Displaying publications 61 - 80 of 100 in total

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  1. Nugroho H, Fadzil MH, Yap VV, Norashikin S, Suraiya HH
    PMID: 18002737
    In this paper, we describe an image processing scheme to analyze and determine areas of skin that have undergone repigmentation in particular, during the treatment of vitiligo. In vitiligo cases, areas of skin become pale or white due to the lack of skin pigment called melanin. Vitiligo treatment causes skin repigmentation resulting in a normal skin color. However, it is difficult to determine and quantify the amount of repigmentation visually during treatment because the repigmentation progress is slow and moreover changes in skin color can only be discerned over a longer time frame typically 6 months. Here, we develop a digital image analysis scheme that can identify and determine vitiligo skin areas and repigmentation progression on a shorter time period. The technique is based on principal component analysis and independent component analysis which converts the RGB skin image into a skin image that represent skin areas due to melanin and haemoglobin only, followed by segmentation process. Vitiligo skin lesions are identified as skin areas that lack melanin (non-melanin areas). In the initial studies of 4 patients, the method has been able to quantify repigmentation in vitiligo lesion. Hence it is now possible to determine repigmentation progression objectively and treatment efficacy on a shorter time cycle.
    Matched MeSH terms: Skin Pigmentation*
  2. Hedin CA, Axéll T
    J Oral Pathol Med, 1991 Jan;20(1):8-12.
    PMID: 2002444
    At the faculties of dentistry in Chiang Mai, Thailand (CM), and Kuala Lumpur, Malaysia (KL), 234 and 233 consecutive out-patients were interviewed concerning tobacco and chewing habits and examined for the presence of oral melanin pigmentation. Tobacco was regularly used by 32% and 28% of the studied populations in CM and KL. Cigarette smoking was the predominant habit, but the chewing of betel and tea leaves (miang) and the smoking of banana leaf cigars (khi yo) was also registered. The genetically acquired pigmentation dominated. Although nearly all non-tobacco users in the Malay and Indian populations had oral melanin pigmentation, it was found that tobacco smokers had significantly more oral surfaces pigmented than non-tobacco users. Among Thais, the percentage of pigmented individuals was significantly higher among tobacco smokers. It was concluded that tobacco smoking stimulates oral melanocytes to a higher melanin production also in dark-skinned ethnic groups.
    Matched MeSH terms: Pigmentation*
  3. Sanders KL, Malhotra A, Thorpe RS
    J Evol Biol, 2004 Jul;17(4):721-31.
    PMID: 15271071
    We analyse molecular and phenotypic evolution in a group of taxonomically problematic Indomalayan pitvipers, the Trimeresurus sumatranus group. Mitochondrial DNA sequencing provides a well-resolved phylogeny, with each species representing a distinct lineage. Multivariate morphological analysis reveals a high level of phenotypic differentiation, which is congruent between the sexes but does not reflect phylogenetic history. An adaptive explanation for the observed pattern of differentiation is supported by independent contrasts analysis, which shows significant correlations between current ecology and the characters that most account for the variation between taxa, including those that are presently used to identify the species. Reduced precipitation and altitude, and increased temperature, are correlated with higher numbers of scales on the head, body and tail. It is hypothesized that scale number plays an important role in heat and water exchange by influencing the area of exposed of interstitial skin, and that colour pattern variation reflects selection pressures involving camouflage and thermoregulation. Ecological convergence in traits used for classification is found to have important implications for species identification where taxa are distributed over varying environments.
    Matched MeSH terms: Pigmentation/physiology
  4. Iijima C, Wong CP, Nugroho AE, Sotozono Y, Someya S, Hirasawa Y, et al.
    J Nat Med, 2016 Oct;70(4):702-7.
    PMID: 27357963 DOI: 10.1007/s11418-016-1016-y
    The ceramicines, a series of limonoids from Chisocheton ceramicus (Meliaceae), were evaluated for anti-melanin deposition activity on α-melanocyte stimulating hormone (α-MSH) and 3-isobutyl-1-methylxanthine (IBMX)-treated B16-F10 melanoma cell, and several ceramicines were found to be active. The structure-activity relationship of ceramicines as anti-melanin deposition inhibitors was deduced. Furthermore, the mechanism of anti-melanin deposition activity of ceramicine B, a major constituent of C. ceramicus that showed potent anti-melanin deposition activity, was investigated. Tyrosinase enzymatic activity and tyrosinase mRNA expression were not affected by ceramicine B. The anti-melanin deposition activity of ceramicine B was shown to be related to the downregulation of tyrosinase protein expression. These results suggest that ceramicines have potential to be used as depigmentation agents.
    Matched MeSH terms: Pigmentation/drug effects
  5. Shah S, Chew SK
    J Cosmet Dermatol, 2018 Oct;17(5):830-839.
    PMID: 29193788 DOI: 10.1111/jocd.12435
    BACKGROUND: Skin hyperpigmentation is the darkening of skin due to the increased production of melanin in the body.

    OBJECTIVES: To evaluate the efficacy and safety of a botanical-based Rosa E pigmentation serum in healthy fair skin female volunteers with wrinkles, skin tone, and pigmentation.

    METHODS: This was a single-arm, open label study conducted in healthy Indian females; 18 subjects aged 30-55, having fair Caucasian-like skin with at least 2 dark skin pigments with facial wrinkles diagnosed by dermatologist were selected. Rosa E pigmentation serum was applied twice a day for 84 days. Effect was evaluated by (i) instrumental technique (spectrophotometer® 2600D), (ii) clinically by dermatologist regarding product efficacy (skin tone, antiwrinkle, pigmentation), and (iii) volunteers self-evaluation.

    RESULTS: The L* value of spectrophotometer reading represents lightness in the skin pigment. Reduction in the pigment was reported from day 14, with significant reductions observed till day 84 compared with baseline. Significant (P < .0001) skin pigmentation lightening was seen on day 14 (1.11) vastly improving on day 84 (1.94) based on photographic assessments. The significant reduction in skin pigment was 76.85%, Felix von Luschan skin color score was 30.24% (P < .0001) with a 7.38-fold reduction in skin tone and 57% reduction in facial wrinkles at day 84 from baseline.

    CONCLUSIONS: Rosa E pigmentation serum was found safe and effective in significant reduction in skin pigments, improvement of skin tone, and antiwrinkle properties instrumentally, clinically, and self-evaluation by volunteers. In these evaluations, best results were seen the longer the Rosa E was used.

    Matched MeSH terms: Skin Pigmentation/drug effects*
  6. Tan KW, Stephen ID
    Perception, 2013;42(7):733-41.
    PMID: 24344549
    Human facial skin colour reflects individuals' underlying health (Stephen et al 2011 Evolution & Human Behavior 32 216-227); and enhanced facial skin CIELab b* (yellowness), a* (redness), and L* (lightness) are perceived as healthy (also Stephen et al 2009a International Journal of Primatology 30 845-857). Here, we examine Malaysian Chinese participants' detection thresholds for CIELab L* (lightness), a* (redness), and b* (yellowness) colour changes in Asian, African, and Caucasian faces and skin coloured patches. Twelve face photos and three skin coloured patches were transformed to produce four pairs of images of each individual face and colour patch with different amounts of red, yellow, or lightness, from very subtle (deltaE = 1.2) to quite large differences (deltaE = 9.6). Participants were asked to decide which of sequentially displayed, paired same-face images or colour patches were lighter, redder, or yellower. Changes in facial redness, followed by changes in yellowness, were more easily discriminated than changes in luminance. However, visual sensitivity was not greater for redness and yellowness in nonface stimuli, suggesting red facial skin colour special salience. Participants were also significantly better at recognizing colour differences in own-race (Asian) and Caucasian faces than in African faces, suggesting the existence of cross-race effect in discriminating facial colours. Humans' colour vision may have been selected for skin colour signalling (Changizi et al 2006 Biology Letters 2 217-221), enabling individuals to perceive subtle changes in skin colour, reflecting health and emotional status.
    Matched MeSH terms: Skin Pigmentation/physiology*
  7. Jalili M, Jinap S, Son R
    PMID: 21416415 DOI: 10.1080/19440049.2010.551300
    The effect of 18 different chemicals, which included acidic compounds (sulfuric acid, chloridric acid, phosphoric acid, benzoic acid, citric acid, acetic acid), alkaline compounds (ammonia, sodium bicarbonate, sodium hydroxide, potassium hydroxide, calcium hydroxide), salts (acetate ammonium, sodium bisulfite, sodium hydrosulfite, sodium chloride, sodium sulfate) and oxidising agents (hydrogen peroxide, sodium hypochlorite), on the reduction of aflatoxins B(1), B(2), G(1) and G(2) and ochratoxin A (OTA) was investigated in black and white pepper. OTA and aflatoxins were determined using HPLC after immunoaffinity column clean-up. Almost all of the applied chemicals showed a significant degree of reduction on mycotoxins (p < 0.05). The lowest and highest reduction of aflatoxin B(1), which is the most dangerous aflatoxin, was 20.5% ± 2.7% using benzoic acid and 54.5% ± 2.7% using sodium hydroxide. There was no significant difference between black and white peppers (p < 0.05).
    Matched MeSH terms: Pigmentation/drug effects
  8. Oh MJ, Hamid MA, Ngadiran S, Seo YK, Sarmidi MR, Park CS
    Arch. Dermatol. Res., 2011 Apr;303(3):161-70.
    PMID: 20981431 DOI: 10.1007/s00403-010-1089-5
    Ficus deltoidea (Mas cotek) water extract has been widely used for woman health in Malaysia. Our investigation focused to identify anti-melanogenic efficacy of F. deltoidea since it has been known to have strong anti-oxidant activities. Anti-melanogenic effect of F. deltoidea extract was analyzed using cultured B16F1 melanoma cells. Cytotoxicity of the extract was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and determined the highest concentration of the extract that did not affect cell viability as 0.1% (w/v). α-MSH-induced melanin synthesis was significantly inhibited with dose-dependent manner by treatment of F. deltoidea leave extract, which was comparable to that of kojic acid. The extract directly inhibited mushroom tyrosinase activity and intracellular tyrosinase activity of B16F1 as well. The inhibition of intracellular tyrosinase activity was found to be exerted at the protein expression level when analyzed by immunoblot and tyrosinase zymography. The expression of microphthalmia-associated transcription factor (MITF) was also reduced by the F. deltoidea extract. In conclusion, F. deltoidea extract has strong anti-melanogenic activity that is exerted by direct inhibition of tyrosinase enzyme activity and by down-regulation of the expression of genes involved in the melanogenesis pathways. Collectively, data shown in this study strongly suggest that F. deltoidea extract has potential to be used as a novel depigmenting agent for cosmetics.
    Matched MeSH terms: Pigmentation Disorders/drug therapy*
  9. Sangappillai V, Nadarajah K
    Int J Mol Sci, 2020 Sep 30;21(19).
    PMID: 33007862 DOI: 10.3390/ijms21197224
    Lipid biosynthesis produces glycerol, which is important in fueling turgor pressure necessary for germination and penetration of plant host by fungi. As the relationship between pathogenicity and the lipid biosynthetic pathway is not fully understood, we have elucidated the role of the fatty acid synthase beta subunit dehydratase (FAS1) gene in lipid biosynthesis. The FAS1 gene was silenced through homologous double crossover in Magnaporthe oryzae strain S6 to study the effect on lipid biosynthesis. The vegetative growth of Δfas1 mutants show the highest drop on oleic acid (between 10 and 50%), while the mycelial dry weight of mutants dropped significantly on all media. Conidiation of FAS1 mutants show a ~10- and ~5-fold reduction on oatmeal and Potato Dextrose Agar (PDA), respectively. Mutants formed mycelium that were mildly pigmented, indicating that the deletion of FAS1 may have affected melanin biosynthesis. Biochemical and gene expression studies concluded that the fatty acid degradation pathway might have been interrupted by FAS1 deletion. FAS1 mutants showed no enzyme activity on glucose or olive oil, suggesting that the mutants may lack functional peroxisomes and be defective in β-oxidation of fatty acids, hence explaining the reduced lipid deposits in the spores.
    Matched MeSH terms: Pigmentation/genetics
  10. Lajis AFB, Ariff AB
    J Cosmet Dermatol, 2019 Jun;18(3):703-727.
    PMID: 30866156 DOI: 10.1111/jocd.12900
    Human skin pigmentation is a result of constitutive and facultative pigmentation. Facultative pigmentation is frequently stimulated by UV radiation, pharmacologic drugs, and hormones whereby leads to the development of abnormal skin hyperpigmentation. To date, many state-of-art depigmenting compounds have been studied using in vitro model to treat hyperpigmentation problems for cosmetic dermatological applications; little attention has been made to compare the effectiveness of these depigmenting compounds and their mode of actions. In this present article, new and recent depigmenting compounds, their melanogenic pathway targets, and modes of action are reviewed. This article compares the effectiveness of these new depigmenting compounds to modulate several melanogenesis-regulatory enzymes and proteins such as tyrosinase (TYR), TYR-related protein-1 (TRP1), TYR-related protein-2 (TRP2), microphthalmia-associated transcription factor (MITF), extracellular signal-regulated kinase (ERK) and N-terminal kinases (JNK) and mitogen-activated protein kinase p38 (p38 MAPK). Other evidences from in vitro assays such as inhibition on melanosomal transfer, proteasomes, nitric oxide, and inflammation-induced melanogenesis are also highlighted. This article also reviews analytical techniques in different assays performed using in vitro model as well as their advantages and limitations. This article also provides an insight on recent finding and re-examination of some protocols as well as their effectiveness and reliability in the evaluation of depigmenting compounds. Evidence and support from related patents are also incorporated in this present article to give an overview on current patented technology, latest trends, and intellectual values of some depigmenting compounds and protocols, which are rarely highlighted in the literatures.
    Matched MeSH terms: Skin Pigmentation/drug effects*
  11. Jamil NA, Gray SR, Fraser WD, Fielding S, Macdonald HM
    Osteoporos Int, 2017 04;28(4):1433-1443.
    PMID: 28083666 DOI: 10.1007/s00198-016-3901-3
    The current study examined the relationship between vitamin D status and muscle strength in young healthy adults: residents (>6 months) and newcomers (0-3 months), originally from sunny climate countries but currently living in the northeast of Scotland. Our longitudinal data found a positive, albeit small, relationship between vitamin D status and knee extensor isometric strength.

    INTRODUCTION: Vitamin D has been suggested to play a role in muscle health and function, but studies so far have been primarily in older populations for falls prevention and subsequent risk of fractures.

    METHODS: Vitamin D status was assessed in a healthy young adults from sunny climate countries (n = 71, aged 19-42 years) with 56% seen within 3 months of arriving in Aberdeen [newcomers; median (range) time living in the UK = 2 months (9-105 days)] and the remainder resident for >6 months [residents; 23 months (6-121 months)]. Participants attended visits every 3 months for 15 months. At each visit, fasted blood samples were collected for analysis of serum 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), carboxy-terminal collagen crosslinks (CTX) and N-terminal propeptide of type I collagen (P1NP). Maximal voluntary contractions (MVC) were performed for grip strength (both arms) and for maximal isometric strength of the knee extensors (right knee).

    RESULTS: There were small seasonal variations in 25(OH)D concentrations within the newcomers and residents, but no seasonal variation in bone turnover markers. There was a positive, albeit small, association between 25(OH)D and knee extensor maximal isometric strength. Mixed modelling predicted that for each 1 nmol/L increase in 25(OH)D, peak torque would increase by 1 Nm (p = 0.04).

    CONCLUSIONS: This study suggests that vitamin D may be important for muscle health in young adults migrating from sunnier climates to high latitudes, yet the potential effect is small.

    Matched MeSH terms: Skin Pigmentation/physiology
  12. Wang LM, Bu HY, Song FB, Zhu WB, Fu JJ, Dong ZJ
    PMID: 31310814 DOI: 10.1016/j.cbpa.2019.110529
    Red tilapia has become more popular for aquaculture production in China in recent years. However, the pigmentation differentiation that has resulted from the process of genetic breeding and skin color variation during the overwintering period are the main problems limiting the development of commercial culture. The genetic basis of skin color differentiation is still not understood. Solute carrier family 7 member 11 (slc7a11) has been identified to be a critical genetic regulator of pheomelanin synthesis in the skin of mammals. However, little information is available about its molecular characteristics, expression, location and function in skin color differentiation of fish. In this study, three complete cDNA sequences (2159 bp, 2190 bp and 2249 bp) of slc7a11 were successfully isolated from Malaysian red tilapia, encoding polypeptides of 492, 525 and 492 amino acids respectively. Quantitative real-time PCR demonstrated that slc7a11 mRNA expression is high in the ventral skin of PR (pink with scattered red spots) fish. Immunofluorescence analysis revealed that xCT (the protein encoded by slc7a11) was concentrated mainly in the cytoplasm and nucleus of both the dorsal and ventral skin cells of fish. After RNA interference of slc7a11, slc7a11 and cbs mRNA expressions decreased, but the tyr mRNA expression increased in the skin of fish. Results suggest that slc7a11 plays an important role in skin color formation and differentiation of red tilapia through the melanogenesis pathway.
    Matched MeSH terms: Skin Pigmentation/genetics*
  13. Coppard SE, Jessop H, Lessios HA
    Sci Rep, 2021 Aug 16;11(1):16568.
    PMID: 34400682 DOI: 10.1038/s41598-021-95872-0
    The sea urchins Echinothrix calamaris and Echinothrix diadema have sympatric distributions throughout the Indo-Pacific. Diverse colour variation is reported in both species. To reconstruct the phylogeny of the genus and assess gene flow across the Indo-Pacific we sequenced mitochondrial 16S rDNA, ATPase-6, and ATPase-8, and nuclear 28S rDNA and the Calpain-7 intron. Our analyses revealed that E. diadema formed a single trans-Indo-Pacific clade, but E. calamaris contained three discrete clades. One clade was endemic to the Red Sea and the Gulf of Oman. A second clade occurred from Malaysia in the West to Moorea in the East. A third clade of E. calamaris was distributed across the entire Indo-Pacific biogeographic region. A fossil calibrated phylogeny revealed that the ancestor of E. diadema diverged from the ancestor of E. calamaris ~ 16.8 million years ago (Ma), and that the ancestor of the trans-Indo-Pacific clade and Red Sea and Gulf of Oman clade split from the western and central Pacific clade ~ 9.8 Ma. Time since divergence and genetic distances suggested species level differentiation among clades of E. calamaris. Colour variation was extensive in E. calamaris, but not clade or locality specific. There was little colour polymorphism in E. diadema.
    Matched MeSH terms: Pigmentation*
  14. Quah CC, Kim KH, Lau MS, Kim WR, Cheah SH, Gundamaraju R
    PMID: 25392585
    BACKGROUND: The preference for a fairer skin-tone has become a common trend among both men and women around the world. In this study, seaweeds Sargassum polycystum and Padina tenuis were investigated for their in vitro and in vivo potentials in working as skin whitening agents. Seaweed has been used as a revolutionary skin repairing agent in both traditional and modern preparations. The high antioxidant content is one of the prime reasons for its potent action. It has been employed in traditional Chinese and Japanese medicine. For centuries, most medical practitioners in the Asian cultures have known seaweed as an organic source of vitamins, minerals, fatty acids like omega-3 and omega-6 and antioxidants. The present objective of the study was to evaluate the potent dermal protective effect of the two seaweeds Sargassum polycystum and Padina tenuis on human cell lines and guinea pigs.

    MATERIAL AND METHODS: Seaweeds were extracted with ethanol and further fractionated with hexane, ethyl acetate and water. The extracts were tested for mushroom tyrosinase inhibitory activity, cytotoxicity in human epidermal melanocyte (HEM), and Chang cells. Extracts with potent melanocytotoxicity were formulated into cosmetic cream and tested on guinea pigs in dermal irritation tests and de-pigmentation assessments.

    RESULTS: Both Sargassum polycystum and Padina tenuis seaweeds showed significant inhibitory effect on mushroom tyrosinase in the concentration tested. SPEt showed most potent cytotoxicity on HEM (IC50 of 36µg/ml), followed by SPHF (65µg/ml), and PTHF (78.5µg/ml). SPHF and SPEt reduced melanin content in skin of guinea pigs when assessed histologically.

    CONCLUSION: SPEt, SPHF and PTHF were able to inhibit HEM proliferation in vitro, with SPHF being most potent and did not cause any dermal irritation in guinea pigs. The results obtained indicate that SPHF is a promising pharmacological or cosmetic agent.

    Matched MeSH terms: Pigmentation/drug effects*
  15. Ahmad Fadzil MH, Ihtatho D, Mohd Affandi A, Hussein SH
    J Med Eng Technol, 2009;33(7):516-24.
    PMID: 19639508 DOI: 10.1080/07434610902744074
    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.
    Matched MeSH terms: Skin Pigmentation
  16. Fadzil MH, Norashikin S, Suraiya HH, Nugroho H
    J Med Eng Technol, 2009;33(2):101-9.
    PMID: 19205989 DOI: 10.1080/03091900802454459
    This paper describes an image analysis technique that objectively measures skin repigmentation for the assessment of therapeutic response in vitiligo treatments. Skin pigment disorders due to the abnormality of melanin production, such as vitiligo, cause irregular pale patches of skin. The therapeutic response to treatment is repigmentation of the skin. However the repigmentation process is very slow and is only observable after a few months of treatment. Currently, there is no objective method to assess the therapeutic response of skin pigment disorder treatment, particularly for vitiligo treatment. In this work, we apply principal component analysis followed by independent component analysis to represent digital skin images in terms of melanin and haemoglobin composition respectively. Vitiligo skin areas are identified as skin areas that lack melanin (non-melanin areas). Results obtained using the technique have been verified by dermatologists. Based on 20 patients, the proposed technique effectively monitored the progression of repigmentation over a shorter time period of six weeks and can thus be used to evaluate treatment efficacy objectively and more effectively.
    Matched MeSH terms: Skin Pigmentation
  17. Chong LK, Ong AH, Tan SG, Taranjeet KA, Peris MM, Sana AM, et al.
    Biochem Genet, 2014 Jun;52(5-6):283-95.
    PMID: 24535156 DOI: 10.1007/s10528-014-9647-8
    In this study the genetic diversity of local freshwater leeches (Hirudinaria spp.) was inferred using mtDNA COI gene analysis and compared with the gross external variations of 26 freshwater leech specimens obtained from the wild and leech farms. Based on a neighbor-joining tree generated from 516 COI base sequences, four distinct clades of Hirudinaria were seen with interspecific genetic divergence in the range of 7.6-14.5%. The external morphological variations based on the presence of stripes, location of gonopores, and anus separated the samples into four morphologically distinct groups matching the four clades obtained from the molecular data. Two black stripes at the ventral region were observed only in specimens found clustered with clades that contained the GenBank-reported H. manillensis, whereas the brown or dark green coloration without stripes on the ventral region was seen in samples that clustered with H. javanica and H. bpling clades.
    Matched MeSH terms: Pigmentation
  18. Zuha RM, Supriyani M, Omar B
    Trop Biomed, 2008 Apr;25(1):17-22.
    PMID: 18600200
    Analysis on fly artifacts produced by forensically important blowfly, Chrysomya megacephala (Fabricius) (Diptera:Calliphoridae), revealed several unique patterns. They can be divided into fecal spots, regurgitation spots and swiping stains. The characteristics of fecal spots are round with three distinct levels of pigmentation; creamy, brownish and darkly pigmented. Matrix of the spots appears cloudy. The round spots are symmetrical and non-symmetrical, delineated by irregular and darker perimeter which only visible in fairly colored fecal spots. Diameter of these artifacts ranged from 0.5 mm to 4 mm. Vomit or regurgitation spots are determined by the presence of craters due to sucking activity of blowflies and surrounded by thickly raised and darker colored perimeter. The size of these specks ranged from 1 mm to 2 mm. Matrix of the spots displays irregular surface and reflective under auxiliary microscope light. Swiping stains due to defecation by flies consists of two distinguishable segments, the body and tail. It can be seen as a tear drop-like, sperm-like, snake-like and irregular tadpole-like stain. The direction of body and tail is inconsistent and length ranged between 4.8 mm to 9.2 mm. A finding that should be highlighted in this observation is the presence of crater on tadpole-like swiping stain which is apparent by its raised border characteristic and reflective under auxiliary microscope light. The directionality of this darkly brown stain is random. This unique mix of regurgitation and swiping stain has never been reported before. Highlighting the features of artifacts produced by flies would hopefully add our understanding in differentiating them from blood spatters produced from victims at crime scenes.
    Matched MeSH terms: Pigmentation
  19. Khoo, Gideon, Lim, Tit Meng, Phang, Violet Pan Eng
    MyJurnal
    Since the early 1950’s, Singapore is internationally known as the guppy-breeding centre. At least 40 different colour varieties of guppies are cultured in Singapore, with each farm specialising in 10 to 15 varieties. These fancy varieties have been developed by skilful farmers through intensive and continual selective breeding. Genes controlling background body pigmentation such as albino (a), blond (b), gold (g) and blue (r) are autosomally inherited and recessive to their wild-type alleles which produce drab olive-brown background coloration. Colour patterns which are superimposed onto wild-type background coloration are due to genes located on the sex chromosomes. These
    sex-linked colour genes are dominant and sex-limited to males as their expression requires male hormones. Y-linked colour pattern genes carried by males are inherited only along the paternal line while X-linked genes are present in both sexes. Among the guppy varieties produced locally, only two Y-linked genes, Ssb and Sst, that control snakeskin tail and body patterns, respectively, have been found in varieties with snakeskin-like reticulations. Single colour genes that are both X- and Y-linked produce red (Rdt), blue (Blt), green (Grt), black (Bt) and variegated (Var) patterns
    on the caudal fin. The black caudal-peduncle of the Tuxedo variety is the result of Bcp, a gene that is both X- and Ylinked. Different combinations of colour pattern genes and background pigmentation genes as well as interactions among them give rise to various colour phenotypes. For
    instance, the inclusion of Bcp in Snakeskin varieties causes black reticulations on the tail fin to be replaced by large, coarse black spots. Neon coloration is produced by interactions between the Ln (light turquoise) gene with Blt, Rdt and Bcp.
    Matched MeSH terms: Pigmentation
  20. Kew, Siang-Tong
    MyJurnal
    Melanosis coli denotes brownish discoloration of the colonic mucosa found on endoscopy
    or histopathologic examination. The condition has no specific symptom on its own. It is a fairly frequent incidental finding of colonic biopsies and resection specimens. The pigmentation is caused by apoptotic cells which are ingested by macrophages and subsequently transported into the lamina propria, where lysosomes use them to produce lipofuscin pigment, not melanin as the name suggests. Melanosis coli develops in over 70% of persons who use anthraquinone laxatives (eg cascara sagrada, aloe, senna, rhubarb, and frangula), often within 4 months of use. Long-term use is generally believed to be necessary to cause melanosis coli.The condition is widely regarded as benign and reversible, and disappearance of the pigment generally occurs within a year of stopping laxatives. Although
    often due to prolonged use of anthraquinone, melanosis can probably result from other factors or exposure to other laxatives. It has been reported as a consequence of longstanding inflammatory bowel disease. Some investigators suggested that increase in apoptosis of
    colonic mucosa by anthraquinone laxatives increased the risk of colonic cancer. Recent data, including those from large-scale retrospective, prospective and experimental studies, did not show any increased cancer risk.
    Matched MeSH terms: Pigmentation
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