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Find video protocols related to scientific articles indexed in Pubmed.
Synthesis and Herbicidal Evaluation of Triketone-containing Quinazoline-2,4-diones.
J. Agric. Food Chem.
PUBLISHED: 11-19-2014
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Exploring novel 4-hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27, HPPD) inhibitors is one of the most promising research directions in herbicide discovery. To discover new triketone herbicides with broad-spectrum weed control as well as the excellent crop selectivity, a series of (total 52) novel triketone-containing quinazoline-2,4-dione derivatives were synthesized and further bio-evaluated. The greenhouse testing indicated that many of newly synthesized compounds showed better or the excellent herbicidal activity against broadleaf and monocotyledonous weeds at the dosages of 37.5-150 g ai/ha. The structure and activity relationship in this study indicated that triketone-containing quinazoline-2, 4-dione motif has possessed a great impact on herbicide activity and may be utilized for further optimization. Among the new compounds, III-b and VI-a~d displayed broader spectrum of weed control than mesotrione. In addition, the compound III-b also demonstrated comparatively superior crop selectivity to mesotrione, thus possessing a great potential for weed control in field.
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AgNP-DNA@GQDs Hybrid: A New Approach for Sensitive Detection of H2O2 and Glucose via Simultaneous AgNP Etching and DNA Cleavage.
Anal. Chem.
PUBLISHED: 11-13-2014
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A growing body of evidence suggests that hydrogen peroxide (H2O2) plays an active role in the regulation of various physiological processes. Development of sensitive probes for H2O2 is an urgent work. In this study, we proposed a DNA-mediated silver nanoparticles and graphene quantum dots hybrid nanocomposite (AgNP-DNA@GQDs) for sensitive fluorescent detection of H2O2 and the sensing mechanism is based on the etching effect of H2O2 to AgNP and the cleavage of as-generated hydroxyl radicals (•OH) to DNA. The formation of AgNP-DNA@GQDs nanocomposite results in fluorescence quenching of GQDs by AgNP through the resonance energy transfer. Upon H2O2 addition, the energy transfer between AgNP and GQDs mediated by DNA was weakened and obvious fluorescence recovery of GQDs could be observed. It is worth noting that the reaction product •OH between H2O2 and AgNP could cleave the DNA-bridge and thus enhance the AgNP-DNA@GQDs disassembly to further achieve signal amplification. With optimal condition, the approach achieves lowest limit of detection values of 0.11 ?M. Moreover, this nanocomposite is further extended to the detection of glucose in human urine combining with glucose oxidase (GOx) for the oxidation of glucose and formation of H2O2. The glucose concentrations in human urine are detected with satisfactory recoveries of 94.6-98.8% which holds potential of ultrasensitive quantitative analysis of glucose and supply valuable information for diabetes mellitus research and clinical diagnosis.
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Metabolic control of Ca2+/Calmodulin-dependent protein kinase II (CaMKII)-mediated Caspase-2 suppression by the B55?/protein phosphatase 2A (PP2A).
J. Biol. Chem.
PUBLISHED: 11-08-2014
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High levels of metabolic activity confer resistance to apoptosis. Caspase-2, an apoptotic initiator, can be suppressed by high levels of nutrient flux through the pentose phosphate pathway (PPP). This metabolic control is exerted via inhibitory phosphorylation of the caspase-2 pro-domain by activated Ca(2+)/Calmodulin-dependent protein kinase II (CaMKII). We show here that this activation of CaMKII depends, in part, on dephosphorylation of CaMKII at novel sites (T393/S395) and that this is mediated by metabolic activation of protein phosphatase 2A (PP2A) in complex with the B55? targeting subunit. This represents a novel locus of CaMKII control and also provides a mechanism contributing to metabolic control of apoptosis. These findings may have implications for metabolic control of the many CaMKII-controlled and PP2A-regulated physiological processes, as both enzymes appear to be responsive to alterations in glucose metabolized via the PPP.
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Concurrent Chemoradiotherapy with or without Induction Chemotherapy versus Chemotherapy Alone in Patients with Locally Advanced Pancreatic Cancer.
Anticancer Res.
PUBLISHED: 11-05-2014
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The role of chemoradiotherapy (CRT) in the management of locally advanced pancreatic cancer is controversial. We aimed to explore this issue by retrospectively comparing the efficacy of concurrent CRT with or without induction (CT) versus CT alone in patients with locally advanced pancreatic cancer (LAPC).
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Liraglutide for the Treatment of Type 2 Diabetes Mellitus: A Meta-analysis of Randomized Placebo-Controlled Trials.
Adv Ther
PUBLISHED: 10-08-2014
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Liraglutide has been widely used in the treatment of type 2 diabetes mellitus (T2DM), however, the results of a number of randomized placebo-controlled trials on the effects of liraglutide for the treatment of T2DM have varied. The purpose of this study was to assess the effects of liraglutide versus placebo for the treatment of T2DM.
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Remote-Controlled Release of DNA in Living Cells via Simultaneous Light and Host-Guest Mediations.
Anal. Chem.
PUBLISHED: 10-06-2014
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Using photons as external triggers to realize remote-controlled release of oligonucleotide is superior to other intracellular or external stimulus. UV light is a valid photon-controlled manner due to high efficiency. However, further applications of these approaches in living cells are hampered by the large dose of UV-light irradiation. To address this issue, a simultaneous light and host/guest mediation was proposed in this paper. Gold nanoparticles (AuNPs) encoding with mercapto-?-cyclodextrin (?CD) served as a carried agent. Azobenzene (Azo), which was labeled on a releasing oligonucleotide, acted as a photochemically controlled switch. Ferrocene (Fc), an excellent guest for inclusion complexation by ?CD, serves as "enhancers" and shifts the equilibrium of the inclusion-exclusion process between trans-Azo and ?CD under UV-light irradiation, thus making the dose of UV-light irradiation reduced obviously. For further application, transfected green fluorescent protein (GFP)-expressing human lung cancer A549 cells were used to determine cellular uptake and gene silencing mediated by our constructed system in vivo. The results demonstrate that by employing Fc host-guest interaction, about 62.4% gene silencing was achieved within 30 min, which is significantly higher than that without Fc competition. Our strategy provides the potential for orthogonal DNA delivery and therapeutic activation that would be capable of achieving higher levels of site-specific activity and reduced amounts of side effects.
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Redox-Responsive Repressor Rex Modulates Alcohol Production and Oxidative Stress Tolerance in Clostridium acetobutylicum.
J. Bacteriol.
PUBLISHED: 09-02-2014
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Rex, a transcriptional repressor that modulates its DNA-binding activity in response to NADH/NAD(+) ratio, has recently been found to play a role in the solventogenic shift of Clostridium acetobutylicum. Here, we combined a comparative genomic reconstruction of Rex regulons in 11 diverse clostridial species with detailed experimental characterization of Rex-mediated regulation in C. acetobutylicum. The reconstructed Rex regulons in clostridia included the genes involved in fermentation, hydrogen production, the tricarboxylic acid cycle, NAD biosynthesis, nitrate and sulfite reduction, and CO2/CO fixation. The predicted Rex-binding sites in the genomes of Clostridium spp. were verified by in vitro binding assays with purified Rex protein. Novel members of the C. acetobutylicum Rex regulon were identified and experimentally validated by comparing the transcript levels between the wild-type and rex-inactivated mutant strains. Furthermore, the effects of exposure to methyl viologen or H2O2 on intracellular NADH and NAD(+) concentrations, expression of Rex regulon genes, and physiology of the wild type and rex-inactivated mutant were comparatively analyzed. Our results indicate that Rex responds to NADH/NAD(+) ratio in vivo to regulate gene expression and modulates fermentation product formation and oxidative stress tolerance in C. acetobutylicum. It is suggested that Rex plays an important role in maintaining NADH/NAD(+) homeostasis in clostridia.
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Hydrothermal degradation of lignin: Products analysis for phenol formaldehyde adhesive synthesis.
Int. J. Biol. Macromol.
PUBLISHED: 08-08-2014
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Corncob lignin was treated with pressurized hot water in a cylindrical autoclave in current investigation. With the aim of investigating the effect of reaction temperature and retention time on the distribution of degradation products, the products were divided into five fractions including gas, volatile organic compounds, water-soluble oil, heavy oil, and solid residue. It was found that hydrothermal degradation of corncob lignin in pressurized hot water produced a large amount of phenolic compounds with lower molecular weight than the raw lignin. Some phenolic and benzene derivatives monomers such as vanillin, 2-methoxy-phenol, 2-ethyl-phenol, p-xylene, and 1, 3-dimethyl-benzene were also identified in the degradation products. The products were further analyzed by GC-MS, GPC, 2D-HSQC, and (31)P-NMR to investigate their suitability for partial incorporation into phenol formaldehyde adhesive as a substitution of phenol. The results indicated that the reaction temperature had more effect on the products distribution than the retention time. The optimal condition for heavy oil production appeared at 290°C with retention time 0min. The compounds of heavy oil had more active sites than the raw lignin, suggesting that the heavy oil obtained from hydrothermal degradation of lignin is a promising material for phenol formaldehyde adhesive synthesis.
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Identification and characterization of phenol hydroxylase from phenol-degrading Candida tropicalis strain JH8.
Can. J. Microbiol.
PUBLISHED: 07-28-2014
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The gene phhY encoding phenol hydroxylase from Candida tropicalis JH8 was cloned, sequenced, and expressed in Escherichia coli. The gene phhY contained an open reading frame of 2130 bp encoding a polypeptide of 709 amino acid residues. From its sequence analysis, it is a member of a family of flavin-containing aromatic hydroxylases and shares 41% amino acid identity with phenol hydroxylase from Trichosporon cutaneum. The recombinant phenol hydroxylase exists as a homotetramer structure with a native molecular mass of 320 kDa. Recombinant phenol hydroxylase was insensitive to pH treatment; its optimum pH was at 7.6. The optimum temperature for the enzyme was 30 °C, and its activity was rapidly lost at temperatures above 60 °C. Under the optimal conditions with phenol as substrate, the K(m) and V(max) of recombinant phenol hydroxylase were 0.21 mmol·L(-1) and 0.077 ?mol·L(-1)·min(-1), respectively. This is the first paper presenting the cloning and expression in E. coli of the phenol hydroxylase gene from C. tropicalis and the characterization of the recombinant phenol hydroxylase.
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[Clinical observation on removal of small foreign bodies touching the optic nerve in the deep orbital region].
Zhonghua Yan Ke Za Zhi
PUBLISHED: 07-24-2014
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To evaluate the treatment and therapeutic efficacy of extraction of deep intra-orbital little foreign bodies touching the optic nerve.
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Design of a simultaneous target and location-activatable fluorescent probe for visualizing hydrogen sulfide in lysosomes.
Anal. Chem.
PUBLISHED: 07-14-2014
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Molecular tools capable of providing information on a target analyte in an organelle of interest are especially appreciated. Traditionally, organelle-targetable probes are designed by incorporating an organelle-specific guiding unit to target the probe molecules into the organelle. The imperfect targeting function of the guiding unit and nonspecific distribution of the analyte in cytosol and each organelle would lead to low spatiotemporal resolution and limited sensitivity. To solve this problem, we report herein a new approach for detection of a target analyte in a specific organelle by engineering a target and location dual-controlled molecular switch. For this proof-of-concept study, fluorescent detection of H2S in lysosomes was performed with a simultaneous H2S and proton-activatable probe based on the acidic environment of lysosomes. The new synthesized fluorescent sensor, "SulpHensor", which contains a spirolactam moiety to bind hydrogen protons and an azide group to react with H2S, displays highly sensitive and selective fluorescence response to H2S under lysosomal pH environment but is out of operation in neutral cytosol and other organelles. Fluorescence imaging shows that SulpHensor is membrane-permeable and suitable for visualization of both the exogenous and endogenous H2S in lysosomes of living cells. The good performance of our proposed approach for H2S sensing demonstrates that this strategy might open up new opportunities for the development of efficient subcellular molecular tools for bioanalytical and biomedical applications.
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[Microbiological properties of two endophytic bacteria isolated from tea (Camellia sinensis L.)].
Wei Sheng Wu Xue Bao
PUBLISHED: 07-11-2014
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We investigated biological activities, physiological and biochemical properties of two endophytic bacteria isolated from fresh leaves of tea plants.
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Fluorescence modulation by absorbent on solid surface: an improved approach for designing fluorescent sensor.
Anal. Chem.
PUBLISHED: 07-10-2014
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Inner filter effect (IFE), a well-known phenomenon of fluorescence quenching resulting from absorption of the excitation or emission light of luminescent species by absorbent, has been used as a smart approach to design fluorescent sensors, which are characterized by the simplicity and flexibility with high sensitivity. However, further application of IFE-based sensors in complex environment is hampered by the insufficient IFE efficiency and low sensitivity resulting from interference of the external environment. In this paper, we report that IFE occurring on a solid substrate surface would solve this problem. As a proof of concept, a fluorescent sensor for intracellular biothiols has been developed on the basis of the absorption of a newly designed thiols-specific chromogenic probe (CP) coupled with the use of a thiols-independent fluorophore, rhodamine 6G (R6G), operative on the IFE on graphene oxide (GO). To construct an efficient IFE system, R6G was covalently attached to GO, and the CP molecules were adsorbed on the surface of R6G-GO via ?-? stacking interaction. The reaction of thiols with CP on R6G-GO decreases the absorption of CP, resulting in the increase of the intensity of R6G fluorescence. The results showed that the IFE efficiency, sensitivity, and dynamic response time of R6G-GO/CP for biothiols could be significantly improved compared with R6G/CP, and furthermore, R6G-GO/CP functioned under complex system and could be used for assaying biothiols in living cells and in human serum samples. This new strategy would be general to explore the development of more effective IFE-based sensors for other analytes of interest.
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Effects and mechanism of downregulation of COX?2 expression by RNA interference on proliferation and apoptosis of human breast cancer MCF?7 cells.
Mol Med Rep
PUBLISHED: 07-09-2014
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The aim of the present study was to investigate the effects of RNA interference with prostaglandin-endoperoxide synthase 2 (COX?2) gene on the proliferation and apoptosis of breast cancer MCF?7 cells, as well as the underlying mechanism. The present study constructed the eukaryotic expression vector of the targeted COX?2 gene, transfected the MCF?7 cells and screened the stably expressed clone. Changes in the COX?2 gene expression in breast cancer MCF?7 cells prior to and following transfection were examined; the proliferation and apoptosis of MCF?7 cells were analyzed. Furthermore, changes in the protein levels of survivin, B-cell lymphoma 2 (Bcl?2) and Bcl-2-associated X (Bax) genes were detected. RNA interference mediated by a lentiviral expression vector significantly decreased the protein expression levels of the COX?2 gene, and therefore, the proliferation and growth of breast cancer MCF?7 cells was significantly suppressed and the apoptotic rate increased. Of note, the mRNA and protein expression levels of survivin and Bcl?2 decreased, while those of Bax increased following COX-2 silencing. RNA interference markedly deactivated the COX?2 gene, suppressed the proliferation of breast cancer MCF?7 cells, and, to a certain extent, enhanced the induced spontaneous apoptosis, which is regulated by the Bax gene. These results provided evidence for the potential applications of RNA interference of the targeted COX?2 gene in gene therapy for the treatment of breast cancer.
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Aberrant epigenetic alteration in Eca9706 cells modulated by nanoliposomal quercetin combined with butyrate mediated via epigenetic-NF-?B signaling.
Asian Pac. J. Cancer Prev.
PUBLISHED: 06-28-2014
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Since the epigenetic alteration in tumor cells can be reversed by the dietary polyphenol quercetin (Q) or butyrate (B) with chemopreventive activity, suggesting that Q or B can be used for chemopreventive as well as therapeutic agent against tumors. In this study the polyphenol flavonoid quercetin (Q) or sodium butyrate (B) suppressed human esophageal 9706 cancer cell growth in dose dependent manner, and Q combined with B (Q+B) could further inhibit Eca9706 cell proliferation than that induced by Q or B alone, compared with untreated control group (C) in MTT assay. The reverse expressions of global DNMT1, NF-?Bp65, HDAC1 and Cyclin D1 were down-regulated, while expressions of caspase-3 and p16INK4? were up-regulated, compared with the C group in immunoblotting; the down-regulated HDAC1-IR (-immunoreactivity) with nuclear translocation, and up-regulated E-cadherin-IR demonstrated in immunocytochemistry treated by Q or B, and Q+B also displayed further negatively and positively modulated effects compared with C group. The order of methylation specific (MS) PCR of p16INK4?: C>B/Q>Q+B group, while the order of E-cadherin expression level was contrary, Q+B>Q/B>C group. Thus, Q/B, especially Q+B display reverse effect targeting both altered DNA methylation and histone acetylation, acting as histone deacetylase inhibitor mediated via epigenetic-NF-?B cascade signaling.
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Can Serum Glypican-3 Be a Biomarker for Effective Diagnosis of Hepatocellular Carcinoma? A Meta-Analysis of the Literature.
Dis. Markers
PUBLISHED: 06-25-2014
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Objective. This review is to evaluate the diagnostic value of serum GPC3 for hepatocellular carcinoma (HCC) due to conflicting results reported. Methods. NCBI PubMed and Embase were comprehensively searched for studies that have used serum GPC3 level as a diagnostic index for HCC. The quality of the included studies was assessed. Subgroup analyses were conducted to evaluate the sensitivity and specificity of GPC3 as a HCC marker. Statistical analysis was performed with the software STATA version 12.0. Results. A total of 22 studies were included. The qualities of included studies were relatively poor. Among them, 18 studies have shown that serum GPC3 is a specific biomarker for HCC, and the pooled sensitivity and specificity of these studies were 69 and 93%, respectively. The other 4 studies have reported conflicting results, which were not caused by races, infection status of HBV and HCV, or assay reagents but due to one common experimental design of enrolling liver cirrhosis patients as control subjects. Conclusions. This meta-analysis indicates that serum GPC3 is elevated in HCC patients compared with healthy individuals, but more studies are needed to evaluate its effectiveness to differentially diagnose HCC and liver cirrhosis.
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Efficacy of a high-growth reassortant H1N1 influenza virus vaccine against the classical swine H1N1 subtype influenza virus in mice and pigs.
Arch. Virol.
PUBLISHED: 06-24-2014
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Swine influenza (SI) is an acute, highly contagious respiratory disease caused by swine influenza A viruses (SwIVs), and it poses a potential global threat to human health. Classical H1N1 (cH1N1) SwIVs are still circulating and remain the predominant subtype in the swine population in China. In this study, a high-growth reassortant virus (GD/PR8) harboring the hemagglutinin (HA) and neuraminidase (NA) genes from a novel cH1N1 isolate in China, A/Swine/Guangdong/1/2011 (GD/11) and six internal genes from the high-growth A/Puerto Rico/8/34(PR8) virus was generated by plasmid-based reverse genetics and tested as a candidate seed virus for the preparation of an inactivated vaccine. The protective efficacy of this vaccine was evaluated in mice and pigs challenged with GD/11 virus. Prime and boost inoculation of GD/PR8 vaccine yielded high-titer serum hemagglutination inhibiting (HI) antibodies and IgG antibodies for GD/11 in both mice and pigs. Complete protection of mice and pigs against cH1N1 SIV challenge was observed, with significantly fewer lung lesions and reduced viral shedding in vaccine-inoculated animals compared with unvaccinated control animals. Our data demonstrated that the GD/PR8 may serve as the seed virus for a promising SwIVs vaccine to protect the swine population.
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A genome-wide screen for non-template nucleotides and isomiR repertoires in miRNAs indicates dynamic and versatile microRNAome.
Mol. Biol. Rep.
PUBLISHED: 06-20-2014
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miRNA variants (termed isomiRs) have been reported as potential functional molecules that may affect miRNA stability or target selection. The aims of the present study were to comprehensively survey and characterize non-template nucleotides (NTNs) and isomiR repertoires in miRNAs. Over 50 % of the NTNs were located in the 3' ends (also termed 3' additions), followed by the 5' ends and adjacent positions to 5' and 3' ends. The similar distributions of NTNs and isomiR repertoires might be detected between homologous or clustered miRNAs. miRNA might be stably expressed based on the typical analysis, but its isomiRs might be strongly up- or down-regulated. IsomiRs with novel seed sequences were mainly derived from "seed shifting" events in 5' isomiRs, NTNs in 5' ends or in seed sequences. IsomiRs from a miRNA locus or homologous miRNA loci maybe have the same seed sequences, but they would have various enrichment levels and 3' ends. Interestingly, isomiR species with novel seed sequences via NTNs in the seed region were always stably expressed. These novel seed sequences could lead to novel functional roles through driving the potential novel target mRNAs. Integrated predicted target mRNAs and further microarray validation showed that these isomiRs have versatile biological roles. Collectively, multiple isomiR products and miRNA maturation processes provide opportunities to perform versatile roles in the regulatory network, which further enriches and complicates the regulation of biological processes.
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Hybrid Procedure for Acute Stanford Type A Aortic Dissection with Aberrant Right Subclavian Artery.
J Card Surg
PUBLISHED: 06-18-2014
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Aberrant right subclavian artery (ARSA) is an uncommon congenital vascular abnormality. Acute Stanford type A aortic dissection with ARSA is rare. We report a strategy for Stanford type A aortic dissection with ARSA. The ascending aorta and the total aortic arch were replaced and a frozen elephant trunk was implanted into the descending aorta. The right subclavian artery was reconstructed with the perfusion branch of a four-branch prosthetic graft. Two weeks later, the proximal part of the ARSA was sealed with a vascular plug.
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Syntheses of coumarin-tacrine hybrids as dual-site acetylcholinesterase inhibitors and their activity against butylcholinesterase, A? aggregation, and ?-secretase.
Bioorg. Med. Chem.
PUBLISHED: 06-17-2014
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Exploring small-molecule acetylcholinesterase (AChE) inhibitors to slow the breakdown of acetylcholine (Ach) represents the mainstream direction for Alzheimer's disease (AD) therapy. As the first acetylcholinesterase inhibitor approved for the clinical treatment of AD, tacrine has been widely used as a pharmacophore to design hybrid compounds in order to combine its potent AChE inhibition with other multi-target profiles. In present study, a series of novel tacrine-coumarin hybrids were designed, synthesized and evaluated as potent dual-site AChE inhibitors. Moreover, compound 1g was identified as the most potent candidate with about 2-fold higher potency (Ki=16.7nM) against human AChE and about 2-fold lower potency (Ki=16.1nM) against BChE than tacrine (Ki=35.7nM for AChE, Ki=8.7nM for BChE), respectively. In addition, some of the tacrine-coumarin hybrids showed simultaneous inhibitory effects against both A? aggregation and ?-secretase. We therefore conclude that tacrine-coumarin hybrid is an interesting multifunctional lead for the AD drug discovery.
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Effect of cycloxygenase-2 silencing on the malignant biological behavior of MCF-7 breast cancer cells.
Oncol Lett
PUBLISHED: 06-12-2014
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The aim of the present study was to investigate the effect of cyclooxygenase-2 (COX-2) silencing on the malignant biological behavior of MCF-7 breast cancer cells. COX-2 short hairpin RNA (shRNA) and unassociated sequences were synthesized and a shRNA lentiviral vector was constructed. The vector was transfected into MCF-7 breast cancer cells, in which clones with stable expression were screened out. The expression of COX-2 mRNA and protein was silenced using RNA interference (RNAi). Quantitative polymerase chain reaction, western blotting, a mononuclear cell direct cytotoxicity assay (MTT assay), a cell invasion assay and scratch tests were performed to investigate the downregulation of COX-2 mRNA and protein expression, the proliferative activity and growth rate of MCF-7 breast cancer cells, the glioblastoma multiforme (GBM) penetrating capacity, the cell movement and migratory capacity, and vascular endothelial growth factor (VEGF)-A and VEGF-C protein expression. The results revealed that the sequence-specific shRNA significantly downregulated the expression of COX-2 at the mRNA and protein levels. Furthermore, the downregulation of COX-2 expression markedly decreased the invasive and metastatic capacities of the cells, suppressed the proliferation, decreased the rate of growth, decreased the capacity of GBM penetration and migration, and decreased the protein expression of VEGF-A and VEGF-C, the two key factors that regulate tumor angiogenesis and lymphangiogenesis. In conclusion, the RNAi technique effectively silenced COX-2 gene expression and inhibited MCF-7 breast cancer cell proliferation, invasion and metastasis by decreasing VEGF-A and VEGF-C expression, which regulates tumor angiogenesis and lymphangiogenesis. Therefore, an RNAi technique that targets COX-2 presents a promising prospect for breast cancer gene therapy.
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Fabrication of versatile cyclodextrin-functionalized upconversion luminescence nanoplatform for biomedical imaging.
Anal. Chem.
PUBLISHED: 06-12-2014
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Lanthanide-based upconversion nanoparticles (UCNPs) are a new type of luminescent tags that show great application potential in biomedical fields. However, a major challenge when applying UCNPs in biomedical research is the lack of a versatile strategy to make water-dispersible and biocompatible UCNPs with high simplicity in functionalization. To address this problem, in the present work, we employed 6-phosphate-6-deoxy-?-cyclodextrin (?PCD) as the novel ligand to fabricate a versatile upconversion luminescent nanoplatform. Using ?PCD as the surface ligand not only enhances the stability and biocompatibility of the UCNPs under physiological conditions but also enables simple conjugation with various functional molecules, such as organic dyes and biomolecules, via the host-guest interaction between those molecules and the cyclodextrin cavity. The conjugated upconversion nanoprobe then displays excellent capability in labeling the cancer cells and tumor tissue slices for luminescent imaging. These results demonstrate that the versatile cyclodextrin-functionalized upconversion nanoplatform appears particularly flexible for further modifications, indicating great potential for applications in biosensing and bioimaging.
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Dual-stimuli responsive i-motif/nanoflares for sensing ATP in lysosomes.
Analyst
PUBLISHED: 06-07-2014
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A dual-stimuli responsive i-motif/nanoflare for molecule detection in lysosomes was designed. By combining the structure-switchable i-motif sequence and high recognition ability of an adenosine triphosphate (ATP) aptamer, subcellular sensing and visualization sensing of ATP in lysosomes at the subcellular level can be achieved. This general sensing technique can be applied for a broad range of cellular communication studies to improve our understanding of subcellular signaling and function.
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Graphene oxide assisted fluorescent chemodosimeter for high-performance sensing and bioimaging of fluoride ions.
ACS Appl Mater Interfaces
PUBLISHED: 05-29-2014
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Fluorescent chemodosimeters for a fluoride ion (F(-)) based on a specifically F(-)-triggered chemical reaction are characterized by high selectivity. However, they are also subjected to intrinsic limits, such as long response time, poor stability under aqueous solution, and unpredictable cell-member penetration. To address these issues, we reported here that the self-assembly of fluorescent chemodosimeter molecules on a graphene oxide (GO) surface can solve these problems by taking advantage of the excellent chemical catalysis and nanocarrier functions of GO. As a proof of concept, a new F(-)-specific fluorescent chemodosimeter molecule, FC-A, and the GO self-assembly structure of GO/FC-A were synthesized and characterized. Fluorescent sensing and imaging of F(-) with FC-A and GO/FC-A were performed. The results showed that the reaction rate constant of GO/FC-A for F(-) is about 5-fold larger than that of FC-A, so that the response time was shortened from 4 h to about 30 min, while for F(-), the response sensitivity of GO/FC-A was >2-fold higher than that of FC-A. Furthermore, GO/FC-A showed a better bioimaging performance for F(-) than FC-A because of the nanocarrier function of GO for cells. It is demonstrated that this GO-based strategy is feasible and general, which could help in the exploration of the development of more effective fluorescent nanodosimeters for other analytes of interest.
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[Prospective multicentre study of chemotherapeutic regimen containing pirarubicin on the treatment of relapsed or refractory acute myeloid leukemia in adults].
Zhonghua Xue Ye Xue Za Zhi
PUBLISHED: 05-27-2014
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To compare the efficacy and toxicity of the chemotherapeutic regimen containing pirarubicin and mitoxantrone on the treatment of relapsed or refractory acute myeloid leukemia (AML) in adults.
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TS-Chemscore, a Target-Specific Scoring Function, Significantly Improves the Performance of Scoring in Virtual Screening.
Chem Biol Drug Des
PUBLISHED: 05-25-2014
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Most of the scoring functions currently used in structure-based drug design belong to "universal" scoring functions, which often give a poor correlation between the calculated scores and experimental binding affinities. In this investigation, we proposed a simple strategy to construct target-specific scoring functions based on known "universal" scoring functions. This strategy was applied to Chemscore, a widely used empirical scoring function, which led to a new scoring function, termed TS-Chemscore. TS-Chemscore was validated on 14 protein targets, which cover a wide range of biological target categories. The results showed that TS-Chemscore significantly improved the correlation between the calculated scores and experimental binding affinities compared with the original Chemscore. TS-Chemscore was then applied in virtual screening to retrieve novel JAK3 and YopH inhibitors. Top 30 compounds for each target were selected for experimental validation. Six active compounds for JAK3 and four for YopH were obtained. These compounds were out of the lists of top 30 compounds sorted by Chemscore. Collectively, TS-Chemscore established in this study showed a better performance in virtual screening than its counterpart Chemscore. This article is protected by copyright. All rights reserved.
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One-step integration of multiple genes into the oleaginous yeast Yarrowia lipolytica.
Biotechnol. Lett.
PUBLISHED: 05-21-2014
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Yarrowia lipolytica is an unconventional yeast, and is generally recognized as safe (GRAS). It provides a versatile fermentation platform that is used commercially to produce many added-value products. Here we report a multiple fragment assembly method that allows one-step integration of an entire ?-carotene biosynthesis pathway (~11 kb, consisting of four genes) via in vivo homologous recombination into the rDNA locus of the Y. lipolytica chromosome. The highest efficiency was 21 %, and the highest production of ?-carotene was 2.2 ± 0.3 mg per g dry cell weight. The total procedure was completed in less than one week, as compared to a previously reported sequential gene integration method that required n weeks for n genes. This time-saving method will facilitate synthetic biology, metabolic engineering and functional genomics studies of Y. lipolytica.
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[Efficacy and safety evaluation of gemcitabine combined with oxaliplatin in lymphoma patients after failure of multiple chemotherapy regimens].
Zhonghua Zhong Liu Za Zhi
PUBLISHED: 05-07-2014
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To evaluate the efficacy and safety of gemcitabine combined with oxaliplatin (GEMOX) in lymphoma patients after failure of multiple chemotherapy regimens.
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The prognostic utility and the association of serum light chains (free and total) and absolute lymphocyte count in patients with newly diagnosed diffuse large B-cell lymphoma.
Leuk. Res.
PUBLISHED: 05-06-2014
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In this study, serum free and total light chains (sFLC/sTLC) were measured in 108 serum samples of therapy-naïve patients with DLBCL. Clinicopathologic data and survival outcomes were analyzed according to the results of sFLC/sTLC measurements. Moreover, the association of sFLC/sTLC with absolute monocyte count (AMC) and absolute lymphocyte count (ALC) was evaluated. Elevated sFLC and abnormal ?/? ratio was present in 42.6% (51/108) and 4.6% (5/108) of patients, respectively. sTLC was successfully measured in 107 serum samples, abnormal sTLC and abnormal ?/? ratio was found in 28.0% (30/107) and 26.2% (28/107) of patients, respectively. Patients with elevated sFLC more frequently displayed adverse clinical characteristics, including age (P=0.001), B symptoms (P=0.022), low ALC (P=0.024) and hyperglobulinemia (P=0.012). Patients with elevated sFLC had an inferior overall survival (OS) (P=0.012) and tended to have shorter progression-free survival (PFS) (P=0.061) compared to patients with normal sFLC. Abnormal sTLC or abnormal sTLC ratio showed no significant association with clinical outcomes, with exception of abnormal concurrent ? and ?. Only association of sFLC and ALC with survival remained significant after adjusting for the International Prognostic Index (IPI). The measurement of sFLC and ALC at diagnosis might be useful for the prognostic stratification of patients and sTLC measurement was of little prognostic utility in DLBCL.
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Clinical features, survival and prognostic factors of primary testicular diffuse large B-cell lymphoma.
Chin. J. Cancer Res.
PUBLISHED: 04-24-2014
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To assess the clinical features, survival and prognostic factors of primary testicular diffuse large B-cell lymphoma (DLBCL).
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High-efficiency scarless genetic modification in Escherichia coli by using lambda red recombination and I-SceI cleavage.
Appl. Environ. Microbiol.
PUBLISHED: 04-18-2014
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Genetic modifications of bacterial chromosomes are important for both fundamental and applied research. In this study, we developed an efficient, easy-to-use system for genetic modification of the Escherichia coli chromosome, a two-plasmid method involving lambda Red (?-Red) recombination and I-SceI cleavage. An intermediate strain is generated by integration of a resistance marker gene(s) and I-SceI recognition sites in or near the target gene locus, using ?-Red PCR targeting. The intermediate strain is transformed with a donor plasmid carrying the target gene fragment with the desired modification flanked by I-SceI recognition sites, together with a bifunctional helper plasmid for ?-Red recombination and I-SceI endonuclease. I-SceI cleavage of the chromosome and the donor plasmid allows ?-Red recombination between chromosomal breaks and linear double-stranded DNA from the donor plasmid. Genetic modifications are introduced into the chromosome, and the placement of the I-SceI sites determines the nature of the recombination and the modification. This method was successfully used for cadA knockout, gdhA knock-in, seamless deletion of pepD, site-directed mutagenesis of the essential metK gene, and replacement of metK with the Rickettsia S-adenosylmethionine transporter gene. This effective method can be used with both essential and nonessential gene modifications and will benefit basic and applied genetic research.
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Lysyl oxidase-like 4 (LOXL4) promotes proliferation and metastasis of gastric cancer via FAK/Src pathway.
J. Cancer Res. Clin. Oncol.
PUBLISHED: 04-14-2014
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Lysyl oxidase-like 4 (LOXL4) has been found up-regulated in a variety of human malignancies, but its clinical significance and functional roles in gastric cancer (GC) remain unknown.
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Utilization of economical substrate-derived carbohydrates by solventogenic clostridia: pathway dissection, regulation and engineering.
Curr. Opin. Biotechnol.
PUBLISHED: 03-21-2014
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Solventogenic clostridia can produce acetone, butanol and ethanol (ABE) by using different carbohydrates. For economical reasons, the utilization of cheap and renewable biomass in clostridia-based ABE fermentation has recently attracted increasing interests. With the study of molecular microbiology and development of genetic tools, the understanding of carbohydrate metabolism in clostridia has increased in recent years. Here, we review the pioneering work in this field, with a focus on dissecting the pathways and describing the regulation of the metabolism of economical substrate-derived carbohydrates by clostridia. Recent progress in the metabolic engineering of carbohydrate utilization pathways is also described.
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Reconstructing the coding and non-coding RNA regulatory networks of miRNAs and mRNAs in breast cancer.
Gene
PUBLISHED: 03-19-2014
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microRNAs (miRNAs) are a class of small non-coding RNAs that deregulate and/or decrease the expression of target messenger RNAs (mRNAs), which specifically contribute to complex diseases. In our study, we reanalyzed an integrated data to promote classification performance by rebuilding miRNA-mRNA modules, in which a group of deregulated miRNAs cooperatively regulated a group of significant mRNAs. In five-fold cross validation, the multiple processes flow considered the biological and statistical significant correlations. First, of statistical significant miRNAs, 6 were identified as core miRNAs. Second, in the 13 significant pathways enriched by gene set enrichment analysis (GSEA), 705 deregulated mRNAs were found. Based on the union of predicted sets and correlation sets, 6 modules were built. Finally, after verified by test sets, three indexes, including area under the ROC curve (AUC), Accuracy and Matthews correlation coefficients (MCCs), indicated only 4 modules (miR-106b-CIT-KPNA2-miR-93, miR-106b-POLQ-miR-93, miR-107-BTRC-UBR3-miR-16 and miR-200c-miR-16-EIF2B5-miR-15b) had discriminated ability and their classification performance were prior to that of the single molecules. By applying this flow to different subtypes, Module 1 was the consistent module across subtypes, but some different modules were still specific to each subtype. Taken together, this method gives new insight to building modules related to complex diseases and simultaneously can give a supplement to explain the mechanism of breast cancer (BC).
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Two-photon graphene oxide/aptamer nanosensing conjugate for in vitro or in vivo molecular probing.
Anal. Chem.
PUBLISHED: 03-14-2014
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Two-photon excitation (TPE) with near-infrared (NIR) photons as the excitation source have the unique properties of lower tissue autofluorescence and self-absorption, reduced photodamage and photobleaching, higher spatial resolution, and deeper penetration depth (>500 ?m). Carbon nanomaterials, for example, graphene oxide (GO), have the advantages of good biocompatibility, efficient transporters into cells, protecting the carried DNA or peptides from enzymatic cleavage, and super fluorescence quenching efficiency. By combination of the nanostructured carbon materials with the TPE technique, herein we have designed an aptamer-two-photon dye (TPdye)/GO TPE fluorescent nanosensing conjugate for molecular probing in biological fluids, living cells, and zebrafish. This approach takes advantage of the exceptional quenching capability of GO for the proximate TP dyes and the higher affinity of single-stranded DNA on GO than the aptamer-target complex. Successful in vitro and in vivo detection of ATP was demonstrated with this sensing strategy. Our results reveal that the GO/Aptamer-TPdye system not only is a robust, sensitive, and selective sensor for quantitative detection of ATP in the complex biological environment but also can be efficiently delivered into live cells or tissues and act as a "signal-on" in vivo sensor for specific, high-contrast imaging of target biomolecules. Our design provides a methodology model scheme for development of future carbon nanomaterial-based two-photon fluorescent probes for in vitro or in vivo determination of biological or biologically relevant species.
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Effect of insecticidal fusion proteins containing spider toxins targeting sodium and calcium ion channels on pyrethroid-resistant strains of peach-potato aphid (Myzus persicae).
Pest Manag. Sci.
PUBLISHED: 03-11-2014
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The recombinant fusion proteins Pl1a/GNA and Hv1a/GNA contain the spider venom peptides ?-amaurobitoxin-PI1a or ?-hexatoxin-Hv1a respectively, linked to snowdrop lectin (GNA). Pl1a targets receptor site 4 of insect voltage-gated sodium channels (NaCh), while Hv1a targets voltage-gated calcium channels. Insecticide-resistant strains of peach-potato aphid (Myzus persicae) contain mutations in NaCh. The pyrethroid-resistant kdr (794J) and super-kdr (UKO) strains contain mutations at residues L1014 and M918 in the channel ?-subunit respectively, while the kdr?+?super-kdr strain (4824J), insensitive to pyrethroids, contains mutations at both L1014 and M918.
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Characterization of plasmid pXL100 from Amycolatopsis orientalis HCCB10007 and construction of a shuttle vector.
J. Basic Microbiol.
PUBLISHED: 03-10-2014
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Many strains of Amycolatopsis, such as Amycolatopsis orientalis, A. balhimycina, and A. mediterranei, are important antibiotic producers. Three indigenous plasmids, pMEA100, pMEA300, and pA387, found in this genus have been sequenced. However, only some vectors based on pA387 have been widely applied in Amycolatopsis research. An indigenous plasmid, pXL100, was isolated from the vancomycin producer A. orientalis HCCB10007. Sequence analysis of pXL100 revealed its total length to be 33,499?bp and GC content to be 68.9%. A 2830-bp fragment containing three ORFs has been identified as essential for replication in A. orientalis, but it has no significant similarity to any known replicons. A vector, pLYZW7-3, was constructed based on the pXL100 replicon and could be transferred into A. mediterranei and A. orientalis by electroporation or conjugation with high frequency. A mutant with a disrupted gene was successfully complemented with the pLYZW7-3 vector, indicating that the vector is potentially useful in Amycolatopsis research.
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An integrated analysis of miRNA, lncRNA, and mRNA expression profiles.
Biomed Res Int
PUBLISHED: 03-07-2014
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Increasing amounts of evidence indicate that noncoding RNAs (ncRNAs) have important roles in various biological processes. Here, miRNA, lncRNA, and mRNA expression profiles were analyzed in human HepG2 and L02 cells using high-throughput technologies. An integrative method was developed to identify possible functional relationships between different RNA molecules. The dominant deregulated miRNAs were prone to be downregulated in tumor cells, and the most abnormal mRNAs and lncRNAs were always upregulated. However, the genome-wide analysis of differentially expressed RNA species did not show significant bias between up- and downregulated populations. miRNA-mRNA interaction was performed based on their regulatory relationships, and miRNA-lncRNA and mRNA-lncRNA interactions were thoroughly surveyed and identified based on their locational distributions and sequence correlations. Aberrantly expressed miRNAs were further analyzed based on their multiple isomiRs. IsomiR repertoires and expression patterns were varied across miRNA loci. Several specific miRNA loci showed differences between tumor and normal cells, especially with respect to abnormally expressed miRNA species. These findings suggest that isomiR repertoires and expression patterns might contribute to tumorigenesis through different biological roles. Systematic and integrative analysis of different RNA molecules with potential cross-talk may make great contributions to the unveiling of the complex mechanisms underlying tumorigenesis.
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HBx protein promotes oval cell proliferation by up-regulation of cyclin D1 via activation of the MEK/ERK and PI3K/Akt pathways.
Int J Mol Sci
PUBLISHED: 02-18-2014
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Growing evidence has shown that hepatic oval cells, also named liver progenitor cells, play an important role in the process of liver regeneration in various liver diseases. Oval cell proliferation has been reported in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) and chronic liver disease. Studies have found expression of HBV surface and core antigens in oval cells in the livers of patients with HCC, suggesting that HBV infection of oval cells could be a mechanism of human hepatocarcinogenesis. In addition, there is evidence of multiplication of HBV in oval cell culture. However, little research has been performed to explore the role of HBV-encoded proteins in the proliferation of hepatic oval cells. Previously, we successfully transfected the HBV x (HBx) gene, one of the four genes in the HBV genome, into a rat LE/6 oval cell line. In this study, we tested whether or not the transfected HBx gene could affect oval cell proliferation in vitro. Our results show that overexpression of HBx promotes the proliferation of oval cells and increases cyclin D1 expression, assessed at both the mRNA and protein levels. We also found that HBx activated the PI-3K/Akt and MEK/ERK1/2 pathways in HBx-transfected oval cells. Furthermore, the HBx-induced increases in cyclin D1 expression and oval cell proliferation were completely abolished by treatment with either MEK inhibitor PD184352 or PI-3K inhibitor LY294002. These results demonstrated that HBx has the ability to promote oval cell proliferation in vitro, and its stimulatory effects on cell proliferation and expression of cyclin D1 depend on the activation of the MEK/ERK and PI3K/Akt signaling pathways in cultured oval cells.
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Development and validation of an ultrafiltration-UPLC-MS/MS method for rapid quantification of unbound docetaxel in human plasma.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 02-13-2014
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Docetaxel lipid microsphere (DT-LM) is a novel formulation of docetaxel without Tween-80. A sensitive, robust and reproducible ultrafiltration (UF) followed by UPLC-MS/MS method was developed and validated for the quantification of unbound docetaxel in human plasma using paclitaxel as IS. Ultrafiltrate samples were chromatographed on Acquity UPLC BEH C18 column (50 mm × 2.1 mm, 1.7 ?m). The mobile phase was a mixture of 10mM ammonium formate in water containing 0.2% formic acid (A) and acetonitrile containing 0.2% formic acid (B). The volume of plasma utilized was only 450 ?L. The calibration curve was linear over the range of 0.2-200 ng/mL, with LLOQ of 0.2 ng/mL. The method was shown to be reliable and reproducible with intra- and inter-day precision and accuracy <±15%, and extraction recovery of 98.1-104.8%. Docetaxel was stable during stability studies, e.g., short term, post-preparation and freeze-thaw cycles. The validated method was utilized to support the pharmacological study of DT-LM in patients with advanced cancer.
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Integrative analysis of miRNA-mRNA and miRNA-miRNA interactions.
Biomed Res Int
PUBLISHED: 02-12-2014
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MicroRNAs (miRNAs) are small, noncoding regulatory molecules. They are involved in many essential biological processes and act by suppressing gene expression. The present work reports an integrative analysis of miRNA-mRNA and miRNA-miRNA interactions and their regulatory patterns using high-throughput miRNA and mRNA datasets. Aberrantly expressed miRNA and mRNA profiles were obtained based on fold change analysis, and qRT-PCR was used for further validation of deregulated miRNAs. miRNAs and target mRNAs were found to show various expression patterns. miRNA-miRNA interactions and clustered/homologous miRNAs were also found to contribute to the flexible and selective regulatory network. Interacting miRNAs (e.g., miRNA-103a and miR-103b) showed more pronounced differences in expression, which suggests the potential "restricted interaction" in the miRNA world. miRNAs from the same gene clusters (e.g., miR-23b gene cluster) or gene families (e.g., miR-10 gene family) always showed the same types of deregulation patterns, although they sometimes differed in expression levels. These clustered and homologous miRNAs may have close functional relationships, which may indicate collaborative interactions between miRNAs. The integrative analysis of miRNA-mRNA based on biological characteristics of miRNA will further enrich miRNA study.
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Association of GCK -30G> a polymorphism with gestational diabetes mellitus and type 2 diabetes mellitus risk: a meta-analysis involving 18 case-control studies.
Genet Test Mol Biomarkers
PUBLISHED: 02-12-2014
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Several studies have examined the association between the GCK -30G>A polymorphism and the risk of gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (T2DM). However, inferences from these studies are hindered by their limited statistical power and conflicting results. The aim of this meta-analysis is to provide a relatively comprehensive picture of the association of the GCK -30G>A polymorphism with GDM and T2DM risk.
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A phase I clinical trial assessing the safety and tolerability of combretastatin A4 phosphate injections.
Anticancer Drugs
PUBLISHED: 02-07-2014
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Combretastatin A4 phosphate (CA4P) is a prodrug that selectively destroys tumor blood vessels, and has shown efficacy as a targeted anticancer drug in both animal models and clinical trials. The aims of this single-center, open label, phase I clinical trial were to investigate the safety and tolerability of CA4P administered intravenously to patients aged 18-65 years with advanced solid tumors. Using a dose-escalation protocol, patients were assigned to five groups that received injections with 20 (n=3), 33 (n=3), 50 (n=11), 65 (n=6), or 85 (n=2) mg/m² CA4P. Patients in the 20 and 85 mg/m² groups received a single dose and the other groups received multiple doses. Adverse events (AE), cardiovascular parameters, and biochemical investigations were studied, and the maximum tolerated dose was determined. Of twenty-five patients enrolled, eight were withdrawn/excluded (not because of AE). There were no deaths. A total of 394 AE occurred in the 25 patients, with 89.3% considered related/possibly related to the drug. AE included headache and dizziness (19.8%), tumor-induced pain (14.2%), vascular vagal excitation (10.7%), and vomiting (9.4%). Ninety-five percent of AE were mild (grades 0-II), with only 5% being grade III-IV. Drug administration was associated with biphasic changes in heart rate and blood pressure, and only limited abnormalities in the laboratory investigations performed. The maximum tolerated dose was 65 mg/m². We conclude that CA4P is generally well tolerated, with the vast majority of AE that occurred being of mild severity. Further studies will establish the role of CA4P in cancer therapy.
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A novel poly(amido amine)-dendrimer-based hydrogel as a mimic for the extracellular matrix.
Adv. Mater. Weinheim
PUBLISHED: 01-21-2014
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The extracellular matrix is mimicked by a novel dendrimer-based hydrogel, which exhibits a highly interconnected porous network, enhanced mechanical stiffness, and a low swelling ratio. The hydrogel system supports the proliferation and differentiation of mesenchymal stem cells without any cytotoxic effects. This dendrimer-based hydrogel may serve as a model for developing new advanced materials with applications in tissue engineering.
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Hepatitis B virus X protein disrupts the balance of the expression of circadian rhythm genes in hepatocellular carcinoma.
Oncol Lett
PUBLISHED: 01-20-2014
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The human circadian rhythm is controlled by at least eight circadian clock genes and disruption of the circadian rhythm is associated with cancer development. The present study aims to elucidate the association between the expression of circadian clock genes and the development of hepatocellular carcinoma (HCC), and also to reveal whether the hepatitis B virus X protein (HBx) is the major regulator that contributes to the disturbance of circadian clock gene expression. The mRNA levels of circadian clock genes in 30 HCC and the paired peritumoral tissues were determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A stable HBx-expressing cell line, Bel-7404-HBx, was established through transfection of HBx plasmids. The mRNA level of circadian clock genes was also detected by RT-qPCR in these cells. Compared with the paired peritumoral tissues, the mRNA levels of the Per1, Per2, Per3 and Cry2 genes in HCC tissue were significantly lower (P<0.05), while no significant difference was observed in the expression levels of CLOCK, BMAL1, Cry1 and casein kinase 1? (CK1?; P>0.05). Compared with Bel-7404 cells, the mRNA levels of the CLOCK, Per1 and Per2 genes in Bel-7404-HBx cells were significantly increased, while the mRNA levels of the BMAL1, Per3, Cry1, Cry2 and CKI? genes were decreased (P<0.05). Thus, the present study identified that disturbance of the expression of circadian clock genes is common in HCC. HBx disrupts the expression of circadian clock genes and may, therefore, induce the development of HCC.
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Bidirectional regulation between TMEFF2 and STAT3 may contribute to Helicobacter pylori-associated gastric carcinogenesis.
Int. J. Cancer
PUBLISHED: 01-20-2014
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The transmembrane protein with epidermal growth factor and two follistatin motifs 2 (TMEFF2) is a single-pass transmembrane protein, and it is downregulated in human gastric cancer and levels correlate with tumor progression and time of survival. However, the mechanism of its dysregulation in gastric cancer is little known. Here we investigate its regulatory mechanism and the bidirectional regulation between TMEFF2 and STAT3 in gastric carcinogenesis. TMEFF2 expression was decreased after Helicobacter pylori (H. pylori) infection in vivo and in vitro. STAT3 directly binds to the promoter of TMEFF2 and regulates H. pylori-induced TMEFF2 downregulation in normal gastric GES-1 cells and gastric cancer AGS cells. Conversely, TMEFF2 may suppress the phosphorylation of STAT3 and TMEFF2-induced downregulation of STAT3 phosphorylation may depend on SHP-1. A highly inverse correlation between the expression of TMEFF2 and pSTAT3 was also revealed in gastric tissues. We now show the deregulation mechanism of TMEFF2 in gastric carcinogenesis and identify TMEFF2 as a new target gene of STAT3. The phosphorylation of STAT3 may be negatively regulated by TMEFF2, and the bidirectional regulation between TMEFF2 and STAT3 may contribute to H. pylori-associated gastric carcinogenesis.© 2014 UICC.
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Label-free fluorescent biosensor based on the target recycling and Thioflavin T-induced quadruplex formation for short DNA species of c-erbB-2 detection.
Anal. Chim. Acta
PUBLISHED: 01-20-2014
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Non-invasive early diagnosis of breast cancer is the most effective way to improve the survival rate and increase more chances of breast-conserving. In this paper, we developed a label-free fluorescent biosensor based on nuclease assisted target recycling and Thioflavin T-induced quadruplex formation for short DNA species of c-erbB-2 detection in saliva. By employing the strategy, the sensor can detect as low as 20fM target DNA with high discrimination ability even against single-base mismatch sequence. To the best of our knowledge, the proposed sensor is the first attempt to apply Thioflavin T that possesses outstanding structural selectivity for G-quadruplex in DNA amplification techniques, which may represent a promising path toward direct breast cancer detection in saliva at the point of care.
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Global analysis of miRNA gene clusters and gene families reveals dynamic and coordinated expression.
Biomed Res Int
PUBLISHED: 01-17-2014
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To further understand the potential expression relationships of miRNAs in miRNA gene clusters and gene families, a global analysis was performed in 4 paired tumor (breast cancer) and adjacent normal tissue samples using deep sequencing datasets. The compositions of miRNA gene clusters and families are not random, and clustered and homologous miRNAs may have close relationships with overlapped miRNA species. Members in the miRNA group always had various expression levels, and even some showed larger expression divergence. Despite the dynamic expression as well as individual difference, these miRNAs always indicated consistent or similar deregulation patterns. The consistent deregulation expression may contribute to dynamic and coordinated interaction between different miRNAs in regulatory network. Further, we found that those clustered or homologous miRNAs that were also identified as sense and antisense miRNAs showed larger expression divergence. miRNA gene clusters and families indicated important biological roles, and the specific distribution and expression further enrich and ensure the flexible and robust regulatory network.
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Development and validation of a UPLC-MS/MS assay for the quantification of simotinib in human plasma.
Anal Bioanal Chem
PUBLISHED: 01-10-2014
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Simotinib is a novel oral small-molecule tyrosine kinase inhibitor that has demonstrated equal or superior antineoplastic activities to erlotinib in preclinical studies. In support of a clinical pharmacokinetic study, a sensitive and accurate liquid chromatography (LC) method with mass spectrometry detection using multiple reaction monitoring (MRM) in positive ion mode was developed and validated for the quantification of simotinib in human plasma. The sample preparation procedure involved a simple protein precipitation with methanol. Erlotinib was used as the internal standard. The optimal chromatographic behavior was achieved on a Zorbax SB-C8 column (2.1 mm?×?100 mm, 3.5 ?m) using a mixture of 0.1% formic acid with 10 mM ammonium formate/methanol (20:80, v/v) as the mobile phase. The total LC analysis time per injection was 4 min with a flow rate of 0.2 mL/min. The recovery was greater than 90% and no significant matrix effect was observed. The assay was validated over the concentration range of 1-1,000 ng/mL. The intra- and interday precision and accuracy of the quality control samples at low, medium, and high concentration levels showed at most 9.4% relative standard deviation (RSD) and -7.4 to 7.4% relative errors (RE). Assay selectivity, freeze/thaw stability, storage stability, and dilution effects were also assessed. The method is now used to support clinical pharmacokinetic studies in patients with non-small cell lung cancer (NSCLC) after oral administration of simotinib.
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A recombinant fusion protein containing a spider toxin specific for the insect voltage-gated sodium ion channel shows oral toxicity towards insects of different orders.
Insect Biochem. Mol. Biol.
PUBLISHED: 01-02-2014
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Recombinant fusion protein technology allows specific insecticidal protein and peptide toxins to display activity in orally-delivered biopesticides. The spider venom peptide ?-amaurobitoxin-PI1a, which targets insect voltage-gated sodium channels, was fused to the "carrier" snowdrop lectin (GNA) to confer oral toxicity. The toxin itself (PI1a) and an amaurobitoxin/GNA fusion protein (PI1a/GNA) were produced using the yeast Pichia pastoris as expression host. Although both proteins caused mortality when injected into cabbage moth (Mamestra brassicae) larvae, the PI1a/GNA fusion was approximately 6 times as effective as recombinant PI1a on a molar basis. PI1a alone was not orally active against cabbage moth larvae, but a single 30 ?g dose of the PI1a/GNA fusion protein caused 100% larval mortality within 6 days when fed to 3rd instar larvae, and caused significant reductions in survival, growth and feeding in 4th - 6th instar larvae. Transport of fusion protein from gut contents to the haemolymph of cabbage moth larvae, and binding to the nerve chord, was shown by Western blotting. The PI1a/GNA fusion protein also caused mortality when delivered orally to dipteran (Musca domestica; housefly) and hemipteran (Acyrthosiphon pisum; pea aphid) insects, making it a promising candidate for development as a biopesticide.
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Combined overexpression of genes involved in pentose phosphate pathway enables enhanced D-xylose utilization by Clostridium acetobutylicum.
J. Biotechnol.
PUBLISHED: 01-02-2014
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D-Xylose utilization by Clostridium acetobutylicum, an important industrial microorganism used in ABE (Acetone, Butanol and Ethanol) production, has attracted increasing interests. We demonstrated previously that co-overexpression of genes, encoding d-xylose symporter, D-xylose isomerase and xylulokinase, improved D-xylose utilization by C. acetobutylicum (Xiao, H., et al., 2011. Applied and Environmental Microbiology 77, 7886-7895). Here, we further identified genes involved in PPP (Pentose Phosphate Pathway) in C. acetobutylicum and evaluated their contribution to d-xylose utilization. Among all the candidate genes, the CAC1347, CAC1348, CAC1730 and CAC2880 were validated to encode genes tal, tkl, rpe and rpi, four key genes involved in PPP, respectively. The following combined overexpression of these genes conferred a significantly improved xylose-utilizing ability to the recombinant strain, reaching a solvent titer 42% higher than that of the wild-type strain. This finding offers a useful strategy to optimize d-xylose utilization by C. acetobutylicum.
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MicroRNA-122 triggers mesenchymal-epithelial transition and suppresses hepatocellular carcinoma cell motility and invasion by targeting RhoA.
PLoS ONE
PUBLISHED: 01-01-2014
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The loss of microRNA-122 (miR-122) expression is strongly associated with increased invasion and metastasis, and poor prognosis of hepatocellular carcinoma (HCC), however, the underlying mechanisms remain poorly understood. In the present study, we observed that miR-122 over-expression in HCC cell lines Sk-hep-1 and Bel-7402 triggered the mesenchymal-epithelial transition (MET), as demonstrated by epithelial-like morphological changes, up-regulated epithelial proteins (E-cadherin, ZO-1, ?-catenin, occludin, BVES, and MST4), and down-regulated mesenchymal proteins (vimentin and fibronectin). The over-expression of miRNA-122 also caused cytoskeleton disruption, RhoA/Rock pathway inactivation, enhanced cell adhesion, and suppression of migration and invasion of Sk-hep-1 and Bel-7402 cells, whereas, these effects could be reversed through miR-122 inhibition. Additional studies demonstrated that the inhibition of wild-type RhoA function induced MET and inhibited cell migration and invasion, while RhoA over-expression reversed miR-122-induced MET and inhibition of migration and invasion of HCC cells, suggesting that miR-122 induced MET and suppressed the migration and invasion of HCC cells by targeting RhoA. Moreover, our results demonstrated that HNF4? up-regulated its target gene miR-122 that subsequently induced MET and inhibited cell migration and invasion, whereas miR-122 inhibition reversed these HNF4?-induced phenotypes. These results revealed functional and mechanistic links among the tumor suppressors HNF4?, miR-122, and RhoA in EMT and invasive and metastatic phenotypes of HCC. Taken together, our study provides the first evidence that the HNF4?/miR-122/RhoA axis negatively regulates EMT and the migration and invasion of HCC cells.
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The Correlation of Expression Levels of HIF-1? and HIF-2? in Hepatocellular Carcinoma with Capsular Invasion, Portal Vein Tumor Thrombi and Patients Clinical Outcome.
Jpn. J. Clin. Oncol.
PUBLISHED: 12-26-2013
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The roles of hypoxia-inducible factor-1? and hypoxia-inducible factor-2? in the development of hepatocellular carcinoma have not been fully elucidated. Here, we aim to uncover the relationship between the prognosis of hepatocellular carcinoma patients and the expression of hypoxia-inducible factor-1? and hypoxia-inducible factor-2? in tumor tissues.
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[Development in molecular genetic manipulation of solventogenic clostridia].
Sheng Wu Gong Cheng Xue Bao
PUBLISHED: 12-25-2013
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Solventogenic clostridia are important industrial microorganisms. Optimization of the fermentation performance of solventogenic clostridia, through genetic modification, has always been considered as the main topic involved in solvents production. However, due to the incomplete genetic tools, no research breakthroughs have been achieved. In recent years, with the development of new technologies and methods (e.g. TargeTron gene knockout, large DNA fragment integration method), great progresses have been made towards genetic engineering solventogenic clostridia. In this review, we summarize the development of the genetic tools for solventogenic clostridial species, and simultaneously point out the shortages of the existing technologies in efficiency and comprehensiveness. Therefore, optimization of the existing technologies in gene inactivation in clostridia, such as establishing homologous exchange-based gene deletion and exchange, is still imperative; and in parallel, new genetic tools (e.g. multiplex genome editing, targeted or random multi-copy gene integration) should also be timely developed.
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New [ONOO]-Type Amine Bis(phenolate) Ytterbium(II) and -(III) Complexes: Synthesis, Structure, and Catalysis for Highly Heteroselective Polymerization of rac-Lactide.
Inorg Chem
PUBLISHED: 12-06-2013
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Two divalent ytterbium (Yb(II)) complexes, 1 and 2, supported by new [ONOO]-type amine bis(phenolate) ligands L(a,b) were synthesized in good yield by an amine elimination reaction of Yb(II)(N(SiMe3)2)2(TMEDA) (TMEDA = tetramethylethylenediamine) with one equivalent of the ligand precursor. X-ray structural determination showed complexes 1 and 2 both have a monomeric structure. Each adopts distorted octahedral coordination geometry around the six-coordinate Yb(II) ion. Two new trivalent ytterbium (Yb(III)) aryloxide complexes, 4 and 5, bearing [ONOO]-type amine bis(phenolate) ligands L(c) and L(d) were prepared by double-protonation reaction of Yb(C5H5)3THF with one equivalent of the ligand precursor, then one equivalent of phenol. Complex 4 has a symmetric dimeric structure with a Yb2O2 core bridging through the oxygen atoms of the OC6H4-4-CH3 groups. Complex 5 is a THF-solvated monomer. Each six-coordinated Yb(III) ion in both complexes adopts a distorted octahedron. All the complexes synthesized together with the known Yb(II) complex 3 were evaluated in the ring-opening polymerization (ROP) of rac-lactide (rac-LA). Complexes 1 and 4 were found to be extremely active for controlled ROP of rac-LA, as judged by narrow molar mass distributions (Mw/Mn: 1.07-1.16 for complex 1 and 1.07-1.10 for complex 4) and experimental molar mass Mn,exp values in good agreement with theoretic Mn,calcd values calculated on a single PLA chain produced per metal center of initiator. Complex 5 is less controlled. Complexes 1, 4, and 5 exhibited the same high stereoselectivity to give heterotactic polylactide with a Pr (probability of racemic enchainment of monomer units) ranging from 0.97 to 0.99. Dramatic decreases in activity and stereoselectivity were found for complexes 2 (Pr = 0.82) and 3 (Pr = 0.67), indicating the framework of L in the unit of [YbL] is crucial for determining activity and stereoselectivity of either Yb(II) or Yb(III) complexes.
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Self-assembly of graphene oxide with a silyl-appended spiropyran dye for rapid and sensitive colorimetric detection of fluoride ions.
Anal. Chem.
PUBLISHED: 11-14-2013
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Fluoride ion (F(-)), the smallest anion, exhibits considerable significance in a wide range of environmental and biochemical processes. To address the two fundamental and unsolved issues of current F(-) sensors based on the specific chemical reaction (i.e., the long response time and low sensitivity) and as a part of our ongoing interest in the spiropyran sensor design, we reported here a new F(-) sensing approach that, via assembly of a F(-)-specific silyl-appended spiropyran dye with graphene oxide (GO), allows rapid and sensitive detection of F(-) in aqueous solution. 6-(tert-Butyldimethylsilyloxy)-1,3,3-trimethylspiro [chromene- 2,2-indoline] (SPS), a spiropyran-based silylated dye with a unique reaction activity for F(-), was designed and synthesized. The nucleophilic substitution reaction between SPS and F(-) triggers cleavage of the Si-O bond to promote the closed spiropyran to convert to its opened merocyanine form, leading to the color changing from colorless to orange-yellow with good selectivity over other anions. With the aid of GO, the response time of SPS for F(-) was shortened from 180 to 30 min, and the detection limit was lowered more than 1 order of magnitude compared to the free SPS. Furthermore, due to the protective effect of nanomaterials, the SPS/GO nanocomposite can function in a complex biological environment. The SPS/GO nanocomposite was characterized by XPS and AFM, etc., and the mechanism for sensing F(-) was studied by (1)H NMR and ESI-MS. Finally, this SPS/GO nanocomposite was successfully applied to monitoring F(-) in the serum.
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An integrated evolutionary analysis of miRNA-lncRNA in mammals.
Mol. Biol. Rep.
PUBLISHED: 10-29-2013
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Increasing evidence suggests that non-coding RNAs have multiple important roles in transcriptional regulation, and also contribute to the expansion of genome complexity. Here, we attempted to perform an integrative analysis of miRNA-lncRNA in mammals to reveal their potential evolutionary relationships in transcriptional regulation network. The lncRNA of H19 gene includes an internal small non-coding RNA, miR-675. The H19 gene was conserved as well as the neighbor Igf2 coding gene and internal miR-675 gene, although they were involved in various location distributions and phylogenetic relationships. Both miR-675-5p/3p have been reported as potential negative regulatory molecules, but the canonical miRNA was more conserved than the passenger strand. These results implicated that the imprinted coding and non-coding gene cluster indicated similar evolutionary patterns. The lncRNA and internal miRNAs may have versatile roles in multiple biological processes, including in tumorigenesis as potential ncRNA regulatory molecules. The phylogenetical conservation of the imprinted cluster may be also derived from the functional implications and evolutionary pressures. The study will enrich the study of potential crosstalk of miRNA-lncRNA and mRNA-ncRNA.
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[Efficacy of chemotherapy after EGFR-TKIs resistance in 191 patients with Unknow EGFR gene mutation in advanced lung adenocarcinoma].
Zhongguo Fei Ai Za Zhi
PUBLISHED: 10-12-2013
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Subsequent chemotherapy were needed in patients with advanced pulmonary adenocarcinoma experiencing disease progression after epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) treatment. The study is to explore factors potentially influencing efficacy of subsequent chemotherapy.
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Integrated evolutionary analysis of human miRNA gene clusters and families implicates evolutionary relationships.
Gene
PUBLISHED: 09-19-2013
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Many microRNAs (miRNAs) are clustered on chromosomes and co-transcribed as polycistronic transcripts. Here, an integrated evolutionary analysis of human miRNA gene clusters and families was performed. Generally, miRNA gene clusters include 2-8 members, but some larger clusters have been found to have more members (over 40 miRNAs). 62.22% of them have been shown to be involved in homologous miRNA genes, including multicopy pre-miRNAs and sense/antisense homologous miRNAs. Multicopy pre-miRNAs can enrich the distribution and relationship between miRNA clusters and families. An miRNA family may be located in one or more clusters, and a cluster may be involved in one or more families. Members of different families have been shown to be prone to appear in clusters, and vice versa. Reconstructed phylogenetic trees and networks may indicate potential evolutionary relationships, which also indicate duplication history in specific related gene clusters and families. Related miRNA families are always found to share common target mRNAs and biological pathways. Some clusters containing non-homologous miRNAs also tend to be clustered together as well as homologous miRNAs. In the present work, it is shown that homologous miRNAs are prone to appear in clusters based on functional and evolutionary pressures. The phenomenon of miRNA clusters containing homologous or genetic relationships is quite common. The integrative evolutionary analysis will provide more potential evolutionary and functional relationships between homologous and clustered miRNAs.
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A one-pot system for production of L-2-aminobutyric acid from L-threonine by L-threonine deaminase and a NADH-regeneration system based on L-leucine dehydrogenase and formate dehydrogenase.
Biotechnol. Lett.
PUBLISHED: 09-16-2013
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L-2-Aminobutyric acid (L-ABA) is an unnatural amino acid that is a key intermediate for the synthesis of several important drugs. It can be produced by transaminase or dehydrogenase from ?-ketobutyric acid, which can be synthesized enzymatically from the bulk amino acid, L-threonine. Deamination of L-threonine followed by a hydrogenation reaction gave almost the theoretical yield and was estimated to be more cost-effective than the established chemical process. L-Threonine deaminase from Escherichia coli, L-leucine dehydrogenase from Bacillus cereus, and formate dehydrogenase from Pseudomonas sp. were over-expressed in E. coli and used for one-pot production of L-ABA with formate as a co-substrate for NADH regeneration. 30 mol L-threonine were converted to 29.2 mol L-ABA at 97.3 % of theoretical yield and with productivity of 6.37 g l(-1) h(-1) at 50 l. This process offers a promising approach to fulfil industrial requirements for L-ABA.
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Identification and Characterization of Human UDP-Glucuronosyltransferases Responsible for the Glucuronidation of Fraxetin.
Drug Metab. Pharmacokinet.
PUBLISHED: 09-10-2013
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  Fraxetin, a major constitute from traditional medicine plant Fraxinus rhynchophylla Hance (Oleaceae), have been found to possess multiple bioactivities. However, the metabolic pathway(s) of fraxetin in human tissues have not been reported yet. This study aimed to characterize the glucuronidation pathway(s) of fraxetin in human tissues. Fraxetin could be metabolized to two glucuronides in human liver microsomes (HLMs). These two glucuronides were biosynthesized and characterized as 7-O-glucuronide (7-O-G) and 8-O-glucuronide (8-O-G), respectively. UGT1A1, -1A6, -1A7, -1A8, -1A9 and -1A10 participated in the formation of 7-O-G, while the formation of 8-O-G was catalyzed selectively by UGT1A6 and UGT1A9. UGT1A9 showed the highest catalytic activities in the formation of 7-O-G and 8-O-G. Both kinetic characterization and inhibition assays demonstrated that UGT1A9 played important roles in fraxetin glucuronidations in HLMs, especially in the formation of the major metabolite 8-O-G. Furthermore, the intrinsic clearance of fraxetin in both human liver microsomes and UGT1A9 was greater than that of 7, 8-dihydroxylcoumarin, revealing that the addition of C-6 methoxy group lead to the higher metabolic clearance. In summary, the glucuronidation pathways of fraxetin in human liver microsomes were well-characterized, and UGT1A9 was the major isoform responsible for the glucuronidations of fraxetin.
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Comparative effects of sitagliptin and metformin in patients with type 2 diabetes mellitus: a meta-analysis.
Curr Med Res Opin
PUBLISHED: 09-05-2013
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Sitagliptin has been widely used in the treatment of type 2 diabetes mellitus (T2DM); however, the therapeutic efficacy of sitagliptin remains inconclusive in randomized controlled studies on T2DM in which metformin has served as a control.
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Selected isomiR expression profiles via arm switching?
Gene
PUBLISHED: 08-01-2013
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A mature miRNA may be generated from 5p or 3p arm of a hairpin precursor. The selection may be flexible via "arm switching". However, accumulating evidences suggest that both arms of many pre-miRNAs can yield mature functional miRNAs. Herein, we attempted to compare the isomiR expression profiles between the two arms through analyzing in-house and published small RNA deep sequencing datasets. Although many miR-#-5p and miR-#-3p have been reported as functional miRNAs, fewer miRNA pairs (11 and 6 pairs are collected in tumor and normal cells, respectively) are simultaneously identified as abundant miRNA species. According to isomiR types and dominant isomiR species, miR-#-5p and miR-#-3p show various isomiR expression profiles as well as diverse enrichment levels. IsomiR profiles of non-dominant arm are not well-conserved in 5 ends as well as isomiR profiles of dominant arm. If both the miR-#-5p and miR-#-3p are abundantly expressed, their isomiR expression profiles are always stable across different samples. Similar to diverse enrichment levels of miR-#-5p and miR-#-3p, the isomiR expression patterns may also be influenced by the phenomenon of "arm switching". The diverged isomiR expression profiles further enrich the complexity of multiple isomiRs, and complicate the coding-non-coding RNA regulatory network.
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A gold nanocarrier and DNA-metal ligation-based sensing ensemble for fluorescent assay of thiol-containing amino acids and peptides.
Chem. Commun. (Camb.)
PUBLISHED: 07-30-2013
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By engineering a gold nanoparticle and thymine-Hg(2+)-thymine-based hairpin DNA probe, a gold nanocarrier-based strategy for in vitro detection and live-cell imaging of thiol-containing amino acids/peptides was proposed.
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Comparing the performance of traditional non-treponemal tests on syphilis and non-syphilis serum samples.
Int J STD AIDS
PUBLISHED: 07-19-2013
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The goal of the present study was to determine the performance of two traditional non-treponemal tests for syphilis. Syphilis sera (n = 209) included different stages of disease, and control sera (n = 247) were from patients with tumours, leprosy, systemic lupus erythematosus, hepatitis, pregnant women and healthy individuals. Treponema pallidum ELISA, Treponema pallidum particle agglutination and rapid treponema-specific tests were used as gold standards. Rapid plasma reagin or toluidine red unheated serum test had a sensitivity and specificity of over 95%. False-negative reactions of rapid plasma reagin and toluidine red unheated serum test were observed mainly in primary and latent syphilis cases, and false-positive reactions were present in systemic lupus erythematosus, hepatitis-infected patients. Overall, both non-treponemal tests had high sensitivities and specificities making the assays attractive as screening tests for syphilis. When examined on WHO reference serum samples and based on lower limits of detection, non-treponemal tests were less sensitive than treponema-specific tests.
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High-dose therapy and autologous stem cell transplantation in peripheral T-cell lymphoma: treatment outcome and prognostic factor analysis.
Int. J. Hematol.
PUBLISHED: 06-11-2013
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Peripheral T-cell lymphoma (PTCL) carries a poor prognosis with conventional treatment. We retrospectively analyzed data from 45 patients with PTCL who received high-dose therapy and autologous stem cell transplantation (HDT/ASCT) from 1990 to 2008 in our center. Eighteen patients underwent HDT/ASCT in complete remission to induction chemotherapy (CR1), and 27 patients underwent HDT/ASCT in other disease statuses. The median follow-up was 113.5 months (range 52.6-261.0) for surviving patients. The 5-year overall survival (OS) and progression-free survival (PFS) were 64 and 60 %, respectively. The 5-year OS for patients in CR1 and in other disease statuses was 89 and 47 %, respectively (P = 0.002), and 5-year PFS was 83 and 43 % (P = 0.007). In the subgroup excluding anaplastic large cell lymphoma, patients transplanted in CR1 also had significantly better 5-year OS (82 vs. 37 %, P = 0.009) and PFS (82 vs. 33 %, P = 0.008) than those transplanted in other disease statuses. Multivariate analysis showed that CR1 status was the only significant prognostic factor for OS (P = 0.040) and PFS (P = 0.040). These results support the use of HDT/ASCT consolidation in CR1 for PTCL patients. Prospective randomized trials are necessary to confirm the efficacy of this approach.
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(E)-3-(3,4-Di-fluoro-phen-yl)-1-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one.
Acta Crystallogr Sect E Struct Rep Online
PUBLISHED: 06-01-2013
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In the title compound, C17H14F2O3, the dihedral angle between the benzene rings is 20.56?(8)° and the H atoms at the central propenone group are trans configured. One of the F atoms is disordered over two positions (occupancy ratio 0.57:0.43) and was refined using a split model. In the crystal, the molecules are linked into centrosymmetrical dimers and are further connected into a three-dimensional network via weak C-H?O interactions.
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Close association between paralogous multiple isomiRs and paralogous/orthologues miRNA sequences implicates dominant sequence selection across various animal species.
Gene
PUBLISHED: 05-15-2013
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MicroRNAs (miRNAs) are crucial negative regulators of gene expression at the post-transcriptional level. Next-generation sequencing technologies have identified a series of miRNA variants (named isomiRs). In this study, paralogous isomiR assemblies (from the miRNA locus) were systematically analyzed based on data acquired from deep sequencing data sets. Evolutionary analysis of paralogous (members in miRNA gene family in a specific species) and orthologues (across different animal species) miRNAs was also performed. The sequence diversity of paralogous isomiRs was found to be similar to the diversity of paralogous and orthologues miRNAs. Additionally, both isomiRs and paralogous/orthologues miRNAs were implicated in 5 and 3 ends (especially 3 ends), nucleotide substitutions, and insertions and deletions. Generally, multiple isomiRs can be produced from a single miRNA locus, but most of them had lower enrichment levels, and only several dominant isomiR sequences were detected. These dominant isomiR groups were always stable, and one of them would be selected as the most abundant miRNA sequence in specific animal species. Some isomiRs might be consistent to miRNA sequences in some species but not the other. Homologous miRNAs were often detected in similar isomiR repertoires, and showed similar expression patterns, while dominant isomiRs showed complex evolutionary patterns from miRNA sequences across the animal kingdom. These results indicate that the phenomenon of multiple isomiRs is not a random event, but rather the result of evolutionary pressures. The existence of multiple isomiRs enables different species to express advantageous sequences in different environments. Thus, dominant sequences emerge in response to functional and evolutionary pressures, allowing an organism to adapt to complex intra- and extra-cellular events.
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Derivation and genetic modification of embryonic stem cells from disease-model inbred rat strains.
Stem Cells Dev.
PUBLISHED: 05-03-2013
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The lack of rat embryonic stem cells (ESCs) and approaches for manipulation of their genomes have restricted the ability to create new genetic models and to explore the function of a single gene in complex diseases in the laboratory rat. The recent breakthrough in isolating germline-competent ESCs from rat and subsequent demonstration of gene knockout has propelled the field forward, but such tools do not yet exist for many disease-model rat strains. Here we derive new ESCs from several commonly used rat models including the Dahl Salt Sensitive (SS), the sequenced Brown Norway (BN), and Fischer (F344) rat and establish the first germline-competent ESCs from a hypertension disease model strain, the Fawn Hooded Hypertensive (FHH) rat. Genetic manipulations including transgenesis mediated by lentivirus, routine homologous recombination, and homologous recombination mediated by zinc-finger nucleases (ZFNs) were performed effectively in FHH rat ESCs. Our results showed these rat ESC lines, isolated from inner cell masses using mechanical splitting, had germline competency; the Pparg gene locus and homologous genomic region to the mouse Rosa26 locus can be targeted effectively in these rat ESCs. Furthermore, our results also demonstrated that ZFNs increased the efficiency of proper homologous recombination in FHH rat ESCs using targeting vectors with short homology arms. These rat ESC lines and advancements in genetic manipulation pave the way to novel genetic approaches in this valuable biomedical model species and for exploration of complex disease in these strains.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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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.