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1.
Chem Biodivers ; 16(10): e1900443, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31468670

RESUMO

Chronic myelogenous leukemia (CML) is a disease of the blood stem cells that features the oncoprotein Bcr-Abl. Tyrosine kinase inhibitors (TKIs) are used to treat CML patients, but these have limited efficacy due to the emergence of resistance via genetic mutation. Kamebakaurin is an ent-kaurane diterpenoid that has been isolated from Rabdosia excisa (Maxim.) H.Hara. Herein, we investigate the potential of kamebakaurin as a chemotherapy reagent for the treatment of CML. We conducted in vitro and in vivo biological experiments and found that kamebakaurin potently inhibits cell proliferation, mainly by enhancing cell apoptosis and down-regulating Bcr-Abl protein levels. In addition, kamebakaurin was found to inhibit tumor growth and has no side effects on five internal organs for in vivo experiment. These results suggest that kamebakaurin is a potential anticancer agent and is a key compound for further investigations.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Diterpenos/farmacologia , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Isodon/química , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Diterpenos/química , Diterpenos/isolamento & purificação , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas de Fusão bcr-abl/metabolismo , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Conformação Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Relação Estrutura-Atividade
2.
Adv Healthc Mater ; 7(15): e1800207, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29770610

RESUMO

An ideal vascular stent would both inhibit in-stent restenosis (ISR) and promote rapid re-endothelialization. In the current study, the performance of arsenic trioxide (ATO)-drug eluting stent (AES) is compared with the bare metal stent, poly-lactic-co-glycolic acid-coating metal stent, and rapamycin-drug eluting stent (RES). In vivo AES is shown to prevent neointimal hyperplasia more efficiently than the others when implanted into the carotid arteries of rabbits. Moreover, AES promotes endothelial cells proliferation and re-endothelialization more quickly than RES. In vitro ATO exposure significantly increases the viability, proliferation, adhesion, and spreading of primary porcine coronary artery endothelial cells (PCAECs), which are critical for endothelialization. However, ATO exposure reduces the viability of porcine coronary artery smooth muscle cells (PCASMCs). The evaluation of mitochondrial morphology, membrane potential, and function demonstrates that ATO at 2 µmol L-1 causes enlargement of the mitochondrion, enhancement of mitochondrial membrane potential, and adenosine triphosphate (ATP) production in PCAECs but not in PCASMCs. Thus, both in vivo and in vitro studies demonstrate that AES is an effective strategy for rapid re-endothelialization and inhibition of ISR.

3.
Nanomaterials (Basel) ; 8(2)2018 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-29462938

RESUMO

Two dimensional (2D)SnO2 nanosheets were synthesized by a substrate-free hydrothermal route using sodium stannate and sodium hydroxide in a mixed solvent of absolute ethanol and deionized water at a lower temperature of 130 °C. The characterization results of the morphology, microstructure, and surface properties of the as-prepared products demonstrated that SnO2 nanosheets with a tetragonal rutile structure, were composed of oriented SnO2 nanoparticles with a diameter of 6-12 nm. The X-ray diffraction (XRD) and high-resolution transmission electron microscope (FETEM) results demonstrated that the dominant exposed surface of the SnO2 nanoparticles was (101), but not (110). The growth and formation was supposed to follow the oriented attachment mechanism. The SnO2 nanosheets exhibited an excellent sensing response toward ethylene glycol at a lower optimal operating voltage of 3.4 V. The response to 400 ppm ethylene glycol reaches 395 at 3.4 V. Even under the low concentration of 5, 10, and 20 ppm, the sensor exhibited a high response of 6.9, 7.8, and 12.0 to ethylene glycol, respectively. The response of the SnO2 nanosheets exhibited a linear dependence on the ethylene glycol concentration from 5 to 1000 ppm. The excellent sensing performance was attributed to the present SnO2 nanoparticles with small size close to the Debye length, the larger specific surface, the high-energy exposed facets of the (101) surface, and the synergistic effects of the SnO2 nanoparticles of the nanosheets.

4.
ACS Appl Mater Interfaces ; 8(11): 7578-89, 2016 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-26925508

RESUMO

We studied the effects of gene transfection of endothelial cells with vascular endothelial growth factor (VEGF) on re-endothelialization and inhibition of in-stent restenosis. Transfected endothelial cells (ECs) exposed to different VEGF levels were seeded on a stent surface for evaluation in vitro. VEGF121(++) ECs and VEGF121(--) ECs were established using lentiviral-mediated HUVECs transfection. VEGF RNA transcription level and VEGF protein expression were detected by qPCR, Western blot, and ELISA. Methyl thiazolyl tetrazolium (MTT) assay, wound healing assay, and in vitro HUVEC tube formation assay showed that VEGF overexpression promoted cell proliferation, migration, and endothelial capillary-like tube formation. Downregulation of VEGF expression inhibited these activities. Using a rotational culturing system, cells tightly adhered on the stent surface. Stents seeded with transfected ECs at different VEGF levels were implanted in abdominal aortas of New Zealand white rabbits to study re-endothelialization and inhibition of in-stent restenosis. Stents with cells exposed to excess VEGF expression were almost completely covered with cells after stent implantation for 1 week (w). In the VEGF interference group this process was delayed over 4 w due to RNAi-mediated silencing of VEGF. Cryosectioning after 12 w showed that stents seeded with HUVECs exposed to excess VEGF expression significantly reduced the neointima area and stenosis when compared with bare metal stents and stents from the VEGF interference group. Transgenic HUVECs were not found in tissues of experimental animals. Furthermore, cells from these tissues were similar to those from normal tissue. In conclusion, VEGF-mediated endothelialization was found. Furthermore, ECs exposed to VEGF overexpression reduced neointimal hyperplasia, promoted endothelialization, and reduced in-stent restenosis.


Assuntos
Regulação para Baixo , Neointima/metabolismo , Stents , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/biossíntese , Animais , Células HEK293 , Células Endoteliais da Veia Umbilical Humana , Humanos , Neointima/genética , Neointima/patologia , Coelhos , Fator A de Crescimento do Endotélio Vascular/genética
5.
Regen Biomater ; 2(2): 87-96, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26813006

RESUMO

It is not clear what effects of CD34- and CD133-specific antibody-coated stents have on re-endothelialization and in-stent restenosis (ISR) at the early phase of vascular injury. This study aims at determining the capabilities of different coatings on stents (e.g. gelatin, anti-CD133 and anti-CD34 antibodies) to promote adhesion and proliferation of endothelial progenitor cells (EPCs). The in vitro study revealed that the adhesion force enabled the EPCs coated on glass slides to withstand flow-induced shear stress, so that allowing for the growth of the cells on the slides for 48 h. The in vivo experiment using a rabbit model in which the coated stents with different substrates were implanted showed that anti-CD34 and anti-CD133 antibody-coated stents markedly reduced the intima area and restenosis than bare mental stents (BMS) and gelatin-coated stents. Compared with the anti-CD34 antibody-coated stents, the time of cells adhesion was longer and earlier present in the anti-CD133 antibody-coated stents and anti-CD133 antibody-coated stents have superiority in re-endothelialization and inhibition of ISR. In conclusion, this study demonstrated that anti-CD133 antibody as a stent coating for capturing EPCs is better than anti-CD34 antibody in promoting endothelialization and reducing ISR.

6.
Wei Sheng Wu Xue Bao ; 52(9): 1160-6, 2012 Sep 04.
Artigo em Chinês | MEDLINE | ID: mdl-23236851

RESUMO

OBJECTIVE: To identify a thermophilic bacterium from horse manure to degrade cellulose efficiently, and to enrich microbial resources producing cellulolytic ethanol by co-culturing with thermophilic ethanol producing bacterium. METHODS: We used Hungate anaerobic technique to isolate a strain named as HCp from horse manure mixed culture; its phylogeny was identified through 16S rDNA sequencing. Enzymatic assays were determined using DNS method. RESULTS: The isolated HCp cells were straight with rods size of(0.35-0.50) microm x (2.42-6.40) microm, in the form of single or paring. This strain belongs to a strictly anaerobic Gram-negative bacterium, it is able to form spores, shows motile ability and resistance to neomycin. The strain could degrade filter paper cellulose, cellulose powder, microcrystalline cellulose, cotton wool, rice straw and gelatin, and it was also able to utilize abundant saccharides as substrates such as cellobiose, glucose, xylose, xylan, raffinose, maltose, sorbose, fructose and galactose. The growth pH ranges from 6.5 to 8.5, temperature from 35 to 70 degrees C and concentration of NaCl on cellulose from 0% to 1.0%, while the optima of pH 6.85, 60 degreesC and 0.2% NaCl. Under the optimal growth conditions, the filter paper cellulose degradation rate was up to 90.40% after 10 days. The optimum temperatures for FPA, CMCase, beta-glucosidase and xylanase were 70 degrees C, 70 degrees C, 70 degrees C, and 60 degrees C respectively. CMCase activity was found with high thermal stability. The phylogenetic analysis based on partial 16S rDNA revealed that HCp was close to Acetivibrio cellulolyticus and A. cellulosolvens with 97.5% sequence similarities. CONCLUSION: Strain HCp is thermophilic, efficiently cellulolytic anaerobe. It is able to utilize vast substrates and produce highly thermostable enzymes. It is a potential bacterium that can be used for cellulolytic ethanol production.


Assuntos
Bactérias Anaeróbias/enzimologia , Bactérias Anaeróbias/isolamento & purificação , Proteínas de Bactérias/química , Celulases/química , Fezes/microbiologia , Animais , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Celulases/genética , Celulases/metabolismo , Celulose/metabolismo , Estabilidade Enzimática , Cavalos , Temperatura Alta , Cinética , Dados de Sequência Molecular , Filogenia , Especificidade por Substrato
7.
Ecol Evol ; 2(9): 2285-90, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23139886

RESUMO

The H(2) is an obligate by-product of N-fixation. Recycling of H(2) through uptake hydrogenase (Hup) inside the root nodules of leguminous plants is often considered an advantage for plants. However, many of the rhizobium-legume symbioses found in nature, especially those used in agriculture are shown to be Hup(-), with the plants releasing H(2) produced by nitrogenase activity from root nodules into the surrounding rhizosphere. Recent studies have suggested that, H(2) induces plant-growth-promoting rhizobacteria, which may explain the widespread of Hup(-) symbioses in spite of the low energy efficiency of such associations. Wild legumes grown in Nova Scotia, Canada, were surveyed to determine if any plant-growth characteristics could give an indication of Hup choice in leguminous plants. Out of the plants sampled, two legumes, Securigera varia and Vicia cracca, showed Hup(+) associations. Securigera varia exhibited robust root structure as compared with the other plants surveyed. Data from the literature and the results from this study suggested that plants with established root systems are more likely to form the energy-efficient Hup(+) symbiotic relationships with rhizobia. Conversely, Hup(-) associations could be beneficial to leguminous plants due to H(2)-oxidizing plant-growth-promoting rhizobacteria that allow plants to compete successfully, early in the growing season. However, some nodules from V. cracca tested Hup(+), while others were Hup(-). This was similar to that observed in Glycine max and Pisum sativum, giving reason to believe that Hup choice might be affected by various internal and environmental factors.

8.
Zhong Yao Cai ; 30(9): 1059-61, 2007 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-18236744

RESUMO

The cotyledons and hypecotyl of Sedum hybridum were used as explant to induce calluse on MS media supplemented with different concentration of hormone. There were formed two kind of calluses, one was red while other was green. The cotyledon was the ideal explant for the callus induction, its induction rate could be reached 80% - 82% either on MS medium with 6-BA 1 mg/L and 2,4-D 0.5 mg/L or with 6-BA 1 mg/L and NAA 0.5 mg/L. Numerous adventitious buds could formed from calluses on the MS medium with 6-BA 2 mg/L and NAA 0.5 mg/L. The medium for the root growth was 1/2 MS. The tube seedling which can be successfully transplanted at 80% survival.


Assuntos
Crassulaceae/fisiologia , Plantas Medicinais/fisiologia , Regeneração/fisiologia , Crassulaceae/efeitos dos fármacos , Meios de Cultura/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/fisiologia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/fisiologia , Plantas Medicinais/efeitos dos fármacos , Regeneração/efeitos dos fármacos , Técnicas de Cultura de Tecidos/métodos
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