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1.
Toxins (Basel) ; 12(2)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32046144

RESUMO

In order to explore effects of low levels of continuous microcystin-LR (MC-LR) (a cyanotoxin) exposure on hepatic lipid metabolism on the basis of the endoplasmic reticulum stress (ERS) pathway, we exposed adult male zebrafish to MC-LR (0, 1, 5, and 25 µg/L) for 60 days, and hepatic histopathology as well as lipid metabolic parameters were determined with mRNA levels of ERS signal molecules and downstream factors, along with genes associated with lipid metabolism in zebrafish liver. The results revealed that prolonged exposure to MC-LR remarkably altered the levels of hepatic total cholesterol and triglyceride and led to hepatic steatosis, which was also confirmed by hepatic cytoplasmic vacuolization in Hematoxylin/eosin (H&E) stain and lipid droplet accumulation in Oil Red O stain. The severity of hepatic damage and lipidation was increased in a dose-related manner. MC-LR exposure significantly upregulated transcriptional levels of ERS markers including hspa5, mapk8, and chop, indicating the occurrence of ERS in the liver of zebrafish. Concurrently, MC-LR significantly improved mRNA expression of unfolded protein response (UPR) pathway-related genes including atf6, eif2ak3, ern1, and xbp1s, suggesting that all of the three UPR branches were activated by MC-LR. MC-LR also induced significant upregulation of downstream lipid metabolism-related factors and genes including srebf1, srebf2, fatty acid synthase (fasn), acetyl-CoA carboxylase (acaca), stearoyl-CoA desaturase (scd), HMG CoA reductase (hmgcra), and HMG CoA synthase (hmgcs1), and downregulation of genes associated with lipolysis such as triglyceride hydrolase gene (atgl), hormone-sensitive enzyme gene (hsla), and carnitine palmitoyltransferase gene (cpt1aa). Our present results indicated that the cause of hepatic lipid accumulation by MC-LR was mainly by upregulating lipogenic and cholesterol genes but downregulating the expression of lipolytic genes through the induction of srebf1 and srebf2, which were involved in the activation of ERS signal pathways.

2.
Sci Total Environ ; 699: 134286, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31677462

RESUMO

Fenton-like processes have emerged as most promising techniques for generating reactive oxygen-containing radicals to deal with increasing levels of environmental pollution. Developing novel catalysts with simple manufacturing requirements, excellent activity levels, and stability remains a long-term goal in terms of practical application. So herein, a new polyethylene terephthalate (PET) non-woven fabric based composite catalyst has been fabricated, using radiation-induced graft polymerization of a functionalized group to chelate Co2+ ions as heterogeneous catalysts in peroxymonosulfate (Oxone) activation. Several impact factors, including catalyst dosage, Oxone concentration, reaction temperature, pH value, Co2+ precipitation ratio (of Co@PET at different pH values), and highly concentrated NaCl have been investigated here. Notably, Co@PET has shown the lowest activation energy of any reported catalyst, for degrading RhB by activating Oxone. Interestingly, as experimental RhB and Oxone solutions were passed through single Co@PET sheets, the RhB was decomposed into a colorless solution in the penetration process. Based on radical trapping and quenching experiments, a channel was determined to dominate RhB degradation, and furthermore, Co@PET could be re-used for RhB degradation by activating Oxone. These results showed that Co@PET effectively provided improved Fenton-like catalytic performance and stability, and was suitable for practical applications.

3.
Nanomaterials (Basel) ; 9(10)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31581599

RESUMO

Functional textiles with unique functions, including free cutting, embroidery and changeable shape, will be attractive for smart wear of human beings. Herein, we fabricated a sandwich-like humidity sensor made from silver coated one-dimensional magnetite nanowire (Fe3O4 NW) arrays which were in situ grown on the surface of modified polypropylene nonwoven fabric via simultaneous radiation induced graft polymerization and co-precipitation. The humidity sensor exhibits an obvious response to the relative humidity (RH) ranging from RH 11% to RH 95% and its response value reaches a maximum of 6600% (ΔI/I0) at 95% relative humidity (RH). The humidity sensor can be tailored into various shapes and embroidered on its surface without affecting its functionalities. More interesting, the intensity of its response is proportional to the size of the material. These features permit the sensor to be integrated into commercial textiles or a gas mask to accurately monitor a variety of important human activities including respiration, blowing, speaking and perspiration. Moreover, it also can distinguish different human physical conditions by recognizing respiration response patterns. The sandwich-like sensor can be readily integrated with textiles to fabricate promising smart electronics for human healthcare.

4.
Exp Biol Med (Maywood) ; : 1535370218813988, 2018 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-30472883

RESUMO

IMPACT STATEMENT: Our study reveals that TETA, traditionally regarded as a copper chelator, in lower doses delivers copper selectively to the heart through a mechanism independent of copper transporter-1 or -2. Copper supplementation by a lower dose of TETA suppresses pressure overload-induced cardiac hypertrophy. Since ischemic heart disease and hypertrophic cardiomyopathy are accompanied by myocardial copper loss, this approach of using a lower dose of TETA to supplement copper to the heart would help treat the disease condition of patients with such cardiac events.

5.
Metallomics ; 10(1): 201-208, 2018 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-29302675

RESUMO

Trientine (TETA), a copper (Cu) chelator, is capable of replenishing Cu in the heart, and Cu repletion reduces cardiac fibrosis in a rodent model of cardiac hypertrophy. This study was undertaken to explore possible mechanisms by which Cu repletion diminishes cardiac fibrosis. Adult male Sprague-Dawley rats were subjected to ascending aortic constriction to induce cardiac hypertrophy. Four months after the operation, cardiac hypertrophy along with fibrosis was fully developed. TETA treatment was then followed at a dose of 21.9 mg kg-1, twice a day, administered orally for six weeks. At the end of the treatment, the hearts were harvested and all of the tissue samples were subjected to qRT-PCR, western blot, Sirius red staining, hydroxyproline assay, and immunostaining analyses. TETA treatment significantly increased the content of Cu in the hypertrophied myocardium, decreased type III collagen deposition and reduced cardiac fibrosis. On the other hand, this treatment did not alter the increase in fibroblasts induced by pressure overload, but significantly increased matrix metalloproteinase-2 (MMP-2), which is the enzyme mainly responsible for degradation of collagens in the heart. In addition, the mRNA and protein levels of tissue inhibitors of matrix metalloproteinase-1 and -2 (TIMP-1 and TIMP-2) were both remarkably increased in the hypertrophic myocardium, and normalized after TETA treatment. The data thus demonstrated that the reduction in cardiac fibrosis by TETA-induced Cu repletion is associated at least in part with an enhanced MMP-2 activity, leading to collagen degradation.


Assuntos
Cardiomegalia/enzimologia , Cardiomiopatias/enzimologia , Cobre/farmacologia , Fibrose/enzimologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Miocárdio/enzimologia , Trientina/farmacologia , Animais , Cardiomegalia/patologia , Cardiomegalia/prevenção & controle , Cardiomiopatias/patologia , Cardiomiopatias/prevenção & controle , Modelos Animais de Doenças , Fibrose/patologia , Fibrose/prevenção & controle , Masculino , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Miocárdio/patologia , Ratos , Ratos Sprague-Dawley , Inibidor Tecidual de Metaloproteinase-1/genética , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Inibidor Tecidual de Metaloproteinase-2/genética , Inibidor Tecidual de Metaloproteinase-2/metabolismo
6.
Cardiovasc Toxicol ; 18(4): 304-311, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29204738

RESUMO

Myocardial fibrogenesis is initiated once the coordination between oxygen supply and demand is disrupted in pressure overload-induced cardiac hypertrophy. Clinical observations showed that myocardial fibrosis did not evenly occur in the hypertrophic myocardium. The present study was undertaken to specifically address differential vulnerabilities to fibrogenesis of different regions in the myocardium subjected to pressure overload-induced hypertrophy. SD rats were divided into two groups, sham-operated control and ascending artery constriction-induced cardiac hypotrophy. Thirty-four weeks after surgery, rats were sacrificed and hearts were harvested. Myocardial tissues were processed and sequentially sectioned for detection of collagen deposition, myocyte hypertrophy and vascular density analysis. Redundant collagen stained with Sirius red and anti-collagen I antibody was found in the extracellular matrix, but high volume of collagen fraction was largely localized more in posterior and lateral walls than in anterior wall and interventricular septum, which is in accordance with the accumulation of fibroblasts. In association with the differential regional collagen accumulation, the cardiomyocytes were more hypertrophic in the posterior and lateral wall than the other left ventricle. However, the capillary density in the lateral and posterior walls was significantly decreased. The results indicated that the posterior and lateral walls were more vulnerable to fibrogenesis post-pressure overload-induced cardiac hypertrophy, which was associated with the depressed angiogenesis in these two regions.


Assuntos
Capilares/patologia , Hipertrofia Ventricular Esquerda/patologia , Miocárdio/patologia , Neovascularização Patológica , Função Ventricular Esquerda , Remodelação Ventricular , Animais , Colágeno Tipo I/metabolismo , Modelos Animais de Doenças , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose , Hipertrofia Ventricular Esquerda/metabolismo , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Ratos Sprague-Dawley
7.
Opt Express ; 23(11): 14596-602, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26072819

RESUMO

We demonstrated a compact and highly-sensitive curvature sensor based on a Mach-Zehnder interferometer created in a photonic crystal fiber. Such a Mach-Zehnder interferometer consisted of a peanut-like section and an abrupt taper achieved by use of an optimized electrical arc discharge technique, where only one dominating cladding mode was excited and interfered with the fundamental mode. The unique structure exhibited a high curvature sensitivity of 50.5 nm/m-1 within a range from 0 to 2.8 m-1, which made it suitable for high-sensitivity curvature sensing in harsh environments. Moreover, it also exhibited a temperature sensitivity of 11.7 pm/°C.


Assuntos
Interferometria/métodos , Fibras Ópticas , Simulação por Computador , Cristalização , Microscopia Eletrônica de Varredura , Análise Numérica Assistida por Computador , Fótons
8.
Psychol Health Med ; 19(2): 190-200, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23654216

RESUMO

The purpose of the study is to explore the disclosure of same-sex behavior by men who have sex with men (MSM) to different groups of people (i.e. family, friends, coworkers, and doctors) and the associated sociodemographic, behavioral, and psychosocial factors. A self-administered survey was conducted among 307 migrant MSM, aged 18-30, in Beijing in 2009. Most MSM disclosed their same-sex behavior to friends (69%), followed by family (25%), coworkers (25%), and doctors (24%). Factors associated with disclosure to friends included higher levels of perceived stigma, social capital and acculturation in Beijing, and suspecting partner to have a sexually transmitted disease (STD). Factors associated with disclosure to family included lower levels of internalized stigma, higher levels of acculturation in Beijing, and both risk and protective behavioral factors. MSM who disclosed to coworkers reported having worked in more cities, living with coworkers, and lower levels of social capital in Beijing. Disclosure to doctors was related to STD infection, sex partner, and sociodemographic factors. Results indicated that selective disclosure by MSM was situational and context-based. Future HIV/STD intervention needs to take into account factors relevant to their selective disclosure to different audiences.


Assuntos
Homossexualidade Masculina/psicologia , Autorrevelação , Migrantes/psicologia , Aculturação , Adolescente , Adulto , Bissexualidade/psicologia , China/etnologia , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Assunção de Riscos , Estigma Social , Apoio Social , Adulto Jovem
9.
AIDS Care ; 23(2): 179-86, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21259130

RESUMO

Previous studies suggested a rapid increase of HIV prevalence among men who have sex with men (MSM) in China in recent years, from 0.4% in 2004 to 5.8% in 2006. However, some MSM had never been tested for HIV. In order to expand the accessibility to HIV testing, understanding HIV-testing behavior and barriers among MSM is important. Using data collected from 307 young migrant MSM (aged 18-29 years) in 2009 in Beijing, we aimed to identify psychological and structural barriers to HIV testing. MSM were recruited through peer outreach, informal social networks, Internet outreach, and venue-based outreach. Participants completed a confidential self-administered questionnaire. Results show that about 72% of MSM ever had an HIV test. Logistic regression analysis indicated that the HIV-testing behavior was associated with sexual risk behaviors (e.g., multiple sexual partners and inconsistent condom use for anal sex) and history of sexually transmitted diseases. Eighty four MSM (28%) who never had an HIV test reported that the psychological barriers mainly were perceived low risk of HIV infection and fears of being stigmatized. The structural barriers reported inconvenience of doing test and lack of confidentiality. Future HIV prevention programs should be strengthened among MSM to increase their awareness of HIV risk. Efforts are needed to increase access to quality and confidential HIV testing among MSM and reduce stigma against MSM.


Assuntos
Infecções por HIV/psicologia , Acesso aos Serviços de Saúde , Homossexualidade Masculina , Migrantes , Adolescente , Adulto , China , Infecções por HIV/diagnóstico , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Assunção de Riscos , Doenças Sexualmente Transmissíveis/diagnóstico , Doenças Sexualmente Transmissíveis/psicologia , Estigma Social , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto Jovem
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