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1.
Langmuir ; 37(19): 5943-5949, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-33951393

RESUMO

Understanding the evolution of the defects in surface patterns is of practical importance to improve the performance and structural durability of the pattern-based micro- and nanodevices. In this work, we investigate the effects of temperature, compressive strain, and relative direction of the compression to the prestretch on the slip motion of ripple dislocations formed on the surface of gold-coated poly(dimethylsiloxane) films. Applying compression in the direction parallel to the direction of prestretch cannot cause the slip motion of the ripple dislocations. The initial velocity of the slip motion of the ripple dislocations increases with the increases in temperature and compressive strain. The temperature dependence of the ratios of the configuration force to the viscous coefficient and the viscous coefficient to the effective mass of the ripple dislocations follows the Arrhenius equation.

2.
Zhonghua Shao Shang Za Zhi ; 36(4): 267-272, 2020 Apr 20.
Artigo em Chinês | MEDLINE | ID: mdl-32340416

RESUMO

Objective: To explore the clinical effect of nebulized acetylcysteine inhalation combined with bronchoscopy in treating elderly patients with severe ventilator-associated pneumonia (VAP). Methods: From January 2016 to December 2017, 80 elderly patients with severe VAP who were hospitalized in Zhejiang Hospital were divided into acetylcysteine+ bronchoscopy group [24 males and 16 females, aged (78±7) years] and bronchoscopy group [26 males and 14 females, aged (80±7) years]using random number table for a prospective cohort study. Patients in bronchoscopy group were treated with bronchoscopy in addition to conventional supportive care of symptoms. Patients in acetylcysteine+ bronchoscopy group received nebulized acetylcysteine inhalation therapy on the basis of the treatment given to patients in bronchoscopy group. Patients in both groups received treatment continuously for 7 days. The simplified clinical pulmonary infection score (CPIS) in both groups was assessed before and after treatment. Venous blood of 10 mL was collected before and after treatment to detect leukocyte count, serum C-reactive protein, and procalcitonin. Arterial blood of 1 mL was collected before and after treatment to detect partial arterial oxygen pressure (PaO(2)), partial arterial carbon dioxide pressure (PaCO(2)), oxygenation index. The inhalation platform pressure (Pplat), dynamic lung compliance (Cdyn), airway resistance, work of breathing, time of antibiotic use, and time of mechanical ventilation of patients in two groups were recorded before and after treatment. Data were statistically analyzed with chi-square test and t test. Results: (1) The simplified CPIS, leukocyte count, serum C-reactive protein, and procalcitonin of patients in acetylcysteine+ bronchoscopy group were significantly lower than those in bronchoscopy group after treatment (t=2.32, 2.15, 6.08, 7.12, P<0.05 or P<0.01). The simplified CPIS, leukocyte count, serum C-reactive protein, and procalcitonin of patients in acetylcysteine+ bronchoscopy group and bronchoscopy group after treatment were significantly lower than those before treatment (t=13.76, 13.60, 12.70, 8.32, 11.44, 14.28, 9.48, 9.50, P<0.01). (2) Compared with bronchoscopy group, patients in acetylcysteine+ bronchoscopy group had significantly higher PaO(2) and oxygenation index (t=4.14, 2.55, P<0.05 or P<0.01) but significantly lower PaCO(2) (t=4.36, P<0.01) after treatment. The PaO(2) and oxygenation index of patients in acetylcysteine+ bronchoscopy group after treatment were significantly higher than those before treatment (t=10.90, 43.72, P<0.01). The PaO(2) and oxygenation index of patients in bronchoscopy group after treatment were also significantly higher than those before treatment (t=6.55, 43.03, P<0.01). The PaCO(2) of patients in both groups after treatment were significantly lower than those before treatment (t=21.54, 21.92, P<0.01). (3) The Cdyn of patients in acetylcysteine+ bronchoscopy group after treatment was significantly higher than that in bronchoscopy group (t=5.41, P<0.01), and Pplat, airway resistance, and work of breathing were significantly lower than those in bronchoscopy group (t=2.18, 5.46, 2.49, P<0.05 or P<0.01). The Cdyn of patients in both groups after treatment were significantly higher than those before treatment (t=16.10, 10.90, P<0.01), and Pplat, airway resistance, and work of breathing were significantly lower than those before treatment (t=21.18, 11.13, 9.32, 15.50, 5.17, 5.97, P<0.01). (4)The time of mechanical ventilation and antibiotic usage of patients in acetylcysteine+ bronchoscopy group were (6.9±1.9)and (8.7±2.8) d, respectively, which were significantly shorter than (10.1±2.2) and (11.6±3.5) d in bronchoscopy group (t=6.85, 4.09, P<0.01). Conclusions: Nebulized acetylcysteine inhalation combined with bronchoscopy can significantly control the degree of lung infection in elderly patients with severe VAP, improve patients' respiratory mechanics parameter and blood gas analysis indicator, and shorten the time for mechanical ventilation and antibiotic usage.


Assuntos
Pneumonia Associada à Ventilação Mecânica , Acetilcisteína , Idoso , Idoso de 80 Anos ou mais , Broncoscopia , Feminino , Humanos , Masculino , Estudos Prospectivos , Respiração Artificial
3.
Int J Cosmet Sci ; 41(6): 534-547, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31309600

RESUMO

OBJECTIVE: To demonstrate the in vitro activities of panthenol, palmitoylethanolamide (PEA), and niacinamide (NAM) and determine the biophysical properties, clinical safety, tolerability together with efficacy of two developmental anti-redness (AR) formulations containing these ingredients, in alleviating facial redness associated with winter xerosis in healthy volunteers with sensitive skin. METHODS: The anti-inflammatory and skin protective properties of panthenol, PEA and NAM were evaluated in vitro. The physical properties of the AR formulations were analysed using measurement of water vapour transport rate (WVTR) and infrared spectroscopy. Clinical studies were performed between the months of December and April (2014-2015) with efficacy assessed during the winter. Facial redness, irritation, sensitization potential, photo-irritation, and photo-sensitization were evaluated. Self-assessed adverse reactions were reported in diaries of use. RESULTS: Panthenol and PEA reduced prostaglandin E2 , interleukin-6, and thymic stromal lymphopoietin levels in vitro, while NAM induced nicotinamide adenine dinucleotide (NAD) levels and the keratinocyte differentiation markers: filaggrin (2-fold increase, P < 0.001), loricrin (2-fold increase, P < 0.05), involucrin (2 fold increase, P < 0.001) & peroxisomal proliferator activated receptor-alpha (1.5 fold increase, P < 0.05). The two AR products exhibited low WVTR vs. no treatment (P < 0.001) and displayed an ordered lipid structure. The day cream formulation protected against ultraviolet B radiation in vitro. A total of 382 participants were included in clinical studies which showed the AR formulations significantly improved facial redness associated with winter xerosis (Day 29 mean change from baseline: AR day cream 0.77 (P < 0.001); AR serum 0.67 (P < 0.001)). No irritation, sensitization, photo-irritation, photo-sensitization or product-related adverse reactions were observed or reported in the clinical studies. CONCLUSION: The new products significantly improved skin redness associated with winter xerosis in participants with self-perceived sensitive skin. Both products were well tolerated with a suitable safety profile for topical use in subjects with sensitive skin.


OBJECTIF: Démontrer l'activité in vitro du panthénol, du palmitoyléthanolamide (PEA), et du nicotinamide (NAM) et déterminer les propriétés biophysiques, la sécurité clinique, la tolérance ainsi que l'efficacité de deux formulations anti-rougeurs (AR) en développement contenant ces ingrédients pour atténuer les rougeurs faciales associées à la xérose hivernale chez des volontaires sains présentant une peau sensible. MÉTHODES: Les propriétés anti-inflammatoires et protectrices du panthénol, du PEA et du NAM ont été évaluées in vitro. Les propriétés physiques des formulations AR ont été analysées en mesurant le taux de transport de vapeur d'eau (WVTR) et par spectroscopie infrarouge. Des études cliniques ont été réalisées entre décembre et avril (2014-2015) et l'efficacité a été évaluée pendant l'hiver. Les rougeurs, l'irritation, le potentiel de sensibilisation, la photo-irritation et la photosensibilisation au niveau du visage ont été évalués. Des effets indésirables auto-évalués ont été signalés dans des journaux d'utilisation. RÉSULTATS: Le panthénol et le PEA ont réduit les niveaux de prostaglandine E2 , d'interleukine-6 et de lymphopoiétine stromale thymique in vitro, tandis que le NAM a généré une augmentation des taux de nicotinamide adénine dinucléotide (NAD) et des marqueurs de différenciation kératinocytaire : filaggrine (multiplication des taux par 2, P < 0,001), loricrine (multiplication des taux par 2, P < 0,05), involucrine (multiplication des taux par 2, P < 0,001) et du récepteur alpha activé de la prolifération peroxysomale (multiplication des taux par 1,5, P < 0,05). Les deux produits antirétroviraux présentaient un faible taux de WVTR par rapport à l'absence de traitement (P < 0,001) et présentaient une structure lipidique ordonnée. La formulation de la crème de jour protège contre le rayonnement ultraviolet B in vitro. Un total de 382 participants ont été inclus dans les études cliniques qui ont montré que les formulations AR amélioraient significativement les rougeurs faciales associées à la xérose hivernale (changement moyen du jour 29 par rapport à la référence : crème de jour AR 0,77 (P < 0,001) ; sérum AR 0,67 (P < 0,001)). Aucune irritation, sensibilisation, photo-irritation, photosensibilisation ni effet indésirable lié au produit n'a été observé ou signalé dans les études cliniques. CONCLUSION: Les nouveaux produits ont considérablement amélioré la rougeur de la peau associée à la xérose hivernale chez les participants présentant une peau sensible auto-perçue. Les deux produits ont été bien tolérés avec un profil de sécurité approprié pour un usage topique chez les sujets présentant une peau sensible.


Assuntos
Cosméticos , Etanolaminas/administração & dosagem , Niacinamida/administração & dosagem , Ácidos Palmíticos/administração & dosagem , Ácido Pantotênico/análogos & derivados , Pele/fisiopatologia , Administração Tópica , Amidas , Proteínas Filagrinas , Humanos , Técnicas In Vitro , Ácido Pantotênico/administração & dosagem , Estações do Ano , Pele/efeitos dos fármacos
4.
Opt Lett ; 44(3): 667-670, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30702706

RESUMO

The photonic nanojet is a highly concentrated beam with low divergence on the shadow side of dielectric microparticles. In this Letter, we first theoretically and experimentally investigate the formation of high-quality photonic nanojets by decorating spider silk. The dragline silks are directly extracted from cellar spiders and capable of efficiently collecting ultraviolet cure adhesive. The liquid-collecting capacity of the captured silk is the result of a singular fiber structure with periodic spindle knots. Using a scanning-optical-microscope system, we show that high-quality photonic nanojets are generated by silk fiber with spindle knots. With the variation in spindle-knot dimensions, the properties of photonic nanojets, such as intensity distribution, focal length, and full width at half-maximum, are able to tune flexibly. By combining the unique biocompatibility, flexibility, and tensile strength, the silk filaments with spindle knots pave a potential way for original bio-photonic applications.


Assuntos
Fótons , Seda , Aranhas , Animais , Fotografação
5.
Braz J Med Biol Res ; 49(1): e4769, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26628393

RESUMO

We investigated the diagnostic value of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of magnetic resonance diffusion tensor imaging (DTI) in patients with spinal cord compression (SCC) using a meta-analysis framework. Multiple scientific literature databases were exhaustively searched to identify articles relevant to this study. Mean values and standardized mean differences (SMDs) were calculated for the ADC and FA in normal and diseased tissues. The STATA version 12.0 software was used for statistical analysis. Of the 41 articles initially retrieved through database searches, 11 case-control studies were eligible for the meta-analysis and contained a combined total of 645 human subjects (394 patients with SCC and 251 healthy controls). All 11 studies reported data on FA, and 9 contained data related to the ADC. The combined SMDs of the ADC and FA showed that the ADC was significantly higher and the FA was lower in patients with SCC than in healthy controls. Subgroup analysis based on the b value showed higher ADCs in patients with SCC than in healthy controls at b values of both ≤500 and >500 s/mm2. In summary, the main findings of this meta-analysis revealed an increased ADC and decreased FA in patients with SCC, indicating that DTI is an important diagnostic imaging tool to assess patients suspected to have SCC.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Compressão da Medula Espinal/diagnóstico , Anisotropia , Estudos de Casos e Controles , Confiabilidade dos Dados , Diagnóstico Precoce , Humanos , Viés de Publicação
6.
Braz. j. med. biol. res ; 49(1): e4769, 2016. graf
Artigo em Inglês | LILACS | ID: biblio-951641

RESUMO

We investigated the diagnostic value of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of magnetic resonance diffusion tensor imaging (DTI) in patients with spinal cord compression (SCC) using a meta-analysis framework. Multiple scientific literature databases were exhaustively searched to identify articles relevant to this study. Mean values and standardized mean differences (SMDs) were calculated for the ADC and FA in normal and diseased tissues. The STATA version 12.0 software was used for statistical analysis. Of the 41 articles initially retrieved through database searches, 11 case-control studies were eligible for the meta-analysis and contained a combined total of 645 human subjects (394 patients with SCC and 251 healthy controls). All 11 studies reported data on FA, and 9 contained data related to the ADC. The combined SMDs of the ADC and FA showed that the ADC was significantly higher and the FA was lower in patients with SCC than in healthy controls. Subgroup analysis based on the b value showed higher ADCs in patients with SCC than in healthy controls at b values of both ≤500 and >500 s/mm2. In summary, the main findings of this meta-analysis revealed an increased ADC and decreased FA in patients with SCC, indicating that DTI is an important diagnostic imaging tool to assess patients suspected to have SCC.


Assuntos
Humanos , Compressão da Medula Espinal/diagnóstico , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Estudos de Casos e Controles , Anisotropia , Viés de Publicação , Diagnóstico Precoce , Confiabilidade dos Dados
7.
J Dermatol Sci ; 70(3): 159-65, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23587732

RESUMO

BACKGROUND: While skin color is the most notable difference among ethnic skins the current knowledge on skin physiological and aging properties are based mainly on Caucasian skin studies. OBJECTIVE: To evaluate histological differences in elastin fiber network and differential responsiveness to TGF-ß in skin of Caucasians and African Americans. METHODS: These studies were undertaken using human skin biopsies, primary dermal fibroblasts, Western blot analyses, immunofluorescence microscopy, cDNA array and quantitative real-time PCR. RESULTS: In Caucasian subjects, tropoelastin expression and elastin fibers in photoprotected skin was substantially less than in age-matched African American skin. Expression of tropoelastin in photoexposed skin of African American was similar to their photoprotected skin, suggesting that photoexposure did not affect elastin fibers in African American skin to the same extent as Caucasian skin. An elevated level of TGF-ß1 present in media from dermal fibroblasts derived from African American skins correlated well with the higher levels of TGF-ß mRNA in African American skins analyzed by cDNA array. Treatment with TGF-ß1 resulted in a considerably higher induction of elastin mRNA in dermal fibroblasts from African Americans than from Caucasian fibroblasts, indicative of enhanced TGF-ß signaling in African American skins. Furthermore, UVA exposure decreased levels of elastin mRNA in Caucasian fibroblasts compared to African Americans fibroblasts. CONCLUSION: These results suggest that there are ethnic differences in the elastin fiber network and in TGF-ß signaling in African American and Caucasian skin, and that African American have less UV dependent loss of elastin than Caucasian which may contribute to the different perceived aging phenotypes.


Assuntos
Negro ou Afro-Americano , Elastina/metabolismo , Fibroblastos/metabolismo , Pele/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , População Branca , Adulto , Negro ou Afro-Americano/genética , Biópsia , Células Cultivadas , Elastina/genética , Feminino , Fibroblastos/efeitos da radiação , Regulação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Serina-Treonina Quinases/metabolismo , RNA Mensageiro/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Pele/efeitos da radiação , Envelhecimento da Pele/etnologia , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta2/metabolismo , Fator de Crescimento Transformador beta3/metabolismo , Tropoelastina/metabolismo , Raios Ultravioleta , População Branca/genética
8.
Int J Tuberc Lung Dis ; 17(3): 354-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23228433

RESUMO

We assessed the association between diabetes mellitus and drug-resistant tuberculosis (TB). Among new patients, diabetes was significantly associated with any resistance to isoniazid excluding multidrug-resistant TB (MDR-TB; adjusted OR [aOR] 1.88, 95%CI 1.07-3.31), but not with MDR-TB (aOR 0.95, 95%CI 0.34-2.68). Among previously treated patients, diabetes was also significantly associated with INH resistance (aOR 6.76, 95%CI 1.53-29.98) but not with MDR-TB (aOR 1.52, 95%CI 0.59-3.95). We concluded that diabetes was associated with INH resistance and speculated that the sample size of retreatment cases was insufficient to confirm the association between diabetes and MDR-TB.


Assuntos
Antituberculosos/uso terapêutico , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Isoniazida/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Pulmonar/epidemiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos Transversais , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Humanos , Lactente , Recém-Nascido , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Medição de Risco , Fatores de Risco , Taiwan/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Adulto Jovem
9.
Int J Cosmet Sci ; 33(1): 62-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20704601

RESUMO

Dermal elastic fibres are extracellular matrix protein complexes produced by fibroblasts and involved in skin elasticity. Elastin fibres decrease with age as a result of reduced synthesis and increased degradation, resulting in skin sagging and reduced skin elasticity. In this study, we show that retinol (ROL), known to enhance dermal collagen production, is also enhancing elastin fibre formation. ROL induced elastin gene expression and elastin fibre formation in cultured human dermal fibroblasts. Topical treatment of cultured human skin explants with a low dose (0.04%) of ROL increased mRNA and protein levels of tropoelastin and of fibrillin-1, an elastin accessory protein, as documented by QPCR and immunohistochemistry staining. Luna staining confirmed the increased elastin fibre network in the ROL-treated skin explants, as compared with untreated controls. These data demonstrate that ROL exerts its anti-ageing benefits not only via enhanced epidermal proliferation and increased collagen production, but also through an increase in elastin production and assembly.


Assuntos
Envelhecimento/metabolismo , Elastina/biossíntese , Pele/efeitos dos fármacos , Vitamina A/farmacologia , Adulto , Células Cultivadas , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Humanos , Reação em Cadeia da Polimerase , Pele/metabolismo
10.
Int J Tuberc Lung Dis ; 14(7): 924-6, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20550780

RESUMO

Taiwan initiated a multidrug-resistant tuberculosis (MDR-TB) programme in May 2007. Seventy-seven MDR-TB patients were enrolled from May 2007 to February 2009 in Eastern Taiwan. Isolates of 73 (94%) patients were available for genotyping using spoligotyping and MIRU-VNTR (mycobacterial interspersed repetitive unit-variable number of tandem repeats). Spoligotyping results indicated the Beijing strain as the predominant genotype (n = 48, 66%). Of the 73 isolates, 28 (38.4%) had a unique pattern and 45 (61.6%) were clustered pattern strains. Epidemiological links could be established in 21 (46.7%) of the 45 patients with a clustered pattern strain. The proportion of MDR-TB patients with a clustered pattern strain in Eastern Taiwan was high.


Assuntos
Epidemiologia Molecular/métodos , Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/genética , Adulto , Idoso , Técnicas de Tipagem Bacteriana/métodos , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Taiwan/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/transmissão , Adulto Jovem
13.
Int J Tuberc Lung Dis ; 7(6): 569-74, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12797700

RESUMO

SETTING: The utilisation of new, rapid methods of diagnosis of tuberculosis is currently of great interest for tuberculosis control. This study was carried out in a teaching hospital in the eastern region of Taiwan. OBJECTIVE: The BACTEC MGIT 960 system was evaluated and compared with Lowenstein-Jensen (LJ) medium and Middlebrook 7H11 plate for recovery rate and time to detection of mycobacteria. DESIGN: A total of 1396 sputum samples were tested for the presence of mycobacteria. Specimens were processed and inoculated separately in the BACTEC MGIT 960 system, on LJ medium and 7H11 for comparative study. RESULTS: The BACTEC MGIT 960 detected 235 isolates (100%), followed by LJ with 205 isolates (87.2%) and 7H11 with 178 isolates (75.7%). The mean time to detection of Mycobacterium tuberculosis complex was 11.6 days with MGIT 960, 20.1 days with LJ, and 18.7 days with 7H11. The contamination rates were 15.1% with MGIT 960, 10.1% with LJ and 9.7% with 7H11. CONCLUSION: The BACTEC MGIT 960 system is a sensitive, rapid mycobacterial culturing system. However, the high contamination rate is a concern that should be carefully evaluated in the clinical setting.


Assuntos
Técnicas de Cultura de Células/instrumentação , Meios de Cultura , Técnicas Microbiológicas/instrumentação , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose Pulmonar/microbiologia , Contaminação de Equipamentos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Escarro/microbiologia , Fatores de Tempo
14.
J Invest Dermatol ; 119(6): 1330-40, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12485436

RESUMO

The microphthalmia-associated transcription factor is implicated in melanocyte development and in the regulation of melanogenesis. Microphthalmia-associated transcription factor is thought to bind to the M-box promoter elements of tyrosinase, tyrosinase-related protein-1 and dopachrome tautomerase/tyrosinase-related protein-2 and transactivate these genes, resulting in increased pigmentation. Using a luciferase reporter construct driven by the microphthalmia-associated transcription factor promoter, we identified agents that modulate microphthalmia-associated transcription factor promoter activity. Changes in endogenous microphthalmia-associated transcription factor expression levels upon treatment with these agents were confirmed using northern and western blots, and their pigmentary modulating activities were demonstrated. Ultraviolet B irradiation and traditional Chinese medicine-1, a natural extract used in traditional Chinese medicine, upregulated microphthalmia-associated transcription factor gene expression and enhanced tyrosinase activity in vitro. Dihydrolipoic acid, lipoic acid, and resveratrol reduced microphthalmia-associated transcription factor and tyrosinase promoter activities. These agents also inhibited the forskolin- and ultraviolet B-stimulated promoter activities of these genes and significantly reduced tyrosinase activity in melanocyte cultures, resulting in depigmentation. Overexpressed microphthalmia-associated transcription factor was capable of rescuing the repressive effects of these compounds on the cotransfected tyrosinase promoter. Dark-skinned Yucatan swine treated with these agents showed visible skin lightening, which was confirmed histologically, whereas ultraviolet B-induced tanning of light-skinned swine was inhibited using these agents. Our findings suggest that modulation of microphthalmia-associated transcription factor expression can alter skin pigmentation and further confirm the central role of microphthalmia-associated transcription factor in melanogenesis.


Assuntos
Proteínas de Ligação a DNA/genética , Pigmentação da Pele/fisiologia , Fatores de Transcrição/genética , Ácido 8,11,14-Eicosatrienoico/farmacologia , Animais , Antioxidantes/farmacologia , Células Cultivadas , Colforsina/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/efeitos da radiação , Humanos , Luciferases/genética , Melanócitos/fisiologia , Fator de Transcrição Associado à Microftalmia , Monofenol Mono-Oxigenase/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/efeitos da radiação , Resveratrol , Pigmentação da Pele/efeitos dos fármacos , Pigmentação da Pele/efeitos da radiação , Estilbenos/farmacologia , Suínos , Ácido Tióctico/farmacologia , Raios Ultravioleta
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