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1.
Medicine (Baltimore) ; 99(37): e22144, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32925769

RESUMO

The aim of this study was to determine the effectiveness of a skin stretching technique with adjustable external fixators in treating skin defects.Eighteen patients treated with a skin-stretching technique with adjustable external fixators for skin defects from April 2017 to October 2019 were included. Visual Analogue Scale (VAS) scores were collected during therapy. The skin defects gradually became smaller until they were completely resolved according to the blood flow of the affected limb and wound skin (the color, temperature, elasticity, and capillary response). The defect sizes ranged from 4 cm × 2 cm to 20 cm × 6 cm.The 18 adjustable external fixators were dismantled in 2 to 9 days (mean, 4.05 days) after the operation, and the defects were completely closed and the sutures were removed after 2 to 3 weeks. The average VAS score was 5.97. The follow-up period was 4 to 12 months (mean, 6.3 months); 17 patients healed well with linear small scar, and no infections or patients of necrosis were observed. Sensory recovery was assessed using the Medical Research Council scale, and all the sensation scores were S3+. Eight patients were healed after the first stage. Nine patients were closed totally while small sinus or skin defect were observed after sutures were removed; 3 patients were healed after the second debridement, and 6 patients finally healed after the dressings were changed. Patellar osteomyelitis recurred in 1 patient who was transferred to the Orthopedic Department for further treatment, and a flap graft procedure was performed.The operation was simple and obviously reduced the course of the disease, the costs, and the damage to the donor site, and it is also significantly superior to skin graft or flap transplantation procedures in terms of the resulting skin sensation, color, texture, elasticity, and appearance.


Assuntos
Fixadores Externos , Procedimentos Cirúrgicos Reconstrutivos/métodos , Cicatrização/fisiologia , Ferimentos e Lesões/terapia , Adulto , Idoso , Elasticidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Satisfação do Paciente , Pigmentação da Pele , Temperatura Cutânea , Fatores de Tempo
2.
Zhonghua Shao Shang Za Zhi ; 36(7): 615-619, 2020 Jul 20.
Artigo em Chinês | MEDLINE | ID: mdl-32842415

RESUMO

Hyperpigmentation and hypopigmentation are complications commonly seen in burn patients after wound healing, which may have seriously adverse impact on the appearances of the patients. The change of skin color in the exposed areas such as the face and hands may cause great psychological burden on the patients. While the occurrence and development mechanisms of hyperpigmentation and hypopigmentation post burns are unclear, it is generally believed to be associated with excess or deficiency of melanin content in the epidermis. Therefore, the therapeutic strategies of hyperpigmentation or hypopigmentation are as follows: the former focuses on inhibiting the synthesis of melanin and reducing the content of melanin in the skin, while the latter can restore the normal skin color by improving the function of melanocytes to promote the synthesis of melanin. In recent years, the therapeutic technologies for abnormal melanin metabolism after burns have developed rapidly. In this paper, treatment strategies commonly used in clinical practice are summarized in terms of photoelectric therapies, drugs, and operations, aiming to provide references for the treatment of patients who suffer abnormal pigmentation after burns.


Assuntos
Queimaduras/complicações , Hiperpigmentação , Hipopigmentação , Humanos , Hiperpigmentação/etiologia , Hipopigmentação/etiologia , Melanócitos , Pele , Pigmentação da Pele
3.
Med Sci (Paris) ; 36(8-9): 813-816, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32821057

RESUMO

The prediction of a person's aspect from analysis of an anonymous DNA sample has made significant progress in the last decade. Pigmentation (eyes, hair and, more recently, skin colour) can now be determined with good accuracy; face shape is still not amenable to prediction (except, in general lines, from ancestry). Age can apparently also be determined from methylation profiles. Police forces are, understandably, very interested in this technology, with a tendency to over-estimate its accuracy. Legislation varies greatly, with some nations opting for complete prohibition (Germany) and others allowing wide application of the approach (United Kingdom).


Assuntos
Genética Forense/tendências , Fenótipo , Adulto , Grupos Étnicos/genética , Genética Forense/métodos , Estudos de Associação Genética , Humanos , Recém-Nascido , Padrões de Herança/genética , Masculino , Polimorfismo de Nucleotídeo Único , Retratos como Assunto , Pigmentação da Pele/genética , Gêmeos/genética
4.
Am J Hum Genet ; 107(3): 473-486, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32781046

RESUMO

Africa contains more human genetic variation than any other continent, but the majority of the population-scale analyses of the African peoples have focused on just two of the four major linguistic groups, the Niger-Congo and Afro-Asiatic, leaving the Nilo-Saharan and Khoisan populations under-represented. In order to assess genetic variation and signatures of selection within a Nilo-Saharan population and between the Nilo-Saharan and Niger-Congo and Afro-Asiatic, we sequenced 50 genomes from the Nilo-Saharan Lugbara population of North-West Uganda and 250 genomes from 6 previously unsequenced Niger-Congo populations. We compared these data to data from a further 16 Eurasian and African populations including the Gumuz, another putative Nilo-Saharan population from Ethiopia. Of the 21 million variants identified in the Nilo-Saharan population, 3.57 million (17%) were not represented in dbSNP and included predicted non-synonymous mutations with possible phenotypic effects. We found greater genetic differentiation between the Nilo-Saharan Lugbara and Gumuz populations than between any two Afro-Asiatic or Niger-Congo populations. F3 tests showed that Gumuz contributed a genetic component to most Niger-Congo B populations whereas Lugabara did not. We scanned the genomes of the Lugbara for evidence of selective sweeps. We found selective sweeps at four loci (SLC24A5, SNX13, TYRP1, and UVRAG) associated with skin pigmentation, three of which already have been reported to be under selection. These selective sweeps point toward adaptations to the intense UV radiation of the Sahel.


Assuntos
Adaptação Fisiológica/genética , Variação Genética/genética , Seleção Genética/genética , Pigmentação da Pele/genética , Grupo com Ancestrais do Continente Africano/genética , Antiporters/genética , Gerenciamento de Dados , Etiópia/epidemiologia , Feminino , Genética Populacional , Genoma Humano/genética , Haplótipos/genética , Humanos , Masculino , Glicoproteínas de Membrana/genética , Oxirredutases/genética , Polimorfismo de Nucleotídeo Único/genética , Nexinas de Classificação/genética , Proteínas Supressoras de Tumor/genética , Uganda/epidemiologia
5.
Cutis ; 105(6): 319-320, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32716995
6.
PLoS One ; 15(7): e0235438, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32706822

RESUMO

Are darker-skinned workers discriminated against in the labor market? Studies using survey data have shown that darker skin tone is associated with increased labor market disadvantages. However, it is hard to refute the possibility that other factors correlated with skin tones might affect employment outcomes. To overcome this inherent limitation, we use a natural experiment: we utilize changes in one's own skin tone, generated by exposure to the sun, to explore the effect of skin tone on the tendency to be employed. We find that those people whose skin tone becomes darker by exposure to the sun (but not others) are less likely to be employed when the UV radiation in the previous three weeks in the area in which they reside is greater. These within-person findings hold even when controlling for the week, the year, the region, demographic characteristics and the occupation and industry one is employed in.


Assuntos
Emprego/ética , Racismo/ética , Pigmentação da Pele , Discriminação Social/ética , Adulto , Emprego/psicologia , Feminino , Humanos , Masculino , Racismo/psicologia , Discriminação Social/psicologia , Inquéritos e Questionários , Raios Ultravioleta
7.
Proc Natl Acad Sci U S A ; 117(31): 18574-18581, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32661155

RESUMO

Many vertebrates have distinctive blue-green bones and other tissues due to unusually high biliverdin concentrations-a phenomenon called chlorosis. Despite its prevalence, the biochemical basis, biology, and evolution of chlorosis are poorly understood. In this study, we show that the occurrence of high biliverdin in anurans (frogs and toads) has evolved multiple times during their evolutionary history, and relies on the same mechanism-the presence of a class of serpin family proteins that bind biliverdin. Using a diverse combination of techniques, we purified these serpins from several species of nonmodel treefrogs and developed a pipeline that allowed us to assemble their complete amino acid and nucleotide sequences. The described proteins, hereafter named biliverdin-binding serpins (BBS), have absorption spectra that mimic those of phytochromes and bacteriophytochromes. Our models showed that physiological concentration of BBSs fine-tune the color of the animals, providing the physiological basis for crypsis in green foliage even under near-infrared light. Additionally, we found that these BBSs are most similar to human glycoprotein alpha-1-antitrypsin, but with a remarkable functional diversification. Our results present molecular and functional evidence of recurrent evolution of chlorosis, describe a biliverdin-binding protein in vertebrates, and introduce a function for a member of the serpin superfamily, the largest and most ubiquitous group of protease inhibitors.


Assuntos
Anuros/fisiologia , Biliverdina/metabolismo , Serpinas/metabolismo , Pigmentação da Pele/fisiologia , Animais , Anuros/classificação , Anuros/genética , Biliverdina/química , Mimetismo Biológico/fisiologia , Serpinas/química , Serpinas/genética , Pigmentação da Pele/genética
9.
PLoS One ; 15(6): e0233277, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32479503

RESUMO

This paper reports the results of an experiment involving text-messaging and emojis in laboratory trust games executed on mobile devices. Decomposing chat logs, I find that trust increases dramatically with the introduction of emojis to one-shot games, while reciprocation increases only modestly. Skin tones embedded in emojis impact sharing and resulting gains-to the benefit of some and detriment to others. Both light and dark skin players trust less on receipt of a dark skin tone emoji-suggestive of statistical discrimination. In this way, computer-mediated communication leads to reduced gains for dark-skinned persons. These results highlight the complex social judgment that motivates trust in an anonymous counterpart.


Assuntos
Racismo/psicologia , Envio de Mensagens de Texto/ética , Confiança/psicologia , Adulto , Telefone Celular , Feminino , Jogos Experimentais , Humanos , Relações Interpessoais , Julgamento/ética , Julgamento/fisiologia , Linguística/métodos , Masculino , Pigmentação da Pele , Adulto Jovem
10.
Nat Commun ; 11(1): 2988, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32532976

RESUMO

Tissue homeostasis requires regulation of cell-cell communication, which relies on signaling molecules and cell contacts. In skin epidermis, keratinocytes secrete factors transduced by melanocytes into signaling cues promoting their pigmentation and dendrite outgrowth, while melanocytes transfer melanin pigments to keratinocytes to convey skin photoprotection. How epidermal cells integrate these functions remains poorly characterized. Here, we show that caveolae are asymmetrically distributed in melanocytes and particularly abundant at the melanocyte-keratinocyte interface in epidermis. Caveolae in melanocytes are modulated by ultraviolet radiations and keratinocytes-released factors, like miRNAs. Preventing caveolae formation in melanocytes increases melanin pigment synthesis through upregulation of cAMP signaling and decreases cell protrusions, cell-cell contacts, pigment transfer and epidermis pigmentation. Altogether, we identify that caveolae serve as molecular hubs that couple signaling outputs from keratinocytes to mechanical plasticity of pigment cells. The coordination of intercellular communication and contacts by caveolae is thus crucial to skin pigmentation and tissue homeostasis.


Assuntos
Cavéolas/metabolismo , Queratinócitos/metabolismo , Melanócitos/metabolismo , Pigmentação da Pele/fisiologia , Pele/metabolismo , Caveolina 1/metabolismo , Comunicação Celular/fisiologia , Comunicação Celular/efeitos da radiação , Células Cultivadas , Técnicas de Cocultura , Células Epidérmicas/metabolismo , Epiderme/metabolismo , Epiderme/ultraestrutura , Células HeLa , Humanos , Queratinócitos/citologia , Melanócitos/citologia , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Transdução de Sinais/fisiologia , Transdução de Sinais/efeitos da radiação , Pele/citologia , Pele/ultraestrutura , Raios Ultravioleta
12.
Nat Commun ; 11(1): 2414, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415098

RESUMO

Plumage is among the most well-studied components of integumentary colouration. However, plumage conceals most skin in birds, and as a result the presence, evolution and function of skin colour remains unexplored. Here we show, using a database of 2259 species encompassing >99% of bird genera, that melanin-rich, black skin is found in a small but sizeable percentage (~5%) of birds, and that it evolved over 100 times. The spatial distribution of black skin follows Gloger's rule, which states that pigmentation of endothermic animals increases towards the equator. Furthermore, most black-skinned birds inhabit high irradiation regions, and tend to be bald and/or have white feathers. Thus, taken together, our results suggest that melanin-rich, black skin helps to protect birds against ultraviolet irradiation. More generally, our results illustrate that feathered skin colour varies taxonomically, ontogenetically and temporally, providing an additional dimension for avian colour research.


Assuntos
Plumas/fisiologia , Pigmentação da Pele/efeitos da radiação , Pele/efeitos da radiação , Raios Ultravioleta , Animais , Evolução Biológica , Aves , Bases de Dados Factuais , Feminino , Geografia , Masculino , Melaninas/biossíntese , Filogenia , Especificidade da Espécie
13.
PLoS One ; 15(5): e0233221, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32433700

RESUMO

Conspicuous coloration is an important subject in social communication and animal behavior, and it can provide valuable insight into the role of visual signals in social selection. However, animal coloration can be plastic and affected by abiotic factors such as temperature, making its quantification problematic. In such cases, careful consideration is required so that metric choices are consistent across environments and least sensitive to abiotic factors. A detailed assessment of plastic trait in response to environmental conditions could help identify more robust methods for quantifying color. Temperature affects sexual ornamentation of eastern fence lizards, Sceloporus undulatus, with ventral coloration shifting from green to blue hues as temperatures rise, making the calculation of saturation (color purity) difficult under conditions where temperatures vary. We aimed to characterize how abiotic factors influence phenotypic expression and to identify a metric for quantifying animal color that is either independent from temperature (ideally) or best conserves individual's ranks. We compared the rates of change in saturation across two temperature treatments using seven metrics: three that are based on fixed spectral ranges (with two of them designed by us specifically for this system) and three that track the expressed hue (with one of them designed by us to circumvent spurious results in unornamented individuals). We also applied a lizard visual sensitivity model to understand how temperature-induced color changes may be perceived by conspecifics. We show that the rate of change in saturation between two temperatures is inconsistent across individuals, increasing at a higher rate in individuals with higher baseline saturation at lower temperatures. In addition, the relative color rank of individuals in a population varies with the temperature standardized by the investigator, but more so for some metrics than others. While we were unable to completely eliminate the effect of temperature, current tools for quantifying color allowed us to use spectral data to estimate saturation in a variety of ways and to largely preserve saturation ranks of individuals across temperatures while avoiding erroneous color scores. We describe our approaches and suggest best-practices for quantifying and interpreting color, particularly in cases where color changes in response to environmental factors.


Assuntos
Lagartos/fisiologia , Animais , Cor , Meio Ambiente , Feminino , Genitália/anatomia & histologia , Genitália/fisiologia , Lagartos/anatomia & histologia , Masculino , Caracteres Sexuais , Pigmentação da Pele/fisiologia , Temperatura
14.
PLoS One ; 15(5): e0232900, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413090

RESUMO

Congenital deafness in the domestic dog is usually related to the presence of white pigmentation, which is controlled primarily by the piebald locus on chromosome 20 and also by merle on chromosome 10. Pigment-associated deafness is also seen in other species, including cats, mice, sheep, alpacas, horses, cows, pigs, and humans, but the genetic factors determining why some piebald or merle dogs develop deafness while others do not have yet to be determined. Here we perform a genome-wide association study (GWAS) to identify regions of the canine genome significantly associated with deafness in three dog breeds carrying piebald: Dalmatian, Australian cattle dog, and English setter. We include bilaterally deaf, unilaterally deaf, and matched control dogs from the same litter, phenotyped using the brainstem auditory evoked response (BAER) hearing test. Principal component analysis showed that we have different distributions of cases and controls in genetically distinct Dalmatian populations, therefore GWAS was performed separately for North American and UK samples. We identified one genome-wide significant association and 14 suggestive (chromosome-wide) associations using the GWAS design of bilaterally deaf vs. control Australian cattle dogs. However, these associations were not located on the same chromosome as the piebald locus, indicating the complexity of the genetics underlying this disease in the domestic dog. Because of this apparent complex genetic architecture, larger sample sizes may be needed to detect the genetic loci modulating risk in piebald dogs.


Assuntos
Surdez/veterinária , Doenças do Cão/genética , Animais , Estudos de Casos e Controles , Surdez/congênito , Surdez/genética , Cães , Potenciais Evocados Auditivos , Loci Gênicos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Testes Auditivos , Polimorfismo de Nucleotídeo Único , Seleção Artificial , Pigmentação da Pele/genética
15.
Proc Natl Acad Sci U S A ; 117(23): 12885-12890, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32457164

RESUMO

Camouflage patterns prevent detection and/or recognition by matching the background, disrupting edges, or mimicking particular background features. In variable habitats, however, a single pattern cannot match all available sites all of the time, and efficacy may therefore be reduced. Active color change provides an alternative where coloration can be altered to match local conditions, but again efficacy may be limited by the speed of change and range of patterns available. Transparency, on the other hand, creates high-fidelity camouflage that changes instantaneously to match any substrate but is potentially compromised in terrestrial environments where image distortion may be more obvious than in water. Glass frogs are one example of terrestrial transparency and are well known for their transparent ventral skin through which their bones, intestines, and beating hearts can be seen. However, sparse dorsal pigmentation means that these frogs are better described as translucent. To investigate whether this imperfect transparency acts as camouflage, we used in situ behavioral trials, visual modeling, and laboratory psychophysics. We found that the perceived luminance of the frogs changed depending on the immediate background, lowering detectability and increasing survival when compared to opaque frogs. Moreover, this change was greatest for the legs, which surround the body at rest and create a diffuse transition from background to frog luminance rather than a sharp, highly salient edge. This passive change in luminance, without significant modification of hue, suggests a camouflage strategy, "edge diffusion," distinct from both transparency and active color change.


Assuntos
Adaptação Biológica/fisiologia , Anuros/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Pigmentação da Pele/fisiologia , Animais , Cor , Simulação por Computador , Ecossistema , Furões/fisiologia , Humanos , Modelos Biológicos , Comportamento Predatório/fisiologia
17.
Life Sci ; 250: 117602, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32240677

RESUMO

AIMS: Extrinsic ageing or photoageing relates to the onset of age-linked phenotypes such as skin hyperpigmentation due to UV exposure. UV induced upregulated production of tyrosinase enzyme, which catalyses the vital biochemical reactions of melanin synthesis is responsible for the inception of skin hyperpigmentation. We aimed to generate a validated QSAR model with a dataset consisting of 69 thio-semicarbazone derivatives to elucidate the physicochemical properties of compounds essential for tyrosinase inhibition and to identify novel lead molecules with enhanced tyrosinase inhibitory activity and bioavailability. MAIN METHODS: Lead optimization and insilico approaches were employed in this research work. QSAR model was generated and validated by exploiting Multiple Linear Regression method. Prioritization of lead-like compounds was accomplished by performing multi parameter optimization depleting molecular docking, bioavailability assessments and toxicity prediction for 69 compounds Derivatives of best lead compound were retrieved from chemical spaces. KEY FINDINGS: Molecular descriptors explicated the significance of chemical properties essential for chelation of copper ions present in the active site of tyrosinase protein target. Further, derivatives which comprise of electron donating groups in their chemical structure were predicted and analysed for tyrosinase inhibitory activity by employing insilico methodologies including chemical space exploration. SIGNIFICANCE: Our research work resulted in the generation of a validated QSAR model with higher degree of external predictive ability and significance to tyrosinase inhibitory activity. We propose 11 novel derivative compounds with enhanced tyrosinase inhibitory activity and bioavailability.


Assuntos
Química Farmacêutica/métodos , Biologia Computacional/métodos , Indóis/antagonistas & inibidores , Monofenol Mono-Oxigenase/antagonistas & inibidores , Pele/efeitos dos fármacos , Agaricales/metabolismo , Domínio Catalítico , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Elétrons , Inibidores Enzimáticos/farmacologia , Humanos , Ligação de Hidrogênio , Ligantes , Simulação de Acoplamento Molecular , Estrutura Molecular , Monofenol Mono-Oxigenase/metabolismo , Relação Quantitativa Estrutura-Atividade , Pigmentação da Pele/efeitos dos fármacos , Tiossemicarbazonas/química , Raios Ultravioleta
18.
Hist Philos Life Sci ; 42(2): 16, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32347394

RESUMO

Although much attention has already been paid to Kant's ideas on race, more research is needed to determine the sources that he used to support his portrayal of non-white races. A comprehension of the intellectual context gives us the opportunity to see the way in which Kant wished to contribute to discussions on inheritable human characteristics and the inferiority of certain races. This article will emphasize the relevance of the views of Joseph Priestley and Alexander Wilson for Kant's hypothesis on the relation between phlogiston and the black race. This allows us to comprehend the methodology that Kant prescribed for natural history and its consequences for his understanding of the inferiority of the black race.


Assuntos
Racismo/história , Pigmentação da Pele , História do Século XVIII , Humanos
20.
Artigo em Inglês | MEDLINE | ID: mdl-32121219

RESUMO

Ultraviolet radiation (UVR) is a ubiquitous exposure which may contribute to decreased folate levels. Skin pigmentation mediates the biological effect of UVR exposure, but its relationship to folate levels is unexamined. Interactions may exist between UVR and pigmentation genes in determining folate status, which may, in turn, impact homocysteine levels, a potential risk factor for multiple chronic diseases. Therefore, independent and interactive influences of environmental UVR and genetic variants related to skin pigmentation (MC1R-rs1805007, IRF4-rs12203592 and HERC2-rs12913832) on folate (red blood cell (RBC) and serum) and homocysteine levels were examined in an elderly Australian cohort (n = 599). Genotypes were assessed by RT/RFLP-PCR, and UVR exposures were assessed as the accumulated erythemal dose rate accumulated over 4 months (4M-EDR). Multivariate analysis found significant negative associations between 4M-EDR and RBC folate (p < 0.001, ß = -0.19), serum folate (p = 0.045, ß = -0.08) and homocysteine levels (p < 0.001, ß = -0.28). Significant associations between MC1R-rs1805007 and serum folate levels (p = 0.020), and IRF4-rs12203592 and homocysteine levels (p = 0.026) occurred but did not remain significant following corrections with confounders. No interactions between 4M-EDR and pigmentation variants in predicting folate/homocysteine levels were found. UVR levels and skin pigmentation-related variants are potential determinants of folate and homocysteine status, although, associations are mixed and complex, with further studies warranted.


Assuntos
Ácido Fólico/sangue , Homocisteína/sangue , Pigmentação da Pele/genética , Pele/efeitos da radiação , Raios Ultravioleta , Idoso , Austrália , Feminino , Genótipo , Humanos , Masculino
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