Organ-specific radiation-induced cancer risk estimates due to radiotherapy for benign pigmented villonodular synovitis

NASA Astrophysics Data System (ADS)

Mazonakis, Michalis; Tzedakis, Antonis; Lyraraki, Efrossyni; Damilakis, John

2016-09-01

Pigmented villonodular synovitis (PVNS) is a benign disease affecting synovial membranes of young and middle-aged adults. The aggressive treatment of this disorder often involves external-beam irradiation. This study was motivated by the lack of data relating to the radiation exposure of healthy tissues and radiotherapy-induced cancer risk. Monte Carlo methodology was employed to simulate a patient’s irradiation for PVNS in the knee and hip joints with a 6 MV photon beam. The average radiation dose received by twenty-two out-of-field critical organs of the human body was calculated. These calculations were combined with the appropriate organ-, age- and gender-specific risk coefficients of the BEIR-VII model to estimate the lifetime probability of cancer development. The risk for carcinogenesis to colon, which was partly included in the treatment fields used for hip irradiation, was determined with a non-linear mechanistic model and differential dose-volume histograms obtained by CT-based 3D radiotherapy planning. Risk assessments were compared with the nominal lifetime intrinsic risk (LIR) values. Knee irradiation to 36 Gy resulted in out-of-field organ doses of 0.2-24.6 mGy. The corresponding range from hip radiotherapy was 1.2-455.1 mGy whereas the organ equivalent dose for the colon was up to 654.9 mGy. The organ-specific cancer risks from knee irradiation for PVNS were found to be inconsequential since they were at least 161.5 times lower than the LIRs irrespective of the patient’s age and gender. The bladder and colon cancer risk from radiotherapy in the hip joint was up to 3.2 and 6.6 times smaller than the LIR, respectively. These cancer risks may slightly elevate the nominal incidence rates and they should not be ignored during the patient’s treatment planning and follow-up. The probabilities for developing any other solid tumor were more than 20 times lower than the LIRs and, therefore, they may be considered as small.

Radiofrequency thermo-ablation of PVNS in the knee: initial results.

PubMed

Lalam, Radhesh K; Cribb, Gillian L; Cassar-Pullicino, Victor N; Cool, Wim P; Singh, Jaspreet; Tyrrell, Prudencia N M; Tins, Bernhard J; Winn, Naomi

2015-12-01

Pigmented villonodular synovitis (PVNS) is normally treated by arthroscopic or open surgical excision. We present our initial experience with radiofrequency thermo-ablation (RF ablation) of PVNS located in an inaccessible location in the knee. Review of all patients with histologically proven PVNS treated with RF ablation and with at least 2-year follow-up. Three patients met inclusion criteria and were treated with RF ablation. Two of the patients were treated successfully by one ablation procedure. One of the three patients had a recurrence which was also treated successfully by repeat RF ablation. There were no complications and all patients returned to their previous occupations following RF ablation. In this study we demonstrated the feasibility of performing RF ablation to treat PVNS in relatively inaccessible locations with curative intent. We have also discussed various post-ablation imaging appearances which can confound the assessment for residual/recurrent disease.

CSF-1R Inhibitor Development: Current Clinical Status.

PubMed

Peyraud, Florent; Cousin, Sophie; Italiano, Antoine

2017-09-05

Colony-stimulating factor 1 receptor (CSF-1R) and its ligands, CSF-1 and interleukin 34 (IL-34), regulate the function and survival of tumor-associated macrophages, which are involved in tumorigenesis and in the suppression of antitumor immunity. Moreover, the CSF-1R/CSF-1 axis has been implicated in the pathogenesis of pigmented villonodular synovitis (PVNS), a benign tumor of the synovium. As advanced or metastatic malignant solid tumors and relapsed/refractory PVNS remain unresolved therapeutic problems, new approaches are needed to improve the outcome of patients with these conditions. In solid tumors, targeting CSF-1R via either small molecules or antibodies has shown interesting results in vitro but limited antitumor activity in vivo. Concerning PVNS, clinical trials assessing CSF-1R inhibitors have revealed promising initial outcomes. Blocking CSF-1/CSF-1R signaling represents a promising immunotherapy approach and several new potential combination therapies for future clinical testing.

Multifocal tenosynovial giant cell tumors in a child with Noonan syndrome.

PubMed

Meyers, Arthur B; Awomolo, Agboola O; Szabo, Sara

2017-03-01

Noonan syndrome is a genetic disorder with variable expression of distinctive facial features, webbed neck, chest deformity, short stature, cryptorchidism and congenital heart disease. The association of Noonan syndrome and giant cell granulomas of the mandible is widely reported. However, Noonan syndrome may also be associated with single or multifocal tenosynovial giant cell tumors, also referred to as pigmented villonodular synovitis. We report a child with Noonan syndrome, giant cell granulomas of the mandible and synovial and tenosynovial giant cell tumors involving multiple joints and tendon sheaths who was initially misdiagnosed with juvenile idiopathic arthritis. It is important for radiologists to be aware of the association of Noonan syndrome and multifocal giant cell lesions, which can range from the more commonly described giant cell granulomas of the mandible to isolated or multifocal intra- or extra-articular tenosynovial giant cell tumors or a combination of all of these lesions.

Portable laser-induced breakdown spectroscopy/diffuse reflectance hybrid spectrometer for analysis of inorganic pigments

NASA Astrophysics Data System (ADS)

Siozos, Panagiotis; Philippidis, Aggelos; Anglos, Demetrios

2017-11-01

A novel, portable spectrometer, combining two analytical techniques, laser-induced breakdown spectroscopy (LIBS) and diffuse reflectance spectroscopy, was developed with the aim to provide an enhanced instrumental and methodological approach with regard to the analysis of pigments in objects of cultural heritage. Technical details about the hybrid spectrometer and its operation are presented and examples are given relevant to the analysis of paint materials. Both LIBS and diffuse reflectance spectra in the visible and part of the near infrared, corresponding to several neat mineral pigment samples, were recorded and the complementary information was used to effectively distinguish different types of pigments even if they had similar colour or elemental composition. The spectrometer was also employed in the analysis of different paints on the surface of an ancient pottery sherd demonstrating the capabilities of the proposed hybrid diagnostic approach. Despite its instrumental simplicity and compact size, the spectrometer is capable of supporting analytical campaigns relevant to archaeological, historical or art historical investigations, particularly when quick data acquisition is required in the context of surveys of large numbers of objects and samples.

SOS1 and PTPN11 mutations in five cases of Noonan syndrome with multiple giant cell lesions.

PubMed

Beneteau, Claire; Cavé, Hélène; Moncla, Anne; Dorison, Nathalie; Munnich, Arnold; Verloes, Alain; Leheup, Bruno

2009-10-01

We report five cases of multiple giant cell lesions in patients with typical Noonan syndrome. Such association has frequently been referred to as Noonan-like/multiple giant cell (NL/MGCL) syndrome before the molecular definition of Noonan syndrome. Two patients show mutations in PTPN11 (p.Tyr62Asp and p.Asn308Asp) and three in SOS1 (p.Arg552Ser and p.Arg552Thr). The latter are the first SOS1 mutations reported outside PTPN11 in NL/MGCL syndrome. MGCL lesions were observed in jaws ('cherubism') and joints ('pigmented villonodular synovitis'). We show through those patients that both types of MGCL are not PTPN11-specific, but rather represent a low penetrant (or perhaps overlooked) complication of the dysregulated RAS/MAPK signaling pathway. We recommend discarding NL/MGCL syndrome from the nosology, as this presentation is neither gene-nor allele-specific of Noonan syndrome; these patients should be described as Noonan syndrome with MGCL (of the mandible, the long bone...). The term cherubism should be used only when multiple giant cell lesions occur without any other clinical and molecular evidence of Noonan syndrome, with or without mutations of the SH3BP2 gene.

Impact of long-wavelength UVA and visible light on melanocompetent skin.

PubMed

Mahmoud, Bassel H; Ruvolo, Eduardo; Hexsel, Camile L; Liu, Yang; Owen, Michael R; Kollias, Nikiforos; Lim, Henry W; Hamzavi, Iltefat H

2010-08-01

The purpose of this study was to determine the effect of visible light on the immediate pigmentation and delayed tanning of melanocompetent skin; the results were compared with those induced by long-wavelength UVA (UVA1). Two electromagnetic radiation sources were used to irradiate the lower back of 20 volunteers with skin types IV-VI: UVA1 (340-400 nm) and visible light (400-700 nm). Pigmentation was assessed by visual examination, digital photography with a cross-polarized filter, and diffused reflectance spectroscopy at 7 time points over a 2-week period. Confocal microscopy and skin biopsies for histopathological examination using different stains were carried out. Irradiation was also carried out on skin type II. Results showed that although both UVA1 and visible light can induce pigmentation in skin types IV-VI, pigmentation induced by visible light was darker and more sustained. No pigmentation was observed in skin type II. The quality and quantity of pigment induced by visible light and UVA1 were different. These findings have potential implications on the management of photoaggravated pigmentary disorders, the proper use of sunscreens, and the treatment of depigmented lesions.

Diffuse reflectance of TiO 2 pigmented paints: Spectral dependence of the average pathlength parameter and the forward scattering ratio

NASA Astrophysics Data System (ADS)

Vargas, William E.; Amador, Alvaro; Niklasson, Gunnar A.

2006-05-01

Diffuse reflectance spectra of paint coatings with different pigment concentrations, normally illuminated with unpolarized radiation, have been measured. A four-flux radiative transfer approach is used to model the diffuse reflectance of TiO2 (rutile) pigmented coatings through the solar spectral range. The spectral dependence of the average pathlength parameter and of the forward scattering ratio for diffuse radiation, are explicitly incorporated into this four-flux model from two novel approximations. The size distribution of the pigments has been taken into account to obtain the averages of the four-flux parameters: scattering and absorption cross sections, forward scattering ratios for collimated and isotropic diffuse radiation, and coefficients involved in the expansion of the single particle phase function in terms of Legendre polynomials.

Sporothrix brunneoviolacea and Sporothrix dimorphospora, two new members of the Ophiostoma stenoceras-Sporothrix schenckii complex.

PubMed

Madrid, H; Gené, J; Cano, J; Silvera, C; Guarro, J

2010-01-01

Sporothrix inflata is a saprobic member of the Ophiostoma stenoceras-Sporothrix schenckii species complex, reported mainly from soil. Ophiostoma bragantinum, an ascomycete described from Brazil, has been proposed as its possible teleomorph. Previous studies revealed that Sporothrix inflata is phenotypically and genetically variable, suggesting the existence of cryptic species. During a continued survey on the biodiversity of microfungi from different countries, seven isolates morphologically similar to S. inflata were obtained from soil samples collected in Spain and USA. In this study their phenotypic features and phylogenetic relationships were assessed. DNA sequence data of two nuclear loci revealed that these isolates correspond to two unnamed clades in S. inflata s.l., one of which also included the type strain of Humicola dimorphospora, a species that traditionally has been considered a synonym of S. inflata. These two groups are proposed herein as Sporothrix brunneoviolacea sp. nov. and Sporothrix dimorphospora comb. nov. S. brunneoviolacea is characterized phenotypically by the production of a diffusible violet-brown pigment in culture and mostly globose, pigmented, lateral blastoconidia. On the other hand S. dimorphospora lacks diffusible pigments and shows mostly subglobose to obovoid pigmented lateral blastoconidia. In contrast to the type strain of S. inflata S. brunneoviolacea and S. dimorphospora assimilate raffinose. The phylogenetic analysis suggested that the proposed anamorph-teleomorph connection between S. inflata and O. bragantinum might not be correct.

Identification and cloning of a type III polyketide synthase required for diffusible pigment biosynthesis in Saccharopolyspora erythraea.

PubMed

Cortés, Jesús; Velasco, Javier; Foster, Graham; Blackaby, Andrew P; Rudd, Brian A M; Wilkinson, Barrie

2002-06-01

The soluble, diffusible red-brown pigment produced by a Saccharopolyspora erythraea "red variant" has been shown to contain glycosylated and polymerized derivatives of 2,5,7-trihydroxy-1,4-naphthoquinone (flaviolin). Flaviolin is a spontaneous oxidation product of 1,3,6,8-tetrahydroxynaphthalene (THN), which is biosynthesized in bacteria by a chalcone synthase-like (CS-like) type III polyketide synthase (PKS). A fragment of the gene responsible for THN biosynthesis in S. erythraea E_8-7 was amplified by polymerase chain reaction (PCR) using degenerate primers based on conserved regions of known plant CS and bacterial CS-like genes. From the isolated fragment, a suicide vector was prepared, which was subsequently used to disrupt the red-brown pigment-producing (rpp) locus in S. erythraea, generating a mutant that displayed an albino phenotype. Chromosomal DNA from the albino mutant was subsequently used in a vector-recapture protocol to isolate a plasmid that contained an insert spanning the entire rpp locus. Sequencing of the insert revealed that the disrupted open reading frame (ORF) encodes a CS-like protein displaying 69% sequence identity to the rppA gene of Streptomyces griseus. The S. griseus rppA gene encodes RppA, the first characterized bacterial CS-like protein, which is sufficient in vitro for the synthesis of THN from malonyl-CoA. The rppA disruption mutant and rppA sequence provided a means by which to address the mechanism of diffusible pigment biosynthesis, as well as to investigate any link between this and the modulation of erythromycin A titre, which has been observed for S. erythraea variants.

Are there mechanistic differences between ultraviolet and visible radiation induced skin pigmentation?

PubMed

Ramasubramaniam, Rajagopal; Roy, Arindam; Sharma, Bharati; Nagalakshmi, Surendra

2011-12-01

Most of the studies on sunlight-induced pigmentation of skin are mainly focused on ultraviolet (UV) radiation-induced pigmentation and ways to prevent it. Recent studies have shown that the visible component of sunlight can also cause significant skin pigmentation. In the current study, the extent of pigmentation induced by UV and visible regions of sunlight in subjects with Fitzpatrick skin type IV-V was measured and compared with pigmentation induced by total sunlight. The immediate pigment darkening (IPD) induced by the visible fraction of sunlight is not significantly different from that induced by the UV fraction. However, the persistent pigment darkening (PPD) induced by visible fraction of sunlight in significantly lower than that induced by the UV fraction. The dose responses of IPD induced by UV, visible light and total sunlight suggest that both UV and visible light interact with the same precursor although UV is 25 times more efficient in inducing pigmentation per J cm(-2) of irradiation compared to visible radiation. The measured diffused reflection spectra and decay kinetics of UV and visible radiation-induced pigmentation are very similar, indicating that the nature of the transient and persistent species involved in both the processes are also likely to be same.

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.

Radiotherapy for benign disease; assessing the risk of radiation-induced cancer following exposure to intermediate dose radiation

PubMed Central

Hatfield, Paul; Prestwich, Robin JD; Shaffer, Richard E; Taylor, Roger E

2015-01-01

Most radiotherapy (RT) involves the use of high doses (>50 Gy) to treat malignant disease. However, low to intermediate doses (approximately 3–50 Gy) can provide effective control of a number of benign conditions, ranging from inflammatory/proliferative disorders (e.g. Dupuytren's disease, heterotopic ossification, keloid scarring, pigmented villonodular synovitis) to benign tumours (e.g. glomus tumours or juvenile nasopharyngeal angiofibromas). Current use in UK RT departments is very variable. This review identifies those benign diseases for which RT provides good control of symptoms with, for the most part, minimal side effects. However, exposure to radiation has the potential to cause a radiation-induced cancer (RIC) many years after treatment. The evidence for the magnitude of this risk comes from many disparate sources and is constrained by the small number of long-term studies in relevant clinical cohorts. This review considers the types of evidence available, i.e. theoretical models, phantom studies, epidemiological studies, long-term follow-up of cancer patients and those treated for benign disease, although many of the latter data pertain to treatments that are no longer used. Informative studies are summarized and considered in relation to the potential for development of a RIC in a range of key tissues (skin, brain etc.). Overall, the evidence suggests that the risks of cancer following RT for benign disease for currently advised protocols are small, especially in older patients. However, the balance of risk vs benefit needs to be considered in younger adults and especially if RT is being considered in adolescents or children. PMID:26462717

Talaromyces atroroseus, a New Species Efficiently Producing Industrially Relevant Red Pigments

PubMed Central

Frisvad, Jens C.; Yilmaz, Neriman; Thrane, Ulf; Rasmussen, Kasper Bøwig; Houbraken, Jos; Samson, Robert A.

2013-01-01

Some species of Talaromyces secrete large amounts of red pigments. Literature has linked this character to species such as Talaromyces purpurogenus, T. albobiverticillius, T. marneffei, and T. minioluteus often under earlier Penicillium names. Isolates identified as T. purpurogenus have been reported to be interesting industrially and they can produce extracellular enzymes and red pigments, but they can also produce mycotoxins such as rubratoxin A and B and luteoskyrin. Production of mycotoxins limits the use of isolates of a particular species in biotechnology. Talaromyces atroroseus sp. nov., described in this study, produces the azaphilone biosynthetic families mitorubrins and Monascus pigments without any production of mycotoxins. Within the red pigment producing clade, T. atroroseus resolved in a distinct clade separate from all the other species in multigene phylogenies (ITS, β-tubulin and RPB1), which confirm its unique nature. Talaromyces atroroseus resembles T. purpurogenus and T. albobiverticillius in producing red diffusible pigments, but differs from the latter two species by the production of glauconic acid, purpuride and ZG–1494α and by the dull to dark green, thick walled ellipsoidal conidia produced. The type strain of Talaromyces atroroseus is CBS 133442 PMID:24367630

CSF1R inhibition with emactuzumab in locally advanced diffuse-type tenosynovial giant cell tumours of the soft tissue: a dose-escalation and dose-expansion phase 1 study.

PubMed

Cassier, Philippe A; Italiano, Antoine; Gomez-Roca, Carlos A; Le Tourneau, Christophe; Toulmonde, Maud; Cannarile, Michael A; Ries, Carola; Brillouet, Anne; Müller, Claudia; Jegg, Anna-Maria; Bröske, Ann-Marie; Dembowski, Markus; Bray-French, Katharine; Freilinger, Christine; Meneses-Lorente, Georgina; Baehner, Monika; Harding, Ross; Ratnayake, Jayantha; Abiraj, Keelara; Gass, Nathalie; Noh, Karen; Christen, Randolph D; Ukarma, Lidia; Bompas, Emmanuelle; Delord, Jean-Pierre; Blay, Jean-Yves; Rüttinger, Dominik

2015-08-01

Diffuse-type tenosynovial giant cell tumour (dt-GCT) of the soft tissue (alternatively known as pigmented villonodular synovitis), an orphan disease with unmet medical need, is characterised by an overexpression of colony-stimulating factor 1 (CSF1), and is usually caused by a chromosomal translocation involving CSF1. CSF1 receptor (CSF1R) activation leads to the recruitment of CSF1R-expressing cells of the mononuclear phagocyte lineage that constitute the tumor mass in dt-GCT. Emactuzumab (RG7155) is a novel monoclonal antibody that inhibits CSF1R activation. We have assessed the safety, tolerability and activity of emactuzumab in patients with Dt-GCT of the soft tissue. In this phase 1, first-in-human dose-escalation and dose-expansion study, eligible patients were aged 18 years or older with dt-GCT of the soft tissue with locally advanced disease or resectable tumours requiring extensive surgery, an Eastern Cooperative Oncology Group performance status of 1 or less, measurable disease according to Response Evaluation Criteria In Solid Tumors version 1.1, and adequate end-organ function. Patients with GCT of the bone were not eligible. Patients received intravenous emactuzumab at 900 mg, 1350 mg, or 2000 mg every 2 weeks in the dose-escalation phase and at the optimal biological dose in a dose-expansion phase. The primary objective was to evaluate the safety and tolerability of emactuzumab, and to determine the maximum tolerated dose or optimal biological dose. All treated patients were included in the analyses. Expansion cohorts are currently ongoing. This study is registered with ClinicalTrials.gov, number NCT01494688. Between July 26, 2012, and Oct 21, 2013, 12 patients were enrolled in the dose-escalation phase. No dose-limiting toxicities were noted in the dose-escalation cohort; on the basis of pharmacokinetic, pharmacodynamic, and safety information, we chose a dose of 1000 mg every 2 week for the dose-expansion cohort, into which 17 patients were enrolled. Owing to different cutoff dates for safety and efficacy readouts, the safety population comprised 25 patients. Common adverse events after emactuzumab treatment were facial oedema (16 [64%] of 25 patients), asthenia (14 [56%]), and pruritus (14 [56%]). Five serious adverse events (periorbital oedema, lupus erythematosus [occurring twice], erythema, and dermohypodermitis all experienced by one [4%] patient each) were reported in five patients. Three of the five serious adverse events-periorbital oedema (one [4%]), lupus erythematosus (one [4%]), and dermohypodermitis (one [4%])-were assessed as grade 3. Two other grade 3 events were reported: mucositis (one [4%]) and fatigue (one [4%]). 24 (86%) of 28 patients achieved an objective response; two (7%) patients achieved a complete response. Further study of dt-GCT is warranted and different possibilities, such as an international collaboration with cooperative groups to assure appropriate recruitment in this rare disease, are currently being assessed. F Hoffmann-La Roche. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reconstructing in-vivo reflectance spectrum of pigmented skin lesion by Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Wang, Shuang; He, Qingli; Zhao, Jianhua; Lui, Harvey; Zeng, Haishan

2012-03-01

In dermatology applications, diffuse reflectance spectroscopy has been extensively investigated as a promising tool for the noninvasive method to distinguish melanoma from benign pigmented skin lesion (nevus), which is concentrated with the skin chromophores like melanin and hemoglobin. We carried out a theoretical study to examine melanin distribution in human skin tissue and establish a practical optical model for further pigmented skin investigation. The theoretical simulation was using junctional nevus as an example. A multiple layer skin optical model was developed on established anatomy structures of skin, the published optical parameters of different skin layers, blood and melanin. Monte Carlo simulation was used to model the interaction between excitation light and skin tissue and rebuild the diffuse reflectance process from skin tissue. A testified methodology was adopted to determine melanin contents in human skin based on in vivo diffuse reflectance spectra. The rebuild diffuse reflectance spectra were investigated by adding melanin into different layers of the theoretical model. One of in vivo reflectance spectra from Junctional nevi and their surrounding normal skin was studied by compare the ratio between nevus and normal skin tissue in both the experimental and simulated diffuse reflectance spectra. The simulation result showed a good agreement with our clinical measurements, which indicated that our research method, including the spectral ratio method, skin optical model and modifying the melanin content in the model, could be applied in further theoretical simulation of pigmented skin lesions.

Ozone Sensitivity and Catalase Activity in Pigmented and Non-Pigmented Strains of Serratia Marcescens

PubMed Central

de Ondarza, José

2017-01-01

Background: Ozone exposure rapidly leads to bacterial death, making ozone an effective disinfectant in food industry and health care arena. However, microbial defenses may moderate this effect and play a role in the effective use of oxidizing agents for disinfection. Serratia marcescens is an opportunistic pathogen, expressing genes differentially during infection of a human host. A better understanding of regulatory systems that control expression of Serratia’s virulence genes and defenses is therefore valuable. Objective: Here, we investigated the role of pigmentation and catalase in Serratia marcescens on survival to ozone exposure. Method: Pigmented and non-pigmented strains of Serratia marcescens were cultured to exponential or stationary phase and exposed to 5 ppm of gaseous ozone for 2.5 – 10 minutes. Survival was calculated via plate counts. Catalase activity was measured photometrically and tolerance to hydrogen peroxide was assayed by disk-diffusion. Results: Exposure of S. marcescens to 5 ppm gaseous ozone kills > 90% of cells within 10 minutes in a time and concentration-dependent manner. Although pigmented Serratia (grown at 28°C) survived ozonation better than unpigmented Serratia (grown at 35°C), non-pigmented mutant strains of Serratia had similar ozone survival rates, catalase activity and H2O2 tolerance as wild type strains. Rather, ozone survival and catalase activity were elevated in 6 hour cultures compared to 48 hour cultures. Conclusion: Our studies did not bear out a role for prodigiosin in ozone survival. Rather, induction of oxidative stress responses during exponential growth increased both catalase activity and ozone survival in both pigmented and unpigmented S. marcescens. PMID:28567147

Mechanisms and behavioural functions of structural coloration in cephalopods

PubMed Central

Mäthger, Lydia M.; Denton, Eric J.; Marshall, N. Justin; Hanlon, Roger T.

2008-01-01

Octopus, squid and cuttlefish are renowned for rapid adaptive coloration that is used for a wide range of communication and camouflage. Structural coloration plays a key role in augmenting the skin patterning that is produced largely by neurally controlled pigmented chromatophore organs. While most iridescence and white scattering is produced by passive reflectance or diffusion, some iridophores in squid are actively controlled via a unique cholinergic, non-synaptic neural system. We review the recent anatomical and experimental evidence regarding the mechanisms of reflection and diffusion of light by the different cell types (iridophores and leucophores) of various cephalopod species. The structures that are responsible for the optical effects of some iridophores and leucophores have recently been shown to be proteins. Optical interactions with the overlying pigmented chromatophores are complex, and the recent measurements are presented and synthesized. Polarized light reflected from iridophores can be passed through the chromatophores, thus enabling the use of a discrete communication channel, because cephalopods are especially sensitive to polarized light. We illustrate how structural coloration contributes to the overall appearance of the cephalopods during intra- and interspecific behavioural interactions including camouflage. PMID:19091688

Variation of Synechococcus Pigment Genetic Diversity Along Two Turbidity Gradients in the China Seas.

PubMed

Xia, Xiaomin; Liu, Hongbin; Choi, Donghan; Noh, Jae Hoon

2018-01-01

Synechococcus are important and widely distributed picocyanobacteria that encompass a high pigment diversity. In this study, we developed a primer set (peBF/peAR) for amplifying the cpeBA operon sequence from Synechococcus genomic DNA to study Synechococcus pigment diversity along two turbidity gradients in the China seas. Our data revealed that all previously reported pigment types occurred in the South (SCS) and East (ECS) China Seas. In addition, a novel pigment genetic type (type 3f), represented by the high phycourobilin Synechococcus sp. strain KORDI-100 (Exc495:545 = 2.35), was detected. This pigment genetic type differs from the 3c/3d types not only for a very high PUB/PEB ratio but also for a different intergenic spacer sequence and gene organization of the phycobilisome. Synechococcus of different pigment types exhibited clear niche differentiation. Type 2 dominated in the coastal waters, whereas type 3c/3d and 3f were predominant in oceanic waters of the SCS in summer. In the ECS, however, type 3a was the major pigment type throughout the transect. We suggest that in marine environment, various pigment types often co-occur but with one type dominant and PUB/PEB ratio is related to geographic distribution of Synechococcus pigment types. The two marginal seas of China have markedly different Synechococcus pigment compositions.

Cutaneous manifestations of non-Hodgkin's lymphoma.

PubMed

Kumar, S S; Kuruvilla, M; Pai, G S; Dinesh, M

2003-01-01

Thirty-two confirmed cases of non -Hodgkin's lymphoma (NHL) were examined for cutaneous manifestations for a period of 2 years from November 1998 in KMC Hospital Attavar, Mangalore. Cutaneous manifestations in the study group were compared to a control group of 32 patients. Specific infiltrates were present in all (5/5) CTCL patients and one out of twenty-seven patients with low grade NHL. Morphologically they presented as papules, plaques, nodules and erythroderma. Infective conditions seen in the study group were superficial fungal (7/32) and viral infections (2/ 32). Non-infective conditions were acquired ichthyosis (10/32), generalised pruritus (5/32), insect bite reaction (1/32) and drug eruption (1/32). When compared to control patients only acquired ichthyosis and generalised pruritus were found to be statistically significant. The study group also showed changes due to chemotherapy like diffuse alopecia (24/29), bluish pigmentation of proximal part of nail (4/29), localised pigmentation of palms and soles (1 /29), diffuse pigmentation at injection site (1 /29), pigmentation at scar site (1 /29) and stomatitis (4/29).

Extensile posterior approach to the ankle with detachment of the achilles tendon for oncologic indications.

PubMed

Maheshwari, Aditya V; Walters, Jason A; Henshaw, Robert M

2012-05-01

We describe an extensile posterior approach to the ankle with detachment of the Achilles tendon for resection of extensive tumors involving the posterior ankle. To the best of our knowledge, this approach and its results have not been reported for oncologic indications. The surgical technique involved detachment of the Achilles tendon, tumor resection and reconstruction of the Achilles tendon with anchor sutures, and was used in six patients. The diagnosis was pigmented villonodular synovitis (5) and chondroblastoma (1). At a mean of 6 (range, 2 to 10) years followup, all patients were free from tumor. All patients could walk an unlimited amount without any support. There were no problems with Achilles incompetence. The mean Musculoskeletal Tumor Society score was 97 ± 4.2% (range, 90 to 100) and the mean Achilles Tendon Total Rupture Score was 95 ± 5.7 (range, 87 to 100). One patient with screwed suture anchors had backing out of two anchors along with deep infection, requiring surgical debridement and anchor removal. One other patient had a post-traumatic small wound dehiscence which responded to local wound care. Excellent exposure, tumor control and patient function were achieved by this approach in a select group of patients. The surgical technique described in this report offers another alternative for an extensile posterior approach to the ankle and/or subtalar joints.

Optical clearing of melanoma in vivo: characterization by diffuse reflectance spectroscopy and optical coherence tomography

NASA Astrophysics Data System (ADS)

Pires, Layla; Demidov, Valentin; Vitkin, I. Alex; Bagnato, Vanderlei; Kurachi, Cristina; Wilson, Brian C.

2016-08-01

Melanoma is the most aggressive type of skin cancer, with significant risk of fatality. Due to its pigmentation, light-based imaging and treatment techniques are limited to near the tumor surface, which is inadequate, for example, to evaluate the microvascular density that is associated with prognosis. White-light diffuse reflectance spectroscopy (DRS) and near-infrared optical coherence tomography (OCT) were used to evaluate the effect of a topically applied optical clearing agent (OCA) in melanoma in vivo and to image the microvascular network. DRS was performed using a contact fiber optic probe in the range from 450 to 650 nm. OCT imaging was performed using a swept-source system at 1310 nm. The OCT image data were processed using speckle variance and depth-encoded algorithms. Diffuse reflectance signals decreased with clearing, dropping by ˜90% after 45 min. OCT was able to image the microvasculature in the pigmented melanoma tissue with good spatial resolution up to a depth of ˜300 μm without the use of OCA; improved contrast resolution was achieved with optical clearing to a depth of ˜750 μm in tumor. These findings are relevant to potential clinical applications in melanoma, such as assessing prognosis and treatment responses. Optical clearing may also facilitate the use of light-based treatments such as photodynamic therapy.

Relationship of Basal laminar deposit and membranous debris to the clinical presentation of early age-related macular degeneration.

PubMed

Sarks, Shirley; Cherepanoff, Svetlana; Killingsworth, Murray; Sarks, John

2007-03-01

To correlate basal laminar deposit (BLamD) and membranous debris, including basal linear deposit (BLinD), with the evolution of early age-related macular degeneration (AMD). A clinicopathologic collection of 132 eyes with a continuous layer of BLamD was reviewed. The thickness and type of BLamD and the sites of membranous debris deposition were correlated with the clinical progression of the disease. Two types of BLamD, termed early and late, were identified based on light microscopic appearance by using the picro-Mallory stain. The progressive accumulation of late type BLamD correlated well with increasing BLamD thickness, advancing RPE degeneration, poorer vision, increasing age, and clinically evident pigment changes. Membranous debris initially accumulated diffusely as BLinD, most eyes with BLinD and early BLamD remaining funduscopically normal. However, membranous debris also formed focal collections as basal mounds internal to the RPE basement membrane and as soft drusen external to the basement membrane. Eyes in which membranous debris remained confined to basal mounds belonged to older patients with poorer vision, whereas patients with soft drusen were younger and had better vision. The presence of BLinD and early BLamD define threshold AMD, which manifests clinically as a normal fundus. Although late BLamD correlates most closely with clinical pigment abnormalities, it is the quantity and sites of membranous debris accumulation that appear to determine whether the disease develops pigment changes only or follows the alternative pathway of soft drusen formation with its attendant greater risk of choroidal neovascularization (CNV).

Reduction of pollutants in painting operation and suggestion of an optimal technique for extracting titanium dioxide from paint sludge in car manufacturing industries--case study (SAIPA).

PubMed

Khezri, Seyed Mostafa; Shariat, Seyed Mahmood; Tabibian, Sahar

2012-06-01

Paint sludge of car manufacturing industries are not disposed in landfills, since they contain hazardous materials with a high concentration of chromium, aluminum, titanium, barium, copper, Iron, magnesium, strontium, and so on. Thus, it is essential to find solutions in order to neutralize them or suggest cost-effective techniques, which are also environmentally acceptable. Because, this sludge contains considerable amounts of Ti pigments and unbaked resins, recycling these pigments--which could be used in a variety of industries such as paint factories--is an appropriate subject for further research. In this article, with the aim of identification of main pollutants in order to eliminate them and suggest a cost-effective solution to recover the sludge, a large number of tests including X-ray fluorescence spectroscopy, X ray diffraction spectroscopy, and diffusion thermal analysis are conducted to determine types and concentration of elements, and combinations of paint sludge in car manufacturing industries. As titanium dioxide (TiO₂) is widely used as the main pigment of automobile paints, an optimal technique is suggested for extracting TiO₂ with high purity percentage through adopting scientific methods such as membrane and electrolysis.

Hepatocellular carcinoma arising in a pigmented telangiectatic adenoma with nuclear β-catenin and glutamine synthetase positivity: case report and review of the literature.

PubMed

Hechtman, Jaclyn F; Raoufi, Mohammad; Fiel, M Isabel; Taouli, Bachir; Facciuto, Marcelo; Schiano, Thomas D; Blouin, Amanda G; Thung, Swan N

2011-06-01

Telangiectatic hepatocellular adenoma is a rare, recently recognized subtype of hepatocellular adenoma that is often underrecognized by pathologists. We report a case of hepatocellular carcinoma arising within a pigmented telangiectatic hepatocellular adenoma in a noncirrhotic man with diffuse glutamine synthetase and nuclear β-catenin positivity. This case highlights malignant transformation of telangiectatic adenomas, and describes a previously unreported association between pigment deposition and telangiectatic adenoma. Radiology, gross pathology, and histopathology are shown. Review of the literature with attention to β-catenin and glutamine synthetase staining, malignant transformation, patient characteristics, the presence of Dubin-Johnson-like pigment, and genetic characteristics of telangiectatic adenomas are discussed.

Disruption of emmetropization and high susceptibility to deprivation myopia in albino guinea pigs.

PubMed

Jiang, Liqin; Long, Keli; Schaeffel, Frank; Zhang, Sen; Zhou, Xiangtian; Lu, Fan; Qu, Jia

2011-08-03

To compare emmetropization in albino and pigmented guinea pigs. Distributions of refractive state were examined in 214 albino and 234 pigmented guinea pigs. Albino (A) and pigmented (P) guinea pigs were divided into two groups, hyperopic (H) and myopic (M). Eye development was separately followed in 10 randomly selected animals from each group (AH, AM, PH, PM) from 2 to 10 weeks of age. In addition, deprivation myopia was induced in 36 age-matched albino (18 AH and 18 AM) and 36 pigmented (18 PH and 18 PM) guinea pigs by diffusers that were worn from 2 to 6 weeks of age. Finally, sclera fibril diameters were measured using transmission electron microscopy. Strikingly, the distributions of refractive errors were bimodal at 2 weeks of age, both in albino and pigmented animals, with clearly different averages (-2.86 ± 5.60 diopters [D] vs. 2.13 ± 5.27 D respectively; t = 9.712; P < 0.001). Spontaneous myopia was more common in albino animals: 70.1% were myopic (AM) and 29.9% hyperopic (AH), whereas only 28.6% were myopic (PM) and 71.4% hyperopic (PH) in pigmented guinea pigs. Different from PM and AM did not show any recovery from myopia. With diffusers, AH became more myopic (-7.61 ± 2.71 D and -11.17 ± 2.55 D) than PH (-4.48 ± 1.46 D and -8.28 ± 2.13 D) after 2 and 4 weeks, respectively. Deprivation myopia could still be induced in PM (-1.64 ± 1.44 D and -5.17 ± 1.88 D after 2 and 4 weeks, respectively; P < 0.01) but not in AM. Scleral fibril diameters were smaller in myopic animals, both albino and pigmented. Deprivation myopia could not be induced in spontaneously myopic but only in hyperopic albino guinea pigs, where it was even higher than in pigmented animals. The distinct effects of albinism on emmetropization will help to elucidate the mechanisms underlying the emmetropization.

Genetic and Virulent Difference Between Pigmented and Non-pigmented Staphylococcus aureus.

PubMed

Zhang, Jing; Suo, Yujuan; Zhang, Daofeng; Jin, Fangning; Zhao, Hang; Shi, Chunlei

2018-01-01

Staphyloxanthin (STX), a golden carotenoid pigment produced by Staphylococcus aureus , is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented S. aureus isolates. However, it is not clear whether natural non-pigmented S. aureus isolates have less virulence than pigmented ones. In this study, it is aimed to compare the pigmented and non-pigmented S. aureus isolates to clarify the genetic and virulent differences between the two groups. Here, 132 S. aureus isolates were divided into two phenotype groups depending on the absorbance (OD 450 ) of the extracted carotenoids. Then, all isolates were subjected to spa typing and multilocus sequence typing (MLST), and then the detection of presence of 30 virulence factors and the gene integrity of crtN and crtM . Furthermore, 24 typical S. aureus isolates and 4 S. argenteus strains were selected for the murine infection assay of in vivo virulence, in which the histological observation and enumeration of CFUs were carried out. These isolates were distributed in 26 sequence types (STs) and 49 spa types. The pigmented isolates were scattered in 25 STs, while the non-pigmented isolates were more centralized, which mainly belonged to ST20 (59%) and ST25 (13%). Among the 54 non-pigmented isolates, about 20% carried intact crtN and crtM genes. The in vivo assay suggested that comparing with pigmented S. aureus , non-pigmented S. aureus and S. argenteus strains did not show a reduced virulence in murine sepsis models. Therefore, it suggested that there were no significant genetic and virulent differences between pigmented and non-pigmented S. aureus .

Modeling of Light Reflection from Human Skin

NASA Astrophysics Data System (ADS)

Delgado, J. A.; Cornejo, A.; Rivas-Silva, J. F.; Rodríguez, E. E.

2006-09-01

In this work a two-layer model is used to simulate the spectral reflectance of adult human skin. We report and discuss diffuse reflectance spectra of this model for three values of the volume fraction of melanosomes fme, namely a) lightly pigmented skin fme = 4%, b) moderately pigmented skin fme = 14% and c) heavily pigmented skin fme = 30% at a volume fraction of blood fbl = 0.2%. We also considered the modeling of reflectance spectra for two values of fbl (0.2% and 1%) with fme = 4%. Both simulations were done in the 400-700 nm spectral range using the Monte Carlo simulation code MCML in standard C. Results showed that the principal signatures of human skin reflectance spectrum are obtained with this model and that it could be of valuable use to made predictions of diffuse reflectance of human skin for different values of the parameters related to skin characterization. These parameters can be associated to distinct medical conditions, such as erythema, jaundice, etc.

Electrophoretic deposited TiO 2 pigment-based back reflectors for thin film solar cells

DOE PAGES

Bills, Braden; Morris, Nathan; Dubey, Mukul; ...

2015-01-16

Highly reflective coatings with strong light scattering effect have many applications in optical components and optoelectronic devices. This paper reports titanium dioxide (TiO 2) pigment-based reflectors that have 2.5 times higher broadband diffuse reflection than commercially produced aluminum or silver based reflectors and result in efficiency enhancements of a single-junction amorphous Si solar cell. Electrophoretic deposition is used to produce pigment-based back reflectors with high pigment density, controllable film thickness and site-specific deposition. Electrical conductivity of the pigment-based back reflectors is improved by creating electrical vias throughout the pigment-based back reflector by making holes using an electrical discharge / dielectricmore » breakdown approach followed by a second electrophoretic deposition of conductive nanoparticles into the holes. While previous studies have demonstrated the use of pigment-based back reflectors, for example white paint, on glass superstrate configured thin film Si solar cells, this work presents a scheme for producing pigment-based reflectors on complex shape and flexible substrates. Finally, mechanical durability and scalability are demonstrated on a continuous electrophoretic deposition roll-to-roll system which has flexible metal substrate capability of 4 inch wide and 300 feet long.« less

Complete resolution of minocycline pigmentation following a single treatment with non-ablative 1550-nm fractional resurfacing in combination with the 755-nm Q-switched alexandrite laser.

PubMed

Vangipuram, Ramya K; DeLozier, Whitney L; Geddes, Elizabeth; Friedman, Paul M

2016-03-01

Pigmentation secondary to minocycline ingestion is an uncommon adverse event affecting 3.7-14.8% of treated individuals for which few effective therapies are available. Three patterns of minocycline pigmentation have a characteristic clinical and histological appearance. The pigment composition in each variety is different and occurs at varying skin depths. Accordingly, a tailored approach according to the type of minocycline pigmentation is crucial for treatment success. The purpose of this intervention was to evaluate the efficacy of non-ablative fractional photothermolysis in combination with the Q-switched alexandrite laser for the treatment of type I minocycline pigmentation on the face. A patient with type I minocycline pigmentation was treated with non-ablative 1550-nm fractional photothermolysis followed immediately by 755-nm Q-switched alexandrite laser and then observed clinically to determine the outcome of this modality. The patient was seen in clinic 1 month later following her single treatment session and 100% clearance of all blue facial pigment was observed. Non-ablative fractional photothermolysis in combination with the 755-nm Q-switched alexandrite laser should be considered for treatment of type I minocycline pigmentation. © 2015 Wiley Periodicals, Inc.

First report of Mycobacterium canariasense catheter-related bacteremia in the Americas.

PubMed

Paniz-Mondolfi, Alberto; Ladutko, Lynn; Brown-Elliott, Barbara A; Vasireddy, Ravikiran; Vasireddy, Sruthi; Wallace, Richard J; Jakubiec, Wesley; Brecher, Stephen; Campbell, Sheldon

2014-06-01

Mycobacterium canariasense is a recently described late-pigmenting, rapidly growing mycobacterium linked to bacteremia in patients with underlying malignant diseases. We report a case of M. canariasense infection in a patient from Massachusetts with underlying diffuse B cell lymphoma, which was identified both by multilocus sequence typing and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). To our knowledge, this is the first description after its original identification in Spain and the first report of this opportunistic pathogen in the Americas. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Classical lepidopteran wing scale colouration in the giant butterfly-moth Paysandisia archon.

PubMed

Stavenga, Doekele G; Leertouwer, Hein L; Meglič, Andrej; Drašlar, Kazimir; Wehling, Martin F; Pirih, Primož; Belušič, Gregor

2018-01-01

The palm borer moth Paysandisia archon (Castniidae; giant butterfly-moths) has brown dorsal forewings and strikingly orange-coloured dorsal hindwings with white spots surrounded by black margins. Here, we have studied the structure and pigments of the wing scales in the various coloured wing areas, applying light and electron microscopy and (micro)spectrophotometry, and we analysed the spatial reflection properties with imaging scatterometry. The scales in the white spots are unpigmented, those in the black and brown wing areas contain various amounts of melanin, and the orange wing scales contain a blue-absorbing ommochrome pigment. In all scale types, the upper lamina acts as a diffuser and the lower lamina as a thin film interference reflector, with thickness of about 200 nm. Scale stacking plays an important role in creating the strong visual signals: the colour of the white eyespots is created by stacks of unpigmented blue scales, while the orange wing colour is strongly intensified by stacking the orange scales.

Tracking the blue: a MLST approach to characterise the Pseudomonas fluorescens group.

PubMed

Andreani, N A; Martino, M E; Fasolato, L; Carraro, L; Montemurro, F; Mioni, R; Bordin, P; Cardazzo, B

2014-05-01

The Pseudomonas fluorescens group comprises several closely related species that are involved in food contamination and spoilage. Specifically, the interest in P. fluorescens as a spoiler of dairy products increased after the cases of "blue mozzarella" that occurred in Italy in 2010. A Multilocus Sequence Typing (MLST) scheme was developed and applied to characterise 136 isolates (reference strains and food borne isolates) at strain level, to reveal the genetic relationships among them and to disclose any possible genetic clustering of phenotypic markers involved in food spoilage (protease, lipase, lecithinase activities and pigmented or fluorescent molecule production). The production of dark blue diffusible pigment was evaluated on several bacterial culture media and directly on mozzarella cheese. The MLST scheme provided precise genotyping at the strain level, and the population analyses of the concatenated sequences allowed major taxa to be defined. This approach was revealed to be suitable for tracking the strains according to their origin, such as dairy plants or food matrices. The genetic analysis revealed the presence of a connection between the blue pigment production and a specific phylogenetic cluster. The development of the online database specific to the P. fluorescens group (http://pubmlst.org/pfluorescens) will facilitate the application of the scheme and the sharing of the data. Copyright © 2013 Elsevier Ltd. All rights reserved.

Reprint of 'Tracking the blue: a MLST approach to characterise the Pseudomonas fluorescens group'.

PubMed

Andreani, N A; Martino, M E; Fasolato, L; Carraro, L; Montemurro, F; Mioni, R; Bordin, P; Cardazzo, B

2015-02-01

The Pseudomonas fluorescens group comprises several closely related species that are involved in food contamination and spoilage. Specifically, the interest in P. fluorescens as a spoiler of dairy products increased after the cases of "blue mozzarella" that occurred in Italy in 2010. A Multilocus Sequence Typing (MLST) scheme was developed and applied to characterise 136 isolates (reference strains and food borne isolates) at strain level, to reveal the genetic relationships among them and to disclose any possible genetic clustering of phenotypic markers involved in food spoilage (protease, lipase, lecithinase activities and pigmented or fluorescent molecule production). The production of dark blue diffusible pigment was evaluated on several bacterial culture media and directly on mozzarella cheese. The MLST scheme provided precise genotyping at the strain level, and the population analyses of the concatenated sequences allowed major taxa to be defined. This approach was revealed to be suitable for tracking the strains according to their origin, such as dairy plants or food matrices. The genetic analysis revealed the presence of a connection between the blue pigment production and a specific phylogenetic cluster. The development of the online database specific to the P. fluorescens group (http://pubmlst.org/pfluorescens) will facilitate the application of the scheme and the sharing of the data. Copyright © 2014. Published by Elsevier Ltd.

Multispectral detection of cutaneous lesions using spectroscopy and microscopy approaches

NASA Astrophysics Data System (ADS)

Borisova, E.; Genova-Hristova, Ts.; Troyanova, P.; Pavlova, E.; Terziev, I.; Semyachkina-Glushkovskaya, O.; Lomova, M.; Genina, E.; Stanciu, G.; Tranca, D.; Avramov, L.

2018-02-01

Autofluorescence, diffuse-reflectance and transmission spectral, and microscopic measurements were made on different cutaneous neoplastic lesions, namely basal cell carcinoma, squamous cell carcinoma, malignant melanoma, and dysplastic and benign lesions related. Spectroscopic measurements were made on ex vivo tissue samples, and confocal microscopy investigations were made on thin tissue slices. Fluorescence spectra obtained reveal statistically significant differences between the different benign, dysplastic and malignant lesions by the level of emission intensity, as well by spectral shape, which are fingerprints applicable for differentiation algorithms. In reflectance mode the most significant differences are related to the influence of skin pigments - melanin and hemoglobin. Transmission spectroscopy mode gave complementary optical properties information about the tissue samples investigated to that one of reflectance and absorption spectroscopy. Using autofluorescence detection of skin lesions we obtain very good diagnostic performance for distinguishing of nonmelanoma lesions. Using diffuse reflectance and transmission spectroscopy we obtain significant tool for pigmented pathologies differentiation, but it is a tool with moderate sensitivity for non-melanoma lesions detection. One could rapidly increase the diagnostic accuracy of the received combined "optical biopsy" method when several spectral detection techniques are applied in common algorithm for lesions' differentiation. Specific spectral features observed in each type of lesion investigated on micro and macro level would be presented and discussed. Correlation between the spectral data received and the microscopic features observed would be discussed in the report.

Unusual development of light-reflecting pigment cells in intact and regenerating tail in the periodic albino mutant of Xenopus laevis.

PubMed

Fukuzawa, Toshihiko

2010-10-01

Unusual light-reflecting pigment cells, "white pigment cells", specifically appear in the periodic albino mutant (a(p) /a(p)) of Xenopus laevis and localize in the same place where melanophores normally differentiate in the wild-type. The mechanism responsible for the development of unusual pigment cells is unclear. In this study, white pigment cells in the periodic albino were compared with melanophores in the wild-type, using a cell culture system and a tail-regenerating system. Observations of both intact and cultured cells demonstrate that white pigment cells are unique in (1) showing characteristics of melanophore precursors at various stages of development, (2) accumulating reflecting platelets characteristic of iridophores, and (3) exhibiting pigment dispersion in response to α-melanocyte stimulating hormone (α-MSH) in the same way that melanophores do. When a tadpole tail is amputated, a functionally competent new tail is regenerated. White pigment cells appear in the mutant regenerating tail, whereas melanophores differentiate in the wild-type regenerating tail. White pigment cells in the mutant regenerating tail are essentially similar to melanophores in the wild-type regenerating tail with respect to their localization, number, and response to α-MSH. In addition to white pigment cells, iridophores which are never present in the intact tadpole tail appear specifically in the somites near the amputation level in the mutant regenerating tail. Iridophores are distinct from white pigment cells in size, shape, blue light-induced fluorescence, and response to α-MSH. These findings strongly suggest that white pigment cells in the mutant arise from melanophore precursors and accumulate reflecting platelets characteristic of iridophores.

Unusual development of light-reflecting pigment cells in intact and regenerating tail in the periodic albino mutant of Xenopus laevis

PubMed Central

2010-01-01

Unusual light-reflecting pigment cells, “white pigment cells”, specifically appear in the periodic albino mutant (ap/ap) of Xenopus laevis and localize in the same place where melanophores normally differentiate in the wild-type. The mechanism responsible for the development of unusual pigment cells is unclear. In this study, white pigment cells in the periodic albino were compared with melanophores in the wild-type, using a cell culture system and a tail-regenerating system. Observations of both intact and cultured cells demonstrate that white pigment cells are unique in (1) showing characteristics of melanophore precursors at various stages of development, (2) accumulating reflecting platelets characteristic of iridophores, and (3) exhibiting pigment dispersion in response to α-melanocyte stimulating hormone (α-MSH) in the same way that melanophores do. When a tadpole tail is amputated, a functionally competent new tail is regenerated. White pigment cells appear in the mutant regenerating tail, whereas melanophores differentiate in the wild-type regenerating tail. White pigment cells in the mutant regenerating tail are essentially similar to melanophores in the wild-type regenerating tail with respect to their localization, number, and response to α-MSH. In addition to white pigment cells, iridophores which are never present in the intact tadpole tail appear specifically in the somites near the amputation level in the mutant regenerating tail. Iridophores are distinct from white pigment cells in size, shape, blue light-induced fluorescence, and response to α-MSH. These findings strongly suggest that white pigment cells in the mutant arise from melanophore precursors and accumulate reflecting platelets characteristic of iridophores. PMID:20859642

Pigmentation after single and multiple UV-exposures depending on UV-spectrum.

PubMed

Ravnbak, M H; Wulf, H C

2007-04-01

Minimal pigmentation dose (MMD) after a single UV-exposure is well investigated. Whereas only few studies have established MMD after multiple UV-exposures and mainly in fair-skinned persons. The purpose of this study was to establish MMD 1 week after, respectively, one and five UV-exposures in volunteers with a large variation in constitutive pigmentation. A total of 52 volunteers (skin Types II-V) had skin pigmentation quantified by reflectance spectroscopy. They were UV-exposed on the back for 1 and 5 days using a Solar Simulator, narrowband UVB, broadband UVA and UVA1. For all sources a higher dose was needed the more pigmented the skin, except for UVA1. After one UV-exposure, we found a significant positive linear correlation between UV-dose to one MMD, skin type and pre-exposure skin pigmentation. After five UV-exposures the positive linear correlation between UV-dose and MMD and skin type was only significant for narrow band UVB, pre-exposure skin pigmentation was significant also for Solar Simulator. For UVA and particularly UVA1 the MMD was independent of pre-exposure pigmentation. The number of SED to MMD is therefore almost the same for very fair-skinned and dark-skinned persons. Pre-exposure pigmentation was clearly more predictive of MMD than skin type. 50% of MMD equals a pigmentation increase of 1%. The shorter the wavelengths the higher the SED to produce MMD. Solar was the least melanogenic and UVA1 the most melanogenic. For the UVB-sources a higher dose was needed the more pigmented the skin. For UVA the MMD was independent of pre-exposure pigmentation.

Oral microbial community typing of caries and pigment in primary dentition.

PubMed

Li, Yanhui; Zou, Cheng-Gang; Fu, Yu; Li, Yanhong; Zhou, Qing; Liu, Bo; Zhang, Zhigang; Liu, Juan

2016-08-05

Black extrinsic discoloration in primary dentition is a common clinical and aesthetic problem that can co-occur with dental caries, the most common oral diseases in childhood. Although the role of bacteria in the formation of pigment and caries in primary dentition is important, their basic features still remain a further mystery. Using targeted sequencing of the V1-V3 hypervariable regions of bacterial 16S ribosomal RNA (rRNA) genes, we obtained a dataset consisting of 831,381 sequences from 111 saliva samples and 110 supragingival plaque samples from 40 patients with pigment (black extrinsic stain), 20 with caries (obvious decay), and 25 with both pigment and caries and from 26 healthy individuals. We applied a Dirichlet multinomial mixture (DMM)-based community typing approach to investigate oral microbial community types. Our results revealed significant structural segregation of microbial communities, as indicated by the identification of two plaque community types (A and B) and three saliva community types (C-E). We found that the independent occurrence of the two plaque community types, A and B, was potentially associated with our oral diseases of interest. For type A, three co-occurring bacterial genus pairs could separately play a potential role in the formation of pigment (Leptotrichia and Fusobacterium), caries (unclassified Gemellales and Granulicatella), and mixed caries and pigment (Streptococcus and Mogibacterium). For type B, three co-occurring bacterial genera (unclassified Clostridiaceae, Peptostreptococcus, and Clostridium) were related to mixed pigment and caries. Three dominant bacterial genera (Selenomonas, Gemella, and Streptobacillus) were linked to the presence of caries. Our study demonstrates that plaque-associated oral microbial communities could majorly contribute to the formation of pigment and caries in primary dentition and suggests potential clinical applications of monitoring oral microbiota as an indicator for disease diagnosis and prognosis.

Multimodal imaging of bilateral diffuse uveal melanocytic proliferation associated with an iris mass lesion.

PubMed

Naysan, Jonathan; Pang, Claudine E; Klein, Robert W; Freund, K Bailey

2016-01-01

Bilateral diffuse uveal melanocytic proliferation (BDUMP) is a rare, paraneoplastic syndrome characterized by bilateral painless visual loss and proliferation of choroidal melanocytes in association with an underlying systemic malignancy. We report a case of bilateral diffuse uveal melanocytic proliferation associated with an underlying gynecological malignancy that also features the infrequent finding of an iris mass lesion, using multimodal imaging including ultra-widefield imaging, spectral domain and swept-source optical coherence tomography. A 59-year-old white female with a prior history of gynecological malignancy in remission presented with progressive bilateral visual loss over several weeks. The patient was noted to have a focal iris mass lesion in her right eye. Ultra-widefield color fundus photography showed a characteristic bilateral 'giraffe pattern' of pigmentary changes extending into the periphery as well as multiple discrete deeply pigmented lesions. Ultra-widefield autofluorescence was useful for visualizing the full extent of involvement. Indocyanine green angiography helped to demarcate the discrete pigmented choroidal lesions. Swept-source OCT clearly delineated the alternating zones of retinal pigment epithelium (RPE) thickening and RPE loss, as well as the prominent choroidal infiltration and thickening. BDUMP is an important diagnosis to consider in the presence of multiple discrete melanocytic choroidal lesions, diffuse choroidal thickening, characteristic RPE changes, iris mass lesions and exudative retinal detachment. Ultra-widefield imaging may demonstrate more extensive lesions than that detected on clinical examination or standard field imaging. Imaging with SS-OCT shows choroidal and RPE characteristics that correlate well with known histopathology of this entity.

Functional Angucycline-Like Antibiotic Gene Cluster in the Terminal Inverted Repeats of the Streptomyces ambofaciens Linear Chromosome

PubMed Central

Pang, Xiuhua; Aigle, Bertrand; Girardet, Jean-Michel; Mangenot, Sophie; Pernodet, Jean-Luc; Decaris, Bernard; Leblond, Pierre

2004-01-01

Streptomyces ambofaciens has an 8-Mb linear chromosome ending in 200-kb terminal inverted repeats. Analysis of the F6 cosmid overlapping the terminal inverted repeats revealed a locus similar to type II polyketide synthase (PKS) gene clusters. Sequence analysis identified 26 open reading frames, including genes encoding the β-ketoacyl synthase (KS), chain length factor (CLF), and acyl carrier protein (ACP) that make up the minimal PKS. These KS, CLF, and ACP subunits are highly homologous to minimal PKS subunits involved in the biosynthesis of angucycline antibiotics. The genes encoding the KS and ACP subunits are transcribed constitutively but show a remarkable increase in expression after entering transition phase. Five genes, including those encoding the minimal PKS, were replaced by resistance markers to generate single and double mutants (replacement in one and both terminal inverted repeats). Double mutants were unable to produce either diffusible orange pigment or antibacterial activity against Bacillus subtilis. Single mutants showed an intermediate phenotype, suggesting that each copy of the cluster was functional. Transformation of double mutants with a conjugative and integrative form of F6 partially restored both phenotypes. The pigmented and antibacterial compounds were shown to be two distinct molecules produced from the same biosynthetic pathway. High-pressure liquid chromatography analysis of culture extracts from wild-type and double mutants revealed a peak with an associated bioactivity that was absent from the mutants. Two additional genes encoding KS and CLF were present in the cluster. However, disruption of the second KS gene had no effect on either pigment or antibiotic production. PMID:14742212

A rare type of Usher's syndrome.

PubMed

Antunica, Antonela Gverović; Kastelan, Snjezana; Bućan, Kajo; Ivanković, Mira; Radman, Maja; Karaman, Ksenija

2013-12-01

A case is presented of a very rare type of Usher's syndrome detected in a 30-year-old woman in her 28th week of pregnancy. She reported left eye visual impairment with a one-month history. She underwent standard ophthalmologic examination with additional procedures scheduled after childbirth, including fluorescein angiography, visual field (Goldman and Octopus) and electroretinography. Fundus examination revealed pallor of the optic disk, diffuse retinal blood vessel narrowing, no retinal pigmentation, left macular edema, vitreous liquefaction, and posterior vitreous detachment. Goldman perimetry showed narrowing of all isopters to 10 degrees, and Octopus perimetry showed peripheral decrease of retinal sensitivity. Electroretinography confirmed the diagnosis of retinitis pigmentosa sine pigmento. Upon collecting case history records, hearing disorders originating from childhood were discovered. To our knowledge, this type of retinitis in Usher's syndrome has been reported only once in the available literature.

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Distinct interactions of Sox5 and Sox10 in fate specification of pigment cells in medaka and zebrafish

PubMed Central

Nagao, Yusuke; Takada, Hiroyuki; Miyadai, Motohiro; Adachi, Tomoko; Kamei, Yasuhiro; Hara, Ikuyo; Naruse, Kiyoshi; Hibi, Masahiko

2018-01-01

Mechanisms generating diverse cell types from multipotent progenitors are fundamental for normal development. Pigment cells are derived from multipotent neural crest cells and their diversity in teleosts provides an excellent model for studying mechanisms controlling fate specification of distinct cell types. Zebrafish have three types of pigment cells (melanocytes, iridophores and xanthophores) while medaka have four (three shared with zebrafish, plus leucophores), raising questions about how conserved mechanisms of fate specification of each pigment cell type are in these fish. We have previously shown that the Sry-related transcription factor Sox10 is crucial for fate specification of pigment cells in zebrafish, and that Sox5 promotes xanthophores and represses leucophores in a shared xanthophore/leucophore progenitor in medaka. Employing TILLING, TALEN and CRISPR/Cas9 technologies, we generated medaka and zebrafish sox5 and sox10 mutants and conducted comparative analyses of their compound mutant phenotypes. We show that specification of all pigment cells, except leucophores, is dependent on Sox10. Loss of Sox5 in Sox10-defective fish partially rescued the formation of all pigment cells in zebrafish, and melanocytes and iridophores in medaka, suggesting that Sox5 represses Sox10-dependent formation of these pigment cells, similar to their interaction in mammalian melanocyte specification. In contrast, in medaka, loss of Sox10 acts cooperatively with Sox5, enhancing both xanthophore reduction and leucophore increase in sox5 mutants. Misexpression of Sox5 in the xanthophore/leucophore progenitors increased xanthophores and reduced leucophores in medaka. Thus, the mode of Sox5 function in xanthophore specification differs between medaka (promoting) and zebrafish (repressing), which is also the case in adult fish. Our findings reveal surprising diversity in even the mode of the interactions between Sox5 and Sox10 governing specification of pigment cell types in medaka and zebrafish, and suggest that this is related to the evolution of a fourth pigment cell type. PMID:29621239

Preparation of an anionic azo pigment-pillared layered double hydroxide and the thermo- and photostability of the resulting intercalated material

NASA Astrophysics Data System (ADS)

Guo, Shengchang; Li, Dianqing; Zhang, Weifeng; Pu, Min; Evans, David G.; Duan, Xue

2004-12-01

A large anionic pigment has been intercalated into a layered double hydroxide (LDH) host by ion-exchange of an Mg/Al LDH-nitrate precursor with a solution of C.I. Pigment Red 48:2 (the calcium salt of 4-((5-chloro-4-methyl-2-sulfophenyl)azo)-3-hydroxy-2-naphthalene-carboxylic acid), in ethane-1,2-diol. After intercalation of the pigment, the interlayer distance in the LDH increases from 0.86 to 1.72 nm. Infrared spectra and TG-DTA curves reveal the presence of a complex system of supramolecular host-guest interactions. The UV-visible diffuse reflectance spectra of C.I. Pigment Red 48:2 show marked changes after heating at 200 °C and above, whereas there are no significant changes in the spectra of the intercalated pigment after heating at temperatures up to 300 °C, showing that the thermostability is markedly enhanced by intercalation in the LDH host. The pigment-intercalated LDHs exhibits much higher photostability to UV light than the pristine pigment, in the case of both the pure solids and their composites with polypropylene, as shown by measurement of CIE 1976 L*a*b* color difference ( ΔE) values.

Advanced pigment dispersion glaucoma secondary to phakic intraocular collamer lens implant.

PubMed

Ye, Clara; Patel, Cajal K; Momont, Anna C; Liu, Yao

2018-06-01

We report a case of pigment dispersion glaucoma secondary to uncomplicated phakic intraocular collamer lens (ICL) (Visian ICL™, Staar Inc., Monrovia, CA) implant that resulted in advanced visual field loss. A 50-year-old man presented for routine follow-up status post bilateral phakic intraocular collamer lens (ICL) placement 8 years earlier. He was incidentally found to have a decline in visual acuity from an anterior subcapsular cataract and elevated intraocular pressure (IOP) in the left eye. There were signs of pigment dispersion and no evidence of angle closure. Diffuse optic nerve thinning was consistent with advanced glaucomatous visual field defects. Pigment dispersion was also present in the patient's right eye, but without elevated IOP or visual field defects. The patient was treated with topical glaucoma medications and the phakic ICL in the left eye was removed concurrently with cataract surgery to prevent further visual field loss. Pigment dispersion glaucoma is a serious adverse outcome after phakic ICL implantation and regular post-operative monitoring may prevent advanced visual field loss.

Nature and origin of the violet stains on the walls of a Roman tomb.

PubMed

Dominguez-Moñino, Irene; Diaz-Herraiz, Marta; Jurado, Valme; Laiz, Leonila; Miller, Ana Z; Santos, Juan Luis; Alonso, Esteban; Saiz-Jimenez, Cesareo

2017-11-15

The Circular Mausoleum tomb (Roman Necropolis of Carmona, Spain) dates back from the first century AD and is characterized by a dense microbial (phototrophic) colonization on the walls and ceiling. However, some walls exhibited an important number of violet stains of unknown origin. The microbial communities of these violet stains are mainly composed of cyanobacteria, streptomycetes and fungi. A strain of Streptomyces parvus, isolated from the walls, produces a violet pigment in culture media. High performance liquid chromatography-mass spectrometry of the culture extracts obtained from this Streptomyces revealed the presence of a few granaticins, pigments with a benzoisochromanequinone structure. When metabolically active in the tomb, S. parvus synthesizes the pigments that diffuse into the mortar. During rain and/or wetting periods, the pigments are solubilized by alkaline waters and elute from the starting position to the surrounding mortar, enlarging the pigmented area and thus contributing to this exceptional biodeterioration phenomenon. Copyright © 2017 Elsevier B.V. All rights reserved.

Adaptation of cone pigments found in green rods for scotopic vision through a single amino acid mutation

PubMed Central

Kojima, Keiichi; Matsutani, Yuki; Yamashita, Takahiro; Yanagawa, Masataka; Imamoto, Yasushi; Yamano, Yumiko; Wada, Akimori; Hisatomi, Osamu; Nishikawa, Kanto; Sakurai, Keisuke; Shichida, Yoshinori

2017-01-01

Most vertebrate retinas contain a single type of rod for scotopic vision and multiple types of cones for photopic and color vision. The retinas of certain amphibian species uniquely contain two types of rods: red rods, which express rhodopsin, and green rods, which express a blue-sensitive cone pigment (M1/SWS2 group). Spontaneous activation of rhodopsin induced by thermal isomerization of the retinal chromophore has been suggested to contribute to the rod’s background noise, which limits the visual threshold for scotopic vision. Therefore, rhodopsin must exhibit low thermal isomerization rate compared with cone visual pigments to adapt to scotopic condition. In this study, we determined whether amphibian blue-sensitive cone pigments in green rods exhibit low thermal isomerization rates to act as rhodopsin-like pigments for scotopic vision. Anura blue-sensitive cone pigments exhibit low thermal isomerization rates similar to rhodopsin, whereas Urodela pigments exhibit high rates like other vertebrate cone pigments present in cones. Furthermore, by mutational analysis, we identified a key amino acid residue, Thr47, that is responsible for the low thermal isomerization rates of Anura blue-sensitive cone pigments. These results strongly suggest that, through this mutation, anurans acquired special blue-sensitive cone pigments in their green rods, which could form the molecular basis for scotopic color vision with normal red rods containing green-sensitive rhodopsin. PMID:28484015

Pigment compositions are linked to the habitat types in dinoflagellates.

PubMed

Yamada, Norico; Tanaka, Ayumi; Horiguchi, Takeo

2015-11-01

Compared to planktonic species, there is little known about the ecology, physiology, and existence of benthic dinoflagellates living in sandy beach or seafloor environments. In a previous study, we discovered 13(2),17(3)-cyclopheophorbide a enol (cPPB-aE) from sand-dwelling benthic dinoflagellates. This enol had never been detected in phytoplankton despite the fact that it is a chlorophyll a catabolite. We speculated from this discovery that habitat selection might be linked to pigment compositions in dinoflagellates. To test the hypothesis of habitat selection linking to pigment compositions, we conducted extensive analysis of pigments with high performance liquid chromatography (HPLC) for 40 species using 45 strains of dinoflagellates including three habitat types; sand-dwelling benthic forms, tidal pool inhabitants and planktonic species. The 40 dinoflagellates are also able to be distinguished into two types based on their chloroplast origins; red alga-derived secondary chloroplasts and diatom-derived tertiary ones. By plotting the pigments profiles onto three habitats, we noticed that twelve pigments including cPPB-aE were found to occur only in benthic sand-dwelling species of red alga-derived type. The similar tendency was also observed in dinoflagellates with diatom-derived chloroplasts, i.e. additional sixteen pigments including chl c 3 were found only in sand-dwelling forms. This is the first report of the occurrence of chl c 3 in dinoflagellates with diatom-derived chloroplasts. These results clarify that far greater diversity of pigments are produced by the dinoflagellates living in sand regardless of chloroplast types relative to those of planktonic and tidal pool forms. Dinoflagellates seem to produce a part of their pigments in response to their habitats.

On the orientation of stripes in fish skin patterning.

PubMed

Míguez, David G; Muñuzuri, Alberto P

2006-11-20

This paper is focused on the study of the stripes orientation in the fish skin patterns. Based on microscopic observations of the pigment cells behavior at the embryonic stage, the key aspects of the pigmentation process are implemented in an experimental reaction-diffusion system. The experiment consists of a photosensitive Turing pattern of stripes growing directionally in one direction with controlled velocity. Different growth velocities of the system rearrange the stripes in the same three possible orientations observed in the skin of the colored fishes: parallel, oblique, and perpendicular. Our results suggest that the spreading velocity of the pigment cells in the fish dermis selects the orientation in the patterning processes.

Occludin Independently Regulates Permeability under Hydrostatic Pressure and Cell Division in Retinal Pigment Epithelial Cells

PubMed Central

Phillips, Brett E.; Cancel, Limary; Tarbell, John M.; Antonetti, David A.

2008-01-01

Purpose The aim of this study was to determine the function of the tight junction protein occludin in the control of permeability, under diffusive and hydrostatic pressures, and its contribution to the control of cell division in retinal pigment epithelium. Methods Occludin expression was inhibited in the human retinal pigment epithelial cell line ARPE-19 by siRNA. Depletion of occludin was confirmed by Western blot, confocal microscopy, and RT-PCR. Paracellular permeability of cell monolayers to fluorescently labeled 70 kDa dextran, 10 kDa dextran, and 467 Da tetramethylrhodamine (TAMRA) was examined under diffusive conditions or after the application of 10 cm H2O transmural pressure. Cell division rates were determined by tritiated thymidine incorporation and Ki67 immunoreactivity. Cell cycle inhibitors were used to determine whether changes in cell division affected permeability. Results Occludin depletion increased diffusive paracellular permeability to 467 Da TAMRA by 15%, and permeability under hydrostatic pressure was increased 50% compared with control. Conversely, depletion of occludin protein with siRNA did not alter diffusive permeability to 70 kDa and 10 kDa RITC-dextran, and permeability to 70 kDa dextran was twofold lower in occludin-depleted cells under hydrostatic pressure conditions. Occludin depletion also increased thymidine incorporation by 90% and Ki67-positive cells by 50%. Finally, cell cycle inhibitors did not alter the effect of occludin siRNA on paracellular permeability. Conclusions The data suggest that occludin regulates tight junction permeability in response to changes in hydrostatic pressure. Furthermore, these data suggest that occludin also contributes to the control of cell division, demonstrating a novel function for this tight junction protein. PMID:18263810

Fluorescence and reflectance properties of hemoglobin-pigmented skin disorders

NASA Astrophysics Data System (ADS)

Troyanova, P.; Borisova, E.; Avramov, L.

2007-06-01

There has been growing interest in clinical application of laser-induced autofluorescence (LIAF) and reflectance spectroscopy (RS) to differentiate disease from normal surrounding tissue, including skin pathologies. Pigmented cutaneous lesions diagnosis plays important role in clinical practice, as malignant melanoma, which is characterized with greatest mortality from all skin cancer types, must be carefully discriminated form other colorized pathologies. The goals of this work were investigation of cutaneous hemoglobin-pigmented lesions (heamangioma, angiokeratoma, and fibroma) by the methods of LIAFS and RS. Spectra from healthy skin areas near to the lesion were detected to be used posteriori in analysis. Fluorescence and reflectance of cutaneous hemoglobin-pigmented lesions are used to develop criterion for differentiation from other pigmented pathologies. Origins of the spectral features obtained are discussed and determination of lesion types is achieved using selected spectral features. The spectral results, obtained were used to develop multispectral diagnostic algorithms based on the most prominent spectral features from the fluorescence and reflectance spectra of the lesions investigated. In comparison between normal skin and different cutaneous lesion types and between lesion types themselves sensitivities and specificities higher than 90 % were achieved. These results show a perspective possibility to differentiate hemoglobin-pigmented lesions from other pigmented pathologies using non-invasive and real time discrimination procedure.

Enhancing the chroma of pigmented polymers using antireflective surface structures.

PubMed

Clausen, Jeppe S; Christiansen, Alexander B; Kristensen, Anders; Mortensen, N Asger

2013-11-10

In this paper we investigate how the color of a pigmented polymer is affected by reduction of the reflectance at the air-polymer interface. Both theoretical and experimental investigations show modified diffuse-direct reflectance spectra when the reflectance of the surface is lowered. Specifically it is found that the color change is manifested as an increase in chroma, leading to a clearer color experience. The experimental implementation is done using random tapered surface structures replicated in polymer from silicon masters using hot embossing.

Is pigment patterning in fish skin determined by the Turing mechanism?

PubMed

Watanabe, Masakatsu; Kondo, Shigeru

2015-02-01

More than half a century ago, Alan Turing postulated that pigment patterns may arise from a mechanism that could be mathematically modeled based on the diffusion of two substances that interact with each other. Over the past 15 years, the molecular and genetic tools to verify this prediction have become available. Here, we review experimental studies aimed at identifying the mechanism underlying pigment pattern formation in zebrafish. Extensive molecular genetic studies in this model organism have revealed the interactions between the pigment cells that are responsible for the patterns. The mechanism discovered is substantially different from that predicted by the mathematical model, but it retains the property of 'local activation and long-range inhibition', a necessary condition for Turing pattern formation. Although some of the molecular details of pattern formation remain to be elucidated, current evidence confirms that the underlying mechanism is mathematically equivalent to the Turing mechanism. Copyright © 2014 Elsevier Ltd. All rights reserved.

Absorption of Bile Pigments by the Gall Bladder*

PubMed Central

Ostrow, J. Donald

1967-01-01

A technique is described for preparation in the guinea pig of an in situ, isolated, vascularized gall bladder that exhibits normal absorptive functions. Absorption of labeled bile pigments from the gall bladder was determined by the subsequent excretion of radioactivity in hepatic bile. Over a wide range of concentrations, unconjugated bilirubin-14C was well absorbed, whereas transfer of conjugated bilirubin proceeded slowly. Mesobilirubinogen-3H was absorbed poorly from whole bile, but was absorbed as rapidly as unconjugated bilirubin from a solution of pure conjugated bile salt. Bilirubin absorption was not impaired by iodoacetamide, 1.5 mM, or dinitrophenol, 1.0 mM, even though water transport was affected. This indicated that absorption of bilirubin was not dependent upon water transport, nor upon energy-dependent processes. The linear relationship between absorption and concentration of pigment at low concentrations in bile salt solutions suggested that pigment was transferred by passive diffusion. At higher pigment concentrations or in whole bile, this simple relationship was modified by interactions of pigment with bile salts and other constituents of bile. These interactions did not necessarily involve binding of bilirubin in micelles. The slow absorption of the more polar conjugates and photo-oxidative derivatives of bilirubin suggested that bilirubin was absorbed principally by nonionic, and partially, by ionic diffusion. Concentrations of pure conjugated bile salts above 3.5 mM were found to be injurious to the gall bladder mucosa. This mucosal injury did not affect the kinetics of bilirubin absorption. During in vitro incubation of bile at 37°C, decay of bilirubin and hydrolysis of the conjugate proceeded as first-order reactions. The effects of these processes on the kinetics of bilirubin absorption, and their possible role in the formation of “white bile” and in the demonstrated appearance of unconjugated bilirubin in hepatic bile, are discussed. PMID:6074006

Skin Color and Pigmentation in Ethnic Skin.

PubMed

Visscher, Marty O

2017-02-01

Skin coloration is highly diverse, partly due to the presence of pigmentation. Color variation is related to the extent of ultraviolet radiation exposure, as well as other factors. Inherent skin coloration arises from differences in basal epidermal melanin amount and type. Skin color is influenced by both the quantity and distribution of melanocytes. The effectiveness of inherent pigmentation for protecting living cells also varies. This article discusses skin color, pigmentation, and ethnicity in relation to clinical practice. Color perception, skin typing/classification, and quantitation of pigmentation are reviewed in relation to ethnicity, environmental stresses/irritants, and potential treatment effects. Copyright © 2016 Elsevier Inc. All rights reserved.

Atomic force microscopy and scanning electron microscopy analysis of daily disposable limbal ring contact lenses.

PubMed

Lorenz, Kathrine Osborn; Kakkassery, Joseph; Boree, Danielle; Pinto, David

2014-09-01

Limbal ring (also known as 'circle') contact lenses are becoming increasingly popular, especially in Asian markets because of their eye-enhancing effects. The pigment particles that give the eye-enhancing effects of these lenses can be found on the front or back surface of the contact lens or 'enclosed' within the lens matrix. The purpose of this research was to evaluate the pigment location and surface roughness of seven types of 'circle' contact lenses. Scanning electron microscopic (SEM) analysis was performed using a variable pressure Hitachi S3400N instrument to discern the placement of lens pigments. Atomic force microscopy (Dimension Icon AFM from Bruker Nano) was used to determine the surface roughness of the pigmented regions of the contact lenses. Atomic force microscopic analysis was performed in fluid phase under contact mode using a Sharp Nitride Lever probe (SNL-10) with a spring constant of 0.06 N/m. Root mean square (RMS) roughness values were analysed using a generalised linear mixed model with a log-normal distribution. Least square means and their corresponding 95% confidence intervals were estimated for each brand, location and pigment combination. SEM cross-sectional images at 500× and 2,000× magnification showed pigment on the surface of six of the seven lens types tested. The mean depth of pigment for 1-DAY ACUVUE DEFINE (1DAD) lenses was 8.1 μm below the surface of the lens, while the remaining lens types tested had pigment particles on the front or back surface. Results of the atomic force microscopic analysis indicated that 1DAD lenses had significantly lower root mean square roughness values in the pigmented area of the lens than the other lens types tested. SEM and AFM analysis revealed pigment on the surface of the lens for all types tested with the exception of 1DAD. Further research is required to determine if the difference in pigment location influences on-eye performance. © 2014 The Authors. Clinical and Experimental Optometry © 2014 Optometrists Association Australia.

Atomic force microscopy and scanning electron microscopy analysis of daily disposable limbal ring contact lenses

PubMed Central

Lorenz, Kathrine Osborn; Kakkassery, Joseph; Boree, Danielle; Pinto, David

2014-01-01

Background Limbal ring (also known as ‘circle’) contact lenses are becoming increasingly popular, especially in Asian markets because of their eye-enhancing effects. The pigment particles that give the eye-enhancing effects of these lenses can be found on the front or back surface of the contact lens or ‘enclosed’ within the lens matrix. The purpose of this research was to evaluate the pigment location and surface roughness of seven types of ‘circle’ contact lenses. Methods Scanning electron microscopic (SEM) analysis was performed using a variable pressure Hitachi S3400N instrument to discern the placement of lens pigments. Atomic force microscopy (Dimension Icon AFM from Bruker Nano) was used to determine the surface roughness of the pigmented regions of the contact lenses. Atomic force microscopic analysis was performed in fluid phase under contact mode using a Sharp Nitride Lever probe (SNL-10) with a spring constant of 0.06 N/m. Root mean square (RMS) roughness values were analysed using a generalised linear mixed model with a log-normal distribution. Least square means and their corresponding 95% confidence intervals were estimated for each brand, location and pigment combination. Results SEM cross-sectional images at 500× and 2,000× magnification showed pigment on the surface of six of the seven lens types tested. The mean depth of pigment for 1-DAY ACUVUE DEFINE (1DAD) lenses was 8.1 μm below the surface of the lens, while the remaining lens types tested had pigment particles on the front or back surface. Results of the atomic force microscopic analysis indicated that 1DAD lenses had significantly lower root mean square roughness values in the pigmented area of the lens than the other lens types tested. Conclusions SEM and AFM analysis revealed pigment on the surface of the lens for all types tested with the exception of 1DAD. Further research is required to determine if the difference in pigment location influences on-eye performance. PMID:24689948

Fungal and Bacterial Pigments: Secondary Metabolites with Wide Applications

PubMed Central

Narsing Rao, Manik Prabhu; Xiao, Min; Li, Wen-Jun

2017-01-01

The demand for natural colors is increasing day by day due to harmful effects of some synthetic dyes. Bacterial and fungal pigments provide a readily available alternative source of naturally derived pigments. In contrast to other natural pigments, they have enormous advantages including rapid growth, easy processing, and independence of weather conditions. Apart from colorant, bacterial and fungal pigments possess many biological properties such as antioxidant, antimicrobial and anticancer activity. This review outlines different types of pigments. It lists some bacterial and fungal pigments and current bacterial and fungal pigment status and challenges. It also focuses on possible fungal and bacterial pigment applications. PMID:28690593

XRF and UV-Vis-NIR analyses of medieval wall paintings of al-Qarawiyyin Mosque (Morocco)

NASA Astrophysics Data System (ADS)

Fikri, I.; El Amraoui, M.; Haddad, M.; Ettahiri, A. S.; Bellot-Gurlet, L.; Falguères, C.; Lebon, M.; Nespoulet, R.; Ait Lyazidi, S.; Bejjit, L.

2018-05-01

Medieval wall painting fragments, taken at the medieval Mosque of al-Qarawiyyin in Fez, have been investigated by means of X-ray fluorescence and UV-Vis-NIR diffuse reflectance spectroscopies. The analyses permitted to determine the palette of pigments used by craftsmen of the time. Hematite or red ochre were used to obtain red brown colours, calcite for white, copper-based pigments for blue and blue-grey shades while a mixture of cinnabar, lead-based pigments and hematite was adopted to make red-orange colours. Furthermore, the analysis of mortars (external layer and plaster) on these wall painting samples revealed that they are composed mainly by calcite and sometimes by additional compounds such as quartz and gypsum.

On-line database of voltammetric data of immobilized particles for identifying pigments and minerals in archaeometry, conservation and restoration (ELCHER database).

PubMed

Doménech-Carbó, Antonio; Doménech-Carbó, María Teresa; Valle-Algarra, Francisco Manuel; Gimeno-Adelantado, José Vicente; Osete-Cortina, Laura; Bosch-Reig, Francisco

2016-07-13

A web-based database of voltammograms is presented for characterizing artists' pigments and corrosion products of ceramic, stone and metal objects by means of the voltammetry of immobilized particles methodology. Description of the website and the database is provided. Voltammograms are, in most cases, accompanied by scanning electron microphotographs, X-ray spectra, infrared spectra acquired in attenuated total reflectance Fourier transform infrared spectroscopy mode (ATR-FTIR) and diffuse reflectance spectra in the UV-Vis-region. For illustrating the usefulness of the database two case studies involving identification of pigments and a case study describing deterioration of an archaeological metallic object are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

Rayleigh matches in carriers of inherited color vision defects: the contribution from the third L/M photopigment.

PubMed

Sun, Yang; Shevell, Steven K

2008-01-01

The mother or daughter of a male with an X-chromosome-linked red/green color defect is an obligate carrier of the color deficient gene array. According to the Lyonization hypothesis, a female carrier's defective gene is expressed and thus carriers may have more than two types of pigments in the L/M photopigment range. An open question is how a carrier's third cone pigment in the L/M range affects the postreceptoral neural signals encoding color. Here, a model considered how the signal from the third pigment pools with signals from the normal's two pigments in the L/M range. Three alternative assumptions were considered for the signal from the third cone pigment: it pools with the signal from (1) L cones, (2) M cones, or (3) both types of cones. Spectral-sensitivity peak, optical density, and the relative number of each cone type were factors in the model. The model showed that differences in Rayleigh matches among carriers can be due to individual differences in the number of the third type of L/M cone, and the spectral sensitivity peak and optical density of the third L/M pigment; surprisingly, however, individual differences in the cone ratio of the other two cone types (one L and the other M) did not affect the match. The predicted matches were compared to Schmidt's (1934/1955) report of carriers' Rayleigh matches. For carriers of either protanomaly or deuteranomaly, these matches were not consistent with the signal from the third L/M pigment combining with only the signal from M cones. The matches could be accounted for by pooling the third-pigment's response with L-cone signals, either exclusively or randomly with M-cone responses as well.

Purification and molecular and biological characterisation of the 1-hydroxyphenazine, produced by an environmental strain of Pseudomonas aeruginosa.

PubMed

Prabhu, Meghanath S; Walawalkar, Yogesh D; Furtado, Irene

2014-12-01

Pseudomonas aeruginosa--an opportunistic pathogen, perhaps best known for chronic lung infections, produces wide range of pigments that possess specific activities which either assist the organism's survival or bring about changes within host. A similar blue-green diffusible pigment producing P. aeruginosa was isolated from dug-well water, so as to extract 1-hydroxyphenazine from its crude pigment. The compound was purified from the crude pigment using column chromatography followed by a preparative thin layer chromatography that showed a single yellow spot. Further molecular characterisation of the purified component was carried out using UV-Vis spectrophotometer, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and mass spectroscopy which showed respective peaks corresponding to 1-hydroxyphenazine. Biological characterisation using in vitro assays revealed that 1-hydroxyphenazine showed anti-bacterial activity only against Bacillus sp. and a concentration of 30 µg/ml induced noticeable morphological alteration in A549 human lung adenocarcinoma cells followed by cell death after 48 h. Thus, such active components within bacterial pigments can be characterized and used as possible anti-bacterial or anti-cancer agents.

Assessing human skin with diffuse reflectance spectroscopy and colorimetry

NASA Astrophysics Data System (ADS)

Seo, InSeok; Liu, Yang; Bargo, Paulo R.; Kollias, Nikiforos

2012-02-01

Colorimetry has been used as an objective measure of perceived skin color by human eye to document and score physiological responses of the skin from external insults. CIE color space values (L*, a* and b*) are the most commonly used parameters to correlate visually perceived color attributes such as L* for pigment, a* for erythema, and b* for sallowness of the skin. In this study, we investigated the relation of Lab color scale to the amount of major skin chromophores (oxy-, deoxyhemoglobin and melanin) calculated from diffuse reflectance spectroscopy. Thirty two healthy human subjects with ages from 20 to 70 years old, skin types I-VI, were recruited for the study. DRS and colorimetry measurements were taken from the left and right cheeks, and on the right upper inner arm. The melanin content calculated from 630-700 nm range of DRS measurements was shown to correlate with the lightness of skin (L*) for most skin types. For subjects with medium-to-light complexion, melanin measured at the blue part spectrum and hemoglobin interfered on the relation of lightness of the skin color to the melanin content. The sallowness of the skin that is quantified by the melanin contribution at the blue part spectrum of DRS was found to be related to b* scale. This study demonstrates the importance of documenting skin color by assessing individual skin chromophores with diffuse reflectance spectroscopy, in comparison to colorimetry assessment.

[Clinical aspects and therapy of lymphangiomas, hemangiomas and nevi in the area of the head and neck].

PubMed

Drepper, H

1985-07-01

The superficial angiomas and nevi arise from the endothelial cells, the pigment-cell-system or the epidermal cells. Hemangiomas are benign tumours of the endothelial cells appearing predominantly in female newborn infants. Depending on localisation, growth and proliferation there is a tendency for spontaneous involution. For irreversible dysfunction or anatomical deformities surgical resection during the growth phase of the hemangioma is indicated. Surgery may be necessary to improve the functional and esthetic appearance after spontaneous involution causing loose residual skin. Radiotherapy of the lesion is rarely indicated. Systemic steroid therapy in cooperation with the pediatrician should be reserved only for desperate cases such as Kasabach-Merrit-Syndrome. Port wine nevi without scars can be covered with skin tanning cosmetics. Argon-Laser-Therapy is not yet so selective that healing can be achieved with certainty and without scars. Clinical progression requires surgery, especially for racemose angiectasia. Arterial embolization should only be used under special conditions, and then only as pretreatment. Lymphangiomas are mostly angiectatic processes, especially of lymphatic vascular tissue and vessels. Even large cystic lymphangiomas can be treated quite well by surgery, but operations on large diffuse invasive lymphangiomas often cause lymphedema and infection similar to erysipelas leading to pseudorecurrence. The benign malformations of the pigment cell system require clear differentiation from malignant melanoma and its precursors. Malignant melanoma develops more frequently from congenital nevi of the deep type than from other pigmented lesions. Malignant melanomas arising from giant nevi are usually diagnosed too late so that almost all patients die. Removal of giant nevi as early as possible is recommended. The epidermal malformations, too, need accurate diagnosis. Multisymptomatic syndromes such as the Basal-Cell-Nevus-Syndrome, and vascular and pigment cell abnormalities require special care.

Clinical outcome of radiosynoviorthesis: a meta-analysis including 2190 treated joints.

PubMed

Kresnik, E; Mikosch, P; Gallowitsch, H J; Jesenko, R; Just, H; Kogler, D; Gasser, J; Heinisch, M; Unterweger, O; Kumnig, G; Gomez, I; Lind, P

2002-07-01

A variety of indications for radiosynoviorthesis have been reported in literature, but the clinical outcome differs and depends on the primary disease and the pre-existing degenerative changes. This metaanalysis was carried out to establish groups for radiosynoviorthesis based on clinical outcome with respect to primary disease, clinical stage and the pre-existing degenerative changes. The literature search was carried out using the MEDLINE search term 'radionuclide synovectomy'. Based on reports in the literature we determined groups for radiosynoviorthesis for clinical use. Our literature list comprised 2190 joints that were treated with radiosynoviorthesis. The overall response rate for all treated joints was 72.5+/-17%. The mean improvement rate for the treated joints in rheumatoid arthritis was 66.7+/-15.4%. For osteoarthritis the success rate was 56+/-11%, with better results in case of minimal radiological changes. Radiosynoviorthesis in patients with changes according to Steinbrocker I and II was successful in 72.8+/-12.3%, and in 64+/-17.3%, respectively. Steinbrocker III and IV had a mean success rate of 52.4+/-23.6%. In the case of haemophilia and Willebrand's disease a reduction of joint bleedings and factor usages after radiosynoviorthesis was evident in 91+/-4.3%. In patients with pigmented villonodular synovitis radiosynoviorthesis was successful in 77.3+/-25.3%. It is concluded that radiosynoviorthesis provides better results in rheumatoid arthritis than in osteoarthritis. Minimal or moderate changes according to Steinbrocker stages I and II respond better to radionuclide therapy than do stages III and IV. Deformed or unstable joints might fail treatment and therefore surgical interventions should be considered. Close cooperation with orthopaedists and rheumatologists is necessary to consider radiosynoviorthesis in each patient to ensure optimal medical care.

Identification of organic pigments in tattoo inks and permanent make-up using laser desorption ionisation mass spectrometry

PubMed Central

Niederer, Markus; Hauri, Urs; Kroll, Lydia; Hohl, Christopher

2018-01-01

Nowadays, about 12% of the European and 20% of the US population are tattooed. Rising concerns regarding consumer safety, led to legal restrictions on tattoo and permanent make-up (PMU) inks. Restrictions also include bans on certain colourants. Both ink types use organic pigments for colour-giving, plus inorganic pigments for white and black and colour tones. Pigments are only sparingly soluble in common solvents and occur as suspended particles in the ink matrix. Their detection and identification therefore pose a major challenge for laboratories involved in monitoring the legal compliance of tattoo inks and PMU. We overcame this challenge by developing a direct laser desorption ionisation time-of-flight mass spectrometry method, which included an easy sample clean up. The method proved to be capable of detecting and identifying organic pigments in almost all of the tested ink samples. Method validation and routine deployment during market surveys showed the method to be fit for purpose. Pigment screening of 396 tattoo inks and 55 PMU taken from the Swiss market between 2009 and 2017 lead to the following conclusions: Pigment variety is much greater in tattoo inks (18) than in PMU (10); four prohibited pigments (Pigment Green 7, Pigment Red 122, Pigment Violet 19 and 23) were found in both ink types; for PMU, these four pigments made up 12% of the pigment findings, compared to 32% for tattoo inks. Therefore, legal compliance of PMU was at a higher level. A comparison of pigments found with those declared on tattoo ink labels clearly showed that banned pigments are rarely declared, but rather masked by listing non present legal pigments and label forging; therefore, highlighting the urgency of widespread market controls. PMID:29259773

Identification of organic pigments in tattoo inks and permanent make-up using laser desorption ionisation mass spectrometry.

PubMed

Niederer, Markus; Hauri, Urs; Kroll, Lydia; Hohl, Christopher

2017-01-01

Nowadays, about 12% of the European and 20% of the US population are tattooed. Rising concerns regarding consumer safety, led to legal restrictions on tattoo and permanent make-up (PMU) inks. Restrictions also include bans on certain colourants. Both ink types use organic pigments for colour-giving, plus inorganic pigments for white and black and colour tones. Pigments are only sparingly soluble in common solvents and occur as suspended particles in the ink matrix. Their detection and identification therefore pose a major challenge for laboratories involved in monitoring the legal compliance of tattoo inks and PMU. We overcame this challenge by developing a direct laser desorption ionisation time-of-flight mass spectrometry method, which included an easy sample clean up. The method proved to be capable of detecting and identifying organic pigments in almost all of the tested ink samples. Method validation and routine deployment during market surveys showed the method to be fit for purpose. Pigment screening of 396 tattoo inks and 55 PMU taken from the Swiss market between 2009 and 2017 lead to the following conclusions: Pigment variety is much greater in tattoo inks (18) than in PMU (10); four prohibited pigments (Pigment Green 7, Pigment Red 122, Pigment Violet 19 and 23) were found in both ink types; for PMU, these four pigments made up 12% of the pigment findings, compared to 32% for tattoo inks. Therefore, legal compliance of PMU was at a higher level. A comparison of pigments found with those declared on tattoo ink labels clearly showed that banned pigments are rarely declared, but rather masked by listing non present legal pigments and label forging; therefore, highlighting the urgency of widespread market controls.

Dermal Sensitization Potential of Triethyleneglycol Dinitrate (TEGDN) in Guinea Pigs

DTIC Science & Technology

1989-01-01

mutagenicity assay, acute oral toxicity tests in rats and mice, acute dermal toxicity in rabbits, dermal and ocular irritation studies in rabbits, and...conditions: 85E0102 had diffuse tracheitis, mild endocarditis , mild hepatitis, and diffuse pigment granules in the small intestine; 85E0103 had mild...severe ulceration progressing to necrosis. Sensitization is manifested as indirect inflammation mediated by components of the immune system in

An unusual case of ocular melanosis and limbal melanocytoma with benign intraorbital extension in a dog.

PubMed

Dees, D Dustin; Maclaren, Nicole E; Teixeira, Leandro; Dubielzig, Richard R

2013-07-01

This case report describes concurrent ocular melanosis and limbal melanocytoma in a 6-year-old Golden Retriever dog. Three years prior, the pet was examined for progressive corneal pigmentation and started on topical Tacrolimus but was subsequently lost to followup. Current ophthalmic examination revealed a large pigmented limbal mass and severe corneal pigmentation of the left eye as well as a small focal raised pigmented mass of the right third eyelid. Due to extent and rapidity of tumor growth, the left eye was removed via transconjunctival enucleation and submitted for histopathologic examination. At the time of surgery, numerous orbital structures including intraorbital fat, extraocular muscles, and portions of the proximal nasolacrimal drainage apparatus contained multifocal areas of black pigmentation. These tissues were subsequently removed and submitted for microscopic analysis. The pigmented mass of the right third eyelid was also excised. Histopathology of the left eye and orbital contents revealed a limbal melanocytoma extending to the bulbar conjunctiva and orbital space forming a large, markedly necrotic mass. Diffuse, severe ocular melanosis, abnormal stromal pigmentation of the sclera and orbital tissues, and corneal stromal pigmentation were noted. The mass of the right third eyelid was confirmed to be a conjunctival melanocytoma. To the authors' knowledge, this is the first report of concurrent ocular melanosis and limbal melanocytoma with orbital infiltration. The peculiar multifocal distribution of melanocytes throughout ocular connective tissues may explain the development of multiple melanocytic lesions in this patient. © 2012 American College of Veterinary Ophthalmologists.

The Comparison Between Nmf and Ica in Pigment Mixture Identification of Ancient Chinese Paintings

NASA Astrophysics Data System (ADS)

Liu, Y.; Lyu, S.; Hou, M.; Yin, Q.

2018-04-01

Since the colour in painting cultural relics observed by our naked eyes or hyperspectral cameras is usually a mixture of several kinds of pigments, the mixed pigments analysis will be an important subject in the field of ancient painting conservation and restoration. This paper aims to find a more effective method to confirm the types of every pure pigment from mixture on the surface of paintings. Firstly, we adopted two kinds of blind source separation algorithms, which are independent component analysis and non-negative matrix factorization, to extract the pure pigment component from mixed spectrum respectively. Moreover, we matched the separated pure spectrum with the pigments spectra library built by our team to determine the pigment type. Furthermore, three kinds of data including simulation data, mixed pigments spectral data measured in laboratory, and the spectral data of an ancient painting were chosen to evaluate the performance of the different algorithms. And the accuracy was compared between the two algorithms. Finally, the experimental results show that non-negative matrix factorization method is more suitable for endmember extraction in the field of ancient painting conservation and restoration.

Features of degradation and recovery of the optical properties of coatings based on ZnO powder modified with nanoparticles after irradiation

NASA Astrophysics Data System (ADS)

Mikhailov, M.; Neschimenko, V.; Sokolovskiy, A.

2018-04-01

The effect of electron irradiation with energy of 30 keV and fluence up to 7 × 1016 cm-2 on diffuse reflection spectra in situ of coatings based on ZnO powders unmodified and modified with zirconium dioxide and aluminum oxide nanopowders was investigated. The higher radiation stability of coatings based on modified pigments in comparison to unmodified pigments has been established. A significant recovery of the reflection spectra of irradiated coatings after exposure to residual vacuum and air was shown.

Epidermal gene expression and ethnic pigmentation variations among individuals of Asian, European and African ancestry.

PubMed

Yin, Lanlan; Coelho, Sergio G; Ebsen, Dominik; Smuda, Christoph; Mahns, Andre; Miller, Sharon A; Beer, Janusz Z; Kolbe, Ludger; Hearing, Vincent J

2014-10-01

Differences in visible skin pigmentation give rise to the wide variation of skin colours seen in racial/ethnic populations. Skin pigmentation is important not only from cosmetic and psychological points of view, but more importantly because of its implications for the risk of all types of skin cancers, on photoaging, etc. Despite differences in those parameters in Caucasian and Asian skin types, they are remarkably similar in their production and distribution of melanins, and the mechanism(s) underlying their different characteristics have remained obscure. In this study, we used microarray analysis of skin suction blisters to investigate molecular differences underlying the determination of pigmentation in various skin types, and we used immunohistochemistry to validate the expression patterns of several interesting targets that were identified. Intriguingly, Caucasian and Asian skins had highly similar gene expression patterns that differed significantly from the pattern of African skin. The results of this study suggest the dynamic interactions of different types of cells in human skin that regulate its pigmentation, reveal that the known pigmentation genes have a limited contribution and uncover a new array of genes, including NINL and S100A4, that might be involved in that regulation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Signal transduction, plasma membrane calcium movements, and pigment translocation in freshwater shrimp chromatophores.

PubMed

Milograna, Sarah Ribeiro; Bell, Fernanda Tinti; McNamara, John Campbell

2010-11-01

Crustacean color change results from the differential translocation of chromatophore pigments, regulated by neurosecretory peptides like red pigment concentrating hormone (RPCH) that, in the red ovarian chromatophores of the freshwater shrimp Macrobrachium olfersi, triggers pigment aggregation via increased cytosolic cGMP and Ca(2+) of both smooth endoplasmatic reticulum (SER) and extracellular origin. However, Ca(2+) movements during RPCH signaling and the mechanisms that regulate intracellular [Ca(2+)] are enigmatic. We investigate Ca(2+) transporters in the chromatophore plasma membrane and Ca(2+) movements that occur during RPCH signal transduction. Inhibition of the plasma membrane Ca(2+)-ATPase by La(3+) and indirect inhibition of the Na(+)/Ca(2+) exchanger by ouabain induce pigment aggregation, revealing a role for both in Ca(2+) extrusion. Ca(2+) channel blockade by La(3+) or Cd(2+) strongly inhibits slow-phase RPCH-triggered aggregation during which pigments disperse spontaneously. L-type Ca(2+) channel blockade by gabapentin markedly reduces rapid-phase translocation velocity; N- or P/Q-type blockade by ω-conotoxin MVIIC strongly inhibits RPCH-triggered aggregation and reduces velocity, effects revealing RPCH-signaled influx of extracellular Ca(2+). Plasma membrane depolarization, induced by increasing external K(+) from 5 to 50 mM, produces Ca(2+)-dependent pigment aggregation, whereas removal of K(+) from the perfusate causes pigment hyperdispersion, disclosing a clear correlation between membrane depolarization and pigment aggregation; K(+) channel blockade by Ba(2+) also partially inhibits RPCH action. We suggest that, during RPCH signal transduction, Ca(2+) released from the SER, together with K(+) channel closure, causes chromatophore membrane depolarization, leading to the opening of predominantly N- and/or P/Q-type voltage-gated Ca(2+) channels, and a Ca(2+)/cGMP cascade, resulting in pigment aggregation.

Volumetric Visualization of Human Skin

NASA Astrophysics Data System (ADS)

Kawai, Toshiyuki; Kurioka, Yoshihiro

We propose a modeling and rendering technique of human skin, which can provide realistic color, gloss and translucency for various applications in computer graphics. Our method is based on volumetric representation of the structure inside of the skin. Our model consists of the stratum corneum and three layers of pigments. The stratum corneum has also layered structure in which the incident light is reflected, refracted and diffused. Each layer of pigment has carotene, melanin or hemoglobin. The density distributions of pigments which define the color of each layer can be supplied as one of the voxel values. Surface normals of upper-side voxels are fluctuated to produce bumps and lines on the skin. We apply ray tracing approach to this model to obtain the rendered image. Multiple scattering in the stratum corneum, reflective and absorptive spectrum of pigments are considered. We also consider Fresnel term to calculate the specular component for glossy surface of skin. Some examples of rendered images are shown, which can successfully visualize a human skin.

The First Report of KRT5 Mutation Underlying Acantholytic Dowling-Degos Disease with Mottled Hypopigmentation in an Indian Family

PubMed Central

Verma, Shyam; Pasternack, Sandra M.; Rütten, Arno; Ruzicka, Thomas; Betz, Regina C.; Hanneken, Sandra

2014-01-01

Galli Galli disease (GGD) is the name given to a rare form of acantholytic Dowling-Degos disease. (DDD), the latter itself being a rare condition. We believe we are describing for the first time in Indian dermatologic literature a case of GGD in a family where 25 persons have DDD and have been able to document a KRT5 mutation in four members of the family. Whereas reticulate pigmentation is a hallmark of DDD there are rare reports of mottled pigmentation with multiple asymptomatic hypopigmented macules scattered diffusely along with the pigmentation. All the cases described here show a mottled pigmentation comprising hypo and hyperpigmented asymptomatic macules. After the clinical diagnosis was made by one of the authors (SV) in India, the German authors repeated histological examination and successfully demonstrated a heterozygous nonsense mutation, c.C10T (p.Gln4X), in exon 1 of the KRT5 gene, from various centers in Munich, Bonn, Dusseldorf and Friedrichschafen in Germany. PMID:25284854

Gingival melanin depigmentation by 810 nm diode laser.

PubMed

Elemek, Eser

2018-01-01

The color of gingiva is determined by number and size of blood vessels, thickness of epithelium, keratinization degree, and melanin pigments present in epithelium. Melanocytes, located in basal and suprabasal layers of epithelium, are the cells that produce melanin pigments which play a main role for pigmentation of gingiva. In this case series, the use of 810 nm diode laser for depigmentation of gingiva is presented. Two female patients applied with a chief complaint of "darkened gums" due to heavy smoking. In intraoral examination, diffuse melanin pigmentation was observed in both the maxilla and mandible. Under the local anesthesia, 810 nm diode laser was applied for depigmentation at 1.3 W power in continuous mode. Patients were recalled at weeks 1, 4, and 12 to evaluate the healing and recurrence rate. Both the patients had no postoperative pain or edema, and complete healing was observed at week 12. This study revealed that depigmentation with 810 nm diode laser is successful in terms of esthetics and patient comfort.

Goniochromatic and sparkle properties of effect pigmented samples in multidimensional configuration

NASA Astrophysics Data System (ADS)

Höpe, Andreas; Hauer, Kai-Olaf; Teichert, Sven; Hünerhoff, Dirk; Strothkämper, Christian

2015-03-01

The effects of goniochromatism and sparkle are gaining more and more interest for surface refinement applications driven by demanding requirements from such different branches as automotive, cosmetics, printing and packaging industry. The common background and intention in all of these implementations is improvement of the visual appearance of the related commercial products. Goniochromatic materials show strong angular-dependent reflection characteristics and hence a color impression depending on the effective spatial arrangement of illumination and observation relative to the surface of the artifact. Sparkle is a texture related effect giving a surface which is irradiated directionally, like direct sun light, a bright glittering effect, similar to twinkling stars at the night sky. The prototype for this new effect is the Xirallic® pigment of MERCK KGaA, Germany. The same pigment shows in diffuse irradiation, like on a cloudy day, a different visual effect called graininess (coarseness) which appears as a granular structure of the surface. Both effects were studied on especially manufactured samples of a dilution series in pigment concentration and a tonality series with carbon black. The experiments were carried out with the robot-based gonioreflectometer and integrating sphere facilities at Physikalisch-Technische Bundesanstalt (PTB) in multidimensional configurations of directional and diffuse irradiation. The research is part of the European Metrology Research Program (EMRP), which is a metrology-focused program of coordinated Research & Development (R&D) funded by the European Commission and participating countries within the European Association of National Metrology Institutes (EURAMET). More information and updated news concerning the project can be found on the xD-Reflect website http://www.xdreflect.eu/.

Effect of the interaction of heat-processing style and fat type on the micellarization of lipid-soluble pigments from green and red pungent peppers (Capsicum annuum).

PubMed

Victoria-Campos, Claudia I; Ornelas-Paz, José de Jesús; Yahia, Elhadi M; Failla, Mark L

2013-04-17

The high diversity of carotenoids and chlorophylls in foods contrasts with the reduced number of pigments that typically are investigated in micellarization studies. In this study, pepper samples (raw and heat-treated) contained 68 individual pigments, but only 38 of them were micellarized after in vitro digestion. The micellarization of pigments was majorly determined by the interaction effect of processing style (food matrix effect) and fat type (saturated and unsaturated). The highest micellarization was observed with raw peppers. Unsaturated fat increased the micellarization of carotenoid esters, while the impact of fat on the micellarization of free carotenoids seemed to be dependent on pigment structure. The micellarization efficiency was diminished as the esterification level of carotenoids increased. The type of fatty acid moiety and the polarity of the carotenoids modulated their micellarization. Chlorophylls were transformed into pheophytins by heat-processing and digestion, with the pheophytins being stable under gastrointestinal conditions. Micellarization of pheophytins was improved by fat.

Characterisation of inorganic microparticles in pigment cells of human gut associated lymphoid tissue.

PubMed Central

Powell, J J; Ainley, C C; Harvey, R S; Mason, I M; Kendall, M D; Sankey, E A; Dhillon, A P; Thompson, R P

1996-01-01

Macrophages at the base of human gut associated lymphoid tissue (GALT), become loaded early in life with dark granular pigment that is rich in aluminium, silicon, and titanium. The molecular characteristics, intracellular distribution, and source of this pigment is described. Laser scanning and electron microscopy showed that pigmented macrophages were often closely related to collagen fibres and plasma cells in GALT of both small and large intestine and contained numerous phagolysosomes, previously described as granules, that are rich in electron dense submicron sized particles. Morphological assessment, x ray microanalysis, and image electron energy loss spectroscopy showed three distinct types of microparticle: type I - spheres of titanium dioxide, 100-200 nm diameter, characterised as the synthetic food-additive polymorph anatase; type II - aluminosilicates, < 100-400 nm in length, generally of flaky appearance, often with adsorbed surface iron, and mostly characteristic of the natural clay mineral kaolinite; and type III - mixed environmental silicates without aluminium, 100-700 nm in length and of variable morphology. Thus, this cellular pigment that is partly derived from food additives and partly from the environment is composed of inert inorganic microparticles and loaded into phagolysosomes of macrophages within the GALT of all human subjects. These observations suggest that the pathogenicity of this pigment should be further investigated since, in susceptible individuals, the same intracellular distribution of these three types of submicron particle causes chronic latent granulomatous inflammation. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 PMID:8675092

Monte Carlo Simulation of Visible Light Diffuse Reflection in Neonatal Skin

NASA Astrophysics Data System (ADS)

Atencio, J. A. Delgado; Rodríguez, E. E.; Rodríguez, A. Cornejo; Rivas-Silva, J. F.

2008-04-01

Neonatal jaundice is a medical condition that happens commonly in newborns as result of desbalance between the production and the elimination of the bilirubin. Around 50% of newborns in term and something more of 60% of the near-term becomes jaundiced in the first week of life. This excess of bilirubin in the blood is exhibited in the skin, the sclera of the eyes and the mucous of mouth like a characteristic yellow coloration. In this work we make several numerical simulations of the spectral diffuse reflection for the skin of newborns that present different values of the biological parameters (bilirubin content, grade of pigmentation and content of blood) that characterize it. These simulations will allow us to evaluate the influence of these parameters on the experimental determination of bilirubin by noninvasive optical methods. The simulations are made in the spectral range of 400-700 nm using the Monte Carlo code MCML and two programs developed in LabVIEW by the authors. We simulated the diffuse reflection spectrum of neonatal skin for concentrations of bilirubin in skin that covers an ample range: from physiological to harmful numbers. We considered the influence of factors such as grade of pigmentation and content of blood.

Amelanocytic anhidrotic alopecia areata-like phenotype after allogeneic hematopoietic cell transplant.

PubMed

Kamińska, Edidong Celestine Ntuen; Larson, Richard A; Petronic-Rosic, Vesna

2012-08-01

Diffuse alopecia areata or canities subita is a rare variant of alopecia in which hair loss is associated with regrowth of white hairs and possible lightening of the skin. Preferential loss of pigmented hair in this disorder may be related to the melanin pigment system and/or melanocytes. Acquired generalized anhidrosis can be associated with autoimmune disease, cancer, graft-vs-host disease, or medications or can be idiopathic. Extensive anhidrosis may cause hyperpyrexia on exposure to heat, and protection from overheating is essential. A 38-year-old man with idiopathic autoimmune aplastic anemia developed permanent diffuse skin and hair whitening and generalized anhidrosis after a successful allogeneic hematopoietic stem cell transplant. Results of a histopathologic examination, which has previously not been reported in this disease, demonstrated a complete lack of epidermal and follicular melanocytes and a dense perifollicular and periadnexal lymphocytic infiltrate. The hair- and skin-lightening phenomena in diffuse alopecia areata may be the result of an overstimulated immune system that targets epidermal and follicular melanocytes. Destruction results in irreversible pigmentary loss of the skin. In a patient with multiple risk factors for anhidrosis, a specific cause may be difficult to determine.

The functional morphology of color changing in a spider: development of ommochrome pigment granules.

PubMed

Insausti, Teresita C; Casas, Jérôme

2008-03-01

Studies on the formation of ommochrome pigment granules are very few, despite their generalized occurrence as screening pigments in insect eyes. This is particularly true for ommochrome granules responsible for epidermal coloration. The aims of this study were to characterize the localization of major body pigments in a color changing mimetic spider, Misumena vatia (Thomisidae), and to describe the formation and location of ommochrome pigment granules responsible for the spider's color change from white to yellow. The unpigmented cuticula of this spider is transparent. Both the guanine localized in guanine cells in the opisthosoma and the uric acid localized in epidermis cells in the prosoma are responsible for the white coloration. The bright yellow color is due to the combination of ommochrome pigment granules and the white reflectance from coincident guanine and/or uric acid. The formation of ommochrome pigment granules in epidermis cells proceeds via three distinctive steps. Translucent, UV fluorescent, progranules (type I) are produced by a dense network of endoplasmic reticulum associated with numerous mitochondria and glycogen rosettes. These progranules are present in white spiders only, and regularly distributed in the cytoplasm. The merging of several progranules of type I into a transient state (progranule type II) leads to the formation of granules (type III) characterized by their lack of fluorescence, their spherical sections and their osmophilic-electron-dense contents. They are found in yellow spiders and in the red stripes on the body sides. Their color varies from yellow to red. Thus, white spiders contain only type I granules, yellow tinted spiders contain type II and III granules and bright yellow spiders contain only type III granules. We present a synthetic view of the ontogeny of ommochrome granules. We discuss the physiology of color changing and the nature of the chemical compounds in the different types of granules. Extended studies on the ultrastructural modification and physiological processes associated with color change are required before any statement about the adaptiveness of the color change can be made.

Colloidal Aggregate Structure under Shear by USANS

NASA Astrophysics Data System (ADS)

Chatterjee, Tirtha; van Dyk, Antony K.; Ginzburg, Valeriy V.; Nakatani, Alan I.

2015-03-01

Paints are complex formulations of polymeric binders, inorganic pigments, dispersants, surfactants, colorants, rheology modifiers, and other additives. A commercially successful paint exhibits a desired viscosity profile over a wide shear rate range from 10-5 s-1 for settling to >104 s-1 for rolling, and spray applications. Understanding paint formulation structure is critical as it governs the paint viscosity profile. However, probing paint formulation structure under shear is a challenging task due to the formulation complexity containing structures with different hierarchical length scales and their alterations under the influence of an external flow field. In this work mesoscale structures of paint formulations under shear are investigated using Ultra Small-Angle Neutron Scattering (rheo-USANS). Contrast match conditions were utilized to independently probe the structure of latex binder particle aggregates and the TiO2 pigment particle aggregates. Rheo-USANS data revealed that the aggregates are fractal in nature and their self-similarity dimensions and correlations lengths depend on the chemistry of the binder particles, the type of rheology modifier present and the shear stress imposed upon the formulation. These results can be explained in the framework of diffusion and reaction limited transient aggregates structure evolution under simple shear.

In situ nondestructive imaging of functional pigments in Micro-Tom tomato fruits by multi spectral imaging based on Wiener estimation method

NASA Astrophysics Data System (ADS)

Nishidate, Izumi; Ooe, Shintaro; Todoroki, Shinsuke; Asamizu, Erika

2013-05-01

To evaluate the functional pigments in the tomato fruits nondestructively, we propose a method based on the multispectral diffuse reflectance images estimated by the Wiener estimation for a digital RGB image. Each pixel of the multispectral image is converted to the absorbance spectrum and then analyzed by the multiple regression analysis to visualize the contents of chlorophyll a, lycopene and β-carotene. The result confirms the feasibility of the method for in situ imaging of chlorophyll a, β-carotene and lycopene in the tomato fruits.

Comparison of pigment cell ultrastructure and organisation in the dermis of marble trout and brown trout, and first description of erythrophore ultrastructure in salmonids

PubMed Central

Djurdjevič, Ida; Kreft, Mateja Erdani; Sušnik Bajec, Simona

2015-01-01

Skin pigmentation in animals is an important trait with many functions. The present study focused on two closely related salmonid species, marble trout (Salmo marmoratus) and brown trout (S. trutta), which display an uncommon labyrinthine (marble-like) and spot skin pattern, respectively. To determine the role of chromatophore type in the different formation of skin pigment patterns in the two species, the distribution and ultrastructure of chromatophores was examined with light microscopy and transmission electron microscopy. The presence of three types of chromatophores in trout skin was confirmed: melanophores; xanthophores; and iridophores. In addition, using correlative microscopy, erythrophore ultrastructure in salmonids was described for the first time. Two types of erythrophores are distinguished, both located exclusively in the skin of brown trout: type 1 in black spot skin sections similar to xanthophores; and type 2 with a unique ultrastructure, located only in red spot skin sections. Morphologically, the difference between the light and dark pigmentation of trout skin depends primarily on the position and density of melanophores, in the dark region covering other chromatophores, and in the light region with the iridophores and xanthophores usually exposed. With larger amounts of melanophores, absence of xanthophores and presence of erythrophores type 1 and type L iridophores in the black spot compared with the light regions and the presence of erythrophores type 2 in the red spot, a higher level of pigment cell organisation in the skin of brown trout compared with that of marble trout was demonstrated. Even though the skin regions with chromatophores were well defined, not all the chromatophores were in direct contact, either homophilically or heterophilically, with each other. In addition to short-range interactions, an important role of the cellular environment and long-range interactions between chromatophores in promoting adult pigment pattern formation of trout are proposed. PMID:26467239

Comparison of pigment cell ultrastructure and organisation in the dermis of marble trout and brown trout, and first description of erythrophore ultrastructure in salmonids.

PubMed

Djurdjevič, Ida; Kreft, Mateja Erdani; Sušnik Bajec, Simona

2015-11-01

Skin pigmentation in animals is an important trait with many functions. The present study focused on two closely related salmonid species, marble trout (Salmo marmoratus) and brown trout (S. trutta), which display an uncommon labyrinthine (marble-like) and spot skin pattern, respectively. To determine the role of chromatophore type in the different formation of skin pigment patterns in the two species, the distribution and ultrastructure of chromatophores was examined with light microscopy and transmission electron microscopy. The presence of three types of chromatophores in trout skin was confirmed: melanophores; xanthophores; and iridophores. In addition, using correlative microscopy, erythrophore ultrastructure in salmonids was described for the first time. Two types of erythrophores are distinguished, both located exclusively in the skin of brown trout: type 1 in black spot skin sections similar to xanthophores; and type 2 with a unique ultrastructure, located only in red spot skin sections. Morphologically, the difference between the light and dark pigmentation of trout skin depends primarily on the position and density of melanophores, in the dark region covering other chromatophores, and in the light region with the iridophores and xanthophores usually exposed. With larger amounts of melanophores, absence of xanthophores and presence of erythrophores type 1 and type L iridophores in the black spot compared with the light regions and the presence of erythrophores type 2 in the red spot, a higher level of pigment cell organisation in the skin of brown trout compared with that of marble trout was demonstrated. Even though the skin regions with chromatophores were well defined, not all the chromatophores were in direct contact, either homophilically or heterophilically, with each other. In addition to short-range interactions, an important role of the cellular environment and long-range interactions between chromatophores in promoting adult pigment pattern formation of trout are proposed. © 2015 Anatomical Society.

Biomimetic light-harvesting funnels for re-directioning of diffuse light.

PubMed

Pieper, Alexander; Hohgardt, Manuel; Willich, Maximilian; Gacek, Daniel Alexander; Hafi, Nour; Pfennig, Dominik; Albrecht, Andreas; Walla, Peter Jomo

2018-02-14

Efficient sunlight harvesting and re-directioning onto small areas has great potential for more widespread use of precious high-performance photovoltaics but so far intrinsic solar concentrator loss mechanisms outweighed the benefits. Here we present an antenna concept allowing high light absorption without high reabsorption or escape-cone losses. An excess of randomly oriented pigments collects light from any direction and funnels the energy to individual acceptors all having identical orientations and emitting ~90% of photons into angles suitable for total internal reflection waveguiding to desired energy converters (funneling diffuse-light re-directioning, FunDiLight). This is achieved using distinct molecules that align efficiently within stretched polymers together with others staying randomly orientated. Emission quantum efficiencies can be >80% and single-foil reabsorption <0.5%. Efficient donor-pool energy funneling, dipole re-orientation, and ~1.5-2 nm nearest donor-acceptor transfer occurs within hundreds to ~20 ps. Single-molecule 3D-polarization experiments confirm nearly parallel emitters. Stacked pigment selection may allow coverage of the entire solar spectrum.

[Loquat canker: a new disease for Argentina].

PubMed

Alippi, A M; Alippi, H E

1990-01-01

A stem canker disease caused by Pseudomonas syringae pv. eriobotryae (Takimoto) Young, Dye y Wilkie on loquat (Eriobotrya Japonica [Thumb] Lindl) was recorded for the first time in Argentina. Symptoms of the disease appeared as dry stem cankers which in advanced stages surrounded the stems. Similar cankers were noticeable on leaves midribs. Seven bacterial strains were isolated from diseased loquats and their identification was based on disease symptoms, pathogenicity and cultural and biochemical characteristics. All strains were levan positive and gave a hypersensitive reaction on tobacco leaves. Neither arginine dehydrolase nor oxidase was detected in any of the strains which produced a diffusible green pigment on King B which fluoresced under UV light and a distinct diffusible brown pigment on King B, SPA and Tween 80 media within 5-7 days of incubation. Lipolysis of Tween 80 was also recorded. The symptoms observed in the field and obtained by experimental inoculations were similar to those induced by Pseudomonas syringae pv. eriobotryae in the original description of the disease.

Nanoscale Coloristic Pigments: Upper Limits on Releases from Pigmented Plastic during Environmental Aging, In Food Contact, and by Leaching.

PubMed

Neubauer, Nicole; Scifo, Lorette; Navratilova, Jana; Gondikas, Andreas; Mackevica, Aiga; Borschneck, Daniel; Chaurand, Perrine; Vidal, Vladimir; Rose, Jerome; von der Kammer, Frank; Wohlleben, Wendel

2017-10-17

The life cycle of nanoscale pigments in plastics may cause environmental or human exposure by various release scenarios. We investigated spontaneous and induced release with mechanical stress during/after simulated sunlight and rain degradation of polyethylene (PE) with organic and inorganic pigments. Additionally, primary leaching in food contact and secondary leaching from nanocomposite fragments with an increased surface into environmental media was examined. Standardized protocols/methods for release sampling, detection, and characterization of release rate and form were applied: Transformation of the bulk material was analyzed by Scanning Electron Microscopy (SEM), X-ray-tomography and Fourier-Transform Infrared spectroscopy (FTIR); releases were quantified by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), single-particle-ICP-MS (sp-ICP-MS), Transmission Electron Microscopy (TEM), Analytical Ultracentrifugation (AUC), and UV/Vis spectroscopy. In all scenarios, the detectable particulate releases were attributed primarily to contaminations from handling and machining of the plastics, and were not identified with the pigments, although the contamination of 4 mg/kg (Fe) was dwarfed by the intentional content of 5800 mg/kg (Fe as Fe 2 O 3 pigment). We observed modulations (which were at least partially preventable by UV stabilizers) when comparing as-produced and aged nanocomposites, but no significant increase of releases. Release of pigments was negligible within the experimental error for all investigated scenarios, with upper limits of 10 mg/m 2 or 1600 particles/mL. This is the first holistic confirmation that pigment nanomaterials remain strongly contained in a plastic that has low diffusion and high persistence such as the polyolefin High Density Polyethylene (HDPE).

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

PubMed

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

2009-07-01

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

Lamp system with conditioned water coolant and diffuse reflector of polytetrafluorethylene(PTFE)

DOEpatents

Zapata, Luis E.; Hackel, Lloyd

1999-01-01

A lamp system with a very soft high-intensity output is provided over a large area by water cooling a long-arc lamp inside a diffuse reflector of polytetrafluorethylene (PTFE) and titanium dioxide (TiO.sub.2) white pigment. The water is kept clean and pure by a one micron particulate filter and an activated charcoal/ultraviolet irradiation system that circulates and de-ionizes and biologically sterilizes the coolant water at all times, even when the long-arc lamp is off.

Diffusely Reflecting Paints Containing TFE

NASA Technical Reports Server (NTRS)

Shai, M. C.; Schutt, J. B.

1985-01-01

Highly reflective, diffused coatings developed by incorporating polytetrafluoroethylene (TFE) pigment with alcohol-soluble binders. Alcohol and binder mixed together in blender before adding TFE. TFE preferably outgassed in mechanical-pump vacuum for typical interval of 4 hours before adding to liquid. Like wetting agent, vacuum treatment helps to prevent clumping of TFE and eases dispersion throughout mixture. Mixture blended for 3 to 5 minutes before used. Coatings useful on reflectance-standard surfaces for calibrating radiometric instruments in both laboratory and field. Paints washable and usable as optical reference surfaces.

Effect of opacifiers and UV absorbers on pigmented maxillofacial silicone elastomer, part 2: mechanical properties after artificial aging.

PubMed

Nguyen, Caroline Tram; Chambers, Mark S; Powers, John M; Kiat-Amnuay, Sudarat

2013-06-01

There are reports of dissatisfaction with color instability and reduced lifetime of extraoral maxillofacial prostheses. Previous studies showed that UV mineral-based light-protecting agent (LP) improved color stability of MDX4-4210/Type A silicone elastomer. However, effects of this agent and opacifiers on mechanical properties of the elastomer are unknown. The purpose of this study was to evaluate the effect of 2 commonly used opacifiers and LP, a new opacifier, when combined with pigments on the mechanical properties of MDX4-4210/Type A silicone elastomer before and after artificial aging. Two commonly used opacifiers, titanium white dry pigment (TW) and silicone intrinsic white (SW) and LP were each combined with MDX4-4210/type A. Artists' oil pigment was then combined with the LP and TW groups, and silicone intrinsic pigments were combined with the SW group with 5 colors (no pigment=control, red, yellow, blue, or a combination of the 3 pigments). Ten dumbbell-shaped and 10 trouser-shaped specimens of each opacifier + pigment mixture, plus a control group with no opacifier and no pigment, were made for a total of 320 specimens. Half of the specimens (n=5) were aged in a chamber at 450 kJ/m(2). Specimens were tested for hardness (ASTM D2240), tensile strength (ASTM D412), tear strength (ASTM D624), and percentage elongation in a universal testing machine. A 3-way ANOVA and the Fisher PLSD test were performed (α=.05) for each mechanical property. After accelerated aging, values of Shore A hardness were the lowest for LP with all 5 pigments and the control, followed by SW and TW (P<.001). After accelerated aging, tear strength, tensile strength, and elongation decreased significantly (P<.001) for LP, whereas changes for SW and TW varied depending on the pigment. The mechanical properties of specimens with the light-protecting opacifier were adversely affected after being subjected to artificial aging. SW and TW preserved the mechanical properties of silicone in this study. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Effect of opacifiers and UV absorbers on pigmented maxillofacial silicone elastomer, part 1: color stability after artificial aging.

PubMed

Han, Ying; Powers, John M; Kiat-Amnuay, Sudarat

2013-06-01

Much dissatisfaction with the color instability and reduced lifetime of extraoral maxillofacial prostheses due to degradation has been reported. The purpose of this study was to compare the effect of a UV mineral-based light protecting agent (LP) on the color stability of pigmented maxillofacial silicone elastomer MDX-4210/Type A after artificial aging to 2 widely used opacifiers. Forty-five groups were established (n=225 total). Three different types of opacifiers (LP, titanium white dry pigment [TW], or silicone intrinsic white [SW]) were added to silicone MDX-4210/type A at 3 concentrations (5%, 10%, or 15%) and subsequently combined with each of 5 colors (no pigments [control], red, blue, yellow, or mixed pigments). Artists' oil pigment was used with LP and TW, while intrinsic silicone pigment was used to color SW. Before and after an energy exposure of 450 kJ/m(2), CIE L*a*b* values were measured with a spectrophotometer. The CIELAB 50:50% perceptibility (ΔE*=1.1) and acceptability threshold (ΔE*=3.0) were used to interpret color changes (ΔE*). Color differences after aging were subjected to 3-way ANOVA. Means were compared by the Fisher PLSD intervals at α=.05. The ΔE* values of all groups were below the acceptability threshold of ΔE*=3.0, except for the control group of SW at 10%, which showed the greatest color change (ΔE*=3.1). When mixed pigment groups were considered, at 5% concentration, LP showed the smallest color change, followed by SW and TW (P<.05); at 10%, no significant differences among the 3 opacifiers were noted (P>.05); at 15%, LP showed the smallest color change, followed by TW and SW (P<.05). All 3 opacifiers at all concentrations protected pigmented silicone MDX4-4210/Type A from color degradation. The LP group showed the smallest color changes. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Diffuse Reflectance Spectroscopy Versus Mexameter(®) MX18 Measurements of Melanin and Erythema in an African Population.

PubMed

Wright, Caradee Y; Karsten, Aletta E; Wilkes, Marcus; Singh, Ann; du Plessis, Johan; Albers, Patricia N; Karsten, Petrus A

2016-07-01

Melanin provides protection against excess exposure to solar ultraviolet radiation (UVR) and related adverse health effects. Diffuse reflectance spectroscopy (DRS) can be used to calculate cutaneous melanin and erythema, but this is complex and has been mostly used for light-to-medium pigmented skin. Handheld reflectance spectrophotometers, such as the Mexameter(®) MX18, can also be used. We compared DRS-calculated melanin and erythema values with Mexameter melanin and erythema index values to understand how these techniques/measurements correlate in an African population of predominantly deeply pigmented skin. Five hundred and three participants comprised 68.5% self-identified Black African, 9.9% Indian/Asian, 18.4% White and 2.9% Colored. The majority of Black African (45%), Indian/Asian (34%) and Colored (53%) participants self-identified their skin as being "brown." Measured melanin levels increased with darker self-reported skin color. DRS-calculated and Mexameter melanin values demonstrated a positive correlation (Spearman rho = 0.87, P < 0.001). The results from both instruments showed erythema values were strongly correlated with their own melanin values. This finding is considered spurious and may result from the complexity of separating brown and red pigment when using narrowband reflectance techniques. Further work is needed to understand melanin, erythema and color in Black skin given sun-related health risks in vulnerable groups in Africa. © 2016 The American Society of Photobiology.

Triple retinal infection with human immunodeficiency virus type 1, cytomegalovirus, and herpes simplex virus type 1. Light and electron microscopy, immunohistochemistry, and in situ hybridization.

PubMed

Rummelt, V; Rummelt, C; Jahn, G; Wenkel, H; Sinzger, C; Mayer, U M; Naumann, G O

1994-02-01

This report describes the histopathologic and virologic findings of the retina from a 55-year-old bisexual patient with the acquired immune deficiency syndrome (AIDS), who had concurrent human immunodeficiency virus type 1 (HIV-1), cytomegalovirus (CMV), and herpes simplex virus type 1 (HSV-1) retinitis, and was treated with ganciclovir. The eyes were obtained at autopsy and processed for light microscopy and transmission electron microscopy. Immunohistochemical stains for HSV-1, CMV, HIV-1, varicella zoster virus, and glial fibrillary acidic protein were carried out using the peroxidase-antiperoxidase and streptavidin-biotin-alkaline phosphatase techniques. For in situ hybridization, a radiolabeled CMV DNA probe (Eco-RI-Y fragment of strain AD 169) was used. Results of histopathologic examination showed a full-thickness necrotizing retinitis with cytomegalic and herpes viral intranuclear inclusions in cells of the neurosensory retina, retinal vascular endothelium, and the retinal pigment epithelium. Some areas of the retina were replaced by glial tissue. The choroid contained only a few chronic inflammatory cells. Immunoperoxidase studies disclosed CMV antigens diffusely distributed throughout all layers of the retina and the retinal pigment epithelium. Herpes simplex virus type 1 antigens were present in retinal cells and the retinal vascular endothelium. Human immunodeficiency virus type 1 antigens were found in mononuclear cells in all layers of the sensory retina. Dual infections with HIV-1 and CMV of individual multinucleated giant cells of glial origin were demonstrated immunohistochemically. Transmission electron microscopy showed herpes viral particles in the vascular endothelium of the retinal vessels and the choriocapillaris. Human immunodeficiency virus particles were identified in the endothelium of the choriocapillaris. The possibility of multiple viral infections of the retina, mimicking classic CMV retinitis, should be considered in the clinical and histologic differential diagnosis of necrotizing retinitis in patients with AIDS.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY SHOWS INNER CHOROIDAL ISCHEMIA IN ACUTE POSTERIOR MULTIFOCAL PLACOID PIGMENT EPITHELIOPATHY.

PubMed

Dolz-Marco, Rosa; Sarraf, David; Giovinazzo, Vincent; Freund, K Bailey

2017-01-01

To describe multimodal imaging findings of an evolving case of acute posterior multifocal placoid pigment epitheliopathy occurring in a young healthy male. Case report of a patient with acute posterior multifocal placoid pigment epitheliopathy including comprehensive systemic and ocular examinations. Ultra-widefield autofluorescence, fluorescein angiography, indocyanine green angiography, and serial optical coherence tomography angiography were performed. A 34-year-old male presented with acute vision loss in his left eye for 2 weeks. His best-corrected visual acuity was 20/20 in his right eye and 20/200 in his left eye. Dilated funduscopic examination revealed multiple creamy white deep retinal lesions showing macular involvement of the left eye with a diffuse area of pigmentary changes. The presence of multiple areas of hypoperfusion of the inner choroid were demonstrated with fluorescein and indocyanine green angiography. Serial optical coherence tomography angiography showed multiple evolving areas of decreased flow at the level of the inner choroid. Although the pathogenesis of acute posterior multifocal placoid pigment epitheliopathy remains unknown, there is growing evidence of a primary choroidal involvement with secondary damage to the overlying retinal pigment epithelium and the outer retinal layers. Optical coherence tomography angiography may provide valuable information for the diagnosis and follow-up of this condition avoiding invasive angiographic procedures.

Betacyanins pigments as photosensitizing agents for holographic recording medium

NASA Astrophysics Data System (ADS)

Toxqui-López, S.; Hernández-Hernández, E.; Santacruz-Vázquez, C.; Olivares-Pérez, A.; Santacruz-Vazquez, V.

2014-02-01

One of the natural most employed within the food industry are pigments of betalains by their solubility in water to give desired colorations in processed foods such as beverages, dairy, meat. However, this research shows that this type of pigments can be used as photosensitizing agents in the field of holographic recording materials.

Effects of ultraviolet radiation, visible light, and infrared radiation on erythema and pigmentation: a review.

PubMed

Sklar, Lindsay R; Almutawa, Fahad; Lim, Henry W; Hamzavi, Iltefat

2013-01-01

The effects of ultraviolet radiation, visible light, and infrared radiation on cutaneous erythema, immediate pigment darkening, persistent pigment darkening, and delayed tanning are affected by a variety of factors. Some of these factors include the depth of cutaneous penetration of the specific wavelength, the individual skin type, and the absorption spectra of the different chromophores in the skin. UVB is an effective spectrum to induce erythema, which is followed by delayed tanning. UVA induces immediate pigment darkening, persistent pigment darkening, and delayed tanning. At high doses, UVA (primarily UVA2) can also induce erythema in individuals with skin types I-II. Visible light has been shown to induce erythema and a tanning response in dark skin, but not in fair skinned individuals. Infrared radiation produces erythema, which is probably a thermal effect. In this article we reviewed the available literature on the effects of ultraviolet radiation, visible light, and infrared radiation on the skin in regards to erythema and pigmentation. Much remains to be learned on the cutaneous effects of visible light and infrared radiation.

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

The photophysics of monomeric bacteriochlorophylls c and d and their derivatives: properties of the triplet state and singlet oxygen photogeneration and quenching

NASA Technical Reports Server (NTRS)

Krasnovsky, A. A. Jr; Cheng, P.; Blankenship, R. E.; Moore, T. A.; Gust, D.

1993-01-01

Measurements of pigment triplet-triplet absorption, pigment phosphorescence and photosensitized singlet oxygen luminescence were carried out on solutions containing monomeric bacteriochlorophylls (Bchl) c and d, isolated from green photosynthetic bacteria, and their magnesium-free and farnesyl-free analogs. The energies of the pigment triplet states fell in the range 1.29-1.34 eV. The triplet lifetimes in aerobic solutions were 200-250 ns; they increased to 280 +/- 70 microseconds after nitrogen purging in liquid solutions and to 0.7-2.1 ms in a solid matrix at ambient or liquid nitrogen temperatures. Rate constants for quenching of the pigment triplet state by oxygen were (2.0-2.5) x 10(9) M-1 s-1, which is close to 1/9 of the rate constant for diffusion-controlled reactions. This quenching was accompanied by singlet oxygen formation. The quantum yields for the triplet state formation and singlet oxygen production were 55-75% in air-saturated solutions. Singlet oxygen quenching by ground-state pigment molecules was observed. Quenching was the most efficient for magnesium-containing pigments, kq = (0.31-1.2) x 10(9) M-1 s-1. It is caused mainly by a physical process of singlet oxygen (1O2) deactivation. Thus, Bchl c and d and their derivatives, as well as chlorophyll and Bchl a, combine a high efficiency of singlet oxygen production with the ability to protect photochemical and photobiological systems against damage by singlet oxygen.

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.

Reaction-diffusion pattern in shoot apical meristem of plants.

PubMed

Fujita, Hironori; Toyokura, Koichi; Okada, Kiyotaka; Kawaguchi, Masayoshi

2011-03-29

A fundamental question in developmental biology is how spatial patterns are self-organized from homogeneous structures. In 1952, Turing proposed the reaction-diffusion model in order to explain this issue. Experimental evidence of reaction-diffusion patterns in living organisms was first provided by the pigmentation pattern on the skin of fishes in 1995. However, whether or not this mechanism plays an essential role in developmental events of living organisms remains elusive. Here we show that a reaction-diffusion model can successfully explain the shoot apical meristem (SAM) development of plants. SAM of plants resides in the top of each shoot and consists of a central zone (CZ) and a surrounding peripheral zone (PZ). SAM contains stem cells and continuously produces new organs throughout the lifespan. Molecular genetic studies using Arabidopsis thaliana revealed that the formation and maintenance of the SAM are essentially regulated by the feedback interaction between WUSHCEL (WUS) and CLAVATA (CLV). We developed a mathematical model of the SAM based on a reaction-diffusion dynamics of the WUS-CLV interaction, incorporating cell division and the spatial restriction of the dynamics. Our model explains the various SAM patterns observed in plants, for example, homeostatic control of SAM size in the wild type, enlarged or fasciated SAM in clv mutants, and initiation of ectopic secondary meristems from an initial flattened SAM in wus mutant. In addition, the model is supported by comparing its prediction with the expression pattern of WUS in the wus mutant. Furthermore, the model can account for many experimental results including reorganization processes caused by the CZ ablation and by incision through the meristem center. We thus conclude that the reaction-diffusion dynamics is probably indispensable for the SAM development of plants.

Reaction-Diffusion Pattern in Shoot Apical Meristem of Plants

PubMed Central

Fujita, Hironori; Toyokura, Koichi; Okada, Kiyotaka; Kawaguchi, Masayoshi

2011-01-01

A fundamental question in developmental biology is how spatial patterns are self-organized from homogeneous structures. In 1952, Turing proposed the reaction-diffusion model in order to explain this issue. Experimental evidence of reaction-diffusion patterns in living organisms was first provided by the pigmentation pattern on the skin of fishes in 1995. However, whether or not this mechanism plays an essential role in developmental events of living organisms remains elusive. Here we show that a reaction-diffusion model can successfully explain the shoot apical meristem (SAM) development of plants. SAM of plants resides in the top of each shoot and consists of a central zone (CZ) and a surrounding peripheral zone (PZ). SAM contains stem cells and continuously produces new organs throughout the lifespan. Molecular genetic studies using Arabidopsis thaliana revealed that the formation and maintenance of the SAM are essentially regulated by the feedback interaction between WUSHCEL (WUS) and CLAVATA (CLV). We developed a mathematical model of the SAM based on a reaction-diffusion dynamics of the WUS-CLV interaction, incorporating cell division and the spatial restriction of the dynamics. Our model explains the various SAM patterns observed in plants, for example, homeostatic control of SAM size in the wild type, enlarged or fasciated SAM in clv mutants, and initiation of ectopic secondary meristems from an initial flattened SAM in wus mutant. In addition, the model is supported by comparing its prediction with the expression pattern of WUS in the wus mutant. Furthermore, the model can account for many experimental results including reorganization processes caused by the CZ ablation and by incision through the meristem center. We thus conclude that the reaction-diffusion dynamics is probably indispensable for the SAM development of plants. PMID:21479227

Three cases of pigmented cosmetic dermatitis-like eruptions associated with primary Sjögren's syndrome or anti-SSA antibody.

PubMed

Takeo, Naoko; Sakai, Takashi; Saito-Shono, Tomoko; Ishikawa, Kazushi; Hatano, Yutaka; Katagiri, Kazumoto; Takahashi, Yoshihiro; Kawano, Kenji; Kimoto, Kenichi; Kubota, Toshiaki; Eshima, Nobuoki; Kojima, Hiroto; Fujiwara, Sakuhei

2016-08-01

Pigmented cosmetic dermatitis-like (Riehl's melanosis-like) pigmentation was reported in three of 27 patients with primary Sjögren's syndrome. But case reports of such eruptions are rare. We describe three cases of such eruptions associated with primary Sjögren's syndrome or anti-SSA antibody and possible associations with specific types of human leukocyte antigen (HLA) and infiltrating lymphocytes. These middle-aged Japanese women had reticular facial pigmentation and histopathological examination revealed interface dermatitis, melanophages, and dense lymphocytic infiltration around hair follicles and sweat ducts. HLA typing revealed common antigenic equivalents or genetic typing of HLA-A2, DR52, DPA1(02:02) and DPB1(05:01). Immunohistochemical staining revealed major subsets of T cells to be CD8 and CD45RO. Some Foxp3- and few IL17-positive cells were found in strong contrast to the major CD4 subset of infiltrated T cells in annular erythema associated with Sjögren's syndrome. Apparently, our patients' pigmentation represented a specific etiology associated with primary Sjögren's syndrome or anti-SSA antibody. © 2016 Japanese Dermatological Association.

Acquired hemochromatosis with pronounced pigment deposition of the upper eyelids.

PubMed

Chacon, Anna H; Morrison, Brian; Hu, Shasa

2013-10-01

primary (hereditary) or secondary (acquired). The acquired type most commonly occurs after massive intake of iron supplements or blood transfusions and is also known as transfusional iron overload. In the past, hemochromatosis was usually recognized at an advanced stage by the classic triad of hyperpigmentation, diabetes mellitus ("bronze diabetes"), and hepatic cirrhosis. Cutaneous hyperpigmentation is present in 70 percent of patients due to two different mechanisms: (1) hemosiderin deposition resulting in diffuse, slate-gray darkening and (2) increased production of melanin in the epidermis. A 47-year-old woman who receives regular transfusions due to low iron and chronic, unresolving anemia and who subsequently developed pronounced hyperpigmentation of the upper eyelids is described. The presentation, diagnosis, pathogenesis, and treatment options of hyperpigmentation due to secondary hemochromatosis are discussed.

Visual tracing of diffusion and biodistribution for amphiphilic cationic nanoparticles using photoacoustic imaging after ex vivo intravitreal injections

PubMed Central

Xu, Xu; Xu, Zhaokang; Liu, Junyi; Zhang, Zhaoliang; Chen, Hao; Li, Xingyi; Shi, Shuai

2016-01-01

To visually trace the diffusion and biodistribution of amphiphilic cation micelles after vitreous injection, various triblock copolymers of monomethoxy poly(ethylene glycol)–poly(ε-caprolactone)–polyethylenimine were synthesized with different structures of hydrophilic and hydrophobic segments, followed by labeling with near-infrared fluorescent dye Cyanine5 or Cyanine7. The micellar size, polydispersity index, and surface charge were measured by dynamic light scattering. The diffusion was monitored using photoacoustic imaging in real time after intravitreal injections. Moreover, the labeled nanoparticle distribution in the posterior segment of the eye was imaged histologically by confocal microscopy. The results showed that the hydrophilic segment increased vitreous diffusion, while a positive charge on the particle surface hindered diffusion. In addition, the particles diffused through the retinal layers and were enriched in the retinal pigment epithelial layer. This work tried to study the diffusion rate via a simple method by using visible images, and then provided basic data for the development of intraocular drug carriers. PMID:27785015

Visual tracing of diffusion and biodistribution for amphiphilic cationic nanoparticles using photoacoustic imaging after ex vivo intravitreal injections.

PubMed

Xu, Xu; Xu, Zhaokang; Liu, Junyi; Zhang, Zhaoliang; Chen, Hao; Li, Xingyi; Shi, Shuai

To visually trace the diffusion and biodistribution of amphiphilic cation micelles after vitreous injection, various triblock copolymers of monomethoxy poly(ethylene glycol)-poly(ε-caprolactone)-polyethylenimine were synthesized with different structures of hydrophilic and hydrophobic segments, followed by labeling with near-infrared fluorescent dye Cyanine5 or Cyanine7. The micellar size, polydispersity index, and surface charge were measured by dynamic light scattering. The diffusion was monitored using photoacoustic imaging in real time after intravitreal injections. Moreover, the labeled nanoparticle distribution in the posterior segment of the eye was imaged histologically by confocal microscopy. The results showed that the hydrophilic segment increased vitreous diffusion, while a positive charge on the particle surface hindered diffusion. In addition, the particles diffused through the retinal layers and were enriched in the retinal pigment epithelial layer. This work tried to study the diffusion rate via a simple method by using visible images, and then provided basic data for the development of intraocular drug carriers.

Eye pigments in wild-type and eye-color mutant strains of the African malaria vector Anopheles gambiae.

PubMed

Beard, C B; Benedict, M Q; Primus, J P; Finnerty, V; Collins, F H

1995-01-01

Chromatographic analysis of pigments extracted from wild-type eyes of the mosquito Anopheles gambiae reveals the presence of the ommatin precursor 3-hydroxykynurenine, its transamination derivative xanthurenic acid, and a dark, red-brown pigment spot that probably is composed of two or more low mobility xanthommatins. No colored or fluorescent pteridines are evident. Mosquitoes homozygous for an autosomal recessive mutation at the red-eye (r) locus have a brick-red eye color in larvae, pupae, and young adults, in contrast to the almost black color of the wild eye. Mosquitoes homozygous for this mutant allele have levels of ommochrome precursors that are indistinguishable from the wild-type, but the low-mobility xanthommatin spot is ochre-brown in color rather than red-brown as in the wild-type. Mosquitoes with two different mutant alleles at the X-linked pink-eye locus (p, which confers a pink eye color, and pw, which confers a white eye phenotype in homozygotes or hemizygous males) have normal levels of ommochrome precursors but no detectable xanthommatins. Mosquitoes homozygous for both the r and p mutant alleles have apricot-colored eyes and show no detectable xanthommatins. Both the pink-eye and red-eye mutations appear to involve defects in the transport into or assembly of pigments in the membrane-bound pigment granules rather then defects in ommochrome synthesis.

Differences in antimicrobial susceptibility of pigmented and unpigmented colonial variants of Mycobacterium avium.

PubMed Central

Stormer, R S; Falkinham, J O

1989-01-01

Unpigmented colonial variants were isolated from pigmented Mycobacterium avium isolates recovered from patients with acquired immunodeficiency syndrome and the environment. The variants were interconvertible: the rate of transition from unpigmented to pigmented type was 4.0 x 10(-5) variants per cell per generation. The unpigmented variants were more tolerant to antibiotics, especially beta-lactams, and Cd2+ and Cu2+ salts than were their pigmented parents. Both pigmented and unpigmented variants of the strains produced beta-lactamase, although beta-lactamase did not appear to be a determinant of beta-lactam susceptibility. Pigmented variants grew more rapidly in a number of commonly used mycobacterial media, were more hydrophobic, and had higher carotenoid contents than their unpigmented segregants. PMID:2808669

The hyper-fluorescent transitional bands in ultra-late phase of indocyanine green angiography in chronic central serous chorioretinopathy.

PubMed

Hua, Rui; Yao, Kai; Xia, Fan; Li, Jun; Guo, Lei; Yang, Guoxing; Tao, Jun

2016-03-01

Chronic central serous chorioretinopathy (CSCR) is regarded as a type of severe diffuse retinal pigment epitheliopathy. There is an atrophic tract at level of retinal pigment epithelium (RPE) due to hyper-permeability of choroidal vessels, along with photoreceptor (PR) atrophy. Indocyanine green angiography (ICGA) is considered a gold standard for diagnosis. The purpose of this work is to investigate the hyper-fluorescent transitional bands (HFTB) between hypo-fluorescent and normal regions of the retina in the ultra-late phase of ICGA in CSCR. 26 chronic CSCR eyes and 12 relative normal eyes received spectral domain optical coherence tomography (SD-OCT), and ICGA at the 24th hour after indocyanine green (ICG) intravenous injection. In the ultra-late phase, images showed homogenous fluorescence in all normal eyes. On the contrary, geographical hypofluorescent lesions with atrophy of RPE was noted in 26 chronic CSCR eyes. Moreover, HFTB with intact RPE and disrupted PR was detected in 20 out of 26 chronic CSCR eyes (76.9%). The HFTB may indicate the early damage in chronic CSCR. Ultra-late ICGA can monitor not only metabolic status by endogenous melanin, but also membrane function in RPE by exogenous ICG molecule. © 2015 Wiley Periodicals, Inc.

Targeted mutagenesis in Atlantic salmon (Salmo salar L.) using the CRISPR/Cas9 system induces complete knockout individuals in the F0 generation.

PubMed

Edvardsen, Rolf B; Leininger, Sven; Kleppe, Lene; Skaftnesmo, Kai Ove; Wargelius, Anna

2014-01-01

Understanding the biological function behind key proteins is of great concern in Atlantic salmon, both due to a high commercial importance and an interesting life history. Until recently, functional studies in salmonids appeared to be difficult. However, the recent discovery of targeted mutagenesis using the CRISPR/Cas9 (clustered regularly interspaced palindromic repeats/CRISPR-associated) system enables performing functional studies in Atlantic salmon to a great extent. We used the CRISPR/Cas9 system to target two genes involved in pigmentation, tyrosinase (tyr) and solute carrier family 45, member 2 (slc45a2). Embryos were assayed for mutation rates at the 17 somite stage, where 40 and 22% of all injected embryos showed a high degree of mutation induction for slc45a2 and tyr, respectively. At hatching this mutation frequency was also visible for both targeted genes, displaying a graded phenotype ranging from complete lack of pigmentation to partial loss and normal pigmentation. CRISPRslc45a2/Cas9 injected embryos showing a complete lack of pigmentation or just a few spots of pigments also lacked wild type sequences when assaying more than 80 (slc45a2) sequence clones from whole embryos. This indicates that CRISPR/Cas9 can induce double-allelic knockout in the F0 generation. However, types and frequency of indels might affect the phenotype. Therefore, the variation of indels was assayed in the graded pigmentation phenotypes produced by CRISPR/Cas9-slc45a2. The results show a tendency for fewer types of indels formed in juveniles completely lacking pigmentation compared to juveniles displaying partial pigmentation. Another interesting observation was a high degree of the same indel type in different juveniles. This study shows for the first time successful use of the CRISPR/Cas9 technology in a marine cold water species. Targeted double-allelic mutations were obtained and, though the level of mosaicism has to be considered, we demonstrate that F0 fish can be used for functional studies in Atlantic salmon.

A model of the photosynthetically available and usable irradiance in the sea

NASA Technical Reports Server (NTRS)

Collins, Donald J.; Davis, Curtiss O.; Booth, C. Rockwell; Kiefer, Dale A.; Stallings, Casson

1988-01-01

A theoretical model describing the depth dependence of the solar irradiance available to phytoplankton for photosynthesis is developed for waters classified as Case I by Jerlov (1976). The techniques used to account for the effects of incident solar irradiance, pigment concentration, and the spectral diffuse attentuation coefficient are described; an expression for the photosynthetically usable irradiance is derived; and particular attention is given to the specific diffuse absorption coefficient for chlorophyll (Morel, 1978). The relationships among the primary model parameters are shown in graphs.

Biochemical regulation of pigment motility in vertebrate chromatophores: a review of physiological color change mechanisms

PubMed Central

McCartney, Kristen L.

2016-01-01

Abstract The fundamental unit of rapid, physiological color change in vertebrates is the dermal chromatophore unit. This unit, comprised of cellular associations between different chromatophore types, is relatively conserved across the fish, amphibian, and reptilian species capable of physiological color change and numerous attempts have been made to understand the nature of the four major chromatophore types (melanophores, erythrophores, xanthophores, and iridophores) and their biochemical regulation. In this review, we attempt to describe the current state of knowledge regarding what classifies a pigment cell as a dynamic chromatophore, the unique characteristics of each chromatophore type, and how different hormones, neurotransmitters, or other signals direct pigment reorganization in a variety of vertebrate taxa. PMID:29491911

Bioluminescent signals spatially amplified by wavelength-specific diffusion through the shell of a marine snail.

PubMed

Deheyn, Dimitri D; Wilson, Nerida G

2011-07-22

Some living organisms produce visible light (bioluminescence) for intra- or interspecific visual communication. Here, we describe a remarkable bioluminescent adaptation in the marine snail Hinea brasiliana. This species produces a luminous display in response to mechanical stimulation caused by encounters with other motile organisms. The light is produced from discrete areas on the snail's body beneath the snail's shell, and must thus overcome this structural barrier to be viewed by an external receiver. The diffusion and transmission efficiency of the shell is greater than a commercial diffuser reference material. Most strikingly, the shell, although opaque and pigmented, selectively diffuses the blue-green wavelength of the species bioluminescence. This diffusion generates a luminous display that is enlarged relative to the original light source. This unusual shell thus allows spatially amplified outward transmission of light communication signals from the snail, while allowing the animal to remain safely inside its hard protective shell.

The role of natural and UV-induced skin pigmentation on low-fluence IPL-induced side effects: a randomized controlled trial.

PubMed

Thaysen-Petersen, Daniel; Lin, Jennifer Y; Nash, Jf; Beerwerth, Frank; Wulf, Hans C; Philipsen, Peter A; Haedersdal, Merete

2014-02-01

The risk of adverse skin effects following light-based hair removal is greater in pigmented skin based on the theory of selective photothermolysis. Thus sunlight-induced pigment i.e., facultative pigmentation, increases the risk of adverse skin effects, perhaps disproportionately. The aim of this study was to evaluate the influence of constitutive and facultative skin pigmentation on low-fluence intense pulsed light (IPL)-induced adverse skin effects. Twenty-one subjects with Fitzpatrick skin type II-IV were enrolled. Two buttock blocks were randomized to receive 0 or 8 solar simulated ultraviolet radiation (UVR) exposures of consecutively increasing Standard Erythema Doses (2-4 SED). Each block was subdivided into four sites, randomized to receive IPL of 0, 7, 8, or 10 J/cm(2) , once a week for 3 weeks. Biopsies were taken 16-24 hours after the first IPL exposure and subjects were seen 1 and 4 weeks after the last IPL exposure. Outcome measures were: (i) skin reactions, (ii) pain, (iii) mRNA expression of pigment-markers microphthalmia-associated transcription factor (MITF) and pro-opiomelanocortin (POMC), and (iv) clinical appearance of biopsy wounds. Skin pigmentation increased after UVR (baseline median 13.8%, after UVR 28.1%, P = 0.0001) in all skin types. Subjects reported low pain intensities (median 1.5, scale 0-10) and experienced transient erythema immediately after IPL exposure. No persistent erythema, blisters, crusting, textual, or pigment changes were observed. The risk of erythema and pain intensities increased with IPL dose and skin pigmentation (P < 0.03). There was no difference in pain or skin reactions in skin with similar degree of natural and facultative pigmentation (P ≥ 0.104). Expression of cellular pigment-markers was not influenced by IPL exposure, neither in constitutive nor in facultative pigmented skin. Clinical appearance of biopsy wounds was unaffected by IPL exposure. The prevalence and intensity of low-fluence IPL-induced adverse skin effects depended on IPL dose and skin pigmentation regardless of the origin, i.e., constitutive versus UV induced. © 2013 Wiley Periodicals, Inc.

Pterin pigments amplify iridescent ultraviolet signal in males of the orange sulphur butterfly, Colias eurytheme

PubMed Central

Rutowski, R.L; Macedonia, J.M; Morehouse, N; Taylor-Taft, L

2005-01-01

Animal colouration is typically the product of nanostructures that reflect or scatter light and pigments that absorb it. The interplay between these colour-producing mechanisms may influence the efficacy and potential information content of colour signals, but this notion has received little empirical attention. Wing scales in the male orange sulphur butterfly (Colias eurytheme) possess ridges with lamellae that produce a brilliant iridescent ultraviolet (UV) reflectance via thin-film interference. Curiously, these same scales contain pterin pigments that strongly absorb wavelengths below 550 nm. Given that male UV reflectance functions as a sexual signal in C. eurytheme, it is paradoxical that pigments in the wing scales are highly UV absorbing. We present spectrophotometric analyses of the wings before and after pterin removal that show that pterins both depress the amplitude of UV iridescence and suppress a diffuse UV reflectance that emanates from the scales. This latter effect enhances the directionality and spectral purity of the iridescence, and increases the signal's chromaticity and potential signal content. Our findings also suggest that pterins amplify the contrast between iridescent UV reflectance and scale background colour as a male's wings move during flight. PMID:16191648

Pterin pigments amplify iridescent ultraviolet signal in males of the orange sulphur butterfly, Colias eurytheme.

PubMed

Rutowski, R L; Macedonia, J M; Morehouse, N; Taylor-Taft, L

2005-11-07

Animal colouration is typically the product of nanostructures that reflect or scatter light and pigments that absorb it. The interplay between these colour-producing mechanisms may influence the efficacy and potential information content of colour signals, but this notion has received little empirical attention. Wing scales in the male orange sulphur butterfly (Colias eurytheme) possess ridges with lamellae that produce a brilliant iridescent ultraviolet (UV) reflectance via thin-film interference. Curiously, these same scales contain pterin pigments that strongly absorb wavelengths below 550 nm. Given that male UV reflectance functions as a sexual signal in C. eurytheme, it is paradoxical that pigments in the wing scales are highly UV absorbing. We present spectrophotometric analyses of the wings before and after pterin removal that show that pterins both depress the amplitude of UV iridescence and suppress a diffuse UV reflectance that emanates from the scales. This latter effect enhances the directionality and spectral purity of the iridescence, and increases the signal's chromaticity and potential signal content. Our findings also suggest that pterins amplify the contrast between iridescent UV reflectance and scale background colour as a male's wings move during flight.

Quantitative skin color measurements in acanthosis nigricans patients: colorimetry and diffuse reflectance spectroscopy.

PubMed

Pattamadilok, Bensachee; Devpura, Suneetha; Syed, Zain U; Agbai, Oma N; Vemulapalli, Pranita; Henderson, Marsha; Rehse, Steven J; Mahmoud, Bassel H; Lim, Henry W; Naik, Ratna; Hamzavi, Iltefat H

2012-08-01

Tristimulus colorimetry and diffuse reflectance spectroscopy (DRS) are white-light skin reflectance techniques used to measure the intensity of skin pigmentation. The tristimulus colorimeter is an instrument that measures a perceived color and the DRS instrument measures biological chromophores of the skin, including oxy- and deoxyhemoglobin, melanin and scattering. Data gathered from these tools can be used to understand morphological changes induced in skin chromophores due to conditions of the skin or their treatments. The purpose of this study was to evaluate the use of these two instruments in color measurements of acanthosis nigricans (AN) lesions. Eight patients with hyperinsulinemia and clinically diagnosable AN were seen monthly. Skin pigmentation was measured at three sites: the inner forearm, the medial aspect of the posterior neck, and anterior neck unaffected by AN. Of the three, measured tristimulus L*a*b* color parameters, the luminosity parameter L* was found to most reliably distinguish lesion from normally pigmented skin. The DRS instrument was able to characterize a lesion on the basis of the calculated melanin concentration, though melanin is a weak indicator of skin change and not a reliable measure to be used independently. Calculated oxyhemoglobin and deoxyhemoglobin concentrations were not found to be reliable indicators of AN. Tristimulus colorimetry may provide reliable methods for respectively quantifying and characterizing the objective color change in AN, while DRS may be useful in characterizing changes in skin melanin content associated with this skin condition. © 2012 John Wiley & Sons A/S.

Reflectance spectroscopy of pigmented cutaneous benign and malignant lesions

NASA Astrophysics Data System (ADS)

Borisova, E.; Jeliazkova, Al.; Pavlova, E.; Troyanova, P.; Kundurdjiev, T.; Pavlova, P.; Avramov, L.

2014-10-01

For the DRS measurements of skin benign, dysplastic and malignant lesions in vivo we applied halogen lamp (LS-1, OceanOptics Inc, Dunedin, Fl, USA) as a continuous light source in the region of 400-900 nm, optical probe (6+1 fibers) for the delivery of illumination and diffuse reflected light from the skin investigated and microspectrometer USB4000 (OceanOptics Inc., Dunedin, Fl, USA) for a storage and display of the spectra detected. As a diffuse reflectance standard Spectralon® plate was used to calibrate the spectrometer. The reflectance spectra obtained from normal skin in identical anatomic sites of different patients have similar spectral shape features, slightly differ by the reflectance intensity at different wavelengths, depending on the particular patient' skin phototype. One could find diagnostically important spectral features, related to specific intensity changes for a given wavelength due to specific pigments appearance, slope changes by value and sign for the reflectance spectra curves in a specific spectral range, disappearance or manifestation of minima, related to hemoglobin absorption at 410-420 nm, 543, 575 nm. Based on the observed peculiarities multispectral analysis of the reflectance spectra of the different lesions was used and diagnostically specific features are found. Discrimination using the DRS data obtained between benign compound and dermal nevi (45 cases), dysplastic nevi (17 cases) and pigmented malignant melanoma (41 cases) lesions is achieved with a diagnostic accuracy of 96 % for the benign nevi vs. MM, and 90 % for the dysplastic nevi vs. MM.

Depigmented skin and phantom color measurements for realistic prostheses.

PubMed

Tanner, Paul; Leachman, Sancy; Boucher, Kenneth; Ozçelik, Tunçer Burak

2014-02-01

The purpose of this study was to test the hypothesis that regardless of human skin phototype, areas of depigmented skin, as seen in vitiligo, are optically indistinguishable among skin phototypes. The average of the depigmented skin measurements can be used to develop the base color of realistic prostheses. Data was analyzed from 20 of 32 recruited vitiligo study participants. Diffuse reflectance spectroscopy measurements were made from depigmented skin and adjacent pigmented skin, then compared with 66 pigmented polydimethylsiloxane phantoms to determine pigment concentrations in turbid media for making realistic facial prostheses. The Area Under spectral intensity Curve (AUC) was calculated for average spectroscopy measurements of pigmented sites in relation to skin phototype (P = 0.0505) and depigmented skin in relation to skin phototype (P = 0.59). No significant relationship exists between skin phototypes and depigmented skin spectroscopy measurements. The average of the depigmented skin measurements (AUC 19,129) was the closest match to phantom 6.4 (AUC 19,162). Areas of depigmented skin are visibly indistinguishable per skin phototype, yet spectrometry shows that depigmented skin measurements varied and were unrelated to skin phototype. Possible sources of optical variation of depigmented skin include age, body site, blood flow, quantity/quality of collagen, and other chromophores. The average of all depigmented skin measurements can be used to derive the pigment composition and concentration for realistic facial prostheses. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

PubMed Central

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

2014-01-01

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

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

USGS Publications Warehouse

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

2014-01-01

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

Objective assessment of psoriasis erythema for PASI scoring.

PubMed

Ahmad Fadzil, M H; Ihtatho, Dani; Mohd Affandi, Azura; Hussein, S H

2009-01-01

Skin colour is vital information in dermatological diagnosis as it reflects the pathological condition beneath the skin. It is commonly used to indicate the extent of diseases such as psoriasis, which is indicated by the appearance of red plaques. Although there is no cure for psoriasis, there are many treatment modalities to help control the disease. To evaluate treatment efficacy, the current gold standard method, PASI (Psoriasis Area and Severity Index), is used to determine severity of psoriasis lesion. Erythema (redness) is one parameter in PASI and this condition is assessed visually, thus leading to subjective and inconsistent results. Current methods or instruments that assess erythema have limitations, such as being able to measure erythema well for low pigmented skin (fair skin) but not for highly pigmented skin (dark skin) or vice versa. In this work, we proposed an objective assessment of psoriasis erythema for PASI scoring for different (low to highly pigmented) skin types. The colour of psoriasis lesions are initially obtained by using a chromameter giving the values L*, a*, and b* of CIELAB colour space. The L* value is used to classify skin into three categories: low, medium and highly pigmented skin. The lightness difference (DeltaL*), hue difference (Deltah(ab)), chroma (DeltaC*(ab)) between lesions and the surrounding normal skin are calculated and analysed. It is found that the erythema score of a lesion can be distinguished by their Deltah(ab) value within a particular skin type group. References of lesion with different scores are obtained from the selected lesions by two dermatologists. Results based on 38 lesions from 22 patients with various level of skin pigmentation show that PASI erythema score for different skin types i.e. low (fair skin) to highly pigmented (dark skin) skin types can be determined objectively and consistent with dermatology scoring.

Spectral transmission and short-wave absorbing pigments in the fish lens--I. Phylogenetic distribution and identity.

PubMed

Thorpe, A; Douglas, R H; Truscott, R J

1993-02-01

Fish lens transmission was found to vary depending on the type and concentration of short-wave absorbing compounds present within the lens. Pigments extracted from lenses of ten species were identified as mycosporine-like amino acids (mainly palythine, palythene and asterina-330, lambda maxs around 320-360 nm) which are also thought to be present in the majority of the 120 species examined here. A novel mycosporine-like pigment with lambda max 385 nm was isolated from the lens of the flying fish, Exocoetus obtusirostris, while lenses of several closely related tropical freshwater species were found to have high concentrations of the tryptophan catabolite 3-hydroxykynurenine (lambda max 370 nm). The type of lens pigment a species possesses and its concentration depends upon both the animal's phylogenetic group and its "optical niche".

Technological study of ancient ceramics produced in Casteldurante (central Italy) during the Renaissance

NASA Astrophysics Data System (ADS)

Padeletti, G.; Fermo, P.; Gilardoni, S.; Galli, A.

In order to recover the ancient tradition concerning the materials used for the decoration, majolica shards produced during the Renaissance period in Casteldurante, a famous centre for ceramic production in Italy (Marche), have been examined. In the present study, pigments used for the decorations have been investigated by means of inductively coupled plasma optical emission spectrometry (ICP-OES), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDX) and diffuse-reflectance UV-Vis spectroscopy. Ochre, lead antimonate yellow, copper-based pigment and smalt have been used as colourants to obtain respectively yellow-orange, yellow, green and blue decorations in accordance with what is reported by the ancient recipes.

Phosphorylation-independent Suppression of Light-activated Visual Pigment by Arrestin in Carp Rods and Cones*

PubMed Central

Tomizuka, Junko; Tachibanaki, Shuji; Kawamura, Satoru

2015-01-01

Visual pigment in photoreceptors is activated by light. Activated visual pigment (R*) is believed to be inactivated by phosphorylation of R* with subsequent binding of arrestin. There are two types of photoreceptors, rods and cones, in the vertebrate retina, and they express different subtypes of arrestin, rod and cone type. To understand the difference in the function between rod- and cone-type arrestin, we first identified the subtype of arrestins expressed in rods and cones in carp retina. We found that two rod-type arrestins, rArr1 and rArr2, are co-expressed in a rod and that a cone-type arrestin, cArr1, is expressed in blue- and UV-sensitive cones; the other cone-type arrestin, cArr2, is expressed in red- and green-sensitive cones. We quantified each arrestin subtype and estimated its concentration in the outer segment of a rod or a cone in the dark; they were ∼0.25 mm (rArr1 plus rArr2) in a rod and 0.6–0.8 mm (cArr1 or cArr2) in a cone. The effect of each arrestin was examined. In contrast to previous studies, both rod and cone arrestins suppressed the activation of transducin in the absence of visual pigment phosphorylation, and all of the arrestins examined (rArr1, rArr2, and cArr2) bound transiently to most probably nonphosphorylated R*. One rod arrestin, rArr2, bound firmly to phosphorylated pigment, and the other two, rArr1 and cArr2, once bound to phosphorylated R* but dissociated from it during incubation. Our results suggested a novel mechanism of arrestin effect on the suppression of the R* activity in both rods and cones. PMID:25713141

Multiple Roles of Photosynthetic and Sunscreen Pigments in Cyanobacteria Focusing on the Oxidative Stress

PubMed Central

Wada, Naoki; Sakamoto, Toshio; Matsugo, Seiichi

2013-01-01

Cyanobacteria have two types of sunscreen pigments, scytonemin and mycosporine-like amino acids (MAAs). These secondary metabolites are thought to play multiple roles against several environmental stresses such as UV radiation and desiccation. Not only the large molar absorption coefficients of these sunscreen pigments, but also their antioxidative properties may be necessary for the protection of biological molecules against the oxidative damages induced by UV radiation. The antioxidant activity and vitrification property of these pigments are thought to be requisite for the desiccation and rehydration processes in anhydrobiotes. In this review, the multiple roles of photosynthetic pigments and sunscreen pigments on stress resistance, especially from the viewpoint of their structures, biosynthetic pathway, and in vitro studies of their antioxidant activity, will be discussed. PMID:24958001

Diversity and evolution of phycobilisomes in marine Synechococcus spp.: a comparative genomics study.

PubMed

Six, Christophe; Thomas, Jean-Claude; Garczarek, Laurence; Ostrowski, Martin; Dufresne, Alexis; Blot, Nicolas; Scanlan, David J; Partensky, Frédéric

2007-01-01

Marine Synechococcus owe their specific vivid color (ranging from blue-green to orange) to their large extrinsic antenna complexes called phycobilisomes, comprising a central allophycocyanin core and rods of variable phycobiliprotein composition. Three major pigment types can be defined depending on the major phycobiliprotein found in the rods (phycocyanin, phycoerythrin I or phycoerythrin II). Among strains containing both phycoerythrins I and II, four subtypes can be distinguished based on the ratio of the two chromophores bound to these phycobiliproteins. Genomes of eleven marine Synechococcus strains recently became available with one to four strains per pigment type or subtype, allowing an unprecedented comparative genomics study of genes involved in phycobilisome metabolism. By carefully comparing the Synechococcus genomes, we have retrieved candidate genes potentially required for the synthesis of phycobiliproteins in each pigment type. This includes linker polypeptides, phycobilin lyases and a number of novel genes of uncharacterized function. Interestingly, strains belonging to a given pigment type have similar phycobilisome gene complements and organization, independent of the core genome phylogeny (as assessed using concatenated ribosomal proteins). While phylogenetic trees based on concatenated allophycocyanin protein sequences are congruent with the latter, those based on phycocyanin and phycoerythrin notably differ and match the Synechococcus pigment types. We conclude that the phycobilisome core has likely evolved together with the core genome, while rods must have evolved independently, possibly by lateral transfer of phycobilisome rod genes or gene clusters between Synechococcus strains, either via viruses or by natural transformation, allowing rapid adaptation to a variety of light niches.

Clinical analysis and classification of dark eye circle.

PubMed

Huang, Yau-Li; Chang, Shyue-Luen; Ma, Lih; Lee, Mei-Ching; Hu, Sindy

2014-02-01

Dark eye circle (DEC) is a common problem that usually lacks detailed classification in the etiology and structural variations. A newly-developed DEC Assessment Score using Wood's lamp and ultrasonogram will provide a more precise evaluation of DEC for improving treatment results. Sixty-five cases, including eight males and 57 females with a mean age of 38.9 years, were enrolled. DEC were classified into pigmented (brown), vascular (blue to purple), structural, and mixed type by Wood's lamp and ultrasonogram. A scoring system with nine parameters, including brown hue, pigmented lesions, blue/pink/purple hue, periorbital puffiness, shadow hue, infraorbital palpebral bags, infraorbital grooves, blepharoptosis, and skin type, was used for clinical evaluation. Pigmented, vascular, structural, and mixed types of DEC represented 5%, 14%, 3%, and 78%, respectively. Thirty-three cases with periorbital puffiness were found to have higher "pre-septal thickness" than those of 20 controlled cases (P = 0.032). Fourteen patients with infraorbital palpebral bags were proved to have protruded retroseptal fat pads by ultrasonography. Pigmentation and vascular and structural components may play important roles in DEC. Detailed classification of DEC types will access physicians in the decision of appropriate therapeutic modalities. © 2013 The International Society of Dermatology.

Ceramic tiles with black pigment made from stainless steel plant dust: Physical properties and long-term leaching behavior of heavy metals.

PubMed

Zhu, Renbo; Ma, Guojun; Cai, Yongsheng; Chen, Yuxiang; Yang, Tong; Duan, Boyu; Xue, Zhengliang

2016-04-01

Stainless steel plant dust is a hazardous by-product of the stainless steelmaking industry. It contains large amounts of Fe, Cr, and Ni, and can be potentially recycled as a raw material of inorganic black pigment in the ceramic industry to reduce environmental contamination and produce value-added products. In this paper, ceramic tiles prepared with black pigment through recycling of stainless steel plant dust were characterized in terms of physical properties, such as bulk density, water absorption, apparent porosity, and volume shrinkage ratio, as well as the long-term leaching behavior of heavy metals (Cr, Ni, Pb, Cd, and Zn). The results show that good physical properties of ceramic tiles can be obtained with 8% pigments addition, sample preparation pressure of 25 MPa, and sintering at 1200 ºC for 30 min. The major controlling leaching mechanism for Cr and Pb from the ceramic tiles is initial surface wash-off, while the leaching behavior of Cd, Ni, and Zn from the stabilized product is mainly controlled by matrix diffusion. The reutilization process is safe and effective to immobilize the heavy metals in the stainless steel plant dust. Stainless steel plant dust is considered as a hazardous material, and it can be potentially recycled for black pigment preparation in the ceramic industry. This paper provides the characteristics of the ceramic tiles with black pigment through recycling stainless steel plant dust, and the long-term leaching behavior and controlling leaching mechanisms of heavy metals from the ceramic tile. The effectiveness of the treatment process is also evaluated.

A comparison of temperature profile depending on skin types for laser hair removal therapy.

PubMed

Kim, Tae-Hoon; Lee, Gwi-Won; Youn, Jong-In

2014-11-01

Although numerous lasers with different wavelengths are available for laser hair removal, their use in individuals with dark-pigmented skin remains a challenge. The present study aims to develop a numerical heat diffusion model considering skin types over various wavelengths. This numerical mode uses Pennes approximation to represent heat from metabolism, blood perfusion and an external heating source. The heat diffusion model is experimentally validated by using agar-based skin tissue phantoms. Diode lasers with four different wavelengths were used with two antithetical skin models. The pulse width and beam spot size were set to 200 ms and 1 cm(2), respectively. Temperature distribution along the hair structure and skin tissue was examined to determine both thermal confinement and heat transfer to the hair follicle. Experimental results are well matched with the numerical results. The results show that for the light skin model, thermal confinement is well achieved over various wavelengths, and treatment efficacy is expected to be better at a shorter wavelength. Otherwise, for the dark skin model, thermal confinement is poorly achieved as the wavelength decreases (<808 nm) and the temperature gap between the hair tip and the hair root is significantly large compared with the light skin model, which may lead to adverse effects. We believe that the developed numerical model will help to establish optimal laser parameters for different individuals during laser hair removal.

Orange-Pigmented Sputum as a Manifestation of Smoke Grenade Inhalation Injury.

PubMed

Chatzivasiloglou, Fotini; Katsenos, Stamatis; Psara, Anthoula; Tsintiris, Konstantinos

2016-01-01

A 34-year-old man presented with scanty hemoptysis, orange-colored expectoration, and mild dyspnea. He was in an enclosed building taking part in a military training exercise inhaling an orange-colored smoke from a smoke grenade ignition. His symptoms developed immediately after the initial exposure but he sought medical assistance 20 hours later because of their persistence. Fiberoptic bronchoscopy was performed revealing diffuse inflammatory tracheobronchial tree with streaky orange-pigmented secretions in the trachea and both main-stem bronchi. Acute tracheobronchitis was diagnosed and the patient was treated with nebulized bronchodilators and intravenous corticosteroids showing complete recovery. To our knowledge, this is the first well-documented report of inhalation injury induced by a smoke bomb explosion including potassium chlorate oxidizer and Sudan I and presenting with orange-pigmented sputum production. Smoke inhalation injury is associated with significant morbidity and mortality. The heterogeneity of the smoke and the large variety of the resulting symptoms may be the reason why a definition, specific diagnostic criteria, and therapeutic guidelines are still lacking.

Ultrastructural and biochemical analysis of epidermal xanthophores and dermal chromatophores of the teleost Sparus aurata.

PubMed

Ferrer, C; Solano, F; Zuasti, A

1999-04-01

We have studied the pigmentary system of the teleost Sparus aurata skin by electron microscopy and chromatographic analysis. Under electron microscopy, we found the dermis to contain the three major types of recognized chromatophores: melanophores, xanthophores and iridophores. Melanophores were more abundant in the dorsal region, whereas the iridophores were more abundant in the ventral region. The most important discovery was that of epidermal xanthophores. Epidermal xanthophores were the only chromatophores in the epidermis, something only found in S aurata and in a teleost species living in the Antartic sea. In contrast, the biochemical analysis did not establish any special characteristics: we found pteridine and flavin pigments located mostly in the pigmented dorsal region. Riboflavin and pterin were two of the most abundant coloured pigment types, but other colourless pigments such as xanthopterin and isoxanthopterin were also detected.

Development of Low Fouling and High Fouling-release Zwitterionic Marine Coatings

DTIC Science & Technology

2016-01-04

amount, pigment , crosslinker type and catalyst amount. The details are shown below, 1. PDMS coating with zwitterionic copolymer incorporated. PDMS...onto aluminum panels. The coating can be cured within 3.5 hours. 2. PDMS coating with pigment incorporated. Various amount of the pigment cadmium...stirred vigorously until all the solid were dispersed uniformly. The obtained viscous liquid was then mixed with 3 g PDMS crosslinker, and applied onto

Spontaneous Cholelithiasis in a Squirrel Monkey (Saimiri sciureus)

PubMed Central

Lieberman, Mia T.; Wachtman, Lynn M.; Marini, Robert P.; Bakthavatchalu, Vasu; Fox, James G.

2016-01-01

A mature female squirrel monkey was noted during routine semiannual examinations to have moderate progressive weight loss. Serum chemistry panels revealed marked increases in hepatic enzyme, bilirubin, and bile salt concentrations and hypoalbuminemia. Abdominal ultrasonography revealed echogenic, shadowing debris in the gallbladder, consistent with cholelithiasis. At necropsy, marked thickening and distension of the gallbladder, cystic duct, and common bile duct was noted, and more than 50 irregularly shaped, black gallstones were removed from the biliary tract. Gallbladder tissue, bile, and gallstones cultured positive for Escherichia coli and Proteus spp., suggesting a brown-pigment gallstone type secondary to a bacterial nidus. Histopathology revealed severe chronic–active diffuse cholecystitis and severe chronic-active hepatic degeneration and necrosis with severe cholestasis. To our knowledge, this report is the first description of spontaneous choleilthiasis in a squirrel monkey. PMID:26884412

Acquired Hemochromatosis with Pronounced Pigment Deposition of the Upper Eyelids

PubMed Central

Morrison, Brian; Hu, Shasa

2013-01-01

Hemochromatosis may be classified into two groups: primary (hereditary) or secondary (acquired). The acquired type most commonly occurs after massive intake of iron supplements or blood transfusions and is also known as transfusional iron overload. In the past, hemochromatosis was usually recognized at an advanced stage by the classic triad of hyperpigmentation, diabetes mellitus (“bronze diabetes”), and hepatic cirrhosis. Cutaneous hyperpigmentation is present in 70 percent of patients due to two different mechanisms: (1) hemosiderin deposition resulting in diffuse, slate-gray darkening and (2) increased production of melanin in the epidermis. A 47-year-old woman who receives regular transfusions due to low iron and chronic, unresolving anemia and who subsequently developed pronounced hyperpigmentation of the upper eyelids is described. The presentation, diagnosis, pathogenesis, and treatment options of hyperpigmentation due to secondary hemochromatosis are discussed. PMID:24155994

Retinal Pigment Epithelial Cells are a Potential Reservoir for Ebola Virus in the Human Eye

PubMed Central

Smith, Justine R.; Todd, Shawn; Ashander, Liam M.; Charitou, Theodosia; Ma, Yuefang; Yeh, Steven; Crozier, Ian; Michael, Michael Z.; Appukuttan, Binoy; Williams, Keryn A.; Lynn, David J.; Marsh, Glenn A.

2017-01-01

Purpose Success of Ebola virus (EBOV) as a human pathogen relates at the molecular level primarily to blockade the host cell type I interferon (IFN) antiviral response. Most individuals who survive Ebola virus disease (EVD) develop a chronic disease syndrome: approximately one-quarter of survivors suffer from uveitis, which has been associated with presence of EBOV within the eye. Clinical observations of post-Ebola uveitis indicate involvement of retinal pigment epithelial cells. Methods We inoculated ARPE-19 human retinal pigment epithelial cells with EBOV, and followed course of infection by immunocytochemistry and measurement of titer in culture supernatant. To interrogate transcriptional responses of infected cells, we combined RNA sequencing with in silico pathway, gene ontology, transcription factor binding site, and network analyses. We measured infection-induced changes of selected transcripts by reverse transcription-quantitative polymerase chain reaction. Results Human retinal pigment epithelial cells were permissive to infection with EBOV, and supported viral replication and release of virus in high titer. Unexpectedly, 28% of 560 upregulated transcripts in EBOV-infected cells were type I IFN responsive, indicating a robust type I IFN response. Following EBOV infection, cells continued to express multiple immunomodulatory molecules linked to ocular immune privilege. Conclusions Human retinal pigment epithelial cells may serve as an intraocular reservoir for EBOV, and the molecular response of infected cells may contribute to the persistence of live EBOV within the human eye. Translational Relevance This bedside-to-bench research links ophthalmic findings in survivors of EVD who suffer from uveitis with interactions between retinal pigment epithelial cells and EBOV. PMID:28721309

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 were built using well-characterized pigments to determine the influence of particle size and particle size distribution on coating application solids, coatings immobilization solids on coating gloss and print attributes. This research consists of five articles which have all been accepted for publication: (1) Influence of Pigment Particles on the Gloss and Printability of Inkjet Coated Papers, (2) Influence of Silica and Alumina Oxide Pigments on Coating Structure and Print Quality of Inkjet Papers, (3) Production of a Single Coated Glossy Inkjet Paper Using Conventional Coating and Calendering Methods, (4) Influence of Pigment Particle Size and Packing Volume on the Printability of Glossy Inkjet Paper Coatings-Part I, and (5) Influence of Pigment Selection on Printability of Glossy Inkjet Paper Coatings-Part II.

Comparative chemical characterization of pigmented and less pigmented cell walls of Alternaria tenuissima.

PubMed

Kishore, Kankipati Hara; Kanjilal, Sanjit; Misra, Sunil; Reddy, Chinnathimma Rajagopal; Murty, Upadyayula Suryanarayana

2005-12-01

Alternaria tenuissima, the parasitic fungus, was obtained from the pruned upper-cut surfaces of mulberry stems. This fungus contains dark pigment because of the presence of melanin in the cell wall. To obtain less-pigmented cell walls, this fungus was grown under dark condition. When the pigmented and less-pigmented cell walls were chemically analyzed, no differences were observed in amino-acid composition, hexoses, or pentoses. However, in pigmented cell walls, higher contents of melanin (2.6%) were found than in less-pigmented cell walls (0.3%). Interestingly, a significant difference was observed in the relative fatty-acid compositions between these two types of cell walls. Among the major fatty acids, there were increased concentrations of tetradecanoic acid (C14:0), hexadecanoic acid (C16:0), 9-hexadecenoic acid (C16: 1,Delta 9), and 9-octadecanoic acid (C18:1,Delta 9) and a concomitant decrease in 9,12-octadecadienoic acid (C18:2,Delta 9,12) in less-pigmented compared with pigmented cell walls. This difference in fatty-acid composition may be related to the higher percentage of melanin in the pigmented than the less-pigmented cell walls. Lesser amounts of 9,12-octadecadienoic acid in less-pigmented cell walls may have been caused by the growth of the fungus under environmental stress conditions. An interesting observation was the presence in pigmented cell walls only of methyl-substituted fatty acids with carbon numbers C14 to C17, but their occurrence could not be ascertained in the present study.

Studying melanin and lipofuscin in RPE cell culture models

PubMed Central

Boulton, Michael E

2014-01-01

The retinal pigment epithelium contains three major types of pigment granules; melanosomes, lipofuscin and melanolipofuscin. Melanosomes in the retinal pigment epithelium (RPE) are formed during embryogenesis and mature during early postnatal life while lipofuscin and melanolipofuscin granules accumulate as a function of age. The difficulty in studying the formation and consequences of melanosomes and lipofuscin granules in RPE cell culture is compounded by the fact that these pigment granules do not normally occur in established RPE cell lines and pigment granules are rapidly lost in adult human primary culture. This review will consider options available for overcoming these limitations and permitting the study of melanosomes and lipofuscin in cell culture and will briefly evaluate the advantages and disadvantages of the different protocols. PMID:25152361

The impact of human immunodeficiency virus-related diseases on pigmented skin types.

PubMed

Ameen, M

2013-10-01

Infection with human immunodeficiency virus (HIV) remains a significant problem globally. Early diagnosis and treatment with antiretroviral drugs has considerably improved health outcomes and decreased disease-related morbidity. HIV infection is associated with a wide range of skin disorders enabling dermatologists to diagnose HIV as well as associated opportunistic infections early in the course of disease. Despite concerted efforts by international health organizations to limit disease incidence, the prevalence of HIV infection remains high and is highest in sub-Saharan Africa. The diagnosis of HIV-related skin diseases is challenging as immunosuppression often results in atypical disease presentation. In addition, the clinical presentation will vary in pigmented skin types. The aim of this article is to describe disease variation in pigmented skin types. © 2013 The Author BJD © 2013 British Association of Dermatologists.

Enological Tannin Effect on Red Wine Color and Pigment Composition and Relevance of the Yeast Fermentation Products.

PubMed

García-Estévez, Ignacio; Alcalde-Eon, Cristina; Puente, Víctor; Escribano-Bailón, M Teresa

2017-11-23

Enological tannins are widely used in the winemaking process either to improve different wine characteristics (color stability, among others) or to compensate for low tannin levels. In this work, the influence of the addition of two different enological tannins, mainly composed of hydrolysable (ellagitannins) and condensed tannins, on the evolution of color and pigment composition of two different types of model systems containing the five main grape anthocyanins was studied. In addition, the effect of the addition of an enological tannin on the color and pigment composition of red wines made from Vitis vinifera L. cv Tempranillo grapes was also studied by high-performance liquid chromatography with diode array detection coupled to mass spectrometry (HPLC-DAD-MS). Results showed that, in model systems, the addition of the enological tannin favored the formation of anthocyanin-derived pigments, such as A-type and B-type vitisins and flavanol-anthocyanin condensation products, provided that the yeast precursors were previously supplied. Moreover, model systems containing the enological tannins were darker and showed higher values of chroma at the end of the study than control ones. The higher formation of these anthocyanin-derived pigments was also observed in the red wines containing the enological tannin. Moreover, these wine also showed lower lightness (L*) values and higher chroma (C* ab ) values than control wines, indicating a higher stabilization of color.

Ultrastructure and morphogenesis of the wing scales in Heliconius erato phyllis (Lepidoptera: Nymphalidae): what silvery/brownish surfaces can tell us about the development of color patterning?

PubMed

Aymone, A C B; Valente, V L S; de Araújo, A M

2013-09-01

Usually the literature on Heliconius show three types of scales, classified based on the correlation between color and ultrastructure: type I - white and yellow, type II - black, and type III - orange and red. The ultrastructure of the scales located at the silvery/brownish surfaces of males/females is for the first time described in this paper. Besides, we describe the ontogeny of pigmentation, the scale morphogenesis and the maturation timing of scales fated to different colors in Heliconius erato phyllis. The silvery/brownish surfaces showed ultrastructurally similar scales to the type I, II and III. The ontogeny of pigmentation follows the sequence red, black, silvery/brownish and yellow. The maturation of yellow-fated scales, however, occurred simultaneously with the red-fated scales, before the pigmentation becomes visible. In spite of the scales at the silvery/brownish surfaces being ultrastructurally similar to the yellow, red and black scales, they mature after them; this suggests that the maturation timing does not show a relationship with the scale ultrastructure, with the deposition timing of the yellow pigment. The analysis of H. erato phyllis scale morphogenesis, as well as the scales ultrastructure and maturation timing, provided new findings into the developmental architecture of color pattern in Heliconius. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ocean color measurements

NASA Technical Reports Server (NTRS)

Gordon, H. R.; Austin, R. W.; Clark, D. K.; Hovis, W. A.; Yentsch, C. S.

1985-01-01

Ocean color observations by the Coastal Zone color scanner (CZCS) aboard the Nimbus-7 satellite are discussed, together with the factors contributing to the 'apparent' color of the ocean. The CZCS optical systems and the tecniques for extraction of the phytoplankton pigment concentration and the diffuse attenuation coefficient K from the 'apparent' water color are described in detail. Special consideration is given to the use of biooptical algorithms and the development of the K algorithm for the CZCS imagery. It is shown that under typical atmospheric conditions, the pigment concentration can be extracted from the satellite imagery to within + or - 30 percent over concentration ranges from 0 to 5 mg/cu m for the Morel case 1 water (Morel and Prieur, 1977), to which the oceanic waters belong as a rule.

Effect of Zinc Phosphate on the Corrosion Behavior of Waterborne Acrylic Coating/Metal Interface

PubMed Central

Wan, Hongxia; Song, Dongdong; Li, Xiaogang; Zhang, Dawei; Gao, Jin; Du, Cuiwei

2017-01-01

Waterborne coating has recently been paid much attention. However, it cannot be used widely due to its performance limitations. Under the specified conditions of the selected resin, selecting the function pigment is key to improving the anticorrosive properties of the coating. Zinc phosphate is an environmentally protective and efficient anticorrosion pigment. In this work, zinc phosphate was used in modifying waterborne acrylic coatings. Moreover, the disbonding resistance of the coating was studied. Results showed that adding zinc phosphate can effectively inhibit the anode process of metal corrosion and enhance the wet adhesion of the coating, and consequently prevent the horizontal diffusion of the corrosive medium into the coating/metal interface and slow down the disbonding of the coating. PMID:28773013

Role of pigmentation in protecting Aspergillus niger conidiospores against pulsed light radiation.

PubMed

Esbelin, Julia; Mallea, Sabine; Ram, Arthur F; Carlin, Frédéric

2013-01-01

The photoprotective potential of fungus pigments was investigated by irradiating conidiospores of three Aspergillus niger strains possessing the same genetic background, but differing in their degree of pigmentation with pulsed light (PL) and monochromatic (254 nm) UV-C radiation. Spores of A. niger MA93.1 and JHP1.1 presenting, respectively, a fawn and a white pigmentation were more sensitive to PL and continuous UV-C radiation than the wild-type A. niger strain N402 possessing a dark pigment. Both spores of the dark A. niger N402 and the fawn-color mutant were equally resistant to moist heat at 56°C while spores of the white-color mutant were highly sensitive. These results indicate that melanin protects pigmented spores of A. niger from PL. © 2013 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2013 The American Society of Photobiology.

Cysteine reacts to form blue-green pigments with thiosulfinates obtained from garlic (Allium sativum L.).

PubMed

Shin, Young Keum; Kyung, Kyu Hang

2014-01-01

Cysteine was found to form pigments with garlic thiosulfinates in this investigation, in contrast to previous reports. Pigments were formed only when the molar concentration ratios of cysteine to total thiosulfinates were smaller than 2:1. Cysteine does not form pigments with thiosulfinates in the same manner as other pigment-forming amino compounds because it has a sulfhydryl (SH) group. A colour reaction of cysteine with thiosulfinates is proposed where colourless disulphide-type S-alk(en)yl mercaptocysteines (SAMCs) are formed first by the SH-involved reaction between cysteine and thiosulfinates, and then SAMCs react with residual thiosulfinates to form pigments. When the cysteine to total thiosulfinate molar concentration ratio was 2:1 or greater, total thiosulfinates were consumed to form SAMCs without leaving any thiosulfinates remaining available for the following colour reactions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Molecular basis of abnormal red-green color vision: a family with three types of color vision defects.

PubMed Central

Drummond-Borg, M; Deeb, S; Motulsky, A G

1988-01-01

The molecular nature of three different types of X-linked color-vision defects, protanomaly, deuteranomaly, and protanopia, in a large 3-generation family was determined. In the protanomalous and protanopic males the normal red pigment gene was replaced by a 5' red-3' green fusion gene. The protanomalous male had more red pigment DNA in his fusion gene than did the more severely affected protanopic individual. The deuteranomalous individual had four green pigment genes and one 5' green-3' red fusion gene. These results extend those of Nathans et al., who proposed that most red-green color-vision defects arise as a result of unequal crossing-over between the red and green pigment genes. The various data suggest that differences in severity of color-vision defects associated with fusion genes are caused by differences in crossover sites between the red and green pigment genes. Currently used molecular methodology is not sufficiently sensitive to define these fusion points accurately, and the specific color-vision defect within the deutan or protan class cannot be predicted. The DNA patterns for color-vision genes of female heterozygotes have not previously been described. Patterns of heterozygotes may not be distinguishable from those of normals. However, a definite assignment of the various color pigment gene arrays could be carried out by family study. Two compound heterozygotes for color-vision defects who tested as normal by anomaloscopy were found to carry abnormal fusion genes. In addition, a normal red pigment gene was present on one chromosome and at least one normal green pigment gene was present on the other.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 3 PMID:2847528

Variation of calcium, copper and iron levels in serum, bile and stone samples of patients having different types of gallstone: A comparative study.

PubMed

Khan, Mustafa; Kazi, Tasneem Gul; Afridi, Hassan Imran; Sirajuddin; Bilal, Muhammad; Akhtar, Asma; Khan, Sabir; Kadar, Salma

2017-08-01

Epidemiological data among the human population has shown a significantly increased incidence of gallstone (GS) disease worldwide. It was studied that some essential (calcium) and transition elements (iron and copper) in bile play an important role in the development of GS. The estimation of calcium, copper and iron were carried out in the serum, gall bladder bile and different types of GS (cholesterol, mixed and pigmented) of 172 patients, age ranged 20-55years. For comparative purpose age matched referents not suffering from GS diseases were also selected. Biliary concentrations of calcium (Ca), iron (Fe) and copper (Cu) were correlated with their concentrations in serum and different types of GS samples. The ratio of Ca, Fe and Cu in bile with serum was also calculated. Understudy metals were determined by flame atomic absorption spectroscopy after acid decomposition of matrices of selected samples. The Ca concentrations in serum samples were significantly higher in patients with pigmented GS as compared to controls (p<0.005), whereas for patients having cholesterol and mixed GS the concentrations were on the lower side. Biliary Ca concentrations of patients were found to be higher than controls, but difference was significant for pigmented GS patients (p>0.001). The contents of Cu and Fe in serum and bile of all patients (except female cholesterol GS patient have low serum iron concentration) were found to be higher than control, but difference was significant in those patients who have pigmented GS. The concentration of Ca, Fe and Cu in different types GS were found in the order, Pigmented>mixed>cholesterol. The bile/serum ratio for Ca, Cu and Fe was found to be significantly higher in pigmented GS patients. Gall bladder bile was slightly alkaline in patients as compared to referents. The density of bile was found to be higher in patients as compared to the referents. Various functional groups present in different types of GS samples were confirmed by Fourier transform infra-red spectroscopy. The higher density and pH of bile, elevated concentrations of transition elements in all types of biological samples (serum, bile and GS), could be an important factor for the formation of different types of GS. Copyright © 2017 Elsevier B.V. All rights reserved.

Small-sized microplastics and pigmented particles in bottled mineral water.

PubMed

Oßmann, Barbara E; Sarau, George; Holtmannspötter, Heinrich; Pischetsrieder, Monika; Christiansen, Silke H; Dicke, Wilhelm

2018-09-15

Up to now, only a few studies about microparticle contamination of bottled mineral water have been published. The smallest analysed particle size was 5 μm. However, due to toxicological reasons, especially microparticles smaller than 1.5 μm are critically discussed. Therefore, in the present study, 32 samples of bottled mineral water were investigated for contamination by microplastics, pigment and additive particles. Due to the application of aluminium coated polycarbonate membrane filters and micro-Raman spectroscopy, a lowest analysed particle size of 1 μm was achieved. Microplastics were found in water from all bottle types: in single use and reusable bottles made of poly(ethylene terephthalate) (PET) as well as in glass bottles. The amount of microplastics in mineral water varied from 2649 ± 2857 per litre in single use PET bottles up to 6292 ± 10521 per litre in glass bottles. While in plastic bottles, the predominant polymer type was PET; in glass bottles various polymers such as polyethylene or styrene-butadiene-copolymer were found. Hence, besides the packaging itself, other contamination sources have to be considered. Pigment particles were detected in high amounts in reusable, paper labelled bottles (195047 ± 330810 pigment particles per litre in glass and 23594 ± 25518 pigment particles per litre in reusable paper labelled PET bottles). Pigment types found in water samples were the same as used for label printing, indicating the bottle cleaning process as possible contamination route. Furthermore, on average 708 ± 1024 particles per litre of the additive Tris(2,4-di-tert-butylphenyl)phosphite were found in reusable PET bottles. This additive might be leached out from the bottle material itself. Over 90% of the detected microplastics and pigment particles were smaller than 5 μm and thus not covered by previous studies. In summary, this is the first study reporting about microplastics, pigment and additive particles found in bottled mineral water samples with a smallest analysed particle size of 1 μm. Copyright © 2018 Elsevier Ltd. All rights reserved.

Bio-Optical Properties of the Arabian Sea as Determined by In Situ and Sea WiFS Data

NASA Technical Reports Server (NTRS)

Trees, Charles C.

1997-01-01

The overall objective of this work was to characterize optical and fluorescence properties in the euphotic zone during two British Ocean Flux Study (BOFS) Arabian Sea cruises. This was later expanded in 1995 to include three U.S. JGOFS Arabian Sea Cruises. The region was to be divided into one or more "bio-optical provinces," within each of which a single set of regression models was to be developed to relate the vertical distribution of irradiance attenuation and normalized fluorescence (SF and NF) to remote sensing reflectance and diffuse attenuation coefficient. The working hypothesis was that over relatively large spatial and temporal scales, the vertical profiles of bio-optical properties were predictable. The specific technical objectives were: (1) To characterize the vertical distribution of the inherent and apparent optical properties by measuring downwelling and upwelling irradiances, upwelling radiances, scalar irradiance of PAR, and beam transmissions at each station - from these data, spectral diffuse attenuation coefficients, irradiance reflectances, remote sensing reflectances, surface-leaving radiances and beam attenuation coefficients were determined; (2) To characterize the spectral absorption of total particulate, detrital, and dissolved organic material at each station from discrete water samples; (3) To describe the vertical distribution of photoadaptive properties in the water column by measuring profiles of stimulated (SF) and natural (NF) fluorescence and examining relationships between SF and NF as a function of diffuse optical depth, pigment biomass and primary productivity; and (4) To establish locally derived, in-water algorithms relating remote sensing reflectance spectra to diffuse attenuation coefficients, phytoplankton pigment concentrations and primary productivity, through intercomparisons with in situ measurements, for application to SeaWiFS data.

Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill.

PubMed

González, Alfredo; Crittenden, Elizabeth L; García, Dana M

2004-07-13

In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and muscarinic. Muscarinic receptors are in the G-protein coupled receptor superfamily, and five different muscarinic receptors have been molecularly cloned in human. These receptors are coupled to adenylyl cyclase, calcium mobilization and ion channel activation. To determine the receptor pathway involved in eliciting pigment granule migration, we isolated retinal pigment epithelium from bluegill and subjected it to a battery of cholinergic agents. The general cholinergic agonist carbachol induces pigment granule dispersion in isolated retinal pigment epithelium. Carbachol-induced pigment granule dispersion is blocked by the muscarinic antagonist atropine, by the M1 antagonist pirenzepine, and by the M3 antagonist 4-DAMP. Pigment granule dispersion was also induced by the M1 agonist 4-[N-(4-chlorophenyl) carbamoyloxy]-4-pent-2-ammonium iodide. In contrast the M2 antagonist AF-DX 116 and the M4 antagonist tropicamide failed to block carbachol-induced dispersion, and the M2 agonist arecaidine but-2-ynyl ester tosylate failed to elicit dispersion. Our results suggest that carbachol-mediated pigment granule dispersion occurs through the activation of Modd muscarinic receptors, which in other systems couple to phosphoinositide hydrolysis and elevation of intracellular calcium. This conclusion must be corroborated by molecular studies, but suggests Ca2+-dependent pathways may be involved in light-adaptive pigment dispersion.

Phosphorylation-independent suppression of light-activated visual pigment by arrestin in carp rods and cones.

PubMed

Tomizuka, Junko; Tachibanaki, Shuji; Kawamura, Satoru

2015-04-10

Visual pigment in photoreceptors is activated by light. Activated visual pigment (R*) is believed to be inactivated by phosphorylation of R* with subsequent binding of arrestin. There are two types of photoreceptors, rods and cones, in the vertebrate retina, and they express different subtypes of arrestin, rod and cone type. To understand the difference in the function between rod- and cone-type arrestin, we first identified the subtype of arrestins expressed in rods and cones in carp retina. We found that two rod-type arrestins, rArr1 and rArr2, are co-expressed in a rod and that a cone-type arrestin, cArr1, is expressed in blue- and UV-sensitive cones; the other cone-type arrestin, cArr2, is expressed in red- and green-sensitive cones. We quantified each arrestin subtype and estimated its concentration in the outer segment of a rod or a cone in the dark; they were ∼0.25 mm (rArr1 plus rArr2) in a rod and 0.6-0.8 mm (cArr1 or cArr2) in a cone. The effect of each arrestin was examined. In contrast to previous studies, both rod and cone arrestins suppressed the activation of transducin in the absence of visual pigment phosphorylation, and all of the arrestins examined (rArr1, rArr2, and cArr2) bound transiently to most probably nonphosphorylated R*. One rod arrestin, rArr2, bound firmly to phosphorylated pigment, and the other two, rArr1 and cArr2, once bound to phosphorylated R* but dissociated from it during incubation. Our results suggested a novel mechanism of arrestin effect on the suppression of the R* activity in both rods and cones. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Ultrastructures and classification of circulating hemocytes in 9 botryllid ascidians (chordata: ascidiacea).

PubMed

Hirose, Euichi; Shirae, Maki; Saito, Yasunori

2003-05-01

Ultrastructures of circulating hemocytes were studied in 9 botryllid ascidians. The hemocytes are classified into five types: hemoblasts, phagocytes, granulocytes, morula cells, and pigment cells. These five types are always found in the 9 species. They should represent the major hemocyte types of the circulating cells in the blood. Hemoblasts are small hemocytes having a high nucleus/cytoplasm ratio. There are few granular or vacuolar inclusions in the cytoplasm. Phagocytes have phagocytic activity and their shape is variable depending on the amount of engulfed materials. In granulocytes, shape and size of granules are different among the species. Morula cells are characterized by several vacuoles filled with electron dense materials. In pigment cells, the bulk of the cytoplasm is occupied by one or a few vacuoles containing pigment granules. We also described some other hemocyte types found in particular species. Furthermore, we encountered free oocytes circulating in the blood in two species, Botryllus primigenus and Botrylloides lentus.

Application of Electron Paramagnetic Resonance to Study of Gallstones

NASA Astrophysics Data System (ADS)

Kiselev, S. A.; Tsyro, L. V.; Afanasiev, D. A.; Unger, F. G.; Soloviev, M. M.

2014-03-01

We present the results of an electron paramagnetic resonance (EPR) study of mixed cholesterol gallstones. We have established that free radicals are distributed nonuniformly within the interior of the stone. The type and number of paramagnetic centers depend on the pigment content in the selected layer. We show that the parameters of the sextet lines in the EPR spectrum of the pigment are close to the parameters of lines in the spectrum of a brown pigment stone.

Cellulosic/wool pigment prints with remarkable antibacterial functionalities.

PubMed

Ibrahim, N A; Eid, B M; Khalil, H M

2015-01-22

Several bio-active agents namely choline chloride, triclosan derivative, PEG-600 and 4-hydroxybenzophenone were successfully included into solvent-free pigment formulations, in a single-stage process, followed by screen printing and microwave-fixation to obtain antibacterial functionalized cellulosic/wool pigment prints. Results obtained signify that both the improvement in functionalization and coloration properties are governed by type of antibacterial agent, kind of substrate as well as pigment colorant. The imparted antibacterial activity of the loaded bio-active agents follows the decreasing order: G+ve (Staphylococcus aureus)>G-ve (Escherichia coli), keeping other parameters constant. The imparted functional and coloration properties showed no significant decrease even after 15 washings. Mode of interactions among the nominated substrates, the pigment paste constituents and the bioactive agents were also proposed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pigment variations in Emiliania huxleyi (CCMP370) as a response to changes in light intensity or quality.

PubMed

Garrido, José L; Brunet, Christophe; Rodríguez, Francisco

2016-12-01

Many studies on photoacclimation examine the pigment responses to changes in light intensity, but variations in light climate in the aquatic environment are also related to changes in spectral composition. We have employed a high-performance liquid chromatography method with improved resolution towards chlorophyll c and fucoxanthin-related xanthophylls to examine the pigment composition of Emiliania huxleyi CCMP 370 under different light intensities and spectral qualities. To maintain its photosynthetic performance, E. huxleyi CCMP370 promotes drastic pigment changes that can be either the interconversion of pigments in pools with the same basic chromophoric structure (Fucoxanthin type or chlorophyll c type), or the ex novo synthesis (Diatoxanthin). These changes are linked either to variations in light quality (Fucoxanthin related xanthophylls) or in light intensity (chlorophyll c 3 /Monovinyl chlorophyll c 3 , Diadinoxanthin/Diatoxanthin, β,ɛ-carotene/ β,β-carotene). Fucoxanthin and 19'-hexanoyloxyfucoxanthin proportions were highly dependent on spectral conditions. Whereas Fucoxanthin dominated in green and red light, 19'-hexanoyloxyfucoxanthin prevailed under blue spectral conditions. Our results suggest that the huge pigment diversity enhanced the photoacclimative capacities of E. huxleyi to efficiently perform under changing light environments. The ubiquity and success in the global ocean as well as the capacity of E. huxleyi to form large surface blooms might be associated to the plasticity described here. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Step of Dichlorvos Inhibition in the Pathway of Aflatoxin Biosynthesis

PubMed Central

Yao, Raymond C.; Hsieh, Dennis P. H.

1974-01-01

Dichlorvos (dimethyl 2,2-dichlorovinyl phosphate) inhibits the biosynthesis of aflatoxin by Aspergillus parasiticus. Cultures treated with dichlorvos excrete an orange pigment which can be converted into aflatoxin B1 by the untreated mycelia. The orange pigment was partially identified as an acetyl derivative of versiconol-type compound. In the presence of dichlorvos, sterigmatocystin is converted into aflatoxin B1 without being interfered, but averufin is converted into the orange pigment instead of aflatoxin B1. Therefore, dichlorvos appears to block an enzymatic step in the aflatoxin biosynthetic pathway, which lies beyond averufin but before sterigmatocystin, at the formation of the orange pigment. PMID:4844267

Methylobacterium suomiense sp. nov. and Methylobacterium lusitanum sp. nov., aerobic, pink-pigmented, facultatively methylotrophic bacteria.

PubMed

Doronina, Nina V; Trotsenko, Yuri A; Kuznetsov, Boris B; Tourova, Tatjana P; Salkinoja-Salonen, Mirja S

2002-05-01

Two aerobic, pink-pigmented, facultatively methylotrophic bacteria, strains F20T and RXM(T), are described taxonomically. On the basis of their phenotypic and genotypic properties, the isolates are proposed as novel species of the genus Methylobacterium, Methylobacterium suomiense sp. nov. (type strain F20T = VKM B-2238T = NCIMB 13778T) and Methylobacterium lusitanum sp. nov. (type strain RXMT = VKM B-2239T = NCIMB 13779T).

[Effect of long-wave ultraviolet light (UV-A) and medium-wave ultraviolet rays (UV-B) on human skin. Critical comparison].

PubMed

Raab, W

1980-04-15

When discussing the effects of ultraviolet radiation on human skin, one should carefully distinguish between the long wave ultraviolet light (UV-A) and the short wave radiations (UV-B and UV-C). Ultraviolet A induces immediate pigmentation but, if high energies are applied, a permanent pigmentation is elicited. This type of ultraviolet A-induced pigmentation has been called "spontaneous" pigmentation as no erythematous reaction is necessary to induce or accelerate melanine formation. Ultraviolet B provokes erythema and consecutive pigmentation. Upon chronic exposure, ultraviolet B causes the wellknown actinic damage of the skin and even provokes carcinoma. With exposures to the sunlight (global radiation), one should be most careful. The public must be informed extensively about the dangers of excessive sunbaths. The use of artificial "suns" with spectra between 260 and 400 nm is limited as it may cause the same type of damage as the global radiation. An exact schedule for use of artificial lamps is strongly recommended. After one cycle of exposures, an interruption is necessary until the next cycle of irradiations may start. Upon continual use for tanning of the skin, artificial lamps may provoke irreversible damage of the skin. Radiation sources with emission spectra of wavelengths between 315 and 400 nm exclusively are well suited for the induction of skin pigmentation (cosmetic use). Potent radiation such as UVASUN systems provoke a "pleasant" permanent pigmentation after exposures for less than one hour. The use of ultraviolet A (UV-A) does not carry any risk for the human skin.

Proof-of-concept: 3D bioprinting of pigmented human skin constructs.

PubMed

Ng, Wei Long; Qi, Jovina Tan Zhi; Yeong, Wai Yee; Naing, May Win

2018-01-23

Three-dimensional (3D) pigmented human skin constructs have been fabricated using a 3D bioprinting approach. The 3D pigmented human skin constructs are obtained from using three different types of skin cells (keratinocytes, melanocytes and fibroblasts from three different skin donors) and they exhibit similar constitutive pigmentation (pale pigmentation) as the skin donors. A two-step drop-on-demand bioprinting strategy facilitates the deposition of cell droplets to emulate the epidermal melanin units (pre-defined patterning of keratinocytes and melanocytes at the desired positions) and manipulation of the microenvironment to fabricate 3D biomimetic hierarchical porous structures found in native skin tissue. The 3D bioprinted pigmented skin constructs are compared to the pigmented skin constructs fabricated by conventional a manual-casting approach; in-depth characterization of both the 3D pigmented skin constructs has indicated that the 3D bioprinted skin constructs have a higher degree of resemblance to native skin tissue in term of the presence of well-developed stratified epidermal layers and the presence of a continuous layer of basement membrane proteins as compared to the manually-cast samples. The 3D bioprinting approach facilitates the development of 3D in vitro pigmented human skin constructs for potential toxicology testing and fundamental cell biology research.

Melanin targeting for intracellular drug delivery: Quantification of bound and free drug in retinal pigment epithelial cells.

PubMed

Rimpelä, Anna-Kaisa; Hagström, Marja; Kidron, Heidi; Urtti, Arto

2018-05-31

Melanin binding affects drug distribution and retention in pigmented ocular tissues, thereby affecting drug response, duration of activity and toxicity. Therefore, it is a promising possibility for drug targeting and controlled release in the pigmented cells and tissues. Intracellular unbound drug concentrations determine pharmacological and toxicological actions, but analyses of unbound vs. total drug concentrations in pigmented cells are lacking. We studied intracellular binding and cellular drug uptake in pigmented retinal pigment epithelial cells and in non-pigmented ARPE-19 cells with five model drugs (chloroquine, propranolol, timolol, diclofenac, methotrexate). The unbound drug fractions in pigmented cells were 0.00016-0.73 and in non-pigmented cells 0.017-1.0. Cellular uptake (i.e. distribution ratio Kp), ranged from 1.3 to 6300 in pigmented cells and from 1.0 to 25 in non-pigmented cells. Values for intracellular bioavailability, F ic , were similar in both cells types (although larger variation in pigmented cells). In vitro melanin binding parameters were used to predict intracellular unbound drug fraction and cell uptake. Comparison of predictions with experimental data indicates that other factors (e.g. ion-trapping, lipophilicity-related binding to other cell components) also play a role. Melanin binding is a major factor that leads to cellular uptake and unbound drug fractions of a range of 3-4 orders of magnitude indicating that large reservoirs of melanin bound drug can be generated in the cells. Understanding melanin binding has important implications on retinal drug targeting, efficacy and toxicity. Copyright © 2017. Published by Elsevier B.V.

Coat color genetics of Peromyscus: IV. Variable white, a new dominant mutation in the deer mouse.

PubMed

Cowling, K; Robbins, R J; Haigh, G R; Teed, S K; Dawson, W D

1994-01-01

The variable white mutation arose spontaneously in 1983 within a laboratory stock of wild-type deer mice (Peromyscus maniculatus). The original mutant animal was born to a wild-type pair that had previously produced several entirely wild-type litters. Other variable white animals were bred from the initial individual. Variable white deer mice exhibit extensive areas of white on the head, sides, and tail. Usually a portion of pigmented pelage occurs dorsally and on the shoulders, but the extent of white varies from nearly all white to patches of white on the muzzle, tip of tail, and sides. The pattern is irregular, but not entirely asymmetrical. Eyes are pigmented, but histologically reveal a decrease in thickness and pigmentation of the choroid layer. Many variable white animals do not respond to auditory stimuli, an effect that is particularly evident in animals in which the head is entirely white. Ataxic behavior is also prevalent. Pigment distribution, together with auditory and retinal deficiencies, suggests a neural crest cell migration defect. Breeding data are consistent with an autosomal semidominant, lethal mode of inheritance. The trait differs from two somewhat similar variants in Peromyscus: from dominant spot (S) in extent and pattern of pigmentation and from whiteside (ws), an autosomal recessive trait, in the mode of inheritance and viability. Evidence for possible homology with the Va (varitint-waddler) locus in house mouse (Mus) is presented. The symbol Vw is tentatively assigned for the variable white locus in Peromyscus.

Pigment Translocation in Caridean Shrimp Chromatophores: Receptor Type, Signal Transduction, Second Messengers, and Cross Talk Among Multiple Signaling Cascades.

PubMed

Milograna, Sarah Ribeiro; Ribeiro, Márcia Regina; Bell, Fernanda Tinti; McNamara, John Campbell

2016-11-01

Pigment aggregation in shrimp chromatophores is triggered by red pigment concentrating hormone (RPCH), a neurosecretory peptide whose plasma membrane receptor may be a G-protein coupled receptor (GPCR). While RPCH binding activates the Ca 2+ /cGMP signaling cascades, a role for cyclic AMP (cAMP) in pigment aggregation is obscure, as are the steps governing Ca 2+ release from the smooth endoplasmic reticulum (SER). A role for the antagonistic neuropeptide, pigment dispersing homone (α-PDH) is also unclear. In red, ovarian chromatophores from the freshwater shrimp Macrobrachium olfersi, we show that a G-protein antagonist (AntPG) strongly inhibits RPCH-triggered pigment aggregation, suggesting that RPCH binds to a GPCR, activating an inhibitory G-protein. Decreasing cAMP levels may cue pigment aggregation, since cytosolic cAMP titers, when augmented by cholera toxin, forskolin or vinpocentine, completely or partially impair pigment aggregation. Triggering opposing Ca 2+ /cGMP and cAMP cascades by simultaneous perfusion with lipid-soluble cyclic nucleotide analogs induces a "tug-of-war" response, pigments aggregating in some chromatosomes with unpredictable, oscillatory movements in others. Inhibition of cAMP-dependent protein kinase accelerates aggregation and reduces dispersion velocities, suggesting a role in phosphorylation events, possibly regulating SER Ca 2+ release and pigment aggregation. The second messengers IP 3 and cADPR do not stimulate SER Ca 2+ release. α-PDH does not sustain pigment dispersion, suggesting that pigment translocation in caridean chromatophores may be regulated solely by RPCH, since PDH is not required. We propose a working hypothesis to further unravel key steps in the mechanisms of pigment translocation within crustacean chromatophores that have remained obscure for nearly a century. © 2016 Wiley Periodicals, Inc.

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.

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

PubMed Central

Yu, Yue; Li, Zhanming

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. PMID:27019785

Algal Accessory Pigment Detection Using AVIRIS Image-Derived Spectral Radiance Data

NASA Technical Reports Server (NTRS)

Richardson, Laurie L.; Ambrosia, Vincent G.

1996-01-01

Visual and derivative analyses of AVIRIS spectral data can be used to detect algal accessory pigments in aquatic communities. This capability extends the use of remote sensing for the study of aquatic ecosystems by allowing detection of taxonomically significant pigment signatures which yield information about the type of algae present. Such information allows remote sensing-based assessment of aquatic ecosystem health, as in the detection of nuisance blooms of cyanobacteria or toxic blooms of dinoflagellates. Remote sensing of aquatic systems has traditionally focused on quantification of chlorophyll a, a photoreactive (and light-harvesting) pigment which is common to all algae as well as cyanobacteria (bluegreen algae). Due to the ubiquitousness of this pigment within algae, chl a is routinely measured to estimate algal biomass both during ground-truthing and using various airborne or satellite based sensors, including AVIRIS. Within the remote sensing and aquatic sciences communities, ongoing research has been performed to detect algal accessory pigments for assessment of algal population composition. This research is based on the fact that many algal accessory pigments are taxonomically significant, and all are spectrally unique. Aquatic scientists have been refining pigment analysis techniques, primarily high performance liquid chromatography, or HPLC, to detect specific pigments as a time-saving alternative to individual algal cell identifications and counts. Remote sensing scientists are investigating the use of pigment signatures to construct pigment libraries analogous to mineral spectral libraries used in geological remote sensing applications. The accessory pigment approach has been used successfully in remote sensing using data from the Thematic Mapper, low-altitude, multiple channel scanners, field spectroradiometers and the AVIRIS hyperspectral scanner. Due to spectral and spatial resolution capabilities, AVIRIS is the sensor of choice for such studies. We present here our results on detection of algal accessory pigments using AVIRIS data.

Spectrophotometric Analysis of Pigments: A Critical Assessment of a High-Throughput Method for Analysis of Algal Pigment Mixtures by Spectral Deconvolution

PubMed Central

Thrane, Jan-Erik; Kyle, Marcia; Striebel, Maren; Haande, Sigrid; Grung, Merete; Rohrlack, Thomas; Andersen, Tom

2015-01-01

The Gauss-peak spectra (GPS) method represents individual pigment spectra as weighted sums of Gaussian functions, and uses these to model absorbance spectra of phytoplankton pigment mixtures. We here present several improvements for this type of methodology, including adaptation to plate reader technology and efficient model fitting by open source software. We use a one-step modeling of both pigment absorption and background attenuation with non-negative least squares, following a one-time instrument-specific calibration. The fitted background is shown to be higher than a solvent blank, with features reflecting contributions from both scatter and non-pigment absorption. We assessed pigment aliasing due to absorption spectra similarity by Monte Carlo simulation, and used this information to select a robust set of identifiable pigments that are also expected to be common in natural samples. To test the method’s performance, we analyzed absorbance spectra of pigment extracts from sediment cores, 75 natural lake samples, and four phytoplankton cultures, and compared the estimated pigment concentrations with concentrations obtained using high performance liquid chromatography (HPLC). The deviance between observed and fitted spectra was generally very low, indicating that measured spectra could successfully be reconstructed as weighted sums of pigment and background components. Concentrations of total chlorophylls and total carotenoids could accurately be estimated for both sediment and lake samples, but individual pigment concentrations (especially carotenoids) proved difficult to resolve due to similarity between their absorbance spectra. In general, our modified-GPS method provides an improvement of the GPS method that is a fast, inexpensive, and high-throughput alternative for screening of pigment composition in samples of phytoplankton material. PMID:26359659

The effect of dietary carotenoid access on sexual dichromatism and plumage pigment composition in the American goldfinch.

PubMed

McGraw, K J; Hill, G E; Stradi, R; Parker, R S

2002-02-01

We investigated potential dietary and biochemical bases for carotenoid-based sexual dichromatism in American goldfinches (Carduelis tristis). Captive male and female finches were given access to the same type and amount of carotenoid pigments in the diet during their nuptial molt to assess differences in the degree to which the two sexes incorporated ingested pigments into their plumage. When birds were fed a uniform, plain-seed diet, or one that was supplemented with the red carotenoid canthaxanthin, we found that males grew more colorful plumage than females. HPLC analyses of feather pigments revealed that male finches incorporated a higher concentration of carotenoids into their pigmented feathers than females. Compared to females, males also deposited significantly more canary xanthophyll B into feathers when fed a plain-seed diet and a greater concentration and proportion of canthaxanthin when fed a carotenoid-supplemented diet. These results indicate that sex-specific expression of carotenoid pigmentation in American goldfinches may be affected by the means by which males and females physiologically utilize (e.g. absorb, transport, metabolize, deposit) carotenoid pigments available to them in the diet.

Regulatory mutations in TBX3 disrupt asymmetric hair pigmentation that underlies Dun camouflage color in horses

PubMed Central

Imsland, Freyja; McGowan, Kelly; Rubin, Carl-Johan; Henegar, Corneliu; Sundström, Elisabeth; Berglund, Jonas; Schwochow, Doreen; Gustafson, Ulla; Imsland, Páll; Lindblad-Toh, Kerstin; Lindgren, Gabriella; Mikko, Sofia; Millon, Lee; Wade, Claire; Schubert, Mikkel; Orlando, Ludovic; Penedo, Maria Cecilia T; Barsh, Gregory S; Andersson, Leif

2016-01-01

Dun is a wild-type coat color in horses characterized by pigment dilution with a striking pattern of dark areas termed primitive markings. Here we show that pigment dilution in Dun horses is due to radially asymmetric deposition of pigment in the growing hair caused by localized expression of the T-box 3 (TBX3) transcription factor in hair follicles, which in turn determines the distribution of hair follicle melanocytes. Most domestic horses are non-dun, a more intensely pigmented phenotype caused by regulatory mutations impairing TBX3 expression in the hair follicle, resulting in a more circumferential distribution of melanocytes and pigment granules in individual hairs. We identified two different alleles (non-dun1 and non-dun2) causing non-dun color. non-dun2 is a recently derived allele, whereas the Dun and non-dun1 alleles are found in ancient horse DNA, demonstrating that this polymorphism predates horse domestication. These findings uncover a new developmental role for T-box genes and new aspects of hair follicle biology and pigmentation. PMID:26691985

Regulation of Human Skin Pigmentation in situ by Repetitive UV Exposure – Molecular Characterization of Responses to UVA and/or UVB

PubMed Central

Choi, Wonseon; Miyamura, Yoshinori; Wolber, Rainer; Smuda, Christoph; Reinhold, William; Liu, Hongfang; Kolbe, Ludger; Hearing, Vincent J.

2012-01-01

Ultraviolet (UV) radiation is a major environmental factor that affects pigmentation in human skin and can eventually result in various types of UV-induced skin cancers. The effects of various wavelengths of UV on melanocytes and other types of skin cells in culture have been studied but little is known about gene expression patterns in situ following in situe exposure of human skin to different types of UV (UVA and/or UVB). Paracrine factors expressed by keratinocytes and/or fibroblasts that affect skin pigmentation might be regulated differently by UV, as might their corresponding receptors expressed on melanocytes. To test the hypothesis that different mechanisms are involved in the pigmentary responses of the skin to different types of UV, we used immunohistochemical and whole human genome microarray analyses to characterize human skin in situ to examine how melanocyte-specific proteins and paracrine melanogenic factors are regulated by repetitive exposure to different types of UV compared with unexposed skin as a control. The results show that gene expression patterns induced by UVA or UVB are distinct, UVB eliciting dramatic increases in a large number of genes involved in pigmentation as well as in other cellular functions, while UVA had little or no effect on those. The expression patterns characterize the distinct responses of the skin to UVA or UVB, and identify several potential previously unidentified factors involved in UV-induced responses of human skin. PMID:20147966

[Diffuse retinal epitheliopathy].

PubMed

Abaloun, Yassine; Omari, Abdelhadi

2017-01-01

We report the case of a 52-year old man with no previous significant medical history presenting with progressive decrease in visual acuity (VA) of the right eye evolving over 10 years. Corrected visual acuity was 2/10 - P6 in the RE and 10/10 - P2 in the LE. The examination of the anterior segment was unremarkable. Fundus examination showed alteration of the pigment epithelium (APE) in the RE associated with osteoblast-like pigment migrations involving the macula and a wide area due to gravitational descent of the superior temporal arcade onto the lower temporal quadrant. The left eye had a similar appearance especially in the inter-papillo-macular region (A,B). Fluorescein angiography showed early hyperfluorescence areas in the PE depigmented areas associated with pigment migrations giving a comet tail appearance by gravity casting in both eyes (C,D). Optical coherence tomography (OCT) showed retrofoveolar epithelial detachment (PED) at the level of the RE (E). The patient received Diamox therapy with regular monitoring to manage possible leakage points. Patient 's evolution was marked by PED regression and VA improvement.

Characterization of the dog agouti gene and a nonagouti mutation in german shepherd dogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerns, Julie A.; Newton, J.; Berryere, Tom G.

The interaction between two genes, Agouti and Melanocortin-1 receptor (Mc1r), produces diverse pigment patterns in mammals by regulating the type, amount, and distribution pattern of the two pigment types found in mammalian hair: eumelanin (brown/black) and pheomelanin (yellow/red). In domestic dogs (Canis familiaris), there is a tremendous variation in coat color patterns between and within breeds; however, previous studies suggest that the molecular genetics of pigment-type switching in dogs may differ from that of other mammals. Here we report the identification and characterization of the Agouti gene from domestic dogs, predicted to encode a 131-amino-acid secreted protein 98 percent identicalmore » to the fox homolog, and which maps to chromosome CFA24 in a region of conserved linkage. Comparative analysis of the Doberman Pinscher Agouti cDNA, the fox cDNA, and 180 kb of Doberman Pinscher genomic DNA suggests that, as with laboratory mice, different pigment-type-switching patterns in the canine family are controlled by alternative usage of different promoters and untranslated first exons. A small survey of Labrador Retrievers, Greyhounds, Australian Shepherds, and German Shepherd Dogs did not uncover any polymorphisms, but we identified a single nucleotide variant in black German Shepherd Dogs predicted to cause an Arg-to-Cys substitution at codon 96, which is likely to account for recessive inheritance of a uniform black coat.« less

Sox5 Functions as a Fate Switch in Medaka Pigment Cell Development

PubMed Central

Nagao, Yusuke; Suzuki, Takao; Shimizu, Atsushi; Kimura, Tetsuaki; Seki, Ryoko; Adachi, Tomoko; Inoue, Chikako; Omae, Yoshihiro; Kamei, Yasuhiro; Hara, Ikuyo; Taniguchi, Yoshihito; Naruse, Kiyoshi; Wakamatsu, Yuko; Kelsh, Robert N.; Hibi, Masahiko; Hashimoto, Hisashi

2014-01-01

Mechanisms generating diverse cell types from multipotent progenitors are crucial for normal development. Neural crest cells (NCCs) are multipotent stem cells that give rise to numerous cell-types, including pigment cells. Medaka has four types of NCC-derived pigment cells (xanthophores, leucophores, melanophores and iridophores), making medaka pigment cell development an excellent model for studying the mechanisms controlling specification of distinct cell types from a multipotent progenitor. Medaka many leucophores-3 (ml-3) mutant embryos exhibit a unique phenotype characterized by excessive formation of leucophores and absence of xanthophores. We show that ml-3 encodes sox5, which is expressed in premigratory NCCs and differentiating xanthophores. Cell transplantation studies reveal a cell-autonomous role of sox5 in the xanthophore lineage. pax7a is expressed in NCCs and required for both xanthophore and leucophore lineages; we demonstrate that Sox5 functions downstream of Pax7a. We propose a model in which multipotent NCCs first give rise to pax7a-positive partially fate-restricted intermediate progenitors for xanthophores and leucophores; some of these progenitors then express sox5, and as a result of Sox5 action develop into xanthophores. Our results provide the first demonstration that Sox5 can function as a molecular switch driving specification of a specific cell-fate (xanthophore) from a partially-restricted, but still multipotent, progenitor (the shared xanthophore-leucophore progenitor). PMID:24699463

Aryl Polyenes, a Highly Abundant Class of Bacterial Natural Products, Are Functionally Related to Antioxidative Carotenoids.

PubMed

Schöner, Tim A; Gassel, Sören; Osawa, Ayako; Tobias, Nicholas J; Okuno, Yukari; Sakakibara, Yui; Shindo, Kazutoshi; Sandmann, Gerhard; Bode, Helge B

2016-02-02

Bacterial pigments of the aryl polyene type are structurally similar to the well-known carotenoids with respect to their polyene systems. Their biosynthetic gene cluster is widespread in taxonomically distant bacteria, and four classes of such pigments have been found. Here we report the structure elucidation of the aryl polyene/dialkylresorcinol hybrid pigments of Variovorax paradoxus B4 by HPLC-UV-MS, MALDI-MS and NMR. Furthermore, we show for the first time that this pigment class protects the bacterium from reactive oxygen species, similarly to what is known for carotenoids. An analysis of the distribution of biosynthetic genes for aryl polyenes and carotenoids in bacterial genomes is presented; it shows a complementary distribution of these protective pigments in bacteria. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

FOX and ETS family transcription factors regulate the pigment cell lineage in planarians.

PubMed

He, Xinwen; Lindsay-Mosher, Nicole; Li, Yan; Molinaro, Alyssa M; Pellettieri, Jason; Pearson, Bret J

2017-12-15

Many pigment cells acquire unique structural properties and gene expression profiles during animal development. The underlying differentiation pathways have been well characterized in cells formed during embryogenesis, such as the neural crest-derived melanocyte. However, much less is known about the developmental origins of pigment cells produced in adult organisms during tissue homeostasis and repair. Here we report a lineage analysis of ommochrome- and porphyrin-producing cells in the brown, freshwater planarian Schmidtea mediterranea Using an RNA-sequencing approach, we identified two classes of markers expressed in sequential fashion when new pigment cells are generated during regeneration or in response to pigment cell ablation. We also report roles for FOXF-1 and ETS-1 transcription factors, as well as for an FGFR-like molecule, in the specification and maintenance of this cell type. Together, our results provide insights into mechanisms of adult pigment cell development in the strikingly colorful Platyhelminthes phylum. © 2017. Published by The Company of Biologists Ltd.

A smart approach to add antibacterial functionality to cellulosic pigment prints.

PubMed

Ibrahim, N A; Eid, B M; Elmaaty, T M Abou; El-Aziz, E Abd

2013-04-15

This study was devoted to enhancing the antibacterial functionality of pigment printed cotton, linen and viscose fabrics. Ag-NP's/PVP colloid, triclosan derivatives, chitosan or choline chloride was successfully incorporated into the pigment paste followed by printing and microwave curing to impart antibacterial activity to the cellulosic prints. Results obtained demonstrate that the modified pigment prints exhibit a remarkable antibacterial activity against the G+ve (Staphylococcus aureus) and G-ve (Escherichia coli) bacteria with a noticeable durability after 20 washing cycles without adversely affecting the printing and softness properties. The extent of printability and functionality of the nominated substrates are significantly governed by the type of: bio-active ingredient, binder, pigment and substrate. TEM, SEM and EDX analysis confirmed the formation of Ag-NP's/PVP colloid, of particle size range 7-14 nm, deposition of cross-linked-binder film onto the modified pigment prints, and the existence of elementary Ag and Si loaded onto fabrics surface, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

A multi-analytical approach for the study of the pigments used in the wall paintings from a building complex on the Caelian Hill (Rome)

NASA Astrophysics Data System (ADS)

Fermo, Paola; Piazzalunga, Andrea; de Vos, Mariette; Andreoli, Martina

2013-12-01

In the present study, shards from Roman wall paintings (from the end of the first century to the fourth century A.D.) decorating the domus below the Basilica of SS. John and Paul on the Caelian Hill (Rome), were analyzed in order to identify the pigments used. The analytical techniques employed for the characterization of the pigments were the scanning electron microscope coupled with an energy dispersive spectrometer (SEM-EDS) and infrared spectroscopy (ATR and micro ATR). While SEM-EDS allowed to perform a qualitative analysis of the material, by FT-IR chemical species have been identified. The pigments identified were those mentioned in the literature for the Imperial Roman fresco painting: different types of ochre (yellow and red), mixtures containing lead, green earths and precious pigments such as cinnabar and Egyptian blue. They were often used as mixtures and the use of the most valuable pigments (cinnabar and Egyptian blue) were found in the most ancient rooms.

Taxonomy, virulence and epidemiology of black-pigmented Bacteroides species in relation to oral infections.

PubMed

van Steenbergen, T J; van Winkelhoff, A J; van der Velden, U; de Graaff, J

1989-01-01

Black-pigmented Bacteroides species are recognized as suspected pathogens of oral infections. Developments in the taxonomy of this group include description of a new asaccharolytic species, Bacteroides salivosus, and proposal for the reclassification of the asaccharolytic species into a separate genus, Porphyromonas. Studies on the pathogenicity and virulence of black-pigmented Bacteroides species have identified Bacteroides gingivalis as the most virulent species. B. gingivalis and Bacteroides intermedius have been associated with periodontal diseases; Bacteroides endodontalis is isolated specifically from infections in the oral cavity, and other black-pigmented Bacteroides species are recovered from oral mucous sites. DNA restriction endonuclease analysis was adapted for typing of B. gingivalis and B. intermedius.

In vivo measurements of cutaneous melanin across spatial scales: using multiphoton microscopy and spatial frequency domain spectroscopy.

PubMed

Saager, Rolf B; Balu, Mihaela; Crosignani, Viera; Sharif, Ata; Durkin, Anthony J; Kelly, Kristen M; Tromberg, Bruce J

2015-06-01

The combined use of nonlinear optical microscopy and broadband reflectance techniques to assess melanin concentration and distribution thickness in vivo over the full range of Fitzpatrick skin types is presented. Twelve patients were measured using multiphoton microscopy (MPM) and spatial frequency domain spectroscopy (SFDS) on both dorsal forearm and volar arm, which are generally sun-exposed and non-sun-exposed areas, respectively. Both MPM and SFDS measured melanin volume fractions between (skin type I non-sun-exposed) and 20% (skin type VI sun exposed). MPM measured epidermal (anatomical) thickness values ~30-65 μm, while SFDS measured melanin distribution thickness based on diffuse optical path length. There was a strong correlation between melanin concentration and melanin distribution (epidermal) thickness measurements obtained using the two techniques. While SFDS does not have the ability to match the spatial resolution of MPM, this study demonstrates that melanin content as quantified using SFDS is linearly correlated with epidermal melanin as measured using MPM (R² = 0.8895). SFDS melanin distribution thickness is correlated to MPM values (R² = 0.8131). These techniques can be used individually and/or in combination to advance our understanding and guide therapies for pigmentation-related conditions as well as light-based treatments across a full range of skin types.

Cutaneous Hyperpigmentation in Megaloblastic Anemia: a Five Year Retrospective Review

PubMed Central

Padhi, Somanath; Sarangi, RajLaxmi; Ramdas, Anita; Ravichandran, Kandasamy; Varghese, Renu G’Boy; Alexander, Thomas; Kurian, George; Mookkappan, Sudhagar

2016-01-01

Background Cutaneous hyperpigmentation is an often overlooked clinical sign in megaloblastic anemia (MA) which has been sporadically reported in the literature. Methods We describe the bone marrow (BM) changes and clinicolaboratory characteristics of 25 of 198 adult cases (>16 years) with cutaneous hyperpigmentation who underwent BM evaluation for cytopenia (s). Results Twenty-one of 25 cases (84%) had MA, while MA without hyperpigmentation occurred only in 12 of remainder 173 cases (P<0.001). Knuckle pad hyperpigmentation (KP) was noted in 16 (64%) cases; whereas 9 (36%) had diffuse brownish black discoloration (DP) of the palms and/or soles. Eighteen of 25 (72%) cases had pancytopenia (13 with KP) and 7 of 25 (28%) had bicytopenia (3 with KP). In addition, five cases (20%) presented with pyrexia. Of the 17 cases where data available, eleven were B12 deficient [<190 pg/ml; eight had severe deficiency (<100 pg/ml); ref.; 190–800pg/ml], while 4 had pure folate deficiency (< 4.0 ng/ml; ref.; 4–20ng/ml); and remainder 2 had combined B12 and folate deficiency. Compared to those with diffuse pigmentation; KP group had lower Hb (69.6 ± 24.2 vs. 86.3 ± 33.9 g/L), higher MCV (106.1 ±12.6 vs. 99.2 ± 7.6 fL), lower platelet count (50.9 ± 29.3 vs. 69.6 ± 36.5 × 109/L), and lower median B12 [100.0 (30.0 – 822.0) vs. 316.0 (142.0 – 1617.3) pg/ml] (P>0.05). In six cases where follow-up data were available, there was a significant reversal of hyperpigmentation at 12 weeks following parenteral cobalamin therapy. In all five cases with pyrexia, fever subsided after 24 to 72 hours following administration of parenteral cobalamin therapy. Conclusion Cutaneous hyperpigmentation and cytopenia (s) are strongly associated with megaloblastic anemia. Knuckle pad hyperpigmentation is much more frequent than diffuse pigmentation of the palms and/or soles in such patents. A nonsignificant trend towards a greater degree of MA was found in cases with pigmentation of the knuckles. PMID:27158434

Variety of genotypes in males diagnosed as dichromatic on a conventional clinical anomaloscope

PubMed Central

CARROLL, JOSEPH; RENNER, AGNES; KNAU, HOLGER; WERNER, JOHN S.; NEITZ, JAY

2008-01-01

The hypothesis that dichromatic behavior on a clinical anomaloscope can be explained by the complement and arrangement of the long- (L) and middle-wavelength (M) pigment genes was tested. It was predicted that dichromacy is associated with an X-chromosome pigment gene array capable of producing only a single functional pigment type. The simplest case of this is when deletion has left only a single X-chromosome pigment gene. The production of a single L or M pigment type can also result from rearrangements in which multiple genes remain. Often, only the two genes at the 5′ end of the array are expressed; thus, dichromacy is also predicted to occur if one of these is defective or encodes a defective pigment, or if both of them encode pigments with identical spectral sensitivities. Subjects were 128 males who accepted the full range of admixtures of the two primary lights as matching the comparison light on a Neitz or Nagel anomaloscope. Strikingly, examination of the L and M pigment genes revealed a potential cause for a color-vision defect in all 128 dichromats. This indicates that the major component of color-vision deficiency could be attributed to alterations of the pigment genes or their regulatory regions in all cases, and the variety of gene arrangements associated with dichromacy is cataloged here. However, a fraction of the dichromats (17 out of 128; 13%) had genes predicted to encode pigments that would result in two populations of cones with different spectral sensitivities. Nine of the 17 were predicted to have two pigments with slightly different spectral peaks (usually≤2.5 nm) and eight had genes which specified pigments identical in peak absorption, but different in amino acid positions previously associated with optical density differences. In other subjects, reported previously, the same small spectral differences were associated with anomalous trichromacy rather than dichromacy. It appears that when the spectral difference specified by the genes is very small, the amount of residual red-green color vision measured varies; some individuals test as dichromats, others test as anomalous trichromats. The discrepancy is probably partly attributable to testing method differences and partly to a difference in performance not perception, but it seems there must also be cases in which other factors, for example, cone ratio, contribute to a person's ability to extract a color signal from a small spectral difference. PMID:15518190

Raman signatures of the modern pigment (Zn,Cd)S1-xSex and glass matrix of a red bead from Magoro Hill, an archaeological site in Limpopo Province, South Africa, recalibrate the settlement chronology

NASA Astrophysics Data System (ADS)

Prinsloo, Linda C.; Boeyens, Jan C. A.; van der Ryst, Maria M.; Webb, Geoffrey

2012-09-01

Two glass trade beads, one red and one yellow, retrieved from a secure archaeological context on Magoro Hill, an erstwhile Venda stronghold in South Africa's Limpopo Province, were analyzed with Raman and photoluminescence spectroscopy. Raman spectroscopy identified the pigment coloring the yellow bead as lead tin yellow Type II and the glass as a typical soda-lime-silica glass. Both pigments and glass type were in use over a long time span and therefore the bead cannot be used as a temporal marker. The pigment coloring the red bead, on the other hand, was identified as nano-(Zn,Cd)S1-xSex mixed crystals, a pigment that was only widely used in the early 20th century. This date casts doubt on local oral tradition that associates the brick-built structure from which the beads were recovered with Manzinzinzi, a Venda chief who, according to contemporary documentary accounts, had already passed away in the 1880s. The more recent date for the red bead resolves the apparent discord between the oral and written records, suggesting that the building was probably erected and/or occupied by one of Manzinzinzi's successors.

Aspartate Decarboxylase is Required for a Normal Pupa Pigmentation Pattern in the Silkworm, Bombyx mori.

PubMed

Dai, Fangyin; Qiao, Liang; Cao, Cun; Liu, Xiaofan; Tong, Xiaoling; He, Songzhen; Hu, Hai; Zhang, Li; Wu, Songyuan; Tan, Duan; Xiang, Zhonghuai; Lu, Cheng

2015-06-16

The pigmentation pattern of Lepidoptera varies greatly in different development stages. To date, the effects of key genes in the melanin metabolism pathway on larval and adult body color are distinct, yet the effects on pupal pigmentation remains unclear. In the silkworm, Bombyx mori, the black pupa (bp) mutant is only specifically melanized at the pupal stage. Using positional cloning, we found that a mutation in the Aspartate decarboxylase gene (BmADC) is causative in the bp mutant. In the bp mutant, a SINE-like transposon with a length of 493 bp was detected ~2.2 kb upstream of the transcriptional start site of BmADC. This insertion causes a sharp reduction in BmADC transcript levels in bp mutants, leading to deficiency of β-alanine and N-β-alanyl dopamine (NBAD), but accumulation of dopamine. Following injection of β-alanine into bp mutants, the color pattern was reverted that of the wild-type silkworms. Additionally, melanic pupae resulting from knock-down of BmADC in the wild-type strain were obtained. These findings show that BmADC plays a crucial role in melanin metabolism and in the pigmentation pattern of the silkworm pupal stage. Finally, this study contributes to a better understanding of pupa pigmentation patterns in Lepidoptera.

Aspartate Decarboxylase is Required for a Normal Pupa Pigmentation Pattern in the Silkworm, Bombyx mori

PubMed Central

Dai, Fangyin; Qiao, Liang; Cao, Cun; Liu, Xiaofan; Tong, Xiaoling; He, Songzhen; Hu, Hai; Zhang, Li; Wu, Songyuan; Tan, Duan; Xiang, Zhonghuai; Lu, Cheng

2015-01-01

The pigmentation pattern of Lepidoptera varies greatly in different development stages. To date, the effects of key genes in the melanin metabolism pathway on larval and adult body color are distinct, yet the effects on pupal pigmentation remains unclear. In the silkworm, Bombyx mori, the black pupa (bp) mutant is only specifically melanized at the pupal stage. Using positional cloning, we found that a mutation in the Aspartate decarboxylase gene (BmADC) is causative in the bp mutant. In the bp mutant, a SINE-like transposon with a length of 493 bp was detected ~2.2 kb upstream of the transcriptional start site of BmADC. This insertion causes a sharp reduction in BmADC transcript levels in bp mutants, leading to deficiency of β-alanine and N-β-alanyl dopamine (NBAD), but accumulation of dopamine. Following injection of β-alanine into bp mutants, the color pattern was reverted that of the wild-type silkworms. Additionally, melanic pupae resulting from knock-down of BmADC in the wild-type strain were obtained. These findings show that BmADC plays a crucial role in melanin metabolism and in the pigmentation pattern of the silkworm pupal stage. Finally, this study contributes to a better understanding of pupa pigmentation patterns in Lepidoptera. PMID:26077025

Electrofluidic systems for contrast management

NASA Astrophysics Data System (ADS)

Rebello, Keith J.; Maranchi, Jeffrey P.; Tiffany, Jason E.; Brown, Christopher Y.; Maisano, Adam J.; Hagedon, Matthew A.; Heikenfeld, Jason C.

2012-06-01

Operating in dynamic lighting conditions and in greatly varying backgrounds is challenging. Current paints and state-ofthe- art passive adaptive coatings (e.g. photochromics) are not suitable for multi- environment situations. A semi-active, low power, skin is needed that can adapt its reflective properties based on the background environment to minimize contrast through the development and incorporation of suitable pigment materials. Electrofluidic skins are a reflective display technology for electronic ink and paper applications. The technology is similar to that in E Ink but makes use of MEMS based microfluidic structures, instead of simple black and white ink microcapsules dispersed in clear oil. Electrofluidic skin's low power operation and fast switching speeds (~20 ms) are an improvement over current state-ofthe- art contrast management technologies. We report on a microfluidic display which utilizes diffuse pigment dispersion inks to change the contrast of the underlying substrate from 5.8% to 100%. Voltage is applied and an electromechanical pressure is used to pull a pigment dispersion based ink from a hydrophobic coated reservoir into a hydrophobic coated surface channel. When no voltage is applied, the Young-Laplace pressure pushes the pigment dispersion ink back down into the reservoir. This allows the pixel to switch from the on and off state by balancing the two pressures. Taking a systems engineering approach from the beginning of development has enabled the technology to be integrated into larger systems.

Permanent transparent color-warming glazes for dimmable and non-dimmable LED bulbs

NASA Astrophysics Data System (ADS)

Spanard, Jan-Marie A.

2014-02-01

Illuminant metameric failure is frequently experienced when viewing material samples under LED generated light vs. traditional incandescent light. LED light temperatures can be improved with phosphor coatings, but long-wave red light is still generally absent in LED "warm-white" light, resulting in metameric failure of orange-to-red objects. Drawing on techniques developed for the architectural restoration of stained glass, we find that transparent, heat-resistant, permanent, pigmented coatings can be applied to any glass, aluminum or plastic surface of an LED bulb, including the phosphor plate, dome or envelope, to produce warmer visible light than in current warm-light LED bulbs. These glazes can be applied in combination with existing technologies to better tune the LED emitted light or they may be used alone. These pigmented coatings include, but are not limited to, those made by suspending inorganic materials in potassium silicates or durable transparent pigmented resins. The pigmented resin glazes may be produced in either a clear gloss vehicle or an iridescent, light diffusing transparent base. Further, a graduated density of the tinted glazes on dimmable bulbs allow the light to change color as wattage is diminished. The glazes may be applied in the manufacturing of the bulb or marketed to current bulb owners as an after-market product to better tune the thousands of LED light bulbs currently in use.

A novel PAX3 mutation in a Japanese boy with Waardenburg syndrome type 1.

PubMed

Yoshida, Yu; Doi, Rieko; Adachi, Kaori; Nanba, Eiji; Kodani, Isamu; Ryoke, Kazuo

2016-01-01

Waardenburg syndrome type 1 (WS1) is a rare autosomal dominant disorder characterized by hair hypopigmentation, abnormal iris pigmentation, and congenital hearing loss. WS1 is caused by mutations in paired box gene 3 (PAX3). We identified a novel PAX3 mutation (c.1107 C>G, p.Ser369Arg) in a Japanese WS1 patient showing abnormal right iris pigmentation, right-sided congenital hearing loss, synophrys, incomplete left cleft lip, and cryptorchidism.

A novel PAX3 mutation in a Japanese boy with Waardenburg syndrome type 1

PubMed Central

Yoshida, Yu; Doi, Rieko; Adachi, Kaori; Nanba, Eiji; Kodani, Isamu; Ryoke, Kazuo

2016-01-01

Waardenburg syndrome type 1 (WS1) is a rare autosomal dominant disorder characterized by hair hypopigmentation, abnormal iris pigmentation, and congenital hearing loss. WS1 is caused by mutations in paired box gene 3 (PAX3). We identified a novel PAX3 mutation (c.1107 C>G, p.Ser369Arg) in a Japanese WS1 patient showing abnormal right iris pigmentation, right-sided congenital hearing loss, synophrys, incomplete left cleft lip, and cryptorchidism. PMID:27081571

Color of Cultures of Staphylococcus epidermidis Determined by Spectral Reflectance Colorimetry

PubMed Central

Brown, Richard W.

1966-01-01

Brown, Richard W. (National Animal Disease Laboratory, Ames, Iowa). Color of cultures of Staphylococcus epidermidis determined by spectral reflectance colorimetry. J. Bacteriol. 91:911–918. 1966.—A colorimeter with a reflectance attachment was used to study pigment production by Staphylococcus epidermidis strains grown on a medium containing Trypticase Soy Agar (BBL) and cream. The color of each culture was first characterized by reflectance colorimetry for dominant wavelength, purity, and luminous reflectance (Y) and was then classified visually into 1 of 10 color grades. There was not complete agreement in grading colors by the two methods, inasmuch as cultures that were considered more pigmented in relation to other cultures by the reflectance method were sometimes graded visually as less pigmented, and vice versa. Nevertheless, when the cultures were visually graded as being more pigmented, there was a concomitant increase in the average values of dominant wavelength and purity with a decrease in Y for the cultures in each higher grade. Thus, the nonpigmented cultures had the lowest dominant wavelength and purity values but the highest Y (brightness) values, whereas the most pigmented cultures had the highest dominant wavelength and purity values, but the lowest Y values. These results indicated that the cultures did not produce pigments of different hues (greenish-yellow, yellow, yellowish-orange) each with high, medium, and low degrees of purity and brightness. The value (1 − z), where the chromaticity coordinate z = Z/(X + Y + Z), was found to be proportional to the purity value. An inverse relationship between the tristimulus Z and purity values was also demonstrated. All cultures tested by the reflectance method were also classified according to the type of spectral absorption curve obtained with pigments extracted from the cultures with methanol. A comparison of these methods indicated that determining the type of spectral absorption curve would be better for differentiating strains of S. epidermidis, whereas the use of the reflectance method would be better for determining differences of pigment production within strains. PMID:5932106

Isolation and characterization of melanin pigment from yesso scallop Patinopecten yessoensis

NASA Astrophysics Data System (ADS)

Sun, Xiujun; Wu, Biao; Zhou, Liqing; Liu, Zhihong; Dong, Yinghui; Yang, Aiguo

2017-04-01

Melanin is one of the essential compounds in the pigments of molluscan shells. However, the effects of melanin on color variations in molluscs are largely unknown. Our previous study suggests that Yesso scallop Patinopecten yessoensis might contain melanin pigment in the dark brown shell. We therefore isolated melanin from the pigmented shells using hydrochloric acid method, and characterized the types of melanin pigments by spectrophotometry. The purified melanin, which was verified by spectrophotometry scanning and HPLC analysis, showed the typical characteristics of melanin absorption spectra and HPLC chromatograms. The contents of pheomelanin and eumelanin in pigmented shells, which were determined by the linear standard curve of melanin at 405 nm and 350 nm absorbance, were 48.23 ± 1.350 and 157.65 ± 5.905 mg, respectively. The present results indicate that the brown-pigmented shells of scallops comprise approximately 76.6% of eumelanin and 23.4% of pheomelanin, which supports the presence of eumelanin-rich pigment in scallop shells. Therefore, the combination of hydrochloric acid extraction and spectrophotometric quantification is a rapid and efficient method to isolate and quantify melanin in shells. This will facilitate the melanin studies related to shell color polymorphism and the selective breeding of bivalves with different shell colors.

Linkage and Segregation Analysis of Black and Brindle Coat Color in Domestic Dogs

PubMed Central

Kerns, Julie A.; Cargill, Edward J.; Clark, Leigh Anne; Candille, Sophie I.; Berryere, Tom G.; Olivier, Michael; Lust, George; Todhunter, Rory J.; Schmutz, Sheila M.; Murphy, Keith E.; Barsh, Gregory S.

2007-01-01

Mutations of pigment type switching have provided basic insight into melanocortin physiology and evolutionary adaptation. In all vertebrates that have been studied to date, two key genes, Agouti and Melanocortin 1 receptor (Mc1r), encode a ligand-receptor system that controls the switch between synthesis of red–yellow pheomelanin vs. black–brown eumelanin. However, in domestic dogs, historical studies based on pedigree and segregation analysis have suggested that the pigment type-switching system is more complicated and fundamentally different from other mammals. Using a genomewide linkage scan on a Labrador × greyhound cross segregating for black, yellow, and brindle coat colors, we demonstrate that pigment type switching is controlled by an additional gene, the K locus. Our results reveal three alleles with a dominance order of black (KB) > brindle (kbr) > yellow (ky), whose genetic map position on dog chromosome 16 is distinct from the predicted location of other pigmentation genes. Interaction studies reveal that Mc1r is epistatic to variation at Agouti or K and that the epistatic relationship between Agouti and K depends on the alleles being tested. These findings suggest a molecular model for a new component of the melanocortin signaling pathway and reveal how coat-color patterns and pigmentary diversity have been shaped by recent selection. PMID:17483404

A comparative study on starch digestibility, glycemic index and resistant starch of pigmented ('Njavara' and 'Jyothi') and a non-pigmented ('IR 64') rice varieties.

PubMed

Deepa, G; Singh, Vasudeva; Naidu, K Akhilender

2010-12-01

In vitro starch digestibility and glycemic indices of three rice varieties- 'Njavara', 'Jyothi' (pigmented rice verities) and 'IR 64' (non-pigmented rice) with similar amylose content were studied. Starch digestibility studies showed differences in glycemic response in three types of rice. The rate of starch hydrolysis was maximum (67.3%) in 'Njavara' rice compared to other two rice varieties. 'Njavara' exhibited the lowest kinetic constant (k) indicating inherent resistance to enzymatic hydrolysis. The glycemic load (GL) and glycemic index (GI) of 'Njavara' were similar to 'Jyothi' and 'IR 64'. Resistant starch content was high in pigmented rice varieties compared to 'IR 64'. The resistant starch content of dehusked and cooked rice increased with the storage time at refrigeration temperature (4°C). 'Njavara' is an easily digestible rice and can be used for baby and geriatric foods.

[Distribution Characteristics of Sedimentary Pigments in the Changjiang Estuary and Zhe-Min Coast and its Implications].

PubMed

Li, Dong; Yao, Peng; Zhao, Bin; Wang, Jin-peng; Pan, Hui-hui

2015-08-01

Compositions and contents of sedimentary pigments were examined using high performance liquid chromatography in order to discuss the spatial distributions of phytoplankton primary production, phytoplankton functional type and the preservation efficiency of phytoplankton pigments and their influencing factors. The results showed that: chloropigments [Chlorins, including chlorophyll-a (Chl-a) and pheopigments (Pheo-a), such as pheophytin-a (PHtin-a), pheophorbide-a (PHide-a), pPheophytin-a (pPHtin-a), sterol chlorin esters (SCEs) and carotenol chlorin esters (CCEs)] were the major type of sedimentary pigments. The nutrients inputs from Changjiang Diluted Water and upwelling in the Zhe-Min coastal mud area were the major cause for the patchy distribution with high sedimentary chloropigment contents. Carotenoid contents showed no trending changes and exhibited high values in the Changjiang Estuary and Zhe-Min Coasts. Based on the relative proportions of each diagnostic carotenoid to the total diagnostic carotenoids in the sediments, the relative contributions of diatoms, dinoflagellates, prymnesiophytes, prasinophytes, cryptophytes and cyanobacterias in the phytoplankton fuctional types were 48.8% +/- 17.4%, 10.7% +/- 11.5%, 8.1% +/- 7.2%, 18.6% +/- 8.2%, 9.4% +/- 6.4% and 4.3% +/- 3.2%, respectively. The preference for external environmental conditions (e.g., nutrient level and water salinity) was the main cause for the decreasing trends of diatoms and dinoflagellates proportions and the increasing trends of prasinophytes, cryptophytes and cyanobacterias seawards. Based on the spatial distribution of Chl-a/Pheo-a ratios, the higher preservation efficiencies of sedimentary pigments in the coastal regions (e.g., outer edge of maximum turbidity zone in the Changjiang Estuary, mouth of the Hangzhou Bay and upwelling region in the Zhe-Min Coast) were mainly due to the higher sedimentation rate and seasonal occurrences of hypoxia in bottom water, and these regions with higher sedimentary pigment preservation efficiencies were probably ideal areas for the marine eco-environmental evolutions. The bad sedimentary environment caused by the water exchange inside and outside of Hangzhou Bay was the dominant reason for the low sedimentary pigment contents and preservation efficiencies in this region.

Pigmented-MDCK (P-MDCK) Cell Line with Tunable Melanin Expression: An In Vitro Model for the Outer Blood-Retinal-Barrier

PubMed Central

Kadam, Rajendra S.; Scheinman, Robert. I.; Kompella, Uday B.

2013-01-01

Purpose Retinal pigment epithelium, which forms the outer blood-retinal-barrier, is a critical barrier for transport of drugs to the retina. The purpose of this study was to develop a pigmented MDCK (P-MDCK) cell line as a rapidly established in vitro model for the outer blood-retinal-barrier to assess the influence of melanin pigment on solute permeability. Methods A melanin synthesizing P-MDCK cell line was developed by lentiviral transduction of human tyrosinase and p-protein genes in MDCK (NBL-2) cells. Melanin content, tyrosinase activity (conversion of L-dopa to dopachrome), and transepithelial electrical resistance (TEER) were measured. Expression of tyrosinase protein and p-protein in P-MDCK cells was confirmed by confocal microscopy. Effect of L-tyrosine (0 to 2 mM) in culture medium on melanin synthesis in P-MDCK cells was evaluated. Cell uptake and transepithelial transport of pigment-binding chloroquine (Log D = 1.59) and a negative control salicylic acid (Log D = −1.14) were investigated. Results P-MDCK cells expressed tyrosinase and p-protein. Tyrosinase activity was 4.5 fold higher in P-MDCK cells as compared to wild-type MDCK cells. The transepithelial electrical resistance stabilized by day 4 in both cell types, with the TEER being 871 ± 30 and 876 ± 53 Ω.cm2 for P-MDCK and wild-type cells, respectively. Melanin content in P-MDCK cells depended on the concentration of L-tyrosine in culture medium, and increased from 3 to 54 µg/mg protein with an increase in L-tyrosine content from 0 to 2 mM. When the cells were grown in 2 mM L-tyrosine, uptake of chloroquine was 2.3 fold higher and the transepithelial transport was 2.2 fold lower in P-MDCK cells when compared to wild-type MDCK cells. No significant difference was observed for both cell uptake and transport of salicylic acid. Conclusions We developed a P-MDCK cell line with tunable melanin synthesis as a rapidly developing surrogate for retinal pigment epithelium. PMID:23003570

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.

Ethnic variation in melanin content and composition in photoexposed and photoprotected human skin.

PubMed

Alaluf, Simon; Atkins, Derek; Barrett, Karen; Blount, Margaret; Carter, Nik; Heath, Alan

2002-04-01

We have examined the quantity and composition of melanin in both photoprotected (volar upper arm) and chronically photoexposed (dorsal forearm) skin from a range of different ethnic skin types including African, Indian, Mexican, Chinese and European. The most lightly pigmented (European, Chinese and Mexican) skin types have approximately half as much epidermal melanin as the most darkly pigmented (African and Indian) skin types. However, the composition of melanin in these lighter skin types is comparatively more enriched with lightly coloured, alkali-soluble melanin components (up to three-fold). Regardless of ethnicity, epidermal melanin content is significantly greater in chronically photoexposed skin than it is in corresponding photoprotected skin (up to two-fold). However, by comparison there is only a modest enrichment of lightly coloured, alkali soluble melanin components in photoprotected skin (up to 1.3-fold). Analysis of melanosomes extracted from the epidermis in these subjects indicates that the proportion of spheroidal melanosomes is low in all skin types examined (<10%). This suggests that in human skin, pheomelanin is a very minor component of epidermal melanin, even in the lightest (European) skin types. Analysis of melanosome size revealed a significant and progressive variation in size with ethnicity: African skin having the largest melanosomes followed in turn by Indian, Mexican, Chinese and European. On the basis of these findings, we propose that variation in skin pigmentation is strongly influenced by both the amount and the composition (or colour) of the melanin in the epidermis. Variation in melanosome size may also play a significant role. However, the data also suggest that in human skin there are subtle differences in the mechanisms associated with the maintenance of constitutive pigmentation and facultative hyperpigmentation, respectively.

Light-induced vegetative anthocyanin pigmentation in Petunia

PubMed Central

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×(Petunia axillaris×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 (Amax). 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. PMID:19380423

Some biological activities of pigments extracted from Micrococcus roseus (PTCC 1411) and Rhodotorula glutinis (PTCC 5257).

PubMed

Rostami, Hossein; Hamedi, Hassan; Yolmeh, Mahmoud

2016-12-01

The importance of replacing synthetic pigments with natural types is increasing day by day in the food industry due to the harmful effects of some synthetic pigments. Microorganisms are a major source of natural pigments, which nowadays have attracted the attention of researchers. In this study, carotenoid pigments were produced by Micrococcus roseus and Rhodotorula glutinis, and some of their biological properties such as antimicrobial, antioxidant, anticancer, and anti-inflammatory activities were evaluated. Given the results, bacteria, especially gram-positive bacteria, had higher sensitivity to the pigments extracted from M. roseus (PEM) and R. glutinis (PER) compared to molds so that Bacillus cereus and Alternaria citri had the highest and the lowest sensitivity, respectively. PER showed a higher antioxidant activity compared with PEM in the various methods of measuring antioxidant activity. In vitro and in vivo anti-tumor-promoting activities of PER were measured significantly more than PEM (P <0.05). Both pigment extracts remarkably inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, so that ID 50 (50% inhibitory dose) of PEM and PER were 0.22 and 0.09 mg/ear, respectively. © The Author(s) 2016.

Some biological activities of pigments extracted from Micrococcus roseus (PTCC 1411) and Rhodotorula glutinis (PTCC 5257)

PubMed Central

Rostami, Hossein; Hamedi, Hassan; Yolmeh, Mahmoud

2016-01-01

The importance of replacing synthetic pigments with natural types is increasing day by day in the food industry due to the harmful effects of some synthetic pigments. Microorganisms are a major source of natural pigments, which nowadays have attracted the attention of researchers. In this study, carotenoid pigments were produced by Micrococcus roseus and Rhodotorula glutinis, and some of their biological properties such as antimicrobial, antioxidant, anticancer, and anti-inflammatory activities were evaluated. Given the results, bacteria, especially gram-positive bacteria, had higher sensitivity to the pigments extracted from M. roseus (PEM) and R. glutinis (PER) compared to molds so that Bacillus cereus and Alternaria citri had the highest and the lowest sensitivity, respectively. PER showed a higher antioxidant activity compared with PEM in the various methods of measuring antioxidant activity. In vitro and in vivo anti-tumor-promoting activities of PER were measured significantly more than PEM (P <0.05). Both pigment extracts remarkably inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, so that ID50 (50% inhibitory dose) of PEM and PER were 0.22 and 0.09 mg/ear, respectively. PMID:27895288

Porphyromonas gingivalis and related bacteria: from colonial pigmentation to the type IX secretion system and gliding motility

PubMed Central

Nakayama, K

2015-01-01

Porphyromonas gingivalis is a gram-negative, non-motile, anaerobic bacterium implicated as a major pathogen in periodontal disease. P. gingivalis grows as black-pigmented colonies on blood agar, and many bacteriologists have shown interest in this property. Studies of colonial pigmentation have revealed a number of important findings, including an association with the highly active extracellular and surface proteinases called gingipains that are found in P. gingivalis. The Por secretion system, a novel type IX secretion system (T9SS), has been implicated in gingipain secretion in studies using non-pigmented mutants. In addition, many potent virulence proteins, including the metallocarboxypeptidase CPG70, 35 kDa hemin-binding protein HBP35, peptidylarginine deiminase PAD and Lys-specific serine endopeptidase PepK, are secreted through the T9SS. These findings have not been limited to P. gingivalis but have been extended to other bacteria belonging to the phylum Bacteroidetes. Many Bacteroidetes species possess the T9SS, which is associated with gliding motility for some of these bacteria. PMID:25546073

β-Catenin activity in the dermal papilla of the hair follicle regulates pigment-type switching

PubMed Central

Enshell-Seijffers, David; Lindon, Catherine; Wu, Eleanor; Taketo, Makoto M.; Morgan, Bruce A.

2010-01-01

The switch between black and yellow pigment is mediated by the interaction between Melanocortin receptor 1 (Mc1r) and its antagonist Agouti, but the genetic and developmental mechanisms that modify this interaction to obtain different coat color in distinct environments are poorly understood. Here, the role of Wnt/β-catenin signaling in the regulation of pigment-type switching was studied. Loss and gain of function of β-catenin in the dermal papilla (DP) of the hair follicle results in yellow and black animals, respectively. β-Catenin activity in the DP suppresses Agouti expression and activates Corin, a negative regulator of Agouti activity. In addition, β-catenin activity in the DP regulates melanocyte activity by a mechanism that is independent of both Agouti and Corin. The coordinate and inverse regulation of Agouti and Corin renders pelage pigmentation sensitive to changes in β-catenin activity in the DP that do not alter pelage structure. As a result, the signals that specify two biologically distinct quantitative traits are partially uncoupled despite their common regulation by the β-catenin pathway in the same cells. PMID:21098273

Update on pigment dispersion syndrome and pigmentary glaucoma.

PubMed

Okafor, Kingsley; Vinod, Kateki; Gedde, Steven J

2017-03-01

The present article reviews the clinical features and pathogenesis of pigment dispersion syndrome and pigmentary glaucoma and provides an update regarding their diagnosis and management. Newer imaging modalities including ultrasound biomicroscopy and anterior segment optical coherence tomography facilitate visualization of the iris concavity characteristic of eyes with pigment dispersion syndrome and pigmentary glaucoma. Patients with pigmentary glaucoma may be distinguished from those with other glaucoma types by the presence of typical symptoms, personality type, and patterns of diurnal intraocular pressure fluctuation. Although laser iridotomy has been shown to alter iris anatomy in pigmentary glaucoma, it is not proven to slow visual field progression. Multiple trials have validated the safety and efficacy of filtering surgery in treating pigmentary glaucoma, with fewer studies published on the role of micro-invasive glaucoma surgery. Literature from the review period has further defined the unique clinical characteristics of pigment dispersion syndrome and pigmentary glaucoma. Laser surgery has a limited role in the management of these entities, whereas trabeculectomy remains an acceptable first-line surgical treatment. Further studies are needed to define the potential application of the newer micro-invasive glaucoma procedures in pigmentary glaucoma.

Spatial frequency domain spectroscopy of two layer media

NASA Astrophysics Data System (ADS)

Yudovsky, Dmitry; Durkin, Anthony J.

2011-10-01

Monitoring of tissue blood volume and oxygen saturation using biomedical optics techniques has the potential to inform the assessment of tissue health, healing, and dysfunction. These quantities are typically estimated from the contribution of oxyhemoglobin and deoxyhemoglobin to the absorption spectrum of the dermis. However, estimation of blood related absorption in superficial tissue such as the skin can be confounded by the strong absorption of melanin in the epidermis. Furthermore, epidermal thickness and pigmentation varies with anatomic location, race, gender, and degree of disease progression. This study describes a technique for decoupling the effect of melanin absorption in the epidermis from blood absorption in the dermis for a large range of skin types and thicknesses. An artificial neural network was used to map input optical properties to spatial frequency domain diffuse reflectance of two layer media. Then, iterative fitting was used to determine the optical properties from simulated spatial frequency domain diffuse reflectance. Additionally, an artificial neural network was trained to directly map spatial frequency domain reflectance to sets of optical properties of a two layer medium, thus bypassing the need for iteration. In both cases, the optical thickness of the epidermis and absorption and reduced scattering coefficients of the dermis were determined independently. The accuracy and efficiency of the iterative fitting approach was compared with the direct neural network inversion.

Aqueous biphasic systems formed by deep eutectic solvent and new-type salts for the high-performance extraction of pigments.

PubMed

Zhang, Hongmei; Wang, Yuzhi; Zhou, Yigang; Chen, Jing; Wei, Xiaoxiao; Xu, Panli

2018-05-01

Deep eutectic solvent (DES) composed of polypropylene glycol 400 (PPG 400) and tetrabutylammonium bromide (TBAB) was combined with a series of new-type salts such as quaternary ammonium salts, amino acid and polyols to form Aqueous Biphasic Systems (ABSs). Phase-forming ability of the salts was investigated firstly. The results showed that polyols had a relatively weak power to produce phases within studied scopes. And the shorter of carbon chain length of salts, the easier to obtain phase-splitting. Then partitioning of three pigments in PPG 400/betaine-based ABSs was addressed to investigate the effect of pigments' hydrophobicity on extraction efficiency. It was found that an increase in hydrophobicity contributed to the migration of pigments in the DES-rich phase. On the other hand, with a decline in phase-forming ability of salts, the extraction efficiency of the whole systems started to go down gradually. Based on the results, selective separation experiment was conducted successfully in the PPG 400/betaine-based systems, including more than 93.00% Sudan Ⅲ in the top phase and about 80.00% sunset yellow FCF/amaranth in the bottom phase. Additionally, ABSs constructed by DES/betaine for partitioning amaranth were further utilized to explore the performances of influence factors and back extraction. It can be concluded that after the optimization above 98.00% amaranth was transferred into the top phase. And 67.98% amaranth can be transferred into the bottom phase in back-extraction experiment. At last, dynamic light scattering (DLS) and transmission electron microscope (TEM) were applied to probe into extraction mechanism. The results demonstrated that hydrophobicity played an important role in the separation process of pigments. Through combining with new-type DES, this work was devoted to introducing plentiful salts as novel compositions of ABSs and providing an eco-friendly extraction way for partitioning pigments, which boosted development of ABSs in the monitoring food safety field. Copyright © 2018 Elsevier B.V. All rights reserved.

Seasonal to Decadal-Scale Variability in Satellite Ocean Color and Sea Surface Temperature for the California Current System

NASA Technical Reports Server (NTRS)

Mitchell, B. Greg; Kahru, Mati; Marra, John (Technical Monitor)

2002-01-01

Support for this project was used to develop satellite ocean color and temperature indices (SOCTI) for the California Current System (CCS) using the historic record of CZCS West Coast Time Series (WCTS), OCTS, WiFS and AVHRR SST. The ocean color satellite data have been evaluated in relation to CalCOFI data sets for chlorophyll (CZCS) and ocean spectral reflectance and chlorophyll OCTS and SeaWiFS. New algorithms for the three missions have been implemented based on in-water algorithm data sets, or in the case of CZCS, by comparing retrieved pigments with ship-based observations. New algorithms for absorption coefficients, diffuse attenuation coefficients and primary production have also been evaluated. Satellite retrievals are being evaluated based on our large data set of pigments and optics from CalCOFI.

Dermatopathia pigmentosa reticularis: A rare reticulate pigmentary disorder

PubMed Central

Shanker, Vinay; Gupta, Mudita

2013-01-01

Dermatopathia pigmentosa reticularis is a rare ectodermal dysplasia with a triad of generalized reticulate hyperpigmentation, noncicatricial alopecia, and onychodystrophy. We report a case of a 21 year old woman who had generalized reticulate pigmentation, diffuse noncicatricial alopecia and onychodystrophy of finger and toe nails. Along with this triad she had palmoplantar keratoderma and poorly developed dermatoglyphics. There was no evidence of involvement of other ectodermally derived organ. PMID:23440032

Lysobacter enzymogenes uses two distinct cell-cell signaling systems for differential regulation of secondary-metabolite biosynthesis and colony morphology.

PubMed

Qian, Guoliang; Wang, Yulan; Liu, Yiru; Xu, Feifei; He, Ya-Wen; Du, Liangcheng; Venturi, Vittorio; Fan, Jiaqin; Hu, Baishi; Liu, Fengquan

2013-11-01

Lysobacter enzymogenes is a ubiquitous environmental bacterium that is emerging as a potentially novel biological control agent and a new source of bioactive secondary metabolites, such as the heat-stable antifungal factor (HSAF) and photoprotective polyene pigments. Thus far, the regulatory mechanism(s) for biosynthesis of these bioactive secondary metabolites remains largely unknown in L. enzymogenes. In the present study, the diffusible signal factor (DSF) and diffusible factor (DF)-mediated cell-cell signaling systems were identified for the first time from L. enzymogenes. The results show that both Rpf/DSF and DF signaling systems played critical roles in modulating HSAF biosynthesis in L. enzymogenes. Rpf/DSF signaling and DF signaling played negative and positive effects in polyene pigment production, respectively, with DF playing a more important role in regulating this phenotype. Interestingly, only Rpf/DSF, but not the DF signaling system, regulated colony morphology of L. enzymgenes. Both Rpf/DSF and DF signaling systems were involved in the modulation of expression of genes with diverse functions in L. enzymogenes, and their own regulons exhibited only a few loci that were regulated by both systems. These findings unveil for the first time new roles of the Rpf/DSF and DF signaling systems in secondary metabolite biosynthesis of L. enzymogenes.

Lysobacter enzymogenes Uses Two Distinct Cell-Cell Signaling Systems for Differential Regulation of Secondary-Metabolite Biosynthesis and Colony Morphology

PubMed Central

Qian, Guoliang; Wang, Yulan; Liu, Yiru; Xu, Feifei; He, Ya-Wen; Du, Liangcheng; Venturi, Vittorio; Fan, Jiaqin; Hu, Baishi

2013-01-01

Lysobacter enzymogenes is a ubiquitous environmental bacterium that is emerging as a potentially novel biological control agent and a new source of bioactive secondary metabolites, such as the heat-stable antifungal factor (HSAF) and photoprotective polyene pigments. Thus far, the regulatory mechanism(s) for biosynthesis of these bioactive secondary metabolites remains largely unknown in L. enzymogenes. In the present study, the diffusible signal factor (DSF) and diffusible factor (DF)-mediated cell-cell signaling systems were identified for the first time from L. enzymogenes. The results show that both Rpf/DSF and DF signaling systems played critical roles in modulating HSAF biosynthesis in L. enzymogenes. Rpf/DSF signaling and DF signaling played negative and positive effects in polyene pigment production, respectively, with DF playing a more important role in regulating this phenotype. Interestingly, only Rpf/DSF, but not the DF signaling system, regulated colony morphology of L. enzymgenes. Both Rpf/DSF and DF signaling systems were involved in the modulation of expression of genes with diverse functions in L. enzymogenes, and their own regulons exhibited only a few loci that were regulated by both systems. These findings unveil for the first time new roles of the Rpf/DSF and DF signaling systems in secondary metabolite biosynthesis of L. enzymogenes. PMID:23974132

Smart options for simultaneous functionalization and pigment coloration of cellulosic/wool blends.

PubMed

Ibrahim, N A; Khalil, H M; El-Zairy, E M R; Abdalla, W A

2013-07-01

The present innovative research work deals with the individual use of chitosan (2.5 g/kg), Aloe vera (10 g/kg), triclosan (10 g/kg), TiO2-nanoparticles (TiO2-NP's, 10 g/kg), silicon micro-emulsion (20 g/kg) or a water/oil-repellent agent (40 g/kg) for modifying the pigment print paste to produce functionalized cotton/wool and viscose/wool pigment prints in one step process. The imparted functional properties such as antibacterial, antibacterial/UV-protection, soft-handle or water/oil-repellency together with the change in the printing properties were evaluated. Some of the obtained pigment prints were characterized by scanning electron microscope (SEM), and energy dispersive X-rays (EDX) to confirm deposition of certain functional additives on printed fabrics. The wide-range of imparted functional properties together with the depth of the obtained pigment prints were maintained over 80% even after 15 consecutive laundering cycles. The extent of retention in functional and pigment printing properties is influenced by the type of functional additive as well as the kind of substrate. Copyright © 2013 Elsevier Ltd. All rights reserved.

Portuguese tin-glazed earthenware from the 17th century. Part 1: Pigments and glazes characterization

NASA Astrophysics Data System (ADS)

Vieira Ferreira, L. F.; Casimiro, T. M.; Colomban, Ph.

2013-03-01

Two sherds representative of the Portuguese faience production of the first and second halves of the 17th century were studied carefully with the use of non-invasive spectroscopies, namely: Ground State Diffuse Reflectance Absorption (GSDR), micro-Raman, Fourier-Transform Infrared (FT-IR), Laser Induced Luminescence (LIL) and Proton Induced X-ray (PIXE). These results were compared with the ones obtained for a Chinese Ming porcelain, Wanli period (16th/beginning of the 17th centuries), which served as an influence for the initial Lisbon's faience production. By combining information of the different non-destructive spectroscopic techniques used in this work, it was possible to conclude that: Co3O4 (Co II and Co III) can be found in the silicate matrix and is the blue pigment in the "Especieiro" sample (1st half of the 17th C.). Cobalt olivine silicate (Co2SiO4, Co II only) was clearly identified as the blue pigment in "Aranhões" sample (2nd half of the17th C.) - 824 cm-1 band in the micro-Raman-spectrum. Cobalt aluminate (CoAl2O4, Co II only) is the blue pigment in the Wanli plate - 203 and 512 cm-1 bands in the micro-Raman spectrum. The blue pigment in the 1st half 17th century of Lisbon's production was obtained by addition of a cobalt ore in low concentrations, which gives no specific Raman signature, because of complete dissolution in the glass. However, in most cases of the 2nd half 17th century, the Raman signature was quite evident, from a cobalt silicate. These findings point to the use of higher temperature kilns in the second case.

Low VOC Barrier Coating for Industrial Maintenance

DTIC Science & Technology

2007-11-01

Color - VOC - Total Solids (wt) - Total Solids (volume) - Percent Pigment - Stormer Viscosity - Brookfield Viscosity - Pot Life...17 NTPEP LVBC Testing (R 31-02) ●Formula - Color - VOC - Total Solids (wt) - Total Solids (volume) - Percent Pigment - Stormer ...Consistency of Paints Measuring Krebs Unit (KU) Viscosity Using the Stormer -Type Viscometer D 610 Test Method for Evaluating Degree of

Pigmentation restored in mutant laboratory strain of the lady beetle Coleomegilla maculata through dietary supplementation

USDA-ARS?s Scientific Manuscript database

A laboratory colony of Coleomegilla maculata (DeGeer), ye, selected for a pigmentation deficiency, was restored to near wild type cuticle coloration by adding crushed heads and wings of the red colored parental strain to the diet. While the wings and other colored portions of the cuticle regained th...

Enhancement of the photoproperties of solid-state TiO2|dye|CuI cells by coupling of two dyes

NASA Astrophysics Data System (ADS)

Sirimanne, P. M.; Senevirathna, M. K. I.; Premalal, E. V. A.; Pitigala, P. K. D. D. P.

2006-06-01

The electronic coupling of a natural pigment extracted from pomegranate fruits (rich with cyanin and exist as flavylium at natural PH) with an organic dye mercurochrome enhanced the performance of solid-state TiO2|dye|CuI-type photovoltaic cells sensitized from pomegranate pigments or mercurochrome individually.

Phytoplankton Pigment Communities Can be Modeled Using Unique Relationships With Spectral Absorption Signatures in a Dynamic Coastal Environment

NASA Astrophysics Data System (ADS)

Catlett, D.; Siegel, D. A.

2018-01-01

Understanding the roles of phytoplankton community composition in the functioning of marine ecosystems and ocean biogeochemical cycles is important for many ocean science problems of societal relevance. Remote sensing currently offers the only feasible method for continuously assessing phytoplankton community structure on regional to global scales. However, methods are presently hindered by the limited spectral resolution of most satellite sensors and by uncertainties associated with deriving quantitative indices of phytoplankton community structure from phytoplankton pigment concentrations. Here we analyze a data set of concurrent phytoplankton pigment concentrations and phytoplankton absorption coefficient spectra from the Santa Barbara Channel, California, to develop novel optical oceanographic models for retrieving metrics of phytoplankton community composition. Cluster and Empirical Orthogonal Function analyses of phytoplankton pigment concentrations are used to define up to five phytoplankton pigment communities as a representation of phytoplankton functional types. Unique statistical relationships are found between phytoplankton pigment communities and absorption features isolated using spectral derivative analysis and are the basis of predictive models. Model performance is substantially better for phytoplankton pigment community indices compared with determinations of the contributions of individual pigments or taxa to chlorophyll a. These results highlight the application of data-driven chemotaxonomic approaches for developing and validating bio-optical algorithms and illustrate the potential and limitations for retrieving phytoplankton community composition from hyperspectral satellite ocean color observations.

Diffuse Mesangial Sclerosis in a Child With Dyskeratosis Congenita Leading to End-stage Renal Disease.

PubMed

Kamel, Abidi; Sayari, Taha; Jellouli, Manel; Hammi, Yousra; Louzir, Rim Ghoucha; Gargah, Tahar

2016-11-01

Dyskeratosis congenita (DC) is a very rare inherited disorder. It is caused by dysfunction of telomere maintenance. It involves RNA telomerase components relevant to various mutations leading to a classic triad of physical findings consisting of nail dystrophy of the hands and feet, mucosal leukoplakia, and reticular pigmentation of the skin, most commonly on the head, neck, and trunk. Bone marrow failure along with pulmonary complications and malignancies are all common causes of premature death in patients with DC as well as other abnormalities. We report a new case of DC with impure nephrotic syndrome relevant to histopathologic signs of a diffuse mesangial sclerosis, leading to an early end-stage renal disease. Challenges remain to understand the diverse spectrum of DC especially in children. To the best of our knowledge this is the first case of DC associated to diffuse mesangial sclerosis.

Hg diffusion in books of XVIII and XIX centuries by synchrotron microprobe

NASA Astrophysics Data System (ADS)

Pessanha, S.; Carvalho, M. L.; Manso, M.; Guilherme, A.; Marques, A. F.; Perez, C. A.

2009-08-01

The pigment vermilion (HgS) was used to color the fore edge, tail and head of books. Dissemination and quantification of Hg present in the ink used to color books from XVIII and XIX centuries are reported. Mercury is a very toxic element for the human body, therefore it is extremely important to know whether Hg tends to disseminate throughout the paper or stays confined to the borders of the books with less danger for readers. Synchrotron X-ray microprobe was used to evaluate Hg dissemination from the border to the centre of the paper sheet. The diffusion pattern of Hg was compared with the results obtained by a portable X-ray fluorescence spectrometer and mean quantitative calculations were obtained by a stationary X-ray fluorescence system with triaxial geometry. The results showed high concentrations of Hg in the external regions, but no diffusion was observed for the inner parts of the paper.

Phylogeography and pigment type diversity of Synechococcus cyanobacteria in surface waters of the northwestern pacific ocean.

PubMed

Xia, Xiaomin; Partensky, Frédéric; Garczarek, Laurence; Suzuki, Koji; Guo, Cui; Yan Cheung, Shun; Liu, Hongbin

2017-01-01

The widespread unicellular cyanobacteria Synechococcus are major contributors to global marine primary production. Here, we report their abundance, phylogenetic diversity (as assessed using the RNA polymerase gamma subunit gene rpoC1) and pigment diversity (as indirectly assessed using the laterally transferred cpeBA genes, encoding phycoerythrin-I) in surface waters of the northwestern Pacific Ocean, sampled over nine distinct cruises (2008-2015). Abundance of Synechococcus was low in the subarctic ocean and South China Sea, intermediate in the western subtropical Pacific Ocean, and the highest in the Japan and East China seas. Clades I and II were by far the most abundant Synechococcus lineages, the former dominating in temperate cold waters and the latter in (sub)tropical waters. Clades III and VI were also fairly abundant in warm waters, but with a narrower distribution than clade II. One type of chromatic acclimater (3dA) largely dominated the Synechococcus communities in the subarctic ocean, while another (3dB) and/or cells with a fixed high phycourobilin to phycoerythrobilin ratio (pigment type 3c) predominated at mid and low latitudes. Altogether, our results suggest that the variety of pigment content found in most Synechococcus clades considerably extends the niches that they can colonize and therefore the whole genus habitat. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Chlorophyll a/b-binding proteins, pigment conversions, and early light-induced proteins in a chlorophyll b-less barley mutant.

PubMed Central

Król, M; Spangfort, M D; Huner, N P; Oquist, G; Gustafsson, P; Jansson, S

1995-01-01

Monospecific polyclonal antibodies have been raised against synthetic peptides derived from the primary sequences from different plant light-harvesting Chl a/b-binding (LHC) proteins. Together with other monospecific antibodies, these were used to quantify the levels of the 10 different LHC proteins in wild-type and chlorina f2 barley (Hordeum vulgare L.), grown under normal and intermittent light (ImL). Chlorina f2, grown under normal light, lacked Lhcb1 (type I LHC II) and Lhcb6 (CP24) and had reduced amounts of Lhcb2, Lhcb3 (types II and III LHC II), and Lhcb4 (CP 29). Chlorina f2 grown under ImL lacked all LHC proteins, whereas wild-type ImL plants contained Lhcb5 (CP 26) and a small amount of Lhcb2. The chlorina f2 ImL thylakoids were organized in large parallel arrays, but wild-type ImL thylakoids had appressed regions, indicating a possible role for Lhcb5 in grana stacking. Chlorina f2 grown under ImL contained considerable amounts of violaxanthin (2-3/reaction center), representing a pool of phototransformable xanthophyll cycle pigments not associated with LHC proteins. Chlorina f2 and the plants grown under ImL also contained early light-induced proteins (ELIPs) as monitored by western blotting. The levels of both ELIPs and xanthophyll cycle pigments increased during a 1 h of high light treatment, without accumulation of LHC proteins. These data are consistent with the hypothesis that ELIPs are pigment-binding proteins, and we suggest that ELIPs bind photoconvertible xanthophylls and replace "normal" LHC proteins under conditions of light stress. PMID:7748263

The bacteriorhodopsin model membrane system as a prototype molecular computing element.

PubMed

Hong, F T

1986-01-01

The quest for more sophisticated integrated circuits to overcome the limitation of currently available silicon integrated circuits has led to the proposal of using biological molecules as computational elements by computer scientists and engineers. While the theoretical aspect of this possibility has been pursued by computer scientists, the research and development of experimental prototypes have not been pursued with an equal intensity. In this survey, we make an attempt to examine model membrane systems that incorporate the protein pigment bacteriorhodopsin which is found in Halobacterium halobium. This system was chosen for several reasons. The pigment/membrane system is sufficiently simple and stable for rigorous quantitative study, yet at the same time sufficiently complex in molecular structure to permit alteration of this structure in an attempt to manipulate the photosignal. Several methods of forming the pigment/membrane assembly are described and the potential application to biochip design is discussed. Experimental data using these membranes and measured by a tunable voltage clamp method are presented along with a theoretical analysis based on the Gouy-Chapman diffuse double layer theory to illustrate the usefulness of this approach. It is shown that detailed layouts of the pigment/membrane assembly as well as external loading conditions can modify the time course of the photosignal in a predictable manner. Some problems that may arise in the actual implementation and manufacturing, as well as the use of existing technology in protein chemistry, immunology, and recombinant DNA technology are discussed.

Visible and infrared reflectance imaging spectroscopy of paintings: pigment mapping and improved infrared reflectography

NASA Astrophysics Data System (ADS)

Delaney, John K.; Zeibel, Jason G.; Thoury, Mathieu; Littleton, Roy; Morales, Kathryn M.; Palmer, Michael; de la Rie, E. René

2009-07-01

Reflectance imaging spectroscopy, the collection of images in narrow spectral bands, has been developed for remote sensing of the Earth. In this paper we present findings on the use of imaging spectroscopy to identify and map artist pigments as well as to improve the visualization of preparatory sketches. Two novel hyperspectral cameras, one operating from the visible to near-infrared (VNIR) and the other in the shortwave infrared (SWIR), have been used to collect diffuse reflectance spectral image cubes on a variety of paintings. The resulting image cubes (VNIR 417 to 973 nm, 240 bands, and SWIR 970 to 1650 nm, 85 bands) were calibrated to reflectance and the resulting spectra compared with results from a fiber optics reflectance spectrometer (350 to 2500 nm). The results show good agreement between the spectra acquired with the hyperspectral cameras and those from the fiber reflectance spectrometer. For example, the primary blue pigments and their distribution in Picasso's Harlequin Musician (1924) are identified from the reflectance spectra and agree with results from X-ray fluorescence data and dispersed sample analysis. False color infrared reflectograms, obtained from the SWIR hyperspectral images, of extensively reworked paintings such as Picasso's The Tragedy (1903) are found to give improved visualization of changes made by the artist. These results show that including the NIR and SWIR spectral regions along with the visible provides for a more robust identification and mapping of artist pigments than using visible imaging spectroscopy alone.

Effects of type of light on mouse circadian behaviour and stress levels.

PubMed

Alves-Simoes, Marta; Coleman, Georgia; Canal, Maria Mercè

2016-02-01

Light is the principal synchronizing environmental factor for the biological clock. Light quantity (intensity), and light quality (type of light source) can have different effects. The aim of this study was to determine the effects of the type of light experienced from the time of birth on mouse growth, circadian behaviour and stress levels. We raised pigmented and albino mice under 24 h light-dark cycles of either fluorescent or white light-emitting diode (LED) light source during the suckling stage, and the animals were then exposed to various light environments after weaning and their growth rate, locomotor activity and plasma corticosterone concentration were measured. We found that the type of light the animals were exposed to did not affect the animals' growth rates or stress levels. However, we observed significant effects on the expression of the locomotor activity rhythm under low contrast light-dark cycles in pigmented mice, and under constant light in both albino and pigmented mice. These results highlight the importance of environmental light quality (light source) on circadian behavioural rhythms, and the need for close monitoring of light environments in animal facilities. © The Author(s) 2015.

Type 3 Neovascularization Associated with Retinitis Pigmentosa.

PubMed

Sayadi, Jihene; Miere, Alexandra; Souied, Eric H; Cohen, Salomon Y

2017-01-01

To report a case of type 3 neovascular lesion in a patient with retinitis pigmentosa (RP) complicated by macular edema. A 78-year-old man with a long follow-up for RP was referred for painless visual acuity decrease in the right eye. Best-corrected visual acuity was 20/125 in the right eye and 20/40 in the left. Fundus examination showed typical RP and macular edema in both eyes. In the right eye, spectral domain optical coherence tomography revealed a marked cystic macular edema associated with disruption of the Bruch membrane/retinal pigment epithelium complex overlying a pigmentary epithelium detachment, with a vascular structure which appeared to originate from the deep capillary plexus and to be connected with the subretinal pigment epithelium space. Optical coherence tomography angiography showed a high-flow vessel infiltrating the outer retinal layers in the deep capillary plexus segmentation, and a tuft-shaped, bright, high-flow network that seemed to be connected with the subretinal pigment epithelium space in the outer retinal layer segmentation. This presentation was consistent with an early type 3 neovascular lesion in the right eye. Type 3 neovascularization may be considered a possible complication of RP.

Rheumatic diseases presenting as sports-related injuries.

PubMed

Jennings, Fabio; Lambert, Elaine; Fredericson, Michael

2008-01-01

Most individuals seeking consultation at sports medicine clinics are young, healthy athletes with injuries related to a specific activity. However, these athletes may have other systemic pathologies, such as rheumatic diseases, that may initially mimic sports-related injuries. As rheumatic diseases often affect the musculoskeletal system, they may masquerade as traumatic or mechanical conditions. A systematic review of the literature found numerous case reports of athletes who presented with apparent mechanical low back pain, sciatica pain, hip pain, meniscal tear, ankle sprain, rotator cuff syndrome and stress fractures and who, on further investigation, were found to have manifestations of rheumatic diseases. Common systemic, inflammatory causes of these musculoskeletal complaints include ankylosing spondylitis (AS), gout, chondrocalcinosis, psoriatic enthesopathy and early rheumatoid arthritis (RA). Low back pain is often mechanical among athletes, but cases have been described where spondyloarthritis, especially AS, has been diagnosed. Neck pain, another common mechanical symptom in athletes, can be an atypical presentation of AS or early RA. Hip or groin pain is frequently related to injuries in the hip joint and its surrounding structures. However, differential diagnosis should be made with AS, RA, gout, psudeogout, and less often with haemochromatosis and synovial chondochromatosis. In athletes presenting with peripheral arthropathy, it is mandatory to investigate autoimmune arthritis (AS, RA, juvenile idiopathic arthritis and systemic lupus erythematosus), crystal-induced arthritis, Lyme disease and pigmented villonodular synovitis. Musculoskeletal soft tissue disorders (bursitis, tendinopathies, enthesitis and carpal tunnel syndrome) are a frequent cause of pain and disability in both competitive and recreational athletes, and are related to acute injuries or overuse. However, these disorders may occasionally be a manifestation of RA, spondyloarthritis, gout and pseudogout. Effective management of athletes presenting with musculoskeletal complaints requires a structured history, physical examination, and definitive diagnosis to distinguish soft tissue problems from joint problems and an inflammatory syndrome from a non-inflammatory syndrome. Clues to a systemic inflammatory aetiology may include constitutional symptoms, morning stiffness, elevated acute-phase reactants and progressive symptoms despite modification of physical activity. The mechanism of injury or lack thereof is also a clue to any underlying disease. In these circumstances, more complete workup is reasonable, including radiographs, magnetic resonance imaging and laboratory testing for autoantibodies.

Sex differences of hip morphology in young adults with hip pain and labral tears.

PubMed

Hetsroni, Iftach; Dela Torre, Katrina; Duke, Gavin; Lyman, Stephen; Kelly, Bryan T

2013-01-01

To compare hip morphology between young men and women who presented with hip pain and labral tears. A retrospective review of our hip arthroscopy registry from March 2008 to June 2010 was completed. We identified 217 patients (249 hips) who were between the ages of 18 to 30 years. The inclusion criteria were (1) insidious-onset hip pain or worsening pain after low-energy sports trauma, (2) positive hip impingement sign, (3) Tönnis grades 0 to 1, (4) magnetic resonance imaging showing labral tear, and (5) primary hip arthroscopy confirming labral tear. Forty-five patients (52 hips) were excluded for the following reasons: (1) revision hip arthroscopy, (2) high-energy hip trauma, (3) history of surgery involving the femur or pelvis, (4) previous fractures of the femur or pelvis, (5) Tönnis grades 2 or above, (6) proliferative disease of the hip (i.e., synovial chondromatosis, pigmented villonodular synovitis), (7) neuromuscular disease (i.e., cerebral palsy), and (8) deformities related to Legg-Calvé-Perthes disease or developmental dysplasia of the hip. Therefore, the cohort study group included 105 (61%) men (123 [62.4%] hips) and 67 (39%) women (74 [37.6%] hips). Sex comparisons were made for the following variables measured on preoperative hip computed tomography scans: alpha angle, acetabular version, femoral version, lateral center-edge angle, and neck-shaft angle. Women had smaller alpha angles (47.8°v 63.6°, P < .001), increased acetabular version (17.3°v 13.9°, P < .001), and increased femoral anteversion (14.4°v 12.1°, P = .05). In young adults with hip pain and labral tears, women have smaller alpha angles and hips that are generally more anteverted. Therefore, in women, cam lesions may be more subtle, preoperative hip version analyses should be encouraged, and rim trimming may need to be cautiously planned to avoid increasing contact stresses at weight-bearing areas after such a procedure. Level III, retrospective comparative study. Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Retinal network adaptation to bright light requires tyrosinase.

PubMed

Page-McCaw, Patrick S; Chung, S Clare; Muto, Akira; Roeser, Tobias; Staub, Wendy; Finger-Baier, Karin C; Korenbrot, Juan I; Baier, Herwig

2004-12-01

The visual system adjusts its sensitivity to a wide range of light intensities. We report here that mutation of the zebrafish sdy gene, which encodes tyrosinase, slows down the onset of adaptation to bright light. When fish larvae were challenged with periods of darkness during the day, the sdy mutants required nearly an hour to recover optokinetic behavior after return to bright light, whereas wild types recovered within minutes. This behavioral deficit was phenocopied in fully pigmented fish by inhibiting tyrosinase and thus does not depend on the absence of melanin pigment in sdy. Electroretinograms showed that the dark-adapted retinal network recovers sensitivity to a pulse of light more slowly in sdy mutants than in wild types. This failure is localized in the retinal neural network, postsynaptic to photoreceptors. We propose that retinal pigment epithelium (which normally expresses tyrosinase) secretes a modulatory factor, possibly L-DOPA, which regulates light adaptation in the retinal circuitry.

Fabrication of Multilayer-Type Mn-Si Thermoelectric Device

NASA Astrophysics Data System (ADS)

Kajitani, T.; Ueno, T.; Miyazaki, Y.; Hayashi, K.; Fujiwara, T.; Ihara, R.; Nakamura, T.; Takakura, M.

2014-06-01

This research aims to develop a direct-contact manganese silicon p/ n multilayer-type thermoelectric power generation block. p-type MnSi1.74 and n-type Mn0.7Fe0.3Si1.68 ball-milled powders with diameter of about 10 μm or less were mixed with polyvinyl butyl alcohol diluted with methylbenzene at pigment volume concentration of approximately 70%. The doctor-blade method produced 45- μm-thick p- and n-type pigment plates. The insulator, i.e., powdered glass, was mixed with cellulose to form insulator slurry. Lamination of manganese silicide pigment layers and screen-printed insulator layers was carried out to fabricate multilayer direct-contact thermoelectric devices. Hot pressing and spark plasma sintering were carried out at 450°C and 900°C, respectively. Four to 30 thermoelectric (TE) p/ n pairs were fabricated in a 10 mm × 10 mm × 10 mm sintered TE block. The maximum output was 11.7 mW/cm2 at a temperature difference between 20°C and 700°C, which was about 1/85 of the ideal power generation estimated from the thermoelectric data of the bulk MnSi1.74 and Mn0.7Fe0.3Si1.68 materials. A power generation test using an engine test bench was also carried out.

Glass promotes the differentiation of neuronal and non-neuronal cell types in the Drosophila eye

PubMed Central

Morrison, Carolyn A.; Chen, Hao; Cook, Tiffany; Brown, Stuart

2018-01-01

Transcriptional regulators can specify different cell types from a pool of equivalent progenitors by activating distinct developmental programs. The Glass transcription factor is expressed in all progenitors in the developing Drosophila eye, and is maintained in both neuronal and non-neuronal cell types. Glass is required for neuronal progenitors to differentiate as photoreceptors, but its role in non-neuronal cone and pigment cells is unknown. To determine whether Glass activity is limited to neuronal lineages, we compared the effects of misexpressing it in neuroblasts of the larval brain and in epithelial cells of the wing disc. Glass activated overlapping but distinct sets of genes in these neuronal and non-neuronal contexts, including markers of photoreceptors, cone cells and pigment cells. Coexpression of other transcription factors such as Pax2, Eyes absent, Lozenge and Escargot enabled Glass to induce additional genes characteristic of the non-neuronal cell types. Cell type-specific glass mutations generated in cone or pigment cells using somatic CRISPR revealed autonomous developmental defects, and expressing Glass specifically in these cells partially rescued glass mutant phenotypes. These results indicate that Glass is a determinant of organ identity that acts in both neuronal and non-neuronal cells to promote their differentiation into functional components of the eye. PMID:29324767

Encapsulating betalains from Opuntia ficus-indica fruits by ionic gelation: Pigment chemical stability during storage of beads.

PubMed

Otálora, María Carolina; Carriazo, José Gregorio; Iturriaga, Laura; Osorio, Coralia; Nazareno, Mónica Azucena

2016-07-01

Betalain encapsulation was performed by ionic gelation as a stabilization strategy for these natural pigments. Betalains were extracted from purple cactus fruits and encapsulated in calcium-alginate and in combination of calcium alginate and bovine serum albumin. Beads were characterised by scanning electron microscopy and thermal analysis using differential scanning calorimetry and thermogravimetry. Moisture sorption isotherms were determined. Bead morphology was affected by matrix composition. Pigments storage stability was evaluated at different equilibrium relative humidity and temperatures. Pigment composition of beads was determined by HPLC-MS-MS and degradation products were also analysed after storage; betalamic acid being the major one. Both types of matrices protected the encapsulated pigments, being their storage stability better at low relative humidity than that of the non-encapsulated control material. Antiradical activities of beads were proportional to remaining betalain contents. At high relative humidity, there was no protection and low storage stability was observed in the samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pigment organization in the photosynthetic apparatus of Roseiflexus castenholzii.

PubMed

Collins, Aaron M; Xin, Yueyong; Blankenship, Robert E

2009-08-01

The light-harvesting-reaction center (LHRC) complex from the chlorosome-lacking filamentous anoxygenic phototroph (FAP), Roseiflexus castenholzii (R. castenholzii) was purified and characterized for overall pigment organization. The LHRC is a single complex that is comprised of light harvesting (LH) and reaction center (RC) polypeptides as well as an attached c-type cytochrome. The dominant carotenoid found in the LHRC is keto-gamma-carotene, which transfers excitation to the long wavelength antenna band with 35% efficiency. Linear dichroism and fluorescence polarization measurements indicate that the long wavelength antenna pigments absorbing around 880 nm are perpendicular to the membrane plane, with the corresponding Q(y) transition dipoles in the plane of the membrane. The antenna pigments absorbing around 800 nm, as well as the bound carotenoid, are oriented at a large angle with respect to the membrane. The antenna pigments spectroscopically resemble the well-studied LH2 complex from purple bacteria, however the close association with the RC makes the light harvesting component of this complex functionally more like LH1.

The Role of Authigenic (pigment) Hematite in Controlling the Remanence, Rock Magnetic, and Magnetic Fabric Properties of Red Beds--If You Have Seen One Red Bed, You Certainly Have Not Seen Them All!

NASA Astrophysics Data System (ADS)

Geissman, J. W.

2014-12-01

Discussion continues on the relative role of authigenic (pigment) fine-grained hematite, relative to detrital, considerably coarser specular hematite (specularite) as a carrier of geologically meaningful remanence, as a determinant of rock magnetic properties, and as a contributor to magnetic fabrics in red beds. For one, many workers commonly assume that the laboratory unblocking temperature spectra (Tlub) of a red bed dominated by authigenic pigment does not reach the maximum Tlub as approximated by the Neel temperature (~948 K) because of the ultra fine grain size of the pigment. This issue was discussed as recently as the IRM Santa Fe meeting in late June, 2014. Many laboratories routinely utilize chemical demagnetization in concert with progressive thermal demagnetization to attempt to assess the relative role of pigment vs. detrital hematite. However, the utility of chemical demagnetization has been long challenged. In studying the anisotropy of magnetic susceptibility and remanence in red beds, recent work has considered separating the contributions of both types of hematite to the fabric signal. Three different red bed "types" (siltstones of the Triassic Chugwater Group, Gros Ventre Range, Wyoming; mudrocks of lowermost Triassic Quartermaster Formation, west Texas; and siltstones to medium sandstones of Upper Cretaceous age, northwest Vietnam) are used to evaluate the effects of varying contributions by pigment hematite to remanence, rock magnetic, and magnetic fabric properties. All rocks are well-characterized petrographically, so that the modal abundance of detrital oxides is known. The Chugwater siltstones are notable because of a relatively low Tlub spectra (below about 620o C), with no evidence of a low coercivity cubic phase. Rock magnetic and magnetic fabric properties are monitored as a function of progressive chemical demagnetization to further elucidate the role of hematite pigment in rocks that have contributed much to the paleomagnetic record of Earth.

SeaWiFS Technical Report Series. Volume 29; The SeaWiFS CZCS-Type Pigment Algorithm

NASA Technical Reports Server (NTRS)

Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Aiken, James; Moore, Gerald F.; Trees, Charles C.; Clark, Dennis K.

1995-01-01

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission will provide operational ocean color that will be superior to the previous Coastal Zone Color Sensor (CZCS) proof-of-concept mission. An algorithm is needed that exploits the full functionality of SeaWiFS whilst remaining compatible in concept with algorithms used for the CZCS. This document describes the theoretical rationale of radiance band-ratio methods for determining chlorophyll-a and other important biogeochemical parameters, and their implementation for the SeaWIFS mission. Pigment interrelationships are examined to explain the success of the CZCS algorithms. In the context where chlorophyll-a absorbs only weakly at 520 nm, the success of the 520 nm to 550 nm CZCS band ratio needs to be explained. This is explained by showing that in pigment data from a range of oceanic provinces chlorophyll-a (absorbing at less than 490 nm), carotenoids (absorbing at greater than 460 nm), and total pigment are highly correlated. Correlations within pigment groups particularly photoprotectant and photosynthetic carotenoids are less robust. The sources of variability in optical data are examined using the NIMBUS Experiment Team (NET) bio-optical data set and bio-optical model. In both the model and NET data, the majority of the variance in the optical data is attributed to variability in pigment (chlorophyll-a), and total particulates, with less than 5% of the variability resulting from pigment assemblage. The relationships between band ratios and chlorophyll is examined analytically, and a new formulation based on a dual hyperbolic model is suggested which gives a better calibration curve than the conventional log-log linear regression fit. The new calibration curve shows the 490:555 ratio is the best single-band ratio and is the recommended CZCS-type pigment algorithm. Using both the model and NET data, a number of multiband algorithms are developed; the best of which is an algorithm based on the 443:555 and 490:555 ratios. From model data, the form of potential algorithms for other products, such as total particulates and dissolved organic matter (DOM), are suggested.

SeaWiFS Technical Report Series. Volume 29: SeaWiFS CZCS-type pigment algorithm

NASA Technical Reports Server (NTRS)

Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Aiken, James; Moore, Gerald F.; Trees, Charles C.; Clark, Dennis K.

1995-01-01

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission will provide operational ocean color that will be superior to the previous Coastal Zone Color Sensor (CZCS) proof-of-concept mission. an algorithm is needed that exploits the full functionality of SeaWiFS whilst remaining compatible in concept with algorithms used for the CZCS. This document describes the theoretical rationale of radiance band-radio methods for determining chlorophyll alpha and other important biogeochemical parameters, and their implementation for the SeaWiFS mission. Pigment interrelationships are examined to explain the success of the CZCS algorithms. In the context where chlorophyll alpha absorbs only weakly at 520 nm, the success of the 520 nm to 550 nm CZCS band ratio needs to be explained. This is explained by showing that in pigment data from a range of oceanic provinces chlorophyll alpha (absorbing at less than 490 nm), carotenoids (absorbing at greater than 460 nm), and total pigment are highly correlated. Correlations within pigment groups particularly photoprotectant and photosynthetic carotenoids are less robust. The sources of variability in optical data re examined using the NIMBUS Experiment Team (NET) bio-optical data set and bio-optical model. In both the model and NET data, the majority of the variance in the optical data is attributed to variability in pigment (chlorophyll alpha, and total particulates, with less than 5% of the variability resulting from pigment assemblage. The relationships between band ratios and chlorophyll is examined analytically, and a new formulation based on a dual hyperbolic model is suggested which gives a better calibration curve than the conventional log-log linear regression fit. The new calibration curve shows that 490:555 ratio is the best single-band ratio and is the recommended CZCS-type pigment algorithm. Using both the model and NET data, a number of multiband algorithms are developed; the best of which is an algorithm based on the 443:555 and 490:555 ratios. From model data, the form of potential algorithms for other products, such as total particulates and dissolved organic matter (DOM), are suggested.

Formalin deposition as artifact in biopsies from patients affected by a new variant of endemic pemphigus foliaceus in El Bagre, Colombia, South America.

PubMed

Abreu Velez, Ana Maria; Howard, Michael S; Restrepo-Isaza, Marcos; Smoller, Bruce

2010-08-01

Most autoimmune diseases occur sporadically; however, endemic pemphigus foliaceus (EPF) is present in specific locales restricted to some geographic rural regions mostly in South America, Central America and in Tunisia (Africa). Its geographic restriction makes it an invaluable natural model for studying how the environment, genetic background and host response contribute to the development of autoimmunity. We described a new variant of EPF in El Bagre, Colombia, (El Bagre-EPF). When we examined the skin biopsies from 10 patients and controls from the endemic area, we detected in a systematic manner several types of pigmentation, sometimes intracellular, and sometimes in the extracellular matrix in most biopsies. We aim to determine the nature of this pigment in these skin biopsies. We studied 10 patients and 10 controls matched by sex, age and work activity living in the endemic area by routine hematoxylin and eosin (H&E). We were unable to find any bacteriological or parasitic organism. Specifically, we searched for several tropical disease agents as possible causative agents of this pigment. Iron stains and melanin pigment bleaching techniques failed to determine the etiology of this pigment. We then tried the removal of formalin pigment using picric acid. The pigment was removed after very strong treatment with different acids including picric acid. Formalin pigment shares many properties with hemozoin. In this case, the authors recommend the use of neutral buffered formalin to prevent the formation of formalin pigment especially after long periods of fixation when taking biopsies under extreme temperature and environmental humidity.

Identification of YfiH and the Catalase CatA As Polyphenol Oxidases of Aeromonas media and CatA as a Regulator of Pigmentation by Its Peroxyl Radical Scavenging Capacity

PubMed Central

Chai, Baozhong; Qiao, Yunqian; Wang, He; Zhang, Xiaoming; Wang, Jiao; Wang, Choushi; Zhou, Ping; Chen, Xiangdong

2017-01-01

Pyomelanin is the major constituent of pigment in melanogenic Aeromonas strains of bacteria. However, eumelanin, synthesized from tyrosine via L-DOPA and polyphenol oxidases (PPOs), may also be present in this genus since L-DOPA is frequently detected in culture fluids of several species. To address this question, we used a deletion mutant of Aeromonas media strain WS, in which pyomelanin synthesis is completely blocked under normal culture conditions. When tyrosine was supplied to the medium, we observed residual melanin accumulation, which we interpret as evidence for existence of the DOPA-melanin pathway. We traced enzymatic activity in this bacterium using native-polyacrylamide gel electrophoresis. Two PPOs: YfiH, a laccase-like protein, and CatA, a catalase, were identified. However, neither protein was critical for the residual pigmentation in pyomelanin-deficient mutant. We speculate that eumelanin synthesis may require other unknown enzymes. Deletion of yfiH did not affect pigmentation in A. media strain WS, while deletion of the CatA-encoding gene katE resulted in a reduction of melanin accumulation, but it started 9 h earlier than in the wild-type. Since catalases regulate reactive oxygen species levels during melanogenesis, we speculated that CatA affects pigmentation through its peroxyl radical scavenging capacity. Consistent with this, expression of the catalases Hpi or Hpii from Escherichia coli in the katE deletion strain of A. media strain WS restored pigmentation to the wild-type level. Hpi and Hpii also exhibited PPO activity, suggesting that catalase may represent a new class of PPOs. PMID:29051758

Pigment dispersion and Artisan phakic intraocular lenses: crystalline lens rise as a safety criterion.

PubMed

Baïkoff, Georges; Bourgeon, Grégoire; Jodai, Horacio Jitsuo; Fontaine, Aline; Lellis, Fernando Viera; Trinquet, Laure

2005-04-01

To validate the theory that crystalline lens rise can be used as a safety criterion to prevent pigment dispersion in eyes with an Artisan phakic intraocular lens (IOL) (Ophtec BV). Monticelli Clinic, Marseilles, France. A comparative analysis of crystalline lens rise in 9 eyes with pigment dispersion and 78 eyes without dispersion was performed. All eyes had previous implantation of an Artisan IOL. Anterior segment imaging was done using an anterior chamber optical coherence tomography (AC OCT) prototype. Crystalline lens rise was defined by the distance between the anterior pole of the crystalline lens and the horizontal plane joining the opposite iridocorneal recesses. The study confirmed that crystalline lens rise can be considered a safety criterion for implantation of Artisan-type phakic IOLs. The higher the crystalline lens rise, the greater the risk for developing pigment dispersion in the area of the pupil. This complication occurred more frequently in hyperopic eyes than in myopic eyes. Results indicate there is little or no risk for pigment dispersion if the rise is less than 600 microm; 67% of eyes with a rise of 600 microm or more developed pupillary pigment dispersion. In some cases in which the IOL was loosely fixated, there was no traction on the iris root and dispersion was prevented or delayed. Crystalline lens rise should be considered a new safety criterion for Artisan phakic IOL implantation and should also be applied to other types of phakic IOLs. The distance remaining between the crystalline lens rise and a 600 microm theoretical safety level allows one to calculate how long the IOL can safely remain in the eye.

Retinal vascular nonperfusion in siblings with Dandy-Walker variant.

PubMed

Rusu, Irene; Gupta, Mrinali Patel; Patel, Samir N; Oltra, Erica; Chan, R V Paul

2016-04-01

We report the case of a 2-month-old girl with Dandy-Walker variant who presented with strabismus, pathologic myopia measuring -16.00 D in each eye, diffuse chorioretinal atrophy and pigment mottling in the macula of both eyes, and areas of retinal capillary nonperfusion in both eyes. The patient's brother also has Dandy-Walker variant and was found to have bilateral severe myopia, myopic fundi, tilted optic disks with peripapillary atrophy, extensive areas of white without pressure, areas of lattice degeneration, and several chronic-appearing atrophic retinal holes surrounded by pigmentation. We hypothesize that children with Dandy-Walker variant may present with refractive errors such as pathologic myopia and with diverse retinal findings, including retinal ischemia. A lower threshold for ophthalmologic examination may be considered in this population. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Birthmarks

MedlinePlus

... Two types of vascular birthmarks are hemangiomas and port-wine stains. Pigmented birthmarks are made of a ... your appearance. But certain types can increase your risk of skin cancer. If your birthmark bleeds, hurts, ...

In vivo measurements of cutaneous melanin across spatial scales: using multiphoton microscopy and spatial frequency domain spectroscopy

PubMed Central

Saager, Rolf B.; Balu, Mihaela; Crosignani, Viera; Sharif, Ata; Durkin, Anthony J.; Kelly, Kristen M.; Tromberg, Bruce J.

2015-01-01

Abstract. The combined use of nonlinear optical microscopy and broadband reflectance techniques to assess melanin concentration and distribution thickness in vivo over the full range of Fitzpatrick skin types is presented. Twelve patients were measured using multiphoton microscopy (MPM) and spatial frequency domain spectroscopy (SFDS) on both dorsal forearm and volar arm, which are generally sun-exposed and non-sun-exposed areas, respectively. Both MPM and SFDS measured melanin volume fractions between ∼5% (skin type I non-sun-exposed) and 20% (skin type VI sun exposed). MPM measured epidermal (anatomical) thickness values ∼30–65  μm, while SFDS measured melanin distribution thickness based on diffuse optical path length. There was a strong correlation between melanin concentration and melanin distribution (epidermal) thickness measurements obtained using the two techniques. While SFDS does not have the ability to match the spatial resolution of MPM, this study demonstrates that melanin content as quantified using SFDS is linearly correlated with epidermal melanin as measured using MPM (R2=0.8895). SFDS melanin distribution thickness is correlated to MPM values (R2=0.8131). These techniques can be used individually and/or in combination to advance our understanding and guide therapies for pigmentation-related conditions as well as light-based treatments across a full range of skin types. PMID:26065839

DFT/TDDFT study on the photodissociation mechanism of the original monascus red and orange pigments

NASA Astrophysics Data System (ADS)

Liu, Yi; Wu, Li; Lv, Qingzhang

2015-06-01

The weak photostability has to some extent restricted the wide utilization of monascus pigments in food industries, and their photobleaching mechanism is unclear yet. Density functional theory and time-dependent density functional theory at B3LYP/6-311+G(d,p) level have been performed to optimize the geometries of ground states, single and triplet excited-states of the original monascus red and orange pigments, the possible photodissociation mechanism of which is analyzed according to the calculated data. It is the break of the chromophores, conjugated π bonds which has induced their decoloration. The photodissociation of these pigments involves three steps, excitation of the large conjugated π system, water addition to the singlet or triplet excited-state, and Norrish type I photochemical cleavage reactions of the side chains. The former two steps are much more important steps which have led to the destruction of the chromophores and the fading of the four original monascus red and orange pigments. According to the photobleaching mechanism obtained, one could find some solutions to enhance the photostability of these monascus colorants during the food processing process and extend the shelf life of the foods added with monascus pigments.

An orthologue of the kit-related gene fms is required for development of neural crest-derived xanthophores and a subpopulation of adult melanocytes in the zebrafish, Danio rerio.

PubMed

Parichy, D M; Ransom, D G; Paw, B; Zon, L I; Johnson, S L

2000-07-01

Developmental mechanisms underlying traits expressed in larval and adult vertebrates remain largely unknown. Pigment patterns of fishes provide an opportunity to identify genes and cell behaviors required for postembryonic morphogenesis and differentiation. In the zebrafish, Danio rerio, pigment patterns reflect the spatial arrangements of three classes of neural crest-derived pigment cells: black melanocytes, yellow xanthophores and silver iridophores. We show that the D. rerio pigment pattern mutant panther ablates xanthophores in embryos and adults and has defects in the development of the adult pattern of melanocyte stripes. We find that panther corresponds to an orthologue of the c-fms gene, which encodes a type III receptor tyrosine kinase and is the closest known homologue of the previously identified pigment pattern gene, kit. In mouse, fms is essential for the development of macrophage and osteoclast lineages and has not been implicated in neural crest or pigment cell development. In contrast, our analyses demonstrate that fms is expressed and required by D. rerio xanthophore precursors and that fms promotes the normal patterning of melanocyte death and migration during adult stripe formation. Finally, we show that fms is required for the appearance of a late developing, kit-independent subpopulation of adult melanocytes. These findings reveal an unexpected role for fms in pigment pattern development and demonstrate that parallel neural crest-derived pigment cell populations depend on the activities of two essentially paralogous genes, kit and fms.

"Occult cutaneous lymphangiectasis": an unusual case of cutaneous lymphangioma.

PubMed

Kakinuma, Hiroshi

2002-01-01

An unusual case of cutaneous lymphatic abnormality is described and named as "occult cutaneous lymphangietasis". A 26-year-old man had noticed pigmented maculae in the left inguinofemoral region and waist, which had gradually increased in number for as long as he could remember. The peculiar distribution of the eruptions and their transient saccular dilatation due to infection suggested that they were of lymphatic origin. Lymphangiography showed the presence of dilated lymphatics in the left inguinofemoral area and correspondence of the distribution of dermal backflow with the locations of the pigmented maculae. The histology is consistent with a diagnosis of lymphangioma. We could find no other reports of cases of cutaneous lymphangioma featuring pigmented maculae as the sole manifestation, although whether the pigmentation is an original clinical feature of this type of lymphatic abnormality is still an open question.

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 associated with photo-aging. PMID:25490395

A global seasonal surface ocean climatology of phytoplankton types based on CHEMTAX analysis of HPLC pigments

NASA Astrophysics Data System (ADS)

Swan, Chantal M.; Vogt, Meike; Gruber, Nicolas; Laufkoetter, Charlotte

2016-03-01

Much advancement has been made in recent years in field data assimilation, remote sensing and ecosystem modeling, yet our global view of phytoplankton biogeography beyond chlorophyll biomass is still a cursory taxonomic picture with vast areas of the open ocean requiring field validations. High performance liquid chromatography (HPLC) pigment data combined with inverse methods offer an advantage over many other phytoplankton quantification measures by way of providing an immediate perspective of the whole phytoplankton community in a sample as a function of chlorophyll biomass. Historically, such chemotaxonomic analysis has been conducted mainly at local spatial and temporal scales in the ocean. Here, we apply a widely tested inverse approach, CHEMTAX, to a global climatology of pigment observations from HPLC. This study marks the first systematic and objective global application of CHEMTAX, yielding a seasonal climatology comprised of ~1500 1°×1° global grid points of the major phytoplankton pigment types in the ocean characterizing cyanobacteria, haptophytes, chlorophytes, cryptophytes, dinoflagellates, and diatoms, with results validated against prior regional studies where possible. Key findings from this new global view of specific phytoplankton abundances from pigments are a) the large global proportion of marine haptophytes (comprising 32±5% of total chlorophyll), whose biogeochemical functional roles are relatively unknown, and b) the contrasting spatial scales of complexity in global community structure that can be explained in part by regional oceanographic conditions. The results are publically accessible via

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

PubMed

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.

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.

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.

Incorporation of Chemochromic Pigment into a Variety of Articles as an Indicator for the Presence of Hypergolic Fuels

NASA Technical Reports Server (NTRS)

Captain, Janine E. (Inventor); Santiago-Maldonado, Edgardo (Inventor); Roberson, Luke B. (Inventor); DeVor, Robert W. (Inventor)

2014-01-01

A chemochromic indicator is provided that includes a hypergolic fuel sensing chemochromic pigment that change from a first color to a second color in the presence of a hypergolic fuel. In a first embodiment, a chemochromic indicator is provided for detecting the presence of a hypergolic fuel such that the irreversible hypergolic fuel sensing chemochromic pigment includes potassium tetrachloroaurate (KAuCl.sub.4). There are several types of chemochromic indicators, for example, the article used to form the chemochromic indicators include, but are not limited to, wipe materials, silicone/TEFLON tape, manufactured parts, fabrics, extruded parts, and paints.

Exclusion of chromosome 1q21-q31 from linkage to three pedigrees affected by the pigment-dispersion syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paglinauan, C.; Haines, J.L.; Del Bono, E.A.

1995-05-01

The pigment-dispersion syndrome is a form of open-angle glaucoma that usually affects individuals in the first 3 decades of life. In addition to the typical optic-nerve degeneration seen in all types of glaucoma, the pigment-dispersion syndrome is characterized by distinctive clinical features including the deposition of pigment granules from the iris epithelium on a variety of ocular structures including the trabecular meshwork. Frequently this disorder affects young myopic individuals. In the early stages of the disease, affected individuals may have clinical evidence of dispersed pigment without an associated elevation of intraocular pressure and optic-nerve degeneration. However, as the disease processmore » progresses, many affected individuals ({approximately}50%) will develop elevated intraocular pressure and degeneration of the optic nerve, causing a permanent loss of sight. The pigment-dispersion syndrome shares several clinical features with the form of autosomal dominant juvenile open-angle glaucoma that recently has been mapped to the 1q21-q31 region of chromosome 1. Our results indicate that the pigment-dispersion syndrome, a form of glaucoma that may also affect the juvenile population, is genetically unrelated to the autosomal dominant form of juvenile glaucoma caused by a defect in a gene located in the 1q21-q31 region of chromosome 1. 15 refs., 2 figs., 1 tab.« less

Interaction between G Protein-Coupled Receptor 143 and Tyrosinase: Implications for Understanding Ocular Albinism Type 1.

PubMed

De Filippo, Elisabetta; Schiedel, Anke C; Manga, Prashiela

2017-02-01

Developmental eye defects in X-linked ocular albinism type 1 are caused by G-protein coupled receptor 143 (GPR143) mutations. Mutations result in dysfunctional melanosome biogenesis and macromelanosome formation in pigment cells, including melanocytes and retinal pigment epithelium. GPR143, primarily expressed in pigment cells, localizes exclusively to endolysosomal and melanosomal membranes unlike most G protein-coupled receptors, which localize to the plasma membrane. There is some debate regarding GPR143 function and elucidating the role of this receptor may be instrumental for understanding neurogenesis during eye development and for devising therapies for ocular albinism type I. Many G protein-coupled receptors require association with other proteins to function. These G protein-coupled receptor-interacting proteins also facilitate fine-tuning of receptor activity and tissue specificity. We therefore investigated potential GPR143 interaction partners, with a focus on the melanogenic enzyme tyrosinase. GPR143 coimmunoprecipitated with tyrosinase, while confocal microscopy demonstrated colocalization of the proteins. Furthermore, tyrosinase localized to the plasma membrane when coexpressed with a GPR143 trafficking mutant. The physical interaction between the proteins was confirmed using fluorescence resonance energy transfer. This interaction may be required in order for GPR143 to function as a monitor of melanosome maturation. Identifying tyrosinase as a potential GPR143 binding protein opens new avenues for investigating the mechanisms that regulate pigmentation and neurogenesis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Importance of the green color, absorption gradient, and spectral absorption of chloroplasts for the radiative energy balance of leaves.

PubMed

Kume, Atsushi

2017-05-01

Terrestrial green plants absorb photosynthetically active radiation (PAR; 400-700 nm) but do not absorb photons evenly across the PAR waveband. The spectral absorbance of photosystems and chloroplasts is lowest for green light, which occurs within the highest irradiance waveband of direct solar radiation. We demonstrate a close relationship between this phenomenon and the safe and efficient utilization of direct solar radiation in simple biophysiological models. The effects of spectral absorptance on the photon and irradiance absorption processes are evaluated using the spectra of direct and diffuse solar radiation. The radiation absorption of a leaf arises as a consequence of the absorption of chloroplasts. The photon absorption of chloroplasts is strongly dependent on the distribution of pigment concentrations and their absorbance spectra. While chloroplast movements in response to light are important mechanisms controlling PAR absorption, they are not effective for green light because chloroplasts have the lowest spectral absorptance in the waveband. With the development of palisade tissue, the incident photons per total palisade cell surface area and the absorbed photons per chloroplast decrease. The spectral absorbance of carotenoids is effective in eliminating shortwave PAR (<520 nm), which contains much of the surplus energy that is not used for photosynthesis and is dissipated as heat. The PAR absorptance of a whole leaf shows no substantial difference based on the spectra of direct or diffuse solar radiation. However, most of the near infrared radiation is unabsorbed and heat stress is greatly reduced. The incident solar radiation is too strong to be utilized for photosynthesis under the current CO 2 concentration in the terrestrial environment. Therefore, the photon absorption of a whole leaf is efficiently regulated by photosynthetic pigments with low spectral absorptance in the highest irradiance waveband and through a combination of pigment density distribution and leaf anatomical structures.

Mechanical properties of elytra from Tribolium castaneum wild-type and body color mutant strains.

PubMed

Lomakin, Joseph; Arakane, Yasuyuki; Kramer, Karl J; Beeman, Richard W; Kanost, Michael R; Gehrke, Stevin H

2010-12-01

Cuticle tanning in insects involves simultaneous cuticular pigmentation and hardening or sclerotization. The dynamic mechanical properties of the highly modified and cuticle-rich forewings (elytra) from Tribolium castaneum (red flour beetle) wild-type and body color mutant strains were investigated to relate body coloration and elytral mechanical properties. There was no statistically significant variation in the storage modulus E' among the elytra from jet, cola, sooty and black mutants or between the mutants and the wild-type GA-1 strain: E' averaged 5.1 ± 0.6 GPa regardless of body color. E' is a power law function of oscillation frequency for all types. The power law exponent, n, averaged 0.032 ± 0.001 for elytra from all genotypes except black; this small value indicated that the elytra are cross-linked. Black elytra, however, displayed a significantly larger n of 0.047 ± 0.004 and an increased loss tangent (tan δ), suggesting that metabolic differences in the black mutant strain result in elytra that are less cross-linked and more pigmented than the other types. These results are consistent with the hypothesis that black elytra have a β-alanine-deficient and dopamine-abundant metabolism, leading to greater melanin (black pigment) production, probably at the expense of cross-linking of cuticular proteins mediated by N-β-alanyldopamine quinone. Copyright © 2010 Elsevier Ltd. All rights reserved.

Analysis of lipophilic pigments from a phototrophic microbial mat community by high performance liquid chromatography

NASA Technical Reports Server (NTRS)

Palmisano, A. C.; Cronin, S. E.; Des Marais, D. J.

1988-01-01

As assay for lipophilic pigments in phototrophic microbial mat communities using reverse phase-high performance liquid chromatography was developed which allows the separation of 15 carotenoids and chloropigments in a single 30 min program. Lipophilic pigments in a laminated mat from a commercial salina near Laguna Guerrero Negro, Baja California Sur, Mexico reflected their source organisms. Myxoxanthophyll, echinenone, canthaxanthin, and zeaxanthin were derived from cyanobacteria; chlorophyll c, and fucoxanthin from diatoms; chlorophyll a from cyanobacteria and diatoms; bacteriochlorophylls a and c, bacteriophaeophytin a, and gamma-carotene from Chloroflexus spp.; and beta-carotene from a variety of phototrophs. Sensitivity of detection was 0.6-6.1 ng for carotenoids and 1.7-12 ng for most chloropigments. This assay represents a significant improvement over previous analyses of lipophilic pigments in microbial mats and promises to have a wider application to other types of phototrophic communities.

Pigment identification on medieval manuscripts, paintings and other artefacts by Raman microscopy: applications to the study of three German manuscripts

NASA Astrophysics Data System (ADS)

Burgio, Lucia; Ciomartan, Dan A.; Clark, Robin J. H.

1997-03-01

The identification of the pigments used to illuminate medieval manuscripts, paintings and other artefacts has received a major boost recently through perceptive studies carried out by Raman microscopy. A brief summary of the background of the technique is given. The results of studies on three illuminated German manuscripts are presented. The pigments vermilion HgS, iron oxide Fe 2O 3, azurite 2CuCO 3.Cu(OH) 2, malachite CuCo 3.Cu(OH) 2, lampblack (essentially carbon), white lead 2PbCO 3.Pb(OH) 2, lead tin yellow type I Pb 2SnO 4, and lazurite Na 8[Al 6Si 6O 24]S n (but only in admixture with Pb 2SnO 4, whereby it forms a green pigment), have been identified on these manuscripts on the basis of Raman microscopy and the results discussed.

Identification and quantification of anthocyanin pigments in colored rice.

PubMed

Kim, Min-Kyoung; Kim, Han-Ah; Koh, Kwangoh; Kim, Hee-Seon; Lee, Young Sang; Kim, Yong Ho

2008-01-01

Anthocyanin pigments from varieties of black, red and wild rice were identified and quantified to evaluate their potential as nutritional function, natural colorants or functional food ingredients. Anthocyanin extraction was conducted with acidified methanol with 0.1M HCl (85:15, v/v) and identification of anthocyanin, aglycone and sugar moieties was conducted by comparison with purified standards by HPLC, Ultraviolet-Visible absorption spectrophotometer and paper chromatography. Black and wild rice showed three different types of pigments by HPLC whereas red rice variety did not show any anthocyanins. Out of three pigments detected, one (peak 2) was characterized as cyanidin-3-glucoside (C3G) by comparison of spectroscopic and chromatographic properties with an authentic standard, and another (peak 3) was tentatively identified as cyanidin-fructoside on the basis of spectroscopic properties with lambda(max) of aglycone in 1% HCl methanol at 537 nm, electrospray ionization mass spectra with major ions at 449 and 287 m/z and chromatographic properties. But another pigment (peak 1) has not been characterized. The most abundant anthocyanin in black and wild rice was C3G.

Retinal pigment epithelium culture;a potential source of retinal stem cells.

PubMed

Akrami, Hassan; Soheili, Zahra-Soheila; Khalooghi, Keynoush; Ahmadieh, Hamid; Rezaie-Kanavi, Mojgan; Samiei, Shahram; Davari, Malihe; Ghaderi, Shima; Sanie-Jahromi, Fatemeh

2009-07-01

To establish human retinal pigment epithelial (RPE) cell culture as a source for cell replacement therapy in ocular diseases. Human cadaver globes were used to isolate RPE cells. Each globe was cut into several pieces of a few millimeters in size. After removing the sclera and choroid, remaining tissues were washed in phosphate buffer saline and RPE cells were isolated using dispase enzyme solution and cultured in Dulbecco's Modified Eagle's Medium: Nutrient Mixture F-12 supplemented with 10% fetal calf serum. Primary cultures of RPE cells were established and spheroid colonies related to progenitor/stem cells developed in a number of cultures. The colonies included purely pigmented or mixed pigmented and non-pigmented cells. After multiple cellular passages, several types of photoreceptors and neural-like cells were detected morphologically. Cellular plasticity in RPE cell cultures revealed promising results in terms of generation of stem/progenitor cells from human RPE cells. Whether the spheroids and neural-like retinal cells were directly derived from retinal stem cells or offspring of trans-differentiating or de-differentiating RPE cells remains to be answered.

Retinal Pigment Epithelium Culture;a Potential Source of Retinal Stem Cells

PubMed Central

Akrami, Hassan; Soheili, Zahra-Soheila; Khalooghi, Keynoush; Ahmadieh, Hamid; Rezaie-Kanavi, Mojgan; Samiei, Shahram; Davari, Malihe; Ghaderi, Shima; Sanie-Jahromi, Fatemeh

2009-01-01

Purpose To establish human retinal pigment epithelial (RPE) cell culture as a source for cell replacement therapy in ocular diseases. Methods Human cadaver globes were used to isolate RPE cells. Each globe was cut into several pieces of a few millimeters in size. After removing the sclera and choroid, remaining tissues were washed in phosphate buffer saline and RPE cells were isolated using dispase enzyme solution and cultured in Dulbecco’s Modified Eagle’s Medium: Nutrient Mixture F-12 supplemented with 10% fetal calf serum. Results Primary cultures of RPE cells were established and spheroid colonies related to progenitor/stem cells developed in a number of cultures. The colonies included purely pigmented or mixed pigmented and non-pigmented cells. After multiple cellular passages, several types of photoreceptors and neural-like cells were detected morphologically. Conclusion Cellular plasticity in RPE cell cultures revealed promising results in terms of generation of stem/progenitor cells from human RPE cells. Whether the spheroids and neural-like retinal cells were directly derived from retinal stem cells or offspring of trans-differentiating or de-differentiating RPE cells remains to be answered. PMID:23198062

Adsorption and desorption properties of macroporous resins for anthocyanins from the calyx extract of roselle (Hibiscus sabdariffa L.).

PubMed

Chang, Xiu-Lian; Wang, Dong; Chen, Bi-Yun; Feng, Yong-Mei; Wen, Shao-Hong; Zhan, Peng-Yuan

2012-03-07

Adsorption of roselle anthocynins, a natural pigment, onto various macroporous resins was optimized to develop a simple and efficient process for industrial separation and purification of roselle anthocyanins. Nine different macroporous resins (AB-8, X-5, HPD-100, SP-207, XAD-4, LS-305A, DM-21, LS-610B, and LS-305) were evaluated for the adsorption properties of the anthocyanins extracted from the calyx extract of Hibiscus sabdariffa L. The influences of phase contact time, solution pH, initial anthocyanin concentration, and ethanol concentration with different citric acid amounts were studied by the static adsorption/desorption method. The adsorption isotherm data were fitted well to the Langmuir isotherm, and according to this model, LS-610B and LS-305 exhibited the highest monolayer sorption capacities of 31.95 and 38.16 mg/g, respectively. The kinetic data were modeled using pseudo-first-order, pseudo-second-order, and intraparticle diffusion equations. The experimental data were well described by the pseudo-second-order kinetic model. Continuous column adsorption-regeneration cycles indicated negligible capacity loss of LS-305 during operation. The overall yield of pigment product was 49.6 mg/g dried calyces. The content of roselle anthocynins in the pigment product was 4.85%.

Sylvatiins, acetylglucosylated hydrolysable tannins from the petals of Geranium sylvaticum show co-pigment effect.

PubMed

Tuominen, Anu; Sinkkonen, Jari; Karonen, Maarit; Salminen, Juha-Pekka

2015-07-01

Four hydrolysable tannins, named as sylvatiins A (1), B (2), C (3) and D (4), were isolated from the petals of Geranium sylvaticum. On the basis of spectrometric evidence of NMR analysis ((1)H NMR, (13)C NMR, DQF-COSY, TOCSY, NOESY, HSQC and HMBC), circular dichroism (CD) and ESI-MS/MS, sylvatiins A, B and C were characterized as galloyl glucoses containing one or two acetylglucoses attached to the 3-OH of the galloyl group, whereas sylvatiin D was found to have a chebulinic acid core containing acetylglucose attached in a similar way. The potential of these compounds to act as defensive compounds against herbivores was evaluated using the radial diffusion assay that measures the protein precipitation capacity. In addition, the capacity of sylvatiins to act as co-pigments with anthocyanins of G. sylvaticum petals was measured in vitro at different pH values. Sylvatiins A and D maintained efficiently the purple flower color near the natural pH of petal cells. The amount of sylvatiins was changed according to the flower color; deep purple petals with higher amount of anthocyanin contained more sylvatiins A and C than whiter petals. It was concluded that G. sylvaticum petal cells may accumulate sylvatiins for intermolecular co-pigmentation purposes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification of pigmented Serratia marcescens symbiotically associated with Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae).

PubMed

Scrascia, Maria; Pazzani, Carlo; Valentini, Franco; Oliva, Marta; Russo, Valentina; D'Addabbo, Pietro; Porcelli, Francesco

2016-10-01

To characterize red pigment-producing bacteria (RPPB) regularly released during oviposition by red palm weevil (RPW), RPPB were recovered from eggs deposited in apples supplied as substrate for oviposition. The presence of RPPB was also detected from gut, the reproductive apparatus of dissected adult and virgin insects and from pupal cases collected within infested palms. RPPB were also identified all along the tissue of these palms. Analysis of the 16S rDNA, gyrB, rpoB, recA, and groEL sequences assigned RPPB to the species Serratia marcescens. RPPB exhibited an antimicrobial activity assessed by the agar well diffusion method against a number of gram-positive and gram-negative bacteria. In this study, we first report the identification of a red pigment-producing S. marcescens as extracellular symbiont of RPW. Route of transmission, detection within different organs, and a wide spread along the infested palm tissue, suggested S. marcescens is present as extracellular symbiont in different developmental stages of the RPW. Additionally, the antimicrobial activity exhibited versus Bacillus spp., Paenibacillus spp., and Lysinibacillus spp., reported as insect pathogens and potential candidates for biocontrol agents, could ascribe for S. marcescens a potential protective role. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Differentiation of pigmented Spitz nevi and Reed nevi by integration of dermatopathologic and dermatoscopic findings

PubMed Central

Bär, Michael; Tschandl, Philipp; Kittler, Harald

2012-01-01

Background: It is unclear whether pigmented Spitz and Reed nevi are distinct morphologic entities or part of the spectrum of Spitz nevi. Methods: In a retrospective observational study we analyzed dermatopathologic slides of 22 cases with clinical and dermatoscopic features indicative of pigmented Spitz or Reed nevus in a blinded fashion according to predefined criteria and subsequently correlated dermatopathologic with clinical and dermatoscopic findings. Results: We differentiated pigmented Spitz and Reed nevus dermatopathologically by their capacity of melanin production and a vertical versus horizontal growth pattern. Based on histopathology 20 nevi (91%) could be reliably diagnosed as Reed nevus (68%, n=15) or as pigmented Spitz nevus (23%, n=5). In two cases (9%, n=2) it was not possible to make a clear distinction from a dermatopathologic point of view. Dermatopathologic-dermatoscopic correlation showed that Reed nevi were characterized by a dermatoscopic pattern of peripheral radial lines or pseudopods (fascicular growth pattern), whereas pigmented Spitz nevi were typified by a pattern consisting of clods (nested growth pattern). “Spitz cells” (large epithelioid melanocytes) were more commonly found in Spitz nevi (100%, n = 5) but were also present in Reed nevi (n=6, 40%). Spindle cells were found in both types of nevi. Conclusions: Pigmented Spitz and Reed nevi can be reliably distinguished based on their dermatopathologic and dermatoscopic patterns. The specific dermatopathologic patterns of pigmented Spitz and Reed nevi correspond well to their dermatoscopic patterns. The presence of “Spitz cells” or spindle cells should not be regarded as the decisive criterion to differentiate between these two entities. PMID:24765545

Pigmented Epithelioid Melanocytoma (PEM)/Animal Type Melanoma (ATM): Quest for an Origin. Report of One Unusual Case Indicating Follicular Origin and Another Arising in an Intradermal Nevus.

PubMed

Tarasen, Ashley; Carlson, J Andrew; Leonard, M Kathryn; Merlino, Glenn; Kaetzel, David; Slominski, Andrzej T

2017-08-15

Pigmented epithelioid melanocytoma (PEM) is a tumor encompassing epithelioid blue nevus of Carney complex (EBN of CNC) and was previously termed animal-type melanoma. Histologically PEMs are heavily pigmented spindled and epithelioid dermal melanocytic tumors with infiltrative borders, however, their origin remains unclear. Stem cells for the epidermis and hair follicle are located in the bulge area of the hair follicle with the potential to differentiate into multiple lineages. Multiple cutaneous carcinomas, including follicular cutaneous squamous cell carcinoma (FSCC), are thought to arise from stem cells in the follicular bulge. We present two cases of PEM/ATM in a 63 year-old male on the scalp with follicular origin and a 72 year-old female on the upper back arising in an intradermal nevus. Biopsy of both cases revealed a proliferation of heavily pigmented dermal nests of melanocytes with atypia. The Case 1 tumor was in continuation with the outer root sheath of the hair follicle in the bulge region. Case 2 arose in an intradermal melanocytic nevus. Rare mitotic figures, including atypical mitotic figures, were identified in both cases. We present two cases of PEM, with histologic evidence suggesting two origins: one from the follicular bulb and one from an intradermal nevus.

An endolithic microbial community in dolomite rock in central Switzerland: characterization by reflection spectroscopy, pigment analyses, scanning electron microscopy, and laser scanning microscopy.

PubMed

Horath, T; Neu, T R; Bachofen, R

2006-04-01

A community of endolithic microorganisms dominated by phototrophs was found as a distinct band a few millimeters below the surface of bare exposed dolomite rocks in the Piora Valley in the Alps. Using in situ reflectance spectroscopy, we detected chlorophyll a (Chl a), phycobilins, carotenoids, and an unknown type of bacteriochlorophyll-like pigment absorbing in vivo at about 720 nm. In cross sections, the data indicated a defined distribution of different groups of organisms perpendicular to the rock surface. High-performance liquid chromatography analyses of pigments extracted with organic solvents confirmed the presence of two types of bacteriochlorophylls besides chlorophylls and various carotenoids. Spherical organisms of varying sizes and small filaments were observed in situ with scanning electron microscopy and confocal laser scanning microscopy (one- and two-photon technique). The latter allowed visualization of the distribution of phototrophic microorganisms by the autofluorescence of their pigments within the rock. Coccoid cyanobacteria of various sizes predominated over filamentous ones. Application of fluorescence-labeled lectins demonstrated that most cyanobacteria were embedded in an exopolymeric matrix. Nucleic acid stains revealed a wide distribution of small heterotrophs. Some biological structures emitting a green autofluorescence remain to be identified.

Lack of tumour pigmentation in conjunctival melanoma is associated with light iris colour and worse prognosis.

PubMed

Brouwer, Niels J; Marinkovic, Marina; Luyten, Gregorius P M; Shields, Carol L; Jager, Martine J

2018-05-18

To investigate whether differences in iris colour, skin colour and tumour pigmentation are related to clinical outcome in conjunctival melanoma. Data of 70 patients with conjunctival melanoma from the Leiden University Medical Center (Leiden, The Netherlands) and 374 patients from the Wills Eye Hospital (Philadephia, USA) were reviewed. The relation between iris colour, skin colour and tumour pigmentation versus clinical parameters and outcome was investigated using univariate and multivariate regression analyses. A light iris colour (blue, grey, green) was present in 261 (59%) patients and a dark colour (hazel, brown) in 183 (41%). A low tumour pigmentation was detected in 130 (40%) and a high pigmentation in 197 (60%) patients. Low tumour pigmentation was associated with light iris colour (p=0.021) but not related to skin colour (p=0.92). In univariate analysis, neither iris nor skin colour was related to clinical outcome, while a low tumour pigmentation was related to metastasis formation (HR 2.37, p=0.004) and death (HR 2.42, p=0.020). In multivariate analysis, low tumour pigmentation was related to the development of recurrences (HR 1.63, p=0.043), metastasis formation (HR 2.48, p=0.004) and death (HR 2.60, p=0.014). Lightly pigmented tumours occurred especially in individuals with lightly coloured irises. While iris colour or skin colour was not significantly related to clinical outcome, a low tumour pigmentation was related to a worse outcome in patients with conjunctival melanoma. The amount and type of melanin in conjunctival melanocytes may be involved in the pathogenesis and behaviour of selected conjunctival melanoma. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A molecular systems approach to modelling human skin pigmentation: identifying underlying pathways and critical components.

PubMed

Raghunath, Arathi; Sambarey, Awanti; Sharma, Neha; Mahadevan, Usha; Chandra, Nagasuma

2015-04-29

Ultraviolet radiations (UV) serve as an environmental stress for human skin, and result in melanogenesis, with the pigment melanin having protective effects against UV induced damage. This involves a dynamic and complex regulation of various biological processes that results in the expression of melanin in the outer most layers of the epidermis, where it can exert its protective effect. A comprehensive understanding of the underlying cross talk among different signalling molecules and cell types is only possible through a systems perspective. Increasing incidences of both melanoma and non-melanoma skin cancers necessitate the need to better comprehend UV mediated effects on skin pigmentation at a systems level, so as to ultimately evolve knowledge-based strategies for efficient protection and prevention of skin diseases. A network model for UV-mediated skin pigmentation in the epidermis was constructed and subjected to shortest path analysis. Virtual knock-outs were carried out to identify essential signalling components. We describe a network model for UV-mediated skin pigmentation in the epidermis. The model consists of 265 components (nodes) and 429 directed interactions among them, capturing the manner in which one component influences the other and channels information. Through shortest path analysis, we identify novel signalling pathways relevant to pigmentation. Virtual knock-outs or perturbations of specific nodes in the network have led to the identification of alternate modes of signalling as well as enabled determining essential nodes in the process. The model presented provides a comprehensive picture of UV mediated signalling manifesting in human skin pigmentation. A systems perspective helps provide a holistic purview of interconnections and complexity in the processes leading to pigmentation. The model described here is extensive yet amenable to expansion as new data is gathered. Through this study, we provide a list of important proteins essential for pigmentation which can be further explored to better understand normal pigmentation as well as its pathologies including vitiligo and melanoma, and enable therapeutic intervention.

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

PubMed Central

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

2009-01-01

Pigment patterns in the integument have long-attracted attention from both scientists and non-scientists alike since their natural attractiveness combines with their excellence as models for the general problem of pattern formation. Pigment cells are formed from the neural crest and must migrate to reach their final locations. In this review, we focus on our current understanding of mechanisms underlying the control of pigment cell migration and patterning in diverse vertebrates. The model systems discussed here –chick, mouse, and zebrafish – each provide unique insights into the major morphogenetic events driving pigment pattern formation. In birds and mammals, melanoblasts must be specified before they can migrate on the dorsolateral pathway. Transmembrane receptors involved in guiding them onto this route include EphB2 and Ednrb2 in chick, and Kit in mouse. Terminal migration depends, in part, upon extracellular matrix reorganization by ADAMTS20. Invasion of the ectoderm, especially into the feather germ and hair follicles, requires specific signals that are beginning to be characterized. We summarize our current understanding of the mechanisms regulating melanoblast number and organization in the epidermis. We note the apparent differences in pigment pattern formation in poikilothermic vertebrates when compared with birds and mammals. With more pigment cell types, migration pathways are more complex and largely unexplored; nevertheless, a role for Kit signaling in melanophore migration is clear and indicates that at least some patterning mechanisms may be highly conserved. We summarize the multiple factors thought to contribute to zebrafish embryonic pigment pattern formation, highlighting a recent study identifying Sdf1a as one factor crucial for regulation of melanophore positioning. Finally, we discuss the mechanisms generating a second, metamorphic pigment pattern in adult fish, emphasizing recent studies strengthening the evidence that undifferentiated progenitor cells play a major role in generating adult pigment cells. PMID:18977309

Teleost Fish-Specific Preferential Retention of Pigmentation Gene-Containing Families After Whole Genome Duplications in Vertebrates

PubMed Central

Lorin, Thibault; Brunet, Frédéric G.; Laudet, Vincent; Volff, Jean-Nicolas

2018-01-01

Vertebrate pigmentation is a highly diverse trait mainly determined by neural crest cell derivatives. It has been suggested that two rounds (1R/2R) of whole-genome duplications (WGDs) at the basis of vertebrates allowed changes in gene regulation associated with neural crest evolution. Subsequently, the teleost fish lineage experienced other WGDs, including the teleost-specific Ts3R before teleost radiation and the more recent Ss4R at the basis of salmonids. As the teleost lineage harbors the highest number of pigment cell types and pigmentation diversity in vertebrates, WGDs might have contributed to the evolution and diversification of the pigmentation gene repertoire in teleosts. We have compared the impact of the basal vertebrate 1R/2R duplications with that of the teleost-specific Ts3R and salmonid-specific Ss4R WGDs on 181 gene families containing genes involved in pigmentation. We show that pigmentation genes (PGs) have been globally more frequently retained as duplicates than other genes after Ts3R and Ss4R but not after the early 1R/2R. This is also true for non-pigmentary paralogs of PGs, suggesting that the function in pigmentation is not the sole key driver of gene retention after WGDs. On the long-term, specific categories of PGs have been repeatedly preferentially retained after ancient 1R/2R and Ts3R WGDs, possibly linked to the molecular nature of their proteins (e.g., DNA binding transcriptional regulators) and their central position in protein-protein interaction networks. Taken together, our results support a major role of WGDs in the diversification of the pigmentation gene repertoire in the teleost lineage, with a possible link with the diversity of pigment cell lineages observed in these animals compared to other vertebrates. PMID:29599177

Influence of the Testa on Seed Dormancy, Germination, and Longevity in Arabidopsis1

PubMed Central

Debeaujon, Isabelle; Léon-Kloosterziel, Karen M.; Koornneef, Maarten

2000-01-01

The testa of higher plant seeds protects the embryo against adverse environmental conditions. Its role is assumed mainly by controlling germination through dormancy imposition and by limiting the detrimental activity of physical and biological agents during seed storage. To analyze the function of the testa in the model plant Arabidopsis, we compared mutants affected in testa pigmentation and/or structure for dormancy, germination, and storability. The seeds of most mutants exhibited reduced dormancy. Moreover, unlike wild-type testas, mutant testas were permeable to tetrazolium salts. These altered dormancy and tetrazolium uptake properties were related to defects in the pigmentation of the endothelium and its neighboring crushed parenchymatic layers, as determined by vanillin staining and microscopic observations. Structural aberrations such as missing layers or a modified epidermal layer in specific mutants also affected dormancy levels and permeability to tetrazolium. Both structural and pigmentation mutants deteriorated faster than the wild types during natural aging at room temperature, with structural mutants being the most strongly affected. PMID:10677433

Novel quantitative pigmentation phenotyping enhances genetic association, epistasis, and prediction of human eye colour.

PubMed

Wollstein, Andreas; Walsh, Susan; Liu, Fan; Chakravarthy, Usha; Rahu, Mati; Seland, Johan H; Soubrane, Gisèle; Tomazzoli, Laura; Topouzis, Fotis; Vingerling, Johannes R; Vioque, Jesus; Böhringer, Stefan; Fletcher, Astrid E; Kayser, Manfred

2017-02-27

Success of genetic association and the prediction of phenotypic traits from DNA are known to depend on the accuracy of phenotype characterization, amongst other parameters. To overcome limitations in the characterization of human iris pigmentation, we introduce a fully automated approach that specifies the areal proportions proposed to represent differing pigmentation types, such as pheomelanin, eumelanin, and non-pigmented areas within the iris. We demonstrate the utility of this approach using high-resolution digital eye imagery and genotype data from 12 selected SNPs from over 3000 European samples of seven populations that are part of the EUREYE study. In comparison to previous quantification approaches, (1) we achieved an overall improvement in eye colour phenotyping, which provides a better separation of manually defined eye colour categories. (2) Single nucleotide polymorphisms (SNPs) known to be involved in human eye colour variation showed stronger associations with our approach. (3) We found new and confirmed previously noted SNP-SNP interactions. (4) We increased SNP-based prediction accuracy of quantitative eye colour. Our findings exemplify that precise quantification using the perceived biological basis of pigmentation leads to enhanced genetic association and prediction of eye colour. We expect our approach to deliver new pigmentation genes when applied to genome-wide association testing.

Defective pigment granule biogenesis and aberrant behavior caused by mutations in the Drosophila AP-3beta adaptin gene ruby.

PubMed Central

Kretzschmar, D; Poeck, B; Roth, H; Ernst, R; Keller, A; Porsch, M; Strauss, R; Pflugfelder, G O

2000-01-01

Lysosomal protein trafficking is a fundamental process conserved from yeast to humans. This conservation extends to lysosome-like organelles such as mammalian melanosomes and insect eye pigment granules. Recently, eye and coat color mutations in mouse (mocha and pearl) and Drosophila (garnet and carmine) were shown to affect subunits of the heterotetrameric adaptor protein complex AP-3 involved in vesicle trafficking. Here we demonstrate that the Drosophila eye color mutant ruby is defective in the AP-3beta subunit gene. ruby expression was found in retinal pigment and photoreceptor cells and in the developing central nervous system. ruby mutations lead to a decreased number and altered size of pigment granules in various cell types in and adjacent to the retina. Humans with lesions in the related AP-3betaA gene suffer from Hermansky-Pudlak syndrome, which is caused by defects in a number of lysosome-related organelles. Hermansky-Pudlak patients have a reduced skin pigmentation and suffer from internal bleeding, pulmonary fibrosis, and visual system malfunction. The Drosophila AP-3beta adaptin also appears to be involved in processes other than eye pigment granule biogenesis because all ruby allele combinations tested exhibited defective behavior in a visual fixation paradigm. PMID:10790396

Novel quantitative pigmentation phenotyping enhances genetic association, epistasis, and prediction of human eye colour

PubMed Central

Wollstein, Andreas; Walsh, Susan; Liu, Fan; Chakravarthy, Usha; Rahu, Mati; Seland, Johan H.; Soubrane, Gisèle; Tomazzoli, Laura; Topouzis, Fotis; Vingerling, Johannes R.; Vioque, Jesus; Böhringer, Stefan; Fletcher, Astrid E.; Kayser, Manfred

2017-01-01

Success of genetic association and the prediction of phenotypic traits from DNA are known to depend on the accuracy of phenotype characterization, amongst other parameters. To overcome limitations in the characterization of human iris pigmentation, we introduce a fully automated approach that specifies the areal proportions proposed to represent differing pigmentation types, such as pheomelanin, eumelanin, and non-pigmented areas within the iris. We demonstrate the utility of this approach using high-resolution digital eye imagery and genotype data from 12 selected SNPs from over 3000 European samples of seven populations that are part of the EUREYE study. In comparison to previous quantification approaches, (1) we achieved an overall improvement in eye colour phenotyping, which provides a better separation of manually defined eye colour categories. (2) Single nucleotide polymorphisms (SNPs) known to be involved in human eye colour variation showed stronger associations with our approach. (3) We found new and confirmed previously noted SNP-SNP interactions. (4) We increased SNP-based prediction accuracy of quantitative eye colour. Our findings exemplify that precise quantification using the perceived biological basis of pigmentation leads to enhanced genetic association and prediction of eye colour. We expect our approach to deliver new pigmentation genes when applied to genome-wide association testing. PMID:28240252

Iridescence and spectral filtering of the gyroid-type photonic crystals in Parides sesostris wing scales

PubMed Central

Wilts, Bodo D.; Michielsen, Kristel; De Raedt, Hans; Stavenga, Doekele G.

2012-01-01

The cover scales on the wing of the Emerald-patched Cattleheart butterfly, Parides sesostris, contain gyroid-type biological photonic crystals that brightly reflect green light. A pigment, which absorbs maximally at approximately 395 nm, is immersed predominantly throughout the elaborate upper lamina. This pigment acts as a long-pass filter shaping the reflectance spectrum of the underlying photonic crystals. The additional effect of the filtering is that the spatial distribution of the scale reflectance is approximately angle-independent, leading to a stable wing pattern contrast. The spectral tuning of the original reflectance is verified by photonic band structure modelling. PMID:24098853

[Multiple retinal pigment epithelial detachments: a case report].

PubMed

González-Escobar, A B; González de Gor-Crooke, J L; López-Egea-Bueno, M A; García-Campos, J M

2014-05-01

A 47 year-old female who presented with a bilateral idiopathic multiple pigment epithelial detachment (PED) in a routine visit. This pathology is shown as a rare clinical manifestation, where the outcome is resolution of localized atrophy of the pigment epithelium, with a good functional prognosis. PED is a common clinical manifestation in several chorioretinal diseases, particularly in macular degeneration associated with age. Idiopathic PED can be considered as a kind of central type II serous chorioretinopathy. Fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) are complementary tests to study the number, extension, and nature of these PED. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Microarray Analysis of Iris Gene Expression in Mice with Mutations Influencing Pigmentation

PubMed Central

Trantow, Colleen M.; Cuffy, Tryphena L.; Fingert, John H.; Kuehn, Markus H.

2011-01-01

Purpose. Several ocular diseases involve the iris, notably including oculocutaneous albinism, pigment dispersion syndrome, and exfoliation syndrome. To screen for candidate genes that may contribute to the pathogenesis of these diseases, genome-wide iris gene expression patterns were comparatively analyzed from mouse models of these conditions. Methods. Iris samples from albino mice with a Tyr mutation, pigment dispersion–prone mice with Tyrp1 and Gpnmb mutations, and mice resembling exfoliation syndrome with a Lyst mutation were compared with samples from wild-type mice. All mice were strain (C57BL/6J), age (60 days old), and sex (female) matched. Microarrays were used to compare transcriptional profiles, and differentially expressed transcripts were described by functional annotation clustering using DAVID Bioinformatics Resources. Quantitative real-time PCR was performed to validate a subset of identified changes. Results. Compared with wild-type C57BL/6J mice, each disease context exhibited a large number of statistically significant changes in gene expression, including 685 transcripts differentially expressed in albino irides, 403 in pigment dispersion–prone irides, and 460 in exfoliative-like irides. Conclusions. Functional annotation clusterings were particularly striking among the overrepresented genes, with albino and pigment dispersion–prone irides both exhibiting overall evidence of crystallin-mediated stress responses. Exfoliative-like irides from mice with a Lyst mutation showed overall evidence of involvement of genes that influence immune system processes, lytic vacuoles, and lysosomes. These findings have several biologically relevant implications, particularly with respect to secondary forms of glaucoma, and represent a useful resource as a hypothesis-generating dataset. PMID:20739468

Lamp system for uniform semiconductor wafer heating

DOEpatents

Zapata, Luis E.; Hackel, Lloyd

2001-01-01

A lamp system with a very soft high-intensity output is provided over a large area by water cooling a long-arc lamp inside a diffuse reflector of polytetrafluorethylene (PTFE) and titanium dioxide (TiO.sub.2) white pigment. The water is kept clean and pure by a one micron particulate filter and an activated charcoal/ultraviolet irradiation system that circulates and de-ionizes and biologically sterilizes the coolant water at all times, even when the long-arc lamp is off.

Time-Dependent ATR-FTIR Spectroscopic Studies on Fatty Acid Diffusion and the Formation of Metal Soaps in Oil Paint Model Systems.

PubMed

Baij, Lambert; Hermans, Joen J; Keune, Katrien; Iedema, Piet

2018-06-18

The formation of metal soaps (metal complexes of saturated fatty acids) is a serious problem affecting the appearance and structural integrity of many oil paintings. Tailored model systems for aged oil paint and time-dependent attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy were used to study the diffusion of palmitic acid and subsequent metal soap crystallization. The simultaneous presence of free saturated fatty acids and polymer-bound metal carboxylates leads to rapid metal soap crystallization, following a complex mechanism that involves both acid and metal diffusion. Solvent flow, water, and pigments all enhance metal soap crystallization in the model systems. These results contribute to the development of paint cleaning strategies, a better understanding of oil paint degradation, and highlight the potential of time-dependent ATR-FTIR spectroscopy for studying dynamic processes in polymer films. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

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

PubMed

Rodriguez-Fernandez, Imilce A; Dell'Angelica, Esteban C

2015-01-01

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

Using Dermoscopic Criteria and Patient-Related Factors for the Management of Pigmented Melanocytic Nevi

PubMed Central

Zalaudek, Iris; Docimo, Giovanni; Argenziano, Giuseppe

2010-01-01

Objective: To review recent dermoscopy studies that provide new insights into the evolution of nevi and their patterns of pigmentation as they contribute to the diagnosis of nevi and the management of pigmented melanocytic nevi. Data Sources: Data for this article were identified by searching the English and German literature by Medline and Journals@Ovid search for the period 1950 to January 2009. Study Selection: The following relevant terms were used: dermoscopy, dermatoscopy, epiluminescence microscopy (ELM), surface microscopy, digital dermoscopy, digital dermatoscopy, digital epiluminescence microscopy, digital surface microscopy, melanocytic skin lesion, nevi, and pigmented skin lesions. There were no exclusion criteria. Data Synthesis: The dermoscopic diagnosis of nevi relies on the following 4 criteria (each of which is characterized by 4 variables): (1) color (black, brown, gray, and blue); (2) pattern (globular, reticular, starburst, and homogeneous blue pattern); (3) pigment distribution (multifocal, central, eccentric, and uniform); and (4) special sites (face, acral areas, nail, and mucosa). In addition, the following 6 factors related to the patient might influence the pattern of pigmentation of the individual nevi: age, skin type, history of melanoma, UV exposure, pregnancy, and growth dynamics. Conclusions: The 4×4×6 “rule” may help clinicians remember the basic dermoscopic criteria of nevi and the patient-related factors influencing their patterns. Dermoscopy is a useful technique for diagnosing melanocytic nevi, but the clinician should take additional factors into consideration to optimize the management of cases of pigmented lesions. PMID:19620566

Biomass productivities in wild type and pigment mutant of Cyclotella sp. (Diatom).

PubMed

Huesemann, Michael H; Hausmann, Tom S; Bartha, Richard; Aksoy, M; Weissman, Joseph C; Benemann, John R

2009-06-01

Microalgae are expected to play a significant role in greenhouse gas mitigation because they can utilize CO(2) from power plant flue gases directly while producing a variety of renewable carbon-neutral biofuels. In order for such a microalgal climate change mitigation strategy to become economically feasible, it will be necessary to significantly improve biomass productivities. One approach to achieve this objective is to reduce, via mutagenesis, the number of light-harvesting pigments, which, according to theory, should significantly improve the light utilization efficiency, primarily by increasing the light intensity at which photosynthesis saturates (I(s)). Employing chemical (ethylmethylsulfonate) and UV mutagenesis of a wild-type strain of the diatom Cyclotella, approximately 10,000 pigment mutants were generated, and two of the most promising ones (CM1 and CM1-1) were subjected to further testing in both laboratory cultures and outdoor ponds. Measurements of photosynthetic oxygen production rates as a function of light intensity (i.e., P-I curves) of samples taken from laboratory batch cultures during the exponential and linear growth phase indicated that the light intensity at which photosynthesis saturates (I(s)) was two to three times greater in the pigment mutant CM1-1 than in the wild type, i.e., 355-443 versus 116-169 mumol/m(2) s, respectively. While theory, i.e., the Bush equation, predicts that such a significant gain in I(s) should increase light utilization efficiencies and thus biomass productivities, particularly at high light intensities, no improvements in biomass productivities were observed in either semi-continuous laboratory cultures or outdoor ponds. In fact, the maximum biomass productivity in semi-continuous laboratory culture was always greater in the wild type than in the mutant, namely 883 versus 725 mg/L day, respectively, at low light intensity (200 micromol/m(2) s) and 1,229 versus 1,043 mg/L day, respectively, at high light intensity (1,000 micromol/m(2) s). Similarly, the biomass productivities measured in outdoor ponds were significantly lower for the mutant than for the wild type. Given that these mutants have not been completely characterized in these initial studies, the exact reasons for their poor performance are not known. Most likely, it is possible that the mutation procedure affected other photosynthetic or metabolic processes. This hypothesis was partially validated by the observation that the pigment mutant had a longer lag period following inoculation, a lower maximum specific growth rate, and poorer stability than the wild type.

Pigment pattern in jaguar/obelix zebrafish is caused by a Kir7.1 mutation: implications for the regulation of melanosome movement.

PubMed

Iwashita, Motoko; Watanabe, Masakatsu; Ishii, Masaru; Chen, Tim; Johnson, Stephen L; Kurachi, Yoshihisa; Okada, Norihiro; Kondo, Shigeru

2006-11-24

Many animals have a variety of pigment patterns, even within a species, and these patterns may be one of the driving forces of speciation. Recent molecular genetic studies on zebrafish have revealed that interaction among pigment cells plays a key role in pattern formation, but the mechanism of pattern formation is unclear. The zebrafish jaguar/obelix mutant has broader stripes than wild-type fish. In this mutant, the development of pigment cells is normal but their distribution is altered, making these fish ideal for studying the process of pigment pattern formation. Here, we utilized a positional cloning method to determine that the inwardly rectifying potassium channel 7.1 (Kir7.1) gene is responsible for pigment cell distribution among jaguar/obelix mutant fish. Furthermore, in jaguar/obelix mutant alleles, we identified amino acid changes in the conserved region of Kir7.1, each of which affected K(+) channel activity as demonstrated by patch-clamp experiments. Injection of a bacterial artificial chromosome containing the wild-type Kir7.1 genomic sequence rescued the jaguar/obelix phenotype. From these results, we conclude that mutations in Kir7.1 are responsible for jaguar/obelix. We also determined that the ion channel function defect of melanophores expressing mutant Kir7.1 altered the cellular response to external signals. We discovered that mutant melanophores cannot respond correctly to the melanosome dispersion signal derived from the sympathetic neuron and that melanosome aggregation is constitutively activated. In zebrafish and medaka, it is well known that melanosome aggregation and subsequent melanophore death increase when fish are kept under constant light conditions. These observations indicate that melanophores of jaguar/obelix mutant fish have a defect in the signaling pathway downstream of the alpha2-adrenoceptor. Taken together, our results suggest that the cellular defect of the Kir7.1 mutation is directly responsible for the pattern change in the jaguar/obelix mutant.

Pigment Pattern in jaguar/obelix Zebrafish Is Caused by a Kir7.1 Mutation: Implications for the Regulation of Melanosome Movement

PubMed Central

Iwashita, Motoko; Watanabe, Masakatsu; Ishii, Masaru; Chen, Tim; Johnson, Stephen L; Kurachi, Yoshihisa; Okada, Norihiro; Kondo, Shigeru

2006-01-01

Many animals have a variety of pigment patterns, even within a species, and these patterns may be one of the driving forces of speciation. Recent molecular genetic studies on zebrafish have revealed that interaction among pigment cells plays a key role in pattern formation, but the mechanism of pattern formation is unclear. The zebrafish jaguar/obelix mutant has broader stripes than wild-type fish. In this mutant, the development of pigment cells is normal but their distribution is altered, making these fish ideal for studying the process of pigment pattern formation. Here, we utilized a positional cloning method to determine that the inwardly rectifying potassium channel 7.1 (Kir7.1) gene is responsible for pigment cell distribution among jaguar/obelix mutant fish. Furthermore, in jaguar/obelix mutant alleles, we identified amino acid changes in the conserved region of Kir7.1, each of which affected K+ channel activity as demonstrated by patch-clamp experiments. Injection of a bacterial artificial chromosome containing the wild-type Kir7.1 genomic sequence rescued the jaguar/obelix phenotype. From these results, we conclude that mutations in Kir7.1 are responsible for jaguar/obelix. We also determined that the ion channel function defect of melanophores expressing mutant Kir7.1 altered the cellular response to external signals. We discovered that mutant melanophores cannot respond correctly to the melanosome dispersion signal derived from the sympathetic neuron and that melanosome aggregation is constitutively activated. In zebrafish and medaka, it is well known that melanosome aggregation and subsequent melanophore death increase when fish are kept under constant light conditions. These observations indicate that melanophores of jaguar/obelix mutant fish have a defect in the signaling pathway downstream of the α2-adrenoceptor. Taken together, our results suggest that the cellular defect of the Kir7.1 mutation is directly responsible for the pattern change in the jaguar/obelix mutant. PMID:17121467

CAPN3, DCT, MLANA and TYRP1 are overexpressed in skin of vitiligo vulgaris Mexican patients.

PubMed

Salinas-Santander, Mauricio; Trevino, Víctor; De la Rosa-Moreno, Eduardo; Verduzco-Garza, Bárbara; Sánchez-Domínguez, Celia N; Cantú-Salinas, Cristina; Ocampo-Garza, Jorge; Lagos-Rodríguez, Armando; Ocampo-Candiani, Jorge; Ortiz-López, Rocio

2018-03-01

Vitiligo is a disorder causing skin depigmentation, in which several factors have been proposed for its pathogenesis: Environmental, genetic and biological aspects of melanocytes, even those of the surrounding keratinocytes. However, the lack of understanding of the mechanisms has complicated the task of predicting the development and progression. The present study used microarray analysis to characterize the transcriptional profile of skin from Vitiligo Vulgaris (VV) patients and the identified transcripts were validated using targeted high-throughput RNA sequencing in a broader set of patients. For microarrays, mRNA was taken from 20 skin biopsies of 10 patients with VV (pigmented and depigmented skin biopsy of each), and 5 biopsies of healthy subjects matched for age and sex were used as a control. A signature was identified that contains the expression pattern of 722 genes between depigmented vitiligo skin vs. healthy control, 1,108 between the pigmented skin of vitiligo vs. healthy controls and 1,927 between pigmented skin, depigmented vitiligo and healthy controls (P<0.05; false discovery rate, <0.1). When comparing the pigmented and depigmented skin of patients with vitiligo, which reflects the real difference between both skin types, 5 differentially expressed genes were identified and further validated in 45 additional VV patients by RNA sequencing. This analysis showed significantly higher RNA levels of calpain-3, dopachrome tautomerase, melan-A and tyrosinase-related protein-1 genes. The data revealed that the pigmented skin of vitiligo is already affected at the level of gene expression and that the main differences between pigmented and non-pigmented skin are explained by the expression of genes associated with pigment metabolism.

Pigmentary Markers in Danes – Associations with Quantitative Skin Colour, Nevi Count, Familial Atypical Multiple-Mole, and Melanoma Syndrome

PubMed Central

Johansen, Peter; Andersen, Jeppe Dyrberg; Madsen, Linnea Nørgård; Ullum, Henrik; Glud, Martin; Børsting, Claus; Gniadecki, Robert; Morling, Niels

2016-01-01

To investigate whether pigmentation genes involved in the melanogenic pathway (melanogenesis) contributed to melanoma predisposition, we compared pigmentary genetics with quantitative skin pigmentation measurements, the number of atypical nevi, the total nevus count, and the familial atypical multiple mole and melanoma (FAMMM) syndrome. We typed 32 pigmentary SNP markers and sequenced MC1R in 246 healthy individuals and 116 individuals attending periodic control for malignant melanoma development, 50 of which were diagnosed with FAMMM. It was observed that individuals with any two grouped MC1R variants (missense, NM_002386:c. 456C > A (p.TYR152*), or NM_002386:c.83_84insA (p.Asn29Glnfs*14) had significantly (p<0.001) lighter skin pigmentation of the upper-inner arm than those with none or one MC1R variant. We did not observe any significant association of the MC1R variants with constitutive pigmentation measured on the buttock area. We hypothesize that the effect of MC1R variants on arm pigmentation is primarily reflecting the inability to tan when subjected to UVR. A gender specific effect on skin pigmentation was also observed, and it was found that the skin pigmentation of females on average were darker than that of males (p<0.01). We conclude that MC1R variants are associated with quantitative skin colour in a lightly pigmented Danish population. We did not observe any association between any pigmentary marker and the FAMMM syndrome. We suggest that the genetics of FAMMM is not related to the genetics of the pigmentary pathway. PMID:26938746

Spectrophotometric Method for Differentiation of Human Skin Melanoma. II. Diagnostic Characteristics

NASA Astrophysics Data System (ADS)

Petruk, V. G.; Ivanov, A. P.; Kvaternyuk, S. M.; Barunb, V. V.

2016-05-01

Experimental data on the spectral dependences of the optical diffuse reflection coefficient for skin from different people with melanoma or nevus are presented in the form of the probability density of the diffuse reflection coefficient for the corresponding pigmented lesions. We propose a noninvasive technique for differentiating between malignant and benign tumors, based on measuring the diffuse reflection coefficient for a specific patient and comparing the value obtained with a pre-set threshold. If the experimental result is below the threshold, then it is concluded that the person has melanoma; otherwise, no melanoma is present. As an example, we consider the wavelength 870 nm. We determine the risk of malignant transformation of a nevus (its transition to melanoma) for different measured diffuse reflection coefficients. We have studied the errors in the method, its operating characteristics and probability characteristics as the threshold diffuse reflection coefficient is varied. We find that the diagnostic confidence, sensitivity, specificity, and effectiveness (accuracy) parameters are maximum (>0.82) for a threshold of 0.45-0.47. The operating characteristics for the proposed technique exceed the corresponding parameters for other familiar optical approaches to melanoma diagnosis. Its distinguishing feature is operation at only one wavelength, and consequently implementation of the experimental technique is simplified and made less expensive.

Role of carotenoids in first positive phototropism of etiolated Arabidopsis thaliana seedlings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orbovic, V.; Poff, K.L.

1991-05-01

A mutant of Arabidopsis thaliana, chosen for is pale cotyledon phenotype in dark grown material, has been obtained from Klaus Apel (ETH-Zentrum, Zurich, Switzerland). Fluence response curves for this putative carotenoidless mutant and its wild-type parent have been measured. The shape of the fluence response curve for the pale mutant is similar to that of its wild-type parent. However, the amplitude of curvature by the mutant is considerably lower than curvature of the wild-type. If the amplitude of the curvature is enhanced with a red light pre-irradiation, peaks of the two photoreceptor pigments, P{sub I} and P{sub II} can bemore » seen in both the pale mutant and its wild-type parent. Based on these data, the authors conclude that neither photoreceptor pigment is altered in the pale mutant.« less

Canine goniodysgenesis-related glaucoma: a morphologic review of 100 cases looking at inflammation and pigment dispersion.

PubMed

Reilly, Christopher M; Morris, Rebecca; Dubielzig, Richard R

2005-01-01

To investigate the role of pigment dispersion and inflammation in the pathogenesis of goniodysgenesis-related glaucoma (GDRG). Cases of GDRG were selected when the duration of the disease was specified and there was not any confounding pathology. Cases were grouped into < or = 7-day (acute), and > 7-day (chronic) durations, based on the time required to effect end-stage retinal damage. Acute cases were further divided into < 4-day and 4-7-day groups to assess peracute changes. Slides were evaluated for four individual signs of pigment dispersion: segmental loss of posterior iris pigment epithelium, clumping of posterior iris pigment epithelium, pigmented cells in the trabecular meshwork or anterior chamber and preferential settling of pigmented cells in the ventral aspect of the iridocorneal angle. Slides were also evaluated for the presence of neutrophils and/or lymphoplasmacytic cells in the trabecular meshwork (TM). Differences between groups were analyzed statistically. Of 100 cases evaluated, 34 were < or = 7-days (acute) (14 < 4-day and 20 4-7-day) and 66 were > 7-days (chronic) in duration. Of all globes examined, 96% had at least one sign of pigment dispersion, with no significant difference between groups. Two or more signs of pigment dispersion were present in 76% of all globes. The 4-7-day group was significantly more likely than the < 4-day group to have at least two signs. The difference was not significant between < or = 7- and > 7-day groups. Neutrophils were present in the TM of 86% of < 4-day and 50% of 4-7-day cases. Cases in the < or = 7-day group were significantly more [corrected] likely than > 7-day cases to have neutrophils in the TM, with 65% and 17% [corrected] positive cases, respectively. Lymphoplasmacytic inflammation was present in 53% of all cases, with no significant difference between groups. Cases in the < or = 7-day group were significantly more likely than > 7-day cases to have both types of inflammation. Our results indicate that both acute inflammation and pigment dispersion may be key factors in the pathogenesis of GDRG. Pigment dispersion is prevalent at all time points and increases during the first 7 days. The finding of iris pigment epithelial loss supports the theory that pupillary block associated with iris-lens touching may be important in the pathogenesis of GDRG.

Deposits in artificial corneas: risk factors and prevention.

PubMed

Hicks, Celia R; Chirila, Traian V; Werner, Liliana; Crawford, Geoffrey J; Apple, David J; Constable, Ian J

2004-04-01

To identify risk factors for calcium deposition and pigmented staining within AlphaCor artificial corneas. Retrospective analysis of data from 72 AlphaCor implantations was conducted. Histological analysis of explants was performed. Eight cases of either intraoptic calcium or pigment deposition occurred in AlphaCor patients between 2.5 and 21 months after implantation. Four cases had diffuse white deposits, confirmed to be calcium and associated with prior coadministration of topical steroids and beta-blockers. The other four cases had brown deposits, associated with cigarette smoking and topical levobunolol. These findings led to changes in patient management protocols, surgeon training and patient information so as to minimize the risk of further occurrences. No further cases of white deposition have occurred after warning surgeons of the risk associated with certain topical therapy combinations. The risk of brown staining may be difficult to remove completely as it appears that environmental exposure to chemicals may cause deposition in addition to personal smoking habits and topical medications.

Optical Coherence Tomography Angiography of Pigmented Paravenous Retinochoroidal Atrophy.

PubMed

Cicinelli, Maria Vittoria; Giuffrè, Chiara; Rabiolo, Alessandro; Parodi, Maurizio Battaglia; Bandello, Francesco

2018-05-01

A 58-year-old man with bilateral pigmented paravenous retinochoroidal atrophy (PPRCA) associated with macular coloboma in the right eye underwent color fundus photography and fundus autofluorescence with the California ultra-widefield retinal imaging system (Optos, Dunfermline, UK), spectral-domain optical coherence tomography (SD-OCT) (Heidelberg Spectralis HRA + OCT; Heidelberg Engineering, Heidelberg, Germany), and en face OCT angiography (OCTA) (AngioPlex, Cirrus HD-OCT 5000; Carl Zeiss Meditec, Dublin, CA). The patient presented with a visual acuity of counting fingers in the right eye and 20/32 in the left eye. Fundus examination and SD-OCT showed typical PPRCA alterations in both eyes and a macular coloboma in the right eye. The OCTA showed relative sparing of the retinal capillary plexuses, with diffuse defects in the choriocapillaris. The authors concluded OCTA imaging of PPRCA suggests more insights of the pathogenesis of this disease, showing that the disease primarily affects the choroidal vascular network, with a relative sparing of the retinal vasculature. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:381-383.]. Copyright 2018, SLACK Incorporated.

Disentangling the Trichoderma viridescens complex.

PubMed

Jaklitsch, W M; Samuels, G J; Ismaiel, A; Voglmayr, H

2013-12-01

Trichoderma viridescens is recognised as a species complex. Multigene analyses based on the translation elongation factor 1-alpha encoding gene (tef1), a part of the rpb2 gene, encoding the second largest RNA polymerase subunit and the larger subunit of ATP citrate lyase (acl1) reveals 13 phylogenetic species with little or no phenotypic differentiation. This is the first use of acl1 in Trichoderma phylogenetics. The typification of T. viridescens s.str. is clarified and Hypocrea viridescens is replaced by the new name T. paraviridescens. Besides these two species, eleven are phylogenetically recognised and T. olivascens, T. viridarium, T. virilente, T. trixiae, T. viridialbum, T. appalachiense, T. neosinense, T. composticola, T. nothescens and T. sempervirentis are formally described and illustrated. Several species produce yellow diffusing pigment on cornmeal dextrose agar, particularly after storage at 15 °C, while T. olivascens is characterised by the formation of an olivaceous pigment. The results are compared with earlier publications on this group of species.

Separation of polar betalain pigments from cacti fruits of Hylocereus polyrhizus by ion-pair high-speed countercurrent chromatography.

PubMed

Wybraniec, Sławomir; Stalica, Paweł; Jerz, Gerold; Klose, Bettina; Gebers, Nadine; Winterhalter, Peter; Spórna, Aneta; Szaleniec, Maciej; Mizrahi, Yosef

2009-10-09

Polar betacyanin pigments together with betaxanthins from ripe cactus fruits of Hylocereus polyrhizus (Cactaceae) were fractionated by means of preparative ion-pair high-speed countercurrent chromatography (IP-HSCCC) also using the elution-extrusion (EE) approach for a complete pigment recovery. HSCCC separations were operated in the classical 'head-to-tail' mode with an aqueous mobile phase. Different CCC solvent systems were evaluated in respect of influence and effectiveness of fractionation capabilities to separate the occurring pigment profile of H. polyrhizus. For that reason, the additions of two different volatile ion-pair forming perfluorinated carboxylic acids (PFCA) were investigated. For a direct comparison, five samples of Hylocereus pigment extract were run on preparative scale (900 mg) in 1-butanol-acetonitrile-aqueous TFA 0.7% (5:1:6, v/v/v) and the modified systems tert.-butyl methyl ether-1-butanol-acetonitrile-aqueous PFCA (2:2:1:5, v/v/v/v) using 0.7% and 1.0% trifluoroacetic acid (TFA) or heptafluorobutyric acid (HFBA) in the aqueous phase, respectively. The chemical affinity to the organic stationary CCC solvent phases and in consequence the retention of these highly polar betalain pigments was significantly increased by the use of the more lipophilic fluorinated ion-pair reagent HFBA instead of TFA. The HFBA additions separated more effectively the typical cacti pigments phyllocactin and hylocerenin from betanin as well as their iso-forms. Unfortunately, similar K(D) ratios and selectivity factors alpha around 1.0-1.1 in all tested solvent systems proved that the corresponding diastereomers, 15S-type pigments cannot be resolved from the 15R-epimers (iso-forms). Surprisingly, additions of the stronger ion-pair reagent (HFBA) resulted in a partial separation of hylocerenin from phyllocactin which were not resolved in the other solvent systems. The pigments were detected by means of HPLC-DAD and HPLC-electrospray ionization-MS using also authentic reference materials.

Isolation and molecular identification of planctomycete bacteria from postlarvae of the giant tiger prawn, Penaeus monodon.

PubMed Central

Fuerst, J A; Gwilliam, H G; Lindsay, M; Lichanska, A; Belcher, C; Vickers, J E; Hugenholtz, P

1997-01-01

Bacteria phenotypically resembling members of the phylogenetically distinct planctomycete group of the domain Bacteria were isolated from postlarvae of the giant tiger prawn, Penaeus monodon. A selective medium designed in the light of planctomycete antibiotic resistance characteristics was used for this isolation. Planctomycetes were isolated from both healthy and monodon baculovirus-infected prawn postlarvae. The predominant colony type recovered from postlarvae regardless of viral infection status was nonpigmented. Other, less commonly observed types were pink or orange pigmented. A planctomycete-specific 16S rRNA-directed probe was designed and used to screen the isolates for their identity as planctomycetes prior to molecular phylogenetic characterization. 16S rRNA genes from nine prawn isolates together with two planctomycete reference strains (Planctomyces brasiliensis and Gemmata obscuriglobus) were sequenced and compared with reference sequences from the planctomycetes and other members of the domain Bacteria. Phylogenetic analyses and sequence signatures of the 16S rRNA genes demonstrated that the prawn isolates were members of the planctomycete group. Five representatives of the predominant nonpigmented colony type were members of the Pirellula group within the planctomycetes, as were three pink-pigmented colony type representatives. Homology values and tree topology indicated that representatives of the nonpigmented and pink-pigmented colony types formed two discrete clusters within the Pirellula group, not identical to any known Pirellula species. A sole representative of the orange colony type was a member of the Planctomyces group, virtually identical in 16S rDNA sequence to P. brasiliensis, and exhibited distinctive morphology. PMID:8979353

Two-photon absorption and transient photothermal imaging of pigments in tissues

NASA Astrophysics Data System (ADS)

Ye, Tong; Fu, Dan; Matthews, Thomas E.; Hong, Lian; Simon, John D.; Warren, Warren S.

2008-02-01

As a main pigment in skin tissues, melanin plays an important role in photo-protecting skin from UV radiation. However, melanogenesis may be altered due to disease or environmental factors; for example, sun exposure may cause damage and mutation of melanocytes and induce melanoma. Imaging pigmentation changes may provide invaluable information to catch the malignant transformation in its early stage and in turn improve the prognosis of patients. We have demonstrated previously that transmission mode, two-photon, one- or two-color absorption microscopy could provide remarkable contrast in imaging melanin in skin. In this report we demonstrate significantly improved sensitivity, so that we are now able to image in epi-mode (or back reflection) in two-photon absorption. This improvement makes possible for us to characterize the different types of pigmentation on the skin in vivo at virtually any location. Another finding is that we can also image transient photothermal dynamics due to the light absorption of melanin. By carefully choosing excitation and probe wavelengths, we might be able to image melanin in different structures under different micro-environments in skin, which could provide useful photochemical and photophysical insights in understanding how pigments are involved in photoprotection and photodamage of cells.

Discovery of novel piperonyl derivatives as diapophytoene desaturase inhibitors for the treatment of methicillin-, vancomycin- and linezolid-resistant Staphylococcus aureus infections.

PubMed

Wei, Hanwen; Mao, Fei; Ni, Shuaishuai; Chen, Feifei; Li, Baoli; Qiu, Xiaoxia; Hu, Linghao; Wang, Manjiong; Zheng, Xinyu; Zhu, Jin; Lan, Lefu; Li, Jian

2018-02-10

Inhibition of S. aureus diapophytoene desaturase (CrtN) could serve as an alternative approach for addressing the tricky antibiotic resistance by blocking the biosynthesis of carotenoid pigment which shields the bacterium from host oxidant killing. In this study, we designed and synthesized 44 derivatives with piperonyl scaffold targeting CrtN and the structure-activity relationships (SARs) were examined extensively to bring out the discovery of 21b with potent efficacy and better hERG safety profile compared to the first class CrtN inhibitor benzocycloalkane derivative 2. Except the excellent pigment inhibitory activity against wild-type S. aureus, 21b also showed excellent pigment inhibition against four pigmented MRSA strains. In addition, H 2 O 2 killing and human whole blood killing assays proved 21b could sensitize S. aureus to be killed under oxidative stress conditions. Notably, the murine study in vivo validated the efficacy of 21b against pigmented S. aureus Newman, vancomycin-intermediate S. aureus Mu50 and linezolid-resistant S. aureus NRS271. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Single crystal X-ray structure of the artists' pigment zinc yellow

NASA Astrophysics Data System (ADS)

Simonsen, Kim Pilkjær; Christiansen, Marie Bitsch; Vinum, Morten Gotthold; Sanyova, Jana; Bendix, Jesper

2017-08-01

The artists' pigment zinc yellow is in general described as a complex potassium zinc chromate with the empirical formula 4ZnCrO4·K2O·3H2O. Even though the pigment has been in use since the second half of the 19th century also in large-scale industrial applications, the exact structure had hitherto been unknown. In this work, zinc yellow was synthesised by precipitation from an aqueous solution of zinc nitrate and potassium chromate under both neutral and basic conditions, and the products were compared with the pigment used in industrial paints. Analyses by Raman microscopy (MRS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and powder X-ray diffraction (PXRD), showed that the synthesised products and the industrial pigment were identical. Single-crystal X-ray crystallography determined the structure of zinc yellow as KZn2(CrO4)2(H2O)(OH) or as KZn2(CrO4)2(H3O2) emphasizing the μ-H3O2- moiety. Notably, the zinc yellow is isostructural to the recently structurally characterized cadmium analog and both belong to the natrochalcite structure type.

Liquid-liquid microextraction of synthetic pigments in beverages using a hydrophobic deep eutectic solvent.

PubMed

Zhu, Shuqiang; Zhou, Jia; Jia, Hongfang; Zhang, Haixia

2018-03-15

A method was developed for the determination of eight synthetic pigments in beverage samples by liquid-liquid microextraction followed by high performance liquid chromatography. Using hydrophobic deep eutectic solvent (DES) as the microextraction solvent, several key parameters were optimized, including the type and volume of the hydrophobic DES, pH value, vortex time and salt content. Detection limits were in the range 0.016-1.12 ng/mL, recoveries were in the range 74.5-102.5% and relative standard deviations were <5.4%. The method is simple, green and practical, and could be applied to the extraction and determination of synthetic pigments in beverages. Copyright © 2017 Elsevier Ltd. All rights reserved.

Capabilities and limitations of handheld Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) for the analysis of colourants and binders in 20th-century reverse paintings on glass

NASA Astrophysics Data System (ADS)

Steger, Simon; Stege, Heike; Bretz, Simone; Hahn, Oliver

2018-04-01

A non-invasive method has been carried out to show the capabilities and limitations of Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) for identifying of colourants and binders in modern reverse glass paintings. For this purpose, the reverse glass paintings "Zwei Frauen am Tisch" (1920-22), "Bäume" (1946) (both by Heinrich Campendonk), "Lofoten" (1933) (Edith Campendonk-van Leckwyck) and "Ohne Titel" (1954) (Marianne Uhlenhuth), were measured. In contrast to other techniques (e.g. panel and mural painting), the paint layers are applied in reverse succession. In multi-layered paint systems, the front paint layer may no longer be accessible. The work points out the different spectral appearance of a given substance (gypsum, basic lead white) in reverse glass paintings. However, inverted bands, band overlapping and derivative-shaped spectral features can be interpreted by comparing the spectra from the paintings with spectra from pure powders and pigment/linseed oil mock-ups. Moreover, the work focuses on this method's capabilities in identifying synthetic organic pigments (SOP). Reference spectra of three common SOP (PG7, PY1, PR83) were obtained from powders and historical colour charts. We identified PR83 and PY1 in two reverse glass paintings, using the measured reference spectra. The recorded DRIFTS spectra of pure linseed oil, gum Arabic, mastic, polyvinyl acetate resin and bees wax can be used to classify the binding media of the measured paintings.

Higher iridescent-to-pigment optical effect in flowers facilitates learning, memory and generalization in foraging bumblebees.

PubMed

de Premorel, Géraud; Giurfa, Martin; Andraud, Christine; Gomez, Doris

2017-10-25

Iridescence-change of colour with changes in the angle of view or of illumination-is widespread in the living world, but its functions remain poorly understood. The presence of iridescence has been suggested in flowers where diffraction gratings generate iridescent colours. Such colours have been suggested to serve plant-pollinator communication. Here we tested whether a higher iridescence relative to corolla pigmentation would facilitate discrimination, learning and retention of iridescent visual targets. We conditioned bumblebees ( Bombus terrestris ) to discriminate iridescent from non-iridescent artificial flowers and we varied iridescence detectability by varying target iridescent relative to pigment optical effect. We show that bees rewarded on targets with higher iridescent relative to pigment effect required fewer choices to complete learning, showed faster generalization to novel targets exhibiting the same iridescence-to-pigment level and had better long-term memory retention. Along with optical measurements, behavioural results thus demonstrate that bees can learn iridescence-related cues as bona fide signals for flower reward. They also suggest that floral advertising may be shaped by competition between iridescence and corolla pigmentation, a fact that has important evolutionary implications for pollinators. Optical measurements narrow down the type of cues that bees may have used for learning. Beyond pollinator-plant communication, our experiments help understanding how receivers influence the evolution of iridescence signals generated by gratings. © 2017 The Author(s).

Thickness, medullation and growth rate of female scalp hair are subject to significant variation according to pigmentation and scalp location during ageing.

PubMed

Van Neste, Dominique

2004-01-01

The biological importance and/or significance of human hair colour is unknown even though greying is obviously associated with ageing. In order to further characterise hair pigmentation in relation with hair growth variables we evaluated 3 scalp sites (top of the head (T): left and right and occipital(O)) in 12 untreated menopausal women (age range: 49-66 years: average 59.63 +/- 5.66) who presented complaining of hair loss and/or diffuse alopecia. Controls were 12 non menopausal sexually mature woman (7 age range 15-21 and 5 age range 38-48) not complaining of hair loss. One hair sample (whenever possible n = 60) was taken one month after clipping from T and O on each person; menopausal women were sampled twice. The following measures were performed with a light microscope: diameter (average min-max., microm), medulla (0% = absent to 100% = fully developed) and linear hair growth rate (mm/day). The hairs were categorised as pigmented (P) or non-pigmented (white, W) as compared with a black and white reference card. A total of 3343 hairs were analysed with 2-factor analysis of variance (ANOVA). A global comparison (all hairs) showed that the average diameter of W hair (67.68 microm) exceeded that of P hair (57.41 microm) (p = 0.0001) and this was maintained on all 3 scalp sites. In addition, the medulla of W hair (23.91%) appeared more developed than the medulla of P hair (12.21%) (p = 0.0001) and was more expressed in W T hairs as compared with W O hairs (p = 0.0325). There was also a significant interaction between site and pigmentation (p = 0.0074). Growth rate of W hairs (0.38 mm/d) was higher than that of P hairs (0.35 mm/d) (p = 0.0001) and there was a significant variation according to scalp sites (p = 0.0001). There was also a significant interaction between site and pigmentation (p = 0.0062) with the following rank order: O W (0.40 mm/d), T W (0.37 mm/d), O P (0.37 mm/d) and T P (0.34 mm/d). Subgroups of W and P of paired thickness in the range of 50 to 80 pm consistently showed a 10% faster growth rate of W. Previous studies have shown that growth rate and diameter declines in age and alopecia i.e. in hair thinning. Our data shows that the reduced growth rate of terminal hairs is in fact limited to the pigmented hairs. The mechanisms by which white hairs are spared these ageing changes are not yet understood. Less pigmented hairs are usually undetected by photo- graphic techniques used for drug trials. The potential role of drug induced modifications of hair pigmentation should be taken into account during the interpretation of efficacy except if contrast-enhancement has been applied. Copyright John Libbey Eurotext 2003.

Evaluation of coastal zone color scanner diffuse attenuation coefficient algorithms for application to coastal waters

NASA Astrophysics Data System (ADS)

Mueller, James L.; Trees, Charles C.; Arnone, Robert A.

1990-09-01

The Coastal Zone Color Scannez (ZCS) and associated atmospheric and in-water algorithms have allowed synoptic analyses of regional and large scale variability of bio-optical properties [phytoplankton pigments and diffuse auenuation coefficient K(490)}. Austin and Petzold (1981) developed a robust in-water K(490) algorithm which related the diffuse attenuation coefficient at one optical depth [1/K(490)] to the ratio of the water-leaving radiances at 443 and 550 nm. Their regression analysis included diffuse attenuation coefficients K(490) up to 0.40 nm, but excluded data from estuarine areas, and other Case II waters, where the optical properties are not predominantly determined by phytoplankton. In these areas, errors are induced in the retrieval of remote sensing K(490) by extremely low water-leaving radiance at 443 nm [Lw(443) as viewed at the sensor may only be 1 or 2 digital counts], and improved cury can be realized using algorithms based on wavelengths where Lw(λ) is larger. Using ocean optical profiles quired by the Visibility Laboratory, algorithms are developed to predict K(490) from ratios of water leaving radiances at 520 and 670, as well as 443 and 550 nm.

Ancestral gene reconstruction and synthesis of ancient rhodopsins in the laboratory.

PubMed

Chang, Belinda S W

2003-08-01

Laboratory synthesis of ancestral proteins offers an intriguing opportunity to study the past directly. The development of Bayesian methods to infer ancestral sequences, combined with advances in models of molecular evolution, and synthetic gene technology make this an increasingly promising approach in evolutionary studies of molecular function. Visual pigments form the first step in the biochemical cascade of events in the retina in all animals known to possess visual capabilities. In vertebrates, the necessity of spanning a dynamic range of light intensities of many orders of magnitude has given rise to two different types of photoreceptors, rods specialized for dim-light conditions, and cones for daylight and color vision. These photoreceptors contain different types of visual pigment genes. Reviewed here are methods of inferring ancestral sequences, chemical synthesis of artificial ancestral genes in the laboratory, and applications to the evolution of vertebrate visual systems and the experimental recreation of an archosaur rod visual pigment. The ancestral archosaurs gave rise to several notable lineages of diapsid reptiles, including the birds and the dinosaurs, and would have existed over 200 MYA. What little is known of their physiology comes from fossil remains, and inference based on the biology of their living descendants. Despite its age, an ancestral archosaur pigment was successfully recreated in the lab, and showed interesting properties of its wavelength sensitivity that may have implications for the visual capabilities of the ancestral archosaurs in dim light.

Pigmented Epithelioid Melanocytoma (PEM)/Animal Type Melanoma (ATM): Quest for an Origin. Report of One Unusual Case Indicating Follicular Origin and Another Arising in an Intradermal Nevus †

PubMed Central

Tarasen, Ashley; Carlson, J. Andrew; Leonard, M. Kathryn; Merlino, Glenn; Kaetzel, David

2017-01-01

Pigmented epithelioid melanocytoma (PEM) is a tumor encompassing epithelioid blue nevus of Carney complex (EBN of CNC) and was previously termed animal-type melanoma. Histologically PEMs are heavily pigmented spindled and epithelioid dermal melanocytic tumors with infiltrative borders, however, their origin remains unclear. Stem cells for the epidermis and hair follicle are located in the bulge area of the hair follicle with the potential to differentiate into multiple lineages. Multiple cutaneous carcinomas, including follicular cutaneous squamous cell carcinoma (FSCC), are thought to arise from stem cells in the follicular bulge. We present two cases of PEM/ATM in a 63 year-old male on the scalp with follicular origin and a 72 year-old female on the upper back arising in an intradermal nevus. Biopsy of both cases revealed a proliferation of heavily pigmented dermal nests of melanocytes with atypia. The Case 1 tumor was in continuation with the outer root sheath of the hair follicle in the bulge region. Case 2 arose in an intradermal melanocytic nevus. Rare mitotic figures, including atypical mitotic figures, were identified in both cases. We present two cases of PEM, with histologic evidence suggesting two origins: one from the follicular bulb and one from an intradermal nevus. PMID:28809777

Unique Temporal Expression of Triplicated Long-Wavelength Opsins in Developing Butterfly Eyes

PubMed Central

Arikawa, Kentaro; Iwanaga, Tomoyuki; Wakakuwa, Motohiro; Kinoshita, Michiyo

2017-01-01

Following gene duplication events, the expression patterns of the resulting gene copies can often diverge both spatially and temporally. Here we report on gene duplicates that are expressed in distinct but overlapping patterns, and which exhibit temporally divergent expression. Butterflies have sophisticated color vision and spectrally complex eyes, typically with three types of heterogeneous ommatidia. The eyes of the butterfly Papilio xuthus express two green- and one red-absorbing visual pigment, which came about via gene duplication events, in addition to one ultraviolet (UV)- and one blue-absorbing visual pigment. We localized mRNAs encoding opsins of these visual pigments in developing eye disks throughout the pupal stage. The mRNAs of the UV and blue opsin are expressed early in pupal development (pd), specifying the type of the ommatidium in which they appear. Red sensitive photoreceptors first express a green opsin mRNA, which is replaced later by the red opsin mRNA. Broadband photoreceptors (that coexpress the green and red opsins) first express the green opsin mRNA, later change to red opsin mRNA and finally re-express the green opsin mRNA in addition to the red mRNA. Such a unique temporal and spatial expression pattern of opsin mRNAs may reflect the evolution of visual pigments and provide clues toward understanding how the spectrally complex eyes of butterflies evolved. PMID:29238294

Laypersons' perceptual discrimination of pigmented skin lesions.

PubMed

Bränström, Richard; Hedblad, Mari-Anne; Krakau, Ingvar; Ullén, Henrik

2002-05-01

Most cutaneous malignant melanomas of the skin are visible and should, at least in theory, be possible to detect with the naked eye. This study was conducted to learn more about laypersons' ability to discriminate between benign pigmented lesions and malignant ones. Four groups of laypersons (n = 120) were asked to evaluate pictures of different types of pigmented skin lesions, before and after they received information about the ABCD (asymmetry, border irregularity, color variegation, and diameter greater than 6 mm) criteria, with respect to the necessity of action. The respondents made adequate assessments of melanomas but overestimated the danger of benign pigmented skin lesions. Information about the ABCD criteria enhanced their ability to make adequate assessments. People seem to make adequate decisions concerning how to act if they have a melanoma. On the other hand, common moles and dysplastic nevi were harder to discriminate. Providing information to the public about the features of melanomas, in accordance with the ABCD criteria, might help laypersons in their perceptual discrimination of skin lesions.

Sulfate-Reducing Bacterium with Unusual Morphology and Pigment Content

PubMed Central

Jones, H. E.

1971-01-01

A dissimilatory sulfate-reducing bacterium was isolated which differed in morphology and pigment content from previously described species. The organism was mesophilic, obligately anaerobic, gram-negative, nonsporulating, long, and slender with one polar flagellum. Whole cells fluoresced red at neutral pH when excited with light at 365 nm owing to the presence of a pink pigment. Desulfoviridin was present. Reduced minus oxidized spectra of whole cells showed peaks in the position of a c-type cytochrome characteristic of Desulfovibrio species and peaks at about 629 and 603 nm. CO difference spectra showed the presence of a CO-binding pigment with a peak at 593 nm. Lactate and pyruvate supported growth in the presence of sulfate but not in its absence. Sulfate, sulfite, and thiosulfate served as electron acceptors for growth. Hydrogenase was present. The deoxyribonucleic acid had a buoyant density of 1.722 g/cm3 and a guanosine plus cystosine molar percentage of total bases calculated by two different methods of 61.2 or 63.2. Images PMID:4929856

S cones: Evolution, retinal distribution, development, and spectral sensitivity.

PubMed

Hunt, David M; Peichl, Leo

2014-03-01

S cones expressing the short wavelength-sensitive type 1 (SWS1) class of visual pigment generally form only a minority type of cone photoreceptor within the vertebrate duplex retina. Hence, their primary role is in color vision, not in high acuity vision. In mammals, S cones may be present as a constant fraction of the cones across the retina, may be restricted to certain regions of the retina or may form a gradient across the retina, and in some species, there is coexpression of SWS1 and the long wavelength-sensitive (LWS) class of pigment in many cones. During retinal development, SWS1 opsin expression generally precedes that of LWS opsin, and evidence from genetic studies indicates that the S cone pathway may be the default pathway for cone development. With the notable exception of the cartilaginous fishes, where S cones appear to be absent, they are present in representative species from all other vertebrate classes. S cone loss is not, however, uncommon; they are absent from most aquatic mammals and from some but not all nocturnal terrestrial species. The peak spectral sensitivity of S cones depends on the spectral characteristics of the pigment present. Evidence from the study of agnathans and teleost fishes indicates that the ancestral vertebrate SWS1 pigment was ultraviolet (UV) sensitive with a peak around 360 nm, but this has shifted into the violet region of the spectrum (>380 nm) on many separate occasions during vertebrate evolution. In all cases, the shift was generated by just one or a few replacements in tuning-relevant residues. Only in the avian lineage has tuning moved in the opposite direction, with the reinvention of UV-sensitive pigments.

Multimodal image analysis of the retina in Hunter syndrome (mucopolysaccharidosis type II): Case report.

PubMed

Salvucci, Isadora Darriba Macedo; Finzi, Simone; Oyamada, Maria Kiyoko; Kim, Chong Ae; Pimentel, Sérgio Luis Gianotti

2018-01-01

We report a case of retinal and posterior ocular findings in a 33-year-old man diagnosed with Hunter syndrome (Mucopolysaccharidosis type II) in a multimodal imaging way. Our patient was complaining of blurred night vision for the past 3 years. He had not received any systemic treatment for Hunter syndrome. Vision acuity was 20/20 in both eyes and corneas were clear. Fundus examination revealed bilateral crowded and hyperemic optic nerve heads (elevated in the ocular ultrasound) and areas of subretinal hypopigmentation. There was hyperautofluorescence at the central fovea and perifovea, and a diffuse bilateral choroidal fluorescence in angiography. Macular SD-OCT showed a thinning of the external retina at the perifovea in both eyes. Visual field testing showed a bilateral ring scotoma. The full field ERG was subnormal, with a negative response in the scotopic phase. Visual Evoked Potencial test and cranial MRI were normal. Our multimodal analysis reported here attempted to contribute to the knowledge of the natural history of GAG deposition in the eye, focusing on the retina and retinal pigment epithelium. Defining this natural history is essential for a proper comparison with Hunter patients receiving systemic treatment, thus determining if it can or cannot improve retinal function in humans with this disorder.

Influence of sodium fluoride (NaF) on the crystallization and spectral properties of L-tyrosine

NASA Astrophysics Data System (ADS)

Thenmozhi, M.; Suguna, K.; Sekar, C.

2011-12-01

L-Tyrosine (C 9H 11NO 3) is an essential amino acid in living organisms. It is also a building unit in protein, takes part in bio-synthesis of hormones, neurotransmitters, pigments and one of the organic chemical constituents of urinary stones. L-Tyrosine has been crystallized in silica gel by double diffusion technique with and without the addition of NaF. The crystals had rosette-like shape. In case of fluoride addition, two types of crystals have formed: rosette like crystallites, at the gel-solution interface and reticulate type crystallites beneath the interface. XRD results confirmed that both the products are of L-tyrosine with identical crystal structures. Crystal structure, morphology, thermal and spectral properties are analyzed using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric and differential thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FTIR) and UV-vis transmittance studies. The TG-DTA results suggest that the thermal stability of L-tyrosine has markedly improved due to fluoride doping. Optical band gap energy of NaF grown L-tyrosine crystallite is estimated as 4.28 eV. Second harmonic generation efficiency test indicates that L-tyrosine crystals can be used for application in nonlinear optical devices.

Transitional analysis of organic thin color filter layers in displays during baking process using multi-speckle diffusing wave spectroscopy

NASA Astrophysics Data System (ADS)

Park, Baek Sung; Hyung, Kyung Hee; Oh, Gwi Jeong; Jung, Hyun Wook

2018-02-01

The color filter (CF) is one of the key components for improving the performance of TV displays such as liquid crystal display (LCD) and white organic light emitting diodes (WOLED). The profile defects like undercut during the fine fabrication processes for CF layers are inevitably generated through the UV exposure and development processes, however, these can be controlled through the baking process. In order to resolve the profile defects of CF layers, in this study, the real-time dynamic changes of CF layers are monitored during the baking process by changing components such as polymeric binder and acrylate. The motion of pigment particles in CF layers during baking is quantitatively interpreted using multi-speckle diffusing wave spectroscopy (MSDWS), in terms of the autocorrelation function and the characteristic time of α-relaxation.

Significant enhancement in the power-conversion efficiency of chlorophyll co-sensitized solar cells by mimicking the principles of natural photosynthetic light-harvesting complexes.

PubMed

Wang, Xiao-Feng; Koyama, Yasushi; Kitao, Osamu; Wada, Yuji; Sasaki, Shin-Ich; Tamiaki, Hitoshi; Zhou, Haoshen

2010-04-15

Dye-sensitized solar cells (DSSCs) are similar to natural photosynthesis in the initial processes involving in light-harvesting and charge separation. In order to mimic those natural photosynthetic systems mainly containing multiple pigments, six different chlorophyllous sensitizers have been isolated from natural photosynthetic organism or synthesized based on natural photosynthetic precursors, and used for fabricating DSSCs. These dye sensitizers can be placed into three classes, i.e., a-type, b-type, or c-type, based on the structural similarity to their analogs of the natural photosynthesis pigments chlorophylls a, b, and c. We succeeded in demonstrating homogeneous co-sensitization among these analogues when these were present together on mesoporous TiO2 films, and we measured the photovoltaic performance of the resulting chlorophyll-sensitized solar cells. Significantly enhanced power-conversion efficiencies (eta) were achieved with DSSCs based on co-sensitization of a chlorophyll a derivative with a chlorophyll b or c derivative. A highest power-conversion efficiency of up to 5.4% has been obtained. These results suggest that it is possible to apply multiple pigments and the energy transfer mechanism from natural photosynthetic systems in fabricating high-efficiency DSSCs. 2010 Elsevier B.V. All rights reserved.

Nondestructive analysis of senescence in mesophyll cells by spectral resolution of protein synthesis-dependent pigment metabolism.

PubMed

Gay, Alan; Thomas, Howard; Roca, María; James, Caron; Taylor, Janet; Rowland, Jem; Ougham, Helen

2008-01-01

* Over 6 d of dark-induced senescence, leaf segments of wild-type Lolium temulentum lost > 96% chlorophyll a + b; leaves from plants containing a staygreen mutation introgressed from Festuca pratensis, which has a lesion in the senescence-associated fragmentation of pigment-proteolipid complexes, retained over 43% of total chlorophyll over the same period. * Mutant segments preferentially retained thylakoid membrane proteins (exemplified by LHCP II) but lost other cellular proteins at the same rate as wild-type tissue. The protein synthesis inhibitor D-MDMP inhibited chlorophyll degradation and partially prevented protein loss in both genotypes, but tissues treated with the ineffective L-stereoisomer were indistinguishable from water controls. * Principal-components analysis of leaf reflectance spectra distinguished between genotypes, time points and D-MDMP treatments, showing the disruption of pigment metabolism during senescence brought about by the staygreen mutation, by inhibition of protein synthesis and by combinations of the two factors. * The build-up of oxidized, dephytylated and phaeo-derivatives of chl a during senescence of staygreen tissue was prevented by D-MDMP and associated with characteristic difference spectra when senescent mutant tissue was compared with wild-type or inhibitor-treated samples. The suitability of senescence as a subject for systems biology approaches is discussed.

Thctf1 transcription factor of Trichoderma harzianum is involved in 6-pentyl-2H-pyran-2-one production and antifungal activity.

PubMed

Rubio, M Belén; Hermosa, Rosa; Reino, José Luis; Collado, Isidro G; Monte, Enrique

2009-01-01

We describe the cloning and characterization of the Trichoderma harzianum Thctf1 gene, which shows high sequence identity with a transcription factor gene of Fusarium solani f. sp. pisi. In T. harzianum, disruption of the Thctf1 gene by homologous recombination gave rise to transformants that in plate experiments did not show the yellow pigmentation observed in the wild-type strain. In several Trichoderma spp. a yellow pigmentation and a coconut aroma have been related to the production of 6-pentyl-2H-pyran-2-one (6PP) compounds. Prompted by this, we explored whether the loss of pigmentation in the Thctf1 null mutants of T. harzianum might be related to the synthesis of 6PP. Chromatographic and spectroscopic analyses revealed that the disruptants did not produce two secondary metabolites, derived from 6PP and not previously described in the Trichoderma genus, that are present in wild-type culture filtrates. Since 6PP is a recognized antifungal compound, this ability was analyzed in both the disruptants and wild-type, observing that the Thctf1 null mutants of T. harzianum had reduced antimicrobial capacity. Our results point to the significant role of THCTF1 in the production of secondary metabolites and in the antifungal activity of T. harzianum.

Biological and remote sensing perspectives of pigmentation in coral reef organisms.

PubMed

Hedley, John D; Mumby, Peter J

2002-01-01

Coral reef communities face unprecedented pressures on local, regional and global scales as a consequence of climate change and anthropogenic disturbance. Optical remote sensing, from satellites or aircraft, is possibly the only means of measuring the effects of such stresses at appropriately large spatial scales (many thousands of square kilometres). To map key variables such as coral community structure, percentages of living coral or percentages of dead coral, a remote sensing instrument must be able to distinguish the reflectance spectra (i.e. "spectral signature", reflected light as a function of wavelength) of each category. For biotic classes, reflectance is a complex function of pigmentation, structure and morphology. Studies of coral "colour" fall into two disparate but potentially complementary types. Firstly, biological studies tend to investigate the structure and significance of pigmentation in reef organisms. These studies often lack details that would be useful from a remote sensing perspective such as intraspecific variation in pigment concentration or the contribution of fluorescence to reflectance. Secondly, remote sensing studies take empirical measurements of spectra and seek wavelengths that discriminate benthic categories. Benthic categories used in remote sensing sometimes consist of species groupings that are biologically or spectrally inappropriate (e.g. merging of algal phyla with distinct pigments). Here, we attempt to bridge the gap between biological and remote sensing perspectives of pigmentation in reef taxa. The aim is to assess the extent to which spectral discrimination can be given a biological foundation, to reduce the ad hoc nature of discriminatory criteria, and to understand the fundamental (biological) limitations in the spectral separability of biotic classes. Sources of pigmentation in reef biota are reviewed together with remote sensing studies where spectral discrimination has been effectively demonstrated between benthic categories. The basis of reflectance is considered as the sum of pigmented components, such as zooxanthellae, host tissues and skeletons of corals. Problems in the empirical in situ measurement of reflectance are identified, such as the differing types of reflectance which can be measured, the interaction of the light field with morphology, and depth-dependent variability of measured reflectance due to fluorescence. The latter is estimated in some cases to introduce an error of up to 20% when depth differs by 8 m. Spectral features useful in discriminating reef benthos are identified and related to pigmentation. The slope in the reflectance spectra between 650 and 690 nm is dependent on chlorophyll-a concentration and can be used to discriminate bare sand with no algal component from chlorophyll-a containing benthos (algae, corals). The slope in reflectance at various locations between 500 and 560 nm can be useful in discriminating bleached and unbleached corals, possibly due to reduced peridinin concentration. Rhodophyta may be discernible by the presence of a dip in reflectance at 570 nm, due to a phycoerythrin absorption peak. However, the utility of some discriminatory criteria in deeper waters is mitigated by the relatively poor transmission of light through water at longer wavelengths (especially > 600 nm). Contrary to suggested categorizations of fluorescent pigments in coral host tissues, it is shown that these pigments form an almost continuous distribution with respect to their excitation and emission peaks. Remote sensing by induced fluorescence is a promising approach, but further details about the variation and distribution of these pigments are required. It is hoped that this review will promote cross-disciplinary collaboration between pigment biologists and the reef remote sensing community. Where possible, the discriminative criteria adopted in remote sensing should be related to biological phenomena, thus lending an intuitive, process-orientated basis for interpreting spectral data. Similarly, remote sensing may provide a novel scaling perspective to biological studies of pigmentation in reef organisms.

Transplanting Retinal Cells using Bucky Paper for Support

NASA Technical Reports Server (NTRS)

Loftus, David J.; Cinke, Martin; Meyyappan, Meyya; Fishman, Harvey; Leng, Ted; Huie, Philip; Bilbao, Kalayaan

2004-01-01

A novel treatment for retinal degenerative disorders involving transplantation of cells into the eye is currently under development at NASA Ames Research Center and Stanford University School of Medicine. The technique uses bucky paper as a support material for retinal pigment epithelial (RPE) cells, iris pigment epithelial (IPE) cells, and/or stem cells. This technology is envisioned as a treatment for age-related macular degeneration, which is the leading cause of blindness in persons over age 65 in Western nations. Additionally, patients with other retinal degenerative disorders, such as retinitis pigmentosa, may be treated by this strategy. Bucky paper is a mesh of carbon nanotubes (CNTs), as shown in Figure 1, that can be made from any of the commercial sources of CNTs. Bucky paper is biocompatible and capable of supporting the growth of biological cells. Because bucky paper is highly porous, nutrients, oxygen, carbon dioxide, and waste can readily diffuse through it. The thickness, density, and porosity of bucky paper can be tailored in manufacturing. For transplantation of cells into the retina, bucky paper serves simultaneously as a substrate for cell growth and as a barrier for new blood vessel formation, which can be a problem in the exudative type of macular degeneration. Bucky paper is easily handled during surgical implantation into the eye. Through appropriate choice of manufacturing processes, bucky paper can be made relatively rigid yet able to conform to the retina when the bucky paper is implanted. Bucky paper offers a distinct advantage over other materials that have been investigated for retinal cell transplantation - lens capsule and Descemet's membrane - which are difficult to handle during surgery because they are flimsy and do not stay flat.

Chromoplast-specific carotenoid-associated protein appears to be important for enhanced accumulation of carotenoids in hp1 tomato fruits.

PubMed

Kilambi, Himabindu Vasuki; Kumar, Rakesh; Sharma, Rameshwar; Sreelakshmi, Yellamaraju

2013-04-01

Tomato (Solanum lycopersicum) high-pigment mutants with lesions in diverse loci such as DNA Damage-Binding Protein1 (high pigment1 [hp1]), Deetiolated1 (hp2), Zeaxanthin Epoxidase (hp3), and Intense pigment (Ip; gene product unknown) exhibit increased accumulation of fruit carotenoids coupled with an increase in chloroplast number and size. However, little is known about the underlying mechanisms exaggerating the carotenoid accumulation and the chloroplast number in these mutants. A comparison of proteome profiles from the outer pericarp of hp1 mutant and wild-type (cv Ailsa Craig) fruits at different developmental stages revealed at least 72 differentially expressed proteins during ripening. Hierarchical clustering grouped these proteins into three clusters. We found an increased abundance of chromoplast-specific carotenoid-associated protein (CHRC) in hp1 fruits at red-ripe stage that is also reflected in its transcript level. Western blotting using CHRC polyclonal antibody from bell pepper (Capsicum annuum) revealed a 2-fold increase in the abundance of CHRC protein in the red-ripe stage of hp1 fruits compared with the wild type. CHRC levels in hp2 were found to be similar to that of hp1, whereas hp3 and Ip showed intermediate levels to those in hp1, hp2, and wild-type fruits. Both CHRC and carotenoids were present in the isolated plastoglobules. Overall, our results suggest that loss of function of DDB1, DET1, Zeaxanthin Epoxidase, and Ip up-regulates CHRC levels. Increase in CHRC levels may contribute to the enhanced carotenoid content in these high-pigment fruits by assisting in the sequestration and stabilization of carotenoids.

Chromoplast-Specific Carotenoid-Associated Protein Appears to Be Important for Enhanced Accumulation of Carotenoids in hp1 Tomato Fruits1[C][W][OA

PubMed Central

Kilambi, Himabindu Vasuki; Kumar, Rakesh; Sharma, Rameshwar; Sreelakshmi, Yellamaraju

2013-01-01

Tomato (Solanum lycopersicum) high-pigment mutants with lesions in diverse loci such as DNA Damage-Binding Protein1 (high pigment1 [hp1]), Deetiolated1 (hp2), Zeaxanthin Epoxidase (hp3), and Intense pigment (Ip; gene product unknown) exhibit increased accumulation of fruit carotenoids coupled with an increase in chloroplast number and size. However, little is known about the underlying mechanisms exaggerating the carotenoid accumulation and the chloroplast number in these mutants. A comparison of proteome profiles from the outer pericarp of hp1 mutant and wild-type (cv Ailsa Craig) fruits at different developmental stages revealed at least 72 differentially expressed proteins during ripening. Hierarchical clustering grouped these proteins into three clusters. We found an increased abundance of chromoplast-specific carotenoid-associated protein (CHRC) in hp1 fruits at red-ripe stage that is also reflected in its transcript level. Western blotting using CHRC polyclonal antibody from bell pepper (Capsicum annuum) revealed a 2-fold increase in the abundance of CHRC protein in the red-ripe stage of hp1 fruits compared with the wild type. CHRC levels in hp2 were found to be similar to that of hp1, whereas hp3 and Ip showed intermediate levels to those in hp1, hp2, and wild-type fruits. Both CHRC and carotenoids were present in the isolated plastoglobules. Overall, our results suggest that loss of function of DDB1, DET1, Zeaxanthin Epoxidase, and Ip up-regulates CHRC levels. Increase in CHRC levels may contribute to the enhanced carotenoid content in these high-pigment fruits by assisting in the sequestration and stabilization of carotenoids. PMID:23400702

Diagnosis and staging of female genital tract melanocytic lesions using pump-probe microscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Robles, Francisco E.; Selim, Maria A.; Warren, Warren S.

2016-02-01

Melanoma of the vulva is the second most common type of malignancy afflicting that organ. This disease caries poor prognosis, and shows tendencies to recur locally and develop distant metastases through hematogenous dissemination. Further, there exists significant clinical overlap between early-stage melanomas and melanotic macules, benign lesions that are believed to develop in about 10% of the general female population. In this work we apply a novel nonlinear optical method, pump-probe microscopy, to quantitatively analyze female genitalia tract melanocytic lesions. Pump-probe microscopy provides chemical information of endogenous pigments by probing their electronic excited state dynamics, with subcellular resolution. Using unstained biopsy sections from 31 patients, we find significant differences between melanin type and structure in tissue regions with invasive melanoma, melanoma in-situ and non-malignant melanocytic proliferations (e.g., nevi, melanocytic macules). The molecular images of non-malignant lesion have a well-organized structure, with relatively homogenous pigment chemistry, most often consistent with that of eumelanin with large aggregate size or void of metals, such as iron. On the other hand, pigment type and structure observed in melanomas in-situ and invasive melanomas is typically much more heterogeneous, with larger contributions from pheomelanin, melanins with larger metal content, and/or melanins with smaller aggregate size. Of most significance, clear differences can be observed between melanocytic macules and vulvar melanoma in-situ, which, as discussed above, can be difficult to clinically distinguish. This initial study demonstrates pump-probe microscopy's potential as an adjuvant diagnostic tool by revealing systematic chemical and morphological differences in melanin pigmentation among invasive melanoma, melanoma in-situ and non-malignant melanocytic lesions.

Identification of Novel G Protein–Coupled Receptor 143 Ligands as Pharmacologic Tools for Investigating X-Linked Ocular Albinism

PubMed Central

De Filippo, Elisabetta; Manga, Prashiela; Schiedel, Anke C.

2017-01-01

Purpose GPR143 regulates melanosome biogenesis and organelle size in pigment cells. The mechanisms underlying receptor function remain unclear. G protein–coupled receptors (GPCRs) are excellent pharmacologic targets; thus, we developed and applied a screening approach to identify potential GPR143 ligands and chemical modulators. Methods GPR143 interacts with β-arrestin; we therefore established a β-arrestin recruitment assay to screen for compounds that modulate activity. Because GPR143 is localized intracellularly, screening with the wild-type receptor would be restricted to agents absorbed by the cell. For the screen we used a mutant receptor, which shows similar basal activity as the wild type but traffics to the plasma membrane. We tested two compound libraries and investigated validated hits for their effects on melanocyte pigmentation. Results GPR143, which showed high constitutive activity in the β-arrestin assay, was inhibited by several compounds. The three validated inhibitors (pimozide, niclosamide, and ethacridine lactate) were assessed for impact on melanocytes. Pigmentation and expression of tyrosinase, a key melanogenic enzyme, were reduced by all compounds. Because GPR143 appears to be constitutively active, these compounds may turn off its activity. Conclusions X-linked ocular albinism type I, characterized by developmental eye defects, results from GPR143 mutations. Identifying pharmacologic agents that modulate GPR143 activity will contribute significantly to our understanding of its function and provide novel tools with which to study GPCRs in melanocytes and retinal pigment epithelium. Pimozide, one of three GPR143 inhibitors identified in this study, maybe be a good lead structure for development of more potent compounds and provide a platform for design of novel therapeutic agents. PMID:28632878

1H NMR quantitative determination of photosynthetic pigments from green beans (Phaseolus vulgaris L.).

PubMed

Valverde, Juan; This, Hervé

2008-01-23

Using 1H nuclear magnetic resonance spectroscopy (1D and 2D), the two types of photosynthetic pigments (chlorophylls, their derivatives, and carotenoids) of "green beans" (immature pods of Phaseolus vulgaris L.) were analyzed. Compared to other analytical methods (light spectroscopy or chromatography), 1H NMR spectroscopy is a fast analytical way that provides more information on chlorophyll derivatives (allomers and epimers) than ultraviolet-visible spectroscopy. Moreover, it gives a large amount of data without prior chromatographic separation.

Complications of Medium Depth and Deep Chemical Peels

PubMed Central

Nikalji, Nanma; Godse, Kiran; Sakhiya, Jagdish; Patil, Sharmila; Nadkarni, Nitin

2012-01-01

Superficial and medium depth peels are dynamic tools when used as part of office procedures for treatment of acne, pigmentation disorders, and photo-aging. Results and complications are generally related to the depth of wounding, with deeper peels providing more marked results and higher incidence of complications. Complications are also more likely with darker skin types, certain peeling agents, and sun exposure. They can range from minor irritations, uneven pigmentation to permanent scarring. In very rare cases, complications can be life-threatening. PMID:23378707

Color-Changing Sensors for Detecting the Presence of Hypergolic Fuels

NASA Technical Reports Server (NTRS)

Roberson, Luke; Captain, Janine; Santiago-Maldonado, Edgardo; Starr, Stanley; DeVor, Robert

2013-01-01

Hypergolic fuel sensors were designed to incorporate novel chemochromic pigments into substrates for use in various methods of leak detection. There are several embodiments to this invention that would provide specific visual indication of hypergols used during and after transfer. The ability to incorporate these pigments into various polymer matrices provides a unique opportunity to manufacture nearly any type of sensor shape that is required. The vibrant color change from yellow to black instantaneously shows the worker the presence of hypergols in the area.

A submesoscale coherent vortex in the Ligurian Sea: From dynamical barriers to biological implications

NASA Astrophysics Data System (ADS)

Bosse, Anthony; Testor, Pierre; Mayot, Nicolas; Prieur, Louis; D'Ortenzio, Fabrizio; Mortier, Laurent; Le Goff, Hervé; Gourcuff, Claire; Coppola, Laurent; Lavigne, Héloïse; Raimbault, Patrick

2017-08-01

In June 2013, a glider equipped with oxygen and fluorescence sensors has been used to extensively sample an anticyclonic Submesoscale Coherent Vortex (SCV) in the Ligurian Sea (NW Mediterranean Sea). Those measurements are complemented by full-depth CTD casts (T, S, and oxygen) and water samples documenting nutrients and phytoplankton pigments within the SCV and outside. The SCV has a very homogeneous core of oxygenated waters between 300 and 1200 m formed 4.5 months earlier during the winter deep convection event. It has a strong dynamical signature with peak velocities at 700 m depth of 13.9 cm s-1 in cyclogeostrophic balance. The eddy has a small radius of 6.2 km corresponding to high Rossby number of -0.45. The vorticity at the eddy center reaches -0.8f. Cross-stream isopycnic diffusion of tracers between the eddy core and the surroundings is found to be very limited due to dynamical barriers set by the SCV associated with a diffusivity coefficient of about 0.2 m2 s-1. The deep core is nutrients-depleted with concentrations of nitrate, phosphate, and silicate, 13-18% lower than the rich surrounding waters. However, the nutriclines are shifted of about 20-50 m toward the surface thus increasing the nutrients availability for phytoplankton. Chlorophyll-a concentrations at the deep chlorophyll maximum are subsequently about twice bigger as compared to outside. Pigments further reveal the predominance of nanophytoplankton inside the eddy and an enhancement of the primary productivity. This study demonstrates the important impact of postconvective SCVs on nutrients distribution and phytoplankton community, as well as on the subsequent primary production and carbon sequestration.