Spelling suggestions: "subject:"astaxanthin""
1 |
Mammalian Carotenoid MetabolismPalczewski, Grzegorz 01 September 2016 (has links)
No description available.
|
2 |
Macular Pigment and Lens Optical Density Measurements-Evaluating a Flicker Machine with Novel FeaturesMukherjee, Anirbaan 02 July 2015 (has links)
Age related macular degeneration (AMD) is one of the leading causes of blindness amongst the elderly. Macular pigment (MP) in the retina has been established to protect individuals against AMD. Improving levels of MP by diet or supplements is the constant quest of clinical practitioners and researchers, thus necessitating development of instruments capable of repeatable and reliable MP measurement. Cataract, a consequence of the rising opacity levels of the lens with age is one of the other major causes of blindness in the world. Mapcatsf, a LED-based microprocessor-controlled heterochromatic flicker photometer (HFP) using photopic vision is capable of measuring the levels of MP and the opacity of the lens in terms of optical density.
Test-retest measurements conducted on 83 subjects were analyzed for repeatability in macular pigment optical density (MPOD) measurements. Reliability of the lens optical density (LOD) measurements were tested and compared with those obtained at absolute scotopic thresholds for 25 individuals. A supplement study with 32 individuals both in the young (50) age groups for 6 months further established Mapcatsf’s capacity to monitor changing levels of MP in individuals. As an overall outcome, high levels of repeatability and reliability were obtained in MPOD and LOD measurements establishing Mapcatsf as an instrument for use in clinical settings in the future.
|
3 |
Macular pigment optical density measurements by one-wavelength reflection photometry – Influence of cataract surgery on the measurement resultsKomar, Bogdana 02 July 2015 (has links) (PDF)
Purpose:
The main objective of the present study was the investigation of possible influence of lens opacification on macular pigment optical density (MPOD) measurements.
Methods:
86 eyes of 64 patients (mean age 73.4(±8.3)years) were included in the study. MPOD was prospectively measured using one-wavelength reflection method (Visucam500, Carl Zeiss Meditec AG) before and after cataract extraction with implantation of a blue-light filtering intraocular lens (AlconSN60WF). The median of the maximum optical density (MaxOD) and the median of the mean optical density (MeanOD) measurements of macular pigment across the subject group were evaluated.
Results:
Statistically significant differences were noticed between pre-operative and post-operative measurements, the absolute values were generally lower after cataract extraction. The following median(lower/upper quartile) differences across the group were determined: MaxOD -33.8%(-46.2%/-19.1%), MeanOD -44.0%(-54.6%/-26.6%). Larger changes were observed in elderly patients (<70years of age: (n=25eyes) MaxOD -13.4%(-20.5%/3.6%), MeanOD -23.6%(-30.5%/-15.3%) versus patients ≥70years: (n=61eyes) MaxOD -40.5%(-53.2%/-30.1%), MeanOD -47.2%(-57.8%/-40.1%)) and in patients with progressed stage of cataract. MaxOD for lens opacification grade 1:(n=9eyes) -27.4%(-42.1%/-19.6%), 2:(n=26eyes) -35.0%(-44.2%/-25.3%), 3:(n=21eyes) -34.4%(-45.4%/-11.4%), 4:(n=25eyes) -32.6%(-53.2%/-6.4%) and 5:(n=5eyes) -53.5%(-61.7%/-38.7%) and MeanOD for cataract stage 1:(n=9eyes) -42.6%(-46.0%/-26.0%), 2:(n=26eyes) -44.1%(-51.8%/26.2%), 3:(n=21eyes) -45.7%(-54.7%/-24.7%), 4:(n=25eyes) -39.5%(-59.4%/-26.1%), 5:(n=5eyes) -57.0%(-66.1%/-51.4%).
Conclusions:
As established by comparison of pre- to post-operative measurements, cataract presented a strong effect on MPOD measured by one-wavelength reflection method. Particular care should therefore be taken when evaluating MPOD using this method in elderly patients with progressed stage of cataract. Future optimization of correcting parameters of scattered light and consideration of cataract influence may allow more precise evaluation of MPOD.
|
4 |
Macular pigment optical density measurements by one-wavelength reflection photometry – Influence of cataract surgery on the measurement resultsKomar, Bogdana 18 June 2015 (has links)
Purpose:
The main objective of the present study was the investigation of possible influence of lens opacification on macular pigment optical density (MPOD) measurements.
Methods:
86 eyes of 64 patients (mean age 73.4(±8.3)years) were included in the study. MPOD was prospectively measured using one-wavelength reflection method (Visucam500, Carl Zeiss Meditec AG) before and after cataract extraction with implantation of a blue-light filtering intraocular lens (AlconSN60WF). The median of the maximum optical density (MaxOD) and the median of the mean optical density (MeanOD) measurements of macular pigment across the subject group were evaluated.
Results:
Statistically significant differences were noticed between pre-operative and post-operative measurements, the absolute values were generally lower after cataract extraction. The following median(lower/upper quartile) differences across the group were determined: MaxOD -33.8%(-46.2%/-19.1%), MeanOD -44.0%(-54.6%/-26.6%). Larger changes were observed in elderly patients (<70years of age: (n=25eyes) MaxOD -13.4%(-20.5%/3.6%), MeanOD -23.6%(-30.5%/-15.3%) versus patients ≥70years: (n=61eyes) MaxOD -40.5%(-53.2%/-30.1%), MeanOD -47.2%(-57.8%/-40.1%)) and in patients with progressed stage of cataract. MaxOD for lens opacification grade 1:(n=9eyes) -27.4%(-42.1%/-19.6%), 2:(n=26eyes) -35.0%(-44.2%/-25.3%), 3:(n=21eyes) -34.4%(-45.4%/-11.4%), 4:(n=25eyes) -32.6%(-53.2%/-6.4%) and 5:(n=5eyes) -53.5%(-61.7%/-38.7%) and MeanOD for cataract stage 1:(n=9eyes) -42.6%(-46.0%/-26.0%), 2:(n=26eyes) -44.1%(-51.8%/26.2%), 3:(n=21eyes) -45.7%(-54.7%/-24.7%), 4:(n=25eyes) -39.5%(-59.4%/-26.1%), 5:(n=5eyes) -57.0%(-66.1%/-51.4%).
Conclusions:
As established by comparison of pre- to post-operative measurements, cataract presented a strong effect on MPOD measured by one-wavelength reflection method. Particular care should therefore be taken when evaluating MPOD using this method in elderly patients with progressed stage of cataract. Future optimization of correcting parameters of scattered light and consideration of cataract influence may allow more precise evaluation of MPOD.
|
5 |
Avaliação de milho e derivados de milho como fontes de luteina e zeaxantina / Evaluation of corn and corn products as lutein and zeaxanthin sourcesOliveira, Giovanna Pisanelli Rodrigues de 14 March 2006 (has links)
Orientador: Delia Rodriguez-Amaya / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-05T22:37:14Z (GMT). No. of bitstreams: 1
Oliveira_GiovannaPisanelliRodriguesde_M.pdf: 717154 bytes, checksum: 6bd8167ae6c34a616ee50857b97e1f31 (MD5)
Previous issue date: 2006 / Resumo: A determinação de luteína e zeaxantina, carotenóides relacionados à proteção contra a catarata e a degeneração macular associada a idade, pode ajudar na proteção da população da terceira idade contra estas doenças. O milho é uma das únicas fontes de ambos carotenóides. Dentre os produtos analisados (milho in natura, milho cozido, milho enlatado, polentas frita e cozida, curau e pamonha) por cromatografia líquida de alta eficiência, o milho enlatado apresentou, em geral, os maiores teores de carotenóides (0,56 a 4,12 mg/g de luteína, 7,10 a 22,90 mg/g de zeaxantina, 0,60 a 4,90 mg/g de b-criptoxantina e 0,13 a 3,45 mg/g de b-caroteno). O milho in natura e o milho cozido, diferentemente dos outros produtos analisados, não apresentaram como carotenóide majoritário a zeaxantina e sim a luteína (3,37 a 5,29 _g/g e 2,79 a 5,47 para milho in natura e cozido, respectivamente). Os teores de carotenóides das polentas frita e cozida, curau e pamonha foram muito baixos. As farinhas e cereais matinais a base de milho, também analisados, apresentaram, em geral, a zeaxantina como carotenóide majoritário, seguido pela luteína. Os pró-vitamínicos, b-caroteno e b-criptoxantina apareceram em pequenas concentrações. Os teores de luteína e zeaxantina (mg/g) variaram, respectivamente, de 1,52 a 6,54 e 2,93 a 15,01 para farinhas derivadas de milho e 1,83 a 4,88 e 7,54 a 16,24 para cereais matinais. Houve variação marcante entre marcas do mesmo produto, mas pequenas variações entre lotes da mesma marca / Abstract: The determination of luteína and zeaxantina, carotenóides related to the protection against the cataract and the degeneration to stain associated the age, can help in the protection of the population of the third age against these illnesses. The maize is one of the only sources of both carotenóides. Amongst the products analyzed (maize in natura, cooked maize, tinned maize, polentas fries and cozida, curau and pamonha) for liquid chromatography of high efficiency, the tinned maize presented, in general, the biggest texts of carotenóides (0,56 the 4,12 mg/g of luteína, 7,10 the 22,90 mg/g of zeaxantina, 0,60 the 4,90 mg/g of the 3,45 b-criptoxantina and 0,13 mg/g of b-carotene). The maize in natura and the cooked maize, differently of the other analyzed products, had not presented as carotenóide majority the zeaxantina and yes the luteína (3,37 the 5,29 _ g/g and 2,79 the 5,47 for maize in natura and stew, respectively). The texts of carotenóides of the polentas fry and cozida, curau and pamonha had been very low. The matinal flours and cereals the maize base, also analyzed, had presented, in general, the majority zeaxantina as carotenóide, followed for the luteína. The pro-vitaminic ones, b-carotene and b-criptoxantina had appeared in small concentrations. The texts of luteína and zeaxantina (mg/g) had varied, respectively, of 1,52 6,54 and 2,93 the 15.01 for flours derived from maize and 1,83 4,88 and 7,54 the 16,24 for matinal cereals. It had marcante variation between marks of the same product, but small variations between lots of the same mark / Mestrado / Mestre em Ciência de Alimentos
|
6 |
Studies on sustainable technologies for utilization and preservation of marine resources: ethanol production from macroalgae and protection of reef-building corals from environmental stresses / 大型藻類を用いたエタノール生産と造礁サンゴの環境ストレスからの保護を目的とした海洋資源の利用・保全技術に関する研究Motone, Keisuke 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22513号 / 農博第2417号 / 新制||農||1078(附属図書館) / 学位論文||R2||N5293(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 植田 充美, 教授 渡邊 隆司, 教授 小川 順 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
|
7 |
Mechanisms of Xanthophyll Uptake in Retinal Pigment Epithelial CellsThomas, Sara E. January 2016 (has links)
No description available.
|
8 |
Lutein and zeaxanthin: use of in vitro models to examine digestive stability, absorption, and photoprotective activity in human lens epithelial cellsChitchumroonchokchai, Chureeporn 19 October 2004 (has links)
No description available.
|
9 |
Extraction, identification et caractérisation pharmacologique de pigments de Porphyridium purpureum sur cellules de mélanome humain / Extraction, identification and pharmalogical caracterisation of Porphyridium purpureum pigments in human melanoma cellsJuin, Camille 19 October 2015 (has links)
20 000 Européens meurent chaque année du mélanome et le taux de mortalité ne cesse de s’accroître. Les cellules de mélanome se caractérisent principalement par la mutation des kinases RAS, B-RAF et RHO-B. Ces mutations leur confèrent une résistance aux agents chimiothérapeutiques. Un grand nombre de travaux a établi que les pigments d’algues présentent un intérêt majeur pour prévenir, diagnostiquer et traiter les cancers. L’objectif de ce travail de thèse est de réaliser un travail de recherche intégré pour identifier des pigments de microalgues pouvant présenter un intérêt pour le diagnostic ou le traitement des mélanomes et de caractériser leur activité pharmacologique. Notre choix s’est porté sur Porphyridium purpureum, une espèce qui contient des phycobiliprotéines, des caroténoïdes dont la zéaxanthine. Nous avons développé des procédés innovants pour l’extraction et l’identification des pigments de microalgues. Ce travail a permis de réaliser la première extraction de phycobiliprotéines assistée sous champ microondes ainsi que l’identification des pigments de microalgue par UPLC-MSE au sein d’un mélange complexe. De plus, nous avons montré l’activité pro-apoptotique de la zéaxanthine et la caractérisation de son mode d’action sur les cellules de mélanome humain A2058. L’IC50 obtenue pour ce pigment est inférieure à celle du cisplatine (agent chimiothérapeutique). Ces résultats montrent le fort potentiel de ce pigment pour le traitement du mélanome résistant à la chimiothérapie. / 20 000 Europeans die from melanoma each year and this number is constantly increasing. Melanoma cells are mainly characterized by the mutation of the RAS, B-RAF and RHO-B kinases. Because of these mutations, the cells are resistant to chemotherapeutic agents. A lot of studies have established that the algae pigments are of major interest to prevent diagnose and treat cancers. The objective of this thesis is to undertake an integrated research work to identify microalgae pigments that may be relevant for the diagnosis or treatment of melanomas and to characterize their pharmacological activity. We selected Porphyridium purpureum, a species which contains phycobiliproteins, carotenoids including zeaxanthin. We developed innovative processes for the extraction and identification of microalgae pigments. This work resulted in the first extraction of phycobiliproteins under microwave-assisted irradiations, and the identification of microalgae pigments by UPLC-MSE within a complex mixture. Moreover, we demonstrated the proapoptotic activity of zeaxanthin and the characterization of its mode of action on A2058 human melanoma cells. The CI50 obtained for this pigment is lower than that of cisplatin (chemotherapeutic drug). These results show the great potential of this pigment for the treatment of melanoma which are resistant to chemotherapy.
|
10 |
Biochemistry and genetics of carotenoid composition in potato tubersOthman, Rashidi January 2009 (has links)
Potato cultivars exhibit a wide variation in skin and flesh colour due to the presence of pigments. This study established that potato cultivars differ greatly with respect to types and concentrations of carotenoids in tubers. A total of 46 cultivars were evaluated for quantitative and qualitative carotenoid composition in different growing seasons, locations, storage conditions and disease symptoms. Factors controlling carotenoid accumulation were also tested by developing an in vitro minituber system as a new high-throughput model system for carotenogenesis in potato tubers. Tuber flesh colour was found to correlate with total carotenoid content in potato cultivars grown in both New Zealand and Netherlands. The main carotenoids identified in 32 potato cultivars in New Zealand were lutein, neoxanthin, violaxanthin and β-carotene. The ratio of these carotenoids varies between cultivars. Neoxanthin was detected in only 13 cultivars (10.59 to 69.21µg/g DW); violaxanthin was found only in 1 cultivar (32.76 µg/g DW). Whereas lutein and β-carotene were found in most of the cultivars but the concentration varied from (0.00 to 160.63 µg/g DW) and (0.00 to 13.62 µg/g DW) respectively. The main carotenoids identified in 12 cultivars grown in the Netherlands were neoxanthin, violaxanthin and lutein, whereas zeaxanthin was not found in any of the cultivars analysed. Marked differences were observed between the same potato cultivars grown in New Zealand and the Netherlands. Therefore cultivars were analysed over a second growing season to assess stability in carotenoids composition. The carotenoid profiles of the potato tubers grown for two different seasons showed highly significant differences between the cultivars, the seasons, the carotenoid pigments, and all combinations of interactions, indicating the complex nature of factors influencing carotenoid composition. Reflectance colorimeter measurement of yellow hue component in this study confirmed that the higher the total carotenoid content, the greater the yellow intensity colour. Eight cultivars were grown at three locations in New Zealand and Agria and Desiree were grown at eight locations in the Netherlands to further investigate the stability of carotenoid composition. Highly significant differences were observed between the cultivars, the locations, the carotenoid pigments, and all combinations of interactions, which emphasises that changes in carotenoid composition are complex and the responses are not consistent across cultivars. Reflectance colorimeter measurement of yellow hue component confirmed the relationship between the yellow colour intensity of tuber flesh, as well as confirming the interaction between colour and locations. Disease and post harvest storage conditions markedly influenced the levels of total carotenoid, neoxanthin, violaxanthin, zeaxanthin, lutein and β-carotene in potatoes. The magnitude of these effects depends on the cultivar, time of storage, and the intensity of powdery scab symptoms. Results showed that long term storage resulted in the accumulation of neoxanthin, violaxanthin and zeaxanthin with a concomitant decreased of lutein, β-carotene and total carotenoid content. Genotypes infected with disease (lower and higher scab score) resulted in accumulation of violaxanthin, β-carotene and total carotenoid with a concomitant decreased in neoxanthin and lutein. A high-throughput model system for investigating carotenoid biogenesis in potato tubers was developed. This involved in vitro potato minitubers and was validated by assessing the effects of environmental variables, such as drought stress, light intensity and nutrient availability on carotenoid accumulation. Light influenced the presence of zeaxanthin, whereas water stress and nutrient strength influenced the accumulation of neoxanthin and violaxanthin. Although these factors had an effect on the carotenoid content and profile, the most influential factor appeared to be cultivar selection.
|
Page generated in 0.5134 seconds