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Sample records for age pigment lipofuscin

  1. 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.

  2. Potential role of retinal pigment epithelial lipofuscin accumulation in age-related macular degeneration.

    PubMed

    Katz, Martin L

    2002-01-01

    Age-related macular degeneration (AMD) is a leading cause of severe visual impairment in developed countries. The vision loss associated with AMD is the result of degenerative changes in the central region of the retina called the macula. Maintenance of normal structure and function of the macular retina, and of the remainder of the retina as well, is critically dependent on the supporting role of the adjacent retinal pigment epithelium (RPE). Impairment of normal RPE functions is known to result in retinal degeneration and loss of visual function. Thus, it has been hypothesized that the retinal degeneration that characterizes AMD is secondary to age-related deterioration in RPE support functions. Like many other postmitotic cell types, the RPE accumulates autofluorescent lysosomal storage bodies (lipofuscin) during senescence. In human eyes, lipofuscin comes to occupy a substantial fraction of the RPE cytoplasmic volume in the elderly. Does this lipofuscin accumulation contribute to the development of AMD? This question is a specific case of the broader question of whether lipofuscin accumulation in general is detrimental to cells. Unfortunately, definitive data do not exist to allow these questions to be answered. Although a correlation between RPE lipofuscin content and AMD has been reported, a cause-and-effect relationship between RPE lipofuscin accumulation and the development of this disease has not been established. It has been reported that a mutation in a gene encoding a photoreceptor-specific protein results in massive RPE lipofuscin accumulation and early-onset macular degeneration. However, again the accelerated RPE lipofuscin accumulation has not been shown to be the cause of the accompanying macular degeneration. The lack of a definitive link between RPE lipofuscin accumulation and AMD illustrates one of the biggest challenges remaining in lipofuscin research-determining whether lipofuscin accumulation per se has an impact on cell function.

  3. 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

  4. Dynamic Scaling of Lipofuscin Deposition in Aging Cells

    NASA Astrophysics Data System (ADS)

    Family, Fereydoon; Mazzitello, K. I.; Arizmendi, C. M.; Grossniklaus, H. E.

    2011-07-01

    Lipofuscin is a membrane-bound cellular waste that can be neither degraded nor ejected from the cell but can only be diluted through cell division and subsequent growth. The fate of postmitotic (non-dividing) cells such as neurons, cardiac myocytes, skeletal muscle fibers, and retinal pigment epithelial cells (RPE) is to accumulate lipofuscin, which as an "aging pigment" has been considered a reliable biomarker for the age of cells. Environmental stress can accelerate the accumulation of lipofuscin. For example, accumulation in brain cells appears to be an important issue connected with heavy consumption of alcohol. Lipofuscin is made of free-radical-damaged protein and fat, whose abnormal accumulation is related to a range of disorders including Type IV mucolipidosis (ML4), Amyotrophic Lateral Sclerosis (ALS), Alzheimer's disease, Parkinson disease, and age-related macular degeneration (AMD) which is the leading cause of blindness beyond the age of 50 years. The study of lipofuscin formation and growth is important, because of their association with cellular aging. We introduce a model of non-equilibrium cluster growth and aggregation that we have developed for studying the formation and growth of lipofuscin. As an example of lipofuscin deposit in a given kind of postmitotic cell, we study the kinetics of lipofuscin growth in a RPE cell. Our results agree with a linear growth of the number of lipofuscin granules with age. We apply the dynamic scaling approach to our model and find excellent data collapse for the cluster size distribution. An unusual feature of our model is that while small particles are removed from the cell the larger ones become fixed and grow by aggregation.

  5. Lipofuscin Granules in the Epileptic Human Temporal Neocortex with Age.

    PubMed

    Merlo, Suélen; Nakayama, Ana Beatriz S; Brusco, Janaina; Rossi, Marcos A; Carlotti, Carlos G; Moreira, Jorge E

    2015-01-01

    Lipofuscin granules (LGs), the "age pigments", are autofluorescent cell products from lysosomes that diverge in number and size among brain regions. Human temporal cortex from 20- to 55-year-old epileptic subjects were studied with the fat soluble dye Sudan Black, under confocal and electron microscopy. Ultrastructural analysis showed that with age LGs increase in area, but not in number. Proportionally to the LGs area, the electron lucid portion increases and the electron dense reduces over time. The robust increase in lipid components is possibly due to modifications in the neuronal metabolism with age in physiological and pathological conditions.

  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. Physics of Lipofuscin Formation and Growth in Age Related Macular Degeneration

    NASA Astrophysics Data System (ADS)

    Family, Fereydoon; Mazzitello, K. I.; Arizmendi, C. M.; Grossniklaus, Hans E.

    2010-02-01

    Age-related macular degeneration (AMD) is the leading cause of blindness beyond the age of 50 years. The most common pathogenic mechanism that leads to AMD is choroidal neovascularization (CNV). CNV is produced by accumulation of residual material caused by aging of retinal pigment epithelium cells (RPE). With time, incompletely degraded membrane material builds up in the RPE in the form of lipofuscin. Lipofuscin is made of free-radical-damaged protein and fat, which forms not only in AMD, but also Alzheimer disease, and Parkinson disease. 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 to the number of lipofuscin granules in eyes with early age-related degeneration. )

  8. Similar molecules spatially correlate with lipofuscin and N-retinylidene-N-retinylethanolamine in the mouse but not in the human retinal pigment epithelium

    PubMed Central

    Ablonczy, Zsolt; Higbee, Daniel; Grey, Angus C.; Koutalos, Yiannis; Schey, Kevin L.; Crouch, Rosalie K.

    2013-01-01

    The accumulation of lipofuscin in the retinal pigment epithelium (RPE) has been implicated in the development of age-related macular degeneration (AMD) in humans. The exact composition of lipofuscin is not known but its best characterized component is N-retinylidene-N-retinylethanolamine (A2E), a byproduct of the retinoid visual cycle. Utilizing our recently developed matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS)-based technique to determine the spatial distribution of A2E, this study compares the relationships of lipofuscin fluorescence and A2E in the murine and human RPE on representative normal tissue. To identify molecules with similar spatial patterns, the images of A2E and lipofuscin were correlated with all the individual images in the MALDI-IMS dataset. In the murine RPE, there was a remarkable correlation between A2E and lipofuscin. In the human RPE, however, minimal correlation was detected. These results were reflected in the marked distinctions between the molecules that spatially correlated with the images of lipofuscin and A2E in the human RPE. While the distribution of murine lipofuscin showed highest similarities with some of the known A2E-adducts, the composition of human lipofuscin was significantly different. These results indicate that A2E metabolism may be altered in the human compared to the murine RPE. PMID:23969078

  9. Beta cyclodextrins bind, stabilize, and remove lipofuscin bisretinoids from retinal pigment epithelium

    PubMed Central

    Nociari, Marcelo M.; Lehmann, Guillermo L.; Perez Bay, Andres E.; Radu, Roxana A.; Jiang, Zhichun; Goicochea, Shelby; Schreiner, Ryan; Warren, J. David; Shan, Jufang; Adam de Beaumais, Ségolène; Ménand, Mickaël; Sollogoub, Matthieu; Maxfield, Frederick R.; Rodriguez-Boulan, Enrique

    2014-01-01

    Accumulation of lipofuscin bisretinoids (LBs) in the retinal pigment epithelium (RPE) is the alleged cause of retinal degeneration in genetic blinding diseases (e.g., Stargardt) and a possible etiological agent for age-related macular degeneration. Currently, there are no approved treatments for these diseases; hence, agents that efficiently remove LBs from RPE would be valuable therapeutic candidates. Here, we show that beta cyclodextrins (β-CDs) bind LBs and protect them against oxidation. Computer modeling and biochemical data are consistent with the encapsulation of the retinoid arms of LBs within the hydrophobic cavity of β-CD. Importantly, β-CD treatment reduced by 73% and 48% the LB content of RPE cell cultures and of eyecups obtained from Abca4-Rdh8 double knock-out (DKO) mice, respectively. Furthermore, intravitreal administration of β-CDs reduced significantly the content of bisretinoids in the RPE of DKO animals. Thus, our results demonstrate the effectiveness of β-CDs to complex and remove LB deposits from RPE cells and provide crucial data to develop novel prophylactic approaches for retinal disorders elicited by LBs. PMID:24706818

  10. Beta cyclodextrins bind, stabilize, and remove lipofuscin bisretinoids from retinal pigment epithelium.

    PubMed

    Nociari, Marcelo M; Lehmann, Guillermo L; Perez Bay, Andres E; Radu, Roxana A; Jiang, Zhichun; Goicochea, Shelby; Schreiner, Ryan; Warren, J David; Shan, Jufang; Adam de Beaumais, Ségolène; Ménand, Mickaël; Sollogoub, Matthieu; Maxfield, Frederick R; Rodriguez-Boulan, Enrique

    2014-04-08

    Accumulation of lipofuscin bisretinoids (LBs) in the retinal pigment epithelium (RPE) is the alleged cause of retinal degeneration in genetic blinding diseases (e.g., Stargardt) and a possible etiological agent for age-related macular degeneration. Currently, there are no approved treatments for these diseases; hence, agents that efficiently remove LBs from RPE would be valuable therapeutic candidates. Here, we show that beta cyclodextrins (β-CDs) bind LBs and protect them against oxidation. Computer modeling and biochemical data are consistent with the encapsulation of the retinoid arms of LBs within the hydrophobic cavity of β-CD. Importantly, β-CD treatment reduced by 73% and 48% the LB content of RPE cell cultures and of eyecups obtained from Abca4-Rdh8 double knock-out (DKO) mice, respectively. Furthermore, intravitreal administration of β-CDs reduced significantly the content of bisretinoids in the RPE of DKO animals. Thus, our results demonstrate the effectiveness of β-CDs to complex and remove LB deposits from RPE cells and provide crucial data to develop novel prophylactic approaches for retinal disorders elicited by LBs.

  11. Human and rat brain lipofuscin proteome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The accumulation of an autofluorescent pigment called lipofuscin in neurons is an invariable hallmark of brain aging. So far, this material has been considered to be waste material without particular relevance for cellular pathology. However, two lines of evidence argue that lipofuscin may have yet ...

  12. Inhibition or Stimulation of Autophagy Affects Early Formation of Lipofuscin-Like Autofluorescence in the Retinal Pigment Epithelium Cell.

    PubMed

    Lei, Lei; Tzekov, Radouil; Li, Huapeng; McDowell, J Hugh; Gao, Guangping; Smith, W Clay; Tang, Shibo; Kaushal, Shalesh

    2017-03-29

    The accumulation of lipofuscin in the retinal pigment epithelium (RPE) is dependent on the effectiveness of photoreceptor outer segment material degradation. This study explored the role of autophagy in the fate of RPE lipofuscin degradation. After seven days of feeding with either native or modified rod outer segments, ARPE-19 cells were treated with enhancers or inhibitors of autophagy and the autofluorescence was detected by fluorescence-activated cell sorting. Supplementation with different types of rod outer segments increased lipofuscin-like autofluorescence (LLAF) after the inhibition of autophagy, while the induction of autophagy (e.g., application of rapamycin) decreased LLAF. The effects of autophagy induction were further confirmed by Western blotting, which showed the conversion of LC3-I to LC3-II, and by immunofluorescence microscopy, which detected the lysosomal activity of the autophagy inducers. We also monitored LLAF after the application of several autophagy inhibitors by RNA-interference and confocal microscopy. The results showed that, in general, the inhibition of the autophagy-related proteins resulted in an increase in LLAF when cells were fed with rod outer segments, which further confirms the effect of autophagy in the fate of RPE lipofuscin degradation. These results emphasize the complex role of autophagy in modulating RPE autofluorescence and confirm the possibility of the pharmacological clearance of RPE lipofuscin by small molecules.

  13. Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2E

    PubMed Central

    Saadat, Khandakar A.S.M.; Murakami, Yusuke; Tan, Xue; Nomura, Yoko; Yasukawa, Tsutomu; Okada, Eiichi; Ikeda, Yasuhiro; Yanagi, Yasuo

    2014-01-01

    In this study, we show augmented autophagy in the retinal pigment epithelial cell line ARPE-19 when cultured in the presence of the lipofuscin pigment A2E. A2E alone does not induce RPE cell death, but cell death was induced in the presence of A2E with the autophagy inhibitor 3-methyladenine (3MA), with a concomitant increase in the generation of mitochondrial reactive oxygen species. On the other hand, the ATP production capacity of mitochondria was decreased in the presence of A2E, and pharmacological inhibition of autophagy had no additional effects. The altered mRNA expression level of mitochondrial function markers was confirmed by real-time polymerase chain reaction, which showed that the antioxidant enzymes SOD1 and SOD2 were not reduced in the presence of A2E alone, but significantly suppressed with the addition of 3MA. Furthermore, transmission electron micrography revealed autophagic vacuole formation in the presence of A2E, and inhibition of autophagy resulted in the accumulation of abnormal mitochondria with loss of cristae. Spheroid culture of human RPE cells demonstrated debris accumulation in the presence of A2E, and this accumulation was accelerated in the presence of 3MA. These results indicate that autophagy in RPE cells is a vital cytoprotective process that prevents the accumulation of damaged cellular molecules. PMID:25473597

  14. Lack of Correlation Between the Spatial Distribution of A2E and Lipofuscin Fluorescence in the Human Retinal Pigment Epithelium

    PubMed Central

    Ablonczy, Zsolt; Higbee, Daniel; Anderson, David M.; Dahrouj, Mohammad; Grey, Angus C.; Gutierrez, Danielle; Koutalos, Yiannis; Schey, Kevin L.; Hanneken, Anne; Crouch, Rosalie K.

    2013-01-01

    Purpose. The accumulation of lipofuscin in the RPE is a hallmark of aging in the eye. The best characterized component of lipofuscin is A2E, a bis-retinoid byproduct of the normal retinoid visual cycle, which exhibits a broad spectrum of cytotoxic effects in vitro. The purpose of our study was to correlate the distribution of lipofuscin and A2E across the human RPE. Methods. Lipofuscin fluorescence was imaged in flat-mounted RPE from human donors of various ages. The spatial distributions of A2E and its oxides were determined using matrix-assisted laser desorption-ionization imaging mass spectrometry (MALDI-IMS) on flat-mounted RPE tissue sections and retinal cross-sections. Results. Our data support the clinical observations of strong RPE fluorescence, increasing with age, in the central area of the RPE. However, there was no correlation between the distribution of A2E and lipofuscin, as the levels of A2E were highest in the far periphery and decreased toward the central region. High-resolution MALDI-IMS of retinal cross-sections confirmed the A2E localization data obtained in RPE flat-mounts. Singly- and doubly-oxidized A2E had distributions similar to A2E, but represented <10% of the A2E levels. Conclusions. This report to our knowledge is the first description of the spatial distribution of A2E in the human RPE by imaging mass spectrometry. These data demonstrate that the accumulation of A2E is not responsible for the increase in lipofuscin fluorescence observed in the central RPE with aging. PMID:23847313

  15. The age related markers lipofuscin and apoptosis show different genetic architecture by QTL mapping in short-lived Nothobranchius fish

    PubMed Central

    Ng'oma, Enoch; Reichwald, Kathrin; Dorn, Alexander; Wittig, Michael; Balschun, Tobias; Franke, Andre; Platzer, Matthias; Cellerino, Allesandro

    2014-01-01

    Annual fish of the genus Nothobranchius show large variations in lifespan and expression of age-related phenotypes between closely related populations. We studied N. kadleci and its sister species N. furzeri GRZ strain, and found that N.kadleci is longer-lived than the N. furzeri. Lipofuscin and apoptosis measured in the liver increased with age in N. kadleci with different profiles: lipofuscin increased linearly, while apoptosis declined in the oldest animals. More lipofuscin (P < 0.001) and apoptosis (P < 0.001) was observed in N. furzeri than in N. kadleci at 16w age. Lipofuscin and apoptotic cells were then quantified in hybrids from the mating of N. furzeri to N. kadleci. F1 individuals showed heterosis for lipofuscin but additive effects for apoptosis. These two age-related phenotypes were not correlated in F2 hybrids. Quantitative trait loci analysis of 287 F2 fish using 237 markers identified two QTL accounting for 10% of lipofuscin variance (P < 0.001) with overdominance effect. Apoptotic cells revealed three significant- and two suggestive QTL explaining 19% of variance (P < 0.001), showing additive and dominance effects, and two interacting loci. Our results show that lipofuscin and apoptosis are markers of different age-dependent biological processes controlled by different genetic mechanisms. PMID:25093339

  16. Evaluation of lipofuscin-like pigments as an index of lead-induced oxidative damage in the brain.

    PubMed

    Patková, Jana; Vojtíšek, Max; Tůma, Jan; Vožeh, František; Knotková, Jana; Santorová, Pavlína; Wilhelm, Jiří

    2012-01-01

    This study was carried out to investigate the role of lead in the development of oxidative stress in the brain. We examined the rate of lipid peroxidation and we determined lipid fluorescence products (lipofuscin-like pigments - LFP) as a marker of lipid peroxidation after short in vitro incubation of rat brain homogenates with lead acetate (10(-2), 10(-4), 10(-6) M lead acetate, 2 h). Simultaneously we examined by the same method in vivo indices of oxidative stress in brains of mice exposed for 12 weeks to 0.2% lead acetate in drinking water. The results show that the concentration of LFP in rat brain homogenates increased significantly after 2 h incubation with 10(-2) M lead acetate as compared to controls (P<0.0001). This effect was not observed in lower doses of lead acetate (10(-4) and 10(-6) M). After the long-term exposure of mice to 0.2% lead acetate, pronounced accumulation of lead and significantly increased concentration of LFP (P<0.004) in the brains of exposed animals as compared to controls were observed. The evidence for the formation of specific fluorophores originating from oxidative damage was shown also in qualitative changes in 3D spectral arrays and synchronous spectra. The presented results proved the influence of lead on the activation of radical reactions in the brain after short in vitro exposure of rat brain as well as within long-term in vivo exposure in mice using lipofuscin-like pigments as an indicator of oxidative stress.

  17. Lipofuscin-like pigment in gonads of Sea Urchin Strongylocentrotus intermedius as a potential biomarker of marine pollution: a field study.

    PubMed

    Vaschenko, Marina A; Zhadan, Peter M; Aminin, Dmitry L; Almyashova, Tatyana N

    2012-05-01

    Accumulation of lipofuscin-like pigments (LLPs) has been shown to be an appropriate index of both age and stress in some aquatic invertebrates. In the present study, LLP was quantified by measuring its autofluorescence intensity (ex 450 nm/em 512 nm) in nutritive phagocytes (NPs) of sea urchins Strongylocentrotus intermedius inhabiting polluted and relatively clean areas of Japan Sea. To avoid variations in LLP content related to sea urchin reproductive condition, only developing gonads with acini occupied mostly by NPs were used for LLP quantification as well as semiquantitative histopathological analysis. LLP concentrations ranged from 0.0 to 4.57 ± 0.53% area fraction in female gonads and from 0.0 to 4.61 ± 0.35% in male gonads. The presence of specimens with extremely high LLP concentrations (>1.5%) in all examined samples, including specimens from the reference station, as well as the absence of strong correlations between LLP concentrations and several parameters related to pollution (heavy-metal concentrations in sea urchin gonads and concentrations of heavy metals, DDT, hexachlorocyclohexane, and total petroleum hydrocarbons in sediments), allow us to conclude that LLP content in sea urchin NPs can not be used as a biomarker in marine pollution monitoring.

  18. Simultaneous in vivo imaging of melanin and lipofuscin in the retina with multimodal photoacoustic ophthalmoscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangyang; Zhang, Hao F.; Zhou, Lixiang; Jiao, Shuliang

    2012-02-01

    We combined photoacoustic ophthalmoscopy (PAOM) with autofluorescence imaging for simultaneous in vivo imaging of dual molecular contrasts in the retina using a single light source. The dual molecular contrasts come from melanin and lipofuscin in the retinal pigment epithelium (RPE). Melanin and lipofuscin are two types of pigments and are believed to play opposite roles (protective vs. exacerbate) in the RPE in the aging process. We successfully imaged the retina of pigmented and albino rats at different ages. The experimental results showed that multimodal PAOM system can be a potentially powerful tool in the study of age-related degenerative retinal diseases.

  19. Reduction of lipofuscin-like autofluorescence in fluorescently labeled tissue.

    PubMed

    Schnell, S A; Staines, W A; Wessendorf, M W

    1999-06-01

    The fluorescent pigment lipofuscin accumulates with age in the cytoplasm of cells of the CNS. Because of its broad excitation and emission spectra, the presence of lipofuscin-like autofluorescence complicates the use of fluorescence microscopy (e.g., fluorescent retrograde tract tracing and fluorescence immunocytochemistry). In this study we examined several chemical treatments of tissue sections for their ability to reduce or eliminate lipofuscin-like autofluorescence without adversely affecting other fluorescent labels. We found that 1-10 mM CuSO4 in 50 mM ammonium acetate buffer (pH 5) or 1% Sudan Black B (SB) in 70% ethanol reduced or eliminated lipofuscin autofluorescence in sections of monkey, human, or rat neural tissue. These treatments also slightly reduced the intensity of immunofluorescent labeling and fluorescent retrograde tract tracers. However, the reduction of these fluorophores was far less dramatic than that for the lipofuscin-like compound. We conclude that treatment of tissue with CuSO4 or SB provides a reasonable compromise between reduction of lipofuscin-like fluorescence and maintenance of specific fluorescent labels.

  20. Simultaneous in vivo imaging of melanin and lipofuscin in the retina with photoacoustic ophthalmoscopy and autofluorescence imaging

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangyang; Zhang, Hao F.; Puliafito, Carmen A.; Jiao, Shuliang

    2011-08-01

    We combined photoacoustic ophthalmoscopy (PAOM) with autofluorescence imaging for simultaneous in vivo imaging of dual molecular contrasts in the retina using a single light source. The dual molecular contrasts come from melanin and lipofuscin in the retinal pigment epithelium (RPE). Melanin and lipofuscin are two types of pigments and are believed to play opposite roles (protective versus exacerbate) in the RPE in the aging process. We have successfully imaged the retina of pigmented and albino rats at different ages. The experimental results showed that multimodal PAOM system can be a potentially powerful tool in the study of age-related degenerative retinal diseases.

  1. Estradiol Modulates Membrane-Linked ATPases, Antioxidant Enzymes, Membrane Fluidity, Lipid Peroxidation, and Lipofuscin in Aged Rat Liver

    PubMed Central

    Kumar, Pardeep; Kale, R. K.; Baquer, Najma Zaheer

    2011-01-01

    Free radical production and oxidative stress are known to increase in liver during aging, and may contribute to the oxidative damage. These changes increase during menopausal condition in females when the level of estradiol is decreased. The objective of this study was to observe the changes in activities of membrane linked ATPases (Na+K+ ATPase, Ca2+ ATPase), antioxidant enzymes (superoxide dismutase, glutathione-S-transferase), lipid peroxidation levels, lipofuscin content and membrane fluidity occurring in livers of female rats of 3, 12 and 24 months age groups, and to see whether these changes are restored to 3 months control levels rats after exogenous administration of 17-β-estradiol (E2). The aged rats (12 and 24 months) were given subcutaneous injection of E2 (0.1 μg/g body weight) daily for one month. The results obtained in the present work revealed that normal aging was associated with significant decrease in the activities of membrane linked ATPases, antioxidant enzymes, membrane fluidity and an increase in lipid peroxidation and lipofuscin content in livers of aging female rats. The present study showed that E2 treatment reversed the changes to normal levels. E2 treatment may be beneficial in preventing some of the age related changes in the liver by increasing antioxidant defenses. PMID:22007298

  2. The utilization of fluorescence to identify the components of lipofuscin by imaging mass spectrometry

    PubMed Central

    Ablonczy, Zsolt; Smith, Noah; Anderson, David M; Grey, Angus C.; Spraggins, Jeffrey; Koutalos, Yiannis; Schey, Kevin L.; Crouch, Rosalie K.

    2014-01-01

    Lipofuscin, an aging marker in the retinal pigment epithelium (RPE) associated with the development of age-related macular degeneration, is primarily characterized by its fluorescence. The most abundant component of RPE lipofuscin is N-retinylidene-N-retinylethanolamine (A2E) but its exact composition is not known due to the complexity of the RPE extract. In this study, we utilized MALDI imaging to find potential molecules responsible for lipofuscin fluorescence in RPE tissue from Abca4−/−, Sv129, and C57Bl6/J mice ages 2 and 6 month. To assert relationships, the individual images in the MALDI imaging datasets were correlated with lipofuscin fluorescence recorded from the same tissues following proper registration. Spatial correlation information, which is usually is lost in bioanalytics, pinpointed a relatively small number of potential lipofuscin components. The comparison of four samples in each condition further limited the possibility of false positives and provided various new, age- and strain-specific targets. Validating the usefulness of the fluorescence-enhanced imaging strategy, many known adducts of A2E were identified in the short list of lipofuscin components. These results provided evidence that mass spectrometric imaging can be utilized as a tool to begin to identify the molecular substructure of clinically-relevant diagnostic information. PMID:24453194

  3. Lipofuscins prepared by modification of photoreceptor cells via glycation or lipid peroxidation show the similar phototoxicity

    PubMed Central

    Dontsov, Alexander; Koromyslova, Anna; Ostrovsky, Mikhail; Sakina, Natalia

    2016-01-01

    AIM To investigate the effect of two ways of lipofuscin production (lipid peroxidation and glycation) on lipofuscin fluorescence characteristics and phototoxicity and to compare them with the properties of natural lipofuscin. METHODS Model lipofuscins were prepared on the basis of bovine photoreceptor outer segments (POS) with bisretinoid A2E addition. One set of samples was prepared from POS modified by lipid peroxidation, while another set from POS modified by glycation with fructose. Fluorescent properties and kinetics of photoinduced superoxide generation of model lipofuscins and human retinal pigment epithelium (RPE) lipofuscin were compared. The fluorescence spectra of samples were measured at 365 nm excitation wavelength and 380-650 emission wavelength. RESULTS The fluorescence spectra of model lipofuscins are almost the same as the spectrum of natural lipofuscin. Visible light irradiation of both model lipofuscins and natural lipofuscin isolated from RPE cells leads to decrease of a fluorescence maximum at 550 nm and to appearance of a distinct, new maximum at 445-460 nm. The rate of photogeneration of reactive oxygen forms by both model lipofuscins was almost the same and approximately two times less than that of RPE lipofuscin granules. CONCLUSION These data suggest that fluorescent characteristics and phototoxicity of lipofuscin granules depend only to an insignificant degree on the oxidative modification of POS proteins and lipids, and generally are defined by the bisretinoid fluorophores contained in them. PMID:27909686

  4. Quantification of Ceroid and Lipofuscin in Skeletal Muscle

    PubMed Central

    Tohma, Hatice; Hepworth, Anna R.; Shavlakadze, Thea; Grounds, Miranda D.; Arthur, Peter G.

    2011-01-01

    Ceroid and lipofuscin are autofluorescent granules thought to be generated as a consequence of chronic oxidative stress. Because ceroid and lipofuscin are persistent in tissue, their measurement can provide a lifetime history of exposure to chronic oxidative stress. Although ceroid and lipofuscin can be measured by quantification of autofluorescent granules, current methods rely on subjective assessment. Furthermore, there has not been any evaluation of variables affecting quantitative measurements. The article describes a simple statistical approach that can be readily applied to quantitate ceroid and lipofuscin. Furthermore, it is shown that several factors, including magnification tissue thickness and tissue level, can affect precision and sensitivity. After optimizing for these factors, the authors show that ceroid and lipofuscin can be measured reproducibly in the skeletal muscle of dystrophic mice (ceroid) and aged mice (lipofuscin). PMID:21804079

  5. Advanced glycosylation end products in adrenal lipofuscin.

    PubMed

    Shimokawa, I; Higami, Y; Horiuchi, S; Iwasaki, M; Ikeda, T

    1998-01-01

    The present study examined the presence of advanced glycosylation end products (AGEs) in lipofuscin present in the brain and adrenal gland of aging rats by immunohistochemistry using antibodies raised against AGEs. Lipofuscin identified as yellow to brown granules emitting bright yellow to orange autofluorescence with ultraviolet light were detected in cortical neurons, cerebellar Purkinje cells, and adrenal cells in the inner part of the zona reticularis. However, none of the antibodies visualized lipofuscin in these areas. The outer part of the zona reticularis contained yellow granules emitting a faint orange autofluorescence. These granules were immunostained by an antibody that reacted with AGEs structures unrelated to the carboxymethyllysine moiety. Newly formed adrenal cortical cells are thought to migrate from the outer layer to the inner layer of the zona reticularis. Therefore, our results suggest that glycosylation-related processes are involved in lipofuscinogenesis, at least in its early stage, in the adrenal zona reticularis.

  6. The melanins and lipofuscin.

    PubMed

    Hack, M H; Helmy, F M

    1983-01-01

    An overview of the melanins and lipofuscin is presented, taking an integrating account of their morphological relationships and chemical characteristics wherever possible. This has required inclusion of the ommochromes, the schlerotizing process, and consideration of related neurotransmitters. A number of questions are raised and commented upon.

  7. β-Secretase (BACE1) inhibition causes retinal pathology by vascular dysregulation and accumulation of age pigment.

    PubMed

    Cai, Jun; Qi, Xiaoping; Kociok, Norbert; Skosyrski, Sergej; Emilio, Alonso; Ruan, Qing; Han, Song; Liu, Li; Chen, Zhijuan; Bowes Rickman, Catherine; Golde, Todd; Grant, Maria B; Saftig, Paul; Serneels, Lutgarde; de Strooper, Bart; Joussen, Antonia M; Boulton, Michael E

    2012-09-01

    β-Secretase (BACE1) is a major drug target for combating Alzheimer's disease (AD). Here we show that BACE1(-/-) mice develop significant retinal pathology including retinal thinning, apoptosis, reduced retinal vascular density and an increase in the age pigment, lipofuscin. BACE1 expression is highest in the neural retina while BACE2 was greatest in the retinal pigment epithelium (RPE)/choroid. Pigment epithelial-derived factor, a known regulator of γ-secretase, inhibits vascular endothelial growth factor (VEGF)-induced in vitro and in vivo angiogenesis and this is abolished by BACE1 inhibition. Moreover, intravitreal administration of BACE1 inhibitor or BACE1 small interfering RNA (siRNA) increases choroidal neovascularization in mice. BACE1 induces ectodomain shedding of vascular endothelial growth factor receptor 1 (VEGFR1) which is a prerequisite for γ-secretase release of a 100 kDa intracellular domain. The increase in lipofuscin following BACE1 inhibition and RNAI knockdown is associated with lysosomal perturbations. Taken together, our data show that BACE1 plays a critical role in retinal homeostasis and that the use of BACE inhibitors for AD should be viewed with extreme caution as they could lead to retinal pathology and exacerbate conditions such as age-related macular degeneration.

  8. Lipofuscin: formation, effects and role of macroautophagy☆

    PubMed Central

    Höhn, Annika; Grune, Tilman

    2013-01-01

    Oxidative stress plays a crucial role in the development of the aging process and age dependent diseases. Both are closely connected to disturbances of proteostasis by protein oxidation and an impairment of the proteasomal system. The final consequence is the accumulation of highly cross-linked undegradable aggregates such as lipofuscin. These aggregates of damaged proteins are detrimental to normal cell functions. Here we provide an overview about effect of these aggregates on the proteasomal system, followed by transcription factor activation and loss of cell viability. Furthermore, findings on the mechanism of radical genesis, proteasomal inhibition and the required components of lipofuscin formation were resumed. PMID:24024146

  9. Lipofuscin-associated photo-oxidative stress during fundus autofluorescence imaging

    PubMed Central

    Teussink, Michel M.; Lambertus, Stanley; de Mul, Frits F.; Rozanowska, Malgorzata B.; Hoyng, Carel B.; Klevering, B. Jeroen; Theelen, Thomas

    2017-01-01

    Purpose Current standards and guidelines aimed at preventing retinal phototoxicity during intentional exposures do not specifically evaluate the contribution of endogenous photosensitizers. However, certain retinal diseases are characterized by abnormal accumulations of potential photosensitizers such as lipofuscin bisretinoids in the retinal pigment epithelium (RPE). We sought to determine these contributions by a numerical assessment of in-vivo photo-oxidative stress during irradiation of RPE lipofuscin. Methods Based on the literature, we calculated the retinal exposure levels, optical filtering of incident radiation by the ocular lens, media, photoreceptors, and RPE melanin, light absorption by lipofuscin, and photochemical effects in the RPE in two situations: exposure to short-wavelength (λ = 488 nm) fundus autofluorescence (SW-AF) excitation light and exposure to indirect (diffuse) sunlight. Results In healthy persons at age 20, 40, and 60, respectively, the rate of oxygen photoconsumption by lipofuscin increases by 1.3, 1.7, and 2.4 fold during SW-AF-imaging as compared to diffuse sunlight. In patients with STGD1 below the age of 30, this rate was 3.3-fold higher compared to age-matched controls during either sunlight or SW-AF imaging. Conclusions Our results suggest that the RPE of patients with STGD1 is generally at increased risk of photo-oxidative stress, while exposure during SW-AF-imaging amplifies this risk. These theoretical results have not yet been verified with in-vivo data due to a lack of sufficiently sensitive in-vivo measurement techniques. PMID:28235055

  10. Conditional ablation of the choroideremia gene causes age-related changes in mouse retinal pigment epithelium.

    PubMed

    Wavre-Shapton, Silène T; Tolmachova, Tanya; Lopes da Silva, Mafalda; da Silva, Mafalda Lopes; Futter, Clare E; Seabra, Miguel C

    2013-01-01

    The retinal pigment epithelium (RPE) is a pigmented monolayer of cells lying between the photoreceptors and a layer of fenestrated capillaries, the choriocapillaris. Choroideremia (CHM) is an X-linked progressive degeneration of these three layers caused by the loss of function of Rab Escort protein-1 (REP1). REP1 is involved in the prenylation of Rab proteins, key regulators of membrane trafficking. To study the pathological consequences of chronic disruption of membrane traffic in the RPE we used a cell type-specific knock-out mouse model of the disease, where the Chm/Rep1 gene is deleted only in pigmented cells (Chm(Flox), Tyr-Cre+). Transmission electron microscopy (TEM) was used to quantitate the melanosome distribution in the RPE and immunofluorescent staining of rhodopsin was used to quantitate phagocytosed rod outer segments in retinal sections. The ultrastructure of the RPE and Bruch's membrane at different ages was characterised by TEM to analyse age-related changes occurring as a result of defects in membrane traffic pathways. Chm/Rep1 gene knockout in RPE cells resulted in reduced numbers of melanosomes in the apical processes and delayed phagosome degradation. In addition, the RPE accumulated pathological changes at 5-6 months of age similar to those observed in 2-year old controls. These included the intracellular accumulation of lipofuscin-containing deposits, disorganised basal infoldings and the extracellular accumulation of basal laminar and basal linear deposits. The phenotype of the Chm(Flox), Tyr-Cre+ mice suggests that loss of the Chm/Rep1 gene causes premature accumulation of features of aging in the RPE. Furthermore, the striking similarities between the present observations and some of the phenotypes reported in age-related macular degeneration (AMD) suggest that membrane traffic defects may contribute to the pathogenesis of AMD.

  11. Age and disease-related structural changes in the retinal pigment epithelium

    PubMed Central

    Bonilha, Vera L

    2008-01-01

    As the retinal pigment epithelium (RPE) ages, a number of structural changes occur, including loss of melanin granules, increase in the density of residual bodies, accumulation of lipofuscin, accumulation of basal deposits on or within Bruch’s membrane, formation of drusen (between the basal lamina of the RPE and the inner collagenous layer of Bruch’s membrane), thickening of Bruch’s membrane, microvilli atrophy and disorganization of the basal infoldings. Although these changes are well known, the basic mechanisms involved in them are frequently poorly understood. These age-related changes progress slowly and vary in severity in different individuals. These changes are also found in age-related macular degeneration (AMD), a late onset disease that severely impacts the RPE, but they are much more pronounced than during normal aging. However, the changes in AMD lead to severe loss of vision. Given the many supporting functions which the RPE serves for the retina, it is important to decipher the age-related changes in this epithelium in order to understand age-related changes in vision. PMID:19668732

  12. Sequential histochemical studies of neuronal lipofuscin in human cerebral cortex from the first to the ninth decade of life.

    PubMed

    Benavides, Sebastián H; Monserrat, Alberto J; Fariña, Silvia; Porta, Eduardo A

    2002-01-01

    The typical and most consistent physico-histochemical properties of lipofuscin granules, such as autofluorescence, sudanophilia, acid-fastness, PAS-reactivity, and lectin reactivities for diverse saccharide moieties have been generally detected in tissue specimens of old humans and animals. The purpose of this study was, therefore, to explore possible sequential variations of each of these properties in cortical neurons of the left cerebral temporo-parietal areas from individuals dying from the first to the ninth decade. Autofluorescence was studied with an ad hoc equipped microscope, sudanophilia was evaluated by Oil-red-O (ORO) staining, acid-fastness by long Ziehl-Nielsen reagent, PAS reactivity by the periodic-acid-Schiff reagent before and after diastase treatment, and the saccharide moieties by the use of a commercial kit of seven different biotinylated lectins. In the specimen from a 5-year-old child, lipofuscin granules were detected in less than 5% of the cortical neurons, but these granules already showed golden-yellow autofluorescence, sudanophilia, acid-fastness and PAS-reactivity. From the second to the ninth decade of life, perikaryal lipofuscin granules were found in practically all cortical neurons with apparent agewise increases in the intensity of sudanophilia and PAS-reactivity, but with variable acid-fastness expression. Surprisingly, however, no saccharide residues were detected by lectin histochemistry before the fifth decade of life. First detected saccharide was mannose in specimens from the fifth decade of life, and at later decades acetyl galactosamine, sialic acid and lactose were also found. Although, the reasons for the absence of lipofuscin affinity for the seven lectins used in this study in the cortical neurons of young and middle-aged individuals are presently unknown, these unexpected findings suggested important evolutionary changes of biogenesis and composition of the age-pigment.

  13. Diet-derived advanced glycation end products or lipofuscin disrupts proteostasis and reduces life span in Drosophila melanogaster.

    PubMed

    Tsakiri, Eleni N; Iliaki, Kalliopi K; Höhn, Annika; Grimm, Stefanie; Papassideri, Issidora S; Grune, Tilman; Trougakos, Ioannis P

    2013-12-01

    Advanced glycation end product (AGE)-modified proteins are formed by the nonenzymatic glycation of free amino groups of proteins and, along with lipofuscin (a highly oxidized aggregate of covalently cross-linked proteins, sugars, and lipids), have been found to accumulate during aging and in several age-related diseases. As the in vivo effects of diet-derived AGEs or lipofuscin remain elusive, we sought to study the impact of oral administration of glucose-, fructose-, or ribose-modified albumin or of artificial lipofuscin in a genetically tractable model organism. We report herein that continuous feeding of young Drosophila flies with culture medium enriched in AGEs or in lipofuscin resulted in reduced locomotor performance and in accelerated rates of AGE-modified proteins and carbonylated proteins accumulation in the somatic tissues and hemolymph of flies, as well as in a significant reduction of flies health span and life span. These phenotypic effects were accompanied by reduced proteasome peptidase activities in both the hemolymph and the somatic tissues of flies and higher levels of oxidative stress; furthermore, oral administration of AGEs or lipofuscin in flies triggered an upregulation of the lysosomal cathepsin B, L activities. Finally, RNAi-mediated cathepsin D knockdown reduced flies longevity and significantly augmented the deleterious effects of AGEs and lipofuscin, indicating that lysosomal cathepsins reduce the toxicity of diet-derived AGEs or lipofuscin. Our in vivo studies demonstrate that chronic ingestion of AGEs or lipofuscin disrupts proteostasis and accelerates the functional decline that occurs with normal aging.

  14. Lipofuscin

    MedlinePlus

    Kumar V, Abbas AK, Aster JC. Cellular responses to stress and toxic insults: Adaptation, injury, and death. In: Kumar V, Abbas AK, Aster JC, eds. Robbins and Cotran Pathologic Basis of Disease . 9th ed. Philadelphia, PA: ...

  15. Statistical physics of age related macular degeneration

    NASA Astrophysics Data System (ADS)

    Family, Fereydoon; Mazzitello, K. I.; Arizmendi, C. M.; Grossniklaus, H. E.

    Age-related macular degeneration (AMD) is the leading cause of blindness beyond the age of 50 years. The most common pathogenic mechanism that leads to AMD is choroidal neovascularization (CNV). CNV is produced by accumulation of residual material caused by aging of retinal pigment epithelium cells (RPE). The RPE is a phagocytic system that is essential for renewal of photoreceptors (rods and cones). With time, incompletely degraded membrane material builds up in the form of lipofuscin. Lipofuscin is made of free-radical-damaged protein and fat, which forms not only in AMD, but also Alzheimer disease and Parkinson disease. The study of lipofuscin formation and growth is important, because of their association with cellular aging. We introduce a model of non-equilibrium cluster growth and aggregation that we have developed for studying the formation and growth of lipofuscin in the aging RPE. Our results agree with a linear growth of the number of lipofuscin granules with age. We apply the dynamic scaling approach to our model and find excellent data collapse for the cluster size distribution. An unusual feature of our model is that while small particles are removed from the RPE the larger ones become fixed and grow by aggregation.

  16. Elovl4 5-bp deletion knock-in mouse model for Stargardt-like macular degeneration demonstrates accumulation of ELOVL4 and lipofuscin

    PubMed Central

    Vasireddy, Vidyullatha; Jablonski, Monica M.; Khan, Naheed W.; Wang, Xiao Fei; Sahu, Priya; Sparrow, Janet R; Ayyagari, Radha

    2009-01-01

    The mechanism underlying photoreceptor degeneration in autosomal dominant Stargardt like macular degeneration (STGD3) due to mutations in the elongation of very long chain fatty acids-4 (ELOVL4) gene is not fully understood. To evaluate the pathological events associated with STGD3, we used a mouse model that mimics the human STGD3 phenotype and studied the progression of retinal degeneration. Morphological changes in the retina of Elovl4 5 bp-deletion knock-in mice (E_mut+/− ) were evaluated at 22 months of age. The localization of ELOVL4, and the expression pattern of inner retinal tissue marker proteins, and ubiquitin were determined by immunofluorescence labeling of retinal sections. Levels of the retinal pigment epithelium (RPE) lipofuscin fluorophores were measured by quantitative HPLC. Morphological evaluation of the retina revealed an accumulation of RPE debris in the subretinal space. A significant increase in the amount of ELOVL4 was observed in the outer plexiform layer in E_mut +/− mice compared to controls. Apart from the accumulation of ELOVL4, E_mut +/− mice also exhibited high expression of ubiquitin in the retina. Analysis of lipofuscin fluorophores in the RPE showed a significant elevation of A2E and compounds of the all-trans- retinal dimer series in retinas from four and ten month old E_mut +/− mice compared to wild-type littermates. These observations suggest that abnormal accumulation of ELOVL4 protein and lipofuscin may lead to photoreceptor degeneration in E_mut +/− mice. PMID:19682985

  17. Effects of increasing numbers of phagocytic inclusions on human retinal pigment epithelial cells in culture: a model for aging.

    PubMed Central

    Boulton, M; Marshall, J

    1986-01-01

    Cultures of human retinal pigment epithelial cells have been challenged with a number of biological (lipofuscin, melanin, and rod outer segments) and non-biological (latex microspheres) particles at a variety of concentrations. The particles were chosen to include examples of both degradable and non-degradable systems. A range of morphological changes were observed by phase contrast microscopy, and these became more atypical with increasing concentration. At the highest concentration cells had ingested so many particles that many had died and others had ruptured. The time course of these changes indicated a relationship between cellular lytic activity and the capacity of the particle to degrade. The potential of this system as a model for studying senescence is discussed. Images PMID:3790481

  18. Physics of Age Related Macular Degeneration

    NASA Astrophysics Data System (ADS)

    Family, Fereydoon

    2009-11-01

    Age-related macular degeneration (AMD) is the leading cause of blindness beyond the age of 50 years. The most common pathogenic mechanism that leads to AMD is choroidal neovascularization (CNV). CNV is produced by accumulation of residual material caused by aging of retinal pigment epithelium cells (RPE). The RPE is a phagocytic system that is essential for renewal of photoreceptors (rods and cones). With time, incompletely degraded membrane material builds up in the form of lipofuscin. Lipofuscin is made of free-radical-damaged protein and fat, which forms not only in AMD, but also Alzheimer's disease, and Parkinson's disease. The study of lipofuscin formation and growth is important, because of their association with cellular aging. In this talk I will discuss a model of non-equilibrium cluster growth that we have developed for studying the formation and growth of lipofuscin in AMD [K.I. Mazzitello, C.M. Arizmendi, Fereydoon Family, H. E. Grossniklaus, Physical Review E (2009)]. I will also present an overview of our theoretical and computational efforts in modeling some other aspects of the physics of AMD, including CNV and the breakdown of Bruch's membrane [Ongoing collaboration with Abbas Shirinifard and James A. Glazier, Biocomplexity Institute and Department of Physics, Indiana University, Y. Jiang, Los Alamos, and Hans E. Grossniklaus, Department of Ophthalmology, Emory University].

  19. C20-D3-vitamin A Slows Lipofuscin Accumulation and Electrophysiological Retinal Degeneration in a Mouse Model of Stargardt Disease*

    PubMed Central

    Ma, Li; Kaufman, Yardana; Zhang, Junhua; Washington, Ilyas

    2011-01-01

    Stargardt disease, also known as juvenile macular degeneration, occurs in approximately one in 10,000 people and results from genetic defects in the ABCA4 gene. The disease is characterized by premature accumulation of lipofuscin in the retinal pigment epithelium (RPE) of the eye and by vision loss. No cure or treatment is available. Although lipofuscin is considered a hallmark of Stargardt disease, its mechanism of formation and its role in disease pathogenesis are poorly understood. In this work we investigated the effects of long-term administration of deuterium-enriched vitamin A, C20-D3-vitamin A, on RPE lipofuscin deposition and eye function in a mouse model of Stargardt's disease. Results support the notion that lipofuscin forms partly as a result of the aberrant reactivity of vitamin A through the formation of vitamin A dimers, provide evidence that preventing vitamin A dimerization may slow disease related, retinal physiological changes and perhaps vision loss and suggest that administration of C20-D3-vitamin A may be a potential clinical strategy to ameliorate clinical symptoms resulting from ABCA4 genetic defects. PMID:21156790

  20. Complement system dysregulation and inflammation in the retinal pigment epithelium of a mouse model for Stargardt macular degeneration.

    PubMed

    Radu, Roxana A; Hu, Jane; Yuan, Quan; Welch, Darcy L; Makshanoff, Jacob; Lloyd, Marcia; McMullen, Stephen; Travis, Gabriel H; Bok, Dean

    2011-05-27

    Accumulation of vitamin A-derived lipofuscin fluorophores in the retinal pigment epithelium (RPE) is a pathologic feature of recessive Stargardt macular dystrophy, a blinding disease caused by dysfunction or loss of the ABCA4 transporter in rods and cones. Age-related macular degeneration, a prevalent blinding disease of the elderly, is strongly associated with mutations in the genes for complement regulatory proteins (CRP), causing chronic inflammation of the RPE. Here we explore the possible relationship between lipofuscin accumulation and complement activation in vivo. Using the abca4(-/-) mouse model for recessive Stargardt, we investigated the role of lipofuscin fluorophores (A2E-lipofuscin) on oxidative stress and complement activation. We observed higher expression of oxidative-stress genes and elevated products of lipid peroxidation in eyes from abca4(-/-) versus wild-type mice. We also observed higher levels of complement-activation products in abca4(-/-) RPE cells. Unexpectedly, expression of multiple CRPs, which protect cells from attack by the complement system, were lower in abca4(-/-) versus wild-type RPE. To test whether acute exposure of healthy RPE cells to A2E-lipofuscin affects oxidative stress and expression of CRPs, we fed cultured fetal-derived human RPE cells with rod outer segments from wild-type or abca4(-/-) retinas. In contrast to RPE cells in abca4(-/-) mice, human RPE cells exposed to abca4(-/-) rod outer segments adaptively increased expression of both oxidative-stress and CRP genes. These results suggest that A2E accumulation causes oxidative stress, complement activation, and down-regulation of protective CRP in the Stargardt mouse model. Thus, Stargardt disease and age-related macular degeneration may both be caused by chronic inflammation of the RPE.

  1. Pigment Deposition in the Rat Retina.

    PubMed

    Hojman, Anne S; Otzen, Louise W D; Schrøder-Hansen, Lise Maj; Wegener, Karen M

    2015-08-01

    Incidental findings in the rat eye are not uncommon in acute and long-term toxicological studies. These findings can be associated with a number of causes unrelated to treatment with the test article, including congenital malformation, trauma, infection, metabolic disease, genetic predisposition, and age-related changes. The occurrence of pigment deposition in the retina of Wistar Hannover (Crl:WI (Han)) rats in a 4-week toxicity study is reported in this communication. The microscopic examination of the eyes in the 4-week toxicity study revealed focal yellow-brown pigment deposits in the retina, mainly located in the ganglion cell layer. The retinal pigment deposits were randomly distributed in the control and treated groups and were considered incidental. The deposits were clearly positive for ferric iron in the Perls' stain but not for lipofuscin by the Schmorl's and Long Ziehl-Neelsen methods. The iron-containing pigment is likely to represent hemosiderin accumulation after retinal micro-hemorrhage or could be indicative of the normal intraretinal iron transport and turnover.

  2. Color stability of maxillofacial silicone with nanoparticle pigment and opacifier submitted to disinfection and artificial aging

    NASA Astrophysics Data System (ADS)

    Filié Haddad, Marcela; Coelho Goiato, Marcelo; Micheline Dos Santos, Daniela; Moreno, Amália; Filipe D'Almeida, Nuno; Alves Pesqueira, Aldiéris

    2011-09-01

    The purpose of this study was to evaluate the color stability of a maxillofacial elastomer with the addition of a nanoparticle pigment and/or an opacifier submitted to chemical disinfection and artificial aging. Specimens were divided into four groups (n = 30): group I: silicone without pigment or opacifier, group II: ceramic powder pigment, group III: Barium sulfate (BaSO4) opacifier, and group IV: ceramic powder and BaSO4 opacifier. Specimens of each group (n = 10) were disinfected with effervescent tablets, neutral soap, or 4% chlorhexidine gluconate. Disinfection was done three times a week during two months. Afterward, specimens were submitted to different periods of artificial aging. Color evaluation was initially done, after 60 days (disinfection period) and after 252, 504, and 1008 h of artificial aging with aid of a reflection spectrophotometer. Data were analyzed by three-way ANOVA and Tukey test (α = 0.05). The isolated factor disinfection did not statistically influence the values of color stability among groups. The association between pigment and BaSO4 opacifier (GIV) was more stable in relationship to color change (▵E). All values of ▵E obtained, independent of the disinfectant and the period of artificial aging, were considered acceptable in agreement with the norms presented in literature.

  3. Color stability of maxillofacial silicone with nanoparticle pigment and opacifier submitted to disinfection and artificial aging.

    PubMed

    Filié Haddad, Marcela; Coelho Goiato, Marcelo; Micheline Dos Santos, Daniela; Moreno, Amália; Filipe D'almeida, Nuno; Alves Pesqueira, Aldiéris

    2011-09-01

    The purpose of this study was to evaluate the color stability of a maxillofacial elastomer with the addition of a nanoparticle pigment and∕or an opacifier submitted to chemical disinfection and artificial aging. Specimens were divided into four groups (n = 30): group I: silicone without pigment or opacifier, group II: ceramic powder pigment, group III: Barium sulfate (BaSO(4)) opacifier, and group IV: ceramic powder and BaSO(4) opacifier. Specimens of each group (n = 10) were disinfected with effervescent tablets, neutral soap, or 4% chlorhexidine gluconate. Disinfection was done three times a week during two months. Afterward, specimens were submitted to different periods of artificial aging. Color evaluation was initially done, after 60 days (disinfection period) and after 252, 504, and 1008 h of artificial aging with aid of a reflection spectrophotometer. Data were analyzed by three-way ANOVA and Tukey test (α = 0.05). The isolated factor disinfection did not statistically influence the values of color stability among groups. The association between pigment and BaSO(4) opacifier (GIV) was more stable in relationship to color change (△E). All values of △E obtained, independent of the disinfectant and the period of artificial aging, were considered acceptable in agreement with the norms presented in literature.

  4. Key Regulatory Role of Dermal Fibroblasts in Pigmentation as Demonstrated Using a Reconstructed Skin Model: Impact of Photo-Aging

    PubMed Central

    Duval, Christine; Cohen, Catherine; Chagnoleau, Corinne; Flouret, Virginie; Bourreau, Emilie; Bernerd, Françoise

    2014-01-01

    To study cutaneous pigmentation in a physiological context, we have previously developed a functional pigmented reconstructed skin model composed of a melanocyte-containing epidermis grown on a dermal equivalent comprising living fibroblasts. The present studies, using the same model, aimed to demonstrate that dermal fibroblasts influence skin pigmentation up to the macroscopic level. The proof of principle was performed with pigmented skins differing only in the fibroblast component. First, the in vitro system was reconstructed with or without fibroblasts in order to test the global influence of the presence of this cell type. We then assessed the impact of the origin of the fibroblast strain on the degree of pigmentation using fetal versus adult fibroblasts. In both experiments, impressive variation in skin pigmentation at the macroscopic level was observed and confirmed by quantitative parameters related to skin color, melanin content and melanocyte numbers. These data confirmed the responsiveness of the model and demonstrated that dermal fibroblasts do indeed impact the degree of skin pigmentation. We then hypothesized that a physiological state associated with pigmentary alterations such as photo-aging could be linked to dermal fibroblasts modifications that accumulate over time. Pigmentation of skin reconstructed using young unexposed fibroblasts (n = 3) was compared to that of tissues containing natural photo-aged fibroblasts (n = 3) which express a senescent phenotype. A stimulation of pigmentation in the presence of the natural photo-aged fibroblasts was revealed by a significant increase in the skin color (decrease in Luminance) and an increase in both epidermal melanin content and melanogenic gene expression, thus confirming our hypothesis. Altogether, these data demonstrate that the level of pigmentation of the skin model is influenced by dermal fibroblasts and that natural photo-aged fibroblasts can contribute to the hyperpigmentation that is

  5. Pigmented central neurocytoma.

    PubMed

    Kiehl, Tim-Rasmus; Kalkanis, Steven N; Louis, David N

    2004-06-01

    Central neurocytoma is a low-grade neuronal neoplasm that occurs most often within the lateral ventricles. We report the case of a 60-year-old woman who presented with gait problems, headache and memory loss. Preoperative evaluation demonstrated a heterogeneous, hypervascular and partially cystic mass in the left lateral ventricle. Histopathological examination revealed characteristic features of central neurocytoma, including immunoreactivity for synaptophysin, as well as the unusual feature of abundant pigment in the cytoplasm of tumor cells. Special stains revealed iron, consistent with hemosiderin, but found no evidence of melanin or melanosomes. Previous reports of pigmented central neurocytoma have described the presence of lipofuscin or neuromelanin. To our knowledge, the present case represents the first example of pigmented central neurocytoma secondary to hemosiderin deposition.

  6. Macular pigment density measured by autofluorescence spectrometry: comparison with reflectometry and heterochromatic flicker photometry.

    PubMed

    Delori, F C; Goger, D G; Hammond, B R; Snodderly, D M; Burns, S A

    2001-06-01

    We present a technique for estimating the density of the human macular pigment noninvasively that takes advantage of the autofluorescence of lipofuscin, which is normally present in the human retinal pigment epithelium. By measuring the intensity of fluorescence at 710 nm, where macular pigment has essentially zero absorption, and stimulating the fluorescence with two wavelengths, one well absorbed by macular pigment and the other minimally absorbed by macular pigment, we can make accurate single-pass measurements of the macular pigment density. We used the technique to measure macular pigment density in a group of 159 subjects with normal retinal status ranging in age between 15 and 80 years. Average macular pigment density was 0.48 +/- 0.16 density unit (D.U.) for a 2 degrees -diameter test field. We show that these estimates are highly correlated with reflectometric (mean: 0.23 +/- 0.07 D.U.) and psychophysical (mean: 0.37 +/- 0.26 D.U.; obtained by heterochromatic flicker photometry) estimates of macular pigment in the same subjects, despite the fact that systematic differences in the estimated density exist between techniques. Repeat measurements over both short- and long-time intervals indicate that the autofluorescence technique is reproducible: The mean absolute difference between estimates was less than 0.05 D.U., superior to the reproducibility obtained by reflectometry and flicker photometry. To understand the systematic differences between density estimates obtained from the different methods, we analyzed the underlying assumptions of each technique. Specifically, we looked at the effect of self-screening by visual pigment, the effect of changes in optical property of the deeper retinal layers, including the role of retinal pigmented epithelium melanin, and the role of secondary fluorophores and reflectors in the anterior layers of the retina.

  7. AGEs Promote Oxidative Stress and Induce Apoptosis in Retinal Pigmented Epithelium Cells RAGE-dependently.

    PubMed

    Wang, Xin-Ling; Yu, Tao; Yan, Qi-Chang; Wang, Wei; Meng, Nan; Li, Xue-Jiao; Luo, Ya-Hong

    2015-06-01

    Advanced glycation end products (AGEs) are extremely accumulated in diabetes mellitus, particularly in retinal vascular and epithelium cells, and are confirmed to contribute to diabetic retinopathy (DR). In the present study, we determined the promotion by AGEs to the oxidative stress and mitochondrial dysfunction in retinal pigmented epithelium ARPE-19 cells and investigated the influence by the knockdown or the overexpression of receptor for AGEs (RAGE) on the AGE-promoted oxidative stress and mitochondrial dysfunction. Furthermore, we determined the induction by AGEs to the cell apoptosis and to the activation of B-cell lymphoma 2 (Bcl-2) families in the AGE-BSA-induced apoptosis, and examined the RAGE-dependence in such induction. Results demonstrated that AGE-BSA upregulated the hydrogen peroxide production and induced mitochondrial dysfunction in ARPE-19 cells, dose-dependently. And the further investigation indicated that the AGE-RAGE interaction was required for the induction of oxidative stress and mitochondrial dysfunction. Moreover, the AGE-BSA treatment promoted a significantly high level of apoptotic cells, and the Bcl-2 family was implicated in the AGE-BSA-induced apoptosis, there was a significant high level of Cyt c release, Bcl-2-associated X protein (Bax) induction, Bcl-2 reduction, and caspase 9 activation in the AGE-BSA-treated cells. In conclusion, the present study recognized the apoptosis induction by AGE-BSAs in the retinal epithelium ARPE-19 cells, RAGE-dependently. The mitochondrial dysfunction was induced, and the Bcl-2 family was deregulated during the AGE-BSA-induced ARPE-19 cell apoptosis.

  8. Pigmented choroidal nevus in a child with oculocutaneous albinism.

    PubMed

    Sharma, Priya; Kaliki, Swathi; Peña, Maria Soledad; Shields, Carol L

    2013-04-01

    We report the case of an 8-year-old white girl with albinism and a flat pigmented choroidal lesion in the left eye measuring 0.5 mm in diameter. There was no subretinal fluid, lipofuscin, or drusen. The patient later displayed 10 lightly-pigmented cutaneous nevi on her upper chest, left arm, and right leg at 8 months' follow-up. The choroidal nevus showed minimal change over 2 years.

  9. Relationship between macular pigment and visual function in subjects with early age-related macular degeneration

    PubMed Central

    Nolan, John M; Peto, Tunde; Stack, Jim; Leung, Irene; Corcoran, Laura; Beatty, Stephen

    2017-01-01

    Purpose To investigate the relationship between macular pigment (MP) and visual function in subjects with early age-related macular degeneration (AMD). Methods 121 subjects with early AMD enrolled as part of the Central Retinal Enrichment Supplementation Trial (CREST; ISRCTN13894787) were assessed using a range of psychophysical measures of visual function, including best corrected visual acuity (BCVA), letter contrast sensitivity (CS), mesopic and photopic CS, mesopic and photopic glare disability (GD), photostress recovery time (PRT), reading performance and subjective visual function, using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). MP was measured using customised heterochromatic flicker photometry. Results Letter CS, mesopic and photopic CS, photopic GD and mean reading speed were each significantly (p<0.05) associated with MP across a range of retinal eccentricities, and these statistically significant relationships persisted after controlling for age, sex and cataract grade. BCVA, NEI VFQ-25 score, PRT and mesopic GD were unrelated to MP after controlling for age, sex and cataract grade (p>0.05, for all). Conclusions MP relates positively to many measures of visual function in unsupplemented subjects with early AMD. The CREST trial will investigate whether enrichment of MP influences visual function among those afflicted with this condition. Trial registration number ISRCTN13894787. PMID:27091854

  10. Ultrastructural changes in the melanocytes of aging human choroid.

    PubMed

    Nag, Tapas Chandra

    2015-12-01

    Retinal pigment epithelial cells as well as choroidal melanocytes (CM) possess melanin granules. The former show clear, age-related changes (formation of lipofuscin granules with a concomitant decrease in melanin content); however, data on changes in the CM with aging are fairly limited. We examined CM in human macular and mid-peripheral areas by light- and transmission electron microscopy in 50-94 year-old donor eyes (N=12). Unlike in the choroid of lower ages, the melanocytes from aging choroid (>75 years) showed partial fusion of about 8-15 melanosomes, forming rosettes-like structures. Besides, there was evidence of emptiness in cytoplasm caused by the loss of melanosomes in aged CM, as was confirmed by quantification in macular part of choroid. In advanced aged eyes (85-94-year-old), the CM possessed many lipid droplets as well as irregular lipofuscin granules, the latter had a tendency to fuse with melanosomes, as happens in aged retinal pigment epithelium. Macrophages in their cytoplasm contained abundant irregular as well as clumped melanosomes of variable size, suggesting that damaged granules/melanocytes are cleared by these phagocytes. These obvious changes in the CM are likely to make the choroid prone to damage by visible light.

  11. The effect of thermal aging and color pigments on the Egyptian linen properties evaluated by physicochemical methods

    NASA Astrophysics Data System (ADS)

    El-Gaoudy, H.; Kourkoumelis, N.; Varella, E.; Kovala-Demertzi, D.

    2011-11-01

    Archaeologists in Egypt discovered ancient colored textiles in great quantities in comparison with the analogous uncolored ones. Furthermore, the latter are far more deteriorated. Most research investigations into archaeological linen have been concerned with manufacture, restoration, and conservation but little information is available about the properties of the fibers, and particularly their chemical and physical properties after dyeing with natural dyes or painted with pigments. The aim of this study is to evaluate the physicochemical properties of Egyptian linen textiles coloring with a variety of pigments used in painting in ancient times after thermally aged to get linen samples which are similar as possible to the ancient linen textiles. The evaluations were based on Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction and tensile strength, and elongation measurements. Results showed that beyond cosmetic reasons, colored textiles did indeed play a role as protecting agents affecting strength and reducing thermal deterioration. Specifically, in the molecular level, pigments under study seem to interact to cellulose and lignin compounds of the aged linen while in the macroscopic level tensile and elongation parameters are altered. Electron microscopy confirms that pigment particles are deposited on and between the fibers' surfaces.

  12. Hyperhomocysteinemia disrupts retinal pigment epithelial structure and function with features of age-related macular degeneration

    PubMed Central

    Ibrahim, Ahmed S.; Mander, Suchreet; Hussein, Khaled A.; Elsherbiny, Nehal M.; Smith, Sylvia B.; Al-Shabrawey, Mohamed; Tawfik, Amany

    2016-01-01

    The disruption of retinal pigment epithelial (RPE) function and the degeneration of photoreceptors are cardinal features of age related macular degeneration (AMD); however there are still gaps in our understanding of underlying biological processes. Excess homocysteine (Hcy) has been reported to be elevated in plasma of patients with AMD. This study aimed to evaluate the direct effect of hyperhomocysteinemia (HHcy) on structure and function of RPE. Initial studies in a mouse model of HHcy, in which cystathionine-β-synthase (cbs) was deficient, revealed abnormal RPE cell morphology with features similar to that of AMD upon optical coherence tomography (OCT), fluorescein angiography (FA), histological, and electron microscopic examinations. These features include atrophy, vacuolization, hypopigmentation, thickened basal laminar membrane, hyporeflective lucency, choroidal neovascularization (CNV), and disturbed RPE–photoreceptor relationship. Furthermore, intravitreal injection of Hcy per se in normal wild type (WT) mice resulted in diffuse hyper-fluorescence, albumin leakage, and CNV in the area of RPE. In vitro experiments on ARPE-19 showed that Hcy dose-dependently reduced tight junction protein expression, increased FITC dextran leakage, decreased transcellular electrical resistance, and impaired phagocytic activity. Collectively, our results demonstrated unreported effects of excess Hcy levels on RPE structure and function that lead to the development of AMD-like features. PMID:26885895

  13. In vivo resonant Raman measurement of macular carotenoid pigments in the young and the aging human retina

    NASA Astrophysics Data System (ADS)

    Gellermann, Werner; Ermakov, Igor V.; Ermakova, Maia R.; McClane, Robert W.; Zhao, Da-You; Bernstein, Paul S.

    2002-06-01

    We have used resonant Raman scattering spectroscopy as a novel, noninvasive, in vivo optical technique to measure the concentration of the macular carotenoid pigments lutein and zeaxanthin in the living human retina of young and elderly adults. Using a backscattering geometry and resonant molecular excitation in the visible wavelength range, we measure the Raman signals originating from the single- and double-bond stretch vibrations of the π-conjugated molecule's carbon backbone. The Raman signals scale linearly with carotenoid content, and the required laser excitation is well below safety limits for macular exposure. Furthermore, the signals decline significantly with increasing age in normal eyes. The Raman technique is objective and quantitative and may lead to a new method for rapid screening of carotenoid pigment levels in large populations at risk for vision loss from age-related macular degeneration, the leading cause of blindness in the elderly in the United States.

  14. Cell-Deposited Matrix Improves Retinal Pigment Epithelium Survival on Aged Submacular Human Bruch's Membrane

    PubMed Central

    Sugino, Ilene K.; Gullapalli, Vamsi K.; Sun, Qian; Wang, Jianqiu; Nunes, Celia F.; Cheewatrakoolpong, Noounanong; Johnson, Adam C.; Degner, Benjamin C.; Hua, Jianyuan; Liu, Tong; Chen, Wei; Li, Hong

    2011-01-01

    Purpose. To determine whether resurfacing submacular human Bruch's membrane with a cell-deposited extracellular matrix (ECM) improves retinal pigment epithelial (RPE) survival. Methods. Bovine corneal endothelial (BCE) cells were seeded onto the inner collagenous layer of submacular Bruch's membrane explants of human donor eyes to allow ECM deposition. Control explants from fellow eyes were cultured in medium only. The deposited ECM was exposed by removing BCE. Fetal RPE cells were then cultured on these explants for 1, 14, or 21 days. The explants were analyzed quantitatively by light microscopy and scanning electron microscopy. Surviving RPE cells from explants cultured for 21 days were harvested to compare bestrophin and RPE65 mRNA expression. Mass spectroscopy was performed on BCE-ECM to examine the protein composition. Results. The BCE-treated explants showed significantly higher RPE nuclear density than did the control explants at all time points. RPE expressed more differentiated features on BCE-treated explants than on untreated explants, but expressed very little mRNA for bestrophin or RPE65. The untreated young (<50 years) and African American submacular Bruch's membrane explants supported significantly higher RPE nuclear densities (NDs) than did the Caucasian explants. These differences were reduced or nonexistent in the BCE-ECM-treated explants. Proteins identified in the BCE-ECM included ECM proteins, ECM-associated proteins, cell membrane proteins, and intracellular proteins. Conclusions. Increased RPE survival can be achieved on aged submacular human Bruch's membrane by resurfacing the latter with a cell-deposited ECM. Caucasian eyes seem to benefit the most, as cell survival is the worst on submacular Bruch's membrane in these eyes. PMID:21398292

  15. Pigment characterization of important golden age panel paintings of the 17th century

    NASA Astrophysics Data System (ADS)

    Pięta, Ewa; Proniewicz, Edyta; Szmelter-Fausek, Bożena; Olszewska-Świetlik, Justyna; Proniewicz, Leonard M.

    2015-02-01

    Samples were obtained from two world-famous 17th century panel paintings of the Gdańsk school of panting: 'Seven Acts of Charity' (1607, in St. Mary's Church in Gdańsk, Poland) by Anton Möller and 'Angelic Concert' (1611, in Diocesan Museum in Pelplin, Poland) by Hermann Han. Micro-Raman spectroscopy (MRS), optical microscopy (OM), and X-ray fluorescence (XRF) spectroscopy studies of the samples were performed to characterize the pigments present in the individual painting layers (a rich palette of white, black, blue, red, and yellow pigments) and the pictorial techniques used by the artists.

  16. The lack of age-pigments and the alterations in intracellular monovalent electrolytes in spontaneously hypertensive, stroke-prone (SHRsp) rats as revealed by electron microscopy and X-ray microanalysis

    SciTech Connect

    Zs.-Nagy, I.; Zs.-Nagy, V.; Casoli, T.; Lustyik, G. )

    1989-01-01

    Male, spontaneously hypertensive, stroke-prone (SHRsp) rats established by Okamoto et al. were studied. About 80% of the males of this strain have a particularly short life span (33-41 weeks); they display a considerable hypertension (above 220 mmHg) and a tendency for plurifocal brain strokes. Hypertension and strokes can be provoked in an accelerated and synchronized fashion by supplementing 1% NaCl into their drinking water. Symptoms of the appearance of brain strokes can be judged from characteristic signs of motor disorders, and can be established also by pathohistology. Since hypertension and arteriosclerosis are frequently involved in aging, the question we intended to answer was whether these animals may represent a model of the normal aging process or not. Two approaches are described: (1) Accumulation of lipofuscin granules in their brain, liver and myocardium was followed by transmission electron microscopy before and after the appearance of strokes. It has been established that these tissues do not show any typical accumulation of lipofuscin granules, although submicroscopic signs of an enhanced damage of cell organelles (especially of mitochondria in liver and brain cells, but not in myocardium) were encountered. (2) The intracellular monovalent composition in the brain and liver was measured by using bulk-specimen X-ray microanalysis. The intracellular Na-content (mEq/kg water) was significantly higher (170-200%) in both the brain and liver cells, whereas the K-content increased only moderately (118-130%). The results suggest that although the SHRsp rats do not represent a direct model for the normal aging process from the point of view of lipofuscin accumulation, the shifts of the monovalent electrolyte contents in the brain and liver cells observed already in the youngest ages, are similar to those observed in aged normal rats.

  17. Quantitative Fundus Autofluorescence in Mice: Correlation With HPLC Quantitation of RPE Lipofuscin and Measurement of Retina Outer Nuclear Layer Thickness

    PubMed Central

    Sparrow, Janet R.; Blonska, Anna; Flynn, Erin; Duncker, Tobias; Greenberg, Jonathan P.; Secondi, Roberta; Ueda, Keiko; Delori, François C.

    2013-01-01

    Purpose. Our study was conducted to establish procedures and protocols for quantitative autofluorescence (qAF) measurements in mice, and to report changes in qAF, A2E bisretinoid concentration, and outer nuclear layer (ONL) thickness in mice of different genotypes and age. Methods. Fundus autofluorescence (AF) images (55° lens, 488 nm excitation) were acquired in albino Abca4−/−, Abca4+/−, and Abca4+/+ mice (ages 2–12 months) with a confocal scanning laser ophthalmoscope (cSLO). Gray levels (GLs) in each image were calibrated to an internal fluorescence reference. The bisretinoid A2E was measured by quantitative high performance liquid chromatography (HPLC). Histometric analysis of ONL thicknesses was performed. Results. The Bland-Altman coefficient of repeatability (95% confidence interval) was ±18% for between-session qAF measurements. Mean qAF values increased with age (2–12 months) in all groups of mice. qAF was approximately 2-fold higher in Abca4−/− mice than in Abca4+/+ mice and approximately 20% higher in heterozygous mice. HPLC measurements of the lipofuscin fluorophore A2E also revealed age-associated increases, and the fold difference between Abca4−/− and wild-type mice was more pronounced (approximately 3–4-fold) than measurable by qAF. Moreover, A2E levels declined after 8 months of age, a change not observed with qAF. The decline in A2E levels in the Abca4−/− mice corresponded to reduced photoreceptor cell viability as reflected in ONL thinning beginning at 8 months of age. Conclusions. The qAF method enables measurement of in vivo lipofuscin and the detection of genotype and age-associated differences. The use of this approach has the potential to aid in understanding retinal disease processes and will facilitate preclinical studies. PMID:23548623

  18. 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

  19. EGCG Inhibited Lipofuscin Formation Based on Intercepting Amyloidogenic β-Sheet-Rich Structure Conversion

    PubMed Central

    Cai, Shuxian; Yang, Heng; Zeng, Kewu; Zhang, Jing; Zhong, Ni; Wang, Yingzi; Ye, Jing; Tu, Pengfei; Liu, Zhonghua

    2016-01-01

    Background Lipofuscin (LF) is formed during lipid peroxidation and sugar glycosylation by carbonyl-amino crosslinks with biomacrolecules, and accumulates slowly within postmitotic cells. The environmental pollution, modern dietary culture and lifestyle changes have been found to be the major sources of reactive carbonyl compounds in vivo. Irreversible carbonyl-amino crosslinks induced by carbonyl stress are essentially toxiferous for aging-related functional losses in modern society. Results show that (-)-epigallocatechin gallate (EGCG), the main polyphenol in green tea, can neutralize the carbonyl-amino cross-linking reaction and inhibit LF formation, but the underlying mechanism is unknown. Methods and Results We explored the mechanism of the neutralization process from protein, cell, and animal levels using spectrofluorometry, infrared spectroscopy, conformation antibodies, and electron microscopy. LF demonstrated an amyloidogenic β-sheet-rich with antiparallel structure, which accelerated the carbonyl-amino crosslinks formation and disrupted proteolysis in both PC12 cells and D-galactose (D-gal)-induced brain aging mice models. Additionally, EGCG effectively inhibited the formation of the amyloidogenic β-sheet-rich structure of LF, and prevented its conversion into toxic and on-pathway aggregation intermediates, thereby cutting off the carbonyl-amino crosslinks. Conclusions Our study indicated that the amyloidogenic β-sheet structure of LF may be the core driving force for carbonyl-amino crosslinks further formation, which mediates the formation of amyloid fibrils from native state of biomacrolecules. That EGCG exhibits anti-amyloidogenic β-sheet-rich structure properties to prevent the LF formation represents a novel strategy to impede the development of degenerative processes caused by ageing or stress-induced premature senescence in modern environments. PMID:27030967

  20. Study on the autofluorescence profiles of iris pigment epithelium and retinal pigment epithetlium

    NASA Astrophysics Data System (ADS)

    Xu, Gaixia; Qu, Junle; Chen, Danni; Sun, Yiwen; Zhao, Lingling; Lin, Ziyang; Ding, Zhihua; Niu, Hanben

    2007-05-01

    Transplantation technique of retinal pigment epithelium has been noticeable in recent years and gradually put into clinical practice in treatment of retinal degenerative diseases. Generally, immunological, histochemical, and physical methods are used to study the iris pigment epithelium (IPE) and retinal pigment epithelium (RPE) cells, which need complex sample preparation. In this paper, we provided a simple autofluorescence microscopy to investigate the fresh porcine IPE and RPE cells without any pretreatment. The results showed that the morphology and size of both were similar, round and about 15 μm. The main flourophore in both cells was similar, i.e. lipofuscin. In additional, the autofluorescence spectrum of RPE shifted blue after light-induced damage by laser illuminating. Because it was easier for IPE to be damaged by laser than for RPE, and the power of one scanning operation to get a full image was strong enough to damage IPE sample, we hadn't get any satisfied autofluorescence spectrum of IPE.

  1. SkQ1 slows development of age-dependent destructive processes in retina and vascular layer of eyes of wistar and OXYS rats.

    PubMed

    Saprunova, V B; Lelekova, M A; Kolosova, N G; Bakeeva, L E

    2012-06-01

    We show the development of clearly pronounced age-related pathological changes in eye tissues of Wistar and OXYS rats. Photoreceptor cells were virtually absent in all OXYS rats in the age of 24 months. Massive accumulations of lipofuscin granules were detected in the pigmented epithelium cells. Flattening, overgrowing, and degradation of endothelial cells of choriocapillaries were also observed. Along with these changes, vessels without signs of degradation were detected in the pigmented epithelium. In 24-month-old Wistar rats these changes were local and were seen in only some of the animals. The mitochondria-targeted antioxidant SkQ1 (the rats were given SkQ1 daily with food at the dose of 250 nmol/kg for 5 months, starting from the age of 19 months) prevented the development of these pathological changes in both Wistar and OXYS rats. The data were subjected to mathematical processing and statistical analysis.

  2. Bis-Retinoid A2E Induces an Increase of Basic Fibroblast Growth Factor via Inhibition of Extracellular Signal-Regulated Kinases 1/2 Pathway in Retinal Pigment Epithelium Cells and Facilitates Phagocytosis

    PubMed Central

    Balmer, Delphine; Bapst-Wicht, Linda; Pyakurel, Aswin; Emery, Martine; Nanchen, Natacha; Bochet, Christian G.; Roduit, Raphael

    2017-01-01

    Age-related macular degeneration (ARMD) is the leading cause of vision loss in developed countries. Hallmarks of the disease are well known; indeed, this pathology is characterized by lipofuscin accumulation, is principally composed of lipid-containing residues of lysosomal digestion. The N-retinyl-N-retinylidene ethanolamine (A2E) retinoid which is thought to be a cytotoxic component for RPE is the best-characterized component of lipofuscin so far. Even if no direct correlation between A2E spatial distribution and lipofuscin fluorescence has been established in aged human RPE, modified forms or metabolites of A2E could be involved in ARMD pathology. Mitogen-activated protein kinase (MAPK) pathways have been involved in many pathologies, but not in ARMD. Therefore, we wanted to analyze the effects of A2E on MAPKs in polarized ARPE19 and isolated mouse RPE cells. We showed that long-term exposure of polarized ARPE19 cells to low A2E dose induces a strong decrease of the extracellular signal-regulated kinases' (ERK1/2) activity. In addition, we showed that A2E, via ERK1/2 decrease, induces a significant decrease of the retinal pigment epithelium-specific protein 65 kDa (RPE65) expression in ARPE19 cells and isolated mouse RPE. In the meantime, we showed that the decrease of ERK1/2 activity mediates an increase of basic fibroblast growth factor (bFGF) mRNA expression and secretion that induces an increase in phagocytosis via a paracrine effect. We suggest that the accumulation of deposits coming from outer segments (OS) could be explained by both an increase of bFGF-induced phagocytosis and by the decrease of clearance by A2E. The bFGF angiogenic protein may therefore be an attractive target to treat ARMD. PMID:28298893

  3. Genetic Determinants of Macular Pigments in Women of the Carotenoids in Age-Related Eye Disease Study

    PubMed Central

    Meyers, Kristin J.; Johnson, Elizabeth J.; Bernstein, Paul S.; Iyengar, Sudha K.; Engelman, Corinne D.; Karki, Chitra K.; Liu, Zhe; Igo, Robert P.; Truitt, Barbara; Klein, Michael L.; Snodderly, D. Max; Blodi, Barbara A.; Gehrs, Karen M.; Sarto, Gloria E.; Wallace, Robert B.; Robinson, Jennifer; LeBlanc, Erin S.; Hageman, Gregory; Tinker, Lesley; Mares, Julie A.

    2013-01-01

    Purpose. To investigate genetic determinants of macular pigment optical density in women from the Carotenoids in Age-Related Eye Disease Study (CAREDS), an ancillary study of the Women's Health Initiative Observational Study. Methods. 1585 of 2005 CAREDS participants had macular pigment optical density (MPOD) measured noninvasively using customized heterochromatic flicker photometry and blood samples genotyped for 440 single nucleotide polymorphisms (SNPs) in 26 candidate genes related to absorption, transport, binding, and cleavage of carotenoids directly, or via lipid transport. SNPs were individually tested for associations with MPOD using least-squares linear regression. Results. Twenty-one SNPs from 11 genes were associated with MPOD (P ≤ 0.05) after adjusting for dietary intake of lutein and zeaxanthin. This includes variants in or near genes related to zeaxanthin binding in the macula (GSTP1), carotenoid cleavage (BCMO1), cholesterol transport or uptake (SCARB1, ABCA1, ABCG5, and LIPC), long-chain omega-3 fatty acid status (ELOVL2, FADS1, and FADS2), and various maculopathies (ALDH3A2 and RPE65). The strongest association was for rs11645428 near BCMO1 (βA = 0.029, P = 2.2 × 10−4). Conditional modeling within genes and further adjustment for other predictors of MPOD, including waist circumference, diabetes, and dietary intake of fiber, resulted in 13 SNPs from 10 genes maintaining independent association with MPOD. Variation in these single gene polymorphisms accounted for 5% of the variability in MPOD (P = 3.5 × 10−11). Conclusions. Our results support that MPOD is a multi-factorial phenotype associated with variation in genes related to carotenoid transport, uptake, and metabolism, independent of known dietary and health influences on MPOD. PMID:23404124

  4. New approaches and potential treatments for dry age-related macular degeneration.

    PubMed

    Damico, Francisco Max; Gasparin, Fabio; Scolari, Mariana Ramos; Pedral, Lycia Sampaio; Takahashi, Beatriz Sayuri

    2012-01-01

    Emerging treatments for dry age-related macular degeneration (AMD) and geographic atrophy focus on two strategies that target components involved in physiopathological pathways: prevention of photoreceptors and retinal pigment epithelium loss (neuroprotection induction, oxidative damage prevention, and visual cycle modification) and suppression of inflammation. Neuroprotective drugs, such as ciliary neurotrophic factor, brimonidine tartrate, tandospirone, and anti-amyloid β antibodies, aim to prevent apoptosis of retinal cells. Oxidative stress and depletion of essential micronutrients are targeted by the Age-Related Eye Disease Study (AREDS) formulation. Visual cycle modulators reduce the activity of the photoreceptors and retinal accumulation of toxic fluorophores and lipofuscin. Eyes with dry age-related macular degeneration present chronic inflammation and potential treatments include corticosteroid and complement inhibition. We review the current concepts and rationale of dry age-related macular degeneration treatment that will most likely include a combination of drugs targeting different pathways involved in the development and progression of age-related macular degeneration.

  5. Innovative Troxler-free measurement of macular pigment and lens density with correction of the former for the aging lens.

    PubMed

    Bone, Richard A; Mukherjee, Anirbaan

    2013-10-01

    Simplified measurement of macular pigment optical density (MPOD) is important because of the ocular health benefits that are attributed to these retinal carotenoids. Here, we describe a novel instrument designed for this purpose, based on heterochromatic flicker photometry (HFP), which removes a number of difficulties that subjects often experience with traditional HFP. The instrument generates 1.5- and 15-deg diameter, centrally viewed stimuli that alternate between blue and green colors generated by light emitting diodes (LED). The 15 deg stimulus replaces the small, eccentrically viewed stimulus used in traditional HFP. Subjects adjust the blue LED intensity until flicker is eliminated in the case of the 1.5 deg stimulus and eliminated around the periphery in the case of the 15 deg stimulus. A microprocessor computes the subject's MPOD, in addition to the lens OD, and uses the latter to correct the MPOD. Good repeatability was confirmed through test-retest measurements on 52 subjects. The overwhelming majority of them stated that they found the test easy. The importance of the lens correction on MPOD measurements was confirmed in a simulation study. The study showed that, without the correction, MPOD would show an apparent age-related decline in a population for whom there was no real age dependence.

  6. Retinal pigment epithelium cell-derived exosomes: Possible relevance to CNV in wet-age related macular degeneration.

    PubMed

    Tong, Yao; Zhou, Ya-Li; Wang, Yi-Xiao; Zhao, Pei-Quan; Wang, Zhao-Yang

    2016-12-01

    Exosomes are small vesicles that are released by almost every cell type and play a crucial role in many physiological and pathological processes associated with different diseases. Specifically, they promote angiogenesis in the pathogenesis of some diseases. According to previous research, the proteins of exosomes taken from the aqueous humor (AH) of patients with wet-age related macular degeneration (AMD) may function as a new diagnostic biomarker of AMD, suggesting that exosomes may play an important role in the occurrence and development of choroidal neovascularization (CNV). Moreover, additional research has revealed that the levels of some protein makers of exosomes are up-regulated in aged retinal pigment epithelium (RPE) and that drusen and oxidative stress may promote the secretion of exosomes derived from RPE cells. Consequently, we hypothesize that RPE cell-derived exosomes may be relevant to CNV in wet AMD. If this hypothesis is proven correct, future studies based on this link may also help to elucidate the molecular mechanisms of wet AMD and to find new therapeutic targets for the treatment of AMD.

  7. Effect of age and of screening pigment mutations on the phototactic behavior of Drosophila melanogaster.

    PubMed

    Markow, T A; Scavarda, N J

    1977-03-01

    Five different eye color mutations of Drosophila melanogaster have been tested for their effect on phototactic behavior. All five mutations seem to cause flies to be less photonegative than Canton-S control flies. The mutation sepia was found to produce this effect when heterozygous as well. It was also found that wild-type flies from highly photopositive and photonegative strains seem to be more photoneutral with age.

  8. Effectiveness of Intravitreal Injection of Ranibizumab for Neovascular Age-Related Macular Degeneration with Serous Pigment Epithelial Detachment

    PubMed Central

    Zhao, Chun; Zhang, Zhen; Chen, Lei; Wang, Fang; Xu, Ding

    2016-01-01

    Background We sought to observe the effectiveness of intravitreal injection of ranibizumab in treating neovascular age-related macular degeneration (nAMD) with serous pigment epithelial detachment (sPED). Material/Methods A retrospective, noncomparative case series was performed. Twenty-3 eyes of 23 patients with sPED secondary to nAMD who had received intravitreal injections of ranibizumab were included in this study. All patients underwent best-corrected visual acuity (BCVA), synchronous fluorescein fundus angiography (FFA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT) examinations. All patients were treated with pro re nata intravitreal injections after 3 loading doses of ranibizumab and were followed up for 12 months. The differences in the BCVAs, maximum PED heights, PED volumes and CFTs of the affected eyes were compared between the baseline and last visit. Results Twelve months after the first injection, improved visual acuity was observed in 16 of the 23 eyes. 4 eyes exhibited stable visual acuity, and 3 eyes exhibited impaired visual acuity. The mean post-injection logMAR BCVA was 0.58±0.05, which was much better than that at baseline (0.76±0.08; t=1.751, P=0.0869). The mean maximum PED height at baseline was 350.17±35.73μm and it was decreased to 238.87±36.87μm (t=2.192, P=0.0337) at the last visit. The mean PED volume after injection was 0.34±0.1 mm3, which was significantly decreased compared with that at baseline (0.81±0.21 mm3; t=2.021, P=0.0494).The mean CFT decreased, but this difference was not statistically significant (t=1.003, P=0.3211). None of the patients exhibited endophthalmitis, uveitis or RPE tears. Conclusions Intravitreal injection of ranibizumab for the treatment of neovascular age-related macular degeneration with serous pigment epithelial detachment safely and effectively improved the patients’ visual acuities and decreased their PED heights volumes. PMID:26972376

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

    PubMed Central

    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

    2015-01-01

    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

  10. Aging Related Changes of Retina and Optic Nerve of Uromastyx aegyptia and Falco tinnunculus

    PubMed Central

    2013-01-01

    Aging is a biological phenomenon that involves gradual degradation of the structure and function of the retina and optic nerve. To our knowledge, little is known about the aging-related ocular cell loss in avian (Falco tinnunculus) and reptilian species (Uromastyx aegyptia). A selected 90 animals of pup, middle, and old age U. aegyptia (reptilian) and F. tinnunculus (avian) were used. The retinae and optic nerves were investigated by light and transmission electron microscopy (TEM) and assessments of neurotransmitters, antioxidant enzymes (catalase, superoxide dismustase and glutathione s transferase), caspase-3 and -7, malonadialdhyde, and DNA fragmentation. Light and TEM observations of the senile specimens revealed apparent deterioration of retinal cell layers, especially the pigmented epithelium and photoreceptor outer segments. Their inclusions of melanin were replaced by lipofuscins. Also, vacuolar degeneration and demyelination of the optic nerve axons were detected. Concomitantly, there was a marked increase of oxidative stress involved reduction of neurotransmitters and antioxidant enzymes and an increase of lipid peroxidation, caspase-3 and -7, subG0/G1 apoptosis, and P53. We conclude that aging showed an inverse relationship with the neurotransmitters and antioxidant enzymes and a linear relationship of caspases, malondialdhyde, DNA apoptosis, and P53 markers of cell death. These markers reflected the retinal cytological alterations and lipofuscin accumulation within inner segments. PMID:24215233

  11. Plasma polymer coatings to aid retinal pigment epithelial growth for transplantation in the treatment of age related macular degeneration.

    PubMed

    Kearns, Victoria; Mistry, Anita; Mason, Sharon; Krishna, Yamini; Sheridan, Carl; Short, Robert; Williams, Rachel L

    2012-08-01

    Subretinal transplantation of functioning retinal pigment epithelial (RPE) cells grown on a synthetic substrate is a potential treatment for age-related macular degeneration (AMD), a common cause of irreversible vision loss in developed countries. Plasma polymers give the opportunity to tailor the surface chemistry of the artificial substrate whilst maintaining the bulk properties. In this study, plasma polymers with different functionalities were investigated in terms of their effect on RPE attachment and growth. Plasma polymers of acrylic acid (AC), allyl amine (AM) and allyl alcohol (AL) were fabricated and characterised using X-ray photoelectron spectroscopy (XPS) and water contact angle measurements. Octadiene (OD) hydrocarbon films and tissue culture polystyrene were used as controls. Wettability varied from hydrophobic OD to relatively hydrophilic AC. XPS demonstrated four very different surfaces with the expected functionalities. Attachment, proliferation and morphological examination of an RPE cell line and primary RPE cells were investigated. Both cell types grew on all surfaces, with the exception of OD, although the proliferation rate of primary cells was low. Good epithelial morphology was also demonstrated. Plasma polymerised films show potential as cell carrier surfaces for RPE cells in the treatment of AMD.

  12. Subducted and Melanotic Cells in Advanced Age-Related Macular Degeneration Are Derived From Retinal Pigment Epithelium

    PubMed Central

    Zanzottera, Emma C.; Messinger, Jeffrey D.; Ach, Thomas; Smith, R. Theodore; Curcio, Christine A.

    2015-01-01

    Purpose. To describe, illustrate, and account for two cell types plausibly derived from RPE in geographic atrophy (GA) and choroidal neovascularization (CNV) of AMD, using melanosomes, lipofuscin, and basal laminar deposit (BLamD) as anatomical markers. Methods. Human donor eyes with GA (n = 13) or CNV (n = 39) were histologically processed, photodocumented, and analyzed for frequencies of occurrence. We defined RPE as cells containing spindle-shaped melanosomes and RPE lipofuscin, internal to basal lamina or BLamD, if present, or Bruch's membrane if not, and RPE-derived cells as those plausibly derived from RPE and not attached to basal lamina or BLamD. Results. ‘Subducted’ cells contain RPE melanosomes and localize to the sub-RPE space, on Bruch's membrane. Credible transitional forms from RPE cells were seen. Grades of RPE overlying ‘Subducted’ cells were ‘Atrophic with BLamD’ (32.2% vs. 37.0% of ‘Subducted,’ for GA and CNV eyes, respectively), ‘Dissociated’ (22.0% vs. 21.7%), ‘Nonuniform’ (22.0% vs. 23.9%), and ‘Sloughed’ RPE (10.2% vs. 4.3%). Found exclusively in CNV scars, ‘Melanotic’ cells containing spherical melanosomes were adjacent to ‘Entombed’ RPE with spindle-shaped and spherical melanosomes. Of subretinal ‘Melanotic’ cells, 40.0% associated with ‘Atrophy with BLamD,’ 36.8% with ‘Atrophy without BLamD,’ and 20.6% with ‘Entombed.’ Conclusions. ‘Dissociated’ RPE within atrophic areas may be the source of ‘Subducted’ cells. ‘Entombed’ RPE within fibrovascular and fibrocellular scars may be the source of ‘Melanotic’ cells. An imaging correlate for ‘Subducted’ cells awaits discovery; ‘Melanotic’ cells appear gray-black in the CNV fundus. Results provide a basis for future molecular phenotyping studies. PMID:26024109

  13. Comparison of Mouse and Human Retinal Pigment Epithelium Gene Expression Profiles: Potential Implications for Age-Related Macular Degeneration

    PubMed Central

    Bennis, Anna; Gorgels, Theo G. M. F.; ten Brink, Jacoline B.; van der Spek, Peter J.; Bossers, Koen; Heine, Vivi M.; Bergen, Arthur A.

    2015-01-01

    Background The human retinal pigment epithelium (RPE) plays an important role in the pathogenesis of age related macular degeneration (AMD). AMD is the leading cause of blindness worldwide. There is currently no effective treatment available. Preclinical studies in AMD mouse models are essential to develop new therapeutics. This requires further in-depth knowledge of the similarities and differences between mouse and human RPE. Methods We performed a microarray study to identify and functionally annotate RPE specific gene expression in mouse and human RPE. We used a meticulous method to determine C57BL/6J mouse RPE signature genes, correcting for possible RNA contamination from its adjacent layers: the choroid and the photoreceptors. We compared the signature genes, gene expression profiles and functional annotations of the mouse and human RPE. Results We defined sets of mouse (64), human (171) and mouse–human interspecies (22) RPE signature genes. Not unexpectedly, our gene expression analysis and comparative functional annotation suggested that, in general, the mouse and human RPE are very similar. For example, we found similarities for general features, like “organ development” and “disorders related to neurological tissue”. However, detailed analysis of the molecular pathways and networks associated with RPE functions, suggested also multiple species-specific differences, some of which may be relevant for the development of AMD. For example, CFHR1, most likely the main complement regulator in AMD pathogenesis was highly expressed in human RPE, but almost absent in mouse RPE. Furthermore, functions assigned to mouse and human RPE expression profiles indicate (patho-) biological differences related to AMD, such as oxidative stress, Bruch’s membrane, immune-regulation and outer blood retina barrier. Conclusion These differences may be important for the development of new therapeutic strategies and translational studies in age-related macular

  14. Ozone ameliorates age-related oxidative stress changes in rat liver and kidney: effects of pre- and post-ageing administration.

    PubMed

    Safwat, M H; El-Sawalhi, M M; Mausouf, M N; Shaheen, A A

    2014-05-01

    The ageing process is known to be accompanied by increased oxidative stress and compromised antioxidant defenses. Controlled ozone administration has been shown to be effective in various pathophysiological conditions with an underlying oxidative burden. However, its effect on the biochemical alterations associated with the ageing process has been rarely studied. Therefore, the present work was carried out to study the role of ozone in counteracting the state of oxidative stress associated with ageing in rat liver and kidneys using two experimental models. In the pre-ageing model, ozone was administered prior to the onset of ageing at adulthood and continued after the start of the ageing process (3-month-old rats until the age of 15 months). While in the post-ageing model, ozone was administered after ageing has begun and lasted for one month (14-month-old rats until the age of 15 months). The pre-ageing ozone administration effectively reduced lipid and protein oxidation markers, namely, malondialdehyde and protein carbonyl levels and decreased lipofuscin pigment deposition in rat liver and kidneys. Moreover, it significantly restored hepatic and renal reduced glutathione (GSH) contents and normalized cytosolic hepatic glutathione peroxidase activity. Similar but less pronounced effects were observed in the post-ageing ozone-treated group. Nevertheless, in the latter model ozone administration failed to significantly affect liver and kidney lipofuscin levels, as well as kidney GSH contents. These data provide evidences for potentially positive effects of pre-ageing ozone therapy in neutralizing chronic oxidative stress associated with ageing in rat liver and kidneys.

  15. Application and development of a spectrally-resolved confocal microscope: A study of lipofuscin emission properties

    NASA Astrophysics Data System (ADS)

    Haralampus-Grynaviski, Nicole Marie

    A unique spectrally-resolved confocal microscope is developed for use in biophysical applications. This microscope enables the rapid collection of the complete emission spectra for every pixel in a fluorescence image. The basic optical design and function of the device are assessed through examination of fluorescently labeled beads, using both one- and two-photon excitation. The spatial resolution of the device is found to approach the diffraction limit in the lateral plane and ˜2 mum in the axial plane. This device can readily distinguish between overlapping emissions which are not easily differentiated using standard filter techniques. The potential of this device to be used as a detection method in DNA sequence experiments is demonstrated. Images of a human skin tissue section and a mouse kidney section are presented which demonstrate the structure and spectra of biologic samples can be resolved. The emission properties of human ocular lipofuscin, LF, a heterogeneous auto-fluorescent material associated with age-related macular degeneration is investigated in detail. Isolated LF granules show substantial variation in emission spectra. Near-field scanning microscopy experiments find the emissive regions on a single LF granule are homogeneous on the ˜150 nm scale and confirm results obtained on the microscope developed here. For ˜100 studied LF deposits, the histogram of the measured peak emission is centered around 18,000 cm-1 (555 nm). The average emission spectra for large LF aggregates (peak 17,150 cm-1) is red-shifted compared to the average emission from small individual granules (peak 17,600 cm-1). The average LF granule emission observed here is similar to previously reported bulk LF emission and the emission of a previously identified LF chromophore, A2E. Individual LF granules show a broad range in emission maximum whether the LF is isolated from multiple donors or examined within the cells of a single donor. Multiple as yet unidentified chromophores

  16. Quantitative Autofluorescence and Cell Density Maps of the Human Retinal Pigment Epithelium

    PubMed Central

    Ach, Thomas; Huisingh, Carrie; McGwin, Gerald; Messinger, Jeffrey D.; Zhang, Tianjiao; Bentley, Mark J.; Gutierrez, Danielle B.; Ablonczy, Zsolt; Smith, R. Theodore; Sloan, Kenneth R.; Curcio, Christine A.

    2014-01-01

    Purpose. Lipofuscin (LF) accumulation within RPE cells is considered pathogenic in AMD. To test whether LF contributes to RPE cell loss in aging and to provide a cellular basis for fundus autofluorescence (AF) we created maps of human RPE cell number and histologic AF. Methods. Retinal pigment epithelium–Bruch's membrane flat mounts were prepared from 20 donor eyes (10 ≤ 51 and 10 > 80 years; postmortem: ≤4.2 hours; no retinal pathologies), preserving foveal position. Phalloidin-binding RPE cytoskeleton and LF-AF (488-nm excitation) were imaged at up to 90 predefined positions. Maps were assembled from 83,330 cells in 1470 locations. From Voronoi regions representing each cell, the number of neighbors, cell area, and total AF intensity normalized to an AF standard was determined. Results. Highly variable between individuals, RPE-AF increases significantly with age. A perifoveal ring of high AF mirrors rod photoreceptor topography and fundus-AF. Retinal pigment epithelium cell density peaks at the fovea, independent of age, yet no net RPE cell loss is detectable. The RPE monolayer undergoes considerable lifelong re-modeling. The relationship of cell size and AF, a surrogate for LF concentration, is orderly and linear in both groups. Autofluorescence topography differs distinctly from the topography of age-related rod loss. Conclusions. Digital maps of quantitative AF, cell density, and packing geometry provide metrics for cellular-resolution clinical imaging and model systems. The uncoupling of RPE LF content, cell number, and photoreceptor topography in aging challenges LF's role in AMD. PMID:25034602

  17. Research resource: nuclear receptor atlas of human retinal pigment epithelial cells: potential relevance to age-related macular degeneration.

    PubMed

    Dwyer, Mary A; Kazmin, Dmitri; Hu, Peng; McDonnell, Donald P; Malek, Goldis

    2011-02-01

    Retinal pigment epithelial (RPE) cells play a vital role in retinal physiology by forming the outer blood-retina barrier and supporting photoreceptor function. Retinopathies including age-related macular degeneration (AMD) involve physiological and pathological changes in the epithelium, severely impairing the retina and effecting vision. Nuclear receptors (NRs), including peroxisome proliferator-activated receptor and liver X receptor, have been identified as key regulators of physiological pathways such as lipid metabolic dysregulation and inflammation, pathways that may also be involved in development of AMD. However, the expression levels of NRs in RPE cells have yet to be systematically surveyed. Furthermore, cell culture lines are widely used to study the biology of RPE cells, without knowledge of the differences or similarities in NR expression and activity between these in vitro models and in vivo RPE. Using quantitative real-time PCR, we assessed the expression patterns of all 48 members of the NR family plus aryl hydrocarbon receptor and aryl hydrocarbon receptor nuclear translocator in human RPE cells. We profiled freshly isolated cells from donor eyes (in vivo), a spontaneously arising human cell line (in vitro), and primary cell culture lines (in vitro) to determine the extent to which NR expression in the cultured cell lines reflects that of in vivo. To evaluate the validity of using cell culture models for investigating NR receptor biology, we determined transcriptional activity and target gene expression of several moderately and highly expressed NRs in vitro. Finally, we identified a subset of NRs that may play an important role in pathobiology of AMD.

  18. Alpha Crystallins in the Retinal Pigment Epithelium and Implications for the Pathogenesis and Treatment of Age-Related Macular Degeneration

    PubMed Central

    Kannan, Ram; Sreekumar, Parameswaran G.; Hinton, David R.

    2015-01-01

    Background αA- and αB crystallins are principal members of the small heat shock protein family and elicit both a cell protective function and a chaperone function. α-Crystallins have been found to be prominent proteins in normal and pathological retina emphasizing the importance for in-depth understanding of their function and significance. Scope of Review Retinal pigment epithelial cells (RPE) play a vital role in the pathogenesis of age-related macular degeneration (AMD). This review addresses a number of cellular functions mediated by α-crystallins in the retina. Prominent expression of αB crystallin in mitochondria may serve to protect cells from oxidative injury. αB crystallin as secretory protein via exosomes can offer neuroprotection to adjacent RPE cells and photoreceptors. The availability of chaperone-containing minipeptides of αB crystallin could prove to be a valuable new tool for therapeutic treatment of retinal disorders. Major Conclusions α-Crystallins are expressed in cytosol and mitochondria of RPE cells and are regulated during oxygen-induced retinopathy and during development. α-Crystallins protect RPE from oxidative-and ER stress-induced injury and autophagy. αB-Crystallin is a modulator of angiogenesis and vascular endothelial growth factor. αB Crystallin is secreted via exosomal pathway. Minichaperone peptides derived from αB Crystallin prevent oxidant induced cell death and have therapeutic potential. General Significance Overall, this review summarizes several novel properties of α-crystallins and their relevance to maintaining normal retinal function. In particular, the use of α-crystallin derived peptides is a promising therapeutic strategy to combat retinal diseases such as AMD. PMID:26026469

  19. Distributions of elements in the human retinal pigment epithelium.

    PubMed

    Ulshafer, R J; Allen, C B; Rubin, M L

    1990-01-01

    Distributions of elements above the atomic number of sodium were mapped in the retinal pigment epithelia of eight human eyes. X-ray energy spectra and maps were collected from cryofixed, freeze-dried, and epoxy-embedded tissues using energy-dispersive x-ray microanalysis. All eyes had high concentrations of phosphorus in the nuclei of retinal pigment epithelial cells. Melanosomes were rich in sulfur, zinc, calcium, and iron. Lipofuscin and cytoplasm contained only phosphorus and sulfur in detectable amounts. Drusen, when present, contained phosphorus and calcium. Six eyes had a prominent aluminum peak recorded from melanosomes, nuclei, and Bruch's membrane. In one pair of 90-year-old eyes, small, electron-dense deposits surrounded many melanosomes and contained mercury and selenium. Retinal pigment epithelial melanosomes may bind and accumulate metals and other potentially toxic ions over time, preventing them from reaching the neural retina.

  20. The Role of Breast Size and Areolar Pigmentation in Perceptions of Women's Sexual Attractiveness, Reproductive Health, Sexual Maturity, Maternal Nurturing Abilities, and Age.

    PubMed

    Dixson, Barnaby J; Duncan, Melanie; Dixson, Alan F

    2015-08-01

    Women's breast morphology is thought to have evolved via sexual selection as a signal of maturity, health, and fecundity. While research demonstrates that breast morphology is important in men's judgments of women's attractiveness, it remains to be determined how perceptions might differ when considering a larger suite of mate relevant attributes. Here, we tested how variation in breast size and areolar pigmentation affected perceptions of women's sexual attractiveness, reproductive health, sexual maturity, maternal nurturing abilities, and age. Participants (100 men; 100 women) rated images of female torsos modeled to vary in breast size (very small, small, medium, and large) and areolar pigmentation (light, medium, and dark) for each of the five attributes listed above. Sexual attractiveness ratings increased linearly with breast size, but large breasts were not judged to be significantly more attractive than medium-sized breasts. Small and medium-sized breasts were rated as most attractive if they included light or medium colored areolae, whereas large breasts were more attractive if they had medium or dark areolae. Ratings for perceived age, sexual maturity, and nurturing ability also increased with breast size. Darkening the areolae reduced ratings of the reproductive health of medium and small breasts, whereas it increased ratings for large breasts. There were no significant sex differences in ratings of any of the perceptual measures. These results demonstrate that breast size and areolar pigmentation interact to determine ratings for a suite of sociosexual attributes, each of which may be relevant to mate choice in men and intra-sexual competition in women.

  1. Positive association of circulating levels of advanced glycation end products (AGEs) with pigment epithelium-derived factor (PEDF) in a general population.

    PubMed

    Yamagishi, Sho-Ichi; Matsui, Takanori; Adachi, Hisashi; Takeuchi, Masayoshi

    2010-02-01

    We have recently found that serum levels of pigment epithelium-derived factor (PEDF), a glycoprotein with anti-oxidative and anti-inflammatory properties, are elevated in proportion to the accumulation of the number of the components of the metabolic syndrome. Since formation and accumulation of advanced glycation end products (AGEs) progress under the metabolic syndrome and that PEDF could inhibit the AGE-elicited tissue damage, it is conceivable that PEDF levels may be increased as a counter-system against AGEs in patients with the metabolic syndrome. However, correlation between circulating levels of AGEs and PEDF in humans remains to be elucidated. In this study, we investigated the relationship between serum AGE and PEDF levels in a general population and examined the effects of AGEs on PEDF gene expression in vitro. One hundred ninety-six Japanese subjects in a general population underwent a complete history and physical examination, determination of blood chemistries, including serum levels of AGEs and PEDF. In multiple regression analyses, creatinine, body mass index, triglycerides, AGEs and insulin were independently correlated with serum PEDF levels. AGEs dose-dependently increased PEDF gene expression in cultured adipocytes and liver cells. Our present study demonstrated first that circulating AGEs were one of the independent correlates of serum levels of PEDF. Adipose tissue and liver may be target organs for the AGE-induced PEDF overexpression in humans. Serum PEDF levels may be elevated in response to circulating AGEs as a counter-system against the AGE-elicited tissue damage.

  2. Estrogen signalling in the pathogenesis of age-related macular degeneration.

    PubMed

    Kaarniranta, Kai; Machalińska, Anna; Veréb, Zoltán; Salminen, Antero; Petrovski, Goran; Kauppinen, Anu

    2015-02-01

    Age-related macular degeneration (AMD) is a multifactorial eye disease that is associated with aging, family history, smoking, obesity, cataract surgery, arteriosclerosis, hypertension, hypercholesterolemia and unhealthy diet. Gender has commonly been classified as a weak or inconsistent risk factor for AMD. This disease is characterized by degeneration of retinal pigment epithelial (RPE) cells, Bruch's membrane, and choriocapillaris, which secondarily lead to damage and death of photoreceptor cells and central visual loss. Pathogenesis of AMD involves constant oxidative stress, chronic inflammation, and increased accumulation of lipofuscin and drusen. Estrogen has both anti-oxidative and anti-inflammatory capacity and it regulates signaling pathways that are involved in the pathogenesis of AMD. In this review, we discuss potential cellular signaling targets of estrogen in retinal cells and AMD pathology.

  3. Demonstration of lipofuscin and Nissl bodies in crystal violet stained sections using a fluorescence technique or pyronin Y stain.

    PubMed

    Terr, L I

    1986-09-01

    This paper presents two simple, reliable methods for identification of lipofuscin and Nissl bodies in the same section. One method shows that lipofuscin stained with crystal violet retains its ability to fluoresce and can be observed under the fluorescence microscope after the stain has faded. Fading is accompanied by a gradual increase in the intensity of the fluorescence and is complete in about 5 min. Exciting illumination from this part of the spectrum also substantially fades staining of other autofluorescing tissue elements, such as lipids. Nonfluorescing structures, such as Nissl bodies, remain stained. By changing from transillumination with tungsten light to epifluorescent illumination and vice versa, both types of structures--Nissl bodies and lipofuscin--can be identified in the same section. The second technique uses pyronin Y for staining Nissl bodies in preparations previously stained with crystal violet. Nissl bodies are stained pink but lipofuscin remains violet. Lipofuscin in these sections also remains autofluorescent after the crystal violet stain has faded under violet or near-UV light.

  4. The human oral raphe system. Architectonics and neuronal types in pigment-Nissl preparations.

    PubMed

    Ohm, T G; Heilmann, R; Braak, H

    1989-01-01

    Serial sections (15 microns, 120 microns, and 400 microns) of nine brain stems treated with a combined lipofuscin pigment-Nissl stain were examined in order to delineate the three-dimensional conformation and subdivisions as well as the neuronal types of the human oral raphe system. Characteristic lipofuscin deposits within the somata of various cell types facilitated the demarcation of the oral raphe nuclei from surrounding structures. The dorsal, central, and linear raphe nuclei, e.g. the major subdivisions of the oral raphe system, share common traits as far as neuronal composition and pigmentation is concerned. The interfascicular subnucleus, the dorsofascicular subnucleus, and the intercalate subnucleus are minor subdivisions of the dorsal raphe nucleus. The intercalate one cannot be differentiated from surrounding areas in preparations solely stained for Nissl-material, while it can facilely be identified in combined pigment-Nissl preparations by virtue of differences in the pigmentation pattern. Our architectonical concept of the oral raphe system is in good accordance with the one derived from immunocytochemical investigations of serotonin-containing neurons in the human brain stem. Furthermore, five main neuronal types are described which constitute the oral raphe nuclei. They have been differentiated according to their characteristics as seen in combined pigment-Nissl preparations. I) Large ovoid to polygonal neurons with densely packed and intensely stained pigment granules. II) Similarly featured cells displaying dust-fine and faintly stained pigment granules. III) Medium-sized, ovoid to polygonal neurons with loosely distributed, small pigment granules. IV) Small ovoid neurons devoid of pigment or with only few, intensely stained granules. V) Small spindle-shaped nerve cells with various amounts of intensely stained pigment granules.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Aging-associated changes in human brain.

    PubMed

    Mrak, R E; Griffin, S T; Graham, D I

    1997-12-01

    A wide variety of anatomic and histological alterations are common in brains of aged individuals. However, identification of intrinsic aging changes--as distinct from changes resulting from cumulative environmental insult--is problematic. Some degree of neuronal and volume loss would appear to be inevitable, but recent studies have suggested that the magnitudes of such changes are much less than previously thought, and studies of dendritic complexity in cognitively intact individuals suggest continuing neuronal plasticity into the eighth decade. A number of vascular changes become more frequent with age, many attributable to systemic conditions such as hypertension and atherosclerosis. Age-associated vascular changes not clearly linked to such conditions include hyaline arteriosclerotic changes with formation of arterial tortuosities in small intracranial vessels and the radiographic changes in deep cerebral white matter known as "leukoaraiosis." Aging is accompanied by increases in glial cell activation, in oxidative damage to proteins and lipids, in irreversible protein glycation, and in damage to DNA, and such changes may underlie in part the age-associated increasing incidence of "degenerative" conditions such as Alzheimer disease and Parkinson disease. A small number of histological changes appear to be universal in aged human brains. These include increasing numbers of corpora amylacea within astrocytic processes near blood-brain or cerebrospinal fluid-brain interfaces, accumulation of the "aging" pigment lipofuscin in all brain regions, and appearance of Alzheimer-type neurofibrillary tangles (but not necessarily amyloid plaques) in mesial temporal structures.

  6. Effects of ageing on different binders for retouching and on some binder-pigment combinations used for restoration of wall paintings

    SciTech Connect

    Ropret, P. Zoubek, R.; Skapin, A. Sever Bukovec, P.

    2007-11-15

    In restoration of colour layers, the selection of the most appropriate retouching binder is a very important step that may have a crucial impact on materials durability. As different weather conditions can have versatile influence on stability of colour layers, we determined the effect of ageing on carefully selected samples of binders (Tylose, Klucel, ammonium caseinate, gum arabicum, fish and skin glues and some other synthetic binders) as well as on several binder-pigment combinations (the pigments in combinations being cinnabar, green earth and smalt). The samples were subjected to accelerated ageing tests in climatic chambers. In these tests the temperature and the relative humidity were daily oscillating between - 20 deg. C and 50 deg. C and 50% to 90%, respectively, for a period of one month. Then the samples were exposed to UV and visible light generated by a metal halide lamp for a month. The differences in microstructure before and after ageing were determined by optical and scanning electron microscopy, while the ageing of the organic structures in binders was investigated by Fourier transform infrared (FTIR) microscopy.

  7. 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.

  8. The Value of Measurement of Macular Carotenoid Pigment Optical Densities and Distributions in Age-Related Macular Degeneration and Other Retinal Disorders

    PubMed Central

    Bernstein, Paul S.; Delori, François C.; Richer, Stuart; van Kuijk, Frederik J. M.; Wenzel, Adam J.

    2009-01-01

    There is increasing recognition that the optical and antioxidant properties of the xanthophyll carotenoids lutein and zeaxanthin play an important role in maintaining the health and function of the human macula. In this review article, we assess the value of non-invasive quantification of macular pigment levels and distributions to identify individuals potentially at risk for visual disability or catastrophic vision loss from age-related macular degeneration, and we consider the strengths and weaknesses of the diverse measurement methods currently available. PMID:19854211

  9. Transmission of light to the young primate retina: possible implications for the formation of lipofuscin.

    PubMed

    Gaillard, Elizabeth R; Merriam, John; Zheng, Lei; Dillon, James

    2011-01-01

    The purpose of this study was to determine the transmission properties of the anterior segment of young primate eyes and potentially relate those changes to photochemical processes in the retina that lead to the early, rapid formation of lipofuscin. A simple method has been developed to determine the optical properties of the anterior segment of the intact eye. Using this technique, the transmission/absorption properties of primate cadaver eyes were determined. A young primate anterior segment has a maximum absorption at 365nm due to the presence of the O-β-glucoside of 3-hydroxykynurenine in the lens. This is synthesized in the last trimester of gestation. Although this compound filters out most of the UV light from reaching the retina, there is a small window of transmission centered on an absorption minimum at 320nm. This closes by the second decade of life. The window of transmission of UV light to the primate retina may explain the initial accelerated formation of lipofuscin in the young human retina by a photochemical process. This would be exacerbated by any decrease in the ozone layer with concomitant increase in UV-B reaching the earth's surface.

  10. Light-induced degeneration and microglial response in the retina of an epibenthonic pigmented teleost: age-dependent photoreceptor susceptibility to cell death.

    PubMed

    Bejarano-Escobar, Ruth; Blasco, Manuel; Martín-Partido, Gervasio; Francisco-Morcillo, Javier

    2012-11-01

    Constant intense light causes apoptosis of photoreceptors in the retina of albino fish. However, very few studies have been performed on pigmented species. Tench (Tinca tinca) is a teleost inhabiting dimly lit environments that has a predominance of rods within the photoreceptor layer. To test the hypothesis that constant high intensity light can result in retinal damage in such pigmented epibenthonic teleost species, photodegeneration of the retina was investigated in the larvae and in juveniles of tench to assess whether any damage may also be dependent on fish age. We exposed both groups of animals to 5 days of constant darkness, followed by 4 days of constant 20,000 lx light, and then by 6 days of recovery in a 14 h light:10 h dark cycle. The results showed that the retina of the larvae group exhibited abundant photoreceptor cell apoptosis during the time of exposition to intense light, whereas that of juveniles was indifferent to it. Damaged retinas showed a strong TUNEL signal in photoreceptor nuclei, and occasionally a weak cytoplasmic TUNEL signal in Müller glia. Specific labelling of microglial cells with Griffonia simplicifolia lectin (GSL) histochemistry revealed that photoreceptor cell death alerts microglia in the degenerating retina, leading to local proliferation, migration towards the injured outer nuclear layer (ONL), and enhanced phagocytosis of photoreceptor debris. During the first days of intense light treatment, Müller cells phagocytosed dead photoreceptor cells but, once microglial cells became activated, there was a progressive increase in the phagocytic capacity of the microglia.

  11. Age-Related Susceptibility to Apoptosis in Human Retinal Pigment Epithelial Cells Is Triggered by Disruption of p53–Mdm2 Association

    PubMed Central

    Bhattacharya, Sujoy; Chaum, Edward; Johnson, Dianna A.; Johnson, Leonard R.

    2012-01-01

    Purpose. Relatively little is known about the contribution of p53/Mdm2 pathway in apoptosis of retinal pigment epithelial (RPE) cells or its possible link to dysfunction of aging RPE or to related blinding disorders such as age-related macular degeneration (AMD). Methods. Age-associated changes in p53 activation were evaluated in primary RPE cultures from human donor eyes of various ages. Apoptosis was evaluated by activation of caspases and DNA fragmentation. Gene-specific small interfering RNA was used to knock down expression of p53. Results. We observed that the basal rate of p53-dependent apoptosis increased in an age-dependent manner in human RPE. The age-dependent increase in apoptosis was linked to alterations in several aspects of the p53 pathway. p53 phosphorylation Ser15 was increased through the stimulation of ATM-Ser1981. p53 acetylation Lys379 was increased through the inhibition of SIRT1/2. These two posttranslational modifications of p53 blocked the sequestration of p53 by Mdm2, thus resulting in an increase in free p53 and of p53 stimulation of apoptosis through increased expression of PUMA (p53 upregulated modulator of apoptosis) and activation of caspase-3. Aged RPE also had reduced expression of antiapoptotic Bcl-2, which contributed to the increase in apoptosis. Of particular interest in these studies was that pharmacologic treatments to block p53 phosphorylation, acetylation, or expression were able to protect RPE cells from apoptosis. Conclusions. Our studies suggest that aging in the RPE leads to alterations of specific checkpoints in the apoptotic pathway, which may represent important molecular targets for the treatment of RPE-related aging disorders such as AMD. PMID:23139272

  12. Contributions of age-related alterations of the retinal pigment epithelium and of glia to the AMD-like pathology in OXYS rats

    PubMed Central

    Telegina, Darya V.; Kozhevnikova, Oyuna S.; Bayborodin, Sergey I.; Kolosova, Nataliya G.

    2017-01-01

    Age-related macular degeneration (AMD) is a major cause of blindness in developed countries, and the molecular pathogenesis of early events of AMD is poorly understood. It is known that age-related alterations of retinal pigment epithelium (RPE) cells and of glial reactivity are early hallmarks of AMD. Here we evaluated contributions of the age-related alterations of the RPE and of glia to the development of AMD-like retinopathy in OXYS rats. We showed that destructive alterations in RPE cells are a primary change during the development of retinopathy in OXYS rats. Furthermore, a defect of retinal maturation and decreased immune function at the preclinical stage of retinopathy were observed in OXYS rats in addition to the impairment of RPE cell proliferation and of their capacity for division. At the active stage of the disease, the atrophic alterations increased, and reactive gliosis was observed when disease progressed, but immune function stayed weakened. Unexpectedly, we did not observe migration of microglia and macrophages into the photoreceptor layer. These results and the wide spectrum of age-related retinal alterations in humans as well as individual differences in the risk of AMD may be attributed to genetic factors and to differences in the underlying molecular events. PMID:28134357

  13. Functional aging and gradual senescence in zebrafish.

    PubMed

    Kishi, Shuji

    2004-06-01

    Zebrafish (Danio rerio) has been recognized as a powerful model for genetic studies in developmental biology. Recently, the zebrafish system also has given insights into several human diseases such as neurodegenerative, hematopoietic, and cardiovascular disease, and cancer. Because aging processes affect these and various other human disorders, it is important to compare zebrafish and mammalian senescence. However, the aging process of zebrafish remains largely unexplored, and little is known about functional aging and senescence in zebrafish. In our initial studies to assess aging phenotypes in zebrafish, we have identified several potential aging biomarkers in an ongoing search for suitable ones on zebrafish aging. In aging zebrafish, we detected senescence-associated beta-galactosidase activity in skin and oxidized protein accumulation in muscle. On the other hand, we did not observe lipofuscin granules (aging pigments), which accumulate in postmitotic cells, in muscle of zebrafish with advancing age. Consistently, there were continuously proliferating myocytes that incorporated BrdU in muscle tissues of the aged fish. Moreover, we demonstrated that zebrafish have constitutively abundant telomerase activity in adult somatic tissues implicating unlimited replicative ability of cells throughout their lives. Although some stress-associated markers are upregulated and minor histological changes are observed during the aging process of zebrafish, our studies together with other evidence of remarkable reproductive and regenerative abilities suggest that zebrafish show very gradual senescence. By using those biological and biochemical aging markers already characterized in normal zebrafish, transgenic fish analyses and genetic mutant fish screens can be readily performed. These efforts will help to elucidate the role and molecular mechanisms of common or different pathways of aging among vertebrates from fish to humans and also will contribute to the discovery of

  14. Spatial and Spectral Characterization of Human Retinal Pigment Epithelium Fluorophore Families by Ex Vivo Hyperspectral Autofluorescence Imaging

    PubMed Central

    Ben Ami, Tal; Tong, Yuehong; Bhuiyan, Alauddin; Huisingh, Carrie; Ablonczy, Zsolt; Ach, Thomas; Curcio, Christine A.; Smith, R. Theodore

    2016-01-01

    Purpose Discovery of candidate spectra for abundant fluorophore families in human retinal pigment epithelium (RPE) by ex vivo hyperspectral imaging. Methods Hyperspectral autofluorescence emission images were captured between 420 and 720 nm (10-nm intervals), at two excitation bands (436–460, 480–510 nm), from three locations (fovea, perifovea, near-periphery) in 20 normal RPE/Bruch's membrane (BrM) flatmounts. Mathematical factorization extracted a BrM spectrum (S0) and abundant lipofuscin/melanolipofuscin (LF/ML) spectra of RPE origin (S1, S2, S3) from each tissue. Results Smooth spectra S1 to S3, with perinuclear localization consistent with LF/ML at all three retinal locations and both excitations in 14 eyes (84 datasets), were included in the analysis. The mean peak emissions of S0, S1, and S2 at λex 436 nm were, respectively, 495 ± 14, 535 ± 17, and 576 ± 20 nm. S3 was generally trimodal, with peaks at either 580, 620, or 650 nm (peak mode, 650 nm). At λex 480 nm, S0, S1, and S2 were red-shifted to 526 ± 9, 553 ± 10, and 588 ± 23 nm, and S3 was again trimodal (peak mode, 620 nm). S1 often split into two spectra, S1A and S1B. S3 strongly colocalized with melanin. There were no significant differences across age, sex, or retinal location. Conclusions There appear to be at least three families of abundant RPE fluorophores that are ubiquitous across age, retinal location, and sex in this sample of healthy eyes. Further molecular characterization by imaging mass spectrometry and localization via super-resolution microscopy should elucidate normal and abnormal RPE physiology involving fluorophores. Translational Relevance Our results help establish hyperspectral autofluorescence imaging of the human retinal pigment epithelium as a useful tool for investigating retinal health and disease. PMID:27226929

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

    PubMed

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

    2016-09-01

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

  16. The utility of using customized heterochromatic flicker photometry (cHFP) to measure macular pigment in patients with age-related macular degeneration.

    PubMed

    Stringham, J M; Hammond, B R; Nolan, J M; Wooten, B R; Mammen, A; Smollon, W; Snodderly, D M

    2008-11-01

    The purpose of this study was to assess the utility and validity of using customized heterochromatic flicker photometry (cHFP) to measure macular pigment optical density (MPOD) in patients with intermediate stages of age-related macular degeneration (AMD). The measurement procedure was optimized to accommodate individual differences in temporal vision related to age, disease, or other factors. The validity criteria were based on the similarity of the spectral absorption curves to ex vivo curves of lutein and zeaxanthin and the similarity of spatial density profiles to those measured in subjects without retinal disease. Macular pigment optical density (MPOD) spatial profiles were measured with an LED-based macular densitometer; spectral absorption curves were measured with a 3-channel Maxwellian view system including a monochromator. All patients were characterized via clinical exams and all but 2 subjects from whom data were obtained had masked grading of color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System. Most of the patients were in AREDS category 2 (27%) or 3 (57%). Patients with visual acuity as poor as 20/80 were included, and could perform the task as long as they could see the stimulus. Eighty-one percent of the patients screened were able to perform the cHFP task, and data were obtained from 30 AMD patients. Spatial profiles of MPOD were measured in 19 subjects who could see the stimulus at all tested loci. These profiles were highly similar to those that have been measured with HFP in subjects without retinal disease. The average shape of the spectral absorption curves for the AMD subjects corresponded well to an ex vivo template. These data support both the utility and validity of the cHFP method for measuring MPOD in subjects with intermediate stages of AMD. The ability to measure the retinal response to nutritional intervention is of practical importance for monitoring patients being supplemented with lutein and

  17. Generation of retinal pigmented epithelium from iPSCs derived from the conjunctiva of donors with and without age related macular degeneration

    PubMed Central

    Geng, Zhouhui; Walsh, Patrick J.; Truong, Vincent; Hill, Caitlin; Ebeling, Mara; Kapphahn, Rebecca J.; Montezuma, Sandra R.; Yuan, Ching; Roehrich, Heidi; Ferrington, Deborah A.

    2017-01-01

    Fidelity in pluripotent stem cell differentiation protocols is necessary for the therapeutic and commercial use of cells derived from embryonic and induced pluripotent stem cells. Recent advances in stem cell technology, especially the widespread availability of a range of chemically defined media, substrates and differentiation components, now allow the design and implementation of fully defined derivation and differentiation protocols intended for replication across multiple research and manufacturing locations. In this report we present an application of these criteria to the generation of retinal pigmented epithelium from iPSCs derived from the conjunctiva of donors with and without age related macular degeneration. Primary conjunctival cells from human donors aged 70–85 years were reprogrammed to derive multiple iPSC lines that were differentiated into functional RPE using a rapid and defined differentiation protocol. The combination of defined iPSC derivation and culture with a defined RPE differentiation protocol, reproducibly generated functional RPE from each donor without requiring protocol adjustments for each individual. This successful validation of a standardized, iPSC derivation and RPE differentiation process demonstrates a practical approach for applications requiring the cost-effective generation of RPE from multiple individuals such as drug testing, population studies or for therapies requiring patient-specific RPE derivations. In addition, conjunctival cells are identified as a practical source of somatic cells for deriving iPSCs from elderly individuals. PMID:28282420

  18. 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 ...

  19. Monascus pigments.

    PubMed

    Feng, Yanli; Shao, Yanchun; Chen, Fusheng

    2012-12-01

    Monascus pigments (MPs) as natural food colorants have been widely utilized in food industries in the world, especially in China and Japan. Moreover, MPs possess a range of biological activities, such as anti-mutagenic and anticancer properties, antimicrobial activities, potential anti-obesity activities, and so on. So, in the past two decades, more and more attention has been paid to MPs. Up to now, more than 50 MPs have been identified and studied. However, there have been some reviews about red fermented rice and the secondary metabolites produced by Monascus, but no monograph or review of MPs has been published. This review covers the categories and structures, biosynthetic pathway, production, properties, detection methods, functions, and molecular biology of MPs.

  20. Elevated amyloid β production in senescent retinal pigment epithelium, a possible mechanism of subretinal deposition of amyloid β in age-related macular degeneration.

    PubMed

    Wang, Jiying; Ohno-Matsui, Kyoko; Morita, Ikuo

    2012-06-22

    Age-related macular degeneration (AMD) is the most common cause of legal blindness in the elderly individuals in developed countries. Subretinally-deposited amyloid β (Aβ) is a main contributor of developing AMD. However, the mechanism causing Aβ deposition in AMD eyes is unknown. Aging is the most significant risk of AMD, thus, we examined the effect of aging on subretinal Aβ deposition. mRNAs and cell lysates were isolated from retinal pigment epithelial (RPE) cells derived from 24-month-old (24M RPE) and 2-month-old (2M RPE) C57BL/6 mice. Aβ concentration in culture supernatants was measured by ELISA. Activity and expression of proteins that regulate Aβ level were examined by activity assay and real time PCR. Effect of β-secretase (BACE) on Aβ production was examined by siRNA silencing. Aβ amounts in supernatants of 24M RPE were significantly higher than 2M RPE. Activity and mRNA levels of neprilysin, an Aβ degrading enzyme, were significantly decreased in 24M RPE compared to 2M RPE. PCR analysis found that BACE2 was significantly more abundantly expressed than BACE1 in RPE cells, however, inactivation of BACE2 gene did not affect Aβ production. BACE1 protein amounts did not differ between 24M and 2M RPE, however, BACE1 activity was significantly higher in 24M RPE compared to 2M RPE. There were no significant changes in the activities of α- or γ-secretase between 2M and 24M RPE. In conclusion, RPE cells produce more amounts of Aβ when they are senescent, and this is probably caused by a decrease in Aβ degradation due to a reduction in the expression and activity of neprilysin and an increase in Aβ synthesis due to increased activity of BACE1.

  1. Oxalomalate reduces expression and secretion of vascular endothelial growth factor in the retinal pigment epithelium and inhibits angiogenesis: Implications for age-related macular degeneration.

    PubMed

    Kim, Sung Hwan; Kim, Hyunjin; Ku, Hyeong Jun; Park, Jung Hyun; Cha, Hanvit; Lee, Seoyoon; Lee, Jin Hyup; Park, Jeen-Woo

    2016-12-01

    Clinical and experimental observations indicate a critical role for vascular endothelial growth factor (VEGF), secreted by the retinal pigment epithelium (RPE), in pathological angiogenesis and the development of choroidal neovascularization (CNV) in age-related macular degeneration (AMD). RPE-mediated VEGF expression, leading to angiogenesis, is a major signaling mechanism underlying ocular neovascular disease. Inhibiting this signaling pathway with a therapeutic molecule is a promising anti-angiogenic strategy to treat this disease with potentially fewer side effects. Oxalomalate (OMA) is a competitive inhibitor of NADP(+)-dependent isocitrate dehydrogenase (IDH), which plays an important role in cellular signaling pathways regulated by reactive oxygen species (ROS). Here, we have investigated the inhibitory effect of OMA on the expression of VEGF, and the associated underlying mechanism of action, using in vitro and in vivo RPE cell models of AMD. We found that OMA reduced the expression and secretion of VEGF in RPE cells, and consequently inhibited CNV formation. This function of OMA was linked to its capacity to activate the pVHL-mediated HIF-1α degradation in these cells, partly via a ROS-dependent ATM signaling axis, through inhibition of IDH enzymes. These findings reveal a novel role for OMA in inhibiting RPE-derived VEGF expression and angiogenesis, and suggest unique therapeutic strategies for treating pathological angiogenesis and AMD development.

  2. Comparison of Progression Rate of Retinal Pigment Epithelium Loss in Patients with Neovascular Age-Related Macular Degeneration Treated with Ranibizumab and Aflibercept

    PubMed Central

    Wirth, Magdalena A.; Graf, Nicole; Becker, Matthias D.; Michels, Stephan

    2017-01-01

    Purpose. Retinal pigment epithelium (RPE) loss in neovascular age-related macular degeneration (nAMD) seem to have a linear progression but might be influenced by the treatment. The purpose of the study is the comparison of RPE loss over three years in patients treated with intravitreal ranibizumab to patients who were switched to aflibercept. Methods. A retrospective analysis with 96 eyes switched to aflibercept was conducted. The progression rate of RPE loss was evaluated in patients who showed atrophy one year prior to switch (n = 17) or on switch date (n = 19). The RPE loss was evaluated by spectral domain optical coherence tomography (SD-OCT). Further, 22 eyes from patients treated with ranibizumab were compared. Results. The median yearly progression of RPE loss after square root transformation showed no significant difference in the year prior to switch compared to the year after switch (p = 0.854). In patients who received only ranibizumab, the median yearly progression of RPE loss was 0.15 mm/y, for aflibercept patients, 0.13 mm/y. This difference was not statistically significant (p = 0.172). Conclusions. There seems to be a linear progression rate of RPE loss in patients treated with ranibizumab as well as in patients with aflibercept. No significant increase of progression rate was found after switch to aflibercept. PMID:28316836

  3. Directional protein secretion by the retinal pigment epithelium: roles in retinal health and the development of age-related macular degeneration.

    PubMed

    Kay, Paul; Yang, Yit C; Paraoan, Luminita

    2013-07-01

    The structural and functional integrity of the retinal pigment epithelium (RPE) is fundamental for maintaining the function of the neuroretina. These specialized cells form a polarized monolayer that acts as the retinal-blood barrier, separating two distinct environments with highly specialized functions: photoreceptors of the neuroretina at the apical side and Bruch's membrane/highly vascularized choriocapillaris at the basal side. The polarized nature of the RPE is essential for the health of these two regions, not only in nutrient and waste transport but also in the synthesis and directional secretion of proteins required in maintaining retinal homoeostasis and function. Although multiple malfunctions within the RPE cells have been associated with development of age-related macular degeneration (AMD), the leading cause of legal blindness, clear causative processes have not yet been conclusively characterized at the molecular and cellular level. This article focuses on the involvement of directionally secreted RPE proteins in normal functioning of the retina and on the potential association of incorrect RPE protein secretion with development of AMD. Understanding the importance of RPE polarity and the correct secretion of essential structural and regulatory components emerge as critical factors for the development of novel therapeutic strategies targeting AMD.

  4. Clearance of autophagy-associated dying retinal pigment epithelial cells – a possible source for inflammation in age-related macular degeneration

    PubMed Central

    Szatmári-Tóth, M; Kristóf, E; Veréb, Z; Akhtar, S; Facskó, A; Fésüs, L; Kauppinen, A; Kaarniranta, K; Petrovski, G

    2016-01-01

    Retinal pigment epithelial (RPE) cells can undergo different forms of cell death, including autophagy-associated cell death during age-related macular degeneration (AMD). Failure of macrophages or dendritic cells (DCs) to engulf the different dying cells in the retina may result in the accumulation of debris and progression of AMD. ARPE-19 and primary human RPE cells undergo autophagy-associated cell death upon serum depletion and oxidative stress induced by hydrogen peroxide (H2O2). Autophagy was revealed by elevated light-chain-3 II (LC3-II) expression and electron microscopy, while autophagic flux was confirmed by blocking the autophago-lysosomal fusion using chloroquine (CQ) in these cells. The autophagy-associated dying RPE cells were engulfed by human macrophages, DCs and living RPE cells in an increasing and time-dependent manner. Inhibition of autophagy by 3-methyladenine (3-MA) decreased the engulfment of the autophagy-associated dying cells by macrophages, whereas sorting out the GFP-LC3-positive/autophagic cell population or treatment by the glucocorticoid triamcinolone (TC) enhanced it. Increased amounts of IL-6 and IL-8 were released when autophagy-associated dying RPEs were engulfed by macrophages. Our data suggest that cells undergoing autophagy-associated cell death engage in clearance mechanisms guided by professional and non-professional phagocytes, which is accompanied by inflammation as part of an in vitro modeling of AMD pathogenesis. PMID:27607582

  5. Directional protein secretion by the retinal pigment epithelium: roles in retinal health and the development of age-related macular degeneration

    PubMed Central

    Kay, Paul; Yang, Yit C; Paraoan, Luminita

    2013-01-01

    The structural and functional integrity of the retinal pigment epithelium (RPE) is fundamental for maintaining the function of the neuroretina. These specialized cells form a polarized monolayer that acts as the retinal–blood barrier, separating two distinct environments with highly specialized functions: photoreceptors of the neuroretina at the apical side and Bruch's membrane/highly vascularized choriocapillaris at the basal side. The polarized nature of the RPE is essential for the health of these two regions, not only in nutrient and waste transport but also in the synthesis and directional secretion of proteins required in maintaining retinal homoeostasis and function. Although multiple malfunctions within the RPE cells have been associated with development of age-related macular degeneration (AMD), the leading cause of legal blindness, clear causative processes have not yet been conclusively characterized at the molecular and cellular level. This article focuses on the involvement of directionally secreted RPE proteins in normal functioning of the retina and on the potential association of incorrect RPE protein secretion with development of AMD. Understanding the importance of RPE polarity and the correct secretion of essential structural and regulatory components emerge as critical factors for the development of novel therapeutic strategies targeting AMD. PMID:23663427

  6. Retinal pigment epithelial acid lipase activity and lipoprotein receptors: effects of dietary omega-3 fatty acids.

    PubMed Central

    Elner, Victor M

    2002-01-01

    PURPOSE: To show that fish oil-derived omega-3 polyunsaturated fatty acids, delivered to the retinal pigment epithelium (RPE) by circulating low-density lipoproteins (LDL), enhance already considerable RPE lysosomal acid lipase activity, providing for more efficient hydrolysis of intralysosomal RPE lipids, an effect that may help prevent development of age-related macular degeneration (ARMD). METHODS: Colorimetric biochemical and histochemical techniques were used to demonstrate RPE acid lipase in situ, in vitro, and after challenge with phagocytic stimuli. Receptor-mediated RPE uptake of fluorescently labeled native, aceto-acetylated, and oxidized LDL was studied in vitro and in vivo. LDL effects on RPE lysosomal enzymes were assessed. Lysosomal enzyme activity was compared in RPE cells from monkeys fed diets rich in fish oil to those from control animals and in cultured RPE cells exposed to sera from these monkeys. RESULTS: RPE acid lipase activity was substantial and comparable to that of mononuclear phagocytes. Acid lipase activity increased significantly following phagocytic challenge with photoreceptor outer segment (POS) membranes. Receptor-mediated RPE uptake of labeled lipoproteins was determined in vitro. Distinctive uptake of labeled lipoproteins occurred in RPE cells and mononuclear phagocytes in vivo. Native LDL enhanced RPE lysosomal enzyme activity. RPE lysosomal enzymes increased significantly in RPE cells from monkeys fed fish oil-rich diets and in cultured RPE cells exposed to their sera. CONCLUSIONS: RPE cells contain substantial acid lipase for efficient metabolism of lipids imbibed by POS phagocytosis and LDL uptake. Diets rich in fish oil-derived omega-3 fatty acids, by enhancing acid lipase, may reduce RPE lipofuscin accumulation, RPE oxidative damage, and the development of ARMD. PMID:12545699

  7. Heat shock proteins as gatekeepers of proteolytic pathways-Implications for age-related macular degeneration (AMD).

    PubMed

    Kaarniranta, Kai; Salminen, Antero; Eskelinen, Eeva-Liisa; Kopitz, Jürgen

    2009-04-01

    Age-related macular degeneration (AMD) is the major diagnosis for severe and irreversible central loss of vision in elderly people in the developed countries. The loss of vision involves primarily a progressive degeneration and cell death of postmitotic retinal pigment epithelial cells (RPE), which secondarily evokes adverse effects on photoreceptor cells. The RPE cells are exposed to chronic oxidative stress from three sources: their high levels of oxygen consumption, their exposure to the high levels of lipid peroxidation derived from the photoreceptor outer segments and their exposure to constant light stimuli. Cells increase the expression of heat shock proteins (HSPs) in order to normalize their growth conditions in response to various environmental stress factors, e.g. oxidative stress. The HSPs function as molecular chaperones by preventing the accumulation of cellular cytotoxic protein aggregates and assisting in correct folding of both nascent and misfolded proteins. Increased HSPs levels are observed in the retina of AMD patients, evidence of stressed tissue. A hallmark of RPE cell aging is lysosomal lipofuscin accumulation reflecting a weakened capacity to degrade proteins in lysosomes. The presence of lipofuscin increases the misfolding of intracellular proteins, which evokes additional stress in the RPE cells. If the capacity of HSPs to repair protein damages is overwhelmed, then the proteins are mainly cleared in proteasomes or in lysosomes. In this review, we discuss the role of heat shock proteins, proteasomes, and lysosomes and autophagic processes in RPE cell proteolysis and how these might be involved in development of AMD. In addition to classical lysosomal proteolysis, we focus on the increasing evidence that, HSPs, proteasomes and autophagy regulate protein turnover in the RPE cells and thus have important roles in AMD disease.

  8. Multi-nucleate retinal pigment epithelium cells of the human macula exhibit a characteristic and highly specific distribution

    PubMed Central

    Starnes, Austin C; Huisingh, Carrie; McGwin, Gerald; Sloan, Kenneth R; Ablonczy, Zsolt; Smith, R. Theodore; Curcio, Christine A; Ach, Thomas

    2016-01-01

    Background The human retinal pigment epithelium (RPE) is reportedly 3% bi-nucleated. The importance to human vision of multi-nucleated (MN)-RPE cells could be clarified with more data about their distribution in central retina. Methods Nineteen human RPE-flatmounts (9≤51years, 10>80 years) were imaged at 12 locations: 3 eccentricities (fovea, perifovea, near periphery) in 4 quadrants (superior, inferior, temporal, nasal). Image stacks of lipofuscin-attributable autofluorescence and phalloidin labeled F-actin cytoskeleton were obtained using a confocal fluorescence microscope. Nuclei were devoid of autofluorescence and were marked using morphometric software. Cell areas were approximated by Voronoi regions. Mean number of nuclei per cell among eccentricity/quadrant groups and by age were compared using Poisson and binominal regression models. Results A total of 11403 RPE cells at 200 locations were analyzed: 94.66 % mono-, 5.31% bi-, 0.02% tri-nucleate, and 0.01% with 5 nuclei. Age had no effect on number of nuclei. There were significant regional differences: highest frequencies of MN-cells were found at the perifovea (9.9%) and near periphery (6.8%). The fovea lacked MN-cells almost entirely. The nasal quadrant had significantly more MN-cells compared to other quadrants, at all eccentricities. Conclusion This study demonstrates MN-RPE cells in human macula. MN-cells may arise due to endoreplication, cell fusion, or incomplete cell division. The topography of MN-RPE cells follows the topography of photoreceptors; with near-absence at the fovea (cones only) and high frequency at perifovea (highest rod density). This distribution might reflect specific requirements of retinal metabolism or other mechanisms addressable in further studies. PMID:26923500

  9. The marine n-3 PUFA DHA evokes cytoprotection against oxidative stress and protein misfolding by inducing autophagy and NFE2L2 in human retinal pigment epithelial cells.

    PubMed

    Johansson, Ida; Monsen, Vivi Talstad; Pettersen, Kristine; Mildenberger, Jennifer; Misund, Kristine; Kaarniranta, Kai; Schønberg, Svanhild; Bjørkøy, Geir

    2015-01-01

    Accumulation and aggregation of misfolded proteins is a hallmark of several diseases collectively known as proteinopathies. Autophagy has a cytoprotective role in diseases associated with protein aggregates. Age-related macular degeneration (AMD) is the most common neurodegenerative eye disease that evokes blindness in elderly. AMD is characterized by degeneration of retinal pigment epithelial (RPE) cells and leads to loss of photoreceptor cells and central vision. The initial phase associates with accumulation of intracellular lipofuscin and extracellular deposits called drusen. Epidemiological studies have suggested an inverse correlation between dietary intake of marine n-3 polyunsaturated fatty acids (PUFAs) and the risk of developing neurodegenerative diseases, including AMD. However, the disease-preventive mechanism(s) mobilized by n-3 PUFAs is not completely understood. In human retinal pigment epithelial cells we find that physiologically relevant doses of the n-3 PUFA docosahexaenoic acid (DHA) induce a transient increase in cellular reactive oxygen species (ROS) levels that activates the oxidative stress response regulator NFE2L2/NRF2 (nuclear factor, erythroid derived 2, like 2). Simultaneously, there is a transient increase in intracellular protein aggregates containing SQSTM1/p62 (sequestosome 1) and an increase in autophagy. Pretreatment with DHA rescues the cells from cell cycle arrest induced by misfolded proteins or oxidative stress. Cells with a downregulated oxidative stress response, or autophagy, respond with reduced cell growth and survival after DHA supplementation. These results suggest that DHA both induces endogenous antioxidants and mobilizes selective autophagy of misfolded proteins. Both mechanisms could be relevant to reduce the risk of developing aggregate-associate diseases such as AMD.

  10. Oral pigmentation: A review.

    PubMed

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

    2015-08-01

    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.

  11. 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

  12. 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...

  13. 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

  14. Functionally impaired, hypertrophic ECL cells accumulate vacuoles and lipofuscin bodies. An ultrastructural study of ECL cells isolated from hypergastrinemic rats.

    PubMed

    Zhao, C M; Bakke, I; Tostrup-Skogaker, N; Waldum, H L; Håkanson, R; Chen, D

    2001-03-01

    ECL cells in the oxyntic mucosa of stomach control gastric acid secretion by mobilizing histamine in response to gastrin. They respond to gastrin also with hypertrophy and hyperplasia. ECL cells exhibit functional impairment upon long-term gastrin stimulation. The impairment is manifested in a gradual decline of the activity of the histamine-forming enzyme per individual ECL cell and in a failure of gastrin to mobilize histamine. The mechanism behind this impairment is unknown. In the present study, rats were treated with the proton pump inhibitor pantoprazole for 45 days to induce sustained hypergastrinemia. The ECL cells were isolated from normogastrinemic and hypergastrinemic rats and size-separated from other mucosal cells by the elutriation technique. The total ECL cell number was twofold higher in hypergastrinemic rats than in normogastrinemic rats, and most of the cells appeared in elutriation fractions where large cells predominate. The ECL cells of the different fractions were analyzed by quantitative electron microscopy. Normal-sized ECL cells from hypergastrinemic rats displayed a reduced number of secretory vesicles (probably because of degranulation) compared with normal-sized ECL cells from normogastrinemic rats. Hypertrophic ECL cells from hypergastrinemic rats had an unchanged number of secretory vesicles, supporting the view that such cells fail to respond to gastrin with degranulation. Although both normal-sized and hypertrophic ECL cells from hypergastrinemic rats contained vacuoles, those in the hypertrophic ECL cells were larger and more numerous. In addition, hypertrophic ECL cells were found to contain numerous, prominent lipofuscin bodies which are the presumed end product of crinophagia. Conceivably therefore, large vacuoles and lipofuscin bodies cause functional impairment of the hypertrophic ECL cells.

  15. Antioxidant activity and delayed aging effects of hot water extract from Chamaecyparis obtusa var. formosana leaves.

    PubMed

    Cheng, Szu-Chin; Li, Wen-Hsuan; Shi, Yeu-Ching; Yen, Pei-Ling; Lin, Huan-You; Liao, Vivian Hsiu-Chuan; Chang, Shang-Tzen

    2014-05-07

    The antioxidant activity and delayed aging effects of hot water extracts from leaves of Chamaecyparis obtusa var. formosana were investigated. Free radical, superoxide radical scavenging, and total phenolic content assays were employed to evaluate the in vitro activities of the extracts. In addition, in vivo assays using the nematode Caenorhabditis elegans were also performed in this study. The results showed that among all soluble fractions obtained from the extracts, the ethyl acetate-soluble fraction has the best in vitro and in vivo antioxidant activities. Moreover, it decreased significantly the deposition of lipofuscin (aging pigment) and extended the lifespan of C. elegans. Bioactivity-guided fractionation yielded six potent antioxidant constituents from the ethyl acetate-soluble fraction, namely, catechin, quercetin, quercetin-3-O-α-rhamnoyranoside, myricetin-3-O-α-rhamnoyranoside, vanillic acid, and 4-hydroxybenzoic acid. Quercetin-3-O-α-rhamnoyranoside pretreatment showed the highest survival of C. elegans upon juglone exposure. Taken together, the results revealed that hot water extracts from C. obtusa var. formosana leaves have the potential to be used as a source for antioxidant or delayed aging health food.

  16. The biochemical estimation of age in Euphausiids: Laboratory calibration and field comparisons

    NASA Astrophysics Data System (ADS)

    Harvey, H. R.; Ju, Se-J.; Son, S.-K.; Feinberg, L. R.; Shaw, C. T.; Peterson, W. T.

    2010-04-01

    Euphausiids play a key role in many marine ecosystems as a link between primary producers and top predators. Understanding their demographic (i.e. age) structure is an essential tool to assess growth and recruitment as well as to determine how changes in environmental conditions might alter their condition and distribution. Age determination of crustaceans cannot be accomplished using traditional approaches, and here we evaluate the potential for biochemical products of tissue metabolism (termed lipofuscins) to determine the demographic structure of euphausiids in field collections . Lipofuscin was extracted from krill neural tissues (eye and eye-stalk), quantified using fluorescent intensity and normalized to tissue protein content to allow comparisons across animal sizes. Multiple fluorescent components from krill were observed, with the major product having a maximum fluorescence at excitation of 355 nm and emission of 510 nm. Needed age calibration of lipofuscin accumulation in Euphausia pacifica was accomplished using known-age individuals hatched and reared in the laboratory for over one year. Lipofuscin content extracted from neural tissues of laboratory-reared animals was highly correlated with the chronological age of animals ( r=0.87). Calibrated with laboratory lipofuscin accumulation rates, field-collected sub-adult and adult E. pacifica in the Northeast Pacific were estimated to be older than 100 days and younger than 1year. Comparative data for the Antarctic krill, E. superba showed much higher lipofuscin values suggesting a much longer lifespan than the more temperate species, E. pacifica. These regional comparisons suggest that biochemical indices allow a practical approach to estimate population age structure of diverse populations, and combined with other measurements can provide estimates of vital rates (i.e. longevity, mortality, growth) for krill populations in dynamic environments.

  17. Macular pigment and lutein supplementation in choroideremia.

    PubMed

    Duncan, Jacque L; Aleman, Tomas S; Gardner, Leigh M; De Castro, Elaine; Marks, Daniel A; Emmons, Jessica M; Bieber, Michelle L; Steinberg, Janet D; Bennett, Jean; Stone, Edwin M; MacDonald, Ian M; Cideciyan, Artur V; Maguire, Maureen G; Jacobson, Samuel G

    2002-03-01

    Choroideremia is an incurable X-linked retinal degeneration caused by mutations in the gene encoding Rab escort protein-1. A group of clinically defined and genotyped patients were studied to determine: (1) the degree of rod and cone dysfunction and structural abnormality in the central retina and the level of macular pigment; and (2) the response of macular pigment and foveal vision to a 6 month trial of supplementation with oral lutein (at 20 mg per day). Rod and cone-mediated function was measured with dark-adapted static perimetry; in vivo retinal structure was determined with optical coherence tomography; and macular pigment optical density was measured with heterochromatic flicker photometry. In this cohort of patients (ages 15-65 years), both rod- and cone-mediated central function declined with age as did central retinal thickness. Macular pigment levels did not differ between patients and male control subjects. Supplementation of oral lutein in a subset of patients led to an increase in serum lutein and macular pigment levels; absolute foveal sensitivity did not change. It is concluded that macular pigment density can be augmented by oral intake of lutein in patients with choroideremia. There was no short-term change in the central vision of the patients on the supplement, but long-term influences of lutein supplementation on disease natural history warrant further study.

  18. Oxidative damage and cellular defense mechanisms in sea urchin models of aging.

    PubMed

    Du, Colin; Anderson, Arielle; Lortie, Mae; Parsons, Rachel; Bodnar, Andrea

    2013-10-01

    The free radical, or oxidative stress, theory of aging proposes that the accumulation of oxidative cellular damage is a major contributor to the aging process and a key determinant of species longevity. This study investigates the oxidative stress theory in a novel model for aging research, the sea urchin. Sea urchins present a unique model for the study of aging because of the existence of species with tremendously different natural life spans, including some species with extraordinary longevity and negligible senescence. Cellular oxidative damage, antioxidant capacity, and proteasome enzyme activities were measured in the tissues of three sea urchin species: short-lived Lytechinus variegatus, long-lived Strongylocentrotus franciscanus, and Strongylocentrotus purpuratus, which has an intermediate life span. Levels of protein carbonyls and 4-hydroxynonenal measured in tissues (muscle, nerve, esophagus, gonad, coelomocytes, ampullae) and 8-hydroxy-2'-deoxyguanosine measured in cell-free coelomic fluid showed no general increase with age. The fluorescent age pigment lipofuscin, measured in muscle, nerve, and esophagus, increased with age; however, it appeared to be predominantly extracellular. Antioxidant mechanisms (total antioxidant capacity, superoxide dismutase) and proteasome enzyme activities were maintained with age. In some instances, levels of oxidative damage were lower and antioxidant activity higher in cells or tissues of the long-lived species compared to the short-lived species; however, further studies are required to determine the relationship between oxidative damage and longevity in these animals. Consistent with the predictions of the oxidative stress theory of aging, the results suggest that negligible senescence is accompanied by a lack of accumulation of cellular oxidative damage with age, and maintenance of antioxidant capacity and proteasome enzyme activities may be important mechanisms to mitigate damage.

  19. Oxidative Damage and Cellular Defense Mechanisms in Sea Urchin Models of Aging

    PubMed Central

    Du, Colin; Anderson, Arielle; Lortie, Mae; Parsons, Rachel; Bodnar, Andrea

    2013-01-01

    The free radical or oxidative stress theory of aging proposes that the accumulation of oxidative cellular damage is a major contributor to the aging process and a key determinant of species longevity. This study investigates the oxidative stress theory in a novel model for aging research, the sea urchin. Sea urchins present a unique model for the study of aging due to the existence of species with tremendously different natural life spans including some species with extraordinary longevity and negligible senescence. Cellular oxidative damage, antioxidant capacity and proteasome enzyme activities were measured in the tissues of three sea urchin species: short-lived Lytechinus variegatus, long-lived Strongylocentrotus franciscanus and Strongylocentrotus purpuratus which has an intermediate lifespan. Levels of protein carbonyls and 4-hydroxynonenal (HNE) measured in tissues (muscle, nerve, esophagus, gonad, coelomocytes, ampullae) and 8-hydroxy-2’-deoxyguanosine (8-OHdG) measured in cell-free coelomic fluid showed no general increase with age. The fluorescent age-pigment lipofuscin measured in muscle, nerve and esophagus, increased with age however it appeared to be predominantly extracellular. Antioxidant mechanisms (total antioxidant capacity, superoxide dismutase) and proteasome enzyme activities were maintained with age. In some instances, levels of oxidative damage were lower and antioxidant activity higher in cells or tissues of the long-lived species compared to the short-lived species, however further studies are required to determine the relationship between oxidative damage and longevity in these animals. Consistent with the predictions of the oxidative stress theory of aging, the results suggest that negligible senescence is accompanied by a lack of accumulation of cellular oxidative damage with age and maintenance of antioxidant capacity and proteasome enzyme activities may be important mechanisms to mitigate damage. PMID:23707327

  20. Aryl hydrocarbon receptor deficiency causes dysregulated cellular matrix metabolism and age-related macular degeneration-like pathology

    PubMed Central

    Hu, Peng; Herrmann, Rolf; Bednar, Amanda; Saloupis, Peter; Dwyer, Mary A.; Yang, Ping; Qi, Xiaoping; Thomas, Russell S.; Jaffe, Glenn J.; Boulton, Michael E.; McDonnell, Donald P.; Malek, Goldis

    2013-01-01

    The aryl hydrocarbon receptor (AhR) is a nuclear receptor that regulates xenobiotic metabolism and detoxification. Herein, we report a previously undescribed role for the AhR signaling pathway as an essential defense mechanism in the pathogenesis of early dry age-related macular degeneration (AMD), the leading cause of vision loss in the elderly. We found that AhR activity and protein levels in human retinal pigment epithelial (RPE) cells, cells vulnerable in AMD, decrease with age. This finding is significant given that age is the most established risk factor for development of AMD. Moreover, AhR−/− mice exhibit decreased visual function and develop dry AMD-like pathology, including disrupted RPE cell tight junctions, accumulation of RPE cell lipofuscin, basal laminar and linear-like deposit material, Bruch’s membrane thickening, and progressive RPE and choroidal atrophy. High-serum low-density lipoprotein levels were also observed in AhR−/− mice. In its oxidized form, this lipoprotein can stimulate increased secretion of extracellular matrix molecules commonly found in deposits from RPE cells, in an AhR-dependent manner. This study demonstrates the importance of cellular clearance via the AhR signaling pathway in dry AMD pathogenesis, implicating AhR as a potential target, and the mouse model as a useful platform for validating future therapies. PMID:24106308

  1. 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

  2. Ion transport in pigmentation.

    PubMed

    Bellono, Nicholas W; Oancea, Elena V

    2014-12-01

    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.

  3. miR-146a is upregulated during retinal pigment epithelium (RPE)/choroid aging in mice and represses IL-6 and VEGF-A expression in RPE cells

    PubMed Central

    Hao, Yi; Zhou, Qinbo; Ma, Jing; Zhao, Yun; Wang, Shusheng

    2016-01-01

    Purpose MicroRNA-146a (miR-146a) has been proposed as a marker for age-associated inflammation, or “inflammaging”, acting as a negative regulator of cellular senescence and pro-inflammatory signaling pathways. However, the regulation and function of miR-146 during ocular aging remains unclear. Here we propose that miR-146 is regulated during aging of the retina and choroid, and functions in retinal pigment epithelial (RPE) cells to regulate key genes involved in inflammation and angiogenesis. Methods The expression of miR-146a and miR-146b was examined in the neuroretina and RPE/choroid in mice aged from 2 months to 24 months. Then, the effect of synthetic miR-146a mimetic on IL-6 and VEGF-A expression was analyzed in RPE cells treated with and without TNF-α. Results miR-146a and miR-146b was upregulated during aging of RPE/choroid but not neuroretina, supporting tissue-specific regulation of aging-related miRNAs in retinal tissues. Overexpression of miR-146a by miRNA mimics inhibited VEGF-A and TNF-α-induced IL-6 expression. Conclusions Elevation of miR-146a and miR-146b in the aging RPE/choroid but not neuroretina suggests a role for miRNAs in inflammaging in the RPE/choroid. miR-146a overexpression inhibits the expression IL-6 and VEGF-A in the RPE cells, supporting a negative feedback regulation mechanism by which inflammatory pathways may be dysregulated in RPE during aging. PMID:27917303

  4. 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

  5. Photosynthetic Pigments in Diatoms.

    PubMed

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

    2015-09-16

    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.

  6. Oxidative stress, hypoxia, and autophagy in the neovascular processes of age-related macular degeneration.

    PubMed

    Blasiak, Janusz; Petrovski, Goran; Veréb, Zoltán; Facskó, Andrea; Kaarniranta, Kai

    2014-01-01

    Age-related macular degeneration (AMD) is the leading cause of severe and irreversible loss of vision in the elderly in developed countries. AMD is a complex chronic neurodegenerative disease associated with many environmental, lifestyle, and genetic factors. Oxidative stress and the production of reactive oxygen species (ROS) seem to play a pivotal role in AMD pathogenesis. It is known that the macula receives the highest blood flow of any tissue in the body when related to size, and anything that can reduce the rich blood supply can cause hypoxia, malfunction, or disease. Oxidative stress can affect both the lipid rich retinal outer segment structure and the light processing in the macula. The response to oxidative stress involves several cellular defense reactions, for example, increases in antioxidant production and proteolysis of damaged proteins. The imbalance between production of damaged cellular components and degradation leads to the accumulation of detrimental products, for example, intracellular lipofuscin and extracellular drusen. Autophagy is a central lysosomal clearance system that may play an important role in AMD development. There are many anatomical changes in retinal pigment epithelium (RPE), Bruch's membrane, and choriocapillaris in response to chronic oxidative stress, hypoxia, and disturbed autophagy and these are estimated to be crucial components in the pathology of neovascular processes in AMD.

  7. Understanding age-related macular degeneration (AMD): relationships between the photoreceptor/retinal pigment epithelium/Bruch's membrane/choriocapillaris complex.

    PubMed

    Bhutto, Imran; Lutty, Gerard

    2012-08-01

    There is a mutualistic symbiotic relationship between the components of the photoreceptor/retinal pigment epithelium (RPE)/Bruch's membrane (BrMb)/choriocapillaris (CC) complex that is lost in AMD. Which component in the photoreceptor/RPE/BrMb/CC complex is affected first appears to depend on the type of AMD. In atrophic AMD (~85-90% of cases), it appears that large confluent drusen formation and hyperpigmentation (presumably dysfunction in RPE) are the initial insult and the resorption of these drusen and loss of RPE (hypopigmentation) can be predictive for progression of geographic atrophy (GA). The death and dysfunction of photoreceptors and CC appear to be secondary events to loss in RPE. In neovascular AMD (~10-15% of cases), the loss of choroidal vasculature may be the initial insult to the complex. Loss of CC with an intact RPE monolayer in wet AMD has been observed. This may be due to reduction in blood supply because of large vessel stenosis. Furthermore, the environment of the CC, basement membrane and intercapillary septa, is a proinflammatory milieu with accumulation of complement components as well as proinflammatory molecules like CRP during AMD. In this toxic milieu, CC die or become dysfunction making adjacent RPE hypoxic. These hypoxic cells then produce angiogenic substances like VEGF that stimulate growth of new vessels from CC, resulting in choroidal neovascularization (CNV). The loss of CC might also be a stimulus for drusen formation since the disposal system for retinal debris and exocytosed material from RPE would be limited. Ultimately, the photoreceptors die of lack of nutrients, leakage of serum components from the neovascularization, and scar formation. Therefore, the mutualistic symbiotic relationship within the photoreceptor/RPE/BrMb/CC complex is lost in both forms of AMD. Loss of this functionally integrated relationship results in death and dysfunction of all of the components in the complex.

  8. Inflammation and its role in age-related macular degeneration.

    PubMed

    Kauppinen, Anu; Paterno, Jussi J; Blasiak, Janusz; Salminen, Antero; Kaarniranta, Kai

    2016-05-01

    Inflammation is a cellular response to factors that challenge the homeostasis of cells and tissues. Cell-associated and soluble pattern-recognition receptors, e.g. Toll-like receptors, inflammasome receptors, and complement components initiate complex cellular cascades by recognizing or sensing different pathogen and damage-associated molecular patterns, respectively. Cytokines and chemokines represent alarm messages for leukocytes and once activated, these cells travel long distances to targeted inflamed tissues. Although it is a crucial survival mechanism, prolonged inflammation is detrimental and participates in numerous chronic age-related diseases. This article will review the onset of inflammation and link its functions to the pathogenesis of age-related macular degeneration (AMD), which is the leading cause of severe vision loss in aged individuals in the developed countries. In this progressive disease, degeneration of the retinal pigment epithelium (RPE) results in the death of photoreceptors, leading to a loss of central vision. The RPE is prone to oxidative stress, a factor that together with deteriorating functionality, e.g. decreased intracellular recycling and degradation due to attenuated heterophagy/autophagy, induces inflammation. In the early phases, accumulation of intracellular lipofuscin in the RPE and extracellular drusen between RPE cells and Bruch's membrane can be clinically detected. Subsequently, in dry (atrophic) AMD there is geographic atrophy with discrete areas of RPE loss whereas in the wet (exudative) form there is neovascularization penetrating from the choroid to retinal layers. Elevations in levels of local and systemic biomarkers indicate that chronic inflammation is involved in the pathogenesis of both disease forms.

  9. Lipofuscin-like granules of the juxtaglomerular apparatus of the kidney. The diagnostic significance of a quasi-normal subcellular structure incidentally encountered in the course of routine ultrastructural evaluation of renal biopsies.

    PubMed

    Bisceglia, Michele; Carosi, Illuminato; D'Errico, Michele; Di Giorgio, Giuseppe; Castagnoli, Anna; Pasquinelli, Gianandrea

    2011-02-15

    Lipofuscin-like granules, first described by Biava and West in 1965, are a subcellular, quasi-physiologic finding mainly seen in the smooth muscle cells of renal arterioles, but also in juxtaglomerular cells and the lacis cells of human kidneys. They increase in number in subjects affected by arterial hypertension and diabetes. They do not correlate with a specific primary renal disease. Lipofuscin-like granules are not related to renin granules. The world literature on this subject is almost non-existent, and the awareness of this finding or its clinical significance among either pathologists or nephrologists is very poor. We incidentally observed these lipofuscin-like granules in 8 cases during the routine electron microscope examination of 440 renal biopsies, and report herein on their ultrastructural features. Six of these 8 patients were affected by arterial hypertension, one of whom was also concomitantly affected by diabetes mellitus. These lipofuscin-like granules appear as dense bodies with a lipid component, a coarsely granular matrix, and a crystalloid component which may appear in a band or dot pattern, according to the plane of sectioning. The pathologist has to be aware of these lipofuscin-like granules in order not to confuse them with the semicircularly organized (fingerprint) linear immune deposits associated with some specific glomerulopathies.

  10. Acacetin promotes healthy aging by altering stress response in Caenorhabditis elegans.

    PubMed

    Asthana, Jyotsna; Mishra, B N; Pandey, Rakesh

    2016-08-01

    The progression in lifespan has been associated with elevated intracellular reactive oxygen species (ROS) and oxidative stress level which contributes to development of age related disorders. The discovery of lifespan modulating phytomolecules may promote development of natural therapies against age related afflictions. Acacetin (5,7-dihydroxy-4-methoxyflavone), is a naturally occurring flavonoid known to possess therapeutic properties. To this end, the present study evaluates effect of acacetin (AC) on lifespan, stress and neurotoxicity for the first time by using well-established free living, multicellular Caenorhabditis elegans model system. The 25 μM dose of AC significantly prolonged the mean lifespan of worms by 27.31% in comparison to untreated control and other tested doses of AC. Additionally, AC enhanced stress resistance against oxidative and thermal stress in worms. Furthermore, AC attenuated age related intracellular ROS level, aggregation of age pigment lipofuscin and increased the mean survival in stress hypersensitive mev-1 mutant by 40.5%. AC supplementation also reduced the alpha synuclein aggregation in transgenic worm model of Parkinson's disease. The enhanced stress resistance, lifespan and alleviation of age related pathology can be attributed to increment in stress modulatory enzymes like superoxide dismutase (SOD) and catalase (CAT) level. Altogether the results suggest AC exposure maintains stress level, health span and extends mean lifespan of C. elegans. The longevity promoting and neuromodulatory effects of AC are mediated by up regulation of the stress response genes sod-3 and gst-4. The present finding gives new insights of natural remedies and their future prospects in developing therapeutic interventions for managing age related diseases.

  11. 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.

  12. Design, Synthesis, and Evaluation of Nonretinoid Retinol Binding Protein 4 Antagonists for the Potential Treatment of Atrophic Age-Related Macular Degeneration and Stargardt Disease

    PubMed Central

    2015-01-01

    Accumulation of lipofuscin in the retina is associated with pathogenesis of atrophic age-related macular degeneration and Stargardt disease. Lipofuscin bisretinoids (exemplified by N-retinylidene-N-retinylethanolamine) seem to mediate lipofuscin toxicity. Synthesis of lipofuscin bisretinoids depends on the influx of retinol from serum to the retina. Compounds antagonizing the retinol-dependent interaction of retinol-binding protein 4 (RBP4) with transthyretin in the serum would reduce serum RBP4 and retinol and inhibit bisretinoid formation. We recently showed that A1120 (3), a potent carboxylic acid based RBP4 antagonist, can significantly reduce lipofuscin bisretinoid formation in the retinas of Abca4–/– mice. As part of the NIH Blueprint Neurotherapeutics Network project we undertook the in vitro exploration to identify novel conformationally flexible and constrained RBP4 antagonists with improved potency and metabolic stability. We also demonstrate that upon acute and chronic dosing in rats, 43, a potent cyclopentyl fused pyrrolidine antagonist, reduced circulating plasma RBP4 protein levels by approximately 60%. PMID:25210858

  13. Design, synthesis, and evaluation of nonretinoid retinol binding protein 4 antagonists for the potential treatment of atrophic age-related macular degeneration and Stargardt disease.

    PubMed

    Cioffi, Christopher L; Dobri, Nicoleta; Freeman, Emily E; Conlon, Michael P; Chen, Ping; Stafford, Douglas G; Schwarz, Daniel M C; Golden, Kathy C; Zhu, Lei; Kitchen, Douglas B; Barnes, Keith D; Racz, Boglarka; Qin, Qiong; Michelotti, Enrique; Cywin, Charles L; Martin, William H; Pearson, Paul G; Johnson, Graham; Petrukhin, Konstantin

    2014-09-25

    Accumulation of lipofuscin in the retina is associated with pathogenesis of atrophic age-related macular degeneration and Stargardt disease. Lipofuscin bisretinoids (exemplified by N-retinylidene-N-retinylethanolamine) seem to mediate lipofuscin toxicity. Synthesis of lipofuscin bisretinoids depends on the influx of retinol from serum to the retina. Compounds antagonizing the retinol-dependent interaction of retinol-binding protein 4 (RBP4) with transthyretin in the serum would reduce serum RBP4 and retinol and inhibit bisretinoid formation. We recently showed that A1120 (3), a potent carboxylic acid based RBP4 antagonist, can significantly reduce lipofuscin bisretinoid formation in the retinas of Abca4(-/-) mice. As part of the NIH Blueprint Neurotherapeutics Network project we undertook the in vitro exploration to identify novel conformationally flexible and constrained RBP4 antagonists with improved potency and metabolic stability. We also demonstrate that upon acute and chronic dosing in rats, 43, a potent cyclopentyl fused pyrrolidine antagonist, reduced circulating plasma RBP4 protein levels by approximately 60%.

  14. Determination of pigments in vegetables.

    PubMed

    Schoefs, Benoît

    2004-10-29

    Plant pigments are responsible for the shining color of plant tissues. They are also found in animal tissues and, eventually in transformed food products as additives. These pigments have an important impact on the commercial value of products, because the colors establish the first contact with the consumer. In addition plant pigments may have an influence on the health of the consumers. Pigments are labile: they can be easily altered, and even destroyed. Analytical processes have been developed to determine pigment composition. The aim of this paper is to provide a brief overview of these methods.

  15. Terahertz Analysis of Quinacridone Pigments

    NASA Astrophysics Data System (ADS)

    Squires, A. D.; Kelly, M.; Lewis, R. A.

    2017-03-01

    We present terahertz spectroscopy and analysis of two commercially available quinacridone pigments in the 0.5-4.5 THz range. Our results show a clear distinction between quinacridone red and magenta pigments. We reveal four definite absorptions in the terahertz regime common to both pigments, but offset between the pigments by ˜0.2 THz. The lowest-energy line in each pigment is observed to increase in frequency by ˜0.1 THz as the temperature is reduced from 300 to 12 K.

  16. 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

  17. Chronic stress induces ageing-associated degeneration in rat Leydig cells

    PubMed Central

    Wang, Fei-Fei; Wang, Qian; Chen, Yong; Lin, Qiang; Gao, Hui-Bao; Zhang, Ping

    2012-01-01

    Several studies have suggested that stress and ageing exert inhibitory effects on rat Leydig cells. In a pattern similar to the normal process of Leydig cell ageing, stress-mediated increases in glucocorticoid levels inhibit steroidogenic enzyme expression that then results in decreased testosterone secretion. We hypothesized that chronic stress accelerates the degenerative changes associated with ageing in Leydig cells. To test this hypothesis, we established a model of chronic stress to evaluate stress-induced morphological and functional alterations in Brown Norway rat Leydig cells; additionally, intracellular lipofuscin levels, reactive oxygen species (ROS) levels and DNA damage were assessed. The results showed that chronic stress accelerated ageing-related changes: ultrastructural alterations associated with ageing, cellular lipofuscin accumulation, increased ROS levels and more extensive DNA damage were observed. Additionally, testosterone levels were decreased. This study sheds new light on the idea that chronic stress contributes to the degenerative changes associated with ageing in rat Leydig cells in vivo. PMID:22609820

  18. Resonant imaging of carotenoid pigments in the human retina

    NASA Astrophysics Data System (ADS)

    Gellermann, Werner; Emakov, Igor V.; McClane, Robert W.

    2002-06-01

    We have generated high spatial resolution images showing the distribution of carotenoid macular pigments in the human retina using Raman spectroscopy. A low level of macular pigments is associated with an increased risk of developing age-related macular degeneration, a leading cause of irreversible blindness. Using excised human eyecups and resonant excitation of the pigment molecules with narrow bandwidth blue light from a mercury arc lamp, we record Raman images originating from the carbon-carbon double bond stretch vibrations of lutein and zeaxanthin, the carotenoids comprising human macular pigments. Our Raman images reveal significant differences among subjects, both in regard to absolute levels as well as spatial distribution within the macula. Since the light levels used to obtain these images are well below established safety limits, this technique holds promise for developing a rapid screening diagnostic in large populations at risk for vision loss from age-related macular degeneration.

  19. 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

  20. 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

  1. Energy Conserving Coating - Pigment Research

    DTIC Science & Technology

    1991-05-01

    indicated above, changes from yellow to orange. Thermochromic CVL Mixtures Thermochromic dye mixtures were made by reacting specific leuco (colorless...2 Photochromic Pigments and Dyes ................................. 3 Thermochromic Inorganic Pigments...describing the state of the art in color changing materials, from liquid crystals to thermochromic metal complexes to photochromic spiran dyes . The re- search

  2. 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.

  3. Nonphotosynthetic Pigments as Potential Biosignatures

    NASA Astrophysics Data System (ADS)

    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.

  4. 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.

  5. Electrochemical photodegradation study of semiconductor pigments: influence of environmental parameters.

    PubMed

    Anaf, Willemien; Trashin, Stanislav; Schalm, Olivier; van Dorp, Dennis; Janssens, Koen; De Wael, Karolien

    2014-10-07

    Chemical transformations in paintings often induce discolorations, disturbing the appearance of the image. For an appropriate conservation of such valuable and irreplaceable heritage objects, it is important to have a good know-how on the degradation processes of the (historical) materials: which pigments have been discolored, what are the responsible processes, and which (environmental) conditions have the highest impact on the pigment degradation and should be mitigated. Pigment degradation is already widely studied, either by analyzing historical samples or by accelerated weathering experiments on dummies. However, in historic samples several processes may have taken place, increasing the complexity of the current state, while aging experiments are time-consuming due to the often extended aging period. An alternative method is proposed for a fast monitoring of degradation processes of semiconductor pigments, using an electrochemical setup mimicking the real environment and allowing the identification of harmful environmental parameters for each pigment. Examples are given for the pigments cadmium yellow (CdS) and vermilion (α-HgS).

  6. 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.

  7. Iris phenotypes and pigment dispersion caused by genes influencing pigmentation.

    PubMed

    Anderson, Michael G; Hawes, Norman L; Trantow, Colleen M; Chang, Bo; John, Simon W M

    2008-10-01

    Spontaneous mutations altering mouse coat colors have been a classic resource for discovery of numerous molecular pathways. Although often overlooked, the mouse iris is also densely pigmented and easily observed, thus representing a similarly powerful opportunity for studying pigment cell biology. Here, we present an analysis of iris phenotypes among 16 mouse strains with mutations influencing melanosomes. Many of these strains exhibit biologically and medically relevant phenotypes, including pigment dispersion, a common feature of several human ocular diseases. Pigment dispersion was identified in several strains with mutant alleles known to influence melanosomes, including beige, light, and vitiligo. Pigment dispersion was also detected in the recently arising spontaneous coat color variant, nm2798. We have identified the nm2798 mutation as a missense mutation in the Dct gene, an identical re-occurrence of the slaty light mutation. These results suggest that dysregulated events of melanosomes can be potent contributors to the pigment dispersion phenotype. Combined, these findings illustrate the utility of studying iris phenotypes as a means of discovering new pathways, and re-linking old ones, to processes of pigmented cells in health and disease.

  8. [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.

  9. 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

  10. Murine Ccl2/Cx3cr1 Deficiency Results in Retinal Lesions Mimicking Human Age-Related Macular Degeneration

    PubMed Central

    Tuo, Jingsheng; Bojanowski, Christine M.; Zhou, Min; Shen, Defen; Ross, Robert J.; Rosenberg, Kevin I.; Cameron, D. Joshua; Yin, Chunyue; Kowalak, Jeffrey A.; Zhuang, Zhengping; Zhang, Kang; Chan, Chi-Chao

    2007-01-01

    Purpose Senescent Ccl2-/- mice are reported to develop cardinal features of human age-related macular degeneration (AMD). Loss-of-function single-nucleotide polymorphisms within CX3CR1 are also found to be associated with AMD. The authors generated Ccl2-/-/Cx3cr1-/- mice to establish a more characteristic and reproducible AMD model. Methods Single Ccl2- and Cx3cr1-deficient mice were crossbred to obtain Ccl2-/-/Cx3cr1-/- mice. Funduscopy, histopathology, retinal A2E quantification, proteomics, RT-PCR gene expression assay, immunochemistry, and Western blotting were used to examine the retina and to evaluate gene expression within the retinal tissue. Results By 6 weeks of age, all Ccl2-/-/Cx3cr1-/- mice developed AMD-like retinal lesions, including drusen, retinal pigment epithelium alteration, and photoreceptor degeneration. Furthermore, choroidal neovascularization occurred in 15% of the mice. These degenerative lesions progressed with age. A2E, a major lipofuscin fluorophore that accumulated during AMD progression, was significantly higher in the Ccl2-/-/Cx3cr1-/- retina than in the wild-type retina. Complement cofactor was higher in the Ccl2-/-/Cx3cr1-/- RPE. Proteomics data indicated that four proteins were differentially expressed in Ccl2-/-/Cx3cr1-/- retina compared with control. One of these proteins, ERp29, an endoplasmic reticulum protein, functions as an escort chaperone and in protein folding. Conclusions The authors concluded that Ccl2-/-/Cx3cr1-/- mice develop a broad spectrum of AMD abnormalities with early onset and high penetrance. These observations implicate certain chemokines and endoplasmic reticulum proteins in AMD pathogenesis. Similar to the mechanism of neurodegeneration caused by dysfunction of endoplasmic reticulum proteins, decreased chaperoning may cause misfolded protein accumulation, leading to drusen formation and retinal degeneration. PMID:17652758

  11. Aging changes in hair and nails

    MedlinePlus

    ... of aging. Hair color is due to a pigment called melanin , which hair follicles produce. Follicles are ... slows. Hair strands become smaller and have less pigment. So the thick, coarse hair of a young ...

  12. Protein Oxidation in Aging: Does It Play a Role in Aging Progression?

    PubMed Central

    Reeg, Sandra

    2015-01-01

    Abstract Significance: A constant accumulation of oxidized proteins takes place during aging. Oxidation of proteins leads to a partial unfolding and, therefore, to aggregation. Protein aggregates impair the activity of cellular proteolytic systems (proteasomes, lysosomes), resulting in further accumulation of oxidized proteins. In addition, the accumulation of highly crosslinked protein aggregates leads to further oxidant formation, damage to macromolecules, and, finally, to apoptotic cell death. Furthermore, protein oxidation seems to play a role in the development of various age-related diseases, for example, neurodegenerative diseases. Recent Advances: The highly oxidized lipofuscin accumulates during aging. Lipofuscin formation might cause impaired lysosomal and proteasomal degradation, metal ion accumulation, increased reactive oxygen species formation, and apoptosis. Critical Issues: It is still unclear to which extent protein oxidation is involved in the progression of aging and in the development of some age-related diseases. Future Directions: An extensive knowledge of the effects of protein oxidation on the aging process and its contribution to the development of age-related diseases could enable further strategies to reduce age-related impairments. Strategies aimed at lowering aggregate formation might be a straightforward intervention to reduce age-related malfunctions of organs. Antioxid. Redox Signal. 23, 239–255. PMID:25178482

  13. 'Shadow sign' in congenital hypertrophy of the retinal pigment epithelium of young myopic pigmented patients.

    PubMed

    Chang, M Y; McBeath, J B; McCannel, C A; McCannel, T A

    2016-01-01

    PURPOSE Congenital hypertrophy of the retinal pigment epithelium (CHRPE) may simulate choroidal melanoma in certain cases. We report unique clinical features we have observed in cases of CHRPE in young myopic pigmented patients.METHODS Patients who were referred for evaluation of a suspicious choroidal lesion and found to have a CHRPE lesion with the clinical appearance of lesion elevation and a subretinal fluid-like 'shadow sign' were included. Patient and lesion characteristics were tabulated. Available images, including fundus photography, ultrasonography, optical coherence tomography (OCT), and fluorescein angiography (FA) were reviewed.ResultsSix patients were included. The 'shadow sign' was anterior to the CHRPE lesion in all cases. The mean age of the patients was 27.3 years. The ethnicities of the patients were Chinese (n=1), Hispanic (n=3), or African-American (n=2). Five of six patients were myopic.CONCLUSIONS Although most CHRPE lesions appear flat on ophthalmoscopy, lesions in young myopic patients of pigmented ethnicities may appear elevated with a 'shadow sign' due to 'dark without pressure.' This new finding may be related to the vitreoretinal interface in young myopic pigmented patients and must be distinguished from true subretinal fluid and lesion thickness, which are often observed in choroidal melanoma.

  14. Dermoscopy of pigmented skin lesions.

    PubMed

    Soyer, H P; Argenziano, G; Chimenti, S; Ruocco, V

    2001-01-01

    This paper describes the basic concepts of dermoscopy, the various dermoscopic equipments and the standard criteria for diagnosing pigmented skin lesions. In assessing dermoscopic images, both global and local features can be recognized. These features will be systematically described and illustrated in Part I of this article. First, we will focus on 8 morphologically rather distinctive global features that allow a quick, preliminary categorization of a given pigmented skin lesion. Second, we will describe various local features representing the letters of the dermoscopic alphabet. The local features permit a more detailed assessment of pigmented skin lesions.

  15. Photosynthetic pigments: perplexing persistent prevalence of 'superfluous' pigment production.

    PubMed

    Beale, Samuel I

    2008-04-22

    Phycobilins function as light-harvesting pigments in most cyanobacteria and red algae. Although green cyanobacteria of the genus Prochlorococcus express genes encoding enzymes that direct the synthesis of phycobilins, these pigments do not appear to play a role in light harvesting in Prochlorococcus. Now, it is shown that cyanophages infecting Prochlorococcus also contain genes for phycobilin-synthesizing enzymes, and these are expressed in Prochlorococcus, raising further questions as to the role of phycobilins in the host and the virus.

  16. Color stability of thermochromic pigment in maxillofacial silicone

    PubMed Central

    Lassila, Lippo V.J.; Tolvanen, Mimmi; Valittu, Pekka K.

    2013-01-01

    PURPOSE Maxillofacial silicone elastomer is usually colored intrinsically with color pigments to match skin colors. The purpose of this study was to investigate the color stability of a maxillofacial silicone elastomer, colored with a thermochromic, color changing pigment. MATERIALS AND METHODS Disc-shaped maxillofacial silicone specimens were prepared and divided into 3 groups: a conventionally colored control group, one group additionally colored with 0.2 wt% thermochromic pigment , and one group with 0.6 wt% thermochromic pigment. Half of the surface of each specimen was covered with an aluminium foil. All of the specimens were exposed to UV radiation in 6 hour cycles over 46 days. In between the UV exposures, half of the specimens were stored in darkness, at room temperature, and the other half was stored in an incubator, at a humidity of 97% and a temperature of +37℃. Color measurements were made with a spectrophotometer and registered according to the CIELAB L*a*b* color model system. The changes in L*, a* and b* values during artificial aging were statistically analyzed by using paired samples t-test and repeated measures ANOVA. P-values <.05 were considered as statistically significant. RESULTS The UV exposure resulted in visually noticeable and statistically significant color changes in the L*, a* and b* values in both of the test groups containing thermochromic pigment. Storage in the incubator lead to statistically significant color changes in the a* and b* values of the specimens containing thermochromic pigment, compared to those stored at room temperature. CONCLUSION The specimens containing thermochromic pigment were very sensitive to UV radiation, and the thermochromic pigment is not suitable, as such, to be used in maxillofacial prostheses. PMID:23755330

  17. Acquired, Idiopathic, Patterned Facial Pigmentation (AIPFP) Including Periorbital Pigmentation and Pigmentary Demarcation Lines on Face Follows the Lines of Blaschko on Face

    PubMed Central

    Sarma, Nilendu; Chakraborty, Sayantani; Bhattacharya, Sneha Ranjan

    2014-01-01

    Background: Acquired, non-nevoid, apparently idiopathic facial pigmentation are distributed over some specific locations like periorbital area, zygomatic area, malar area, root of nose, perioral and mandibular area. Periorbital pigmentation is the most well known entity in this group. These are bilaterally distributed homogenously diffuse gray to dark gray or slate-gray colored patches showing progressive intensification of pigmentation. These are often considered as physiologic or constitutional pigmentation. Some portions of the margins of these patches were described previously as pigmentary demarcation line (PDL- F, G, H). Aim: To analyze the distributional patterns of acquired, apparently idiopathic facial pigmentations and to evaluate the etiologic aspects of these conditions. Materials and Methods: Spatial patterns, distribution, and orientation were analyzed among 187 individuals with idiopathic non-nevoid, facial pigmentation. Observed patterns were compared with various pigmentary nevi and Blaschko's lines on face. Results: It was found that most of the idiopathic facial pigmentary alterations including periorbital pigmentation and PDL on face had specific patterned distribution that had high similarity to that of the pigmentary nevi and Blaschko's lines on face. Conclusion: It is hypothesized here that phenotypic expression of acquired patterned pigmentation (AIFPFP) is due to genetically determined increased pigmentary functional activity to various known and unknown yet natural factors like UV rays and aging. Mosaicism was a definite possibility. We also consider that the patterns actually reflected the normal patterns of embryological human pigmentation on face. PMID:24470659

  18. Measurement of macular pigment optical density in a healthy chinese population sample

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Macular pigment may protect against age-related macular degeneration (AMD) by its capability to absorb blue light and scavenge free radicals. Current information on human macular pigment density has been largely from studies on Caucasians populations. The purpose of this study was to assess macular ...

  19. Characterization of black pigment used in 30 BC fresco wall paint using instrumental methods and chemometry

    PubMed Central

    2012-01-01

    Background and methods Several standard powdered black pigments were characterized by means of thermogravimetry TG-DTG and allied techniques. These pigments were used to make standard plaster frescoes at this purpose prepared. The latter ones were subjected to Raman and reflectance analysis. The results obtained, together with TG data, were chemometrically processed and used to identify an analogous standard fresco fabricated by an unknown commercial black pigment, obtaining excellent results. Results The same colorimetric and reflectometric techniques, coupled with suitable chemometric techniques, were then successfully used to identify the type of black pigment present in an ancient roman fresco of the Imperial Age (30 B.C.). Conclusion TG-DTG resulted useful techniques to autenticate powdered black pigments.Colorimetry and Raman, but also the only colorimetry, were useful to identify an ancient black pigment in situ. PMID:22594437

  20. Loss of lysosomal membrane protein NCU-G1 in mice results in spontaneous liver fibrosis with accumulation of lipofuscin and iron in Kupffer cells

    PubMed Central

    Kong, Xiang Y.; Nesset, Cecilie Kasi; Damme, Markus; Løberg, Else-Marit; Lübke, Torben; Mæhlen, Jan; Andersson, Kristin B.; Lorenzo, Petra I.; Roos, Norbert; Thoresen, G. Hege; Rustan, Arild C.; Kase, Eili T.; Eskild, Winnie

    2014-01-01

    Human kidney predominant protein, NCU-G1, is a highly conserved protein with an unknown biological function. Initially described as a nuclear protein, it was later shown to be a bona fide lysosomal integral membrane protein. To gain insight into the physiological function of NCU-G1, mice with no detectable expression of this gene were created using a gene-trap strategy, and Ncu-g1gt/gt mice were successfully characterized. Lysosomal disorders are mainly caused by lack of or malfunctioning of proteins in the endosomal-lysosomal pathway. The clinical symptoms vary, but often include liver dysfunction. Persistent liver damage activates fibrogenesis and, if unremedied, eventually leads to liver fibrosis/cirrhosis and death. We demonstrate that the disruption of Ncu-g1 results in spontaneous liver fibrosis in mice as the predominant phenotype. Evidence for an increased rate of hepatic cell death, oxidative stress and active fibrogenesis were detected in Ncu-g1gt/gt liver. In addition to collagen deposition, microscopic examination of liver sections revealed accumulation of autofluorescent lipofuscin and iron in Ncu-g1gt/gt Kupffer cells. Because only a few transgenic mouse models have been identified with chronic liver injury and spontaneous liver fibrosis development, we propose that the Ncu-g1gt/gt mouse could be a valuable new tool in the development of novel treatments for the attenuation of fibrosis due to chronic liver damage. PMID:24487409

  1. Raman spectroscopic monitoring of the growth of pigmented and non-pigmented mycobacteria.

    PubMed

    Stöckel, Stephan; Stanca, Andrei Sebastian; Helbig, Jonathan; Rösch, Petra; Popp, Jürgen

    2015-11-01

    Raman microspectroscopy has increased in popularity in the field of microbiology because it allows a spectral fingerprinting of bacterial pathogens at an unrivaled speed, which is important for the early treatment of infectious diseases such as tuberculosis. An indispensable prerequisite for the success of this method is a profound knowledge, how the spectral profiles depend on the age of the bacteria. We therefore followed the growth of two rapidly growing Mycobacterium tuberculosis relatives, the pigmented Mycobacterium aurum, and the non-pigmented Mycobacterium smegmatis, by means of Raman microspectroscopy. Both species showed remarkable temporal changes in the single-bacteria Raman spectra: In the signatures of M. aurum, pigment-associated Raman signals could be detected not until 72 h of growth and also remained highly variable thereafter. The Raman spectra of M. smegmatis exhibited lipid signals presumably arising from mycolic acids, which are a hallmark feature of mycobacteria, but only after the bacteria reached the late stationary growth phase (>48 h). A principal component analysis thus classified the Raman spectra according to the cultivation age. In summary, these findings have to be reckoned with in future studies dealing with the identification of mycobacteria via Raman microspectroscopy. Graphical abstract Changes in the chemical composition of bacterial cells over growth time may influence the results of Raman spectroscopic studies of bacteria.

  2. Tryptophan in human hair: correlation with pigmentation.

    PubMed

    Bertazzo, A; Biasiolo, M; Costa, C V; Cardin de Stefani, E; Allegri, G

    2000-08-01

    The distribution of tryptophan content in human hair of various colours was evaluated, in order to study the accumulation of this amino acid, precursor of serotonin, melatonin and niacin, in hair and the influence on hair pigmentation. Pigmentation is an important factor in determining drug incorporation into hair. Results from 1211 samples of hair from healthy subjects (577 men and 634 women) show that tryptophan levels are significantly higher in males (37.83 +/- 3.45 microg/g dry hair) than in females (26.62 +/- 2.40 microg/g hair). Besides sex, age also influences the distribution of tryptophan in human hair, the highest levels being found in both sexes in the first few years of life, probably due to the influence of milk, and in aging subjects in the groups of 61-80 and > 80 years. In order to investigate the influence of hair colour, hair samples were subdivided according to colour into blond, dark blond, red, light brown, brown, black, grey and white. The hair contents of tryptophan in both sexes was higher in brown and black hair than in blond hair, but in grey and white hair concentrations were the highest, demonstrating that tryptophan accumulates among hair fibres with age. Grouping subjects by age in relation to hair colour, we observed that at ages 1-5 and 6-12 years, colour did not influence tryptophan contents, but at ages 13-19 and 20-40 years tryptophan content increased significantly from blond to brown at 13-19 years and from blond to black at 20-40 years in both sexes. Therefore, variations in tryptophan levels of human hair appear to be correlated with differences in hair colour in both sexes. Tryptophan also accumulates in hair during keratinization, as shown by the presence of high levels of this amino acid in grey and white hair.

  3. Aging

    PubMed Central

    Park, Dong Choon

    2013-01-01

    Aging is initiated based on genetic and environmental factors that operate from the time of birth of organisms. Aging induces physiological phenomena such as reduction of cell counts, deterioration of tissue proteins, tissue atrophy, a decrease of the metabolic rate, reduction of body fluids, and calcium metabolism abnormalities, with final progression onto pathological aging. Despite the efforts from many researchers, the progression and the mechanisms of aging are not clearly understood yet. Therefore, the authors would like to introduce several theories which have gained attentions among the published theories up to date; genetic program theory, wear-and-tear theory, telomere theory, endocrine theory, DNA damage hypothesis, error catastrophe theory, the rate of living theory, mitochondrial theory, and free radical theory. Although there have been many studies that have tried to prevent aging and prolong life, here we introduce a couple of theories which have been proven more or less; food, exercise, and diet restriction. PMID:24653904

  4. Age-related macular degeneration phenotypes are associated with increased tumor necrosis-alpha and subretinal immune cells in aged Cxcr5 knockout mice

    PubMed Central

    Huang, Hu; Liu, Ying; Wang, Lei; Li, Wen

    2017-01-01

    The role of chemokine receptor in age-related macular degeneration (AMD) remains elusive. The objective of this study is to investigate the role of chemokine receptor Cxcr5 in the pathogenesis of AMD. Cxcr5 gene expression levels (mRNA and protein) are higher in the retina and retinal pigment epithelium (RPE) of aged C57BL/6 wild type mice than younger ones. Vascular and glial cells express Cxcr5 and its ligand Cxcl13 in mouse retina. Aged Cxcr5 knockout (-/-) mice develop both early and late AMD-like pathological features. White and yellow spots, which look like drusen in humans, were identified with fundscopic examination. Drusen-like sub-RPE deposits with dome-shaped morphology were characterized on the sections. RPE vacuolization, swelling, and sub-RPE basal deposits were illustrated with light and transmission electron microscope (TEM). TEM further illustrated degenerated and disorganized RPE basal infoldings, phagosomes and melanosomes inside RPE, as well as abnormal photoreceptor outer segments. Lipofuscin granules and lipid droplets in the subretinal space, RPE, and choroid were revealed with fluorescence microscope and oil-red-O staining. Increased IgG in RPE/choroid were determined with Western blots (WB). WB and immunofluorescence staining determined RPE zona occuldens (ZO)-1 protein reduction and abnormal subcellular localization. TUNEL staining, outer nuclear layer (ONL) measurement and electroretinogram (ERG) recording indicated that photoreceptors underwent apoptosis, degeneration, and functional impairment. Additionally, spontaneous neovascularization (NV)-like lesions develop in the subretinal space of aged Cxcr5-/- mice. The underlying mechanisms are associated with increased subretinal F4/80+ immune cells, some of which contain RPE marker RPE65, and up-regulation of the multifunctional cytokine tumor necrosis factor-alpha (TNF-α) in RPE/choroid and retina. These findings suggest that Cxcr5 itself may be involved in the protection of RPE and

  5. Age-related macular degeneration phenotypes are associated with increased tumor necrosis-alpha and subretinal immune cells in aged Cxcr5 knockout mice.

    PubMed

    Huang, Hu; Liu, Ying; Wang, Lei; Li, Wen

    2017-01-01

    The role of chemokine receptor in age-related macular degeneration (AMD) remains elusive. The objective of this study is to investigate the role of chemokine receptor Cxcr5 in the pathogenesis of AMD. Cxcr5 gene expression levels (mRNA and protein) are higher in the retina and retinal pigment epithelium (RPE) of aged C57BL/6 wild type mice than younger ones. Vascular and glial cells express Cxcr5 and its ligand Cxcl13 in mouse retina. Aged Cxcr5 knockout (-/-) mice develop both early and late AMD-like pathological features. White and yellow spots, which look like drusen in humans, were identified with fundscopic examination. Drusen-like sub-RPE deposits with dome-shaped morphology were characterized on the sections. RPE vacuolization, swelling, and sub-RPE basal deposits were illustrated with light and transmission electron microscope (TEM). TEM further illustrated degenerated and disorganized RPE basal infoldings, phagosomes and melanosomes inside RPE, as well as abnormal photoreceptor outer segments. Lipofuscin granules and lipid droplets in the subretinal space, RPE, and choroid were revealed with fluorescence microscope and oil-red-O staining. Increased IgG in RPE/choroid were determined with Western blots (WB). WB and immunofluorescence staining determined RPE zona occuldens (ZO)-1 protein reduction and abnormal subcellular localization. TUNEL staining, outer nuclear layer (ONL) measurement and electroretinogram (ERG) recording indicated that photoreceptors underwent apoptosis, degeneration, and functional impairment. Additionally, spontaneous neovascularization (NV)-like lesions develop in the subretinal space of aged Cxcr5-/- mice. The underlying mechanisms are associated with increased subretinal F4/80+ immune cells, some of which contain RPE marker RPE65, and up-regulation of the multifunctional cytokine tumor necrosis factor-alpha (TNF-α) in RPE/choroid and retina. These findings suggest that Cxcr5 itself may be involved in the protection of RPE and

  6. [Radiolucent pigment gallstones (author's transl)].

    PubMed

    Wosiewitz, U; Wolpers, C; Quint, P

    1978-12-01

    Pigment gallstones may be subdivided into three different types: radiolucent and radioopaque stones in the gallbladder and radiolucent stones in the common bile duct. 35 of our patients had radiolucent pigment stones in the gallbladder; 21 of these were followed for years by repeated X-ray examination. There is only little enlargement of these stones as time passes by, however the number of these stones increases continuously. Chemical analysis could be done on such stones in 24 cases. The stones were composed of granular calcium bilirubinate and of asphalt-like products derived from abnormal bilirubin degradation. 5 patients had pigment stones in the common bile duct. These stones contained little cholesterol and exhibited a spongy microstructure characterized by small tubules with a diameter of 1 micrometer. They contained more lipids and bilirubin than the stones collected from the gallbladder and on extraction with organic solvents no asphalt-like residues could be obtained.

  7. 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.

  8. Correlation between tryptophan and hair pigmentation in human hair.

    PubMed

    Biasiolo, M; Bertazzo, A; Costa, C V; Allegri, G

    1999-01-01

    The concentration of tryptophan in human hair of various colours is determined in order to study their correlation with hair pigmentation. The mean levels of this amino acid in hair samples are higher in men than in women. Therefore, sex influences the content of tryptophan in human hair. In addition, age influences the distribution, the highest levels are observed in the 1-5 year age-group and in ageing subjects in the groups up to 61-80 years in both sexes. The hair samples subdivided, according the colour, into blond, dark blond, red, light brown, brown, black, grey, and white demonstrate that in both sexes the concentrations of tryptophan are higher in brown and black hair than in blond hair. However, the tryptophan levels are highest in grey and white hair, showing that tryptophan accumulates among hair fibres with age. Therefore, there is a correlation between tryptophan content and hair pigmentation.

  9. Idiopathic eruptive macular pigmentation with papillomatosis: Report of nine cases.

    PubMed

    Joshi, Rajiv

    2007-01-01

    Nine patients, seven males and two females aged 6-14 years, presented with extensive, asymptomatic, brown-black macules and mildly elevated, pigmented lesions of a few months' duration. The sites affected were the face, trunk and proximal extremities. The skin lesions were discrete and individual lesions were less than 2 cm in size. The clinical diagnoses rendered by the referring physicians were lichen planus pigmentosus, urticaria pigmentosa, erythema dyschromicum perstans and postinflammatory hyperpigmentation. Histology in all nine cases showed papillomatosis of the dermis with prominent pigmentation of the basal layer (pigmented papillomatosis) without any significant dermal inflammation. Two cases had spores of Pityrosporum ovale in the thickened horny layer, one of which also had, in addition, bacterial colonies in the stratum corneum. The pigmentation resolved on its own over several months. This presentation is similar to the previously described idiopathic eruptive macular pigmentation with the additional histological finding of papillomatosis that is being described for the first time and may be nosologically related to acanthosis nigricans and confluent and reticulate papillomatosis.

  10. 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.

  11. A case of pigmented Bowen's disease*

    PubMed Central

    Vivan, Márcia Maria; Hirata, Sérgio Henrique; do Nascimento, Liliane Santos; Enokihara, Milvia Maria Simões e Silva

    2017-01-01

    Pigmented Bowen's disease is a rare subtype of Bowen's disease. Clinically it presents as a slow-growing, well-defined, hyperpigmented plaque, and should be included as a differential diagnosis of other pigmented lesions. The authors describe a challenging case of pigmented Bowen's disease with non-diagnostic dermscopy findings. PMID:28225972

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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....

  19. 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...

  20. 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...

  1. 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...

  2. BACILLUS PYOCYANEUS AND ITS PIGMENTS

    PubMed Central

    Jordan, Edwin O.

    1899-01-01

    The principal conclusions that seem to me justified are as follows: 1. The fluorescent pigment formed by some varieties of B. pyocyaneus is produced under conditions identical with those governing the production of the pigment by other "fluorescent bacteria." 2. The production of pyocyanin is not dependent upon the presence of either phosphate or sulfate in the culture medium. It is formed in non-proteid as well as in proteid media, but is not a necessary accompaniment of the metabolic activities of the organism (e. g. tartrate solution). 3. The power of producing pyocyanin under conditions of artificial cultivation is lost sooner than the fluorescigenic power. 4. There are greater natural and acquired differences in pyocyanigenic power than in fluorescigenic. 5. The fluorescent pigment may be oxidized slowly by the action of light and air as well as by reagents into a yellow pigment, and pyocyanin may be similarly oxidized into a black pigment. 6. A convenient separation of B. pyocyaneus into four varieties would be the following: var. α, pyocyanigenic and fluorescigenic (most common); var. β, pyocyanigenic only (rare); var. γ, fluorescigenic only (not uncommon, closely related to "B. fluorescens liquefaciens"); var. δ, non-chromogenic. 7. Except for the occasional loss of one or another function the different varieties are not so plastic as sometimes assumed, and cannot be readily converted into one another by subjection to varying conditions of life. 8. The signification and correlation of the almost countless physiological variations among the members of this group in respect to growth in gelatin, behavior to temperature, indol production, etc., remain to be determined. It is not yet clear that the variations in chromogenic power can be in any way correlated with the presence or absence of other physiological functions. PMID:19866929

  3. Parainflammation associated with advanced glycation endproduct stimulation of RPE in vitro: implications for age-related degenerative diseases of the eye.

    PubMed

    Lin, Tony; Walker, Gregory Brett; Kurji, Khaliq; Fang, Edward; Law, Geoffrey; Prasad, Shiv S; Kojic, Luba; Cao, Sijia; White, Valerie; Cui, Jing Z; Matsubara, Joanne A

    2013-06-01

    Age related macular degeneration (AMD) is one of the leading causes of blindness in Western society. A hallmark of early stage AMD are drusen, extracellular deposits that accumulate in the outer retina. Advanced glycation endproducts (AGE) accumulate with aging and are linked to several age-related diseases such as Alzheimer's disease, osteoarthritis, atherosclerosis and AMD. AGE deposits are found in drusen and in Bruch's membrane of the eye and several studies have suggested its role in promoting oxidative stress, apoptosis and lipofuscin accumulation. Recently, complement activation and chronic inflammation have been implicated in the pathogenesis of AMD. While AGEs have been shown to promote inflammation in other diseases, whether it plays a similar role in AMD is not known. This study investigates the effects of AGE stimulation on pro- and anti-inflammatory pathways in primary culture of human retinal pigment epithelial cells (RPE). Differential gene expression studies revealed a total of 41 up- and 18 down-regulated RPE genes in response to AGE stimulation. These genes fell into three categories as assessed by gene set enrichment analysis (GSEA). The main categories were inflammation (interferon-induced, immune response) and proteasome degradation, followed by caspase signaling. Using suspension array technology, protein levels of secreted cytokines and growth factors were also examined. Anti-inflammatory cytokines including IL10, IL1ra and IL9 were all overexpressed. Pro-inflammatory cytokines including IL4, IL15 and IFN-γ were overexpressed, while other pro-inflammatory cytokines including IL8, MCP1, IP10 were underexpressed after AGE stimulation, suggesting a para-inflammation state of the RPE under these conditions. Levels of mRNA of chemokine, CXCL11, and viperin, RSAD2, were up-regulated and may play a role in driving the inflammatory response via the NF-kB and JAK-STAT pathways. CXCL11 was strongly immunoreactive and associated with drusen in the AMD

  4. Haematite pigmentation events and palaeomagnetic recording: implications from the Pilbara Print Stone, Western Australia

    NASA Astrophysics Data System (ADS)

    Abrajevitch, Alexandra; Pillans, Brad J.; Roberts, Andrew P.

    2014-11-01

    Haematite pigment is a common constituent of sedimentary rocks, but its contribution to the natural remanent magnetization of rocks is poorly understood. Here, we describe magnetic properties of two distinct pigment types that produce a characteristic decorative `print stone' found in the ˜2.5 Ga Mount McRae Shale Formation, Hamersley Province, Western Australia. Distinct magnetic remanence directions observed in the Print Stone can be correlated to each pigment type. By comparison with the Australian apparent polar wander path, the remanence carried by uniformly distributed pigment can be dated to ˜15-25 Ma, while two age options, the Mesoproterozoic (˜1.5 Ga) or the middle Carboniferous (˜320-310 Ma), are permissible for the remanence carried by the pigment responsible for the distinctive `newsprint' pattern. Magnetic properties and demagnetization characteristics of the different pigment types overlap significantly, and thus are not predictive of the dominant remanence carrier. Magnetic characteristics of the uniformly distributed pigment vary significantly on short spatial scales. Strong local control on pigment formation raises the possibility that a primary remanent magnetization may survive locally in pockets within sedimentary red bed formations.

  5. Availability and Utilization of Pigments from Microalgae.

    PubMed

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

    2016-10-02

    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.

  6. Production of germ-line chimeras in zebrafish by cell transplants from genetically pigmented to albino embryos.

    PubMed Central

    Lin, S; Long, W; Chen, J; Hopkins, N

    1992-01-01

    To determine whether embryonic cells transplanted from one zebrafish embryo to another can contribute to the germ line of the recipient, and to determine whether pigmentation can be used as a dominant visible marker to monitor cell transplants, we introduced cells from genetically pigmented (donor) embryos to albino recipients at midblastula stage. By 48 hr many of the resulting chimeras expressed dark pigment in their eyes and bodies, characteristics of donor but not albino embryos. By 4-6 weeks of age pigmentation was observed on the body of 23 of 70 chimeras. In contrast to fully pigmented wild-type fish, pigmentation in chimeras appeared within transverse bands running from dorsal to ventral. Pigmentation patterns differed from one fish to another and in almost every case were different on each side of a single fish. At 2-3 months of age chimeras were mated to albino fish to determine whether pigmented donor cells had contributed to the germ line. Of 28 chimeric fish that have yielded at least 50 offspring each, 5 have given rise to pigmented progeny at frequencies of 1-40%. The donor cells for some chimeras were derived from embryos that, in addition to being pigmented, were transgenic for a lacZ plasmid. Pigmented offspring of some germ-line chimeras inherited the transgene, confirming that they descended from transplanted donor cells. Our ability to make germ-line chimeras suggests that it is possible to introduce genetically engineered cells into zebrafish embryos and to identify the offspring of these cells by pigmentation at 2 days of age. Images PMID:1584786

  7. 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.

  8. Cutaneous metastatic pigmented breast carcinoma.

    PubMed

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

    2016-03-16

    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.

  9. Visual Pigments of Goldfish Cones

    PubMed Central

    Hárosi, Ferenc I.; MacNichol, Edward F.

    1974-01-01

    Freshly isolated retinal photoreceptors of goldfish were studied microspectrophotometrically. Absolute absorptance spectra obtained from dark-adapted cone outer segments reaffirm the existence of three spectrally distinct cone types with absorption maxima at 455 ± 3,530 ± 3, and 625 ± 5 nm. These types were found often recognizable by gross cellular morphology. Side-illuminated cone outer segments were dichroic. The measured dichroic ratio for the main absorption band of each type was 2–3:1. Rapidly bleached cells revealed spectral and dichroic transitions in regions near 400–410, 435–455, and 350–360 nm. These photoproducts decay about fivefold as fast as the intermediates in frog rods. The spectral maxima of photoproducts, combined with other evidence, indicate that retinene2 is the chromophore of all three cone pigments. The average specific optical density for goldfish cone outer segments was found to be 0.0124 ± 0.0015/µm. The spectra of the blue-, and green-absorbing cones appeared to match porphyropsin standards with half-band width Δν = 4,832 ± 100 cm–1. The red-absorbing spectrum was found narrower, having Δν = 3,625 ± 100 cm–1. The results are consistent with the notion that visual pigment concentration within the outer segments is about the same for frog rods and goldfish cones, but that the blue-, and green-absorbing pigments possess molar extinctions of 30,000 liter/mol cm. The red-absorbing pigment was found to have extinction of 40,000 liter/mol cm, assuming invariance of oscillator strength among the three cone spectra. PMID:4817352

  10. Nanoscience of an ancient pigment.

    PubMed

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

    2013-02-06

    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.

  11. Frequency of black pigment in livers and spleens of coal workers: correlation with pulmonary pathology and occupational information

    SciTech Connect

    LeFevre, M.E.; Green, F.H.Y.; Joel, D.D.; Laqueur, W.

    1982-01-01

    Histologic sections of liver and spleen from 99 retired coal workers and nine non-coal workers were obtained at autopsy and scored for black pigment. Pigment was minimal in the non-coal workers, with the exception of one person with silicosis. Moderate or heavy pigment was seen in 10.4 per cent of liver sections and 19.5 per cent of spleen sections from coal workers. The extrapulmonary pigment was not associated with any pathologic tissue response. Information on pulmonary pathology and occupational exposure to dust was available for most workers. Highly significant positive correlation was found between the severity of pnuemoconiosis and the black pigment score in both liver and spleen; the correlation between emphysema and pigment score was lower, but still significant for liver. Significant positive correlations were found between years spent underground, years of retirement, and age at death versus pigment scores. Significant negative correlation was found between smoking and pigment. The positive association of extrapulmonary pigment with age at death, years of underground mining, and severity of pneumoconiosis suggests that cumulative lifetime exposure to coal mine dust may be the most important factor in the release of dust into the general circulation.

  12. Frequency of black pigment in livers and spleens of coal workers: correlation with pulmonary pathology and occupational information

    SciTech Connect

    LeFevre, M.E.; Green, F.H.; Joel, D.D.; Laqueur, W.

    1982-12-01

    Histologic sections of liver and spleen from 99 retired coal workers and nine non-coal workers were obtained at autopsy and scored for black pigment. Pigment was minimal in the non-coal workers, with the exception of one person with silicosis. Moderate or heavy pigment was seen in 10.4 per cent of liver sections and 19.5 per cent of spleen sections from coal workers. The extrapulmonary pigment was not associated with any pathologic tissue response. Information on pulmonary pathology and occupational exposure to dust was available for most workers. Highly significant positive correlation was found between the severity of pneumoconiosis and the black pigment score in both liver and spleen; the correlation between emphysema and pigment score was lower, but still significant for liver. Significant positive correlations were found between years spent underground, years of retirement, and age at death versus pigment scores. Significant negative correlation was found between smoking and pigment. The positive association of extrapulmonary pigment with age at death, years of underground mining, and severity of pneumoconiosis suggests that cumulative lifetime exposure to coal mine dust may be the most important factor in the release of dust into the general circulation.

  13. Phytochemistry: structure of the blue cornflower pigment.

    PubMed

    Shiono, Masaaki; Matsugaki, Naohiro; Takeda, Kosaku

    2005-08-11

    The same anthocyanin pigment makes roses red but cornflowers blue, a phenomenon that has so far not been entirely explained. Here we describe the X-ray crystal structure of the cornflower pigment, which reveals that its blue colour arises from a complex of six molecules each of anthocyanin and flavone, with one ferric iron, one magnesium and two calcium ions. We believe that this tetrametal complex may represent a previously undiscovered type of supermolecular pigment.

  14. 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.

  15. 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.

  16. Dermatoscopic findings of pigmented purpuric dermatosis*

    PubMed Central

    Ozkaya, Dilek Biyik; Emiroglu, Nazan; Su, Ozlem; Cengiz, Fatma Pelin; Bahali, Anil Gulsel; Yildiz, Pelin; Demirkesen, Cuyan; Onsun, Nahide

    2016-01-01

    Background Pigmented purpuric dermatosis is a chronic skin disorder of unknown aetiology characterised by symmetrical petechial and pigmented macules, often confined to the lower limbs. The aetiology of pigmented purpuric dermatosis is unknown. Dermatoscopy is a non-invasive diagnostic technique that allows the visualisation of morphological features invisible to the naked eye; it combines a method that renders the corneal layer of the skin translucent with an optical system that magnifies the image projected onto the retina. Objectives The aim of this study is to investigate the dermatoscopic findings of pigmented purpuric dermatosis. Methods This study enrolled patients diagnosed histopathologically with pigmented purpuric dermatosis who had dermatoscopic records. We reviewed the dermatoscopic images of PPD patients who attended the outpatient clinic in the Istanbul Dermatovenereology Department at the Bezmialem Vakıf University Medical Faculty. Results Dermatoscopy showed: coppery-red pigmentation (97%, n = 31) in the background, a brown network (34%, n = 11), linear vessels (22%, n = 7), round to oval red dots, globules, and patches (69%, n = 22; 75%, n = 24; 34%, n = 11; respectively), brown globules (26%, n = 8) and dots (53%, n = 17), linear brown lines (22%, n = 7), and follicular openings (13%, n = 4). Conclusion To our knowledge, this is the first study to report the dermatoscopy of pigmented purpuric dermatosis. In our opinion, dermatoscopy can be useful in the diagnosis of pigmented purpuric dermatosis. PMID:27828629

  17. 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)

  18. Inherited complement regulatory protein deficiency predisposes to human disease in acute injury and chronic inflammatory statesthe examples of vascular damage in atypical hemolytic uremic syndrome and debris accumulation in age-related macular degeneration.

    PubMed

    Richards, Anna; Kavanagh, David; Atkinson, John P

    2007-01-01

    In this chapter, we examine the role of complement regulatory activity in atypical hemolytic uremic syndrome (aHUS) and age-related macular degeneration (AMD). These diseases are representative of two distinct types of complement-mediated injury, one being acute and self-limited, the other reflecting accumulation of chronic damage. Neither condition was previously thought to have a pathologic relationship to the immune system. However, alterations in complement regulatory protein genes have now been identified as major predisposing factors for the development of both diseases. In aHUS, heterozygous mutations leading to haploinsufficiency and function-altering polymorphisms in complement regulators have been identified, while in AMD, polymorphic haplotypes in complement genes are associated with development of disease. The basic premise is that a loss of function in a plasma or membrane inhibitor of the alternative complement pathway allows for excessive activation of complement on the endothelium of the kidney in aHUS and on retinal debris in AMD. These associations have much to teach us about the host's innate immune response to acute injury and to chronic debris deposition. We all experience cellular injury and, if we live long enough, will deposit debris in blood vessel walls (atherosclerosis leading to heart attacks and strokes), the brain (amyloid proteins leading to Alzheimer's disease), and retina (lipofuscin pigments leading to AMD). These are three common causes of morbidity and mortality in the developed world. The clinical, genetic, and immunopathologic understandings derived from the two examples of aHUS and AMD may illustrate what to anticipate in related conditions. They highlight how a powerful recognition and effector system, the alternative complement pathway, reacts to altered self. A response to acute injury or chronic debris accumulation must be appropriately balanced. In either case, too much activation or too little regulation promotes

  19. 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.

  20. Organic pigments in plastics can cause allergic contact dermatitis.

    PubMed

    Jolanki, R; Kanerva, L; Estlander, T

    1987-01-01

    A short review on organic pigments in plastics as a cause of allergic contact dermatitis is presented. Previously, organic pigments have been reported as provoking allergic pigmented contact dermatitis when used in cosmetics. Here we present the case of a patient who developed allergic contact dermatitis from an organic pigment (Irgalite Orange F2G) in a plastic glove. This shows that organic pigments in plastics can also cause allergic contact dermatitis. The potential sensitizing capacity of organic pigments should be noted.

  1. Intrachoroidal Neovascularization in Transgenic Mice Overexpressing Vascular Endothelial Growth Factor in the Retinal Pigment Epithelium

    PubMed Central

    Schwesinger, Catherine; Yee, Charles; Rohan, Richard M.; Joussen, Antonia M.; Fernandez, Antonio; Meyer, Tobias N.; Poulaki, Vassiliki; Ma, Joseph J. K.; Redmond, T. Michael; Liu, Suyan; Adamis, Anthony P.; D’Amato, Robert J.

    2001-01-01

    Choroidal neovascularization in age-related macular degeneration is a frequent and poorly treatable cause of vision loss in elderly Caucasians. This choroidal neovascularization has been associated with the expression of vascular endothelial growth factor (VEGF). In current animal models choroidal neovascularization is induced by subretinal injection of growth factors or vectors encoding growth factors such as VEGF, or by disruption of the Bruch’s membrane/retinal pigment epithelium complex with laser treatment. We wished to establish a transgenic murine model of age-related macular degeneration, in which the overexpression of VEGF by the retinal pigment epithelium induces choroidal neovascularization. A construct consisting of a tissue-specific murine retinal pigment epithelium promoter (RPE65 promoter) coupled to murine VEGF164 cDNA with a rabbit β-globin-3′ UTR was introduced into the genome of albino mice. Transgene mRNA was expressed in the retinal pigment epithelium at all ages peaking at 4 months. The expression of VEGF protein was increased in both the retinal pigment epithelium and choroid. An increase of intravascular adherent leukocytes and vessel leakage was observed. Histopathology revealed intrachoroidal neovascularization that did not penetrate through an intact Bruch’s membrane. These results support the hypothesis that additional insults to the integrity of Bruch’s membrane are required to induce growth of choroidal vessels into the subretinal space as seen in age-related macular degeneration. This model may be useful to screen for inhibitors of choroidal vessel growth. PMID:11238064

  2. Anthocyanins. Plant pigments and beyond.

    PubMed

    Santos-Buelga, Celestino; Mateus, Nuno; De Freitas, Victor

    2014-07-23

    Anthocyanins are plant pigments widespread in nature. They play relevant roles in plant propagation and ecophysiology and plant defense mechanisms and are responsible for the color of fruits and vegetables. A large number of novel anthocyanin structures have been identified, including new families such as pyranoanthocyanins or anthocyanin oligomers; their biosynthesis pathways have been elucidated, and new plants with "a la carte" colors have been created by genetic engineering. Furthermore, evidence about their benefits in human health has accumulated, and processes of anthocyanin absorption and biotransformation in the human organism have started to be ascertained. These advances in anthocyanin research were revised in the Seventh International Workshop on Anthocyanins that took place in Porto (Portugal) on September 9-11, 2013. Some selected papers are collected in this special issue, where aspects such as anthocyanin accumulation in plants, relationship with color expression, stability in plants and food, and bioavailability or biological activity are revised.

  3. 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).

  4. Apolipoprotein E and its role in aging and survival.

    PubMed

    Bonomini, Francesca; Filippini, Francesca; Hayek, Tony; Aviram, Michael; Keidar, Shlomo; Rodella, Luigi F; Coleman, Raymond; Rezzani, Rita

    2010-02-01

    The study of biological aging has seen spectacular progress in the last decade and markers are increasingly employed for understanding physiological processes that change with age. Recently, it has been demonstrated that apolipoprotein E (apoE) has a major impact on longevity, but its mechanisms are still not fully understood. ApoE-deficient (E(o)) mice have proved to be a very popular model for studying spontaneous hypercholesterolemia and the subsequent development of atherosclerotic lesions, but only limited data are available with regard to aging and aging changes. We used this murine model to better characterize the involvement of apoE in aging and to evaluate its role in the maintenance of normal organ morphology. Our results show that E(0) mice at different ages (6, 12, 20 weeks old) developed age-dependent morphological and biochemical alterations, including fibrosis (newly formed collagen), pro-inflammatory cytokine (IL-6 and iNOS), lipofuscin accumulation, and decrease of antioxidant enzymes (superoxide dismutase and catalase) in several organs (kidney, liver and heart). It is significant that the observed degenerative findings in E(0) mice at different ages (6, 12, 20 weeks old) were not identified in control mice (C57BL), at 6, 12 and 20 weeks of age. Consequently, since these mice showed enzymatic and structural alterations, normally linked to the age, such as increase of lipofuscin, pro-inflammatory cytokines and decrease of antioxidant enzymes, we can conclude that apoE is a useful player in studies of longevity and age-related diseases, such as inflammatory status and atherosclerosis that are known risk factors for functional decline and early mortality. Moreover, it is possible that apoE may also play a role in other pathological conditions including, for example, cancer, rheumatoid arthritis and macular degeneration.

  5. Occurrence and formation kinetics of pyranomalvidin-procyanidin dimer pigment in Merlot red wine: impact of acidity and oxygen concentrations.

    PubMed

    Pechamat, Laurent; Zeng, Liming; Jourdes, Michael; Ghidossi, Rémy; Teissedre, Pierre-Louis

    2014-02-19

    Once released from red grape skins, anthocyanins undergo various chemical reactions leading to the formation of more stable pigments such as pyranoanthocyanin, as well as other derivatives. Among these pigments, pyranoanthocyanins linked directly to flavanol dimers have been detected and identified in aged Port wine but not in dry red wine. These pigments are very important with regard to the wine color evolution since they are involved in wine color evolution and stabilization. During this investigation, the occurrence in dry red wine of two pyranomalvidin-procyanidin dimer has been established by low and high resolution HPLC-UV-MS analysis. Moreover, the impact of acidity and oxygen levels on their formation in red wine has been estimated. After four months of evolution, the results showed that, for the same pH, the quantity of this pigment was correlated with oxygen concentrations. Moreover, for the same quantity of oxygen, the concentration of this pigment was related to the acidity level.

  6. 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

  7. Macular pigment Raman detector for clinical applications

    PubMed Central

    Ermakov, Igor; Ermakova, Maia; Gellermann, Werner; Bernstein, Paul S.

    2011-01-01

    Clinical studies of carotenoid macular pigments (MP) have been limited by the lack of noninvasive, objective instruments. We introduce a novel noninvasive optical instrument, an MP Raman detector, for assessment of the carotenoid status of the human retina in vivo. The instrument uses resonant excitation of carotenoid molecules in the visible wavelength range, and quantitatively measures the highly specific Raman signals that originate from the single- and double-bond stretch vibrations of the π-conjugated carotenoid molecule’s carbon backbone. The instrument is a robust, compact device and suitable for routine measurements of MP concentrations in a clinical setting. We characterized and tested the instrument in clinical studies of human subjects to validate its function and to begin to establish its role as a possible screening test for macular pathologies. We also show that the MP Raman spectroscopy technology has potential as a novel, highly specific method for rapid screening of carotenoid antioxidant levels in large populations at risk for vision loss from age-related macular degeneration, the leading cause of blindness of the elderly in the developed world. PMID:14715066

  8. 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

  9. 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

    2015-06-24

    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.

  10. Mitochondrial Turnover and Aging of Long-Lived Postmitotic Cells: The Mitochondrial–Lysosomal Axis Theory of Aging

    PubMed Central

    Kurz, Tino; Navratil, Marian; Arriaga, Edgar A.; Brunk, Ulf T.

    2010-01-01

    Abstract It is now generally accepted that aging and eventual death of multicellular organisms is to a large extent related to macromolecular damage by mitochondrially produced reactive oxygen species, mostly affecting long-lived postmitotic cells, such as neurons and cardiac myocytes. These cells are rarely or not at all replaced during life and can be as old as the whole organism. The inherent inability of autophagy and other cellular-degradation mechanisms to remove damaged structures completely results in the progressive accumulation of garbage, including cytosolic protein aggregates, defective mitochondria, and lipofuscin, an intralysosomal indigestible material. In this review, we stress the importance of crosstalk between mitochondria and lysosomes in aging. The slow accumulation of lipofuscin within lysosomes seems to depress autophagy, resulting in reduced turnover of effective mitochondria. The latter not only are functionally deficient but also produce increased amounts of reactive oxygen species, prompting lipofuscinogenesis. Moreover, defective and enlarged mitochondria are poorly autophagocytosed and constitute a growing population of badly functioning organelles that do not fuse and exchange their contents with normal mitochondria. The progress of these changes seems to result in enhanced oxidative stress, decreased ATP production, and collapse of the cellular catabolic machinery, which eventually is incompatible with survival. Antioxid. Redox Signal. 12, 503–535. PMID:19650712

  11. Diagnosis and management of facial pigmented macules.

    PubMed

    Lallas, Aimilios; Argenziano, Giuseppe; Moscarella, Elvira; Longo, Caterina; Simonetti, Vito; Zalaudek, Iris

    2014-01-01

    The differential diagnosis of pigmented macules on the mottled chronic sun-damaged skin of the face is challenging and includes lentigo maligna (LM), pigmented actinic (solar) keratosis, solar lentigo, and lichen-planus-like keratosis. Although dermatoscopy improves the diagnostic accuracy of the unaided eye, the accurate diagnosis and management of pigmented facial macules remains one of the most challenging scenarios in daily practice. This is related to the fact that pigmented actinic (solar) keratosis, lichen-planus-like keratosis, and LM may reveal overlapping criteria, making their differential diagnosis clinically difficult. For this reason, practical rules have been introduced, which should help to minimize the risk for inappropriate diagnosis and management of LM.

  12. 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.

  13. Color characterization of coatings with diffraction pigments.

    PubMed

    Ferrero, A; Bernad, B; Campos, J; Perales, E; Velázquez, J L; Martínez-Verdú, F M

    2016-10-01

    Coatings with diffraction pigments present high iridescence, which needs to be characterized in order to describe their appearance. The spectral bidirectional reflectance distribution functions (BRDFs) of six coatings with SpectraFlair diffraction pigments were measured using the robot-arm-based goniospectrophotometer GEFE, designed and developed at CSIC. Principal component analysis has been applied to study the coatings of BRDF data. From data evaluation and based on theoretical considerations, we propose a relevant geometric factor to study the spectral reflectance and color gamut variation of coatings with diffraction pigments. At fixed values of this geometric factor, the spectral BRDF component due to diffraction is almost constant. Commercially available portable goniospectrophotometers, extensively used in several industries (automotive and others), should be provided with more aspecular measurement angles to characterize the complex reflectance of goniochromatic coatings based on diffraction pigments, but they would not require either more than one irradiation angle or additional out-of-plane geometries.

  14. Induction of Yellow Pigmentation in Serratia marcescens

    PubMed Central

    Trias, Joaquim; Viñas, Miquel; Guinea, Jesús; Lorén, José G.

    1988-01-01

    The appearance of yellow pigmentation in nonpigmented strains of Serratia sp. has been demonstrated to be due to the production of a muconic acid, 2-hydroxy-5-carboxymethylmuconic acid semialdehyde. The 3,4-dihydroxyphenylacetate 2,3-dioxygenase responsible for the synthesis of this muconic acid was induced in all strains tested. Another muconic acid, the β-cis-cis-carboxymuconic acid, could also be synthesized from 3,4-dihydroxybenzoate, but this product was not colored. Mutants that were unable to grow on tyrosine and produced yellow pigment were isolated from nonpigmented strains. These mutants had properties similar to those of the yellow-pigmented strains. The ability to produce pigment may be more widespread among Serratia marcescens strains than is currently known. PMID:16347803

  15. 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.

  16. Genetics of pigmentation and melanoma predisposition.

    PubMed

    Pho, L N; Leachman, S A

    2010-02-01

    About 5-10% of human cutaneous malignant melanoma is hereditary and known to involve rare germline mutations in highly penetrant, autosomal dominant genes. These genes are important in cell cycle control but are not responsible for all familial cases of melanoma. Epidemiologic studies have linked specific phenotypic traits including fair skin, light-colored eyes, and poor tanning ability to melanoma risks. The ability to visually discern and define pigmentary phenotypes in humans and in animal models has permitted elucidation of many genes involved in pigmentation and melanin biosynthesis. Additional genetic epidemiological studies have recently identified a subset of these pigmentation genes that are associated with risk for melanoma and other cutaneous malignancies as well as photosensitivity. Genome-wide association studies (GWAS) have unveiled single nucleotide polymorphisms (SNPs) or genetic variants in MC1R, TPCN2, ASIP, KITLG, NCKX5, TYR, IRF4, OCA2, and TYRP1 pigmentation genes. These findings emphasize the contribution of pigmentation pathways to melanoma predisposition and tumorigenesis through gene-environment interactions. Since pigmentation genes in the melanin synthesis pathway also confer risk for cutaneous malignancy, a better understanding of the operative molecular mechanisms involved in this relationship has the potential to impact individual risk assessment for cutaneous malignant melanoma in the future. This paper is an overview of our current understanding of pigmentation gene modifications that have been associated with melanoma risk and how these genes can enrich clinical management, prevention, and early detection of malignant melanoma.

  17. Microspectrophotometry of Arthropod Visual Screening Pigments

    PubMed Central

    Strother, G. K.; Casella, A. J.

    1972-01-01

    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

  18. Aging gauge

    DOEpatents

    Betts, Robert E.; Crawford, John F.

    1989-01-01

    An aging gauge comprising a container having a fixed or a variable sized t opening with a cap which can be opened to control the sublimation rate of a thermally sublimational material contained within the container. In use, the aging gauge is stored with an item to determine total heat the item is subjected to and also the maximum temperature to which the item has been exposed. The aging gauge container contains a thermally sublimational material such as naphthalene or similar material which has a low sublimation rate over the temperature range from about 70.degree. F. to about 160.degree. F. The aging products determined by analyses of a like item aged along with the aging gauge for which the sublimation amount is determined is employed to establish a calibration curve for future aging evaluation. The aging gauge is provided with a means for determining the maximum temperature exposure (i.e., a thermally indicating material which gives an irreversible color change, Thermocolor pigment). Because of the relationship of doubling reaction rates for increases of 10.degree. C., equivalency of item used in accelerated aging evaluation can be obtained by referring to a calibration curve depicting storage temperature on the abscissa scale and multiplier on the ordinate scale.

  19. Aging gauge

    DOEpatents

    Betts, Robert E.; Crawford, John F.

    1989-04-04

    An aging gauge comprising a container having a fixed or a variable sized t opening with a cap which can be opened to control the sublimation rate of a thermally sublimational material contained within the container. In use, the aging gauge is stored with an item to determine total heat the item is subjected to and also the maximum temperature to which the item has been exposed. The aging gauge container contains a thermally sublimational material such as naphthalene or similar material which has a low sublimation rate over the temperature range from about 70.degree. F. to about 160.degree. F. The aging products determined by analyses of a like item aged along with the aging gauge for which the sublimation amount is determined is employed to establish a calibration curve for future aging evaluation. The aging gauge is provided with a means for determining the maximum temperature exposure (i.e., a thermally indicating material which gives an irreversible color change, Thermocolor pigment). Because of the relationship of doubling reaction rates for increases of 10.degree. C., equivalency of item used in accelerated aging evaluation can be obtained by referring to a calibration curve depicting storage temperature on the abscissa scale and multiplier on the ordinate scale.

  20. Pseudocyanotic pigmentation of the skin induced by amiodarone: a light and electron microscopic study.

    PubMed Central

    Delage, C.; Lagacé, R.; Huard, J.

    1975-01-01

    An unusual bluish discolouration of the nose was noticed in a woman 9 months after she had begun treatment with a coronary vasodilator, amiodarone hydrochloride. Cutaneous biopsies of the nose were obtained 6 and 9 months later for light and electron microscopic studies. In the dermis were histiocytes containing cytoplasmic yellow-brown granules with histochemical properties of melanin and lipofuscin. Ultrastructurally the granules appeared as lysosomal membrane-bound dense bodies similar to lipofuscin. Similar granules were observed at diascopy in both corneas. The pathogenesis is obscure. A storage disease involving the drug or its metabolites cannot be ruled out. Another possibility is that amiodarone accelerates the normal cellular autophagocytosis, resulting in increased production of lipofuscin, which then accumulates in lysosomes because of a deficiency in lipolytic enzymes. Images FIG. 1 FIG. 2 FIG. 3 FIG. 4 FIG. 5 FIG. 6 FIG. 7 FIG. 8 PMID:47784

  1. Decrease in nicotinamide adenine dinucleotide dehydrogenase is related to skin pigmentation.

    PubMed

    Nakama, Mitsuo; Murakami, Yuhko; Tanaka, Hiroshi; Nakata, Satoru

    2012-03-01

    Skin pigmentation is caused by various physical and chemical factors. It might also be influenced by changes in the physiological function of skin with aging. Nicotinamide adenine dinucleotide (NADH) dehydrogenase is an enzyme related to the mitochondrial electron transport system and plays a key role in cellular energy production. It has been reported that the functional decrease in this system causes Parkinson's disease. Another study reports that the amount of NADH dehydrogenase in heart and skeletal muscle decreases with aging. A similar decrease in the skin would probably affect its physiological function. However, no reports have examined the age-related change in levels of NADH dehydrogenase in human skin. In this study, we investigated this change and its effect on skin pigmentation using cultured human epidermal keratinocytes. The mRNA expression of NDUFA1, NDUFB7, and NDUFS2, subunits of NADH dehydrogenase, and its activity were significantly decreased in late passage keratinocytes compared to early passage cells. Conversely, the mRNA expression of melanocyte-stimulating cytokines, interleukin-1 alpha and endothelin 1, was increased in late passage cells. On the other hand, the inhibition of NADH dehydrogenase upregulated the mRNA expression of melanocyte-stimulating cytokines. Moreover, the level of NDUFB7 mRNA was lower in pigmented than in nonpigmented regions of skin in vivo. These results suggest the decrease in NADH dehydrogenase with aging to be involved in skin pigmentation.

  2. The etiology and molecular genetics of human pigmentation disorders

    PubMed Central

    Baxter, Laura L.; Pavan, William J.

    2012-01-01

    Pigmentation, defined as the placement of pigment in skin, hair, and eyes for coloration, is distinctive because the location, amount, and type of pigmentation provides a visual manifestation of genetic heterogeneity in pathways regulating the pigment-producing cells, melanocytes. The scope of this genetic heterogeneity in humans ranges from normal to pathological pigmentation phenotypes. Clinically normal human pigmentation encompasses a variety of skin and hair color as well as with punctate pigmentation such as melanocytic nevi (moles) or ephelides (freckles), while clinically abnormal human pigmentation exhibits markedly reduced or increased pigment levels, known as hypopigmentation and hyperpigmentation, respectively. Elucidation of the molecular genetics underlying pigmentation has revealed genes important for melanocyte development and function. Furthermore, many pigmentation disorders show additional defects in cells other than melanocytes, and identification of the genetic insults in these disorders has revealed pleiotropic genes, where a single gene is required for various functions, often in different cell types. Thus unravelling the genetics of easily visualized pigmentation disorders has identified molecular similarities between melanocytes and less visible cell types/tissues, revealing a common cellular origin and/or common genetic regulatory pathways. Herein we discuss notable human pigmentation disorders and their associated genetic alterations, focusing on the fact that the developmental genetics of pigmentation abnormalities is instructive for understanding normal pathways governing development and function of melanocytes. PMID:23799582

  3. A simple route to synthesize mesoporous titania from TiOSO4: Influence of the synthesis conditions on the structural, pigments and photocatalytic properties

    NASA Astrophysics Data System (ADS)

    Yang, Guang; Ding, Hao; Chen, Daimei; Ao, Weihua; Wang, Jian; Hou, Xifeng

    2016-07-01

    The work obtained mesoporous TiO2 white pigments using titanyl sulfate as titanium source with a simple, low-temperature method simplifying the synthesis process and reducing the energy consumption. We investigated the effects of the aging temperature and aging time on the structure and pigments properties of the samples. The structure and morphology of mesoporous samples were characterized by X-ray diffraction and transmission electron microscopy. The obtained mesoporous TiO2 showed excellent pigments properties of whiteness (93.91%), hiding power (12.37 g m-2), and lightness value (97.89), respectively. Moreover, such materials showed outstanding photodegradation performance of organic dyes under UV light irradiation. The current research provided an alternative route to prepare mesoporous TiO2 micspheres white pigments with well photocatalytic performance for indoor purification on industrial scale. It has great significance in titania white pigments field.

  4. Pigmented eccrine poroma: dermoscopic and confocal features

    PubMed Central

    Bombonato, Caterina; Piana, Simonetta; Moscarella, Elvira; Lallas, Aimillios; Argenziano, Giuseppe; Longo, Caterina

    2016-01-01

    Eccrine poroma is a rare benign adnexal tumor of epithelial cells originating from the terminal ductal portion of the sweat glands that is typically located on palms and soles, although other cutaneous sites can be affected [1]. It is usually nonpigmented even if there is a pigmented variant that corresponds to 17% of cases and it is usually underdiagnosed, since it is mistakenly confused with other pigmented tumors [2,3]. Dermoscopy and reflectance confocal microscopy (RCM) may assist in the correct diagnosis of this tumor. Herein, we report one case of pigmented eccrine poroma (PEP) that simulated clinically a cutaneous melanoma or a basal cell carcinoma. Dermoscopy and RCM excluded the possibilities of those two diagnoses; the overall confocal findings were suggestive for a benign epithelial tumor. Histology was fundamental to diagnose this lesion as a pigmented eccrine poroma. Even if the diagnosis of eccrine poroma remains histopathological still, as in this case report, noninvasive tools such as dermoscopy and RCM examinations can be of help to rule out the diagnosis of melanoma. Larger studies on this rare pigmented variant of eccrine poroma could shed new light on the identification of specific diagnostic dermoscopic and confocal features. PMID:27648386

  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. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Interactions between inorganic pigments and proteinaceous binders in reference paint reconstructions.

    PubMed

    Duce, Celia; Bramanti, Emilia; Ghezzi, Lisa; Bernazzani, Luca; Bonaduce, Ilaria; Colombini, Maria Perla; Spepi, Alessio; Biagi, Simona; Tine, Maria Rosaria

    2013-05-07

    The degradation of the proteinaceous binders, ovalbumin (OVA) and casein, and their interactions with azurite (Cu(3)(CO(3))(2)(OH)(2)), calcium carbonate (CaCO(3)), hematite (Fe(2)O(3)) and red lead (Pb(3)O(4)) pigments were studied. A multi-analytical approach based on Thermogravimetric Analysis (TG), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and Size Exclusion Chromatography (SEC) was used. The research was carried out on a set of paint reconstructions, which were analysed before and after artificial light ageing. We highlighted that in most cases the inorganic pigments interact with both proteins by decreasing their thermal stability and their intermolecular β-sheet content, and that ageing induces aggregation. We hypothesized that pigments intercalate between protein molecules, producing a partial disruption to the protein-protein intermolecular interaction. In the case of casein, these phenomena continued during ageing. In fact, we observed a complete disappearance of intermolecular β-sheets and an increase in intramolecular β-sheets and random coil during ageing. This result is in agreement with the structural properties of casein, whose aggregation is known to be induced by hydrophobic interactions. On the other hand, in aged OVA paint replicas, we observed the formation of new intermolecular β-sheets and an increase in thermostability. In addition FTIR showed oxidation of the side chains of the aged OVA/hematite sample and aged casein pigment samples, and SEC highlighted hydrolysis phenomena in aged carbonate, azurite and red lead/OVA complexes and in aged casein/calcium carbonate and casein/azurite samples.

  11. Pretreatment of pigments to prepare liquids for enteric coating.

    PubMed

    Bölcskei, E; Bajdik, J; Müller, J; Knop, K; Kleinebudde, P; Pintye-Hódi, K

    2008-07-01

    Film coating fluids commonly contain different pigments. The objective of this work was a study of the distribution of these particles in the coating film. Different pretreatment forms (pigment suspension, pigment paste and untreated pigments) were applied. They were incorporated into a Eudragit L 30 D-55 dispersion. The surface roughness and the mechanical properties of the free films indicated, that the most homogeneous film was obtained with the pigment paste. The homogeneity of the film was investigated by mechanical testing. The protective effect of the coating did not vary with the application of pigments in different forms, but the appearance of the coated tablets underwent a considerable change.

  12. Aspects of the digestive gland cells of the mussel Mytilus galloprovincialis, in relation to lysosomal enzymes, lipofuscin presence and shell size: contribution in the assessment of marine pollution biomarkers.

    PubMed

    Raftopoulou, E K; Dimitriadis, V K

    2012-02-01

    The present study investigates the histochemical localization of N-acetyl-β-hexozaminidase (Hex), acid phosphatase (AcP) and β-glucuronidase (β-Gus) in the digestive gland of mussels Mytilus galloprovincialis, as well as the clarification of suitable enzyme for biomarkers' application dealing with lysosomes. The results show more intense and homogenous localization of Hex, in relation to AcP and β-Gus and, thus, Hex histochemistry is supported as more suitable procedure for the evaluation of "lysosomal membrane stability" and "morphometrical alterations of lysosomes". The affection of lipofuscin granules on lysosomal enzymes' activity is also discussed. Additionally, the present study examines the response of small- and large-sized mussels M. galloprovincialis by assessing the "lysosomal membrane stability", "morphometrical alterations of lysosomes", "lysosomal response index (LRI)" and "structural epithelial changes in digestive tubules". The results indicate appreciable alterations of the above parameters in large-sized mussels, supporting their greater influence by the environmental factors, in relation to small-sized ones.

  13. Detection of Pigment Networks in Dermoscopy Images

    NASA Astrophysics Data System (ADS)

    Eltayef, Khalid; Li, Yongmin; Liu, Xiaohui

    2017-02-01

    One of the most important structures in dermoscopy images is the pigment network, which is also one of the most challenging and fundamental task for dermatologists in early detection of melanoma. This paper presents an automatic system to detect pigment network from dermoscopy images. The design of the proposed algorithm consists of four stages. First, a pre-processing algorithm is carried out in order to remove the noise and improve the quality of the image. Second, a bank of directional filters and morphological connected component analysis are applied to detect the pigment networks. Third, features are extracted from the detected image, which can be used in the subsequent stage. Fourth, the classification process is performed by applying feed-forward neural network, in order to classify the region as either normal or abnormal skin. The method was tested on a dataset of 200 dermoscopy images from Hospital Pedro Hispano (Matosinhos), and better results were produced compared to previous studies.

  14. Predicting Phenotype from Genotype: Normal Pigmentation*

    PubMed Central

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

    2013-01-01

    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

  15. 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.

  16. 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.

  17. An intracellular anion channel critical for pigmentation.

    PubMed

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

    2014-12-16

    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.

  18. Management of pigmented gingiva in child patient: a new era to the pediatric dentistry.

    PubMed

    Namdeoraoji Bahadure, Rakesh; Singh, Parul; Jain, Eesha; Khurana, Heena; Badole, Gautam

    2013-09-01

    Gingival health in the form of size, shape, consistency and appearance are essential components responsible for an attractive smile as well as may cause unpleasant appearance. Melanin pigmentation often occurs in the gingiva as a result of an abnormal deposition of melanin which can compromise the confidence level from the age of childhood. The present article describes and discusses the two cases of gingival melanin pigmentation in 12 and 13 years of female patient and their early surgical intervention with successful follow-up of 9 and 6 months. Patients were instructed to prevent sun exposure, intake of hot foods or beverages like cold drinks, tea, coffee and brushing immediately after surgery. How to cite this article: Bahadure RN, Singh P, Jain E, Khurana H, Badole G. Management of Pigmented Gingiva in Child Patient: A New Era to the Pediatric Dentistry. Int J Clin Pediatr Dent 2013;6(3):197-200.

  19. Management of Pigmented Gingiva in Child Patient: A New Era to the Pediatric Dentistry

    PubMed Central

    Singh, Parul; Jain, Eesha; Khurana, Heena; Badole, Gautam

    2013-01-01

    ABSTRACT Gingival health in the form of size, shape, consistency and appearance are essential components responsible for an attractive smile as well as may cause unpleasant appearance. Melanin pigmentation often occurs in the gingiva as a result of an abnormal deposition of melanin which can compromise the confidence level from the age of childhood. The present article describes and discusses the two cases of gingival melanin pigmentation in 12 and 13 years of female patient and their early surgical intervention with successful follow-up of 9 and 6 months. Patients were instructed to prevent sun exposure, intake of hot foods or beverages like cold drinks, tea, coffee and brushing immediately after surgery. How to cite this article: Bahadure RN, Singh P, Jain E, Khurana H, Badole G. Management of Pigmented Gingiva in Child Patient: A New Era to the Pediatric Dentistry. Int J Clin Pediatr Dent 2013;6(3):197-200. PMID:25206222

  20. Generation of retinal pigment epithelial cells from human embryonic stem cell-derived spherical neural masses.

    PubMed

    Cho, Myung Soo; Kim, Sang Jin; Ku, Seung-Yup; Park, Jung Hyun; Lee, Haksup; Yoo, Dae Hoon; Park, Un Chul; Song, Seul Ae; Choi, Young Min; Yu, Hyeong Gon

    2012-09-01

    Dysfunction and loss of retinal pigment epithelium (RPE) are major pathologic changes observed in various retinal degenerative diseases such as aged-related macular degeneration. RPE generated from human pluripotent stem cells can be a good candidate for RPE replacement therapy. Here, we show the differentiation of human embryonic stem cells (hESCs) toward RPE with the generation of spherical neural masses (SNMs), which are pure masses of hESCs-derived neural precursors. During the early passaging of SNMs, cystic structures arising from opened neural tube-like structures showed pigmented epithelial morphology. These pigmented cells were differentiated into functional RPE by neuroectodermal induction and mechanical purification. Most of the differentiated cells showed typical RPE morphologies, such as a polygonal-shaped epithelial monolayer, and transmission electron microscopy revealed apical microvilli, pigment granules, and tight junctions. These cells also expressed molecular markers of RPE, including Mitf, ZO-1, RPE65, CRALBP, and bestrophin. The generated RPE also showed phagocytosis of isolated bovine photoreceptor outer segment and secreting pigment epithelium-derived factor and vascular endothelial growth factor. Functional RPE could be generated from SNM in our method. Because SNMs have several advantages, including the capability of expansion for long periods without loss of differentiation capability, easy storage and thawing, and no need for feeder cells, our method for RPE differentiation may be used as an efficient strategy for generating functional RPE cells for retinal regeneration therapy.

  1. 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.

  2. The focal differentiation of pigment cells.

    PubMed

    Whimster, I W

    1979-05-01

    A study has been made of the normal development and of the regeneration after excision of the groups of large pigment cells which form the spotted skin pattern of the gecko Eublepharis macularius, together with the effects of neonatal graft transplantation on this pattern. The results all indicate strongly that such groups of specialized pigment cells are not clones but the product of an induction process. This is then compared with the neural reflex mechanism by which the skin pattern of Chamaeoleo dilepis is formed.

  3. RISK ASSESSMENT FOR THE DYE AND PIGMENT ...

    EPA Pesticide Factsheets

    This risk assessment calculates the maximum loadings of constituents found in dyes and pigment industries waste streams which can be disposed in different types of waste management units without causing health benchmarks to be exceeded at plausible receptor locations. The assessment focuses on potential risks from volatilization and leaching to groundwater of constituents disposed in surface impoundments and landfills with either clay liners or composite liners. This product will be used by EPA decision makers to assist in determining whether certain waste streams generated by the dyes and pigments industries should be designated as hazardous.

  4. Locally differentiated cryptic pigmentation in the freshwater isopod Asellus aquaticus.

    PubMed

    Hargeby, A; Stoltz, J; Johansson, J

    2005-05-01

    A repeated pattern of background colour matching in animals is an indication that pigmentation may be cryptic. Here, we examine the relationship between pigmentation of the freshwater isopod Asellus aquaticus and background darkness in 29 lakes, wetlands and ponds in Southern Sweden. The results show that Asellus pigmentation was correlated with substrate darkness across all localities. In seven localities, in which two contrasting substrate types were noted, Asellus populations were differentiated with respect to pigmentation. These findings thus provide phenomenological support for cryptic pigmentation in Asellus. Pigmentation generally increased with body size, but the relationship between pigmentation and size differed among localities, possibly as a result of differences in correlational selection on pigmentation and size. Selection thus appears to have resulted in local differentiation over a small spatial scale, even within lakes and wetlands. This differentiation is a likely cause behind elevated phenotype variation noted in localities with two substrate types, suggesting that habitat heterogeneity promotes genetic diversity.

  5. 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)

  6. Pigmented poroma with unusual location and dermatoscopic features

    PubMed Central

    Kassuga, Luiza E. B. P.; Jeunon, Thiago; Sousa, Maria Auxiliadora Jeunon; Campos-do-Carmo, Gabriella

    2012-01-01

    Poroma is a benign adnexal neoplasm with atn “poroid”/ductal differentiation that mimics benign and malignant skin tumors. Histopathology shows circumscribed proliferation of poroid cells intermingled with a variable number of cuticular cells. We report a case of pigmented poroma located on the face that simulated clinically and dermatoscopically a pigmented basal cell carcinoma. The features of pigmented and non-pigmented poromas were revisited in order to assist in the diagnosis. PMID:23785609

  7. 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.

  8. Prostaglandin-induced iridial pigmentation in primates.

    PubMed

    Selén, G; Stjernschantz, J; Resul, B

    1997-02-01

    Latanoprost, a new ocular hypotensive prostaglandin F2 alpha analogue prodrug, was found to induce increased pigmentation of monkey irides in chronic toxicity studies. This prompted us to investigate the effect of naturally occurring prostaglandins on the monkey iris to determine whether this pigmentary effect is unique for latanoprost or whether it is a class effect of prostaglandins. PGF2 alpha-isopropyl ester (IE), PGE2-IE and latanoprost were applied topically to cynomolgus monkey eyes for 18-44 weeks. One eye of each animal was treated, while the other served as control. In addition, latanoprost was applied to sympathectomized monkey eyes. PGF2 alpha-IE, PGE2-IE, as well as latanoprost, induced increased pigmentation in the monkey eye. The first signs of this effect were seen after about two months of treatment. Latanoprost also induced increased pigmentation in sympathectomized eyes. It is concluded that both naturally occurring prostaglandins and their synthetic analogues can induce increased iridial pigmentation in cynomolgus monkeys, and that the effect does not require the presence of sympathetic nerves.

  9. 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

  10. 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

  11. BRIEF COMMUNICATIONS: Picosecond spectroscopy of pyrrol pigments

    NASA Astrophysics Data System (ADS)

    Lippitsch, M. E.; Leitner, A.; Riegler, M.; Aussenegg, F. R.

    1982-05-01

    Picosecond fluorescence and absorption spectroscopy methods were used to study pyrromethenone, pyrromethene, and biliverdin. These methods made it possible to determine some details of the kinetics of various relaxation mechanisms. The results obtained provided a better understanding of the biological action of pyrrol pigments.

  12. The 503nm pigment of Escherichia coli

    PubMed Central

    Kamitakahara, Joyce R.; Polglase, W. J.

    1970-01-01

    The yield of cell protein was one-third less for streptomycin-dependent Escherichia coli B than for the wild-type parent strain when both were grown aerobically on a medium with limiting glucose, but anaerobically the yield of protein was similar for both strains. The transient pigment absorbing at 503nm that is known to be present in E. coli and other organisms was not detectable in streptomycin-dependent mutants nor in a non-dependent (energy-deficient) revertant. When wild-type E. coli B was grown on limiting glucose–salts medium containing 2,4 dinitrophenol, the yield of cell protein was decreased and formation of the 503nm pigment was inhibited. Fumarase, aconitase and glucose 6-phosphate dehydrogenase were de-repressed in E. coli B cells grown with excess of glucose in a medium containing 2,4-dinitrophenol. In air-oxidized, wild-type E. coli B cells, the 503nm pigment appeared before reduced cytochromes when gluconate was the substrate but failed to appear when succinate was the substrate. The results provide evidence for a role of the 503nm pigment in aerobic energy metabolism, possibly as an electron acceptor from NADPH. PMID:4395501

  13. "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.

  14. Pigment patterns in adult fish result from superimposition of two largely independent pigmentation mechanisms.

    PubMed

    Ceinos, Rosa M; Guillot, Raúl; Kelsh, Robert N; Cerdá-Reverter, José M; Rotllant, Josep

    2015-03-01

    Dorso-ventral pigment pattern differences are the most widespread pigmentary adaptations in vertebrates. In mammals, this pattern is controlled by regulating melanin chemistry in melanocytes using a protein, agouti-signalling peptide (ASIP). In fish, studies of pigment patterning have focused on stripe formation, identifying a core striping mechanism dependent upon interactions between different pigment cell types. In contrast, mechanisms driving the dorso-ventral countershading pattern have been overlooked. Here, we demonstrate that, in fact, zebrafish utilize two distinct adult pigment patterning mechanisms - an ancient dorso-ventral patterning mechanism, and a more recent striping mechanism based on cell-cell interactions; remarkably, the dorso-ventral patterning mechanism also utilizes ASIP. These two mechanisms function largely independently, with resultant patterns superimposed to give the full pattern.

  15. Rethinking the History of Artists' Pigments Through Chemical Analysis

    NASA Astrophysics Data System (ADS)

    Berrie, Barbara H.

    2012-07-01

    Following a brief overview of the history of analysis of artists' pigments, I discuss the illustrative example of lead-tin yellow. Recent advances in our knowledge of artists' use of red lakes, glassy pigments, and metallic pigments in works of cultural heritage, particularly European paintings, as determined from chemical analyses are described.

  16. 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.

  17. Origin of adult-type pigment cells forming the asymmetric pigment pattern, in Japanese flounder (Paralichthys olivaceus).

    PubMed

    Yamada, Toshiyuki; Okauchi, Masanori; Araki, Kazuo

    2010-12-01

    The flatfish-specific asymmetric pigment pattern depends on the asymmetric appearance of adult-type pigment cells after the late metamorphic stages. To understand the mechanism enabling the formation of this asymmetric pattern, we investigated the behavior of pigment cell latent precursors in postembryonic Japanese flounder, Paralichthys olivaceus, by analysis of the expression patterns of pigment lineage markers (colony stimulating factor 1 receptor, dopachrome tautomerase, kit) and the DiI (DiO) labeling test for latent precursors. We found that, throughout the larval stages, pigment cell latent precursors were predominantly localized along the dorsal and ventral margins of the flank symmetrically and migrated continuously from these regions to the lateral sides symmetrically, and after late metamorphic stages these precursors differentiated into adult-type pigment cells on the lateral side asymmetrically. We conclude that adult-type pigment cells that form the asymmetric pigment pattern are continuously derived from the dorsal and ventral margins of the flank during larval development.

  18. Dimerization of visual pigments in vivo

    PubMed Central

    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

    2016-01-01

    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

  19. Macular pigment optical density in a South Indian population.

    PubMed

    Raman, Rajiv; Rajan, Rajni; Biswas, Sayantan; Vaitheeswaran, Kulothungan; Sharma, Tarun

    2011-10-07

    PURPOSE. To estimate the normal value of macular pigment optical density (MPOD) in an adult south Indian sample. METHODS. Three hundred eyes of 161 healthy volunteers (30 men and 30 women in each of the age groups of 20-29, 30-39, 40-49, 50-59, and ≥60 years) underwent MPOD measurement with a macular densitometer. Thirty-two eyes were also checked for intersession variability. RESULTS. The mean MPODs in the Indian sample were 0.64 ± 0.23 log unit at 0.25° eccentricity, 0.50 ± 0.21 log unit at 0.5°, 0.37 ± 0.19 log unit at 1.00°, and 0.21 ± 0.16 log unit at 1.75°. At all the foveal eccentricities, the MPOD showed an increase from 20 to 29 to 30 to 39 years of age and thereby showed a decrease with age. The men aged 40 to 49 years had significantly higher MPOD than did the women (0.75 vs. 0.62 log unit, P = 0.039), and the women aged 50 to 59 years had higher MPOD than did the men (0.71 vs. 0.57 log unit, P = 0.019). There was no significant intersession or interocular variation. CONCLUSIONS. This study establishes the MPOD normogram in an adult Indian sample.

  20. Central posterior capsule pigmentation in a patient with pigment dispersion and previous ocular trauma: a case report.

    PubMed

    Al-Mezaine, Hani S

    2010-01-01

    We report a 55-year-old man with unusually dense, unilateral central posterior capsule pigmentation associated with the characteristic clinical features of pigment dispersion syndrome, including a Krukenberg's spindle and dense trabecular pigmentation in both eyes. A history of an old blunt ocular trauma probably caused separation of the anterior hyaloid from the back of the lens, thereby creating an avenue by which pigment could reach the potential space of Berger's from the posterior chamber.

  1. 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

  2. Challenges of identifying eczema in darkly pigmented skin.

    PubMed

    Myers, Joan

    2015-07-01

    There is a paucity of information about the difference in the presentation of eczema in darkly pigmented skin compared to children with fair or white skin. This article describes the possible challenges of diagnosing eczema in children with darkly pigmented skin. The physiological difference in darkly pigmented skin compared with fair or white skin is explored, and how eczema may be manifested and identified in darkly pigmented skin. The author uses the term darkly pigmented skin to describe children of black Caribbean, African or Asian descent.

  3. Mapping of Photosynthetic Pigments in Spanish Reservoirs

    NASA Astrophysics Data System (ADS)

    Peña-Martinez, R.; Domínguez-Gómez, J.-A.; de Hoyos, C.; Ruiz-Verdú, A.

    2004-05-01

    We present the preliminary results of the first stage of the project AO-594, which comprises the development and calibration of algorithms for photosynthetic pigment mapping in Spanish reservoirs. In the years 2001-2002, an extensive field campaign was made in 36 reservoirs and lakes in order to obtain a database of Rrs spectra (400-1000 nm), photosynthetic pigments concentration and phytoplankton composition. The sampled water bodies cover a wide range of environmental conditions, trophic levels and phytoplankton communities. As a first approach in algorithm development, we have explored the relationships between ratios of MERIS bands and pigment concentrations through simple linear regression analysis. The bands have been selected based on the spectral properties of each pigment and a peak analysis of the Rrs spectra. For chlorophyll a, we have found a very good linear relationship (R2 =0.919) using the ratio between bands 9 and 7. Similar results are found using band 8 instead of 7. In any case, the model derived for the whole range of concentrations (0-500 mg m3 ) fails for low values (<15 mg m-3 ). Possible solutions include the use of - non-linear models or the use of two different models depending on the ratio values. For cyanobacteria detection, the ratio between bands 9 and 6 (the later centred at 620 nm) shows a good correlation (R2 =0.723) with phycocyanin concentration measured fluorometrically, and better (R2 =0.945) with zeaxanthin measured using HPLC. The correlation of other indicator pigments with MERIS band ratios is less strong, but is still possible to develop algorithms accurate enough for bloom monitoring. We also discuss the problems found with the L2 MERIS reflectance imagery that we have tried to use for model calibration. We present the results of the study carried on six reservoirs in northeastern Spain. In a date coincident with a MERIS image (June 19th, 2003) we have collected pigment concentration and reflectance data measured from a

  4. Pigmented Pindborg tumor of the maxilla: A case report

    PubMed Central

    Priya, Subashchandrabose; Madanagopaal, Lakshmikanth Ramiah; Sarada, Venkaterwaran

    2016-01-01

    The calcifying epithelial odontogenic tumor (CEOT), also known as the Pindborg tumor, is a benign locally invasive neoplasm. Common variants of CEOT include noncalcifying, Langerhans cell, bone and cementum forming and clear cell, which have a prognostic significance. Pigmented variants are known to occur in other odontogenic tumors. However, a definitive pigmented variant of CEOT has not been reported in literature so far. Here, we report the first case of pigmented Pindborg tumor arising from the maxilla in a young female. The pigment was demonstrated as melanin by staining and confirmed by immunohistochemistry. The pigmented variant of CEOT did not recur within 18 months postsurgery. Our report indicates that it is essential to recognize the pigmented variant. We discuss the common variants of CEOT and potential histogenesis of the pigmented variant. Further studies are required to reveal the histogenesis of melanocytes and their pathological significance in the odontogenic tumors. PMID:27721633

  5. 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.

  6. Retinal Pigment Epithelium Tears: Risk Factors, Mechanism and Therapeutic Monitoring.

    PubMed

    Clemens, Christoph R; Eter, Nicole

    2016-01-01

    Tears of the retinal pigment epithelium (RPE) are most commonly associated with vascularised RPE detachment due to age-related macular degeneration (AMD), and they usually involve a deleterious loss in visual acuity. Recent studies suggest an increase in RPE tear incidences since the introduction of anti-vascular endothelial growth factor (anti-VEGF) therapies as well as a temporal association between the tear event and the intravitreal injection. As the number of AMD patients and the number of administered anti-VEGF injections increase, both the challenge of RPE tear prevention and the treatment after RPE tear formation have become more important. At the same time, the evolution of retinal imaging has significantly contributed to a better understanding of RPE tear development in recent years. This review summarises the current knowledge on RPE tear development, predictive factors, and treatment strategies before and after RPE tear formation.

  7. 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.

  8. Animal pigment bilirubin discovered in plants.

    PubMed

    Pirone, Cary; Quirke, J Martin E; Priestap, Horacio A; Lee, David W

    2009-03-04

    The bile pigment bilirubin-IXalpha is the degradative product of heme, distributed among mammals and some other vertebrates. It can be recognized as the pigment responsible for the yellow color of jaundice and healing bruises. In this paper we present the first example of the isolation of bilirubin in plants. The compound was isolated from the brilliant orange-colored arils of Strelitzia nicolai, the white bird of paradise tree, and characterized by HPLC-ESMS, UV-visible, (1)H NMR, and (13)C NMR spectroscopy, as well as comparison with an authentic standard. This discovery indicates that plant cyclic tetrapyrroles may undergo degradation by a previously unknown pathway. Preliminary analyses of related plants, including S. reginae, the bird of paradise, also revealed bilirubin in the arils and flowers, indicating that the occurrence of bilirubin is not limited to a single species or tissue type.

  9. Influence of pigment and opacifier on dimensional stability and detail reproduction of maxillofacial silicone elastomer.

    PubMed

    Haddad, Marcela Filié; Goiato, Marcelo Coelho; Dos Santos, Daniela Micheline; Pesqueira, Aldiéris Alves; Moreno, Amália; Pellizzer, Eduardo Piza

    2011-09-01

    We evaluated the influence of chemical disinfection and accelerated aging on the dimensional stability and detail reproduction of a silicone elastomer containing an opacifier and/or a pigment. A total of 120 samples were fabricated from Silastic MDX 4-4210 silicone and divided into groups (n = 10) according to pigment and/or opacifier (ceramic powder and/or barium sulfate) and disinfectant solution (neutral soap, Efferdent, or 4% chlorhexidine). The specimens were disinfected 3 times per week during 60 days and then subjected to accelerated aging for 1008 hours. Dimensional stability and detail reproduction tests were performed after specimens' fabrication (baseline) and chemical disinfection and periodically during accelerated aging (252, 504, and 1008 hours). The results were analyzed using 3-way repeated-measures analysis of variance and the Tukey Honestly Significant Difference test (a = 0.05). All groups exhibited dimensional changes over time. The disinfectant, pigment, and time (P < 0.0001) affected the dimensional stability of silicone. Statistically significant dimensional differences were not observed between the tested groups. Accelerated aging influenced the dimensional stability of the samples. All groups scored 2 in the detail reproduction tests, which represents the full reproduction of 3 test grooves with accurate angles. Incorporation of opacifier and/or pigment alters the dimensional stability of silicones used in facial prosthetics but seems to have no influence on detail reproduction. Accelerated aging is responsible for most of the dimensional changes in Silastic MDX4 4210, but all dimensional changes measured in this study remained within the limits of stability necessary for this application.

  10. FRUIT AND VEGETABLE PIGMENTS AS INDICATORS.

    PubMed

    Pratt, O B; Swartout, H O

    1930-05-09

    (1) Solutions of many fruit pigments act as indicators. (2) These solutions are easily prepared and stable, and the pH range of their color changes is in most cases conveniently near the neutral point (3) As liquid indicators they can be used in titrating acids, but not bases (4)Their greatest usefulness depends upon the fact that very satisfactory test papers can be made with them in a simple and inexpensive way.

  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. Treatment of gingival pigmentation: a case series.

    PubMed

    Deepak, Prasad; Sunil, S; Mishra, R; Sheshadri

    2005-01-01

    A smile expresses a feeling of joy, success, sensuality, affection and courtesy, and reveals self confidence and kindness. The harmony of the smile is determined not only by the shape, the position and the color of the teeth but also by the gingival tissues. Gingival health and appearance are essential components of an attractive smile. Gingival pigmentation results from melanin granules, which are produced by melanoblasts. The degree of pigmentation depends on melanoblastic activity. Although melanin pigmentation of the gingiva is completely benign and does not present a medical problem, complaints of 'black gums' are common particularly in patients having a very high smile line (gummy smile). For depigmentation of gingiva different treatment modalities have been reported like- Bur abrasion, scraping, partial thickness flap, cryotherapy, electrosurgery and laser. In the present case series bur abrasion, scraping, partial thickness flap (epithelial excision) cryotherapy and electrosurgery have been tried for depigmentation, which are simple, effective and yield good results, along with good patient satisfaction. The problems encountered with some of these techniques have also been discussed.

  13. 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.

  14. Acceleration of the aging process by oxygen

    NASA Technical Reports Server (NTRS)

    Miquel, J.; Lunderen, P. R.; Bensch, K. G.

    1975-01-01

    Tissue changes induced by hyperoxia have been compared with those of normal aging. Results of investigations using male flies prompt conclusion that normal aging, radiation syndrome, and hyperoxic injury share at least one common feature--lipid peroxidation damage to all mambranes resulting in accumulation of age pigment.

  15. 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.

  16. 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.

  17. Associations Between Retinal Pigment Epithelium and Drusen Volume Changes During the Lifecycle of Large Drusenoid Pigment Epithelial Detachments

    PubMed Central

    Balaratnasingam, Chandrakumar; Yannuzzi, Lawrence A.; Curcio, Christine A.; Morgan, William H.; Querques, Giuseppe; Capuano, Vittorio; Souied, Eric; Jung, Jesse; Freund, K. Bailey

    2016-01-01

    Purpose Drusenoid pigment epithelial detachments (PEDs) are a defined path to atrophy in age-related macular degeneration (AMD). We analyzed the relationships between retinal pigment epithelium (RPE) and drusen volume changes during the PED lifecycle, using spectral-domain optical coherence tomography (SD-OCT). Methods Twenty-one cases of drusenoid PED tracked using SD-OCT through periods of growth and collapse were evaluated. Volumetric calculations and piece-wise linear regression analysis were used to determine the breakpoint between growth and collapse. Spectral-domain OCT scans were independently evaluated for the appearance of intraretinal hyperreflective foci, acquired vitelliform lesions (AVLs), and disruptions to the RPE+basal lamina band. Timing of these events with respect to the breakpoint was statistically evaluated. Morphometric characteristics of drusenoid PEDs were correlated with rate of PED collapse and final visual acuity. Results Mean age of subjects was 75.3 years and mean period of follow up was 4.1 years (median 4.5 years; range, 0.6–6.6 years). The lifecycle of drusenoid PEDs was asymmetric, in that the rate of collapse (0.199 mm3/month) is significantly faster (P < 0.001) than the rate of growth (0.022 mm3/month). Appearance of intraretinal hyperreflective foci and AVLs preceded the breakpoint (both P < 0.001). The timing of disruptions to the RPE+basal lamina band did not differ from the breakpoint (P = 0.510). Maximal height, volume, and diameter of drusenoid PEDs were inversely correlated with final visual acuity (all P < 0.001) and positively correlated with the rate of PED collapse (all P < 0.001). Conclusions Spectral-domain OCT signatures, plausibly attributable to anteriorly migrated RPE and disintegration of the RPE layer, precede or occur simultaneously with changes in volume of drusenoid PED during the lifecycle of this lesion. PMID:27760262

  18. High-contrast enzymatic immunohistochemistry of pigmented tissues

    PubMed Central

    Duncan, Sara M.; Seigel, Gail M.

    2016-01-01

    Historically, standard enzyme immunohistochemistry has been accomplished with brown (DAB, diaminobenzidine) substrate. This can become problematic in pigmented tissues, such as the retina, where brown pigment of retinal pigmented epithelial (RPE) cells can be easily confounded with brown substrate. Although immunofluorescence detection methods can overcome this challenge, fluorescence may fade over a period of weeks, while enzyme substrates allow for more long-lasting, archival results. In this report, we will describe a high-contrast enzyme immunohistochemistry method ideal for pigmented tissues that utilizes purple (VIP) substrate. We compared brown (DAB) and purple (VIP) substrates in enzyme immunohistochemistry experiments using human retina (paraffin sections) and monkey retinal pigmented epithelial cells (frozen sections), both containing brown pigmented cells. We compared substrates using several primary antibodies against markers that can be detected in the retina, including GFAP, VEGF, CD147 (EMMPRIN), RHO (rhodopsin) and PAX6. Methyl green was used as a counterstain for paraffin sections. A side-by-side comparison between DAB and VIP immunohistochemistry showed excellent contrast between pigmented cells and the purple VIP substrate in both human retinal tissue and monkey pigmented epithelial cells for all of the markers tested. This was a marked improvement over DAB staining in pigmented cells and tissues. For both paraffin sections and frozen sections of pigmented tissues, purple VIP substrate is an excellent alternative to brown DAB substrate and non-permanent immunofluorescence methods. PMID:27660801

  19. GREEN FLUORESCENT PIGMENT ACCUMULATED BY A MUTANT OF CELLVIBRIO GILVUS.

    PubMed

    LOVE, S H; HULCHER, F H

    1964-01-01

    Love, Samuel H. (Bowman Gray School of Medicine, Winston-Salem, N.C.), and Frank H. Hulcher. Green fluorescent pigment accumulated by a mutant of Cellvibrio gilvus. J. Bacteriol. 87:39-45. 1964.-A mutant of Cellvibrio gilvus, designated strain 139A, liberated a green, fluorescent pigment into the surrounding culture medium. A study of the factors which affected the accumulation of this pigment led to the development of a chemically defined medium which supported maximal pigment accumulation in aerated, liquid cultures. d-Glucose, glycine or l-serine, l-phenylalanine, l-proline, and l-lysine comprised the organic components of this medium. The visible absorption spectrum of the pigment showed a maximal band at 400 mmu (pH 7.0). A difference spectrum between reduced and oxidized pigment showed loss of the band at 400 mmu upon oxidation. However, a methanol-extractable, flavinelike compound occurred in the wild strain but not in the mutant. Ferric ions added to the defined medium stimulated growth, with a concomitant reduction of pigment accumulation. Pigment was formed at a maximal rate during the stationary growth phase, and the highest yield was obtained by 18 hr. Organic solvents did not extract the pigment from water solutions. One and sometimes two, compounds absorbing at 400 mmu could be eluted by ion-exchange chromatography on Cellex-P (H(+)), which was used to separate the pigment from other components in the culture supernatants so that the radioactivity of the pigment could be measured. The mutant synthesized C(14)-labeled pigment from d-glucose-U-C(14) and from each of four amino acids (glycine-1-C(14), l-phenylalanine-U-C(14), l-proline-U-C(14), and l-lysine-U-C(14). Delta-Amino-levulenic acid-4-C(14) did not contribute C(14) to the pigment.

  20. Origins of adult pigmentation: diversity in pigment stem cell lineages and implications for pattern evolution

    PubMed Central

    Spiewak, Jessica E.

    2014-01-01

    Summary Teleosts comprise about half of all vertebrate species and exhibit an extraordinary diversity of adult pigment patterns that function in shoaling, camouflage and mate choice and have played important roles in speciation. Here, we review recent studies that have identified several distinct neural crest lineages, with distinct genetic requirements, that give rise to adult pigment cells in fishes. These lineages include post-embryonic, peripheral nerve associated stem cells that generate black melanophores and iridescent iridophores, cells derived directly from embryonic neural crest cells that generate yellow-orange xanthophores, and bipotent stem cells that generate both melanophores and xanthophores. This complexity in adult chromatophore lineages has implications for our understanding of adult traits, melanoma, and the evolutionary diversification of pigment cell lineages and patterns. PMID:25421288

  1. Origins of adult pigmentation: diversity in pigment stem cell lineages and implications for pattern evolution.

    PubMed

    Parichy, David M; Spiewak, Jessica E

    2015-01-01

    Teleosts comprise about half of all vertebrate species and exhibit an extraordinary diversity of adult pigment patterns that function in shoaling, camouflage, and mate choice and have played important roles in speciation. Here, we review studies that have identified several distinct neural crest lineages, with distinct genetic requirements, that give rise to adult pigment cells in fishes. These lineages include post-embryonic, peripheral nerve-associated stem cells that generate black melanophores and iridescent iridophores, cells derived directly from embryonic neural crest cells that generate yellow-orange xanthophores, and bipotent stem cells that generate both melanophores and xanthophores. This complexity in adult chromatophore lineages has implications for our understanding of adult traits, melanoma, and the evolutionary diversification of pigment cell lineages and patterns.

  2. Characterization of Sorolla's gouache pigments by means of spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Roldán, Clodoaldo; Juanes, David; Ferrazza, Livio; Carballo, Jorgelina

    2016-02-01

    This paper presents the characterization of the Joaquín Sorolla's gouache sketches for the oil on canvas series "Vision of Spain" commissioned by A. M. Huntington to decorate the library of the Hispanic Society of America in New York. The analyses were focused on the identification of the elemental composition of the gouache pigments by means of portable EDXRF spectrometry in a non-destructive mode. Additionally, SEM-EDX and FTIR analyses of a selected set of micro-samples were carried out to identify completely the pigments, the paint technique and the binding media. The obtained results have confirmed the identification of lead and zinc white, vermillion, earth pigments, ochre, zinc yellow, chrome yellow, ultramarine, Prussian blue, chromium based and copper-arsenic based green pigments, bone black and carbon based black pigments, and the use of gum arabic as binding media in the gouache pigments.

  3. Analytical Raman spectroscopic discrimination between yellow pigments of the Renaissance.

    PubMed

    Edwards, Howell G M

    2011-10-01

    The Renaissance represented a major advance in painting techniques, subject matter, artistic style and the use of pigments and pigment mixtures. However, most pigments in general use were still mineral-based as most organic dyes were believed to be fugitive; the historical study of artists' palettes and recipes has assumed importance for the attribution of art works to the Renaissance period. Although the application of diagnostic elemental and molecular spectroscopic techniques play vital and complementary roles in the analysis of art works, elemental techniques alone cannot definitively provide the data needed for pigment identification. The advantages and limitations of Raman spectroscopy for the definitive diagnostic characterisation of yellow pigments that were in use during the Renaissance is demonstrated here in consideration of heavy metal oxides and sulphides; these data will be compared with those obtained from analyses of synthetic yellow pigments that were available during the eighteenth and nineteenth Centuries which could have been used in unrecorded restorations of Renaissance paintings.

  4. Oral pigmented lesions: Clinicopathologic features and review of the literature

    PubMed Central

    da Silva-Jorge, Rogério; Jorge, Jacks; Lopes, Márcio A.; Vargas, Pablo A.

    2012-01-01

    Diagnosis of pigmented lesions of the oral cavity and perioral tissues is challenging. Even though epidemiology may be of some help in orientating the clinician and even though some lesions may confidently be diagnosed on clinical grounds alone, the definitive diagnosis usually requires histopathologic evaluation. Oral pigmentation can be physiological or pathological, and exogenous or endogenous. Color, location, distribution, and duration as well as drugs use, family history, and change in pattern are important for the differential diagnosis. Dark or black pigmented lesions can be focal, multifocal or diffuse macules, including entities such as racial pigmentation, melanotic macule, melanocytic nevus, blue nevus, smoker’s melanosis, oral melanoacanthoma, pigmentation by foreign bodies or induced by drugs, Peutz-Jeghers syndrome, Addison´s disease and oral melanoma. The aim of this review is to present the main oral black lesions contributing to better approach of the patients. Key words:Pigmentation, melanin, oral, diagnosis, management. PMID:22549672

  5. Mapping pigment distribution in mud samples through hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Mehrübeoglu, Mehrube; Nicula, Cosmina; Trombley, Christopher; Smith, Shane W.; Smith, Dustin K.; Shanks, Elizabeth S.; Zimba, Paul V.

    2015-09-01

    Mud samples collected from bodies of water reveal information about the distribution of microorganisms in the local sediments. Hyperspectral imaging has been investigated as a technology to identify phototropic organisms living on sediments collected from the Texas Coastal Bend area based on their spectral pigment profiles and spatial arrangement. The top pigment profiles identified through high-performance liquid chromatography (HPLC) have been correlated with spectral signatures extracted from the hyperspectral data of mud using fast Fourier transform (FFT). Spatial distributions have also been investigated using 2D hyperspectral image processing. 2D pigment distribution maps have been created based on the correlation with pigment profiles in the FFT domain. Among the tested pigments, the results show match among four out of five pigment distribution trends between HPLC and hyperspectral data analysis. Differences are attributed mainly to the difference between area and volume of scale between the HPLC analysis and area covered by hyperspectral imaging.

  6. Ginger and alpha lipoic acid ameliorate age-related ultrastructural changes in rat liver.

    PubMed

    Mahmoud, Y I; Hegazy, H G

    2016-01-01

    Because of the important role that oxidative stress is thought to play in the aging process, antioxidants could be candidates for preventing its related pathologies. We investigated the ameliorative effects of two antioxidant supplements, ginger and alpha lipoic acid (ALA), on hepatic ultrastructural alterations in old rats. Livers of young (4 months) and old (24 months) Wistar rats were studied using transmission electron microscopy. Livers of old rats showed sinusoidal collapse and congestion, endothelial thickening and defenestration, and inconsistent perisinusoidal extracellular matrix deposition. Aged hepatocytes were characterized by hypertrophy, cytoplasmic vacuolization and a significant increase in the volume densities of the nuclei, mitochondria and dense bodies. Lipofuscin accumulation and decreased microvilli in bile canaliculi and space of Disse also were observed. The adverse alterations were ameliorated significantly by both ginger and ALA supplementation; ALA was more effective than ginger. Ginger and ALA appear to be promising anti-aging agents based on their amelioration of ultrastructural alterations in livers of old rats.

  7. Fine structural changes in the lateral vestibular nucleus of aging rats

    NASA Technical Reports Server (NTRS)

    Johnson, J. E., Jr.; Miquel, J.

    1974-01-01

    The fine structure of the lateral vestibular nucleus was investigated in Sprague-Dawley rats, that were sacrified at 4 weeks, 6-8 weeks, 6-8 months, and 18-20 months of age. In the neuronal perikaria, the following age-associated changes were seen with increasing frequency with advancing age: rodlike nuclear inclusions and nuclear membrane invaginations; cytoplasmic dense bodies with the characteristics of lipofuscin; and moderate disorganization of the granular endoplasmic reticulum. Dense bodies were also seen in glial cells. Rats 18 to 20 months old showed dendritic swellings, axonal degeneration, and an apparent increase in the number of axosomatic synaptic terminals containing flattened vesicles (presumed to be inhibitory in function).

  8. Protective responses to sublytic complement in the retinal pigment epithelium

    PubMed Central

    Tan, Li Xuan; Toops, Kimberly A.; Lakkaraju, Aparna

    2016-01-01

    The retinal pigment epithelium (RPE) is a key site of injury in inherited and age-related macular degenerations. Abnormal activation of the complement system is a feature of these blinding diseases, yet how the RPE combats complement attack is poorly understood. The complement cascade terminates in the cell-surface assembly of membrane attack complexes (MACs), which promote inflammation by causing aberrant signal transduction. Here, we investigated mechanisms crucial for limiting MAC assembly and preserving cellular integrity in the RPE and asked how these are compromised in models of macular degeneration. Using polarized primary RPE and the pigmented Abca4−/− Stargardt disease mouse model, we provide evidence for two protective responses occurring within minutes of complement attack, which are essential for maintaining mitochondrial health in the RPE. First, accelerated recycling of the membrane-bound complement regulator CD59 to the RPE cell surface inhibits MAC formation. Second, fusion of lysosomes with the RPE plasma membrane immediately after complement attack limits sustained elevations in intracellular calcium and prevents mitochondrial injury. Cholesterol accumulation in the RPE, induced by vitamin A dimers or oxidized LDL, inhibits these defense mechanisms by activating acid sphingomyelinase (ASMase), which increases tubulin acetylation and derails organelle traffic. Defective CD59 recycling and lysosome exocytosis after complement attack lead to mitochondrial fragmentation and oxidative stress in the RPE. Drugs that stimulate cholesterol efflux or inhibit ASMase restore both these critical safeguards in the RPE and avert complement-induced mitochondrial injury in vitro and in Abca4−/− mice, indicating that they could be effective therapeutic approaches for macular degenerations. PMID:27432952

  9. 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.

  10. Chlorpromazine-induced skin pigmentation with corneal and lens opacities.

    PubMed

    Huff, Laura S; Prado, Renata; Pederson, Jon F; Dunnick, Cory A; Lucas, Lisa M

    2014-05-01

    Chlorpromazine is known to cause abnormal oculocutaneous pigmentation in sun-exposed areas. We present the case of a psychiatric patient who developed blue-gray pigmentation of the skin as well as corneal and lens opacities following 7 years of chlorpromazine treatment. Ten months after discontinuation of chlorpromazine, the skin discoloration and anterior lens deposits showed partial improvement, but the corneal deposits remained unchanged. A review of the literature on the reversibility of chlorpromazine-induced abnormal oculocutaneous pigmentation also is provided.

  11. BASIS FOR ENHANCED BARRIER FUNCTION OF PIGMENTED SKIN

    PubMed Central

    Man, Mao-Qiang; Lin, Tzu-Kai; Santiago, Juan Luis; Celli, Anna; Zhong, Lily; Huang, Zhi-Ming; Roelandt, Truus; Hupe, Melanie; Sundberg, John P.; Silva, Kathleen A.; Crumrine, Debra; Martin-Ezquerra, Gemma; Trullas, Carles; Sun, Richard; Wakefield, Joan S.; Wei, Maria L.; Feingold, Kenneth R.; Mauro, Theodora M.; Elias, Peter M.

    2014-01-01

    Humans with darkly-pigmented skin display superior permeability barrier function in comparison to humans with lightly-pigmented skin. The reduced pH of the stratum corneum (SC) of darkly-pigmented skin could account for enhanced function, because acidifying lightly-pigmented human SC resets barrier function to darkly-pigmented levels. In SKH1 (non-pigmented) vs. SKH2/J (pigmented) hairless mice, we evaluated how a pigment-dependent reduction in pH could influence epidermal barrier function. Permeability barrier homeostasis is enhanced in SKH2/J vs. SKH1 mice, correlating with a reduced pH in the lower SC that co-localizes with the extrusion of melanin granules. Darkly-pigmented human epidermis also shows substantial melanin extrusion in the outer epidermis. Both acute barrier disruption and topical basic pH challenges accelerate re-acidification of SKH2/J (but not SKH1) SC, while inducing melanin extrusion. SKH2/J mice also display enhanced expression of the SC acidifying enzyme, secretory phospholipase A2f (sPLA2f). Enhanced barrier function of SKH2/J mice could be attributed to enhanced activity of two acidic pH-dependent, ceramide-generating enzymes, β-glucocerebrosidase and acidic sphingomyelinase, leading to accelerated maturation of SC lamellar bilayers. Finally, organotypic cultures of darkly-pigmented-bearing human keratinocytes display enhanced barrier function in comparison to lightly-pigmented cultures. Together, these results suggest that the superior barrier function of pigmented epidermis can be largely attributed to the pH-lowering impact of melanin persistence/extrusion and enhanced sPLA2f expression. PMID:24732399

  12. Production of luteoskyrin, a hepatotoxic pigment, by Penicillium islandicum Sopp.

    PubMed

    Ueno, Y; Ishikawa, I

    1969-09-01

    Various factors affecting the yields of luteoskyrin, a hepatotoxic mycotoxin, and related pigments in the liquid medium were studied. Maximal yields of luteoskyrin (0.13% by isolation) and of other pigments were attained in the late phase of the cultivation. The yield of the pigment was increased by supplying malt extract, malonic acid, glutamic acid, or asparagine. A useful material for preparation of (14)C-labeled luteoskyrin was 2-(14)C-malonate.

  13. Atmospheric effects in the remote sensing of phytoplankton pigments

    NASA Technical Reports Server (NTRS)

    Gordon, H. R.; Clark, D. K.

    1980-01-01

    The accuracy with which relevant atmospheric parameters must be estimated to derive photoplankton pigment concentrations of a given accuracy, from measurements of the ocean's apparent spectral radiance at satellite altitudes, is examined. A phytoplankton pigment algorithm is developed which relates the pigment concentration (c) to the three ratios of upwelling radiance just beneath the sea surface which can be formed from wavelengths (lambda) 440, 520 and 550 nm.

  14. FRACTIONATION OF THE EYE PIGMENTS OF DROSOPHILA MELANOGASTER.

    PubMed

    Wald, G; Allen, G

    1946-09-20

    Eye pigments of normal and mutant types of D. melanogaster have been extracted with water and fractionated by chromatographic adsorption on powdered talc. Spectra of all the fractions obtainable in solution have been measured and the general chemical behavior of the pigments is described. Two chemically distinct groups of pigments are found, to be identified with the earlier designated red and brown components. The red component in the wild-type eye contains three well defined pigments, two of them capable of further subdivision so that the total number of fractions obtained is five. There is also present a brown component pigment which could not be treated quantitatively by the methods employed. All members of the wild-type red component are found in cinnabar eyes, unaccompanied by the brown component. Conversely, brown eyes contain a pigment indistinguishable from the wild-type brown component, virtually alone. In sepia eyes, one red component and two brown component pigments can be distinguished, all three pigments differing from those of wild-type eyes. Pigments apparently identical with those found in wild-type melanogaster eyes have also been found in D. virilis.

  15. Dichroism measurements in forensic fibre examination: part 5-pigmented fibres.

    PubMed

    De Wael, K; Lepot, L

    2012-09-01

    A number of pigmented fibre samples were examined with plane polarized light on their dichroic behaviour by optical light microscopy (OLM) and microspectrophotometry with plane polarized light (MSP-PPL). It was found that about half of the samples show a strong dichroic effect and another 20% have a weak dichroism. Both regular (80%) and inversed dichroic effects (20%) occur. The dichroic characteristics of pigmented fibres can be compared to these of sheet polarizers. It is suggested that the dichroic behaviour of pigmented fibres depends strongly on the crystal structure (shape of the pigment grains) and the draw ratio (orientation of the polymer chains).

  16. Abnormal pigmentation within cutaneous scars: A complication of wound healing

    PubMed Central

    Chadwick, Sarah; Heath, Rebecca; Shah, Mamta

    2012-01-01

    Abnormally pigmented scars are an undesirable consequence of cutaneous wound healing and are a complication every single individual worldwide is at risk of. They present a challenge for clinicians, as there are currently no definitive treatment options available, and render scars much more noticeable making them highly distressing for patients. Despite extensive research into both wound healing and the pigment cell, there remains a scarcity of knowledge surrounding the repigmentation of cutaneous scars. Pigment production is complex and under the control of many extrinsic and intrinsic factors and patterns of scar repigmentation are unpredictable. This article gives an overview of human skin pigmentation, repigmentation following wounding and current treatment options. PMID:23162241

  17. Neodymium-YAG transscleral cyclophotocoagulation. The role of pigmentation

    SciTech Connect

    Cantor, L.B.; Nichols, D.A.; Katz, L.J.; Moster, M.R.; Poryzees, E.; Shields, J.A.; Spaeth, G.L. )

    1989-08-01

    Using a rabbit model we investigated the role of pigmentation of the ciliary body in obtaining ciliodestruction by neodymium-YAG transscleral cyclophotocoagulation. There was marked destruction of the ciliary body in pigmented rabbit eyes, but no histologic effect was observed in albino rabbit eyes. These findings suggest that pigmentation of the ciliary body is important for obtaining the desired response from neodymium-YAG transscleral cyclophotocoagulation in rabbit eyes by our technique. Further study is necessary to define the role of pigmentation in human eyes in this treatment modality.

  18. Early Diagenesis of Plant Pigments in Hudson River Sediments

    NASA Astrophysics Data System (ADS)

    Bianchi, Thomas S.; Dibb, Jack E.; Findlay, Stuart

    1993-06-01

    Plant pigment concentrations were measured using high performance liquid chromatography in Hudson River sediments. Sedimentation rates and mixing characteristics were determined from depth profiles of the naturally occurring radionuclides 7Be, 210Pb. Previous estimates of the mean-lives (1/λ) of plant pigments (chlorophylls a and b, fucoxanthin) from laboratory experiments, indicate a range of c. 20-40 days. However, in the field, we observed that these pigments decreased less rapidly with depth and penetrated deeper than 7Be (mean-life 77 days) in Hudson sediments 95% of the time. Assuming similar mixing processes for particles carrying 7Be and pigments, this indicates that pigment decay rates in the field are slower than the 0·013 day -1 decay rate of 7Be, hence, more than 2-fold slower than the derived laboratory rates. We believe that high inputs of vascular plant detritus in the Hudson may increase the complexation of humic substances with pigments resulting in slower decay rates. While most pigments showed an exponential decrease with sediment depth, lutein concentrations generally increased with depth. This pattern of decay resistance is in agreement with laboratory experiments which show that lutein is the most decay resistant among dominant pigments. These data along with other studies demonstrate that the carotenoids lacking the 5,6-epoxide group (i.e., lutein) are more decay resistant than pigments that contain it (i.e., fucoxanthin).

  19. Reflective color display using thermochromic pigments.

    PubMed

    Heo, Kyong Chan; Sohn, Youngku; Yi, Jonghoon; Kwon, Jin Hyuk; Son, Phil Kook; Gwag, Jin Seog

    2012-06-20

    A reflective thermochromic display fabricated by a very simple method using three kinds of thermochromic pigments is produced and its thermo-optical characteristics are investigated. The display exhibits maximum red, green, and blue reflectances of 38%, 30%, and 35%, respectively. The reflective display cell shows continuous gray color with changing temperature, which is crucial for multicolor displays. It also shows an excellent viewing angle above 80° without any of the additional optical components that are required in liquid crystal displays. We expect that this display technology will be used for outdoor billboard information display applications.

  20. LOCALIZED PIGMENTED VILLONODULAR SYNOVITIS: CASE REPORT.

    PubMed

    Carvalho Godoy, Fabiola Andrea de; Faustino, Carlos Alberto Cury; Meneses, Cláudio Santos; Nishi, Sergio Tadao; Góes, César Eduardo Giancoli; Canto, Abaeté Leite do

    2011-01-01

    This case concerned a female patient with a complaint of pain in the anterior region of her left knee during and after sports activities, followed by joint blockage three months ago. From imaging examinations, simple radiography of the knee was normal and magnetic resonance showed a solid expansive mass, possibly corresponding to soft-tissue chondroma or focal nodular synovitis. Arthroscopic resection of the lesion was performed, and the diagnosis of diffuse giant cell tumor resembling localized pigmented villonodular synovitis (PVNS) was made from the result of the anatomopathological examination. The patient presented good clinical evolution, with disappearance of symptoms and return to physical activities.

  1. LOCALIZED PIGMENTED VILLONODULAR SYNOVITIS: CASE REPORT

    PubMed Central

    Carvalho Godoy, Fabiola Andrea de; Faustino, Carlos Alberto Cury; Meneses, Cláudio Santos; Nishi, Sergio Tadao; Góes, César Eduardo Giancoli; Canto, Abaeté Leite do

    2015-01-01

    This case concerned a female patient with a complaint of pain in the anterior region of her left knee during and after sports activities, followed by joint blockage three months ago. From imaging examinations, simple radiography of the knee was normal and magnetic resonance showed a solid expansive mass, possibly corresponding to soft-tissue chondroma or focal nodular synovitis. Arthroscopic resection of the lesion was performed, and the diagnosis of diffuse giant cell tumor resembling localized pigmented villonodular synovitis (PVNS) was made from the result of the anatomopathological examination. The patient presented good clinical evolution, with disappearance of symptoms and return to physical activities. PMID:27027040

  2. Characterization of Brevibacterium linens pigmentation using spectrocolorimetry.

    PubMed

    Guyomarc'h, F; Binet, A; Dufossé, L

    2000-06-15

    Spectrocolorimetry was used for the evaluation of Brevibacterium linens pigmentation. A total of 23 strains of Brevibacterium linens, from various sources, were plated onto solid agar media and their color coordinates were measured and expressed by the L*a*b* colorimetric system. All the strains were located along a straight line with a hue of 66 degrees (orange color). The effect of light exposure versus storage in the dark was also investigated using this approach. Three groups with distinct behaviors were demonstrated for the 23 B. linens strains.

  3. 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.

  4. Method of preparing zinc orthotitanate pigment

    NASA Technical Reports Server (NTRS)

    Gates, D. W.; Harada, Y.; Logan, W. R.; Gilligan, J. E. (Inventor)

    1977-01-01

    Zinc orthotitanate suitable for use as a pigment for spacecraft thermal control coatings is prepared by heating a slightly zinc deficient reaction mixture of precipitated oxalates of zinc and titanium. The reaction mixture can be formed by coprecipitation of zinc and titanium oxalates from chloride solution or by mixing separately precipitated oxalates. The mixture is first heated to 400 to 600 C to remove volatiles and is then rapidly heated at 900 to 1200 C. Zinc orthotitanate produced by this method exhibits the very fine particle size needed for thermal control coatings as well as stability in a space environment.

  5. 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

  6. The pigmentation of human iris influences the uptake and storing of zinc.

    PubMed

    Kokkinou, Despina; Kasper, Haino Uwe; Bartz-Schmidt, Karl Ulrich; Schraermeyer, Ulrich

    2004-10-01

    Age-related macular degeneration (AMD) is more prevalent among the elderly Caucasians than in Africans. A significant association between light iris colour, fundus pigmentation and incidence of AMD is reported, suggesting a possible correlation with melanin pigment. Zinc is known to bind to melanin in pigmented tissues and to enhance antioxidant capacity by function as a cofactor or gene expression factor of antioxidant enzymes in the eye. In this in vitro study, we investigated the uptake and storage of zinc in human irides. Irides of blue and brown human eyes were used. The number of melanocytes was measured. Tissues without any treatment served as controls. The irides were incubated with 100 microM zinc chloride in culture medium for 24 h. Specimens of the tissues were stored for the uptake examination. The remained pieces were further incubated for 3 and 7 d to investigate the storage of zinc. The concentration of zinc was measured by inductively coupled plasma mass spectrometry (ICP-MS). Melanocytes count was significantly higher in the brown tissues (P < 0.0001). Zinc concentration of blue coloured irides after 24 h zinc treatment was close to the controls. We did not observe any significant storing. In contrast, the concentration of zinc in brown irides was significantly increased after 24 h (P < or = 0.01) and remained at a high level for 7 d. The uptake of zinc is likely dependent on the amount of pigmentation in human iris. Therefore, we assume that in patients suffering from AMD the degree of pigmentation of the irides and eventually fundi should be under consideration when the patients are treated with zinc supplementation.

  7. Properties of wine polymeric pigments formed from anthocyanin and tannins differing in size distribution and subunit composition.

    PubMed

    Bindon, Keren; Kassara, Stella; Hayasaka, Yoji; Schulkin, Alex; Smith, Paul

    2014-11-26

    To explore the effect of tannin composition on pigment formation, model ferments of purified 3-O-monoglucoside anthocyanins (ACN) were conducted either alone or in the presence of two different tannins. Tannins were isolated from grape seeds (Sd) or skins (Sk) following exhaustive extraction in 70% v/v acetone. The Sd and Sk tannin fractions had a mean degree of polymerization of 5.2 and 25.6, respectively. The Sd fraction was highly galloylated, at 22%, but galloylation was <2% in the Sk fraction. The Sk fraction was distinguished by a high proportion of prodelphinidin, at 58%. After a 6 month aging period, polymeric pigments were quantified and their color properties determined following isolation by solid-phase extraction. Wine color and polymeric pigment were highest in the treatment containing ACN+Sd and similar in the ACN+Sk and ACN treatments. The same trend between treatments was observed for total and polymeric nonbleachable pigments. Only minor changes in tannin subunit composition were found following ACN incorporation, but the size distribution of polymeric pigments determined by gel permeation chromatography decreased, in particular for the ACN+Sk treatment. Color incorporation in the higher molecular mass range was lower for ACN+Sk wines than for ACN+Sd wines. Compositional differences between the two tannin fractions may therefore limit the incorporation of ACNs in the colored form. The results suggest that in the ACN+Sk and ACN treatments, the formation of lower molecular mass oligomeric pigments was favored. In polymeric pigments derived from ACNs, the presence of ethyl- and vinyl-linked ACNs to the level of trimers was identified using mass spectrometry.

  8. Photoinduced changes in photosystem II pigments

    NASA Astrophysics Data System (ADS)

    Andreeva, Atanaska S.; Busheva, Mira C.; Stoitchkova, Katerina V.; Tzonova, Iren K.

    2010-11-01

    The photosynthetic apparatus in higher plants performs two seemingly opposing tasks: efficient harvest of sunlight, but also rapid and harmless dissipation of excess light energy as heat to avoid deleterious photodamage. In order to study this process in pigment-protein supercomplexes of photosystem II (PSII), 77 K fluorescence and room temperature resonance Raman (RR) spectroscopy were applied to investigate the changes in structure and spectral properties of the pigments in spinach PSII membranes. The high-light treatment results in a strong quenching of the fluorescence (being largest when the excitation is absorbed by carotenoids) and a red-shift of the main maximum. Decomposition of the fluorescence spectra into four bands revealed intensive quenching of F685 and F695 bands, possible bleaching of chlorophyll a, enhanced extent of light harvesting complexes (LHCII) aggregation and increased energy transfer to aggregated LHCII. The analysis of RR spectra revealed the predominant contribution of ß-carotene (ß-Car) upon 457.8 and 488 nm excitations and lutein (Lut) at 514.5 nm. During prolonged exposure to strong light no significant bleaching of ß-Car and weak photobleaching of Lut is observed. The results will contribute to the efforts to produce more efficient and robust solar cells when exposed to fluctuations in light intensity.

  9. Enamel ultrastructure in pigmented hypomaturation amelogenesis imperfecta.

    PubMed

    Wright, J T; Lord, V; Robinson, C; Shore, R

    1992-10-01

    Hypomaturation amelogenesis imperfecta (AI) is a hereditary condition of enamel that is presumed to result from defects during the maturation stage of enamel development. This study characterized the enamel ultrastructure and enamel crystallite morphology, as well as the distribution of organic material in enamel affected with pigmented hypomaturation AI. Enamel exhibiting autosomal recessive pigmented hypomaturation AI was sectioned or fractured and examined using light microscopy, scanning electron microscopy and transmission electron microscopy. Enamel samples were treated with 30% NaOCl or 8 M urea to remove organic components and determine the effect of deproteinization on crystallite morphology. These were compared with untreated normal enamel samples. The enamel crystallites in hypomaturation AI exhibited considerable variability in size and morphology. Examination of deproteinized tissue indicated that the AI crystallites had a thick coating, presumably of organic or partially mineralized material, which was not visible in normal enamel. The results of this investigation provide further evidence that hypomaturation AI is associated with the retention of organic material that is most probably enamel protein. Enamel protein retention is likely to be involved in the inhibition of normal crystallite growth resulting in the morphological crystallite abnormalities associated with this disorder.

  10. Construction of artificial pigment-protein antennae

    SciTech Connect

    Sibbald, JeNell

    1997-01-10

    Photosynthesis is a complex process which results in the conversion of solar radiation into chemical energy. This chemical energy is then used as the free energy source for all living organisms. In its basic form, photosynthesis can be described as the light-activated synthesis of carbohydrates from the simple molecules of water and carbon dioxide: 6H2O + 6 CO2 light C6H12O6 + 6 O2 This basic mechanism actually requires numerous reaction steps. The two primary steps being: the capture of light by pigment molecules in light-harvesting antenna complexes and the transfer of this captured energy to the so-called photochemical reaction center. While the preferred pathway for energy absorbed by the chromophores in the antenna complexes is transfer to the reaction center, energy can be lost to competing processes such as internal conversion or radiative decay. Therefore, the energy transfer must be rapid, typically on the order of picoseconds, to successfully compete. The focus of the present work is on the construction of light-harvesting antenna complexes incorporating modular pigment-proteins.

  11. Chlorophyll and carotenoid pigments of prochloron (prochlorophyta)

    NASA Technical Reports Server (NTRS)

    Paerl, H. W.; Lewin, R. A.; Cheng, L.

    1983-01-01

    High-performance liquid chromatography (HPLC) with a gradient-elution technique was utilized to separate and quantify chlorophylls a and b as well as major carotenoid pigments present in freeze-dried preprations of prochloron-didemnid associations and in Prochloron cells separated from host colonies. Results confirm earlier spectrophotometric evidence for both chlorophylls a and b in this prokaryote. Chlorophyll a:b ratios range from 4.14 to 19.71; generally good agreement was found between ratios determined in isolated cell preprations and in symbiotic colonies (in hospite). These values are 1.5 to 5-fold higher than ratios determined in a variety of eukaryotic green plants. The carotenoids in Prochloron are quantitatively and qualitatively similar to those found in various freshwater and marine blue-green algae (cyanopbytes) from high-light environments. However, Prochloron differs from cyanophytes by the absence of myxoxanthophyll and related glycosidic carotenoids. It pigment characteristics are considered sufficiently different from those of cyanophytes to justify its assignment to a separate algal division.

  12. Human skin pigmentation, migration and disease susceptibility

    PubMed Central

    Jablonski, Nina G.; Chaplin, George

    2012-01-01

    Human skin pigmentation evolved as a compromise between the conflicting physiological demands of protection against the deleterious effects of ultraviolet radiation (UVR) and photosynthesis of UVB-dependent vitamin D3. Living under high UVR near the equator, ancestral Homo sapiens had skin rich in protective eumelanin. Dispersals outside of the tropics were associated with positive selection for depigmentation to maximize cutaneous biosynthesis of pre-vitamin D3 under low and highly seasonal UVB conditions. In recent centuries, migrations and high-speed transportation have brought many people into UVR regimes different from those experienced by their ancestors and, accordingly, exposed them to new disease risks. These have been increased by urbanization and changes in diet and lifestyle. Three examples—nutritional rickets, multiple sclerosis (MS) and cutaneous malignant melanoma (CMM)—are chosen to illustrate the serious health effects of mismatches between skin pigmentation and UVR. The aetiology of MS in particular provides insight into complex and contingent interactions of genetic and environmental factors necessary to trigger lethal disease states. Low UVB levels and vitamin D deficiencies produced by changes in location and lifestyle pose some of the most serious disease risks of the twenty-first century. PMID:22312045

  13. Bile pigments in pulmonary and vascular disease.

    PubMed

    Ryter, Stefan W

    2012-01-01

    The bile pigments, biliverdin, and bilirubin, are endogenously derived substances generated during enzymatic heme degradation. These compounds have been shown to act as chemical antioxidants in vitro. Bilirubin formed in tissues circulates in the serum, prior to undergoing hepatic conjugation and biliary excretion. The excess production of bilirubin has been associated with neurotoxicity, in particular to the newborn. Nevertheless, clinical evidence suggests that mild states of hyperbilirubinemia may be beneficial in protecting against cardiovascular disease in adults. Pharmacological application of either bilirubin and/or its biological precursor biliverdin, can provide therapeutic benefit in several animal models of cardiovascular and pulmonary disease. Furthermore, biliverdin and bilirubin can confer protection against ischemia/reperfusion injury and graft rejection secondary to organ transplantation in animal models. Several possible mechanisms for these effects have been proposed, including direct antioxidant and scavenging effects, and modulation of signaling pathways regulating inflammation, apoptosis, cell proliferation, and immune responses. The practicality and therapeutic-effectiveness of bile pigment application to humans remains unclear.

  14. Fruit flesh betacyanin pigments in hylocereus cacti.

    PubMed

    Wybraniec, Sławomir; Mizrahi, Yosef

    2002-10-09

    Determination of profiles and total contents of betacyanins in cactus fruits of Hylocereus species using chromatographic and spectrophotometric method is described. The investigated species were H. polyrhizus, H. purpusii, H. costaricensis, H. sp. 487 (all red-flesh species and hybrids made among them), and the white- or red-flesh species H. undatus. Hybrids included hybrid 1 (H. undatus white-flesh clone and H. sp. 487), hybrid 35 (H. sp. 487 and H. polyrhizus), and the reciprocal hybrid hybrid 95 (H. polyrhizus and H. sp. 487). Fruits of H. polyrhizus exhibited the highest relative concentration (expressed as percentage of the total HPLC peak area) of hylocerenin, a recently discovered pigment, and a high relative concentration of phyllocactin. Hylocerenin and isohylocerenin, present in fruits at relative concentrations of 11.7 and 5.8%, respectively, are probably responsible for the fluorescent color of the fruit pulp. H. costaricensis fruits have a much higher content of phyllocactin (63.9%), which is almost 4 times higher than the betanin content. These differences in pigment concentrations might explain the differences in red hues of the flesh of these fruits.

  15. 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

  16. Effects of long-term atorvastatin treatment on cardiac aging

    PubMed Central

    HAN, LEI; LI, MINGGAO; LIU, XIN

    2013-01-01

    A number of studies have reported that atorvastatin (AVT) may have an important role in the delay of cardiac aging. However, the mechanism by which AVT affects cardiac aging has not been established. In this study, a series of experiments were performed to investigate the effects of AVT treatment on the cardiovascular system and the associated mechanism. Wistar rats were administered AVT or saline for 4 months. Age-related changes in the hearts were measured at the end of the experiment. The results showed that compared with young rats, the aged rats had significant changes indicative of myocardial aging, including increased blood lipid 1evelss, increased body weight, cardiac hypertrophy, larger myocardial cells, irregular muscle fibers, fewer deeply stained nuclei, smaller intercellular spaces, a larger number of apoptotic cells and increased levels of lipofuscin in myocardial tissue. However, long-term AVT treatment was able to significantly delay or even reverse these aging-related changes. In addition, these effects showed a certain dose-dependence. In general, long-term AVT treatment reduces blood lipids, inhibits cardiac hypertrophy, suppresses cardiomyocyte apoptosis and lowers the level of oxidative stress to protect the heart from aging. PMID:24137254

  17. The blue of iron in mineral pigments: a Fe K-edge XANES study of vivianite

    NASA Astrophysics Data System (ADS)

    Figueiredo, M. O.; Silva, T. P.; Veiga, J. P.

    2010-05-01

    Iron is a powerful chromophore element whose pigmenting properties were the first to be recognized among transition metals. The interest in blue iron minerals as pigments for painting was enhanced with the use of vivianite—a natural hydrated ferrous phosphate, Fe3(PO4)2ṡ8H2O—which in medieval Europe became an alternative to the expensive lapis lazuli, (Na, Ca)4(AlSiO4)3(SO4, Cl, S), a member of the ultramarines whose appreciated blue tone is due to the presence of sulfur polyanions. Conversely, vivianite coloring is attributed to the intervalence charge transfer (IVCT) Fe2+-Fe3+ that in later decades was studied by optical techniques and Mössbauer spectroscopy. However, the aging of blue vivianite pigments in old paintings has become a serious concern for conservators, but the aging process still awaits a satisfactory explanation. As an input to this problem, an X-ray absorption near-edge structure (XANES) study at the Fe K-edge of vivianite with different colors and origins was undertaken at the European Synchrotron Radiation Facility using the instrumental facilities of beamline ID-21. The analysis of pre-edge features corroborates previous data on the origin of vivianite color and emphasizes the need for a precautious assessment of iron speciation on the exclusive basis of XANES data. Actual results are discussed and further work is outlined.

  18. Comparison of marine algae (Spirulina platensis) and synthetic pigment in enhancing egg yolk colour of laying hens.

    PubMed

    Zahroojian, N; Moravej, H; Shivazad, M

    2011-10-01

    The objective of this experiment was to determine the effects of dietary marine algae (Spirulina platensis) on egg yolk colour, and compare the effectiveness of Spirulina and synthetic pigment in enhancing egg yolk colour of laying hens fed on a wheat-based diet. In total, 160 Hy-line W36 laying hens of 63 weeks of age were studied by dividing them into 5 groups, 32 birds in each. Except for the control group (based on wheat and soyabean meal), the feed for three other groups contained 1·5, 2·0 and 2·5% of Spirulina; while one group contained synthetic pigments (BASF Lucantin® yellow: 30 mg/kg, and BASF Lucantin® red: 35 mg/kg). Egg production, feed intake, feed conversion ratio (FCR), egg weight and egg yolk colour were determined. A significant increase in egg yolk colour was observed in the treatments that received the Spirulina and synthetic pigment, compared with the control diet. There were no significant differences between the treatments with 2·5% Spirulina and synthetic pigment in enhancing egg yolk colour. Finally, the results indicated that the diet containing 2·5% Spirulina could be as effective as the diet with synthetic pigment in producing an agreeable egg yolk colour.

  19. Newly emerged nulliparous Culicoides imicola Kieffer (Diptera: Ceratopogonidae) with pigmented abdomen.

    PubMed

    Braverman, Yehuda; Mumcuoglu, Kosta

    2009-03-23

    The method of segregating nulliparous and parous females of Culicoides spp. based on the presence of burgundy-red pigment inside the abdominal wall of parous Culicoides midges, is used worldwide. Out of 320 females of Culicoides imicola trapped by emergence traps, set over an artificial breeding site for 10 and 24 days, 73 (22.8%) showed a red-pigmentation despite the fact that they were nulliparous. This finding indicated that 23% of the "parous" females that are examined for the presence of arboviruses and other pathogens or for age-grading purposes, are actually old nulliparous females, which had no chance of acquiring pathogens. This bias in parous rate distorts upward the calculation of vectorial capacity.

  20. Was skin cancer a selective force for black pigmentation in early hominin evolution?

    PubMed

    Greaves, Mel

    2014-04-22

    Melanin provides a crucial filter for solar UV radiation and its genetically determined variation influences both skin pigmentation and risk of cancer. Genetic evidence suggests that the acquisition of a highly stable melanocortin 1 receptor allele promoting black pigmentation arose around the time of savannah colonization by hominins at some 1-2 Ma. The adaptive significance of dark skin is generally believed to be protection from UV damage but the pathologies that might have had a deleterious impact on survival and/or reproductive fitness, though much debated, are uncertain. Here, I suggest that data on age-associated cancer incidence and lethality in albinos living at low latitudes in both Africa and Central America support the contention that skin cancer could have provided a potent selective force for the emergence of black skin in early hominins.

  1. Was skin cancer a selective force for black pigmentation in early hominin evolution?

    PubMed Central

    Greaves, Mel

    2014-01-01

    Melanin provides a crucial filter for solar UV radiation and its genetically determined variation influences both skin pigmentation and risk of cancer. Genetic evidence suggests that the acquisition of a highly stable melanocortin 1 receptor allele promoting black pigmentation arose around the time of savannah colonization by hominins at some 1–2 Ma. The adaptive significance of dark skin is generally believed to be protection from UV damage but the pathologies that might have had a deleterious impact on survival and/or reproductive fitness, though much debated, are uncertain. Here, I suggest that data on age-associated cancer incidence and lethality in albinos living at low latitudes in both Africa and Central America support the contention that skin cancer could have provided a potent selective force for the emergence of black skin in early hominins. PMID:24573849

  2. 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.

  3. [Synthesis of melanin pigments by Antarctic black yeast].

    PubMed

    Tashirev, A B; Romanovskaia, V A; Rokitko, P V; Matveeva, N A; Shilin, S O; Tashireva, A A

    2012-01-01

    Five strains of the black yeast similar to Exophiala nigra (Nadsoniela nigra), which we have isolated from the Antarctic biotopes, are studied. At cultivation in a periodic operation the maximum level of absolutely dry biomass in five tested strains constituted 3.2-7.8 g/l of medium, melanin pigment yield being 6-9% of absolutely dry mass of cells. Two highly productive strains have been selected. Pigments of the studied black yeast are water-insoluble, however dissolve in alkali and concentrated acids. The maximum absorption of the yeast pigments was in the range of 220 nm. The above-stated properties of pigments of the investigated yeast correspond to the description of melanin fractions of Nadsoniela nigra and some microscopic mushrooms. The water-soluble melanin-pigments have been obtained after the dialysis of alkaline solution of the pigment. UV-spectra and visible absorption spectra of water solution of melanin-pigments are almost identical to those of initial alkaline solutions. It is shown that the studied yeast are resistant to high concentrations of toxic metals (Hg2+, Cu2+, Co2+, Cr(VI) and Ni2+), and introduction of Co2+ into the cultivation medium leads to the increase of pigments synthesis.

  4. Internal pigment cells respond to external UV radiation in frogs.

    PubMed

    Franco-Belussi, Lilian; Nilsson Sköld, Helen; de Oliveira, Classius

    2016-05-01

    Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not well known. Here, we tested genotoxic effects of UVR and its effects on internal pigmentation in a neotropical frog, Physalaemus nattereri We found increases in body darkness and internal melanin pigmentation in testes and heart surfaces and in the mesenterium and lumbar region after just a few hours of UVR exposure. The melanin dispersion in melanomacrophages in the liver and melanocytes in testes increased after UV exposure. In addition, the amount of melanin inside melanomacrophages cells also increased. Although mast cells were quickly activated by UVR, only longer UVR exposure resulted in genotoxic effects inside frogs, by increasing the frequency of micronuclei in red blood cells. This is the first study to describe systemic responses of external UVR on internal melanin pigmentation, melanomacrophages and melanocytes in frogs and thus provides a functional explanation to the presence of internal pigmentation.

  5. Pigment Production by Streptococcus agalactiae in Quasi-Defined Media

    PubMed Central

    Rosa-Fraile, Manuel; Sampedro, Antonio; Rodríguez-Granger, Javier; García-Peña, Maria Luisa; Ruiz-Bravo, Alfonso; Haïdour, Ali

    2001-01-01

    A quasi-defined medium that supports the growth of Streptococcus agalactiae as pigmented colonies has been developed. The medium contains starch, a peptic digest of albumin, amino acids, nucleosides, vitamins, and salts. The presence of free cysteine, which could be replaced with other sulphur-containing compounds and to a lesser degree by reducing agents, was required for pigment formation. PMID:11133484

  6. A green process to prepare chromic oxide green pigment.

    PubMed

    Li, Ping; Xu, Hong-Bin; Zheng, Shi-Li; Zhang, Yi; Li, Zuo-Hu; Bai, Yu-Lan

    2008-10-01

    A hydrogen reduction and activated sintering process was proposed to prepare chromic oxide green pigment. Through ICP, XRD, SEM, FT-IR, UV, and CIE-L*a*b* colorimetric analysis, key factors and mechanism that influenced preparation of chromic oxide green pigment were studied. The results revealed that lower hydrogen reduction temperature, suitable addition of Al and Ba, were beneficial to obtaining the high quality chromic oxide green pigment. Typically, when the hydrogen reduction temperature was kept at 450-500 degrees C, physicochemical properties and color performance of the prepared chromic oxide green pigment doped with about 0.1-0.2 wt % Al and 0.2-0.5 wt % Ba conformed to commercial pigment standards. Additionally, characteristics of the green process were discussed. About 90 wt % KOH was reused directly and about 90 wt % Cr(VI) was conversed to Cr(III) directly from potassium chromate to chromic oxide green pigment. Integrating the proprietary green metallurgical process from chromite ore to potassium chromate of this laboratory, more than 99 wt % Cr(VI) could be conversed to Cr(III) compounds and about 99 wt % KOH could be recycled to use. The whole green process, ranging from chromite ore to chromic oxide green pigment, eventually not only provided the possibility for producing the high quality chromic oxide green pigment, but could reach comprehensive utilization of resources, inner recycle of KOH, and zero emission of Cr(VI).

  7. Pigmented mammary paget disease misdiagnosed as malignant melanoma.

    PubMed

    Lee, Ji Hye; Kim, Tae Hyung; Kim, Soo-Chan; Kim, You Chan; Roh, Mi Ryung

    2014-12-01

    Pigmented mammary Paget disease is a very rare clinicopathologic variant of mammary Paget disease. Diagnosis is often difficult because its clinical and histological features are very similar to those of malignant melanoma. Herein, we report a case of pigmented mammary Paget disease misdiagnosed as malignant melanoma.

  8. Passivation of pigment particles for thermal control coatings

    NASA Technical Reports Server (NTRS)

    Sancier, K. M.; Morrison, S. R.; Farley, E. P.

    1975-01-01

    The preparation of a matrix of 48 samples consisting of pigments and pigmented paints is described. The results obtained from testing these samples by electron spin resonance and by in situ spectral reflectance measurements in space simulation tests are presented. Conclusions and recommendations for further research are given.

  9. Stabilized pigment and method for producing the same

    NASA Technical Reports Server (NTRS)

    Morrison, Stanley Roy (Inventor); Freund, Thomas (Inventor)

    1976-01-01

    A chemical species, present in two oxidation states which differ from one another by one equivalent, is added to pigment materials to serve as a recombination center for alternately capturing electrons and holes produced by the pigment materials when they are subjected to ultraviolet light exposure.

  10. Passivation of pigment particles for thermal control coatings

    NASA Technical Reports Server (NTRS)

    Sancier, K. M.; Morrison, S. R.; Farley, E. P.

    1974-01-01

    Various redox couple surface additives are studied which increase the photostability of coprecipitated zinc orthotitanate pigment. The electron spin resonance technique was used to examine the characteristic photodamage centers. Results indicate that cerium surface redox additive completely passivates the pigment at the surface concentrations studied. Less passivation occurs with the iridium chloride and the iron cyanide redox couples.

  11. Changes in pigment, spectral transmission and element content of pink chicken eggshells with different pigment intensity during incubation.

    PubMed

    Yu, Yue; Li, Zhanming; Pan, Jinming

    2016-01-01

    Objective. The objective of this study was to investigate changes in pigment, spectral transmission and element content of chicken eggshells with different intensities of pink pigment during the incubation period. We also investigated the effects of the region (small pole, equator and large pole) and pink pigment intensity of the chicken eggshell on the percent transmission of light passing through the chicken eggshells. Method. Eggs of comparable weight from a meat-type breeder (Meihuang) were used, and divided based on three levels of pink pigment (light, medium and dark) in the eggshells. During the incubation (0-21 d), the values of the eggshell pigment (ΔE, L (∗), a (∗), b (∗)) were measured. The percent transmission of light for different regions and intensities of eggshell pigmentation was measured by using the visible wavelength range of 380-780 nm. Result. Three measured indicators of eggshell color, ΔE, L (∗) and a (∗), did not change significantly during incubation. Compared with other regions and pigment intensities, eggshell at the small pole and with light pigmentation intensity showed the highest percent transmission of light. The transmission value varied significantly (P < 0.001) with incubation time. The element analysis of eggshells with different levels of pink pigment showed that the potassium content of the eggshells for all pigment levels decreased significantly during incubation. Conclusion. In summary, pigment intensity and the region of the eggshell influenced the percent transmission of light of eggshell. Differences in the spectral characteristics of different eggshells may influence the effects of photostimulation during the incubation of eggs. All of these results will be applicable for perfecting the design of light intensity for lighted incubation to improve productivity.

  12. Age-related changes in ultrastructural features of cathepsin B- and D-containing neurons in rat cerebral cortex.

    PubMed

    Jung, H; Lee, E Y; Lee, S I

    1999-10-09

    The present study examines age-related changes in the subcellular localization of cathepsin B (cath B) and cathepsin D (cath D), as well as morphological features of the cathepsin-immunoreactive (ir) neurons in rat cerebral cortex. Sprague-Dawley rats were studied at 3 and 26 months. By immunoelectron microscopy cath B- or cath D-immunoreactivities were found in many, but not all, pyramidal neurons. In young rat cerebral cortical neurons, cath B was observed not only in lysosomal systems such as multivesicular bodies, dense bodies, and lipofuscin granules, but also in extralysosomal sites. By contrast, cath D was confined mainly to lysosomal systems in young rats. In aged rats, cath B showed a similar pattern in its subcellular localization compared to the young control, but some of the dense bodies containing cath B was closely apposed to the outer nuclear envelope. These cells exhibited a relatively normal appearance. Regardless of subcellular localization, approximately 10% of cath B-ir neurons displayed ultrastructural disturbances presumed to indicate an early stage of degeneration. The nucleus was indented, nuclear boundary was indistinct, nuclear pore structures appeared separately with high frequency, and the endoplasmic reticulum appeared to be affected. In addition to its presence in lysosomal structures, cath D-immunoreactivity in aged cerebral cortex was noted prominently in the cytosol as diffuse granules. About 37% of cath D-ir cells showed this age-related change. Among the neurons with the diffusely scattered form of cath D, approximately 70% of cells exhibited the degenerating features. These cells were characterized by large amounts of diffuse cath D, reduced cellular size, loss of the nuclear boundary, scattered nuclear pore structures, an often fragmentation of the nucleus, disturbances of endoplasmic reticular system, and in advanced stages, condensed nucleus and poor preservation of almost cytoplasmic organelles. Though some of these features

  13. Thermohaline Circulation Variability Preserved by Estuarine Fossil Pigments

    NASA Astrophysics Data System (ADS)

    Hubeny, J. B.

    2005-12-01

    Fluctuations in deep water formation and thermohaline circulation (THC) are associated with changes in the meridional heat flux associated with the Gulf Stream/North Atlantic Current. The associated oceanic meridional heat flux variability is communicated to the atmosphere through sensible and latent heat fluxes. Therefore, we expect to observe changes in atmospheric temperature along this oceanic surface current route at periodicities dictated by thermohaline dynamics. A limiting piece to this equation, however, has been the short duration of instrumental records and the resulting deficiency in resolving low-frequency THC cycles. In order to address this barrier, we have generated a paleoproxy record of photosynthetic pigments from the Pettaquamscutt River Estuary, Rhode Island, USA. These pigments are produced by phototrophic bacteria that reside at the pycnocline and whose productivity is forced by water column temperature. The water column temperature is in turn forced by atmospheric temperature, which we propose is partially forced by changes in meridional heat flux associated with THC fluctuations. In our time series, we have identified two significant periodicities that have been identified as being associated with thermohaline circulation in modeling studies: the North Atlantic Interdecadal Mode (NAIM; Timmermann, et al., 1998) and the Atlantic Multidecadal Oscillation (AMO; Vellinga and Wu, 2004). In the defining climate models high-latitude processes drive the NAIM, while low-latitude processes drive the AMO. Over the course of our millennial record, we see fundamental reorganization of these two components, suggesting changes in the behavior of THC over the Medieval Warm Period - Little Ice Age - Present Warm Period transitions. Specifically, during the Little Ice Age (LIA), the NAIM periodicity diminishes, and the AMO becomes the dominant low-frequency component in our record. This is most likely due to changes in high-latitude water masses during the

  14. Dermoscopic and Clinical Features of Pigmented Skin Lesions of the Genital Area*

    PubMed Central

    Cengiz, Fatma Pelin; Emiroglu, Nazan; Wellenhof, Rainer Hofmann

    2015-01-01

    BACKGROUND The dermoscopic features of vulvar melanosis lesions are well known. To our knowledge, there are only a few case reports about dermoscopic features of pigmented genital lesions in male patients. OBJECTIVE To evaluate dermoscopic and clinical characteristics of benign lesions of the genital area in both males and females, and to assess the distinguishing dermoscopic criteria of vulvar melanosis and atypical melanocytic nevi of the genital type. METHODS 68 patients with pigmented genital lesions were included in this observational study (28 male and 40 female). A punch biopsy was taken from all pigmented lesions and histopathological examination was performed on all specimens. RESULTS We histopathologically diagnosed: genital melanosis in 40 lesions, atypical melanocytic nevi of the genital type in 15 lesions, melanocytic nevi in 9 lesions, seborrheic keratosis in 4 lesions. The most frequent locations were the glans penis (19 patients, 67.9%) in males and the labia minora (19 patients, 47.5%) in females. The mean age of patients with atypical nevi (28,6 ± 11,36) was significantly lower than the mean age of patients with genital melanosis (47,07 ± 15,33). CONCLUSIONS Parallel pattern is prominent in genital melanosis, ring-like pattern is only observed in genital melanosis. Most pigmented lesions on the genital area are solitary. Blue-white veil and irregular dots are only observed in AMNGT. According to these results, we propose that histopathological examination is performed, especially if blue-white veil and irregular dots are found by dermoscopy. PMID:25830986

  15. Sexual Dimorphism in Melanin Pigmentation, Feather Coloration and Its Heritability in the Barn Swallow (Hirundo rustica)

    PubMed Central

    Saino, Nicola; Romano, Maria; Rubolini, Diego; Teplitsky, Celine; Ambrosini, Roberto; Caprioli, Manuela; Canova, Luca; Wakamatsu, Kazumasa

    2013-01-01

    Melanin is the main pigment in animal coloration and considerable variation in the concentrations of the two melanin forms (pheo- and eumlanin) in pigmented tissues exists among populations and individuals. Melanin-based coloration is receiving increasing attention particularly in socio-sexual communication contexts because the melanocortin system has been hypothesized to provide a mechanistic basis for covariation between coloration and fitness traits. However, with few notable exceptions, little detailed information is available on inter-individual and inter-population variation in melanin pigmentation and on its environmental, genetic and ontogenetic components. Here, we investigate melanin-based coloration in an Italian population of a passerine bird, the barn swallow (Hirundo rustica rustica), its sex- and age-related variation, and heritability. The concentrations of eu- and pheomelanin in the throat (brown) and belly (white-to-brownish) feathers differed between sexes but not according to age. The relative concentration of either melanin (Pheo:Eu) differed between sexes in throat but not in belly feathers, and the concentrations in males compared to females were larger in belly than in throat feathers. There were weak correlations between the concentrations of melanins within as well as among plumage regions. Coloration of belly feathers was predicted by the concentration of both melanins whereas coloration of throat feathers was only predicted by pheomelanin in females. In addition, Pheo:Eu predicted coloration of throat feathers in females and that of belly feathers in males. Finally, we found high heritability of color of throat feathers. Melanization was found to differ from that recorded in Hirundo rustica rustica from Scotland or from H. r. erythrogaster from North America. Hence, present results show that pigmentation strategies vary in a complex manner according to sex and plumage region, and also among geographical populations, potentially

  16. Sexual dimorphism in melanin pigmentation, feather coloration and its heritability in the barn swallow (Hirundo rustica).

    PubMed

    Saino, Nicola; Romano, Maria; Rubolini, Diego; Teplitsky, Celine; Ambrosini, Roberto; Caprioli, Manuela; Canova, Luca; Wakamatsu, Kazumasa

    2013-01-01

    Melanin is the main pigment in animal coloration and considerable variation in the concentrations of the two melanin forms (pheo- and eumlanin) in pigmented tissues exists among populations and individuals. Melanin-based coloration is receiving increasing attention particularly in socio-sexual communication contexts because the melanocortin system has been hypothesized to provide a mechanistic basis for covariation between coloration and fitness traits. However, with few notable exceptions, little detailed information is available on inter-individual and inter-population variation in melanin pigmentation and on its environmental, genetic and ontogenetic components. Here, we investigate melanin-based coloration in an Italian population of a passerine bird, the barn swallow (Hirundo rustica rustica), its sex- and age-related variation, and heritability. The concentrations of eu- and pheomelanin in the throat (brown) and belly (white-to-brownish) feathers differed between sexes but not according to age. The relative concentration of either melanin (Pheo:Eu) differed between sexes in throat but not in belly feathers, and the concentrations in males compared to females were larger in belly than in throat feathers. There were weak correlations between the concentrations of melanins within as well as among plumage regions. Coloration of belly feathers was predicted by the concentration of both melanins whereas coloration of throat feathers was only predicted by pheomelanin in females. In addition, Pheo:Eu predicted coloration of throat feathers in females and that of belly feathers in males. Finally, we found high heritability of color of throat feathers. Melanization was found to differ from that recorded in Hirundo rustica rustica from Scotland or from H. r. erythrogaster from North America. Hence, present results show that pigmentation strategies vary in a complex manner according to sex and plumage region, and also among geographical populations, potentially

  17. Optimization and design of pigments for heat-insulating coatings

    NASA Astrophysics Data System (ADS)

    Wang, Guang-Hai; Zhang, Yue

    2010-12-01

    This paper reports that heat insulating property of infrared reflective coatings is obtained through the use of pigments which diffuse near-infrared thermal radiation. Suitable structure and size distribution of pigments would attain maximum diffuse infrared radiation and reduce the pigment volume concentration required. The optimum structure and size range of pigments for reflective infrared coatings are studied by using Kubelka—Munk theory, Mie model and independent scattering approximation. Taking titania particle as the pigment embedded in an inorganic coating, the computational results show that core-shell particles present excellent scattering ability, more so than solid and hollow spherical particles. The optimum radius range of core-shell particles is around 0.3 ~ 1.6 μm. Furthermore, the influence of shell thickness on optical parameters of the coating is also obvious and the optimal thickness of shell is 100-300 nm.

  18. Fly ash based zeolitic pigments for application in anticorrosive paints

    NASA Astrophysics Data System (ADS)

    Shaw, Ruchi; Tiwari, Sangeeta

    2016-04-01

    The purpose of this work is to evaluate the utilization of waste fly ash in anticorrosive paints. Zeolite NaY was synthesized from waste fly ash and subsequently modified by exchanging its nominal cation Na+ with Mg2+ and Ca2+ ions. The metal ion exchanged zeolite was then used as anticorrosive zeolitic pigments in paints. The prepared zeolite NaY was characterized using X-Ray diffraction technique and Scanning electron microscopy. The size, shape and density of the prepared fly ash based pigments were determined by various techniques. The paints were prepared by using fly ash based zeolitic pigments in epoxy resin and the percentages of pigments used in paints were 2% and 5%. These paints were applied to the mild steel panels and the anticorrosive properties of the pigments were assessed by the electrochemical spectroscopy technique (EIS).

  19. 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

  20. Structural and functional characterization of enamel pigmentation in shrews.

    PubMed

    Dumont, M; Tütken, T; Kostka, A; Duarte, M J; Borodin, S

    2014-04-01

    Pigmented tooth enamel occurs in several vertebrate clades, ranging from mammals to fish. Although an iron compound is associated with this orange to red colored pigmentation, its chemical and structural organization within the enamel is unknown. To determine the nature of the iron compound, we investigated heavily pigmented teeth of the northern short-tailed shrew Blarina brevicauda using combined characterization techniques such as scanning and transmission electron microscopy and synchrotron X-ray diffraction. We found that the pigmentation of the enamel with an iron content of around 8wt% results from a close to amorphous magnetite phase deposited around the nm-sized enamel crystals. Furthermore, the influence of the pigmentation on the enamel hardness was determined by nanoindentation measurements. Finally, the biomechanical function and biological context are discussed in light of the obtained results.

  1. Relation Between Changes in Pigments' Spectral Properties and Structural Distortions of Pigment Protein Complexes (abstract)

    NASA Astrophysics Data System (ADS)

    Stoitchkova, Katerina; Andreeva, Atanaska; Busheva, Mira

    2009-04-01

    Scientists continue to investigate photosynthesis-nature's process to efficiently regulate and store energy. To explore the mechanisms of regulation we used fluorescence, resonance Raman spectroscopy, and biochemical preparative methods. For detailed analysis we applied decomposition of the low temperature steady-state fluorescence spectra. This allowed us to estimate the emission of distinct pigment protein complexes (PPC) and evaluate the fluorescence of various aggregation forms of the main light harvesting complex (LHCII), which plays a major role in the studied mechanisms. Resonance Raman spectroscopy revealed with precision the relation between changes in pigments' spectral properties and structural distortions of PPC. It was shown that aggregation of LHCII led to out-of-plane distortion, not only of neoxanthin, but also of lutein molecules. This was enhanced when the complex was embedded in thylakoid membranes (TM). It was suggested that lutein molecules are more closely related to the process of aggregation of LHCII in TM than neoxanthin.

  2. The other pigment cell: specification and development of the pigmented epithelium of the vertebrate eye

    PubMed Central

    Bharti, Kapil; Nguyen, Minh-Thanh T.; Skuntz, Susan; Bertuzzi, Stefano; Arnheiter, Heinz

    2006-01-01

    Summary Vertebrate retinal pigment epithelium (RPE) cells are derived from the multipotent optic neuroepithelium, develop in close proximity to the retina, and are indispensible for eye organogenesis and vision. Recent advances in our understanding of RPE development provide evidence for how critical signaling factors operating in dorso-ventral and distal-proximal gradients interact with key transcription factors to specify three distinct domains in the budding optic neuroepithelium: the distal future retina, the proximal future optic stalk/optic nerve, and the dorsal future RPE. Concomitantly with domain specification, the eye primordium progresses from a vesicle to a cup, RPE pigmentation extends towards the ventral side, and the future ciliary body and iris form from the margin zone between RPE and retina. While much has been learned about the molecular networks controlling RPE cell specification, key questions concerning the cell proliferative parameters in RPE and the subsequent morphogenetic events still need to be addressed in greater detail. PMID:16965267

  3. Preferential interactions in pigmented, polymer blends - C.I. Pigment Blue 15:4 and C.I. Pigment Red 122 - as used in a poly(carbonate)-poly(butylene terephthalate) polymer blend.

    PubMed

    Fagelman, K E; Guthrie, J T

    2005-11-18

    Some important characteristics of selected pigments have been evaluated, using the inverse gas chromatography (IGC) technique, that indicate the occurrence of preferential interactions in pigmented polymer blends. Attention has been given to copper phthalocyanine pigments and to quinacridone pigments incorporated in polycarbonate-poly(butylene terephthalate) blends. Selected supporting techniques were used to provide supplementary information concerning the pigments of interest, C.I. Pigment Blue 15:4 and C.I. Pigment Red 122. For C.I. Pigment Red 122 and for C.I. Pigment Blue, the dispersive component of the surface free energy decreases as the temperature increases, indicating the relative ease with which the molecules can be removed from the surface.

  4. The influence of abdominal pigmentation on desiccation and ultraviolet resistance in two species of Drosophila.

    PubMed

    Matute, Daniel R; Harris, Alexandra

    2013-08-01

    Drosophila yakuba and D. santomea are sister species that differ in their levels of abdominal pigmentation; D. yakuba shows heavily pigmented posterior abdominal segments in both sexes, whereas D. santomea lacks dark pigment anywhere on its body. Using naturally collected lines, we demonstrate the existence of altitudinal variation in abdominal pigmentation in D. yakuba but not in D. santomea. We use the variation in pigmentation within D. yakuba and two body-color mutants in D. yakuba to elucidate selective advantage of differences in pigmentation. Our results indicate that although differences in abdominal pigmentation have no effect on desiccation resistance, lighter pigmentation confers ultraviolet radiation resistance in this pair of species.

  5. Idiopathic eruptive macular pigmentation with papillomatosis

    PubMed Central

    Verma, Shikha; Thakur, Binod Kumar

    2011-01-01

    We present a case of an otherwise healthy 10-year-old girl who presented with asymptomatic brown macules over the trunk and proximal extremities, of three months’ duration. The cutaneous examination revealed multiple, dark brown, discrete, round to oval macules and a few mildly elevated lesions over the trunk and proximal limbs. The individual lesion was 1-3 cm in diameter and a few showed velvety appearance over the surface. Darier's sign was negative. The histopathological study from the velvety lesion showed acanthosis, papillomatosis and increased melanin in the basal layer. The upper dermis showed sparse perivascular infiltrate of lymphocytes without any dermal melanophages. It fulfilled the criteria for idiopathic eruptive macular pigmentation with additional histological finding of papillomatosis. PMID:23130237

  6. Genetics of pigmentation in dogs and cats.

    PubMed

    Kaelin, Christopher B; Barsh, Gregory S

    2013-01-01

    Color variation in companion animals has long been of interest to the breeding and scientific communities. Simple traits, like black versus brown or yellow versus black, have helped to explain principles of transmission genetics and continue to serve as models for studying gene action and interaction. We present a molecular genetic review of pigmentary variation in dogs and cats using a nomenclature and logical framework established by early leaders in the field. For most loci in which molecular variants have been identified (nine in dogs and seven in cats), homologous mutations exist in laboratory mice and/or humans. Exceptions include the K locus in dogs and the Tabby locus in cats, which give rise to alternating stripes or marks of different color, and which illustrate the continued potential of coat color genetics to provide insight into areas that transcend pigment cell biology.

  7. Radiative Cooling With Pigmented Polyethylene Foils

    NASA Astrophysics Data System (ADS)

    Niklasson, Gunnar A.; Eriksson, Tord S.

    1989-03-01

    Polyethylene foils containing a nonabsorbing pigment can be suitable for radiative cooling because of their high reflectance of solar radiation combined with a high transmittance in the atmospheric window region in the thermal infrared. We have studied the optical properties in the wavelength range 0.3-50 μm of extruded polyethylene foils containing various amounts of 0.23 μm diameter Ti02 particles. It appears that the foils can prevent heating of an underlying material, even when directly illuminated by the sun. The total transmittance and reflectance of the Ti02-polyethylene foils were compared with multiple scattering calculations. Lorenz-Mie theory was used to model the scattering and absorption of a single TiO2 sphere. The single scattering parameters were then introduced into the four flux theory, by which the transmittance and reflectance were calculated. We find a satisfactory agreement between theory and experiments in most cases.

  8. Clinicoepidemiological study of pigmented purpuric dermatoses

    PubMed Central

    Sharma, Lata; Gupta, S.

    2012-01-01

    Background: Pigmented purpuric dermatoses (PPD) are a group of vascular disorders with varied manifestations which cause concern and are resistant to treatment. The literature is still lacking in clinicoepidemiological studies. Aim: To study the epidemiology, etiological, host and environmental factors, clinical manifestations, its variations, and the type prevalent in this part of the world. Materials and Methods: All cases of PPD were selected for the study from Skin and Venereal Disease, Out Patient Department between January 2008 and June 2009. Their history, examination, hematological investigations, and, in a few, histopathology findings were also recorded and data obtained were evaluated statistically. Results: There were 100 cases of PPD of total 55 323 patients (0.18%). There were 79 males and 21 females between 11 and 66 years. They were working as police men, security guards, barber, chemist, teachers, students, farmers, businessmen, and housewives. In a majority, there was a history of prolonged standing in day-to-day work. Purpuric, brownish pigmented, lichenoid or atrophic lesions were seen depending upon the type of PPD on lower parts of one or both lower limbs. Blood investigations were normal. Schamberg's disease was seen in ninety five, Lichen aureus in three, lichenoid dermatosis and Majocchi's disease in one case each. Discussion: Three clinical types of PPD were diagnosed which may represent different features of the same disease. Cell-mediated immunity, immune complexes, capillary fragility, gravitational forces, venous hypertension, focal infection, clothing, contact allergy to dyes, and drug intake have been incriminating factors in the past. Patient's occupation and environmental factors may also be considered contributory in precipitating the disease. Conclusions: The study revealed the problem of PPD in this geographical area, its magnitude, clinical presentation, the type prevalent, and possible aggravating factors to be kept in mind

  9. High biological variability of plastids, photosynthetic pigments and pigment forms of leaf primordia in buds.

    PubMed

    Solymosi, Katalin; Morandi, Dominique; Bóka, Károly; Böddi, Béla; Schoefs, Benoît

    2012-05-01

    To study the formation of the photosynthetic apparatus in nature, the carotenoid and chlorophyllous pigment compositions of differently developed leaf primordia in closed and opening buds of common ash (Fraxinus excelsior L.) and horse chestnut (Aesculus hippocastanum L.) as well as in closed buds of tree of heaven (Ailanthus altissima P. Mill.) were analyzed with HPLC. The native organization of the chlorophyllous pigments was studied using 77 K fluorescence spectroscopy, and plastid ultrastructure was investigated with electron microscopy. Complete etiolation, i.e., accumulation of protochlorophyllide, and absence of chlorophylls occurred in the innermost leaf primordia of common ash buds. The other leaf primordia were partially etiolated in the buds and contained protochlorophyllide (0.5-1 μg g(-1) fresh mass), chlorophyllides (0.2-27 μg g(-1) fresh mass) and chlorophylls (0.9-643 μg g(-1) fresh mass). Etio-chloroplasts with prolamellar bodies and either regular or only low grana were found in leaves having high or low amounts of chlorophyll a and b, respectively. After bud break, etioplast-chloroplast conversion proceeded and the pigment contents increased in the leaves, similarly to the greening processes observed in illuminated etiolated seedlings under laboratory conditions. The pigment contents and the ratio of the different spectral forms had a high biological variability that could be attributed to (i) various light conditions due to light filtering in the buds resulting in differently etiolated leaf primordia, (ii) to differences in the light-exposed and inner regions of the same primordia in opening buds due to various leaf folding, and (iii) to tissue-specific slight variations of plastid ultrastructure.

  10. Functional annotation of the human retinal pigment epithelium transcriptome

    PubMed Central

    Booij, Judith C; van Soest, Simone; Swagemakers, Sigrid MA; Essing, Anke HW; Verkerk, Annemieke JMH; van der Spek, Peter J; Gorgels, Theo GMF; Bergen, Arthur AB

    2009-01-01

    Background To determine level, variability and functional annotation of gene expression of the human retinal pigment epithelium (RPE), the key tissue involved in retinal diseases like age-related macular degeneration and retinitis pigmentosa. Macular RPE cells from six selected healthy human donor eyes (aged 63–78 years) were laser dissected and used for 22k microarray studies (Agilent technologies). Data were analyzed with Rosetta Resolver, the web tool DAVID and Ingenuity software. Results In total, we identified 19,746 array entries with significant expression in the RPE. Gene expression was analyzed according to expression levels, interindividual variability and functionality. A group of highly (n = 2,194) expressed RPE genes showed an overrepresentation of genes of the oxidative phosphorylation, ATP synthesis and ribosome pathways. In the group of moderately expressed genes (n = 8,776) genes of the phosphatidylinositol signaling system and aminosugars metabolism were overrepresented. As expected, the top 10 percent (n = 2,194) of genes with the highest interindividual differences in expression showed functional overrepresentation of the complement cascade, essential in inflammation in age-related macular degeneration, and other signaling pathways. Surprisingly, this same category also includes the genes involved in Bruch's membrane (BM) composition. Among the top 10 percent of genes with low interindividual differences, there was an overrepresentation of genes involved in local glycosaminoglycan turnover. Conclusion Our study expands current knowledge of the RPE transcriptome by assigning new genes, and adding data about expression level and interindividual variation. Functional annotation suggests that the RPE has high levels of protein synthesis, strong energy demands, and is exposed to high levels of oxidative stress and a variable degree of inflammation. Our data sheds new light on the molecular composition of BM, adjacent to the RPE, and is useful for

  11. Comparative short-term inhalation toxicity of five organic diketopyrrolopyrrole pigments and two inorganic iron-oxide-based pigments

    PubMed Central

    Hofmann, Thomas; Ma-Hock, Lan; Strauss, Volker; Treumann, Silke; Rey Moreno, Maria; Neubauer, Nicole; Wohlleben, Wendel; Gröters, Sibylle; Wiench, Karin; Veith, Ulrich; Teubner, Wera; van Ravenzwaay, Bennard; Landsiedel, Robert

    2016-01-01

    Abstract Diketopyrrolopyrroles (DPP) are a relatively new class of organic high-performance pigments. The present inhalation and particle characterization studies were performed to compare the effects of five DPP-based pigments (coarse and fine Pigment Red 254, coarse and fine meta-chloro DPP isomer and one form of mixed chlorinated DPP isomers) and compare it to coarse and fine inorganic Pigment Red 101. Wistar rats were exposed head-nose to atmospheres of the respective materials for 6 h/day on 5 consecutive days. Target concentrations were 30 mg/m3 as high dose for all compounds and selected based occupational exposure limits for respirable nuisance dust. Toxicity was determined after end of exposure and after 3-week recovery using broncho-alveolar lavage fluid (BALF) and microscopic examinations of the entire respiratory tract. Mixed chlorinated DPP isomers and coarse meta-chloro DPP isomer caused marginal changes in BALF, consisting of slight increases of polymorphonuclear neutrophils, and in case of coarse meta-chloro DPP increased MCP-1 and osteopontin levels. Mixed chlorinated DPP isomers, Pigment Red 254, and meta-chloro DPP caused pigment deposits and phagocytosis by alveolar macrophages, slight hypertrophy/hyperplasia of the bronchioles and alveolar ducts, but without evidence of inflammation. In contrast, only pigment deposition and pigment phagocytosis were observed after exposure to Pigment Red 101. All pigments were tolerated well and caused only marginal effects in BALF or no effects at all. Only minor effects were seen on the lung by microscopic examination. There was no evidence of systemic inflammation based on acute-phase protein levels in blood. PMID:27387137

  12. Algal pigments record shifts in dominant primary productivity through the Holocene in an arctic lake

    NASA Astrophysics Data System (ADS)

    Florian, C.; Miller, G. H.; Fogel, M. L.

    2011-12-01

    The character and magnitude of primary productivity in arctic lakes is largely controlled by climate. Organic compounds derived from pigments and preserved in lake sediments allow reconstruction of past abundances of algae that do not leave silicious microfossils. Fossil algal pigments are abundant in lake sediment and can be accurately quantified using High Pressure Liquid Chromatography (HPLC). Several groups of algae produce unique pigments that can be used to reconstruct their past abundance. In Qivitu Highlands Lake, eastern central Baffin Island, the ratio of pigments diatoxantin and lutein exhibits coherent changes through the Holocene. Diatoxanthin is produced by diatoms and chrysophytes, whereas lutein is produced by green algae and higher plants. Because these pigments are the dominant carotenoids in the sediment, they serve as proxies for the dominant group of primary producers. During the Holocene Thermal Maximum and the past century, lutein is much more abundant than diatoxanthin. During Neoglacial cooling and into the Little Ice Age, diatoxanthin becomes the dominant carotenoid. This shift reveals that there was a change in not only the magnitude of algal production, but also the most abundant type. The adaptation of aquatic algal assemblages to changing climate suggests that gross changes in primary productivity may not be suitable to track the abundance of one type of algal microfossil (such as diatoms) without considering the other algal groups. Higher plants also produce lutein, and its abundance is additionally influenced by the presence of terrestrial organic matter as well as aquatic macrophyte plants. We hypothesize that the prevalence of lutein during warm summers is due to a longer ice-free season, allowing the development of a greater biomass of green algae and macrophyte plants as well as possible increases of terrestrial higher plant communities. This is part of a larger study where the lutein to diatoxanthin ratio is compared to organic

  13. LIBS identification of pigments from Aula Leopoldina vault

    NASA Astrophysics Data System (ADS)

    Ostrowski, R.; Skrzeczanowski, W.; Marczak, J.; Sarzynski, A.

    2009-07-01

    Aula Leopoldina is the most representative, baroque hall in Wroclaw University. In 2008, LIBS measurements of paintings layers of Aula vault were done. LIBS spectra permitted identification of mineral pigments used for specific colors of painting layers. This identification could not be unambiguous in each case since simultaneous occurrence of elements that could be components of different pigments of the same color was observed in some samples. For example, in some red samples the presence of aluminum and iron was stated, and hence red ochre or Mars red could be used as a pigment. In other samples the cinnabar can be additionally responsible for red color. Similar problems were observed in case of blue pigments, where existence of copper may show that azurite was used, but the presence of aluminum, sodium, silicon and iron can point to application of ultramarine, Egyptian or Prussian blues. The greatest difficulties occurred during identification of white pigments. Because of presence of barium, zinc, lead and titanium, the potential pigments might be lithopone, barite, zinc white, lead white or titanium white. Final choice of the pigment is determined by the time of last renovation and this points out that the zinc white was used.

  14. Antimycobacterial activity in vitro of pigments isolated from Antarctic bacteria.

    PubMed

    Mojib, Nazia; Philpott, Rachel; Huang, Jonathan P; Niederweis, Michael; Bej, Asim K

    2010-11-01

    In this study, we describe the antimycobacterial activity of two pigments, violacein, a purple violet pigment from Janthinobacterium sp. Ant5-2 (J-PVP), and flexirubin, a yellow-orange pigment from Flavobacterium sp. Ant342 (F-YOP). These pigments were isolated from bacterial strains found in the land-locked freshwater lakes of Schirmacher Oasis, East Antarctica. The minimum inhibitory concentrations (MICs) of these pigments for avirulent and virulent mycobacteria were determined by the microplate Alamar Blue Assay (MABA) and Nitrate Reductase Assay (NRA). Results indicated that the MICs of J-PVP and F-YOP were 8.6 and 3.6 μg/ml for avirulent Mycobacterium smegmatis mc²155; 5 and 2.6 μg/ml for avirulent Mycobacterium tuberculosis mc²6230; and 34.4 and 10.8 μg/ml for virulent M. tuberculosis H₃₇Rv, respectively. J-PVP exhibited a ~15 times lower MIC for Mycobacterium sp. than previously reported for violacein pigment from Chromobacterium violaceum, while the antimycobacterial effect of F-YOP remains undocumented. Our results indicate these pigments isolated from Antarctic bacteria might be valuable lead compounds for new antimycobacterial drugs used for chemotherapy of tuberculosis.

  15. Heart pigmentation in the gray bichir, Polypterus senegalus (Actinopterygii: Polypteriformes).

    PubMed

    Reyes-Moya, I; Torres-Prioris, A; Sans-Coma, V; Fernández, B; Durán, A C

    2015-12-01

    The occurrence of pigment cells in the heart is well documented in amphibians, birds and mammals. By contrast, information on heart pigmentation in fish is extremely sparse. The aim is to report the presence of pigment cells over the entire surface of the heart in the gray bichir, Polypterus senegalus. The sample consisted of 12 hearts, which, after gross anatomical examination, were studied using histochemical and immunohistochemical techniques for light microscopy, and transmission electron microscopy. The pigment cells were located in the subepicardium, showing a regular distribution pattern across the whole heart, except for the anterior end of the outflow tract, where the pigmentation was much more intense. The cells contained dark, ovoid-shaped organelles which was consistent with a melanosome cell identity. As in other vertebrates, the physiological role of the pigment cells in the heart of the gray bichir is unknown. The absence of such cells in hearts of other polypteriforms suggests that cells containing melanin are not essential for normal fish heart function. Basing on literature data concerning tetrapods, it can be inferred that the pigment cells of the heart of the gray bichir derive from the neural crest. If this were true, our findings would provide the first evidence for the presence of neural crest-derived cells in the subepicardium of adult hearts of early actinopterygians.

  16. Networks and pathways in pigmentation, health, and disease.

    PubMed

    Baxter, Laura L; Loftus, Stacie K; Pavan, William J

    2009-01-01

    Extensive studies of the biology of the pigment-producing cell (melanocyte) have resulted in a wealth of knowledge regarding the genetics and developmental mechanisms governing skin and hair pigmentation. The ease of identification of altered pigment phenotypes, particularly in mouse coat color mutants, facilitated early use of the pigmentary system in mammalian genetics and development. In addition to the large collection of developmental genetics data, melanocytes are of interest because their malignancy results in melanoma, a highly aggressive and frequently fatal cancer that is increasing in Caucasian populations worldwide. The genetic programs regulating melanocyte development, function, and malignancy are highly complex and only partially understood. Current research in melanocyte development and pigmentation is revealing new genes important in these processes and additional functions for previously known individual components. A detailed understanding of all the components involved in melanocyte development and function, including interactions with neighboring cells and response to environmental stimuli, will be necessary to fully comprehend this complex system. The inherent characteristics of pigmentation biology as well as the resources available to researchers in the pigment cell community make melanocytes an ideal cell type for analysis using systems biology approaches. In this review, the study of melanocyte development and pigmentation is considered as a candidate for systems biology-based analyses.

  17. Genetic analyses of visual pigments of the pigeon (Columba livia).

    PubMed Central

    Kawamura, S; Blow, N S; Yokoyama, S

    1999-01-01

    We isolated five classes of retinal opsin genes rh1(Cl), rh2(Cl), sws1(Cl), sws2(Cl), and lws(Cl) from the pigeon; these encode RH1(Cl), RH2(Cl), SWS1(Cl), SWS2(Cl), and LWS(Cl) opsins, respectively. Upon binding to 11-cis-retinal, these opsins regenerate the corresponding photosensitive molecules, visual pigments. The absorbance spectra of visual pigments have a broad bell shape with the peak, being called lambdamax. Previously, the SWS1(Cl) opsin cDNA was isolated from the pigeon retinal RNA, expressed in cultured COS1 cells, reconstituted with 11-cis-retinal, and the lambdamax of the resulting SWS1(Cl) pigment was shown to be 393 nm. In this article, using the same methods, the lambdamax values of RH1(Cl), RH2(Cl), SWS2(Cl), and LWS(Cl) pigments were determined to be 502, 503, 448, and 559 nm, respectively. The pigeon is also known for its UV vision, detecting light at 320-380 nm. Being the only pigments that absorb light below 400 nm, the SWS1(Cl) pigments must mediate its UV vision. We also determined that a nonretinal P(Cl) pigment in the pineal gland of the pigeon has a lambdamax value at 481 nm. PMID:10581289

  18. 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

  19. Retinal pigment epithelial cell necroptosis in response to sodium iodate

    PubMed Central

    Hanus, J; Anderson, C; Sarraf, D; Ma, J; Wang, S

    2016-01-01

    Age-related macular degeneration (AMD) is a degenerative disease of the retina and the leading cause of blindness in the elderly in developed countries. The late stage of dry AMD, or geographic atrophy (GA), is characterized by extensive retinal pigment epithelium (RPE) degeneration. The underlying molecular mechanism for RPE cell death in GA remains unclear. Our previous study has established that RPE cells die predominantly from necroptosis in response to oxidative stress in vitro. Here, we extend our study and aim to characterize the nature of RPE cell death in response to sodium iodate (NaIO3) in vitro and in a NaIO3-induced retina degeneration mouse model. We found that NaIO3 induces RPE necroptosis in vitro by using a combination of molecular hallmarks. By using TUNEL assays, active caspase-3 and HMGB1 immunostaining, we confirmed that photoreceptor cells die mainly from apoptosis and RPE cells die mainly from necroptosis in response to NaIO3 in vivo. RPE necroptosis in this model is also supported by use of the RIPK1 inhibitor, Necrostatin-1. Furthermore, using novel RIPK3-GFP transgenic mouse lines, we detected RIPK3 aggregation, a hallmark of necroptosis, in the RPE cells in vivo after NaIO3 injection. Our findings suggest the necessity of re-evaluating RPE cell death mechanism in AMD models and have the potential to influence therapeutic development for dry AMD, especially GA. PMID:27551542

  20. Simple Raman Instrument for in Vivo Detection of Macular Pigments

    PubMed Central

    ERMAKOV, IGOR V.; ERMAKOVA, MAIA R.; GELLERMANN, WERNER

    2011-01-01

    Raman spectroscopy holds promise as a novel noninvasive technology for the quantification of the macular pigments (MP) lutein and zeaxanthin. These compounds, which are members of the carotenoid family, are thought to prevent or delay the onset of age-related macular degeneration, the leading cause of irreversible blindness in the elderly. It is highly likely that they achieve this protection through their function as optical filters and/or antioxidants. Using resonant excitation in the visible region, we measure and quantify the Raman signals that originate from the carbon double bond (C=C) stretch vibrations of the π-conjugated molecule backbone. In this manuscript we describe the construction and performance of a novel compact MP Raman instrument utilizing dielectric angle-tuned band-pass filters for wavelength selection and a single-channel photo-multiplier for the detection of MP Raman responses. MP concentration measurements are fast and accurate, as seen in our experiments with model eyes and living human eyes. The ease and rapidity of Raman MP measurements, the simplicity of the instrumentation, the high accuracy of the measurements, and the lack of significant systematic errors should make this technology attractive for widespread clinical research. PMID:16053555

  1. Arthroscopic treatment of pigmented villonodular synovitis of the knee.

    PubMed

    Zvijac, J E; Lau, A C; Hechtman, K S; Uribe, J W; Tjin-A-Tsoi, E W

    1999-09-01

    Pigmented villonodular synovitis (PVNS) is a rare disease, with multiple forms, anatomic sites, and treatment methods having been described. During a 10-year period, 14 patients, 7 male and 7 female, average age 35 years (range, 19 to 64 years) were treated for PVNS with arthroscopic partial or total synovectomy. Average follow-up was 42 months (range, 8 to 83 months). Twelve patients had diffuse and 2 had a localized form. Results were assessed subjectively, clinically, and radiographically, and were rated as excellent, good, fair, or poor. There were no complications and 10 patients (72%) were rated as excellent or good, 2 patients (14%) as fair, and 2 patients (14%) as poor. The recurrence rate was 14% and occurred in the group with diffuse PVNS. Radiographs did not show any bone erosion. The most widely accepted treatment for PVNS is synovectomy, and both open and arthroscopic synovectomy have been advocated as treatment. Advantages of arthroscopic treatment include accurate evaluation of the knee joint, treatment of other pathology, more rapid rehabilitation, decreased risk of joint stiffness, and less pain. In our experience, it appears that arthroscopic synovectomy is an effective method of treatment of this disorder.

  2. Characterizing pigments with hyperspectral imaging variable false-color composites

    NASA Astrophysics Data System (ADS)

    Hayem-Ghez, Anita; Ravaud, Elisabeth; Boust, Clotilde; Bastian, Gilles; Menu, Michel; Brodie-Linder, Nancy

    2015-11-01

    Hyperspectral imaging has been used for pigment characterization on paintings for the last 10 years. It is a noninvasive technique, which mixes the power of spectrophotometry and that of imaging technologies. We have access to a visible and near-infrared hyperspectral camera, ranging from 400 to 1000 nm in 80-160 spectral bands. In order to treat the large amount of data that this imaging technique generates, one can use statistical tools such as principal component analysis (PCA). To conduct the characterization of pigments, researchers mostly use PCA, convex geometry algorithms and the comparison of resulting clusters to database spectra with a specific tolerance (like the Spectral Angle Mapper tool on the dedicated software ENVI). Our approach originates from false-color photography and aims at providing a simple tool to identify pigments thanks to imaging spectroscopy. It can be considered as a quick first analysis to see the principal pigments of a painting, before using a more complete multivariate statistical tool. We study pigment spectra, for each kind of hue (blue, green, red and yellow) to identify the wavelength maximizing spectral differences. The case of red pigments is most interesting because our methodology can discriminate the red pigments very well—even red lakes, which are always difficult to identify. As for the yellow and blue categories, it represents a good progress of IRFC photography for pigment discrimination. We apply our methodology to study the pigments on a painting by Eustache Le Sueur, a French painter of the seventeenth century. We compare the results to other noninvasive analysis like X-ray fluorescence and optical microscopy. Finally, we draw conclusions about the advantages and limits of the variable false-color image method using hyperspectral imaging.

  3. Kinetics of thermal activation of an ultraviolet cone pigment.

    PubMed

    Mooney, Victoria; Sekharan, Sivakumar; Liu, Jian; Guo, Ying; Batista, Victor S; Yan, Elsa C Y

    2015-01-14

    Visual pigments can be thermally activated via isomerization of the retinyl chromophore and hydrolysis of the Schiff base (SB) through which the retinyl chromophore is bound to the opsin protein. Here, we present the first combined experimental and theoretical study of the thermal activation of a Siberian hamster ultraviolet (SHUV) pigment. We measured the rates of thermal isomerization and hydrolysis in the SHUV pigment and bovine rhodopsin. We found that these rates were significantly faster in the UV pigment than in rhodopsin due to the difference in the structural and electrostatic effects surrounding the unprotonated Schiff base (USB) retinyl chromophore in the UV pigment. Theoretical (DFT-QM/MM) calculations of the cis-trans thermal isomerization revealed a barrier of ∼23 kcal/mol for the USB retinyl chromophore in SHUV compared to ∼40 kcal/mol for protonated Schiff base (PSB) chromophore in rhodopsin. The lower barrier for thermal isomerization in the SHUV pigment is attributed to the (i) lessening of the steric restraints near the β-ionone ring and SB ends of the chromophore, (ii) displacement of the transmembrane helix 6 (TM6) away from the binding pocket toward TM5 due to absence of the salt bridge between the USB and the protonated E113 residue, and (iii) change in orientation of the hydrogen-bonding networks (HBNs) in the extracellular loop 2 (EII). The results in comparing thermal stability of UV cone pigment and rhodopsin provide insight into molecular evolution of vertebrate visual pigments in achieving low discrete dark noise and high photosensitivity in rod pigments for dim-light vision.

  4. Effects of palmitoyl-KVK-L-ascorbic acid on skin wrinkles and pigmentation.

    PubMed

    Kim, Hyeong Mi; An, Hyo Sun; Bae, Jung-Soo; Kim, Jung Yun; Choi, Chi Ho; Kim, Ju Yeon; Lim, Joo Hyuck; Choi, Joon-Hun; Song, Hyunnam; Moon, Sung Ho; Park, Young Jun; Chang, Shin-Jae; Choi, Sun Young

    2017-03-16

    Wrinkle formation and abnormal pigmentation are major clinical alterations associated with skin aging. As the aim of our study was to investigate the effects of palmitoyl-KVK-L-ascorbic acid on skin aging, the anti-wrinkle and depigmentation effects of palmitoyl-KVK-L-ascorbic acid were evaluated by measuring collagen expression in dermal fibroblast cells and inhibition of melanogenesis in B16F1 cells, respectively. The anti-aging effect of palmitoyl-KVK-L-ascorbic acid cream was also evaluated against a placebo cream in a clinical trial. Our results confirmed that the expression of type Ι collagen in dermal fibroblast cells treated with palmitoyl-KVK-L-ascorbic acid (0.1-4 μg/mL) increased in a dose-dependent manner. In B16F1 cells, treatment with 20 μg/mL palmitoyl-KVK-L-ascorbic acid reduced the melanin content by approximately 20% compared to alpha-melanocyte stimulating hormone treatment. In the clinical trial, application of palmitoyl-KVK-L-ascorbic acid cream led to an improvement in skin roughness and lightness in 12 and 8 weeks, respectively. Our data show that palmitoyl-KVK-L-ascorbic acid is an effective anti-aging agent that reduces wrinkles and abnormal skin pigmentation.

  5. The extraction of pigments from fresh Laminaria japonica

    NASA Astrophysics Data System (ADS)

    Yang, Liqun; Li, Pengcheng; Fan, Shoujin

    2008-05-01

    The pigments in Laminaria japonica was extracted with six organic solvents and analyzed in spectroscopy analysis. The extractions conditions were screened by an orthogonal test and the quantity of extracted pigments was determined spectroscopically. The results show that: (1) among the six organic solvents, acetone was the most effective one for the extraction; (2) the optimum extraction conditions were as follows: the ratio of S/M (solvent volume/ material weight) was 30 ml/g; fresh seaweed was extracted 2 times in 2 h; (3) the average total content of pigments was 1.85 mg/g (calculated with dry L. japonica).

  6. Mineral resource of the month: iron oxide pigments

    USGS Publications Warehouse

    ,

    2008-01-01

    The article discusses iron oxide pigments, which have been used as colorants since human began painting as they resist color change due to sunlight exposure, have good chemical resistance and are stable under normal ambient conditions. Cyprus, Italy and Spain are among the countries that are known for the production of iron oxide pigments. Granular forms of iron oxides and nano-sized materials are cited as developments in the synthetic iron oxide pigment industry which are being used in computer disk drives and nuclear magnetic resonance imaging.

  7. Cholecystokinin octapeptide antagonizes apoptosis in human retinal pigment epithelial cells.

    PubMed

    Liu, Yuan; Zhang, Yueling; Gu, Zhaohui; Hao, Lina; Du, Juan; Yang, Qian; Li, Suping; Wang, Liying; Gong, Shilei

    2014-07-15

    Although cholecystokinin octapeptide-8 is important for neurological function, its neuroprotective properties remain unclear. We speculated that cholecystokinin octapeptide-8 can protect human retinal pigment epithelial cells against oxidative injury. In this study, retinal pigment epithelial cells were treated with peroxynitrite to induce oxidative stress. Peroxynitrite triggered apoptosis in these cells, and increased the expression of Fas-associated death domain, Bax, caspa-se-8 and Bcl-2. These changes were suppressed by treatment with cholecystokinin octapeptide-8. These results suggest that cholecystokinin octapeptide-8 can protect human retinal pigment epithelial cells against apoptosis induced by peroxynitrite.

  8. Cholecystokinin octapeptide antagonizes apoptosis in human retinal pigment epithelial cells

    PubMed Central

    Liu, Yuan; Zhang, Yueling; Gu, Zhaohui; Hao, Lina; Du, Juan; Yang, Qian; Li, Suping; Wang, Liying; Gong, Shilei

    2014-01-01

    Although cholecystokinin octapeptide-8 is important for neurological function, its neuroprotective properties remain unclear. We speculated that cholecystokinin octapeptide-8 can protect human retinal pigment epithelial cells against oxidative injury. In this study, retinal pigment epithelial cells were treated with peroxynitrite to induce oxidative stress. Peroxynitrite triggered apoptosis in these cells, and increased the expression of Fas-associated death domain, Bax, caspa-se-8 and Bcl-2. These changes were suppressed by treatment with cholecystokinin octapeptide-8. These results suggest that cholecystokinin octapeptide-8 can protect human retinal pigment epithelial cells against apoptosis induced by peroxynitrite. PMID:25221599

  9. Pigmented basal cell carcinoma mimicking a superficial spreading melanoma.

    PubMed

    Hasbún Acuña, Paula; Cullen Aravena, Roberto; Maturana Donaire, César; Ares Mora, Raúl; Porras Kusmanic, Ninoska

    2016-12-20

    Basal cell carcinoma is the most common form of skin cancer, especially in elderly people. Pigmented basal cell carcinoma is a rare subtype and has been described in the literature as a nodular and hyperpigmented lesion; rarely, it can appear as an extensive pigmented plate, which may be clinically indistinguishable from superficial spreading melanoma and Bowen disease. Dermatoscopy has a high sensitivity in the diagnosis of basal cell carcinoma. When Menzies criteria are used; however, the final diagnosis is made by histopathology. The objective of the present report is to analyze the case of a patient with pigmented basal cell carcinoma simulating a superficial spreading melanoma.

  10. Passivation of pigment particles for thermal control coatings

    NASA Technical Reports Server (NTRS)

    Farley, E. P.; Sancier, K. M.; Morrison, S. R.

    1973-01-01

    Five powders were received for plasma calcining during this report period. The particle size using a fluid energy mill, and obtained pigments that could be plasma calcined. Optimum results are obtained in the plasma calcining of zinc orthotitanate when finely dispersed particles are subjected to a calculated plasma temperature of 1670 C. Increasing the plasma calcining time by using multiple passes through the plasma stabilized the pigment to vacuum UV irradiation was evidenced by the resulting ESR spectra but slightly decreased the whiteness of the pigment. The observed darkening is apparently associated with the formation of Ti(+3) color centers.

  11. The penetration depth and lateral distribution of pigment related to the pigment grain size and the calendering of paper

    NASA Astrophysics Data System (ADS)

    Bülow, K.; Kristiansson, P.; Schüler, B.; Tullander, E.; Östling, S.; Elfman, M.; Malmqvist, K.; Pallon, J.; Shariff, A.

    2002-04-01

    The interaction of ink and newspaper has been investigated and the specific question of penetration of ink into the paper has been addressed with a nuclear microprobe using particle induced X-ray emission. The penetration depth of the newsprint is a critical factor in terms of increasing the quality of newsprint and minimising the amount of ink used. The objective of the experiment was to relate the penetration depth of pigment with the calendering of the paper. The dependence of the penetration depth on the pigment grain size was also studied. To study the penetration depth of pigment in paper, cyan ink with Cu as a tracer of the coloured pigment was used. For the study of the penetration depth dependence of pigment size, specially grounded Japanese ink with well-defined pigment grain size was used. This was compared to Swedish ink with pigment grains with normal size-distribution. The results show that the calendering of the paper considerably affects the penetration depth of ink.

  12. 75 FR 14468 - Carbazole Violet Pigment 23 From China and India

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-25

    ... COMMISSION Carbazole Violet Pigment 23 From China and India AGENCY: United States International Trade... carbazole violet pigment 23 from India and the antidumping duty orders on carbazole violet pigment 23 from... whether revocation of the countervailing duty order on carbazole violet pigment 23 from India and...

  13. 21 CFR 73.3128 - Mica-based pearlescent pigments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... pigments. (a) Identity and specifications. The color additive is formed by depositing titanium or iron salts from a basic solution onto mica, followed by calcination to produce titanium dioxide or...

  14. Microanalysis study of archaeological mural samples containing Maya blue pigment

    NASA Astrophysics Data System (ADS)

    Sánchez del Río, M.; Martinetto, P.; Somogyi, A.; Reyes-Valerio, C.; Dooryhée, E.; Peltier, N.; Alianelli, L.; Moignard, B.; Pichon, L.; Calligaro, T.; Dran, J.-C.

    2004-10-01

    Elemental analysis by X-ray fluorescence and particle induced X-ray emission is applied to the study of several Mesoamerican mural samples containing blue pigments. The most characteristic blue pigment is Maya blue, a very stable organo-clay complex original from Maya culture and widely used in murals, pottery and sculptures in a vast region of Mesoamerica during the pre-hispanic time (from VIII century) and during the colonization until 1580. The mural samples come from six different archaeological sites (four pre-hispanic and two from XVI century colonial convents). The correlation between the presence of some elements and the pigment colour is discussed. From the comparative study of the elemental concentration, some conclusions are drawn on the nature of the pigments and the technology used.

  15. 21 CFR 73.3128 - Mica-based pearlescent pigments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... pigments. (a) Identity and specifications. The color additive is formed by depositing titanium or iron salts from a basic solution onto mica, followed by calcination to produce titanium dioxide or...

  16. Nematicidal activity of microbial pigment from Serratia marcescens.

    PubMed

    Rahul, Suryawanshi; Chandrashekhar, Patil; Hemant, Borase; Chandrakant, Narkhede; Laxmikant, Shinde; Satish, Patil

    2014-01-01

    Ineffectiveness of available nematicides and the high damage caused by plant-parasitic nematodes result in the urgent need to find some natural remedy for their control. Bioactivity of the pigment extracted from Serratia marcescens was screened for controlling nematodes at their juvenile stage. Test pigment was found effective against juvenile stages of Radopholus similis and Meloidogyne javanica at low concentrations (LC50 values, 83 and 79 μg/mL, respectively) as compared with positive control of copper sulphate (LC50 values, 380 and 280 μg/mL, respectively). The pigment also exhibited inhibition on nematode egg-hatching ability. Characterisation of extracted pigment with TLC, FTIR, HPLC, HPTLC and spectroscopic analysis confirmed the presence of prodigiosin as a bioactive metabolite. Considering the sensory mechanism of pathogen recognition by nematodes, the use of microbial secondary metabolites can be effective for nematode control rather than using whole organism.

  17. Blue metal complex pigments involved in blue flower color

    PubMed Central

    Takeda, Kosaku

    2006-01-01

    The blue pigment of cornflower, protocyanin, has been investigated for a long time, but its precise structure was not entirely explained until recently. The molecular structure of the pigment was recently shown to be a metal complex of six molecules each of anthocyanin and flavone glycoside, with one ferric iron, one magnesium and two calcium ions by X-ray crystallographic analysis. The studies provided the answer to the question posed in the early part of the last century, “why is the cornflower blue and rose red when both flowers contain the same anthocyanin?” This work was achieved on the basis of the results of long years of the studies made by many researchers. In this review, the author focuses on the investigations of the blue metal complex pigments involved in the bluing of flowers, commelinin from Commelina commusis, protocyanin from Centaurea cyanus, protodelphin from Salvia patens and hydrangea blue pigment. PMID:25792777

  18. Blue metal complex pigments involved in blue flower color.

    PubMed

    Takeda, Kosaku

    2006-05-01

    The blue pigment of cornflower, protocyanin, has been investigated for a long time, but its precise structure was not entirely explained until recently. The molecular structure of the pigment was recently shown to be a metal complex of six molecules each of anthocyanin and flavone glycoside, with one ferric iron, one magnesium and two calcium ions by X-ray crystallographic analysis. The studies provided the answer to the question posed in the early part of the last century, "why is the cornflower blue and rose red when both flowers contain the same anthocyanin?" This work was achieved on the basis of the results of long years of the studies made by many researchers. In this review, the author focuses on the investigations of the blue metal complex pigments involved in the bluing of flowers, commelinin from Commelina commusis, protocyanin from Centaurea cyanus, protodelphin from Salvia patens and hydrangea blue pigment.

  19. 21 CFR 73.3128 - Mica-based pearlescent pigments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... pigments. (a) Identity and specifications. The color additive is formed by depositing titanium or iron salts from a basic solution onto mica, followed by calcination to produce titanium dioxide or...

  20. Fungal polyketide azaphilone pigments as future natural food colorants?

    PubMed

    Mapari, Sameer A S; Thrane, Ulf; Meyer, Anne S

    2010-06-01

    The recent approval of fungal carotenoids as food colorants by the European Union has strengthened the prospects for fungal cell factories for the production of polyketide pigments. Fungal production of colorants has the main advantage of making the manufacturer independent of the seasonal supply of raw materials, thus minimizing batch-to-batch variations. Here, we review the potential of polyketide pigments produced from chemotaxonomically selected non-toxigenic fungal strains (e.g. Penicillium and Epicoccum spp.) to serve as food colorants. We argue that the production of polyketide azaphilone pigments from such potentially safe hosts is advantageous over traditional processes that involve Monascus spp., which risks co-production of the mycotoxin citrinin. Thus, there is tremendous potential for the development of robust fungal production systems for polyketide pigments, both to tailor functionality and to expand the color palette of contemporary natural food colorants.

  1. Multi-analytical study of historical semiconductor pigments

    NASA Astrophysics Data System (ADS)

    Capogrosso, V.

    2015-03-01

    This work is focused on the study of semiconductor-based pigments, which substituted traditional pigments in the second half of the 19th century. Synthetic semiconductor pigments may be chemically unstable due to the presence of many impurities unintentionally introduced during manufacturing. The aim of this work is to provide an insight on the application of X-ray Fluorescence (XRF) for the analysis of these painting materials, including both Cd- and Zn-based pigments. Three different approaches have been followed: the semi-quantitative analysis of samples with similar elemental composition, the complementary use of XRF and Raman spectroscopy for the analysis of elemental and molecular composition and the synchrotron-based XRF and XANES for the detection of impurities. The synergetic combination of different techniques provides information useful for the definition of specific markers for future analysis of paint-samples with implications for the conservation and treatment of late 19th and early 20th century paintings.

  2. PIGMENT DEPOSITION IN VISCERA ASSOCIATED WITH PROLONGED CHLORPROMAZINE THERAPY.

    PubMed

    GREINER, A C; NICOLSON, G A

    1964-09-19

    Twelve physically healthy young adult mental hospital patients died unexpectedly while on prolonged chlorpromazine therapy. Five of them had clinically obvious pigmentation of the exposed skin. Two of these had impairment of vision as well. Autopsies were performed on all 12 patients. Extensive deposits of pigment (exhibiting the physical and histochemical properties of melanin) were present in macrophages in the dermis and throughout the reticuloendothelial system, and in the parenchymal cells of internal organs. The dopa tyrosinase reaction indicated increased melanocyte activity in the epidermis.The possible mechanism of production of this pigment is discussed, and the belief is expressed that the increased melanin production is due, at least partly, to the effect of chlorpromazine on the autonomic nervous system, blocking the production of pigment-lightening factors, of which melatonin is the most important. A short outline of contemplated further investigation is given.

  3. Glucose metabolism in rat retinal pigment epithelium.

    PubMed

    Coffe, Víctor; Carbajal, Raymundo C; Salceda, Rocío

    2006-01-01

    The retinal pigment epithelium (RPE) is the major transport pathway for exchange of metabolites and ions between choroidal blood supply and the neural retina. To gain insight into the mechanisms controlling glucose metabolism in RPE and its possible relationship to retinopathy, we studied the influence of different glucose concentrations on glycogen and lactate levels and CO(2) production in RPE from normal and streptozotocin-treated diabetic rats. Incubation of normal RPE in the absence of glucose caused a decrease in lactate production and glycogen content. In normal RPE, increasing glucose concentrations from 5.6 mM to 30 mM caused a four-fold increase in glucose accumulation and CO(2) yield, as well as reduction in lactate and glycogen production. In RPE from diabetic rats glucose accumulation did not increase in the presence of high glucose substrate, but it showed a four- and a seven-fold increase in CO(2) production through the mitochondrial and pentose phosphate pathways, respectively. We found high glycogen levels in RPE which can be used as an energy reserve for RPE itself and/or neural retina. Findings further show that the RPE possesses a high oxidative capacity. The large increase in glucose shunting to the pentose phosphate pathway in diabetic retina exposed to high glucose suggests a need for reducing capacity, consistent with increased oxidative stress.

  4. UV ADAPTATION; pigmentation and protection against overexposure.

    PubMed

    de Gruijl, Frank R

    2017-03-07

    The skin is known to adapt to UV exposures, i.e., become less sensitive to sunburn. Reported decreases in sensitivity vary widely from well over 10 fold down to a negligible 10%. This appears to depend importantly on the UV irradiation spectrum to which the skin adapts and on the UV irradiation spectrum that is used to test the sensitivity. The sensitivity is conventionally and generally assessed by the reciprocal of the minimal erythema dose (MED): the UV dose causing a just perceptible reddening of the skin after 8 - 24 h. However, MED is much too subtle for everyday life: people will not notice a minimal reddening and commonly consider themselves sunburnt at considerably higher UV doses causing an intense reddening. Levels of adaptation of a well-tanned skin may be substantially higher at these more intense levels of reddening than MED levels. This expectation is based on the fact that people with a constitutively coloured skin may show moderate differences in MED with fair skinned people but far less steep increases in reddening with overexposures to solar simulated radiation (SSR). UVA exposure is known to enhance pigmentation and may thus be important in protection against overexposure to SSR. This article is protected by copyright. All rights reserved.

  5. Cuticle formation and pigmentation in beetles.

    PubMed

    Noh, Mi Young; Muthukrishnan, Subbaratnam; Kramer, Karl J; Arakane, Yasuyuki

    2016-10-01

    Adult beetles (Coleoptera) are covered primarily by a hard exoskeleton or cuticle. For example, the beetle elytron is a cuticle-rich highly modified forewing structure that shields the underlying hindwing and dorsal body surface from a variety of harmful environmental factors by acting as an armor plate. The elytron comes in a variety of colors and shapes depending on the coleopteran species. As in many other insect species, the cuticular tanning pathway begins with tyrosine and is responsible for production of a variety of melanin-like and other types of pigments. Tanning metabolism involves quinones and quinone methides, which also act as protein cross-linking agents for cuticle sclerotization. Electron microscopic analyses of rigid cuticles of the red flour beetle, Tribolium castaneum, have revealed not only numerous horizontal chitin-protein laminae but also vertically oriented columnar structures called pore canal fibers. This structural architecture together with tyrosine metabolism for cuticle tanning is likely to contribute to the rigidity and coloration of the beetle exoskeleton.

  6. Polyketides, toxins and pigments in Penicillium marneffei.

    PubMed

    Tam, Emily W T; Tsang, Chi-Ching; Lau, Susanna K P; Woo, Patrick C Y

    2015-10-30

    Penicillium marneffei (synonym: Talaromyces marneffei) is the most important pathogenic thermally dimorphic fungus in China and Southeastern Asia. The HIV/AIDS pandemic, particularly in China and other Southeast Asian countries, has led to the emergence of P. marneffei infection as an important AIDS-defining condition. Recently, we published the genome sequence of P. marneffei. In the P. marneffei genome, 23 polyketide synthase genes and two polyketide synthase-non-ribosomal peptide synthase hybrid genes were identified. This number is much higher than those of Coccidioides immitis and Histoplasma capsulatum, important pathogenic thermally dimorphic fungi in the Western world. Phylogenetically, these polyketide synthase genes were distributed evenly with their counterparts found in Aspergillus species and other fungi, suggesting that polyketide synthases in P. marneffei did not diverge from lineage-specific gene duplication through a recent expansion. Gene knockdown experiments and ultra-high performance liquid chromatography-photodiode array detector/electrospray ionization-quadruple time of flight-mass spectrometry analysis confirmed that at least four of the polyketide synthase genes were involved in the biosynthesis of various pigments in P. marneffei, including melanin, mitorubrinic acid, mitorubrinol, monascorubrin, rubropunctatin, citrinin and ankaflavin, some of which were mycotoxins and virulence factors of the fungus.

  7. Multifocal pigmented villonodular synovitis in a child

    PubMed Central

    Zhao, Liang; Zhou, Kaiyu; Hua, Yimin; Li, Yifei; Mu, Dezhi

    2016-01-01

    Abstract Introduction: Pigmented villonodular synovitis (PVNS) is a rare, benign proliferative disorder of the synovial membrane that typically presents in adults and affects a single joint. Multifocal PVNS is very rare, particularly in childhood. We reported a rare case of multifocal PVNS affecting over 20 joints in a child. Clinical procedure: A 7-year-old female patient had a 6-month history of multifocal joints swelling with mild pain. She was diagnosed as polyarticular juvenile idiopathic arthritis at a local hospital. Naproxen, methotrexate, infliximab, and pavlin were used to treat the patient for 2 months. However, the treatment had no effect, the joints swelling remained. The patient was then transferred to our hospital. Physical examination revealed multiple joints swelling, especially in the shoulders joints. Puncture fluid from a shoulder joint was bloody. Magnetic resonance imaging (MRI) revealed synovial thickening and hemosiderin deposition. Biopsy of joint synovium found villous nodules, the invasion of foam cells, and hemosiderin deposition. By collecting all of the evidence, the diagnosis of PVNS was confirmed. Conclusions: PVNS was easily misdiagnosed as rheumatoid arthritis and the formal treatment was usually delayed. This case described here is the first case of PVNS involving such a large numbers of joints that has been reported in the literature. PMID:27537585

  8. Macular pigment assessment by motion photometry.

    PubMed

    Moreland, J D

    2004-10-15

    A Moreland anomaloscope was modified to measure macular pigment optical density (MPOD) profiles by motion photometry. A grating (spatial frequency 0.38 c deg(-1)), whose alternate bars were filled, respectively, with 460 nm (maximum MP absorption) and 580 nm (zero MP absorption) lights, drifted steadily at 37 degrees s(-1). The subject adjusted the 580 nm radiance to minimise perceived motion (equiluminance between 460 and 580 nm). Five or more settings were made for two foveal fields (0.9 degrees and 2.2 degrees diameter) and 11 extrafoveal annular fields (0.8 degrees -7.5 degrees eccentricity). Twenty subjects made measurements for both eyes: some with replications. MPOD profiles varied in scale (0.18-0.75 for the 0.9 degrees foveal field) and in shape. A mean profile was derived. Foveal data were optimally aligned with annular data in that profile when plotted at 0.71 of the foveal field radius. Factors that limit precision were identified, such as fixation errors foveally and Troxler's effect parafoveally.

  9. Fluorescent pigments in corals are photoprotective

    NASA Astrophysics Data System (ADS)

    Salih, Anya; Larkum, Anthony; Cox, Guy; Kühl, Michael; Hoegh-Guldberg, Ove

    2000-12-01

    All reef-forming corals depend on the photosynthesis performed by their algal symbiont, and such corals are therefore restricted to the photic zone. The intensity of light in this zone declines over several orders of magnitude-from high and damaging levels at the surface to extreme shade conditions at the lower limit. The ability of corals to tolerate this range implies effective mechanisms for light acclimation and adaptation. Here we show that the fluorescent pigments (FPs) of corals provide a photobiological system for regulating the light environment of coral host tissue. Previous studies have suggested that under low light, FPs may enhance light availability. We now report that in excessive sunlight FPs are photoprotective; they achieve this by dissipating excess energy at wavelengths of low photosynthetic activity, as well as by reflecting of visible and infrared light by FP-containing chromatophores. We also show that FPs enhance the resistance to mass bleaching of corals during periods of heat stress, which has implications for the effect of environmental stress on the diversity of reef-building corals, such as enhanced survival of a broad range of corals allowing maintenance of habitat diversity.

  10. Polyketides, Toxins and Pigments in Penicillium marneffei

    PubMed Central

    Tam, Emily W. T.; Tsang, Chi-Ching; Lau, Susanna K. P.; Woo, Patrick C. Y.

    2015-01-01

    Penicillium marneffei (synonym: Talaromyces marneffei) is the most important pathogenic thermally dimorphic fungus in China and Southeastern Asia. The HIV/AIDS pandemic, particularly in China and other Southeast Asian countries, has led to the emergence of P. marneffei infection as an important AIDS-defining condition. Recently, we published the genome sequence of P. marneffei. In the P. marneffei genome, 23 polyketide synthase genes and two polyketide synthase-non-ribosomal peptide synthase hybrid genes were identified. This number is much higher than those of Coccidioides immitis and Histoplasma capsulatum, important pathogenic thermally dimorphic fungi in the Western world. Phylogenetically, these polyketide synthase genes were distributed evenly with their counterparts found in Aspergillus species and other fungi, suggesting that polyketide synthases in P. marneffei did not diverge from lineage-specific gene duplication through a recent expansion. Gene knockdown experiments and ultra-high performance liquid chromatography-photodiode array detector/electrospray ionization-quadruple time of flight-mass spectrometry analysis confirmed that at least four of the polyketide synthase genes were involved in the biosynthesis of various pigments in P. marneffei, including melanin, mitorubrinic acid, mitorubrinol, monascorubrin, rubropunctatin, citrinin and ankaflavin, some of which were mycotoxins and virulence factors of the fungus. PMID:26529013

  11. Fumed metallic oxides and conventional pigments for glossy inkjet paper

    NASA Astrophysics Data System (ADS)

    Lee, Hyunkook

    Product development activity in the area of inkjet printing papers has accelerated greatly to meet the rapidly growing market for inkjet papers. Advancements in inkjet printing technology have also placed new demands on the paper substrate due to faster printing rates, greater resolution through increased drop volumes, and colorants added to the ink. To meet these requirements, papermakers are turning to pigmented size press formulations or pigmented coating systems. For inkjet coating applications, both the internal porosity of the pigment particles as well as the packing porosity of the coating affect print quality and dry time. Pores between the pigment particles allow for rapid diffusion of ink fluids into the coating structure, while also providing capacity for ink fluid uptake. Past research has shown the presence of coating cracks to increase the microroughness of the papers, consequently reducing the gloss of the silica/polyvinyl alcohol based coating colors. Coating cracks were not observed, at the same level of magnification, in the scanning electron microscopy images of alumina/polyvinyl alcohol coated papers. Studies are therefore needed to understand the influence of coating cracking on the microroughening of silica/polyvinyl alcohol based coatings and consequences to coating and ink gloss. Since micro roughening is known to be linked to shrinkage of the coating layer, studies are needed to determine if composite pigments can be formulated, which would enable the coating solids of the formulations to be increased to minimize the shrinkage of coating layer during drying. Coating solids greater than 55% solids are needed to reduce the difference between application solids and the coating's immobilization solids point in order to reduce shrinkage. The aim of this research was to address the above mentioned needed studies. Studies were performed to understand the influence of particle packing on gloss and ink jet print quality. Composite pigment structures

  12. Comparison of Clinicopathologic Features and Survival of Histopathologically Amelanotic and Pigmented Melanomas: A Population-Based Study

    PubMed Central

    Thomas, Nancy E.; Kricker, Anne; Waxweiler, Weston T.; Dillon, Patrick M.; Busam, Klaus J.; From, Lynn; Groben, Pamela A.; Armstrong, Bruce K.; Anton-Culver, Hoda; Gruber, Stephen B.; Marrett, Loraine D.; Gallagher, Richard P.; Zanetti, Roberto; Rosso, Stefano; Dwyer, Terence; Venn, Alison; Kanetsky, Peter A.; Orlow, Drs. Irene; Paine, Susan; Ollila, David W.; Reiner, Anne S.; Luo, Li; Hao, Honglin; Frank, Jill S.; Begg, Colin B.; Berwick, Marianne

    2014-01-01

    Importance Previous studies have reported that histopathologically amelanotic melanoma is associated with poorer survival than pigmented melanoma; however, small numbers of amelanotic melanomas, selected populations, lack of centralized pathology review, or no adjustment for stage limit interpretation or generalization of results from prior studies. Objective To compare melanoma-specific survival between patients with histopathologically amelanotic and those with pigmented melanoma in a large international population-based study. Design Survival analysis with median follow-up of 7.6 years. Setting The Genes, Environment, and Melanoma study enrolled incident cases of melanoma diagnosed in 1998-2003 from international population-based cancer registries. Participants A total of 2,995 patients with 3,486 invasive primary melanomas centrally scored for histologic pigmentation. Main Outcomes and Measurements Clinicopathologic predictors and melanoma-specific survival of histologically amelanotic and pigmented melanoma were compared using generalized estimating equations and Cox regression models, respectively. Results Eight percent of melanomas (275 of 3,467) were histopathologically amelanotic. Female sex, nodular and unclassified or other histologic subtypes, increased Breslow thickness, presence of mitoses, severe solar elastosis, and lack of a co-existing nevus were independently associated with amelanotic melanoma (each P < .05). Amelanotic melanoma was generally of a higher American Joint Committee on Cancer (AJCC) tumor stage at diagnosis (P for trend <.001) than pigmented melanoma. Hazard of death from melanoma was higher for amelanotic than pigmented melanoma [hazard ratio (HR), 2.0; 95% confidence interval (CI), 1.4-3.0; P< .001], adjusted for age, sex anatomic site, and study design variables; but survival did not differ once AJCC tumor stage was also taken into account, (HR, 0.8; 95% CI, 0.5-1.2; P = .36). Conclusions and Relevance At the population level

  13. Comparison of clinicopathologic features and survival of histopathologically amelanotic and pigmented melanomas: a population-based study.

    PubMed

    Thomas, Nancy E; Kricker, Anne; Waxweiler, Weston T; Dillon, Patrick M; Busman, Klaus J; From, Lynn; Groben, Pamela A; Armstrong, Bruce K; Anton-Culver, Hoda; Gruber, Stephen B; Marrett, Loraine D; Gallagher, Richard P; Zanetti, Roberto; Rosso, Stefano; Dwyer, Terence; Venn, Alison; Kanetsky, Peter A; Orlow, Irene; Paine, Susan; Ollila, David W; Reiner, Anne S; Luo, Li; Hao, Honglin; Frank, Jill S; Begg, Colin B; Berwick, Marianne

    2014-12-01

    IMPORTANCE Previous studies have reported that histopathologically amelanotic melanoma is associated with poorer survival than pigmented melanoma; however, small numbers of amelanotic melanomas, selected populations, lack of centralized pathologic review, or no adjustment for stage limit the interpretation or generalization of results from prior studies.OBJECTIVE To compare melanoma-specific survival between patients with histopathologically amelanotic and those with pigmented melanoma in a large international population-based study.DESIGN, SETTING, AND PARTICIPANTS Survival analysis with a median follow-up of 7.6 years.The study population comprised 2995 patients with 3486 invasive primary melanomas centrally scored for histologic pigmentation from the Genes, Environment, and Melanoma(GEM) Study, which enrolled incident cases of melanoma diagnosed in 1998 through 2003 from international population-based cancer registries.MAIN OUTCOMES AND MEASURES Clinicopathologic predictors and melanoma-specific survival of histologically amelanotic and pigmented melanoma were compared using generalized estimating equations and Cox regression models, respectively.RESULTS Of 3467 melanomas, 275 (8%) were histopathologically amelanotic. Female sex,nodular and unclassified or other histologic subtypes, increased Breslow thickness, presence of mitoses, severe solar elastosis, and lack of a coexisting nevus were independently associated with amelanotic melanoma (each P < .05). Amelanotic melanoma was generally ofa higher American Joint Committee on Cancer (AJCC) tumor stage at diagnosis (odds ratios[ORs] [95%CIs] between 2.9 [1.8-4.6] and 11.1 [5.8-21.2] for tumor stages between T1b and T3b and ORs [95%CIs] of 24.6 [13.6-44.4] for T4a and 29.1 [15.5-54.9] for T4b relative to T1a;P value for trend, <.001) than pigmented melanoma. Hazard of death from melanoma was higher for amelanotic than for pigmented melanoma (hazard ratio [HR], 2.0; 95%CI, 1.4-3.0)(P < .001), adjusted for age, sex

  14. The influence of visible light and inorganic pigments on fluorescence excitation emission spectra of egg-, casein- and collagen-based painting media

    NASA Astrophysics Data System (ADS)

    Nevin, A.; Anglos, D.; Cather, S.; Burnstock, A.

    2008-07-01

    Spectrofluorimetric analysis of proteinaceous binding media is particularly promising because proteins employed in paintings are often fluorescent and media from different sources have significantly different fluorescence spectral profiles. Protein-based binding media derived from eggs, milk and animal tissue have been used for painting and for conservation, but their analysis using non-destructive techniques is complicated by interferences with pigments, their degradation and their low concentration. Changes in the fluorescence excitation emission spectra of films of binding media following artificial ageing to an equivalent of 50 and 100 years of museum lighting include the reduction of bands ascribed to tyrosine, tryptophan and Maillard reaction products and an increase in fluorescent photodegradation. Fluorescence of naturally aged paint is dependent on the nature of the pigment present and, with egg-based media, in comparison with un-pigmented films, emissions ascribed to amino acids are more pronounced.

  15. Detachments of the retinal pigment epithelium at the posterior pole.

    PubMed

    Noble, K G; Levitzky, M J; Carr, R E

    1976-08-01

    Multiple vitelliform cysts of the retina, a disorder of unknown cause in which there are multiple detachments of the retinal pigment epithelium at the posterior pole, occurred in five patients. In four patients all lesions were located outside the parafoveal area while one patient showed bilateral foveal elevations associated with more eccentric detachments. Several patients showed slow resolution of some of the detachments with mild disturbances of the pigment epithelium.

  16. Transition dipole moments of the Qy band in photosynthetic pigments.

    PubMed

    Oviedo, M Belén; Sánchez, Cristián G

    2011-11-10

    From studying the time evolution of the single electron density matrix within a density functional tight-binding formalism we calculate the Q(y) transition dipole moments vector direction and strength for a series of important photosynthetic pigments. We obtain good agreement with first-principles and experimental results and provide insights into the detailed nature of these excitations from the time evolving populations of molecular orbitals involved as well as correlations between pigment chemistry and dipole strength.

  17. MALARIAL PIGMENT (SO-CALLED MELANIN): ITS NATURE AND MODE OF PRODUCTION.

    PubMed

    Brown, W H

    1911-02-01

    1. Two important methods for the study of malarial pigment are described. (a) A method for obtaining a solution of malarial pigment from fixed tissues without the removal of a trace of hemoglobin from the red blood corpuscles. (b) A method for obtaining an iron reaction in malarial pigment. 2. By comparing the bleach reactions and solubility of melanins and malarial pigment, the dissimilarity of the two classes of pigments has been demonstrated. 3. The spectroscopic examination of a solution of malarial pigment proves conclusively that the pigment is hematin. 4. It is suggested that the action of a proteolytic enzyme of the malarial parasite upon the hemoglobin of the red blood corpuscle is the most probable mode of elaboration of malarial pigment. 5. The difficulty with which the human organism disposes of malarial pigment indicates that the production of hematin cannot be considered as a normal intermediate process in the formation of bile pigments from hemoglobin.

  18. A general method for the quantitative assessment of mineral pigments.

    PubMed

    Ares, M C Zurita; Fernández, J M

    2016-01-01

    A general method for the estimation of mineral pigment contents in different bases has been proposed using a sole set of calibration curves, (one for each pigment), calculated for a white standard base, thus elaborating patterns for each utilized base is not necessary. The method can be used in different bases and its validity had ev en been proved in strongly tinted bases. The method consists of a novel procedure that combines diffuse reflectance spectroscopy, second derivatives and the Kubelka-Munk function. This technique has proved to be at least one order of magnitude more sensitive than X-Ray diffraction for colored compounds, since it allowed the determination of the pigment amount in colored samples containing 0.5 wt% of pigment that was not detected by X-Ray Diffraction. The method can be used to estimate the concentration of mineral pigments in a wide variety of either natural or artificial materials, since it does not requiere the calculation of each pigment pattern in every base. This fact could have important industrial consequences, as the proposed method would be more convenient, faster and cheaper.

  19. Laser therapy of pigmented lesions: pro and contra.

    PubMed

    Bukvić Mokos, Zrinka; Lipozenčić, Jasna; Ceović, Romana; Stulhofer Buzina, Daška; Kostović, Krešimir

    2010-01-01

    Although frequently performed, laser removal of pigmented lesions still contains certain controversial issues. Epidermal pigmented lesions include solar lentigines, ephelides, café au lait macules and seborrheic keratoses. Dermal lesions include melanocytic nevi, blue nevi, drug induced hyperpigmentation and nevus of Ota and Ito. Some lesions exhibit both an epidermal and dermal component like Becker's nevus, postinflammatory hyperpigmentations, melasma and nevus spilus. Due to the wide absorption spectrum of melanin (500-1100 nm), several laser systems are effective in removal of pigmented lesions. These lasers include the pigmented lesion pulsed dye laser (510 nm), the Q-switched ruby laser (694 nm), the Q-switched alexandrite laser (755 nm) and the Q-switched Nd:YAG laser (1064 nm), which can be frequency-doubled to produce visible green light with a wavelength of 532 nm. The results of laser therapy are usually successful. However, there are still many controversies regarding the use of lasers in treating certain pigmented lesions. Actually, the essential question in removing pigmented lesions with lasers is whether the lesion has atypical features or has a malignant potential. Dermoscopy, used as a routine first-level diagnostic technique, is helpful in most cases. If there is any doubt whether the lesion is benign, then a biopsy for histologic evaluation is obligatory.

  20. Analysis of Minoan white pigments used on pottery from Palaikastro

    NASA Astrophysics Data System (ADS)

    Swann, Charles P.; Ferrence, Susan; Betancourt, Phlip P.

    2000-03-01

    Previous analyses of Early Minoan (ca. 2200-2000 BC) and Middle Minoan (ca. 2000-1700 BC) white pigments from Crete have revealed a complex situation in which several different substances were used for the ornament on pottery. The technological situation and the nature of these pigments is still not fully understood. A high-magnesium paint has been tentatively identified as talc, and a high-calcium paint has been tentatively identified as calcium silicate, but the distribution of these pigments is still not known. A new program of analysis by PIXE at the Bartol Research Institute of the University of Delaware has examined several white pigments from Palaikastro, a site in Eastern Crete, with interesting results. Three different materials or mixtures of materials can be identified. None of the pigments is rich in magnesium. All of the paints tested contain substantial amounts of aluminum and silica, with a variable calcium content. One class is high in calcium, and the second is substantially lower in calcium, but both contain appreciable amounts of iron. The third substance is an iron free white pigment. The materials can be tentatively identified as mixtures of calcium silicates and aluminosilicates, probably with admixed quartz.

  1. The use of microspectrofluorimetry for the characterization of lake pigments.

    PubMed

    Claro, Ana; Melo, Maria J; Schäfer, Stephan; de Melo, J Sérgio Seixas; Pina, Fernando; van den Berg, Klaas Jan; Burnstock, Aviva

    2008-01-15

    In this paper, the potential of confocal microfluorescence spectroscopy is explored for the characterization of selected red lake pigments and paints based on alizarin, purpurin and eosin (weak, medium and strong emitters). The anthraquinone pigments have been used since ancient times by artists, and eosin lakes were used by impressionist painters. Reconstructions of artists paints based on 19th century recipes are examined. The paints were made using the lake pigments bound in a range of binding media including gum arabic, collagen, a vinyl emulsion and linseed oil. The acquisition of the spectra is rapid, with high spatial resolution and the data reliable and reproducible. Together with full emission spectra, it was possible to acquire well-resolved excitation spectra for purpurin, alizarin and eosin based colors. The present investigation suggests that micro-emission fluorescence can also be used as a semi-quantitative method for madder lake pigments, enabling the determination of purpurin lake ratio in a mixture of purpurin and alizarin, which is important for provenance studies. The data obtained with microfluorescence emission with those acquired with fiber-optic fluorimetry are compared. The spatial resolution used, 8microm, is appropriate for the analysis of individual pigments particles or aggregates in a paint film. Micro-emission molecular fluorescence proved to be a promising analytical tool to identify the presence of selected red lake pigments combined with a range of binding media.

  2. [Synthesis and characterization of mixed metal oxide pigments].

    PubMed

    Ding, Jie; Yue, Shi-juan; Liu, Cui-ge; Wei, Yong-ju; Meng, Tao; Jiang, Han-jie; Shi, Yong-zheng; Xu, Yi-zhuang; Yu, Jiang; Wu, Jin-guang

    2012-03-01

    In the present work, aluminum chloride and various soluble salts of doping ions were dissolved in water. In addition, urea and polyvinyl pyrrolidone (PVP) were also dissolved in the above aqueous solution under supersonic treatments. Then the solutions were heated to induce the hydrolysis of urea so that soluble aluminum and doping ions convert into insoluble hydroxide or carbonate gels. After calcinations, the obtained gels change to mixed metal oxide pigments whose color is related to type and concentrations of the doping ions. XRD characterization demonstrates that the diffraction patterns of the products are the same as that of alpha-alumina. Diffuse reflectance spectra of samples of the samples in UV-Vis regions show that the absorption bands for d-d transitions of the doping ions undergo considerable change as the coordinate environments change. In addition, L*, a* and b* values of the pigments were measured by using UV-Vis densitometer. SEM results indicate that the size of the pigment powders is in the range 200-300 nm. The pigments are quite stable since no evidence of dissolution was observed after the synthesized pigment is soaked for 24 hours. ICP test shows that very little amount of doped metal occurs in the corresponding filtrate. The above results suggest that these new kinds of mixed metal oxide pigments are stable, non-toxic, environmental friendly and they may be applicable in molten spinning process and provide a new chance for non-aqueous printing and dyeing industry.

  3. [Photoreceptors and visual pigments in three species of newts].

    PubMed

    Koremiak, D A; Govardovskiĭ, V I

    2013-01-01

    Photoreceptor complement and retinal visual pigments in three newt (Caudata, Salamandridae, Pleurodelinae) species (Pleurodeles waltl, Lissotriton (Triturus) vulgaris and Cynops orientalis) were studied by light mucroscopy and microspectrophotometry. Retinas of all three species contain "red" (rhodopsin/porphyropsin) rods, large and small single cones, and double cones. Large single cones and both components of double cones contain red-sensitive (presumably LWS) visual pigment whose absorbance spectrum peaks between 593 and 611 nm. Small single cones are either blue- (SWS2, maximum absorbance between 470 and 489 nm) or UV-sensitive (SWS1, maximum absorbance between 340 and 359 nm). Chromophore composition of visual pigments (A1 vs. A2) was assessed both from template fitting of absorption spectra and by the method of selective bleaching. All pigments contained a mixture of A1 (11-cis retinal) and A2 (11-cis-3,4-dehydroretinal) chromophore in the proportion depending on the species and cell type. In all cases, A2 was dominant. However, in C. orientalis rods the fraction of A1 could reach 45%, while in P. waltl and L. vulgaris cones it did not exceed 5%. Remarkably, the absorbance of the newt blue-sensitive visual pigment was shifted by up to 45 nm toward the longer wavelength, as compared with all other amphibian SWS2-pigments. We found no "green" rods typical of retinas of Anura and some Caudata (ambystomas) in the three newt species studied.

  4. Genetic Architecture of Abdominal Pigmentation in Drosophila melanogaster

    PubMed Central

    Dembeck, Lauren M.; Huang, Wen; Magwire, Michael M.; Lawrence, Faye; Lyman, Richard F.; Mackay, Trudy F. C.

    2015-01-01

    Pigmentation varies within and between species and is often adaptive. The amount of pigmentation on the abdomen of Drosophila melanogaster is a relatively simple morphological trait, which serves as a model for mapping the genetic basis of variation in complex phenotypes. Here, we assessed natural variation in female abdominal pigmentation in 175 sequenced inbred lines of the Drosophila melanogaster Genetic Reference Panel, derived from the Raleigh, NC population. We quantified the proportion of melanization on the two most posterior abdominal segments, tergites 5 and 6 (T5, T6). We found significant genetic variation in the proportion of melanization and high broad-sense heritabilities for each tergite. Genome-wide association studies identified over 150 DNA variants associated with the proportion of melanization on T5 (84), T6 (34), and the difference between T5 and T6 (35). Several of the top variants associated with variation in pigmentation are in tan, ebony, and bric-a-brac1, genes known to affect D. melanogaster abdominal pigmentation. Mutational analyses and targeted RNAi-knockdown showed that 17 out of 28 (61%) novel candidate genes implicated by the genome-wide association study affected abdominal pigmentation. Several of these genes are involved in developmental and regulatory pathways, chitin production, cuticle structure, and vesicle formation and transport. These findings show that genetic variation may affect multiple steps in pathways involved in tergite development and melanization. Variation in these novel candidates may serve as targets for adaptive evolution and sexual selection in D. melanogaster. PMID:25933381

  5. Production and chemical characterization of pigments in filamentous fungi.

    PubMed

    Souza, Patrícia Nirlane da Costa; Grigoletto, Tahuana Luiza Bim; de Moraes, Luiz Alberto Beraldo; Abreu, Lucas M; Guimarães, Luís Henrique Souza; Santos, Cledir; Galvão, Luciano Ribeiro; Cardoso, Patrícia Gomes

    2016-01-01

    Production of pigments by filamentous fungi is gaining interest owing to their use as food colourants, in cosmetics and textiles, and because of the important biological activities of these compounds. In this context, the objectives of this study were to select pigment-producing fungi, identify these fungi based on internal transcribed spacer sequences, evaluate the growth and pigment production of the selected strains on four different media, and characterize the major coloured metabolites in their extracts. Of the selected fungal strains, eight were identified as Aspergillus sydowii (CML2967), Aspergillus aureolatus (CML2964), Aspergillus keveii (CML2968), Penicillium flavigenum (CML2965), Penicillium chermesinum (CML2966), Epicoccum nigrum (CML2971), Lecanicillium aphanocladii (CML2970) and Fusarium sp. (CML2969). Fungal pigment production was influenced by medium composition. Complex media, such as potato dextrose and malt extract, favoured increased pigment production. The coloured compounds oosporein, orevactaene and dihydrotrichodimerol were identified in extracts of L. aphanocladii (CML2970), E. nigrum (CML2971), and P. flavigenum (CML2965), respectively. These results indicate that the selected fungal strains can serve as novel sources of pigments that have important industrial applications.

  6. The anti-mutagenic properties of bile pigments.

    PubMed

    Bulmer, A C; Ried, K; Blanchfield, J T; Wagner, K-H

    2008-01-01

    Bile pigments, including bilirubin and biliverdin, are endogenous compounds belonging to the porphyrin family of molecules. In the past, bile pigments and bilirubin in particular were thought of as useless by-products of heme catabolism that can be toxic if they accumulate. However, in the past 20 years, research probing the physiological relevance of bile pigments has been mounting, with evidence to suggest bile pigments possess significant antioxidant and anti-mutagenic properties. More specifically, bile pigments are potent peroxyl radical scavengers and inhibit the mutagenic effects of a number of classes of mutagens (polycyclic aromatic hydrocarbons, heterocyclic amines, oxidants). Coincidentally, persons with elevated circulating bilirubin concentrations have a reduced prevalence of cancer and cardio-vascular disease. Despite the encouraging in vitro anti-mutagenic effects of bile pigments, relatively little research has been conducted on their inhibitory capacity in bacterial and cultured cell assays of mutation, which might link the existing in vitro and in vivo observations. This is the first review to summarise the published data and it is our hope it will stimulate further research on these potentially preventative compounds.

  7. Distribution of unique red feather pigments in parrots

    PubMed Central

    McGraw, Kevin J; Nogare, Mary C

    2005-01-01

    In many birds, red, orange and yellow feathers are coloured by carotenoid pigments, but parrots are an exception. For over a century, biochemists have known that parrots use an unusual set of pigments to produce their rainbow of plumage colours, but their biochemical identity has remained elusive until recently. Here, we use high-performance liquid chromatography to survey the pigments present in the red feathers of 44 species of parrots representing each of the three psittaciform families. We found that all species used the same suite of five polyenal lipochromes (or psittacofulvins) to colour their plumage red, indicating that this unique system of pigmentation is remarkably conserved evolutionarily in parrots. Species with redder feathers had higher concentrations of psittacofulvins in their plumage, but neither feather colouration nor historical relatedness predicted the ratios in which the different pigments appeared. These polyenes were absent from blood at the time when birds were replacing their colourful feathers, suggesting that parrots do not acquire red plumage pigments from the diet, but instead manufacture them endogenously at growing feathers. PMID:17148123

  8. Production of diagnostic pigment by phenoloxidase activity of cryptococcus neoformans.

    PubMed

    Shaw, C E; Kapica, L

    1972-11-01

    Cryptococcus neoformans produces brown pigmented colonies when grown on agar media made from an extract of potatoes and carrots, broad beans (Vicia faba), or Guizotia abyssinica seeds. Since other yeasts do not produce the pigment, these media are useful as differential isolation media for C. neoformans. Similar specific pigment was produced by C. neoformans on chemically defined agar media which contained six different substrates of phenoloxidase (o-diphenol: oxygen oxidoreductase EC 1.10.3.1) an enzyme which catalyses the oxidation of o-diphenols to melanin. Substrates were incorporated singly into the media and included L-3, 4-dihydroxyphenylalanine (L-DOPA), chlorogenic acid, protocatechuic acid, catechol, norepinephrine, and 3-hydroxytyramine hydrochloride (dopamine). No pigment was produced on media without substrate. Phenoloxidase activity in (NH(4))(2)SO(4) precipitates of C. neoformans cell-free extract was assayed by measuring increases in absorbance at 480 nm produced in solutions of L-DOPA. This reaction showed oxygen uptake and was effectively inhibited by copper chelators, but not by catalase. The enzyme also oxidized the five other substrates which induced pigment formation. Electron micrographs of cells incubated in L-DOPA showed deposition of the pigment in the cell wall.

  9. 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.

  10. Mutations affecting xanthophore pigmentation in the zebrafish, Danio rerio.

    PubMed

    Odenthal, J; Rossnagel, K; Haffter, P; Kelsh, R N; Vogelsang, E; Brand, M; van Eeden, F J; Furutani-Seiki, M; Granato, M; Hammerschmidt, M; Heisenberg, C P; Jiang, Y J; Kane, D A; Mullins, M C; Nüsslein-Volhard, C

    1996-12-01

    In a large-scale screen for mutants with defects in embryonic development we identified 17 genes (65 mutants) specifically required for the development of xanthophores. We provide evidence that these genes are required for three different aspects of xanthophore development. (1) Pigment cell formation and migration (pfeffer and salz); (2) pigment synthesis (edison, yobo, yocca and brie) and (3) pigment translocation (esrom, tilsit and tofu). The number of xanthophore cells that appear in the body is reduced in embryos with mutations in the two genes, salz and pfeffer. In heterozygous and homozygous salz and pfeffer adults, the melanophore stripes are interrupted, indicating that xanthophore cells have an important function in adult melanophore pattern formation. Most other genes affect only larval pigmentation. In embryos mutant for edison, yobo, yocca and brie, differences in pteridine synthesis can be observed under UV light and by thin-layer chromatography. Homozygous mutant females of yobo show a recessive maternal effect. Embryonic development is slowed down and embryos display head and tail truncations. Xanthophores in larvae mutant in the three genes esrom, tilsit and tofu appear less spread out. In addition, these mutants display a defect in retinotectal axon pathfinding. These mutations may affect xanthophore pigment distribution within the cells or xanthophore cell shape. Mutations in seven genes affecting xanthophore pigmentation remain unclassified.

  11. Light-induced vegetative anthocyanin pigmentation in Petunia.

    PubMed

    Albert, Nick W; Lewis, David H; Zhang, Huaibi; Irving, Louis J; Jameson, Paula E; Davies, Kevin M

    2009-01-01

    The Lc petunia system, which displays enhanced, light-induced vegetative pigmentation, was used to investigate how high light affects anthocyanin biosynthesis, and to assess the effects of anthocyanin pigmentation upon photosynthesis. Lc petunia plants displayed intense purple anthocyanin pigmentation throughout the leaves and stems when grown under high-light conditions, yet remain acyanic when grown under shade conditions. The coloured phenotypes matched with an accumulation of anthocyanins and flavonols, as well as the activation of the early and late flavonoid biosynthetic genes required for flavonol and anthocyanin production. Pigmentation in Lc petunia only occurred under conditions which normally induce a modest amount of anthocyanin to accumulate in wild-type Mitchell petunia [Petunia axillaris x (Petunia axillaris x Petunia hybrida cv. 'Rose of Heaven')]. Anthocyanin pigmentation in Lc petunia leaves appears to screen underlying photosynthetic tissues, increasing light saturation and light compensation points, without reducing the maximal photosynthetic assimilation rate (A(max)). In the Lc petunia system, where the bHLH factor Leaf colour is constitutively expressed, expression of the bHLH (Lc) and WD40 (An11) components of the anthocyanin regulatory system were not limited, suggesting that the high-light-induced anthocyanin pigmentation is regulated by endogenous MYB transcription factors.

  12. Host pigments: potential facilitators of photosynthesis in coral symbioses.

    PubMed

    Dove, Sophie G; Lovell, Carli; Fine, Maoz; Deckenback, Jeffry; Hoegh-Guldberg, Ove; Iglesias-Prieto, Roberto; Anthony, Kenneth R N

    2008-11-01

    Reef-building corals occur as a range of colour morphs because of varying types and concentrations of pigments within the host tissues, but little is known about their physiological or ecological significance. Here, we examined whether specific host pigments act as an alternative mechanism for photoacclimation in the coral holobiont. We used the coral Montipora monasteriata (Forskål 1775) as a case study because it occurs in multiple colour morphs (tan, blue, brown, green and red) within varying light-habitat distributions. We demonstrated that two of the non-fluorescent host pigments are responsive to changes in external irradiance, with some host pigments up-regulating in response to elevated irradiance. This appeared to facilitate the retention of antennal chlorophyll by endosymbionts and hence, photosynthetic capacity. Specifically, net P(max) Chl a(-1) correlated strongly with the concentration of an orange-absorbing non-fluorescent pigment (CP-580). This had major implications for the energetics of bleached blue-pigmented (CP-580) colonies that maintained net P(max) cm(-2) by increasing P(max) Chl a(-1). The data suggested that blue morphs can bleach, decreasing their symbiont populations by an order of magnitude without compromising symbiont or coral health.

  13. Pigment dispersion syndrome associated with spontaneous subluxation of crystalline lens

    PubMed Central

    Veerwal, Vikas; Goyal, Jawahar Lal; Jain, Parul; Arora, Ritu

    2017-01-01

    Pigment dispersion syndrome (PDS) is an ocular condition characterized by a dispersion of iris pigment throughout the eye. This pigment is deposited in a characteristic manner on the corneal endothelium as Krukenberg's spindle, anterior surface of the iris, in the trabecular meshwork, on the lens and zonule and occasionally on the anterior hyaloid face. Even with deposition of pigment on zonular fibers, no zonular weakness, or zonular dehiscence has been reported in these cases. We report a unique case of PDS with bilateral spontaneous subluxation of crystalline lens. With characteristic findings of pigment distribution in both his eyes, the patient had concave iris configuration with heavily pigmented trabecular meshwork confirming the diagnosis of PDS. The patient had bilateral 180° temporal subluxation of crystalline lens in both his eyes. The usual cause of lens subluxation such as Marfan's Syndrome and Ehler's Danlos Syndrome was ruled out. The patient underwent right eye followed by left eye intracapsular cataract extraction with ab-interno technique with postoperative best-corrected visual acuity (BCVA) of 6/9 in both eyes. Spontaneous subluxation of crystalline lens in isolated PDS is not known to occur and has been reported by means of this case. We recommend a thorough assessment of zonular status in all cases of PDS. PMID:28298869

  14. Genetic Architecture of Abdominal Pigmentation in Drosophila melanogaster.

    PubMed

    Dembeck, Lauren M; Huang, Wen; Magwire, Michael M; Lawrence, Faye; Lyman, Richard F; Mackay, Trudy F C

    2015-05-01

    Pigmentation varies within and between species and is often adaptive. The amount of pigmentation on the abdomen of Drosophila melanogaster is a relatively simple morphological trait, which serves as a model for mapping the genetic basis of variation in complex phenotypes. Here, we assessed natural variation in female abdominal pigmentation in 175 sequenced inbred lines of the Drosophila melanogaster Genetic Reference Panel, derived from the Raleigh, NC population. We quantified the proportion of melanization on the two most posterior abdominal segments, tergites 5 and 6 (T5, T6). We found significant genetic variation in the proportion of melanization and high broad-sense heritabilities for each tergite. Genome-wide association studies identified over 150 DNA variants associated with the proportion of melanization on T5 (84), T6 (34), and the difference between T5 and T6 (35). Several of the top variants associated with variation in pigmentation are in tan, ebony, and bric-a-brac1, genes known to affect D. melanogaster abdominal pigmentation. Mutational analyses and targeted RNAi-knockdown showed that 17 out of 28 (61%) novel candidate genes implicated by the genome-wide association study affected abdominal pigmentation. Several of these genes are involved in developmental and regulatory pathways, chitin production, cuticle structure, and vesicle formation and transport. These findings show that genetic variation may affect multiple steps in pathways involved in tergite development and melanization. Variation in these novel candidates may serve as targets for adaptive evolution and sexual selection in D. melanogaster.

  15. Macular pigment and lens optical density measurements-evaluating a flicker machine with novel features

    NASA Astrophysics Data System (ADS)

    Mukherjee, Anirbaan

    Age related macular degeneration (AMD) is one of the leading causes of blindness amongst the elderly. Macular pigment (MP) in the retina has been established to protect individuals against AMD. Improving levels of MP by diet or supplements is the constant quest of clinical practitioners and researchers, thus necessitating development of instruments capable of repeatable and reliable MP measurement. Cataract, a consequence of the rising opacity levels of the lens with age is one of the other major causes of blindness in the world. Mapcatsf, a LED-based microprocessor-controlled heterochromatic flicker photometer (HFP) using photopic vision is capable of measuring the levels of MP and the opacity of the lens in terms of optical density. Test-retest measurements conducted on 83 subjects were analyzed for repeatability in macular pigment optical density (MPOD) measurements. Reliability of the lens optical density (LOD) measurements were tested and compared with those obtained at absolute scotopic thresholds for 25 individuals. A supplement study with 32 individuals both in the young (50) age groups for 6 months further established Mapcatsf's capacity to monitor changing levels of MP in individuals. As an overall outcome, high levels of repeatability and reliability were obtained in MPOD and LOD measurements establishing Mapcatsf as an instrument for use in clinical settings in the future.

  16. [A Composition Analysis Method of Mixed Pigments Based on Spectrum Expression and Independent Component Analysis].

    PubMed

    Wang, Gong-ming; Liu, Zhi-yong

    2015-06-01

    Reflectance spectrometry is a common method in composition analysis of mixed pigments. In this method, similarity is used to determine the type of basic pigments that constitute the mixed pigments. But its result may be inaccurate because it is easily influenced by a variety of basic pigments. In this study, a composition analysis method of mixed pigments based on spectrum expression and independent component analysis is proposed, and the composition of mixed pigments can be calculated accurately. First of all, the spectral information of mixed pigments is obtained with spectrometer, and is expressed as the discrete signal. After that, the spectral information of basic pigments is deduced with independent component analysis. Then, the types of basic pigments are determined by calculating the spectrum similarity between the basic pigments and known pigments. Finally, the ratios of basic pigments are obtained by solving the Kubelka-Munk equation system. In addition, the simulated spectrum data of Munsell color card is used to validate this method. The compositions of mixed pigments from three basic pigments are determined under the circumstance of normality and disturbance. And the compositions of mixture from several pigments within the set of eight basic pigments are deduced successfully. The curves of separated pigment spectrums are very similar to the curves of original pigment spectrums. The average similarity is 97.72%, and the maximum one can reach to 99.95%. The calculated ratios of basic pigments close to the original one. It can be seen that this method is suitable for composition analysis of mixed pigments.

  17. Grey hair: clinical investigation into changes in hair fibres with loss of pigmentation in a photoprotected population.

    PubMed

    Kaplan, P D; Polefka, T; Grove, G; Daly, S; Jumbelic, L; Harper, D; Nori, M; Evans, T; Ramaprasad, R; Bianchini, R

    2011-04-01

    Loss of pigmentation in hair fibres is one of the most obvious phenotypic changes with ageing and has been a topic of increasing interest in the study of follicle biology. The onset of greying brings cosmetic complaints that grey fibres are wild or difficult to manage. Of course, these perceptions may be the consequence of visual obviousness rather than underlying physical or chemical differences. Although several studies have compared pigmented and unpigmented fibres, few have tried to control genetic and ethnic difference as well as extrinsic factors such as photoexposure and chemical treatment. We have recruited subjects with salt-and-pepper hair from a population of Old Order Mennonites who, for cultural reasons, are not only prohibited from chemically treating their hair but also limit their exposure to sunlight. Hair samples were examined for elemental composition, surface energy, Young's modulus, break stress, bending modulus, shear modulus and water sorption/desorption isotherm. The parameters were evaluated statistically for global differences, individual differences and typical individual differences. Consistent with previous published literature, few global differences were found between pigmented and unpigmented hair across the population. We do find that many individual subjects had differences between pigmented and unpigmented fibres. These differences tend to be more pronounced in bulk than in surface properties. The small differences in mechanical properties and moisture uptake and loss lend support to the perception by consumers that grey hair is wilder, drier and less manageable.

  18. Clinical value of diascopy and other non-invasive techniques on differential diagnosis algorithms of oral pigmentations: A systematic review

    PubMed Central

    Pena-Cristóbal, Maite; Otero-Rey, Eva-María; Tomás, Inmaculada; Blanco-Carrión, Andrés

    2016-01-01

    Objectives To determine the diagnostic value of diascopy and other non-invasive clinical aids on recent differential diagnosis algorithms of oral mucosal pigmentations affecting subjects of any age. Material and Methods Data Sources: this systematic review was conducted by searching PubMed, Scopus, Dentistry & Oral Sciences Source and the Cochrane Library (2000-2015); Study Selection: two reviewers independently selected all types of English articles describing differential diagnosis algorithms of oral pigmentations and checked the references of finally included papers; Data Extraction: one reviewer performed the data extraction and quality assessment based on previously defined fields while the other reviewer checked their validity. Results Data Synthesis: eight narrative reviews and one single case report met the inclusion criteria. Diascopy was used on six algorithms (66.67%) and X-ray was included once (11.11%; 44.44% with text mentions); these were considered helpful tools in the diagnosis of intravascular and exogenous pigmentations, respectively. Surface rubbing was described once in the text (11.11%). Conclusions Diascopy was the most applied method followed by X-ray and surface rubbing. The limited scope of these procedures only makes them useful when a positive result is obtained, turning biopsy into the most recommended technique when diagnosis cannot be established on clinical grounds alone. Key words:Algorithm, differential diagnosis, flow chart, oral mucosa, oral pigmentation, systematic review. PMID:27703615

  19. Pigmented Onychomatricoma: A Rare Pigmented Nail Unit Tumor Presenting as Longitudinal Melanonychia That Has Potential for Misdiagnosis as Melanoma.

    PubMed

    Wynes, Jacob; Wanat, Karolyn A; Huen, Auris; Mlodzienski, Alan J; Rubin, Adam I

    2015-01-01

    Pigmented onychomatricoma is a rare nail unit tumor that can clinically mimic nail unit melanoma. We report the case of a 63-year-old male with new-onset longitudinal melanonychia involving his right second toe. An excisional biopsy was performed and demonstrated pigmented onychomatricoma. We present this case to alert clinicians of this rare nail unit tumor and the importance of clinicopathologic correlation to avoid misdiagnosis.

  20. Airborne particle exposure and extrinsic skin aging.

    PubMed

    Vierkötter, Andrea; Schikowski, Tamara; Ranft, Ulrich; Sugiri, Dorothea; Matsui, Mary; Krämer, Ursula; Krutmann, Jean

    2010-12-01

    For decades, extrinsic skin aging has been known to result from chronic exposure to solar radiation and, more recently, to tobacco smoke. In this study, we have assessed the influence of air pollution on skin aging in 400 Caucasian women aged 70-80 years. Skin aging was clinically assessed by means of SCINEXA (score of intrinsic and extrinsic skin aging), a validated skin aging score. Traffic-related exposure at the place of residence was determined by traffic particle emissions and by estimation of soot in fine dust. Exposure to background particle concentration was determined by measurements of ambient particles at fixed monitoring sites. The impact of air pollution on skin aging was analyzed by linear and logistic regression and adjusted for potential confounding variables. Air pollution exposure was significantly correlated to extrinsic skin aging signs, in particular to pigment spots and less pronounced to wrinkles. An increase in soot (per 0.5 × 10(-5) per m) and particles from traffic (per 475  kg per year and square km) was associated with 20% more pigment spots on forehead and cheeks. Background particle pollution, which was measured in low residential areas of the cities without busy traffic and therefore is not directly attributable to traffic but rather to other sources of particles, was also positively correlated to pigment spots on face. These results indicate that particle pollution might influence skin aging as well.

  1. Ultrastructure and migration of screening pigments in the retina of Pieris rapae L. (Lepidoptera, Pieridae).

    PubMed

    Ribi, W A

    1978-07-13

    The retinal morphology of the butterfly, Pieris rapae L., was investigated using light and electron microscopy with special emphasis on the morphology and distribution of its screening pigments. Pigment migration in pigment- and retinula cells was analysed after light-dark adaptation and after different selective chromatic adaptations. The primary pigment cells with white- to yellow-green pigments symmetrically surround the cone process and the distal half of the crystalline cone, whilst the six secondary pigment cells, around each ommatidium, contain dark brown pigment granules. The nine retinula cells in one ommatidium can be categorised into four types. Receptor cells 1-4, which have microvilli in the distal half of the ommatidium only, contain numerous dark brown pigment granules. On the basis of the pigment content and morphology of their pigment granules, two groups of cells, cells 1, 2 and cells 3, 4 can be distinguished. The four diagonally arranged cells (5-8), with rhabdomeric structures and pigments in the proximal half of the cells, contain small red pigment granules of irregular shape. The ninth cell, which has only a small number of microvilli, lacks pigment. Chromatic adaptation experiments in which the location of retinula cell pigment granules was used as a criterium reveal two UV-receptors (cells 1 and 2), two green receptors (cells 3 and 4) and four cells (5-8) containing the red screening pigment, with a yellow-green sensitivity.

  2. 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

  3. Retinal Ultrastructure of Murine Models of Dry Age-related Macular Degeneration (AMD)

    PubMed Central

    Ramkumar, Hema L.; Zhang, Jun; Chan, Chi-Chao

    2010-01-01

    Age-related macular degeneration (AMD) is the most prevalent form of irreversible blindness worldwide in the elderly population. The pathology of dry AMD consists of degeneration of photoreceptors and the RPE, lipofuscin (A2E) accumulation, and drusen formation. Mice have been widely used for generating models that simulate human AMD features for investigating the pathogenesis, treatment and prevention of the disease. Although the mouse has no macula, focal atrophy of photorecptors and RPE, lipofuscin accumulation, and increased A2E can develop in aged mouse eyes. However, drusen are rarely seen in mice because of their simpler Bruch’s membrane and different process of lipofuscin extrusion compared with humans. Thus, analyzing basal deposits at the ultrastructural level and understanding the ultrastructural pathologic differences between various mouse AMD models are critical to comprehending the significance of research findings and response to possible therapeutic options for dry AMD. Based on the multifactorial pathogenesis of AMD, murine dry AMD models can be classified into three groups. First, genetically engineered mice that target genes related to juvenile macular dystrophies are the most common models, and they include abcr−/− (Stargardt disease), transgenic ELOVL4 (Stargardt-3 dominant inheritary disease), Efemp1R345W/R345W (Doyne honeycomb retinal dystrophy), and Timp3S156C/S156C (Sorsby fundus dystrophy) mice. Other murine models target genes relevant to AMD, including inflammatory genes such as Cfh−/−, Ccl2−/−, Ccr2−/−, Cx3cr1−/−, and Ccl2−/−/cx3cr1−/−, oxidative stress associated genes such as Sod1−/− and Sod2 knockdown, metabolic pathway genes such as neprilysin −/− (amyloid β), transgenic mcd/mcd (cathepsin D), Cp−/−/Heph−/Y (ferroxidase ceruloplasmin/hepaestin, iron metabolism), and transgenic ApoE4 on high fat and high cholesterol diet (lipid metabolism). Second, mice have also been immunologically

  4. Dermoscopic Features of Pigmented Bowen's Disease in a Japanese Female Mimicking Malignant Melanoma

    PubMed Central

    Inoue, Takayuki; Kobayashi, Ken; Sawada, Mizuki; Ishizaki, Sumiko; Ito, Haruo; Fujibayashi, Mariko; Tanaka, Masaru

    2010-01-01

    Various structures have been reported for dermoscopic features of pigmented Bowen's disease (BD), which could be a mimic of various pigmented skin lesions. A 79-year-old Japanese woman presented with a 3-year history of brown-black macule on her right upper arm without symptom. Dermoscopic examination demonstrated irregular flossy streaks, irregular brown dots/globules, blue-whitish regression structures, and overlaying whitish scaly areas. We suspected pigmented skin lesions including seborrheic keratosis, pigmented eccrine poroma, and malignant melanoma and excised completely with a 5 mm margin. Histopathological features were consistent with a diagnosis of pigmented BD. Although similar dermoscopic features might be revealed in pigmented skin lesions and it may occasionally be difficult to distinguish between pigmented BD and other pigmented skin lesions, dermoscopy would be useful in speculating pathologic features of pigmented BD. PMID:20811602

  5. Coral Pigments: Quantification Using HPLC and Detection by Remote Sensing

    NASA Technical Reports Server (NTRS)

    Cottone, Mary C.

    1995-01-01

    Widespread coral bleaching (loss of pigments of symbiotic dinoflagellates), and the corresponding decline in coral reef health worldwide, mandates the monitoring of coral pigmentation. Samples of the corals Porites compressa and P. lobata were collected from a healthy reef at Puako, Hawaii, and chlorophyll (chl) a, peridinin, and Beta-carotene (Beta-car) were quantified using reverse-phase high performance liquid chromatography (HPLC). Detailed procedures are presented for the extraction of the coral pigments in 90% acetone, and the separation, identification, and quantification of the major zooxanthellar pigments using spectrophotometry and a modification of the HPLC system described by Mantoura and Llewellyn (1983). Beta-apo-8-carotenal was found to be inadequate as in internal standard, due to coelution with chl b and/or chl a allomer in the sample extracts. Improvements are suggested, which may result in better resolution of the major pigments and greater accuracy in quantification. Average concentrations of peridinin, chl a, and Beta-car in corals on the reef were 5.01, 8.59, and 0.29, micro-grams/cm(exp 2), respectively. Average concentrations of peridinin and Beta-car did not differ significantly between the two coral species sampled; however, the mean chl a concentration in P. compressa specimens (7.81 ,micro-grams/cm(exp 2) was significantly lower than that in P. lobata specimens (9.96 11g/cm2). Chl a concentrations determined spectrophotometrically were significantly higher than those generated through HPLC, suggesting that spectrophotometry overestimates chl a concentrations. The average ratio of chl a-to-peridinin concentrations was 1.90, with a large (53%) coefficient of variation and a significant difference between the two species sampled. Additional data are needed before conclusions can be drawn regarding average pigment concentrations in healthy corals and the consistency of the chl a/peridinin ratio. The HPLC pigment concentration values

  6. Health-Promoting Compounds in Pigmented Thai and Wild Rice

    PubMed Central

    Melini, Valentina; Acquistucci, Rita

    2017-01-01

    Organic pigmented Thai rice and wild rice are commonly available in specialized Italian markets and food shops, and they are gaining popularity among consumers demanding healthy foods. Indeed, the typical colour of kernels, which is the unique characteristic of pigmented cereals, is due to the accumulation of pigments that are also responsible for a number of healthy effects. The aim of this study was to provide a portrait of two organic pigmented Thai rice varieties from Thailand and one wild rice variety from Canada, imported into Italy and at Italian consumers’ disposal. To this end, the proximate composition and the content of health-promoting compounds, such as carotenoids, anthocyanins and phenolic compounds, were determined in Thai and wild rice. Moreover, the effect of cooking on phytochemicals was assessed, in order to provide reliable data on the dietary intake of bioactive compounds by samples under investigation. Results show that studied samples have a content of phytochemicals higher than white rice and comparable to other cereals. The cooking process determined a decrease of bioactive compounds in all varieties under investigation. However, some samples were found more resistant to cooking stress, and some phytochemicals were little affected by this process. Therefore, pigmented Thai and wild rice may represent a valuable source of healthy compounds and an alternative to other wholesome foods required by consumers. PMID:28231088

  7. Group B streptococcal haemolysin and pigment, a tale of twins

    PubMed Central

    Rosa-Fraile, Manuel; Dramsi, Shaynoor; Spellerberg, Barbara

    2014-01-01

    Group B streptococcus [(GBS or Streptococcus agalactiae)] is a leading cause of neonatal meningitis and septicaemia. Most clinical isolates express simultaneously a β-haemolysin/cytolysin and a red polyenic pigment, two phenotypic traits important for GBS identification in medical microbiology. The genetic determinants encoding the GBS haemolysin and pigment have been elucidated and the molecular structure of the pigment has been determined. The cyl operon involved in haemolysin and pigment production is regulated by the major two-component system CovS/R, which coordinates the expression of multiple virulence factors of GBS. Genetic analyses indicated strongly that the haemolysin activity was due to a cytolytic toxin encoded by cylE. However, the biochemical nature of the GBS haemolysin has remained elusive for almost a century because of its instability during purification procedures. Recently, it has been suggested that the haemolytic and cytolytic activity of GBS is due to the ornithine rhamnopolyenic pigment and not to the CylE protein. Here we review and summarize our current knowledge of the genetics, regulation and biochemistry of these twin GBS phenotypic traits, including their functions as GBS virulence factors. PMID:24617549

  8. Study of a melanic pigment of Proteus mirabilis.

    PubMed

    Agodi, A; Stefani, S; Corsaro, C; Campanile, F; Gribaldo, S; Sichel, G

    1996-01-01

    The present study sought to determine whether the pigment produced by Proteus mirabilis from the L-forms of various aromatic amino acids under aerobic conditions is melanic in nature. It is a black-brown pigment which behaves like a melanin in many respects, namely solubility features, bleaching by oxidizing agents and positive response to the Fontana-Masson assay. In the present study, for the first time, it was shown by electron spin resonance analysis that a bacterial melanin is able to act as a free radical trap, as was previously demonstrated for other melanins. Scanning electron microscopy studies showed a specific organized structure of the pigment as rounded aggregates of spherical bodies. DNA hybridization data did not reveal, in the P. mirabilis genome, any nucleotide sequence related to Shewanella colwelliana mel A, one of the two melanogenesis systems already defined at the molecular level in bacteria. Results obtained from experiments on pigment production inhibition suggest a possible role of tyrosinase in P. mirabilis melanogenesis. In conclusion, from the bulk of our results, it appears that the pigment produced by P. mirabilis is melanic in nature.

  9. Adaptive divergence in pigment composition promotes phytoplankton biodiversity.

    PubMed

    Stomp, Maayke; Huisman, Jef; De Jongh, Floris; Veraart, Annelies J; Gerla, Daan; Rijkeboer, Machteld; Ibelings, Bas W; Wollenzien, Ute I A; Stal, Lucas J

    2004-11-04

    The dazzling diversity of the phytoplankton has puzzled biologists for decades. The puzzle has been enlarged rather than solved by the progressive discovery of new phototrophic microorganisms in the oceans, including picocyanobacteria, pico-eukaryotes, and bacteriochlorophyll-based and rhodopsin-based phototrophic bacteria. Physiological and genomic studies suggest that natural selection promotes niche differentiation among these phototrophic microorganisms, particularly with respect to their photosynthetic characteristics. We have analysed competition for light between two closely related picocyanobacteria of the Synechococcus group that we isolated from the Baltic Sea. One of these two has a red colour because it contains the pigment phycoerythrin, whereas the other is blue-green because it contains high contents of the pigment phycocyanin. Here we report theory and competition experiments that reveal stable coexistence of the two picocyanobacteria, owing to partitioning of the light spectrum. Further competition experiments with a third marine cyanobacterium, capable of adapting its pigment composition, show that this species persists by investing in the pigment that absorbs the colour not used by its competitors. These results demonstrate the adaptive significance of divergence in pigment composition of phototrophic microorganisms, which allows an efficient utilization of light energy and favours species coexistence.

  10. Mechanism and clinical significance of prostaglandin-induced iris pigmentation.

    PubMed

    Stjernschantz, Johan W; Albert, Daniel M; Hu, Dan-Ning; Drago, Filippo; Wistrand, Per J

    2002-08-01

    The new glaucoma drugs latanoprost, isopropyl unoprostone, travoprost, and bimatoprost cause increased pigmentation of the iris in some patients. The purpose of the present article is to survey the available preclinical and clinical data on prostaglandin-induced iris pigmentation and to assess the phenomenon from a clinical perspective. Most of the data have been obtained with latanoprost, and it appears that there is a predisposition to latanoprost-induced iris pigmentation in individuals with hazel or heterochromic eye color. As latanoprost and travoprost are selective agonists for the prostaglandin F(2alpha) receptor, it is likely that the phenomenon is mediated by this receptor. Several studies indicate that latanoprost stimulates melanogenesis in iridial melanocytes, and transcription of the tyrosinase gene is upregulated. The safety aspects of latanoprost-induced iris pigmentation have been addressed in histopathologic studies, and no evidence of harmful consequences of the side effect has been found. Although a final assessment of the clinical significance of prostaglandin-induced iris pigmentation currently is impossible to make, it appears that the only clear-cut disadvantage is a potential heterochromia between the eyes in unilaterally treated patients because the heterochromia is likely to be permanent, or very slowly reversible.

  11. Algal pigments in Southern Ocean abyssal foraminiferans indicate pelagobenthic coupling

    NASA Astrophysics Data System (ADS)

    Cedhagen, Tomas; Cheah, Wee; Bracher, Astrid; Lejzerowicz, Franck

    2014-10-01

    The cytoplasm of four species of abyssal benthic foraminiferans from the Southern Ocean (around 51°S; 12°W and 50°S; 39°W) was analysed by High Performance Liquid Chromatography (HPLC) and found to contain large concentrations of algal pigments and their degradation products. The composition of the algal pigments in the foraminiferan cytoplasm reflected the plankton community at the surface. Some foraminiferans contained high ratios of chlorophyll a/degraded pigments because they were feeding on fresher phytodetritus. Other foraminiferans contained only degraded pigments which shows that they utilized degraded phytodetritus. The concentration of algal pigment and corresponding degradation products in the foraminiferan cytoplasm is much higher than in the surrounding sediment. It shows that the foraminiferans collect a diluted and sparse food resource and concentrate it as they build up their cytoplasm. This ability contributes to the understanding of the great quantitative success of foraminiferans in the deep sea. Benthic foraminiferans are a food source for many abyssal metazoans. They form a link between the degraded food resources, phytodetritus, back to the active metazoan food chains.

  12. Anticorrosion Properties of Pigments based on Ferrite Coated Zinc Particles

    NASA Astrophysics Data System (ADS)

    Benda, P.; Kalendová, A.

    The paper deals with a new anticorrosion pigment, synthesized on a core-shell basis. For its syntheses a starting substance is used that forms the lamellar shaped core; namely lamellar zinc. The cover of the core is represented by zinc oxide, which is in fact partly oxidized lamellar zinc core, and is created during the calcination of the pigment. The compound that forms the top layer of the core, a ferrite, is also formed during calcination. The formula for the prepared pigment is then defined as MexZn1-xFe2O4/Zn and the formula of thin ferrite layer is MexZn1-xFe2O4 (where Me = Ca, Mg). Due to its shape, this anticorrosion pigment includes another anticorrosion effect, the so called "barrier effect". The mechanisms of anticorrosion effect, corrosion efficiency and mechanical properties were investigated for epoxy-ester paint systems with 10%pigment volume concentration (PVC). Mechanical tests were performed to determine the adhesiveness and mechanical resistance of paints and accelerated corrosion tests were carried out to evaluate efficiency against chemical degradation factors.

  13. Seeking carotenoid pigments in amber-preserved fossil feathers

    NASA Astrophysics Data System (ADS)

    Thomas, Daniel B.; Nascimbene, Paul C.; Dove, Carla J.; Grimaldi, David A.; James, Helen F.

    2014-06-01

    Plumage colours bestowed by carotenoid pigments can be important for visual communication and likely have a long evolutionary history within Aves. Discovering plumage carotenoids in fossil feathers could provide insight into the ecology of ancient birds and non-avian dinosaurs. With reference to a modern feather, we sought chemical evidence of carotenoids in six feathers preserved in amber (Miocene to mid-Cretaceous) and in a feather preserved as a compression fossil (Eocene). Evidence of melanin pigmentation and microstructure preservation was evaluated with scanning electron and light microscopies. We observed fine microstructural details including evidence for melanin pigmentation in the amber and compression fossils, but Raman spectral bands did not confirm the presence of carotenoids in them. Carotenoids may have been originally absent from these feathers or the pigments may have degraded during burial; the preservation of microstructure may suggest the former. Significantly, we show that carotenoid plumage pigments can be detected without sample destruction through an amber matrix using confocal Raman spectroscopy.

  14. Comparison of pigment content of paint samples using spectrometric methods.

    PubMed

    Trzcińska, Beata; Kowalski, Rafał; Zięba-Palus, Janina

    2014-09-15

    The aim of the paper was to evaluate the influence of pigment concentration and its distribution in polymer binder on the possibility of colour identification and paint sample comparison. Two sets of paint samples: one containing red and another one green pigment were prepared. Each set consisted of 13 samples differing gradually in the concentration of pigment. To obtain the sets of various colour shades white paint was mixed with the appropriate pigment in the form of a concentrated suspension. After solvents evaporation the samples were examined using spectrometric methods. The resin and main filler were identified by IR method. Colour and white pigments were identified on the base of Raman spectra. Colour of samples were compared based on Vis spectrometry according to colour theory. It was found that samples are homogenous (parameter measuring colour similarity ΔE<3). The values of ΔE between the neighbouring samples in the set revealed decreasing linear function and between the first and following one--a logarithmic function.

  15. Photosynthetic pigments of oceanic Chlorophyta belonging to prasinophytes clade VII.

    PubMed

    Lopes Dos Santos, Adriana; Gourvil, Priscillia; Rodríguez, Francisco; Garrido, José Luis; Vaulot, Daniel

    2016-02-01

    The ecological importance and diversity of pico/nanoplanktonic algae remains poorly studied in marine waters, in part because many are tiny and without distinctive morphological features. Amongst green algae, Mamiellophyceae such as Micromonas or Bathycoccus are dominant in coastal waters while prasinophytes clade VII, yet not formerly described, appear to be major players in open oceanic waters. The pigment composition of 14 strains representative of different subclades of clade VII was analyzed using a method that improves the separation of loroxanthin and neoxanthin. All the prasinophytes clade VII analyzed here showed a pigment composition similar to that previously reported for RCC287 corresponding to pigment group prasino-2A. However, we detected in addition astaxanthin for which it is the first report in prasinophytes. Among the strains analyzed, the pigment signature is qualitatively similar within subclades A and B. By contrast, RCC3402 from subclade C (Picocystis) lacks loroxanthin, astaxanthin, and antheraxanthin but contains alloxanthin, diatoxanthin, and monadoxanthin that are usually found in diatoms or cryptophytes. For subclades A and B, loroxanthin was lowest at highest light irradiance suggesting a light-harvesting role of this pigment in clade VII as in Tetraselmis.

  16. Pigmented lesions of the nail unit: clinical and histopathologic features.

    PubMed

    Ruben, Beth S

    2010-09-01

    Probably the most common reason to perform biopsy of the nail unit is for the evaluation of irregular pigmentation, especially longitudinal melanonychia or pigmented bands. When narrow and solitary, these are usually the product of melanocytic activation/hypermelanosis, lentigines, or melanocytic nevi. Multiple pigmented bands are generally a benign finding, the result of melanocytic activation, as seen in racial pigmentation in darker-skinned patients, for example. In the context of an irregular, broad, heterogeneous or "streaky" band, the chief concern is the exclusion of subungual melanoma. Before assessing the histologic features of any such entities, it is important to understand the normal nail anatomy and melanocytic density of nail unit epithelium, as well as the type of specimen submitted, and whether it is adequate to undertake a proper histologic evaluation. The criteria for diagnosis and prognosis of melanoma of the nail unit are still evolving, and a variety of factors must be weighed in the balance to make a correct diagnosis. The importance of the clinical context cannot be overemphasized. There are also nonmelanocytic conditions to be considered that may produce worrisome nail discoloration, such as subungual hemorrhage, squamous cell carcinoma, and pigmented onychomycosis.

  17. Changes in chloroplast pigments of olive varieties during fruit ripening.

    PubMed

    Roca, M; Mínguez-Mosquera, M I

    2001-02-01

    Changes in chlorophyll and carotenoid pigments of five olive (Olea europaea L.) varieties destined for milling were investigated at six consecutive ripening stages. There was a manifest dependence between olive variety, moment of picking, and chloroplast pigment composition of the fruits. Although the content of chlorophylls and carotenoids differed with fruit variety, ripening always involved their gradual loss, which becames more pronounced with increased presence of anthocyanin compounds. The relative rates of disappearance of chlorophylls and carotenoids were markedly different between varieties, implying that the catabolism of these pigments takes place at a relative rate inherent to each variety. The varieties less rich in pigments showed the most extreme behavior. The highest relative rate of disappearance was observed in fruits of the Blanqueta variety, and the lowest was observed in those of Arbequina. The chlorophyll a/chlorophyll b ratio remained practically constant during ripening, with a value very similar for Hojiblanca, Picual, Cornicabra, and Blanqueta, but much higher for Arbequina, implying that the structure of the photosynthetic apparatus is different in the latter variety. In the five varieties studied, lutein was the slowest carotenoid to be degraded, so that its percentage in the fruits increased with ripening, whereas beta-carotene was the fastest to disappear. In ripe fruits covered with anthocyanins, chloroplast pigments were retained in both skin and pulp, with the rate of disappearance being much higher in the latter.

  18. Spectral absorption of visual pigments in stomatopod larval photoreceptors.

    PubMed

    Feller, Kathryn D; Cronin, Thomas W

    2016-03-01

    Larval stomatopod eyes appear to be much simpler versions of adult compound eyes, lacking most of the visual pigment diversity and photoreceptor specializations. Our understanding of the visual pigment diversity of larval stomatopods, however, is based on four species, which severely limits our understanding of stomatopod eye ontogeny. To investigate several poorly understood aspects of stomatopod larval eye function, we tested two hypotheses surrounding the spectral absorption of larval visual pigments. First, we examined a broad range of species to determine if stomatopod larvae generally express a single, spectral class of photoreceptor. Using microspectrophotometry (MSP) on larvae captured in the field, we found data which further support this long-standing hypothesis. MSP was also used to test whether larval species from the same geographical region express visual pigments with similar absorption spectra. Interestingly, despite occupation of the same geographical location, we did not find evidence to support our second hypothesis. Rather, there was significant variation in visual pigment absorption spectra among sympatric species. These data are important to further our understanding of larval photoreceptor spectral diversity, which is beneficial to ongoing investigations into the ontogeny, physiology, and molecular evolution of stomatopod eyes.

  19. Age-related changes in the inner zone of the adrenal cortex of the rat--a morphologic and biochemical study.

    PubMed

    de Almeida, H; Magalhães, M C; Magalhães, M M

    1998-09-15

    In this work, a correlative morphologic and biochemical study on the effects of ageing on the rat adrenal Inner Zone (IZ) was made. Male Wistar rats were studied at 2, 6, 12, 18 and 24 months. Structural data of Zona Fasciculata (ZF) showed age-related increase in cell volume (P < 0.05), decrease in mitochondria (P < 0.01) and smooth endoplasmic reticulum (SER) volumes, and increase in lipid droplets (P < 0.01) and lipofuscin granules (P < 0.01) volumes. In Zona Reticularis, the main change observed was the increase in lipofuscin granules (P < 0.001). Serum corticosterone from unstimulated rats increased until 12 months but decreased thereafter (P < 0.01), to levels below those from 2-month-old rats. Similarly, plasma adrenocorticotrophic hormone (ACTH) presented a maximum at 12 months, followed by a decrease to levels higher than at 2 months (P < 0.05). In rats injected either with only ACTH or dexamethasone, before ACTH stimulation, corticosterone level had a maximum at 12 months. In aged rats, serum high density lipoprotein (HDL) and adrenal cholesterol ester increased significantly (P < 0.05 and P < 0.01, respectively), whereas adrenal corticosterone decreased. Products of lipid peroxidation, assayed with the thiobarbituric acid reaction and fluorimetry showed an age-related increase (P < 0.05). The age-related decrease in mitochondria and SER volumes is consistent with the decrease of serum corticosterone. The increase in lipid droplet and HDL and the reduction of adrenal corticosterone level correlate with the increase of adrenal cholesterol ester content. These suggest a continued uptake of steroid precursor but a reduced steroid synthesis. On the whole, the data provide evidence for an age-related reduced functional ability of IZ and particularly of ZF.

  20. Reduced Number of Pigmented Neurons in the Substantia Nigra of Dystonia Patients? Findings from Extensive Neuropathologic, Immunohistochemistry, and Quantitative Analyses

    PubMed Central

    Iacono, Diego; Geraci-Erck, Maria; Peng, Hui; Rabin, Marcie L.; Kurlan, Roger

    2015-01-01

    Background Dystonias (Dys) represent the third most common movement disorder after essential tremor (ET) and Parkinson's disease (PD). While some pathogenetic mechanisms and genetic causes of Dys have been identified, little is known about their neuropathologic features. Previous neuropathologic studies have reported generically defined neuronal loss in various cerebral regions of Dys brains, mostly in the basal ganglia (BG), and specifically in the substantia nigra (SN). Enlarged pigmented neurons in the SN of Dys patients with and without specific genetic mutations (e.g., GAG deletions in DYT1 dystonia) have also been described. Whether or not Dys brains are associated with decreased numbers or other morphometric changes of specific neuronal types is unknown and has never been addressed with quantitative methodologies. Methods Quantitative immunohistochemistry protocols were used to estimate neuronal counts and volumes of nigral pigmented neurons in 13 SN of Dys patients and 13 SN of age-matched control subjects (C). Results We observed a significant reduction (∼20%) of pigmented neurons in the SN of Dys compared to C (p<0.01). Neither significant volumetric changes nor evident neurodegenerative signs were observed in the remaining pool of nigral pigmented neurons in Dys brains. These novel quantitative findings were confirmed after exclusion of possible co-occurring SN pathologies including Lewy pathology, tau-neurofibrillary tangles, β-amyloid deposits, ubiquitin (ubiq), and phosphorylated-TAR DNA-binding protein 43 (pTDP43)-positive inclusions. Discussion A reduced number of nigral pigmented neurons in the absence of evident neurodegenerative signs in Dys brains could indicate previously unconsidered pathogenetic mechanisms of Dys such as neurodevelopmental defects in the SN. PMID:26069855

  1. Vertical distribution of pigmented and non-pigmented nanoflagellates in the East China Sea

    NASA Astrophysics Data System (ADS)

    Tsai, Sheng-Fang; Lin, Fan-Wei; Chan, Ya-Fan; Chiang, Kuo-Ping

    2016-08-01

    Nanoflagellates can be separated into two groups according to their trophic mode, i.e. pigmented nanoflagellates (PNF) and heterotrophic nanoflagellates (HNF). However, a newly identified group, mixotrophic nanoflagellates (MNF), are pigmented and show the ability of prey on bacteria. To examine the vertical variations in PNF and HNF abundances, as well as their relationships and the nutritional strategies that they might use, two summer cruises were undertaken in the East China Sea in July 2011 (OR1 966) and July 2012 (OR1 1004). The results show that both HNF and PNF abundances decline with increasing water depth. Vertical variations of abundances are believed to be influenced by prey and light, for HNF and PNF respectively. Over a large part of the sampling area, the ratio of PNF to HNF abundances is about 1:1 in the disphotic and euphotic zones, but exceeds 1.5 in the nutrient-depleted environment along the margin of the continental shelf. The correlation between PNF abundance and bacteria/Synechococcus abundance is positive where PNF/HNF >1.5. However, there is no significant correlation between PNF/HNF abundance when PNF/HNF >1.5 and light/nutrients, indicating that vertical distributions are influenced mainly by prey (bacteria and Synechococcus) in the nutrient-depleted environment. This study assumes that PNF consists mostly of MNF. In the euphotic zone they receive energy from photosynthesis, which is stimulated by the available nutrients from grazing. Their abundance is thus higher than that of HNF. However, in the disphotic zone, both PNF and HNF satisfy their nutrient demands by grazing, and PNF/HNF is close to 1. In other words, mixotrophy might be the main trophic mode for PNF in the nutrient-depleted, oligotrophic environment. Meanwhile, in deeper water (300 m), the much lower prey density means that MNF cannot satisfy the basic energy demands of metabolism and photosynthesis, and thus HNF abundance exceeds that of PNF.

  2. Genetics Home Reference: vitelliform macular dystrophy

    MedlinePlus

    ... faces. Vitelliform macular dystrophy causes a fatty yellow pigment (lipofuscin) to build up in cells underlying the ... structures in these cells that contain light-sensing pigments. It is unclear why PRPH2 mutations affect only ...

  3. Characterization of lapis lazuli and corresponding purified pigments for a provenance study of ultramarine pigments used in works of art.

    PubMed

    Favaro, M; Guastoni, A; Marini, F; Bianchin, S; Gambirasi, A

    2012-02-01

    In this paper, we propose an analytical methodology for attributing provenance to natural lapis lazuli pigments employed in works of art, and for distinguishing whether they are of natural or synthetic origin. A multitechnique characterization of lazurite and accessory phases in lapis lazuli stones from Afghan, Siberian and Chilean quarries, on the pigments obtained by their purification, and on synthetic ultramarine pigments was performed. According to the results obtained, infrared spectroscopy is not a suitable technique for distinguishing the provenance of lapis lazuli, but a particular absorbance band makes it relatively easy to determine whether it is of natural or synthetic origin. On the other hand, EDS elemental composition and XRD patterns show the presence of specific mineral phases associated with specific lapis lazuli sources, and can be used to distinguish the provenance of the stones as well as-albeit to a lesser extent-the corresponding purified blue pigments. In contrast, FEG-SEM observations clearly show different stone textures depending on their provenance, although these distinctive features do not persist in the corresponding pigments. PCA analyses of EDS data allow Afghan lapis lazuli stone to be distinguished from Chilean and Siberian ones, and can distinguish between the pigments resulting from their purification as well as synthetic blue ones. Although this methodology was developed using a limited number of samples, it was tested on lapis lazuli pigments collected from three paintings (from the fourteenth to sixteenth centuries) in order to perform a preliminary validation of the technique, and based on the results, the provenance of the blue pigments employed in those artworks is proposed. Finally, upon analytically monitoring the process of purifying lapis lazuli to obtain the corresponding pigments, it was found that ion-exchange reactions occur between the alkali modifiers of silicate/aluminosilicate phases and free carboxylic acids

  4. Ion beam induced luminescence analysis of painting pigments

    NASA Astrophysics Data System (ADS)

    Quaranta, A.; Salomon, J.; Dran, J. C.; Tonezzer, M.; Della Mea, G.

    2007-01-01

    Ion beam induced luminescence (IBIL) has been exploited for the first time in the analysis of inorganic painting pigments. The elemental constituents of the different compounds have been determined by particle induced X-ray emission (PIXE). The acquisition time of each spectrum ranges from 100 ms to a few seconds, depending on the luminescence intensity. The luminescence features are fingerprints of the different compounds, thus identifying the provenience of pigments of the same nominal composition. Organic varnish layers do not affect the IBIL features, allowing the identification of pigments, like lapis-lazuli, whose identification with PIXE is hindered by the varnish. IBIL proved to be a technique complementary to PIXE in the archeometry and cultural heritage analysis fields.

  5. Occupancy of the sodalite cages in the blue ultramarine pigments.

    PubMed

    Gobeltz-Hautecoeur, N; Demortier, A; Lede, B; Lelieur, J P; Duhayon, C

    2002-06-03

    A quantitative EPR study of blue ultramarine pigments has been performed in order to determine the concentration of the S(3)(-) chromophore. Copper sulfate CuSO(4) x 5H(2)O has been used as a standard, while a ruby crystal was used as an inner standard to take into account the changes of the quality factor of the cavity. These experiments show that, in the most-colored pigments, less than half of the sodalite cages are occupied by a S(3)(-) radical. In other experiments, it has been shown that the blue ultramarine pigments can be significantly modified by heating under a dynamic vacuum. The concentrations of S(3)(-) and S(2)(-), as deduced from EPR and Raman experiments, are increased after this type of treatment. These changes imply that sulfur species are transformed into S(3)(-) or S(2)(-) during this treatment. It is discussed that these sulfur species could be S(2)(-).

  6. Dermoscopy of Pigmented Bowen's Disease Mimicking Early Superficial Spreading Melanoma

    PubMed Central

    Hayashi, Yuka; Tanaka, Masaru; Suzaki, Reiko; Mori, Nuiko; Konohana, Izumi

    2009-01-01

    A 89-year-old Japanese woman presented at our clinic because of a several months’ history of an asymptomatic gradually enlarging pigmented skin lesion on the dorsum of the left foot. Physical examination revealed a single hyperpigmented oval macule of 5 mm with a rough surface. The color of the lesion was dark brown to light brown. Dermoscopic examination demonstrated atypical pigment network with small dotted vessels. Irregular streaks were also partially noted at the periphery. We suspected superficial spreading melanoma and performed an excision. The histologic features were consistent with a diagnosis of pigmented Bowen's disease. We could not completely account for dermoscopic aspects from the pathological findings of hematoxylin and eosin-stained specimens; therefore, specimens were stained with Fontana-Masson stain. It clearly demonstrated the distribution of melanin in the epidermis. We concluded that atypical network was due to an uneven melanin deposition in the variably thickened epidermal rete ridges. PMID:20652107

  7. Oral postinflammatory pigmentation: an analysis of 7 cases.

    PubMed

    Mergoni, Giovanni; Ergun, Sertan; Vescovi, Paolo; Mete, Özgür; Tanyeri, Hakkı; Meleti, Marco

    2011-01-01

    Oral postinflammatory pigmentation (OPP) is a discoloration of the oral mucosa caused by an excess of melanin production and deposition within the basal layer of the epithelium and connective tissue of areas affected by chronic inflammation. Therefore, it is mandatory to demonstrate the association with a previous or concomitant inflammatory process in the same area of oral mucosa. Clinically OPP appears as a localized or diffuse, black to brown pigmentation. OPP may persist for many years even though the disappearing of the pigmentation after the resolution of the inflammatory state has been reported. We reviewed retrospectively the medical records and, when performed, biopsy examinations of 7 cases of OPP. Four cases were associated with oral lichen planus, two cases with lichenoid lesions and one case with proliferative verrucous leukoplakia. Despite a possible high prevalence of OPP, only a few reports concerning diagnosis, etiopathogenesis and clinical manifestation have been published so far.

  8. Acral melanoma with hyperkeratosis mimicking a pigmented wart.

    PubMed

    Ise, Misaki; Yasuda, Fumiyo; Konohana, Izumi; Miura, Keiko; Tanaka, Masaru

    2013-01-01

    Acral lentiginous melanoma (ALM) of the sole sometimes has a hyperkeratotic appearance and mimics a pigmented wart. We report a case of an 81-year-old woman with an ALM on the left sole with hyperkeratosis. Due to its presentation it was difficult to make a correct diagnosis at the beginning. Finally we noticed several small, pigmented macules around the wart-like lesion with the parallel ridge pattern on dermoscopy, strongly suggesting acral melanoma. When a hyperkeratotic pigmented lesion on the sole is encountered, one should rule out melanoma by careful examination of the periphery of the lesion. Dermoscopy is a helpful adjunct for the diagnosis of an unusual case like this.

  9. Bioactive Pigments from Marine Bacteria: Applications and Physiological Roles

    PubMed Central

    Soliev, Azamjon B.; Hosokawa, Kakushi; Enomoto, Keiichi

    2011-01-01

    Research into natural products from the marine environment, including microorganisms, has rapidly increased over the past two decades. Despite the enormous difficulty in isolating and harvesting marine bacteria, microbial metabolites are increasingly attractive to science because of their broad-ranging pharmacological activities, especially those with unique color pigments. This current review paper gives an overview of the pigmented natural compounds isolated from bacteria of marine origin, based on accumulated data in the literature. We review the biological activities of marine compounds, including recent advances in the study of pharmacological effects and other commercial applications, in addition to the biosynthesis and physiological roles of associated pigments. Chemical structures of the bioactive compounds discussed are also presented. PMID:21961023

  10. A melanocortin 1 receptor allele suggests varying pigmentation among Neanderthals.

    PubMed

    Lalueza-Fox, Carles; Römpler, Holger; Caramelli, David; Stäubert, Claudia; Catalano, Giulio; Hughes, David; Rohland, Nadin; Pilli, Elena; Longo, Laura; Condemi, Silvana; de la Rasilla, Marco; Fortea, Javier; Rosas, Antonio; Stoneking, Mark; Schöneberg, Torsten; Bertranpetit, Jaume; Hofreiter, Michael

    2007-11-30

    The melanocortin 1 receptor (MC1R) regulates pigmentation in humans and other vertebrates. Variants of MC1R with reduced function are associated with pale skin color and red hair in humans of primarily European origin. We amplified and sequenced a fragment of the MC1R gene (mc1r) from two Neanderthal remains. Both specimens have a mutation that was not found in approximately 3700 modern humans analyzed. Functional analyses show that this variant reduces MC1R activity to a level that alters hair and/or skin pigmentation in humans. The impaired activity of this variant suggests that Neanderthals varied in pigmentation levels, potentially on the scale observed in modern humans. Our data suggest that inactive MC1R variants evolved independently in both modern humans and Neanderthals.

  11. Laser-generated acoustic wave studies on tattoo pigment

    NASA Astrophysics Data System (ADS)

    Paterson, Lorna M.; Dickinson, Mark R.; King, Terence A.

    1996-01-01

    A Q-switched alexandrite laser (180 ns at 755 nm) was used to irradiate samples of agar embedded with red, black and green tattoo dyes. The acoustic waves generated in the samples were detected using a PVDF membrane hydrophone and compared to theoretical expectations. The laser pulses were found to generate acoustic waves in the black and green samples but not in the red pigment. Pressures of up to 1.4 MPa were produced with irradiances of up to 96 MWcm-2 which is comparable to the irradiances used to clear pigment embedded in skin. The pressure gradient generated across pigment particles was approximately 1.09 X 1010 Pam-1 giving a pressure difference of 1.09 +/- 0.17 MPa over a particle with mean diameter 100 micrometers . This is not sufficient to permanently damage skin which has a tensile strength of 7.4 MPa.

  12. Granulomatous reaction to red tattoo pigment treated with allopurinol.

    PubMed

    Godinho, Mariana Marteleto; Aguinaga, Felipe; Grynszpan, Rachel; Lima, Victor Maselli; Azulay, David Rubem; Cuzzi, Tullia; Ramos-E-Silva, Marcia; Manela-Azulay, Mônica

    2015-09-01

    Granulomatous reactions to tattoo ink are most commonly associated with mercury sulfide, a component of red pigments. Treatment options show limited results. Allopurinol, an inhibitor of xanthine oxidase, has been reported as a successful alternative treatment to granulomatous disorders, such as sarcoidosis and granulomatous reactions to fillers and tattoos. We report a case of granulomatous reaction to red tattoo pigment treated with allopurinol for 6 months. Good clinical improvement could be noticed during this time. Two months after we stopped the treatment, the lesion recurred. Allopurinol emerges as an important drug for the management of granulomatous reactions caused by tattoo pigments. Based on the significant clinical improvement noticed during its use, we recommend new studies to elucidate all the potential benefits of the use of allopurinol for the treatment of granulomatous reactions to tattoo ink.

  13. Chemical research on red pigments after adverse reactions to tattoo.

    PubMed

    Tammaro, A; Toniolo, C; Giulianelli, V; Serafini, M; Persechino, S

    2016-03-01

    Currently, the incidence of tattooing is on the rise compared to the past, especially among adolescents, and it leads to the urgency of monitoring the security status of tattooing centers, as well as to inform people about the risks of tattoo practice. In our clinical experience, 20% of tattooed patients presented adverse reactions, like allergic contact dermatitis, psoriasis with Koebner's phenomena and granulomatous reactions, with the latter most prevalent and most often related to red pigment. Adverse reactions to tattoo pigments, especially the red one, are well known and described in literature. Great attention has to be focused on the pigments used, especially for the presence of new substances, often not well known. For this reason, we decided to perform a study on 12 samples of red tattoo ink, obtained by patients affected by different cutaneous reactions in the site of tattoo, to analyze their chemical composition.

  14. Phytoplankton pigment patterns and wind forcing off central California

    NASA Technical Reports Server (NTRS)

    Abbott, Mark R.; Barksdale, Brett

    1991-01-01

    Mesoscale variability in phytoplankton pigment distributions of central California during the spring-summer upwelling season are studied via a 4-yr time series of high-resolution coastal zone color scanner imagery. Empirical orthogonal functions are used to decompose the time series of spatial images into its dominant modes of variability. The coupling between wind forcing of the upper ocean and phytoplankton distribution on mesoscales is investigated. Wind forcing, in particular the curl of the wind stress, was found to play an important role in the distribution of phytoplankton pigment in the California Current. The spring transition varies in timing and intensity from year to year but appears to be a recurrent feature associated with the rapid onset of the upwelling-favorable winds. Although the underlying dynamics may be dominated by processes other than forcing by wind stress curl, it appears that curl may force the variability of the filaments and hence the pigment patterns.

  15. [Pigmentation of Serratia marcescens and spectral properties of prodigiosin].

    PubMed

    Andreeva, I N; Ogorodnikova, T I

    2015-01-01

    Pigmentation of Serratia marcescens depends on the composition of the cultivation medium. The cultures grown on glycerol-peptone medium and on the medium with acetate are red and yellow (yellowish orange), respectively, with the color depending on the ambient pH. S. marcescens cells growth on glycerol-peptone medium (visually of red color) contain two forms of prodigiosin: the "red" and "yellow" ones with absorption maxima at 535 and 460-470 nm, respectively. The absorption spectrum of prodigiosin in the native pigment-protein complex was different from the spectrum of the pigment dissolved in ethanol and resembled that of the cell suspension in the presence of an additional absorption maximum at 500 nm.

  16. Exogenous ammonium inhibits petal pigmentation and expansion in Gerbera hybrida.

    PubMed

    Huang, Zhigang; Liang, Minting; Peng, Jianzong; Xing, Tim; Wang, Xiaojing

    2008-06-01

    Petal pigmentation is the most important aspect in natural flower coloration. In the present study, the inhibition of petal pigmentation by exogenous ammonium was investigated. Ray floret petals detached from inflorescences of Gerbera hybrida (Shenzhen No. 5) were cultured in vitro on media supplied with different forms of nitrogen and its assimilated compounds. The expression of a set of genes involved in anthocyanin biosynthesis and regulation was determined by Northern blotting assay. It was found that ammonium (NH4+), not nitrate (NO3-), in millimolar concentrations inhibited anthocyanin accumulation. The expressions of Gerbera chalcone synthase 1 (GCHS1), Gerbera chalcone synthase 2 (GCHS2) and Gerbera dihydroflavonol-4-reductase (GDFR) decreased, while six other related genes showed no significant changes after NH4+ treatment. Further studies on NH4+ function indicated that glutamine (Gln) acted as a downstream factor of NH4+ to suppress petal pigmentation. Both exogenous Gln and NH4+ were found to inhibit anthocyanin accumulation in the petals, and the application of Gln was also found to inhibit the expressions of GCHS1, GCHS2 and GDFR. The application of NH4+ also resulted in an increase in the activity of Gerbera glutamine synthetase (EC 6.3.1.2) along with a rapid increase of Gln content. When methionine sulfoximine, an inhibitor of glutamine synthetase (GS), was added, it was found to block the NH4+-induced inhibition of pigmentation. From these experiments, we conclude that the NH4+-induced suppression of petal pigmentation is not because of NH4+ toxicity, and the inhibition of pigmentation caused by the addition of exogenous NH4+ is the result of its assimilation into Gln.

  17. Determination of the complex optical index of red pigments, vermillon

    NASA Astrophysics Data System (ADS)

    Jarrige, Raphaelle; Andraud, Christine; Lafait, Jacques; Eveno, Myriam; Menu, Michel; Diniz, Nuno

    2011-06-01

    The non-destructive analysis of works of art and more specifically the paintings with the aim of a non-ambiguous identification of their components and the understanding of the techniques of the artists still remains a challenge. The aim of our research is to elaborate a purely optical way for this identification, based on the exclusive use of the intrinsic characteristic optical parameters of the components, instead the derived parameters presently commonly used, depending on several other parameters (morphology, environment...). The approach we propose is based on the resolution of the RTE using the 4-Flux approximation, combined with the Mie theory, allowing the identification of the pigments via the spectrum of their complex optical index entered into the model via a database. The key point of this approach is the index data bank. We report in this communication one the method's crucial steps: the determination of the intrinsic optical index of pigments under the form of grains of micrometric size. This step is far from trivial and presents many difficulties that are not completely solved. This is one of the reasons why a more rigorous analysis of the paintings has not been up to now developed. We illustrate this problem with a red pigment: vermillion randomly dispersed at low concentration in a transparent polymer. The morphology of the sample is well characterized (thickness, concentration, size and dispersion of the pigments, surface roughness) as well as the index of the matrix. We use the same approach and model as presented above, applied this time to the calculation of the complex index of the pigments. The model is supposed to account for the diffuse flux and the specular flux, both measured on our samples, by spectrophotometry with an integrating sphere in the visible spectral range 400-800 nm. This resolution allows determining independently the coefficients of scattering and absorption of the pigment, which are finally related to the complex index of

  18. The Silk-protein Sericin Induces Rapid Melanization of Cultured Primary Human Retinal Pigment Epithelial Cells by Activating the NF-κB Pathway.

    PubMed

    Eidet, J R; Reppe, S; Pasovic, L; Olstad, O K; Lyberg, T; Khan, A Z; Fostad, I G; Chen, D F; Utheim, T P

    2016-03-04

    Restoration of the retinal pigment epithelial (RPE) cells to prevent further loss of vision in patients with age-related macular degeneration represents a promising novel treatment modality. Development of RPE transplants, however, requires up to 3 months of cell differentiation. We explored whether the silk protein sericin can induce maturation of primary human retinal pigment epithelial (hRPE) cells. Microarray analysis demonstrated that sericin up-regulated RPE-associated transcripts (RPE65 and CRALBP). Upstream analysis identified the NF-κB pathway as one of the top sericin-induced regulators. ELISA confirmed that sericin stimulates the main NF-κB pathway. Increased levels of RPE-associated proteins (RPE65 and the pigment melanin) in the sericin-supplemented cultures were confirmed by western blot, spectrophotometry and transmission electron microscopy. Sericin also increased cell density and reduced cell death following serum starvation in culture. Inclusion of NF-κB agonists and antagonists in the culture medium showed that activation of the NF-κB pathway appears to be necessary, but not sufficient, for sericin-induced RPE pigmentation. We conclude that sericin promotes pigmentation of cultured primary hRPE cells by activating the main NF-κB pathway. Sericin's potential role in culture protocols for rapid differentiation of hRPE cells derived from embryonic or induced pluripotent stem cells should be investigated.

  19. The Silk-protein Sericin Induces Rapid Melanization of Cultured Primary Human Retinal Pigment Epithelial Cells by Activating the NF-κB Pathway

    PubMed Central

    Eidet, J. R.; Reppe, S.; Pasovic, L.; Olstad, O. K.; Lyberg, T.; Khan, A. Z.; Fostad, I. G.; Chen, D. F.; Utheim, T. P.

    2016-01-01

    Restoration of the retinal pigment epithelial (RPE) cells to prevent further loss of vision in patients with age-related macular degeneration represents a promising novel treatment modality. Development of RPE transplants, however, requires up to 3 months of cell differentiation. We explored whether the silk protein sericin can induce maturation of primary human retinal pigment epithelial (hRPE) cells. Microarray analysis demonstrated that sericin up-regulated RPE-associated transcripts (RPE65 and CRALBP). Upstream analysis identified the NF-κB pathway as one of the top sericin-induced regulators. ELISA confirmed that sericin stimulates the main NF-κB pathway. Increased levels of RPE-associated proteins (RPE65 and the pigment melanin) in the sericin-supplemented cultures were confirmed by western blot, spectrophotometry and transmission electron microscopy. Sericin also increased cell density and reduced cell death following serum starvation in culture. Inclusion of NF-κB agonists and antagonists in the culture medium showed that activation of the NF-κB pathway appears to be necessary, but not sufficient, for sericin-induced RPE pigmentation. We conclude that sericin promotes pigmentation of cultured primary hRPE cells by activating the main NF-κB pathway. Sericin’s potential role in culture protocols for rapid differentiation of hRPE cells derived from embryonic or induced pluripotent stem cells should be investigated. PMID:26940175

  20. Characterization of Chromobacterium violaceum pigment through a hyperspectral imaging system

    PubMed Central

    2014-01-01

    In this paper, a comprehensive spatio-spectral and temporal analysis for Chromobacterium violaceum colonies is reported. A hyperspectral imaging (HSI) system is used to recover the spectral signatures of pigment production in a non-homogeneous media with high spectral resolution and high sensitivity in vivo, without destructing the sample. This non-contact sensing technique opens avenues to study the temporal growing of a specific section in the bacterial colony. Further, from a 580 [nm] and 764 [nm] spatio-spectral time series, a wild-type and mutant Chromobacterium violaceum strains are characterized. Such study provides quantitative information about kinetic parameters of pigment production and bacterial growing. PMID:24417877

  1. The ascidian pigmented sensory organs: structures and developmental programs.

    PubMed

    Esposito, R; Racioppi, C; Pezzotti, M R; Branno, M; Locascio, A; Ristoratore, F; Spagnuolo, A

    2015-01-01

    The recent advances on ascidian pigment sensory organ development and function represent a fascinating platform to get insight on the basic programs of chordate eye formation. This review aims to summarize current knowledge, at the structural and molecular levels, on the two main building blocks of ascidian light sensory organ, i.e. pigment cells and photoreceptor cells. The unique features of these structures (e.g., simplicity and well characterized cell lineage) are indeed making it possible to dissect the developmental programs at single cell resolution and will soon provide a panel of molecular tools to be exploited for a deep developmental and comparative-evolutionary analysis.

  2. 'Skin Trade': Genealogy of Anti-ageing 'Whiteness Therapy' in Colonial Medicine.

    PubMed

    Mire, Amina

    2014-01-01

    This article investigates the extent to which the emerging trend of do-it-yourself anti-ageing skin-whitening products represents a re-articulation of Western colonial concerns with environmental pollution and racial degeneracy into concern with gendered vulnerability. This emerging market is a multibillion dollar industry anchored in the USA, but expanding globally. Do-it-yourself anti-ageing skin-whitening products purport to address the needs of those looking to fight the visible signs of ageing, often promising to remove hyper-pigmented age spots from women's skin, and replace it with ageless skin, free from pigmentation. In order to contextualize the investigation of do-it-yourself anti-ageing skin-whitening practice and discourse, this article draws from the literature in colonial commodity culture, colonial tropical medicine, the contemporary anti-ageing discourse, and advertisements for anti-ageing skin-whitening products. First, it argues that the framing of the biomedicalization of ageing as a pigmentation problem caused by deteriorating environmental conditions and unhealthy lifestyle draws tacitly from European colonial concerns with the European body's susceptibility to tropical diseases, pigmentation disorders, and racial degeneration. Second, the article argues that the rise of do-it-yourself anti-ageing skin-whitening commodities that promise to whiten, brighten, and purify the ageing skin of women and frames the visible signs of ageing in terms of pigmentation pathology.

  3. UV exposure modulates hemidesmosome plasticity, contributing to long-term pigmentation in human skin.

    PubMed

    Coelho, Sergio G; Valencia, Julio C; Yin, Lanlan; Smuda, Christoph; Mahns, Andre; Kolbe, Ludger; Miller, Sharon A; Beer, Janusz Z; Zhang, Guofeng; Tuma, Pamela L; Hearing, Vincent J

    2015-05-01

    Human skin colour, ie pigmentation, differs widely among individuals, as do their responses to various types of ultraviolet radiation (UV) and their risks of skin cancer. In some individuals, UV-induced pigmentation persists for months to years in a phenomenon termed long-lasting pigmentation (LLP). It is unclear whether LLP is an indicator of potential risk for skin cancer. LLP seems to have similar features to other forms of hyperpigmentation, eg solar lentigines or age spots, which are clinical markers of photodamage and risk factors for precancerous lesions. To investigate what UV-induced molecular changes may persist in individuals with LLP, clinical specimens from non-sunburn-inducing repeated UV exposures (UVA, UVB or UVA + UVB) at 4 months post-exposure (short-term LLP) were evaluated by microarray analysis and dataset mining. Validated targets were further evaluated in clinical specimens from six healthy individuals (three LLP+ and three LLP-) followed for more than 9 months (long-term LLP) who initially received a single sunburn-inducing UVA + UVB exposure. The results support a UV-induced hyperpigmentation model in which basal keratinocytes have an impaired ability to remove melanin that leads to a compensatory mechanism by neighbouring keratinocytes with increased proliferative capacity to maintain skin homeostasis. The attenuated expression of SOX7 and other hemidesmosomal components (integrin α6β4 and plectin) leads to increased melanosome uptake by keratinocytes and points to a spatial regulation within the epidermis. The reduced density of hemidesmosomes provides supporting evidence for plasticity at the epidermal-dermal junction. Altered hemidesmosome plasticity, and the sustained nature of LLP, may be mediated by the role of SOX7 in basal keratinocytes. The long-term sustained subtle changes detected are modest, but sufficient to create dramatic visual differences in skin colour. These results suggest that the hyperpigmentation phenomenon

  4. UV exposure modulates hemidesmosome plasticity, contributing to long-term pigmentation in human skin

    PubMed Central

    Coelho, Sergio G.; Valencia, Julio C.; Yin, Lanlan; Smuda, Christoph; Mahns, Andre; Kolbe, Ludger; Miller, Sharon A.; Beer, Janusz Z.; Zhang, Guofeng; Tuma, Pamela L.; Hearing, Vincent J.

    2014-01-01

    Human skin color, i.e. pigmentation, differs widely among individuals as do their responses to various types of ultraviolet radiation (UV) and their risks of skin cancer. In some individuals UV-induced pigmentation persists for months to years in a phenomenon termed long-lasting pigmentation (LLP). It is unclear whether LLP is an indicator of potential risk for skin cancer. LLP seems to have similar features to other forms of hyperpigmentation, e.g. solar lentigines or age spots, which are clinical markers of photodamage and risk factors for precancerous lesions. To investigate what UV-induced molecular changes may persist in individuals with LLP, clinical specimens from non-sunburn-inducing repeated UV exposures (UVA, UVB or UVA+UVB) at 4 months post-exposure (short-term LLP) were evaluated by microarray analysis and dataset mining. Validated targets were further evaluated in clinical specimens from 6 healthy individuals (3 LLP+ and 3 LLP-) followed for more than 9 months (long-term LLP) who initially received a single sunburn-inducing UVA+UVB exposure. The results support a UV-induced hyperpigmentation model in which basal keratinocytes have an impaired ability to remove melanin that leads to a compensatory mechanism by neighboring keratinocytes with increased proliferative capacity to maintain skin homeostasis. The attenuated expression of SOX7 and other hemidesmosomal components (integrin α6β4 and plectin) leads to increased melanosome uptake by keratinocytes and points to a spatial regulation within the epidermis. The reduced density of hemidesmosomes provides supporting evidence for plasticity at the epidermal-dermal junction. Altered hemidesmosome plasticity, and the sustained nature of LLP, may be mediated by the role of SOX7 in basal keratinocytes. The long-term sustained subtle changes detected are modest, but sufficient to create dramatic visual differences in skin color. These results suggest that the hyperpigmentation phenomenon leading to increased

  5. Harnessing Solar Energy Using Photosynthetic and Organic Pigments

    NASA Astrophysics Data System (ADS)

    Fitzsimons, Toby Ryan

    Fossil fuels are a finite energy resource that must be supplemented or replaced by more stable forms of electrical energy. Solar technology research strives to supplement and provide eventual replacement for fossil fuel technology. This experiment focused on the use of natural pigments as photo-sensitizers in the current generation of solar cells called dye sensitized solar cells (DSSCs). Pigments from purified chlorophyll a, chlorophyll b, chlorophyll a/b, crude spinach (Spinacia oleracea) extract, phycocyanin, and chlorophyllin were used to construct DSSCs and evaluated, along with a control containing no pigment, for solar energy conversion. The anode of the solar cells consisted of titanium dioxide (TiO2) plates soaked in pigment solutions for twenty-four hours. The plates were assembled, along with an electrolyte sandwiched between cells, and a platinum-coated counter plate that functioned as the cathode. A gasket seal was placed between the plates and held together with rubber bands. The DSSCs were each tested for a maximum power (Pmax) point and a resistor was selected that corresponded to the resistance at that point. The cells were randomly placed into a power block assembly located in an environmental chamber with lighting that provided an average of 27,590 lumens at the surface of DSSCs. With appropriate resistors in place, the cells were subjected to twelve-hour days and twelve-hour nights for ten days, and measurements were recorded every ten minutes. Data were collected to obtain values for voltage in millivolts (mV), current in microamps (microA), and power in microwatts (microW), as well as beginning and ending efficiencies in converting light to usable energy. Voltages were substantially higher during the day than at night for all pigments, except for the control, indicating that the pigments functioned as DSSCs. Hence, only daytime values were used for data analysis. Voltage during the ten-day experiment ranged from 3.99 to 274 mV; current ranged

  6. Exploiting the autofluorescent properties of photosynthetic pigments for analysis of pigmentation and morphology in live Fremyella diplosiphon cells.

    PubMed

    Bordowitz, Juliana R; Montgomery, Beronda L

    2010-01-01

    Fremyella diplosiphon is a freshwater, filamentous cyanobacterium that exhibits light-dependent regulation of photosynthetic pigment accumulation and cellular and filament morphologies in a well-known process known as complementary chromatic adaptation (CCA). One of the techniques used to investigate the molecular bases of distinct aspects of CCA is confocal laser scanning microscopy (CLSM). CLSM capitalizes on the autofluorescent properties of cyanobacterial phycobiliproteins and chlorophyll a. We employed CLSM to perform spectral scanning analyses of F. diplosiphon strains grown under distinct light conditions. We report optimized utilization of CLSM to elucidate the molecular basis of the photoregulation of pigment accumulation and morphological responses in F. diplosiphon.

  7. Analytical Investigation Of Pigments, Ground Layer And Media Of Cartonnage Fragments From Greek Roman Period

    NASA Astrophysics Data System (ADS)

    Afifi, Hala. A. M.

    Some cartonnage fragments from Hawara, Fayoum Excavation were examined to identify pigments, media and grounds. It belonged to the Greek-Roman period. They were studied by X-ray diffraction (XRD), Energy dispersive X ray analysis (EDS) equipped with Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). These techniques were used to identify the composition and morphology of grounds, nature of pigments and media used in cartonnage fragments. The coarse ground layer was composed of calcite and traces of quartz. The fine ground layer used under the pigments directly was composed of calcite only. Carbon black was used as black pigment while lead oxide as red pigment, showing the influence of Roman and Greek pigments on Egyptian art in these later periods. Blue colorant was identified as cuprorivaite and yellow pigment was goethite. Animal glue was used in the four pigments as medium colored.

  8. [Effect of cyclic compounds on pigment formation in Aspergillus niger cultures].

    PubMed

    Malama, A A; Smirnova, L A

    1975-01-01

    The mycelial pigment os Asp. niger VP has been fractionated into four fractions ehose solubility is similar to melanin pigments obtained from other sources. The addition of pyrocatechol, L-aspartic, benzoic, kojic and salicylic acids to the liquid Capek medium stimulates the fungal growth but diminishes the yield of fractions of the melanin pigment from the mycelium. Cinnamic acid does not influence the growth but also decreases the yield of the pigment. DL-tyrosine stimulates the fungal growth and produces no influence on the total yield of fractions 2, 3 and 4 from the mycelial pigment. All the cyclic compounds enhance the pigmentation of the culture liquid and give rise to the formation of fractions 2 and 3 of the melanin pigment. This latter constitutes a substantial portion of the dry matter of the fungal cell. The pigment content in the mycelium is much higher than that in the culture liquid of the corresponding culture.

  9. Discrimination of Pigments of Microalgae, Bacteria and Yeasts Using Lightweight Handheld Raman Spectrometers: Prospects for Astrobiology

    NASA Astrophysics Data System (ADS)

    Jehlicka, J.; Osterrothova, K.; Nedbalova, L.; Gunde-Cimerman, N.; Oren, A.

    2014-06-01

    Handheld Raman instrumentation with 532 nm lasers can be used to distinguish carotenoids of autotrophic microalgae, purple sulfur bacteria, halophilic Archaea and pigmented yeasts. Pigments are proposed as biomarkers for astrobiology of Mars.

  10. Pigmented potato consumption improves immune response in men: a randomized controlled trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pigmented potatoes contain high concentrations of antioxidants including phenolic acids, anthocyanins and carotenoids; these bioactives have been implicated in the inhibition or prevention of cellular oxidative damage and chronic disease susceptibility. We studied the effects of pigmented potato c...

  11. Pigment developed to protect spacecraft/solar cells from Sun's harmful rays.

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A pigment (phthalocyanine) is studied at the Marshall Materials and Processes Lab. The pigment has the ability to protect spacecraft against the harmful effects of the Sun's ultraviolet rays, and to increase the efficiency and life of solar cells.

  12. Chemistry and Artists' Colors: Part III. Preparation and Properties of Artists' Pigments.

    ERIC Educational Resources Information Center

    Orna, Mary Virginia

    1980-01-01

    Describes laboratory methods for synthesizing chrome yellow, prussian blue, and phthalalocyanine blue; reviews chemical properties of artists' pigments including chemical structure and light-scattering properties; and explains how pigments are classified. (CS)

  13. Coastal zone color scanner pigment concentrations in the southern ocean and relationships to geophysical surface features

    NASA Technical Reports Server (NTRS)

    Comiso, J. C.; Mcclain, C. R.; Sullivan, C. W.; Ryan, J. P.; Leonard, C. L.

    1993-01-01

    Climatological data on the distribution of surface pigment fields in the entire southern ocean over a seasonal cycle are examined. The occurrence of intense phytoplankton blooms during austral summer months and during other seasons in different regions is identified and analyzed. The highest pigment concentrations are observed at high latitudes and over regions with water depths usually less than 600 m. Basin-scale pigment distribution shows a slightly asymmetric pattern of enhanced pigment concentrations about Antarctica, with enhanced concentrations extending to lower latitudes in the Atlantic and Indian sectors than in the Pacific sector. A general increase in pigment concentrations is evident from the low latitudes toward the Antarctic circumpolar region. Spatial relationships between pigment and archived geophysical data reveal significant correlation between pigment distributions and both bathymetry and wind stress, while general hemispheric scale patterns of pigment distributions are most coherent with the geostrophic flow of the Antarctic Circumpolar Current.

  14. Exogenous Hsp70 delays senescence and improves cognitive function in aging mice

    PubMed Central

    Bobkova, Natalia V.; Evgen’ev, Mikhail; Garbuz, David G.; Kulikov, Alexei M.; Morozov, Alexei; Samokhin, Alexander; Velmeshev, Dmitri; Medvinskaya, Natalia; Nesterova, Inna; Pollock, Andrew; Nudler, Evgeny

    2015-01-01

    Molecular chaperone Heat Shock Protein 70 (Hsp70) plays an important protective role in various neurodegenerative disorders often associated with aging, but its activity and availability in neuronal tissue decrease with age. Here we explored the effects of intranasal administration of exogenous recombinant human Hsp70 (eHsp70) on lifespan and neurological parameters in middle-aged and old mice. Long-term administration of eHsp70 significantly enhanced the lifespan of animals of different age groups. Behavioral assessment after 5 and 9 mo of chronic eHsp70 administration demonstrated improved learning and memory in old mice. Likewise, the investigation of locomotor and exploratory activities after eHsp70 treatment demonstrated a significant therapeutic effect of this chaperone. Measurements of synaptophysin show that eHsp70 treatment in old mice resulted in larger synaptophysin-immunopositive areas and higher neuron density compared with control animals. Furthermore, eHsp70 treatment decreased accumulation of lipofuscin, an aging-related marker, in the brain and enhanced proteasome activity. The potential of eHsp70 intranasal treatment to protect synaptic machinery in old animals offers a unique pharmacological approach for various neurodegenerative disorders associated with human aging. PMID:26668376

  15. Exogenous Hsp70 delays senescence and improves cognitive function in aging mice.

    PubMed

    Bobkova, Natalia V; Evgen'ev, Mikhail; Garbuz, David G; Kulikov, Alexei M; Morozov, Alexei; Samokhin, Alexander; Velmeshev, Dmitri; Medvinskaya, Natalia; Nesterova, Inna; Pollock, Andrew; Nudler, Evgeny

    2015-12-29

    Molecular chaperone Heat Shock Protein 70 (Hsp70) plays an important protective role in various neurodegenerative disorders often associated with aging, but its activity and availability in neuronal tissue decrease with age. Here we explored the effects of intranasal administration of exogenous recombinant human Hsp70 (eHsp70) on lifespan and neurological parameters in middle-aged and old mice. Long-term administration of eHsp70 significantly enhanced the lifespan of animals of different age groups. Behavioral assessment after 5 and 9 mo of chronic eHsp70 administration demonstrated improved learning and memory in old mice. Likewise, the investigation of locomotor and exploratory activities after eHsp70 treatment demonstrated a significant therapeutic effect of this chaperone. Measurements of synaptophysin show that eHsp70 treatment in old mice resulted in larger synaptophysin-immunopositive areas and higher neuron density compared with control animals. Furthermore, eHsp70 treatment decreased accumulation of lipofuscin, an aging-related marker, in the brain and enhanced proteasome activity. The potential of eHsp70 intranasal treatment to protect synaptic machinery in old animals offers a unique pharmacological approach for various neurodegenerative disorders associated with human aging.

  16. Gingival pigmentation index proposal of a new index with a brief review of current indices

    PubMed Central

    Peeran, Syed Wali; Ramalingam, Karthikeyan; Peeran, Syed Ali; Altaher, Omar Basheer; Alsaid, Fatma Mojtaba; Mugrabi, Marei Hamed

    2014-01-01

    Cosmetic expectations have increased with time and current trends speak volumes about gingival esthetics and smile designing. Gingival pigmentation especially on the labial aspect of anterior teeth has become an important component of general esthetics. Various physiologic and pathologic factors cause gingival pigmentation. The existing indices do not deal with the etiology, extent and severity of gingival pigmentation. Hence, we propose a new classification and index for gingival pigmentation to assess the treatment needs for the patient. PMID:24966785

  17. Exploration of industrially important pigments from soil fungi.

    PubMed

    Akilandeswari, P; Pradeep, B V

    2016-02-01

    The worldwide interest of the current era is to increase tendency towards the use of natural substances instead of synthetic ones. So, alternative and effective environment friendly sustainable technologies are highly needed. Due to a broad range of biological activities, fungi are considered as a significant source of pigments. Among the fungal species in the soil, the genera of Aspergillus, Fusarium, Penicillium, Paecilomyces, and Trichoderma are dominant. The pigments commonly produced by fungi belong to aromatic polyketide groups such as melanins, quinones, flavins, ankaflavin, anthraquinone, and naphthoquinone. The use of fungal pigments has benefits which comprise easy and fast growth in the cheap culture medium and different color shades being independent of weather conditions and would be useful in various industrial applications. In relation to the toxic effects of the synthetic dyes, the natural dyes are easily degradable since they cause no detrimental effects. Thus, the study of pigments produced by soil fungi has tremendous use in medical, textile coloring, food coloring, and cosmetics.

  18. Mutant laboratory mice with abnormalities in pigmentation: annotated tables.

    PubMed

    Nakamura, Motonobu; Tobin, Desmond J; Richards-Smith, Beverly; Sundberg, John P; Paus, Ralf

    2002-01-01

    Mammalian pigment cell research has recently entered a phase of significantly increased activity due largely to the exploitation of the many mutant mouse stocks that are coming on stream. Numerous transgenic, targeted mutagenesis (so-called 'knockouts'), conditional (so-called 'gene switch') and spontaneous mutant mice develop abnormal coat color phenotypes. The number of mice that exhibit such abnormalities is increasing exponentially as genetic engineering methods become routine. Since defined abnormalities in such mutant mice provide important clues to the as yet often poorly understood functional roles of many gene products, this overview includes a corresponding, annotated table of mutant mice with pigmentation alterations. These range from early developmental defects via a large array of coat color abnormalities to a melanoma metastasis model. This overview should provide helpful pointers to investigators who are looking for mouse models to explore or to compare functional activities of genes of interest and for comparing coat color phenotypes of spontaneous or genetically engineered mouse mutants with novel ones. Secondly, this review includes a table of mouse models of specific human diseases with genetically defined pigmentation abnormalities. In summary, this annotated table should serve as a useful reference for anyone interested in the molecular controls of pigmentation.

  19. Dynamic Imaging of a Pigmented Free-Floating Vitreous Cyst.

    PubMed

    Grewal, Dilraj S; Fekrat, Sharon

    2016-10-01

    The authors present an incidentally noted pigmented anterior vitreous cyst in an asymptomatic male adult. Observation was elected. Stability during the course of 2 years and mobility of the vitreous cyst using dynamic imaging are demonstrated. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:975-977.].

  20. An Improved Method for Extraction and Separation of Photosynthetic Pigments

    ERIC Educational Resources Information Center

    Katayama, Nobuyasu; Kanaizuka, Yasuhiro; Sudarmi, Rini; Yokohama, Yasutsugu

    2003-01-01

    The method for extracting and separating hydrophobic photosynthetic pigments proposed by Katayama "et al." ("Japanese Journal of Phycology," 42, 71-77, 1994) has been improved to introduce it to student laboratories at the senior high school level. Silica gel powder was used for removing water from fresh materials prior to…

  1. Effect of wavelength on cutaneous pigment using pulsed irradiation

    SciTech Connect

    Sherwood, K.A.; Murray, S.; Kurban, A.K.; Tan, O.T.

    1989-05-01

    Several reports have been published over the last two decades describing the successful removal of benign cutaneous pigmented lesions such as lentigines, cafe au lait macules' nevi, nevus of Ota, and lentigo maligna by a variety of lasers such as the excimer (351 nm), argon (488,514 nm), ruby (694 nm), Nd:YAG (1060 nm), and CO/sub 2/ (10,600 nm). Laser treatment has been applied to lesions with a range of pigment depths from superficial lentigines in the epidermis to the nevus of Ota in the reticular dermis. Widely divergent laser parameters of wavelength, pulse duration, energy density, and spotsizes have been used, but the laser parameters used to treat this range of lesions have been arbitrary, with little effort focused on defining optimal laser parameters for removal of each type. In this study, miniature black pig skin was exposed to five wavelengths (504, 590, 694, 720, and 750 nm) covering the absorption spectrum of melanin. At each wavelength, a range of energy densities was examined. Skin biopsies taken from laser-exposed sites were examined histologically in an attempt to establish whether optimal laser parameters exist for destroying pigment cells in skin. Of the five wavelengths examined, 504 nm produced the most pigment specific injury; this specificity being maintained even at the highest energy density of 7.0 J/cm2. Thus, for the destruction of melanin-containing cells in the epidermal compartment, 504 nm wavelength appears optimal.

  2. Sensory evaluation of pigmented flesh potatoes (Solanum tuberosum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pigmented potato cultivars were ranked by a consumer panel for overall acceptance, and acceptance of aroma, appear- ance, and flavor. Potatoes were analyzed for total phenolics, anthocyanins and carotenoids. Concentrations of total phenolics in yellow and purple potato cultivars were 2-fold greate...

  3. Plant Pigment Identification: A Classroom and Outreach Activity

    ERIC Educational Resources Information Center

    Garber, Kathleen C. A.; Odendaal, Antoinette Y.; Carlson, Erin E.

    2013-01-01

    Anthocyanins are a class of pigments responsible for the bright colors of many flowers, fruits, and vegetables typically resulting in shades of red, blue, and purple. Students were asked to perform an activity to enable them to identify which anthocyanin was present in one of several possible plant materials through a hands-on activity. Students…

  4. Effects of blue light on pigment biosynthesis of Monascus.

    PubMed

    Chen, Di; Xue, Chunmao; Chen, Mianhua; Wu, Shufen; Li, Zhenjing; Wang, Changlu

    2016-04-01

    The influence of different illumination levels of blue light on the growth and intracellular pigment yields of Monascus strain M9 was investigated. Compared with darkness, constant exposure to blue light of 100 lux reduced the yields of six pigments, namely, rubropunctatamine (RUM), monascorubramine (MOM), rubropunctatin (RUN), monascorubrin (MON), monascin (MS), and ankaflavin (AK). However, exposure to varying levels of blue light had different effects on pigment production. Exposure to 100 lux of blue light once for 30 min/day and to 100 lux of blue light once and twice for 15 min/day could enhance RUM, MOM, MS, and AK production and reduce RUN and MON compared with non-exposure. Exposure to 100 lux twice for 30 min/day and to 200 lux once for 45 min/day decreased the RUM, MOM, MS, and AK yields and increased the RUN and MON. Meanwhile, the expression levels of pigment biosynthetic genes were analyzed by real-time quantitative PCR. Results indicated that gene MpPKS5, mppR1, mppA, mppB, mmpC, mppD, MpFasA, MpFasB, and mppF were positively correlated with the yields of RUN and MON, whereas mppE and mppR2 were associated with RUM, MOM, MS, and AK production.

  5. Optimization of Light-Harvesting Pigment Improves Photosynthetic Efficiency.

    PubMed

    Jin, Honglei; Li, Mengshu; Duan, Sujuan; Fu, Mei; Dong, Xiaoxiao; Liu, Bing; Feng, Dongru; Wang, Jinfa; Wang, Hong-Bin

    2016-11-01

    Maximizing light capture by light-harvesting pigment optimization represents an attractive but challenging strategy to improve photosynthetic efficiency. Here, we report that loss of a previously uncharacterized gene, HIGH PHOTOSYNTHETIC EFFICIENCY1 (HPE1), optimizes light-harvesting pigments, leading to improved photosynthetic efficiency and biomass production. Arabidopsis (Arabidopsis thaliana) hpe1 mutants show faster electron transport and increased contents of carbohydrates. HPE1 encodes a chloroplast protein containing an RNA recognition motif that directly associates with and regulates the splicing of target RNAs of plastid genes. HPE1 also interacts with other plastid RNA-splicing factors, including CAF1 and OTP51, which share common targets with HPE1. Deficiency of HPE1 alters the expression of nucleus-encoded chlorophyll-related genes, probably through plastid-to-nucleus signaling, causing decreased total content of chlorophyll (a+b) in a limited range but increased chlorophyll a/b ratio. Interestingly, this adjustment of light-harvesting pigment reduces antenna size, improves light capture, decreases energy loss, mitigates photodamage, and enhances photosynthetic quantum yield during photosynthesis. Our findings suggest a novel strategy to optimize light-harvesting pigments that improves photosynthetic efficiency and biomass production in higher plants.

  6. Synthesis of Copper Pigments, Malachite and Verdigris: Making Tempera Paint

    ERIC Educational Resources Information Center

    Solomon, Sally D.; Rutkowsky, Susan A.; Mahon, Megan L.; Halpern, Erica M.

    2011-01-01

    Malachite and verdigris, two copper-based pigments, are synthesized in this experiment intended for use in a general chemistry laboratory. The preparation of egg tempera paint from malachite is also described. All procedures can be done with a magnetic stir plate, standard glassware present in any first-year laboratory, and household chemicals.…

  7. Carbon monoxide and bile pigments: surprising mediators of vascular function.

    PubMed

    Durante, William

    2002-08-01

    Heme oxygenase (HO) catalyzes the degradation of heme to CO, iron, and biliverdin. Biliverdin is subsequently metabolized to bilirubin by the enzyme biliverdin reductase. Although long considered irrelevant byproducts of heme catabolism, recent studies indicate that CO and the bile pigments biliverdin and bilirubin may play an important physiological role in the circulation. The release of CO by vascular cells may modulate blood flow and blood fluidity by inhibiting vasomotor tone, smooth muscle cell proliferation, and platelet aggregation. CO may also maintain the integrity of the vessel wall by directly blocking vascular cell apoptosis and by inhibiting the release of pro-apoptotic inflammatory cytokines from the vessel wall. These effects of CO are mediated via multiple pathways, including activation of soluble guanylate cyclase, potassium channels, p38 mitogen-activated protein kinase, or inhibition of cytochrome P450. In addition, the release of bile pigments may serve to sustain vascular homeostasis by protecting vascular cells from oxidative stress and by inhibiting the adhesion and infiltration of leukocytes into the vessel wall. Induction of HO-1 gene expression and the subsequent release of CO and bile pigments are observed in numerous vascular disorders and may provide an important adaptive mechanism to preserve homeostasis at sites of vascular injury. Thus, the HO-catalyzed formation of CO and bile pigments by vascular cells may function as a critical endogenous vasoprotective system. Moreover, pharmacological or genetic approaches targeting HO-1 to the vessel wall may represent a novel therapeutic approach in treating vascular disease.

  8. 21 CFR 73.3128 - Mica-based pearlescent pigments.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Mica-based pearlescent pigments. 73.3128 Section 73.3128 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL... amounts not to exceed the minimum reasonably required to accomplish the intended coloring effect....

  9. 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 73.3128 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL... amounts not to exceed the minimum reasonably required to accomplish the intended coloring effect....

  10. Idiopathic eruptive macular pigmentation: report on two cases.

    PubMed

    Grover, Sanjiv; Basu, Atoshi

    2010-01-01

    Idiopathic eruptive macular pigmentation (IEMP) is a rather under-reported condition of unknown etiology. Clinically consisting of benign hyperpigmented macules, the condition is characterized histopathologically by dermal melanization. It must be differentiated from lichen planus pigmentosus, erythema dyschromicum perstans, fixed drug eruption and mastocytosis.

  11. IDIOPATHIC ERUPTIVE MACULAR PIGMENTATION: REPORT ON TWO CASES

    PubMed Central

    Grover, Sanjiv; Basu, Atoshi

    2010-01-01

    Idiopathic eruptive macular pigmentation (IEMP) is a rather under-reported condition of unknown etiology. Clinically consisting of benign hyperpigmented macules, the condition is characterized histopathologically by dermal melanization. It must be differentiated from lichen planus pigmentosus, erythema dyschromicum perstans, fixed drug eruption and mastocytosis. PMID:21063525

  12. Social stress effects on pigmentation and monoamines in Arctic charr.

    PubMed

    Backström, Tobias; Heynen, Martina; Brännäs, Eva; Nilsson, Jan; Winberg, Svante; Magnhagen, Carin

    2015-09-15

    Pigmentation often signals status and in general melanin-based pigmentation is indicative of aggression and stress resilience in vertebrates. This is evident in the salmonids Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) where more melanin spotted individuals are more stress resilient. However, in the salmonid Arctic charr (Salvelinus alpinus) it seems as if it is carotenoid-based pigmentation that signals aggression and stress resilience. In our study, social stress effects on carotenoid-based spots, and behavioural and physiological stress responses were investigated. Socially stressed individuals have more spots, and behavioural stress responses were associated with spots. Some of the results concerning physiological stress responses, such as plasma cortisol levels and monoaminergic activity, are associated with spottiness. Further, the earlier proposed lateralization of spots, with left side connected to stress responsiveness and right side to aggression, is to some extent validated although not conclusively. In conclusion, this study provides further evidence that more stressed charr have more carotenoid spots, and for the first time monoaminergic activity is shown to be connected with carotenoid pigmentation.

  13. Gene regulation networks generate diverse pigmentation patterns in plants.

    PubMed

    Albert, Nick W; Davies, Kevin M; Schwinn, Kathy E

    2014-01-01

    The diversity of pigmentation patterns observed in plants occurs due to the spatial distribution and accumulation of colored compounds, which may also be associated with structural changes to the tissue. Anthocyanins are flavonoids that provide red/purple/blue coloration to plants, often forming complex patterns such as spots, stripes, and vein-associated pigmentation, particularly in flowers. These patterns are determined by the activity of MYB-bHLH-WDR (MBW) transcription factor complexes, which activate the anthocyanin biosynthesis genes, resulting in anthocyanin pigment accumulation. Recently, we established that the MBW complex controlling anthocyanin synthesis acts within a gene regulation network that is conserved within at least the Eudicots. This network involves hierarchy, reinforcement, and feedback mechanisms that allow for stringent and responsive regulation of the anthocyanin biosynthesis genes. The gene network and mobile nature of the WDR and R3-MYB proteins provide exciting new opportunities to explore the basis of pigmentation patterning, and to investigate the evolutionary history of the MBW components in land plants.

  14. Apollo 12 lunar material - Effects on plant pigments.

    NASA Technical Reports Server (NTRS)

    Weete, J. D.; Walkinshaw, C. H.

    1972-01-01

    Tissue cultures of tobacco grown for 12 weeks in contact with lunar material returned by Apollo 12 contained 21 to 35% more total pigment than control tissues. This difference is due primarily to increased chlorophyll a concentrations per gram fresh weight of tissue in experimental cultures. No differences were noted in the fresh or dry weight of the experimental and control cultures.

  15. Variability of surface pigment concentrations in the South Atlantic Bight

    NASA Technical Reports Server (NTRS)

    Mcclain, Charles R.; Yoder, James A.; Blanton, J. O.; Atkinson, L. P.; Lee, T. N.

    1988-01-01

    A time sequence of surface pigment images of the South Atlantic Bight (SAB), derived from the Nimbus 7 CZCS for the period between November 1978 and October 1979, was correlated with in situ observations of hydrographic parameters, fresh-water discharge, sea level, coastal winds, and currents in order to couple physical processes and the spatial and temporal variability of the surface pigment fields. A definite seasonal modulation of the surface pigment fields was found, with the concentrations in the Georgia Bight being highest in summer, and those north of Cape Romain highest in winter. This phase difference was found to be the result of variations in wind fields, Gulf Stream-shelf interactions, and fresh-water discharge patterns. At some locations (e.g., near Charleston) the alongshore band of high pigment concentrations increased in width throughout the year; at other locations (near Jacksonville), the alongsore band exhibited a minimum width in the summer and a maximum width in the fall of 1979.

  16. Melanin: the biophysiology of oral melanocytes and physiological oral pigmentation.

    PubMed

    Feller, Liviu; Masilana, Aubrey; Khammissa, Razia A G; Altini, Mario; Jadwat, Yusuf; Lemmer, Johan

    2014-03-24

    The presence of melanocytes in the oral epithelium is a well-established fact, but their physiological functions are not well defined. Melanin provides protection from environmental stressors such as ultraviolet radiation and reactive oxygen species; and melanocytes function as stress-sensors having the capacity both to react to and to produce a variety of microenvironmental cytokines and growth factors, modulating immune, inflammatory and antibacterial responses. Melanocytes also act as neuroendocrine cells producing local neurotransmitters including acetylcholine, catecholamines and opioids, and hormones of the melanocortin system such as proopiomelanocortin, adrenocorticotropic hormone and α-melanocyte stimulating hormone, that participate in intracellular and in intercellular signalling pathways, thus contributing to tissue homeostasis.There is a wide range of normal variation in melanin pigmentation of the oral mucosa. In general, darker skinned persons more frequently have oral melanin pigmentation than light-skinned persons. Variations in oral physiological pigmentation are genetically determined unless associated with some underlying disease.In this article, we discuss some aspects of the biophysiology of oral melanocytes, of the functions of melanin, and of physiological oral pigmentation.

  17. How does agonistic behaviour differ in albino and pigmented fish?

    PubMed Central

    Horký, Pavel; Wackermannová, Marie

    2016-01-01

    In addition to hypopigmentation of the skin and red iris colouration, albino animals also display distinct physiological and behavioural alterations. However, information on the social interactions of albino animals is rare and has mostly been limited to specially bred strains of albino rodents and animals from unique environments in caves. Differentiating between the effects of albinism and domestication on behaviour in rodents can be difficult, and social behaviour in cave fish changes according to species-specific adaptations to conditions of permanent darkness. The agonistic behaviours of albino offspring of pigmented parents have yet to be described. In this study, we observed agonistic behaviour in albino and pigmented juvenile Silurus glanis catfish. We found that the total number of aggressive interactions was lower in albinos than in pigmented catfish. The distance between conspecifics was also analysed, and albinos showed a tendency towards greater separation from their same-coloured conspecifics compared with pigmented catfish. These results demonstrate that albinism can be associated with lower aggressiveness and with reduced shoaling behaviour preference, as demonstrated by a tendency towards greater separation of albinos from conspecifics. PMID:27114883

  18. Controlling composition and color characteristics of Monascus pigments by pH and nitrogen sources in submerged fermentation.

    PubMed

    Shi, Kan; Song, Da; Chen, Gong; Pistolozzi, Marco; Wu, Zhenqiang; Quan, Lei

    2015-08-01

    Submerged fermentations of Monascus anka were performed with different nitrogen sources at different pH in 3 L bioreactors. The results revealed that the Monascus pigments dominated by different color components (yellow pigments, orange pigments or red pigments) could be selectively produced through pH control and nitrogen source selection. A large amount of intracellular pigments dominated by orange pigments and a small amount of water-soluble extracellular yellow pigments were produced at low pH (pH 2.5 and 4.0), independently of the nitrogen source employed. At higher pH (pH 6.5), the role of the nitrogen source became more significant. In particular, when ammonium sulfate was used as nitrogen source, the intracellular pigments were dominated by red pigments with a small amount of yellow pigments. Conversely, when peptone was used, intracellular pigments were dominated by yellow pigments with a few red pigments derivatives. Neither the presence of peptone nor ammonium sulfate promoted the production of intracellular orange pigments while extracellular pigments with an orangish red color were observed in both cases, with a higher yield when peptone was used. Two-stage pH control fermentation was then performed to improve desirable pigments yield and further investigate the effect of pH and nitrogen sources on pigments composition. These results provide a useful strategy to produce Monascus pigments with different composition and different color characteristics.

  19. Rapamycin treatment causes developmental delay, pigmentation defects, and gastrointestinal malformation on Xenopus embryogenesis

    SciTech Connect

    Moriyama, Yuki; Ohata, Yoshihisa; Mori, Shoko; Matsukawa, Shinya; Michiue, Tatsuo; Asashima, Makoto; Kuroda, Hiroki

    2011-01-28

    Research highlights: {yields} Does famous anti-aging drug rapamycin work from the beginning of life? The answer is yes. {yields} This study shows that developmental speed of frog embryo was dose-dependently decreased by rapamycin treatment. {yields} In additions, morphogenetic effects such as less pigmentations and gut malformation are occurred by rapamycin. -- Abstract: Rapamycin is a drug working as an inhibitor of the TOR (target of rapamycin) signaling pathway and influences various life phenomena such as cell growth, proliferation, and life span extension in eukaryote. However, the extent to which rapamycin controls early developmental events of amphibians remains to be understood. Here we report an examination of rapamycin effects during Xenopus early development, followed by a confirmation of suppression of TOR downstream kinase S6K by rapamycin treatment. First, we found that developmental speed was declined in dose-dependent manner of rapamycin. Second, black pigment spots located at dorsal and lateral skin in tadpoles were reduced by rapamycin treatment. Moreover, in tadpole stages severe gastrointestinal malformations were observed in rapamycin-treated embryos. Taken together with these results, we conclude that treatment of the drug rapamycin causes enormous influences on early developmental period.

  20. Structure and Conformation of the Carotenoids in Human Retinal Macular Pigment

    PubMed Central

    Arteni, Ana-Andreea; Fradot, Mathias; Galzerano, Denise; Mendes-Pinto, Maria M.; Sahel, José-Alain; Picaud, Serge; Robert, Bruno; Pascal, Andrew A.

    2015-01-01

    Human retinal macular pigment (MP) is formed by the carotenoids lutein and zeaxanthin (including the isomer meso-zeaxanthin). MP has several functions in improving visual performance and protecting against the damaging effects of light, and MP levels are used as a proxy for macular health–specifically, to predict the likelihood of developing age-related macular degeneration. While the roles of these carotenoids in retinal health have been the object of intense study in recent years, precise mechanistic details of their protective action remain elusive. We have measured the Raman signals originating from MP carotenoids in ex vivo human retinal tissue, in order to assess their structure and conformation. We show that it is possible to distinguish between lutein and zeaxanthin, by their excitation profile (related to their absorption spectra) and the position of their ν1 Raman mode. In addition, analysis of the ν4 Raman band indicates that these carotenoids are present in a specific, constrained conformation in situ, consistent with their binding to specific proteins as postulated in the literature. We discuss how these conclusions relate to the function of these pigments in macular protection. We also address the possibilities for a more accurate, consistent measurement of MP levels by Raman spectroscopy. PMID:26313550