpression rescued these effects. Histological analysis of eyes at 22 hpf from each group revealed that exposure to T3 or to 6-OH-BDE 47 was associated with a decrease of melanin and diminished proliferation of cells in layers of retina near the choroid. This study suggests that 6-OH-BDE 47 disrupts the activity of THRβ in early life stages of zebrafish, and warrants further studies on effects in developing humans. PMID:25767823

  16. Lycopene inhibits PDGF-BB-induced retinal pigment epithelial cell migration by suppression of PI3K/Akt and MAPK pathways

    SciTech Connect

    Chan, Chi-Ming; Fang, Jia-You; Lin, Hsin-Huang; Yang, Chi-Yea; Hung, Chi-Feng

    2009-10-09

    Retinal pigment epithelial (RPE) cells play a dominant role in the development of proliferative vitreoretinopathy (PVR), which is the leading cause of failure in retinal reattachment surgery. Several studies have shown that platelet-derived growth factor (PDGF) exhibits chemotaxis and proliferation effects on RPE cells in PVR. In this study, the inhibitory effect of lycopene on PDGF-BB-induced ARPE19 cell migration is examined. In electric cell-substrate impedance sensing (ECIS) and Transwell migration assays, significant suppression of PDGF-BB-induced ARPE19 cell migration by lycopene is observed. Cell viability assays show no cytotoxicity of lycopene on RPE cells. Lycopene shows no effect on ARPE19 cell adhesion and is found to inhibit PDGF-BB-induced tyrosine phosphorylation and the underlying signaling pathways of PI3K, Akt, ERK and p38 activation. However, PDGF-BB and lycopene show no effects on JNK activation. Taken together, our results demonstrate that lycopene inhibits PDGF-BB-induced ARPE19 cell migration through inhibition of PI3K/Akt, ERK and p38 activation.

  17. TNF-{alpha} promotes human retinal pigment epithelial (RPE) cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression through activation of Akt/mTORC1 signaling

    SciTech Connect

    Wang, Cheng-hu; Cao, Guo-Fan; Jiang, Qin; Yao, Jin

    2012-08-17

    Highlights: Black-Right-Pointing-Pointer TNF-{alpha} induces MMP-9 expression and secretion to promote RPE cell migration. Black-Right-Pointing-Pointer MAPK activation is not critical for TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer Akt and mTORC1 signaling mediate TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer SIN1 knockdown showed no significant effect on MMP-9 expression by TNF-{alpha}. -- Abstract: Tumor necrosis factor-alpha (TNF-{alpha}) promotes in vitro retinal pigment epithelial (RPE) cell migration to initiate proliferative vitreoretinopathy (PVR). Here we report that TNF-{alpha} promotes human RPE cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression. Inhibition of MMP-9 by its inhibitor or its neutralizing antibody inhibited TNF-{alpha}-induced in vitro RPE cell migration. Reversely, exogenously-added active MMP-9 promoted RPE cell migration. Suppression Akt/mTOR complex 1(mTORC1) activation by LY 294002 and rapamycin inhibited TNF-{alpha}-mediated MMP-9 expression. To introduce a constitutively active Akt (CA-Akt) in cultured RPE cells increased MMP-9 expression, and to block mTORC1 activation by rapamycin inhibited its effect. RNA interference (RNAi)-mediated silencing of SIN1, a key component of mTOR complex 2 (mTORC2), had no effect on MMP-9 expression or secretion. In conclusion, this study suggest that TNF-{alpha} promotes RPE cell migration by inducing MMP-9 expression through activation of Akt/ mTORC1, but not mTORC2 signaling.

  18. Recurrent uveitis and pigment dispersion in an eye with in-the-bag acrylic foldable intraocular lens.

    PubMed

    Thakur, Monica; Bhatia, Prashant; Chandrasekhar, Garudadri; Senthil, Sirisha

    2016-01-01

    Phacoemulsification with in-the-bag intraocular lens (IOL) implantation is the standard procedure for cataract surgery. Pigment dispersion and uveitis can result when an IOL is placed in the sulcus. We report a case of a 64-year-old woman, with pigmentary glaucoma, who developed recurrent uveitis following uneventful cataract surgery and an in-the-bag hydrophobic acrylic IOL implant. Recurrent uveitis did not subside despite use of topical steroids over 3 months. Dilated examination revealed capsulophimosis with anterior dislocation of the IOL haptic. The mechanical trauma to the iris due to the displaced haptic was implicated as the cause of recurrent uveitis, which completely resolved after capsular excision and IOL repositioning. This case illustrates a rare cause of recurrent uveitis due to IOL haptic dislocation following severe capsulophimosis. PMID:26921366

  19. Retinal pigment epithelial cell multinucleation in the aging eye - a mechanism to repair damage and maintain homoeostasis.

    PubMed

    Chen, Mei; Rajapakse, Dinusha; Fraczek, Monika; Luo, Chang; Forrester, John V; Xu, Heping

    2016-06-01

    Retinal pigment epithelial (RPE) cells are central to retinal health and homoeostasis. Dysfunction or death of RPE cells underlies many age-related retinal degenerative disorders particularly age-related macular degeneration. During aging RPE cells decline in number, suggesting an age-dependent cell loss. RPE cells are considered to be postmitotic, and how they repair damage during aging remains poorly defined. We show that RPE cells increase in size and become multinucleate during aging in C57BL/6J mice. Multinucleation appeared not to be due to cell fusion, but to incomplete cell division, that is failure of cytokinesis. Interestingly, the phagocytic activity of multinucleate RPE cells was not different from that of mononuclear RPE cells. Furthermore, exposure of RPE cells in vitro to photoreceptor outer segment (POS), particularly oxidized POS, dose-dependently promoted multinucleation and suppressed cell proliferation. Both failure of cytokinesis and suppression of proliferation required contact with POS. Exposure to POS also induced reactive oxygen species and DNA oxidation in RPE cells. We propose that RPE cells have the potential to proliferate in vivo and to repair defects in the monolayer. We further propose that the conventionally accepted 'postmitotic' status of RPE cells is due to a modified form of contact inhibition mediated by POS and that RPE cells are released from this state when contact with POS is lost. This is seen in long-standing rhegmatogenous retinal detachment as overtly proliferating RPE cells (proliferative vitreoretinopathy) and more subtly as multinucleation during normal aging. Age-related oxidative stress may promote failure of cytokinesis and multinucleation in RPE cells. PMID:26875723

  20. Ultraviolet vision in lacertid lizards: evidence from retinal structure, eye transmittance, SWS1 visual pigment genes and behaviour.

    PubMed

    Pérez i de Lanuza, Guillem; Font, Enrique

    2014-08-15

    Ultraviolet (UV) vision and UV colour patches have been reported in a wide range of taxa and are increasingly appreciated as an integral part of vertebrate visual perception and communication systems. Previous studies with Lacertidae, a lizard family with diverse and complex coloration, have revealed the existence of UV-reflecting patches that may function as social signals. However, confirmation of the signalling role of UV coloration requires demonstrating that the lizards are capable of vision in the UV waveband. Here we use a multidisciplinary approach to characterize the visual sensitivity of a diverse sample of lacertid species. Spectral transmission measurements of the ocular media show that wavelengths down to 300 nm are transmitted in all the species sampled. Four retinal oil droplet types can be identified in the lacertid retina. Two types are pigmented and two are colourless. Fluorescence microscopy reveals that a type of colourless droplet is UV-transmitting and may thus be associated with UV-sensitive cones. DNA sequencing shows that lacertids have a functional SWS1 opsin, very similar at 13 critical sites to that in the presumed ancestral vertebrate (which was UV sensitive) and other UV-sensitive lizards. Finally, males of Podarcis muralis are capable of discriminating between two views of the same stimulus that differ only in the presence/absence of UV radiance. Taken together, these results provide convergent evidence of UV vision in lacertids, very likely by means of an independent photopigment. Moreover, the presence of four oil droplet types suggests that lacertids have a four-cone colour vision system. PMID:24902749

  1. Skin Pigment

    MedlinePlus

    ... Professional Version Pigment Disorders Overview of Skin Pigment Albinism Vitiligo Hyperpigmentation Melasma Melanin is the brown pigment ... dark-skinned people produce the most. People with albinism have little or no melanin and thus their ...

  2. Temsirolimus inhibits proliferation and migration in retinal pigment epithelial and endothelial cells via mTOR inhibition and decreases VEGF and PDGF expression.

    PubMed

    Liegl, Raffael; Koenig, Susanna; Siedlecki, Jakob; Haritoglou, Christos; Kampik, Anselm; Kernt, Marcus

    2014-01-01

    Due to their high prevalence, retinal vascular diseases including age related macular degeneration (AMD), retinal vein occlusions (RVO), diabetic retinopathy (DR) and diabetic macular edema have been major therapeutic targets over the last years. The pathogenesis of these diseases is complex and yet not fully understood. However, increased proliferation, migration and angiogenesis are characteristic cellular features in almost every retinal vascular disease. The introduction of vascular endothelial growth factor (VEGF) binding intravitreal treatment strategies has led to great advances in the therapy of these diseases. While the predominant part of affected patients benefits from the specific binding of VEGF by administering an anti-VEGF antibody into the vitreous cavity, a small number of non-responders exist and alternative or additional therapeutic strategies should therefore be evaluated. The mammalian target of rapamycin (mTOR) is a central signaling pathway that eventually triggers up-regulation of cellular proliferation, migration and survival and has been identified to play a key role in angiogenesis. In the present study we were able to show that both retinal pigment epithelial (RPE) cells as wells as human umbilical vein endothelial cells (HUVEC) are inhibited in proliferating and migrating after treatment with temsirolimus in non-toxic concentrations. Previous studies suggest that the production of VEGF, platelet derived growth factor (PDGF) and other important cytokines is not only triggered by hypoxia but also by mTOR itself. Our results indicate that temsirolimus decreases VEGF and PDGF expression on RNA and protein levels significantly. We therefore believe that the mTOR inhibitor temsirolimus might be a promising drug in the future and it seems worthwhile to evaluate complementary therapeutic effects with anti-VEGF drugs for patients not profiting from mono anti-VEGF therapy alone. PMID:24586308

  3. Silencing heme oxygenase-1 gene expression in retinal pigment epithelial cells inhibits proliferation, migration and tube formation of cocultured endothelial cells

    SciTech Connect

    Zhang, Wenjie; Zhang, Xiaomei; Lu, Hong; Matsukura, Makoto; Zhao, Jien; Shinohara, Makoto

    2013-05-10

    Highlights: •HO-1 is highly induced in RPE cells by hypoxia. •Inhibition of HO-1 activity and knockdown of HO-1 expression inhibit VEGF expression in RPE cells under hypoxia. •Knockdown of HO-1 in RPE cells inhibits angiogenesis of endothelial cells in vitro. -- Abstract: Heme oxygenase-1 (HO-1) plays an important role in the vasculature and in the angiogenesis of tumors, wounds and other environments. Retinal pigment epithelial (RPE) cells and choroidal endothelial cells (CECs) are the main cells involved in choroidal neovascularization (CNV), a process in which hypoxia plays an important role. Our aim was to evaluate the role of human RPE-cell HO-1 in the angiogenic activities of cocultured endothelial cells under hypoxia. Small interfering RNA (siRNA) for HO-1 was transfected into human RPE cell line ARPE-19, and zinc protoporphyrin (ZnPP) was used to inhibit HO-1 activity. Knockdown of HO-1 expression and inhibition of HO-1 activity resulted in potent reduction of the expression of vascular endothelial growth factor (VEGF) under hypoxia. Furthermore, knockdown of HO-1 suppressed the proliferation, migration and tube formation of cocultured endothelial cells. These findings indicated that HO-1 might have an angiogenic effect in CNV through modulation of VEGF expression and might be a potential target for treating CNV.

  4. Ion transport in pigmentation

    PubMed Central

    Bellono, Nicholas W.; Oancea, Elena V.

    2014-01-01

    Skin melanocytes and ocular pigment cells contain specialized organelles called melanosomes, which are responsible for the synthesis of melanin, the major pigment in mammals. Defects in the complex mechanisms involved in melanin synthesis and regulation result in vision and pigmentation deficits, impaired development of the visual system,, and increased susceptibility to skin and eye cancers. Ion transport across cellular membranes is critical for many biological processes, including pigmentation, but the molecular mechanisms by which it regulates melanin synthesis, storage, and transfer are not understood. In this review we first discuss ion channels and transporters that function at the plasma membrane of melanocytes; in the second part we consider ion transport across the membrane of intracellular organelles, with emphasis on melanosomes. We discuss recently characterized lysosomal and endosomal ion channels and transporters associated with pigmentation phenotypes. We then review the evidence for melanosomal channels and transporters critical for pigmentation, discussing potential molecular mechanisms mediating their function. The studies investigating ion transport in pigmentation physiology open new avenues for future research and could reveal novel molecular mechanisms underlying melanogenesis. PMID:25034214

  5. [Migration].

    PubMed

    Maccotta, W; Perotti, A; Thebaut, F; Cristofanelli, L; Pittau, F; Sergi, N; Pittau, L; Morelli, A; Morsella, M; Grinover, A P

    1990-01-01

    This is a collection of 11 individual articles on aspects of current migration problems affecting developed countries. The geographical focus is on immigration in Europe, with particular reference to Italy, although one paper is concerned with Quebec. The topical focus is on the social problems associated with immigration. The articles are in Italian, with one exception, which is in French. PMID:12343393

  6. Pigmented casts.

    PubMed

    Miteva, Mariya; Romanelli, Paolo; Tosti, Antonella

    2014-01-01

    Pigmented casts have been reported with variable frequency in scalp biopsies from alopecia areata, trichotillomania, chemotherapy-induced alopecia and postoperative (pressure induced) alopecia. Their presence and morphology in other scalp disorders has not been described. The authors assessed for the presence and morphology of pigmented casts in 308 transversely bisected scalp biopsies from nonscarring and scarring alopecia, referred to the Department of Dermatology, University of Miami within a year. The pigmented casts were present in 21 of 29 cases of alopecia areata (72%), 7 of 7 cases of trichotillomania (100%), 1 case of friction alopecia, 4 of 28 cases of central centrifugal cicatricial alopecia (14%), and 4 of 4 cases of dissecting cellulitis (100%). They did not show any distinguishing features except for the morphology in trichotillomania, which included twisted, linear (zip), and "button"-like pigment aggregation. The linear arrangement was found also in friction alopecia and dissecting cellulitis. Pigmented casts in the hair canals of miniaturized/vellus hairs was a clue to alopecia areata. Pigmented casts can be observed in biopsies of different hair disorders, but they are not specific for the diagnosis. Horizontal sections allow to better assess their morphology and the follicular level of presence of pigmented casts, which in the context of the other follicular findings may be a clue to the diagnosis. PMID:23823025

  7. Reconstructing the eyes of Urbilateria.

    PubMed Central

    Arendt, D; Wittbrodt, J

    2001-01-01

    The shared roles of Pax6 and Six homologues in the eye development of various bilaterians suggest that Urbilateria, the common ancestors of all Bilateria, already possessed some simple form of eyes. Here, we re-address the homology of bilaterian cerebral eyes at the level of eye anatomy, of eye-constituting cell types and of phototransductory molecules. The most widespread eye type found in Bilateria are the larval pigment-cup eyes located to the left and right of the apical organ in primary, ciliary larvae of Protostomia and Deuterostomia. They can be as simple as comprising a single pigment cell and a single photoreceptor cell in inverse orientation. Another more elaborate type of cerebral pigment-cup eyes with an everse arrangement of photoreceptor cells is found in adult Protostomia. Both inverse larval and everse adult eyes employ rhabdomeric photoreceptor cells and thus differ from the chordate cerebral eyes with ciliary photoreceptors. This is highly significant because on the molecular level we find that for phototransduction rhabdomeric versus ciliary photoreceptor cells employ divergent rhodopsins and non-orthologous G-proteins, rhodopsin kinases and arrestins. Our comparison supports homology of cerebral eyes in Protostomia; it challenges, however, homology of chordate and non-chordate cerebral eyes that employ photoreceptor cells with non-orthologous phototransductory cascades. PMID:11604122

  8. Migration of 18 trace elements from ceramic food contact material: influence of pigment, pH, nature of acid and temperature.

    PubMed

    Demont, M; Boutakhrit, K; Fekete, V; Bolle, F; Van Loco, J

    2012-03-01

    The effect of pH, nature of acid and temperature on trace element migration from ceramic ware treated with 18 commercially available glazes was studied. Besides of the well-studied lead and cadmium, migration of other toxic and non toxic elements such as aluminum, boron, barium, cobalt, chrome, copper, iron, lithium, magnesium, manganese, nickel, antimony, tin, strontium, titanium, vanadium, zinc and zirconium was investigated in order to evaluate their potential health hazards. Trace element concentrations were determined with Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). This study suggests that there is indeed a health risk concerning the possible migration of other elements than lead and cadmium. At low pH (2migration kinetics between pH 2 and 3 in acetic acid of these exceptions also are more exponential while the other elements display a decreasing linear gradient. In ceramics used for this study (fired at 900 °C), a linear relationship between the migration and the temperature was observed. PMID:22265939

  9. Birthmarks - pigmented

    MedlinePlus

    ... its own appearance: Cafe-au-lait spots are light tan, the color of coffee with milk. Moles are small clusters of colored skin cells. Mongolian spots (also called Mongolian blue ... dark or light skin Growth of hair from pigmented skin Skin ...

  10. Pigment epithelium-derived factor (PEDF) and vascular endothelial growth factor (VEGF) in aged human choroid and eyes with age-related macular degeneration

    PubMed Central

    Bhutto, Imran A.; McLeod, D. Scott; Hasegawa, Takuya; Kim, Sahng Y.; Merges, Carol; Tong, Patrick; Lutty, Gerard A.

    2016-01-01

    The purpose of this study was to examine the localization and relative levels of vascular endothelial growth factor (VEGF; an angiogenic factor) and pigment epithelium-derived factor (PEDF; an antiangiogenic factor) in aged human choroid and to determine if the localization or their relative levels changed in age-related macular degeneration (AMD). Ocular tissues were obtained from eight aged control donors (age range, 75–86 years; mean age, 79.8 years) with no evidence or history of chorioretinal disease and from 12 donors diagnosed with AMD (age range, 61–105 years; mean age, 83.9 years). Tissues were cryopreserved and streptavidin alkaline phosphatase immunohistochemistry was performed with rabbit polyclonal anti-human VEGF and rabbit polyclonal anti-human PEDF antibodies. Binding of the antibodies was blocked by preincubation of the antibody with an excess of recombinant human PEDF or VEGF peptide. Choroidal blood vessels were identified with mouse anti-human CD-34 antibody in adjacent tissue sections. Three independent observers graded the immunohistochemical reaction product. The most prominent sites of VEGF and PEDF localization in aged control choroid were RPE–Bruch’s membrane–choriocapillaris complex including RPE basal lamina, intercapillary septa, and choroidal stroma. There was no significant difference in immunostaining intensity and localization of VEGF and PEDF in aged control choroids. The most intense VEGF immunoreactivity was observed in leukocytes within blood vessels. AMD choroid had a similar pattern and intensity of VEGF immunostaining to that observed in aged controls. However, PEDF immunoreactivity was significantly lower in RPE cells (p = 0.0073), RPE basal lamina (p = 0.0141), Bruch’s membrane (p < 0.0001), and choroidal stroma (p = 0.0161) of AMD choroids. The most intense PEDF immunoreactivity was observed in disciform scars. Drusen and basal laminar deposits (BLDs) were positive for VEGF and PEDF. In aged control subjects

  11. Skin as a living coloring book: how epithelial cells create patterns of pigmentation.

    PubMed

    Weiner, Lorin; Fu, Wenyu; Chirico, William J; Brissette, Janice L

    2014-11-01

    The pigmentation of mammalian skin and hair develops through the interaction of two basic cell types - pigment donors and recipients. The pigment donors are melanocytes, which produce and distribute melanin through specialized structures. The pigment recipients are epithelial cells, which acquire melanin and put it to use, collectively yielding the pigmentation visible to the eye. This review will focus on the pigment recipients, the historically less understood cell type. These end-users of pigment are now known to exert a specialized control over the patterning of pigmentation, as they identify themselves as melanocyte targets, recruit pigment donors, and stimulate the transfer of melanin. As such, this review will discuss the evidence that the skin is like a coloring book: the pigment recipients create a 'picture,' a blueprint for pigmentation, which is colorless initially but outlines where pigment should be placed. Melanocytes then melanize the recipients and 'color in' the picture. PMID:25104547

  12. SKIN AS A LIVING COLORING BOOK: HOW EPITHELIAL CELLS CREATE PATTERNS OF PIGMENTATION

    PubMed Central

    Weiner, Lorin; Fu, Wenyu; Chirico, William J.; Brissette, Janice L.

    2014-01-01

    Summary The pigmentation of mammalian skin and hair develops through the interaction of two basic cell types — pigment donors and recipients. The pigment donors are melanocytes, which produce and distribute melanin through specialized structures. The pigment recipients are epithelial cells, which acquire melanin and put it to use, collectively yielding the pigmentation visible to the eye. This review will focus on the pigment recipients, the historically less understood cell type. These end-users of pigment are now known to exert a specialized control over the patterning of pigmentation, as they identify themselves as melanocyte targets, recruit pigment donors, and stimulate the transfer of melanin. As such, this review will discuss the evidence that the skin is like a coloring book: the pigment recipients create a “picture,” a blueprint for pigmentation, which is colorless initially but outlines where pigment should be placed. Melanocytes then melanize the recipients and “color in” the picture. PMID:25104547

  13. Skin Pigmentation Disorders

    MedlinePlus

    Pigmentation means coloring. Skin pigmentation disorders affect the color of your skin. Your skin gets its color from a pigment called melanin. Special cells in the skin make melanin. When these cells become damaged or ...

  14. Relation of the fractal structure of organic pigments to their performance

    NASA Astrophysics Data System (ADS)

    Skillas, G.; Agashe, N.; Kohls, D. J.; Ilavsky, J.; Jemian, P.; Clapp, L.; Schwartz, R. J.; Beaucage, G.

    2002-05-01

    Different pigments embedded in polymer matrices were examined by small angle scattering of x- rays over 3 wave number decades. The scattering intensities show differences both in the mass fractal dimension (varying between 1.4 and 2.67) and the size of the particles. The differences are pronounced between dry pigment powders and the same powders in a polymer matrix as well as between the pigments themselves. Further, a correlation of pigment geometrical configuration and pigment performance, as perceived by the human eye, shows how pigments with a maximum color brightness per pigment mass can be created.

  15. Eye Infections

    MedlinePlus

    Your eyes can get infections from bacteria, fungi, or viruses. Eye infections can occur in different parts of the eye and can affect just one eye or both. Two common eye infections are Conjunctivitis - also known as pinkeye. Conjunctivitis is ...

  16. Human pigmentation genes under environmental selection

    PubMed Central

    2012-01-01

    Genome-wide association studies and comparative genomics have established major loci and specific polymorphisms affecting human skin, hair and eye color. Environmental changes have had an impact on selected pigmentation genes as populations have expanded into different regions of the globe. PMID:23110848

  17. Reversible Conjunctival Pigmentation Associated With Prostaglandin Use.

    PubMed

    Choi, Daniel Y; Chang, Robert T; Yegnashankaran, Krishnan; Friedman, Neil J

    2016-01-01

    A 54-year-old Indian male with a diagnosis of ocular hypertension was started on a prostaglandin analog (PGA) in both eyes to lower intraocular pressure. Six years later, he developed progressively increasing bilateral limbal conjunctival hyperpigmentation. Travoprost was discontinued and replaced with brinzolamide and over the next year, the patient's conjunctival pigmentation improved significantly in both the eyes. This case report documents with slit-lamp photography the first case of conjunctival pigmentation associated with PGA use that has been shown to have reversal with discontinuation of the PGA. Because of the widespread use of PGAs, and the evolving nature of the conjunctival pigmentation, clinicians should be aware of this reversible condition when considering biopsy or removal of conjunctival melanocytic lesions. PMID:25967530

  18. Predicting phenotype from genotype: normal pigmentation.

    PubMed

    Valenzuela, Robert K; Henderson, Miquia S; Walsh, Monica H; Garrison, Nanibaa' A; Kelch, Jessica T; Cohen-Barak, Orit; Erickson, Drew T; John Meaney, F; Bruce Walsh, J; Cheng, Keith C; Ito, Shosuke; Wakamatsu, Kazumasa; Frudakis, Tony; Thomas, Matthew; Brilliant, Murray H

    2010-03-01

    Genetic information in forensic studies is largely limited to CODIS data and the ability to match samples and assign them to an individual. However, there are circumstances, in which a given DNA sample does not match anyone in the CODIS database, and no other information about the donor is available. In this study, we determined 75 SNPs in 24 genes (previously implicated in human or animal pigmentation studies) for the analysis of single- and multi-locus associations with hair, skin, and eye color in 789 individuals of various ethnic backgrounds. Using multiple linear regression modeling, five SNPs in five genes were found to account for large proportions of pigmentation variation in hair, skin, and eyes in our across-population analyses. Thus, these models may be of predictive value to determine an individual's pigmentation type from a forensic sample, independent of ethnic origin. PMID:20158590

  19. Transcriptome analysis of the planarian eye identifies ovo as a specific regulator of eye regeneration

    PubMed Central

    Lapan, Sylvain W.; Reddien, Peter W.

    2013-01-01

    Summary Among the millions of invertebrate species with visual systems, the genetic basis of eye development and function is well understood only in Drosophila melanogaster. We describe an eye transcriptome for the planarian Schmidtea mediterranea. Planarian photoreceptors expressed orthologs of genes required for phototransduction and microvillus structure in Drosophila and vertebrates, and optic pigment cells expressed solute transporters and melanin synthesis enzymes similar to those active in the vertebrate retinal pigment epithelium. Orthologs of several planarian eye genes, such as bestrophin-1 and Usher syndrome genes, cause eye defects in mammals when perturbed and were not previously described to have roles in invertebrate eyes. Five previously undescribed planarian eye transcription factors were required for normal eye formation during head regeneration. In particular, a conserved, transcription factor-encoding ovo gene was expressed from the earliest stages of eye regeneration and was required for regeneration of all cell types of the eye. PMID:22884275

  20. A melanosomal two-pore sodium channel regulates pigmentation.

    PubMed

    Bellono, Nicholas W; Escobar, Iliana E; Oancea, Elena

    2016-01-01

    Intracellular organelles mediate complex cellular functions that often require ion transport across their membranes. Melanosomes are organelles responsible for the synthesis of the major mammalian pigment melanin. Defects in melanin synthesis result in pigmentation defects, visual deficits, and increased susceptibility to skin and eye cancers. Although genes encoding putative melanosomal ion transporters have been identified as key regulators of melanin synthesis, melanosome ion transport and its contribution to pigmentation remain poorly understood. Here we identify two-pore channel 2 (TPC2) as the first reported melanosomal cation conductance by directly patch-clamping skin and eye melanosomes. TPC2 has been implicated in human pigmentation and melanoma, but the molecular mechanism mediating this function was entirely unknown. We demonstrate that the vesicular signaling lipid phosphatidylinositol bisphosphate PI(3,5)P2 modulates TPC2 activity to control melanosomal membrane potential, pH, and regulate pigmentation. PMID:27231233

  1. A melanosomal two-pore sodium channel regulates pigmentation

    PubMed Central

    Bellono, Nicholas W.; Escobar, Iliana E.; Oancea, Elena

    2016-01-01

    Intracellular organelles mediate complex cellular functions that often require ion transport across their membranes. Melanosomes are organelles responsible for the synthesis of the major mammalian pigment melanin. Defects in melanin synthesis result in pigmentation defects, visual deficits, and increased susceptibility to skin and eye cancers. Although genes encoding putative melanosomal ion transporters have been identified as key regulators of melanin synthesis, melanosome ion transport and its contribution to pigmentation remain poorly understood. Here we identify two-pore channel 2 (TPC2) as the first reported melanosomal cation conductance by directly patch-clamping skin and eye melanosomes. TPC2 has been implicated in human pigmentation and melanoma, but the molecular mechanism mediating this function was entirely unknown. We demonstrate that the vesicular signaling lipid phosphatidylinositol bisphosphate PI(3,5)P2 modulates TPC2 activity to control melanosomal membrane potential, pH, and regulate pigmentation. PMID:27231233

  2. Eye redness

    MedlinePlus

    Bloodshot eyes; Red eyes; Scleral infection; Conjunctival infection ... There are many causes of a red eye or eyes. Some are medical emergencies and some are a cause for concern, but not an emergency. Others are nothing to worry about. ...

  3. Eye Cancer

    MedlinePlus

    ... Eye Cancer - Overview Request Permissions Print to PDF Eye Cancer - Overview Approved by the Cancer.Net Editorial Board , ... Cancer Research and Advocacy Survivorship Blog About Us Eye Cancer Guide Cancer.Net Guide Eye Cancer Overview Statistics ...

  4. Eye emergencies

    MedlinePlus

    ... Trauma A black eye is usually caused by direct trauma to the eye or face. The bruise ... can cause bruising around the eyes, even without direct injury to the eye. Sometimes, serious damage to ...

  5. Eye pain

    MedlinePlus

    Ophthalmalgia; Pain - eye ... Pain in the eye can be an important symptom of a health problem. Make sure you tell your health care provider if you have eye pain that does not go away. Tired eyes or ...

  6. Effects of exogenous thyroid hormones on visual pigment composition in coho salmon (Oncorhynchus kisutch).

    PubMed

    Temple, Shelby E; Ramsden, Samuel D; Haimberger, Theodore J; Veldhoen, Kathy M; Veldhoen, Nik J; Carter, Nicolette L; Roth, Wolff-Michael; Hawryshyn, Craig W

    2008-07-01

    The role of exogenous thyroid hormone on visual pigment content of rod and cone photoreceptors was investigated in coho salmon (Oncorhynchus kisutch). Coho vary the ratio of vitamin A1- and A2-based visual pigments in their eyes. This variability potentially alters spectral sensitivity and thermal stability of the visual pigments. We tested whether the direction of shift in the vitamin A1/A2 ratio, resulting from application of exogenous thyroid hormone, varied in fish of different ages and held under different environmental conditions. Changes in the vitamin A1/A2 visual pigment ratio were estimated by measuring the change in maximum absorbance (lambda max) of rods using microspectrophotometry (MSP). Exogenous thyroid hormone resulted in a long-wavelength shift in rod, middle-wavelength-sensitive (MWS) and long-wavelength-sensitive (LWS) cone photoreceptors. Rod and LWS cone lambda max values increased, consistent with an increase in vitamin A2. MWS cone lambda max values increased more than predicted for a change in the vitamin A1/A2 ratio. To account for this shift, we tested for the expression of multiple RH2 opsin subtypes. We isolated and sequenced a novel RH2 opsin subtype, which had 48 amino acid differences from the previously sequenced coho RH2 opsin. A substitution of glutamate for glutamine at position 122 could partially account for the greater than predicted shift in MWS cone lambda max values. Our findings fit the hypothesis that a variable vitamin A1/A2 ratio provides seasonality in spectral tuning and/or improved thermal stability of visual pigments in the face of seasonal environmental changes, and that multiple RH2 opsin subtypes can provide flexibility in spectral tuning associated with migration-metamorphic events. PMID:18552303

  7. Skin Pigmentation Disorders

    MedlinePlus

    ... skin gets its color from a pigment called melanin. Special cells in the skin make melanin. When these cells become damaged or unhealthy, it affects melanin production. Some pigmentation disorders affect just patches of ...

  8. Oral pigmentation: A review

    PubMed Central

    Sreeja, C.; Ramakrishnan, K.; Vijayalakshmi, D.; Devi, M.; Aesha, I.; Vijayabanu, B.

    2015-01-01

    Pigmentations are commonly found in the mouth. They represent in various clinical patterns that can range from just physiologic changes to oral manifestations of systemic diseases and malignancies. Color changes in the oral mucosa can be attributed to the deposition of either endogenous or exogenous pigments as a result of various mucosal diseases. The various pigmentations can be in the form of blue/purple vascular lesions, brown melanotic lesions, brown heme-associated lesions, gray/black pigmentations. PMID:26538887

  9. Overview of plant pigments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorophylls, carotenoids, flavonoids and betalains are four major classes of biological pigments produced in plants. Chlorophylls are the primary pigments responsible for plant green and photosynthesis. The other three are accessary pigments and secondary metabolites that yield non-green colors and...

  10. Is the Schwabe Organ a Retained Larval Eye? Anatomical and Behavioural Studies of a Novel Sense Organ in Adult Leptochiton asellus (Mollusca, Polyplacophora) Indicate Links to Larval Photoreceptors.

    PubMed

    Sumner-Rooney, Lauren H; Sigwart, Julia D

    2015-01-01

    The discovery of a sensory organ, the Schwabe organ, was recently reported as a unifying feature of chitons in the order Lepidopleurida. It is a patch of pigmented tissue located on the roof of the pallial cavity, beneath the velum on either side of the mouth. The epithelium is densely innervated and contains two types of potential sensory cells. As the function of the Schwabe organ remains unknown, we have taken a cross-disciplinary approach, using anatomical, histological and behavioural techniques to understand it. In general, the pigmentation that characterises this sensory structure gradually fades after death; however, one particular concentrated pigment dot persists. This dot is positionally homologous to the larval eye in chiton trochophores, found in the same neuroanatomical location, and furthermore the metamorphic migration of the larval eye is ventral in species known to possess Schwabe organs. Here we report the presence of a discrete subsurface epithelial structure in the region of the Schwabe organ in Leptochiton asellus that histologically resembles the chiton larval eye. Behavioural experiments demonstrate that Leptochiton asellus with intact Schwabe organs actively avoid an upwelling light source, while Leptochiton asellus with surgically ablated Schwabe organs and a control species lacking the organ (members of the other extant order, Chitonida) do not (Kruskal-Wallis, H = 24.82, df = 3, p < 0.0001). We propose that the Schwabe organ represents the adult expression of the chiton larval eye, being retained and elaborated in adult lepidopleurans. PMID:26366861

  11. Is the Schwabe Organ a Retained Larval Eye? Anatomical and Behavioural Studies of a Novel Sense Organ in Adult Leptochiton asellus (Mollusca, Polyplacophora) Indicate Links to Larval Photoreceptors

    PubMed Central

    Sumner-Rooney, Lauren H.; Sigwart, Julia D.

    2015-01-01

    The discovery of a sensory organ, the Schwabe organ, was recently reported as a unifying feature of chitons in the order Lepidopleurida. It is a patch of pigmented tissue located on the roof of the pallial cavity, beneath the velum on either side of the mouth. The epithelium is densely innervated and contains two types of potential sensory cells. As the function of the Schwabe organ remains unknown, we have taken a cross-disciplinary approach, using anatomical, histological and behavioural techniques to understand it. In general, the pigmentation that characterises this sensory structure gradually fades after death; however, one particular concentrated pigment dot persists. This dot is positionally homologous to the larval eye in chiton trochophores, found in the same neuroanatomical location, and furthermore the metamorphic migration of the larval eye is ventral in species known to possess Schwabe organs. Here we report the presence of a discrete subsurface epithelial structure in the region of the Schwabe organ in Leptochiton asellus that histologically resembles the chiton larval eye. Behavioural experiments demonstrate that Leptochiton asellus with intact Schwabe organs actively avoid an upwelling light source, while Leptochiton asellus with surgically ablated Schwabe organs and a control species lacking the organ (members of the other extant order, Chitonida) do not (Kruskal-Wallis, H = 24.82, df = 3, p < 0.0001). We propose that the Schwabe organ represents the adult expression of the chiton larval eye, being retained and elaborated in adult lepidopleurans. PMID:26366861

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

    PubMed Central

    Fronk, Aaron H; Vargis, Elizabeth

    2016-01-01

    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. PMID:27493715

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

    PubMed

    Fronk, Aaron H; Vargis, Elizabeth

    2016-01-01

    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. PMID:27493715

  14. Retinal pigment epithelium in incontinentia pigmenti.

    PubMed

    Mensheha-Manhart, O; Rodrigues, M M; Shields, J A; Shannon, G M; Mirabelli, R P

    1975-04-01

    An 18-month-old white girl with incontinentia pigmenti presented clinically with leukokoria of the right eye. B-scan ultrasound demonstrated a retrolental mass consistent with a detached retina. Histologic examination of the skin revealed changes compatible with the intermediate verrucous phase of the disease. Microscopic examination of the right eye showed retinal detachment and nodular proliferation of the retinal pigment epithelium. The nodules contained macrophages laden with melanin and lipofuscin. An unusually large amount of lipofuscin was present for a child of this age. The basic pigmentary abnormality may affect the retinal pigment epithelium, resulting in changes in the overlying neurosensory retina that may lead to the retinal dysplasia or retinal detachemnt often associated with this condition. PMID:1119517

  15. Eye Emergencies

    MedlinePlus

    ... Emergencies Cardiac Emergencies Eye Emergencies Lung Emergencies Surgeries Eye Emergencies Marfan syndrome significantly increases your risk of ... light-sensitive membrane in the back of the eye (the retina) from its supporting layers. It is ...

  16. Eye Wear

    MedlinePlus

    Eye wear protects or corrects your vision. Examples are Sunglasses Safety goggles Glasses (also called eyeglasses) Contact ... jobs and some sports carry a risk of eye injury. Thousands of children and adults get eye ...

  17. Eye Injuries

    MedlinePlus

    The structure of your face helps protect your eyes from injury. Still, injuries can damage your eye, sometimes severely enough that you could lose your vision. Most eye injuries are preventable. If you play sports or ...

  18. Eye Cancer

    MedlinePlus

    Cancer of the eye is uncommon. It can affect the outer parts of the eye, such as the eyelid, which are made up ... adults are melanoma and lymphoma. The most common eye cancer in children is retinoblastoma, which starts in ...

  19. Eye Diseases

    MedlinePlus

    ... the back of the eye Macular degeneration - a disease that destroys sharp, central vision Diabetic eye problems ... defense is to have regular checkups, because eye diseases do not always have symptoms. Early detection and ...

  20. Eye Injuries

    MedlinePlus

    ... of your face helps protect your eyes from injury. Still, injuries can damage your eye, sometimes severely enough that you could lose your vision. Most eye injuries are preventable. If you play sports or work ...

  1. Argon Laser Photoablation for Treating Benign Pigmented Conjunctival Nevi

    PubMed Central

    Alsharif, Abdulrahman M.; Al-Gehedan, Saeed M.; Alasbali, Tariq; Alkuraya, Hisham S.; Lotfy, Nancy M.; Khandekar, Rajiv

    2016-01-01

    Purpose: To evaluate the outcomes of argon laser photoablation of benign conjunctival pigmented nevi with different clinical presentations. Patients and Methods: This interventional case series was conducted between July 2014 and January 2015. Patients presenting with benign conjunctival nevi were included. Data were collected on the clinical features at presentation, argon laser photoablation, and follow-up at 8 and 24 weeks. Postoperative photography allowed recording of the success of each case and the overall success rate. Complete removal of conjunctival pigments was considered an absolute success. Partial pigmentation requiring repeat laser treatment was considered a qualified success. Results: There were 14 eyes (four right eyes and ten left eyes) with benign pigmented conjunctival nevi. There were three males and eight females in the study sample. The median age was 36 (25% percentile: 26 years). Three patients had bilateral lesions. The nevi were located temporally in nine eyes, nasally in three eyes, and on the inferior bulbar conjunctiva in two eyes. The mean horizontal and vertical diameters of nevi were 5 ± 2 mm and 4 ± 2.7 mm, respectively. The mean follow-up period was 5 months. Following laser treatment, no eyes had subconjunctival hemorrhage, infection, scarring, neovascularization, recurrence, or corneal damage. The absolute success rate of laser ablation was 79%. Three eyes with elevated nevi had one to three sessions of laser ablation resulting in a qualified success rate of 100%. Conclusions: Argon laser ablation was a safe and effective treatment for the treatment of selective benign pigmented conjunctival nevi in Arab patients. PMID:27555708

  2. Abnormalities of fundus autofluorescence in pigmented paravenous chorioretinal atrophy.

    PubMed

    Hashimoto, Yuki; Kase, Satoru; Saito, Wataru; Ishida, Susumu

    2012-01-01

    The aim of this study is to investigate fundus autofluorescence (FAF) as well as fluorescein angiography (FA), indocyanine green angiography (IA), and optical coherence tomography (OCT) in a patient with pigmented paravenous chorioretinal atrophy (PPCRA). A funduscopic examination revealed chorioretinal atrophy along the paravenous area in both eyes. A marked bone spicule pigment clumping together with the atrophy was noted left eye. FA and IA showed a window defect and hypofluorescence, respectively, which exclusively corresponds to the atrophic area along the retinal vein area and the optic disc both eyes. FAF revealed geographic hypofluorescence along the paravenous and supranasal retinal areas. Hyperfluorescence was noted, which comparatively surrounded the hypofluorescence in the peripheral paravenous distribution. Hypofluorescence detected by FAF corresponded to the areas of retinal thinning and atrophy detected by OCT and FA. FAF is a useful examination in PPCRA, which can noninvasively demonstrate the distribution of deficit and dysfunction of retinal pigment epithelium. PMID:23264840

  3. An intracellular anion channel critical for pigmentation

    PubMed Central

    Bellono, Nicholas W; Escobar, Iliana E; Lefkovith, Ariel J; Marks, Michael S; Oancea, Elena

    2014-01-01

    Intracellular ion channels are essential regulators of organellar and cellular function, yet the molecular identity and physiological role of many of these channels remains elusive. In particular, no ion channel has been characterized in melanosomes, organelles that produce and store the major mammalian pigment melanin. Defects in melanosome function cause albinism, characterized by vision and pigmentation deficits, impaired retinal development, and increased susceptibility to skin and eye cancers. The most common form of albinism is caused by mutations in oculocutaneous albinism II (OCA2), a melanosome-specific transmembrane protein with unknown function. Here we used direct patch-clamp of skin and eye melanosomes to identify a novel chloride-selective anion conductance mediated by OCA2 and required for melanin production. Expression of OCA2 increases organelle pH, suggesting that the chloride channel might regulate melanin synthesis by modulating melanosome pH. Thus, a melanosomal anion channel that requires OCA2 is essential for skin and eye pigmentation. DOI: http://dx.doi.org/10.7554/eLife.04543.001 PMID:25513726

  4. An intracellular anion channel critical for pigmentation.

    PubMed

    Bellono, Nicholas W; Escobar, Iliana E; Lefkovith, Ariel J; Marks, Michael S; Oancea, Elena

    2014-01-01

    Intracellular ion channels are essential regulators of organellar and cellular function, yet the molecular identity and physiological role of many of these channels remains elusive. In particular, no ion channel has been characterized in melanosomes, organelles that produce and store the major mammalian pigment melanin. Defects in melanosome function cause albinism, characterized by vision and pigmentation deficits, impaired retinal development, and increased susceptibility to skin and eye cancers. The most common form of albinism is caused by mutations in oculocutaneous albinism II (OCA2), a melanosome-specific transmembrane protein with unknown function. Here we used direct patch-clamp of skin and eye melanosomes to identify a novel chloride-selective anion conductance mediated by OCA2 and required for melanin production. Expression of OCA2 increases organelle pH, suggesting that the chloride channel might regulate melanin synthesis by modulating melanosome pH. Thus, a melanosomal anion channel that requires OCA2 is essential for skin and eye pigmentation. PMID:25513726

  5. Iris pigment epithelial cysts in a newborn

    PubMed Central

    Zargar, Shabnam; Prendiville, Kevin John; Martinez, Eladio

    2016-01-01

    Purpose: We report a case of iris pigment epithelial cysts in a newborn and discuss the importance of an accurate diagnosis for prevention of amblyopia. Methods: We describe a case of an abnormal red reflex seen on a newborn exam. Results: A full-term female born via normal spontaneous vaginal delivery without any complications was seen in the newborn nursery. She was noted to have an abnormal eye exam. Pupils were large with circular dark excrescences of the iris pigment epithelium. She was referred to a pediatric ophthalmologist where she was noted to fixate and follow faces. No afferent pupillary defect was seen. OD red reflex was normal whereas OS red reflex was blocked mostly by dark excrescences. A 2–3 mm dark brown lesion was seen in the OD iris and a 3–5 mm dark brown lesion was seen in the OS iris, consistent with a pupillary iris pigment epithelial cyst. Central visual axis was clear OU. Glaucoma was not present and patching was not performed. Observations and clinical photographs were recommended with follow-up in three months. Conclusion: Iris pigment epithelial cysts are uncommonly seen in children. The primary care provider first seeing a newborn must be aware of lesions obscuring a red reflex with appropriate follow-up. Follow-up in three months with IOP measurements is recommended. Iris pigment epithelial cysts in children may be a cause of amblyopia, thus prompt evaluation is important for prognostic purposes and the prevention of amblyopia. PMID:27625966

  6. Positive selection of a duplicated UV-sensitive visual pigment coincides with wing pigment evolution in Heliconius butterflies.

    PubMed

    Briscoe, Adriana D; Bybee, Seth M; Bernard, Gary D; Yuan, Furong; Sison-Mangus, Marilou P; Reed, Robert D; Warren, Andrew D; Llorente-Bousquets, Jorge; Chiao, Chuan-Chin

    2010-02-23

    The butterfly Heliconius erato can see from the UV to the red part of the light spectrum with color vision proven from 440 to 640 nm. Its eye is known to contain three visual pigments, rhodopsins, produced by an 11-cis-3-hydroxyretinal chromophore together with long wavelength (LWRh), blue (BRh) and UV (UVRh1) opsins. We now find that H. erato has a second UV opsin mRNA (UVRh2)-a previously undescribed duplication of this gene among Lepidoptera. To investigate its evolutionary origin, we screened eye cDNAs from 14 butterfly species in the subfamily Heliconiinae and found both copies only among Heliconius. Phylogeny-based tests of selection indicate positive selection of UVRh2 following duplication, and some of the positively selected sites correspond to vertebrate visual pigment spectral tuning residues. Epi-microspectrophotometry reveals two UV-absorbing rhodopsins in the H. erato eye with lambda(max) = 355 nm and 398 nm. Along with the additional UV opsin, Heliconius have also evolved 3-hydroxy-DL-kynurenine (3-OHK)-based yellow wing pigments not found in close relatives. Visual models of how butterflies perceive wing color variation indicate this has resulted in an expansion of the number of distinguishable yellow colors on Heliconius wings. Functional diversification of the UV-sensitive visual pigments may help explain why the yellow wing pigments of Heliconius are so colorful in the UV range compared to the yellow pigments of close relatives lacking the UV opsin duplicate. PMID:20133601

  7. Positive selection of a duplicated UV-sensitive visual pigment coincides with wing pigment evolution in Heliconius butterflies

    PubMed Central

    Briscoe, Adriana D.; Bybee, Seth M.; Bernard, Gary D.; Yuan, Furong; Sison-Mangus, Marilou P.; Reed, Robert D.; Warren, Andrew D.; Llorente-Bousquets, Jorge; Chiao, Chuan-Chin

    2010-01-01

    The butterfly Heliconius erato can see from the UV to the red part of the light spectrum with color vision proven from 440 to 640 nm. Its eye is known to contain three visual pigments, rhodopsins, produced by an 11-cis-3-hydroxyretinal chromophore together with long wavelength (LWRh), blue (BRh) and UV (UVRh1) opsins. We now find that H. erato has a second UV opsin mRNA (UVRh2)—a previously undescribed duplication of this gene among Lepidoptera. To investigate its evolutionary origin, we screened eye cDNAs from 14 butterfly species in the subfamily Heliconiinae and found both copies only among Heliconius. Phylogeny-based tests of selection indicate positive selection of UVRh2 following duplication, and some of the positively selected sites correspond to vertebrate visual pigment spectral tuning residues. Epi-microspectrophotometry reveals two UV-absorbing rhodopsins in the H. erato eye with λmax = 355 nm and 398 nm. Along with the additional UV opsin, Heliconius have also evolved 3-hydroxy-DL-kynurenine (3-OHK)-based yellow wing pigments not found in close relatives. Visual models of how butterflies perceive wing color variation indicate this has resulted in an expansion of the number of distinguishable yellow colors on Heliconius wings. Functional diversification of the UV-sensitive visual pigments may help explain why the yellow wing pigments of Heliconius are so colorful in the UV range compared to the yellow pigments of close relatives lacking the UV opsin duplicate. PMID:20133601

  8. Retinal Development and Ommin Pigment in the Cranchiid Squid Teuthowenia pellucida (Cephalopoda: Oegopsida)

    PubMed Central

    Evans, Aaron B.; Acosta, Monica L.; Bolstad, Kathrin S.

    2015-01-01

    The cranchiid Teuthowenia pellucida, like many deep-sea squid species, possesses large eyes that maximise light sensitivity in a nearly aphotic environment. To assess ontogenetic changes in the visual system, we conducted morphometric and histological analyses of the eyes using specimens from New Zealand collections. While the ratio between eye diameter and mantle length maintained a linear relationship throughout development, histological sections of the retina revealed that the outer photoreceptor layer became proportionally longer as the animal aged, coincident with a habitat shift into deeper, darker ocean strata. Other retinal layers maintained the same absolute thickness as was observed in paralarvae. Granules of the pigment ommin, normally located in the screening layer positioned at the base of the photoreceptors, were also observed at the outer end of the photoreceptor segments throughout the retina in young and mid-sized specimens. Early developmental stages of this species, dwelling in shallow waters, may therefore rely on migratory ommin to help shield photoreceptors from excess light and prevent over-stimulation. The oldest, deeper-dwelling specimens of T. pellucida examined had longer photoreceptors, and little or no migrated ommin was observed; we suggest therefore that short-term adaptive mechanisms for bright light conditions may be used primarily during epipelagic, early life stages in this species. PMID:25970484

  9. Retinal Development and Ommin Pigment in the Cranchiid Squid Teuthowenia pellucida (Cephalopoda: Oegopsida).

    PubMed

    Evans, Aaron B; Acosta, Monica L; Bolstad, Kathrin S

    2015-01-01

    The cranchiid Teuthowenia pellucida, like many deep-sea squid species, possesses large eyes that maximise light sensitivity in a nearly aphotic environment. To assess ontogenetic changes in the visual system, we conducted morphometric and histological analyses of the eyes using specimens from New Zealand collections. While the ratio between eye diameter and mantle length maintained a linear relationship throughout development, histological sections of the retina revealed that the outer photoreceptor layer became proportionally longer as the animal aged, coincident with a habitat shift into deeper, darker ocean strata. Other retinal layers maintained the same absolute thickness as was observed in paralarvae. Granules of the pigment ommin, normally located in the screening layer positioned at the base of the photoreceptors, were also observed at the outer end of the photoreceptor segments throughout the retina in young and mid-sized specimens. Early developmental stages of this species, dwelling in shallow waters, may therefore rely on migratory ommin to help shield photoreceptors from excess light and prevent over-stimulation. The oldest, deeper-dwelling specimens of T. pellucida examined had longer photoreceptors, and little or no migrated ommin was observed; we suggest therefore that short-term adaptive mechanisms for bright light conditions may be used primarily during epipelagic, early life stages in this species. PMID:25970484

  10. Light and dark adaptation mechanisms in the compound eyes of Myrmecia ants that occupy discrete temporal niches.

    PubMed

    Narendra, Ajay; Greiner, Birgit; Ribi, Willi A; Zeil, Jochen

    2016-08-15

    Ants of the Australian genus Myrmecia partition their foraging niche temporally, allowing them to be sympatric with overlapping foraging requirements. We used histological techniques to study the light and dark adaptation mechanisms in the compound eyes of diurnal (Myrmecia croslandi), crepuscular (M. tarsata, M. nigriceps) and nocturnal ants (M. pyriformis). We found that, except in the day-active species, all ants have a variable primary pigment cell pupil that constricts the crystalline cone in bright light to control for light flux. We show for the nocturnal M. pyriformis that the constriction of the crystalline cone by the primary pigment cells is light dependent whereas the opening of the aperture is regulated by an endogenous rhythm. In addition, in the light-adapted eyes of all species, the retinular cell pigment granules radially migrate towards the rhabdom, a process that in both the day-active M. croslandi and the night-active M. pyriformis is driven by ambient light intensity. Visual system properties thus do not restrict crepuscular and night-active ants to their temporal foraging niche, while day-active ants require high light intensities to operate. We discuss the ecological significance of these adaptation mechanisms and their role in temporal niche partitioning. PMID:27535985

  11. Healthy Eyes

    MedlinePlus

    ... please turn Javascript on. Healthy Eyes Maintaining Your Vision Click for more information Taking good care of ... are qualified to perform eye exams. Aging and Vision Changes As you age, it is normal to ...

  12. Eye Cancer

    MedlinePlus

    ... adults are melanoma and lymphoma. The most common eye cancer in children is retinoblastoma, which starts in the cells of the retina. ... from other parts of the body. Treatment for eye cancer varies by the type and by how advanced ...

  13. Eye Anatomy

    MedlinePlus

    ... News About Us Donate In This Section Eye Anatomy en Español email Send this article to a ... You at Risk For Glaucoma? Childhood Glaucoma Eye Anatomy Five Common Glaucoma Tests Glaucoma Facts and Stats ...

  14. Your Eyes

    MedlinePlus

    ... the eye and keeps it healthy. previous continue Light, Lens, Action These next parts are really cool, ... the eye. previous continue Rods and Cones Process Light The retina uses special cells called rods and ...

  15. Electroporation of Embryonic Chick Eyes

    PubMed Central

    Luz-Madrigal, Agustín; Grajales-Esquivel, Erika; Del Rio-Tsonis, Katia

    2016-01-01

    The chick embryo has prevailed as one of the major models to study developmental biology, cell biology and regeneration. From all the anatomical features of the chick embryo, the eye is one of the most studied. In the chick embryo, the eye develops between 26 and 33 h after incubation (Stages 8–9, Hamburger and Hamilton, 1951). It originates from the posterior region of the forebrain, called the diencephalon. However, the vertebrate eye includes tissues from different origins including surface ectoderm (lens and cornea), anterior neural plate (retina, iris, ciliary body and retinal pigmented epithelium) and neural crest/head mesoderm (stroma of the iris and of the ciliary body as well as choroid, sclera and part of the cornea). After gastrulation, a single eye field originates from the anterior neural plate and is characterized by the expression of eye field transcriptional factors (EFTFs) that orchestrate the program for eye development. Later in development, the eye field separates in two and the optic vesicles form. After several inductive interactions with the lens placode, the optic cup forms. At Stages 14–15, the outer layer of the optic cup becomes the retinal pigmented epithelium (RPE) while the inner layer forms the neuroepithelium that eventually differentiates into the retina. One main advantage of the chick embryo, is the possibility to perform experiments to over-express or to down-regulate gene expression in a place and time specific manner to explore gene function and regulation. The aim of this protocol is to describe the electroporation techniques at Stages 8–12 (anterior neural fold and optic vesicle stages) and Stages 19–26 (eye cup, RPE and neuroepithelium). We provide a full description of the equipment, materials and electrode set up as well as a detailed description of the highly reproducible protocol including some representative results. This protocol has been adapted from our previous publications Luz-Madrigal et al. (2014) and Zhu

  16. Eye Problems

    MedlinePlus

    ... Do you have diabetes, and have you noticed any changes in your vision? Yes Over time, too much glucose (sugar) in the ... eye pink, red or irritated, and are there any secretions or mucus from the eye? Yes CONJUNCTIVITIS, also called "PINK EYE," can be caused ...

  17. Eye floaters

    MedlinePlus

    ... eyes are not on the surface of your eyes, but inside them. These floaters are bits of cell debris that drift around ... is the layer in the back of the eye.) If you notice a sudden increase in floaters or if you see floaters along with flashes ...

  18. Mechanisms of protein delivery to melanosomes in pigment cells

    PubMed Central

    Sitaram, Anand; Marks, Michael S.

    2012-01-01

    SUMMARY Vertebrate pigment cells in the eye and skin are useful models for cell types that use specialized endosomal trafficking pathways to partition cargo proteins to unique lysosome-related organelles such as melanosomes. This review describes current models of protein trafficking required for melanosome biogenesis in mammalian melanocytes. PMID:22505665

  19. Circadian rhythms affect electroretinogram, compound eye color, striking behavior and locomotion of the praying mantis Hierodula patellifera.

    PubMed

    Schirmer, Aaron E; Prete, Frederick R; Mantes, Edgar S; Urdiales, Andrew F; Bogue, Wil

    2014-11-01

    Many behaviors and physiological processes oscillate with circadian rhythms that are synchronized to environmental cues (e.g. light onset), but persist with periods of ~24 h in the absence of such cues. We used a multilevel experimental approach to assess whether circadian rhythms modulate several aspects of the visual physiology and behavior of the praying mantis Hierodula patellifera. We used electroretinograms (ERGs) to assess compound eye sensitivity, colorimetric photographic analyses to assess compound eye color changes (screening pigment migration), behavioral assays of responsiveness to computer-generated prey-like visual stimuli and analyses of locomotor activity patterns on a modified treadmill apparatus. Our results indicate that circadian clocks control and/or modulate each of the target behaviors. Strong rhythms, persisting under constant conditions, with periods of ~24 h were evident in photoreceptor sensitivity to light, appetitive responsiveness to prey-like stimuli and gross locomotor activity. In the first two cases, responsiveness was highest during the subjective night and lowest during the subjective day. Locomotor activity was strongly clustered around the transition time from day to night. In addition, pigment migration and locomotor behavior responded strongly to light:dark cycles and anticipated the light-dark transition, suggesting that the circadian clocks modulating both were entrained to environmental light cues. Together, these data indicate that circadian rhythms operate at the cellular, cellular systems and organismal level in H. patellifera. Our results represent an intriguing first step in uncovering the complexities of circadian rhythms in the Mantodea. PMID:25214491

  20. Pigment-protein complexes

    SciTech Connect

    Siegelman, H W

    1980-01-01

    The photosynthetically-active pigment protein complexes of procaryotes and eucaryotes include chlorophyll proteins, carotenochlorophyll proteins, and biliproteins. They are either integral components or attached to photosynthetic membranes. Detergents are frequently required to solubilize the pigment-protein complexes. The membrane localization and detergent solubilization strongly suggest that the pigment-protein complexes are bound to the membranes by hydrophobic interactions. Hydrophobic interactions of proteins are characterized by an increase in entropy. Their bonding energy is directly related to temperature and ionic strength. Hydrophobic-interaction chromatography, a relatively new separation procedure, can furnish an important method for the purification of pigment-protein complexes. Phycobilisome purification and properties provide an example of the need to maintain hydrophobic interactions to preserve structure and function.

  1. Photosynthetic Pigments in Diatoms.

    PubMed

    Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

    2015-09-01

    Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries. PMID:26389924

  2. Photosynthetic Pigments in Diatoms

    PubMed Central

    Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

    2015-01-01

    Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries. PMID:26389924

  3. Comparative morphology of the eyes of Sagitta (Chaetognatha) in relation to depth of habitat.

    PubMed

    Goto, T; Terazaki, M; Yoshida, M

    1989-01-01

    A survey of the eye structure in 10 species of Sagitta (phylum Chaetognatha) which differ in habitat was carried out: 5 epipelagic, 4 mesopelagic and 1 bathypelagic species. Paying attention to the dimension of the pigment cell, and assuming that the perforated lamellae are the photoreceptive regions (PRs), we classified the eyes of the 10 species into 5 types. In type I and II eyes there is one large pigment cell. The maximum length of the pigment cell relative to that of the eye (PC/E) is more than 30% in dorsal view and more than 50% in transverse sections. The pigment cell is surrounded by a wide area of the PR that we designated "central PR". The type II eye possesses, in addition, near the periphery of the eye, masses of PRs which measure about 15% of the central one in size. We call these positionally separated PRs "peripheral PR". In type III eyes the pigment cell and the central PR are small (PC/E is about 10% in dorsal view and less than 40% in transverse sections) and the peripheral PRs are scattered. In type IV eye the pigment cell is also small and the central PRs extend to the periphery. In type V eye the pigment cell is absent and the PR occupies a wide area of the dorsal half of the eye. The type I and II eyes were found mostly in epipelagic species, the type III and IV, in mesopelagic species, and the type V, in bathypelagic species. The adaptational significance of the small pigment cells, the peripheral PRs, and the pigmentless eye is discussed. In addition, we report a new type of photoreceptive cell in mesopelagic Sagitta zetesios, in which two receptoral processes emerge from single cells, in contrast to one in all the other species of Sagitta. PMID:2920816

  4. Skin pigmentation evaluation in broilers fed natural and synthetic pigments.

    PubMed

    Castañeda, M P; Hirschler, E M; Sams, A R

    2005-01-01

    Broiler carcass skin color is important in the United States and Mexico. This study evaluated the use of natural and synthetic pigments in broiler diets at commercial levels. Birds were fed natural or synthetic pigments at low or high levels, simulating US and Mexican commercial practices. Skin color was measured during live production (3 to 7 wk of age) and after slaughter and chilling. The natural pigments had consistently greater skin b* values (yellowness) than the synthetic pigments. The high levels produced greater skin b* values than the low levels, regardless of source. The synthetic pigments had a slower increase in skin b* but reached the same level as the natural low by 7 wk. There was no difference in skin a* values (redness) due to pigment source or level or the age of the bird. By 7 wk, all pigment sources approached plateau levels in the blood, but the synthetic pigment diet produced higher blood levels of yellow and red pigments than the natural pigment diets. Processing intensified skin yellowness and reduced skin redness. These data suggest that although synthetic pigments might have been absorbed better than natural ones, natural pigments were more efficient at increasing skin yellowness and there were only small differences between high and low levels for each pigment source. This finding may allow reduction in pigment use and feed cost to achieve the same skin acceptance by the consumer. PMID:15685954

  5. Corrosion-Indicating Pigment And Probes

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Bugga, Ratnakumar V.; Attia, Alan I.

    1993-01-01

    Proposed hydrogen-sensitive paint for metal structures changes color at onset of corrosion, involving emission of hydrogen as result of electrochemical reactions. Pigment of suitable paint includes rhodium compound RhCl(PPh3)3, known as Wilkinson's catalyst. As coating on critical parts of such structures as bridges and aircraft, paint gives early warning of corrosion, and parts thus repaired or replaced before failing catastrophically. Reveals corrosion before it becomes visible to eye. Inspection for changes in color not ordinarily necessitate removal of structure from service, and costs less than inspection by x-ray or thermal neutron radiography, ultrasonic, eddy-current, or acoustic-emission techniques.

  6. Monte Carlo modeling of pigmented lesions

    NASA Astrophysics Data System (ADS)

    Gareau, Daniel; Jacques, Steven; Krueger, James

    2014-03-01

    Colors observed in clinical dermoscopy are critical to diagnosis but the mechanisms that lead to the spectral components of diffuse reflectance are more than meets the eye: combinations of the absorption and scattering spectra of the biomolecules as well as the "structural color" effect of skin anatomy. We modeled diffuse remittance from skin based on histopathology. The optical properties of the tissue types were based on the relevant chromophores and scatterers. The resulting spectral images mimic the appearance of pigmented lesions quite well when the morphology is mathematically derived but limited when based on histopathology, raising interesting questions about the interaction between various wavelengths with various pathological anatomical features.

  7. Eye development.

    PubMed

    Baker, Nicholas E; Li, Ke; Quiquand, Manon; Ruggiero, Robert; Wang, Lan-Hsin

    2014-06-15

    The eye has been one of the most intensively studied organs in Drosophila. The wealth of knowledge about its development, as well as the reagents that have been developed, and the fact that the eye is dispensable for survival, also make the eye suitable for genetic interaction studies and genetic screens. This article provides a brief overview of the methods developed to image and probe eye development at multiple developmental stages, including live imaging, immunostaining of fixed tissues, in situ hybridizations, and scanning electron microscopy and color photography of adult eyes. Also summarized are genetic approaches that can be performed in the eye, including mosaic analysis and conditional mutation, gene misexpression and knockdown, and forward genetic and modifier screens. PMID:24784530

  8. EYE DEVELOPMENT

    PubMed Central

    Baker, Nicholas E.; Li, Ke; Quiquand, Manon; Ruggiero, Robert; Wang, Lan-Hsin

    2014-01-01

    The eye has been one of the most intensively studied organs in Drosophila. The wealth of knowledge about its development, as well as the reagents that have been developed, and the fact that the eye is dispensable for survival, also make the eye suitable for genetic interaction studies and genetic screens. This chapter provides a brief overview of the methods developed to image and probe eye development at multiple developmental stages, including live imaging, immunostaining of fixed tissues, in situ hybridizations, and scanning electron microscopy and color photography of adult eyes. Also summarized are genetic approaches that can be performed in the eye, including mosaic analysis and conditional mutation, gene misexpression and knockdown, and forward genetic and modifier screens. PMID:24784530

  9. Ultraviolet vision in birds: the importance of transparent eye media

    PubMed Central

    Lind, Olle; Mitkus, Mindaugas; Olsson, Peter; Kelber, Almut

    2014-01-01

    Ultraviolet (UV)-sensitive visual pigments are widespread in the animal kingdom but many animals, for example primates, block UV light from reaching their retina by pigmented lenses. Birds have UV-sensitive (UVS) visual pigments with sensitivity maxima around 360–373 nm (UVS) or 402–426 nm (violet-sensitive, VS). We describe how these pigments are matched by the ocular media transmittance in 38 bird species. Birds with UVS pigments have ocular media that transmit more UV light (wavelength of 50% transmittance, λT0.5, 323 nm) than birds with VS pigments (λT0.5, 358 nm). Yet, visual models predict that colour discrimination in bright light is mostly dependent on the visual pigment (UVS or VS) and little on the ocular media. We hypothesize that the precise spectral tuning of the ocular media is mostly relevant for detecting weak UV signals, e.g. in dim hollow-nests of passerines and parrots. The correlation between eye size and UV transparency of the ocular media suggests little or no lens pigmentation. Therefore, only small birds gain the full advantage from shifting pigment sensitivity from VS to UVS. On the other hand, some birds with VS pigments have unexpectedly low UV transmission of the ocular media, probably because of UV blocking lens pigmentation. PMID:24258716

  10. Histopathologic Findings in the Areas of Orange Pigment Overlying Choroidal Melanomas

    PubMed Central

    Garcia, Maria D.; Salomao, Diva R.; Marmorstein, Alan D.; Pulido, Jose S.

    2016-01-01

    Purpose Orange pigment is an important sign of malignancy in melanocytic tumors. There is a question as to whether the pigment accumulation is inside of macrophages or retinal pigment epithelial (RPE) cells. We investigated which cells are involved with this color alteration. Methods We examined enucleated specimens from two patients with choroidal melanoma and dense orange pigment on fundus examination. Color fundus and fundus autofluorescence (FAF) photographs were reviewed followed by examination with fluorescent microscopy, electron microscopy, and immunohistochemistry of enucleated eyes for the specific areas corresponding to the orange pigment. Results Orange pigment was observed on color fundus photography and correlated with areas of hyperautofluorescence on FAF. Fluorescent microscopy of sections of the enucleated eyes showed autofluorescence in the RPE, which were most pronounced where there was a localized retinal detachment and reactive hyperplasia of the RPE. Immunohistochemical studies were done with keratin (OSCAR and AE1/AE3) and S-100 stained RPE cells, which still were attached to Bruch's membrane. Histiocytes present in the detached retina stained with anti-CD163 antibody and did not show autofluorescence. Electron microscopy studies of the same areas showed the presence of lipofuscin and melanolipofuscin within the clustered RPE cells. Conclusions Orange pigment in choroidal melanocytic lesions originates from the RPE cells, rather than macrophages, and is most abundant where there is proliferation of the RPE. Translational Relevance The orange pigment tumoral biomarker arises and is in the retinal pigment epithelium. PMID:27190699

  11. Eye Injuries at Home

    MedlinePlus

    ... Patient Stories Español Eye Health / Tips & Prevention Eye Injuries Sections Preventing Eye Injuries Recognizing and Treating Eye ... Sports Eye Injuries by the Numbers — Infographic Eye Injuries at Home Reviewed by: Brenda Pagan-Duran MD ...

  12. Adenocarcinoma of the pigmented ciliary epithelium

    PubMed Central

    Sukeda, Aoi; Mori, Taisuke; Suzuki, Shigenobu; Ochiai, Atsushi

    2014-01-01

    Adenocarcinoma of the pigmented ciliary epithelium is an exceptionally rare eye tumour, with only a few cases reported to date. We encountered such a case in a 50-year-old woman who reported seeing floaters in her right eye. Fundus examination and MRI revealed an elevated lesion located in the ciliary body compressing the lens. The ciliary body was resected under the diagnosis of ciliary adenoma. On histological examination, the tumour exhibited epithelial features with glandular formation and moderate nuclear pleomorphism. The tumour invaded the subepithelial stroma of the ciliary body. Immunohistochemical findings were positive for cytokeratin OSCAR, AE1/AE3, CK7, EMA, S100, Melan A, HMB45, and microphthalmia-associated transcription factor. PMID:25015166

  13. MULTISPECTRAL DIAGNOSTIC IMAGING OF THE IRIS IN PIGMENT DISPERSION SYNDROME

    PubMed Central

    Roberts, Daniel K.; Lukic, Ana; Yang, Yongyi; Wilensky, Jacob T.; Wernick, Miles N.

    2011-01-01

    Purpose To determine if wavelength selection with near infrared (NIR) iris imaging may enhance iris transillumination defects (ITDs) in pigment dispersion syndrome. Methods An experimental apparatus was used to acquire iris images in 6 African-American (AA) and 6 White patients with pigment dispersion syndrome. Light emitting diode (LED) probes of 6 different spectral bands (700 to 950 nm) were used to project light into patients' eyes. Iris patterns were photographed, ITD regions of interest were outlined, and region of interest contrasts were calculated for each spectral band. Results Contrasts varied as a function of wavelength (P<0.0001) for both groups, but tended to be highest in the 700 to 800 nm range. Contrasts were higher in Whites than AAs at 700 nm but the opposite was found at 810 nm (P<0.001). Conclusions Optimized NIR iris imaging may be wavelength dependent. Ideal wavelength to image ITDs in more pigmented eyes may be slightly longer than for less pigmented eyes. PMID:21423031

  14. Stripes and belly-spots -- a review of pigment cell morphogenesis in vertebrates.

    PubMed

    Kelsh, Robert N; Harris, Melissa L; Colanesi, Sarah; Erickson, Carol A

    2009-02-01

    Pigment patterns in the integument have long-attracted attention from both scientists and non-scientists alike since their natural attractiveness combines with their excellence as models for the general problem of pattern formation. Pigment cells are formed from the neural crest and must migrate to reach their final locations. In this review, we focus on our current understanding of mechanisms underlying the control of pigment cell migration and patterning in diverse vertebrates. The model systems discussed here - chick, mouse, and zebrafish - each provide unique insights into the major morphogenetic events driving pigment pattern formation. In birds and mammals, melanoblasts must be specified before they can migrate on the dorsolateral pathway. Transmembrane receptors involved in guiding them onto this route include EphB2 and Ednrb2 in chick, and Kit in mouse. Terminal migration depends, in part, upon extracellular matrix reorganization by ADAMTS20. Invasion of the ectoderm, especially into the feather germ and hair follicles, requires specific signals that are beginning to be characterized. We summarize our current understanding of the mechanisms regulating melanoblast number and organization in the epidermis. We note the apparent differences in pigment pattern formation in poikilothermic vertebrates when compared with birds and mammals. With more pigment cell types, migration pathways are more complex and largely unexplored; nevertheless, a role for Kit signaling in melanophore migration is clear and indicates that at least some patterning mechanisms may be highly conserved. We summarize the multiple factors thought to contribute to zebrafish embryonic pigment pattern formation, highlighting a recent study identifying Sdf1a as one factor crucial for regulation of melanophore positioning. Finally, we discuss the mechanisms generating a second, metamorphic pigment pattern in adult fish, emphasizing recent studies strengthening the evidence that undifferentiated

  15. Effect of cadmium chloride on the distal retinal pigment cells of the fiddler crab, Uca pugilator

    SciTech Connect

    Reddy, P.S.; Fingerman, M.; Nguyen, L.K.; Obih, P.

    1997-03-01

    Crustaceans have two sets of pigmentary effectors, chromatophores and retinal pigment cells. Retinal pigments control the amount of light striking the rhabdom, the photosensitive portion of each ommatidium, screening the rhabdom in bright light and uncovering it in darkness or dim light. Migration of the distal pigment in the fiddler crab, Uca pugilalor, is regulated by a light-adapting hormone and a dark-adapting hormone. The black chromatophores of this crab are also controlled by a pair of hormones. Both pigmentary effectors exhibit circadian rhythms. The effects of some organic and inorganic pollutants on the ability of Uca pugilator to change color have been described. Exposure of this crab to naphthalene or cadmium results in decreased ability to disperse the pigment in their black chromatophores, the exposed crabs becoming paler than the unexposed crabs. Norepinephrine triggers release of both the black pigment-dispersing hormone and the light-adapting hormone. In view of the facts that (a) these hormones which regulate the black chromatophores and distal pigment are synthesized in and released from the eyestalk neuroendocrine complex, (b) the black pigment-dispersing hormone and the light-adapting hormone may actually be the same hormone. having two different activities and (c) release of both the black pigment-dispersing hormone and the light-adapting hormone is triggered by norepinephrine, the present investigation was carried out to determine the effect of cadmium on distal pigment migration in Uca pugilator. More specifically, for comparison with the previously reported effect of cadmium on pigment migration in the black chromatophores, we wished to determine whether the distal pigment of fiddler crabs exposed to cadmium chloride is capable of as wide a range of movement as in unexposed crabs, and if not what might be the explanation. This is the first report of the effect of a pollutant on a retinal pigment of any crustacean. 12 refs., 3 tabs.

  16. Biology of pigmentation

    SciTech Connect

    Parker, F.

    1981-01-01

    The many factors involved in the normal pigmentation of human skin are highly complex involving anatomic, biochemical, and genetic aspects of melanocytes in the skin and the influence of UV light and various hormones on the melanocytes. It is probably more than just coincidence that the melanocytes, which are of neurogenic origin, are so responsive to several trophic hormones produced in the brain. Understanding of the various factors involved in the normal pigmentary process is crucial to explaining the many alterations and anomalies in human pigmentation.

  17. Dry Eye

    MedlinePlus

    ... surgery, called punctal cautery, is recommended to permanently close the drainage holes. The procedure helps keep the limited volume of tears on the eye for a longer period of time. In some patients with dry eye, supplements or dietary sources (such as tuna fish) of omega-3 fatty ...

  18. Eye Complications

    MedlinePlus

    ... the cornea, which focuses light while protecting the eye. After light passes through the cornea, it travels through a ... and have them progress faster. With cataracts, the eye's clear lens clouds, blocking light. To help deal with mild cataracts, you may ...

  19. Mutations in CTNNA1 cause butterfly-shaped pigment dystrophy and perturbed retinal pigment epithelium integrity.

    PubMed

    Saksens, Nicole T M; Krebs, Mark P; Schoenmaker-Koller, Frederieke E; Hicks, Wanda; Yu, Minzhong; Shi, Lanying; Rowe, Lucy; Collin, Gayle B; Charette, Jeremy R; Letteboer, Stef J; Neveling, Kornelia; van Moorsel, Tamara W; Abu-Ltaif, Sleiman; De Baere, Elfride; Walraedt, Sophie; Banfi, Sandro; Simonelli, Francesca; Cremers, Frans P M; Boon, Camiel J F; Roepman, Ronald; Leroy, Bart P; Peachey, Neal S; Hoyng, Carel B; Nishina, Patsy M; den Hollander, Anneke I

    2016-02-01

    Butterfly-shaped pigment dystrophy is an eye disease characterized by lesions in the macula that can resemble the wings of a butterfly. Here we report the identification of heterozygous missense mutations in the CTNNA1 gene (encoding α-catenin 1) in three families with butterfly-shaped pigment dystrophy. In addition, we identified a Ctnna1 missense mutation in a chemically induced mouse mutant, tvrm5. Parallel clinical phenotypes were observed in the retinal pigment epithelium (RPE) of individuals with butterfly-shaped pigment dystrophy and in tvrm5 mice, including pigmentary abnormalities, focal thickening and elevated lesions, and decreased light-activated responses. Morphological studies in tvrm5 mice demonstrated increased cell shedding and the presence of large multinucleated RPE cells, suggesting defects in intercellular adhesion and cytokinesis. This study identifies CTNNA1 gene variants as a cause of macular dystrophy, indicates that CTNNA1 is involved in maintaining RPE integrity and suggests that other components that participate in intercellular adhesion may be implicated in macular disease. PMID:26691986

  20. Mutations in CTNNA1 cause butterfly-shaped pigment dystrophy and perturbed retinal pigment epithelium integrity

    PubMed Central

    Saksens, Nicole T.M.; Krebs, Mark P.; Schoenmaker-Koller, Frederieke E.; Hicks, Wanda; Yu, Minzhong; Shi, Lanying; Rowe, Lucy; Collin, Gayle B.; Charette, Jeremy R.; Letteboer, Stef J.; Neveling, Kornelia; van Moorsel, Tamara W.; Abu-Ltaif, Sleiman; De Baere, Elfride; Walraedt, Sophie; Banfi, Sandro; Simonelli, Francesca; Cremers, Frans P.M.; Boon, Camiel J.F.; Roepman, Ronald; Leroy, Bart P.; Peachey, Neal S.; Hoyng, Carel B.; Nishina, Patsy M.; den Hollander, Anneke I.

    2015-01-01

    Butterfly-shaped pigment dystrophy is an eye disease characterized by lesions in the macula that can resemble the wings of a butterfly. Here, we report the identification of heterozygous missense mutations in the α-catenin 1 (CTNNA1) gene in three families with butterfly-shaped pigment dystrophy. In addition, we identified a Ctnna1 missense mutation in a chemically induced mouse mutant, tvrm5. Parallel clinical phenotypes were observed in the retinal pigment epithelium (RPE) of individuals with butterfly-shaped pigment dystrophy and in tvrm5 mice, including pigmentary abnormalities, focal thickening and elevated lesions, and decreased light-activated responses. Morphological studies in tvrm5 mice revealed increased cell shedding and large multinucleated RPE cells, suggesting defects in intercellular adhesion and cytokinesis. This study identifies CTNNA1 gene variants as a cause of macular dystrophy, suggests that CTNNA1 is involved in maintaining RPE integrity, and suggests that other components that participate in intercellular adhesion may be implicated in macular disease. PMID:26691986

  1. New pigment pattern of the polychromatic Mesanthura protei, Kensley 1980 (Isopoda, Cymothoida, Anthuroidea) from Pulau Tinggi, Johor, Malaysia

    NASA Astrophysics Data System (ADS)

    Chew, Melvin; Rahim, Azman Bin Abdul; Yusof, Nurul Yuziana Binti Mohd

    2015-09-01

    A female Mesanthura protei, Kensley 1980 with a new polychromatic pigment pattern found from dead coral rubbles in the shallow water coral reef area of Pulau Tinggi, Johor, Malaysia is described. The present species is the fifth colour morph of M. protei. In addition, it is distinctive in having irregular spotted pigment pattern (1) between the eyes and (2) pereonites and pleonites dorsally.

  2. Carotenoid binding to proteins: Modeling pigment transport to lipid membranes.

    PubMed

    Reszczynska, Emilia; Welc, Renata; Grudzinski, Wojciech; Trebacz, Kazimierz; Gruszecki, Wieslaw I

    2015-10-15

    Carotenoid pigments play numerous important physiological functions in human organism. Very special is a role of lutein and zeaxanthin in the retina of an eye and in particular in its central part, the macula lutea. In the retina, carotenoids can be directly present in the lipid phase of the membranes or remain bound to the protein-pigment complexes. In this work we address a problem of binding of carotenoids to proteins and possible role of such structures in pigment transport to lipid membranes. Interaction of three carotenoids, beta-carotene, lutein and zeaxanthin with two proteins: bovine serum albumin and glutathione S-transferase (GST) was investigated with application of molecular spectroscopy techniques: UV-Vis absorption, circular dichroism and Fourier transform infrared spectroscopy (FTIR). Interaction of pigment-protein complexes with model lipid bilayers formed with egg yolk phosphatidylcholine was investigated with application of FTIR, Raman imaging of liposomes and electrophysiological technique, in the planar lipid bilayer models. The results show that in all the cases of protein and pigment studied, carotenoids bind to protein and that the complexes formed can interact with membranes. This means that protein-carotenoid complexes are capable of playing physiological role in pigment transport to biomembranes. PMID:26361975

  3. Altered melanocyte differentiation and retinal pigmented epithelium transdifferentiation induced by Mash1 expression in pigment cell precursors.

    PubMed

    Lanning, Jessica L; Wallace, Jaclyn S; Zhang, Deming; Diwakar, Ganesh; Jiao, Zhongxian; Hornyak, Thomas J

    2005-10-01

    Transcription factor genes governing pigment cell development that are associated with spotting mutations in mice include members of several structural transcription factor classes but not members of the basic helix-loop-helix (bHLH) class, important for neurogenesis and myogenesis. To determine the effects of bHLH factor expression on pigment cell development, the neurogenic bHLH factor Mash1 was expressed early in pigment cell development in transgenic mice from the dopachrome tautomerase (Dct) promoter. Dct:Mash1 transgenic founders exhibit variable microphthalmia and patchy coat color hypopigmentation. Transgenic F1 mice exhibit microphthalmia with complete coat color dilution. Marker analysis demonstrates that Mash1 expression in the retinal pigmented epithelium (RPE) initiates neurogenesis in this cell layer, whereas expression in remaining neural crest-derived melanocytes alters their differentiation, in part by profoundly downregulating expression of the p (pink-eyed dilution) gene, while maintaining their cell fate. The effects of transcriptional perturbation of pigment cell precursors by Mash1 further highlight differences between pigment cells of distinct developmental origins, and suggest a mechanism for the alteration of melanogenesis to result in marked coat color dilution. PMID:16185282

  4. Calibration of an eye oximeter with a dynamic eye phantom

    NASA Astrophysics Data System (ADS)

    Nabili, A.; Bardakci, D.; Helling, K.; Matyas, C.; Muro, S.; Ramella-Roman, J. C.

    2008-02-01

    Measurements of oxygen saturation and flow in the retina can yield information about the eye health and the onset of eye pathologies such as Diabetic Retinopathy. Recently we have realized an instrument capable of measuring oxygenation in the retina using six different wavelengths and capable of measuring blood flow using speckle-based techniques. The calibration of such instrument is particularly difficult due to the layered structure of the eye and the lack of alternative measurement techniques. For this purpose we have realized an in vitro model of the human eye. The artificial eye is composed of four layers: the retina vessels, the choroids, the retinal pigmented epithelium (RPE), and the sclera. The retina vessels are modeled with 150 μm tube connected to a micro-pump delivering 34 μl/min. The micro-tube, the pump, and a blood reservoir were connected in a closed circulatory system; blood oxygenation in the vessel could be modified using an external oxygen reservoir. The optical properties of all other layers were mimicked using titanium dioxide as a scatterer and ink as an absorber. The absorption coefficient μa and the scattering coefficient µs of these layers were independently measured using an integrating sphere. Absorption and scattering coefficient of all layers were modified before experimental measurements and a Monte Carlo program was finally used to model the experimental results.

  5. Healthy Eyes

    MedlinePlus

    ... Programs Training and Jobs Home > Healthy Eyes Healthy Vision Diabetes Diabetes Home How Much Do You Know? ... seeing your best. Read more. What are common vision problems? Some of the most common vision problems ...

  6. Eye Allergies

    MedlinePlus

    ... MD Mar. 01, 2015 Eye allergies, called allergic conjunctivitis , are a common condition that occurs when the ... with tearing and burning. Unlike bacterial or viral conjunctivitis, allergic conjunctivitis is not spread from person to ...

  7. Eye emergencies

    MedlinePlus

    ... and there is a good chance of recovery. Alkaline substances -- such as lime, lye, drain cleaners, and ... at high speed by machining, grinding, or hammering metal have the highest risk of injuring the eye. ...

  8. Eye Infections

    MedlinePlus

    ... Health Issues Conditions Abdominal ADHD Allergies & Asthma Autism Cancer Chest & Lungs Chronic Conditions Cleft & Craniofacial Developmental Disabilities Ear Nose & Throat Emotional Problems Eyes Fever From Insects or Animals Genitals and Urinary Tract Glands & Growth ...

  9. Black Eye

    MedlinePlus

    ... Aug 30, 2016 Toddlers Most at Risk of Chemical Burns to Eyes Aug 26, 2016 Firework Blinds Teenager, Severs Hand Jun 29, ... at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For ...

  10. Progression of Retinal Pigment Epithelial Atrophy in Antiangiogenic Therapy of Neovascular Age-Related Macular Degeneration

    PubMed Central

    Schütze, Christopher; Wedl, Manuela; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K.; Schmidt-Erfurth, Ursula

    2015-01-01

    Purpose To monitor retinal pigment epithelial (RPE) atrophy progression during antiangiogenic therapy of neovascular age-related macular degeneration (AMD) over 2 years using polarization-sensitive optical coherence tomography (OCT). Design Prospective interventional case series. Methods setting: Clinical practice. study population: Thirty patients (31 eyes) with treatment-naïve neovascular AMD. observation procedures: Standard intravitreal therapy (0.5 mg ranibizumab) was administered monthly during the first year and pro re nata (PRN; as-needed) during the second year. Spectral-domain (SD) OCT and polarization-sensitive OCT (selectively imaging the RPE) examinations were performed at baseline and at 1, 3, 6, 12, and 24 months using a standardized protocol. RPE-related changes were evaluated using a semi-automated polarization-sensitive OCT segmentation algorithm and correlated with SD OCT and fundus autofluorescence (FAF) findings. main outcome measures: RPE response, geographic atrophy (GA) progression. Results Atrophic RPE changes included RPE thinning, RPE porosity, focal RPE atrophy, and development of GA. Early RPE loss (ie, RPE porosity, focal atrophy) increased progressively during initial monthly treatment and remained stable during subsequent PRN-based therapy. GA developed in 61% of eyes at month 24. Mean GA area increased from 0.77 mm2 at 12 months to 1.10 mm2 (standard deviation = 1.09 mm2) at 24 months. Reactive accumulation of RPE-related material at the lesion borders increased until month 3 and subsequently decreased. Conclusions Progressive RPE atrophy and GA developed in the majority of eyes. RPE migration signifies certain RPE plasticity. Polarization-sensitive OCT specifically images RPE-related changes in neovascular AMD, contrary to conventional imaging methods. Polarization-sensitive OCT allows for precisely monitoring the sequence of RPE-related morphologic changes. PMID:25769245

  11. Aging and Your Eyes

    MedlinePlus

    ... Your Eyes Heath and Aging Aging and Your Eyes Steps to Protect Your Eyesight Common Eye Problems ... weight can also help protect your vision. Common Eye Problems The following common eye problems can be ...

  12. Zinc Deficiency Leads to Lipofuscin Accumulation in the Retinal Pigment Epithelium of Pigmented Rats

    PubMed Central

    Kokkinou, Despina; Eibl, Oliver; Schraermeyer, Ulrich

    2011-01-01

    Background Age-related macular degeneration (AMD) is associated with lipofuscin accumulation whereas the content of melanosomes decreases. Melanosomes are the main storage of zinc in the pigmented tissues. Since the elderly population, as the most affected group for AMD, is prone to zinc deficit, we investigated the chemical and ultrastructural effects of zinc deficiency in pigmented rat eyes after a six-month zinc penury diet. Methodology/Principal Findings Adult Long Evans (LE) rats were investigated. The control animals were fed with a normal alimentation whereas the zinc-deficiency rats (ZD-LE) were fed with a zinc deficient diet for six months. Quantitative Energy Dispersive X-ray (EDX) microanalysis yielded the zinc mole fractions of melanosomes in the retinal pigment epithelium (RPE). The lateral resolution of the analysis was 100 nm. The zinc mole fractions of melanosomes were significantly smaller in the RPE of ZD-LE rats as compared to the LE control rats. Light, fluorescence and electron microscopy, as well as immunohistochemistry were performed. The numbers of lipofuscin granules in the RPE and of infiltrated cells (Ø>3 µm) found in the choroid were quantified. The number of lipofuscin granules significantly increased in ZD-LE as compared to control rats. Infiltrated cells bigger than 3 µm were only detected in the choroid of ZD-LE animals. Moreover, the thickness of the Bruch's membrane of ZD-LE rats varied between 0.4–3 µm and thin, rangy ED1 positive macrophages were found attached at these sites of Bruch's membrane or even inside it. Conclusions/Significance In pigmented rats, zinc deficiency yielded an accumulation of lipofuscin in the RPE and of large pigmented macrophages in the choroids as well as the appearance of thin, rangy macrophages at Bruch's membrane. Moreover, we showed that a zinc diet reduced the zinc mole fraction of melanosomes in the RPE and modulated the thickness of the Bruch's membrane. PMID:22216222

  13. The Genetic Inheritance of the Blue-eyed White Phenotype in Alpacas (Vicugna pacos)

    PubMed Central

    Johnson, Warren E.; Appleton, Belinda R.

    2014-01-01

    White-spotting patterns in mammals can be caused by mutations in the gene KIT, whose protein is necessary for the normal migration and survival of melanocytes from the neural crest. The alpaca (Vicugna pacos) blue-eyed white (BEW) phenotype is characterized by 2 blue eyes and a solid white coat over the whole body. Breeders hypothesize that the BEW phenotype in alpacas is caused by the combination of the gene causing gray fleece and a white-spotting gene. We performed an association study using KIT flanking and intragenic markers with 40 unrelated alpacas, of which 17 were BEW. Two microsatellite alleles at KIT-related markers were significantly associated (P < 0.0001) with the BEW phenotype (bew1 and bew2). In a larger cohort of 171 related individuals, we identify an abundance of an allele (bew1) in gray animals and the occurrence of bew2 homozygotes that are solid white with pigmented eyes. Association tests accounting for population structure and familial relatedness are consistent with a proposed model where these alleles are in linkage disequilibrium with a mutation or mutations that contribute to the BEW phenotype and to individual differences in fleece color. PMID:23144493

  14. Chemical purity and toxicology of pigments used in tattoo inks.

    PubMed

    Petersen, Henrik; Lewe, Dirk

    2015-01-01

    The safety of tattoo inks has obviously increased in Europe since the existence of European Union Resolution ResAP(2008)1, which resulted in the improved quality control of pigment raw materials due to the definition of impurity limits that manufacturers can refer to. High-performance pigments are mostly used in tattoo inks, and these pigments are supposed to be chemically inert and offer high light fastness and low migration in solvents. However, these pigments were not developed or produced for applications involving long-term stay in the dermis or contact with bodily fluids. Therefore, these pigments often do not comply with the purity limits of the resolution; however, it is required that every distributed tattoo ink does not contain aromatic amines and not exceed the limits of heavy metals or polycyclic aromatic hydrocarbons. Current toxicity studies of pigments underline that no ecotoxicological threat to human health or to the environment should be expected. However, the pigment as well as its impurities and coating materials must be considered. In order to evaluate the safety of pigments according to their impurities, two different validated sample preparation methods are necessary: (1) simulation of their long-term stay in the bodily fluid of the dermis and (2) simulation of cleavage due to laser removal or ultraviolet exposure. The development of standardized, validated and well-adapted methods for this application has to be part of prospective efforts. Concerning legislation, it might be appropriate that the first regulative approaches be based on those of cosmetics. PMID:25833635

  15. Pupil Size in Spider Eyes Is Linked to Post-Ecdysal Lens Growth

    PubMed Central

    Fenk, Lisa M.; Heidlmayr, Karin; Lindner, Philipp; Schmid, Axel

    2010-01-01

    In this study we describe a distinctive pigment ring that appears in spider eyes after ecdysis and successively decreases in size in the days thereafter. Although pigment stops in spider eyes are well known, size variability is, to our knowledge, reported here for the first time. Representative species from three families (Ctenidae, Sparassidae and Lycosidae) are investigated and, for one of these species (Cupiennius salei, Ctenidae), the progressive increase in pupil diameter is monitored. In this species the pupil occupies only a fourth of the total projected lens surface after ecdysis and reaches its final size after approximately ten days. MicroCT images suggest that the decrease of the pigment ring is linked to the growth of the corneal lens after ecdysis. The pigment rings might improve vision in the immature eye by shielding light rays that would otherwise enter the eye via peripheral regions of the cornea, beside the growing crystalline lens. PMID:21209876

  16. Eye tracker.

    PubMed

    Pruehsner, W; Enderle, J D

    1999-01-01

    A device that records saccadic eye movements, the Eye Tracker, is presented in this paper. The Eye Tracker utilizes infra-red technology mounted on fully adjustable goggles to follow eye movements targeted by either a goggles mounted HUD type display or a wall mounted light bank. Output from the goggles is remotely sent to a PC type computer, which leads to device portability. The goggles can also maintain output data in an internal memory for latter download. The user interface is Windows based with the output from the goggles represented as a trace map or plotted points. This output can also be saved or printed for future reference. The user interface can be used on any PC type computer. The device is designed with reference to standard ISO design methodology. Safety in design and final product usage has also been addressed with reference to standard ISO type procedures. Device accuracy is maintained by precise construction of the IR units in the goggles and tight control of cross talk between each IR device plus filtering of ambient light signals. Also, a reset feature is included to maintain equal baseline control. An automatic switching device is included in the goggles to allow the Eye Tracker to "warm up," assuring that equal IR power is delivered for each subject tested. The IR units in the goggles are also modular in case replacement is required. PMID:11143354

  17. Raman Spectroscopy of Microbial Pigments

    PubMed Central

    Edwards, Howell G. M.; Oren, Aharon

    2014-01-01

    Raman spectroscopy is a rapid nondestructive technique providing spectroscopic and structural information on both organic and inorganic molecular compounds. Extensive applications for the method in the characterization of pigments have been found. Due to the high sensitivity of Raman spectroscopy for the detection of chlorophylls, carotenoids, scytonemin, and a range of other pigments found in the microbial world, it is an excellent technique to monitor the presence of such pigments, both in pure cultures and in environmental samples. Miniaturized portable handheld instruments are available; these instruments can be used to detect pigments in microbiological samples of different types and origins under field conditions. PMID:24682303

  18. P gene as an inherited biomarker of human eye color.

    PubMed

    Rebbeck, Timothy R; Kanetsky, Peter A; Walker, Amy H; Holmes, Robin; Halpern, Allan C; Schuchter, Lynn M; Elder, David E; Guerry, DuPont

    2002-08-01

    Human pigmentation, including eye color, has been associated with skin cancer risk. The P gene is the human homologue to the mouse pink-eye dilution locus and is responsible for oculocutaneous albinism type 2 and other phenotypes that confer eye hypopigmentation. The P gene is located on chromosome 15q11.2-q12, which is also the location of a putative eye pigmentation gene (EYCL3) inferred to exist by linkage analysis. Therefore, the P gene is a strong candidate for determination of human eye color. Using a sample of 629 normally pigmented individuals, we found that individuals were less likely to have blue or gray eyes if they had P gene variants Arg305Trp (P = 0.002), Arg419Gln (P = 0.001), or the combination of both variants (P = 0.003). These results suggest that P gene, in part, determines normal phenotypic variation in human eye color and may therefore represent an inherited biomarker of cutaneous cancer risk. PMID:12163334

  19. Eye and orbit ultrasound

    MedlinePlus

    Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... ophthalmology department of a hospital or clinic. Your eye is numbed with medicine (anesthetic drops). The ultrasound ...

  20. A global view of the OCA2-HERC2 region and pigmentation.

    PubMed

    Donnelly, Michael P; Paschou, Peristera; Grigorenko, Elena; Gurwitz, David; Barta, Csaba; Lu, Ru-Band; Zhukova, Olga V; Kim, Jong-Jin; Siniscalco, Marcello; New, Maria; Li, Hui; Kajuna, Sylvester L B; Manolopoulos, Vangelis G; Speed, William C; Pakstis, Andrew J; Kidd, Judith R; Kidd, Kenneth K

    2012-05-01

    Mutations in the gene OCA2 are responsible for oculocutaneous albinism type 2, but polymorphisms in and around OCA2 have also been associated with normal pigment variation. In Europeans, three haplotypes in the region have been shown to be associated with eye pigmentation and a missense SNP (rs1800407) has been associated with green/hazel eyes (Branicki et al. in Ann Hum Genet 73:160-170, 2009). In addition, a missense mutation (rs1800414) is a candidate for light skin pigmentation in East Asia (Yuasa et al. in Biochem Genet 45:535-542, 2007; Anno et al. in Int J Biol Sci 4, 2008). We have genotyped 3,432 individuals from 72 populations for 21 SNPs in the OCA2-HERC2 region including those previously associated with eye or skin pigmentation. We report that the blue-eye associated alleles at all three haplotypes were found at high frequencies in Europe; however, one is restricted to Europe and surrounding regions, while the other two are found at moderate to high frequencies throughout the world. We also observed that the derived allele of rs1800414 is essentially limited to East Asia where it is found at high frequencies. Long-range haplotype tests provide evidence of selection for the blue-eye allele at the three haplotyped systems but not for the green/hazel eye SNP allele. We also saw evidence of selection at the derived allele of rs1800414 in East Asia. Our data suggest that the haplotype restricted to Europe is the strongest marker for blue eyes globally and add further inferential evidence that the derived allele of rs1800414 is an East Asian skin pigmentation allele. PMID:22065085

  1. Reflections on colourful ommatidia of butterfly eyes.

    PubMed

    Stavenga, Doekele G

    2002-04-01

    The eye shine of butterflies from a large number of ommatidia was observed with a modified epi-illumination apparatus equipped with an objective lens of large numerical aperture. A few representative cases are presented: the satyrine Bicyclus anynana, the heliconian Heliconius melpomene, the small white Pieris rapae and the small copper Lycaena phlaeas. The colour of the eye shine is determined mainly by the reflectance spectrum of the tapetal mirror and the transmittance spectrum of the photoreceptor screening pigments, if present near the light-guiding rhabdom. Reflectance spectra measured from individual ommatidia show that tapetum and screening pigments are co-expressed in fixed combinations, thus determining different ommatidial classes. The classes are distributed in an irregular pattern that can be rapidly assessed with the novel epi-illumination apparatus. Many butterfly species appear to have red-reflecting ommatidia, which is interpreted to indicate the presence of red-sensitive photoreceptors. PMID:11919267

  2. [Posterior iris bowing after accommodation--elucidation of the etiology of pigment dispersion syndrome].

    PubMed

    Ueda, J; Sawaguchi, S; Watanabe, J; Shirakashi, M; Abe, H

    1997-02-01

    Recent advancements in imaging the anterior segment structures using the ultrasound biomicro scope (UBM) have proven the involvement of posterior iris bowing due to reverse pupillary block as the cause of pigment dispersion syndrome. In this report, we examined whether the posterior iris bowing occurs even in normal eyes following accommodation, and whether the degree of iris concavity tends to be greater in myopic eyes than in emmetropic eyes. The subjects were normal eyes with sufficient accommodation power, i.e. 5 myopic eyes with less than-5 diopter reflection, 5 emmetropic eyes within +/- 1 dioptor reflection, respectively. We obtained UBM images of the iris at 4 portions before and after accommodation, and measured the degree of posterior iris bowing. We found that almost all data shift posteriorly after accommodation, and that the iris concavity is more distinct in myopic eyes than in emmetropic eyes both before and after accommodation (before: p = 0.0004, after: p < 0.0001). From these results, we confirmed that iris concavity after accommodation occurs in normal eyes but not enough for iridozonular contact, and that pigment dispersion syndrome results from augmented iris concavity owing to pre-existing factors such as iris flexibility, myopia, and sufficient accommodation power. PMID:9124102

  3. Dual-modal whole eye photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Wu, Ning; Ren, Qiushi; Li, Changhui

    2014-09-01

    We developed a prototype dual-modal ocular imaging system integrating optical-resolution photoacoustic microscopy and high-frequency ultrasound imaging modalities. This system can perform high-resolution ocular imaging from the anterior region down to the fundus area. The novel system successfully imaged the murine eyes in vivo, including iris, lens, retina, and retinal pigment epithelium. Our results demonstrated that this system has a great potential in the diagnosis of ophthalmic diseases.

  4. Ritonavir and bull’s eye maculopathy: case report

    PubMed Central

    Pinto, Rita; Vila-Franca, Marta; Oliveira Afonso, Cláudia; Ornelas, Conceição; Santos, Luisa

    2013-01-01

    Objective: To report on a case of retinal pigment epithelium (RPE) toxicity apparently associated with ritonavir. Methods: We describe a case of gradual-onset blurry vision in both eyes in a 30-year-old HIV-positive male on Highly-Active Antiretroviral Therapy (HAART) including ritonavir Results: The patient presented with a visual acuity of 3/10 in each eye, and fundoscopy revealed paracentral pigment mottling. Computerized perimetry showed a ring-scotoma in both eyes. Fluorescein angiography revealed an anular RPE defect in both eyes, congruent with hyperautofluorescent changes on autofluorescence imaging. Full-field ERG was normal. Conclusions: Since ritonavir has previously been linked with toxicity to the RPE, we consider this report as further evidence of this association.

  5. Dilating Eye Drops

    MedlinePlus

    ... Conditions Most Common Searches Adult Strabismus Amblyopia Cataract Conjunctivitis Corneal Abrasions Dilating Eye Drops Lazy eye (defined) ... Loading... Most Common Searches Adult Strabismus Amblyopia Cataract Conjunctivitis Corneal Abrasions Dilating Eye Drops Lazy eye (defined) ...

  6. Eye muscle repair - discharge

    MedlinePlus

    ... Lazy eye repair - discharge; Strabismus repair - discharge; Extraocular muscle surgery - discharge ... You or your child had eye muscle repair surgery to correct eye muscle ... term for crossed eyes is strabismus. Children most often ...

  7. Eye Movement Disorders

    MedlinePlus

    ... t work properly. There are many kinds of eye movement disorders. Two common ones are Strabismus - a disorder ... of the eyes, sometimes called "dancing eyes" Some eye movement disorders are present at birth. Others develop over ...

  8. Why Do Eyes Water?

    MedlinePlus

    ... Help White House Lunch Recipes Why Do Eyes Water? KidsHealth > For Kids > Why Do Eyes Water? Print ... out of your nose. continue Why Do Eyes Water? Eyes water for lots of different reasons besides ...

  9. Nonphotosynthetic pigments as potential biosignatures.

    PubMed

    Schwieterman, Edward W; Cockell, Charles S; Meadows, Victoria S

    2015-05-01

    Previous work on possible surface reflectance biosignatures for Earth-like planets has typically focused on analogues to spectral features produced by photosynthetic organisms on Earth, such as the vegetation red edge. Although oxygenic photosynthesis, facilitated by pigments evolved to capture photons, is the dominant metabolism on our planet, pigmentation has evolved for multiple purposes to adapt organisms to their environment. We present an interdisciplinary study of the diversity and detectability of nonphotosynthetic pigments as biosignatures, which includes a description of environments that host nonphotosynthetic biologically pigmented surfaces, and a lab-based experimental analysis of the spectral and broadband color diversity of pigmented organisms on Earth. We test the utility of broadband color to distinguish between Earth-like planets with significant coverage of nonphotosynthetic pigments and those with photosynthetic or nonbiological surfaces, using both 1-D and 3-D spectral models. We demonstrate that, given sufficient surface coverage, nonphotosynthetic pigments could significantly impact the disk-averaged spectrum of a planet. However, we find that due to the possible diversity of organisms and environments, and the confounding effects of the atmosphere and clouds, determination of substantial coverage by biologically produced pigments would be difficult with broadband colors alone and would likely require spectrally resolved data. PMID:25941875

  10. Comparative chromatography of chloroplast pigment

    NASA Technical Reports Server (NTRS)

    Grandolfo, M.; Sherma, J.; Strain, H. H.

    1969-01-01

    Methods for isolation of low concentration pigments of the cocklebur species are described. The methods entail two step chromatography so that the different sorption properties of the various pigments in varying column parameters can be utilized. Columnar and thin layer methods are compared. Many conditions influence separability of the chloroplasts.

  11. Nonphotosynthetic Pigments as Potential Biosignatures

    PubMed Central

    Cockell, Charles S.; Meadows, Victoria S.

    2015-01-01

    Abstract Previous work on possible surface reflectance biosignatures for Earth-like planets has typically focused on analogues to spectral features produced by photosynthetic organisms on Earth, such as the vegetation red edge. Although oxygenic photosynthesis, facilitated by pigments evolved to capture photons, is the dominant metabolism on our planet, pigmentation has evolved for multiple purposes to adapt organisms to their environment. We present an interdisciplinary study of the diversity and detectability of nonphotosynthetic pigments as biosignatures, which includes a description of environments that host nonphotosynthetic biologically pigmented surfaces, and a lab-based experimental analysis of the spectral and broadband color diversity of pigmented organisms on Earth. We test the utility of broadband color to distinguish between Earth-like planets with significant coverage of nonphotosynthetic pigments and those with photosynthetic or nonbiological surfaces, using both 1-D and 3-D spectral models. We demonstrate that, given sufficient surface coverage, nonphotosynthetic pigments could significantly impact the disk-averaged spectrum of a planet. However, we find that due to the possible diversity of organisms and environments, and the confounding effects of the atmosphere and clouds, determination of substantial coverage by biologically produced pigments would be difficult with broadband colors alone and would likely require spectrally resolved data. Key Words: Biosignatures—Exoplanets—Halophiles—Pigmentation—Reflectance spectroscopy—Spectral models. Astrobiology 15, 341–361. PMID:25941875

  12. New directions in phthalocyanine pigments

    NASA Technical Reports Server (NTRS)

    Trinh, Diep VO

    1994-01-01

    Phthalocyanines have been used as a pigment in coatings and related applications for many years. These pigments are some of the most stable organic pigments known. The phthalo blue and green pigments have been known to be ultraviolet (UV) stable and thermally stable to over 400 C. These phthalocyanines are both a semiconductor and photoconductor, exhibiting catalytic activity and photostabilization capability of polymers. Many metal free and metallic phthalocyanine derivatives have been prepared. Development of the new classes of phthalocyanine pigment could be used as coating on NASA spacecraft material such as glass to decrease the optical degradation from UV light, the outside of the space station modules for UV protection, and coating on solar cells to increase lifetime and efficiency.

  13. Resveratrol inhibits epithelial-mesenchymal transition of retinal pigment epithelium and development of proliferative vitreoretinopathy

    PubMed Central

    Ishikawa, Keijiro; He, Shikun; Terasaki, Hiroto; Nazari, Hossein; Zhang, Huiming; Spee, Christine; Kannan, Ram; Hinton, David R

    2015-01-01

    Proliferative vitreoretinopathy (PVR) is a serious complication of retinal detachment and ocular trauma, and its recurrence may lead to irreversible vision loss. Epithelial to mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells is a critical step in the pathogenesis of PVR, which is characterized by fibrotic membrane formation and traction retinal detachment. In this study, we investigated the potential impact of resveratrol (RESV) on EMT and the fibrotic process in cultured RPE cells and further examined the preventive effect of RESV on PVR development using a rabbit model of PVR. We found that RESV induces mesenchymal to epithelial transition (MET) and inhibits transforming growth factor-β2(TGF-β2)-induced EMT of RPE cells by deacetylating SMAD4. The effect of RESV on MET was dependent on sirtuin1 activation. RESV suppressed proliferation, migration and fibronectin synthesis induced by platelet-derived growth factor-BB or TGF-β2. In vivo, RESV inhibited the progression of experimental PVR in rabbit eyes. Histological findings showed that RESV reduced fibrotic membrane formation and decreased α-SMA expression in the epiretinal membranes. These results suggest the potential use of RESV as a therapeutic agent to prevent the development of PVR by targeting EMT of RPE. PMID:26552368

  14. [INHERITANCE OF EPIDERMIS PIGMENTATION IN SUNFLOWER ACHENES].

    PubMed

    Gorohivets, N A; Vedmedeva, E V

    2016-01-01

    Inheritance of epidermis pigmentation in the pericarp of sunflower seeds was studied. Inheritance of pigmentation was confirmed by three alleles Ew (epidermis devoid of pigmentation), Estr (epidermal pigmentation in strips), Edg (solid pigmentation). Dominance of the lack of epidermis pigmentation over striped epidermis and striped epidermis over solid pigmentation was established. It was shown that the striped epidermis pigmentation and the presence of testa layer are controlled by two genes, expression of which is independent from each other. Yellowish hypodermis was discovered in the sample I2K2218, which is inherited monogenically dominantly. PMID:27281924

  15. Natural pigments and sacred art

    NASA Astrophysics Data System (ADS)

    Kelekian, Lena, ,, Lady

    2010-05-01

    Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The

  16. [Sepsis caused by pigmented and no pigmented Chromobacterium violaceum].

    PubMed

    Guevara, Armando; Salomón, Marlly; Oliveros, María; Guevara, Esmirna; Guevara, Milarys; Medina, Laida

    2007-10-01

    Chromobacterium violaceum sepsis is rare but associated with a high mortality rate. We report a fatal case of C. violaceum sepsis in a 6 years old Venezuelan indian boy. Clinical manifestations were fever and swelling in the right inguinal region. The initial diagnosis was an appendicular plastron. Appendicectomy was performed and during surgery a right psoas abscess was identified that resulted culture positive for pigmented C. violaceum. Blood cultures were positive for a pigmented and non pigmented C. violaceum strain. Imipenem and amikacin were administered despite of which the child died 9 days after hospital admission. PMID:17989847

  17. [Regulatory proteins of vertebrate eye tissues].

    PubMed

    Krasnov, M S; Grigorian, E N; Iamskova, V P; Boguslavskiĭ, D V; Iamskov, I A

    2003-01-01

    In our work the new proteins likely belonged to the microenvironment of pigmented epithelium cells and retinal neurons in mammalian eye were studied. We attempted to understand the role of these proteins in the maintenance of normal morphological and functional state of these eye tissues. Earlier for the first time we identified the adhesion molecules with physico-chemical and biological properties much different from other known cell adhesion molecules of bovine eye. Probably, they represent one family of low molecular weigh, highly glicosylated proteins, that express biological activity in extremely low doses--10(-10) mg/ml. The homogeneity of studying proteins is confirmed by HPLC and SDS-electrophoresis in PAAG. It is shown also that these proteins are N-glycosylated, because they contain mannose and N-acetilglucosamine residues. They demonstrate as well a high calcium-binding activity, with Kd corresponded to 10(-4)-10(-6) mg/ml. For a study of the biological effect of these glycoproteins in extremely low doses, a new experimental model was proposed and developed. It was the cultivation in vitro of the posterior part of the eye obtained from the newt Pleurodeles waltl. In short-time culture system it was demonstrated that the studied glycoproteins could stabilize pigment epithelium cell differentiation and cellular interactions in the neural retina in vitro. In addition, glycoproteins, obtained from the pigmented epithelium of bovine eye could decrease the rate of bipolar cell apoptosis in the neural retina. Therefore, the novel adhesion glycoproteins, expressing their biological activity in extremely low doses, pretend to be the regulatory molecules with vivid gomeostatic effects necessary for the delicate adjustment of cell behavior action and function in sensory tissues. PMID:12881976

  18. Effects of low-level laser therapy, electroacupuncture, and radiofrequency on the pigmentation and skin tone of adult women.

    PubMed

    Kim, Hee-Kyoung; Min, Kyoung-Ok; Choi, Jung-Hyun; Kim, Soon-Hee

    2016-05-01

    [Purpose] In this study, the effects of low-level laser therapy (LLLT), electroacupuncture (EA), and radiofrequency (RF), which are used in physical therapy, on the pigmentation and skin tone of adult women's faces were investigated to provide basic data for skin interventions. [Subjects and Methods] Thirty adult females were assigned to either an LLLT group (n=10), an EA group (n=10), or an RF group (n=10). The intervention was performed in two 15-minute sessions per week for six weeks. Subjects' skin tone and pigmentation were observed before and after the intervention. [Results] The EA group showed significant reductions in pigmentation in the left and right eye rims, as well as in the left cheek. The RF group showed significant post-intervention reductions in pigmentation under the left eye, as well as in the left and right eye rims and the left cheek. The LLLT group showed significant increases in skin tone in the forehead and both eye rims. The RF group showed significant increases in skin tone under both eyes. [Conclusion] The application of LLLT, EA, and RF had positive effects on pigmentation and skin tone of adult women's faces. PMID:27313340

  19. Effects of low-level laser therapy, electroacupuncture, and radiofrequency on the pigmentation and skin tone of adult women

    PubMed Central

    Kim, Hee-Kyoung; Min, Kyoung-Ok; Choi, Jung-Hyun; Kim, Soon-Hee

    2016-01-01

    [Purpose] In this study, the effects of low-level laser therapy (LLLT), electroacupuncture (EA), and radiofrequency (RF), which are used in physical therapy, on the pigmentation and skin tone of adult women’s faces were investigated to provide basic data for skin interventions. [Subjects and Methods] Thirty adult females were assigned to either an LLLT group (n=10), an EA group (n=10), or an RF group (n=10). The intervention was performed in two 15-minute sessions per week for six weeks. Subjects’ skin tone and pigmentation were observed before and after the intervention. [Results] The EA group showed significant reductions in pigmentation in the left and right eye rims, as well as in the left cheek. The RF group showed significant post-intervention reductions in pigmentation under the left eye, as well as in the left and right eye rims and the left cheek. The LLLT group showed significant increases in skin tone in the forehead and both eye rims. The RF group showed significant increases in skin tone under both eyes. [Conclusion] The application of LLLT, EA, and RF had positive effects on pigmentation and skin tone of adult women’s faces. PMID:27313340

  20. Shyness and little boy blue: iris pigmentation, gender, and social wariness in preschoolers.

    PubMed

    Coplan, R J; Coleman, B; Rubin, K H

    1998-01-01

    In recent years, researchers have uncovered a link between iris pigmentation and inhibition/social wariness among young children (e.g., Rosenberg & Kagan, 1987, 1989; Rubin & Both, 1989). In the present study, 152 Caucasian preschool-aged (Mage = 54.09 months, SD = 5.84) children (77 males) with either blue (n = 84) or brown (n = 68) eyes, were compared in terms of parental and teacher ratings of social wariness, social play, and aggression. A significant Eye Color x Gender Interaction was found in terms of indices of social wariness; blue-eyed males were rated as more socially wary than brown-eyed males, while blue- and brown-eyed females did not differ in this regard. These results supported the notion that eye color is a marker variable for social wariness in young children. PMID:9452906

  1. Genotype-phenotype associations and human eye color.

    PubMed

    White, Désirée; Rabago-Smith, Montserrat

    2011-01-01

    Although eye color is usually modeled as a simple, Mendelian trait, further research and observation has indicated that eye color does not follow the classical paths of inheritance. Eye color phenotypes demonstrate both epistasis and incomplete dominance. Although there are about 16 different genes responsible for eye color, it is mostly attributed to two adjacent genes on chromosome 15, hect domain and RCC1-like domain-containing protein 2 (HERC2) and ocular albinism (that is, oculocutaneous albinism II (OCA2)). An intron in HERC2 contains the promoter region for OCA2, affecting its expression. Therefore, single-nucleotide polymorphisms in either of these two genes have a large role in the eye color of an individual. Furthermore, with all genetic expression, aberration also occurs. Some individuals may express two phenotypes--one in each eye--or a complete lack of pigmentation, ocular albinism. In addition, the evolutionary and population roles of the different expressions are significant. PMID:20944644

  2. What Is Eye Cancer?

    MedlinePlus

    ... more common than intraocular melanomas. Melanomas develop from pigment-making cells called melanocytes . When melanoma develops in ... uvea). Choroid cells make the same kind of pigment as melanocytes in the skin, so it’s not ...

  3. Efficient transgenesis mediated by pigmentation rescue in zebrafish.

    PubMed

    Harrold, Itrat; Carbonneau, Seth; Moore, Bethany M; Nguyen, Gina; Anderson, Nicole M; Saini, Amandeep S; Kanki, John P; Jette, Cicely A; Feng, Hui

    2016-01-01

    The zebrafish represents a revolutionary tool in large-scale genetic and small-molecule screens for gene and drug discovery. Transgenic zebrafish are often utilized in these screens. Many transgenic fish lines are maintained in the heterozygous state due to the lethality associated with homozygosity; thus, their progeny must be sorted to ensure a population expressing the transgene of interest for use in screens. Sorting transgenic embryos under a fluorescence microscope is very labor-intensive and demands fine-tuned motor skills. Here we report an efficient transgenic method of utilizing pigmentation rescue of nacre mutant fish for accurate naked-eye identification of both mosaic founders and stable transgenic zebrafish. This was accomplished by co-injecting two constructs with the I-SceI meganuclease enzyme into pigmentless nacre embryos: I-SceI-mitfa:mitfa-I-SceI to rescue the pigmentation and I-SceI-zpromoter:gene-of-interest-I-SceI to express the gene of interest under a zebrafish promoter (zpromoter). Pigmentation rescue reliably predicted transgene integration. Compared with other transgenic techniques, our approach significantly increases the overall percentage of founders and facilitates accurate naked-eye identification of stable transgenic fish, greatly reducing laborious fluorescence microscope sorting and PCR genotyping. Thus, this approach is ideal for generating transgenic fish for large-scale screens. PMID:26757807

  4. Don't it make my blue eyes brown: heterochromia and other abnormalities of the iris.

    PubMed

    Rennie, I G

    2012-01-01

    Eye colour is one of the most important characteristics in determining facial appearance. In this paper I shall discuss the anatomy and genetics of normal eye colour, together with a wide and diverse range of conditions that may produce an alteration in normal iris pigmentation or form. PMID:21979861

  5. Don't it make my blue eyes brown: heterochromia and other abnormalities of the iris

    PubMed Central

    Rennie, I G

    2012-01-01

    Eye colour is one of the most important characteristics in determining facial appearance. In this paper I shall discuss the anatomy and genetics of normal eye colour, together with a wide and diverse range of conditions that may produce an alteration in normal iris pigmentation or form. PMID:21979861

  6. Monitoring the accumulation of lipofuscin in aging murine eyes by fluorescence spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The integrated fluorescence of murine eyes is collected as a function of age. This fluorescence is attributed to pigments generally referred to as lipofuscin and is observed to increase with age. No difference in fluorescence intensity is observed between the eyes of males or females. This work p...

  7. Die Pigmente der antiken Malerei

    NASA Astrophysics Data System (ADS)

    Riederer, J.

    1982-02-01

    Scientific analysis of painted antique objects provides us with information about the pigments used in earlier periods of history. Beginning in prehistoric times, coloured earths and minerals were used exclusively until the 3rd millenium B.C. when an extensive production of artificial pigments started. Following Egyptian Blue, a potassium copper chloride, cobalt blue, and a cobalt aluminium oxide was invented but used only over a short period, until it was reinvented 200 years ago. In the Greecian and Roman times the palette was considerably enlarged by the use of other coloured minerals and artificially prepared pigments.

  8. ADENOCARCINOMA OF THE RETINAL PIGMENT EPITHELIUM IN THE GUPPY POECILIA RETICULATA PETERS

    EPA Science Inventory

    A single case of adenocarcinoma of the retinal pigment epithelium occurred in a guppy, Poecilia reticulata Peters. his is the first such tumor reported from fishes. he left eye of the affected fish was severely exophthalmic because of a large intraocular tumor mass. he tumor, whi...

  9. Gold: a unique pigmentation defective laboratory strain of the lady beetle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A laboratory colony of Coleomegilla maculata (DeGeer) was selected for a novel phenotypic color trait. The phenotype was paler in color than the wild type, although not as pale as a previously described mutant strain, yellow (ye), and retained dark pigmentation in the eyes. This selected strain was ...

  10. Pigment Deposition of Cosmetic Contact Lenses on the Cornea after Intense Pulsed-Light Treatment

    PubMed Central

    Hong, Sojin; Lee, Jong Rak

    2010-01-01

    We report a case of corneal deposition of pigments from cosmetic contact lenses after intense pulsed-light (IPL) therapy. A 30-year-old female visited our outpatient clinic with ocular pain and epiphora in both eyes; these symptoms developed soon after she had undergone facial IPL treatment. She was wearing cosmetic contact lenses throughout the IPL procedure. At presentation, her uncorrected visual acuity was 2/20 in both eyes, and the slit-lamp examination revealed deposition of the color pigment of the cosmetic contact lens onto the corneal epithelium. We scraped the corneal epithelium along with the deposited pigments using a no. 15 blade; seven days after the procedure, the corneal epithelium had healed without any complications. This case highlights the importance of considering the possibility of ocular complications during IPL treatment, particularly in individuals using contact lenses. To prevent ocular damage, IPL procedures should be performed only after removing the lenses and applying eyeshields. PMID:21165237

  11. Historic perspectives. Macular yellow pigment. The first 200 years.

    PubMed

    Nussbaum, J J; Pruett, R C; Delori, F C

    1981-01-01

    Since 1782 there has been continuing controversy concerning the curious central coloration referred to as "macular yellow," but no cumulative source of information on the subject exists. This paper reviews the research efforts of two centuries to determine the existence, nature, location, and function of a specialized pigment in the foveal region. Using white-light illumination, it is difficult to see a macular yellow spot in the living eye; it is best observed and documented by red-free ophthalmoscopy and blue-light monochromatic photography. Histologic, biochemical, and spectral absorption data suggest that the yellow color is due to a xanthophyllic pigment, lutein, that is distributed in all retinal layers internal to the outer nuclear layer, with greatest concentration in the outer and inner plexiform layers. Clinically absent in newborns, the pigment gradually accumulates from dietary sources and appears to serve both as an optical filter, by absorbing blue light and reducing chromatic aberration, and in a protective capacity, preventing actinic damage. The absorption characteristics of the yellow pigment contribute to the central dark spot seen during fluorescein angiography and to the risk of photocoagulation near the fovea. Its apparent absence in albinos and the reported functional improvement in certain degenerative retinopathies following supplemental xanthophyll administration suggest a possible role in hereditary or acquired maculopathies. PMID:6758089

  12. EXPLORING RPE AS A SOURCE OF PHOTORECEPTORS: DIFFERENTIATION AND INTEGRATION OF TRANSDIFFERENTIATING CELLS GRAFTED INTO EMBRYONIC CHICK EYES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The possibility of generating photoreceptors through programming retina pigment epithelium (RPE) transdifferentiation by examining cell differentiation after transplantation into the developing chicken eye was examined. RPE cells were dissociated, cultured, and guided to transdifferentiate by infec...

  13. Yolk pigments of the Mexican leaf frog.

    PubMed

    Marinetti, G V; Bagnara, J T

    1983-02-25

    Eggs of the Mexican leaf frog contain blue and yellow pigments identified as biliverdin and lutein, respectively. Both pigments are bound to proteins that occur in crystalline form in the yolk platelet. The major blue pigment is biliverdin IX alpha. The eggs vary in color from brilliant blue to pale yellow-green depending on the amount of each pigment. These pigments may provide protective coloration to the eggs. PMID:6681678

  14. Diabetes eye exams

    MedlinePlus

    ... catch problems early if you get regular eye exams. ... diabetes checks your eyes, you need an eye exam every 1 to 2 years by an eye ... problems with your vision. Many can do screening exams for damage from diabetes. Once you have eye ...

  15. Oil droplets of bird eyes: microlenses acting as spectral filters

    PubMed Central

    Stavenga, Doekele G.; Wilts, Bodo D.

    2014-01-01

    An important component of the cone photoreceptors of bird eyes is the oil droplets located in front of the visual-pigment-containing outer segments. The droplets vary in colour and are transparent, clear, pale or rather intensely yellow or red owing to various concentrations of carotenoid pigments. Quantitative modelling of the filter characteristics using known carotenoid pigment spectra indicates that the pigments’ absorption spectra are modified by the high concentrations that are present in the yellow and red droplets. The high carotenoid concentrations not only cause strong spectral filtering but also a distinctly increased refractive index at longer wavelengths. The oil droplets therefore act as powerful spherical microlenses, effectively channelling the spectrally filtered light into the photoreceptor's outer segment, possibly thereby compensating for the light loss caused by the spectral filtering. The spectral filtering causes narrow-band photoreceptor spectral sensitivities, which are well suited for spectral discrimination, especially in birds that have feathers coloured by carotenoid pigments. PMID:24395968

  16. Cell migration.

    PubMed

    Trepat, Xavier; Chen, Zaozao; Jacobson, Ken

    2012-10-01

    Cell migration is fundamental to establishing and maintaining the proper organization of multicellular organisms. Morphogenesis can be viewed as a consequence, in part, of cell locomotion, from large-scale migrations of epithelial sheets during gastrulation, to the movement of individual cells during development of the nervous system. In an adult organism, cell migration is essential for proper immune response, wound repair, and tissue homeostasis, while aberrant cell migration is found in various pathologies. Indeed, as our knowledge of migration increases, we can look forward to, for example, abating the spread of highly malignant cancer cells, retarding the invasion of white cells in the inflammatory process, or enhancing the healing of wounds. This article is organized in two main sections. The first section is devoted to the single-cell migrating in isolation such as occurs when leukocytes migrate during the immune response or when fibroblasts squeeze through connective tissue. The second section is devoted to cells collectively migrating as part of multicellular clusters or sheets. This second type of migration is prevalent in development, wound healing, and in some forms of cancer metastasis. PMID:23720251

  17. Cell Migration

    PubMed Central

    Trepat, Xavier; Chen, Zaozao; Jacobson, Ken

    2015-01-01

    Cell migration is fundamental to establishing and maintaining the proper organization of multicellular organisms. Morphogenesis can be viewed as a consequence, in part, of cell locomotion, from large-scale migrations of epithelial sheets during gastrulation, to the movement of individual cells during development of the nervous system. In an adult organism, cell migration is essential for proper immune response, wound repair, and tissue homeostasis, while aberrant cell migration is found in various pathologies. Indeed, as our knowledge of migration increases, we can look forward to, for example, abating the spread of highly malignant cancer cells, retarding the invasion of white cells in the inflammatory process, or enhancing the healing of wounds. This article is organized in two main sections. The first section is devoted to the single-cell migrating in isolation such as occurs when leukocytes migrate during the immune response or when fibroblasts squeeze through connective tissue. The second section is devoted to cells collectively migrating as part of multicellular clusters or sheets. This second type of migration is prevalent in development, wound healing, and in some forms of cancer metastasis. PMID:23720251

  18. Assembly of the cnidarian camera-type eye from vertebrate-like components

    PubMed Central

    Kozmik, Zbynek; Ruzickova, Jana; Jonasova, Kristyna; Matsumoto, Yoshifumi; Vopalensky, Pavel; Kozmikova, Iryna; Strnad, Hynek; Kawamura, Shoji; Piatigorsky, Joram; Paces, Vaclav; Vlcek, Cestmir

    2008-01-01

    Animal eyes are morphologically diverse. Their assembly, however, always relies on the same basic principle, i.e., photoreceptors located in the vicinity of dark shielding pigment. Cnidaria as the likely sister group to the Bilateria are the earliest branching phylum with a well developed visual system. Here, we show that camera-type eyes of the cubozoan jellyfish, Tripedalia cystophora, use genetic building blocks typical of vertebrate eyes, namely, a ciliary phototransduction cascade and melanogenic pathway. Our findings indicative of parallelism provide an insight into eye evolution. Combined, the available data favor the possibility that vertebrate and cubozoan eyes arose by independent recruitment of orthologous genes during evolution. PMID:18577593

  19. In vivo laser-induced breakdown in the rabbit eye

    NASA Astrophysics Data System (ADS)

    Cain, Clarence P.; DiCarlo, Cheryl D.; Kennedy, Paul K.; Noojin, Gary D.; Amnotte, Rodney E.; Roach, William P.

    1995-05-01

    Threshold measurements for femtosecond laser pulsewidths have been made for retinal minimum visible lesions (MVLs) in Dutch Belted rabbit and rhesus monkey eyes. Laser-induced breakdown (LIB) thresholds in biological materials including vitreous, normal saline, tap water, and ultrapure water have been measured and reported using an artificial eye. We have recorded on video the first LIB causing bubble formation in any eye in vivo using albino rabbit eyes (New Zealand white) with 120- femtosecond (fs) pulses and pulse energies as low as 5 microjoules ((mu) J). These bubbles were clearly formed anterior to the retina within the vitreous humor and, with 60 (mu) J of energy, they lasted for several seconds before disappearing and leaving no apparent damage to the retina. We believe this to be true LIB because of the lack of pigmentation or melanin granules within the albino rabbit eye (thus no absorptive elements) and because of the extremely high peak powers within the 5-(mu) J, 120-fs laser pulse. These high peak powers produce self-focusing of the pulse within the vitreous. The bubble formation at the breakdown site acts as a limiting mechanism for energy transmission and may explain why high-energy femotsecond pulses at energies up to 100 (mu) J sometimes do not cause severe damage in the pigmented rabbit eye. This fact may also explain why it is so difficult to produce hemorrhagic lesions in either the rabbit or primate eye with 100-fs laser pulses.

  20. Hormonal regulation of colour change in eyes of a cryptic fish

    PubMed Central

    Sköld, Helen Nilsson; Yngsell, Daniel; Mubashishir, Muhmd; Wallin, Margareta

    2015-01-01

    ABSTRACT Colour change of the skin in lower vertebrates such as fish has been a subject of great scientific and public interest. However, colour change also takes place in eyes of fish and while an increasing amount of data indicates its importance in behaviour, very little is known about its regulation. Here, we report that both eye and skin coloration change in response to white to black background adaptation in live sand goby Pomatoschistus minutes, a bentic marine fish. Through in vitro experiments, we show that noradrenaline and melanocyte concentrating hormone (MCH) treatments cause aggregation of pigment organelles in the eye chromatophores. Daylight had no aggregating effect. Combining forskolin to elevate intracellular cyclic adenosine monophosphate (cAMP) with MCH resulted in complete pigment dispersal and darkening of the eyes, whereas combining prolactin, adrenocorticotrophic hormone (ACTH) or melanocyte stimulating hormone (α-MSH) with MCH resulted in more yellow and red eyes. ACTH and MSH also induced dispersal in the melanophores, resulting in overall darker eyes. By comparing analysis of eyes, skin and peritoneum, we conclude that the regulation pattern is similar between these different tissues in this species which is relevant for the cryptic life strategy of this species. With the exception of ACTH which resulted in most prominent melanophore pigment dispersal in the eyes, all other treatments provided similar results between tissue types. To our knowledge, this is the first study that has directly analysed hormonal regulation of physiological colour change in eyes of fish. PMID:25596278

  1. Eye muscle repair - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000111.htm Eye muscle repair - discharge To use the sharing features on ... enable JavaScript. You or your child had eye muscle repair surgery to correct eye muscle problems that ...

  2. Eye muscle repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100062.htm Eye muscle repair - series—Normal anatomy To use the sharing ... the eyeball to the eye socket. The external muscles of the eye are found behind the conjunctiva. ...

  3. Dilating Eye Drops

    MedlinePlus

    ... Frequently Asked Questions Español Condiciones Chinese Conditions Dilating Eye Drops En Español Read in Chinese What are dilating eye drops? Dilating eye drops contain medication to enlarge ( ...

  4. Fluorescent eye test (image)

    MedlinePlus

    The fluorescent eye test is useful in determining if there is a scratch or other problem with the surface ... has thoroughly covered the eye a cobalt blue light is then directed on the eye. The light ...

  5. Retinal pigment epithelial expression of complement regulator CD46 is altered early in the course of geographic atrophy.

    PubMed

    Vogt, Susan D; Curcio, Christine A; Wang, Lan; Li, Chuan-Ming; McGwin, Gerald; Medeiros, Nancy E; Philp, Nancy J; Kimble, James A; Read, Russell W

    2011-10-01

    In geographic atrophy (GA), the non-neovascular end stage of age-related macular degeneration (AMD), the macular retinal pigment epithelium (RPE) progressively degenerates. Membrane cofactor protein (MCP, CD46) is the only membrane-bound regulator of complement expressed on the human RPE basolateral surface. Based on evidence of the role of complement in AMD, we hypothesized that altered CD46 expression on the RPE would be associated with GA development and/or progression. Here we report the timeline of CD46 protein expression changes across the GA transition zone, relative to control eyes, and relative to events in other chorioretinal layers. Eleven donor eyes (mean age 87.0 ± 4.1 yr) with GA and 5 control eyes (mean age 84.0 ± 8.9 yr) without GA were evaluated. Macular cryosections were stained with PASH for basal deposits, von Kossa for calcium, and for CD46 immunoreactivity. Internal controls for protein expression were provided by an independent basolateral protein, monocarboxylate transporter 3 (MCT3) and an apical protein, ezrin. Within zones defined by 8 different semi-quantitative grades of RPE morphology, we determined the location and intensity of immunoreactivity, outer segment length, and Bruch's membrane calcification. Differences between GA and control eyes and between milder and more severe RPE stages in GA eyes were assessed statistically. Increasing grades of RPE degeneration were associated with progressive loss of polarity and loss of intensity of staining of CD46, beginning with the stages that are considered normal aging (grades 0-1). Those GA stages with affected CD46 immunoreactivity exhibited basal laminar deposit, still-normal photoreceptors, and concomitant changes in control protein expression. Activated or anteriorly migrated RPE (grades 2-3) exhibited greatly diminished CD46. Changes in RPE CD46 expression thus occur early in GA, before there is evidence of morphological RPE change. At later stages of degeneration, CD46

  6. Eyeing Ganymede

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Jupiter casts a baleful eye toward the moon Ganymede in this enhanced-contrast image from NASA's Cassini spacecraft.

    Jupiter's 'eye', the Great Red Spot, was captured just before disappearing around the eastern edge of the planet. The furrowed eyebrow above and to the left of the spot is a turbulent wake region caused by westward flow that has been deflected to the north and around the Red Spot. The smallest features visible are about 240 kilometers (150 miles) across.

    Within the band south of the Red Spot are a trio of white ovals, high pressure counterclockwise-rotating regions that are dynamically similar to the Red Spot. The dark filamentary features interspersed between white ovals are probably cyclonic circulations and, unlike the ovals, are rotating clockwise.

    Jupiter's equatorial zone stretching across the planet north of the Spot appears bright white, with gigantic plume clouds spreading out from the equator both to the northeast and to the southeast in a chevron pattern. This zone looks distinctly different than it did during the Voyager flyby 21 years ago. Then, its color was predominantly brown and the only white plumes conspicuous against the darker material beneath them were oriented southwest-to-northeast.

    Ganymede is Jupiter's largest moon, about 50 percent larger than our own Moon and larger than the planet Mercury. The visible details in this image are different geological terrains. Dark areas tend to be older and heavily cratered; brighter areas are younger and less cratered. Cassini images of Ganymede and Jupiter's other large moons taken near closest approach on Dec. 30 will have resolutions about four times better than that seen here.

    This image is a color composite of ones taken with different filters by Cassini's narrow-angle camera on Nov. 18, 2000, processed to enhance contrast. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of

  7. Multiple pigmented basal cell carcinomas.

    PubMed

    Shoji, T; Lee, J; Hong, S H; Oh, C H; Kim, W K; Bhawan, J

    1998-04-01

    Basal cell carcinoma is the most common of all skin cancers and the most prevalent one among Caucasians. Rarely, these tumors are seen in other races. We report a 77-year-old Korean woman who presented with multiple darkly pigmented enlarging nodules on her scalp, face, trunk, and extremities. The patient had first noted a 6-mm pigmented lesion on her left eyebrow 10 years previously. Since then, other lesions had appeared in many locations on her body. She had been otherwise healthy and without a history of exposure to arsenic or radiation. There was no family history of skin cancer, xeroderma pigmentosum, or basal cell nevus syndrome. On physical examination, multiple darkly pigmented dome-shaped papules and nodules were present on her scalp, face, right forearm, lower abdomen, and inguinal areas. They ranged in size from 0.5 mm to 2 cm. The larger ones showed central ulceration. Multiple biopsy specimens from different sites showed pigmented basal cell carcinomas. Clinically, there was no evidence of nevus sebaceus, xeroderma pigmentosum, basal cell nevus syndrome, or immunodeficiency. Clinical workup including chest radiography, abdominal ultrasound, bone scan, and brain computerized axial tomography scan did not demonstrate primary or secondary tumors. The results of serologic and hematologic tests were also within normal limits. This is an unusual case report of multiple pigmented basal cell carcinomas in an Asian woman without any predisposing risk factors. PMID:9557792

  8. Exogenous pigment in Peyer's patches

    SciTech Connect

    Shepherd, N.A.; Crocker, P.R.; Smith, A.P.; Levison, D.A.

    1987-01-01

    Dark brown granular pigment was found consistently in macrophages in the deep aspect of adult Peyer's patches. Tissue sections from intestinal resections of 35 patients with a variety of pathologic diagnoses and of seven postmortem cases with no evidence of gastrointestinal disease were examined for the presence of this pigment. It was found in all patients over the age of 6 years (34 cases) but was not found in any children below that age (eight cases). Scanning electron microscopy with secondary and backscattered electron imaging and x-ray energy spectroscopy were performed on routine histologic sections. The pigmented macrophages contained aluminum and silicon, diffusely present throughout the cytoplasm, and numerous discrete foci of titanium. Pigment containing these same elements has also been found around dilated submucosal lymphatics, in mesenteric lymph nodes, and in some transmural inflammatory aggregates of Crohn's disease. The pigment probably is derived from the diet and actively taken up by Peyer's patches, which are able to incorporate inert particulate matter.

  9. Pigment Analysis of Chloroplast Pigment-Protein Complexes in Wheat

    PubMed Central

    Eskins, Kenneth; Duysen, Murray E.; Olson, Linda

    1983-01-01

    Pigment-protein complexes separated from wheat (Triticum aestivum L. selection ND96-25 by two gel electrophoresis techniques were analyzed by high-performance liquid chromatography for chlorophylls and carotenoids. The two techniques are compared, and pigment analyses are given for the major reaction centers and light-harvesting complexes. Reaction centers contain mostly chlorophyll a, carotene, and lutein, whereas light-harvesting complexes contain chlorophyll a, chlorophyll b, lutein, and neoxanthin. The amounts of violaxanthin are variable. Images Fig. 1 PMID:16662906

  10. Polypeptide composition of the purified photosystem II pigment-protein complex from spinach.

    PubMed

    Satoh, K

    1979-04-11

    The Photosystem II pigment-protein complex, the chlorophyll alpha-protein comprising the reaction center of Photosystem II, was prepared from EDTA-treated spinach chloroplasts by digitonin extraction, sucrose-gradient centrifugation, DEAE-cellulose column chromatography, and isoelectrofocussing on Ampholine. The dissociated pigment-protein complex exhibits two polypeptide subunits that migrate in SDS-polyacrylamide gel with electrophoretic mobilities corresponding to molecular weights of approximately 43,000 and 27,000. the chlorophyll was always found in the free pigment zone at the completion of the electrophoresis. Heat-treatment of the sample (100 degrees C, 90 s) for electrophoresis caused association of the two polypeptides into large aggregates. It is concluded that these two polypeptides, 43,000 and 27,000, are valid structural or functional components of Photosystem II pigment-protein complex. PMID:444494

  11. Compact single-channel Raman detector for macular pigments

    NASA Astrophysics Data System (ADS)

    Ermakov, Igor V.; Ermakova, Maia R.; Gellermann, Werner

    2004-07-01

    Raman detection of macular pigments (MP) holds promise as a novel noninvasive technology for the quantification of lutein and zeaxanthin carotenoids, which are thought to prevent or delay the onset of age-related macular degeneration. Using resonant excitation in the visible, we measure the Raman signals that originate from the double-bond stretch vibrations of the p-conjugated carotenoid molecule's carbon backbone. In this paper we describe the construction and performance of a new, compact, and low-cost MP Raman instrument using dielectric, angle-tuned band-pass filters for wavelength selection and single-channel photo-multiplier detection of carotenoid Raman responses. MP concentration measurements are fast and accurate, as seen in experiments with model eyes and living human eyes. The ease and rapidity of Raman MP measurements, the relative simplicity of the instrumentation, the high accuracy of the measurements, and the lack of significant systematic errors should make this technology useful for widespread clinical research.

  12. Reduction of Endogenous Angiogenesis Inhibitors in Bruch’s Membrane of the Submacular Region in Eyes With Age-Related Macular Degeneration

    PubMed Central

    Bhutto, Imran A.; Uno, Koichi; Merges, Carol; Zhang, Lei; McLeod, D. Scott; Lutty, Gerard A.

    2016-01-01

    Objectives To determine the relative levels of 3 potent inhibitors of angiogenesis (endostatin, pigment epithelium–derived factor, and thrombospondin 1) in the retinal pigment epithelium–Bruch’s membrane–choriocapillaris complex in the submacular region in aged control eyes and eyes with age-related macular degeneration (AMD). Methods Immunohistochemical analysis with antibodies against endostatin, pigment epithelium–derived factor, and thrombospondin 1 was performed on the macular region of aged control donor eyes (n=8; mean age, 79.8 years) and eyes with AMD (n=12; mean age, 83.9 years). Three independent masked observers scored the reaction product (scored from 0–7). Mean scores from the control eyes and the eyes with AMD were analyzed using 1-way analysis of variance and unpaired t test. Results In control eyes, strong immunoreactivity of all 3 inhibitors was observed in the retinal pigment epithelium–Bruch’s membrane–choriocapillaris complex. Immunoreactivity for endostatin, pigment epithelium–derived factor, and thrombospondin 1 in Bruch’s membrane was significantly lower in eyes with AMD compared with aged control eyes (analysis of variance, P=.003, P = .009, and P< .001, respectively). In the choriocapillaris, a significant reduction was observed in endostatin (analysis of variance, P=.02) and thrombospondin 1 (analysis of variance, P=.005) in eyes with AMD. Conclusions These findings suggest that endogenous angiogenesis inhibitors in the retinal pigment epithelium–Bruch’s membrane–choriocapillaris complex may provide a biochemical barrier for choroidal neovascular invasion. Clinical Relevance Decreased levels of angiogenic inhibitors at the retinal pigment epithelium–Bruch’s membrane–choriocapillaris complex in eyes with AMD make Bruch’s membrane vulnerable to choroidal neovascularization. PMID:18474778

  13. Pigmented Porokeratosis. A Further Variant?

    PubMed

    Tan, Tracy S P; Tallon, Ben

    2016-03-01

    Porokeratosis is a clonal disorder of keratinization characterized by the presence of the cornoid lamella. A number of variants of porokeratosis have been described, based on the clinical features and histologic features of the lesions. The authors present a case of porokeratosis with prominent melanocytic hyperplasia, which was biopsied to clinically exclude melanoma. The authors retrospectively studied cases of porokeratosis to look for the presence of melanocytic hyperplasia. Melanocytic hyperplasia was identified in 8 of 31 cases (25.8%). All of the cases except the index case were clinically nonpigmented but arose in solar damaged skin. This case represents a distinct variant of porokeratosis, and the authors propose the designation pigmented porokeratosis. Melanocytic hyperplasia is a benign condition, and it is important that this is not histologically confused with melanoma in situ, particularly in a context of clinically pigmented lesion. Increased recognition of pigmented porokeratosis is essential to avoid an erroneous diagnosis of melanoma in situ. PMID:26894774

  14. Microprobe analysis of chlorpromazine pigmentation

    SciTech Connect

    Benning, T.L.; McCormack, K.M.; Ingram, P.; Kaplan, D.L.; Shelburne, J.D.

    1988-10-01

    We describe the histochemical, ultrastructural, and microanalytical features of a skin biopsy specimen obtained from a patient with chlorpromazine pigmentation. Golden-brown pigment granules were present in the dermis, predominantly in a perivascular arrangement. The granules stained positively with the Fontana-Masson stain for silver-reducing substances and negatively with Perl's stain for iron. Electron microscopy revealed dense inclusion bodies in dermal histiocytes, pericytes, endothelial cells, and Schwann cells, as well as lying free in the extracellular matrix. These ''chlorpromazine bodies'' were quite dense even in unosmicated, unstained ultrathin sections, indicating that the pigmentation is related, at least in part, to the inclusions. Microprobe analysis of the chlorpromazine bodies revealed a striking peak for sulfur, which strongly suggests the presence of the drug or its metabolite within these inclusions.

  15. Modifications of the falciform process in the eye of beloniformes (Teleostei: Atherinomorpha): evolution of a curtain-like septum in the eye.

    PubMed

    Reckel, Frank; Melzer, Roland R

    2004-04-01

    In order to comparatively analyze curtain-like septa in the eyes of visually orientated "close-to-surface-predators" among atherinomorph teleosts, we examined the eyes of 24 atherinomorph species under a binocular microscope with regard to the falciform process and related structures in the vitreous cavity. Additionally, falciform process samples were analyzed by transmission electron microscopy. All the studied representatives of the Cyprinodontiformes and Atheriniformes, and of one of the beloniform suborder, Adrianichthyioidei, possess a "typical" processus falciformis. In the eyes of the representatives of the other beloniform suborder, Belonoidei, however, pigmented structures that originate in the region of the optic disc and protrude into the vitreous cavity were noted. In the Hemiramphidae (halfbeaks) and Exocoetidae (flying fishes) these pigmented structures have a more cone-like shape, whereas in the Belonidae (needlefishes) and Scomberesocidae (sauries) horizontally oriented heavily pigmented curtain-like septa occur that divide the vitreous cavity dorsoventrally. It is suggested that the "typical" processus falciformis represents a plesiomorphic feature within the Atherinomorpha, whereas the pigmented modifications of the falciform process must be seen as a synapomorphic character state of the Belonoidei. The curtain-like septum of the Belonidae and Scomberesocidae might have evolved from the cone-like structures that are found in the Exocoetoidea. The functional significance of the pigmented structures in the eye is as yet not clear, except for the curtain-like septum found in Belonidae. It might play a role in visual orientation near the water surface at Snell's window. PMID:15052593

  16. Pigment cell localizations in anuran ventral skin at climactic metamorphosis.

    PubMed

    Denèfle, J P; Lechaire, J P

    1991-09-01

    In anuran amphibians, the specific color pattern of the skin is expressed after metamorphosis, and its formation involves pigment cell migrations. Pigment cells are differently distributed in the tadpole, larval, and froglet skin. To learn more about their fate during metamorphic climax and in the young froglet, we focused our attention on the different localizations of larval melanophores and iridophores in the ventral skin of Rana esculenta before and during skin homing. Localizations of melanophores and iridophores can be elucidated at the developmental stages suggested by Taylor and Kollros (TK stages). At TK stage II (during early premetamorphosis), large melanophores beneath the larval skin are detected. At TK stage X, dispersed melanophores lie under bundles of muscular striated fibrils near the larval skin; they are also observed at the vascular level. At TK stage XVII (prometamorphosis), melanophores are extended on the inner side of the basement lamellar collagen. At the end of prometamorphosis, iridophores are located with melanophores in the separating space between attached basement collagen and derived basement collagen. At TK stage XX (earlier climax), melanophores and iridophores are detected inside the upper extremities of fractures opened in the derived basement collagen. At TK stage XXIV (later climax), both types of larval pigment cells are observed in the inner extremities of breaks derived from the fractures. During climax, these pigment cells occupy the well-formed breaks. At TK stage XXV in young froglet, the pigment cells remain alone in the breaks formed in the derived basement collagen. Briefly, breaks in the basement lamellar collagen are opened by invading cell processes of mesenchymal cells.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1750384

  17. Eye muscle repair - series (image)

    MedlinePlus

    ... the eyeball to the eye socket. The external muscles of the eye are found behind the conjunctiva. ... The extraocular muscles of the eye (external to the eyeball) control the positioning of the eyes. They coordinate of the eye ...

  18. Eating for Your Eyes

    ERIC Educational Resources Information Center

    Stastny, Sherri Nordstrom; Garden-Robinson, Julie

    2011-01-01

    An educational program targeting older adults was developed to increase knowledge regarding nutrition and eye health. With age, the chance for eye disease increases, so prevention is critical. The Eating for Your Eyes program has promoted behavior changes regarding eye health among the participants. This program is easily replicated and use is…

  19. Unilateral non-pigmented palpebral conjunctival lesions due to cosmetics use.

    PubMed

    Pao, Kristina Y; Murchison, Ann P; Eagle, Ralph C

    2012-01-01

    A 62-year-old woman with a history of dry eyes was found to have unilateral pedunculated, nonpigmented palpebral conjunctival lesions. Excisional biopsy was performed, and the lesions were studied histopathologically. Microscopic examination of the lesions demonstrated exuberant granulation tissue with a granulomatous foreign body giant cell reaction surrounding pigmented and partially birefringent foreign material. Histopathologic examination of the patient's cosmetics revealed that the pigmented foreign bodies seen on the biopsy specimens were compatible with her mascara and/or eyeliner. While cosmetics have been reported to have ophthalmic sequelae, palpebral lesions such as these have not been reported to the authors' knowledge. PMID:22327635

  20. Does an Association between the Idiopathic Left-Sided Varicocele and Eye Colour Exist?

    PubMed Central

    Kumanov, Philip; Tomova, Analia

    2014-01-01

    The possible interrelation between male reproductive disorders and iris pigmentation is poorly understood. We have found a link between eye colour and the existence of adolescent varicocele. Therefore, we aimed to extend our investigation on the relationship between the eye colour and varicocele in adult men. 231 andrology outpatients from Caucasian origin were included in the study. The presence of varicocele, sperm disturbances, and the iris pigment of the patients were investigated. Left-sided varicocele was found in 93 adults. In the group of light-eyed men the prevalence of varicocele was significantly lower than among the dark-eyed men (15% versus 59.5%, P < 0.001). No associations were found between the eye colour and disturbances in semen parameters in males with varicocele (P = 0.419) and in those without varicocele (P = 0.586). The present results in adult men suggest that the prevalence of varicocele could be associated with the iris pigment. A possible genetic linkage between the eye colour and the susceptibility to some disorders like varicocele could not be excluded. However, the iris pigmentation seems not to have a direct relationship with the sperm disturbances. PMID:24803926

  1. Medical migration.

    PubMed

    Loefler, I J

    2001-10-01

    The issue of professional migration, however emotional it may have become, ought not to be regarded in moralizing terms. The history of western medicine is the history of migrating physicians. A doctor who moves from a locality to another to take up a new assignment there cannot be said to have "abandoned his patients". This emotional bond has become the victim of specialization and of depersonalization of medical services and not of medical migration, brain drain or otherwise. The primary reason for medical migration is not financial; the desire to migrate usually begins with the desire to learn. Professionals crave in the first line for professional satisfaction. The migration of medical manpower cannot be stopped with administrative measures and will not be stopped by exhortations and appeals, moralization and condemnations. Brain drain is a global phenomenon and has always been so. A country which loses its professionals, its doctors, should examine the social relationships within the profession and should investigate whether the opportunities for deriving professional satisfaction from everyday work exist or whether these have been thwarted by the hierarchy, conservatism, cronyism and the general lack of comprehension of what good medical care is about. PMID:11593497

  2. Visual pigment processes and prolonged pupillary responses in insect photoreceptor cells.

    PubMed

    Stavenga, D G

    1979-01-01

    The visual pigment in the peripheral retinular cells of the hoverfly Syrphus balteatus was investigated by absorbance difference measurements. Different visual pigments were found in the dorsal versus the ventral part of the eye in the male, but not in the female. In the male in the dorsal part of the eye the visual pigment has an isosbestic point at 513 nm; in the ventral part this value is 490 nm. The latter value is found in the female in both parts of the eye. Prolonged pupillary responses were studied in the male Syrphus and appeared to be most marked in the ventral part of the eye. In both hoverfly and blowfly prolonged pupillary responses are induced by short wavelength light only; i.e., by light which excessively can convert rhodopsin into metarhodopsin. By contrast, in butterflies red light (and a long dark adaptation time) is necessary to evoke a prolonged pupillary response. It was demonstrated in both hoverfly and blowfly that long wavelength light, which reconverts metarhodopsin into rhodopsin, inhibits a prolonged pupillary response; or, accelerates pupil opening. PMID:22730591

  3. Clofazimine-induced Hair Pigmentation.

    PubMed

    Philip, Mariam; Samson, Joan Felicita; Simi, Puthenveedu Salahudeen

    2012-07-01

    A 45-year-old man was treated with WHO multibacillary multidrug therapy for borderline leprosy and high dose daily Clofazimine for lepra reaction. Along with the expected side effect of skin pigmentation, the patient also noticed darkening of previously grey hair. This colour persisted eight months after completing multibacillary multidrug therapy. PMID:23180930

  4. [Internal migration].

    PubMed

    Borisovna, L

    1991-06-01

    Very few studies have been conducted that truly permit explanation of internal migration and it repercussions on social and economic structure. It is clear however that a profound knowledge of the determinants and consequences of internal migration will be required as a basis for economic policy decisions that advance the goal of improving the level of living of the population. the basic supposition of most studies of the relationship of population and development is that socioeconomic development conditions demographic dynamics. The process of development in Mexico, which can be characterized by great heterogeneity, consequently produces great regional disparities. At the national level various studies have estimated the volume of internal migration in Mexico, but they have usually been limited to interstate migration because the main source of data, the census, is classified by states. But given the great heterogeneity within states in all the elements related to internal migration, it is clear that studies of internal migration within states are also needed. Such studies are almost nonexistent because of their technical difficulty. National level studies show that interstate migration increased significantly between 1940-80. The proportion of Mexicans living outside their states of birth increased by 558% in those years, compared to the 342% increase in the total Mexican population. Although Puebla has a high rate of increase, migration has kept it below Mexico's national growth rate. Migration between Puebla and other states and within Puebla has led to an increasing unevenness of spatial distribution. Between 1970-80, 57 of Puebla's municipios had growth rates above the state average of 2.8%/year, 6 had growth rates equal to the average, and 129 had growth rates that were below the average but not negative. 25 states with negative growth rates that were considered strongly expulsive. In 1980, 51.7% of the population was concentrated in the 57 municipios

  5. 21 CFR 178.3725 - Pigment dispersants.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Pigment dispersants. 178.3725 Section 178.3725... Certain Adjuvants and Production Aids § 178.3725 Pigment dispersants. Subject to the provisions of this regulation, the substances listed in this section may be safely used as pigment dispersants in...

  6. 21 CFR 178.3725 - Pigment dispersants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pigment dispersants. 178.3725 Section 178.3725 Food... Certain Adjuvants and Production Aids § 178.3725 Pigment dispersants. Subject to the provisions of this regulation, the substances listed in this section may be safely used as pigment dispersants in...

  7. 21 CFR 178.3725 - Pigment dispersants.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Pigment dispersants. 178.3725 Section 178.3725... Certain Adjuvants and Production Aids § 178.3725 Pigment dispersants. Subject to the provisions of this regulation, the substances listed in this section may be safely used as pigment dispersants in...

  8. 21 CFR 178.3725 - Pigment dispersants.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Pigment dispersants. 178.3725 Section 178.3725... § 178.3725 Pigment dispersants. Subject to the provisions of this regulation, the substances listed in this section may be safely used as pigment dispersants in food-contact materials....

  9. 21 CFR 178.3725 - Pigment dispersants.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Pigment dispersants. 178.3725 Section 178.3725... Certain Adjuvants and Production Aids § 178.3725 Pigment dispersants. Subject to the provisions of this regulation, the substances listed in this section may be safely used as pigment dispersants in...

  10. 21 CFR 73.352 - Paracoccus pigment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Paracoccus pigment. 73.352 Section 73.352 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.352 Paracoccus pigment. (a) Identity. (1) The color additive paracoccus pigment consists of the heat-killed, dried cells of a nonpathogenic and nontoxicogenic strain...

  11. 21 CFR 73.352 - Paracoccus pigment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Paracoccus pigment. 73.352 Section 73.352 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.352 Paracoccus pigment. (a) Identity. (1) The color additive paracoccus pigment consists of the heat-killed, dried cells of a nonpathogenic and nontoxicogenic strain...

  12. 21 CFR 73.352 - Paracoccus pigment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Paracoccus pigment. 73.352 Section 73.352 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.352 Paracoccus pigment. (a) Identity. (1) The color additive paracoccus pigment consists of the heat-killed, dried cells of a nonpathogenic and nontoxicogenic strain...

  13. 21 CFR 73.352 - Paracoccus pigment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Paracoccus pigment. 73.352 Section 73.352 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.352 Paracoccus pigment. (a) Identity. (1) The color additive paracoccus pigment consists of the heat-killed, dried cells of a nonpathogenic and nontoxicogenic strain...

  14. 21 CFR 73.352 - Paracoccus pigment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Paracoccus pigment. 73.352 Section 73.352 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.352 Paracoccus pigment. (a) Identity. (1) The color additive paracoccus pigment consists of the heat-killed, dried cells of a nonpathogenic and nontoxicogenic strain...

  15. Raman spectroscopy for the identification of pigments and color measurement in Dugès watercolors.

    PubMed

    Frausto-Reyes, C; Ortiz-Morales, M; Bujdud-Pérez, J M; Magaña-Cota, G E; Mejía-Falcón, R

    2009-12-01

    Spectroscopic and colorimetric analysis of a representative set of Dugès watercolor paintings was performed. These paintings were the result of scientific studies carried out by the zoologist Alfredo Dugès, who recorded the fauna of the Mexican Republic between 1853 and 1910. Micro-Raman spectroscopy, with an excitation wavelength of 830 nm, and colorimetric techniques were employed in order to understand if different colors with the same hue were reproduced using the same pigments. The color coordinates of the measured areas were obtained in the CIEL*a*b* color space. Raman analysis showed that, in some cases, to reproduce colors with the same hue the pigment employed was not the same. Pigments identified in the watercolors were vermilion, carbon-based black, lead white, gamboge and chrome yellow, Prussian and ultramarine blue. Some of these pigments have been used since ancient times, others as Prussian blue, chrome yellow and synthetic ultramarine blue arrived to the market at the beginning of the 18th and 19th centuries, respectively. Furthermore, regarding the white color, instead of left the paper unpainted, lead white was detected in the eye of a bird. The green color was obtained by mixing Prussian blue with chrome yellow. The results of this work show the suitability of using Raman spectroscopy for watercolor pigment analysis and colorimetric techniques to measure the color of small areas (246 microm x 246 microm) that was the case for the lead white pigment. PMID:19875330

  16. Raman spectroscopy for the identification of pigments and color measurement in Dugès watercolors

    NASA Astrophysics Data System (ADS)

    Frausto-Reyes, C.; Ortiz-Morales, M.; Bujdud-Pérez, J. M.; Magaña-Cota, G. E.; Mejía-Falcón, R.

    2009-12-01

    Spectroscopic and colorimetric analysis of a representative set of Dugès watercolor paintings was performed. These paintings were the result of scientific studies carried out by the zoologist Alfredo Dugès, who recorded the fauna of the Mexican Republic between 1853 and 1910. Micro-Raman spectroscopy, with an excitation wavelength of 830 nm, and colorimetric techniques were employed in order to understand if different colors with the same hue were reproduced using the same pigments. The color coordinates of the measured areas were obtained in the CIE L* a* b* color space. Raman analysis showed that, in some cases, to reproduce colors with the same hue the pigment employed was not the same. Pigments identified in the watercolors were vermilion, carbon-based black, lead white, gamboge and chrome yellow, Prussian and ultramarine blue. Some of these pigments have been used since ancient times, others as Prussian blue, chrome yellow and synthetic ultramarine blue arrived to the market at the beginning of the 18th and 19th centuries, respectively. Furthermore, regarding the white color, instead of left the paper unpainted, lead white was detected in the eye of a bird. The green color was obtained by mixing Prussian blue with chrome yellow. The results of this work show the suitability of using Raman spectroscopy for watercolor pigment analysis and colorimetric techniques to measure the color of small areas (246 μm × 246 μm) that was the case for the lead white pigment.

  17. Separation of pigment formulations by high-performance thin-layer chromatography with automated multiple development.

    PubMed

    Stiefel, Constanze; Dietzel, Sylvia; Endress, Marc; Morlock, Gertrud E

    2016-09-01

    Food packaging is designed to provide sufficient protection for the respective filling, legally binding information for the consumers like nutritional facts or filling information, and an attractive appearance to promote the sale. For quality and safety of the package, a regular quality control of the used printing materials is necessary to get consistently good print results, to avoid migration of undesired ink components into the food and to identify potentially faulty ink batches. Analytical approaches, however, have hardly been considered for quality assurance so far due to the lack of robust, suitable methods for the analysis of rarely soluble pigment formulations. Thus, a simple and generic high-performance thin-layer chromatography (HPTLC) method for the separation of different colored pigment formulations was developed on HPTLC plates silica gel 60 by automated multiple development. The gradient system provided a sharp resolution for differently soluble pigment constituents like additives and coating materials. The results of multi-detection allowed a first assignment of the differently detectable bands to particular chemical substance classes (e.g., lipophilic components), enabled the comparison of different commercially available pigment batches and revealed substantial variations in the composition of the batches. Hyphenation of HPTLC with high resolution mass spectrometry and infrared spectroscopy allowed the characterization of single unknown pigment constituents, which may partly be responsible for known quality problems during printing. The newly developed, precise and selective HPTLC method can be used as part of routine quality control for both, incoming pigment batches and monitoring of internal pigment production processes, to secure a consistent pigment composition resulting in consistent ink quality, a faultless print image and safe products. Hyphenation of HPTLC with the A. fischeri bioassay gave first information on the bioactivity or rather

  18. Neurobiology of Monarch Butterfly Migration.

    PubMed

    Reppert, Steven M; Guerra, Patrick A; Merlin, Christine

    2016-01-01

    Studies of the migration of the eastern North American monarch butterfly (Danaus plexippus) have revealed mechanisms behind its navigation. The main orientation mechanism uses a time-compensated sun compass during both the migration south and the remigration north. Daylight cues, such as the sun itself and polarized light, are processed through both eyes and integrated through intricate circuitry in the brain's central complex, the presumed site of the sun compass. Monarch circadian clocks have a distinct molecular mechanism, and those that reside in the antennae provide time compensation. Recent evidence shows that migrants can also use a light-dependent inclination magnetic compass for orientation in the absence of directional daylight cues. The monarch genome has been sequenced, and genetic strategies using nuclease-based technologies have been developed to edit specific genes. The monarch butterfly has emerged as a model system to study the neural, molecular, and genetic basis of long-distance animal migration. PMID:26473314

  19. Deletion of autophagy inducer RB1CC1 results in degeneration of the retinal pigment epithelium

    PubMed Central

    Yao, Jingyu; Jia, Lin; Khan, Naheed; Lin, Chengmao; Mitter, Sayak K; Boulton, Michael E; Dunaief, Joshua L; Klionsky, Daniel J; Guan, Jun-Lin; Thompson, Debra A; Zacks, David N

    2015-01-01

    Autophagy regulates cellular homeostasis and response to environmental stress. Within the retinal pigment epithelium (RPE) of the eye, the level of autophagy can change with both age and disease. The purpose of this study is to determine the relationship between reduced autophagy and age-related degeneration of the RPE. The gene encoding RB1CC1/FIP200 (RB1-inducible coiled-coil 1), a protein essential for induction of autophagy, was selectively knocked out in the RPE by crossing Best1-Cre mice with mice in which the Rb1cc1 gene was flanked with Lox-P sites (Rb1cc1flox/flox). Ex vivo and in vivo analyses, including western blot, immunohistochemistry, transmission electron microscopy, fundus photography, optical coherence tomography, fluorescein angiography, and electroretinography were performed to assess the structure and function of the retina as a function of age. Deletion of Rb1cc1 resulted in multiple autophagy defects within the RPE including decreased conversion of LC3-I to LC3-II, accumulation of autophagy-targeted precursors, and increased numbers of mitochondria. Age-dependent degeneration of the RPE occurred, with formation of atrophic patches, subretinal migration of activated microglial cells, subRPE deposition of inflammatory and oxidatively damaged proteins, subretinal drusenoid deposits, and occasional foci of choroidal neovascularization. There was secondary loss of photoreceptors overlying the degenerated RPE and reduction in the electroretinogram. These observations are consistent with a critical role of autophagy in the maintenance of normal homeostasis in the aging RPE, and indicate that disruption of autophagy leads to retinal phenotypes associated with age-related degeneration. PMID:26075877

  20. Ciliary photoreceptors in the cerebral eyes of a protostome larva

    PubMed Central

    2011-01-01

    Background Eyes in bilaterian metazoans have been described as being composed of either ciliary or rhabdomeric photoreceptors. Phylogenetic distribution, as well as distinct morphologies and characteristic deployment of different photopigments (ciliary vs. rhabdomeric opsins) and transduction pathways argue for the co-existence of both of these two photoreceptor types in the last common bilaterian ancestor. Both receptor types exist throughout the Bilateria, but only vertebrates are thought to use ciliary photoreceptors for directional light detection in cerebral eyes, while all other invertebrate bilaterians studied utilize rhabdomeric photoreceptors for this purpose. In protostomes, ciliary photoreceptors that express c-opsin have been described only from a non-visual deep-brain photoreceptor. Their homology with vertebrate rods and cones of the human eye has been hypothesized to represent a unique functional transition from non-visual to visual roles in the vertebrate lineage. Results To test the hypothesis that protostome cerebral eyes employ exclusively rhabdomeric photoreceptors, we investigated the ultrastructure of the larval eyes in the brachiopod Terebratalia transversa. We show that these pigment-cup eyes consist of a lens cell and a shading pigment cell, both of which are putative photoreceptors, deploying a modified, enlarged cilium for light perception, and have axonal connections to the larval brain. Our investigation of the gene expression patterns of c-opsin, Pax6 and otx in these eyes confirms that the larval eye spots of brachiopods are cerebral eyes that deploy ciliary type photoreceptors for directional light detection. Interestingly, c-opsin is also expressed during early embryogenesis in all potential apical neural cells, becoming restricted to the anterior neuroectoderm, before expression is initiated in the photoreceptor cells of the eyes. Coincident with the expression of c-opsin in the presumptive neuroectoderm, we found that middle

  1. Migration Theories

    NASA Astrophysics Data System (ADS)

    Crida, Aurélien

    2015-08-01

    The great variety of the architectures of the extra-solar planetary systems has revealed the fundamental role played by planetary migration: the interactions between the planets and the gaseous disk in which they form leads to a modification of their orbits. Here, I will review the basic processes and the most recent results in this area.Planets up to ~50 Earth masses are prone to so-called type I migration.I will describe the processes at play, namely the Lindblad and corotation torques, and explain how the total torque depends on the planet mass and the local disk structure. Application to realistic disks shows one or two sweet spot(s) for outward migration of planets roughly between 5 and 30 Earth masses around the snowline ; this is confirmed by dedicated 3D numerical simulations. This has strong consequences on the formation of hot Super-Earths or mini-Neptunes.For smaller mass planets, it has been recently proposed that the heating of the neighboring gas by the luminous planet can lead to a positive torque, hence promoting outward migration. On the other hand, if the planet is not a heat source, a cold finger appears, whose resulting torque is negative. Applications of these two recent results should be discussed.Giant planets open gaps in the proto-planetary disk, and then are supposedly subject to type II migration, following the viscous accretion of the disk. This standard picture has been questioned recently, as gas appears to drift through the gap. Although the gap opening process is well understood in 2D for a planet on a fixed orbit, recent results on 3D simulations or migrating planets make the picture more accurate.Our ever better understanding of planet-disk interactions is of crucial importance as the statistics on extra solar systems keep growing and the results of these interactions are now imaged.

  2. Availability and Utilization of Pigments from Microalgae.

    PubMed

    Begum, Hasina; Yusoff, Fatimah Md; Banerjee, Sanjoy; Khatoon, Helena; Shariff, Mohamed

    2016-10-01

    Microalgae are the major photosynthesizers on earth and produce important pigments that include chlorophyll a, b and c, β-carotene, astaxanthin, xanthophylls, and phycobiliproteins. Presently, synthetic colorants are used in food, cosmetic, nutraceutical, and pharmaceutical industries. However, due to problems associated with the harmful effects of synthetic colorants, exploitation of microalgal pigments as a source of natural colors becomes an attractive option. There are various factors such as nutrient availability, salinity, pH, temperature, light wavelength, and light intensity that affect pigment production in microalgae. This paper reviews the availability and characteristics of microalgal pigments, factors affecting pigment production, and the application of pigments produced from microalgae. The potential of microalgal pigments as a source of natural colors is enormous as an alternative to synthetic coloring agents, which has limited applications due to regulatory practice for health reasons. PMID:25674822

  3. Pigment phenotype and biogeographical ancestry from ancient skeletal remains: inferences from multiplexed autosomal SNP analysis.

    PubMed

    Bouakaze, Caroline; Keyser, Christine; Crubézy, Eric; Montagnon, Daniel; Ludes, Bertrand

    2009-07-01

    In the present study, a multiplexed genotyping assay for ten single nucleotide polymorphisms (SNPs) located within six pigmentation candidate genes was developed on modern biological samples and applied to DNA retrieved from 25 archeological human remains from southern central Siberia dating from the Bronze and Iron Ages. SNP genotyping was successful for the majority of ancient samples and revealed that most probably had typical European pigment features, i.e., blue or green eye color, light hair color and skin type, and were likely of European individual ancestry. To our knowledge, this study reports for the first time the multiplexed typing of autosomal SNPs on aged and degraded DNA. By providing valuable information on pigment traits of an individual and allowing individual biogeographical ancestry estimation, autosomal SNP typing can improve ancient DNA studies and aid human identification in some forensic casework situations when used to complement conventional molecular markers. PMID:19415315

  4. Free-Floating Iris Pigmented Epithelial Cyst in the Anterior Chamber

    PubMed Central

    Rotsos, Tryfon; Bagikos, Georgios; Christou, Spyridon; Symeonidis, Chrysanthos; Papadaki, Thekla; Papaeuthimiou, Ioannis; Miltsakakis, Dimitrios

    2016-01-01

    An unusual case of a free-floating peripheral pigmented cyst in the anterior chamber is presented. A 30-year-old Caucasian male presented reporting a visual defect on his right eye in prone position over the past year. Slit-lamp examination revealed a small pigmented free-floating peripheral iris cyst at the 6 o'clock position in the anterior chamber. Ultrasound biomicroscopy revealed an unfixed epithelial pigmented cyst with an extremely thin wall and no internal reflectivity. Due to the lack of severity of visual disturbance of the patient, no surgical treatment was indicated. The patient is to be followed up annually and advised to return immediately in case of pain or any visual symptoms. Free-floating iris cysts in the anterior chamber are uncommon and remain stable in the majority of cases. Management includes only regular observation until any complications arise. PMID:26904334

  5. Free-Floating Iris Pigmented Epithelial Cyst in the Anterior Chamber.

    PubMed

    Rotsos, Tryfon; Bagikos, Georgios; Christou, Spyridon; Symeonidis, Chrysanthos; Papadaki, Thekla; Papaeuthimiou, Ioannis; Miltsakakis, Dimitrios

    2016-01-01

    An unusual case of a free-floating peripheral pigmented cyst in the anterior chamber is presented. A 30-year-old Caucasian male presented reporting a visual defect on his right eye in prone position over the past year. Slit-lamp examination revealed a small pigmented free-floating peripheral iris cyst at the 6 o'clock position in the anterior chamber. Ultrasound biomicroscopy revealed an unfixed epithelial pigmented cyst with an extremely thin wall and no internal reflectivity. Due to the lack of severity of visual disturbance of the patient, no surgical treatment was indicated. The patient is to be followed up annually and advised to return immediately in case of pain or any visual symptoms. Free-floating iris cysts in the anterior chamber are uncommon and remain stable in the majority of cases. Management includes only regular observation until any complications arise. PMID:26904334

  6. Holographic films from carotenoid pigments

    NASA Astrophysics Data System (ADS)

    Toxqui-López, S.; Lecona-Sánchez, J. F.; Santacruz-Vázquez, C.; Olivares-Pérez, A.; Fuentes-Tapia, I.

    2014-02-01

    Carotenoids pigments presents in pineapple can be more than just natural dyes, which is one of the applications that now at day gives the chemical industry. In this research shown that can be used in implementing of holographic recording Films. Therefore we describe the technique how to obtain this kind of pigments trough spay drying of natural pineapple juice, which are then dissolved with water in a proportion of 0.1g to 1mL. The obtained sample is poured into glass substrates using the gravity method, after a drying of 24 hours in laboratory normal conditions the films are ready. The films are characterized by recording transmission holographic gratings (LSR 445 NL 445 nm) and measuring the diffraction efficiency holographic parameter. This recording material has good diffraction efficiency and environmental stability.

  7. Cutaneous metastatic pigmented breast carcinoma.

    PubMed

    Gaitan-Gaona, Francisco; Said, Mirra C; Valdes-Rodriguez, Rodrigo

    2016-01-01

    A 66-year-old woman presented with a 3 cm black, ulcerated nodule located on the skin of the upper abdomen, just below the breast. The lesion was painful to the touch, but the patient reported no other associated symptoms and was otherwise healthy. A 4-mm punch biopsy of the affected skin was obtained and the histological diagnosis was cutaneous metastatic pigmented breast carcinoma. PMID:27136637

  8. Nanoscience of an ancient pigment.

    PubMed

    Johnson-McDaniel, Darrah; Barrett, Christopher A; Sharafi, Asma; Salguero, Tina T

    2013-02-01

    We describe monolayer nanosheets of calcium copper tetrasilicate, CaCuSi(4)O(10), which have strong near-IR luminescence and are amenable to solution processing methods. The facile exfoliation of bulk CaCuSi(4)O(10) into nanosheets is especially surprising in view of the long history of this material as the colored component of Egyptian blue, a well-known pigment from ancient times. PMID:23215240

  9. Monarch Migration.

    ERIC Educational Resources Information Center

    Williamson, Brad; Taylor, Orley

    1996-01-01

    Describes the Monarch Watch program that tracks the migration of the monarch butterfly. Presents activities that introduce students to research and international collaboration between students and researchers. Familiarizes students with monarchs, stimulates their interest, and helps them generate questions that can lead to good research projects.…

  10. Lasik eye surgery - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000525.htm Lasik eye surgery - discharge To use the sharing features on this page, please enable JavaScript. Lasik eye surgery permanently changes the shape of the cornea ( ...

  11. Diabetic Eye Problems

    MedlinePlus

    ... too high. Over time, this can damage your eyes. The most common problem is diabetic retinopathy. It ... light-sensitive tissue at the back of your eye. You need a healthy retina to see clearly. ...

  12. Fluorescein eye stain

    MedlinePlus

    Abnormal results may point to: Abnormal tear production (dry eye) Blocked tear duct Corneal abrasion (a scratch on ... foreign object in ) Infection Injury or trauma Severe dry eye associated with arthritis (keratoconjunctivitis sicca)

  13. Eye Injuries at Work

    MedlinePlus

    ... Bureau of Labor Statistics, more than 20,000 workplace eye injuries happen each year. Injuries on the job often ... Occupational Safety and Health Administration (OSHA) reports that workplace eye injuries cost an estimated $300 million a year in ...

  14. Eye Injuries (For Parents)

    MedlinePlus

    ... eye nausea or vomiting after an eye injury Think Prevention! Kids who play sports should wear protective goggles or unbreakable glasses as needed. Keep chemicals and other potentially dangerous objects out of the reach of children. Reviewed by: ...

  15. Diabetic Eye Problems

    MedlinePlus

    ... this can damage your eyes. The most common problem is diabetic retinopathy. It is a leading cause ... surgery, with follow-up care. Two other eye problems can happen to people with diabetes. A cataract ...

  16. Eye muscle repair

    MedlinePlus

    ... Your child's eyes should look normal a few weeks after the surgery. ... Surgical Approach to the Rectus Muscles. In: Tasman W, Jaeger EA, ... Hug D, Plummer LS, Stass-Isern M. Disorders of eye movement and ...

  17. Anatomy of the Eye

    MedlinePlus

    ... Examinations, Adults Patient Eye Examinations, Children Refractive Errors Scientists in the Laboratory Visual Acuity Testing Anatomy of the Eye × Warning message Automatic fallback to the cURL connection method kicked in to handle the request. Result code ...

  18. Patient Eye Examinations - Adults

    MedlinePlus

    ... Examinations, Adults Patient Eye Examinations, Children Refractive Errors Scientists in the Laboratory Visual Acuity Testing Patient Eye Examinations, Adults × Warning message Automatic fallback to the cURL connection method kicked in to handle the request. Result code ...

  19. Eye muscle repair

    MedlinePlus

    ... and physical exam before the procedure Orthoptic measurements (eye movement measurements) Always tell your child's doctor or nurse: ... D, Plummer LS, Stass-Isern M. Disorders of eye movement and alignment. In: Kliegman RM, Behrman RE, Jenson ...

  20. Eye Injuries (For Parents)

    MedlinePlus

    ... and comfortable as possible until help arrives. continue Chemical Exposure Many chemicals, even those found around the house, can damage an eye. If your child gets a chemical in the eye and you know what it ...

  1. Diabetes - eye care

    MedlinePlus

    ... dilated eye exam. This is called digital retinal photography. Your eye doctor may ask you to come ... doctor if: You cannot see well in dim light. You have blind spots. You have double vision ( ...

  2. Diabetes and eye disease

    MedlinePlus

    ... the eye that can lead to blindness Macular edema: blurry vision due to fluid leaking into the ... in your retina (neovascularization) or you develop macular edema, treatment is usually needed. Eye surgery is the ...

  3. Eye and orbit ultrasound

    MedlinePlus

    ... the eye (vitreous hemorrhage) Cancer of the retina ( retinoblastoma ), under the retina, or in other parts of ... Cataract removal Melanoma of the eye Retinal detachment Retinoblastoma Ultrasound Update Date 2/23/2015 Updated by: ...

  4. Down Syndrome: Eye Problems

    MedlinePlus

    ... life expectancy. Do children with Down syndrome have eye problems? Individuals with Down syndrome are at increased ... When should children with Down syndrome receive an eye exam? The American Academy of Pediatrics recommends that ...

  5. Toxoplasmosis (and the Eye)

    MedlinePlus

    ... of known infected babies. What happens to the eyes of babies born with congenital toxoplasmosis? The infection ... to further reduce the inflammation. Updated 03/2015 Eye Terms & Conditions Most Common Searches Adult Strabismus Amblyopia ...

  6. Sports and Your Eyes

    MedlinePlus

    ... Glossary The Visual System Your Eyes’ Natural Defenses Eye Health and Safety First Aid Tips Healthy Vision ... More Information Optical Illusions Printables Sports and Your Eyes Gear up! If you play sports, you know ...

  7. Diabetes eye exams

    MedlinePlus

    ... are near. Sunlight can damage your eye. Wear dark glasses or shade your eyes until the effects ... to the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein ...

  8. Anatomy of the Eye

    MedlinePlus

    ... it becomes red or pink. This is called conjunctivitis or “pinkeye”. Lacrimal Gland: The lacrimal gland produces tears that ... Conditions Most Common Searches Adult Strabismus Amblyopia Cataract Conjunctivitis Corneal Abrasions Dilating Eye Drops Lazy eye (defined) ...

  9. Eye - foreign object in

    MedlinePlus

    ... medlineplus.gov/ency/article/002084.htm Eye - foreign object in To use the sharing features on this ... Blinking The eye will often flush out small objects, like eyelashes and sand, through blinking and tearing. ...

  10. The common occurrence of epistasis in the determination of human pigmentation and its impact on DNA-based pigmentation phenotype prediction.

    PubMed

    Pośpiech, Ewelina; Wojas-Pelc, Anna; Walsh, Susan; Liu, Fan; Maeda, Hitoshi; Ishikawa, Takaki; Skowron, Małgorzata; Kayser, Manfred; Branicki, Wojciech

    2014-07-01

    The role of epistatic effects in the determination of complex traits is often underlined but its significance in the prediction of pigmentation phenotypes has not been evaluated so far. The prediction of pigmentation from genetic data can be useful in forensic science to describe the physical appearance of an unknown offender, victim, or missing person who cannot be identified via conventional DNA profiling. Available forensic DNA prediction systems enable the reliable prediction of several eye and hair colour categories. However, there is still space for improvement. Here we verified the association of 38 candidate DNA polymorphisms from 13 genes and explored the extent to which interactions between them may be involved in human pigmentation and their impact on forensic DNA prediction in particular. The model-building set included 718 Polish samples and the model-verification set included 307 independent Polish samples and additional 72 samples from Japan. In total, 29 significant SNP-SNP interactions were found with 5 of them showing an effect on phenotype prediction. For predicting green eye colour, interactions between HERC2 rs12913832 and OCA2 rs1800407 as well as TYRP1 rs1408799 raised the prediction accuracy expressed by AUC from 0.667 to 0.697 and increased the prediction sensitivity by >3%. Interaction between MC1R 'R' variants and VDR rs731236 increased the sensitivity for light skin by >1% and by almost 3% for dark skin colour prediction. Interactions between VDR rs1544410 and TYR rs1042602 as well as between MC1R 'R' variants and HERC2 rs12913832 provided an increase in red/non-red hair prediction accuracy from an AUC of 0.902-0.930. Our results thus underline epistasis as a common phenomenon in human pigmentation genetics and demonstrate that considering SNP-SNP interactions in forensic DNA phenotyping has little impact on eye, hair and skin colour prediction. PMID:24681889

  11. A butterfly eye's view of birds.

    PubMed

    Frentiu, Francesca D; Briscoe, Adriana D

    2008-11-01

    The striking color patterns of butterflies and birds have long interested biologists. But how these animals see color is less well understood. Opsins are the protein components of the visual pigments of the eye. Color vision has evolved in butterflies through opsin gene duplications, through positive selection at individual opsin loci, and by the use of filtering pigments. By contrast, birds have retained the same opsin complement present in early-jawed vertebrates, and their visual system has diversified primarily through tuning of the short-wavelength-sensitive photoreceptors, rather than by opsin duplication or the use of filtering elements. Butterflies and birds have evolved photoreceptors that might use some of the same amino acid sites for generating similar spectral phenotypes across approximately 540 million years of evolution, when rhabdomeric and ciliary-type opsins radiated during the early Cambrian period. Considering the similarities between the two taxa, it is surprising that the eyes of birds are not more diverse. Additional taxonomic sampling of birds may help clarify this mystery. PMID:18937365

  12. Get Your Eyes Tested

    MedlinePlus

    ... over age 40 Have a family history of glaucoma Have diabetes People with diabetes may need eye exams more ... or if you have a family member with diabetes or an eye disease. Eye diseases like glaucoma can lead to vision loss and blindness if ...

  13. Dwarf Eye Disorder

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Johns Hopkins researchers at the Wilmer Eye Institute have discovered what appears to be the first human gene mutation that causes extreme farsightedness. The researchers report that nanophthalmos, Greek for "dwarf eye," is a rare, potentially blinding disorder caused by an alteration in a gene called MFRP that helps control eye growth and…

  14. Impact of Eye Cosmetics on the Eye, Adnexa, and Ocular Surface.

    PubMed

    Ng, Alison; Evans, Katharine; North, Rachel V; Jones, Lyndon; Purslow, Christine

    2016-07-01

    Despite the fact that cosmetic products undergo rigorous testing to ensure they are safe for human use, some users report mild discomfort following their application. The cutaneous changes, such as allergic dermatitis, are well reported, but the ocular changes associated with eye cosmetic use are less so. Some pigmented cosmetic products may accumulate within the lacrimal system and conjunctivae over many years of use, but immediate reports of eye discomfort after application are most common. Changes to the tear film and its stability may occur shortly after application, and contact lens wearers can also be affected by lens spoliation from cosmetic products. Additionally, creams used in the prevention of skin aging are often applied around the eyes, and retinoids present in these formulations can have negative effects on meibomian gland function and may be a contributing factor to dry eye disease. The aim of this review is to summarize current knowledge regarding the impact of cosmetic products on the eye, ocular surface, and tear film. PMID:26398576

  15. Recovery of the human photopic electroretinogram after bleaching exposures: estimation of pigment regeneration kinetics

    PubMed Central

    Mahroo, OAR; Lamb, TD

    2004-01-01

    We used a fibre electrode in the lower conjunctival sac of the human eye to record the a-wave of the photopic electroretinogram elicited in response to dim red flashes, delivered in the presence of a rod-saturating blue background, before and after exposure of the eye to bright white illumination that bleached a significant fraction of cone photopigment. Responses were recorded from two normal subjects whose pupils were maximally dilated. A range of intensities of bleaching light were used, from 500 to 3000 photopic cd m−2, and exposures were made sufficiently long in duration to achieve a steady-state bleach. In addition, responses were also recorded following shorter durations of exposures to the highest intensity (3000 cd m−2); these durations ranged from 5 to 60 s. The amplitude of the a-wave response to dim flashes was reduced following the exposures, with brighter or longer exposures causing greater reduction. The amplitude then recovered within about 4 min to the prebleach level. The amplitudes measured at ca 15 ms after the flash were used to derive the effective intensity of the flashes, thereby quantifying the fraction of photopigment available at the time of delivery of each flash. Recovery from all exposures in both subjects followed a common time course, which could be described well by a model of pigment kinetics based on rate-limited regeneration, where the initial rate of recovery following a total bleach was ca 50% of the total pigment per minute, and the residual pigment level for half the maximal rate was ca 20% of the total pigment. The same parameters, together with a fixed photosensitivity, could account for the steady-state pigment levels seen at each bleaching intensity, and also for the fraction of pigment bleached following exposures of different duration at the highest intensity. The dim-flash ERG thus provides a novel method for assessing pigment regeneration in vivo. Our finding that pigment regeneration follows rate

  16. Spectral organization of the eye of a butterfly, Papilio.

    PubMed

    Arikawa, K

    2003-11-01

    This review outlines our recent studies on the spectral organization of butterfly compound eyes, with emphasis on the Japanese yellow swallowtail butterfly, Papilio xuthus, which is the most extensively studied species. Papilio has color vision when searching for nectar among flowers, and their compound eyes are furnished with six distinct classes of spectral receptors (UV, violet, blue, green, red, broadband). The compound eyes consist of many ommatidia, each containing nine photoreceptor cells. How are the six classes of spectral receptors arranged in the ommatidia? By studying their electrophysiology, histology, and molecular biology, it was found that the Papilio ommatidia can be divided into three types according to the combination of spectral receptors they contain. Different types of ommatidia are distributed randomly over the retina. Histologically, the heterogeneity appeared to be related to red or yellow pigmentation around the rhabdom. A subset of red-pigmented ommatidia contains 3-hydroxyretinol in the distal portion, fluorescing under UV epi-illumination. The red, yellow and fluorescing pigments all play crucial roles in determining the spectral sensitivities of receptors. Spectral heterogeneity and random array of ommatidia have also been found in other lepidopteran species. Similarities and differences between species are also discussed. PMID:14520495

  17. Ion Channels in the Eye: Involvement in Ocular Pathologies.

    PubMed

    Giblin, Jonathan P; Comes, Nuria; Strauss, Olaf; Gasull, Xavier

    2016-01-01

    The eye is the sensory organ of vision. There, the retina transforms photons into electrical signals that are sent to higher brain areas to produce visual sensations. In the light path to the retina, different types of cells and tissues are involved in maintaining the transparency of avascular structures like the cornea or lens, while others, like the retinal pigment epithelium, have a critical role in the maintenance of photoreceptor function by regenerating the visual pigment. Here, we have reviewed the roles of different ion channels expressed in ocular tissues (cornea, conjunctiva and neurons innervating the ocular surface, lens, retina, retinal pigment epithelium, and the inflow and outflow systems of the aqueous humor) that are involved in ocular disease pathophysiologies and those whose deletion or pharmacological modulation leads to specific diseases of the eye. These include pathologies such as retinitis pigmentosa, macular degeneration, achromatopsia, glaucoma, cataracts, dry eye, or keratoconjunctivitis among others. Several disease-associated ion channels are potential targets for pharmacological intervention or other therapeutic approaches, thus highlighting the importance of these channels in ocular physiology and pathophysiology. PMID:27038375

  18. VEGF165b in the developing vasculatures of the fetal human eye

    PubMed Central

    Baba, Takayuki; McLeod, D. Scott; Edwards, Malia M.; Merges, Carol; Sen, Tanusree; Sinha, Debasish; Lutty, Gerard A.

    2016-01-01

    VEGF165b is an anti-angiogenic form of VEGF165 produced by alternative splicing. The localization of pro-angiogenic VEGF165 and anti-angiogenic VEGF165b was investigated during development of the vasculatures in fetal human eyes from 7 to 21 weeks gestation (WG). The fetal vasculature of vitreous, which includes tunica vasculosa lentis (TVL), had moderate VEGF165 immunoreactivity at 7WG and very little VEGF165b. Both forms were elevated at 12WG. VEGF165 then decreased around 17WG when the TVL regresses but VEGF165b remained elevated. In choroid, VEGF165 was present in forming choriocapillaris (CC) and retinal pigment epithelium (RPE) at 7WG while VEGF165b was present in CC and mesenchymal precursors within the choroidal stroma. By 21WG, both forms were elevated in RPE and choroidal blood vessels but VEGF165b was apical and VEGF165 basal in RPE. Diffuse VEGF165 immunoreactivity was prominent in 12WG innermost retina where blood vessels will form while VEGF165b was present in most CXCR4+ progenitors in the inner neuroblastic layer and migrating angioblasts in the putative nerve fiber layer. By 21WG, VEGF165 was present in nerve fibers and VEGF165b in inner Muller cell process. The localization of VEGF165b was distinctly different from VEGF165 both spatially and temporally and it was often associated with nucleus in progenitors. PMID:22275161

  19. Ultrastructure and development of the rhabdomeric eyes in Lineus viridis (Heteronemertea, Nemertea).

    PubMed

    von Döhren, Jörn; Bartolomaeus, Thomas

    2007-01-01

    Nemerteans are undoubtedly members of the Spiralia, although their phylogenetic relationships are still a matter of debate. The apparently acoelomate organization suggests a relationship with the platyhelminths, whereas the blood-vascular system has been interpreted as an equivalent to coelomic cavities of annelids, indicating a close relation between annelids and nemerteans. Like other spiralians, most nemertean species are known to have one or several pairs of rhabdomeric and subepidermally situated eyes when adult. The development of these eyes as well as the mode in which the eyes are multiplied is as yet unknown. This is the first attempt to investigate eye formation in a nemertean. In the heteronemertean Lineus viridis (Müller, 1774) the everse rhabdomeric eyes are located deeply underneath the epidermis and consist of a few pigment cells that form a cup-like structure with interdigitating processes that contain numerous pigment granules. In hatchlings, the optical cavity contains processes of 12 sensory cells, each bearing a single cilium and various microvilli. The perikarya of these cells are located distally from the pigment cup. During further development the number of cells increases. Eye development starts with a small anlage situated underneath the epidermis, irrespective of whether this is the first eye or any additional one. The anlage consists of five unpigmented cells and three dendritic processes, each bearing apical microvilli and a single cilium. There is no evidence for an epidermal origin of the eyes. In L. viridis eye formation resembles that described in platyhelminths in which eyes also develop as cerebral derivatives. Although this result has the potential to influence the discussion on the position of Nemertea, the data have to be interpreted with care, since development of L. viridis is derived within the Nemertea. PMID:17913481

  20. Non-photosynthetic pigments as potential biosignatures

    NASA Astrophysics Data System (ADS)

    Schwieterman, E. W.; Cockell, C. S.; Meadows, V. S.

    2014-03-01

    Photosynthetic organisms on Earth produce potentially detectable surface reflectance biosignatures due in part to the spectral location and strength of pigment absorption. However, life on Earth uses pigments for a multitude of purposes other than photosynthesis, including coping with extreme environments. Macroscopic environments exist on Earth where the surface reflectance is significantly altered by a nonphotosynthetic pigment, such as the case of hypersaline lakes and ponds (Oren et al. 1992). Here we explore the nature and potential detectability of non-photosynthetic pigments in disk-averaged planetary observations using a combination of laboratory measurements and archival reflectance spectra, along with simulated broadband photometry and spectra. The in vivo visible reflectance spectra of a cross section of pigmented microorganisms are presented to illustrate the spectral diversity of biologically produced pigments. Synthetic broadband colors are generated to show a significant spread in color space. A 1D radiative transfer model (Meadows & Crisp 1996; Crisp 1997) is used to approximate the spectra of scenarios where pigmented organisms are widespread on planets with Earth-like atmospheres. Broadband colors are revisited to show that colors due to surface reflectivity are not robust to the addition of scattering and absorption effects from the atmosphere. We consider a èbest case' plausible scenario for the detection of nonphotosynthetic pigments by using the Virtual Planetary Laboratory's 3D spectral Earth model (Robinson et al. 2011) to explore the detectability of the surface biosignature produced by pigmented halophiles that are widespread on an Earth-analog planet.

  1. Susceptibility Loci for Pigmentation and Melanoma in Relation to Parkinson’s disease

    PubMed Central

    Nalls, Michael; Gao, Xiang; Huang, Xuemei; Han, Jiali; Singleton, Andrew B.; Chen, Honglei

    2014-01-01

    Growing evidence suggests that Parkinson’s disease (PD) patients have a lower risk for most types of cancer except for melanoma, which has a modest positive association with PD. Pigmentation genes has been hypothesized to contribute to this association. We therefore examined whether genetic susceptibility loci for pigmentation or melanoma were associated with PD risk in two large independent datasets. In the Parkinson’s Genes and Environment (PAGE) Study, we examined 11 SNPs identified from previous GWAS studies of pigmentation or melanoma in relation to PD among 808 PD cases and 1,623 controls; further, we also examined the colors of hair, eye, or skin, and melanoma in relation to PD. In the International Parkinson’s Disease Genomic Consortium (IPDGC), we examined a broader selection of 360 pigmentation or melanoma GWAS SNPs in relation to PD among 5,333 PD cases and 12,019 controls. All participants were non-Hispanic Whites. As expected, in the PAGE study, most SNPs were associated with one or more pigmentation phenotypes. However, neither these SNPs nor pigmentation phenotypes were associated with PD risk after Bonferroni correction with the exception of rs4911414 at the ASIP gene (P=0.001). A total of 18 PD cases (2.2%) and 26 controls (1.6%) had a diagnosis of melanoma with an odds ratio of 1.3 (95% confidence interval: 0.7-2.4). In the IPDGC analysis, none of the 360 SNPs, including rs4911414, were associated with PD risk after adjusting for multiple comparisons. In conclusion, we did not find significant associations between GWAS SNPs of pigmentation or melanoma and the risk for PD. PMID:24439955

  2. Ethnic and Mouse Strain Differences in Central Corneal Thickness and Association with Pigmentation Phenotype

    PubMed Central

    Dimasi, David P.; Hewitt, Alex W.; Kagame, Kenneth; Ruvama, Sam; Tindyebwa, Ludovica; Llamas, Bastien; Kirk, Kirsty A.; Mitchell, Paul; Burdon, Kathryn P.; Craig, Jamie E.

    2011-01-01

    The cornea is a transparent structure that permits the refraction of light into the eye. Evidence from a range of studies indicates that central corneal thickness (CCT) is strongly genetically determined. Support for a genetic component comes from data showing significant variation in CCT between different human ethnic groups. Interestingly, these studies also appear to show that skin pigmentation may influence CCT. To validate these observations, we undertook the first analysis of CCT in an oculocutaneous albinism (OCA) and Ugandan cohort, populations with distinct skin pigmentation phenotypes. There was a significant difference in the mean CCT of the OCA, Ugandan and Australian-Caucasian cohorts (Ugandan: 517.3±37 µm; Caucasian: 539.7±32.8 µm, OCA: 563.3±37.2 µm; p<0.001). A meta-analysis of 53 studies investigating the CCT of different ethnic groups was then performed and demonstrated that darker skin pigmentation is associated with a thinner CCT (p<0.001). To further verify these observations, we measured CCT in 13 different inbred mouse strains and found a significant difference between the albino and pigmented strains (p = 0.008). Specific mutations within the melanin synthesis pathway were then investigated in mice for an association with CCT. Significant differences between mutant and wild type strains were seen with the nonagouti (p<0.001), myosin VA (p<0.001), tyrosinase (p = 0.025) and tyrosinase related protein (p = 0.001) genes. These findings provide support for our hypothesis that pigmentation is associated with CCT and identifies pigment-related genes as candidates for developmental determination of a non-pigmented structure. PMID:21853026

  3. Pigmented Lesion of Buccal Mucosa

    PubMed Central

    Bajpai, Manas; Kumar, Malay; Kumar, Manish; Agarwal, Deshant

    2014-01-01

    Pigmented lesions are commonly found in the mouth. Such lesions represent a variety of clinical entities, ranging from physiologic changes to manifestation of systemic illness and malignant neoplasm. Diagnosis of such lesions requires a proper case history, extraoral and intraoral examination, and, in some cases, biopsy, aspiration cytology, and laboratory investigations. Here we present a case of purple lesion on the buccal mucosa of a 34-year-old male patient which was provisionally diagnosed as mucocele but on the basis of histopathological picture it was finally diagnosed as angiofibroma, and we also discuss the clinical and histopathological differential diagnosis. PMID:25161669

  4. Melanin pigmented solar absorbing surfaces

    SciTech Connect

    Gallas, J.M.; Eisner, M.

    1980-01-01

    Selectivity enhancement is shown to result for melanin, a black biopolymer pigment, for sufficiently low sample density. The effect is proposed to follow from a consideration of the evanescent waves associated with the total internal reflection phenomenon. A relationship is discussed among powder density, pH and the paramagnetic properties of melanin; this relationship is shown to be consistent with, and offer support to an amino-acid side group proposed earlier as part of the melanin structure. A brief discussion is also presented on the optical properties of melanin and the relative importance of quinhydrone, a change transfer complex believed to exist in the polymeric structure of melanin.

  5. Pigmented lesion of buccal mucosa.

    PubMed

    Bajpai, Manas; Kumar, Malay; Kumar, Manish; Agarwal, Deshant

    2014-01-01

    Pigmented lesions are commonly found in the mouth. Such lesions represent a variety of clinical entities, ranging from physiologic changes to manifestation of systemic illness and malignant neoplasm. Diagnosis of such lesions requires a proper case history, extraoral and intraoral examination, and, in some cases, biopsy, aspiration cytology, and laboratory investigations. Here we present a case of purple lesion on the buccal mucosa of a 34-year-old male patient which was provisionally diagnosed as mucocele but on the basis of histopathological picture it was finally diagnosed as angiofibroma, and we also discuss the clinical and histopathological differential diagnosis. PMID:25161669

  6. Diel Migrations of Microorganisms within a Benthic, Hypersaline Mat Community

    PubMed Central

    Garcia-Pichel, Ferran; Mechling, Margaret; Castenholz, Richard W.

    1994-01-01

    We studied the diel migrations of several species of microorganisms in a hypersaline, layered microbial mat. The migrations were quantified by repeated coring of the mat with glass capillary tubes. The resulting minicores were microscopically analyzed by using bright-field and epifluorescence (visible and infrared) microscopy to determine depths of coherent layers and were later dissected to determine direct microscopic counts of microorganisms. Microelectrode measurements of oxygen concentration, fiber optic microprobe measurements of light penetration within the mat, and incident irradiance measurements accompanied the minicore sampling. In addition, pigment content, photosynthesis and irradiance responses, the capacity for anoxygenic photosynthesis, and gliding speeds were determined for the migrating cyanobacteria. Heavily pigmented Oscillatoria sp. and Spirulina cf. subsalsa migrated downward into the mat during the early morning and remained deep until dusk, when upward migration occurred. The mean depth of the migration (not more than 0.4 to 0.5 mm) was directly correlated with the incident irradiance over the mat surface. We estimated that light intensity at the upper boundary of the migrating cyanobacteria was attenuated to such an extent that photoinhibition was effectively avoided but that intensities which saturated photosynthesis were maintained through most of the daylight hours. Light was a cue of paramount importance in triggering and modulating the migration of the cyanobacteria, even though the migrating phenomenon could not be explained solely in terms of a light response. We failed to detect diel migration patterns for other cyanobacterial species and filamentous anoxyphotobacteria. The sulfide-oxidizing bacterium Beggiatoa sp. migrated as a band that followed low oxygen concentrations within the mat during daylight hours. During the nighttime, part of this population migrated toward the mat surface, but a significant proportion remained deep

  7. Automated Dermoscopy Image Analysis of Pigmented Skin Lesions

    PubMed Central

    Baldi, Alfonso; Quartulli, Marco; Murace, Raffaele; Dragonetti, Emanuele; Manganaro, Mario; Guerra, Oscar; Bizzi, Stefano

    2010-01-01

    Dermoscopy (dermatoscopy, epiluminescence microscopy) is a non-invasive diagnostic technique for the in vivo observation of pigmented skin lesions (PSLs), allowing a better visualization of surface and subsurface structures (from the epidermis to the papillary dermis). This diagnostic tool permits the recognition of morphologic structures not visible by the naked eye, thus opening a new dimension in the analysis of the clinical morphologic features of PSLs. In order to reduce the learning-curve of non-expert clinicians and to mitigate problems inherent in the reliability and reproducibility of the diagnostic criteria used in pattern analysis, several indicative methods based on diagnostic algorithms have been introduced in the last few years. Recently, numerous systems designed to provide computer-aided analysis of digital images obtained by dermoscopy have been reported in the literature. The goal of this article is to review these systems, focusing on the most recent approaches based on content-based image retrieval systems (CBIR). PMID:24281070

  8. Magnetic Nanoparticles as Intraocular Drug Delivery System to Target Retinal Pigmented Epithelium (RPE)

    PubMed Central

    Giannaccini, Martina; Giannini, Marianna; Calatayud, M. Pilar; Goya, Gerardo F.; Cuschieri, Alfred; Dente, Luciana; Raffa, Vittoria

    2014-01-01

    One of the most challenging efforts in drug delivery is the targeting of the eye. The eye structure and barriers render this organ poorly permeable to drugs. Quite recently the entrance of nanoscience in ocular drug delivery has improved the penetration and half-life of drugs, especially in the anterior eye chamber, while targeting the posterior chamber is still an open issue. The retina and the retinal pigment epithelium/choroid tissues, located in the posterior eye chamber, are responsible for the majority of blindness both in childhood and adulthood. In the present study, we used magnetic nanoparticles (MNPs) as a nanotool for ocular drug delivery that is capable of specific localization in the retinal pigmented epithelium (RPE) layer. We demonstrate that, following intraocular injection in Xenopus embryos, MNPs localize specifically in RPE where they are retained for several days. The specificity of the localization did not depend on particle size and surface properties of the MNPs used in this work. Moreover, through similar experiments in zebrafish, we demonstrated that the targeting of RPE by the nanoparticles is not specific for the Xenopus species. PMID:24451140

  9. Eye color: A potential indicator of alcohol dependence risk in European Americans.

    PubMed

    Sulovari, Arvis; Kranzler, Henry R; Farrer, Lindsay A; Gelernter, Joel; Li, Dawei

    2015-07-01

    In archival samples of European-ancestry subjects, light-eyed individuals have been found to consume more alcohol than dark-eyed individuals. No published population-based studies have directly tested the association between alcohol dependence (AD) and eye color. We hypothesized that light-eyed individuals have a higher prevalence of AD than dark-eyed individuals. A mixture model was used to select a homogeneous sample of 1,263 European-Americans and control for population stratification. After quality control, we conducted an association study using logistic regression, adjusting for confounders (age, sex, and genetic ancestry). We found evidence of association between AD and blue eye color (P = 0.0005 and odds ratio = 1.83 (1.31-2.57)), supporting light eye color as a risk factor relative to brown eye color. Network-based analyses revealed a statistically significant (P = 0.02) number of genetic interactions between eye color genes and AD-associated genes. We found evidence of linkage disequilibrium between an AD-associated GABA receptor gene cluster, GABRB3/GABRG3, and eye color genes, OCA2/HERC2, as well as between AD-associated GRM5 and pigmentation-associated TYR. Our population-phenotype, network, and linkage disequilibrium analyses support association between blue eye color and AD. Although we controlled for stratification we cannot exclude underlying occult stratification as a contributor to this observation. Although replication is needed, our findings suggest that eye pigmentation information may be useful in research on AD. Further characterization of this association may unravel new AD etiological factors. © 2015 Wiley Periodicals, Inc. PMID:25921801

  10. Prevention of Eye Injuries

    PubMed Central

    Pashby, Tom

    1981-01-01

    In Canada 30,000 people are registered as blind; in one third of these, blindness might have been avoided. Prevention is the key to reducing the number of eye injuries and blind eyes. The role of the family physician in early identification of treatable conditions and in the education of patients is discussed, but responsibility for prevention belongs to all physicians. The success of prevention is seen in the great reduction in eye injuries in industry and sports since eye protectors have been commonly used. However, many dangers to the eyes are either not recognized or are not taken seriously enough. This paper discusses some of the common causes of serious eye injuries in the home, in sports and in industry. Imagesp464-aFig. 1Fig. 2Fig. 3Fig. 4 PMID:21289691

  11. The eyes of Tullimonstrum reveal a vertebrate affinity.

    PubMed

    Clements, Thomas; Dolocan, Andrei; Martin, Peter; Purnell, Mark A; Vinther, Jakob; Gabbott, Sarah E

    2016-04-28

    Tullimonstrum gregarium is an iconic soft-bodied fossil from the Carboniferous Mazon Creek Lagerstätte (Illinois, USA). Despite a large number of specimens and distinct anatomy, various analyses over the past five decades have failed to determine the phylogenetic affinities of the 'Tully monster', and although it has been allied to such disparate phyla as the Mollusca, Annelida or Chordata, it remains enigmatic. The nature and phylogenetic affinities of Tullimonstrum have defied confident systematic placement because none of its preserved anatomy provides unequivocal evidence of homology, without which comparative analysis fails. Here we show that the eyes of Tullimonstrum possess ultrastructural details indicating homology with vertebrate eyes. Anatomical analysis using scanning electron microscopy reveals that the eyes of Tullimonstrum preserve a retina defined by a thick sheet comprising distinct layers of spheroidal and cylindrical melanosomes. Time-of-flight secondary ion mass spectrometry and multivariate statistics provide further evidence that these microbodies are melanosomes. A range of animals have melanin in their eyes, but the possession of melanosomes of two distinct morphologies arranged in layers, forming retinal pigment epithelium, is a synapomorphy of vertebrates. Our analysis indicates that in addition to evidence of colour patterning, ecology and thermoregulation, fossil melanosomes can also carry a phylogenetic signal. Identification in Tullimonstrum of spheroidal and cylindrical melanosomes forming the remains of retinal pigment epithelium indicates that it is a vertebrate; considering its body parts in this new light suggests it was an anatomically unusual member of total group Vertebrata. PMID:27074512

  12. Ultraviolet pigments in birds evolved from violet pigments by a single amino acid change

    PubMed Central

    Yokoyama, Shozo; Radlwimmer, F. Bernhard; Blow, Nathan S.

    2000-01-01

    UV vision has profound effects on the evolution of organisms by affecting such behaviors as mating preference and foraging strategies. Despite its importance, the molecular basis of UV vision is not known. Here, we have transformed the zebra finch UV pigment into a violet pigment by incorporating one amino acid change, C84S. By incorporating the reverse mutations, we have also constructed UV pigments from the orthologous violet pigments of the pigeon and chicken. These results and comparative amino acid sequence analyses of the pigments in vertebrates demonstrate that many avian species have achieved their UV vision by S84C. PMID:10861005

  13. [Pigmented lesions of the oral cavity].

    PubMed

    Brocheriou, C; Kuffer, R; Verola, O

    1985-01-01

    Pigmented lesions of the oral cavity are of multiple origin. They can be subdivided as follows: non tumoral pigmentations, non melanin pigmented tumors or tumor-like lesions, benign melanin pigmented tumors and malignant melanomas. Among non tumoral pigmented lesions, some of them show melanin deposits: they can be associated with a systemic disease (Peutz Jeghers syndrome, Addison's disease) or have a medicamentous origin, or belong to a lichen migricans. Non tumoral and non melanin pigmentations are principally due to a heavy metal accumulation or an accidental tatoo arising after tooth treatment. Peripheral giant cell granuloma, so-called giant cell epulis is the major non pigmented non melanin pseudotumoral lesion; pigmentation is due to hemosiderin deposits. In the oral cavity nevi are principally of the intramucosal type. Blue nevus, the second type in frequency, is usually located on the hard palate. Primary malignant melanomas are rare in the oral cavity, but it is--because its very bad prognosis--the most important lesion. In order to improve the survival it is necessary to do the diagnosis as early as possible. PMID:3833244

  14. Endocrine factors as effectors of integumental pigmentation.

    PubMed

    Abdel-Malek, Z A

    1988-04-01

    Normal and malignant pigment cells are known targets for many hormones. Besides alpha-melanocyte-stimulating hormone and the steroidal hormones estrogen, testosterone, and glucocorticoids, factors produced by other epidermal cells can affect melanization and proliferation of pigment cells. Among those factors are the prostaglandins, vitamin D3, ETAF, and interleukin-1. PMID:3132340

  15. Thin Layer Chromatography (TLC) of Chlorophyll Pigments.

    ERIC Educational Resources Information Center

    Foote, Jerry

    1984-01-01

    Background information, list of materials needed, procedures used, and discussion of typical results are provided for an experiment on the thin layer chromatography of chlorophyll pigments. The experiment works well in high school, since the chemicals used are the same as those used in paper chromatography of plant pigments. (JN)

  16. ORGANIC DYES AND PIGMENTS DATA BASE

    EPA Science Inventory

    The objective of this research program was to compile a data base covering all the commercially significant dyes and pigments produced or imported in the United States. The Organic Dyes and Pigments Data Base (ODPDB) contains the following data elements: chemical-related data (co...

  17. The bioefficacy of microemulsified natural pigments in egg yolk pigmentation.

    PubMed

    Chow, P Y; Gue, S Z; Leow, S K; Goh, L B

    2014-01-01

    1. This study was designed to test the hypothesis that microemulsified carotenoid products show improved bioavailability over corresponding regular preparations, leading to greater yolk pigmentation at lower dosages. 2. The first trial was conducted using a maize-soya bean basal diet supplemented with either 0.25, 0.5, 0.75, 1.0 and 1.25 g/kg of microemulsified Red or non-microemulsified Red. The second trial involved feeding microemulsified Yellow or non-microemulsified Yellow using a similar dosage range. The layers were divided into 4 replicates of 8 layers each (32 layers per treatment). The 8 cages of layers were fed from a single feed trough. Feed and water were provided ad libitum throughout the trial. Each week, the eggs were collected. The whole liquid egg colour was determined by means of a commercially available yolk colour fan. Where required, HPLC-(high-performance liquid chromatography) based analysis of trans-capsanthin or trans-lutein equivalents using the Association of Analytical Communities method was carried out. Data were statistically analysed by one-way ANOVA method using Statgraphics. 3. Results showed that the colour and carotenoid content of the egg yolk increased with increasing amount of carotenoids in the diet. The colour of egg yolks from layers fed similar concentrations of microemulsified versus the regular preparation was significantly different. At the commercial recommended dose of one g/kg regular Yellow or Red product, the microemulsified pigmenter is able to provide the equivalent yolk colour at a 20-30% lower dose. 4. In conclusion, the trial results supported the hypothesis that a desired yolk colour score is achievable at a significantly lower inclusion rate when carotenoid molecules are emulsified using the microemulsion nanotechnology. PMID:24783946

  18. Single nucleotide polymorphisms in the MATP gene are associated with normal human pigmentation variation.

    PubMed

    Graf, Justin; Hodgson, Richard; van Daal, Angela

    2005-03-01

    Human physical pigmentation is determined by the type and amount of melanin and the process of pigmentation production probably involves more than 100 genes. A failure to synthesize melanin results in oculocutaneous albinism (OCA). A recently identified form of OCA results from mutations in the Membrane Associated Transporter Protein (MATP) gene. The role of MATP in human pigmentation is not clear. We investigated the role of two nonpathogenic nonsynonymous single nucleotide polymorphisms (SNPs) in the MATP gene to determine if they are associated with normal human skin, hair, and eye color variation. A total of 608 individuals from four different population groups (456 Caucasians, 31 Asians, 70 African-Americans, and 51 Australian Aborigines) were genotyped for c.814G>A (p.Glu272Lys) and c.1122C>G (p.Phe374Leu). Results indicate that the allele frequencies of both polymorphisms are significantly different between population groups. The two alleles, 374Leu and 272Lys, are significantly associated with dark hair, skin, and eye color in Caucasians. The odds ratios (ORs) of the LeuLeu genotype for black hair and olive skin are 25.63 and 28.65, respectively, and for the LysLys genotype are 43.23 and 8.27, respectively. The OR for eye color is lower at 3.48 for the LeuLeu and 6.57 for LysLys genotypes. This is the first report of this highly significant association of MATP polymorphisms with normal human pigmentation variation. PMID:15714523

  19. Characterization of visual pigments, oil droplets, lens and cornea in the whooping crane Grus americana

    PubMed Central

    Porter, Megan L.; Kingston, Alexandra C. N.; McCready, Robert; Cameron, Evan G.; Hofmann, Christopher M.; Suarez, Lauren; Olsen, Glenn H.; Cronin, Thomas W.; Robinson, Phyllis R.

    2014-01-01

    Vision has been investigated in many species of birds, but few studies have considered the visual systems of large birds and the particular implications of large eyes and long-life spans on visual system capabilities. To address these issues we investigated the visual system of the whooping crane Grus americana (Gruiformes, Gruidae), which is one of only two North American crane species. It is a large, long-lived bird in which UV sensitivity might be reduced by chromatic aberration and entrance of UV radiation into the eye could be detrimental to retinal tissues. To investigate the whooping crane visual system we used microspectrophotometry to determine the absorbance spectra of retinal oil droplets and to investigate whether the ocular media (i.e. the lens and cornea) absorb UV radiation. In vitro expression and reconstitution was used to determine the absorbance spectra of rod and cone visual pigments. The rod visual pigments had wavelengths of peak absorbance (λmax) at 500 nm, whereas the cone visual pigment λmax values were determined to be 404 nm (SWS1), 450 nm (SWS2), 499 nm (RH2) and 561 nm (LWS), similar to other characterized bird visual pigment absorbance values. The oil droplet cut-off wavelength (λcut) values similarly fell within ranges recorded in other avian species: 576 nm (R-type), 522 nm (Y-type), 506 nm (P-type) and 448 nm (C-type). We confirm that G. americana has a violet-sensitive visual system; however, as a consequence of the λmax of the SWS1 visual pigment (404 nm), it might also have some UV sensitivity. PMID:25267845

  20. Visual pigments, oil droplets, lens, and cornea characterization in the whooping crane (Grus americana)

    USGS Publications Warehouse

    Porter, Megan L.; Kingston, Alexandra C. N.; McCready, Robert; Cameron, Evan G.; Hofmann, Christopher M.; Suarez, Lauren; Olsen, Glenn H.; Cronin, Thomas W.; Robinson, Phyllis R.

    2014-01-01

    Vision has been investigated in many species of birds, but few studies have considered the visual systems of large birds and the particular implications of large eyes and long-life spans on visual system capabilities. To address these issues we investigated the visual system of the whooping crane, Grus americana (Gruiformes: Gruidae). G. americana (an endangered species) is one of only two North American crane species and represents a large, long-lived bird where ultraviolet sensitivity may be degraded by chromatic aberrations and entrance of ultraviolet light into the eye could be detrimental to retinal tissues. To investigate the whooping crane visual system we used microspectrophotometry to determine the absorbance spectra of retinal oil droplets and to investigate if the ocular media (i.e., the lens and cornea) absorbs UV light. In vitro expression and reconstitution was used to determine the absorbance spectra of rod and cone visual pigments. The rod visual pigments had wavelengths of peak absorbance (λmax) at 500 nm, while the cone visual pigments λmax values were determined to be 404 nm (SWS1), 450 nm (SWS2), 499 nm (RH2), and 561 nm (LWS), similar to other characterized bird visual pigment absorbance values. The oil droplet cutoff wavelength (λcut) values similarly fell within ranges recorded from other avian species: 576 nm (R-type), 522 nm (Y-type), 506 nm (P-type), and 448 nm (C-type). We confirm that G. americana has a violet-sensitive visual system, although based on the λmax of the SWS1 visual pigment (404 nm) may also have some ability for UV sensitivity.

  1. Stem cell treatment of degenerative eye disease☆

    PubMed Central

    Mead, Ben; Berry, Martin; Logan, Ann; Scott, Robert A.H.; Leadbeater, Wendy; Scheven, Ben A.

    2015-01-01

    Stem cell therapies are being explored extensively as treatments for degenerative eye disease, either for replacing lost neurons, restoring neural circuits or, based on more recent evidence, as paracrine-mediated therapies in which stem cell-derived trophic factors protect compromised endogenous retinal neurons from death and induce the growth of new connections. Retinal progenitor phenotypes induced from embryonic stem cells/induced pluripotent stem cells (ESCs/iPSCs) and endogenous retinal stem cells may replace lost photoreceptors and retinal pigment epithelial (RPE) cells and restore vision in the diseased eye, whereas treatment of injured retinal ganglion cells (RGCs) has so far been reliant on mesenchymal stem cells (MSC). Here, we review the properties of non-retinal-derived adult stem cells, in particular neural stem cells (NSCs), MSC derived from bone marrow (BMSC), adipose tissues (ADSC) and dental pulp (DPSC), together with ESC/iPSC and discuss and compare their potential advantages as therapies designed to provide trophic support, repair and replacement of retinal neurons, RPE and glia in degenerative retinal diseases. We conclude that ESCs/iPSCs have the potential to replace lost retinal cells, whereas MSC may be a useful source of paracrine factors that protect RGC and stimulate regeneration of their axons in the optic nerve in degenerate eye disease. NSC may have potential as both a source of replacement cells and also as mediators of paracrine treatment. PMID:25752437

  2. Microwave cyclodestruction: evaluation on human eyes.

    PubMed Central

    Finger, P T; Perry, H D; Shakin, J L; Bisciotti, D R; Nattis, R J

    1995-01-01

    AIMS--The study was set up to evaluate the effect of microwave cyclodestruction on human eyes. METHODS--Two human eyes were studied. For treatment a horn shaped 5.8 GHz microwave applicator and fibre optic thermometry were used. Just before enucleation, the rectangular (2 x 3 mm) microwave aperture was placed onto the conjunctiva at a position 1-2 mm posterior to the corneal scleral limbus. Each of three to four treatment spots was targeted to receive a thermal dose of 54 degrees C for 1 minute. Clinical, gross, and histopathological evaluations were performed. RESULTS--Clinical evaluations of the treatment sites (immediately after microwave application) revealed no evidence of conjunctival or scleral damage. Trace fluorescein 2% uptake was noted within the targeted zones. The first eye was sectioned along the equatorial axis. Examination of the ciliary body and pars plana revealed whitening of the ciliary processes and depigmentation. Histopathological evaluations revealed ciliary epithelial necrosis with pigment dispersion. The vascularity of the ciliary processes showed focal disruption and haemorrhage. The underlying ciliary muscle and sclera appeared to be unaffected. No other findings could be attributed to microwave cyclodestruction. CONCLUSION--The results of this phase I toxicity study suggest that microwave heating can be used to damage preferentially the epithelial layers of the human ciliary body. Images PMID:7662635

  3. Relative permeability of retina and retinal pigment epithelium to the diffusion of tritiated water from vitreous to choroid

    SciTech Connect

    Orr, G.; Goodnight, R.; Lean, J.S.

    1986-11-01

    The movement of intravitreally injected tritiated water from the vitreous to the choroid was accelerated by the removal of intervening retina. Both rate of transfer and peak choroidal levels of the tracer were increased, but the proportion of the intravitreal dose recovered was unaltered. In contrast, the movement of tritiated water after diffuse damage to the retinal pigment epithelium by sodium iodate was similar to that of control eyes. The main resistance to the diffusion of this tracer from the vitreous to the choroid is the retina. The differential permeability of the retina and the retinal pigment epithelium may have a role in normal retinal adhesion.

  4. Developing fungal pigments for "painting" vascular plants.

    PubMed

    Robinson, Sara C

    2012-02-01

    The use of fungal pigments as color additives to wood as a method to increase forest revenue is a relatively new, but quickly developing field. Sugar maple (Acer saccharum) is currently the primary utilized hardwood for spalting and appears to be the best suited North American hardwood for such purposes. The combination of Trametes versicolor and Bjerkandera adusta has been identified in several instances as a strong fungal pairing for zone line production; however, Xylaria polymorpha is capable of creating zone lines without the antagonism of a secondary fungus. Few fungal pigments have been developed for reliable use; Scytalidium cuboideum is capable of producing a penetrating pink/red stain, as well as a blue pigment after extended incubation, and Chlorociboria sp. produces a blue/green pigment if grown on aspen (Populus tremuloides). Several opportunities exist for stimulation of fungal pigments including the use of copper sulfate and changes in wood pH. PMID:22237673

  5. Bilateral pigmented villonodular synovitis of the knee

    PubMed Central

    Shah, Samir H.; Porrino, Jack A.; Green, John R.; Chew, Felix S.

    2015-01-01

    Pigmented villonodular synovitis is a disorder resulting in a villous, nodular, or villonodular proliferation of the synovium, with pigmentation related to the presence of hemosiderin. These lesions are almost exclusively benign with rare reports of malignancy. Pigmented villonodular synovitis can occur in a variety of joints and at any age but most often occurs within the knee in the young adult. Pigmented villonodular synovitis is a rare disease entity, and bilateral synchronous or metachronous involvement of a joint is even more uncommon, with few reports previously described in the literature. We present a case of pigmented villonodular synovitis involving both the right and left knee in the same patient, with radiographic imaging, magnetic resonance imaging, photograph and video intraoperative imaging, and pathologic correlation. PMID:26649121

  6. Prediction of eye color from genetic data using Bayesian approach.

    PubMed

    Pośpiech, Ewelina; Draus-Barini, Jolanta; Kupiec, Tomasz; Wojas-Pelc, Anna; Branicki, Wojciech

    2012-07-01

    Prediction of visible traits from genetic data in certain forensic cases may provide important information that can speed up the process of investigation. Research that has been conducted on the genetics of pigmentation has revealed polymorphisms that explain a significant proportion of the variation observed in human iris color. Here, on the basis of genetic data for the six most relevant eye color predictors, two alternative Bayesian network model variants were developed and evaluated for their accuracy in prediction of eye color. The first model assumed eye color to be categorized into blue, brown, green, and hazel, while the second variant assumed a simplified classification with two states: light and dark. It was found that particularly high accuracy was obtained for the second model, and this proved that reliable differentiation between light and dark irises is possible based on analysis of six single nucleotide polymorphisms and a Bayesian procedure of evidence interpretation. PMID:22372960

  7. Fundus oculi pigmentation studies simulating the fs-LASIK process Fundus oculi pigmentation studies simulating the fs-LASIK process

    NASA Astrophysics Data System (ADS)

    Sander, M.; Minet, O.; Zabarylo, U.; Müller, M.; Tetz, M. R.

    2012-06-01

    The femtosecond-laser in situ keratomileusis (fs-LASIK) technique has successfully entered the refractive surgery market to correct ametropia by cutting transparent corneal tissue with ultra-short laser pulses based on photodisruption. The laser pulses in the near infrared range (NIR) generate a laser-induced breakdown (LIOB) in the cornea. By propagating through the eye, a certain amount of the pulse is deposited in the cornea and the remaining energy interacts with the strong absorbing tissue behind. Due to the absorption by the retinal pigment epithelium and the transfer of the thermal energy to surrounding tissue, the transmitted energy can induce damage to the retina. The aim of this project was to find out the threshold influences concerning the tissue and the correlation between the results of the macroscopical appraisal and the fundus oculi pigmentation by simulating the fs-LASIK procedure with two various laser systems in the continuous wave (CW) and fs-regime. Therefore ex-vivo determinations were carried out macroscopically and histopathologically on porcine tissue.

  8. Towards a better understanding of human eye disease: insights from the zebrafish, Danio rerio

    PubMed Central

    Bibliowicz, Jonathan; Tittle, Rachel K.; Gross, Jeffrey M.

    2011-01-01

    Visual impairment and blindness is widespread across the human population, and the development of therapies for ocular pathologies is of high priority. The zebrafish represents a valuable model organism for studying human ocular disease; it is utilized in eye research to understand underlying developmental processes, to identify potential causative genes for human disorders, and to develop therapies. Zebrafish eyes are similar in morphology, physiology, gene expression and function to human eyes. Furthermore, zebrafish are highly amenable to laboratory research. This review outlines the use of zebrafish as a model for human ocular diseases such as colobomas, glaucoma, cataracts, photoreceptor degeneration, as well as dystrophies of the cornea and retinal pigmented epithelium. PMID:21377629

  9. Changes in spectral properties and composition of lipofuscin fluorophores from human-retinal-pigment epithelium with age and pathology.

    PubMed

    Feldman, Tatiana B; Yakovleva, Marina A; Arbukhanova, Patimat M; Borzenok, Sergey A; Kononikhin, Alexey S; Popov, Igor A; Nikolaev, Evgeny N; Ostrovsky, Mikhail A

    2015-02-01

    Fundus autofluorescence mostly originates from bisretinoid fluorophores in lipofuscin granules, which accumulate in retinal-pigment-epithelium cells with age. The dynamics of accumulation, photo-oxidation, and photodegradation of bisretinoids during aging or in the presence of pathology have been insufficiently investigated. Changes in spectral properties and composition of human lipofuscin-granule fluorophores with age and pathology have now been investigated by a high-performance liquid chromatography method using spectrophotometric and fluorescent detectors connected in series. It was found that: (i) N-retinylidene-N-retinylethanolamine (A2E) fluorescence intensity is not predominant in the chloroform extract of human-cadaver-eye retinal pigment epithelium studied; bisretinoid photo-oxidation and photodegradation products have much higher fluorescent properties; (ii) the relative emission maximum in the fluorescence spectrum of suspended retinal-pigment-epithelium cells obtained from an individual human-cadaver eye without pathology is irrespective of donor age and falls within the range 575 ± 15 nm; in two cadaver eyes with signs of age-related macular degeneration, emission maxima were shifted by 23-36 nm towards the shortwave region; and (iii) the ratio of bisretinoid photo-oxidation and photodegradation products to unoxidized bisretinoids in the chloroform extract of cadaver-eye retinal pigment epithelium increases with donor age, from 0.69 ± 0.03 to 1.32 ± 0.04. The differences in fluorescence properties between chloroform extracts obtained from cadaver eyes with and without signs of age-related macular degeneration could be used to increase the potential of fundus autofluorescence imaging as a noninvasive diagnostic method. PMID:25471291

  10. Structure of plant bile pigments

    SciTech Connect

    Schoenleber, R.W.

    1983-12-01

    Selective peptide cleavage has provided a general procedure for the study of the structure, including stereochemistry, of plant bile pigments. The information derived from the synthesis and spectral analysis of a series of 2,3-dihydrodioxobilins allows the determination of the trans relative stereochemistry for ring A of the ..beta../sub 1/-phycocyanobilin from C-phycocyanin as well as for ring A of phytochrome. A complete structure proof of the five phycoerythrobilins attached to the ..cap alpha.. and ..beta.. subunits of B-phycoerythrin is described. One of these tetrapyrroles is doubly-peptide linked to a single peptide chain through two thioethers at the C-3' and C-18' positions. The four remaining phycoerythrobilins are singly-linked to the protein through thioethers at the C-3' position and all possess the probable stereochemistry C-2(R), C-3(R), C-3'(R), and C-16(R).

  11. Videos from the National Eye Institute: Eye Diseases

    MedlinePlus

    ... this page please turn Javascript on. Feature: Vision Videos from the National Eye Institute: Eye Diseases Past ... the early detection of eye disease. Share these videos with friends, family and colleagues. www.nei.nih. ...

  12. Photorefraction of the Eye

    ERIC Educational Resources Information Center

    Colicchia, Giuseppe; Wiesner, Hartmut; Zollman, Dean

    2015-01-01

    Photorefraction is a method to easily estimate the refractive state of the eye. The principle of photorefraction involves projecting light into the eye during flash photography and then examining the paths of light that emerge from the pupil after scattering on the back portion of the interior of the eyeball (fundus). We will explain the optical…

  13. Eye tissues study

    NASA Astrophysics Data System (ADS)

    Tuchin, Valery V.; Bashkatov, Alexey N.; Maksimova, Irina L.; Sinichkin, Yurii P.; Simonenko, Georgy V.; Genina, Elina A.; Lakodina, Nina A.

    2001-08-01

    Theoretical and in vitro and in vivo experimental study of spectral and polarization characteristics of the human and rabbit eye tissues are presented. The possibility of control of optical properties of eye cornea, lens and sclera is discussed and realized experimentally for glucose solution as the refractive index matching factor.

  14. Preventing Eye Injuries

    MedlinePlus

    ... Eye Injuries Reviewed by: Brenda Pagan-Duran MD Mar. 01, 2016 Protecting your eyes from injury is one of the most basic things you can do to keep your vision healthy throughout your life. You may be somewhat aware of the possible ...

  15. Lasik eye surgery - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100206.htm Lasik eye surgery - series To use the sharing features ... A.M. Editorial team. Related MedlinePlus Health Topics Laser Eye Surgery A.D.A.M., Inc. is accredited by ...

  16. Diabetes and eye disease

    MedlinePlus

    ... the back of the inner eye. It changes light and images that enter the eye into nerve signals, which are sent to the brain. Diabetic retinopathy is a main cause of decreased vision or blindness in Americans 20 to 74 years old. People with type 1 or type 2 ...

  17. Fluorescein eye stain

    MedlinePlus

    ... eye. The health care provider then shines a blue light at your eye. Any problems on the surface of the cornea will be stained by the dye and appear green under the blue light. The provider can determine the location and ...

  18. Understanding pink eye

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pink eye (PE) is a physiological tuber disorder that can result in serious processing complications and storage losses. The earliest external symptoms consist of an ephemeral pinkish discoloration around tuber eyes, predominately at the bud end of the tuber. These pinkish areas can then develop into...

  19. An Eye for Learning.

    ERIC Educational Resources Information Center

    Ostwald, Thomas

    1995-01-01

    Presents a hands-on activity as an excellent starting point for investigations related to the eye. Involves making a simple model of the vertebrate eye to illustrate the formation of an upside-down image on the retina by the lens. Links to investigations in numerous science disciplines including astronomy, genetics, biology, earth science, and…

  20. Smoking and Eye Health

    MedlinePlus

    ... Eye Health Apr. 14, 2014 Avoiding smoking and second hand smoke — or quitting if you are a smoker — are ... influence your eyes’ health. And tobacco smoke, including second-hand smoke, is an irritant that worsens dry eye , a ...

  1. Blue eyes in lemurs and humans: same phenotype, different genetic mechanism.

    PubMed

    Bradley, Brenda J; Pedersen, Anja; Mundy, Nicholas I

    2009-06-01

    Almost all mammals have brown or darkly-pigmented eyes (irises), but among primates, there are some prominent blue-eyed exceptions. The blue eyes of some humans and lemurs are a striking example of convergent evolution of a rare phenotype on distant branches of the primate tree. Recent work on humans indicates that blue eye color is associated with, and likely caused by, a single nucleotide polymorphism (rs12913832) in an intron of the gene HERC2, which likely regulates expression of the neighboring pigmentation gene OCA2. This raises the immediate question of whether blue eyes in lemurs might have a similar genetic basis. We addressed this by sequencing the homologous genetic region in the blue-eyed black lemur (Eulemur macaco flavifrons; N = 4) and the closely-related black lemur (Eulemur macaco macaco; N = 4), which has brown eyes. We then compared a 166-bp segment corresponding to and flanking the human eye-color-associated region in these lemurs, as well as other primates (human, chimpanzee, orangutan, macaque, ring-tailed lemur, mouse lemur). Aligned sequences indicated that this region is strongly conserved in both Eulemur macaco subspecies as well as the other primates (except blue-eyed humans). Therefore, it is unlikely that this regulatory segment plays a major role in eye color differences among lemurs as it does in humans. Although convergent phenotypes can sometimes come about via the same or similar genetic changes occurring independently, this does not seem to be the case here, as we have shown that the genetic basis of blue eyes in lemurs differs from that of humans. PMID:19278018

  2. Surgical Management of Iatrogenic Pigment Dispersion Glaucoma

    PubMed Central

    Mierlo, Camille Van; Pinto, Luis Abegão

    2015-01-01

    ABSTRACT Introduction: Iatrogenic pigment dispersion syndrome generally originates from a repetitive, mechanical trauma to the pigmented posterior epithelium of the iris. This trauma can arise after intraocular surgery, most commonly due to an abnormal contact between the intraocular lens (IOL) and the iris. Whether surgical removal of this primary insult can lead to a successful intraocular pressure (IOP) control remains unclear. Methods: Case-series. Patients with IOP elevation and clinical signs of pigment dispersion were screened for a diagnosis of iatrogenic IOL-related pigment dispersion. Results: Three patients in which the IOL or the IOL-bag complex caused a pigment dispersion through a repetitive iris chafing were selected. In two cases, replacement of a sulcus-based single-piece IOL (patient 1) or a sub-luxated in-the-bag IOL (patient 2) by an anterior-chamber (AC) iris-fixed IOL led to a sustained decrease in IOP. In the third case, extensive iris atrophy and poor anatomical AC parameters for IOL implantation precluded further surgical intervention. Conclusion: IOL-exchange appears to be a useful tool in the management of iatrogenic pigment dispersion glaucoma due to inappropriate IOL implantation. This cause-oriented approach seems to be effective in controlling IOP, but should be offered only if safety criteria are met. How to cite this article: Van Mierlo C, Abegao Pinto L, Stalmans I. Surgical Management of Iatrogenic Pigment Dispersion Glaucoma. J Curr Glaucoma Pract 2015;9(1):28-32. PMID:26997830

  3. Pigmentation, pleiotropy, and genetic pathways in humans and mice

    SciTech Connect

    Barsh, G.S.

    1995-10-01

    Some of the most striking polymorphisms in human populations affect the color of our eyes, hair, or skin. Despite some simple lessons from high school biology (blue eyes are recessive; brown are dominant), the genetic basis of such phenotypic variability has, for the most part, eluded Mendelian description. A logical place to search for the keys to understanding common variation in human pigmentation are genes in which defects cause uncommon conditions such as albinism or piebaldism. The area under this lamppost has recently gotten larger, with two articles, one in this issue of the Journal, that describe the map position for Hermansky-Pudlak syndrome (HPS) and with the recent cloning of a gene that causes X-linked ocular albinism (OA1). In addition, a series of three recent articles in Cell demonstrate (1) that defects in the gene encoding the endothelin B (ET{sub B}) receptor cause hypopigmentation and Hirschsprung disease in a Mennonite population and the mouse mutation piebald(s) and (2) that a defect in the edn3 gene, which encodes one of the ligands for the ET{sub B} receptor, causes the lethal spotting (ls) mouse mutation. 47 refs., 1 fig.

  4. The African eye worm: a case report and review.

    PubMed

    Ali, Sadia; Fisher, Melanie; Juckett, Gregory

    2008-01-01

    Loiasis, caused by the filarial nematode Loa loa, is often asymptomatic but frequently manifests as episodic angioedema and periocular migration of adult worms. Hence also known as the eye worm.(1) It is rarely encountered in the United States among travelers and immigrants. This report describes a case of loiasis in a Cameroonian student seen at a US university clinic. PMID:18217870

  5. Eye burning - itching and discharge

    MedlinePlus

    ... allergies or hay fever Infections, bacterial or viral ( conjunctivitis or pink eye) Chemical irritants (such as chlorine ... to help with allergies. Pink eye or viral conjunctivitis causes a red or bloodshot eye and excessive ...

  6. Surface modification for aluminium pigment inhibition.

    PubMed

    Karlsson, Philip; Palmqvist, Anders E C; Holmberg, Krister

    2006-12-21

    This review concerns surface treatment of aluminium pigments for use in water borne coatings. Aluminium pigments are commonly used in coatings to give a silvery and shiny lustre to the substrate. Such paints and inks have traditionally been solvent borne, since aluminium pigment particles react with water. For environmental and health reasons solvent borne coatings are being replaced by water borne and the aluminium pigments then need to be surface modified in order to stand exposure to water. This process is called inhibition and both organic and inorganic substances are used as inhibiting agents. The organic inhibiting agents range from low molecular weight substances, such as phenols and aromatic acids, via surfactants, in particular alkyl phosphates and other anionic amphiphiles, to high molecular weight compounds, such as polyelectrolytes. A common denominator for them all is that they contain a functional group that interacts specifically with aluminium at the surface. A particularly strong interaction is obtained if the inhibiting agent contains functional groups that form chelating complex with surface Al(III). Encapsulation of the pigment can be made by in situ polymerization at the surface of the pigment and a recent approach is to have the polymerization occur within a double layer of adsorbed surfactant. The inorganic route is dominated by coating with silica, and recent progress has been made using an alkoxide, such as tetraethoxysilane as silica precursor. Such silica coated aluminium pigments are comparable in performance to chromate inhibited pigments and thus offer a possible heavy metal-free alternative. There are obvious connections between surface modifications made to prevent the pigment to react with water and inhibition of corrosion of macroscopic aluminium surfaces. PMID:17239333

  7. Exosomes released by keratinocytes modulate melanocyte pigmentation

    PubMed Central

    Cicero, Alessandra Lo; Delevoye, Cédric; Gilles-Marsens, Floriane; Loew, Damarys; Dingli, Florent; Guéré, Christelle; André, Nathalie; Vié, Katell; van Niel, Guillaume; Raposo, Graça

    2015-01-01

    Cells secrete extracellular vesicles (EVs), exosomes and microvesicles, which transfer proteins, lipids and RNAs to regulate recipient cell functions. Skin pigmentation relies on a tight dialogue between keratinocytes and melanocytes in the epidermis. Here we report that exosomes secreted by keratinocytes enhance melanin synthesis by increasing both the expression and activity of melanosomal proteins. Furthermore, we show that the function of keratinocyte-derived exosomes is phototype-dependent and is modulated by ultraviolet B. In sum, this study uncovers an important physiological function for exosomes in human pigmentation and opens new avenues in our understanding of how pigmentation is regulated by intercellular communication in both healthy and diseased states. PMID:26103923

  8. Exosomes released by keratinocytes modulate melanocyte pigmentation.

    PubMed

    Lo Cicero, Alessandra; Delevoye, Cédric; Gilles-Marsens, Floriane; Loew, Damarys; Dingli, Florent; Guéré, Christelle; André, Nathalie; Vié, Katell; van Niel, Guillaume; Raposo, Graça

    2015-01-01

    Cells secrete extracellular vesicles (EVs), exosomes and microvesicles, which transfer proteins, lipids and RNAs to regulate recipient cell functions. Skin pigmentation relies on a tight dialogue between keratinocytes and melanocytes in the epidermis. Here we report that exosomes secreted by keratinocytes enhance melanin synthesis by increasing both the expression and activity of melanosomal proteins. Furthermore, we show that the function of keratinocyte-derived exosomes is phototype-dependent and is modulated by ultraviolet B. In sum, this study uncovers an important physiological function for exosomes in human pigmentation and opens new avenues in our understanding of how pigmentation is regulated by intercellular communication in both healthy and diseased states. PMID:26103923

  9. An apposition-like compound eye with a layered rhabdom in the small diving beetle Agabus japonicus (Coleoptera, Dytiscidae).

    PubMed

    Jia, Lei-Po; Liang, Ai-Ping

    2014-11-01

    The fine structure of the compound eyes of the adult diving beetle Agabus japonicus is described with light, scanning, and transmission electron microscopy. The eye of A. japonicus is mango-shaped and consists of about 985 ommatidia. Each ommatidium is composed of a corneal facet lens, an eucone type of crystalline cone, a fused layered rhabdom with a basal rhabdomere, seven retinula cells (including six distal cells and one basal cell), two primary pigment cells and an undetermined number of secondary pigment cells that are restricted to the distalmost region of the eye. A clear-zone, separating dioptric apparatus from photoreceptive structures, is not developed and the eye thus resembles an apposition eye. The cross-sectional areas of the rhabdoms are relatively large indicative of enhanced light-sensitivity. The distal and central region of the rhabdom is layered with interdigitating microvilli suggesting polarization sensitivity. According to the features mentioned above, we suggest that 1) the eye, seemingly of the apposition type, occurs in a taxon for which the clear-zone (superposition) eye is characteristic; 2) the eye possesses adaptations to function in a dim-light environment; 3) the eye may be sensitive to underwater polarized light or linearly water-reflected polarized light. PMID:24889009

  10. The eye as an organizer of craniofacial development

    PubMed Central

    Kish, Phillip E.; Bohnsack, Brenda L; Gallina, Donika D.; Kasprick, Daniel S.

    2013-01-01

    The formation and invagination of the optic stalk coincides with the migration of cranial neural crest (CNC) cells, and a growing body of data reveals that the optic stalk and CNC cells communicate to lay the foundations for periocular and craniofacial development. Following migration, the interaction between the developing eye and surrounding periocular mesenchyme (POM) continues, leading to induction of transcriptional regulatory cascades that regulate craniofacial morphogenesis. Studies in chick, mice and zebrafish have revealed a remarkable level of genetic and mechanistic conservation, affirming the power of each animal model to shed light on the broader morphogenic process. This review will focus on the role of the developing eye in orchestrating craniofacial morphogenesis, utilizing morphogenic gradients, paracrine signaling, and transcriptional regulatory cascades to establish an evolutionarily-conserved facial architecture. We propose that in addition to the forebrain, the eye functions during early craniofacial morphogenesis as a key organizer of facial development, independent of its role in vision. PMID:21309065

  11. Human skin pigmentation: melanocytes modulate skin color in response to stress.

    PubMed

    Costin, Gertrude-E; Hearing, Vincent J

    2007-04-01

    All organisms, from simple invertebrates to complex human beings, exist in different colors and patterns, which arise from the unique distribution of pigments throughout the body. Pigmentation is highly heritable, being regulated by genetic, environmental, and endocrine factors that modulate the amount, type, and distribution of melanins in the skin, hair, and eyes. In addition to its roles in camouflage, heat regulation, and cosmetic variation, melanin protects against UV radiation and thus is an important defense system in human skin against harmful factors. Being the largest organ of the body that is always under the influence of internal and external factors, the skin often reacts to those agents by modifying the constitutive pigmentation pattern. The focus of this review is to provide an updated overview of important physiological and biological factors that increase pigmentation and the mechanisms by which they do so. We consider endocrine factors that induce temporary (e.g., during pregnancy) or permanent (e.g., during aging) changes in skin color, environmental factors (e.g., UV), certain drugs, and chemical compounds, etc. Understanding the mechanisms by which different factors and compounds induce melanogenesis is of great interest pharmaceutically (as therapy for pigmentary diseases) and cosmeceutically (e.g., to design tanning products with potential to reduce skin cancer risk). PMID:17242160

  12. Pigmented median raphe cyst of the penis with consideration of the possible mechanism of melanocytic colonization: A case report.

    PubMed

    Ishida, Mitsuaki; Iwai, Muneo; Yoshida, Keiko; Kagotani, Akiko; Okabe, Hidetoshi

    2014-02-01

    Median raphe cyst is a rare lesion located on the median raphe. The cyst wall is lined by cuboidal to columnar cells, transitional (urothelial) cells, stratified squamous cells or a mixture of these. The normal urethral mucosa and the median raphe cyst usually lack melanocytes and/or melanin pigment. However, albeit extremely rare, the presence of melanin pigment and/or melanocytes in median raphe cyst, namely pigmented median raphe cyst, has been previously reported. The current case report presents the sixth case of pigmented median raphe cyst and discusses the possible mechanism of melanocytic colonization in this tumor. A 48-year-old male presented with a nodule on the ventral surface of the penis. Histopathological study revealed that the cyst wall was covered by uniform bland cuboidal to urothelial cells. The peculiar observation was the presence of dendritic melanocytes among the epithelial cells. Therefore, a diagnosis of pigmented median raphe cyst was determined. Immunohistochemically, stem cell factor and endothelin-1 were not expressed in the epithelial cells of the cyst wall. It is well-known that melanocytes are rarely found in various non-melanocytic tumors, a phenomenon termed 'colonization'. The mechanism by which melanocytes appear in median raphe cyst remains unclear. The present report is the first to demonstrate that melanocytic proliferation and differentiation factors, such as stem cell factor and endothelin-1, are not involved in the pigmentation of median raphe cyst. In addition, aberrant melanocytic migration may contribute to the development of this type of lesion. PMID:24396444

  13. [Treatment of eye allergies].

    PubMed

    Kari, Osmo; Saari, K Matti

    2012-01-01

    Seasonal atopic conjunctivitis is treated with antihistamines, cromoglycate and short courses of corticosteroids, in severe cases with subcutaneous or sublingual immunotherapy. Chronic conjunctivitis requires year-round treatment with mast cell stabilizers, antihistamines or topical corticosteroids. Long-term treatment of atopic blepharoconjunctivitis consists of tacrolimus or pimecrolimus cream. For atopic keratoconjunctivitis corticosteroid and, if necessary, cyclosporine eye drops are needed. First-line therapy of vernal conjunctivitis involves mast cell stabilizers and, if necessary, corticosteroid eye drops. Treatment of non-allergic eosinophilic conjunctivitis involves mast cell stabilizers, corticosteroid and, if necessary, cyclosporine eye drops. PMID:22428383

  14. Eye-Safe Lidar

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.

    1989-01-01

    Laser infrared radar (lidar) undergoing development harmless to human eyes, consists almost entirely of solid-state components, and offers high range resolution. Operates at wavelength of about 2 micrometers. If radiation from such device strikes eye, almost completely absorbed by cornea without causing damage, even if aimed directly at eye. Continuous-wave light from laser oscillator amplified and modulated for transmission from telescope. Small portion of output of oscillator fed to single-mode fiber coupler, where mixed with return pulses. Intended for remote Doppler measurements of winds and differential-absorption measurements of concentrations of gases in atmosphere.

  15. Conservation of the chromatophore pigment response.

    PubMed

    Dukovcic, Stephanie R; Hutchison, Janine R; Trempy, Janine E

    2010-08-01

    Toxicant sensing technology has evolved to include biological sensors, such as cell-based biosensors, which rely on viable cells to convey a measurable physiological signal. Chromatophores are a class of pigment cells that have been investigated as cell-based biosensors. We report the characterization of Oncorhynchus tshawytscha melanophores and describe the melanophore pigment response to neurotransmitters in terms of pigment area occupied. Compared with the previously described model, Betta splendens erythrophores, O. tshawytscha melanophores responded similarly, indicating that pigment responses are biologically conserved between these two species. Additionally, melanophores responded to mercuric chloride and sodium arsenite, similar to B. splendens erythrophores, suggesting that melanophores can be used as detectors for environmental toxicants. This report highlights the potential of O. tshawytscha melanophores to be used as cell-based biosensors to address environmental toxicity, and warrants a continued investigation to strengthen this technology and its applications. PMID:20809546

  16. Optically variable films, pigments, and inks

    NASA Astrophysics Data System (ADS)

    Phillips, Roger W.

    1990-12-01

    Optically variable thin film coatings have been prepared on rolls of polyester film by depositing thin multi-layers in a vacuum roll coater. Such coatings can be removed from the polyester film and ground into optically variable pigments for printing inks. Various printing inks including gravure, flexographic, and Intaglio inks have been prepared from these pigments, and printed images using these inks have been obtained from commercial printing presses. These optically variable systems have been used on various security documents to prevent counterfeiting with color copiers. Unique colors, color shifting effects, and other optical properties have been obtained by combining non-optically variable pigment and dyes with this light interference pigment. The merits of this new ink relative to other optically variable systems are color uniformity, print quality, its ready use on existing printing presses, and high security.

  17. Pigments of fly agaric (Amanita muscaria).

    PubMed

    Stintzing, Florian; Schliemann, Willibald

    2007-01-01

    The complex pigment pattern of fly agaric (Amanita muscaria) cap skins has been studied by LC-DAD and mass spectrometry. Among the betaxanthins the corresponding derivatives of serine, threonine, ethanolamine, alanine, Dopa, phenylalanine and tryptophan are reported for the first time to contribute to the pigment pattern of fly agarics. Betalamic acid, the chromophoric precursor of betaxanthins and betacyanins, muscaflavin and seco-dopas were also detected. Furthermore, the red-purple muscapurpurin and the red muscarubrin were tentatively assigned while further six betacyanin-like components could not be structurally allocated. Stability studies indicated a high susceptibility of pigment extracts to degradation which led to rapid colour loss thus rendering a complete characterization of betacyanin-like compounds impossible at present. Taking into account these difficulties the presented results may be a starting point for a comprehensive characterization of the pigment composition of fly agarics. PMID:18274277

  18. A Case of Pigmented Mammary Paget's Disease

    PubMed Central

    Kim, Ji Eun; Kang, Myung Seung; Kim, Joung Soo

    2008-01-01

    Pigmented mammary Paget's disease is a uncommon clinicopathologic variant of mammary Paget's disease, and this mimics malignant melanoma both clinically and histopathologically. Herein, we report on a rare case of pigmented mammary Paget's disease. An 81-year-old woman presented with 2.5×1 cm sized, red and brown, eczematous plaque on her right areola, and she'd had this lesion for 3 years. Histopathology showed large, atypical cells with large nuclei and abundant pale cytoplasm throughout the epidermis. Dispersed melanocytes were noted in the epidermis and some of the Paget's cells contained melanin within their cytoplasm. Immunohistochemical studies demonstrated that the intraepidermal pagetoid cells were positive for cytokeratin 7; in contrast, they were negative for S-100, Periodic-acid Schiff (PAS), Alcian blue at PH 2.5, HMB-45 and carninoembryonic antigen (CEA). We recommend that pigmented mammary Paget's disease should be included in the differential diagnosis of pigmented lesions on the nipple. PMID:27303202

  19. EFFICIENT GENE TRANSFER TO RETINAL PIGMENT EPITHELIUM CELLS WITH LONG-TERM EXPRESSION

    PubMed Central

    CHENG, LINGYUN; TOYOGUCHI, MITSUKO; LOONEY, DAVID J.; LEE, JEFFERY; DAVIDSON, MARIE C.; FREEMAN, WILLIAM R.

    2006-01-01

    Purpose To evaluate the safety and efficiency of feline immunodeficiency virus (FIV) vectors for gene delivery into the mammalian retina. Methods A first-generation FIV vector was constructed and administered into rabbit eyes at two different concentrations by intravitreal or subretinal routes. A second-generation FIV vector was also constructed and administered subretinally into both rabbit and rat eyes at the same concentration. After vector administration, eyes were monitored using slit-lamp biomicroscopy, indirect ophthalmoscopy, fundus photography, and electroretinogram. After the rabbits were killed, eye tissues were processed for light microscopy and immunohistochemical analysis. Results Administration of both first- and second-generation FIV vectors produced transient vitritis and/or papillitis in rabbits, without other pathologic abnormalities. Retinal pigment epithelium (RPE) cells were the predominant cell type transduced in rabbit eyes, but ganglion cells and Müller cells were also transduced. Transduction was confined to the retinal bleb area. The second-generation FIV vector transduced RPE cells much more efficiently than the first-generation vector (95% vs. 4.5%, respectively; P = 0.0015) in rabbit eyes. In contrast, no toxicity was evident over a 24- to 25-month follow-up period after injection of the second-generation FIV vector into rat eyes. Tropism in the rat eye was similar, including RPE and ganglion cells, and the RPE transduction rate was also high (50%). Transgene expression was persistent in both species over the duration of the experiment. Conclusion Second-generation FIV vectors can efficiently transfer genes into RPE cells with resulting long-term expression, properties potentially valuable to gene therapy approaches to some retinal diseases. PMID:15689811

  20. Autologous serum eye drops for dry eye

    PubMed Central

    Pan, Qing; Angelina, Adla; Zambrano, Andrea; Marrone, Michael; Stark, Walter J; Heflin, Thomas; Tang, Li; Akpek, Esen K

    2014-01-01

    Background Theoretically, autologous serum eye drops (AS) have a potential advantage over traditional therapies based on the assumption that AS serve not only as a lacrimal substitute to provide lubrication, but also contain other biochemical components mimicking natural tears more closely. The application of AS in dry eye treatment has gained popularity as a second-line therapy in the treatment of dry eye. Published studies on the subject indicate that autologous serum could be an effective treatment for dry eye. Objectives To evaluate the efficacy and safety of AS compared to artificial tears for treating dry eye. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLD MEDLINE, (January 1950 to April 2013), EMBASE (January 1980 to April 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to April 2013), the meta Register of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We also searched the Science Citation Index Expanded database (September 2013) and reference lists of included studies. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 15 April 2013. Selection criteria We included randomized controlled trials (RCTs) in which AS was compared to artificial tears in the treatment of dry eye in adults. Data collection and analysis Two review authors independently screened all titles and abstracts and assessed full-text articles of potentially eligible trials. Two review authors extracted data and assessed the methodological quality and characteristics of the included trials.We contacted investigators for missing data

  1. Diseases of the eye of farmed shrimp Penaeus monodon.

    PubMed

    Smith, P T

    2000-12-21

    Lesions were found in the eyes of cultured shrimp Penaeus monodon that displayed non-specific signs of disease, including lethargy, dark pigmentation, brown gills, empty midgut, anorexia, white tail muscle, necrosis of uropods and fouled cuticle. Eye lesions were associated with sexual development in moribund shrimp in at least 1 disease event. Suppurative inflammation, granuloma and malacia were observed in histological examination of the eye and the causative agents of lesions appear to be Vibrio spp. and a rod-shaped virus (similar to Lymphoid Organ Virus, Gill-Associated Virus [GAV] and Yellow-Head Virus). Suppurative inflammation was characterised by edema, infiltration of haemocytes and local sites of abscesses. Eyes with granuloma usually appeared white in pond-side examinations, and histology showed that fibrous tissue replaced ommatidia, ganglia and internal structures of the eye. Malacia of the eye was characterised by necrosis of nervous tissue, vacuolation and vascular proliferation in the medulla ganglia. Levels of presumptive Vibrionaceace were high in moribund specimens and Gram-negative rods were observed in some specimens as free particles in the interstitial fluid and haemolymph in the eye. Transmission electron microscopy showed that nerve cells in the fasciculated zone (near the basement membrane) contained cytoplasmic vesicles (1 to 3 microm in diameter) with particles (15 to 26 nm in diameter) and rod-shaped nucleocapsids. The rods were similar to those of GAV and were 130 to 260 nm long, 10 to 16 nm in diameter and had helical symmetry with a screw-like thread (2.4 to 3.5 nm pitch). Also, unidentified enveloped virions, averaging 74 nm in diameter, were observed in cytoplasmic vesicles in the fasciculated zone. In conclusion, it is suggested that bacterial and viral infections of the eye could result in impaired neuroendocrine functions, which may cause a range of clinical signs of disease. PMID:11206731

  2. New Directions in Phthalocyanine Pigments

    NASA Technical Reports Server (NTRS)

    Vandemark, Michael R.

    1992-01-01

    The objectives were the following: (1) investigation of the synthesis of new phthalocyanines; (2) characterization of the new phthalocyanines synthesized; (3) investigate the properties of the newly synthesized phthalocyanines with emphasis on UV protection of plastics and coatings; and (4) utilize quantum mechanics to evaluate the structural relationships with possible properties and synthetic approaches. The proposed research targeted the synthesis of phthalocyanines containing an aromatic bridge between two phthalocyanine rings. The goal was to synthesize pigments which would protect plastics when exposed to the photodegradation effects of the sun in space. The stability and extended conjugation of the phthalocyanines offer a unique opportunity for energy absorption and numerous radiative and non-radiative energy loss mechanisms. Although the original targeted phthalocyanines were changed early in the project, several new and unique phthalocyanine compounds were prepared. The basic goals of this work were met and some unique and unexpected outcomes of the work were the result of the integral use of quantum mechanics and molecular modeling with the synthetic effort.

  3. Drosophila Vps16A is required for trafficking to lysosomes and biogenesis of pigment granules.

    PubMed

    Pulipparacharuvil, Suprabha; Akbar, Mohammed Ali; Ray, Sanchali; Sevrioukov, Evgueny A; Haberman, Adam S; Rohrer, Jack; Krämer, Helmut

    2005-08-15

    Mutations that disrupt trafficking to lysosomes and lysosome-related organelles cause multiple diseases, including Hermansky-Pudlak syndrome. The Drosophila eye is a model system for analyzing such mutations. The eye-color genes carnation and deep orange encode two subunits of the Vps-C protein complex required for endosomal trafficking and pigment-granule biogenesis. Here we demonstrate that dVps16A (CG8454) encodes another Vps-C subunit. Biochemical experiments revealed a specific interaction between the dVps16A C-terminus and the Sec1/Munc18 homolog Carnation but not its closest homolog, dVps33B. Instead, dVps33B interacted with a related protein, dVps16B (CG18112). Deep orange bound both Vps16 homologs. Like a deep orange null mutation, eye-specific RNAi-induced knockdown of dVps16A inhibited lysosomal delivery of internalized ligands and interfered with biogenesis of pigment granules. Ubiquitous knockdown of dVps16A was lethal. Together, these findings demonstrate that Drosophila Vps16A is essential for lysosomal trafficking. Furthermore, metazoans have two types of Vps-C complexes with non-redundant functions. PMID:16046475

  4. The ‘division of labour’ model of eye evolution

    PubMed Central

    Arendt, Detlev; Hausen, Harald; Purschke, Günter

    2009-01-01

    The ‘division of labour’ model of eye evolution is elaborated here. We propose that the evolution of complex, multicellular animal eyes started from a single, multi-functional cell type that existed in metazoan ancestors. This ancient cell type had at least three functions: light detection via a photoreceptive organelle, light shading by means of pigment granules and steering through locomotor cilia. Located around the circumference of swimming ciliated zooplankton larvae, these ancient cells were able to mediate phototaxis in the absence of a nervous system. This precursor then diversified, by cell-type functional segregation, into sister cell types that specialized in different subfunctions, evolving into separate photoreceptor cells, shading pigment cells (SPCs) or ciliated locomotor cells. Photoreceptor sensory cells and ciliated locomotor cells remained interconnected by newly evolving axons, giving rise to an early axonal circuit. In some evolutionary lines, residual functions prevailed in the specialized cell types that mirror the ancient multi-functionality, for instance, SPCs expressing an opsin as well as possessing rhabdomer-like microvilli, vestigial cilia and an axon. Functional segregation of cell types in eye evolution also explains the emergence of more elaborate photosensory–motor axonal circuits, with interneurons relaying the visual information. PMID:19720646

  5. Pseudotumoral and Multiple Retinal Pigment Epithelium Proliferation in Vogt-Koyanagi-Harada Disease.

    PubMed

    Yepez, Juan B; Murati, Felipe; Petitto, Michele; Arevalo, J Fernando

    2015-01-01

    We report a case of pseudotumoral retinal pigment epithelium (RPE) proliferation in Vogt-Koyanagi-Harada (VKH) disease, in a 50-year-old female who presented with a juxtapapillary and peripheral subretinal hyperpigmented lesions in the left eye and "sunset glow fundus," hyperpigmented striae, and multiple atrophic chorioretinal spots in the periphery. The darkly pigmented exuberant larger subretinal mass extended to the periphery with associated subretinal fibrosis. This patient demonstrated the entire clinical presentation of VKH disease, which tends to course with a chronic, bilateral, granulomatous panuveitis and exudative retinal detachment associated with poliosis, vitiligo, alopecia, and central nervous system and auditory signs. Our case is unique for the presence of exuberant, pseudotumoral RPE proliferation at the juxtapapillary region and peripheral area. Although this complication has rarely been reported, a high index of suspicion is warranted for early diagnosis and avoids unnecessary treatments of a pseudotumor. PMID:26509089

  6. Reverse pupillary block associated with pigment dispersion syndrome after in-the-bag intraocular lens implantation.

    PubMed

    Itagaki, Hideo; Kunikata, Toshio; Hiratsuka, Kentaro; Saito, Junichiro; Oshika, Tetsuro

    2013-12-01

    A 61-year-old man with high myopia who had received a systemic α1A-adrenoceptor antagonist had phacoemulsification and in-the-bag intraocular lens implantation in the right eye. One day postoperatively, marked pigment dispersion in the anterior chamber, posterior bowing of the iris, and iridodonesis were noted associated with a subsequent elevation in intraocular pressure (IOP). Pharmacological pupil dilation was effective in reducing pigment dispersion and IOP, and laser peripheral iridotomy was performed to alleviate posterior bowing of the iris. We hypothesize that dynamic changes in the aqueous humor flow by cataract surgery and latent flaccidity of the iris due to the systemic α1A-adrenoceptor antagonist caused reverse pupillary block. High myopia may be another risk factor for this complication. PMID:24140374

  7. Distribution of melanosomes across the retinal pigment epithelium of a hooded rat: implications for light damage

    SciTech Connect

    Howell, W.L.; Rapp, L.M.; Williams, T.P.

    1982-02-01

    Distribution of melanosomes across the retinal pigment epithelium of hooded rats (Long-Evans) is studied at the light microscopic and electron microscopic levels. This distribution is shown to be nonuniform: more melanosomes exist in the periphery than elsewhere and, importantly, there are very few melanosomes in a restricted area of the central portion of the superior hemisphere compared with the corresponding part of the inferior hemisphere. The region with fewest melanosomes is precisely the one that is highly susceptible to light damage. Because this region is the same in both pigmented and albino eyes, the paucity of melanin in this region is not the cause of its great sensitivity to light damage. Nor does light cause the nonuniform distribution of melanin. A possible explanation, involving a proposed vestigial tapetum, is given in order to explain the correlation of melanosome counts and sensitivity to light damage.

  8. Pseudotumoral and Multiple Retinal Pigment Epithelium Proliferation in Vogt-Koyanagi-Harada Disease

    PubMed Central

    Yepez, Juan B.; Murati, Felipe; Petitto, Michele; Arevalo, J. Fernando

    2015-01-01

    We report a case of pseudotumoral retinal pigment epithelium (RPE) proliferation in Vogt-Koyanagi-Harada (VKH) disease, in a 50-year-old female who presented with a juxtapapillary and peripheral subretinal hyperpigmented lesions in the left eye and “sunset glow fundus,” hyperpigmented striae, and multiple atrophic chorioretinal spots in the periphery. The darkly pigmented exuberant larger subretinal mass extended to the periphery with associated subretinal fibrosis. This patient demonstrated the entire clinical presentation of VKH disease, which tends to course with a chronic, bilateral, granulomatous panuveitis and exudative retinal detachment associated with poliosis, vitiligo, alopecia, and central nervous system and auditory signs. Our case is unique for the presence of exuberant, pseudotumoral RPE proliferation at the juxtapapillary region and peripheral area. Although this complication has rarely been reported, a high index of suspicion is warranted for early diagnosis and avoids unnecessary treatments of a pseudotumor. PMID:26509089

  9. Phenolic compounds and bioactivities of pigmented rice.

    PubMed

    Deng, Gui-Fang; Xu, Xiang-Rong; Zhang, Yuan; Li, Dan; Gan, Ren-You; Li, Hua-Bin

    2013-01-01

    The pigmented rice has been consumed in China, Japan, and Korea for a long time. It has been used for strengthening kidney function, treating anemia, promoting blood circulation, removing blood stasis, treating diabetes, and ameliorating sight in traditional Chinese medicine. The extracts from pigmented rice are used as natural food colorants in bread, ice cream, and liquor as well as functional food. The pigmented rice is mainly black, red, and dark purple rice, and contains a variety of flavones, tannin, phenolics, sterols, tocols, γ-oryzanols, amino acids, and essential oils. Anthocyanins are thought as major functional components of pigmented rice. Several anthocyanins have been isolated and identified from the pigmented rice, including cyanidin 3-glucoside, cyanidin 3-galactoside, cyanidin 3-rutinoside, cyanidin 3,5-diglucoside, malvidin 3-galactoside, peonidin 3-glucoside, and pelargonidin 3,5-diglucoside. This review provides up-to-date coverage of pigmented rice in regard to bioactive constituents, extraction and analytical methods, and bioactivities. Special attention is paid to the bioactivities including antioxidant and free radical scavenging, antitumor, antiatherosclerosis, hypoglycemic, and antiallergic activities. PMID:23216001

  10. FTIR study of primate color visual pigments

    PubMed Central

    Katayama, Kota; Kandori, Hideki

    2015-01-01

    How do we distinguish colors? Humans possess three color pigments; red-, green-, and blue-sensitive proteins, which have maximum absorbance (λmax) at 560, 530, and 420 nm, respectively, and contribute to normal human trichromatic vision (RGB). Each color pigments consists of a different opsin protein bound to a common chromophore molecule, 11-cis-retinal, whereas different chromophore-protein interactions allow preferential absorption of different colors. However, detailed experimental structural data to explain the molecular basis of spectral tuning of color pigments are lacking, mainly because of the difficulty in sample preparation. We thus started structural studies of primate color visual pigments using low-temperature Fourier-transform infrared (FTIR) spectroscopy, which needs only 0.3 mg protein for a single measurement. Here we report the first structural data of monkey red- (MR) and green- (MG) sensitive pigments, in which the information about the protein, retinal chromophore, and internal water molecules is contained. Molecular mechanism of color discrimination between red and green pigments will be discussed based on the structural data by FTIR spectroscopy. PMID:27493516

  11. Microspectrophotometry of arthropod visual screening pigments.

    PubMed

    Strother, G K; Casella, A J

    1972-05-01

    Absorption spectra of visual screening pigments obtained in vitro with a microspectrophotometer using frozen sections are given for the insects Musca domestica, Phormia regina, Libellula luctuosa, Apis mellifera (worker honeybee only), Drosophila melanogaster (wild type only) and the arachnids Lycosa baltimoriana and Lycosa miami. The spectral range covered is 260-700 nm for Lycosa and Drosophila and 310-700 nm for the remainder of the arthropods. A complete description of the instrumentation is given. For the flies, Phormia and Musca, light absorption by the yellow and red pigments is high from 310 to about 610 nm. This implies that for these insects there should be no wavelength shift in electroretinogram (ERG) results due to light leakage among neighboring ommatidia for this wavelength range. The same comment applies to Calliphora erythrocephala, which is known to have similar screening pigments. For some of the insects studied a close correspondence is noted between screening pigment absorption spectra and spectral sensitivity curves for individual photoreceptors, available in the literature. In some cases the screening pigment absorption spectra can be related to chemical extraction results, with the general observation that some of the in vitro absorption peaks are shifted to the red. The Lycosa, Apis, and Libellula dark red pigments absorb strongly over a wide spectral range and therefore prevent chemical identification. PMID:4623852

  12. Dermoscopic Features of Facial Pigmented Skin Lesions

    PubMed Central

    Goncharova, Yana; Attia, Enas A. S.; Souid, Khawla; Vasilenko, Inna V.

    2013-01-01

    Four types of facial pigmented skin lesions (FPSLs) constitute diagnostic challenge to dermatologists; early seborrheic keratosis (SK), pigmented actinic keratosis (AK), lentigo maligna (LM), and solar lentigo (SL). A retrospective analysis of dermoscopic images of histopathologically diagnosed clinically-challenging 64 flat FPSLs was conducted to establish the dermoscopic findings corresponding to each of SK, pigmented AK, LM, and SL. Four main dermoscopic features were evaluated: sharp demarcation, pigment pattern, follicular/epidermal pattern, and vascular pattern. In SK, the most specific dermoscopic features are follicular/epidermal pattern (cerebriform pattern; 100% of lesions, milia-like cysts; 50%, and comedo-like openings; 37.50%), and sharp demarcation (54.17%). AK and LM showed a composite characteristic pattern named “strawberry pattern” in 41.18% and 25% of lesions respectively, characterized by a background erythema and red pseudo-network, associated with prominent follicular openings surrounded by a white halo. However, in LM “strawberry pattern” is widely covered by psewdonetwork (87.5%), homogenous structureless pigmentation (75%) and other vascular patterns. In SL, structureless homogenous pigmentation was recognized in all lesions (100%). From the above mentioned data, we developed an algorithm to guide in dermoscopic features of FPSLs. PMID:23431466

  13. The more the merrier? How a few SNPs predict pigmentation phenotypes in the Northern German population.

    PubMed

    Caliebe, Amke; Harder, Melanie; Schuett, Rebecca; Krawczak, Michael; Nebel, Almut; von Wurmb-Schwark, Nicole

    2016-05-01

    Human pigmentation traits are of great interest to many research areas, from ancient DNA analysis to forensic science. We developed a gene-based predictive model for pigmentation phenotypes in a realistic target population for forensic case work from Northern Germany and compared our model with those brought forth by previous studies of genetically more heterogeneous populations. In doing so, we aimed at answering the following research questions: (1) do existing models allow good prediction of high-quality phenotypes in a genetically similar albeit more homogeneous population? (2) Would a model specifically set up for the more homogeneous population perform notably better than existing models? (3) Can the number of markers included in existing models be reduced without compromising their predictive capability in the more homogenous population? We investigated the association between eye, hair and skin colour and 12 candidate single-nucleotide polymorphisms (SNPs) from six genes. Our study comprised two samples of 300 and 100 individuals from Northern Germany. SNP rs12913832 in HERC2 was found to be strongly associated with blue eye colour (odds ratio=40.0, P<1.2 × 10(-4)) and to yield moderate predictive power (AUC: 77%; sensitivity: 90%, specificity: 63%, both at a 0.5 threshold for blue eye colour probability). SNP associations with hair and skin colour were weaker and genotypes less predictive. A comparison with two recently published sets of markers to predict eye and hair colour revealed that the consideration of additional SNPs with weak-to-moderate effect increased the predictive power for eye colour, but not for hair colour. PMID:26286644

  14. Diabetic Eye Disease

    MedlinePlus

    ... Health Education Program Diabetic Eye Disease Education Program Glaucoma Education Program Low Vision Education Program Spanish-language ... FAQ Watch out for your vision! Glossary Resources Glaucoma Glaucoma Home How Much Do You Know? What ...

  15. Dry eye syndrome

    MedlinePlus

    ... of dry eyes include: Dry environment or workplace (wind, air conditioning) Sun exposure Smoking or second-hand ... NOT smoke and avoid second-hand smoke, direct wind, and air conditioning. Use a humidifier, especially in ...

  16. Amblyopia: Lazy Eye Treatment

    MedlinePlus

    ... Choosing Safe Toys this Holiday Dec 02, 2015 Digital Glasses For Lazy Eye Nov 19, 2015 Follow The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About ...

  17. Amblyopia: Lazy Eye Symptoms

    MedlinePlus

    ... Choosing Safe Toys this Holiday Dec 02, 2015 Digital Glasses For Lazy Eye Nov 19, 2015 Follow The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About ...

  18. Amblyopia: Lazy Eye Diagnosis

    MedlinePlus

    ... Choosing Safe Toys this Holiday Dec 02, 2015 Digital Glasses For Lazy Eye Nov 19, 2015 Follow The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About ...

  19. What Is Dry Eye?

    MedlinePlus

    ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Academy Publications EyeNet Ophthalmology Information for: International Ophthalmologists Media Medical Students Patients and Public Technicians and Nurses ...

  20. Down Syndrome: Eye Problems

    MedlinePlus

    American Association for Pediatric Ophthalmology and Strabismus Home About AAPOS Patient Info Resources Allied Health News & Events Meetings J AAPOS American Association for Pediatric Ophthalmology and Strabismus Eye Terms ...

  1. Fungal Eye Infections

    MedlinePlus

    ... Zoonotic Infectious Disease Division of Foodborne, Waterborne, and Environmental Diseases Mycotic Diseases Branch Fungal Eye Infections Recommend on ... Zoonotic Infectious Disease Division of Foodborne, Waterborne, and Environmental Diseases Mycotic Diseases Branch File Formats Help: How do ...

  2. Dry eye syndrome

    MedlinePlus

    ... particles that have gotten in. A healthy tear film on the eye is necessary for good vision. ... exam Diagnostic staining of the cornea and tear film Measurement of tear film break-up time (TBUT) ...

  3. Using Eye Makeup

    MedlinePlus

    ... in a moving vehicle. Do not separate your mascara-clumped lashes with sharp items. If you tend ... all eye makeup at night before sleeping, especially mascara that can stick to the lashes. Brush a ...

  4. Anatomy of the Eye

    MedlinePlus

    ... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Anatomy of the Eye En Español Read in Chinese External (Extraocular) Anatomy Extraocular Muscles: There are six muscles that are ...

  5. Melanoma of the eye

    MedlinePlus

    ... modified July 9, 2015. www.cancer.gov/types/eye/hp/intraocular-melanoma-treatment-pdq . Accessed October 7, 2015. Read ... by: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital, Boston, MA. Also reviewed ...

  6. Eye Injuries in Sports

    MedlinePlus

    ... these injuries can be prevented. Overall, basketball and baseball cause the most eye injuries, followed by water ... involve body contact. Some high-risk sports are baseball, basketball, hockey, football, lacrosse, tennis and other racquet ...

  7. Macular pigment optical density: repeatability, intereye correlation, and effect of ocular dominance

    PubMed Central

    Davey, Pinakin Gunvant; Alvarez, Silverio D; Lee, Jessica Y

    2016-01-01

    Purpose To evaluate short-term repeatability, intereye correlation, and effect of ocular dominance on macular pigment optical density (MPOD) measurements obtained using the QuantifEye Heterochromatic Flicker Photometer. Patients and methods A total of 72 study participants were enrolled in this prospective, cross-sectional study. Participants underwent a comprehensive ocular evaluation, including visual acuity, evaluation of ocular dominance, slit lamp examination, intraocular pressure measurement, and optic nerve head and macula analysis using optical coherence tomography and fundus photography. All study participants after initial training underwent MPOD measurement twice in both eyes in a randomized sequence. The repeatability was tested using Altman and Bland plots for first measurements with the second measurements for right eye and left eye and additionally by grouping eyes as a function of ocular dominance. The Pearson correlation coefficient was performed to assess the intereye correlation of MPOD values. Results The mean age of study participants was 35.5 years (range 22–68 years). The mean MPOD measurements for OD (right eye) and OS (left eye) were 0.47 and 0.48, respectively, which followed a normal distribution (Shapiro–Wilk test, P=0.6 and 0.2). The 95% limits of agreement of Altman and Bland plots for the first and second measurements were −0.12 to +0.11 and −0.13 to +0.12 for OD and OS, respectively. The correlation coefficient of mean MPOD measurements of OD and OS was r statistic =0.94 (Pearson correlation coefficient P<0.0001; r2 0.89). The 95% limits of agreement of Altman and Bland plots when evaluated by laterality of eye or by ocular dominance were narrow, with limits of agreement ranging from −0.13 to +0.12. Conclusion The MPOD measurements obtained using the QuantifEye show good short-term repeatability. There is excellent intereye correlation, indicating that the MPOD values of one eye data can predict the fellow eye value with 89

  8. [Straight in the eyes].

    PubMed

    Diop, E; Beylot, V; Berta, C; Dugardin, C; Aigle, L

    2015-01-01

    This case report about a young French soldier hit in the eye by a spitting cobra in the Central African Republic prompts us to review the potential toxicity of this venom to the eyes and the management of this injury. The initial phase is simple to implement, but is often performed badly or not at all because unknown. It is a condition, however, for optimal recovery of the cornea. PMID:26067984

  9. Mutations in the white gene of Drosophila melanogaster affecting ABC transporters that determine eye colouration.

    PubMed

    Mackenzie, S M; Brooker, M R; Gill, T R; Cox, G B; Howells, A J; Ewart, G D

    1999-07-15

    The white, brown and scarlet genes of Drosophila melanogaster encode proteins which transport guanine or tryptophan (precursors of the red and brown eye colour pigments) and belong to the ABC transporter superfamily. Current models envisage that the white and brown gene products interact to form a guanine specific transporter, while white and scarlet gene products interact to form a tryptophan transporter. In this study, we report the nucleotide sequence of the coding regions of five white alleles isolated from flies with partially pigmented eyes. In all cases, single amino acid changes were identified, highlighting residues with roles in structure and/or function of the transporters. Mutations in w(cf) (G589E) and w(sat) (F590G) occur at the extracellular end of predicted transmembrane helix 5 and correlate with a major decrease in red pigments in the eyes, while brown pigments are near wild-type levels. Therefore, those residues have a more significant role in the guanine transporter than the tryptophan transporter. Mutations identified in w(crr) (H298N) and w(101) (G243S) affect amino acids which are highly conserved among the ABC transporter superfamily within the nucleotide binding domain. Both cause substantial and similar decreases of red and brown pigments indicating that both tryptophan and guanine transport are impaired. The mutation identified in w(Et87) alters an amino acid within an intracellular loop between transmembrane helices 2 and 3 of the predicted structure. Red and brown pigments are reduced to very low levels by this mutation indicating this loop region is important for the function of both guanine and tryptophan transporters. PMID:10407069

  10. The pugilistDominant Mutation of Drosophila melanogaster: A Simple-Sequence Repeat Disorder Reveals Localized Transport in the Eye.

    PubMed

    Rong, Yikang S; Golic, Mary M; Golic, Kent G

    2016-01-01

    The pugilist-Dominant mutation results from fusion of a portion of the gene encoding the tri-functional Methylene Tetrahydrofolate Dehydrogenase (E.C.1.5.1.5, E.C.3.5.4.9, E.C.6.3.4.3) to approximately one kb of a heterochromatic satellite repeat. Expression of this fusion gene results in an unusual ring pattern of pigmentation around the eye. We carried out experiments to determine the mechanism for this pattern. By using FLP-mediated DNA mobilization to place different pugD transgenes at pre-selected sites we found that variation in repeat length makes a strong contribution to variability of the pug phenotype. This variation is manifest primarily as differences in the thickness of the pigmented ring. We show that similar phenotypic variation can also be achieved by changing gene copy number. We found that the pugD pattern is not controlled by wingless, which is normally expressed in a similar ring pattern. Finally, we found that physical injury to a pugD eye can lead to pigment deposition in parts of the eye that would not have been pigmented in the absence of injury. Our results are consistent with a model in which a metabolite vital for pigment formation is imported from the periphery of the eye, and pugD limits the extent of its transport towards the center of the eye, thus revealing the existence of a hitherto unknown mechanism of localized transport in the eye. PMID:26999432

  11. The pugilistDominant Mutation of Drosophila melanogaster: A Simple-Sequence Repeat Disorder Reveals Localized Transport in the Eye

    PubMed Central

    Rong, Yikang S.; Golic, Mary M.; Golic, Kent G.

    2016-01-01

    The pugilist-Dominant mutation results from fusion of a portion of the gene encoding the tri-functional Methylene Tetrahydrofolate Dehydrogenase (E.C.1.5.1.5, E.C.3.5.4.9, E.C.6.3.4.3) to approximately one kb of a heterochromatic satellite repeat. Expression of this fusion gene results in an unusual ring pattern of pigmentation around the eye. We carried out experiments to determine the mechanism for this pattern. By using FLP-mediated DNA mobilization to place different pugD transgenes at pre-selected sites we found that variation in repeat length makes a strong contribution to variability of the pug phenotype. This variation is manifest primarily as differences in the thickness of the pigmented ring. We show that similar phenotypic variation can also be achieved by changing gene copy number. We found that the pugD pattern is not controlled by wingless, which is normally expressed in a similar ring pattern. Finally, we found that physical injury to a pugD eye can lead to pigment deposition in parts of the eye that would not have been pigmented in the absence of injury. Our results are consistent with a model in which a metabolite vital for pigment formation is imported from the periphery of the eye, and pugD limits the extent of its transport towards the center of the eye, thus revealing the existence of a hitherto unknown mechanism of localized transport in the eye. PMID:26999432

  12. Eye Protection in Educational Institutions.

    ERIC Educational Resources Information Center

    New Jersey State Dept. of Education, Trenton. Div. of Vocational Education.

    Intended to help reduce the number of school eye injuries in New Jersey, this document begins with a brief review of existing legislation regarding eye protection in educational institutions and a list of elements essential in an eye safety program. Second, eye protection equipment is examined in terms of: the advantages of safety spectacles over…

  13. Eye Safety. Mississippi Industrial Arts.

    ERIC Educational Resources Information Center

    Mississippi State Dept. of Education, Jackson. Div. of Vocational and Technical Education.

    This manual is designed to help industrial arts teachers eliminate student eye injuries within industrial arts programs. Presented first is Mississippi eye safety law. Following a discussion of eye protection equipment, illustrations of eye protection devices are provided. Guidelines are set forth for selecting shade numbers for welding filters.…

  14. The evolution of eyes and visually guided behaviour

    PubMed Central

    Nilsson, Dan-Eric

    2009-01-01

    The morphology and molecular mechanisms of animal photoreceptor cells and eyes reveal a complex pattern of duplications and co-option of genetic modules, leading to a number of different light-sensitive systems that share many components, in which clear-cut homologies are rare. On the basis of molecular and morphological findings, I discuss the functional requirements for vision and how these have constrained the evolution of eyes. The fact that natural selection on eyes acts through the consequences of visually guided behaviour leads to a concept of task-punctuated evolution, where sensory systems evolve by a sequential acquisition of sensory tasks. I identify four key innovations that, one after the other, paved the way for the evolution of efficient eyes. These innovations are (i) efficient photopigments, (ii) directionality through screening pigment, (iii) photoreceptor membrane folding, and (iv) focusing optics. A corresponding evolutionary sequence is suggested, starting at non-directional monitoring of ambient luminance and leading to comparisons of luminances within a scene, first by a scanning mode and later by parallel spatial channels in imaging eyes. PMID:19720648

  15. RPE Cell and Sheet Properties in Normal and Diseased Eyes.

    PubMed

    Rashid, Alia; Bhatia, Shagun K; Mazzitello, Karina I; Chrenek, Micah A; Zhang, Qing; Boatright, Jeffrey H; Grossniklaus, Hans E; Jiang, Yi; Nickerson, John M

    2016-01-01

    Previous studies of human retinal pigment epithelium (RPE) morphology found spatial differences in density: a high density of cells in the macula, decreasing peripherally. Because the RPE sheet is not perfectly regular, we anticipate that there will be differences between conditions and when and where damage is most likely to begin. The purpose of this study is to establish relationships among RPE morphometrics in age, cell location, and disease of normal human and AMD eyes that highlight irregularities reflecting damage. Cadaveric eyes from 11 normal and 3 age-related macular degeneration (AMD) human donors ranging from 29 to 82 years of age were used. Borders of RPE cells were identified with phalloidin. RPE segmentation and analysis were conducted with CellProfiler. Exploration of spatial point patterns was conducted using the "spatstat" package of R. In the normal human eye, with increasing age, cell size increased, and cells lost their regular hexagonal shape. Cell density was higher in the macula versus periphery. AMD resulted in greater variability in size and shape of the RPE cell. Spatial point analysis revealed an ordered distribution of cells in normal and high spatial disorder in AMD eyes. Morphometrics of the RPE cell readily discriminate among young vs. old and normal vs. diseased in the human eye. The normal RPE sheet is organized in a regular array of cells, but AMD exhibited strong spatial irregularity. These findings reflect on the robust recovery of the RPE sheet after wounding and the circumstances under which it cannot recover. PMID:26427486

  16. [[Evolution of Egyptian migration

    PubMed

    Saleh, S A

    1985-01-01

    Changing patterns of Egyptian emigration over the past 30 years are reviewed. Four phases are identified: migration among Arab countries up to 1961, migration to the West for professional advancement, migration for political freedom, and migration to oil-producing countries since 1973 for economic reasons. (SUMMARY IN ENG) PMID:12268794

  17. Cavefish eye loss in response to an early block in retinal differentiation progression.

    PubMed

    Stemmer, Manuel; Schuhmacher, Laura-Nadine; Foulkes, Nicholas S; Bertolucci, Cristiano; Wittbrodt, Joachim

    2015-02-15

    The troglomorphic phenotype shared by diverse cave-dwelling animals is regarded as a classical example of convergent evolution. One unresolved question is whether the characteristic eye loss in diverse cave species is based on interference with the same genetic program. Phreatichthys andruzzii, a Somalian cavefish, has evolved under constant conditions in complete darkness and shows severe troglomorphic characteristics, such as complete loss of eyes, pigments and scales. During early embryonic development, a complete eye is formed but is subsequently lost. In Astyanax mexicanus, another blind cavefish, eye loss has been attributed to interference during eye field patterning. To address whether similar pathways have been targeted by evolution independently, we investigated the retinal development of P. andruzzii, studying the expression of marker genes involved in eye patterning, morphogenesis, differentiation and maintenance. In contrast to Astyanax, patterning of the eye field and evagination of the optic vesicles proceeds without obvious deviation. However, the subsequent differentiation of retinal cell types is arrested during generation of the first-born cell type, retinal ganglion cells, which also fail to project correctly to the optic tectum. Eye degeneration in both species is driven by progressive apoptosis. However, it is retinal apoptosis in Phreatichthys that progresses in a wave-like manner and eliminates progenitor cells that fail to differentiate, in contrast to Astyanax, where lens apoptosis appears to serve as a driving force. Thus, evolution has targeted late retinal differentiation events, indicating that there are several ways to discontinue the development and maintenance of an eye. PMID:25617433

  18. Eye development genes and known syndromes.

    PubMed

    Slavotinek, Anne M

    2011-12-01

    Anophthalmia and microphthalmia (A/M) are significant eye defects because they can have profound effects on visual acuity. A/M is associated with non-ocular abnormalities in an estimated 33-95% of cases and around 25% of patients have an underlying genetic syndrome that is diagnosable. Syndrome recognition is important for targeted molecular genetic testing, prognosis and for counseling regarding recurrence risks. This review provides clinical and molecular information for several of the commonest syndromes associated with A/M: Anophthalmia-Esophageal-Genital syndrome, caused by SOX2 mutations, Anophthalmia and pituitary abnormalities caused by OTX2 mutations, Matthew-Wood syndrome caused by STRA6 mutations, oculofaciocardiodental syndrome and Lenz microphthalmia caused by BCOR mutations, Microphthalmia Linear Skin pigmentation syndrome caused by HCCS mutations, Anophthalmia, pituitary abnormalities, polysyndactyly caused by BMP4 mutations and Waardenburg anophthalmia caused by mutations in SMOC1. In addition, we briefly discuss the ocular and extraocular phenotypes associated with several other important eye developmental genes, including GDF6, VSX2, RAX, SHH, SIX6 and PAX6. PMID:22005280

  19. The character of abnormalities found in eye development of quail embruos exposed under space flight conditions

    NASA Astrophysics Data System (ADS)

    Grigoryan, E.; Dadheva, O.; Polinskaya, V.; Guryeva, T.

    The avian embryonic eye is used as a model system for studies on the environmental effects on central nervous system development. Here we present results of qualitative investigation of the eye development in quail embryos incubated in micro-"g" environment. In this study we used eyes of Japanese quail (Coturnix coturnix Japonica) embryos "flown" onboard biosatellite Kosmos-1129 and on Mir station within the framework of Mir-NASA Program. Eyes obtained from embryos ranging in age from 3-12 days (E3-E12) were prepared histologically and compared with those of the synchronous and laboratory gound controls. Ther most careful consideration was given to finding and analysis of eye developmental abnormalities. Then they were compared with those already described by experimental teratology for birds and mammals. At the stage of the "eye cup" (E3) we found the case of invalid formation of the inner retina. The latter was represented by disorganized neuroblasts occupying whole posterior chamber of the eye. On the 7th day of quail eye development, at the period of cellular growth activation some cases of small eyes with many folds of overgrowing neural and pigmented retinal layers were detected. In retinal folds of these eyes the normal layering was disturbed as well as the formation of aqueous body and pecten oculi. At this time point the changes were also found in the anterior part of the eye. The peculiarities came out of the bigger width of the cornea and separation of its layers, but were found in synchronous control as well. Few embryos of E10 had also eyes with the abnormities described for E7 but this time they were more vivid because of the completion of eye tissue differentiation. At the stage E12 we found the case evaluated as microphthalmia attending by overgrowth of anterior pigmented tissues - iris and ciliary body attached with the cornea. Most, but not all, of abnormalities we found in eye morphogeneses belonged to the birds "flown" aboard Kosmos- 1129 and

  20. Betalain: a particular class of antioxidant pigment.

    PubMed

    El Gharras, Hasna

    2011-10-01

    We have analyzed the stability of betalains in juices prepared from Moroccan yellow cactus pears (Opuntia ficus indica (L.) Mill.) as a function of temperature and pH. The experiments were carried out at temperatures ranging from 80 to 100 degrees C with juices at pH 3.5, 5 and 6.5. The degree of pigment retention decreased when the temperature increased. The degradation constant rates were determined for thermal degradation rates of pseudo-first order. The Arrhenius plot obtained for the degradation of betaxanthin from the yellow fruits was not linear. Regardless of the temperature of treatment, the lowest degradation was obtained for pH 5. When some stabilizers were tested for the protection of pigments, the results showed that ascorbic acid was a better protective agent at pH 3.5, increasing the protection by 40%. The inhibitive action of betalain pigments extracted from cactus pears towards corrosion of stainless steel in phosphoric acid was investigated using electrochemical polarization and electrochemical impedance spectroscopy (EIS) methods. It was found that the presence of natural pigments reduces the corrosion rate of the tested metal, especially on addition of the red pigments (97%). The inhibition efficiency increases as the pigment concentration of extracts increases. It was also found that the pigments tested act as mixed inhibitors. The inhibitive action of the extracts is discussed in term of adsorption and that such adsorption follows a Langmuir adsorption isotherm. The calculated values of the free energy of adsorption indicated that the adsorption process is spontaneous. PMID:22164774

  1. The injured eye

    PubMed Central

    Scott, Robert

    2011-01-01

    Eye injuries come at a high cost to society and are avoidable. Ocular blast injuries can be primary, from the blast wave itself; secondary, from fragments carried by the blast wind; tertiary; due to structural collapse or being thrown against a fixed object; or quaternary, from burns and indirect injuries. Ballistic eye protection significantly reduces the incidence of eye injuries and should be encouraged from an early stage in Military training. Management of an injured eye requires meticulous history taking, evaluation of vision that measures the acuity and if there is a relative pupillary defect as well as careful inspection of the eyes, under anaesthetic if necessary. A lateral canthotomy with cantholysis should be performed immediately if there is a sight-threatening retrobulbar haemorrhage. Systemic antibiotics should be prescribed if there is a suspected penetrating or perforating injury. A ruptured globe should be protected by an eye shield. Primary repair of ruptured globes should be performed in a timely fashion. Secondary procedures will often be required at a later date to achieve sight preservation. A poor initial visual acuity is not a guarantee of a poor final result. The final result can be predicted after approximately 3–4 weeks. Future research in eye injuries attempts to reduce scarring and neuronal damage as well as to promote photoreceptor rescue, using post-transcriptional inhibition of cell death pathways and vaccination to promote neural recovery. Where the sight has been lost sensory substitution of a picture from a spectacle mounted video camera to the touch receptors of the tongue can be used to achieve appreciation of the outside world. PMID:21149360

  2. What's in a Gene? Pseudoexfoliation Syndrome and Pigment Dispersion Syndrome in the Same Patient

    PubMed Central

    Pokrovskaya, Olya; O'Brien, Colm

    2016-01-01

    Pseudoexfoliation syndrome (PXS) and pigment dispersion syndrome (PDS) are two of the commonest disorders to produce secondary open-angle glaucoma through trabecular meshwork blockage. Each is a defined clinical entity, and while genetics likely play a significant role in the pathogenesis of both, the specific genes involved appear to be distinct. There is surprisingly little published in the literature regarding the coexistence of PDS and PXS in the same patient. We present the intriguing case of a patient who developed PDS in one eye and PXS in the other. This unusual case acts as a platform for an interesting discussion of the genomics of PXS and PDS. PMID:26933430

  3. Migration history, migration behavior and selectivity.

    PubMed

    Bailey, A J

    1993-01-01

    "A series of proportional hazards models are used to study the relationship between migration history and migration behavior for a sample of young adults from the [U.S.] National Longitudinal Survey of Youth. The results support the argument that migration is a selective process. College educated young adults have a greater hazard rate of making an initial migration but a lower hazard rate of re-migration, suggesting they have less need of corrective geographic behavior. Individuals who have moved two or more times are less responsive to national unemployment conditions than first time migrants. Migration is related to the timing of unemployment within a sojourn. The findings suggest that migrant stock is an important determinant of how labor markets function." PMID:12318324

  4. The molecular basis for the green-blue sensitivity shift in the rod visual pigments of the European eel.

    PubMed

    Archer, S; Hope, A; Partridge, J C

    1995-12-22

    When the European eel matures sexually and migrates back to deep sea breeding grounds the visual pigments in its rod photoreceptors change from being maximally sensitive to green light to being maximally sensitive to blue light. In part, this change in sensitivity is due to a change in the opsin component of the visual pigment molecule. We used hormone injection to induce these developmental changes in a group of eels and from these animals an opsin coding region was cloned and sequenced using cDNA made from retinal mRNA. From the retinae of hormone-injected eels and those not injected with hormones, distinct opsin mRNAs were isolated. These mRNAs encode two rod opsin proteins that are very similar but have significant amino acid substitutions in key positions that are likely to be involved in spectral tuning of the eel green and blue sensitive rod visual pigment molecules. PMID:8587887

  5. The ABCs of Eye Color in Tribolium castaneum: Orthologs of the Drosophila white, scarlet, and brown Genes

    PubMed Central

    Grubbs, Nathaniel; Haas, Sue; Beeman, Richard W.; Lorenzen, Marcé D.

    2015-01-01

    In Drosophila melanogaster, each of the three paralogous ABC transporters, White, Scarlet and Brown, is required for normal pigmentation of the compound eye. We have cloned the three orthologous genes from the beetle Tribolium castaneum. Conceptual translations of Tribolium white (Tcw), scarlet (Tcst), and brown (Tcbw) are 51, 48, and 32% identical to their respective Drosophila counterparts. We have identified loss-of-eye-pigment strains that bear mutations in Tcw and Tcst: the Tcw gene in the ivory (i) strain carries a single-base transversion, which leads to an E → D amino-acid substitution in the highly conserved Walker B motif, while the Tcst gene in the pearl (p) strain has a deletion resulting in incorporation of a premature stop codon. In light of these findings, the mutant strains i and p are herein renamed whiteivory (wi) and scarletpearl (stp), respectively. In addition, RNA inhibition of Tcw and Tcst recapitulates the mutant phenotypes, confirming the roles of these genes in normal eye pigmentation, while RNA interference of Tcbw provides further evidence that it has no role in eye pigmentation in Tribolium. We also consider the evolutionary implications of our findings. PMID:25555987

  6. The ABCs of eye color in Tribolium castaneum: orthologs of the Drosophila white, scarlet, and brown Genes.

    PubMed

    Grubbs, Nathaniel; Haas, Sue; Beeman, Richard W; Lorenzen, Marcé D

    2015-03-01

    In Drosophila melanogaster, each of the three paralogous ABC transporters, White, Scarlet and Brown, is required for normal pigmentation of the compound eye. We have cloned the three orthologous genes from the beetle Tribolium castaneum. Conceptual translations of Tribolium white (Tcw), scarlet (Tcst), and brown (Tcbw) are 51, 48, and 32% identical to their respective Drosophila counterparts. We have identified loss-of-eye-pigment strains that bear mutations in Tcw and Tcst: the Tcw gene in the ivory (i) strain carries a single-base transversion, which leads to an E → D amino-acid substitution in the highly conserved Walker B motif, while the Tcst gene in the pearl (p) strain has a deletion resulting in incorporation of a premature stop codon. In light of these findings, the mutant strains i and p are herein renamed white(ivory) (w(i)) and scarlet(pearl) (st(p)), respectively. In addition, RNA inhibition of Tcw and Tcst recapitulates the mutant phenotypes, confirming the roles of these genes in normal eye pigmentation, while RNA interference of Tcbw provides further evidence that it has no role in eye pigmentation in Tribolium. We also consider the evolutionary implications of our findings. PMID:25555987

  7. Prevention of cataracts in pink-eyed RCS rats by dark rearing.

    PubMed

    O'Keefe, T L; Hess, H H; Zigler, J S; Kuwabara, T; Knapka, J J

    1990-11-01

    Royal College of Surgeons rats have hereditary retinal degeneration and associated posterior subcapsular opacities (PSO) of the lens, detectable by slitlamp at 7-8 postnatal weeks in both pink- and black-eyed rats. The retinal degeneration is intensified by light, especially in pink-eyed rats. A fourth of pink-eyed rats developed mature cataracts by 9-12 months of age, but black-eyed rats whose retinas are protected from light by pigmented irises and pigment epithelium rarely have mature cataracts (3% or less), indicating light may be a factor in cataractogenesis. Prior work had shown that dark rearing reduced the rate of retinal degeneration in pink- but not black-eyed rats, but cataracts were not studied. In the present work, pregnant pink-eyed females were placed in a darkroom 1 week before parturition. Pups were removed over intervals at 20-85 postnatal days for: (a) microscopic study of fresh lenses and of fixed, stained retina and lens, and (b) counts of cells mm-2 of the web-like vitreous cortex after it had been dissected free. The macrophage-like cells are a quantitative index of immune reaction to retinal damage. At 50-53 postnatal days, in pink-eyed cyclic light reared RCS, the mean number of macrophages was 4.6-fold that in congenic controls, but in those that were dark reared it was only 1.4-fold. This was less than the increase in cyclic light reared black-eyed RCS (2.3-fold that in congenic black-eyed controls). Total absence of light reduced retinal degeneration and the number of macrophages, and prevented PSO detectable microscopically.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2249726

  8. Maya blue: a clay-organic pigment?

    PubMed

    Van Olphen, H

    1966-11-01

    Maya Blue, a pigment used by the Mayas in Yucatan, is remarkably stable: the color is not destroyed by hot concentrated mineral acids or by heating to about 250 degrees C. The principal constituent is the colorless mineral attapulgite. It is proposed that the pigment is an adsorption complex of attapulgite and natural indigo; a synthetic equivalent may be prepared from attapulgite and either indoxylester or indigo, or by applying the vat-dyeing technique, with reduced indigo.The low dye content of the pigment (less than 0.5 percent) indicates that the dye is absorbed only on the external surfaces of the attapulgite particles and not throughout the channels in their structures. The complex as such is not stable to acids, but the stability displayed by Maya Blue is achieved simply by heating the complex to from 75 degrees to 150 degrees C for several days. An analogous stable pigment can be prepared from sepiolite and indigo. No stable pigments could be prepared from clays with platelike structures or from zeolites. PMID:17778806

  9. Recreating a functional ancestral archosaur visual pigment.

    PubMed

    Chang, Belinda S W; Jönsson, Karolina; Kazmi, Manija A; Donoghue, Michael J; Sakmar, Thomas P

    2002-09-01

    The ancestors of the archosaurs, a major branch of the diapsid reptiles, originated more than 240 MYA near the dawn of the Triassic Period. We used maximum likelihood phylogenetic ancestral reconstruction methods and explored different models of evolution for inferring the amino acid sequence of a putative ancestral archosaur visual pigment. Three different types of maximum likelihood models were used: nucleotide-based, amino acid-based, and codon-based models. Where possible, within each type of model, likelihood ratio tests were used to determine which model best fit the data. Ancestral reconstructions of the ancestral archosaur node using the best-fitting models of each type were found to be in agreement, except for three amino acid residues at which one reconstruction differed from the other two. To determine if these ancestral pigments would be functionally active, the corresponding genes were chemically synthesized and then expressed in a mammalian cell line in tissue culture. The expressed artificial genes were all found to bind to 11-cis-retinal to yield stable photoactive pigments with lambda(max) values of about 508 nm, which is slightly redshifted relative to that of extant vertebrate pigments. The ancestral archosaur pigments also activated the retinal G protein transducin, as measured in a fluorescence assay. Our results show that ancestral genes from ancient organisms can be reconstructed de novo and tested for function using a combination of phylogenetic and biochemical methods. PMID:12200476

  10. Pigments in avocado tissue and oil.

    PubMed

    Ashton, Ofelia B O; Wong, Marie; McGhie, Tony K; Vather, Rosheila; Wang, Yan; Requejo-Jackman, Cecilia; Ramankutty, Padmaja; Woolf, Allan B

    2006-12-27

    Pigments are important contributors to the appearance and healthful properties of both avocado fruits and the oils extracted from these fruits. This study determined carotenoid and chlorophyll pigment concentrations in the skin and three sections of the flesh (outer dark green, middle pale green, and inner yellow flesh-nearest the seed) and anthocyanin concentrations in the skin of Hass avocado during ripening at 20 degrees C. Pigments were extracted from frozen tissue with acetone and measured using high-performance liquid chromatography. Pigments were also measured in the oil extracted from freeze-dried tissue sections by an accelerated solvent extraction system using hexane. Carotenoids and chlorophylls identified in the skin, flesh, and oil were lutein, alpha-carotene, beta-carotene, neoxanthin, violaxanthin, zeaxanthin, antheraxanthin, chlorophylls a and b, and pheophytins a and b with the highest concentrations of all pigments in the skin. Chlorophyllides a and b were identified in the skin and flesh tissues only. As the fruit ripened and softened, the skin changed from green to purple/black, corresponding to changes in skin hue angle, and a concomitant increase in cyanidin 3-O-glucoside and the loss of chlorophyllide a. In flesh tissue, chroma and lightness values decreased with ripening, with no changes in hue angle. The levels of carotenoids and chlorophylls did not change significantly during ripening. As fruit ripened, the total chlorophyll level in the oil from the flesh sections remained constant but declined in the oil extracted from the skin. PMID:17177553

  11. Inadvertent polychlorinated biphenyls in commercial paint pigments.

    PubMed

    Hu, Dingfei; Hornbuckle, Keri C

    2010-04-15

    A polychlorinated biphenyl (PCB) that was not produced as part of the Aroclor mixtures banned in the 1980s was recently reported in air samples collected in Chicago, Philadelphia, the Arctic, and several sites around the Great Lakes. In Chicago, the congener 3,3'-dichlorobiphenyl or PCB11 was found to be the fifth most concentrated congener and ubiquitous throughout the city. The congener exhibited strong seasonal concentration trends that suggest volatilization of this compound from common outdoor surfaces. Due to these findings and also the compound's presence in waters that received waste from paint manufacturing facilities, we hypothesized that PCB11 may be present in current commercial paint. In this study we measured PCBs in paint sold on the current retail market. We tested 33 commercial paint pigments purchased from three local paint stores. The pigment samples were analyzed for all 209 PCB congeners using gas chromatography with tandem mass spectrometry (GC-MS/MS). More than 50 PCB congeners including several dioxin-like PCBs were detected, and the PCB profiles varied due to different types of pigments and different manufacturing processes. PCB congeners were detected in azo and phthalocyanine pigments which are commonly used in paint but also in inks, textiles, paper, cosmetics, leather, plastics, food and other materials. Our findings suggest several possible mechanisms for the inadvertent production of specific PCB congeners during the manufacturing of paint pigments. PMID:19957996

  12. Investigations of biomimetic light energy harvesting pigments

    SciTech Connect

    Van Patten, P.G.; Donohoe, R.J.; Lindsey, J.S.; Bocian, D.F.

    1998-12-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Nature uses chlorophyll and other porphyrinic pigments to capture and transfer light energy as a preliminary step in photosynthesis. The design of synthetic assemblies of light harvesting and energy directing pigments has been explored through synthesis and characterization of porphyrin oligomers. In this project, pigment electronic and vibrational structures have been explored by electrochemistry and dynamic and static optical measurements. Transient absorption data reveal energy transfer between pigments with lifetimes on the order of 20--200 picoseconds, while Raman data reveal that the basic porphyrin core structure is unperturbed relative to the individual monomer units. These two findings, along with an extensive series of experiments on the oxidized oligomers, reveal that coupling between the pigments is fundamentally weak, but sufficient to allow facile energy transfer as the predominant excited state process. Modeling of the expected quantum yields for energy transfer within a variety of arrays was accomplished, thereby providing a tool to guide synthetic goals.

  13. Positional cloning of a Bombyx pink-eyed white egg locus reveals the major role of cardinal in ommochrome synthesis.

    PubMed

    Osanai-Futahashi, M; Tatematsu, K-I; Futahashi, R; Narukawa, J; Takasu, Y; Kayukawa, T; Shinoda, T; Ishige, T; Yajima, S; Tamura, T; Yamamoto, K; Sezutsu, H

    2016-02-01

    Ommochromes are major insect pigments involved in coloration of compound eyes, eggs, epidermis and wings. In the silkworm Bombyx mori, adult compound eyes and eggs contain a mixture of the ommochrome pigments such as ommin and xanthommatin. Here, we identified the gene involved in ommochrome biosynthesis by positional cloning of B. mori egg and eye color mutant pink-eyed white egg (pe). The recessive homozygote of pe has bright red eyes and white or pale pink eggs instead of a normal dark coloration due to the decrease of dark ommochrome pigments. By genetic linkage analysis, we narrowed down the pe-linked region to ~258 kb, containing 17 predicted genes. RNA sequencing analyses showed that the expression of one candidate gene, the ortholog of Drosophila haem peroxidase cardinal, coincided with egg pigmentation timing, similar to other ommochrome-related genes such as Bm-scarlet and Bm-re. In two pe strains, a common missense mutation was found within a conserved motif of B. mori cardinal homolog (Bm-cardinal). RNA interference-mediated knockdown and transcription activator-like effector nuclease (TALEN)-mediated knockout of the Bm-cardinal gene produced the same phenotype as pe in terms of egg, adult eye and larval epidermis coloration. A complementation test of the pe mutant with the TALEN-mediated Bm-cardinal-deficient strain showed that the mutant phenotype could not be rescued, indicating that Bm-cardinal is responsible for pe. Moreover, knockdown of the cardinal homolog in Tribolium castaneum also induced red compound eyes. Our results indicate that cardinal plays a major role in ommochrome synthesis of holometabolous insects. PMID:26328757

  14. COMPU-EYE: a high resolution computational compound eye.

    PubMed

    Lee, Woong-Bi; Jang, Hwanchol; Park, Sangjun; Song, Young Min; Lee, Heung-No

    2016-02-01

    In nature, the compound eyes of arthropods have evolved towards a wide field of view (FOV), infinite depth of field and fast motion detection. However, compound eyes have inferior resolution when compared with the camera-type eyes of vertebrates, owing to inherent structural constraints such as the optical performance and the number of ommatidia. For resolution improvements, in this paper, we propose COMPUtational compound EYE (COMPU-EYE), a new design that increases acceptance angles and uses a modern digital signal processing (DSP) technique. We demonstrate that the proposed COMPU-EYE provides at least a four-fold improvement in resolution. PMID:26906778

  15. Artificial neural superposition eye.

    PubMed

    Brückner, Andreas; Duparré, Jacques; Dannberg, Peter; Bräuer, Andreas; Tünnermann, Andreas

    2007-09-17

    We propose an ultra-thin imaging system which is based on the neural superposition compound eye of insects. Multiple light sensitive pixels in the footprint of each lenslet of this multi-channel configuration enable the parallel imaging of the individual object points. Together with the digital superposition of related signals this multiple sampling enables advanced functionalities for artificial compound eyes. Using this technique, color imaging and a circumvention for the trade-off between resolution and sensitivity of ultra-compact camera devices have been demonstrated in this article. The optical design and layout of such a system is discussed in detail. Experimental results are shown which indicate the attractiveness of microoptical artificial compound eyes for applications in the field of machine vision, surveillance or automotive imaging. PMID:19547555

  16. Pigments which reflect infrared radiation from fire

    DOEpatents

    Berdahl, P.H.

    1998-09-22

    Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer ({micro}m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 {micro}m or, for cool smoky fires, about 2 {micro}m to about 16 {micro}m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 {micro}m to about 2 {micro}m and thin leafing aluminum flake pigments. 4 figs.

  17. Pigments which reflect infrared radiation from fire

    DOEpatents

    Berdahl, Paul H.

    1998-01-01

    Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer (.mu.m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 .mu.m or, for cool smoky fires, about 2 .mu.m to about 16 .mu.m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 .mu.m to about 2 .mu.m and thin leafing aluminum flake pigments.

  18. Photorefraction of the Eye

    NASA Astrophysics Data System (ADS)

    Colicchia, Giuseppe; Wiesner, Hartmut; Zollman, Dean

    2015-02-01

    Photorefraction is a method to easily estimate the refractive state of the eye. The principle of photorefraction involves projecting light into the eye during flash photography and then examining the paths of light that emerge from the pupil after scattering on the back portion of the interior of the eyeball (fundus). We will explain the optical principles underlying the method for eccentric photorefraction and describe how students can perform it using current digital cameras. Our purpose is not to diagnose refractive errors reliably, but to use devices popular among young people that, in combination with an important ophthalmic context, may be successful in improving students' interest for learning optical concepts.

  19. Optical modulation of transgene expression in retinal pigment epithelium

    NASA Astrophysics Data System (ADS)

    Palanker, D.; Lavinsky, D.; Chalberg, T.; Mandel, Y.; Huie, P.; Dalal, R.; Marmor, M.

    2013-03-01

    Over a million people in US alone are visually impaired due to the neovascular form of age-related macular degeneration (AMD). The current treatment is monthly intravitreal injections of a protein which inhibits Vascular Endothelial Growth Factor, thereby slowing progression of the disease. The immense financial and logistical burden of millions of intravitreal injections signifies an urgent need to develop more long-lasting and cost-effective treatments for this and other retinal diseases. Viral transfection of ocular cells allows creation of a "biofactory" that secretes therapeutic proteins. This technique has been proven successful in non-human primates, and is now being evaluated in clinical trials for wet AMD. However, there is a critical need to down-regulate gene expression in the case of total resolution of retinal condition, or if patient has adverse reaction to the trans-gene products. The site for genetic therapy of AMD and many other retinal diseases is the retinal pigment epithelium (RPE). We developed and tested in pigmented rabbits, an optical method to down-regulate transgene expression in RPE following vector delivery, without retinal damage. Microsecond exposures produced by a rapidly scanning laser vaporize melanosomes and destroy a predetermined fraction of the RPE cells selectively. RPE continuity is restored within days by migration and proliferation of adjacent RPE, but since the transgene is not integrated into the nucleus it is not replicated. Thus, the decrease in transgene expression can be precisely determined by the laser pattern density and further reduced by repeated treatment without affecting retinal structure and function.

  20. Optical coherence tomographic imaging of sub-retinal pigment epithelium lipid.

    PubMed

    Mukkamala, Sri Krishna; Costa, Rogerio A; Fung, Adrian; Sarraf, David; Gallego-Pinazo, Roberto; Freund, K Bailey

    2012-12-01

    OBJECTIVE To describe an optical coherence tomographic finding of layered hyperreflective bands beneath the retinal pigment epithelium (RPE), the so-called onion sign believed to represent lipid within a vascularized pigment epithelial detachment. METHODS This retrospective observational case series involved reviewing clinical histories of patients with the onion sign. Imaging studies analyzed included spectral-domain optical coherence tomography, color and red-free photographs, near infrared reflectance, fundus autofluorescence, and blue-light fundus autofluorescence. RESULTS A total of 22 eyes of 20 patients with sub-RPE hyperreflective bands were identified. There were 15 women and 5 men with a mean patient age of 76 years (range, 60-92 years). Snellen best-corrected visual acuities ranged from 20/25 to counting fingers, with a median of 20/80. Two patients had bilateral involvement, and 3 of 17 eyes had multifocal onion signs in the same eye. All eyes had neovascular age-related macular degeneration, with type 1 (sub-RPE) neovascularization. In all patients, the onion sign correlated with areas of yellow-gray exudates seen clinically that appeared bright on red-free and near infrared reflectance imaging. No specific fundus autofluorescence or blue-light fundus autofluorescence pattern was identified. CONCLUSIONS The onion sign refers to layered hyperreflective bands in the sub-RPE space usually associated with chronic exudation from type 1 neovascularization in patients with age-related macular degeneration. With an associated bright near infrared reflectance, these bands may correspond to lipid, collagen, or fibrin. Because the onion sign colocalizes to areas of exudation that are known to consist of lipoprotein, we propose that this finding may represent layers of precipitated lipid in the sub-RPE space. To our knowledge, this is the first report of lipid detected in the sub-RPE space on clinical examination. PMID:22892986

  1. Fine-resolution photoacoustic imaging of the eye

    NASA Astrophysics Data System (ADS)

    Silverman, Ronald H.; Kong, Fanting; Lloyd, Harriet O.; Chen, Y. C.

    2010-02-01

    Purpose: Ultrasound and optical coherence tomography (OCT) are widely used techniques for diagnostic imaging of the eye. OCT provides excellent resolution, but limited penetration. Ultrasound provides better penetration, but an order-of-magnitude poorer resolution than OCT. Photoacoustic imaging is relatively insensitive to scattering, and so offers a potential means to image deeper than OCT. Furthermore, photoacoustic imaging detects optical absorption, a parameter that is independent of that detected by conventional ultrasound or OCT. Our aim was to develop a photoacoustic system suitable for imaging the eye. Methods: We developed a prototype system utilizing a focused 20 MHz ultrasound probe with a central aperture through which optics were introduced. The prototype system produced 1-μJ, 5-nsec pulses at 532 or 1064 nm with a 20-μm spot size at a 500 Hz repetition rate. The photoacoustic probe was mounted onto computer-controlled linear stages and pulse-echo ultrasound and photoacoustic images obtained on ex vivo pig eyes and in vivo mouse eyes. Results: Lateral resolution was significantly improved by use of a laser spot size much smaller than the acoustic beamwidth. Photoacoustic signals were obtained primarily from melanin in ex vivo tissues and from melanin and hemoglobin in vivo. Image fusion allowed superposition of photoacoustic signals upon the anatomic features detected by conventional ultrasound. Conclusion: Photoacoustic imaging detects the presence of clinically relevant pigments, such as melanin and oxyand deoxy-hemoglobin, and, potentially, from other pathologic pigments occurring in disease conditions (tumors, nevii, macular degeneration). Fine-resolution photoacoustic data provides information not detected in current ophthalmic imaging modalities.

  2. Retinal Pigment Epithelial Cell Line Suppression of Phagolysosome Activation

    PubMed Central

    Taylor, AW; Dixit, S; Yu, J

    2015-01-01

    The eye is an immune privileged tissue with multiple mechanisms of immunosuppression to protect the light gathering tissues from the damage of inflammation. One of theses mechanisms involves retinal pigment epithelial cell suppression of phagosome activation in macrophages. The objective of this work is to determine if the human RPE cell line ARPE-19 is capable of suppressing the activation of the phagolysosome in macrophages in a manner similar to primary RPE. The conditioned media of RPE eyecups, sub-confluent, just confluent cultures, or established confluent cultures of human ARPE-19 cells were generated. These condition media were used to treat macrophages phagocytizing pHrodo bioparticles. After 24 hours incubation the macrophages were imaged by fluorescent microscopy, and fluorescence was measured. The fluorescent intensity is proportional to the amount of bioparticles phagocytized and are in an activated phagolysosome. The conditioned media of in situ mouse RPE eyecups significantly suppressed the activation of phagolysosome. The conditioned media from cultures of human ARPE-19 cells, grown to sub-confluence (50%) or grown to confluence had no effect on phagolysosome activation. In contrast, the conditioned media from established confluent cultures significantly suppressed phagolysosome activation. The neuropeptides alpha-MSH and NPY were depleted from the conditioned media of established confluent ARPE-19 cell cultures. This depleted conditioned media had diminished suppression of phagolysosome activation while promoting macrophage cell death. In addition, the condition media from cultures of ARPE-19 monolayers wounded with a bisecting scrape was diminished in suppressing phagolysosome activation. This technical report suggests that like primary RPE monolayers, established confluent cultures of ARPE-19 cells produce soluble factors that suppress the activation of macrophages, and can be used to study the molecular mechanisms of retinal immunobiology. In

  3. Mycosis fungoides presenting as pigmented purpuric dermatitis.

    PubMed

    Hanna, Shannon; Walsh, Noreen; D'Intino, Yolanda; Langley, Richard G B

    2006-01-01

    Mycosis fungoides, a cutaneous T-cell lymphoma, typically presents as indolent, progressive, and persistent erythematous patches or plaques with mild scaling and over time can evolve into tumor stage with tumor nodules. Other presentations include eczematous, psoriasiform, poikilodermatous, and hypopigmented patches. We report Mycosis fungoides in a 14-year-old boy presenting as pigmented purpuric dermatitis and review the relevant literature. This is a rare presentation of a condition that is uncommon in the pediatric population. In our patient, histologic features were typical of Mycosis fungoides presenting as pigmented purpuric dermatitis. The clinical features, pathology, molecular biology, and the relationship between these two entities are discussed. PMID:16918631

  4. Pseudoepitheliomatous Hyperplasia in a Red Pigment Tattoo

    PubMed Central

    Kazlouskaya, Viktoryia

    2015-01-01

    Red pigment tattoos are known to cause pseudoepitheliomatous hyperplasia in the skin, frequently simulating squamous cell carcinoma or keratoacanthoma. Herein, the authors present two additional cases of red pigment tattoo pseudoepitheliomatous hyperplasia in which they noted a lichenoid tissue reaction. They reviewed the previously published cases and observed a lichenoid reaction in the histopathological images similar to hypertrophic lichen planus. The authors suggest that these reactions might best be referred to as “lichenoid reaction with pseudoepitheliomatous hyperplasia” or “hypertrophic lichen planus-like reaction.” Accordingly, recognition of an inflammatory component may allow additional treatment options. PMID:26705448

  5. Green pigments of the Pompeian artists' palette

    NASA Astrophysics Data System (ADS)

    Aliatis, Irene; Bersani, Danilo; Campani, Elisa; Casoli, Antonella; Lottici, Pier Paolo; Mantovan, Silvia; Marino, Iari-Gabriel; Ospitali, Francesca

    2009-08-01

    Green colored samples on wall paintings and green powder from a pigment pot found in Pompeii area are investigated by micro-Raman, FT-IR and, for one sample, SEM-EDX. To obtain the green color, green earths and malachite were used, together with mixture of Egyptian blue and yellow ochre. The mineralogical identification of the green earths has been attempted through the comparison of the vibrational features, discriminating between celadonite and glauconite spectra. Traces of a modern synthetic pigment containing copper phthalocyanine were found in a fresco fragment.

  6. Glaucoma: Eye-to-Eye with Dr. Rachel Bishop

    MedlinePlus

    ... of this page please turn JavaScript on. Feature: Glaucoma Eye-to-Eye with Dr. Rachel Bishop Past ... nerves are pale and cupped—signs of advanced glaucoma. Yet the patient wasn't aware of any ...

  7. Eye evolution: two eyes can be better than one.

    PubMed

    Foster, Kenneth W

    2009-03-10

    The development of our eyes is owed in part to ancestral structures which functioned in phototaxis. With the origin of bilateral annelid larva, two eyes co-evolved with neurons to improve phototaxis performance. PMID:19278637

  8. In-vivo laser-induced bubbles in the primate eye with femtosecond pulses

    NASA Astrophysics Data System (ADS)

    Cain, Clarence P.; DiCarlo, Cheryl D.; Noojin, Gary D.; Amnotte, Rodney E.; Rockwell, Benjamin A.; Roach, William P.

    1996-05-01

    Threshold measurements for laser-induced breakdown (LIB) and bubble generation for femtosecond laser pulsewidths have been made in vivo for rhesus monkey eyes. These LIB thresholds are compared with model-predicted thresholds for water and minimum visible lesion thresholds in Dutch Belted rabbit and rhesus monkey eyes. LIB thresholds in biological materials including vitreous, normal saline, tap water, and ultrapure water have been measured and reported using an artificial eye. We have recorded on video the first LIB causing bubble formation in any eye in vivo using albino rabbit eyes, pigmented rabbit eyes, and rhesus monkey eyes. External optics were used to focus the image within the vitreous and the bubbles generated were clearly formed anterior to the retina within the vitreous humor. The length of time that the bubbles are visible depends on the pulse energy delivered and may last for several seconds. However, for pulse energies near thresholds, the bubbles have a very short lifetime and may be seen on the video for only one frame. The plasma formation at the breakdown site acts as a limiting mechanism for energy transmission and may explain why high-energy femtosecond pulses at energies up to 100 microjoules sometimes do not cause severe damage to the retina. This fact may also explain why it is so difficult to product hemmorrhagic lesions in either the rabbit or primate eye with 100-femtosecond laser pulses.

  9. Pursuit Eye Movements

    NASA Technical Reports Server (NTRS)

    Krauzlis, Rich; Stone, Leland; Null, Cynthia H. (Technical Monitor)

    1998-01-01

    When viewing objects, primates use a combination of saccadic and pursuit eye movements to stabilize the retinal image of the object of regard within the high-acuity region near the fovea. Although these movements involve widespread regions of the nervous system, they mix seamlessly in normal behavior. Saccades are discrete movements that quickly direct the eyes toward a visual target, thereby translating the image of the target from an eccentric retinal location to the fovea. In contrast, pursuit is a continuous movement that slowly rotates the eyes to compensate for the motion of the visual target, minimizing the blur that can compromise visual acuity. While other mammalian species can generate smooth optokinetic eye movements - which track the motion of the entire visual surround - only primates can smoothly pursue a single small element within a complex visual scene, regardless of the motion elsewhere on the retina. This ability likely reflects the greater ability of primates to segment the visual scene, to identify individual visual objects, and to select a target of interest.

  10. Through Our Eyes

    ERIC Educational Resources Information Center

    Narva, Sara

    2009-01-01

    Through Our Eyes was a multimedia performance created in collaboration with the author's five modern dance students. Through video, sound, and dance, the piece shows some ways race has affected their lives. The author did not set out at the beginning of the semester to make this project in her dance class. It was born out of a hard conversation,…

  11. The Eyes Have It.

    ERIC Educational Resources Information Center

    Walsh, Janet

    1982-01-01

    Discusses the health hazards of working with the visual display systems of computers, in particular the eye problems associated with long-term use of video display terminals. Excerpts from and ordering information for the National Institute for Occupational Safety and Health report on such hazards are included. (JJD)

  12. The Eyes Have It

    NASA Technical Reports Server (NTRS)

    1999-01-01

    NASA'S Ames Research Center contracted with SRI international to contract a device that would be able to anticipate, track, and monitor involuntary ocular movement horizontally, vertically, and with respect to depth-of-field. This development helped research institutions to understand the eye. The Eyetracker, manufactured and distributed by Forward Optical Technologies, Inc. is now used in the clinical/medical field.

  13. Through Students' Eyes.

    ERIC Educational Resources Information Center

    McLean-Donaldson, Karen B.

    1994-01-01

    Identifies how students perceive racism and its effects on student learning and whether antiracist/multicultural arts (ARMA) curricula can empower students to address racism in schools. Results show racism, through students' eyes, damages learning, attitudes, and behavior. ARMA positively effected students' ability to confront racism within their…

  14. Administering Eye Medications.

    ERIC Educational Resources Information Center

    Morris, Sara; Michael, Nancy, Ed.

    This module on administering eye medications is intended for use in inservice or continuing education programs for persons who administer medications in long-term care facilities. Instructor information, including teaching suggestions, and a listing of recommended audiovisual materials and their sources appear first. A brief discussion follows of…

  15. Red or uncomfortable eye.

    PubMed Central

    Davey, C.; Hurwitz, B.

    1992-01-01

    1. A red, uncomfortable eye may be accompanied by other symptoms such as blurred, decreased, or double vision, haloes, photophobia, pain or discharge. 2. A careful history and brief systematic examination will sort out most problems. 3. Examine eyelids, the conjunctivae and corneas. Checking visual acuity is often important. 4. The most common underlying causes can usually be managed within general practice, though a few patients will require urgent eye assessment, or routine referral to ophthalmic outpatients. 5. The following are typical eye problems which require urgent referral: History of pain as opposed to discomfort, Trauma including foreign bodies, chemicals and suspected penetrating injury, Unexplained drop in visual acuity of two lines or more in a painful eye. Specific conditions: preseptal cellulitis, herpes simplex ulcer, scleritis, orbital cellulitis, herpes zoster, bacterial corneal ulcer, dacryocystitis. 6. The following are typical problems which may require routine referral: Persistence of the problem not relieved by simple measures, Recurrent disorders of uncertain diagnosis, Eyelid swelling such as chalazion, cysts, basal cell carcinoma, Gradual loss of vision, for example cataract, macular degeneration. PMID:1345157

  16. Diabetes - eye care

    MedlinePlus

    ... blurred vision is caused by having too much sugar and water in the lens of the eye, which is in front of the retina. Control your blood pressure . Blood pressure less than 130/80 is a ... sugar - self-care Diabetes - preventing heart attack and stroke ...

  17. Eye of the Beholder

    ERIC Educational Resources Information Center

    Rogers, Michael

    2010-01-01

    Art, like beauty, as the adage goes, is in the eye of the beholder. Art also is a living, breathing thing that evolves over time, so what is considered "art" is ever changing--how many of the great artists whose works today sell for fortunes were failures during their lifetime? The 20th century unknowingly gave birth to new variations of art that…

  18. Eyes for Learning

    ERIC Educational Resources Information Center

    Orfield, Antonia

    2008-01-01

    Vision is the dominant sense, and the eyes are connected with almost every other part of the brain. If the vision system is poorly developed, children trying to learn suffer. Without good up close vision, students are handicapped even if no one knows or suspects it--they may not even know it themselves. Students do not know that the way they see…

  19. Common eye emergencies.

    PubMed

    Gelston, Christopher D

    2013-10-15

    Ocular emergencies such as retinal detachments, mechanical globe injuries, and chemical injuries can cause permanent vision loss if they are not recognized and treated promptly. Family physicians should be familiar with the signs and symptoms associated with each condition, and be able to perform a basic eye examination to assess the situation. The assessment includes measurement of visual acuity, pupillary examination, visual field testing, slit lamp or penlight examination of the anterior segment of the eye, and direct funduscopic examination. Patients with symptomatic floaters and flashing lights require a dilated fundoscopic examination and prompt referral to an ophthalmologist for evaluation of a retinal tear or detachment. A globe laceration or rupture should be suspected in patients with a recent history of trauma from a blunt or penetrating object. Prophylactic oral antibiotics can be administered after a globe injury to prevent endophthalmitis, and the eye should be covered with a metal shield until evaluation by an ophthalmologist. Chemical injuries require immediate irrigation of the eye to neutralize the pH of the ocular surface. PMID:24364572

  20. Pigment oligomers as natural and artificial photosynthetic antennas

    SciTech Connect

    Blankenship, R.E.

    1996-12-31

    Green photosynthetic bacteria contain antenna complexes known as chlorosomes. These complexes are appressed to the cytoplasmic side of the inner cell membrane and function to absorb light and transfer the energy to the photochemical reaction center, where photochemical energy storage takes place. Chlorosomes differ from all other known photosynthetic antenna complexes in that the geometrical arrangement of pigments is determined primarily by pigment-pigment interactions instead of pigment-protein interactions. The bacteriochlorophyll c, d or e pigments found in chlorosomes form large oligomers with characteristic spectral properties significantly perturbed from those exhibited by monomeric pigments. Because of their close spatial interaction, the pigments are thought to be strongly coupled electronically, and many of the optical properties result from exciton interactions. This presentation will summarize existing knowledge on the chemical composition and properties of chlorosomes, the evidence for the oligomeric nature of chlorosome pigment organization and proposed structures for the oligomers, and the kinetics and mechanisms of energy transfer in chlorosomes.

  1. Separation of Chloroplast Pigments Using Reverse Phase Chromatography.

    ERIC Educational Resources Information Center

    Reese, R. Neil

    1997-01-01

    Presents a protocol that uses reverse phase chromatography for the separation of chloroplast pigments. Provides a simple and relatively safe procedure for use in teaching laboratories. Discusses pigment extraction, chromatography, results, and advantages of the process. (JRH)

  2. Defining the proteome of human iris, ciliary body, retinal pigment epithelium, and choroid.

    PubMed

    Zhang, Pingbo; Kirby, David; Dufresne, Craig; Chen, Yan; Turner, Randi; Ferri, Sara; Edward, Deepak P; Van Eyk, Jennifer E; Semba, Richard D

    2016-04-01

    The iris is a fine structure that controls the amount of light that enters the eye. The ciliary body controls the shape of the lens and produces aqueous humor. The retinal pigment epithelium and choroid (RPE/choroid) are essential in supporting the retina and absorbing light energy that enters the eye. Proteins were extracted from iris, ciliary body, and RPE/choroid tissues of eyes from five individuals and fractionated using SDS-PAGE. After in-gel digestion, peptides were analyzed using LC-MS/MS on an Orbitrap Elite mass spectrometer. In iris, ciliary body, and RPE/choroid, we identified 2959, 2867, and 2755 nonredundant proteins with peptide and protein false-positive rates of <0.1% and <1%, respectively. Forty-three unambiguous protein isoforms were identified in iris, ciliary body, and RPE/choroid. Four "missing proteins" were identified in ciliary body based on ≥2 proteotypic peptides. The mass spectrometric proteome database of the human iris, ciliary body, and RPE/choroid may serve as a valuable resource for future investigations of the eye in health and disease. The MS proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifiers PXD001424 and PXD002194. PMID:26834087

  3. Interactions between HERC2, OCA2 and MC1R may influence human pigmentation phenotype.

    PubMed

    Branicki, Wojciech; Brudnik, Urszula; Wojas-Pelc, Anna

    2009-03-01

    Human pigmentation is a polygenic trait which may be shaped by different kinds of gene-gene interactions. Recent studies have revealed that interactive effects between HERC2 and OCA2 may be responsible for blue eye colour determination in humans. Here we performed a population association study, examining important polymorphisms within the HERC2 and OCA2 genes. Furthermore, pooling these results with genotyping data for MC1R, ASIP and SLC45A2 obtained for the same population sample we also analysed potential genetic interactions affecting variation in eye, hair and skin colour. Our results confirmed the association of HERC2 rs12913832 with eye colour and showed that this SNP is also significantly associated with skin and hair colouration. It is also concluded that OCA2 rs1800407 is independently associated with eye colour. Finally, using various approaches we were able to show that there is an interaction between MC1R and HERC2 in determination of skin and hair colour in the studied population sample. PMID:19208107

  4. Simple Solutions for Dry Eye

    MedlinePlus

    ... are more concentrated in the tear film of dry eye patients. In hot weather, sleep with the windows shut and keep cool with air conditioning. • Dry eye patients often develop or aggravate allergies. An ...

  5. Infographic on the Aging Eye

    MedlinePlus

    ... retina. Dry eye Low vision Damage to the optic nerve. Eyes do not make enough tears. Difficulty ... retina that can be seen through undilated pupil. OPTIC NERVE RAY OF LIGHT PUPIL RETINA Portion of ...

  6. Recognizing and Treating Eye Injuries

    MedlinePlus

    ... and seek medical attention. In case of a chemical burn to the eye: Immediately flush the eye ... Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For ...

  7. Medicare Benefits and Your Eyes

    MedlinePlus

    ... Eye Health Report Reports and External Resources The Cost of Vision Problems The Future of Vision Vision Problems in the U.S. Healthy Eyes Education Series Online Training and Certification Patient Education Materials ...

  8. Dietary Sources of Lutein and Zeaxanthin Carotenoids and Their Role in Eye Health

    PubMed Central

    Abdel-Aal, El-Sayed M.; Akhtar, Humayoun; Zaheer, Khalid; Ali, Rashida

    2013-01-01

    The eye is a major sensory organ that requires special care for a healthy and productive lifestyle. Numerous studies have identified lutein and zeaxanthin to be essential components for eye health. Lutein and zeaxanthin are carotenoid pigments that impart yellow or orange color to various common foods such as cantaloupe, pasta, corn, carrots, orange/yellow peppers, fish, salmon and eggs. Their role in human health, in particular the health of the eye, is well established from epidemiological, clinical and interventional studies. They constitute the main pigments found in the yellow spot of the human retina which protect the macula from damage by blue light, improve visual acuity and scavenge harmful reactive oxygen species. They have also been linked with reduced risk of age-related macular degeneration (AMD) and cataracts. Research over the past decade has focused on the development of carotenoid-rich foods to boost their intake especially in the elderly population. The aim of this article is to review recent scientific evidences supporting the benefits of lutein and zexanthin in preventing the onset of two major age-related eye diseases with diets rich in these carotenoids. The review also lists major dietary sources of lutein and zeaxanthin and refers to newly developed foods, daily intake, bioavailability and physiological effects in relation to eye health. Examples of the newly developed high-lutein functional foods are also underlined. PMID:23571649

  9. Gene-gene interactions contribute to eye colour variation in humans.

    PubMed

    Pośpiech, Ewelina; Draus-Barini, Jolanta; Kupiec, Tomasz; Wojas-Pelc, Anna; Branicki, Wojciech

    2011-06-01

    Prediction of phenotypes from genetic data is considered to be the first practical application of data gained from association studies, with potential importance for medicine and the forensic sciences. Multiple genes and polymorphisms have been found to be associated with variation in human pigmentation. Their analysis enables prediction of blue and brown eye colour with a reasonably high accuracy. More accurate prediction, especially in the case of intermediate eye colours, may require better understanding of gene-gene interactions affecting this polygenic trait. Using multifactor dimensionality reduction and logistic regression methods, a study of gene-gene interactions was conducted based on variation in 11 known pigmentation genes examined in a cohort of 718 individuals of European descent. The study revealed significant interactions of a redundant character between the HERC2 and OCA2 genes affecting determination of hazel eye colour and between HERC2 and SLC24A4 affecting determination of blue eye colour. Our research indicates interactive effects of a synergistic character between HERC2 and OCA2, and also provides evidence for a novel strong synergistic interaction between HERC2 and TYRP1, both affecting determination of green eye colour. PMID:21471978

  10. Xanthophylls and eye health of infants and adults.

    PubMed

    Moukarzel, Adib A; Bejjani, Riad A; Fares, Florence N

    2009-01-01

    Lutein and zeaxanthin are the only carotenoids present in the eye. They cannot be synthesized de novo and are specifically concentrated in the macula. They appear to have at least two major functions: to filter out blue light and thus prevent ensuing damages to the eye and to act as antioxidants. Infants are particularly at risk from both blue light and oxidative damage to eye tissues. Lutein is present in human milk but is not currently added to infant formulas. Fortifying formulae with lutein in order to match more closely human milk might help protect the infant's sensitive eyes. In adults, the exact pathogenesis of age-related maculopathy remains unknown. Light damage, inflammation, and the disruption of cellular processes by oxidative stress may play an important role in the degenerative process. Manipulation of intake of xanthophylls has been shown to augment macular pigment, therefore it is thought that carotenoid dietary supplements could prevent, delay, or modify the course of age-related maculopathy. However, definite evidence of the effect of carotenoids, the optimal doses to use, and the supplementation duration are still under investigation. PMID:20027805

  11. The Use of HPLC for the Characterization of Phytoplankton Pigments.

    PubMed

    Garrido, José L; Roy, Suzanne

    2015-01-01

    HPLC is still the technique of choice for the analysis and characterization of phytoplankton pigments. In this chapter we describe procedures for sample preparation and pigment extraction, and the use of octyl silica columns and pyridine-containing mobile phases to separate chlorophylls and carotenoids. The identification of pigments on the basis of their retention times and visible spectra, the preparation of pigment standards, and the quantitative analysis by either external or internal standard procedures are also described. PMID:26108510

  12. Migration and Socioeconomic Attainment.

    ERIC Educational Resources Information Center

    Wilson, Franklin D.

    Research among black and white males aged 18 to 54 investigated correlations between migration patterns and occupational attainment and earnings. Results indicated that: (1) the propensity to migrate is related to entrance into, exit from, and laterations in occupational careers; (2) there is a positive association between migration and…

  13. Migration and Adult Education

    ERIC Educational Resources Information Center

    Gois, William

    2007-01-01

    The objective of this paper is to highlight the role of adult education as a tool in addressing labour migration issues, specifically those concerning the protection of migrant workers' rights and the transformation of the impact of migration into positive holistic developmental gains. The view of labour migration as a means to forge the economic…

  14. Kinetics of Lipofuscin Formation in Aging Retinal Pigment Epithelium Cells

    NASA Astrophysics Data System (ADS)

    Family, Fereydoon; Mazzitello, K. I.; Arizmendi, C. M.; Grossniklaus, Hans E.

    2010-03-01

    Lipofuscin is a deposit that is formed over time by aggregation and clustering of incompletely degraded membrane material in various types of cells. Lipofuscin is made of free-radical-damaged protein and fat and is known to be present in age- related macular dgeneration (AMD), Alzheimer disease, and Parkinson disease. AMD is the leading cause of blindness in adults. The degradation of retinal pigment epithelium cells (RPE) through accumulation of lipsofuscin is considered a significant pathogenic factor in the development of AMD. We will present the results of a study of the kinetics of lipofuscin growth in RPE cells using Kinetic Monte Carlo simulations and scaling theory on a cluster aggregation model. The model captures the essential physics of lipofuscin growth in the cells. A remarkable feature is that small particles may be removed from the cells while the larger ones become fixed and grow by aggregation. We compare our results with the number of lipofuscin granules in eyes with early age-related degeneration.

  15. Retinal pigment epithelium transplantation: concepts, challenges, and future prospects

    PubMed Central

    Alexander, P; Thomson, H A J; Luff, A J; Lotery, A J

    2015-01-01

    The retinal pigment epithelium (RPE) is a single layer of cells that supports the light-sensitive photoreceptor cells that are essential for retinal function. Age-related macular degeneration (AMD) is a leading cause of visual impairment, and the primary pathogenic mechanism is thought to arise in the RPE layer. RPE cell structure and function are well understood, the cells are readily sustainable in laboratory culture and, unlike other cell types within the retina, RPE cells do not require synaptic connections to perform their role. These factors, together with the relative ease of outer retinal imaging, make RPE cells an attractive target for cell transplantation compared with other cell types in the retina or central nervous system. Seminal experiments in rats with an inherited RPE dystrophy have demonstrated that RPE transplantation can prevent photoreceptor loss and maintain visual function. This review provides an update on the progress made so far on RPE transplantation in human eyes, outlines potential sources of donor cells, and describes the technical and surgical challenges faced by the transplanting surgeon. Recent advances in the understanding of pluripotent stem cells, combined with novel surgical instrumentation, hold considerable promise, and support the concept of RPE transplantation as a regenerative strategy in AMD. PMID:26043704

  16. Retinal pigment epithelium transplantation: concepts, challenges, and future prospects.

    PubMed

    Alexander, P; Thomson, H A J; Luff, A J; Lotery, A J

    2015-08-01

    The retinal pigment epithelium (RPE) is a single layer of cells that supports the light-sensitive photoreceptor cells that are essential for retinal function. Age-related macular degeneration (AMD) is a leading cause of visual impairment, and the primary pathogenic mechanism is thought to arise in the RPE layer. RPE cell structure and function are well understood, the cells are readily sustainable in laboratory culture and, unlike other cell types within the retina, RPE cells do not require synaptic connections to perform their role. These factors, together with the relative ease of outer retinal imaging, make RPE cells an attractive target for cell transplantation compared with other cell types in the retina or central nervous system. Seminal experiments in rats with an inherited RPE dystrophy have demonstrated that RPE transplantation can prevent photoreceptor loss and maintain visual function. This review provides an update on the progress made so far on RPE transplantation in human eyes, outlines potential sources of donor cells, and describes the technical and surgical challenges faced by the transplanting surgeon. Recent advances in the understanding of pluripotent stem cells, combined with novel surgical instrumentation, hold considerable promise, and support the concept of RPE transplantation as a regenerative strategy in AMD. PMID:26043704

  17. Simple and objective method for routine detection of the macular pigment xanthophyll

    NASA Astrophysics Data System (ADS)

    Schweitzer, Dietrich; Jentsch, Susanne; Dawczynski, Jens; Hammer, Martin; Wolf-Schnurrbusch, Ute E. K.; Wolf, Sebastian

    2010-11-01

    A new simple method for two-dimensional determination of optical density of macular pigment xanthophyll (ODx) in clinical routine is based on a single blue-reflection fundus image. Individual different vignetting is corrected by a shading function. For its construction, nodes are automatically found in structureless image regions. The influence of stray light in elderly crystalline lenses is compensated by a correction function that depends on age. The reproducibility of parameters in a one-wavelength reflection method determined for three subjects (47, 61, and 78 years old) was: maxODx = 6.3%, meanODx = 4.6%, volume = 6%, and area = 6% already before stray-light correction. ODx was comparable in pseudophakic and in an eye with a crystalline lens of the same 11 subjects after stray-light correction. Significant correlation in ODx was found between the one-wavelength reflection method and the two-wavelength autofluorescence method for pseudophakic and cataract eyes of 19 patients suffering from dry age-related macular degeneration (AMD) (R2 = 0.855). In pseudophakic eyes, maxODx was significantly lower for dry AMD (n = 45) (ODx = 0.491+/-0.102 ODU) than in eyes with healthy fundus (n = 22) (ODx = 0.615+/-0.103 ODU) (p = 0.000033). Also in eyes with crystalline lens, maxODx was lower in AMD (n = 125) (ODx = 0.610+/-0.093 ODU) than in healthy subjects (n = 45) (ODx = 0.674+/-0.098 ODU) (p = 0.00019). No dependence on age was found in the pseudophakic eyes both of healthy subjects and AMD patients.

  18. The peripheral clock regulates human pigmentation.

    PubMed

    Hardman, Jonathan A; Tobin, Desmond J; Haslam, Iain S; Farjo, Nilofer; Farjo, Bessam; Al-Nuaimi, Yusur; Grimaldi, Benedetto; Paus, Ralf

    2015-04-01

    Although the regulation of pigmentation is well characterized, it remains unclear whether cell-autonomous controls regulate the cyclic on-off switching of pigmentation in the hair follicle (HF). As human HFs and epidermal melanocytes express clock genes and proteins, and given that core clock genes (PER1, BMAL1) modulate human HF cycling, we investigated whether peripheral clock activity influences human HF pigmentation. We found that silencing BMAL1 or PER1 in human HFs increased HF melanin content. Furthermore, tyrosinase expression and activity, as well as TYRP1 and TYRP2 mRNA levels, gp100 protein expression, melanocyte dendricity, and the number gp100+ HF melanocytes, were all significantly increased in BMAL1 and/or PER1-silenced HFs. BMAL1 or PER1 silencing also increased epidermal melanin content, gp100 protein expression, and tyrosinase activity in human skin. These effects reflect direct modulation of melanocytes, as BMAL1 and/or PER1 silencing in isolated melanocytes increased tyrosinase activity and TYRP1/2 expression. Mechanistically, BMAL1 knockdown reduces PER1 transcription, and PER1 silencing induces phosphorylation of the master regulator of melanogenesis, microphthalmia-associated transcription factor, thus stimulating human melanogenesis and melanocyte activity in situ and in vitro. Therefore, the molecular clock operates as a cell-autonomous modulator of human pigmentation and may be targeted for future therapeutic strategies. PMID:25310406

  19. "Dry-column" chromatography of plant pigments

    NASA Technical Reports Server (NTRS)

    Woeller, F. H.; Lehwalt, M. F.; Oyama, V. I.

    1973-01-01

    Separation of plant pigments which can be accomplished on thin-layer silica plates with mixture of petroleum ether, halocarbon, acetone, and polar solvent can be readily translated into dry-column technique that yields reproducible chromatograms after elution in fashion of liquid chromatography with fluorimeter as detector. Best solvent system was found to be mixture of petroleum ether, dichloromethane, acetone, and ethyl acetate.

  20. Retinal pigment epithelial hamartoma--unusual manifestations.

    PubMed Central

    Rosenberg, P. R.; Walsh, J. B.

    1984-01-01

    Hamartoma of the retinal pigment epithelium is an uncommon tumour of young adults. We have seen 2 patients with this clinical diagnosis, both with unusual manifestations. In one patient growth of the tumour was observed over a 5-year period. In the second patient arterial-arterial anastomoses were detected at a site distal to the tumour. Images PMID:6722077

  1. Genetic markers of pigmentation are novel risk loci for uveal melanoma.

    PubMed

    Ferguson, Robert; Vogelsang, Matjaz; Ucisik-Akkaya, Esma; Rai, Karan; Pilarski, Robert; Martinez, Carlos N; Rendleman, Justin; Kazlow, Esther; Nagdimov, Khagay; Osman, Iman; Klein, Robert J; Davidorf, Frederick H; Cebulla, Colleen M; Abdel-Rahman, Mohamed H; Kirchhoff, Tomas

    2016-01-01

    While the role of genetic risk factors in the etiology of uveal melanoma (UM) has been strongly suggested, the genetic susceptibility to UM is currently vastly unexplored. Due to shared epidemiological risk factors between cutaneous melanoma (CM) and UM, in this study we have selected 28 SNPs identified as risk variants in previous genome-wide association studies on CM or CM-related host phenotypes (such as pigmentation and eye color) and tested them for association with UM risk. By logistic regression analysis of 272 UM cases and 1782 controls using an additive model, we identified five variants significantly associated with UM risk, all passing adjustment for multiple testing. The three most significantly associated variants rs12913832 (OR = 0.529, 95% CI 0.415-0.673; p = 8.47E-08), rs1129038 (OR = 0.533, 95% CI 0.419-0.678; p = 1.19E-07) and rs916977 (OR = 0.465, 95% CI 0.339-0.637; p = 3.04E-07) are correlated (r(2) > 0.5) and map at 15q12 in the region of HERC2/OCA2, which determines eye-color in the human population. Our data provides first evidence that the genetic factors associated with pigmentation traits are risk loci of UM susceptibility. PMID:27499155

  2. Genetic markers of pigmentation are novel risk loci for uveal melanoma

    PubMed Central

    Ferguson, Robert; Vogelsang, Matjaz; Ucisik-Akkaya, Esma; Rai, Karan; Pilarski, Robert; Martinez, Carlos N.; Rendleman, Justin; Kazlow, Esther; Nagdimov, Khagay; Osman, Iman; Klein, Robert J.; Davidorf , Frederick H.; Cebulla, Colleen M.; Abdel-Rahman, Mohamed H.; Kirchhoff , Tomas

    2016-01-01

    While the role of genetic risk factors in the etiology of uveal melanoma (UM) has been strongly suggested, the genetic susceptibility to UM is currently vastly unexplored. Due to shared epidemiological risk factors between cutaneous melanoma (CM) and UM, in this study we have selected 28 SNPs identified as risk variants in previous genome-wide association studies on CM or CM-related host phenotypes (such as pigmentation and eye color) and tested them for association with UM risk. By logistic regression analysis of 272 UM cases and 1782 controls using an additive model, we identified five variants significantly associated with UM risk, all passing adjustment for multiple testing. The three most significantly associated variants rs12913832 (OR = 0.529, 95% CI 0.415–0.673; p = 8.47E-08), rs1129038 (OR = 0.533, 95% CI 0.419–0.678; p = 1.19E-07) and rs916977 (OR = 0.465, 95% CI 0.339–0.637; p = 3.04E-07) are correlated (r2 > 0.5) and map at 15q12 in the region of HERC2/OCA2, which determines eye-color in the human population. Our data provides first evidence that the genetic factors associated with pigmentation traits are risk loci of UM susceptibility. PMID:27499155

  3. Effect of Pseudomonas putida on Growth and Anthocyanin Pigment in Two Poinsettia (Euphorbia pulcherrima) Cultivars

    PubMed Central

    Zulueta-Rodriguez, Ramon; Cordoba-Matson, Miguel Victor; Hernandez-Montiel, Luis Guillermo; Murillo-Amador, Bernardo; Rueda-Puente, Edgar; Lara, Liliana

    2014-01-01

    Pseudomonas putida is plant growth promoting rhizobacteria (PGPR) that have the capacity to improve growth in plants. The purpose of this study was to determine growth and anthocyanin pigmentation of the bracts in two poinsettia Euphorbia pulcherrima cultivars (Prestige and Sonora Marble) using three strains of P. putida, as well as a mixture of the three (MIX). Comparison with the control group indicated for the most part that Prestige grew better than the Sonora Marble cultivars with the PGPR strains. Prestige with the MIX strain grew better compared to control for the number of cyathia (83 versus 70.4), volume of roots (45 versus 35 cm3), number of leaves (78 versus 58), and area of leaf (1,788 versus 1,331 cm2), except for the number of flowers (8.8 versus 11.6). To the naked eye, coloration of plants appeared identical in color compared to the control group. For all plants with P. putida strains, there was less anthocyanin pigment, but biomass was always greater with PGPR strains. Nevertheless, to the naked eye, the coloration of the plants appeared identical in color compared to the control group. This is the first study reporting the positive effects of P. putida rhizobacteria treatments on growth of poinsettia cultivars. PMID:25097888

  4. Effect of Pseudomonas putida on growth and anthocyanin pigment in two poinsettia (Euphorbia pulcherrima) cultivars.

    PubMed

    Zulueta-Rodriguez, Ramon; Cordoba-Matson, Miguel Victor; Hernandez-Montiel, Luis Guillermo; Murillo-Amador, Bernardo; Rueda-Puente, Edgar; Lara, Liliana

    2014-01-01

    Pseudomonas putida is plant growth promoting rhizobacteria (PGPR) that have the capacity to improve growth in plants. The purpose of this study was to determine growth and anthocyanin pigmentation of the bracts in two poinsettia Euphorbia pulcherrima cultivars (Prestige and Sonora Marble) using three strains of P. putida, as well as a mixture of the three (MIX). Comparison with the control group indicated for the most part that Prestige grew better than the Sonora Marble cultivars with the PGPR strains. Prestige with the MIX strain grew better compared to control for the number of cyathia (83 versus 70.4), volume of roots (45 versus 3  cm(3)), number of leaves (78 versus 58), and area of leaf (1,788 versus 1,331 cm(2)), except for the number of flowers (8.8 versus 11.6). To the naked eye, coloration of plants appeared identical in color compared to the control group. For all plants with P. putida strains, there was less anthocyanin pigment, but biomass was always greater with PGPR strains. Nevertheless, to the naked eye, the coloration of the plants appeared identical in color compared to the control group. This is the first study reporting the positive effects of P. putida rhizobacteria treatments on growth of poinsettia cultivars. PMID:25097888

  5. Production of a Sporulation Pigment by Streptomyces venezuelae

    PubMed Central

    Scribner, H. E.; Tang, Terry; Bradley, S. G.

    1973-01-01

    Streptomyces venezuelae S13 produced a pH-indicating sporulation pigment on a glucose-salts-agar medium consisting of glucose, KNO3, MgSO4, and Na2HPO4, pH 7. Pigmentation on this medium appeared to be closely associated with sporulation, which normally required 5 to 7 days at 30 C. The pigment was soluble in water as well as in a number of organic solvents. Butanol-extracted pigment exhibited absorption maxima at 430 and 520 nm at pH 3 and 12, respectively. Although many salts of organic acids and amino acids could replace glucose as the sole carbon source in basal salts-agar medium for growth and pigmentation, most sugars that were tested supported good growth but negligible pigmentation. Among the nitrogenous substances tested, KNO3 was most desirable for pigmentation. The organism did not exhibit any specific requirements for divalent cations with respect to growth and pigmentation. In the absence of MgSO4, however, glucose-salts-agar prepared by autoclaving all components together failed to support growth. The production of the sporulation pigment on glucose-salts-agar was comparable to that obtained on tomato paste-oatmeal-agar medium. Incorporation of partially purified pigment material into broth medium that did not normally support sporulation induced sporulation, and amino acid-salts-agar medium could induce vegetative mycelia to pigment when transferred from medium that did not support either pigmentation or sporulation. Images PMID:4577487

  6. Neurotized Congenital Melanocytic Nevus Resembling a Pigmented Neurofibroma

    PubMed Central

    Singh, Nidhi; Chandrashekar, Laxmisha; Kar, Rakhee; Sylvia, Mary Theresa; Thappa, Devinder Mohan

    2015-01-01

    Neurotized congenital melanocytic nevus and pigmented neurofibroma (PNF) are close mimics and pose a clinicopathological challenge. We present a case of pigmented hypertrichotic plaque over lumbosacral region and discuss the differential diagnosis and its clinical, histopathological and immunohistochemistry features which may aid in differentiation. We highlight the difficulties faced in differentiating neurotized congenital melanocytic nevus from pigmented neurofibroma. PMID:25657396

  7. The determination and optimization of (rutile) pigment particle size distributions

    NASA Technical Reports Server (NTRS)

    Richards, L. W.

    1972-01-01

    A light scattering particle size test which can be used with materials having a broad particle size distribution is described. This test is useful for pigments. The relation between the particle size distribution of a rutile pigment and its optical performance in a gray tint test at low pigment concentration is calculated and compared with experimental data.

  8. 21 CFR 73.3128 - Mica-based pearlescent pigments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Mica-based pearlescent pigments. 73.3128 Section... pigments. (a) Identity and specifications. The color additive is formed by depositing titanium or iron... pigments listed in paragraph (a) of this section may be used as a color additive in contact lenses...

  9. 21 CFR 73.350 - Mica-based pearlescent pigments.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Mica-based pearlescent pigments. 73.350 Section 73... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.350 Mica-based pearlescent pigments. (a... pearlescent pigments may contain only those diluents listed in this subpart as safe and suitable for use...

  10. 21 CFR 73.3128 - Mica-based pearlescent pigments.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Mica-based pearlescent pigments. 73.3128 Section... pigments. (a) Identity and specifications. The color additive is formed by depositing titanium or iron... pigments listed in paragraph (a) of this section may be used as a color additive in contact lenses...

  11. 21 CFR 73.350 - Mica-based pearlescent pigments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Mica-based pearlescent pigments. 73.350 Section 73... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.350 Mica-based pearlescent pigments. (a... pearlescent pigments may contain only those diluents listed in this subpart as safe and suitable for use...

  12. 21 CFR 73.1350 - Mica-based pearlescent pigments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Mica-based pearlescent pigments. 73.1350 Section... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1350 Mica-based pearlescent pigments. (a...-based pearlescent pigments may contain only those diluents listed in this subpart as safe and...

  13. 21 CFR 73.1350 - Mica-based pearlescent pigments.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Mica-based pearlescent pigments. 73.1350 Section... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1350 Mica-based pearlescent pigments. (a...-based pearlescent pigments may contain only those diluents listed in this subpart as safe and...

  14. FINE STRUCTURE OF THE EYE OF A CHAETOGNATH.

    PubMed

    EAKIN, R M; WESTFALL, J A

    1964-04-01

    Electron microscopy reveals a star-like pigment cell at the center of the eye of the arrow-worm, Sagitta scrippsae. Between the arms of the pigment cell are clusters of photoreceptor cell processes, each process consisting of: (1) a tubular segment containing longitudinally arranged microtubules about 500 A in diameter and 20 micro in length; (2) a remarkable conical body, composed of cords and large granules, situated at the base of the tubular segment; and (3) a connecting piece which, like that of rods and cones, connects the process with the sensory cell proper and through which runs a fibrillar apparatus consisting of nine peripheral double tubules. Beneath the connecting piece lies a typical centriole with a striated rootlet. The receptor cell process is deeply recessed into the sensory cell which may possess a corona of microvilli at its inner surface. A nerve fiber arises from the outer end of the cell and passes into the optic nerve. Additional features are some supporting cells, an external layer of flattened epithelial cells, and an over-all investment of basement membrane and thick fibrous capsule. The fine structure and function of these elements of the eye are discussed in relation to earlier studies with the light microscope. The ciliary nature of the photoreceptor cell process in S. scrippsae points to a probable evolutionary relationship of chaetognaths to echinoderms and chordates. PMID:14154485

  15. Experiments on a Model Eye

    ERIC Educational Resources Information Center

    Arell, Antti; Kolari, Samuli

    1978-01-01

    Explains a laboratory experiment dealing with the optical features of the human eye. Shows how to measure the magnification of the retina and the refractive anomaly of the eye could be used to measure the refractive power of the observer's eye. (GA)

  16. How the Human Eye Focuses.

    ERIC Educational Resources Information Center

    Koretz, Jane F.; Handelman, George H.

    1988-01-01

    Describes the decline in people's ability to focus their eyes as their age increases. Discusses probable causes of this effect including changes in the eye's geometry and biochemistry. Diagrammatically illustrates age related changes in the lens of the human eye. (CW)

  17. Eye Protection in Kansas Schools.

    ERIC Educational Resources Information Center

    Hay, Kenneth M.; And Others

    A law passed by a state legislature requires that students in industrial arts shops and science laboratories must wear eye protective devices. Explanatory material presents the text of the bill and guidelines for implementation, including--(1) types of eye hazards, (2) types of protective devices, (3) administrating eye safety equipment, (4)…

  18. LIMNOLOGICAL OPTOMETRY: EXAMINING EARTH'S EYE

    EPA Science Inventory

    In Thoreau's Walden, a lake is described as the landscape's most expressive feature and the earth's eye. Collectively, scientists are charged by society to assess, monitor, and remedy maladies of earth's eye in the same way optometrists maintain the health of the human eye. This ...

  19. The Project MACULA Retinal Pigment Epithelium Grading System for Histology and Optical Coherence Tomography in Age-Related Macular Degeneration

    PubMed Central

    Zanzottera, Emma C.; Messinger, Jeffrey D.; Ach, Thomas; Smith, R. Theodore; Freund, K. Bailey; Curcio, Christine A.

    2015-01-01

    Purpose. To seek pathways of retinal pigment epithelium (RPE) fate in age-related macular degeneration via a morphology grading system; provide nomenclature, visualization targets, and metrics for clinical imaging and model systems. Methods. Donor eyes with geographic atrophy (GA) or choroidal neovascularization (CNV) and one GA eye with previous clinical spectral-domain optical coherence tomography (SDOCT) imaging were processed for histology, photodocumented, and annotated at predefined locations. Retinal pigment epithelial cells contained spindle-shaped melanosomes, apposed a basal lamina or basal laminar deposit (BLamD), and exhibited recognizable morphologies. Thicknesses and unbiased estimates of frequencies were obtained. Results. In 13 GA eyes (449 locations), ‘Shedding,’ ‘Sloughed,’ and ‘Dissociated’ morphologies were abundant; 22.2% of atrophic locations had ‘Dissociated’ RPE. In 39 CNV eyes (1363 locations), 37.3% of locations with fibrovascular/fibrocellular scar had ‘Entombed’ RPE; ‘Sloughed,’ ‘Dissociated,’ and ‘Bilaminar’ morphologies were abundant. Of abnormal RPE, CNV and GA both had ∼35% ‘Sloughed’/‘Intraretinal,’ with more Intraretinal in CNV (9.5% vs. 1.8%). ‘Shedding’ cells associated with granule aggregations in BLamD. The RPE layer did not thin, and BLamD remained thick, with progression. Granule-containing material consistent with three morphologies correlated to SDOCT hyperreflective foci in the previously examined GA patient. Conclusions. Retinal pigment epithelium morphology indicates multiple pathways in GA and CNV. Atrophic/scarred areas have numerous cells capable of transcribing genes and generating imaging signals. Shed granule aggregates, possibly apoptotic, are visible in SDOCT, as are ‘Dissociated’ and ‘Sloughed’ cells. The significance of RPE phenotypes is addressable in longitudinal, high-resolution imaging in clinic populations. Data can motivate future molecular phenotyping

  20. Dimerization of visual pigments in vivo.

    PubMed

    Zhang, Tao; Cao, Li-Hui; Kumar, Sandeep; Enemchukwu, Nduka O; Zhang, Ning; Lambert, Alyssia; Zhao, Xuchen; Jones, Alex; Wang, Shixian; Dennis, Emily M; Fnu, Amrita; Ham, Sam; Rainier, Jon; Yau, King-Wai; Fu, Yingbin

    2016-08-01

    It is a deeply engrained notion that the visual pigment rhodopsin signals light as a monomer, even though many G protein-coupled receptors are now known to exist and function as dimers. Nonetheless, recent studies (albeit all in vitro) have suggested that rhodopsin and its chromophore-free apoprotein, R-opsin, may indeed exist as a homodimer in rod disk membranes. Given the overwhelmingly strong historical context, the crucial remaining question, therefore, is whether pigment dimerization truly exists naturally and what function this dimerization may serve. We addressed this question in vivo with a unique mouse line (S-opsin(+)Lrat(-/-)) expressing, transgenically, short-wavelength-sensitive cone opsin (S-opsin) in rods and also lacking chromophore to exploit the fact that cone opsins, but not R-opsin, require chromophore for proper folding and trafficking to the photoreceptor's outer segment. In R-opsin's absence, S-opsin in these transgenic rods without chromophore was mislocalized; in R-opsin's presence, however, S-opsin trafficked normally to the rod outer segment and produced functional S-pigment upon subsequent chromophore restoration. Introducing a competing R-opsin transmembrane helix H1 or helix H8 peptide, but not helix H4 or helix H5 peptide, into these transgenic rods caused mislocalization of R-opsin and S-opsin to the perinuclear endoplasmic reticulum. Importantly, a similar peptide-competition effect was observed even in WT rods. Our work provides convincing evidence for visual pigment dimerization in vivo under physiological conditions and for its role in pigment maturation and targeting. Our work raises new questions regarding a potential mechanistic role of dimerization in rhodopsin signaling. PMID:27462111

  1. [The theory of migration].

    PubMed

    Delbruck, C; Raffelhuschen, B

    1993-09-01

    "The present and expected migration flows in Europe require a detailed analysis of determinants and elements of migration decisions. This survey encompasses a view on classical--labor market and demand side oriented--theories, the more recent human capital approach as well as on migration under asymmetric information. Since these theories so far yield an unsatisfactory basis for description and forecasting of multilateral migration flows, a closer look at empirical methods of migration research is taken. Consequently, a description of possible policy oriented applications of the gravity model and the random utility approach, with their descriptive and normative characteristics, is given." (SUMMARY IN ENG) PMID:12319309

  2. What Happens After Treatment for Eye Cancer?

    MedlinePlus

    ... having eye cancer What happens after treatment for eye cancer? For many people with eye cancer, treatment ... manage them. Follow-up after treatment of uveal (eye) melanoma Your doctor will most likely want to ...

  3. What Is a Comprehensive Dilated Eye Exam?

    MedlinePlus

    ... su oculista What is a comprehensive dilated eye exam? You may think your eyes are healthy, but ... eye care professional for a comprehensive dilated eye exam is the only way to really be sure. ...

  4. [Conservative treatment of dry eye].

    PubMed

    Hefner, J; Reinshagen, H

    2014-11-01

    The use of topic anti-inflammatory drugs has become very important in the treatment of dry eye disease. Besides the basic therapy including tear replacement, use of serum eye drops and mucolytic eye drops, the topical application of corticosteroids and cyclosporin A is more commonly used in moderate to severe forms of dry eye disease. The consistent treatment of Meibomian gland dysfunction as a frequent reason for evaporative dry eye is also of particular importance. Understanding the chronicity of the disease and long-term compliance are the essential for successful therapy of this widespread disease. PMID:25275793

  5. Eye movement abnormalities.

    PubMed

    Moncayo, Jorge; Bogousslavsky, Julien

    2012-01-01

    Generation and control of eye movements requires the participation of the cortex, basal ganglia, cerebellum and brainstem. The signals of this complex neural network finally converge on the ocular motoneurons of the brainstem. Infarct or hemorrhage at any level of the oculomotor system (though more frequent in the brain-stem) may give rise to a broad spectrum of eye movement abnormalities (EMAs). Consequently, neurologists and particularly stroke neurologists are routinely confronted with EMAs, some of which may be overlooked in the acute stroke setting and others that, when recognized, may have a high localizing value. The most complex EMAs are due to midbrain stroke. Horizontal gaze disorders, some of them manifesting unusual patterns, may occur in pontine stroke. Distinct varieties of nystagmus occur in cerebellar and medullary stroke. This review summarizes the most representative EMAs from the supratentorial level to the brainstem. PMID:22377853

  6. Nutrition and the eye.

    PubMed

    Congdon, N G; West, K P

    1999-12-01

    The topic "nutrition and the eye" cannot adequately be covered in a single review article; indeed, dozens of books and hundreds of articles have been written on the subject. This review concentrates on three areas in which specific nutrients are known or theorized to have a major impact on vision and the visual system: vitamin A deficiency; antioxidants and their proposed role in the prevention of age-related cataract and macular degeneration; and nutritional optic neuropathies, including those of the recent Cuban epidemic. In addition, this article touches on nutritional treatments that have been suggested for several less common eye diseases and, finally, considers several less prevalent conditions in which deficiency of or excess exposure to a particular nutrient has been associated with ocular pathology. PMID:10662253

  7. [The eye and cancer].

    PubMed

    Schalenbourg, Ann; Mantel, Irmela

    2015-12-16

    Cancer involves so rarely the eye that it may be recognized late. The most frequent primary intra-ocular tumours are retinoblastoma in small children and uveal melanoma in adults. Vision loss in systemic cancer has a varied differential diagnosis. Uveal metastases are most often associated with breast cancer, but can herald lung carcinoma. Masquerade syndrome looks like inflammation but represents the ocular involvement of primary CNS non-Hodgkin lymphoma. Systemic cancer drugs, as well as radiotherapy, can cause ocular toxicity, mostly at the retina. In the rare paraneoplastic syndromes, patient's cancer antibodies cross-react with retinal antigens, leading to severe vision loss. When cancer involves the eye, a fast referral into specialized care can significantly improve visual and vital prognosis. PMID:26852556

  8. Pioneers of eye movement research

    PubMed Central

    Wade, Nicholas J

    2010-01-01

    Recent advances in the technology affording eye movement recordings carry the risk of neglecting past achievements. Without the assistance of this modern armoury, great strides were made in describing the ways the eyes move. For Aristotle the fundamental features of eye movements were binocular, and he described the combined functions of the eyes. This was later given support using simple procedures like placing a finger over the eyelid of the closed eye and culminated in Hering's law of equal innervation. However, the overriding concern in the 19th century was with eye position rather than eye movements. Appreciating discontinuities of eye movements arose from studies of vertigo. The characteristics of nystagmus were recorded before those of saccades and fixations. Eye movements during reading were described by Hering and by Lamare in 1879; both used similar techniques of listening to sounds made during contractions of the extraocular muscles. Photographic records of eye movements during reading were made by Dodge early in the 20th century, and this stimulated research using a wider array of patterns. In the mid-20th century attention shifted to the stability of the eyes during fixation, with the emphasis on involuntary movements. The contributions of pioneers from Aristotle to Yarbus are outlined. PMID:23396982

  9. Eye preferences in captive chimpanzees.

    PubMed

    Braccini, Stephanie N; Lambeth, Susan P; Schapiro, Steven J; Fitch, W Tecumseh

    2012-09-01

    Over the last century, the issue of brain lateralization in primates has been extensively investigated and debated, yet no previous study has reported eye preference in great apes. This study examined eye preference in 45 captive chimpanzees (Pan troglodytes) in response to various stimuli. Eye preference was assessed when animals looked through a hole that only accommodated one eye at an empty box, a mirror, a picture of a dog, a rubber snake, food biscuits, bananas, a rubber duck, and a video camera. Main effects of stimulus type were found for direction of eye preference, number of looks, and looking duration, but not for strength of eye preference. A left-eye bias was found for viewing the rubber snake and a right-eye bias was found for viewing the bananas, supporting theories that emotional valence may affect lateralized behaviors. In addition, a significant shift in eye preference took place from the initial look to subsequent looks when viewing the snake. These results are not consistent with previous reports of human eye preference and may reflect lateralization differences for emotional processing. No relationship between eye preference and previously recorded hand preference was found. PMID:22733385

  10. Michelangelo's eye disease.

    PubMed

    Gallenga, P E; Neri, Giampiero; D'Anastasio, Ruggero; Pettorrossi, Vito Enrico; Alfieri, Emilio; Capasso, Luigi

    2012-06-01

    Charged by the Pope Julius II for painting the Cappella Sistina in Rome (between 1508 and 1512), Michelangelo worked in an elevated scaffolding, in an anomalous position with dyes (including poisoning lead salts) and solvents (such as toxic turpentine) dripping on his face and continuously inhaling, in a dim environment illuminated only with oil lamps and candles, as he described himself and sketched in a sonet addressed to Giovanni da Pistoia. In 1510 he began suffering from eye disease: the main symptom was the necessity to elevate the document he was reading up to the level of his eyes. This defect disappeared few months after he finished painting his masterpiece. We hypothesize that the Michelangelo's eyes disease was a form of acquired and transitory nystagmus induced by the many hours he spent in up gaze, with a skew deviation, a form of ocular tilt reaction resulting from the impairment of spatial sensitivity (inversion illusion) due to the persistence of the artist's head in a horizontal position, looking upward. PMID:22425178

  11. Schizophrenia and the eye

    PubMed Central

    Silverstein, Steven M.; Rosen, Richard

    2015-01-01

    Although visual processing impairments are common in schizophrenia, it is not clear to what extent these originate in the eye vs. the brain. This review highlights potential contributions, from the retina and other structures of the eye, tovisual processing impairments in schizophrenia and high-risk states. A second goal is to evaluate the status of retinal abnormalities as biomarkers for schizophrenia. The review was motivated by known retinal changes in other disorders (e.g., Parkinson's disease, multiple sclerosis), and their relationships to perceptual and cognitive impairments, and disease progression therein. The evidence reviewed suggests two major conclusions. One is that there are multiple structural and functional disturbances of the eye in schizophrenia, all of which could be factors in the visual disturbances of patients. These include retinal venule widening, retinal nerve fiber layer thinning, dopaminergic abnormalities, abnormal ouput of retinal cells as measured by electroretinography (ERG), maculopathies and retinopathies, cataracts, poor acuity, and strabismus. Some of these are likely to be illness-related, whereas others may be due to medication or comorbid conditions. The second conclusion is that certain retinal findings can serve as biomarkers of neural pathology, and disease progression, in schizophrenia. The strongest evidence for this to date involves findings of widened retinal venules, thinning of the retinal nerve fiber layer, and abnormal ERG amplitudes. These data suggest that a greater understanding of the contribution of retinal and other ocular pathology to the visual and cognitive disturbances of schizophrenia is warranted, and that retinal changes have untapped clinical utility. PMID:26345525

  12. Christoph Scheiner's eye studies.

    PubMed

    Daxecker, F

    1992-01-01

    Christoph Scheiner was born in 1573 or 1575. In 1595 he entered into the Order of the Jesuits; he died in 1650. In 1619 his book Oculus, dealing with the optics of the eye, appeared in Innsbruck. The invention of the telescope was of utmost importance for progress in astronomical and physical research. Scheiner himself built telescopes and discovered the sunspots. As a result, an unpleasant priority dispute with Galilei ensued. From 1624 onwards, Scheiner was in Rome, where his main work Rosa Ursina was published in 1630. A part of this book deals with the physiological optics of the eye as well. Some of his discoveries and experiments are taken from these two books: determination of the radius of curvature of the cornea, discovery of the nasal exit of the optic nerve, increase in the radius of curvature of the lens in case of accommodation, Scheiner's procedure (double images with ametropia), refractive indices of various parts of the eye, Scheiner's experiment. Without any doubt, Christoph Scheiner belongs to the foremost scientists of the first half of the 17th century. PMID:1473465

  13. Organization of the peripheral fly eye: the roles of Snail family transcription factors in peripheral retinal apoptosis.

    PubMed

    Lim, Hui-Ying; Tomlinson, Andrew

    2006-09-01

    The periphery of the fly eye contains a number of concentrically arranged cellular specializations that are induced by Wingless (Wg) signaling from the surrounding head capsule (HC). One of these is the pigment rim (PR), which is a thick layer of pigment cells that lies directly adjacent to the HC and completely circumscribes the rest of the retina. Many of the cells of the PR are derived from presumptive pigment cells that previously surrounded peripheral ommatidia that subsequently died. Here, we describe the Wg-elicited expression of Snail family transcription factors in the eye periphery that directs the ommatidial death and subsequent PR formation. These transcription factors are expressed only in a subset of the ommatidial cells not including the photoreceptors. Yet, the photoreceptors die and, thus, a non-autonomous death signal is released from the Snail-family-expressing cells that direct the death of the photoreceptors. In addition, Wg also elicits a similar peripheral expression of Notum, an enzyme that limits the extent of Wg signaling. Furthermore, we describe a later requirement for Snail family proteins in the 2 degrees and 3 degrees pigment cells throughout the main body of the eye. PMID:16914498

  14. A Regulatory Loop Involving PAX6, MITF, and WNT Signaling Controls Retinal Pigment Epithelium Development

    PubMed Central

    Bharti, Kapil; Gasper, Melanie; Ou, Jingxing; Brucato, Martha; Clore-Gronenborn, Katharina; Pickel, James; Arnheiter, Heinz

    2012-01-01

    The separation of the optic neuroepithelium into future retina and retinal pigment epithelium (RPE) is a critical event in early eye development in vertebrates. Here we show in mice that the transcription factor PAX6, well-known for its retina-promoting activity, also plays a crucial role in early pigment epithelium development. This role is seen, however, only in a background genetically sensitized by mutations in the pigment cell transcription factor MITF. In fact, a reduction in Pax6 gene dose exacerbates the RPE-to-retina transdifferentiation seen in embryos homozygous for an Mitf null allele, and it induces such a transdifferentiation in embryos that are either heterozygous for the Mitf null allele or homozygous for an RPE–specific hypomorphic Mitf allele generated by targeted mutation. Conversely, an increase in Pax6 gene dose interferes with transdifferentiation even in homozygous Mitf null embryos. Gene expression analyses show that, together with MITF or its paralog TFEC, PAX6 suppresses the expression of Fgf15 and Dkk3. Explant culture experiments indicate that a combination of FGF and DKK3 promote retina formation by inhibiting canonical WNT signaling and stimulating the expression of retinogenic genes, including Six6 and Vsx2. Our results demonstrate that in conjunction with Mitf/Tfec Pax6 acts as an anti-retinogenic factor, whereas in conjunction with retinogenic genes it acts as a pro-retinogenic factor. The results suggest that careful manipulation of the Pax6 regulatory circuit may facilitate the generation of retinal and pigment epithelium cells from embryonic or induced pluripotent stem cells. PMID:22792072

  15. Color me bad: microbial pigments as virulence factors.

    PubMed

    Liu, George Y; Nizet, Victor

    2009-09-01

    A hallmark feature of several pathogenic microbes is the distinctive color of their colonies when propagated in the clinical laboratory. Such pigmentation comes in a variety of hues, and has often proven useful in presumptive clinical diagnosis. Recent advances in microbial pigment biochemistry and the genetic basis of pigment production have sometimes revealed a more sinister aspect to these curious materials that change the color of reflected light by selective light absorbance. In many cases, the microbial pigment contributes to disease pathogenesis by interfering with host immune clearance mechanisms or by exhibiting pro-inflammatory or cytotoxic properties. We review several examples of pigments that promote microbial virulence, including the golden staphyloxanthin of Staphylococcusaureus, the blue-green pyocyanin of Pseudomonas spp., and the dark brown or black melanin pigments of Cryptococcus neoformans and Aspergillus spp. Targeted pigment neutralisation might represent a viable concept to enhance treatment of certain difficult infectious disease conditions. PMID:19726196

  16. Activation of visual pigments by light and heat.

    PubMed

    Luo, Dong-Gen; Yue, Wendy W S; Ala-Laurila, Petri; Yau, King-Wai

    2011-06-10

    Vision begins with photoisomerization of visual pigments. Thermal energy can complement photon energy to drive photoisomerization, but it also triggers spontaneous pigment activation as noise that interferes with light detection. For half a century, the mechanism underlying this dark noise has remained controversial. We report here a quantitative relation between a pigment's photoactivation energy and its peak-absorption wavelength, λ(max). Using this relation and assuming that pigment activations by light and heat go through the same ground-state isomerization energy barrier, we can predict the relative noise of diverse pigments with multi-vibrational-mode thermal statistics. The agreement between predictions and our measurements strongly suggests that pigment noise arises from canonical isomerization. The predicted high noise for pigments with λ(max) in the infrared presumably explains why they apparently do not exist in nature. PMID:21659602

  17. Age-associated glycopeptide pigment in human costal cartilage.

    PubMed Central

    van der Korst, J. K.; Willekens, F. L.; Lansink, A. G.; Henrichs, A. M.

    1977-01-01

    Age-associated pigmentation of human costal cartilage is caused by the accumulation of a brown water-soluble substance which can be only be extracted after proteolytic disruption of the cartilage. After isolation by gel filtration and ion exchange chromatography, the compound was identified as an acid glycopeptide. In contrast to ochronotic pigment and an artificial pigment derived by oxidation of homogentistic acid in alkaline solution, the age-associated cartilage pigment was strongly fluorescent and did not form insoluble complexes with cetylpyridinium chloride. Moreover, age-associated cartilage pigment is alkali resistant, in contrast to the ochronotic pigment. The pigment differs from lipofuscin in being strongly hydrophilic and having no affinity for fat stains. The unidentified chromophore could not be separated from the glycopeptide molecule. PMID:596418

  18. Opsin evolution and expression in Arthropod compound Eyes and Ocelli: Insights from the cricket Gryllus bimaculatus

    PubMed Central

    2012-01-01

    Background Opsins are key proteins in animal photoreception. Together with a light-sensitive group, the chromophore, they form visual pigments which initiate the visual transduction cascade when photoactivated. The spectral absorption properties of visual pigments are mainly determined by their opsins, and thus opsins are crucial for understanding the adaptations of animal eyes. Studies on the phylogeny and expression pattern of opsins have received considerable attention, but our knowledge about insect visual opsins is still limited. Up to now, researchers have focused on holometabolous insects, while general conclusions require sampling from a broader range of taxa. We have therefore investigated visual opsins in the ocelli and compound eyes of the two-spotted cricket Gryllus bimaculatus, a hemimetabolous insect. Results Phylogenetic analyses place all identified cricket sequences within the three main visual opsin clades of insects. We assign three of these opsins to visual pigments found in the compound eyes with peak absorbances in the green (515 nm), blue (445 nm) and UV (332 nm) spectral range. Their expression pattern divides the retina into distinct regions: (1) the polarization-sensitive dorsal rim area with blue- and UV-opsin, (2) a newly-discovered ventral band of ommatidia with blue- and green-opsin and (3) the remainder of the compound eye with UV- and green-opsin. In addition, we provide evidence for two ocellar photopigments with peak absorbances in the green (511 nm) and UV (350 nm) spectral range, and with opsins that differ from those expressed in the compound eyes. Conclusions Our data show that cricket eyes are spectrally more specialized than has previously been assumed, suggesting that similar adaptations in other insect species might have been overlooked. The arrangement of spectral receptor types within some ommatidia of the cricket compound eyes differs from the generally accepted pattern found in holometabolous insect taxa and awaits a

  19. SNP model development for the prediction of eye colour in New Zealand.

    PubMed

    Allwood, Julia S; Harbison, Sallyann

    2013-07-01

    The ability to predict externally visible characteristics (EVCs) from DNA has appeal for use in forensic science, particularly where a forensic database match is not made and an eye witness account is unavailable. This technology has yet to be implemented in casework in New Zealand. The broad cultural diversity and likely population stratification within New Zealand dictates that any EVC predictions made using anonymous DNA must perform accurately in the absence of knowledge of the donor's ancestral background. Here we construct classification tree models with SNPs of known association with eye colour phenotypes in three categories, blue vs. non-blue, brown vs. non-brown and intermediate vs. non-intermediate. A set of nineteen SNPs from ten different known or suspected pigmentation genes were selected from the literature. A training dataset of 101 unrelated individuals from the New Zealand population and representing different ancestral backgrounds were used. We constructed four alternate models capable of predicting eye colour from the DNA genotypes of SNPs located within the HERC2, OCA2, TYR and SLC24A4 genes using probability calculation and classification trees. The final model selected for eye colour prediction exhibited high levels of accuracy for both blue (89%) and brown eye colour (94%). Models were further assessed with a test set of 25 'blind' samples where phenotype was unknown, with blue and brown eye colour predicted correctly where model thresholds were met. Classification trees offer an aesthetically simple and comprehendible model to predict blue and brown eye colour. PMID:23597786

  20. Nature, Source and Function of Pigments in Tardigrades: In Vivo Raman Imaging of Carotenoids in Echiniscus blumi

    PubMed Central

    Bonifacio, Alois; Guidetti, Roberto; Altiero, Tiziana; Sergo, Valter; Rebecchi, Lorena

    2012-01-01

    Tardigrades are microscopic aquatic animals with remarkable abilities to withstand harsh physical conditions such as dehydration or exposure to harmful highly energetic radiation. The mechanisms responsible for such robustness are presently little known, but protection against oxidative stresses is thought to play a role. Despite the fact that many tardigrade species are variously pigmented, scarce information is available about this characteristic. By applying Raman micro-spectroscopy on living specimens, pigments in the tardigrade Echiniscus blumi are identified as carotenoids, and their distribution within the animal body is visualized. The dietary origin of these pigments is demonstrated, as well as their presence in the eggs and in eye-spots of these animals, together with their absence in the outer layer of the animal (i.e., cuticle and epidermis). Using in-vivo semi-quantitative Raman micro-spectroscopy, a decrease in carotenoid content is detected after inducing oxidative stress, demonstrating that this approach can be used for studying the role of carotenoids in oxidative stress-related processes in tardigrades. This approach could be thus used in further investigations to test several hypotheses concerning the function of these carotenoids in tardigrades as photo-protective pigments against ionizing radiations or as antioxidants defending these organisms against the oxidative stress occurring during desiccation processes. PMID:23185564

  1. [Determination of the qualitative and quantitative composition of antocyan pigments as components of dietary supplements and drugs for vision].

    PubMed

    Gottikh, M B; Tashlitskiĭ, V N

    2010-01-01

    Bilberry has been long used in folk medicine and credited for an ability to improve vision, primarily night vision. The major active ingredients of bilberries are antocyans. Experimental and clinical studies confirmed the ability of bilberry antocyans to accelerate the regeneration of the photosensitive pigment rhodopsin, to improve nutrition of the retina, and to restore the tissue mechanisms of its protection. The authors studied the level of bilberry antocyans in 5 samples of dietary supplements and medicines for eyes, which had been bought in Moscow drugstores. The total content of antocyans was determined by pH-differential spectrophotometry. All the test samples were shown to contain antocyan pigments; however, their concentration in different samples varied in a wide range of 0.01 to 4.2%. The maximum content was found in the drug "Focus". The qualitative composition of antocyan pigments was estimated by reverse-phase high performance liquid chromatography. All the test samples other than Vitrum vision forte turned out to contain just bilberry antocyans. The chromatographic profile of a Vitrum vision forte sample was inconsistent with bilberry antocyan pigments and the agent was likely to have another source. PMID:21328891

  2. Cone visual pigments of monotremes: filling the phylogenetic gap.

    PubMed

    Wakefield, Matthew J; Anderson, Mark; Chang, Ellen; Wei, Ke-Jun; Kaul, Rajinder; Graves, Jennifer A Marshall; Grützner, Frank; Deeb, Samir S

    2008-01-01

    We have determined the sequence and genomic organization of the genes encoding the cone visual pigment of the platypus (Ornithorhynchus anatinus) and the echidna (Tachyglossus aculeatus), and inferred their spectral properties and evolutionary pathways. We prepared platypus and echidna retinal RNA and used primers of the middle-wave-sensitive (MWS), long-wave-sensitive (LWS), and short-wave sensitive (SWS1) pigments corresponding to coding sequences that are highly conserved among mammals; to PCR amplify the corresponding pigment sequences. Amplification from the retinal RNA revealed the expression of LWS pigment mRNA that is homologous in sequence and spectral properties to the primate LWS visual pigments. However, we were unable to amplify the mammalian SWS1 pigment from these two species, indicating this gene was lost prior to the echidna-platypus divergence (21 MYA). Subsequently, when the platypus genome sequence became available, we found an LWS pigment gene in a conserved genomic arrangement that resembles the primate pigment, but, surprisingly we found an adjacent (20 kb) SWS2 pigment gene within this conserved genomic arrangement. We obtained the same result after sequencing the echidna genes. The encoded SWS2 pigment is predicted to have a wavelength of maximal absorption of about 440 nm, and is paralogous to SWS pigments typically found in reptiles, birds, and fish but not in mammals. This study suggests the locus control region (LCR) has played an important role in the conservation of photo receptor gene arrays and the control of their spatial and temporal expression in the retina in all mammals. In conclusion, a duplication event of an ancestral cone visual pigment gene, followed by sequence divergence and selection gave rise to the LWS and SWS2 visual pigments. So far, the echidna and platypus are the only mammals that share the gene structure of the LWS-SWS2 pigment gene complex with reptiles, birds and fishes. PMID:18598396

  3. Tubulanus tamias sp. nov. (Nemertea: Palaeonemertea) with Two Different Types of Epidermal Eyes.

    PubMed

    Kajihara, Hiroshi; Kakui, Keiichi; Yamasaki, Hiroshi; Hiruta, Shimpei F

    2015-12-01

    Based on specimens collected subtidally (∼10 m in depth) in Tomioka Bay, Japan, we describe the palaeonemertean Tubulanus tamias sp. nov., which differs from all its congeners in body coloration. In molecular phylogenetic analyses based on partial sequences of the nuclear 18S and 28S rRNA genes and histone H3, as well as the mitochondrial 16S rRNA and cytochrome c oxidase subunit I genes, among selected palaeonemerteans, T. tamias nested with part of the congeners in Tubulanus, while the genus as currently diagnosed appears to be non-monophyletic. Molecular cloning detected polymorphism in 28S rDNA sequences in a single individual of T. tamias, indicating incomplete concerted evolution of multiple copies. Tubulanus tamias is peculiar among tubulanids in having 9-10 pigment-cup eyes in the epidermis on either side of the head anterior to the cerebral sensory organs, and remarkably there are two types of eyes. The anterior 8-9 pairs of eyes, becoming larger from anterior to posterior, are completely embedded in the epidermis and proximally abutting the basement membrane; each pigment cup contains bundle of up to seven, rod-shaped structure that resemble a rhabdomeric photoreceptor cell. In contrast, the posterior-most pair of eyes, larger than most of the anterior ones, have an optical cavity filled with long cilia and opening to the exterior, thus appearing to have ciliary-type photoreceptor cells. The size and arrangement of the eyes indicate that the posterior-most pair of eyes are the remnant of the larval (or juvenile) eyes. PMID:26654043

  4. Navigational mechanisms of migrating monarch butterflies.

    PubMed

    Reppert, Steven M; Gegear, Robert J; Merlin, Christine

    2010-09-01

    Recent studies of the iconic fall migration of monarch butterflies have illuminated the mechanisms behind their southward navigation while using a time-compensated sun compass. Skylight cues, such as the sun itself and polarized light, are processed through both eyes and are probably integrated in the brain's central complex, the presumed site of the sun compass. Time compensation is provided by circadian clocks that have a distinctive molecular mechanism and that reside in the antennae. Monarchs might also use a magnetic compass because they possess two cryptochromes that have the molecular capability for light-dependent magnetoreception. Multiple genomic approaches are now being used with the aim of identifying navigation genes. Monarch butterflies are thus emerging as an excellent model organism in which to study the molecular and neural basis of long-distance migration. PMID:20627420

  5. Radon depth migration

    SciTech Connect

    Hildebrand, S.T. ); Carroll, R.J. )

    1993-02-01

    A depth migration method is presented that used Radon-transformed common-source seismograms as input. It is shown that the Radon depth migration method can be extended to spatially varying velocity depth models by using asymptotic ray theory (ART) to construct wavefield continuation operators. These operators downward continue an incident receiver-array plane wave and an assumed point-source wavefield into the subsurface. The migration velocity model is constrain to have longer characteristic wavelengths than the dominant source wavelength such that the ART approximations for the continuation operators are valid. This method is used successfully to migrate two synthetic data examples: (1) a point diffractor, and (2) a dipping layer and syncline interface model. It is shown that the Radon migration method has a computational advantage over the standard Kirchhoff migration method in that fewer rays are computed in a main memory implementation.

  6. Bleached pigment activates transduction in salamander cones

    PubMed Central

    1995-01-01

    We have used suction electrode recording together with rapid steps into 0.5 mM IBMX solution to investigate changes in guanylyl cyclase velocity produced by pigment bleaching in isolated cones of the salamander Ambystoma tigrinum. Both backgrounds and bleaches accelerate the time course of current increase during steps into IBMX. We interpret this as evidence that the velocity of the guanylyl cyclase is increased in background light or after bleaching. Our results indicate that cyclase velocity increases nearly linearly with increasing percent pigment bleached but nonlinearly (and may saturate) with increasing back-ground intensity. In cones (as previously demonstrated for rods), light-activated pigment and bleached pigment appear to have somewhat different effects on the transduction cascade. The effect of bleaching on cyclase rate is maintained for at least 15-20 min after the light is removed, much longer than is required after a bleach for circulating current and sensitivity to stabilize in an isolated cone. The effect on the cyclase rate can be completely reversed by treatment with liposomes containing 11-cis retinal. The effects of bleaching can also be partially reversed by beta-ionone, an analogue of the chromophore 11- cis-retinal which does not form a covalent attachment to opsin. Perfusion of a bleached cone with beta-ionone produces a rapid increase in circulating current and sensitivity, which rapidly reverses when the beta-ionone is removed. Perfusion with beta-ionone also causes a partial reversal of the bleach-induced acceleration of cyclase velocity. We conclude that bleaching produces an "equivalent background" excitation of the transduction cascade in cones, perhaps by a mechanism similar to that in rods. PMID:8786347

  7. Practice and Educational Gaps in Abnormal Pigmentation.

    PubMed

    Mohammad, Tasneem F; Hamzavi, Iltefat H

    2016-07-01

    Dyschromia refers to abnormal pigmentation and is one of the most common diagnoses in dermatology. However, there are many educational and practice gaps in this area, specifically in melasma, postinflammatory hyperpigmentation, and vitiligo. This article aims to review the gold standard of care for these conditions as well as highlight common educational and practice gaps in these areas. Finally, possible solutions to these gaps are addressed. PMID:27363886

  8. Diet-induced pigmented purpuric dermatosis.

    PubMed

    Weiß, Katharina T; Karrer, Sigrid; Landthaler, Michael; Babilas, Philipp; Schreml, Stephan

    2014-08-01

    Pigmented purpuric dermatoses (PPD) are chronic and relapsing disorders characterised by a localised or generalised purpuric rash. Even though the clinical presentation of PPD subtypes varies, they have a similar histopathology. The aetiology is largely unknown, but trigger factors, such as drugs, infections and systemic illnesses have been described. To our knowledge, this is the only case showing widespread PPD lesions not only induced but also rapidly provoked by dietary factors, namely Coca Cola and apple-cherry fruit spritzer. PMID:23574037

  9. Skin pigmentation, biogeographical ancestry and admixture mapping.

    PubMed

    Shriver, Mark D; Parra, Esteban J; Dios, Sonia; Bonilla, Carolina; Norton, Heather; Jovel, Celina; Pfaff, Carrie; Jones, Cecily; Massac, Aisha; Cameron, Neil; Baron, Archie; Jackson, Tabitha; Argyropoulos, George; Jin, Li; Hoggart, Clive J; McKeigue, Paul M; Kittles, Rick A

    2003-04-01

    Ancestry informative markers (AIMs) are genetic loci showing alleles with large frequency differences between populations. AIMs can be used to estimate biogeographical ancestry at the level of the population, subgroup (e.g. cases and controls) and individual. Ancestry estimates at both the subgroup and individual level can be directly instructive regarding the genetics of the phenotypes that differ qualitatively or in frequency between populations. These estimates can provide a compelling foundation for the use of admixture mapping (AM) methods to identify the genes underlying these traits. We present details of a panel of 34 AIMs and demonstrate how such studies can proceed, by using skin pigmentation as a model phenotype. We have genotyped these markers in two population samples with primarily African ancestry, viz. African Americans from Washington D.C. and an African Caribbean sample from Britain, and in a sample of European Americans from Pennsylvania. In the two African population samples, we observed significant correlations between estimates of individual ancestry and skin pigmentation as measured by reflectometry (R(2)=0.21, P<0.0001 for the African-American sample and R(2)=0.16, P<0.0001 for the British African-Caribbean sample). These correlations confirm the validity of the ancestry estimates and also indicate the high level of population structure related to admixture, a level that characterizes these populations and that is detectable by using other tests to identify genetic structure. We have also applied two methods of admixture mapping to test for the effects of three candidate genes (TYR, OCA2, MC1R) on pigmentation. We show that TYR and OCA2 have measurable effects on skin pigmentation differences between the west African and west European parental populations. This work indicates that it is possible to estimate the individual ancestry of a person based on DNA analysis with a reasonable number of well-defined genetic markers. The implications and

  10. Pigmented median raphe cyst of the penis with consideration of the possible mechanism of melanocytic colonization: A case report

    PubMed Central

    ISHIDA, MITSUAKI; IWAI, MUNEO; YOSHIDA, KEIKO; KAGOTANI, AKIKO; OKABE, HIDETOSHI

    2014-01-01

    Median raphe cyst is a rare lesion located on the median raphe. The cyst wall is lined by cuboidal to columnar cells, transitional (urothelial) cells, stratified squamous cells or a mixture of these. The normal urethral mucosa and the median raphe cyst usually lack melanocytes and/or melanin pigment. However, albeit extremely rare, the presence of melanin pigment and/or melanocytes in median raphe cyst, namely pigmented median raphe cyst, has been previously reported. The current case report presents the sixth case of pigmented median raphe cyst and discusses the possible mechanism of melanocytic colonization in this tumor. A 48-year-old male presented with a nodule on the ventral surface of the penis. Histopathological study revealed that the cyst wall was covered by uniform bland cuboidal to urothelial cells. The peculiar observation was the presence of dendritic melanocytes among the epithelial cells. Therefore, a diagnosis of pigmented median raphe cyst was determined. Immunohistochemically, stem cell factor and endothelin-1 were not expressed in the epithelial cells of the cyst wall. It is well-known that melanocytes are rarely found in various non-melanocytic tumors, a phenomenon termed ‘colonization’. The mechanism by which melanocytes appear in median raphe cyst remains unclear. The present report is the first to demonstrate that melanocytic proliferation and differentiation factors, such as stem cell factor and endothelin-1, are not involved in the pigmentation of median raphe cyst. In addition, aberrant melanocytic migration may contribute to the development of this type of lesion. PMID:24396444

  11. Optical tomography of pigmented human skin biopsies

    NASA Astrophysics Data System (ADS)

    Riemann, Iris; Fischer, Peter; Kaatz, Martin; Fischer, Tobias W.; Elsner, Peter; Dimitrov, Enrico; Reif, Annette; Konig, Karsten

    2004-07-01

    The novel femtosecond NIR (near infrared) laser based high resolution imaging system DermaInspect was used for non-invasive diagnostics of pigmented skin. The system provides fluorescence and SHG images of high spatial submicron resolution (3D) and 250 ps temporal resolution (4D) based on time resolved single photon counting (TCSPC). Pigmented tissue biopsies from patients with nevi and melanoma have been investigated using the tunable 80 MHz femtosecond laser MaiTai with laser wavelengths in the range of 750 - 850 nm. The autofluorescence patterns of different intratissue cell types and structures were determined. The non-linear induced autofluorescence originates from naturally endogenous fluorophores and protein structures like NAD(P)H, flavins, elastin, collagen, phorphyrins and melanin. In addition to autofluorescence, SHG (second harmonic generation) was used to detect dermal collagen structures. Interestingly, pigmented cells showed intense luminescence signals. Further characterization of tissue components was performed via 4D measurements of the fluorescence lifetime (x, y, z, τ). The novel multiphoton technique offers the possibility of a painless high resolution non invasive diagnostic method (optical biopsy), in particular for the early detection of skin cancer.

  12. Blackberry pigment (whitlockite) gallstones in uremic patient.

    PubMed

    Cariati, Andrea

    2013-04-01

    Black pigment gallstones represent nearly the 15% of all gallstones and are usually related with the typical "hyperbilirubinbilia" factors as hemolysis, ineffective erythropoiesis, pathologic enterohepatic cycling of unconjugated bilirubin, cirrhosis and with gallbladder mucosa (parietal) factors as adenomyomatosis. During a prospective study on 179 patients who underwent cholecystectomy for gallstone disease a 69-year-old female with predialysis chronic kidney disease was operated for symptomatic gallstone. The removed gallstones were black pigment gallstones, with an irregular (as small blackberry) surface. Analysis of the stones revealed a great amount of whitlockite (Ca Mg)3 (PO4)2. Recent studies on chronic renal failure patients found that chronic uremia is associated with an increased risk of gallstones formation (22%) as it seems in women affected by primary hyperparathyroidism (30%). The presence of calcium phosphate gallstones in these patients have been never described. In conclusion, further studies could be necessary to establish the role of chronic renal failure and of primary and secondary hyperparathyroidism in gallstones formation and, in particular, if dialysis and predialysis patients have an higher risk to develop cholesterol and black pigment gallstones in particular of the "blackberry" (whitlockite) subtype. PMID:22959097

  13. The photochromic effect of bismuth vanadate pigments. Part I: Synthesis, characterization and lightfastness of pigment coatings

    NASA Astrophysics Data System (ADS)

    Tücks, A.; Beck, H. P.

    2005-04-01

    We report on investigations of the photochromic effect of BiVO 4 pigments. Emphasis is placed on an approach widely used in industrial color testing. By means of colorimetry Δ E ab*-values, which measure the perceived color difference, can be calculated from reflectance spectra of non-illuminated and illuminated pigment coatings. Pigments were prepared by either wet-chemical precipitation or solid-state reactions. Depending on the choice of starting compounds, lightfastness was found to vary significantly. Small amounts of impurity phases do not seem to affect photochromism. In contrast, impurities like Fe and Pb cause intense photochromism. The role of Fe is suggested by trace analyses, which (in case of pigments synthesized by precipitation reactions) reveal a correlation between concentration and Δ E ab*. Indications are found that other effects like pigment-lacquer interactions might also be of importance. Difference reflectance spectra turn out to vary in shape depending on the type and concentration of impurities or dopants. For BiVO 4 at least three different mechanisms of photochromism can be assumed.

  14. The photochromic effect of bismuth vanadate pigments. Part I: Synthesis, characterization and lightfastness of pigment coatings

    SciTech Connect

    Tuecks, A.; Beck, H.P. . E-mail: hp.beck@mx.uni-saarland.de

    2005-04-15

    We report on investigations of the photochromic effect of BiVO{sub 4} pigments. Emphasis is placed on an approach widely used in industrial color testing. By means of colorimetry {delta}E{sub ab}*-values, which measure the perceived color difference, can be calculated from reflectance spectra of non-illuminated and illuminated pigment coatings. Pigments were prepared by either wet-chemical precipitation or solid-state reactions. Depending on the choice of starting compounds, lightfastness was found to vary significantly. Small amounts of impurity phases do not seem to affect photochromism. In contrast, impurities like Fe and Pb cause intense photochromism. The role of Fe is suggested by trace analyses, which (in case of pigments synthesized by precipitation reactions) reveal a correlation between concentration and {delta}E{sub ab}*. Indications are found that other effects like pigment-lacquer interactions might also be of importance. Difference reflectance spectra turn out to vary in shape depending on the type and concentration of impurities or dopants. For BiVO{sub 4} at least three different mechanisms of photochromism can be assumed.

  15. Aquaporins and cell migration.

    PubMed

    Papadopoulos, M C; Saadoun, S; Verkman, A S

    2008-07-01

    Aquaporin (AQP) water channels are expressed primarily in cell plasma membranes. In this paper, we review recent evidence that AQPs facilitate cell migration. AQP-dependent cell migration has been found in a variety of cell types in vitro and in mice in vivo. AQP1 deletion reduces endothelial cell migration, limiting tumor angiogenesis and growth. AQP4 deletion slows the migration of reactive astrocytes, impairing glial scarring after brain stab injury. AQP1-expressing tumor cells have enhanced metastatic potential and local infiltration. Impaired cell migration has also been seen in AQP1-deficient proximal tubule epithelial cells, and AQP3-deficient corneal epithelial cells, enterocytes, and skin keratinocytes. The mechanisms by which AQPs enhance cell migration are under investigation. We propose that, as a consequence of actin polymerization/depolymerization and transmembrane ionic fluxes, the cytoplasm adjacent to the leading edge of migrating cells undergoes rapid changes in osmolality. AQPs could thus facilitate osmotic water flow across the plasma membrane in cell protrusions that form during migration. AQP-dependent cell migration has potentially broad implications in angiogenesis, tumor metastasis, wound healing, glial scarring, and other events requiring rapid, directed cell movement. AQP inhibitors may thus have therapeutic potential in modulating these events, such as slowing tumor growth and spread, and reducing glial scarring after injury to allow neuronal regeneration. PMID:17968585

  16. How to administer eye drops and eye ointment.

    PubMed

    Shaw, Mary

    2016-05-25

    Rationale and key points Eye drops and eye ointment are the mainstay of treatment of ocular conditions. Failure to prioritise administration of these medicines can prolong the condition and may present a risk to the patient's vision. ▶ Eye drops and eye ointments are used to treat acute and chronic conditions of the eye and surrounding structures. Eye drops must be instilled before applying eye ointment, since the ointment will affect the absorption of the eye drop. ▶ Nurses require knowledge of the technique, side effects and potential interactions associated with systemically or topically applied medicines to the eye to ensure patient safety and optimum outcomes. Reflective activity Clinical skills articles can help update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of: 1. How this article will change your practice. 2. How you intend to develop your knowledge and skills regarding treatment of ocular conditions. Subscribers can update their reflective accounts at rcni.com/portfolio. PMID:27224628

  17. Opsins in onychophora (velvet worms) suggest a single origin and subsequent diversification of visual pigments in arthropods.

    PubMed

    Hering, Lars; Henze, Miriam J; Kohler, Martin; Kelber, Almut; Bleidorn, Christoph; Leschke, Maren; Nickel, Birgit; Meyer, Matthias; Kircher, Martin; Sunnucks, Paul; Mayer, Georg

    2012-11-01

    Multiple visual pigments, prerequisites for color vision, are found in arthropods, but the evolutionary origin of their diversity remains obscure. In this study, we explore the opsin genes in five distantly related species of Onychophora, using deep transcriptome sequencing and screening approaches. Surprisingly, our data reveal the presence of only one opsin gene (onychopsin) in each onychophoran species, and our behavioral experiments indicate a maximum sensitivity of onychopsin to blue-green light. In our phylogenetic analyses, the onychopsins represent the sister group to the monophyletic clade of visual r-opsins of arthropods. These results concur with phylogenomic support for the sister-group status of the Onychophora and Arthropoda and provide evidence for monochromatic vision in velvet worms and in the last common ancestor of Onychophora and Arthropoda. We conclude that the diversification of visual pigments and color vision evolved in arthropods, along with the evolution of compound eyes-one of the most sophisticated visual systems known. PMID:22683812

  18. Contribution of a visual pigment absorption spectrum to a visual function: depth perception in a jumping spider

    PubMed Central

    Nagata, Takashi; Arikawa, Kentaro; Terakita, Akihisa

    2013-01-01

    Absorption spectra of visual pigments are adaptively tuned to optimize informational capacity in most visual systems. Our recent investigation of the eyes of the jumping spider reveals an apparent exception: the absorption characteristics of a visual pigment cause defocusing of the image, reducing visual acuity generally in a part of the retina. However, the amount of defocus can theoretically provide a quantitative indication of the distance of an object. Therefore, we proposed a novel mechanism for depth perception in jumping spiders based on image defocus. Behavioral experiments revealed that the depth perception of the spider depended on the wavelength of the ambient light, which affects the amount of defocus because of chromatic aberration of the lens. This wavelength effect on depth perception was in close agreement with theoretical predictions based on our hypothesis. These data strongly support the hypothesis that the depth perception mechanism of jumping spiders is based on image defocus.

  19. [Eye and the environment].

    PubMed

    Voide, Nathalie; Kaeser, Pierre-François; Behar-Cohen, Francine

    2015-12-16

    The eyes are exposed to multiple environmental factors, which affect visual development, comfort, and visual health. While overexposure to sunlight can cause ocular surface and retinal pathologies, insufficient exposure to daylight could significantly contribute to myopia progression. New artificial lights, namely LED, have a higher risk of retinal phototoxicity, and could alter ocular circadian rhythm. The significant increase of prevalence of ocular allergies could be caused by the proliferation of environmental polluting substances, like tobacco smoke, fuel combustion by-products, or phtalates, which are found in many types of plastics. Finally, some dietary supplements could play a protective role in certain types of ocular pathologies, namely retinal pathologies. PMID:26852551

  20. Lens of Eye Dosimetry

    SciTech Connect

    Mallett, Michael Wesley

    2015-03-23

    An analysis of LANL occupational dose measurements was made with respect to lens of eye dose (LOE), in particular, for plutonium workers. Table 1 shows the reported LOE as a ratio of the “deep” (photon only) and “deep+neutron” dose for routine monitored workers at LANL for the past ten years. The data compares the mean and range of these values for plutonium workers* and non-routine plutonium workers. All doses were reported based on measurements with the LANL Model 8823 TLD.