Pigment Density Research Articles

Ethanol and caffeine age-dependently alter brain and retinal neurochemical levels without affecting morphology of juvenile and adult zebrafish (Danio rerio).

Adolescent alcohol exposure in humans is predictive of adult development of alcoholism. In rodents, caffeine pre-exposure enhances adult responsiveness to ethanol via a pathway targeted by both compounds. Embryonic exposure to either compound adversely affects development, and both compounds can alter zebrafish behaviors. Here, we evaluate whether co-exposure to caffeine and/or alcohol in adolescence exerts neurochemical changes in retina and brain. Zebrafish (Danio rerio) were given daily 20 min treatments to ethanol (1.5% v/v), caffeine (25-100 mg/L), or caffeine + ethanol for 1 week during mid-late adolescence (53-92 days post fertilization (dpf)) or early adulthood (93-142 dpf). Immediately after exposure, anatomical measurements were taken, including weight, heart rate, pigment density, length, girth, gill width, inner and outer eye distance. Brain and retinal tissue were subsequently collected either (1) immediately, (2) after a short interval (2-4d) following exposure, or (3) after a longer interval that included an acute 1.5% ethanol challenge. Chronic ethanol and/or caffeine exposure did not alter anatomical parameters. However, retinal and brain levels of tyrosine hydroxylase were elevated in fish sacrificed after the long interval following exposure. Protein levels of glutamic acid decarboxylase were also increased, with the highest levels observed in 70-79 dpf fish exposed to caffeine. The influence of ethanol and caffeine exposure on neurochemistry demonstrates specificity of their effects during postembryonic development. Using the zebrafish model to assess neurochemistry relevant to reward and anxiety may inform understanding of the mechanisms that reinforce co-addiction to alcohol and stimulants.

Effect of Garcinia mangostana L. skin decoct exposure on Zebrafish embryo Danio rerio (Hamilton, 1822)

Hypertension is one of the diseases with the highest prevalence in Indonesia and is the main cause of death in patients. Pregnant women have a risk of losing their baby due to hypertension or death. ACEI and ARB-type antihypertensive drugs are dangerous for pregnant women because they can cause fetal death. In ancient times, Indonesians have used plants as herbal medicines for generations. One of the plants that has medicinal properties is mangosteen skin (Garcinia mangostana L.) as an antihypertensive drug through its diuretic effects. However, the drugs consumed can have toxic effects if used in high concentrations. A teratogenic test is a toxic test that is specifically carried out to determine the presence of organ abnormalities in the fetus due to exposure to xenobiotic compounds. The zebrafish (Danio rerio) embryo was chosen as the research object because the chorion in the embryonic phase is transparent, so it is easy to observe. This study aimed to determine the effect of exposure to mangosteen rind decoction on zebrafish embryos' hatchability and spinal curvature. Observations were made using a Leica microscope with ANOVA data analysis. The observations showed that high treatment concentrations decreased heart rate, while high concentrations didn’t affect egg hatching rate, spine curvature, or pigment density.

Correlations between capillary density and degree of skin pigmentation in healthy children analysed by nailfold video capillaroscopy.

Nailfold video capillaroscopy (NVC) is a simple, non-invasive diagnostic tool but studies with normal values for capillary density in healthy children are rare. Ethnic background seems to play a role in capillary density; however, this is not well substantiated yet. In this work, we set out to evaluate influence of ethnic background/skin pigmentation and age on capillary density reading in healthy children. Secondary aim was to investigate whether there is a significant difference in density between different fingers within the same patient. Between 2016 and 2021, healthy children from schools around AUMC were approached, by convenience sampling. In this cross-sectional study, capillaroscopic images were obtained in a one-time videocapillaroscopy (×200 magnification) addressing the capillary density (i.e., number of capillaries per linear millimetre in the distal row). This parameter was compared to age, sex, ethnicity, skin pigment grade (I-III) and between eight different fingers, excluding the thumbs. Density differences were compared by ANOVAs. Correlations between capillary density and age were calculated with Pearson correlations. We investigated 145 healthy children with mean age of 11.03 years (SD 3.51). The range of capillary density was 4-11 capillaries per millimetre. We observed a lower capillary density in the 'grade II' (6.4±0.5 cap/mm, P<0.001) and 'grade III' (5.9±0.8 cap/mm, P<0.001) pigmented-classified groups compared to the 'grade I' group (7.0±0.7 cap/mm). We did not find a significant correlation between age and density in the overall group. The fifth fingers on both sides had a significantly lower density compared to the other fingers. Healthy children <18 years with higher degree of skin pigmentation show a significantly lower nailfold capillary density. In subjects with an African/Afro-Caribbean and North-African/Middle-Eastern ethnicity, a significantly lower mean capillary density was observed compared to subjects with the Caucasian ethnicity (P<0.001, and P<0.05, respectively. There were no significant differences between other ethnicities. No correlation was found between age and capillary density. The fifth fingers on both hands displayed lower capillary density compared to the other fingers. This needs to be taken into account when describing lower density in paediatric patients with connective tissue diseases.

The structure and assembly of reaction centre-light-harvesting 1 complexes in photosynthetic bacteria.

Chlorophototrophic organisms have a charge-separating reaction centre (RC) complex that receives energy from a dedicated light-harvesting (LH) antenna. In the purple phototrophic bacteria these two functions are embodied by the 'core' photosynthetic component, the RC-LH1 complex. RC-LH1 complexes sit within a membrane bilayer, with the central RC wholly or partly surrounded by a curved array of LH1 subunits that bind a series of bacteriochlorophyll (BChl) and carotenoid pigments. Decades of research have shown that the absorption of light initiates a cascade of energy, electron, and proton transfers that culminate in the formation of a quinol, which is subsequently oxidized by the cytochrome bc1 complex. However, a full understanding of all these processes, from femtosecond absorption of light to millisecond quinone diffusion, requires a level of molecular detail that was lacking until the remarkable recent upsurge in the availability of RC-LH1 structures. Here, we survey thirteen recently determined RC-LH1 assemblies, and we compare the precise molecular arrangements of pigments and proteins that allow efficient light absorption and the transfer of energy, electrons and protons. We highlight shared structural features, as well as differences that span the bound pigments and cofactors, the structures of individual subunits, the overall architecture of the complexes, and the roles of additional subunits newly identified in just one or a few species. We discuss RC-LH1 structures in the context of prior biochemical and spectroscopic investigations, which together enhance our understanding of the molecular mechanisms of photosynthesis in the purple phototrophic bacteria. A particular emphasis is placed on...

Comparison of a single treatment with a Q-switched ruby laser and a Q-switched Nd:YAG neodymium laser for blue and black tattoo removal

BACKGROUND: Black and blue tattoo pigment are the most commonly used colors and can be injected at different depths. The effectiveness of tattoo removal is related to the selected wavelength, type of laser, energy parameters, number of procedures performed. Q-switched (QS) ruby and neodymium (Nd:YAG) lasers are most effective in removing blue and black tattoos due to their high peak power and ability to break the pigment into small particles that are absorbed by the macrophage system. In the literature available to us, it was not possible to find data on comparative efficacy and adverse events in their application.&#x0D; AIM: comparison of single treatment of blue and black tattoos with QS ruby laser (wavelength 694 nm) and neodymium Nd:YAG laser (wavelength 1064 nm).&#x0D; MATERIALS AND METHODS: 35 patients with blue and black tattoos were included in our study. The tattoos were divided into two parts or two adjacent tattoos were used on the same part of the body with the same density and color of the tattoo pigment; one side was treated with a ruby laser and the other with a neodymium laser. The comparison took into account the instantaneous reaction, the result of processing and side effects. Statistical significance was set at a power level 0.05.&#x0D; RESULTS: Edema and erythema were more common immediately after ruby laser treatment (power 0.05). The neodymium QS laser lightened tattoos better than the ruby QS laser after a single treatment (0.05 power). There was no difference in side effects between the two types of lasers.&#x0D; CONCLUSIONS: Neodymium Nd:YAG QS laser shows more efficiency and fewer procedures when removing blue and black tattoos. The instantaneous reaction after treatment with this type of laser is less pronounced than after the ruby laser.

Extract of Bletilla formosana callus elevates cellular antioxidative activity via Nrf2/HO-1 signaling pathway and inhibits melanogenesis in zebrafish

BackgroundBletilla species are endangered terrestrial orchids used in natural skin care formulas in Asia for a long history. In order to explore the bioactivity potential of Bletilla species as a cosmetic ingredient in a sustainable resource manner, the callus of Bletilla formosana (Hayata) Schltr. was established and extracted by an eco-friendly supercritical fluid CO2 extraction (SFE-CO2) method. The intracellular reactive oxygen species (ROS) scavenging activity and antioxidation-related gene expression of the callus extract were evaluated in both Hs68 fibroblast cells and HaCaT keratinocytes. The melanogenesis-inhibitory effect was investigated in B16F10 melanoma cells and in an in vivo zebrafish model. ResultsThe calli of B. formosana were propagated for 10–15 generations with a consistent yellow friable appearance and then subjected to SFE-CO2 extraction to obtain a yellow pasty extract. Obvious intracellular ROS scavenging activity of the extract was detected in both Hs68 and HaCaT cells with 64.30 ± 8.27% and 32.50 ± 4.05% reduction at the concentration of 250 μg/mL. Moreover, marked expression levels of heme oxygenase-1 (HO-1) and (NAD(P)H) quinone oxidoreductase-1 (NQO1) genes were detected after 6-h and 24-h treatments. These results indicate the cellular antioxidative activity of B. formosana callus extract was probably activated via the nuclear factor erythroid 2-related factor 2 (Nrf2)/HO-1 signaling pathway. Melanogenesis-inhibitory effect of the extract was observed in α-MSH stimuli-inducing B16F10 cells with 28.46% inhibition of intracellular melanin content at the concentration of 50 μg/ml. The effect was confirmed with in vivo zebrafish embryos that showed a relative pigmentation density of 80.27 ± 7.98% at the concentration of 100 μg/mL without toxicity. ConclusionOur results shed light on a sustainable utilization of Bletilla species as a potential ingredient for skin.

Using equiluminance settings to estimate the cardinal chromatic directions for individuals.

Color information is processed by the retina and lateral geniculate along principal dimensions known as the cardinal directions of color space. Normal differences in spectral sensitivity can impact the stimulus directions that isolate these axes for individual observers and can arise from variation in lens and macular pigment density, photopigment opsins, photoreceptor optical density, and relative cone numbers. Some of these factors that influence the chromatic cardinal axes also impact luminance sensitivity. We modeled and empirically tested how well tilts on the individual's equiluminant plane are correlated with rotations in the directions of their cardinal chromatic axes. Our results show that, especially for the SvsLM axis, the chromatic axes can be partially predicted by luminance settings, providing a potential procedure for efficiently characterizing the cardinal chromatic axes for observers.

The Differential Contribution of Macular Pigments and Foveal Anatomy to the Perception of Maxwell’s Spot and Haidinger’s Brushes

The relationship of macular pigments and foveal anatomy to the perception of Maxwell's spot (MS) and Haidinger's brushes (HB) entoptic phenomena were investigated. Dual-wavelength-autofluorescence and OCT were used to define macular pigment density and foveal anatomy in 52 eyes. MS was generated by alternating unpolarized red/blue and red/green uniform field illumination. HB was generated by alternating the linear polarization axis of a uniform blue field. In Experiment 1, horizontal widths of MS and HB were measured using a micrometer system and compared with macular pigment densities and OCT-defined morphometry. MS radius (mean 1.4°) was significantly less than HB radius (mean 1.6°), with the spatial extent of both phenomena falling between the boundaries of the foveola and foveal pit. Multiple regression showed MS and HB radii to be significantly associated with the macular pigment spatial profile radius. HB radius, but not MS radius, was also significantly associated with foveolar morphometry. Experiment 2 compared perceptual profiles of MS with macular pigment distribution patterns and demonstrated close agreement. The size and appearance of MS is a direct indicator of macular pigment density and distribution. Measures of HB radii are less specific, with dependence on both macular pigment density and foveal structure.

Morphometric Characteristics of Axial Length of Eye in Population of the Southern Urals (according to “Ural Very Old Study” and “Ural Eye and Medical Study” Research)

INTRODUCTION: Currently, ametropias are the most important medical and social problem, which occupies one of the leading places in modern ophthalmology. Determination of the length of the anteroposterior eyeball axis (APEA) in myopia ― a type of ametropia directly associated with increase in the axial length of the eyeball ― is an objective method of its diagnosis and identification of progression. Due to the fact that myopia is a multifactorial disease, the study of correlation relationships of the length of the eyeball seems to be extremely relevant.&#x0D; AIM: To give a statistical assessment of the peculiarities of the axial length of the eyeball in the population of the Southern Urals, depending on age, gender and the respondents' settlement sites, and to determine the correlation relationships of this parameter.&#x0D; MATERIALS AND METHODS: The analysis was conducted on the base of Ufa Research Institute of Ophthalmology within large clinical and population studies Ural Eye and Medical Study (UEMS) and Ural Very Old Study (UVOS). Inclusion criteria: signing of voluntary consent to participation in the project, permanent residence in the territory of study; for inclusion in UEMS ― age from 40 to 85 years, in UVOS ― age above 85. UEMS study involved 5899 respondents, UVOS ― 1526. The study protocol suggested evaluation of 683 criteria, 293 of which were answers of respondents to questions of the questionnaire and the results of the general somatic examination, 355 criteria concerned the results of the ophthalmologic examination, 35 ― of laboratory tests. Axial length of the eyeball was measured by the method of ultrasound echo-biometry (A-scanning) (Ultra-compact A/B/P ultrasound system, Quantel Medical, France).&#x0D; RESULTS: The mean length of the APEA in the UEMS population was 23.31 1.08 mm, in the UVOS population ― 23.11 1.08 mm (p 0.001). The length of the eyeball axis was 23.31 1.08 mm in the age group 40-84 years and 23.11 1.08 mm in patients in the age category 85 years and older. The multivariate linear regression analysis in UEMS study showed the highest statistically significant association of APEA length with such factors as age (p 0.001), height (p 0.001), presence of arterial hypertension (p = 0.02), education level (p 0.001 ), intraocular pressure (IOP) (p 0.001), spherical refractive error (p0.001), depth of anterior chamber (p 0.001) and angle of anterior chamber (p 0.001), mosaicism of the eye fundus in the macular region (p 0.001), presence of myopic maculopathy (p 0.001), refractive power of the cornea (p 0.001), corneal volume (p 0.001), macular pigment density (p 0.001), thickness of peripapillary layer of nerve fibers (p 0.001), presence of the epiretinal membrane (p = 0.01). The multivariate linear regression analysis in UVOS study showed statistically significant association of the APEA length with such factors as height (p 0.001), education level (p = 0.002), corneal refractive power (p 0.001), spherical refraction error (p 0.001).&#x0D; CONCLUSION: In the population of the Southern Urals, statistically significant association of the length of the eyeball axis with such factors as height, education level, refractive power of the cornea and spherical refractive error, was demonstrated. Besides, in the population of UEMC study, there was also noted association with age, the presence of arterial hypertension, intraocular pressure, the depth of the anterior chamber and the angle of the anterior chamber, mosaicism of the eye fundus in the macular region, the presence of myopic maculopathy, corneal volume, density of macular pigment, thickness of the peripapillary layer of nerve fibers, presence of the epiretinal membrane.

Assessment of photoreceptor function with ultrafast retinal densitometry.

The optical density of visual pigment can be measured by imaging the dark-adapted eye while bleaching with visible light. This measurement can be made for individual photoreceptor cells using adaptive optics; however, activation of the phototransduction cascade imparts rapid changes in phase that modulate the signal via optical interference. This limits utility because data must be averaged over many experimental runs. Here we used a "flood" illuminated adaptive optics system at 4000 fps, bright light to achieve rapid bleaching, and broad illumination bandwidth to mitigate interference effects. Data were super-resolved using the natural motion of the eye to overcome the reduced pixel resolution of the ultrafast camera. This approach was applied to classify the trichromatic cone photoreceptor mosaic at a single fixation locus within the foveal region of 3 healthy subjects. Subjects were dark adapted for 6 minutes to replenish cone photopigment. This was followed either directly by imaging at 555 ± 50 nm, or by first pre-adapting the retina to 700 nm light to preferentially deplete "L" cone pigment. A total of 3,252 cones were classified as either "S", "M", or "L" type based on clustering of the intensity data observed under these two conditions. Mean classification probability ranged from 99.3 to 99.8%, with individual cell probabilities exceeding 95% in 97.0 to 99.2% of cones. Accuracy of cone classification peaked when using the first 10-30 ms of data, with significant reductions in accuracy noted with the inclusion of data from later times. Our results show that rapid bleaching and data acquisition significantly improve the robustness of cell-resolved densitometry.

Zebrafish brain and skull imaging based on polarization-sensitive optical coherence tomography.

Zebrafish brain imaging is very important for the study of brain disease and regeneration. We scanned the adult zebrafish brain before and after skull removal and monitored the recovery process of a head wound by polarization-sensitive optical coherence tomography (PS-OCT) in this paper. We analyzed the structure and polarization characteristics of the brain and skull in PS-OCT images, and found their internal microstructure can be clearly identified with the polarization information. Further, we estimated the pigment distribution of the skull area and found that the density of pigment in skull is a critical factor of affecting zebrafish brain in vivo polarization imaging. Our results demonstrated that more features of brain can be displayed by introducing the polarization information, and proved high-resolution PS-OCT will play a great potential role in studying the zebrafish brain and skull.

Effect of Agricultural Medium on the Qualitative Characteristics of Two Hybrids of Lettuce (Lactuca Sativa L.) in Hydroponics System

This study aimed to determine the most effective agricultural medium used in the growth and yield of lettuce in a hydroponics system under plastic house protected structure. Specifically, the study aimed to know the effect of using different agricultural medium such as peat moss, perlite and peat moss + perlite on growth and yield of two hybrids of lettuce. The experiment was conducted from 16 November 2020 to 21 January 2021 at Nursery of the Directorate of Agriculture Kirkuk / Kirkuk governate. The research used two factors, first factor is different of agricultural medium viz., peat moss, perlite and peat moss + perlite. Second factor is Two hybrids of lettuce viz, Fajer and Nader. The experiment was laid out according to the Randomized Complete Blocking Design (RCBD) with split plot arrangement in three replicates. The Duncan Multiple Range test at 5% level of probability was used for the comparison among means. Results showed that the lettuce planted in peat moss had the greatest content of the middle and internal leaves of chlorophyll. And the proportion of phosphorous, potassium, iron, nitrate and pigment Beta-carotene, percentage and density and refractive index of oil in the leaves. The data collected revealed that the Fajer hybrid recorded significant increment in all studied characteristics except content of the external leaves of chlorophyll and the percentage of nitrogen, protein and sugars in the leaves. Fajer hybrid planted in peat moss obtained maximum values in all studied characteristics compared to other treatments. On contrast, Nader hybrid planted in peat moss + perlite obtained minimum values in these characteristics.

New Corrosion Inhibitors Based on Perylene Units in Epoxy Ester Resin Coatings

Four new compounds from perylene dianhydride were prepared and tested for their anti-corrosion properties. Dizinc salt of perylene-3,4,9,10-tetracarboxylic acid and dimagnesium salts of perylene-3,4,9,10-tetracarboxylic acid, 5,5′-(1,3,8,10-tetraoxo-1,3,8,10-tetrahydroanthra[2,1,9-def:6,5,10-d′e′f′] diisoquinoline-2,9-diyl) bis(2-hydroxybenzoic acid) and N,N′-bis[3,3′-(dimethylamino)propylamine]-3,4,9,10-perylenediimide were characterized by analytical methods (SEM, EDX, X-ray) and parameters used in the field of paints (density, oil number and critical volume concentrations of pigment). The pigments (in a pigment volume concentration series) were used to prepare paints also containing a perylene C26H14N2O4 (Compound I) derivative pigment plus inert titanium dioxide to maintain a constant concentration of solids in the paint film. A mixture containing zinc nitroisophthalate and both the perylene derivative and titanium dioxide served as the reference material. The paints were applied to steel panels in two layers with a ruler. The organic coatings were subjected to electrochemical measurements and accelerated cyclic corrosion tests. The highest corrosion resistance was found for the coating containing C24H8O8Mg2. Superior to the coating containing either C26H14N2O4 or the conventional corrosion inhibitor C8H5N06-Zn, this pigment type acted mainly by a mechanism based on the compound’s complexation capacity at the metallic surface/organic coating/corrosion medium interface. The organic coatings containing perylene acid salts also attained high mechanical resistance.

Correlating Ocular Physiology and Visual Function with Mild Cognitive Loss in Senior Citizens in Taiwan.

Purpose: The transition of Taiwan from an aging to a super-aging society has come with a cost as more elderly now suffer from cognitive impairment. The main purpose of our study was to investigate if early detection can be developed so that timely intervention can be instituted. We analyzed the correlation of cognitive function with ocular physiology and visual functions between senior citizens aged 60 years or older in Taiwan. Methods: Thirty-six healthy subjects were recruited for the study. Addenbrooke’s cognitive examination III (ACE-III), binocular functions (including objective and subjective refraction, distance and near dissociated phoria, stereopsis, contrast sensitivity, adult developmental eye movement (ADEM), and ocular physiology (by using optical coherence tomography, OCT, and macular pigment measurement, MPS) were performed, and the data were analyzed via independent t-test, chi-square test, Pearson correlation, linear regression, and ROC (receiver operating characteristic) curve. Results: Data analysis showed that (1) patients with poor eye movement had a strong correlation with the total score and all dimensions of cognitive functions, (2) the thickness of the macula had a strong correlation with attention and memory, and (3) patients with poor eye movement and poor stereopsis in combination with thinner inferior macula appeared to have lower cognitive abilities. Discussion and Conclusions: Cognitive dysfunction is not readily identified during the early stage of cognitive decline. The use of simple and inexpensive ADEM or stereopsis test and comparing the OCT results that are popular in optometry clinics for reference can be diagnostic in identifying patients with mild cognitive impairments. With the combined use of macular pigment density or retinal thickness measurements, it was possible to effectively predict the early degradation of cognition.

Kelarutan Zat Warna Organik dalam Gelasi Mikroemulsi Water In Oil dari Sistem Air, Surfaktan Nonionik (Brij 35) dan Pentanol

Research on solubility from organic pigments of turmeric (Curcuma longa Linn) and telang flower (Clitoria ternatea L.) in water-in-oil microemulsion gelation on system of water, nonionic surfactant (Brij 35) and pentanol has been studied. The purpose of this research was the preparation of water-in-oil microemulsion gelation, determines solubility, density, and bias index of organic pigments in water-in-oil microemulsion gelation on system of water, nonionic surfactant (Brij 35) and pentanol. The method used is the sol-gel method. The solubility in water-in-oil microemulsion gelation of turmeric is 2,41832% (pH 4,5) and 2,61402% (pH 9,5) and telang flower is 1,21274% (pH 4,5) and 1,6136% (pH 9,5). The bias index of turmeric is 1,4024 (pH 4.5) and 1,4034 (pH 9,5) and telang flower is 1,4004 (pH air 4,5) and 1,4014 (pH 9,5).The density of turmeric is 0,88778g/cm3 (pH 4,5) and 0,88912g/cm3 (pH 9,5) and telang flower is 0,8793g/cm3 (pH 4,5) and 0,8872g/cm3 (pH 9,5).

Demonstration of local adaptation in maize landraces by reciprocal transplantation.

Populations are locally adapted when they exhibit higher fitness than foreign populations in their native habitat. Maize landrace adaptations to highland and lowland conditions are of interest to researchers and breeders. To determine the prevalence and strength of local adaptation in maize landraces, we performed a reciprocal transplant experiment across an elevational gradient in Mexico. We grew 120 landraces, grouped into four populations (Mexican Highland, Mexican Lowland, South American Highland, South American Lowland), in Mexican highland and lowland common gardens and collected phenotypes relevant to fitness and known highland‐adaptive traits such as anthocyanin pigmentation and macrohair density. 67k DArTseq markers were generated from field specimens to allow comparisons between phenotypic patterns and population genetic structure. We found phenotypic patterns consistent with local adaptation, though these patterns differ between the Mexican and South American populations. Quantitative trait differentiation (Q ST) was greater than neutral allele frequency differentiation (F ST) for many traits, signaling directional selection between pairs of populations. All populations exhibited higher fitness metric values when grown at their native elevation, and Mexican landraces had higher fitness than South American landraces when grown in these Mexican sites. As environmental distance between landraces’ native collection sites and common garden sites increased, fitness values dropped, suggesting landraces are adapted to environmental conditions at their natal sites. Correlations between fitness and anthocyanin pigmentation and macrohair traits were stronger in the highland site than the lowland site, supporting their status as highland‐adaptive. These results give substance to the long‐held presumption of local adaptation of New World maize landraces to elevation and other environmental variables across North and South America.

Determination of the optical density of macular pigment: clinical value

The density of macular pigment in the central retina is the total concentration of lutein, zeaxanthin and meso-zeaxanthin. Normally, the average value of the optical density of macular pigment can vary significantly as it depends on the person's lifestyle, the total amount of pigment in the body, nutrition, gender, age, as well as concomitant diseases such as diabetes, obesity, arterial hypertension. Differences in the level of optical density of macular pigment between different countries were revealed and it was showed that this parameter drops in cases of retinal pathology, cataract, glaucoma, myopia, macular degeneration, or diabetic macular edema. The level of macular pigment may be considered as a significant diagnostic criterion in many ophthalmic pathologies, so any changes of this parameter require attentive consideration.

An overview of the science and art of encapsulated pigments: Preparation, performance and application

AbstractA successfully encapsulated pigment requires dispersants, pigment and a dispersion medium to build a thin layer of polymer over individual pigment particles. The stability of encapsulated dispersion is aided by the absorption of stabilising molecules on the surface. The stabilising molecules function by steric hindrance or Coulomb‐repulsion forces, which prevent the encapsulated pigments from advancing too close to each other for attractive forces to cause agglomeration. Unlike flocculation, agglomeration results in a cementitious network structure that is not easily redispersed by shear forces, hence the need for effective dispersion of encapsulated pigment intended for engineering applications. Besides dispersion forces, the quality of pigment dispersion, the pigment particle size, pigment density, viscosity of the dispersion, and the method of producing the pigment microcapsules, also affect the efficiency and the quality of encapsulated pigment dispersions. This article, therefore, provides up‐to‐date information on the various pigment encapsulation methods (with specific emphasis on phase separation, in situ polymerisation, emulsion and mini‐emulsion polymerisation, the sol‐gel method, inclusion complexation and layer‐by‐layer assembly), and also reviews the performance, the evaluation/test methods and applications of encapsulated pigments. This review provides important insight into the science and art of encapsulated pigment preparation for pigment dispersion technologists, researchers and consumers of pigment products in different fields of endeavour.

Prevalence of Age-Related Macular Degenerative Disorder Due to Poor Dietary Habits

Globally, food consumption patterns are changed and trends shift to poor dietary habits leading to poor health and food insecurity. Visual health is normally down after a certain age period or with the progression of individual age but now the trends are observed increased visual disorders in early age periods too. The prevalence of age related macular degenerative disorders are increasing mainly due to diets that are deficient in carotenoids like lutein or other essential nutrients that are necessary to improve visual health. Lutein has the potential to directly absorb and deposit in eye macula that even can restore macular pigment density and recover visual strength. Numerous research has proved that diet naturally rich with carotenoids or supplemented has a substantial beneficial impact against age related macular degenerative disorders in all age groups.

A Single-Center Pilot Study to Classify Signs of Dorsal Hand Aging Using 3 Grading Scales.

BackgroundWhile validated scales must be created in order to systemically evaluate patients and quantify outcomes of aesthetic hand treatments, scales currently available are limited to the analysis of volume loss alone.ObjectivesThe purpose of this study was to develop 3 validated scales for the assessment of dorsal hand aging that also take into consideration wrinkling and pigmentation.MethodsFifty (50) healthy volunteers (40 females and 10 males) with Fitzpatrick skin types I-IV were recruited, and standard photographs of their left and right dorsal hands were taken with a Nikon D7100 (Nikon; Minato, Tokyo, Japan) camera. Using 25 randomized photographs, 11 plastic surgery physicians (3 chief residents, 6 senior residents, and 2 aesthetic surgery fellows) were trained on the 3 scales under investigation as well as the already-validated Merz Hand Grading Scale (MHGS). The evaluators then viewed the remaining 75 photographs independently and assigned a grade for each of the 4 scales to each photograph. Inter-rater variability was calculated for each scale.ResultsThe Kappa score for the MHGS was 0.25, indicating fair agreement; 0.40 for wrinkle scale, indicating fair agreement; and 0.48 and 0.46 for the pigmentation density and intensity scales, respectively, indicating moderate agreement (P < 0.001).ConclusionsThe results show that after receiving training, the inter-rater agreement for the 3 scales under investigation was similar or slightly higher than that for the MHGS. These 3 photographic classification systems can be used consistently and reliably to characterize multiple signs of dorsal hand aging.Level of Evidence: 2