Assessment of Antiangiogenic Effect Using 99mTc-EC-endostatin

Cancer Biotherapy & Radiopharmaceuticals. Apr, 2002  |  Pubmed ID: 12030117

Tumor vascular density may provide a prognostic indicator of metastatic potential or survival. The purpose of this study was to develop 99mTc-ethylenedicysteine-endostatin (99mTc-EC-endostatin) for the evaluation of anti-angiogenesis therapy.

Temperature Dependence of Thermodynamic Properties for DNA/DNA and RNA/DNA Duplex Formation

European Journal of Biochemistry / FEBS. Jun, 2002  |  Pubmed ID: 12071944

A clear difference in the enthalpy changes derived from spectroscopic and calorimetric measurements has recently been shown. The exact interpretation of this deviation varied from study to study, but it was generally attributed to the non-two-state transition and heat capacity change. Although the temperature-dependent thermodynamics of the duplex formation was often implied, systemic and extensive studies have been lacking in universally assigning the appropriate thermodynamic parameter sets. In the present study, the 24 DNA/DNA and 41 RNA/DNA oligonucleotide duplexes, designed to avoid the formation of hairpin or slipped duplex structures and to limit the base pair length less than 12 bp, were selected to evaluate the heat capacity changes and temperature-dependent thermodynamic properties of duplex formation. Direct comparison reveals that the temperature-independent thermodynamic parameters could provide a reasonable approximation only when the temperature of interest has a small deviation from the mean melting temperature over the experimental range. The heat capacity changes depend on the base composition and sequences and are generally limited in the range of -160 to approximately -40 cal.mol-1.K-1 per base pair. In contrast to the enthalpy and entropy changes, the free energy change and melting temperature are relatively insensitive to the heat capacity change. Finally, the 16 NN-model free energy parameters and one helix initiation at physiological temperature were extracted from the temperature-dependent thermodynamic data of the 41 RNA/DNA hybrids.

Effect of Divalent Cations and Cytosine Protonation on Thermodynamic Properties of Intermolecular DNA Double and Triple Helices

Journal of Inorganic Biochemistry. Jul, 2002  |  Pubmed ID: 12121786

The contribution of divalent cations and cytosine protonation to conformation and stability of duplex and triplex formation were intensively investigated and characterized by ultraviolet (UV), circular dichroism (CD), differential scanning calorimetry (DSC), and electrophoresis mobility shift assay (EMSA). CD spectra showed that the divalent cations investigated would not significantly distort nucleotide geometry, while UV and DSC melting experiments revealed that the cation binding abilities to duplexes and triplexes were clearly dependent on the types of cations under near physiological conditions. The calorimetric enthalpies were generally underestimated relative to the corresponding van't Hoff enthalpies for Hoogsteen and Watson-Crick transitions, but free energy changes derived from the DSC measurements were in good agreement with those derived from the UV measurements. The adjacent placing of the C(+) x G.C triplets in triplexes lowered the stabilities of not only Hoogsteen base-pairing but also Watson-Crick base-pairing. The protonation contribution of the given cytosine residues might depend on the local and global structure of the protonated cytosine complex. A rigid structural targeted-strand would favor the protonation of cytosine residues. The apparent pK(a) values for parallel duplex and triplex investigated were determined to be 6.4 and 7.6, respectively, which are considerably heightened by 2.1 and 3.3 pH unit as compared to the intrinsic pK(a) value of the free cytosine residues.

Preparation of B-free Ti-MWW Through Reversible Structural Conversion

Chemical Communications (Cambridge, England). May, 2002  |  Pubmed ID: 12122647

B-free titanosilicate with the MWW topology, Ti-MWW, has been successfully prepared from its highly siliceous analogue through structural interconversion and simultaneous titanium incorporation in the presence of piperidine or hexamethyleneimine.

The Role of Oxidative Stress in Nickel and Chromate Genotoxicity

Molecular and Cellular Biochemistry. May-Jun, 2002  |  Pubmed ID: 12162442

Some general principles regarding oxidative stress and molecular responses to toxic metals are presented in this manuscript. The remainder of the manuscript, however, will focus on the role of oxidative stress in particulate nickel-induced genetic damage and mutations. The phagocytosis of particulate nickel compounds and the dissolution of the particles inside the cell and the resulting oxidative stress produced in the nucleus is a key component of the nickel carcinogenic mechanism. The crosslinking of amino acids to DNA by nickel that does not involve direct participation of nickel in a ternary complex but nickel-induced oxidative stress will be discussed as well. The selective ability of particulate nickel compounds to silence the expression of genes located near heterochromatin and the effect of vitamin E on the genotoxicity and mutations induced by particulate and soluble nickel compounds will also be discussed. Particulate nickel compounds have been shown to produce more oxidative stress than water-soluble nickel compounds. In addition to nickel, the role of oxidative stress in chromate-induced genotoxicity will also be discussed with particular attention directed to the effects of vitamin E on mutations and chromosomal aberrations inducedby chromate.

Structural and Dynamic Features of Alzheimer's Abeta Peptide in Amyloid Fibrils Studied by Site-directed Spin Labeling

The Journal of Biological Chemistry. Oct, 2002  |  Pubmed ID: 12181315

Electron paramagnetic resonance spectroscopy analysis of 19 spin-labeled derivatives of the Alzheimer's amyloid beta (Abeta) peptide was used to reveal structural features of amyloid fibril formation. In the fibril, extensive regions of the peptide show an in-register, parallel arrangement. Based on the parallel arrangement and side chain mobility analysis we find the amyloid structure to be mostly ordered and specific, but we also identify more dynamic regions (N and C termini) and likely turn or bend regions (around residues 23-26). Despite their different aggregation properties and roles in disease, the two peptides, Abeta40 and Abeta42, homogeneously co-mix in amyloid fibrils suggesting that they possess the same structural architecture.

Characterization and Thermodynamic Properties of Quadruplex/duplex Competition

FEBS Letters. Aug, 2002  |  Pubmed ID: 12208508

Structural characteristics and thermodynamic properties of dG(3)(T(2)AG(3))(3), d(C(3)TA(2))(3)C(3) and dG(3)(T(2)AG(3))(3)/d(C(3)TA(2))(3)C(3) were intensively investigated. It was indicated that metal ions greatly affected the conformation and stability of the G-quadruplex. A competition of a structure transition among the G-quadruplex, I-motif, and the duplex was confirmed to be dependent on both cation species and pH values. The structural competitive mechanism is discussed for the first time. This study shows an intriguing potential in modulating DNA structures in vivo, which is of great importance in drug design and cancer chemotherapy.

Evaluation of Antigen-based Heteropolymer for Treatment of Systemic Lupus Erythematosus in a Nonhuman Primate Model

Clinical Immunology (Orlando, Fla.). Nov, 2002  |  Pubmed ID: 12482388

Autoantibodies that react with double-stranded DNA (dsDNA) are a hallmark for diagnosis of systemic lupus erythematosus (SLE) and are also considered the pathogenic subset that is most associated with lupus nephritis. As an agent to remove the pathogenic dsDNA antibodies from the circulation of SLE patients, we are developing an antigen-based heteropolymer (AHP). The AHP consists of a monoclonal antibody to the complement receptor (CR1) cross-linked to salmon testis dsDNA to effect clearance of anti-DNA antibodies by binding them to erythrocyte CR1. Utilizing a cynomolgus monkey model for SLE in which we infused plasma from SLE patients containing a high titer of high-avidity anti-dsDNA antibody, we have evaluated the safety and efficacy of AHP infusion. The results demonstrate that AHP rapidly (within 2 min of infusion) binds to monkey erythrocytes without causing any toxicological effects. We also demonstrate that human Ig (G+M) antibodies are rapidly bound to the AHP-erythrocyte complex. These events are mirrored in their kinetics by a substantial drop in the level of high-avidity dsDNA antibody in the plasma.

Observation of Functional Group Mediated Assembling of Dendritic Molecules by STM

Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry. Jul, 2002  |  Pubmed ID: 12503167

[Selection of the Imaging Modalities for Diagnosis of Renal Trauma: Experience with 74 Cases]

Di 1 Jun Yi Da Xue Xue Bao = Academic Journal of the First Medical College of PLA. Aug, 2003  |  Pubmed ID: 12919927

To explore the diagnostic approaches and values of the imaging modalities for traumatic renal injuries.

A Titanosilicate That is Structurally Analogous to an MWW-type Lamellar Precursor

Angewandte Chemie (International Ed. in English). Jan, 2004  |  Pubmed ID: 14695619

Efficiency and Fidelity in a Click-chemistry Route to Triazole Dendrimers by the Copper(i)-catalyzed Ligation of Azides and Alkynes

Angewandte Chemie (International Ed. in English). Jul, 2004  |  Pubmed ID: 15274216

[A New Chromatographic Method for Separation and Purification of Nerve Growth Factor from Venom of Chinese Cobra]

Se Pu = Chinese Journal of Chromatography / Zhongguo Hua Xue Hui. Jan, 2004  |  Pubmed ID: 15712933

In order to find a simple, fast and highly efficient method for the separation and purification of nerve growth factor (NGF) from venom of Chinese Cobra, the combination process of several different kinds of chromatographic media was studied. According to the properties of NGF and the character of different chromatographic media, a novel two-step chromatographic purification method, consisting of chromatography of crude venom on DEAE-Sepharose F. F. anion-exchange medium followed by a size exclusion on a Sephadex G-50 column, is presented. The DEAE-Sepharose F. F. chromatographic column was 20 cm x 3.5 cm i.d. and first eluted with 50 mmol/L Tris-HCl (pH 8.5) for 50 min, and separately followed by an elution with a linear gradient of 0 - 200 mmol/L NaCl containing 50 mmol/L Tris-HCl (pH 8.5) for 190 min and with 200 mmol/L NaCl containing 50 mmol/L Tris-HCl (pH 8.5) for 60 min. The flow rate of mobile phase was 6.1 mL/min. The Sephadex G-50 column was 150 cm x 3.5 cm i.d. and eluted with 50 mmol/L phosphate-buffered saline (PBS) (pH 7.5) for 1 250 min. The flow rate of elution solution was 2.4 mL/min. Through this two-step chromatographic purification process, the obtained NGF was proved to be homogeneous on sodium-dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and its relative molecular mass was estimated to be approximately 29 000, which was consistent with that reported in literature. On a Shim-Pack VP-ODS reversed-phase high performance chromatographic column (4.6 mm i.d. x 150 mm), its purity was about 98.3%. The total protein recovery of this purification method was 0.51% and the obtained NGF had the activity of eliciting neurite outgrowth from chick embryonic dorsal root ganglia. This two-step chromatographic process is simple and highly efficient. It can be used to isolate and purify NGF from venom of Chinese Cobra in large-scale.

[Nephron-sparing Surgery for Small Renal Cell Carcinoma: Clinical Analysis of 21 Cases]

Di 1 Jun Yi Da Xue Xue Bao = Academic Journal of the First Medical College of PLA. Mar, 2005  |  Pubmed ID: 15772014

To evaluate the clinical effects of nephron-sparing surgery in patients with early-stage small renal cell carcinoma.

A DeImmunized Chimeric Anti-C3b/iC3b Monoclonal Antibody Enhances Rituximab-mediated Killing in NHL and CLL Cells Via Complement Activation

Cancer Immunology, Immunotherapy : CII. Dec, 2005  |  Pubmed ID: 15846490

Complement-dependent cytotoxicity (CDC) is a key mechanism of Rituximab (RTX) action in killing non-Hodgkin's lymphoma (NHL) cells both in vitro and probably in vivo. A DeImmunized, mouse/human chimeric monoclonal antibody (Mab), H17, specific for cell-associated complement C3 cleavage products, C3b and iC3b, was generated to enhance RTX-mediated killing of target cells by CDC. When NHL cell lines were treated with RTX and H17 in the presence of complement for 1 h, there was 40-70% more cell death than that observed with RTX alone. The enhancing effect of H17 was also seen over longer treatment periods. H17 was tested ex vivo against primary cells from NHL and chronic lymphocytic leukemia (CLL) patients. In RTX-resistant NHL samples, H17 enhanced RTX-mediated killing; in the remaining samples RTX + complement alone promoted more than 80% killing, and no significant enhancement was observed. The H17 antibody also increased RTX-mediated killing in four out of nine CLL samples. H17 may have therapeutic applications in NHL and CLL treatment as an adjunctive therapy to RTX. It might also enhance the activity of other therapeutic antibodies that work through CDC.

DNA-based Biosensor for Monitoring PH in Vitro and in Living Cells

Biochemistry. May, 2005  |  Pubmed ID: 15882051

DNA is a promising material for the construction of a biosensor or bioindicator because its structure is sensitive to the binding of cofactors. In the current studies, we found that a combination of two DNA oligonucleotides, 5'-TCTTTCTCTTCT-3' and 5'-AGAAAGAGAAGA-3', exhibit a novel structural transition from a Watson-Crick antiparallel duplex to a parallel Hoogsteen duplex as the pH changes from pH 7.0 to 5.0. By labeling this DNA for fluorescence resonance energy transfer, we were able to develop a sensitive pH indicator that can detect changes between pH 7.0 and 5.0. Moreover, using DNA-based hairpin parallel-stranded duplex in conjunction with fluorescence microscopy, we were able to observe the pH changes in living cells during apoptosis as an easily detected change in color. These results indicate that the DNA-based pH indicator should be useful for detecting pH changes between pH 7.0 and 5.0 in living cells.

[Expression of Human Telomerase Reverse Transcriptase in Cervix Cancer and Its Significance]

Zhonghua Fu Chan Ke Za Zhi. Jun, 2005  |  Pubmed ID: 16008894

To investigate the expression of human telomerase reverse transcriptase (hTERT) mRNA and protein in cervix cancer, cervical intraepithelial neoplasia (CIN) and normal cervix.

Role of HTERT in Apoptosis of Cervical Cancer Induced by Histone Deacetylase Inhibitor

Biochemical and Biophysical Research Communications. Sep, 2005  |  Pubmed ID: 16051188

Human telomerase reverse transcriptase (hTERT) is the catalytic subunit of telomerase holoenzyme as well as the rate-limiting component of the telomerase enzyme complex. However, the role of the hTERT in apoptosis induced by histone deacetylase inhibitor has only been marginally addressed. For the first time, our study demonstrated that trichostatin A (TSA) briefly activated the proliferation of cervical cancer cell lines, HeLa and SiHa, within 12 h, but then inhibited cell growth after that time point. In response to TSA, hTERT expression, telomerase activity, and telomere length also underwent similar changes during the same time frame. Furthermore, the data in our study showed that cells transfected with dominant negative hTERT were more likely to undergo apoptosis induced by TSA than cells transfected with wild-type hTERT. The cyclin/cdk inhibitor p21waf1 was down-regulated by hTERT without changing the expression of p53. Results from this study suggest that the hTERT might be a primary target of TSA and the anti-apoptosis effect of hTERT might be carried out through a p21waf1-dependent and p53-independent pathway.

Analysis of Human Multidrug Resistance Protein 1 (ABCC1) by Matrix-assisted Laser Desorption Ionization/time of Flight Mass Spectrometry: Toward Identification of Leukotriene C4 Binding Sites

Molecular Pharmacology. Nov, 2005  |  Pubmed ID: 16105987

Multidrug resistance in tumor cells may be caused by reduced drug accumulation resulting from expression of one or more proteins belonging to the ATP-binding cassette (ABC) transporter superfamily. In addition to their drug efflux properties, certain ABC proteins such as multidrug resistance protein 1 (MRP1) (ABCC1) mediate the ATP-dependent transport of a broad array of organic anions. The intrinsically photoreactive glutathione-conjugated cysteinyl leukotriene C4 (LTC4) is a high-affinity physiological substrate of MRP1 and is widely regarded as a model compound for evaluating the substrate binding and transport properties of wild-type and mutant forms of the transporter. In the present study, we have optimized high-level expression of recombinant human MRP1 in Pichia pastoris and developed a two-step purification scheme that results in purification of the transporter to >90% homogeneity. Peptide mapping by matrix-assisted laser desorption ionization/time of flight mass spectrometry of the peptides generated by in-gel protease digestions of purified underglycosylated MRP1 identified 96.7% of the MRP1 sequence with >98% coverage of its 17 transmembrane helices. Subsequent comparisons with mass spectra of MRP1 photolabeled with LTC4 identified six candidate LTC4-modified peptide fragments that are consistent with the conclusion that the intracellular juxtamembrane positions of transmembrane helices 6, 7, 10, 17, and a COOH-proximal portion of the cytoplasmic loop that links the first and second membrane spanning domains are part of the LTC4 binding site of the transporter. Our studies confirm the usefulness of mass spectrometry for analysis of mammalian polytopic membrane proteins and for identification of substrate binding sites of human MRP1.

One-pot Copper(I)-catalyzed Synthesis of 3,5-disubstituted Isoxazoles

The Journal of Organic Chemistry. Sep, 2005  |  Pubmed ID: 16149810

[reaction: see text] 3,5-Disubstituted isoxazoles are obtained in good yields by a convenient one-pot, three-step procedure utilizing a regioselective copper(I)-catalyzed cycloaddition reaction between in situ generated nitrile oxides and terminal acetylenes. Most functional groups do not interfere with the reaction, which can be performed in aqueous solvents without protection from oxygen. Since all reagents are used in stoichiometric amounts, formation of byproducts is minimized.

Structure Elucidation of the Highly Active Titanosilicate Catalyst Ti-YNU-1

Angewandte Chemie (International Ed. in English). Oct, 2005  |  Pubmed ID: 16173004

Automation of Liquid-liquid Extraction-spectrophotometry Using Prolonged Pseudo-liquid Drops and Handheld CCD for Speciation of Cr(VI) and Cr(III) in Water Samples

Analytical Sciences : the International Journal of the Japan Society for Analytical Chemistry. Oct, 2005  |  Pubmed ID: 16270577

A simple spectrophotometric system, based on a prolonged pseudo-liquid drop device as an optical cell and a handheld charge coupled device (CCD) as a detector, was constructed for automatic liquid-liquid extraction and spectrophotometric speciation of trace Cr(VI) and Cr(III) in water samples. A tungsten halogen lamp was used as the light source, and a laboratory-constructed T-tube with two open ends was used to form the prolonged pseudo-liquid drop inside the tube. In the medium of perchloric acid solution, Cr(VI) reacted with 1,5-diphenylcarbazide (DPC); the formed complex was automatically extracted into n-pentanol, with a preconcentration ratio of about 5. The organic phase with extracted chromium complex was then pumped through the optical cell for absorbance measurement at 548 nm. Under optimal conditions, the calibration curve was linear in the range of 7.5 - 350 microg L(-1), with a correlation coefficient of 0.9993. The limit of detection (3sigma) was 7.5 microg L(-1). That Cr(III) species cannot react with DPC, but can be oxidized to Cr(VI) prior to determination, is the basis of the speciation analysis. The proposed speciation analysis was sensitive, yet simple, labor-effective, and cost-effective. It has been preliminarily applied for the speciation of Cr(VI) and Cr(III) in spiked river and tap water samples. It can also be used for other automatic liquid-liquid extraction-spectrophotometric determinations.

Multivalent, Bifunctional Dendrimers Prepared by Click Chemistry

Chemical Communications (Cambridge, England). Dec, 2005  |  Pubmed ID: 16307142

Unsymmetrical dendrimers, containing both mannose binding units and coumarin fluorescent units, have been prepared using click chemistry and shown to be highly efficient, dual-purpose recognition/detection agents for the inhibition of hemagglutination.

Regulation of NK Cell Activation by Stimulatory and Inhibitory Receptors in Tumor Escape from Innate Immunity

Frontiers in Bioscience : a Journal and Virtual Library. 2005  |  Pubmed ID: 15970568

Recent years have witnessed our major progresses in understanding the membrane-bound receptors on NK cells. Although functional studies of ligands for these NK cell receptors provide good opportunities to study roles of NK cells in anti-tumor and anti-virus immunosurveillance, little was known about how these ligands expression were modulated under physiological and pathological conditions. Several recognition models have been proposed to explain such an issue, which include "missing-self", "induced-self" and "modified-self" recognition model. Here stimulatory immunoreceptor mediated NK cell activation will be reviewed, and possible recognition mechanism by which NK cells operate during interaction with target cells will be discussed in details. Tumor escape from NK cell-mediated immunosurveillance will also be further addressed.

DNA and Protein Microarray Printing on Silicon Nitride Waveguide Surfaces

Biosensors & Bioelectronics. Jan, 2006  |  Pubmed ID: 16002276

Sputtered silicon nitride optical waveguide surfaces were silanized and modified with a hetero-bifunctional crosslinker to facilitate thiol-reactive immobilization of contact-printed DNA probe oligonucleotides, streptavidin and murine anti-human interleukin-1 beta capture agents in microarray formats. X-ray photoelectron spectroscopy (XPS) was used to characterize each reaction sequence on the native silicon oxynitride surface. Thiol-terminated DNA probe oligonucleotides exhibited substantially higher surface printing immobilization and target hybridization efficiencies than non-thiolated DNA probe oligonucleotides: strong fluorescence signals from target DNA hybridization supported successful DNA oligonucleotide probe microarray fabrication and specific capture bioactivity. Analogously printed arrays of thiolated streptavidin and non-thiolated streptavidin did not exhibit noticeable differences in either surface immobilization or analyte capture assay signals. Non-thiolated anti-human interleukin-1 beta printed on modified silicon nitride surfaces reactive to thiol chemistry exhibited comparable performance for capturing human interleukin-1 beta analyte to commercial amine-reactive microarraying polymer surfaces in sandwich immunoassays, indicating substantial non-specific antibody-surface capture responsible for analyte capture signal.

Drug/device Combinations for Local Drug Therapies and Infection Prophylaxis

Biomaterials. Apr, 2006  |  Pubmed ID: 16337266

Combination devices-those comprising drug releasing components together with functional prosthetic implants-represent a versatile, emerging clinical technology promising to provide functional improvements to implant devices in several classes. Landmark antimicrobial catheters and the drug-eluting stent have heralded the entrance, and significantly, routes to FDA approval, for these devices into clinical practice. This review describes recent strategies creating implantable combination devices. Most prominent are new combination devices representing current orthopedic and cardiovascular implants with new added capabilities from on-board or directly associated drug delivery systems are now under development. Wound coverings and implantable sensors will also benefit from this combination enhancement. Infection mitigation, a common problem with implantable devices, is a current primary focus. On-going progress in cell-based therapeutics, progenitor cell exploitation, growth factor delivery and advanced formulation strategies will provide a more general and versatile basis for advanced combination device strategies. These seek to improve tissue-device integration and functional tissue regeneration. Future combination devices might best be completely re-designed de novo to deliver multiple bioactive agents over several spatial and temporal scales to enhance prosthetic device function, instead of the current 'add-on' approach to existing implant device designs never originally intending to function in tandem with drug delivery systems.

Osmolyte-induced Protein Folding Free Energy Changes

Proteins. May, 2006  |  Pubmed ID: 16453342

Upon addition of protecting osmolyte to an aqueous solution of an intrinsically unstructured protein, spectral observables are often seen to change in a sigmoid fashion as a function of increasing osmolyte concentration. Commonly, such data are analyzed using the linear extrapolation model (LEM), a method that defines a scale from 0%-100% folded species at each osmolyte concentration by means of extending pre- and post-folding baselines into the transition region. Defining the 0%-100% folding scale correctly for each osmolyte is an important part of the analysis, leading to evaluation of the fraction of folded protein existing in the absence of osmolytes. In this study, we used reduced and carboxyamidated RNase T1 (RCAM-T1) as an intrinsically unstructured protein, and determined the thermodynamic stability of RCAM-T1 induced by naturally occurring osmolytes. Because the folded fraction of the protein population determined by experiments of thermal and urea-induced denaturation is nonzero in the absence of osmolytes at 15 degrees C, the commonly used LEM can lead to false values of DeltaG[stackD-->N0] for protein folding due to the arbitrary assumption that the protein is 100% unfolded in the presence of buffer alone. To correct this problem, titration of the protein solution with urea and extrapolating back to zero urea concentration gives the spectral value for 100% denatured protein. With fluorescence as the observable we redefine F/F0 to F/F0extrap = 1.0 and require that the denatured-state baseline have this value as its intercept. By so doing, the 0%-100% scale-corrected DeltaG[D-->N0] values of RCAM-T1 folding in the presence of various osmolytes are then found to be identical, with small error, demonstrating that DeltaG[D-->N0] is independent of the osmolytes used. Such a finding is an important step in validating this quantity derived from the LEM as having the properties expected of an authentic thermodynamic parameter. The rank order of osmolyte efficacies in stabilizing RCAM-T1 is sarcosine > sucrose > sorbitol > proline > betaine > glycerol.

[Relationship Between Programmed Cell Death 5 Protein Expression and Prognosis of Renal Clear Cell Carcinoma]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Sep, 2006  |  Pubmed ID: 16982445

To study the role of programmed cell death 5 (PDCD5) protein in the oncogenesis and development of renal clear cell carcinoma and its association with the prognosis of the malignancy.

Comparison of Hydroxylated Print Additives on Antibody Microarray Performance

Journal of Proteome Research. Nov, 2006  |  Pubmed ID: 17081047

Various hydroxylated additives were added to antibody print buffers at different concentrations to stabilize printed antibodies during normal array spot desiccation on commercial polymer-coated microarray slides. Polyvinyl alcohol addition to print buffers produced the most regular spot morphologies, homogeneous intra-spot antibody distribution, uniform fluorescence intensity, and improved analyte capture activity, maintained up to 1 month at 4 degrees C for capturing model analytes, anti-human IL-1beta, IL-4, and TNFalpha, on these microarraying slides.

Selective and Efficient Inhibition of the Alternative Pathway of Complement by a MAb That Recognizes C3b/iC3b

Molecular Immunology. Mar, 2006  |  Pubmed ID: 15961157

The alternative pathway (AP) of the complement system plays an important role in tissue damage and inflammation associated with certain autoimmune diseases and with ischemia-reperfusion injury. Selective inhibition of the AP could prevent such pathologies while allowing the classical and lectin pathways of complement activation to continue to provide protection. Here we present data describing selective inhibition of the AP of complement by anti-C3b/iC3b monoclonal antibody (mAb) 3E7, and by a chimeric, "deimmunized" form of this mAb, H17, which contains the human IgG1 Fc region and was further modified by substitution of amino acids in order to remove T cell epitopes. Both mAbs block AP-mediated deposition of C3b onto zymosan or Sepharose 4B, and they also inhibit AP-promoted lysis of rabbit erythrocytes. MAbs 3E7 and H17 also successfully compete with both factors B and H for binding to C3b-opsonized substrates, and the ability of both mAbs to inhibit the AP is blocked by pre-incubation with two different sources of C3(H2O). Kinetic measurements demonstrate that mAb 3E7 effectively stops progression of C3b deposition after AP activation is initiated. Our results therefore suggest that these mAbs block activation of the AP by binding to both C3(H2O) and to C3b, and thus prevent binding and activation of factor B. Based on these and other observations, mAb H17 may find future use in therapeutic applications focused on selective inhibition of the AP.

Deletion of the Intracellular Domain of Coxsackie and Adenovirus Receptor (CAR) Enhances the Expression of Itself and Boosts the Efficiency of Current Adenovirus-mediated Gene Therapy in Ovarian Cancer Cell Lines in Vitro

Cancer Letters. Apr, 2007  |  Pubmed ID: 17166654

The failure of adenovirus-mediated gene therapy often derives from the absence of coxsackie and adenovirus receptor (CAR) expression in target cells. We hypothesize that the slight up-regulation of CAR expression might boost the effect of adenovirus-mediated gene therapy in ovarian cancer. To test this hypothesis, we transfected full-length and intracellular-domain-deleted (tailless) CAR plasmids into CAR-deficient ovarian cancer cell line SKOV3. We observed significant elevations of the in vitro killing effect of Adv-TK and oncolytic adenovirus-mediated cytopathic effect (CPE) in transfected sub-clones, and tailless-transfected SKOV3 showed higher CAR expressions than full-length CAR-transfected cells. We conclude that the extracellular domain of CAR is essential for adenovirus-based gene therapy and, furthermore, that its intracellular domain might play an important role in the regulation of its own expression.

Inhibition and Structure of Trichomonas Vaginalis Purine Nucleoside Phosphorylase with Picomolar Transition State Analogues

Biochemistry. Jan, 2007  |  Pubmed ID: 17223688

Trichomonas vaginalis is a parasitic protozoan purine auxotroph possessing a unique purine salvage pathway consisting of a bacterial type purine nucleoside phosphorylase (PNP) and a purine nucleoside kinase. Thus, T. vaginalis PNP (TvPNP) functions in the reverse direction relative to the PNPs in other organisms. Immucillin-A (ImmA) and DADMe-Immucillin-A (DADMe-ImmA) are transition state mimics of adenosine with geometric and electrostatic features that resemble early and late transition states of adenosine at the transition state stabilized by TvPNP. ImmA demonstrates slow-onset tight-binding inhibition with TvPNP, to give an equilibrium dissociation constant of 87 pM, an inhibitor release half-time of 17.2 min, and a Km/Kd ratio of 70,100. DADMe-ImmA resembles a late ribooxacarbenium ion transition state for TvPNP to give a dissociation constant of 30 pM, an inhibitor release half-time of 64 min, and a Km/Kd ratio of 203,300. The tight binding of DADMe-ImmA supports a late SN1 transition state. Despite their tight binding to TvPNP, ImmA and DADMe-ImmA are weak inhibitors of human and P. falciparum PNPs. The crystal structures of the TvPNP x ImmA x PO4 and TvPNP x DADMe-ImmA x PO4 ternary complexes differ from previous structures with substrate analogues. The tight binding with DADMe-ImmA is in part due to a 2.7 A ionic interaction between a PO4 oxygen and the N1' cation of the hydroxypyrrolidine and is weaker in the TvPNP x ImmA x PO4 structure at 3.5 A. However, the TvPNP x ImmA x PO4 structure includes hydrogen bonds between the 2'-hydroxyl and the protein that are not present in TvPNP x DADMe-ImmA x PO4. These structures explain why DADMe-ImmA binds tighter than ImmA. Immucillin-H is a 12 nM inhibitor of TvPNP but a 56 pM inhibitor of human PNP. And this difference is explained by isotope-edited difference infrared spectroscopy with [6-18O]ImmH to establish that O6 is the keto tautomer in TvPNP x ImmH x PO4, causing an unfavorable leaving-group interaction.

Array Feature Size Influences Nucleic Acid Surface Capture in DNA Microarrays

Proceedings of the National Academy of Sciences of the United States of America. May, 2007  |  Pubmed ID: 17485675

Analyte affinity capture by surface-immobilized diagnostic agents is a routinely used assay format for profiling numerous medically and technologically important target analytes. These assays suffer from numerous performance limitations, including sensitivity and rapidity. Assay miniaturization is advocated to improve surface-capture performance, specifically exploiting the inverse relationship between analyte flux and capture feature size under mass transfer-limiting capture conditions that characterize many such assay formats. Reduced capture feature sizes, e.g., microarrays, are proposed to overcome mass transfer limitations, yet this is difficult to achieve across several size scales. This study validates certain advantages advocated for capture spot miniaturization using a rationale to understand surface capture miniaturization strategies. Experimentally derived immobilized ligand and target capture densities as a function of microspot size for DNA oligomers immobilized on model gold substrates are compared directly with theoretical analysis, validating the hypothesis that miniaturization yields many practical assay advantages. Specifically, results show that transitions from assay mass transfer limiting to kinetically limiting conditions as feature size decreases identify an optimal microspot size range for a specific bioassay system. Analytical advantages realized from such assay miniaturization are more uniform target-spot coverage and substantially increased rate of capture (hybridization), increasing assay signal and rapidity.

[Role of Human Telomerase Reverse Transcriptase in Apoptosis of Human Umbilical Vein Endothelial Cells Induced by Trichostatin A]

Zhonghua Zhong Liu Za Zhi [Chinese Journal of Oncology]. May, 2007  |  Pubmed ID: 17892126

The aim of this study was designed to investigate the effect of TSA on human umbilical vein endothelial cells and to reveal its possible mechanisms and relationship between apoptosis and activity of telomerase reverse transcriptase.

[Expression and Significance of Smad2/3 and HPV16 E7 in Cervical Intraepithelial Neoplasia and Cervical Carcinoma]

Ai Zheng = Aizheng = Chinese Journal of Cancer. Sep, 2007  |  Pubmed ID: 17927854

Smad proteins are downstream signal proteins of the transforming growth factor-beta (TGF-beta) superfamily, which are intimately related to the genesis of many human carcinomas. Human papillomavirus (HPV) is an important carcinogenic agent of cervical cancer. However, their relationship in the genesis of cervical cancer is unclear. This study was to detect the expression of Smad2/3 and HPV16 E7 protein in different cervical lesions, and to explore their possible roles in tumor genesis and progression.

A Systematic Method for Mapping Multiple Loci: an Application to Construct a Genetic Network for Rheumatoid Arthritis

Gene. Jan, 2008  |  Pubmed ID: 18082339

The advent of high-throughput single nucleotide polymorphisms (SNPs) omics technologies has brought tremendous genetic data. Systematic evaluation of the genome-wide SNPs is expected to provide breakthroughs in the understanding of complex diseases. In this study, we developed a new systematic method for mapping multiple loci and applied the proposed method to construct a genetic network for rheumatoid arthritis (RA) via analysis of 746 multiplex families genotyped with more than five thousands of genome-wide SNPs. We successfully identified 41 significant SNPs relevant to RA, 25 associated genes and a number of important SNP-SNP interactions (SNP patterns). Many findings (loci, genes and interactions) have experimental support from previous studies while novel findings may define unknown genetic pathways for this complex disease. Finally, we constructed a genetic network by integrating the results from this analysis with the rapidly accumulated knowledge in biomedical domains, which gave us a more detailed insight onto the RA etiology. The results suggest that the proposed systematic method is powerful when applied to genome-wide association studies. Integrating the analysis of high-throughput SNP data with knowledge-based SNP functional annotation offers a promising way to reversely engineer the underlying genetic networks for complex human diseases.

[Expression of Human Telomerase Reverse Transcriptase in Renal Cell Carcinoma and Its Clinical Significance]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Feb, 2008  |  Pubmed ID: 18250061

To investigate the expression of human telomerase reverse transcriptase (hTERT) in renal cell carcinoma (RCC) and its clinical significance.

Isolated and Linear Arrays of Surfactant-encapsulated Polyoxometalate Clusters on Graphite

Langmuir : the ACS Journal of Surfaces and Colloids. Mar, 2008  |  Pubmed ID: 18275233

We report on the self-assembly of several surfactant-encapsulated clusters (SECs) on the basal plane of graphite consisting of the doughnut-shaped tungstophosphate anion [Na(H2O)P5W30O110] covered by a hydrophobic shell of surfactants. Well-ordered rodlike structures are observed using scanning force microscopy. No such ordering is observed if the surfactant methyltrioctadecylammonium is used for encapsulation, suggesting that the density of alkyl chains around the polyoxometalate cluster is an important factor in determining the order of SEC assemblies on graphite. Coadsorption of tetratetracontane (n-C44H90) and (DODA)14[Na(H2O)P5W30O110] results in single, isolated SECs on a buffer layer of tetratetracontane, as determined by scanning tunneling microscopy.

Evaluation of Tungsten Coil Electrothermal Vaporization-Ar/H2 Flame Atomic Fluorescence Spectrometry for Determination of Eight Traditional Hydride-forming Elements and Cadmium Without Chemical Vapor Generation

Talanta. Jan, 2008  |  Pubmed ID: 18371668

A tungsten coil electrothermal vaporizer (W-coil ETV) was coupled to an Ar/H(2) flame atomic fluorescence spectrometer for the determination of eight traditional hydride-forming elements (i.e., As, Bi, Ge, Pb, Sb, Se, Sn, and Te) as well as cadmium without chemical vapor generation. A small sample volume, typically 20muL, was manually pipetted onto the W-coil and followed by a fixed electric heating program. During the vaporization step, analyte was vaporized off the coil surface and swept into the quartz tube atomizer of AFS for further atomization and excitation of atomic fluorescence by a flow of Ar/H(2) gas, which was ignited to produce the Ar/H(2) flame. The tungsten coil electrothermal vaporizer and Ar/H(2) flame formed a tandem atomizer to produce reliable atomic fluorescence signals. Under the optimal instrumental conditions, limits of detection (LODs) were found to be better than those by flame atomic absorption spectrometry (FAAS) or inductively coupled plasma optical emission spectrometry (ICP-OES) for all the nine elements investigated. The absolute LODs are better or equivalent to those by hydride generation atomic fluorescence spectrometry (HG-AFS). Possible scattering interferences were studied and preliminary application of the proposed method was also reported.

The Performance and Phase Separated Characteristics of an Anaerobic Baffled Reactor Treating Soybean Protein Processing Wastewater

Bioresource Technology. Nov, 2008  |  Pubmed ID: 18450441

A laboratory-scale anaerobic baffled reactor (ABR) with four compartments using soybean protein processing wastewater as organic loading rates (OLRs) was investigated for the performance and phase separated characteristics. It was found that the chemical oxygen demand (COD) removal efficiencies were 92-97% at 1.2-6.0kgCOD/m3d feeding. The dominated species, propionate and butyrate, were found in the 1st compartment. Acetate was dominated in the 2nd compartment and then decreased in the 3rd and 4th. Meanwhile, 93% volatile fatty acids (VFAs) were removed in the 3rd and 4th compartments. In the 1st compartment, biogas revealed carbon dioxide (CO2) and hydrogen (H2). The highest H2 yield was found in the 2nd compartment, thereafter decreased from the 2nd to 4th which corresponded to the increased of the methane (CH4) yield. It indicated that the proper anaerobic consortium in each separate compartment was developed along with substrate availability and specific environmental conditions.

[Detection of Skp2 and P27kip1 Expression in Human Renal Cell Carcinoma Using Tissue Chip Technique]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Apr, 2008  |  Pubmed ID: 18495610

To detect the expression of skp2 and p27kip1 in human renal cell carcinoma (RCC) using tissue chip technique, and evaluate the relationship between the proteins and the biological behavior of RCC.

Biocompatible Carbon Nanotubes Generated by Functionalization with Glycodendrimers

Angewandte Chemie (International Ed. in English). 2008  |  Pubmed ID: 18509843

Methodology for Synthesizing Crystalline Metallosilicates with Expanded Pore Windows Through Molecular Alkoxysilylation of Zeolitic Lamellar Precursors

Journal of the American Chemical Society. Jul, 2008  |  Pubmed ID: 18528990

Postalkoxysilylation with diethoxydimethylsilane has been carried out on the zeolitic lamellar precursors of various topologies such as MWW, FER, CDO and MCM-47 aiming to construct new crystalline structures with expanded pore apertures between the layers. The silylation process and the crystalline and pore structures of the resulting materials have been investigated with the techniques of XRD, IR, (13)C and (29)Si MAS NMR, ICP, SEM, HRTEM, elemental analyses, and N 2 adsorption. In contrast to forming known three-dimensional zeolite structures after direct calcination of the lamellar precursors, the silylation led to new crystalline structures with opener pores, as evidenced by the shift of layer-related diffractions to the lower-angle region in XRD patterns and the enlarged interlayer pores found by HRTEM images. After optimizing the treatment conditions, particularly the amount of silane agent, a maximum and homogeneous silylation was realized, which guaranteed the phase purity in interlayer expanded zeolites. The expanded structures were well preserved after calcination at 823 K or reflux in water for 1 to 2 weeks, indicating a high thermal stability and also a hydrothermal stability. The interlayer expanded zeolites prepared from the metallosilicate precursors of MWW topology exhibited higher catalytic activities in the redox and solid acid-catalyzed reactions of bulky molecules than that of their counterparts with conventional MWW topology.

Diagnostic Devices As Biomaterials: a Review of Nucleic Acid and Protein Microarray Surface Performance Issues

Journal of Biomaterials Science. Polymer Edition. 2008  |  Pubmed ID: 18534094

This review of current DNA and protein microarray diagnostic and bio-analytical technologies focuses on the different surface chemistries used in these miniaturized surface-capture formats. Description of current strategies in bio-immobilization and coupling to create multiplexed affinity bioassays in micrometer-sized printed spots, problems with current formats and review of some detection methods are included. Recommendations for improving long-standing challenges in DNA- and protein-based arrays are forwarded. The biomaterials community can contribute relevant expertise to these formidable bio-interfacial problems that represent significant barriers to clinical implementation of microarray assays.

Synthesis, Crystallization Mechanism, and Catalytic Properties of Titanium-rich TS-1 Free of Extraframework Titanium Species

Journal of the American Chemical Society. Aug, 2008  |  Pubmed ID: 18613685

A new route to the synthesis of TS-1 has been developed using (NH4)2CO3 as a crystallization-mediating agent. In this way, the framework Ti content can be significantly increased without forming extraframework Ti species. The prepared catalyst had a Si/Ti ratio as low as 34 in contrast to the ratio of 58 achieved with the methods A and B established by the Enichem group (Clerici, M. G.; Bellussi, G.; Romano, U. J. Catal. 1991, 129, 159) and Thangaraj and Sivasanker (Thangaraj, A.; Sivasanker, S. J. Chem. Soc., Chem. Commun. 1992, 123), respectively. The material contained less defect sites than the samples synthesized by the other two methods. As a result, it showed much higher activity for the oxidation of various organic substrates, such as linear alkanes/alkenes and alcohols, styrene, and benzene. The crystallization mechanism of TS-1 in the presence of (NH4)2CO3 was studied by following the whole crystallization process with X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), thermogravimetry/differential thermal analysis (TG/DTA), inductively coupled plasma atomic emission spectrometry (ICP), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), diffuse reflectance UV-vis spectroscopy, and (29)Si MAS (magic-angle spinning) NMR spectroscopy techniques. It was shown that the presence of (NH4)2CO3 not only drastically lowered down pH, slowing down the crystallization process and making the incorporation of Ti into the framework match well with nucleation and crystal growth, but also modified the crystallization mechanism. It seems that the solid-phase transformation mechanism predominated in the crystallization process initiated by dissociation, reorganization, and recoalescence of the solidified gel although a small amount of nongelatinated Ti shifted to the solid during the crystal growth period. In contrast, a typical homogeneous nucleation mechanism occurred in the method A system. Thus, although in the method A system most of Ti cations was inserted into the lattice after the crystallization was nearly completed, the inclusion of Ti started at the earlier nucleation period in the presence of (NH4)2CO3. This is favorable for the incorporation of Ti into the framework, resulting in a more homogeneous distribution of Ti in the framework. Oxidation of 1-hexene and 2-hexanol over the samples collected during the whole crystallization process indicated that condensation of Ti-OH and Si-OH proceeded even after the crystallization was completed. This resulted in an increase in hydrophobicity and an overall improvement in microscopic character of Ti species and consequently a great increase in the catalytic activity with further progress of crystallization.

Design, Synthesis, and Fungicidal Activity of Macrolactones and Macrolactams with a Sulfonamide Side Chain

Journal of Agricultural and Food Chemistry. Aug, 2008  |  Pubmed ID: 18616265

Four series of novel macrolactones and macrolactams12-alkylsulfonamido-1,15-pentadecanlactones ( 5), 12-alkylsulfonamido-15-methyl-1,15-pentadecanlactones ( 6), 12-alkylsulfonamido-1,15-pentadecanlactams ( 7), and N-(alkylsulfonamidoethyl)-1,12-dodecanlactams ( 8)were designed and synthesized from readily available 2-nitrocyclododecanone or cyclododecanone. Their structures were confirmed by (1)H NMR, IR, and elemental analysis. The bioassay showed that these compounds displayed fair to excellent fungicidal activity against Rhizoctonia solani Kuhn and have a gradual increase of fungicidal activity in the order of 6, 7, 8, and 5. Among them, compounds 5a, 5b, and 5c displayed excellent fungicidal activity against R. solani comparable with the commercial fungicide carbendazim. Above results illustrated that the rule on the relationship between the activity and hydrogen-bonding, namely the macrocyclic compounds with a hydrogen-bonding acceptor and a hydrogen-bonding donor on the ring and having a three methylenes distance between two polarizable groups have the best fungicidal activity against R. solani, has a general suitability to the macrocyclic compounds, and pesticide molecules may combine with a target enzyme by hydrogen-bonding. The facts, which compound 6 has a much lower fungicidal activity against R. solani than compound 5 but their difference in chemical structure is only that there is a methyl group on the C15 for compound 6 and none but hydrogen atom on the C15 for compound 5, indicated that a methyl group plays an inhibitory role to the fungicidal activity. It suggests that the existence of a methyl group with a great volume between two polarizable groups would interfere in the interaction of pesticide molecules and the target enzyme.

No Overt Nucleosome Eviction at Deprotected Telomeres

Molecular and Cellular Biology. Sep, 2008  |  Pubmed ID: 18625717

Dysfunctional telomeres elicit the canonical DNA damage response, which includes the activation of the ATM or ATR kinase signaling pathways and end processing by nonhomologous end joining (NHEJ) or homologous recombination (HR). The cellular response to DNA double-strand breaks has been proposed to involve chromatin remodeling and nucleosome eviction, but whether dysfunctional telomeres undergo chromatin reorganization is not known. Here, we report on the nucleosomal organization of telomeres that have become deprotected through the deletion of the shelterin components TRF2 or POT1. We found no evidence of changes in the nucleosomal organization of the telomeric chromatin or nucleosome eviction near the telomere terminus. An unaltered chromatin structure was observed at telomeres lacking TRF2, which activate the ATM kinase and are a substrate for NHEJ. Similarly, telomeres lacking POT1a and POT1b, which activate the ATR kinase, showed no overt nucleosome eviction. Finally, telomeres lacking TRF2 and Ku70, which are processed by HR, appeared to maintain their original nucleosomal organization. We conclude that ATM signaling, ATR signaling, NHEJ, and HR at deprotected telomeres can take place in the absence of overt nucleosome eviction.

Interactions Between SIRT1 and AP-1 Reveal a Mechanistic Insight into the Growth Promoting Properties of Alumina (Al2O3) Nanoparticles in Mouse Skin Epithelial Cells

Carcinogenesis. Oct, 2008  |  Pubmed ID: 18676681

The physicochemical properties of nanomaterials differ from those of the bulk material of the same composition. However, little is known about the underlying effects of these particles in carcinogenesis. The purpose of this study was to determine the mechanisms involved in the carcinogenic properties of nanoparticles using aluminum oxide (Al(2)O(3)/alumina) nanoparticles as the prototype. Well-established mouse epithelial JB6 cells, sensitive to neoplastic transformation, were used as the experimental model. We demonstrate that alumina was internalized and maintained its physicochemical composition inside the cells. Alumina increased cell proliferation (53%), proliferating cell nuclear antigen (PCNA) levels, cell viability and growth in soft agar. The level of manganese superoxide dismutase, a key mitochondrial antioxidant enzyme, was elevated, suggesting a redox signaling event. In addition, the levels of reactive oxygen species and the activities of the redox sensitive transcription factor activator protein-1 (AP-1) and a longevity-related protein, sirtuin 1 (SIRT1), were increased. SIRT1 knockdown reduces DNA synthesis, cell viability, PCNA levels, AP-1 transcriptional activity and protein levels of its targets, JunD, c-Jun and BcL-xl, more than controls do. Immunoprecipitation studies revealed that SIRT1 interacts with the AP-1 components c-Jun and JunD but not with c-Fos. The results identify SIRT1 as an AP-1 modulator and suggest a novel mechanism by which alumina nanoparticles may function as a potential carcinogen.

The Potassium Ion Channel Opener NS1619 Inhibits Proliferation and Induces Apoptosis in A2780 Ovarian Cancer Cells

Biochemical and Biophysical Research Communications. Oct, 2008  |  Pubmed ID: 18706395

Diverse types of voltage-gated potassium (K+) channels have been shown to be involved in regulation of cell proliferation. The maxi-conductance Ca2+-activated K+ channels (BK channels) may play an important role in the progression of human cancer. To explore the role of BK channels in regulation of apoptosis in human ovarian cancer cells, the effects of the specific BK channel activator NS1619 on induction of apoptosis in A2780 cells were observed. Following treatment with NS1619, cell proliferation was measured by MTT assay. Apoptosis of A2780 cells pretreated with NS1619 was detected by agarose gel electrophoresis of cellular DNA and flow cytometry. Our data demonstrate that NS1619 inhibits the proliferation of A2780 cells in a dosage and time dependent manner IC50=31.1 microM, for 48 h pretreatment and induces apoptosis. Western blot analyses showed that the anti-proliferation effect of NS1619 was associated with increased expression of p53, p21, and Bax. These results indicate that BK channels play an important role in regulating proliferation of human ovarian cancer cells and may induce apoptosis through induction of p21(Cip1) expression in a p53-dependent manner.

Preparation of Active and Robust Palladium Nanoparticle Catalysts Stabilized by Diamine-functionalized Mesoporous Polymers

Chemical Communications (Cambridge, England). Dec, 2008  |  Pubmed ID: 19048134

A two-step chemical modification process is designed for synthesizing novel diamine-functionalized mesopolymers, which combine the advantage of organic polymers and mesoporous materials, and serve as an efficient scaffold for supporting highly dispersed, catalytically active and robust Pd nanoparticles (NPs).

Synthesis, Biological Evaluation and Quantitative Structure-activities Relationship of Flavonoids As Vasorelaxant Agents

Bioorganic & Medicinal Chemistry. Jan, 2009  |  Pubmed ID: 19070497

A series of flavonoid derivatives were designed, synthesized. Their vasorelaxant activities were evaluated experimentally against rat aorta rings pretreated with phenylephrine (PE). Among them, 6-hydroxy-8-allyl-4'-chloro-flavanone 8q exhibited the highest vasodilatory activity (EC(50)=4.6 microM, E(max)=95.1%). The 3D-QSAR analysis was carried out by comparative molecular field analysis (CoMFA) method, and a statistically reliable model with good predictive power (r(2)=0.872 and q(cv)(2)=0.496) was established. The contour plots of CoMFA model provide a good insight into the structure-activity relationships of these compounds and may be used to design more potent flavonoids derivatives as vasorelaxant agents.

The Pro-angiogenic Factors Stimulated by Human Papillomavirus Type 16 E6 and E7 Protein in C33A and Human Fibroblasts

Oncology Reports. Jan, 2009  |  Pubmed ID: 19082439

To investigate the pro-angiogenic factors stimulated by human papillomavirus type 16 E6 and E7 protein in C33A and human fibroblasts. HPV-16 E6 and E7 genes were transfected into C33A and HFB to detect the profiling of angiogenesis-associated factors with the TranSignal angiogenesis antibody array. The mRNA and protein levels of the cytokines were examined by traditional RT-PCR and Western blotting in both cell lines before and after transfection of HPV-16 E6 and E7. HPV-16 E6 and E7 genes were successfully transfected into C33A and HFB cells. On the sheet of antibody array, after transfection of HPV-16 E6 and E7, 6 other cytokines, Ang-1, FGFalpha, HGF, IL-6, IP-10 and PIGF besides VEGF, were detected at higher levels in C33A cells. Expression of 7 other cytokines besides IL-8, Ang-1, IL-1alpha, IL-1beta, HGF, IL-6, VEGF and PIGF increased in HFB cells. The common cytokines in both cell lines were Ang-1, HGF, PIGF and VEGF. The mRNA and protein levels of the four cytokines were verified to increase by traditional RT-PCR and Western blotting in both cell lines after transfection of HPV-16 E6 and E7. Multiple pro-angiogenic cytokines could be stimulated by HPV-16 E6 and E7 protein both in cervical cancer cell line and normal human diploid cells. Anti-angiogenesis therapy may be effective alone or in combination with biologic means aimed at E6 and E7 in the treatment of cervical cancer.

Boron Nitride Nanotubes Are Noncytotoxic and Can Be Functionalized for Interaction with Proteins and Cells

Journal of the American Chemical Society. Jan, 2009  |  Pubmed ID: 19119844

We report the discovery that boron nitride nanotubes (BNNTs), isosteres of CNTs with unique physical properties, are inherently noncytotoxic. Furthermore, we developed a biomemetic coating strategy to interface BNNTs with proteins and cells. Finally, we showed that BNNTs can deliver DNA oligomers to the interior of cells with no apparent toxicity. This work suggests that BNNTs may be superior to CNTs for use as biological probes and in biomaterials.

Comparison of Tungsten Coil Electrothermal Vaporization and Thermospray Sample Introduction Methods for Flame Furnace Atomic Absorption Spectrometry

Talanta. Mar, 2009  |  Pubmed ID: 19159798

Flame furnace atomic absorption spectrometry (FF-AAS) is a newly developed flame atomic absorption spectrometric technique based on arranging a flame furnace onto the top of the flame burner head. In this fundamental investigation, 25 elements were carefully tested by using either thermospray FF-AAS or tungsten coil electrothermal vaporization FF-AAS, of which 15 volatile and semi-volatile elements (Cd, Tl, Ag, Pb, Zn, Hg, Cu, Sb, Bi, Te, In, As, Se, Sn and Au) exhibited better limits of detection compared to those by conventional FAAS; however, non-volatile or refractory elements (Fe, Co, Ni, Cr, Mn, Pd, Pt, Al, Be and V) showed inferior sensitivities by the proposed methods.

Site-specific Chemical Modification of Recombinant Proteins Produced in Mammalian Cells by Using the Genetically Encoded Aldehyde Tag

Proceedings of the National Academy of Sciences of the United States of America. Mar, 2009  |  Pubmed ID: 19202059

The properties of therapeutic proteins can be enhanced by chemical modification. Methods for site-specific protein conjugation are critical to such efforts. Here, we demonstrate that recombinant proteins expressed in mammalian cells can be site-specifically modified by using a genetically encoded aldehyde tag. We introduced the peptide sequence recognized by the endoplasmic reticulum (ER)-resident formylglycine generating enzyme (FGE), which can be as short as 6 residues, into heterologous proteins expressed in mammalian cells. Cotranslational modification of the proteins by FGE produced products bearing a unique aldehyde group. Proteins bearing this "aldehyde tag" were chemically modified by selective reaction with hydrazide- or aminooxy-functionalized reagents. We applied the technique to site-specific modification of monoclonal antibodies, the fastest growing class of biopharmaceuticals, as well as membrane-associated and cytosolic proteins expressed in mammalian cells.

Cyclometalated Platinum(II) Complexes As Highly Sensitive Luminescent Switch-on Probes for Practical Application in Protein Staining and Cell Imaging

Chemistry (Weinheim an Der Bergstrasse, Germany). 2009  |  Pubmed ID: 19204965

Protein-staining platinum: The luminescent switch-on characteristic of the platinum(II) complex can be utilized for staining a series of proteins in sodium dodecyl sulfate-polyarcylamide gels, to give emissive gel images directly under UV light (see figure). The detection sensitivity for BSA protein is down to 6.0 ng, revealing potential practical applications of luminescent platinum(II) complexes in the luminescent signaling of biomolecules.

Efficient Hydrogenation of Benzaldehydes over Mesopolymer-entrapped Pt Nanoparticles in Water

Chemistry, an Asian Journal. May, 2009  |  Pubmed ID: 19253925

Pt nanoparticles entrapped in the matrices of FDU-14 periodic mesoporous organic polymer (abbreviated as mesopolymer), prepared by a simple and facile method, serve as an efficient catalyst for the liquid-phase hydrogenation of benzaldehydes under mild conditions. Water was confirmed to be a better choice of solvent for the hydrogenation of benzaldehydes on the Pt/FDU-14 catalyst. The highest activity (turnover frequency) was about 5700 mol mol(-1) h(-1) for 3-fluorobenzaldehyde hydrogenation in water and no distinct loss of activity or selectivity was observed after the catalyst was recycled nine times. For the para-substituted benzaldehydes, the catalytic performance of Pt/FDU-14 was superior to the commercial Pt/alumina catalyst owing to the more hydrophobic nature of the FDU-based catalyst.

Inorganic Arsenic Speciation Analysis of Water Samples by Trapping Arsine on Tungsten Coil for Atomic Fluorescence Spectrometric Determination

Talanta. May, 2009  |  Pubmed ID: 19269445

Arsine trapping on resistively heated tungsten coil was investigated and an analytical method for ultratrace arsenic determination in environmental samples was established. Several chemical modifiers, including Re, Pt, Mo, Ta and Rh, were explored as permanent chemical modifiers for tungsten coil on-line trapping and Rh gave the best performance. Arsine was on-line trapped on Rh-coated tungsten coil at 640 degrees C, then released at 1930 degrees C and subsequently delivered to an atomic fluorescence spectrometer (AFS) by a mixture of Ar and H(2) for measurement. In the medium of 2% (v/v) HCl and 3% (m/v) KBH(4), arsine can be selectively generated from As(III). Total inorganic arsenic was determined after pre-reduction of As(V) to As(III) in 0.5% (m/v) thiourea-0.5% (m/v) ascorbic acid solution. The concentration of As(V) was calculated by difference between the total inorganic arsenic and As(III), and inorganic arsenic speciation was thus achieved. With 8 min on-line trapping, the limit of detection was 10 ng L(-1) for As(III) and 9 ng L(-1) for total As; and the precision was found to be <5% R.S.D. (n=7) for 0.2 ng mL(-1) As. The proposed method was successfully applied in total arsenic determination of several standard reference materials and inorganic arsenic speciation analysis of nature water samples.

PI3K Inhibitors for Cancer Therapy: What Has Been Achieved So Far?

Current Medicinal Chemistry. 2009  |  Pubmed ID: 19275602

PI3K is a large duel lipid and protein kinase that catalyzes phosphorylation of the 3-hydroxyl position of phosphatidylinositides (PIs) and plays a crucial role in the cellular signaling network. Inhibition of the phosphatidylinositol 3-kinase (PI3K) signaling pathway is a newly identified strategy for the discovery and development of certain therapeutic agents. Among the various subtypes of PI3K, class IA PI3Kalpha has gained increasing attention as a promising drug target for the treatment of cancer due to its frequent mutations and amplifications in various human cancers. Here, we discuss the insights gained so far relevant to the development of PI3K inhibitors for the treatment of human cancers. Emphasis is on the structure-activity relationship of PI3K inhibitors which bear the most significant PI3Kalpha inhibitory activities. We also highlight PI3K inhibitors that are currently under clinical trials for cancers.

Discovery and Identification of Potential Biomarkers of Pediatric Acute Lymphoblastic Leukemia

Proteome Science. 2009  |  Pubmed ID: 19291297

Acute lymphoblastic leukemia (ALL) is a common form of cancer in children. Currently, bone marrow biopsy is used for diagnosis. Noninvasive biomarkers for the early diagnosis of pediatric ALL are urgently needed. The aim of this study was to discover potential protein biomarkers for pediatric ALL.

Simultaneous Removal of Coexistent Heavy Metals from Simulated Urban Stormwater Using Four Sorbents: a Porous Iron Sorbent and Its Mixtures with Zeolite and Crystal Gravel

Journal of Hazardous Materials. Sep, 2009  |  Pubmed ID: 19303211

The selectivity sequence and removal of coexistent heavy metals (namely As, Cd, Cr, Cu, Ni and Zn) in synthetic urban stormwater runoff were investigated by adsorption onto a porous iron sorbent (namely P1) and its mixtures with zeolite and crystal gravel, respectively (namely P2, P3, and P4). A batch method was employed to simulate the sorption processes. The geochemical model PHREEQC was used to calculate the metals' species and saturation data for elucidating the sorption data. The equilibrium data demonstrated a good fit with the Freundlich model and showed affinity in the orders: Cd>Zn>Ni>Cu>As>Cr (sorbents P1, P3 and P4) and Cd>Zn>Ni>As>Cu>Cr (sorbent P2). In addition to this, Calculated Distribution Coefficient (K(d)) values were used to compare the overall heavy metal removal efficiencies of the sorbents, which, in decreasing order, was found to be P4>P1>P2>P3. In comparing these four commercial sorbents, sorbent P4 represents a promising material for treatment of urban stormwater runoff containing mixed heavy metals.

Metabolic Labeling of Sialic Acids in Living Animals with Alkynyl Sugars

Angewandte Chemie (International Ed. in English). 2009  |  Pubmed ID: 19388017

Sialome sweet sialome: As sialic acids are involved in many host-pathogen recognition events and are markers of embryonic and malignant tissues, there is great interest in methods for the enrichment and identification of sialylated glycoproteins from complex tissues. Now N-(4-pentynoyl)mannosamine can be used to metabolically label sialylated glycoproteins in living animals, enabling future identification of new biomarkers.

Glycopeptide-preferring Polypeptide GalNAc Transferase 10 (ppGalNAc T10), Involved in Mucin-type O-glycosylation, Has a Unique GalNAc-O-Ser/Thr-binding Site in Its Catalytic Domain Not Found in PpGalNAc T1 or T2

The Journal of Biological Chemistry. Jul, 2009  |  Pubmed ID: 19460755

Mucin-type O-gly co sy la tion is initiated by a large family of UDP-GalNAc:polypeptide alpha-N-acetylgalactosaminyltransferases (ppGalNAc Ts) that transfer GalNAc from UDP-GalNAc to the Ser and Thr residues of polypeptide acceptors. Some members of the family prefer previously gly co sylated peptides (ppGalNAc T7 and T10), whereas others are inhibited by neighboring gly co sy la tion (ppGalNAc T1 and T2). Characterizing their peptide and glycopeptide substrate specificity is critical for understanding the biological role and significance of each isoform. Utilizing a series of random peptide and glycopeptide substrates, we have obtained the peptide and glycopeptide specificities of ppGalNAc T10 for comparison with ppGalNAc T1 and T2. For the glycopeptide substrates, ppGalNAc T10 exhibited a single large preference for Ser/Thr-O-GalNAc at the +1 (C-terminal) position relative to the Ser or Thr acceptor site. ppGalNAc T1 and T2 revealed no significant enhancements suggesting Ser/Thr-O-GalNAc was inhibitory at most positions for these isoforms. Against random peptide substrates, ppGalNAc T10 revealed no significant hydrophobic or hydrophilic residue enhancements, in contrast to what has been reported previously for ppGalNAc T1 and T2. Our results reveal that these transferases have unique peptide and glycopeptide preferences demonstrating their substrate diversity and their likely roles ranging from initiating transferases to filling-in transferases.

[Construction of Anti-sense CDNA Library of Human Breast Cancer Cells During Apoptosis Induced by Trichostatin A and Preliminary Screening of Essential Genes]

Zhonghua Yi Xue Za Zhi. Feb, 2009  |  Pubmed ID: 19567099

To construct an anti-sense cDNA library of human breast cancer cells to screen essential genes with anti-tumor effects on apoptosis of human breast cancer cells induced by trichostatin A.

[Screening and Identification Analysis of Serum Protein Biomarkers in Nephroblastoma]

Zhonghua Yi Xue Za Zhi. May, 2009  |  Pubmed ID: 19595180

To screen and characterize the serum protein biomarkers in nephroblastoma so as to establish the proteins as the specific serum biomarkers for diagnosis and prognosis monitoring.

[Detection and Identification of Specific Serum Biomarkers in Papillary Thyroid Cancer]

Zhonghua Zhong Liu Za Zhi [Chinese Journal of Oncology]. Apr, 2009  |  Pubmed ID: 19615280

To detect and identify the potential specific serum biomarkers for diagnosis of papillary thyroid cancer.

CYP-omega-hydroxylation-dependent Metabolites of Arachidonic Acid Inhibit the Basolateral 10 PS Chloride Channel in the Rat Thick Ascending Limb

Kidney International. Oct, 2009  |  Pubmed ID: 19641481

Metabolites of arachidonic acid influence sodium chloride (NaCl) transport in the thick ascending limb. Because a 10 pS Cl channel is the major type of chloride channel in the basolateral membrane of this nephron segment, we explored the effect of arachidonic acid on this channel in cell-attached patches. Addition of 5 micromol arachidonic acid significantly decreased channel activity (a product of channel number and open probability) while linoleic acid had no effect. To determine if this was mediated by acachidonic acid per se or by its metabolites, we measured channel activity in the presence of the cyclooxygenase inhibitor indomethacin, the selective lipoxygenase inhibitor nordihydroguaiaretic acid, and the cytochrome P-450 (CYP)-omega-hydroxylation inhibitor 17-octadecynoic acid. Neither cyclooxygenase nor lipoxygenase inhibition had an effect on basal chloride channel activity; further they failed to abolish the inhibitory effect of arachidonate on the 10 pS channel. However, inhibition of CYP-omega-hydroxylation completely abolished the effect of arachidonic acid. The similarity of the effects of 20-hydroxyeicosatetraenoic acid (20-HETE) and arachidonic acid suggests that the effect of arachidonic acid was mediated by CYP-omega-hydroxylation-dependent metabolites. We conclude that arachidonic acid inhibits the 10 pS chloride channel in the basolateral membrane of the medullary thick ascending limb, an effect mediated by the CYP-omega-hydroxylation-dependent metabolite 20-HETE.

[Surgical Correction of Concealed Penis]

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi = Zhongguo Xiufu Chongjian Waike Zazhi = Chinese Journal of Reparative and Reconstructive Surgery. Jul, 2009  |  Pubmed ID: 19662981

To discuss the severity grading and procedure design of concealed penis.

Human Telomerase Caught in the Act

Cell. Aug, 2009  |  Pubmed ID: 19665967

Based on prior work, it was expected that telomerase would preferentially elongate the shortest telomeres in a cell, extending the telomeric G-rich strand through a process that is coupled to the synthesis of the complementary strand. Contrary to this view, Zhao et al. (2009) now show that telomerase in human cancer cells extends most telomeres during every S phase and that complementary strand synthesis does not immediately follow telomerase action.

Restoration of DLC1 Gene Inhibits Proliferation and Migration of Human Colon Cancer HT29 Cells

Annals of Clinical and Laboratory Science. 2009  |  Pubmed ID: 19667410

DLC1 (deleted in liver cancer-1) is a new candidate tumor suppressor gene, which is inactive in various types of human cancers including colon cancer. To study the function of DLC1, we constructed a pcDNA3.1 vector containing the DLC1 gene and transfected it into HT29 colon cancer cells that were deficient in DLC1 expression. The restoration of DLC1 expression in HT29 cells significantly inhibited cell proliferation and migration. Flow cytometry showed that DLC1 transfection into HT29 cells induced apoptosis and that the cell cycle was arrested at S-phase. Additionally, cyclinD1 mRNA and protein expression were down-regulated while p21 expression was increased in pcDNA3.1-DLC1-HT29 cells compared to wild HT29 cells. These results confirm the role of DLC1 gene as a tumor suppressor, which may be manifested by regulation of p21 and cyclinDl. The DLC1 gene has a potential therapeutic role in inhibiting the development of colon cancer.

Proteomic Analysis of Mitochondria from Caenorhabditis Elegans

Proteomics. Oct, 2009  |  Pubmed ID: 19670372

Mitochondria play essential roles in cell physiological processes including energy production, metabolism, ion homeostasis, cell growth, aging and apoptosis. Proteomic strategies have been applied to the study of mitochondria since 1998; these studies have yielded decisive information about the diverse physiological functions of the organelle. As an ideal model biological system, the nematode Caenorhabditis elegans has been widely used in the study of several diseases, such as metabolic diseases and cancer. However, the mitochondrial proteome of C. elegans remains elusive. In this study, we purified mitochondria from C. elegans and performed a comprehensive proteomic analysis using the shotgun proteomic approach. A total of 1117 proteins have been identified with at least two unique peptides. Their physicochemical and functional characteristics, subcellular locations, related biological processes, and associations with human diseases, especially Parkinson's disease, are discussed. An orthology comparison was also performed between C. elegans and four other model organisms for a general depiction of the conservation of mitochondrial proteins during evolution. This study will provide new clues for understanding the role of mitochondria in the physiological and pathological processes of C. elegans.

[Effects of High-density Lipoprotein 1 on the Formation of Foam Cells from Human Monocyte-derived Macrophages]

Zhonghua Xin Xue Guan Bing Za Zhi. Feb, 2009  |  Pubmed ID: 19719996

To investigate effects of serum HDL(1) on the formation of foam cells from human peripheral blood monocyte-derived macrophages.

Determination of Cadmium in Rice and Water by Tungsten Coil Electrothermal Vaporization-atomic Fluorescence Spectrometry and Tungsten Coil Electrothermal Atomic Absorption Spectrometry After Cloud Point Extraction

Analytica Chimica Acta. Sep, 2009  |  Pubmed ID: 19720169

In this work, the microsampling nature of tungsten coil electrothermal vaporization Ar/H(2) flame atomic fluorescence spectrometry (W-coil ETV-AFS) as well as tungsten coil electrothermal atomic absorption spectrometry (W-coil ET-AAS) was used with cloud point extraction (CPE) for the ultrasensitive determination of cadmium in rice and water samples. When the temperature of the extraction system is higher than the cloud point temperature of the selected surfactant Triton X-114, the complex of cadmium with dithizone can be quantitatively extracted into the surfactant-rich phase and subsequently separated from the bulk aqueous phase by centrifugation. The main factors affecting the CPE, such as concentration of Triton X-114 and dithizone, pH, equilibration temperature and incubation time, were optimized for the best extract efficiency. Under the optimal conditions, the limits of detection for cadmium by W-coil ETV-AFS and W-coil ET-AAS were 0.01 and 0.03 microg L(-1), with sensitivity enhancement factors of 152 and 93, respectively. The proposed methods were applied to the determination of cadmium in certified reference rice and water samples with analytical results in good agreement with certified values.

Effects of Room-temperature Ionic Liquids on the Chemical Vapor Generation of Gold: Mechanism and Analytical Application

Analytica Chimica Acta. Sep, 2009  |  Pubmed ID: 19720174

To get insight into the mechanism of the effect of room-temperature ionic liquids (RTILs) on the chemical vapor generation (CVG) of noble metals, gold was taken as a model element, and eight RTILs were examined. All the RTILs resulted in 3-24 times improvement in sensitivity for Au, depending on their nature. For the RTILs with identical anion, the RTILs with the cations of short chain exhibited better enhancement effect than those with long alkyl chain length or complex branch chain. For the RTILs with identical cation, the RTILs with Br(-) gave the best enhancement effect. The formation of ion pairs between the cation of RTILs and the anion species of gold via electrostatic interaction, and/or the substitution of the Cl(-) in the anion species of gold by the anion of RTILs likely enabled a more effective CVG reaction to occur. The RTILs also facilitated the generation of small bubbles and provided an electrostatic stabilization to protect the unstable volatile gold species and to help fast isolation of volatile gold species from the reaction mixture. 1-Butyl-3-methylimidazolium tetrafluoroborate [C(4)mim]Br gave the best improvement in the sensitivity (24 times) among the RTILs studied, and also reduced the interferences from common transition and other noble metals. Based on the enhancement effect of [C(4)mim]Br, a novel flow injection-CVG-atomic fluorescence spectrometric method with a detection limit (3 s) of 1.9 microg L(-1) and a precision of 3.1% (50 microg L(-1), RSD, n=11) was developed for the determination of trace gold in geological samples.

Discovery and Identification of Potential Biomarkers of Papillary Thyroid Carcinoma

Molecular Cancer. 2009  |  Pubmed ID: 19785722

Thyroid carcinoma is the most common endocrine malignancy and a common cancer among the malignancies of head and neck. Noninvasive and convenient biomarkers for diagnosis of papillary thyroid carcinoma (PTC) as early as possible remain an urgent need. The aim of this study was to discover and identify potential protein biomarkers for PTC specifically.

Synergetic Enhancement Effect of Ionic Liquid and Diethyldithiocarbamate on the Chemical Vapor Generation of Nickel for Its Atomic Fluorescence Spectrometric Determination in Biological Samples

Analytica Chimica Acta. Oct, 2009  |  Pubmed ID: 19786174

Room-temperature ionic liquid in combination with sodium diethyldithiocarbamate (DDTC) was used to synergetically improve the chemical vapor generation (CVG) of nickel. Volatile species of nickel were effectively generated through reduction of acidified analyte solution with KBH(4) in the presence of 0.02% DDTC and 25mmolL(-1) 1-butyl-3-methylimidazolium bromide ([C(4)mim]Br) at room temperature. Thus, a new flow injection (FI)-CVG-atomic fluorescence spectrometric (FI-CVG-AFS) method was developed for determination of nickel with a detection limit of 0.65microgL(-1) (3s) and a sampling frequency of 180h(-1). With consumption of 0.5mL sample solution, an enhancement factor of 2400 was obtained. The precision (RSD) for eleven replicate determinations of 20microgL(-1) Ni was 3.4%. The developed FI-CVG-AFS method was successfully applied to determination of trace Ni in several certified biological reference materials.

Chemoenzymatic Synthesis of GDP-L-fucose and the Lewis X Glycan Derivatives

Proceedings of the National Academy of Sciences of the United States of America. Sep, 2009  |  Pubmed ID: 19805264

Lewis X (Le(x))-containing glycans play important roles in numerous cellular processes. However, the absence of robust, facile, and cost-effective methods for the synthesis of Le(x) and its structurally related analogs has severely hampered the elucidation of the specific functions of these glycan epitopes. Here we demonstrate that chemically defined guanidine 5'-diphosphate-beta-l-fucose (GDP-fucose), the universal fucosyl donor, the Le(x) trisaccharide, and their C-5 substituted derivatives can be synthesized on preparative scales, using a chemoenzymatic approach. This method exploits l-fucokinase/GDP-fucose pyrophosphorylase (FKP), a bifunctional enzyme isolated from Bacteroides fragilis 9343, which converts l-fucose into GDP-fucose via a fucose-1-phosphate (Fuc-1-P) intermediate. Combining the activities of FKP and a Helicobacter pylori alpha1,3 fucosyltransferase, we prepared a library of Le(x) trisaccharide glycans bearing a wide variety of functional groups at the fucose C-5 position. These neoglycoconjugates will be invaluable tools for studying Le(x)-mediated biological processes.

Stabilization of G-quadruplex DNA with Platinum(II) Schiff Base Complexes: Luminescent Probe and Down-regulation of C-myc Oncogene Expression

Chemistry (Weinheim an Der Bergstrasse, Germany). Dec, 2009  |  Pubmed ID: 19876976

The interactions of a series of platinum(II) Schiff base complexes with c-myc G-quadruplex DNA were studied. Complex [PtL(1a)] (1 a; H(2)L(1a)=N,N'-bis(salicylidene)-4,5-methoxy-1,2-phenylenediamine) can moderately inhibit c-myc gene promoter activity in a cell-free system through stabilizing the G-quadruplex structure and can inhibit c-myc oncogene expression in cultured cells. The interaction between 1 a and G-quadruplex DNA has been examined by (1)H NMR spectroscopy. By using computer-aided structure-based drug design for hit-to-lead optimization, an in silico G-quadruplex DNA model has been constructed for docking-based virtual screening to develop new platinum(II) Schiff base complexes with improved inhibitory activities. Complex [PtL(3)] (3; H(2)L(3)=N,N'-bis{4-[1-(2-propylpiperidine)oxy]salicylidene}-4,5-methoxy-1,2-phenylenediamine) has been identified with a top score in the virtual screening. This complex was subsequently prepared and experimentally tested in vitro for its ability to stabilize or induce the formation of the c-myc G-quadruplex. The inhibitory activity of 3 (IC(50)=4.4 muM) is tenfold more than that of 1 a. The interaction between 1 a or 3 with c-myc G-quadruplex DNA has been examined by absorption titration, emission titration, molecular modeling, and NMR titration experiments, thus revealing that both 1 a and 3 bind c-myc G-quadruplex DNA through an external end-stacking mode at the 3' terminal face of the G-quadruplex. Such binding of G-quadruplex DNA with 3 is accompanied by up to an eightfold increase in the intensity of photoluminescence at lambda(max)=652 nm. Complex 3 also effectively down-regulated the expression of c-myc in human hepatocarcinoma cells.

Identification of LIV1, a Putative Zinc Transporter Gene Responsible for HDACi-induced Apoptosis, Using a Functional Gene Screen Approach

Molecular Cancer Therapeutics. Nov, 2009  |  Pubmed ID: 19887557

Histone deacetylase inhibitors (HDACi) show promise as a novel class of antitumoral agents and have shown the ability to induce apoptosis of tumor cells. To gain a better understanding of the action of HDACi, we conducted a functional gene screen approach named suppression of mortality by antisense rescue technique to identify the key genes responsible for the tumor-selective killing trichostatin A. Over 20 genes associated with HDACi-induced mortality were identified. One of the confirmed positive hits is LIV1, a putative zinc transporter. LIV1 is significantly induced by treatment with HDACi in a number of tumor cells, but not in normal cells. Knockdown of LIV1 suppressed apoptosis induced by HDACi in tumor cells. Although HDACi induced a slight increase in the free intracellular zinc concentration, knockdown of LIV1 significantly enhanced the intracellular zinc level, which was associated with resistance to apoptosis. On the other hand, pretreatment of the cells with a specific zinc chelator TPEN reversed the apoptosis resistance conferred by knockdown of LIV1. However, the biological effects of TPEN were abolished by addition of physiologic concentrations of zinc. Taken together, the present study identifies LIV1 as a critical mediator responsible for HDACi-induced apoptosis. The effect of LIV1 is, at least in part, mediated by affecting intracellular zinc homeostasis, which may be related to alteration of the catalytic activity of the Caspase 3 and expression of some BCL-2 family genes. As such, these findings highlight a novel mechanism underlying the action of HDACi that could be potentially useful in the clinical setting.

Systematic Errors Analysis for a Large Dynamic Range Aberrometer Based on Aberration Theory

Applied Optics. Nov, 2009  |  Pubmed ID: 19904333

In Ref. 1, it was demonstrated that the significant systematic errors of a type of large dynamic range aberrometer are strongly related to the power error (defocus) in the input wavefront. In this paper, a generalized theoretical analysis based on vector aberration theory is presented, and local shift errors of the SH spot pattern as a function of the lenslet position and the local wavefront tilt over the corresponding lenslet are derived. Three special cases, a spherical wavefront, a crossed cylindrical wavefront, and a cylindrical wavefront, are analyzed and the possibly affected Zernike terms in the wavefront reconstruction are investigated. The simulation and experimental results are illustrated to verify the theoretical predictions.

Systematic Error of a Large Dynamic Range Aberrometer

Applied Optics. Nov, 2009  |  Pubmed ID: 19904339

Shack-Hartmann aberrometers are routinely used for measuring ocular aberrations. In one configuration, the intermediate images of the Shack-Hartmann spots formed by the lenslet array are relayed by an imaging lens onto a sensor. A systematic introduction of spherical aberration that is strongly related to the power error (defocus) of the incident wavefront is observed in this configuration. We found that the largest component of this error is induced by the pupil aberration of the imaging relay lens. Some simulations and experimental results are demonstrated.

Preparation, Characterization and Photocatalytic Activities of Holmium-doped Titanium Dioxide Nanoparticles

Journal of Hazardous Materials. Jan, 2009  |  Pubmed ID: 18462878

Holmium-doped TiO2 nanoparticles with high photocatalytic activities were prepared by sol-gel method and characterized by X-ray diffraction, transmission electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy, and surface area measurement by nitrogen adsorption in this study. Experimental results indicated holmium doping could increase the surface area of TiO2 nanoparticles, and inhibit the growth of crystalline size and the anatase-to-rutile phase transformation. The results of photodegrading methyl orange showed holmium doping improved the photocatalytic activity of TiO2, and the reasons could be attributed to the synergetic effects of large surface areas, small crystallite size, lattice distortion and more charge imbalance of holmium-doped TiO2. In our experiment, the optimal doped amount was 0.3mol.% for the maximum photocatalytic degradation ratio when holmium-doped TiO2 was calcined at 500 degrees C, and the optimal calcined temperature was 600 degrees C when the doped amount was 0.5mol.%.

CtIP Links DNA Double-strand Break Sensing to Resection

Molecular Cell. Dec, 2009  |  Pubmed ID: 20064462

In response to DNA double-strand breaks (DSBs), cells sense the DNA lesions and then activate the protein kinase ATM. Subsequent DSB resection produces RPA-coated ssDNA that is essential for activation of the DNA damage checkpoint and DNA repair by homologous recombination (HR). However, the biochemical mechanism underlying the transition from DSB sensing to resection remains unclear. Using Xenopus egg extracts and human cells, we show that the tumor suppressor protein CtIP plays a critical role in this transition. We find that CtIP translocates to DSBs, a process dependent on the DSB sensor complex Mre11-Rad50-NBS1, the kinase activity of ATM, and a direct DNA-binding motif in CtIP, and then promotes DSB resection. Thus, CtIP facilitates the transition from DSB sensing to processing: it does so by binding to the DNA at DSBs after DSB sensing and ATM activation and then promoting DNA resection, leading to checkpoint activation and HR.

Conjugation of Glucose Oxidase Onto Mn-doped ZnS Quantum Dots for Phosphorescent Sensing of Glucose in Biological Fluids

Analytical Chemistry. Feb, 2010  |  Pubmed ID: 20092317

Integrating various enzymes with nanomaterials provides various nanohybrids with new possibilities in biosensor applications. Furthermore, the enzymatic activity and stability are also improved due to the large surface area of nanomaterials. Here we report the conjugation of glucose oxidase (GOD) onto phosphorescent Mn-doped ZnS quantum dots (QDs) using 1-ethyl-3-(3-dimethylaminopropy)carbodiimide (EDC)/N-hydroxysuccinimide (NHS) as coupling reagents for glucose biosensing based on the effective quenching of the room temperature phosphorescence (RTP) of Mn-doped ZnS QDs by the H(2)O(2) generated from GOD-catalyzed oxidation of glucose. The obtained bioconjugate not only provided improved enzymatic performance with Michaelis-Menten constant of 0.70 mM but also favored biological applications because the phosphorescent detection mode avoided the interference from autofluorescence and scattering light from the biological matrix. In addition, the GOD-conjugated Mn-doped ZnS QDs showed better thermal stability in the temperature range of 20-80 degrees C. The GOD-Mn-doped ZnS QDs based RTP sensor for glucose gave a detection limit of 3 microM and two linear ranges from 10 microM to 0.1 mM and from 0.1 to 1 mM. The developed biosensor was successfully applied to the determination of glucose in real serum samples without the need for any complicated sample pretreatments.

Structure of a Human Multidrug Transporter in an Inward-facing Conformation

Journal of Structural Biology. Jun, 2010  |  Pubmed ID: 20109555

Multidrug resistance protein 1 (ABCC1) is a member of the 'C' class of ATP-binding cassette transporters, which can give rise to resistance to chemotherapy via drug export from cells. It also acts as a leukotriene C4 transporter, and hence has a role in adaptive immune response. Most C-class members have an additional NH(2)-terminal transmembrane domain versus other ATP-binding cassette transporters, but little is known about the structure and role of this domain. Using electron cryomicroscopy of 2D crystals, data at 1/6per A(-1) resolution was generated for the full-length ABCC1 protein in the absence of ATP. Analysis using homologous structures from bacteria and mammals allowed the core transmembrane domains to be localised in the map. These display an inward-facing conformation and there is a noteworthy separation of the cytoplasmic nucleotide-binding domains. Examination of non-core features in the map suggests that the additional NH(2)-terminal domain has extensive contacts on one side of both core domains, and mirrors their inward-facing configuration in the absence of nucleotide.

Targeted Metabolic Labeling of Yeast N-glycans with Unnatural Sugars

Proceedings of the National Academy of Sciences of the United States of America. Mar, 2010  |  Pubmed ID: 20142501

Metabolic labeling of glycans with synthetic sugar analogs has emerged as an attractive means for introducing nonnatural chemical functionality into glycoproteins. However, the complexities of glycan biosynthesis prevent the installation of nonnatural moieties at defined, predictable locations within glycoproteins at high levels of incorporation. Here, we demonstrate that the conserved N-acetyglucosamine (GlcNAc) residues within chitobiose cores of N-glycans in the model organism Saccharomyces cerevisiae can be specifically targeted for metabolic replacement by unnatural sugars. We introduced an exogenous GlcNAc salvage pathway into yeast, allowing cells to metabolize GlcNAc provided as a supplement to the culture medium. We then rendered the yeast auxotrophic for production of the donor nucleotide-sugar uridine-diphosphate-GlcNAc (UDP-GlcNAc) by deletion of the essential gene GNA1. We demonstrate that gna1Delta strains require a GlcNAc supplement and that expression plasmids containing both exogenous components of the salvage pathway, GlcNAc transporter NGT1 from Candida albicans and GlcNAc kinase NAGK from Homo sapiens, are required for rescue in this context. Further, we show that cells successfully incorporate synthetic GlcNAc analogs N-azidoacetyglucosamine (GlcNAz) and N-(4-pentynoyl)-glucosamine (GlcNAl) into cell-surface glycans and secreted glycoproteins. To verify incorporation of the nonnatural sugars at N-glycan core positions, endoglycosidase H (endoH)-digested peptides from a purified secretory glycoprotein, Ygp1, were analyzed by mass spectrometry. Multiple Ygp1 N-glycosylation sites bearing GlcNAc, isotopically labeled GlcNAc, or GlcNAz were identified; these modifications were dependent on the supplement added to the culture medium. This system enables the production of glycoproteins that are functionalized for specific chemical modifications at their glycosylation sites.

Antiproliferative Effects of Volatile Oils from Centipeda Minima on Human Nasopharyngeal Cancer CNE Cells

Natural Product Communications. Jan, 2010  |  Pubmed ID: 20184042

Volatile oils from Centipeda minima extracted by steam distillation (SD) and supercritical fluid extraction (SFE) were investigated for their antiproliferative effects on the human nasopharyngeal cancer CNE cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay results showed that CNE cells were more susceptible to the SFE oil than to the SD oil. The IC50 values of the SFE oil were 56.6, 8.7 and 5.2 microg/mL after 24-, 48- and 72-h of treatment, respectively, whereas those of the SD oil were 123.5 microg/mL (24 h), 97.1 microg/mL (48 h) and 83.3 microg/mL (72 h). Mechanistic investigation revealed that SFE oil induced CNE cell death via induction of apoptosis by regulating the expression of the Bcl-2 family of proteins, resulting in the dysfunction of mitochondria, leading to the release of cytochrome c into the cytosol, which then activated caspase-9, and subsequently cleaved caspases-3 and -7. This study provided strong evidence for the anti-NPC potential of the SFE oil from C. minima.

Simultaneous and Selective Preconcentration of Trace Cu and Ag by One-step Displacement Cloud Point Extraction for FAAS Determination

Talanta. Apr, 2010  |  Pubmed ID: 20188966

A simple, rapid and selective one-step displacement cloud point extraction (D-CPE) procedure was developed for the simultaneous preconcentration of trace Cu and Ag followed by flame atomic absorption spectrometric (FAAS) measurement. In this proposed procedure, Ni-DDTC complex instead of DDTC was used to achieve one-step extraction. Since the stability of Cu-DDTC and Ag-DDTC is higher than that of Ni-DDTC, simultaneous preconcentration of Cu and Ag can be achieved in a single step. Up to 15,000 mg L(-1) Co(2+), 10,000 mg L(-1) Zn(2+), 5000 mg L(-1) Cd(2+) and 5000 mg L(-1) Al(3+) did not cause significant interferences for the determination of 50 microg L(-1) Cu by FAAS, while 8000 mg L(-1) Zn(2+), 4000 mg L(-1) Co(2+), 4000 mg L(-1) Cd(2+) and 5000 mg L(-1) Al(3+) had no distinct effect on the determination of 80 microg L(-1) Ag. The limits of detection (LODs) of 0.5 microg L(-1) for Cu and 1.0 microg L(-1) for Ag, respectively, were obtained by FAAS detection. The accuracy of the proposed method is validated by analyzing certified reference materials (GBW 07405, GBW 07311 and GBW 07260) with satisfactory results. Furthermore, the one-step D-CPE was also applied for the preconcentration/separation of Cu and Ag in high-purity salts and artificial seawater, followed by FAAS or inductively coupled plasma-mass spectrometry (ICP-MS) determination.

Enhanced MALDI-TOF MS Analysis of Phosphopeptides Using an Optimized DHAP/DAHC Matrix

Journal of Biomedicine & Biotechnology. 2010  |  Pubmed ID: 20339515

Selecting an appropriate matrix solution is one of the most effective means of increasing the ionization efficiency of phosphopeptides in matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). In this study, we systematically assessed matrix combinations of 2, 6-dihydroxyacetophenone (DHAP) and diammonium hydrogen citrate (DAHC), and demonstrated that the low ratio DHAP/DAHC matrix was more effective in enhancing the ionization of phosphopeptides. Low femtomole level of phosphopeptides from the tryptic digests of alpha-casein and beta-casein was readily detected by MALDI-TOF-MS in both positive and negative ion mode without desalination or phosphopeptide enrichment. Compared with the DHB/PA matrix, the optimized DHAP/DAHC matrix yielded superior sample homogeneity and higher phosphopeptide measurement sensitivity, particularly when multiple phosphorylated peptides were assessed. Finally, the DHAP/DAHC matrix was applied to identify phosphorylation sites from alpha-casein and beta-casein and to characterize two phosphorylation sites from the human histone H1 treated with Cyclin-Dependent Kinase-1 (CDK1) by MALDI-TOF/TOF MS.

Entry Screening to Delay Local Transmission of 2009 Pandemic Influenza A (H1N1)

BMC Infectious Diseases. 2010  |  Pubmed ID: 20353566

After the WHO issued the global alert for 2009 pandemic influenza A (H1N1), many national health agencies began to screen travelers on entry in airports, ports and border crossings to try to delay local transmission.

[Effects of Two Organic Pollutants on Biomarker System of Fish Lateolabrax Japonicus and the Pollution Assessment]

Huan Jing Ke Xue= Huanjing Kexue / [bian Ji, Zhongguo Ke Xue Yuan Huan Jing Ke Xue Wei Yuan Hui "Huan Jing Ke Xue" Bian Ji Wei Yuan Hui.]. Mar, 2010  |  Pubmed ID: 20358846

Responses of a select suite of protective enzymes in Lateolabrax japonicus including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (Gpx), reduced glutathione (GSH) glutathione S-transferase (GST), nitric oxide synthase (iNOS) in liver tissue and brain acetylcholinesterase (AChE), which could work as sensitively biochemical biomarkers were analyzed when exposed to different concentrations of sodium dodecylbenzene sulfonate (SDBS) and benzo[a]pyrene (B[a]P) under controlled laboratory conditions. Results showed that: (1) The biochemical biomarkers included in this investigation, different responses occurred in the enzymatic activities when exposed to different pollutants: the activities of SOD, GST, Gpx and GSH content were significantly induced by B[a]P (p < 0.05) while others present little different as compared to the control. Differently, SDBS exposure greatly affected the activities of CAT, Gpx, iNOS and AChE while showed little effect on the other evaluated biomarkers. Gpx was the most sensitive biomarker that sensitively indicated the organic pollution stress. (2) The simultaneous assay on heat shock protein 70 (Hsp70) expression was conducted by flow cytometry (FCM) and result presented that Hsp 70 expression could be effectively induced by SDBS as compared to the control throughout the experiment; however, B[a]P obviously induced Hsp70 during the first 12 d and then decreased to the level of the control. (3) The evaluated method of biomarker system combined with principal component analysis (PCA) could effectively distinguish different pollutants under controlled laboratory conditions and might be a promising and warning method for the early assessment of environmental change exposed to different organic pollutions.

[The Use of Extracorporeal Membrane Oxygenation in Sustaining Pulmonary Function Patients with Influenza A H1N1]

Zhongguo Wei Zhong Bing Ji Jiu Yi Xue = Chinese Critical Care Medicine = Zhongguo Weizhongbing Jijiuyixue. Mar, 2010  |  Pubmed ID: 20367907

To summarize the clinical method and initial experience of extracorporeal membrane oxygenation (ECMO) supportive treatment in influenza A H1N1 serious patients.

The Profile of Mitochondrial Proteins and Their Phosphorylation Signaling Network in INS-1 Beta Cells

Journal of Proteome Research. Jun, 2010  |  Pubmed ID: 20380455

Mitochondria have important roles in cellular physiological functions and various diseases. In pancreatic beta cells, mitochondria play a central role in glucose-stimulated insulin secretion (GSIS). To reveal the potential functions of mitochondria in the GSIS process in beta cells, shotgun proteomics was applied to profiling mitochondrial proteins and their potential phosphorylation sites in rat INS-1 cells. More than 800 proteins were assigned to mitochondria. In addition, 84 different mitochondrial phosphoproteins were identified, and 52 upstream kinases of mitochondrial phosphoproteins were predicted using bioinformatics tools. Regulation networks of mitochondrial phosphoproteins were constructed by integrating mitochondrial protein interaction networks and mitochondrial phosphorylation signaling, providing a preliminary survey of how phosphorylation signaling regulates mitochondrial function in beta cells. We present integrated resources including the protein composition and signaling pathways of mitochondria which can be used to understand the role of mitochondria in GSIS.

Start-up of the Canon Process from Activated Sludge Under Salt Stress in a Sequencing Batch Biofilm Reactor (SBBR)

Bioresource Technology. Aug, 2010  |  Pubmed ID: 20409706

In this study, a lab-scale sequencing batch biofilm reactor (SBBR) was used to start-up the completely autotrophic nitrogen removal over nitrite (Canon) process from conventional activated sludge under salt stress for 118days. A persistent, stable partial nitrification was achieved in the SBBR when the salt concentration gradually increased to 6.5 g NaCl L(-1). Anaerobic ammonium oxidation (Anammox) bacteria were successfully enriched from the conventional activated sludge in the SBBR after 68 days of operation. Anammox bacterial strains similar to the order Planctomycetales, genus Candidatus brocardia and genus Candidatus kuenenia were confirmed to exist in the internal layer of the biofilm via Fluorescence in Situ Hybridization (FISH) analysis. A maximal total nitrogen (TN) removal rate of 0.072 kg N m(-3) d(-1) was achieved for the Canon process when the salinity was maintained at a constant 10.0 g NaCl L(-1) in the SBBR. This reactor may have applications for the Canon process treatment of salinity wastewaters containing high concentrations of ammonia.

Chemoenzymatic Synthesis of the Sialyl Lewis X Glycan and Its Derivatives

Carbohydrate Research. Jun, 2010  |  Pubmed ID: 20435300

A combination of recombinant FKP and alpha-(1-->3)-fucosyltransferase allows the facile synthesis of the sialyl Lewis X tetrasaccharide glycan and its derivatives in excellent yield. In this system, the universal fucosyl donor, guanidine 5'-diphosphate-beta-L-fucose (GDP-fucose), or its analogues can be generated in situ by cofactor recycling using pyruvate kinase.

The Transmission Dynamics of Tuberculosis in a Recently Developed Chinese City

PloS One. 2010  |  Pubmed ID: 20454620

Hong Kong is an affluent subtropical city with a well-developed healthcare infrastructure but an intermediate TB burden. Declines in notification rates through the 1960s and 1970s have slowed since the 1980s to the current level of around 82 cases per 100 000 population. We studied the transmission dynamics of TB in Hong Kong to explore the factors underlying recent trends in incidence.

Brain Distribution and Toxicological Evaluation of a Systemically Delivered Engineered Nanoscale Ceria

Toxicological Sciences : an Official Journal of the Society of Toxicology. Aug, 2010  |  Pubmed ID: 20457660

Engineered nanoscale ceria is used as a diesel fuel catalyst. Little is known about its mammalian central nervous system effects. The objective of this paper is to characterize the biodistribution of a 5-nm citrate-stabilized ceria dispersion from blood into brain and its pro- or antioxidant effects. An approximately 4% aqueous ceria dispersion was iv infused into rats (0, 100, and up to 250 mg/kg), which were terminated after 1 or 20 h. Ceria concentration, localization, and chemical speciation in the brain were assessed by inductively coupled plasma mass spectrometry, light and electron microscopy (EM), and electron energy loss spectroscopy (EELS). Pro- or antioxidative stress effects were assessed as protein carbonyls, 3-nitrotyrosine, and protein-bound 4-hydroxy-2-trans-nonenal in hippocampus, cortex, and cerebellum. Glutathione reductase, glutathione peroxidase, manganese superoxide dismutase, and catalase levels and activities were measured in hippocampus. Catalase levels and activities were also measured in cortex and cerebellum. Na fluorescein and horseradish peroxidase (HRP) were given iv as blood-brain barrier (BBB) integrity markers. Mortality was seen after administration of 175-250 mg ceria/kg. Twenty hours after infusion of 100 mg ceria/kg, brain HRP was marginally elevated. EM and EELS revealed mixed Ce(III) and Ce(IV) valence in the freshly synthesized ceria in vitro and in ceria agglomerates in the brain vascular compartment. Ceria was not seen in microvascular endothelial or brain cells. Ceria elevated catalase levels at 1 h and increased catalase activity at 20 h in hippocampus and decreased catalase activity at 1 h in cerebellum. Compared with a previously studied approximately 30-nm ceria, this ceria was more toxic, was not seen in the brain, and produced little oxidative stress effect to the hippocampus and cerebellum. The results are contrary to the hypothesis that a smaller engineered nanomaterial would more readily permeate the BBB.

[Isolation and Characterization of a Humic-reducing Bacterium Shewanella Strain W3 from Mangrove Sediment]

Huan Jing Ke Xue= Huanjing Kexue / [bian Ji, Zhongguo Ke Xue Yuan Huan Jing Ke Xue Wei Yuan Hui "Huan Jing Ke Xue" Bian Ji Wei Yuan Hui.]. Apr, 2010  |  Pubmed ID: 20527189

A humus-reducing bacterium strain W3 was isolated from the mangrove sediment. Based on the analysis of morphology, physiobiochemical characteristics and 16S rDNA gene sequence, this strain was identified as Shewanella sp. W3. Strain W3 was able to reduce humic with lactate, formate and pyruvate as electron donor and the humic reduction rates to 1 mmol/L AQDS were 96%, 40% and 10% respectively within 48 hours. In addition, the bacteria can grow coupled with the humic reduction. Strain W3 grew to maximal density of 1.77 x 10(8) CFU/mL after complete reduction of 1 mmol/L AQDS. However, the growth of strain W3 was light increase in the control experiment in the absence of electron donor. The optimal initial pH, NaCl concentration, and temperature for strain W3 reducing humic were pH 7-9, 5-30 g/L, and 30-35 degrees C, respectively. Combined experimental results showed that the humic reduction was a biochemical process and strain W3 could conserve energy to support growth from lactate oxidation coupled to humic reduction. It is suggested that humic reduction by Shewanella bacteria may play important roles in biogeochemical circulation of elements and have potential application in the microbial bioremediation to contaminations.

Crystal Structures of TbCatB and Rhodesain, Potential Chemotherapeutic Targets and Major Cysteine Proteases of Trypanosoma Brucei

PLoS Neglected Tropical Diseases. 2010  |  Pubmed ID: 20544024

Trypanosoma brucei is the etiological agent of Human African Trypanosomiasis, an endemic parasitic disease of sub-Saharan Africa. TbCatB and rhodesain are the sole Clan CA papain-like cysteine proteases produced by the parasite during infection of the mammalian host and are implicated in the progression of disease. Of considerable interest is the exploration of these two enzymes as targets for cysteine protease inhibitors that are effective against T. brucei.

[Predictive Value of Fluorescence in Situ Hybridization in Patients with Bladder Cancer]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Jul, 2010  |  Pubmed ID: 20650776

To assess the value of fluorescence in situ hybridization (FISH) in the diagnosis of bladder cancer.

[Expression of P27kip1 in Renal Cell Carcinoma and Its Clinical Significance]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Aug, 2010  |  Pubmed ID: 20813693

To investigate the expression of cyclin-dependent kinase inhibitor p27kip1 in renal cell carcinoma and its clinical significance.

[The Advances of Antifibrosis Treatment]

Zhonghua Gan Zang Bing Za Zhi = Zhonghua Ganzangbing Zazhi = Chinese Journal of Hepatology. Aug, 2010  |  Pubmed ID: 20825709

[The Involvement of Posassium Channels in the Thick Ascending Limb of Renal Henle's Loop]

Sheng Li Ke Xue Jin Zhan [Progress in Physiology]. Dec, 2010  |  Pubmed ID: 21416964

Distributions of Typical Contaminant Species in Urban Short-term Storm Runoff and Their Fates During Rain Events: a Case of Xiamen City

Journal of Environmental Sciences (China). 2010  |  Pubmed ID: 20617729

The pollutants in urban storm runoff, which lead to an non-point source contamination of water environment around cities, are of great concerns. The distributions of typical contaminants and the variations of their species in short term storm runoff from different land surfaces in Xiamen City were investigated. The concentrations of various contaminants, including organic matter, nutrients (i.e., N and P) and heavy metals, were significantly higher in parking lot and road runoff than those in roof and lawn runoff. The early runoff samples from traffic road and parking lot contained much high total nitrogen (TN 6-19 mg/L) and total phosphorus (TP 1-3 mg/L). A large proportion (around 60%) of TN existed as total dissolved nitrogen (TDN) species in most runoff. The percentage of TDN and the percentage of total dissolved phosphorus remained relatively stable during the rain events and did not decrease as dramatically as TN and TP. In addition, only parking lot and road runoff were contaminated by heavy metals, and both Pb (25-120 microg/L) and Zn (0.1-1.2 mg/L) were major heavy metals contaminating both runoff. Soluble Pb and Zn were predominantly existed as labile complex species (50%-99%), which may be adsorbed onto the surfaces of suspended particles and could be easily released out when pH decreased. This would have the great impact to the environment.

Apollo Contributes to G Overhang Maintenance and Protects Leading-end Telomeres

Molecular Cell. Aug, 2010  |  Pubmed ID: 20619712

Mammalian telomeres contain a single-stranded 3' overhang that is thought to mediate telomere protection. Here we identify the TRF2-interacting factor Apollo as a nuclease that contributes to the generation/maintenance of this overhang. The function of mouse Apollo was determined using Cre-mediated gene deletion, complementation with Apollo mutants, and the TRF2-F120A mutant that cannot bind Apollo. Cells lacking Apollo activated the ATM kinase at their telomeres in S phase and showed leading-end telomere fusions. These telomere dysfunction phenotypes were accompanied by a reduction in the telomeric overhang signal. The telomeric functions of Apollo required its TRF2-interaction and nuclease motifs. Thus, TRF2 recruits the Apollo nuclease to process telomere ends synthesized by leading-strand DNA synthesis, thereby creating a terminal structure that avoids ATM activation and resists end-joining. These data establish that the telomeric overhang is required for the protection of telomeres from the DNA damage response.

Dual-target-directed 1,3-diphenylurea Derivatives: BACE 1 Inhibitor and Metal Chelator Against Alzheimer's Disease

Bioorganic & Medicinal Chemistry. Aug, 2010  |  Pubmed ID: 20620068

Dual-target-directed 1,3-diphenylurea derivatives were designed by hybridizing BACE 1 inhibitor 1 with metal chelator LR-90. A database consisted of 1,3-diphenylurea derivatives was built and screened by the pharmacophore model (Hypo 1) of BACE 1 inhibitor. Based on the predicted results, 11 compounds (6a-d, 9a-g) with favorable Fitvalues were selected, synthesized and evaluated for their BACE 1 inhibitory activities, which showed that the predicted results were in good agreement with the experimental values. Besides, the synthesized compounds also displayed the ability to chelate metal ions. The most effective BACE 1 inhibitor 9f (27.85+/-2.46 micromol/L) was selected for further receptor-binding studies, the result of which indicated that an essential hydrogen bonds was formed between the urea group of 9f and the catalytic aspartate Asp228.

Encapsulation of Dual Cytotoxic and Anti-angiogenic Gold(III) Complexes by Gelatin-acacia Microcapsules: in Vitro and in Vivo Studies

Dalton Transactions (Cambridge, England : 2003). Sep, 2010  |  Pubmed ID: 20652177

Encapsulation of the anticancer gold(III) complexes bearing porphyrin or Schiff-base ligands by gelatin-acacia microcapsules confers both sustained-release and rapid-release properties, improved solution stability and/or in vivo efficacy compared to that using the unencapsulated complexes alone.

A Selective G-quadruplex-based Luminescent Switch-on Probe for the Detection of Nanomolar Silver(I) Ions in Aqueous Solution

Chemical Communications (Cambridge, England). Dec, 2010  |  Pubmed ID: 20668746

A G-quadruplex-based luminescent platinum(II) switch-on probe has been developed for the selective detection of nanomolar Ag(+) ions in aqueous solution.

Ni2+-modulated Homocysteine-capped CdTe Quantum Dots As a Turn-on Photoluminescent Sensor for Detecting Histidine in Biological Fluids

Biosensors & Bioelectronics. Oct, 2010  |  Pubmed ID: 20708916

The high affinity of histidine to Ni2+ has long been recognized in metal ion affinity chromatography for the separation and purification of histidine-tagged proteins. Besides, such affinity pair has been explored in modern nanotechnology for constructing functional nanoparticle-histidine-tagged protein conjugates. However, the use of Ni2+-histidine affinity pair in conjunction with optically-active nanomaterials for sensor design, to our knowledge, has not been reported yet. Here we report a turn-on photoluminescent sensor for histidine based on Ni2+-modulated homocysteine (Hcy)-capped CdTe quantum dots (QDs) by taking the advantages of this well-known Ni2+-histidine affinity pair and photoluminescent QDs. The photoluminescence of Hcy-capped CdTe QDs can be effectively quenched by Ni2+ due to the binding of Ni2+ to the Hcy on the surface of the QDs and the electron transfer from the photoexcited QDs to Ni2+. The high affinity of histidine to Ni2+ enables Ni2+ to be dissociated from the surface of Hcy-capped CdTe QDs to form stable complex with histidine in solution, thereby recovering the photoluminescence of Hcy-capped CdTe QDs. The Ni2+ induced photoluminescence quenching and subsequent histidine-induced photoluminescence recovery for Hcy-capped CdTe QDs build a solid base for the present QD-based turn-on photoluminescent sensor for detecting histidine. The developed QD-based sensor gives excellent selectivity for histidine over other amino acids with the limit of detection (3 s) of 0.3 μM. The relative standard deviation for 11 replicate detections of 15 μM histidine was 2.7%. The developed sensor was applied to the determination of histidine in human urine samples with recoveries from 94.4% to 106%.

A Simple Chemical Etching Strategy to Generate "ion-imprinted" Sites on the Surface of Quantum Dots for Selective Fluorescence Turn-on Detecting of Metal Ions

Chemical Communications (Cambridge, England). Oct, 2010  |  Pubmed ID: 20730211

A simple general chemical etching strategy is developed to generate "ion-imprinted" sites on the surface of QDs for subsequent selective signal turn-on detection of metal ions.

Primary Isolated Hepatic Oval Cells Maintain Progenitor Cell Phenotypes After Two-year Prolonged Cultivation

Journal of Hepatology. Nov, 2010  |  Pubmed ID: 20739084

Although expandable hepatic progenitors provide renewable cell sources for treatment of hepatic disorders, long-term cultivation of hepatic progenitors may affect proliferation and differentiation abilities, and even initiate the formation of malignant cancer stem cells. This study aims to determine characteristics of primary cultured hepatic oval cells after prolonged cultivation in vitro.

Novel Immunodominant Peptide Presentation Strategy: a Featured HLA-A*2402-restricted Cytotoxic T-lymphocyte Epitope Stabilized by Intrachain Hydrogen Bonds from Severe Acute Respiratory Syndrome Coronavirus Nucleocapsid Protein

Journal of Virology. Nov, 2010  |  Pubmed ID: 20844028

Antigenic peptides recognized by virus-specific cytotoxic T lymphocytes (CTLs) are presented by major histocompatibility complex (MHC; or human leukocyte antigen [HLA] in humans) molecules, and the peptide selection and presentation strategy of the host has been studied to guide our understanding of cellular immunity and vaccine development. Here, a severe acute respiratory syndrome coronavirus (SARS-CoV) nucleocapsid (N) protein-derived CTL epitope, N1 (QFKDNVILL), restricted by HLA-A*2402 was identified by a series of in vitro studies, including a computer-assisted algorithm for prediction, stabilization of the peptide by co-refolding with HLA-A*2402 heavy chain and β(2)-microglobulin (β(2)m), and T2-A24 cell binding. Consequently, the antigenicity of the peptide was confirmed by enzyme-linked immunospot (ELISPOT), proliferation assays, and HLA-peptide complex tetramer staining using peripheral blood mononuclear cells (PBMCs) from donors who had recovered from SARS donors. Furthermore, the crystal structure of HLA-A*2402 complexed with peptide N1 was determined, and the featured peptide was characterized with two unexpected intrachain hydrogen bonds which augment the central residues to bulge out of the binding groove. This may contribute to the T-cell receptor (TCR) interaction, showing a host immunodominant peptide presentation strategy. Meanwhile, a rapid and efficient strategy is presented for the determination of naturally presented CTL epitopes in the context of given HLA alleles of interest from long immunogenic overlapping peptides.

Synergistic Killing Effect Between Vorinostat and Target of CD146 in Malignant Cells

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Nov, 2010  |  Pubmed ID: 20884621

Although histone deacetylase inhibitors (HDACi) are emerging as a new class of anticancer agents, one of the most significant concerns is that interactions with a wide array of substrates using these agents might initiate both therapeutic and undesired protective responses. Here, we sought to identify the potential protective reactions initiated by HDACi and determine whether targeting these reactions would enhance the antitumoral activity of HDACi.

Biocompatible Copper(I) Catalysts for in Vivo Imaging of Glycans

Journal of the American Chemical Society. Dec, 2010  |  Pubmed ID: 21062072

The Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) is the standard method for bioorthogonal conjugation. However, current Cu(I) catalyst formulations are toxic, hindering their use in living systems. Here we report that BTTES, a tris(triazolylmethyl)amine-based ligand for Cu(I), promotes the cycloaddition reaction rapidly in living systems without apparent toxicity. This catalyst allows, for the first time, noninvasive imaging of fucosylated glycans during zebrafish early embryogenesis. We microinjected embryos with alkyne-bearing GDP-fucose at the one-cell stage and detected the metabolically incorporated unnatural sugars using the biocompatible click chemistry. Labeled glycans could be imaged in the enveloping layer of zebrafish embryos between blastula and early larval stages. This new method paves the way for rapid, noninvasive imaging of biomolecules in living organisms.

Evaluation of Upper Urinary Tract Tumors by FISH in Chinese Patients

Cancer Genetics and Cytogenetics. Dec, 2010  |  Pubmed ID: 21156239

Upper urinary tract tumor (UUTT) usually presents a high grade and stage, and recurs frequently. The aim of this study was to evaluate the utility of a fluorescence in situ hybridization (FISH) assay on chromosomes 3, 7, 9, and 17 as a reliable and noninvasive method for the diagnosis of Chinese patients with UUTT. Urine specimens from 50 patients with UUTT and 25 donors without evidence of urothelial tumors were analyzed by cytology and FISH. Voided urine samples from 20 normal individuals were used to establish the cut-off values for FISH assay. The McNemar test was applied for sensitivity and specificity. The overall sensitivity of FISH was statistically significantly greater than that of cytology (84.0 vs. 40.0%, P = 0.000). The overall specificities of FISH and urine cytology were all 96.0% (P = 1.000). Polysomy in chromosomes 3, 7, and 17 were 38, 42, and 30%, respectively. Heterozygous and homozygous loss of the p16 locus was found in 36 and 32%, respectively. FISH analysis performed on cells collected from voided urine is feasible, and FISH could prove to be a reliable and less invasive ancillary test and improve the sensitivity of urine cytology in the diagnosis of UUTT.

[Synchronous Squamous Cell Carcinoma of the Renal Pelvis and Squamous Cell Carcinoma of the Ureter: Report of Two Cases and Review of Literature]

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. Dec, 2010  |  Pubmed ID: 21177201

To study the clinicopathological characteristics of synchronous squamous cell carcinoma (SCC) of the renal pelvis and SCC of the ureter.

[Repairing Effects of Low-intensity Pulsed Ultrasound on Alveolar Bone Defects in Beagle Dogs]

Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi Kouqiang Yixue Zazhi = West China Journal of Stomatology. Oct, 2010  |  Pubmed ID: 21179689

To evaluate the potential repairing effects of low-intensity pulsed ultrasound (LIPUS) irradiation on acute horizontal alveolar bone defects at the mandibular pre-molar areas in Beagle dogs.

Sodium Valproate at the Therapeutic Concentration Inhibits the Induction but Not the Maintenance Phase of Long-term Potentiation in Rat Hippocampal CA1 Area

Biochemical and Biophysical Research Communications. Jan, 2010  |  Pubmed ID: 19932082

Sodium valproate (VPA) is currently one of the major antiepileptic drugs and has been reported to impair the induction of long-term potentiation (LTP) in rat hippocampal. However, there are discrepancies when used at therapeutic dose and few researches to study the effects of VPA on the maintenance of LTP. Here we investigated the effects of VPA at therapeutic concentration on two LTP phases: induction and maintenance in CA1 region. We found (1) VPA inhibited field excitatory postsynaptic potentials (fEPSPs) without modifying paired-pulse facilitation (PPF) solely occurred presynaptically as a form of synaptic plasticity. (2) Pretreatment with VPA before high-frequency stimulation (HFS) decreased the fEPSPs slope. (3) There were no significant changes in fEPSPs slope with VPA applied in maintenance phase of LTP. These results indicate that VPA inhibited the induction of LTP postsynaptically without modifying presynaptic neurotransmitter release and had no significant influence on the two maintenance phase of LTP.

Phosphoproteome Analysis of Rat L6 Myotubes Using Reversed-phase C18 Prefractionation and Titanium Dioxide Enrichment

Journal of Proteome Research. Feb, 2010  |  Pubmed ID: 20028136

The rat L6 myotubes is an important in vitro model system for studying signaling pathways in skeletal muscle. Exploring phosphorylation events involved in the skeletal muscle is very significant for elucidating the kinase-substrate relationship, understanding regulatory mechanisms involved in signaling pathways and providing insights into numerous cell processes. Here, we used mass spectrometry-based proteomics to conduct global phosphoproteome profiling of rat L6 myotubes. Using an efficient phosphoproteomic strategy including prefractionation of tryptic peptide mixtures with self-packed RP C18 columns, phosphopeptide enrichment with TiO(2), and 2D-LC (SCX/RP)-MS/MS analysis, a total of 2230 unique phosphopeptides from 1195 proteins were identified with a false-discovery rate of less than 1.0% using a target/decoy database searching strategy. After determining the degree of certainty of the phosphorylation site location (Ascore value >or=19), 11 Ser motifs and one Thr motif were derived from our data set using the Motif-X algorithm. Several potential signaling pathways were found in our myotubes phosphoproteome, such as the MAPK signaling pathway and the IGF-1/Insulin signaling pathway.

Rapid and Selective Detection of Fatty Acylated Proteins Using Omega-alkynyl-fatty Acids and Click Chemistry

Journal of Lipid Research. Jun, 2010  |  Pubmed ID: 20028662

Progress in understanding the biology of protein fatty acylation has been impeded by the lack of rapid direct detection and identification methods. We first report that a synthetic omega-alkynyl-palmitate analog can be readily and specifically incorporated into GAPDH or mitochondrial 3-hydroxyl-3-methylglutaryl-CoA synthase in vitro and reacted with an azido-biotin probe or the fluorogenic probe 3-azido-7-hydroxycoumarin using click chemistry for rapid detection by Western blotting or flat bed fluorescence scanning. The acylated cysteine residues were confirmed by MS. Second, omega-alkynyl-palmitate is preferentially incorporated into transiently expressed H- or N-Ras proteins (but not nonpalmitoylated K-Ras), compared with omega-alkynyl-myristate or omega-alkynyl-stearate, via an alkali sensitive thioester bond. Third, omega-alkynyl-myristate is specifically incorporated into endogenous co- and posttranslationally myristoylated proteins. The competitive inhibitors 2-bromopalmitate and 2-hydroxymyristate prevented incorporation of omega-alkynyl-palmitate and omega-alkynyl-myristate into palmitoylated and myristoylated proteins, respectively. Labeling cells with omega-alkynyl-palmitate does not affect membrane association of N-Ras. Furthermore, the palmitoylation of endogenous proteins including H- and N-Ras could be easily detected using omega-alkynyl-palmitate as label in cultured HeLa, Jurkat, and COS-7 cells, and, promisingly, in mice. The omega-alkynyl-myristate and -palmitate analogs used with click chemistry and azido-probes will be invaluable to study protein acylation in vitro, in cells, and in vivo.

An Enzyme-linked Assay for the Rapid Quantification of MicroRNAs Based on the Viral Suppressor of RNA Silencing Protein P19

Analytical Biochemistry. May, 2011  |  Pubmed ID: 21284927

MicroRNAs (miRNAs) are endogenous posttranscriptional regulators found in all metazoa and play crucial roles in virtually all cellular processes. Their aberrant expression has been linked to several diseased states; therefore, techniques capable of sensitive and specific profiling of the miRNA milieu will have significant application in prognostics, diagnostics, and therapeutics. Here we present a method for rapid quantification of miRNA levels using p19, a tombusvirus-encoded suppressor of RNA interference with sequence-independent and size-selective affinity toward 19-bp RNA duplexes. We present a surface plasmon resonance (SPR)-based miRNA sensing method where RNA probes are immobilized on gold surfaces demonstrating p19's utility in recognition of miRNA-bound probes. This allows detection of miRNAs in the low nanomolar range. To increase the sensitivity, a bead-based enzyme immunoassay was performed, and this technique displays a lower detection limit of 1fmol and a linear dynamic range from 1pmol to 1fmol.

Synergistic Efficacy in Human Ovarian Cancer Cells by Histone Deacetylase Inhibitor TSA and Proteasome Inhibitor PS-341

Cancer Investigation. May, 2011  |  Pubmed ID: 21345073

Histone deacetylase inhibitors and proteasome inhibitor are all emerging as new classes of anticancer agents. We chose TSA and PS-341 to identify whether they have a synergistic efficacy on human ovarian cancer cells. After incubated with 500 nM TSA or/and 40 nM PS-341, we found that combined groups resulted in a striking increase of apoptosis and G2/M blocking rates, no matter in A2780, cisplatin-sensitive ovarian cancer cell line OV2008 or its resistant variant C13*. This demonstrated that TSA interacted synergistically with PS-341, which raised the possibility that combined the two drugs may represent a novel strategy in ovarian cancer.

Preparative Isolation of Alkaloids from Corydalis Bungeana Turcz. by High-speed Counter-current Chromatography Using Stepwise Elution

Journal of Separation Science. May, 2011  |  Pubmed ID: 21387560

High-speed counter-current chromatography (HSCCC) was successfully applied for the preparative separation and purification of alkaloids from Corydalis bungeana Turcz. (Kudiding in Chinese) for the first time. After the measurement of partition coefficient of seven target alkaloids in the nine two-phase solvent systems composed of CHCl(3)-MeOH-(0.1 M; 0.2 M; 0.3 M) HCl (4:1.5:2; 4:2:2; 4:3:2, v/v), CHCl(3)-MeOH-0.2 M HCl (4:2:2, v/v) and CHCl(3)-MeOH-0.3 M HCl (4:3:2, v/v) were finally selected for the HSCCC separation using the first upper phase as the stationary phase and the stepwise elution of the two lower mobile phases. Consequently, sanguinarine (10 mg), corynoline (25 mg), protopine (20 mg), corynoloxine (18 mg), and 12-hydroxycorynoline (8 mg) were obtained from 200 mg of crude alkaloid extracts with purities of 94-99% as determined by HPLC. Their chemical structures were characterized on the basis of (1)H-NMR, (13)C-NMR, and LC-ESI-Q-TOF-MS/MS analyses.

Metabolic Labeling of Fucosylated Glycans in Developing Zebrafish

ACS Chemical Biology. Jun, 2011  |  Pubmed ID: 21425872

Many developmental processes depend on proper fucosylation, but this post-translational modification is difficult to monitor in vivo. Here we applied a chemical reporter strategy to visualize fucosylated glycans in developing zebrafish. Using azide-derivatized analogues of fucose, we metabolically labeled cell-surface glycans and then detected the incorporated azides via copper-free click chemistry with a difluorinated cyclooctyne probe. We found that the fucose salvage pathway enzymes are expressed during zebrafish embryogenesis but that they process the azide-modified substrates inefficiently. We were able to bypass the salvage pathway by using an azide-functionalized analogue of GDP-fucose. This nucleotide sugar was readily accepted by fucosyltransferases and provided robust cell-surface labeling of fucosylated glycans, as determined by flow cytometry and confocal microscopy analysis. We used this technique to image fucosylated glycans in the enveloping layer of zebrafish embryos during the first 5 days of development. This work provides a method to study the biosynthesis of fucosylated glycans in vivo.

Tracking N-acetyllactosamine on Cell-surface Glycans in Vivo

Angewandte Chemie (International Ed. in English). Apr, 2011  |  Pubmed ID: 21472942

Response of Soybean Seed Germination to Cadmium and Acid Rain

Biological Trace Element Research. Dec, 2011  |  Pubmed ID: 21479540

Cadmium (Cd) pollution and acid rain are the main environmental issues, and they often occur in the same agricultural region. Nevertheless, up to now, little information on the combined pollution of Cd(2+) and acid rain action on crops were presented. Here, we investigated the combined effect of Cd(2+) and acid rain on the seed germination of soybean. The results indicated that the single treatment with the low level of Cd(2+) (0.18, 1.0, 3.0 mg L(-1)) or acid rain (pH ≥3.0) could not affect the seed germination of soybean, which was resulted in the increased activities of peroxidase and catalase. The single treatment with the high concentration of Cd(2+) (>6 mg L(-1)) or acid rain at pH 2.5 decreased the activities of peroxidase and catalase, damaged the cell membrane and then decreased the seed germination of soybean. Meanwhile, the same toxic effect was observed in the combined treatment with Cd(2+) and acid rain, and the combined treatment had more toxic effect than the single treatment with Cd(2+) or acid rain. Thus, the combined pollution of Cd(2+) and acid rain had more potential threat to the seed germination of soybean than the single pollution of Cd(2+) or acid rain.

Facile Fabrication of Magnetic Gold Electrode for Magnetic Beads-based Electrochemical Immunoassay: Application to the Diagnosis of Japanese Encephalitis Virus

Biosensors & Bioelectronics. Jun, 2011  |  Pubmed ID: 21570278

A novel magnetic beads-based electrochemical immunoassay strategy has been developed for the detection of Japanese encephalitis virus (JEV). The magnetic gold electrode was fabricated to manipulate magnetic beads for the direct sensing applications. Gold-coated magnetic beads were employed as the platforms for the immobilization and immunoreaction process, and horseradish peroxidase was chosen as an enzymatic tracer. The proteins (e.g., antibodies or immunocomplexes) attached on the surface of magnetic beads were found to induce a significant decline in their electric conductivity. Multiwalled carbon nanotubes were introduced to improve sensitivity of the assay. The envelope (E) protein, a major immunogenic protein of JEV, was utilized to optimize the assay parameters. Under the optimal conditions, the linear response range of E protein was 0.84 to 11,200 ng/mL with a detection limit of 0.56 ng/mL. When applied for detection of JEV, the proposed method generated a linear response range between 2×10(3) and 5×10(5) PFU/mL. The detection limit for JEV was 2.0×10(3) PFU/mL, which was 2 orders of magnitude lower than that of immunochromatographic strip and similar to that obtained from RT-PCR. This method was also successfully applied to detect JEV in clinical specimens.

Patient Outcome and Prognostic Factors of Renal Cell Carcinoma in Clinical Stage T(1-3)N(1-2)M(0): a Single-institution Analysis

Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University. May, 2011  |  Pubmed ID: 21602118

To report our data of patients with clinical stage T(1-3)N(1-2)M(0) renal cell carcinoma (RCC) and explore the biological behavior of this malignancy.

A Multidimensional Sensing Device for the Discrimination of Proteins Based on Manganese-Doped ZnS Quantum Dots

Angewandte Chemie (International Ed. in English). May, 2011  |  Pubmed ID: 21618375

Effects of Lard on the Formation of Volatiles from the Maillard Reaction of Cysteine with Xylose

Journal of the Science of Food and Agriculture. Sep, 2011  |  Pubmed ID: 21618545

The presence of lipid oxidation products in the Maillard reaction pathway is of particular interest today. The objective of this study was to investigate the effect of lard and its oxidation products on the formation of volatiles from cysteine and xylose model systems.

Metabolic Labeling of Fucosylated Glycoproteins in Bacteroidales Species

Bioorganic & Medicinal Chemistry Letters. Sep, 2011  |  Pubmed ID: 21676614

Members of the Bacteroidales order are among the most abundant gram-negative bacteria of the human colonic microbiota. These species decorate their cell-surface glycoproteins with fucosylated glycans, which are believed to play important roles in host intestinal colonization. Currently, there is no method for the enrichment of these glycoproteins for their identification. Here, we describe a chemical approach directed toward labeling and detecting fucosylated glycoproteins from cultured Bacteroidales species, namely Bacteroides fragilis and Parabacteroides distasonis. We treated these bacteria with an alkyne-bearing fucose analog, which is metabolically integrated into the bacterial surface fucosylated glycoproteins. The alkyne-tagged glycoproteins can then react with azide-bearing biophysical probes via bioorthogonal click chemistry for detection or glycoproteomic analysis.

Increasing the Efficacy of Bioorthogonal Click Reactions for Bioconjugation: A Comparative Study

Angewandte Chemie (International Ed. in English). Jul, 2011  |  Pubmed ID: 21761519

Metal Accumulation in the Tissues of Grass Carps (Ctenopharyngodon Idellus) from Fresh Water Around a Copper Mine in Southeast China

Environmental Monitoring and Assessment. Jul, 2011  |  Pubmed ID: 21800063

Mining effluents are the main source of metals in the surrounding aquatic environment. The mining district of Purple Mountain has a history of copper mining for more than 30 years, but there is limited investigation of metal bioaccumulation in the aquatic creatures from the Tingjiang river catchment affected by the mining activities. In this study, we collected grass carps (Ctenopharyngodon idellus) from four sites, and analyzed the accumulation of chromium (Cr), nickel (Ni), manganese (Mn), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) in ten tissues (scale, skin, muscle, gill, liver, kidney, fish maw, heart, stomach, and intestine) of the fish samples. Among all tissue samples, the highest concentrations (micrograms per gram wet weight) of Ni (0.263), Cu (69.2), Zn (84.0), As (0.259), Cd (0.640), Hg (0.051), and Pb (0.534) were noted in the liver, gill, and kidney tissues, whereas the highest concentrations of Cr (0.356) and Mn (62.7) were detected in the skin and intestine, respectively. These results gave a better understanding of the variability of metals distribution in different fish tissues. In comparison with the sample sites, metals (especially Mn, Cu, Zn, Ni, and Pb) in liver, gill, kidney, stomach, and intestine showed more inter-site differences than other tissues. The inter-site differences also revealed that site 1 and 2 increased fish uptake of Cu, Zn, Ni, and Pb, which may indicate that the copper mine and urban effluents contributed to high levels of these metals in aquatic environments in site 1 and 2. A potential food safety issue may emerge depending on the mining activities in this region because some metals in a few tissue samples exceeded the guideline values for human consumption of fish.

Chemically Immobilized T4-bacteriophage for Specific Escherichia Coli Detection Using Surface Plasmon Resonance

The Analyst. Feb, 2011  |  Pubmed ID: 21079850

A bioassay platform using T4 bacteriophage (T4) as the specific receptor and surface plasmon resonance (SPR) as the transduction technique has been developed for the detection of Escherichia coli K12 bacteria. The T4 phages have been covalently immobilized onto gold surfaces using a self-assembled monolayer of dithiobis(succinimidyl propionate) (DTSP). Substrates of BSA/EA-T4/DTSP/Au prepared using different T4 phage concentrations have been characterized using scanning electron microscopy (SEM). The studies reveal that the use of DTSP results in a uniform binding of T4 phages onto the surface. The SPR analysis demonstrates that these BSA/EA-T4/DTSP/Au interfaces can detect the E. coli K12 with high specificity against non-host E. coli NP10 and NP30. Results of SEM and SPR studies indicate that the maximum host bacterial capture is obtained when 1.5 × 10(11) pfu ml(-1) concentration of T4 phages was used for immobilization. The surface of these chemically anchored phage substrates can be regenerated for repeated detection of E. coli K12 and can be used for detection in 7 × 10(2) to 7 × 10(8) cfu ml(-1) range. The results of these studies have implications for the development of online bioassays for the detection of various food and water borne pathogens using the inherent selectivity of bacteriophage recognition.

Brettanomyces As a Starter Culture in Rice-steamed Sponge Cake: a Traditional Fermented Food in China

Current Microbiology. Nov, 2011  |  Pubmed ID: 21882006

The potential use of Brettanomyces anomalus PSY-001 as an additional starter culture for the production of Rice-steamed sponge cake (RSSC), a traditional fermented food in China, was investigated. Two productions of RSSC, each containing batches of experimental cakes with Brettanomyces added and reference cakes with the leavened liquid added were carried out. For both experimental and reference cakes, chemical analysis and sensory evaluation were carried out during the fermentation period. The results showed that experimental cakes had desirable aroma and taste. The observed differences indicate a positive contribution to the overall quality of RSSC by B. anomalus PSY-001.

Sulfated Ligands for the Copper(I)-catalyzed Azide-alkyne Cycloaddition

Chemistry, an Asian Journal. Oct, 2011  |  Pubmed ID: 21905231

The copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), the prototypical reaction of click chemistry, is accelerated by tris(triazolylmethyl)amine-based ligands. Herein, we compare two new ligands in this family--3-[4-({bis[(1-tert-butyl-1H-1,2,3-triazol-4-yl)methyl]amino}methyl)-1H-1,2,3-triazol-1-yl]propanol (BTTP) and the corresponding sulfated ligand 3-[4-({bis[(1-tert-butyl-1H-1,2,3-triazol-4-yl)methyl]amino}methyl)-1H-1,2,3-triazol-1-yl]propyl hydrogen sulfate (BTTPS)--for three bioconjugation applications: 1) labeling of alkyne-tagged glycoproteins in crude cell lysates, 2) labeling of alkyne- or azide-tagged glycoproteins on the surface of live mammalian cells, and 3) labeling of azides in surface proteins of live Escherichia coli. Although BTTPS exhibits faster kinetics than BTTP in accelerating the CuAAC reaction in in vitro kinetic measurements, its labeling efficiency is slightly lower than BTTP in modifying biomolecules with a significant amount of negative charges due to electrostatic repulsion. Nevertheless, the negative charge conferred by the sulfate at physiological conditions significantly reduced the cellular internalization of the coordinated copper(I), thus making BTTPS-Cu(I) a better choice for live-cell labeling.

[Association Between the Change Regularity of Peripheral Blood Mononuclear Cell Mitochondrial Deoxyribonucleic Acid Content and Human Immunodeficiency Virus-related Lipodystrophy]

Zhonghua Yi Xue Za Zhi. Jun, 2011  |  Pubmed ID: 21914278

To investigate the change regularity of peripheral blood mononuclear cell (PBMC) mtDNA (mitochondrial deoxyribonucleic acid) content and its association with HIV-LD (human immunodeficiency virus-related lipodystrophy) in HAART (highly active antiretroviral therapy).

Humic Analog AQDS and AQS As an Electron Mediator Can Enhance Chromate Reduction by Bacillus Sp. Strain 3C(3)

Applied Microbiology and Biotechnology. Sep, 2011  |  Pubmed ID: 21938640

Humus as an electron mediator is recognized as an effective strategy to improve the biological transformation and degradation of toxic substances, yet the action of humus in microbial detoxification of chromate is still unknown. In this study, a humus-reducing strain 3C(3) was isolated from mangrove sediment. Based on the analyses of morphology, physiobiochemical characteristics, and 16S rRNA gene sequence, this strain was identified Bacillus sp. Strain 3C(3) can effectively reduce humic analog anthraquinone-2,6-disulfonate (AQDS) and anthraquinone-2-sulfonate (AQS) with lactate, formate, or glucose as electron donors. When the cells were killed by incubation at 95°C for 30 min or an electron donor was absent, the humic reduction did not occur, showing that the humic reduction was a biochemical process. However, strain 3C(3) had low capability of chromate reduction under anaerobic conditions, despite of having strong tolerance of the toxic metal. But in the presence of humic substances AQDS or AQS, we found that chromate reduction by strain 3C(3) was enhanced greatly. Because strain 3C(3) is an effective humus-reducing bacterium, it is proposed that humic substances could serve as electron mediator to interact with chromate and accelerate chromate reduction. Our results suggest that chromate contaminations can be detoxified by adding humic analog (low to 0.1 mM) as an electron mediator in the microbial incubation.

The Age-specific Cumulative Incidence of Infection with Pandemic Influenza H1N1 2009 Was Similar in Various Countries Prior to Vaccination

PloS One. 2011  |  Pubmed ID: 21850217

During the influenza pandemic of 2009 estimates of symptomatic and asymptomatic infection were needed to guide vaccination policies and inform other control measures. Serological studies are the most reliable way to measure influenza infection independent of symptoms. We reviewed all published serological studies that estimated the cumulative incidence of infection with pandemic influenza H1N1 2009 prior to the initiation of population-based vaccination against the pandemic strain.

An Analysis of National Target Groups for Monovalent 2009 Pandemic Influenza Vaccine and Trivalent Seasonal Influenza Vaccines in 2009-10 and 2010-11

BMC Infectious Diseases. 2011  |  Pubmed ID: 21871096

Vaccination is generally considered to be the best primary prevention measure against influenza virus infection. Many countries encourage specific target groups of people to undertake vaccination, often with financial subsidies or a priority list. To understand differential patterns of national target groups for influenza vaccination before, during and after the 2009 influenza pandemic, we reviewed and analyzed the country-specific policies in the corresponding time periods.

Synthesis and Biological Evaluation of Novel 2-arylamino-3-(arylsulfonyl)quinoxalines As PI3Kα Inhibitors

European Journal of Medicinal Chemistry. Nov, 2011  |  Pubmed ID: 21945250

A series of novel 2-arylamino-3-(arylsulfonyl)quinoxalines was synthesized through a newly developed approach. All synthesized target compounds were screened for their cytotoxicities against cancer cell lines including PC3, A549, HCT116, HL60 and KB. Representative compounds with favorable cytotoxicities were tested for their PI3Kα inhibitory activities. Among the synthesized target compounds, 17 (PI3Kα IC(50): 0.07 μM) displayed the most potent cellular activities (IC(50) values of 0.14 μM, 0.07 μM, 0.95 μM and 0.05 μM against PC3, A549, HCT116 and HL 60, respectively).

Flavonoids As Vasorelaxant Agents: Synthesis, Biological Evaluation and Quantitative Structure Activities Relationship (QSAR) Studies

Molecules (Basel, Switzerland). 2011  |  Pubmed ID: 21959298

A series of 2-(2-diethylamino)-ethoxychalcone and 6-prenyl(or its isomers)-flavanones 10a,b and 11a-g were synthesized and evaluated for their vasorelaxant activities against rat aorta rings pretreated with 1 μM phenylephrine (PE). Several compounds showed potent vasorelaxant activities. Compound 10a (EC(50) = 7.6 μM, E(max) = 93.1%), the most potent one, would be a promising structural template for development of novel and more efficient vasodilators. Further, 2D-QSAR analysis of compounds 10a,b and 11c-e as well as thirty previously synthesized flavonoids 1-3 and 12-38 using Enhanced Replacement Method-Multiple Linear Regression (ERM-MLR) was further performed based on an optimal set of molecular descriptors (H5m, SIC2, DISPe, Mor03u and L3m), leading to a reliable model with good predictive ability (R(train)(2) = 0.839, Q(loo)(2) = 0.733 and R(test)(2) = 0.804). The results provide good insights into the structure- activity relationships of the target compounds.

Association of Genetic Variations in MTOR with Risk of Childhood Acute Lymphoblastic Leukemia in a Chinese Population

Leukemia & Lymphoma. Dec, 2011  |  Pubmed ID: 21973240

The mammalian target of rapamycin (mTOR) is an important protein kinase regulating cell survival and apoptosis. To determine whether genetic variations in mTOR are associated with risk of acute lymphoblastic leukemia (ALL) in Chinese children, we genotyped two tag single nucleotide poymorphisms (SNPs) in mTOR (rs2536 and rs2295080) in a case-control study. We observed that the variant genotype TC of mTOR rs2536 was associated with a significantly decreased risk of childhood ALL (adjusted odds ratio [OR] = 0.67, 95% confidence interval [CI] = 0.46-0.96), and the association was more pronounced in high-risk ALL and T-phenotype ALL groups. Additionally, we found that the combined genotypes TC/CC decreased the risk of ALL only in the high-risk ALL group (adjusted OR = 0.54, 95% CI = 0.32-0.91) and T-phenotype ALL group (adjusted OR = 0.29, 95% CI = 0.10-0.84). These results suggest that the mTOR rs2536 polymorphism is involved in the susceptibility to childhood ALL in a Chinese population.

Complex Capacitance Scaling in Ionic Liquids-filled Nanopores

ACS Nano. Nov, 2011  |  Pubmed ID: 22017626

Recent experiments have shown that the capacitance of subnanometer pores increases anomalously as the pore width decreases, thereby opening a new avenue for developing supercapacitors with enhanced energy density. However, this behavior is still subject to some controversy since its physical origins are not well understood. Using atomistic simulations, we show that the capacitance of slit-shaped nanopores in contact with room-temperature ionic liquids exhibits a U-shaped scaling behavior in pores with widths from 0.75 to 1.26 nm. The left branch of the capacitance scaling curve directly corresponds to the anomalous capacitance increase and thus reproduces the experimental observations. The right branch of the curve indirectly agrees with experimental findings that so far have received little attention. The overall U-shaped scaling behavior provides insights on the origins of the difficulty in experimentally observing the pore-width-dependent capacitance. We establish a theoretical framework for understanding the capacitance of electrical double layers in nanopores and provide mechanistic details into the origins of the observed scaling behavior. The framework highlights the critical role of "ion solvation" in controlling pore capacitance and the importance of choosing anion/cation couples carefully for optimal energy storage in a given pore system.

Searching for the Multi-Target-Directed Ligands Against Alzheimer's Disease: Discovery of Quinoxaline-based Hybrid Compounds with AChE, H₃R and BACE 1 Inhibitory Activities

Bioorganic & Medicinal Chemistry. Dec, 2011  |  Pubmed ID: 22019465

A novel series of quinoxaline derivatives, as Multi-Target-Directed Ligands (MTDLs) for AD treatment, were designed by lending the core structural elements required for H(3)R antagonists and hybridizing BACE 1 inhibitor 1 with AChE inhibitor BYYT-25. A virtual database consisting of quinoxaline derivatives was first screened on a pharmacophore model of BACE 1 inhibitors, and then filtered by a molecular docking model of AChE. Seventeen quinoxaline derivatives with high score values were picked out, synthesized and evaluated for their biological activities. Compound 11a, the most effective MTDL, showed the potent activity to H(3)R/AChE/BACE 1 (H(3)R antagonism, IC(50)=280.0 ± 98.0 nM; H(3)R inverse agonism, IC(50)=189.3 ± 95.7 nM; AChE, IC(50)=483 ± 5 nM; BACE 1, 46.64±2.55% inhibitory rate at 20 μM) and high selectivity over H(1)R/H(2)R/H(4)R. Furthermore, the protein binding patterns between 11a and AChE/BACE 1 showed that it makes several essential interactions with the enzymes.

Mesenchymal Stem Cells As Carriers and Amplifiers in CRAd Delivery to Tumors

Molecular Cancer. 2011  |  Pubmed ID: 22054049

Mesenchymal stem cells (MSCs) have been considered to be the attractive vehicles for delivering therapeutic agents toward various tumor diseases. This study was to explore the distribution pattern, kinetic delivery of adenovirus, and therapeutic efficacy of the MSC loading of E1A mutant conditionally replicative adenovirus Adv-Stat3(-) which selectively replicated and expressed high levels of anti-sense Stat3 complementary DNA in breast cancer and melanoma cells.

[TMEM16/ANOCTAMIN: the Newest Chloride Channel Family]

Sheng Li Ke Xue Jin Zhan [Progress in Physiology]. Aug, 2011  |  Pubmed ID: 22066423

[A Severe Case of Avian-like H1N1 Swine Influenza Virus Infection in Human]

Zhonghua Er Ke Za Zhi. Chinese Journal of Pediatrics. Aug, 2011  |  Pubmed ID: 22093434

Identification of the Major Functional Proteins of Prokaryotic Lipid Droplets

Journal of Lipid Research. Dec, 2011  |  Pubmed ID: 22180631

Storage of cellular triacylglycerols (TAG) in lipid droplets (LDs) has been linked to the progression of many metabolic diseases in humans, and to the development of biofuels from plants and microorganisms. However, the biogenesis and dynamics of LDs are poorly understood. Compared with other organisms bacteria seem to be a better model system for studying LD biology since they are relatively simple and are highly efficient in converting biomass to TAG. We obtained highly purified LDs from Rhodococcus sp. RHA1, a bacterium that can produce TAG from many carbon sources, and then comprehensively characterized the LD proteome. Of the 228 LD-associated proteins identified, two major proteins, ro02104 and PspA, constituted about 15% of the total LD protein. The structure predicted for ro02104 resembles that of apolipoproteins, the structural proteins of plasma lipoproteins in mammals. Deletion of ro02104 resulted in the formation of supersized LDs, indicating that ro02104 plays a critical role in cellular LD dynamics. The putative alpha helix of the ro02104 LD-targeting domain (amino acids 83-146) is also similar to that of apolipoproteins. We report the identification of 228 proteins in the proteome of prokaryotic LDs, identify a putative structural protein of this organelle and suggest that apolipoproteins may have an evolutionarily conserved role in the storage and trafficking of neutral lipids.

Supine Versus Prone Position in Percutaneous Nephrolithotomy for Kidney Calculi: a Meta-analysis

International Urology and Nephrology. Mar, 2011  |  Pubmed ID: 20628815

Supine position and prone position were the choice for percutaneous nephrolithotomy (PCNL). However, there is still no consensus on the optimal position for PCNL.

Ceria-engineered Nanomaterial Distribution In, and Clearance From, Blood: Size Matters

Nanomedicine (London, England). Jan, 2012  |  Pubmed ID: 22191779

Characterize different sized ceria-engineered nanomaterial (ENM) distribution in, and clearance from, blood (compared to the cerium ion) following intravenous infusion.

Biosorptive Dehydration of Tert-butyl Alcohol Using a Starch-based Adsorbent: Characterization and Thermodynamics

Bioresource Technology. Mar, 2012  |  Pubmed ID: 22209439

Biosorptive dehydration of tert-butyl alcohol (TBA) using a specially formulated compound starch-based adsorbent was investigated. The net retention time and separation factor of TBA and water were obtained using inverse gas chromatography (IGC), which demonstrated the feasibility of this biosorptive separation process, with low temperature propitious to the process. Through orthogonal experimental design, the optimum adsorption condition was determined from different bed depths, bed temperatures and kettle temperatures. Thermal regeneration experiments showed no change in biosorption capacity after five biosorption/regeneration cycles. Field emission scanning electron microscopy (FESEM) and mercury porosimetry were used to investigate the change in surface morphology and microstructure of the biosorbent before and after adsorption. Finally, the thermodynamic parameters ΔH(s) and ΔG(s) were determined, which indicated that the process occurred by physisorption and was spontaneous and exothermic. The results indicated that the biosorbent can be used as an effective low-cost sorbent to dehydrate TBA.

The "HER2-PI3K/Akt-FASN Axis" Regulated Malignant Phenotype of Colorectal Cancer Cells

Lipids. Jan, 2012  |  Pubmed ID: 22218925

Recent evidence suggests that HER2 (ErbB2; Her-2/neu) and the related PI3K/Akt signaling pathway substantially affect the malignant phenotype of colorectal cancer cells. Moreover, fatty acid synthase (FASN), which mediates de-novo fatty acid synthesis, is crucially important in the carcinogenesis process of a variety of cancers, including colorectal cancer. The purpose of this study was to investigate the malignant phenotype regulation of colorectal cancer cells via the "HER2-PI3K/Akt-FASN axis". Caco-2 cells with high expression of HER2 and FASN and high transfection efficiency were selected for functional characterization. The cells were transfected with either HER2-specific RNAi plasmid or negative control RNAi plasmid, followed by Q-RT-PCR and western blot assays to examine expression of HER2, PI3K, Akt, and FASN. MTT and colony-formation assays were used to assess proliferation. Migration was investigated by use of the transwell assay, and apoptosis and cell cycle were assayed by use of flow cytometry. Expression of HER2, PI3K, Akt, and FASN were downregulated when HER2 was silenced. Proliferation decreased after downregulation of HER2, which was consistent with increased apoptosis. Migration of HER2-silenced cells was also impaired. Loss of HER2 inhibits the activity of the "HER2-PI3K/Akt-FASN axis" of Caco-2 cells, and reduced activity of this axis alters the malignant behavior of Caco-2 cells.

Development and Application of an Antigen Capture ELISA Assay for Diagnosis of Japanese Encephalitis Virus in Swine, Human and Mosquito

Virology Journal. 2012  |  Pubmed ID: 22221768

ABSTRACT:

QSAR Models for Isoindolinone-based P53-MDM2 Interaction Inhibitors Using Linear and Non-linear Statistical Methods

Chemical Biology & Drug Design. Jan, 2012  |  Pubmed ID: 22233482

The design and optimization of p53-MDM2 interaction inhibitors has attracted a great deal of interest in the development of new anticancer agents. Systematical 2D-QSAR studies on 98 isoindolinone-based p53-MDM2 interaction inhibitors were carried out using linear and the non-linear mathematical methods. At first, a forward stepwise-multiple linear regression model (FS-MLR) was proposed with reasonable statistical parameters (R(train) (2)  = 0.881, Q(loo) (2)  = 0.847, R(test) (2)  = 0.854). Then, enhanced replacement method-multiple linear regression (ERM-MLR) and support vector machine regression (SVMR) were applied to set up more accurate models (ERM-MLR: R(train) (2)  = 0.914, Q(loo) (2)  = 0.894 and R(test) (2)  = 0.903; SVMR: R(train) (2)  = 0.924, Q(loo) (2)  = 0.920 and R(test) (2) of 0.874). Furthermore, the reliability and application value of the ERM and SVMR model was also validated in virtual screening through receiver operating characteristic studies.

Supercritical Fluid Extraction Assisted Isolation of Sesquiterpene Lactones with Antiproliferative Effects from Centipeda Minima

Phytochemistry. Jan, 2012  |  Pubmed ID: 22277736

Pseudoguaianolide sesquiterpene lactones minimolides A (1), B (2), C (3) and D (4) and two guaianolide sesquiterpene lactones minimolides E (5) and F (6), along with seven known ones (7-13), were isolated from the supercritical fluid extract of Centipeda minima. The structures of these compounds were elucidated by extensive spectroscopic methods (IR, UV, HRESIMS, 1D-NMR and 2D-NMR), and the complete structure and stereochemistry of 1 was further confirmed by X-ray diffraction analysis. Compounds 1, 5-8,11 and 13 displayed inhibitory activity against human nasopharyngeal cancer cells (CNE) with IC(50) values ranging from 1.1 to 20.3μM. Compound 13 containing both α-methylene-γ-lactone and α, β-unsaturated cyclopentenone moieties exhibited even stronger inhibitory activity than that of cisplatin (positive control) through cell cycle arrest at G2/M phase. Isolation of six sesquiterpene lactones from Centipeda minima highlighted the potential of supercritical fluid extraction for enrichment of minor constituents for phytochemical study.

Breast Cancer Associated Fibroblasts Promote MCF-7 Invasion in Vitro by Secretion of HGF

Journal of Huazhong University of Science and Technology. Medical Sciences = Hua Zhong Ke Ji Da Xue Xue Bao. Yi Xue Ying De Wen Ban = Huazhong Keji Daxue Xuebao. Yixue Yingdewen Ban. Feb, 2012  |  Pubmed ID: 22282252

This study was aimed to explore the influence of breast cancer associated fibroblasts (CAFs) in migration and invasion of breast cancer cell line MCF-7, and investigate whether hepatocyte growth factor (HGF) is involved in this process. Primary breast CAFs and their corresponding normal breast fibroblasts (NFs) were obtained by collagenase digestion. On the basis of the co-culture, the migration and invasion capacity of MCF-7 cells was compared between CAFs and NFs by Transwell. The difference in the HGF expression between them was detected by ELISA. The secretion of HGF was knocked down by using RNA interference technology in CAFs. Then the changes of migration and invasion capacity of MCF-7 cells were investigated by Transwell. Eventually, we isolated high-purity CAFs and NFs, and the CAFs had a stronger ability in promoting MCF-7 migration and invasion than the NFs. ELISA results demonstrated that CAFs secreted higher HGF, and the capacity of MCF-7 migration and invasion was declined after knocking down the secretion of HGF in CAFs by RNA interference. It is suggested that CAFs can promote MCF-7 migration and invasion through HGF in vitro.

Imaging the Glycome in Living Systems

Methods in Enzymology. 2012  |  Pubmed ID: 22289465

The glycome, the full complement of glycans that cells produce, is an attractive target for molecular imaging. Imaging of the glycome in living systems has recently been enabled via bioorthogonal chemical reporter-based approaches. In this chapter, we describe two approaches to introduce bioorthogonal chemical reporters (tags) onto cell surface fucosylated glycans and glycans bearing LacNAc disaccharides, respectively. The tagged glycans can then be conjugated to imaging probes via bioorthogonal click chemistry. Similar approaches can be extended to image other sectors of the glycome in living systems.

A Potent Oncolytic Adenovirus Selectively Blocks the STAT3 Signaling Pathway and Potentiates Cisplatin Antitumor Activity in Ovarian Cancer

Human Gene Therapy. Jan, 2012  |  Pubmed ID: 21875334

Abstract Cisplatin-centered chemotherapy is the first-line treatment for human ovarian cancer. However, chemoresistance remains a major obstacle to successful treatment. Evidence has indicated that signal transducer and activator of transcription-3 (STAT3) is a determinant of chemoresistance; it was related to tumor recurrence in a large number of solid malignancies. Unfortunately, none of the compounds currently developed to block STAT3 signaling has been considered a serious clinical candidate because of toxicity or limited bioavailability. In this study, we clarified the significance of STAT3 activation in chemoresistant ovarian cancer and assessed the suitability of a novel oncolytic adenovirus (M4) designed to specifically deplete STAT3 and reverse cisplatin resistance in ovarian cancer. We showed that aberrant expression and constitutive activation of STAT3 was instrumental in cisplatin resistance in ovarian cancer cell lines and in ovarian cancer tissue samples. The M4 adenovirus could specifically deplete constitutive and inducible STAT3 and phosphorylated STAT3 proteins in ovarian cancer cells. This significantly inhibited cell survival and enhanced cisplatin-induced apoptosis. In contrast, normal human umbilical vein endothelial cells and human ovarian surface epithelial cells appeared to be unaffected by M4 treatment. Furthermore, a combined cisplatin plus M4 therapy substantially eliminated populations enriched in tumor-initiating cells. In mice, systemic intraperitoneal administration of M4 significantly potentiated the antitumor effect of cisplatin. These results suggest that M4 has great potential as a therapy against cisplatin resistance in human ovarian cancer. Thus, it warrants further clinical investigation.