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Find video protocols related to scientific articles indexed in Pubmed.
[Establishment of archives of Schistosoma japonicum antibody indirect hemagglutination tests].
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
PUBLISHED: 10-28-2014
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To establish written and electronic archives of Schistosoma japonicum antibody indirect hemagglutination (IHA) tests.
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[Determination of chemical rank of three-dimensional fluorescence spectra using mathematical morphology method].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 10-02-2014
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The present paper firstly denoises the signal with morphological method, selecting sine-shaped structure element, using the morphological difference in waveform between the three-dimensional fluorescence and noise signal, then singular value decomposition is applied to the denoised data, and finally the chemical rank is determinated jointing eigenvalues and eigenvectors form singular value decomposition. This paper principally discusses the theory basis of morphological filtering method, firstly simulated data is analysed by morphological filtering method to confirm the necessity and effectiveness of proposed method, then the feasibility and practicability of the proposed method is verified by the determination of components number of phenols mixture three-dimensional fluorescence spectra compared with traditional Monte Carlo method. The experiments demonstrate that the proposed method is able to estimate the chemical rank correctly.
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[Analysis of three-dimensional fluorescence overlapping spectra using nonnegative matrix factorization].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 09-12-2014
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The present paper primarily tests and verifies the effect of NMF in blind source separation of three-dimensional simulative fluorescence spectra, and then four different computational algorithms (multiplicative iterative; alternating least square; second order method; projected gradient algorithm) were used in three practical phenolic compounds (cresol, phenol, thymol) overlapping fluorescence spectra to find out which nonnegatively constrained algorithms is the most efficient for fluorescence spectra unmixing. The experiments demonstrate that four ways have the normalized residuals below 0.06%, and alternating least square (ALS) is the best at both convergence behavior and robustness.
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Pyrolytic cavitation, selective adsorption and molecular recognition of a porous Eu(III) MOF.
Dalton Trans
PUBLISHED: 09-09-2014
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A channel-equipped metal-organic framework (1-pyr), resulting from the pyrolysis of [(CH3)2NH2]@[Eu2L3(HCOO)] (1) (L(2-) = isophthalate), showed the preferable absorption of CO2 and the Eu(III)-based emission quenched by aromatics.
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Increased urinary interleukin 22 binding protein levels correlate with lupus nephritis activity.
J. Rheumatol.
PUBLISHED: 08-01-2014
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Interleukin 22 (IL-22) plays an important role in the promotion of antimicrobial immunity. However, dysregulated IL-22 action leads to inflammation and is involved in autoimmune diseases, including systemic lupus erythematosus (SLE). IL-22 binding protein (IL-22BP) is a soluble inhibitory IL-22 receptor and may represent a crucial regulator of IL-22. We investigated the expression and potential significance of serum and urinary IL-22BP levels in patients with SLE.
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Estimating soil organic carbon content with visible-near-infrared (vis-NIR) spectroscopy.
Appl Spectrosc
PUBLISHED: 07-12-2014
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The selection of a calibration method is one of the main factors influencing measurement accuracy with visible-near-infrared (Vis-NIR, 350-2500 nm) spectroscopy. This study, based on both air-dried unground (DU) and air-dried ground (DG) soil samples, used nine spectral preprocessing methods and their combinations, with the aim to compare the commonly used partial least squares regression (PLSR) method with the new machine learning method of support vector machine regression (SVMR) to find a robust method for soil organic carbon (SOC) content estimation, and to further explore an effective Vis-NIR spectral preprocessing strategy. In total, 100 heterogeneous soil samples collected from Southeast China were used as the dataset for the model calibration and independent validation. The determination coefficient (R(2)), root mean square error (RMSE), residual prediction deviation (RPD), and ratio of performance to interquartile range were used for the model evaluation. The results of this study show that both the PLSR and SVMR models were significantly improved by the absorbance transformation (LOG), standard normal variate with wavelet detrending (SW), first derivative (FD), and mean centering (MC) spectral preprocessing methods and their combinations. SVMR obtained optimal models for both the DU and DG soil, with R(2), RMSE, and RPD values of 0.72, 2.48 g/kg, and 1.83 for DU soil and 0.86, 1.84 g/kg, and 2.60 for DG soil, respectively. Among all the PLSR and SVMR models, SVMR showed a more stable performance than PLSR, and it also outperformed PLSR, with a smaller mean RMSE of 0.69 g/kg for DU soil and 0.50 g/kg for DG soil. This study concludes that PLSR is an effective linear algorithm, but it might not be sufficient when dealing with a nonlinear relationship, and SVMR turned out to be a more suitable nonlinear regression method for SOC estimation. Effective SOC estimation was obtained based on the DG soil samples, but the accurate estimation of SOC with DU soil samples needs to be further explored. In addition, LOG, SW, FD, and MC are valuable spectral preprocessing methods for Vis-NIR optimization, and choosing two of them (except for FD + SW and LOG + FD) in a simple combination is a good way to get acceptable results.
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Acidity and Hydrogen Exchange Dynamics of Iron(II)-Bound Nitroxyl in Aqueous Solution.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 07-08-2014
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Nitroxyl-iron(II) (HNO-Fe(II) ) complexes are often unstable in aqueous solution, thus making them very difficult to study. Consequently, many fundamental chemical properties of Fe(II) -bound HNO have remained unknown. Using a comprehensive multinuclear ((1) H, (15) N, (17) O) NMR approach, the acidity of the Fe(II) -bound HNO in [Fe(CN)5 (HNO)](3-) was investigated and its pKa ?value was determined to be greater than 11. Additionally, HNO undergoes rapid hydrogen exchange with water in aqueous solution and this exchange process is catalyzed by both acid and base. The hydrogen exchange dynamics for the Fe(II) -bound HNO have been characterized and the obtained benchmark values, when combined with the literature data on proteins, reveal that the rate of hydrogen exchange for the Fe(II) -bound HNO in the interior of globin proteins is reduced by a factor of 10(6) .
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[Reconstructing habitat history of Larimichthys polyactis in Lüsi coastal waters of Jiangsu Province, China based on otolith microchemistry].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 07-03-2014
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An electron probe microanalyzer (EPMA) was applied to analyze the element Sr and Ca microchemistry patterns in otoliths of Larimichthys polyactis in Lüsi coastal waters of Jiangsu Province, China. The results showed that Sr was heterogeneously distributed along the sagittal plane of the otoliths. The highest Sr concentration was normally found in the otolith cores while much lower concentrations were found in the remaining areas. The corresponding Sr/Ca ratios were (7.10 +/- 1.00) and (4.79 +/- 1.01) in the former and latter, respectively, which were significantly differed (P < 0.01), but low Sr/Ca ratios even as low as (3.51 +/- 0.76) were also observed in several fish. Based on the above results of otolith microchemistry, the habitat history of L. polyactis was reconstructed as that high salinity habitats seemed to be required at the stages of hatching and post-hatching development, while the reduced salinity habitats seemed to be preferable for the growth and development at the remaining stages of the life history. Furthermore, several fish in this study had likely even experienced much lower salinity habitats at the early stages.
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Characterization of two UDP-Gal:GalNAc-diphosphate-lipid ?1,3-galactosyltransferases WbwC from Escherichia coli serotypes O104 and O5.
J. Bacteriol.
PUBLISHED: 06-23-2014
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Escherichia coli displays O antigens on the outer membrane that play an important role in bacterial interactions with the environment. The O antigens of enterohemorrhagic E. coli O104 and O5 contain a Gal?1-3GalNAc disaccharide at the reducing end of the repeating unit. Several other O antigens contain this disaccharide, which is identical to the mammalian O-glycan core 1 or the cancer-associated Thomsen-Friedenreich (TF) antigen. We identified the wbwC genes responsible for the synthesis of the disaccharide in E. coli serotypes O104 and O5. To functionally characterize WbwC, an acceptor substrate analog, GalNAc?-diphosphate-phenylundecyl, was synthesized. WbwC reaction products were isolated by high-pressure liquid chromatography and analyzed by mass spectrometry, nuclear magnetic resonance, galactosidase and O-glycanase digestion, and anti-TF antibody. The results clearly showed that the Gal?1-3GalNAc? linkage was synthesized, confirming WbwCECO104 and WbwCECO5 as UDP-Gal:GalNAc?-diphosphate-lipid ?1,3-Gal-transferases. Sequence analysis revealed a conserved DxDD motif, and mutagenesis showed the importance of these Asp residues in catalysis. The purified enzymes require divalent cations (Mn(2+)) for activity and are specific for UDP-Gal and GalNAc-diphosphate lipid substrates. WbwC was inhibited by bis-imidazolium salts having aliphatic chains of 18 to 22 carbons. This work will help to elucidate mechanisms of polysaccharide synthesis in pathogenic bacteria and provide technology for vaccine synthesis.
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[Study on a new method of fast monitoring toxicity of Cd2+ by algal in water].
Huan Jing Ke Xue
PUBLISHED: 06-21-2014
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Chlorophyll concentration and photosynthesis activity fluorescence parameters of Chlorella pyrenoidosa stressed by different concentrations of Cd2+ were measured based on algal growth inhibition tests and photosynthetic activity inhibition tests. The relationship between the algal photosynthetic activity inhibition rate and 96 h inhibition rate of specific growth rate at different Cd2+ stress times was studied by sigmoidal curve fitting and one-way ANOVA analysis. The result shows that S function relevance exists between the algal photosynthetic activity inhibition rates for 48 h, 53 h, 72 h, 77 h and 96 h respectively and 96 h inhibition rate of specific growth rate (R2 > 0.95). Consequently, EC10 (10% effective concentration) after 48 h and 53 h inhibition in photosynthetic activity inhibition tests could be used to represented EC50 (50% effective concentration) in 96 h algal growth inhibition tests for evaluating the Cd2+ toxicity. Dose-response relationships between the algal photosynthetic activity inhibition rates after 48 h and 53 h inhibition and Cd2+ toxic equivalency quantity were further analyzed. The method provided a rapid and viable new thought to monitoring single Cd2+ toxicity in lab and early warn integrated toxicity of pollution in water.
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Expression and effects of JMJD2A histone demethylase in endometrial carcinoma.
Asian Pac. J. Cancer Prev.
PUBLISHED: 05-13-2014
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Previous studies have demonstrated that JMJD2A is a potential oncogene and is overexpressed in human tumors. However, its role in the endometrial carcinoma remains largely unknown. In this study, we discovered that JMJD2A was overexpressed in endometrial carcinoma, using immunohistochemistry, quantitative real- time polymerase chain reaction, and western blotting. Downregulation of JMJD2A led to reduced endometrial carcinoma RL95-2 and ISK cell proliferation, invasion and metastasis as asessed with cell counting kit-8, cell migration and invasive assays. Collectively, our results support that JMJD2A is a promoter of endometrial carcinoma cell proliferation and survival, and is a potential novel drug target.
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Determination of a deuterohemin-peptide conjugate in rat plasma by liquid chromatography-tandem mass spectrometry and application to a preclinical pharmacokinetic study.
J Pharm Biomed Anal
PUBLISHED: 03-09-2014
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The deuterohemin-peptide conjugate (DhHP-6) is a microperoxidase mimetic, which has demonstrated substantial benefits in vivo as a scavenger of reactive oxygen species. This paper reports the development of a sensitive and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the determination of DhHP-6 in rat plasma using triptorelin as an internal standard (IS). 50?L plasma was used in sample preparation, and a simple protein precipitation procedure with acetonitrile was involved. Satisfactory peak shapes of analyte and IS were obtained on an Agilent HC-C18 column by using a gradient elution with 10mM ammonium acetate-0.5% formic acid (v:v) and acetonitrile, there was no significant interference impacting the determination. A calibration curve obtained from this method was linear within the concentration range 10-3000ng/mL with intra- and inter-day precisions of 4.2-6.8% and 3.2-8.9%, respectively and accuracy of -1.3% to 2.1%. The recovery was above 80% with low matrix effects. The method was successfully applied to support a preclinical pharmacokinetic study in rat.
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Interleukin-6 signal transduction and its role in hepatic lipid metabolic disorders.
Cytokine
PUBLISHED: 01-31-2014
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Hepatic lipid dysregulation can lead to spectrum of metabolic disease conditions including metabolic syndrome (MS), fatty liver and diabetes. Liver lipids are regulated by a complex set of extra-hepatic and intra-hepatic factors including cellular cross-talk with variety of cells, inducing various cytokines. Interleukin 6(IL-6) is a pleiotropic cytokine that exerts both pro-inflammatory and anti-inflammatory effects on hepatic system through either JNK/STAT or ERK/MAPK signaling. Although, IL-6 has shown to protect the liver from fat storage in both rodent and human models and various IL-6(-/-) studies have supported this notion yet a question remains over its deleterious pro-inflammatory effects on hepatocytes. IL-6 ability to produce reactive oxygen species (ROS) and subsequently disturb the hepatic lipid balance has created a conundrum. Furthermore, IL-6 has shown to behave differently under different disease states within hepatocytes and hence, modulating the hepatic lipids accordingly. This review deals with the role of IL-6 on hepatic lipid metabolism and analyzes various data presented on this topic.
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[The method of phytoplankton photosynthesis activity in-situ measurement based on light induced fluorescence].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 12-28-2013
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According to the phytoplankton fluorescence induction characteristics under different light conditions, chlorophyll fluorescence as a probe for analysis of phytoplankton photosynthesis was studied. The present paper proposed a in-situ measurement method based on the chlorophyll fluorescence values Ft and Fm to get phytoplankton photosynthesis activity, Chlorella vulgaris, microcystis aeruginosa and Cyclotella meneghiniana Kiits were selected as experimental subjects, a comparison test was done between self-developed in-situ measurement system and Water PAM in lab, and the results showed that coefficients between the two methods were 0.9778, 0.8786 and 0.7953. This work provides a rapid and in-situ measurement method for phytoplankton photosynthesis activity.
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Treatment outcomes of occult breast carcinoma and prognostic analyses.
Chin. Med. J.
PUBLISHED: 08-29-2013
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The surgical management of occult breast cancer is controversial. We compared the outcomes of different treatments of occult breast cancer and evaluated the potential prognostic factors for overall survival and recurrence.
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[Studies on toxicity of four kinds of heavy metals in water by synchronous-scan fluorescence].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 08-03-2013
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Spectrofluorometry of chlorella pyrenoidosa was studied by three dimensional excitation-emission (3DEEM) fluorescence spectroscopy and synchronous scan fluorescence spectroscopy with Delta gamma = 20 nm in the stress of Hg+, Cd2+, Cu2+ and Zn2+. The conclusion from two kinds of Spectrofluorometry was the same: after 96h stress by heavy metals, the maximum fluorescence values reduced obviously, chlorophyll-a and chlorophyll-b in the photosynthetic system were seriously damaged by heavy metal. Further analysis of the correlations between heavy metal concentration and fluorescence quenching efficiency I0/I can conclude that the toxicity of heavy metal and the fluorescence quenching efficiency I0/I were positively correlated, and they all increased with the heavy metal concentration and stress time. For one kind of heavy metals, synchronous scan fluorometry is a sensitive method for its toxicity assessment. Compared to 3DEEM fluorescence spectroscopy, synchronous scan fluorescence spectroscopy is less time consuming and of higher selectivity. It is suitable to assess the toxicity of pollutions in water.
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[Update of research on hyperthermia in relief of bone metastasis pain].
Zhongguo Gu Shang
PUBLISHED: 07-13-2013
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Hyperthermia is an efficient type of cancer treatment in which body tissue is exposed to high temperatures to damage and kill cancer cells. Previous studies have focused on the treatment of tumor, however,it can not substitute for traditional methols. In recent years,new research in shows hyperthermia plays an important role in bone metastasis pain control because of the advantages of width rang,rapid onset and noninvasive, and it is therefore well used in. It is also becoming one of classical methods for bone metastasis from cancer. This article reviews recent research and progress of mechanisms of hyperthermia in relief of bone metastasis pain.
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Functional identification of bacterial glucosyltransferase WbdN.
Methods Mol. Biol.
PUBLISHED: 06-15-2013
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The outer membrane of gram-negative bacteria is stabilized by lipopolysaccharides (LPS). The O-antigenic polysaccharides of LPS are composed of repeating units that are exposed to and can interact with the environment. The glycosyltransferases that assemble these repeating units are encoded by the O-antigen gene cluster and utilize undecaprenol-phosphate-linked intermediates as natural acceptor substrates, and nucleotide sugars as donor substrates on the cytoplasmic face of the inner membrane. Many of the glycosyltransferase genes are known but the enzymatic functions of most of them remain to be identified. We describe here how the function of a recombinant glucosyltransferase WbdN from Escherichia coli O157 can be determined by NMR analysis of the enzyme product, using a synthetic acceptor substrate analog. A fluorescent acceptor substrate analog can be used in highly sensitive enzyme assays that allow the characterization of enzyme activity without the use of radioactive nucleotide sugar donor substrates.
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Extranodal metastasis is a powerful prognostic factor in patients with adenocarcinoma of the esophagogastric junction.
J Surg Oncol
PUBLISHED: 06-13-2013
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The purpose of this study is to estimate the effect of extranodal metastasis (EM) on recurrence and survival in patients with adenocarcinoma of the esophagogastric junction (AEG) after curative resection.
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[A compression algorithm for multi-spectral TDICCD image].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 05-28-2013
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In order to solve the problem of edge and texture blurring of multi-spectral image caused by the wavelet transform and bit-plane encoder of traditional method not taking into account image characteristics, a compression algorithm of multi-spectral TDICCD image having few bands is proposed in the present paper. The proposed direction-adaptive lifting DWT can adaptively choose the best lifting direction and use the Lagrange interpolation technique to make prediction according to its local characteristics. This method makes good use of the image texture features. The proposed rate control algorithm can adaptively allocate the rate bits according to image content. The experiments results showed that the proposed compression algorithm has good compressive property. Compared with traditional approaches, the performance of our method corresponds to the conventional approach for smooth images. However, it was superior to others for images with rich texture and a large number of edge detail information. In the compression ration 4 : 1, the average peak signal to noise ratio of the proposed compression algorithmcould improve the average PSNR by 1.939 dB. They effectively protect the edge and texture detail information for multi-spectral image. It is very suitable for the application of space multi-spectral CCD image with rich texture and a large number of edge detail information.
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Apparent diffusion coefficient reproducibility of the pancreas measured at different MR scanners using diffusion-weighted imaging.
J Magn Reson Imaging
PUBLISHED: 04-19-2013
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To evaluate the reproducibility of the pancreatic apparent diffusion coefficient (ADC) measured at different MR scanners.
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[Analysis of three-dimensional fluorescence overlapping spectra using differential spectra and independent component analysis].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 04-17-2013
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The analysis of multi-component three-dimensional fluorescence overlapping spectra is always very difficult. In view of the advantage of differential spectra and based on the calculation principle of two-dimensional differential spectra, the three-dimensional fluorescence spectra with both excitation and emission spectra is fully utilized. Firstly, the excitation differential spectra and emission differential spectra are respectively computed after unfolding the three-dimensional fluorescence spectra. Then the excitation differential spectra and emission differential spectra of the single component are obtained by analyzing the multicomponent differential spectra using independent component analysis. In this process, the use of cubic spline increases the data points of excitation spectra, and the roughness penalty smoothing reduces the noise of emission spectra which is beneficial for the computation of differential spectra. The similarity indices between the standard spectra and recovered spectra show that independent component analysis based on differential spectra is more suitable for the component recognition of three-dimensional fluorescence overlapping spectra.
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Enzyme-substrate complexes of allosteric citrate synthase: Evidence for a novel intermediate in substrate binding.
Biochim. Biophys. Acta
PUBLISHED: 04-05-2013
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The citrate synthase (CS) of Escherichia coli is an allosteric hexameric enzyme specifically inhibited by NADH. The crystal structure of wild type (WT) E. coli CS, determined by us previously, has no substrates bound, and part of the active site is in a highly mobile region that is shifted from the position needed for catalysis. The CS of Acetobacter aceti has a similar structure, but has been successfully crystallized with bound substrates: both oxaloacetic acid (OAA) and an analog of acetyl coenzyme A (AcCoA). We engineered a variant of E. coli CS wherein five amino acids in the mobile region have been replaced by those in the A. aceti sequence. The purified enzyme shows unusual kinetics with a low affinity for both substrates. Although the crystal structure without ligands is very similar to that of the WT enzyme (except in the mutated region), complexes are formed with both substrates and the allosteric inhibitor NADH. The complex with OAA in the active site identifies a novel OAA-binding residue, Arg306, which has no functional counterpart in other known CS-OAA complexes. This structure may represent an intermediate in a multi-step substrate binding process where Arg306 changes roles from OAA binding to AcCoA binding. The second complex has the substrate analog, S-carboxymethyl-coenzyme A, in the allosteric NADH-binding site and the AcCoA site is not formed. Additional CS variants unable to bind adenylates at the allosteric site show that this second complex is not a factor in positive allosteric activation of AcCoA binding.
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Structural transitions in mixed ternary noble gas clusters.
J Mol Model
PUBLISHED: 04-02-2013
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The properties of noble gas systems can be greatly extended by heterogeneous mixtures of elements. The geometrical structures and energies of mixed Ar-Kr-Xe clusters were investigated using ternary Lennard-Jones (TLJ) potential. For the Ar19Kr n Xe19, Ar19Kr19Xe n , and Ar n Kr19Xe19 (n?=?0-17) clusters investigated, the results show that only two minimum energy configurations exist, i.e., polytetrahedron and six-fold pancake. The inner core of all these clusters is composed mainly of Ar atoms, and Kr and Xe atoms are distributed on the surface with well mixed pattern for polytetrahedral and segregate pattern for six-fold pancake configurations. The relative stability property of Ar-Kr-Xe clusters with a certain composition is discussed. Moreover, the role of heterogeneity on the strain was investigated, and reduced strain energies in Ar-Kr-Xe clusters were studied to find possible ways of reducing strain. The results showed that the strain energies were affected mainly by Ar-Ar, Ar-Kr, and Xe-Xe bonds.
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dBre1/dSet1-dependent pathway for histone H3K4 trimethylation has essential roles in controlling germline stem cell maintenance and germ cell differentiation in the Drosophila ovary.
Dev. Biol.
PUBLISHED: 03-27-2013
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The Drosophila ovarian germline stem cells (GSCs) constantly experience self-renewal and differentiation, ensuring the female fertility throughout life. The balance between GSC self-renewal and differentiation is exquisitely regulated by the stem cell niche, the stem cells themselves and systemic factors. Increasing evidence has shown that the GSC regulation also involves epigenetic mechanisms including chromatin remodeling and histone modification. Here, we find that dBre1, an E3 ubiquitin ligase, functions in controlling GSC self-renewal and germ cell differentiation via distinct mechanisms. Removal or knock down of dBre1 function in the germline or somatic niche cell lineage leads to a gradual GSC loss and disruption of H3K4 trimethylation in the Drosophila ovary. Further studies suggest that the defective GSC maintenance is attributable to compromised BMP signaling emitted from the stem cell niche and impaired adhesion of GSCs to their niche. On the other hand, dBre1-RNAi expression in escort cells causes a loss of H3K4 trimethylation and accumulation of spectrosome-containing single germ cells in the germarium. Reducing dpp or dally levels suppresses the germ cell differentiation defects, indicating that dBre1 limits BMP signaling activities for the differentiation control. Strikingly, all phenotypes observed in dBre1 mutant ovaries can be mimicked by RNAi-based reduced expression of dSet1, a Drosophila H3K4 trimethylase. Moreover, genetic studies favor that dBre1 interacts with dSet1 in controlling GSC maintenance and germ cell differentiation. Taken together, we identify a dBre1/dSet1-dependent pathway for the H3K4 methylation involved in the cell fate regulation in the Drosophila ovary.
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Acceptor specificities and selective inhibition of recombinant human Gal- and GlcNAc-transferases that synthesize core structures 1, 2, 3 and 4 of O-glycans.
Biochim. Biophys. Acta
PUBLISHED: 01-03-2013
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Modifications of proteins by O-glycosylation determine many of the properties and functions of proteins. We wish to understand the mechanisms of O-glycosylation and develop inhibitors that could affect glycoprotein functions and alter cellular behavior.
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Selective inhibition of glycosyltransferases by bivalent imidazolium salts.
Bioorg. Med. Chem.
PUBLISHED: 01-03-2013
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Galactosyltransferases (GalTs) extend the glycan chains of mammalian glycoproteins by adding Gal to terminal GlcNAc residues, and thus build the scaffolds for biologically important glycan structures. We have shown that positively charged bivalent imidazolium salts in which the two imidazolium groups are linked by an aliphatic chain of 20 or 22 carbons form potent inhibitors of purified human ?3-GalT5, using GlcNAc?-benzyl as acceptor substrate. The inhibitors are not substrate analogs and also inhibited a selected number of other glycosyltransferases. These bis-imidazolium compounds represent a new class of glycosyltransferase inhibitors with potential as anti-cancer and anti-inflammatory drugs.
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[Randomized controlled study on electroacupuncture compound anesthesia in radiofrequency ablation for hypertrophic inferior turbinate].
Zhongguo Zhen Jiu
PUBLISHED: 07-12-2011
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To explore the feasibility of electroacupuncture compound anesthesia in radiofrequency ablation for hypertrophic inferior turbinate.
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Inhibition of the NADPH oxidase regulates heme oxygenase 1 expression in chronic myeloid leukemia.
Cancer
PUBLISHED: 05-31-2011
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Patients with chronic myelogenous leukemia (CML) in blast crisis have a poor response to tyrosine kinase inhibitors designed to inhibit the breakpoint cluster region-v-Abelson murine leukemia viral oncogene homolog 1 (BCR-ABL1) oncogene. Recent work has demonstrated that heme oxygenase 1 (HO-1) expression is increased in BCR-ABL1-expressing cells and that the inhibition of HO-1 in CML leads to reduced cellular growth, suggesting that HO-1 may be a plausible target for therapy. The objective of the current study was to clarify the mechanism of HO-1 overexpression and the role of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase as a contributor to this mechanism in CML.
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[Predictive value of serum uric acid on type 2 diabetes mellitus].
Zhonghua Liu Xing Bing Xue Za Zhi
PUBLISHED: 05-12-2011
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To evaluate the predictive value of uric acid (UA) on type 2 diabetes mellitus (DM).
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Changes of color and blood flow of the tongue in the mini-swine of immune hepatic injury.
J Tradit Chin Med
PUBLISHED: 12-07-2010
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To investigate color and microvascular blood flow of the tongue in the mini-swine with immune hepatic injury.
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[Experimental studies on three-dimensional fluorescence spectral of mineral oil in ethanol].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 08-17-2010
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Three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy was applied to characterize the mineral oil in ethanol. In the paper, a simple way of treating the first-order Rayleigh, Raman and second-order Rayleigh scatter is used involving subtracting an EEM of a solvent blank, and removing and replacing the values with zeros. The corrected results showed that the characteristic three-dimensional fluorescence spectra of mineral oil were as follows: there was one mainly peak in the fluorescence spectrum of the kerosene, and the peak was identified at excitation/emission wavelengths (Ex/Em) of 270/290 nm; there were two intense fluorescence peaks in the fluorescence spectrum of 0 # diesel, located at (Ex/Em) of 240/344 nm and 270/362 nm respectively; there were several fluorescence peaks in the fluorescence spectrum of lubricating oil, with the two intense peaks located at (Ex/Em) of 240/348 nm and 258/358 nm respectively. Furthermore, the relation between the relative fluorescence intensity and the concentration of mineral oil was studied, and the sensitivity and the limitation of detection of the method were also analyzed. The results of this study show that the method of three-dimensional fluorescence can be used to detect the low concentration of oil.
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Rapid and simultaneous determination of essential minerals and trace elements in human milk by improved flame atomic absorption spectroscopy (FAAS) with microwave digestion.
J. Agric. Food Chem.
PUBLISHED: 08-11-2010
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A method for the simultaneous and economical determination of many trace elements in human milk is developed. Two multi-element hollow cathode lamps (HCLs) were used instead of single-element HCLs to improve the sample throughput of flame atomic absorption spectroscopy (FAAS). The microwave digestion of milk is optimized prior to detection, and the performance characteristics of the improved analysis method are identified. Clinical samples are detected by both FAAS and inductively coupled plasma-optical emission spectroscopy (ICP-OES) for methodology evaluation. Results reveal that the proposed FAAS with multi-element HCLs could determine six essential minerals and trace elements within 15 min. This method provides a linear analytical range of 0.01-10 mg L(-1). For Ca, Cu, Fe, Mg, Mn, and Zn, the limits of determination are 1.5, 3, 1.8, 2.2, 2.1, and 1.3 microg L(-1), respectively. The mean relative standard deviations (RSDs) of intra- and interassays are lower than 7%. Excellent operational characteristics of rapidity, simplicity, and economy make the proposed method a promising one for the quantification of trace elements in human milk in clinics of underdeveloped areas.
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[Excitation-emission fluorescence characterization study of the three phenolic compounds].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 08-03-2010
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The fluorescence intensity information was collected by scanning its fluorescence spectra at different excitation wavelengths. Based on its high sensitivity and selectivity, excitation-emission fluorescence can be widely used for detection of pollutants in the environment. The characterizations of the three phenolic compounds were investigated by this method, and the fluorescence peaks of phenol, m-cresol and thymol were confirmed at 272/300 nm, 274/300 nm and 276/304 nm when the excitation and emission wavelength were set in the range of 240-360 nm and 260-500 nm respectively. The excitation and emission spectra of the three phenolic compounds are very similar because of their analogical structure. The intensity of the spectrum has a good linear relationship with the concentration when the solution concentration is between 0.02 and 1.0 mg x L(-1), and the limits of detection can reach at 1 microg x L(-1). Results show that the three compounds can be analyzed qualitatively and quantitatively by excitation-emission fluorescence.
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Specificity of ?1,4-galactosyltransferase inhibition by 2-naphthyl 2-butanamido-2-deoxy-1-thio-?-D-glucopyranoside.
Glycoconj. J.
PUBLISHED: 06-23-2010
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Inhibitors of Galactosyltransferase (GalT) have the potential of reducing the amounts of adhesive carbohydrates on secreted and cell surface-bound glycoproteins. We recently found a potent inhibitor of ?4GalT, 2-naphthyl 2-butanamido-2-deoxy-1-thio-?-D-glucopyranoside (compound 612). In this work, we have tested compound 612 for the specificity of its inhibition and examined its effect on GalT, and on GlcNAc- and GalNAc-transferases in homogenates of different cell lines, as well as on recombinant glycosyltransferases. Compound 612 was found to be a specific inhibitor of ?4GalT. The specificity of recombinant human ?3GalT5 that also acts on GlcNAc-R substrates, revealed similarities to bovine milk ?4GalT. However, 612 was a poor substrate and not an inhibitor for ?3GalT5. To further determine the specific structures responsible for the inhibitory property of 612, we synthesized (2-naphthyl)-2-butanamido-2-deoxy-?-D-glucopyranosylamine (compound 629) containing nitrogen in the glycosidic linkage, and compared it to other naphthyl and quinolinyl derivatives of GlcNAc as substrates and inhibitors. Compound 629 was a substrate for both ?4GalT and ?3GalT5. This suggests that properties of 612 other than the presence of the naphthyl ring alone were responsible for its inhibitory action. The results suggest a usefulness of 612 in specifically blocking the synthesis of type 2 chains and thus epitopes attached to type 2 chains. In addition, 612 potently inhibits ?4GalT in cell homogenates and thus allows assaying ?3GalT activity in the presence of ?4GalT.
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Identification of gibberellin acid-responsive proteins in rice leaf sheath using proteomics.
Front Biosci (Landmark Ed)
PUBLISHED: 06-03-2010
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The phytohormone gibberellin acid (GA) controls many aspects of plant development. In this study, we identified proteins that are differentially expressed between the rice (Oryza sativa L.) GA-deficient cultivar, Aijiaonante, and its parental line, Nante. Proteins were extracted from rice leaf sheath and examined by 2DGE. Among more than 1200 protein spots reproducibly detected on each gel, 29 were found to be highly up-regulated by GAs in Nante, and 6 were down-regulated by GAs in Aijiaonante. These 35 proteins were identified by MALDI-TOF MS and were classified into three groups based on their putative function in metabolism, stress/defense processes and signal transduction. These data suggest that metabolic pathways are the main target of regulation by GAs during rice development. Our results provide new information about the involvement of GAs in rice development.
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[Analysis on the superiority of compound acupuncture anesthesia for thyroid ablation].
Zhen Ci Yan Jiu
PUBLISHED: 12-03-2009
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In the present paper, the authors compare the fits and unfit of different anesthetic methods for thyroid ablation and try to find a better one for it according to their own clinical practice and other scholars experience. Results indicate that any anesthetic method has its own advantages and disadvantages, while compound acupuncture anesthesia for thyroid surgery is of prominent preponderance not only in the analgesic effect but also in fewer side-effects and less physiological interference. Thus, compound acupuncture anesthesia is a reliable and better anesthetic method for thyroid operation in clinic.
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[Quantitative analysis of phenanthrene and humic acid in solution based on fluorescence method].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 10-21-2009
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Polycyclic aromatic hydrocarbons as a universal concern in the monitoring of priority pollutants have low content in the water environment and are interfered with the coexistence of humic acid. The spectra of humic acid and polycyclic aromatic hydrocarbons overlap seriously, so it was difficult to use the conventional methods for rapid quantitative detection. As a model compound of polycyclic aromatic hydrocarbons, Phenanthrene (PHE) was chosen in the experiment. The fluorescence spectra of PHE and humic acid (HA) were investigated by three dimensional fluorescence excitation-emission matrix. The method combined excitation-emission matrix fluorescence spectra with parallel factor analysis and was applied to determine PHE and HA directly. The excitation wavelength changed from 240 to 360 nm at an interval of 5 nm. The emission wavelength varied from 260 to 575 nm at an interval of 5 nm. The satisfactory results show that this experiment can be easily performed without paying out time-consuming and complicated procedures.
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Toll-like receptor 4-mediated myeloid differentiation factor 88-dependent signaling pathway is activated by cerebral ischemia-reperfusion in hippocampal CA1 region in mice.
Biol. Pharm. Bull.
PUBLISHED: 10-06-2009
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The Toll-like receptor 4 (TLR4)-mediated myeloid differentiation factor 88 (MyD88)-dependent signaling pathway plays an essential role in inflammation resulting from invading microbes. However, whether the signaling pathway is activated in the inflammatory reaction of cerebral ischemia-reperfusion and its mechanism is still unclear. In this experiment mice were randomly divided into sham group, ischemia/reperfusion group and TLR4-blocked group with different time points of reperfusion at 12, 24, 48 and 72 h . Mice cerebral ischemia was induced by occlusion of common carotid arteries (CCA) bilaterally. TLR4 signaling pathway was inhibited using specific anti-TLR4 binding protein to prevent TLR4 from interacting with its receptors. We determined the result of TLR4 antibodies-blocking and mice cerebral ischemia-reperfusion injuries by Western blot, and evaluated neuronal damage in the hippocampus. We also determined expression of TLR4 mRNA and MyD88 mRNA by in situ hybridization (ISH), activation of nuclear factor (NF)-kappaB by electrophoretic mobility-shift analysis (EMSA), and expression of interrleukin (IL)-1beta protein by Western blot. The results demonstrated that TLR4-mediated MyD88-dependent signaling pathway activated by ischemia-reperfusion may be involved in the mechanism of ischemia-reperfusion through upregulation of NF-kappaB, IL-1beta.
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Responses in the morphology, physiology and biochemistry of Taxus chinensis var. mairei grown under supplementary UV-B radiation.
J. Photochem. Photobiol. B, Biol.
PUBLISHED: 09-23-2009
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The effects of supplemental UV-B radiation on Taxus chinensis var. mairei were studied. Leaf traits, gas exchange parameters and the concentrations of photosynthetic pigments, cellular defense system products, secondary metabolites and ultrastructure were determined. UV-B radiation significantly decreased leaf area (p<0.05). Leaf number, secondary branch number, leaf weight per plant and leaf moisture all increased dramatically (p<0.05). Neither the leaf weight nor the specific leaf weight (SLW) exhibited significant differences between ambient and enhanced UV-B radiation. Gas exchange parameters were all dramatically reduced by enhanced UV-B radiation (p<0.05). The contents of chlorophyll and the chlorophyll a/b ratio were not distinctly affected by UV-B radiation, while carotenoids content significantly decreased (p<0.05). Supplemental UV-B treatment induced significant flavonoid accumulation (p<0.05), which was able to protect plant from radiation damage. Meanwhile, the appendage content, abaxial stomatal density, papilla density and particulate matter content in substomatic chambers increased noticeably by supplemental UV-B radiation, whereas the aperture size of single stomata was diminished. The number and area of plastoglobuli were apparently reduced by UV-B radiation, but stroma and grana lamellae were not destroyed. Our results demonstrated that T. chinensis var. mairei can activate several defense mechanisms against oxidative stress injury caused by supplemental UV-B radiation.
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TLR4-mediated MyD88-dependent signaling pathway is activated by cerebral ischemia-reperfusion in cortex in mice.
Biomed. Pharmacother.
PUBLISHED: 09-17-2009
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To study whether the signaling pathway is activated in the inflammatory reaction of cerebral ischemia-reperfusion and its mechanism. The mice were randomly divided into sham group, ischemia-reperfusion group and TLR4-blocked group with different time points of reperfusion 12h, 24h, 48h and 72h group. We observed the different expression of TLR4 mRNA and MyD88 mRNA, activation of NF-kappaB and the TNF-alpha and IL-1beta protein levels in each group at different time point after ischemia-reperfusion. Mice cerebral ischemia was induced by occlusion of common carotid arteries (CCA) bilaterally. TLR4 signaling pathway could be inhibited by specific anti-TLR4 binding protein to prevent TLR4 from interacting with its receptors. We determined the result of TLR4 antibodies-blocking and mice cerebral ischemia-reperfusion injuries by Western blot, and evaluated neuronal damage in cortex. We also determined the expression of TLR4 mRNA and MyD88 mRNA by in situ hybridization (ISH), the activation of NF-kappaB by EMSA, and the expression of TNF-alpha protein by Western blot. Anti-TLR4 binding TLR4 receptors before reperfusion was effective; There was distinct difference among each group respecting neuronal damage; The expression of TLR4 mRNA and MyD88 mRNA, the activation of NF-kappaB, and the expression of TNF-alpha protein showed clear difference as well. LR4-mediated MyD88-dependent signaling pathway activated by ischemia-reperfusion may be involved in the mechanism of ischemia-reperfusion through upregulation of NF-kappaB and TNF-alpha.
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[Study on three-dimensional fluorescence spectra of phenanthrene].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 08-05-2009
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According to the high fluorescence quantum yields of polycyclic aromatic hydrocarbons (PAHs), the fluorescence spectra of phenanthrene were investigated by three dimensional fluorescence excitation-emission matrix (3DEEM). The results show that the three-dimensional fluorescence spectra of phenanthrene in aqueous solution mainly have two fluorescence peaks. On the basis of three-dimensional fluorescence spectrometry analysis of phenanthrene, the excitation wavelength of 255 nm and emission wavelength of 273 nm were chosen for the quantitative analysis of phenanthrene. The linear range for the determination of phenanthrene was 5.0-250.0 mg x mL(-1), its detection limit was 3. 88 ng x mL(-1), and its relative standard deviation was 4.23% (n=5). It was a good precision. It has been tested satisfactorily for the determination of artificial sample in tap water. The recoveries are in the range of 90%-105%. The method provided basis for the rapid monitoring of trace PAHs in water.
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Role of Scrib and Dlg in anterior-posterior patterning of the follicular epithelium during Drosophila oogenesis.
BMC Dev. Biol.
PUBLISHED: 06-09-2009
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Proper patterning of the follicle cell epithelium over the egg chamber is essential for the Drosophila egg development. Differentiation of the epithelium into several distinct cell types along the anterior-posterior axis requires coordinated activities of multiple signaling pathways. Previously, we reported that lethal(2)giant larvae (lgl), a Drosophila tumor suppressor gene, is required in the follicle cells for the posterior follicle cell (PFC) fate induction at mid-oogenesis. Here we explore the role of another two tumor suppressor genes, scribble (scrib) and discs large (dlg), in the epithelial patterning.
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Efficient LEC2 activation of OLEOSIN expression requires two neighboring RY elements on its promoter.
Sci. China, C, Life Sci.
PUBLISHED: 04-16-2009
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As the main structural protein of oil body, OLEOSIN is highly expressed only during seed development. OLEOSIN promoter is a very useful tool for seed-specific gene engineering and seed bioreactor designing. The B3 domain transcription factor leafy cotyledon2 (LEC2) plays an important role in regulating seed development and seed-specific gene expression. Here, we first report how seed-specific B3 domain transcription factor leafy cotyledon2 (LEC2) efficiently activates OLEOSIN expression. The central promoter region of OLEOSIN, responsible for seed specificity and LEC2 activation, was determined by 5-deletion analysis. Binding experiments in yeast cells and electrophoretic mobility shift assays showed that LEC2 specifically bound to two conserved RY elements in this region. In transient expression assays, mutation in either RY element dramatically reduced LEC2 activation of OLEOSIN promoter activity, while double mutation abolished it. Analysis of the distribution of RY elements in seed-specific genes activated by LEC2 also supported the idea that genes containing neighboring RY elements responded strongly to LEC2 activation. Therefore, we conclude that two neighboring RY elements are essential for efficient LEC2 activation of OLEOSIN expression. These findings will help us better utilize seed-specific promoter activity.
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Soluble expression and one-step purification of a neurotoxin Huwentoxin-I in Escherichia coli.
Protein Expr. Purif.
PUBLISHED: 01-17-2009
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Huwentoxin-I (HWTX-I) is a small 33-amino acid neurotoxin from the venom of the Chinese bird spider Ornithoctonus huwena. HWTX-I selectively blocks N-type voltage-sensitive calcium channels (N-VSCCs) and has great potential for clinical application as a novel analgesic without inducing drug tolerance. However, there are still many unsolved issues for this peptide, such as its clinical efficacy in analgesia, anesthesia, and even its potential role in drug rehabilitation. Therefore, large amounts of active recombinant HWTX-I are urgently needed. In this report, we describe a novel and efficient way to produce large amounts of the valuable form in Escherichia coli. HWTX-I was expressed in soluble form as an N-terminal intein fusion product. After affinity purification, a pH shift-induced self-cleavage of the intein released HWTX-I, resulting in a single-column purification of the target protein. The whole-cell patch clamp assay showed that purified HWTX-I has activity similar to another commercialized N-VSCC blocker omega-conotoxin MVIIA. Production of HWTX-I by this method has the major advantages of high efficiency and low cost.
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Oxidative stress promotes transcriptional up-regulation of Fyn in BCR-ABL1-expressing cells.
J. Biol. Chem.
PUBLISHED: 01-08-2009
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Signaling initiated by the BCR-ABL1 kinase causes chronic myelogenous leukemia (CML). Recently, we reported that expression of Fyn, a Src kinase, is heightened in CML cells and patient specimens and confers in vitro and in vivo proliferative advantages. Fyn is regulated by redox, and because BCR-ABL1 raises intracellular oxidant levels, which have been implicated in CML progression, we explored the molecular regulation of Fyn. Here we identify the transcription factors that drive redox- and BCR-ABL1-dependent Fyn expression. Promoter deletion analysis in 293T, BaF3, BaF3-p210, and K562 cells identified the region essential for basal transcriptional activity. Mutation of Sp1 and Egr1 binding sites within the essential region diminished Fyn promoter activity and identified Egr1 as conferring redox sensitivity. Gel shift and chromatin immunoprecipitation assays confirmed the binding of Sp1 and Egr1 to the promoter fragments. Importantly, knockdown of Sp1 or Egr1 with small interference RNA or inhibition of Sp1 binding by mithramycin A repressed Fyn protein expression. Our work is the first to define transcription factors that are responsible for endogenous, oxidative stress-dependent and BCR-ABL1-dependent Fyn expression.
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Expression and activity of Fyn mediate proliferation and blastic features of chronic myelogenous leukemia.
PLoS ONE
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The BCR-ABL1 oncogene is a tyrosine kinase that activates many signaling pathways, resulting in the induction of chronic myeloid leukemia (CML). Kinase inhibitors, such as imatinib, have been developed for the treatment of CML; however, the terminal, blast crisis phase of the disease remains a clinical challenge. Blast crisis CML is difficult to treat due to resistance to tyrosine kinase inhibitors, increased genomic instability and acquired secondary mutations. Our recent studies uncovered a role for Fyn in promoting BCR-ABL1 mediated cell growth and sensitivity to imatinib. Here we demonstrate that Fyn contributes to BCR-ABL1 induced genomic instability, a feature of blast crisis CML. Bone marrow cells and mouse embryonic fibroblasts derived from Fyn knockout mice transduced with BCR-ABL1 display slowed growth and clonogenic potential as compared to Fyn wild-type BCR-ABL1 expressing counterparts. K562 cells overexpressing constitutively active Fyn kinase were larger in size and displayed an accumulation of genomic abnormalities such as chromosomal aberrations and polyploidy. Importantly, loss of Fyn protected mouse embryonic fibroblast cells from increased number of chromosomal aberrations and fragments induced by BCR-ABL1. Together, these results reveal a novel role for Fyn in regulating events required for genomic maintenance and suggest that Fyn kinase activity plays a role in the progression of CML to blast crisis.
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Hypoxia-inducible factor-1? overexpression indicates poor clinical outcomes in tongue squamous cell carcinoma.
Exp Ther Med
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The aim of the present study was to investigate the expression of hypoxia-inducible factor-1? (HIF-1?) in tongue squamous cell carcinoma (TSCC) and to assess its possible impact on prognosis. A total of 49 tumor samples and 15 adjacent non-tumor samples from 49 patients treated between January 2000 and December 2005 at the Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, Tongji University (Shanghai, China) were obtained for investigation with immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). The expression of HIF-1? was detected in 87.76% (43/49) of the TSCC samples and in 33.33% (5/15) of the adjacent non-tumor tissues. The expression of vascular endothelial growth factor (VEGF) was also observed in 83.67% (41/49) of the TSCC samples and in only 20% (3/15) of the adjacent non-tumor samples at a low level. RT-PCR revealed that the mRNA expression of HIF-1? and VEGF was present in the tumor tissues; however, it was barely detected in the corresponding adjacent normal tissues. The overexpression of HIF-1? was significantly associated with T classification (P=0.01), lymphatic metastasis (P=0.05) and histological differentiation (P<0.001). Furthermore, HIF-1? overexpression was significantly associated with poor overall (P=0.001) and disease-free survival rates (P=0.01), independent of T stage and lymphatic metastasis. The Cox proportional hazards regression model demonstrated that the level of HIF-1? expression may be an independent prognostic factor for TSCC. HIF-1? overexpression was observed in TSCC and its overexpression suggests a poor prognosis. HIF-1? may be a molecular marker for predicting the prognosis of TSCC.
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Hydrothermal synthetic mercaptopropionic acid stabled CdTe quantum dots as fluorescent probes for detection of Ag?.
Spectrochim Acta A Mol Biomol Spectrosc
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Mercaptopropionic acid (MPA) capped CdTe quantum dots (QDs) with particle size 3 nm have been successfully synthesized in aqueous medium by hydrothermal synthesis method. And the effects of different metal ions on MPA capped CdTe QDs fluorescence were studied using fluorescence spectrometry. The results demonstrated that at the same concentration level, Ag(+) could strongly quench CdTe QDs fluorescence, and the other metal ions had little effect on CdTe QDs fluorescence except Cu(2+). On the basis of this fact, a rapid, simple, highly sensitive and selective method based on fluorescence quenching principle for Ag(+) detection in aqueous solution was proposed. Under optimal conditions, the quenched fluorescence intensity (F(0)-F) increased linearly with the concentration of Ag(+) ranging from 4 × 10(-7) to 32 × 10(-7)mol L(-1). The limit of detection for Ag(+) was 4.106 × 10(-8)mol L(-1). The obtained plot of F(0)/F versus [Ag(+)] was an upward curvature, concave towards the y-axis, rather than a straight line. The modified form of the Stern-Volmer equation was third order in Ag(+) concentration. According to the modified Stern-Volmer equation, it can be inferred that dynamic quenching and static quenching simultaneously occurred when Ag(+) interacted with MPA capped CdTe QDs. At the same time other factors might also influence the quenching process. Based on this study, hydrothermal synthesized MPA capped CdTe QDs with particle size 3 nm may be used as a novel fluorescence probe to quantificationally and selectively detect Ag(+).
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Two novel RING-type ubiquitin ligases, RGLG3 and RGLG4, are essential for jasmonate-mediated responses in Arabidopsis.
Plant Physiol.
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Jasmonates (JAs) regulate various stress responses and development processes in plants, and the JA pathway is tightly controlled. In this study, we report the functional characterization of two novel RING-type ubiquitin ligases, RING DOMAIN LIGASE3 (RGLG3) and RGLG4, in modulating JA signaling. Both RGLG3 and RGLG4 possessed ubiquitin ligase activities and were widely distributed in Arabidopsis (Arabidopsis thaliana) tissues. Altered expression of RGLG3 and RGLG4 affected methyl JA-inhibited root growth and JA-inductive gene expression, which could be suppressed by the coronatine insensitive1 (coi1) mutant. rglg3 rglg4 also attenuated the inhibitory effect of JA-isoleucine-mimicking coronatine on root elongation, and consistently, rglg3 rglg4 was resistant to the coronatine-secreting pathogen Pseudomonas syringae pv tomato DC3000, suggesting that RGLG3 and RGLG4 acted in response to the coronatine and promoted JA-mediated pathogen susceptibility. In addition, rglg3 rglg4 repressed wound-stunted plant growth, wound-stimulated expression of JA-responsive genes, and wound-induced JA biosynthesis, indicating their roles in JA-dependent wound response. Furthermore, both RGLG3 and RGLG4 responded to methyl JA, P. syringae pv tomato DC3000, and wounding in a COI1-dependent manner. Taken together, these results indicate that the ubiquitin ligases RGLG3 and RGLG4 are essential upstream modulators of JA signaling in response to various stimuli.
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Glycosylation potential of human prostate cancer cell lines.
Glycoconj. J.
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Altered glycosylation is a universal feature of cancer cells and altered glycans can help cancer cells escape immune surveillance, facilitate tumor invasion, and increase malignancy. The goal of this study was to identify specific glycoenzymes, which could distinguish prostate cancer cells from normal prostatic cells. We investigated enzymatic activities and gene expression levels of key glycosyl- and sulfotransferases responsible for the assembly of O- and N-glycans in several prostatic cells. These cells included immortalized RWPE-1 cells derived from normal prostatic tissues, and prostate cancer cells derived from metastasis in bone (PC-3), brain (DU145), lymph node (LNCaP), and vertebra (VCaP). We found that all cells were capable of synthesizing complex N-glycans and O-glycans with the core 1 structure, and each cell line had characteristic biosynthetic pathways to modify these structures. The in vitro measured activities corresponded well to the mRNA levels of glycosyltransferases and sulfotransferases. Lectin and antibody binding to whole cells supported these results, which form the basis for the development of tumor cell-specific targeting strategies.
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Mapping of Cu and Pb contaminations in soil using combined geochemistry, topography, and remote sensing: a case study in the Lean River floodplain, China.
Int J Environ Res Public Health
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Heavy metal pollution in soil is becoming a widely concerning environmental problem in China. The aim of this study is to integrate multiple sources of data, namely total Cu and Pb contents, digital elevation model (DEM) data, remote sensing image and interpreted land-use data, for mapping the spatial distribution of total Cu and Pb contamination in top soil along the Lean River and its branches. Combined with geographical analyses and watershed delineation, the source and transportation route of pollutants are identified. Regions at high risk of Cu or Pb pollution are suggested. Results reveal that topography is the major factor that controls the spatial distribution of Cu and Pb. Watershed delineation shows evidence that the streamflow resulting from rainfall is the major carrier of metal pollutants.
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[A controlled study on the treatment of acute progressive cerebral infarction by continuous anticoagulation with small doses of heparin].
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue
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To discuss the treatment of acute progressive cerebral infarction by continuous anticoagulation with small doses of heparin.
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Biochemical characterization of WbdN, a ?1,3-glucosyltransferase involved in O-antigen synthesis in enterohemorrhagic Escherichia coli O157.
Glycobiology
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The enterohemorrhagic O157 strain of Escherichia coli, which is one of the most well-known bacterial pathogens, has an O-antigen repeating unit structure with the sequence [-2-d-Rha4NAc?1-3-l-Fuc?1-4-d-Glc?1-3-d-GalNAc?1-]. The O-antigen gene cluster of E. coli O157 contains the genes responsible for the assembly of this repeating unit and includes wbdN. In spite of cloning many O-antigen genes, biochemical characterization has been done on very few enzymes involved in O-antigen synthesis. In this work, we expressed the wbdN gene in E. coli BL21, and the His-tagged protein was purified. WbdN activity was characterized using the donor substrate UDP-[(14)C]Glc and the synthetic acceptor substrate GalNAc?-O-PO(3)-PO(3)-(CH(2))(11)-O-Ph. The enzyme product was isolated by high pressure liquid chromatography, and mass spectrometry showed that one Glc residue was transferred to the acceptor by WbdN. Nuclear magnetic resonance analysis of the product structure indicated that Glc was ?1-3 linked to GalNAc. WbdN contains a conserved DxD motif and requires divalent metal ions for full activity. WbdN activity has an optimal pH between 7 and 8 and is highly specific for UDP-Glc as the donor substrate. GalNAc? derivatives lacking the diphosphate group were inactive as substrates, and the enzyme did not transfer Glc to GlcNAc?-O-PO(3)-PO(3)-(CH(2))(11)-O-Ph. Our results illustrate that WbdN is a specific UDP-Glc:GalNAc?-diphosphate-lipid ?1,3-Glc-transferase. The enzyme is a target for the development of inhibitors to block O157-antigen synthesis.
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Violating the isolated pentagon rule (IPR): endohedral non-IPR C98 cages of Gd2@C98.
Inorg Chem
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The geometric, electronic structure, and thermodynamic stability of large gadolinium-containing endohedral metallofullerenes, Gd(2)@C(98), have been systematically investigated by comprehensive density functional theory calculations combined with statistical mechanics treatments. The Gd(2)@C(2)(230924)-C(98) structure, which satisfies the isolated-pentagon rule (IPR), is determined to possess the lowest energy followed with some stable non-IPR isomers. In order to clarify the relative stabilities at elevated temperatures, entropy contributions are taken into account on the basis of the Gibbs energy at the B3LYP level for the first time. Interestingly, a novel non-IPR Gd(2)@C(1)(168785)-C(98) isomer which has one pair of pentagon adjacency is more thermodynamically stable than the lowest energy IPR species within a wide temperature interval related to fullerene formation. Therefore, the Gd(2)@C(1)(168785)-C(98) is predicted to be the most proper isomer obtained experimentally, which is the largest non-IPR carbon cage found so far. Our findings demonstrate that interaction between metals and carbon cages could stabilize the fused pentagons effectively, and thus, the non-IPR isomers should not be ignored in some cases of endohedral metallofullerenes. The IR features of Gd(2)@C(98) are simulated to assist its future experimental characterization.
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A clinical-pathological analysis of hepatitis B virus recurrence after liver transplantation in Chinese patients.
J. Gastroenterol. Hepatol.
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Liver transplantation (LT) for hepatitis B virus (HBV)-related disease can be complicated by HBV recurrence. The aim of this study was to evaluate the risk factors, prophylaxis treatment and histologic characteristics of HBV recurrence after LT when using long-term, low-dose hepatitis B immunoglobulin (HBIG) plus nucleoside analog (lamivudine [LAM] or entecavir [ETV]).
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