Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Small ; 15(47): e1904245, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31617305

RESUMO

Perforated ultrathin Pd nanosheets with crystalline/amorphous heterostructures are rationally synthesized to offer a large electrochemically active surface area of 172.6 m2 g-1 and deliver a 5.6 times higher apparent reaction rate in comparison to commercial Pd/C, thus offering a facile confined growth method to generate superior catalysts.

2.
J Colloid Interface Sci ; 552: 633-638, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31170616

RESUMO

Integrating nanoscale active materials on conductive holey reduced graphene oxide (RGO) framework is an effective strategy to synthesize composite electrode materials for advanced lithium-ion batteries. Herein, a composite of γ-Fe2O3 nanoparticles stabilized by the engineered holes on RGO was successfully synthesized by using a facile in-situ etching route, which exhibited high lithium storage performance. The fundamental insight of its enhancement mechanism was discussed. This work offers a newly route to synthesize the composite of holey RGO confined metal oxide nanoparticles for the applications in lithium ion batteries and beyond.

3.
J Colloid Interface Sci ; 548: 233-243, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31004956

RESUMO

A novel and simple approach to preparing hierarchical zinc oxide/reduced graphene oxide (ZnO/RGO@RGO) composite is demonstrated using few-layered graphene oxide (GO) and metal zinc as starting materials following combined processes, including in-situ metal zinc reduction and catalyzed GO deoxygenation. Metal zinc can directly reduce GO sheets in aqueous GO suspension at room temperature to obtain a porous composite precursor (ZnO/RGO) with ZnO nanoparticles anchored on the RGO sheets. Then another RGO protecting layer is directly coated on the ZnO/RGO precursor to obtain the hierarchical ZnO/RGO@RGO composite. In this step, the exposed ZnO nanoparticles on the surface of ZnO/RGO play the role of catalyst to accelerate the deoxygenation of GO from the extra added GO aqueous suspension under mild hydrothermal condition. The reaction mechanism of metal zinc with GO aqueous suspension has been explored and the catalyst role of ZnO has been verified in this work. The prepared ZnO/RGO@RGO composite exhibited both stable cycling performance and good rate capability as anode for lithium-ion batteries. The method to prepare ZnO/RGO composite is economic and eco-friendly, and the ZnO catalyzing GO reduction opens a new approach to prepare graphene derivates.

4.
Artigo em Inglês | MEDLINE | ID: mdl-30398329

RESUMO

Ternary metal-element alloys have been reported as efficient electrocatalysts toward various electrochemical reactions, but a unique three-dimensional (3D) Ir-alloyed ternary nanosheet-composed flower (NCF) structure has not been explored yet. Herein, an innovated 1.8 nm Ir-alloyed ultrathin ternary PdIrCu NCF structure is synthesized via one-pot solvothermal reduction without using any surfactant. The as-prepared PdIrCu/C NCF catalyst remarkably improves the stability than commercial Pd/C toward formic acid electrooxidation while resulting in significantly increased mass activity. The improvement of electrocatalytic properties depends on the introduction of Ir and Cu atoms, which greatly prevented poisoning from CO while modifying the electronic structure of Pd for increased reaction active sites and accelerated charge-transfer rate as well as facilitated mass transport by ultrathin NCF 3D structure. Therefore, this catalyst possesses a promising application prospect in electrochemical energy storage/conversion systems.

5.
J Colloid Interface Sci ; 537: 366-374, 2018 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-30453230

RESUMO

Twisted PdCu nanochains are synthesized successfully via a staged thermal treatment route, offering rich twin boundaries as catalytic "active sites" and modified electronic effects. Toward formic acid oxidation, the twisted PdCu nanochains hold the highest catalytic peak current density (1108.2 mA mg-1Pd) over previous reported PdCu alloy catalysts, and also much higher catalytic activity and durability comparing with Pd nanochains and commercial Pd/C. The catalytic enhancement mechanism to PdCu nanochains is proposed and discussed. Additionally, we found that the formation of PdCu nanochains follows a typical anisotropic growth approach, and the multiple steps of staged thermal treatment route displays a vital role in fabricating the unique PdCu nanochains while the introduced Cu precursors might affect the reduction rate of Pd species and act as deposition or nucleation sites for twisted structure in terms of rich twin boundaries. This work describes an efficient, low-Pd loading catalyst for electrooxidation of formic acid, and also demonstrates a universal method to fabricate other defect-rich catalysts for broad applications in energy conversion and storage systems and sensing devices.

6.
J Colloid Interface Sci ; 530: 189-195, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29982010

RESUMO

Unique and novel Pd4Sn nanochain networks were successfully synthesized with an average diameter of 5 nm, rendering a modified Pd electronic structure with rich defects such as atomic corners, steps or ledges as catalytic active sites for great enhancement of charge transfer and electrode kinetics. The prepared Pd4Sn nanochain networks held an electrochemically active surface area as high as 119.40 m2 g-1, and exhibited higher catalytic activity and stability toward formic acid oxidation compared with Pd3Sn nanochain networks, Pd5Sn nanochain networks, Pd4Sn dendrites and Pd/C. The fundamental insight of the enhancement mechanism is discussed, and this work offers a novel, less expensive but highly active catalyst for direct formic acid fuel cells.

7.
Biomed Environ Sci ; 30(9): 671-675, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29081342

RESUMO

We assessed the role of diabetes mellitus (DM) on treatment effects in drug-susceptible initial pulmonary tuberculosis (PTB) patients. A prospective study was conducted in eight provinces of China from October 2008 to December 2010. We enrolled 1,313 confirmed drug-susceptible initial PTB patients, and all subjects received the treatment regimen (2H3R3E3Z3/4H3R3) as recommended by the national guidelines. Of the 1,313 PTB patients, 157 (11.9%) had DM; these patients had more sputum smear-positive rates at the end of the second month [adjusted odds ratios (aOR) 2.829, 95% confidence intervals (CI) 1.783-4.490], and higher treatment failure (aOR 2.120, 95% CI 1.565-3.477) and death rates (aOR 1.536, 95% CI 1.011-2.628). DM was a contributing factor for culture-positive rates at the end of the second month and treatment failure and death of PTB patients, thus playing an unfavorable role in treatment effects of PTB.


Assuntos
Antituberculosos/uso terapêutico , Diabetes Mellitus/terapia , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologia , China/epidemiologia , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Masculino , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose Pulmonar/complicações , Tuberculose Pulmonar/epidemiologia
8.
J Colloid Interface Sci ; 505: 783-788, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28672257

RESUMO

An effective strategy of ultrasmall and surface-clean Pd4Ir nanocrystals uniformly decorated on graphene was developed using ultrasnoic-assisted approach. The prepared Us-Pd4Ir@Graphene reduces Pd loading while holds much higher catalytic activity and better stability toward formic acid oxidation than that of commercial Pd-C, offering great promise as a superior anode catalyst for direct formic acid fuel cells.

9.
J Colloid Interface Sci ; 506: 135-143, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-28734150

RESUMO

Uniform Pt1Ru0.5Sn0.5 ternary alloy nanoparticles are in situ deposited on reduced graphene oxide (Pt1Ru0.5Sn0.5-RGO) through its functional groups and defects as nucleation sites to greatly electrocatalyze ethanol oxidation reaction for much higher mass current densities, larger apparent specific current densities and better stability than commercial Pt-C catalyst (Pt-C(commer)). Mechanistic studies indicate that the excellent electrocatalytic activity and anti-poisoning are resulted from a strong ligand effect of the ternary alloy components, in which the charge transfer is boosted while decreasing the density of states close to the Fermi level of Pt to reduce bond energy between Pt and CO-like adsorbates for greatly improved anti-poisoning ability. This work holds a great promise to fabricate a high performance anode catalyst with a low Pt loading for direct ethanol fuel cells.

10.
Biomed Environ Sci ; 29(8): 612-617, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27660228

RESUMO

The objective of this prospective study of the risks of treatment failure in patients with drug-susceptible pulmonary tuberculosis (PTB) was to provide reference data to help develop a disease control strategy. Participants were recruited in eight provinces of China from October 2008 to December 2010. A total of 1447 patients with drug-susceptible PTB and older than 15 years of age were enrolled. Demographic characteristics, bacteriological test results, and patient outcome, i.e., cure or treatment failure were recorded and compared using the chi-square or Fisher's exact tests. Multivariate logistic regression was used to identify factors associated with risk of treatment failure. Of the 1447 patients who were enrolled, 1349 patients (93.2%) were successfully treated and 98 (6.8%) failed treatment. Failure was significantly associated with age 365 years [odds ratio (OR)=2.522, 95% confidence interval (CI): (1.097-5.801)], retreatment [OR=2.365, 95% CI: (1.276-4.381)], missed medicine [OR=1.836, 95% CI: (1.020-3.306)], treatment not observed [OR=1.879 95% CI: (1.105-3.195)], and positive culture result after the first [OR=1.971, 95% CI: (1.080-3.597)] and second month [OR=4.659, 95% CI: (2.590-8.382)]. The risk factors associated with treatment failure were age 365 years, retreatment, missed medication, treatment not observed, and positive culture at the end of month 1 or month 2. These risk factors should be monitored during treatment and interventions carried out to reduce or prevent treatment failure and optimize treatment success.


Assuntos
Antituberculosos/uso terapêutico , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológico , Adolescente , Adulto , Idoso , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/fisiologia , Estudos Prospectivos , Retratamento , Fatores de Risco , Falha de Tratamento , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/microbiologia , Adulto Jovem
11.
J Colloid Interface Sci ; 476: 200-205, 2016 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-27218808

RESUMO

An adsorbent, γ-Fe2O3 nanocrystals-anchored macro/meso-porous graphene was synthesized by metal etching approach toward removal of methylene blue, exhibiting rapid adsorption rate, high adsorption capacity and good recyclability, thus holding a great promise for treatment of methylene blue in wastewater.

12.
Nanoscale ; 8(4): 1905-9, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26753911

RESUMO

Ultrasmall and uniform Pd6Co nanocrystals were deposited on 3D graphene by a facile one-pot surfactant-free route for a catalyst toward formic acid oxidation, showing a much higher electrocatalytic activity, larger peak current density and better stability than Pd/3DG, Pd/C as well as commercial Pd-C, and thus offering great potential for an efficient anode catalyst toward high performance direct formic acid fuel cells.

13.
Arch Toxicol ; 89(2): 233-42, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24819616

RESUMO

Perfluoroalkyl compounds (PFCs) have been shown to disrupt thyroid functions through thyroid hormone receptor (TR)-mediated pathways, but direct binding of PFCs with TR has not been demonstrated. We investigated the binding interactions of 16 structurally diverse PFCs with human TR, their activities on TR in cells, and the activity of perfluorooctane sulfonate (PFOS) in vivo. In fluorescence competitive binding assays, most of the 16 PFCs were found to bind to TR with relative binding potency in the range of 0.0003-0.05 compared with triiodothyronine (T3). A structure-binding relationship for PFCs was observed, where fluorinated alkyl chain length longer than ten, and an acid end group were optimal for TR binding. In thyroid hormone (TH)-responsive cell proliferation assays, PFOS, perfluorohexadecanoic acid, and perfluorooctadecanoic acid exhibited agonistic activity by promoting cell growth. Furthermore, similar to T3, PFOS exposure promoted expression of three TH upregulated genes and inhibited three TH downregulated genes in amphibians. Molecular docking analysis revealed that most of the tested PFCs efficiently fit into the T3-binding pocket in TR and formed a hydrogen bond with arginine 228 in a manner similar to T3. The combined in vitro, in vivo, and computational data strongly suggest that some PFCs disrupt the normal activity of TR pathways by directly binding to TR.


Assuntos
Fluorcarbonetos/metabolismo , Receptores dos Hormônios Tireóideos/metabolismo , Ligação Competitiva , Fluorescência , Fluorcarbonetos/química , Humanos , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade
14.
Sci Rep ; 3: 2333, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23903585

RESUMO

The heavy metal cadmium is a non-degradable pollutant. By screening the effects of a panel of metal ions on the phosphatase activity, we unexpectedly identified cadmium as a potent inhibitor of PPM1A and PPM1G. In contrast, low micromolar concentrations of cadmium did not inhibit PP1 or tyrosine phosphatases. Kinetic studies revealed that cadmium inhibits PPM phosphatases through the M1 metal ion binding site. In particular, the negative charged D441 in PPM1G specific recognized cadmium. Our results suggest that cadmium is likely a potent inhibitor of most PPM family members except for PHLPPs. Furthermore, we demonstrated that cadmium inhibits PPM1A-regulated MAPK signaling and PPM1G-regulated AKT signaling potently in vivo. Cadmium reversed PPM1A-induced cell cycle arrest and cadmium insensitive PPM1A mutant rescued cadmium induced cell death. Taken together, these findings provide a better understanding of the effects of the toxicity of cadmium in the contexts of human physiology and pathology.


Assuntos
Cádmio/química , Cádmio/farmacocinética , Modelos Químicos , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosfoproteínas Fosfatases/metabolismo , Sítios de Ligação , Simulação por Computador , Ativação Enzimática , Células HEK293 , Humanos , Cinética , Ligação Proteica , Proteína Fosfatase 2C
15.
Mol Biol Rep ; 40(8): 4979-84, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23686108

RESUMO

Zinc is the most common trace mineral after iron in the human body. In organisms, zinc transporters help zinc influx and efflux from cells. A previous study has reported that Zip2 was up-regulated over 27-fold in human monocytic THP-1 cells, when intracellular zinc was depleted by TPEN. Our study found Zip2 was over-expressed in leukocytes of asthmatic infants, especially those in which the serum zinc level was lower than those in healthy infants. Pulmonary tuberculosis (PTB) patients have significantly low serum zinc levels. Here we investigated whether Zip2 level was changed in the patients with PTB. Zip2 mRNA and protein levels in peripheral blood mononuclear cells (PBMC) from PTB (n1=23) and healthy controls (n2=42) were detected by quantitative real-time PCR and western blot, respectively. mRNA expression levels of another four zinc transporters, Zip1, Zip6, Zip8 and ZnT1, were detected by quantitative real-time PCR. Zip2 mRNA level was significantly up-regulated in PTB patients (P=0.001), and Zip8 mRNA level was significantly down-regulated compared with control individuals (P<0.001). In contrast, there were no significant changes in mRNA levels of Zip1, Zip6 and ZnT1 in either group (P>0.05). Zip2 protein expression levels increased in PTB patients compared with control individuals. Our study found that knockdown of ZIP2 with siRNA caused a decrease in Zip2 levels in PBMC of PTB patients, while reducing the expression of INF-γ (P<0.01) and increasing the expression of IL-6(P<0.01). These data provide evidence that increased expression of Zip2 gene is closely associated with immunity of PTB patients, suggesting that the Zip2 gene may play a key role in the initial infection control of the human body, by promoting and maintaining the immune response of adaptive T cells.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Regulação da Expressão Gênica/imunologia , Leucócitos Mononucleares/metabolismo , RNA Mensageiro/metabolismo , Tuberculose Pulmonar/imunologia , Adulto , Western Blotting , Primers do DNA/genética , Regulação da Expressão Gênica/genética , Humanos , Interferon gama/metabolismo , Interleucina-6/metabolismo , Pessoa de Meia-Idade , Interferência de RNA , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Tuberculose Pulmonar/metabolismo
16.
Chemistry ; 18(49): 15693-8, 2012 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-23060239

RESUMO

Unique DNA-promoted Pd nanocrystals on carbon nanotubes (Pd/DNA-CNTs) are synthesized for the first time, in which through its regularly arranged PO(4)(3-) groups on the sugar-phosphate backbone, DNA directs the growth of ultrasmall Pd nanocrytals with an average size of 3.4 nm uniformly distributed on CNTs. The Pd/DNA-CNT catalyst shows much more efficient electrocatalytic activity towards oxygen reduction reaction (ORR) with a much more positive onset potential, higher catalytic current density and better stability than other Pd-based catalysts including Pd nanocrystals on carbon nanotubes (Pd/CNTs) without the use of DNA and commercial Pd/C catalyst. In addition, the Pd/DNA-CNTs catalyst provides high methanol tolerance. The high electrocatalytic performance is mainly contributed by the ultrasmall Pd nanocrystal particles grown directed by DNA to enhance the mass transport rate and to improve the utilization of the Pd catalyst. This work may demonstrate a universal approach to fabricate other superior metal nanocrystal catalysts with DNA promotion for broad applications in energy systems and sensing devices.


Assuntos
DNA/química , Nanopartículas Metálicas/química , Nanopartículas/química , Nanotubos de Carbono/química , Paládio/química , Catálise , Oxirredução
17.
Zhongguo Zhen Jiu ; 30(6): 441-5, 2010 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-20578377

RESUMO

OBJECTIVE: To verify the improvement function of warming-reinforcing acupuncture combined with rehabilitation training on the early motor function of hemiparalysis patients caused by ischemic brain stroke. METHODS: Eighty cases were randomly divided into a warming-reinforcing acupuncture combined with rehabilitation training group (group A) and a rehabilitation training group (group B), 40 cases in each group. Both groups were treated with internal routine treatment. The Motor Relearning Program rehabilitation was used in group B, while warming-reinforcing acupuncture combined with Motor Relearning Program rehabilitation were used in group A. Jianyu (LI 15), Quchi (LI 11), Hegu (LI 4), Yanglingquan (GB 34), Yinlingquan (SP 9), Zusanli (ST 36), Sanyinjiao (SP 6) were selected, and warming-reinforcing method was used in these points, they were treated for 3 weeks. The neurological functional deficits scores of hemiparalysis patients, Fugl-Meyer Score, Motor Function Assessment Score (MAS), Barthel Index and Mini-mental State Examination (MMSE) were used to evaluate the condition of hemiparalysis patients before and after treatment. RESULTS: The effective rate of group A (87.5%, 35/40) superior to that of group B (67.5%, 27/40) (P < 0.05). The neurological functional deficit scores, Fugl-Meyer score, MAS and Barthel Index of both groups were improved after treatment (P < 0.01, P < 0.05), and the improved degree of group A was better than that of group B (P < 0.01, P < 0.05). CONCLUSION: There is obvious improvement function of warming-reinforcing acupuncture combined with rehabilitation training on the early motor function of hemiparalysis patients caused by ischemic brain stroke, and the function is better than that of simple rehabilitation training.


Assuntos
Terapia por Acupuntura , Isquemia Encefálica/complicações , Hemiplegia/reabilitação , Hemiplegia/terapia , Atividade Motora , Acidente Vascular Cerebral/complicações , Atividades Cotidianas , Adulto , Idoso , Idoso de 80 Anos ou mais , Hemiplegia/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
18.
J Biomater Sci Polym Ed ; 20(12): 1675-86, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19723435

RESUMO

Poly(PEGMA-MAA)-coated superparamagnetic nanoparticles were synthesized by in situ photochemical polymerization in magnetite aqueous suspension under UV irradiation. The magnetic poly(PEGMA-MAA) nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), photo correlation spectroscopy (PCS) and vibration sample magnetometry (VSM), respectively. The results indicated that the magnetic poly(PEGMA-MAA) nanoparticles were of regularly spherical shape and remained monodisperse. The average size measured in aqueous media was 96.4 nm, which was much bigger than that in dry state, the nanoparticles behaved superparamagnetic with saturated magnetization of 64.8 emu/g, the zeta potential was -18.3 mV at physiological pH 7.2, and the magnetic poly(PEGMA-MAA) nanoparticles had a high stability in vitro. A typical anti-inflammatory drug, ibuprofen, was used for drug loading, and the release behavior of ibuprofen in a simulated body fluid (SBF, pH 7.4) was studied. The results indicated that these novel magnetic nanoparticles had a high drug-loading capacity and favorable release properties for ibuprofen. The magnetic poly(PEGMA-MAA) nanoparticles are very promising for application in drug delivery.


Assuntos
Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Magnetismo , Metacrilatos/química , Nanopartículas/química , Processos Fotoquímicos , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Biomimética , Líquidos Corporais/metabolismo , Portadores de Fármacos/síntese química , Concentração de Íons de Hidrogênio , Ibuprofeno/química , Ibuprofeno/metabolismo , Tamanho da Partícula , Análise Espectral , Termogravimetria
19.
Pediatr Pulmonol ; 44(8): 763-7, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19598279

RESUMO

The increase in prevalence of asthma is strongly dependent on environmental factors, including foods. Significant decreases in the intake of dietary zinc may be an important contributing factor to the increasing incidence of asthma. As zinc can not passively diffuse across cell membranes, specific zinc transporters are required for zinc influx and efflux. There are two identified gene families involved in zinc homeostasis, ZnT transporters and ZIP transporters. In this study, we aimed to investigate the expression of these zinc transporters mRNA in the leukocytes of asthmatic infants. Asthmatic infants (n = 9) and healthy infants (n = 9) were included in this study. Five zinc transporters were chosen: ZnT-1, ZnT-3, ZnT-5, ZIP-1, and ZIP-2. Levels of zinc were determined in serum and expression of zinc transporters mRNA were measured. Serum zinc levels were significantly lower in asthmatic infants (P < 0.01); Expression of ZnT-1, ZnT-3, ZnT-5, ZIP-1 mRNA were not significantly different between two groups, but expression of ZIP-2 mRNA was significantly higher (P < 0.01) in the asthmatic group than the control group. In conclusion, overexpression of ZIP-2 mRNA was found in the leukocytes of asthmatic infants.


Assuntos
Asma/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Leucócitos/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Transporte de Cátions/genética , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Zinco/sangue
20.
Mol Biol Rep ; 35(4): 595-600, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17786585

RESUMO

Zinc is essential for cell growth. Previous studies have shown that zinc concentration in breast cancer tissues is higher than that in normal breast tissues. Zinc cannot passively diffuse across cell membranes and specific zinc transporter proteins are required. Two gene families have been identified involved in zinc homeostasis. ZnT transporters reduce intracellular zinc while ZIP transporters increase intracellular zinc. In this study, three human zinc transporter members: ZnT-1, ZIP2 and LIV-1 were chosen. We aimed to determine the effect of flaxseed lignan on the growth of ER-negative breast cancer cells in a nude mice model and observe the effect of flaxseed lignan on the regulation of the three zinc transporter in mRNA level. Nude mice were xenografted with human breast cancer cell line MDA-MB-231 and 6 weeks later were fed either the basal diet (BD) or BD supplemented with 10% FS and SDG for 5 weeks. The SDG levels were equivalent to the amounts in the 10% FS. RT-PCR was performed. Compared with the BD group, the tumor growth rate was significantly lower (P < 0. 05) in the FS and SDG group. ZnT-1 mRNA level in mammary tumor was increased in SDG group and decreased in FS group, but no significant difference was found. Extremely low amplification of ZIP2 from mRNA was detected, with no difference between the treatment groups. LIV-1 mRNA expression of SDG group increases compared with BD group. In FS group, it significantly increases nearly 9 times than that in BD group (P < 0. 005).


Assuntos
Neoplasias da Mama/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Linho/química , Lignanas/farmacologia , Proteínas de Neoplasias/metabolismo , Animais , Neoplasias da Mama/tratamento farmacológico , Butileno Glicóis/farmacologia , Linhagem Celular Tumoral , Dieta , Feminino , Glucosídeos/farmacologia , Humanos , Lignanas/administração & dosagem , Neoplasias Mamárias Experimentais/tratamento farmacológico , Camundongos , Camundongos Nus , RNA Mensageiro/metabolismo , Transplante Heterólogo/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA