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Find video protocols related to scientific articles indexed in Pubmed.
Preparation of polyhedral oligomeric silsesquioxane based hybrid monoliths by thiol-ene click chemistry for capillary liquid chromatography.
Analyst
PUBLISHED: 11-05-2014
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A facile organic-silica hybrid monolith was prepared by a thiol-ene click reaction of polyhedral oligomeric silsesquioxane methacryl substituted (POSS-MA) with 1,4-bis(mercaptoacetoxy) butane (BMAB) using toluene and dodecanol as a porogenic system. The effects of the ratio of POSS-MA-BMAB and porogenic solvents and click reaction temperature on the morphology, permeability and column performance of the resulting POSS-BMAB hybrid monoliths were studied in detail. A uniform monolithic network with a high porosity was obtained. The POSS-BMAB hybrid monolith exhibited good permeability and high thermal and mechanical stability. A series of test compounds, including alkylbenzenes, polycyclic aromatic hydrocarbon, phenols and, anilines were used to evaluate the retention behaviors of the POSS-BMAB hybrid monolith in capillary liquid chromatography. The prepared POSS-BMAB hybrid monolith exhibited typical reversed-phase chromatographic behavior toward neutral solutes. The minimum plate height of this hybrid monolith was determined as 12.6 and 13.7 ?m for thiourea and benzene, respectively. These results demonstrate that thiol-ene click chemistry can provide a facile and robust approach for the preparation of a POSS-based hybrid monolith.
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Core-Shell Nanoparticles Based on Pullulan and Poly(?-amino) Ester for Hepatoma-Targeted Codelivery of Gene and Chemotherapy Agent.
ACS Appl Mater Interfaces
PUBLISHED: 10-27-2014
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This study designs a novel nanoparticle system with core-shell structure based on pullulan and poly(?-amino) ester (PBAE) for the hepatoma-targeted codelivery of gene and chemotherapy agent. Plasmid DNA expressing green fluorescent protein (pEGFP), as a model gene, was fully condensed with cationic PBAE to form the inner core of PBAE/pEGFP polycomplex. Methotrexate (MTX), as a model chemotherapy agent, was conjugated to pullulan by ester bond to synthesize polymeric prodrug of MTX-PL. MTX-PL was then adsorbed on the surface of PBAE/pEGFP polycomplex to form MTX-PL/PBAE/pEGFP nanoparticles with a classic core-shell structure. MTX-PL was also used as a hepatoma targeting moiety, because of its specific binding affinity for asialoglycoprotein receptor (ASGPR) overexpressed by human hepatoma HepG2 cells. MTX-PL/PBAE/pEGFP nanoparticles realized the efficient transfection of pEGFP in HepG2 cells and exhibited significant inhibitory effect on the cell proliferation. In HepG2 tumor-bearing nude mice, MTX-PL/PBAE/pEGFP nanoparticles were mainly distributed in the tumor after 24 h postintravenous injection. Altogether, this novel codelivery system with a strong hepatoma-targeting property achieved simultaneous delivery of gene and chemotherapy agent into tumor at both cellular and animal levels.
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[Ecotoxicological effect and soil environmental criteria of the heavy metal chromium(VI)].
Huan Jing Ke Xue
PUBLISHED: 10-24-2014
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Nowadays, systematic studies about water quality criteria are being carried out in China, but studies on soil environmental criteria are comparatively insufficient. In this study, germination and root growth of 8 terrestrial plants (Triticum aestivum, Lactuca sativa, Cucumis sativus, Zea mays, Brassica pekinensis, Glycine max, Allium tuberosum and Solanum lycopersicum) and growth inhibition of 1 terrestrial animal (Achatina fulica) were used to determine the chronic ecotoxicological effects of chromium (VI) using the agricultural moisture soil of Baoding. In addition, with the native toxicity data selected, the HC5 (hazardous concentration for 5% of species) and the ecological protected soil environmental criteria of chromium (VI) in Baoding moisture soil were calculated using the log-normal species sensitivity distribution (SSD) method. Results showed that the no observed effect concentration (NOEC) values for the growth of the terrestrial plants T. aestivum, L. sativa, C. sativus, Z. mays, B. pekinensis, G. max, A. tuberosum, S. lycopersicum, and the terrestrial invertebrate snail A. fulica were 19.0, 21.0, 28.0, 32.0, 28.0, 32.0, 32.0, 12.0 and 20.0 mg x kg(-1), respectively. The comparison of species toxicity data that were tested in the same conditions showed that the terrestrial plant S. lycopersicum was the most sensitive species to chromium (VI), T. aestivum and L. sativa had the same sensitivity to chromium (VI) exposure, whereas, plants C. sativus, Z. mays, B. pekinensis, G. max and A. tuberosum had the same sensitivity to chromium (VI) exposure. Finally, the HC5 value of chromium (VI) in the moisture soil of Baoding was calculated to be 7.7 (4.1 < CI < 11. 3) mg x kg(-1) using the log-normal SSD method, and the ecological protected soil environmental criteria of chromium (VI) was 1.5-7.7 mg x kg(-1). With the investigation of this work, we expect that it could provide useful information for the study of soil environmental criteria in China.
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Highly reproducible SERS arrays directly written by inkjet printing.
Nanoscale
PUBLISHED: 10-14-2014
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SERS arrays with uniform gold nanoparticle distribution were fabricated by direct-writing with an inkjet printing method. Quantitative analysis based on Raman detection was achieved with a small standard statistical deviation of less than 4% for the reproducibility and less than 5% for the long-term stability for 12 weeks.
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Investigation of circulating antibodies to ANXA1 in breast cancer.
Tumour Biol.
PUBLISHED: 10-03-2014
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Our recent work demonstrated that circulating levels of IgG antibody to linear peptide antigens derived from annexin A1 (ANXA1) were significantly increased in lung cancer. The present study was then undertaken to test whether circulating anti-ANXA1 antibodies were also altered in breast cancer. An enzyme-linked immunosorbent assay was developed in-house to determine circulating IgG against ANXA1-derived peptide antigens in 152 female patients with breast cancer and 160 female control subjects. Student's t test revealed that patients with breast cancer had significantly higher levels of anti-ANXA1 IgG than control subjects (t?=?4.75, P?
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Low-Frequency Electrical Stimulation Attenuates Muscle Atrophy in CKD-A Potential Treatment Strategy.
J. Am. Soc. Nephrol.
PUBLISHED: 09-18-2014
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Effective therapeutic strategies to treat CKD-induced muscle atrophy are urgently needed. Low-frequency electrical stimulation (LFES) may be effective in preventing muscle atrophy, because LFES is an acupuncture technique that mimics resistance exercise by inducing muscle contraction. To test this hypothesis, we treated 5/6-nephrectomized mice (CKD mice) and control mice with LFES for 15 days. LFES prevented soleus and extensor digitorum longus muscle weight loss and loss of hind-limb muscle grip in CKD mice. LFES countered the CKD-induced decline in the IGF-1 signaling pathway and led to increases in markers of protein synthesis and myogenesis and improvement in muscle protein metabolism. In control mice, we observed an acute response phase immediately after LFES, during which the expression of inflammatory cytokines (IFN-? and IL-6) increased. Expression of the M1 macrophage marker IL-1? also increased acutely, but expression of the M2 marker arginase-1 increased 2 days after initiation of LFES, paralleling the change in IGF-1. In muscle cross-sections of LFES-treated mice, arginase-1 colocalized with IGF-1. Additionally, expression of microRNA-1 and -206, which inhibits IGF-1 translation, decreased in the acute response phase after LFES and increased at a later phase. We conclude that LFES ameliorates CKD-induced skeletal muscle atrophy by upregulation of the IGF-1 signaling pathway, which improves protein metabolism and promotes myogenesis. The upregulation of IGF-1 may be mediated by decreased expression of microRNA-1 and -206 and/or activation of M2 macrophages.
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[Screening bioactive compounds inhibiting influenza virus from isatidis radix by ultrafiltration mass spectrometry].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 09-11-2014
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In vitro neuraminidase inhibition assays and ultrafiltration liquid chromatography with diodearray detector coupled to time of flight mass spectrometer (UPLC-DAD-TOF-MS) were combined to screen bioactive compounds inhibiting neuraminidase from Isatidis Radix. By comparing the compounds from Isatidis Radix before and after ultrafiltration, we found that arginine, goitrin and adenosinea can bind with neuraminidase, and the binding degree of the three compounds were (36.23 +/- 1.12)%, (32.54 +/- 1.02)% and (9.38 +/- 0.47)%, respectively. The IC50 of arginine and goitrin were (1.16 +/- 0.02), (1.20 +/- 0.02) g x L(-1), respectively. While the IC50 of adenosinea was higher than 500 g x L(-1). The results showed that arginine and goitrin might be the main compounds with antiviral activity of Isatidis Radix. This study may provide a useful method for the screening of bioactive compounds and quality control of Isatidis Radix.
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[Effect of zige lyophilized powder for injection in improving acute cerebral microcirculation disturbance in rats].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 09-11-2014
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To investigate the effect of Zige lyophilized powder for injection in improving the acute cerebral microcirculation disturbance in rats.
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The complete mitochondrial genome of the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae).
Mitochondrial DNA
PUBLISHED: 09-04-2014
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Abstract The complete mitochondrial genome (mitogenome) of Plutella xylostella (Lepidoptera: Plutellidae) was determined (GenBank accession No. KM023645). The length of this mitogenome is 16,014?bp with 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes and an A?+?T-rich region. It presents the typical gene organization and order for completely sequenced lepidopteran mitogenomes. The nucleotide composition of the genome is highly A?+?T biased, accounting for 81.48%, with a slightly positive AT skewness (0.005). All PCGs are initiated by typical ATN codons, except for the gene cox1, which uses CGA as its start codon. Some PCGs harbor TA (nad5) or incomplete termination codon T (cox1, cox2, nad2 and nad4), while others use TAA as their termination codons. The A?+?T-rich region is located between rrnS and trnM with a length of 888?bp.
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[A method of screening the antitumor lead compounds based on the dynamic bio-response profile of cells].
Yao Xue Xue Bao
PUBLISHED: 08-26-2014
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The study is to report the establishment of a method of screening the antitumor compounds based on the dynamic bio-response profile of cells to make up for the shortages of conventional end-point tests such as tedious operation and low sensitivity. Based on the principle of electric impedance of cells, the real-time cell electronic sensing (RT-CES) system was used to monitor the effect of epirubicin (EPI), cisplatinum (DDP) and carboplatin (CBP) on the growth of HepG2 cells, with the cell index (CI), half maximal inhibitory concentration (IC50) and detachment curve as evaluation indexes. Meanwhile, cell counting kit-8 (CCK-8) and microscopy were applied for verification. The results showed that CI curve could sensitively real-time profile the inhibitory effect of model drugs on HepG2 cells. The IC50 of EPI, DDP and CBP were 0.53 +/- 0.04, 9.79 +/- 0.26 and 597.00 +/- 3.79 microg x mL(-1), respectively. What's more, the significant differences of detachment curves of the three drugs indicated that their functional mechanisms might be different, this is consistent with the literature. The RT-CES system with non-invasive, label-free and real-time characteristics could be used to monitor the bio-response profile of the three drugs to HepG2 cells, allowing to qualitatively and quantitatively distinguish the antitumor activities of the three drugs, and could be a complementary method for the present screening of antitumor compounds.
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[Effects of different host plants on the cold-resistant substances in overwintering larvae of Carposina sasakii Matsumura (Lepidoptera: Carposinidae)].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 08-19-2014
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To evaluate the influence of different host plants including apple, wild jujube, jujube, pear and hawthorn on the cold-tolerance substances in overwintering larvae of the peach fruit moth Carposina sasakii Matsumura, we measured the larvae super-cooling capacity, the water content (W), total fat content (TFC), total protein content (TPC) and total glycogen content (TGC) in the body. Results showed that the mean super-cooling point (SCPs) and freezing point (FPs) of overwintering larvae from the 5 host plant fruits differed significantly, ranging from -15.53 to -8.50 degrees C and -11.31 to -4.04 degrees C, respectively. The overwintering larvae fed on hawthorn owned the highest SCP, FP, TGC and the lowest W, while those fed on apple had the lowest SCP, FP, TFC and TGC but the highest W and TPC. The fresh mass (FM) of the overwintering larvae fed on pear was the highest, while those fed on jujube was very low. Those fed on jujube accumulated the highest TFC but the lowest TPC.
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The Lewis base-catalyzed silylation of alcohols--a mechanistic analysis.
J. Org. Chem.
PUBLISHED: 08-11-2014
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Reaction rates for the base-catalyzed silylation of primary, secondary, and tertiary alcohols depend strongly on the choice of solvent and catalyst. The reactions are significantly faster in Lewis basic solvents such as dimethylformamide (DMF) compared with those in chloroform or dichloromethane (DCM). In DMF as the solvent, the reaction half-lives for the conversion of structurally similar primary, secondary, and tertiary alcohols vary in the ratio 404345:20232:1. The effects of added Lewis base catalysts such as 4-N,N-dimethylaminopyridine (DMAP) or 4-pyrrolidinopyridine (PPY) are much larger in apolar solvents than in DMF. The presence of an auxiliary base such as triethylamine is required in order to drive the reaction to full conversion.
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Incorporation of metal-organic framework HKUST-1 into porous polymer monolithic capillary columns to enhance the chromatographic separation of small molecules.
J Chromatogr A
PUBLISHED: 07-29-2014
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Metal-organic framework (MOF) HKUST-1 nanoparticles have been incorporated into poly(glycidyl methacrylate-co-ethylene dimethacrylate) (HKUST-1-poly(GMA-co-EDMA)) monoliths to afford stationary phases with enhanced chromatographic performance of small molecules in the reversed phase capillary liquid chromatography. The effect of HKUST-1 nanoparticles in the polymerization mixture on the performance of the monolithic column was explored in detail. While the bare poly(GMA-co-EDMA) monolith exhibited poor resolution (Rs<1.0) and low efficiency (800-16,300plates/m), addition of a small amount of HKUST-1 nanoparticles to the polymerization mixture provide high increased resolution (Rs?1.3) and high efficiency ranged from 16,300 to 44,300plates/m. Chromatographic performance of HKUST-1-poly(GMA-co-EDMA) monolith was demonstrated by separation of various analytes including polycyclic aromatic hydrocarbons, ethylbenzene and styrene, phenols and aromatic acids using a binary polar mobile phase (CH3CN/H2O). The HKUST-1-poly(GMA-co-EDMA) monolith displayed enhanced hydrophobic and ?-? interaction characteristics in the reversed phase separation of test analytes compared to the bare poly(GMA-co-EDMA) monolith. The experiment results showed that HKUST-1-poly(GMA-co-EDMA) monoliths are an alternative to enhance the chromatographic separation of small molecules.
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Highly-ordered perpendicularly immobilized FWCNTs on the thionine monolayer-modified electrode for hydrogen peroxide and glucose sensors.
Biosens Bioelectron
PUBLISHED: 07-26-2014
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In this paper, we innovatively immobilized few-walled carbon nanotubes (FWCNTs) perpendicularly on Au surface through conductive thionine instead of aminoalkanethiols so as to improve electrochemical properties. Because FWCNTs own smaller aggregates, stronger chemical corrosion resistant, and higher conductivity than single-walled carbon nanotubes (SWCNTs), and thionine is a good electron transfer mediator can provide amino and sulfhydryl groups playing the same function as insulating aminoalkanethiols. The strategy for obtaining perpendicularly aligned FWCNTs (p-FWCNTs) is electrostatically assembled thionine and 11-amino-n-undecanethiol (AUT) on Au surface via Au-S bond to provide amino groups for covalently combining terminus-carboxylated FWCNTs, we confirmed and compared the results by AFM, Raman spectroscopy and electrochemical methods. In order to prove the constructed basement has excellent electrochemical properties can provide a good platform for sensors fabrication, we developed a novel non-enzymatic hydrogen peroxide (H2O2) sensor by electrodepositing Pt nanoparticles (PtNPs) on p-FWCNTs/Thionine/Au electrode surface, and verified the result by TEM, EDX and electrochemical techniques. Furthermore, polyallylamine (PAA) and poly(vinyl sulfate) (PVS) permselective layer, poly(diallyldimethylammonium) (PDDA) and glucose oxidase (GOx) multilayer films were layer-by-layer self-assembled on p-FWCNTs/Thionine/Au surface to fabricate a glucose biosensor. Either the non-enzymatic H2O2 sensor or the enzyme-based glucose biosensor showed good sensitivity, selectivity, reproducibility and stability, both them had been applied for biological sample analysis with satisfactory results. The results show that the p-FWCNTs/Thionine/Au electrode can work as an ideal platform for the development of highly sensitive sensors, coupled with p-FWCNTs are rich in functional groups could be used for fabricating diverse sensors.
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Cross talk between vascular smooth muscle cells and monocytes through interleukin-1?/interleukin-18 signaling promotes vein graft thickening.
Arterioscler. Thromb. Vasc. Biol.
PUBLISHED: 07-10-2014
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Interleukin (IL)-1? and IL-18 are key proinflammatory cytokines that play important roles in the pathophysiology of vein graft remodeling. However, the mechanism of IL-1?/IL-18 production and its role in the development of graft remodeling remain unclear.
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The calculation of (29)Si NMR chemical shifts of tetracoordinated silicon compounds in the gas phase and in solution.
Phys Chem Chem Phys
PUBLISHED: 07-05-2014
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Aiming at the identification of an efficient computational protocol for the accurate NMR assessment of organosilanes in low-polarity organic solvents, (29)Si NMR chemical shifts of a selected set of such species relevant in organic synthesis have been calculated relative to tetramethylsilane (TMS, 1) using selected density functional and perturbation theory methods. Satisfactory results are obtained when using triple zeta quality basis sets such as IGLO-III. Solvent effects impact the calculated results through both, changes in substrate geometry as well as changes in the actual shieldings. Spin-orbit (SO) corrections are required for systems carrying more than one chlorine atom directly bonded to silicon. Best overall results are obtained using gas phase geometries optimized at MPW1K/6-31+G(d) level in combination with shielding calculations performed at MPW1K/IGLO-III level in the presence of the PCM continuum solvation model.
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Construction of recombinant adenovirus vector containing hBMP2 and hVEGF165 genes and its expression in rabbit Bone marrow mesenchymal stem cells.
Tissue Cell
PUBLISHED: 07-02-2014
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To construct an adenovirus vector co-expressing human bone morphogenetic protein (hBMP2) and human vascular endothelial growth factor (hVEGF165) as well as green fluorescence protein (GFP) as a marker, with which the intracellular expression of the inserted genes could be identified in Bone marrow mesenchymal stem cells (BM-MSCs). BMP2 and VEGF165 genes were PCR amplified from a cDNA library and inserted to the polyclonal site of adenovirus shuttle plasmid pAd-MCMV-GFP. The virus solution (Ad-BMP2-VEGF165) was generated by co-transfecting HEK293 cells with the constructed recombinant shuttle plasmid pAd-MCMV-BMP2-VEGF165 and adenovirus helper plasmid pBHGlox? (delta) E1, 3Cre. The virus solution was further purified and virus titer was determined accordingly. The expression of the target genes was subsequently detected and quantified in rabbit BM-MSCs by using real time PCR, ELISA and Western blotting. The recombinant adenovirus vector containing BMP2 and VEGF165 (Ad-BMP2-VEGF165) was successfully constructed, which was confirmed by Sanger sequencing, colony PCR, as well as visually detection of GFP, and the titer of the adenovirus was 1×10(10)PFU/mL, and the proteins level of BMP2 and VEGF165 secreted in the supernatant are significantly higher than the control. Recombinant adenovirus vector containing hBMP2 and hVEGF165 genes was successfully constructed. The transfection rate of BM-MSCs by the adenovirus was high (95% at 100 MOI) and the BMP2 and VEGF165 genes was highly expressed in the cells. The present study provides a method to efficiently express the target genes in BM-MSCs and an vector for further research of bone defect repair using dual genes of BMP2 and VEGF165.
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Dynamic monitoring of the cytotoxic effects of protoberberine alkaloids from Rhizoma Coptidis on HepG2 cells using the xCELLigence system.
Chin J Nat Med
PUBLISHED: 06-28-2014
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To investigate the cytotoxic effects of the six protoberberine alkaloids (PAs) from Rhizoma Coptidis on HepG2 cells.
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RNA interference-mediated knockdown of long-form phosphodiesterase-4D (PDE4D) enzyme reverses amyloid-?42-induced memory deficits in mice.
J. Alzheimers Dis.
PUBLISHED: 06-28-2014
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Phosphodiesterase-4 (PDE4) inhibitors enhance memory, increase hippocampal neurogenesis, and reverse amyloid-? (A?)-induced memory deficits. Here, we examined whether long-form PDE4D knockdown by lentiviral RNA construct containing a specific microRNA/miRNA-mir hairpin structure (4DmiRNA) reversed memory impairment caused by amyloid-?1-42 (A?42) in mice using the Morris water maze (MWM) and novelty object recognition tests. Western blotting analysis was used to assess protein levels of cAMP response element-binding protein (CREB, unphosphorylated and phosphorylated [pCREB]), brain-derived neurotrophic factor (BDNF), interleukin-1? (IL-1?), tumor necrosis factor-? (TNF-?), and nuclear factor-?B (NF-?B) to explore the neurochemical mechanisms. Aggregated A?42 (0.5 ?g/side) bilaterally infused in dentate gyrus decreased cAMP levels (p < 0.01) and produced memory deficits in the MWM (p < 0.01) and object recognition tests (p < 0.01). Microinfusions of lentiviruses resulted in downregulated expression of PDE4D4 and 4D5 proteins and reversed A?42-induced cAMP decline (p < 0.05) and memory deficits. Treatment also concomitantly increased pCREB (p < 0.05) and BDNF (p < 0.01) and reduced IL-1? (p < 0.05), TNF-? (p < 0.01), and NF-?B (p65) (p < 0.05) in the hippocampus of A?42-challenged mice. These results suggest that long-form PDE4D knockdown may offer a promising treatment for memory loss associated with Alzheimer's disease.
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[A novel method for testing sterility of injections based on biothermodynamics].
Yao Xue Xue Bao
PUBLISHED: 06-26-2014
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This study aims at trying to establish a novel method of sterility test for injections based on biothermodynamics, in order to overcome the deficiencies of routine sterility tests such as long detecting cycle, low sensitivity and prone to misjudgments. A biothermodynamics method was adopted to rapidly detect the microorganism contamination of injections by monitoring the heat metabolism during the growth of microbe. The growth rate equal to or greater than zero and the heat power difference of P(i) and P(0) with three folds higher than the noise of baseline were chosen as indexes to study the heat change rule of microbe. In this way, the effectiveness of the new method to detect strains required by conventional sterility test or in injection samples was also investigated. Results showed that the Gram-positive bacteria, Gram-negative bacteria and fungi demanded by sterility testing methodology could be detected by biothermodynamics method within 10 hours, with the sensitivity lower than 100 CFU x mL(-1). Meanwhile, this method was successfully applied to the sterility test of Compound Yinchen injection (FFYC), Shuanghuanglian powder injection (SHL) and Compound Triamcinolone injection (TAND) which were sterilized with different degrees. Therefore, the biothermodynamics method, with advantages of fast detection and high sensitivity, could be a complementary solution for conventional sterility tests.
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Intravitreal ranibizumab therapy versus photodynamic therapy for idiopathic choroidal neovascularization: a comparative study on visual acuity, retinal and choroidal thickness.
Chin. Med. J.
PUBLISHED: 06-17-2014
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Photodynamic therapy (PDT) has been recommended as a main treatment for idiopathic choroidal neovascularization (I-CNV). But the visual results of PDT were inconsistent and variable, and PDT may bring severe damage to the retinal pigment epithelium and choriocapillaries. In recent years, intravitreal ranibizumab therapy, showing favorable visual outcomes, has developed as an advanced treatment for choroidal neovascularization (CNV). Although both methods have been reported to be effective in treating I-CNV, there is no detailed comparative report between the two methods. This study aimed to compare visual outcomes, retinal and choroidal thickness between intravitreal ranibizumab therapy and PDT in the treatment of I-CNV, and investigate the correlation of visual outcomes with retinal and choroidal thickness in each of the two groups.
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Preparation and mechanism insight of nuclear envelope-like polymer vesicles for facile loading of biomacromolecules and enhanced biocatalytic activity.
ACS Nano
PUBLISHED: 06-17-2014
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The facile loading of sensitive and fragile biomacromolecules, such as glucose oxidase, hemoglobin, and ribonucleic acid (RNA), via synthetic vehicles directly in pure aqueous media is an important technical challenge. Inspired by the nucleus pore complex that connects the cell nucleus and the cytoplasm across the nuclear envelope, here we describe the development of a kind of polymeric nuclear envelope-like vesicle (NEV) to address this problem. The NEV is tailored to form the polymer pore complex (70 nm, similar to a nucleus pore complex) within the vesicle membrane based on nanophase segregation, which is confirmed via fluorescence spectrometry and dynamic light scattering (DLS) during self-assembly. This pH-triggered polymer pore complex can mediate the transportation of biomacromolecules across the vesicle membrane. Moreover, the NEVs facilitate the natural consecutive enzyme-catalyzed reactions via the H(+) sponge effect. This simple strategy might also be extended for mimicking other synthetic cell organelles.
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Expression and localization of transcription factors SNAIL and SLUG in mouse ovaries and pre-implantation embryos.
Cell Tissue Res.
PUBLISHED: 06-15-2014
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SNAIL and SLUG are zinc-finger transcription factors that participate in the regulation of cell division, cell survival, mesoderm formation and epithelial-to-mesenchymal transition. We investigate the expression of SNAIL and SLUG during follicular maturation, ovulation and luteinization in the ovaries of both neonatal mice and gonadotropin-induced immature mice. Furthermore, we examine the expression and localization of these transcription factors during early embryonic cleavage. Our data demonstrate that both SNAIL and SLUG are present in the epithelial cells of the ovarian surface in immature mice. SNAIL is first evident in the interstitial cells and theca cells by postnatal day (PD) 6 and then appears in the oocytes by PD 8, remaining at a constant expression level for all stages studied thereafter. SLUG is expressed in oocytes as early as PD 1. Its expression also increases with the development of the follicles in theca and interstitial cells but not in granulosa cells. In gonadotropin-induced immature mice, both SNAIL and SLUG are expressed in the corpora lutea. During early embryo cleavage, SNAIL occurs in the nucleus and cytoplasm of the majority of the embryo, excluding the nucleolus from the germinal vesicle breakdown (GVBD) to the 8-cell stage and is then localized in the cytoplasm during the morula stage and in the nucleus during the blastocyst stage. SLUG has an identical expression pattern as SNAIL from GVBD until the morula stage, except that it is localized in the cytoplasm during the blastocyst stage. Taken together, these different localization patterns suggest that SNAIL and SLUG probably play important roles during follicular development, luteinization and early embryonic development.
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Novel outer membrane protein involved in cellulose and cellooligosaccharide degradation by Cytophaga hutchinsonii.
Appl. Environ. Microbiol.
PUBLISHED: 05-20-2014
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Cytophaga hutchinsonii is an aerobic cellulolytic soil bacterium which was reported to use a novel contact-dependent strategy to degrade cellulose. It was speculated that cellooligosaccharides were transported into the periplasm for further digestion. In this study, we reported that most of the endoglucanase and -glucosidase activity was distributed on the cell surface of C. hutchinsonii.Cellobiose and part of the cellulose could be hydrolyzed to glucose on the cell surface. However, the cell surface cellulolytic enzymes were not sufficient for cellulose degradation by C. hutchinsonii. An outer membrane protein, CHU_1277, was disrupted by insertional mutation. Although the mutant maintained the same endoglucanase activity and most of the -glucosidase activity,it failed to digest cellulose, and its cellooligosaccharide utilization ability was significantly reduced, suggesting that CHU_1277 was essential for cellulose degradation and played an important role in cellooligosaccharide utilization. Further study of cellobiose hydrolytic ability of the mutant on the enzymatic level showed that the -glucosidase activity in the outer membrane of the mutant was not changed. It revealed that CHU_1277 played an important role in assisting cell surface -glucosidase to exhibit its activity sufficiently. Studies on the outer membrane proteins involved in cellulose and cellooligosaccharide utilization could shed light on the mechanism of cellulose degradation by C. hutchinsonii.
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[Application of high-content screening and flow cytometry analysis techniques to evaluation of myocardial fibroblasts proliferation].
Sheng Li Xue Bao
PUBLISHED: 04-30-2014
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The proliferation of cardiac fibroblasts (CFs) is a key pathological process in the cardiac remodeling. To establish an objective, quantitative method for the analysis of cell proliferation and cell cycle, we applied the high-content screening (HCS) and flow cytometry (FCM) techniques. CFs, isolated by enzyme digestion from newborn C57BL/6J mice, were serum starved for 12 h and then given 10% fetal bovine serum (FBS) for 24 h. Followed by BrdU and DAPI (or 7-AAD) staining, CFs proliferation and cell cycle were analyzed by HCS and FCM, respectively. Discoidin domain receptor 2 (DDR2) staining indicated that the purity of isolated CFs was over 95%. (1) HCS analysis showed that the ratio of BrdU-positive cells was significantly increased in 10% FBS treated group compared with that in serum-free control group [(12.96 ± 0.67)% vs (2.77 ± 0.33)%; P < 0.05]. Cell cycle analysis showed that CFs in G0/G1 phase were diploid, and CFs in S phase were companied with proliferation, DNA replication and enlarged nuclei; CFs in G2 phase were tetraploid, and CFs in M phase produced two identical cells (2N). (2) FCM analysis showed that the ratio of BrdU-positive cells was increased in 10% FBS treated group compared with that in the control group [(11.10 ± 0.42)% vs (2.22 ± 0.31)%; P < 0.05]; DNA content histogram of cell cycle analysis indicated that the platform of S phase elevated in 10% FBS group compared with control group. (3) There were no differences between the two methods in the results of proliferation and cell cycle analysis. In conclusion, HCS and FCM methods are reliable, stable and consistent in assessment of the proliferation and cell cycle in CFs.
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Arsenic downregulates gene expression at the postsynaptic density in mouse cerebellum, including genes responsible for long-term potentiation and depression.
Toxicol. Lett.
PUBLISHED: 04-23-2014
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Arsenic (As) is a neurotoxin induces dysfunction of learning and memory. Research has indicated that cerebellum may be involved in arsenic-induced impairment of learning and memory. However, the molecular mechanisms that underlie these effects remain unclear. This study screened for the differentially expressed genes related to the long-term potentiation and long-term depression (LTP and LTD) at the cerebellar postsynaptic density (PSD) of mice following exposure to arsenic, and we provide evidence of the mechanism by which arsenic adversely affects the functions of learning and memory. Here, SPF mice were exposed to 1ppm, 2ppm and 4ppm As2O3 for 60 days. The ultrastructure of the synapses in cerebella of these mice was observed via transmission electron microscopy. The cerebellum global gene expression of mice exposed to 4ppm As2O3 was determined through GeneChip analysis. We used the web tool DAVID to analyze the Gene Ontology (GO) and KEGG pathways that were signi?cantly enriched among the differentially expressed genes. Our observations of synaptic ultrastructure showed that the thickness of the cerebellar PSD was reduced in mice exposed to arsenic. Go analysis revealed the PSD as a significantly altered cellular component. KEGG pathway analysis showed that LTP and LTD were affected by arsenic with highest statistical significance, and 20 differentially expressed genes were associated with them. Among these differentially expressed genes, significant decreases in the mRNA expressions of CaMKII, Gria1, Gria2, Grin1, Itpr1, Grm1 and PLC?4 related to the LTP and LTD were found at the PSD of mouse cerebellum exposed to arsenic. The downregulation of these genes was further confirmed via real-time reverse transcription PCR or Western blot at 1ppm, 2ppm and 4ppm As2O3. Our results indicate that the 7 genes with in cerebellar PSDs may be involved in arsenic-induced neurotoxicity, including impairment of learning and memory.
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Effect of Morinda officinalis capsule on osteoporosis in ovariectomized rats.
Chin J Nat Med
PUBLISHED: 04-08-2014
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To explore the therapeutic effects of Morinda officinalis capsules (MOP) on osteoporosis in ovariectomized rats.
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Expression of breast cancer resistance protein in peripheral T cell subsets from HIV?1?infected patients with antiretroviral therapy.
Mol Med Rep
PUBLISHED: 04-07-2014
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The aim of the present study was to investigate the expression of breast cancer resistance protein (BCRP) in peripheral T cell subsets of human immunodeficiency virus 1 (HIV?1)?infected patients, and to analyze the association between the levels of BCRP expression and disease progression in HIV?1 infection. Peripheral blood mononuclear cells (PBMCs) were obtained from HIV?1?infected patients (n=118), including 92 patients with antiretroviral therapy (ART) and 26 patients without a history of ART. Control samples from 30 healthy donors were also analyzed. The expression levels of BCRP in T cells were evaluated by flow cytometry. A high inter?individual variability was observed in CD4+ and CD8+ T cells in the HIV?1?infected patients and healthy donors; however, the analyzed expression levels of BCRP were significantly higher in the HIV?1?infected group with ART than those in the group with no history of ART (P<0.01). Furthermore, the frequency of BCRP?expressing T cells was inversely correlated with CD4+ and CD8+ T cell counts in HIV?1?infected patients with ART. The results suggested that BCRP expression varied among HIV?1?infected patients and healthy donors but was significantly higher in HIV?1 patients undergoing ART. In conclusion, the present study suggested that overexpression of BCRP may be involved in disease progression of the HIV?1 infection and may participate in drug resistance to ART, thus contributing to the failure of highly active ART in HIV?1 therapeutics.
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Collision dynamics of proton with formaldehyde: fragmentation and ionization.
J Chem Phys
PUBLISHED: 04-05-2014
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Using time-dependent density functional theory, applied to the valence electrons and coupled non-adiabatically to molecular dynamics of the ions, we study the ionization and fragmentation of formaldehyde in collision with a proton. Four different impact energies: 35 eV, 85 eV, 135 eV, and 300 eV are chosen in order to study the energy effect in the low energy region, and ten different incident orientations at 85 eV are considered for investigating the steric effect. Fragmentation ratios, single, double, and total electron ionization cross sections are calculated. For large impact parameters, these results are close to zero irrespective of the incident orientations due to a weak projectile-target interaction. For small impact parameters, the results strongly depend on the collision energy and orientation. We also give the kinetic energy releases and scattering angles of protons, as well as the cross section of different ion fragments and the corresponding reaction channels.
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Effects of normal aging on myelin sheath ultrastructures in the somatic sensorimotor system of rats.
Mol Med Rep
PUBLISHED: 04-01-2014
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Previous studies have presented qualitative and quantitative data regarding the morphological changes that occur peripherally in myelin sheaths and nerve fibers of rats during their lifespan. However, studies on ultrastructural features of myelinated fibers (MFs) in the central nervous system (CNS) remain limited. In the present study, morphological analyses of the somatic sensorimotor MFs in rats at time?points between postnatal day 14 and postnatal month (PNM) 26 were conducted using electron microscopy. Significant alterations in the myelin sheath were observed in the sensorimotor system of aging and aged rats, which became aggravated with age. The ultrastructural pattern of myelin lamellae also exhibited age dependence. The transformation of the myelin intraperiod line from complete to incomplete fusion occurred after PNM 5, leading to an expansion of periodicity in myelin lamellae. These pathological changes in the myelin structure occurred very early and showed a significant correlation with age, indicating that myelin was the part of the CNS with the highest susceptibility to the influence of aging, and may be the main target of aging effects. In addition to the myelin breakdown, continued myelin production and remyelination were observed in the aging sensorimotor system, suggesting the presence of endogenous mechanisms of myelin repair.
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Gene profiling in the dynamic regulation of the lifespan of the myelin sheath structure in the optic nerve of rats.
Mol Med Rep
PUBLISHED: 04-01-2014
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Aging of the nervous system leads to impairments in cognition and motor skills, and is a major risk factor for several neurological disorders. Recently, numerous nerve function deficits that appear with aging have been found to be a consequence of myelin abnormalities; however, the genetic mechanism of the age?related alterations in the myelin sheath has not yet been fully elucidated. In the present study, the morphology of the myelin sheath in the optic nerve of rats was analyzed at 10 time?points throughout life. Marked alterations in the myelin sheath were observed in aging and aged optic nerves, and these became progressively more severe with time. To determine the biological processes affected by aging in the myelin sheath, the age?related profiling of the myelin sheath in rat optic nerves was established using microarray hybridization at 10 time?points throughout life, between birth and senescence. From the results, 3,826 transcripts associated with the age?related alterations in the myelin sheath of the optic nerve were identified. It was found that the biological processes most significantly altered by aging were lipid metabolism, the immune response and transmitter transport. This suggests that the downregulation of lipid synthesis genes and the upregulation of immune and neurotransmitter transport genes in aging may be the genetic basis for the age?related alterations observed in the myelin sheath.
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Screening for metastatic osteosarcoma biomarkers with a DNA microarray.
Asian Pac. J. Cancer Prev.
PUBLISHED: 03-20-2014
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The aim of this study was to screen for possible biomarkers of metastatic osteosarcoma (OS) using a DNA microarray.
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Comparison of reversed-phase liquid chromatography and hydrophilic interaction chromatography for the fingerprint analysis of Radix isatidis.
J Sep Sci
PUBLISHED: 02-21-2014
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Radix isatidis is a famous anti-influenza virus herbal medicine traditionally taken as a water decoction. However, the chemical fingerprint analysis of Radix isatidis is dominantly based on RPLC, from which it is difficult to obtain fingerprint information of hydrophilic compounds. Here, we developed the separation of Radix isatidis by RPLC and hydrophilic interaction chromatography, comparing the traditional RPLC fingerprint with the hydrophilic interaction chromatography fingerprint. Besides, an anti-viral assay of Radix isatidis was conducted to evaluate its efficacy. The fingerprint-efficacy relationships between the fingerprints and the anti-viral activity were further investigated with principal component regression analysis. The results showed that the anti-viral activity correlated better with the hydrophilic interaction chromatography fingerprint than with the RPLC fingerprint. This study indicates that hydrophilic interaction chromatography could not only be a complementary method to increase the fingerprint coverage of conventional RPLC fingerprint, but also can better represent the efficacy and quality of Radix isatidis.
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Theoretical study on collision dynamics of H(+) + CH4 at low energies.
J Chem Phys
PUBLISHED: 02-12-2014
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In this work we make an investigation on collision dynamics of H(+) + CH4 at 30 eV by using time-dependent density functional theory coupled with molecular dynamics approach. All possible reactions are presented based on 9 incident orientations. The calculated fragment intensity is in nice agreement with experimental results. The mechanism of reaction transition for dissociation and proton exchange processes is explained by the intra-molecule energy transfer. However, the energy loss of the proton is in poor agreement with experimental results. The discrepancy is attributed to the mean-field treatment of potential surface. We also studied the dependence on initial velocity of both proton and methane. In addition, we find that for dynamical evolution a different self-interaction correction (SIC) may lead to different results, but with respect to the position of rainbow angle, average-density SIC seems to have reasonable correction.
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The effects of electron transfer on the energy loss of slow He²?, C²?, and C?? ions penetrating a graphene fragment.
J Phys Condens Matter
PUBLISHED: 02-07-2014
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Electronic energy loss in the collision processes of slow ions with a graphene fragment is investigated by combining ab initio time-dependent density functional theory calculations for electrons with molecular dynamics simulations for ions in real time and real space. We study the electronic energy loss of slow He²?, C²?, and C?? ions penetrating the graphene fragment as a function of the ion velocity, and establish the velocity-proportional energy loss for low-charged ions down to 0.1 a.u. One mechanism clarified in the simulations for electron transfer is polarization capture, which is effective for bare ions at low velocities. The other one is resonance capture, by which the incident ion can capture electrons from the graphene fragment to its electron affinity levels, which have the same, or nearly the same, energy as those of the electron donor levels. The results demonstrate that the nonlinear behavior of energy loss of C?? is attributed to the large number of electrons captured by this multi-charged ion during the collision.
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A general strategy for assembling nanoparticles in one dimension.
Adv. Mater. Weinheim
PUBLISHED: 01-22-2014
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Alignment of 1D assemblies of a wide variety of nanoparticles (e.g., metal, metal oxide, semiconductor quantum dots, or organic microspheres) in one direction upon diverse substrates (including industrial silicon wafers and transparent glass plates) by a general strategy is demonstrated. This sandwich method provides an efficient way of rapidly and precisely assembling nanoparticles on a large scale (up to 10 cm × 10 cm) for device applications.
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Efficient synthesis of narrowly dispersed hydrophilic and magnetic molecularly imprinted polymer microspheres with excellent molecular recognition ability in a real biological sample.
Chem. Commun. (Camb.)
PUBLISHED: 01-16-2014
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A facile and highly efficient approach to obtain narrowly dispersed hydrophilic and magnetic molecularly imprinted polymer microspheres with molecular recognition ability in a real biological sample as good as what they show in the organic solvent-based media is described for the first time.
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Characterization of a multi-function processive endoglucanase CHU_2103 from Cytophaga hutchinsonii.
Appl. Microbiol. Biotechnol.
PUBLISHED: 01-12-2014
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Cytophaga hutchinsonii is a Gram-negative gliding bacterium which can efficiently degrade crystalline cellulose by an unknown strategy. Genomic analysis suggests the C. hutchinsonii genome lacks homologs to an obvious exoglucanase that previously seemed essential for cellulose degradation. One of the putative endoglucanases, CHU_2103, was successfully expressed in Escherichia coli JM109 and identified as a processive endoglucanase with transglycosylation activity. It could hydrolyze carboxymethyl cellulose (CMC) into cellodextrins and rapidly decrease the viscosity of CMC. When regenerated amorphous cellulose (RAC) was degraded by CHU_2103, the ratio of the soluble to insoluble reducing sugars was 3.72 after 3 h with cellobiose and cellotriose as the main products, indicating that CHU_2103 was a processive endoglucanase. CHU_2103 could degrade cellodextrins of degree of polymerization ?3. It hydrolyzed p-nitrophenyl ?-D-cellodextrins by cutting glucose or cellobiose from the non-reducing end. Meanwhile, some larger-molecular-weight cellodextrins could be detected, indicating it also had transglycosylation activity. Without carbohydrate-binding module (CBM), CHU_2103 could bind to crystalline cellulose and acted processively on it. Site-directed mutation of CHU_2103 demonstrated that the conserved aromatic amino acid W197 in the catalytic domain was essential not only for its processive activity, but also its cellulose binding ability.
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Apelin-13 protects the brain against ischemia/reperfusion injury through activating PI3K/Akt and ERK1/2 signaling pathways.
Neurosci. Lett.
PUBLISHED: 01-06-2014
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Apelin has been proved to protect the heart against ischemia/reperfusion (I/R) injury via the activation of phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) signaling pathways. Whether this protective effect applies to brain I/R injury needed to be explored. We therefore investigated the potential neuroprotective role of Apelin-13 and the underlying mechanisms. Focal transient cerebral I/R model in male ICR mice was induced by 60min of ischemia followed by reperfusion. Apelin-13 intracerebroventricular injection was performed 15 min before reperfusion. Neurological function, infarct volume, brain edema and apoptosis were measured at 24h after stroke. To further test the mechanism of Apelin-13, PI3K inhibitor LY294002 and ERK1/2 inhibitor PD98059 were injected into the lateral cerebral ventricle 15min before ischemia. Compared with the Vehicle group, Apelin-13 significantly ameliorated neurological deficit, infarct volume, brain edema and reduced TUNEL-positive cells. Bax, caspase-3 and cleaved caspase-3 were down-regulated and Bcl-2 up-regulated. While, the effect of Apelin-13 on Bax, Bcl-2, caspase-3 and cleaved caspase-3 was attenuated by LY294002 and PD98059. Apelin protected the brain against I/R insult injury, and this effect may be through activation of PI3K/Akt and ERK1/2 signaling pathways.
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Assessment of toxic effects of triclosan on the terrestrial snail (Achatina fulica).
Chemosphere
PUBLISHED: 01-05-2014
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Triclosan (TCS) is a broad-spectrum antimicrobial agent used in personal care products, and as a result, is widespread in the environment. Toxicity tests of TCS on aquatic organisms have been reported, but limited toxicity data on terrestrial species are available. In this study, the 28-d chronic toxicity of TCS on the biomass, shell diameter growth, and total food intake of the terrestrial snail Achatina fulica were tested. Moreover, biochemical responses, including changes in the activity of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and the content of malondialdehyde (MDA), were examined after 14-d and 28-d exposure. Results showed that TCS had toxic effects on the biomass, shell diameter growth, and total food intake of A. fulica with no observed effect concentration (NOEC) values of 24 mg kg(-1). As for the antioxidant enzymes, TCS caused significant oxidative stress even at the low concentration of 24 mg kg(-1). The CAT and POD activities at the high concentrations of 200 and 340 mg kg(-1), respectively, were significantly inhibited. The SOD and CAT activity in treatments below 118 mg kg(-1) and the MDA content in all treatments showed dose-effect relationships. This study demonstrated that TCS caused adverse effects on terrestrial invertebrates, and provided valuable information for the risk assessment imposed by TCS in the terrestrial environment.
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Increased p16 DNA methylation in mouse thymic lymphoma induced by irradiation.
PLoS ONE
PUBLISHED: 01-01-2014
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DNA methylation is an important part of epigenetics. In this study, we examined the methylation state of two CpG islands in the promoter of the p16 gene in radiation-induced thymic lymphoma samples. The mRNA and protein levels of P16 were significantly reduced in radiation-induced thymic lymphoma tissue samples. Twenty-three CpG sites of the CpG islands in the p16 promoter region were detected, and the methylation percentages of -71, -63, -239, -29, -38, -40, -23, 46 CpG sites were significantly higher in radiation-induced thymic lymphoma tissue samples than those in matched non-irradiated thymus tissue samples. This study provides new evidence for the methylation state of p16 in the radiation-induced thymic lymphoma samples, which suggests that the methylation of these CpG sites in the p16 promoter may reduce its expression in the thymic lymphoma after irradiation.
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Clinical study of the hypothesis of endogenous collateral wind on acute coronary syndrome: a review.
Afr J Tradit Complement Altern Med
PUBLISHED: 01-01-2014
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Acute Coronary Syndrome (ACS), is a serious threat to people's health, and life, and in recent years, the incidence has increased yearly. This study was to propose the hypothesis of "endogenous collateral wind" based on the patho-mechanism of thrombogenesis complicated by ruptured plaque on ACS, and the theory of traditional Chinese medicine.
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Nanostructured lipid carriers as a novel oral delivery system for triptolide: induced changes in pharmacokinetics profile associated with reduced toxicity in male rats.
Int J Nanomedicine
PUBLISHED: 01-01-2014
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After oral administration in rodents, triptolide (TP), a diterpenoid triepoxide compound, active as anti-inflammatory, immunosuppressive, anti-fertility, anti-cystogenesis, and anticancer agent, is rapidly absorbed into the blood circulation (from 5.0 to 19.5 minutes after dosing, depending on the rodent species) followed by a short elimination half-life (from about 20 minutes to less than 1 hour). Such significant and rapid fluctuations of TP in plasma likely contribute to its toxicity, which is characterized by injury to hepatic, renal, digestive, reproductive, and hematological systems. With the aim of prolonging drug release and improving its safety, TP-loaded nanostructured lipid carriers (TP-NLCs), composed of Compritol® 888 ATO (solid lipid) and Capryol™ 90 (liquid lipid), were developed using a microemulsion technique. The formulated TP-NLCs were also characterized and in vitro release was evaluated using the dialysis bag diffusion technique. In addition, the pharmacokinetics and toxicology profiles of TP-NLCs were compared to free TP and TP-loaded solid lipid nanoparticles (TP-SLNs; containing Compritol 888 ATO only). Results demonstrate that TP-NLCs had mean particle size of 231.8 nm, increased drug encapsulation with a 71.6% efficiency, and stable drug incorporation for over 1-month. TP-NLCs manifested a better in vitro sustained-release pattern compared to TP-SLNs. Furthermore, TP-NLCs prolonged mean residence time (MRT)0-t (P<0.001, P<0.001), delayed Tmax (P<0.01, P<0.05) and decreased Cmax (P<0.01, P<0.05) compared to free TP and TP-SLNs, respectively, which was associated with reduced subacute toxicity in male rats. In conclusion, our data suggest that TP-NLCs are superior to TP-SLNs and could be a promising oral delivery system for a safer use of TP.
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Dynamic behavior of positive solutions for a leslie predator-prey system with mutual interference and feedback controls.
ScientificWorldJournal
PUBLISHED: 01-01-2014
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We consider a Leslie predator-prey system with mutual interference and feedback controls. For general nonautonomous case, by using differential inequality theory and constructing a suitable Lyapunov functional, we obtain some sufficient conditions which guarantee the permanence and the global attractivity of the system. For the periodic case, we obtain some sufficient conditions which guarantee the existence, uniqueness, and stability of a positive periodic solution.
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Inhibition of Toll-like receptor 2 reduces cardiac fibrosis by attenuating macrophage-mediated inflammation.
Cardiovasc. Res.
PUBLISHED: 11-20-2013
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Toll-like receptor 2 (TLR2) is an important player in innate immunity, and recent studies have identified TLR2 as a critical mediator in cardiovascular diseases. Here, we investigated the involvement of TLR2 in angiotensin (Ang) II-induced cardiac fibrosis and the underlying mechanisms.
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Obesity occurring in apolipoprotein E-knockout mice has mild effects on fertility.
Reproduction
PUBLISHED: 11-08-2013
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The Apolipoprotein (Apo) family is implicated in lipid metabolism. There are five types of Apo: Apoa, Apob, Apoc, Apod, and Apoe. Apoe has been demonstrated to play a central role in lipoprotein metabolism and to be essential for efficient receptor-mediated plasma clearance of chylomicron remnants and VLDL remnant particles by the liver. Apoe-deficient (Apoe(-/-)) mice develop atherosclerotic plaques spontaneously, followed by obesity. In this study, we investigated whether lipid deposition caused by Apoe knockout affects reproduction in female mice. The results demonstrated that Apoe(-/-) mice were severely hypercholesterolemic, with their cholesterol metabolism disordered, and lipid accumulating in the ovaries causing the ovaries to be heavier compared with the WT counterparts. In addition, estrogen and progesterone decreased significantly at D 100. Quantitative PCR analysis demonstrated that at D 100 the expression of cytochromeP450 aromatase (Cyp19a1), 3?-hydroxysteroid dehydrogenase (Hsd3b), mechanistic target of rapamycin (Mtor), and nuclear factor-?B (Nfkb) decreased significantly, while that of BCL2-associated agonist of cell death (Bad) and tuberous sclerosis complex 2 (Tsc2) increased significantly in the Apoe(-/-) mice. However, there was no difference in the fertility rates of the Apoe(-/-) and WT mice; that is, obesity induced by Apoe knockout has no significant effect on reproduction. However, the deletion of Apoe increased the number of ovarian follicles and the ratio of ovarian follicle atresia and apoptosis. We believe that this work will augment our understanding of the role of Apoe in reproduction.
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Aging increases CCN1 expression leading to muscle senescence.
Am. J. Physiol., Cell Physiol.
PUBLISHED: 11-06-2013
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Using microarray analysis, we found that aging sarcopenia is associated with a sharp increase in the mRNA of the matricellular protein CCN1 (Cyr61/CTGF/Nov). CCN1 mRNA was upregulated 113-fold in muscle of aged vs. young rats. CCN1 protein was increased in aging muscle in both rats (2.8-fold) and mice (3.8-fold). When muscle progenitor cells (MPCs) were treated with recombinant CCN1, cell proliferation was decreased but there was no change in the myogenic marker myoD. However, the CCN1-treated MPCs did express a senescence marker (SA-?gal). Interestingly, we found CCN1 increased p53, p16(Ink4A), and pRP (hypophosphorylated retinoblastoma protein) protein levels, all of which can arrest cell growth in MPCs. When MPCs were treated with aged rodent serum CCN1 mRNA increased by sevenfold and protein increased by threefold suggesting the presence of a circulating regulator. Therefore, we looked for a circulating regulator. Wnt-3a, a stimulator of CCN1 expression, was increased in serum from elderly humans (2.6-fold) and aged rodents (2.0-fold) compared with young controls. We transduced C2C12 myoblasts with wnt-3a and found that CCN1 protein was increased in a time- and dose-dependent manner. We conclude that in aging muscle, the circulating factor wnt-3a acts to increase CCN1 expression, prompting muscle senescence by activating cell arrest proteins.
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The radiosensitizing effect of Paeonol on lung adenocarcinoma by augmentation of radiation-induced apoptosis and inhibition of the PI3K/Akt pathway.
Int. J. Radiat. Biol.
PUBLISHED: 10-25-2013
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Abstract Purpose: To investigate the radiosensitizing effect and mechanism of action by the natural product Paeonol on lung adenocarcinoma both in vitro and in vivo. Materials and methods: Two lung adenocarcinoma cell lines (human lung adenocarcinoma cell line A549 and mouse Lewis lung carcinoma (LLC) cell line) were chosen for this research. In order to select the experimental concentrations of Paeonol, cytotoxicity was determined using a MTT (3-[4,5-dimethylthiazol-2-yl]-2,5- diphenyltetrazolium bromide) assay. A clonogenic assay was performed to measure the radiosensitizing effects. Apoptosis was determined by the Tunel (terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling) assay and flow cytometry. Protein expression was analyzed by Western blotting. To test the radiosensitizing effect in vivo, a transplanted tumor model was established. Results: The MTT assay showed that Paeonol inhibited proliferation of cells. Paeonol concentration ranged from an IC5 (5% inhibiting concentration) to an IC20 and was used at non-toxic concentrations for subsequent experiments. The clonogenic assay showed that Paeonol enhanced the radiosensitivity of cells. Data from the Tunel assay and flow cytometry verified that Paeonol enhanced radiation-induced apoptosis. Paeonol inhibited the activation of the PI3K/AKT (Phosphatidylinositol 3-kinase/ Protein Kinase B) pathway and down-regulated the expression of COX-2 (Cyclooxygenase-2) and Survivin. Paeonol (1718 mg/kg) combined with 10 Gy irradiation inhibited the growth of a transplanted tumor model in vivo, resulting in the longest tumor growth time, tumor growth delay and the highest inhibition ratio when compared with the radiotherapy alone group. Conclusions: It is reported for the first time that Paeonol has a radiosensitizing effect on lung adenocarcinoma both in vitro and in vivo. This effect could be related to the augmentation of radiation-induced apoptosis and the inhibition of the PI3K/Akt signalling pathway and its downstream proteins: COX-2 and Survivin.
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Severe vitamin D-deficiency and increased bone turnover in patients with hepatitis B from northeastern China.
Endocr. Res.
PUBLISHED: 10-01-2013
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Vitamin D plays a key role in maintaining calcium homeostasis and skeletal health. The liver is critically involved in vitamin D metabolism, as 25-hydroxyvitamin D? (25(OH)D?) is synthesized in the liver. Therefore liver dysfunction may lead to vitamin D deficiency and bone problems. The aim of this study was to examine vitamin D status and bone turnover markers in hepatitis B patients from northeastern China.
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[Cell membrane chromatography and its application progress in studies of traditional Chinese medicines].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 09-27-2013
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As a novel bioaffinity chromatography technique, cell membrane chromatography (CMC) was first established by Professor He in 1996, with which combined high performance liquid chromatography, cytobiology, and receptor pharmacology. The cell membrane stationary phase (CMSP) consists of porous silica coated with active cell membranes. By immersing silica into a suspension of cell membranes, the whole surface of silica was covered by the cell membranes. In CMC, the interaction of drugs or compounds with the immobilized cell membrane or its receptors is investigated using liquid chromatography. In general, with the aim to provide scientific foundation for further development and application, this paper mainly focuses on the characteristics of the cell membrane stationary phase (CMSP), the CMC analytical system, and its applications in traditional Chinese medicines (TCMs) about CMC. With the development of CMC, the breakthrough progress of it in studying active components of TCMs field is expectant.
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Progesterone is critical for the development of mouse embryos.
Endocrine
PUBLISHED: 09-23-2013
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Infertility affects approximately 10-15 % of reproductive-aged couples, and embryo loss due to preimplantation death is common to many mammals. Previous studies showed that a complex series of interactive molecular events are associated with this process, especially hormones (progesterone and estrogens) and growth factors, and are important for the cleavage and differentiation of the blastocysts. Yet, the mechanism of preimplantation embryo development is unclear. Using conditional knockout mice (CKO), we showed the development of blastocyst is tightly controlled by the level of progesterone (P4); furthermore, we found that the time when P4 should increase is also crucial for the formation of blastocysts. In CKO mice whose Lrh1 (liver receptor homolog 1) is deleted under the expression of Cre recombinase driven by progesterone receptor promoter, which reduced P4 synthesis, few of their embryos can reach blastocyst stage. When these CKO mice were supplied with P4 in the afternoon of dpc 1 (day post copulation), most of the embryos can form blastocysts; when CKO mice were supplied with P4 from the morning of dpc1, one-third of the embryos can reach blastocyst stage; however, the supplement of P4 in the morning of dpc 2 made very few of the embryos become blastocysts. We conclude that early exposure to P4 is essential for timely progression of early embryogenesis in the mouse.
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[Extraction of surface active substance and analysis of demulsifying characteristics for the demulsifying strain Alcaligenes sp. S-XJ-1].
Huan Jing Ke Xue
PUBLISHED: 09-14-2013
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Extraction and identification of surface active substance of Alcaligenes sp. S-XJ-1, as well as description of its emulsion breaking process were conducted to reveal the demulsifying characteristics of this demulsifying strain. Alkali solvent was adopted in the extraction process with conditions optimized as 35 degrees C, 0.08 mol x L(-1) of alkali concentration, 12 g x L(-1) of sample to solution ratio, and 4 h of extraction time by launching both single-factor and orthogonal tests. Under this optimal condition, the extracted surface active substance (the extraction ratio was 36.1%) achieved 77% emulsion breaking ratio for 500 mg x L(-1) within 48 h. FT-IR showed the existence of glycolipids, lipids and proteins in the surface active substance, the molecular weight of which mainly scattered between 55 and 61 256. Saccharides, lipids and proteins were identified as the three chief components in surface active substance with the content of 22.2%, 7.5% and 13.4%, respectively. The proteins were further proved to take the most responsibility for the emulsion breaking ability. Moreover, obvious difference in the emulsion breaking process was demonstrated between the original demulsifying strain S-XJ-1 and the extracted surface active substance by real time observation of Turbiscan Lab Expert. The results suggested that the demulsifying efficiency of the strain was jointly contributed by its surface active substance and demulsifying cell morphology, and the former possessed higher functional priority than the latter.
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Preparation and optimization of triptolide-loaded solid lipid nanoparticles for oral delivery with reduced gastric irritation.
Molecules
PUBLISHED: 08-26-2013
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Triptolide (TP) often causes adverse reactions in the gastrointestinal tract when it is administered orally. This study aimed to prepare and optimize triptolide-loaded solid lipid nanoparticles (TP-SLN) with reduced gastric irritation. The microemulsion technique was used to formulate TP-SLN employing a five-level central composite design (CCD) that was developed for exploring the optimum levels of three independent variables on particle size, encapsulation efficiency (EE) and drug loading (DL). Quadratic polynomial models were generated to predict and evaluate the three independent variables with respect to the three responses. The optimized TP-SLN was predicted to comprise fraction of lipid of 49.73%, surfactant to co-surfactant ratio of 3.25, and lipid to drug ratio of 55.27, which showed particle size of 179.8 ± 5.7 nm, EE of 56.5 ± 0.18% and DL of 1.02 ± 0.003% that were in good agreement with predicted values. In addition, the optimized nanoparticles manifested a sustained-release pattern in vitro and were stable during 3 h of incubation in simulated gastric fluids without significant size change and the majority (91%) of the drug was protected. Furthermore, the nanoparticles did not show obvious gastric irritation caused by oral administration of TP in rats.
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[Species sensitivity evaluation of Pseudorasbora parva].
Huan Jing Ke Xue
PUBLISHED: 08-17-2013
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Acute toxic effects of cadmium and copper to Pseudorasbora parva and copper to Daphnia magna were tested in this study. Then comparative analysis of species sensitivity of P. parva to six typical pollutants was performed with toxicity data from our experiments and published literatures. The result showed that: (1) P. parva was generally sensitive to various pollutants, especially to organic pollutants, and it was relatively most sensitive to pesticides. P. parva might be an indicator organism in organic pollution monitoring and a representative testing organism in the development of water quality criteria. (2) Cyprinidae was sensitive to various pollutants in fish sensitivity distribution, therefore the toxicity data of Cyprinidae should be given more attention in the study of water quality criteria and environmental monitoring. (3) P. parva was sensitive to various pollutants, and it had a stable position in fish sensitivity rank. This study indicated that P. parva might be an ideal indicator organism in environmental monitoring and a potential model organism in water quality criteria considering that it has a small size and is easy to obtain.
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[Imaging assessment of neonatal necrotizing enterocolitis].
Zhonghua Er Ke Za Zhi
PUBLISHED: 08-15-2013
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To improve the understanding of recognizing and diagnosis of neonatal necrotizing enterocolitis (NEC), imaging assessment of neonates with NEC was analyzed retrospectively.
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N-lauroyl chitosan surface-modified PLGA nanoparticles as carrier for adriamycin to overcome cancer drug resistance.
J Microencapsul
PUBLISHED: 08-13-2013
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Abstract N-lauroyl chitosan (NLCS) conjugates with different degrees of substitution (DS) of lauroyl group were synthesized and used to prepare surface modified poly(lactic-co-glycolic) acid (NLCS-PLGA) nanoparticles via hydrophobic interaction and ionic bond force. NLCS-PLGA nanoparticles had spherical shape with shell-core structure and exhibited the smallest size and narrowest size distribution when DS of lauroyl group of NLCS was 8.5%. Adriamycin (ADR), as a model antitumor drug, was loaded into NLCS-PLGA nanoaprticles and its initial burst release from PLGA nanoparticles was significantly reduced. MTT assay showed that NLCS-2-PLGA nanoaprticles evidently enhanced cytotoxicity of ADR against drug-resistant breast cancer MCF-7/ADR cells, both compared to free ADR and ADR-loaded PLGA nanoparticles. Moreover, cell-live images showed that the cellular uptake and nuclear location of ADR in MCF-7/ADR cells were significantly enhanced by loading of NLCS-2-PLGA nanoparticles. In conclusion, this novel carrier of anticancer drugs has the potential to overcome drug resistance in cancer cells.
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Expression levels of P-glycoprotein in peripheral blood CD8+ T lymphocytes from HIV-1-infected patients on antiretroviral therapy.
Int. J. Mol. Med.
PUBLISHED: 08-09-2013
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In this study, we aimed to measure P-glycoprotein (P-gp) expression in CD8+ T lymphocytes of HIV-1-infected patients, to investigate how P-gp levels are affected by antiretroviral therapy (ART) in HIV-1 infection, and to assess the value of using P-gp expression to predict virologic response to ART. Peripheral blood mononuclear cells (PBMCs) were obtained from a cohort of HIV-1?infected patients in China: 140 patients on ART, and 49 ART-naïve patients. We also enrolled 24 healthy blood donors as the controls. The expression levels of P-gp in CD8+ T cells of HIV-1-infected patients were evaluated by quantitative reverse transcription PCR, ELISA and flow cytometry. A high inter-individual variability was observed in the CD8+ T cells of both HIV-1-infected patients and healthy donors; however, the expression levels of P-gp were significantly higher in the HIV-1-infected group on ART compared to the ART-naïve group. The relative proportion of P-gp+CD8+ T cells inversely correlated with the blood CD4+ T cell count in the HIV-1?infected patients on ART (r=-0.3343, P=0.0375). Groups of both good and poor responders showed significantly elevated levels of P-gp+CD8+ T cells. The percentage of P-gp+CD8+ T cells appeared to provide a sensitive estimate of the virologic response to ART compared to the CD4+ T cell count. Our results suggest that P-gp expression varies among HIV-1?infected patients, but is significantly higher in HIV-1?infected patients on ART. The overexpression of P-gp is involved in ART initiation during HIV-1 infection, and P-gp+CD8+ T cells may be an additional criterion for the evaluation of the antiretroviral response to ART.
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[Preparation of magnetic quaternary chitosan salt and its adsorption of methyl orange from water].
Huan Jing Ke Xue
PUBLISHED: 08-07-2013
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First, quaternary chitosan salts with different substitution degrees were prepared in glycine hydrochloride ([Gly]Cl) ionic liquid. Nano-sized Fe3O4 powder was obtained through chemical co-precipitation method. And then, magnetic quaternary chitosan particles were prepared through inverse suspension cross-linking using Fe3O4 was the nucleus and glutaraldehyde as the cross-linking agent. The influence of different reaction conditions on adsorption was discussed. Adsorption of methyl orange (MO) by magnetic quaternary chitosan particles was studied through the static adsorption method. The results showed that at pH 3.0 and 25 degrees C the adsorption capacity varied from 37.45 mg x g(-1) to 277.5 mg x g(-1) with the MO concentration ranging from 20 mg x L(-1) to 150 mg x L(-1). The adsorption isotherm was fitted to the Freundlich model and the adsorption kinetics was fitted to the pseudo-second order kinetic isotherms capacity experiment. It was found that after the adsorbent was used for four times, its removal rate still exceeded 90%.
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[Preliminary study of rabbit experiment modality for evaluating cardiac fatigue].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 07-18-2013
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This paper presents a preliminary study of rabbit experiment modality incorporating a new indicator for evaluating cardiac function changes, providing a basis for subsequent study of cardiac fatigue. Using only biochemical indicators, such as troponins, is difficult to make a distinction between exercise-induced cardiac fatigue (EICF) and exercise-induced cardiac damage (EICD). Therefore, some new indicators are needed to evaluate cardiac fatigue synthetically. In our study, we used New Zealand white rabbits to conduct a multi-step swimming experiments with load. We made the rabbits reach an exhaustive state to evaluate whether the amplitude ratio of the first to second heart sound (S1/S2) and heart rate (HR) during the exhaustive exercise would be decreased and whether they would be able to recover after the exhaustive exercise for 24 hours. During the first phase of swimming, S1/S2 and HR were increased, and then decreased at exhaustive state. They were recovered after the exhaustive exercise for 24 hours. Overloading led to deaths of three rabbis, and new phenomena from overloading and related to this kind of death were observed. The experiments proved that Multi-steps swimming experiments with loads by using New Zealand white rabbit is useful for studying cardiac fatigue and premonition of sudden cardiac death.
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Systematic correlation between spine plasticity and the anxiety/depression-like phenotype induced by corticosterone in mice.
Neuroreport
PUBLISHED: 07-11-2013
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Unraveling the pathophysiological basis for the development of and recovery from depression is a unique challenge. Dendritic plasticity has been reported to be involved in the development of depression. We modeled an anxiety/depression-like phenotype by chronic corticosterone exposure in mice and reversed this anxiety/depression-like phenotype by long-term treatment with fluoxetine (FLX). Spine density in the hippocampus was detected by Golgi-Cox staining at five time points. The data showed that 35 days of corticosterone exposure led to a decrease in spine density in CA1, concomitant with the onset of depression. Following 25 days of treatment with FLX, the decrease in both the dendritic spine density in the hippocampus and the anxiety/depression-like phenotype induced by chronic corticosterone recovered to normal levels concomitantly. Interestingly, the total spine density changes are all mainly driven by changes in thin and stubby spines, not mushroom spines, following chronic corticosterone or FLX treatment. Our results suggest that the changes in dendritic spine density in the hippocampus may be one of the pathophysiological mechanisms underlying the development of and recovery from depression, and the neuronal plasticity of CA1 is first impaired during the development of depression.
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[Characterization and potential utilization of maize populations in America region].
Yi Chuan
PUBLISHED: 06-19-2013
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Introgression of exotic maize (Zea mays L.) germplasm is an effective approach to broadening the genetic base of Chinese germplasm. America is the center of maize origin and germplasm diversity. By analyzing general combining ability effects and heterosis responses among maize populations from the U.S., International Maize and Wheat Improvement Center (CIMMYT), and Brazil studied by different authors, 24 elite maize populations from America region, including eight U.S. populations, eight CIMMYT populations, and eight Brazilian populations, were identified as having high potential in China. Based on adaptation improvement, we suggest to introgress BSSS(R)C10, BS10(FR)C14, BS13(S)C9, BSK(HI)C8 Syn 3, BR106, Pop44(C8), and Pop45(C3) into Chinese heterotic group A, and introgress BS11(FR)C14, BS16(S)C3 Syn 2, BS29(R)C3, BSCB1(R)C14, BR105, and Pop42(C4) into Chinese heterotic group B by forming semi-exotic populations or pools, respectively, in order to broaden the Chinese germplasm base.
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A novel porous bioceramics scaffold by accumulating hydroxyapatite spherulites for large bone tissue engineering in vivo. II. Construct large volume of bone grafts.
J Biomed Mater Res A
PUBLISHED: 06-05-2013
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In vivo engineering of bone autografts using bioceramic scaffolds with appropriate porous structures is a potential approach to prepare autologous bone grafts for the repair of critical-sized bone defects. This study investigated the evolutionary process of osteogenesis, angiogenesis, and compressive strength of bioceramic scaffolds implanted in two non-osseous sites of dogs: the abdominal cavity and the dorsal muscle. Hydroxyapatite (HA) sphere-accumulated scaffolds with controlled porous structures were prepared and placed in the two sites for up to 6 months. Analyses of retrieved scaffolds found that osteogenesis and angiogenesis were faster in scaffolds implanted in dorsal muscles compared with those placed in abdominal cavities. The abdominal cavity, however, can accommodate larger bone grafts with designed shape. Analyses of scaffolds implanted in abdominal cavities [an environment of a low mesenchymal stem cell (MSC) density] further demonstrated that angiogenesis play critical roles during osteogenesis in the scaffolds, presumably by supplying progenitor cells and/or MSCs as seed cells. This study also examined the relationship between the volume of bone grafts and the physiological environment of in vivo bioreactor. These results provide basic information for the selection of appropriate implanting sites and culture time required to engineer autologous bone grafts for the clinical bone defect repair. Based on these positive results, a pilot study has applied the grafts constructed in canine abdominal cavity to repair segmental bone defect in load-bearing sites (limbs). © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
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Age-related decline of myelin proteins is highly correlated with activation of astrocytes and microglia in the rat CNS.
Int. J. Mol. Med.
PUBLISHED: 05-18-2013
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It has been shown that aging can greatly influence the integrity and ultrastructure of white matter and the myelin sheath; however, studies regarding the effects of aging on the expression of myelin proteins are still limited. In the present study, immunohistochemical mapping was used to investigate the overall expression of myelin basic protein (Mbp) and myelin oligodendrocyte glycoprotein (Mog) in the central nervous system (CNS) of rats in postnatal months 2, 5, 18 and 26. Astrocyte and microglia activation was also detected by glial fibrillary acidic protein (GFAP) or ionized calcium-binding adaptor molecule 1 (Iba1) staining and western blotting. A significant decline of Mbp and Mog was identified as a universal alteration in the CNS of aged rats. Aging also induced significant astrocyte and microglial activation. Correlation analysis indicated a negative correlation between the reduction of age?related myelin proteins and glial activation in aging. This correlation of myelin breakdown and glial activation in aging may reveal new evidence in connecting the inflammation and myelin breakdown mechanism of age?related neurodegenerative diseases.
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[mir122 deficiency inhibits differentiation of zebrafish hepatoblast into hepatocyte].
Yi Chuan
PUBLISHED: 05-11-2013
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As one of the largest internal organs in the body, liver is very important for metabolism, detoxification and homeostasis. Its reported that liver development is accurately regulated by a gene regulating network consists of FGF, BMP, WNT signal pathways and a lot of transcription factors. However, the functions of microRNA are poorly understood during liver formation. In recent years, it has been reported that mir122 is highly expressed in hepatocytes, and plays a vital role in the metabolic processes of the liver, but its function in liver development remains unclear. In this study, we report that mir122 is specifically expressed in zebrafish (Danio rerio) embryonic liver, and its expression level is notably increased during the differentiation process of hepatoblast into hepatocyte. mir122 inactivation by an antisense morpholino has no influence on the specification, budding and outgrowth of hepatoblast. However, zbrafish hepatoblast can not differentiate into hepatocyte without mir122. Therefore, mir122 is not only involved in liver metabolic functions, but also indispensable for hepatoblast differentiation.
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Cytoplasmic expression of the ELAV-like protein HuR as a potential prognostic marker in esophageal squamous cell carcinoma.
Tumour Biol.
PUBLISHED: 05-09-2013
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Esophageal squamous cell carcinoma (ESCC) is one of the most frequent cancers and a leading cause of death from cancer in China. The human ELAV-like protein HuR has been found to contribute to cancer development and progression through stabilizing a group of cellular mRNAs of cancer-related genes. In this study, we investigated the expression of HuR in a cohort of ESCC patients using immunohistochemical staining. HuR detected in the cytoplasm of cancer cells was positive in 46.6 % of 58 ESCC specimens; 75.9 % of these specimens had nuclear immunoreactivity for HuR. Cytoplasmic HuR expression was higher in cancer tissues compared to 20 matched adjacent noncancerous tissues. A clinicopathological study showed that cytoplasmic HuR expression was positively associated with lymph node metastasis, depth of tumor invasion, and advanced stage, whereas nuclear HuR expression was not correlated with any clinicopathological factors. Patients positive for cytoplasmic HuR expression had a cumulative 5-year survival rate of 25.3 %, whereas it was 43.8 % for patients negative for cytoplasmic HuR expression. In a multivariate analysis, cytoplasmic HuR expression was an independent prognostic factor, whereas nuclear positivity for HuR was not. Our results indicate that high cytoplasmic HuR expression is associated with positive lymph node metastasis, deep tumor invasion, high stage, and poor survival in ESCC. Thus, HuR is the first mRNA stability protein whose expression is associated with poor survival in esophageal cancer.
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Crystal structure of the ?-hydroxymuconic semialdehyde dehydrogenase from Pseudomonas sp. strainWBC-3, a key enzyme involved in para-Nitrophenol degradation.
BMC Struct. Biol.
PUBLISHED: 05-06-2013
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para-Nitrophenol (PNP) is a highly toxic compound with threats to mammalian health. The pnpE-encoded ?-hydroxymuconic semialdehyde dehydrogenase catalyzes the reduction of ?-hydroxymuconic semialdehyde to maleylacetate in Pseudomonas sp. strain WBC-3, playing a key role in the catabolism of PNP to Krebs cycle intermediates. However, the catalyzing mechanism by PnpE has not been well understood.
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Comparison of species sensitivity distributions for species from China and the USA.
Environ Sci Pollut Res Int
PUBLISHED: 05-02-2013
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China has recently commenced water quality criteria (WQC) research using the species sensitivity distribution (SSD) method; however, it is difficult to obtain sufficient native species toxicity data for thousands of contaminants. In this study, the feasibility of using non-native toxicity data in deriving native WQC was analyzed. We constructed SSDs based on acute toxicity data of species from China and the USA for eight priority pollutants, and compared the sensitivities of different taxonomic groups between the two countries. The results showed that the SSD method of log-logistic distribution fit the toxicity data of different taxa well. The comparison of sensitivity distribution and hazardous concentration for 5 % of the species and 50 % of the species showed that there was no significant difference between Chinese and American taxa. It could be feasible to use toxicity data from the USA to provide a temporary way to protect organisms in China in emergency situations or for management of priority pollutants when native toxicity data are lacking.
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Teratogenic effects of organic extracts from the Pearl River sediments on Xenopus laevis embryos.
Environ. Toxicol. Pharmacol.
PUBLISHED: 04-26-2013
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Toxicity of organic extracts from the Pearl River sediments was investigated with Xenopus laevis embryos. The effects of sediment organic extracts on the mortality, body length and malformation of X. laevis embryos were tested by the Frog Embryo Teratogenesis Assay-Xenopus (FETAX). The 96-h LC50 values for X. laevis embryos ranged from 62 to 137g/L (g extracted sediment per L), and the toxicity effect on body length of larvae was not significant under 20g/L. However, the teratogenic effects produced by sediment organic extracts were diverse, including edema, hypopigmentation, cardiac and ocular malformations, abdomen recurved and curved spine. The percentage of malformations increased with increasing sediment organic extracts, and even reached almost 100% at 10 and 20g/L in Guangzhou district. A gradient of pollution in the Pearl River sediments was discerned from the teratogenic toxicity. Guangzhou district showed higher teratogenic toxicity compared with Panyu and Nansha districts as a possible consequence of high levels of PAHs, PCBs, OCPs and NP in the sediments. The teratogenic effects of organic extracts from the Pearl River sediments were successfully assessed which indicated the feasibility of teratogenic potential studies of sediments using X. laevis embryos.
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Development of aquatic life criteria for triclosan and comparison of the sensitivity between native and non-native species.
J. Hazard. Mater.
PUBLISHED: 04-24-2013
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Triclosan (TCS) is an antimicrobial agent which is used as a broad-spectrum bacteriostatic and found in personal care products, and due to this it is widely spread in the aquatic environment. However, there is no paper dealing with the aquatic life criteria of TCS, mainly result from the shortage of toxicity data of different taxonomic levels. In the present study, toxicity data were obtained from 9 acute toxicity tests and 3 chronic toxicity tests using 9 Chinese native aquatic species from different taxonomic levels, and the aquatic life criteria was derived using 3 methods. Furthermore, differences of species sensitivity distributions (SSD) between native and non-native species were compared. Among the tested species, demersal fish Misgurnus anguillicaudatus was the most sensitive species, and the fishes were more sensitive than the aquatic invertebrates of Annelid and insect, and the insect was the least sensitive species. The comparison showed that there was no significant difference between SSDs constructed from native and non-native taxa. Finally, a criterion maximum concentration of 0.009 mg/L and a criterion continuous concentration of 0.002 mg/L were developed based on different taxa, according to the U.S. Environmental Protection Agency guidelines.
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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.